sys: Remove ancient SCCS tags.

Remove ancient SCCS tags from the tree, automated scripting, with two
minor fixup to keep things compiling. All the common forms in the tree
were removed with a perl script.

Sponsored by: Netflix

sys: Remove $FreeBSD$: one-line .c pattern

Remove /^[\s*]*__FBSDID\("\$FreeBSD\$"\);?\s*\n/

inpcb: do not copy so_options into inp_flags2

Since f71cb9f74808 socket stays connnected with inpcb through latter's
lifetime and there is no reason to complicate things and copy these
flags.

Reviewed by: markj
Differential Revision: https://reviews.freebsd.org/D41198

ip output: ensure that mbufs are mapped if ipsec is enabled

Ipsec needs access to packet headers to determine if a policy is
applicable. It seems that typically IP headers are mapped, but the code
is arguably needs to check this before blindly accessing them. Then,
operations like m_unshare() and m_makespace() are not yet ready for
unmapped mbufs.

Ensure that the packet is mapped before calling into IPSEC_OUTPUT().

PR: 272616
Reviewed by: jhb, markj
Sponsored by: NVidia networking
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D41112

netinet: re-read IP length after PFIL hook

The pfil hook may modify the packet, so before we check its length (to
decide if it needs to be fragmented or not) we should re-read that
length.

This is most likely to happen when pf is reassembling packets. In that
scenario we'd receive the last fragment, which is likely to be a short
packet, pf would reassemble it (likely exceeding the interface MTU) and
then we'd transmit it without fragmenting, because we're comparing the
MTU to the length of the last fragment, not the fully reassembled
packet.

See also: https://redmine.pfsense.org/issues/14396
Reviewed by: cy
MFC after: 3 weeks
Sponsored by: Rubicon Communications, LLC ("Netgate")
Differential Revision: https://reviews.freebsd.org/D40395

netinet: Remove the IP(V6)_RSS_LISTEN_BUCKET socket option

It has no effect, and an exp-run revealed that it is not in use.

PR: 261398 (exp-run)
Reviewed by: mjg, glebius
Sponsored by: Klara, Inc.
Differential Revision: https://reviews.freebsd.org/D38822

netinet: Remove IP(V6)_BINDMULTI

This option was added in commit 0a100a6f1ee5 but was never completed.
In particular, there is no logic to map flowids to different listening
sockets, so it accomplishes basically the same thing as SO_REUSEPORT.
Meanwhile, we've since added SO_REUSEPORT_LB, which at least tries to
balance among listening sockets using a hash of the 4-tuple and some
optional NUMA policy.

The option was never documented or completed, and an exp-run revealed
nothing using it in the ports tree. Moreover, it complicates the
already very complicated in_pcbbind_setup(), and the checking in
in_pcbbind_check_bindmulti() is insufficient. So, let's remove it.

PR: 261398 (exp-run)
Reviewed by: glebius
Sponsored by: Klara, Inc.
Differential Revision: https://reviews.freebsd.org/D38574

net: use pfil_mbuf_{in,out} where we always have an mbuf

This finalizes what has been started in 0b70e3e78b0.

Reviewed by: kp, mjg
Differential revision: https://reviews.freebsd.org/D37976

IfAPI: Explicitly include <net/if_private.h> in netstack

Summary:
In preparation of making if_t completely opaque outside of the netstack,
explicitly include the header. <net/if_var.h> will stop including the
header in the future.

Sponsored by: Juniper Networks, Inc.
Reviewed by: glebius, melifaro
Differential Revision: https://reviews.freebsd.org/D38200

ip_output: always increase "cantfrag" stat if ip_fragment() fails

While here, join two unlikely cases into one if clause.

Submitted by: Ivan Rozhuk <rozhuk.im gmail.com>
PR: 265718
Reviewed by: mjg, melifaro
Differential revision: https://reviews.freebsd.org/D36584

net: retire PFIL_FWD

It is now unused and not having it allows further clean ups.

Reviewed by: cy, glebius, kp
Sponsored by: Rubicon Communications, LLC ("Netgate")
Differential Revision: https://reviews.freebsd.org/D36452

protosw: refactor protosw and domain static declaration and load

o Assert that every protosw has pr_attach. Now this structure is
only for socket protocols declarations and nothing else.
o Merge struct pr_usrreqs into struct protosw. This was suggested
in 1996 by wollman@ (see 7b187005d18ef), and later reiterated
in 2006 by rwatson@ (see 6fbb9cf860dcd).
o Make struct domain hold a variable sized array of protosw pointers.
For most protocols these pointers are initialized statically.
Those domains that may have loadable protocols have spacers. IPv4
and IPv6 have 8 spacers each (andre@ dff3237ee54ea).
o For inetsw and inet6sw leave a comment noting that many protosw
entries very likely are dead code.
o Refactor pf_proto_[un]register() into protosw_[un]register().
o Isolate pr_*_notsupp() methods into uipc_domain.c

Reviewed by: melifaro
Differential revision: https://reviews.freebsd.org/D36232

Fix ipfw fwd that doesn't work in some cases

For IPv4 use dst pointer as destination address in fib4_lookup().
It keeps destination address from IPv4 header and can be changed
when PACKET_TAG_IPFORWARD tag was set by packet filter.

For IPv6 override destination address with address from dst_sa.sin6_addr,
that was set from PACKET_TAG_IPFORWARD tag.

Reviewed by: eugen
MFC after: 1 week
PR: 256828, 261697, 255705
Differential Revision: https://reviews.freebsd.org/D34732

ip_mroute: refactor epoch-basd locking

Remove duplicated epoch_enter and epoch_exit in IP inp/outp routines.
Remove unnecessary macros as well.

Obtained from: Semihalf
Spponsored by: Stormshield
Reviewed by: glebius
Differential revision: https://reviews.freebsd.org/D34030

Fix a memory leak when ip_output_send() returns EAGAIN due to send tag issues

When ip_output_send() returns EAGAIN due to issues with send tags (route
change, lagg failover, etc), it must free the mbuf. This is because
ip_output_send() was written as a wrapper/replacement for a direct
call to if_output(), and the contract with if_output() has
historically been that it owns the mbufs once called. When
ip_output_send() failed to free mbufs, it violated this assumption
and lead to leaked mbufs.

This was noticed when using NIC TLS in combination with hardware
rate-limited connections. When seeing lots of NIC output drops
triggered ratelimit send tag changes, we noticed we were leaking
ktls_sessions, send tags and mbufs. This was due ip_output_send()
leaking mbufs which held references to ktls_sessions, which in
turn held references to send tags.

Many thanks to jbh, rrs, hselasky and markj for their help in
debugging this.

Sponsored by: Netflix
Differential Revision: https://reviews.freebsd.org/D34054
Reviewed by: hselasky, jhb, rrs
MFC after: 2 weeks

netinet: Remove unneeded mb_unmapped_to_ext() calls

in_cksum_skip() now handles unmapped mbufs on platforms where they're
permitted.

Reviewed by: glebius, jhb
MFC after: 1 week
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D33097

sctp: Remove now-unneeded mb_unmapped_to_ext() calls

sctp_delayed_checksum() now handles unmapped mbufs, thanks to m_apply().

No functional change intended.

Reviewed by: tuexen
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D32942

Remove in_ifaddr_lock acquisiton to access in_ifaddrhead.

An IPv4 address is embedded into an ifaddr which is freed
via epoch. And the in_ifaddrhead is already a CK list. Use
the network epoch to protect against use after free.

Next step would be to CK-ify the in_addr hash and get rid of the...

Reviewed by: melifaro
Differential Revision: https://reviews.freebsd.org/D32434

routing: Allow using IPv6 next-hops for IPv4 routes (RFC 5549).

Implement kernel support for RFC 5549/8950.

* Relax control plane restrictions and allow specifying IPv6 gateways
for IPv4 routes. This behavior is controlled by the
net.route.rib_route_ipv6_nexthop sysctl (on by default).

* Always pass final destination in ro->ro_dst in ip_forward().

* Use ro->ro_dst to exract packet family inside if_output() routines.
Consistently use RO_GET_FAMILY() macro to handle ro=NULL case.

* Pass extracted family to nd6_resolve() to get the LLE with proper encap.
It leverages recent lltable changes committed in c541bd368f86.

Presence of the functionality can be checked using ipv4_rfc5549_support feature(3).
Example usage:
route add -net 192.0.0.0/24 -inet6 fe80::5054:ff:fe14:e319%vtnet0

Differential Revision: https://reviews.freebsd.org/D30398
MFC after: 2 weeks

Simplify nhop operations in ip_output().

Consistently use `nh` instead of always dereferencing
ro->ro_nh inside the if block.
Always use nexthop mtu, as it provides guarantee that mtu is accurate.
Pass `nh` pointer to rt_update_ro_flags() to allow upcoming uses
of updating ro flags based on different nexthop.

Differential Revision: https://reviews.freebsd.org/D31451
Reviewed by: kp
MFC after: 2 weeks

mroute: fix race condition during mrouter shutting down

There is a race condition between V_ip_mrouter de-init
and ip_mforward handling. It might happen that mrouted
is cleaned up after V_ip_mrouter check and before
processing packet in ip_mforward.
Use epoch call aproach, similar to IPSec which also handles
such case.

Reported by: Damien Deville
Obtained from: Stormshield
Reviewed by: mw
Differential Revision: https://reviews.freebsd.org/D29946

Catch up with 6edfd179c86: mechanically rename IFCAP_NOMAP to IFCAP_MEXTPG.

Originally IFCAP_NOMAP meant that the mbuf has external storage pointer
that points to unmapped address. Then, this was extended to array of
such pointers. Then, such mbufs were augmented with header/trailer.
Basically, extended mbufs are extended, and set of features is subject
to change. The new name should be generic enough to avoid further
renaming.

Add IP(V6)_VLAN_PCP to set 802.1 priority per-flow.

This adds a new IP_PROTO / IPV6_PROTO setsockopt (getsockopt)
option IP(V6)_VLAN_PCP, which can be set to -1 (interface
default), or explicitly to any priority between 0 and 7.

Note that for untagged traffic, explicitly adding a
priority will insert a special 801.1Q vlan header with
vlan ID = 0 to carry the priority setting

Reviewed by: gallatin, rrs
MFC after: 2 weeks
Sponsored by: NetApp, Inc.
Differential Revision: https://reviews.freebsd.org/D26409

Introduce scalable route multipath.

This change is based on the nexthop objects landed in D24232.

The change introduces the concept of nexthop groups.
Each group contains the collection of nexthops with their
relative weights and a dataplane-optimized structure to enable
efficient nexthop selection.

Simular to the nexthops, nexthop groups are immutable. Dataplane part
gets compiled during group creation and is basically an array of
nexthop pointers, compiled w.r.t their weights.

With this change, `rt_nhop` field of `struct rtentry` contains either
nexthop or nexthop group. They are distinguished by the presense of
NHF_MULTIPATH flag.
All dataplane lookup functions returns pointer to the nexthop object,
leaving nexhop groups details inside routing subsystem.

User-visible changes:

The change is intended to be backward-compatible: all non-mpath operations
should work as before with ROUTE_MPATH and net.route.multipath=1.

All routes now comes with weight, default weight is 1, maximum is 2^24-1.

Current maximum multipath group width is statically set to 64.
This will become sysctl-tunable in the followup changes.

Using functionality:
* Recompile kernel with ROUTE_MPATH
* set net.route.multipath to 1

route add -6 2001:db8::/32 2001:db8::2 -weight 10
route add -6 2001:db8::/32 2001:db8::3 -weight 20

netstat -6On

Nexthop groups data

Internet6:
GrpIdx NhIdx Weight Slots Gateway Netif Refcnt
1 ------- ------- ------- --------------------------------------- --------- 1
13 10 1 2001:db8::2 vlan2
14 20 2 2001:db8::3 vlan2

Next steps:
* Land outbound hashing for locally-originated routes ( D26523 ).
* Fix net/bird multipath (net/frr seems to work fine)
* Add ROUTE_MPATH to GENERIC
* Set net.route.multipath=1 by default

Tested by: olivier
Reviewed by: glebius
Relnotes: yes
Differential Revision: https://reviews.freebsd.org/D26449

Rework part of routing code to reduce difference to D26449.

* Split rt_setmetrics into get_info_weight() and rt_set_expire_info(),
as these two can be applied at different entities and at different times.
* Start filling route weight in route change notifications
* Pass flowid to UDP/raw IP route lookups
* Rework nd6_subscription_cb() and sysctl_dumpentry() to prepare for the fact
that rtentry can contain multiple nexthops.

Differential Revision: https://reviews.freebsd.org/D26497

Initialize some local variables earlier

Move the initialization of these variables to the beginning of their
respective functions.

On our end this creates a small amount of unneeded churn, as these
variables are properly initialized before their first use in all cases.
However, changing this benefits at least one downstream consumer
(NetApp) by allowing local and future modifications to these functions
to be made without worrying about where the initialization occurs.

Reviewed by: melifaro, rscheff
Sponsored by: NetApp, Inc.
Sponsored by: Klara, Inc.
Differential Revision: https://reviews.freebsd.org/D26454

if_vxlan(4): add support for hardware assisted checksumming, TSO, and RSS.

This lets a VXLAN pseudo-interface take advantage of hardware checksumming (tx
and rx), TSO, and RSS if the NIC is capable of performing these operations on
inner VXLAN traffic.

A VXLAN interface inherits the capabilities of its vxlandev interface if one is
specified or of the interface that hosts the vxlanlocal address. If other
interfaces will carry traffic for that VXLAN then they must have the same
hardware capabilities.

On transmit, if_vxlan verifies that the outbound interface has the required
capabilities and then translates the CSUM_ flags to their inner equivalents.
This tells the hardware ifnet that it needs to operate on the inner frame and
not the outer VXLAN headers.

An event is generated when a VXLAN ifnet starts. This allows hardware drivers to
configure their devices to expect VXLAN traffic on the specified incoming port.

On receive, the hardware does RSS and checksum verification on the inner frame.
if_vxlan now does a direct netisr dispatch to take full advantage of RSS. It is
not very clear why it didn't do this already.

Future work:
Rx: it should be possible to avoid the first trip up the protocol stack to get
the frame to if_vxlan just so it can decapsulate and requeue for a second trip
up the stack. The hardware NIC driver could directly call an if_vxlan receive
routine for VXLAN traffic instead.

Rx: LRO. depends on what happens with the previous item. There will have to to
be a mechanism to indicate that it's time for if_vxlan to flush its LRO state.

Reviewed by: kib@
Relnotes: Yes
Sponsored by: Chelsio Communications
Differential Revision: https://reviews.freebsd.org/D25873

net: clean up empty lines in .c and .h files

Add the SCTP_SUPPORT kernel option.

This is in preparation for enabling a loadable SCTP stack. Analogous to
IPSEC/IPSEC_SUPPORT, the SCTP_SUPPORT kernel option must be configured
in order to support a loadable SCTP implementation.

Discussed with: tuexen
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation

Switch ip_output/icmp_reflect rt lookup calls with fib4_lookup.

fib4_lookup_nh_ represents pre-epoch generation of fib api,
providing less guarantees over pointer validness and requiring
on-stack data copying.

Conversion is straight-forwarded, as the only 2 differences are
requirement of running in network epoch and the need to handle
RTF_GATEWAY case in the caller code.

Reviewed by: ae
Differential Revision: https://reviews.freebsd.org/D24976

Remove redundant checks for nhop validity.
Currently NH_IS_VALID() simly aliases to RT_LINK_IS_UP(), so we're
checking the same thing twice.

In the near future the implementation of this check will be simpler,
as there are plans to introduce control-plane interface status monitoring
similar to ipfw interface tracker.

Ktls: never skip stamping tags for NIC TLS

The newer RACK and BBR TCP stacks have added a mechanism
to disable hardware packet pacing for TCP retransmits.
This mechanism works by skipping the send-tag stamp
on rate-limited connections when the TCP stack calls
ip_output() with the IP_NO_SND_TAG_RL flag set.

When doing NIC TLS, we must ignore this flag, as
NIC TLS packets must always be stamped. Failure
to stamp a NIC TLS packet will result in crypto
issues.

Reviewed by: hselasky, rrs
Sponsored by: Netflix, Mellanox

Step 3: anonymize struct mbuf_ext_pgs and move all its fields into mbuf
within m_epg namespace.
All edits except the 'struct mbuf' declaration and mb_dupcl() were done
mechanically with sed:

s/->m_ext_pgs.nrdy/->m_epg_nrdy/g
s/->m_ext_pgs.hdr_len/->m_epg_hdrlen/g
s/->m_ext_pgs.trail_len/->m_epg_trllen/g
s/->m_ext_pgs.first_pg_off/->m_epg_1st_off/g
s/->m_ext_pgs.last_pg_len/->m_epg_last_len/g
s/->m_ext_pgs.flags/->m_epg_flags/g
s/->m_ext_pgs.record_type/->m_epg_record_type/g
s/->m_ext_pgs.enc_cnt/->m_epg_enc_cnt/g
s/->m_ext_pgs.tls/->m_epg_tls/g
s/->m_ext_pgs.so/->m_epg_so/g
s/->m_ext_pgs.seqno/->m_epg_seqno/g
s/->m_ext_pgs.stailq/->m_epg_stailq/g

Reviewed by: gallatin
Differential Revision: https://reviews.freebsd.org/D24598

Convert rtalloc_mpath_fib() users to the new KPI.

New fib[46]_lookup() functions support multipath transparently.
Given that, switch the last rtalloc_mpath_fib() calls to
dib4_lookup() and eliminate the function itself.

Note: proper flowid generation (especially for the outbound traffic) is a
bigger topic and will be handled in a separate review.
This change leaves flowid generation intact.

Differential Revision: https://reviews.freebsd.org/D24595

Convert route caching to nexthop caching.

This change is build on top of nexthop objects introduced in r359823.

Nexthops are separate datastructures, containing all necessary information
to perform packet forwarding such as gateway interface and mtu. Nexthops
are shared among the routes, providing more pre-computed cache-efficient
data while requiring less memory. Splitting the LPM code and the attached
data solves multiple long-standing problems in the routing layer,
drastically reduces the coupling with outher parts of the stack and allows
to transparently introduce faster lookup algorithms.

Route caching was (re)introduced to minimise (slow) routing lookups, allowing
for notably better performance for large TCP senders. Caching works by
acquiring rtentry reference, which is protected by per-rtentry mutex.
If the routing table is changed (checked by comparing the rtable generation id)
or link goes down, cache record gets withdrawn.

Nexthops have the same reference counting interface, backed by refcount(9).
This change merely replaces rtentry with the actual forwarding nextop as a
cached object, which is mostly mechanical. Other moving parts like cache
cleanup on rtable change remains the same.

Differential Revision: https://reviews.freebsd.org/D24340

KTLS: Re-work unmapped mbufs to carry ext_pgs in the mbuf itself.

While the original implementation of unmapped mbufs was a large
step forward in terms of reducing cache misses by enabling mbufs
to carry more than a single page for sendfile, they are rather
cache unfriendly when accessing the ext_pgs metadata and
data. This is because the ext_pgs part of the mbuf is allocated
separately, and almost guaranteed to be cold in cache.

This change takes advantage of the fact that unmapped mbufs
are never used at the same time as pkthdr mbufs. Given this
fact, we can overlap the ext_pgs metadata with the mbuf
pkthdr, and carry the ext_pgs meta directly in the mbuf itself.
Similarly, we can carry the ext_pgs data (TLS hdr/trailer/array
of pages) directly after the existing m_ext.

In order to be able to carry 5 pages (which is the minimum
required for a 16K TLS record which is not perfectly aligned) on
LP64, I've had to steal ext_arg2. The only user of this in the
xmit path is sendfile, and I've adjusted it to use arg1 when
using unmapped mbufs.

This change is almost entirely mechanical, except that we
change mb_alloc_ext_pgs() to no longer allow allocating
pkthdrs, the change to avoid ext_arg2 as mentioned above,
and the removal of the ext_pgs zone,

This change saves roughly 2% "raw" CPU (~59% -> 57%), or over
3% "scaled" CPU on a Netflix 100% software kTLS workload at
90+ Gb/s on Broadwell Xeons.

In a follow-on commit, I plan to remove some hacks to avoid
access ext_pgs fields of mbufs, since they will now be in
cache.

Many thanks to glebius for helping to make this better in
the Netflix tree.

Reviewed by: hselasky, jhb, rrs, glebius (early version)
Sponsored by: Netflix
Differential Revision: https://reviews.freebsd.org/D24213

Make ip6_output() and ip_output() require network epoch.

All callers that before may called into these functions
without network epoch now must enter it.

In r343631 error code for a packet blocked by a firewall was
changed from EACCES to EPERM. This change was not intentional,
so fix that. Return EACCESS if a firewall forbids sending.

Noticed by: ae

Revert most of the multicast changes from r353292. This needs a more
accurate approach.

Widen NET_EPOCH coverage.

When epoch(9) was introduced to network stack, it was basically
dropped in place of existing locking, which was mutexes and
rwlocks. For the sake of performance mutex covered areas were
as small as possible, so became epoch covered areas.

However, epoch doesn't introduce any contention, it just delays
memory reclaim. So, there is no point to minimise epoch covered
areas in sense of performance. Meanwhile entering/exiting epoch
also has non-zero CPU usage, so doing this less often is a win.

Not the least is also code maintainability. In the new paradigm
we can assume that at any stage of processing a packet, we are
inside network epoch. This makes coding both input and output
path way easier.

On output path we already enter epoch quite early - in the
ip_output(), in the ip6_output().

This patch does the same for the input path. All ISR processing,
network related callouts, other ways of packet injection to the
network stack shall be performed in net_epoch. Any leaf function
that walks network configuration now asserts epoch.

Tricky part is configuration code paths - ioctls, sysctls. They
also call into leaf functions, so some need to be changed.

This patch would introduce more epoch recursions (see EPOCH_TRACE)
than we had before. They will be cleaned up separately, as several
of them aren't trivial. Note, that unlike a lock recursion the
epoch recursion is safe and just wastes a bit of resources.

Reviewed by: gallatin, hselasky, cy, adrian, kristof
Differential Revision: https://reviews.freebsd.org/D19111

This commit adds BBR (Bottleneck Bandwidth and RTT) congestion control. This
is a completely separate TCP stack (tcp_bbr.ko) that will be built only if
you add the make options WITH_EXTRA_TCP_STACKS=1 and also include the option
TCPHPTS. You can also include the RATELIMIT option if you have a NIC interface that
supports hardware pacing, BBR understands how to use such a feature.

Note that this commit also adds in a general purpose time-filter which
allows you to have a min-filter or max-filter. A filter allows you to
have a low (or high) value for some period of time and degrade slowly
to another value has time passes. You can find out the details of
BBR by looking at the original paper at:

https://queue.acm.org/detail.cfm?id=3022184

or consult many other web resources you can find on the web
referenced by "BBR congestion control". It should be noted that
BBRv1 (which this is) does tend to unfairness in cases of small
buffered paths, and it will usually get less bandwidth in the case
of large BDP paths(when competing with new-reno or cubic flows). BBR
is still an active research area and we do plan on implementing V2
of BBR to see if it is an improvement over V1.

Sponsored by: Netflix Inc.
Differential Revision: https://reviews.freebsd.org/D21582

Add kernel-side support for in-kernel TLS.

KTLS adds support for in-kernel framing and encryption of Transport
Layer Security (1.0-1.2) data on TCP sockets. KTLS only supports
offload of TLS for transmitted data. Key negotation must still be
performed in userland. Once completed, transmit session keys for a
connection are provided to the kernel via a new TCP_TXTLS_ENABLE
socket option. All subsequent data transmitted on the socket is
placed into TLS frames and encrypted using the supplied keys.

Any data written to a KTLS-enabled socket via write(2), aio_write(2),
or sendfile(2) is assumed to be application data and is encoded in TLS
frames with an application data type. Individual records can be sent
with a custom type (e.g. handshake messages) via sendmsg(2) with a new
control message (TLS_SET_RECORD_TYPE) specifying the record type.

At present, rekeying is not supported though the in-kernel framework
should support rekeying.

KTLS makes use of the recently added unmapped mbufs to store TLS
frames in the socket buffer. Each TLS frame is described by a single
ext_pgs mbuf. The ext_pgs structure contains the header of the TLS
record (and trailer for encrypted records) as well as references to
the associated TLS session.

KTLS supports two primary methods of encrypting TLS frames: software
TLS and ifnet TLS.

Software TLS marks mbufs holding socket data as not ready via
M_NOTREADY similar to sendfile(2) when TLS framing information is
added to an unmapped mbuf in ktls_frame(). ktls_enqueue() is then
called to schedule TLS frames for encryption. In the case of
sendfile_iodone() calls ktls_enqueue() instead of pru_ready() leaving
the mbufs marked M_NOTREADY until encryption is completed. For other
writes (vn_sendfile when pages are available, write(2), etc.), the
PRUS_NOTREADY is set when invoking pru_send() along with invoking
ktls_enqueue().

A pool of worker threads (the "KTLS" kernel process) encrypts TLS
frames queued via ktls_enqueue(). Each TLS frame is temporarily
mapped using the direct map and passed to a software encryption
backend to perform the actual encryption.

(Note: The use of PHYS_TO_DMAP could be replaced with sf_bufs if
someone wished to make this work on architectures without a direct
map.)

KTLS supports pluggable software encryption backends. Internally,
Netflix uses proprietary pure-software backends. This commit includes
a simple backend in a new ktls_ocf.ko module that uses the kernel's
OpenCrypto framework to provide AES-GCM encryption of TLS frames. As
a result, software TLS is now a bit of a misnomer as it can make use
of hardware crypto accelerators.

Once software encryption has finished, the TLS frame mbufs are marked
ready via pru_ready(). At this point, the encrypted data appears as
regular payload to the TCP stack stored in unmapped mbufs.

ifnet TLS permits a NIC to offload the TLS encryption and TCP
segmentation. In this mode, a new send tag type (IF_SND_TAG_TYPE_TLS)
is allocated on the interface a socket is routed over and associated
with a TLS session. TLS records for a TLS session using ifnet TLS are
not marked M_NOTREADY but are passed down the stack unencrypted. The
ip_output_send() and ip6_output_send() helper functions that apply
send tags to outbound IP packets verify that the send tag of the TLS
record matches the outbound interface. If so, the packet is tagged
with the TLS send tag and sent to the interface. The NIC device
driver must recognize packets with the TLS send tag and schedule them
for TLS encryption and TCP segmentation. If the the outbound
interface does not match the interface in the TLS send tag, the packet
is dropped. In addition, a task is scheduled to refresh the TLS send
tag for the TLS session. If a new TLS send tag cannot be allocated,
the connection is dropped. If a new TLS send tag is allocated,
however, subsequent packets will be tagged with the correct TLS send
tag. (This latter case has been tested by configuring both ports of a
Chelsio T6 in a lagg and failing over from one port to another. As
the connections migrated to the new port, new TLS send tags were
allocated for the new port and connections resumed without being
dropped.)

ifnet TLS can be enabled and disabled on supported network interfaces
via new '[-]txtls[46]' options to ifconfig(8). ifnet TLS is supported
across both vlan devices and lagg interfaces using failover, lacp with
flowid enabled, or lacp with flowid enabled.

Applications may request the current KTLS mode of a connection via a
new TCP_TXTLS_MODE socket option. They can also use this socket
option to toggle between software and ifnet TLS modes.

In addition, a testing tool is available in tools/tools/switch_tls.
This is modeled on tcpdrop and uses similar syntax. However, instead
of dropping connections, -s is used to force KTLS connections to
switch to software TLS and -i is used to switch to ifnet TLS.

Various sysctls and counters are available under the kern.ipc.tls
sysctl node. The kern.ipc.tls.enable node must be set to true to
enable KTLS (it is off by default). The use of unmapped mbufs must
also be enabled via kern.ipc.mb_use_ext_pgs to enable KTLS.

KTLS is enabled via the KERN_TLS kernel option.

This patch is the culmination of years of work by several folks
including Scott Long and Randall Stewart for the original design and
implementation; Drew Gallatin for several optimizations including the
use of ext_pgs mbufs, the M_NOTREADY mechanism for TLS records
awaiting software encryption, and pluggable software crypto backends;
and John Baldwin for modifications to support hardware TLS offload.

Reviewed by: gallatin, hselasky, rrs
Obtained from: Netflix
Sponsored by: Netflix, Chelsio Communications
Differential Revision: https://reviews.freebsd.org/D21277

Add an external mbuf buffer type that holds multiple unmapped pages.

Unmapped mbufs allow sendfile to carry multiple pages of data in a
single mbuf, without mapping those pages. It is a requirement for
Netflix's in-kernel TLS, and provides a 5-10% CPU savings on heavy web
serving workloads when used by sendfile, due to effectively
compressing socket buffers by an order of magnitude, and hence
reducing cache misses.

For this new external mbuf buffer type (EXT_PGS), the ext_buf pointer
now points to a struct mbuf_ext_pgs structure instead of a data
buffer. This structure contains an array of physical addresses (this
reduces cache misses compared to an earlier version that stored an
array of vm_page_t pointers). It also stores additional fields needed
for in-kernel TLS such as the TLS header and trailer data that are
currently unused. To more easily detect these mbufs, the M_NOMAP flag
is set in m_flags in addition to M_EXT.

Various functions like m_copydata() have been updated to safely access
packet contents (using uiomove_fromphys()), to make things like BPF
safe.

NIC drivers advertise support for unmapped mbufs on transmit via a new
IFCAP_NOMAP capability. This capability can be toggled via the new
'nomap' and '-nomap' ifconfig(8) commands. For NIC drivers that only
transmit packet contents via DMA and use bus_dma, adding the
capability to if_capabilities and if_capenable should be all that is
required.

If a NIC does not support unmapped mbufs, they are converted to a
chain of mapped mbufs (using sf_bufs to provide the mapping) in
ip_output or ip6_output. If an unmapped mbuf requires software
checksums, it is also converted to a chain of mapped mbufs before
computing the checksum.

Submitted by: gallatin (earlier version)
Reviewed by: gallatin, hselasky, rrs
Discussed with: ae, kp (firewalls)
Relnotes: yes
Sponsored by: Netflix
Differential Revision: https://reviews.freebsd.org/D20616

ip_output: pass PFIL_FWD in the slow path

If we take the slow path for forwarding we should still tell our
firewalls (hooked through pfil(9)) that we're forwarding. Pass the
ip_output() flags to ip_output_pfil() so it can set the PFIL_FWD flag
when we're forwarding.

MFC after: 1 week
Sponsored by: Axiado

Sort opt_foo.h #includes and add a missing blank line in ip_output().

Restructure mbuf send tags to provide stronger guarantees.

- Perform ifp mismatch checks (to determine if a send tag is allocated
for a different ifp than the one the packet is being output on), in
ip_output() and ip6_output(). This avoids sending packets with send
tags to ifnet drivers that don't support send tags.

Since we are now checking for ifp mismatches before invoking
if_output, we can now try to allocate a new tag before invoking
if_output sending the original packet on the new tag if allocation
succeeds.

To avoid code duplication for the fragment and unfragmented cases,
add ip_output_send() and ip6_output_send() as wrappers around
if_output and nd6_output_ifp, respectively. All of the logic for
setting send tags and dealing with send tag-related errors is done
in these wrapper functions.

For pseudo interfaces that wrap other network interfaces (vlan and
lagg), wrapper send tags are now allocated so that ip*_output see
the wrapper ifp as the ifp in the send tag. The if_transmit
routines rewrite the send tags after performing an ifp mismatch
check. If an ifp mismatch is detected, the transmit routines fail
with EAGAIN.

- To provide clearer life cycle management of send tags, especially
in the presence of vlan and lagg wrapper tags, add a reference count
to send tags managed via m_snd_tag_ref() and m_snd_tag_rele().
Provide a helper function (m_snd_tag_init()) for use by drivers
supporting send tags. m_snd_tag_init() takes care of the if_ref
on the ifp meaning that code alloating send tags via if_snd_tag_alloc
no longer has to manage that manually. Similarly, m_snd_tag_rele
drops the refcount on the ifp after invoking if_snd_tag_free when
the last reference to a send tag is dropped.

This also closes use after free races if there are pending packets in
driver tx rings after the socket is closed (e.g. from tcpdrop).

In order for m_free to work reliably, add a new CSUM_SND_TAG flag in
csum_flags to indicate 'snd_tag' is set (rather than 'rcvif').
Drivers now also check this flag instead of checking snd_tag against
NULL. This avoids false positive matches when a forwarded packet
has a non-NULL rcvif that was treated as a send tag.

- cxgbe was relying on snd_tag_free being called when the inp was
detached so that it could kick the firmware to flush any pending
work on the flow. This is because the driver doesn't require ACK
messages from the firmware for every request, but instead does a
kind of manual interrupt coalescing by only setting a flag to
request a completion on a subset of requests. If all of the
in-flight requests don't have the flag when the tag is detached from
the inp, the flow might never return the credits. The current
snd_tag_free command issues a flush command to force the credits to
return. However, the credit return is what also frees the mbufs,
and since those mbufs now hold references on the tag, this meant
that snd_tag_free would never be called.

To fix, explicitly drop the mbuf's reference on the snd tag when the
mbuf is queued in the firmware work queue. This means that once the
inp's reference on the tag goes away and all in-flight mbufs have
been queued to the firmware, tag's refcount will drop to zero and
snd_tag_free will kick in and send the flush request. Note that we
need to avoid doing this in the middle of ethofld_tx(), so the
driver grabs a temporary reference on the tag around that loop to
defer the free to the end of the function in case it sends the last
mbuf to the queue after the inp has dropped its reference on the
tag.

- mlx5 preallocates send tags and was using the ifp pointer even when
the send tag wasn't in use. Explicitly use the ifp from other data
structures instead.

- Sprinkle some assertions in various places to assert that received
packets don't have a send tag, and that other places that overwrite
rcvif (e.g. 802.11 transmit) don't clobber a send tag pointer.

Reviewed by: gallatin, hselasky, rgrimes, ae
Sponsored by: Netflix
Differential Revision: https://reviews.freebsd.org/D20117

Fix regression from r347375: do not panic when sending an IP multicast
packet from an interface that doesn't have IPv4 address.

Reported by: Michael Butler <imb protected-networks.net>

Existense of PCB route caching doesn't allow us to use new fast route
lookup KPI in ip_output() like it is already used in ip_forward().
However, when there is no PCB provided we can use fast KPI, gaining
performance advantage.

Typical case when ip_output() is called without a PCB pointer is a
sendto(2) on a not connected UDP socket. In practice DNS servers do
this.

Reviewed by: melifaro
Differential Revision: https://reviews.freebsd.org/D19804

Track TCP connection's NUMA domain in the inpcb

Drivers can now pass up numa domain information via the
mbuf numa domain field. This information is then used
by TCP syncache_socket() to associate that information
with the inpcb. The domain information is then fed back
into transmitted mbufs in ip{6}_output(). This mechanism
is nearly identical to what is done to track RSS hash values
in the inp_flowid.

Follow on changes will use this information for lacp egress
port selection, binding TCP pacers to the appropriate NUMA
domain, etc.

Reviewed by: markj, kib, slavash, bz, scottl, jtl, tuexen
Sponsored by: Netflix
Differential Revision: https://reviews.freebsd.org/D20028

Use IN_foo() macros from sys/netinet/in.h inplace of handcrafted code

There are a few places that use hand crafted versions of the macros
from sys/netinet/in.h making it difficult to actually alter the
values in use by these macros. Correct that by replacing handcrafted
code with proper macro usage.

Reviewed by: karels, kristof
Approved by: bde (mentor)
MFC after: 3 weeks
Sponsored by: John Gilmore
Differential Revision: https://reviews.freebsd.org/D19317

New pfil(9) KPI together with newborn pfil API and control utility.

The KPI have been reviewed and cleansed of features that were planned
back 20 years ago and never implemented. The pfil(9) internals have
been made opaque to protocols with only returned types and function
declarations exposed. The KPI is made more strict, but at the same time
more extensible, as kernel uses same command structures that userland
ioctl uses.

In nutshell [KA]PI is about declaring filtering points, declaring
filters and linking and unlinking them together.

New [KA]PI makes it possible to reconfigure pfil(9) configuration:
change order of hooks, rehook filter from one filtering point to a
different one, disconnect a hook on output leaving it on input only,
prepend/append a filter to existing list of filters.

Now it possible for a single packet filter to provide multiple rulesets
that may be linked to different points. Think of per-interface ACLs in
Cisco or Juniper. None of existing packet filters yet support that,
however limited usage is already possible, e.g. default ruleset can
be moved to single interface, as soon as interface would pride their
filtering points.

Another future feature is possiblity to create pfil heads, that provide
not an mbuf pointer but just a memory pointer with length. That would
allow filtering at very early stages of a packet lifecycle, e.g. when
packet has just been received by a NIC and no mbuf was yet allocated.

Differential Revision: https://reviews.freebsd.org/D18951

Fix getsockopt() for IP_OPTIONS/IP_RETOPTS.

r336616 copies inp->inp_options using the m_dup() function.
However, this function expects an mbuf packet header at the beginning,
which is not true in this case.
Therefore, use m_copym() instead of m_dup().

This issue was found by syzkaller.
Reviewed by: mmacy@
MFC after: 1 week
Sponsored by: Netflix, Inc.
Differential Revision: https://reviews.freebsd.org/D18753

Mechanical cleanup of epoch(9) usage in network stack.

- Remove macros that covertly create epoch_tracker on thread stack. Such
macros a quite unsafe, e.g. will produce a buggy code if same macro is
used in embedded scopes. Explicitly declare epoch_tracker always.

- Unmask interface list IFNET_RLOCK_NOSLEEP(), interface address list
IF_ADDR_RLOCK() and interface AF specific data IF_AFDATA_RLOCK() read
locking macros to what they actually are - the net_epoch.
Keeping them as is is very misleading. They all are named FOO_RLOCK(),
while they no longer have lock semantics. Now they allow recursion and
what's more important they now no longer guarantee protection against
their companion WLOCK macros.
Note: INP_HASH_RLOCK() has same problems, but not touched by this commit.

This is non functional mechanical change. The only functionally changed
functions are ni6_addrs() and ni6_store_addrs(), where we no longer enter
epoch recursively.

Discussed with: jtl, gallatin

Ensure that the ips_localout counter is incremented for
locally generated SCTP packets sent over IPv4. This make
the behaviour consistent with IPv6.

Reviewed by: ae@, bz@, jtl@
Approved by: re (kib@)
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D17406

Convert UDP length to host byte order

When getting the number of bytes to checksum make sure to convert the UDP
length to host byte order when the entire header is not in the first mbuf.

Reviewed by: jtl, tuexen, ae
Approved by: re (gjb), jtl (mentor)
Differential Revision: https://reviews.freebsd.org/D17357

Fix a potential use after free in getsockopt() access to inp_options

Discussed with: jhb
Reviewed by: sbruno, transport
MFC after: 2 weeks
Sponsored by: Limelight Networks
Differential Revision: https://reviews.freebsd.org/D14621

There was quite a bit of feedback on r336282 that has led to the
submitter to want to revert it.

Fixup memory management for fetching options in ip_ctloutput()

Submitted by: Jason Eggleston <jason@eggnet.com>
Sponsored by: Limelight Networks
Differential Revision: https://reviews.freebsd.org/D14621

Load balance sockets with new SO_REUSEPORT_LB option.

This patch adds a new socket option, SO_REUSEPORT_LB, which allow multiple
programs or threads to bind to the same port and incoming connections will be
load balanced using a hash function.

Most of the code was copied from a similar patch for DragonflyBSD.

However, in DragonflyBSD, load balancing is a global on/off setting and can not
be set per socket. This patch allows for simultaneous use of both the current
SO_REUSEPORT and the new SO_REUSEPORT_LB options on the same system.

Required changes to structures:
Globally change so_options from 16 to 32 bit value to allow for more options.
Add hashtable in pcbinfo to hold all SO_REUSEPORT_LB sockets.

Limitations:
As DragonflyBSD, a load balance group is limited to 256 pcbs (256 programs or
threads sharing the same socket).

This is a substantially different contribution as compared to its original
incarnation at svn r332894 and reverted at svn r332967. Thanks to rwatson@
for the substantive feedback that is included in this commit.

Submitted by: Johannes Lundberg <johalun0@gmail.com>
Obtained from: DragonflyBSD
Relnotes: Yes
Sponsored by: Limelight Networks
Differential Revision: https://reviews.freebsd.org/D11003

Make in_delayed_cksum() be similar to IPv6 implementation.

Use m_copyback() function to write checksum when it isn't located
in the first mbuf of the chain. Handmade analog doesn't handle the
case when parts of checksum are located in different mbufs.
Also in case when mbuf is too short, m_copyback() will allocate new
mbuf in the chain instead of making out of bounds write.

Also wrap long line and remove now useless KASSERTs.

X-MFC after: r334705

Use UDP len when calculating UDP checksums

The length of the IP payload is normally equal to the UDP length, UDP Options
(draft-ietf-tsvwg-udp-options-02) suggests using the difference between IP
length and UDP length to create space for trailing data.

Correct checksum length calculation to use the UDP length rather than the IP
length when not offloading UDP checksums.

Approved by: jtl (mentor)
Differential Revision: https://reviews.freebsd.org/D15222

UDP: further performance improvements on tx

Cumulative throughput while running 64
netperf -H $DUT -t UDP_STREAM -- -m 1
on a 2x8x2 SKL went from 1.1Mpps to 2.5Mpps

Single stream throughput increases from 910kpps to 1.18Mpps

Baseline:
https://people.freebsd.org/~mmacy/2018.05.11/udpsender2.svg

- Protect read access to global ifnet list with epoch
https://people.freebsd.org/~mmacy/2018.05.11/udpsender3.svg

- Protect short lived ifaddr references with epoch
https://people.freebsd.org/~mmacy/2018.05.11/udpsender4.svg

- Convert if_afdata read lock path to epoch
https://people.freebsd.org/~mmacy/2018.05.11/udpsender5.svg

A fix for the inpcbhash contention is pending sufficient time
on a canary at LLNW.

Reviewed by: gallatin
Sponsored by: Limelight Networks
Differential Revision: https://reviews.freebsd.org/D15409

Revert r332894 at the request of the submitter.

Submitted by: Johannes Lundberg <johalun0_gmail.com>
Sponsored by: Limelight Networks

Load balance sockets with new SO_REUSEPORT_LB option

This patch adds a new socket option, SO_REUSEPORT_LB, which allow multiple
programs or threads to bind to the same port and incoming connections will be
load balanced using a hash function.

Most of the code was copied from a similar patch for DragonflyBSD.

However, in DragonflyBSD, load balancing is a global on/off setting and can not
be set per socket. This patch allows for simultaneous use of both the current
SO_REUSEPORT and the new SO_REUSEPORT_LB options on the same system.

Required changes to structures
Globally change so_options from 16 to 32 bit value to allow for more options.
Add hashtable in pcbinfo to hold all SO_REUSEPORT_LB sockets.

Limitations
As DragonflyBSD, a load balance group is limited to 256 pcbs
(256 programs or threads sharing the same socket).

Submitted by: Johannes Lundberg <johanlun0@gmail.com>
Sponsored by: Limelight Networks
Differential Revision: https://reviews.freebsd.org/D11003

Revert r331379 as the "simple" lock changes have revealed a deeper problem
and need for a rethink.

Submitted by: Jason Eggleston <jason@eggnet.com>
Sponsored by: Limelight Networks

netpfil: Introduce PFIL_FWD flag

Forwarded packets passed through PFIL_OUT, which made it difficult for
firewalls to figure out if they were forwarding or producing packets. This in
turn is an issue for pf for IPv6 fragment handling: it needs to call
ip6_output() or ip6_forward() to handle the fragments. Figuring out which was
difficult (and until now, incorrect).
Having pfil distinguish the two removes an ugly piece of code from pf.

Introduce a new variant of the netpfil callbacks with a flags variable, which
has PFIL_FWD set for forwarded packets. This allows pf to reliably work out if
a packet is forwarded.

Reviewed by: ae, kevans
Differential Revision: https://reviews.freebsd.org/D13715

Simple locking fixes in ip_ctloutput, ip6_ctloutput, rip_ctloutput.

Submitted by: Jason Eggleston <jason@eggnet.com>
Sponsored by: Limelight Networks
Differential Revision: https://reviews.freebsd.org/D14624

Reduce code duplication for inpcb route caching

Add a new macro to clear both the L3 and L2 route caches, to
hopefully prevent future instances where only the L3 cache was
cleared when both should have been.

MFC after: 1 week
Sponsored by: Dell EMC Isilon
Differential Revision: https://reviews.freebsd.org/D13989
Reviewed by: karels

sys: further adoption of SPDX licensing ID tags.

Mainly focus on files that use BSD 3-Clause license.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.

Special thanks to Wind River for providing access to "The Duke of
Highlander" tool: an older (2014) run over FreeBSD tree was useful as a
starting point.

After inpcb route caching was put back in place there is no need for
flowtable anymore (as flowtable was never considered to be useful in
the forwarding path).

Reviewed by: np
Differential Revision: https://reviews.freebsd.org/D11448

Fix reference count leak with L2 caching.

ip_forward, TCP/IPv6, and probably SCTP leaked references to L2 cache
entry because they used their own routes on the stack, not in_pcb routes.
The original model for route caching was callers that provided a route
structure to ip{,6}input() would keep the route, and this model was used
for L2 caching as well. Instead, change L2 caching to be done by default
only when using a route structure in the in_pcb; the pcb deallocation
code frees L2 as well as L3 cacches. A separate change will add route
caching to TCP/IPv6.

Another suggestion was to have the transport protocols indicate willingness
to use L2 caching, but this approach keeps the changes in the network
level

Reviewed by: ae gnn
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D10059

The patch provides the same socket option as Linux IP_ORIGDSTADDR.
Unfortunately they will have different integer value due to Linux value being already assigned in FreeBSD.

The patch is similar to IP_RECVDSTADDR but also provides the destination port value to the application.

This allows/improves implementation of transparent proxies on UDP sockets due to having the whole information on forwarded packets.

Reviewed by: adrian, aw
Approved by: ae (mentor)
Sponsored by: rsync.net
Differential Revision: D9235

Renumber copyright clause 4

Renumber cluase 4 to 3, per what everybody else did when BSD granted
them permission to remove clause 3. My insistance on keeping the same
numbering for legal reasons is too pedantic, so give up on that point.

Submitted by: Jan Schaumann <jschauma@stevens.edu>
Pull Request: https://github.com/freebsd/freebsd/pull/96

Committed without approval from mentor.

Reported by: gnn

The patch provides the same socket option as Linux IP_ORIGDSTADDR.
Unfortunately they will have different integer value due to Linux value being already assigned in FreeBSD.

The patch is similar to IP_RECVDSTADDR but also provides the destination port value to the application.

This allows/improves implementation of transparent proxies on UDP sockets due to having the whole information on forwarded packets.

Sponsored-by: rsync.net
Differential Revision: D9235
Reviewed-by: adrian

Merge projects/ipsec into head/.

Small summary
-------------

o Almost all IPsec releated code was moved into sys/netipsec.
o New kernel modules added: ipsec.ko and tcpmd5.ko. New kernel
option IPSEC_SUPPORT added. It enables support for loading
and unloading of ipsec.ko and tcpmd5.ko kernel modules.
o IPSEC_NAT_T option was removed. Now NAT-T support is enabled by
default. The UDP_ENCAP_ESPINUDP_NON_IKE encapsulation type
support was removed. Added TCP/UDP checksum handling for
inbound packets that were decapsulated by transport mode SAs.
setkey(8) modified to show run-time NAT-T configuration of SA.
o New network pseudo interface if_ipsec(4) added. For now it is
build as part of ipsec.ko module (or with IPSEC kernel).
It implements IPsec virtual tunnels to create route-based VPNs.
o The network stack now invokes IPsec functions using special
methods. The only one header file <netipsec/ipsec_support.h>
should be included to declare all the needed things to work
with IPsec.
o All IPsec protocols handlers (ESP/AH/IPCOMP protosw) were removed.
Now these protocols are handled directly via IPsec methods.
o TCP_SIGNATURE support was reworked to be more close to RFC.
o PF_KEY SADB was reworked:
- now all security associations stored in the single SPI namespace,
and all SAs MUST have unique SPI.
- several hash tables added to speed up lookups in SADB.
- SADB now uses rmlock to protect access, and concurrent threads
can do SA lookups in the same time.
- many PF_KEY message handlers were reworked to reflect changes
in SADB.
- SADB_UPDATE message was extended to support new PF_KEY headers:
SADB_X_EXT_NEW_ADDRESS_SRC and SADB_X_EXT_NEW_ADDRESS_DST. They
can be used by IKE daemon to change SA addresses.
o ipsecrequest and secpolicy structures were cardinally changed to
avoid locking protection for ipsecrequest. Now we support
only limited number (4) of bundled SAs, but they are supported
for both INET and INET6.
o INPCB security policy cache was introduced. Each PCB now caches
used security policies to avoid SP lookup for each packet.
o For inbound security policies added the mode, when the kernel does
check for full history of applied IPsec transforms.
o References counting rules for security policies and security
associations were changed. The proper SA locking added into xform
code.
o xform code was also changed. Now it is possible to unregister xforms.
tdb_xxx structures were changed and renamed to reflect changes in
SADB/SPDB, and changed rules for locking and refcounting.

Reviewed by: gnn, wblock
Obtained from: Yandex LLC
Relnotes: yes
Sponsored by: Yandex LLC
Differential Revision: https://reviews.freebsd.org/D9352

Implement kernel support for hardware rate limited sockets.

- Add RATELIMIT kernel configuration keyword which must be set to
enable the new functionality.

- Add support for hardware driven, Receive Side Scaling, RSS aware, rate
limited sendqueues and expose the functionality through the already
established SO_MAX_PACING_RATE setsockopt(). The API support rates in
the range from 1 to 4Gbytes/s which are suitable for regular TCP and
UDP streams. The setsockopt(2) manual page has been updated.

- Add rate limit function callback API to "struct ifnet" which supports
the following operations: if_snd_tag_alloc(), if_snd_tag_modify(),
if_snd_tag_query() and if_snd_tag_free().

- Add support to ifconfig to view, set and clear the IFCAP_TXRTLMT
flag, which tells if a network driver supports rate limiting or not.

- This patch also adds support for rate limiting through VLAN and LAGG
intermediate network devices.

- How rate limiting works:

1) The userspace application calls setsockopt() after accepting or
making a new connection to set the rate which is then stored in the
socket structure in the kernel. Later on when packets are transmitted
a check is made in the transmit path for rate changes. A rate change
implies a non-blocking ifp->if_snd_tag_alloc() call will be made to the
destination network interface, which then sets up a custom sendqueue
with the given rate limitation parameter. A "struct m_snd_tag" pointer is
returned which serves as a "snd_tag" hint in the m_pkthdr for the
subsequently transmitted mbufs.

2) When the network driver sees the "m->m_pkthdr.snd_tag" different
from NULL, it will move the packets into a designated rate limited sendqueue
given by the snd_tag pointer. It is up to the individual drivers how the rate
limited traffic will be rate limited.

3) Route changes are detected by the NIC drivers in the ifp->if_transmit()
routine when the ifnet pointer in the incoming snd_tag mismatches the
one of the network interface. The network adapter frees the mbuf and
returns EAGAIN which causes the ip_output() to release and clear the send
tag. Upon next ip_output() a new "snd_tag" will be tried allocated.

4) When the PCB is detached the custom sendqueue will be released by a
non-blocking ifp->if_snd_tag_free() call to the currently bound network
interface.

Reviewed by: wblock (manpages), adrian, gallatin, scottl (network)
Differential Revision: https://reviews.freebsd.org/D3687
Sponsored by: Mellanox Technologies
MFC after: 3 months

When we are sending IP fragments, update ip pointers in IP_PROBE() for
each fragment.

MFC after: 1 week

Fix ip_output() on point-to-point links

In r304435, ip_output() was changed to use the result of the route
lookup to decide whether the outgoing packet was a broadcast or
not. This introduced a regression on interfaces where
IFF_BROADCAST was not set (e.g. point-to-point links), as the
algorithm could incorrectly treat the destination address as a
broadcast address, and ip_output() would subsequently drop the
packet as broadcasting on a non-IFF_BROADCAST interface is not
allowed.

Differential Revision: https://reviews.freebsd.org/D8303
Reviewed by: jtl
Reported by: ambrisko
MFC after: 2 weeks
X-MFC-With: r304435
Sponsored by: Dell EMC Isilon

- Revert r300854, r303657 which tried to fix regression from r297225.
- Fix the regression proper way using RO_RTFREE().

Submitted by: ae

Don't iterate over the ifnet addr list in ip_output()

For almost every packet that is transmitted through ip_output(),
a call to in_broadcast() was made to decide if the destination
IP was a broadcast address. in_broadcast() iterates over the
ifnet's address to find a source IP matching the subnet of the
destination IP, and then checks if the IP is a broadcast in that
subnet.

This is completely redundant as we have already performed the
route lookup, so the source IP is already known. Just use that
address to directly check whether the destination IP is a
broadcast address or not.

MFC after: 2 months
Sponsored By: EMC / Isilon Storage Division
Differential Revision: https://reviews.freebsd.org/D7266

Cleanup unneded include "opt_ipfw.h".

It was used for conditional build IPFIREWALL_FORWARD support.
But IPFIREWALL_FORWARD option was removed a long time ago.

This change re-adds L2 caching for TCP and UDP, as originally added in D4306
but removed due to other changes in the system. Restore the llentry pointer
to the "struct route", and use it to cache the L2 lookup (ARP or ND6) as
appropriate.

Submitted by: Mike Karels
Differential Revision: https://reviews.freebsd.org/D6262

Plug route reference underleak that happens with FLOWTABLE after r297225.

Submitted by: Mike Karels <mike karels.net>

netinet: for pointers replace 0 with NULL.

These are mostly cosmetical, no functional change.

Found with devel/coccinelle.

Reviewed by: ae. tuexen

FreeBSD previously provided route caching for TCP (and UDP). Re-add
route caching for TCP, with some improvements. In particular, invalidate
the route cache if a new route is added, which might be a better match.
The cache is automatically invalidated if the old route is deleted.

Submitted by: Mike Karels
Reviewed by: gnn
Differential Revision: https://reviews.freebsd.org/D4306

Finish r275196: do not dereference rtentry in if_output() routines.

The only piece of information that is required is rt_flags subset.

In particular, if_loop() requires RTF_REJECT and RTF_BLACKHOLE flags
to check if this particular mbuf needs to be dropped (and what
error should be returned).
Note that if_loop() will always return EHOSTUNREACH for "reject" routes
regardless of RTF_HOST flag existence. This is due to upcoming routing
changes where RTF_HOST value won't be available as lookup result.

All other functions require RTF_GATEWAY flag to check if they need
to return EHOSTUNREACH instead of EHOSTDOWN error.

There are 11 places where non-zero 'struct route' is passed to if_output().
For most of the callers (forwarding, bpf, arp) does not care about exact
error value. In fact, the only place where this result is propagated
is ip_output(). (ip6_output() passes NULL route to nd6_output_ifp()).

Given that, add 3 new 'struct route' flags (RT_REJECT, RT_BLACKHOLE and
RT_IS_GW) and inline function (rt_update_ro_flags()) to copy necessary
rte flags to ro_flags. Call this function in ip_output() after looking up/
verifying rte.

Reviewed by: ae

Implement interface link header precomputation API.

Add if_requestencap() interface method which is capable of calculating
various link headers for given interface. Right now there is support
for INET/INET6/ARP llheader calculation (IFENCAP_LL type request).
Other types are planned to support more complex calculation
(L2 multipath lagg nexthops, tunnel encap nexthops, etc..).

Reshape 'struct route' to be able to pass additional data (with is length)
to prepend to mbuf.

These two changes permits routing code to pass pre-calculated nexthop data
(like L2 header for route w/gateway) down to the stack eliminating the
need for other lookups. It also brings us closer to more complex scenarios
like transparently handling MPLS nexthops and tunnel interfaces.
Last, but not least, it removes layering violation introduced by flowtable
code (ro_lle) and simplifies handling of existing if_output consumers.

ARP/ND changes:
Make arp/ndp stack pre-calculate link header upon installing/updating lle
record. Interface link address change are handled by re-calculating
headers for all lles based on if_lladdr event. After these changes,
arpresolve()/nd6_resolve() returns full pre-calculated header for
supported interfaces thus simplifying if_output().
Move these lookups to separate ether_resolve_addr() function which ether
returs error or fully-prepared link header. Add <arp|nd6_>resolve_addr()
compat versions to return link addresses instead of pre-calculated data.

BPF changes:
Raw bpf writes occupied _two_ cases: AF_UNSPEC and pseudo_AF_HDRCMPLT.
Despite the naming, both of there have ther header "complete". The only
difference is that interface source mac has to be filled by OS for
AF_UNSPEC (controlled via BIOCGHDRCMPLT). This logic has to stay inside
BPF and not pollute if_output() routines. Convert BPF to pass prepend data
via new 'struct route' mechanism. Note that it does not change
non-optimized if_output(): ro_prepend handling is purely optional.
Side note: hackish pseudo_AF_HDRCMPLT is supported for ethernet and FDDI.
It is not needed for ethernet anymore. The only remaining FDDI user is
dev/pdq mostly untouched since 2007. FDDI support was eliminated from
OpenBSD in 2013 (sys/net/if_fddisubr.c rev 1.65).

Flowtable changes:
Flowtable violates layering by saving (and not correctly managing)
rtes/lles. Instead of passing lle pointer, pass pointer to pre-calculated
header data from that lle.

Differential Revision: https://reviews.freebsd.org/D4102

Simplify ip[6] simploop:
Do not pass 'dst' sockaddr to ip[6]_mloopback:
- We have explicit check for AF_INET in ip_output()
- We assume ip header inside passed mbuf in ip_mloopback
- We assume ip6 header inside passed mbuf in ip6_mloopback

The mbuf parameter to ip_output_pfil() must be an output parameter since
pfil(9) hooks may modify the chain.

X-MFC-With: r286028

Avoid double reference decrement when firewalls force relooping of packets

When firewalls force a reloop of packets and the caller supplied a route the reference to the route might be reduced twice creating issues.
This is especially the scenario when a packet is looped because of operation in the firewall but the new route lookup gives a down route.

Differential Revision: https://reviews.freebsd.org/D3037
Reviewed by: gnn
Approved by: gnn(mentor)

ip_output normalization and fixes

ip_output has a big chunk of code used to handle special cases with pfil consumers which also forces a reloop on it.
Gather all this code together to make it readable and properly handle the reloop cases.

Some of the issues identified:

M_IP_NEXTHOP is not handled properly in existing code.
route reference leaking is possible with in FIB number change
route flags checking is not consistent in the function

Differential Revision: https://reviews.freebsd.org/D3022
Reviewed by: gnn
Approved by: gnn(mentor)
MFC after: 4 weeks

Convert in_ifaddr_lock and in6_ifaddr_lock to rmlock.

Both are used to protect access to IP addresses lists and they can be
acquired for reading several times per packet. To reduce lock contention
it is better to use rmlock here.

Reviewed by: gnn (previous version)
Obtained from: Yandex LLC
Sponsored by: Yandex LLC
Differential Revision: https://reviews.freebsd.org/D3149

Extend fixes made in r278103 and r38754 by copying the complete packet
header and not only partial flags and fields. Firewalls can attach
classification tags to the outgoing mbufs which should be copied to
all the new fragments. Else only the first fragment will be let
through by the firewall. This can easily be tested by sending a large
ping packet through a firewall. It was also discovered that VLAN
related flags and fields should be copied for packets traversing
through VLANs. This is all handled by "m_dup_pkthdr()".

Regarding the MAC policy check in ip_fragment(), the tag provided by
the originating mbuf is copied instead of using the default one
provided by m_gethdr().

Tested by: Karim Fodil-Lemelin <fodillemlinkarim at gmail.com>
MFC after: 2 weeks
Sponsored by: Mellanox Technologies
PR: 7802

o Use new function ip_fillid() in all places throughout the kernel,
where we want to create a new IP datagram.
o Add support for RFC6864, which allows to set IP ID for atomic IP
datagrams to any value, to improve performance. The behaviour is
controlled by net.inet.ip.rfc6864 sysctl knob, which is enabled by
default.
o In case if we generate IP ID, use counter(9) to improve performance.
o Gather all code related to IP ID into ip_id.c.

Differential Revision: https://reviews.freebsd.org/D2177
Reviewed by: adrian, cy, rpaulo
Tested by: Emeric POUPON <emeric.poupon stormshield.eu>
Sponsored by: Netflix
Sponsored by: Nginx, Inc.
Relnotes: yes

On multi CPU systems, we may emit successive packets with the same id.
Fix the race by using an atomic operation.

Differential Revision: https://reviews.freebsd.org/D2141
Obtained from: emeric.poupon@stormshield.eu
MFC after: 1 week
Sponsored by: Stormshield

Fix a special case in ip_fragment() to produce a more sensible chain
of packets. When the data payload length excluding any headers, of an
outgoing IPv4 packet exceeds PAGE_SIZE bytes, a special case in
ip_fragment() can kick in to optimise the outgoing payload(s). The
code which was added in r98849 as part of zero copy socket support
assumes that the beginning of any MTU sized payload is aligned to
where a MBUF's "m_data" pointer points. This is not always the case
and can sometimes cause large IPv4 packets, as part of ping replies,
to be split more than needed.

Instead of iterating the MBUFs to figure out how much data is in the
current chain, use the value already in the "m_pkthdr.len" field of
the first MBUF in the chain.

Reviewed by: ken @
Differential Revision: https://reviews.freebsd.org/D1893
MFC after: 2 weeks
Sponsored by: Mellanox Technologies

The flowid and hashtype should be copied from the originating packet
when fragmenting IP packets to preserve the order of the packets in a
stream. Else the resulting fragments can be sent out of order when the
hardware supports multiple transmit rings.

Reviewed by: glebius @
MFC after: 1 week
Sponsored by: Mellanox Technologies

Refactor / restructure the RSS code into generic, IPv4 and IPv6 specific
bits.

The motivation here is to eventually teach netisr and potentially
other networking subsystems a bit more about how RSS work queues / buckets
are configured so things have a hope of auto-configuring in the future.

* net/rss_config.[ch] takes care of the generic bits for doing
configuration, hash function selection, etc;
* topelitz.[ch] is now in net/ rather than netinet/;
* (and would be in libkern if it didn't directly include RSS_KEYSIZE;
that's a later thing to fix up.)
* netinet/in_rss.[ch] now just contains the IPv4 specific methods;
* and netinet/in6_rss.[ch] now just contains the IPv6 specific methods.

This should have no functional impact on anyone currently using
the RSS support.

Differential Revision: D1383
Reviewed by: gnn, jfv (intel driver bits)

Remove flag/flags argument from the following functions:
ipsec_getpolicybyaddr()
ipsec4_checkpolicy()
ip_ipsec_output()
ip6_ipsec_output()

The only flag used here was IP_FORWARDING.

Obtained from: Yandex LLC
Sponsored by: Yandex LLC

Start process of removing the use of the deprecated "M_FLOWID" flag
from the FreeBSD network code. The flag is still kept around in the
"sys/mbuf.h" header file, but does no longer have any users. Instead
the "m_pkthdr.rsstype" field in the mbuf structure is now used to
decide the meaning of the "m_pkthdr.flowid" field. To modify the
"m_pkthdr.rsstype" field please use the existing "M_HASHTYPE_XXX"
macros as defined in the "sys/mbuf.h" header file.

This patch introduces new behaviour in the transmit direction.
Previously network drivers checked if "M_FLOWID" was set in "m_flags"
before using the "m_pkthdr.flowid" field. This check has now now been
replaced by checking if "M_HASHTYPE_GET(m)" is different from
"M_HASHTYPE_NONE". In the future more hashtypes will be added, for
example hashtypes for hardware dedicated flows.

"M_HASHTYPE_OPAQUE" indicates that the "m_pkthdr.flowid" value is
valid and has no particular type. This change removes the need for an
"if" statement in TCP transmit code checking for the presence of a
valid flowid value. The "if" statement mentioned above is now a direct
variable assignment which is then later checked by the respective
network drivers like before.

Additional notes:
- The SCTP code changes will be committed as a separate patch.
- Removal of the "M_FLOWID" flag will also be done separately.
- The FreeBSD version has been bumped.

MFC after: 1 month
Sponsored by: Mellanox Technologies

Finish r274175: do control plane MTU tracking.

Update route MTU in case of ifnet MTU change.
Add new RTF_FIXEDMTU to track explicitly specified MTU.

Old behavior:
ifconfig em0 mtu 1500->9000 -> all routes traversing em0 do not change MTU.
User has to manually update all routes.
ifconfig em0 mtu 9000->1500 -> all routes traversing em0 do not change MTU.
However, if ip[6]_output finds route with rt_mtu > interface mtu, rt_mtu
gets updated.

New behavior:
ifconfig em0 mtu 1500->9000 -> all interface routes in all fibs gets updated
with new MTU unless RTF_FIXEDMTU flag set on them.
ifconfig em0 mtu 9000->1500 -> all routes in all fibs gets updated with new
MTU unless RTF_FIXEDMTU flag set on them AND rt_mtu is less than ifp mtu.

route add ... -mtu XXX automatically sets RTF_FIXEDMTU flag.
route change .. -mtu 0 automatically removes RTF_FIXEDMTU flag.

PR: 194238
MFC after: 1 month
CR: D1125

Renove faith(4) and faithd(8) from base. It looks like industry
have chosen different (and more traditional) stateless/statuful
NAT64 as translation mechanism. Last non-trivial commits to both
faith(4) and faithd(8) happened more than 12 years ago, so I assume
it is time to drop RFC3142 in FreeBSD.

No objections from: net@

Convert netinet6/ to use new routing API.

* Remove &ifpp from ip6_output() in favor of ri->ri_nh_info
* Provide different wrappers to in6_selectsrc:
Currently it is used by 2 differenct type of customers:
- socket-based one, which all are unsure about provided
address scope and
- in-kernel ones (ND code mostly), which don't have
any sockets, options, crededentials, etc.
So, we provide two different wrappers to in6_selectsrc()
returning select source.
* Make different versions of selectroute():
Currenly selectroute() is used in two scenarios:
- SAS, via in6_selecsrc() -> in6_selectif() -> selectroute()
- output, via in6_output -> wrapper -> selectroute()
Provide different versions for each customer:
- fib6_lookup_nh_basic()-based in6_selectif() which is
capable of returning interface only, without MTU/NHOP/L2
calculations
- full-blown fib6_selectroute() with cached route/multipath/
MTU/L2
* Stop using routing table for link-local address lookups
* Add in6_ifawithifp_lla() to make for-us check faster for link-local
* Add in6_splitscope / in6_setllascope for faster embed/deembed scopes

* Increase nh_flags to be u16 thus reducing nhop payload to be 48 bytes
* Use NHF_ namespace for all nhop flags
* Rename nhop_data -> nhop_prepend
* Rename fib4_lookup_nh_extended -> fib4_lookup_nh_ext
* Add "flags" argument to fib4_lookup_nh_ext() to specify whether we want
returned nh_ext structure to be refcounted or not.

Rename ip_sendmbuf to fib4_sendmbuf() and move it to rt_nhops api.
Convert IPv4 SAS to use new routing api.

Switch IPv4 output path to use new routing api.

The goals of the new API is to provide consumers with minimal
needed information, but as fast as possible. So we provide
full nexthop info copied into alighed on-cache structure
instead of rte/ia pointers, their refcounts and locks.
This does not provide solution for protecting from egress
ifp destruction, but does not make it any worse.

Current changes:

nhops:
Add fib4_lookup_prepend() function which stores either full
L2+L3 prepend info (e.g. MAC header in case of plain IPv4) or
L3 info with NH_FLAGS_L2_INCOMPLETE flag indicating that no valid L2
info exists and we have to take "slow" path.

ip_output:
Currently ip[ 46]_output consumers use 'struct route' for
the following purposes:
1) double lookup avoidance(route caching)
2) plain route caching
3) get path MTU to be able to notify source.
The former pattern is mostly used by various tunnels
(gif, gre, stf). (Actually, gre is the only remaining,
others were already converted. Their locking model did
not scale good enogh to benefit from such caching, so
we have (temporarily) removed it without any performance
loss).
Plain route caching used by SCTP is simply wrong and should be removed.
Temporary break it for now just to be able to compile.
Optimize path mtu reporting by providing it in new 'route_info' stucture.

Minimize games with @ia locking/refcounting for route lookup:
add special nhop[46]_extended structure to store more route attributes.
Pointer to given structure can be passed to fib4_lookup_prepend() to indicate
we want this info (we actually needs it for UDP and raw IP).

ether_output:
Provide light-weight ether_output2() call to deal with
transmitting L2 frame (e.g. properly handle broadcast/simloop/bridge/
other L2 hooks before actually transmitting frame by if_transmit()).
Add a hack based on new RT_NHOP ro_flag to distinguish which version should
we call. Better way is probably to add a new "if_output_frame" driver
callbacks.

Next steps:
* Convert ip_fastfwd part
* Implement auto-growing array for per-radix nexthops
* Implement LLE tracking for nexthop calculations to be able to
immediately provide all necessary info in single route lookup
for gateway routes
* Switch radix locking scheme to runtime/cfg lock
* Implement multipath support for rtsock
* Implement "tracked nexthops" for tunnels (e.g. _proper_
nexthop caching)
* Add IPv6 support for remaining parts (postponed not to
interfere with user/ae/inet6 branch)
* Consider adding "if_output_frame" driver call to
ease logical frame pushing.

When deciding whether to call m_pullup() even though there is adequate
data in an mbuf, use M_WRITABLE() instead of a direct test of M_EXT;
the latter both unnecessarily exposes mbuf-allocator internals in the
protocol stack and is also insufficient to catch all cases of
non-writability.

(NB: m_pullup() does not actually guarantee that a writable mbuf is
returned, so further refinement of all of these code paths continues to
be required.)

Reviewed by: bz
MFC after: 3 days
Sponsored by: EMC / Isilon Storage Division
Differential Revision: https://reviews.freebsd.org/D900

Add an additional routing table lookup when m->m_pkthdr.fibnum is changed
at a PFIL hook in ip{,6}_output(). IPFW setfib rule did not perform
a routing table lookup when the destination address was not changed.

CR: D805

Remove disabled code, that is very unlikely to be ever enabled again,
as well as the comment that explains why is it disabled.

Fix source address selection on unbound sockets in the presence of multiple
fibs. Use the mbuf's or the socket's fib instead of RT_ALL_FIBS. Fixes PR
187553. Also fixes netperf's UDP_STREAM test on a nondefault fib.

sys/netinet/ip_output.c
In ip_output, lookup the source address using the mbuf's fib instead
of RT_ALL_FIBS.

sys/netinet/in_pcb.c
in in_pcbladdr, lookup the source address using the socket's fib,
because we don't seem to have the mbuf fib. They should be the same,
though.

tests/sys/net/fibs_test.sh
Clear the expected failure on udp_dontroute.

PR: 187553
CR: https://reviews.freebsd.org/D772
MFC after: 3 weeks
Sponsored by: Spectra Logic

Revisions 264905 and 266860 added a "int fib" argument to ifa_ifwithnet and
ifa_ifwithdstaddr. For the sake of backwards compatibility, the new
arguments were added to new functions named ifa_ifwithnet_fib and
ifa_ifwithdstaddr_fib, while the old functions became wrappers around the
new ones that passed RT_ALL_FIBS for the fib argument. However, the
backwards compatibility is not desired for FreeBSD 11, because there are
numerous other incompatible changes to the ifnet(9) API. We therefore
decided to remove it from head but leave it in place for stable/9 and
stable/10. In addition, this commit adds the fib argument to
ifa_ifwithbroadaddr for consistency's sake.

sys/sys/param.h
Increment __FreeBSD_version

sys/net/if.c
sys/net/if_var.h
sys/net/route.c
Add fibnum argument to ifa_ifwithbroadaddr, and remove the _fib
versions of ifa_ifwithdstaddr, ifa_ifwithnet, and ifa_ifwithroute.

sys/net/route.c
sys/net/rtsock.c
sys/netinet/in_pcb.c
sys/netinet/ip_options.c
sys/netinet/ip_output.c
sys/netinet6/nd6.c
Fixup calls of modified functions.

share/man/man9/ifnet.9
Document changed API.

CR: https://reviews.freebsd.org/D458
MFC after: Never
Sponsored by: Spectra Logic

Add support for receiving and setting flowtype, flowid and RSS bucket
information as part of recvmsg().

This is primarily used for debugging/verification of the various
processing paths in the IP, PCB and driver layers.

Unfortunately the current implementation of the control message path
results in a ~10% or so drop in UDP frame throughput when it's used.

Differential Revision: https://reviews.freebsd.org/D527
Reviewed by: grehan

Add a flag to ip_output() - IP_NODEFAULTFLOWID - which prevents it from
overriding an existing flowid/flowtype field in the outbound mbuf with
the inp_flowid/inp_flowtype details.

The upcoming RSS UDP support calculates a valid RSS value for outbound
mbufs and since it may change per send, it doesn't cache it in the inpcb.
So overriding it here would be wrong.

Differential Revision: https://reviews.freebsd.org/D527
Reviewed by: grehan

Clean up unused CSUM_FRAGMENT.

Sponsored by: Nginx, Inc.

Implement the first stage of multi-bind listen sockets and RSS socket
awareness.

* Introduce IP_BINDMULTI - indicating that it's okay to bind multiple
sockets on the same bind details.

Although the PCB code has been taught about this (see below) this patch
doesn't introduce the rest of the PCB changes necessary to distribute
lookups among multiple PCB entries in the global wildcard table.

* Introduce IP_RSS_LISTEN_BUCKET - placing an listen socket into the
given RSS bucket (and thus a single PCBGROUP hash.)

* Modify the PCB add path to be aware of IP_BINDMULTI:
+ Only allow further PCB entries to be added if the owner credentials
and IP_BINDMULTI has been specified. Ie, only allow further
IP_BINDMULTI sockets to appear if the first bind() was IP_BINDMULTI.

* Teach the PCBGROUP code about IP_RSS_LISTE_BUCKET marked PCB entries.
Instead of using the wildcard logic and hashing, these sockets are
simply placed into the PCBGROUP and _not_ in the wildcard hash.

* When doing a PCBGROUP lookup, also do a wildcard match as well.
This allows for an RSS bucket PCB entry to appear in a PCBGROUP
rather than having to exist in the wildcard list.

Tested:

* TCP IPv4 server testing with igb(4)
* TCP IPv4 server testing with ix(4)

TODO:

* The pcbgroup lookup code duplicated the wildcard and wildcard-PCB
logic. This could be refactored into a single function.

* This doesn't yet work for IPv6 (The PCBGROUP code in netinet6/ doesn't
yet know about this); nor does it yet fully work for UDP.

In several cases in ip_output() we obtain reference on ifa. Do not
leak it.

Together with: asomers, np
Sponsored by: Nginx, Inc.

Remove old reference to IP_RSSCPUID.

Submitted by: Eggert, Lars <lars@netapp.com>

Add missing variable declarations when using RSS.

Reported by: bryanv@

Retire IP_RSSCPUID ; the right thing to do is query the RSS bucket;
map the bucket to an RSS queue, then map the queue to a CPU ID.
This way the bucket->queue and queue->CPU mapping can change
over time.

Introduce IP_RSSBUCKETID - which instead looks up the RSS bucket.
User applications can then map the RSS bucket to a CPU.

Fix unintended KBI change from r264905. Add _fib versions of
ifa_ifwithnet() and ifa_ifwithdstaddr() The legacy functions will call the
_fib() versions with RT_ALL_FIBS, preserving legacy behavior.

sys/net/if_var.h
sys/net/if.c
Add legacy-compatible functions as described above. Ensure legacy
behavior when RT_ALL_FIBS is passed as fibnum.

sys/netinet/in_pcb.c
sys/netinet/ip_output.c
sys/netinet/ip_options.c
sys/net/route.c
sys/net/rtsock.c
sys/netinet6/nd6.c
Call with _fib() functions if we must use a specific fib, or the
legacy functions otherwise.

tests/sys/netinet/fibs_test.sh
tests/sys/netinet/udp_dontroute.c
Improve the udp_dontroute test. The bug that this test exercises is
that ifa_ifwithnet() will return the wrong address, if multiple
interfaces have addresses on the same subnet but with different
fibs. The previous version of the test only considered one possible
failure mode: that ifa_ifwithnet_fib() might fail to find any
suitable address at all. The new version also checks whether
ifa_ifwithnet_fib() finds the correct address by checking where the
ARP request goes.

Reported by: bz, hrs
Reviewed by: hrs
MFC after: 1 week
X-MFC-with: 264905
Sponsored by: Spectra Logic

* When copying the flowid from inp -> outbound mbuf, also assign the
hashtype to to the outbound mbuf as well as the flowid.

* Add in socket options to fetch the hashid, the hashtype and RSS CPU
ID for a given socket.

Use KASSERTs as suggested by glebius@

MFC after: 3 days
X-MFC with: 265691

For some UDP packets (for example with 200 byte payload) and IP options,
the IP header and the UDP header are not in the same mbuf.
Add code to in_delayed_cksum() to deal with this case.

MFC after: 3 days

Fix subnet and default routes on different FIBs on the same subnet.

These two bugs are closely related. The root cause is that ifa_ifwithnet
does not consider FIBs when searching for an interface address.

sys/net/if_var.h
sys/net/if.c
Add a fib argument to ifa_ifwithnet and ifa_ifwithdstadddr. Those
functions will only return an address whose interface fib equals the
argument.

sys/net/route.c
Update calls to ifa_ifwithnet and ifa_ifwithdstaddr with fib
arguments.

sys/netinet/in.c
Update in_addprefix to consider the interface fib when adding
prefixes. This will prevent it from not adding a subnet route when
one already exists on a different fib.

sys/net/rtsock.c
sys/netinet/in_pcb.c
sys/netinet/ip_output.c
sys/netinet/ip_options.c
sys/netinet6/nd6.c
Add RT_DEFAULT_FIB arguments to ifa_ifwithdstaddr and ifa_ifwithnet.
In some cases it there wasn't a clear specific fib number to use.
In others, I was unable to test those functions so I chose
RT_DEFAULT_FIB to minimize divergence from current behavior. I will
fix some of the latter changes along with PR kern/187553.

tests/sys/netinet/fibs_test.sh
tests/sys/netinet/udp_dontroute.c
tests/sys/netinet/Makefile
Revert r263738. The udp_dontroute test was right all along.
However, bugs kern/187550 and kern/187553 cancelled each other out
when it came to this test. Because of kern/187553, ifa_ifwithnet
searched the default fib instead of the requested one, but because
of kern/187550, there was an applicable subnet route on the default
fib. The new test added in r263738 doesn't work right, however. I
can verify with dtrace that ifa_ifwithnet returned the wrong address
before I applied this commit, but route(8) miraculously found the
correct interface to use anyway. I don't know how.

Clear expected failure messages for kern/187550 and kern/187552.

PR: kern/187550
PR: kern/187552
Reviewed by: melifaro
MFC after: 3 weeks
Sponsored by: Spectra Logic

- Remove rt_metrics_lite and simply put its members into rtentry.
- Use counter(9) for rt_pksent (former rt_rmx.rmx_pksent). This
removes another cache trashing ++ from packet forwarding path.
- Create zini/fini methods for the rtentry UMA zone. Via initialize
mutex and counter in them.
- Fix reporting of rmx_pksent to routing socket.
- Fix netstat(1) to report "Use" both in kvm(3) and sysctl(3) mode.

The change is mostly targeted for stable/10 merge. For head,
rt_pksent is expected to just disappear.

Discussed with: melifaro
Sponsored by: Netflix
Sponsored by: Nginx, Inc.

Remove ifa_ref()/ifa_free(), which are atomic(9), from ip_output().

The ifaddr is already referenced by the rtentry, and we are holding
reference on the rtentry throughout the function execution.

Sponsored by: Netflix
Sponsored by: Nginx, Inc.

o Remove at compile time the HASH_ALL code, that was never
tested and is unfinished. However, I've tested my version,
it works okay. As before it is unfinished: timeout aren't
driven by TCP session state. To enable the HASH_ALL mode,
one needs in kernel config:

options FLOWTABLE_HASH_ALL

o Reduce the alignment on flentry to 64 bytes. Without
the FLOWTABLE_HASH_ALL option, twice less memory would
be consumed by flows.
o API to ip_output()/ip6_output() got even more thin: 1 liner.
o Remove unused unions. Simply use fle->f_key[].
o Merge all IPv4 code into flowtable_lookup_ipv4(), and do same
flowtable_lookup_ipv6(). Stop copying data to on stack
sockaddr structures, simply use key[] on stack.
o Move code from flowtable_lookup_common() that actually works
on insertion into flowtable_insert().

Sponsored by: Netflix
Sponsored by: Nginx, Inc.

o Revamp API between flowtable and netinet, netinet6.
- ip_output() and ip_output6() simply call flowtable_lookup(),
passing mbuf and address family. That's the only code under
#ifdef FLOWTABLE in the protocols code now.
o Revamp statistics gathering and export.
- Remove hand made pcpu stats, and utilize counter(9).
- Snapshot of statistics is available via 'netstat -rs'.
- All sysctls are moved into net.flowtable namespace, since
spreading them over net.inet isn't correct.
o Properly separate at compile time INET and INET6 parts.
o General cleanup.
- Remove chain of multiple flowtables. We simply have one for
IPv4 and one for IPv6.
- Flowtables are allocated in flowtable.c, symbols are static.
- With proper argument to SYSINIT() we no longer need flowtable_ready.
- Hash salt doesn't need to be per-VNET.
- Removed rudimentary debugging, which use quite useless in dtrace era.

The runtime behavior of flowtable shouldn't be changed by this commit.

Sponsored by: Netflix
Sponsored by: Nginx, Inc.

Cleanup comments and whitespace. No functional changes.

Fix ipfw fwd for IPv4 traffic broken by r249894.

Problem case:
Original lookup returns route with GW set, so gw points to
rte->rt_gateway.
After that we're changing dst and performing lookup another time.
Since fwd host is most probably directly reachable, resulting
rte does not contain rt_gateway, so gw is not set. Finally, we
end with packet transmitted to proper interface but wrong
link-layer address.

Found by: lstewart
Discussed with: ae,lstewart
MFC after: 2 weeks
Sponsored by: Yandex LLC

Fix regression from r249894. Now we pass "gw" as argument to if_output
method, thus for multicast case we need it to point at "dst".

PR: 185395
Submitted by: ae

Disable the now unpredicably bogus check for whether we have
eneough queue space before queuing a bunch of IP fragments.

As the comment in the committed change says, in the post-if_transmit(),
post-SMP, post-preemption world, there's just too much overlapping
concurrent code paths and different approaches to driver transmit
queue management to have this code even remotely be effective.

The only specific place it could be useful is if ALTQ is enabled
but again it doesn't at all promise that all the fragments will be
transmitted anyway.

The main reason for committing this change is to disable a parallel
place where the drops counter is incremented. This is a side effect
of an upcoming change to ixgbe/cxgbe to handle the queue drops
counter slightly better.

Sponsored by: Netflix, Inc.

- For kernel compiled only with KDTRACE_HOOKS and not any lock debugging
option, unbreak the lock tracing release semantic by embedding
calls to LOCKSTAT_PROFILE_RELEASE_LOCK() direclty in the inlined
version of the releasing functions for mutex, rwlock and sxlock.
Failing to do so skips the lockstat_probe_func invokation for
unlocking.
- As part of the LOCKSTAT support is inlined in mutex operation, for
kernel compiled without lock debugging options, potentially every
consumer must be compiled including opt_kdtrace.h.
Fix this by moving KDTRACE_HOOKS into opt_global.h and remove the
dependency by opt_kdtrace.h for all files, as now only KDTRACE_FRAMES
is linked there and it is only used as a compile-time stub [0].

[0] immediately shows some new bug as DTRACE-derived support for debug
in sfxge is broken and it was never really tested. As it was not
including correctly opt_kdtrace.h before it was never enabled so it
was kept broken for a while. Fix this by using a protection stub,
leaving sfxge driver authors the responsibility for fixing it
appropriately [1].

Sponsored by: EMC / Isilon storage division
Discussed with: rstone
[0] Reported by: rstone
[1] Discussed with: philip

The r48589 promised to remove implicit inclusion of if_var.h soon. Prepare
to this event, adding if_var.h to files that do need it. Also, include
all includes that now are included due to implicit pollution via if_var.h

Sponsored by: Netflix
Sponsored by: Nginx, Inc.

- Utilize counter(9) to accumulate statistics on interface addresses. Add
four counters to struct ifaddr. This kills '+=' on a variables shared
between processors for every packet.
- Nuke struct if_data from struct ifaddr.
- In ip_input() do not put a reference on ifaddr, instead update statistics
right now in place and do IN_IFADDR_RUNLOCK(). These removes atomic(9)
for every packet. [1]
- To properly support NET_RT_IFLISTL sysctl used by getifaddrs(3), in
rtsock.c fill if_data fields using counter_u64_fetch().
- Accidentially fix bug in COMPAT_32 version of NET_RT_IFLISTL, which
took if_data not from the ifaddr, but from ifaddr's ifnet. [2]

Submitted by: melifaro [1], pluknet[2]
Sponsored by: Netflix
Sponsored by: Nginx, Inc.

Implement the ip, tcp, and udp DTrace providers. The probe definitions use
dynamic translation so that their arguments match the definitions for
these providers in Solaris and illumos. Thus, existing scripts for these
providers should work unmodified on FreeBSD.

Tested by: gnn, hiren
MFC after: 1 month

Add m_clrprotoflags() to clear protocol specific mbuf flags at up and
downwards layer crossings.

Consistently use it within IP, IPv6 and ethernet protocols.

Discussed with: trociny, glebius

Remove unused M_FRAG, M_FIRSTFRAG and M_LASTFRAG tagging from ip_fragment().
There wasn't any real driver (and hardware) support for it. Modern hardware
does full fragmentation/segmentation offload instead.

In r227207, to fix the issue with possible NULL inp_socket pointer
dereferencing, when checking for SO_REUSEPORT option (and SO_REUSEADDR
for multicast), INP_REUSEPORT flag was introduced to cache the socket
option. It was decided then that one flag would be enough to cache
both SO_REUSEPORT and SO_REUSEADDR: when processing SO_REUSEADDR
setsockopt(2), it was checked if it was called for a multicast address
and INP_REUSEPORT was set accordingly.

Unfortunately that approach does not work when setsockopt(2) is called
before binding to a multicast address: the multicast check fails and
INP_REUSEPORT is not set.

Fix this by adding INP_REUSEADDR flag to unconditionally cache
SO_REUSEADDR.

PR: 179901
Submitted by: Michael Gmelin freebsd grem.de (initial version)
Reviewed by: rwatson
MFC after: 1 week

Add const qualifier to the dst parameter of the ifnet if_output method.

Introduce a pointer to const variable gw, which points either at the
same place as dst, or to the sockaddr in the routing table.

The const constraint of gw makes us safe from modifing routing table
accidentially. And "onstantness" of dst allows us to remove several
bandaids, when we switched it back at &ro->ro_dst, now it always
points there.

Reviewed by: rrs

This fixes the issue with the "randomly changing" default
route. What it was is there are two places in ip_output.c
where we do a goto again. One place was fine, it
copies out the new address and then resets dst = ro->rt_dst;
But the other place does *not* do that, which means earlier
when we found the gateway, we have dst pointing there
aka dst = ro->rt_gateway is done.. then we do a
goto again.. bam now we clobber the default route.

The fix is just to move the again so we are always
doing dst = &ro->rt_dst; in the again loop.

PR: 174749,157796
MFC after: 1 week

Use m_get/m_gethdr instead of compat macros.

Sponsored by: Nginx, Inc.

Mechanically substitute flags from historic mbuf allocator with
malloc(9) flags within sys.

Exceptions:

- sys/contrib not touched
- sys/mbuf.h edited manually

Remove unused and unnecessary CSUM_IP_FRAGS checksumming capability.
Checksumming the IP header of fragments is no different from doing
normal IP headers.

Discussed with: yongari
MFC after: 1 week

Remove the recently added sysctl variable net.pfil.forward.
Instead, add protocol specific mbuf flags M_IP_NEXTHOP and
M_IP6_NEXTHOP. Use them to indicate that the mbuf's chain
contains the PACKET_TAG_IPFORWARD tag. And do a tag lookup
only when this flag is set.

Suggested by: andre

o Remove last argument to ip_fragment(), and obtain all needed information
on checksums directly from mbuf flags. This simplifies code.
o Clear CSUM_IP from the mbuf in ip_fragment() if we did checksums in
hardware. Some driver may not announce CSUM_IP in theur if_hwassist,
although try to do checksums if CSUM_IP set on mbuf. Example is em(4).
o While here, consistently use CSUM_IP instead of its alias CSUM_DELAY_IP.
After this change CSUM_DELAY_IP vanishes from the stack.

Submitted by: Sebastian Kuzminsky <seb lineratesystems.com>

Remove the IPFIREWALL_FORWARD kernel option and make possible to turn
on the related functionality in the runtime via the sysctl variable
net.pfil.forward. It is turned off by default.

Sponsored by: Yandex LLC
Discussed with: net@
MFC after: 2 weeks

Switch the entire IPv4 stack to keep the IP packet header
in network byte order. Any host byte order processing is
done in local variables and host byte order values are
never[1] written to a packet.

After this change a packet processed by the stack isn't
modified at all[2] except for TTL.

After this change a network stack hacker doesn't need to
scratch his head trying to figure out what is the byte order
at the given place in the stack.

[1] One exception still remains. The raw sockets convert host
byte order before pass a packet to an application. Probably
this would remain for ages for compatibility.

[2] The ip_input() still subtructs header len from ip->ip_len,
but this is planned to be fixed soon.

Reviewed by: luigi, Maxim Dounin <mdounin mdounin.ru>
Tested by: ray, Olivier Cochard-Labbe <olivier cochard.me>

Fix a miss from r241344: in ip_mloopback() we need to go to
net byte order prior to calling in_delayed_cksum().

Reported by: Olivier Cochard-Labbe <olivier cochard.me>

After r241245 it appeared that in_delayed_cksum(), which still expects
host byte order, was sometimes called with net byte order. Since we are
moving towards net byte order throughout the stack, the function was
converted to expect net byte order, and its consumers fixed appropriately:
- ip_output(), ipfilter(4) not changed, since already call
in_delayed_cksum() with header in net byte order.
- divert(4), ng_nat(4), ipfw_nat(4) now don't need to swap byte order
there and back.
- mrouting code and IPv6 ipsec now need to switch byte order there and
back, but I hope, this is temporary solution.
- In ipsec(4) shifted switch to net byte order prior to in_delayed_cksum().
- pf_route() catches up on r241245 changes to ip_output().

A step in resolving mess with byte ordering for AF_INET. After this change:

- All packets in NETISR_IP queue are in net byte order.
- ip_input() is entered in net byte order and converts packet
to host byte order right _after_ processing pfil(9) hooks.
- ip_output() is entered in host byte order and converts packet
to net byte order right _before_ processing pfil(9) hooks.
- ip_fragment() accepts and emits packet in net byte order.
- ip_forward(), ip_mloopback() use host byte order (untouched actually).
- ip_fastforward() no longer modifies packet at all (except ip_ttl).
- Swapping of byte order there and back removed from the following modules:
pf(4), ipfw(4), enc(4), if_bridge(4).
- Swapping of byte order added to ipfilter(4), based on __FreeBSD_version
- __FreeBSD_version bumped.
- pfil(9) manual page updated.

Reviewed by: ray, luigi, eri, melifaro
Tested by: glebius (LE), ray (BE)

Plug a reference leak: before doing 'goto again' we need to unref
ia->ia_ifa if there is any.

Submitted by: Andrey Zonov <andrey zonov.org>

When ip_output()/ip6_output() is supplied a struct route *ro argument,
it skips FLOWTABLE lookup. However, the non-NULL ro has dual meaning
here: it may be supplied to provide route, and it may be supplied to
store and return to caller the route that ip_output()/ip6_output()
finds. In the latter case skipping FLOWTABLE lookup is pessimisation.

The difference between struct route filled by FLOWTABLE and filled
by rtalloc() family is that the former doesn't hold a reference on
its rtentry. Reference is hold by flow entry, and it is about to
be released in future. Thus, route filled by FLOWTABLE shouldn't
be passed to RTFREE() macro.

- Introduce new flag for struct route/route_in6, that marks route
not holding a reference on rtentry.
- Introduce new macro RO_RTFREE() that cleans up a struct route
depending on its kind.
- All callers to ip_output()/ip6_output() that do supply non-NULL
but empty route should use RO_RTFREE() to free results of
lookup.
- ip_output()/ip6_output() now do FLOWTABLE lookup always when
ro->ro_rt == NULL.

Tested by: tuexen (SCTP part)

Add a IP_RECVTOS socket option to receive for received UDP/IPv4
packets a cmsg of type IP_RECVTOS which contains the TOS byte.
Much like IP_RECVTTL does for TTL. This allows to implement a
protocol on top of UDP and implementing ECN.

MFC after: 3 days

Cache SO_REUSEPORT socket option in inpcb-layer in order to avoid
inp_socket->so_options dereference when we may not acquire the lock on
the inpcb.

This fixes the crash due to NULL pointer dereference in
in_pcbbind_setup() when inp_socket->so_options in a pcb returned by
in_pcblookup_local() was checked.

Reported by: dave jones <s.dave.jones@gmail.com>, Arnaud Lacombe <lacombar@gmail.com>
Suggested by: rwatson
Glanced by: rwatson
Tested by: dave jones <s.dave.jones@gmail.com>

The mbuf_frag_size always was and is file local and not queried from base
user space tools via kvm. Mark it static.

MFC after: 3 days

Try to catch a possible divide-by-zero as early as possible if "mtu" is 0
(also test for negative MTUs if checking it anyway).
An MTU of 0 is arguably a bug elsewhere, but this at least gives us some
more debugging hints.

Sponsored by: ISPsystem (Early 2010)
MFC after: 1 week

A new jail(8) with a configuration file, to replace the work currently done
by /etc/rc.d/jail.

IP_BINDANY is not correctly handled in getsockopt() case.
Fix it by specifying the correct bits.

Sponsored by: Sandvine Incorporated
Reviewed by: bz, emaste, rstone
Obtained from: Sandvine Incorporated
MFC after: 10 days

MFC r208553

This patch fixes the problem where proxy ARP entries cannot be added
over the if_ng interface.

Approved by: re (bz)

This patch fixes the problem where proxy ARP entries cannot be added
over the if_ng interface.

MFC after: 3 days

MFC of 2 items to fix the csum for v6 issue:
Revision 205075 and 205104:

---------205075----------
With the recent change of the sctp checksum to support offload,
no delayed checksum was added to the ip6 output code. This
causes cards that do not support SCTP checksum offload to
have SCTP packets that are IPv6 NOT have the sctp checksum
performed. Thus you could not communicate with a peer. This
adds the missing bits to make the checksum happen for these cards.
-------------------------
---------205104----------
The proper fix for the delayed SCTP checksum is to
have the delayed function take an argument as to the offset
to the SCTP header. This allows it to work for V4 and V6.
This of course means changing all callers of the function
to either pass the header len, if they have it, or create
it (ip_hl << 2 or sizeof(ip6_hdr)).
-------------------------
PR: 144529

MFC 204902

One of the advantages of enabling ECMP (a.k.a RADIX_MPATH) is to
allow for connection load balancing across interfaces. Currently
the address alias handling method is colliding with the ECMP code.
For example, when two interfaces are configured on the same prefix,
only one prefix route is installed. So connection load balancing
among the available interfaces is not possible.

The other advantage of ECMP is for failover. The issue with the
current code, is that the interface link-state is not reflected
in the route entry. For example, if there are two interfaces on
the same prefix, the cable on one interface is unplugged, new and
existing connections should switch over to the other interface.
This is not done today and packets go into a black hole.

Also, there is a small bug in the kernel where deleting ECMP routes
in the userland will always return an error even though the command
is successfully executed.

MFC 201131

introduce a local variable rte acting as a cache of ro->ro_rt
within ip_output, achieving (in random order of importance):
- a reduction of the number of 'r's in the source code;
- improved legibility;
- a reduction of 64 bytes in the .text

MFC 205066, 205069, 205093, 205097, 205488:

r205066:

Log:
- restructure flowtable to support ipv6
- add a name argument to flowtable_alloc for printing with ddb commands
- extend ddb commands to print destination address or 4-tuples
- don't parse ports in ulp header if FL_HASH_ALL is not passed
- add kern_flowtable_insert to enable more generic use of flowtable
(e.g. system calls for adding entries)
- don't hash loopback addresses
- cleanup whitespace
- keep statistics per-cpu for per-cpu flowtables to avoid cache line contention
- add sysctls to accumulate stats and report aggregate

r205069:
Log:
fix stats reporting sysctl

r205093:
Log:
re-update copyright to 2010
pointed out by danfe@

r205097:

Log:
flowtable_get_hashkey is only used by a DDB function - move under #ifdef DDB

pointed out by jkim@

r205488:

Log:
- boot-time size the ipv4 flowtable and the maximum number of flows
- increase flow cleaning frequency and decrease flow caching time
when near the flow limit
- stop allocating new flows when within 3% of maxflows don't start
allocating again until below 12.5%

The proper fix for the delayed SCTP checksum is to
have the delayed function take an argument as to the offset
to the SCTP header. This allows it to work for V4 and V6.
This of course means changing all callers of the function
to either pass the header len, if they have it, or create
it (ip_hl << 2 or sizeof(ip6_hdr)).
PR: 144529
MFC after: 2 weeks

- restructure flowtable to support ipv6
- add a name argument to flowtable_alloc for printing with ddb commands
- extend ddb commands to print destination address or 4-tuples
- don't parse ports in ulp header if FL_HASH_ALL is not passed
- add kern_flowtable_insert to enable more generic use of flowtable
(e.g. system calls for adding entries)
- don't hash loopback addresses
- cleanup whitespace
- keep statistics per-cpu for per-cpu flowtables to avoid cache line contention
- add sysctls to accumulate stats and report aggregate

MFC after: 7 days

One of the advantages of enabling ECMP (a.k.a RADIX_MPATH) is to
allow for connection load balancing across interfaces. Currently
the address alias handling method is colliding with the ECMP code.
For example, when two interfaces are configured on the same prefix,
only one prefix route is installed. So connection load balancing
among the available interfaces is not possible.

The other advantage of ECMP is for failover. The issue with the
current code, is that the interface link-state is not reflected
in the route entry. For example, if there are two interfaces on
the same prefix, the cable on one interface is unplugged, new and
existing connections should switch over to the other interface.
This is not done today and packets go into a black hole.

Also, there is a small bug in the kernel where deleting ECMP routes
in the userland will always return an error even though the command
is successfully executed.

MFC after: 5 days

MFC of 197952 and 198075

Virtualize the pfil hooks so that different jails may chose different
packet filters. ALso allows ipfw to be enabled on on ejail and disabled
on another. In 8.0 it's a global setting.
and
Unbreak the VIMAGE build with IPSEC, broken with r197952 by
virtualizing the pfil hooks.
For consistency add the V_ to virtualize the pfil hooks in here as well.

Make the compiler happy after r201125:
- + remove two unnecessary initializations in ip_output;
+ + remove one unnecessary initializations in ip_output;

introduce a local variable rte acting as a cache of ro->ro_rt
within ip_output, achieving (in random order of importance):
- a reduction of the number of 'r's in the source code;
- improved legibility;
- a reduction of 64 bytes in the .text

+ remove an unused #define print_ip;
+ remove two unnecessary initializations in ip_output;
+ localize 'len';
+ introduce a temporary variable n to count the number of fragments,
the compiler seems unable to identify a common subexpression
(written 3 times, used twice);
+ document some assumptions on ip_len and ip_hl

Remove ifdefed out part of code, which seems to have originated a decade ago
in OpenBSD. As it is now, there is no way for this to be useful, since IPsec
is free to forward packets via whatever interface it wants, so checking
capabilities of the interface passed from ip_output (fetched from the routing
table) serves no purpose.

Discussed with: sam@

Virtualize the pfil hooks so that different jails may chose different
packet filters. ALso allows ipfw to be enabled on on ejail and disabled
on another. In 8.0 it's a global setting.

Sitting aroung in tree waiting to commit for: 2 months
MFC after: 2 months

MFC r196608

Do not try to free the rt_lle entry of the cached route in
ip_output() if the cached route was not initialized from the
flow-table. The rt_lle entry is invalid unless it has been
initialized through the flow-table.

Reviewed by: kmacy, rwatson
Approved by: re

Do not try to free the rt_lle entry of the cached route in
ip_output() if the cached route was not initialized from the
flow-table. The rt_lle entry is invalid unless it has been
initialized through the flow-table.

Reviewed by: kmacy, rwatson
MFC after: immediately

MFC 196368
- change the interface to flowtable_lookup so that we don't rely on
the mbuf for obtaining the fib index
- check that a cached flow corresponds to the same fib index as the
packet for which we are doing the lookup
- at interface detach time flush any flows referencing stale rtentrys
associated with the interface that is going away (fixes reported
panics)
- reduce the time between cleans in case the cleaner is running at
the time the eventhandler is called and the wakeup is missed less
time will elapse before the eventhandler returns
- separate per-vnet initialization from global initialization
(pointed out by jeli@)

Reviewed by: sam@
Approved by: re@

- change the interface to flowtable_lookup so that we don't rely on
the mbuf for obtaining the fib index
- check that a cached flow corresponds to the same fib index as the
packet for which we are doing the lookup
- at interface detach time flush any flows referencing stale rtentrys
associated with the interface that is going away (fixes reported
panics)
- reduce the time between cleans in case the cleaner is running at
the time the eventhandler is called and the wakeup is missed less
time will elapse before the eventhandler returns
- separate per-vnet initialization from global initialization
(pointed out by jeli@)

Reviewed by: sam@
Approved by: re@

MFC 196234

In function ip_output(), the cached route is flushed when there is a
mismatch between the cached entry and the intended destination. The
cached rtentry{} is flushed but the associated llentry{} is not. This
causes the wrong destination MAC address being used in the output
packets. The fix is to flush the llentry{} when rtentry{} is cleared.

Reviewed by: kmacy, rwatson
Approved by: re

In function ip_output(), the cached route is flushed when there is a
mismatch between the cached entry and the intended destination. The
cached rtentry{} is flushed but the associated llentry{} is not. This
causes the wrong destination MAC address being used in the output
packets. The fix is to flush the llentry{} when rtentry{} is cleared.

Reviewed by: kmacy, rwatson
Approved by: re

Merge the remainder of kern_vimage.c and vimage.h into vnet.c and
vnet.h, we now use jails (rather than vimages) as the abstraction
for virtualization management, and what remained was specific to
virtual network stacks. Minor cleanups are done in the process,
and comments updated to reflect these changes.

Reviewed by: bz
Approved by: re (vimage blanket)

Build on Jeff Roberson's linker-set based dynamic per-CPU allocator
(DPCPU), as suggested by Peter Wemm, and implement a new per-virtual
network stack memory allocator. Modify vnet to use the allocator
instead of monolithic global container structures (vinet, ...). This
change solves many binary compatibility problems associated with
VIMAGE, and restores ELF symbols for virtualized global variables.

Each virtualized global variable exists as a "reference copy", and also
once per virtual network stack. Virtualized global variables are
tagged at compile-time, placing the in a special linker set, which is
loaded into a contiguous region of kernel memory. Virtualized global
variables in the base kernel are linked as normal, but those in modules
are copied and relocated to a reserved portion of the kernel's vnet
region with the help of a the kernel linker.

Virtualized global variables exist in per-vnet memory set up when the
network stack instance is created, and are initialized statically from
the reference copy. Run-time access occurs via an accessor macro, which
converts from the current vnet and requested symbol to a per-vnet
address. When "options VIMAGE" is not compiled into the kernel, normal
global ELF symbols will be used instead and indirection is avoided.

This change restores static initialization for network stack global
variables, restores support for non-global symbols and types, eliminates
the need for many subsystem constructors, eliminates large per-subsystem
structures that caused many binary compatibility issues both for
monitoring applications (netstat) and kernel modules, removes the
per-function INIT_VNET_*() macros throughout the stack, eliminates the
need for vnet_symmap ksym(2) munging, and eliminates duplicate
definitions of virtualized globals under VIMAGE_GLOBALS.

Bump __FreeBSD_version and update UPDATING.

Portions submitted by: bz
Reviewed by: bz, zec
Discussed with: gnn, jamie, jeff, jhb, julian, sam
Suggested by: peter
Approved by: re (kensmith)

Modify most routines returning 'struct ifaddr *' to return references
rather than pointers, requiring callers to properly dispose of those
references. The following routines now return references:

ifaddr_byindex
ifa_ifwithaddr
ifa_ifwithbroadaddr
ifa_ifwithdstaddr
ifa_ifwithnet
ifaof_ifpforaddr
ifa_ifwithroute
ifa_ifwithroute_fib
rt_getifa
rt_getifa_fib
IFP_TO_IA
ip_rtaddr
in6_ifawithifp
in6ifa_ifpforlinklocal
in6ifa_ifpwithaddr
in6_ifadd
carp_iamatch6
ip6_getdstifaddr

Remove unused macro which didn't have required referencing:

IFP_TO_IA6

This closes many small races in which changes to interface
or address lists while an ifaddr was in use could lead to use of freed
memory (etc). In a few cases, add missing if_addr_list locking
required to safely acquire references.

Because of a lack of deep copying support, we accept a race in which
an in6_ifaddr pointed to by mbuf tags and extracted with
ip6_getdstifaddr() doesn't hold a reference while in transmit. Once
we have mbuf tag deep copy support, this can be fixed.

Reviewed by: bz
Obtained from: Apple, Inc. (portions)
MFC after: 6 weeks (portions)

V_irtualize flowtable state.

This change should make options VIMAGE kernel builds usable again,
to some extent at least.

Note that the size of struct vnet_inet has changed, though in
accordance with one-bump-per-day policy we didn't update the
__FreeBSD_version number, given that it has already been touched
by r194640 a few hours ago.
Reviewed by: bz
Approved by: julian (mentor)

Move the kernel option FLOWTABLE chacking from the header file to the
actual implementation.
Remove the accessor functions for the compiled out case, just returning
"unavail" values. Remove the kernel conditional from the header file as
it is no longer needed, only leaving the externs.
Hide the improperly virtualized SYSCTL/TUNABLE for the flowtable size
under the kernel option as well.

Reviewed by: rwatson

Only four out of nine arguments for ip_ipsec_output() are actually used.
Kill unused arguments except for 'ifp' as it might be used in the future
for detecting IPsec-capable interfaces.

Move "options MAC" from opt_mac.h to opt_global.h, as it's now in GENERIC
and used in a large number of files, but also because an increasing number
of incorrect uses of MAC calls were sneaking in due to copy-and-paste of
MAC-aware code without the associated opt_mac.h include.

Discussed with: pjd

- Rename IP_NONLOCALOK IP socket option to IP_BINDANY, to be more consistent
with OpenBSD (and BSD/OS originally). We can't easly do it SOL_SOCKET option
as there is no more space for more SOL_SOCKET options, but this option also
fits better as an IP socket option, it seems.
- Implement this functionality also for IPv6 and RAW IP sockets.
- Always compile it in (don't use additional kernel options).
- Remove sysctl to turn this functionality on and off.
- Introduce new privilege - PRIV_NETINET_BINDANY, which allows to use this
functionality (currently only unjail root can use it).

Discussed with: julian, adrian, jhb, rwatson, kmacy

Consolidate and clean up the first section of ip_output.c in light of the
last year or two's work on routing:

- Combine iproute initialization and flowtable lookup blocks, eliminating
unnecessary tests for known-zero'd iproute fields.

- Add a comment indicating (a) why the route entry returned by the
flowtable is considered stable and (b) that the flowtable lookup must
occur after the setup of the mbuf flow ID.

- Assert the inpcb lock before any use of inpcb fields.

Reviewed by: kmacy

Don't require packet to match a route (any route; this information wasn't
used anyway, so a typical workaround was to add a dummy route) if it's going
to be sent through IPSec tunnel.

Reviewed by: bz

- Allocate a small flowtable in ip_input.c (changeable by tuneable)
- Use for accelerating ip_output

Change if_output to take a struct route as its fourth argument in order
to allow passing a cached struct llentry * down to L2

Reviewed by: rwatson

Update stats in struct ipstat using four new macros, IPSTAT_ADD(),
IPSTAT_INC(), IPSTAT_SUB(), and IPSTAT_DEC(), rather than directly
manipulating the fields across the kernel. This will make it easier
to change the implementation of these statistics, such as using
per-CPU versions of the data structures.

MFC after: 3 days

Import "flowid" support for serializing flows across transmit queues

Reviewed by: rwatson and jeli

In ip_output(), do not acquire the IN_MULTI_LOCK(),
and do not attempt to perform a group lookup.
This is a socket layer lock, and the bottom half of IP
really has no business taking it.

Use the value of the in_mcast_loop sysctl to determine
if we should loop back by default, in the absence of
any multicast socket options. Because the check on
group membership is now deferred to the input path,
an m_copym() is now required.

This should increase multicast send performance where the
source has not requested loopback, although this has not been
benchmarked or measured.

It is also a necessary change for IN_MULTI_LOCK to become
non-recursive, which is required in order to implement IGMPv3
in a thread-safe way.

For all files including net/vnet.h directly include opt_route.h and
net/route.h.

Remove the hidden include of opt_route.h and net/route.h from net/vnet.h.

We need to make sure that both opt_route.h and net/route.h are included
before net/vnet.h because of the way MRT figures out the number of FIBs
from the kernel option. If we do not, we end up with the default number
of 1 when including net/vnet.h and array sizes are wrong.

This does not change the list of files which depend on opt_route.h
but we can identify them now more easily.

Try to remove/assimilate as much of formerly IPv4/6 specific
(duplicate) code in sys/netipsec/ipsec.c and fold it into
common, INET/6 independent functions.

The file local functions ipsec4_setspidx_inpcb() and
ipsec6_setspidx_inpcb() were 1:1 identical after the change
in r186528. Rename to ipsec_setspidx_inpcb() and remove the
duplicate.

Public functions ipsec[46]_get_policy() were 1:1 identical.
Remove one copy and merge in the factored out code from
ipsec_get_policy() into the other. The public function left
is now called ipsec_get_policy() and callers were adapted.

Public functions ipsec[46]_set_policy() were 1:1 identical.
Rename file local ipsec_set_policy() function to
ipsec_set_policy_internal().
Remove one copy of the public functions, rename the other
to ipsec_set_policy() and adapt callers.

Public functions ipsec[46]_hdrsiz() were logically identical
(ignoring one questionable assert in the v6 version).
Rename the file local ipsec_hdrsiz() to ipsec_hdrsiz_internal(),
the public function to ipsec_hdrsiz(), remove the duplicate
copy and adapt the callers.
The v6 version had been unused anyway. Cleanup comments.

Public functions ipsec[46]_in_reject() were logically identical
apart from statistics. Move the common code into a file local
ipsec46_in_reject() leaving vimage+statistics in small AF specific
wrapper functions. Note: unfortunately we already have a public
ipsec_in_reject().

Reviewed by: sam
Discussed with: rwatson (renaming to *_internal)
MFC after: 26 days
X-MFC: keep wrapper functions for public symbols?

Adds support for SCTP checksum offload. This means
we, like TCP and UDP, move the checksum calculation
into the IP routines when there is no hardware support
we call into the normal SCTP checksum routine.

The next round of SCTP updates will use
this functionality. Of course the IGB driver needs
a few updates to support the new intel controller set
that actually does SCTP csum offload too.

Reviewed by: gnn, rwatson, kmacy

Fix indentation; add FALLTHROUGH.

Thanks Max!

Implement a new IP option (not compiled/enabled by default) to allow
applications to specify a non-local IP address when bind()'ing a socket
to a local endpoint.

This allows applications to spoof the client IP address of connections
if (obviously!) they somehow are able to receive the traffic normally
destined to said clients.

This patch doesn't include any changes to ipfw or the bridging code to
redirect the client traffic through the PCB checks so TCP gets a shot
at it. The normal behaviour is that packets with a non-local destination
IP address are not handled locally. This can be dealth with some IPFW hackery;
modifications to IPFW to make this less hacky will occur in subsequent
commmits.

Thanks to Julian Elischer and others at Ironport. This work was approved
and donated before Cisco acquired them.

Obtained from: Julian Elischer and others
MFC after: 2 weeks

Allow the IP_MINTTL socket option to be set to 0 so that it can be
disabled entirely, which is its default state before set to a
non-zero value.

PR: 128790
Submitted by: Nick Hilliard <nick at foobar dot org>
MFC after: 3 weeks

This main goals of this project are:
1. separating L2 tables (ARP, NDP) from the L3 routing tables
2. removing as much locking dependencies among these layers as
possible to allow for some parallelism in the search operations
3. simplify the logic in the routing code,

The most notable end result is the obsolescent of the route
cloning (RTF_CLONING) concept, which translated into code reduction
in both IPv4 ARP and IPv6 NDP related modules, and size reduction in
struct rtentry{}. The change in design obsoletes the semantics of
RTF_CLONING, RTF_WASCLONE and RTF_LLINFO routing flags. The userland
applications such as "arp" and "ndp" have been modified to reflect
those changes. The output from "netstat -r" shows only the routing
entries.

Quite a few developers have contributed to this project in the
past: Glebius Smirnoff, Luigi Rizzo, Alessandro Cerri, and
Andre Oppermann. And most recently:

- Kip Macy revised the locking code completely, thus completing
the last piece of the puzzle, Kip has also been conducting
active functional testing
- Sam Leffler has helped me improving/refactoring the code, and
provided valuable reviews
- Julian Elischer setup the perforce tree for me and has helped
me maintaining that branch before the svn conversion

Conditionally compile out V_ globals while instantiating the appropriate
container structures, depending on VIMAGE_GLOBALS compile time option.

Make VIMAGE_GLOBALS a new compile-time option, which by default will not
be defined, resulting in instatiations of global variables selected for
V_irtualization (enclosed in #ifdef VIMAGE_GLOBALS blocks) to be
effectively compiled out. Instantiate new global container structures
to hold V_irtualized variables: vnet_net_0, vnet_inet_0, vnet_inet6_0,
vnet_ipsec_0, vnet_netgraph_0, and vnet_gif_0.

Update the VSYM() macro so that depending on VIMAGE_GLOBALS the V_
macros resolve either to the original globals, or to fields inside
container structures, i.e. effectively

#ifdef VIMAGE_GLOBALS
#define V_rt_tables rt_tables
#else
#define V_rt_tables vnet_net_0._rt_tables
#endif

Update SYSCTL_V_*() macros to operate either on globals or on fields
inside container structs.

Extend the internal kldsym() lookups with the ability to resolve
selected fields inside the virtualization container structs. This
applies only to the fields which are explicitly registered for kldsym()
visibility via VNET_MOD_DECLARE() and vnet_mod_register(), currently
this is done only in sys/net/if.c.

Fix a few broken instances of MODULE_GLOBAL() macro use in SCTP code,
and modify the MODULE_GLOBAL() macro to resolve to V_ macros, which in
turn result in proper code being generated depending on VIMAGE_GLOBALS.

De-virtualize local static variables in sys/contrib/pf/net/pf_subr.c
which were prematurely V_irtualized by automated V_ prepending scripts
during earlier merging steps. PF virtualization will be done
separately, most probably after next PF import.

Convert a few variable initializations at instantiation to
initialization in init functions, most notably in ipfw. Also convert
TUNABLE_INT() initializers for V_ variables to TUNABLE_FETCH_INT() in
initializer functions.

Discussed at: devsummit Strassburg
Reviewed by: bz, julian
Approved by: julian (mentor)
Obtained from: //depot/projects/vimage-commit2/...
X-MFC after: never
Sponsored by: NLnet Foundation, The FreeBSD Foundation

Rather than using hidden includes (with cicular dependencies),
directly include only the header files needed. This reduces the
unneeded spamming of various headers into lots of files.

For now, this leaves us with very few modules including vnet.h
and thus needing to depend on opt_route.h.

Reviewed by: brooks, gnn, des, zec, imp
Sponsored by: The FreeBSD Foundation

Merge more of currently non-functional (i.e. resolving to
whitespace) macros from p4/vimage branch.

Do a better job at enclosing all instantiations of globals
scheduled for virtualization in #ifdef VIMAGE_GLOBALS blocks.

De-virtualize and mark as const saorder_state_alive and
saorder_state_any arrays from ipsec code, given that they are never
updated at runtime, so virtualizing them would be pointless.

Reviewed by: bz, julian
Approved by: julian (mentor)
Obtained from: //depot/projects/vimage-commit2/...
X-MFC after: never
Sponsored by: NLnet Foundation, The FreeBSD Foundation

Fix a scope problem in the multiple routing table code that stopped the
SO_SETFIB socket option from working correctly.

Obtained from: Ironport
MFC after: 3 days

Change the initialization methodology for global variables scheduled
for virtualization.

Instead of initializing the affected global variables at instatiation,
assign initial values to them in initializer functions. As a rule,
initialization at instatiation for such variables should never be
introduced again from now on. Furthermore, enclose all instantiations
of such global variables in #ifdef VIMAGE_GLOBALS blocks.

Essentialy, this change should have zero functional impact. In the next
phase of merging network stack virtualization infrastructure from
p4/vimage branch, the new initialization methology will allow us to
switch between using global variables and their counterparts residing in
virtualization containers with minimum code churn, and in the long run
allow us to intialize multiple instances of such container structures.

Discussed at: devsummit Strassburg
Reviewed by: bz, julian
Approved by: julian (mentor)
Obtained from: //depot/projects/vimage-commit2/...
X-MFC after: never
Sponsored by: NLnet Foundation, The FreeBSD Foundation

- Import the HEAD csup code which is the basis for the cvsmode work.

Step 1.5 of importing the network stack virtualization infrastructure
from the vimage project, as per plan established at devsummit 08/08:
http://wiki.freebsd.org/Image/Notes200808DevSummit

Introduce INIT_VNET_*() initializer macros, VNET_FOREACH() iterator
macros, and CURVNET_SET() context setting macros, all currently
resolving to NOPs.

Prepare for virtualization of selected SYSCTL objects by introducing a
family of SYSCTL_V_*() macros, currently resolving to their global
counterparts, i.e. SYSCTL_V_INT() == SYSCTL_INT().

Move selected #defines from sys/sys/vimage.h to newly introduced header
files specific to virtualized subsystems (sys/net/vnet.h,
sys/netinet/vinet.h etc.).

All the changes are verified to have zero functional impact at this
point in time by doing MD5 comparision between pre- and post-change
object files(*).

(*) netipsec/keysock.c did not validate depending on compile time options.

Implemented by: julian, bz, brooks, zec
Reviewed by: julian, bz, brooks, kris, rwatson, ...
Approved by: julian (mentor)
Obtained from: //depot/projects/vimage-commit2/...
X-MFC after: never
Sponsored by: NLnet Foundation, The FreeBSD Foundation

Fix a bug whereby multicast packets that are looped back locally
wind up with the incorrect checksum on the wire when transmitted via
devices that do checksum offloading.

PR: kern/119635
Reviewed by: rwatson
MFC after: 5 days

Remove comments and #ifdef notyet'd code relating to directly dispatching
the IP multicast input code from the output path; we don't allow
reentrance of the input path from the IP output path, it must use the
netisr due to potential lock recursion.

MFC after: 3 days

Commit step 1 of the vimage project, (network stack)
virtualization work done by Marko Zec (zec@).

This is the first in a series of commits over the course
of the next few weeks.

Mark all uses of global variables to be virtualized
with a V_ prefix.
Use macros to map them back to their global names for
now, so this is a NOP change only.

We hope to have caught at least 85-90% of what is needed
so we do not invalidate a lot of outstanding patches again.

Obtained from: //depot/projects/vimage-commit2/...
Reviewed by: brooks, des, ed, mav, julian,
jamie, kris, rwatson, zec, ...
(various people I forgot, different versions)
md5 (with a bit of help)
Sponsored by: NLnet Foundation, The FreeBSD Foundation
X-MFC after: never
V_Commit_Message_Reviewed_By: more people than the patch

Add code to allow the system to handle multiple routing tables.
This particular implementation is designed to be fully backwards compatible
and to be MFC-able to 7.x (and 6.x)

Currently the only protocol that can make use of the multiple tables is IPv4
Similar functionality exists in OpenBSD and Linux.

From my notes:

-----

One thing where FreeBSD has been falling behind, and which by chance I
have some time to work on is "policy based routing", which allows
different
packet streams to be routed by more than just the destination address.

Constraints:
------------

I want to make some form of this available in the 6.x tree
(and by extension 7.x) , but FreeBSD in general needs it so I might as
well do it in -current and back port the portions I need.

One of the ways that this can be done is to have the ability to
instantiate multiple kernel routing tables (which I will now
refer to as "Forwarding Information Bases" or "FIBs" for political
correctness reasons). Which FIB a particular packet uses to make
the next hop decision can be decided by a number of mechanisms.
The policies these mechanisms implement are the "Policies" referred
to in "Policy based routing".

One of the constraints I have if I try to back port this work to
6.x is that it must be implemented as a EXTENSION to the existing
ABIs in 6.x so that third party applications do not need to be
recompiled in timespan of the branch.

This first version will not have some of the bells and whistles that
will come with later versions. It will, for example, be limited to 16
tables in the first commit.
Implementation method, Compatible version. (part 1)
-------------------------------
For this reason I have implemented a "sufficient subset" of a
multiple routing table solution in Perforce, and back-ported it
to 6.x. (also in Perforce though not always caught up with what I
have done in -current/P4). The subset allows a number of FIBs
to be defined at compile time (8 is sufficient for my purposes in 6.x)
and implements the changes needed to allow IPV4 to use them. I have not
done the changes for ipv6 simply because I do not need it, and I do not
have enough knowledge of ipv6 (e.g. neighbor discovery) needed to do it.

Other protocol families are left untouched and should there be
users with proprietary protocol families, they should continue to work
and be oblivious to the existence of the extra FIBs.

To understand how this is done, one must know that the current FIB
code starts everything off with a single dimensional array of
pointers to FIB head structures (One per protocol family), each of
which in turn points to the trie of routes available to that family.

The basic change in the ABI compatible version of the change is to
extent that array to be a 2 dimensional array, so that
instead of protocol family X looking at rt_tables[X] for the
table it needs, it looks at rt_tables[Y][X] when for all
protocol families except ipv4 Y is always 0.
Code that is unaware of the change always just sees the first row
of the table, which of course looks just like the one dimensional
array that existed before.

The entry points rtrequest(), rtalloc(), rtalloc1(), rtalloc_ign()
are all maintained, but refer only to the first row of the array,
so that existing callers in proprietary protocols can continue to
do the "right thing".
Some new entry points are added, for the exclusive use of ipv4 code
called in_rtrequest(), in_rtalloc(), in_rtalloc1() and in_rtalloc_ign(),
which have an extra argument which refers the code to the correct row.

In addition, there are some new entry points (currently called
rtalloc_fib() and friends) that check the Address family being
looked up and call either rtalloc() (and friends) if the protocol
is not IPv4 forcing the action to row 0 or to the appropriate row
if it IS IPv4 (and that info is available). These are for calling
from code that is not specific to any particular protocol. The way
these are implemented would change in the non ABI preserving code
to be added later.

One feature of the first version of the code is that for ipv4,
the interface routes show up automatically on all the FIBs, so
that no matter what FIB you select you always have the basic
direct attached hosts available to you. (rtinit() does this
automatically).

You CAN delete an interface route from one FIB should you want
to but by default it's there. ARP information is also available
in each FIB. It's assumed that the same machine would have the
same MAC address, regardless of which FIB you are using to get
to it.

This brings us as to how the correct FIB is selected for an outgoing
IPV4 packet.

Firstly, all packets have a FIB associated with them. if nothing
has been done to change it, it will be FIB 0. The FIB is changed
in the following ways.

Packets fall into one of a number of classes.

1/ locally generated packets, coming from a socket/PCB.
Such packets select a FIB from a number associated with the
socket/PCB. This in turn is inherited from the process,
but can be changed by a socket option. The process in turn
inherits it on fork. I have written a utility call setfib
that acts a bit like nice..

setfib -3 ping target.example.com # will use fib 3 for ping.

It is an obvious extension to make it a property of a jail
but I have not done so. It can be achieved by combining the setfib and
jail commands.

2/ packets received on an interface for forwarding.
By default these packets would use table 0,
(or possibly a number settable in a sysctl(not yet)).
but prior to routing the firewall can inspect them (see below).
(possibly in the future you may be able to associate a FIB
with packets received on an interface.. An ifconfig arg, but not yet.)

3/ packets inspected by a packet classifier, which can arbitrarily
associate a fib with it on a packet by packet basis.
A fib assigned to a packet by a packet classifier
(such as ipfw) would over-ride a fib associated by
a more default source. (such as cases 1 or 2).

4/ a tcp listen socket associated with a fib will generate
accept sockets that are associated with that same fib.

5/ Packets generated in response to some other packet (e.g. reset
or icmp packets). These should use the FIB associated with the
packet being reponded to.

6/ Packets generated during encapsulation.
gif, tun and other tunnel interfaces will encapsulate using the FIB
that was in effect withthe proces that set up the tunnel.
thus setfib 1 ifconfig gif0 [tunnel instructions]
will set the fib for the tunnel to use to be fib 1.

Routing messages would be associated with their
process, and thus select one FIB or another.
messages from the kernel would be associated with the fib they
refer to and would only be received by a routing socket associated
with that fib. (not yet implemented)

In addition Netstat has been edited to be able to cope with the
fact that the array is now 2 dimensional. (It looks in system
memory using libkvm (!)). Old versions of netstat see only the first FIB.

In addition two sysctls are added to give:
a) the number of FIBs compiled in (active)
b) the default FIB of the calling process.

Early testing experience:
-------------------------

Basically our (IronPort's) appliance does this functionality already
using ipfw fwd but that method has some drawbacks.

For example,
It can't fully simulate a routing table because it can't influence the
socket's choice of local address when a connect() is done.

Testing during the generating of these changes has been
remarkably smooth so far. Multiple tables have co-existed
with no notable side effects, and packets have been routes
accordingly.

ipfw has grown 2 new keywords:

setfib N ip from anay to any
count ip from any to any fib N

In pf there seems to be a requirement to be able to give symbolic names to the
fibs but I do not have that capacity. I am not sure if it is required.

SCTP has interestingly enough built in support for this, called VRFs
in Cisco parlance. it will be interesting to see how that handles it
when it suddenly actually does something.

Where to next:
--------------------

After committing the ABI compatible version and MFCing it, I'd
like to proceed in a forward direction in -current. this will
result in some roto-tilling in the routing code.

Firstly: the current code's idea of having a separate tree per
protocol family, all of the same format, and pointed to by the
1 dimensional array is a bit silly. Especially when one considers that
there is code that makes assumptions about every protocol having the
same internal structures there. Some protocols don't WANT that
sort of structure. (for example the whole idea of a netmask is foreign
to appletalk). This needs to be made opaque to the external code.

My suggested first change is to add routing method pointers to the
'domain' structure, along with information pointing the data.
instead of having an array of pointers to uniform structures,
there would be an array pointing to the 'domain' structures
for each protocol address domain (protocol family),
and the methods this reached would be called. The methods would have
an argument that gives FIB number, but the protocol would be free
to ignore it.

When the ABI can be changed it raises the possibilty of the
addition of a fib entry into the "struct route". Currently,
the structure contains the sockaddr of the desination, and the resulting
fib entry. To make this work fully, one could add a fib number
so that given an address and a fib, one can find the third element, the
fib entry.

Interaction with the ARP layer/ LL layer would need to be
revisited as well. Qing Li has been working on this already.

This work was sponsored by Ironport Systems/Cisco

Reviewed by: several including rwatson, bz and mlair (parts each)
Obtained from: Ironport systems/Cisco

In ip_output(), allow a read lock as well as a write lock when asserting
a lock on the passed inpcb.

MFC after: 3 months

Convert pcbinfo and inpcb mutexes to rwlocks, and modify macros to
explicitly select write locking for all use of the inpcb mutex.
Update some pcbinfo lock assertions to assert locked rather than
write-locked, although in practice almost all uses of the pcbinfo
rwlock main exclusive, and all instances of inpcb lock acquisition
are exclusive.

This change should introduce (ideally) little functional change.
However, it lays the groundwork for significantly increased
parallelism in the TCP/IP code.

MFC after: 3 months
Tested by: kris (superset of committered patch)

This patch provides the back end support for equal-cost multi-path
(ECMP) for both IPv4 and IPv6. Previously, multipath route insertion
is disallowed. For example,

route add -net 192.103.54.0/24 10.9.44.1
route add -net 192.103.54.0/24 10.9.44.2

The second route insertion will trigger an error message of
"add net 192.103.54.0/24: gateway 10.2.5.2: route already in table"

Multiple default routes can also be inserted. Here is the netstat
output:

default 10.2.5.1 UGS 0 3074 bge0 =>
default 10.2.5.2 UGS 0 0 bge0

When multipath routes exist, the "route delete" command requires
a specific gateway to be specified or else an error message would
be displayed. For example,

route delete default

would fail and trigger the following error message:

"route: writing to routing socket: No such process"
"delete net default: not in table"

On the other hand,

route delete default 10.2.5.2

would be successful: "delete net default: gateway 10.2.5.2"

One does not have to specify a gateway if there is only a single
route for a particular destination.

I need to perform more testings on address aliases and multiple
interfaces that have the same IP prefixes. This patch as it
stands today is not yet ready for prime time. Therefore, the ECMP
code fragments are fully guarded by the RADIX_MPATH macro.
Include the "options RADIX_MPATH" in the kernel configuration
to enable this feature.

Reviewed by: robert, sam, gnn, julian, kmacy

Replaced the misleading uses of a historical artefact M_TRYWAIT with M_WAIT.
Removed dead code that assumed that M_TRYWAIT can return NULL; it's not true
since the advent of MBUMA.

Reviewed by: arch

There are ongoing disputes as to whether we want to switch to directly using
UMA flags M_WAITOK/M_NOWAIT for mbuf(9) allocation.

Rather than passing around a cached 'priv', pass in an ucred to
ipsec*_set_policy and do the privilege check only if needed.

Try to assimilate both ip*_ctloutput code blocks calling ipsec*_set_policy.

Reviewed by: rwatson

Merge first in a series of TrustedBSD MAC Framework KPI changes
from Mac OS X Leopard--rationalize naming for entry points to
the following general forms:

mac_<object>_<method/action>
mac_<object>_check_<method/action>

The previous naming scheme was inconsistent and mostly
reversed from the new scheme. Also, make object types more
consistent and remove spaces from object types that contain
multiple parts ("posix_sem" -> "posixsem") to make mechanical
parsing easier. Introduce a new "netinet" object type for
certain IPv4/IPv6-related methods. Also simplify, slightly,
some entry point names.

All MAC policy modules will need to be recompiled, and modules
not updates as part of this commit will need to be modified to
conform to the new KPI.

Sponsored by: SPARTA (original patches against Mac OS X)
Obtained from: TrustedBSD Project, Apple Computer

Add FBSDID to all files in netinet so that people can more
easily include file version information in bug reports.

Approved by: re (kensmith)

Commit the change from FAST_IPSEC to IPSEC. The FAST_IPSEC
option is now deprecated, as well as the KAME IPsec code.
What was FAST_IPSEC is now IPSEC.

Approved by: re
Sponsored by: Secure Computing

Commit IPv6 support for FAST_IPSEC to the tree.
This commit includes only the kernel files, the rest of the files
will follow in a second commit.

Reviewed by: bz
Approved by: re
Supported by: Secure Computing

Import rewrite of IPv4 socket multicast layer to support source-specific
and protocol-independent host mode multicast. The code is written to
accomodate IPv6, IGMPv3 and MLDv2 with only a little additional work.

This change only pertains to FreeBSD's use as a multicast end-station and
does not concern multicast routing; for an IGMPv3/MLDv2 router
implementation, consider the XORP project.

The work is based on Wilbert de Graaf's IGMPv3 code drop for FreeBSD 4.6,
which is available at: http://www.kloosterhof.com/wilbert/igmpv3.html

Summary
* IPv4 multicast socket processing is now moved out of ip_output.c
into a new module, in_mcast.c.
* The in_mcast.c module implements the IPv4 legacy any-source API in
terms of the protocol-independent source-specific API.
* Source filters are lazy allocated as the common case does not use them.
They are part of per inpcb state and are covered by the inpcb lock.
* struct ip_mreqn is now supported to allow applications to specify
multicast joins by interface index in the legacy IPv4 any-source API.
* In UDP, an incoming multicast datagram only requires that the source
port matches the 4-tuple if the socket was already bound by source port.
An unbound socket SHOULD be able to receive multicasts sent from an
ephemeral source port.
* The UDP socket multicast filter mode defaults to exclusive, that is,
sources present in the per-socket list will be blocked from delivery.
* The RFC 3678 userland functions have been added to libc: setsourcefilter,
getsourcefilter, setipv4sourcefilter, getipv4sourcefilter.
* Definitions for IGMPv3 are merged but not yet used.
* struct sockaddr_storage is now referenced from <netinet/in.h>. It
is therefore defined there if not already declared in the same way
as for the C99 types.
* The RFC 1724 hack (specify 0.0.0.0/8 addresses to IP_MULTICAST_IF
which are then interpreted as interface indexes) is now deprecated.
* A patch for the Rhyolite.com routed in the FreeBSD base system
is available in the -net archives. This only affects individuals
running RIPv1 or RIPv2 via point-to-point and/or unnumbered interfaces.
* Make IPv6 detach path similar to IPv4's in code flow; functionally same.
* Bump __FreeBSD_version to 700048; see UPDATING.

This work was financially supported by another FreeBSD committer.

Obtained from: p4://bms_netdev
Submitted by: Wilbert de Graaf (original work)
Reviewed by: rwatson (locking), silence from fenner,
net@ (but with encouragement)

Move universally to ANSI C function declarations, with relatively
consistent style(9)-ish layout.

Purge two redundant case labels.

Fix undirected broadcast sends for the case where SO_DONTROUTE has also
been set at the socket layer, in our somewhat convoluted IPv4 source
selection logic in ip_output().

IP_ONESBCAST is actually a special case of SO_DONTROUTE, as 255.255.255.255
must always be delivered on a local link with a TTL of 1.

If IP_ONESBCAST has been set at the socket layer, also perform destination
interface lookup for point-to-point interfaces based on the destination
address of the link; previously it was not possible to use the option with
such interfaces; also, the destination/broadcast address fields map to the
same field within struct ifnet, which doesn't help matters.

One more valid fix going forward for these issues is to treat 255.255.255.255
as a destination in its own right in the forwarding trie. Other
implementations do this. It fits with the use of multiple paths, though
it then becomes necessary to specify interface preference.
This hack will eventually go away when that comes to pass.

Reviewed by: andre
MFC after: 1 week

Back out revision 1.264.

Fixing the IP accounting issue, if we plan to do so, needs to be better
thought out; the 'fix' introduces a hash lookup and a possible kernel panic.

Reported by: Mark Tinguely

Sweep kernel replacing suser(9) calls with priv(9) calls, assigning
specific privilege names to a broad range of privileges. These may
require some future tweaking.

Sponsored by: nCircle Network Security, Inc.
Obtained from: TrustedBSD Project
Discussed on: arch@
Reviewed (at least in part) by: mlaier, jmg, pjd, bde, ceri,
Alex Lyashkov <umka at sevcity dot net>,
Skip Ford <skip dot ford at verizon dot net>,
Antoine Brodin <antoine dot brodin at laposte dot net>

Complete break-out of sys/sys/mac.h into sys/security/mac/mac_framework.h
begun with a repo-copy of mac.h to mac_framework.h. sys/mac.h now
contains the userspace and user<->kernel API and definitions, with all
in-kernel interfaces moved to mac_framework.h, which is now included
across most of the kernel instead.

This change is the first step in a larger cleanup and sweep of MAC
Framework interfaces in the kernel, and will not be MFC'd.

Obtained from: TrustedBSD Project
Sponsored by: SPARTA

Remove stone-aged and irrelevant "#ifndef notdef".

Account for output IP datagrams on the ifaddr where they originated from,
*not* the first ifaddr on the ifp. This is similar to what NetBSD does.

PR: kern/72936
Submitted by: alfred
Reviewed by: andre

Fix a NULL pointer dereference of ro->ro_rt->rt_flags by checking for the
validity of ro->ro_rt first. This prevents crashing on any non-normally
routed IP packet.

Coverity CID: 162 (incorrectly, it was re-introduced by previous commit)

make use of the host route's mtu for processing. This means we can now
support a network w/ split mtu's by assigning each host route the correct
mtu. an aspiring programmer could write a daemon to probe hosts and find
out if they support a larger mtu.

First step of TSO (TCP segmentation offload) support in our network stack.

o add IFCAP_TSO[46] for drivers to announce this capability for IPv4 and IPv6
o add CSUM_TSO flag to mbuf pkthdr csum_flags field
o add tso_segsz field to mbuf pkthdr
o enhance ip_output() packet length check to allow for large TSO packets
o extend tcp_maxmtu[46]() with a flag pointer to pass interface capabilities
o adjust all callers of tcp_maxmtu[46]() accordingly

Discussed on: -current, -net
Sponsored by: TCP/IP Optimization Fundraise 2005

Fix the socket option IP_ONESBCAST by giving it its own case in ip_output()
and skip over the normal IP processing.

Add a supporting function ifa_ifwithbroadaddr() to verify and validate the
supplied subnet broadcast address.

PR: kern/99558
Tested by: Andrey V. Elsukov <bu7cher-at-yandex.ru>
Sponsored by: TCP/IP Optimization Fundraise 2005
MFC after: 3 days

Remove the IPFIREWALL_FORWARD_EXTENDED option and make it on by default as it always was
in older versions of FreeBSD. This option is pointless as it is needed in just
about every interesting usage of forward that I have ever seen. It doesn't make
the system any safer and just wastes huge amounts of develper time
when the system doesn't behave as expected when code is moved from
4.x to 6.x It doesn't make
the system any safer and just wastes huge amounts of develper time
when the system doesn't behave as expected when code is moved from
4.x to 6.x or 7.x
Reviewed by: glebius
MFC after: 1 week

Fix URL to Bellovin's paper.

Submitted by: Anton Yuzhaninov <citrin rambler-co.ru>

o Add missed error check: in ip_ctloutput() sooptcopyin() returns a
result but we never examine it.

Reviewed by: rwatson
MFC after: 2 weeks

Fix a long-standing limitation in IPv4 multicast group membership.

By making the imo_membership array a dynamically allocated vector,
this minimizes disruption to existing IPv4 multicast code. This
change breaks the ABI for the kernel module ip_mroute.ko, and may
cause a small amount of churn for folks working on the IGMPv3 merge.

Previously, sockets were subject to a compile-time limitation on
the number of IPv4 group memberships, which was hard-coded to 20.
The imo_membership relationship, however, is 1:1 with regards to
a tuple of multicast group address and interface address. Users who
ran routing protocols such as OSPF ran into this limitation on machines
with a large system interface tree.

Somewhat re-factor the read/write locking mechanism associated with the packet
filtering mechanisms to use the new rwlock(9) locking API:

- Drop the variables stored in the phil_head structure which were specific to
conditions and the home rolled read/write locking mechanism.
- Drop some includes which were used for condition variables
- Drop the inline functions, and convert them to macros. Also, move these
macros into pfil.h
- Move pfil list locking macros intp phil.h as well
- Rename ph_busy_count to ph_nhooks. This variable will represent the number
of IN/OUT hooks registered with the pfil head structure
- Define PFIL_HOOKED macro which evaluates to true if there are any
hooks to be ran by pfil_run_hooks
- In the IP/IP6 stacks, change the ph_busy_count comparison to use the new
PFIL_HOOKED macro.
- Drop optimization in pfil_run_hooks which checks to see if there are any
hooks to be ran, and returns if not. This check is already performed by the
IP stacks when they call:

if (!PFIL_HOOKED(ph))
goto skip_hooks;

- Drop in assertion which makes sure that the number of hooks never drops
below 0 for good measure. This in theory should never happen, and if it
does than there are problems somewhere
- Drop special logic around PFIL_WAITOK because rw_wlock(9) does not sleep
- Drop variables which support home rolled read/write locking mechanism from
the IPFW firewall chain structure.
- Swap out the read/write firewall chain lock internal to use the rwlock(9)
API instead of our home rolled version
- Convert the inlined functions to macros

Reviewed by: mlaier, andre, glebius
Thanks to: jhb for the new locking API

Move the IPSEC related code blocks to their own file to unclutter
and signifincantly improve the readability of ip_input() and
ip_output() again.

The resulting IPSEC hooks in ip_input() and ip_output() may be
used later on for making IPSEC loadable.

This move is mostly mechanical and should preserve current IPSEC
behaviour as-is. Nothing shall prevent improvements in the way
IPSEC interacts with the IPv4 stack.

Discussed with: bz, gnn, rwatson; (earlier version)

In in_delayed_cksum() we can't perform a m_pullup() as it may
change the mbuf pointer and we don't have any way of passing
it back to the callers. Instead just fail silently without
updating the checksum but leaving the mbuf+chain intact.

A search in our GNATS database did not turn up any match for
the existing warning message when this case is encountered.

Found by: Coverity Prevent(tm)
Coverity ID: CID779
Sponsored by: TCP/IP Optimization Fundraise 2005
MFC after: 3 days

Prevent dereferencing a NULL route pointer when trying to update the
route MTU.

This bug is very difficult to reach and not remotely exploitable.

Found by: Coverity Prevent(tm)
Coverity ID: CID162
Sponsored by: TCP/IP Optimization Fundraise 2005
MFC after: 3 days

When we drop packet due to no space in output interface output queue, also
increase the ifp->if_snd.ifq_drops.

PR: 72440
Submitted by: ikob

Consolidate all IP Options handling functions into ip_options.[ch] and
include ip_options.h into all files making use of IP Options functions.

From ip_input.c rev 1.306:
ip_dooptions(struct mbuf *m, int pass)
save_rte(m, option, dst)
ip_srcroute(m0)
ip_stripoptions(m, mopt)

From ip_output.c rev 1.249:
ip_insertoptions(m, opt, phlen)
ip_optcopy(ip, jp)
ip_pcbopts(struct inpcb *inp, int optname, struct mbuf *m)

No functional changes in this commit.

Discussed with: rwatson
Sponsored by: TCP/IP Optimization Fundraise 2005

Purge layer specific mbuf flags on layer crossings to avoid confusing
upper or lower layers.

Sponsored by: TCP/IP Optimization Fundraise 2005

Retire MT_HEADER mbuf type and change its users to use MT_DATA.

Having an additional MT_HEADER mbuf type is superfluous and redundant
as nothing depends on it. It only adds a layer of confusion. The
distinction between header mbuf's and data mbuf's is solely done
through the m->m_flags M_PKTHDR flag.

Non-native code is not changed in this commit. For compatibility
MT_HEADER is mapped to MT_DATA.

Sponsored by: TCP/IP Optimization Fundraise 2005

Implement IP_DONTFRAG IP socket option enabling the Don't Fragment
flag on IP packets. Currently this option is only repected on udp
and raw ip sockets. On tcp sockets the DF flag is controlled by the
path MTU discovery option.

Sending a packet larger than the MTU size of the egress interface
returns an EMSGSIZE error.

Discussed with: rwatson
Sponsored by: TCP/IP Optimization Fundraise 2005

Use the correct mbuf type for MGET().

Add socketoption IP_MINTTL. May be used to set the minimum acceptable
TTL a packet must have when received on a socket. All packets with a
lower TTL are silently dropped. Works on already connected/connecting
and listening sockets for RAW/UDP/TCP.

This option is only really useful when set to 255 preventing packets
from outside the directly connected networks reaching local listeners
on sockets.

Allows userland implementation of 'The Generalized TTL Security Mechanism
(GTSM)' according to RFC3682. Examples of such use include the Cisco IOS
BGP implementation command "neighbor ttl-security".

MFC after: 2 weeks
Sponsored by: TCP/IP Optimization Fundraise 2005

Add helper function ip_findmoptions(), which accepts an inpcb, and attempts
to atomically return either an existing set of IP multicast options for the
PCB, or a newlly allocated set with default values. The inpcb is returned
locked. This function may sleep.

Call ip_moptions() to acquire a reference to a PCB's socket options, and
perform the update of the options while holding the PCB lock. Release the
lock before returning.

Remove garbage collection of multicast options when values return to the
default, as this complicates locking substantially. Most applications
allocate a socket either to be multicast, or not, and don't tend to keep
around sockets that have previously been used for multicast, then used for
unicast.

This closes a number of race conditions involving multiple threads or
processes modifying the IP multicast state of a socket simultaenously.

MFC after: 7 days

Introduce in_multi_mtx, which will protect IPv4-layer multicast address
lists, as well as accessor macros. For now, this is a recursive mutex
due code sequences where IPv4 multicast calls into IGMP calls into
ip_output(), which then tests for a multicast forwarding case.

For support macros in in_var.h to check multicast address lists, assert
that in_multi_mtx is held.

Acquire in_multi_mtx around iteration over the IPv4 multicast address
lists, such as in ip_input() and ip_output().

Acquire in_multi_mtx when manipulating the IPv4 layer multicast addresses,
as well as over the manipulation of ifnet multicast address lists in order
to keep the two layers in sync.

Lock down accesses to IPv4 multicast addresses in IGMP, or assert the
lock when performing IGMP join/leave events.

Eliminate spl's associated with IPv4 multicast addresses, portions of
IGMP that weren't previously expunged by IGMP locking.

Add in_multi_mtx, igmp_mtx, and if_addr_mtx lock order to hard-coded
lock order in WITNESS, in that order.

Problem reported by: Ed Maste <emaste at phaedrus dot sandvine dot ca>
MFC after: 10 days

Eliminate MAC entry point mac_create_mbuf_from_mbuf(), which is
redundant with respect to existing mbuf copy label routines. Expose
a new mac_copy_mbuf() routine at the top end of the Framework and
use that; use the existing mpo_copy_mbuf_label() routine on the
bottom end.

Obtained from: TrustedBSD Project
Sponsored by: SPARTA, SPAWAR
Approved by: re (scottl)

Stop embedding struct ifnet at the top of driver softcs. Instead the
struct ifnet or the layer 2 common structure it was embedded in have
been replaced with a struct ifnet pointer to be filled by a call to the
new function, if_alloc(). The layer 2 common structure is also allocated
via if_alloc() based on the interface type. It is hung off the new
struct ifnet member, if_l2com.

This change removes the size of these structures from the kernel ABI and
will allow us to better manage them as interfaces come and go.

Other changes of note:
- Struct arpcom is no longer referenced in normal interface code.
Instead the Ethernet address is accessed via the IFP2ENADDR() macro.
To enforce this ac_enaddr has been renamed to _ac_enaddr.
- The second argument to ether_ifattach is now always the mac address
from driver private storage rather than sometimes being ac_enaddr.

Reviewed by: sobomax, sam

Bring back the full packet destination manipulation for 'ipfw fwd'
with the kernel compile time option:

options IPFIREWALL_FORWARD_EXTENDED

This option has to be specified in addition to IPFIRWALL_FORWARD.

With this option even packets targeted for an IP address local
to the host can be redirected. All restrictions to ensure proper
behaviour for locally generated packets are turned off. Firewall
rules have to be carefully crafted to make sure that things like
PMTU discovery do not break.

Document the two kernel options.

PR: kern/71910
PR: kern/73129
MFC after: 1 week

Correctly move the packet header in ip_insertoptions().

Reported by: Anupam Chanda
Reviewed by: sam@
MFC after: 2 weeks

/* -> /*- for license, minor formatting changes

Remove an errant blank line apparently introduced in
ip_output.c:1.194.

Pass the inpcb reference into ip_getmoptions() rather than just the
inp->inp_moptions pointer, so that ip_getmoptions() can perform
necessary locking when doing non-atomic reads.

Lock the inpcb by default to copy any data to local variables, then
unlock before performing sooptcopyout().

MFC after: 2 weeks

Push the inpcb argument into ip_setmoptions() when setting IP multicast
socket options, so that it is available for locking.

Start working through inpcb locking for ip_ctloutput() by cleaning up
modifications to the inpcb IP options mbuf:

- Lock the inpcb before passing it into ip_pcbopts() in order to prevent
simulatenous reads and read-modify-writes that could result in races.
- Pass the inpcb reference into ip_pcbopts() instead of the option chain
pointer in the inpcb.
- Assert the inpcb lock in ip_pcbots.
- Convert one or two uses of a pointer as a boolean or an integer
comparison to a comparison with NULL for readability.

Add an additional struct inpcb * argument to pfil(9) in order to enable
passing along socket information. This is required to work around a LOR with
the socket code which results in an easy reproducible hard lockup with
debug.mpsafenet=1. This commit does *not* fix the LOR, but enables us to do
so later. The missing piece is to turn the filter locking into a leaf lock
and will follow in a seperate (later) commit.

This will hopefully be MT5'ed in order to fix the problem for RELENG_5 in
forseeable future.

Suggested by: rwatson
A lot of work by: csjp (he'd be even more helpful w/o mentor-reviews ;)
Reviewed by: rwatson, csjp
Tested by: -pf, -ipfw, LINT, csjp and myself
MFC after: 3 days

LOR IDs: 14 - 17 (not fixed yet)

Make comments more clear for the packet changed cases after pfil hooks.

revert comment from rev1.158 now that rev1.225 backed it out..

MFC after: 3 days

In the case the destination of a packet was changed by the packet filter
to point to a local IP address; and the packet was sourced from this host
we fill in the m_pkthdr.rcvif with a pointer to the loopback interface.

Before the function ifunit("lo0") was used to obtain the ifp. However
this is sub-optimal from a performance point of view and might be dangerous
if the loopback interface has been renamed. Use the global variable 'loif'
instead which always points to the loopback interface.

Submitted by: brooks

Always compile PFIL_HOOKS into the kernel and remove the associated kernel
compile option. All FreeBSD packet filters now use the PFIL_HOOKS API and
thus it becomes a standard part of the network stack.

If no hooks are connected the entire packet filter hooks section and related
activities are jumped over. This removes any performance impact if no hooks
are active.

Both OpenBSD and DragonFlyBSD have integrated PFIL_HOOKS permanently as well.

Allow early drop for non-ALTQ enabled queues in an ALTQ-enabled kernel.
Previously the early drop was disabled unconditionally for ALTQ-enabled
kernels.

This should give some benefit for the normal gateway + LAN-server case with
a busy LAN leg and an ALTQ managed uplink.

Reviewed and style help from: cperciva, pjd

Make the kernel compile again if you are not using PFIL_HOOKS

Convert ipfw to use PFIL_HOOKS. This is change is transparent to userland
and preserves the ipfw ABI. The ipfw core packet inspection and filtering
functions have not been changed, only how ipfw is invoked is different.

However there are many changes how ipfw is and its add-on's are handled:

In general ipfw is now called through the PFIL_HOOKS and most associated
magic, that was in ip_input() or ip_output() previously, is now done in
ipfw_check_[in|out]() in the ipfw PFIL handler.

IPDIVERT is entirely handled within the ipfw PFIL handlers. A packet to
be diverted is checked if it is fragmented, if yes, ip_reass() gets in for
reassembly. If not, or all fragments arrived and the packet is complete,
divert_packet is called directly. For 'tee' no reassembly attempt is made
and a copy of the packet is sent to the divert socket unmodified. The
original packet continues its way through ip_input/output().

ipfw 'forward' is done via m_tag's. The ipfw PFIL handlers tag the packet
with the new destination sockaddr_in. A check if the new destination is a
local IP address is made and the m_flags are set appropriately. ip_input()
and ip_output() have some more work to do here. For ip_input() the m_flags
are checked and a packet for us is directly sent to the 'ours' section for
further processing. Destination changes on the input path are only tagged
and the 'srcrt' flag to ip_forward() is set to disable destination checks
and ICMP replies at this stage. The tag is going to be handled on output.
ip_output() again checks for m_flags and the 'ours' tag. If found, the
packet will be dropped back to the IP netisr where it is going to be picked
up by ip_input() again and the directly sent to the 'ours' section. When
only the destination changes, the route's 'dst' is overwritten with the
new destination from the forward m_tag. Then it jumps back at the route
lookup again and skips the firewall check because it has been marked with
M_SKIP_FIREWALL. ipfw 'forward' has to be compiled into the kernel with
'option IPFIREWALL_FORWARD' to enable it.

DUMMYNET is entirely handled within the ipfw PFIL handlers. A packet for
a dummynet pipe or queue is directly sent to dummynet_io(). Dummynet will
then inject it back into ip_input/ip_output() after it has served its time.
Dummynet packets are tagged and will continue from the next rule when they
hit the ipfw PFIL handlers again after re-injection.

BRIDGING and IPFW_ETHER are not changed yet and use ipfw_chk() directly as
they did before. Later this will be changed to dedicated ETHER PFIL_HOOKS.

More detailed changes to the code:

conf/files
Add netinet/ip_fw_pfil.c.

conf/options
Add IPFIREWALL_FORWARD option.

modules/ipfw/Makefile
Add ip_fw_pfil.c.

net/bridge.c
Disable PFIL_HOOKS if ipfw for bridging is active. Bridging ipfw
is still directly invoked to handle layer2 headers and packets would
get a double ipfw when run through PFIL_HOOKS as well.

netinet/ip_divert.c
Removed divert_clone() function. It is no longer used.

netinet/ip_dummynet.[ch]
Neither the route 'ro' nor the destination 'dst' need to be stored
while in dummynet transit. Structure members and associated macros
are removed.

netinet/ip_fastfwd.c
Removed all direct ipfw handling code and replace it with the new
'ipfw forward' handling code.

netinet/ip_fw.h
Removed 'ro' and 'dst' from struct ip_fw_args.

netinet/ip_fw2.c
(Re)moved some global variables and the module handling.

netinet/ip_fw_pfil.c
New file containing the ipfw PFIL handlers and module initialization.

netinet/ip_input.c
Removed all direct ipfw handling code and replace it with the new
'ipfw forward' handling code. ip_forward() does not longer require
the 'next_hop' struct sockaddr_in argument. Disable early checks
if 'srcrt' is set.

netinet/ip_output.c
Removed all direct ipfw handling code and replace it with the new
'ipfw forward' handling code.

netinet/ip_var.h
Add ip_reass() as general function. (Used from ipfw PFIL handlers
for IPDIVERT.)

netinet/raw_ip.c
Directly check if ipfw and dummynet control pointers are active.

netinet/tcp_input.c
Rework the 'ipfw forward' to local code to work with the new way of
forward tags.

netinet/tcp_sack.c
Remove include 'opt_ipfw.h' which is not needed here.

sys/mbuf.h
Remove m_claim_next() macro which was exclusively for ipfw 'forward'
and is no longer needed.

Approved by: re (scottl)

Get rid of the RANDOM_IP_ID option and make it a sysctl. NetBSD
have already done this, so I have styled the patch on their work:

1) introduce a ip_newid() static inline function that checks
the sysctl and then decides if it should return a sequential
or random IP ID.

2) named the sysctl net.inet.ip.random_id

3) IPv6 flow IDs and fragment IDs are now always random.
Flow IDs and frag IDs are significantly less common in the
IPv6 world (ie. rarely generated per-packet), so there should
be smaller performance concerns.

The sysctl defaults to 0 (sequential IP IDs).

Reviewed by: andre, silby, mlaier, ume
Based on: NetBSD
MFC after: 2 months

Consistently use NULL for pointer comparisons.

Make a comment that "ipfw forward" is not SMP and PREEMPTION safe.

o Delayed checksums are now calculated in divert_packet() for diverted packets
Remove the XXX-escaped code that did it in ip_output()'s IPHACK section.

In ip_ctloutput(), acquire the inpcb lock around some of the basic
inpcb flag and status updates.

Link ALTQ to the build and break with ABI for struct ifnet. Please recompile
your (network) modules as well as any userland that might make sense of
sizeof(struct ifnet).
This does not change the queueing yet. These changes will follow in a
seperate commit. Same with the driver changes, which need case by case
evaluation.

__FreeBSD_version bump will follow.

Tested-by: (i386)LINT

o Calculate a number of bytes to copy (cnt) correctly:

+----+-+-+-+-+----+----+- - - - - - - - - - - - -+----+
| | |C| | | | | | |
| IP |N|O|L|P| | IP | | IP |
| #1 |O|D|E|T| | #2 | | #n |
| |P|E|N|R| | | | |
+----+-+-+-+-+----+----+- - - - - - - - - - - - -+----+
^ ^<---- cnt - (IPOPT_MINOFF - 1) ---->|
| |
src | +-- cp[IPOPT_OFF + 1] + sizeof(struct in_addr)
|
dst +-- cp[IPOPT_OFF + 1]

PR: kern/66386
Submitted by: Andrei Iltchenko
MFC after: 3 weeks

Rename m_claim_next_hop() to m_claim_next(), as suggested by Max Laier.

Rename ip_claim_next_hop() to m_claim_next_hop(), give it an extra arg
(the type of tag to claim) and push it out of ip_var.h into mbuf.h alongside
all of the other macros that work ok mbuf's and tag's.

In an effort to simplify the routing code, try to deprecate rtalloc()
in favour of rtalloc_ign(), which is what would end up being called
anyways.

There are 25 more instances of rtalloc() in net*/ and
about 10 instances of rtalloc_ign()