Copy stable/9 to releng/9.3 as part of the 9.3-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

MFC r258578, r258580, r258581 (by hrs):
Replace Sun RPC license in TI-RPC library with a 3-clause BSD license
with the explicit permissions.

MFC r241141, r241165, r241165, r241181;

rpc: convert all uid and gid variables to u_int.

Follow a similar change in Solaris and linux where the uid and
gid variables were made more similar to what the system expects.
In our case we use u_int which is what XDR can manage,

Reviewed by: bde

MFC r241007, r241008:

Complete revert of r239963 (from head).

The attempt to merge changes from the linux libtirpc caused
rpc.lockd to exit after startup under unclear conditions.

Reported by: David Wolfskill

MFC r239963:

Bring some changes from Bull's NFSv4 libtirpc implementation.

____

Fixed infinite loop in svc_run()
____

__rpc_taddr2uaddr_af() assumes the netbuf to always have a
non-zero data. This is a bad assumption and can lead to a
seg-fault. This patch adds a check for zero length and returns
NULL when found.
____

Changed clnt_spcreateerror() to return clearer
and more concise error messages.
____

Converted all uid and gid variables of the type uid_t and gid_t.
____

libtirpc: set r_netid and r_owner in __rpcb_findaddr_timed

These fields in the rpcbind GETADDR call are being passed uninitialized
to CLNT_CALL. In the case of x86_64 at least, this usually leads to a
segfault. On x86, it sometimes causes segfaults and other times causes
garbage to be sent on the wire.

rpcbind generally ignores the r_owner field for calls that come in over
the wire, so it really doesn't matter what we send in that slot. We just
need to send something. The reference implementation from Sun seems to
send a blank string. Have ours follow suit.
____

libtirpc: be sure to free cl_netid and cl_tp

When creating a client with clnt_tli_create, it uses strdup to copy
strings for these fields if nconf is passed in. clnt_dg_destroy frees
these strings already. Make sure clnt_vc_destroy frees them in the same
way.

____

Obtained from: Bull GNU/Linux NFSv4 Project

Copy head to stable/9 as part of 9.0-RELEASE release cycle.

Approved by: re (implicit)

Implement support for RPCSEC_GSS authentication to both the NFS client
and server. This replaces the RPC implementation of the NFS client and
server with the newer RPC implementation originally developed
(actually ported from the userland sunrpc code) to support the NFS
Lock Manager. I have tested this code extensively and I believe it is
stable and that performance is at least equal to the legacy RPC
implementation.

The NFS code currently contains support for both the new RPC
implementation and the older legacy implementation inherited from the
original NFS codebase. The default is to use the new implementation -
add the NFS_LEGACYRPC option to fall back to the old code. When I
merge this support back to RELENG_7, I will probably change this so
that users have to 'opt in' to get the new code.

To use RPCSEC_GSS on either client or server, you must build a kernel
which includes the KGSSAPI option and the crypto device. On the
userland side, you must build at least a new libc, mountd, mount_nfs
and gssd. You must install new versions of /etc/rc.d/gssd and
/etc/rc.d/nfsd and add 'gssd_enable=YES' to /etc/rc.conf.

As long as gssd is running, you should be able to mount an NFS
filesystem from a server that requires RPCSEC_GSS authentication. The
mount itself can happen without any kerberos credentials but all
access to the filesystem will be denied unless the accessing user has
a valid ticket file in the standard place (/tmp/krb5cc_<uid>). There
is currently no support for situations where the ticket file is in a
different place, such as when the user logged in via SSH and has
delegated credentials from that login. This restriction is also
present in Solaris and Linux. In theory, we could improve this in
future, possibly using Brooks Davis' implementation of variant
symlinks.

Supporting RPCSEC_GSS on a server is nearly as simple. You must create
service creds for the server in the form 'nfs/<fqdn>@<REALM>' and
install them in /etc/krb5.keytab. The standard heimdal utility ktutil
makes this fairly easy. After the service creds have been created, you
can add a '-sec=krb5' option to /etc/exports and restart both mountd
and nfsd.

The only other difference an administrator should notice is that nfsd
doesn't fork to create service threads any more. In normal operation,
there will be two nfsd processes, one in userland waiting for TCP
connections and one in the kernel handling requests. The latter
process will create as many kthreads as required - these should be
visible via 'top -H'. The code has some support for varying the number
of service threads according to load but initially at least, nfsd uses
a fixed number of threads according to the value supplied to its '-n'
option.

Sponsored by: Isilon Systems
MFC after: 1 month

Add the new kernel-mode NFS Lock Manager. To use it instead of the
user-mode lock manager, build a kernel with the NFSLOCKD option and
add '-k' to 'rpc_lockd_flags' in rc.conf.

Highlights include:

* Thread-safe kernel RPC client - many threads can use the same RPC
client handle safely with replies being de-multiplexed at the socket
upcall (typically driven directly by the NIC interrupt) and handed
off to whichever thread matches the reply. For UDP sockets, many RPC
clients can share the same socket. This allows the use of a single
privileged UDP port number to talk to an arbitrary number of remote
hosts.

* Single-threaded kernel RPC server. Adding support for multi-threaded
server would be relatively straightforward and would follow
approximately the Solaris KPI. A single thread should be sufficient
for the NLM since it should rarely block in normal operation.

* Kernel mode NLM server supporting cancel requests and granted
callbacks. I've tested the NLM server reasonably extensively - it
passes both my own tests and the NFS Connectathon locking tests
running on Solaris, Mac OS X and Ubuntu Linux.

* Userland NLM client supported. While the NLM server doesn't have
support for the local NFS client's locking needs, it does have to
field async replies and granted callbacks from remote NLMs that the
local client has contacted. We relay these replies to the userland
rpc.lockd over a local domain RPC socket.

* Robust deadlock detection for the local lock manager. In particular
it will detect deadlocks caused by a lock request that covers more
than one blocking request. As required by the NLM protocol, all
deadlock detection happens synchronously - a user is guaranteed that
if a lock request isn't rejected immediately, the lock will
eventually be granted. The old system allowed for a 'deferred
deadlock' condition where a blocked lock request could wake up and
find that some other deadlock-causing lock owner had beaten them to
the lock.

* Since both local and remote locks are managed by the same kernel
locking code, local and remote processes can safely use file locks
for mutual exclusion. Local processes have no fairness advantage
compared to remote processes when contending to lock a region that
has just been unlocked - the local lock manager enforces a strict
first-come first-served model for both local and remote lockers.

Sponsored by: Isilon Systems
PR: 95247 107555 115524 116679
MFC after: 2 weeks