dumpon: fix set but not used variable

Signed-off-by: inkeliz <inkeliz@inkeliz.com>

Reviewed by: markj
MFC after: 1 week
Pull Request: https://github.com/freebsd/freebsd-src/pull/1178

Remove copyright strings ifdef'd out

We've ifdef'd out the copyright strings for some time now. Go ahead and
remove the ifdefs. Plus whatever other detritis was left over from other
recent removals. These copyright strings are present in the comments and
are largely from CSRG's attempt at adding their copyright to every
binary file (which modern interpretations of the license doesn't
require).

Sponsored by: Netflix

sbin: 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

Remove $FreeBSD$: one-line .c pattern

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

dumpon: update OpenSSL initialization call

ERR_load_crypto_strings() was deprecated in OpenSSL 1.1.0, and explicit
initialization is generally not reqiured. In the case of dumpon however
we initialize prior to entering capability mode, so replace with an
OPENSSL_init_crypto call.

Reviewed by: def, Pierre Pronchery
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D40353

dumpon: provide diag info when `PEM_read_RSA_PUBKEY` fails

This change modifies dumpon to print out the last error from OpenSSL
when `PEM_read_RSA_PUBKEY` fails. This allows end-users to diagnose why
reading in RSA pubkey files fails so they can adjust the usage to meet
the needs of the command.

MFC after: 1 week

dumpon: warn if the configured netdump link is down

Previously we expected the DIOCSKERNELDUMP ioctl to return ENXIO if the
interface was down, but it does not actually do this. Grab the link
status using getifaddrs(3) instead, and downgrade this case from an
error to a warning; the user might bring the link back up at a later
time.

Reviewed by: cem
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D35196

dumpon: proceed without compression if the kernel lacks support

PR: 252554
Reviewed by: markj
MFC after: 1 week
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D34520

dumpon: fix build on some architectures

Fix a -Wsign-compare issue on some architectures.

Fixes: 96f9bd46547d6dfbaf219ab449efacacb0dacccc
Pointy hat to: me
MFC after: 1 week
Sponsored by: Dell EMC Isilon

dumpon: fix encrypted dumps after commit 372557d8c3d

That commit moved key generation into a child process, including
a memory allocation referenced by a structure. The child wrote
the structure to the parent over a pipe, but did not write the
referenced allocation. The parent read the structure from the
child and used its pointer, which was bogus in the parent.

In the child, send both chunks of data to the parent. In the
parent, make a corresponding allocation and read both chunks.

Fixes: 372557d8c3d37dd0c1d9be56513a436393963848
Reviewed by: bdrewery, markj
MFC after: 1 week
Sponsored by: Dell EMC Isilon
Differential Revision: https://reviews.freebsd.org/D31452

dumpon: Fix unconfiguring netdump with "off" and "/dev/null".

Netdump has its own configuration tracking such that
ioctl(/dev/null, DIOCSKERNELDUMP) does a dumper_remove() but does not
notify netdump about the removal. Simply sending the same ioctl to
/dev/netdump handles the situation.

Reviewed by: markj, cem
Sponsored by: Dell EMC
Differential Revision: https://reviews.freebsd.org/D31300

dumpon: Fix -v causing error when configuring an encrypted dump

If -v is specified when adding a new device then a full listing of
configured devices is displayed. This requires sysctl access which
genkey()'s use of capability mode was blocking permission to access.
This leads to both confusing console spam but also incorrectly returning
an error status even if no other had been encountered.

dumpon: Sysctl get 'kern.shutdown.dumpdevname': Operation not permitted

Fix this by generating the key in a child process.

Reviewed by: markj
Sponsored by: Dell EMC
Differential Revision: https://reviews.freebsd.org/D31266

dumpon: do not print errno for resolver failure

When the netdump host name fails to resolve, don't print errno, since
it's irrelevant. We might as well use a different exit status, too.

Sponsored by: Dell EMC Isilon

EKCD: Preload error strings, PRNG seed; use OAEP padding

Preload OpenSSL ERR string data so that the formatted error messages are
vaguely meaningful. Add OpenSSL error information to the RSA_public_encrypt()
operation failure case in one-time key generation.

For obsolescent OpenSSL versions (*cough* FIPS *cough*), pre-seed the PRNG
before entering Cap mode, as old versions of OpenSSL are unaware of kernel
RNG interfaces aside from /dev/random (such as the long-supported kern.arnd, or
the slightly more recent getentropy(3) or getrandom(2)). (RSA_public_encrypt()
wants a seeded PRNG to randomize the "PS" portion of PKCS 1.5 padding or the
"MGF" pseudo-random function in OAEP padding.)

Switch dumpon to encrypt the one-time key with OAEP padding (recommended since
1998; RFC2437) rather than the obsolescent PKCS 1.5 padding (1993; RFC2313).

Switch decryptcore to attempt OAEP decryption first, and try PKCS 1.5
decryption on failure. This is intended only for transition convenience, and
we should obsolete support for non-OAEP padding in a release or two.

Reviewed by: markj
MFC After: 2 weeks
Sponsored by: Dell EMC Isilon
Differential Revision: https://reviews.freebsd.org/D24534

dumpon: skip size check if using zstd

As with gzip, let the dump device be smaller than physical memory
when using zstd and full dumps.

Also print the error message if the size check fails, even if -v
is not specified. Failing silently is not friendly.

Reviewed by: cem markj
MFC after: 2 weeks
Sponsored by: Dell EMC Isilon
Differential Revision: https://reviews.freebsd.org/D23923

EKCD: Add Chacha20 encryption mode

Add Chacha20 mode to Encrypted Kernel Crash Dumps.

Chacha20 does not require messages to be multiples of block size, so it is
valid to use the cipher on non-block-sized messages without the explicit
padding AES-CBC would require. Therefore, allow use with simultaneous dump
compression. (Continue to disallow use of AES-CBC EKCD with compression.)

dumpon(8) gains a -C cipher flag to select between chacha and aes-cbc.
It defaults to chacha if no -C option is provided. The man page documents this
behavior.

Relnotes: sure
Sponsored by: Dell EMC Isilon

List-ify kernel dump device configuration

Allow users to specify multiple dump configurations in a prioritized list.
This enables fallback to secondary device(s) if primary dump fails. E.g.,
one might configure a preference for netdump, but fallback to disk dump as a
second choice if netdump is unavailable.

This change does not list-ify netdump configuration, which is tracked
separately from ordinary disk dumps internally; only one netdump
configuration can be made at a time, for now. It also does not implement
IPv6 netdump.

savecore(8) is already capable of scanning and iterating multiple devices
from /etc/fstab or passed on the command line.

This change doesn't update the rc or loader variables 'dumpdev' in any way;
it can still be set to configure a single dump device, and rc.d/savecore
still uses it as a single device. Only dumpon(8) is updated to be able to
configure the more complicated configurations for now.

As part of revving the ABI, unify netdump and disk dump configuration ioctl
/ structure, and leave room for ipv6 netdump as a future possibility.
Backwards-compatibility ioctls are added to smooth ABI transition,
especially for developers who may not keep kernel and userspace perfectly
synced.

Reviewed by: markj, scottl (earlier version)
Relnotes: maybe
Sponsored by: Dell EMC Isilon
Differential Revision: https://reviews.freebsd.org/D19996

Avoid clobbering a user-specified -g value after r340547.

CID: 1396919
MFC with: r340547

Change dumpon(8)'s handling of -g.

Rather than using a special value to denote "use the default router",
treat the absence of the -g option to mean the same thing. The
in-kernel netdump client will always attempt to reach the server
directly before falling back to the configured gateway anyway. This
change makes it cleaner to support a hostname value for -g.

Reviewed by: cem
MFC after: 3 days
Differential Revision: https://reviews.freebsd.org/D18025

dumpon(8): Provide seatbelt against weak RSA keys

The premise of dumpon -k foo.pem is that dump contents will be confidential
except to anyone holding the corresponding RSA private key.

This guarantee breaks down when weak RSA keys are used. Small RSA keys
(e.g. 512 bits) can be broken on a single personal computer in tractible
time. Marginal RSA keys (768 bits) can be broken by EC2 and a few dollars.
Even 1024 bit keys can probably be broken by sophisticated and wealthy
attackers.

NIST SP800-57 (2016) recommends a minimum of 2048 bit RSA keys, and
estimates this provides 112 bits of security.

It would also be good to protect users from weak values of 'e' (i.e., 3) and
perhaps sanity check that their public key .pem does not accidentally
contain their private key as well. These considerations are left as future
work.

Reviewed by: markj, darius AT dons.net.au (previous version)
Discussed with: bjk
Differential Revision: https://reviews.freebsd.org/D17678

Convert `cap_enter() < 0 && errno != ENOSYS` to `caph_enter() < 0`.

No functional change intended.

dumpon(8)
- fix the WITHOUT_CRYPTO buildworld case. Its rare, but some of us do
build this way.

Sponsored by: Limelight Networks

Add netdump support to dumpon(8).

A new usage is added so that parameters for netdump may be specified.
Specifically, one configures an interface for netdump with:

# dumpon -c <client IP> -s <server IP> [-g <gateway IP>] <iface name>

Reviewed by: bdrewery, cem (earlier versions), sbruno
MFC after: 1 month
Sponsored by: Dell EMC Isilon
Differential Revision: https://reviews.freebsd.org/D15254

Add support for zstd-compressed user and kernel core dumps.

This works similarly to the existing gzip compression support, but
zstd is typically faster and gives better compression ratios.

Support for this functionality must be configured by adding ZSTDIO to
one's kernel configuration file. dumpon(8)'s new -Z option is used to
configure zstd compression for kernel dumps. savecore(8) now recognizes
and saves zstd-compressed kernel dumps with a .zst extension.

Submitted by: cem (original version)
Relnotes: yes
Sponsored by: Dell EMC Isilon
Differential Revision: https://reviews.freebsd.org/D13101,
https://reviews.freebsd.org/D13633

General 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.

Add support for compressed kernel dumps.

When using a kernel built with the GZIO config option, dumpon -z can be
used to configure gzip compression using the in-kernel copy of zlib.
This is useful on systems with large amounts of RAM, which require a
correspondingly large dump device. Recovery of compressed dumps is also
faster since fewer bytes need to be copied from the dump device.

Because we have no way of knowing the final size of a compressed dump
until it is written, the kernel will always attempt to dump when
compression is configured, regardless of the dump device size. If the
dump is aborted because we run out of space, an error is reported on
the console.

savecore(8) is modified to handle compressed dumps and save them to
vmcore.<index>.gz, as it does when given the -z option.

A new rc.conf variable, dumpon_flags, is added. Its value is added to
the boot-time dumpon(8) invocation that occurs when a dump device is
configured in rc.conf.

Reviewed by: cem (earlier version)
Discussed with: def, rgrimes
Relnotes: yes
Sponsored by: Dell EMC Isilon
Differential Revision: https://reviews.freebsd.org/D11723

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

Add support for encrypted kernel crash dumps.

Changes include modifications in kernel crash dump routines, dumpon(8) and
savecore(8). A new tool called decryptcore(8) was added.

A new DIOCSKERNELDUMP I/O control was added to send a kernel crash dump
configuration in the diocskerneldump_arg structure to the kernel.
The old DIOCSKERNELDUMP I/O control was renamed to DIOCSKERNELDUMP_FREEBSD11 for
backward ABI compatibility.

dumpon(8) generates an one-time random symmetric key and encrypts it using
an RSA public key in capability mode. Currently only AES-256-CBC is supported
but EKCD was designed to implement support for other algorithms in the future.
The public key is chosen using the -k flag. The dumpon rc(8) script can do this
automatically during startup using the dumppubkey rc.conf(5) variable. Once the
keys are calculated dumpon sends them to the kernel via DIOCSKERNELDUMP I/O
control.

When the kernel receives the DIOCSKERNELDUMP I/O control it generates a random
IV and sets up the key schedule for the specified algorithm. Each time the
kernel tries to write a crash dump to the dump device, the IV is replaced by
a SHA-256 hash of the previous value. This is intended to make a possible
differential cryptanalysis harder since it is possible to write multiple crash
dumps without reboot by repeating the following commands:
# sysctl debug.kdb.enter=1
db> call doadump(0)
db> continue
# savecore

A kernel dump key consists of an algorithm identifier, an IV and an encrypted
symmetric key. The kernel dump key size is included in a kernel dump header.
The size is an unsigned 32-bit integer and it is aligned to a block size.
The header structure has 512 bytes to match the block size so it was required to
make a panic string 4 bytes shorter to add a new field to the header structure.
If the kernel dump key size in the header is nonzero it is assumed that the
kernel dump key is placed after the first header on the dump device and the core
dump is encrypted.

Separate functions were implemented to write the kernel dump header and the
kernel dump key as they need to be unencrypted. The dump_write function encrypts
data if the kernel was compiled with the EKCD option. Encrypted kernel textdumps
are not supported due to the way they are constructed which makes it impossible
to use the CBC mode for encryption. It should be also noted that textdumps don't
contain sensitive data by design as a user decides what information should be
dumped.

savecore(8) writes the kernel dump key to a key.# file if its size in the header
is nonzero. # is the number of the current core dump.

decryptcore(8) decrypts the core dump using a private RSA key and the kernel
dump key. This is performed by a child process in capability mode.
If the decryption was not successful the parent process removes a partially
decrypted core dump.

Description on how to encrypt crash dumps was added to the decryptcore(8),
dumpon(8), rc.conf(5) and savecore(8) manual pages.

EKCD was tested on amd64 using bhyve and i386, mipsel and sparc64 using QEMU.
The feature still has to be tested on arm and arm64 as it wasn't possible to run
FreeBSD due to the problems with QEMU emulation and lack of hardware.

Designed by: def, pjd
Reviewed by: cem, oshogbo, pjd
Partial review: delphij, emaste, jhb, kib
Approved by: pjd (mentor)
Differential Revision: https://reviews.freebsd.org/D4712

Use nitems() instead of sizeof(name) / sizeof(*name).

MFC after: 2 weeks.

Fix dumpon compatibility with dumpdev kenv

The dumpdev kenv supports devices without the /dev/ prefix, fix dumpon to
also support this which is required after r288153.

MFC after: 1 week
Sponsored by: Multiplay

Document that you can use -v along with -l.

Noticed by: pjd

Add an option to display the current dump device via dumpon -l.

MFC after: 2 weeks

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

Create the altix project branch. The altix project will add support
for the SGI Altix 350 to FreeBSD/ia64. The hardware used for porting
is a two-module system, consisting of a base compute module and a
CPU expansion module. SGI's NUMAFlex architecture can be an excellent
platform to test CPU affinity and NUMA-aware features in FreeBSD.

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

Whitespace and style nits.

With minidumps, the dumping partition could be smaller than physical
memory, so checking the size of the partition is not necessary.

Tested by: kris

Promote mediasize and physmem to uintmax_t when comparing them.

Whitespace nit.

Verify that the specified device is at least as large as hw.physmem.

Remove advertising clause from University of California Regent's license,
per letter dated July 22, 1999.

Approved by: core, imp

Use __FBSDID() to quiet GCC 3.3 warnings.

unbreak build: include string.h for strcmp prototype.

Rename DIOCGKERNELDUMP to DIOCSKERNELDUMP as it strictly speaking
is a "set" not a "get" operation.

Sponsored by: DARPA & NAI Labs.

Move generic disk ioctls from <sys/disklabel.h> to <sys/disk.h>.

Sponsored by: DARPA & NAI Labs

Here follows the new kernel dumping infrastructure.

Caveats:

The new savecore program is not complete in the sense that it emulates
enough of the old savecores features to do the job, but implements none
of the options yet.

I would appreciate if a userland hacker could help me out getting savecore
to do what we want it to do from a users point of view, compression,
email-notification, space reservation etc etc. (send me email if
you are interested).

Currently, savecore will scan all devices marked as "swap" or "dump" in
/etc/fstab _or_ any devices specified on the command-line.

All architectures but i386 lack an implementation of dumpsys(), but
looking at the i386 version it should be trivial for anybody familiar
with the platform(s) to provide this function.

Documentation is quite sparse at this time, more to come.

Sponsored by: DARPA, NAI Labs

Details:

Dumpon now opens the device and uses ioctl(DIOCGKERNELDUMP) to set it
to be the dumpdevice. When "off" is set, /dev/null is used.

o __P
o Strict ANSI declarations.
o return (foo);
o main (int, char *[])

Include missing header files which define functions for which gcc has
builtins (e.g., exit, strcmp).

Remove unused #include.

The dumpon sysctl only accept cdevs thse days.

Submitted by: bde

Accept both types of devices to work with older kernels too
Fix confusing message

Convert dumpon to work on character devices instead of block devices.

NB: You may need to change your /etc/rc.conf!

$Id$ -> $FreeBSD$

Capitalize at the start of sentence. Add rcsid. Remove unused #includes.
Use `dumpon' instead of argv[0].

compare return value from getopt against -1 rather than EOF, per the final
posix standard on the topic.

Revert $FreeBSD$ to $Id$

Make the long-awaited change from $Id$ to $FreeBSD$

This will make a number of things easier in the future, as well as (finally!)
avoiding the Id-smashing problem which has plagued developers for so long.

Boy, I'm glad we're not using sup anymore. This update would have been
insane otherwise.

Remove trailing whitespace.

My utility to specify where you want crash dumps to go. More user
and kernel support to follow.