MFC r304572 (by bz):
Remove the kernel optoion for IPSEC_FILTERTUNNEL, which was deprecated
more than 7 years ago in favour of a sysctl in r192648.

MFC r305122:
Remove redundant sanity checks from ipsec[46]_common_input_cb().

This check already has been done in the each protocol callback.

MFC r309144,309174,309201 (by fabient):
IPsec RFC6479 support for replay window sizes up to 2^32 - 32 packets.

Since the previous algorithm, based on bit shifting, does not scale
with large replay windows, the algorithm used here is based on
RFC 6479: IPsec Anti-Replay Algorithm without Bit Shifting.
The replay window will be fast to be updated, but will cost as many bits
in RAM as its size.

The previous implementation did not provide a lock on the replay window,
which may lead to replay issues.

Obtained from: emeric.poupon@stormshield.eu
Sponsored by: Stormshield
Differential Revision: https://reviews.freebsd.org/D8468

MFC r309143,309146 (by fabient):
In a dual processor system (2*6 cores) during IPSec throughput tests,
we see a lot of contention on the arc4 lock, used to generate the IV
of the ESP output packets.

The idea of this patch is to split this mutex in order to reduce the
contention on this lock.

Update r309143 to prevent false sharing.

Reviewed by: delphij, markm, ache
Approved by: so
Obtained from: emeric.poupon@stormshield.eu
Sponsored by: Stormshield
Differential Revision: https://reviews.freebsd.org/D8130

MFC r313330:
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.

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

MFC r313331:
Add removed headers into the ObsoleteFiles.inc.

MFC r313561 (by glebius):
Move tcp_fields_to_net() static inline into tcp_var.h, just below its
friend tcp_fields_to_host(). There is third party code that also uses
this inline.

MFC r313697:
Remove IPsec related PCB code from SCTP.

The inpcb structure has inp_sp pointer that is initialized by
ipsec_init_pcbpolicy() function. This pointer keeps strorage for IPsec
security policies associated with a specific socket.
An application can use IP_IPSEC_POLICY and IPV6_IPSEC_POLICY socket
options to configure these security policies. Then ip[6]_output()
uses inpcb pointer to specify that an outgoing packet is associated
with some socket. And IPSEC_OUTPUT() method can use a security policy
stored in the inp_sp. For inbound packet the protocol-specific input
routine uses IPSEC_CHECK_POLICY() method to check that a packet conforms
to inbound security policy configured in the inpcb.

SCTP protocol doesn't specify inpcb for ip[6]_output() when it sends
packets. Thus IPSEC_OUTPUT() method does not consider such packets as
associated with some socket and can not apply security policies
from inpcb, even if they are configured. Since IPSEC_CHECK_POLICY()
method is called from protocol-specific input routine, it can specify
inpcb pointer and associated with socket inbound policy will be
checked. But there are two problems:
1. Such check is asymmetric, becasue we can not apply security policy
from inpcb for outgoing packet.
2. IPSEC_CHECK_POLICY() expects that caller holds INPCB lock and
access to inp_sp is protected. But for SCTP this is not correct,
becasue SCTP uses own locks to protect inpcb.

To fix these problems remove IPsec related PCB code from SCTP.
This imply that IP_IPSEC_POLICY and IPV6_IPSEC_POLICY socket options
will be not applicable to SCTP sockets. To be able correctly check
inbound security policies for SCTP, mark its protocol header with
the PR_LASTHDR flag.

Differential Revision: https://reviews.freebsd.org/D9538

MFC r313746:
Add missing check to fix the build with IPSEC_SUPPORT and without MAC.

MFC r313805:
Fix LINT build for powerpc.

Build kernel modules support only when both IPSEC and TCP_SIGNATURE
are not defined.

MFC r313922:
For translated packets do not adjust UDP checksum if it is zero.

In case when decrypted and decapsulated packet is an UDP datagram,
check that its checksum is not zero before doing incremental checksum
adjustment.

MFC r314339:
Document that the size of AH ICV for HMAC-SHA2-NNN should be half of
NNN bits as described in RFC4868.

PR: 215978

MFC r314812:
Introduce the concept of IPsec security policies scope.

Currently are defined three scopes: global, ifnet, and pcb.
Generic security policies that IKE daemon can add via PF_KEY interface
or an administrator creates with setkey(8) utility have GLOBAL scope.
Such policies can be applied by the kernel to outgoing packets and checked
agains inbound packets after IPsec processing.
Security policies created by if_ipsec(4) interfaces have IFNET scope.
Such policies are applied to packets that are passed through if_ipsec(4)
interface.
And security policies created by application using setsockopt()
IP_IPSEC_POLICY option have PCB scope. Such policies are applied to
packets related to specific socket. Currently there is no way to list
PCB policies via setkey(8) utility.

Modify setkey(8) and libipsec(3) to be able distinguish the scope of
security policies in the `setkey -DP` listing. Add two optional flags:
'-t' to list only policies related to virtual *tunneling* interfaces,
i.e. policies with IFNET scope, and '-g' to list only policies with GLOBAL
scope. By default policies from all scopes are listed.

To implement this PF_KEY's sadb_x_policy structure was modified.
sadb_x_policy_reserved field is used to pass the policy scope from the
kernel to userland. SADB_SPDDUMP message extended to support filtering
by scope: sadb_msg_satype field is used to specify bit mask of requested
scopes.

For IFNET policies the sadb_x_policy_priority field of struct sadb_x_policy
is used to pass if_ipsec's interface if_index to the userland. For GLOBAL
policies sadb_x_policy_priority is used only to manage order of security
policies in the SPDB. For IFNET policies it is not used, so it can be used
to keep if_index.

After this change the output of `setkey -DP` now looks like:
# setkey -DPt
0.0.0.0/0[any] 0.0.0.0/0[any] any
in ipsec
esp/tunnel/87.250.242.144-87.250.242.145/unique:145
spid=7 seq=3 pid=58025 scope=ifnet ifname=ipsec0
refcnt=1
# setkey -DPg
::/0 ::/0 icmp6 135,0
out none
spid=5 seq=1 pid=872 scope=global
refcnt=1

Obtained from: Yandex LLC
Sponsored by: Yandex LLC
Differential Revision: https://reviews.freebsd.org/D9805

PR: 212018
Relnotes: yes
Sponsored by: Yandex LLC

MFC r315225:

Discard first 3072 bytes of RC4 keystream, this is a bandaid
that allows us to work on switching to a more modern PRNG.

Submitted by: Steven Chamberlain <steven pyro eu org>
Approved by: so

Copy head@r302406 to stable/11 as part of the 11.0-RELEASE cycle.
Prune svn:mergeinfo from the new branch, as nothing has been merged
here.

Additional commits post-branch will follow.

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

Huge cleanup of random(4) code.

* GENERAL
- Update copyright.
- Make kernel options for RANDOM_YARROW and RANDOM_DUMMY. Set
neither to ON, which means we want Fortuna
- If there is no 'device random' in the kernel, there will be NO
random(4) device in the kernel, and the KERN_ARND sysctl will
return nothing. With RANDOM_DUMMY there will be a random(4) that
always blocks.
- Repair kern.arandom (KERN_ARND sysctl). The old version went
through arc4random(9) and was a bit weird.
- Adjust arc4random stirring a bit - the existing code looks a little
suspect.
- Fix the nasty pre- and post-read overloading by providing explictit
functions to do these tasks.
- Redo read_random(9) so as to duplicate random(4)'s read internals.
This makes it a first-class citizen rather than a hack.
- Move stuff out of locked regions when it does not need to be
there.
- Trim RANDOM_DEBUG printfs. Some are excess to requirement, some
behind boot verbose.
- Use SYSINIT to sequence the startup.
- Fix init/deinit sysctl stuff.
- Make relevant sysctls also tunables.
- Add different harvesting "styles" to allow for different requirements
(direct, queue, fast).
- Add harvesting of FFS atime events. This needs to be checked for
weighing down the FS code.
- Add harvesting of slab allocator events. This needs to be checked for
weighing down the allocator code.
- Fix the random(9) manpage.
- Loadable modules are not present for now. These will be re-engineered
when the dust settles.
- Use macros for locks.
- Fix comments.

* src/share/man/...
- Update the man pages.

* src/etc/...
- The startup/shutdown work is done in D2924.

* src/UPDATING
- Add UPDATING announcement.

* src/sys/dev/random/build.sh
- Add copyright.
- Add libz for unit tests.

* src/sys/dev/random/dummy.c
- Remove; no longer needed. Functionality incorporated into randomdev.*.

* live_entropy_sources.c live_entropy_sources.h
- Remove; content moved.
- move content to randomdev.[ch] and optimise.

* src/sys/dev/random/random_adaptors.c src/sys/dev/random/random_adaptors.h
- Remove; plugability is no longer used. Compile-time algorithm
selection is the way to go.

* src/sys/dev/random/random_harvestq.c src/sys/dev/random/random_harvestq.h
- Add early (re)boot-time randomness caching.

* src/sys/dev/random/randomdev_soft.c src/sys/dev/random/randomdev_soft.h
- Remove; no longer needed.

* src/sys/dev/random/uint128.h
- Provide a fake uint128_t; if a real one ever arrived, we can use
that instead. All that is needed here is N=0, N++, N==0, and some
localised trickery is used to manufacture a 128-bit 0ULLL.

* src/sys/dev/random/unit_test.c src/sys/dev/random/unit_test.h
- Improve unit tests; previously the testing human needed clairvoyance;
now the test will do a basic check of compressibility. Clairvoyant
talent is still a good idea.
- This is still a long way off a proper unit test.

* src/sys/dev/random/fortuna.c src/sys/dev/random/fortuna.h
- Improve messy union to just uint128_t.
- Remove unneeded 'static struct fortuna_start_cache'.
- Tighten up up arithmetic.
- Provide a method to allow eternal junk to be introduced; harden
it against blatant by compress/hashing.
- Assert that locks are held correctly.
- Fix the nasty pre- and post-read overloading by providing explictit
functions to do these tasks.
- Turn into self-sufficient module (no longer requires randomdev_soft.[ch])

* src/sys/dev/random/yarrow.c src/sys/dev/random/yarrow.h
- Improve messy union to just uint128_t.
- Remove unneeded 'staic struct start_cache'.
- Tighten up up arithmetic.
- Provide a method to allow eternal junk to be introduced; harden
it against blatant by compress/hashing.
- Assert that locks are held correctly.
- Fix the nasty pre- and post-read overloading by providing explictit
functions to do these tasks.
- Turn into self-sufficient module (no longer requires randomdev_soft.[ch])
- Fix some magic numbers elsewhere used as FAST and SLOW.

Differential Revision: https://reviews.freebsd.org/D2025
Reviewed by: vsevolod,delphij,rwatson,trasz,jmg
Approved by: so (delphij)

Attempt to mitigate poor initialization of arc4 by one-shot
reinitialization from yarrow right after good entropy is harvested.

Approved by: secteam (delphij)
MFC after: 1 week

Return arc4_i = arc4_j = 0; line from previous backing out since
just found it in OpenBSD, see their sys/crypto/arc4.c, function
rc4_keysetup, line ctx->x = ctx->y = 0;

Obtained from: OpenBSD

Per rwatson's request:
"If you don't get a review within a day or two, I would firmly recommend
backing out the changes"

back out all my changes as unreviewed by secteam@ yet.

1) Initialize arc4_i and arc4_j to 0 after key mixing as recommended in
draft-kaukonen-cipher-arcfour-03.txt (3.1.5)

2) Drop first 768 bytes as standard RC4-drop(768)

Lock down arc4random so it can be safely called w/o Giant.

Minor code reorganization was required, but the only functional
change was that the first 1024 bytes of output are thrown out
after each reseed, rather than just the initial seed.

Use __FBSDID().

Slight overhaul of arc4random() and friends.

One bug fixed: Use getmicrouptime() to trigger reseeds so that we
cannot be tricked by a clock being stepped backwards.

Express parameters in natural units and with natural names.

Don't use struct timeval more than we need to.

Various stylistic and readability polishing.

Introduce arc4rand(void *ptr, u_int len, int reseed) function which
returns a stream of pseudo-random bytes, observing the automatic
reseed criteria as well as allowing forced reseeds.

Rewrite arc4random() in terms of arc4rand().

Sponsored by: DARPA & NAI Labs.

Fixed some typos, verboseness and misformatting in comments.

Minor improvements to arc4random():

- Decrease reseeding interval from every 64 to every 16384 runs
to reduce entropy usage.
- Add time based reseeding. (Every 5 minutes.)
- Throw away the first 256 words of output as suggested in
"Weaknesses in the Key Scheduling Algorithm of RC4."

Reviewed by: Mark Murray
MFC After: jkh says ok

Recouple arc4random(9) to the entropy device. This works whether the
entropy device is loaded or not.

If the entropy device is NOT loaded, the the quality of perturbations
supplied by this will suffer.

Back out previous revision now that sys/random.h is properly fixed.

Add #include's of sys/proc.h and sys/param.h to silence a warning.

Comment out unavailable call. This needs to be revisited when the entropy
device is complete.
Reviewed by: dfr

In the extremely miniscule chance that read_random returns <= 0, don't try
and use that return code as a modulus (panics are bad, mmmkay?)

Address the concerns of the ``randomness'' of the initial PRNG. Now, we
use bits from /dev/random to stir the S-box. Also add an internal counter to
keep the S-box stirred on a regular basis.

Reviewed by: msmith

Introduce OpenBSD-like Random PIDs. Controlled by a sysctl knob
(kern.randompid), which is currently defaulted off. Use ARC4 (RC4) for our
random number generation, which will not get me executed for violating
crypto laws; a Good Thing(tm).

Reviewed and Approved by: bde, imp