MFC 331248: Set the proper vnet in IPsec callback functions.

When using hardware crypto engines, the callback functions used to handle
an IPsec packet after it has been encrypted or decrypted can be invoked
asynchronously from a worker thread that is not associated with a vnet.
Extend 'struct xform_data' to include a vnet pointer and save the current
vnet in this new member when queueing crypto requests in IPsec. In the
IPsec callback routines, use the new member to set the current vnet while
processing the modified packet.

This fixes a panic when using hardware offload such as ccr(4) with IPsec
after VIMAGE was enabled in GENERIC.

Sponsored by: Chelsio Communications

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

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

RFC4868 section 2.3 requires that the output be half... This fixes
problems that was introduced in r285336... I have verified that
HMAC-SHA2-256 both ah only and w/ AES-CBC interoperate w/ a NetBSD
6.1.5 vm...

Reviewed by: gnn

Remove xform_ipip.c and code related to XF_IP4.

The only thing is used from this code is ipip_output() function, that does
IPIP encapsulation. Other parts of XF_IP4 code were removed in r275133.
Also it isn't possible to configure the use of XF_IP4, nor from userland
via setkey(8), nor from the kernel.

Simplify the ipip_output() function and rename it to ipsec_encap().
* move IP_DF handling from ipsec4_process_packet() into ipsec_encap();
* since ipsec_encap() called from ipsec[64]_process_packet(), it
is safe to assume that mbuf is contiguous at least to IP header
for used IP version. Remove all unneeded m_pullup(), m_copydata
and related checks.
* use V_ip_defttl and V_ip6_defhlim for outer headers;
* use V_ip4_ipsec_ecn and V_ip6_ipsec_ecn for outer headers;
* move all diagnostic messages to the ipsec_encap() callers;
* simplify handling of ipsec_encap() results: if it returns non zero
value, print diagnostic message and free mbuf.
* some style(9) fixes.

Differential Revision: https://reviews.freebsd.org/D2303
Reviewed by: glebius
Sponsored by: Yandex LLC

Remove ip4_input() declaration. It was removed in r275133.

MFC after: 1 month

Do not use xform_ipip as decapsulation fallback.

xform_ipip was used as fallback with low priority for IPIP
encapsulated packets that were decrypted. In some cases
it can decapsulate packets, that it shouldn't. This leads to situations,
when wrong configurations are magically working. Also it can propagate
wrong ingress interface and this can break security.

Now we redesigned the IPSEC code and IPIP encapsulation is called directly
from ipsec_output, and decapsulation is done in the ipsec_input with m_striphdr.

Differential Revision: https://reviews.freebsd.org/D1220
MFC after: 1 month
Sponsored by: Yandex LLC

Merge 'struct ip6protosw' and 'struct protosw' into one. Now we have
only one protocol switch structure that is shared between ipv4 and ipv6.

Phabric: D476
Reviewed by: jhb

Optimisation in IPSEC(4):
- Remove contention on ISR during the crypto operation by using rwlock(9).
- Remove a second lookup of the SA in the callback.

Gain on 6 cores CPU with SHA1/AES128 can be up to 30%.

Reviewed by: vanhu
MFC after: 1 month

Fixed IPsec's HMAC_SHA256-512 support to be RFC4868 compliant.
This will break interoperability with all older versions of
FreeBSD for those algorithms.

Reviewed by: bz, gnn
Obtained from: NETASQ
MFC after: 1w

Add sysctls to if_enc(4) to control whether the firewalls or
bpf will see inner and outer headers or just inner or outer
headers for incoming and outgoing IPsec packets.

This is useful in bpf to not have over long lines for debugging
or selcting packets based on the inner headers.
It also properly defines the behavior of what the firewalls see.

Last but not least it gives you if_enc(4) for IPv6 as well.

[ As some auxiliary state was not available in the later
input path we save it in the tdbi. That way tcpdump can give a
consistent view of either of (authentic,confidential) for both
before and after states. ]

Discussed with: thompsa (2007-04-25, basic idea of unifying paths)
Reviewed by: thompsa, gnn

Fix more stack corruptions on amd64.

Vararg functions have a different calling convention than regular
functions on amd64. Casting a varag function to a regular one to
match the function pointer declaration will hide the varargs from
the caller and we will end up with an incorrectly setup stack.

Entirely remove the varargs from these functions and change the
functions to match the declaration of the function pointers.
Remove the now unnecessary casts.

Also change static struct ipprotosw[] to two independent
protosw/ip6protosw definitions to remove an unnecessary cast.

PR: amd64/95008
Submitted and tested by: Mats Palmgren
Reviewed by: rwatson
MFC after: 3 days

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

"Fast IPsec": this is an experimental IPsec implementation that is derived
from the KAME IPsec implementation, but with heavy borrowing and influence
of openbsd. A key feature of this implementation is that it uses the kernel
crypto framework to do all crypto work so when h/w crypto support is present
IPsec operation is automatically accelerated. Otherwise the protocol
implementations are rather differet while the SADB and policy management
code is very similar to KAME (for the moment).

Note that this implementation is enabled with a FAST_IPSEC option. With this
you get all protocols; i.e. there is no FAST_IPSEC_ESP option.

FAST_IPSEC and IPSEC are mutually exclusive; you cannot build both into a
single system.

This software is well tested with IPv4 but should be considered very
experimental (i.e. do not deploy in production environments). This software
does NOT currently support IPv6. In fact do not configure FAST_IPSEC and
INET6 in the same system.

Obtained from: KAME + openbsd
Supported by: Vernier Networks