A 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.
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 this implemened via IPsec methods.
o TCP_SIGNATURE support is 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 speedup lookups in SADB.
- SADB now uses rmlock to protect access, and concurrent threads
can do SA lookups in the same time.
- many PF_KEY messages handlers were reworked to reflect changes
in SADB.
o ipsecrequest and secpolicy structures were cardinally changed to
avoid locking protection for ipsecrequest. Also 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
the 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. Also proper SA locking added into xform
code.
o xform code also was 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.