Having a pointer of an interface in a mbuf isn't safe if we remove big
kernel locks; an interface object (ifnet) can be destroyed anytime in any
packet processing and accessing such object via a pointer is racy. Instead
we have to get an object from the interface collection (ifindex2ifnet) via
an interface index (if_index) that is stored to a mbuf instead of an
pointer.
The change provides two APIs: m_{get,put}_rcvif_psref that use psref(9)
for sleep-able critical sections and m_{get,put}_rcvif that use
pserialize(9) for other critical sections. The change also adds another
API called m_get_rcvif_NOMPSAFE, that is NOT MP-safe and for transition
moratorium, i.e., it is intended to be used for places where are not
planned to be MP-ified soon.
The change adds some overhead due to psref to performance sensitive paths,
however the overhead is not serious, 2% down at worst.
Proposed on tech-kern and tech-net.
repository by christos was part 1). netipsec should now be back as it
was on 2003-09-11, with some very minor changes:
1) Some residual platform-dependent code was moved from ipsec.h to
ipsec_osdep.h; without this, IPSEC_ASSERT() was multiply defined. ipsec.h
now includes ipsec_osdep.h
2) itojun's renaming of netipsec/files.ipsec to netipsec/files.netipsec has
been left in place (it's arguable which name is less confusing but the
rename is pretty harmless).
3) Some #endif TOKEN has been replaced by #endif /* TOKEN */; #endif TOKEN
is invalid and GCC 3 won't compile it.
An i386 kernel with "options FAST_IPSEC" and "options OPENCRYPTO" now
gets through "make depend" but fails to build with errors in ip_input.c.
But it's better than it was (thank heaven for small favors).
Fast-IPsec is a rework of the OpenBSD and KAME IPsec code, using the
OpenCryptoFramework (and thus hardware crypto accelerators) and
numerous detailed performance improvements.
This import is (aside from SPL-level names) the FreeBSD source,
imported ``as-is'' as a historical snapshot, for future maintenance
and comparison against the FreeBSD source. For now, several minor
kernel-API differences are hidden by macros a shim file, ipsec_osdep.h,
which (aside from SPL names) can be targeted at either NetBSD or FreeBSD.
