MFC r257804:

Get rid of the artification limitation enforced by
SCTP_AUTH_RANDOM_SIZE_MAX.
This was suggested by Andrew Galante.
MFC r258221:

Cleanups which result in fixes which have been made upstream
and where partially suggested by Andrew Galante.
There is no functional change in FreeBSD.
MFC r258224:

When determining if an address belongs to an stcb, take the address
family into account for wildcard bound endpoints.
MFC r258228:

Remove a stray write operation.
MFC r258235:

Use SCTP_PR_SCTP_TTL when the user provides a positive
timetolive in sctp_sendmsg().
MFC r258574 from rodrigc@

Only initialize some mutexes for the default VNET.

In r208160, sctp_it_ctl was made a global variable, across all VNETs.
However, sctp_init() is called for every VNET that is created.  This results
in the same global mutexes which are part of sctp_it_ctl being initialized.  This can result
in crashes if many jails are created.

To reproduce the problem:
  (1)  Take a GENERIC kernel config, and add options for: VIMAGE, WITNESS,
       INVARIANTS.
  (2)  Run this command in a loop:
       jail -l -u root -c path=/ name=foo persist vnet && jexec foo ifconfig lo0 127.0.0.1/8 && jail -r foo

       (see http://lists.freebsd.org/pipermail/freebsd-current/2010-November/021280.html )

Witness will warn about the same mutex being initialized.

Fix the problem by only initializing these mutexes in the default VNET.
MFC r258765:

In
http://svnweb.freebsd.org/changeset/base/258221
I introduced a bug which initialized global locks
whenever the SCTP stack initialized. This was fixed in
http://svnweb.freebsd.org/changeset/base/258574
by rodrigc@. He just initialized the locks for
the default vnet. This fix reverts to the old
behaviour before r258221, which explicitly makes
sure it is only called once, because this works also on
other platforms.