MFC r312331:
r312331 (by glebius):

Fix regression from r310655, which broke operation of bsnmpd if it is bound
to a non-wildcard address. As documented in ip(4), doing sendmsg(2) with
IP_SENDSRCADDR on a socket that is bound to non-wildcard address is
completely different to using this control message on a wildcard one.

A fix is to add a bool to mark whether we did setsockopt(IP_RECVDSTADDR)
on the socket, and use IP_SENDSRCADDR control message only if we did.

While here, garbage collect absolutely useless udp_recv() function that
establishes some structures on stack to never use them later.

MFC r310655:

Fix bsnmpd sending/receiving with multi-homed configurations or INADDR_ANY used
as the listening address in snmpd_input(..)

Stash the IPv4 address of the receiver via the recv(..) callback and use it in
the send(..) callback for the transport by specifying IP_SENDSRCADDR for the
control message type.

Add sendmsg logic to the UDP transport's send(..) callback and use the
respective send(..) callback for the transport instead of calling sendto in
snmpd_input(..).

Obtained from: Isilon OneFS (^/onefs/branches/BR_8_0_0_DEV@r507595)

MFstable/11 r310901:

MFC r310648:

style(9): clean up trailing whitespace

Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

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

This commit was generated by cvs2svn to compensate for changes in r133211,
which included commits to RCS files with non-trunk default branches.

Virgin import of bsnmpd 1.7

Virgin import of bsnmpd 1.5a