Add IPv6 transport for bsnmp.

This patch adds a new table begemotSnmpdTransInetTable that uses the
InetAddressType textual convention and can be used to create listening
ports for IPv4, IPv6, zoned IPv6 and based on DNS names. It also supports
future extension beyond UDP by adding a protocol identifier to the table
index. In order to support this gensnmptree had to be modified.

Submitted by: harti
MFC after: 1 month
Relnotes: yes
Differential Revision: https://reviews.freebsd.org/D16654

Use calloc instead of malloc + memset(.., 0, ..)

MFC after: 3 days

lsock_init_port: address issues with initializing sockaddr_un object

- Use strlcpy to ensure p->name doesn't overflow sa.sun_path [*].
- Use SUN_LEN(..) instead of spelling out calculation longhand (inspired
by comment by jmallett).

Tested with: dgram and stream support with both bsnmpwalk and snmpwalk

MFC after: 1 week
Reported by: Coverity
CID: 1006825

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(..).

MFC after: 3 weeks
Obtained from: Isilon OneFS (^/onefs/branches/BR_8_0_0_DEV@r507595)
Submitted by: Thor Steingrimsson <thor.steingrimsson@isilon.com>
Sponsored by: Dell EMC Isilon

style(9): clean up trailing whitespace

MFC after: 3 weeks

Refactor transport sources a bit to facilitate changes coming down pipeline

Add recv callback to transport layer to better facilitate code reuse and
readability and for symmetry with send callback. Move recv_dgram and
recv_stream to udp_recv and lsock_recv, respectively, and make the
beforementioned functions recv callbacks for the udp and lsock transports,
respectively.

Consolidate the check_priv* functions in their relevant trans*.c source to
limit scope/use.

Note: this code is roughly based content from the submitter, although this
was modified to be more of a direct move from snmpd/main.c to the trans_*.c
sources, and to reduce unnecessary static function declarations.

MFC after: 2 weeks
Submitted by: Thor Steingrimsson <thor.steingrimsson@isilon.com>
Sponsored by: Dell EMC Isilon

Fix style(9)

- Sort #includes
- Delete trailing whitespace

No functional change

MFC after: 3 days

The first part of check_priv() function, that attempts to obtain creds
from the control message, actually never worked. This means check_priv()
didn't work for local dgram sockets.

The SCM_CREDS control messages is received only in two cases:

1) If we did setsockopt(LOCAL_CREDS) on our socket, and in this case
the message is struct sockcred.
2) If sender did supplied SCM_CREDS control message in his sendmsg()
syscall. In this case the message is struct cmsgcred.

We can't rely on 2), so we will use 1) for dgram sockets. For stream
sockets it is more reliable to obtain accept-time credentials, since
SCM_CREDS control message is attached only on first read. Thus:

o Do setsockopt(LOCAL_CREDS) on local dgram sockets.
o Split check_priv() into check_priv_stream() and check_priv_dgram(),
and call them from recv_stream() and recv_dgram() respectively.
o Don't provide space for SCM_CREDS control message in recv_stream().
o Provide space for SCM_CREDS control message in recv_dgram(), but there
is no need to initialize anything in it.
o In recv_dgram() do not blindly expect that first message is SCM_CREDS,
instead use correct search cycle through control messages.

In bsnmpd(1) add support for SNMPv3 message processing model, including message authentication, packet encryption & view-based access control (RFC 3412, 3414, 3415).

Sponsored by: The FreeBSD Foundation
Reviewed by: philip@ (mostly)
Approved by: philip@

A new jail(8) with a configuration file, to replace the work currently done
by /etc/rc.d/jail.

Create the altix project branch. The altix project will add support
for the SGI Altix 350 to FreeBSD/ia64. The hardware used for porting
is a two-module system, consisting of a base compute module and a
CPU expansion module. SGI's NUMAFlex architecture can be an excellent
platform to test CPU affinity and NUMA-aware features in FreeBSD.

- Import the HEAD csup code which is the basis for the cvsmode work.

Virgin import of bsnmpd 1.8

Virgin import of bsnmpd 1.7

Import of bsnmpd 1.6

Virgin import of bsnmpd 1.5a