dtrace: allow NULL interface pointer for ifinfo_t translator

This is similar to other translators and will be used in static
probes where the interface is not known.

Reviewed by: markj
MFC after: 1 week
Sponsored by: Netflix, Inc.
Differential Revision: https://reviews.freebsd.org/D43728

Remove $FreeBSD$: two-line .h pattern

Remove /^\s*\*\n \*\s+\$FreeBSD\$$\n/

Add a dtrace provider for UDP-Lite.

The dtrace provider for UDP-Lite is modeled after the UDP provider.
This fixes the bug that UDP-Lite packets were triggering the UDP
provider.
Thanks to dteske@ for providing the dwatch module.

Reviewed by: dteske@, markj@, rrs@
Relnotes: yes
Differential Revision: https://reviews.freebsd.org/D16377

The IP, TCP, and UDP provider report IP addresses as strings.
In some cases, the required information is not available and the
UDP provider reported an empty string in this case and the IP
and TCP provider reported a NULL pointer.

This patch changes the value provided in this case to the string
"<unknown>". This make the behaviour consistent and in-line with
the behaviour of Solaris.

Reviewed by: markj@, dteske@, gnn@
Differential Revision: https://reviews.freebsd.org/D15855

Use tabs in io.d, fix alignment issues, remove extraneous newlines

Add an mbuf to ipinfo_t translator to finish cleanup of mbuf passing to TCP probes.

Reviewed by: markj
MFC after: 2 weeks
Sponsored by: DARPA, AFRL
Differential Revision: https://reviews.freebsd.org/D9401

Convert ipv4_flags and ipv4_offset fields into host byte order.
Also save only high bits in the ipv4_flags, because it is defined
as uint8_t. So now it will show DF and MF flags as 0x40 and 0x20.

Reviewed by: markj@
MFC after: 1 week

Remove an unneeded typedef of ip6_t from the DTrace ip provider library.
It causes an error when ipfilter is enabled, since ipl.ko contains an
identical typedef.

PR: 203092
MFC after: 1 week

- Use an explicit "depends_on module kernel" guard in DTrace libraries that
reference types defined in the kernel. Otherwise dtrace(1) expects to find
CTF definitions for all referenced types, which is not very reasonable
when it is being used in a build environment. This was previously worked
around by adding "-x nolibs" to dtrace -h or -G invocations, but as of
r283025, dtrace(1) actually handles dependencies properly, so this is no
longer necessary.
- Remove "pragma ident" directives from DTrace libraries, as they're being
phased out upstream as well.

Submitted by: Krister Johansen <Krister.Johansen@isilon.com> [1]
MFC after: 1 week
Sponsored by: EMC / Isilon Storage Division

Bind ip/tcp/udp provider translators and symbols to the same versions as in
illumos, rather than using "1.0" everywhere.

Some of the translators use D functions that are not present in version
1.0 (e.g. inet_ntoa()) which can result in libdtrace crashing when running
scripts that restrict themselves to version 1.0
(e.g. with "-x version=1.0").

MFC after: 1 week

Implement the ip, tcp, and udp DTrace providers. The probe definitions use
dynamic translation so that their arguments match the definitions for
these providers in Solaris and illumos. Thus, existing scripts for these
providers should work unmodified on FreeBSD.

Tested by: gnn, hiren
MFC after: 1 month