This is untested, since the kernel doesn't support it yet...

Please note that packetdrill currently does not support
getsockopt() for non int values.

Current limitations:
* Chunk parameters are not yet supported.
* Error causes are not yet supported.
* Chunks can't be bundled with COOKIE-ECHO chunks.
* Chunk flags are not supported.
* Chunk lengths are not supported.
* Gap reports and duplicate TSNs are not supported for SACK chunks.
* SCTP related ICMP messages are not supported.
This version is only tested in a limited way, only on FreeBSD and
only in local mode.

This commit adds support for the following SCTP socket options:
* SCTP_RTOINFO
* SCTP_INITMSG
* SCTP_NODELAY
* SCTP_MAXSEG
* SCTP_DELAYED_SACK
* SCTP_MAX_BURST

Tested on Linux and FreeBSD. NetBSD and OpenBSD doen't support
SCTP and should not be affected.

Signed-off-by: Michael Tuexen <tuexen@fh-muenster.de>

This patch fixes two issues:
* It only makes sense to report errno if a system call has actually
  failed.
* You can't call strerror() two times in printf(), since it might
  use a single static buffer.

Signed-off-by: Michael Tuexen <tuexen@fh-muenster.de>

To allow hexadecimal integers with the most significant bit set to be
passed as system call parameters, we need to broaden the set of values
acceptable to get_s32() to include u32.

If this proves confusing, then at some point in the future we could
rename this to be get_32() or something.

Change-Id: I416f80f8c135306c6b64de8b700186d0b9a005c7

Initial commit for the packetdrill network stack testing tool:

  https://code.google.com/p/packetdrill/



Signed-off-by: Neal Cardwell <ncardwell@google.com>