Specify non-unicast source addresses

[tuexen]

This is necessary for some tests like sctp-fh-o-5-3-5.

[tuexen]

As suggested by Neal, something like

// Create a non-blocking 1-to-1 style listening socket
+0.0 socket(..., SOCK_STREAM, IPPROTO_SCTP) = 3
+0.0 fcntl(3, F_GETFL) = 0x2 (flags O_RDWR)
+0.0 fcntl(3, F_SETFL, O_RDWR|O_NONBLOCK) = 0
+0.0 bind(3, ..., ...) = 0
+0.0 listen(3, 1) = 0
// Get a valid cookie
+0.0 < sctp: INIT[flgs=0, tag=1, a_rwnd=1500, os=1, is=1, tsn=1]
+0.0 > sctp: INIT_ACK[flgs=0, tag=2, a_rwnd=..., os=..., is=..., tsn=1, ...]
// Need to send the following from a non-unicast address
+0.0 < 224.0.0.0 > 192.168.0.1 sctp: COOKIE_ECHO[flgs=0, len=..., val=...]
// Ensure that the message has been discarded
+0.1 accept(3, ..., ...) = -1 EAGAIN (Resource temporarily unavailable)
+0.0 close(3) = 0

should work.