sid/ssn values are reported multiple times in one FORWARD-TSN Chunk

[TheAomx]

When there are multiple outstanding DATA-Chunks of one fragmented ordered user message the current FreeBSD-Kernel reports each outstanding DATA-Chunk sid/ssn value in an sent FORWARD-TSN Chunk if the fragmented ordered user message is abandoned.

Ideally it should only report the sid/ssn value once in the FORWARD-TSN Chunk, because if there are multiple fragmented DATA-Chunks outstanding the FORWARD-TSN Chunk gets filled with duplicate sid/ssn values.

See the following test cases for more details:

• https://github.com/nplab/PR_SCTP_Testsuite/blob/master/forward-tsn/sender-side-implementation/ttl-policy/sender-side-implementation-1.pkt
• https://github.com/nplab/PR_SCTP_Testsuite/blob/master/forward-tsn/sender-side-implementation/limited-retransmission/sender-side-implementation-1.pkt
• https://github.com/nplab/PR_SCTP_Testsuite/blob/master/i-forward-tsn/sender-side-implementation/ttl-policy/sender-side-implementation-1.pkt