Add support for ABORT action in ipfw

[tuexen]

Summary

This patch adds support for an action for ipfw to send an SCTP packet containing an ABORT chunk. This is similar to the TCP case, where a TCP reset segment is sent.

There is one limitation: When sending an ABORT in response to a packet it should be tested if there is no ABORT in the incoming packet. Currently it is only checked if the first chunk is an ABORT chunk to avoid parsing through the whole packet.

Test Plan

It was tested with packets containing INIT chunks, non-INIT chunks, packets containing no chunks. IPv4 and IPv6 was used. Thanks to Timo Völker for creating some test scripts to test this.

[bcr]

OK from manpages, you just need to bump the .Dd to the date of the actual commit.

[ae]

I'm not familiar with SCTP, from other side seems good to me, except some style issues.

sys/netpfil/ipfw/ip_fw2.c

480 ↗

(On Diff #35765)

It seems this function can be made static.

484 ↗

(On Diff #35765)

This line should be moved below according to style(9) :)

[tuexen]

Address comments made by bcr@ and ae@.

[tuexen]

Thanks to bcr@ and ae@ for reviewing this patch so fast!

Best regards
Michael