Sanity check of SACK holes on retransmissions

[rscheff]

Summary

Adding a few KASSERT() to validate sanity of sack holes, and bail out if sack hole is inconsistent to avoid panicing non-invariant builds.

[• hselasky]

sys/netinet/tcp_sack.c

968

Don't you need to use the SEQ macros for this?

[glebius]

sys/netinet/tcp_sack.c

976

Maybe print something in non-debug case?

[rscheff]

• use SEQ_LT / GEQ macros

[rscheff]

• add logging

[tuexen]

sys/netinet/tcp_sack.c

976

When printing them using %d, don't some of them show up as negative numbers? Would %u make more sense?

[rscheff]

• use SEQ_LT / GEQ macros
• add logging

[rscheff]

• change format to %u

[rscheff]

Thanks. Commiting with 1 week MFC...