Fix checksum computation for packets with IP-level options. This only affects the FreeBSD kernel stack.
Fix checksum computation for packets with IP-level options.
This only affects the FreeBSD kernel stack.

sctplab/usrsctp,sctplab/usrsctp,CoolmanCZ/usrsctp,sctplab/usrsctp,weinrank/usrsctp,CoolmanCZ/usrsctp,CoolmanCZ/usrsctp,CoolmanCZ/usrsctp,weinrank/usrsctp,weinrank/usrsctp