On Wednesday 2023-04-12 18:44, Matthieu Baerts wrote: > >> Makes me wonder why MPTCP got 262 instead of just 257. > >Just in case a uint8 is used somewhere, we fallback to TCP (6): > > IPPROTO_MPTCP & 0xff = IPPROTO_TCP > >Instead of IPPROTO_ICMP (1). > >We did that to be on the safe side, not knowing all the different >userspace implementations :) Silent failure? That's terrible. int IPPROTO_MPTCP = 257; socket(AF_INET, SOCK_STREAM, (uint8_t)IPPROTO_MPTCP); on the other hand would immediately fail with EPROTONOSUPP and make hidden uint8 truncation readily visible.
