tcp_dooptions(struct tcpcb *tp, u_char *cp, int cnt, struct tcpiphdr *ti) { uint16_t mss; int opt, optlen; DEBUG_CALL("tcp_dooptions"); DEBUG_ARGS((dfd," tp = %lx cnt=%i \n", (long )tp, cnt)); for (; cnt > 0; cnt -= optlen, cp += optlen) { opt = cp[0]; if (opt == TCPOPT_EOL) break; if (opt == TCPOPT_NOP) optlen = 1; else { optlen = cp[1]; if (optlen <= 0) break; } switch (opt) { default: continue; case TCPOPT_MAXSEG: if (optlen != TCPOLEN_MAXSEG) continue; if (!(ti->ti_flags & TH_SYN)) continue; memcpy((char *) &mss, (char *) cp + 2, sizeof(mss)); NTOHS(mss); (void) tcp_mss(tp, mss); /* sets t_maxseg */ break; } } }