diff --git a/sys/netinet/tcp_syncache.c b/sys/netinet/tcp_syncache.c --- a/sys/netinet/tcp_syncache.c +++ b/sys/netinet/tcp_syncache.c @@ -1260,6 +1260,35 @@ return (-1); /* Do not send RST */ } } + + /* + * SEG.ACK validation: + * SEG.ACK must match our initial send sequence number + 1. + */ + if (th->th_ack != sc->sc_iss + 1) { + SCH_UNLOCK(sch); + if ((s = tcp_log_addrs(inc, th, NULL, NULL))) + log(LOG_DEBUG, "%s; %s: ACK %u != ISS+1 %u, " + "segment rejected\n", + s, __func__, th->th_ack, sc->sc_iss + 1); + goto failed; + } + + /* + * SEG.SEQ validation: + * The SEG.SEQ must be in the window starting at our + * initial receive sequence number + 1. + */ + if (SEQ_LEQ(th->th_seq, sc->sc_irs) || + SEQ_GT(th->th_seq, sc->sc_irs + sc->sc_wnd)) { + SCH_UNLOCK(sch); + if ((s = tcp_log_addrs(inc, th, NULL, NULL))) + log(LOG_DEBUG, "%s; %s: SEQ %u != IRS+1 %u, " + "segment rejected\n", + s, __func__, th->th_seq, sc->sc_irs + 1); + goto failed; + } + TAILQ_REMOVE(&sch->sch_bucket, sc, sc_hash); sch->sch_length--; #ifdef TCP_OFFLOAD @@ -1272,29 +1301,6 @@ SCH_UNLOCK(sch); } - /* - * Segment validation: - * ACK must match our initial sequence number + 1 (the SYN|ACK). - */ - if (th->th_ack != sc->sc_iss + 1) { - if ((s = tcp_log_addrs(inc, th, NULL, NULL))) - log(LOG_DEBUG, "%s; %s: ACK %u != ISS+1 %u, segment " - "rejected\n", s, __func__, th->th_ack, sc->sc_iss); - goto failed; - } - - /* - * The SEQ must fall in the window starting at the received - * initial receive sequence number + 1 (the SYN). - */ - if (SEQ_LEQ(th->th_seq, sc->sc_irs) || - SEQ_GT(th->th_seq, sc->sc_irs + sc->sc_wnd)) { - if ((s = tcp_log_addrs(inc, th, NULL, NULL))) - log(LOG_DEBUG, "%s; %s: SEQ %u != IRS+1 %u, segment " - "rejected\n", s, __func__, th->th_seq, sc->sc_irs); - goto failed; - } - *lsop = syncache_socket(sc, *lsop, m); if (__predict_false(*lsop == NULL)) {