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Diffstat (limited to 'sys/netinet/tcp_input.c')
-rw-r--r--sys/netinet/tcp_input.c48
1 files changed, 28 insertions, 20 deletions
diff --git a/sys/netinet/tcp_input.c b/sys/netinet/tcp_input.c
index 7c032e13f37a..de428ae1af6f 100644
--- a/sys/netinet/tcp_input.c
+++ b/sys/netinet/tcp_input.c
@@ -621,6 +621,7 @@ tcp_input_with_port(struct mbuf **mp, int *offp, int proto, uint16_t port)
#endif /* INET6 */
struct tcpopt to; /* options in this segment */
char *s = NULL; /* address and port logging */
+ bool closed_port = false; /* segment is hitting a closed port */
NET_EPOCH_ASSERT();
@@ -907,7 +908,8 @@ findpcb:
log(LOG_INFO, "%s; %s: Connection attempt "
"to closed port\n", s, __func__);
}
- rstreason = BANDLIM_RST_CLOSEDPORT;
+ rstreason = BANDLIM_TCP_RST;
+ closed_port = true;
goto dropwithreset;
}
INP_LOCK_ASSERT(inp);
@@ -998,12 +1000,14 @@ findpcb:
* down or it is in the CLOSED state. Either way we drop the
* segment and send an appropriate response.
*/
- rstreason = BANDLIM_RST_CLOSEDPORT;
+ rstreason = BANDLIM_TCP_RST;
+ closed_port = true;
goto dropwithreset;
}
if ((tp->t_port != port) && (tp->t_state > TCPS_LISTEN)) {
- rstreason = BANDLIM_RST_CLOSEDPORT;
+ rstreason = BANDLIM_TCP_RST;
+ closed_port = true;
goto dropwithreset;
}
@@ -1055,6 +1059,8 @@ findpcb:
* socket appended to the listen queue in SYN_RECEIVED state.
*/
if ((thflags & (TH_RST|TH_ACK|TH_SYN)) == TH_ACK) {
+ int result;
+
/*
* Parse the TCP options here because
* syncookies need access to the reflected
@@ -1064,8 +1070,8 @@ findpcb:
/*
* NB: syncache_expand() doesn't unlock inp.
*/
- rstreason = syncache_expand(&inc, &to, th, &so, m, port);
- if (rstreason < 0) {
+ result = syncache_expand(&inc, &to, th, &so, m, port);
+ if (result < 0) {
/*
* A failing TCP MD5 signature comparison
* must result in the segment being dropped
@@ -1073,7 +1079,7 @@ findpcb:
* to the sender.
*/
goto dropunlock;
- } else if (rstreason == 0) {
+ } else if (result == 0) {
/*
* No syncache entry, or ACK was not for our
* SYN/ACK. Do our protection against double
@@ -1092,7 +1098,7 @@ findpcb:
* of the failure cause.
*/
INP_WUNLOCK(inp);
- rstreason = BANDLIM_RST_OPENPORT;
+ rstreason = BANDLIM_TCP_RST;
lookupflag &= ~INPLOOKUP_WILDCARD;
goto findpcb;
}
@@ -1183,7 +1189,7 @@ tfo_socket_result:
s, __func__);
syncache_badack(&inc, port); /* XXX: Not needed! */
TCPSTAT_INC(tcps_badsyn);
- rstreason = BANDLIM_RST_OPENPORT;
+ rstreason = BANDLIM_TCP_RST;
goto dropwithreset;
}
/*
@@ -1259,7 +1265,7 @@ tfo_socket_result:
"Connection attempt to deprecated "
"IPv6 address rejected\n",
s, __func__);
- rstreason = BANDLIM_RST_OPENPORT;
+ rstreason = BANDLIM_TCP_RST;
goto dropwithreset;
}
}
@@ -1380,9 +1386,10 @@ dropwithreset:
* When blackholing do not respond with a RST but
* completely ignore the segment and drop it.
*/
- if (((rstreason == BANDLIM_RST_OPENPORT && V_blackhole == 3) ||
- (rstreason == BANDLIM_RST_CLOSEDPORT &&
- ((V_blackhole == 1 && (thflags & TH_SYN)) || V_blackhole > 1))) &&
+ if (rstreason == BANDLIM_TCP_RST &&
+ ((!closed_port && V_blackhole == 3) ||
+ (closed_port &&
+ ((V_blackhole == 1 && (thflags & TH_SYN)) || V_blackhole > 1))) &&
(V_blackhole_local || (
#ifdef INET6
isipv6 ? !in6_localip(&ip6->ip6_src) :
@@ -1515,7 +1522,9 @@ tcp_do_segment(struct tcpcb *tp, struct mbuf *m, struct tcphdr *th,
struct tcpopt to;
int tfo_syn;
u_int maxseg = 0;
+ bool no_data;
+ no_data = (tlen == 0);
thflags = tcp_get_flags(th);
tp->sackhint.last_sack_ack = 0;
sack_changed = SACK_NOCHANGE;
@@ -1754,7 +1763,7 @@ tcp_do_segment(struct tcpcb *tp, struct mbuf *m, struct tcphdr *th,
tp->ts_recent = to.to_tsval;
}
- if (tlen == 0) {
+ if (no_data) {
if (SEQ_GT(th->th_ack, tp->snd_una) &&
SEQ_LEQ(th->th_ack, tp->snd_max) &&
!IN_RECOVERY(tp->t_flags) &&
@@ -1963,7 +1972,7 @@ tcp_do_segment(struct tcpcb *tp, struct mbuf *m, struct tcphdr *th,
if ((thflags & TH_ACK) &&
(SEQ_LEQ(th->th_ack, tp->snd_una) ||
SEQ_GT(th->th_ack, tp->snd_max))) {
- rstreason = BANDLIM_RST_OPENPORT;
+ rstreason = BANDLIM_TCP_RST;
tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
goto dropwithreset;
}
@@ -1976,7 +1985,7 @@ tcp_do_segment(struct tcpcb *tp, struct mbuf *m, struct tcphdr *th,
* FIN, or a RST.
*/
if ((thflags & (TH_SYN|TH_ACK)) == (TH_SYN|TH_ACK)) {
- rstreason = BANDLIM_RST_OPENPORT;
+ rstreason = BANDLIM_TCP_RST;
tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
goto dropwithreset;
} else if (thflags & TH_SYN) {
@@ -2244,7 +2253,7 @@ tcp_do_segment(struct tcpcb *tp, struct mbuf *m, struct tcphdr *th,
* for the "LAND" DoS attack.
*/
if (tp->t_state == TCPS_SYN_RECEIVED && SEQ_LT(th->th_seq, tp->irs)) {
- rstreason = BANDLIM_RST_OPENPORT;
+ rstreason = BANDLIM_TCP_RST;
tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
goto dropwithreset;
}
@@ -2557,7 +2566,7 @@ tcp_do_segment(struct tcpcb *tp, struct mbuf *m, struct tcphdr *th,
if (SEQ_LEQ(th->th_ack, tp->snd_una)) {
maxseg = tcp_maxseg(tp);
- if (tlen == 0 &&
+ if (no_data &&
(tiwin == tp->snd_wnd ||
(tp->t_flags & TF_SACK_PERMIT))) {
/*
@@ -3113,8 +3122,7 @@ step6:
(tp->snd_wl1 == th->th_seq && (SEQ_LT(tp->snd_wl2, th->th_ack) ||
(tp->snd_wl2 == th->th_ack && tiwin > tp->snd_wnd))))) {
/* keep track of pure window updates */
- if (tlen == 0 &&
- tp->snd_wl2 == th->th_ack && tiwin > tp->snd_wnd)
+ if (no_data && tp->snd_wl2 == th->th_ack && tiwin > tp->snd_wnd)
TCPSTAT_INC(tcps_rcvwinupd);
tp->snd_wnd = tiwin;
tp->snd_wl1 = th->th_seq;
@@ -3424,7 +3432,7 @@ dropafterack:
if (tp->t_state == TCPS_SYN_RECEIVED && (thflags & TH_ACK) &&
(SEQ_GT(tp->snd_una, th->th_ack) ||
SEQ_GT(th->th_ack, tp->snd_max)) ) {
- rstreason = BANDLIM_RST_OPENPORT;
+ rstreason = BANDLIM_TCP_RST;
tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
goto dropwithreset;
}
generated by cgit v1.2.3 (git 2.25.1) at 2025-07-23 14:57:25 +0000