aboutsummaryrefslogtreecommitdiff
diff options
context:
space:
mode:
-rw-r--r--net/ipv4/netfilter/ip_conntrack_proto_tcp.c29
-rw-r--r--net/netfilter/nf_conntrack_proto_tcp.c29
2 files changed, 40 insertions, 18 deletions
diff --git a/net/ipv4/netfilter/ip_conntrack_proto_tcp.c b/net/ipv4/netfilter/ip_conntrack_proto_tcp.c
index 62598167677..aeb7353d477 100644
--- a/net/ipv4/netfilter/ip_conntrack_proto_tcp.c
+++ b/net/ipv4/netfilter/ip_conntrack_proto_tcp.c
@@ -272,9 +272,9 @@ static const enum tcp_conntrack tcp_conntracks[2][6][TCP_CONNTRACK_MAX] = {
* sCL -> sCL
*/
/* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sLI */
-/*ack*/ { sIV, sIV, sSR, sES, sCW, sCW, sTW, sTW, sCL, sIV },
+/*ack*/ { sIV, sIG, sSR, sES, sCW, sCW, sTW, sTW, sCL, sIV },
/*
- * sSS -> sIV Might be a half-open connection.
+ * sSS -> sIG Might be a half-open connection.
* sSR -> sSR Might answer late resent SYN.
* sES -> sES :-)
* sFW -> sCW Normal close request answered by ACK.
@@ -917,8 +917,12 @@ static int tcp_packet(struct ip_conntrack *conntrack,
switch (new_state) {
case TCP_CONNTRACK_IGNORE:
- /* Either SYN in ORIGINAL
- * or SYN/ACK in REPLY. */
+ /* Ignored packets:
+ *
+ * a) SYN in ORIGINAL
+ * b) SYN/ACK in REPLY
+ * c) ACK in reply direction after initial SYN in original.
+ */
if (index == TCP_SYNACK_SET
&& conntrack->proto.tcp.last_index == TCP_SYN_SET
&& conntrack->proto.tcp.last_dir != dir
@@ -985,13 +989,20 @@ static int tcp_packet(struct ip_conntrack *conntrack,
}
case TCP_CONNTRACK_CLOSE:
if (index == TCP_RST_SET
- && test_bit(IPS_SEEN_REPLY_BIT, &conntrack->status)
- && conntrack->proto.tcp.last_index == TCP_SYN_SET
+ && ((test_bit(IPS_SEEN_REPLY_BIT, &conntrack->status)
+ && conntrack->proto.tcp.last_index == TCP_SYN_SET)
+ || (!test_bit(IPS_ASSURED_BIT, &conntrack->status)
+ && conntrack->proto.tcp.last_index == TCP_ACK_SET))
&& ntohl(th->ack_seq) == conntrack->proto.tcp.last_end) {
- /* RST sent to invalid SYN we had let trough
- * SYN was in window then, tear down connection.
+ /* RST sent to invalid SYN or ACK we had let trough
+ * at a) and c) above:
+ *
+ * a) SYN was in window then
+ * c) we hold a half-open connection.
+ *
+ * Delete our connection entry.
* We skip window checking, because packet might ACK
- * segments we ignored in the SYN. */
+ * segments we ignored. */
goto in_window;
}
/* Just fall trough */
diff --git a/net/netfilter/nf_conntrack_proto_tcp.c b/net/netfilter/nf_conntrack_proto_tcp.c
index 5a6fcf349bd..6035633d822 100644
--- a/net/netfilter/nf_conntrack_proto_tcp.c
+++ b/net/netfilter/nf_conntrack_proto_tcp.c
@@ -280,9 +280,9 @@ static enum tcp_conntrack tcp_conntracks[2][6][TCP_CONNTRACK_MAX] = {
* sCL -> sCL
*/
/* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sLI */
-/*ack*/ { sIV, sIV, sSR, sES, sCW, sCW, sTW, sTW, sCL, sIV },
+/*ack*/ { sIV, sIG, sSR, sES, sCW, sCW, sTW, sTW, sCL, sIV },
/*
- * sSS -> sIV Might be a half-open connection.
+ * sSS -> sIG Might be a half-open connection.
* sSR -> sSR Might answer late resent SYN.
* sES -> sES :-)
* sFW -> sCW Normal close request answered by ACK.
@@ -912,8 +912,12 @@ static int tcp_packet(struct nf_conn *conntrack,
switch (new_state) {
case TCP_CONNTRACK_IGNORE:
- /* Either SYN in ORIGINAL
- * or SYN/ACK in REPLY. */
+ /* Ignored packets:
+ *
+ * a) SYN in ORIGINAL
+ * b) SYN/ACK in REPLY
+ * c) ACK in reply direction after initial SYN in original.
+ */
if (index == TCP_SYNACK_SET
&& conntrack->proto.tcp.last_index == TCP_SYN_SET
&& conntrack->proto.tcp.last_dir != dir
@@ -979,13 +983,20 @@ static int tcp_packet(struct nf_conn *conntrack,
}
case TCP_CONNTRACK_CLOSE:
if (index == TCP_RST_SET
- && test_bit(IPS_SEEN_REPLY_BIT, &conntrack->status)
- && conntrack->proto.tcp.last_index == TCP_SYN_SET
+ && ((test_bit(IPS_SEEN_REPLY_BIT, &conntrack->status)
+ && conntrack->proto.tcp.last_index == TCP_SYN_SET)
+ || (!test_bit(IPS_ASSURED_BIT, &conntrack->status)
+ && conntrack->proto.tcp.last_index == TCP_ACK_SET))
&& ntohl(th->ack_seq) == conntrack->proto.tcp.last_end) {
- /* RST sent to invalid SYN we had let trough
- * SYN was in window then, tear down connection.
+ /* RST sent to invalid SYN or ACK we had let trough
+ * at a) and c) above:
+ *
+ * a) SYN was in window then
+ * c) we hold a half-open connection.
+ *
+ * Delete our connection entry.
* We skip window checking, because packet might ACK
- * segments we ignored in the SYN. */
+ * segments we ignored. */
goto in_window;
}
/* Just fall trough */