diff options
authorHarald Welte <>2005-05-04 07:34:37 +0000
committerHarald Welte <>2005-05-04 07:34:37 +0000
commit38ed421276ff0312965c96754b4bc01d0e4f0679 (patch)
parente556800cf137e49a47cf1ac889c613f5d33cfe3b (diff)
include FIN bit in mask of "--syn" bits
2 files changed, 3 insertions, 3 deletions
diff --git a/extensions/libipt_tcp.c b/extensions/libipt_tcp.c
index 6f9ea06a..f8ed249a 100644
--- a/extensions/libipt_tcp.c
+++ b/extensions/libipt_tcp.c
@@ -205,7 +205,7 @@ parse(int c, char **argv, int invert, unsigned int *flags,
"Only one of `--syn' or `--tcp-flags' "
" allowed");
- parse_tcp_flags(tcpinfo, "SYN,RST,ACK", "SYN", invert);
+ parse_tcp_flags(tcpinfo, "SYN,RST,ACK,FIN", "SYN", invert);
*flags |= TCP_FLAGS;
diff --git a/extensions/ b/extensions/
index 48a068fa..e1f44057 100644
--- a/extensions/
+++ b/extensions/
@@ -32,12 +32,12 @@ will only match packets with the SYN flag set, and the ACK, FIN and
RST flags unset.
.B "[!] --syn"
-Only match TCP packets with the SYN bit set and the ACK and RST bits
+Only match TCP packets with the SYN bit set and the ACK,RST and FIN bits
cleared. Such packets are used to request TCP connection initiation;
for example, blocking such packets coming in an interface will prevent
incoming TCP connections, but outgoing TCP connections will be
-It is equivalent to \fB--tcp-flags SYN,RST,ACK SYN\fP.
+It is equivalent to \fB--tcp-flags SYN,RST,ACK,FIN SYN\fP.
If the "!" flag precedes the "--syn", the sense of the
option is inverted.