path: root/libiptc/libip4tc.c
diff options
authorStefan Tomanek <>2011-03-08 22:42:51 +0100
committerJan Engelhardt <>2011-03-08 23:12:05 +0100
commitd59b9db031abee37a9aa9776662dd15370faabf4 (patch)
tree47481f2b5f1afbc122f494beca1375de661c1160 /libiptc/libip4tc.c
parent9cc4f24e72f87ca191c2e723e7cd293f6477481c (diff)
iptables: add -C to check for existing rules
It is often useful to check whether a specific rule is already present in a chain without actually modifying the iptables config. Services like fail2ban usually employ techniques like grepping through the output of "iptables -L" which is quite error prone. This patch adds a new operation -C to the iptables command which mostly works like -D; it can detect and indicate the existence of the specified rule by modifying the exit code. The new operation TC_CHECK_ENTRY uses the same code as the -D operation, whose functions got a dry-run parameter appended. Signed-off-by: Stefan Tomanek <> Signed-off-by: Jan Engelhardt <>
Diffstat (limited to 'libiptc/libip4tc.c')
1 files changed, 1 insertions, 0 deletions
diff --git a/libiptc/libip4tc.c b/libiptc/libip4tc.c
index c1d78e2b..e2d2a5ee 100644
--- a/libiptc/libip4tc.c
+++ b/libiptc/libip4tc.c
@@ -76,6 +76,7 @@ typedef unsigned int socklen_t;
#define TC_INSERT_ENTRY iptc_insert_entry
#define TC_REPLACE_ENTRY iptc_replace_entry
#define TC_APPEND_ENTRY iptc_append_entry
+#define TC_CHECK_ENTRY iptc_check_entry
#define TC_DELETE_ENTRY iptc_delete_entry
#define TC_DELETE_NUM_ENTRY iptc_delete_num_entry
#define TC_FLUSH_ENTRIES iptc_flush_entries