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author/C=EU/ST=EU/CN=Pablo Neira Ayuso/emailAddress=pablo@netfilter.org </C=EU/ST=EU/CN=Pablo Neira Ayuso/emailAddress=pablo@netfilter.org>2007-04-16 19:08:42 +0000
committer/C=EU/ST=EU/CN=Pablo Neira Ayuso/emailAddress=pablo@netfilter.org </C=EU/ST=EU/CN=Pablo Neira Ayuso/emailAddress=pablo@netfilter.org>2007-04-16 19:08:42 +0000
commit5eb3bc6d5594fccfff26329a26225f999e971652 (patch)
tree242b74bb06e32ef6d9621a73a0010b1c2ab7da4a /extensions
parentad31f852c3454136bdbfeb7f222cb9c175f13c1c (diff)
first step forward to merge conntrackd and conntrack into the same building chain
Diffstat (limited to 'extensions')
-rw-r--r--extensions/Makefile.am16
-rw-r--r--extensions/libct_proto_icmp.c108
-rw-r--r--extensions/libct_proto_icmp.man10
-rw-r--r--extensions/libct_proto_sctp.c164
-rw-r--r--extensions/libct_proto_tcp.c180
-rw-r--r--extensions/libct_proto_tcp.man16
-rw-r--r--extensions/libct_proto_udp.c141
-rw-r--r--extensions/libct_proto_udp.man13
8 files changed, 648 insertions, 0 deletions
diff --git a/extensions/Makefile.am b/extensions/Makefile.am
new file mode 100644
index 0000000..5366ee3
--- /dev/null
+++ b/extensions/Makefile.am
@@ -0,0 +1,16 @@
+include $(top_srcdir)/Make_global.am
+
+AM_CFLAGS=-fPIC -Wall
+LIBS=
+
+pkglib_LTLIBRARIES = ct_proto_tcp.la ct_proto_udp.la \
+ ct_proto_icmp.la ct_proto_sctp.la
+
+ct_proto_tcp_la_SOURCES = libct_proto_tcp.c
+ct_proto_tcp_la_LDFLAGS = -module -avoid-version
+ct_proto_udp_la_SOURCES = libct_proto_udp.c
+ct_proto_udp_la_LDFLAGS = -module -avoid-version
+ct_proto_icmp_la_SOURCES = libct_proto_icmp.c
+ct_proto_icmp_la_LDFLAGS = -module -avoid-version
+ct_proto_sctp_la_SOURCES = libct_proto_sctp.c
+ct_proto_sctp_la_LDFLAGS = -module -avoid-version
diff --git a/extensions/libct_proto_icmp.c b/extensions/libct_proto_icmp.c
new file mode 100644
index 0000000..e7cb04d
--- /dev/null
+++ b/extensions/libct_proto_icmp.c
@@ -0,0 +1,108 @@
+/*
+ * (C) 2005 by Pablo Neira Ayuso <pablo@eurodev.net>
+ * Harald Welte <laforge@netfilter.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ */
+#include <stdio.h>
+#include <getopt.h>
+#include <stdlib.h>
+#include <netinet/in.h> /* For htons */
+#include <netinet/ip_icmp.h>
+#include <libnetfilter_conntrack/libnetfilter_conntrack.h>
+#include <libnetfilter_conntrack/libnetfilter_conntrack_icmp.h>
+#include "conntrack.h"
+
+static struct option opts[] = {
+ {"icmp-type", 1, 0, '1'},
+ {"icmp-code", 1, 0, '2'},
+ {"icmp-id", 1, 0, '3'},
+ {0, 0, 0, 0}
+};
+
+static void help()
+{
+ fprintf(stdout, "--icmp-type icmp type\n");
+ fprintf(stdout, "--icmp-code icmp code\n");
+ fprintf(stdout, "--icmp-id icmp id\n");
+}
+
+/* Add 1; spaces filled with 0. */
+static u_int8_t invmap[]
+ = { [ICMP_ECHO] = ICMP_ECHOREPLY + 1,
+ [ICMP_ECHOREPLY] = ICMP_ECHO + 1,
+ [ICMP_TIMESTAMP] = ICMP_TIMESTAMPREPLY + 1,
+ [ICMP_TIMESTAMPREPLY] = ICMP_TIMESTAMP + 1,
+ [ICMP_INFO_REQUEST] = ICMP_INFO_REPLY + 1,
+ [ICMP_INFO_REPLY] = ICMP_INFO_REQUEST + 1,
+ [ICMP_ADDRESS] = ICMP_ADDRESSREPLY + 1,
+ [ICMP_ADDRESSREPLY] = ICMP_ADDRESS + 1};
+
+static int parse(char c, char *argv[],
+ struct nfct_tuple *orig,
+ struct nfct_tuple *reply,
+ struct nfct_tuple *exptuple,
+ struct nfct_tuple *mask,
+ union nfct_protoinfo *proto,
+ unsigned int *flags)
+{
+ switch(c) {
+ case '1':
+ if (optarg) {
+ orig->l4dst.icmp.type = atoi(optarg);
+ reply->l4dst.icmp.type =
+ invmap[orig->l4dst.icmp.type] - 1;
+ *flags |= ICMP_TYPE;
+ }
+ break;
+ case '2':
+ if (optarg) {
+ orig->l4dst.icmp.code = atoi(optarg);
+ reply->l4dst.icmp.code = 0;
+ *flags |= ICMP_CODE;
+ }
+ break;
+ case '3':
+ if (optarg) {
+ orig->l4src.icmp.id = htons(atoi(optarg));
+ reply->l4dst.icmp.id = 0;
+ *flags |= ICMP_ID;
+ }
+ break;
+ }
+ return 1;
+}
+
+static int final_check(unsigned int flags,
+ unsigned int command,
+ struct nfct_tuple *orig,
+ struct nfct_tuple *reply)
+{
+ if (!(flags & ICMP_TYPE))
+ return 0;
+ else if (!(flags & ICMP_CODE))
+ return 0;
+
+ return 1;
+}
+
+static struct ctproto_handler icmp = {
+ .name = "icmp",
+ .protonum = IPPROTO_ICMP,
+ .parse_opts = parse,
+ .final_check = final_check,
+ .help = help,
+ .opts = opts,
+ .version = VERSION,
+};
+
+static void __attribute__ ((constructor)) init(void);
+
+static void init(void)
+{
+ register_proto(&icmp);
+}
diff --git a/extensions/libct_proto_icmp.man b/extensions/libct_proto_icmp.man
new file mode 100644
index 0000000..3b860d0
--- /dev/null
+++ b/extensions/libct_proto_icmp.man
@@ -0,0 +1,10 @@
+This module matches on ICMP-specific fields.
+.TP
+.BI "--icmp-type " "TYPE"
+ICMP Type. Has to be specified numerically.
+.TP
+.BI "--icmp-code " "CODE"
+ICMP Code. Has to be specified numerically.
+.TP
+.BI "--icmp-id " "ID"
+ICMP Id. Has to be specified numerically.
diff --git a/extensions/libct_proto_sctp.c b/extensions/libct_proto_sctp.c
new file mode 100644
index 0000000..1c8f0d1
--- /dev/null
+++ b/extensions/libct_proto_sctp.c
@@ -0,0 +1,164 @@
+/*
+ * (C) 2005 by Harald Welte <laforge@netfilter.org>
+ * 2006 by Pablo Neira Ayuso <pablo@netfilter.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ */
+#include <stdio.h>
+#include <getopt.h>
+#include <stdlib.h>
+#include <string.h>
+#include <netinet/in.h> /* For htons */
+#include "conntrack.h"
+#include <libnetfilter_conntrack/libnetfilter_conntrack.h>
+#include <libnetfilter_conntrack/libnetfilter_conntrack_sctp.h>
+
+static struct option opts[] = {
+ {"orig-port-src", 1, 0, '1'},
+ {"orig-port-dst", 1, 0, '2'},
+ {"reply-port-src", 1, 0, '3'},
+ {"reply-port-dst", 1, 0, '4'},
+ {"state", 1, 0, '5'},
+ {"tuple-port-src", 1, 0, '6'},
+ {"tuple-port-dst", 1, 0, '7'},
+ {0, 0, 0, 0}
+};
+
+static const char *states[] = {
+ "NONE",
+ "CLOSED",
+ "COOKIE_WAIT",
+ "COOKIE_ECHOED",
+ "ESTABLISHED",
+ "SHUTDOWN_SENT",
+ "SHUTDOWN_RECV",
+ "SHUTDOWN_ACK_SENT",
+};
+
+static void help()
+{
+ fprintf(stdout, "--orig-port-src original source port\n");
+ fprintf(stdout, "--orig-port-dst original destination port\n");
+ fprintf(stdout, "--reply-port-src reply source port\n");
+ fprintf(stdout, "--reply-port-dst reply destination port\n");
+ fprintf(stdout, "--state SCTP state, fe. ESTABLISHED\n");
+ fprintf(stdout, "--tuple-port-src expectation tuple src port\n");
+ fprintf(stdout, "--tuple-port-src expectation tuple dst port\n");
+}
+
+static int parse_options(char c, char *argv[],
+ struct nfct_tuple *orig,
+ struct nfct_tuple *reply,
+ struct nfct_tuple *exptuple,
+ struct nfct_tuple *mask,
+ union nfct_protoinfo *proto,
+ unsigned int *flags)
+{
+ switch(c) {
+ case '1':
+ if (optarg) {
+ orig->l4src.sctp.port = htons(atoi(optarg));
+ *flags |= SCTP_ORIG_SPORT;
+ }
+ break;
+ case '2':
+ if (optarg) {
+ orig->l4dst.sctp.port = htons(atoi(optarg));
+ *flags |= SCTP_ORIG_DPORT;
+ }
+ break;
+ case '3':
+ if (optarg) {
+ reply->l4src.sctp.port = htons(atoi(optarg));
+ *flags |= SCTP_REPL_SPORT;
+ }
+ break;
+ case '4':
+ if (optarg) {
+ reply->l4dst.sctp.port = htons(atoi(optarg));
+ *flags |= SCTP_REPL_DPORT;
+ }
+ break;
+ case '5':
+ if (optarg) {
+ int i;
+ for (i=0; i<10; i++) {
+ if (strcmp(optarg, states[i]) == 0) {
+ /* FIXME: Add state to
+ * nfct_protoinfo
+ proto->sctp.state = i; */
+ break;
+ }
+ }
+ if (i == 10) {
+ printf("doh?\n");
+ return 0;
+ }
+ *flags |= SCTP_STATE;
+ }
+ break;
+ case '6':
+ if (optarg) {
+ exptuple->l4src.sctp.port = htons(atoi(optarg));
+ *flags |= SCTP_EXPTUPLE_SPORT;
+ }
+ break;
+ case '7':
+ if (optarg) {
+ exptuple->l4dst.sctp.port = htons(atoi(optarg));
+ *flags |= SCTP_EXPTUPLE_DPORT;
+ }
+
+ }
+ return 1;
+}
+
+static int final_check(unsigned int flags,
+ unsigned int command,
+ struct nfct_tuple *orig,
+ struct nfct_tuple *reply)
+{
+ int ret = 0;
+
+ if ((flags & (SCTP_ORIG_SPORT|SCTP_ORIG_DPORT))
+ && !(flags & (SCTP_REPL_SPORT|SCTP_REPL_DPORT))) {
+ reply->l4src.sctp.port = orig->l4dst.sctp.port;
+ reply->l4dst.sctp.port = orig->l4src.sctp.port;
+ ret = 1;
+ } else if (!(flags & (SCTP_ORIG_SPORT|SCTP_ORIG_DPORT))
+ && (flags & (SCTP_REPL_SPORT|SCTP_REPL_DPORT))) {
+ orig->l4src.sctp.port = reply->l4dst.sctp.port;
+ orig->l4dst.sctp.port = reply->l4src.sctp.port;
+ ret = 1;
+ }
+ if ((flags & (SCTP_ORIG_SPORT|SCTP_ORIG_DPORT))
+ && ((flags & (SCTP_REPL_SPORT|SCTP_REPL_DPORT))))
+ ret = 1;
+
+ /* --state is missing and we are trying to create a conntrack */
+ if (ret && (command & CT_CREATE) && (!(flags & SCTP_STATE)))
+ ret = 0;
+
+ return ret;
+}
+
+static struct ctproto_handler sctp = {
+ .name = "sctp",
+ .protonum = IPPROTO_SCTP,
+ .parse_opts = parse_options,
+ .final_check = final_check,
+ .help = help,
+ .opts = opts,
+ .version = VERSION,
+};
+
+static void __attribute__ ((constructor)) init(void);
+
+static void init(void)
+{
+ register_proto(&sctp);
+}
diff --git a/extensions/libct_proto_tcp.c b/extensions/libct_proto_tcp.c
new file mode 100644
index 0000000..ee24206
--- /dev/null
+++ b/extensions/libct_proto_tcp.c
@@ -0,0 +1,180 @@
+/*
+ * (C) 2005 by Pablo Neira Ayuso <pablo@eurodev.net>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ */
+#include <stdio.h>
+#include <getopt.h>
+#include <stdlib.h>
+#include <string.h>
+#include <netinet/in.h> /* For htons */
+#include <libnetfilter_conntrack/libnetfilter_conntrack.h>
+#include <libnetfilter_conntrack/libnetfilter_conntrack_tcp.h>
+
+#include "conntrack.h"
+
+static struct option opts[] = {
+ {"orig-port-src", 1, 0, '1'},
+ {"orig-port-dst", 1, 0, '2'},
+ {"reply-port-src", 1, 0, '3'},
+ {"reply-port-dst", 1, 0, '4'},
+ {"mask-port-src", 1, 0, '5'},
+ {"mask-port-dst", 1, 0, '6'},
+ {"state", 1, 0, '7'},
+ {"tuple-port-src", 1, 0, '8'},
+ {"tuple-port-dst", 1, 0, '9'},
+ {0, 0, 0, 0}
+};
+
+static const char *states[] = {
+ "NONE",
+ "SYN_SENT",
+ "SYN_RECV",
+ "ESTABLISHED",
+ "FIN_WAIT",
+ "CLOSE_WAIT",
+ "LAST_ACK",
+ "TIME_WAIT",
+ "CLOSE",
+ "LISTEN"
+};
+
+static void help()
+{
+ fprintf(stdout, "--orig-port-src original source port\n");
+ fprintf(stdout, "--orig-port-dst original destination port\n");
+ fprintf(stdout, "--reply-port-src reply source port\n");
+ fprintf(stdout, "--reply-port-dst reply destination port\n");
+ fprintf(stdout, "--mask-port-src mask source port\n");
+ fprintf(stdout, "--mask-port-dst mask destination port\n");
+ fprintf(stdout, "--tuple-port-src expectation tuple src port\n");
+ fprintf(stdout, "--tuple-port-src expectation tuple dst port\n");
+ fprintf(stdout, "--state TCP state, fe. ESTABLISHED\n");
+}
+
+static int parse_options(char c, char *argv[],
+ struct nfct_tuple *orig,
+ struct nfct_tuple *reply,
+ struct nfct_tuple *exptuple,
+ struct nfct_tuple *mask,
+ union nfct_protoinfo *proto,
+ unsigned int *flags)
+{
+ switch(c) {
+ case '1':
+ if (optarg) {
+ orig->l4src.tcp.port = htons(atoi(optarg));
+ *flags |= TCP_ORIG_SPORT;
+ }
+ break;
+ case '2':
+ if (optarg) {
+ orig->l4dst.tcp.port = htons(atoi(optarg));
+ *flags |= TCP_ORIG_DPORT;
+ }
+ break;
+ case '3':
+ if (optarg) {
+ reply->l4src.tcp.port = htons(atoi(optarg));
+ *flags |= TCP_REPL_SPORT;
+ }
+ break;
+ case '4':
+ if (optarg) {
+ reply->l4dst.tcp.port = htons(atoi(optarg));
+ *flags |= TCP_REPL_DPORT;
+ }
+ break;
+ case '5':
+ if (optarg) {
+ mask->l4src.tcp.port = htons(atoi(optarg));
+ *flags |= TCP_MASK_SPORT;
+ }
+ break;
+ case '6':
+ if (optarg) {
+ mask->l4dst.tcp.port = htons(atoi(optarg));
+ *flags |= TCP_MASK_DPORT;
+ }
+ break;
+ case '7':
+ if (optarg) {
+ int i;
+ for (i=0; i<10; i++) {
+ if (strcmp(optarg, states[i]) == 0) {
+ proto->tcp.state = i;
+ break;
+ }
+ }
+ if (i == 10) {
+ printf("doh?\n");
+ return 0;
+ }
+ *flags |= TCP_STATE;
+ }
+ break;
+ case '8':
+ if (optarg) {
+ exptuple->l4src.tcp.port = htons(atoi(optarg));
+ *flags |= TCP_EXPTUPLE_SPORT;
+ }
+ break;
+ case '9':
+ if (optarg) {
+ exptuple->l4dst.tcp.port = htons(atoi(optarg));
+ *flags |= TCP_EXPTUPLE_DPORT;
+ }
+ break;
+ }
+ return 1;
+}
+
+static int final_check(unsigned int flags,
+ unsigned int command,
+ struct nfct_tuple *orig,
+ struct nfct_tuple *reply)
+{
+ int ret = 0;
+
+ if ((flags & (TCP_ORIG_SPORT|TCP_ORIG_DPORT))
+ && !(flags & (TCP_REPL_SPORT|TCP_REPL_DPORT))) {
+ reply->l4src.tcp.port = orig->l4dst.tcp.port;
+ reply->l4dst.tcp.port = orig->l4src.tcp.port;
+ ret = 1;
+ } else if (!(flags & (TCP_ORIG_SPORT|TCP_ORIG_DPORT))
+ && (flags & (TCP_REPL_SPORT|TCP_REPL_DPORT))) {
+ orig->l4src.tcp.port = reply->l4dst.tcp.port;
+ orig->l4dst.tcp.port = reply->l4src.tcp.port;
+ ret = 1;
+ }
+ if ((flags & (TCP_ORIG_SPORT|TCP_ORIG_DPORT))
+ && ((flags & (TCP_REPL_SPORT|TCP_REPL_DPORT))))
+ ret = 1;
+
+ /* --state is missing and we are trying to create a conntrack */
+ if (ret && (command & CT_CREATE) && (!(flags & TCP_STATE)))
+ ret = 0;
+
+ return ret;
+}
+
+static struct ctproto_handler tcp = {
+ .name = "tcp",
+ .protonum = IPPROTO_TCP,
+ .parse_opts = parse_options,
+ .final_check = final_check,
+ .help = help,
+ .opts = opts,
+ .version = VERSION,
+};
+
+static void __attribute__ ((constructor)) init(void);
+
+static void init(void)
+{
+ register_proto(&tcp);
+}
diff --git a/extensions/libct_proto_tcp.man b/extensions/libct_proto_tcp.man
new file mode 100644
index 0000000..41783f8
--- /dev/null
+++ b/extensions/libct_proto_tcp.man
@@ -0,0 +1,16 @@
+This module matches on TCP-specific fields.
+.TP
+.BI "--orig-port-src " "PORT"
+Source port in original direction
+.TP
+.BI "--orig-port-dst " "PORT"
+Destination port in original direction
+.TP
+.BI "--reply-port-src " "PORT"
+Source port in reply direction
+.TP
+.BI "--reply-port-dst " "PORT"
+Destination port in reply direction
+.TP
+.BI "--state " "[NONE|SYN_SENT|SYN_RECV|ESTABLISHED|FIN_WAIT|CLOSE_WAIT|LAST_ACK|TIME_WAIT|CLOSE|LISTEN]"
+TCP state
diff --git a/extensions/libct_proto_udp.c b/extensions/libct_proto_udp.c
new file mode 100644
index 0000000..48079e0
--- /dev/null
+++ b/extensions/libct_proto_udp.c
@@ -0,0 +1,141 @@
+/*
+ * (C) 2005 by Pablo Neira Ayuso <pablo@eurodev.net>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ */
+#include <stdio.h>
+#include <getopt.h>
+#include <stdlib.h>
+#include <netinet/in.h> /* For htons */
+#include "conntrack.h"
+#include <libnetfilter_conntrack/libnetfilter_conntrack.h>
+#include <libnetfilter_conntrack/libnetfilter_conntrack_udp.h>
+
+static struct option opts[] = {
+ {"orig-port-src", 1, 0, '1'},
+ {"orig-port-dst", 1, 0, '2'},
+ {"reply-port-src", 1, 0, '3'},
+ {"reply-port-dst", 1, 0, '4'},
+ {"mask-port-src", 1, 0, '5'},
+ {"mask-port-dst", 1, 0, '6'},
+ {"tuple-port-src", 1, 0, '7'},
+ {"tuple-port-dst", 1, 0, '8'},
+ {0, 0, 0, 0}
+};
+
+static void help()
+{
+ fprintf(stdout, "--orig-port-src original source port\n");
+ fprintf(stdout, "--orig-port-dst original destination port\n");
+ fprintf(stdout, "--reply-port-src reply source port\n");
+ fprintf(stdout, "--reply-port-dst reply destination port\n");
+ fprintf(stdout, "--mask-port-src mask source port\n");
+ fprintf(stdout, "--mask-port-dst mask destination port\n");
+ fprintf(stdout, "--tuple-port-src expectation tuple src port\n");
+ fprintf(stdout, "--tuple-port-src expectation tuple dst port\n");
+}
+
+static int parse_options(char c, char *argv[],
+ struct nfct_tuple *orig,
+ struct nfct_tuple *reply,
+ struct nfct_tuple *exptuple,
+ struct nfct_tuple *mask,
+ union nfct_protoinfo *proto,
+ unsigned int *flags)
+{
+ switch(c) {
+ case '1':
+ if (optarg) {
+ orig->l4src.udp.port = htons(atoi(optarg));
+ *flags |= UDP_ORIG_SPORT;
+ }
+ break;
+ case '2':
+ if (optarg) {
+ orig->l4dst.udp.port = htons(atoi(optarg));
+ *flags |= UDP_ORIG_DPORT;
+ }
+ break;
+ case '3':
+ if (optarg) {
+ reply->l4src.udp.port = htons(atoi(optarg));
+ *flags |= UDP_REPL_SPORT;
+ }
+ break;
+ case '4':
+ if (optarg) {
+ reply->l4dst.udp.port = htons(atoi(optarg));
+ *flags |= UDP_REPL_DPORT;
+ }
+ break;
+ case '5':
+ if (optarg) {
+ mask->l4src.udp.port = htons(atoi(optarg));
+ *flags |= UDP_MASK_SPORT;
+ }
+ break;
+ case '6':
+ if (optarg) {
+ mask->l4dst.udp.port = htons(atoi(optarg));
+ *flags |= UDP_MASK_DPORT;
+ }
+ break;
+ case '7':
+ if (optarg) {
+ exptuple->l4src.udp.port = htons(atoi(optarg));
+ *flags |= UDP_EXPTUPLE_SPORT;
+ }
+ break;
+ case '8':
+ if (optarg) {
+ exptuple->l4dst.udp.port = htons(atoi(optarg));
+ *flags |= UDP_EXPTUPLE_DPORT;
+ }
+
+ }
+ return 1;
+}
+
+static int final_check(unsigned int flags,
+ unsigned int command,
+ struct nfct_tuple *orig,
+ struct nfct_tuple *reply)
+{
+ if ((flags & (UDP_ORIG_SPORT|UDP_ORIG_DPORT))
+ && !(flags & (UDP_REPL_SPORT|UDP_REPL_DPORT))) {
+ reply->l4src.udp.port = orig->l4dst.udp.port;
+ reply->l4dst.udp.port = orig->l4src.udp.port;
+ return 1;
+ } else if (!(flags & (UDP_ORIG_SPORT|UDP_ORIG_DPORT))
+ && (flags & (UDP_REPL_SPORT|UDP_REPL_DPORT))) {
+ orig->l4src.udp.port = reply->l4dst.udp.port;
+ orig->l4dst.udp.port = reply->l4src.udp.port;
+ return 1;
+ }
+ if ((flags & (UDP_ORIG_SPORT|UDP_ORIG_DPORT))
+ && ((flags & (UDP_REPL_SPORT|UDP_REPL_DPORT))))
+ return 1;
+
+ return 0;
+}
+
+static struct ctproto_handler udp = {
+ .name = "udp",
+ .protonum = IPPROTO_UDP,
+ .parse_opts = parse_options,
+ .final_check = final_check,
+ .help = help,
+ .opts = opts,
+ .version = VERSION,
+};
+
+static void __attribute__ ((constructor)) init(void);
+
+static void init(void)
+{
+ register_proto(&udp);
+}
diff --git a/extensions/libct_proto_udp.man b/extensions/libct_proto_udp.man
new file mode 100644
index 0000000..c67fedf
--- /dev/null
+++ b/extensions/libct_proto_udp.man
@@ -0,0 +1,13 @@
+This module matches on UDP-specific fields.
+.TP
+.BI "--orig-port-src " "PORT"
+Source port in original direction
+.TP
+.BI "--orig-port-dst " "PORT"
+Destination port in original direction
+.TP
+.BI "--reply-port-src " "PORT"
+Source port in reply direction
+.TP
+.BI "--reply-port-dst " "PORT"
+Destination port in reply direction