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authorHarald Welte <laforge@gnumonks.org>2002-05-29 15:11:49 +0000
committerHarald Welte <laforge@gnumonks.org>2002-05-29 15:11:49 +0000
commit7a44731615d950a2966737d1d1c960859023f3a3 (patch)
tree9c5a189f331e05fd216c6fb426aa825cca2e2193 /extensions/libipt_ecn.c
parent7b49af40179706d42d98cb72330a07df37dcb7ea (diff)
add ECN match plugin
Diffstat (limited to 'extensions/libipt_ecn.c')
-rw-r--r--extensions/libipt_ecn.c187
1 files changed, 187 insertions, 0 deletions
diff --git a/extensions/libipt_ecn.c b/extensions/libipt_ecn.c
new file mode 100644
index 00000000..7dcee2c8
--- /dev/null
+++ b/extensions/libipt_ecn.c
@@ -0,0 +1,187 @@
+/* Shared library add-on to iptables for ECN matching
+ *
+ * (C) 2002 by Harald Welte <laforge@gnumonks.org>
+ *
+ * This program is distributed under the terms of GNU GPL v2, 1991
+ *
+ * libipt_ecn.c borrowed heavily from libipt_dscp.c
+ *
+ */
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <getopt.h>
+
+#include <iptables.h>
+#include <linux/netfilter_ipv4/ip_tables.h>
+#include <linux/netfilter_ipv4/ipt_ecn.h>
+
+static void init(struct ipt_entry_match *m, unsigned int *nfcache)
+{
+ *nfcache |= NFC_IP_TOS;
+}
+
+static void help(void)
+{
+ printf(
+"ECN match v%s options\n"
+"[!] --ecn-tcp-cwr Match CWR bit of TCP header\n"
+"[!] --ecn-tcp-ece Match ECE bit of TCP header\n"
+"[!] --ecn-ip-ect [0..3] Match ECN codepoint in IPv4 header\n",
+ IPTABLES_VERSION);
+}
+
+static struct option opts[] = {
+ { "ecn-tcp-cwr", 0, 0, 'F' },
+ { "ecn-tcp-ece", 0, 0, 'G' },
+ { "ecn-ip-ect", 1, 0, 'H' },
+ { 0 }
+};
+
+static int
+parse(int c, char **argv, int invert, unsigned int *flags,
+ const struct ipt_entry *entry,
+ unsigned int *nfcache,
+ struct ipt_entry_match **match)
+{
+ unsigned int result;
+ struct ipt_ecn_info *einfo
+ = (struct ipt_ecn_info *)(*match)->data;
+
+ switch (c) {
+ case 'F':
+ if (*flags & IPT_ECN_OP_MATCH_CWR)
+ exit_error(PARAMETER_PROBLEM,
+ "ECN match: can only use parameter ONCE!");
+ check_inverse(optarg, &invert, &optind, 0);
+ einfo->operation |= IPT_ECN_OP_MATCH_CWR;
+ if (invert)
+ einfo->invert |= IPT_ECN_OP_MATCH_CWR;
+ *flags |= IPT_ECN_OP_MATCH_CWR;
+ break;
+
+ case 'G':
+ if (*flags & IPT_ECN_OP_MATCH_ECE)
+ exit_error(PARAMETER_PROBLEM,
+ "ECN match: can only use parameter ONCE!");
+ check_inverse(optarg, &invert, &optind, 0);
+ einfo->operation |= IPT_ECN_OP_MATCH_ECE;
+ if (invert)
+ einfo->invert |= IPT_ECN_OP_MATCH_ECE;
+ *flags |= IPT_ECN_OP_MATCH_ECE;
+ break;
+
+ case 'H':
+ if (*flags & IPT_ECN_OP_MATCH_IP)
+ exit_error(PARAMETER_PROBLEM,
+ "ECN match: can only use parameter ONCE!");
+ check_inverse(optarg, &invert, &optind, 0);
+ if (invert)
+ einfo->invert |= IPT_ECN_OP_MATCH_IP;
+ *flags |= IPT_ECN_OP_MATCH_IP;
+ einfo->operation |= IPT_ECN_OP_MATCH_IP;
+ if (string_to_number(optarg, 0, 3, &result))
+ exit_error(PARAMETER_PROBLEM,
+ "ECN match: Value out of range");
+ einfo->ip_ect = result;
+ break;
+ default:
+ return 0;
+ }
+
+ return 1;
+}
+
+static void
+final_check(unsigned int flags)
+{
+ if (!flags)
+ exit_error(PARAMETER_PROBLEM,
+ "ECN match: some option required");
+}
+
+static void
+print_dscp(u_int8_t dscp, int invert, int numeric)
+{
+ if (invert)
+ fputc('!', stdout);
+
+ printf("0x%02x ", dscp);
+}
+
+/* Prints out the matchinfo. */
+static void
+print(const struct ipt_ip *ip,
+ const struct ipt_entry_match *match,
+ int numeric)
+{
+ const struct ipt_ecn_info *einfo =
+ (const struct ipt_ecn_info *)match->data;
+
+ printf("ECN match ");
+
+ if (einfo->operation & IPT_ECN_OP_MATCH_ECE) {
+ if (einfo->invert & IPT_ECN_OP_MATCH_ECE)
+ fputc('!', stdout);
+ printf("ECE ");
+ }
+
+ if (einfo->operation & IPT_ECN_OP_MATCH_CWR) {
+ if (einfo->invert & IPT_ECN_OP_MATCH_CWR)
+ fputc('!', stdout);
+ printf("CWR ");
+ }
+
+ if (einfo->operation & IPT_ECN_OP_MATCH_IP) {
+ if (einfo->invert & IPT_ECN_OP_MATCH_IP)
+ fputc('!', stdout);
+ printf("ECT=%d ", einfo->ip_ect);
+ }
+}
+
+/* Saves the union ipt_matchinfo in parsable form to stdout. */
+static void
+save(const struct ipt_ip *ip, const struct ipt_entry_match *match)
+{
+ const struct ipt_ecn_info *einfo =
+ (const struct ipt_ecn_info *)match->data;
+
+ if (einfo->operation & IPT_ECN_OP_MATCH_ECE) {
+ if (einfo->invert & IPT_ECN_OP_MATCH_ECE)
+ printf("! ");
+ printf("--ecn-tcp-ece ");
+ }
+
+ if (einfo->operation & IPT_ECN_OP_MATCH_CWR) {
+ if (einfo->invert & IPT_ECN_OP_MATCH_CWR)
+ printf("! ");
+ printf("--ecn-tcp-cwr ");
+ }
+
+ if (einfo->operation & IPT_ECN_OP_MATCH_IP) {
+ if (einfo->invert & IPT_ECN_OP_MATCH_IP)
+ printf("! ");
+ printf("--ecn-ip-ect %d", einfo->ip_ect);
+ }
+}
+
+static
+struct iptables_match ecn
+= { NULL,
+ "ecn",
+ IPTABLES_VERSION,
+ IPT_ALIGN(sizeof(struct ipt_ecn_info)),
+ IPT_ALIGN(sizeof(struct ipt_ecn_info)),
+ &help,
+ &init,
+ &parse,
+ &final_check,
+ &print,
+ &save,
+ opts
+};
+
+void _init(void)
+{
+ register_match(&ecn);
+}