add support for connmark match/target

1 files changed, 129 insertions, 0 deletions

diff --git a/extensions/libipt_connmark.c b/extensions/libipt_connmark.c
new file mode 100644
index 00000000..e71d9629
--- /dev/null
+++ b/extensions/libipt_connmark.c
@@ -0,0 +1,129 @@
+/* Shared library add-on to iptables to add CONNMARK matching support. */
+#include <stdio.h>
+#include <netdb.h>
+#include <string.h>
+#include <stdlib.h>
+#include <getopt.h>
+
+#include <iptables.h>
+#include <linux/netfilter_ipv4/ipt_connmark.h>
+
+/* Function which prints out usage message. */
+static void
+help(void)
+{
+	printf(
+"CONNMARK match v%s options:\n"
+"[!] --mark value[/mask]         Match nfmark value with optional mask\n"
+"\n",
+NETFILTER_VERSION);
+}
+
+static struct option opts[] = {
+	{ "mark", 1, 0, '1' },
+	{0}
+};
+
+/* Initialize the match. */
+static void
+init(struct ipt_entry_match *m, unsigned int *nfcache)
+{
+	/* Can't cache this. */
+	*nfcache |= NFC_UNKNOWN;
+}
+
+/* Function which parses command options; returns true if it
+   ate an option */
+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)
+{
+	struct ipt_connmark_info *markinfo = (struct ipt_connmark_info *)(*match)->data;
+
+	switch (c) {
+		char *end;
+	case '1':
+		if (check_inverse(optarg, &invert))
+			optind++;
+		markinfo->mark = strtoul(optarg, &end, 0);
+		if (*end == '/') {
+			markinfo->mask = strtoul(end+1, &end, 0);
+		} else
+			markinfo->mask = 0xffffffff;
+		if (*end != '\0' || end == optarg)
+			exit_error(PARAMETER_PROBLEM, "Bad MARK value `%s'", optarg);
+		if (invert)
+			markinfo->invert = 1;
+		*flags = 1;
+		break;
+
+	default:
+		return 0;
+	}
+	return 1;
+}
+
+static void
+print_mark(unsigned long mark, unsigned long mask, int invert, int numeric)
+{
+	if (invert)
+		fputc('!', stdout);
+
+	if(mask != 0xffffffff)
+		printf("0x%lx/0x%lx ", mark, mask);
+	else
+		printf("0x%lx ", mark);
+}
+
+/* Final check; must have specified --mark. */
+static void
+final_check(unsigned int flags)
+{
+	if (!flags)
+		exit_error(PARAMETER_PROBLEM,
+			   "MARK match: You must specify `--mark'");
+}
+
+/* Prints out the matchinfo. */
+static void
+print(const struct ipt_ip *ip,
+      const struct ipt_entry_match *match,
+      int numeric)
+{
+	printf("CONNMARK match ");
+	print_mark(((struct ipt_connmark_info *)match->data)->mark,
+		  ((struct ipt_connmark_info *)match->data)->mask,
+		  ((struct ipt_connmark_info *)match->data)->invert, numeric);
+}
+
+/* Saves the union ipt_matchinfo in parsable form to stdout. */
+static void
+save(const struct ipt_ip *ip, const struct ipt_entry_match *match)
+{
+	printf("--mark ");
+	print_mark(((struct ipt_connmark_info *)match->data)->mark,
+		  ((struct ipt_connmark_info *)match->data)->mask,
+		  ((struct ipt_connmark_info *)match->data)->invert, 0);
+}
+
+struct iptables_match mark
+= { NULL,
+    "connmark",
+    NETFILTER_VERSION,
+    IPT_ALIGN(sizeof(struct ipt_connmark_info)),
+    IPT_ALIGN(sizeof(struct ipt_connmark_info)),
+    &help,
+    &init,
+    &parse,
+    &final_check,
+    &print,
+    &save,
+    opts
+};
+
+void _init(void)
+{
+	register_match(&mark);
+}