add support for connmark match/target

1 files changed, 167 insertions, 0 deletions

diff --git a/extensions/libipt_CONNMARK.c b/extensions/libipt_CONNMARK.c
new file mode 100644
index 0000000..824c1de
--- /dev/null
+++ b/extensions/libipt_CONNMARK.c
@@ -0,0 +1,167 @@
+/* Shared library add-on to iptables to add CONNMARK target support. */
+#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_CONNMARK.h>
+
+#if 0
+struct markinfo {
+	struct ipt_entry_target t;
+	struct ipt_connmark_target_info mark;
+};
+#endif
+
+/* Function which prints out usage message. */
+static void
+help(void)
+{
+	printf(
+"CONNMARK target v%s options:\n"
+"  --set-mark value              Set conntrack mark value\n"
+"  --save-mark                   Save the packet nfmark on the connection\n"
+"  --restore-mark                Restore saved nfmark value\n"
+"\n",
+NETFILTER_VERSION);
+}
+
+static struct option opts[] = {
+	{ "set-mark", 1, 0, '1' },
+	{ "save-mark", 0, 0, '2' },
+	{ "restore-mark", 0, 0, '3' },
+	{ 0 }
+};
+
+/* Initialize the target. */
+static void
+init(struct ipt_entry_target *t, unsigned int *nfcache)
+{
+}
+
+/* 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,
+      struct ipt_entry_target **target)
+{
+	struct ipt_connmark_target_info *markinfo
+		= (struct ipt_connmark_target_info *)(*target)->data;
+
+	switch (c) {
+		char *end;
+	case '1':
+		markinfo->mode = IPT_CONNMARK_SET;
+		markinfo->mark = strtoul(optarg, &end, 0);
+		if (*end != '\0' || end == optarg)
+			exit_error(PARAMETER_PROBLEM, "Bad MARK value `%s'", optarg);
+		if (*flags)
+			exit_error(PARAMETER_PROBLEM,
+			           "CONNMARK target: Can't specify --set-mark twice");
+		*flags = 1;
+		break;
+	case '2':
+		markinfo->mode = IPT_CONNMARK_SAVE;
+		if (*flags)
+			exit_error(PARAMETER_PROBLEM,
+			           "CONNMARK target: Can't specify --save-mark twice");
+		*flags = 1;
+		break;
+	case '3':
+		markinfo->mode = IPT_CONNMARK_RESTORE;
+		if (*flags)
+			exit_error(PARAMETER_PROBLEM,
+			           "CONNMARK target: Can't specify --restore-mark twice");
+		*flags = 1;
+		break;
+	default:
+		return 0;
+	}
+
+	return 1;
+}
+
+static void
+final_check(unsigned int flags)
+{
+	if (!flags)
+		exit_error(PARAMETER_PROBLEM,
+		           "CONNMARK target: Parameter --set-mark is required");
+}
+
+static void
+print_mark(unsigned long mark, int numeric)
+{
+	printf("0x%lx ", mark);
+}
+
+/* Prints out the targinfo. */
+static void
+print(const struct ipt_ip *ip,
+      const struct ipt_entry_target *target,
+      int numeric)
+{
+	const struct ipt_connmark_target_info *markinfo =
+		(const struct ipt_connmark_target_info *)target->data;
+	switch (markinfo->mode) {
+	case IPT_CONNMARK_SET:
+	    printf("CONNMARK set ");
+	    print_mark(markinfo->mark, numeric);
+	    break;
+	case IPT_CONNMARK_SAVE:
+	    printf("CONNMARK save ");
+	    break;
+	case IPT_CONNMARK_RESTORE:
+	    printf("CONNMARK restore ");
+	    break;
+	default:
+	    printf("ERROR: UNKNOWN CONNMARK MODE ");
+	    break;
+	}
+}
+
+/* Saves the union ipt_targinfo in parsable form to stdout. */
+static void
+save(const struct ipt_ip *ip, const struct ipt_entry_target *target)
+{
+	const struct ipt_connmark_target_info *markinfo =
+		(const struct ipt_connmark_target_info *)target->data;
+
+	switch (markinfo->mode) {
+	case IPT_CONNMARK_SET:
+	    printf("--set-mark 0x%lx ", markinfo->mark);
+	    break;
+	case IPT_CONNMARK_SAVE:
+	    printf("--save-mark ");
+	    break;
+	case IPT_CONNMARK_RESTORE:
+	    printf("--restore-mark ");
+	    break;
+	default:
+	    printf("ERROR: UNKNOWN CONNMARK MODE ");
+	    break;
+	}
+}
+
+struct iptables_target mark
+= { NULL,
+    "CONNMARK",
+    NETFILTER_VERSION,
+    IPT_ALIGN(sizeof(struct ipt_connmark_target_info)),
+    IPT_ALIGN(sizeof(struct ipt_connmark_target_info)),
+    &help,
+    &init,
+    &parse,
+    &final_check,
+    &print,
+    &save,
+    opts
+};
+
+void _init(void)
+{
+	register_target(&mark);
+}