1 files changed, 131 insertions, 0 deletions
diff --git a/extensions/libxt_mac.c b/extensions/libxt_mac.c
new file mode 100644
index 0000000..00996a0
--- /dev/null
+++ b/extensions/libxt_mac.c
@@ -0,0 +1,131 @@
+/* Shared library add-on to iptables to add MAC address support. */
+#include <stdio.h>
+#include <netdb.h>
+#include <string.h>
+#include <stdlib.h>
+#include <getopt.h>
+#if defined(__GLIBC__) && __GLIBC__ == 2
+#include <net/ethernet.h>
+#else
+#include <linux/if_ether.h>
+#endif
+#include <xtables.h>
+#include <linux/netfilter/xt_mac.h>
+
+static void mac_help(void)
+{
+	printf(
+"mac match options:\n"
+"[!] --mac-source XX:XX:XX:XX:XX:XX\n"
+"				Match source MAC address\n");
+}
+
+static const struct option mac_opts[] = {
+	{ "mac-source", 1, NULL, '1' },
+	{ .name = NULL }
+};
+
+static void
+parse_mac(const char *mac, struct xt_mac_info *info)
+{
+	unsigned int i = 0;
+
+	if (strlen(mac) != ETH_ALEN*3-1)
+		xtables_error(PARAMETER_PROBLEM, "Bad mac address \"%s\"", mac);
+
+	for (i = 0; i < ETH_ALEN; i++) {
+		long number;
+		char *end;
+
+		number = strtol(mac + i*3, &end, 16);
+
+		if (end == mac + i*3 + 2
+		    && number >= 0
+		    && number <= 255)
+			info->srcaddr[i] = number;
+		else
+			xtables_error(PARAMETER_PROBLEM,
+				   "Bad mac address `%s'", mac);
+	}
+}
+
+static int
+mac_parse(int c, char **argv, int invert, unsigned int *flags,
+          const void *entry, struct xt_entry_match **match)
+{
+	struct xt_mac_info *macinfo = (struct xt_mac_info *)(*match)->data;
+
+	switch (c) {
+	case '1':
+		xtables_check_inverse(optarg, &invert, &optind, 0, argv);
+		parse_mac(optarg, macinfo);
+		if (invert)
+			macinfo->invert = 1;
+		*flags = 1;
+		break;
+
+	default:
+		return 0;
+	}
+
+	return 1;
+}
+
+static void print_mac(const unsigned char macaddress[ETH_ALEN])
+{
+	unsigned int i;
+
+	printf("%02X", macaddress[0]);
+	for (i = 1; i < ETH_ALEN; i++)
+		printf(":%02X", macaddress[i]);
+	printf(" ");
+}
+
+static void mac_check(unsigned int flags)
+{
+	if (!flags)
+		xtables_error(PARAMETER_PROBLEM,
+			   "You must specify `--mac-source'");
+}
+
+static void
+mac_print(const void *ip, const struct xt_entry_match *match, int numeric)
+{
+	const struct xt_mac_info *info = (void *)match->data;
+	printf("MAC ");
+
+	if (info->invert)
+		printf("! ");
+	
+	print_mac(info->srcaddr);
+}
+
+static void mac_save(const void *ip, const struct xt_entry_match *match)
+{
+	const struct xt_mac_info *info = (void *)match->data;
+
+	if (info->invert)
+		printf("! ");
+
+	printf("--mac-source ");
+	print_mac(info->srcaddr);
+}
+
+static struct xtables_match mac_match = {
+	.family		= NFPROTO_UNSPEC,
+ 	.name		= "mac",
+	.version	= XTABLES_VERSION,
+	.size		= XT_ALIGN(sizeof(struct xt_mac_info)),
+	.userspacesize	= XT_ALIGN(sizeof(struct xt_mac_info)),
+	.help		= mac_help,
+	.parse		= mac_parse,
+	.final_check	= mac_check,
+	.print		= mac_print,
+	.save		= mac_save,
+	.extra_opts	= mac_opts,
+};
+
+void _init(void)
+{
+	xtables_register_match(&mac_match);
+}