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-rw-r--r--extensions/libipt_mac.c144
1 files changed, 144 insertions, 0 deletions
diff --git a/extensions/libipt_mac.c b/extensions/libipt_mac.c
new file mode 100644
index 00000000..36d89692
--- /dev/null
+++ b/extensions/libipt_mac.c
@@ -0,0 +1,144 @@
+/* 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 <iptables.h>
+#include <linux/netfilter_ipv4/ipt_mac.h>
+
+/* Function which prints out usage message. */
+static void
+help(void)
+{
+ printf(
+"MAC v%s options:\n"
+" --mac-source [!] XX:XX:XX:XX:XX:XX\n"
+" Match source MAC address\n"
+"\n", NETFILTER_VERSION);
+}
+
+static struct option opts[] = {
+ { "mac-source", 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;
+}
+
+static void
+parse_mac(const char *mac, struct ipt_mac_info *info)
+{
+ unsigned int i = 0;
+
+ if (strlen(mac) != ETH_ALEN*3-1)
+ exit_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
+ exit_error(PARAMETER_PROBLEM,
+ "Bad mac address `%s'", mac);
+ }
+}
+
+/* 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_mac_info *macinfo = (struct ipt_mac_info *)(*match)->data;
+
+ switch (c) {
+ case '1':
+ if (check_inverse(optarg, &invert))
+ optind++;
+ parse_mac(argv[optind-1], macinfo);
+ if (invert)
+ macinfo->invert = 1;
+ *flags = 1;
+ break;
+
+ default:
+ return 0;
+ }
+
+ return 1;
+}
+
+static void print_mac(unsigned char macaddress[ETH_ALEN], int invert)
+{
+ unsigned int i;
+
+ printf("%s%02X", invert ? "!" : "", macaddress[0]);
+ for (i = 1; i < ETH_ALEN; i++)
+ printf(":%02X", macaddress[i]);
+ printf(" ");
+}
+
+/* Final check; must have specified --mac. */
+static void final_check(unsigned int flags)
+{
+ if (!flags)
+ exit_error(PARAMETER_PROBLEM,
+ "You must specify `--mac-source'");
+}
+
+/* Prints out the matchinfo. */
+static void
+print(const struct ipt_ip *ip,
+ const struct ipt_entry_match *match,
+ int numeric)
+{
+ printf("MAC ");
+ print_mac(((struct ipt_mac_info *)match->data)->srcaddr,
+ ((struct ipt_mac_info *)match->data)->invert);
+}
+
+/* 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("--mac ");
+ print_mac(((struct ipt_mac_info *)match->data)->srcaddr,
+ ((struct ipt_mac_info *)match->data)->invert);
+}
+
+struct iptables_match mac
+= { NULL,
+ "mac",
+ NETFILTER_VERSION,
+ sizeof(struct ipt_mac_info),
+ &help,
+ &init,
+ &parse,
+ &final_check,
+ &print,
+ &save,
+ opts
+};
+
+void _init(void)
+{
+ register_match(&mac);
+}