added realm match from Sampsa Ranta

diff --git a/extensions/.realm-test b/extensions/.realm-test
new file mode 100755 (executable)
index 0000000..9eae97d
--- /dev/null
+++ b/extensions/.realm-test
@@ -0,0 +1,3 @@
+#!/bin/sh
+# True if nth is applied.
+[ -f $KERNEL_DIR/include/linux/netfilter_ipv4/ipt_realm.h ] && echo realm

diff --git a/extensions/libipt_realm.c b/extensions/libipt_realm.c
new file mode 100644 (file)
index 0000000..54bcb9a
--- /dev/null
+++ b/extensions/libipt_realm.c
@@ -0,0 +1,136 @@
+/* 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_realm.h>
+
+/* Function which prints out usage message. */
+static void
+help(void)
+{
+       printf(
+"REALM v%s options:\n"
+" --realm [!] value[/mask]\n"
+"                              Match realm\n"
+"\n", NETFILTER_VERSION);
+}
+
+static struct option opts[] = {
+       { "realm", 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_realm_info *realminfo = (struct ipt_realm_info *)(*match)->data;
+
+       switch (c) {
+               char *end;
+       case '1':
+               if (check_inverse(optarg, &invert))
+                       optind++;
+               realminfo->id = strtoul(optarg, &end, 0);
+               if (*end == '/') {
+                       realminfo->mask = strtoul(end+1, &end, 0);
+               } else
+                       realminfo->mask = 0xffffffff;
+               if (*end != '\0' || end == optarg)
+                       exit_error(PARAMETER_PROBLEM, "Bad REALM value `%s'", optarg);
+               if (invert)
+                       realminfo->invert = 1;
+               *flags = 1;
+               break;
+
+       default:
+               return 0;
+       }
+       return 1;
+}
+
+static void
+print_realm(unsigned long id, unsigned long mask, int invert, int numeric)
+{
+       if (invert)
+               fputc('!', stdout);
+
+       if(mask != 0xffffffff)
+               printf("0x%lx/0x%lx ", id, mask);
+       else
+               printf("0x%lx ", id);
+}
+
+/* Prints out the matchinfo. */
+static void
+print(const struct ipt_ip *ip,
+      const struct ipt_entry_match *match,
+      int numeric)
+{
+       printf("REALM match ");
+       print_realm(((struct ipt_realm_info *)match->data)->id,
+                  ((struct ipt_realm_info *)match->data)->mask,
+                  ((struct ipt_realm_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("--realm ");
+       print_realm(((struct ipt_realm_info *)match->data)->id,
+                  ((struct ipt_realm_info *)match->data)->mask,
+                  ((struct ipt_realm_info *)match->data)->invert, 0);
+}
+
+/* Final check; must have specified --mark. */
+static void
+final_check(unsigned int flags)
+{
+       if (!flags)
+               exit_error(PARAMETER_PROBLEM,
+                          "REALM match: You must specify `--realm'");
+}
+
+struct iptables_match realm
+= { NULL,
+    "realm",
+    NETFILTER_VERSION,
+    IPT_ALIGN(sizeof(struct ipt_realm_info)),
+    IPT_ALIGN(sizeof(struct ipt_realm_info)),
+    &help,
+    &init,
+    &parse,
+    &final_check,
+    &print,
+    &save,
+    opts
+};
+
+void _init(void)
+{
+       register_match(&realm);
+}
+
+