ebtables-compat: add nat match extensions
adds snat and dnat.
Translation for snat isn't complete, the --snat-arp switch isn't supported so far.
Signed-off-by: Florian Westphal <fw@strlen.de>
diff --git a/extensions/libebt_dnat.c b/extensions/libebt_dnat.c
new file mode 100644
index 0000000..c179d8c
--- /dev/null
+++ b/extensions/libebt_dnat.c
@@ -0,0 +1,134 @@
+/* ebt_nat
+ *
+ * Authors:
+ * Bart De Schuymer <bdschuym@pandora.be>
+ *
+ * June, 2002
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <getopt.h>
+#include <netinet/ether.h>
+#include <xtables.h>
+#include <linux/netfilter_bridge/ebt_nat.h>
+#include "iptables/nft.h"
+#include "iptables/nft-bridge.h"
+
+#define NAT_D '1'
+#define NAT_D_TARGET '2'
+static const struct option brdnat_opts[] =
+{
+ { "to-destination", required_argument, 0, NAT_D },
+ { "to-dst" , required_argument, 0, NAT_D },
+ { "dnat-target" , required_argument, 0, NAT_D_TARGET },
+ { 0 }
+};
+
+static void brdnat_print_help(void)
+{
+ printf(
+ "dnat options:\n"
+ " --to-dst address : MAC address to map destination to\n"
+ " --dnat-target target : ACCEPT, DROP, RETURN or CONTINUE\n");
+}
+
+static void brdnat_init(struct xt_entry_target *target)
+{
+ struct ebt_nat_info *natinfo = (struct ebt_nat_info *)target->data;
+
+ natinfo->target = EBT_ACCEPT;
+}
+
+#define OPT_DNAT 0x01
+#define OPT_DNAT_TARGET 0x02
+static int brdnat_parse(int c, char **argv, int invert, unsigned int *flags,
+ const void *entry, struct xt_entry_target **target)
+{
+ struct ebt_nat_info *natinfo = (struct ebt_nat_info *)(*target)->data;
+ struct ether_addr *addr;
+
+ switch (c) {
+ case NAT_D:
+ EBT_CHECK_OPTION(flags, OPT_DNAT);
+ if (!(addr = ether_aton(optarg)))
+ xtables_error(PARAMETER_PROBLEM, "Problem with specified --to-destination mac");
+ memcpy(natinfo->mac, addr, ETH_ALEN);
+ break;
+ case NAT_D_TARGET:
+ EBT_CHECK_OPTION(flags, OPT_DNAT_TARGET);
+ if (ebt_fill_target(optarg, (unsigned int *)&natinfo->target))
+ xtables_error(PARAMETER_PROBLEM, "Illegal --dnat-target target");
+ break;
+ default:
+ return 0;
+ }
+ return 1;
+}
+
+static void brdnat_final_check(unsigned int flags)
+{
+ if (!flags)
+ xtables_error(PARAMETER_PROBLEM,
+ "You must specify proper arguments");
+}
+
+static void ebt_print_mac(const unsigned char *mac)
+{
+ printf("%s", ether_ntoa((struct ether_addr *) mac));
+}
+
+static void brdnat_print(const void *ip, const struct xt_entry_target *target, int numeric)
+{
+ struct ebt_nat_info *natinfo = (struct ebt_nat_info *)target->data;
+
+ printf("--to-dst ");
+ ebt_print_mac(natinfo->mac);
+ printf(" --dnat-target %s", ebt_target_name(natinfo->target));
+}
+
+static const char* brdnat_verdict(int verdict)
+{
+ switch (verdict) {
+ case EBT_ACCEPT: return "accept";
+ case EBT_DROP: return "drop";
+ case EBT_CONTINUE: return "continue";
+ case EBT_RETURN: return "return";
+ }
+
+ return "";
+}
+
+static int brdnat_xlate(struct xt_xlate *xl,
+ const struct xt_xlate_tg_params *params)
+{
+ const struct ebt_nat_info *natinfo = (const void*)params->target->data;
+
+ xt_xlate_add(xl, "ether daddr set %s %s ",
+ ether_ntoa((struct ether_addr *)natinfo->mac),
+ brdnat_verdict(natinfo->target));
+
+ return 1;
+}
+
+static struct xtables_target brdnat_target =
+{
+ .name = "dnat",
+ .version = XTABLES_VERSION,
+ .family = NFPROTO_BRIDGE,
+ .size = XT_ALIGN(sizeof(struct ebt_nat_info)),
+ .userspacesize = XT_ALIGN(sizeof(struct ebt_nat_info)),
+ .help = brdnat_print_help,
+ .init = brdnat_init,
+ .parse = brdnat_parse,
+ .final_check = brdnat_final_check,
+ .print = brdnat_print,
+ .xlate = brdnat_xlate,
+ .extra_opts = brdnat_opts,
+};
+
+void _init(void)
+{
+ xtables_register_target(&brdnat_target);
+}