From 5a82480de02277b7b85140dcd06c28f26d40c58f Mon Sep 17 00:00:00 2001
From: Bart De Schuymer <bdschuym@pandora.be>
Date: Thu, 14 Aug 2003 19:24:25 +0000
Subject: from Grzegorz Borowiak

---
 extensions/ebt_arpreply.c | 132 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 132 insertions(+)
 create mode 100644 extensions/ebt_arpreply.c

(limited to 'extensions')

diff --git a/extensions/ebt_arpreply.c b/extensions/ebt_arpreply.c
new file mode 100644
index 0000000..0cbc630
--- /dev/null
+++ b/extensions/ebt_arpreply.c
@@ -0,0 +1,132 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <netinet/ether.h>
+#include <getopt.h>
+#include "../include/ebtables_u.h"
+#include <linux/netfilter_bridge/ebt_arpreply.h>
+
+static int mac_supplied;
+
+#define REPLY_MAC '1'
+#define REPLY_TARGET '2'
+static struct option opts[] =
+{
+	{ "arpreply-mac" ,    required_argument, 0, REPLY_MAC    },
+	{ "arpreply-target" , required_argument, 0, REPLY_TARGET },
+	{ 0 }
+};
+
+static void print_help()
+{
+	printf(
+	"arpreply target options:\n"
+	" --arpreply-mac address           : source MAC of generated reply\n"
+	" --arpreply-target target         : ACCEPT, DROP, RETURN or CONTINUE\n"
+	"                                    (standard target is DROP)\n");
+}
+
+static void init(struct ebt_entry_target *target)
+{
+	struct ebt_arpreply_info *replyinfo =
+	   (struct ebt_arpreply_info *)target->data;
+
+	replyinfo->target = EBT_DROP;
+	memset(replyinfo->mac, 0, ETH_ALEN);
+	mac_supplied = 0;
+}
+
+#define OPT_REPLY_MAC     0x01
+#define OPT_REPLY_TARGET  0x02
+static int parse(int c, char **argv, int argc,
+   const struct ebt_u_entry *entry, unsigned int *flags,
+   struct ebt_entry_target **target)
+{
+	struct ebt_arpreply_info *replyinfo =
+	   (struct ebt_arpreply_info *)(*target)->data;
+	struct ether_addr *addr;
+
+	switch (c) {
+	case REPLY_MAC:
+		check_option(flags, OPT_REPLY_MAC);
+		if (!(addr = ether_aton(optarg)))
+			print_error("Problem with specified "
+			            "--arpreply-mac mac");
+		memcpy(replyinfo->mac, addr, ETH_ALEN);
+		mac_supplied = 1;
+		break;
+	case REPLY_TARGET:
+		check_option(flags, OPT_REPLY_TARGET);
+		if (FILL_TARGET(optarg, replyinfo->target))
+			print_error("Illegal --arpreply-target target");
+		break;
+
+	default:
+		return 0;
+	}
+	return 1;
+}
+
+static void final_check(const struct ebt_u_entry *entry,
+   const struct ebt_entry_target *target, const char *name,
+   unsigned int hookmask, unsigned int time)
+{
+	struct ebt_arpreply_info *replyinfo =
+	   (struct ebt_arpreply_info *)target->data;
+
+	if (entry->ethproto != ETH_P_ARP || entry->invflags & EBT_IPROTO)
+		print_error("For ARP replying the protocol must be "
+		            "specified as ARP");
+	if (time == 0 && mac_supplied == 0)
+		print_error("No arpreply mac supplied");
+	if (BASE_CHAIN && replyinfo->target == EBT_RETURN)
+		print_error("--arpreply-target RETURN not allowed on "
+		            "base chain");
+	CLEAR_BASE_CHAIN_BIT;
+	if (strcmp(name, "nat") || hookmask & ~(1 << NF_BR_PRE_ROUTING))
+		print_error("arpreply only allowed in PREROUTING");
+}
+
+static void print(const struct ebt_u_entry *entry,
+   const struct ebt_entry_target *target)
+{
+	struct ebt_arpreply_info *replyinfo =
+	   (struct ebt_arpreply_info *)target->data;
+
+	printf("--arpreply-mac ");
+	print_mac(replyinfo->mac);
+	if (replyinfo->target == EBT_DROP)
+		return;
+	printf(" --arpreply-target %s", TARGET_NAME(replyinfo->target));
+}
+
+static int compare(const struct ebt_entry_target *t1,
+   const struct ebt_entry_target *t2)
+{
+	struct ebt_arpreply_info *replyinfo1 =
+	   (struct ebt_arpreply_info *)t1->data;
+	struct ebt_arpreply_info *replyinfo2 =
+	   (struct ebt_arpreply_info *)t2->data;
+
+	return memcmp(replyinfo1->mac, replyinfo2->mac, ETH_ALEN) == 0
+		&& replyinfo1->target == replyinfo2->target;
+}
+
+static struct ebt_u_target arpreply_target =
+{
+	EBT_ARPREPLY_TARGET,
+	sizeof(struct ebt_arpreply_info),
+	print_help,
+	init,
+	parse,
+	final_check,
+	print,
+	compare,
+	opts
+};
+
+static void _init(void) __attribute__ ((constructor));
+static void _init(void)
+{
+	register_target(&arpreply_target);
+}
-- 
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