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authorBart De Schuymer <bdschuym@pandora.be>2003-08-14 19:55:22 +0000
committerBart De Schuymer <bdschuym@pandora.be>2003-08-14 19:55:22 +0000
commit31cdf1b65f5f38bf7bfe3d618b5a5e1a35ff7ea2 (patch)
treeb52bb44090964419cbc481c4511f5a1e37d2dd61
parent11c8fcfe081ff72ae934f9f4193fe0abdbc2a270 (diff)
by Grzegorz Borowiak
-rw-r--r--kernel/linux/include/linux/netfilter_bridge/ebt_arpreply.h11
-rw-r--r--kernel/linux/net/bridge/netfilter/ebt_arpreply.c83
2 files changed, 94 insertions, 0 deletions
diff --git a/kernel/linux/include/linux/netfilter_bridge/ebt_arpreply.h b/kernel/linux/include/linux/netfilter_bridge/ebt_arpreply.h
new file mode 100644
index 0000000..96a8339
--- /dev/null
+++ b/kernel/linux/include/linux/netfilter_bridge/ebt_arpreply.h
@@ -0,0 +1,11 @@
+#ifndef __LINUX_BRIDGE_EBT_ARPREPLY_H
+#define __LINUX_BRIDGE_EBT_ARPREPLY_H
+
+struct ebt_arpreply_info
+{
+ unsigned char mac[ETH_ALEN];
+ int target;
+};
+#define EBT_ARPREPLY_TARGET "arpreply"
+
+#endif
diff --git a/kernel/linux/net/bridge/netfilter/ebt_arpreply.c b/kernel/linux/net/bridge/netfilter/ebt_arpreply.c
new file mode 100644
index 0000000..91bb1ca
--- /dev/null
+++ b/kernel/linux/net/bridge/netfilter/ebt_arpreply.c
@@ -0,0 +1,83 @@
+/*
+ * ebt_reply
+ *
+ * Authors:
+ * Grzegorz Borowiak <grzes@gnu.univ.gda.pl>
+ *
+ * August, 2003
+ *
+ */
+
+#include <linux/netfilter_bridge/ebtables.h>
+#include <linux/netfilter_bridge/ebt_arpreply.h>
+#include <linux/if_arp.h>
+#include <linux/module.h>
+
+static int ebt_target_reply(struct sk_buff **pskb, unsigned int hooknr,
+ const struct net_device *in, const struct net_device *out,
+ const void *data, unsigned int datalen)
+{
+ struct ebt_arpreply_info *info = (struct ebt_arpreply_info *)data;
+ struct arphdr *ah;
+ unsigned char *sha, *arp_ptr;
+ u32 sip, tip;
+
+ ah = (**pskb).nh.arph;
+ if (ah->ar_op != __constant_htons(ARPOP_REQUEST) ||
+ ah->ar_hln != ETH_ALEN || ah->ar_pro != htons(ETH_P_IP) ||
+ ah->ar_pln != 4)
+ return EBT_CONTINUE;
+
+ arp_ptr = (unsigned char *)(ah + 1);
+
+ /* get source and target IP */
+ sha = arp_ptr;
+ arp_ptr += ETH_ALEN;
+ memcpy(&sip, arp_ptr, 4);
+ arp_ptr += 4 + ETH_ALEN;
+ memcpy(&tip, arp_ptr, 4);
+
+ arp_send(ARPOP_REPLY, ETH_P_ARP, sip, in, tip, sha, info->mac, sha);
+
+ return info->target;
+}
+
+static int ebt_target_reply_check(const char *tablename, unsigned int hookmask,
+ const struct ebt_entry *e, void *data, unsigned int datalen)
+{
+ struct ebt_arpreply_info *info = (struct ebt_arpreply_info *)data;
+
+ if (datalen != EBT_ALIGN(sizeof(struct ebt_arpreply_info)))
+ return -EINVAL;
+ if (BASE_CHAIN && info->target == EBT_RETURN)
+ return -EINVAL;
+ if (e->ethproto != __constant_htons(ETH_P_ARP) ||
+ e->invflags & EBT_IPROTO)
+ return -EINVAL;
+ CLEAR_BASE_CHAIN_BIT;
+ if (strcmp(tablename, "nat") || hookmask & ~(1 << NF_BR_PRE_ROUTING))
+ return -EINVAL;
+ return 0;
+}
+
+static struct ebt_target reply_target =
+{
+ .name = EBT_ARPREPLY_TARGET,
+ .target = ebt_target_reply,
+ .check = ebt_target_reply_check,
+ .me = THIS_MODULE,
+};
+
+static int __init init(void)
+{
+ return ebt_register_target(&reply_target);
+}
+
+static void __exit fini(void)
+{
+ ebt_unregister_target(&reply_target);
+}
+
+module_init(init);
+module_exit(fini);
+MODULE_LICENSE("GPL");