1 /* 2 * ebt_redirect 3 * 4 * Authors: 5 * Bart De Schuymer <bdschuym@pandora.be> 6 * 7 * April, 2002 8 * 9 */ 10 11 #include <linux/netfilter_bridge/ebtables.h> 12 #include <linux/netfilter_bridge/ebt_redirect.h> 13 #include <linux/module.h> 14 #include <net/sock.h> 15 #include "../br_private.h" 16 17 static int ebt_target_redirect(struct sk_buff **pskb, unsigned int hooknr, 18 const struct net_device *in, const struct net_device *out, 19 const void *data, unsigned int datalen) 20 { 21 struct ebt_redirect_info *info = (struct ebt_redirect_info *)data; 22 23 if (skb_shared(*pskb) || skb_cloned(*pskb)) { 24 struct sk_buff *nskb; 25 26 nskb = skb_copy(*pskb, GFP_ATOMIC); 27 if (!nskb) 28 return NF_DROP; 29 if ((*pskb)->sk) 30 skb_set_owner_w(nskb, (*pskb)->sk); 31 kfree_skb(*pskb); 32 *pskb = nskb; 33 } 34 if (hooknr != NF_BR_BROUTING) 35 memcpy(eth_hdr(*pskb)->h_dest, 36 in->br_port->br->dev->dev_addr, ETH_ALEN); 37 else 38 memcpy(eth_hdr(*pskb)->h_dest, in->dev_addr, ETH_ALEN); 39 (*pskb)->pkt_type = PACKET_HOST; 40 return info->target; 41 } 42 43 static int ebt_target_redirect_check(const char *tablename, unsigned int hookmask, 44 const struct ebt_entry *e, void *data, unsigned int datalen) 45 { 46 struct ebt_redirect_info *info = (struct ebt_redirect_info *)data; 47 48 if (datalen != EBT_ALIGN(sizeof(struct ebt_redirect_info))) 49 return -EINVAL; 50 if (BASE_CHAIN && info->target == EBT_RETURN) 51 return -EINVAL; 52 CLEAR_BASE_CHAIN_BIT; 53 if ( (strcmp(tablename, "nat") || hookmask & ~(1 << NF_BR_PRE_ROUTING)) && 54 (strcmp(tablename, "broute") || hookmask & ~(1 << NF_BR_BROUTING)) ) 55 return -EINVAL; 56 if (INVALID_TARGET) 57 return -EINVAL; 58 return 0; 59 } 60 61 static struct ebt_target redirect_target = 62 { 63 .name = EBT_REDIRECT_TARGET, 64 .target = ebt_target_redirect, 65 .check = ebt_target_redirect_check, 66 .me = THIS_MODULE, 67 }; 68 69 static int __init init(void) 70 { 71 return ebt_register_target(&redirect_target); 72 } 73 74 static void __exit fini(void) 75 { 76 ebt_unregister_target(&redirect_target); 77 } 78 79 module_init(init); 80 module_exit(fini); 81 MODULE_LICENSE("GPL"); 82