1/* 2 * Handle incoming frames 3 * Linux ethernet bridge 4 * 5 * Authors: 6 * Lennert Buytenhek <buytenh@gnu.org> 7 * 8 * This program is free software; you can redistribute it and/or 9 * modify it under the terms of the GNU General Public License 10 * as published by the Free Software Foundation; either version 11 * 2 of the License, or (at your option) any later version. 12 */ 13 14#include <linux/slab.h> 15#include <linux/kernel.h> 16#include <linux/netdevice.h> 17#include <linux/etherdevice.h> 18#include <linux/netfilter_bridge.h> 19#include "br_private.h" 20 21/* Bridge group multicast address 802.1d (pg 51). */ 22const u8 br_group_address[ETH_ALEN] = { 0x01, 0x80, 0xc2, 0x00, 0x00, 0x00 }; 23 24int qos_enable = 0; /* Foxconn added pling 03/13/2007 */ 25static int br_pass_frame_up(struct sk_buff *skb) 26{ 27 struct net_device *indev, *brdev = BR_INPUT_SKB_CB(skb)->brdev; 28 struct net_bridge *br = netdev_priv(brdev); 29 struct br_cpu_netstats *brstats = this_cpu_ptr(br->stats); 30 31 u64_stats_update_begin(&brstats->syncp); 32 brstats->rx_packets++; 33 brstats->rx_bytes += skb->len; 34 u64_stats_update_end(&brstats->syncp); 35 36 indev = skb->dev; 37 /* foxconn wklin added, 2010/06/15 @attach_dev */ 38 if (htons(ETH_P_ARP) == eth_hdr(skb)->h_proto) 39 *(pp_bridge_indev(skb)) = indev;/*backup incoming port to be used in arp.c */ 40 skb->dev = brdev; 41 42 return NF_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_IN, skb, indev, NULL, 43 netif_receive_skb); 44} 45 46/* note: already called with rcu_read_lock */ 47int br_handle_frame_finish(struct sk_buff *skb) 48{ 49 const unsigned char *dest = eth_hdr(skb)->h_dest; 50 struct net_bridge_port *p = br_port_get_rcu(skb->dev); 51 struct net_bridge *br; 52 struct net_bridge_fdb_entry *dst; 53 struct net_bridge_mdb_entry *mdst; 54 struct sk_buff *skb2; 55 56 if (!p || p->state == BR_STATE_DISABLED) 57 goto drop; 58 59 /* insert into forwarding database after filtering to avoid spoofing */ 60 br = p->br; 61#ifdef HNDCTF 62 br_fdb_update(br, p, eth_hdr(skb)->h_source, skb); 63#else 64 br_fdb_update(br, p, eth_hdr(skb)->h_source); 65#endif 66 67 if (is_multicast_ether_addr(dest) && 68 br_multicast_rcv(br, p, skb)) 69 goto drop; 70 71 if (p->state == BR_STATE_LEARNING) 72 goto drop; 73 74 BR_INPUT_SKB_CB(skb)->brdev = br->dev; 75 76 /* The packet skb2 goes to the local host (NULL to skip). */ 77 skb2 = NULL; 78 79 if (br->dev->flags & IFF_PROMISC) 80 skb2 = skb; 81 82 dst = NULL; 83 84 if (is_multicast_ether_addr(dest)) { 85 mdst = br_mdb_get(br, skb); 86 if (mdst || BR_INPUT_SKB_CB_MROUTERS_ONLY(skb)) { 87 if ((mdst && mdst->mglist) || 88 br_multicast_is_router(br)) 89 skb2 = skb; 90 br_multicast_forward(mdst, skb, skb2); 91 skb = NULL; 92 if (!skb2) 93 goto out; 94 } else 95 skb2 = skb; 96 97 br->dev->stats.multicast++; 98 } else if ((dst = __br_fdb_get(br, dest)) && dst->is_local) { 99 skb2 = skb; 100 /* Do not forward the packet since it's local. */ 101 skb = NULL; 102 } 103 104 if (skb) { 105 if (dst) 106 br_forward(dst->dst, skb, skb2); 107 else 108 br_flood_forward(br, skb, skb2); 109 } 110 111 if (skb2) 112 return br_pass_frame_up(skb2); 113 114out: 115 return 0; 116drop: 117 kfree_skb(skb); 118 goto out; 119} 120 121/* note: already called with rcu_read_lock */ 122static int br_handle_local_finish(struct sk_buff *skb) 123{ 124 struct net_bridge_port *p = br_port_get_rcu(skb->dev); 125 126#ifdef HNDCTF 127 br_fdb_update(p->br, p, eth_hdr(skb)->h_source, skb); 128#else 129 br_fdb_update(p->br, p, eth_hdr(skb)->h_source); 130#endif 131 return 0; /* process further */ 132} 133 134/* Does address match the link local multicast address. 135 * 01:80:c2:00:00:0X 136 */ 137static inline int is_link_local(const unsigned char *dest) 138{ 139 __be16 *a = (__be16 *)dest; 140 static const __be16 *b = (const __be16 *)br_group_address; 141 static const __be16 m = cpu_to_be16(0xfff0); 142 143 return ((a[0] ^ b[0]) | (a[1] ^ b[1]) | ((a[2] ^ b[2]) & m)) == 0; 144} 145 146/* 147 * Return NULL if skb is handled 148 * note: already called with rcu_read_lock 149 */ 150struct sk_buff *br_handle_frame(struct sk_buff *skb) 151{ 152 struct net_bridge_port *p; 153 const unsigned char *dest = eth_hdr(skb)->h_dest; 154 int (*rhook)(struct sk_buff *skb); 155 156 if (skb->pkt_type == PACKET_LOOPBACK) 157 return skb; 158 159 if (!is_valid_ether_addr(eth_hdr(skb)->h_source)) 160 goto drop; 161 162 skb = skb_share_check(skb, GFP_ATOMIC); 163 if (!skb) 164 return NULL; 165 166 p = br_port_get_rcu(skb->dev); 167 168 if (unlikely(is_link_local(dest))) { 169 /* Pause frames shouldn't be passed up by driver anyway */ 170 if (skb->protocol == htons(ETH_P_PAUSE)) 171 goto drop; 172 173 /* If STP is turned off, then forward */ 174 if (p->br->stp_enabled == BR_NO_STP && dest[5] == 0) 175 goto forward; 176 177 if (NF_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_IN, skb, skb->dev, 178 NULL, br_handle_local_finish)) 179 return NULL; /* frame consumed by filter */ 180 else 181 return skb; /* continue processing */ 182 } 183 184forward: 185 switch (p->state) { 186 case BR_STATE_FORWARDING: 187 rhook = rcu_dereference(br_should_route_hook); 188 if (rhook != NULL) { 189 if (rhook(skb)) 190 return skb; 191 dest = eth_hdr(skb)->h_dest; 192 } 193 /* fall through */ 194 case BR_STATE_LEARNING: 195 if (!compare_ether_addr(p->br->dev->dev_addr, dest)) 196 skb->pkt_type = PACKET_HOST; 197 198 NF_HOOK(NFPROTO_BRIDGE, NF_BR_PRE_ROUTING, skb, skb->dev, NULL, 199 br_handle_frame_finish); 200 break; 201 default: 202drop: 203 kfree_skb(skb); 204 } 205 return NULL; 206} 207