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1da177e4 LT |
1 | /* |
2 | * Handle incoming frames | |
3 | * Linux ethernet bridge | |
4 | * | |
5 | * Authors: | |
6 | * Lennert Buytenhek <buytenh@gnu.org> | |
7 | * | |
1da177e4 LT |
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 | ||
5a0e3ad6 | 14 | #include <linux/slab.h> |
1da177e4 LT |
15 | #include <linux/kernel.h> |
16 | #include <linux/netdevice.h> | |
17 | #include <linux/etherdevice.h> | |
18 | #include <linux/netfilter_bridge.h> | |
bc3b2d7f | 19 | #include <linux/export.h> |
a37b85c9 | 20 | #include <linux/rculist.h> |
1da177e4 LT |
21 | #include "br_private.h" |
22 | ||
a386f990 ED |
23 | /* Hook for brouter */ |
24 | br_should_route_hook_t __rcu *br_should_route_hook __read_mostly; | |
25 | EXPORT_SYMBOL(br_should_route_hook); | |
26 | ||
68b7c895 | 27 | static int br_pass_frame_up(struct sk_buff *skb) |
1da177e4 | 28 | { |
68b7c895 | 29 | struct net_device *indev, *brdev = BR_INPUT_SKB_CB(skb)->brdev; |
14bb4789 | 30 | struct net_bridge *br = netdev_priv(brdev); |
31 | struct br_cpu_netstats *brstats = this_cpu_ptr(br->stats); | |
1da177e4 | 32 | |
406818ff | 33 | u64_stats_update_begin(&brstats->syncp); |
14bb4789 | 34 | brstats->rx_packets++; |
35 | brstats->rx_bytes += skb->len; | |
406818ff | 36 | u64_stats_update_end(&brstats->syncp); |
1da177e4 | 37 | |
85f46c6b VY |
38 | /* Bridge is just like any other port. Make sure the |
39 | * packet is allowed except in promisc modue when someone | |
40 | * may be running packet capture. | |
41 | */ | |
42 | if (!(brdev->flags & IFF_PROMISC) && | |
43 | !br_allowed_egress(br, br_get_vlan_info(br), skb)) { | |
44 | kfree_skb(skb); | |
45 | return NET_RX_DROP; | |
46 | } | |
47 | ||
78851988 VY |
48 | skb = br_handle_vlan(br, br_get_vlan_info(br), skb); |
49 | if (!skb) | |
50 | return NET_RX_DROP; | |
51 | ||
1da177e4 | 52 | indev = skb->dev; |
a339f1c8 | 53 | skb->dev = brdev; |
1da177e4 | 54 | |
713aefa3 | 55 | return NF_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_IN, skb, indev, NULL, |
68b7c895 | 56 | netif_receive_skb); |
1da177e4 LT |
57 | } |
58 | ||
eeaf61d8 | 59 | /* note: already called with rcu_read_lock */ |
1da177e4 LT |
60 | int br_handle_frame_finish(struct sk_buff *skb) |
61 | { | |
62 | const unsigned char *dest = eth_hdr(skb)->h_dest; | |
f350a0a8 | 63 | struct net_bridge_port *p = br_port_get_rcu(skb->dev); |
b3f1be4b | 64 | struct net_bridge *br; |
1da177e4 | 65 | struct net_bridge_fdb_entry *dst; |
c4fcb78c | 66 | struct net_bridge_mdb_entry *mdst; |
e081e1e3 | 67 | struct sk_buff *skb2; |
78851988 | 68 | u16 vid = 0; |
1da177e4 | 69 | |
b3f1be4b SH |
70 | if (!p || p->state == BR_STATE_DISABLED) |
71 | goto drop; | |
72 | ||
78851988 | 73 | if (!br_allowed_ingress(p->br, nbp_get_vlan_info(p), skb, &vid)) |
a37b85c9 VY |
74 | goto drop; |
75 | ||
85967bb4 | 76 | /* insert into forwarding database after filtering to avoid spoofing */ |
b3f1be4b SH |
77 | br = p->br; |
78 | br_fdb_update(br, p, eth_hdr(skb)->h_source); | |
85967bb4 | 79 | |
44661462 | 80 | if (!is_broadcast_ether_addr(dest) && is_multicast_ether_addr(dest) && |
c4fcb78c HX |
81 | br_multicast_rcv(br, p, skb)) |
82 | goto drop; | |
83 | ||
b3f1be4b SH |
84 | if (p->state == BR_STATE_LEARNING) |
85 | goto drop; | |
0e5eabac | 86 | |
68b7c895 HX |
87 | BR_INPUT_SKB_CB(skb)->brdev = br->dev; |
88 | ||
e081e1e3 HX |
89 | /* The packet skb2 goes to the local host (NULL to skip). */ |
90 | skb2 = NULL; | |
1da177e4 | 91 | |
e081e1e3 HX |
92 | if (br->dev->flags & IFF_PROMISC) |
93 | skb2 = skb; | |
94 | ||
95 | dst = NULL; | |
1da177e4 | 96 | |
44661462 HX |
97 | if (is_broadcast_ether_addr(dest)) |
98 | skb2 = skb; | |
99 | else if (is_multicast_ether_addr(dest)) { | |
c4fcb78c | 100 | mdst = br_mdb_get(br, skb); |
32dec5dd | 101 | if (mdst || BR_INPUT_SKB_CB_MROUTERS_ONLY(skb)) { |
8a870178 | 102 | if ((mdst && mdst->mglist) || |
c4fcb78c HX |
103 | br_multicast_is_router(br)) |
104 | skb2 = skb; | |
105 | br_multicast_forward(mdst, skb, skb2); | |
106 | skb = NULL; | |
107 | if (!skb2) | |
108 | goto out; | |
109 | } else | |
110 | skb2 = skb; | |
111 | ||
a339f1c8 | 112 | br->dev->stats.multicast++; |
e081e1e3 HX |
113 | } else if ((dst = __br_fdb_get(br, dest)) && dst->is_local) { |
114 | skb2 = skb; | |
115 | /* Do not forward the packet since it's local. */ | |
116 | skb = NULL; | |
1da177e4 LT |
117 | } |
118 | ||
e081e1e3 | 119 | if (skb) { |
7cd8861a | 120 | if (dst) { |
121 | dst->used = jiffies; | |
7f7708f0 | 122 | br_forward(dst->dst, skb, skb2); |
7cd8861a | 123 | } else |
b33084be | 124 | br_flood_forward(br, skb, skb2); |
e081e1e3 | 125 | } |
1da177e4 | 126 | |
87557c18 | 127 | if (skb2) |
68b7c895 | 128 | return br_pass_frame_up(skb2); |
87557c18 | 129 | |
1da177e4 LT |
130 | out: |
131 | return 0; | |
b3f1be4b SH |
132 | drop: |
133 | kfree_skb(skb); | |
134 | goto out; | |
1da177e4 LT |
135 | } |
136 | ||
eeaf61d8 | 137 | /* note: already called with rcu_read_lock */ |
cf0f02d0 SH |
138 | static int br_handle_local_finish(struct sk_buff *skb) |
139 | { | |
f350a0a8 | 140 | struct net_bridge_port *p = br_port_get_rcu(skb->dev); |
cf0f02d0 | 141 | |
f350a0a8 | 142 | br_fdb_update(p->br, p, eth_hdr(skb)->h_source); |
cf0f02d0 SH |
143 | return 0; /* process further */ |
144 | } | |
145 | ||
1da177e4 | 146 | /* |
6229e362 | 147 | * Return NULL if skb is handled |
eeaf61d8 | 148 | * note: already called with rcu_read_lock |
1da177e4 | 149 | */ |
8a4eb573 | 150 | rx_handler_result_t br_handle_frame(struct sk_buff **pskb) |
1da177e4 | 151 | { |
ab95bfe0 | 152 | struct net_bridge_port *p; |
8a4eb573 | 153 | struct sk_buff *skb = *pskb; |
1da177e4 | 154 | const unsigned char *dest = eth_hdr(skb)->h_dest; |
a386f990 | 155 | br_should_route_hook_t *rhook; |
1da177e4 | 156 | |
c2368e79 | 157 | if (unlikely(skb->pkt_type == PACKET_LOOPBACK)) |
8a4eb573 | 158 | return RX_HANDLER_PASS; |
ab95bfe0 | 159 | |
1da177e4 | 160 | if (!is_valid_ether_addr(eth_hdr(skb)->h_source)) |
467aea0d | 161 | goto drop; |
1da177e4 | 162 | |
7b995651 HX |
163 | skb = skb_share_check(skb, GFP_ATOMIC); |
164 | if (!skb) | |
8a4eb573 | 165 | return RX_HANDLER_CONSUMED; |
7b995651 | 166 | |
f350a0a8 | 167 | p = br_port_get_rcu(skb->dev); |
ab95bfe0 | 168 | |
46acc460 | 169 | if (unlikely(is_link_local_ether_addr(dest))) { |
515853cc | 170 | /* |
171 | * See IEEE 802.1D Table 7-10 Reserved addresses | |
172 | * | |
173 | * Assignment Value | |
174 | * Bridge Group Address 01-80-C2-00-00-00 | |
175 | * (MAC Control) 802.3 01-80-C2-00-00-01 | |
176 | * (Link Aggregation) 802.3 01-80-C2-00-00-02 | |
177 | * 802.1X PAE address 01-80-C2-00-00-03 | |
178 | * | |
179 | * 802.1AB LLDP 01-80-C2-00-00-0E | |
180 | * | |
181 | * Others reserved for future standardization | |
182 | */ | |
183 | switch (dest[5]) { | |
184 | case 0x00: /* Bridge Group Address */ | |
185 | /* If STP is turned off, | |
186 | then must forward to keep loop detection */ | |
187 | if (p->br->stp_enabled == BR_NO_STP) | |
188 | goto forward; | |
189 | break; | |
190 | ||
191 | case 0x01: /* IEEE MAC (Pause) */ | |
2111f8b9 SH |
192 | goto drop; |
193 | ||
515853cc | 194 | default: |
195 | /* Allow selective forwarding for most other protocols */ | |
196 | if (p->br->group_fwd_mask & (1u << dest[5])) | |
197 | goto forward; | |
198 | } | |
a598f6ae | 199 | |
515853cc | 200 | /* Deliver packet to local host only */ |
713aefa3 | 201 | if (NF_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_IN, skb, skb->dev, |
8a4eb573 JP |
202 | NULL, br_handle_local_finish)) { |
203 | return RX_HANDLER_CONSUMED; /* consumed by filter */ | |
204 | } else { | |
205 | *pskb = skb; | |
206 | return RX_HANDLER_PASS; /* continue processing */ | |
207 | } | |
2111f8b9 | 208 | } |
1da177e4 | 209 | |
a598f6ae | 210 | forward: |
467aea0d SH |
211 | switch (p->state) { |
212 | case BR_STATE_FORWARDING: | |
82de382c | 213 | rhook = rcu_dereference(br_should_route_hook); |
a386f990 | 214 | if (rhook) { |
8a4eb573 JP |
215 | if ((*rhook)(skb)) { |
216 | *pskb = skb; | |
217 | return RX_HANDLER_PASS; | |
218 | } | |
1da177e4 LT |
219 | dest = eth_hdr(skb)->h_dest; |
220 | } | |
467aea0d SH |
221 | /* fall through */ |
222 | case BR_STATE_LEARNING: | |
9a7b6ef9 | 223 | if (ether_addr_equal(p->br->dev->dev_addr, dest)) |
1da177e4 LT |
224 | skb->pkt_type = PACKET_HOST; |
225 | ||
713aefa3 | 226 | NF_HOOK(NFPROTO_BRIDGE, NF_BR_PRE_ROUTING, skb, skb->dev, NULL, |
1da177e4 | 227 | br_handle_frame_finish); |
467aea0d SH |
228 | break; |
229 | default: | |
230 | drop: | |
231 | kfree_skb(skb); | |
1da177e4 | 232 | } |
8a4eb573 | 233 | return RX_HANDLER_CONSUMED; |
1da177e4 | 234 | } |