Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * Handle firewalling | |
3 | * Linux ethernet bridge | |
4 | * | |
5 | * Authors: | |
8237908e BDS |
6 | * Lennert Buytenhek <buytenh@gnu.org> |
7 | * Bart De Schuymer <bdschuym@pandora.be> | |
1da177e4 LT |
8 | * |
9 | * This program is free software; you can redistribute it and/or | |
10 | * modify it under the terms of the GNU General Public License | |
11 | * as published by the Free Software Foundation; either version | |
12 | * 2 of the License, or (at your option) any later version. | |
13 | * | |
14 | * Lennert dedicates this file to Kerstin Wurdinger. | |
15 | */ | |
16 | ||
17 | #include <linux/module.h> | |
18 | #include <linux/kernel.h> | |
5a0e3ad6 | 19 | #include <linux/slab.h> |
1da177e4 LT |
20 | #include <linux/ip.h> |
21 | #include <linux/netdevice.h> | |
22 | #include <linux/skbuff.h> | |
14c85021 | 23 | #include <linux/if_arp.h> |
1da177e4 LT |
24 | #include <linux/if_ether.h> |
25 | #include <linux/if_vlan.h> | |
516299d2 MM |
26 | #include <linux/if_pppox.h> |
27 | #include <linux/ppp_defs.h> | |
1da177e4 LT |
28 | #include <linux/netfilter_bridge.h> |
29 | #include <linux/netfilter_ipv4.h> | |
30 | #include <linux/netfilter_ipv6.h> | |
31 | #include <linux/netfilter_arp.h> | |
32 | #include <linux/in_route.h> | |
f216f082 | 33 | #include <linux/inetdevice.h> |
14c85021 | 34 | |
1da177e4 LT |
35 | #include <net/ip.h> |
36 | #include <net/ipv6.h> | |
14c85021 | 37 | #include <net/route.h> |
56768644 | 38 | #include <net/netfilter/br_netfilter.h> |
14c85021 | 39 | |
c055d5b0 FW |
40 | #if IS_ENABLED(CONFIG_NF_CONNTRACK) |
41 | #include <net/netfilter/nf_conntrack.h> | |
42 | #endif | |
43 | ||
1da177e4 | 44 | #include <asm/uaccess.h> |
1da177e4 LT |
45 | #include "br_private.h" |
46 | #ifdef CONFIG_SYSCTL | |
47 | #include <linux/sysctl.h> | |
48 | #endif | |
49 | ||
1da177e4 LT |
50 | #ifdef CONFIG_SYSCTL |
51 | static struct ctl_table_header *brnf_sysctl_header; | |
9c1ea148 BH |
52 | static int brnf_call_iptables __read_mostly = 1; |
53 | static int brnf_call_ip6tables __read_mostly = 1; | |
54 | static int brnf_call_arptables __read_mostly = 1; | |
47e0e1ca HX |
55 | static int brnf_filter_vlan_tagged __read_mostly = 0; |
56 | static int brnf_filter_pppoe_tagged __read_mostly = 0; | |
4981682c | 57 | static int brnf_pass_vlan_indev __read_mostly = 0; |
1da177e4 | 58 | #else |
4df53d8b PM |
59 | #define brnf_call_iptables 1 |
60 | #define brnf_call_ip6tables 1 | |
61 | #define brnf_call_arptables 1 | |
47e0e1ca HX |
62 | #define brnf_filter_vlan_tagged 0 |
63 | #define brnf_filter_pppoe_tagged 0 | |
4981682c | 64 | #define brnf_pass_vlan_indev 0 |
1da177e4 LT |
65 | #endif |
66 | ||
739e4505 | 67 | #define IS_IP(skb) \ |
df8a39de | 68 | (!skb_vlan_tag_present(skb) && skb->protocol == htons(ETH_P_IP)) |
739e4505 FW |
69 | |
70 | #define IS_IPV6(skb) \ | |
df8a39de | 71 | (!skb_vlan_tag_present(skb) && skb->protocol == htons(ETH_P_IPV6)) |
739e4505 FW |
72 | |
73 | #define IS_ARP(skb) \ | |
df8a39de | 74 | (!skb_vlan_tag_present(skb) && skb->protocol == htons(ETH_P_ARP)) |
739e4505 | 75 | |
b6f99a21 | 76 | static inline __be16 vlan_proto(const struct sk_buff *skb) |
8b42ec39 | 77 | { |
df8a39de | 78 | if (skb_vlan_tag_present(skb)) |
13937911 JG |
79 | return skb->protocol; |
80 | else if (skb->protocol == htons(ETH_P_8021Q)) | |
81 | return vlan_eth_hdr(skb)->h_vlan_encapsulated_proto; | |
82 | else | |
83 | return 0; | |
8b42ec39 SH |
84 | } |
85 | ||
86 | #define IS_VLAN_IP(skb) \ | |
13937911 | 87 | (vlan_proto(skb) == htons(ETH_P_IP) && \ |
8b42ec39 SH |
88 | brnf_filter_vlan_tagged) |
89 | ||
90 | #define IS_VLAN_IPV6(skb) \ | |
13937911 | 91 | (vlan_proto(skb) == htons(ETH_P_IPV6) && \ |
8b42ec39 SH |
92 | brnf_filter_vlan_tagged) |
93 | ||
94 | #define IS_VLAN_ARP(skb) \ | |
13937911 | 95 | (vlan_proto(skb) == htons(ETH_P_ARP) && \ |
8b42ec39 | 96 | brnf_filter_vlan_tagged) |
1da177e4 | 97 | |
516299d2 MM |
98 | static inline __be16 pppoe_proto(const struct sk_buff *skb) |
99 | { | |
100 | return *((__be16 *)(skb_mac_header(skb) + ETH_HLEN + | |
101 | sizeof(struct pppoe_hdr))); | |
102 | } | |
103 | ||
104 | #define IS_PPPOE_IP(skb) \ | |
105 | (skb->protocol == htons(ETH_P_PPP_SES) && \ | |
106 | pppoe_proto(skb) == htons(PPP_IP) && \ | |
107 | brnf_filter_pppoe_tagged) | |
108 | ||
109 | #define IS_PPPOE_IPV6(skb) \ | |
110 | (skb->protocol == htons(ETH_P_PPP_SES) && \ | |
111 | pppoe_proto(skb) == htons(PPP_IPV6) && \ | |
112 | brnf_filter_pppoe_tagged) | |
113 | ||
e70deecb FW |
114 | /* largest possible L2 header, see br_nf_dev_queue_xmit() */ |
115 | #define NF_BRIDGE_MAX_MAC_HEADER_LENGTH (PPPOE_SES_HLEN + ETH_HLEN) | |
116 | ||
117 | #if IS_ENABLED(CONFIG_NF_DEFRAG_IPV4) | |
118 | struct brnf_frag_data { | |
119 | char mac[NF_BRIDGE_MAX_MAC_HEADER_LENGTH]; | |
120 | u8 encap_size; | |
121 | u8 size; | |
122 | }; | |
123 | ||
124 | static DEFINE_PER_CPU(struct brnf_frag_data, brnf_frag_data_storage); | |
125 | #endif | |
126 | ||
38330783 FW |
127 | static struct nf_bridge_info *nf_bridge_info_get(const struct sk_buff *skb) |
128 | { | |
129 | return skb->nf_bridge; | |
130 | } | |
131 | ||
4adf0af6 SW |
132 | static inline struct rtable *bridge_parent_rtable(const struct net_device *dev) |
133 | { | |
b5ed54e9 | 134 | struct net_bridge_port *port; |
135 | ||
136 | port = br_port_get_rcu(dev); | |
137 | return port ? &port->br->fake_rtable : NULL; | |
4adf0af6 | 138 | } |
1da177e4 | 139 | |
5dce971a SH |
140 | static inline struct net_device *bridge_parent(const struct net_device *dev) |
141 | { | |
b5ed54e9 | 142 | struct net_bridge_port *port; |
5dce971a | 143 | |
b5ed54e9 | 144 | port = br_port_get_rcu(dev); |
145 | return port ? port->br->dev : NULL; | |
5dce971a | 146 | } |
1da177e4 | 147 | |
fdeabdef SH |
148 | static inline struct nf_bridge_info *nf_bridge_alloc(struct sk_buff *skb) |
149 | { | |
150 | skb->nf_bridge = kzalloc(sizeof(struct nf_bridge_info), GFP_ATOMIC); | |
151 | if (likely(skb->nf_bridge)) | |
152 | atomic_set(&(skb->nf_bridge->use), 1); | |
153 | ||
154 | return skb->nf_bridge; | |
155 | } | |
156 | ||
2dc2f207 PM |
157 | static inline struct nf_bridge_info *nf_bridge_unshare(struct sk_buff *skb) |
158 | { | |
159 | struct nf_bridge_info *nf_bridge = skb->nf_bridge; | |
160 | ||
161 | if (atomic_read(&nf_bridge->use) > 1) { | |
162 | struct nf_bridge_info *tmp = nf_bridge_alloc(skb); | |
163 | ||
164 | if (tmp) { | |
165 | memcpy(tmp, nf_bridge, sizeof(struct nf_bridge_info)); | |
166 | atomic_set(&tmp->use, 1); | |
2dc2f207 | 167 | } |
4c3a76ab | 168 | nf_bridge_put(nf_bridge); |
2dc2f207 PM |
169 | nf_bridge = tmp; |
170 | } | |
171 | return nf_bridge; | |
172 | } | |
173 | ||
8d045163 FW |
174 | static unsigned int nf_bridge_encap_header_len(const struct sk_buff *skb) |
175 | { | |
176 | switch (skb->protocol) { | |
177 | case __cpu_to_be16(ETH_P_8021Q): | |
178 | return VLAN_HLEN; | |
179 | case __cpu_to_be16(ETH_P_PPP_SES): | |
180 | return PPPOE_SES_HLEN; | |
181 | default: | |
182 | return 0; | |
183 | } | |
184 | } | |
185 | ||
fc38582d PM |
186 | static inline void nf_bridge_push_encap_header(struct sk_buff *skb) |
187 | { | |
188 | unsigned int len = nf_bridge_encap_header_len(skb); | |
189 | ||
190 | skb_push(skb, len); | |
191 | skb->network_header -= len; | |
192 | } | |
193 | ||
194 | static inline void nf_bridge_pull_encap_header(struct sk_buff *skb) | |
fdeabdef | 195 | { |
fc38582d PM |
196 | unsigned int len = nf_bridge_encap_header_len(skb); |
197 | ||
198 | skb_pull(skb, len); | |
199 | skb->network_header += len; | |
200 | } | |
fdeabdef | 201 | |
fc38582d PM |
202 | static inline void nf_bridge_pull_encap_header_rcsum(struct sk_buff *skb) |
203 | { | |
204 | unsigned int len = nf_bridge_encap_header_len(skb); | |
205 | ||
206 | skb_pull_rcsum(skb, len); | |
207 | skb->network_header += len; | |
208 | } | |
209 | ||
462fb2af BD |
210 | /* When handing a packet over to the IP layer |
211 | * check whether we have a skb that is in the | |
212 | * expected format | |
213 | */ | |
214 | ||
d0280232 | 215 | static int br_parse_ip_options(struct sk_buff *skb) |
462fb2af | 216 | { |
b71d1d42 | 217 | const struct iphdr *iph; |
462fb2af BD |
218 | struct net_device *dev = skb->dev; |
219 | u32 len; | |
220 | ||
6caab7b0 SB |
221 | if (!pskb_may_pull(skb, sizeof(struct iphdr))) |
222 | goto inhdr_error; | |
223 | ||
462fb2af | 224 | iph = ip_hdr(skb); |
462fb2af BD |
225 | |
226 | /* Basic sanity checks */ | |
227 | if (iph->ihl < 5 || iph->version != 4) | |
228 | goto inhdr_error; | |
229 | ||
230 | if (!pskb_may_pull(skb, iph->ihl*4)) | |
231 | goto inhdr_error; | |
232 | ||
233 | iph = ip_hdr(skb); | |
234 | if (unlikely(ip_fast_csum((u8 *)iph, iph->ihl))) | |
235 | goto inhdr_error; | |
236 | ||
237 | len = ntohs(iph->tot_len); | |
238 | if (skb->len < len) { | |
239 | IP_INC_STATS_BH(dev_net(dev), IPSTATS_MIB_INTRUNCATEDPKTS); | |
240 | goto drop; | |
241 | } else if (len < (iph->ihl*4)) | |
242 | goto inhdr_error; | |
243 | ||
244 | if (pskb_trim_rcsum(skb, len)) { | |
245 | IP_INC_STATS_BH(dev_net(dev), IPSTATS_MIB_INDISCARDS); | |
246 | goto drop; | |
247 | } | |
248 | ||
f8e9881c | 249 | memset(IPCB(skb), 0, sizeof(struct inet_skb_parm)); |
7677e868 HX |
250 | /* We should really parse IP options here but until |
251 | * somebody who actually uses IP options complains to | |
252 | * us we'll just silently ignore the options because | |
253 | * we're lazy! | |
254 | */ | |
462fb2af BD |
255 | return 0; |
256 | ||
257 | inhdr_error: | |
258 | IP_INC_STATS_BH(dev_net(dev), IPSTATS_MIB_INHDRERRORS); | |
259 | drop: | |
260 | return -1; | |
261 | } | |
262 | ||
4a9d2f20 FW |
263 | static void nf_bridge_update_protocol(struct sk_buff *skb) |
264 | { | |
265 | if (skb->nf_bridge->mask & BRNF_8021Q) | |
266 | skb->protocol = htons(ETH_P_8021Q); | |
267 | else if (skb->nf_bridge->mask & BRNF_PPPoE) | |
268 | skb->protocol = htons(ETH_P_PPP_SES); | |
269 | } | |
270 | ||
1da177e4 LT |
271 | /* PF_BRIDGE/PRE_ROUTING *********************************************/ |
272 | /* Undo the changes made for ip6tables PREROUTING and continue the | |
273 | * bridge PRE_ROUTING hook. */ | |
274 | static int br_nf_pre_routing_finish_ipv6(struct sk_buff *skb) | |
275 | { | |
38330783 | 276 | struct nf_bridge_info *nf_bridge = nf_bridge_info_get(skb); |
511c3f92 | 277 | struct rtable *rt; |
1da177e4 | 278 | |
1da177e4 LT |
279 | if (nf_bridge->mask & BRNF_PKT_TYPE) { |
280 | skb->pkt_type = PACKET_OTHERHOST; | |
281 | nf_bridge->mask ^= BRNF_PKT_TYPE; | |
282 | } | |
283 | nf_bridge->mask ^= BRNF_NF_BRIDGE_PREROUTING; | |
284 | ||
511c3f92 ED |
285 | rt = bridge_parent_rtable(nf_bridge->physindev); |
286 | if (!rt) { | |
4adf0af6 SW |
287 | kfree_skb(skb); |
288 | return 0; | |
289 | } | |
f9181f4f | 290 | skb_dst_set_noref(skb, &rt->dst); |
1da177e4 LT |
291 | |
292 | skb->dev = nf_bridge->physindev; | |
e179e632 | 293 | nf_bridge_update_protocol(skb); |
fc38582d | 294 | nf_bridge_push_encap_header(skb); |
713aefa3 | 295 | NF_HOOK_THRESH(NFPROTO_BRIDGE, NF_BR_PRE_ROUTING, skb, skb->dev, NULL, |
1da177e4 LT |
296 | br_handle_frame_finish, 1); |
297 | ||
298 | return 0; | |
299 | } | |
300 | ||
e179e632 BDS |
301 | /* Obtain the correct destination MAC address, while preserving the original |
302 | * source MAC address. If we already know this address, we just copy it. If we | |
303 | * don't, we use the neighbour framework to find out. In both cases, we make | |
304 | * sure that br_handle_frame_finish() is called afterwards. | |
305 | */ | |
306 | static int br_nf_pre_routing_finish_bridge(struct sk_buff *skb) | |
307 | { | |
f6b72b62 | 308 | struct neighbour *neigh; |
e179e632 BDS |
309 | struct dst_entry *dst; |
310 | ||
311 | skb->dev = bridge_parent(skb->dev); | |
312 | if (!skb->dev) | |
313 | goto free_skb; | |
314 | dst = skb_dst(skb); | |
f9d75166 DM |
315 | neigh = dst_neigh_lookup_skb(dst, skb); |
316 | if (neigh) { | |
38330783 | 317 | struct nf_bridge_info *nf_bridge = nf_bridge_info_get(skb); |
f9d75166 DM |
318 | int ret; |
319 | ||
320 | if (neigh->hh.hh_len) { | |
321 | neigh_hh_bridge(&neigh->hh, skb); | |
322 | skb->dev = nf_bridge->physindev; | |
323 | ret = br_handle_frame_finish(skb); | |
324 | } else { | |
325 | /* the neighbour function below overwrites the complete | |
326 | * MAC header, so we save the Ethernet source address and | |
327 | * protocol number. | |
328 | */ | |
329 | skb_copy_from_linear_data_offset(skb, | |
330 | -(ETH_HLEN-ETH_ALEN), | |
e70deecb | 331 | nf_bridge->neigh_header, |
f9d75166 DM |
332 | ETH_HLEN-ETH_ALEN); |
333 | /* tell br_dev_xmit to continue with forwarding */ | |
334 | nf_bridge->mask |= BRNF_BRIDGED_DNAT; | |
93fdd47e | 335 | /* FIXME Need to refragment */ |
f9d75166 DM |
336 | ret = neigh->output(neigh, skb); |
337 | } | |
338 | neigh_release(neigh); | |
339 | return ret; | |
e179e632 BDS |
340 | } |
341 | free_skb: | |
342 | kfree_skb(skb); | |
343 | return 0; | |
344 | } | |
345 | ||
c055d5b0 FW |
346 | static bool dnat_took_place(const struct sk_buff *skb) |
347 | { | |
348 | #if IS_ENABLED(CONFIG_NF_CONNTRACK) | |
349 | enum ip_conntrack_info ctinfo; | |
350 | struct nf_conn *ct; | |
351 | ||
352 | ct = nf_ct_get(skb, &ctinfo); | |
353 | if (!ct || nf_ct_is_untracked(ct)) | |
354 | return false; | |
355 | ||
356 | return test_bit(IPS_DST_NAT_BIT, &ct->status); | |
357 | #else | |
358 | return false; | |
359 | #endif | |
360 | } | |
361 | ||
1da177e4 | 362 | /* This requires some explaining. If DNAT has taken place, |
ea2d9b41 | 363 | * we will need to fix up the destination Ethernet address. |
1da177e4 LT |
364 | * |
365 | * There are two cases to consider: | |
366 | * 1. The packet was DNAT'ed to a device in the same bridge | |
367 | * port group as it was received on. We can still bridge | |
368 | * the packet. | |
369 | * 2. The packet was DNAT'ed to a different device, either | |
370 | * a non-bridged device or another bridge port group. | |
371 | * The packet will need to be routed. | |
372 | * | |
373 | * The correct way of distinguishing between these two cases is to | |
374 | * call ip_route_input() and to look at skb->dst->dev, which is | |
375 | * changed to the destination device if ip_route_input() succeeds. | |
376 | * | |
ea2d9b41 | 377 | * Let's first consider the case that ip_route_input() succeeds: |
1da177e4 | 378 | * |
ea2d9b41 BDS |
379 | * If the output device equals the logical bridge device the packet |
380 | * came in on, we can consider this bridging. The corresponding MAC | |
381 | * address will be obtained in br_nf_pre_routing_finish_bridge. | |
1da177e4 LT |
382 | * Otherwise, the packet is considered to be routed and we just |
383 | * change the destination MAC address so that the packet will | |
f216f082 BDS |
384 | * later be passed up to the IP stack to be routed. For a redirected |
385 | * packet, ip_route_input() will give back the localhost as output device, | |
386 | * which differs from the bridge device. | |
1da177e4 | 387 | * |
ea2d9b41 | 388 | * Let's now consider the case that ip_route_input() fails: |
1da177e4 | 389 | * |
f216f082 BDS |
390 | * This can be because the destination address is martian, in which case |
391 | * the packet will be dropped. | |
ea2d9b41 BDS |
392 | * If IP forwarding is disabled, ip_route_input() will fail, while |
393 | * ip_route_output_key() can return success. The source | |
394 | * address for ip_route_output_key() is set to zero, so ip_route_output_key() | |
1da177e4 | 395 | * thinks we're handling a locally generated packet and won't care |
ea2d9b41 BDS |
396 | * if IP forwarding is enabled. If the output device equals the logical bridge |
397 | * device, we proceed as if ip_route_input() succeeded. If it differs from the | |
398 | * logical bridge port or if ip_route_output_key() fails we drop the packet. | |
399 | */ | |
1da177e4 LT |
400 | static int br_nf_pre_routing_finish(struct sk_buff *skb) |
401 | { | |
402 | struct net_device *dev = skb->dev; | |
eddc9ec5 | 403 | struct iphdr *iph = ip_hdr(skb); |
38330783 | 404 | struct nf_bridge_info *nf_bridge = nf_bridge_info_get(skb); |
511c3f92 | 405 | struct rtable *rt; |
f216f082 | 406 | int err; |
93fdd47e HX |
407 | int frag_max_size; |
408 | ||
409 | frag_max_size = IPCB(skb)->frag_max_size; | |
410 | BR_INPUT_SKB_CB(skb)->frag_max_size = frag_max_size; | |
1da177e4 | 411 | |
1da177e4 LT |
412 | if (nf_bridge->mask & BRNF_PKT_TYPE) { |
413 | skb->pkt_type = PACKET_OTHERHOST; | |
414 | nf_bridge->mask ^= BRNF_PKT_TYPE; | |
415 | } | |
416 | nf_bridge->mask ^= BRNF_NF_BRIDGE_PREROUTING; | |
1da177e4 | 417 | if (dnat_took_place(skb)) { |
f216f082 | 418 | if ((err = ip_route_input(skb, iph->daddr, iph->saddr, iph->tos, dev))) { |
f3abc9b9 | 419 | struct in_device *in_dev = __in_dev_get_rcu(dev); |
f216f082 BDS |
420 | |
421 | /* If err equals -EHOSTUNREACH the error is due to a | |
422 | * martian destination or due to the fact that | |
423 | * forwarding is disabled. For most martian packets, | |
424 | * ip_route_output_key() will fail. It won't fail for 2 types of | |
425 | * martian destinations: loopback destinations and destination | |
426 | * 0.0.0.0. In both cases the packet will be dropped because the | |
427 | * destination is the loopback device and not the bridge. */ | |
428 | if (err != -EHOSTUNREACH || !in_dev || IN_DEV_FORWARD(in_dev)) | |
429 | goto free_skb; | |
1da177e4 | 430 | |
78fbfd8a DM |
431 | rt = ip_route_output(dev_net(dev), iph->daddr, 0, |
432 | RT_TOS(iph->tos), 0); | |
b23dd4fe | 433 | if (!IS_ERR(rt)) { |
1c011bed | 434 | /* - Bridged-and-DNAT'ed traffic doesn't |
f216f082 | 435 | * require ip_forwarding. */ |
b23dd4fe DM |
436 | if (rt->dst.dev == dev) { |
437 | skb_dst_set(skb, &rt->dst); | |
1da177e4 LT |
438 | goto bridged_dnat; |
439 | } | |
b23dd4fe | 440 | ip_rt_put(rt); |
1da177e4 | 441 | } |
f216f082 | 442 | free_skb: |
1da177e4 LT |
443 | kfree_skb(skb); |
444 | return 0; | |
445 | } else { | |
adf30907 | 446 | if (skb_dst(skb)->dev == dev) { |
1da177e4 | 447 | bridged_dnat: |
1da177e4 | 448 | skb->dev = nf_bridge->physindev; |
e179e632 | 449 | nf_bridge_update_protocol(skb); |
fc38582d | 450 | nf_bridge_push_encap_header(skb); |
713aefa3 JE |
451 | NF_HOOK_THRESH(NFPROTO_BRIDGE, |
452 | NF_BR_PRE_ROUTING, | |
1da177e4 LT |
453 | skb, skb->dev, NULL, |
454 | br_nf_pre_routing_finish_bridge, | |
455 | 1); | |
456 | return 0; | |
457 | } | |
04091142 | 458 | ether_addr_copy(eth_hdr(skb)->h_dest, dev->dev_addr); |
1da177e4 LT |
459 | skb->pkt_type = PACKET_HOST; |
460 | } | |
461 | } else { | |
511c3f92 ED |
462 | rt = bridge_parent_rtable(nf_bridge->physindev); |
463 | if (!rt) { | |
4adf0af6 SW |
464 | kfree_skb(skb); |
465 | return 0; | |
466 | } | |
f9181f4f | 467 | skb_dst_set_noref(skb, &rt->dst); |
1da177e4 LT |
468 | } |
469 | ||
470 | skb->dev = nf_bridge->physindev; | |
e179e632 | 471 | nf_bridge_update_protocol(skb); |
fc38582d | 472 | nf_bridge_push_encap_header(skb); |
713aefa3 | 473 | NF_HOOK_THRESH(NFPROTO_BRIDGE, NF_BR_PRE_ROUTING, skb, skb->dev, NULL, |
1da177e4 LT |
474 | br_handle_frame_finish, 1); |
475 | ||
476 | return 0; | |
477 | } | |
478 | ||
4981682c PNA |
479 | static struct net_device *brnf_get_logical_dev(struct sk_buff *skb, const struct net_device *dev) |
480 | { | |
481 | struct net_device *vlan, *br; | |
482 | ||
483 | br = bridge_parent(dev); | |
df8a39de | 484 | if (brnf_pass_vlan_indev == 0 || !skb_vlan_tag_present(skb)) |
4981682c PNA |
485 | return br; |
486 | ||
f06c7f9f | 487 | vlan = __vlan_find_dev_deep_rcu(br, skb->vlan_proto, |
df8a39de | 488 | skb_vlan_tag_get(skb) & VLAN_VID_MASK); |
4981682c PNA |
489 | |
490 | return vlan ? vlan : br; | |
491 | } | |
492 | ||
1da177e4 | 493 | /* Some common code for IPv4/IPv6 */ |
5dce971a | 494 | static struct net_device *setup_pre_routing(struct sk_buff *skb) |
1da177e4 | 495 | { |
38330783 | 496 | struct nf_bridge_info *nf_bridge = nf_bridge_info_get(skb); |
1da177e4 LT |
497 | |
498 | if (skb->pkt_type == PACKET_OTHERHOST) { | |
499 | skb->pkt_type = PACKET_HOST; | |
500 | nf_bridge->mask |= BRNF_PKT_TYPE; | |
501 | } | |
502 | ||
503 | nf_bridge->mask |= BRNF_NF_BRIDGE_PREROUTING; | |
504 | nf_bridge->physindev = skb->dev; | |
4981682c | 505 | skb->dev = brnf_get_logical_dev(skb, skb->dev); |
e179e632 BDS |
506 | if (skb->protocol == htons(ETH_P_8021Q)) |
507 | nf_bridge->mask |= BRNF_8021Q; | |
508 | else if (skb->protocol == htons(ETH_P_PPP_SES)) | |
509 | nf_bridge->mask |= BRNF_PPPoE; | |
5dce971a | 510 | |
6b8dbcf2 FW |
511 | /* Must drop socket now because of tproxy. */ |
512 | skb_orphan(skb); | |
5dce971a | 513 | return skb->dev; |
1da177e4 LT |
514 | } |
515 | ||
516 | /* We only check the length. A bridge shouldn't do any hop-by-hop stuff anyway */ | |
517 | static int check_hbh_len(struct sk_buff *skb) | |
518 | { | |
0660e03f | 519 | unsigned char *raw = (u8 *)(ipv6_hdr(skb) + 1); |
1da177e4 | 520 | u32 pkt_len; |
d56f90a7 ACM |
521 | const unsigned char *nh = skb_network_header(skb); |
522 | int off = raw - nh; | |
789bc3e5 | 523 | int len = (raw[1] + 1) << 3; |
1da177e4 LT |
524 | |
525 | if ((raw + len) - skb->data > skb_headlen(skb)) | |
526 | goto bad; | |
527 | ||
528 | off += 2; | |
529 | len -= 2; | |
530 | ||
531 | while (len > 0) { | |
d56f90a7 | 532 | int optlen = nh[off + 1] + 2; |
1da177e4 | 533 | |
d56f90a7 | 534 | switch (nh[off]) { |
1de5a71c | 535 | case IPV6_TLV_PAD1: |
1da177e4 LT |
536 | optlen = 1; |
537 | break; | |
538 | ||
539 | case IPV6_TLV_PADN: | |
540 | break; | |
541 | ||
542 | case IPV6_TLV_JUMBO: | |
d56f90a7 | 543 | if (nh[off + 1] != 4 || (off & 3) != 2) |
1da177e4 | 544 | goto bad; |
d56f90a7 | 545 | pkt_len = ntohl(*(__be32 *) (nh + off + 2)); |
b0366486 | 546 | if (pkt_len <= IPV6_MAXPLEN || |
0660e03f | 547 | ipv6_hdr(skb)->payload_len) |
b0366486 | 548 | goto bad; |
1da177e4 LT |
549 | if (pkt_len > skb->len - sizeof(struct ipv6hdr)) |
550 | goto bad; | |
b0366486 | 551 | if (pskb_trim_rcsum(skb, |
789bc3e5 | 552 | pkt_len + sizeof(struct ipv6hdr))) |
b0366486 | 553 | goto bad; |
d56f90a7 | 554 | nh = skb_network_header(skb); |
1da177e4 LT |
555 | break; |
556 | default: | |
557 | if (optlen > len) | |
558 | goto bad; | |
559 | break; | |
560 | } | |
561 | off += optlen; | |
562 | len -= optlen; | |
563 | } | |
564 | if (len == 0) | |
565 | return 0; | |
566 | bad: | |
567 | return -1; | |
568 | ||
569 | } | |
570 | ||
571 | /* Replicate the checks that IPv6 does on packet reception and pass the packet | |
572 | * to ip6tables, which doesn't support NAT, so things are fairly simple. */ | |
795aa6ef | 573 | static unsigned int br_nf_pre_routing_ipv6(const struct nf_hook_ops *ops, |
789bc3e5 SH |
574 | struct sk_buff *skb, |
575 | const struct net_device *in, | |
576 | const struct net_device *out, | |
577 | int (*okfn)(struct sk_buff *)) | |
1da177e4 | 578 | { |
b71d1d42 | 579 | const struct ipv6hdr *hdr; |
1da177e4 | 580 | u32 pkt_len; |
1da177e4 LT |
581 | |
582 | if (skb->len < sizeof(struct ipv6hdr)) | |
deef4b52 | 583 | return NF_DROP; |
1da177e4 LT |
584 | |
585 | if (!pskb_may_pull(skb, sizeof(struct ipv6hdr))) | |
deef4b52 | 586 | return NF_DROP; |
1da177e4 | 587 | |
0660e03f | 588 | hdr = ipv6_hdr(skb); |
1da177e4 LT |
589 | |
590 | if (hdr->version != 6) | |
deef4b52 | 591 | return NF_DROP; |
1da177e4 LT |
592 | |
593 | pkt_len = ntohs(hdr->payload_len); | |
594 | ||
595 | if (pkt_len || hdr->nexthdr != NEXTHDR_HOP) { | |
596 | if (pkt_len + sizeof(struct ipv6hdr) > skb->len) | |
deef4b52 | 597 | return NF_DROP; |
b38dfee3 | 598 | if (pskb_trim_rcsum(skb, pkt_len + sizeof(struct ipv6hdr))) |
deef4b52 | 599 | return NF_DROP; |
1da177e4 LT |
600 | } |
601 | if (hdr->nexthdr == NEXTHDR_HOP && check_hbh_len(skb)) | |
deef4b52 | 602 | return NF_DROP; |
1da177e4 | 603 | |
789bc3e5 | 604 | nf_bridge_put(skb->nf_bridge); |
fdeabdef | 605 | if (!nf_bridge_alloc(skb)) |
1da177e4 | 606 | return NF_DROP; |
5dce971a SH |
607 | if (!setup_pre_routing(skb)) |
608 | return NF_DROP; | |
1da177e4 | 609 | |
e179e632 | 610 | skb->protocol = htons(ETH_P_IPV6); |
713aefa3 | 611 | NF_HOOK(NFPROTO_IPV6, NF_INET_PRE_ROUTING, skb, skb->dev, NULL, |
1da177e4 LT |
612 | br_nf_pre_routing_finish_ipv6); |
613 | ||
614 | return NF_STOLEN; | |
1da177e4 LT |
615 | } |
616 | ||
617 | /* Direct IPv6 traffic to br_nf_pre_routing_ipv6. | |
618 | * Replicate the checks that IPv4 does on packet reception. | |
619 | * Set skb->dev to the bridge device (i.e. parent of the | |
620 | * receiving device) to make netfilter happy, the REDIRECT | |
621 | * target in particular. Save the original destination IP | |
622 | * address to be able to detect DNAT afterwards. */ | |
795aa6ef PM |
623 | static unsigned int br_nf_pre_routing(const struct nf_hook_ops *ops, |
624 | struct sk_buff *skb, | |
ee02b3a6 SH |
625 | const struct net_device *in, |
626 | const struct net_device *out, | |
627 | int (*okfn)(struct sk_buff *)) | |
1da177e4 | 628 | { |
4df53d8b PM |
629 | struct net_bridge_port *p; |
630 | struct net_bridge *br; | |
e7c243c9 EP |
631 | __u32 len = nf_bridge_encap_header_len(skb); |
632 | ||
e7c243c9 | 633 | if (unlikely(!pskb_may_pull(skb, len))) |
deef4b52 | 634 | return NF_DROP; |
1da177e4 | 635 | |
e490c1de | 636 | p = br_port_get_rcu(in); |
4df53d8b | 637 | if (p == NULL) |
deef4b52 | 638 | return NF_DROP; |
4df53d8b PM |
639 | br = p->br; |
640 | ||
739e4505 | 641 | if (IS_IPV6(skb) || IS_VLAN_IPV6(skb) || IS_PPPOE_IPV6(skb)) { |
4df53d8b | 642 | if (!brnf_call_ip6tables && !br->nf_call_ip6tables) |
1da177e4 | 643 | return NF_ACCEPT; |
4df53d8b | 644 | |
fc38582d | 645 | nf_bridge_pull_encap_header_rcsum(skb); |
795aa6ef | 646 | return br_nf_pre_routing_ipv6(ops, skb, in, out, okfn); |
1da177e4 | 647 | } |
4df53d8b PM |
648 | |
649 | if (!brnf_call_iptables && !br->nf_call_iptables) | |
1da177e4 | 650 | return NF_ACCEPT; |
1da177e4 | 651 | |
739e4505 | 652 | if (!IS_IP(skb) && !IS_VLAN_IP(skb) && !IS_PPPOE_IP(skb)) |
1da177e4 LT |
653 | return NF_ACCEPT; |
654 | ||
fc38582d | 655 | nf_bridge_pull_encap_header_rcsum(skb); |
1da177e4 | 656 | |
462fb2af | 657 | if (br_parse_ip_options(skb)) |
deef4b52 | 658 | return NF_DROP; |
17762060 | 659 | |
789bc3e5 | 660 | nf_bridge_put(skb->nf_bridge); |
fdeabdef | 661 | if (!nf_bridge_alloc(skb)) |
1da177e4 | 662 | return NF_DROP; |
5dce971a SH |
663 | if (!setup_pre_routing(skb)) |
664 | return NF_DROP; | |
c055d5b0 | 665 | |
e179e632 | 666 | skb->protocol = htons(ETH_P_IP); |
1da177e4 | 667 | |
713aefa3 | 668 | NF_HOOK(NFPROTO_IPV4, NF_INET_PRE_ROUTING, skb, skb->dev, NULL, |
1da177e4 LT |
669 | br_nf_pre_routing_finish); |
670 | ||
671 | return NF_STOLEN; | |
1da177e4 LT |
672 | } |
673 | ||
674 | ||
675 | /* PF_BRIDGE/LOCAL_IN ************************************************/ | |
676 | /* The packet is locally destined, which requires a real | |
677 | * dst_entry, so detach the fake one. On the way up, the | |
678 | * packet would pass through PRE_ROUTING again (which already | |
679 | * took place when the packet entered the bridge), but we | |
680 | * register an IPv4 PRE_ROUTING 'sabotage' hook that will | |
681 | * prevent this from happening. */ | |
795aa6ef PM |
682 | static unsigned int br_nf_local_in(const struct nf_hook_ops *ops, |
683 | struct sk_buff *skb, | |
789bc3e5 SH |
684 | const struct net_device *in, |
685 | const struct net_device *out, | |
686 | int (*okfn)(struct sk_buff *)) | |
1da177e4 | 687 | { |
a881e963 | 688 | br_drop_fake_rtable(skb); |
1da177e4 LT |
689 | return NF_ACCEPT; |
690 | } | |
691 | ||
1da177e4 LT |
692 | /* PF_BRIDGE/FORWARD *************************************************/ |
693 | static int br_nf_forward_finish(struct sk_buff *skb) | |
694 | { | |
38330783 | 695 | struct nf_bridge_info *nf_bridge = nf_bridge_info_get(skb); |
1da177e4 | 696 | struct net_device *in; |
1da177e4 | 697 | |
739e4505 | 698 | if (!IS_ARP(skb) && !IS_VLAN_ARP(skb)) { |
0b67c43c FW |
699 | int frag_max_size; |
700 | ||
701 | if (skb->protocol == htons(ETH_P_IP)) { | |
702 | frag_max_size = IPCB(skb)->frag_max_size; | |
703 | BR_INPUT_SKB_CB(skb)->frag_max_size = frag_max_size; | |
704 | } | |
705 | ||
1da177e4 LT |
706 | in = nf_bridge->physindev; |
707 | if (nf_bridge->mask & BRNF_PKT_TYPE) { | |
708 | skb->pkt_type = PACKET_OTHERHOST; | |
709 | nf_bridge->mask ^= BRNF_PKT_TYPE; | |
710 | } | |
e94c6743 | 711 | nf_bridge_update_protocol(skb); |
1da177e4 LT |
712 | } else { |
713 | in = *((struct net_device **)(skb->cb)); | |
714 | } | |
fc38582d | 715 | nf_bridge_push_encap_header(skb); |
e179e632 | 716 | |
713aefa3 | 717 | NF_HOOK_THRESH(NFPROTO_BRIDGE, NF_BR_FORWARD, skb, in, |
789bc3e5 | 718 | skb->dev, br_forward_finish, 1); |
1da177e4 LT |
719 | return 0; |
720 | } | |
721 | ||
739e4505 | 722 | |
1da177e4 LT |
723 | /* This is the 'purely bridged' case. For IP, we pass the packet to |
724 | * netfilter with indev and outdev set to the bridge device, | |
725 | * but we are still able to filter on the 'real' indev/outdev | |
726 | * because of the physdev module. For ARP, indev and outdev are the | |
727 | * bridge ports. */ | |
795aa6ef PM |
728 | static unsigned int br_nf_forward_ip(const struct nf_hook_ops *ops, |
729 | struct sk_buff *skb, | |
789bc3e5 SH |
730 | const struct net_device *in, |
731 | const struct net_device *out, | |
732 | int (*okfn)(struct sk_buff *)) | |
1da177e4 | 733 | { |
1da177e4 | 734 | struct nf_bridge_info *nf_bridge; |
5dce971a | 735 | struct net_device *parent; |
76108cea | 736 | u_int8_t pf; |
1da177e4 LT |
737 | |
738 | if (!skb->nf_bridge) | |
739 | return NF_ACCEPT; | |
740 | ||
2dc2f207 PM |
741 | /* Need exclusive nf_bridge_info since we might have multiple |
742 | * different physoutdevs. */ | |
743 | if (!nf_bridge_unshare(skb)) | |
744 | return NF_DROP; | |
745 | ||
38330783 FW |
746 | nf_bridge = nf_bridge_info_get(skb); |
747 | if (!nf_bridge) | |
748 | return NF_DROP; | |
749 | ||
5dce971a SH |
750 | parent = bridge_parent(out); |
751 | if (!parent) | |
752 | return NF_DROP; | |
753 | ||
739e4505 | 754 | if (IS_IP(skb) || IS_VLAN_IP(skb) || IS_PPPOE_IP(skb)) |
aa740f46 | 755 | pf = NFPROTO_IPV4; |
739e4505 | 756 | else if (IS_IPV6(skb) || IS_VLAN_IPV6(skb) || IS_PPPOE_IPV6(skb)) |
aa740f46 | 757 | pf = NFPROTO_IPV6; |
a2bd40ad HX |
758 | else |
759 | return NF_ACCEPT; | |
1da177e4 | 760 | |
3db05fea | 761 | nf_bridge_pull_encap_header(skb); |
1da177e4 | 762 | |
1da177e4 LT |
763 | if (skb->pkt_type == PACKET_OTHERHOST) { |
764 | skb->pkt_type = PACKET_HOST; | |
765 | nf_bridge->mask |= BRNF_PKT_TYPE; | |
766 | } | |
767 | ||
0b67c43c FW |
768 | if (pf == NFPROTO_IPV4) { |
769 | int frag_max = BR_INPUT_SKB_CB(skb)->frag_max_size; | |
770 | ||
771 | if (br_parse_ip_options(skb)) | |
772 | return NF_DROP; | |
773 | ||
774 | IPCB(skb)->frag_max_size = frag_max; | |
775 | } | |
6b1e960f | 776 | |
1da177e4 | 777 | nf_bridge->physoutdev = skb->dev; |
aa740f46 | 778 | if (pf == NFPROTO_IPV4) |
e179e632 BDS |
779 | skb->protocol = htons(ETH_P_IP); |
780 | else | |
781 | skb->protocol = htons(ETH_P_IPV6); | |
1da177e4 | 782 | |
4981682c | 783 | NF_HOOK(pf, NF_INET_FORWARD, skb, brnf_get_logical_dev(skb, in), parent, |
5dce971a | 784 | br_nf_forward_finish); |
1da177e4 LT |
785 | |
786 | return NF_STOLEN; | |
787 | } | |
788 | ||
795aa6ef PM |
789 | static unsigned int br_nf_forward_arp(const struct nf_hook_ops *ops, |
790 | struct sk_buff *skb, | |
789bc3e5 SH |
791 | const struct net_device *in, |
792 | const struct net_device *out, | |
793 | int (*okfn)(struct sk_buff *)) | |
1da177e4 | 794 | { |
4df53d8b PM |
795 | struct net_bridge_port *p; |
796 | struct net_bridge *br; | |
1da177e4 LT |
797 | struct net_device **d = (struct net_device **)(skb->cb); |
798 | ||
e490c1de | 799 | p = br_port_get_rcu(out); |
4df53d8b PM |
800 | if (p == NULL) |
801 | return NF_ACCEPT; | |
802 | br = p->br; | |
803 | ||
804 | if (!brnf_call_arptables && !br->nf_call_arptables) | |
1da177e4 | 805 | return NF_ACCEPT; |
1da177e4 | 806 | |
739e4505 | 807 | if (!IS_ARP(skb)) { |
8b42ec39 | 808 | if (!IS_VLAN_ARP(skb)) |
1da177e4 | 809 | return NF_ACCEPT; |
3db05fea | 810 | nf_bridge_pull_encap_header(skb); |
1da177e4 LT |
811 | } |
812 | ||
d0a92be0 | 813 | if (arp_hdr(skb)->ar_pln != 4) { |
fc38582d | 814 | if (IS_VLAN_ARP(skb)) |
3db05fea | 815 | nf_bridge_push_encap_header(skb); |
1da177e4 LT |
816 | return NF_ACCEPT; |
817 | } | |
818 | *d = (struct net_device *)in; | |
fdc9314c | 819 | NF_HOOK(NFPROTO_ARP, NF_ARP_FORWARD, skb, (struct net_device *)in, |
1da177e4 LT |
820 | (struct net_device *)out, br_nf_forward_finish); |
821 | ||
822 | return NF_STOLEN; | |
823 | } | |
824 | ||
aff09ce3 | 825 | #if IS_ENABLED(CONFIG_NF_DEFRAG_IPV4) |
e70deecb | 826 | static int br_nf_push_frag_xmit(struct sk_buff *skb) |
8bd63cf1 | 827 | { |
e70deecb | 828 | struct brnf_frag_data *data; |
8bd63cf1 | 829 | int err; |
8bd63cf1 | 830 | |
e70deecb FW |
831 | data = this_cpu_ptr(&brnf_frag_data_storage); |
832 | err = skb_cow_head(skb, data->size); | |
8bd63cf1 | 833 | |
e70deecb | 834 | if (err) { |
8bd63cf1 FW |
835 | kfree_skb(skb); |
836 | return 0; | |
837 | } | |
838 | ||
e70deecb FW |
839 | skb_copy_to_linear_data_offset(skb, -data->size, data->mac, data->size); |
840 | __skb_push(skb, data->encap_size); | |
841 | ||
8bd63cf1 FW |
842 | return br_dev_queue_push_xmit(skb); |
843 | } | |
844 | ||
2e2f7aef PM |
845 | static int br_nf_dev_queue_xmit(struct sk_buff *skb) |
846 | { | |
462fb2af | 847 | int ret; |
93fdd47e | 848 | int frag_max_size; |
7a8d831d | 849 | unsigned int mtu_reserved; |
462fb2af | 850 | |
7a8d831d FW |
851 | if (skb_is_gso(skb) || skb->protocol != htons(ETH_P_IP)) |
852 | return br_dev_queue_push_xmit(skb); | |
853 | ||
854 | mtu_reserved = nf_bridge_mtu_reduction(skb); | |
93fdd47e HX |
855 | /* This is wrong! We should preserve the original fragment |
856 | * boundaries by preserving frag_list rather than refragmenting. | |
857 | */ | |
7a8d831d | 858 | if (skb->len + mtu_reserved > skb->dev->mtu) { |
e70deecb FW |
859 | struct brnf_frag_data *data; |
860 | ||
93fdd47e | 861 | frag_max_size = BR_INPUT_SKB_CB(skb)->frag_max_size; |
462fb2af BD |
862 | if (br_parse_ip_options(skb)) |
863 | /* Drop invalid packet */ | |
864 | return NF_DROP; | |
93fdd47e | 865 | IPCB(skb)->frag_max_size = frag_max_size; |
e70deecb FW |
866 | |
867 | nf_bridge_update_protocol(skb); | |
868 | ||
869 | data = this_cpu_ptr(&brnf_frag_data_storage); | |
870 | data->encap_size = nf_bridge_encap_header_len(skb); | |
871 | data->size = ETH_HLEN + data->encap_size; | |
872 | ||
873 | skb_copy_from_linear_data_offset(skb, -data->size, data->mac, | |
874 | data->size); | |
875 | ||
8bd63cf1 | 876 | ret = ip_fragment(skb, br_nf_push_frag_xmit); |
e70deecb | 877 | } else { |
462fb2af | 878 | ret = br_dev_queue_push_xmit(skb); |
e70deecb | 879 | } |
462fb2af BD |
880 | |
881 | return ret; | |
2e2f7aef | 882 | } |
c197facc | 883 | #else |
884 | static int br_nf_dev_queue_xmit(struct sk_buff *skb) | |
885 | { | |
886 | return br_dev_queue_push_xmit(skb); | |
887 | } | |
888 | #endif | |
1da177e4 LT |
889 | |
890 | /* PF_BRIDGE/POST_ROUTING ********************************************/ | |
795aa6ef PM |
891 | static unsigned int br_nf_post_routing(const struct nf_hook_ops *ops, |
892 | struct sk_buff *skb, | |
789bc3e5 SH |
893 | const struct net_device *in, |
894 | const struct net_device *out, | |
895 | int (*okfn)(struct sk_buff *)) | |
1da177e4 | 896 | { |
38330783 | 897 | struct nf_bridge_info *nf_bridge = nf_bridge_info_get(skb); |
1da177e4 | 898 | struct net_device *realoutdev = bridge_parent(skb->dev); |
76108cea | 899 | u_int8_t pf; |
1da177e4 | 900 | |
e4bb9bcb FW |
901 | /* if nf_bridge is set, but ->physoutdev is NULL, this packet came in |
902 | * on a bridge, but was delivered locally and is now being routed: | |
903 | * | |
904 | * POST_ROUTING was already invoked from the ip stack. | |
905 | */ | |
906 | if (!nf_bridge || !nf_bridge->physoutdev) | |
81d9ddae PM |
907 | return NF_ACCEPT; |
908 | ||
5dce971a SH |
909 | if (!realoutdev) |
910 | return NF_DROP; | |
911 | ||
739e4505 | 912 | if (IS_IP(skb) || IS_VLAN_IP(skb) || IS_PPPOE_IP(skb)) |
aa740f46 | 913 | pf = NFPROTO_IPV4; |
739e4505 | 914 | else if (IS_IPV6(skb) || IS_VLAN_IPV6(skb) || IS_PPPOE_IPV6(skb)) |
aa740f46 | 915 | pf = NFPROTO_IPV6; |
a2bd40ad HX |
916 | else |
917 | return NF_ACCEPT; | |
1da177e4 | 918 | |
1da177e4 LT |
919 | /* We assume any code from br_dev_queue_push_xmit onwards doesn't care |
920 | * about the value of skb->pkt_type. */ | |
921 | if (skb->pkt_type == PACKET_OTHERHOST) { | |
922 | skb->pkt_type = PACKET_HOST; | |
923 | nf_bridge->mask |= BRNF_PKT_TYPE; | |
924 | } | |
925 | ||
fc38582d | 926 | nf_bridge_pull_encap_header(skb); |
aa740f46 | 927 | if (pf == NFPROTO_IPV4) |
e179e632 BDS |
928 | skb->protocol = htons(ETH_P_IP); |
929 | else | |
930 | skb->protocol = htons(ETH_P_IPV6); | |
1da177e4 | 931 | |
6e23ae2a | 932 | NF_HOOK(pf, NF_INET_POST_ROUTING, skb, NULL, realoutdev, |
2e2f7aef | 933 | br_nf_dev_queue_xmit); |
1da177e4 LT |
934 | |
935 | return NF_STOLEN; | |
1da177e4 LT |
936 | } |
937 | ||
1da177e4 LT |
938 | /* IP/SABOTAGE *****************************************************/ |
939 | /* Don't hand locally destined packets to PF_INET(6)/PRE_ROUTING | |
940 | * for the second time. */ | |
795aa6ef PM |
941 | static unsigned int ip_sabotage_in(const struct nf_hook_ops *ops, |
942 | struct sk_buff *skb, | |
789bc3e5 SH |
943 | const struct net_device *in, |
944 | const struct net_device *out, | |
945 | int (*okfn)(struct sk_buff *)) | |
1da177e4 | 946 | { |
3db05fea HX |
947 | if (skb->nf_bridge && |
948 | !(skb->nf_bridge->mask & BRNF_NF_BRIDGE_PREROUTING)) { | |
1da177e4 LT |
949 | return NF_STOP; |
950 | } | |
951 | ||
952 | return NF_ACCEPT; | |
953 | } | |
954 | ||
e5de75bf PNA |
955 | /* This is called when br_netfilter has called into iptables/netfilter, |
956 | * and DNAT has taken place on a bridge-forwarded packet. | |
957 | * | |
958 | * neigh->output has created a new MAC header, with local br0 MAC | |
959 | * as saddr. | |
960 | * | |
961 | * This restores the original MAC saddr of the bridged packet | |
962 | * before invoking bridge forward logic to transmit the packet. | |
963 | */ | |
964 | static void br_nf_pre_routing_finish_bridge_slow(struct sk_buff *skb) | |
965 | { | |
38330783 | 966 | struct nf_bridge_info *nf_bridge = nf_bridge_info_get(skb); |
e5de75bf PNA |
967 | |
968 | skb_pull(skb, ETH_HLEN); | |
969 | nf_bridge->mask &= ~BRNF_BRIDGED_DNAT; | |
970 | ||
e70deecb FW |
971 | BUILD_BUG_ON(sizeof(nf_bridge->neigh_header) != (ETH_HLEN - ETH_ALEN)); |
972 | ||
973 | skb_copy_to_linear_data_offset(skb, -(ETH_HLEN - ETH_ALEN), | |
974 | nf_bridge->neigh_header, | |
975 | ETH_HLEN - ETH_ALEN); | |
e5de75bf PNA |
976 | skb->dev = nf_bridge->physindev; |
977 | br_handle_frame_finish(skb); | |
978 | } | |
979 | ||
1a4ba64d | 980 | static int br_nf_dev_xmit(struct sk_buff *skb) |
e5de75bf PNA |
981 | { |
982 | if (skb->nf_bridge && (skb->nf_bridge->mask & BRNF_BRIDGED_DNAT)) { | |
983 | br_nf_pre_routing_finish_bridge_slow(skb); | |
984 | return 1; | |
985 | } | |
986 | return 0; | |
987 | } | |
1a4ba64d PNA |
988 | |
989 | static const struct nf_br_ops br_ops = { | |
990 | .br_dev_xmit_hook = br_nf_dev_xmit, | |
991 | }; | |
e5de75bf | 992 | |
4b7fd5d9 PNA |
993 | void br_netfilter_enable(void) |
994 | { | |
995 | } | |
996 | EXPORT_SYMBOL_GPL(br_netfilter_enable); | |
997 | ||
ea2d9b41 BDS |
998 | /* For br_nf_post_routing, we need (prio = NF_BR_PRI_LAST), because |
999 | * br_dev_queue_push_xmit is called afterwards */ | |
1999414a | 1000 | static struct nf_hook_ops br_nf_ops[] __read_mostly = { |
1490fd89 CG |
1001 | { |
1002 | .hook = br_nf_pre_routing, | |
1003 | .owner = THIS_MODULE, | |
aa740f46 | 1004 | .pf = NFPROTO_BRIDGE, |
1490fd89 CG |
1005 | .hooknum = NF_BR_PRE_ROUTING, |
1006 | .priority = NF_BR_PRI_BRNF, | |
1007 | }, | |
1008 | { | |
1009 | .hook = br_nf_local_in, | |
1010 | .owner = THIS_MODULE, | |
aa740f46 | 1011 | .pf = NFPROTO_BRIDGE, |
1490fd89 CG |
1012 | .hooknum = NF_BR_LOCAL_IN, |
1013 | .priority = NF_BR_PRI_BRNF, | |
1014 | }, | |
1015 | { | |
1016 | .hook = br_nf_forward_ip, | |
1017 | .owner = THIS_MODULE, | |
aa740f46 | 1018 | .pf = NFPROTO_BRIDGE, |
1490fd89 CG |
1019 | .hooknum = NF_BR_FORWARD, |
1020 | .priority = NF_BR_PRI_BRNF - 1, | |
1021 | }, | |
1022 | { | |
1023 | .hook = br_nf_forward_arp, | |
1024 | .owner = THIS_MODULE, | |
aa740f46 | 1025 | .pf = NFPROTO_BRIDGE, |
1490fd89 CG |
1026 | .hooknum = NF_BR_FORWARD, |
1027 | .priority = NF_BR_PRI_BRNF, | |
1028 | }, | |
1490fd89 CG |
1029 | { |
1030 | .hook = br_nf_post_routing, | |
1031 | .owner = THIS_MODULE, | |
aa740f46 | 1032 | .pf = NFPROTO_BRIDGE, |
1490fd89 CG |
1033 | .hooknum = NF_BR_POST_ROUTING, |
1034 | .priority = NF_BR_PRI_LAST, | |
1035 | }, | |
1036 | { | |
1037 | .hook = ip_sabotage_in, | |
1038 | .owner = THIS_MODULE, | |
aa740f46 | 1039 | .pf = NFPROTO_IPV4, |
1490fd89 CG |
1040 | .hooknum = NF_INET_PRE_ROUTING, |
1041 | .priority = NF_IP_PRI_FIRST, | |
1042 | }, | |
1043 | { | |
1044 | .hook = ip_sabotage_in, | |
1045 | .owner = THIS_MODULE, | |
aa740f46 | 1046 | .pf = NFPROTO_IPV6, |
1490fd89 CG |
1047 | .hooknum = NF_INET_PRE_ROUTING, |
1048 | .priority = NF_IP6_PRI_FIRST, | |
1049 | }, | |
1da177e4 LT |
1050 | }; |
1051 | ||
1052 | #ifdef CONFIG_SYSCTL | |
1053 | static | |
fe2c6338 | 1054 | int brnf_sysctl_call_tables(struct ctl_table *ctl, int write, |
56b148eb | 1055 | void __user *buffer, size_t *lenp, loff_t *ppos) |
1da177e4 LT |
1056 | { |
1057 | int ret; | |
1058 | ||
8d65af78 | 1059 | ret = proc_dointvec(ctl, write, buffer, lenp, ppos); |
1da177e4 LT |
1060 | |
1061 | if (write && *(int *)(ctl->data)) | |
1062 | *(int *)(ctl->data) = 1; | |
1063 | return ret; | |
1064 | } | |
1065 | ||
fe2c6338 | 1066 | static struct ctl_table brnf_table[] = { |
1da177e4 | 1067 | { |
1da177e4 LT |
1068 | .procname = "bridge-nf-call-arptables", |
1069 | .data = &brnf_call_arptables, | |
1070 | .maxlen = sizeof(int), | |
1071 | .mode = 0644, | |
6d9f239a | 1072 | .proc_handler = brnf_sysctl_call_tables, |
1da177e4 LT |
1073 | }, |
1074 | { | |
1da177e4 LT |
1075 | .procname = "bridge-nf-call-iptables", |
1076 | .data = &brnf_call_iptables, | |
1077 | .maxlen = sizeof(int), | |
1078 | .mode = 0644, | |
6d9f239a | 1079 | .proc_handler = brnf_sysctl_call_tables, |
1da177e4 LT |
1080 | }, |
1081 | { | |
1da177e4 LT |
1082 | .procname = "bridge-nf-call-ip6tables", |
1083 | .data = &brnf_call_ip6tables, | |
1084 | .maxlen = sizeof(int), | |
1085 | .mode = 0644, | |
6d9f239a | 1086 | .proc_handler = brnf_sysctl_call_tables, |
1da177e4 LT |
1087 | }, |
1088 | { | |
1da177e4 LT |
1089 | .procname = "bridge-nf-filter-vlan-tagged", |
1090 | .data = &brnf_filter_vlan_tagged, | |
1091 | .maxlen = sizeof(int), | |
1092 | .mode = 0644, | |
6d9f239a | 1093 | .proc_handler = brnf_sysctl_call_tables, |
516299d2 MM |
1094 | }, |
1095 | { | |
516299d2 MM |
1096 | .procname = "bridge-nf-filter-pppoe-tagged", |
1097 | .data = &brnf_filter_pppoe_tagged, | |
1098 | .maxlen = sizeof(int), | |
1099 | .mode = 0644, | |
6d9f239a | 1100 | .proc_handler = brnf_sysctl_call_tables, |
1da177e4 | 1101 | }, |
4981682c PNA |
1102 | { |
1103 | .procname = "bridge-nf-pass-vlan-input-dev", | |
1104 | .data = &brnf_pass_vlan_indev, | |
1105 | .maxlen = sizeof(int), | |
1106 | .mode = 0644, | |
1107 | .proc_handler = brnf_sysctl_call_tables, | |
1108 | }, | |
f8572d8f | 1109 | { } |
1da177e4 | 1110 | }; |
1da177e4 LT |
1111 | #endif |
1112 | ||
34666d46 | 1113 | static int __init br_netfilter_init(void) |
1da177e4 | 1114 | { |
5eb87f45 | 1115 | int ret; |
1da177e4 | 1116 | |
34666d46 | 1117 | ret = nf_register_hooks(br_nf_ops, ARRAY_SIZE(br_nf_ops)); |
5eb87f45 | 1118 | if (ret < 0) |
1da177e4 | 1119 | return ret; |
fc66f95c | 1120 | |
1da177e4 | 1121 | #ifdef CONFIG_SYSCTL |
ec8f23ce | 1122 | brnf_sysctl_header = register_net_sysctl(&init_net, "net/bridge", brnf_table); |
1da177e4 | 1123 | if (brnf_sysctl_header == NULL) { |
789bc3e5 SH |
1124 | printk(KERN_WARNING |
1125 | "br_netfilter: can't register to sysctl.\n"); | |
96727239 GU |
1126 | nf_unregister_hooks(br_nf_ops, ARRAY_SIZE(br_nf_ops)); |
1127 | return -ENOMEM; | |
1da177e4 LT |
1128 | } |
1129 | #endif | |
1a4ba64d | 1130 | RCU_INIT_POINTER(nf_br_ops, &br_ops); |
1da177e4 | 1131 | printk(KERN_NOTICE "Bridge firewalling registered\n"); |
1da177e4 LT |
1132 | return 0; |
1133 | } | |
1134 | ||
34666d46 | 1135 | static void __exit br_netfilter_fini(void) |
1da177e4 | 1136 | { |
1a4ba64d | 1137 | RCU_INIT_POINTER(nf_br_ops, NULL); |
5eb87f45 | 1138 | nf_unregister_hooks(br_nf_ops, ARRAY_SIZE(br_nf_ops)); |
1da177e4 | 1139 | #ifdef CONFIG_SYSCTL |
5dd3df10 | 1140 | unregister_net_sysctl_table(brnf_sysctl_header); |
1da177e4 LT |
1141 | #endif |
1142 | } | |
34666d46 PNA |
1143 | |
1144 | module_init(br_netfilter_init); | |
1145 | module_exit(br_netfilter_fini); | |
1146 | ||
1147 | MODULE_LICENSE("GPL"); | |
1148 | MODULE_AUTHOR("Lennert Buytenhek <buytenh@gnu.org>"); | |
1149 | MODULE_AUTHOR("Bart De Schuymer <bdschuym@pandora.be>"); | |
1150 | MODULE_DESCRIPTION("Linux ethernet netfilter firewall bridge"); |