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 | { | |
3eaf4025 FW |
265 | switch (skb->nf_bridge->orig_proto) { |
266 | case BRNF_PROTO_8021Q: | |
4a9d2f20 | 267 | skb->protocol = htons(ETH_P_8021Q); |
3eaf4025 FW |
268 | break; |
269 | case BRNF_PROTO_PPPOE: | |
4a9d2f20 | 270 | skb->protocol = htons(ETH_P_PPP_SES); |
3eaf4025 FW |
271 | break; |
272 | case BRNF_PROTO_UNCHANGED: | |
273 | break; | |
274 | } | |
4a9d2f20 FW |
275 | } |
276 | ||
1da177e4 LT |
277 | /* PF_BRIDGE/PRE_ROUTING *********************************************/ |
278 | /* Undo the changes made for ip6tables PREROUTING and continue the | |
279 | * bridge PRE_ROUTING hook. */ | |
280 | static int br_nf_pre_routing_finish_ipv6(struct sk_buff *skb) | |
281 | { | |
38330783 | 282 | struct nf_bridge_info *nf_bridge = nf_bridge_info_get(skb); |
511c3f92 | 283 | struct rtable *rt; |
1da177e4 | 284 | |
1da177e4 LT |
285 | if (nf_bridge->mask & BRNF_PKT_TYPE) { |
286 | skb->pkt_type = PACKET_OTHERHOST; | |
287 | nf_bridge->mask ^= BRNF_PKT_TYPE; | |
288 | } | |
289 | nf_bridge->mask ^= BRNF_NF_BRIDGE_PREROUTING; | |
290 | ||
511c3f92 ED |
291 | rt = bridge_parent_rtable(nf_bridge->physindev); |
292 | if (!rt) { | |
4adf0af6 SW |
293 | kfree_skb(skb); |
294 | return 0; | |
295 | } | |
f9181f4f | 296 | skb_dst_set_noref(skb, &rt->dst); |
1da177e4 LT |
297 | |
298 | skb->dev = nf_bridge->physindev; | |
e179e632 | 299 | nf_bridge_update_protocol(skb); |
fc38582d | 300 | nf_bridge_push_encap_header(skb); |
713aefa3 | 301 | NF_HOOK_THRESH(NFPROTO_BRIDGE, NF_BR_PRE_ROUTING, skb, skb->dev, NULL, |
1da177e4 LT |
302 | br_handle_frame_finish, 1); |
303 | ||
304 | return 0; | |
305 | } | |
306 | ||
e179e632 BDS |
307 | /* Obtain the correct destination MAC address, while preserving the original |
308 | * source MAC address. If we already know this address, we just copy it. If we | |
309 | * don't, we use the neighbour framework to find out. In both cases, we make | |
310 | * sure that br_handle_frame_finish() is called afterwards. | |
311 | */ | |
312 | static int br_nf_pre_routing_finish_bridge(struct sk_buff *skb) | |
313 | { | |
f6b72b62 | 314 | struct neighbour *neigh; |
e179e632 BDS |
315 | struct dst_entry *dst; |
316 | ||
317 | skb->dev = bridge_parent(skb->dev); | |
318 | if (!skb->dev) | |
319 | goto free_skb; | |
320 | dst = skb_dst(skb); | |
f9d75166 DM |
321 | neigh = dst_neigh_lookup_skb(dst, skb); |
322 | if (neigh) { | |
38330783 | 323 | struct nf_bridge_info *nf_bridge = nf_bridge_info_get(skb); |
f9d75166 DM |
324 | int ret; |
325 | ||
326 | if (neigh->hh.hh_len) { | |
327 | neigh_hh_bridge(&neigh->hh, skb); | |
328 | skb->dev = nf_bridge->physindev; | |
329 | ret = br_handle_frame_finish(skb); | |
330 | } else { | |
331 | /* the neighbour function below overwrites the complete | |
332 | * MAC header, so we save the Ethernet source address and | |
333 | * protocol number. | |
334 | */ | |
335 | skb_copy_from_linear_data_offset(skb, | |
336 | -(ETH_HLEN-ETH_ALEN), | |
e70deecb | 337 | nf_bridge->neigh_header, |
f9d75166 DM |
338 | ETH_HLEN-ETH_ALEN); |
339 | /* tell br_dev_xmit to continue with forwarding */ | |
340 | nf_bridge->mask |= BRNF_BRIDGED_DNAT; | |
93fdd47e | 341 | /* FIXME Need to refragment */ |
f9d75166 DM |
342 | ret = neigh->output(neigh, skb); |
343 | } | |
344 | neigh_release(neigh); | |
345 | return ret; | |
e179e632 BDS |
346 | } |
347 | free_skb: | |
348 | kfree_skb(skb); | |
349 | return 0; | |
350 | } | |
351 | ||
c055d5b0 FW |
352 | static bool dnat_took_place(const struct sk_buff *skb) |
353 | { | |
354 | #if IS_ENABLED(CONFIG_NF_CONNTRACK) | |
355 | enum ip_conntrack_info ctinfo; | |
356 | struct nf_conn *ct; | |
357 | ||
358 | ct = nf_ct_get(skb, &ctinfo); | |
359 | if (!ct || nf_ct_is_untracked(ct)) | |
360 | return false; | |
361 | ||
362 | return test_bit(IPS_DST_NAT_BIT, &ct->status); | |
363 | #else | |
364 | return false; | |
365 | #endif | |
366 | } | |
367 | ||
1da177e4 | 368 | /* This requires some explaining. If DNAT has taken place, |
ea2d9b41 | 369 | * we will need to fix up the destination Ethernet address. |
1da177e4 LT |
370 | * |
371 | * There are two cases to consider: | |
372 | * 1. The packet was DNAT'ed to a device in the same bridge | |
373 | * port group as it was received on. We can still bridge | |
374 | * the packet. | |
375 | * 2. The packet was DNAT'ed to a different device, either | |
376 | * a non-bridged device or another bridge port group. | |
377 | * The packet will need to be routed. | |
378 | * | |
379 | * The correct way of distinguishing between these two cases is to | |
380 | * call ip_route_input() and to look at skb->dst->dev, which is | |
381 | * changed to the destination device if ip_route_input() succeeds. | |
382 | * | |
ea2d9b41 | 383 | * Let's first consider the case that ip_route_input() succeeds: |
1da177e4 | 384 | * |
ea2d9b41 BDS |
385 | * If the output device equals the logical bridge device the packet |
386 | * came in on, we can consider this bridging. The corresponding MAC | |
387 | * address will be obtained in br_nf_pre_routing_finish_bridge. | |
1da177e4 LT |
388 | * Otherwise, the packet is considered to be routed and we just |
389 | * change the destination MAC address so that the packet will | |
f216f082 BDS |
390 | * later be passed up to the IP stack to be routed. For a redirected |
391 | * packet, ip_route_input() will give back the localhost as output device, | |
392 | * which differs from the bridge device. | |
1da177e4 | 393 | * |
ea2d9b41 | 394 | * Let's now consider the case that ip_route_input() fails: |
1da177e4 | 395 | * |
f216f082 BDS |
396 | * This can be because the destination address is martian, in which case |
397 | * the packet will be dropped. | |
ea2d9b41 BDS |
398 | * If IP forwarding is disabled, ip_route_input() will fail, while |
399 | * ip_route_output_key() can return success. The source | |
400 | * address for ip_route_output_key() is set to zero, so ip_route_output_key() | |
1da177e4 | 401 | * thinks we're handling a locally generated packet and won't care |
ea2d9b41 BDS |
402 | * if IP forwarding is enabled. If the output device equals the logical bridge |
403 | * device, we proceed as if ip_route_input() succeeded. If it differs from the | |
404 | * logical bridge port or if ip_route_output_key() fails we drop the packet. | |
405 | */ | |
1da177e4 LT |
406 | static int br_nf_pre_routing_finish(struct sk_buff *skb) |
407 | { | |
408 | struct net_device *dev = skb->dev; | |
eddc9ec5 | 409 | struct iphdr *iph = ip_hdr(skb); |
38330783 | 410 | struct nf_bridge_info *nf_bridge = nf_bridge_info_get(skb); |
511c3f92 | 411 | struct rtable *rt; |
f216f082 | 412 | int err; |
93fdd47e HX |
413 | int frag_max_size; |
414 | ||
415 | frag_max_size = IPCB(skb)->frag_max_size; | |
416 | BR_INPUT_SKB_CB(skb)->frag_max_size = frag_max_size; | |
1da177e4 | 417 | |
1da177e4 LT |
418 | if (nf_bridge->mask & BRNF_PKT_TYPE) { |
419 | skb->pkt_type = PACKET_OTHERHOST; | |
420 | nf_bridge->mask ^= BRNF_PKT_TYPE; | |
421 | } | |
422 | nf_bridge->mask ^= BRNF_NF_BRIDGE_PREROUTING; | |
1da177e4 | 423 | if (dnat_took_place(skb)) { |
f216f082 | 424 | if ((err = ip_route_input(skb, iph->daddr, iph->saddr, iph->tos, dev))) { |
f3abc9b9 | 425 | struct in_device *in_dev = __in_dev_get_rcu(dev); |
f216f082 BDS |
426 | |
427 | /* If err equals -EHOSTUNREACH the error is due to a | |
428 | * martian destination or due to the fact that | |
429 | * forwarding is disabled. For most martian packets, | |
430 | * ip_route_output_key() will fail. It won't fail for 2 types of | |
431 | * martian destinations: loopback destinations and destination | |
432 | * 0.0.0.0. In both cases the packet will be dropped because the | |
433 | * destination is the loopback device and not the bridge. */ | |
434 | if (err != -EHOSTUNREACH || !in_dev || IN_DEV_FORWARD(in_dev)) | |
435 | goto free_skb; | |
1da177e4 | 436 | |
78fbfd8a DM |
437 | rt = ip_route_output(dev_net(dev), iph->daddr, 0, |
438 | RT_TOS(iph->tos), 0); | |
b23dd4fe | 439 | if (!IS_ERR(rt)) { |
1c011bed | 440 | /* - Bridged-and-DNAT'ed traffic doesn't |
f216f082 | 441 | * require ip_forwarding. */ |
b23dd4fe DM |
442 | if (rt->dst.dev == dev) { |
443 | skb_dst_set(skb, &rt->dst); | |
1da177e4 LT |
444 | goto bridged_dnat; |
445 | } | |
b23dd4fe | 446 | ip_rt_put(rt); |
1da177e4 | 447 | } |
f216f082 | 448 | free_skb: |
1da177e4 LT |
449 | kfree_skb(skb); |
450 | return 0; | |
451 | } else { | |
adf30907 | 452 | if (skb_dst(skb)->dev == dev) { |
1da177e4 | 453 | bridged_dnat: |
1da177e4 | 454 | skb->dev = nf_bridge->physindev; |
e179e632 | 455 | nf_bridge_update_protocol(skb); |
fc38582d | 456 | nf_bridge_push_encap_header(skb); |
713aefa3 JE |
457 | NF_HOOK_THRESH(NFPROTO_BRIDGE, |
458 | NF_BR_PRE_ROUTING, | |
1da177e4 LT |
459 | skb, skb->dev, NULL, |
460 | br_nf_pre_routing_finish_bridge, | |
461 | 1); | |
462 | return 0; | |
463 | } | |
04091142 | 464 | ether_addr_copy(eth_hdr(skb)->h_dest, dev->dev_addr); |
1da177e4 LT |
465 | skb->pkt_type = PACKET_HOST; |
466 | } | |
467 | } else { | |
511c3f92 ED |
468 | rt = bridge_parent_rtable(nf_bridge->physindev); |
469 | if (!rt) { | |
4adf0af6 SW |
470 | kfree_skb(skb); |
471 | return 0; | |
472 | } | |
f9181f4f | 473 | skb_dst_set_noref(skb, &rt->dst); |
1da177e4 LT |
474 | } |
475 | ||
476 | skb->dev = nf_bridge->physindev; | |
e179e632 | 477 | nf_bridge_update_protocol(skb); |
fc38582d | 478 | nf_bridge_push_encap_header(skb); |
713aefa3 | 479 | NF_HOOK_THRESH(NFPROTO_BRIDGE, NF_BR_PRE_ROUTING, skb, skb->dev, NULL, |
1da177e4 LT |
480 | br_handle_frame_finish, 1); |
481 | ||
482 | return 0; | |
483 | } | |
484 | ||
4981682c PNA |
485 | static struct net_device *brnf_get_logical_dev(struct sk_buff *skb, const struct net_device *dev) |
486 | { | |
487 | struct net_device *vlan, *br; | |
488 | ||
489 | br = bridge_parent(dev); | |
df8a39de | 490 | if (brnf_pass_vlan_indev == 0 || !skb_vlan_tag_present(skb)) |
4981682c PNA |
491 | return br; |
492 | ||
f06c7f9f | 493 | vlan = __vlan_find_dev_deep_rcu(br, skb->vlan_proto, |
df8a39de | 494 | skb_vlan_tag_get(skb) & VLAN_VID_MASK); |
4981682c PNA |
495 | |
496 | return vlan ? vlan : br; | |
497 | } | |
498 | ||
1da177e4 | 499 | /* Some common code for IPv4/IPv6 */ |
5dce971a | 500 | static struct net_device *setup_pre_routing(struct sk_buff *skb) |
1da177e4 | 501 | { |
38330783 | 502 | struct nf_bridge_info *nf_bridge = nf_bridge_info_get(skb); |
1da177e4 LT |
503 | |
504 | if (skb->pkt_type == PACKET_OTHERHOST) { | |
505 | skb->pkt_type = PACKET_HOST; | |
506 | nf_bridge->mask |= BRNF_PKT_TYPE; | |
507 | } | |
508 | ||
509 | nf_bridge->mask |= BRNF_NF_BRIDGE_PREROUTING; | |
510 | nf_bridge->physindev = skb->dev; | |
4981682c | 511 | skb->dev = brnf_get_logical_dev(skb, skb->dev); |
3eaf4025 | 512 | |
e179e632 | 513 | if (skb->protocol == htons(ETH_P_8021Q)) |
3eaf4025 | 514 | nf_bridge->orig_proto = BRNF_PROTO_8021Q; |
e179e632 | 515 | else if (skb->protocol == htons(ETH_P_PPP_SES)) |
3eaf4025 | 516 | nf_bridge->orig_proto = BRNF_PROTO_PPPOE; |
5dce971a | 517 | |
6b8dbcf2 FW |
518 | /* Must drop socket now because of tproxy. */ |
519 | skb_orphan(skb); | |
5dce971a | 520 | return skb->dev; |
1da177e4 LT |
521 | } |
522 | ||
523 | /* We only check the length. A bridge shouldn't do any hop-by-hop stuff anyway */ | |
524 | static int check_hbh_len(struct sk_buff *skb) | |
525 | { | |
0660e03f | 526 | unsigned char *raw = (u8 *)(ipv6_hdr(skb) + 1); |
1da177e4 | 527 | u32 pkt_len; |
d56f90a7 ACM |
528 | const unsigned char *nh = skb_network_header(skb); |
529 | int off = raw - nh; | |
789bc3e5 | 530 | int len = (raw[1] + 1) << 3; |
1da177e4 LT |
531 | |
532 | if ((raw + len) - skb->data > skb_headlen(skb)) | |
533 | goto bad; | |
534 | ||
535 | off += 2; | |
536 | len -= 2; | |
537 | ||
538 | while (len > 0) { | |
d56f90a7 | 539 | int optlen = nh[off + 1] + 2; |
1da177e4 | 540 | |
d56f90a7 | 541 | switch (nh[off]) { |
1de5a71c | 542 | case IPV6_TLV_PAD1: |
1da177e4 LT |
543 | optlen = 1; |
544 | break; | |
545 | ||
546 | case IPV6_TLV_PADN: | |
547 | break; | |
548 | ||
549 | case IPV6_TLV_JUMBO: | |
d56f90a7 | 550 | if (nh[off + 1] != 4 || (off & 3) != 2) |
1da177e4 | 551 | goto bad; |
d56f90a7 | 552 | pkt_len = ntohl(*(__be32 *) (nh + off + 2)); |
b0366486 | 553 | if (pkt_len <= IPV6_MAXPLEN || |
0660e03f | 554 | ipv6_hdr(skb)->payload_len) |
b0366486 | 555 | goto bad; |
1da177e4 LT |
556 | if (pkt_len > skb->len - sizeof(struct ipv6hdr)) |
557 | goto bad; | |
b0366486 | 558 | if (pskb_trim_rcsum(skb, |
789bc3e5 | 559 | pkt_len + sizeof(struct ipv6hdr))) |
b0366486 | 560 | goto bad; |
d56f90a7 | 561 | nh = skb_network_header(skb); |
1da177e4 LT |
562 | break; |
563 | default: | |
564 | if (optlen > len) | |
565 | goto bad; | |
566 | break; | |
567 | } | |
568 | off += optlen; | |
569 | len -= optlen; | |
570 | } | |
571 | if (len == 0) | |
572 | return 0; | |
573 | bad: | |
574 | return -1; | |
575 | ||
576 | } | |
577 | ||
578 | /* Replicate the checks that IPv6 does on packet reception and pass the packet | |
579 | * to ip6tables, which doesn't support NAT, so things are fairly simple. */ | |
795aa6ef | 580 | static unsigned int br_nf_pre_routing_ipv6(const struct nf_hook_ops *ops, |
789bc3e5 SH |
581 | struct sk_buff *skb, |
582 | const struct net_device *in, | |
583 | const struct net_device *out, | |
584 | int (*okfn)(struct sk_buff *)) | |
1da177e4 | 585 | { |
b71d1d42 | 586 | const struct ipv6hdr *hdr; |
1da177e4 | 587 | u32 pkt_len; |
1da177e4 LT |
588 | |
589 | if (skb->len < sizeof(struct ipv6hdr)) | |
deef4b52 | 590 | return NF_DROP; |
1da177e4 LT |
591 | |
592 | if (!pskb_may_pull(skb, sizeof(struct ipv6hdr))) | |
deef4b52 | 593 | return NF_DROP; |
1da177e4 | 594 | |
0660e03f | 595 | hdr = ipv6_hdr(skb); |
1da177e4 LT |
596 | |
597 | if (hdr->version != 6) | |
deef4b52 | 598 | return NF_DROP; |
1da177e4 LT |
599 | |
600 | pkt_len = ntohs(hdr->payload_len); | |
601 | ||
602 | if (pkt_len || hdr->nexthdr != NEXTHDR_HOP) { | |
603 | if (pkt_len + sizeof(struct ipv6hdr) > skb->len) | |
deef4b52 | 604 | return NF_DROP; |
b38dfee3 | 605 | if (pskb_trim_rcsum(skb, pkt_len + sizeof(struct ipv6hdr))) |
deef4b52 | 606 | return NF_DROP; |
1da177e4 LT |
607 | } |
608 | if (hdr->nexthdr == NEXTHDR_HOP && check_hbh_len(skb)) | |
deef4b52 | 609 | return NF_DROP; |
1da177e4 | 610 | |
789bc3e5 | 611 | nf_bridge_put(skb->nf_bridge); |
fdeabdef | 612 | if (!nf_bridge_alloc(skb)) |
1da177e4 | 613 | return NF_DROP; |
5dce971a SH |
614 | if (!setup_pre_routing(skb)) |
615 | return NF_DROP; | |
1da177e4 | 616 | |
e179e632 | 617 | skb->protocol = htons(ETH_P_IPV6); |
713aefa3 | 618 | NF_HOOK(NFPROTO_IPV6, NF_INET_PRE_ROUTING, skb, skb->dev, NULL, |
1da177e4 LT |
619 | br_nf_pre_routing_finish_ipv6); |
620 | ||
621 | return NF_STOLEN; | |
1da177e4 LT |
622 | } |
623 | ||
624 | /* Direct IPv6 traffic to br_nf_pre_routing_ipv6. | |
625 | * Replicate the checks that IPv4 does on packet reception. | |
626 | * Set skb->dev to the bridge device (i.e. parent of the | |
627 | * receiving device) to make netfilter happy, the REDIRECT | |
628 | * target in particular. Save the original destination IP | |
629 | * address to be able to detect DNAT afterwards. */ | |
795aa6ef PM |
630 | static unsigned int br_nf_pre_routing(const struct nf_hook_ops *ops, |
631 | struct sk_buff *skb, | |
ee02b3a6 SH |
632 | const struct net_device *in, |
633 | const struct net_device *out, | |
634 | int (*okfn)(struct sk_buff *)) | |
1da177e4 | 635 | { |
4df53d8b PM |
636 | struct net_bridge_port *p; |
637 | struct net_bridge *br; | |
e7c243c9 EP |
638 | __u32 len = nf_bridge_encap_header_len(skb); |
639 | ||
e7c243c9 | 640 | if (unlikely(!pskb_may_pull(skb, len))) |
deef4b52 | 641 | return NF_DROP; |
1da177e4 | 642 | |
e490c1de | 643 | p = br_port_get_rcu(in); |
4df53d8b | 644 | if (p == NULL) |
deef4b52 | 645 | return NF_DROP; |
4df53d8b PM |
646 | br = p->br; |
647 | ||
739e4505 | 648 | if (IS_IPV6(skb) || IS_VLAN_IPV6(skb) || IS_PPPOE_IPV6(skb)) { |
4df53d8b | 649 | if (!brnf_call_ip6tables && !br->nf_call_ip6tables) |
1da177e4 | 650 | return NF_ACCEPT; |
4df53d8b | 651 | |
fc38582d | 652 | nf_bridge_pull_encap_header_rcsum(skb); |
795aa6ef | 653 | return br_nf_pre_routing_ipv6(ops, skb, in, out, okfn); |
1da177e4 | 654 | } |
4df53d8b PM |
655 | |
656 | if (!brnf_call_iptables && !br->nf_call_iptables) | |
1da177e4 | 657 | return NF_ACCEPT; |
1da177e4 | 658 | |
739e4505 | 659 | if (!IS_IP(skb) && !IS_VLAN_IP(skb) && !IS_PPPOE_IP(skb)) |
1da177e4 LT |
660 | return NF_ACCEPT; |
661 | ||
fc38582d | 662 | nf_bridge_pull_encap_header_rcsum(skb); |
1da177e4 | 663 | |
462fb2af | 664 | if (br_parse_ip_options(skb)) |
deef4b52 | 665 | return NF_DROP; |
17762060 | 666 | |
789bc3e5 | 667 | nf_bridge_put(skb->nf_bridge); |
fdeabdef | 668 | if (!nf_bridge_alloc(skb)) |
1da177e4 | 669 | return NF_DROP; |
5dce971a SH |
670 | if (!setup_pre_routing(skb)) |
671 | return NF_DROP; | |
c055d5b0 | 672 | |
e179e632 | 673 | skb->protocol = htons(ETH_P_IP); |
1da177e4 | 674 | |
713aefa3 | 675 | NF_HOOK(NFPROTO_IPV4, NF_INET_PRE_ROUTING, skb, skb->dev, NULL, |
1da177e4 LT |
676 | br_nf_pre_routing_finish); |
677 | ||
678 | return NF_STOLEN; | |
1da177e4 LT |
679 | } |
680 | ||
681 | ||
682 | /* PF_BRIDGE/LOCAL_IN ************************************************/ | |
683 | /* The packet is locally destined, which requires a real | |
684 | * dst_entry, so detach the fake one. On the way up, the | |
685 | * packet would pass through PRE_ROUTING again (which already | |
686 | * took place when the packet entered the bridge), but we | |
687 | * register an IPv4 PRE_ROUTING 'sabotage' hook that will | |
688 | * prevent this from happening. */ | |
795aa6ef PM |
689 | static unsigned int br_nf_local_in(const struct nf_hook_ops *ops, |
690 | struct sk_buff *skb, | |
789bc3e5 SH |
691 | const struct net_device *in, |
692 | const struct net_device *out, | |
693 | int (*okfn)(struct sk_buff *)) | |
1da177e4 | 694 | { |
a881e963 | 695 | br_drop_fake_rtable(skb); |
1da177e4 LT |
696 | return NF_ACCEPT; |
697 | } | |
698 | ||
1da177e4 LT |
699 | /* PF_BRIDGE/FORWARD *************************************************/ |
700 | static int br_nf_forward_finish(struct sk_buff *skb) | |
701 | { | |
38330783 | 702 | struct nf_bridge_info *nf_bridge = nf_bridge_info_get(skb); |
1da177e4 | 703 | struct net_device *in; |
1da177e4 | 704 | |
739e4505 | 705 | if (!IS_ARP(skb) && !IS_VLAN_ARP(skb)) { |
0b67c43c FW |
706 | int frag_max_size; |
707 | ||
708 | if (skb->protocol == htons(ETH_P_IP)) { | |
709 | frag_max_size = IPCB(skb)->frag_max_size; | |
710 | BR_INPUT_SKB_CB(skb)->frag_max_size = frag_max_size; | |
711 | } | |
712 | ||
1da177e4 LT |
713 | in = nf_bridge->physindev; |
714 | if (nf_bridge->mask & BRNF_PKT_TYPE) { | |
715 | skb->pkt_type = PACKET_OTHERHOST; | |
716 | nf_bridge->mask ^= BRNF_PKT_TYPE; | |
717 | } | |
e94c6743 | 718 | nf_bridge_update_protocol(skb); |
1da177e4 LT |
719 | } else { |
720 | in = *((struct net_device **)(skb->cb)); | |
721 | } | |
fc38582d | 722 | nf_bridge_push_encap_header(skb); |
e179e632 | 723 | |
713aefa3 | 724 | NF_HOOK_THRESH(NFPROTO_BRIDGE, NF_BR_FORWARD, skb, in, |
789bc3e5 | 725 | skb->dev, br_forward_finish, 1); |
1da177e4 LT |
726 | return 0; |
727 | } | |
728 | ||
739e4505 | 729 | |
1da177e4 LT |
730 | /* This is the 'purely bridged' case. For IP, we pass the packet to |
731 | * netfilter with indev and outdev set to the bridge device, | |
732 | * but we are still able to filter on the 'real' indev/outdev | |
733 | * because of the physdev module. For ARP, indev and outdev are the | |
734 | * bridge ports. */ | |
795aa6ef PM |
735 | static unsigned int br_nf_forward_ip(const struct nf_hook_ops *ops, |
736 | struct sk_buff *skb, | |
789bc3e5 SH |
737 | const struct net_device *in, |
738 | const struct net_device *out, | |
739 | int (*okfn)(struct sk_buff *)) | |
1da177e4 | 740 | { |
1da177e4 | 741 | struct nf_bridge_info *nf_bridge; |
5dce971a | 742 | struct net_device *parent; |
76108cea | 743 | u_int8_t pf; |
1da177e4 LT |
744 | |
745 | if (!skb->nf_bridge) | |
746 | return NF_ACCEPT; | |
747 | ||
2dc2f207 PM |
748 | /* Need exclusive nf_bridge_info since we might have multiple |
749 | * different physoutdevs. */ | |
750 | if (!nf_bridge_unshare(skb)) | |
751 | return NF_DROP; | |
752 | ||
38330783 FW |
753 | nf_bridge = nf_bridge_info_get(skb); |
754 | if (!nf_bridge) | |
755 | return NF_DROP; | |
756 | ||
5dce971a SH |
757 | parent = bridge_parent(out); |
758 | if (!parent) | |
759 | return NF_DROP; | |
760 | ||
739e4505 | 761 | if (IS_IP(skb) || IS_VLAN_IP(skb) || IS_PPPOE_IP(skb)) |
aa740f46 | 762 | pf = NFPROTO_IPV4; |
739e4505 | 763 | else if (IS_IPV6(skb) || IS_VLAN_IPV6(skb) || IS_PPPOE_IPV6(skb)) |
aa740f46 | 764 | pf = NFPROTO_IPV6; |
a2bd40ad HX |
765 | else |
766 | return NF_ACCEPT; | |
1da177e4 | 767 | |
3db05fea | 768 | nf_bridge_pull_encap_header(skb); |
1da177e4 | 769 | |
1da177e4 LT |
770 | if (skb->pkt_type == PACKET_OTHERHOST) { |
771 | skb->pkt_type = PACKET_HOST; | |
772 | nf_bridge->mask |= BRNF_PKT_TYPE; | |
773 | } | |
774 | ||
0b67c43c FW |
775 | if (pf == NFPROTO_IPV4) { |
776 | int frag_max = BR_INPUT_SKB_CB(skb)->frag_max_size; | |
777 | ||
778 | if (br_parse_ip_options(skb)) | |
779 | return NF_DROP; | |
780 | ||
781 | IPCB(skb)->frag_max_size = frag_max; | |
782 | } | |
6b1e960f | 783 | |
1da177e4 | 784 | nf_bridge->physoutdev = skb->dev; |
aa740f46 | 785 | if (pf == NFPROTO_IPV4) |
e179e632 BDS |
786 | skb->protocol = htons(ETH_P_IP); |
787 | else | |
788 | skb->protocol = htons(ETH_P_IPV6); | |
1da177e4 | 789 | |
4981682c | 790 | NF_HOOK(pf, NF_INET_FORWARD, skb, brnf_get_logical_dev(skb, in), parent, |
5dce971a | 791 | br_nf_forward_finish); |
1da177e4 LT |
792 | |
793 | return NF_STOLEN; | |
794 | } | |
795 | ||
795aa6ef PM |
796 | static unsigned int br_nf_forward_arp(const struct nf_hook_ops *ops, |
797 | struct sk_buff *skb, | |
789bc3e5 SH |
798 | const struct net_device *in, |
799 | const struct net_device *out, | |
800 | int (*okfn)(struct sk_buff *)) | |
1da177e4 | 801 | { |
4df53d8b PM |
802 | struct net_bridge_port *p; |
803 | struct net_bridge *br; | |
1da177e4 LT |
804 | struct net_device **d = (struct net_device **)(skb->cb); |
805 | ||
e490c1de | 806 | p = br_port_get_rcu(out); |
4df53d8b PM |
807 | if (p == NULL) |
808 | return NF_ACCEPT; | |
809 | br = p->br; | |
810 | ||
811 | if (!brnf_call_arptables && !br->nf_call_arptables) | |
1da177e4 | 812 | return NF_ACCEPT; |
1da177e4 | 813 | |
739e4505 | 814 | if (!IS_ARP(skb)) { |
8b42ec39 | 815 | if (!IS_VLAN_ARP(skb)) |
1da177e4 | 816 | return NF_ACCEPT; |
3db05fea | 817 | nf_bridge_pull_encap_header(skb); |
1da177e4 LT |
818 | } |
819 | ||
d0a92be0 | 820 | if (arp_hdr(skb)->ar_pln != 4) { |
fc38582d | 821 | if (IS_VLAN_ARP(skb)) |
3db05fea | 822 | nf_bridge_push_encap_header(skb); |
1da177e4 LT |
823 | return NF_ACCEPT; |
824 | } | |
825 | *d = (struct net_device *)in; | |
fdc9314c | 826 | NF_HOOK(NFPROTO_ARP, NF_ARP_FORWARD, skb, (struct net_device *)in, |
1da177e4 LT |
827 | (struct net_device *)out, br_nf_forward_finish); |
828 | ||
829 | return NF_STOLEN; | |
830 | } | |
831 | ||
aff09ce3 | 832 | #if IS_ENABLED(CONFIG_NF_DEFRAG_IPV4) |
e70deecb | 833 | static int br_nf_push_frag_xmit(struct sk_buff *skb) |
8bd63cf1 | 834 | { |
e70deecb | 835 | struct brnf_frag_data *data; |
8bd63cf1 | 836 | int err; |
8bd63cf1 | 837 | |
e70deecb FW |
838 | data = this_cpu_ptr(&brnf_frag_data_storage); |
839 | err = skb_cow_head(skb, data->size); | |
8bd63cf1 | 840 | |
e70deecb | 841 | if (err) { |
8bd63cf1 FW |
842 | kfree_skb(skb); |
843 | return 0; | |
844 | } | |
845 | ||
e70deecb FW |
846 | skb_copy_to_linear_data_offset(skb, -data->size, data->mac, data->size); |
847 | __skb_push(skb, data->encap_size); | |
848 | ||
8bd63cf1 FW |
849 | return br_dev_queue_push_xmit(skb); |
850 | } | |
851 | ||
2e2f7aef PM |
852 | static int br_nf_dev_queue_xmit(struct sk_buff *skb) |
853 | { | |
462fb2af | 854 | int ret; |
93fdd47e | 855 | int frag_max_size; |
7a8d831d | 856 | unsigned int mtu_reserved; |
462fb2af | 857 | |
7a8d831d FW |
858 | if (skb_is_gso(skb) || skb->protocol != htons(ETH_P_IP)) |
859 | return br_dev_queue_push_xmit(skb); | |
860 | ||
861 | mtu_reserved = nf_bridge_mtu_reduction(skb); | |
93fdd47e HX |
862 | /* This is wrong! We should preserve the original fragment |
863 | * boundaries by preserving frag_list rather than refragmenting. | |
864 | */ | |
7a8d831d | 865 | if (skb->len + mtu_reserved > skb->dev->mtu) { |
e70deecb FW |
866 | struct brnf_frag_data *data; |
867 | ||
93fdd47e | 868 | frag_max_size = BR_INPUT_SKB_CB(skb)->frag_max_size; |
462fb2af BD |
869 | if (br_parse_ip_options(skb)) |
870 | /* Drop invalid packet */ | |
871 | return NF_DROP; | |
93fdd47e | 872 | IPCB(skb)->frag_max_size = frag_max_size; |
e70deecb FW |
873 | |
874 | nf_bridge_update_protocol(skb); | |
875 | ||
876 | data = this_cpu_ptr(&brnf_frag_data_storage); | |
877 | data->encap_size = nf_bridge_encap_header_len(skb); | |
878 | data->size = ETH_HLEN + data->encap_size; | |
879 | ||
880 | skb_copy_from_linear_data_offset(skb, -data->size, data->mac, | |
881 | data->size); | |
882 | ||
8bd63cf1 | 883 | ret = ip_fragment(skb, br_nf_push_frag_xmit); |
e70deecb | 884 | } else { |
462fb2af | 885 | ret = br_dev_queue_push_xmit(skb); |
e70deecb | 886 | } |
462fb2af BD |
887 | |
888 | return ret; | |
2e2f7aef | 889 | } |
c197facc | 890 | #else |
891 | static int br_nf_dev_queue_xmit(struct sk_buff *skb) | |
892 | { | |
893 | return br_dev_queue_push_xmit(skb); | |
894 | } | |
895 | #endif | |
1da177e4 LT |
896 | |
897 | /* PF_BRIDGE/POST_ROUTING ********************************************/ | |
795aa6ef PM |
898 | static unsigned int br_nf_post_routing(const struct nf_hook_ops *ops, |
899 | struct sk_buff *skb, | |
789bc3e5 SH |
900 | const struct net_device *in, |
901 | const struct net_device *out, | |
902 | int (*okfn)(struct sk_buff *)) | |
1da177e4 | 903 | { |
38330783 | 904 | struct nf_bridge_info *nf_bridge = nf_bridge_info_get(skb); |
1da177e4 | 905 | struct net_device *realoutdev = bridge_parent(skb->dev); |
76108cea | 906 | u_int8_t pf; |
1da177e4 | 907 | |
e4bb9bcb FW |
908 | /* if nf_bridge is set, but ->physoutdev is NULL, this packet came in |
909 | * on a bridge, but was delivered locally and is now being routed: | |
910 | * | |
911 | * POST_ROUTING was already invoked from the ip stack. | |
912 | */ | |
913 | if (!nf_bridge || !nf_bridge->physoutdev) | |
81d9ddae PM |
914 | return NF_ACCEPT; |
915 | ||
5dce971a SH |
916 | if (!realoutdev) |
917 | return NF_DROP; | |
918 | ||
739e4505 | 919 | if (IS_IP(skb) || IS_VLAN_IP(skb) || IS_PPPOE_IP(skb)) |
aa740f46 | 920 | pf = NFPROTO_IPV4; |
739e4505 | 921 | else if (IS_IPV6(skb) || IS_VLAN_IPV6(skb) || IS_PPPOE_IPV6(skb)) |
aa740f46 | 922 | pf = NFPROTO_IPV6; |
a2bd40ad HX |
923 | else |
924 | return NF_ACCEPT; | |
1da177e4 | 925 | |
1da177e4 LT |
926 | /* We assume any code from br_dev_queue_push_xmit onwards doesn't care |
927 | * about the value of skb->pkt_type. */ | |
928 | if (skb->pkt_type == PACKET_OTHERHOST) { | |
929 | skb->pkt_type = PACKET_HOST; | |
930 | nf_bridge->mask |= BRNF_PKT_TYPE; | |
931 | } | |
932 | ||
fc38582d | 933 | nf_bridge_pull_encap_header(skb); |
aa740f46 | 934 | if (pf == NFPROTO_IPV4) |
e179e632 BDS |
935 | skb->protocol = htons(ETH_P_IP); |
936 | else | |
937 | skb->protocol = htons(ETH_P_IPV6); | |
1da177e4 | 938 | |
6e23ae2a | 939 | NF_HOOK(pf, NF_INET_POST_ROUTING, skb, NULL, realoutdev, |
2e2f7aef | 940 | br_nf_dev_queue_xmit); |
1da177e4 LT |
941 | |
942 | return NF_STOLEN; | |
1da177e4 LT |
943 | } |
944 | ||
1da177e4 LT |
945 | /* IP/SABOTAGE *****************************************************/ |
946 | /* Don't hand locally destined packets to PF_INET(6)/PRE_ROUTING | |
947 | * for the second time. */ | |
795aa6ef PM |
948 | static unsigned int ip_sabotage_in(const struct nf_hook_ops *ops, |
949 | struct sk_buff *skb, | |
789bc3e5 SH |
950 | const struct net_device *in, |
951 | const struct net_device *out, | |
952 | int (*okfn)(struct sk_buff *)) | |
1da177e4 | 953 | { |
3db05fea HX |
954 | if (skb->nf_bridge && |
955 | !(skb->nf_bridge->mask & BRNF_NF_BRIDGE_PREROUTING)) { | |
1da177e4 LT |
956 | return NF_STOP; |
957 | } | |
958 | ||
959 | return NF_ACCEPT; | |
960 | } | |
961 | ||
e5de75bf PNA |
962 | /* This is called when br_netfilter has called into iptables/netfilter, |
963 | * and DNAT has taken place on a bridge-forwarded packet. | |
964 | * | |
965 | * neigh->output has created a new MAC header, with local br0 MAC | |
966 | * as saddr. | |
967 | * | |
968 | * This restores the original MAC saddr of the bridged packet | |
969 | * before invoking bridge forward logic to transmit the packet. | |
970 | */ | |
971 | static void br_nf_pre_routing_finish_bridge_slow(struct sk_buff *skb) | |
972 | { | |
38330783 | 973 | struct nf_bridge_info *nf_bridge = nf_bridge_info_get(skb); |
e5de75bf PNA |
974 | |
975 | skb_pull(skb, ETH_HLEN); | |
976 | nf_bridge->mask &= ~BRNF_BRIDGED_DNAT; | |
977 | ||
e70deecb FW |
978 | BUILD_BUG_ON(sizeof(nf_bridge->neigh_header) != (ETH_HLEN - ETH_ALEN)); |
979 | ||
980 | skb_copy_to_linear_data_offset(skb, -(ETH_HLEN - ETH_ALEN), | |
981 | nf_bridge->neigh_header, | |
982 | ETH_HLEN - ETH_ALEN); | |
e5de75bf PNA |
983 | skb->dev = nf_bridge->physindev; |
984 | br_handle_frame_finish(skb); | |
985 | } | |
986 | ||
1a4ba64d | 987 | static int br_nf_dev_xmit(struct sk_buff *skb) |
e5de75bf PNA |
988 | { |
989 | if (skb->nf_bridge && (skb->nf_bridge->mask & BRNF_BRIDGED_DNAT)) { | |
990 | br_nf_pre_routing_finish_bridge_slow(skb); | |
991 | return 1; | |
992 | } | |
993 | return 0; | |
994 | } | |
1a4ba64d PNA |
995 | |
996 | static const struct nf_br_ops br_ops = { | |
997 | .br_dev_xmit_hook = br_nf_dev_xmit, | |
998 | }; | |
e5de75bf | 999 | |
4b7fd5d9 PNA |
1000 | void br_netfilter_enable(void) |
1001 | { | |
1002 | } | |
1003 | EXPORT_SYMBOL_GPL(br_netfilter_enable); | |
1004 | ||
ea2d9b41 BDS |
1005 | /* For br_nf_post_routing, we need (prio = NF_BR_PRI_LAST), because |
1006 | * br_dev_queue_push_xmit is called afterwards */ | |
1999414a | 1007 | static struct nf_hook_ops br_nf_ops[] __read_mostly = { |
1490fd89 CG |
1008 | { |
1009 | .hook = br_nf_pre_routing, | |
1010 | .owner = THIS_MODULE, | |
aa740f46 | 1011 | .pf = NFPROTO_BRIDGE, |
1490fd89 CG |
1012 | .hooknum = NF_BR_PRE_ROUTING, |
1013 | .priority = NF_BR_PRI_BRNF, | |
1014 | }, | |
1015 | { | |
1016 | .hook = br_nf_local_in, | |
1017 | .owner = THIS_MODULE, | |
aa740f46 | 1018 | .pf = NFPROTO_BRIDGE, |
1490fd89 CG |
1019 | .hooknum = NF_BR_LOCAL_IN, |
1020 | .priority = NF_BR_PRI_BRNF, | |
1021 | }, | |
1022 | { | |
1023 | .hook = br_nf_forward_ip, | |
1024 | .owner = THIS_MODULE, | |
aa740f46 | 1025 | .pf = NFPROTO_BRIDGE, |
1490fd89 CG |
1026 | .hooknum = NF_BR_FORWARD, |
1027 | .priority = NF_BR_PRI_BRNF - 1, | |
1028 | }, | |
1029 | { | |
1030 | .hook = br_nf_forward_arp, | |
1031 | .owner = THIS_MODULE, | |
aa740f46 | 1032 | .pf = NFPROTO_BRIDGE, |
1490fd89 CG |
1033 | .hooknum = NF_BR_FORWARD, |
1034 | .priority = NF_BR_PRI_BRNF, | |
1035 | }, | |
1490fd89 CG |
1036 | { |
1037 | .hook = br_nf_post_routing, | |
1038 | .owner = THIS_MODULE, | |
aa740f46 | 1039 | .pf = NFPROTO_BRIDGE, |
1490fd89 CG |
1040 | .hooknum = NF_BR_POST_ROUTING, |
1041 | .priority = NF_BR_PRI_LAST, | |
1042 | }, | |
1043 | { | |
1044 | .hook = ip_sabotage_in, | |
1045 | .owner = THIS_MODULE, | |
aa740f46 | 1046 | .pf = NFPROTO_IPV4, |
1490fd89 CG |
1047 | .hooknum = NF_INET_PRE_ROUTING, |
1048 | .priority = NF_IP_PRI_FIRST, | |
1049 | }, | |
1050 | { | |
1051 | .hook = ip_sabotage_in, | |
1052 | .owner = THIS_MODULE, | |
aa740f46 | 1053 | .pf = NFPROTO_IPV6, |
1490fd89 CG |
1054 | .hooknum = NF_INET_PRE_ROUTING, |
1055 | .priority = NF_IP6_PRI_FIRST, | |
1056 | }, | |
1da177e4 LT |
1057 | }; |
1058 | ||
1059 | #ifdef CONFIG_SYSCTL | |
1060 | static | |
fe2c6338 | 1061 | int brnf_sysctl_call_tables(struct ctl_table *ctl, int write, |
56b148eb | 1062 | void __user *buffer, size_t *lenp, loff_t *ppos) |
1da177e4 LT |
1063 | { |
1064 | int ret; | |
1065 | ||
8d65af78 | 1066 | ret = proc_dointvec(ctl, write, buffer, lenp, ppos); |
1da177e4 LT |
1067 | |
1068 | if (write && *(int *)(ctl->data)) | |
1069 | *(int *)(ctl->data) = 1; | |
1070 | return ret; | |
1071 | } | |
1072 | ||
fe2c6338 | 1073 | static struct ctl_table brnf_table[] = { |
1da177e4 | 1074 | { |
1da177e4 LT |
1075 | .procname = "bridge-nf-call-arptables", |
1076 | .data = &brnf_call_arptables, | |
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-iptables", |
1083 | .data = &brnf_call_iptables, | |
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-call-ip6tables", |
1090 | .data = &brnf_call_ip6tables, | |
1091 | .maxlen = sizeof(int), | |
1092 | .mode = 0644, | |
6d9f239a | 1093 | .proc_handler = brnf_sysctl_call_tables, |
1da177e4 LT |
1094 | }, |
1095 | { | |
1da177e4 LT |
1096 | .procname = "bridge-nf-filter-vlan-tagged", |
1097 | .data = &brnf_filter_vlan_tagged, | |
1098 | .maxlen = sizeof(int), | |
1099 | .mode = 0644, | |
6d9f239a | 1100 | .proc_handler = brnf_sysctl_call_tables, |
516299d2 MM |
1101 | }, |
1102 | { | |
516299d2 MM |
1103 | .procname = "bridge-nf-filter-pppoe-tagged", |
1104 | .data = &brnf_filter_pppoe_tagged, | |
1105 | .maxlen = sizeof(int), | |
1106 | .mode = 0644, | |
6d9f239a | 1107 | .proc_handler = brnf_sysctl_call_tables, |
1da177e4 | 1108 | }, |
4981682c PNA |
1109 | { |
1110 | .procname = "bridge-nf-pass-vlan-input-dev", | |
1111 | .data = &brnf_pass_vlan_indev, | |
1112 | .maxlen = sizeof(int), | |
1113 | .mode = 0644, | |
1114 | .proc_handler = brnf_sysctl_call_tables, | |
1115 | }, | |
f8572d8f | 1116 | { } |
1da177e4 | 1117 | }; |
1da177e4 LT |
1118 | #endif |
1119 | ||
34666d46 | 1120 | static int __init br_netfilter_init(void) |
1da177e4 | 1121 | { |
5eb87f45 | 1122 | int ret; |
1da177e4 | 1123 | |
34666d46 | 1124 | ret = nf_register_hooks(br_nf_ops, ARRAY_SIZE(br_nf_ops)); |
5eb87f45 | 1125 | if (ret < 0) |
1da177e4 | 1126 | return ret; |
fc66f95c | 1127 | |
1da177e4 | 1128 | #ifdef CONFIG_SYSCTL |
ec8f23ce | 1129 | brnf_sysctl_header = register_net_sysctl(&init_net, "net/bridge", brnf_table); |
1da177e4 | 1130 | if (brnf_sysctl_header == NULL) { |
789bc3e5 SH |
1131 | printk(KERN_WARNING |
1132 | "br_netfilter: can't register to sysctl.\n"); | |
96727239 GU |
1133 | nf_unregister_hooks(br_nf_ops, ARRAY_SIZE(br_nf_ops)); |
1134 | return -ENOMEM; | |
1da177e4 LT |
1135 | } |
1136 | #endif | |
1a4ba64d | 1137 | RCU_INIT_POINTER(nf_br_ops, &br_ops); |
1da177e4 | 1138 | printk(KERN_NOTICE "Bridge firewalling registered\n"); |
1da177e4 LT |
1139 | return 0; |
1140 | } | |
1141 | ||
34666d46 | 1142 | static void __exit br_netfilter_fini(void) |
1da177e4 | 1143 | { |
1a4ba64d | 1144 | RCU_INIT_POINTER(nf_br_ops, NULL); |
5eb87f45 | 1145 | nf_unregister_hooks(br_nf_ops, ARRAY_SIZE(br_nf_ops)); |
1da177e4 | 1146 | #ifdef CONFIG_SYSCTL |
5dd3df10 | 1147 | unregister_net_sysctl_table(brnf_sysctl_header); |
1da177e4 LT |
1148 | #endif |
1149 | } | |
34666d46 PNA |
1150 | |
1151 | module_init(br_netfilter_init); | |
1152 | module_exit(br_netfilter_fini); | |
1153 | ||
1154 | MODULE_LICENSE("GPL"); | |
1155 | MODULE_AUTHOR("Lennert Buytenhek <buytenh@gnu.org>"); | |
1156 | MODULE_AUTHOR("Bart De Schuymer <bdschuym@pandora.be>"); | |
1157 | MODULE_DESCRIPTION("Linux ethernet netfilter firewall bridge"); |