1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Handle firewalling
4 * Linux ethernet bridge
5 *
6 * Authors:
7 * Lennert Buytenhek <buytenh@gnu.org>
8 * Bart De Schuymer <bdschuym@pandora.be>
9 *
10 * Lennert dedicates this file to Kerstin Wurdinger.
11 */
12
13 #include <linux/module.h>
14 #include <linux/kernel.h>
15 #include <linux/slab.h>
16 #include <linux/ip.h>
17 #include <linux/netdevice.h>
18 #include <linux/skbuff.h>
19 #include <linux/if_arp.h>
20 #include <linux/if_ether.h>
21 #include <linux/if_vlan.h>
22 #include <linux/if_pppox.h>
23 #include <linux/ppp_defs.h>
24 #include <linux/netfilter_bridge.h>
25 #include <uapi/linux/netfilter_bridge.h>
26 #include <linux/netfilter_ipv4.h>
27 #include <linux/netfilter_ipv6.h>
28 #include <linux/netfilter_arp.h>
29 #include <linux/in_route.h>
30 #include <linux/rculist.h>
31 #include <linux/inetdevice.h>
32
33 #include <net/ip.h>
34 #include <net/ipv6.h>
35 #include <net/addrconf.h>
36 #include <net/route.h>
37 #include <net/netfilter/br_netfilter.h>
38 #include <net/netns/generic.h>
39
40 #include <linux/uaccess.h>
41 #include "br_private.h"
42 #ifdef CONFIG_SYSCTL
43 #include <linux/sysctl.h>
44 #endif
45
46 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
47 #include <net/netfilter/nf_conntrack_core.h>
48 #endif
49
50 static unsigned int brnf_net_id __read_mostly;
51
52 struct brnf_net {
53 bool enabled;
54
55 #ifdef CONFIG_SYSCTL
56 struct ctl_table_header *ctl_hdr;
57 #endif
58
59 /* default value is 1 */
60 int call_iptables;
61 int call_ip6tables;
62 int call_arptables;
63
64 /* default value is 0 */
65 int filter_vlan_tagged;
66 int filter_pppoe_tagged;
67 int pass_vlan_indev;
68 };
69
70 #define IS_IP(skb) \
71 (!skb_vlan_tag_present(skb) && skb->protocol == htons(ETH_P_IP))
72
73 #define IS_IPV6(skb) \
74 (!skb_vlan_tag_present(skb) && skb->protocol == htons(ETH_P_IPV6))
75
76 #define IS_ARP(skb) \
77 (!skb_vlan_tag_present(skb) && skb->protocol == htons(ETH_P_ARP))
78
vlan_proto(const struct sk_buff * skb)79 static inline __be16 vlan_proto(const struct sk_buff *skb)
80 {
81 if (skb_vlan_tag_present(skb))
82 return skb->protocol;
83 else if (skb->protocol == htons(ETH_P_8021Q))
84 return vlan_eth_hdr(skb)->h_vlan_encapsulated_proto;
85 else
86 return 0;
87 }
88
is_vlan_ip(const struct sk_buff * skb,const struct net * net)89 static inline bool is_vlan_ip(const struct sk_buff *skb, const struct net *net)
90 {
91 struct brnf_net *brnet = net_generic(net, brnf_net_id);
92
93 return vlan_proto(skb) == htons(ETH_P_IP) && brnet->filter_vlan_tagged;
94 }
95
is_vlan_ipv6(const struct sk_buff * skb,const struct net * net)96 static inline bool is_vlan_ipv6(const struct sk_buff *skb,
97 const struct net *net)
98 {
99 struct brnf_net *brnet = net_generic(net, brnf_net_id);
100
101 return vlan_proto(skb) == htons(ETH_P_IPV6) &&
102 brnet->filter_vlan_tagged;
103 }
104
is_vlan_arp(const struct sk_buff * skb,const struct net * net)105 static inline bool is_vlan_arp(const struct sk_buff *skb, const struct net *net)
106 {
107 struct brnf_net *brnet = net_generic(net, brnf_net_id);
108
109 return vlan_proto(skb) == htons(ETH_P_ARP) && brnet->filter_vlan_tagged;
110 }
111
pppoe_proto(const struct sk_buff * skb)112 static inline __be16 pppoe_proto(const struct sk_buff *skb)
113 {
114 return *((__be16 *)(skb_mac_header(skb) + ETH_HLEN +
115 sizeof(struct pppoe_hdr)));
116 }
117
is_pppoe_ip(const struct sk_buff * skb,const struct net * net)118 static inline bool is_pppoe_ip(const struct sk_buff *skb, const struct net *net)
119 {
120 struct brnf_net *brnet = net_generic(net, brnf_net_id);
121
122 return skb->protocol == htons(ETH_P_PPP_SES) &&
123 pppoe_proto(skb) == htons(PPP_IP) && brnet->filter_pppoe_tagged;
124 }
125
is_pppoe_ipv6(const struct sk_buff * skb,const struct net * net)126 static inline bool is_pppoe_ipv6(const struct sk_buff *skb,
127 const struct net *net)
128 {
129 struct brnf_net *brnet = net_generic(net, brnf_net_id);
130
131 return skb->protocol == htons(ETH_P_PPP_SES) &&
132 pppoe_proto(skb) == htons(PPP_IPV6) &&
133 brnet->filter_pppoe_tagged;
134 }
135
136 /* largest possible L2 header, see br_nf_dev_queue_xmit() */
137 #define NF_BRIDGE_MAX_MAC_HEADER_LENGTH (PPPOE_SES_HLEN + ETH_HLEN)
138
139 struct brnf_frag_data {
140 char mac[NF_BRIDGE_MAX_MAC_HEADER_LENGTH];
141 u8 encap_size;
142 u8 size;
143 u16 vlan_tci;
144 __be16 vlan_proto;
145 };
146
147 static DEFINE_PER_CPU(struct brnf_frag_data, brnf_frag_data_storage);
148
nf_bridge_info_free(struct sk_buff * skb)149 static void nf_bridge_info_free(struct sk_buff *skb)
150 {
151 skb_ext_del(skb, SKB_EXT_BRIDGE_NF);
152 }
153
bridge_parent(const struct net_device * dev)154 static inline struct net_device *bridge_parent(const struct net_device *dev)
155 {
156 struct net_bridge_port *port;
157
158 port = br_port_get_rcu(dev);
159 return port ? port->br->dev : NULL;
160 }
161
nf_bridge_unshare(struct sk_buff * skb)162 static inline struct nf_bridge_info *nf_bridge_unshare(struct sk_buff *skb)
163 {
164 return skb_ext_add(skb, SKB_EXT_BRIDGE_NF);
165 }
166
nf_bridge_encap_header_len(const struct sk_buff * skb)167 unsigned int nf_bridge_encap_header_len(const struct sk_buff *skb)
168 {
169 switch (skb->protocol) {
170 case __cpu_to_be16(ETH_P_8021Q):
171 return VLAN_HLEN;
172 case __cpu_to_be16(ETH_P_PPP_SES):
173 return PPPOE_SES_HLEN;
174 default:
175 return 0;
176 }
177 }
178
nf_bridge_pull_encap_header(struct sk_buff * skb)179 static inline void nf_bridge_pull_encap_header(struct sk_buff *skb)
180 {
181 unsigned int len = nf_bridge_encap_header_len(skb);
182
183 skb_pull(skb, len);
184 skb->network_header += len;
185 }
186
nf_bridge_pull_encap_header_rcsum(struct sk_buff * skb)187 static inline void nf_bridge_pull_encap_header_rcsum(struct sk_buff *skb)
188 {
189 unsigned int len = nf_bridge_encap_header_len(skb);
190
191 skb_pull_rcsum(skb, len);
192 skb->network_header += len;
193 }
194
195 /* When handing a packet over to the IP layer
196 * check whether we have a skb that is in the
197 * expected format
198 */
199
br_validate_ipv4(struct net * net,struct sk_buff * skb)200 static int br_validate_ipv4(struct net *net, struct sk_buff *skb)
201 {
202 const struct iphdr *iph;
203 u32 len;
204
205 if (!pskb_may_pull(skb, sizeof(struct iphdr)))
206 goto inhdr_error;
207
208 iph = ip_hdr(skb);
209
210 /* Basic sanity checks */
211 if (iph->ihl < 5 || iph->version != 4)
212 goto inhdr_error;
213
214 if (!pskb_may_pull(skb, iph->ihl*4))
215 goto inhdr_error;
216
217 iph = ip_hdr(skb);
218 if (unlikely(ip_fast_csum((u8 *)iph, iph->ihl)))
219 goto csum_error;
220
221 len = skb_ip_totlen(skb);
222 if (skb->len < len) {
223 __IP_INC_STATS(net, IPSTATS_MIB_INTRUNCATEDPKTS);
224 goto drop;
225 } else if (len < (iph->ihl*4))
226 goto inhdr_error;
227
228 if (pskb_trim_rcsum(skb, len)) {
229 __IP_INC_STATS(net, IPSTATS_MIB_INDISCARDS);
230 goto drop;
231 }
232
233 memset(IPCB(skb), 0, sizeof(struct inet_skb_parm));
234 /* We should really parse IP options here but until
235 * somebody who actually uses IP options complains to
236 * us we'll just silently ignore the options because
237 * we're lazy!
238 */
239 return 0;
240
241 csum_error:
242 __IP_INC_STATS(net, IPSTATS_MIB_CSUMERRORS);
243 inhdr_error:
244 __IP_INC_STATS(net, IPSTATS_MIB_INHDRERRORS);
245 drop:
246 return -1;
247 }
248
nf_bridge_update_protocol(struct sk_buff * skb)249 void nf_bridge_update_protocol(struct sk_buff *skb)
250 {
251 const struct nf_bridge_info *nf_bridge = nf_bridge_info_get(skb);
252
253 switch (nf_bridge->orig_proto) {
254 case BRNF_PROTO_8021Q:
255 skb->protocol = htons(ETH_P_8021Q);
256 break;
257 case BRNF_PROTO_PPPOE:
258 skb->protocol = htons(ETH_P_PPP_SES);
259 break;
260 case BRNF_PROTO_UNCHANGED:
261 break;
262 }
263 }
264
265 /* Obtain the correct destination MAC address, while preserving the original
266 * source MAC address. If we already know this address, we just copy it. If we
267 * don't, we use the neighbour framework to find out. In both cases, we make
268 * sure that br_handle_frame_finish() is called afterwards.
269 */
br_nf_pre_routing_finish_bridge(struct net * net,struct sock * sk,struct sk_buff * skb)270 int br_nf_pre_routing_finish_bridge(struct net *net, struct sock *sk, struct sk_buff *skb)
271 {
272 struct neighbour *neigh;
273 struct dst_entry *dst;
274
275 skb->dev = bridge_parent(skb->dev);
276 if (!skb->dev)
277 goto free_skb;
278 dst = skb_dst(skb);
279 neigh = dst_neigh_lookup_skb(dst, skb);
280 if (neigh) {
281 struct nf_bridge_info *nf_bridge = nf_bridge_info_get(skb);
282 int ret;
283
284 if ((READ_ONCE(neigh->nud_state) & NUD_CONNECTED) &&
285 READ_ONCE(neigh->hh.hh_len)) {
286 struct net_device *br_indev;
287
288 br_indev = nf_bridge_get_physindev(skb, net);
289 if (!br_indev) {
290 neigh_release(neigh);
291 goto free_skb;
292 }
293
294 neigh_hh_bridge(&neigh->hh, skb);
295 skb->dev = br_indev;
296
297 ret = br_handle_frame_finish(net, sk, skb);
298 } else {
299 /* the neighbour function below overwrites the complete
300 * MAC header, so we save the Ethernet source address and
301 * protocol number.
302 */
303 skb_copy_from_linear_data_offset(skb,
304 -(ETH_HLEN-ETH_ALEN),
305 nf_bridge->neigh_header,
306 ETH_HLEN-ETH_ALEN);
307 /* tell br_dev_xmit to continue with forwarding */
308 nf_bridge->bridged_dnat = 1;
309 /* FIXME Need to refragment */
310 ret = READ_ONCE(neigh->output)(neigh, skb);
311 }
312 neigh_release(neigh);
313 return ret;
314 }
315 free_skb:
316 kfree_skb(skb);
317 return 0;
318 }
319
320 static inline bool
br_nf_ipv4_daddr_was_changed(const struct sk_buff * skb,const struct nf_bridge_info * nf_bridge)321 br_nf_ipv4_daddr_was_changed(const struct sk_buff *skb,
322 const struct nf_bridge_info *nf_bridge)
323 {
324 return ip_hdr(skb)->daddr != nf_bridge->ipv4_daddr;
325 }
326
327 /* This requires some explaining. If DNAT has taken place,
328 * we will need to fix up the destination Ethernet address.
329 * This is also true when SNAT takes place (for the reply direction).
330 *
331 * There are two cases to consider:
332 * 1. The packet was DNAT'ed to a device in the same bridge
333 * port group as it was received on. We can still bridge
334 * the packet.
335 * 2. The packet was DNAT'ed to a different device, either
336 * a non-bridged device or another bridge port group.
337 * The packet will need to be routed.
338 *
339 * The correct way of distinguishing between these two cases is to
340 * call ip_route_input() and to look at skb->dst->dev, which is
341 * changed to the destination device if ip_route_input() succeeds.
342 *
343 * Let's first consider the case that ip_route_input() succeeds:
344 *
345 * If the output device equals the logical bridge device the packet
346 * came in on, we can consider this bridging. The corresponding MAC
347 * address will be obtained in br_nf_pre_routing_finish_bridge.
348 * Otherwise, the packet is considered to be routed and we just
349 * change the destination MAC address so that the packet will
350 * later be passed up to the IP stack to be routed. For a redirected
351 * packet, ip_route_input() will give back the localhost as output device,
352 * which differs from the bridge device.
353 *
354 * Let's now consider the case that ip_route_input() fails:
355 *
356 * This can be because the destination address is martian, in which case
357 * the packet will be dropped.
358 * If IP forwarding is disabled, ip_route_input() will fail, while
359 * ip_route_output_key() can return success. The source
360 * address for ip_route_output_key() is set to zero, so ip_route_output_key()
361 * thinks we're handling a locally generated packet and won't care
362 * if IP forwarding is enabled. If the output device equals the logical bridge
363 * device, we proceed as if ip_route_input() succeeded. If it differs from the
364 * logical bridge port or if ip_route_output_key() fails we drop the packet.
365 */
br_nf_pre_routing_finish(struct net * net,struct sock * sk,struct sk_buff * skb)366 static int br_nf_pre_routing_finish(struct net *net, struct sock *sk, struct sk_buff *skb)
367 {
368 struct net_device *dev = skb->dev, *br_indev;
369 struct iphdr *iph = ip_hdr(skb);
370 struct nf_bridge_info *nf_bridge = nf_bridge_info_get(skb);
371 struct rtable *rt;
372 int err;
373
374 br_indev = nf_bridge_get_physindev(skb, net);
375 if (!br_indev) {
376 kfree_skb(skb);
377 return 0;
378 }
379
380 nf_bridge->frag_max_size = IPCB(skb)->frag_max_size;
381
382 if (nf_bridge->pkt_otherhost) {
383 skb->pkt_type = PACKET_OTHERHOST;
384 nf_bridge->pkt_otherhost = false;
385 }
386 nf_bridge->in_prerouting = 0;
387 if (br_nf_ipv4_daddr_was_changed(skb, nf_bridge)) {
388 if ((err = ip_route_input(skb, iph->daddr, iph->saddr, iph->tos, dev))) {
389 struct in_device *in_dev = __in_dev_get_rcu(dev);
390
391 /* If err equals -EHOSTUNREACH the error is due to a
392 * martian destination or due to the fact that
393 * forwarding is disabled. For most martian packets,
394 * ip_route_output_key() will fail. It won't fail for 2 types of
395 * martian destinations: loopback destinations and destination
396 * 0.0.0.0. In both cases the packet will be dropped because the
397 * destination is the loopback device and not the bridge. */
398 if (err != -EHOSTUNREACH || !in_dev || IN_DEV_FORWARD(in_dev))
399 goto free_skb;
400
401 rt = ip_route_output(net, iph->daddr, 0,
402 RT_TOS(iph->tos), 0);
403 if (!IS_ERR(rt)) {
404 /* - Bridged-and-DNAT'ed traffic doesn't
405 * require ip_forwarding. */
406 if (rt->dst.dev == dev) {
407 skb_dst_drop(skb);
408 skb_dst_set(skb, &rt->dst);
409 goto bridged_dnat;
410 }
411 ip_rt_put(rt);
412 }
413 free_skb:
414 kfree_skb(skb);
415 return 0;
416 } else {
417 if (skb_dst(skb)->dev == dev) {
418 bridged_dnat:
419 skb->dev = br_indev;
420 nf_bridge_update_protocol(skb);
421 nf_bridge_push_encap_header(skb);
422 br_nf_hook_thresh(NF_BR_PRE_ROUTING,
423 net, sk, skb, skb->dev,
424 NULL,
425 br_nf_pre_routing_finish_bridge);
426 return 0;
427 }
428 ether_addr_copy(eth_hdr(skb)->h_dest, dev->dev_addr);
429 skb->pkt_type = PACKET_HOST;
430 }
431 } else {
432 rt = bridge_parent_rtable(br_indev);
433 if (!rt) {
434 kfree_skb(skb);
435 return 0;
436 }
437 skb_dst_drop(skb);
438 skb_dst_set_noref(skb, &rt->dst);
439 }
440
441 skb->dev = br_indev;
442 nf_bridge_update_protocol(skb);
443 nf_bridge_push_encap_header(skb);
444 br_nf_hook_thresh(NF_BR_PRE_ROUTING, net, sk, skb, skb->dev, NULL,
445 br_handle_frame_finish);
446 return 0;
447 }
448
brnf_get_logical_dev(struct sk_buff * skb,const struct net_device * dev,const struct net * net)449 static struct net_device *brnf_get_logical_dev(struct sk_buff *skb,
450 const struct net_device *dev,
451 const struct net *net)
452 {
453 struct net_device *vlan, *br;
454 struct brnf_net *brnet = net_generic(net, brnf_net_id);
455
456 br = bridge_parent(dev);
457
458 if (brnet->pass_vlan_indev == 0 || !skb_vlan_tag_present(skb))
459 return br;
460
461 vlan = __vlan_find_dev_deep_rcu(br, skb->vlan_proto,
462 skb_vlan_tag_get(skb) & VLAN_VID_MASK);
463
464 return vlan ? vlan : br;
465 }
466
467 /* Some common code for IPv4/IPv6 */
setup_pre_routing(struct sk_buff * skb,const struct net * net)468 struct net_device *setup_pre_routing(struct sk_buff *skb, const struct net *net)
469 {
470 struct nf_bridge_info *nf_bridge = nf_bridge_info_get(skb);
471
472 if (skb->pkt_type == PACKET_OTHERHOST) {
473 skb->pkt_type = PACKET_HOST;
474 nf_bridge->pkt_otherhost = true;
475 }
476
477 nf_bridge->in_prerouting = 1;
478 nf_bridge->physinif = skb->dev->ifindex;
479 skb->dev = brnf_get_logical_dev(skb, skb->dev, net);
480
481 if (skb->protocol == htons(ETH_P_8021Q))
482 nf_bridge->orig_proto = BRNF_PROTO_8021Q;
483 else if (skb->protocol == htons(ETH_P_PPP_SES))
484 nf_bridge->orig_proto = BRNF_PROTO_PPPOE;
485
486 /* Must drop socket now because of tproxy. */
487 skb_orphan(skb);
488 return skb->dev;
489 }
490
491 /* Direct IPv6 traffic to br_nf_pre_routing_ipv6.
492 * Replicate the checks that IPv4 does on packet reception.
493 * Set skb->dev to the bridge device (i.e. parent of the
494 * receiving device) to make netfilter happy, the REDIRECT
495 * target in particular. Save the original destination IP
496 * address to be able to detect DNAT afterwards. */
br_nf_pre_routing(void * priv,struct sk_buff * skb,const struct nf_hook_state * state)497 static unsigned int br_nf_pre_routing(void *priv,
498 struct sk_buff *skb,
499 const struct nf_hook_state *state)
500 {
501 struct nf_bridge_info *nf_bridge;
502 struct net_bridge_port *p;
503 struct net_bridge *br;
504 __u32 len = nf_bridge_encap_header_len(skb);
505 struct brnf_net *brnet;
506
507 if (unlikely(!pskb_may_pull(skb, len)))
508 return NF_DROP;
509
510 p = br_port_get_rcu(state->in);
511 if (p == NULL)
512 return NF_DROP;
513 br = p->br;
514
515 brnet = net_generic(state->net, brnf_net_id);
516 if (IS_IPV6(skb) || is_vlan_ipv6(skb, state->net) ||
517 is_pppoe_ipv6(skb, state->net)) {
518 if (!brnet->call_ip6tables &&
519 !br_opt_get(br, BROPT_NF_CALL_IP6TABLES))
520 return NF_ACCEPT;
521 if (!ipv6_mod_enabled()) {
522 pr_warn_once("Module ipv6 is disabled, so call_ip6tables is not supported.");
523 return NF_DROP;
524 }
525
526 nf_bridge_pull_encap_header_rcsum(skb);
527 return br_nf_pre_routing_ipv6(priv, skb, state);
528 }
529
530 if (!brnet->call_iptables && !br_opt_get(br, BROPT_NF_CALL_IPTABLES))
531 return NF_ACCEPT;
532
533 if (!IS_IP(skb) && !is_vlan_ip(skb, state->net) &&
534 !is_pppoe_ip(skb, state->net))
535 return NF_ACCEPT;
536
537 nf_bridge_pull_encap_header_rcsum(skb);
538
539 if (br_validate_ipv4(state->net, skb))
540 return NF_DROP;
541
542 if (!nf_bridge_alloc(skb))
543 return NF_DROP;
544 if (!setup_pre_routing(skb, state->net))
545 return NF_DROP;
546
547 nf_bridge = nf_bridge_info_get(skb);
548 nf_bridge->ipv4_daddr = ip_hdr(skb)->daddr;
549
550 skb->protocol = htons(ETH_P_IP);
551 skb->transport_header = skb->network_header + ip_hdr(skb)->ihl * 4;
552
553 NF_HOOK(NFPROTO_IPV4, NF_INET_PRE_ROUTING, state->net, state->sk, skb,
554 skb->dev, NULL,
555 br_nf_pre_routing_finish);
556
557 return NF_STOLEN;
558 }
559
560 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
561 /* conntracks' nf_confirm logic cannot handle cloned skbs referencing
562 * the same nf_conn entry, which will happen for multicast (broadcast)
563 * Frames on bridges.
564 *
565 * Example:
566 * macvlan0
567 * br0
568 * ethX ethY
569 *
570 * ethX (or Y) receives multicast or broadcast packet containing
571 * an IP packet, not yet in conntrack table.
572 *
573 * 1. skb passes through bridge and fake-ip (br_netfilter)Prerouting.
574 * -> skb->_nfct now references a unconfirmed entry
575 * 2. skb is broad/mcast packet. bridge now passes clones out on each bridge
576 * interface.
577 * 3. skb gets passed up the stack.
578 * 4. In macvlan case, macvlan driver retains clone(s) of the mcast skb
579 * and schedules a work queue to send them out on the lower devices.
580 *
581 * The clone skb->_nfct is not a copy, it is the same entry as the
582 * original skb. The macvlan rx handler then returns RX_HANDLER_PASS.
583 * 5. Normal conntrack hooks (in NF_INET_LOCAL_IN) confirm the orig skb.
584 *
585 * The Macvlan broadcast worker and normal confirm path will race.
586 *
587 * This race will not happen if step 2 already confirmed a clone. In that
588 * case later steps perform skb_clone() with skb->_nfct already confirmed (in
589 * hash table). This works fine.
590 *
591 * But such confirmation won't happen when eb/ip/nftables rules dropped the
592 * packets before they reached the nf_confirm step in postrouting.
593 *
594 * Work around this problem by explicit confirmation of the entry at
595 * LOCAL_IN time, before upper layer has a chance to clone the unconfirmed
596 * entry.
597 *
598 */
br_nf_local_in(void * priv,struct sk_buff * skb,const struct nf_hook_state * state)599 static unsigned int br_nf_local_in(void *priv,
600 struct sk_buff *skb,
601 const struct nf_hook_state *state)
602 {
603 bool promisc = BR_INPUT_SKB_CB(skb)->promisc;
604 struct nf_conntrack *nfct = skb_nfct(skb);
605 const struct nf_ct_hook *ct_hook;
606 struct nf_conn *ct;
607 int ret;
608
609 if (promisc) {
610 nf_reset_ct(skb);
611 return NF_ACCEPT;
612 }
613
614 if (!nfct || skb->pkt_type == PACKET_HOST)
615 return NF_ACCEPT;
616
617 ct = container_of(nfct, struct nf_conn, ct_general);
618 if (likely(nf_ct_is_confirmed(ct)))
619 return NF_ACCEPT;
620
621 WARN_ON_ONCE(skb_shared(skb));
622 WARN_ON_ONCE(refcount_read(&nfct->use) != 1);
623
624 /* We can't call nf_confirm here, it would create a dependency
625 * on nf_conntrack module.
626 */
627 ct_hook = rcu_dereference(nf_ct_hook);
628 if (!ct_hook) {
629 skb->_nfct = 0ul;
630 nf_conntrack_put(nfct);
631 return NF_ACCEPT;
632 }
633
634 nf_bridge_pull_encap_header(skb);
635 ret = ct_hook->confirm(skb);
636 switch (ret & NF_VERDICT_MASK) {
637 case NF_STOLEN:
638 return NF_STOLEN;
639 default:
640 nf_bridge_push_encap_header(skb);
641 break;
642 }
643
644 ct = container_of(nfct, struct nf_conn, ct_general);
645 WARN_ON_ONCE(!nf_ct_is_confirmed(ct));
646
647 return ret;
648 }
649 #endif
650
651 /* PF_BRIDGE/FORWARD *************************************************/
br_nf_forward_finish(struct net * net,struct sock * sk,struct sk_buff * skb)652 static int br_nf_forward_finish(struct net *net, struct sock *sk, struct sk_buff *skb)
653 {
654 struct nf_bridge_info *nf_bridge = nf_bridge_info_get(skb);
655 struct net_device *in;
656
657 if (!IS_ARP(skb) && !is_vlan_arp(skb, net)) {
658
659 if (skb->protocol == htons(ETH_P_IP))
660 nf_bridge->frag_max_size = IPCB(skb)->frag_max_size;
661
662 if (skb->protocol == htons(ETH_P_IPV6))
663 nf_bridge->frag_max_size = IP6CB(skb)->frag_max_size;
664
665 in = nf_bridge_get_physindev(skb, net);
666 if (!in) {
667 kfree_skb(skb);
668 return 0;
669 }
670 if (nf_bridge->pkt_otherhost) {
671 skb->pkt_type = PACKET_OTHERHOST;
672 nf_bridge->pkt_otherhost = false;
673 }
674 nf_bridge_update_protocol(skb);
675 } else {
676 in = *((struct net_device **)(skb->cb));
677 }
678 nf_bridge_push_encap_header(skb);
679
680 br_nf_hook_thresh(NF_BR_FORWARD, net, sk, skb, in, skb->dev,
681 br_forward_finish);
682 return 0;
683 }
684
685
686 /* This is the 'purely bridged' case. For IP, we pass the packet to
687 * netfilter with indev and outdev set to the bridge device,
688 * but we are still able to filter on the 'real' indev/outdev
689 * because of the physdev module. For ARP, indev and outdev are the
690 * bridge ports. */
br_nf_forward_ip(void * priv,struct sk_buff * skb,const struct nf_hook_state * state)691 static unsigned int br_nf_forward_ip(void *priv,
692 struct sk_buff *skb,
693 const struct nf_hook_state *state)
694 {
695 struct nf_bridge_info *nf_bridge;
696 struct net_device *parent;
697 u_int8_t pf;
698
699 nf_bridge = nf_bridge_info_get(skb);
700 if (!nf_bridge)
701 return NF_ACCEPT;
702
703 /* Need exclusive nf_bridge_info since we might have multiple
704 * different physoutdevs. */
705 if (!nf_bridge_unshare(skb))
706 return NF_DROP;
707
708 nf_bridge = nf_bridge_info_get(skb);
709 if (!nf_bridge)
710 return NF_DROP;
711
712 parent = bridge_parent(state->out);
713 if (!parent)
714 return NF_DROP;
715
716 if (IS_IP(skb) || is_vlan_ip(skb, state->net) ||
717 is_pppoe_ip(skb, state->net))
718 pf = NFPROTO_IPV4;
719 else if (IS_IPV6(skb) || is_vlan_ipv6(skb, state->net) ||
720 is_pppoe_ipv6(skb, state->net))
721 pf = NFPROTO_IPV6;
722 else
723 return NF_ACCEPT;
724
725 nf_bridge_pull_encap_header(skb);
726
727 if (skb->pkt_type == PACKET_OTHERHOST) {
728 skb->pkt_type = PACKET_HOST;
729 nf_bridge->pkt_otherhost = true;
730 }
731
732 if (pf == NFPROTO_IPV4) {
733 if (br_validate_ipv4(state->net, skb))
734 return NF_DROP;
735 IPCB(skb)->frag_max_size = nf_bridge->frag_max_size;
736 }
737
738 if (pf == NFPROTO_IPV6) {
739 if (br_validate_ipv6(state->net, skb))
740 return NF_DROP;
741 IP6CB(skb)->frag_max_size = nf_bridge->frag_max_size;
742 }
743
744 nf_bridge->physoutdev = skb->dev;
745 if (pf == NFPROTO_IPV4)
746 skb->protocol = htons(ETH_P_IP);
747 else
748 skb->protocol = htons(ETH_P_IPV6);
749
750 NF_HOOK(pf, NF_INET_FORWARD, state->net, NULL, skb,
751 brnf_get_logical_dev(skb, state->in, state->net),
752 parent, br_nf_forward_finish);
753
754 return NF_STOLEN;
755 }
756
br_nf_forward_arp(void * priv,struct sk_buff * skb,const struct nf_hook_state * state)757 static unsigned int br_nf_forward_arp(void *priv,
758 struct sk_buff *skb,
759 const struct nf_hook_state *state)
760 {
761 struct net_bridge_port *p;
762 struct net_bridge *br;
763 struct net_device **d = (struct net_device **)(skb->cb);
764 struct brnf_net *brnet;
765
766 p = br_port_get_rcu(state->out);
767 if (p == NULL)
768 return NF_ACCEPT;
769 br = p->br;
770
771 brnet = net_generic(state->net, brnf_net_id);
772 if (!brnet->call_arptables && !br_opt_get(br, BROPT_NF_CALL_ARPTABLES))
773 return NF_ACCEPT;
774
775 if (!IS_ARP(skb)) {
776 if (!is_vlan_arp(skb, state->net))
777 return NF_ACCEPT;
778 nf_bridge_pull_encap_header(skb);
779 }
780
781 if (unlikely(!pskb_may_pull(skb, sizeof(struct arphdr))))
782 return NF_DROP;
783
784 if (arp_hdr(skb)->ar_pln != 4) {
785 if (is_vlan_arp(skb, state->net))
786 nf_bridge_push_encap_header(skb);
787 return NF_ACCEPT;
788 }
789 *d = state->in;
790 NF_HOOK(NFPROTO_ARP, NF_ARP_FORWARD, state->net, state->sk, skb,
791 state->in, state->out, br_nf_forward_finish);
792
793 return NF_STOLEN;
794 }
795
br_nf_push_frag_xmit(struct net * net,struct sock * sk,struct sk_buff * skb)796 static int br_nf_push_frag_xmit(struct net *net, struct sock *sk, struct sk_buff *skb)
797 {
798 struct brnf_frag_data *data;
799 int err;
800
801 data = this_cpu_ptr(&brnf_frag_data_storage);
802 err = skb_cow_head(skb, data->size);
803
804 if (err) {
805 kfree_skb(skb);
806 return 0;
807 }
808
809 if (data->vlan_proto)
810 __vlan_hwaccel_put_tag(skb, data->vlan_proto, data->vlan_tci);
811
812 skb_copy_to_linear_data_offset(skb, -data->size, data->mac, data->size);
813 __skb_push(skb, data->encap_size);
814
815 nf_bridge_info_free(skb);
816 return br_dev_queue_push_xmit(net, sk, skb);
817 }
818
819 static int
br_nf_ip_fragment(struct net * net,struct sock * sk,struct sk_buff * skb,int (* output)(struct net *,struct sock *,struct sk_buff *))820 br_nf_ip_fragment(struct net *net, struct sock *sk, struct sk_buff *skb,
821 int (*output)(struct net *, struct sock *, struct sk_buff *))
822 {
823 unsigned int mtu = ip_skb_dst_mtu(sk, skb);
824 struct iphdr *iph = ip_hdr(skb);
825
826 if (unlikely(((iph->frag_off & htons(IP_DF)) && !skb->ignore_df) ||
827 (IPCB(skb)->frag_max_size &&
828 IPCB(skb)->frag_max_size > mtu))) {
829 IP_INC_STATS(net, IPSTATS_MIB_FRAGFAILS);
830 kfree_skb(skb);
831 return -EMSGSIZE;
832 }
833
834 return ip_do_fragment(net, sk, skb, output);
835 }
836
nf_bridge_mtu_reduction(const struct sk_buff * skb)837 static unsigned int nf_bridge_mtu_reduction(const struct sk_buff *skb)
838 {
839 const struct nf_bridge_info *nf_bridge = nf_bridge_info_get(skb);
840
841 if (nf_bridge->orig_proto == BRNF_PROTO_PPPOE)
842 return PPPOE_SES_HLEN;
843 return 0;
844 }
845
br_nf_dev_queue_xmit(struct net * net,struct sock * sk,struct sk_buff * skb)846 static int br_nf_dev_queue_xmit(struct net *net, struct sock *sk, struct sk_buff *skb)
847 {
848 struct nf_bridge_info *nf_bridge = nf_bridge_info_get(skb);
849 unsigned int mtu, mtu_reserved;
850
851 mtu_reserved = nf_bridge_mtu_reduction(skb);
852 mtu = skb->dev->mtu;
853
854 if (nf_bridge->pkt_otherhost) {
855 skb->pkt_type = PACKET_OTHERHOST;
856 nf_bridge->pkt_otherhost = false;
857 }
858
859 if (nf_bridge->frag_max_size && nf_bridge->frag_max_size < mtu)
860 mtu = nf_bridge->frag_max_size;
861
862 nf_bridge_update_protocol(skb);
863 nf_bridge_push_encap_header(skb);
864
865 if (skb_is_gso(skb) || skb->len + mtu_reserved <= mtu) {
866 nf_bridge_info_free(skb);
867 return br_dev_queue_push_xmit(net, sk, skb);
868 }
869
870 /* This is wrong! We should preserve the original fragment
871 * boundaries by preserving frag_list rather than refragmenting.
872 */
873 if (IS_ENABLED(CONFIG_NF_DEFRAG_IPV4) &&
874 skb->protocol == htons(ETH_P_IP)) {
875 struct brnf_frag_data *data;
876
877 if (br_validate_ipv4(net, skb))
878 goto drop;
879
880 IPCB(skb)->frag_max_size = nf_bridge->frag_max_size;
881
882 data = this_cpu_ptr(&brnf_frag_data_storage);
883
884 if (skb_vlan_tag_present(skb)) {
885 data->vlan_tci = skb->vlan_tci;
886 data->vlan_proto = skb->vlan_proto;
887 } else {
888 data->vlan_proto = 0;
889 }
890
891 data->encap_size = nf_bridge_encap_header_len(skb);
892 data->size = ETH_HLEN + data->encap_size;
893
894 skb_copy_from_linear_data_offset(skb, -data->size, data->mac,
895 data->size);
896
897 return br_nf_ip_fragment(net, sk, skb, br_nf_push_frag_xmit);
898 }
899 if (IS_ENABLED(CONFIG_NF_DEFRAG_IPV6) &&
900 skb->protocol == htons(ETH_P_IPV6)) {
901 const struct nf_ipv6_ops *v6ops = nf_get_ipv6_ops();
902 struct brnf_frag_data *data;
903
904 if (br_validate_ipv6(net, skb))
905 goto drop;
906
907 IP6CB(skb)->frag_max_size = nf_bridge->frag_max_size;
908
909 data = this_cpu_ptr(&brnf_frag_data_storage);
910 data->encap_size = nf_bridge_encap_header_len(skb);
911 data->size = ETH_HLEN + data->encap_size;
912
913 skb_copy_from_linear_data_offset(skb, -data->size, data->mac,
914 data->size);
915
916 if (v6ops)
917 return v6ops->fragment(net, sk, skb, br_nf_push_frag_xmit);
918
919 kfree_skb(skb);
920 return -EMSGSIZE;
921 }
922 nf_bridge_info_free(skb);
923 return br_dev_queue_push_xmit(net, sk, skb);
924 drop:
925 kfree_skb(skb);
926 return 0;
927 }
928
929 /* PF_BRIDGE/POST_ROUTING ********************************************/
br_nf_post_routing(void * priv,struct sk_buff * skb,const struct nf_hook_state * state)930 static unsigned int br_nf_post_routing(void *priv,
931 struct sk_buff *skb,
932 const struct nf_hook_state *state)
933 {
934 struct nf_bridge_info *nf_bridge = nf_bridge_info_get(skb);
935 struct net_device *realoutdev = bridge_parent(skb->dev);
936 u_int8_t pf;
937
938 /* if nf_bridge is set, but ->physoutdev is NULL, this packet came in
939 * on a bridge, but was delivered locally and is now being routed:
940 *
941 * POST_ROUTING was already invoked from the ip stack.
942 */
943 if (!nf_bridge || !nf_bridge->physoutdev)
944 return NF_ACCEPT;
945
946 if (!realoutdev)
947 return NF_DROP;
948
949 if (IS_IP(skb) || is_vlan_ip(skb, state->net) ||
950 is_pppoe_ip(skb, state->net))
951 pf = NFPROTO_IPV4;
952 else if (IS_IPV6(skb) || is_vlan_ipv6(skb, state->net) ||
953 is_pppoe_ipv6(skb, state->net))
954 pf = NFPROTO_IPV6;
955 else
956 return NF_ACCEPT;
957
958 if (skb->pkt_type == PACKET_OTHERHOST) {
959 skb->pkt_type = PACKET_HOST;
960 nf_bridge->pkt_otherhost = true;
961 }
962
963 nf_bridge_pull_encap_header(skb);
964 if (pf == NFPROTO_IPV4)
965 skb->protocol = htons(ETH_P_IP);
966 else
967 skb->protocol = htons(ETH_P_IPV6);
968
969 NF_HOOK(pf, NF_INET_POST_ROUTING, state->net, state->sk, skb,
970 NULL, realoutdev,
971 br_nf_dev_queue_xmit);
972
973 return NF_STOLEN;
974 }
975
976 /* IP/SABOTAGE *****************************************************/
977 /* Don't hand locally destined packets to PF_INET(6)/PRE_ROUTING
978 * for the second time. */
ip_sabotage_in(void * priv,struct sk_buff * skb,const struct nf_hook_state * state)979 static unsigned int ip_sabotage_in(void *priv,
980 struct sk_buff *skb,
981 const struct nf_hook_state *state)
982 {
983 struct nf_bridge_info *nf_bridge = nf_bridge_info_get(skb);
984
985 if (nf_bridge) {
986 if (nf_bridge->sabotage_in_done)
987 return NF_ACCEPT;
988
989 if (!nf_bridge->in_prerouting &&
990 !netif_is_l3_master(skb->dev) &&
991 !netif_is_l3_slave(skb->dev)) {
992 nf_bridge->sabotage_in_done = 1;
993 state->okfn(state->net, state->sk, skb);
994 return NF_STOLEN;
995 }
996 }
997
998 return NF_ACCEPT;
999 }
1000
1001 /* This is called when br_netfilter has called into iptables/netfilter,
1002 * and DNAT has taken place on a bridge-forwarded packet.
1003 *
1004 * neigh->output has created a new MAC header, with local br0 MAC
1005 * as saddr.
1006 *
1007 * This restores the original MAC saddr of the bridged packet
1008 * before invoking bridge forward logic to transmit the packet.
1009 */
br_nf_pre_routing_finish_bridge_slow(struct sk_buff * skb)1010 static void br_nf_pre_routing_finish_bridge_slow(struct sk_buff *skb)
1011 {
1012 struct nf_bridge_info *nf_bridge = nf_bridge_info_get(skb);
1013 struct net_device *br_indev;
1014
1015 br_indev = nf_bridge_get_physindev(skb, dev_net(skb->dev));
1016 if (!br_indev) {
1017 kfree_skb(skb);
1018 return;
1019 }
1020
1021 skb_pull(skb, ETH_HLEN);
1022 nf_bridge->bridged_dnat = 0;
1023
1024 BUILD_BUG_ON(sizeof(nf_bridge->neigh_header) != (ETH_HLEN - ETH_ALEN));
1025
1026 skb_copy_to_linear_data_offset(skb, -(ETH_HLEN - ETH_ALEN),
1027 nf_bridge->neigh_header,
1028 ETH_HLEN - ETH_ALEN);
1029 skb->dev = br_indev;
1030
1031 nf_bridge->physoutdev = NULL;
1032 br_handle_frame_finish(dev_net(skb->dev), NULL, skb);
1033 }
1034
br_nf_dev_xmit(struct sk_buff * skb)1035 static int br_nf_dev_xmit(struct sk_buff *skb)
1036 {
1037 const struct nf_bridge_info *nf_bridge = nf_bridge_info_get(skb);
1038
1039 if (nf_bridge && nf_bridge->bridged_dnat) {
1040 br_nf_pre_routing_finish_bridge_slow(skb);
1041 return 1;
1042 }
1043 return 0;
1044 }
1045
1046 static const struct nf_br_ops br_ops = {
1047 .br_dev_xmit_hook = br_nf_dev_xmit,
1048 };
1049
1050 /* For br_nf_post_routing, we need (prio = NF_BR_PRI_LAST), because
1051 * br_dev_queue_push_xmit is called afterwards */
1052 static const struct nf_hook_ops br_nf_ops[] = {
1053 {
1054 .hook = br_nf_pre_routing,
1055 .pf = NFPROTO_BRIDGE,
1056 .hooknum = NF_BR_PRE_ROUTING,
1057 .priority = NF_BR_PRI_BRNF,
1058 },
1059 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
1060 {
1061 .hook = br_nf_local_in,
1062 .pf = NFPROTO_BRIDGE,
1063 .hooknum = NF_BR_LOCAL_IN,
1064 .priority = NF_BR_PRI_LAST,
1065 },
1066 #endif
1067 {
1068 .hook = br_nf_forward_ip,
1069 .pf = NFPROTO_BRIDGE,
1070 .hooknum = NF_BR_FORWARD,
1071 .priority = NF_BR_PRI_BRNF - 1,
1072 },
1073 {
1074 .hook = br_nf_forward_arp,
1075 .pf = NFPROTO_BRIDGE,
1076 .hooknum = NF_BR_FORWARD,
1077 .priority = NF_BR_PRI_BRNF,
1078 },
1079 {
1080 .hook = br_nf_post_routing,
1081 .pf = NFPROTO_BRIDGE,
1082 .hooknum = NF_BR_POST_ROUTING,
1083 .priority = NF_BR_PRI_LAST,
1084 },
1085 {
1086 .hook = ip_sabotage_in,
1087 .pf = NFPROTO_IPV4,
1088 .hooknum = NF_INET_PRE_ROUTING,
1089 .priority = NF_IP_PRI_FIRST,
1090 },
1091 {
1092 .hook = ip_sabotage_in,
1093 .pf = NFPROTO_IPV6,
1094 .hooknum = NF_INET_PRE_ROUTING,
1095 .priority = NF_IP6_PRI_FIRST,
1096 },
1097 };
1098
brnf_device_event(struct notifier_block * unused,unsigned long event,void * ptr)1099 static int brnf_device_event(struct notifier_block *unused, unsigned long event,
1100 void *ptr)
1101 {
1102 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1103 struct brnf_net *brnet;
1104 struct net *net;
1105 int ret;
1106
1107 if (event != NETDEV_REGISTER || !netif_is_bridge_master(dev))
1108 return NOTIFY_DONE;
1109
1110 ASSERT_RTNL();
1111
1112 net = dev_net(dev);
1113 brnet = net_generic(net, brnf_net_id);
1114 if (brnet->enabled)
1115 return NOTIFY_OK;
1116
1117 ret = nf_register_net_hooks(net, br_nf_ops, ARRAY_SIZE(br_nf_ops));
1118 if (ret)
1119 return NOTIFY_BAD;
1120
1121 brnet->enabled = true;
1122 return NOTIFY_OK;
1123 }
1124
1125 static struct notifier_block brnf_notifier __read_mostly = {
1126 .notifier_call = brnf_device_event,
1127 };
1128
1129 /* recursively invokes nf_hook_slow (again), skipping already-called
1130 * hooks (< NF_BR_PRI_BRNF).
1131 *
1132 * Called with rcu read lock held.
1133 */
br_nf_hook_thresh(unsigned int hook,struct net * net,struct sock * sk,struct sk_buff * skb,struct net_device * indev,struct net_device * outdev,int (* okfn)(struct net *,struct sock *,struct sk_buff *))1134 int br_nf_hook_thresh(unsigned int hook, struct net *net,
1135 struct sock *sk, struct sk_buff *skb,
1136 struct net_device *indev,
1137 struct net_device *outdev,
1138 int (*okfn)(struct net *, struct sock *,
1139 struct sk_buff *))
1140 {
1141 const struct nf_hook_entries *e;
1142 struct nf_hook_state state;
1143 struct nf_hook_ops **ops;
1144 unsigned int i;
1145 int ret;
1146
1147 e = rcu_dereference(net->nf.hooks_bridge[hook]);
1148 if (!e)
1149 return okfn(net, sk, skb);
1150
1151 ops = nf_hook_entries_get_hook_ops(e);
1152 for (i = 0; i < e->num_hook_entries; i++) {
1153 /* These hooks have already been called */
1154 if (ops[i]->priority < NF_BR_PRI_BRNF)
1155 continue;
1156
1157 /* These hooks have not been called yet, run them. */
1158 if (ops[i]->priority > NF_BR_PRI_BRNF)
1159 break;
1160
1161 /* take a closer look at NF_BR_PRI_BRNF. */
1162 if (ops[i]->hook == br_nf_pre_routing) {
1163 /* This hook diverted the skb to this function,
1164 * hooks after this have not been run yet.
1165 */
1166 i++;
1167 break;
1168 }
1169 }
1170
1171 nf_hook_state_init(&state, hook, NFPROTO_BRIDGE, indev, outdev,
1172 sk, net, okfn);
1173
1174 ret = nf_hook_slow(skb, &state, e, i);
1175 if (ret == 1)
1176 ret = okfn(net, sk, skb);
1177
1178 return ret;
1179 }
1180
1181 #ifdef CONFIG_SYSCTL
1182 static
brnf_sysctl_call_tables(struct ctl_table * ctl,int write,void * buffer,size_t * lenp,loff_t * ppos)1183 int brnf_sysctl_call_tables(struct ctl_table *ctl, int write,
1184 void *buffer, size_t *lenp, loff_t *ppos)
1185 {
1186 int ret;
1187
1188 ret = proc_dointvec(ctl, write, buffer, lenp, ppos);
1189
1190 if (write && *(int *)(ctl->data))
1191 *(int *)(ctl->data) = 1;
1192 return ret;
1193 }
1194
1195 static struct ctl_table brnf_table[] = {
1196 {
1197 .procname = "bridge-nf-call-arptables",
1198 .maxlen = sizeof(int),
1199 .mode = 0644,
1200 .proc_handler = brnf_sysctl_call_tables,
1201 },
1202 {
1203 .procname = "bridge-nf-call-iptables",
1204 .maxlen = sizeof(int),
1205 .mode = 0644,
1206 .proc_handler = brnf_sysctl_call_tables,
1207 },
1208 {
1209 .procname = "bridge-nf-call-ip6tables",
1210 .maxlen = sizeof(int),
1211 .mode = 0644,
1212 .proc_handler = brnf_sysctl_call_tables,
1213 },
1214 {
1215 .procname = "bridge-nf-filter-vlan-tagged",
1216 .maxlen = sizeof(int),
1217 .mode = 0644,
1218 .proc_handler = brnf_sysctl_call_tables,
1219 },
1220 {
1221 .procname = "bridge-nf-filter-pppoe-tagged",
1222 .maxlen = sizeof(int),
1223 .mode = 0644,
1224 .proc_handler = brnf_sysctl_call_tables,
1225 },
1226 {
1227 .procname = "bridge-nf-pass-vlan-input-dev",
1228 .maxlen = sizeof(int),
1229 .mode = 0644,
1230 .proc_handler = brnf_sysctl_call_tables,
1231 },
1232 { }
1233 };
1234
br_netfilter_sysctl_default(struct brnf_net * brnf)1235 static inline void br_netfilter_sysctl_default(struct brnf_net *brnf)
1236 {
1237 brnf->call_iptables = 1;
1238 brnf->call_ip6tables = 1;
1239 brnf->call_arptables = 1;
1240 brnf->filter_vlan_tagged = 0;
1241 brnf->filter_pppoe_tagged = 0;
1242 brnf->pass_vlan_indev = 0;
1243 }
1244
br_netfilter_sysctl_init_net(struct net * net)1245 static int br_netfilter_sysctl_init_net(struct net *net)
1246 {
1247 struct ctl_table *table = brnf_table;
1248 struct brnf_net *brnet;
1249
1250 if (!net_eq(net, &init_net)) {
1251 table = kmemdup(table, sizeof(brnf_table), GFP_KERNEL);
1252 if (!table)
1253 return -ENOMEM;
1254 }
1255
1256 brnet = net_generic(net, brnf_net_id);
1257 table[0].data = &brnet->call_arptables;
1258 table[1].data = &brnet->call_iptables;
1259 table[2].data = &brnet->call_ip6tables;
1260 table[3].data = &brnet->filter_vlan_tagged;
1261 table[4].data = &brnet->filter_pppoe_tagged;
1262 table[5].data = &brnet->pass_vlan_indev;
1263
1264 br_netfilter_sysctl_default(brnet);
1265
1266 brnet->ctl_hdr = register_net_sysctl_sz(net, "net/bridge", table,
1267 ARRAY_SIZE(brnf_table));
1268 if (!brnet->ctl_hdr) {
1269 if (!net_eq(net, &init_net))
1270 kfree(table);
1271
1272 return -ENOMEM;
1273 }
1274
1275 return 0;
1276 }
1277
br_netfilter_sysctl_exit_net(struct net * net,struct brnf_net * brnet)1278 static void br_netfilter_sysctl_exit_net(struct net *net,
1279 struct brnf_net *brnet)
1280 {
1281 struct ctl_table *table = brnet->ctl_hdr->ctl_table_arg;
1282
1283 unregister_net_sysctl_table(brnet->ctl_hdr);
1284 if (!net_eq(net, &init_net))
1285 kfree(table);
1286 }
1287
brnf_init_net(struct net * net)1288 static int __net_init brnf_init_net(struct net *net)
1289 {
1290 return br_netfilter_sysctl_init_net(net);
1291 }
1292 #endif
1293
brnf_exit_net(struct net * net)1294 static void __net_exit brnf_exit_net(struct net *net)
1295 {
1296 struct brnf_net *brnet;
1297
1298 brnet = net_generic(net, brnf_net_id);
1299 if (brnet->enabled) {
1300 nf_unregister_net_hooks(net, br_nf_ops, ARRAY_SIZE(br_nf_ops));
1301 brnet->enabled = false;
1302 }
1303
1304 #ifdef CONFIG_SYSCTL
1305 br_netfilter_sysctl_exit_net(net, brnet);
1306 #endif
1307 }
1308
1309 static struct pernet_operations brnf_net_ops __read_mostly = {
1310 #ifdef CONFIG_SYSCTL
1311 .init = brnf_init_net,
1312 #endif
1313 .exit = brnf_exit_net,
1314 .id = &brnf_net_id,
1315 .size = sizeof(struct brnf_net),
1316 };
1317
br_netfilter_init(void)1318 static int __init br_netfilter_init(void)
1319 {
1320 int ret;
1321
1322 ret = register_pernet_subsys(&brnf_net_ops);
1323 if (ret < 0)
1324 return ret;
1325
1326 ret = register_netdevice_notifier(&brnf_notifier);
1327 if (ret < 0) {
1328 unregister_pernet_subsys(&brnf_net_ops);
1329 return ret;
1330 }
1331
1332 RCU_INIT_POINTER(nf_br_ops, &br_ops);
1333 printk(KERN_NOTICE "Bridge firewalling registered\n");
1334 return 0;
1335 }
1336
br_netfilter_fini(void)1337 static void __exit br_netfilter_fini(void)
1338 {
1339 RCU_INIT_POINTER(nf_br_ops, NULL);
1340 unregister_netdevice_notifier(&brnf_notifier);
1341 unregister_pernet_subsys(&brnf_net_ops);
1342 }
1343
1344 module_init(br_netfilter_init);
1345 module_exit(br_netfilter_fini);
1346
1347 MODULE_LICENSE("GPL");
1348 MODULE_AUTHOR("Lennert Buytenhek <buytenh@gnu.org>");
1349 MODULE_AUTHOR("Bart De Schuymer <bdschuym@pandora.be>");
1350 MODULE_DESCRIPTION("Linux ethernet netfilter firewall bridge");
1351