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 if (WARN_ON_ONCE(refcount_read(&nfct->use) != 1)) {
622 nf_reset_ct(skb);
623 return NF_ACCEPT;
624 }
625
626 WARN_ON_ONCE(skb_shared(skb));
627
628 /* We can't call nf_confirm here, it would create a dependency
629 * on nf_conntrack module.
630 */
631 ct_hook = rcu_dereference(nf_ct_hook);
632 if (!ct_hook) {
633 skb->_nfct = 0ul;
634 nf_conntrack_put(nfct);
635 return NF_ACCEPT;
636 }
637
638 nf_bridge_pull_encap_header(skb);
639 ret = ct_hook->confirm(skb);
640 switch (ret & NF_VERDICT_MASK) {
641 case NF_STOLEN:
642 return NF_STOLEN;
643 default:
644 nf_bridge_push_encap_header(skb);
645 break;
646 }
647
648 ct = container_of(nfct, struct nf_conn, ct_general);
649 WARN_ON_ONCE(!nf_ct_is_confirmed(ct));
650
651 return ret;
652 }
653 #endif
654
655 /* PF_BRIDGE/FORWARD *************************************************/
br_nf_forward_finish(struct net * net,struct sock * sk,struct sk_buff * skb)656 static int br_nf_forward_finish(struct net *net, struct sock *sk, struct sk_buff *skb)
657 {
658 struct nf_bridge_info *nf_bridge = nf_bridge_info_get(skb);
659 struct net_device *in;
660
661 if (!IS_ARP(skb) && !is_vlan_arp(skb, net)) {
662
663 if (skb->protocol == htons(ETH_P_IP))
664 nf_bridge->frag_max_size = IPCB(skb)->frag_max_size;
665
666 if (skb->protocol == htons(ETH_P_IPV6))
667 nf_bridge->frag_max_size = IP6CB(skb)->frag_max_size;
668
669 in = nf_bridge_get_physindev(skb, net);
670 if (!in) {
671 kfree_skb(skb);
672 return 0;
673 }
674 if (nf_bridge->pkt_otherhost) {
675 skb->pkt_type = PACKET_OTHERHOST;
676 nf_bridge->pkt_otherhost = false;
677 }
678 nf_bridge_update_protocol(skb);
679 } else {
680 in = *((struct net_device **)(skb->cb));
681 }
682 nf_bridge_push_encap_header(skb);
683
684 br_nf_hook_thresh(NF_BR_FORWARD, net, sk, skb, in, skb->dev,
685 br_forward_finish);
686 return 0;
687 }
688
689
690 /* This is the 'purely bridged' case. For IP, we pass the packet to
691 * netfilter with indev and outdev set to the bridge device,
692 * but we are still able to filter on the 'real' indev/outdev
693 * because of the physdev module. For ARP, indev and outdev are the
694 * bridge ports. */
br_nf_forward_ip(void * priv,struct sk_buff * skb,const struct nf_hook_state * state)695 static unsigned int br_nf_forward_ip(void *priv,
696 struct sk_buff *skb,
697 const struct nf_hook_state *state)
698 {
699 struct nf_bridge_info *nf_bridge;
700 struct net_device *parent;
701 u_int8_t pf;
702
703 nf_bridge = nf_bridge_info_get(skb);
704 if (!nf_bridge)
705 return NF_ACCEPT;
706
707 /* Need exclusive nf_bridge_info since we might have multiple
708 * different physoutdevs. */
709 if (!nf_bridge_unshare(skb))
710 return NF_DROP;
711
712 nf_bridge = nf_bridge_info_get(skb);
713 if (!nf_bridge)
714 return NF_DROP;
715
716 parent = bridge_parent(state->out);
717 if (!parent)
718 return NF_DROP;
719
720 if (IS_IP(skb) || is_vlan_ip(skb, state->net) ||
721 is_pppoe_ip(skb, state->net))
722 pf = NFPROTO_IPV4;
723 else if (IS_IPV6(skb) || is_vlan_ipv6(skb, state->net) ||
724 is_pppoe_ipv6(skb, state->net))
725 pf = NFPROTO_IPV6;
726 else
727 return NF_ACCEPT;
728
729 nf_bridge_pull_encap_header(skb);
730
731 if (skb->pkt_type == PACKET_OTHERHOST) {
732 skb->pkt_type = PACKET_HOST;
733 nf_bridge->pkt_otherhost = true;
734 }
735
736 if (pf == NFPROTO_IPV4) {
737 if (br_validate_ipv4(state->net, skb))
738 return NF_DROP;
739 IPCB(skb)->frag_max_size = nf_bridge->frag_max_size;
740 }
741
742 if (pf == NFPROTO_IPV6) {
743 if (br_validate_ipv6(state->net, skb))
744 return NF_DROP;
745 IP6CB(skb)->frag_max_size = nf_bridge->frag_max_size;
746 }
747
748 nf_bridge->physoutdev = skb->dev;
749 if (pf == NFPROTO_IPV4)
750 skb->protocol = htons(ETH_P_IP);
751 else
752 skb->protocol = htons(ETH_P_IPV6);
753
754 NF_HOOK(pf, NF_INET_FORWARD, state->net, NULL, skb,
755 brnf_get_logical_dev(skb, state->in, state->net),
756 parent, br_nf_forward_finish);
757
758 return NF_STOLEN;
759 }
760
br_nf_forward_arp(void * priv,struct sk_buff * skb,const struct nf_hook_state * state)761 static unsigned int br_nf_forward_arp(void *priv,
762 struct sk_buff *skb,
763 const struct nf_hook_state *state)
764 {
765 struct net_bridge_port *p;
766 struct net_bridge *br;
767 struct net_device **d = (struct net_device **)(skb->cb);
768 struct brnf_net *brnet;
769
770 p = br_port_get_rcu(state->out);
771 if (p == NULL)
772 return NF_ACCEPT;
773 br = p->br;
774
775 brnet = net_generic(state->net, brnf_net_id);
776 if (!brnet->call_arptables && !br_opt_get(br, BROPT_NF_CALL_ARPTABLES))
777 return NF_ACCEPT;
778
779 if (!IS_ARP(skb)) {
780 if (!is_vlan_arp(skb, state->net))
781 return NF_ACCEPT;
782 nf_bridge_pull_encap_header(skb);
783 }
784
785 if (unlikely(!pskb_may_pull(skb, sizeof(struct arphdr))))
786 return NF_DROP;
787
788 if (arp_hdr(skb)->ar_pln != 4) {
789 if (is_vlan_arp(skb, state->net))
790 nf_bridge_push_encap_header(skb);
791 return NF_ACCEPT;
792 }
793 *d = state->in;
794 NF_HOOK(NFPROTO_ARP, NF_ARP_FORWARD, state->net, state->sk, skb,
795 state->in, state->out, br_nf_forward_finish);
796
797 return NF_STOLEN;
798 }
799
br_nf_push_frag_xmit(struct net * net,struct sock * sk,struct sk_buff * skb)800 static int br_nf_push_frag_xmit(struct net *net, struct sock *sk, struct sk_buff *skb)
801 {
802 struct brnf_frag_data *data;
803 int err;
804
805 data = this_cpu_ptr(&brnf_frag_data_storage);
806 err = skb_cow_head(skb, data->size);
807
808 if (err) {
809 kfree_skb(skb);
810 return 0;
811 }
812
813 if (data->vlan_proto)
814 __vlan_hwaccel_put_tag(skb, data->vlan_proto, data->vlan_tci);
815
816 skb_copy_to_linear_data_offset(skb, -data->size, data->mac, data->size);
817 __skb_push(skb, data->encap_size);
818
819 nf_bridge_info_free(skb);
820 return br_dev_queue_push_xmit(net, sk, skb);
821 }
822
823 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 *))824 br_nf_ip_fragment(struct net *net, struct sock *sk, struct sk_buff *skb,
825 int (*output)(struct net *, struct sock *, struct sk_buff *))
826 {
827 unsigned int mtu = ip_skb_dst_mtu(sk, skb);
828 struct iphdr *iph = ip_hdr(skb);
829
830 if (unlikely(((iph->frag_off & htons(IP_DF)) && !skb->ignore_df) ||
831 (IPCB(skb)->frag_max_size &&
832 IPCB(skb)->frag_max_size > mtu))) {
833 IP_INC_STATS(net, IPSTATS_MIB_FRAGFAILS);
834 kfree_skb(skb);
835 return -EMSGSIZE;
836 }
837
838 return ip_do_fragment(net, sk, skb, output);
839 }
840
nf_bridge_mtu_reduction(const struct sk_buff * skb)841 static unsigned int nf_bridge_mtu_reduction(const struct sk_buff *skb)
842 {
843 const struct nf_bridge_info *nf_bridge = nf_bridge_info_get(skb);
844
845 if (nf_bridge->orig_proto == BRNF_PROTO_PPPOE)
846 return PPPOE_SES_HLEN;
847 return 0;
848 }
849
br_nf_dev_queue_xmit(struct net * net,struct sock * sk,struct sk_buff * skb)850 static int br_nf_dev_queue_xmit(struct net *net, struct sock *sk, struct sk_buff *skb)
851 {
852 struct nf_bridge_info *nf_bridge = nf_bridge_info_get(skb);
853 unsigned int mtu, mtu_reserved;
854
855 mtu_reserved = nf_bridge_mtu_reduction(skb);
856 mtu = skb->dev->mtu;
857
858 if (nf_bridge->pkt_otherhost) {
859 skb->pkt_type = PACKET_OTHERHOST;
860 nf_bridge->pkt_otherhost = false;
861 }
862
863 if (nf_bridge->frag_max_size && nf_bridge->frag_max_size < mtu)
864 mtu = nf_bridge->frag_max_size;
865
866 nf_bridge_update_protocol(skb);
867 nf_bridge_push_encap_header(skb);
868
869 if (skb_is_gso(skb) || skb->len + mtu_reserved <= mtu) {
870 nf_bridge_info_free(skb);
871 return br_dev_queue_push_xmit(net, sk, skb);
872 }
873
874 /* This is wrong! We should preserve the original fragment
875 * boundaries by preserving frag_list rather than refragmenting.
876 */
877 if (IS_ENABLED(CONFIG_NF_DEFRAG_IPV4) &&
878 skb->protocol == htons(ETH_P_IP)) {
879 struct brnf_frag_data *data;
880
881 if (br_validate_ipv4(net, skb))
882 goto drop;
883
884 IPCB(skb)->frag_max_size = nf_bridge->frag_max_size;
885
886 data = this_cpu_ptr(&brnf_frag_data_storage);
887
888 if (skb_vlan_tag_present(skb)) {
889 data->vlan_tci = skb->vlan_tci;
890 data->vlan_proto = skb->vlan_proto;
891 } else {
892 data->vlan_proto = 0;
893 }
894
895 data->encap_size = nf_bridge_encap_header_len(skb);
896 data->size = ETH_HLEN + data->encap_size;
897
898 skb_copy_from_linear_data_offset(skb, -data->size, data->mac,
899 data->size);
900
901 return br_nf_ip_fragment(net, sk, skb, br_nf_push_frag_xmit);
902 }
903 if (IS_ENABLED(CONFIG_NF_DEFRAG_IPV6) &&
904 skb->protocol == htons(ETH_P_IPV6)) {
905 const struct nf_ipv6_ops *v6ops = nf_get_ipv6_ops();
906 struct brnf_frag_data *data;
907
908 if (br_validate_ipv6(net, skb))
909 goto drop;
910
911 IP6CB(skb)->frag_max_size = nf_bridge->frag_max_size;
912
913 data = this_cpu_ptr(&brnf_frag_data_storage);
914 data->encap_size = nf_bridge_encap_header_len(skb);
915 data->size = ETH_HLEN + data->encap_size;
916
917 skb_copy_from_linear_data_offset(skb, -data->size, data->mac,
918 data->size);
919
920 if (v6ops)
921 return v6ops->fragment(net, sk, skb, br_nf_push_frag_xmit);
922
923 kfree_skb(skb);
924 return -EMSGSIZE;
925 }
926 nf_bridge_info_free(skb);
927 return br_dev_queue_push_xmit(net, sk, skb);
928 drop:
929 kfree_skb(skb);
930 return 0;
931 }
932
933 /* PF_BRIDGE/POST_ROUTING ********************************************/
br_nf_post_routing(void * priv,struct sk_buff * skb,const struct nf_hook_state * state)934 static unsigned int br_nf_post_routing(void *priv,
935 struct sk_buff *skb,
936 const struct nf_hook_state *state)
937 {
938 struct nf_bridge_info *nf_bridge = nf_bridge_info_get(skb);
939 struct net_device *realoutdev = bridge_parent(skb->dev);
940 u_int8_t pf;
941
942 /* if nf_bridge is set, but ->physoutdev is NULL, this packet came in
943 * on a bridge, but was delivered locally and is now being routed:
944 *
945 * POST_ROUTING was already invoked from the ip stack.
946 */
947 if (!nf_bridge || !nf_bridge->physoutdev)
948 return NF_ACCEPT;
949
950 if (!realoutdev)
951 return NF_DROP;
952
953 if (IS_IP(skb) || is_vlan_ip(skb, state->net) ||
954 is_pppoe_ip(skb, state->net))
955 pf = NFPROTO_IPV4;
956 else if (IS_IPV6(skb) || is_vlan_ipv6(skb, state->net) ||
957 is_pppoe_ipv6(skb, state->net))
958 pf = NFPROTO_IPV6;
959 else
960 return NF_ACCEPT;
961
962 if (skb->pkt_type == PACKET_OTHERHOST) {
963 skb->pkt_type = PACKET_HOST;
964 nf_bridge->pkt_otherhost = true;
965 }
966
967 nf_bridge_pull_encap_header(skb);
968 if (pf == NFPROTO_IPV4)
969 skb->protocol = htons(ETH_P_IP);
970 else
971 skb->protocol = htons(ETH_P_IPV6);
972
973 NF_HOOK(pf, NF_INET_POST_ROUTING, state->net, state->sk, skb,
974 NULL, realoutdev,
975 br_nf_dev_queue_xmit);
976
977 return NF_STOLEN;
978 }
979
980 /* IP/SABOTAGE *****************************************************/
981 /* Don't hand locally destined packets to PF_INET(6)/PRE_ROUTING
982 * for the second time. */
ip_sabotage_in(void * priv,struct sk_buff * skb,const struct nf_hook_state * state)983 static unsigned int ip_sabotage_in(void *priv,
984 struct sk_buff *skb,
985 const struct nf_hook_state *state)
986 {
987 struct nf_bridge_info *nf_bridge = nf_bridge_info_get(skb);
988
989 if (nf_bridge) {
990 if (nf_bridge->sabotage_in_done)
991 return NF_ACCEPT;
992
993 if (!nf_bridge->in_prerouting &&
994 !netif_is_l3_master(skb->dev) &&
995 !netif_is_l3_slave(skb->dev)) {
996 nf_bridge->sabotage_in_done = 1;
997 state->okfn(state->net, state->sk, skb);
998 return NF_STOLEN;
999 }
1000 }
1001
1002 return NF_ACCEPT;
1003 }
1004
1005 /* This is called when br_netfilter has called into iptables/netfilter,
1006 * and DNAT has taken place on a bridge-forwarded packet.
1007 *
1008 * neigh->output has created a new MAC header, with local br0 MAC
1009 * as saddr.
1010 *
1011 * This restores the original MAC saddr of the bridged packet
1012 * before invoking bridge forward logic to transmit the packet.
1013 */
br_nf_pre_routing_finish_bridge_slow(struct sk_buff * skb)1014 static void br_nf_pre_routing_finish_bridge_slow(struct sk_buff *skb)
1015 {
1016 struct nf_bridge_info *nf_bridge = nf_bridge_info_get(skb);
1017 struct net_device *br_indev;
1018
1019 br_indev = nf_bridge_get_physindev(skb, dev_net(skb->dev));
1020 if (!br_indev) {
1021 kfree_skb(skb);
1022 return;
1023 }
1024
1025 skb_pull(skb, ETH_HLEN);
1026 nf_bridge->bridged_dnat = 0;
1027
1028 BUILD_BUG_ON(sizeof(nf_bridge->neigh_header) != (ETH_HLEN - ETH_ALEN));
1029
1030 skb_copy_to_linear_data_offset(skb, -(ETH_HLEN - ETH_ALEN),
1031 nf_bridge->neigh_header,
1032 ETH_HLEN - ETH_ALEN);
1033 skb->dev = br_indev;
1034
1035 nf_bridge->physoutdev = NULL;
1036 br_handle_frame_finish(dev_net(skb->dev), NULL, skb);
1037 }
1038
br_nf_dev_xmit(struct sk_buff * skb)1039 static int br_nf_dev_xmit(struct sk_buff *skb)
1040 {
1041 const struct nf_bridge_info *nf_bridge = nf_bridge_info_get(skb);
1042
1043 if (nf_bridge && nf_bridge->bridged_dnat) {
1044 br_nf_pre_routing_finish_bridge_slow(skb);
1045 return 1;
1046 }
1047 return 0;
1048 }
1049
1050 static const struct nf_br_ops br_ops = {
1051 .br_dev_xmit_hook = br_nf_dev_xmit,
1052 };
1053
1054 /* For br_nf_post_routing, we need (prio = NF_BR_PRI_LAST), because
1055 * br_dev_queue_push_xmit is called afterwards */
1056 static const struct nf_hook_ops br_nf_ops[] = {
1057 {
1058 .hook = br_nf_pre_routing,
1059 .pf = NFPROTO_BRIDGE,
1060 .hooknum = NF_BR_PRE_ROUTING,
1061 .priority = NF_BR_PRI_BRNF,
1062 },
1063 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
1064 {
1065 .hook = br_nf_local_in,
1066 .pf = NFPROTO_BRIDGE,
1067 .hooknum = NF_BR_LOCAL_IN,
1068 .priority = NF_BR_PRI_LAST,
1069 },
1070 #endif
1071 {
1072 .hook = br_nf_forward_ip,
1073 .pf = NFPROTO_BRIDGE,
1074 .hooknum = NF_BR_FORWARD,
1075 .priority = NF_BR_PRI_BRNF - 1,
1076 },
1077 {
1078 .hook = br_nf_forward_arp,
1079 .pf = NFPROTO_BRIDGE,
1080 .hooknum = NF_BR_FORWARD,
1081 .priority = NF_BR_PRI_BRNF,
1082 },
1083 {
1084 .hook = br_nf_post_routing,
1085 .pf = NFPROTO_BRIDGE,
1086 .hooknum = NF_BR_POST_ROUTING,
1087 .priority = NF_BR_PRI_LAST,
1088 },
1089 {
1090 .hook = ip_sabotage_in,
1091 .pf = NFPROTO_IPV4,
1092 .hooknum = NF_INET_PRE_ROUTING,
1093 .priority = NF_IP_PRI_FIRST,
1094 },
1095 {
1096 .hook = ip_sabotage_in,
1097 .pf = NFPROTO_IPV6,
1098 .hooknum = NF_INET_PRE_ROUTING,
1099 .priority = NF_IP6_PRI_FIRST,
1100 },
1101 };
1102
brnf_device_event(struct notifier_block * unused,unsigned long event,void * ptr)1103 static int brnf_device_event(struct notifier_block *unused, unsigned long event,
1104 void *ptr)
1105 {
1106 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1107 struct brnf_net *brnet;
1108 struct net *net;
1109 int ret;
1110
1111 if (event != NETDEV_REGISTER || !netif_is_bridge_master(dev))
1112 return NOTIFY_DONE;
1113
1114 ASSERT_RTNL();
1115
1116 net = dev_net(dev);
1117 brnet = net_generic(net, brnf_net_id);
1118 if (brnet->enabled)
1119 return NOTIFY_OK;
1120
1121 ret = nf_register_net_hooks(net, br_nf_ops, ARRAY_SIZE(br_nf_ops));
1122 if (ret)
1123 return NOTIFY_BAD;
1124
1125 brnet->enabled = true;
1126 return NOTIFY_OK;
1127 }
1128
1129 static struct notifier_block brnf_notifier __read_mostly = {
1130 .notifier_call = brnf_device_event,
1131 };
1132
1133 /* recursively invokes nf_hook_slow (again), skipping already-called
1134 * hooks (< NF_BR_PRI_BRNF).
1135 *
1136 * Called with rcu read lock held.
1137 */
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 *))1138 int br_nf_hook_thresh(unsigned int hook, struct net *net,
1139 struct sock *sk, struct sk_buff *skb,
1140 struct net_device *indev,
1141 struct net_device *outdev,
1142 int (*okfn)(struct net *, struct sock *,
1143 struct sk_buff *))
1144 {
1145 const struct nf_hook_entries *e;
1146 struct nf_hook_state state;
1147 struct nf_hook_ops **ops;
1148 unsigned int i;
1149 int ret;
1150
1151 e = rcu_dereference(net->nf.hooks_bridge[hook]);
1152 if (!e)
1153 return okfn(net, sk, skb);
1154
1155 ops = nf_hook_entries_get_hook_ops(e);
1156 for (i = 0; i < e->num_hook_entries; i++) {
1157 /* These hooks have already been called */
1158 if (ops[i]->priority < NF_BR_PRI_BRNF)
1159 continue;
1160
1161 /* These hooks have not been called yet, run them. */
1162 if (ops[i]->priority > NF_BR_PRI_BRNF)
1163 break;
1164
1165 /* take a closer look at NF_BR_PRI_BRNF. */
1166 if (ops[i]->hook == br_nf_pre_routing) {
1167 /* This hook diverted the skb to this function,
1168 * hooks after this have not been run yet.
1169 */
1170 i++;
1171 break;
1172 }
1173 }
1174
1175 nf_hook_state_init(&state, hook, NFPROTO_BRIDGE, indev, outdev,
1176 sk, net, okfn);
1177
1178 ret = nf_hook_slow(skb, &state, e, i);
1179 if (ret == 1)
1180 ret = okfn(net, sk, skb);
1181
1182 return ret;
1183 }
1184
1185 #ifdef CONFIG_SYSCTL
1186 static
brnf_sysctl_call_tables(struct ctl_table * ctl,int write,void * buffer,size_t * lenp,loff_t * ppos)1187 int brnf_sysctl_call_tables(struct ctl_table *ctl, int write,
1188 void *buffer, size_t *lenp, loff_t *ppos)
1189 {
1190 int ret;
1191
1192 ret = proc_dointvec(ctl, write, buffer, lenp, ppos);
1193
1194 if (write && *(int *)(ctl->data))
1195 *(int *)(ctl->data) = 1;
1196 return ret;
1197 }
1198
1199 static struct ctl_table brnf_table[] = {
1200 {
1201 .procname = "bridge-nf-call-arptables",
1202 .maxlen = sizeof(int),
1203 .mode = 0644,
1204 .proc_handler = brnf_sysctl_call_tables,
1205 },
1206 {
1207 .procname = "bridge-nf-call-iptables",
1208 .maxlen = sizeof(int),
1209 .mode = 0644,
1210 .proc_handler = brnf_sysctl_call_tables,
1211 },
1212 {
1213 .procname = "bridge-nf-call-ip6tables",
1214 .maxlen = sizeof(int),
1215 .mode = 0644,
1216 .proc_handler = brnf_sysctl_call_tables,
1217 },
1218 {
1219 .procname = "bridge-nf-filter-vlan-tagged",
1220 .maxlen = sizeof(int),
1221 .mode = 0644,
1222 .proc_handler = brnf_sysctl_call_tables,
1223 },
1224 {
1225 .procname = "bridge-nf-filter-pppoe-tagged",
1226 .maxlen = sizeof(int),
1227 .mode = 0644,
1228 .proc_handler = brnf_sysctl_call_tables,
1229 },
1230 {
1231 .procname = "bridge-nf-pass-vlan-input-dev",
1232 .maxlen = sizeof(int),
1233 .mode = 0644,
1234 .proc_handler = brnf_sysctl_call_tables,
1235 },
1236 { }
1237 };
1238
br_netfilter_sysctl_default(struct brnf_net * brnf)1239 static inline void br_netfilter_sysctl_default(struct brnf_net *brnf)
1240 {
1241 brnf->call_iptables = 1;
1242 brnf->call_ip6tables = 1;
1243 brnf->call_arptables = 1;
1244 brnf->filter_vlan_tagged = 0;
1245 brnf->filter_pppoe_tagged = 0;
1246 brnf->pass_vlan_indev = 0;
1247 }
1248
br_netfilter_sysctl_init_net(struct net * net)1249 static int br_netfilter_sysctl_init_net(struct net *net)
1250 {
1251 struct ctl_table *table = brnf_table;
1252 struct brnf_net *brnet;
1253
1254 if (!net_eq(net, &init_net)) {
1255 table = kmemdup(table, sizeof(brnf_table), GFP_KERNEL);
1256 if (!table)
1257 return -ENOMEM;
1258 }
1259
1260 brnet = net_generic(net, brnf_net_id);
1261 table[0].data = &brnet->call_arptables;
1262 table[1].data = &brnet->call_iptables;
1263 table[2].data = &brnet->call_ip6tables;
1264 table[3].data = &brnet->filter_vlan_tagged;
1265 table[4].data = &brnet->filter_pppoe_tagged;
1266 table[5].data = &brnet->pass_vlan_indev;
1267
1268 br_netfilter_sysctl_default(brnet);
1269
1270 brnet->ctl_hdr = register_net_sysctl_sz(net, "net/bridge", table,
1271 ARRAY_SIZE(brnf_table));
1272 if (!brnet->ctl_hdr) {
1273 if (!net_eq(net, &init_net))
1274 kfree(table);
1275
1276 return -ENOMEM;
1277 }
1278
1279 return 0;
1280 }
1281
br_netfilter_sysctl_exit_net(struct net * net,struct brnf_net * brnet)1282 static void br_netfilter_sysctl_exit_net(struct net *net,
1283 struct brnf_net *brnet)
1284 {
1285 struct ctl_table *table = brnet->ctl_hdr->ctl_table_arg;
1286
1287 unregister_net_sysctl_table(brnet->ctl_hdr);
1288 if (!net_eq(net, &init_net))
1289 kfree(table);
1290 }
1291
brnf_init_net(struct net * net)1292 static int __net_init brnf_init_net(struct net *net)
1293 {
1294 return br_netfilter_sysctl_init_net(net);
1295 }
1296 #endif
1297
brnf_exit_net(struct net * net)1298 static void __net_exit brnf_exit_net(struct net *net)
1299 {
1300 struct brnf_net *brnet;
1301
1302 brnet = net_generic(net, brnf_net_id);
1303 if (brnet->enabled) {
1304 nf_unregister_net_hooks(net, br_nf_ops, ARRAY_SIZE(br_nf_ops));
1305 brnet->enabled = false;
1306 }
1307
1308 #ifdef CONFIG_SYSCTL
1309 br_netfilter_sysctl_exit_net(net, brnet);
1310 #endif
1311 }
1312
1313 static struct pernet_operations brnf_net_ops __read_mostly = {
1314 #ifdef CONFIG_SYSCTL
1315 .init = brnf_init_net,
1316 #endif
1317 .exit = brnf_exit_net,
1318 .id = &brnf_net_id,
1319 .size = sizeof(struct brnf_net),
1320 };
1321
br_netfilter_init(void)1322 static int __init br_netfilter_init(void)
1323 {
1324 int ret;
1325
1326 ret = register_pernet_subsys(&brnf_net_ops);
1327 if (ret < 0)
1328 return ret;
1329
1330 ret = register_netdevice_notifier(&brnf_notifier);
1331 if (ret < 0) {
1332 unregister_pernet_subsys(&brnf_net_ops);
1333 return ret;
1334 }
1335
1336 RCU_INIT_POINTER(nf_br_ops, &br_ops);
1337 printk(KERN_NOTICE "Bridge firewalling registered\n");
1338 return 0;
1339 }
1340
br_netfilter_fini(void)1341 static void __exit br_netfilter_fini(void)
1342 {
1343 RCU_INIT_POINTER(nf_br_ops, NULL);
1344 unregister_netdevice_notifier(&brnf_notifier);
1345 unregister_pernet_subsys(&brnf_net_ops);
1346 }
1347
1348 module_init(br_netfilter_init);
1349 module_exit(br_netfilter_fini);
1350
1351 MODULE_LICENSE("GPL");
1352 MODULE_AUTHOR("Lennert Buytenhek <buytenh@gnu.org>");
1353 MODULE_AUTHOR("Bart De Schuymer <bdschuym@pandora.be>");
1354 MODULE_DESCRIPTION("Linux ethernet netfilter firewall bridge");
1355