net/bridge/br_netfilter.c

   1 /*
   2  *      Handle firewalling
   3  *      Linux ethernet bridge
   4  *
   5  *      Authors:
   6  *      Lennert Buytenhek               <buytenh@gnu.org>
   7  *      Bart De Schuymer                <bdschuym@pandora.be>
   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>
  19 #include <linux/slab.h>
  20 #include <linux/ip.h>
  21 #include <linux/netdevice.h>
  22 #include <linux/skbuff.h>
  23 #include <linux/if_arp.h>
  24 #include <linux/if_ether.h>
  25 #include <linux/if_vlan.h>
  26 #include <linux/if_pppox.h>
  27 #include <linux/ppp_defs.h>
  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>
  33 #include <linux/inetdevice.h>
  34
  35 #include <net/ip.h>
  36 #include <net/ipv6.h>
  37 #include <net/addrconf.h>
  38 #include <net/route.h>
  39 #include <net/netfilter/br_netfilter.h>
  40
  41 #include <asm/uaccess.h>
  42 #include "br_private.h"
  43 #ifdef CONFIG_SYSCTL
  44 #include <linux/sysctl.h>
  45 #endif
  46
  47 #ifdef CONFIG_SYSCTL
  48 static struct ctl_table_header *brnf_sysctl_header;
  49 static int brnf_call_iptables __read_mostly = 1;
  50 static int brnf_call_ip6tables __read_mostly = 1;
  51 static int brnf_call_arptables __read_mostly = 1;
  52 static int brnf_filter_vlan_tagged __read_mostly = 0;
  53 static int brnf_filter_pppoe_tagged __read_mostly = 0;
  54 static int brnf_pass_vlan_indev __read_mostly = 0;
  55 #else
  56 #define brnf_call_iptables 1
  57 #define brnf_call_ip6tables 1
  58 #define brnf_call_arptables 1
  59 #define brnf_filter_vlan_tagged 0
  60 #define brnf_filter_pppoe_tagged 0
  61 #define brnf_pass_vlan_indev 0
  62 #endif
  63
  64 #define IS_IP(skb) \
  65         (!skb_vlan_tag_present(skb) && skb->protocol == htons(ETH_P_IP))
  66
  67 #define IS_IPV6(skb) \
  68         (!skb_vlan_tag_present(skb) && skb->protocol == htons(ETH_P_IPV6))
  69
  70 #define IS_ARP(skb) \
  71         (!skb_vlan_tag_present(skb) && skb->protocol == htons(ETH_P_ARP))
  72
  73 static inline __be16 vlan_proto(const struct sk_buff *skb)
  74 {
  75         if (skb_vlan_tag_present(skb))
  76                 return skb->protocol;
  77         else if (skb->protocol == htons(ETH_P_8021Q))
  78                 return vlan_eth_hdr(skb)->h_vlan_encapsulated_proto;
  79         else
  80                 return 0;
  81 }
  82
  83 #define IS_VLAN_IP(skb) \
  84         (vlan_proto(skb) == htons(ETH_P_IP) && \
  85          brnf_filter_vlan_tagged)
  86
  87 #define IS_VLAN_IPV6(skb) \
  88         (vlan_proto(skb) == htons(ETH_P_IPV6) && \
  89          brnf_filter_vlan_tagged)
  90
  91 #define IS_VLAN_ARP(skb) \
  92         (vlan_proto(skb) == htons(ETH_P_ARP) && \
  93          brnf_filter_vlan_tagged)
  94
  95 static inline __be16 pppoe_proto(const struct sk_buff *skb)
  96 {
  97         return *((__be16 *)(skb_mac_header(skb) + ETH_HLEN +
  98                             sizeof(struct pppoe_hdr)));
  99 }
 100
 101 #define IS_PPPOE_IP(skb) \
 102         (skb->protocol == htons(ETH_P_PPP_SES) && \
 103          pppoe_proto(skb) == htons(PPP_IP) && \
 104          brnf_filter_pppoe_tagged)
 105
 106 #define IS_PPPOE_IPV6(skb) \
 107         (skb->protocol == htons(ETH_P_PPP_SES) && \
 108          pppoe_proto(skb) == htons(PPP_IPV6) && \
 109          brnf_filter_pppoe_tagged)
 110
 111 /* largest possible L2 header, see br_nf_dev_queue_xmit() */
 112 #define NF_BRIDGE_MAX_MAC_HEADER_LENGTH (PPPOE_SES_HLEN + ETH_HLEN)
 113
 114 #if IS_ENABLED(CONFIG_NF_DEFRAG_IPV4)
 115 struct brnf_frag_data {
 116         char mac[NF_BRIDGE_MAX_MAC_HEADER_LENGTH];
 117         u8 encap_size;
 118         u8 size;
 119 };
 120
 121 static DEFINE_PER_CPU(struct brnf_frag_data, brnf_frag_data_storage);
 122 #endif
 123
 124 static struct nf_bridge_info *nf_bridge_info_get(const struct sk_buff *skb)
 125 {
 126         return skb->nf_bridge;
 127 }
 128
 129 static void nf_bridge_info_free(struct sk_buff *skb)
 130 {
 131         if (skb->nf_bridge) {
 132                 nf_bridge_put(skb->nf_bridge);
 133                 skb->nf_bridge = NULL;
 134         }
 135 }
 136
 137 static inline struct rtable *bridge_parent_rtable(const struct net_device *dev)
 138 {
 139         struct net_bridge_port *port;
 140
 141         port = br_port_get_rcu(dev);
 142         return port ? &port->br->fake_rtable : NULL;
 143 }
 144
 145 static inline struct net_device *bridge_parent(const struct net_device *dev)
 146 {
 147         struct net_bridge_port *port;
 148
 149         port = br_port_get_rcu(dev);
 150         return port ? port->br->dev : NULL;
 151 }
 152
 153 static inline struct nf_bridge_info *nf_bridge_alloc(struct sk_buff *skb)
 154 {
 155         skb->nf_bridge = kzalloc(sizeof(struct nf_bridge_info), GFP_ATOMIC);
 156         if (likely(skb->nf_bridge))
 157                 atomic_set(&(skb->nf_bridge->use), 1);
 158
 159         return skb->nf_bridge;
 160 }
 161
 162 static inline struct nf_bridge_info *nf_bridge_unshare(struct sk_buff *skb)
 163 {
 164         struct nf_bridge_info *nf_bridge = skb->nf_bridge;
 165
 166         if (atomic_read(&nf_bridge->use) > 1) {
 167                 struct nf_bridge_info *tmp = nf_bridge_alloc(skb);
 168
 169                 if (tmp) {
 170                         memcpy(tmp, nf_bridge, sizeof(struct nf_bridge_info));
 171                         atomic_set(&tmp->use, 1);
 172                 }
 173                 nf_bridge_put(nf_bridge);
 174                 nf_bridge = tmp;
 175         }
 176         return nf_bridge;
 177 }
 178
 179 static unsigned int nf_bridge_encap_header_len(const struct sk_buff *skb)
 180 {
 181         switch (skb->protocol) {
 182         case __cpu_to_be16(ETH_P_8021Q):
 183                 return VLAN_HLEN;
 184         case __cpu_to_be16(ETH_P_PPP_SES):
 185                 return PPPOE_SES_HLEN;
 186         default:
 187                 return 0;
 188         }
 189 }
 190
 191 static inline void nf_bridge_push_encap_header(struct sk_buff *skb)
 192 {
 193         unsigned int len = nf_bridge_encap_header_len(skb);
 194
 195         skb_push(skb, len);
 196         skb->network_header -= len;
 197 }
 198
 199 static inline void nf_bridge_pull_encap_header(struct sk_buff *skb)
 200 {
 201         unsigned int len = nf_bridge_encap_header_len(skb);
 202
 203         skb_pull(skb, len);
 204         skb->network_header += len;
 205 }
 206
 207 static inline void nf_bridge_pull_encap_header_rcsum(struct sk_buff *skb)
 208 {
 209         unsigned int len = nf_bridge_encap_header_len(skb);
 210
 211         skb_pull_rcsum(skb, len);
 212         skb->network_header += len;
 213 }
 214
 215 /* When handing a packet over to the IP layer
 216  * check whether we have a skb that is in the
 217  * expected format
 218  */
 219
 220 static int br_validate_ipv4(struct sk_buff *skb)
 221 {
 222         const struct iphdr *iph;
 223         struct net_device *dev = skb->dev;
 224         u32 len;
 225
 226         if (!pskb_may_pull(skb, sizeof(struct iphdr)))
 227                 goto inhdr_error;
 228
 229         iph = ip_hdr(skb);
 230
 231         /* Basic sanity checks */
 232         if (iph->ihl < 5 || iph->version != 4)
 233                 goto inhdr_error;
 234
 235         if (!pskb_may_pull(skb, iph->ihl*4))
 236                 goto inhdr_error;
 237
 238         iph = ip_hdr(skb);
 239         if (unlikely(ip_fast_csum((u8 *)iph, iph->ihl)))
 240                 goto inhdr_error;
 241
 242         len = ntohs(iph->tot_len);
 243         if (skb->len < len) {
 244                 IP_INC_STATS_BH(dev_net(dev), IPSTATS_MIB_INTRUNCATEDPKTS);
 245                 goto drop;
 246         } else if (len < (iph->ihl*4))
 247                 goto inhdr_error;
 248
 249         if (pskb_trim_rcsum(skb, len)) {
 250                 IP_INC_STATS_BH(dev_net(dev), IPSTATS_MIB_INDISCARDS);
 251                 goto drop;
 252         }
 253
 254         memset(IPCB(skb), 0, sizeof(struct inet_skb_parm));
 255         /* We should really parse IP options here but until
 256          * somebody who actually uses IP options complains to
 257          * us we'll just silently ignore the options because
 258          * we're lazy!
 259          */
 260         return 0;
 261
 262 inhdr_error:
 263         IP_INC_STATS_BH(dev_net(dev), IPSTATS_MIB_INHDRERRORS);
 264 drop:
 265         return -1;
 266 }
 267
 268 /* We only check the length. A bridge shouldn't do any hop-by-hop stuff
 269  * anyway
 270  */
 271 static int check_hbh_len(struct sk_buff *skb)
 272 {
 273         unsigned char *raw = (u8 *)(ipv6_hdr(skb) + 1);
 274         u32 pkt_len;
 275         const unsigned char *nh = skb_network_header(skb);
 276         int off = raw - nh;
 277         int len = (raw[1] + 1) << 3;
 278
 279         if ((raw + len) - skb->data > skb_headlen(skb))
 280                 goto bad;
 281
 282         off += 2;
 283         len -= 2;
 284
 285         while (len > 0) {
 286                 int optlen = nh[off + 1] + 2;
 287
 288                 switch (nh[off]) {
 289                 case IPV6_TLV_PAD1:
 290                         optlen = 1;
 291                         break;
 292
 293                 case IPV6_TLV_PADN:
 294                         break;
 295
 296                 case IPV6_TLV_JUMBO:
 297                         if (nh[off + 1] != 4 || (off & 3) != 2)
 298                                 goto bad;
 299                         pkt_len = ntohl(*(__be32 *)(nh + off + 2));
 300                         if (pkt_len <= IPV6_MAXPLEN ||
 301                             ipv6_hdr(skb)->payload_len)
 302                                 goto bad;
 303                         if (pkt_len > skb->len - sizeof(struct ipv6hdr))
 304                                 goto bad;
 305                         if (pskb_trim_rcsum(skb,
 306                                             pkt_len + sizeof(struct ipv6hdr)))
 307                                 goto bad;
 308                         nh = skb_network_header(skb);
 309                         break;
 310                 default:
 311                         if (optlen > len)
 312                                 goto bad;
 313                         break;
 314                 }
 315                 off += optlen;
 316                 len -= optlen;
 317         }
 318         if (len == 0)
 319                 return 0;
 320 bad:
 321         return -1;
 322 }
 323
 324 /* Equivalent to br_validate_ipv4 for IPv6 */
 325 static int br_validate_ipv6(struct sk_buff *skb)
 326 {
 327         const struct ipv6hdr *hdr;
 328         struct net_device *dev = skb->dev;
 329         struct inet6_dev *idev = in6_dev_get(skb->dev);
 330         u32 pkt_len;
 331         u8 ip6h_len = sizeof(struct ipv6hdr);
 332
 333         if (!pskb_may_pull(skb, ip6h_len))
 334                 goto inhdr_error;
 335
 336         if (skb->len < ip6h_len)
 337                 goto drop;
 338
 339         hdr = ipv6_hdr(skb);
 340
 341         if (hdr->version != 6)
 342                 goto inhdr_error;
 343
 344         pkt_len = ntohs(hdr->payload_len);
 345
 346         if (pkt_len || hdr->nexthdr != NEXTHDR_HOP) {
 347                 if (pkt_len + ip6h_len > skb->len) {
 348                         IP6_INC_STATS_BH(dev_net(dev), idev,
 349                                          IPSTATS_MIB_INTRUNCATEDPKTS);
 350                         goto drop;
 351                 }
 352                 if (pskb_trim_rcsum(skb, pkt_len + ip6h_len)) {
 353                         IP6_INC_STATS_BH(dev_net(dev), idev,
 354                                          IPSTATS_MIB_INDISCARDS);
 355                         goto drop;
 356                 }
 357         }
 358         if (hdr->nexthdr == NEXTHDR_HOP && check_hbh_len(skb))
 359                 goto drop;
 360
 361         memset(IP6CB(skb), 0, sizeof(struct inet6_skb_parm));
 362         /* No IP options in IPv6 header; however it should be
 363          * checked if some next headers need special treatment
 364          */
 365         return 0;
 366
 367 inhdr_error:
 368         IP6_INC_STATS_BH(dev_net(dev), idev, IPSTATS_MIB_INHDRERRORS);
 369 drop:
 370         return -1;
 371 }
 372
 373 static void nf_bridge_update_protocol(struct sk_buff *skb)
 374 {
 375         switch (skb->nf_bridge->orig_proto) {
 376         case BRNF_PROTO_8021Q:
 377                 skb->protocol = htons(ETH_P_8021Q);
 378                 break;
 379         case BRNF_PROTO_PPPOE:
 380                 skb->protocol = htons(ETH_P_PPP_SES);
 381                 break;
 382         case BRNF_PROTO_UNCHANGED:
 383                 break;
 384         }
 385 }
 386
 387 /* Obtain the correct destination MAC address, while preserving the original
 388  * source MAC address. If we already know this address, we just copy it. If we
 389  * don't, we use the neighbour framework to find out. In both cases, we make
 390  * sure that br_handle_frame_finish() is called afterwards.
 391  */
 392 static int br_nf_pre_routing_finish_bridge(struct sock *sk, struct sk_buff *skb)
 393 {
 394         struct neighbour *neigh;
 395         struct dst_entry *dst;
 396
 397         skb->dev = bridge_parent(skb->dev);
 398         if (!skb->dev)
 399                 goto free_skb;
 400         dst = skb_dst(skb);
 401         neigh = dst_neigh_lookup_skb(dst, skb);
 402         if (neigh) {
 403                 struct nf_bridge_info *nf_bridge = nf_bridge_info_get(skb);
 404                 int ret;
 405
 406                 if (neigh->hh.hh_len) {
 407                         neigh_hh_bridge(&neigh->hh, skb);
 408                         skb->dev = nf_bridge->physindev;
 409                         ret = br_handle_frame_finish(sk, skb);
 410                 } else {
 411                         /* the neighbour function below overwrites the complete
 412                          * MAC header, so we save the Ethernet source address and
 413                          * protocol number.
 414                          */
 415                         skb_copy_from_linear_data_offset(skb,
 416                                                          -(ETH_HLEN-ETH_ALEN),
 417                                                          nf_bridge->neigh_header,
 418                                                          ETH_HLEN-ETH_ALEN);
 419                         /* tell br_dev_xmit to continue with forwarding */
 420                         nf_bridge->mask |= BRNF_BRIDGED_DNAT;
 421                         /* FIXME Need to refragment */
 422                         ret = neigh->output(neigh, skb);
 423                 }
 424                 neigh_release(neigh);
 425                 return ret;
 426         }
 427 free_skb:
 428         kfree_skb(skb);
 429         return 0;
 430 }
 431
 432 static bool daddr_was_changed(const struct sk_buff *skb,
 433                               const struct nf_bridge_info *nf_bridge)
 434 {
 435         switch (skb->protocol) {
 436         case htons(ETH_P_IP):
 437                 return ip_hdr(skb)->daddr != nf_bridge->ipv4_daddr;
 438         case htons(ETH_P_IPV6):
 439                 return memcmp(&nf_bridge->ipv6_daddr, &ipv6_hdr(skb)->daddr,
 440                               sizeof(ipv6_hdr(skb)->daddr)) != 0;
 441         default:
 442                 return false;
 443         }
 444 }
 445
 446 /* PF_BRIDGE/PRE_ROUTING: Undo the changes made for ip6tables
 447  * PREROUTING and continue the bridge PRE_ROUTING hook. See comment
 448  * for br_nf_pre_routing_finish(), same logic is used here but
 449  * equivalent IPv6 function ip6_route_input() called indirectly.
 450  */
 451 static int br_nf_pre_routing_finish_ipv6(struct sock *sk, struct sk_buff *skb)
 452 {
 453         struct nf_bridge_info *nf_bridge = nf_bridge_info_get(skb);
 454         struct rtable *rt;
 455         struct net_device *dev = skb->dev;
 456         const struct nf_ipv6_ops *v6ops = nf_get_ipv6_ops();
 457
 458         nf_bridge->frag_max_size = IP6CB(skb)->frag_max_size;
 459
 460         if (nf_bridge->pkt_otherhost) {
 461                 skb->pkt_type = PACKET_OTHERHOST;
 462                 nf_bridge->pkt_otherhost = false;
 463         }
 464         nf_bridge->mask &= ~BRNF_NF_BRIDGE_PREROUTING;
 465         if (daddr_was_changed(skb, nf_bridge)) {
 466                 skb_dst_drop(skb);
 467                 v6ops->route_input(skb);
 468
 469                 if (skb_dst(skb)->error) {
 470                         kfree_skb(skb);
 471                         return 0;
 472                 }
 473
 474                 if (skb_dst(skb)->dev == dev) {
 475                         skb->dev = nf_bridge->physindev;
 476                         nf_bridge_update_protocol(skb);
 477                         nf_bridge_push_encap_header(skb);
 478                         NF_HOOK_THRESH(NFPROTO_BRIDGE, NF_BR_PRE_ROUTING,
 479                                        sk, skb, skb->dev, NULL,
 480                                        br_nf_pre_routing_finish_bridge,
 481                                        1);
 482                         return 0;
 483                 }
 484                 ether_addr_copy(eth_hdr(skb)->h_dest, dev->dev_addr);
 485                 skb->pkt_type = PACKET_HOST;
 486         } else {
 487                 rt = bridge_parent_rtable(nf_bridge->physindev);
 488                 if (!rt) {
 489                         kfree_skb(skb);
 490                         return 0;
 491                 }
 492                 skb_dst_set_noref(skb, &rt->dst);
 493         }
 494
 495         skb->dev = nf_bridge->physindev;
 496         nf_bridge_update_protocol(skb);
 497         nf_bridge_push_encap_header(skb);
 498         NF_HOOK_THRESH(NFPROTO_BRIDGE, NF_BR_PRE_ROUTING, sk, skb,
 499                        skb->dev, NULL,
 500                        br_handle_frame_finish, 1);
 501
 502         return 0;
 503 }
 504
 505 /* This requires some explaining. If DNAT has taken place,
 506  * we will need to fix up the destination Ethernet address.
 507  * This is also true when SNAT takes place (for the reply direction).
 508  *
 509  * There are two cases to consider:
 510  * 1. The packet was DNAT'ed to a device in the same bridge
 511  *    port group as it was received on. We can still bridge
 512  *    the packet.
 513  * 2. The packet was DNAT'ed to a different device, either
 514  *    a non-bridged device or another bridge port group.
 515  *    The packet will need to be routed.
 516  *
 517  * The correct way of distinguishing between these two cases is to
 518  * call ip_route_input() and to look at skb->dst->dev, which is
 519  * changed to the destination device if ip_route_input() succeeds.
 520  *
 521  * Let's first consider the case that ip_route_input() succeeds:
 522  *
 523  * If the output device equals the logical bridge device the packet
 524  * came in on, we can consider this bridging. The corresponding MAC
 525  * address will be obtained in br_nf_pre_routing_finish_bridge.
 526  * Otherwise, the packet is considered to be routed and we just
 527  * change the destination MAC address so that the packet will
 528  * later be passed up to the IP stack to be routed. For a redirected
 529  * packet, ip_route_input() will give back the localhost as output device,
 530  * which differs from the bridge device.
 531  *
 532  * Let's now consider the case that ip_route_input() fails:
 533  *
 534  * This can be because the destination address is martian, in which case
 535  * the packet will be dropped.
 536  * If IP forwarding is disabled, ip_route_input() will fail, while
 537  * ip_route_output_key() can return success. The source
 538  * address for ip_route_output_key() is set to zero, so ip_route_output_key()
 539  * thinks we're handling a locally generated packet and won't care
 540  * if IP forwarding is enabled. If the output device equals the logical bridge
 541  * device, we proceed as if ip_route_input() succeeded. If it differs from the
 542  * logical bridge port or if ip_route_output_key() fails we drop the packet.
 543  */
 544 static int br_nf_pre_routing_finish(struct sock *sk, struct sk_buff *skb)
 545 {
 546         struct net_device *dev = skb->dev;
 547         struct iphdr *iph = ip_hdr(skb);
 548         struct nf_bridge_info *nf_bridge = nf_bridge_info_get(skb);
 549         struct rtable *rt;
 550         int err;
 551
 552         nf_bridge->frag_max_size = IPCB(skb)->frag_max_size;
 553
 554         if (nf_bridge->pkt_otherhost) {
 555                 skb->pkt_type = PACKET_OTHERHOST;
 556                 nf_bridge->pkt_otherhost = false;
 557         }
 558         nf_bridge->mask &= ~BRNF_NF_BRIDGE_PREROUTING;
 559         if (daddr_was_changed(skb, nf_bridge)) {
 560                 if ((err = ip_route_input(skb, iph->daddr, iph->saddr, iph->tos, dev))) {
 561                         struct in_device *in_dev = __in_dev_get_rcu(dev);
 562
 563                         /* If err equals -EHOSTUNREACH the error is due to a
 564                          * martian destination or due to the fact that
 565                          * forwarding is disabled. For most martian packets,
 566                          * ip_route_output_key() will fail. It won't fail for 2 types of
 567                          * martian destinations: loopback destinations and destination
 568                          * 0.0.0.0. In both cases the packet will be dropped because the
 569                          * destination is the loopback device and not the bridge. */
 570                         if (err != -EHOSTUNREACH || !in_dev || IN_DEV_FORWARD(in_dev))
 571                                 goto free_skb;
 572
 573                         rt = ip_route_output(dev_net(dev), iph->daddr, 0,
 574                                              RT_TOS(iph->tos), 0);
 575                         if (!IS_ERR(rt)) {
 576                                 /* - Bridged-and-DNAT'ed traffic doesn't
 577                                  *   require ip_forwarding. */
 578                                 if (rt->dst.dev == dev) {
 579                                         skb_dst_set(skb, &rt->dst);
 580                                         goto bridged_dnat;
 581                                 }
 582                                 ip_rt_put(rt);
 583                         }
 584 free_skb:
 585                         kfree_skb(skb);
 586                         return 0;
 587                 } else {
 588                         if (skb_dst(skb)->dev == dev) {
 589 bridged_dnat:
 590                                 skb->dev = nf_bridge->physindev;
 591                                 nf_bridge_update_protocol(skb);
 592                                 nf_bridge_push_encap_header(skb);
 593                                 NF_HOOK_THRESH(NFPROTO_BRIDGE,
 594                                                NF_BR_PRE_ROUTING,
 595                                                sk, skb, skb->dev, NULL,
 596                                                br_nf_pre_routing_finish_bridge,
 597                                                1);
 598                                 return 0;
 599                         }
 600                         ether_addr_copy(eth_hdr(skb)->h_dest, dev->dev_addr);
 601                         skb->pkt_type = PACKET_HOST;
 602                 }
 603         } else {
 604                 rt = bridge_parent_rtable(nf_bridge->physindev);
 605                 if (!rt) {
 606                         kfree_skb(skb);
 607                         return 0;
 608                 }
 609                 skb_dst_set_noref(skb, &rt->dst);
 610         }
 611
 612         skb->dev = nf_bridge->physindev;
 613         nf_bridge_update_protocol(skb);
 614         nf_bridge_push_encap_header(skb);
 615         NF_HOOK_THRESH(NFPROTO_BRIDGE, NF_BR_PRE_ROUTING, sk, skb,
 616                        skb->dev, NULL,
 617                        br_handle_frame_finish, 1);
 618
 619         return 0;
 620 }
 621
 622 static struct net_device *brnf_get_logical_dev(struct sk_buff *skb, const struct net_device *dev)
 623 {
 624         struct net_device *vlan, *br;
 625
 626         br = bridge_parent(dev);
 627         if (brnf_pass_vlan_indev == 0 || !skb_vlan_tag_present(skb))
 628                 return br;
 629
 630         vlan = __vlan_find_dev_deep_rcu(br, skb->vlan_proto,
 631                                     skb_vlan_tag_get(skb) & VLAN_VID_MASK);
 632
 633         return vlan ? vlan : br;
 634 }
 635
 636 /* Some common code for IPv4/IPv6 */
 637 static struct net_device *setup_pre_routing(struct sk_buff *skb)
 638 {
 639         struct nf_bridge_info *nf_bridge = nf_bridge_info_get(skb);
 640
 641         if (skb->pkt_type == PACKET_OTHERHOST) {
 642                 skb->pkt_type = PACKET_HOST;
 643                 nf_bridge->pkt_otherhost = true;
 644         }
 645
 646         nf_bridge->mask |= BRNF_NF_BRIDGE_PREROUTING;
 647         nf_bridge->physindev = skb->dev;
 648         skb->dev = brnf_get_logical_dev(skb, skb->dev);
 649
 650         if (skb->protocol == htons(ETH_P_8021Q))
 651                 nf_bridge->orig_proto = BRNF_PROTO_8021Q;
 652         else if (skb->protocol == htons(ETH_P_PPP_SES))
 653                 nf_bridge->orig_proto = BRNF_PROTO_PPPOE;
 654
 655         /* Must drop socket now because of tproxy. */
 656         skb_orphan(skb);
 657         return skb->dev;
 658 }
 659
 660 /* Replicate the checks that IPv6 does on packet reception and pass the packet
 661  * to ip6tables.
 662  */
 663 static unsigned int br_nf_pre_routing_ipv6(const struct nf_hook_ops *ops,
 664                                            struct sk_buff *skb,
 665                                            const struct nf_hook_state *state)
 666 {
 667         struct nf_bridge_info *nf_bridge;
 668
 669         if (br_validate_ipv6(skb))
 670                 return NF_DROP;
 671
 672         nf_bridge_put(skb->nf_bridge);
 673         if (!nf_bridge_alloc(skb))
 674                 return NF_DROP;
 675         if (!setup_pre_routing(skb))
 676                 return NF_DROP;
 677
 678         nf_bridge = nf_bridge_info_get(skb);
 679         nf_bridge->ipv6_daddr = ipv6_hdr(skb)->daddr;
 680
 681         skb->protocol = htons(ETH_P_IPV6);
 682         NF_HOOK(NFPROTO_IPV6, NF_INET_PRE_ROUTING, state->sk, skb,
 683                 skb->dev, NULL,
 684                 br_nf_pre_routing_finish_ipv6);
 685
 686         return NF_STOLEN;
 687 }
 688
 689 /* Direct IPv6 traffic to br_nf_pre_routing_ipv6.
 690  * Replicate the checks that IPv4 does on packet reception.
 691  * Set skb->dev to the bridge device (i.e. parent of the
 692  * receiving device) to make netfilter happy, the REDIRECT
 693  * target in particular.  Save the original destination IP
 694  * address to be able to detect DNAT afterwards. */
 695 static unsigned int br_nf_pre_routing(const struct nf_hook_ops *ops,
 696                                       struct sk_buff *skb,
 697                                       const struct nf_hook_state *state)
 698 {
 699         struct nf_bridge_info *nf_bridge;
 700         struct net_bridge_port *p;
 701         struct net_bridge *br;
 702         __u32 len = nf_bridge_encap_header_len(skb);
 703
 704         if (unlikely(!pskb_may_pull(skb, len)))
 705                 return NF_DROP;
 706
 707         p = br_port_get_rcu(state->in);
 708         if (p == NULL)
 709                 return NF_DROP;
 710         br = p->br;
 711
 712         if (IS_IPV6(skb) || IS_VLAN_IPV6(skb) || IS_PPPOE_IPV6(skb)) {
 713                 if (!brnf_call_ip6tables && !br->nf_call_ip6tables)
 714                         return NF_ACCEPT;
 715
 716                 nf_bridge_pull_encap_header_rcsum(skb);
 717                 return br_nf_pre_routing_ipv6(ops, skb, state);
 718         }
 719
 720         if (!brnf_call_iptables && !br->nf_call_iptables)
 721                 return NF_ACCEPT;
 722
 723         if (!IS_IP(skb) && !IS_VLAN_IP(skb) && !IS_PPPOE_IP(skb))
 724                 return NF_ACCEPT;
 725
 726         nf_bridge_pull_encap_header_rcsum(skb);
 727
 728         if (br_validate_ipv4(skb))
 729                 return NF_DROP;
 730
 731         nf_bridge_put(skb->nf_bridge);
 732         if (!nf_bridge_alloc(skb))
 733                 return NF_DROP;
 734         if (!setup_pre_routing(skb))
 735                 return NF_DROP;
 736
 737         nf_bridge = nf_bridge_info_get(skb);
 738         nf_bridge->ipv4_daddr = ip_hdr(skb)->daddr;
 739
 740         skb->protocol = htons(ETH_P_IP);
 741
 742         NF_HOOK(NFPROTO_IPV4, NF_INET_PRE_ROUTING, state->sk, skb,
 743                 skb->dev, NULL,
 744                 br_nf_pre_routing_finish);
 745
 746         return NF_STOLEN;
 747 }
 748
 749
 750 /* PF_BRIDGE/LOCAL_IN ************************************************/
 751 /* The packet is locally destined, which requires a real
 752  * dst_entry, so detach the fake one.  On the way up, the
 753  * packet would pass through PRE_ROUTING again (which already
 754  * took place when the packet entered the bridge), but we
 755  * register an IPv4 PRE_ROUTING 'sabotage' hook that will
 756  * prevent this from happening. */
 757 static unsigned int br_nf_local_in(const struct nf_hook_ops *ops,
 758                                    struct sk_buff *skb,
 759                                    const struct nf_hook_state *state)
 760 {
 761         br_drop_fake_rtable(skb);
 762         return NF_ACCEPT;
 763 }
 764
 765 /* PF_BRIDGE/FORWARD *************************************************/
 766 static int br_nf_forward_finish(struct sock *sk, struct sk_buff *skb)
 767 {
 768         struct nf_bridge_info *nf_bridge = nf_bridge_info_get(skb);
 769         struct net_device *in;
 770
 771         if (!IS_ARP(skb) && !IS_VLAN_ARP(skb)) {
 772
 773                 if (skb->protocol == htons(ETH_P_IP))
 774                         nf_bridge->frag_max_size = IPCB(skb)->frag_max_size;
 775
 776                 if (skb->protocol == htons(ETH_P_IPV6))
 777                         nf_bridge->frag_max_size = IP6CB(skb)->frag_max_size;
 778
 779                 in = nf_bridge->physindev;
 780                 if (nf_bridge->pkt_otherhost) {
 781                         skb->pkt_type = PACKET_OTHERHOST;
 782                         nf_bridge->pkt_otherhost = false;
 783                 }
 784                 nf_bridge_update_protocol(skb);
 785         } else {
 786                 in = *((struct net_device **)(skb->cb));
 787         }
 788         nf_bridge_push_encap_header(skb);
 789
 790         NF_HOOK_THRESH(NFPROTO_BRIDGE, NF_BR_FORWARD, sk, skb,
 791                        in, skb->dev, br_forward_finish, 1);
 792         return 0;
 793 }
 794
 795
 796 /* This is the 'purely bridged' case.  For IP, we pass the packet to
 797  * netfilter with indev and outdev set to the bridge device,
 798  * but we are still able to filter on the 'real' indev/outdev
 799  * because of the physdev module. For ARP, indev and outdev are the
 800  * bridge ports. */
 801 static unsigned int br_nf_forward_ip(const struct nf_hook_ops *ops,
 802                                      struct sk_buff *skb,
 803                                      const struct nf_hook_state *state)
 804 {
 805         struct nf_bridge_info *nf_bridge;
 806         struct net_device *parent;
 807         u_int8_t pf;
 808
 809         if (!skb->nf_bridge)
 810                 return NF_ACCEPT;
 811
 812         /* Need exclusive nf_bridge_info since we might have multiple
 813          * different physoutdevs. */
 814         if (!nf_bridge_unshare(skb))
 815                 return NF_DROP;
 816
 817         nf_bridge = nf_bridge_info_get(skb);
 818         if (!nf_bridge)
 819                 return NF_DROP;
 820
 821         parent = bridge_parent(state->out);
 822         if (!parent)
 823                 return NF_DROP;
 824
 825         if (IS_IP(skb) || IS_VLAN_IP(skb) || IS_PPPOE_IP(skb))
 826                 pf = NFPROTO_IPV4;
 827         else if (IS_IPV6(skb) || IS_VLAN_IPV6(skb) || IS_PPPOE_IPV6(skb))
 828                 pf = NFPROTO_IPV6;
 829         else
 830                 return NF_ACCEPT;
 831
 832         nf_bridge_pull_encap_header(skb);
 833
 834         if (skb->pkt_type == PACKET_OTHERHOST) {
 835                 skb->pkt_type = PACKET_HOST;
 836                 nf_bridge->pkt_otherhost = true;
 837         }
 838
 839         if (pf == NFPROTO_IPV4) {
 840                 if (br_validate_ipv4(skb))
 841                         return NF_DROP;
 842                 IPCB(skb)->frag_max_size = nf_bridge->frag_max_size;
 843         }
 844
 845         if (pf == NFPROTO_IPV6) {
 846                 if (br_validate_ipv6(skb))
 847                         return NF_DROP;
 848                 IP6CB(skb)->frag_max_size = nf_bridge->frag_max_size;
 849         }
 850
 851         nf_bridge->physoutdev = skb->dev;
 852         if (pf == NFPROTO_IPV4)
 853                 skb->protocol = htons(ETH_P_IP);
 854         else
 855                 skb->protocol = htons(ETH_P_IPV6);
 856
 857         NF_HOOK(pf, NF_INET_FORWARD, NULL, skb,
 858                 brnf_get_logical_dev(skb, state->in),
 859                 parent, br_nf_forward_finish);
 860
 861         return NF_STOLEN;
 862 }
 863
 864 static unsigned int br_nf_forward_arp(const struct nf_hook_ops *ops,
 865                                       struct sk_buff *skb,
 866                                       const struct nf_hook_state *state)
 867 {
 868         struct net_bridge_port *p;
 869         struct net_bridge *br;
 870         struct net_device **d = (struct net_device **)(skb->cb);
 871
 872         p = br_port_get_rcu(state->out);
 873         if (p == NULL)
 874                 return NF_ACCEPT;
 875         br = p->br;
 876
 877         if (!brnf_call_arptables && !br->nf_call_arptables)
 878                 return NF_ACCEPT;
 879
 880         if (!IS_ARP(skb)) {
 881                 if (!IS_VLAN_ARP(skb))
 882                         return NF_ACCEPT;
 883                 nf_bridge_pull_encap_header(skb);
 884         }
 885
 886         if (arp_hdr(skb)->ar_pln != 4) {
 887                 if (IS_VLAN_ARP(skb))
 888                         nf_bridge_push_encap_header(skb);
 889                 return NF_ACCEPT;
 890         }
 891         *d = state->in;
 892         NF_HOOK(NFPROTO_ARP, NF_ARP_FORWARD, state->sk, skb,
 893                 state->in, state->out, br_nf_forward_finish);
 894
 895         return NF_STOLEN;
 896 }
 897
 898 #if IS_ENABLED(CONFIG_NF_DEFRAG_IPV4) || IS_ENABLED(CONFIG_NF_DEFRAG_IPV6)
 899 static int br_nf_push_frag_xmit(struct sock *sk, struct sk_buff *skb)
 900 {
 901         struct brnf_frag_data *data;
 902         int err;
 903
 904         data = this_cpu_ptr(&brnf_frag_data_storage);
 905         err = skb_cow_head(skb, data->size);
 906
 907         if (err) {
 908                 kfree_skb(skb);
 909                 return 0;
 910         }
 911
 912         skb_copy_to_linear_data_offset(skb, -data->size, data->mac, data->size);
 913         __skb_push(skb, data->encap_size);
 914
 915         nf_bridge_info_free(skb);
 916         return br_dev_queue_push_xmit(sk, skb);
 917 }
 918 #endif
 919
 920 static int br_nf_ip_fragment(struct sock *sk, struct sk_buff *skb,
 921                              int (*output)(struct sock *, struct sk_buff *))
 922 {
 923         unsigned int mtu = ip_skb_dst_mtu(skb);
 924         struct iphdr *iph = ip_hdr(skb);
 925         struct rtable *rt = skb_rtable(skb);
 926         struct net_device *dev = rt->dst.dev;
 927
 928         if (unlikely(((iph->frag_off & htons(IP_DF)) && !skb->ignore_df) ||
 929                      (IPCB(skb)->frag_max_size &&
 930                       IPCB(skb)->frag_max_size > mtu))) {
 931                 IP_INC_STATS(dev_net(dev), IPSTATS_MIB_FRAGFAILS);
 932                 kfree_skb(skb);
 933                 return -EMSGSIZE;
 934         }
 935
 936         return ip_do_fragment(sk, skb, output);
 937 }
 938
 939 static unsigned int nf_bridge_mtu_reduction(const struct sk_buff *skb)
 940 {
 941         if (skb->nf_bridge->orig_proto == BRNF_PROTO_PPPOE)
 942                 return PPPOE_SES_HLEN;
 943         return 0;
 944 }
 945
 946 static int br_nf_dev_queue_xmit(struct sock *sk, struct sk_buff *skb)
 947 {
 948         struct nf_bridge_info *nf_bridge;
 949         unsigned int mtu_reserved;
 950
 951         mtu_reserved = nf_bridge_mtu_reduction(skb);
 952
 953         if (skb_is_gso(skb) || skb->len + mtu_reserved <= skb->dev->mtu) {
 954                 nf_bridge_info_free(skb);
 955                 return br_dev_queue_push_xmit(sk, skb);
 956         }
 957
 958         nf_bridge = nf_bridge_info_get(skb);
 959
 960 #if IS_ENABLED(CONFIG_NF_DEFRAG_IPV4)
 961         /* This is wrong! We should preserve the original fragment
 962          * boundaries by preserving frag_list rather than refragmenting.
 963          */
 964         if (skb->protocol == htons(ETH_P_IP)) {
 965                 struct brnf_frag_data *data;
 966
 967                 if (br_validate_ipv4(skb))
 968                         return NF_DROP;
 969
 970                 IPCB(skb)->frag_max_size = nf_bridge->frag_max_size;
 971
 972                 nf_bridge_update_protocol(skb);
 973
 974                 data = this_cpu_ptr(&brnf_frag_data_storage);
 975                 data->encap_size = nf_bridge_encap_header_len(skb);
 976                 data->size = ETH_HLEN + data->encap_size;
 977
 978                 skb_copy_from_linear_data_offset(skb, -data->size, data->mac,
 979                                                  data->size);
 980
 981                 return br_nf_ip_fragment(sk, skb, br_nf_push_frag_xmit);
 982         }
 983 #endif
 984 #if IS_ENABLED(CONFIG_NF_DEFRAG_IPV6)
 985         if (skb->protocol == htons(ETH_P_IPV6)) {
 986                 const struct nf_ipv6_ops *v6ops = nf_get_ipv6_ops();
 987                 struct brnf_frag_data *data;
 988
 989                 if (br_validate_ipv6(skb))
 990                         return NF_DROP;
 991
 992                 IP6CB(skb)->frag_max_size = nf_bridge->frag_max_size;
 993
 994                 nf_bridge_update_protocol(skb);
 995
 996                 data = this_cpu_ptr(&brnf_frag_data_storage);
 997                 data->encap_size = nf_bridge_encap_header_len(skb);
 998                 data->size = ETH_HLEN + data->encap_size;
 999
1000                 skb_copy_from_linear_data_offset(skb, -data->size, data->mac,
1001                                                  data->size);
1002
1003                 if (v6ops)
1004                         return v6ops->fragment(sk, skb, br_nf_push_frag_xmit);
1005                 else
1006                         return -EMSGSIZE;
1007         }
1008 #endif
1009         nf_bridge_info_free(skb);
1010         return br_dev_queue_push_xmit(sk, skb);
1011 }
1012
1013 /* PF_BRIDGE/POST_ROUTING ********************************************/
1014 static unsigned int br_nf_post_routing(const struct nf_hook_ops *ops,
1015                                        struct sk_buff *skb,
1016                                        const struct nf_hook_state *state)
1017 {
1018         struct nf_bridge_info *nf_bridge = nf_bridge_info_get(skb);
1019         struct net_device *realoutdev = bridge_parent(skb->dev);
1020         u_int8_t pf;
1021
1022         /* if nf_bridge is set, but ->physoutdev is NULL, this packet came in
1023          * on a bridge, but was delivered locally and is now being routed:
1024          *
1025          * POST_ROUTING was already invoked from the ip stack.
1026          */
1027         if (!nf_bridge || !nf_bridge->physoutdev)
1028                 return NF_ACCEPT;
1029
1030         if (!realoutdev)
1031                 return NF_DROP;
1032
1033         if (IS_IP(skb) || IS_VLAN_IP(skb) || IS_PPPOE_IP(skb))
1034                 pf = NFPROTO_IPV4;
1035         else if (IS_IPV6(skb) || IS_VLAN_IPV6(skb) || IS_PPPOE_IPV6(skb))
1036                 pf = NFPROTO_IPV6;
1037         else
1038                 return NF_ACCEPT;
1039
1040         /* We assume any code from br_dev_queue_push_xmit onwards doesn't care
1041          * about the value of skb->pkt_type. */
1042         if (skb->pkt_type == PACKET_OTHERHOST) {
1043                 skb->pkt_type = PACKET_HOST;
1044                 nf_bridge->pkt_otherhost = true;
1045         }
1046
1047         nf_bridge_pull_encap_header(skb);
1048         if (pf == NFPROTO_IPV4)
1049                 skb->protocol = htons(ETH_P_IP);
1050         else
1051                 skb->protocol = htons(ETH_P_IPV6);
1052
1053         NF_HOOK(pf, NF_INET_POST_ROUTING, state->sk, skb,
1054                 NULL, realoutdev,
1055                 br_nf_dev_queue_xmit);
1056
1057         return NF_STOLEN;
1058 }
1059
1060 /* IP/SABOTAGE *****************************************************/
1061 /* Don't hand locally destined packets to PF_INET(6)/PRE_ROUTING
1062  * for the second time. */
1063 static unsigned int ip_sabotage_in(const struct nf_hook_ops *ops,
1064                                    struct sk_buff *skb,
1065                                    const struct nf_hook_state *state)
1066 {
1067         if (skb->nf_bridge &&
1068             !(skb->nf_bridge->mask & BRNF_NF_BRIDGE_PREROUTING)) {
1069                 return NF_STOP;
1070         }
1071
1072         return NF_ACCEPT;
1073 }
1074
1075 /* This is called when br_netfilter has called into iptables/netfilter,
1076  * and DNAT has taken place on a bridge-forwarded packet.
1077  *
1078  * neigh->output has created a new MAC header, with local br0 MAC
1079  * as saddr.
1080  *
1081  * This restores the original MAC saddr of the bridged packet
1082  * before invoking bridge forward logic to transmit the packet.
1083  */
1084 static void br_nf_pre_routing_finish_bridge_slow(struct sk_buff *skb)
1085 {
1086         struct nf_bridge_info *nf_bridge = nf_bridge_info_get(skb);
1087
1088         skb_pull(skb, ETH_HLEN);
1089         nf_bridge->mask &= ~BRNF_BRIDGED_DNAT;
1090
1091         BUILD_BUG_ON(sizeof(nf_bridge->neigh_header) != (ETH_HLEN - ETH_ALEN));
1092
1093         skb_copy_to_linear_data_offset(skb, -(ETH_HLEN - ETH_ALEN),
1094                                        nf_bridge->neigh_header,
1095                                        ETH_HLEN - ETH_ALEN);
1096         skb->dev = nf_bridge->physindev;
1097
1098         nf_bridge->physoutdev = NULL;
1099         br_handle_frame_finish(NULL, skb);
1100 }
1101
1102 static int br_nf_dev_xmit(struct sk_buff *skb)
1103 {
1104         if (skb->nf_bridge && (skb->nf_bridge->mask & BRNF_BRIDGED_DNAT)) {
1105                 br_nf_pre_routing_finish_bridge_slow(skb);
1106                 return 1;
1107         }
1108         return 0;
1109 }
1110
1111 static const struct nf_br_ops br_ops = {
1112         .br_dev_xmit_hook =     br_nf_dev_xmit,
1113 };
1114
1115 void br_netfilter_enable(void)
1116 {
1117 }
1118 EXPORT_SYMBOL_GPL(br_netfilter_enable);
1119
1120 /* For br_nf_post_routing, we need (prio = NF_BR_PRI_LAST), because
1121  * br_dev_queue_push_xmit is called afterwards */
1122 static struct nf_hook_ops br_nf_ops[] __read_mostly = {
1123         {
1124                 .hook = br_nf_pre_routing,
1125                 .owner = THIS_MODULE,
1126                 .pf = NFPROTO_BRIDGE,
1127                 .hooknum = NF_BR_PRE_ROUTING,
1128                 .priority = NF_BR_PRI_BRNF,
1129         },
1130         {
1131                 .hook = br_nf_local_in,
1132                 .owner = THIS_MODULE,
1133                 .pf = NFPROTO_BRIDGE,
1134                 .hooknum = NF_BR_LOCAL_IN,
1135                 .priority = NF_BR_PRI_BRNF,
1136         },
1137         {
1138                 .hook = br_nf_forward_ip,
1139                 .owner = THIS_MODULE,
1140                 .pf = NFPROTO_BRIDGE,
1141                 .hooknum = NF_BR_FORWARD,
1142                 .priority = NF_BR_PRI_BRNF - 1,
1143         },
1144         {
1145                 .hook = br_nf_forward_arp,
1146                 .owner = THIS_MODULE,
1147                 .pf = NFPROTO_BRIDGE,
1148                 .hooknum = NF_BR_FORWARD,
1149                 .priority = NF_BR_PRI_BRNF,
1150         },
1151         {
1152                 .hook = br_nf_post_routing,
1153                 .owner = THIS_MODULE,
1154                 .pf = NFPROTO_BRIDGE,
1155                 .hooknum = NF_BR_POST_ROUTING,
1156                 .priority = NF_BR_PRI_LAST,
1157         },
1158         {
1159                 .hook = ip_sabotage_in,
1160                 .owner = THIS_MODULE,
1161                 .pf = NFPROTO_IPV4,
1162                 .hooknum = NF_INET_PRE_ROUTING,
1163                 .priority = NF_IP_PRI_FIRST,
1164         },
1165         {
1166                 .hook = ip_sabotage_in,
1167                 .owner = THIS_MODULE,
1168                 .pf = NFPROTO_IPV6,
1169                 .hooknum = NF_INET_PRE_ROUTING,
1170                 .priority = NF_IP6_PRI_FIRST,
1171         },
1172 };
1173
1174 #ifdef CONFIG_SYSCTL
1175 static
1176 int brnf_sysctl_call_tables(struct ctl_table *ctl, int write,
1177                             void __user *buffer, size_t *lenp, loff_t *ppos)
1178 {
1179         int ret;
1180
1181         ret = proc_dointvec(ctl, write, buffer, lenp, ppos);
1182
1183         if (write && *(int *)(ctl->data))
1184                 *(int *)(ctl->data) = 1;
1185         return ret;
1186 }
1187
1188 static struct ctl_table brnf_table[] = {
1189         {
1190                 .procname       = "bridge-nf-call-arptables",
1191                 .data           = &brnf_call_arptables,
1192                 .maxlen         = sizeof(int),
1193                 .mode           = 0644,
1194                 .proc_handler   = brnf_sysctl_call_tables,
1195         },
1196         {
1197                 .procname       = "bridge-nf-call-iptables",
1198                 .data           = &brnf_call_iptables,
1199                 .maxlen         = sizeof(int),
1200                 .mode           = 0644,
1201                 .proc_handler   = brnf_sysctl_call_tables,
1202         },
1203         {
1204                 .procname       = "bridge-nf-call-ip6tables",
1205                 .data           = &brnf_call_ip6tables,
1206                 .maxlen         = sizeof(int),
1207                 .mode           = 0644,
1208                 .proc_handler   = brnf_sysctl_call_tables,
1209         },
1210         {
1211                 .procname       = "bridge-nf-filter-vlan-tagged",
1212                 .data           = &brnf_filter_vlan_tagged,
1213                 .maxlen         = sizeof(int),
1214                 .mode           = 0644,
1215                 .proc_handler   = brnf_sysctl_call_tables,
1216         },
1217         {
1218                 .procname       = "bridge-nf-filter-pppoe-tagged",
1219                 .data           = &brnf_filter_pppoe_tagged,
1220                 .maxlen         = sizeof(int),
1221                 .mode           = 0644,
1222                 .proc_handler   = brnf_sysctl_call_tables,
1223         },
1224         {
1225                 .procname       = "bridge-nf-pass-vlan-input-dev",
1226                 .data           = &brnf_pass_vlan_indev,
1227                 .maxlen         = sizeof(int),
1228                 .mode           = 0644,
1229                 .proc_handler   = brnf_sysctl_call_tables,
1230         },
1231         { }
1232 };
1233 #endif
1234
1235 static int __init br_netfilter_init(void)
1236 {
1237         int ret;
1238
1239         ret = nf_register_hooks(br_nf_ops, ARRAY_SIZE(br_nf_ops));
1240         if (ret < 0)
1241                 return ret;
1242
1243 #ifdef CONFIG_SYSCTL
1244         brnf_sysctl_header = register_net_sysctl(&init_net, "net/bridge", brnf_table);
1245         if (brnf_sysctl_header == NULL) {
1246                 printk(KERN_WARNING
1247                        "br_netfilter: can't register to sysctl.\n");
1248                 nf_unregister_hooks(br_nf_ops, ARRAY_SIZE(br_nf_ops));
1249                 return -ENOMEM;
1250         }
1251 #endif
1252         RCU_INIT_POINTER(nf_br_ops, &br_ops);
1253         printk(KERN_NOTICE "Bridge firewalling registered\n");
1254         return 0;
1255 }
1256
1257 static void __exit br_netfilter_fini(void)
1258 {
1259         RCU_INIT_POINTER(nf_br_ops, NULL);
1260         nf_unregister_hooks(br_nf_ops, ARRAY_SIZE(br_nf_ops));
1261 #ifdef CONFIG_SYSCTL
1262         unregister_net_sysctl_table(brnf_sysctl_header);
1263 #endif
1264 }
1265
1266 module_init(br_netfilter_init);
1267 module_exit(br_netfilter_fini);
1268
1269 MODULE_LICENSE("GPL");
1270 MODULE_AUTHOR("Lennert Buytenhek <buytenh@gnu.org>");
1271 MODULE_AUTHOR("Bart De Schuymer <bdschuym@pandora.be>");
1272 MODULE_DESCRIPTION("Linux ethernet netfilter firewall bridge");