net/bridge/br_netfilter_hooks.c

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