| 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; |
| 53 | static int brnf_filter_pppoe_tagged __read_mostly; |
| 54 | static int brnf_pass_vlan_indev __read_mostly; |
| 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) || IS_ENABLED(CONFIG_NF_DEFRAG_IPV6) |
| 115 | struct brnf_frag_data { |
| 116 | char mac[NF_BRIDGE_MAX_MAC_HEADER_LENGTH]; |
| 117 | u8 encap_size; |
| 118 | u8 size; |
| 119 | u16 vlan_tci; |
| 120 | __be16 vlan_proto; |
| 121 | }; |
| 122 | |
| 123 | static DEFINE_PER_CPU(struct brnf_frag_data, brnf_frag_data_storage); |
| 124 | #endif |
| 125 | |
| 126 | static void nf_bridge_info_free(struct sk_buff *skb) |
| 127 | { |
| 128 | if (skb->nf_bridge) { |
| 129 | nf_bridge_put(skb->nf_bridge); |
| 130 | skb->nf_bridge = NULL; |
| 131 | } |
| 132 | } |
| 133 | |
| 134 | static inline struct net_device *bridge_parent(const struct net_device *dev) |
| 135 | { |
| 136 | struct net_bridge_port *port; |
| 137 | |
| 138 | port = br_port_get_rcu(dev); |
| 139 | return port ? port->br->dev : NULL; |
| 140 | } |
| 141 | |
| 142 | static inline struct nf_bridge_info *nf_bridge_unshare(struct sk_buff *skb) |
| 143 | { |
| 144 | struct nf_bridge_info *nf_bridge = skb->nf_bridge; |
| 145 | |
| 146 | if (atomic_read(&nf_bridge->use) > 1) { |
| 147 | struct nf_bridge_info *tmp = nf_bridge_alloc(skb); |
| 148 | |
| 149 | if (tmp) { |
| 150 | memcpy(tmp, nf_bridge, sizeof(struct nf_bridge_info)); |
| 151 | atomic_set(&tmp->use, 1); |
| 152 | } |
| 153 | nf_bridge_put(nf_bridge); |
| 154 | nf_bridge = tmp; |
| 155 | } |
| 156 | return nf_bridge; |
| 157 | } |
| 158 | |
| 159 | unsigned int nf_bridge_encap_header_len(const struct sk_buff *skb) |
| 160 | { |
| 161 | switch (skb->protocol) { |
| 162 | case __cpu_to_be16(ETH_P_8021Q): |
| 163 | return VLAN_HLEN; |
| 164 | case __cpu_to_be16(ETH_P_PPP_SES): |
| 165 | return PPPOE_SES_HLEN; |
| 166 | default: |
| 167 | return 0; |
| 168 | } |
| 169 | } |
| 170 | |
| 171 | static inline void nf_bridge_pull_encap_header(struct sk_buff *skb) |
| 172 | { |
| 173 | unsigned int len = nf_bridge_encap_header_len(skb); |
| 174 | |
| 175 | skb_pull(skb, len); |
| 176 | skb->network_header += len; |
| 177 | } |
| 178 | |
| 179 | static inline void nf_bridge_pull_encap_header_rcsum(struct sk_buff *skb) |
| 180 | { |
| 181 | unsigned int len = nf_bridge_encap_header_len(skb); |
| 182 | |
| 183 | skb_pull_rcsum(skb, len); |
| 184 | skb->network_header += len; |
| 185 | } |
| 186 | |
| 187 | /* When handing a packet over to the IP layer |
| 188 | * check whether we have a skb that is in the |
| 189 | * expected format |
| 190 | */ |
| 191 | |
| 192 | static int br_validate_ipv4(struct sk_buff *skb) |
| 193 | { |
| 194 | const struct iphdr *iph; |
| 195 | struct net_device *dev = skb->dev; |
| 196 | u32 len; |
| 197 | |
| 198 | if (!pskb_may_pull(skb, sizeof(struct iphdr))) |
| 199 | goto inhdr_error; |
| 200 | |
| 201 | iph = ip_hdr(skb); |
| 202 | |
| 203 | /* Basic sanity checks */ |
| 204 | if (iph->ihl < 5 || iph->version != 4) |
| 205 | goto inhdr_error; |
| 206 | |
| 207 | if (!pskb_may_pull(skb, iph->ihl*4)) |
| 208 | goto inhdr_error; |
| 209 | |
| 210 | iph = ip_hdr(skb); |
| 211 | if (unlikely(ip_fast_csum((u8 *)iph, iph->ihl))) |
| 212 | goto inhdr_error; |
| 213 | |
| 214 | len = ntohs(iph->tot_len); |
| 215 | if (skb->len < len) { |
| 216 | IP_INC_STATS_BH(dev_net(dev), IPSTATS_MIB_INTRUNCATEDPKTS); |
| 217 | goto drop; |
| 218 | } else if (len < (iph->ihl*4)) |
| 219 | goto inhdr_error; |
| 220 | |
| 221 | if (pskb_trim_rcsum(skb, len)) { |
| 222 | IP_INC_STATS_BH(dev_net(dev), IPSTATS_MIB_INDISCARDS); |
| 223 | goto drop; |
| 224 | } |
| 225 | |
| 226 | memset(IPCB(skb), 0, sizeof(struct inet_skb_parm)); |
| 227 | /* We should really parse IP options here but until |
| 228 | * somebody who actually uses IP options complains to |
| 229 | * us we'll just silently ignore the options because |
| 230 | * we're lazy! |
| 231 | */ |
| 232 | return 0; |
| 233 | |
| 234 | inhdr_error: |
| 235 | IP_INC_STATS_BH(dev_net(dev), IPSTATS_MIB_INHDRERRORS); |
| 236 | drop: |
| 237 | return -1; |
| 238 | } |
| 239 | |
| 240 | void nf_bridge_update_protocol(struct sk_buff *skb) |
| 241 | { |
| 242 | switch (skb->nf_bridge->orig_proto) { |
| 243 | case BRNF_PROTO_8021Q: |
| 244 | skb->protocol = htons(ETH_P_8021Q); |
| 245 | break; |
| 246 | case BRNF_PROTO_PPPOE: |
| 247 | skb->protocol = htons(ETH_P_PPP_SES); |
| 248 | break; |
| 249 | case BRNF_PROTO_UNCHANGED: |
| 250 | break; |
| 251 | } |
| 252 | } |
| 253 | |
| 254 | /* Obtain the correct destination MAC address, while preserving the original |
| 255 | * source MAC address. If we already know this address, we just copy it. If we |
| 256 | * don't, we use the neighbour framework to find out. In both cases, we make |
| 257 | * sure that br_handle_frame_finish() is called afterwards. |
| 258 | */ |
| 259 | int br_nf_pre_routing_finish_bridge(struct sock *sk, struct sk_buff *skb) |
| 260 | { |
| 261 | struct neighbour *neigh; |
| 262 | struct dst_entry *dst; |
| 263 | |
| 264 | skb->dev = bridge_parent(skb->dev); |
| 265 | if (!skb->dev) |
| 266 | goto free_skb; |
| 267 | dst = skb_dst(skb); |
| 268 | neigh = dst_neigh_lookup_skb(dst, skb); |
| 269 | if (neigh) { |
| 270 | struct nf_bridge_info *nf_bridge = nf_bridge_info_get(skb); |
| 271 | int ret; |
| 272 | |
| 273 | if (neigh->hh.hh_len) { |
| 274 | neigh_hh_bridge(&neigh->hh, skb); |
| 275 | skb->dev = nf_bridge->physindev; |
| 276 | ret = br_handle_frame_finish(sk, skb); |
| 277 | } else { |
| 278 | /* the neighbour function below overwrites the complete |
| 279 | * MAC header, so we save the Ethernet source address and |
| 280 | * protocol number. |
| 281 | */ |
| 282 | skb_copy_from_linear_data_offset(skb, |
| 283 | -(ETH_HLEN-ETH_ALEN), |
| 284 | nf_bridge->neigh_header, |
| 285 | ETH_HLEN-ETH_ALEN); |
| 286 | /* tell br_dev_xmit to continue with forwarding */ |
| 287 | nf_bridge->bridged_dnat = 1; |
| 288 | /* FIXME Need to refragment */ |
| 289 | ret = neigh->output(neigh, skb); |
| 290 | } |
| 291 | neigh_release(neigh); |
| 292 | return ret; |
| 293 | } |
| 294 | free_skb: |
| 295 | kfree_skb(skb); |
| 296 | return 0; |
| 297 | } |
| 298 | |
| 299 | static inline bool |
| 300 | br_nf_ipv4_daddr_was_changed(const struct sk_buff *skb, |
| 301 | const struct nf_bridge_info *nf_bridge) |
| 302 | { |
| 303 | return ip_hdr(skb)->daddr != nf_bridge->ipv4_daddr; |
| 304 | } |
| 305 | |
| 306 | /* This requires some explaining. If DNAT has taken place, |
| 307 | * we will need to fix up the destination Ethernet address. |
| 308 | * This is also true when SNAT takes place (for the reply direction). |
| 309 | * |
| 310 | * There are two cases to consider: |
| 311 | * 1. The packet was DNAT'ed to a device in the same bridge |
| 312 | * port group as it was received on. We can still bridge |
| 313 | * the packet. |
| 314 | * 2. The packet was DNAT'ed to a different device, either |
| 315 | * a non-bridged device or another bridge port group. |
| 316 | * The packet will need to be routed. |
| 317 | * |
| 318 | * The correct way of distinguishing between these two cases is to |
| 319 | * call ip_route_input() and to look at skb->dst->dev, which is |
| 320 | * changed to the destination device if ip_route_input() succeeds. |
| 321 | * |
| 322 | * Let's first consider the case that ip_route_input() succeeds: |
| 323 | * |
| 324 | * If the output device equals the logical bridge device the packet |
| 325 | * came in on, we can consider this bridging. The corresponding MAC |
| 326 | * address will be obtained in br_nf_pre_routing_finish_bridge. |
| 327 | * Otherwise, the packet is considered to be routed and we just |
| 328 | * change the destination MAC address so that the packet will |
| 329 | * later be passed up to the IP stack to be routed. For a redirected |
| 330 | * packet, ip_route_input() will give back the localhost as output device, |
| 331 | * which differs from the bridge device. |
| 332 | * |
| 333 | * Let's now consider the case that ip_route_input() fails: |
| 334 | * |
| 335 | * This can be because the destination address is martian, in which case |
| 336 | * the packet will be dropped. |
| 337 | * If IP forwarding is disabled, ip_route_input() will fail, while |
| 338 | * ip_route_output_key() can return success. The source |
| 339 | * address for ip_route_output_key() is set to zero, so ip_route_output_key() |
| 340 | * thinks we're handling a locally generated packet and won't care |
| 341 | * if IP forwarding is enabled. If the output device equals the logical bridge |
| 342 | * device, we proceed as if ip_route_input() succeeded. If it differs from the |
| 343 | * logical bridge port or if ip_route_output_key() fails we drop the packet. |
| 344 | */ |
| 345 | static int br_nf_pre_routing_finish(struct sock *sk, struct sk_buff *skb) |
| 346 | { |
| 347 | struct net_device *dev = skb->dev; |
| 348 | struct iphdr *iph = ip_hdr(skb); |
| 349 | struct net *net = dev_net(dev); |
| 350 | struct nf_bridge_info *nf_bridge = nf_bridge_info_get(skb); |
| 351 | struct rtable *rt; |
| 352 | int err; |
| 353 | |
| 354 | nf_bridge->frag_max_size = IPCB(skb)->frag_max_size; |
| 355 | |
| 356 | if (nf_bridge->pkt_otherhost) { |
| 357 | skb->pkt_type = PACKET_OTHERHOST; |
| 358 | nf_bridge->pkt_otherhost = false; |
| 359 | } |
| 360 | nf_bridge->in_prerouting = 0; |
| 361 | if (br_nf_ipv4_daddr_was_changed(skb, nf_bridge)) { |
| 362 | if ((err = ip_route_input(skb, iph->daddr, iph->saddr, iph->tos, dev))) { |
| 363 | struct in_device *in_dev = __in_dev_get_rcu(dev); |
| 364 | |
| 365 | /* If err equals -EHOSTUNREACH the error is due to a |
| 366 | * martian destination or due to the fact that |
| 367 | * forwarding is disabled. For most martian packets, |
| 368 | * ip_route_output_key() will fail. It won't fail for 2 types of |
| 369 | * martian destinations: loopback destinations and destination |
| 370 | * 0.0.0.0. In both cases the packet will be dropped because the |
| 371 | * destination is the loopback device and not the bridge. */ |
| 372 | if (err != -EHOSTUNREACH || !in_dev || IN_DEV_FORWARD(in_dev)) |
| 373 | goto free_skb; |
| 374 | |
| 375 | rt = ip_route_output(net, iph->daddr, 0, |
| 376 | RT_TOS(iph->tos), 0); |
| 377 | if (!IS_ERR(rt)) { |
| 378 | /* - Bridged-and-DNAT'ed traffic doesn't |
| 379 | * require ip_forwarding. */ |
| 380 | if (rt->dst.dev == dev) { |
| 381 | skb_dst_set(skb, &rt->dst); |
| 382 | goto bridged_dnat; |
| 383 | } |
| 384 | ip_rt_put(rt); |
| 385 | } |
| 386 | free_skb: |
| 387 | kfree_skb(skb); |
| 388 | return 0; |
| 389 | } else { |
| 390 | if (skb_dst(skb)->dev == dev) { |
| 391 | bridged_dnat: |
| 392 | skb->dev = nf_bridge->physindev; |
| 393 | nf_bridge_update_protocol(skb); |
| 394 | nf_bridge_push_encap_header(skb); |
| 395 | NF_HOOK_THRESH(NFPROTO_BRIDGE, |
| 396 | NF_BR_PRE_ROUTING, |
| 397 | sk, skb, skb->dev, NULL, |
| 398 | br_nf_pre_routing_finish_bridge, |
| 399 | 1); |
| 400 | return 0; |
| 401 | } |
| 402 | ether_addr_copy(eth_hdr(skb)->h_dest, dev->dev_addr); |
| 403 | skb->pkt_type = PACKET_HOST; |
| 404 | } |
| 405 | } else { |
| 406 | rt = bridge_parent_rtable(nf_bridge->physindev); |
| 407 | if (!rt) { |
| 408 | kfree_skb(skb); |
| 409 | return 0; |
| 410 | } |
| 411 | skb_dst_set_noref(skb, &rt->dst); |
| 412 | } |
| 413 | |
| 414 | skb->dev = nf_bridge->physindev; |
| 415 | nf_bridge_update_protocol(skb); |
| 416 | nf_bridge_push_encap_header(skb); |
| 417 | NF_HOOK_THRESH(NFPROTO_BRIDGE, NF_BR_PRE_ROUTING, sk, skb, |
| 418 | skb->dev, NULL, |
| 419 | br_handle_frame_finish, 1); |
| 420 | |
| 421 | return 0; |
| 422 | } |
| 423 | |
| 424 | static struct net_device *brnf_get_logical_dev(struct sk_buff *skb, const struct net_device *dev) |
| 425 | { |
| 426 | struct net_device *vlan, *br; |
| 427 | |
| 428 | br = bridge_parent(dev); |
| 429 | if (brnf_pass_vlan_indev == 0 || !skb_vlan_tag_present(skb)) |
| 430 | return br; |
| 431 | |
| 432 | vlan = __vlan_find_dev_deep_rcu(br, skb->vlan_proto, |
| 433 | skb_vlan_tag_get(skb) & VLAN_VID_MASK); |
| 434 | |
| 435 | return vlan ? vlan : br; |
| 436 | } |
| 437 | |
| 438 | /* Some common code for IPv4/IPv6 */ |
| 439 | struct net_device *setup_pre_routing(struct sk_buff *skb) |
| 440 | { |
| 441 | struct nf_bridge_info *nf_bridge = nf_bridge_info_get(skb); |
| 442 | |
| 443 | if (skb->pkt_type == PACKET_OTHERHOST) { |
| 444 | skb->pkt_type = PACKET_HOST; |
| 445 | nf_bridge->pkt_otherhost = true; |
| 446 | } |
| 447 | |
| 448 | nf_bridge->in_prerouting = 1; |
| 449 | nf_bridge->physindev = skb->dev; |
| 450 | skb->dev = brnf_get_logical_dev(skb, skb->dev); |
| 451 | |
| 452 | if (skb->protocol == htons(ETH_P_8021Q)) |
| 453 | nf_bridge->orig_proto = BRNF_PROTO_8021Q; |
| 454 | else if (skb->protocol == htons(ETH_P_PPP_SES)) |
| 455 | nf_bridge->orig_proto = BRNF_PROTO_PPPOE; |
| 456 | |
| 457 | /* Must drop socket now because of tproxy. */ |
| 458 | skb_orphan(skb); |
| 459 | return skb->dev; |
| 460 | } |
| 461 | |
| 462 | /* Direct IPv6 traffic to br_nf_pre_routing_ipv6. |
| 463 | * Replicate the checks that IPv4 does on packet reception. |
| 464 | * Set skb->dev to the bridge device (i.e. parent of the |
| 465 | * receiving device) to make netfilter happy, the REDIRECT |
| 466 | * target in particular. Save the original destination IP |
| 467 | * address to be able to detect DNAT afterwards. */ |
| 468 | static unsigned int br_nf_pre_routing(const struct nf_hook_ops *ops, |
| 469 | struct sk_buff *skb, |
| 470 | const struct nf_hook_state *state) |
| 471 | { |
| 472 | struct nf_bridge_info *nf_bridge; |
| 473 | struct net_bridge_port *p; |
| 474 | struct net_bridge *br; |
| 475 | __u32 len = nf_bridge_encap_header_len(skb); |
| 476 | |
| 477 | if (unlikely(!pskb_may_pull(skb, len))) |
| 478 | return NF_DROP; |
| 479 | |
| 480 | p = br_port_get_rcu(state->in); |
| 481 | if (p == NULL) |
| 482 | return NF_DROP; |
| 483 | br = p->br; |
| 484 | |
| 485 | if (IS_IPV6(skb) || IS_VLAN_IPV6(skb) || IS_PPPOE_IPV6(skb)) { |
| 486 | if (!brnf_call_ip6tables && !br->nf_call_ip6tables) |
| 487 | return NF_ACCEPT; |
| 488 | |
| 489 | nf_bridge_pull_encap_header_rcsum(skb); |
| 490 | return br_nf_pre_routing_ipv6(ops, skb, state); |
| 491 | } |
| 492 | |
| 493 | if (!brnf_call_iptables && !br->nf_call_iptables) |
| 494 | return NF_ACCEPT; |
| 495 | |
| 496 | if (!IS_IP(skb) && !IS_VLAN_IP(skb) && !IS_PPPOE_IP(skb)) |
| 497 | return NF_ACCEPT; |
| 498 | |
| 499 | nf_bridge_pull_encap_header_rcsum(skb); |
| 500 | |
| 501 | if (br_validate_ipv4(skb)) |
| 502 | return NF_DROP; |
| 503 | |
| 504 | nf_bridge_put(skb->nf_bridge); |
| 505 | if (!nf_bridge_alloc(skb)) |
| 506 | return NF_DROP; |
| 507 | if (!setup_pre_routing(skb)) |
| 508 | return NF_DROP; |
| 509 | |
| 510 | nf_bridge = nf_bridge_info_get(skb); |
| 511 | nf_bridge->ipv4_daddr = ip_hdr(skb)->daddr; |
| 512 | |
| 513 | skb->protocol = htons(ETH_P_IP); |
| 514 | |
| 515 | NF_HOOK(NFPROTO_IPV4, NF_INET_PRE_ROUTING, state->sk, skb, |
| 516 | skb->dev, NULL, |
| 517 | br_nf_pre_routing_finish); |
| 518 | |
| 519 | return NF_STOLEN; |
| 520 | } |
| 521 | |
| 522 | |
| 523 | /* PF_BRIDGE/LOCAL_IN ************************************************/ |
| 524 | /* The packet is locally destined, which requires a real |
| 525 | * dst_entry, so detach the fake one. On the way up, the |
| 526 | * packet would pass through PRE_ROUTING again (which already |
| 527 | * took place when the packet entered the bridge), but we |
| 528 | * register an IPv4 PRE_ROUTING 'sabotage' hook that will |
| 529 | * prevent this from happening. */ |
| 530 | static unsigned int br_nf_local_in(const struct nf_hook_ops *ops, |
| 531 | struct sk_buff *skb, |
| 532 | const struct nf_hook_state *state) |
| 533 | { |
| 534 | br_drop_fake_rtable(skb); |
| 535 | return NF_ACCEPT; |
| 536 | } |
| 537 | |
| 538 | /* PF_BRIDGE/FORWARD *************************************************/ |
| 539 | static int br_nf_forward_finish(struct sock *sk, struct sk_buff *skb) |
| 540 | { |
| 541 | struct nf_bridge_info *nf_bridge = nf_bridge_info_get(skb); |
| 542 | struct net_device *in; |
| 543 | |
| 544 | if (!IS_ARP(skb) && !IS_VLAN_ARP(skb)) { |
| 545 | |
| 546 | if (skb->protocol == htons(ETH_P_IP)) |
| 547 | nf_bridge->frag_max_size = IPCB(skb)->frag_max_size; |
| 548 | |
| 549 | if (skb->protocol == htons(ETH_P_IPV6)) |
| 550 | nf_bridge->frag_max_size = IP6CB(skb)->frag_max_size; |
| 551 | |
| 552 | in = nf_bridge->physindev; |
| 553 | if (nf_bridge->pkt_otherhost) { |
| 554 | skb->pkt_type = PACKET_OTHERHOST; |
| 555 | nf_bridge->pkt_otherhost = false; |
| 556 | } |
| 557 | nf_bridge_update_protocol(skb); |
| 558 | } else { |
| 559 | in = *((struct net_device **)(skb->cb)); |
| 560 | } |
| 561 | nf_bridge_push_encap_header(skb); |
| 562 | |
| 563 | NF_HOOK_THRESH(NFPROTO_BRIDGE, NF_BR_FORWARD, sk, skb, |
| 564 | in, skb->dev, br_forward_finish, 1); |
| 565 | return 0; |
| 566 | } |
| 567 | |
| 568 | |
| 569 | /* This is the 'purely bridged' case. For IP, we pass the packet to |
| 570 | * netfilter with indev and outdev set to the bridge device, |
| 571 | * but we are still able to filter on the 'real' indev/outdev |
| 572 | * because of the physdev module. For ARP, indev and outdev are the |
| 573 | * bridge ports. */ |
| 574 | static unsigned int br_nf_forward_ip(const struct nf_hook_ops *ops, |
| 575 | struct sk_buff *skb, |
| 576 | const struct nf_hook_state *state) |
| 577 | { |
| 578 | struct nf_bridge_info *nf_bridge; |
| 579 | struct net_device *parent; |
| 580 | u_int8_t pf; |
| 581 | |
| 582 | if (!skb->nf_bridge) |
| 583 | return NF_ACCEPT; |
| 584 | |
| 585 | /* Need exclusive nf_bridge_info since we might have multiple |
| 586 | * different physoutdevs. */ |
| 587 | if (!nf_bridge_unshare(skb)) |
| 588 | return NF_DROP; |
| 589 | |
| 590 | nf_bridge = nf_bridge_info_get(skb); |
| 591 | if (!nf_bridge) |
| 592 | return NF_DROP; |
| 593 | |
| 594 | parent = bridge_parent(state->out); |
| 595 | if (!parent) |
| 596 | return NF_DROP; |
| 597 | |
| 598 | if (IS_IP(skb) || IS_VLAN_IP(skb) || IS_PPPOE_IP(skb)) |
| 599 | pf = NFPROTO_IPV4; |
| 600 | else if (IS_IPV6(skb) || IS_VLAN_IPV6(skb) || IS_PPPOE_IPV6(skb)) |
| 601 | pf = NFPROTO_IPV6; |
| 602 | else |
| 603 | return NF_ACCEPT; |
| 604 | |
| 605 | nf_bridge_pull_encap_header(skb); |
| 606 | |
| 607 | if (skb->pkt_type == PACKET_OTHERHOST) { |
| 608 | skb->pkt_type = PACKET_HOST; |
| 609 | nf_bridge->pkt_otherhost = true; |
| 610 | } |
| 611 | |
| 612 | if (pf == NFPROTO_IPV4) { |
| 613 | if (br_validate_ipv4(skb)) |
| 614 | return NF_DROP; |
| 615 | IPCB(skb)->frag_max_size = nf_bridge->frag_max_size; |
| 616 | } |
| 617 | |
| 618 | if (pf == NFPROTO_IPV6) { |
| 619 | if (br_validate_ipv6(skb)) |
| 620 | return NF_DROP; |
| 621 | IP6CB(skb)->frag_max_size = nf_bridge->frag_max_size; |
| 622 | } |
| 623 | |
| 624 | nf_bridge->physoutdev = skb->dev; |
| 625 | if (pf == NFPROTO_IPV4) |
| 626 | skb->protocol = htons(ETH_P_IP); |
| 627 | else |
| 628 | skb->protocol = htons(ETH_P_IPV6); |
| 629 | |
| 630 | NF_HOOK(pf, NF_INET_FORWARD, NULL, skb, |
| 631 | brnf_get_logical_dev(skb, state->in), |
| 632 | parent, br_nf_forward_finish); |
| 633 | |
| 634 | return NF_STOLEN; |
| 635 | } |
| 636 | |
| 637 | static unsigned int br_nf_forward_arp(const struct nf_hook_ops *ops, |
| 638 | struct sk_buff *skb, |
| 639 | const struct nf_hook_state *state) |
| 640 | { |
| 641 | struct net_bridge_port *p; |
| 642 | struct net_bridge *br; |
| 643 | struct net_device **d = (struct net_device **)(skb->cb); |
| 644 | |
| 645 | p = br_port_get_rcu(state->out); |
| 646 | if (p == NULL) |
| 647 | return NF_ACCEPT; |
| 648 | br = p->br; |
| 649 | |
| 650 | if (!brnf_call_arptables && !br->nf_call_arptables) |
| 651 | return NF_ACCEPT; |
| 652 | |
| 653 | if (!IS_ARP(skb)) { |
| 654 | if (!IS_VLAN_ARP(skb)) |
| 655 | return NF_ACCEPT; |
| 656 | nf_bridge_pull_encap_header(skb); |
| 657 | } |
| 658 | |
| 659 | if (arp_hdr(skb)->ar_pln != 4) { |
| 660 | if (IS_VLAN_ARP(skb)) |
| 661 | nf_bridge_push_encap_header(skb); |
| 662 | return NF_ACCEPT; |
| 663 | } |
| 664 | *d = state->in; |
| 665 | NF_HOOK(NFPROTO_ARP, NF_ARP_FORWARD, state->sk, skb, |
| 666 | state->in, state->out, br_nf_forward_finish); |
| 667 | |
| 668 | return NF_STOLEN; |
| 669 | } |
| 670 | |
| 671 | #if IS_ENABLED(CONFIG_NF_DEFRAG_IPV4) || IS_ENABLED(CONFIG_NF_DEFRAG_IPV6) |
| 672 | static int br_nf_push_frag_xmit(struct net *net, struct sock *sk, struct sk_buff *skb) |
| 673 | { |
| 674 | struct brnf_frag_data *data; |
| 675 | int err; |
| 676 | |
| 677 | data = this_cpu_ptr(&brnf_frag_data_storage); |
| 678 | err = skb_cow_head(skb, data->size); |
| 679 | |
| 680 | if (err) { |
| 681 | kfree_skb(skb); |
| 682 | return 0; |
| 683 | } |
| 684 | |
| 685 | if (data->vlan_tci) { |
| 686 | skb->vlan_tci = data->vlan_tci; |
| 687 | skb->vlan_proto = data->vlan_proto; |
| 688 | } |
| 689 | |
| 690 | skb_copy_to_linear_data_offset(skb, -data->size, data->mac, data->size); |
| 691 | __skb_push(skb, data->encap_size); |
| 692 | |
| 693 | nf_bridge_info_free(skb); |
| 694 | return br_dev_queue_push_xmit(sk, skb); |
| 695 | } |
| 696 | static int br_nf_push_frag_xmit_sk(struct sock *sk, struct sk_buff *skb) |
| 697 | { |
| 698 | struct net *net = dev_net(skb_dst(skb)->dev); |
| 699 | return br_nf_push_frag_xmit(net, sk, skb); |
| 700 | } |
| 701 | #endif |
| 702 | |
| 703 | #if IS_ENABLED(CONFIG_NF_DEFRAG_IPV4) |
| 704 | static int |
| 705 | br_nf_ip_fragment(struct net *net, struct sock *sk, struct sk_buff *skb, |
| 706 | int (*output)(struct sock *, struct sk_buff *)) |
| 707 | { |
| 708 | unsigned int mtu = ip_skb_dst_mtu(skb); |
| 709 | struct iphdr *iph = ip_hdr(skb); |
| 710 | |
| 711 | if (unlikely(((iph->frag_off & htons(IP_DF)) && !skb->ignore_df) || |
| 712 | (IPCB(skb)->frag_max_size && |
| 713 | IPCB(skb)->frag_max_size > mtu))) { |
| 714 | IP_INC_STATS(net, IPSTATS_MIB_FRAGFAILS); |
| 715 | kfree_skb(skb); |
| 716 | return -EMSGSIZE; |
| 717 | } |
| 718 | |
| 719 | return ip_do_fragment(sk, skb, output); |
| 720 | } |
| 721 | #endif |
| 722 | |
| 723 | static unsigned int nf_bridge_mtu_reduction(const struct sk_buff *skb) |
| 724 | { |
| 725 | if (skb->nf_bridge->orig_proto == BRNF_PROTO_PPPOE) |
| 726 | return PPPOE_SES_HLEN; |
| 727 | return 0; |
| 728 | } |
| 729 | |
| 730 | static int br_nf_dev_queue_xmit(struct sock *sk, struct sk_buff *skb) |
| 731 | { |
| 732 | struct nf_bridge_info *nf_bridge; |
| 733 | unsigned int mtu_reserved; |
| 734 | struct net *net = dev_net(skb_dst(skb)->dev); |
| 735 | |
| 736 | mtu_reserved = nf_bridge_mtu_reduction(skb); |
| 737 | |
| 738 | if (skb_is_gso(skb) || skb->len + mtu_reserved <= skb->dev->mtu) { |
| 739 | nf_bridge_info_free(skb); |
| 740 | return br_dev_queue_push_xmit(sk, skb); |
| 741 | } |
| 742 | |
| 743 | nf_bridge = nf_bridge_info_get(skb); |
| 744 | |
| 745 | #if IS_ENABLED(CONFIG_NF_DEFRAG_IPV4) |
| 746 | /* This is wrong! We should preserve the original fragment |
| 747 | * boundaries by preserving frag_list rather than refragmenting. |
| 748 | */ |
| 749 | if (skb->protocol == htons(ETH_P_IP)) { |
| 750 | struct brnf_frag_data *data; |
| 751 | |
| 752 | if (br_validate_ipv4(skb)) |
| 753 | goto drop; |
| 754 | |
| 755 | IPCB(skb)->frag_max_size = nf_bridge->frag_max_size; |
| 756 | |
| 757 | nf_bridge_update_protocol(skb); |
| 758 | |
| 759 | data = this_cpu_ptr(&brnf_frag_data_storage); |
| 760 | |
| 761 | data->vlan_tci = skb->vlan_tci; |
| 762 | data->vlan_proto = skb->vlan_proto; |
| 763 | data->encap_size = nf_bridge_encap_header_len(skb); |
| 764 | data->size = ETH_HLEN + data->encap_size; |
| 765 | |
| 766 | skb_copy_from_linear_data_offset(skb, -data->size, data->mac, |
| 767 | data->size); |
| 768 | |
| 769 | return br_nf_ip_fragment(net, sk, skb, br_nf_push_frag_xmit_sk); |
| 770 | } |
| 771 | #endif |
| 772 | #if IS_ENABLED(CONFIG_NF_DEFRAG_IPV6) |
| 773 | if (skb->protocol == htons(ETH_P_IPV6)) { |
| 774 | const struct nf_ipv6_ops *v6ops = nf_get_ipv6_ops(); |
| 775 | struct brnf_frag_data *data; |
| 776 | |
| 777 | if (br_validate_ipv6(skb)) |
| 778 | goto drop; |
| 779 | |
| 780 | IP6CB(skb)->frag_max_size = nf_bridge->frag_max_size; |
| 781 | |
| 782 | nf_bridge_update_protocol(skb); |
| 783 | |
| 784 | data = this_cpu_ptr(&brnf_frag_data_storage); |
| 785 | data->encap_size = nf_bridge_encap_header_len(skb); |
| 786 | data->size = ETH_HLEN + data->encap_size; |
| 787 | |
| 788 | skb_copy_from_linear_data_offset(skb, -data->size, data->mac, |
| 789 | data->size); |
| 790 | |
| 791 | if (v6ops) |
| 792 | return v6ops->fragment(sk, skb, br_nf_push_frag_xmit_sk); |
| 793 | |
| 794 | kfree_skb(skb); |
| 795 | return -EMSGSIZE; |
| 796 | } |
| 797 | #endif |
| 798 | nf_bridge_info_free(skb); |
| 799 | return br_dev_queue_push_xmit(sk, skb); |
| 800 | drop: |
| 801 | kfree_skb(skb); |
| 802 | return 0; |
| 803 | } |
| 804 | |
| 805 | /* PF_BRIDGE/POST_ROUTING ********************************************/ |
| 806 | static unsigned int br_nf_post_routing(const struct nf_hook_ops *ops, |
| 807 | struct sk_buff *skb, |
| 808 | const struct nf_hook_state *state) |
| 809 | { |
| 810 | struct nf_bridge_info *nf_bridge = nf_bridge_info_get(skb); |
| 811 | struct net_device *realoutdev = bridge_parent(skb->dev); |
| 812 | u_int8_t pf; |
| 813 | |
| 814 | /* if nf_bridge is set, but ->physoutdev is NULL, this packet came in |
| 815 | * on a bridge, but was delivered locally and is now being routed: |
| 816 | * |
| 817 | * POST_ROUTING was already invoked from the ip stack. |
| 818 | */ |
| 819 | if (!nf_bridge || !nf_bridge->physoutdev) |
| 820 | return NF_ACCEPT; |
| 821 | |
| 822 | if (!realoutdev) |
| 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 | /* We assume any code from br_dev_queue_push_xmit onwards doesn't care |
| 833 | * about the value of skb->pkt_type. */ |
| 834 | if (skb->pkt_type == PACKET_OTHERHOST) { |
| 835 | skb->pkt_type = PACKET_HOST; |
| 836 | nf_bridge->pkt_otherhost = true; |
| 837 | } |
| 838 | |
| 839 | nf_bridge_pull_encap_header(skb); |
| 840 | if (pf == NFPROTO_IPV4) |
| 841 | skb->protocol = htons(ETH_P_IP); |
| 842 | else |
| 843 | skb->protocol = htons(ETH_P_IPV6); |
| 844 | |
| 845 | NF_HOOK(pf, NF_INET_POST_ROUTING, state->sk, skb, |
| 846 | NULL, realoutdev, |
| 847 | br_nf_dev_queue_xmit); |
| 848 | |
| 849 | return NF_STOLEN; |
| 850 | } |
| 851 | |
| 852 | /* IP/SABOTAGE *****************************************************/ |
| 853 | /* Don't hand locally destined packets to PF_INET(6)/PRE_ROUTING |
| 854 | * for the second time. */ |
| 855 | static unsigned int ip_sabotage_in(const struct nf_hook_ops *ops, |
| 856 | struct sk_buff *skb, |
| 857 | const struct nf_hook_state *state) |
| 858 | { |
| 859 | if (skb->nf_bridge && !skb->nf_bridge->in_prerouting) |
| 860 | return NF_STOP; |
| 861 | |
| 862 | return NF_ACCEPT; |
| 863 | } |
| 864 | |
| 865 | /* This is called when br_netfilter has called into iptables/netfilter, |
| 866 | * and DNAT has taken place on a bridge-forwarded packet. |
| 867 | * |
| 868 | * neigh->output has created a new MAC header, with local br0 MAC |
| 869 | * as saddr. |
| 870 | * |
| 871 | * This restores the original MAC saddr of the bridged packet |
| 872 | * before invoking bridge forward logic to transmit the packet. |
| 873 | */ |
| 874 | static void br_nf_pre_routing_finish_bridge_slow(struct sk_buff *skb) |
| 875 | { |
| 876 | struct nf_bridge_info *nf_bridge = nf_bridge_info_get(skb); |
| 877 | |
| 878 | skb_pull(skb, ETH_HLEN); |
| 879 | nf_bridge->bridged_dnat = 0; |
| 880 | |
| 881 | BUILD_BUG_ON(sizeof(nf_bridge->neigh_header) != (ETH_HLEN - ETH_ALEN)); |
| 882 | |
| 883 | skb_copy_to_linear_data_offset(skb, -(ETH_HLEN - ETH_ALEN), |
| 884 | nf_bridge->neigh_header, |
| 885 | ETH_HLEN - ETH_ALEN); |
| 886 | skb->dev = nf_bridge->physindev; |
| 887 | |
| 888 | nf_bridge->physoutdev = NULL; |
| 889 | br_handle_frame_finish(NULL, skb); |
| 890 | } |
| 891 | |
| 892 | static int br_nf_dev_xmit(struct sk_buff *skb) |
| 893 | { |
| 894 | if (skb->nf_bridge && skb->nf_bridge->bridged_dnat) { |
| 895 | br_nf_pre_routing_finish_bridge_slow(skb); |
| 896 | return 1; |
| 897 | } |
| 898 | return 0; |
| 899 | } |
| 900 | |
| 901 | static const struct nf_br_ops br_ops = { |
| 902 | .br_dev_xmit_hook = br_nf_dev_xmit, |
| 903 | }; |
| 904 | |
| 905 | void br_netfilter_enable(void) |
| 906 | { |
| 907 | } |
| 908 | EXPORT_SYMBOL_GPL(br_netfilter_enable); |
| 909 | |
| 910 | /* For br_nf_post_routing, we need (prio = NF_BR_PRI_LAST), because |
| 911 | * br_dev_queue_push_xmit is called afterwards */ |
| 912 | static struct nf_hook_ops br_nf_ops[] __read_mostly = { |
| 913 | { |
| 914 | .hook = br_nf_pre_routing, |
| 915 | .owner = THIS_MODULE, |
| 916 | .pf = NFPROTO_BRIDGE, |
| 917 | .hooknum = NF_BR_PRE_ROUTING, |
| 918 | .priority = NF_BR_PRI_BRNF, |
| 919 | }, |
| 920 | { |
| 921 | .hook = br_nf_local_in, |
| 922 | .owner = THIS_MODULE, |
| 923 | .pf = NFPROTO_BRIDGE, |
| 924 | .hooknum = NF_BR_LOCAL_IN, |
| 925 | .priority = NF_BR_PRI_BRNF, |
| 926 | }, |
| 927 | { |
| 928 | .hook = br_nf_forward_ip, |
| 929 | .owner = THIS_MODULE, |
| 930 | .pf = NFPROTO_BRIDGE, |
| 931 | .hooknum = NF_BR_FORWARD, |
| 932 | .priority = NF_BR_PRI_BRNF - 1, |
| 933 | }, |
| 934 | { |
| 935 | .hook = br_nf_forward_arp, |
| 936 | .owner = THIS_MODULE, |
| 937 | .pf = NFPROTO_BRIDGE, |
| 938 | .hooknum = NF_BR_FORWARD, |
| 939 | .priority = NF_BR_PRI_BRNF, |
| 940 | }, |
| 941 | { |
| 942 | .hook = br_nf_post_routing, |
| 943 | .owner = THIS_MODULE, |
| 944 | .pf = NFPROTO_BRIDGE, |
| 945 | .hooknum = NF_BR_POST_ROUTING, |
| 946 | .priority = NF_BR_PRI_LAST, |
| 947 | }, |
| 948 | { |
| 949 | .hook = ip_sabotage_in, |
| 950 | .owner = THIS_MODULE, |
| 951 | .pf = NFPROTO_IPV4, |
| 952 | .hooknum = NF_INET_PRE_ROUTING, |
| 953 | .priority = NF_IP_PRI_FIRST, |
| 954 | }, |
| 955 | { |
| 956 | .hook = ip_sabotage_in, |
| 957 | .owner = THIS_MODULE, |
| 958 | .pf = NFPROTO_IPV6, |
| 959 | .hooknum = NF_INET_PRE_ROUTING, |
| 960 | .priority = NF_IP6_PRI_FIRST, |
| 961 | }, |
| 962 | }; |
| 963 | |
| 964 | #ifdef CONFIG_SYSCTL |
| 965 | static |
| 966 | int brnf_sysctl_call_tables(struct ctl_table *ctl, int write, |
| 967 | void __user *buffer, size_t *lenp, loff_t *ppos) |
| 968 | { |
| 969 | int ret; |
| 970 | |
| 971 | ret = proc_dointvec(ctl, write, buffer, lenp, ppos); |
| 972 | |
| 973 | if (write && *(int *)(ctl->data)) |
| 974 | *(int *)(ctl->data) = 1; |
| 975 | return ret; |
| 976 | } |
| 977 | |
| 978 | static struct ctl_table brnf_table[] = { |
| 979 | { |
| 980 | .procname = "bridge-nf-call-arptables", |
| 981 | .data = &brnf_call_arptables, |
| 982 | .maxlen = sizeof(int), |
| 983 | .mode = 0644, |
| 984 | .proc_handler = brnf_sysctl_call_tables, |
| 985 | }, |
| 986 | { |
| 987 | .procname = "bridge-nf-call-iptables", |
| 988 | .data = &brnf_call_iptables, |
| 989 | .maxlen = sizeof(int), |
| 990 | .mode = 0644, |
| 991 | .proc_handler = brnf_sysctl_call_tables, |
| 992 | }, |
| 993 | { |
| 994 | .procname = "bridge-nf-call-ip6tables", |
| 995 | .data = &brnf_call_ip6tables, |
| 996 | .maxlen = sizeof(int), |
| 997 | .mode = 0644, |
| 998 | .proc_handler = brnf_sysctl_call_tables, |
| 999 | }, |
| 1000 | { |
| 1001 | .procname = "bridge-nf-filter-vlan-tagged", |
| 1002 | .data = &brnf_filter_vlan_tagged, |
| 1003 | .maxlen = sizeof(int), |
| 1004 | .mode = 0644, |
| 1005 | .proc_handler = brnf_sysctl_call_tables, |
| 1006 | }, |
| 1007 | { |
| 1008 | .procname = "bridge-nf-filter-pppoe-tagged", |
| 1009 | .data = &brnf_filter_pppoe_tagged, |
| 1010 | .maxlen = sizeof(int), |
| 1011 | .mode = 0644, |
| 1012 | .proc_handler = brnf_sysctl_call_tables, |
| 1013 | }, |
| 1014 | { |
| 1015 | .procname = "bridge-nf-pass-vlan-input-dev", |
| 1016 | .data = &brnf_pass_vlan_indev, |
| 1017 | .maxlen = sizeof(int), |
| 1018 | .mode = 0644, |
| 1019 | .proc_handler = brnf_sysctl_call_tables, |
| 1020 | }, |
| 1021 | { } |
| 1022 | }; |
| 1023 | #endif |
| 1024 | |
| 1025 | static int __init br_netfilter_init(void) |
| 1026 | { |
| 1027 | int ret; |
| 1028 | |
| 1029 | ret = nf_register_hooks(br_nf_ops, ARRAY_SIZE(br_nf_ops)); |
| 1030 | if (ret < 0) |
| 1031 | return ret; |
| 1032 | |
| 1033 | #ifdef CONFIG_SYSCTL |
| 1034 | brnf_sysctl_header = register_net_sysctl(&init_net, "net/bridge", brnf_table); |
| 1035 | if (brnf_sysctl_header == NULL) { |
| 1036 | printk(KERN_WARNING |
| 1037 | "br_netfilter: can't register to sysctl.\n"); |
| 1038 | nf_unregister_hooks(br_nf_ops, ARRAY_SIZE(br_nf_ops)); |
| 1039 | return -ENOMEM; |
| 1040 | } |
| 1041 | #endif |
| 1042 | RCU_INIT_POINTER(nf_br_ops, &br_ops); |
| 1043 | printk(KERN_NOTICE "Bridge firewalling registered\n"); |
| 1044 | return 0; |
| 1045 | } |
| 1046 | |
| 1047 | static void __exit br_netfilter_fini(void) |
| 1048 | { |
| 1049 | RCU_INIT_POINTER(nf_br_ops, NULL); |
| 1050 | nf_unregister_hooks(br_nf_ops, ARRAY_SIZE(br_nf_ops)); |
| 1051 | #ifdef CONFIG_SYSCTL |
| 1052 | unregister_net_sysctl_table(brnf_sysctl_header); |
| 1053 | #endif |
| 1054 | } |
| 1055 | |
| 1056 | module_init(br_netfilter_init); |
| 1057 | module_exit(br_netfilter_fini); |
| 1058 | |
| 1059 | MODULE_LICENSE("GPL"); |
| 1060 | MODULE_AUTHOR("Lennert Buytenhek <buytenh@gnu.org>"); |
| 1061 | MODULE_AUTHOR("Bart De Schuymer <bdschuym@pandora.be>"); |
| 1062 | MODULE_DESCRIPTION("Linux ethernet netfilter firewall bridge"); |