Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * INET An implementation of the TCP/IP protocol suite for the LINUX |
| 3 | * operating system. INET is implemented using the BSD Socket |
| 4 | * interface as the means of communication with the user level. |
| 5 | * |
| 6 | * The Internet Protocol (IP) module. |
| 7 | * |
| 8 | * Version: $Id: ip_input.c,v 1.55 2002/01/12 07:39:45 davem Exp $ |
| 9 | * |
Jesper Juhl | 02c30a8 | 2005-05-05 16:16:16 -0700 | [diff] [blame] | 10 | * Authors: Ross Biro |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 11 | * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> |
| 12 | * Donald Becker, <becker@super.org> |
| 13 | * Alan Cox, <Alan.Cox@linux.org> |
| 14 | * Richard Underwood |
| 15 | * Stefan Becker, <stefanb@yello.ping.de> |
| 16 | * Jorge Cwik, <jorge@laser.satlink.net> |
| 17 | * Arnt Gulbrandsen, <agulbra@nvg.unit.no> |
| 18 | * |
| 19 | * |
| 20 | * Fixes: |
| 21 | * Alan Cox : Commented a couple of minor bits of surplus code |
| 22 | * Alan Cox : Undefining IP_FORWARD doesn't include the code |
| 23 | * (just stops a compiler warning). |
| 24 | * Alan Cox : Frames with >=MAX_ROUTE record routes, strict routes or loose routes |
| 25 | * are junked rather than corrupting things. |
| 26 | * Alan Cox : Frames to bad broadcast subnets are dumped |
| 27 | * We used to process them non broadcast and |
| 28 | * boy could that cause havoc. |
| 29 | * Alan Cox : ip_forward sets the free flag on the |
| 30 | * new frame it queues. Still crap because |
| 31 | * it copies the frame but at least it |
| 32 | * doesn't eat memory too. |
| 33 | * Alan Cox : Generic queue code and memory fixes. |
| 34 | * Fred Van Kempen : IP fragment support (borrowed from NET2E) |
| 35 | * Gerhard Koerting: Forward fragmented frames correctly. |
| 36 | * Gerhard Koerting: Fixes to my fix of the above 8-). |
| 37 | * Gerhard Koerting: IP interface addressing fix. |
| 38 | * Linus Torvalds : More robustness checks |
| 39 | * Alan Cox : Even more checks: Still not as robust as it ought to be |
| 40 | * Alan Cox : Save IP header pointer for later |
| 41 | * Alan Cox : ip option setting |
| 42 | * Alan Cox : Use ip_tos/ip_ttl settings |
| 43 | * Alan Cox : Fragmentation bogosity removed |
| 44 | * (Thanks to Mark.Bush@prg.ox.ac.uk) |
| 45 | * Dmitry Gorodchanin : Send of a raw packet crash fix. |
| 46 | * Alan Cox : Silly ip bug when an overlength |
| 47 | * fragment turns up. Now frees the |
| 48 | * queue. |
| 49 | * Linus Torvalds/ : Memory leakage on fragmentation |
| 50 | * Alan Cox : handling. |
| 51 | * Gerhard Koerting: Forwarding uses IP priority hints |
| 52 | * Teemu Rantanen : Fragment problems. |
| 53 | * Alan Cox : General cleanup, comments and reformat |
| 54 | * Alan Cox : SNMP statistics |
| 55 | * Alan Cox : BSD address rule semantics. Also see |
| 56 | * UDP as there is a nasty checksum issue |
| 57 | * if you do things the wrong way. |
| 58 | * Alan Cox : Always defrag, moved IP_FORWARD to the config.in file |
| 59 | * Alan Cox : IP options adjust sk->priority. |
| 60 | * Pedro Roque : Fix mtu/length error in ip_forward. |
| 61 | * Alan Cox : Avoid ip_chk_addr when possible. |
| 62 | * Richard Underwood : IP multicasting. |
| 63 | * Alan Cox : Cleaned up multicast handlers. |
| 64 | * Alan Cox : RAW sockets demultiplex in the BSD style. |
| 65 | * Gunther Mayer : Fix the SNMP reporting typo |
| 66 | * Alan Cox : Always in group 224.0.0.1 |
| 67 | * Pauline Middelink : Fast ip_checksum update when forwarding |
| 68 | * Masquerading support. |
| 69 | * Alan Cox : Multicast loopback error for 224.0.0.1 |
| 70 | * Alan Cox : IP_MULTICAST_LOOP option. |
| 71 | * Alan Cox : Use notifiers. |
| 72 | * Bjorn Ekwall : Removed ip_csum (from slhc.c too) |
| 73 | * Bjorn Ekwall : Moved ip_fast_csum to ip.h (inline!) |
| 74 | * Stefan Becker : Send out ICMP HOST REDIRECT |
| 75 | * Arnt Gulbrandsen : ip_build_xmit |
| 76 | * Alan Cox : Per socket routing cache |
| 77 | * Alan Cox : Fixed routing cache, added header cache. |
| 78 | * Alan Cox : Loopback didn't work right in original ip_build_xmit - fixed it. |
| 79 | * Alan Cox : Only send ICMP_REDIRECT if src/dest are the same net. |
| 80 | * Alan Cox : Incoming IP option handling. |
| 81 | * Alan Cox : Set saddr on raw output frames as per BSD. |
| 82 | * Alan Cox : Stopped broadcast source route explosions. |
| 83 | * Alan Cox : Can disable source routing |
| 84 | * Takeshi Sone : Masquerading didn't work. |
| 85 | * Dave Bonn,Alan Cox : Faster IP forwarding whenever possible. |
| 86 | * Alan Cox : Memory leaks, tramples, misc debugging. |
| 87 | * Alan Cox : Fixed multicast (by popular demand 8)) |
| 88 | * Alan Cox : Fixed forwarding (by even more popular demand 8)) |
| 89 | * Alan Cox : Fixed SNMP statistics [I think] |
| 90 | * Gerhard Koerting : IP fragmentation forwarding fix |
| 91 | * Alan Cox : Device lock against page fault. |
| 92 | * Alan Cox : IP_HDRINCL facility. |
| 93 | * Werner Almesberger : Zero fragment bug |
| 94 | * Alan Cox : RAW IP frame length bug |
| 95 | * Alan Cox : Outgoing firewall on build_xmit |
| 96 | * A.N.Kuznetsov : IP_OPTIONS support throughout the kernel |
| 97 | * Alan Cox : Multicast routing hooks |
| 98 | * Jos Vos : Do accounting *before* call_in_firewall |
| 99 | * Willy Konynenberg : Transparent proxying support |
| 100 | * |
| 101 | * |
| 102 | * |
| 103 | * To Fix: |
| 104 | * IP fragmentation wants rewriting cleanly. The RFC815 algorithm is much more efficient |
| 105 | * and could be made very efficient with the addition of some virtual memory hacks to permit |
| 106 | * the allocation of a buffer that can then be 'grown' by twiddling page tables. |
| 107 | * Output fragmentation wants updating along with the buffer management to use a single |
| 108 | * interleaved copy algorithm so that fragmenting has a one copy overhead. Actual packet |
| 109 | * output should probably do its own fragmentation at the UDP/RAW layer. TCP shouldn't cause |
| 110 | * fragmentation anyway. |
| 111 | * |
| 112 | * This program is free software; you can redistribute it and/or |
| 113 | * modify it under the terms of the GNU General Public License |
| 114 | * as published by the Free Software Foundation; either version |
| 115 | * 2 of the License, or (at your option) any later version. |
| 116 | */ |
| 117 | |
| 118 | #include <asm/system.h> |
| 119 | #include <linux/module.h> |
| 120 | #include <linux/types.h> |
| 121 | #include <linux/kernel.h> |
| 122 | #include <linux/string.h> |
| 123 | #include <linux/errno.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 124 | |
| 125 | #include <linux/net.h> |
| 126 | #include <linux/socket.h> |
| 127 | #include <linux/sockios.h> |
| 128 | #include <linux/in.h> |
| 129 | #include <linux/inet.h> |
Arnaldo Carvalho de Melo | 14c8502 | 2005-12-27 02:43:12 -0200 | [diff] [blame] | 130 | #include <linux/inetdevice.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 131 | #include <linux/netdevice.h> |
| 132 | #include <linux/etherdevice.h> |
| 133 | |
| 134 | #include <net/snmp.h> |
| 135 | #include <net/ip.h> |
| 136 | #include <net/protocol.h> |
| 137 | #include <net/route.h> |
| 138 | #include <linux/skbuff.h> |
| 139 | #include <net/sock.h> |
| 140 | #include <net/arp.h> |
| 141 | #include <net/icmp.h> |
| 142 | #include <net/raw.h> |
| 143 | #include <net/checksum.h> |
| 144 | #include <linux/netfilter_ipv4.h> |
| 145 | #include <net/xfrm.h> |
| 146 | #include <linux/mroute.h> |
| 147 | #include <linux/netlink.h> |
| 148 | |
| 149 | /* |
| 150 | * SNMP management statistics |
| 151 | */ |
| 152 | |
Eric Dumazet | ba89966 | 2005-08-26 12:05:31 -0700 | [diff] [blame] | 153 | DEFINE_SNMP_STAT(struct ipstats_mib, ip_statistics) __read_mostly; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 154 | |
| 155 | /* |
| 156 | * Process Router Attention IP option |
| 157 | */ |
| 158 | int ip_call_ra_chain(struct sk_buff *skb) |
| 159 | { |
| 160 | struct ip_ra_chain *ra; |
| 161 | u8 protocol = skb->nh.iph->protocol; |
| 162 | struct sock *last = NULL; |
| 163 | |
| 164 | read_lock(&ip_ra_lock); |
| 165 | for (ra = ip_ra_chain; ra; ra = ra->next) { |
| 166 | struct sock *sk = ra->sk; |
| 167 | |
| 168 | /* If socket is bound to an interface, only report |
| 169 | * the packet if it came from that interface. |
| 170 | */ |
| 171 | if (sk && inet_sk(sk)->num == protocol && |
| 172 | (!sk->sk_bound_dev_if || |
| 173 | sk->sk_bound_dev_if == skb->dev->ifindex)) { |
| 174 | if (skb->nh.iph->frag_off & htons(IP_MF|IP_OFFSET)) { |
| 175 | skb = ip_defrag(skb, IP_DEFRAG_CALL_RA_CHAIN); |
| 176 | if (skb == NULL) { |
| 177 | read_unlock(&ip_ra_lock); |
| 178 | return 1; |
| 179 | } |
| 180 | } |
| 181 | if (last) { |
| 182 | struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC); |
| 183 | if (skb2) |
| 184 | raw_rcv(last, skb2); |
| 185 | } |
| 186 | last = sk; |
| 187 | } |
| 188 | } |
| 189 | |
| 190 | if (last) { |
| 191 | raw_rcv(last, skb); |
| 192 | read_unlock(&ip_ra_lock); |
| 193 | return 1; |
| 194 | } |
| 195 | read_unlock(&ip_ra_lock); |
| 196 | return 0; |
| 197 | } |
| 198 | |
| 199 | static inline int ip_local_deliver_finish(struct sk_buff *skb) |
| 200 | { |
| 201 | int ihl = skb->nh.iph->ihl*4; |
| 202 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 203 | __skb_pull(skb, ihl); |
| 204 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 205 | /* Point into the IP datagram, just past the header. */ |
| 206 | skb->h.raw = skb->data; |
| 207 | |
| 208 | rcu_read_lock(); |
| 209 | { |
| 210 | /* Note: See raw.c and net/raw.h, RAWV4_HTABLE_SIZE==MAX_INET_PROTOS */ |
| 211 | int protocol = skb->nh.iph->protocol; |
| 212 | int hash; |
| 213 | struct sock *raw_sk; |
| 214 | struct net_protocol *ipprot; |
| 215 | |
| 216 | resubmit: |
| 217 | hash = protocol & (MAX_INET_PROTOS - 1); |
| 218 | raw_sk = sk_head(&raw_v4_htable[hash]); |
| 219 | |
| 220 | /* If there maybe a raw socket we must check - if not we |
| 221 | * don't care less |
| 222 | */ |
Patrick McHardy | d13964f | 2005-08-09 19:45:02 -0700 | [diff] [blame] | 223 | if (raw_sk && !raw_v4_input(skb, skb->nh.iph, hash)) |
| 224 | raw_sk = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 225 | |
| 226 | if ((ipprot = rcu_dereference(inet_protos[hash])) != NULL) { |
| 227 | int ret; |
| 228 | |
Patrick McHardy | b59c270 | 2006-01-06 23:06:10 -0800 | [diff] [blame] | 229 | if (!ipprot->no_policy) { |
| 230 | if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) { |
| 231 | kfree_skb(skb); |
| 232 | goto out; |
| 233 | } |
| 234 | nf_reset(skb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 235 | } |
| 236 | ret = ipprot->handler(skb); |
| 237 | if (ret < 0) { |
| 238 | protocol = -ret; |
| 239 | goto resubmit; |
| 240 | } |
| 241 | IP_INC_STATS_BH(IPSTATS_MIB_INDELIVERS); |
| 242 | } else { |
| 243 | if (!raw_sk) { |
| 244 | if (xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) { |
| 245 | IP_INC_STATS_BH(IPSTATS_MIB_INUNKNOWNPROTOS); |
| 246 | icmp_send(skb, ICMP_DEST_UNREACH, |
| 247 | ICMP_PROT_UNREACH, 0); |
| 248 | } |
| 249 | } else |
| 250 | IP_INC_STATS_BH(IPSTATS_MIB_INDELIVERS); |
| 251 | kfree_skb(skb); |
| 252 | } |
| 253 | } |
| 254 | out: |
| 255 | rcu_read_unlock(); |
| 256 | |
| 257 | return 0; |
| 258 | } |
| 259 | |
| 260 | /* |
| 261 | * Deliver IP Packets to the higher protocol layers. |
| 262 | */ |
| 263 | int ip_local_deliver(struct sk_buff *skb) |
| 264 | { |
| 265 | /* |
| 266 | * Reassemble IP fragments. |
| 267 | */ |
| 268 | |
| 269 | if (skb->nh.iph->frag_off & htons(IP_MF|IP_OFFSET)) { |
| 270 | skb = ip_defrag(skb, IP_DEFRAG_LOCAL_DELIVER); |
| 271 | if (!skb) |
| 272 | return 0; |
| 273 | } |
| 274 | |
| 275 | return NF_HOOK(PF_INET, NF_IP_LOCAL_IN, skb, skb->dev, NULL, |
| 276 | ip_local_deliver_finish); |
| 277 | } |
| 278 | |
Thomas Graf | d245407 | 2005-08-20 17:26:12 -0700 | [diff] [blame] | 279 | static inline int ip_rcv_options(struct sk_buff *skb) |
| 280 | { |
| 281 | struct ip_options *opt; |
| 282 | struct iphdr *iph; |
| 283 | struct net_device *dev = skb->dev; |
| 284 | |
| 285 | /* It looks as overkill, because not all |
| 286 | IP options require packet mangling. |
| 287 | But it is the easiest for now, especially taking |
| 288 | into account that combination of IP options |
| 289 | and running sniffer is extremely rare condition. |
| 290 | --ANK (980813) |
| 291 | */ |
| 292 | if (skb_cow(skb, skb_headroom(skb))) { |
| 293 | IP_INC_STATS_BH(IPSTATS_MIB_INDISCARDS); |
| 294 | goto drop; |
| 295 | } |
| 296 | |
| 297 | iph = skb->nh.iph; |
| 298 | |
| 299 | if (ip_options_compile(NULL, skb)) { |
| 300 | IP_INC_STATS_BH(IPSTATS_MIB_INHDRERRORS); |
| 301 | goto drop; |
| 302 | } |
| 303 | |
| 304 | opt = &(IPCB(skb)->opt); |
| 305 | if (unlikely(opt->srr)) { |
| 306 | struct in_device *in_dev = in_dev_get(dev); |
| 307 | if (in_dev) { |
| 308 | if (!IN_DEV_SOURCE_ROUTE(in_dev)) { |
| 309 | if (IN_DEV_LOG_MARTIANS(in_dev) && |
| 310 | net_ratelimit()) |
| 311 | printk(KERN_INFO "source route option " |
| 312 | "%u.%u.%u.%u -> %u.%u.%u.%u\n", |
| 313 | NIPQUAD(iph->saddr), |
| 314 | NIPQUAD(iph->daddr)); |
| 315 | in_dev_put(in_dev); |
| 316 | goto drop; |
| 317 | } |
| 318 | |
| 319 | in_dev_put(in_dev); |
| 320 | } |
| 321 | |
| 322 | if (ip_options_rcv_srr(skb)) |
| 323 | goto drop; |
| 324 | } |
| 325 | |
| 326 | return 0; |
| 327 | drop: |
| 328 | return -1; |
| 329 | } |
| 330 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 331 | static inline int ip_rcv_finish(struct sk_buff *skb) |
| 332 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 333 | struct iphdr *iph = skb->nh.iph; |
| 334 | |
| 335 | /* |
| 336 | * Initialise the virtual path cache for the packet. It describes |
| 337 | * how the packet travels inside Linux networking. |
| 338 | */ |
Hua Zhong | 0182bd2 | 2006-05-06 18:11:39 -0700 | [diff] [blame] | 339 | if (skb->dst == NULL) { |
Thomas Graf | 3e192be | 2005-08-20 17:26:30 -0700 | [diff] [blame] | 340 | int err = ip_route_input(skb, iph->daddr, iph->saddr, iph->tos, |
| 341 | skb->dev); |
| 342 | if (unlikely(err)) { |
Dietmar Eggemann | 2c2910a | 2005-06-28 13:06:23 -0700 | [diff] [blame] | 343 | if (err == -EHOSTUNREACH) |
| 344 | IP_INC_STATS_BH(IPSTATS_MIB_INADDRERRORS); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 345 | goto drop; |
Dietmar Eggemann | 2c2910a | 2005-06-28 13:06:23 -0700 | [diff] [blame] | 346 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 347 | } |
| 348 | |
| 349 | #ifdef CONFIG_NET_CLS_ROUTE |
Thomas Graf | 3e192be | 2005-08-20 17:26:30 -0700 | [diff] [blame] | 350 | if (unlikely(skb->dst->tclassid)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 351 | struct ip_rt_acct *st = ip_rt_acct + 256*smp_processor_id(); |
| 352 | u32 idx = skb->dst->tclassid; |
| 353 | st[idx&0xFF].o_packets++; |
| 354 | st[idx&0xFF].o_bytes+=skb->len; |
| 355 | st[(idx>>16)&0xFF].i_packets++; |
| 356 | st[(idx>>16)&0xFF].i_bytes+=skb->len; |
| 357 | } |
| 358 | #endif |
| 359 | |
Thomas Graf | d245407 | 2005-08-20 17:26:12 -0700 | [diff] [blame] | 360 | if (iph->ihl > 5 && ip_rcv_options(skb)) |
| 361 | goto drop; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 362 | |
| 363 | return dst_input(skb); |
| 364 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 365 | drop: |
| 366 | kfree_skb(skb); |
| 367 | return NET_RX_DROP; |
| 368 | } |
| 369 | |
| 370 | /* |
| 371 | * Main IP Receive routine. |
| 372 | */ |
David S. Miller | f2ccd8f | 2005-08-09 19:34:12 -0700 | [diff] [blame] | 373 | int ip_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 374 | { |
| 375 | struct iphdr *iph; |
Thomas Graf | 5861524 | 2005-08-20 17:25:29 -0700 | [diff] [blame] | 376 | u32 len; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 377 | |
| 378 | /* When the interface is in promisc. mode, drop all the crap |
| 379 | * that it receives, do not try to analyse it. |
| 380 | */ |
| 381 | if (skb->pkt_type == PACKET_OTHERHOST) |
| 382 | goto drop; |
| 383 | |
| 384 | IP_INC_STATS_BH(IPSTATS_MIB_INRECEIVES); |
| 385 | |
| 386 | if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL) { |
| 387 | IP_INC_STATS_BH(IPSTATS_MIB_INDISCARDS); |
| 388 | goto out; |
| 389 | } |
| 390 | |
| 391 | if (!pskb_may_pull(skb, sizeof(struct iphdr))) |
| 392 | goto inhdr_error; |
| 393 | |
| 394 | iph = skb->nh.iph; |
| 395 | |
| 396 | /* |
| 397 | * RFC1122: 3.1.2.2 MUST silently discard any IP frame that fails the checksum. |
| 398 | * |
| 399 | * Is the datagram acceptable? |
| 400 | * |
| 401 | * 1. Length at least the size of an ip header |
| 402 | * 2. Version of 4 |
| 403 | * 3. Checksums correctly. [Speed optimisation for later, skip loopback checksums] |
| 404 | * 4. Doesn't have a bogus length |
| 405 | */ |
| 406 | |
| 407 | if (iph->ihl < 5 || iph->version != 4) |
Thomas Graf | 5861524 | 2005-08-20 17:25:29 -0700 | [diff] [blame] | 408 | goto inhdr_error; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 409 | |
| 410 | if (!pskb_may_pull(skb, iph->ihl*4)) |
| 411 | goto inhdr_error; |
| 412 | |
| 413 | iph = skb->nh.iph; |
| 414 | |
Thomas Graf | e9c6042 | 2005-08-20 17:25:52 -0700 | [diff] [blame] | 415 | if (unlikely(ip_fast_csum((u8 *)iph, iph->ihl))) |
Thomas Graf | 5861524 | 2005-08-20 17:25:29 -0700 | [diff] [blame] | 416 | goto inhdr_error; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 417 | |
Thomas Graf | 5861524 | 2005-08-20 17:25:29 -0700 | [diff] [blame] | 418 | len = ntohs(iph->tot_len); |
| 419 | if (skb->len < len || len < (iph->ihl*4)) |
| 420 | goto inhdr_error; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 421 | |
Thomas Graf | 5861524 | 2005-08-20 17:25:29 -0700 | [diff] [blame] | 422 | /* Our transport medium may have padded the buffer out. Now we know it |
| 423 | * is IP we can trim to the true length of the frame. |
| 424 | * Note this now means skb->len holds ntohs(iph->tot_len). |
| 425 | */ |
| 426 | if (pskb_trim_rcsum(skb, len)) { |
| 427 | IP_INC_STATS_BH(IPSTATS_MIB_INDISCARDS); |
| 428 | goto drop; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 429 | } |
| 430 | |
| 431 | return NF_HOOK(PF_INET, NF_IP_PRE_ROUTING, skb, dev, NULL, |
| 432 | ip_rcv_finish); |
| 433 | |
| 434 | inhdr_error: |
| 435 | IP_INC_STATS_BH(IPSTATS_MIB_INHDRERRORS); |
| 436 | drop: |
| 437 | kfree_skb(skb); |
| 438 | out: |
| 439 | return NET_RX_DROP; |
| 440 | } |
| 441 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 442 | EXPORT_SYMBOL(ip_statistics); |