1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * INET An implementation of the TCP/IP protocol suite for the LINUX 4 * operating system. INET is implemented using the BSD Socket 5 * interface as the means of communication with the user level. 6 * 7 * The Internet Protocol (IP) module. 8 * 9 * Authors: Ross Biro 10 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> 11 * Donald Becker, <becker@super.org> 12 * Alan Cox, <alan@lxorguk.ukuu.org.uk> 13 * Richard Underwood 14 * Stefan Becker, <stefanb@yello.ping.de> 15 * Jorge Cwik, <jorge@laser.satlink.net> 16 * Arnt Gulbrandsen, <agulbra@nvg.unit.no> 17 * 18 * Fixes: 19 * Alan Cox : Commented a couple of minor bits of surplus code 20 * Alan Cox : Undefining IP_FORWARD doesn't include the code 21 * (just stops a compiler warning). 22 * Alan Cox : Frames with >=MAX_ROUTE record routes, strict routes or loose routes 23 * are junked rather than corrupting things. 24 * Alan Cox : Frames to bad broadcast subnets are dumped 25 * We used to process them non broadcast and 26 * boy could that cause havoc. 27 * Alan Cox : ip_forward sets the free flag on the 28 * new frame it queues. Still crap because 29 * it copies the frame but at least it 30 * doesn't eat memory too. 31 * Alan Cox : Generic queue code and memory fixes. 32 * Fred Van Kempen : IP fragment support (borrowed from NET2E) 33 * Gerhard Koerting: Forward fragmented frames correctly. 34 * Gerhard Koerting: Fixes to my fix of the above 8-). 35 * Gerhard Koerting: IP interface addressing fix. 36 * Linus Torvalds : More robustness checks 37 * Alan Cox : Even more checks: Still not as robust as it ought to be 38 * Alan Cox : Save IP header pointer for later 39 * Alan Cox : ip option setting 40 * Alan Cox : Use ip_tos/ip_ttl settings 41 * Alan Cox : Fragmentation bogosity removed 42 * (Thanks to Mark.Bush@prg.ox.ac.uk) 43 * Dmitry Gorodchanin : Send of a raw packet crash fix. 44 * Alan Cox : Silly ip bug when an overlength 45 * fragment turns up. Now frees the 46 * queue. 47 * Linus Torvalds/ : Memory leakage on fragmentation 48 * Alan Cox : handling. 49 * Gerhard Koerting: Forwarding uses IP priority hints 50 * Teemu Rantanen : Fragment problems. 51 * Alan Cox : General cleanup, comments and reformat 52 * Alan Cox : SNMP statistics 53 * Alan Cox : BSD address rule semantics. Also see 54 * UDP as there is a nasty checksum issue 55 * if you do things the wrong way. 56 * Alan Cox : Always defrag, moved IP_FORWARD to the config.in file 57 * Alan Cox : IP options adjust sk->priority. 58 * Pedro Roque : Fix mtu/length error in ip_forward. 59 * Alan Cox : Avoid ip_chk_addr when possible. 60 * Richard Underwood : IP multicasting. 61 * Alan Cox : Cleaned up multicast handlers. 62 * Alan Cox : RAW sockets demultiplex in the BSD style. 63 * Gunther Mayer : Fix the SNMP reporting typo 64 * Alan Cox : Always in group 224.0.0.1 65 * Pauline Middelink : Fast ip_checksum update when forwarding 66 * Masquerading support. 67 * Alan Cox : Multicast loopback error for 224.0.0.1 68 * Alan Cox : IP_MULTICAST_LOOP option. 69 * Alan Cox : Use notifiers. 70 * Bjorn Ekwall : Removed ip_csum (from slhc.c too) 71 * Bjorn Ekwall : Moved ip_fast_csum to ip.h (inline!) 72 * Stefan Becker : Send out ICMP HOST REDIRECT 73 * Arnt Gulbrandsen : ip_build_xmit 74 * Alan Cox : Per socket routing cache 75 * Alan Cox : Fixed routing cache, added header cache. 76 * Alan Cox : Loopback didn't work right in original ip_build_xmit - fixed it. 77 * Alan Cox : Only send ICMP_REDIRECT if src/dest are the same net. 78 * Alan Cox : Incoming IP option handling. 79 * Alan Cox : Set saddr on raw output frames as per BSD. 80 * Alan Cox : Stopped broadcast source route explosions. 81 * Alan Cox : Can disable source routing 82 * Takeshi Sone : Masquerading didn't work. 83 * Dave Bonn,Alan Cox : Faster IP forwarding whenever possible. 84 * Alan Cox : Memory leaks, tramples, misc debugging. 85 * Alan Cox : Fixed multicast (by popular demand 8)) 86 * Alan Cox : Fixed forwarding (by even more popular demand 8)) 87 * Alan Cox : Fixed SNMP statistics [I think] 88 * Gerhard Koerting : IP fragmentation forwarding fix 89 * Alan Cox : Device lock against page fault. 90 * Alan Cox : IP_HDRINCL facility. 91 * Werner Almesberger : Zero fragment bug 92 * Alan Cox : RAW IP frame length bug 93 * Alan Cox : Outgoing firewall on build_xmit 94 * A.N.Kuznetsov : IP_OPTIONS support throughout the kernel 95 * Alan Cox : Multicast routing hooks 96 * Jos Vos : Do accounting *before* call_in_firewall 97 * Willy Konynenberg : Transparent proxying support 98 * 99 * To Fix: 100 * IP fragmentation wants rewriting cleanly. The RFC815 algorithm is much more efficient 101 * and could be made very efficient with the addition of some virtual memory hacks to permit 102 * the allocation of a buffer that can then be 'grown' by twiddling page tables. 103 * Output fragmentation wants updating along with the buffer management to use a single 104 * interleaved copy algorithm so that fragmenting has a one copy overhead. Actual packet 105 * output should probably do its own fragmentation at the UDP/RAW layer. TCP shouldn't cause 106 * fragmentation anyway. 107 */ 108 109 #define pr_fmt(fmt) "IPv4: " fmt 110 111 #include <linux/module.h> 112 #include <linux/types.h> 113 #include <linux/kernel.h> 114 #include <linux/string.h> 115 #include <linux/errno.h> 116 #include <linux/slab.h> 117 118 #include <linux/net.h> 119 #include <linux/socket.h> 120 #include <linux/sockios.h> 121 #include <linux/in.h> 122 #include <linux/inet.h> 123 #include <linux/inetdevice.h> 124 #include <linux/netdevice.h> 125 #include <linux/etherdevice.h> 126 #include <linux/indirect_call_wrapper.h> 127 128 #include <net/snmp.h> 129 #include <net/ip.h> 130 #include <net/protocol.h> 131 #include <net/route.h> 132 #include <linux/skbuff.h> 133 #include <net/sock.h> 134 #include <net/arp.h> 135 #include <net/icmp.h> 136 #include <net/raw.h> 137 #include <net/checksum.h> 138 #include <net/inet_ecn.h> 139 #include <linux/netfilter_ipv4.h> 140 #include <net/xfrm.h> 141 #include <linux/mroute.h> 142 #include <linux/netlink.h> 143 #include <net/dst_metadata.h> 144 145 /* 146 * Process Router Attention IP option (RFC 2113) 147 */ 148 bool ip_call_ra_chain(struct sk_buff *skb) 149 { 150 struct ip_ra_chain *ra; 151 u8 protocol = ip_hdr(skb)->protocol; 152 struct sock *last = NULL; 153 struct net_device *dev = skb->dev; 154 struct net *net = dev_net(dev); 155 156 for (ra = rcu_dereference(net->ipv4.ra_chain); ra; ra = rcu_dereference(ra->next)) { 157 struct sock *sk = ra->sk; 158 159 /* If socket is bound to an interface, only report 160 * the packet if it came from that interface. 161 */ 162 if (sk && inet_sk(sk)->inet_num == protocol && 163 (!sk->sk_bound_dev_if || 164 sk->sk_bound_dev_if == dev->ifindex)) { 165 if (ip_is_fragment(ip_hdr(skb))) { 166 if (ip_defrag(net, skb, IP_DEFRAG_CALL_RA_CHAIN)) 167 return true; 168 } 169 if (last) { 170 struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC); 171 if (skb2) 172 raw_rcv(last, skb2); 173 } 174 last = sk; 175 } 176 } 177 178 if (last) { 179 raw_rcv(last, skb); 180 return true; 181 } 182 return false; 183 } 184 185 INDIRECT_CALLABLE_DECLARE(int udp_rcv(struct sk_buff *)); 186 INDIRECT_CALLABLE_DECLARE(int tcp_v4_rcv(struct sk_buff *)); 187 void ip_protocol_deliver_rcu(struct net *net, struct sk_buff *skb, int protocol) 188 { 189 const struct net_protocol *ipprot; 190 int raw, ret; 191 192 resubmit: 193 raw = raw_local_deliver(skb, protocol); 194 195 ipprot = rcu_dereference(inet_protos[protocol]); 196 if (ipprot) { 197 if (!ipprot->no_policy) { 198 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) { 199 kfree_skb(skb); 200 return; 201 } 202 nf_reset_ct(skb); 203 } 204 ret = INDIRECT_CALL_2(ipprot->handler, tcp_v4_rcv, udp_rcv, 205 skb); 206 if (ret < 0) { 207 protocol = -ret; 208 goto resubmit; 209 } 210 __IP_INC_STATS(net, IPSTATS_MIB_INDELIVERS); 211 } else { 212 if (!raw) { 213 if (xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) { 214 __IP_INC_STATS(net, IPSTATS_MIB_INUNKNOWNPROTOS); 215 icmp_send(skb, ICMP_DEST_UNREACH, 216 ICMP_PROT_UNREACH, 0); 217 } 218 kfree_skb(skb); 219 } else { 220 __IP_INC_STATS(net, IPSTATS_MIB_INDELIVERS); 221 consume_skb(skb); 222 } 223 } 224 } 225 226 static int ip_local_deliver_finish(struct net *net, struct sock *sk, struct sk_buff *skb) 227 { 228 __skb_pull(skb, skb_network_header_len(skb)); 229 230 rcu_read_lock(); 231 ip_protocol_deliver_rcu(net, skb, ip_hdr(skb)->protocol); 232 rcu_read_unlock(); 233 234 return 0; 235 } 236 237 /* 238 * Deliver IP Packets to the higher protocol layers. 239 */ 240 int ip_local_deliver(struct sk_buff *skb) 241 { 242 /* 243 * Reassemble IP fragments. 244 */ 245 struct net *net = dev_net(skb->dev); 246 247 if (ip_is_fragment(ip_hdr(skb))) { 248 if (ip_defrag(net, skb, IP_DEFRAG_LOCAL_DELIVER)) 249 return 0; 250 } 251 252 return NF_HOOK(NFPROTO_IPV4, NF_INET_LOCAL_IN, 253 net, NULL, skb, skb->dev, NULL, 254 ip_local_deliver_finish); 255 } 256 257 static inline bool ip_rcv_options(struct sk_buff *skb, struct net_device *dev) 258 { 259 struct ip_options *opt; 260 const struct iphdr *iph; 261 262 /* It looks as overkill, because not all 263 IP options require packet mangling. 264 But it is the easiest for now, especially taking 265 into account that combination of IP options 266 and running sniffer is extremely rare condition. 267 --ANK (980813) 268 */ 269 if (skb_cow(skb, skb_headroom(skb))) { 270 __IP_INC_STATS(dev_net(dev), IPSTATS_MIB_INDISCARDS); 271 goto drop; 272 } 273 274 iph = ip_hdr(skb); 275 opt = &(IPCB(skb)->opt); 276 opt->optlen = iph->ihl*4 - sizeof(struct iphdr); 277 278 if (ip_options_compile(dev_net(dev), opt, skb)) { 279 __IP_INC_STATS(dev_net(dev), IPSTATS_MIB_INHDRERRORS); 280 goto drop; 281 } 282 283 if (unlikely(opt->srr)) { 284 struct in_device *in_dev = __in_dev_get_rcu(dev); 285 286 if (in_dev) { 287 if (!IN_DEV_SOURCE_ROUTE(in_dev)) { 288 if (IN_DEV_LOG_MARTIANS(in_dev)) 289 net_info_ratelimited("source route option %pI4 -> %pI4\n", 290 &iph->saddr, 291 &iph->daddr); 292 goto drop; 293 } 294 } 295 296 if (ip_options_rcv_srr(skb, dev)) 297 goto drop; 298 } 299 300 return false; 301 drop: 302 return true; 303 } 304 305 static bool ip_can_use_hint(const struct sk_buff *skb, const struct iphdr *iph, 306 const struct sk_buff *hint) 307 { 308 return hint && !skb_dst(skb) && ip_hdr(hint)->daddr == iph->daddr && 309 ip_hdr(hint)->tos == iph->tos; 310 } 311 312 INDIRECT_CALLABLE_DECLARE(int udp_v4_early_demux(struct sk_buff *)); 313 INDIRECT_CALLABLE_DECLARE(int tcp_v4_early_demux(struct sk_buff *)); 314 static int ip_rcv_finish_core(struct net *net, struct sock *sk, 315 struct sk_buff *skb, struct net_device *dev, 316 const struct sk_buff *hint) 317 { 318 const struct iphdr *iph = ip_hdr(skb); 319 int (*edemux)(struct sk_buff *skb); 320 struct rtable *rt; 321 int err; 322 323 if (ip_can_use_hint(skb, iph, hint)) { 324 err = ip_route_use_hint(skb, iph->daddr, iph->saddr, iph->tos, 325 dev, hint); 326 if (unlikely(err)) 327 goto drop_error; 328 } 329 330 if (net->ipv4.sysctl_ip_early_demux && 331 !skb_dst(skb) && 332 !skb->sk && 333 !ip_is_fragment(iph)) { 334 const struct net_protocol *ipprot; 335 int protocol = iph->protocol; 336 337 ipprot = rcu_dereference(inet_protos[protocol]); 338 if (ipprot && (edemux = READ_ONCE(ipprot->early_demux))) { 339 err = INDIRECT_CALL_2(edemux, tcp_v4_early_demux, 340 udp_v4_early_demux, skb); 341 if (unlikely(err)) 342 goto drop_error; 343 /* must reload iph, skb->head might have changed */ 344 iph = ip_hdr(skb); 345 } 346 } 347 348 /* 349 * Initialise the virtual path cache for the packet. It describes 350 * how the packet travels inside Linux networking. 351 */ 352 if (!skb_valid_dst(skb)) { 353 err = ip_route_input_noref(skb, iph->daddr, iph->saddr, 354 iph->tos, dev); 355 if (unlikely(err)) 356 goto drop_error; 357 } 358 359 #ifdef CONFIG_IP_ROUTE_CLASSID 360 if (unlikely(skb_dst(skb)->tclassid)) { 361 struct ip_rt_acct *st = this_cpu_ptr(ip_rt_acct); 362 u32 idx = skb_dst(skb)->tclassid; 363 st[idx&0xFF].o_packets++; 364 st[idx&0xFF].o_bytes += skb->len; 365 st[(idx>>16)&0xFF].i_packets++; 366 st[(idx>>16)&0xFF].i_bytes += skb->len; 367 } 368 #endif 369 370 if (iph->ihl > 5 && ip_rcv_options(skb, dev)) 371 goto drop; 372 373 rt = skb_rtable(skb); 374 if (rt->rt_type == RTN_MULTICAST) { 375 __IP_UPD_PO_STATS(net, IPSTATS_MIB_INMCAST, skb->len); 376 } else if (rt->rt_type == RTN_BROADCAST) { 377 __IP_UPD_PO_STATS(net, IPSTATS_MIB_INBCAST, skb->len); 378 } else if (skb->pkt_type == PACKET_BROADCAST || 379 skb->pkt_type == PACKET_MULTICAST) { 380 struct in_device *in_dev = __in_dev_get_rcu(dev); 381 382 /* RFC 1122 3.3.6: 383 * 384 * When a host sends a datagram to a link-layer broadcast 385 * address, the IP destination address MUST be a legal IP 386 * broadcast or IP multicast address. 387 * 388 * A host SHOULD silently discard a datagram that is received 389 * via a link-layer broadcast (see Section 2.4) but does not 390 * specify an IP multicast or broadcast destination address. 391 * 392 * This doesn't explicitly say L2 *broadcast*, but broadcast is 393 * in a way a form of multicast and the most common use case for 394 * this is 802.11 protecting against cross-station spoofing (the 395 * so-called "hole-196" attack) so do it for both. 396 */ 397 if (in_dev && 398 IN_DEV_ORCONF(in_dev, DROP_UNICAST_IN_L2_MULTICAST)) 399 goto drop; 400 } 401 402 return NET_RX_SUCCESS; 403 404 drop: 405 kfree_skb(skb); 406 return NET_RX_DROP; 407 408 drop_error: 409 if (err == -EXDEV) 410 __NET_INC_STATS(net, LINUX_MIB_IPRPFILTER); 411 goto drop; 412 } 413 414 static int ip_rcv_finish(struct net *net, struct sock *sk, struct sk_buff *skb) 415 { 416 struct net_device *dev = skb->dev; 417 int ret; 418 419 /* if ingress device is enslaved to an L3 master device pass the 420 * skb to its handler for processing 421 */ 422 skb = l3mdev_ip_rcv(skb); 423 if (!skb) 424 return NET_RX_SUCCESS; 425 426 ret = ip_rcv_finish_core(net, sk, skb, dev, NULL); 427 if (ret != NET_RX_DROP) 428 ret = dst_input(skb); 429 return ret; 430 } 431 432 /* 433 * Main IP Receive routine. 434 */ 435 static struct sk_buff *ip_rcv_core(struct sk_buff *skb, struct net *net) 436 { 437 const struct iphdr *iph; 438 u32 len; 439 440 /* When the interface is in promisc. mode, drop all the crap 441 * that it receives, do not try to analyse it. 442 */ 443 if (skb->pkt_type == PACKET_OTHERHOST) 444 goto drop; 445 446 __IP_UPD_PO_STATS(net, IPSTATS_MIB_IN, skb->len); 447 448 skb = skb_share_check(skb, GFP_ATOMIC); 449 if (!skb) { 450 __IP_INC_STATS(net, IPSTATS_MIB_INDISCARDS); 451 goto out; 452 } 453 454 if (!pskb_may_pull(skb, sizeof(struct iphdr))) 455 goto inhdr_error; 456 457 iph = ip_hdr(skb); 458 459 /* 460 * RFC1122: 3.2.1.2 MUST silently discard any IP frame that fails the checksum. 461 * 462 * Is the datagram acceptable? 463 * 464 * 1. Length at least the size of an ip header 465 * 2. Version of 4 466 * 3. Checksums correctly. [Speed optimisation for later, skip loopback checksums] 467 * 4. Doesn't have a bogus length 468 */ 469 470 if (iph->ihl < 5 || iph->version != 4) 471 goto inhdr_error; 472 473 BUILD_BUG_ON(IPSTATS_MIB_ECT1PKTS != IPSTATS_MIB_NOECTPKTS + INET_ECN_ECT_1); 474 BUILD_BUG_ON(IPSTATS_MIB_ECT0PKTS != IPSTATS_MIB_NOECTPKTS + INET_ECN_ECT_0); 475 BUILD_BUG_ON(IPSTATS_MIB_CEPKTS != IPSTATS_MIB_NOECTPKTS + INET_ECN_CE); 476 __IP_ADD_STATS(net, 477 IPSTATS_MIB_NOECTPKTS + (iph->tos & INET_ECN_MASK), 478 max_t(unsigned short, 1, skb_shinfo(skb)->gso_segs)); 479 480 if (!pskb_may_pull(skb, iph->ihl*4)) 481 goto inhdr_error; 482 483 iph = ip_hdr(skb); 484 485 if (unlikely(ip_fast_csum((u8 *)iph, iph->ihl))) 486 goto csum_error; 487 488 len = ntohs(iph->tot_len); 489 if (skb->len < len) { 490 __IP_INC_STATS(net, IPSTATS_MIB_INTRUNCATEDPKTS); 491 goto drop; 492 } else if (len < (iph->ihl*4)) 493 goto inhdr_error; 494 495 /* Our transport medium may have padded the buffer out. Now we know it 496 * is IP we can trim to the true length of the frame. 497 * Note this now means skb->len holds ntohs(iph->tot_len). 498 */ 499 if (pskb_trim_rcsum(skb, len)) { 500 __IP_INC_STATS(net, IPSTATS_MIB_INDISCARDS); 501 goto drop; 502 } 503 504 iph = ip_hdr(skb); 505 skb->transport_header = skb->network_header + iph->ihl*4; 506 507 /* Remove any debris in the socket control block */ 508 memset(IPCB(skb), 0, sizeof(struct inet_skb_parm)); 509 IPCB(skb)->iif = skb->skb_iif; 510 511 /* Must drop socket now because of tproxy. */ 512 skb_orphan(skb); 513 514 return skb; 515 516 csum_error: 517 __IP_INC_STATS(net, IPSTATS_MIB_CSUMERRORS); 518 inhdr_error: 519 __IP_INC_STATS(net, IPSTATS_MIB_INHDRERRORS); 520 drop: 521 kfree_skb(skb); 522 out: 523 return NULL; 524 } 525 526 /* 527 * IP receive entry point 528 */ 529 int ip_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, 530 struct net_device *orig_dev) 531 { 532 struct net *net = dev_net(dev); 533 534 skb = ip_rcv_core(skb, net); 535 if (skb == NULL) 536 return NET_RX_DROP; 537 538 return NF_HOOK(NFPROTO_IPV4, NF_INET_PRE_ROUTING, 539 net, NULL, skb, dev, NULL, 540 ip_rcv_finish); 541 } 542 543 static void ip_sublist_rcv_finish(struct list_head *head) 544 { 545 struct sk_buff *skb, *next; 546 547 list_for_each_entry_safe(skb, next, head, list) { 548 skb_list_del_init(skb); 549 dst_input(skb); 550 } 551 } 552 553 static struct sk_buff *ip_extract_route_hint(const struct net *net, 554 struct sk_buff *skb, int rt_type) 555 { 556 if (fib4_has_custom_rules(net) || rt_type == RTN_BROADCAST) 557 return NULL; 558 559 return skb; 560 } 561 562 static void ip_list_rcv_finish(struct net *net, struct sock *sk, 563 struct list_head *head) 564 { 565 struct sk_buff *skb, *next, *hint = NULL; 566 struct dst_entry *curr_dst = NULL; 567 struct list_head sublist; 568 569 INIT_LIST_HEAD(&sublist); 570 list_for_each_entry_safe(skb, next, head, list) { 571 struct net_device *dev = skb->dev; 572 struct dst_entry *dst; 573 574 skb_list_del_init(skb); 575 /* if ingress device is enslaved to an L3 master device pass the 576 * skb to its handler for processing 577 */ 578 skb = l3mdev_ip_rcv(skb); 579 if (!skb) 580 continue; 581 if (ip_rcv_finish_core(net, sk, skb, dev, hint) == NET_RX_DROP) 582 continue; 583 584 dst = skb_dst(skb); 585 if (curr_dst != dst) { 586 hint = ip_extract_route_hint(net, skb, 587 ((struct rtable *)dst)->rt_type); 588 589 /* dispatch old sublist */ 590 if (!list_empty(&sublist)) 591 ip_sublist_rcv_finish(&sublist); 592 /* start new sublist */ 593 INIT_LIST_HEAD(&sublist); 594 curr_dst = dst; 595 } 596 list_add_tail(&skb->list, &sublist); 597 } 598 /* dispatch final sublist */ 599 ip_sublist_rcv_finish(&sublist); 600 } 601 602 static void ip_sublist_rcv(struct list_head *head, struct net_device *dev, 603 struct net *net) 604 { 605 NF_HOOK_LIST(NFPROTO_IPV4, NF_INET_PRE_ROUTING, net, NULL, 606 head, dev, NULL, ip_rcv_finish); 607 ip_list_rcv_finish(net, NULL, head); 608 } 609 610 /* Receive a list of IP packets */ 611 void ip_list_rcv(struct list_head *head, struct packet_type *pt, 612 struct net_device *orig_dev) 613 { 614 struct net_device *curr_dev = NULL; 615 struct net *curr_net = NULL; 616 struct sk_buff *skb, *next; 617 struct list_head sublist; 618 619 INIT_LIST_HEAD(&sublist); 620 list_for_each_entry_safe(skb, next, head, list) { 621 struct net_device *dev = skb->dev; 622 struct net *net = dev_net(dev); 623 624 skb_list_del_init(skb); 625 skb = ip_rcv_core(skb, net); 626 if (skb == NULL) 627 continue; 628 629 if (curr_dev != dev || curr_net != net) { 630 /* dispatch old sublist */ 631 if (!list_empty(&sublist)) 632 ip_sublist_rcv(&sublist, curr_dev, curr_net); 633 /* start new sublist */ 634 INIT_LIST_HEAD(&sublist); 635 curr_dev = dev; 636 curr_net = net; 637 } 638 list_add_tail(&skb->list, &sublist); 639 } 640 /* dispatch final sublist */ 641 if (!list_empty(&sublist)) 642 ip_sublist_rcv(&sublist, curr_dev, curr_net); 643 } 644