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) output module. 7 * 8 * Version: $Id: ip_output.c,v 1.100 2002/02/01 22:01:03 davem Exp $ 9 * 10 * Authors: Ross Biro 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 * Hirokazu Takahashi, <taka@valinux.co.jp> 19 * 20 * See ip_input.c for original log 21 * 22 * Fixes: 23 * Alan Cox : Missing nonblock feature in ip_build_xmit. 24 * Mike Kilburn : htons() missing in ip_build_xmit. 25 * Bradford Johnson: Fix faulty handling of some frames when 26 * no route is found. 27 * Alexander Demenshin: Missing sk/skb free in ip_queue_xmit 28 * (in case if packet not accepted by 29 * output firewall rules) 30 * Mike McLagan : Routing by source 31 * Alexey Kuznetsov: use new route cache 32 * Andi Kleen: Fix broken PMTU recovery and remove 33 * some redundant tests. 34 * Vitaly E. Lavrov : Transparent proxy revived after year coma. 35 * Andi Kleen : Replace ip_reply with ip_send_reply. 36 * Andi Kleen : Split fast and slow ip_build_xmit path 37 * for decreased register pressure on x86 38 * and more readibility. 39 * Marc Boucher : When call_out_firewall returns FW_QUEUE, 40 * silently drop skb instead of failing with -EPERM. 41 * Detlev Wengorz : Copy protocol for fragments. 42 * Hirokazu Takahashi: HW checksumming for outgoing UDP 43 * datagrams. 44 * Hirokazu Takahashi: sendfile() on UDP works now. 45 */ 46 47 #include <asm/uaccess.h> 48 #include <asm/system.h> 49 #include <linux/module.h> 50 #include <linux/types.h> 51 #include <linux/kernel.h> 52 #include <linux/sched.h> 53 #include <linux/mm.h> 54 #include <linux/string.h> 55 #include <linux/errno.h> 56 #include <linux/highmem.h> 57 58 #include <linux/socket.h> 59 #include <linux/sockios.h> 60 #include <linux/in.h> 61 #include <linux/inet.h> 62 #include <linux/netdevice.h> 63 #include <linux/etherdevice.h> 64 #include <linux/proc_fs.h> 65 #include <linux/stat.h> 66 #include <linux/init.h> 67 68 #include <net/snmp.h> 69 #include <net/ip.h> 70 #include <net/protocol.h> 71 #include <net/route.h> 72 #include <net/xfrm.h> 73 #include <linux/skbuff.h> 74 #include <net/sock.h> 75 #include <net/arp.h> 76 #include <net/icmp.h> 77 #include <net/checksum.h> 78 #include <net/inetpeer.h> 79 #include <net/checksum.h> 80 #include <linux/igmp.h> 81 #include <linux/netfilter_ipv4.h> 82 #include <linux/netfilter_bridge.h> 83 #include <linux/mroute.h> 84 #include <linux/netlink.h> 85 #include <linux/tcp.h> 86 87 int sysctl_ip_default_ttl __read_mostly = IPDEFTTL; 88 89 /* Generate a checksum for an outgoing IP datagram. */ 90 __inline__ void ip_send_check(struct iphdr *iph) 91 { 92 iph->check = 0; 93 iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl); 94 } 95 96 /* dev_loopback_xmit for use with netfilter. */ 97 static int ip_dev_loopback_xmit(struct sk_buff *newskb) 98 { 99 newskb->mac.raw = newskb->data; 100 __skb_pull(newskb, newskb->nh.raw - newskb->data); 101 newskb->pkt_type = PACKET_LOOPBACK; 102 newskb->ip_summed = CHECKSUM_UNNECESSARY; 103 BUG_TRAP(newskb->dst); 104 netif_rx(newskb); 105 return 0; 106 } 107 108 static inline int ip_select_ttl(struct inet_sock *inet, struct dst_entry *dst) 109 { 110 int ttl = inet->uc_ttl; 111 112 if (ttl < 0) 113 ttl = dst_metric(dst, RTAX_HOPLIMIT); 114 return ttl; 115 } 116 117 /* 118 * Add an ip header to a skbuff and send it out. 119 * 120 */ 121 int ip_build_and_send_pkt(struct sk_buff *skb, struct sock *sk, 122 __be32 saddr, __be32 daddr, struct ip_options *opt) 123 { 124 struct inet_sock *inet = inet_sk(sk); 125 struct rtable *rt = (struct rtable *)skb->dst; 126 struct iphdr *iph; 127 128 /* Build the IP header. */ 129 if (opt) 130 iph=(struct iphdr *)skb_push(skb,sizeof(struct iphdr) + opt->optlen); 131 else 132 iph=(struct iphdr *)skb_push(skb,sizeof(struct iphdr)); 133 134 iph->version = 4; 135 iph->ihl = 5; 136 iph->tos = inet->tos; 137 if (ip_dont_fragment(sk, &rt->u.dst)) 138 iph->frag_off = htons(IP_DF); 139 else 140 iph->frag_off = 0; 141 iph->ttl = ip_select_ttl(inet, &rt->u.dst); 142 iph->daddr = rt->rt_dst; 143 iph->saddr = rt->rt_src; 144 iph->protocol = sk->sk_protocol; 145 iph->tot_len = htons(skb->len); 146 ip_select_ident(iph, &rt->u.dst, sk); 147 skb->nh.iph = iph; 148 149 if (opt && opt->optlen) { 150 iph->ihl += opt->optlen>>2; 151 ip_options_build(skb, opt, daddr, rt, 0); 152 } 153 ip_send_check(iph); 154 155 skb->priority = sk->sk_priority; 156 157 /* Send it out. */ 158 return NF_HOOK(PF_INET, NF_IP_LOCAL_OUT, skb, NULL, rt->u.dst.dev, 159 dst_output); 160 } 161 162 EXPORT_SYMBOL_GPL(ip_build_and_send_pkt); 163 164 static inline int ip_finish_output2(struct sk_buff *skb) 165 { 166 struct dst_entry *dst = skb->dst; 167 struct net_device *dev = dst->dev; 168 int hh_len = LL_RESERVED_SPACE(dev); 169 170 /* Be paranoid, rather than too clever. */ 171 if (unlikely(skb_headroom(skb) < hh_len && dev->hard_header)) { 172 struct sk_buff *skb2; 173 174 skb2 = skb_realloc_headroom(skb, LL_RESERVED_SPACE(dev)); 175 if (skb2 == NULL) { 176 kfree_skb(skb); 177 return -ENOMEM; 178 } 179 if (skb->sk) 180 skb_set_owner_w(skb2, skb->sk); 181 kfree_skb(skb); 182 skb = skb2; 183 } 184 185 if (dst->hh) 186 return neigh_hh_output(dst->hh, skb); 187 else if (dst->neighbour) 188 return dst->neighbour->output(skb); 189 190 if (net_ratelimit()) 191 printk(KERN_DEBUG "ip_finish_output2: No header cache and no neighbour!\n"); 192 kfree_skb(skb); 193 return -EINVAL; 194 } 195 196 static inline int ip_finish_output(struct sk_buff *skb) 197 { 198 #if defined(CONFIG_NETFILTER) && defined(CONFIG_XFRM) 199 /* Policy lookup after SNAT yielded a new policy */ 200 if (skb->dst->xfrm != NULL) { 201 IPCB(skb)->flags |= IPSKB_REROUTED; 202 return dst_output(skb); 203 } 204 #endif 205 if (skb->len > dst_mtu(skb->dst) && !skb_is_gso(skb)) 206 return ip_fragment(skb, ip_finish_output2); 207 else 208 return ip_finish_output2(skb); 209 } 210 211 int ip_mc_output(struct sk_buff *skb) 212 { 213 struct sock *sk = skb->sk; 214 struct rtable *rt = (struct rtable*)skb->dst; 215 struct net_device *dev = rt->u.dst.dev; 216 217 /* 218 * If the indicated interface is up and running, send the packet. 219 */ 220 IP_INC_STATS(IPSTATS_MIB_OUTREQUESTS); 221 222 skb->dev = dev; 223 skb->protocol = htons(ETH_P_IP); 224 225 /* 226 * Multicasts are looped back for other local users 227 */ 228 229 if (rt->rt_flags&RTCF_MULTICAST) { 230 if ((!sk || inet_sk(sk)->mc_loop) 231 #ifdef CONFIG_IP_MROUTE 232 /* Small optimization: do not loopback not local frames, 233 which returned after forwarding; they will be dropped 234 by ip_mr_input in any case. 235 Note, that local frames are looped back to be delivered 236 to local recipients. 237 238 This check is duplicated in ip_mr_input at the moment. 239 */ 240 && ((rt->rt_flags&RTCF_LOCAL) || !(IPCB(skb)->flags&IPSKB_FORWARDED)) 241 #endif 242 ) { 243 struct sk_buff *newskb = skb_clone(skb, GFP_ATOMIC); 244 if (newskb) 245 NF_HOOK(PF_INET, NF_IP_POST_ROUTING, newskb, NULL, 246 newskb->dev, 247 ip_dev_loopback_xmit); 248 } 249 250 /* Multicasts with ttl 0 must not go beyond the host */ 251 252 if (skb->nh.iph->ttl == 0) { 253 kfree_skb(skb); 254 return 0; 255 } 256 } 257 258 if (rt->rt_flags&RTCF_BROADCAST) { 259 struct sk_buff *newskb = skb_clone(skb, GFP_ATOMIC); 260 if (newskb) 261 NF_HOOK(PF_INET, NF_IP_POST_ROUTING, newskb, NULL, 262 newskb->dev, ip_dev_loopback_xmit); 263 } 264 265 return NF_HOOK_COND(PF_INET, NF_IP_POST_ROUTING, skb, NULL, skb->dev, 266 ip_finish_output, 267 !(IPCB(skb)->flags & IPSKB_REROUTED)); 268 } 269 270 int ip_output(struct sk_buff *skb) 271 { 272 struct net_device *dev = skb->dst->dev; 273 274 IP_INC_STATS(IPSTATS_MIB_OUTREQUESTS); 275 276 skb->dev = dev; 277 skb->protocol = htons(ETH_P_IP); 278 279 return NF_HOOK_COND(PF_INET, NF_IP_POST_ROUTING, skb, NULL, dev, 280 ip_finish_output, 281 !(IPCB(skb)->flags & IPSKB_REROUTED)); 282 } 283 284 int ip_queue_xmit(struct sk_buff *skb, int ipfragok) 285 { 286 struct sock *sk = skb->sk; 287 struct inet_sock *inet = inet_sk(sk); 288 struct ip_options *opt = inet->opt; 289 struct rtable *rt; 290 struct iphdr *iph; 291 292 /* Skip all of this if the packet is already routed, 293 * f.e. by something like SCTP. 294 */ 295 rt = (struct rtable *) skb->dst; 296 if (rt != NULL) 297 goto packet_routed; 298 299 /* Make sure we can route this packet. */ 300 rt = (struct rtable *)__sk_dst_check(sk, 0); 301 if (rt == NULL) { 302 __be32 daddr; 303 304 /* Use correct destination address if we have options. */ 305 daddr = inet->daddr; 306 if(opt && opt->srr) 307 daddr = opt->faddr; 308 309 { 310 struct flowi fl = { .oif = sk->sk_bound_dev_if, 311 .nl_u = { .ip4_u = 312 { .daddr = daddr, 313 .saddr = inet->saddr, 314 .tos = RT_CONN_FLAGS(sk) } }, 315 .proto = sk->sk_protocol, 316 .uli_u = { .ports = 317 { .sport = inet->sport, 318 .dport = inet->dport } } }; 319 320 /* If this fails, retransmit mechanism of transport layer will 321 * keep trying until route appears or the connection times 322 * itself out. 323 */ 324 security_sk_classify_flow(sk, &fl); 325 if (ip_route_output_flow(&rt, &fl, sk, 0)) 326 goto no_route; 327 } 328 sk_setup_caps(sk, &rt->u.dst); 329 } 330 skb->dst = dst_clone(&rt->u.dst); 331 332 packet_routed: 333 if (opt && opt->is_strictroute && rt->rt_dst != rt->rt_gateway) 334 goto no_route; 335 336 /* OK, we know where to send it, allocate and build IP header. */ 337 iph = (struct iphdr *) skb_push(skb, sizeof(struct iphdr) + (opt ? opt->optlen : 0)); 338 *((__be16 *)iph) = htons((4 << 12) | (5 << 8) | (inet->tos & 0xff)); 339 iph->tot_len = htons(skb->len); 340 if (ip_dont_fragment(sk, &rt->u.dst) && !ipfragok) 341 iph->frag_off = htons(IP_DF); 342 else 343 iph->frag_off = 0; 344 iph->ttl = ip_select_ttl(inet, &rt->u.dst); 345 iph->protocol = sk->sk_protocol; 346 iph->saddr = rt->rt_src; 347 iph->daddr = rt->rt_dst; 348 skb->nh.iph = iph; 349 /* Transport layer set skb->h.foo itself. */ 350 351 if (opt && opt->optlen) { 352 iph->ihl += opt->optlen >> 2; 353 ip_options_build(skb, opt, inet->daddr, rt, 0); 354 } 355 356 ip_select_ident_more(iph, &rt->u.dst, sk, 357 (skb_shinfo(skb)->gso_segs ?: 1) - 1); 358 359 /* Add an IP checksum. */ 360 ip_send_check(iph); 361 362 skb->priority = sk->sk_priority; 363 364 return NF_HOOK(PF_INET, NF_IP_LOCAL_OUT, skb, NULL, rt->u.dst.dev, 365 dst_output); 366 367 no_route: 368 IP_INC_STATS(IPSTATS_MIB_OUTNOROUTES); 369 kfree_skb(skb); 370 return -EHOSTUNREACH; 371 } 372 373 374 static void ip_copy_metadata(struct sk_buff *to, struct sk_buff *from) 375 { 376 to->pkt_type = from->pkt_type; 377 to->priority = from->priority; 378 to->protocol = from->protocol; 379 dst_release(to->dst); 380 to->dst = dst_clone(from->dst); 381 to->dev = from->dev; 382 to->mark = from->mark; 383 384 /* Copy the flags to each fragment. */ 385 IPCB(to)->flags = IPCB(from)->flags; 386 387 #ifdef CONFIG_NET_SCHED 388 to->tc_index = from->tc_index; 389 #endif 390 #ifdef CONFIG_NETFILTER 391 /* Connection association is same as pre-frag packet */ 392 nf_conntrack_put(to->nfct); 393 to->nfct = from->nfct; 394 nf_conntrack_get(to->nfct); 395 to->nfctinfo = from->nfctinfo; 396 #if defined(CONFIG_IP_VS) || defined(CONFIG_IP_VS_MODULE) 397 to->ipvs_property = from->ipvs_property; 398 #endif 399 #ifdef CONFIG_BRIDGE_NETFILTER 400 nf_bridge_put(to->nf_bridge); 401 to->nf_bridge = from->nf_bridge; 402 nf_bridge_get(to->nf_bridge); 403 #endif 404 #endif 405 skb_copy_secmark(to, from); 406 } 407 408 /* 409 * This IP datagram is too large to be sent in one piece. Break it up into 410 * smaller pieces (each of size equal to IP header plus 411 * a block of the data of the original IP data part) that will yet fit in a 412 * single device frame, and queue such a frame for sending. 413 */ 414 415 int ip_fragment(struct sk_buff *skb, int (*output)(struct sk_buff*)) 416 { 417 struct iphdr *iph; 418 int raw = 0; 419 int ptr; 420 struct net_device *dev; 421 struct sk_buff *skb2; 422 unsigned int mtu, hlen, left, len, ll_rs, pad; 423 int offset; 424 __be16 not_last_frag; 425 struct rtable *rt = (struct rtable*)skb->dst; 426 int err = 0; 427 428 dev = rt->u.dst.dev; 429 430 /* 431 * Point into the IP datagram header. 432 */ 433 434 iph = skb->nh.iph; 435 436 if (unlikely((iph->frag_off & htons(IP_DF)) && !skb->local_df)) { 437 IP_INC_STATS(IPSTATS_MIB_FRAGFAILS); 438 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, 439 htonl(dst_mtu(&rt->u.dst))); 440 kfree_skb(skb); 441 return -EMSGSIZE; 442 } 443 444 /* 445 * Setup starting values. 446 */ 447 448 hlen = iph->ihl * 4; 449 mtu = dst_mtu(&rt->u.dst) - hlen; /* Size of data space */ 450 IPCB(skb)->flags |= IPSKB_FRAG_COMPLETE; 451 452 /* When frag_list is given, use it. First, check its validity: 453 * some transformers could create wrong frag_list or break existing 454 * one, it is not prohibited. In this case fall back to copying. 455 * 456 * LATER: this step can be merged to real generation of fragments, 457 * we can switch to copy when see the first bad fragment. 458 */ 459 if (skb_shinfo(skb)->frag_list) { 460 struct sk_buff *frag; 461 int first_len = skb_pagelen(skb); 462 463 if (first_len - hlen > mtu || 464 ((first_len - hlen) & 7) || 465 (iph->frag_off & htons(IP_MF|IP_OFFSET)) || 466 skb_cloned(skb)) 467 goto slow_path; 468 469 for (frag = skb_shinfo(skb)->frag_list; frag; frag = frag->next) { 470 /* Correct geometry. */ 471 if (frag->len > mtu || 472 ((frag->len & 7) && frag->next) || 473 skb_headroom(frag) < hlen) 474 goto slow_path; 475 476 /* Partially cloned skb? */ 477 if (skb_shared(frag)) 478 goto slow_path; 479 480 BUG_ON(frag->sk); 481 if (skb->sk) { 482 sock_hold(skb->sk); 483 frag->sk = skb->sk; 484 frag->destructor = sock_wfree; 485 skb->truesize -= frag->truesize; 486 } 487 } 488 489 /* Everything is OK. Generate! */ 490 491 err = 0; 492 offset = 0; 493 frag = skb_shinfo(skb)->frag_list; 494 skb_shinfo(skb)->frag_list = NULL; 495 skb->data_len = first_len - skb_headlen(skb); 496 skb->len = first_len; 497 iph->tot_len = htons(first_len); 498 iph->frag_off = htons(IP_MF); 499 ip_send_check(iph); 500 501 for (;;) { 502 /* Prepare header of the next frame, 503 * before previous one went down. */ 504 if (frag) { 505 frag->ip_summed = CHECKSUM_NONE; 506 frag->h.raw = frag->data; 507 frag->nh.raw = __skb_push(frag, hlen); 508 memcpy(frag->nh.raw, iph, hlen); 509 iph = frag->nh.iph; 510 iph->tot_len = htons(frag->len); 511 ip_copy_metadata(frag, skb); 512 if (offset == 0) 513 ip_options_fragment(frag); 514 offset += skb->len - hlen; 515 iph->frag_off = htons(offset>>3); 516 if (frag->next != NULL) 517 iph->frag_off |= htons(IP_MF); 518 /* Ready, complete checksum */ 519 ip_send_check(iph); 520 } 521 522 err = output(skb); 523 524 if (!err) 525 IP_INC_STATS(IPSTATS_MIB_FRAGCREATES); 526 if (err || !frag) 527 break; 528 529 skb = frag; 530 frag = skb->next; 531 skb->next = NULL; 532 } 533 534 if (err == 0) { 535 IP_INC_STATS(IPSTATS_MIB_FRAGOKS); 536 return 0; 537 } 538 539 while (frag) { 540 skb = frag->next; 541 kfree_skb(frag); 542 frag = skb; 543 } 544 IP_INC_STATS(IPSTATS_MIB_FRAGFAILS); 545 return err; 546 } 547 548 slow_path: 549 left = skb->len - hlen; /* Space per frame */ 550 ptr = raw + hlen; /* Where to start from */ 551 552 /* for bridged IP traffic encapsulated inside f.e. a vlan header, 553 * we need to make room for the encapsulating header 554 */ 555 pad = nf_bridge_pad(skb); 556 ll_rs = LL_RESERVED_SPACE_EXTRA(rt->u.dst.dev, pad); 557 mtu -= pad; 558 559 /* 560 * Fragment the datagram. 561 */ 562 563 offset = (ntohs(iph->frag_off) & IP_OFFSET) << 3; 564 not_last_frag = iph->frag_off & htons(IP_MF); 565 566 /* 567 * Keep copying data until we run out. 568 */ 569 570 while(left > 0) { 571 len = left; 572 /* IF: it doesn't fit, use 'mtu' - the data space left */ 573 if (len > mtu) 574 len = mtu; 575 /* IF: we are not sending upto and including the packet end 576 then align the next start on an eight byte boundary */ 577 if (len < left) { 578 len &= ~7; 579 } 580 /* 581 * Allocate buffer. 582 */ 583 584 if ((skb2 = alloc_skb(len+hlen+ll_rs, GFP_ATOMIC)) == NULL) { 585 NETDEBUG(KERN_INFO "IP: frag: no memory for new fragment!\n"); 586 err = -ENOMEM; 587 goto fail; 588 } 589 590 /* 591 * Set up data on packet 592 */ 593 594 ip_copy_metadata(skb2, skb); 595 skb_reserve(skb2, ll_rs); 596 skb_put(skb2, len + hlen); 597 skb2->nh.raw = skb2->data; 598 skb2->h.raw = skb2->data + hlen; 599 600 /* 601 * Charge the memory for the fragment to any owner 602 * it might possess 603 */ 604 605 if (skb->sk) 606 skb_set_owner_w(skb2, skb->sk); 607 608 /* 609 * Copy the packet header into the new buffer. 610 */ 611 612 memcpy(skb2->nh.raw, skb->data, hlen); 613 614 /* 615 * Copy a block of the IP datagram. 616 */ 617 if (skb_copy_bits(skb, ptr, skb2->h.raw, len)) 618 BUG(); 619 left -= len; 620 621 /* 622 * Fill in the new header fields. 623 */ 624 iph = skb2->nh.iph; 625 iph->frag_off = htons((offset >> 3)); 626 627 /* ANK: dirty, but effective trick. Upgrade options only if 628 * the segment to be fragmented was THE FIRST (otherwise, 629 * options are already fixed) and make it ONCE 630 * on the initial skb, so that all the following fragments 631 * will inherit fixed options. 632 */ 633 if (offset == 0) 634 ip_options_fragment(skb); 635 636 /* 637 * Added AC : If we are fragmenting a fragment that's not the 638 * last fragment then keep MF on each bit 639 */ 640 if (left > 0 || not_last_frag) 641 iph->frag_off |= htons(IP_MF); 642 ptr += len; 643 offset += len; 644 645 /* 646 * Put this fragment into the sending queue. 647 */ 648 iph->tot_len = htons(len + hlen); 649 650 ip_send_check(iph); 651 652 err = output(skb2); 653 if (err) 654 goto fail; 655 656 IP_INC_STATS(IPSTATS_MIB_FRAGCREATES); 657 } 658 kfree_skb(skb); 659 IP_INC_STATS(IPSTATS_MIB_FRAGOKS); 660 return err; 661 662 fail: 663 kfree_skb(skb); 664 IP_INC_STATS(IPSTATS_MIB_FRAGFAILS); 665 return err; 666 } 667 668 EXPORT_SYMBOL(ip_fragment); 669 670 int 671 ip_generic_getfrag(void *from, char *to, int offset, int len, int odd, struct sk_buff *skb) 672 { 673 struct iovec *iov = from; 674 675 if (skb->ip_summed == CHECKSUM_PARTIAL) { 676 if (memcpy_fromiovecend(to, iov, offset, len) < 0) 677 return -EFAULT; 678 } else { 679 __wsum csum = 0; 680 if (csum_partial_copy_fromiovecend(to, iov, offset, len, &csum) < 0) 681 return -EFAULT; 682 skb->csum = csum_block_add(skb->csum, csum, odd); 683 } 684 return 0; 685 } 686 687 static inline __wsum 688 csum_page(struct page *page, int offset, int copy) 689 { 690 char *kaddr; 691 __wsum csum; 692 kaddr = kmap(page); 693 csum = csum_partial(kaddr + offset, copy, 0); 694 kunmap(page); 695 return csum; 696 } 697 698 static inline int ip_ufo_append_data(struct sock *sk, 699 int getfrag(void *from, char *to, int offset, int len, 700 int odd, struct sk_buff *skb), 701 void *from, int length, int hh_len, int fragheaderlen, 702 int transhdrlen, int mtu,unsigned int flags) 703 { 704 struct sk_buff *skb; 705 int err; 706 707 /* There is support for UDP fragmentation offload by network 708 * device, so create one single skb packet containing complete 709 * udp datagram 710 */ 711 if ((skb = skb_peek_tail(&sk->sk_write_queue)) == NULL) { 712 skb = sock_alloc_send_skb(sk, 713 hh_len + fragheaderlen + transhdrlen + 20, 714 (flags & MSG_DONTWAIT), &err); 715 716 if (skb == NULL) 717 return err; 718 719 /* reserve space for Hardware header */ 720 skb_reserve(skb, hh_len); 721 722 /* create space for UDP/IP header */ 723 skb_put(skb,fragheaderlen + transhdrlen); 724 725 /* initialize network header pointer */ 726 skb->nh.raw = skb->data; 727 728 /* initialize protocol header pointer */ 729 skb->h.raw = skb->data + fragheaderlen; 730 731 skb->ip_summed = CHECKSUM_PARTIAL; 732 skb->csum = 0; 733 sk->sk_sndmsg_off = 0; 734 } 735 736 err = skb_append_datato_frags(sk,skb, getfrag, from, 737 (length - transhdrlen)); 738 if (!err) { 739 /* specify the length of each IP datagram fragment*/ 740 skb_shinfo(skb)->gso_size = mtu - fragheaderlen; 741 skb_shinfo(skb)->gso_type = SKB_GSO_UDP; 742 __skb_queue_tail(&sk->sk_write_queue, skb); 743 744 return 0; 745 } 746 /* There is not enough support do UFO , 747 * so follow normal path 748 */ 749 kfree_skb(skb); 750 return err; 751 } 752 753 /* 754 * ip_append_data() and ip_append_page() can make one large IP datagram 755 * from many pieces of data. Each pieces will be holded on the socket 756 * until ip_push_pending_frames() is called. Each piece can be a page 757 * or non-page data. 758 * 759 * Not only UDP, other transport protocols - e.g. raw sockets - can use 760 * this interface potentially. 761 * 762 * LATER: length must be adjusted by pad at tail, when it is required. 763 */ 764 int ip_append_data(struct sock *sk, 765 int getfrag(void *from, char *to, int offset, int len, 766 int odd, struct sk_buff *skb), 767 void *from, int length, int transhdrlen, 768 struct ipcm_cookie *ipc, struct rtable *rt, 769 unsigned int flags) 770 { 771 struct inet_sock *inet = inet_sk(sk); 772 struct sk_buff *skb; 773 774 struct ip_options *opt = NULL; 775 int hh_len; 776 int exthdrlen; 777 int mtu; 778 int copy; 779 int err; 780 int offset = 0; 781 unsigned int maxfraglen, fragheaderlen; 782 int csummode = CHECKSUM_NONE; 783 784 if (flags&MSG_PROBE) 785 return 0; 786 787 if (skb_queue_empty(&sk->sk_write_queue)) { 788 /* 789 * setup for corking. 790 */ 791 opt = ipc->opt; 792 if (opt) { 793 if (inet->cork.opt == NULL) { 794 inet->cork.opt = kmalloc(sizeof(struct ip_options) + 40, sk->sk_allocation); 795 if (unlikely(inet->cork.opt == NULL)) 796 return -ENOBUFS; 797 } 798 memcpy(inet->cork.opt, opt, sizeof(struct ip_options)+opt->optlen); 799 inet->cork.flags |= IPCORK_OPT; 800 inet->cork.addr = ipc->addr; 801 } 802 dst_hold(&rt->u.dst); 803 inet->cork.fragsize = mtu = dst_mtu(rt->u.dst.path); 804 inet->cork.rt = rt; 805 inet->cork.length = 0; 806 sk->sk_sndmsg_page = NULL; 807 sk->sk_sndmsg_off = 0; 808 if ((exthdrlen = rt->u.dst.header_len) != 0) { 809 length += exthdrlen; 810 transhdrlen += exthdrlen; 811 } 812 } else { 813 rt = inet->cork.rt; 814 if (inet->cork.flags & IPCORK_OPT) 815 opt = inet->cork.opt; 816 817 transhdrlen = 0; 818 exthdrlen = 0; 819 mtu = inet->cork.fragsize; 820 } 821 hh_len = LL_RESERVED_SPACE(rt->u.dst.dev); 822 823 fragheaderlen = sizeof(struct iphdr) + (opt ? opt->optlen : 0); 824 maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen; 825 826 if (inet->cork.length + length > 0xFFFF - fragheaderlen) { 827 ip_local_error(sk, EMSGSIZE, rt->rt_dst, inet->dport, mtu-exthdrlen); 828 return -EMSGSIZE; 829 } 830 831 /* 832 * transhdrlen > 0 means that this is the first fragment and we wish 833 * it won't be fragmented in the future. 834 */ 835 if (transhdrlen && 836 length + fragheaderlen <= mtu && 837 rt->u.dst.dev->features & NETIF_F_ALL_CSUM && 838 !exthdrlen) 839 csummode = CHECKSUM_PARTIAL; 840 841 inet->cork.length += length; 842 if (((length > mtu) && (sk->sk_protocol == IPPROTO_UDP)) && 843 (rt->u.dst.dev->features & NETIF_F_UFO)) { 844 845 err = ip_ufo_append_data(sk, getfrag, from, length, hh_len, 846 fragheaderlen, transhdrlen, mtu, 847 flags); 848 if (err) 849 goto error; 850 return 0; 851 } 852 853 /* So, what's going on in the loop below? 854 * 855 * We use calculated fragment length to generate chained skb, 856 * each of segments is IP fragment ready for sending to network after 857 * adding appropriate IP header. 858 */ 859 860 if ((skb = skb_peek_tail(&sk->sk_write_queue)) == NULL) 861 goto alloc_new_skb; 862 863 while (length > 0) { 864 /* Check if the remaining data fits into current packet. */ 865 copy = mtu - skb->len; 866 if (copy < length) 867 copy = maxfraglen - skb->len; 868 if (copy <= 0) { 869 char *data; 870 unsigned int datalen; 871 unsigned int fraglen; 872 unsigned int fraggap; 873 unsigned int alloclen; 874 struct sk_buff *skb_prev; 875 alloc_new_skb: 876 skb_prev = skb; 877 if (skb_prev) 878 fraggap = skb_prev->len - maxfraglen; 879 else 880 fraggap = 0; 881 882 /* 883 * If remaining data exceeds the mtu, 884 * we know we need more fragment(s). 885 */ 886 datalen = length + fraggap; 887 if (datalen > mtu - fragheaderlen) 888 datalen = maxfraglen - fragheaderlen; 889 fraglen = datalen + fragheaderlen; 890 891 if ((flags & MSG_MORE) && 892 !(rt->u.dst.dev->features&NETIF_F_SG)) 893 alloclen = mtu; 894 else 895 alloclen = datalen + fragheaderlen; 896 897 /* The last fragment gets additional space at tail. 898 * Note, with MSG_MORE we overallocate on fragments, 899 * because we have no idea what fragment will be 900 * the last. 901 */ 902 if (datalen == length + fraggap) 903 alloclen += rt->u.dst.trailer_len; 904 905 if (transhdrlen) { 906 skb = sock_alloc_send_skb(sk, 907 alloclen + hh_len + 15, 908 (flags & MSG_DONTWAIT), &err); 909 } else { 910 skb = NULL; 911 if (atomic_read(&sk->sk_wmem_alloc) <= 912 2 * sk->sk_sndbuf) 913 skb = sock_wmalloc(sk, 914 alloclen + hh_len + 15, 1, 915 sk->sk_allocation); 916 if (unlikely(skb == NULL)) 917 err = -ENOBUFS; 918 } 919 if (skb == NULL) 920 goto error; 921 922 /* 923 * Fill in the control structures 924 */ 925 skb->ip_summed = csummode; 926 skb->csum = 0; 927 skb_reserve(skb, hh_len); 928 929 /* 930 * Find where to start putting bytes. 931 */ 932 data = skb_put(skb, fraglen); 933 skb->nh.raw = data + exthdrlen; 934 data += fragheaderlen; 935 skb->h.raw = data + exthdrlen; 936 937 if (fraggap) { 938 skb->csum = skb_copy_and_csum_bits( 939 skb_prev, maxfraglen, 940 data + transhdrlen, fraggap, 0); 941 skb_prev->csum = csum_sub(skb_prev->csum, 942 skb->csum); 943 data += fraggap; 944 pskb_trim_unique(skb_prev, maxfraglen); 945 } 946 947 copy = datalen - transhdrlen - fraggap; 948 if (copy > 0 && getfrag(from, data + transhdrlen, offset, copy, fraggap, skb) < 0) { 949 err = -EFAULT; 950 kfree_skb(skb); 951 goto error; 952 } 953 954 offset += copy; 955 length -= datalen - fraggap; 956 transhdrlen = 0; 957 exthdrlen = 0; 958 csummode = CHECKSUM_NONE; 959 960 /* 961 * Put the packet on the pending queue. 962 */ 963 __skb_queue_tail(&sk->sk_write_queue, skb); 964 continue; 965 } 966 967 if (copy > length) 968 copy = length; 969 970 if (!(rt->u.dst.dev->features&NETIF_F_SG)) { 971 unsigned int off; 972 973 off = skb->len; 974 if (getfrag(from, skb_put(skb, copy), 975 offset, copy, off, skb) < 0) { 976 __skb_trim(skb, off); 977 err = -EFAULT; 978 goto error; 979 } 980 } else { 981 int i = skb_shinfo(skb)->nr_frags; 982 skb_frag_t *frag = &skb_shinfo(skb)->frags[i-1]; 983 struct page *page = sk->sk_sndmsg_page; 984 int off = sk->sk_sndmsg_off; 985 unsigned int left; 986 987 if (page && (left = PAGE_SIZE - off) > 0) { 988 if (copy >= left) 989 copy = left; 990 if (page != frag->page) { 991 if (i == MAX_SKB_FRAGS) { 992 err = -EMSGSIZE; 993 goto error; 994 } 995 get_page(page); 996 skb_fill_page_desc(skb, i, page, sk->sk_sndmsg_off, 0); 997 frag = &skb_shinfo(skb)->frags[i]; 998 } 999 } else if (i < MAX_SKB_FRAGS) { 1000 if (copy > PAGE_SIZE) 1001 copy = PAGE_SIZE; 1002 page = alloc_pages(sk->sk_allocation, 0); 1003 if (page == NULL) { 1004 err = -ENOMEM; 1005 goto error; 1006 } 1007 sk->sk_sndmsg_page = page; 1008 sk->sk_sndmsg_off = 0; 1009 1010 skb_fill_page_desc(skb, i, page, 0, 0); 1011 frag = &skb_shinfo(skb)->frags[i]; 1012 skb->truesize += PAGE_SIZE; 1013 atomic_add(PAGE_SIZE, &sk->sk_wmem_alloc); 1014 } else { 1015 err = -EMSGSIZE; 1016 goto error; 1017 } 1018 if (getfrag(from, page_address(frag->page)+frag->page_offset+frag->size, offset, copy, skb->len, skb) < 0) { 1019 err = -EFAULT; 1020 goto error; 1021 } 1022 sk->sk_sndmsg_off += copy; 1023 frag->size += copy; 1024 skb->len += copy; 1025 skb->data_len += copy; 1026 } 1027 offset += copy; 1028 length -= copy; 1029 } 1030 1031 return 0; 1032 1033 error: 1034 inet->cork.length -= length; 1035 IP_INC_STATS(IPSTATS_MIB_OUTDISCARDS); 1036 return err; 1037 } 1038 1039 ssize_t ip_append_page(struct sock *sk, struct page *page, 1040 int offset, size_t size, int flags) 1041 { 1042 struct inet_sock *inet = inet_sk(sk); 1043 struct sk_buff *skb; 1044 struct rtable *rt; 1045 struct ip_options *opt = NULL; 1046 int hh_len; 1047 int mtu; 1048 int len; 1049 int err; 1050 unsigned int maxfraglen, fragheaderlen, fraggap; 1051 1052 if (inet->hdrincl) 1053 return -EPERM; 1054 1055 if (flags&MSG_PROBE) 1056 return 0; 1057 1058 if (skb_queue_empty(&sk->sk_write_queue)) 1059 return -EINVAL; 1060 1061 rt = inet->cork.rt; 1062 if (inet->cork.flags & IPCORK_OPT) 1063 opt = inet->cork.opt; 1064 1065 if (!(rt->u.dst.dev->features&NETIF_F_SG)) 1066 return -EOPNOTSUPP; 1067 1068 hh_len = LL_RESERVED_SPACE(rt->u.dst.dev); 1069 mtu = inet->cork.fragsize; 1070 1071 fragheaderlen = sizeof(struct iphdr) + (opt ? opt->optlen : 0); 1072 maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen; 1073 1074 if (inet->cork.length + size > 0xFFFF - fragheaderlen) { 1075 ip_local_error(sk, EMSGSIZE, rt->rt_dst, inet->dport, mtu); 1076 return -EMSGSIZE; 1077 } 1078 1079 if ((skb = skb_peek_tail(&sk->sk_write_queue)) == NULL) 1080 return -EINVAL; 1081 1082 inet->cork.length += size; 1083 if ((sk->sk_protocol == IPPROTO_UDP) && 1084 (rt->u.dst.dev->features & NETIF_F_UFO)) { 1085 skb_shinfo(skb)->gso_size = mtu - fragheaderlen; 1086 skb_shinfo(skb)->gso_type = SKB_GSO_UDP; 1087 } 1088 1089 1090 while (size > 0) { 1091 int i; 1092 1093 if (skb_is_gso(skb)) 1094 len = size; 1095 else { 1096 1097 /* Check if the remaining data fits into current packet. */ 1098 len = mtu - skb->len; 1099 if (len < size) 1100 len = maxfraglen - skb->len; 1101 } 1102 if (len <= 0) { 1103 struct sk_buff *skb_prev; 1104 char *data; 1105 struct iphdr *iph; 1106 int alloclen; 1107 1108 skb_prev = skb; 1109 fraggap = skb_prev->len - maxfraglen; 1110 1111 alloclen = fragheaderlen + hh_len + fraggap + 15; 1112 skb = sock_wmalloc(sk, alloclen, 1, sk->sk_allocation); 1113 if (unlikely(!skb)) { 1114 err = -ENOBUFS; 1115 goto error; 1116 } 1117 1118 /* 1119 * Fill in the control structures 1120 */ 1121 skb->ip_summed = CHECKSUM_NONE; 1122 skb->csum = 0; 1123 skb_reserve(skb, hh_len); 1124 1125 /* 1126 * Find where to start putting bytes. 1127 */ 1128 data = skb_put(skb, fragheaderlen + fraggap); 1129 skb->nh.iph = iph = (struct iphdr *)data; 1130 data += fragheaderlen; 1131 skb->h.raw = data; 1132 1133 if (fraggap) { 1134 skb->csum = skb_copy_and_csum_bits( 1135 skb_prev, maxfraglen, 1136 data, fraggap, 0); 1137 skb_prev->csum = csum_sub(skb_prev->csum, 1138 skb->csum); 1139 pskb_trim_unique(skb_prev, maxfraglen); 1140 } 1141 1142 /* 1143 * Put the packet on the pending queue. 1144 */ 1145 __skb_queue_tail(&sk->sk_write_queue, skb); 1146 continue; 1147 } 1148 1149 i = skb_shinfo(skb)->nr_frags; 1150 if (len > size) 1151 len = size; 1152 if (skb_can_coalesce(skb, i, page, offset)) { 1153 skb_shinfo(skb)->frags[i-1].size += len; 1154 } else if (i < MAX_SKB_FRAGS) { 1155 get_page(page); 1156 skb_fill_page_desc(skb, i, page, offset, len); 1157 } else { 1158 err = -EMSGSIZE; 1159 goto error; 1160 } 1161 1162 if (skb->ip_summed == CHECKSUM_NONE) { 1163 __wsum csum; 1164 csum = csum_page(page, offset, len); 1165 skb->csum = csum_block_add(skb->csum, csum, skb->len); 1166 } 1167 1168 skb->len += len; 1169 skb->data_len += len; 1170 offset += len; 1171 size -= len; 1172 } 1173 return 0; 1174 1175 error: 1176 inet->cork.length -= size; 1177 IP_INC_STATS(IPSTATS_MIB_OUTDISCARDS); 1178 return err; 1179 } 1180 1181 /* 1182 * Combined all pending IP fragments on the socket as one IP datagram 1183 * and push them out. 1184 */ 1185 int ip_push_pending_frames(struct sock *sk) 1186 { 1187 struct sk_buff *skb, *tmp_skb; 1188 struct sk_buff **tail_skb; 1189 struct inet_sock *inet = inet_sk(sk); 1190 struct ip_options *opt = NULL; 1191 struct rtable *rt = inet->cork.rt; 1192 struct iphdr *iph; 1193 __be16 df = 0; 1194 __u8 ttl; 1195 int err = 0; 1196 1197 if ((skb = __skb_dequeue(&sk->sk_write_queue)) == NULL) 1198 goto out; 1199 tail_skb = &(skb_shinfo(skb)->frag_list); 1200 1201 /* move skb->data to ip header from ext header */ 1202 if (skb->data < skb->nh.raw) 1203 __skb_pull(skb, skb->nh.raw - skb->data); 1204 while ((tmp_skb = __skb_dequeue(&sk->sk_write_queue)) != NULL) { 1205 __skb_pull(tmp_skb, skb->h.raw - skb->nh.raw); 1206 *tail_skb = tmp_skb; 1207 tail_skb = &(tmp_skb->next); 1208 skb->len += tmp_skb->len; 1209 skb->data_len += tmp_skb->len; 1210 skb->truesize += tmp_skb->truesize; 1211 __sock_put(tmp_skb->sk); 1212 tmp_skb->destructor = NULL; 1213 tmp_skb->sk = NULL; 1214 } 1215 1216 /* Unless user demanded real pmtu discovery (IP_PMTUDISC_DO), we allow 1217 * to fragment the frame generated here. No matter, what transforms 1218 * how transforms change size of the packet, it will come out. 1219 */ 1220 if (inet->pmtudisc != IP_PMTUDISC_DO) 1221 skb->local_df = 1; 1222 1223 /* DF bit is set when we want to see DF on outgoing frames. 1224 * If local_df is set too, we still allow to fragment this frame 1225 * locally. */ 1226 if (inet->pmtudisc == IP_PMTUDISC_DO || 1227 (skb->len <= dst_mtu(&rt->u.dst) && 1228 ip_dont_fragment(sk, &rt->u.dst))) 1229 df = htons(IP_DF); 1230 1231 if (inet->cork.flags & IPCORK_OPT) 1232 opt = inet->cork.opt; 1233 1234 if (rt->rt_type == RTN_MULTICAST) 1235 ttl = inet->mc_ttl; 1236 else 1237 ttl = ip_select_ttl(inet, &rt->u.dst); 1238 1239 iph = (struct iphdr *)skb->data; 1240 iph->version = 4; 1241 iph->ihl = 5; 1242 if (opt) { 1243 iph->ihl += opt->optlen>>2; 1244 ip_options_build(skb, opt, inet->cork.addr, rt, 0); 1245 } 1246 iph->tos = inet->tos; 1247 iph->tot_len = htons(skb->len); 1248 iph->frag_off = df; 1249 ip_select_ident(iph, &rt->u.dst, sk); 1250 iph->ttl = ttl; 1251 iph->protocol = sk->sk_protocol; 1252 iph->saddr = rt->rt_src; 1253 iph->daddr = rt->rt_dst; 1254 ip_send_check(iph); 1255 1256 skb->priority = sk->sk_priority; 1257 skb->dst = dst_clone(&rt->u.dst); 1258 1259 /* Netfilter gets whole the not fragmented skb. */ 1260 err = NF_HOOK(PF_INET, NF_IP_LOCAL_OUT, skb, NULL, 1261 skb->dst->dev, dst_output); 1262 if (err) { 1263 if (err > 0) 1264 err = inet->recverr ? net_xmit_errno(err) : 0; 1265 if (err) 1266 goto error; 1267 } 1268 1269 out: 1270 inet->cork.flags &= ~IPCORK_OPT; 1271 kfree(inet->cork.opt); 1272 inet->cork.opt = NULL; 1273 if (inet->cork.rt) { 1274 ip_rt_put(inet->cork.rt); 1275 inet->cork.rt = NULL; 1276 } 1277 return err; 1278 1279 error: 1280 IP_INC_STATS(IPSTATS_MIB_OUTDISCARDS); 1281 goto out; 1282 } 1283 1284 /* 1285 * Throw away all pending data on the socket. 1286 */ 1287 void ip_flush_pending_frames(struct sock *sk) 1288 { 1289 struct inet_sock *inet = inet_sk(sk); 1290 struct sk_buff *skb; 1291 1292 while ((skb = __skb_dequeue_tail(&sk->sk_write_queue)) != NULL) 1293 kfree_skb(skb); 1294 1295 inet->cork.flags &= ~IPCORK_OPT; 1296 kfree(inet->cork.opt); 1297 inet->cork.opt = NULL; 1298 if (inet->cork.rt) { 1299 ip_rt_put(inet->cork.rt); 1300 inet->cork.rt = NULL; 1301 } 1302 } 1303 1304 1305 /* 1306 * Fetch data from kernel space and fill in checksum if needed. 1307 */ 1308 static int ip_reply_glue_bits(void *dptr, char *to, int offset, 1309 int len, int odd, struct sk_buff *skb) 1310 { 1311 __wsum csum; 1312 1313 csum = csum_partial_copy_nocheck(dptr+offset, to, len, 0); 1314 skb->csum = csum_block_add(skb->csum, csum, odd); 1315 return 0; 1316 } 1317 1318 /* 1319 * Generic function to send a packet as reply to another packet. 1320 * Used to send TCP resets so far. ICMP should use this function too. 1321 * 1322 * Should run single threaded per socket because it uses the sock 1323 * structure to pass arguments. 1324 * 1325 * LATER: switch from ip_build_xmit to ip_append_* 1326 */ 1327 void ip_send_reply(struct sock *sk, struct sk_buff *skb, struct ip_reply_arg *arg, 1328 unsigned int len) 1329 { 1330 struct inet_sock *inet = inet_sk(sk); 1331 struct { 1332 struct ip_options opt; 1333 char data[40]; 1334 } replyopts; 1335 struct ipcm_cookie ipc; 1336 __be32 daddr; 1337 struct rtable *rt = (struct rtable*)skb->dst; 1338 1339 if (ip_options_echo(&replyopts.opt, skb)) 1340 return; 1341 1342 daddr = ipc.addr = rt->rt_src; 1343 ipc.opt = NULL; 1344 1345 if (replyopts.opt.optlen) { 1346 ipc.opt = &replyopts.opt; 1347 1348 if (ipc.opt->srr) 1349 daddr = replyopts.opt.faddr; 1350 } 1351 1352 { 1353 struct flowi fl = { .nl_u = { .ip4_u = 1354 { .daddr = daddr, 1355 .saddr = rt->rt_spec_dst, 1356 .tos = RT_TOS(skb->nh.iph->tos) } }, 1357 /* Not quite clean, but right. */ 1358 .uli_u = { .ports = 1359 { .sport = skb->h.th->dest, 1360 .dport = skb->h.th->source } }, 1361 .proto = sk->sk_protocol }; 1362 security_skb_classify_flow(skb, &fl); 1363 if (ip_route_output_key(&rt, &fl)) 1364 return; 1365 } 1366 1367 /* And let IP do all the hard work. 1368 1369 This chunk is not reenterable, hence spinlock. 1370 Note that it uses the fact, that this function is called 1371 with locally disabled BH and that sk cannot be already spinlocked. 1372 */ 1373 bh_lock_sock(sk); 1374 inet->tos = skb->nh.iph->tos; 1375 sk->sk_priority = skb->priority; 1376 sk->sk_protocol = skb->nh.iph->protocol; 1377 ip_append_data(sk, ip_reply_glue_bits, arg->iov->iov_base, len, 0, 1378 &ipc, rt, MSG_DONTWAIT); 1379 if ((skb = skb_peek(&sk->sk_write_queue)) != NULL) { 1380 if (arg->csumoffset >= 0) 1381 *((__sum16 *)skb->h.raw + arg->csumoffset) = csum_fold(csum_add(skb->csum, arg->csum)); 1382 skb->ip_summed = CHECKSUM_NONE; 1383 ip_push_pending_frames(sk); 1384 } 1385 1386 bh_unlock_sock(sk); 1387 1388 ip_rt_put(rt); 1389 } 1390 1391 void __init ip_init(void) 1392 { 1393 ip_rt_init(); 1394 inet_initpeers(); 1395 1396 #if defined(CONFIG_IP_MULTICAST) && defined(CONFIG_PROC_FS) 1397 igmp_mc_proc_init(); 1398 #endif 1399 } 1400 1401 EXPORT_SYMBOL(ip_generic_getfrag); 1402 EXPORT_SYMBOL(ip_queue_xmit); 1403 EXPORT_SYMBOL(ip_send_check); 1404