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/config.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 = 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 u32 saddr, u32 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 hh_cache *hh = dst->hh; 168 struct net_device *dev = dst->dev; 169 int hh_len = LL_RESERVED_SPACE(dev); 170 171 /* Be paranoid, rather than too clever. */ 172 if (unlikely(skb_headroom(skb) < hh_len && dev->hard_header)) { 173 struct sk_buff *skb2; 174 175 skb2 = skb_realloc_headroom(skb, LL_RESERVED_SPACE(dev)); 176 if (skb2 == NULL) { 177 kfree_skb(skb); 178 return -ENOMEM; 179 } 180 if (skb->sk) 181 skb_set_owner_w(skb2, skb->sk); 182 kfree_skb(skb); 183 skb = skb2; 184 } 185 186 if (hh) { 187 int hh_alen; 188 189 read_lock_bh(&hh->hh_lock); 190 hh_alen = HH_DATA_ALIGN(hh->hh_len); 191 memcpy(skb->data - hh_alen, hh->hh_data, hh_alen); 192 read_unlock_bh(&hh->hh_lock); 193 skb_push(skb, hh->hh_len); 194 return hh->hh_output(skb); 195 } else if (dst->neighbour) 196 return dst->neighbour->output(skb); 197 198 if (net_ratelimit()) 199 printk(KERN_DEBUG "ip_finish_output2: No header cache and no neighbour!\n"); 200 kfree_skb(skb); 201 return -EINVAL; 202 } 203 204 static inline int ip_finish_output(struct sk_buff *skb) 205 { 206 #if defined(CONFIG_NETFILTER) && defined(CONFIG_XFRM) 207 /* Policy lookup after SNAT yielded a new policy */ 208 if (skb->dst->xfrm != NULL) { 209 IPCB(skb)->flags |= IPSKB_REROUTED; 210 return dst_output(skb); 211 } 212 #endif 213 if (skb->len > dst_mtu(skb->dst) && 214 !(skb_shinfo(skb)->ufo_size || skb_shinfo(skb)->tso_size)) 215 return ip_fragment(skb, ip_finish_output2); 216 else 217 return ip_finish_output2(skb); 218 } 219 220 int ip_mc_output(struct sk_buff *skb) 221 { 222 struct sock *sk = skb->sk; 223 struct rtable *rt = (struct rtable*)skb->dst; 224 struct net_device *dev = rt->u.dst.dev; 225 226 /* 227 * If the indicated interface is up and running, send the packet. 228 */ 229 IP_INC_STATS(IPSTATS_MIB_OUTREQUESTS); 230 231 skb->dev = dev; 232 skb->protocol = htons(ETH_P_IP); 233 234 /* 235 * Multicasts are looped back for other local users 236 */ 237 238 if (rt->rt_flags&RTCF_MULTICAST) { 239 if ((!sk || inet_sk(sk)->mc_loop) 240 #ifdef CONFIG_IP_MROUTE 241 /* Small optimization: do not loopback not local frames, 242 which returned after forwarding; they will be dropped 243 by ip_mr_input in any case. 244 Note, that local frames are looped back to be delivered 245 to local recipients. 246 247 This check is duplicated in ip_mr_input at the moment. 248 */ 249 && ((rt->rt_flags&RTCF_LOCAL) || !(IPCB(skb)->flags&IPSKB_FORWARDED)) 250 #endif 251 ) { 252 struct sk_buff *newskb = skb_clone(skb, GFP_ATOMIC); 253 if (newskb) 254 NF_HOOK(PF_INET, NF_IP_POST_ROUTING, newskb, NULL, 255 newskb->dev, 256 ip_dev_loopback_xmit); 257 } 258 259 /* Multicasts with ttl 0 must not go beyond the host */ 260 261 if (skb->nh.iph->ttl == 0) { 262 kfree_skb(skb); 263 return 0; 264 } 265 } 266 267 if (rt->rt_flags&RTCF_BROADCAST) { 268 struct sk_buff *newskb = skb_clone(skb, GFP_ATOMIC); 269 if (newskb) 270 NF_HOOK(PF_INET, NF_IP_POST_ROUTING, newskb, NULL, 271 newskb->dev, ip_dev_loopback_xmit); 272 } 273 274 return NF_HOOK_COND(PF_INET, NF_IP_POST_ROUTING, skb, NULL, skb->dev, 275 ip_finish_output, 276 !(IPCB(skb)->flags & IPSKB_REROUTED)); 277 } 278 279 int ip_output(struct sk_buff *skb) 280 { 281 struct net_device *dev = skb->dst->dev; 282 283 IP_INC_STATS(IPSTATS_MIB_OUTREQUESTS); 284 285 skb->dev = dev; 286 skb->protocol = htons(ETH_P_IP); 287 288 return NF_HOOK_COND(PF_INET, NF_IP_POST_ROUTING, skb, NULL, dev, 289 ip_finish_output, 290 !(IPCB(skb)->flags & IPSKB_REROUTED)); 291 } 292 293 int ip_queue_xmit(struct sk_buff *skb, int ipfragok) 294 { 295 struct sock *sk = skb->sk; 296 struct inet_sock *inet = inet_sk(sk); 297 struct ip_options *opt = inet->opt; 298 struct rtable *rt; 299 struct iphdr *iph; 300 301 /* Skip all of this if the packet is already routed, 302 * f.e. by something like SCTP. 303 */ 304 rt = (struct rtable *) skb->dst; 305 if (rt != NULL) 306 goto packet_routed; 307 308 /* Make sure we can route this packet. */ 309 rt = (struct rtable *)__sk_dst_check(sk, 0); 310 if (rt == NULL) { 311 u32 daddr; 312 313 /* Use correct destination address if we have options. */ 314 daddr = inet->daddr; 315 if(opt && opt->srr) 316 daddr = opt->faddr; 317 318 { 319 struct flowi fl = { .oif = sk->sk_bound_dev_if, 320 .nl_u = { .ip4_u = 321 { .daddr = daddr, 322 .saddr = inet->saddr, 323 .tos = RT_CONN_FLAGS(sk) } }, 324 .proto = sk->sk_protocol, 325 .uli_u = { .ports = 326 { .sport = inet->sport, 327 .dport = inet->dport } } }; 328 329 /* If this fails, retransmit mechanism of transport layer will 330 * keep trying until route appears or the connection times 331 * itself out. 332 */ 333 if (ip_route_output_flow(&rt, &fl, sk, 0)) 334 goto no_route; 335 } 336 sk_setup_caps(sk, &rt->u.dst); 337 } 338 skb->dst = dst_clone(&rt->u.dst); 339 340 packet_routed: 341 if (opt && opt->is_strictroute && rt->rt_dst != rt->rt_gateway) 342 goto no_route; 343 344 /* OK, we know where to send it, allocate and build IP header. */ 345 iph = (struct iphdr *) skb_push(skb, sizeof(struct iphdr) + (opt ? opt->optlen : 0)); 346 *((__u16 *)iph) = htons((4 << 12) | (5 << 8) | (inet->tos & 0xff)); 347 iph->tot_len = htons(skb->len); 348 if (ip_dont_fragment(sk, &rt->u.dst) && !ipfragok) 349 iph->frag_off = htons(IP_DF); 350 else 351 iph->frag_off = 0; 352 iph->ttl = ip_select_ttl(inet, &rt->u.dst); 353 iph->protocol = sk->sk_protocol; 354 iph->saddr = rt->rt_src; 355 iph->daddr = rt->rt_dst; 356 skb->nh.iph = iph; 357 /* Transport layer set skb->h.foo itself. */ 358 359 if (opt && opt->optlen) { 360 iph->ihl += opt->optlen >> 2; 361 ip_options_build(skb, opt, inet->daddr, rt, 0); 362 } 363 364 ip_select_ident_more(iph, &rt->u.dst, sk, 365 (skb_shinfo(skb)->tso_segs ?: 1) - 1); 366 367 /* Add an IP checksum. */ 368 ip_send_check(iph); 369 370 skb->priority = sk->sk_priority; 371 372 return NF_HOOK(PF_INET, NF_IP_LOCAL_OUT, skb, NULL, rt->u.dst.dev, 373 dst_output); 374 375 no_route: 376 IP_INC_STATS(IPSTATS_MIB_OUTNOROUTES); 377 kfree_skb(skb); 378 return -EHOSTUNREACH; 379 } 380 381 382 static void ip_copy_metadata(struct sk_buff *to, struct sk_buff *from) 383 { 384 to->pkt_type = from->pkt_type; 385 to->priority = from->priority; 386 to->protocol = from->protocol; 387 dst_release(to->dst); 388 to->dst = dst_clone(from->dst); 389 to->dev = from->dev; 390 391 /* Copy the flags to each fragment. */ 392 IPCB(to)->flags = IPCB(from)->flags; 393 394 #ifdef CONFIG_NET_SCHED 395 to->tc_index = from->tc_index; 396 #endif 397 #ifdef CONFIG_NETFILTER 398 to->nfmark = from->nfmark; 399 /* Connection association is same as pre-frag packet */ 400 nf_conntrack_put(to->nfct); 401 to->nfct = from->nfct; 402 nf_conntrack_get(to->nfct); 403 to->nfctinfo = from->nfctinfo; 404 #if defined(CONFIG_IP_VS) || defined(CONFIG_IP_VS_MODULE) 405 to->ipvs_property = from->ipvs_property; 406 #endif 407 #ifdef CONFIG_BRIDGE_NETFILTER 408 nf_bridge_put(to->nf_bridge); 409 to->nf_bridge = from->nf_bridge; 410 nf_bridge_get(to->nf_bridge); 411 #endif 412 #endif 413 skb_copy_secmark(to, from); 414 } 415 416 /* 417 * This IP datagram is too large to be sent in one piece. Break it up into 418 * smaller pieces (each of size equal to IP header plus 419 * a block of the data of the original IP data part) that will yet fit in a 420 * single device frame, and queue such a frame for sending. 421 */ 422 423 int ip_fragment(struct sk_buff *skb, int (*output)(struct sk_buff*)) 424 { 425 struct iphdr *iph; 426 int raw = 0; 427 int ptr; 428 struct net_device *dev; 429 struct sk_buff *skb2; 430 unsigned int mtu, hlen, left, len, ll_rs; 431 int offset; 432 __be16 not_last_frag; 433 struct rtable *rt = (struct rtable*)skb->dst; 434 int err = 0; 435 436 dev = rt->u.dst.dev; 437 438 /* 439 * Point into the IP datagram header. 440 */ 441 442 iph = skb->nh.iph; 443 444 if (unlikely((iph->frag_off & htons(IP_DF)) && !skb->local_df)) { 445 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, 446 htonl(dst_mtu(&rt->u.dst))); 447 kfree_skb(skb); 448 return -EMSGSIZE; 449 } 450 451 /* 452 * Setup starting values. 453 */ 454 455 hlen = iph->ihl * 4; 456 mtu = dst_mtu(&rt->u.dst) - hlen; /* Size of data space */ 457 IPCB(skb)->flags |= IPSKB_FRAG_COMPLETE; 458 459 /* When frag_list is given, use it. First, check its validity: 460 * some transformers could create wrong frag_list or break existing 461 * one, it is not prohibited. In this case fall back to copying. 462 * 463 * LATER: this step can be merged to real generation of fragments, 464 * we can switch to copy when see the first bad fragment. 465 */ 466 if (skb_shinfo(skb)->frag_list) { 467 struct sk_buff *frag; 468 int first_len = skb_pagelen(skb); 469 470 if (first_len - hlen > mtu || 471 ((first_len - hlen) & 7) || 472 (iph->frag_off & htons(IP_MF|IP_OFFSET)) || 473 skb_cloned(skb)) 474 goto slow_path; 475 476 for (frag = skb_shinfo(skb)->frag_list; frag; frag = frag->next) { 477 /* Correct geometry. */ 478 if (frag->len > mtu || 479 ((frag->len & 7) && frag->next) || 480 skb_headroom(frag) < hlen) 481 goto slow_path; 482 483 /* Partially cloned skb? */ 484 if (skb_shared(frag)) 485 goto slow_path; 486 487 BUG_ON(frag->sk); 488 if (skb->sk) { 489 sock_hold(skb->sk); 490 frag->sk = skb->sk; 491 frag->destructor = sock_wfree; 492 skb->truesize -= frag->truesize; 493 } 494 } 495 496 /* Everything is OK. Generate! */ 497 498 err = 0; 499 offset = 0; 500 frag = skb_shinfo(skb)->frag_list; 501 skb_shinfo(skb)->frag_list = NULL; 502 skb->data_len = first_len - skb_headlen(skb); 503 skb->len = first_len; 504 iph->tot_len = htons(first_len); 505 iph->frag_off = htons(IP_MF); 506 ip_send_check(iph); 507 508 for (;;) { 509 /* Prepare header of the next frame, 510 * before previous one went down. */ 511 if (frag) { 512 frag->ip_summed = CHECKSUM_NONE; 513 frag->h.raw = frag->data; 514 frag->nh.raw = __skb_push(frag, hlen); 515 memcpy(frag->nh.raw, iph, hlen); 516 iph = frag->nh.iph; 517 iph->tot_len = htons(frag->len); 518 ip_copy_metadata(frag, skb); 519 if (offset == 0) 520 ip_options_fragment(frag); 521 offset += skb->len - hlen; 522 iph->frag_off = htons(offset>>3); 523 if (frag->next != NULL) 524 iph->frag_off |= htons(IP_MF); 525 /* Ready, complete checksum */ 526 ip_send_check(iph); 527 } 528 529 err = output(skb); 530 531 if (err || !frag) 532 break; 533 534 skb = frag; 535 frag = skb->next; 536 skb->next = NULL; 537 } 538 539 if (err == 0) { 540 IP_INC_STATS(IPSTATS_MIB_FRAGOKS); 541 return 0; 542 } 543 544 while (frag) { 545 skb = frag->next; 546 kfree_skb(frag); 547 frag = skb; 548 } 549 IP_INC_STATS(IPSTATS_MIB_FRAGFAILS); 550 return err; 551 } 552 553 slow_path: 554 left = skb->len - hlen; /* Space per frame */ 555 ptr = raw + hlen; /* Where to start from */ 556 557 #ifdef CONFIG_BRIDGE_NETFILTER 558 /* for bridged IP traffic encapsulated inside f.e. a vlan header, 559 * we need to make room for the encapsulating header */ 560 ll_rs = LL_RESERVED_SPACE_EXTRA(rt->u.dst.dev, nf_bridge_pad(skb)); 561 mtu -= nf_bridge_pad(skb); 562 #else 563 ll_rs = LL_RESERVED_SPACE(rt->u.dst.dev); 564 #endif 565 /* 566 * Fragment the datagram. 567 */ 568 569 offset = (ntohs(iph->frag_off) & IP_OFFSET) << 3; 570 not_last_frag = iph->frag_off & htons(IP_MF); 571 572 /* 573 * Keep copying data until we run out. 574 */ 575 576 while(left > 0) { 577 len = left; 578 /* IF: it doesn't fit, use 'mtu' - the data space left */ 579 if (len > mtu) 580 len = mtu; 581 /* IF: we are not sending upto and including the packet end 582 then align the next start on an eight byte boundary */ 583 if (len < left) { 584 len &= ~7; 585 } 586 /* 587 * Allocate buffer. 588 */ 589 590 if ((skb2 = alloc_skb(len+hlen+ll_rs, GFP_ATOMIC)) == NULL) { 591 NETDEBUG(KERN_INFO "IP: frag: no memory for new fragment!\n"); 592 err = -ENOMEM; 593 goto fail; 594 } 595 596 /* 597 * Set up data on packet 598 */ 599 600 ip_copy_metadata(skb2, skb); 601 skb_reserve(skb2, ll_rs); 602 skb_put(skb2, len + hlen); 603 skb2->nh.raw = skb2->data; 604 skb2->h.raw = skb2->data + hlen; 605 606 /* 607 * Charge the memory for the fragment to any owner 608 * it might possess 609 */ 610 611 if (skb->sk) 612 skb_set_owner_w(skb2, skb->sk); 613 614 /* 615 * Copy the packet header into the new buffer. 616 */ 617 618 memcpy(skb2->nh.raw, skb->data, hlen); 619 620 /* 621 * Copy a block of the IP datagram. 622 */ 623 if (skb_copy_bits(skb, ptr, skb2->h.raw, len)) 624 BUG(); 625 left -= len; 626 627 /* 628 * Fill in the new header fields. 629 */ 630 iph = skb2->nh.iph; 631 iph->frag_off = htons((offset >> 3)); 632 633 /* ANK: dirty, but effective trick. Upgrade options only if 634 * the segment to be fragmented was THE FIRST (otherwise, 635 * options are already fixed) and make it ONCE 636 * on the initial skb, so that all the following fragments 637 * will inherit fixed options. 638 */ 639 if (offset == 0) 640 ip_options_fragment(skb); 641 642 /* 643 * Added AC : If we are fragmenting a fragment that's not the 644 * last fragment then keep MF on each bit 645 */ 646 if (left > 0 || not_last_frag) 647 iph->frag_off |= htons(IP_MF); 648 ptr += len; 649 offset += len; 650 651 /* 652 * Put this fragment into the sending queue. 653 */ 654 655 IP_INC_STATS(IPSTATS_MIB_FRAGCREATES); 656 657 iph->tot_len = htons(len + hlen); 658 659 ip_send_check(iph); 660 661 err = output(skb2); 662 if (err) 663 goto fail; 664 } 665 kfree_skb(skb); 666 IP_INC_STATS(IPSTATS_MIB_FRAGOKS); 667 return err; 668 669 fail: 670 kfree_skb(skb); 671 IP_INC_STATS(IPSTATS_MIB_FRAGFAILS); 672 return err; 673 } 674 675 EXPORT_SYMBOL(ip_fragment); 676 677 int 678 ip_generic_getfrag(void *from, char *to, int offset, int len, int odd, struct sk_buff *skb) 679 { 680 struct iovec *iov = from; 681 682 if (skb->ip_summed == CHECKSUM_HW) { 683 if (memcpy_fromiovecend(to, iov, offset, len) < 0) 684 return -EFAULT; 685 } else { 686 unsigned int csum = 0; 687 if (csum_partial_copy_fromiovecend(to, iov, offset, len, &csum) < 0) 688 return -EFAULT; 689 skb->csum = csum_block_add(skb->csum, csum, odd); 690 } 691 return 0; 692 } 693 694 static inline unsigned int 695 csum_page(struct page *page, int offset, int copy) 696 { 697 char *kaddr; 698 unsigned int csum; 699 kaddr = kmap(page); 700 csum = csum_partial(kaddr + offset, copy, 0); 701 kunmap(page); 702 return csum; 703 } 704 705 static inline int ip_ufo_append_data(struct sock *sk, 706 int getfrag(void *from, char *to, int offset, int len, 707 int odd, struct sk_buff *skb), 708 void *from, int length, int hh_len, int fragheaderlen, 709 int transhdrlen, int mtu,unsigned int flags) 710 { 711 struct sk_buff *skb; 712 int err; 713 714 /* There is support for UDP fragmentation offload by network 715 * device, so create one single skb packet containing complete 716 * udp datagram 717 */ 718 if ((skb = skb_peek_tail(&sk->sk_write_queue)) == NULL) { 719 skb = sock_alloc_send_skb(sk, 720 hh_len + fragheaderlen + transhdrlen + 20, 721 (flags & MSG_DONTWAIT), &err); 722 723 if (skb == NULL) 724 return err; 725 726 /* reserve space for Hardware header */ 727 skb_reserve(skb, hh_len); 728 729 /* create space for UDP/IP header */ 730 skb_put(skb,fragheaderlen + transhdrlen); 731 732 /* initialize network header pointer */ 733 skb->nh.raw = skb->data; 734 735 /* initialize protocol header pointer */ 736 skb->h.raw = skb->data + fragheaderlen; 737 738 skb->ip_summed = CHECKSUM_HW; 739 skb->csum = 0; 740 sk->sk_sndmsg_off = 0; 741 } 742 743 err = skb_append_datato_frags(sk,skb, getfrag, from, 744 (length - transhdrlen)); 745 if (!err) { 746 /* specify the length of each IP datagram fragment*/ 747 skb_shinfo(skb)->ufo_size = (mtu - fragheaderlen); 748 __skb_queue_tail(&sk->sk_write_queue, skb); 749 750 return 0; 751 } 752 /* There is not enough support do UFO , 753 * so follow normal path 754 */ 755 kfree_skb(skb); 756 return err; 757 } 758 759 /* 760 * ip_append_data() and ip_append_page() can make one large IP datagram 761 * from many pieces of data. Each pieces will be holded on the socket 762 * until ip_push_pending_frames() is called. Each piece can be a page 763 * or non-page data. 764 * 765 * Not only UDP, other transport protocols - e.g. raw sockets - can use 766 * this interface potentially. 767 * 768 * LATER: length must be adjusted by pad at tail, when it is required. 769 */ 770 int ip_append_data(struct sock *sk, 771 int getfrag(void *from, char *to, int offset, int len, 772 int odd, struct sk_buff *skb), 773 void *from, int length, int transhdrlen, 774 struct ipcm_cookie *ipc, struct rtable *rt, 775 unsigned int flags) 776 { 777 struct inet_sock *inet = inet_sk(sk); 778 struct sk_buff *skb; 779 780 struct ip_options *opt = NULL; 781 int hh_len; 782 int exthdrlen; 783 int mtu; 784 int copy; 785 int err; 786 int offset = 0; 787 unsigned int maxfraglen, fragheaderlen; 788 int csummode = CHECKSUM_NONE; 789 790 if (flags&MSG_PROBE) 791 return 0; 792 793 if (skb_queue_empty(&sk->sk_write_queue)) { 794 /* 795 * setup for corking. 796 */ 797 opt = ipc->opt; 798 if (opt) { 799 if (inet->cork.opt == NULL) { 800 inet->cork.opt = kmalloc(sizeof(struct ip_options) + 40, sk->sk_allocation); 801 if (unlikely(inet->cork.opt == NULL)) 802 return -ENOBUFS; 803 } 804 memcpy(inet->cork.opt, opt, sizeof(struct ip_options)+opt->optlen); 805 inet->cork.flags |= IPCORK_OPT; 806 inet->cork.addr = ipc->addr; 807 } 808 dst_hold(&rt->u.dst); 809 inet->cork.fragsize = mtu = dst_mtu(rt->u.dst.path); 810 inet->cork.rt = rt; 811 inet->cork.length = 0; 812 sk->sk_sndmsg_page = NULL; 813 sk->sk_sndmsg_off = 0; 814 if ((exthdrlen = rt->u.dst.header_len) != 0) { 815 length += exthdrlen; 816 transhdrlen += exthdrlen; 817 } 818 } else { 819 rt = inet->cork.rt; 820 if (inet->cork.flags & IPCORK_OPT) 821 opt = inet->cork.opt; 822 823 transhdrlen = 0; 824 exthdrlen = 0; 825 mtu = inet->cork.fragsize; 826 } 827 hh_len = LL_RESERVED_SPACE(rt->u.dst.dev); 828 829 fragheaderlen = sizeof(struct iphdr) + (opt ? opt->optlen : 0); 830 maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen; 831 832 if (inet->cork.length + length > 0xFFFF - fragheaderlen) { 833 ip_local_error(sk, EMSGSIZE, rt->rt_dst, inet->dport, mtu-exthdrlen); 834 return -EMSGSIZE; 835 } 836 837 /* 838 * transhdrlen > 0 means that this is the first fragment and we wish 839 * it won't be fragmented in the future. 840 */ 841 if (transhdrlen && 842 length + fragheaderlen <= mtu && 843 rt->u.dst.dev->features & NETIF_F_ALL_CSUM && 844 !exthdrlen) 845 csummode = CHECKSUM_HW; 846 847 inet->cork.length += length; 848 if (((length > mtu) && (sk->sk_protocol == IPPROTO_UDP)) && 849 (rt->u.dst.dev->features & NETIF_F_UFO)) { 850 851 err = ip_ufo_append_data(sk, getfrag, from, length, hh_len, 852 fragheaderlen, transhdrlen, mtu, 853 flags); 854 if (err) 855 goto error; 856 return 0; 857 } 858 859 /* So, what's going on in the loop below? 860 * 861 * We use calculated fragment length to generate chained skb, 862 * each of segments is IP fragment ready for sending to network after 863 * adding appropriate IP header. 864 */ 865 866 if ((skb = skb_peek_tail(&sk->sk_write_queue)) == NULL) 867 goto alloc_new_skb; 868 869 while (length > 0) { 870 /* Check if the remaining data fits into current packet. */ 871 copy = mtu - skb->len; 872 if (copy < length) 873 copy = maxfraglen - skb->len; 874 if (copy <= 0) { 875 char *data; 876 unsigned int datalen; 877 unsigned int fraglen; 878 unsigned int fraggap; 879 unsigned int alloclen; 880 struct sk_buff *skb_prev; 881 alloc_new_skb: 882 skb_prev = skb; 883 if (skb_prev) 884 fraggap = skb_prev->len - maxfraglen; 885 else 886 fraggap = 0; 887 888 /* 889 * If remaining data exceeds the mtu, 890 * we know we need more fragment(s). 891 */ 892 datalen = length + fraggap; 893 if (datalen > mtu - fragheaderlen) 894 datalen = maxfraglen - fragheaderlen; 895 fraglen = datalen + fragheaderlen; 896 897 if ((flags & MSG_MORE) && 898 !(rt->u.dst.dev->features&NETIF_F_SG)) 899 alloclen = mtu; 900 else 901 alloclen = datalen + fragheaderlen; 902 903 /* The last fragment gets additional space at tail. 904 * Note, with MSG_MORE we overallocate on fragments, 905 * because we have no idea what fragment will be 906 * the last. 907 */ 908 if (datalen == length + fraggap) 909 alloclen += rt->u.dst.trailer_len; 910 911 if (transhdrlen) { 912 skb = sock_alloc_send_skb(sk, 913 alloclen + hh_len + 15, 914 (flags & MSG_DONTWAIT), &err); 915 } else { 916 skb = NULL; 917 if (atomic_read(&sk->sk_wmem_alloc) <= 918 2 * sk->sk_sndbuf) 919 skb = sock_wmalloc(sk, 920 alloclen + hh_len + 15, 1, 921 sk->sk_allocation); 922 if (unlikely(skb == NULL)) 923 err = -ENOBUFS; 924 } 925 if (skb == NULL) 926 goto error; 927 928 /* 929 * Fill in the control structures 930 */ 931 skb->ip_summed = csummode; 932 skb->csum = 0; 933 skb_reserve(skb, hh_len); 934 935 /* 936 * Find where to start putting bytes. 937 */ 938 data = skb_put(skb, fraglen); 939 skb->nh.raw = data + exthdrlen; 940 data += fragheaderlen; 941 skb->h.raw = data + exthdrlen; 942 943 if (fraggap) { 944 skb->csum = skb_copy_and_csum_bits( 945 skb_prev, maxfraglen, 946 data + transhdrlen, fraggap, 0); 947 skb_prev->csum = csum_sub(skb_prev->csum, 948 skb->csum); 949 data += fraggap; 950 skb_trim(skb_prev, maxfraglen); 951 } 952 953 copy = datalen - transhdrlen - fraggap; 954 if (copy > 0 && getfrag(from, data + transhdrlen, offset, copy, fraggap, skb) < 0) { 955 err = -EFAULT; 956 kfree_skb(skb); 957 goto error; 958 } 959 960 offset += copy; 961 length -= datalen - fraggap; 962 transhdrlen = 0; 963 exthdrlen = 0; 964 csummode = CHECKSUM_NONE; 965 966 /* 967 * Put the packet on the pending queue. 968 */ 969 __skb_queue_tail(&sk->sk_write_queue, skb); 970 continue; 971 } 972 973 if (copy > length) 974 copy = length; 975 976 if (!(rt->u.dst.dev->features&NETIF_F_SG)) { 977 unsigned int off; 978 979 off = skb->len; 980 if (getfrag(from, skb_put(skb, copy), 981 offset, copy, off, skb) < 0) { 982 __skb_trim(skb, off); 983 err = -EFAULT; 984 goto error; 985 } 986 } else { 987 int i = skb_shinfo(skb)->nr_frags; 988 skb_frag_t *frag = &skb_shinfo(skb)->frags[i-1]; 989 struct page *page = sk->sk_sndmsg_page; 990 int off = sk->sk_sndmsg_off; 991 unsigned int left; 992 993 if (page && (left = PAGE_SIZE - off) > 0) { 994 if (copy >= left) 995 copy = left; 996 if (page != frag->page) { 997 if (i == MAX_SKB_FRAGS) { 998 err = -EMSGSIZE; 999 goto error; 1000 } 1001 get_page(page); 1002 skb_fill_page_desc(skb, i, page, sk->sk_sndmsg_off, 0); 1003 frag = &skb_shinfo(skb)->frags[i]; 1004 } 1005 } else if (i < MAX_SKB_FRAGS) { 1006 if (copy > PAGE_SIZE) 1007 copy = PAGE_SIZE; 1008 page = alloc_pages(sk->sk_allocation, 0); 1009 if (page == NULL) { 1010 err = -ENOMEM; 1011 goto error; 1012 } 1013 sk->sk_sndmsg_page = page; 1014 sk->sk_sndmsg_off = 0; 1015 1016 skb_fill_page_desc(skb, i, page, 0, 0); 1017 frag = &skb_shinfo(skb)->frags[i]; 1018 skb->truesize += PAGE_SIZE; 1019 atomic_add(PAGE_SIZE, &sk->sk_wmem_alloc); 1020 } else { 1021 err = -EMSGSIZE; 1022 goto error; 1023 } 1024 if (getfrag(from, page_address(frag->page)+frag->page_offset+frag->size, offset, copy, skb->len, skb) < 0) { 1025 err = -EFAULT; 1026 goto error; 1027 } 1028 sk->sk_sndmsg_off += copy; 1029 frag->size += copy; 1030 skb->len += copy; 1031 skb->data_len += copy; 1032 } 1033 offset += copy; 1034 length -= copy; 1035 } 1036 1037 return 0; 1038 1039 error: 1040 inet->cork.length -= length; 1041 IP_INC_STATS(IPSTATS_MIB_OUTDISCARDS); 1042 return err; 1043 } 1044 1045 ssize_t ip_append_page(struct sock *sk, struct page *page, 1046 int offset, size_t size, int flags) 1047 { 1048 struct inet_sock *inet = inet_sk(sk); 1049 struct sk_buff *skb; 1050 struct rtable *rt; 1051 struct ip_options *opt = NULL; 1052 int hh_len; 1053 int mtu; 1054 int len; 1055 int err; 1056 unsigned int maxfraglen, fragheaderlen, fraggap; 1057 1058 if (inet->hdrincl) 1059 return -EPERM; 1060 1061 if (flags&MSG_PROBE) 1062 return 0; 1063 1064 if (skb_queue_empty(&sk->sk_write_queue)) 1065 return -EINVAL; 1066 1067 rt = inet->cork.rt; 1068 if (inet->cork.flags & IPCORK_OPT) 1069 opt = inet->cork.opt; 1070 1071 if (!(rt->u.dst.dev->features&NETIF_F_SG)) 1072 return -EOPNOTSUPP; 1073 1074 hh_len = LL_RESERVED_SPACE(rt->u.dst.dev); 1075 mtu = inet->cork.fragsize; 1076 1077 fragheaderlen = sizeof(struct iphdr) + (opt ? opt->optlen : 0); 1078 maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen; 1079 1080 if (inet->cork.length + size > 0xFFFF - fragheaderlen) { 1081 ip_local_error(sk, EMSGSIZE, rt->rt_dst, inet->dport, mtu); 1082 return -EMSGSIZE; 1083 } 1084 1085 if ((skb = skb_peek_tail(&sk->sk_write_queue)) == NULL) 1086 return -EINVAL; 1087 1088 inet->cork.length += size; 1089 if ((sk->sk_protocol == IPPROTO_UDP) && 1090 (rt->u.dst.dev->features & NETIF_F_UFO)) 1091 skb_shinfo(skb)->ufo_size = (mtu - fragheaderlen); 1092 1093 1094 while (size > 0) { 1095 int i; 1096 1097 if (skb_shinfo(skb)->ufo_size) 1098 len = size; 1099 else { 1100 1101 /* Check if the remaining data fits into current packet. */ 1102 len = mtu - skb->len; 1103 if (len < size) 1104 len = maxfraglen - skb->len; 1105 } 1106 if (len <= 0) { 1107 struct sk_buff *skb_prev; 1108 char *data; 1109 struct iphdr *iph; 1110 int alloclen; 1111 1112 skb_prev = skb; 1113 fraggap = skb_prev->len - maxfraglen; 1114 1115 alloclen = fragheaderlen + hh_len + fraggap + 15; 1116 skb = sock_wmalloc(sk, alloclen, 1, sk->sk_allocation); 1117 if (unlikely(!skb)) { 1118 err = -ENOBUFS; 1119 goto error; 1120 } 1121 1122 /* 1123 * Fill in the control structures 1124 */ 1125 skb->ip_summed = CHECKSUM_NONE; 1126 skb->csum = 0; 1127 skb_reserve(skb, hh_len); 1128 1129 /* 1130 * Find where to start putting bytes. 1131 */ 1132 data = skb_put(skb, fragheaderlen + fraggap); 1133 skb->nh.iph = iph = (struct iphdr *)data; 1134 data += fragheaderlen; 1135 skb->h.raw = data; 1136 1137 if (fraggap) { 1138 skb->csum = skb_copy_and_csum_bits( 1139 skb_prev, maxfraglen, 1140 data, fraggap, 0); 1141 skb_prev->csum = csum_sub(skb_prev->csum, 1142 skb->csum); 1143 skb_trim(skb_prev, maxfraglen); 1144 } 1145 1146 /* 1147 * Put the packet on the pending queue. 1148 */ 1149 __skb_queue_tail(&sk->sk_write_queue, skb); 1150 continue; 1151 } 1152 1153 i = skb_shinfo(skb)->nr_frags; 1154 if (len > size) 1155 len = size; 1156 if (skb_can_coalesce(skb, i, page, offset)) { 1157 skb_shinfo(skb)->frags[i-1].size += len; 1158 } else if (i < MAX_SKB_FRAGS) { 1159 get_page(page); 1160 skb_fill_page_desc(skb, i, page, offset, len); 1161 } else { 1162 err = -EMSGSIZE; 1163 goto error; 1164 } 1165 1166 if (skb->ip_summed == CHECKSUM_NONE) { 1167 unsigned int csum; 1168 csum = csum_page(page, offset, len); 1169 skb->csum = csum_block_add(skb->csum, csum, skb->len); 1170 } 1171 1172 skb->len += len; 1173 skb->data_len += len; 1174 offset += len; 1175 size -= len; 1176 } 1177 return 0; 1178 1179 error: 1180 inet->cork.length -= size; 1181 IP_INC_STATS(IPSTATS_MIB_OUTDISCARDS); 1182 return err; 1183 } 1184 1185 /* 1186 * Combined all pending IP fragments on the socket as one IP datagram 1187 * and push them out. 1188 */ 1189 int ip_push_pending_frames(struct sock *sk) 1190 { 1191 struct sk_buff *skb, *tmp_skb; 1192 struct sk_buff **tail_skb; 1193 struct inet_sock *inet = inet_sk(sk); 1194 struct ip_options *opt = NULL; 1195 struct rtable *rt = inet->cork.rt; 1196 struct iphdr *iph; 1197 __be16 df = 0; 1198 __u8 ttl; 1199 int err = 0; 1200 1201 if ((skb = __skb_dequeue(&sk->sk_write_queue)) == NULL) 1202 goto out; 1203 tail_skb = &(skb_shinfo(skb)->frag_list); 1204 1205 /* move skb->data to ip header from ext header */ 1206 if (skb->data < skb->nh.raw) 1207 __skb_pull(skb, skb->nh.raw - skb->data); 1208 while ((tmp_skb = __skb_dequeue(&sk->sk_write_queue)) != NULL) { 1209 __skb_pull(tmp_skb, skb->h.raw - skb->nh.raw); 1210 *tail_skb = tmp_skb; 1211 tail_skb = &(tmp_skb->next); 1212 skb->len += tmp_skb->len; 1213 skb->data_len += tmp_skb->len; 1214 skb->truesize += tmp_skb->truesize; 1215 __sock_put(tmp_skb->sk); 1216 tmp_skb->destructor = NULL; 1217 tmp_skb->sk = NULL; 1218 } 1219 1220 /* Unless user demanded real pmtu discovery (IP_PMTUDISC_DO), we allow 1221 * to fragment the frame generated here. No matter, what transforms 1222 * how transforms change size of the packet, it will come out. 1223 */ 1224 if (inet->pmtudisc != IP_PMTUDISC_DO) 1225 skb->local_df = 1; 1226 1227 /* DF bit is set when we want to see DF on outgoing frames. 1228 * If local_df is set too, we still allow to fragment this frame 1229 * locally. */ 1230 if (inet->pmtudisc == IP_PMTUDISC_DO || 1231 (skb->len <= dst_mtu(&rt->u.dst) && 1232 ip_dont_fragment(sk, &rt->u.dst))) 1233 df = htons(IP_DF); 1234 1235 if (inet->cork.flags & IPCORK_OPT) 1236 opt = inet->cork.opt; 1237 1238 if (rt->rt_type == RTN_MULTICAST) 1239 ttl = inet->mc_ttl; 1240 else 1241 ttl = ip_select_ttl(inet, &rt->u.dst); 1242 1243 iph = (struct iphdr *)skb->data; 1244 iph->version = 4; 1245 iph->ihl = 5; 1246 if (opt) { 1247 iph->ihl += opt->optlen>>2; 1248 ip_options_build(skb, opt, inet->cork.addr, rt, 0); 1249 } 1250 iph->tos = inet->tos; 1251 iph->tot_len = htons(skb->len); 1252 iph->frag_off = df; 1253 ip_select_ident(iph, &rt->u.dst, sk); 1254 iph->ttl = ttl; 1255 iph->protocol = sk->sk_protocol; 1256 iph->saddr = rt->rt_src; 1257 iph->daddr = rt->rt_dst; 1258 ip_send_check(iph); 1259 1260 skb->priority = sk->sk_priority; 1261 skb->dst = dst_clone(&rt->u.dst); 1262 1263 /* Netfilter gets whole the not fragmented skb. */ 1264 err = NF_HOOK(PF_INET, NF_IP_LOCAL_OUT, skb, NULL, 1265 skb->dst->dev, dst_output); 1266 if (err) { 1267 if (err > 0) 1268 err = inet->recverr ? net_xmit_errno(err) : 0; 1269 if (err) 1270 goto error; 1271 } 1272 1273 out: 1274 inet->cork.flags &= ~IPCORK_OPT; 1275 kfree(inet->cork.opt); 1276 inet->cork.opt = NULL; 1277 if (inet->cork.rt) { 1278 ip_rt_put(inet->cork.rt); 1279 inet->cork.rt = NULL; 1280 } 1281 return err; 1282 1283 error: 1284 IP_INC_STATS(IPSTATS_MIB_OUTDISCARDS); 1285 goto out; 1286 } 1287 1288 /* 1289 * Throw away all pending data on the socket. 1290 */ 1291 void ip_flush_pending_frames(struct sock *sk) 1292 { 1293 struct inet_sock *inet = inet_sk(sk); 1294 struct sk_buff *skb; 1295 1296 while ((skb = __skb_dequeue_tail(&sk->sk_write_queue)) != NULL) 1297 kfree_skb(skb); 1298 1299 inet->cork.flags &= ~IPCORK_OPT; 1300 kfree(inet->cork.opt); 1301 inet->cork.opt = NULL; 1302 if (inet->cork.rt) { 1303 ip_rt_put(inet->cork.rt); 1304 inet->cork.rt = NULL; 1305 } 1306 } 1307 1308 1309 /* 1310 * Fetch data from kernel space and fill in checksum if needed. 1311 */ 1312 static int ip_reply_glue_bits(void *dptr, char *to, int offset, 1313 int len, int odd, struct sk_buff *skb) 1314 { 1315 unsigned int csum; 1316 1317 csum = csum_partial_copy_nocheck(dptr+offset, to, len, 0); 1318 skb->csum = csum_block_add(skb->csum, csum, odd); 1319 return 0; 1320 } 1321 1322 /* 1323 * Generic function to send a packet as reply to another packet. 1324 * Used to send TCP resets so far. ICMP should use this function too. 1325 * 1326 * Should run single threaded per socket because it uses the sock 1327 * structure to pass arguments. 1328 * 1329 * LATER: switch from ip_build_xmit to ip_append_* 1330 */ 1331 void ip_send_reply(struct sock *sk, struct sk_buff *skb, struct ip_reply_arg *arg, 1332 unsigned int len) 1333 { 1334 struct inet_sock *inet = inet_sk(sk); 1335 struct { 1336 struct ip_options opt; 1337 char data[40]; 1338 } replyopts; 1339 struct ipcm_cookie ipc; 1340 u32 daddr; 1341 struct rtable *rt = (struct rtable*)skb->dst; 1342 1343 if (ip_options_echo(&replyopts.opt, skb)) 1344 return; 1345 1346 daddr = ipc.addr = rt->rt_src; 1347 ipc.opt = NULL; 1348 1349 if (replyopts.opt.optlen) { 1350 ipc.opt = &replyopts.opt; 1351 1352 if (ipc.opt->srr) 1353 daddr = replyopts.opt.faddr; 1354 } 1355 1356 { 1357 struct flowi fl = { .nl_u = { .ip4_u = 1358 { .daddr = daddr, 1359 .saddr = rt->rt_spec_dst, 1360 .tos = RT_TOS(skb->nh.iph->tos) } }, 1361 /* Not quite clean, but right. */ 1362 .uli_u = { .ports = 1363 { .sport = skb->h.th->dest, 1364 .dport = skb->h.th->source } }, 1365 .proto = sk->sk_protocol }; 1366 if (ip_route_output_key(&rt, &fl)) 1367 return; 1368 } 1369 1370 /* And let IP do all the hard work. 1371 1372 This chunk is not reenterable, hence spinlock. 1373 Note that it uses the fact, that this function is called 1374 with locally disabled BH and that sk cannot be already spinlocked. 1375 */ 1376 bh_lock_sock(sk); 1377 inet->tos = skb->nh.iph->tos; 1378 sk->sk_priority = skb->priority; 1379 sk->sk_protocol = skb->nh.iph->protocol; 1380 ip_append_data(sk, ip_reply_glue_bits, arg->iov->iov_base, len, 0, 1381 &ipc, rt, MSG_DONTWAIT); 1382 if ((skb = skb_peek(&sk->sk_write_queue)) != NULL) { 1383 if (arg->csumoffset >= 0) 1384 *((u16 *)skb->h.raw + arg->csumoffset) = csum_fold(csum_add(skb->csum, arg->csum)); 1385 skb->ip_summed = CHECKSUM_NONE; 1386 ip_push_pending_frames(sk); 1387 } 1388 1389 bh_unlock_sock(sk); 1390 1391 ip_rt_put(rt); 1392 } 1393 1394 void __init ip_init(void) 1395 { 1396 ip_rt_init(); 1397 inet_initpeers(); 1398 1399 #if defined(CONFIG_IP_MULTICAST) && defined(CONFIG_PROC_FS) 1400 igmp_mc_proc_init(); 1401 #endif 1402 } 1403 1404 EXPORT_SYMBOL(ip_generic_getfrag); 1405 EXPORT_SYMBOL(ip_queue_xmit); 1406 EXPORT_SYMBOL(ip_send_check); 1407