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