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 57 #include <linux/socket.h> 58 #include <linux/sockios.h> 59 #include <linux/in.h> 60 #include <linux/inet.h> 61 #include <linux/netdevice.h> 62 #include <linux/etherdevice.h> 63 #include <linux/proc_fs.h> 64 #include <linux/stat.h> 65 #include <linux/init.h> 66 67 #include <net/snmp.h> 68 #include <net/ip.h> 69 #include <net/protocol.h> 70 #include <net/route.h> 71 #include <net/xfrm.h> 72 #include <linux/skbuff.h> 73 #include <net/sock.h> 74 #include <net/arp.h> 75 #include <net/icmp.h> 76 #include <net/checksum.h> 77 #include <net/inetpeer.h> 78 #include <net/checksum.h> 79 #include <linux/igmp.h> 80 #include <linux/netfilter_ipv4.h> 81 #include <linux/netfilter_bridge.h> 82 #include <linux/mroute.h> 83 #include <linux/netlink.h> 84 #include <linux/tcp.h> 85 86 int sysctl_ip_default_ttl = IPDEFTTL; 87 88 /* Generate a checksum for an outgoing IP datagram. */ 89 __inline__ void ip_send_check(struct iphdr *iph) 90 { 91 iph->check = 0; 92 iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl); 93 } 94 95 /* dev_loopback_xmit for use with netfilter. */ 96 static int ip_dev_loopback_xmit(struct sk_buff *newskb) 97 { 98 newskb->mac.raw = newskb->data; 99 __skb_pull(newskb, newskb->nh.raw - newskb->data); 100 newskb->pkt_type = PACKET_LOOPBACK; 101 newskb->ip_summed = CHECKSUM_UNNECESSARY; 102 BUG_TRAP(newskb->dst); 103 netif_rx(newskb); 104 return 0; 105 } 106 107 static inline int ip_select_ttl(struct inet_sock *inet, struct dst_entry *dst) 108 { 109 int ttl = inet->uc_ttl; 110 111 if (ttl < 0) 112 ttl = dst_metric(dst, RTAX_HOPLIMIT); 113 return ttl; 114 } 115 116 /* 117 * Add an ip header to a skbuff and send it out. 118 * 119 */ 120 int ip_build_and_send_pkt(struct sk_buff *skb, struct sock *sk, 121 u32 saddr, u32 daddr, struct ip_options *opt) 122 { 123 struct inet_sock *inet = inet_sk(sk); 124 struct rtable *rt = (struct rtable *)skb->dst; 125 struct iphdr *iph; 126 127 /* Build the IP header. */ 128 if (opt) 129 iph=(struct iphdr *)skb_push(skb,sizeof(struct iphdr) + opt->optlen); 130 else 131 iph=(struct iphdr *)skb_push(skb,sizeof(struct iphdr)); 132 133 iph->version = 4; 134 iph->ihl = 5; 135 iph->tos = inet->tos; 136 if (ip_dont_fragment(sk, &rt->u.dst)) 137 iph->frag_off = htons(IP_DF); 138 else 139 iph->frag_off = 0; 140 iph->ttl = ip_select_ttl(inet, &rt->u.dst); 141 iph->daddr = rt->rt_dst; 142 iph->saddr = rt->rt_src; 143 iph->protocol = sk->sk_protocol; 144 iph->tot_len = htons(skb->len); 145 ip_select_ident(iph, &rt->u.dst, sk); 146 skb->nh.iph = iph; 147 148 if (opt && opt->optlen) { 149 iph->ihl += opt->optlen>>2; 150 ip_options_build(skb, opt, daddr, rt, 0); 151 } 152 ip_send_check(iph); 153 154 skb->priority = sk->sk_priority; 155 156 /* Send it out. */ 157 return NF_HOOK(PF_INET, NF_IP_LOCAL_OUT, skb, NULL, rt->u.dst.dev, 158 dst_output); 159 } 160 161 EXPORT_SYMBOL_GPL(ip_build_and_send_pkt); 162 163 static inline int ip_finish_output2(struct sk_buff *skb) 164 { 165 struct dst_entry *dst = skb->dst; 166 struct hh_cache *hh = dst->hh; 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 (hh) { 186 int hh_alen; 187 188 read_lock_bh(&hh->hh_lock); 189 hh_alen = HH_DATA_ALIGN(hh->hh_len); 190 memcpy(skb->data - hh_alen, hh->hh_data, hh_alen); 191 read_unlock_bh(&hh->hh_lock); 192 skb_push(skb, hh->hh_len); 193 return hh->hh_output(skb); 194 } else if (dst->neighbour) 195 return dst->neighbour->output(skb); 196 197 if (net_ratelimit()) 198 printk(KERN_DEBUG "ip_finish_output2: No header cache and no neighbour!\n"); 199 kfree_skb(skb); 200 return -EINVAL; 201 } 202 203 static inline int ip_finish_output(struct sk_buff *skb) 204 { 205 #if defined(CONFIG_NETFILTER) && defined(CONFIG_XFRM) 206 /* Policy lookup after SNAT yielded a new policy */ 207 if (skb->dst->xfrm != NULL) { 208 IPCB(skb)->flags |= IPSKB_REROUTED; 209 return dst_output(skb); 210 } 211 #endif 212 if (skb->len > dst_mtu(skb->dst) && !skb_is_gso(skb)) 213 return ip_fragment(skb, ip_finish_output2); 214 else 215 return ip_finish_output2(skb); 216 } 217 218 int ip_mc_output(struct sk_buff *skb) 219 { 220 struct sock *sk = skb->sk; 221 struct rtable *rt = (struct rtable*)skb->dst; 222 struct net_device *dev = rt->u.dst.dev; 223 224 /* 225 * If the indicated interface is up and running, send the packet. 226 */ 227 IP_INC_STATS(IPSTATS_MIB_OUTREQUESTS); 228 229 skb->dev = dev; 230 skb->protocol = htons(ETH_P_IP); 231 232 /* 233 * Multicasts are looped back for other local users 234 */ 235 236 if (rt->rt_flags&RTCF_MULTICAST) { 237 if ((!sk || inet_sk(sk)->mc_loop) 238 #ifdef CONFIG_IP_MROUTE 239 /* Small optimization: do not loopback not local frames, 240 which returned after forwarding; they will be dropped 241 by ip_mr_input in any case. 242 Note, that local frames are looped back to be delivered 243 to local recipients. 244 245 This check is duplicated in ip_mr_input at the moment. 246 */ 247 && ((rt->rt_flags&RTCF_LOCAL) || !(IPCB(skb)->flags&IPSKB_FORWARDED)) 248 #endif 249 ) { 250 struct sk_buff *newskb = skb_clone(skb, GFP_ATOMIC); 251 if (newskb) 252 NF_HOOK(PF_INET, NF_IP_POST_ROUTING, newskb, NULL, 253 newskb->dev, 254 ip_dev_loopback_xmit); 255 } 256 257 /* Multicasts with ttl 0 must not go beyond the host */ 258 259 if (skb->nh.iph->ttl == 0) { 260 kfree_skb(skb); 261 return 0; 262 } 263 } 264 265 if (rt->rt_flags&RTCF_BROADCAST) { 266 struct sk_buff *newskb = skb_clone(skb, GFP_ATOMIC); 267 if (newskb) 268 NF_HOOK(PF_INET, NF_IP_POST_ROUTING, newskb, NULL, 269 newskb->dev, ip_dev_loopback_xmit); 270 } 271 272 return NF_HOOK_COND(PF_INET, NF_IP_POST_ROUTING, skb, NULL, skb->dev, 273 ip_finish_output, 274 !(IPCB(skb)->flags & IPSKB_REROUTED)); 275 } 276 277 int ip_output(struct sk_buff *skb) 278 { 279 struct net_device *dev = skb->dst->dev; 280 281 IP_INC_STATS(IPSTATS_MIB_OUTREQUESTS); 282 283 skb->dev = dev; 284 skb->protocol = htons(ETH_P_IP); 285 286 return NF_HOOK_COND(PF_INET, NF_IP_POST_ROUTING, skb, NULL, dev, 287 ip_finish_output, 288 !(IPCB(skb)->flags & IPSKB_REROUTED)); 289 } 290 291 int ip_queue_xmit(struct sk_buff *skb, int ipfragok) 292 { 293 struct sock *sk = skb->sk; 294 struct inet_sock *inet = inet_sk(sk); 295 struct ip_options *opt = inet->opt; 296 struct rtable *rt; 297 struct iphdr *iph; 298 299 /* Skip all of this if the packet is already routed, 300 * f.e. by something like SCTP. 301 */ 302 rt = (struct rtable *) skb->dst; 303 if (rt != NULL) 304 goto packet_routed; 305 306 /* Make sure we can route this packet. */ 307 rt = (struct rtable *)__sk_dst_check(sk, 0); 308 if (rt == NULL) { 309 u32 daddr; 310 311 /* Use correct destination address if we have options. */ 312 daddr = inet->daddr; 313 if(opt && opt->srr) 314 daddr = opt->faddr; 315 316 { 317 struct flowi fl = { .oif = sk->sk_bound_dev_if, 318 .nl_u = { .ip4_u = 319 { .daddr = daddr, 320 .saddr = inet->saddr, 321 .tos = RT_CONN_FLAGS(sk) } }, 322 .proto = sk->sk_protocol, 323 .uli_u = { .ports = 324 { .sport = inet->sport, 325 .dport = inet->dport } } }; 326 327 /* If this fails, retransmit mechanism of transport layer will 328 * keep trying until route appears or the connection times 329 * itself out. 330 */ 331 if (ip_route_output_flow(&rt, &fl, sk, 0)) 332 goto no_route; 333 } 334 sk_setup_caps(sk, &rt->u.dst); 335 } 336 skb->dst = dst_clone(&rt->u.dst); 337 338 packet_routed: 339 if (opt && opt->is_strictroute && rt->rt_dst != rt->rt_gateway) 340 goto no_route; 341 342 /* OK, we know where to send it, allocate and build IP header. */ 343 iph = (struct iphdr *) skb_push(skb, sizeof(struct iphdr) + (opt ? opt->optlen : 0)); 344 *((__u16 *)iph) = htons((4 << 12) | (5 << 8) | (inet->tos & 0xff)); 345 iph->tot_len = htons(skb->len); 346 if (ip_dont_fragment(sk, &rt->u.dst) && !ipfragok) 347 iph->frag_off = htons(IP_DF); 348 else 349 iph->frag_off = 0; 350 iph->ttl = ip_select_ttl(inet, &rt->u.dst); 351 iph->protocol = sk->sk_protocol; 352 iph->saddr = rt->rt_src; 353 iph->daddr = rt->rt_dst; 354 skb->nh.iph = iph; 355 /* Transport layer set skb->h.foo itself. */ 356 357 if (opt && opt->optlen) { 358 iph->ihl += opt->optlen >> 2; 359 ip_options_build(skb, opt, inet->daddr, rt, 0); 360 } 361 362 ip_select_ident_more(iph, &rt->u.dst, sk, 363 (skb_shinfo(skb)->gso_segs ?: 1) - 1); 364 365 /* Add an IP checksum. */ 366 ip_send_check(iph); 367 368 skb->priority = sk->sk_priority; 369 370 return NF_HOOK(PF_INET, NF_IP_LOCAL_OUT, skb, NULL, rt->u.dst.dev, 371 dst_output); 372 373 no_route: 374 IP_INC_STATS(IPSTATS_MIB_OUTNOROUTES); 375 kfree_skb(skb); 376 return -EHOSTUNREACH; 377 } 378 379 380 static void ip_copy_metadata(struct sk_buff *to, struct sk_buff *from) 381 { 382 to->pkt_type = from->pkt_type; 383 to->priority = from->priority; 384 to->protocol = from->protocol; 385 dst_release(to->dst); 386 to->dst = dst_clone(from->dst); 387 to->dev = from->dev; 388 389 /* Copy the flags to each fragment. */ 390 IPCB(to)->flags = IPCB(from)->flags; 391 392 #ifdef CONFIG_NET_SCHED 393 to->tc_index = from->tc_index; 394 #endif 395 #ifdef CONFIG_NETFILTER 396 to->nfmark = from->nfmark; 397 /* Connection association is same as pre-frag packet */ 398 nf_conntrack_put(to->nfct); 399 to->nfct = from->nfct; 400 nf_conntrack_get(to->nfct); 401 to->nfctinfo = from->nfctinfo; 402 #if defined(CONFIG_IP_VS) || defined(CONFIG_IP_VS_MODULE) 403 to->ipvs_property = from->ipvs_property; 404 #endif 405 #ifdef CONFIG_BRIDGE_NETFILTER 406 nf_bridge_put(to->nf_bridge); 407 to->nf_bridge = from->nf_bridge; 408 nf_bridge_get(to->nf_bridge); 409 #endif 410 #endif 411 skb_copy_secmark(to, from); 412 } 413 414 /* 415 * This IP datagram is too large to be sent in one piece. Break it up into 416 * smaller pieces (each of size equal to IP header plus 417 * a block of the data of the original IP data part) that will yet fit in a 418 * single device frame, and queue such a frame for sending. 419 */ 420 421 int ip_fragment(struct sk_buff *skb, int (*output)(struct sk_buff*)) 422 { 423 struct iphdr *iph; 424 int raw = 0; 425 int ptr; 426 struct net_device *dev; 427 struct sk_buff *skb2; 428 unsigned int mtu, hlen, left, len, ll_rs; 429 int offset; 430 __be16 not_last_frag; 431 struct rtable *rt = (struct rtable*)skb->dst; 432 int err = 0; 433 434 dev = rt->u.dst.dev; 435 436 /* 437 * Point into the IP datagram header. 438 */ 439 440 iph = skb->nh.iph; 441 442 if (unlikely((iph->frag_off & htons(IP_DF)) && !skb->local_df)) { 443 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, 444 htonl(dst_mtu(&rt->u.dst))); 445 kfree_skb(skb); 446 return -EMSGSIZE; 447 } 448 449 /* 450 * Setup starting values. 451 */ 452 453 hlen = iph->ihl * 4; 454 mtu = dst_mtu(&rt->u.dst) - hlen; /* Size of data space */ 455 IPCB(skb)->flags |= IPSKB_FRAG_COMPLETE; 456 457 /* When frag_list is given, use it. First, check its validity: 458 * some transformers could create wrong frag_list or break existing 459 * one, it is not prohibited. In this case fall back to copying. 460 * 461 * LATER: this step can be merged to real generation of fragments, 462 * we can switch to copy when see the first bad fragment. 463 */ 464 if (skb_shinfo(skb)->frag_list) { 465 struct sk_buff *frag; 466 int first_len = skb_pagelen(skb); 467 468 if (first_len - hlen > mtu || 469 ((first_len - hlen) & 7) || 470 (iph->frag_off & htons(IP_MF|IP_OFFSET)) || 471 skb_cloned(skb)) 472 goto slow_path; 473 474 for (frag = skb_shinfo(skb)->frag_list; frag; frag = frag->next) { 475 /* Correct geometry. */ 476 if (frag->len > mtu || 477 ((frag->len & 7) && frag->next) || 478 skb_headroom(frag) < hlen) 479 goto slow_path; 480 481 /* Partially cloned skb? */ 482 if (skb_shared(frag)) 483 goto slow_path; 484 485 BUG_ON(frag->sk); 486 if (skb->sk) { 487 sock_hold(skb->sk); 488 frag->sk = skb->sk; 489 frag->destructor = sock_wfree; 490 skb->truesize -= frag->truesize; 491 } 492 } 493 494 /* Everything is OK. Generate! */ 495 496 err = 0; 497 offset = 0; 498 frag = skb_shinfo(skb)->frag_list; 499 skb_shinfo(skb)->frag_list = NULL; 500 skb->data_len = first_len - skb_headlen(skb); 501 skb->len = first_len; 502 iph->tot_len = htons(first_len); 503 iph->frag_off = htons(IP_MF); 504 ip_send_check(iph); 505 506 for (;;) { 507 /* Prepare header of the next frame, 508 * before previous one went down. */ 509 if (frag) { 510 frag->ip_summed = CHECKSUM_NONE; 511 frag->h.raw = frag->data; 512 frag->nh.raw = __skb_push(frag, hlen); 513 memcpy(frag->nh.raw, iph, hlen); 514 iph = frag->nh.iph; 515 iph->tot_len = htons(frag->len); 516 ip_copy_metadata(frag, skb); 517 if (offset == 0) 518 ip_options_fragment(frag); 519 offset += skb->len - hlen; 520 iph->frag_off = htons(offset>>3); 521 if (frag->next != NULL) 522 iph->frag_off |= htons(IP_MF); 523 /* Ready, complete checksum */ 524 ip_send_check(iph); 525 } 526 527 err = output(skb); 528 529 if (err || !frag) 530 break; 531 532 skb = frag; 533 frag = skb->next; 534 skb->next = NULL; 535 } 536 537 if (err == 0) { 538 IP_INC_STATS(IPSTATS_MIB_FRAGOKS); 539 return 0; 540 } 541 542 while (frag) { 543 skb = frag->next; 544 kfree_skb(frag); 545 frag = skb; 546 } 547 IP_INC_STATS(IPSTATS_MIB_FRAGFAILS); 548 return err; 549 } 550 551 slow_path: 552 left = skb->len - hlen; /* Space per frame */ 553 ptr = raw + hlen; /* Where to start from */ 554 555 #ifdef CONFIG_BRIDGE_NETFILTER 556 /* for bridged IP traffic encapsulated inside f.e. a vlan header, 557 * we need to make room for the encapsulating header */ 558 ll_rs = LL_RESERVED_SPACE_EXTRA(rt->u.dst.dev, nf_bridge_pad(skb)); 559 mtu -= nf_bridge_pad(skb); 560 #else 561 ll_rs = LL_RESERVED_SPACE(rt->u.dst.dev); 562 #endif 563 /* 564 * Fragment the datagram. 565 */ 566 567 offset = (ntohs(iph->frag_off) & IP_OFFSET) << 3; 568 not_last_frag = iph->frag_off & htons(IP_MF); 569 570 /* 571 * Keep copying data until we run out. 572 */ 573 574 while(left > 0) { 575 len = left; 576 /* IF: it doesn't fit, use 'mtu' - the data space left */ 577 if (len > mtu) 578 len = mtu; 579 /* IF: we are not sending upto and including the packet end 580 then align the next start on an eight byte boundary */ 581 if (len < left) { 582 len &= ~7; 583 } 584 /* 585 * Allocate buffer. 586 */ 587 588 if ((skb2 = alloc_skb(len+hlen+ll_rs, GFP_ATOMIC)) == NULL) { 589 NETDEBUG(KERN_INFO "IP: frag: no memory for new fragment!\n"); 590 err = -ENOMEM; 591 goto fail; 592 } 593 594 /* 595 * Set up data on packet 596 */ 597 598 ip_copy_metadata(skb2, skb); 599 skb_reserve(skb2, ll_rs); 600 skb_put(skb2, len + hlen); 601 skb2->nh.raw = skb2->data; 602 skb2->h.raw = skb2->data + hlen; 603 604 /* 605 * Charge the memory for the fragment to any owner 606 * it might possess 607 */ 608 609 if (skb->sk) 610 skb_set_owner_w(skb2, skb->sk); 611 612 /* 613 * Copy the packet header into the new buffer. 614 */ 615 616 memcpy(skb2->nh.raw, skb->data, hlen); 617 618 /* 619 * Copy a block of the IP datagram. 620 */ 621 if (skb_copy_bits(skb, ptr, skb2->h.raw, len)) 622 BUG(); 623 left -= len; 624 625 /* 626 * Fill in the new header fields. 627 */ 628 iph = skb2->nh.iph; 629 iph->frag_off = htons((offset >> 3)); 630 631 /* ANK: dirty, but effective trick. Upgrade options only if 632 * the segment to be fragmented was THE FIRST (otherwise, 633 * options are already fixed) and make it ONCE 634 * on the initial skb, so that all the following fragments 635 * will inherit fixed options. 636 */ 637 if (offset == 0) 638 ip_options_fragment(skb); 639 640 /* 641 * Added AC : If we are fragmenting a fragment that's not the 642 * last fragment then keep MF on each bit 643 */ 644 if (left > 0 || not_last_frag) 645 iph->frag_off |= htons(IP_MF); 646 ptr += len; 647 offset += len; 648 649 /* 650 * Put this fragment into the sending queue. 651 */ 652 653 IP_INC_STATS(IPSTATS_MIB_FRAGCREATES); 654 655 iph->tot_len = htons(len + hlen); 656 657 ip_send_check(iph); 658 659 err = output(skb2); 660 if (err) 661 goto fail; 662 } 663 kfree_skb(skb); 664 IP_INC_STATS(IPSTATS_MIB_FRAGOKS); 665 return err; 666 667 fail: 668 kfree_skb(skb); 669 IP_INC_STATS(IPSTATS_MIB_FRAGFAILS); 670 return err; 671 } 672 673 EXPORT_SYMBOL(ip_fragment); 674 675 int 676 ip_generic_getfrag(void *from, char *to, int offset, int len, int odd, struct sk_buff *skb) 677 { 678 struct iovec *iov = from; 679 680 if (skb->ip_summed == CHECKSUM_HW) { 681 if (memcpy_fromiovecend(to, iov, offset, len) < 0) 682 return -EFAULT; 683 } else { 684 unsigned int csum = 0; 685 if (csum_partial_copy_fromiovecend(to, iov, offset, len, &csum) < 0) 686 return -EFAULT; 687 skb->csum = csum_block_add(skb->csum, csum, odd); 688 } 689 return 0; 690 } 691 692 static inline unsigned int 693 csum_page(struct page *page, int offset, int copy) 694 { 695 char *kaddr; 696 unsigned int csum; 697 kaddr = kmap(page); 698 csum = csum_partial(kaddr + offset, copy, 0); 699 kunmap(page); 700 return csum; 701 } 702 703 static inline int ip_ufo_append_data(struct sock *sk, 704 int getfrag(void *from, char *to, int offset, int len, 705 int odd, struct sk_buff *skb), 706 void *from, int length, int hh_len, int fragheaderlen, 707 int transhdrlen, int mtu,unsigned int flags) 708 { 709 struct sk_buff *skb; 710 int err; 711 712 /* There is support for UDP fragmentation offload by network 713 * device, so create one single skb packet containing complete 714 * udp datagram 715 */ 716 if ((skb = skb_peek_tail(&sk->sk_write_queue)) == NULL) { 717 skb = sock_alloc_send_skb(sk, 718 hh_len + fragheaderlen + transhdrlen + 20, 719 (flags & MSG_DONTWAIT), &err); 720 721 if (skb == NULL) 722 return err; 723 724 /* reserve space for Hardware header */ 725 skb_reserve(skb, hh_len); 726 727 /* create space for UDP/IP header */ 728 skb_put(skb,fragheaderlen + transhdrlen); 729 730 /* initialize network header pointer */ 731 skb->nh.raw = skb->data; 732 733 /* initialize protocol header pointer */ 734 skb->h.raw = skb->data + fragheaderlen; 735 736 skb->ip_summed = CHECKSUM_HW; 737 skb->csum = 0; 738 sk->sk_sndmsg_off = 0; 739 } 740 741 err = skb_append_datato_frags(sk,skb, getfrag, from, 742 (length - transhdrlen)); 743 if (!err) { 744 /* specify the length of each IP datagram fragment*/ 745 skb_shinfo(skb)->gso_size = mtu - fragheaderlen; 746 skb_shinfo(skb)->gso_type = SKB_GSO_UDP; 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_ALL_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)->gso_size = mtu - fragheaderlen; 1091 skb_shinfo(skb)->gso_type = SKB_GSO_UDP; 1092 } 1093 1094 1095 while (size > 0) { 1096 int i; 1097 1098 if (skb_is_gso(skb)) 1099 len = size; 1100 else { 1101 1102 /* Check if the remaining data fits into current packet. */ 1103 len = mtu - skb->len; 1104 if (len < size) 1105 len = maxfraglen - skb->len; 1106 } 1107 if (len <= 0) { 1108 struct sk_buff *skb_prev; 1109 char *data; 1110 struct iphdr *iph; 1111 int alloclen; 1112 1113 skb_prev = skb; 1114 fraggap = skb_prev->len - maxfraglen; 1115 1116 alloclen = fragheaderlen + hh_len + fraggap + 15; 1117 skb = sock_wmalloc(sk, alloclen, 1, sk->sk_allocation); 1118 if (unlikely(!skb)) { 1119 err = -ENOBUFS; 1120 goto error; 1121 } 1122 1123 /* 1124 * Fill in the control structures 1125 */ 1126 skb->ip_summed = CHECKSUM_NONE; 1127 skb->csum = 0; 1128 skb_reserve(skb, hh_len); 1129 1130 /* 1131 * Find where to start putting bytes. 1132 */ 1133 data = skb_put(skb, fragheaderlen + fraggap); 1134 skb->nh.iph = iph = (struct iphdr *)data; 1135 data += fragheaderlen; 1136 skb->h.raw = data; 1137 1138 if (fraggap) { 1139 skb->csum = skb_copy_and_csum_bits( 1140 skb_prev, maxfraglen, 1141 data, fraggap, 0); 1142 skb_prev->csum = csum_sub(skb_prev->csum, 1143 skb->csum); 1144 skb_trim(skb_prev, maxfraglen); 1145 } 1146 1147 /* 1148 * Put the packet on the pending queue. 1149 */ 1150 __skb_queue_tail(&sk->sk_write_queue, skb); 1151 continue; 1152 } 1153 1154 i = skb_shinfo(skb)->nr_frags; 1155 if (len > size) 1156 len = size; 1157 if (skb_can_coalesce(skb, i, page, offset)) { 1158 skb_shinfo(skb)->frags[i-1].size += len; 1159 } else if (i < MAX_SKB_FRAGS) { 1160 get_page(page); 1161 skb_fill_page_desc(skb, i, page, offset, len); 1162 } else { 1163 err = -EMSGSIZE; 1164 goto error; 1165 } 1166 1167 if (skb->ip_summed == CHECKSUM_NONE) { 1168 unsigned int csum; 1169 csum = csum_page(page, offset, len); 1170 skb->csum = csum_block_add(skb->csum, csum, skb->len); 1171 } 1172 1173 skb->len += len; 1174 skb->data_len += len; 1175 offset += len; 1176 size -= len; 1177 } 1178 return 0; 1179 1180 error: 1181 inet->cork.length -= size; 1182 IP_INC_STATS(IPSTATS_MIB_OUTDISCARDS); 1183 return err; 1184 } 1185 1186 /* 1187 * Combined all pending IP fragments on the socket as one IP datagram 1188 * and push them out. 1189 */ 1190 int ip_push_pending_frames(struct sock *sk) 1191 { 1192 struct sk_buff *skb, *tmp_skb; 1193 struct sk_buff **tail_skb; 1194 struct inet_sock *inet = inet_sk(sk); 1195 struct ip_options *opt = NULL; 1196 struct rtable *rt = inet->cork.rt; 1197 struct iphdr *iph; 1198 __be16 df = 0; 1199 __u8 ttl; 1200 int err = 0; 1201 1202 if ((skb = __skb_dequeue(&sk->sk_write_queue)) == NULL) 1203 goto out; 1204 tail_skb = &(skb_shinfo(skb)->frag_list); 1205 1206 /* move skb->data to ip header from ext header */ 1207 if (skb->data < skb->nh.raw) 1208 __skb_pull(skb, skb->nh.raw - skb->data); 1209 while ((tmp_skb = __skb_dequeue(&sk->sk_write_queue)) != NULL) { 1210 __skb_pull(tmp_skb, skb->h.raw - skb->nh.raw); 1211 *tail_skb = tmp_skb; 1212 tail_skb = &(tmp_skb->next); 1213 skb->len += tmp_skb->len; 1214 skb->data_len += tmp_skb->len; 1215 skb->truesize += tmp_skb->truesize; 1216 __sock_put(tmp_skb->sk); 1217 tmp_skb->destructor = NULL; 1218 tmp_skb->sk = NULL; 1219 } 1220 1221 /* Unless user demanded real pmtu discovery (IP_PMTUDISC_DO), we allow 1222 * to fragment the frame generated here. No matter, what transforms 1223 * how transforms change size of the packet, it will come out. 1224 */ 1225 if (inet->pmtudisc != IP_PMTUDISC_DO) 1226 skb->local_df = 1; 1227 1228 /* DF bit is set when we want to see DF on outgoing frames. 1229 * If local_df is set too, we still allow to fragment this frame 1230 * locally. */ 1231 if (inet->pmtudisc == IP_PMTUDISC_DO || 1232 (skb->len <= dst_mtu(&rt->u.dst) && 1233 ip_dont_fragment(sk, &rt->u.dst))) 1234 df = htons(IP_DF); 1235 1236 if (inet->cork.flags & IPCORK_OPT) 1237 opt = inet->cork.opt; 1238 1239 if (rt->rt_type == RTN_MULTICAST) 1240 ttl = inet->mc_ttl; 1241 else 1242 ttl = ip_select_ttl(inet, &rt->u.dst); 1243 1244 iph = (struct iphdr *)skb->data; 1245 iph->version = 4; 1246 iph->ihl = 5; 1247 if (opt) { 1248 iph->ihl += opt->optlen>>2; 1249 ip_options_build(skb, opt, inet->cork.addr, rt, 0); 1250 } 1251 iph->tos = inet->tos; 1252 iph->tot_len = htons(skb->len); 1253 iph->frag_off = df; 1254 ip_select_ident(iph, &rt->u.dst, sk); 1255 iph->ttl = ttl; 1256 iph->protocol = sk->sk_protocol; 1257 iph->saddr = rt->rt_src; 1258 iph->daddr = rt->rt_dst; 1259 ip_send_check(iph); 1260 1261 skb->priority = sk->sk_priority; 1262 skb->dst = dst_clone(&rt->u.dst); 1263 1264 /* Netfilter gets whole the not fragmented skb. */ 1265 err = NF_HOOK(PF_INET, NF_IP_LOCAL_OUT, skb, NULL, 1266 skb->dst->dev, dst_output); 1267 if (err) { 1268 if (err > 0) 1269 err = inet->recverr ? net_xmit_errno(err) : 0; 1270 if (err) 1271 goto error; 1272 } 1273 1274 out: 1275 inet->cork.flags &= ~IPCORK_OPT; 1276 kfree(inet->cork.opt); 1277 inet->cork.opt = NULL; 1278 if (inet->cork.rt) { 1279 ip_rt_put(inet->cork.rt); 1280 inet->cork.rt = NULL; 1281 } 1282 return err; 1283 1284 error: 1285 IP_INC_STATS(IPSTATS_MIB_OUTDISCARDS); 1286 goto out; 1287 } 1288 1289 /* 1290 * Throw away all pending data on the socket. 1291 */ 1292 void ip_flush_pending_frames(struct sock *sk) 1293 { 1294 struct inet_sock *inet = inet_sk(sk); 1295 struct sk_buff *skb; 1296 1297 while ((skb = __skb_dequeue_tail(&sk->sk_write_queue)) != NULL) 1298 kfree_skb(skb); 1299 1300 inet->cork.flags &= ~IPCORK_OPT; 1301 kfree(inet->cork.opt); 1302 inet->cork.opt = NULL; 1303 if (inet->cork.rt) { 1304 ip_rt_put(inet->cork.rt); 1305 inet->cork.rt = NULL; 1306 } 1307 } 1308 1309 1310 /* 1311 * Fetch data from kernel space and fill in checksum if needed. 1312 */ 1313 static int ip_reply_glue_bits(void *dptr, char *to, int offset, 1314 int len, int odd, struct sk_buff *skb) 1315 { 1316 unsigned int csum; 1317 1318 csum = csum_partial_copy_nocheck(dptr+offset, to, len, 0); 1319 skb->csum = csum_block_add(skb->csum, csum, odd); 1320 return 0; 1321 } 1322 1323 /* 1324 * Generic function to send a packet as reply to another packet. 1325 * Used to send TCP resets so far. ICMP should use this function too. 1326 * 1327 * Should run single threaded per socket because it uses the sock 1328 * structure to pass arguments. 1329 * 1330 * LATER: switch from ip_build_xmit to ip_append_* 1331 */ 1332 void ip_send_reply(struct sock *sk, struct sk_buff *skb, struct ip_reply_arg *arg, 1333 unsigned int len) 1334 { 1335 struct inet_sock *inet = inet_sk(sk); 1336 struct { 1337 struct ip_options opt; 1338 char data[40]; 1339 } replyopts; 1340 struct ipcm_cookie ipc; 1341 u32 daddr; 1342 struct rtable *rt = (struct rtable*)skb->dst; 1343 1344 if (ip_options_echo(&replyopts.opt, skb)) 1345 return; 1346 1347 daddr = ipc.addr = rt->rt_src; 1348 ipc.opt = NULL; 1349 1350 if (replyopts.opt.optlen) { 1351 ipc.opt = &replyopts.opt; 1352 1353 if (ipc.opt->srr) 1354 daddr = replyopts.opt.faddr; 1355 } 1356 1357 { 1358 struct flowi fl = { .nl_u = { .ip4_u = 1359 { .daddr = daddr, 1360 .saddr = rt->rt_spec_dst, 1361 .tos = RT_TOS(skb->nh.iph->tos) } }, 1362 /* Not quite clean, but right. */ 1363 .uli_u = { .ports = 1364 { .sport = skb->h.th->dest, 1365 .dport = skb->h.th->source } }, 1366 .proto = sk->sk_protocol }; 1367 if (ip_route_output_key(&rt, &fl)) 1368 return; 1369 } 1370 1371 /* And let IP do all the hard work. 1372 1373 This chunk is not reenterable, hence spinlock. 1374 Note that it uses the fact, that this function is called 1375 with locally disabled BH and that sk cannot be already spinlocked. 1376 */ 1377 bh_lock_sock(sk); 1378 inet->tos = skb->nh.iph->tos; 1379 sk->sk_priority = skb->priority; 1380 sk->sk_protocol = skb->nh.iph->protocol; 1381 ip_append_data(sk, ip_reply_glue_bits, arg->iov->iov_base, len, 0, 1382 &ipc, rt, MSG_DONTWAIT); 1383 if ((skb = skb_peek(&sk->sk_write_queue)) != NULL) { 1384 if (arg->csumoffset >= 0) 1385 *((u16 *)skb->h.raw + arg->csumoffset) = csum_fold(csum_add(skb->csum, arg->csum)); 1386 skb->ip_summed = CHECKSUM_NONE; 1387 ip_push_pending_frames(sk); 1388 } 1389 1390 bh_unlock_sock(sk); 1391 1392 ip_rt_put(rt); 1393 } 1394 1395 void __init ip_init(void) 1396 { 1397 ip_rt_init(); 1398 inet_initpeers(); 1399 1400 #if defined(CONFIG_IP_MULTICAST) && defined(CONFIG_PROC_FS) 1401 igmp_mc_proc_init(); 1402 #endif 1403 } 1404 1405 EXPORT_SYMBOL(ip_generic_getfrag); 1406 EXPORT_SYMBOL(ip_queue_xmit); 1407 EXPORT_SYMBOL(ip_send_check); 1408