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 * Authors: Ross Biro 9 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> 10 * Donald Becker, <becker@super.org> 11 * Alan Cox, <Alan.Cox@linux.org> 12 * Richard Underwood 13 * Stefan Becker, <stefanb@yello.ping.de> 14 * Jorge Cwik, <jorge@laser.satlink.net> 15 * Arnt Gulbrandsen, <agulbra@nvg.unit.no> 16 * Hirokazu Takahashi, <taka@valinux.co.jp> 17 * 18 * See ip_input.c for original log 19 * 20 * Fixes: 21 * Alan Cox : Missing nonblock feature in ip_build_xmit. 22 * Mike Kilburn : htons() missing in ip_build_xmit. 23 * Bradford Johnson: Fix faulty handling of some frames when 24 * no route is found. 25 * Alexander Demenshin: Missing sk/skb free in ip_queue_xmit 26 * (in case if packet not accepted by 27 * output firewall rules) 28 * Mike McLagan : Routing by source 29 * Alexey Kuznetsov: use new route cache 30 * Andi Kleen: Fix broken PMTU recovery and remove 31 * some redundant tests. 32 * Vitaly E. Lavrov : Transparent proxy revived after year coma. 33 * Andi Kleen : Replace ip_reply with ip_send_reply. 34 * Andi Kleen : Split fast and slow ip_build_xmit path 35 * for decreased register pressure on x86 36 * and more readibility. 37 * Marc Boucher : When call_out_firewall returns FW_QUEUE, 38 * silently drop skb instead of failing with -EPERM. 39 * Detlev Wengorz : Copy protocol for fragments. 40 * Hirokazu Takahashi: HW checksumming for outgoing UDP 41 * datagrams. 42 * Hirokazu Takahashi: sendfile() on UDP works now. 43 */ 44 45 #include <asm/uaccess.h> 46 #include <asm/system.h> 47 #include <linux/module.h> 48 #include <linux/types.h> 49 #include <linux/kernel.h> 50 #include <linux/mm.h> 51 #include <linux/string.h> 52 #include <linux/errno.h> 53 #include <linux/highmem.h> 54 55 #include <linux/socket.h> 56 #include <linux/sockios.h> 57 #include <linux/in.h> 58 #include <linux/inet.h> 59 #include <linux/netdevice.h> 60 #include <linux/etherdevice.h> 61 #include <linux/proc_fs.h> 62 #include <linux/stat.h> 63 #include <linux/init.h> 64 65 #include <net/snmp.h> 66 #include <net/ip.h> 67 #include <net/protocol.h> 68 #include <net/route.h> 69 #include <net/xfrm.h> 70 #include <linux/skbuff.h> 71 #include <net/sock.h> 72 #include <net/arp.h> 73 #include <net/icmp.h> 74 #include <net/checksum.h> 75 #include <net/inetpeer.h> 76 #include <linux/igmp.h> 77 #include <linux/netfilter_ipv4.h> 78 #include <linux/netfilter_bridge.h> 79 #include <linux/mroute.h> 80 #include <linux/netlink.h> 81 #include <linux/tcp.h> 82 83 int sysctl_ip_default_ttl __read_mostly = IPDEFTTL; 84 85 /* Generate a checksum for an outgoing IP datagram. */ 86 __inline__ void ip_send_check(struct iphdr *iph) 87 { 88 iph->check = 0; 89 iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl); 90 } 91 92 int __ip_local_out(struct sk_buff *skb) 93 { 94 struct iphdr *iph = ip_hdr(skb); 95 96 iph->tot_len = htons(skb->len); 97 ip_send_check(iph); 98 return nf_hook(PF_INET, NF_INET_LOCAL_OUT, skb, NULL, skb->dst->dev, 99 dst_output); 100 } 101 102 int ip_local_out(struct sk_buff *skb) 103 { 104 int err; 105 106 err = __ip_local_out(skb); 107 if (likely(err == 1)) 108 err = dst_output(skb); 109 110 return err; 111 } 112 EXPORT_SYMBOL_GPL(ip_local_out); 113 114 /* dev_loopback_xmit for use with netfilter. */ 115 static int ip_dev_loopback_xmit(struct sk_buff *newskb) 116 { 117 skb_reset_mac_header(newskb); 118 __skb_pull(newskb, skb_network_offset(newskb)); 119 newskb->pkt_type = PACKET_LOOPBACK; 120 newskb->ip_summed = CHECKSUM_UNNECESSARY; 121 WARN_ON(!newskb->dst); 122 netif_rx(newskb); 123 return 0; 124 } 125 126 static inline int ip_select_ttl(struct inet_sock *inet, struct dst_entry *dst) 127 { 128 int ttl = inet->uc_ttl; 129 130 if (ttl < 0) 131 ttl = dst_metric(dst, RTAX_HOPLIMIT); 132 return ttl; 133 } 134 135 /* 136 * Add an ip header to a skbuff and send it out. 137 * 138 */ 139 int ip_build_and_send_pkt(struct sk_buff *skb, struct sock *sk, 140 __be32 saddr, __be32 daddr, struct ip_options *opt) 141 { 142 struct inet_sock *inet = inet_sk(sk); 143 struct rtable *rt = skb->rtable; 144 struct iphdr *iph; 145 146 /* Build the IP header. */ 147 skb_push(skb, sizeof(struct iphdr) + (opt ? opt->optlen : 0)); 148 skb_reset_network_header(skb); 149 iph = ip_hdr(skb); 150 iph->version = 4; 151 iph->ihl = 5; 152 iph->tos = inet->tos; 153 if (ip_dont_fragment(sk, &rt->u.dst)) 154 iph->frag_off = htons(IP_DF); 155 else 156 iph->frag_off = 0; 157 iph->ttl = ip_select_ttl(inet, &rt->u.dst); 158 iph->daddr = rt->rt_dst; 159 iph->saddr = rt->rt_src; 160 iph->protocol = sk->sk_protocol; 161 ip_select_ident(iph, &rt->u.dst, sk); 162 163 if (opt && opt->optlen) { 164 iph->ihl += opt->optlen>>2; 165 ip_options_build(skb, opt, daddr, rt, 0); 166 } 167 168 skb->priority = sk->sk_priority; 169 skb->mark = sk->sk_mark; 170 171 /* Send it out. */ 172 return ip_local_out(skb); 173 } 174 175 EXPORT_SYMBOL_GPL(ip_build_and_send_pkt); 176 177 static inline int ip_finish_output2(struct sk_buff *skb) 178 { 179 struct dst_entry *dst = skb->dst; 180 struct rtable *rt = (struct rtable *)dst; 181 struct net_device *dev = dst->dev; 182 unsigned int hh_len = LL_RESERVED_SPACE(dev); 183 184 if (rt->rt_type == RTN_MULTICAST) 185 IP_INC_STATS(dev_net(dev), IPSTATS_MIB_OUTMCASTPKTS); 186 else if (rt->rt_type == RTN_BROADCAST) 187 IP_INC_STATS(dev_net(dev), IPSTATS_MIB_OUTBCASTPKTS); 188 189 /* Be paranoid, rather than too clever. */ 190 if (unlikely(skb_headroom(skb) < hh_len && dev->header_ops)) { 191 struct sk_buff *skb2; 192 193 skb2 = skb_realloc_headroom(skb, LL_RESERVED_SPACE(dev)); 194 if (skb2 == NULL) { 195 kfree_skb(skb); 196 return -ENOMEM; 197 } 198 if (skb->sk) 199 skb_set_owner_w(skb2, skb->sk); 200 kfree_skb(skb); 201 skb = skb2; 202 } 203 204 if (dst->hh) 205 return neigh_hh_output(dst->hh, skb); 206 else if (dst->neighbour) 207 return dst->neighbour->output(skb); 208 209 if (net_ratelimit()) 210 printk(KERN_DEBUG "ip_finish_output2: No header cache and no neighbour!\n"); 211 kfree_skb(skb); 212 return -EINVAL; 213 } 214 215 static inline int ip_skb_dst_mtu(struct sk_buff *skb) 216 { 217 struct inet_sock *inet = skb->sk ? inet_sk(skb->sk) : NULL; 218 219 return (inet && inet->pmtudisc == IP_PMTUDISC_PROBE) ? 220 skb->dst->dev->mtu : dst_mtu(skb->dst); 221 } 222 223 static int ip_finish_output(struct sk_buff *skb) 224 { 225 #if defined(CONFIG_NETFILTER) && defined(CONFIG_XFRM) 226 /* Policy lookup after SNAT yielded a new policy */ 227 if (skb->dst->xfrm != NULL) { 228 IPCB(skb)->flags |= IPSKB_REROUTED; 229 return dst_output(skb); 230 } 231 #endif 232 if (skb->len > ip_skb_dst_mtu(skb) && !skb_is_gso(skb)) 233 return ip_fragment(skb, ip_finish_output2); 234 else 235 return ip_finish_output2(skb); 236 } 237 238 int ip_mc_output(struct sk_buff *skb) 239 { 240 struct sock *sk = skb->sk; 241 struct rtable *rt = skb->rtable; 242 struct net_device *dev = rt->u.dst.dev; 243 244 /* 245 * If the indicated interface is up and running, send the packet. 246 */ 247 IP_INC_STATS(dev_net(dev), IPSTATS_MIB_OUTREQUESTS); 248 249 skb->dev = dev; 250 skb->protocol = htons(ETH_P_IP); 251 252 /* 253 * Multicasts are looped back for other local users 254 */ 255 256 if (rt->rt_flags&RTCF_MULTICAST) { 257 if ((!sk || inet_sk(sk)->mc_loop) 258 #ifdef CONFIG_IP_MROUTE 259 /* Small optimization: do not loopback not local frames, 260 which returned after forwarding; they will be dropped 261 by ip_mr_input in any case. 262 Note, that local frames are looped back to be delivered 263 to local recipients. 264 265 This check is duplicated in ip_mr_input at the moment. 266 */ 267 && ((rt->rt_flags&RTCF_LOCAL) || !(IPCB(skb)->flags&IPSKB_FORWARDED)) 268 #endif 269 ) { 270 struct sk_buff *newskb = skb_clone(skb, GFP_ATOMIC); 271 if (newskb) 272 NF_HOOK(PF_INET, NF_INET_POST_ROUTING, newskb, 273 NULL, newskb->dev, 274 ip_dev_loopback_xmit); 275 } 276 277 /* Multicasts with ttl 0 must not go beyond the host */ 278 279 if (ip_hdr(skb)->ttl == 0) { 280 kfree_skb(skb); 281 return 0; 282 } 283 } 284 285 if (rt->rt_flags&RTCF_BROADCAST) { 286 struct sk_buff *newskb = skb_clone(skb, GFP_ATOMIC); 287 if (newskb) 288 NF_HOOK(PF_INET, NF_INET_POST_ROUTING, newskb, NULL, 289 newskb->dev, ip_dev_loopback_xmit); 290 } 291 292 return NF_HOOK_COND(PF_INET, NF_INET_POST_ROUTING, skb, NULL, skb->dev, 293 ip_finish_output, 294 !(IPCB(skb)->flags & IPSKB_REROUTED)); 295 } 296 297 int ip_output(struct sk_buff *skb) 298 { 299 struct net_device *dev = skb->dst->dev; 300 301 IP_INC_STATS(dev_net(dev), IPSTATS_MIB_OUTREQUESTS); 302 303 skb->dev = dev; 304 skb->protocol = htons(ETH_P_IP); 305 306 return NF_HOOK_COND(PF_INET, NF_INET_POST_ROUTING, skb, NULL, dev, 307 ip_finish_output, 308 !(IPCB(skb)->flags & IPSKB_REROUTED)); 309 } 310 311 int ip_queue_xmit(struct sk_buff *skb, int ipfragok) 312 { 313 struct sock *sk = skb->sk; 314 struct inet_sock *inet = inet_sk(sk); 315 struct ip_options *opt = inet->opt; 316 struct rtable *rt; 317 struct iphdr *iph; 318 319 /* Skip all of this if the packet is already routed, 320 * f.e. by something like SCTP. 321 */ 322 rt = skb->rtable; 323 if (rt != NULL) 324 goto packet_routed; 325 326 /* Make sure we can route this packet. */ 327 rt = (struct rtable *)__sk_dst_check(sk, 0); 328 if (rt == NULL) { 329 __be32 daddr; 330 331 /* Use correct destination address if we have options. */ 332 daddr = inet->daddr; 333 if(opt && opt->srr) 334 daddr = opt->faddr; 335 336 { 337 struct flowi fl = { .oif = sk->sk_bound_dev_if, 338 .nl_u = { .ip4_u = 339 { .daddr = daddr, 340 .saddr = inet->saddr, 341 .tos = RT_CONN_FLAGS(sk) } }, 342 .proto = sk->sk_protocol, 343 .uli_u = { .ports = 344 { .sport = inet->sport, 345 .dport = inet->dport } } }; 346 347 /* If this fails, retransmit mechanism of transport layer will 348 * keep trying until route appears or the connection times 349 * itself out. 350 */ 351 security_sk_classify_flow(sk, &fl); 352 if (ip_route_output_flow(sock_net(sk), &rt, &fl, sk, 0)) 353 goto no_route; 354 } 355 sk_setup_caps(sk, &rt->u.dst); 356 } 357 skb->dst = dst_clone(&rt->u.dst); 358 359 packet_routed: 360 if (opt && opt->is_strictroute && rt->rt_dst != rt->rt_gateway) 361 goto no_route; 362 363 /* OK, we know where to send it, allocate and build IP header. */ 364 skb_push(skb, sizeof(struct iphdr) + (opt ? opt->optlen : 0)); 365 skb_reset_network_header(skb); 366 iph = ip_hdr(skb); 367 *((__be16 *)iph) = htons((4 << 12) | (5 << 8) | (inet->tos & 0xff)); 368 if (ip_dont_fragment(sk, &rt->u.dst) && !ipfragok) 369 iph->frag_off = htons(IP_DF); 370 else 371 iph->frag_off = 0; 372 iph->ttl = ip_select_ttl(inet, &rt->u.dst); 373 iph->protocol = sk->sk_protocol; 374 iph->saddr = rt->rt_src; 375 iph->daddr = rt->rt_dst; 376 /* Transport layer set skb->h.foo itself. */ 377 378 if (opt && opt->optlen) { 379 iph->ihl += opt->optlen >> 2; 380 ip_options_build(skb, opt, inet->daddr, rt, 0); 381 } 382 383 ip_select_ident_more(iph, &rt->u.dst, sk, 384 (skb_shinfo(skb)->gso_segs ?: 1) - 1); 385 386 skb->priority = sk->sk_priority; 387 skb->mark = sk->sk_mark; 388 389 return ip_local_out(skb); 390 391 no_route: 392 IP_INC_STATS(sock_net(sk), IPSTATS_MIB_OUTNOROUTES); 393 kfree_skb(skb); 394 return -EHOSTUNREACH; 395 } 396 397 398 static void ip_copy_metadata(struct sk_buff *to, struct sk_buff *from) 399 { 400 to->pkt_type = from->pkt_type; 401 to->priority = from->priority; 402 to->protocol = from->protocol; 403 dst_release(to->dst); 404 to->dst = dst_clone(from->dst); 405 to->dev = from->dev; 406 to->mark = from->mark; 407 408 /* Copy the flags to each fragment. */ 409 IPCB(to)->flags = IPCB(from)->flags; 410 411 #ifdef CONFIG_NET_SCHED 412 to->tc_index = from->tc_index; 413 #endif 414 nf_copy(to, from); 415 #if defined(CONFIG_NETFILTER_XT_TARGET_TRACE) || \ 416 defined(CONFIG_NETFILTER_XT_TARGET_TRACE_MODULE) 417 to->nf_trace = from->nf_trace; 418 #endif 419 #if defined(CONFIG_IP_VS) || defined(CONFIG_IP_VS_MODULE) 420 to->ipvs_property = from->ipvs_property; 421 #endif 422 skb_copy_secmark(to, from); 423 } 424 425 /* 426 * This IP datagram is too large to be sent in one piece. Break it up into 427 * smaller pieces (each of size equal to IP header plus 428 * a block of the data of the original IP data part) that will yet fit in a 429 * single device frame, and queue such a frame for sending. 430 */ 431 432 int ip_fragment(struct sk_buff *skb, int (*output)(struct sk_buff*)) 433 { 434 struct iphdr *iph; 435 int raw = 0; 436 int ptr; 437 struct net_device *dev; 438 struct sk_buff *skb2; 439 unsigned int mtu, hlen, left, len, ll_rs, pad; 440 int offset; 441 __be16 not_last_frag; 442 struct rtable *rt = skb->rtable; 443 int err = 0; 444 445 dev = rt->u.dst.dev; 446 447 /* 448 * Point into the IP datagram header. 449 */ 450 451 iph = ip_hdr(skb); 452 453 if (unlikely((iph->frag_off & htons(IP_DF)) && !skb->local_df)) { 454 IP_INC_STATS(dev_net(dev), IPSTATS_MIB_FRAGFAILS); 455 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, 456 htonl(ip_skb_dst_mtu(skb))); 457 kfree_skb(skb); 458 return -EMSGSIZE; 459 } 460 461 /* 462 * Setup starting values. 463 */ 464 465 hlen = iph->ihl * 4; 466 mtu = dst_mtu(&rt->u.dst) - hlen; /* Size of data space */ 467 IPCB(skb)->flags |= IPSKB_FRAG_COMPLETE; 468 469 /* When frag_list is given, use it. First, check its validity: 470 * some transformers could create wrong frag_list or break existing 471 * one, it is not prohibited. In this case fall back to copying. 472 * 473 * LATER: this step can be merged to real generation of fragments, 474 * we can switch to copy when see the first bad fragment. 475 */ 476 if (skb_shinfo(skb)->frag_list) { 477 struct sk_buff *frag; 478 int first_len = skb_pagelen(skb); 479 int truesizes = 0; 480 481 if (first_len - hlen > mtu || 482 ((first_len - hlen) & 7) || 483 (iph->frag_off & htons(IP_MF|IP_OFFSET)) || 484 skb_cloned(skb)) 485 goto slow_path; 486 487 for (frag = skb_shinfo(skb)->frag_list; frag; frag = frag->next) { 488 /* Correct geometry. */ 489 if (frag->len > mtu || 490 ((frag->len & 7) && frag->next) || 491 skb_headroom(frag) < hlen) 492 goto slow_path; 493 494 /* Partially cloned skb? */ 495 if (skb_shared(frag)) 496 goto slow_path; 497 498 BUG_ON(frag->sk); 499 if (skb->sk) { 500 sock_hold(skb->sk); 501 frag->sk = skb->sk; 502 frag->destructor = sock_wfree; 503 truesizes += frag->truesize; 504 } 505 } 506 507 /* Everything is OK. Generate! */ 508 509 err = 0; 510 offset = 0; 511 frag = skb_shinfo(skb)->frag_list; 512 skb_shinfo(skb)->frag_list = NULL; 513 skb->data_len = first_len - skb_headlen(skb); 514 skb->truesize -= truesizes; 515 skb->len = first_len; 516 iph->tot_len = htons(first_len); 517 iph->frag_off = htons(IP_MF); 518 ip_send_check(iph); 519 520 for (;;) { 521 /* Prepare header of the next frame, 522 * before previous one went down. */ 523 if (frag) { 524 frag->ip_summed = CHECKSUM_NONE; 525 skb_reset_transport_header(frag); 526 __skb_push(frag, hlen); 527 skb_reset_network_header(frag); 528 memcpy(skb_network_header(frag), iph, hlen); 529 iph = ip_hdr(frag); 530 iph->tot_len = htons(frag->len); 531 ip_copy_metadata(frag, skb); 532 if (offset == 0) 533 ip_options_fragment(frag); 534 offset += skb->len - hlen; 535 iph->frag_off = htons(offset>>3); 536 if (frag->next != NULL) 537 iph->frag_off |= htons(IP_MF); 538 /* Ready, complete checksum */ 539 ip_send_check(iph); 540 } 541 542 err = output(skb); 543 544 if (!err) 545 IP_INC_STATS(dev_net(dev), IPSTATS_MIB_FRAGCREATES); 546 if (err || !frag) 547 break; 548 549 skb = frag; 550 frag = skb->next; 551 skb->next = NULL; 552 } 553 554 if (err == 0) { 555 IP_INC_STATS(dev_net(dev), IPSTATS_MIB_FRAGOKS); 556 return 0; 557 } 558 559 while (frag) { 560 skb = frag->next; 561 kfree_skb(frag); 562 frag = skb; 563 } 564 IP_INC_STATS(dev_net(dev), IPSTATS_MIB_FRAGFAILS); 565 return err; 566 } 567 568 slow_path: 569 left = skb->len - hlen; /* Space per frame */ 570 ptr = raw + hlen; /* Where to start from */ 571 572 /* for bridged IP traffic encapsulated inside f.e. a vlan header, 573 * we need to make room for the encapsulating header 574 */ 575 pad = nf_bridge_pad(skb); 576 ll_rs = LL_RESERVED_SPACE_EXTRA(rt->u.dst.dev, pad); 577 mtu -= pad; 578 579 /* 580 * Fragment the datagram. 581 */ 582 583 offset = (ntohs(iph->frag_off) & IP_OFFSET) << 3; 584 not_last_frag = iph->frag_off & htons(IP_MF); 585 586 /* 587 * Keep copying data until we run out. 588 */ 589 590 while (left > 0) { 591 len = left; 592 /* IF: it doesn't fit, use 'mtu' - the data space left */ 593 if (len > mtu) 594 len = mtu; 595 /* IF: we are not sending upto and including the packet end 596 then align the next start on an eight byte boundary */ 597 if (len < left) { 598 len &= ~7; 599 } 600 /* 601 * Allocate buffer. 602 */ 603 604 if ((skb2 = alloc_skb(len+hlen+ll_rs, GFP_ATOMIC)) == NULL) { 605 NETDEBUG(KERN_INFO "IP: frag: no memory for new fragment!\n"); 606 err = -ENOMEM; 607 goto fail; 608 } 609 610 /* 611 * Set up data on packet 612 */ 613 614 ip_copy_metadata(skb2, skb); 615 skb_reserve(skb2, ll_rs); 616 skb_put(skb2, len + hlen); 617 skb_reset_network_header(skb2); 618 skb2->transport_header = skb2->network_header + hlen; 619 620 /* 621 * Charge the memory for the fragment to any owner 622 * it might possess 623 */ 624 625 if (skb->sk) 626 skb_set_owner_w(skb2, skb->sk); 627 628 /* 629 * Copy the packet header into the new buffer. 630 */ 631 632 skb_copy_from_linear_data(skb, skb_network_header(skb2), hlen); 633 634 /* 635 * Copy a block of the IP datagram. 636 */ 637 if (skb_copy_bits(skb, ptr, skb_transport_header(skb2), len)) 638 BUG(); 639 left -= len; 640 641 /* 642 * Fill in the new header fields. 643 */ 644 iph = ip_hdr(skb2); 645 iph->frag_off = htons((offset >> 3)); 646 647 /* ANK: dirty, but effective trick. Upgrade options only if 648 * the segment to be fragmented was THE FIRST (otherwise, 649 * options are already fixed) and make it ONCE 650 * on the initial skb, so that all the following fragments 651 * will inherit fixed options. 652 */ 653 if (offset == 0) 654 ip_options_fragment(skb); 655 656 /* 657 * Added AC : If we are fragmenting a fragment that's not the 658 * last fragment then keep MF on each bit 659 */ 660 if (left > 0 || not_last_frag) 661 iph->frag_off |= htons(IP_MF); 662 ptr += len; 663 offset += len; 664 665 /* 666 * Put this fragment into the sending queue. 667 */ 668 iph->tot_len = htons(len + hlen); 669 670 ip_send_check(iph); 671 672 err = output(skb2); 673 if (err) 674 goto fail; 675 676 IP_INC_STATS(dev_net(dev), IPSTATS_MIB_FRAGCREATES); 677 } 678 kfree_skb(skb); 679 IP_INC_STATS(dev_net(dev), IPSTATS_MIB_FRAGOKS); 680 return err; 681 682 fail: 683 kfree_skb(skb); 684 IP_INC_STATS(dev_net(dev), IPSTATS_MIB_FRAGFAILS); 685 return err; 686 } 687 688 EXPORT_SYMBOL(ip_fragment); 689 690 int 691 ip_generic_getfrag(void *from, char *to, int offset, int len, int odd, struct sk_buff *skb) 692 { 693 struct iovec *iov = from; 694 695 if (skb->ip_summed == CHECKSUM_PARTIAL) { 696 if (memcpy_fromiovecend(to, iov, offset, len) < 0) 697 return -EFAULT; 698 } else { 699 __wsum csum = 0; 700 if (csum_partial_copy_fromiovecend(to, iov, offset, len, &csum) < 0) 701 return -EFAULT; 702 skb->csum = csum_block_add(skb->csum, csum, odd); 703 } 704 return 0; 705 } 706 707 static inline __wsum 708 csum_page(struct page *page, int offset, int copy) 709 { 710 char *kaddr; 711 __wsum csum; 712 kaddr = kmap(page); 713 csum = csum_partial(kaddr + offset, copy, 0); 714 kunmap(page); 715 return csum; 716 } 717 718 static inline int ip_ufo_append_data(struct sock *sk, 719 int getfrag(void *from, char *to, int offset, int len, 720 int odd, struct sk_buff *skb), 721 void *from, int length, int hh_len, int fragheaderlen, 722 int transhdrlen, int mtu,unsigned int flags) 723 { 724 struct sk_buff *skb; 725 int err; 726 727 /* There is support for UDP fragmentation offload by network 728 * device, so create one single skb packet containing complete 729 * udp datagram 730 */ 731 if ((skb = skb_peek_tail(&sk->sk_write_queue)) == NULL) { 732 skb = sock_alloc_send_skb(sk, 733 hh_len + fragheaderlen + transhdrlen + 20, 734 (flags & MSG_DONTWAIT), &err); 735 736 if (skb == NULL) 737 return err; 738 739 /* reserve space for Hardware header */ 740 skb_reserve(skb, hh_len); 741 742 /* create space for UDP/IP header */ 743 skb_put(skb,fragheaderlen + transhdrlen); 744 745 /* initialize network header pointer */ 746 skb_reset_network_header(skb); 747 748 /* initialize protocol header pointer */ 749 skb->transport_header = skb->network_header + fragheaderlen; 750 751 skb->ip_summed = CHECKSUM_PARTIAL; 752 skb->csum = 0; 753 sk->sk_sndmsg_off = 0; 754 755 /* specify the length of each IP datagram fragment */ 756 skb_shinfo(skb)->gso_size = mtu - fragheaderlen; 757 skb_shinfo(skb)->gso_type = SKB_GSO_UDP; 758 __skb_queue_tail(&sk->sk_write_queue, skb); 759 } 760 761 return skb_append_datato_frags(sk, skb, getfrag, from, 762 (length - transhdrlen)); 763 } 764 765 /* 766 * ip_append_data() and ip_append_page() can make one large IP datagram 767 * from many pieces of data. Each pieces will be holded on the socket 768 * until ip_push_pending_frames() is called. Each piece can be a page 769 * or non-page data. 770 * 771 * Not only UDP, other transport protocols - e.g. raw sockets - can use 772 * this interface potentially. 773 * 774 * LATER: length must be adjusted by pad at tail, when it is required. 775 */ 776 int ip_append_data(struct sock *sk, 777 int getfrag(void *from, char *to, int offset, int len, 778 int odd, struct sk_buff *skb), 779 void *from, int length, int transhdrlen, 780 struct ipcm_cookie *ipc, struct rtable *rt, 781 unsigned int flags) 782 { 783 struct inet_sock *inet = inet_sk(sk); 784 struct sk_buff *skb; 785 786 struct ip_options *opt = NULL; 787 int hh_len; 788 int exthdrlen; 789 int mtu; 790 int copy; 791 int err; 792 int offset = 0; 793 unsigned int maxfraglen, fragheaderlen; 794 int csummode = CHECKSUM_NONE; 795 796 if (flags&MSG_PROBE) 797 return 0; 798 799 if (skb_queue_empty(&sk->sk_write_queue)) { 800 /* 801 * setup for corking. 802 */ 803 opt = ipc->opt; 804 if (opt) { 805 if (inet->cork.opt == NULL) { 806 inet->cork.opt = kmalloc(sizeof(struct ip_options) + 40, sk->sk_allocation); 807 if (unlikely(inet->cork.opt == NULL)) 808 return -ENOBUFS; 809 } 810 memcpy(inet->cork.opt, opt, sizeof(struct ip_options)+opt->optlen); 811 inet->cork.flags |= IPCORK_OPT; 812 inet->cork.addr = ipc->addr; 813 } 814 dst_hold(&rt->u.dst); 815 inet->cork.fragsize = mtu = inet->pmtudisc == IP_PMTUDISC_PROBE ? 816 rt->u.dst.dev->mtu : 817 dst_mtu(rt->u.dst.path); 818 inet->cork.dst = &rt->u.dst; 819 inet->cork.length = 0; 820 sk->sk_sndmsg_page = NULL; 821 sk->sk_sndmsg_off = 0; 822 if ((exthdrlen = rt->u.dst.header_len) != 0) { 823 length += exthdrlen; 824 transhdrlen += exthdrlen; 825 } 826 } else { 827 rt = (struct rtable *)inet->cork.dst; 828 if (inet->cork.flags & IPCORK_OPT) 829 opt = inet->cork.opt; 830 831 transhdrlen = 0; 832 exthdrlen = 0; 833 mtu = inet->cork.fragsize; 834 } 835 hh_len = LL_RESERVED_SPACE(rt->u.dst.dev); 836 837 fragheaderlen = sizeof(struct iphdr) + (opt ? opt->optlen : 0); 838 maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen; 839 840 if (inet->cork.length + length > 0xFFFF - fragheaderlen) { 841 ip_local_error(sk, EMSGSIZE, rt->rt_dst, inet->dport, mtu-exthdrlen); 842 return -EMSGSIZE; 843 } 844 845 /* 846 * transhdrlen > 0 means that this is the first fragment and we wish 847 * it won't be fragmented in the future. 848 */ 849 if (transhdrlen && 850 length + fragheaderlen <= mtu && 851 rt->u.dst.dev->features & NETIF_F_V4_CSUM && 852 !exthdrlen) 853 csummode = CHECKSUM_PARTIAL; 854 855 inet->cork.length += length; 856 if (((length> mtu) || !skb_queue_empty(&sk->sk_write_queue)) && 857 (sk->sk_protocol == IPPROTO_UDP) && 858 (rt->u.dst.dev->features & NETIF_F_UFO)) { 859 err = ip_ufo_append_data(sk, getfrag, from, length, hh_len, 860 fragheaderlen, transhdrlen, mtu, 861 flags); 862 if (err) 863 goto error; 864 return 0; 865 } 866 867 /* So, what's going on in the loop below? 868 * 869 * We use calculated fragment length to generate chained skb, 870 * each of segments is IP fragment ready for sending to network after 871 * adding appropriate IP header. 872 */ 873 874 if ((skb = skb_peek_tail(&sk->sk_write_queue)) == NULL) 875 goto alloc_new_skb; 876 877 while (length > 0) { 878 /* Check if the remaining data fits into current packet. */ 879 copy = mtu - skb->len; 880 if (copy < length) 881 copy = maxfraglen - skb->len; 882 if (copy <= 0) { 883 char *data; 884 unsigned int datalen; 885 unsigned int fraglen; 886 unsigned int fraggap; 887 unsigned int alloclen; 888 struct sk_buff *skb_prev; 889 alloc_new_skb: 890 skb_prev = skb; 891 if (skb_prev) 892 fraggap = skb_prev->len - maxfraglen; 893 else 894 fraggap = 0; 895 896 /* 897 * If remaining data exceeds the mtu, 898 * we know we need more fragment(s). 899 */ 900 datalen = length + fraggap; 901 if (datalen > mtu - fragheaderlen) 902 datalen = maxfraglen - fragheaderlen; 903 fraglen = datalen + fragheaderlen; 904 905 if ((flags & MSG_MORE) && 906 !(rt->u.dst.dev->features&NETIF_F_SG)) 907 alloclen = mtu; 908 else 909 alloclen = datalen + fragheaderlen; 910 911 /* The last fragment gets additional space at tail. 912 * Note, with MSG_MORE we overallocate on fragments, 913 * because we have no idea what fragment will be 914 * the last. 915 */ 916 if (datalen == length + fraggap) 917 alloclen += rt->u.dst.trailer_len; 918 919 if (transhdrlen) { 920 skb = sock_alloc_send_skb(sk, 921 alloclen + hh_len + 15, 922 (flags & MSG_DONTWAIT), &err); 923 } else { 924 skb = NULL; 925 if (atomic_read(&sk->sk_wmem_alloc) <= 926 2 * sk->sk_sndbuf) 927 skb = sock_wmalloc(sk, 928 alloclen + hh_len + 15, 1, 929 sk->sk_allocation); 930 if (unlikely(skb == NULL)) 931 err = -ENOBUFS; 932 } 933 if (skb == NULL) 934 goto error; 935 936 /* 937 * Fill in the control structures 938 */ 939 skb->ip_summed = csummode; 940 skb->csum = 0; 941 skb_reserve(skb, hh_len); 942 943 /* 944 * Find where to start putting bytes. 945 */ 946 data = skb_put(skb, fraglen); 947 skb_set_network_header(skb, exthdrlen); 948 skb->transport_header = (skb->network_header + 949 fragheaderlen); 950 data += fragheaderlen; 951 952 if (fraggap) { 953 skb->csum = skb_copy_and_csum_bits( 954 skb_prev, maxfraglen, 955 data + transhdrlen, fraggap, 0); 956 skb_prev->csum = csum_sub(skb_prev->csum, 957 skb->csum); 958 data += fraggap; 959 pskb_trim_unique(skb_prev, maxfraglen); 960 } 961 962 copy = datalen - transhdrlen - fraggap; 963 if (copy > 0 && getfrag(from, data + transhdrlen, offset, copy, fraggap, skb) < 0) { 964 err = -EFAULT; 965 kfree_skb(skb); 966 goto error; 967 } 968 969 offset += copy; 970 length -= datalen - fraggap; 971 transhdrlen = 0; 972 exthdrlen = 0; 973 csummode = CHECKSUM_NONE; 974 975 /* 976 * Put the packet on the pending queue. 977 */ 978 __skb_queue_tail(&sk->sk_write_queue, skb); 979 continue; 980 } 981 982 if (copy > length) 983 copy = length; 984 985 if (!(rt->u.dst.dev->features&NETIF_F_SG)) { 986 unsigned int off; 987 988 off = skb->len; 989 if (getfrag(from, skb_put(skb, copy), 990 offset, copy, off, skb) < 0) { 991 __skb_trim(skb, off); 992 err = -EFAULT; 993 goto error; 994 } 995 } else { 996 int i = skb_shinfo(skb)->nr_frags; 997 skb_frag_t *frag = &skb_shinfo(skb)->frags[i-1]; 998 struct page *page = sk->sk_sndmsg_page; 999 int off = sk->sk_sndmsg_off; 1000 unsigned int left; 1001 1002 if (page && (left = PAGE_SIZE - off) > 0) { 1003 if (copy >= left) 1004 copy = left; 1005 if (page != frag->page) { 1006 if (i == MAX_SKB_FRAGS) { 1007 err = -EMSGSIZE; 1008 goto error; 1009 } 1010 get_page(page); 1011 skb_fill_page_desc(skb, i, page, sk->sk_sndmsg_off, 0); 1012 frag = &skb_shinfo(skb)->frags[i]; 1013 } 1014 } else if (i < MAX_SKB_FRAGS) { 1015 if (copy > PAGE_SIZE) 1016 copy = PAGE_SIZE; 1017 page = alloc_pages(sk->sk_allocation, 0); 1018 if (page == NULL) { 1019 err = -ENOMEM; 1020 goto error; 1021 } 1022 sk->sk_sndmsg_page = page; 1023 sk->sk_sndmsg_off = 0; 1024 1025 skb_fill_page_desc(skb, i, page, 0, 0); 1026 frag = &skb_shinfo(skb)->frags[i]; 1027 } else { 1028 err = -EMSGSIZE; 1029 goto error; 1030 } 1031 if (getfrag(from, page_address(frag->page)+frag->page_offset+frag->size, offset, copy, skb->len, skb) < 0) { 1032 err = -EFAULT; 1033 goto error; 1034 } 1035 sk->sk_sndmsg_off += copy; 1036 frag->size += copy; 1037 skb->len += copy; 1038 skb->data_len += copy; 1039 skb->truesize += copy; 1040 atomic_add(copy, &sk->sk_wmem_alloc); 1041 } 1042 offset += copy; 1043 length -= copy; 1044 } 1045 1046 return 0; 1047 1048 error: 1049 inet->cork.length -= length; 1050 IP_INC_STATS(sock_net(sk), IPSTATS_MIB_OUTDISCARDS); 1051 return err; 1052 } 1053 1054 ssize_t ip_append_page(struct sock *sk, struct page *page, 1055 int offset, size_t size, int flags) 1056 { 1057 struct inet_sock *inet = inet_sk(sk); 1058 struct sk_buff *skb; 1059 struct rtable *rt; 1060 struct ip_options *opt = NULL; 1061 int hh_len; 1062 int mtu; 1063 int len; 1064 int err; 1065 unsigned int maxfraglen, fragheaderlen, fraggap; 1066 1067 if (inet->hdrincl) 1068 return -EPERM; 1069 1070 if (flags&MSG_PROBE) 1071 return 0; 1072 1073 if (skb_queue_empty(&sk->sk_write_queue)) 1074 return -EINVAL; 1075 1076 rt = (struct rtable *)inet->cork.dst; 1077 if (inet->cork.flags & IPCORK_OPT) 1078 opt = inet->cork.opt; 1079 1080 if (!(rt->u.dst.dev->features&NETIF_F_SG)) 1081 return -EOPNOTSUPP; 1082 1083 hh_len = LL_RESERVED_SPACE(rt->u.dst.dev); 1084 mtu = inet->cork.fragsize; 1085 1086 fragheaderlen = sizeof(struct iphdr) + (opt ? opt->optlen : 0); 1087 maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen; 1088 1089 if (inet->cork.length + size > 0xFFFF - fragheaderlen) { 1090 ip_local_error(sk, EMSGSIZE, rt->rt_dst, inet->dport, mtu); 1091 return -EMSGSIZE; 1092 } 1093 1094 if ((skb = skb_peek_tail(&sk->sk_write_queue)) == NULL) 1095 return -EINVAL; 1096 1097 inet->cork.length += size; 1098 if ((sk->sk_protocol == IPPROTO_UDP) && 1099 (rt->u.dst.dev->features & NETIF_F_UFO)) { 1100 skb_shinfo(skb)->gso_size = mtu - fragheaderlen; 1101 skb_shinfo(skb)->gso_type = SKB_GSO_UDP; 1102 } 1103 1104 1105 while (size > 0) { 1106 int i; 1107 1108 if (skb_is_gso(skb)) 1109 len = size; 1110 else { 1111 1112 /* Check if the remaining data fits into current packet. */ 1113 len = mtu - skb->len; 1114 if (len < size) 1115 len = maxfraglen - skb->len; 1116 } 1117 if (len <= 0) { 1118 struct sk_buff *skb_prev; 1119 int alloclen; 1120 1121 skb_prev = skb; 1122 fraggap = skb_prev->len - maxfraglen; 1123 1124 alloclen = fragheaderlen + hh_len + fraggap + 15; 1125 skb = sock_wmalloc(sk, alloclen, 1, sk->sk_allocation); 1126 if (unlikely(!skb)) { 1127 err = -ENOBUFS; 1128 goto error; 1129 } 1130 1131 /* 1132 * Fill in the control structures 1133 */ 1134 skb->ip_summed = CHECKSUM_NONE; 1135 skb->csum = 0; 1136 skb_reserve(skb, hh_len); 1137 1138 /* 1139 * Find where to start putting bytes. 1140 */ 1141 skb_put(skb, fragheaderlen + fraggap); 1142 skb_reset_network_header(skb); 1143 skb->transport_header = (skb->network_header + 1144 fragheaderlen); 1145 if (fraggap) { 1146 skb->csum = skb_copy_and_csum_bits(skb_prev, 1147 maxfraglen, 1148 skb_transport_header(skb), 1149 fraggap, 0); 1150 skb_prev->csum = csum_sub(skb_prev->csum, 1151 skb->csum); 1152 pskb_trim_unique(skb_prev, maxfraglen); 1153 } 1154 1155 /* 1156 * Put the packet on the pending queue. 1157 */ 1158 __skb_queue_tail(&sk->sk_write_queue, skb); 1159 continue; 1160 } 1161 1162 i = skb_shinfo(skb)->nr_frags; 1163 if (len > size) 1164 len = size; 1165 if (skb_can_coalesce(skb, i, page, offset)) { 1166 skb_shinfo(skb)->frags[i-1].size += len; 1167 } else if (i < MAX_SKB_FRAGS) { 1168 get_page(page); 1169 skb_fill_page_desc(skb, i, page, offset, len); 1170 } else { 1171 err = -EMSGSIZE; 1172 goto error; 1173 } 1174 1175 if (skb->ip_summed == CHECKSUM_NONE) { 1176 __wsum csum; 1177 csum = csum_page(page, offset, len); 1178 skb->csum = csum_block_add(skb->csum, csum, skb->len); 1179 } 1180 1181 skb->len += len; 1182 skb->data_len += len; 1183 skb->truesize += len; 1184 atomic_add(len, &sk->sk_wmem_alloc); 1185 offset += len; 1186 size -= len; 1187 } 1188 return 0; 1189 1190 error: 1191 inet->cork.length -= size; 1192 IP_INC_STATS(sock_net(sk), IPSTATS_MIB_OUTDISCARDS); 1193 return err; 1194 } 1195 1196 static void ip_cork_release(struct inet_sock *inet) 1197 { 1198 inet->cork.flags &= ~IPCORK_OPT; 1199 kfree(inet->cork.opt); 1200 inet->cork.opt = NULL; 1201 dst_release(inet->cork.dst); 1202 inet->cork.dst = NULL; 1203 } 1204 1205 /* 1206 * Combined all pending IP fragments on the socket as one IP datagram 1207 * and push them out. 1208 */ 1209 int ip_push_pending_frames(struct sock *sk) 1210 { 1211 struct sk_buff *skb, *tmp_skb; 1212 struct sk_buff **tail_skb; 1213 struct inet_sock *inet = inet_sk(sk); 1214 struct net *net = sock_net(sk); 1215 struct ip_options *opt = NULL; 1216 struct rtable *rt = (struct rtable *)inet->cork.dst; 1217 struct iphdr *iph; 1218 __be16 df = 0; 1219 __u8 ttl; 1220 int err = 0; 1221 1222 if ((skb = __skb_dequeue(&sk->sk_write_queue)) == NULL) 1223 goto out; 1224 tail_skb = &(skb_shinfo(skb)->frag_list); 1225 1226 /* move skb->data to ip header from ext header */ 1227 if (skb->data < skb_network_header(skb)) 1228 __skb_pull(skb, skb_network_offset(skb)); 1229 while ((tmp_skb = __skb_dequeue(&sk->sk_write_queue)) != NULL) { 1230 __skb_pull(tmp_skb, skb_network_header_len(skb)); 1231 *tail_skb = tmp_skb; 1232 tail_skb = &(tmp_skb->next); 1233 skb->len += tmp_skb->len; 1234 skb->data_len += tmp_skb->len; 1235 skb->truesize += tmp_skb->truesize; 1236 __sock_put(tmp_skb->sk); 1237 tmp_skb->destructor = NULL; 1238 tmp_skb->sk = NULL; 1239 } 1240 1241 /* Unless user demanded real pmtu discovery (IP_PMTUDISC_DO), we allow 1242 * to fragment the frame generated here. No matter, what transforms 1243 * how transforms change size of the packet, it will come out. 1244 */ 1245 if (inet->pmtudisc < IP_PMTUDISC_DO) 1246 skb->local_df = 1; 1247 1248 /* DF bit is set when we want to see DF on outgoing frames. 1249 * If local_df is set too, we still allow to fragment this frame 1250 * locally. */ 1251 if (inet->pmtudisc >= IP_PMTUDISC_DO || 1252 (skb->len <= dst_mtu(&rt->u.dst) && 1253 ip_dont_fragment(sk, &rt->u.dst))) 1254 df = htons(IP_DF); 1255 1256 if (inet->cork.flags & IPCORK_OPT) 1257 opt = inet->cork.opt; 1258 1259 if (rt->rt_type == RTN_MULTICAST) 1260 ttl = inet->mc_ttl; 1261 else 1262 ttl = ip_select_ttl(inet, &rt->u.dst); 1263 1264 iph = (struct iphdr *)skb->data; 1265 iph->version = 4; 1266 iph->ihl = 5; 1267 if (opt) { 1268 iph->ihl += opt->optlen>>2; 1269 ip_options_build(skb, opt, inet->cork.addr, rt, 0); 1270 } 1271 iph->tos = inet->tos; 1272 iph->frag_off = df; 1273 ip_select_ident(iph, &rt->u.dst, sk); 1274 iph->ttl = ttl; 1275 iph->protocol = sk->sk_protocol; 1276 iph->saddr = rt->rt_src; 1277 iph->daddr = rt->rt_dst; 1278 1279 skb->priority = sk->sk_priority; 1280 skb->mark = sk->sk_mark; 1281 skb->dst = dst_clone(&rt->u.dst); 1282 1283 if (iph->protocol == IPPROTO_ICMP) 1284 icmp_out_count(net, ((struct icmphdr *) 1285 skb_transport_header(skb))->type); 1286 1287 /* Netfilter gets whole the not fragmented skb. */ 1288 err = ip_local_out(skb); 1289 if (err) { 1290 if (err > 0) 1291 err = inet->recverr ? net_xmit_errno(err) : 0; 1292 if (err) 1293 goto error; 1294 } 1295 1296 out: 1297 ip_cork_release(inet); 1298 return err; 1299 1300 error: 1301 IP_INC_STATS(net, IPSTATS_MIB_OUTDISCARDS); 1302 goto out; 1303 } 1304 1305 /* 1306 * Throw away all pending data on the socket. 1307 */ 1308 void ip_flush_pending_frames(struct sock *sk) 1309 { 1310 struct sk_buff *skb; 1311 1312 while ((skb = __skb_dequeue_tail(&sk->sk_write_queue)) != NULL) 1313 kfree_skb(skb); 1314 1315 ip_cork_release(inet_sk(sk)); 1316 } 1317 1318 1319 /* 1320 * Fetch data from kernel space and fill in checksum if needed. 1321 */ 1322 static int ip_reply_glue_bits(void *dptr, char *to, int offset, 1323 int len, int odd, struct sk_buff *skb) 1324 { 1325 __wsum csum; 1326 1327 csum = csum_partial_copy_nocheck(dptr+offset, to, len, 0); 1328 skb->csum = csum_block_add(skb->csum, csum, odd); 1329 return 0; 1330 } 1331 1332 /* 1333 * Generic function to send a packet as reply to another packet. 1334 * Used to send TCP resets so far. ICMP should use this function too. 1335 * 1336 * Should run single threaded per socket because it uses the sock 1337 * structure to pass arguments. 1338 */ 1339 void ip_send_reply(struct sock *sk, struct sk_buff *skb, struct ip_reply_arg *arg, 1340 unsigned int len) 1341 { 1342 struct inet_sock *inet = inet_sk(sk); 1343 struct { 1344 struct ip_options opt; 1345 char data[40]; 1346 } replyopts; 1347 struct ipcm_cookie ipc; 1348 __be32 daddr; 1349 struct rtable *rt = skb->rtable; 1350 1351 if (ip_options_echo(&replyopts.opt, skb)) 1352 return; 1353 1354 daddr = ipc.addr = rt->rt_src; 1355 ipc.opt = NULL; 1356 1357 if (replyopts.opt.optlen) { 1358 ipc.opt = &replyopts.opt; 1359 1360 if (ipc.opt->srr) 1361 daddr = replyopts.opt.faddr; 1362 } 1363 1364 { 1365 struct flowi fl = { .oif = arg->bound_dev_if, 1366 .nl_u = { .ip4_u = 1367 { .daddr = daddr, 1368 .saddr = rt->rt_spec_dst, 1369 .tos = RT_TOS(ip_hdr(skb)->tos) } }, 1370 /* Not quite clean, but right. */ 1371 .uli_u = { .ports = 1372 { .sport = tcp_hdr(skb)->dest, 1373 .dport = tcp_hdr(skb)->source } }, 1374 .proto = sk->sk_protocol }; 1375 security_skb_classify_flow(skb, &fl); 1376 if (ip_route_output_key(sock_net(sk), &rt, &fl)) 1377 return; 1378 } 1379 1380 /* And let IP do all the hard work. 1381 1382 This chunk is not reenterable, hence spinlock. 1383 Note that it uses the fact, that this function is called 1384 with locally disabled BH and that sk cannot be already spinlocked. 1385 */ 1386 bh_lock_sock(sk); 1387 inet->tos = ip_hdr(skb)->tos; 1388 sk->sk_priority = skb->priority; 1389 sk->sk_protocol = ip_hdr(skb)->protocol; 1390 sk->sk_bound_dev_if = arg->bound_dev_if; 1391 ip_append_data(sk, ip_reply_glue_bits, arg->iov->iov_base, len, 0, 1392 &ipc, rt, MSG_DONTWAIT); 1393 if ((skb = skb_peek(&sk->sk_write_queue)) != NULL) { 1394 if (arg->csumoffset >= 0) 1395 *((__sum16 *)skb_transport_header(skb) + 1396 arg->csumoffset) = csum_fold(csum_add(skb->csum, 1397 arg->csum)); 1398 skb->ip_summed = CHECKSUM_NONE; 1399 ip_push_pending_frames(sk); 1400 } 1401 1402 bh_unlock_sock(sk); 1403 1404 ip_rt_put(rt); 1405 } 1406 1407 void __init ip_init(void) 1408 { 1409 ip_rt_init(); 1410 inet_initpeers(); 1411 1412 #if defined(CONFIG_IP_MULTICAST) && defined(CONFIG_PROC_FS) 1413 igmp_mc_proc_init(); 1414 #endif 1415 } 1416 1417 EXPORT_SYMBOL(ip_generic_getfrag); 1418 EXPORT_SYMBOL(ip_queue_xmit); 1419 EXPORT_SYMBOL(ip_send_check); 1420