1 /* 2 * IPv6 output functions 3 * Linux INET6 implementation 4 * 5 * Authors: 6 * Pedro Roque <roque@di.fc.ul.pt> 7 * 8 * $Id: ip6_output.c,v 1.34 2002/02/01 22:01:04 davem Exp $ 9 * 10 * Based on linux/net/ipv4/ip_output.c 11 * 12 * This program is free software; you can redistribute it and/or 13 * modify it under the terms of the GNU General Public License 14 * as published by the Free Software Foundation; either version 15 * 2 of the License, or (at your option) any later version. 16 * 17 * Changes: 18 * A.N.Kuznetsov : airthmetics in fragmentation. 19 * extension headers are implemented. 20 * route changes now work. 21 * ip6_forward does not confuse sniffers. 22 * etc. 23 * 24 * H. von Brand : Added missing #include <linux/string.h> 25 * Imran Patel : frag id should be in NBO 26 * Kazunori MIYAZAWA @USAGI 27 * : add ip6_append_data and related functions 28 * for datagram xmit 29 */ 30 31 #include <linux/errno.h> 32 #include <linux/types.h> 33 #include <linux/string.h> 34 #include <linux/socket.h> 35 #include <linux/net.h> 36 #include <linux/netdevice.h> 37 #include <linux/if_arp.h> 38 #include <linux/in6.h> 39 #include <linux/tcp.h> 40 #include <linux/route.h> 41 #include <linux/module.h> 42 43 #include <linux/netfilter.h> 44 #include <linux/netfilter_ipv6.h> 45 46 #include <net/sock.h> 47 #include <net/snmp.h> 48 49 #include <net/ipv6.h> 50 #include <net/ndisc.h> 51 #include <net/protocol.h> 52 #include <net/ip6_route.h> 53 #include <net/addrconf.h> 54 #include <net/rawv6.h> 55 #include <net/icmp.h> 56 #include <net/xfrm.h> 57 #include <net/checksum.h> 58 59 static int ip6_fragment(struct sk_buff *skb, int (*output)(struct sk_buff *)); 60 61 static __inline__ void ipv6_select_ident(struct sk_buff *skb, struct frag_hdr *fhdr) 62 { 63 static u32 ipv6_fragmentation_id = 1; 64 static DEFINE_SPINLOCK(ip6_id_lock); 65 66 spin_lock_bh(&ip6_id_lock); 67 fhdr->identification = htonl(ipv6_fragmentation_id); 68 if (++ipv6_fragmentation_id == 0) 69 ipv6_fragmentation_id = 1; 70 spin_unlock_bh(&ip6_id_lock); 71 } 72 73 static inline int ip6_output_finish(struct sk_buff *skb) 74 { 75 struct dst_entry *dst = skb->dst; 76 77 if (dst->hh) 78 return neigh_hh_output(dst->hh, skb); 79 else if (dst->neighbour) 80 return dst->neighbour->output(skb); 81 82 IP6_INC_STATS_BH(ip6_dst_idev(dst), IPSTATS_MIB_OUTNOROUTES); 83 kfree_skb(skb); 84 return -EINVAL; 85 86 } 87 88 /* dev_loopback_xmit for use with netfilter. */ 89 static int ip6_dev_loopback_xmit(struct sk_buff *newskb) 90 { 91 skb_reset_mac_header(newskb); 92 __skb_pull(newskb, skb_network_offset(newskb)); 93 newskb->pkt_type = PACKET_LOOPBACK; 94 newskb->ip_summed = CHECKSUM_UNNECESSARY; 95 BUG_TRAP(newskb->dst); 96 97 netif_rx(newskb); 98 return 0; 99 } 100 101 102 static int ip6_output2(struct sk_buff *skb) 103 { 104 struct dst_entry *dst = skb->dst; 105 struct net_device *dev = dst->dev; 106 107 skb->protocol = htons(ETH_P_IPV6); 108 skb->dev = dev; 109 110 if (ipv6_addr_is_multicast(&ipv6_hdr(skb)->daddr)) { 111 struct ipv6_pinfo* np = skb->sk ? inet6_sk(skb->sk) : NULL; 112 struct inet6_dev *idev = ip6_dst_idev(skb->dst); 113 114 if (!(dev->flags & IFF_LOOPBACK) && (!np || np->mc_loop) && 115 ipv6_chk_mcast_addr(dev, &ipv6_hdr(skb)->daddr, 116 &ipv6_hdr(skb)->saddr)) { 117 struct sk_buff *newskb = skb_clone(skb, GFP_ATOMIC); 118 119 /* Do not check for IFF_ALLMULTI; multicast routing 120 is not supported in any case. 121 */ 122 if (newskb) 123 NF_HOOK(PF_INET6, NF_IP6_POST_ROUTING, newskb, NULL, 124 newskb->dev, 125 ip6_dev_loopback_xmit); 126 127 if (ipv6_hdr(skb)->hop_limit == 0) { 128 IP6_INC_STATS(idev, IPSTATS_MIB_OUTDISCARDS); 129 kfree_skb(skb); 130 return 0; 131 } 132 } 133 134 IP6_INC_STATS(idev, IPSTATS_MIB_OUTMCASTPKTS); 135 } 136 137 return NF_HOOK(PF_INET6, NF_IP6_POST_ROUTING, skb,NULL, skb->dev,ip6_output_finish); 138 } 139 140 static inline int ip6_skb_dst_mtu(struct sk_buff *skb) 141 { 142 struct ipv6_pinfo *np = skb->sk ? inet6_sk(skb->sk) : NULL; 143 144 return (np && np->pmtudisc == IPV6_PMTUDISC_PROBE) ? 145 skb->dst->dev->mtu : dst_mtu(skb->dst); 146 } 147 148 int ip6_output(struct sk_buff *skb) 149 { 150 if ((skb->len > ip6_skb_dst_mtu(skb) && !skb_is_gso(skb)) || 151 dst_allfrag(skb->dst)) 152 return ip6_fragment(skb, ip6_output2); 153 else 154 return ip6_output2(skb); 155 } 156 157 /* 158 * xmit an sk_buff (used by TCP) 159 */ 160 161 int ip6_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl, 162 struct ipv6_txoptions *opt, int ipfragok) 163 { 164 struct ipv6_pinfo *np = inet6_sk(sk); 165 struct in6_addr *first_hop = &fl->fl6_dst; 166 struct dst_entry *dst = skb->dst; 167 struct ipv6hdr *hdr; 168 u8 proto = fl->proto; 169 int seg_len = skb->len; 170 int hlimit, tclass; 171 u32 mtu; 172 173 if (opt) { 174 int head_room; 175 176 /* First: exthdrs may take lots of space (~8K for now) 177 MAX_HEADER is not enough. 178 */ 179 head_room = opt->opt_nflen + opt->opt_flen; 180 seg_len += head_room; 181 head_room += sizeof(struct ipv6hdr) + LL_RESERVED_SPACE(dst->dev); 182 183 if (skb_headroom(skb) < head_room) { 184 struct sk_buff *skb2 = skb_realloc_headroom(skb, head_room); 185 if (skb2 == NULL) { 186 IP6_INC_STATS(ip6_dst_idev(skb->dst), 187 IPSTATS_MIB_OUTDISCARDS); 188 kfree_skb(skb); 189 return -ENOBUFS; 190 } 191 kfree_skb(skb); 192 skb = skb2; 193 if (sk) 194 skb_set_owner_w(skb, sk); 195 } 196 if (opt->opt_flen) 197 ipv6_push_frag_opts(skb, opt, &proto); 198 if (opt->opt_nflen) 199 ipv6_push_nfrag_opts(skb, opt, &proto, &first_hop); 200 } 201 202 skb_push(skb, sizeof(struct ipv6hdr)); 203 skb_reset_network_header(skb); 204 hdr = ipv6_hdr(skb); 205 206 /* 207 * Fill in the IPv6 header 208 */ 209 210 hlimit = -1; 211 if (np) 212 hlimit = np->hop_limit; 213 if (hlimit < 0) 214 hlimit = dst_metric(dst, RTAX_HOPLIMIT); 215 if (hlimit < 0) 216 hlimit = ipv6_get_hoplimit(dst->dev); 217 218 tclass = -1; 219 if (np) 220 tclass = np->tclass; 221 if (tclass < 0) 222 tclass = 0; 223 224 *(__be32 *)hdr = htonl(0x60000000 | (tclass << 20)) | fl->fl6_flowlabel; 225 226 hdr->payload_len = htons(seg_len); 227 hdr->nexthdr = proto; 228 hdr->hop_limit = hlimit; 229 230 ipv6_addr_copy(&hdr->saddr, &fl->fl6_src); 231 ipv6_addr_copy(&hdr->daddr, first_hop); 232 233 skb->priority = sk->sk_priority; 234 235 mtu = dst_mtu(dst); 236 if ((skb->len <= mtu) || ipfragok || skb_is_gso(skb)) { 237 IP6_INC_STATS(ip6_dst_idev(skb->dst), 238 IPSTATS_MIB_OUTREQUESTS); 239 return NF_HOOK(PF_INET6, NF_IP6_LOCAL_OUT, skb, NULL, dst->dev, 240 dst_output); 241 } 242 243 if (net_ratelimit()) 244 printk(KERN_DEBUG "IPv6: sending pkt_too_big to self\n"); 245 skb->dev = dst->dev; 246 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu, skb->dev); 247 IP6_INC_STATS(ip6_dst_idev(skb->dst), IPSTATS_MIB_FRAGFAILS); 248 kfree_skb(skb); 249 return -EMSGSIZE; 250 } 251 252 EXPORT_SYMBOL(ip6_xmit); 253 254 /* 255 * To avoid extra problems ND packets are send through this 256 * routine. It's code duplication but I really want to avoid 257 * extra checks since ipv6_build_header is used by TCP (which 258 * is for us performance critical) 259 */ 260 261 int ip6_nd_hdr(struct sock *sk, struct sk_buff *skb, struct net_device *dev, 262 struct in6_addr *saddr, struct in6_addr *daddr, 263 int proto, int len) 264 { 265 struct ipv6_pinfo *np = inet6_sk(sk); 266 struct ipv6hdr *hdr; 267 int totlen; 268 269 skb->protocol = htons(ETH_P_IPV6); 270 skb->dev = dev; 271 272 totlen = len + sizeof(struct ipv6hdr); 273 274 skb_reset_network_header(skb); 275 skb_put(skb, sizeof(struct ipv6hdr)); 276 hdr = ipv6_hdr(skb); 277 278 *(__be32*)hdr = htonl(0x60000000); 279 280 hdr->payload_len = htons(len); 281 hdr->nexthdr = proto; 282 hdr->hop_limit = np->hop_limit; 283 284 ipv6_addr_copy(&hdr->saddr, saddr); 285 ipv6_addr_copy(&hdr->daddr, daddr); 286 287 return 0; 288 } 289 290 static int ip6_call_ra_chain(struct sk_buff *skb, int sel) 291 { 292 struct ip6_ra_chain *ra; 293 struct sock *last = NULL; 294 295 read_lock(&ip6_ra_lock); 296 for (ra = ip6_ra_chain; ra; ra = ra->next) { 297 struct sock *sk = ra->sk; 298 if (sk && ra->sel == sel && 299 (!sk->sk_bound_dev_if || 300 sk->sk_bound_dev_if == skb->dev->ifindex)) { 301 if (last) { 302 struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC); 303 if (skb2) 304 rawv6_rcv(last, skb2); 305 } 306 last = sk; 307 } 308 } 309 310 if (last) { 311 rawv6_rcv(last, skb); 312 read_unlock(&ip6_ra_lock); 313 return 1; 314 } 315 read_unlock(&ip6_ra_lock); 316 return 0; 317 } 318 319 static int ip6_forward_proxy_check(struct sk_buff *skb) 320 { 321 struct ipv6hdr *hdr = ipv6_hdr(skb); 322 u8 nexthdr = hdr->nexthdr; 323 int offset; 324 325 if (ipv6_ext_hdr(nexthdr)) { 326 offset = ipv6_skip_exthdr(skb, sizeof(*hdr), &nexthdr); 327 if (offset < 0) 328 return 0; 329 } else 330 offset = sizeof(struct ipv6hdr); 331 332 if (nexthdr == IPPROTO_ICMPV6) { 333 struct icmp6hdr *icmp6; 334 335 if (!pskb_may_pull(skb, (skb_network_header(skb) + 336 offset + 1 - skb->data))) 337 return 0; 338 339 icmp6 = (struct icmp6hdr *)(skb_network_header(skb) + offset); 340 341 switch (icmp6->icmp6_type) { 342 case NDISC_ROUTER_SOLICITATION: 343 case NDISC_ROUTER_ADVERTISEMENT: 344 case NDISC_NEIGHBOUR_SOLICITATION: 345 case NDISC_NEIGHBOUR_ADVERTISEMENT: 346 case NDISC_REDIRECT: 347 /* For reaction involving unicast neighbor discovery 348 * message destined to the proxied address, pass it to 349 * input function. 350 */ 351 return 1; 352 default: 353 break; 354 } 355 } 356 357 /* 358 * The proxying router can't forward traffic sent to a link-local 359 * address, so signal the sender and discard the packet. This 360 * behavior is clarified by the MIPv6 specification. 361 */ 362 if (ipv6_addr_type(&hdr->daddr) & IPV6_ADDR_LINKLOCAL) { 363 dst_link_failure(skb); 364 return -1; 365 } 366 367 return 0; 368 } 369 370 static inline int ip6_forward_finish(struct sk_buff *skb) 371 { 372 return dst_output(skb); 373 } 374 375 int ip6_forward(struct sk_buff *skb) 376 { 377 struct dst_entry *dst = skb->dst; 378 struct ipv6hdr *hdr = ipv6_hdr(skb); 379 struct inet6_skb_parm *opt = IP6CB(skb); 380 381 if (ipv6_devconf.forwarding == 0) 382 goto error; 383 384 if (!xfrm6_policy_check(NULL, XFRM_POLICY_FWD, skb)) { 385 IP6_INC_STATS(ip6_dst_idev(dst), IPSTATS_MIB_INDISCARDS); 386 goto drop; 387 } 388 389 skb_forward_csum(skb); 390 391 /* 392 * We DO NOT make any processing on 393 * RA packets, pushing them to user level AS IS 394 * without ane WARRANTY that application will be able 395 * to interpret them. The reason is that we 396 * cannot make anything clever here. 397 * 398 * We are not end-node, so that if packet contains 399 * AH/ESP, we cannot make anything. 400 * Defragmentation also would be mistake, RA packets 401 * cannot be fragmented, because there is no warranty 402 * that different fragments will go along one path. --ANK 403 */ 404 if (opt->ra) { 405 u8 *ptr = skb_network_header(skb) + opt->ra; 406 if (ip6_call_ra_chain(skb, (ptr[2]<<8) + ptr[3])) 407 return 0; 408 } 409 410 /* 411 * check and decrement ttl 412 */ 413 if (hdr->hop_limit <= 1) { 414 /* Force OUTPUT device used as source address */ 415 skb->dev = dst->dev; 416 icmpv6_send(skb, ICMPV6_TIME_EXCEED, ICMPV6_EXC_HOPLIMIT, 417 0, skb->dev); 418 IP6_INC_STATS_BH(ip6_dst_idev(dst), IPSTATS_MIB_INHDRERRORS); 419 420 kfree_skb(skb); 421 return -ETIMEDOUT; 422 } 423 424 /* XXX: idev->cnf.proxy_ndp? */ 425 if (ipv6_devconf.proxy_ndp && 426 pneigh_lookup(&nd_tbl, &hdr->daddr, skb->dev, 0)) { 427 int proxied = ip6_forward_proxy_check(skb); 428 if (proxied > 0) 429 return ip6_input(skb); 430 else if (proxied < 0) { 431 IP6_INC_STATS(ip6_dst_idev(dst), IPSTATS_MIB_INDISCARDS); 432 goto drop; 433 } 434 } 435 436 if (!xfrm6_route_forward(skb)) { 437 IP6_INC_STATS(ip6_dst_idev(dst), IPSTATS_MIB_INDISCARDS); 438 goto drop; 439 } 440 dst = skb->dst; 441 442 /* IPv6 specs say nothing about it, but it is clear that we cannot 443 send redirects to source routed frames. 444 */ 445 if (skb->dev == dst->dev && dst->neighbour && opt->srcrt == 0) { 446 struct in6_addr *target = NULL; 447 struct rt6_info *rt; 448 struct neighbour *n = dst->neighbour; 449 450 /* 451 * incoming and outgoing devices are the same 452 * send a redirect. 453 */ 454 455 rt = (struct rt6_info *) dst; 456 if ((rt->rt6i_flags & RTF_GATEWAY)) 457 target = (struct in6_addr*)&n->primary_key; 458 else 459 target = &hdr->daddr; 460 461 /* Limit redirects both by destination (here) 462 and by source (inside ndisc_send_redirect) 463 */ 464 if (xrlim_allow(dst, 1*HZ)) 465 ndisc_send_redirect(skb, n, target); 466 } else { 467 int addrtype = ipv6_addr_type(&hdr->saddr); 468 469 /* This check is security critical. */ 470 if (addrtype & (IPV6_ADDR_MULTICAST|IPV6_ADDR_LOOPBACK)) 471 goto error; 472 if (addrtype & IPV6_ADDR_LINKLOCAL) { 473 icmpv6_send(skb, ICMPV6_DEST_UNREACH, 474 ICMPV6_NOT_NEIGHBOUR, 0, skb->dev); 475 goto error; 476 } 477 } 478 479 if (skb->len > dst_mtu(dst)) { 480 /* Again, force OUTPUT device used as source address */ 481 skb->dev = dst->dev; 482 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, dst_mtu(dst), skb->dev); 483 IP6_INC_STATS_BH(ip6_dst_idev(dst), IPSTATS_MIB_INTOOBIGERRORS); 484 IP6_INC_STATS_BH(ip6_dst_idev(dst), IPSTATS_MIB_FRAGFAILS); 485 kfree_skb(skb); 486 return -EMSGSIZE; 487 } 488 489 if (skb_cow(skb, dst->dev->hard_header_len)) { 490 IP6_INC_STATS(ip6_dst_idev(dst), IPSTATS_MIB_OUTDISCARDS); 491 goto drop; 492 } 493 494 hdr = ipv6_hdr(skb); 495 496 /* Mangling hops number delayed to point after skb COW */ 497 498 hdr->hop_limit--; 499 500 IP6_INC_STATS_BH(ip6_dst_idev(dst), IPSTATS_MIB_OUTFORWDATAGRAMS); 501 return NF_HOOK(PF_INET6,NF_IP6_FORWARD, skb, skb->dev, dst->dev, ip6_forward_finish); 502 503 error: 504 IP6_INC_STATS_BH(ip6_dst_idev(dst), IPSTATS_MIB_INADDRERRORS); 505 drop: 506 kfree_skb(skb); 507 return -EINVAL; 508 } 509 510 static void ip6_copy_metadata(struct sk_buff *to, struct sk_buff *from) 511 { 512 to->pkt_type = from->pkt_type; 513 to->priority = from->priority; 514 to->protocol = from->protocol; 515 dst_release(to->dst); 516 to->dst = dst_clone(from->dst); 517 to->dev = from->dev; 518 to->mark = from->mark; 519 520 #ifdef CONFIG_NET_SCHED 521 to->tc_index = from->tc_index; 522 #endif 523 nf_copy(to, from); 524 #if defined(CONFIG_NETFILTER_XT_TARGET_TRACE) || \ 525 defined(CONFIG_NETFILTER_XT_TARGET_TRACE_MODULE) 526 to->nf_trace = from->nf_trace; 527 #endif 528 skb_copy_secmark(to, from); 529 } 530 531 int ip6_find_1stfragopt(struct sk_buff *skb, u8 **nexthdr) 532 { 533 u16 offset = sizeof(struct ipv6hdr); 534 struct ipv6_opt_hdr *exthdr = 535 (struct ipv6_opt_hdr *)(ipv6_hdr(skb) + 1); 536 unsigned int packet_len = skb->tail - skb->network_header; 537 int found_rhdr = 0; 538 *nexthdr = &ipv6_hdr(skb)->nexthdr; 539 540 while (offset + 1 <= packet_len) { 541 542 switch (**nexthdr) { 543 544 case NEXTHDR_HOP: 545 break; 546 case NEXTHDR_ROUTING: 547 found_rhdr = 1; 548 break; 549 case NEXTHDR_DEST: 550 #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE) 551 if (ipv6_find_tlv(skb, offset, IPV6_TLV_HAO) >= 0) 552 break; 553 #endif 554 if (found_rhdr) 555 return offset; 556 break; 557 default : 558 return offset; 559 } 560 561 offset += ipv6_optlen(exthdr); 562 *nexthdr = &exthdr->nexthdr; 563 exthdr = (struct ipv6_opt_hdr *)(skb_network_header(skb) + 564 offset); 565 } 566 567 return offset; 568 } 569 EXPORT_SYMBOL_GPL(ip6_find_1stfragopt); 570 571 static int ip6_fragment(struct sk_buff *skb, int (*output)(struct sk_buff *)) 572 { 573 struct net_device *dev; 574 struct sk_buff *frag; 575 struct rt6_info *rt = (struct rt6_info*)skb->dst; 576 struct ipv6_pinfo *np = skb->sk ? inet6_sk(skb->sk) : NULL; 577 struct ipv6hdr *tmp_hdr; 578 struct frag_hdr *fh; 579 unsigned int mtu, hlen, left, len; 580 __be32 frag_id = 0; 581 int ptr, offset = 0, err=0; 582 u8 *prevhdr, nexthdr = 0; 583 584 dev = rt->u.dst.dev; 585 hlen = ip6_find_1stfragopt(skb, &prevhdr); 586 nexthdr = *prevhdr; 587 588 mtu = ip6_skb_dst_mtu(skb); 589 590 /* We must not fragment if the socket is set to force MTU discovery 591 * or if the skb it not generated by a local socket. (This last 592 * check should be redundant, but it's free.) 593 */ 594 if (!np || np->pmtudisc >= IPV6_PMTUDISC_DO) { 595 skb->dev = skb->dst->dev; 596 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu, skb->dev); 597 IP6_INC_STATS(ip6_dst_idev(skb->dst), IPSTATS_MIB_FRAGFAILS); 598 kfree_skb(skb); 599 return -EMSGSIZE; 600 } 601 602 if (np && np->frag_size < mtu) { 603 if (np->frag_size) 604 mtu = np->frag_size; 605 } 606 mtu -= hlen + sizeof(struct frag_hdr); 607 608 if (skb_shinfo(skb)->frag_list) { 609 int first_len = skb_pagelen(skb); 610 611 if (first_len - hlen > mtu || 612 ((first_len - hlen) & 7) || 613 skb_cloned(skb)) 614 goto slow_path; 615 616 for (frag = skb_shinfo(skb)->frag_list; frag; frag = frag->next) { 617 /* Correct geometry. */ 618 if (frag->len > mtu || 619 ((frag->len & 7) && frag->next) || 620 skb_headroom(frag) < hlen) 621 goto slow_path; 622 623 /* Partially cloned skb? */ 624 if (skb_shared(frag)) 625 goto slow_path; 626 627 BUG_ON(frag->sk); 628 if (skb->sk) { 629 sock_hold(skb->sk); 630 frag->sk = skb->sk; 631 frag->destructor = sock_wfree; 632 skb->truesize -= frag->truesize; 633 } 634 } 635 636 err = 0; 637 offset = 0; 638 frag = skb_shinfo(skb)->frag_list; 639 skb_shinfo(skb)->frag_list = NULL; 640 /* BUILD HEADER */ 641 642 *prevhdr = NEXTHDR_FRAGMENT; 643 tmp_hdr = kmemdup(skb_network_header(skb), hlen, GFP_ATOMIC); 644 if (!tmp_hdr) { 645 IP6_INC_STATS(ip6_dst_idev(skb->dst), IPSTATS_MIB_FRAGFAILS); 646 return -ENOMEM; 647 } 648 649 __skb_pull(skb, hlen); 650 fh = (struct frag_hdr*)__skb_push(skb, sizeof(struct frag_hdr)); 651 __skb_push(skb, hlen); 652 skb_reset_network_header(skb); 653 memcpy(skb_network_header(skb), tmp_hdr, hlen); 654 655 ipv6_select_ident(skb, fh); 656 fh->nexthdr = nexthdr; 657 fh->reserved = 0; 658 fh->frag_off = htons(IP6_MF); 659 frag_id = fh->identification; 660 661 first_len = skb_pagelen(skb); 662 skb->data_len = first_len - skb_headlen(skb); 663 skb->len = first_len; 664 ipv6_hdr(skb)->payload_len = htons(first_len - 665 sizeof(struct ipv6hdr)); 666 667 dst_hold(&rt->u.dst); 668 669 for (;;) { 670 /* Prepare header of the next frame, 671 * before previous one went down. */ 672 if (frag) { 673 frag->ip_summed = CHECKSUM_NONE; 674 skb_reset_transport_header(frag); 675 fh = (struct frag_hdr*)__skb_push(frag, sizeof(struct frag_hdr)); 676 __skb_push(frag, hlen); 677 skb_reset_network_header(frag); 678 memcpy(skb_network_header(frag), tmp_hdr, 679 hlen); 680 offset += skb->len - hlen - sizeof(struct frag_hdr); 681 fh->nexthdr = nexthdr; 682 fh->reserved = 0; 683 fh->frag_off = htons(offset); 684 if (frag->next != NULL) 685 fh->frag_off |= htons(IP6_MF); 686 fh->identification = frag_id; 687 ipv6_hdr(frag)->payload_len = 688 htons(frag->len - 689 sizeof(struct ipv6hdr)); 690 ip6_copy_metadata(frag, skb); 691 } 692 693 err = output(skb); 694 if(!err) 695 IP6_INC_STATS(ip6_dst_idev(&rt->u.dst), IPSTATS_MIB_FRAGCREATES); 696 697 if (err || !frag) 698 break; 699 700 skb = frag; 701 frag = skb->next; 702 skb->next = NULL; 703 } 704 705 kfree(tmp_hdr); 706 707 if (err == 0) { 708 IP6_INC_STATS(ip6_dst_idev(&rt->u.dst), IPSTATS_MIB_FRAGOKS); 709 dst_release(&rt->u.dst); 710 return 0; 711 } 712 713 while (frag) { 714 skb = frag->next; 715 kfree_skb(frag); 716 frag = skb; 717 } 718 719 IP6_INC_STATS(ip6_dst_idev(&rt->u.dst), IPSTATS_MIB_FRAGFAILS); 720 dst_release(&rt->u.dst); 721 return err; 722 } 723 724 slow_path: 725 left = skb->len - hlen; /* Space per frame */ 726 ptr = hlen; /* Where to start from */ 727 728 /* 729 * Fragment the datagram. 730 */ 731 732 *prevhdr = NEXTHDR_FRAGMENT; 733 734 /* 735 * Keep copying data until we run out. 736 */ 737 while(left > 0) { 738 len = left; 739 /* IF: it doesn't fit, use 'mtu' - the data space left */ 740 if (len > mtu) 741 len = mtu; 742 /* IF: we are not sending upto and including the packet end 743 then align the next start on an eight byte boundary */ 744 if (len < left) { 745 len &= ~7; 746 } 747 /* 748 * Allocate buffer. 749 */ 750 751 if ((frag = alloc_skb(len+hlen+sizeof(struct frag_hdr)+LL_RESERVED_SPACE(rt->u.dst.dev), GFP_ATOMIC)) == NULL) { 752 NETDEBUG(KERN_INFO "IPv6: frag: no memory for new fragment!\n"); 753 IP6_INC_STATS(ip6_dst_idev(skb->dst), 754 IPSTATS_MIB_FRAGFAILS); 755 err = -ENOMEM; 756 goto fail; 757 } 758 759 /* 760 * Set up data on packet 761 */ 762 763 ip6_copy_metadata(frag, skb); 764 skb_reserve(frag, LL_RESERVED_SPACE(rt->u.dst.dev)); 765 skb_put(frag, len + hlen + sizeof(struct frag_hdr)); 766 skb_reset_network_header(frag); 767 fh = (struct frag_hdr *)(skb_network_header(frag) + hlen); 768 frag->transport_header = (frag->network_header + hlen + 769 sizeof(struct frag_hdr)); 770 771 /* 772 * Charge the memory for the fragment to any owner 773 * it might possess 774 */ 775 if (skb->sk) 776 skb_set_owner_w(frag, skb->sk); 777 778 /* 779 * Copy the packet header into the new buffer. 780 */ 781 skb_copy_from_linear_data(skb, skb_network_header(frag), hlen); 782 783 /* 784 * Build fragment header. 785 */ 786 fh->nexthdr = nexthdr; 787 fh->reserved = 0; 788 if (!frag_id) { 789 ipv6_select_ident(skb, fh); 790 frag_id = fh->identification; 791 } else 792 fh->identification = frag_id; 793 794 /* 795 * Copy a block of the IP datagram. 796 */ 797 if (skb_copy_bits(skb, ptr, skb_transport_header(skb), len)) 798 BUG(); 799 left -= len; 800 801 fh->frag_off = htons(offset); 802 if (left > 0) 803 fh->frag_off |= htons(IP6_MF); 804 ipv6_hdr(frag)->payload_len = htons(frag->len - 805 sizeof(struct ipv6hdr)); 806 807 ptr += len; 808 offset += len; 809 810 /* 811 * Put this fragment into the sending queue. 812 */ 813 err = output(frag); 814 if (err) 815 goto fail; 816 817 IP6_INC_STATS(ip6_dst_idev(skb->dst), IPSTATS_MIB_FRAGCREATES); 818 } 819 IP6_INC_STATS(ip6_dst_idev(skb->dst), 820 IPSTATS_MIB_FRAGOKS); 821 kfree_skb(skb); 822 return err; 823 824 fail: 825 IP6_INC_STATS(ip6_dst_idev(skb->dst), 826 IPSTATS_MIB_FRAGFAILS); 827 kfree_skb(skb); 828 return err; 829 } 830 831 static inline int ip6_rt_check(struct rt6key *rt_key, 832 struct in6_addr *fl_addr, 833 struct in6_addr *addr_cache) 834 { 835 return ((rt_key->plen != 128 || !ipv6_addr_equal(fl_addr, &rt_key->addr)) && 836 (addr_cache == NULL || !ipv6_addr_equal(fl_addr, addr_cache))); 837 } 838 839 static struct dst_entry *ip6_sk_dst_check(struct sock *sk, 840 struct dst_entry *dst, 841 struct flowi *fl) 842 { 843 struct ipv6_pinfo *np = inet6_sk(sk); 844 struct rt6_info *rt = (struct rt6_info *)dst; 845 846 if (!dst) 847 goto out; 848 849 /* Yes, checking route validity in not connected 850 * case is not very simple. Take into account, 851 * that we do not support routing by source, TOS, 852 * and MSG_DONTROUTE --ANK (980726) 853 * 854 * 1. ip6_rt_check(): If route was host route, 855 * check that cached destination is current. 856 * If it is network route, we still may 857 * check its validity using saved pointer 858 * to the last used address: daddr_cache. 859 * We do not want to save whole address now, 860 * (because main consumer of this service 861 * is tcp, which has not this problem), 862 * so that the last trick works only on connected 863 * sockets. 864 * 2. oif also should be the same. 865 */ 866 if (ip6_rt_check(&rt->rt6i_dst, &fl->fl6_dst, np->daddr_cache) || 867 #ifdef CONFIG_IPV6_SUBTREES 868 ip6_rt_check(&rt->rt6i_src, &fl->fl6_src, np->saddr_cache) || 869 #endif 870 (fl->oif && fl->oif != dst->dev->ifindex)) { 871 dst_release(dst); 872 dst = NULL; 873 } 874 875 out: 876 return dst; 877 } 878 879 static int ip6_dst_lookup_tail(struct sock *sk, 880 struct dst_entry **dst, struct flowi *fl) 881 { 882 int err; 883 884 if (*dst == NULL) 885 *dst = ip6_route_output(sk, fl); 886 887 if ((err = (*dst)->error)) 888 goto out_err_release; 889 890 if (ipv6_addr_any(&fl->fl6_src)) { 891 err = ipv6_get_saddr(*dst, &fl->fl6_dst, &fl->fl6_src); 892 if (err) 893 goto out_err_release; 894 } 895 896 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD 897 /* 898 * Here if the dst entry we've looked up 899 * has a neighbour entry that is in the INCOMPLETE 900 * state and the src address from the flow is 901 * marked as OPTIMISTIC, we release the found 902 * dst entry and replace it instead with the 903 * dst entry of the nexthop router 904 */ 905 if (!((*dst)->neighbour->nud_state & NUD_VALID)) { 906 struct inet6_ifaddr *ifp; 907 struct flowi fl_gw; 908 int redirect; 909 910 ifp = ipv6_get_ifaddr(&fl->fl6_src, (*dst)->dev, 1); 911 912 redirect = (ifp && ifp->flags & IFA_F_OPTIMISTIC); 913 if (ifp) 914 in6_ifa_put(ifp); 915 916 if (redirect) { 917 /* 918 * We need to get the dst entry for the 919 * default router instead 920 */ 921 dst_release(*dst); 922 memcpy(&fl_gw, fl, sizeof(struct flowi)); 923 memset(&fl_gw.fl6_dst, 0, sizeof(struct in6_addr)); 924 *dst = ip6_route_output(sk, &fl_gw); 925 if ((err = (*dst)->error)) 926 goto out_err_release; 927 } 928 } 929 #endif 930 931 return 0; 932 933 out_err_release: 934 dst_release(*dst); 935 *dst = NULL; 936 return err; 937 } 938 939 /** 940 * ip6_dst_lookup - perform route lookup on flow 941 * @sk: socket which provides route info 942 * @dst: pointer to dst_entry * for result 943 * @fl: flow to lookup 944 * 945 * This function performs a route lookup on the given flow. 946 * 947 * It returns zero on success, or a standard errno code on error. 948 */ 949 int ip6_dst_lookup(struct sock *sk, struct dst_entry **dst, struct flowi *fl) 950 { 951 *dst = NULL; 952 return ip6_dst_lookup_tail(sk, dst, fl); 953 } 954 EXPORT_SYMBOL_GPL(ip6_dst_lookup); 955 956 /** 957 * ip6_sk_dst_lookup - perform socket cached route lookup on flow 958 * @sk: socket which provides the dst cache and route info 959 * @dst: pointer to dst_entry * for result 960 * @fl: flow to lookup 961 * 962 * This function performs a route lookup on the given flow with the 963 * possibility of using the cached route in the socket if it is valid. 964 * It will take the socket dst lock when operating on the dst cache. 965 * As a result, this function can only be used in process context. 966 * 967 * It returns zero on success, or a standard errno code on error. 968 */ 969 int ip6_sk_dst_lookup(struct sock *sk, struct dst_entry **dst, struct flowi *fl) 970 { 971 *dst = NULL; 972 if (sk) { 973 *dst = sk_dst_check(sk, inet6_sk(sk)->dst_cookie); 974 *dst = ip6_sk_dst_check(sk, *dst, fl); 975 } 976 977 return ip6_dst_lookup_tail(sk, dst, fl); 978 } 979 EXPORT_SYMBOL_GPL(ip6_sk_dst_lookup); 980 981 static inline int ip6_ufo_append_data(struct sock *sk, 982 int getfrag(void *from, char *to, int offset, int len, 983 int odd, struct sk_buff *skb), 984 void *from, int length, int hh_len, int fragheaderlen, 985 int transhdrlen, int mtu,unsigned int flags) 986 987 { 988 struct sk_buff *skb; 989 int err; 990 991 /* There is support for UDP large send offload by network 992 * device, so create one single skb packet containing complete 993 * udp datagram 994 */ 995 if ((skb = skb_peek_tail(&sk->sk_write_queue)) == NULL) { 996 skb = sock_alloc_send_skb(sk, 997 hh_len + fragheaderlen + transhdrlen + 20, 998 (flags & MSG_DONTWAIT), &err); 999 if (skb == NULL) 1000 return -ENOMEM; 1001 1002 /* reserve space for Hardware header */ 1003 skb_reserve(skb, hh_len); 1004 1005 /* create space for UDP/IP header */ 1006 skb_put(skb,fragheaderlen + transhdrlen); 1007 1008 /* initialize network header pointer */ 1009 skb_reset_network_header(skb); 1010 1011 /* initialize protocol header pointer */ 1012 skb->transport_header = skb->network_header + fragheaderlen; 1013 1014 skb->ip_summed = CHECKSUM_PARTIAL; 1015 skb->csum = 0; 1016 sk->sk_sndmsg_off = 0; 1017 } 1018 1019 err = skb_append_datato_frags(sk,skb, getfrag, from, 1020 (length - transhdrlen)); 1021 if (!err) { 1022 struct frag_hdr fhdr; 1023 1024 /* specify the length of each IP datagram fragment*/ 1025 skb_shinfo(skb)->gso_size = mtu - fragheaderlen - 1026 sizeof(struct frag_hdr); 1027 skb_shinfo(skb)->gso_type = SKB_GSO_UDP; 1028 ipv6_select_ident(skb, &fhdr); 1029 skb_shinfo(skb)->ip6_frag_id = fhdr.identification; 1030 __skb_queue_tail(&sk->sk_write_queue, skb); 1031 1032 return 0; 1033 } 1034 /* There is not enough support do UPD LSO, 1035 * so follow normal path 1036 */ 1037 kfree_skb(skb); 1038 1039 return err; 1040 } 1041 1042 int ip6_append_data(struct sock *sk, int getfrag(void *from, char *to, 1043 int offset, int len, int odd, struct sk_buff *skb), 1044 void *from, int length, int transhdrlen, 1045 int hlimit, int tclass, struct ipv6_txoptions *opt, struct flowi *fl, 1046 struct rt6_info *rt, unsigned int flags) 1047 { 1048 struct inet_sock *inet = inet_sk(sk); 1049 struct ipv6_pinfo *np = inet6_sk(sk); 1050 struct sk_buff *skb; 1051 unsigned int maxfraglen, fragheaderlen; 1052 int exthdrlen; 1053 int hh_len; 1054 int mtu; 1055 int copy; 1056 int err; 1057 int offset = 0; 1058 int csummode = CHECKSUM_NONE; 1059 1060 if (flags&MSG_PROBE) 1061 return 0; 1062 if (skb_queue_empty(&sk->sk_write_queue)) { 1063 /* 1064 * setup for corking 1065 */ 1066 if (opt) { 1067 if (np->cork.opt == NULL) { 1068 np->cork.opt = kmalloc(opt->tot_len, 1069 sk->sk_allocation); 1070 if (unlikely(np->cork.opt == NULL)) 1071 return -ENOBUFS; 1072 } else if (np->cork.opt->tot_len < opt->tot_len) { 1073 printk(KERN_DEBUG "ip6_append_data: invalid option length\n"); 1074 return -EINVAL; 1075 } 1076 memcpy(np->cork.opt, opt, opt->tot_len); 1077 inet->cork.flags |= IPCORK_OPT; 1078 /* need source address above miyazawa*/ 1079 } 1080 dst_hold(&rt->u.dst); 1081 np->cork.rt = rt; 1082 inet->cork.fl = *fl; 1083 np->cork.hop_limit = hlimit; 1084 np->cork.tclass = tclass; 1085 mtu = np->pmtudisc == IPV6_PMTUDISC_PROBE ? 1086 rt->u.dst.dev->mtu : dst_mtu(rt->u.dst.path); 1087 if (np->frag_size < mtu) { 1088 if (np->frag_size) 1089 mtu = np->frag_size; 1090 } 1091 inet->cork.fragsize = mtu; 1092 if (dst_allfrag(rt->u.dst.path)) 1093 inet->cork.flags |= IPCORK_ALLFRAG; 1094 inet->cork.length = 0; 1095 sk->sk_sndmsg_page = NULL; 1096 sk->sk_sndmsg_off = 0; 1097 exthdrlen = rt->u.dst.header_len + (opt ? opt->opt_flen : 0); 1098 length += exthdrlen; 1099 transhdrlen += exthdrlen; 1100 } else { 1101 rt = np->cork.rt; 1102 fl = &inet->cork.fl; 1103 if (inet->cork.flags & IPCORK_OPT) 1104 opt = np->cork.opt; 1105 transhdrlen = 0; 1106 exthdrlen = 0; 1107 mtu = inet->cork.fragsize; 1108 } 1109 1110 hh_len = LL_RESERVED_SPACE(rt->u.dst.dev); 1111 1112 fragheaderlen = sizeof(struct ipv6hdr) + rt->u.dst.nfheader_len + (opt ? opt->opt_nflen : 0); 1113 maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen - sizeof(struct frag_hdr); 1114 1115 if (mtu <= sizeof(struct ipv6hdr) + IPV6_MAXPLEN) { 1116 if (inet->cork.length + length > sizeof(struct ipv6hdr) + IPV6_MAXPLEN - fragheaderlen) { 1117 ipv6_local_error(sk, EMSGSIZE, fl, mtu-exthdrlen); 1118 return -EMSGSIZE; 1119 } 1120 } 1121 1122 /* 1123 * Let's try using as much space as possible. 1124 * Use MTU if total length of the message fits into the MTU. 1125 * Otherwise, we need to reserve fragment header and 1126 * fragment alignment (= 8-15 octects, in total). 1127 * 1128 * Note that we may need to "move" the data from the tail of 1129 * of the buffer to the new fragment when we split 1130 * the message. 1131 * 1132 * FIXME: It may be fragmented into multiple chunks 1133 * at once if non-fragmentable extension headers 1134 * are too large. 1135 * --yoshfuji 1136 */ 1137 1138 inet->cork.length += length; 1139 if (((length > mtu) && (sk->sk_protocol == IPPROTO_UDP)) && 1140 (rt->u.dst.dev->features & NETIF_F_UFO)) { 1141 1142 err = ip6_ufo_append_data(sk, getfrag, from, length, hh_len, 1143 fragheaderlen, transhdrlen, mtu, 1144 flags); 1145 if (err) 1146 goto error; 1147 return 0; 1148 } 1149 1150 if ((skb = skb_peek_tail(&sk->sk_write_queue)) == NULL) 1151 goto alloc_new_skb; 1152 1153 while (length > 0) { 1154 /* Check if the remaining data fits into current packet. */ 1155 copy = (inet->cork.length <= mtu && !(inet->cork.flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - skb->len; 1156 if (copy < length) 1157 copy = maxfraglen - skb->len; 1158 1159 if (copy <= 0) { 1160 char *data; 1161 unsigned int datalen; 1162 unsigned int fraglen; 1163 unsigned int fraggap; 1164 unsigned int alloclen; 1165 struct sk_buff *skb_prev; 1166 alloc_new_skb: 1167 skb_prev = skb; 1168 1169 /* There's no room in the current skb */ 1170 if (skb_prev) 1171 fraggap = skb_prev->len - maxfraglen; 1172 else 1173 fraggap = 0; 1174 1175 /* 1176 * If remaining data exceeds the mtu, 1177 * we know we need more fragment(s). 1178 */ 1179 datalen = length + fraggap; 1180 if (datalen > (inet->cork.length <= mtu && !(inet->cork.flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - fragheaderlen) 1181 datalen = maxfraglen - fragheaderlen; 1182 1183 fraglen = datalen + fragheaderlen; 1184 if ((flags & MSG_MORE) && 1185 !(rt->u.dst.dev->features&NETIF_F_SG)) 1186 alloclen = mtu; 1187 else 1188 alloclen = datalen + fragheaderlen; 1189 1190 /* 1191 * The last fragment gets additional space at tail. 1192 * Note: we overallocate on fragments with MSG_MODE 1193 * because we have no idea if we're the last one. 1194 */ 1195 if (datalen == length + fraggap) 1196 alloclen += rt->u.dst.trailer_len; 1197 1198 /* 1199 * We just reserve space for fragment header. 1200 * Note: this may be overallocation if the message 1201 * (without MSG_MORE) fits into the MTU. 1202 */ 1203 alloclen += sizeof(struct frag_hdr); 1204 1205 if (transhdrlen) { 1206 skb = sock_alloc_send_skb(sk, 1207 alloclen + hh_len, 1208 (flags & MSG_DONTWAIT), &err); 1209 } else { 1210 skb = NULL; 1211 if (atomic_read(&sk->sk_wmem_alloc) <= 1212 2 * sk->sk_sndbuf) 1213 skb = sock_wmalloc(sk, 1214 alloclen + hh_len, 1, 1215 sk->sk_allocation); 1216 if (unlikely(skb == NULL)) 1217 err = -ENOBUFS; 1218 } 1219 if (skb == NULL) 1220 goto error; 1221 /* 1222 * Fill in the control structures 1223 */ 1224 skb->ip_summed = csummode; 1225 skb->csum = 0; 1226 /* reserve for fragmentation */ 1227 skb_reserve(skb, hh_len+sizeof(struct frag_hdr)); 1228 1229 /* 1230 * Find where to start putting bytes 1231 */ 1232 data = skb_put(skb, fraglen); 1233 skb_set_network_header(skb, exthdrlen); 1234 data += fragheaderlen; 1235 skb->transport_header = (skb->network_header + 1236 fragheaderlen); 1237 if (fraggap) { 1238 skb->csum = skb_copy_and_csum_bits( 1239 skb_prev, maxfraglen, 1240 data + transhdrlen, fraggap, 0); 1241 skb_prev->csum = csum_sub(skb_prev->csum, 1242 skb->csum); 1243 data += fraggap; 1244 pskb_trim_unique(skb_prev, maxfraglen); 1245 } 1246 copy = datalen - transhdrlen - fraggap; 1247 if (copy < 0) { 1248 err = -EINVAL; 1249 kfree_skb(skb); 1250 goto error; 1251 } else if (copy > 0 && getfrag(from, data + transhdrlen, offset, copy, fraggap, skb) < 0) { 1252 err = -EFAULT; 1253 kfree_skb(skb); 1254 goto error; 1255 } 1256 1257 offset += copy; 1258 length -= datalen - fraggap; 1259 transhdrlen = 0; 1260 exthdrlen = 0; 1261 csummode = CHECKSUM_NONE; 1262 1263 /* 1264 * Put the packet on the pending queue 1265 */ 1266 __skb_queue_tail(&sk->sk_write_queue, skb); 1267 continue; 1268 } 1269 1270 if (copy > length) 1271 copy = length; 1272 1273 if (!(rt->u.dst.dev->features&NETIF_F_SG)) { 1274 unsigned int off; 1275 1276 off = skb->len; 1277 if (getfrag(from, skb_put(skb, copy), 1278 offset, copy, off, skb) < 0) { 1279 __skb_trim(skb, off); 1280 err = -EFAULT; 1281 goto error; 1282 } 1283 } else { 1284 int i = skb_shinfo(skb)->nr_frags; 1285 skb_frag_t *frag = &skb_shinfo(skb)->frags[i-1]; 1286 struct page *page = sk->sk_sndmsg_page; 1287 int off = sk->sk_sndmsg_off; 1288 unsigned int left; 1289 1290 if (page && (left = PAGE_SIZE - off) > 0) { 1291 if (copy >= left) 1292 copy = left; 1293 if (page != frag->page) { 1294 if (i == MAX_SKB_FRAGS) { 1295 err = -EMSGSIZE; 1296 goto error; 1297 } 1298 get_page(page); 1299 skb_fill_page_desc(skb, i, page, sk->sk_sndmsg_off, 0); 1300 frag = &skb_shinfo(skb)->frags[i]; 1301 } 1302 } else if(i < MAX_SKB_FRAGS) { 1303 if (copy > PAGE_SIZE) 1304 copy = PAGE_SIZE; 1305 page = alloc_pages(sk->sk_allocation, 0); 1306 if (page == NULL) { 1307 err = -ENOMEM; 1308 goto error; 1309 } 1310 sk->sk_sndmsg_page = page; 1311 sk->sk_sndmsg_off = 0; 1312 1313 skb_fill_page_desc(skb, i, page, 0, 0); 1314 frag = &skb_shinfo(skb)->frags[i]; 1315 skb->truesize += PAGE_SIZE; 1316 atomic_add(PAGE_SIZE, &sk->sk_wmem_alloc); 1317 } else { 1318 err = -EMSGSIZE; 1319 goto error; 1320 } 1321 if (getfrag(from, page_address(frag->page)+frag->page_offset+frag->size, offset, copy, skb->len, skb) < 0) { 1322 err = -EFAULT; 1323 goto error; 1324 } 1325 sk->sk_sndmsg_off += copy; 1326 frag->size += copy; 1327 skb->len += copy; 1328 skb->data_len += copy; 1329 } 1330 offset += copy; 1331 length -= copy; 1332 } 1333 return 0; 1334 error: 1335 inet->cork.length -= length; 1336 IP6_INC_STATS(rt->rt6i_idev, IPSTATS_MIB_OUTDISCARDS); 1337 return err; 1338 } 1339 1340 int ip6_push_pending_frames(struct sock *sk) 1341 { 1342 struct sk_buff *skb, *tmp_skb; 1343 struct sk_buff **tail_skb; 1344 struct in6_addr final_dst_buf, *final_dst = &final_dst_buf; 1345 struct inet_sock *inet = inet_sk(sk); 1346 struct ipv6_pinfo *np = inet6_sk(sk); 1347 struct ipv6hdr *hdr; 1348 struct ipv6_txoptions *opt = np->cork.opt; 1349 struct rt6_info *rt = np->cork.rt; 1350 struct flowi *fl = &inet->cork.fl; 1351 unsigned char proto = fl->proto; 1352 int err = 0; 1353 1354 if ((skb = __skb_dequeue(&sk->sk_write_queue)) == NULL) 1355 goto out; 1356 tail_skb = &(skb_shinfo(skb)->frag_list); 1357 1358 /* move skb->data to ip header from ext header */ 1359 if (skb->data < skb_network_header(skb)) 1360 __skb_pull(skb, skb_network_offset(skb)); 1361 while ((tmp_skb = __skb_dequeue(&sk->sk_write_queue)) != NULL) { 1362 __skb_pull(tmp_skb, skb_network_header_len(skb)); 1363 *tail_skb = tmp_skb; 1364 tail_skb = &(tmp_skb->next); 1365 skb->len += tmp_skb->len; 1366 skb->data_len += tmp_skb->len; 1367 skb->truesize += tmp_skb->truesize; 1368 __sock_put(tmp_skb->sk); 1369 tmp_skb->destructor = NULL; 1370 tmp_skb->sk = NULL; 1371 } 1372 1373 ipv6_addr_copy(final_dst, &fl->fl6_dst); 1374 __skb_pull(skb, skb_network_header_len(skb)); 1375 if (opt && opt->opt_flen) 1376 ipv6_push_frag_opts(skb, opt, &proto); 1377 if (opt && opt->opt_nflen) 1378 ipv6_push_nfrag_opts(skb, opt, &proto, &final_dst); 1379 1380 skb_push(skb, sizeof(struct ipv6hdr)); 1381 skb_reset_network_header(skb); 1382 hdr = ipv6_hdr(skb); 1383 1384 *(__be32*)hdr = fl->fl6_flowlabel | 1385 htonl(0x60000000 | ((int)np->cork.tclass << 20)); 1386 1387 if (skb->len <= sizeof(struct ipv6hdr) + IPV6_MAXPLEN) 1388 hdr->payload_len = htons(skb->len - sizeof(struct ipv6hdr)); 1389 else 1390 hdr->payload_len = 0; 1391 hdr->hop_limit = np->cork.hop_limit; 1392 hdr->nexthdr = proto; 1393 ipv6_addr_copy(&hdr->saddr, &fl->fl6_src); 1394 ipv6_addr_copy(&hdr->daddr, final_dst); 1395 1396 skb->priority = sk->sk_priority; 1397 1398 skb->dst = dst_clone(&rt->u.dst); 1399 IP6_INC_STATS(rt->rt6i_idev, IPSTATS_MIB_OUTREQUESTS); 1400 err = NF_HOOK(PF_INET6, NF_IP6_LOCAL_OUT, skb, NULL, skb->dst->dev, dst_output); 1401 if (err) { 1402 if (err > 0) 1403 err = np->recverr ? net_xmit_errno(err) : 0; 1404 if (err) 1405 goto error; 1406 } 1407 1408 out: 1409 inet->cork.flags &= ~IPCORK_OPT; 1410 kfree(np->cork.opt); 1411 np->cork.opt = NULL; 1412 if (np->cork.rt) { 1413 dst_release(&np->cork.rt->u.dst); 1414 np->cork.rt = NULL; 1415 inet->cork.flags &= ~IPCORK_ALLFRAG; 1416 } 1417 memset(&inet->cork.fl, 0, sizeof(inet->cork.fl)); 1418 return err; 1419 error: 1420 goto out; 1421 } 1422 1423 void ip6_flush_pending_frames(struct sock *sk) 1424 { 1425 struct inet_sock *inet = inet_sk(sk); 1426 struct ipv6_pinfo *np = inet6_sk(sk); 1427 struct sk_buff *skb; 1428 1429 while ((skb = __skb_dequeue_tail(&sk->sk_write_queue)) != NULL) { 1430 IP6_INC_STATS(ip6_dst_idev(skb->dst), 1431 IPSTATS_MIB_OUTDISCARDS); 1432 kfree_skb(skb); 1433 } 1434 1435 inet->cork.flags &= ~IPCORK_OPT; 1436 1437 kfree(np->cork.opt); 1438 np->cork.opt = NULL; 1439 if (np->cork.rt) { 1440 dst_release(&np->cork.rt->u.dst); 1441 np->cork.rt = NULL; 1442 inet->cork.flags &= ~IPCORK_ALLFRAG; 1443 } 1444 memset(&inet->cork.fl, 0, sizeof(inet->cork.fl)); 1445 } 1446