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 skb_copy_secmark(to, from); 525 } 526 527 int ip6_find_1stfragopt(struct sk_buff *skb, u8 **nexthdr) 528 { 529 u16 offset = sizeof(struct ipv6hdr); 530 struct ipv6_opt_hdr *exthdr = 531 (struct ipv6_opt_hdr *)(ipv6_hdr(skb) + 1); 532 unsigned int packet_len = skb->tail - skb->network_header; 533 int found_rhdr = 0; 534 *nexthdr = &ipv6_hdr(skb)->nexthdr; 535 536 while (offset + 1 <= packet_len) { 537 538 switch (**nexthdr) { 539 540 case NEXTHDR_HOP: 541 break; 542 case NEXTHDR_ROUTING: 543 found_rhdr = 1; 544 break; 545 case NEXTHDR_DEST: 546 #ifdef CONFIG_IPV6_MIP6 547 if (ipv6_find_tlv(skb, offset, IPV6_TLV_HAO) >= 0) 548 break; 549 #endif 550 if (found_rhdr) 551 return offset; 552 break; 553 default : 554 return offset; 555 } 556 557 offset += ipv6_optlen(exthdr); 558 *nexthdr = &exthdr->nexthdr; 559 exthdr = (struct ipv6_opt_hdr *)(skb_network_header(skb) + 560 offset); 561 } 562 563 return offset; 564 } 565 EXPORT_SYMBOL_GPL(ip6_find_1stfragopt); 566 567 static int ip6_fragment(struct sk_buff *skb, int (*output)(struct sk_buff *)) 568 { 569 struct net_device *dev; 570 struct sk_buff *frag; 571 struct rt6_info *rt = (struct rt6_info*)skb->dst; 572 struct ipv6_pinfo *np = skb->sk ? inet6_sk(skb->sk) : NULL; 573 struct ipv6hdr *tmp_hdr; 574 struct frag_hdr *fh; 575 unsigned int mtu, hlen, left, len; 576 __be32 frag_id = 0; 577 int ptr, offset = 0, err=0; 578 u8 *prevhdr, nexthdr = 0; 579 580 dev = rt->u.dst.dev; 581 hlen = ip6_find_1stfragopt(skb, &prevhdr); 582 nexthdr = *prevhdr; 583 584 mtu = ip6_skb_dst_mtu(skb); 585 586 /* We must not fragment if the socket is set to force MTU discovery 587 * or if the skb it not generated by a local socket. (This last 588 * check should be redundant, but it's free.) 589 */ 590 if (!np || np->pmtudisc >= IPV6_PMTUDISC_DO) { 591 skb->dev = skb->dst->dev; 592 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu, skb->dev); 593 IP6_INC_STATS(ip6_dst_idev(skb->dst), IPSTATS_MIB_FRAGFAILS); 594 kfree_skb(skb); 595 return -EMSGSIZE; 596 } 597 598 if (np && np->frag_size < mtu) { 599 if (np->frag_size) 600 mtu = np->frag_size; 601 } 602 mtu -= hlen + sizeof(struct frag_hdr); 603 604 if (skb_shinfo(skb)->frag_list) { 605 int first_len = skb_pagelen(skb); 606 607 if (first_len - hlen > mtu || 608 ((first_len - hlen) & 7) || 609 skb_cloned(skb)) 610 goto slow_path; 611 612 for (frag = skb_shinfo(skb)->frag_list; frag; frag = frag->next) { 613 /* Correct geometry. */ 614 if (frag->len > mtu || 615 ((frag->len & 7) && frag->next) || 616 skb_headroom(frag) < hlen) 617 goto slow_path; 618 619 /* Partially cloned skb? */ 620 if (skb_shared(frag)) 621 goto slow_path; 622 623 BUG_ON(frag->sk); 624 if (skb->sk) { 625 sock_hold(skb->sk); 626 frag->sk = skb->sk; 627 frag->destructor = sock_wfree; 628 skb->truesize -= frag->truesize; 629 } 630 } 631 632 err = 0; 633 offset = 0; 634 frag = skb_shinfo(skb)->frag_list; 635 skb_shinfo(skb)->frag_list = NULL; 636 /* BUILD HEADER */ 637 638 *prevhdr = NEXTHDR_FRAGMENT; 639 tmp_hdr = kmemdup(skb_network_header(skb), hlen, GFP_ATOMIC); 640 if (!tmp_hdr) { 641 IP6_INC_STATS(ip6_dst_idev(skb->dst), IPSTATS_MIB_FRAGFAILS); 642 return -ENOMEM; 643 } 644 645 __skb_pull(skb, hlen); 646 fh = (struct frag_hdr*)__skb_push(skb, sizeof(struct frag_hdr)); 647 __skb_push(skb, hlen); 648 skb_reset_network_header(skb); 649 memcpy(skb_network_header(skb), tmp_hdr, hlen); 650 651 ipv6_select_ident(skb, fh); 652 fh->nexthdr = nexthdr; 653 fh->reserved = 0; 654 fh->frag_off = htons(IP6_MF); 655 frag_id = fh->identification; 656 657 first_len = skb_pagelen(skb); 658 skb->data_len = first_len - skb_headlen(skb); 659 skb->len = first_len; 660 ipv6_hdr(skb)->payload_len = htons(first_len - 661 sizeof(struct ipv6hdr)); 662 663 dst_hold(&rt->u.dst); 664 665 for (;;) { 666 /* Prepare header of the next frame, 667 * before previous one went down. */ 668 if (frag) { 669 frag->ip_summed = CHECKSUM_NONE; 670 skb_reset_transport_header(frag); 671 fh = (struct frag_hdr*)__skb_push(frag, sizeof(struct frag_hdr)); 672 __skb_push(frag, hlen); 673 skb_reset_network_header(frag); 674 memcpy(skb_network_header(frag), tmp_hdr, 675 hlen); 676 offset += skb->len - hlen - sizeof(struct frag_hdr); 677 fh->nexthdr = nexthdr; 678 fh->reserved = 0; 679 fh->frag_off = htons(offset); 680 if (frag->next != NULL) 681 fh->frag_off |= htons(IP6_MF); 682 fh->identification = frag_id; 683 ipv6_hdr(frag)->payload_len = 684 htons(frag->len - 685 sizeof(struct ipv6hdr)); 686 ip6_copy_metadata(frag, skb); 687 } 688 689 err = output(skb); 690 if(!err) 691 IP6_INC_STATS(ip6_dst_idev(&rt->u.dst), IPSTATS_MIB_FRAGCREATES); 692 693 if (err || !frag) 694 break; 695 696 skb = frag; 697 frag = skb->next; 698 skb->next = NULL; 699 } 700 701 kfree(tmp_hdr); 702 703 if (err == 0) { 704 IP6_INC_STATS(ip6_dst_idev(&rt->u.dst), IPSTATS_MIB_FRAGOKS); 705 dst_release(&rt->u.dst); 706 return 0; 707 } 708 709 while (frag) { 710 skb = frag->next; 711 kfree_skb(frag); 712 frag = skb; 713 } 714 715 IP6_INC_STATS(ip6_dst_idev(&rt->u.dst), IPSTATS_MIB_FRAGFAILS); 716 dst_release(&rt->u.dst); 717 return err; 718 } 719 720 slow_path: 721 left = skb->len - hlen; /* Space per frame */ 722 ptr = hlen; /* Where to start from */ 723 724 /* 725 * Fragment the datagram. 726 */ 727 728 *prevhdr = NEXTHDR_FRAGMENT; 729 730 /* 731 * Keep copying data until we run out. 732 */ 733 while(left > 0) { 734 len = left; 735 /* IF: it doesn't fit, use 'mtu' - the data space left */ 736 if (len > mtu) 737 len = mtu; 738 /* IF: we are not sending upto and including the packet end 739 then align the next start on an eight byte boundary */ 740 if (len < left) { 741 len &= ~7; 742 } 743 /* 744 * Allocate buffer. 745 */ 746 747 if ((frag = alloc_skb(len+hlen+sizeof(struct frag_hdr)+LL_RESERVED_SPACE(rt->u.dst.dev), GFP_ATOMIC)) == NULL) { 748 NETDEBUG(KERN_INFO "IPv6: frag: no memory for new fragment!\n"); 749 IP6_INC_STATS(ip6_dst_idev(skb->dst), 750 IPSTATS_MIB_FRAGFAILS); 751 err = -ENOMEM; 752 goto fail; 753 } 754 755 /* 756 * Set up data on packet 757 */ 758 759 ip6_copy_metadata(frag, skb); 760 skb_reserve(frag, LL_RESERVED_SPACE(rt->u.dst.dev)); 761 skb_put(frag, len + hlen + sizeof(struct frag_hdr)); 762 skb_reset_network_header(frag); 763 fh = (struct frag_hdr *)(skb_network_header(frag) + hlen); 764 frag->transport_header = (frag->network_header + hlen + 765 sizeof(struct frag_hdr)); 766 767 /* 768 * Charge the memory for the fragment to any owner 769 * it might possess 770 */ 771 if (skb->sk) 772 skb_set_owner_w(frag, skb->sk); 773 774 /* 775 * Copy the packet header into the new buffer. 776 */ 777 skb_copy_from_linear_data(skb, skb_network_header(frag), hlen); 778 779 /* 780 * Build fragment header. 781 */ 782 fh->nexthdr = nexthdr; 783 fh->reserved = 0; 784 if (!frag_id) { 785 ipv6_select_ident(skb, fh); 786 frag_id = fh->identification; 787 } else 788 fh->identification = frag_id; 789 790 /* 791 * Copy a block of the IP datagram. 792 */ 793 if (skb_copy_bits(skb, ptr, skb_transport_header(skb), len)) 794 BUG(); 795 left -= len; 796 797 fh->frag_off = htons(offset); 798 if (left > 0) 799 fh->frag_off |= htons(IP6_MF); 800 ipv6_hdr(frag)->payload_len = htons(frag->len - 801 sizeof(struct ipv6hdr)); 802 803 ptr += len; 804 offset += len; 805 806 /* 807 * Put this fragment into the sending queue. 808 */ 809 err = output(frag); 810 if (err) 811 goto fail; 812 813 IP6_INC_STATS(ip6_dst_idev(skb->dst), IPSTATS_MIB_FRAGCREATES); 814 } 815 IP6_INC_STATS(ip6_dst_idev(skb->dst), 816 IPSTATS_MIB_FRAGOKS); 817 kfree_skb(skb); 818 return err; 819 820 fail: 821 IP6_INC_STATS(ip6_dst_idev(skb->dst), 822 IPSTATS_MIB_FRAGFAILS); 823 kfree_skb(skb); 824 return err; 825 } 826 827 static inline int ip6_rt_check(struct rt6key *rt_key, 828 struct in6_addr *fl_addr, 829 struct in6_addr *addr_cache) 830 { 831 return ((rt_key->plen != 128 || !ipv6_addr_equal(fl_addr, &rt_key->addr)) && 832 (addr_cache == NULL || !ipv6_addr_equal(fl_addr, addr_cache))); 833 } 834 835 static struct dst_entry *ip6_sk_dst_check(struct sock *sk, 836 struct dst_entry *dst, 837 struct flowi *fl) 838 { 839 struct ipv6_pinfo *np = inet6_sk(sk); 840 struct rt6_info *rt = (struct rt6_info *)dst; 841 842 if (!dst) 843 goto out; 844 845 /* Yes, checking route validity in not connected 846 * case is not very simple. Take into account, 847 * that we do not support routing by source, TOS, 848 * and MSG_DONTROUTE --ANK (980726) 849 * 850 * 1. ip6_rt_check(): If route was host route, 851 * check that cached destination is current. 852 * If it is network route, we still may 853 * check its validity using saved pointer 854 * to the last used address: daddr_cache. 855 * We do not want to save whole address now, 856 * (because main consumer of this service 857 * is tcp, which has not this problem), 858 * so that the last trick works only on connected 859 * sockets. 860 * 2. oif also should be the same. 861 */ 862 if (ip6_rt_check(&rt->rt6i_dst, &fl->fl6_dst, np->daddr_cache) || 863 #ifdef CONFIG_IPV6_SUBTREES 864 ip6_rt_check(&rt->rt6i_src, &fl->fl6_src, np->saddr_cache) || 865 #endif 866 (fl->oif && fl->oif != dst->dev->ifindex)) { 867 dst_release(dst); 868 dst = NULL; 869 } 870 871 out: 872 return dst; 873 } 874 875 static int ip6_dst_lookup_tail(struct sock *sk, 876 struct dst_entry **dst, struct flowi *fl) 877 { 878 int err; 879 880 if (*dst == NULL) 881 *dst = ip6_route_output(sk, fl); 882 883 if ((err = (*dst)->error)) 884 goto out_err_release; 885 886 if (ipv6_addr_any(&fl->fl6_src)) { 887 err = ipv6_get_saddr(*dst, &fl->fl6_dst, &fl->fl6_src); 888 if (err) 889 goto out_err_release; 890 } 891 892 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD 893 /* 894 * Here if the dst entry we've looked up 895 * has a neighbour entry that is in the INCOMPLETE 896 * state and the src address from the flow is 897 * marked as OPTIMISTIC, we release the found 898 * dst entry and replace it instead with the 899 * dst entry of the nexthop router 900 */ 901 if (!((*dst)->neighbour->nud_state & NUD_VALID)) { 902 struct inet6_ifaddr *ifp; 903 struct flowi fl_gw; 904 int redirect; 905 906 ifp = ipv6_get_ifaddr(&fl->fl6_src, (*dst)->dev, 1); 907 908 redirect = (ifp && ifp->flags & IFA_F_OPTIMISTIC); 909 if (ifp) 910 in6_ifa_put(ifp); 911 912 if (redirect) { 913 /* 914 * We need to get the dst entry for the 915 * default router instead 916 */ 917 dst_release(*dst); 918 memcpy(&fl_gw, fl, sizeof(struct flowi)); 919 memset(&fl_gw.fl6_dst, 0, sizeof(struct in6_addr)); 920 *dst = ip6_route_output(sk, &fl_gw); 921 if ((err = (*dst)->error)) 922 goto out_err_release; 923 } 924 } 925 #endif 926 927 return 0; 928 929 out_err_release: 930 dst_release(*dst); 931 *dst = NULL; 932 return err; 933 } 934 935 /** 936 * ip6_dst_lookup - perform route lookup on flow 937 * @sk: socket which provides route info 938 * @dst: pointer to dst_entry * for result 939 * @fl: flow to lookup 940 * 941 * This function performs a route lookup on the given flow. 942 * 943 * It returns zero on success, or a standard errno code on error. 944 */ 945 int ip6_dst_lookup(struct sock *sk, struct dst_entry **dst, struct flowi *fl) 946 { 947 *dst = NULL; 948 return ip6_dst_lookup_tail(sk, dst, fl); 949 } 950 EXPORT_SYMBOL_GPL(ip6_dst_lookup); 951 952 /** 953 * ip6_sk_dst_lookup - perform socket cached route lookup on flow 954 * @sk: socket which provides the dst cache and route info 955 * @dst: pointer to dst_entry * for result 956 * @fl: flow to lookup 957 * 958 * This function performs a route lookup on the given flow with the 959 * possibility of using the cached route in the socket if it is valid. 960 * It will take the socket dst lock when operating on the dst cache. 961 * As a result, this function can only be used in process context. 962 * 963 * It returns zero on success, or a standard errno code on error. 964 */ 965 int ip6_sk_dst_lookup(struct sock *sk, struct dst_entry **dst, struct flowi *fl) 966 { 967 *dst = NULL; 968 if (sk) { 969 *dst = sk_dst_check(sk, inet6_sk(sk)->dst_cookie); 970 *dst = ip6_sk_dst_check(sk, *dst, fl); 971 } 972 973 return ip6_dst_lookup_tail(sk, dst, fl); 974 } 975 EXPORT_SYMBOL_GPL(ip6_sk_dst_lookup); 976 977 static inline int ip6_ufo_append_data(struct sock *sk, 978 int getfrag(void *from, char *to, int offset, int len, 979 int odd, struct sk_buff *skb), 980 void *from, int length, int hh_len, int fragheaderlen, 981 int transhdrlen, int mtu,unsigned int flags) 982 983 { 984 struct sk_buff *skb; 985 int err; 986 987 /* There is support for UDP large send offload by network 988 * device, so create one single skb packet containing complete 989 * udp datagram 990 */ 991 if ((skb = skb_peek_tail(&sk->sk_write_queue)) == NULL) { 992 skb = sock_alloc_send_skb(sk, 993 hh_len + fragheaderlen + transhdrlen + 20, 994 (flags & MSG_DONTWAIT), &err); 995 if (skb == NULL) 996 return -ENOMEM; 997 998 /* reserve space for Hardware header */ 999 skb_reserve(skb, hh_len); 1000 1001 /* create space for UDP/IP header */ 1002 skb_put(skb,fragheaderlen + transhdrlen); 1003 1004 /* initialize network header pointer */ 1005 skb_reset_network_header(skb); 1006 1007 /* initialize protocol header pointer */ 1008 skb->transport_header = skb->network_header + fragheaderlen; 1009 1010 skb->ip_summed = CHECKSUM_PARTIAL; 1011 skb->csum = 0; 1012 sk->sk_sndmsg_off = 0; 1013 } 1014 1015 err = skb_append_datato_frags(sk,skb, getfrag, from, 1016 (length - transhdrlen)); 1017 if (!err) { 1018 struct frag_hdr fhdr; 1019 1020 /* specify the length of each IP datagram fragment*/ 1021 skb_shinfo(skb)->gso_size = mtu - fragheaderlen - 1022 sizeof(struct frag_hdr); 1023 skb_shinfo(skb)->gso_type = SKB_GSO_UDP; 1024 ipv6_select_ident(skb, &fhdr); 1025 skb_shinfo(skb)->ip6_frag_id = fhdr.identification; 1026 __skb_queue_tail(&sk->sk_write_queue, skb); 1027 1028 return 0; 1029 } 1030 /* There is not enough support do UPD LSO, 1031 * so follow normal path 1032 */ 1033 kfree_skb(skb); 1034 1035 return err; 1036 } 1037 1038 int ip6_append_data(struct sock *sk, int getfrag(void *from, char *to, 1039 int offset, int len, int odd, struct sk_buff *skb), 1040 void *from, int length, int transhdrlen, 1041 int hlimit, int tclass, struct ipv6_txoptions *opt, struct flowi *fl, 1042 struct rt6_info *rt, unsigned int flags) 1043 { 1044 struct inet_sock *inet = inet_sk(sk); 1045 struct ipv6_pinfo *np = inet6_sk(sk); 1046 struct sk_buff *skb; 1047 unsigned int maxfraglen, fragheaderlen; 1048 int exthdrlen; 1049 int hh_len; 1050 int mtu; 1051 int copy; 1052 int err; 1053 int offset = 0; 1054 int csummode = CHECKSUM_NONE; 1055 1056 if (flags&MSG_PROBE) 1057 return 0; 1058 if (skb_queue_empty(&sk->sk_write_queue)) { 1059 /* 1060 * setup for corking 1061 */ 1062 if (opt) { 1063 if (np->cork.opt == NULL) { 1064 np->cork.opt = kmalloc(opt->tot_len, 1065 sk->sk_allocation); 1066 if (unlikely(np->cork.opt == NULL)) 1067 return -ENOBUFS; 1068 } else if (np->cork.opt->tot_len < opt->tot_len) { 1069 printk(KERN_DEBUG "ip6_append_data: invalid option length\n"); 1070 return -EINVAL; 1071 } 1072 memcpy(np->cork.opt, opt, opt->tot_len); 1073 inet->cork.flags |= IPCORK_OPT; 1074 /* need source address above miyazawa*/ 1075 } 1076 dst_hold(&rt->u.dst); 1077 np->cork.rt = rt; 1078 inet->cork.fl = *fl; 1079 np->cork.hop_limit = hlimit; 1080 np->cork.tclass = tclass; 1081 mtu = np->pmtudisc == IPV6_PMTUDISC_PROBE ? 1082 rt->u.dst.dev->mtu : dst_mtu(rt->u.dst.path); 1083 if (np->frag_size < mtu) { 1084 if (np->frag_size) 1085 mtu = np->frag_size; 1086 } 1087 inet->cork.fragsize = mtu; 1088 if (dst_allfrag(rt->u.dst.path)) 1089 inet->cork.flags |= IPCORK_ALLFRAG; 1090 inet->cork.length = 0; 1091 sk->sk_sndmsg_page = NULL; 1092 sk->sk_sndmsg_off = 0; 1093 exthdrlen = rt->u.dst.header_len + (opt ? opt->opt_flen : 0); 1094 length += exthdrlen; 1095 transhdrlen += exthdrlen; 1096 } else { 1097 rt = np->cork.rt; 1098 fl = &inet->cork.fl; 1099 if (inet->cork.flags & IPCORK_OPT) 1100 opt = np->cork.opt; 1101 transhdrlen = 0; 1102 exthdrlen = 0; 1103 mtu = inet->cork.fragsize; 1104 } 1105 1106 hh_len = LL_RESERVED_SPACE(rt->u.dst.dev); 1107 1108 fragheaderlen = sizeof(struct ipv6hdr) + rt->u.dst.nfheader_len + (opt ? opt->opt_nflen : 0); 1109 maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen - sizeof(struct frag_hdr); 1110 1111 if (mtu <= sizeof(struct ipv6hdr) + IPV6_MAXPLEN) { 1112 if (inet->cork.length + length > sizeof(struct ipv6hdr) + IPV6_MAXPLEN - fragheaderlen) { 1113 ipv6_local_error(sk, EMSGSIZE, fl, mtu-exthdrlen); 1114 return -EMSGSIZE; 1115 } 1116 } 1117 1118 /* 1119 * Let's try using as much space as possible. 1120 * Use MTU if total length of the message fits into the MTU. 1121 * Otherwise, we need to reserve fragment header and 1122 * fragment alignment (= 8-15 octects, in total). 1123 * 1124 * Note that we may need to "move" the data from the tail of 1125 * of the buffer to the new fragment when we split 1126 * the message. 1127 * 1128 * FIXME: It may be fragmented into multiple chunks 1129 * at once if non-fragmentable extension headers 1130 * are too large. 1131 * --yoshfuji 1132 */ 1133 1134 inet->cork.length += length; 1135 if (((length > mtu) && (sk->sk_protocol == IPPROTO_UDP)) && 1136 (rt->u.dst.dev->features & NETIF_F_UFO)) { 1137 1138 err = ip6_ufo_append_data(sk, getfrag, from, length, hh_len, 1139 fragheaderlen, transhdrlen, mtu, 1140 flags); 1141 if (err) 1142 goto error; 1143 return 0; 1144 } 1145 1146 if ((skb = skb_peek_tail(&sk->sk_write_queue)) == NULL) 1147 goto alloc_new_skb; 1148 1149 while (length > 0) { 1150 /* Check if the remaining data fits into current packet. */ 1151 copy = (inet->cork.length <= mtu && !(inet->cork.flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - skb->len; 1152 if (copy < length) 1153 copy = maxfraglen - skb->len; 1154 1155 if (copy <= 0) { 1156 char *data; 1157 unsigned int datalen; 1158 unsigned int fraglen; 1159 unsigned int fraggap; 1160 unsigned int alloclen; 1161 struct sk_buff *skb_prev; 1162 alloc_new_skb: 1163 skb_prev = skb; 1164 1165 /* There's no room in the current skb */ 1166 if (skb_prev) 1167 fraggap = skb_prev->len - maxfraglen; 1168 else 1169 fraggap = 0; 1170 1171 /* 1172 * If remaining data exceeds the mtu, 1173 * we know we need more fragment(s). 1174 */ 1175 datalen = length + fraggap; 1176 if (datalen > (inet->cork.length <= mtu && !(inet->cork.flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - fragheaderlen) 1177 datalen = maxfraglen - fragheaderlen; 1178 1179 fraglen = datalen + fragheaderlen; 1180 if ((flags & MSG_MORE) && 1181 !(rt->u.dst.dev->features&NETIF_F_SG)) 1182 alloclen = mtu; 1183 else 1184 alloclen = datalen + fragheaderlen; 1185 1186 /* 1187 * The last fragment gets additional space at tail. 1188 * Note: we overallocate on fragments with MSG_MODE 1189 * because we have no idea if we're the last one. 1190 */ 1191 if (datalen == length + fraggap) 1192 alloclen += rt->u.dst.trailer_len; 1193 1194 /* 1195 * We just reserve space for fragment header. 1196 * Note: this may be overallocation if the message 1197 * (without MSG_MORE) fits into the MTU. 1198 */ 1199 alloclen += sizeof(struct frag_hdr); 1200 1201 if (transhdrlen) { 1202 skb = sock_alloc_send_skb(sk, 1203 alloclen + hh_len, 1204 (flags & MSG_DONTWAIT), &err); 1205 } else { 1206 skb = NULL; 1207 if (atomic_read(&sk->sk_wmem_alloc) <= 1208 2 * sk->sk_sndbuf) 1209 skb = sock_wmalloc(sk, 1210 alloclen + hh_len, 1, 1211 sk->sk_allocation); 1212 if (unlikely(skb == NULL)) 1213 err = -ENOBUFS; 1214 } 1215 if (skb == NULL) 1216 goto error; 1217 /* 1218 * Fill in the control structures 1219 */ 1220 skb->ip_summed = csummode; 1221 skb->csum = 0; 1222 /* reserve for fragmentation */ 1223 skb_reserve(skb, hh_len+sizeof(struct frag_hdr)); 1224 1225 /* 1226 * Find where to start putting bytes 1227 */ 1228 data = skb_put(skb, fraglen); 1229 skb_set_network_header(skb, exthdrlen); 1230 data += fragheaderlen; 1231 skb->transport_header = (skb->network_header + 1232 fragheaderlen); 1233 if (fraggap) { 1234 skb->csum = skb_copy_and_csum_bits( 1235 skb_prev, maxfraglen, 1236 data + transhdrlen, fraggap, 0); 1237 skb_prev->csum = csum_sub(skb_prev->csum, 1238 skb->csum); 1239 data += fraggap; 1240 pskb_trim_unique(skb_prev, maxfraglen); 1241 } 1242 copy = datalen - transhdrlen - fraggap; 1243 if (copy < 0) { 1244 err = -EINVAL; 1245 kfree_skb(skb); 1246 goto error; 1247 } else if (copy > 0 && getfrag(from, data + transhdrlen, offset, copy, fraggap, skb) < 0) { 1248 err = -EFAULT; 1249 kfree_skb(skb); 1250 goto error; 1251 } 1252 1253 offset += copy; 1254 length -= datalen - fraggap; 1255 transhdrlen = 0; 1256 exthdrlen = 0; 1257 csummode = CHECKSUM_NONE; 1258 1259 /* 1260 * Put the packet on the pending queue 1261 */ 1262 __skb_queue_tail(&sk->sk_write_queue, skb); 1263 continue; 1264 } 1265 1266 if (copy > length) 1267 copy = length; 1268 1269 if (!(rt->u.dst.dev->features&NETIF_F_SG)) { 1270 unsigned int off; 1271 1272 off = skb->len; 1273 if (getfrag(from, skb_put(skb, copy), 1274 offset, copy, off, skb) < 0) { 1275 __skb_trim(skb, off); 1276 err = -EFAULT; 1277 goto error; 1278 } 1279 } else { 1280 int i = skb_shinfo(skb)->nr_frags; 1281 skb_frag_t *frag = &skb_shinfo(skb)->frags[i-1]; 1282 struct page *page = sk->sk_sndmsg_page; 1283 int off = sk->sk_sndmsg_off; 1284 unsigned int left; 1285 1286 if (page && (left = PAGE_SIZE - off) > 0) { 1287 if (copy >= left) 1288 copy = left; 1289 if (page != frag->page) { 1290 if (i == MAX_SKB_FRAGS) { 1291 err = -EMSGSIZE; 1292 goto error; 1293 } 1294 get_page(page); 1295 skb_fill_page_desc(skb, i, page, sk->sk_sndmsg_off, 0); 1296 frag = &skb_shinfo(skb)->frags[i]; 1297 } 1298 } else if(i < MAX_SKB_FRAGS) { 1299 if (copy > PAGE_SIZE) 1300 copy = PAGE_SIZE; 1301 page = alloc_pages(sk->sk_allocation, 0); 1302 if (page == NULL) { 1303 err = -ENOMEM; 1304 goto error; 1305 } 1306 sk->sk_sndmsg_page = page; 1307 sk->sk_sndmsg_off = 0; 1308 1309 skb_fill_page_desc(skb, i, page, 0, 0); 1310 frag = &skb_shinfo(skb)->frags[i]; 1311 skb->truesize += PAGE_SIZE; 1312 atomic_add(PAGE_SIZE, &sk->sk_wmem_alloc); 1313 } else { 1314 err = -EMSGSIZE; 1315 goto error; 1316 } 1317 if (getfrag(from, page_address(frag->page)+frag->page_offset+frag->size, offset, copy, skb->len, skb) < 0) { 1318 err = -EFAULT; 1319 goto error; 1320 } 1321 sk->sk_sndmsg_off += copy; 1322 frag->size += copy; 1323 skb->len += copy; 1324 skb->data_len += copy; 1325 } 1326 offset += copy; 1327 length -= copy; 1328 } 1329 return 0; 1330 error: 1331 inet->cork.length -= length; 1332 IP6_INC_STATS(rt->rt6i_idev, IPSTATS_MIB_OUTDISCARDS); 1333 return err; 1334 } 1335 1336 int ip6_push_pending_frames(struct sock *sk) 1337 { 1338 struct sk_buff *skb, *tmp_skb; 1339 struct sk_buff **tail_skb; 1340 struct in6_addr final_dst_buf, *final_dst = &final_dst_buf; 1341 struct inet_sock *inet = inet_sk(sk); 1342 struct ipv6_pinfo *np = inet6_sk(sk); 1343 struct ipv6hdr *hdr; 1344 struct ipv6_txoptions *opt = np->cork.opt; 1345 struct rt6_info *rt = np->cork.rt; 1346 struct flowi *fl = &inet->cork.fl; 1347 unsigned char proto = fl->proto; 1348 int err = 0; 1349 1350 if ((skb = __skb_dequeue(&sk->sk_write_queue)) == NULL) 1351 goto out; 1352 tail_skb = &(skb_shinfo(skb)->frag_list); 1353 1354 /* move skb->data to ip header from ext header */ 1355 if (skb->data < skb_network_header(skb)) 1356 __skb_pull(skb, skb_network_offset(skb)); 1357 while ((tmp_skb = __skb_dequeue(&sk->sk_write_queue)) != NULL) { 1358 __skb_pull(tmp_skb, skb_network_header_len(skb)); 1359 *tail_skb = tmp_skb; 1360 tail_skb = &(tmp_skb->next); 1361 skb->len += tmp_skb->len; 1362 skb->data_len += tmp_skb->len; 1363 skb->truesize += tmp_skb->truesize; 1364 __sock_put(tmp_skb->sk); 1365 tmp_skb->destructor = NULL; 1366 tmp_skb->sk = NULL; 1367 } 1368 1369 ipv6_addr_copy(final_dst, &fl->fl6_dst); 1370 __skb_pull(skb, skb_network_header_len(skb)); 1371 if (opt && opt->opt_flen) 1372 ipv6_push_frag_opts(skb, opt, &proto); 1373 if (opt && opt->opt_nflen) 1374 ipv6_push_nfrag_opts(skb, opt, &proto, &final_dst); 1375 1376 skb_push(skb, sizeof(struct ipv6hdr)); 1377 skb_reset_network_header(skb); 1378 hdr = ipv6_hdr(skb); 1379 1380 *(__be32*)hdr = fl->fl6_flowlabel | 1381 htonl(0x60000000 | ((int)np->cork.tclass << 20)); 1382 1383 if (skb->len <= sizeof(struct ipv6hdr) + IPV6_MAXPLEN) 1384 hdr->payload_len = htons(skb->len - sizeof(struct ipv6hdr)); 1385 else 1386 hdr->payload_len = 0; 1387 hdr->hop_limit = np->cork.hop_limit; 1388 hdr->nexthdr = proto; 1389 ipv6_addr_copy(&hdr->saddr, &fl->fl6_src); 1390 ipv6_addr_copy(&hdr->daddr, final_dst); 1391 1392 skb->priority = sk->sk_priority; 1393 1394 skb->dst = dst_clone(&rt->u.dst); 1395 IP6_INC_STATS(rt->rt6i_idev, IPSTATS_MIB_OUTREQUESTS); 1396 err = NF_HOOK(PF_INET6, NF_IP6_LOCAL_OUT, skb, NULL, skb->dst->dev, dst_output); 1397 if (err) { 1398 if (err > 0) 1399 err = np->recverr ? net_xmit_errno(err) : 0; 1400 if (err) 1401 goto error; 1402 } 1403 1404 out: 1405 inet->cork.flags &= ~IPCORK_OPT; 1406 kfree(np->cork.opt); 1407 np->cork.opt = NULL; 1408 if (np->cork.rt) { 1409 dst_release(&np->cork.rt->u.dst); 1410 np->cork.rt = NULL; 1411 inet->cork.flags &= ~IPCORK_ALLFRAG; 1412 } 1413 memset(&inet->cork.fl, 0, sizeof(inet->cork.fl)); 1414 return err; 1415 error: 1416 goto out; 1417 } 1418 1419 void ip6_flush_pending_frames(struct sock *sk) 1420 { 1421 struct inet_sock *inet = inet_sk(sk); 1422 struct ipv6_pinfo *np = inet6_sk(sk); 1423 struct sk_buff *skb; 1424 1425 while ((skb = __skb_dequeue_tail(&sk->sk_write_queue)) != NULL) { 1426 IP6_INC_STATS(ip6_dst_idev(skb->dst), 1427 IPSTATS_MIB_OUTDISCARDS); 1428 kfree_skb(skb); 1429 } 1430 1431 inet->cork.flags &= ~IPCORK_OPT; 1432 1433 kfree(np->cork.opt); 1434 np->cork.opt = NULL; 1435 if (np->cork.rt) { 1436 dst_release(&np->cork.rt->u.dst); 1437 np->cork.rt = NULL; 1438 inet->cork.flags &= ~IPCORK_ALLFRAG; 1439 } 1440 memset(&inet->cork.fl, 0, sizeof(inet->cork.fl)); 1441 } 1442