1 /* 2 * IPv6 output functions 3 * Linux INET6 implementation 4 * 5 * Authors: 6 * Pedro Roque <roque@di.fc.ul.pt> 7 * 8 * Based on linux/net/ipv4/ip_output.c 9 * 10 * This program is free software; you can redistribute it and/or 11 * modify it under the terms of the GNU General Public License 12 * as published by the Free Software Foundation; either version 13 * 2 of the License, or (at your option) any later version. 14 * 15 * Changes: 16 * A.N.Kuznetsov : airthmetics in fragmentation. 17 * extension headers are implemented. 18 * route changes now work. 19 * ip6_forward does not confuse sniffers. 20 * etc. 21 * 22 * H. von Brand : Added missing #include <linux/string.h> 23 * Imran Patel : frag id should be in NBO 24 * Kazunori MIYAZAWA @USAGI 25 * : add ip6_append_data and related functions 26 * for datagram xmit 27 */ 28 29 #include <linux/errno.h> 30 #include <linux/kernel.h> 31 #include <linux/string.h> 32 #include <linux/socket.h> 33 #include <linux/net.h> 34 #include <linux/netdevice.h> 35 #include <linux/if_arp.h> 36 #include <linux/in6.h> 37 #include <linux/tcp.h> 38 #include <linux/route.h> 39 #include <linux/module.h> 40 #include <linux/slab.h> 41 42 #include <linux/netfilter.h> 43 #include <linux/netfilter_ipv6.h> 44 45 #include <net/sock.h> 46 #include <net/snmp.h> 47 48 #include <net/ipv6.h> 49 #include <net/ndisc.h> 50 #include <net/protocol.h> 51 #include <net/ip6_route.h> 52 #include <net/addrconf.h> 53 #include <net/rawv6.h> 54 #include <net/icmp.h> 55 #include <net/xfrm.h> 56 #include <net/checksum.h> 57 #include <linux/mroute6.h> 58 59 static int ip6_fragment(struct sk_buff *skb, int (*output)(struct sk_buff *)); 60 61 int __ip6_local_out(struct sk_buff *skb) 62 { 63 int len; 64 65 len = skb->len - sizeof(struct ipv6hdr); 66 if (len > IPV6_MAXPLEN) 67 len = 0; 68 ipv6_hdr(skb)->payload_len = htons(len); 69 70 return nf_hook(NFPROTO_IPV6, NF_INET_LOCAL_OUT, skb, NULL, 71 skb_dst(skb)->dev, dst_output); 72 } 73 74 int ip6_local_out(struct sk_buff *skb) 75 { 76 int err; 77 78 err = __ip6_local_out(skb); 79 if (likely(err == 1)) 80 err = dst_output(skb); 81 82 return err; 83 } 84 EXPORT_SYMBOL_GPL(ip6_local_out); 85 86 /* dev_loopback_xmit for use with netfilter. */ 87 static int ip6_dev_loopback_xmit(struct sk_buff *newskb) 88 { 89 skb_reset_mac_header(newskb); 90 __skb_pull(newskb, skb_network_offset(newskb)); 91 newskb->pkt_type = PACKET_LOOPBACK; 92 newskb->ip_summed = CHECKSUM_UNNECESSARY; 93 WARN_ON(!skb_dst(newskb)); 94 95 netif_rx_ni(newskb); 96 return 0; 97 } 98 99 static int ip6_finish_output2(struct sk_buff *skb) 100 { 101 struct dst_entry *dst = skb_dst(skb); 102 struct net_device *dev = dst->dev; 103 104 skb->protocol = htons(ETH_P_IPV6); 105 skb->dev = dev; 106 107 if (ipv6_addr_is_multicast(&ipv6_hdr(skb)->daddr)) { 108 struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb)); 109 110 if (!(dev->flags & IFF_LOOPBACK) && sk_mc_loop(skb->sk) && 111 ((mroute6_socket(dev_net(dev), skb) && 112 !(IP6CB(skb)->flags & IP6SKB_FORWARDED)) || 113 ipv6_chk_mcast_addr(dev, &ipv6_hdr(skb)->daddr, 114 &ipv6_hdr(skb)->saddr))) { 115 struct sk_buff *newskb = skb_clone(skb, GFP_ATOMIC); 116 117 /* Do not check for IFF_ALLMULTI; multicast routing 118 is not supported in any case. 119 */ 120 if (newskb) 121 NF_HOOK(NFPROTO_IPV6, NF_INET_POST_ROUTING, 122 newskb, NULL, newskb->dev, 123 ip6_dev_loopback_xmit); 124 125 if (ipv6_hdr(skb)->hop_limit == 0) { 126 IP6_INC_STATS(dev_net(dev), idev, 127 IPSTATS_MIB_OUTDISCARDS); 128 kfree_skb(skb); 129 return 0; 130 } 131 } 132 133 IP6_UPD_PO_STATS(dev_net(dev), idev, IPSTATS_MIB_OUTMCAST, 134 skb->len); 135 } 136 137 if (dst->hh) 138 return neigh_hh_output(dst->hh, skb); 139 else if (dst->neighbour) 140 return dst->neighbour->output(skb); 141 142 IP6_INC_STATS_BH(dev_net(dst->dev), 143 ip6_dst_idev(dst), IPSTATS_MIB_OUTNOROUTES); 144 kfree_skb(skb); 145 return -EINVAL; 146 } 147 148 static inline int ip6_skb_dst_mtu(struct sk_buff *skb) 149 { 150 struct ipv6_pinfo *np = skb->sk ? inet6_sk(skb->sk) : NULL; 151 152 return (np && np->pmtudisc == IPV6_PMTUDISC_PROBE) ? 153 skb_dst(skb)->dev->mtu : dst_mtu(skb_dst(skb)); 154 } 155 156 static int ip6_finish_output(struct sk_buff *skb) 157 { 158 if ((skb->len > ip6_skb_dst_mtu(skb) && !skb_is_gso(skb)) || 159 dst_allfrag(skb_dst(skb))) 160 return ip6_fragment(skb, ip6_finish_output2); 161 else 162 return ip6_finish_output2(skb); 163 } 164 165 int ip6_output(struct sk_buff *skb) 166 { 167 struct net_device *dev = skb_dst(skb)->dev; 168 struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb)); 169 if (unlikely(idev->cnf.disable_ipv6)) { 170 IP6_INC_STATS(dev_net(dev), idev, 171 IPSTATS_MIB_OUTDISCARDS); 172 kfree_skb(skb); 173 return 0; 174 } 175 176 return NF_HOOK_COND(NFPROTO_IPV6, NF_INET_POST_ROUTING, skb, NULL, dev, 177 ip6_finish_output, 178 !(IP6CB(skb)->flags & IP6SKB_REROUTED)); 179 } 180 181 /* 182 * xmit an sk_buff (used by TCP, SCTP and DCCP) 183 */ 184 185 int ip6_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl, 186 struct ipv6_txoptions *opt) 187 { 188 struct net *net = sock_net(sk); 189 struct ipv6_pinfo *np = inet6_sk(sk); 190 struct in6_addr *first_hop = &fl->fl6_dst; 191 struct dst_entry *dst = skb_dst(skb); 192 struct ipv6hdr *hdr; 193 u8 proto = fl->proto; 194 int seg_len = skb->len; 195 int hlimit = -1; 196 int tclass = 0; 197 u32 mtu; 198 199 if (opt) { 200 unsigned int head_room; 201 202 /* First: exthdrs may take lots of space (~8K for now) 203 MAX_HEADER is not enough. 204 */ 205 head_room = opt->opt_nflen + opt->opt_flen; 206 seg_len += head_room; 207 head_room += sizeof(struct ipv6hdr) + LL_RESERVED_SPACE(dst->dev); 208 209 if (skb_headroom(skb) < head_room) { 210 struct sk_buff *skb2 = skb_realloc_headroom(skb, head_room); 211 if (skb2 == NULL) { 212 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), 213 IPSTATS_MIB_OUTDISCARDS); 214 kfree_skb(skb); 215 return -ENOBUFS; 216 } 217 kfree_skb(skb); 218 skb = skb2; 219 skb_set_owner_w(skb, sk); 220 } 221 if (opt->opt_flen) 222 ipv6_push_frag_opts(skb, opt, &proto); 223 if (opt->opt_nflen) 224 ipv6_push_nfrag_opts(skb, opt, &proto, &first_hop); 225 } 226 227 skb_push(skb, sizeof(struct ipv6hdr)); 228 skb_reset_network_header(skb); 229 hdr = ipv6_hdr(skb); 230 231 /* 232 * Fill in the IPv6 header 233 */ 234 if (np) { 235 tclass = np->tclass; 236 hlimit = np->hop_limit; 237 } 238 if (hlimit < 0) 239 hlimit = ip6_dst_hoplimit(dst); 240 241 *(__be32 *)hdr = htonl(0x60000000 | (tclass << 20)) | fl->fl6_flowlabel; 242 243 hdr->payload_len = htons(seg_len); 244 hdr->nexthdr = proto; 245 hdr->hop_limit = hlimit; 246 247 ipv6_addr_copy(&hdr->saddr, &fl->fl6_src); 248 ipv6_addr_copy(&hdr->daddr, first_hop); 249 250 skb->priority = sk->sk_priority; 251 skb->mark = sk->sk_mark; 252 253 mtu = dst_mtu(dst); 254 if ((skb->len <= mtu) || skb->local_df || skb_is_gso(skb)) { 255 IP6_UPD_PO_STATS(net, ip6_dst_idev(skb_dst(skb)), 256 IPSTATS_MIB_OUT, skb->len); 257 return NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT, skb, NULL, 258 dst->dev, dst_output); 259 } 260 261 if (net_ratelimit()) 262 printk(KERN_DEBUG "IPv6: sending pkt_too_big to self\n"); 263 skb->dev = dst->dev; 264 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu); 265 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_FRAGFAILS); 266 kfree_skb(skb); 267 return -EMSGSIZE; 268 } 269 270 EXPORT_SYMBOL(ip6_xmit); 271 272 /* 273 * To avoid extra problems ND packets are send through this 274 * routine. It's code duplication but I really want to avoid 275 * extra checks since ipv6_build_header is used by TCP (which 276 * is for us performance critical) 277 */ 278 279 int ip6_nd_hdr(struct sock *sk, struct sk_buff *skb, struct net_device *dev, 280 const struct in6_addr *saddr, const struct in6_addr *daddr, 281 int proto, int len) 282 { 283 struct ipv6_pinfo *np = inet6_sk(sk); 284 struct ipv6hdr *hdr; 285 int totlen; 286 287 skb->protocol = htons(ETH_P_IPV6); 288 skb->dev = dev; 289 290 totlen = len + sizeof(struct ipv6hdr); 291 292 skb_reset_network_header(skb); 293 skb_put(skb, sizeof(struct ipv6hdr)); 294 hdr = ipv6_hdr(skb); 295 296 *(__be32*)hdr = htonl(0x60000000); 297 298 hdr->payload_len = htons(len); 299 hdr->nexthdr = proto; 300 hdr->hop_limit = np->hop_limit; 301 302 ipv6_addr_copy(&hdr->saddr, saddr); 303 ipv6_addr_copy(&hdr->daddr, daddr); 304 305 return 0; 306 } 307 308 static int ip6_call_ra_chain(struct sk_buff *skb, int sel) 309 { 310 struct ip6_ra_chain *ra; 311 struct sock *last = NULL; 312 313 read_lock(&ip6_ra_lock); 314 for (ra = ip6_ra_chain; ra; ra = ra->next) { 315 struct sock *sk = ra->sk; 316 if (sk && ra->sel == sel && 317 (!sk->sk_bound_dev_if || 318 sk->sk_bound_dev_if == skb->dev->ifindex)) { 319 if (last) { 320 struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC); 321 if (skb2) 322 rawv6_rcv(last, skb2); 323 } 324 last = sk; 325 } 326 } 327 328 if (last) { 329 rawv6_rcv(last, skb); 330 read_unlock(&ip6_ra_lock); 331 return 1; 332 } 333 read_unlock(&ip6_ra_lock); 334 return 0; 335 } 336 337 static int ip6_forward_proxy_check(struct sk_buff *skb) 338 { 339 struct ipv6hdr *hdr = ipv6_hdr(skb); 340 u8 nexthdr = hdr->nexthdr; 341 int offset; 342 343 if (ipv6_ext_hdr(nexthdr)) { 344 offset = ipv6_skip_exthdr(skb, sizeof(*hdr), &nexthdr); 345 if (offset < 0) 346 return 0; 347 } else 348 offset = sizeof(struct ipv6hdr); 349 350 if (nexthdr == IPPROTO_ICMPV6) { 351 struct icmp6hdr *icmp6; 352 353 if (!pskb_may_pull(skb, (skb_network_header(skb) + 354 offset + 1 - skb->data))) 355 return 0; 356 357 icmp6 = (struct icmp6hdr *)(skb_network_header(skb) + offset); 358 359 switch (icmp6->icmp6_type) { 360 case NDISC_ROUTER_SOLICITATION: 361 case NDISC_ROUTER_ADVERTISEMENT: 362 case NDISC_NEIGHBOUR_SOLICITATION: 363 case NDISC_NEIGHBOUR_ADVERTISEMENT: 364 case NDISC_REDIRECT: 365 /* For reaction involving unicast neighbor discovery 366 * message destined to the proxied address, pass it to 367 * input function. 368 */ 369 return 1; 370 default: 371 break; 372 } 373 } 374 375 /* 376 * The proxying router can't forward traffic sent to a link-local 377 * address, so signal the sender and discard the packet. This 378 * behavior is clarified by the MIPv6 specification. 379 */ 380 if (ipv6_addr_type(&hdr->daddr) & IPV6_ADDR_LINKLOCAL) { 381 dst_link_failure(skb); 382 return -1; 383 } 384 385 return 0; 386 } 387 388 static inline int ip6_forward_finish(struct sk_buff *skb) 389 { 390 return dst_output(skb); 391 } 392 393 int ip6_forward(struct sk_buff *skb) 394 { 395 struct dst_entry *dst = skb_dst(skb); 396 struct ipv6hdr *hdr = ipv6_hdr(skb); 397 struct inet6_skb_parm *opt = IP6CB(skb); 398 struct net *net = dev_net(dst->dev); 399 u32 mtu; 400 401 if (net->ipv6.devconf_all->forwarding == 0) 402 goto error; 403 404 if (skb_warn_if_lro(skb)) 405 goto drop; 406 407 if (!xfrm6_policy_check(NULL, XFRM_POLICY_FWD, skb)) { 408 IP6_INC_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_INDISCARDS); 409 goto drop; 410 } 411 412 skb_forward_csum(skb); 413 414 /* 415 * We DO NOT make any processing on 416 * RA packets, pushing them to user level AS IS 417 * without ane WARRANTY that application will be able 418 * to interpret them. The reason is that we 419 * cannot make anything clever here. 420 * 421 * We are not end-node, so that if packet contains 422 * AH/ESP, we cannot make anything. 423 * Defragmentation also would be mistake, RA packets 424 * cannot be fragmented, because there is no warranty 425 * that different fragments will go along one path. --ANK 426 */ 427 if (opt->ra) { 428 u8 *ptr = skb_network_header(skb) + opt->ra; 429 if (ip6_call_ra_chain(skb, (ptr[2]<<8) + ptr[3])) 430 return 0; 431 } 432 433 /* 434 * check and decrement ttl 435 */ 436 if (hdr->hop_limit <= 1) { 437 /* Force OUTPUT device used as source address */ 438 skb->dev = dst->dev; 439 icmpv6_send(skb, ICMPV6_TIME_EXCEED, ICMPV6_EXC_HOPLIMIT, 0); 440 IP6_INC_STATS_BH(net, 441 ip6_dst_idev(dst), IPSTATS_MIB_INHDRERRORS); 442 443 kfree_skb(skb); 444 return -ETIMEDOUT; 445 } 446 447 /* XXX: idev->cnf.proxy_ndp? */ 448 if (net->ipv6.devconf_all->proxy_ndp && 449 pneigh_lookup(&nd_tbl, net, &hdr->daddr, skb->dev, 0)) { 450 int proxied = ip6_forward_proxy_check(skb); 451 if (proxied > 0) 452 return ip6_input(skb); 453 else if (proxied < 0) { 454 IP6_INC_STATS(net, ip6_dst_idev(dst), 455 IPSTATS_MIB_INDISCARDS); 456 goto drop; 457 } 458 } 459 460 if (!xfrm6_route_forward(skb)) { 461 IP6_INC_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_INDISCARDS); 462 goto drop; 463 } 464 dst = skb_dst(skb); 465 466 /* IPv6 specs say nothing about it, but it is clear that we cannot 467 send redirects to source routed frames. 468 We don't send redirects to frames decapsulated from IPsec. 469 */ 470 if (skb->dev == dst->dev && dst->neighbour && opt->srcrt == 0 && 471 !skb_sec_path(skb)) { 472 struct in6_addr *target = NULL; 473 struct rt6_info *rt; 474 struct neighbour *n = dst->neighbour; 475 476 /* 477 * incoming and outgoing devices are the same 478 * send a redirect. 479 */ 480 481 rt = (struct rt6_info *) dst; 482 if ((rt->rt6i_flags & RTF_GATEWAY)) 483 target = (struct in6_addr*)&n->primary_key; 484 else 485 target = &hdr->daddr; 486 487 /* Limit redirects both by destination (here) 488 and by source (inside ndisc_send_redirect) 489 */ 490 if (xrlim_allow(dst, 1*HZ)) 491 ndisc_send_redirect(skb, n, target); 492 } else { 493 int addrtype = ipv6_addr_type(&hdr->saddr); 494 495 /* This check is security critical. */ 496 if (addrtype == IPV6_ADDR_ANY || 497 addrtype & (IPV6_ADDR_MULTICAST | IPV6_ADDR_LOOPBACK)) 498 goto error; 499 if (addrtype & IPV6_ADDR_LINKLOCAL) { 500 icmpv6_send(skb, ICMPV6_DEST_UNREACH, 501 ICMPV6_NOT_NEIGHBOUR, 0); 502 goto error; 503 } 504 } 505 506 mtu = dst_mtu(dst); 507 if (mtu < IPV6_MIN_MTU) 508 mtu = IPV6_MIN_MTU; 509 510 if (skb->len > mtu && !skb_is_gso(skb)) { 511 /* Again, force OUTPUT device used as source address */ 512 skb->dev = dst->dev; 513 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu); 514 IP6_INC_STATS_BH(net, 515 ip6_dst_idev(dst), IPSTATS_MIB_INTOOBIGERRORS); 516 IP6_INC_STATS_BH(net, 517 ip6_dst_idev(dst), IPSTATS_MIB_FRAGFAILS); 518 kfree_skb(skb); 519 return -EMSGSIZE; 520 } 521 522 if (skb_cow(skb, dst->dev->hard_header_len)) { 523 IP6_INC_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTDISCARDS); 524 goto drop; 525 } 526 527 hdr = ipv6_hdr(skb); 528 529 /* Mangling hops number delayed to point after skb COW */ 530 531 hdr->hop_limit--; 532 533 IP6_INC_STATS_BH(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTFORWDATAGRAMS); 534 return NF_HOOK(NFPROTO_IPV6, NF_INET_FORWARD, skb, skb->dev, dst->dev, 535 ip6_forward_finish); 536 537 error: 538 IP6_INC_STATS_BH(net, ip6_dst_idev(dst), IPSTATS_MIB_INADDRERRORS); 539 drop: 540 kfree_skb(skb); 541 return -EINVAL; 542 } 543 544 static void ip6_copy_metadata(struct sk_buff *to, struct sk_buff *from) 545 { 546 to->pkt_type = from->pkt_type; 547 to->priority = from->priority; 548 to->protocol = from->protocol; 549 skb_dst_drop(to); 550 skb_dst_set(to, dst_clone(skb_dst(from))); 551 to->dev = from->dev; 552 to->mark = from->mark; 553 554 #ifdef CONFIG_NET_SCHED 555 to->tc_index = from->tc_index; 556 #endif 557 nf_copy(to, from); 558 #if defined(CONFIG_NETFILTER_XT_TARGET_TRACE) || \ 559 defined(CONFIG_NETFILTER_XT_TARGET_TRACE_MODULE) 560 to->nf_trace = from->nf_trace; 561 #endif 562 skb_copy_secmark(to, from); 563 } 564 565 int ip6_find_1stfragopt(struct sk_buff *skb, u8 **nexthdr) 566 { 567 u16 offset = sizeof(struct ipv6hdr); 568 struct ipv6_opt_hdr *exthdr = 569 (struct ipv6_opt_hdr *)(ipv6_hdr(skb) + 1); 570 unsigned int packet_len = skb->tail - skb->network_header; 571 int found_rhdr = 0; 572 *nexthdr = &ipv6_hdr(skb)->nexthdr; 573 574 while (offset + 1 <= packet_len) { 575 576 switch (**nexthdr) { 577 578 case NEXTHDR_HOP: 579 break; 580 case NEXTHDR_ROUTING: 581 found_rhdr = 1; 582 break; 583 case NEXTHDR_DEST: 584 #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE) 585 if (ipv6_find_tlv(skb, offset, IPV6_TLV_HAO) >= 0) 586 break; 587 #endif 588 if (found_rhdr) 589 return offset; 590 break; 591 default : 592 return offset; 593 } 594 595 offset += ipv6_optlen(exthdr); 596 *nexthdr = &exthdr->nexthdr; 597 exthdr = (struct ipv6_opt_hdr *)(skb_network_header(skb) + 598 offset); 599 } 600 601 return offset; 602 } 603 604 static int ip6_fragment(struct sk_buff *skb, int (*output)(struct sk_buff *)) 605 { 606 struct sk_buff *frag; 607 struct rt6_info *rt = (struct rt6_info*)skb_dst(skb); 608 struct ipv6_pinfo *np = skb->sk ? inet6_sk(skb->sk) : NULL; 609 struct ipv6hdr *tmp_hdr; 610 struct frag_hdr *fh; 611 unsigned int mtu, hlen, left, len; 612 __be32 frag_id = 0; 613 int ptr, offset = 0, err=0; 614 u8 *prevhdr, nexthdr = 0; 615 struct net *net = dev_net(skb_dst(skb)->dev); 616 617 hlen = ip6_find_1stfragopt(skb, &prevhdr); 618 nexthdr = *prevhdr; 619 620 mtu = ip6_skb_dst_mtu(skb); 621 622 /* We must not fragment if the socket is set to force MTU discovery 623 * or if the skb it not generated by a local socket. 624 */ 625 if (!skb->local_df && skb->len > mtu) { 626 skb->dev = skb_dst(skb)->dev; 627 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu); 628 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), 629 IPSTATS_MIB_FRAGFAILS); 630 kfree_skb(skb); 631 return -EMSGSIZE; 632 } 633 634 if (np && np->frag_size < mtu) { 635 if (np->frag_size) 636 mtu = np->frag_size; 637 } 638 mtu -= hlen + sizeof(struct frag_hdr); 639 640 if (skb_has_frags(skb)) { 641 int first_len = skb_pagelen(skb); 642 int truesizes = 0; 643 644 if (first_len - hlen > mtu || 645 ((first_len - hlen) & 7) || 646 skb_cloned(skb)) 647 goto slow_path; 648 649 skb_walk_frags(skb, frag) { 650 /* Correct geometry. */ 651 if (frag->len > mtu || 652 ((frag->len & 7) && frag->next) || 653 skb_headroom(frag) < hlen) 654 goto slow_path; 655 656 /* Partially cloned skb? */ 657 if (skb_shared(frag)) 658 goto slow_path; 659 660 BUG_ON(frag->sk); 661 if (skb->sk) { 662 frag->sk = skb->sk; 663 frag->destructor = sock_wfree; 664 truesizes += frag->truesize; 665 } 666 } 667 668 err = 0; 669 offset = 0; 670 frag = skb_shinfo(skb)->frag_list; 671 skb_frag_list_init(skb); 672 /* BUILD HEADER */ 673 674 *prevhdr = NEXTHDR_FRAGMENT; 675 tmp_hdr = kmemdup(skb_network_header(skb), hlen, GFP_ATOMIC); 676 if (!tmp_hdr) { 677 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), 678 IPSTATS_MIB_FRAGFAILS); 679 return -ENOMEM; 680 } 681 682 __skb_pull(skb, hlen); 683 fh = (struct frag_hdr*)__skb_push(skb, sizeof(struct frag_hdr)); 684 __skb_push(skb, hlen); 685 skb_reset_network_header(skb); 686 memcpy(skb_network_header(skb), tmp_hdr, hlen); 687 688 ipv6_select_ident(fh); 689 fh->nexthdr = nexthdr; 690 fh->reserved = 0; 691 fh->frag_off = htons(IP6_MF); 692 frag_id = fh->identification; 693 694 first_len = skb_pagelen(skb); 695 skb->data_len = first_len - skb_headlen(skb); 696 skb->truesize -= truesizes; 697 skb->len = first_len; 698 ipv6_hdr(skb)->payload_len = htons(first_len - 699 sizeof(struct ipv6hdr)); 700 701 dst_hold(&rt->u.dst); 702 703 for (;;) { 704 /* Prepare header of the next frame, 705 * before previous one went down. */ 706 if (frag) { 707 frag->ip_summed = CHECKSUM_NONE; 708 skb_reset_transport_header(frag); 709 fh = (struct frag_hdr*)__skb_push(frag, sizeof(struct frag_hdr)); 710 __skb_push(frag, hlen); 711 skb_reset_network_header(frag); 712 memcpy(skb_network_header(frag), tmp_hdr, 713 hlen); 714 offset += skb->len - hlen - sizeof(struct frag_hdr); 715 fh->nexthdr = nexthdr; 716 fh->reserved = 0; 717 fh->frag_off = htons(offset); 718 if (frag->next != NULL) 719 fh->frag_off |= htons(IP6_MF); 720 fh->identification = frag_id; 721 ipv6_hdr(frag)->payload_len = 722 htons(frag->len - 723 sizeof(struct ipv6hdr)); 724 ip6_copy_metadata(frag, skb); 725 } 726 727 err = output(skb); 728 if(!err) 729 IP6_INC_STATS(net, ip6_dst_idev(&rt->u.dst), 730 IPSTATS_MIB_FRAGCREATES); 731 732 if (err || !frag) 733 break; 734 735 skb = frag; 736 frag = skb->next; 737 skb->next = NULL; 738 } 739 740 kfree(tmp_hdr); 741 742 if (err == 0) { 743 IP6_INC_STATS(net, ip6_dst_idev(&rt->u.dst), 744 IPSTATS_MIB_FRAGOKS); 745 dst_release(&rt->u.dst); 746 return 0; 747 } 748 749 while (frag) { 750 skb = frag->next; 751 kfree_skb(frag); 752 frag = skb; 753 } 754 755 IP6_INC_STATS(net, ip6_dst_idev(&rt->u.dst), 756 IPSTATS_MIB_FRAGFAILS); 757 dst_release(&rt->u.dst); 758 return err; 759 } 760 761 slow_path: 762 left = skb->len - hlen; /* Space per frame */ 763 ptr = hlen; /* Where to start from */ 764 765 /* 766 * Fragment the datagram. 767 */ 768 769 *prevhdr = NEXTHDR_FRAGMENT; 770 771 /* 772 * Keep copying data until we run out. 773 */ 774 while(left > 0) { 775 len = left; 776 /* IF: it doesn't fit, use 'mtu' - the data space left */ 777 if (len > mtu) 778 len = mtu; 779 /* IF: we are not sending upto and including the packet end 780 then align the next start on an eight byte boundary */ 781 if (len < left) { 782 len &= ~7; 783 } 784 /* 785 * Allocate buffer. 786 */ 787 788 if ((frag = alloc_skb(len+hlen+sizeof(struct frag_hdr)+LL_ALLOCATED_SPACE(rt->u.dst.dev), GFP_ATOMIC)) == NULL) { 789 NETDEBUG(KERN_INFO "IPv6: frag: no memory for new fragment!\n"); 790 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), 791 IPSTATS_MIB_FRAGFAILS); 792 err = -ENOMEM; 793 goto fail; 794 } 795 796 /* 797 * Set up data on packet 798 */ 799 800 ip6_copy_metadata(frag, skb); 801 skb_reserve(frag, LL_RESERVED_SPACE(rt->u.dst.dev)); 802 skb_put(frag, len + hlen + sizeof(struct frag_hdr)); 803 skb_reset_network_header(frag); 804 fh = (struct frag_hdr *)(skb_network_header(frag) + hlen); 805 frag->transport_header = (frag->network_header + hlen + 806 sizeof(struct frag_hdr)); 807 808 /* 809 * Charge the memory for the fragment to any owner 810 * it might possess 811 */ 812 if (skb->sk) 813 skb_set_owner_w(frag, skb->sk); 814 815 /* 816 * Copy the packet header into the new buffer. 817 */ 818 skb_copy_from_linear_data(skb, skb_network_header(frag), hlen); 819 820 /* 821 * Build fragment header. 822 */ 823 fh->nexthdr = nexthdr; 824 fh->reserved = 0; 825 if (!frag_id) { 826 ipv6_select_ident(fh); 827 frag_id = fh->identification; 828 } else 829 fh->identification = frag_id; 830 831 /* 832 * Copy a block of the IP datagram. 833 */ 834 if (skb_copy_bits(skb, ptr, skb_transport_header(frag), len)) 835 BUG(); 836 left -= len; 837 838 fh->frag_off = htons(offset); 839 if (left > 0) 840 fh->frag_off |= htons(IP6_MF); 841 ipv6_hdr(frag)->payload_len = htons(frag->len - 842 sizeof(struct ipv6hdr)); 843 844 ptr += len; 845 offset += len; 846 847 /* 848 * Put this fragment into the sending queue. 849 */ 850 err = output(frag); 851 if (err) 852 goto fail; 853 854 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), 855 IPSTATS_MIB_FRAGCREATES); 856 } 857 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), 858 IPSTATS_MIB_FRAGOKS); 859 kfree_skb(skb); 860 return err; 861 862 fail: 863 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), 864 IPSTATS_MIB_FRAGFAILS); 865 kfree_skb(skb); 866 return err; 867 } 868 869 static inline int ip6_rt_check(struct rt6key *rt_key, 870 struct in6_addr *fl_addr, 871 struct in6_addr *addr_cache) 872 { 873 return ((rt_key->plen != 128 || !ipv6_addr_equal(fl_addr, &rt_key->addr)) && 874 (addr_cache == NULL || !ipv6_addr_equal(fl_addr, addr_cache))); 875 } 876 877 static struct dst_entry *ip6_sk_dst_check(struct sock *sk, 878 struct dst_entry *dst, 879 struct flowi *fl) 880 { 881 struct ipv6_pinfo *np = inet6_sk(sk); 882 struct rt6_info *rt = (struct rt6_info *)dst; 883 884 if (!dst) 885 goto out; 886 887 /* Yes, checking route validity in not connected 888 * case is not very simple. Take into account, 889 * that we do not support routing by source, TOS, 890 * and MSG_DONTROUTE --ANK (980726) 891 * 892 * 1. ip6_rt_check(): If route was host route, 893 * check that cached destination is current. 894 * If it is network route, we still may 895 * check its validity using saved pointer 896 * to the last used address: daddr_cache. 897 * We do not want to save whole address now, 898 * (because main consumer of this service 899 * is tcp, which has not this problem), 900 * so that the last trick works only on connected 901 * sockets. 902 * 2. oif also should be the same. 903 */ 904 if (ip6_rt_check(&rt->rt6i_dst, &fl->fl6_dst, np->daddr_cache) || 905 #ifdef CONFIG_IPV6_SUBTREES 906 ip6_rt_check(&rt->rt6i_src, &fl->fl6_src, np->saddr_cache) || 907 #endif 908 (fl->oif && fl->oif != dst->dev->ifindex)) { 909 dst_release(dst); 910 dst = NULL; 911 } 912 913 out: 914 return dst; 915 } 916 917 static int ip6_dst_lookup_tail(struct sock *sk, 918 struct dst_entry **dst, struct flowi *fl) 919 { 920 int err; 921 struct net *net = sock_net(sk); 922 923 if (*dst == NULL) 924 *dst = ip6_route_output(net, sk, fl); 925 926 if ((err = (*dst)->error)) 927 goto out_err_release; 928 929 if (ipv6_addr_any(&fl->fl6_src)) { 930 err = ipv6_dev_get_saddr(net, ip6_dst_idev(*dst)->dev, 931 &fl->fl6_dst, 932 sk ? inet6_sk(sk)->srcprefs : 0, 933 &fl->fl6_src); 934 if (err) 935 goto out_err_release; 936 } 937 938 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD 939 /* 940 * Here if the dst entry we've looked up 941 * has a neighbour entry that is in the INCOMPLETE 942 * state and the src address from the flow is 943 * marked as OPTIMISTIC, we release the found 944 * dst entry and replace it instead with the 945 * dst entry of the nexthop router 946 */ 947 if ((*dst)->neighbour && !((*dst)->neighbour->nud_state & NUD_VALID)) { 948 struct inet6_ifaddr *ifp; 949 struct flowi fl_gw; 950 int redirect; 951 952 ifp = ipv6_get_ifaddr(net, &fl->fl6_src, 953 (*dst)->dev, 1); 954 955 redirect = (ifp && ifp->flags & IFA_F_OPTIMISTIC); 956 if (ifp) 957 in6_ifa_put(ifp); 958 959 if (redirect) { 960 /* 961 * We need to get the dst entry for the 962 * default router instead 963 */ 964 dst_release(*dst); 965 memcpy(&fl_gw, fl, sizeof(struct flowi)); 966 memset(&fl_gw.fl6_dst, 0, sizeof(struct in6_addr)); 967 *dst = ip6_route_output(net, sk, &fl_gw); 968 if ((err = (*dst)->error)) 969 goto out_err_release; 970 } 971 } 972 #endif 973 974 return 0; 975 976 out_err_release: 977 if (err == -ENETUNREACH) 978 IP6_INC_STATS_BH(net, NULL, IPSTATS_MIB_OUTNOROUTES); 979 dst_release(*dst); 980 *dst = NULL; 981 return err; 982 } 983 984 /** 985 * ip6_dst_lookup - perform route lookup on flow 986 * @sk: socket which provides route info 987 * @dst: pointer to dst_entry * for result 988 * @fl: flow to lookup 989 * 990 * This function performs a route lookup on the given flow. 991 * 992 * It returns zero on success, or a standard errno code on error. 993 */ 994 int ip6_dst_lookup(struct sock *sk, struct dst_entry **dst, struct flowi *fl) 995 { 996 *dst = NULL; 997 return ip6_dst_lookup_tail(sk, dst, fl); 998 } 999 EXPORT_SYMBOL_GPL(ip6_dst_lookup); 1000 1001 /** 1002 * ip6_sk_dst_lookup - perform socket cached route lookup on flow 1003 * @sk: socket which provides the dst cache and route info 1004 * @dst: pointer to dst_entry * for result 1005 * @fl: flow to lookup 1006 * 1007 * This function performs a route lookup on the given flow with the 1008 * possibility of using the cached route in the socket if it is valid. 1009 * It will take the socket dst lock when operating on the dst cache. 1010 * As a result, this function can only be used in process context. 1011 * 1012 * It returns zero on success, or a standard errno code on error. 1013 */ 1014 int ip6_sk_dst_lookup(struct sock *sk, struct dst_entry **dst, struct flowi *fl) 1015 { 1016 *dst = NULL; 1017 if (sk) { 1018 *dst = sk_dst_check(sk, inet6_sk(sk)->dst_cookie); 1019 *dst = ip6_sk_dst_check(sk, *dst, fl); 1020 } 1021 1022 return ip6_dst_lookup_tail(sk, dst, fl); 1023 } 1024 EXPORT_SYMBOL_GPL(ip6_sk_dst_lookup); 1025 1026 static inline int ip6_ufo_append_data(struct sock *sk, 1027 int getfrag(void *from, char *to, int offset, int len, 1028 int odd, struct sk_buff *skb), 1029 void *from, int length, int hh_len, int fragheaderlen, 1030 int transhdrlen, int mtu,unsigned int flags) 1031 1032 { 1033 struct sk_buff *skb; 1034 int err; 1035 1036 /* There is support for UDP large send offload by network 1037 * device, so create one single skb packet containing complete 1038 * udp datagram 1039 */ 1040 if ((skb = skb_peek_tail(&sk->sk_write_queue)) == NULL) { 1041 skb = sock_alloc_send_skb(sk, 1042 hh_len + fragheaderlen + transhdrlen + 20, 1043 (flags & MSG_DONTWAIT), &err); 1044 if (skb == NULL) 1045 return -ENOMEM; 1046 1047 /* reserve space for Hardware header */ 1048 skb_reserve(skb, hh_len); 1049 1050 /* create space for UDP/IP header */ 1051 skb_put(skb,fragheaderlen + transhdrlen); 1052 1053 /* initialize network header pointer */ 1054 skb_reset_network_header(skb); 1055 1056 /* initialize protocol header pointer */ 1057 skb->transport_header = skb->network_header + fragheaderlen; 1058 1059 skb->ip_summed = CHECKSUM_PARTIAL; 1060 skb->csum = 0; 1061 sk->sk_sndmsg_off = 0; 1062 } 1063 1064 err = skb_append_datato_frags(sk,skb, getfrag, from, 1065 (length - transhdrlen)); 1066 if (!err) { 1067 struct frag_hdr fhdr; 1068 1069 /* Specify the length of each IPv6 datagram fragment. 1070 * It has to be a multiple of 8. 1071 */ 1072 skb_shinfo(skb)->gso_size = (mtu - fragheaderlen - 1073 sizeof(struct frag_hdr)) & ~7; 1074 skb_shinfo(skb)->gso_type = SKB_GSO_UDP; 1075 ipv6_select_ident(&fhdr); 1076 skb_shinfo(skb)->ip6_frag_id = fhdr.identification; 1077 __skb_queue_tail(&sk->sk_write_queue, skb); 1078 1079 return 0; 1080 } 1081 /* There is not enough support do UPD LSO, 1082 * so follow normal path 1083 */ 1084 kfree_skb(skb); 1085 1086 return err; 1087 } 1088 1089 static inline struct ipv6_opt_hdr *ip6_opt_dup(struct ipv6_opt_hdr *src, 1090 gfp_t gfp) 1091 { 1092 return src ? kmemdup(src, (src->hdrlen + 1) * 8, gfp) : NULL; 1093 } 1094 1095 static inline struct ipv6_rt_hdr *ip6_rthdr_dup(struct ipv6_rt_hdr *src, 1096 gfp_t gfp) 1097 { 1098 return src ? kmemdup(src, (src->hdrlen + 1) * 8, gfp) : NULL; 1099 } 1100 1101 int ip6_append_data(struct sock *sk, int getfrag(void *from, char *to, 1102 int offset, int len, int odd, struct sk_buff *skb), 1103 void *from, int length, int transhdrlen, 1104 int hlimit, int tclass, struct ipv6_txoptions *opt, struct flowi *fl, 1105 struct rt6_info *rt, unsigned int flags, int dontfrag) 1106 { 1107 struct inet_sock *inet = inet_sk(sk); 1108 struct ipv6_pinfo *np = inet6_sk(sk); 1109 struct sk_buff *skb; 1110 unsigned int maxfraglen, fragheaderlen; 1111 int exthdrlen; 1112 int hh_len; 1113 int mtu; 1114 int copy; 1115 int err; 1116 int offset = 0; 1117 int csummode = CHECKSUM_NONE; 1118 1119 if (flags&MSG_PROBE) 1120 return 0; 1121 if (skb_queue_empty(&sk->sk_write_queue)) { 1122 /* 1123 * setup for corking 1124 */ 1125 if (opt) { 1126 if (WARN_ON(np->cork.opt)) 1127 return -EINVAL; 1128 1129 np->cork.opt = kmalloc(opt->tot_len, sk->sk_allocation); 1130 if (unlikely(np->cork.opt == NULL)) 1131 return -ENOBUFS; 1132 1133 np->cork.opt->tot_len = opt->tot_len; 1134 np->cork.opt->opt_flen = opt->opt_flen; 1135 np->cork.opt->opt_nflen = opt->opt_nflen; 1136 1137 np->cork.opt->dst0opt = ip6_opt_dup(opt->dst0opt, 1138 sk->sk_allocation); 1139 if (opt->dst0opt && !np->cork.opt->dst0opt) 1140 return -ENOBUFS; 1141 1142 np->cork.opt->dst1opt = ip6_opt_dup(opt->dst1opt, 1143 sk->sk_allocation); 1144 if (opt->dst1opt && !np->cork.opt->dst1opt) 1145 return -ENOBUFS; 1146 1147 np->cork.opt->hopopt = ip6_opt_dup(opt->hopopt, 1148 sk->sk_allocation); 1149 if (opt->hopopt && !np->cork.opt->hopopt) 1150 return -ENOBUFS; 1151 1152 np->cork.opt->srcrt = ip6_rthdr_dup(opt->srcrt, 1153 sk->sk_allocation); 1154 if (opt->srcrt && !np->cork.opt->srcrt) 1155 return -ENOBUFS; 1156 1157 /* need source address above miyazawa*/ 1158 } 1159 dst_hold(&rt->u.dst); 1160 inet->cork.dst = &rt->u.dst; 1161 inet->cork.fl = *fl; 1162 np->cork.hop_limit = hlimit; 1163 np->cork.tclass = tclass; 1164 mtu = np->pmtudisc == IPV6_PMTUDISC_PROBE ? 1165 rt->u.dst.dev->mtu : dst_mtu(rt->u.dst.path); 1166 if (np->frag_size < mtu) { 1167 if (np->frag_size) 1168 mtu = np->frag_size; 1169 } 1170 inet->cork.fragsize = mtu; 1171 if (dst_allfrag(rt->u.dst.path)) 1172 inet->cork.flags |= IPCORK_ALLFRAG; 1173 inet->cork.length = 0; 1174 sk->sk_sndmsg_page = NULL; 1175 sk->sk_sndmsg_off = 0; 1176 exthdrlen = rt->u.dst.header_len + (opt ? opt->opt_flen : 0) - 1177 rt->rt6i_nfheader_len; 1178 length += exthdrlen; 1179 transhdrlen += exthdrlen; 1180 } else { 1181 rt = (struct rt6_info *)inet->cork.dst; 1182 fl = &inet->cork.fl; 1183 opt = np->cork.opt; 1184 transhdrlen = 0; 1185 exthdrlen = 0; 1186 mtu = inet->cork.fragsize; 1187 } 1188 1189 hh_len = LL_RESERVED_SPACE(rt->u.dst.dev); 1190 1191 fragheaderlen = sizeof(struct ipv6hdr) + rt->rt6i_nfheader_len + 1192 (opt ? opt->opt_nflen : 0); 1193 maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen - sizeof(struct frag_hdr); 1194 1195 if (mtu <= sizeof(struct ipv6hdr) + IPV6_MAXPLEN) { 1196 if (inet->cork.length + length > sizeof(struct ipv6hdr) + IPV6_MAXPLEN - fragheaderlen) { 1197 ipv6_local_error(sk, EMSGSIZE, fl, mtu-exthdrlen); 1198 return -EMSGSIZE; 1199 } 1200 } 1201 1202 /* 1203 * Let's try using as much space as possible. 1204 * Use MTU if total length of the message fits into the MTU. 1205 * Otherwise, we need to reserve fragment header and 1206 * fragment alignment (= 8-15 octects, in total). 1207 * 1208 * Note that we may need to "move" the data from the tail of 1209 * of the buffer to the new fragment when we split 1210 * the message. 1211 * 1212 * FIXME: It may be fragmented into multiple chunks 1213 * at once if non-fragmentable extension headers 1214 * are too large. 1215 * --yoshfuji 1216 */ 1217 1218 inet->cork.length += length; 1219 if (length > mtu) { 1220 int proto = sk->sk_protocol; 1221 if (dontfrag && (proto == IPPROTO_UDP || proto == IPPROTO_RAW)){ 1222 ipv6_local_rxpmtu(sk, fl, mtu-exthdrlen); 1223 return -EMSGSIZE; 1224 } 1225 1226 if (proto == IPPROTO_UDP && 1227 (rt->u.dst.dev->features & NETIF_F_UFO)) { 1228 1229 err = ip6_ufo_append_data(sk, getfrag, from, length, 1230 hh_len, fragheaderlen, 1231 transhdrlen, mtu, flags); 1232 if (err) 1233 goto error; 1234 return 0; 1235 } 1236 } 1237 1238 if ((skb = skb_peek_tail(&sk->sk_write_queue)) == NULL) 1239 goto alloc_new_skb; 1240 1241 while (length > 0) { 1242 /* Check if the remaining data fits into current packet. */ 1243 copy = (inet->cork.length <= mtu && !(inet->cork.flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - skb->len; 1244 if (copy < length) 1245 copy = maxfraglen - skb->len; 1246 1247 if (copy <= 0) { 1248 char *data; 1249 unsigned int datalen; 1250 unsigned int fraglen; 1251 unsigned int fraggap; 1252 unsigned int alloclen; 1253 struct sk_buff *skb_prev; 1254 alloc_new_skb: 1255 skb_prev = skb; 1256 1257 /* There's no room in the current skb */ 1258 if (skb_prev) 1259 fraggap = skb_prev->len - maxfraglen; 1260 else 1261 fraggap = 0; 1262 1263 /* 1264 * If remaining data exceeds the mtu, 1265 * we know we need more fragment(s). 1266 */ 1267 datalen = length + fraggap; 1268 if (datalen > (inet->cork.length <= mtu && !(inet->cork.flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - fragheaderlen) 1269 datalen = maxfraglen - fragheaderlen; 1270 1271 fraglen = datalen + fragheaderlen; 1272 if ((flags & MSG_MORE) && 1273 !(rt->u.dst.dev->features&NETIF_F_SG)) 1274 alloclen = mtu; 1275 else 1276 alloclen = datalen + fragheaderlen; 1277 1278 /* 1279 * The last fragment gets additional space at tail. 1280 * Note: we overallocate on fragments with MSG_MODE 1281 * because we have no idea if we're the last one. 1282 */ 1283 if (datalen == length + fraggap) 1284 alloclen += rt->u.dst.trailer_len; 1285 1286 /* 1287 * We just reserve space for fragment header. 1288 * Note: this may be overallocation if the message 1289 * (without MSG_MORE) fits into the MTU. 1290 */ 1291 alloclen += sizeof(struct frag_hdr); 1292 1293 if (transhdrlen) { 1294 skb = sock_alloc_send_skb(sk, 1295 alloclen + hh_len, 1296 (flags & MSG_DONTWAIT), &err); 1297 } else { 1298 skb = NULL; 1299 if (atomic_read(&sk->sk_wmem_alloc) <= 1300 2 * sk->sk_sndbuf) 1301 skb = sock_wmalloc(sk, 1302 alloclen + hh_len, 1, 1303 sk->sk_allocation); 1304 if (unlikely(skb == NULL)) 1305 err = -ENOBUFS; 1306 } 1307 if (skb == NULL) 1308 goto error; 1309 /* 1310 * Fill in the control structures 1311 */ 1312 skb->ip_summed = csummode; 1313 skb->csum = 0; 1314 /* reserve for fragmentation */ 1315 skb_reserve(skb, hh_len+sizeof(struct frag_hdr)); 1316 1317 /* 1318 * Find where to start putting bytes 1319 */ 1320 data = skb_put(skb, fraglen); 1321 skb_set_network_header(skb, exthdrlen); 1322 data += fragheaderlen; 1323 skb->transport_header = (skb->network_header + 1324 fragheaderlen); 1325 if (fraggap) { 1326 skb->csum = skb_copy_and_csum_bits( 1327 skb_prev, maxfraglen, 1328 data + transhdrlen, fraggap, 0); 1329 skb_prev->csum = csum_sub(skb_prev->csum, 1330 skb->csum); 1331 data += fraggap; 1332 pskb_trim_unique(skb_prev, maxfraglen); 1333 } 1334 copy = datalen - transhdrlen - fraggap; 1335 if (copy < 0) { 1336 err = -EINVAL; 1337 kfree_skb(skb); 1338 goto error; 1339 } else if (copy > 0 && getfrag(from, data + transhdrlen, offset, copy, fraggap, skb) < 0) { 1340 err = -EFAULT; 1341 kfree_skb(skb); 1342 goto error; 1343 } 1344 1345 offset += copy; 1346 length -= datalen - fraggap; 1347 transhdrlen = 0; 1348 exthdrlen = 0; 1349 csummode = CHECKSUM_NONE; 1350 1351 /* 1352 * Put the packet on the pending queue 1353 */ 1354 __skb_queue_tail(&sk->sk_write_queue, skb); 1355 continue; 1356 } 1357 1358 if (copy > length) 1359 copy = length; 1360 1361 if (!(rt->u.dst.dev->features&NETIF_F_SG)) { 1362 unsigned int off; 1363 1364 off = skb->len; 1365 if (getfrag(from, skb_put(skb, copy), 1366 offset, copy, off, skb) < 0) { 1367 __skb_trim(skb, off); 1368 err = -EFAULT; 1369 goto error; 1370 } 1371 } else { 1372 int i = skb_shinfo(skb)->nr_frags; 1373 skb_frag_t *frag = &skb_shinfo(skb)->frags[i-1]; 1374 struct page *page = sk->sk_sndmsg_page; 1375 int off = sk->sk_sndmsg_off; 1376 unsigned int left; 1377 1378 if (page && (left = PAGE_SIZE - off) > 0) { 1379 if (copy >= left) 1380 copy = left; 1381 if (page != frag->page) { 1382 if (i == MAX_SKB_FRAGS) { 1383 err = -EMSGSIZE; 1384 goto error; 1385 } 1386 get_page(page); 1387 skb_fill_page_desc(skb, i, page, sk->sk_sndmsg_off, 0); 1388 frag = &skb_shinfo(skb)->frags[i]; 1389 } 1390 } else if(i < MAX_SKB_FRAGS) { 1391 if (copy > PAGE_SIZE) 1392 copy = PAGE_SIZE; 1393 page = alloc_pages(sk->sk_allocation, 0); 1394 if (page == NULL) { 1395 err = -ENOMEM; 1396 goto error; 1397 } 1398 sk->sk_sndmsg_page = page; 1399 sk->sk_sndmsg_off = 0; 1400 1401 skb_fill_page_desc(skb, i, page, 0, 0); 1402 frag = &skb_shinfo(skb)->frags[i]; 1403 } else { 1404 err = -EMSGSIZE; 1405 goto error; 1406 } 1407 if (getfrag(from, page_address(frag->page)+frag->page_offset+frag->size, offset, copy, skb->len, skb) < 0) { 1408 err = -EFAULT; 1409 goto error; 1410 } 1411 sk->sk_sndmsg_off += copy; 1412 frag->size += copy; 1413 skb->len += copy; 1414 skb->data_len += copy; 1415 skb->truesize += copy; 1416 atomic_add(copy, &sk->sk_wmem_alloc); 1417 } 1418 offset += copy; 1419 length -= copy; 1420 } 1421 return 0; 1422 error: 1423 inet->cork.length -= length; 1424 IP6_INC_STATS(sock_net(sk), rt->rt6i_idev, IPSTATS_MIB_OUTDISCARDS); 1425 return err; 1426 } 1427 1428 static void ip6_cork_release(struct inet_sock *inet, struct ipv6_pinfo *np) 1429 { 1430 if (np->cork.opt) { 1431 kfree(np->cork.opt->dst0opt); 1432 kfree(np->cork.opt->dst1opt); 1433 kfree(np->cork.opt->hopopt); 1434 kfree(np->cork.opt->srcrt); 1435 kfree(np->cork.opt); 1436 np->cork.opt = NULL; 1437 } 1438 1439 if (inet->cork.dst) { 1440 dst_release(inet->cork.dst); 1441 inet->cork.dst = NULL; 1442 inet->cork.flags &= ~IPCORK_ALLFRAG; 1443 } 1444 memset(&inet->cork.fl, 0, sizeof(inet->cork.fl)); 1445 } 1446 1447 int ip6_push_pending_frames(struct sock *sk) 1448 { 1449 struct sk_buff *skb, *tmp_skb; 1450 struct sk_buff **tail_skb; 1451 struct in6_addr final_dst_buf, *final_dst = &final_dst_buf; 1452 struct inet_sock *inet = inet_sk(sk); 1453 struct ipv6_pinfo *np = inet6_sk(sk); 1454 struct net *net = sock_net(sk); 1455 struct ipv6hdr *hdr; 1456 struct ipv6_txoptions *opt = np->cork.opt; 1457 struct rt6_info *rt = (struct rt6_info *)inet->cork.dst; 1458 struct flowi *fl = &inet->cork.fl; 1459 unsigned char proto = fl->proto; 1460 int err = 0; 1461 1462 if ((skb = __skb_dequeue(&sk->sk_write_queue)) == NULL) 1463 goto out; 1464 tail_skb = &(skb_shinfo(skb)->frag_list); 1465 1466 /* move skb->data to ip header from ext header */ 1467 if (skb->data < skb_network_header(skb)) 1468 __skb_pull(skb, skb_network_offset(skb)); 1469 while ((tmp_skb = __skb_dequeue(&sk->sk_write_queue)) != NULL) { 1470 __skb_pull(tmp_skb, skb_network_header_len(skb)); 1471 *tail_skb = tmp_skb; 1472 tail_skb = &(tmp_skb->next); 1473 skb->len += tmp_skb->len; 1474 skb->data_len += tmp_skb->len; 1475 skb->truesize += tmp_skb->truesize; 1476 tmp_skb->destructor = NULL; 1477 tmp_skb->sk = NULL; 1478 } 1479 1480 /* Allow local fragmentation. */ 1481 if (np->pmtudisc < IPV6_PMTUDISC_DO) 1482 skb->local_df = 1; 1483 1484 ipv6_addr_copy(final_dst, &fl->fl6_dst); 1485 __skb_pull(skb, skb_network_header_len(skb)); 1486 if (opt && opt->opt_flen) 1487 ipv6_push_frag_opts(skb, opt, &proto); 1488 if (opt && opt->opt_nflen) 1489 ipv6_push_nfrag_opts(skb, opt, &proto, &final_dst); 1490 1491 skb_push(skb, sizeof(struct ipv6hdr)); 1492 skb_reset_network_header(skb); 1493 hdr = ipv6_hdr(skb); 1494 1495 *(__be32*)hdr = fl->fl6_flowlabel | 1496 htonl(0x60000000 | ((int)np->cork.tclass << 20)); 1497 1498 hdr->hop_limit = np->cork.hop_limit; 1499 hdr->nexthdr = proto; 1500 ipv6_addr_copy(&hdr->saddr, &fl->fl6_src); 1501 ipv6_addr_copy(&hdr->daddr, final_dst); 1502 1503 skb->priority = sk->sk_priority; 1504 skb->mark = sk->sk_mark; 1505 1506 skb_dst_set(skb, dst_clone(&rt->u.dst)); 1507 IP6_UPD_PO_STATS(net, rt->rt6i_idev, IPSTATS_MIB_OUT, skb->len); 1508 if (proto == IPPROTO_ICMPV6) { 1509 struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb)); 1510 1511 ICMP6MSGOUT_INC_STATS_BH(net, idev, icmp6_hdr(skb)->icmp6_type); 1512 ICMP6_INC_STATS_BH(net, idev, ICMP6_MIB_OUTMSGS); 1513 } 1514 1515 err = ip6_local_out(skb); 1516 if (err) { 1517 if (err > 0) 1518 err = net_xmit_errno(err); 1519 if (err) 1520 goto error; 1521 } 1522 1523 out: 1524 ip6_cork_release(inet, np); 1525 return err; 1526 error: 1527 IP6_INC_STATS(net, rt->rt6i_idev, IPSTATS_MIB_OUTDISCARDS); 1528 goto out; 1529 } 1530 1531 void ip6_flush_pending_frames(struct sock *sk) 1532 { 1533 struct sk_buff *skb; 1534 1535 while ((skb = __skb_dequeue_tail(&sk->sk_write_queue)) != NULL) { 1536 if (skb_dst(skb)) 1537 IP6_INC_STATS(sock_net(sk), ip6_dst_idev(skb_dst(skb)), 1538 IPSTATS_MIB_OUTDISCARDS); 1539 kfree_skb(skb); 1540 } 1541 1542 ip6_cork_release(inet_sk(sk), inet6_sk(sk)); 1543 } 1544