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 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 struct neighbour *neigh; 104 105 skb->protocol = htons(ETH_P_IPV6); 106 skb->dev = dev; 107 108 if (ipv6_addr_is_multicast(&ipv6_hdr(skb)->daddr)) { 109 struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb)); 110 111 if (!(dev->flags & IFF_LOOPBACK) && sk_mc_loop(skb->sk) && 112 ((mroute6_socket(dev_net(dev), skb) && 113 !(IP6CB(skb)->flags & IP6SKB_FORWARDED)) || 114 ipv6_chk_mcast_addr(dev, &ipv6_hdr(skb)->daddr, 115 &ipv6_hdr(skb)->saddr))) { 116 struct sk_buff *newskb = skb_clone(skb, GFP_ATOMIC); 117 118 /* Do not check for IFF_ALLMULTI; multicast routing 119 is not supported in any case. 120 */ 121 if (newskb) 122 NF_HOOK(NFPROTO_IPV6, NF_INET_POST_ROUTING, 123 newskb, NULL, newskb->dev, 124 ip6_dev_loopback_xmit); 125 126 if (ipv6_hdr(skb)->hop_limit == 0) { 127 IP6_INC_STATS(dev_net(dev), idev, 128 IPSTATS_MIB_OUTDISCARDS); 129 kfree_skb(skb); 130 return 0; 131 } 132 } 133 134 IP6_UPD_PO_STATS(dev_net(dev), idev, IPSTATS_MIB_OUTMCAST, 135 skb->len); 136 } 137 138 rcu_read_lock(); 139 neigh = dst_get_neighbour_noref(dst); 140 if (neigh) { 141 int res = neigh_output(neigh, skb); 142 143 rcu_read_unlock(); 144 return res; 145 } 146 rcu_read_unlock(); 147 IP6_INC_STATS_BH(dev_net(dst->dev), 148 ip6_dst_idev(dst), IPSTATS_MIB_OUTNOROUTES); 149 kfree_skb(skb); 150 return -EINVAL; 151 } 152 153 static int ip6_finish_output(struct sk_buff *skb) 154 { 155 if ((skb->len > ip6_skb_dst_mtu(skb) && !skb_is_gso(skb)) || 156 dst_allfrag(skb_dst(skb))) 157 return ip6_fragment(skb, ip6_finish_output2); 158 else 159 return ip6_finish_output2(skb); 160 } 161 162 int ip6_output(struct sk_buff *skb) 163 { 164 struct net_device *dev = skb_dst(skb)->dev; 165 struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb)); 166 if (unlikely(idev->cnf.disable_ipv6)) { 167 IP6_INC_STATS(dev_net(dev), idev, 168 IPSTATS_MIB_OUTDISCARDS); 169 kfree_skb(skb); 170 return 0; 171 } 172 173 return NF_HOOK_COND(NFPROTO_IPV6, NF_INET_POST_ROUTING, skb, NULL, dev, 174 ip6_finish_output, 175 !(IP6CB(skb)->flags & IP6SKB_REROUTED)); 176 } 177 178 /* 179 * xmit an sk_buff (used by TCP, SCTP and DCCP) 180 */ 181 182 int ip6_xmit(struct sock *sk, struct sk_buff *skb, struct flowi6 *fl6, 183 struct ipv6_txoptions *opt, int tclass) 184 { 185 struct net *net = sock_net(sk); 186 struct ipv6_pinfo *np = inet6_sk(sk); 187 struct in6_addr *first_hop = &fl6->daddr; 188 struct dst_entry *dst = skb_dst(skb); 189 struct ipv6hdr *hdr; 190 u8 proto = fl6->flowi6_proto; 191 int seg_len = skb->len; 192 int hlimit = -1; 193 u32 mtu; 194 195 if (opt) { 196 unsigned int head_room; 197 198 /* First: exthdrs may take lots of space (~8K for now) 199 MAX_HEADER is not enough. 200 */ 201 head_room = opt->opt_nflen + opt->opt_flen; 202 seg_len += head_room; 203 head_room += sizeof(struct ipv6hdr) + LL_RESERVED_SPACE(dst->dev); 204 205 if (skb_headroom(skb) < head_room) { 206 struct sk_buff *skb2 = skb_realloc_headroom(skb, head_room); 207 if (skb2 == NULL) { 208 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), 209 IPSTATS_MIB_OUTDISCARDS); 210 kfree_skb(skb); 211 return -ENOBUFS; 212 } 213 consume_skb(skb); 214 skb = skb2; 215 skb_set_owner_w(skb, sk); 216 } 217 if (opt->opt_flen) 218 ipv6_push_frag_opts(skb, opt, &proto); 219 if (opt->opt_nflen) 220 ipv6_push_nfrag_opts(skb, opt, &proto, &first_hop); 221 } 222 223 skb_push(skb, sizeof(struct ipv6hdr)); 224 skb_reset_network_header(skb); 225 hdr = ipv6_hdr(skb); 226 227 /* 228 * Fill in the IPv6 header 229 */ 230 if (np) 231 hlimit = np->hop_limit; 232 if (hlimit < 0) 233 hlimit = ip6_dst_hoplimit(dst); 234 235 *(__be32 *)hdr = htonl(0x60000000 | (tclass << 20)) | fl6->flowlabel; 236 237 hdr->payload_len = htons(seg_len); 238 hdr->nexthdr = proto; 239 hdr->hop_limit = hlimit; 240 241 hdr->saddr = fl6->saddr; 242 hdr->daddr = *first_hop; 243 244 skb->priority = sk->sk_priority; 245 skb->mark = sk->sk_mark; 246 247 mtu = dst_mtu(dst); 248 if ((skb->len <= mtu) || skb->local_df || skb_is_gso(skb)) { 249 IP6_UPD_PO_STATS(net, ip6_dst_idev(skb_dst(skb)), 250 IPSTATS_MIB_OUT, skb->len); 251 return NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT, skb, NULL, 252 dst->dev, dst_output); 253 } 254 255 net_dbg_ratelimited("IPv6: sending pkt_too_big to self\n"); 256 skb->dev = dst->dev; 257 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu); 258 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_FRAGFAILS); 259 kfree_skb(skb); 260 return -EMSGSIZE; 261 } 262 263 EXPORT_SYMBOL(ip6_xmit); 264 265 /* 266 * To avoid extra problems ND packets are send through this 267 * routine. It's code duplication but I really want to avoid 268 * extra checks since ipv6_build_header is used by TCP (which 269 * is for us performance critical) 270 */ 271 272 int ip6_nd_hdr(struct sock *sk, struct sk_buff *skb, struct net_device *dev, 273 const struct in6_addr *saddr, const struct in6_addr *daddr, 274 int proto, int len) 275 { 276 struct ipv6_pinfo *np = inet6_sk(sk); 277 struct ipv6hdr *hdr; 278 279 skb->protocol = htons(ETH_P_IPV6); 280 skb->dev = dev; 281 282 skb_reset_network_header(skb); 283 skb_put(skb, sizeof(struct ipv6hdr)); 284 hdr = ipv6_hdr(skb); 285 286 *(__be32*)hdr = htonl(0x60000000); 287 288 hdr->payload_len = htons(len); 289 hdr->nexthdr = proto; 290 hdr->hop_limit = np->hop_limit; 291 292 hdr->saddr = *saddr; 293 hdr->daddr = *daddr; 294 295 return 0; 296 } 297 298 static int ip6_call_ra_chain(struct sk_buff *skb, int sel) 299 { 300 struct ip6_ra_chain *ra; 301 struct sock *last = NULL; 302 303 read_lock(&ip6_ra_lock); 304 for (ra = ip6_ra_chain; ra; ra = ra->next) { 305 struct sock *sk = ra->sk; 306 if (sk && ra->sel == sel && 307 (!sk->sk_bound_dev_if || 308 sk->sk_bound_dev_if == skb->dev->ifindex)) { 309 if (last) { 310 struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC); 311 if (skb2) 312 rawv6_rcv(last, skb2); 313 } 314 last = sk; 315 } 316 } 317 318 if (last) { 319 rawv6_rcv(last, skb); 320 read_unlock(&ip6_ra_lock); 321 return 1; 322 } 323 read_unlock(&ip6_ra_lock); 324 return 0; 325 } 326 327 static int ip6_forward_proxy_check(struct sk_buff *skb) 328 { 329 struct ipv6hdr *hdr = ipv6_hdr(skb); 330 u8 nexthdr = hdr->nexthdr; 331 __be16 frag_off; 332 int offset; 333 334 if (ipv6_ext_hdr(nexthdr)) { 335 offset = ipv6_skip_exthdr(skb, sizeof(*hdr), &nexthdr, &frag_off); 336 if (offset < 0) 337 return 0; 338 } else 339 offset = sizeof(struct ipv6hdr); 340 341 if (nexthdr == IPPROTO_ICMPV6) { 342 struct icmp6hdr *icmp6; 343 344 if (!pskb_may_pull(skb, (skb_network_header(skb) + 345 offset + 1 - skb->data))) 346 return 0; 347 348 icmp6 = (struct icmp6hdr *)(skb_network_header(skb) + offset); 349 350 switch (icmp6->icmp6_type) { 351 case NDISC_ROUTER_SOLICITATION: 352 case NDISC_ROUTER_ADVERTISEMENT: 353 case NDISC_NEIGHBOUR_SOLICITATION: 354 case NDISC_NEIGHBOUR_ADVERTISEMENT: 355 case NDISC_REDIRECT: 356 /* For reaction involving unicast neighbor discovery 357 * message destined to the proxied address, pass it to 358 * input function. 359 */ 360 return 1; 361 default: 362 break; 363 } 364 } 365 366 /* 367 * The proxying router can't forward traffic sent to a link-local 368 * address, so signal the sender and discard the packet. This 369 * behavior is clarified by the MIPv6 specification. 370 */ 371 if (ipv6_addr_type(&hdr->daddr) & IPV6_ADDR_LINKLOCAL) { 372 dst_link_failure(skb); 373 return -1; 374 } 375 376 return 0; 377 } 378 379 static inline int ip6_forward_finish(struct sk_buff *skb) 380 { 381 return dst_output(skb); 382 } 383 384 int ip6_forward(struct sk_buff *skb) 385 { 386 struct dst_entry *dst = skb_dst(skb); 387 struct ipv6hdr *hdr = ipv6_hdr(skb); 388 struct inet6_skb_parm *opt = IP6CB(skb); 389 struct net *net = dev_net(dst->dev); 390 u32 mtu; 391 392 if (net->ipv6.devconf_all->forwarding == 0) 393 goto error; 394 395 if (skb_warn_if_lro(skb)) 396 goto drop; 397 398 if (!xfrm6_policy_check(NULL, XFRM_POLICY_FWD, skb)) { 399 IP6_INC_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_INDISCARDS); 400 goto drop; 401 } 402 403 if (skb->pkt_type != PACKET_HOST) 404 goto drop; 405 406 skb_forward_csum(skb); 407 408 /* 409 * We DO NOT make any processing on 410 * RA packets, pushing them to user level AS IS 411 * without ane WARRANTY that application will be able 412 * to interpret them. The reason is that we 413 * cannot make anything clever here. 414 * 415 * We are not end-node, so that if packet contains 416 * AH/ESP, we cannot make anything. 417 * Defragmentation also would be mistake, RA packets 418 * cannot be fragmented, because there is no warranty 419 * that different fragments will go along one path. --ANK 420 */ 421 if (opt->ra) { 422 u8 *ptr = skb_network_header(skb) + opt->ra; 423 if (ip6_call_ra_chain(skb, (ptr[2]<<8) + ptr[3])) 424 return 0; 425 } 426 427 /* 428 * check and decrement ttl 429 */ 430 if (hdr->hop_limit <= 1) { 431 /* Force OUTPUT device used as source address */ 432 skb->dev = dst->dev; 433 icmpv6_send(skb, ICMPV6_TIME_EXCEED, ICMPV6_EXC_HOPLIMIT, 0); 434 IP6_INC_STATS_BH(net, 435 ip6_dst_idev(dst), IPSTATS_MIB_INHDRERRORS); 436 437 kfree_skb(skb); 438 return -ETIMEDOUT; 439 } 440 441 /* XXX: idev->cnf.proxy_ndp? */ 442 if (net->ipv6.devconf_all->proxy_ndp && 443 pneigh_lookup(&nd_tbl, net, &hdr->daddr, skb->dev, 0)) { 444 int proxied = ip6_forward_proxy_check(skb); 445 if (proxied > 0) 446 return ip6_input(skb); 447 else if (proxied < 0) { 448 IP6_INC_STATS(net, ip6_dst_idev(dst), 449 IPSTATS_MIB_INDISCARDS); 450 goto drop; 451 } 452 } 453 454 if (!xfrm6_route_forward(skb)) { 455 IP6_INC_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_INDISCARDS); 456 goto drop; 457 } 458 dst = skb_dst(skb); 459 460 /* IPv6 specs say nothing about it, but it is clear that we cannot 461 send redirects to source routed frames. 462 We don't send redirects to frames decapsulated from IPsec. 463 */ 464 if (skb->dev == dst->dev && opt->srcrt == 0 && !skb_sec_path(skb)) { 465 struct in6_addr *target = NULL; 466 struct rt6_info *rt; 467 468 /* 469 * incoming and outgoing devices are the same 470 * send a redirect. 471 */ 472 473 rt = (struct rt6_info *) dst; 474 if (rt->rt6i_flags & RTF_GATEWAY) 475 target = &rt->rt6i_gateway; 476 else 477 target = &hdr->daddr; 478 479 if (!rt->rt6i_peer) 480 rt6_bind_peer(rt, 1); 481 482 /* Limit redirects both by destination (here) 483 and by source (inside ndisc_send_redirect) 484 */ 485 if (inet_peer_xrlim_allow(rt->rt6i_peer, 1*HZ)) 486 ndisc_send_redirect(skb, target); 487 } else { 488 int addrtype = ipv6_addr_type(&hdr->saddr); 489 490 /* This check is security critical. */ 491 if (addrtype == IPV6_ADDR_ANY || 492 addrtype & (IPV6_ADDR_MULTICAST | IPV6_ADDR_LOOPBACK)) 493 goto error; 494 if (addrtype & IPV6_ADDR_LINKLOCAL) { 495 icmpv6_send(skb, ICMPV6_DEST_UNREACH, 496 ICMPV6_NOT_NEIGHBOUR, 0); 497 goto error; 498 } 499 } 500 501 mtu = dst_mtu(dst); 502 if (mtu < IPV6_MIN_MTU) 503 mtu = IPV6_MIN_MTU; 504 505 if (skb->len > mtu && !skb_is_gso(skb)) { 506 /* Again, force OUTPUT device used as source address */ 507 skb->dev = dst->dev; 508 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu); 509 IP6_INC_STATS_BH(net, 510 ip6_dst_idev(dst), IPSTATS_MIB_INTOOBIGERRORS); 511 IP6_INC_STATS_BH(net, 512 ip6_dst_idev(dst), IPSTATS_MIB_FRAGFAILS); 513 kfree_skb(skb); 514 return -EMSGSIZE; 515 } 516 517 if (skb_cow(skb, dst->dev->hard_header_len)) { 518 IP6_INC_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTDISCARDS); 519 goto drop; 520 } 521 522 hdr = ipv6_hdr(skb); 523 524 /* Mangling hops number delayed to point after skb COW */ 525 526 hdr->hop_limit--; 527 528 IP6_INC_STATS_BH(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTFORWDATAGRAMS); 529 return NF_HOOK(NFPROTO_IPV6, NF_INET_FORWARD, skb, skb->dev, dst->dev, 530 ip6_forward_finish); 531 532 error: 533 IP6_INC_STATS_BH(net, ip6_dst_idev(dst), IPSTATS_MIB_INADDRERRORS); 534 drop: 535 kfree_skb(skb); 536 return -EINVAL; 537 } 538 539 static void ip6_copy_metadata(struct sk_buff *to, struct sk_buff *from) 540 { 541 to->pkt_type = from->pkt_type; 542 to->priority = from->priority; 543 to->protocol = from->protocol; 544 skb_dst_drop(to); 545 skb_dst_set(to, dst_clone(skb_dst(from))); 546 to->dev = from->dev; 547 to->mark = from->mark; 548 549 #ifdef CONFIG_NET_SCHED 550 to->tc_index = from->tc_index; 551 #endif 552 nf_copy(to, from); 553 #if defined(CONFIG_NETFILTER_XT_TARGET_TRACE) || \ 554 defined(CONFIG_NETFILTER_XT_TARGET_TRACE_MODULE) 555 to->nf_trace = from->nf_trace; 556 #endif 557 skb_copy_secmark(to, from); 558 } 559 560 int ip6_find_1stfragopt(struct sk_buff *skb, u8 **nexthdr) 561 { 562 u16 offset = sizeof(struct ipv6hdr); 563 struct ipv6_opt_hdr *exthdr = 564 (struct ipv6_opt_hdr *)(ipv6_hdr(skb) + 1); 565 unsigned int packet_len = skb->tail - skb->network_header; 566 int found_rhdr = 0; 567 *nexthdr = &ipv6_hdr(skb)->nexthdr; 568 569 while (offset + 1 <= packet_len) { 570 571 switch (**nexthdr) { 572 573 case NEXTHDR_HOP: 574 break; 575 case NEXTHDR_ROUTING: 576 found_rhdr = 1; 577 break; 578 case NEXTHDR_DEST: 579 #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE) 580 if (ipv6_find_tlv(skb, offset, IPV6_TLV_HAO) >= 0) 581 break; 582 #endif 583 if (found_rhdr) 584 return offset; 585 break; 586 default : 587 return offset; 588 } 589 590 offset += ipv6_optlen(exthdr); 591 *nexthdr = &exthdr->nexthdr; 592 exthdr = (struct ipv6_opt_hdr *)(skb_network_header(skb) + 593 offset); 594 } 595 596 return offset; 597 } 598 599 void ipv6_select_ident(struct frag_hdr *fhdr, struct rt6_info *rt) 600 { 601 static atomic_t ipv6_fragmentation_id; 602 int old, new; 603 604 if (rt && !(rt->dst.flags & DST_NOPEER)) { 605 struct inet_peer *peer; 606 607 if (!rt->rt6i_peer) 608 rt6_bind_peer(rt, 1); 609 peer = rt->rt6i_peer; 610 if (peer) { 611 fhdr->identification = htonl(inet_getid(peer, 0)); 612 return; 613 } 614 } 615 do { 616 old = atomic_read(&ipv6_fragmentation_id); 617 new = old + 1; 618 if (!new) 619 new = 1; 620 } while (atomic_cmpxchg(&ipv6_fragmentation_id, old, new) != old); 621 fhdr->identification = htonl(new); 622 } 623 624 int ip6_fragment(struct sk_buff *skb, int (*output)(struct sk_buff *)) 625 { 626 struct sk_buff *frag; 627 struct rt6_info *rt = (struct rt6_info*)skb_dst(skb); 628 struct ipv6_pinfo *np = skb->sk ? inet6_sk(skb->sk) : NULL; 629 struct ipv6hdr *tmp_hdr; 630 struct frag_hdr *fh; 631 unsigned int mtu, hlen, left, len; 632 int hroom, troom; 633 __be32 frag_id = 0; 634 int ptr, offset = 0, err=0; 635 u8 *prevhdr, nexthdr = 0; 636 struct net *net = dev_net(skb_dst(skb)->dev); 637 638 hlen = ip6_find_1stfragopt(skb, &prevhdr); 639 nexthdr = *prevhdr; 640 641 mtu = ip6_skb_dst_mtu(skb); 642 643 /* We must not fragment if the socket is set to force MTU discovery 644 * or if the skb it not generated by a local socket. 645 */ 646 if (unlikely(!skb->local_df && skb->len > mtu)) { 647 if (skb->sk && dst_allfrag(skb_dst(skb))) 648 sk_nocaps_add(skb->sk, NETIF_F_GSO_MASK); 649 650 skb->dev = skb_dst(skb)->dev; 651 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu); 652 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), 653 IPSTATS_MIB_FRAGFAILS); 654 kfree_skb(skb); 655 return -EMSGSIZE; 656 } 657 658 if (np && np->frag_size < mtu) { 659 if (np->frag_size) 660 mtu = np->frag_size; 661 } 662 mtu -= hlen + sizeof(struct frag_hdr); 663 664 if (skb_has_frag_list(skb)) { 665 int first_len = skb_pagelen(skb); 666 struct sk_buff *frag2; 667 668 if (first_len - hlen > mtu || 669 ((first_len - hlen) & 7) || 670 skb_cloned(skb)) 671 goto slow_path; 672 673 skb_walk_frags(skb, frag) { 674 /* Correct geometry. */ 675 if (frag->len > mtu || 676 ((frag->len & 7) && frag->next) || 677 skb_headroom(frag) < hlen) 678 goto slow_path_clean; 679 680 /* Partially cloned skb? */ 681 if (skb_shared(frag)) 682 goto slow_path_clean; 683 684 BUG_ON(frag->sk); 685 if (skb->sk) { 686 frag->sk = skb->sk; 687 frag->destructor = sock_wfree; 688 } 689 skb->truesize -= frag->truesize; 690 } 691 692 err = 0; 693 offset = 0; 694 frag = skb_shinfo(skb)->frag_list; 695 skb_frag_list_init(skb); 696 /* BUILD HEADER */ 697 698 *prevhdr = NEXTHDR_FRAGMENT; 699 tmp_hdr = kmemdup(skb_network_header(skb), hlen, GFP_ATOMIC); 700 if (!tmp_hdr) { 701 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), 702 IPSTATS_MIB_FRAGFAILS); 703 return -ENOMEM; 704 } 705 706 __skb_pull(skb, hlen); 707 fh = (struct frag_hdr*)__skb_push(skb, sizeof(struct frag_hdr)); 708 __skb_push(skb, hlen); 709 skb_reset_network_header(skb); 710 memcpy(skb_network_header(skb), tmp_hdr, hlen); 711 712 ipv6_select_ident(fh, rt); 713 fh->nexthdr = nexthdr; 714 fh->reserved = 0; 715 fh->frag_off = htons(IP6_MF); 716 frag_id = fh->identification; 717 718 first_len = skb_pagelen(skb); 719 skb->data_len = first_len - skb_headlen(skb); 720 skb->len = first_len; 721 ipv6_hdr(skb)->payload_len = htons(first_len - 722 sizeof(struct ipv6hdr)); 723 724 dst_hold(&rt->dst); 725 726 for (;;) { 727 /* Prepare header of the next frame, 728 * before previous one went down. */ 729 if (frag) { 730 frag->ip_summed = CHECKSUM_NONE; 731 skb_reset_transport_header(frag); 732 fh = (struct frag_hdr*)__skb_push(frag, sizeof(struct frag_hdr)); 733 __skb_push(frag, hlen); 734 skb_reset_network_header(frag); 735 memcpy(skb_network_header(frag), tmp_hdr, 736 hlen); 737 offset += skb->len - hlen - sizeof(struct frag_hdr); 738 fh->nexthdr = nexthdr; 739 fh->reserved = 0; 740 fh->frag_off = htons(offset); 741 if (frag->next != NULL) 742 fh->frag_off |= htons(IP6_MF); 743 fh->identification = frag_id; 744 ipv6_hdr(frag)->payload_len = 745 htons(frag->len - 746 sizeof(struct ipv6hdr)); 747 ip6_copy_metadata(frag, skb); 748 } 749 750 err = output(skb); 751 if(!err) 752 IP6_INC_STATS(net, ip6_dst_idev(&rt->dst), 753 IPSTATS_MIB_FRAGCREATES); 754 755 if (err || !frag) 756 break; 757 758 skb = frag; 759 frag = skb->next; 760 skb->next = NULL; 761 } 762 763 kfree(tmp_hdr); 764 765 if (err == 0) { 766 IP6_INC_STATS(net, ip6_dst_idev(&rt->dst), 767 IPSTATS_MIB_FRAGOKS); 768 dst_release(&rt->dst); 769 return 0; 770 } 771 772 while (frag) { 773 skb = frag->next; 774 kfree_skb(frag); 775 frag = skb; 776 } 777 778 IP6_INC_STATS(net, ip6_dst_idev(&rt->dst), 779 IPSTATS_MIB_FRAGFAILS); 780 dst_release(&rt->dst); 781 return err; 782 783 slow_path_clean: 784 skb_walk_frags(skb, frag2) { 785 if (frag2 == frag) 786 break; 787 frag2->sk = NULL; 788 frag2->destructor = NULL; 789 skb->truesize += frag2->truesize; 790 } 791 } 792 793 slow_path: 794 if ((skb->ip_summed == CHECKSUM_PARTIAL) && 795 skb_checksum_help(skb)) 796 goto fail; 797 798 left = skb->len - hlen; /* Space per frame */ 799 ptr = hlen; /* Where to start from */ 800 801 /* 802 * Fragment the datagram. 803 */ 804 805 *prevhdr = NEXTHDR_FRAGMENT; 806 hroom = LL_RESERVED_SPACE(rt->dst.dev); 807 troom = rt->dst.dev->needed_tailroom; 808 809 /* 810 * Keep copying data until we run out. 811 */ 812 while(left > 0) { 813 len = left; 814 /* IF: it doesn't fit, use 'mtu' - the data space left */ 815 if (len > mtu) 816 len = mtu; 817 /* IF: we are not sending up to and including the packet end 818 then align the next start on an eight byte boundary */ 819 if (len < left) { 820 len &= ~7; 821 } 822 /* 823 * Allocate buffer. 824 */ 825 826 if ((frag = alloc_skb(len + hlen + sizeof(struct frag_hdr) + 827 hroom + troom, GFP_ATOMIC)) == NULL) { 828 NETDEBUG(KERN_INFO "IPv6: frag: no memory for new fragment!\n"); 829 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), 830 IPSTATS_MIB_FRAGFAILS); 831 err = -ENOMEM; 832 goto fail; 833 } 834 835 /* 836 * Set up data on packet 837 */ 838 839 ip6_copy_metadata(frag, skb); 840 skb_reserve(frag, hroom); 841 skb_put(frag, len + hlen + sizeof(struct frag_hdr)); 842 skb_reset_network_header(frag); 843 fh = (struct frag_hdr *)(skb_network_header(frag) + hlen); 844 frag->transport_header = (frag->network_header + hlen + 845 sizeof(struct frag_hdr)); 846 847 /* 848 * Charge the memory for the fragment to any owner 849 * it might possess 850 */ 851 if (skb->sk) 852 skb_set_owner_w(frag, skb->sk); 853 854 /* 855 * Copy the packet header into the new buffer. 856 */ 857 skb_copy_from_linear_data(skb, skb_network_header(frag), hlen); 858 859 /* 860 * Build fragment header. 861 */ 862 fh->nexthdr = nexthdr; 863 fh->reserved = 0; 864 if (!frag_id) { 865 ipv6_select_ident(fh, rt); 866 frag_id = fh->identification; 867 } else 868 fh->identification = frag_id; 869 870 /* 871 * Copy a block of the IP datagram. 872 */ 873 if (skb_copy_bits(skb, ptr, skb_transport_header(frag), len)) 874 BUG(); 875 left -= len; 876 877 fh->frag_off = htons(offset); 878 if (left > 0) 879 fh->frag_off |= htons(IP6_MF); 880 ipv6_hdr(frag)->payload_len = htons(frag->len - 881 sizeof(struct ipv6hdr)); 882 883 ptr += len; 884 offset += len; 885 886 /* 887 * Put this fragment into the sending queue. 888 */ 889 err = output(frag); 890 if (err) 891 goto fail; 892 893 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), 894 IPSTATS_MIB_FRAGCREATES); 895 } 896 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), 897 IPSTATS_MIB_FRAGOKS); 898 consume_skb(skb); 899 return err; 900 901 fail: 902 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), 903 IPSTATS_MIB_FRAGFAILS); 904 kfree_skb(skb); 905 return err; 906 } 907 908 static inline int ip6_rt_check(const struct rt6key *rt_key, 909 const struct in6_addr *fl_addr, 910 const struct in6_addr *addr_cache) 911 { 912 return (rt_key->plen != 128 || !ipv6_addr_equal(fl_addr, &rt_key->addr)) && 913 (addr_cache == NULL || !ipv6_addr_equal(fl_addr, addr_cache)); 914 } 915 916 static struct dst_entry *ip6_sk_dst_check(struct sock *sk, 917 struct dst_entry *dst, 918 const struct flowi6 *fl6) 919 { 920 struct ipv6_pinfo *np = inet6_sk(sk); 921 struct rt6_info *rt = (struct rt6_info *)dst; 922 923 if (!dst) 924 goto out; 925 926 /* Yes, checking route validity in not connected 927 * case is not very simple. Take into account, 928 * that we do not support routing by source, TOS, 929 * and MSG_DONTROUTE --ANK (980726) 930 * 931 * 1. ip6_rt_check(): If route was host route, 932 * check that cached destination is current. 933 * If it is network route, we still may 934 * check its validity using saved pointer 935 * to the last used address: daddr_cache. 936 * We do not want to save whole address now, 937 * (because main consumer of this service 938 * is tcp, which has not this problem), 939 * so that the last trick works only on connected 940 * sockets. 941 * 2. oif also should be the same. 942 */ 943 if (ip6_rt_check(&rt->rt6i_dst, &fl6->daddr, np->daddr_cache) || 944 #ifdef CONFIG_IPV6_SUBTREES 945 ip6_rt_check(&rt->rt6i_src, &fl6->saddr, np->saddr_cache) || 946 #endif 947 (fl6->flowi6_oif && fl6->flowi6_oif != dst->dev->ifindex)) { 948 dst_release(dst); 949 dst = NULL; 950 } 951 952 out: 953 return dst; 954 } 955 956 static int ip6_dst_lookup_tail(struct sock *sk, 957 struct dst_entry **dst, struct flowi6 *fl6) 958 { 959 struct net *net = sock_net(sk); 960 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD 961 struct neighbour *n; 962 #endif 963 int err; 964 965 if (*dst == NULL) 966 *dst = ip6_route_output(net, sk, fl6); 967 968 if ((err = (*dst)->error)) 969 goto out_err_release; 970 971 if (ipv6_addr_any(&fl6->saddr)) { 972 struct rt6_info *rt = (struct rt6_info *) *dst; 973 err = ip6_route_get_saddr(net, rt, &fl6->daddr, 974 sk ? inet6_sk(sk)->srcprefs : 0, 975 &fl6->saddr); 976 if (err) 977 goto out_err_release; 978 } 979 980 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD 981 /* 982 * Here if the dst entry we've looked up 983 * has a neighbour entry that is in the INCOMPLETE 984 * state and the src address from the flow is 985 * marked as OPTIMISTIC, we release the found 986 * dst entry and replace it instead with the 987 * dst entry of the nexthop router 988 */ 989 rcu_read_lock(); 990 n = dst_get_neighbour_noref(*dst); 991 if (n && !(n->nud_state & NUD_VALID)) { 992 struct inet6_ifaddr *ifp; 993 struct flowi6 fl_gw6; 994 int redirect; 995 996 rcu_read_unlock(); 997 ifp = ipv6_get_ifaddr(net, &fl6->saddr, 998 (*dst)->dev, 1); 999 1000 redirect = (ifp && ifp->flags & IFA_F_OPTIMISTIC); 1001 if (ifp) 1002 in6_ifa_put(ifp); 1003 1004 if (redirect) { 1005 /* 1006 * We need to get the dst entry for the 1007 * default router instead 1008 */ 1009 dst_release(*dst); 1010 memcpy(&fl_gw6, fl6, sizeof(struct flowi6)); 1011 memset(&fl_gw6.daddr, 0, sizeof(struct in6_addr)); 1012 *dst = ip6_route_output(net, sk, &fl_gw6); 1013 if ((err = (*dst)->error)) 1014 goto out_err_release; 1015 } 1016 } else { 1017 rcu_read_unlock(); 1018 } 1019 #endif 1020 1021 return 0; 1022 1023 out_err_release: 1024 if (err == -ENETUNREACH) 1025 IP6_INC_STATS_BH(net, NULL, IPSTATS_MIB_OUTNOROUTES); 1026 dst_release(*dst); 1027 *dst = NULL; 1028 return err; 1029 } 1030 1031 /** 1032 * ip6_dst_lookup - perform route lookup on flow 1033 * @sk: socket which provides route info 1034 * @dst: pointer to dst_entry * for result 1035 * @fl6: flow to lookup 1036 * 1037 * This function performs a route lookup on the given flow. 1038 * 1039 * It returns zero on success, or a standard errno code on error. 1040 */ 1041 int ip6_dst_lookup(struct sock *sk, struct dst_entry **dst, struct flowi6 *fl6) 1042 { 1043 *dst = NULL; 1044 return ip6_dst_lookup_tail(sk, dst, fl6); 1045 } 1046 EXPORT_SYMBOL_GPL(ip6_dst_lookup); 1047 1048 /** 1049 * ip6_dst_lookup_flow - perform route lookup on flow with ipsec 1050 * @sk: socket which provides route info 1051 * @fl6: flow to lookup 1052 * @final_dst: final destination address for ipsec lookup 1053 * @can_sleep: we are in a sleepable context 1054 * 1055 * This function performs a route lookup on the given flow. 1056 * 1057 * It returns a valid dst pointer on success, or a pointer encoded 1058 * error code. 1059 */ 1060 struct dst_entry *ip6_dst_lookup_flow(struct sock *sk, struct flowi6 *fl6, 1061 const struct in6_addr *final_dst, 1062 bool can_sleep) 1063 { 1064 struct dst_entry *dst = NULL; 1065 int err; 1066 1067 err = ip6_dst_lookup_tail(sk, &dst, fl6); 1068 if (err) 1069 return ERR_PTR(err); 1070 if (final_dst) 1071 fl6->daddr = *final_dst; 1072 if (can_sleep) 1073 fl6->flowi6_flags |= FLOWI_FLAG_CAN_SLEEP; 1074 1075 return xfrm_lookup(sock_net(sk), dst, flowi6_to_flowi(fl6), sk, 0); 1076 } 1077 EXPORT_SYMBOL_GPL(ip6_dst_lookup_flow); 1078 1079 /** 1080 * ip6_sk_dst_lookup_flow - perform socket cached route lookup on flow 1081 * @sk: socket which provides the dst cache and route info 1082 * @fl6: flow to lookup 1083 * @final_dst: final destination address for ipsec lookup 1084 * @can_sleep: we are in a sleepable context 1085 * 1086 * This function performs a route lookup on the given flow with the 1087 * possibility of using the cached route in the socket if it is valid. 1088 * It will take the socket dst lock when operating on the dst cache. 1089 * As a result, this function can only be used in process context. 1090 * 1091 * It returns a valid dst pointer on success, or a pointer encoded 1092 * error code. 1093 */ 1094 struct dst_entry *ip6_sk_dst_lookup_flow(struct sock *sk, struct flowi6 *fl6, 1095 const struct in6_addr *final_dst, 1096 bool can_sleep) 1097 { 1098 struct dst_entry *dst = sk_dst_check(sk, inet6_sk(sk)->dst_cookie); 1099 int err; 1100 1101 dst = ip6_sk_dst_check(sk, dst, fl6); 1102 1103 err = ip6_dst_lookup_tail(sk, &dst, fl6); 1104 if (err) 1105 return ERR_PTR(err); 1106 if (final_dst) 1107 fl6->daddr = *final_dst; 1108 if (can_sleep) 1109 fl6->flowi6_flags |= FLOWI_FLAG_CAN_SLEEP; 1110 1111 return xfrm_lookup(sock_net(sk), dst, flowi6_to_flowi(fl6), sk, 0); 1112 } 1113 EXPORT_SYMBOL_GPL(ip6_sk_dst_lookup_flow); 1114 1115 static inline int ip6_ufo_append_data(struct sock *sk, 1116 int getfrag(void *from, char *to, int offset, int len, 1117 int odd, struct sk_buff *skb), 1118 void *from, int length, int hh_len, int fragheaderlen, 1119 int transhdrlen, int mtu,unsigned int flags, 1120 struct rt6_info *rt) 1121 1122 { 1123 struct sk_buff *skb; 1124 int err; 1125 1126 /* There is support for UDP large send offload by network 1127 * device, so create one single skb packet containing complete 1128 * udp datagram 1129 */ 1130 if ((skb = skb_peek_tail(&sk->sk_write_queue)) == NULL) { 1131 skb = sock_alloc_send_skb(sk, 1132 hh_len + fragheaderlen + transhdrlen + 20, 1133 (flags & MSG_DONTWAIT), &err); 1134 if (skb == NULL) 1135 return err; 1136 1137 /* reserve space for Hardware header */ 1138 skb_reserve(skb, hh_len); 1139 1140 /* create space for UDP/IP header */ 1141 skb_put(skb,fragheaderlen + transhdrlen); 1142 1143 /* initialize network header pointer */ 1144 skb_reset_network_header(skb); 1145 1146 /* initialize protocol header pointer */ 1147 skb->transport_header = skb->network_header + fragheaderlen; 1148 1149 skb->ip_summed = CHECKSUM_PARTIAL; 1150 skb->csum = 0; 1151 } 1152 1153 err = skb_append_datato_frags(sk,skb, getfrag, from, 1154 (length - transhdrlen)); 1155 if (!err) { 1156 struct frag_hdr fhdr; 1157 1158 /* Specify the length of each IPv6 datagram fragment. 1159 * It has to be a multiple of 8. 1160 */ 1161 skb_shinfo(skb)->gso_size = (mtu - fragheaderlen - 1162 sizeof(struct frag_hdr)) & ~7; 1163 skb_shinfo(skb)->gso_type = SKB_GSO_UDP; 1164 ipv6_select_ident(&fhdr, rt); 1165 skb_shinfo(skb)->ip6_frag_id = fhdr.identification; 1166 __skb_queue_tail(&sk->sk_write_queue, skb); 1167 1168 return 0; 1169 } 1170 /* There is not enough support do UPD LSO, 1171 * so follow normal path 1172 */ 1173 kfree_skb(skb); 1174 1175 return err; 1176 } 1177 1178 static inline struct ipv6_opt_hdr *ip6_opt_dup(struct ipv6_opt_hdr *src, 1179 gfp_t gfp) 1180 { 1181 return src ? kmemdup(src, (src->hdrlen + 1) * 8, gfp) : NULL; 1182 } 1183 1184 static inline struct ipv6_rt_hdr *ip6_rthdr_dup(struct ipv6_rt_hdr *src, 1185 gfp_t gfp) 1186 { 1187 return src ? kmemdup(src, (src->hdrlen + 1) * 8, gfp) : NULL; 1188 } 1189 1190 int ip6_append_data(struct sock *sk, int getfrag(void *from, char *to, 1191 int offset, int len, int odd, struct sk_buff *skb), 1192 void *from, int length, int transhdrlen, 1193 int hlimit, int tclass, struct ipv6_txoptions *opt, struct flowi6 *fl6, 1194 struct rt6_info *rt, unsigned int flags, int dontfrag) 1195 { 1196 struct inet_sock *inet = inet_sk(sk); 1197 struct ipv6_pinfo *np = inet6_sk(sk); 1198 struct inet_cork *cork; 1199 struct sk_buff *skb; 1200 unsigned int maxfraglen, fragheaderlen; 1201 int exthdrlen; 1202 int dst_exthdrlen; 1203 int hh_len; 1204 int mtu; 1205 int copy; 1206 int err; 1207 int offset = 0; 1208 __u8 tx_flags = 0; 1209 1210 if (flags&MSG_PROBE) 1211 return 0; 1212 cork = &inet->cork.base; 1213 if (skb_queue_empty(&sk->sk_write_queue)) { 1214 /* 1215 * setup for corking 1216 */ 1217 if (opt) { 1218 if (WARN_ON(np->cork.opt)) 1219 return -EINVAL; 1220 1221 np->cork.opt = kmalloc(opt->tot_len, sk->sk_allocation); 1222 if (unlikely(np->cork.opt == NULL)) 1223 return -ENOBUFS; 1224 1225 np->cork.opt->tot_len = opt->tot_len; 1226 np->cork.opt->opt_flen = opt->opt_flen; 1227 np->cork.opt->opt_nflen = opt->opt_nflen; 1228 1229 np->cork.opt->dst0opt = ip6_opt_dup(opt->dst0opt, 1230 sk->sk_allocation); 1231 if (opt->dst0opt && !np->cork.opt->dst0opt) 1232 return -ENOBUFS; 1233 1234 np->cork.opt->dst1opt = ip6_opt_dup(opt->dst1opt, 1235 sk->sk_allocation); 1236 if (opt->dst1opt && !np->cork.opt->dst1opt) 1237 return -ENOBUFS; 1238 1239 np->cork.opt->hopopt = ip6_opt_dup(opt->hopopt, 1240 sk->sk_allocation); 1241 if (opt->hopopt && !np->cork.opt->hopopt) 1242 return -ENOBUFS; 1243 1244 np->cork.opt->srcrt = ip6_rthdr_dup(opt->srcrt, 1245 sk->sk_allocation); 1246 if (opt->srcrt && !np->cork.opt->srcrt) 1247 return -ENOBUFS; 1248 1249 /* need source address above miyazawa*/ 1250 } 1251 dst_hold(&rt->dst); 1252 cork->dst = &rt->dst; 1253 inet->cork.fl.u.ip6 = *fl6; 1254 np->cork.hop_limit = hlimit; 1255 np->cork.tclass = tclass; 1256 mtu = np->pmtudisc == IPV6_PMTUDISC_PROBE ? 1257 rt->dst.dev->mtu : dst_mtu(&rt->dst); 1258 if (np->frag_size < mtu) { 1259 if (np->frag_size) 1260 mtu = np->frag_size; 1261 } 1262 cork->fragsize = mtu; 1263 if (dst_allfrag(rt->dst.path)) 1264 cork->flags |= IPCORK_ALLFRAG; 1265 cork->length = 0; 1266 sk->sk_sndmsg_page = NULL; 1267 sk->sk_sndmsg_off = 0; 1268 exthdrlen = (opt ? opt->opt_flen : 0) - rt->rt6i_nfheader_len; 1269 length += exthdrlen; 1270 transhdrlen += exthdrlen; 1271 dst_exthdrlen = rt->dst.header_len; 1272 } else { 1273 rt = (struct rt6_info *)cork->dst; 1274 fl6 = &inet->cork.fl.u.ip6; 1275 opt = np->cork.opt; 1276 transhdrlen = 0; 1277 exthdrlen = 0; 1278 dst_exthdrlen = 0; 1279 mtu = cork->fragsize; 1280 } 1281 1282 hh_len = LL_RESERVED_SPACE(rt->dst.dev); 1283 1284 fragheaderlen = sizeof(struct ipv6hdr) + rt->rt6i_nfheader_len + 1285 (opt ? opt->opt_nflen : 0); 1286 maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen - sizeof(struct frag_hdr); 1287 1288 if (mtu <= sizeof(struct ipv6hdr) + IPV6_MAXPLEN) { 1289 if (cork->length + length > sizeof(struct ipv6hdr) + IPV6_MAXPLEN - fragheaderlen) { 1290 ipv6_local_error(sk, EMSGSIZE, fl6, mtu-exthdrlen); 1291 return -EMSGSIZE; 1292 } 1293 } 1294 1295 /* For UDP, check if TX timestamp is enabled */ 1296 if (sk->sk_type == SOCK_DGRAM) { 1297 err = sock_tx_timestamp(sk, &tx_flags); 1298 if (err) 1299 goto error; 1300 } 1301 1302 /* 1303 * Let's try using as much space as possible. 1304 * Use MTU if total length of the message fits into the MTU. 1305 * Otherwise, we need to reserve fragment header and 1306 * fragment alignment (= 8-15 octects, in total). 1307 * 1308 * Note that we may need to "move" the data from the tail of 1309 * of the buffer to the new fragment when we split 1310 * the message. 1311 * 1312 * FIXME: It may be fragmented into multiple chunks 1313 * at once if non-fragmentable extension headers 1314 * are too large. 1315 * --yoshfuji 1316 */ 1317 1318 cork->length += length; 1319 if (length > mtu) { 1320 int proto = sk->sk_protocol; 1321 if (dontfrag && (proto == IPPROTO_UDP || proto == IPPROTO_RAW)){ 1322 ipv6_local_rxpmtu(sk, fl6, mtu-exthdrlen); 1323 return -EMSGSIZE; 1324 } 1325 1326 if (proto == IPPROTO_UDP && 1327 (rt->dst.dev->features & NETIF_F_UFO)) { 1328 1329 err = ip6_ufo_append_data(sk, getfrag, from, length, 1330 hh_len, fragheaderlen, 1331 transhdrlen, mtu, flags, rt); 1332 if (err) 1333 goto error; 1334 return 0; 1335 } 1336 } 1337 1338 if ((skb = skb_peek_tail(&sk->sk_write_queue)) == NULL) 1339 goto alloc_new_skb; 1340 1341 while (length > 0) { 1342 /* Check if the remaining data fits into current packet. */ 1343 copy = (cork->length <= mtu && !(cork->flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - skb->len; 1344 if (copy < length) 1345 copy = maxfraglen - skb->len; 1346 1347 if (copy <= 0) { 1348 char *data; 1349 unsigned int datalen; 1350 unsigned int fraglen; 1351 unsigned int fraggap; 1352 unsigned int alloclen; 1353 struct sk_buff *skb_prev; 1354 alloc_new_skb: 1355 skb_prev = skb; 1356 1357 /* There's no room in the current skb */ 1358 if (skb_prev) 1359 fraggap = skb_prev->len - maxfraglen; 1360 else 1361 fraggap = 0; 1362 1363 /* 1364 * If remaining data exceeds the mtu, 1365 * we know we need more fragment(s). 1366 */ 1367 datalen = length + fraggap; 1368 if (datalen > (cork->length <= mtu && !(cork->flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - fragheaderlen) 1369 datalen = maxfraglen - fragheaderlen; 1370 1371 fraglen = datalen + fragheaderlen; 1372 if ((flags & MSG_MORE) && 1373 !(rt->dst.dev->features&NETIF_F_SG)) 1374 alloclen = mtu; 1375 else 1376 alloclen = datalen + fragheaderlen; 1377 1378 alloclen += dst_exthdrlen; 1379 1380 /* 1381 * The last fragment gets additional space at tail. 1382 * Note: we overallocate on fragments with MSG_MODE 1383 * because we have no idea if we're the last one. 1384 */ 1385 if (datalen == length + fraggap) 1386 alloclen += rt->dst.trailer_len; 1387 1388 /* 1389 * We just reserve space for fragment header. 1390 * Note: this may be overallocation if the message 1391 * (without MSG_MORE) fits into the MTU. 1392 */ 1393 alloclen += sizeof(struct frag_hdr); 1394 1395 if (transhdrlen) { 1396 skb = sock_alloc_send_skb(sk, 1397 alloclen + hh_len, 1398 (flags & MSG_DONTWAIT), &err); 1399 } else { 1400 skb = NULL; 1401 if (atomic_read(&sk->sk_wmem_alloc) <= 1402 2 * sk->sk_sndbuf) 1403 skb = sock_wmalloc(sk, 1404 alloclen + hh_len, 1, 1405 sk->sk_allocation); 1406 if (unlikely(skb == NULL)) 1407 err = -ENOBUFS; 1408 else { 1409 /* Only the initial fragment 1410 * is time stamped. 1411 */ 1412 tx_flags = 0; 1413 } 1414 } 1415 if (skb == NULL) 1416 goto error; 1417 /* 1418 * Fill in the control structures 1419 */ 1420 skb->ip_summed = CHECKSUM_NONE; 1421 skb->csum = 0; 1422 /* reserve for fragmentation and ipsec header */ 1423 skb_reserve(skb, hh_len + sizeof(struct frag_hdr) + 1424 dst_exthdrlen); 1425 1426 if (sk->sk_type == SOCK_DGRAM) 1427 skb_shinfo(skb)->tx_flags = tx_flags; 1428 1429 /* 1430 * Find where to start putting bytes 1431 */ 1432 data = skb_put(skb, fraglen); 1433 skb_set_network_header(skb, exthdrlen); 1434 data += fragheaderlen; 1435 skb->transport_header = (skb->network_header + 1436 fragheaderlen); 1437 if (fraggap) { 1438 skb->csum = skb_copy_and_csum_bits( 1439 skb_prev, maxfraglen, 1440 data + transhdrlen, fraggap, 0); 1441 skb_prev->csum = csum_sub(skb_prev->csum, 1442 skb->csum); 1443 data += fraggap; 1444 pskb_trim_unique(skb_prev, maxfraglen); 1445 } 1446 copy = datalen - transhdrlen - fraggap; 1447 1448 if (copy < 0) { 1449 err = -EINVAL; 1450 kfree_skb(skb); 1451 goto error; 1452 } else if (copy > 0 && getfrag(from, data + transhdrlen, offset, copy, fraggap, skb) < 0) { 1453 err = -EFAULT; 1454 kfree_skb(skb); 1455 goto error; 1456 } 1457 1458 offset += copy; 1459 length -= datalen - fraggap; 1460 transhdrlen = 0; 1461 exthdrlen = 0; 1462 dst_exthdrlen = 0; 1463 1464 /* 1465 * Put the packet on the pending queue 1466 */ 1467 __skb_queue_tail(&sk->sk_write_queue, skb); 1468 continue; 1469 } 1470 1471 if (copy > length) 1472 copy = length; 1473 1474 if (!(rt->dst.dev->features&NETIF_F_SG)) { 1475 unsigned int off; 1476 1477 off = skb->len; 1478 if (getfrag(from, skb_put(skb, copy), 1479 offset, copy, off, skb) < 0) { 1480 __skb_trim(skb, off); 1481 err = -EFAULT; 1482 goto error; 1483 } 1484 } else { 1485 int i = skb_shinfo(skb)->nr_frags; 1486 skb_frag_t *frag = &skb_shinfo(skb)->frags[i-1]; 1487 struct page *page = sk->sk_sndmsg_page; 1488 int off = sk->sk_sndmsg_off; 1489 unsigned int left; 1490 1491 if (page && (left = PAGE_SIZE - off) > 0) { 1492 if (copy >= left) 1493 copy = left; 1494 if (page != skb_frag_page(frag)) { 1495 if (i == MAX_SKB_FRAGS) { 1496 err = -EMSGSIZE; 1497 goto error; 1498 } 1499 skb_fill_page_desc(skb, i, page, sk->sk_sndmsg_off, 0); 1500 skb_frag_ref(skb, i); 1501 frag = &skb_shinfo(skb)->frags[i]; 1502 } 1503 } else if(i < MAX_SKB_FRAGS) { 1504 if (copy > PAGE_SIZE) 1505 copy = PAGE_SIZE; 1506 page = alloc_pages(sk->sk_allocation, 0); 1507 if (page == NULL) { 1508 err = -ENOMEM; 1509 goto error; 1510 } 1511 sk->sk_sndmsg_page = page; 1512 sk->sk_sndmsg_off = 0; 1513 1514 skb_fill_page_desc(skb, i, page, 0, 0); 1515 frag = &skb_shinfo(skb)->frags[i]; 1516 } else { 1517 err = -EMSGSIZE; 1518 goto error; 1519 } 1520 if (getfrag(from, 1521 skb_frag_address(frag) + skb_frag_size(frag), 1522 offset, copy, skb->len, skb) < 0) { 1523 err = -EFAULT; 1524 goto error; 1525 } 1526 sk->sk_sndmsg_off += copy; 1527 skb_frag_size_add(frag, copy); 1528 skb->len += copy; 1529 skb->data_len += copy; 1530 skb->truesize += copy; 1531 atomic_add(copy, &sk->sk_wmem_alloc); 1532 } 1533 offset += copy; 1534 length -= copy; 1535 } 1536 return 0; 1537 error: 1538 cork->length -= length; 1539 IP6_INC_STATS(sock_net(sk), rt->rt6i_idev, IPSTATS_MIB_OUTDISCARDS); 1540 return err; 1541 } 1542 EXPORT_SYMBOL_GPL(ip6_append_data); 1543 1544 static void ip6_cork_release(struct inet_sock *inet, struct ipv6_pinfo *np) 1545 { 1546 if (np->cork.opt) { 1547 kfree(np->cork.opt->dst0opt); 1548 kfree(np->cork.opt->dst1opt); 1549 kfree(np->cork.opt->hopopt); 1550 kfree(np->cork.opt->srcrt); 1551 kfree(np->cork.opt); 1552 np->cork.opt = NULL; 1553 } 1554 1555 if (inet->cork.base.dst) { 1556 dst_release(inet->cork.base.dst); 1557 inet->cork.base.dst = NULL; 1558 inet->cork.base.flags &= ~IPCORK_ALLFRAG; 1559 } 1560 memset(&inet->cork.fl, 0, sizeof(inet->cork.fl)); 1561 } 1562 1563 int ip6_push_pending_frames(struct sock *sk) 1564 { 1565 struct sk_buff *skb, *tmp_skb; 1566 struct sk_buff **tail_skb; 1567 struct in6_addr final_dst_buf, *final_dst = &final_dst_buf; 1568 struct inet_sock *inet = inet_sk(sk); 1569 struct ipv6_pinfo *np = inet6_sk(sk); 1570 struct net *net = sock_net(sk); 1571 struct ipv6hdr *hdr; 1572 struct ipv6_txoptions *opt = np->cork.opt; 1573 struct rt6_info *rt = (struct rt6_info *)inet->cork.base.dst; 1574 struct flowi6 *fl6 = &inet->cork.fl.u.ip6; 1575 unsigned char proto = fl6->flowi6_proto; 1576 int err = 0; 1577 1578 if ((skb = __skb_dequeue(&sk->sk_write_queue)) == NULL) 1579 goto out; 1580 tail_skb = &(skb_shinfo(skb)->frag_list); 1581 1582 /* move skb->data to ip header from ext header */ 1583 if (skb->data < skb_network_header(skb)) 1584 __skb_pull(skb, skb_network_offset(skb)); 1585 while ((tmp_skb = __skb_dequeue(&sk->sk_write_queue)) != NULL) { 1586 __skb_pull(tmp_skb, skb_network_header_len(skb)); 1587 *tail_skb = tmp_skb; 1588 tail_skb = &(tmp_skb->next); 1589 skb->len += tmp_skb->len; 1590 skb->data_len += tmp_skb->len; 1591 skb->truesize += tmp_skb->truesize; 1592 tmp_skb->destructor = NULL; 1593 tmp_skb->sk = NULL; 1594 } 1595 1596 /* Allow local fragmentation. */ 1597 if (np->pmtudisc < IPV6_PMTUDISC_DO) 1598 skb->local_df = 1; 1599 1600 *final_dst = fl6->daddr; 1601 __skb_pull(skb, skb_network_header_len(skb)); 1602 if (opt && opt->opt_flen) 1603 ipv6_push_frag_opts(skb, opt, &proto); 1604 if (opt && opt->opt_nflen) 1605 ipv6_push_nfrag_opts(skb, opt, &proto, &final_dst); 1606 1607 skb_push(skb, sizeof(struct ipv6hdr)); 1608 skb_reset_network_header(skb); 1609 hdr = ipv6_hdr(skb); 1610 1611 *(__be32*)hdr = fl6->flowlabel | 1612 htonl(0x60000000 | ((int)np->cork.tclass << 20)); 1613 1614 hdr->hop_limit = np->cork.hop_limit; 1615 hdr->nexthdr = proto; 1616 hdr->saddr = fl6->saddr; 1617 hdr->daddr = *final_dst; 1618 1619 skb->priority = sk->sk_priority; 1620 skb->mark = sk->sk_mark; 1621 1622 skb_dst_set(skb, dst_clone(&rt->dst)); 1623 IP6_UPD_PO_STATS(net, rt->rt6i_idev, IPSTATS_MIB_OUT, skb->len); 1624 if (proto == IPPROTO_ICMPV6) { 1625 struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb)); 1626 1627 ICMP6MSGOUT_INC_STATS_BH(net, idev, icmp6_hdr(skb)->icmp6_type); 1628 ICMP6_INC_STATS_BH(net, idev, ICMP6_MIB_OUTMSGS); 1629 } 1630 1631 err = ip6_local_out(skb); 1632 if (err) { 1633 if (err > 0) 1634 err = net_xmit_errno(err); 1635 if (err) 1636 goto error; 1637 } 1638 1639 out: 1640 ip6_cork_release(inet, np); 1641 return err; 1642 error: 1643 IP6_INC_STATS(net, rt->rt6i_idev, IPSTATS_MIB_OUTDISCARDS); 1644 goto out; 1645 } 1646 EXPORT_SYMBOL_GPL(ip6_push_pending_frames); 1647 1648 void ip6_flush_pending_frames(struct sock *sk) 1649 { 1650 struct sk_buff *skb; 1651 1652 while ((skb = __skb_dequeue_tail(&sk->sk_write_queue)) != NULL) { 1653 if (skb_dst(skb)) 1654 IP6_INC_STATS(sock_net(sk), ip6_dst_idev(skb_dst(skb)), 1655 IPSTATS_MIB_OUTDISCARDS); 1656 kfree_skb(skb); 1657 } 1658 1659 ip6_cork_release(inet_sk(sk), inet6_sk(sk)); 1660 } 1661 EXPORT_SYMBOL_GPL(ip6_flush_pending_frames); 1662