1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * IPv6 output functions 4 * Linux INET6 implementation 5 * 6 * Authors: 7 * Pedro Roque <roque@di.fc.ul.pt> 8 * 9 * Based on linux/net/ipv4/ip_output.c 10 * 11 * Changes: 12 * A.N.Kuznetsov : airthmetics in fragmentation. 13 * extension headers are implemented. 14 * route changes now work. 15 * ip6_forward does not confuse sniffers. 16 * etc. 17 * 18 * H. von Brand : Added missing #include <linux/string.h> 19 * Imran Patel : frag id should be in NBO 20 * Kazunori MIYAZAWA @USAGI 21 * : add ip6_append_data and related functions 22 * for datagram xmit 23 */ 24 25 #include <linux/errno.h> 26 #include <linux/kernel.h> 27 #include <linux/string.h> 28 #include <linux/socket.h> 29 #include <linux/net.h> 30 #include <linux/netdevice.h> 31 #include <linux/if_arp.h> 32 #include <linux/in6.h> 33 #include <linux/tcp.h> 34 #include <linux/route.h> 35 #include <linux/module.h> 36 #include <linux/slab.h> 37 38 #include <linux/bpf-cgroup.h> 39 #include <linux/netfilter.h> 40 #include <linux/netfilter_ipv6.h> 41 42 #include <net/sock.h> 43 #include <net/snmp.h> 44 45 #include <net/ipv6.h> 46 #include <net/ndisc.h> 47 #include <net/protocol.h> 48 #include <net/ip6_route.h> 49 #include <net/addrconf.h> 50 #include <net/rawv6.h> 51 #include <net/icmp.h> 52 #include <net/xfrm.h> 53 #include <net/checksum.h> 54 #include <linux/mroute6.h> 55 #include <net/l3mdev.h> 56 #include <net/lwtunnel.h> 57 #include <net/ip_tunnels.h> 58 59 static int ip6_finish_output2(struct net *net, struct sock *sk, struct sk_buff *skb) 60 { 61 struct dst_entry *dst = skb_dst(skb); 62 struct net_device *dev = dst->dev; 63 struct inet6_dev *idev = ip6_dst_idev(dst); 64 unsigned int hh_len = LL_RESERVED_SPACE(dev); 65 const struct in6_addr *daddr, *nexthop; 66 struct ipv6hdr *hdr; 67 struct neighbour *neigh; 68 int ret; 69 70 /* Be paranoid, rather than too clever. */ 71 if (unlikely(hh_len > skb_headroom(skb)) && dev->header_ops) { 72 skb = skb_expand_head(skb, hh_len); 73 if (!skb) { 74 IP6_INC_STATS(net, idev, IPSTATS_MIB_OUTDISCARDS); 75 return -ENOMEM; 76 } 77 } 78 79 hdr = ipv6_hdr(skb); 80 daddr = &hdr->daddr; 81 if (ipv6_addr_is_multicast(daddr)) { 82 if (!(dev->flags & IFF_LOOPBACK) && sk_mc_loop(sk) && 83 ((mroute6_is_socket(net, skb) && 84 !(IP6CB(skb)->flags & IP6SKB_FORWARDED)) || 85 ipv6_chk_mcast_addr(dev, daddr, &hdr->saddr))) { 86 struct sk_buff *newskb = skb_clone(skb, GFP_ATOMIC); 87 88 /* Do not check for IFF_ALLMULTI; multicast routing 89 is not supported in any case. 90 */ 91 if (newskb) 92 NF_HOOK(NFPROTO_IPV6, NF_INET_POST_ROUTING, 93 net, sk, newskb, NULL, newskb->dev, 94 dev_loopback_xmit); 95 96 if (hdr->hop_limit == 0) { 97 IP6_INC_STATS(net, idev, 98 IPSTATS_MIB_OUTDISCARDS); 99 kfree_skb(skb); 100 return 0; 101 } 102 } 103 104 IP6_UPD_PO_STATS(net, idev, IPSTATS_MIB_OUTMCAST, skb->len); 105 if (IPV6_ADDR_MC_SCOPE(daddr) <= IPV6_ADDR_SCOPE_NODELOCAL && 106 !(dev->flags & IFF_LOOPBACK)) { 107 kfree_skb(skb); 108 return 0; 109 } 110 } 111 112 if (lwtunnel_xmit_redirect(dst->lwtstate)) { 113 int res = lwtunnel_xmit(skb); 114 115 if (res < 0 || res == LWTUNNEL_XMIT_DONE) 116 return res; 117 } 118 119 rcu_read_lock_bh(); 120 nexthop = rt6_nexthop((struct rt6_info *)dst, daddr); 121 neigh = __ipv6_neigh_lookup_noref(dev, nexthop); 122 if (unlikely(!neigh)) 123 neigh = __neigh_create(&nd_tbl, nexthop, dev, false); 124 if (!IS_ERR(neigh)) { 125 sock_confirm_neigh(skb, neigh); 126 ret = neigh_output(neigh, skb, false); 127 rcu_read_unlock_bh(); 128 return ret; 129 } 130 rcu_read_unlock_bh(); 131 132 IP6_INC_STATS(net, idev, IPSTATS_MIB_OUTNOROUTES); 133 kfree_skb(skb); 134 return -EINVAL; 135 } 136 137 static int 138 ip6_finish_output_gso_slowpath_drop(struct net *net, struct sock *sk, 139 struct sk_buff *skb, unsigned int mtu) 140 { 141 struct sk_buff *segs, *nskb; 142 netdev_features_t features; 143 int ret = 0; 144 145 /* Please see corresponding comment in ip_finish_output_gso 146 * describing the cases where GSO segment length exceeds the 147 * egress MTU. 148 */ 149 features = netif_skb_features(skb); 150 segs = skb_gso_segment(skb, features & ~NETIF_F_GSO_MASK); 151 if (IS_ERR_OR_NULL(segs)) { 152 kfree_skb(skb); 153 return -ENOMEM; 154 } 155 156 consume_skb(skb); 157 158 skb_list_walk_safe(segs, segs, nskb) { 159 int err; 160 161 skb_mark_not_on_list(segs); 162 err = ip6_fragment(net, sk, segs, ip6_finish_output2); 163 if (err && ret == 0) 164 ret = err; 165 } 166 167 return ret; 168 } 169 170 static int __ip6_finish_output(struct net *net, struct sock *sk, struct sk_buff *skb) 171 { 172 unsigned int mtu; 173 174 #if defined(CONFIG_NETFILTER) && defined(CONFIG_XFRM) 175 /* Policy lookup after SNAT yielded a new policy */ 176 if (skb_dst(skb)->xfrm) { 177 IP6CB(skb)->flags |= IP6SKB_REROUTED; 178 return dst_output(net, sk, skb); 179 } 180 #endif 181 182 mtu = ip6_skb_dst_mtu(skb); 183 if (skb_is_gso(skb) && !skb_gso_validate_network_len(skb, mtu)) 184 return ip6_finish_output_gso_slowpath_drop(net, sk, skb, mtu); 185 186 if ((skb->len > mtu && !skb_is_gso(skb)) || 187 dst_allfrag(skb_dst(skb)) || 188 (IP6CB(skb)->frag_max_size && skb->len > IP6CB(skb)->frag_max_size)) 189 return ip6_fragment(net, sk, skb, ip6_finish_output2); 190 else 191 return ip6_finish_output2(net, sk, skb); 192 } 193 194 static int ip6_finish_output(struct net *net, struct sock *sk, struct sk_buff *skb) 195 { 196 int ret; 197 198 ret = BPF_CGROUP_RUN_PROG_INET_EGRESS(sk, skb); 199 switch (ret) { 200 case NET_XMIT_SUCCESS: 201 return __ip6_finish_output(net, sk, skb); 202 case NET_XMIT_CN: 203 return __ip6_finish_output(net, sk, skb) ? : ret; 204 default: 205 kfree_skb(skb); 206 return ret; 207 } 208 } 209 210 int ip6_output(struct net *net, struct sock *sk, struct sk_buff *skb) 211 { 212 struct net_device *dev = skb_dst(skb)->dev, *indev = skb->dev; 213 struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb)); 214 215 skb->protocol = htons(ETH_P_IPV6); 216 skb->dev = dev; 217 218 if (unlikely(idev->cnf.disable_ipv6)) { 219 IP6_INC_STATS(net, idev, IPSTATS_MIB_OUTDISCARDS); 220 kfree_skb(skb); 221 return 0; 222 } 223 224 return NF_HOOK_COND(NFPROTO_IPV6, NF_INET_POST_ROUTING, 225 net, sk, skb, indev, dev, 226 ip6_finish_output, 227 !(IP6CB(skb)->flags & IP6SKB_REROUTED)); 228 } 229 EXPORT_SYMBOL(ip6_output); 230 231 bool ip6_autoflowlabel(struct net *net, const struct ipv6_pinfo *np) 232 { 233 if (!np->autoflowlabel_set) 234 return ip6_default_np_autolabel(net); 235 else 236 return np->autoflowlabel; 237 } 238 239 /* 240 * xmit an sk_buff (used by TCP, SCTP and DCCP) 241 * Note : socket lock is not held for SYNACK packets, but might be modified 242 * by calls to skb_set_owner_w() and ipv6_local_error(), 243 * which are using proper atomic operations or spinlocks. 244 */ 245 int ip6_xmit(const struct sock *sk, struct sk_buff *skb, struct flowi6 *fl6, 246 __u32 mark, struct ipv6_txoptions *opt, int tclass, u32 priority) 247 { 248 struct net *net = sock_net(sk); 249 const struct ipv6_pinfo *np = inet6_sk(sk); 250 struct in6_addr *first_hop = &fl6->daddr; 251 struct dst_entry *dst = skb_dst(skb); 252 struct net_device *dev = dst->dev; 253 struct inet6_dev *idev = ip6_dst_idev(dst); 254 unsigned int head_room; 255 struct ipv6hdr *hdr; 256 u8 proto = fl6->flowi6_proto; 257 int seg_len = skb->len; 258 int hlimit = -1; 259 u32 mtu; 260 261 head_room = sizeof(struct ipv6hdr) + LL_RESERVED_SPACE(dev); 262 if (opt) 263 head_room += opt->opt_nflen + opt->opt_flen; 264 265 if (unlikely(head_room > skb_headroom(skb))) { 266 skb = skb_expand_head(skb, head_room); 267 if (!skb) { 268 IP6_INC_STATS(net, idev, IPSTATS_MIB_OUTDISCARDS); 269 return -ENOBUFS; 270 } 271 } 272 273 if (opt) { 274 seg_len += opt->opt_nflen + opt->opt_flen; 275 276 if (opt->opt_flen) 277 ipv6_push_frag_opts(skb, opt, &proto); 278 279 if (opt->opt_nflen) 280 ipv6_push_nfrag_opts(skb, opt, &proto, &first_hop, 281 &fl6->saddr); 282 } 283 284 skb_push(skb, sizeof(struct ipv6hdr)); 285 skb_reset_network_header(skb); 286 hdr = ipv6_hdr(skb); 287 288 /* 289 * Fill in the IPv6 header 290 */ 291 if (np) 292 hlimit = np->hop_limit; 293 if (hlimit < 0) 294 hlimit = ip6_dst_hoplimit(dst); 295 296 ip6_flow_hdr(hdr, tclass, ip6_make_flowlabel(net, skb, fl6->flowlabel, 297 ip6_autoflowlabel(net, np), fl6)); 298 299 hdr->payload_len = htons(seg_len); 300 hdr->nexthdr = proto; 301 hdr->hop_limit = hlimit; 302 303 hdr->saddr = fl6->saddr; 304 hdr->daddr = *first_hop; 305 306 skb->protocol = htons(ETH_P_IPV6); 307 skb->priority = priority; 308 skb->mark = mark; 309 310 mtu = dst_mtu(dst); 311 if ((skb->len <= mtu) || skb->ignore_df || skb_is_gso(skb)) { 312 IP6_UPD_PO_STATS(net, idev, IPSTATS_MIB_OUT, skb->len); 313 314 /* if egress device is enslaved to an L3 master device pass the 315 * skb to its handler for processing 316 */ 317 skb = l3mdev_ip6_out((struct sock *)sk, skb); 318 if (unlikely(!skb)) 319 return 0; 320 321 /* hooks should never assume socket lock is held. 322 * we promote our socket to non const 323 */ 324 return NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT, 325 net, (struct sock *)sk, skb, NULL, dev, 326 dst_output); 327 } 328 329 skb->dev = dev; 330 /* ipv6_local_error() does not require socket lock, 331 * we promote our socket to non const 332 */ 333 ipv6_local_error((struct sock *)sk, EMSGSIZE, fl6, mtu); 334 335 IP6_INC_STATS(net, idev, IPSTATS_MIB_FRAGFAILS); 336 kfree_skb(skb); 337 return -EMSGSIZE; 338 } 339 EXPORT_SYMBOL(ip6_xmit); 340 341 static int ip6_call_ra_chain(struct sk_buff *skb, int sel) 342 { 343 struct ip6_ra_chain *ra; 344 struct sock *last = NULL; 345 346 read_lock(&ip6_ra_lock); 347 for (ra = ip6_ra_chain; ra; ra = ra->next) { 348 struct sock *sk = ra->sk; 349 if (sk && ra->sel == sel && 350 (!sk->sk_bound_dev_if || 351 sk->sk_bound_dev_if == skb->dev->ifindex)) { 352 struct ipv6_pinfo *np = inet6_sk(sk); 353 354 if (np && np->rtalert_isolate && 355 !net_eq(sock_net(sk), dev_net(skb->dev))) { 356 continue; 357 } 358 if (last) { 359 struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC); 360 if (skb2) 361 rawv6_rcv(last, skb2); 362 } 363 last = sk; 364 } 365 } 366 367 if (last) { 368 rawv6_rcv(last, skb); 369 read_unlock(&ip6_ra_lock); 370 return 1; 371 } 372 read_unlock(&ip6_ra_lock); 373 return 0; 374 } 375 376 static int ip6_forward_proxy_check(struct sk_buff *skb) 377 { 378 struct ipv6hdr *hdr = ipv6_hdr(skb); 379 u8 nexthdr = hdr->nexthdr; 380 __be16 frag_off; 381 int offset; 382 383 if (ipv6_ext_hdr(nexthdr)) { 384 offset = ipv6_skip_exthdr(skb, sizeof(*hdr), &nexthdr, &frag_off); 385 if (offset < 0) 386 return 0; 387 } else 388 offset = sizeof(struct ipv6hdr); 389 390 if (nexthdr == IPPROTO_ICMPV6) { 391 struct icmp6hdr *icmp6; 392 393 if (!pskb_may_pull(skb, (skb_network_header(skb) + 394 offset + 1 - skb->data))) 395 return 0; 396 397 icmp6 = (struct icmp6hdr *)(skb_network_header(skb) + offset); 398 399 switch (icmp6->icmp6_type) { 400 case NDISC_ROUTER_SOLICITATION: 401 case NDISC_ROUTER_ADVERTISEMENT: 402 case NDISC_NEIGHBOUR_SOLICITATION: 403 case NDISC_NEIGHBOUR_ADVERTISEMENT: 404 case NDISC_REDIRECT: 405 /* For reaction involving unicast neighbor discovery 406 * message destined to the proxied address, pass it to 407 * input function. 408 */ 409 return 1; 410 default: 411 break; 412 } 413 } 414 415 /* 416 * The proxying router can't forward traffic sent to a link-local 417 * address, so signal the sender and discard the packet. This 418 * behavior is clarified by the MIPv6 specification. 419 */ 420 if (ipv6_addr_type(&hdr->daddr) & IPV6_ADDR_LINKLOCAL) { 421 dst_link_failure(skb); 422 return -1; 423 } 424 425 return 0; 426 } 427 428 static inline int ip6_forward_finish(struct net *net, struct sock *sk, 429 struct sk_buff *skb) 430 { 431 struct dst_entry *dst = skb_dst(skb); 432 433 __IP6_INC_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTFORWDATAGRAMS); 434 __IP6_ADD_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTOCTETS, skb->len); 435 436 #ifdef CONFIG_NET_SWITCHDEV 437 if (skb->offload_l3_fwd_mark) { 438 consume_skb(skb); 439 return 0; 440 } 441 #endif 442 443 skb->tstamp = 0; 444 return dst_output(net, sk, skb); 445 } 446 447 static bool ip6_pkt_too_big(const struct sk_buff *skb, unsigned int mtu) 448 { 449 if (skb->len <= mtu) 450 return false; 451 452 /* ipv6 conntrack defrag sets max_frag_size + ignore_df */ 453 if (IP6CB(skb)->frag_max_size && IP6CB(skb)->frag_max_size > mtu) 454 return true; 455 456 if (skb->ignore_df) 457 return false; 458 459 if (skb_is_gso(skb) && skb_gso_validate_network_len(skb, mtu)) 460 return false; 461 462 return true; 463 } 464 465 int ip6_forward(struct sk_buff *skb) 466 { 467 struct dst_entry *dst = skb_dst(skb); 468 struct ipv6hdr *hdr = ipv6_hdr(skb); 469 struct inet6_skb_parm *opt = IP6CB(skb); 470 struct net *net = dev_net(dst->dev); 471 struct inet6_dev *idev; 472 u32 mtu; 473 474 idev = __in6_dev_get_safely(dev_get_by_index_rcu(net, IP6CB(skb)->iif)); 475 if (net->ipv6.devconf_all->forwarding == 0) 476 goto error; 477 478 if (skb->pkt_type != PACKET_HOST) 479 goto drop; 480 481 if (unlikely(skb->sk)) 482 goto drop; 483 484 if (skb_warn_if_lro(skb)) 485 goto drop; 486 487 if (!net->ipv6.devconf_all->disable_policy && 488 !idev->cnf.disable_policy && 489 !xfrm6_policy_check(NULL, XFRM_POLICY_FWD, skb)) { 490 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INDISCARDS); 491 goto drop; 492 } 493 494 skb_forward_csum(skb); 495 496 /* 497 * We DO NOT make any processing on 498 * RA packets, pushing them to user level AS IS 499 * without ane WARRANTY that application will be able 500 * to interpret them. The reason is that we 501 * cannot make anything clever here. 502 * 503 * We are not end-node, so that if packet contains 504 * AH/ESP, we cannot make anything. 505 * Defragmentation also would be mistake, RA packets 506 * cannot be fragmented, because there is no warranty 507 * that different fragments will go along one path. --ANK 508 */ 509 if (unlikely(opt->flags & IP6SKB_ROUTERALERT)) { 510 if (ip6_call_ra_chain(skb, ntohs(opt->ra))) 511 return 0; 512 } 513 514 /* 515 * check and decrement ttl 516 */ 517 if (hdr->hop_limit <= 1) { 518 icmpv6_send(skb, ICMPV6_TIME_EXCEED, ICMPV6_EXC_HOPLIMIT, 0); 519 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); 520 521 kfree_skb(skb); 522 return -ETIMEDOUT; 523 } 524 525 /* XXX: idev->cnf.proxy_ndp? */ 526 if (net->ipv6.devconf_all->proxy_ndp && 527 pneigh_lookup(&nd_tbl, net, &hdr->daddr, skb->dev, 0)) { 528 int proxied = ip6_forward_proxy_check(skb); 529 if (proxied > 0) { 530 hdr->hop_limit--; 531 return ip6_input(skb); 532 } else if (proxied < 0) { 533 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INDISCARDS); 534 goto drop; 535 } 536 } 537 538 if (!xfrm6_route_forward(skb)) { 539 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INDISCARDS); 540 goto drop; 541 } 542 dst = skb_dst(skb); 543 544 /* IPv6 specs say nothing about it, but it is clear that we cannot 545 send redirects to source routed frames. 546 We don't send redirects to frames decapsulated from IPsec. 547 */ 548 if (IP6CB(skb)->iif == dst->dev->ifindex && 549 opt->srcrt == 0 && !skb_sec_path(skb)) { 550 struct in6_addr *target = NULL; 551 struct inet_peer *peer; 552 struct rt6_info *rt; 553 554 /* 555 * incoming and outgoing devices are the same 556 * send a redirect. 557 */ 558 559 rt = (struct rt6_info *) dst; 560 if (rt->rt6i_flags & RTF_GATEWAY) 561 target = &rt->rt6i_gateway; 562 else 563 target = &hdr->daddr; 564 565 peer = inet_getpeer_v6(net->ipv6.peers, &hdr->daddr, 1); 566 567 /* Limit redirects both by destination (here) 568 and by source (inside ndisc_send_redirect) 569 */ 570 if (inet_peer_xrlim_allow(peer, 1*HZ)) 571 ndisc_send_redirect(skb, target); 572 if (peer) 573 inet_putpeer(peer); 574 } else { 575 int addrtype = ipv6_addr_type(&hdr->saddr); 576 577 /* This check is security critical. */ 578 if (addrtype == IPV6_ADDR_ANY || 579 addrtype & (IPV6_ADDR_MULTICAST | IPV6_ADDR_LOOPBACK)) 580 goto error; 581 if (addrtype & IPV6_ADDR_LINKLOCAL) { 582 icmpv6_send(skb, ICMPV6_DEST_UNREACH, 583 ICMPV6_NOT_NEIGHBOUR, 0); 584 goto error; 585 } 586 } 587 588 mtu = ip6_dst_mtu_maybe_forward(dst, true); 589 if (mtu < IPV6_MIN_MTU) 590 mtu = IPV6_MIN_MTU; 591 592 if (ip6_pkt_too_big(skb, mtu)) { 593 /* Again, force OUTPUT device used as source address */ 594 skb->dev = dst->dev; 595 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu); 596 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INTOOBIGERRORS); 597 __IP6_INC_STATS(net, ip6_dst_idev(dst), 598 IPSTATS_MIB_FRAGFAILS); 599 kfree_skb(skb); 600 return -EMSGSIZE; 601 } 602 603 if (skb_cow(skb, dst->dev->hard_header_len)) { 604 __IP6_INC_STATS(net, ip6_dst_idev(dst), 605 IPSTATS_MIB_OUTDISCARDS); 606 goto drop; 607 } 608 609 hdr = ipv6_hdr(skb); 610 611 /* Mangling hops number delayed to point after skb COW */ 612 613 hdr->hop_limit--; 614 615 return NF_HOOK(NFPROTO_IPV6, NF_INET_FORWARD, 616 net, NULL, skb, skb->dev, dst->dev, 617 ip6_forward_finish); 618 619 error: 620 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INADDRERRORS); 621 drop: 622 kfree_skb(skb); 623 return -EINVAL; 624 } 625 626 static void ip6_copy_metadata(struct sk_buff *to, struct sk_buff *from) 627 { 628 to->pkt_type = from->pkt_type; 629 to->priority = from->priority; 630 to->protocol = from->protocol; 631 skb_dst_drop(to); 632 skb_dst_set(to, dst_clone(skb_dst(from))); 633 to->dev = from->dev; 634 to->mark = from->mark; 635 636 skb_copy_hash(to, from); 637 638 #ifdef CONFIG_NET_SCHED 639 to->tc_index = from->tc_index; 640 #endif 641 nf_copy(to, from); 642 skb_ext_copy(to, from); 643 skb_copy_secmark(to, from); 644 } 645 646 int ip6_fraglist_init(struct sk_buff *skb, unsigned int hlen, u8 *prevhdr, 647 u8 nexthdr, __be32 frag_id, 648 struct ip6_fraglist_iter *iter) 649 { 650 unsigned int first_len; 651 struct frag_hdr *fh; 652 653 /* BUILD HEADER */ 654 *prevhdr = NEXTHDR_FRAGMENT; 655 iter->tmp_hdr = kmemdup(skb_network_header(skb), hlen, GFP_ATOMIC); 656 if (!iter->tmp_hdr) 657 return -ENOMEM; 658 659 iter->frag = skb_shinfo(skb)->frag_list; 660 skb_frag_list_init(skb); 661 662 iter->offset = 0; 663 iter->hlen = hlen; 664 iter->frag_id = frag_id; 665 iter->nexthdr = nexthdr; 666 667 __skb_pull(skb, hlen); 668 fh = __skb_push(skb, sizeof(struct frag_hdr)); 669 __skb_push(skb, hlen); 670 skb_reset_network_header(skb); 671 memcpy(skb_network_header(skb), iter->tmp_hdr, hlen); 672 673 fh->nexthdr = nexthdr; 674 fh->reserved = 0; 675 fh->frag_off = htons(IP6_MF); 676 fh->identification = frag_id; 677 678 first_len = skb_pagelen(skb); 679 skb->data_len = first_len - skb_headlen(skb); 680 skb->len = first_len; 681 ipv6_hdr(skb)->payload_len = htons(first_len - sizeof(struct ipv6hdr)); 682 683 return 0; 684 } 685 EXPORT_SYMBOL(ip6_fraglist_init); 686 687 void ip6_fraglist_prepare(struct sk_buff *skb, 688 struct ip6_fraglist_iter *iter) 689 { 690 struct sk_buff *frag = iter->frag; 691 unsigned int hlen = iter->hlen; 692 struct frag_hdr *fh; 693 694 frag->ip_summed = CHECKSUM_NONE; 695 skb_reset_transport_header(frag); 696 fh = __skb_push(frag, sizeof(struct frag_hdr)); 697 __skb_push(frag, hlen); 698 skb_reset_network_header(frag); 699 memcpy(skb_network_header(frag), iter->tmp_hdr, hlen); 700 iter->offset += skb->len - hlen - sizeof(struct frag_hdr); 701 fh->nexthdr = iter->nexthdr; 702 fh->reserved = 0; 703 fh->frag_off = htons(iter->offset); 704 if (frag->next) 705 fh->frag_off |= htons(IP6_MF); 706 fh->identification = iter->frag_id; 707 ipv6_hdr(frag)->payload_len = htons(frag->len - sizeof(struct ipv6hdr)); 708 ip6_copy_metadata(frag, skb); 709 } 710 EXPORT_SYMBOL(ip6_fraglist_prepare); 711 712 void ip6_frag_init(struct sk_buff *skb, unsigned int hlen, unsigned int mtu, 713 unsigned short needed_tailroom, int hdr_room, u8 *prevhdr, 714 u8 nexthdr, __be32 frag_id, struct ip6_frag_state *state) 715 { 716 state->prevhdr = prevhdr; 717 state->nexthdr = nexthdr; 718 state->frag_id = frag_id; 719 720 state->hlen = hlen; 721 state->mtu = mtu; 722 723 state->left = skb->len - hlen; /* Space per frame */ 724 state->ptr = hlen; /* Where to start from */ 725 726 state->hroom = hdr_room; 727 state->troom = needed_tailroom; 728 729 state->offset = 0; 730 } 731 EXPORT_SYMBOL(ip6_frag_init); 732 733 struct sk_buff *ip6_frag_next(struct sk_buff *skb, struct ip6_frag_state *state) 734 { 735 u8 *prevhdr = state->prevhdr, *fragnexthdr_offset; 736 struct sk_buff *frag; 737 struct frag_hdr *fh; 738 unsigned int len; 739 740 len = state->left; 741 /* IF: it doesn't fit, use 'mtu' - the data space left */ 742 if (len > state->mtu) 743 len = state->mtu; 744 /* IF: we are not sending up to and including the packet end 745 then align the next start on an eight byte boundary */ 746 if (len < state->left) 747 len &= ~7; 748 749 /* Allocate buffer */ 750 frag = alloc_skb(len + state->hlen + sizeof(struct frag_hdr) + 751 state->hroom + state->troom, GFP_ATOMIC); 752 if (!frag) 753 return ERR_PTR(-ENOMEM); 754 755 /* 756 * Set up data on packet 757 */ 758 759 ip6_copy_metadata(frag, skb); 760 skb_reserve(frag, state->hroom); 761 skb_put(frag, len + state->hlen + sizeof(struct frag_hdr)); 762 skb_reset_network_header(frag); 763 fh = (struct frag_hdr *)(skb_network_header(frag) + state->hlen); 764 frag->transport_header = (frag->network_header + state->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), state->hlen); 778 779 fragnexthdr_offset = skb_network_header(frag); 780 fragnexthdr_offset += prevhdr - skb_network_header(skb); 781 *fragnexthdr_offset = NEXTHDR_FRAGMENT; 782 783 /* 784 * Build fragment header. 785 */ 786 fh->nexthdr = state->nexthdr; 787 fh->reserved = 0; 788 fh->identification = state->frag_id; 789 790 /* 791 * Copy a block of the IP datagram. 792 */ 793 BUG_ON(skb_copy_bits(skb, state->ptr, skb_transport_header(frag), 794 len)); 795 state->left -= len; 796 797 fh->frag_off = htons(state->offset); 798 if (state->left > 0) 799 fh->frag_off |= htons(IP6_MF); 800 ipv6_hdr(frag)->payload_len = htons(frag->len - sizeof(struct ipv6hdr)); 801 802 state->ptr += len; 803 state->offset += len; 804 805 return frag; 806 } 807 EXPORT_SYMBOL(ip6_frag_next); 808 809 int ip6_fragment(struct net *net, struct sock *sk, struct sk_buff *skb, 810 int (*output)(struct net *, struct sock *, struct sk_buff *)) 811 { 812 struct sk_buff *frag; 813 struct rt6_info *rt = (struct rt6_info *)skb_dst(skb); 814 struct ipv6_pinfo *np = skb->sk && !dev_recursion_level() ? 815 inet6_sk(skb->sk) : NULL; 816 struct ip6_frag_state state; 817 unsigned int mtu, hlen, nexthdr_offset; 818 ktime_t tstamp = skb->tstamp; 819 int hroom, err = 0; 820 __be32 frag_id; 821 u8 *prevhdr, nexthdr = 0; 822 823 err = ip6_find_1stfragopt(skb, &prevhdr); 824 if (err < 0) 825 goto fail; 826 hlen = err; 827 nexthdr = *prevhdr; 828 nexthdr_offset = prevhdr - skb_network_header(skb); 829 830 mtu = ip6_skb_dst_mtu(skb); 831 832 /* We must not fragment if the socket is set to force MTU discovery 833 * or if the skb it not generated by a local socket. 834 */ 835 if (unlikely(!skb->ignore_df && skb->len > mtu)) 836 goto fail_toobig; 837 838 if (IP6CB(skb)->frag_max_size) { 839 if (IP6CB(skb)->frag_max_size > mtu) 840 goto fail_toobig; 841 842 /* don't send fragments larger than what we received */ 843 mtu = IP6CB(skb)->frag_max_size; 844 if (mtu < IPV6_MIN_MTU) 845 mtu = IPV6_MIN_MTU; 846 } 847 848 if (np && np->frag_size < mtu) { 849 if (np->frag_size) 850 mtu = np->frag_size; 851 } 852 if (mtu < hlen + sizeof(struct frag_hdr) + 8) 853 goto fail_toobig; 854 mtu -= hlen + sizeof(struct frag_hdr); 855 856 frag_id = ipv6_select_ident(net, &ipv6_hdr(skb)->daddr, 857 &ipv6_hdr(skb)->saddr); 858 859 if (skb->ip_summed == CHECKSUM_PARTIAL && 860 (err = skb_checksum_help(skb))) 861 goto fail; 862 863 prevhdr = skb_network_header(skb) + nexthdr_offset; 864 hroom = LL_RESERVED_SPACE(rt->dst.dev); 865 if (skb_has_frag_list(skb)) { 866 unsigned int first_len = skb_pagelen(skb); 867 struct ip6_fraglist_iter iter; 868 struct sk_buff *frag2; 869 870 if (first_len - hlen > mtu || 871 ((first_len - hlen) & 7) || 872 skb_cloned(skb) || 873 skb_headroom(skb) < (hroom + sizeof(struct frag_hdr))) 874 goto slow_path; 875 876 skb_walk_frags(skb, frag) { 877 /* Correct geometry. */ 878 if (frag->len > mtu || 879 ((frag->len & 7) && frag->next) || 880 skb_headroom(frag) < (hlen + hroom + sizeof(struct frag_hdr))) 881 goto slow_path_clean; 882 883 /* Partially cloned skb? */ 884 if (skb_shared(frag)) 885 goto slow_path_clean; 886 887 BUG_ON(frag->sk); 888 if (skb->sk) { 889 frag->sk = skb->sk; 890 frag->destructor = sock_wfree; 891 } 892 skb->truesize -= frag->truesize; 893 } 894 895 err = ip6_fraglist_init(skb, hlen, prevhdr, nexthdr, frag_id, 896 &iter); 897 if (err < 0) 898 goto fail; 899 900 for (;;) { 901 /* Prepare header of the next frame, 902 * before previous one went down. */ 903 if (iter.frag) 904 ip6_fraglist_prepare(skb, &iter); 905 906 skb->tstamp = tstamp; 907 err = output(net, sk, skb); 908 if (!err) 909 IP6_INC_STATS(net, ip6_dst_idev(&rt->dst), 910 IPSTATS_MIB_FRAGCREATES); 911 912 if (err || !iter.frag) 913 break; 914 915 skb = ip6_fraglist_next(&iter); 916 } 917 918 kfree(iter.tmp_hdr); 919 920 if (err == 0) { 921 IP6_INC_STATS(net, ip6_dst_idev(&rt->dst), 922 IPSTATS_MIB_FRAGOKS); 923 return 0; 924 } 925 926 kfree_skb_list(iter.frag); 927 928 IP6_INC_STATS(net, ip6_dst_idev(&rt->dst), 929 IPSTATS_MIB_FRAGFAILS); 930 return err; 931 932 slow_path_clean: 933 skb_walk_frags(skb, frag2) { 934 if (frag2 == frag) 935 break; 936 frag2->sk = NULL; 937 frag2->destructor = NULL; 938 skb->truesize += frag2->truesize; 939 } 940 } 941 942 slow_path: 943 /* 944 * Fragment the datagram. 945 */ 946 947 ip6_frag_init(skb, hlen, mtu, rt->dst.dev->needed_tailroom, 948 LL_RESERVED_SPACE(rt->dst.dev), prevhdr, nexthdr, frag_id, 949 &state); 950 951 /* 952 * Keep copying data until we run out. 953 */ 954 955 while (state.left > 0) { 956 frag = ip6_frag_next(skb, &state); 957 if (IS_ERR(frag)) { 958 err = PTR_ERR(frag); 959 goto fail; 960 } 961 962 /* 963 * Put this fragment into the sending queue. 964 */ 965 frag->tstamp = tstamp; 966 err = output(net, sk, frag); 967 if (err) 968 goto fail; 969 970 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), 971 IPSTATS_MIB_FRAGCREATES); 972 } 973 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), 974 IPSTATS_MIB_FRAGOKS); 975 consume_skb(skb); 976 return err; 977 978 fail_toobig: 979 if (skb->sk && dst_allfrag(skb_dst(skb))) 980 sk_gso_disable(skb->sk); 981 982 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu); 983 err = -EMSGSIZE; 984 985 fail: 986 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), 987 IPSTATS_MIB_FRAGFAILS); 988 kfree_skb(skb); 989 return err; 990 } 991 992 static inline int ip6_rt_check(const struct rt6key *rt_key, 993 const struct in6_addr *fl_addr, 994 const struct in6_addr *addr_cache) 995 { 996 return (rt_key->plen != 128 || !ipv6_addr_equal(fl_addr, &rt_key->addr)) && 997 (!addr_cache || !ipv6_addr_equal(fl_addr, addr_cache)); 998 } 999 1000 static struct dst_entry *ip6_sk_dst_check(struct sock *sk, 1001 struct dst_entry *dst, 1002 const struct flowi6 *fl6) 1003 { 1004 struct ipv6_pinfo *np = inet6_sk(sk); 1005 struct rt6_info *rt; 1006 1007 if (!dst) 1008 goto out; 1009 1010 if (dst->ops->family != AF_INET6) { 1011 dst_release(dst); 1012 return NULL; 1013 } 1014 1015 rt = (struct rt6_info *)dst; 1016 /* Yes, checking route validity in not connected 1017 * case is not very simple. Take into account, 1018 * that we do not support routing by source, TOS, 1019 * and MSG_DONTROUTE --ANK (980726) 1020 * 1021 * 1. ip6_rt_check(): If route was host route, 1022 * check that cached destination is current. 1023 * If it is network route, we still may 1024 * check its validity using saved pointer 1025 * to the last used address: daddr_cache. 1026 * We do not want to save whole address now, 1027 * (because main consumer of this service 1028 * is tcp, which has not this problem), 1029 * so that the last trick works only on connected 1030 * sockets. 1031 * 2. oif also should be the same. 1032 */ 1033 if (ip6_rt_check(&rt->rt6i_dst, &fl6->daddr, np->daddr_cache) || 1034 #ifdef CONFIG_IPV6_SUBTREES 1035 ip6_rt_check(&rt->rt6i_src, &fl6->saddr, np->saddr_cache) || 1036 #endif 1037 (!(fl6->flowi6_flags & FLOWI_FLAG_SKIP_NH_OIF) && 1038 (fl6->flowi6_oif && fl6->flowi6_oif != dst->dev->ifindex))) { 1039 dst_release(dst); 1040 dst = NULL; 1041 } 1042 1043 out: 1044 return dst; 1045 } 1046 1047 static int ip6_dst_lookup_tail(struct net *net, const struct sock *sk, 1048 struct dst_entry **dst, struct flowi6 *fl6) 1049 { 1050 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD 1051 struct neighbour *n; 1052 struct rt6_info *rt; 1053 #endif 1054 int err; 1055 int flags = 0; 1056 1057 /* The correct way to handle this would be to do 1058 * ip6_route_get_saddr, and then ip6_route_output; however, 1059 * the route-specific preferred source forces the 1060 * ip6_route_output call _before_ ip6_route_get_saddr. 1061 * 1062 * In source specific routing (no src=any default route), 1063 * ip6_route_output will fail given src=any saddr, though, so 1064 * that's why we try it again later. 1065 */ 1066 if (ipv6_addr_any(&fl6->saddr)) { 1067 struct fib6_info *from; 1068 struct rt6_info *rt; 1069 1070 *dst = ip6_route_output(net, sk, fl6); 1071 rt = (*dst)->error ? NULL : (struct rt6_info *)*dst; 1072 1073 rcu_read_lock(); 1074 from = rt ? rcu_dereference(rt->from) : NULL; 1075 err = ip6_route_get_saddr(net, from, &fl6->daddr, 1076 sk ? inet6_sk(sk)->srcprefs : 0, 1077 &fl6->saddr); 1078 rcu_read_unlock(); 1079 1080 if (err) 1081 goto out_err_release; 1082 1083 /* If we had an erroneous initial result, pretend it 1084 * never existed and let the SA-enabled version take 1085 * over. 1086 */ 1087 if ((*dst)->error) { 1088 dst_release(*dst); 1089 *dst = NULL; 1090 } 1091 1092 if (fl6->flowi6_oif) 1093 flags |= RT6_LOOKUP_F_IFACE; 1094 } 1095 1096 if (!*dst) 1097 *dst = ip6_route_output_flags(net, sk, fl6, flags); 1098 1099 err = (*dst)->error; 1100 if (err) 1101 goto out_err_release; 1102 1103 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD 1104 /* 1105 * Here if the dst entry we've looked up 1106 * has a neighbour entry that is in the INCOMPLETE 1107 * state and the src address from the flow is 1108 * marked as OPTIMISTIC, we release the found 1109 * dst entry and replace it instead with the 1110 * dst entry of the nexthop router 1111 */ 1112 rt = (struct rt6_info *) *dst; 1113 rcu_read_lock_bh(); 1114 n = __ipv6_neigh_lookup_noref(rt->dst.dev, 1115 rt6_nexthop(rt, &fl6->daddr)); 1116 err = n && !(n->nud_state & NUD_VALID) ? -EINVAL : 0; 1117 rcu_read_unlock_bh(); 1118 1119 if (err) { 1120 struct inet6_ifaddr *ifp; 1121 struct flowi6 fl_gw6; 1122 int redirect; 1123 1124 ifp = ipv6_get_ifaddr(net, &fl6->saddr, 1125 (*dst)->dev, 1); 1126 1127 redirect = (ifp && ifp->flags & IFA_F_OPTIMISTIC); 1128 if (ifp) 1129 in6_ifa_put(ifp); 1130 1131 if (redirect) { 1132 /* 1133 * We need to get the dst entry for the 1134 * default router instead 1135 */ 1136 dst_release(*dst); 1137 memcpy(&fl_gw6, fl6, sizeof(struct flowi6)); 1138 memset(&fl_gw6.daddr, 0, sizeof(struct in6_addr)); 1139 *dst = ip6_route_output(net, sk, &fl_gw6); 1140 err = (*dst)->error; 1141 if (err) 1142 goto out_err_release; 1143 } 1144 } 1145 #endif 1146 if (ipv6_addr_v4mapped(&fl6->saddr) && 1147 !(ipv6_addr_v4mapped(&fl6->daddr) || ipv6_addr_any(&fl6->daddr))) { 1148 err = -EAFNOSUPPORT; 1149 goto out_err_release; 1150 } 1151 1152 return 0; 1153 1154 out_err_release: 1155 dst_release(*dst); 1156 *dst = NULL; 1157 1158 if (err == -ENETUNREACH) 1159 IP6_INC_STATS(net, NULL, IPSTATS_MIB_OUTNOROUTES); 1160 return err; 1161 } 1162 1163 /** 1164 * ip6_dst_lookup - perform route lookup on flow 1165 * @net: Network namespace to perform lookup in 1166 * @sk: socket which provides route info 1167 * @dst: pointer to dst_entry * for result 1168 * @fl6: flow to lookup 1169 * 1170 * This function performs a route lookup on the given flow. 1171 * 1172 * It returns zero on success, or a standard errno code on error. 1173 */ 1174 int ip6_dst_lookup(struct net *net, struct sock *sk, struct dst_entry **dst, 1175 struct flowi6 *fl6) 1176 { 1177 *dst = NULL; 1178 return ip6_dst_lookup_tail(net, sk, dst, fl6); 1179 } 1180 EXPORT_SYMBOL_GPL(ip6_dst_lookup); 1181 1182 /** 1183 * ip6_dst_lookup_flow - perform route lookup on flow with ipsec 1184 * @net: Network namespace to perform lookup in 1185 * @sk: socket which provides route info 1186 * @fl6: flow to lookup 1187 * @final_dst: final destination address for ipsec lookup 1188 * 1189 * This function performs a route lookup on the given flow. 1190 * 1191 * It returns a valid dst pointer on success, or a pointer encoded 1192 * error code. 1193 */ 1194 struct dst_entry *ip6_dst_lookup_flow(struct net *net, const struct sock *sk, struct flowi6 *fl6, 1195 const struct in6_addr *final_dst) 1196 { 1197 struct dst_entry *dst = NULL; 1198 int err; 1199 1200 err = ip6_dst_lookup_tail(net, sk, &dst, fl6); 1201 if (err) 1202 return ERR_PTR(err); 1203 if (final_dst) 1204 fl6->daddr = *final_dst; 1205 1206 return xfrm_lookup_route(net, dst, flowi6_to_flowi(fl6), sk, 0); 1207 } 1208 EXPORT_SYMBOL_GPL(ip6_dst_lookup_flow); 1209 1210 /** 1211 * ip6_sk_dst_lookup_flow - perform socket cached route lookup on flow 1212 * @sk: socket which provides the dst cache and route info 1213 * @fl6: flow to lookup 1214 * @final_dst: final destination address for ipsec lookup 1215 * @connected: whether @sk is connected or not 1216 * 1217 * This function performs a route lookup on the given flow with the 1218 * possibility of using the cached route in the socket if it is valid. 1219 * It will take the socket dst lock when operating on the dst cache. 1220 * As a result, this function can only be used in process context. 1221 * 1222 * In addition, for a connected socket, cache the dst in the socket 1223 * if the current cache is not valid. 1224 * 1225 * It returns a valid dst pointer on success, or a pointer encoded 1226 * error code. 1227 */ 1228 struct dst_entry *ip6_sk_dst_lookup_flow(struct sock *sk, struct flowi6 *fl6, 1229 const struct in6_addr *final_dst, 1230 bool connected) 1231 { 1232 struct dst_entry *dst = sk_dst_check(sk, inet6_sk(sk)->dst_cookie); 1233 1234 dst = ip6_sk_dst_check(sk, dst, fl6); 1235 if (dst) 1236 return dst; 1237 1238 dst = ip6_dst_lookup_flow(sock_net(sk), sk, fl6, final_dst); 1239 if (connected && !IS_ERR(dst)) 1240 ip6_sk_dst_store_flow(sk, dst_clone(dst), fl6); 1241 1242 return dst; 1243 } 1244 EXPORT_SYMBOL_GPL(ip6_sk_dst_lookup_flow); 1245 1246 /** 1247 * ip6_dst_lookup_tunnel - perform route lookup on tunnel 1248 * @skb: Packet for which lookup is done 1249 * @dev: Tunnel device 1250 * @net: Network namespace of tunnel device 1251 * @sock: Socket which provides route info 1252 * @saddr: Memory to store the src ip address 1253 * @info: Tunnel information 1254 * @protocol: IP protocol 1255 * @use_cache: Flag to enable cache usage 1256 * This function performs a route lookup on a tunnel 1257 * 1258 * It returns a valid dst pointer and stores src address to be used in 1259 * tunnel in param saddr on success, else a pointer encoded error code. 1260 */ 1261 1262 struct dst_entry *ip6_dst_lookup_tunnel(struct sk_buff *skb, 1263 struct net_device *dev, 1264 struct net *net, 1265 struct socket *sock, 1266 struct in6_addr *saddr, 1267 const struct ip_tunnel_info *info, 1268 u8 protocol, 1269 bool use_cache) 1270 { 1271 struct dst_entry *dst = NULL; 1272 #ifdef CONFIG_DST_CACHE 1273 struct dst_cache *dst_cache; 1274 #endif 1275 struct flowi6 fl6; 1276 __u8 prio; 1277 1278 #ifdef CONFIG_DST_CACHE 1279 dst_cache = (struct dst_cache *)&info->dst_cache; 1280 if (use_cache) { 1281 dst = dst_cache_get_ip6(dst_cache, saddr); 1282 if (dst) 1283 return dst; 1284 } 1285 #endif 1286 memset(&fl6, 0, sizeof(fl6)); 1287 fl6.flowi6_mark = skb->mark; 1288 fl6.flowi6_proto = protocol; 1289 fl6.daddr = info->key.u.ipv6.dst; 1290 fl6.saddr = info->key.u.ipv6.src; 1291 prio = info->key.tos; 1292 fl6.flowlabel = ip6_make_flowinfo(RT_TOS(prio), 1293 info->key.label); 1294 1295 dst = ipv6_stub->ipv6_dst_lookup_flow(net, sock->sk, &fl6, 1296 NULL); 1297 if (IS_ERR(dst)) { 1298 netdev_dbg(dev, "no route to %pI6\n", &fl6.daddr); 1299 return ERR_PTR(-ENETUNREACH); 1300 } 1301 if (dst->dev == dev) { /* is this necessary? */ 1302 netdev_dbg(dev, "circular route to %pI6\n", &fl6.daddr); 1303 dst_release(dst); 1304 return ERR_PTR(-ELOOP); 1305 } 1306 #ifdef CONFIG_DST_CACHE 1307 if (use_cache) 1308 dst_cache_set_ip6(dst_cache, dst, &fl6.saddr); 1309 #endif 1310 *saddr = fl6.saddr; 1311 return dst; 1312 } 1313 EXPORT_SYMBOL_GPL(ip6_dst_lookup_tunnel); 1314 1315 static inline struct ipv6_opt_hdr *ip6_opt_dup(struct ipv6_opt_hdr *src, 1316 gfp_t gfp) 1317 { 1318 return src ? kmemdup(src, (src->hdrlen + 1) * 8, gfp) : NULL; 1319 } 1320 1321 static inline struct ipv6_rt_hdr *ip6_rthdr_dup(struct ipv6_rt_hdr *src, 1322 gfp_t gfp) 1323 { 1324 return src ? kmemdup(src, (src->hdrlen + 1) * 8, gfp) : NULL; 1325 } 1326 1327 static void ip6_append_data_mtu(unsigned int *mtu, 1328 int *maxfraglen, 1329 unsigned int fragheaderlen, 1330 struct sk_buff *skb, 1331 struct rt6_info *rt, 1332 unsigned int orig_mtu) 1333 { 1334 if (!(rt->dst.flags & DST_XFRM_TUNNEL)) { 1335 if (!skb) { 1336 /* first fragment, reserve header_len */ 1337 *mtu = orig_mtu - rt->dst.header_len; 1338 1339 } else { 1340 /* 1341 * this fragment is not first, the headers 1342 * space is regarded as data space. 1343 */ 1344 *mtu = orig_mtu; 1345 } 1346 *maxfraglen = ((*mtu - fragheaderlen) & ~7) 1347 + fragheaderlen - sizeof(struct frag_hdr); 1348 } 1349 } 1350 1351 static int ip6_setup_cork(struct sock *sk, struct inet_cork_full *cork, 1352 struct inet6_cork *v6_cork, struct ipcm6_cookie *ipc6, 1353 struct rt6_info *rt) 1354 { 1355 struct ipv6_pinfo *np = inet6_sk(sk); 1356 unsigned int mtu; 1357 struct ipv6_txoptions *nopt, *opt = ipc6->opt; 1358 1359 /* callers pass dst together with a reference, set it first so 1360 * ip6_cork_release() can put it down even in case of an error. 1361 */ 1362 cork->base.dst = &rt->dst; 1363 1364 /* 1365 * setup for corking 1366 */ 1367 if (opt) { 1368 if (WARN_ON(v6_cork->opt)) 1369 return -EINVAL; 1370 1371 nopt = v6_cork->opt = kzalloc(sizeof(*opt), sk->sk_allocation); 1372 if (unlikely(!nopt)) 1373 return -ENOBUFS; 1374 1375 nopt->tot_len = sizeof(*opt); 1376 nopt->opt_flen = opt->opt_flen; 1377 nopt->opt_nflen = opt->opt_nflen; 1378 1379 nopt->dst0opt = ip6_opt_dup(opt->dst0opt, sk->sk_allocation); 1380 if (opt->dst0opt && !nopt->dst0opt) 1381 return -ENOBUFS; 1382 1383 nopt->dst1opt = ip6_opt_dup(opt->dst1opt, sk->sk_allocation); 1384 if (opt->dst1opt && !nopt->dst1opt) 1385 return -ENOBUFS; 1386 1387 nopt->hopopt = ip6_opt_dup(opt->hopopt, sk->sk_allocation); 1388 if (opt->hopopt && !nopt->hopopt) 1389 return -ENOBUFS; 1390 1391 nopt->srcrt = ip6_rthdr_dup(opt->srcrt, sk->sk_allocation); 1392 if (opt->srcrt && !nopt->srcrt) 1393 return -ENOBUFS; 1394 1395 /* need source address above miyazawa*/ 1396 } 1397 v6_cork->hop_limit = ipc6->hlimit; 1398 v6_cork->tclass = ipc6->tclass; 1399 if (rt->dst.flags & DST_XFRM_TUNNEL) 1400 mtu = np->pmtudisc >= IPV6_PMTUDISC_PROBE ? 1401 READ_ONCE(rt->dst.dev->mtu) : dst_mtu(&rt->dst); 1402 else 1403 mtu = np->pmtudisc >= IPV6_PMTUDISC_PROBE ? 1404 READ_ONCE(rt->dst.dev->mtu) : dst_mtu(xfrm_dst_path(&rt->dst)); 1405 if (np->frag_size < mtu) { 1406 if (np->frag_size) 1407 mtu = np->frag_size; 1408 } 1409 if (mtu < IPV6_MIN_MTU) 1410 return -EINVAL; 1411 cork->base.fragsize = mtu; 1412 cork->base.gso_size = ipc6->gso_size; 1413 cork->base.tx_flags = 0; 1414 cork->base.mark = ipc6->sockc.mark; 1415 sock_tx_timestamp(sk, ipc6->sockc.tsflags, &cork->base.tx_flags); 1416 1417 if (dst_allfrag(xfrm_dst_path(&rt->dst))) 1418 cork->base.flags |= IPCORK_ALLFRAG; 1419 cork->base.length = 0; 1420 1421 cork->base.transmit_time = ipc6->sockc.transmit_time; 1422 1423 return 0; 1424 } 1425 1426 static int __ip6_append_data(struct sock *sk, 1427 struct sk_buff_head *queue, 1428 struct inet_cork_full *cork_full, 1429 struct inet6_cork *v6_cork, 1430 struct page_frag *pfrag, 1431 int getfrag(void *from, char *to, int offset, 1432 int len, int odd, struct sk_buff *skb), 1433 void *from, int length, int transhdrlen, 1434 unsigned int flags, struct ipcm6_cookie *ipc6) 1435 { 1436 struct sk_buff *skb, *skb_prev = NULL; 1437 struct inet_cork *cork = &cork_full->base; 1438 struct flowi6 *fl6 = &cork_full->fl.u.ip6; 1439 unsigned int maxfraglen, fragheaderlen, mtu, orig_mtu, pmtu; 1440 struct ubuf_info *uarg = NULL; 1441 int exthdrlen = 0; 1442 int dst_exthdrlen = 0; 1443 int hh_len; 1444 int copy; 1445 int err; 1446 int offset = 0; 1447 u32 tskey = 0; 1448 struct rt6_info *rt = (struct rt6_info *)cork->dst; 1449 struct ipv6_txoptions *opt = v6_cork->opt; 1450 int csummode = CHECKSUM_NONE; 1451 unsigned int maxnonfragsize, headersize; 1452 unsigned int wmem_alloc_delta = 0; 1453 bool paged, extra_uref = false; 1454 1455 skb = skb_peek_tail(queue); 1456 if (!skb) { 1457 exthdrlen = opt ? opt->opt_flen : 0; 1458 dst_exthdrlen = rt->dst.header_len - rt->rt6i_nfheader_len; 1459 } 1460 1461 paged = !!cork->gso_size; 1462 mtu = cork->gso_size ? IP6_MAX_MTU : cork->fragsize; 1463 orig_mtu = mtu; 1464 1465 if (cork->tx_flags & SKBTX_ANY_SW_TSTAMP && 1466 sk->sk_tsflags & SOF_TIMESTAMPING_OPT_ID) 1467 tskey = sk->sk_tskey++; 1468 1469 hh_len = LL_RESERVED_SPACE(rt->dst.dev); 1470 1471 fragheaderlen = sizeof(struct ipv6hdr) + rt->rt6i_nfheader_len + 1472 (opt ? opt->opt_nflen : 0); 1473 maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen - 1474 sizeof(struct frag_hdr); 1475 1476 headersize = sizeof(struct ipv6hdr) + 1477 (opt ? opt->opt_flen + opt->opt_nflen : 0) + 1478 (dst_allfrag(&rt->dst) ? 1479 sizeof(struct frag_hdr) : 0) + 1480 rt->rt6i_nfheader_len; 1481 1482 /* as per RFC 7112 section 5, the entire IPv6 Header Chain must fit 1483 * the first fragment 1484 */ 1485 if (headersize + transhdrlen > mtu) 1486 goto emsgsize; 1487 1488 if (cork->length + length > mtu - headersize && ipc6->dontfrag && 1489 (sk->sk_protocol == IPPROTO_UDP || 1490 sk->sk_protocol == IPPROTO_RAW)) { 1491 ipv6_local_rxpmtu(sk, fl6, mtu - headersize + 1492 sizeof(struct ipv6hdr)); 1493 goto emsgsize; 1494 } 1495 1496 if (ip6_sk_ignore_df(sk)) 1497 maxnonfragsize = sizeof(struct ipv6hdr) + IPV6_MAXPLEN; 1498 else 1499 maxnonfragsize = mtu; 1500 1501 if (cork->length + length > maxnonfragsize - headersize) { 1502 emsgsize: 1503 pmtu = max_t(int, mtu - headersize + sizeof(struct ipv6hdr), 0); 1504 ipv6_local_error(sk, EMSGSIZE, fl6, pmtu); 1505 return -EMSGSIZE; 1506 } 1507 1508 /* CHECKSUM_PARTIAL only with no extension headers and when 1509 * we are not going to fragment 1510 */ 1511 if (transhdrlen && sk->sk_protocol == IPPROTO_UDP && 1512 headersize == sizeof(struct ipv6hdr) && 1513 length <= mtu - headersize && 1514 (!(flags & MSG_MORE) || cork->gso_size) && 1515 rt->dst.dev->features & (NETIF_F_IPV6_CSUM | NETIF_F_HW_CSUM)) 1516 csummode = CHECKSUM_PARTIAL; 1517 1518 if (flags & MSG_ZEROCOPY && length && sock_flag(sk, SOCK_ZEROCOPY)) { 1519 uarg = msg_zerocopy_realloc(sk, length, skb_zcopy(skb)); 1520 if (!uarg) 1521 return -ENOBUFS; 1522 extra_uref = !skb_zcopy(skb); /* only ref on new uarg */ 1523 if (rt->dst.dev->features & NETIF_F_SG && 1524 csummode == CHECKSUM_PARTIAL) { 1525 paged = true; 1526 } else { 1527 uarg->zerocopy = 0; 1528 skb_zcopy_set(skb, uarg, &extra_uref); 1529 } 1530 } 1531 1532 /* 1533 * Let's try using as much space as possible. 1534 * Use MTU if total length of the message fits into the MTU. 1535 * Otherwise, we need to reserve fragment header and 1536 * fragment alignment (= 8-15 octects, in total). 1537 * 1538 * Note that we may need to "move" the data from the tail 1539 * of the buffer to the new fragment when we split 1540 * the message. 1541 * 1542 * FIXME: It may be fragmented into multiple chunks 1543 * at once if non-fragmentable extension headers 1544 * are too large. 1545 * --yoshfuji 1546 */ 1547 1548 cork->length += length; 1549 if (!skb) 1550 goto alloc_new_skb; 1551 1552 while (length > 0) { 1553 /* Check if the remaining data fits into current packet. */ 1554 copy = (cork->length <= mtu && !(cork->flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - skb->len; 1555 if (copy < length) 1556 copy = maxfraglen - skb->len; 1557 1558 if (copy <= 0) { 1559 char *data; 1560 unsigned int datalen; 1561 unsigned int fraglen; 1562 unsigned int fraggap; 1563 unsigned int alloclen, alloc_extra; 1564 unsigned int pagedlen; 1565 alloc_new_skb: 1566 /* There's no room in the current skb */ 1567 if (skb) 1568 fraggap = skb->len - maxfraglen; 1569 else 1570 fraggap = 0; 1571 /* update mtu and maxfraglen if necessary */ 1572 if (!skb || !skb_prev) 1573 ip6_append_data_mtu(&mtu, &maxfraglen, 1574 fragheaderlen, skb, rt, 1575 orig_mtu); 1576 1577 skb_prev = skb; 1578 1579 /* 1580 * If remaining data exceeds the mtu, 1581 * we know we need more fragment(s). 1582 */ 1583 datalen = length + fraggap; 1584 1585 if (datalen > (cork->length <= mtu && !(cork->flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - fragheaderlen) 1586 datalen = maxfraglen - fragheaderlen - rt->dst.trailer_len; 1587 fraglen = datalen + fragheaderlen; 1588 pagedlen = 0; 1589 1590 alloc_extra = hh_len; 1591 alloc_extra += dst_exthdrlen; 1592 alloc_extra += rt->dst.trailer_len; 1593 1594 /* We just reserve space for fragment header. 1595 * Note: this may be overallocation if the message 1596 * (without MSG_MORE) fits into the MTU. 1597 */ 1598 alloc_extra += sizeof(struct frag_hdr); 1599 1600 if ((flags & MSG_MORE) && 1601 !(rt->dst.dev->features&NETIF_F_SG)) 1602 alloclen = mtu; 1603 else if (!paged && 1604 (fraglen + alloc_extra < SKB_MAX_ALLOC || 1605 !(rt->dst.dev->features & NETIF_F_SG))) 1606 alloclen = fraglen; 1607 else { 1608 alloclen = min_t(int, fraglen, MAX_HEADER); 1609 pagedlen = fraglen - alloclen; 1610 } 1611 alloclen += alloc_extra; 1612 1613 if (datalen != length + fraggap) { 1614 /* 1615 * this is not the last fragment, the trailer 1616 * space is regarded as data space. 1617 */ 1618 datalen += rt->dst.trailer_len; 1619 } 1620 1621 fraglen = datalen + fragheaderlen; 1622 1623 copy = datalen - transhdrlen - fraggap - pagedlen; 1624 if (copy < 0) { 1625 err = -EINVAL; 1626 goto error; 1627 } 1628 if (transhdrlen) { 1629 skb = sock_alloc_send_skb(sk, alloclen, 1630 (flags & MSG_DONTWAIT), &err); 1631 } else { 1632 skb = NULL; 1633 if (refcount_read(&sk->sk_wmem_alloc) + wmem_alloc_delta <= 1634 2 * sk->sk_sndbuf) 1635 skb = alloc_skb(alloclen, 1636 sk->sk_allocation); 1637 if (unlikely(!skb)) 1638 err = -ENOBUFS; 1639 } 1640 if (!skb) 1641 goto error; 1642 /* 1643 * Fill in the control structures 1644 */ 1645 skb->protocol = htons(ETH_P_IPV6); 1646 skb->ip_summed = csummode; 1647 skb->csum = 0; 1648 /* reserve for fragmentation and ipsec header */ 1649 skb_reserve(skb, hh_len + sizeof(struct frag_hdr) + 1650 dst_exthdrlen); 1651 1652 /* 1653 * Find where to start putting bytes 1654 */ 1655 data = skb_put(skb, fraglen - pagedlen); 1656 skb_set_network_header(skb, exthdrlen); 1657 data += fragheaderlen; 1658 skb->transport_header = (skb->network_header + 1659 fragheaderlen); 1660 if (fraggap) { 1661 skb->csum = skb_copy_and_csum_bits( 1662 skb_prev, maxfraglen, 1663 data + transhdrlen, fraggap); 1664 skb_prev->csum = csum_sub(skb_prev->csum, 1665 skb->csum); 1666 data += fraggap; 1667 pskb_trim_unique(skb_prev, maxfraglen); 1668 } 1669 if (copy > 0 && 1670 getfrag(from, data + transhdrlen, offset, 1671 copy, fraggap, skb) < 0) { 1672 err = -EFAULT; 1673 kfree_skb(skb); 1674 goto error; 1675 } 1676 1677 offset += copy; 1678 length -= copy + transhdrlen; 1679 transhdrlen = 0; 1680 exthdrlen = 0; 1681 dst_exthdrlen = 0; 1682 1683 /* Only the initial fragment is time stamped */ 1684 skb_shinfo(skb)->tx_flags = cork->tx_flags; 1685 cork->tx_flags = 0; 1686 skb_shinfo(skb)->tskey = tskey; 1687 tskey = 0; 1688 skb_zcopy_set(skb, uarg, &extra_uref); 1689 1690 if ((flags & MSG_CONFIRM) && !skb_prev) 1691 skb_set_dst_pending_confirm(skb, 1); 1692 1693 /* 1694 * Put the packet on the pending queue 1695 */ 1696 if (!skb->destructor) { 1697 skb->destructor = sock_wfree; 1698 skb->sk = sk; 1699 wmem_alloc_delta += skb->truesize; 1700 } 1701 __skb_queue_tail(queue, skb); 1702 continue; 1703 } 1704 1705 if (copy > length) 1706 copy = length; 1707 1708 if (!(rt->dst.dev->features&NETIF_F_SG) && 1709 skb_tailroom(skb) >= copy) { 1710 unsigned int off; 1711 1712 off = skb->len; 1713 if (getfrag(from, skb_put(skb, copy), 1714 offset, copy, off, skb) < 0) { 1715 __skb_trim(skb, off); 1716 err = -EFAULT; 1717 goto error; 1718 } 1719 } else if (!uarg || !uarg->zerocopy) { 1720 int i = skb_shinfo(skb)->nr_frags; 1721 1722 err = -ENOMEM; 1723 if (!sk_page_frag_refill(sk, pfrag)) 1724 goto error; 1725 1726 if (!skb_can_coalesce(skb, i, pfrag->page, 1727 pfrag->offset)) { 1728 err = -EMSGSIZE; 1729 if (i == MAX_SKB_FRAGS) 1730 goto error; 1731 1732 __skb_fill_page_desc(skb, i, pfrag->page, 1733 pfrag->offset, 0); 1734 skb_shinfo(skb)->nr_frags = ++i; 1735 get_page(pfrag->page); 1736 } 1737 copy = min_t(int, copy, pfrag->size - pfrag->offset); 1738 if (getfrag(from, 1739 page_address(pfrag->page) + pfrag->offset, 1740 offset, copy, skb->len, skb) < 0) 1741 goto error_efault; 1742 1743 pfrag->offset += copy; 1744 skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], copy); 1745 skb->len += copy; 1746 skb->data_len += copy; 1747 skb->truesize += copy; 1748 wmem_alloc_delta += copy; 1749 } else { 1750 err = skb_zerocopy_iter_dgram(skb, from, copy); 1751 if (err < 0) 1752 goto error; 1753 } 1754 offset += copy; 1755 length -= copy; 1756 } 1757 1758 if (wmem_alloc_delta) 1759 refcount_add(wmem_alloc_delta, &sk->sk_wmem_alloc); 1760 return 0; 1761 1762 error_efault: 1763 err = -EFAULT; 1764 error: 1765 net_zcopy_put_abort(uarg, extra_uref); 1766 cork->length -= length; 1767 IP6_INC_STATS(sock_net(sk), rt->rt6i_idev, IPSTATS_MIB_OUTDISCARDS); 1768 refcount_add(wmem_alloc_delta, &sk->sk_wmem_alloc); 1769 return err; 1770 } 1771 1772 int ip6_append_data(struct sock *sk, 1773 int getfrag(void *from, char *to, int offset, int len, 1774 int odd, struct sk_buff *skb), 1775 void *from, int length, int transhdrlen, 1776 struct ipcm6_cookie *ipc6, struct flowi6 *fl6, 1777 struct rt6_info *rt, unsigned int flags) 1778 { 1779 struct inet_sock *inet = inet_sk(sk); 1780 struct ipv6_pinfo *np = inet6_sk(sk); 1781 int exthdrlen; 1782 int err; 1783 1784 if (flags&MSG_PROBE) 1785 return 0; 1786 if (skb_queue_empty(&sk->sk_write_queue)) { 1787 /* 1788 * setup for corking 1789 */ 1790 dst_hold(&rt->dst); 1791 err = ip6_setup_cork(sk, &inet->cork, &np->cork, 1792 ipc6, rt); 1793 if (err) 1794 return err; 1795 1796 inet->cork.fl.u.ip6 = *fl6; 1797 exthdrlen = (ipc6->opt ? ipc6->opt->opt_flen : 0); 1798 length += exthdrlen; 1799 transhdrlen += exthdrlen; 1800 } else { 1801 transhdrlen = 0; 1802 } 1803 1804 return __ip6_append_data(sk, &sk->sk_write_queue, &inet->cork, 1805 &np->cork, sk_page_frag(sk), getfrag, 1806 from, length, transhdrlen, flags, ipc6); 1807 } 1808 EXPORT_SYMBOL_GPL(ip6_append_data); 1809 1810 static void ip6_cork_steal_dst(struct sk_buff *skb, struct inet_cork_full *cork) 1811 { 1812 struct dst_entry *dst = cork->base.dst; 1813 1814 cork->base.dst = NULL; 1815 cork->base.flags &= ~IPCORK_ALLFRAG; 1816 skb_dst_set(skb, dst); 1817 } 1818 1819 static void ip6_cork_release(struct inet_cork_full *cork, 1820 struct inet6_cork *v6_cork) 1821 { 1822 if (v6_cork->opt) { 1823 struct ipv6_txoptions *opt = v6_cork->opt; 1824 1825 kfree(opt->dst0opt); 1826 kfree(opt->dst1opt); 1827 kfree(opt->hopopt); 1828 kfree(opt->srcrt); 1829 kfree(opt); 1830 v6_cork->opt = NULL; 1831 } 1832 1833 if (cork->base.dst) { 1834 dst_release(cork->base.dst); 1835 cork->base.dst = NULL; 1836 cork->base.flags &= ~IPCORK_ALLFRAG; 1837 } 1838 } 1839 1840 struct sk_buff *__ip6_make_skb(struct sock *sk, 1841 struct sk_buff_head *queue, 1842 struct inet_cork_full *cork, 1843 struct inet6_cork *v6_cork) 1844 { 1845 struct sk_buff *skb, *tmp_skb; 1846 struct sk_buff **tail_skb; 1847 struct in6_addr *final_dst; 1848 struct ipv6_pinfo *np = inet6_sk(sk); 1849 struct net *net = sock_net(sk); 1850 struct ipv6hdr *hdr; 1851 struct ipv6_txoptions *opt = v6_cork->opt; 1852 struct rt6_info *rt = (struct rt6_info *)cork->base.dst; 1853 struct flowi6 *fl6 = &cork->fl.u.ip6; 1854 unsigned char proto = fl6->flowi6_proto; 1855 1856 skb = __skb_dequeue(queue); 1857 if (!skb) 1858 goto out; 1859 tail_skb = &(skb_shinfo(skb)->frag_list); 1860 1861 /* move skb->data to ip header from ext header */ 1862 if (skb->data < skb_network_header(skb)) 1863 __skb_pull(skb, skb_network_offset(skb)); 1864 while ((tmp_skb = __skb_dequeue(queue)) != NULL) { 1865 __skb_pull(tmp_skb, skb_network_header_len(skb)); 1866 *tail_skb = tmp_skb; 1867 tail_skb = &(tmp_skb->next); 1868 skb->len += tmp_skb->len; 1869 skb->data_len += tmp_skb->len; 1870 skb->truesize += tmp_skb->truesize; 1871 tmp_skb->destructor = NULL; 1872 tmp_skb->sk = NULL; 1873 } 1874 1875 /* Allow local fragmentation. */ 1876 skb->ignore_df = ip6_sk_ignore_df(sk); 1877 __skb_pull(skb, skb_network_header_len(skb)); 1878 1879 final_dst = &fl6->daddr; 1880 if (opt && opt->opt_flen) 1881 ipv6_push_frag_opts(skb, opt, &proto); 1882 if (opt && opt->opt_nflen) 1883 ipv6_push_nfrag_opts(skb, opt, &proto, &final_dst, &fl6->saddr); 1884 1885 skb_push(skb, sizeof(struct ipv6hdr)); 1886 skb_reset_network_header(skb); 1887 hdr = ipv6_hdr(skb); 1888 1889 ip6_flow_hdr(hdr, v6_cork->tclass, 1890 ip6_make_flowlabel(net, skb, fl6->flowlabel, 1891 ip6_autoflowlabel(net, np), fl6)); 1892 hdr->hop_limit = v6_cork->hop_limit; 1893 hdr->nexthdr = proto; 1894 hdr->saddr = fl6->saddr; 1895 hdr->daddr = *final_dst; 1896 1897 skb->priority = sk->sk_priority; 1898 skb->mark = cork->base.mark; 1899 skb->tstamp = cork->base.transmit_time; 1900 1901 ip6_cork_steal_dst(skb, cork); 1902 IP6_UPD_PO_STATS(net, rt->rt6i_idev, IPSTATS_MIB_OUT, skb->len); 1903 if (proto == IPPROTO_ICMPV6) { 1904 struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb)); 1905 1906 ICMP6MSGOUT_INC_STATS(net, idev, icmp6_hdr(skb)->icmp6_type); 1907 ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTMSGS); 1908 } 1909 1910 ip6_cork_release(cork, v6_cork); 1911 out: 1912 return skb; 1913 } 1914 1915 int ip6_send_skb(struct sk_buff *skb) 1916 { 1917 struct net *net = sock_net(skb->sk); 1918 struct rt6_info *rt = (struct rt6_info *)skb_dst(skb); 1919 int err; 1920 1921 err = ip6_local_out(net, skb->sk, skb); 1922 if (err) { 1923 if (err > 0) 1924 err = net_xmit_errno(err); 1925 if (err) 1926 IP6_INC_STATS(net, rt->rt6i_idev, 1927 IPSTATS_MIB_OUTDISCARDS); 1928 } 1929 1930 return err; 1931 } 1932 1933 int ip6_push_pending_frames(struct sock *sk) 1934 { 1935 struct sk_buff *skb; 1936 1937 skb = ip6_finish_skb(sk); 1938 if (!skb) 1939 return 0; 1940 1941 return ip6_send_skb(skb); 1942 } 1943 EXPORT_SYMBOL_GPL(ip6_push_pending_frames); 1944 1945 static void __ip6_flush_pending_frames(struct sock *sk, 1946 struct sk_buff_head *queue, 1947 struct inet_cork_full *cork, 1948 struct inet6_cork *v6_cork) 1949 { 1950 struct sk_buff *skb; 1951 1952 while ((skb = __skb_dequeue_tail(queue)) != NULL) { 1953 if (skb_dst(skb)) 1954 IP6_INC_STATS(sock_net(sk), ip6_dst_idev(skb_dst(skb)), 1955 IPSTATS_MIB_OUTDISCARDS); 1956 kfree_skb(skb); 1957 } 1958 1959 ip6_cork_release(cork, v6_cork); 1960 } 1961 1962 void ip6_flush_pending_frames(struct sock *sk) 1963 { 1964 __ip6_flush_pending_frames(sk, &sk->sk_write_queue, 1965 &inet_sk(sk)->cork, &inet6_sk(sk)->cork); 1966 } 1967 EXPORT_SYMBOL_GPL(ip6_flush_pending_frames); 1968 1969 struct sk_buff *ip6_make_skb(struct sock *sk, 1970 int getfrag(void *from, char *to, int offset, 1971 int len, int odd, struct sk_buff *skb), 1972 void *from, int length, int transhdrlen, 1973 struct ipcm6_cookie *ipc6, struct rt6_info *rt, 1974 unsigned int flags, struct inet_cork_full *cork) 1975 { 1976 struct inet6_cork v6_cork; 1977 struct sk_buff_head queue; 1978 int exthdrlen = (ipc6->opt ? ipc6->opt->opt_flen : 0); 1979 int err; 1980 1981 if (flags & MSG_PROBE) { 1982 dst_release(&rt->dst); 1983 return NULL; 1984 } 1985 1986 __skb_queue_head_init(&queue); 1987 1988 cork->base.flags = 0; 1989 cork->base.addr = 0; 1990 cork->base.opt = NULL; 1991 v6_cork.opt = NULL; 1992 err = ip6_setup_cork(sk, cork, &v6_cork, ipc6, rt); 1993 if (err) { 1994 ip6_cork_release(cork, &v6_cork); 1995 return ERR_PTR(err); 1996 } 1997 if (ipc6->dontfrag < 0) 1998 ipc6->dontfrag = inet6_sk(sk)->dontfrag; 1999 2000 err = __ip6_append_data(sk, &queue, cork, &v6_cork, 2001 ¤t->task_frag, getfrag, from, 2002 length + exthdrlen, transhdrlen + exthdrlen, 2003 flags, ipc6); 2004 if (err) { 2005 __ip6_flush_pending_frames(sk, &queue, cork, &v6_cork); 2006 return ERR_PTR(err); 2007 } 2008 2009 return __ip6_make_skb(sk, &queue, cork, &v6_cork); 2010 } 2011