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_reason(skb, SKB_DROP_REASON_NEIGH_CREATEFAIL); 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_reason(skb, SKB_DROP_REASON_BPF_CGROUP_EGRESS); 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_reason(skb, SKB_DROP_REASON_IPV6DISABLED); 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_clear_tstamp(skb); 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 bool mono_delivery_time = skb->mono_delivery_time; 817 struct ip6_frag_state state; 818 unsigned int mtu, hlen, nexthdr_offset; 819 ktime_t tstamp = skb->tstamp; 820 int hroom, err = 0; 821 __be32 frag_id; 822 u8 *prevhdr, nexthdr = 0; 823 824 err = ip6_find_1stfragopt(skb, &prevhdr); 825 if (err < 0) 826 goto fail; 827 hlen = err; 828 nexthdr = *prevhdr; 829 nexthdr_offset = prevhdr - skb_network_header(skb); 830 831 mtu = ip6_skb_dst_mtu(skb); 832 833 /* We must not fragment if the socket is set to force MTU discovery 834 * or if the skb it not generated by a local socket. 835 */ 836 if (unlikely(!skb->ignore_df && skb->len > mtu)) 837 goto fail_toobig; 838 839 if (IP6CB(skb)->frag_max_size) { 840 if (IP6CB(skb)->frag_max_size > mtu) 841 goto fail_toobig; 842 843 /* don't send fragments larger than what we received */ 844 mtu = IP6CB(skb)->frag_max_size; 845 if (mtu < IPV6_MIN_MTU) 846 mtu = IPV6_MIN_MTU; 847 } 848 849 if (np && np->frag_size < mtu) { 850 if (np->frag_size) 851 mtu = np->frag_size; 852 } 853 if (mtu < hlen + sizeof(struct frag_hdr) + 8) 854 goto fail_toobig; 855 mtu -= hlen + sizeof(struct frag_hdr); 856 857 frag_id = ipv6_select_ident(net, &ipv6_hdr(skb)->daddr, 858 &ipv6_hdr(skb)->saddr); 859 860 if (skb->ip_summed == CHECKSUM_PARTIAL && 861 (err = skb_checksum_help(skb))) 862 goto fail; 863 864 prevhdr = skb_network_header(skb) + nexthdr_offset; 865 hroom = LL_RESERVED_SPACE(rt->dst.dev); 866 if (skb_has_frag_list(skb)) { 867 unsigned int first_len = skb_pagelen(skb); 868 struct ip6_fraglist_iter iter; 869 struct sk_buff *frag2; 870 871 if (first_len - hlen > mtu || 872 ((first_len - hlen) & 7) || 873 skb_cloned(skb) || 874 skb_headroom(skb) < (hroom + sizeof(struct frag_hdr))) 875 goto slow_path; 876 877 skb_walk_frags(skb, frag) { 878 /* Correct geometry. */ 879 if (frag->len > mtu || 880 ((frag->len & 7) && frag->next) || 881 skb_headroom(frag) < (hlen + hroom + sizeof(struct frag_hdr))) 882 goto slow_path_clean; 883 884 /* Partially cloned skb? */ 885 if (skb_shared(frag)) 886 goto slow_path_clean; 887 888 BUG_ON(frag->sk); 889 if (skb->sk) { 890 frag->sk = skb->sk; 891 frag->destructor = sock_wfree; 892 } 893 skb->truesize -= frag->truesize; 894 } 895 896 err = ip6_fraglist_init(skb, hlen, prevhdr, nexthdr, frag_id, 897 &iter); 898 if (err < 0) 899 goto fail; 900 901 for (;;) { 902 /* Prepare header of the next frame, 903 * before previous one went down. */ 904 if (iter.frag) 905 ip6_fraglist_prepare(skb, &iter); 906 907 skb_set_delivery_time(skb, tstamp, mono_delivery_time); 908 err = output(net, sk, skb); 909 if (!err) 910 IP6_INC_STATS(net, ip6_dst_idev(&rt->dst), 911 IPSTATS_MIB_FRAGCREATES); 912 913 if (err || !iter.frag) 914 break; 915 916 skb = ip6_fraglist_next(&iter); 917 } 918 919 kfree(iter.tmp_hdr); 920 921 if (err == 0) { 922 IP6_INC_STATS(net, ip6_dst_idev(&rt->dst), 923 IPSTATS_MIB_FRAGOKS); 924 return 0; 925 } 926 927 kfree_skb_list(iter.frag); 928 929 IP6_INC_STATS(net, ip6_dst_idev(&rt->dst), 930 IPSTATS_MIB_FRAGFAILS); 931 return err; 932 933 slow_path_clean: 934 skb_walk_frags(skb, frag2) { 935 if (frag2 == frag) 936 break; 937 frag2->sk = NULL; 938 frag2->destructor = NULL; 939 skb->truesize += frag2->truesize; 940 } 941 } 942 943 slow_path: 944 /* 945 * Fragment the datagram. 946 */ 947 948 ip6_frag_init(skb, hlen, mtu, rt->dst.dev->needed_tailroom, 949 LL_RESERVED_SPACE(rt->dst.dev), prevhdr, nexthdr, frag_id, 950 &state); 951 952 /* 953 * Keep copying data until we run out. 954 */ 955 956 while (state.left > 0) { 957 frag = ip6_frag_next(skb, &state); 958 if (IS_ERR(frag)) { 959 err = PTR_ERR(frag); 960 goto fail; 961 } 962 963 /* 964 * Put this fragment into the sending queue. 965 */ 966 skb_set_delivery_time(frag, tstamp, mono_delivery_time); 967 err = output(net, sk, frag); 968 if (err) 969 goto fail; 970 971 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), 972 IPSTATS_MIB_FRAGCREATES); 973 } 974 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), 975 IPSTATS_MIB_FRAGOKS); 976 consume_skb(skb); 977 return err; 978 979 fail_toobig: 980 if (skb->sk && dst_allfrag(skb_dst(skb))) 981 sk_gso_disable(skb->sk); 982 983 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu); 984 err = -EMSGSIZE; 985 986 fail: 987 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), 988 IPSTATS_MIB_FRAGFAILS); 989 kfree_skb(skb); 990 return err; 991 } 992 993 static inline int ip6_rt_check(const struct rt6key *rt_key, 994 const struct in6_addr *fl_addr, 995 const struct in6_addr *addr_cache) 996 { 997 return (rt_key->plen != 128 || !ipv6_addr_equal(fl_addr, &rt_key->addr)) && 998 (!addr_cache || !ipv6_addr_equal(fl_addr, addr_cache)); 999 } 1000 1001 static struct dst_entry *ip6_sk_dst_check(struct sock *sk, 1002 struct dst_entry *dst, 1003 const struct flowi6 *fl6) 1004 { 1005 struct ipv6_pinfo *np = inet6_sk(sk); 1006 struct rt6_info *rt; 1007 1008 if (!dst) 1009 goto out; 1010 1011 if (dst->ops->family != AF_INET6) { 1012 dst_release(dst); 1013 return NULL; 1014 } 1015 1016 rt = (struct rt6_info *)dst; 1017 /* Yes, checking route validity in not connected 1018 * case is not very simple. Take into account, 1019 * that we do not support routing by source, TOS, 1020 * and MSG_DONTROUTE --ANK (980726) 1021 * 1022 * 1. ip6_rt_check(): If route was host route, 1023 * check that cached destination is current. 1024 * If it is network route, we still may 1025 * check its validity using saved pointer 1026 * to the last used address: daddr_cache. 1027 * We do not want to save whole address now, 1028 * (because main consumer of this service 1029 * is tcp, which has not this problem), 1030 * so that the last trick works only on connected 1031 * sockets. 1032 * 2. oif also should be the same. 1033 */ 1034 if (ip6_rt_check(&rt->rt6i_dst, &fl6->daddr, np->daddr_cache) || 1035 #ifdef CONFIG_IPV6_SUBTREES 1036 ip6_rt_check(&rt->rt6i_src, &fl6->saddr, np->saddr_cache) || 1037 #endif 1038 (!(fl6->flowi6_flags & FLOWI_FLAG_SKIP_NH_OIF) && 1039 (fl6->flowi6_oif && fl6->flowi6_oif != dst->dev->ifindex))) { 1040 dst_release(dst); 1041 dst = NULL; 1042 } 1043 1044 out: 1045 return dst; 1046 } 1047 1048 static int ip6_dst_lookup_tail(struct net *net, const struct sock *sk, 1049 struct dst_entry **dst, struct flowi6 *fl6) 1050 { 1051 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD 1052 struct neighbour *n; 1053 struct rt6_info *rt; 1054 #endif 1055 int err; 1056 int flags = 0; 1057 1058 /* The correct way to handle this would be to do 1059 * ip6_route_get_saddr, and then ip6_route_output; however, 1060 * the route-specific preferred source forces the 1061 * ip6_route_output call _before_ ip6_route_get_saddr. 1062 * 1063 * In source specific routing (no src=any default route), 1064 * ip6_route_output will fail given src=any saddr, though, so 1065 * that's why we try it again later. 1066 */ 1067 if (ipv6_addr_any(&fl6->saddr)) { 1068 struct fib6_info *from; 1069 struct rt6_info *rt; 1070 1071 *dst = ip6_route_output(net, sk, fl6); 1072 rt = (*dst)->error ? NULL : (struct rt6_info *)*dst; 1073 1074 rcu_read_lock(); 1075 from = rt ? rcu_dereference(rt->from) : NULL; 1076 err = ip6_route_get_saddr(net, from, &fl6->daddr, 1077 sk ? inet6_sk(sk)->srcprefs : 0, 1078 &fl6->saddr); 1079 rcu_read_unlock(); 1080 1081 if (err) 1082 goto out_err_release; 1083 1084 /* If we had an erroneous initial result, pretend it 1085 * never existed and let the SA-enabled version take 1086 * over. 1087 */ 1088 if ((*dst)->error) { 1089 dst_release(*dst); 1090 *dst = NULL; 1091 } 1092 1093 if (fl6->flowi6_oif) 1094 flags |= RT6_LOOKUP_F_IFACE; 1095 } 1096 1097 if (!*dst) 1098 *dst = ip6_route_output_flags(net, sk, fl6, flags); 1099 1100 err = (*dst)->error; 1101 if (err) 1102 goto out_err_release; 1103 1104 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD 1105 /* 1106 * Here if the dst entry we've looked up 1107 * has a neighbour entry that is in the INCOMPLETE 1108 * state and the src address from the flow is 1109 * marked as OPTIMISTIC, we release the found 1110 * dst entry and replace it instead with the 1111 * dst entry of the nexthop router 1112 */ 1113 rt = (struct rt6_info *) *dst; 1114 rcu_read_lock_bh(); 1115 n = __ipv6_neigh_lookup_noref(rt->dst.dev, 1116 rt6_nexthop(rt, &fl6->daddr)); 1117 err = n && !(n->nud_state & NUD_VALID) ? -EINVAL : 0; 1118 rcu_read_unlock_bh(); 1119 1120 if (err) { 1121 struct inet6_ifaddr *ifp; 1122 struct flowi6 fl_gw6; 1123 int redirect; 1124 1125 ifp = ipv6_get_ifaddr(net, &fl6->saddr, 1126 (*dst)->dev, 1); 1127 1128 redirect = (ifp && ifp->flags & IFA_F_OPTIMISTIC); 1129 if (ifp) 1130 in6_ifa_put(ifp); 1131 1132 if (redirect) { 1133 /* 1134 * We need to get the dst entry for the 1135 * default router instead 1136 */ 1137 dst_release(*dst); 1138 memcpy(&fl_gw6, fl6, sizeof(struct flowi6)); 1139 memset(&fl_gw6.daddr, 0, sizeof(struct in6_addr)); 1140 *dst = ip6_route_output(net, sk, &fl_gw6); 1141 err = (*dst)->error; 1142 if (err) 1143 goto out_err_release; 1144 } 1145 } 1146 #endif 1147 if (ipv6_addr_v4mapped(&fl6->saddr) && 1148 !(ipv6_addr_v4mapped(&fl6->daddr) || ipv6_addr_any(&fl6->daddr))) { 1149 err = -EAFNOSUPPORT; 1150 goto out_err_release; 1151 } 1152 1153 return 0; 1154 1155 out_err_release: 1156 dst_release(*dst); 1157 *dst = NULL; 1158 1159 if (err == -ENETUNREACH) 1160 IP6_INC_STATS(net, NULL, IPSTATS_MIB_OUTNOROUTES); 1161 return err; 1162 } 1163 1164 /** 1165 * ip6_dst_lookup - perform route lookup on flow 1166 * @net: Network namespace to perform lookup in 1167 * @sk: socket which provides route info 1168 * @dst: pointer to dst_entry * for result 1169 * @fl6: flow to lookup 1170 * 1171 * This function performs a route lookup on the given flow. 1172 * 1173 * It returns zero on success, or a standard errno code on error. 1174 */ 1175 int ip6_dst_lookup(struct net *net, struct sock *sk, struct dst_entry **dst, 1176 struct flowi6 *fl6) 1177 { 1178 *dst = NULL; 1179 return ip6_dst_lookup_tail(net, sk, dst, fl6); 1180 } 1181 EXPORT_SYMBOL_GPL(ip6_dst_lookup); 1182 1183 /** 1184 * ip6_dst_lookup_flow - perform route lookup on flow with ipsec 1185 * @net: Network namespace to perform lookup in 1186 * @sk: socket which provides route info 1187 * @fl6: flow to lookup 1188 * @final_dst: final destination address for ipsec lookup 1189 * 1190 * This function performs a route lookup on the given flow. 1191 * 1192 * It returns a valid dst pointer on success, or a pointer encoded 1193 * error code. 1194 */ 1195 struct dst_entry *ip6_dst_lookup_flow(struct net *net, const struct sock *sk, struct flowi6 *fl6, 1196 const struct in6_addr *final_dst) 1197 { 1198 struct dst_entry *dst = NULL; 1199 int err; 1200 1201 err = ip6_dst_lookup_tail(net, sk, &dst, fl6); 1202 if (err) 1203 return ERR_PTR(err); 1204 if (final_dst) 1205 fl6->daddr = *final_dst; 1206 1207 return xfrm_lookup_route(net, dst, flowi6_to_flowi(fl6), sk, 0); 1208 } 1209 EXPORT_SYMBOL_GPL(ip6_dst_lookup_flow); 1210 1211 /** 1212 * ip6_sk_dst_lookup_flow - perform socket cached route lookup on flow 1213 * @sk: socket which provides the dst cache and route info 1214 * @fl6: flow to lookup 1215 * @final_dst: final destination address for ipsec lookup 1216 * @connected: whether @sk is connected or not 1217 * 1218 * This function performs a route lookup on the given flow with the 1219 * possibility of using the cached route in the socket if it is valid. 1220 * It will take the socket dst lock when operating on the dst cache. 1221 * As a result, this function can only be used in process context. 1222 * 1223 * In addition, for a connected socket, cache the dst in the socket 1224 * if the current cache is not valid. 1225 * 1226 * It returns a valid dst pointer on success, or a pointer encoded 1227 * error code. 1228 */ 1229 struct dst_entry *ip6_sk_dst_lookup_flow(struct sock *sk, struct flowi6 *fl6, 1230 const struct in6_addr *final_dst, 1231 bool connected) 1232 { 1233 struct dst_entry *dst = sk_dst_check(sk, inet6_sk(sk)->dst_cookie); 1234 1235 dst = ip6_sk_dst_check(sk, dst, fl6); 1236 if (dst) 1237 return dst; 1238 1239 dst = ip6_dst_lookup_flow(sock_net(sk), sk, fl6, final_dst); 1240 if (connected && !IS_ERR(dst)) 1241 ip6_sk_dst_store_flow(sk, dst_clone(dst), fl6); 1242 1243 return dst; 1244 } 1245 EXPORT_SYMBOL_GPL(ip6_sk_dst_lookup_flow); 1246 1247 /** 1248 * ip6_dst_lookup_tunnel - perform route lookup on tunnel 1249 * @skb: Packet for which lookup is done 1250 * @dev: Tunnel device 1251 * @net: Network namespace of tunnel device 1252 * @sock: Socket which provides route info 1253 * @saddr: Memory to store the src ip address 1254 * @info: Tunnel information 1255 * @protocol: IP protocol 1256 * @use_cache: Flag to enable cache usage 1257 * This function performs a route lookup on a tunnel 1258 * 1259 * It returns a valid dst pointer and stores src address to be used in 1260 * tunnel in param saddr on success, else a pointer encoded error code. 1261 */ 1262 1263 struct dst_entry *ip6_dst_lookup_tunnel(struct sk_buff *skb, 1264 struct net_device *dev, 1265 struct net *net, 1266 struct socket *sock, 1267 struct in6_addr *saddr, 1268 const struct ip_tunnel_info *info, 1269 u8 protocol, 1270 bool use_cache) 1271 { 1272 struct dst_entry *dst = NULL; 1273 #ifdef CONFIG_DST_CACHE 1274 struct dst_cache *dst_cache; 1275 #endif 1276 struct flowi6 fl6; 1277 __u8 prio; 1278 1279 #ifdef CONFIG_DST_CACHE 1280 dst_cache = (struct dst_cache *)&info->dst_cache; 1281 if (use_cache) { 1282 dst = dst_cache_get_ip6(dst_cache, saddr); 1283 if (dst) 1284 return dst; 1285 } 1286 #endif 1287 memset(&fl6, 0, sizeof(fl6)); 1288 fl6.flowi6_mark = skb->mark; 1289 fl6.flowi6_proto = protocol; 1290 fl6.daddr = info->key.u.ipv6.dst; 1291 fl6.saddr = info->key.u.ipv6.src; 1292 prio = info->key.tos; 1293 fl6.flowlabel = ip6_make_flowinfo(RT_TOS(prio), 1294 info->key.label); 1295 1296 dst = ipv6_stub->ipv6_dst_lookup_flow(net, sock->sk, &fl6, 1297 NULL); 1298 if (IS_ERR(dst)) { 1299 netdev_dbg(dev, "no route to %pI6\n", &fl6.daddr); 1300 return ERR_PTR(-ENETUNREACH); 1301 } 1302 if (dst->dev == dev) { /* is this necessary? */ 1303 netdev_dbg(dev, "circular route to %pI6\n", &fl6.daddr); 1304 dst_release(dst); 1305 return ERR_PTR(-ELOOP); 1306 } 1307 #ifdef CONFIG_DST_CACHE 1308 if (use_cache) 1309 dst_cache_set_ip6(dst_cache, dst, &fl6.saddr); 1310 #endif 1311 *saddr = fl6.saddr; 1312 return dst; 1313 } 1314 EXPORT_SYMBOL_GPL(ip6_dst_lookup_tunnel); 1315 1316 static inline struct ipv6_opt_hdr *ip6_opt_dup(struct ipv6_opt_hdr *src, 1317 gfp_t gfp) 1318 { 1319 return src ? kmemdup(src, (src->hdrlen + 1) * 8, gfp) : NULL; 1320 } 1321 1322 static inline struct ipv6_rt_hdr *ip6_rthdr_dup(struct ipv6_rt_hdr *src, 1323 gfp_t gfp) 1324 { 1325 return src ? kmemdup(src, (src->hdrlen + 1) * 8, gfp) : NULL; 1326 } 1327 1328 static void ip6_append_data_mtu(unsigned int *mtu, 1329 int *maxfraglen, 1330 unsigned int fragheaderlen, 1331 struct sk_buff *skb, 1332 struct rt6_info *rt, 1333 unsigned int orig_mtu) 1334 { 1335 if (!(rt->dst.flags & DST_XFRM_TUNNEL)) { 1336 if (!skb) { 1337 /* first fragment, reserve header_len */ 1338 *mtu = orig_mtu - rt->dst.header_len; 1339 1340 } else { 1341 /* 1342 * this fragment is not first, the headers 1343 * space is regarded as data space. 1344 */ 1345 *mtu = orig_mtu; 1346 } 1347 *maxfraglen = ((*mtu - fragheaderlen) & ~7) 1348 + fragheaderlen - sizeof(struct frag_hdr); 1349 } 1350 } 1351 1352 static int ip6_setup_cork(struct sock *sk, struct inet_cork_full *cork, 1353 struct inet6_cork *v6_cork, struct ipcm6_cookie *ipc6, 1354 struct rt6_info *rt) 1355 { 1356 struct ipv6_pinfo *np = inet6_sk(sk); 1357 unsigned int mtu; 1358 struct ipv6_txoptions *nopt, *opt = ipc6->opt; 1359 1360 /* callers pass dst together with a reference, set it first so 1361 * ip6_cork_release() can put it down even in case of an error. 1362 */ 1363 cork->base.dst = &rt->dst; 1364 1365 /* 1366 * setup for corking 1367 */ 1368 if (opt) { 1369 if (WARN_ON(v6_cork->opt)) 1370 return -EINVAL; 1371 1372 nopt = v6_cork->opt = kzalloc(sizeof(*opt), sk->sk_allocation); 1373 if (unlikely(!nopt)) 1374 return -ENOBUFS; 1375 1376 nopt->tot_len = sizeof(*opt); 1377 nopt->opt_flen = opt->opt_flen; 1378 nopt->opt_nflen = opt->opt_nflen; 1379 1380 nopt->dst0opt = ip6_opt_dup(opt->dst0opt, sk->sk_allocation); 1381 if (opt->dst0opt && !nopt->dst0opt) 1382 return -ENOBUFS; 1383 1384 nopt->dst1opt = ip6_opt_dup(opt->dst1opt, sk->sk_allocation); 1385 if (opt->dst1opt && !nopt->dst1opt) 1386 return -ENOBUFS; 1387 1388 nopt->hopopt = ip6_opt_dup(opt->hopopt, sk->sk_allocation); 1389 if (opt->hopopt && !nopt->hopopt) 1390 return -ENOBUFS; 1391 1392 nopt->srcrt = ip6_rthdr_dup(opt->srcrt, sk->sk_allocation); 1393 if (opt->srcrt && !nopt->srcrt) 1394 return -ENOBUFS; 1395 1396 /* need source address above miyazawa*/ 1397 } 1398 v6_cork->hop_limit = ipc6->hlimit; 1399 v6_cork->tclass = ipc6->tclass; 1400 if (rt->dst.flags & DST_XFRM_TUNNEL) 1401 mtu = np->pmtudisc >= IPV6_PMTUDISC_PROBE ? 1402 READ_ONCE(rt->dst.dev->mtu) : dst_mtu(&rt->dst); 1403 else 1404 mtu = np->pmtudisc >= IPV6_PMTUDISC_PROBE ? 1405 READ_ONCE(rt->dst.dev->mtu) : dst_mtu(xfrm_dst_path(&rt->dst)); 1406 if (np->frag_size < mtu) { 1407 if (np->frag_size) 1408 mtu = np->frag_size; 1409 } 1410 cork->base.fragsize = mtu; 1411 cork->base.gso_size = ipc6->gso_size; 1412 cork->base.tx_flags = 0; 1413 cork->base.mark = ipc6->sockc.mark; 1414 sock_tx_timestamp(sk, ipc6->sockc.tsflags, &cork->base.tx_flags); 1415 1416 if (dst_allfrag(xfrm_dst_path(&rt->dst))) 1417 cork->base.flags |= IPCORK_ALLFRAG; 1418 cork->base.length = 0; 1419 1420 cork->base.transmit_time = ipc6->sockc.transmit_time; 1421 1422 return 0; 1423 } 1424 1425 static int __ip6_append_data(struct sock *sk, 1426 struct sk_buff_head *queue, 1427 struct inet_cork_full *cork_full, 1428 struct inet6_cork *v6_cork, 1429 struct page_frag *pfrag, 1430 int getfrag(void *from, char *to, int offset, 1431 int len, int odd, struct sk_buff *skb), 1432 void *from, int length, int transhdrlen, 1433 unsigned int flags, struct ipcm6_cookie *ipc6) 1434 { 1435 struct sk_buff *skb, *skb_prev = NULL; 1436 struct inet_cork *cork = &cork_full->base; 1437 struct flowi6 *fl6 = &cork_full->fl.u.ip6; 1438 unsigned int maxfraglen, fragheaderlen, mtu, orig_mtu, pmtu; 1439 struct ubuf_info *uarg = NULL; 1440 int exthdrlen = 0; 1441 int dst_exthdrlen = 0; 1442 int hh_len; 1443 int copy; 1444 int err; 1445 int offset = 0; 1446 u32 tskey = 0; 1447 struct rt6_info *rt = (struct rt6_info *)cork->dst; 1448 struct ipv6_txoptions *opt = v6_cork->opt; 1449 int csummode = CHECKSUM_NONE; 1450 unsigned int maxnonfragsize, headersize; 1451 unsigned int wmem_alloc_delta = 0; 1452 bool paged, extra_uref = false; 1453 1454 skb = skb_peek_tail(queue); 1455 if (!skb) { 1456 exthdrlen = opt ? opt->opt_flen : 0; 1457 dst_exthdrlen = rt->dst.header_len - rt->rt6i_nfheader_len; 1458 } 1459 1460 paged = !!cork->gso_size; 1461 mtu = cork->gso_size ? IP6_MAX_MTU : cork->fragsize; 1462 orig_mtu = mtu; 1463 1464 if (cork->tx_flags & SKBTX_ANY_SW_TSTAMP && 1465 sk->sk_tsflags & SOF_TIMESTAMPING_OPT_ID) 1466 tskey = atomic_inc_return(&sk->sk_tskey) - 1; 1467 1468 hh_len = LL_RESERVED_SPACE(rt->dst.dev); 1469 1470 fragheaderlen = sizeof(struct ipv6hdr) + rt->rt6i_nfheader_len + 1471 (opt ? opt->opt_nflen : 0); 1472 1473 headersize = sizeof(struct ipv6hdr) + 1474 (opt ? opt->opt_flen + opt->opt_nflen : 0) + 1475 (dst_allfrag(&rt->dst) ? 1476 sizeof(struct frag_hdr) : 0) + 1477 rt->rt6i_nfheader_len; 1478 1479 if (mtu < fragheaderlen || 1480 ((mtu - fragheaderlen) & ~7) + fragheaderlen < sizeof(struct frag_hdr)) 1481 goto emsgsize; 1482 1483 maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen - 1484 sizeof(struct frag_hdr); 1485 1486 /* as per RFC 7112 section 5, the entire IPv6 Header Chain must fit 1487 * the first fragment 1488 */ 1489 if (headersize + transhdrlen > mtu) 1490 goto emsgsize; 1491 1492 if (cork->length + length > mtu - headersize && ipc6->dontfrag && 1493 (sk->sk_protocol == IPPROTO_UDP || 1494 sk->sk_protocol == IPPROTO_ICMPV6 || 1495 sk->sk_protocol == IPPROTO_RAW)) { 1496 ipv6_local_rxpmtu(sk, fl6, mtu - headersize + 1497 sizeof(struct ipv6hdr)); 1498 goto emsgsize; 1499 } 1500 1501 if (ip6_sk_ignore_df(sk)) 1502 maxnonfragsize = sizeof(struct ipv6hdr) + IPV6_MAXPLEN; 1503 else 1504 maxnonfragsize = mtu; 1505 1506 if (cork->length + length > maxnonfragsize - headersize) { 1507 emsgsize: 1508 pmtu = max_t(int, mtu - headersize + sizeof(struct ipv6hdr), 0); 1509 ipv6_local_error(sk, EMSGSIZE, fl6, pmtu); 1510 return -EMSGSIZE; 1511 } 1512 1513 /* CHECKSUM_PARTIAL only with no extension headers and when 1514 * we are not going to fragment 1515 */ 1516 if (transhdrlen && sk->sk_protocol == IPPROTO_UDP && 1517 headersize == sizeof(struct ipv6hdr) && 1518 length <= mtu - headersize && 1519 (!(flags & MSG_MORE) || cork->gso_size) && 1520 rt->dst.dev->features & (NETIF_F_IPV6_CSUM | NETIF_F_HW_CSUM)) 1521 csummode = CHECKSUM_PARTIAL; 1522 1523 if (flags & MSG_ZEROCOPY && length && sock_flag(sk, SOCK_ZEROCOPY)) { 1524 uarg = msg_zerocopy_realloc(sk, length, skb_zcopy(skb)); 1525 if (!uarg) 1526 return -ENOBUFS; 1527 extra_uref = !skb_zcopy(skb); /* only ref on new uarg */ 1528 if (rt->dst.dev->features & NETIF_F_SG && 1529 csummode == CHECKSUM_PARTIAL) { 1530 paged = true; 1531 } else { 1532 uarg->zerocopy = 0; 1533 skb_zcopy_set(skb, uarg, &extra_uref); 1534 } 1535 } 1536 1537 /* 1538 * Let's try using as much space as possible. 1539 * Use MTU if total length of the message fits into the MTU. 1540 * Otherwise, we need to reserve fragment header and 1541 * fragment alignment (= 8-15 octects, in total). 1542 * 1543 * Note that we may need to "move" the data from the tail 1544 * of the buffer to the new fragment when we split 1545 * the message. 1546 * 1547 * FIXME: It may be fragmented into multiple chunks 1548 * at once if non-fragmentable extension headers 1549 * are too large. 1550 * --yoshfuji 1551 */ 1552 1553 cork->length += length; 1554 if (!skb) 1555 goto alloc_new_skb; 1556 1557 while (length > 0) { 1558 /* Check if the remaining data fits into current packet. */ 1559 copy = (cork->length <= mtu && !(cork->flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - skb->len; 1560 if (copy < length) 1561 copy = maxfraglen - skb->len; 1562 1563 if (copy <= 0) { 1564 char *data; 1565 unsigned int datalen; 1566 unsigned int fraglen; 1567 unsigned int fraggap; 1568 unsigned int alloclen, alloc_extra; 1569 unsigned int pagedlen; 1570 alloc_new_skb: 1571 /* There's no room in the current skb */ 1572 if (skb) 1573 fraggap = skb->len - maxfraglen; 1574 else 1575 fraggap = 0; 1576 /* update mtu and maxfraglen if necessary */ 1577 if (!skb || !skb_prev) 1578 ip6_append_data_mtu(&mtu, &maxfraglen, 1579 fragheaderlen, skb, rt, 1580 orig_mtu); 1581 1582 skb_prev = skb; 1583 1584 /* 1585 * If remaining data exceeds the mtu, 1586 * we know we need more fragment(s). 1587 */ 1588 datalen = length + fraggap; 1589 1590 if (datalen > (cork->length <= mtu && !(cork->flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - fragheaderlen) 1591 datalen = maxfraglen - fragheaderlen - rt->dst.trailer_len; 1592 fraglen = datalen + fragheaderlen; 1593 pagedlen = 0; 1594 1595 alloc_extra = hh_len; 1596 alloc_extra += dst_exthdrlen; 1597 alloc_extra += rt->dst.trailer_len; 1598 1599 /* We just reserve space for fragment header. 1600 * Note: this may be overallocation if the message 1601 * (without MSG_MORE) fits into the MTU. 1602 */ 1603 alloc_extra += sizeof(struct frag_hdr); 1604 1605 if ((flags & MSG_MORE) && 1606 !(rt->dst.dev->features&NETIF_F_SG)) 1607 alloclen = mtu; 1608 else if (!paged && 1609 (fraglen + alloc_extra < SKB_MAX_ALLOC || 1610 !(rt->dst.dev->features & NETIF_F_SG))) 1611 alloclen = fraglen; 1612 else { 1613 alloclen = min_t(int, fraglen, MAX_HEADER); 1614 pagedlen = fraglen - alloclen; 1615 } 1616 alloclen += alloc_extra; 1617 1618 if (datalen != length + fraggap) { 1619 /* 1620 * this is not the last fragment, the trailer 1621 * space is regarded as data space. 1622 */ 1623 datalen += rt->dst.trailer_len; 1624 } 1625 1626 fraglen = datalen + fragheaderlen; 1627 1628 copy = datalen - transhdrlen - fraggap - pagedlen; 1629 if (copy < 0) { 1630 err = -EINVAL; 1631 goto error; 1632 } 1633 if (transhdrlen) { 1634 skb = sock_alloc_send_skb(sk, alloclen, 1635 (flags & MSG_DONTWAIT), &err); 1636 } else { 1637 skb = NULL; 1638 if (refcount_read(&sk->sk_wmem_alloc) + wmem_alloc_delta <= 1639 2 * sk->sk_sndbuf) 1640 skb = alloc_skb(alloclen, 1641 sk->sk_allocation); 1642 if (unlikely(!skb)) 1643 err = -ENOBUFS; 1644 } 1645 if (!skb) 1646 goto error; 1647 /* 1648 * Fill in the control structures 1649 */ 1650 skb->protocol = htons(ETH_P_IPV6); 1651 skb->ip_summed = csummode; 1652 skb->csum = 0; 1653 /* reserve for fragmentation and ipsec header */ 1654 skb_reserve(skb, hh_len + sizeof(struct frag_hdr) + 1655 dst_exthdrlen); 1656 1657 /* 1658 * Find where to start putting bytes 1659 */ 1660 data = skb_put(skb, fraglen - pagedlen); 1661 skb_set_network_header(skb, exthdrlen); 1662 data += fragheaderlen; 1663 skb->transport_header = (skb->network_header + 1664 fragheaderlen); 1665 if (fraggap) { 1666 skb->csum = skb_copy_and_csum_bits( 1667 skb_prev, maxfraglen, 1668 data + transhdrlen, fraggap); 1669 skb_prev->csum = csum_sub(skb_prev->csum, 1670 skb->csum); 1671 data += fraggap; 1672 pskb_trim_unique(skb_prev, maxfraglen); 1673 } 1674 if (copy > 0 && 1675 getfrag(from, data + transhdrlen, offset, 1676 copy, fraggap, skb) < 0) { 1677 err = -EFAULT; 1678 kfree_skb(skb); 1679 goto error; 1680 } 1681 1682 offset += copy; 1683 length -= copy + transhdrlen; 1684 transhdrlen = 0; 1685 exthdrlen = 0; 1686 dst_exthdrlen = 0; 1687 1688 /* Only the initial fragment is time stamped */ 1689 skb_shinfo(skb)->tx_flags = cork->tx_flags; 1690 cork->tx_flags = 0; 1691 skb_shinfo(skb)->tskey = tskey; 1692 tskey = 0; 1693 skb_zcopy_set(skb, uarg, &extra_uref); 1694 1695 if ((flags & MSG_CONFIRM) && !skb_prev) 1696 skb_set_dst_pending_confirm(skb, 1); 1697 1698 /* 1699 * Put the packet on the pending queue 1700 */ 1701 if (!skb->destructor) { 1702 skb->destructor = sock_wfree; 1703 skb->sk = sk; 1704 wmem_alloc_delta += skb->truesize; 1705 } 1706 __skb_queue_tail(queue, skb); 1707 continue; 1708 } 1709 1710 if (copy > length) 1711 copy = length; 1712 1713 if (!(rt->dst.dev->features&NETIF_F_SG) && 1714 skb_tailroom(skb) >= copy) { 1715 unsigned int off; 1716 1717 off = skb->len; 1718 if (getfrag(from, skb_put(skb, copy), 1719 offset, copy, off, skb) < 0) { 1720 __skb_trim(skb, off); 1721 err = -EFAULT; 1722 goto error; 1723 } 1724 } else if (!uarg || !uarg->zerocopy) { 1725 int i = skb_shinfo(skb)->nr_frags; 1726 1727 err = -ENOMEM; 1728 if (!sk_page_frag_refill(sk, pfrag)) 1729 goto error; 1730 1731 if (!skb_can_coalesce(skb, i, pfrag->page, 1732 pfrag->offset)) { 1733 err = -EMSGSIZE; 1734 if (i == MAX_SKB_FRAGS) 1735 goto error; 1736 1737 __skb_fill_page_desc(skb, i, pfrag->page, 1738 pfrag->offset, 0); 1739 skb_shinfo(skb)->nr_frags = ++i; 1740 get_page(pfrag->page); 1741 } 1742 copy = min_t(int, copy, pfrag->size - pfrag->offset); 1743 if (getfrag(from, 1744 page_address(pfrag->page) + pfrag->offset, 1745 offset, copy, skb->len, skb) < 0) 1746 goto error_efault; 1747 1748 pfrag->offset += copy; 1749 skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], copy); 1750 skb->len += copy; 1751 skb->data_len += copy; 1752 skb->truesize += copy; 1753 wmem_alloc_delta += copy; 1754 } else { 1755 err = skb_zerocopy_iter_dgram(skb, from, copy); 1756 if (err < 0) 1757 goto error; 1758 } 1759 offset += copy; 1760 length -= copy; 1761 } 1762 1763 if (wmem_alloc_delta) 1764 refcount_add(wmem_alloc_delta, &sk->sk_wmem_alloc); 1765 return 0; 1766 1767 error_efault: 1768 err = -EFAULT; 1769 error: 1770 net_zcopy_put_abort(uarg, extra_uref); 1771 cork->length -= length; 1772 IP6_INC_STATS(sock_net(sk), rt->rt6i_idev, IPSTATS_MIB_OUTDISCARDS); 1773 refcount_add(wmem_alloc_delta, &sk->sk_wmem_alloc); 1774 return err; 1775 } 1776 1777 int ip6_append_data(struct sock *sk, 1778 int getfrag(void *from, char *to, int offset, int len, 1779 int odd, struct sk_buff *skb), 1780 void *from, int length, int transhdrlen, 1781 struct ipcm6_cookie *ipc6, struct flowi6 *fl6, 1782 struct rt6_info *rt, unsigned int flags) 1783 { 1784 struct inet_sock *inet = inet_sk(sk); 1785 struct ipv6_pinfo *np = inet6_sk(sk); 1786 int exthdrlen; 1787 int err; 1788 1789 if (flags&MSG_PROBE) 1790 return 0; 1791 if (skb_queue_empty(&sk->sk_write_queue)) { 1792 /* 1793 * setup for corking 1794 */ 1795 dst_hold(&rt->dst); 1796 err = ip6_setup_cork(sk, &inet->cork, &np->cork, 1797 ipc6, rt); 1798 if (err) 1799 return err; 1800 1801 inet->cork.fl.u.ip6 = *fl6; 1802 exthdrlen = (ipc6->opt ? ipc6->opt->opt_flen : 0); 1803 length += exthdrlen; 1804 transhdrlen += exthdrlen; 1805 } else { 1806 transhdrlen = 0; 1807 } 1808 1809 return __ip6_append_data(sk, &sk->sk_write_queue, &inet->cork, 1810 &np->cork, sk_page_frag(sk), getfrag, 1811 from, length, transhdrlen, flags, ipc6); 1812 } 1813 EXPORT_SYMBOL_GPL(ip6_append_data); 1814 1815 static void ip6_cork_steal_dst(struct sk_buff *skb, struct inet_cork_full *cork) 1816 { 1817 struct dst_entry *dst = cork->base.dst; 1818 1819 cork->base.dst = NULL; 1820 cork->base.flags &= ~IPCORK_ALLFRAG; 1821 skb_dst_set(skb, dst); 1822 } 1823 1824 static void ip6_cork_release(struct inet_cork_full *cork, 1825 struct inet6_cork *v6_cork) 1826 { 1827 if (v6_cork->opt) { 1828 struct ipv6_txoptions *opt = v6_cork->opt; 1829 1830 kfree(opt->dst0opt); 1831 kfree(opt->dst1opt); 1832 kfree(opt->hopopt); 1833 kfree(opt->srcrt); 1834 kfree(opt); 1835 v6_cork->opt = NULL; 1836 } 1837 1838 if (cork->base.dst) { 1839 dst_release(cork->base.dst); 1840 cork->base.dst = NULL; 1841 cork->base.flags &= ~IPCORK_ALLFRAG; 1842 } 1843 } 1844 1845 struct sk_buff *__ip6_make_skb(struct sock *sk, 1846 struct sk_buff_head *queue, 1847 struct inet_cork_full *cork, 1848 struct inet6_cork *v6_cork) 1849 { 1850 struct sk_buff *skb, *tmp_skb; 1851 struct sk_buff **tail_skb; 1852 struct in6_addr *final_dst; 1853 struct ipv6_pinfo *np = inet6_sk(sk); 1854 struct net *net = sock_net(sk); 1855 struct ipv6hdr *hdr; 1856 struct ipv6_txoptions *opt = v6_cork->opt; 1857 struct rt6_info *rt = (struct rt6_info *)cork->base.dst; 1858 struct flowi6 *fl6 = &cork->fl.u.ip6; 1859 unsigned char proto = fl6->flowi6_proto; 1860 1861 skb = __skb_dequeue(queue); 1862 if (!skb) 1863 goto out; 1864 tail_skb = &(skb_shinfo(skb)->frag_list); 1865 1866 /* move skb->data to ip header from ext header */ 1867 if (skb->data < skb_network_header(skb)) 1868 __skb_pull(skb, skb_network_offset(skb)); 1869 while ((tmp_skb = __skb_dequeue(queue)) != NULL) { 1870 __skb_pull(tmp_skb, skb_network_header_len(skb)); 1871 *tail_skb = tmp_skb; 1872 tail_skb = &(tmp_skb->next); 1873 skb->len += tmp_skb->len; 1874 skb->data_len += tmp_skb->len; 1875 skb->truesize += tmp_skb->truesize; 1876 tmp_skb->destructor = NULL; 1877 tmp_skb->sk = NULL; 1878 } 1879 1880 /* Allow local fragmentation. */ 1881 skb->ignore_df = ip6_sk_ignore_df(sk); 1882 __skb_pull(skb, skb_network_header_len(skb)); 1883 1884 final_dst = &fl6->daddr; 1885 if (opt && opt->opt_flen) 1886 ipv6_push_frag_opts(skb, opt, &proto); 1887 if (opt && opt->opt_nflen) 1888 ipv6_push_nfrag_opts(skb, opt, &proto, &final_dst, &fl6->saddr); 1889 1890 skb_push(skb, sizeof(struct ipv6hdr)); 1891 skb_reset_network_header(skb); 1892 hdr = ipv6_hdr(skb); 1893 1894 ip6_flow_hdr(hdr, v6_cork->tclass, 1895 ip6_make_flowlabel(net, skb, fl6->flowlabel, 1896 ip6_autoflowlabel(net, np), fl6)); 1897 hdr->hop_limit = v6_cork->hop_limit; 1898 hdr->nexthdr = proto; 1899 hdr->saddr = fl6->saddr; 1900 hdr->daddr = *final_dst; 1901 1902 skb->priority = sk->sk_priority; 1903 skb->mark = cork->base.mark; 1904 skb->tstamp = cork->base.transmit_time; 1905 1906 ip6_cork_steal_dst(skb, cork); 1907 IP6_UPD_PO_STATS(net, rt->rt6i_idev, IPSTATS_MIB_OUT, skb->len); 1908 if (proto == IPPROTO_ICMPV6) { 1909 struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb)); 1910 1911 ICMP6MSGOUT_INC_STATS(net, idev, icmp6_hdr(skb)->icmp6_type); 1912 ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTMSGS); 1913 } 1914 1915 ip6_cork_release(cork, v6_cork); 1916 out: 1917 return skb; 1918 } 1919 1920 int ip6_send_skb(struct sk_buff *skb) 1921 { 1922 struct net *net = sock_net(skb->sk); 1923 struct rt6_info *rt = (struct rt6_info *)skb_dst(skb); 1924 int err; 1925 1926 err = ip6_local_out(net, skb->sk, skb); 1927 if (err) { 1928 if (err > 0) 1929 err = net_xmit_errno(err); 1930 if (err) 1931 IP6_INC_STATS(net, rt->rt6i_idev, 1932 IPSTATS_MIB_OUTDISCARDS); 1933 } 1934 1935 return err; 1936 } 1937 1938 int ip6_push_pending_frames(struct sock *sk) 1939 { 1940 struct sk_buff *skb; 1941 1942 skb = ip6_finish_skb(sk); 1943 if (!skb) 1944 return 0; 1945 1946 return ip6_send_skb(skb); 1947 } 1948 EXPORT_SYMBOL_GPL(ip6_push_pending_frames); 1949 1950 static void __ip6_flush_pending_frames(struct sock *sk, 1951 struct sk_buff_head *queue, 1952 struct inet_cork_full *cork, 1953 struct inet6_cork *v6_cork) 1954 { 1955 struct sk_buff *skb; 1956 1957 while ((skb = __skb_dequeue_tail(queue)) != NULL) { 1958 if (skb_dst(skb)) 1959 IP6_INC_STATS(sock_net(sk), ip6_dst_idev(skb_dst(skb)), 1960 IPSTATS_MIB_OUTDISCARDS); 1961 kfree_skb(skb); 1962 } 1963 1964 ip6_cork_release(cork, v6_cork); 1965 } 1966 1967 void ip6_flush_pending_frames(struct sock *sk) 1968 { 1969 __ip6_flush_pending_frames(sk, &sk->sk_write_queue, 1970 &inet_sk(sk)->cork, &inet6_sk(sk)->cork); 1971 } 1972 EXPORT_SYMBOL_GPL(ip6_flush_pending_frames); 1973 1974 struct sk_buff *ip6_make_skb(struct sock *sk, 1975 int getfrag(void *from, char *to, int offset, 1976 int len, int odd, struct sk_buff *skb), 1977 void *from, int length, int transhdrlen, 1978 struct ipcm6_cookie *ipc6, struct rt6_info *rt, 1979 unsigned int flags, struct inet_cork_full *cork) 1980 { 1981 struct inet6_cork v6_cork; 1982 struct sk_buff_head queue; 1983 int exthdrlen = (ipc6->opt ? ipc6->opt->opt_flen : 0); 1984 int err; 1985 1986 if (flags & MSG_PROBE) { 1987 dst_release(&rt->dst); 1988 return NULL; 1989 } 1990 1991 __skb_queue_head_init(&queue); 1992 1993 cork->base.flags = 0; 1994 cork->base.addr = 0; 1995 cork->base.opt = NULL; 1996 v6_cork.opt = NULL; 1997 err = ip6_setup_cork(sk, cork, &v6_cork, ipc6, rt); 1998 if (err) { 1999 ip6_cork_release(cork, &v6_cork); 2000 return ERR_PTR(err); 2001 } 2002 if (ipc6->dontfrag < 0) 2003 ipc6->dontfrag = inet6_sk(sk)->dontfrag; 2004 2005 err = __ip6_append_data(sk, &queue, cork, &v6_cork, 2006 ¤t->task_frag, getfrag, from, 2007 length + exthdrlen, transhdrlen + exthdrlen, 2008 flags, ipc6); 2009 if (err) { 2010 __ip6_flush_pending_frames(sk, &queue, cork, &v6_cork); 2011 return ERR_PTR(err); 2012 } 2013 2014 return __ip6_make_skb(sk, &queue, cork, &v6_cork); 2015 } 2016