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_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 cork->base.fragsize = mtu; 1410 cork->base.gso_size = ipc6->gso_size; 1411 cork->base.tx_flags = 0; 1412 cork->base.mark = ipc6->sockc.mark; 1413 sock_tx_timestamp(sk, ipc6->sockc.tsflags, &cork->base.tx_flags); 1414 1415 if (dst_allfrag(xfrm_dst_path(&rt->dst))) 1416 cork->base.flags |= IPCORK_ALLFRAG; 1417 cork->base.length = 0; 1418 1419 cork->base.transmit_time = ipc6->sockc.transmit_time; 1420 1421 return 0; 1422 } 1423 1424 static int __ip6_append_data(struct sock *sk, 1425 struct sk_buff_head *queue, 1426 struct inet_cork_full *cork_full, 1427 struct inet6_cork *v6_cork, 1428 struct page_frag *pfrag, 1429 int getfrag(void *from, char *to, int offset, 1430 int len, int odd, struct sk_buff *skb), 1431 void *from, int length, int transhdrlen, 1432 unsigned int flags, struct ipcm6_cookie *ipc6) 1433 { 1434 struct sk_buff *skb, *skb_prev = NULL; 1435 struct inet_cork *cork = &cork_full->base; 1436 struct flowi6 *fl6 = &cork_full->fl.u.ip6; 1437 unsigned int maxfraglen, fragheaderlen, mtu, orig_mtu, pmtu; 1438 struct ubuf_info *uarg = NULL; 1439 int exthdrlen = 0; 1440 int dst_exthdrlen = 0; 1441 int hh_len; 1442 int copy; 1443 int err; 1444 int offset = 0; 1445 u32 tskey = 0; 1446 struct rt6_info *rt = (struct rt6_info *)cork->dst; 1447 struct ipv6_txoptions *opt = v6_cork->opt; 1448 int csummode = CHECKSUM_NONE; 1449 unsigned int maxnonfragsize, headersize; 1450 unsigned int wmem_alloc_delta = 0; 1451 bool paged, extra_uref = false; 1452 1453 skb = skb_peek_tail(queue); 1454 if (!skb) { 1455 exthdrlen = opt ? opt->opt_flen : 0; 1456 dst_exthdrlen = rt->dst.header_len - rt->rt6i_nfheader_len; 1457 } 1458 1459 paged = !!cork->gso_size; 1460 mtu = cork->gso_size ? IP6_MAX_MTU : cork->fragsize; 1461 orig_mtu = mtu; 1462 1463 if (cork->tx_flags & SKBTX_ANY_SW_TSTAMP && 1464 sk->sk_tsflags & SOF_TIMESTAMPING_OPT_ID) 1465 tskey = atomic_inc_return(&sk->sk_tskey) - 1; 1466 1467 hh_len = LL_RESERVED_SPACE(rt->dst.dev); 1468 1469 fragheaderlen = sizeof(struct ipv6hdr) + rt->rt6i_nfheader_len + 1470 (opt ? opt->opt_nflen : 0); 1471 1472 headersize = sizeof(struct ipv6hdr) + 1473 (opt ? opt->opt_flen + opt->opt_nflen : 0) + 1474 (dst_allfrag(&rt->dst) ? 1475 sizeof(struct frag_hdr) : 0) + 1476 rt->rt6i_nfheader_len; 1477 1478 if (mtu <= fragheaderlen || 1479 ((mtu - fragheaderlen) & ~7) + fragheaderlen <= sizeof(struct frag_hdr)) 1480 goto emsgsize; 1481 1482 maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen - 1483 sizeof(struct frag_hdr); 1484 1485 /* as per RFC 7112 section 5, the entire IPv6 Header Chain must fit 1486 * the first fragment 1487 */ 1488 if (headersize + transhdrlen > mtu) 1489 goto emsgsize; 1490 1491 if (cork->length + length > mtu - headersize && ipc6->dontfrag && 1492 (sk->sk_protocol == IPPROTO_UDP || 1493 sk->sk_protocol == IPPROTO_ICMPV6 || 1494 sk->sk_protocol == IPPROTO_RAW)) { 1495 ipv6_local_rxpmtu(sk, fl6, mtu - headersize + 1496 sizeof(struct ipv6hdr)); 1497 goto emsgsize; 1498 } 1499 1500 if (ip6_sk_ignore_df(sk)) 1501 maxnonfragsize = sizeof(struct ipv6hdr) + IPV6_MAXPLEN; 1502 else 1503 maxnonfragsize = mtu; 1504 1505 if (cork->length + length > maxnonfragsize - headersize) { 1506 emsgsize: 1507 pmtu = max_t(int, mtu - headersize + sizeof(struct ipv6hdr), 0); 1508 ipv6_local_error(sk, EMSGSIZE, fl6, pmtu); 1509 return -EMSGSIZE; 1510 } 1511 1512 /* CHECKSUM_PARTIAL only with no extension headers and when 1513 * we are not going to fragment 1514 */ 1515 if (transhdrlen && sk->sk_protocol == IPPROTO_UDP && 1516 headersize == sizeof(struct ipv6hdr) && 1517 length <= mtu - headersize && 1518 (!(flags & MSG_MORE) || cork->gso_size) && 1519 rt->dst.dev->features & (NETIF_F_IPV6_CSUM | NETIF_F_HW_CSUM)) 1520 csummode = CHECKSUM_PARTIAL; 1521 1522 if (flags & MSG_ZEROCOPY && length && sock_flag(sk, SOCK_ZEROCOPY)) { 1523 uarg = msg_zerocopy_realloc(sk, length, skb_zcopy(skb)); 1524 if (!uarg) 1525 return -ENOBUFS; 1526 extra_uref = !skb_zcopy(skb); /* only ref on new uarg */ 1527 if (rt->dst.dev->features & NETIF_F_SG && 1528 csummode == CHECKSUM_PARTIAL) { 1529 paged = true; 1530 } else { 1531 uarg->zerocopy = 0; 1532 skb_zcopy_set(skb, uarg, &extra_uref); 1533 } 1534 } 1535 1536 /* 1537 * Let's try using as much space as possible. 1538 * Use MTU if total length of the message fits into the MTU. 1539 * Otherwise, we need to reserve fragment header and 1540 * fragment alignment (= 8-15 octects, in total). 1541 * 1542 * Note that we may need to "move" the data from the tail 1543 * of the buffer to the new fragment when we split 1544 * the message. 1545 * 1546 * FIXME: It may be fragmented into multiple chunks 1547 * at once if non-fragmentable extension headers 1548 * are too large. 1549 * --yoshfuji 1550 */ 1551 1552 cork->length += length; 1553 if (!skb) 1554 goto alloc_new_skb; 1555 1556 while (length > 0) { 1557 /* Check if the remaining data fits into current packet. */ 1558 copy = (cork->length <= mtu && !(cork->flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - skb->len; 1559 if (copy < length) 1560 copy = maxfraglen - skb->len; 1561 1562 if (copy <= 0) { 1563 char *data; 1564 unsigned int datalen; 1565 unsigned int fraglen; 1566 unsigned int fraggap; 1567 unsigned int alloclen, alloc_extra; 1568 unsigned int pagedlen; 1569 alloc_new_skb: 1570 /* There's no room in the current skb */ 1571 if (skb) 1572 fraggap = skb->len - maxfraglen; 1573 else 1574 fraggap = 0; 1575 /* update mtu and maxfraglen if necessary */ 1576 if (!skb || !skb_prev) 1577 ip6_append_data_mtu(&mtu, &maxfraglen, 1578 fragheaderlen, skb, rt, 1579 orig_mtu); 1580 1581 skb_prev = skb; 1582 1583 /* 1584 * If remaining data exceeds the mtu, 1585 * we know we need more fragment(s). 1586 */ 1587 datalen = length + fraggap; 1588 1589 if (datalen > (cork->length <= mtu && !(cork->flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - fragheaderlen) 1590 datalen = maxfraglen - fragheaderlen - rt->dst.trailer_len; 1591 fraglen = datalen + fragheaderlen; 1592 pagedlen = 0; 1593 1594 alloc_extra = hh_len; 1595 alloc_extra += dst_exthdrlen; 1596 alloc_extra += rt->dst.trailer_len; 1597 1598 /* We just reserve space for fragment header. 1599 * Note: this may be overallocation if the message 1600 * (without MSG_MORE) fits into the MTU. 1601 */ 1602 alloc_extra += sizeof(struct frag_hdr); 1603 1604 if ((flags & MSG_MORE) && 1605 !(rt->dst.dev->features&NETIF_F_SG)) 1606 alloclen = mtu; 1607 else if (!paged && 1608 (fraglen + alloc_extra < SKB_MAX_ALLOC || 1609 !(rt->dst.dev->features & NETIF_F_SG))) 1610 alloclen = fraglen; 1611 else { 1612 alloclen = min_t(int, fraglen, MAX_HEADER); 1613 pagedlen = fraglen - alloclen; 1614 } 1615 alloclen += alloc_extra; 1616 1617 if (datalen != length + fraggap) { 1618 /* 1619 * this is not the last fragment, the trailer 1620 * space is regarded as data space. 1621 */ 1622 datalen += rt->dst.trailer_len; 1623 } 1624 1625 fraglen = datalen + fragheaderlen; 1626 1627 copy = datalen - transhdrlen - fraggap - pagedlen; 1628 if (copy < 0) { 1629 err = -EINVAL; 1630 goto error; 1631 } 1632 if (transhdrlen) { 1633 skb = sock_alloc_send_skb(sk, alloclen, 1634 (flags & MSG_DONTWAIT), &err); 1635 } else { 1636 skb = NULL; 1637 if (refcount_read(&sk->sk_wmem_alloc) + wmem_alloc_delta <= 1638 2 * sk->sk_sndbuf) 1639 skb = alloc_skb(alloclen, 1640 sk->sk_allocation); 1641 if (unlikely(!skb)) 1642 err = -ENOBUFS; 1643 } 1644 if (!skb) 1645 goto error; 1646 /* 1647 * Fill in the control structures 1648 */ 1649 skb->protocol = htons(ETH_P_IPV6); 1650 skb->ip_summed = csummode; 1651 skb->csum = 0; 1652 /* reserve for fragmentation and ipsec header */ 1653 skb_reserve(skb, hh_len + sizeof(struct frag_hdr) + 1654 dst_exthdrlen); 1655 1656 /* 1657 * Find where to start putting bytes 1658 */ 1659 data = skb_put(skb, fraglen - pagedlen); 1660 skb_set_network_header(skb, exthdrlen); 1661 data += fragheaderlen; 1662 skb->transport_header = (skb->network_header + 1663 fragheaderlen); 1664 if (fraggap) { 1665 skb->csum = skb_copy_and_csum_bits( 1666 skb_prev, maxfraglen, 1667 data + transhdrlen, fraggap); 1668 skb_prev->csum = csum_sub(skb_prev->csum, 1669 skb->csum); 1670 data += fraggap; 1671 pskb_trim_unique(skb_prev, maxfraglen); 1672 } 1673 if (copy > 0 && 1674 getfrag(from, data + transhdrlen, offset, 1675 copy, fraggap, skb) < 0) { 1676 err = -EFAULT; 1677 kfree_skb(skb); 1678 goto error; 1679 } 1680 1681 offset += copy; 1682 length -= copy + transhdrlen; 1683 transhdrlen = 0; 1684 exthdrlen = 0; 1685 dst_exthdrlen = 0; 1686 1687 /* Only the initial fragment is time stamped */ 1688 skb_shinfo(skb)->tx_flags = cork->tx_flags; 1689 cork->tx_flags = 0; 1690 skb_shinfo(skb)->tskey = tskey; 1691 tskey = 0; 1692 skb_zcopy_set(skb, uarg, &extra_uref); 1693 1694 if ((flags & MSG_CONFIRM) && !skb_prev) 1695 skb_set_dst_pending_confirm(skb, 1); 1696 1697 /* 1698 * Put the packet on the pending queue 1699 */ 1700 if (!skb->destructor) { 1701 skb->destructor = sock_wfree; 1702 skb->sk = sk; 1703 wmem_alloc_delta += skb->truesize; 1704 } 1705 __skb_queue_tail(queue, skb); 1706 continue; 1707 } 1708 1709 if (copy > length) 1710 copy = length; 1711 1712 if (!(rt->dst.dev->features&NETIF_F_SG) && 1713 skb_tailroom(skb) >= copy) { 1714 unsigned int off; 1715 1716 off = skb->len; 1717 if (getfrag(from, skb_put(skb, copy), 1718 offset, copy, off, skb) < 0) { 1719 __skb_trim(skb, off); 1720 err = -EFAULT; 1721 goto error; 1722 } 1723 } else if (!uarg || !uarg->zerocopy) { 1724 int i = skb_shinfo(skb)->nr_frags; 1725 1726 err = -ENOMEM; 1727 if (!sk_page_frag_refill(sk, pfrag)) 1728 goto error; 1729 1730 if (!skb_can_coalesce(skb, i, pfrag->page, 1731 pfrag->offset)) { 1732 err = -EMSGSIZE; 1733 if (i == MAX_SKB_FRAGS) 1734 goto error; 1735 1736 __skb_fill_page_desc(skb, i, pfrag->page, 1737 pfrag->offset, 0); 1738 skb_shinfo(skb)->nr_frags = ++i; 1739 get_page(pfrag->page); 1740 } 1741 copy = min_t(int, copy, pfrag->size - pfrag->offset); 1742 if (getfrag(from, 1743 page_address(pfrag->page) + pfrag->offset, 1744 offset, copy, skb->len, skb) < 0) 1745 goto error_efault; 1746 1747 pfrag->offset += copy; 1748 skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], copy); 1749 skb->len += copy; 1750 skb->data_len += copy; 1751 skb->truesize += copy; 1752 wmem_alloc_delta += copy; 1753 } else { 1754 err = skb_zerocopy_iter_dgram(skb, from, copy); 1755 if (err < 0) 1756 goto error; 1757 } 1758 offset += copy; 1759 length -= copy; 1760 } 1761 1762 if (wmem_alloc_delta) 1763 refcount_add(wmem_alloc_delta, &sk->sk_wmem_alloc); 1764 return 0; 1765 1766 error_efault: 1767 err = -EFAULT; 1768 error: 1769 net_zcopy_put_abort(uarg, extra_uref); 1770 cork->length -= length; 1771 IP6_INC_STATS(sock_net(sk), rt->rt6i_idev, IPSTATS_MIB_OUTDISCARDS); 1772 refcount_add(wmem_alloc_delta, &sk->sk_wmem_alloc); 1773 return err; 1774 } 1775 1776 int ip6_append_data(struct sock *sk, 1777 int getfrag(void *from, char *to, int offset, int len, 1778 int odd, struct sk_buff *skb), 1779 void *from, int length, int transhdrlen, 1780 struct ipcm6_cookie *ipc6, struct flowi6 *fl6, 1781 struct rt6_info *rt, unsigned int flags) 1782 { 1783 struct inet_sock *inet = inet_sk(sk); 1784 struct ipv6_pinfo *np = inet6_sk(sk); 1785 int exthdrlen; 1786 int err; 1787 1788 if (flags&MSG_PROBE) 1789 return 0; 1790 if (skb_queue_empty(&sk->sk_write_queue)) { 1791 /* 1792 * setup for corking 1793 */ 1794 dst_hold(&rt->dst); 1795 err = ip6_setup_cork(sk, &inet->cork, &np->cork, 1796 ipc6, rt); 1797 if (err) 1798 return err; 1799 1800 inet->cork.fl.u.ip6 = *fl6; 1801 exthdrlen = (ipc6->opt ? ipc6->opt->opt_flen : 0); 1802 length += exthdrlen; 1803 transhdrlen += exthdrlen; 1804 } else { 1805 transhdrlen = 0; 1806 } 1807 1808 return __ip6_append_data(sk, &sk->sk_write_queue, &inet->cork, 1809 &np->cork, sk_page_frag(sk), getfrag, 1810 from, length, transhdrlen, flags, ipc6); 1811 } 1812 EXPORT_SYMBOL_GPL(ip6_append_data); 1813 1814 static void ip6_cork_steal_dst(struct sk_buff *skb, struct inet_cork_full *cork) 1815 { 1816 struct dst_entry *dst = cork->base.dst; 1817 1818 cork->base.dst = NULL; 1819 cork->base.flags &= ~IPCORK_ALLFRAG; 1820 skb_dst_set(skb, dst); 1821 } 1822 1823 static void ip6_cork_release(struct inet_cork_full *cork, 1824 struct inet6_cork *v6_cork) 1825 { 1826 if (v6_cork->opt) { 1827 struct ipv6_txoptions *opt = v6_cork->opt; 1828 1829 kfree(opt->dst0opt); 1830 kfree(opt->dst1opt); 1831 kfree(opt->hopopt); 1832 kfree(opt->srcrt); 1833 kfree(opt); 1834 v6_cork->opt = NULL; 1835 } 1836 1837 if (cork->base.dst) { 1838 dst_release(cork->base.dst); 1839 cork->base.dst = NULL; 1840 cork->base.flags &= ~IPCORK_ALLFRAG; 1841 } 1842 } 1843 1844 struct sk_buff *__ip6_make_skb(struct sock *sk, 1845 struct sk_buff_head *queue, 1846 struct inet_cork_full *cork, 1847 struct inet6_cork *v6_cork) 1848 { 1849 struct sk_buff *skb, *tmp_skb; 1850 struct sk_buff **tail_skb; 1851 struct in6_addr *final_dst; 1852 struct ipv6_pinfo *np = inet6_sk(sk); 1853 struct net *net = sock_net(sk); 1854 struct ipv6hdr *hdr; 1855 struct ipv6_txoptions *opt = v6_cork->opt; 1856 struct rt6_info *rt = (struct rt6_info *)cork->base.dst; 1857 struct flowi6 *fl6 = &cork->fl.u.ip6; 1858 unsigned char proto = fl6->flowi6_proto; 1859 1860 skb = __skb_dequeue(queue); 1861 if (!skb) 1862 goto out; 1863 tail_skb = &(skb_shinfo(skb)->frag_list); 1864 1865 /* move skb->data to ip header from ext header */ 1866 if (skb->data < skb_network_header(skb)) 1867 __skb_pull(skb, skb_network_offset(skb)); 1868 while ((tmp_skb = __skb_dequeue(queue)) != NULL) { 1869 __skb_pull(tmp_skb, skb_network_header_len(skb)); 1870 *tail_skb = tmp_skb; 1871 tail_skb = &(tmp_skb->next); 1872 skb->len += tmp_skb->len; 1873 skb->data_len += tmp_skb->len; 1874 skb->truesize += tmp_skb->truesize; 1875 tmp_skb->destructor = NULL; 1876 tmp_skb->sk = NULL; 1877 } 1878 1879 /* Allow local fragmentation. */ 1880 skb->ignore_df = ip6_sk_ignore_df(sk); 1881 __skb_pull(skb, skb_network_header_len(skb)); 1882 1883 final_dst = &fl6->daddr; 1884 if (opt && opt->opt_flen) 1885 ipv6_push_frag_opts(skb, opt, &proto); 1886 if (opt && opt->opt_nflen) 1887 ipv6_push_nfrag_opts(skb, opt, &proto, &final_dst, &fl6->saddr); 1888 1889 skb_push(skb, sizeof(struct ipv6hdr)); 1890 skb_reset_network_header(skb); 1891 hdr = ipv6_hdr(skb); 1892 1893 ip6_flow_hdr(hdr, v6_cork->tclass, 1894 ip6_make_flowlabel(net, skb, fl6->flowlabel, 1895 ip6_autoflowlabel(net, np), fl6)); 1896 hdr->hop_limit = v6_cork->hop_limit; 1897 hdr->nexthdr = proto; 1898 hdr->saddr = fl6->saddr; 1899 hdr->daddr = *final_dst; 1900 1901 skb->priority = sk->sk_priority; 1902 skb->mark = cork->base.mark; 1903 skb->tstamp = cork->base.transmit_time; 1904 1905 ip6_cork_steal_dst(skb, cork); 1906 IP6_UPD_PO_STATS(net, rt->rt6i_idev, IPSTATS_MIB_OUT, skb->len); 1907 if (proto == IPPROTO_ICMPV6) { 1908 struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb)); 1909 1910 ICMP6MSGOUT_INC_STATS(net, idev, icmp6_hdr(skb)->icmp6_type); 1911 ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTMSGS); 1912 } 1913 1914 ip6_cork_release(cork, v6_cork); 1915 out: 1916 return skb; 1917 } 1918 1919 int ip6_send_skb(struct sk_buff *skb) 1920 { 1921 struct net *net = sock_net(skb->sk); 1922 struct rt6_info *rt = (struct rt6_info *)skb_dst(skb); 1923 int err; 1924 1925 err = ip6_local_out(net, skb->sk, skb); 1926 if (err) { 1927 if (err > 0) 1928 err = net_xmit_errno(err); 1929 if (err) 1930 IP6_INC_STATS(net, rt->rt6i_idev, 1931 IPSTATS_MIB_OUTDISCARDS); 1932 } 1933 1934 return err; 1935 } 1936 1937 int ip6_push_pending_frames(struct sock *sk) 1938 { 1939 struct sk_buff *skb; 1940 1941 skb = ip6_finish_skb(sk); 1942 if (!skb) 1943 return 0; 1944 1945 return ip6_send_skb(skb); 1946 } 1947 EXPORT_SYMBOL_GPL(ip6_push_pending_frames); 1948 1949 static void __ip6_flush_pending_frames(struct sock *sk, 1950 struct sk_buff_head *queue, 1951 struct inet_cork_full *cork, 1952 struct inet6_cork *v6_cork) 1953 { 1954 struct sk_buff *skb; 1955 1956 while ((skb = __skb_dequeue_tail(queue)) != NULL) { 1957 if (skb_dst(skb)) 1958 IP6_INC_STATS(sock_net(sk), ip6_dst_idev(skb_dst(skb)), 1959 IPSTATS_MIB_OUTDISCARDS); 1960 kfree_skb(skb); 1961 } 1962 1963 ip6_cork_release(cork, v6_cork); 1964 } 1965 1966 void ip6_flush_pending_frames(struct sock *sk) 1967 { 1968 __ip6_flush_pending_frames(sk, &sk->sk_write_queue, 1969 &inet_sk(sk)->cork, &inet6_sk(sk)->cork); 1970 } 1971 EXPORT_SYMBOL_GPL(ip6_flush_pending_frames); 1972 1973 struct sk_buff *ip6_make_skb(struct sock *sk, 1974 int getfrag(void *from, char *to, int offset, 1975 int len, int odd, struct sk_buff *skb), 1976 void *from, int length, int transhdrlen, 1977 struct ipcm6_cookie *ipc6, struct rt6_info *rt, 1978 unsigned int flags, struct inet_cork_full *cork) 1979 { 1980 struct inet6_cork v6_cork; 1981 struct sk_buff_head queue; 1982 int exthdrlen = (ipc6->opt ? ipc6->opt->opt_flen : 0); 1983 int err; 1984 1985 if (flags & MSG_PROBE) { 1986 dst_release(&rt->dst); 1987 return NULL; 1988 } 1989 1990 __skb_queue_head_init(&queue); 1991 1992 cork->base.flags = 0; 1993 cork->base.addr = 0; 1994 cork->base.opt = NULL; 1995 v6_cork.opt = NULL; 1996 err = ip6_setup_cork(sk, cork, &v6_cork, ipc6, rt); 1997 if (err) { 1998 ip6_cork_release(cork, &v6_cork); 1999 return ERR_PTR(err); 2000 } 2001 if (ipc6->dontfrag < 0) 2002 ipc6->dontfrag = inet6_sk(sk)->dontfrag; 2003 2004 err = __ip6_append_data(sk, &queue, cork, &v6_cork, 2005 ¤t->task_frag, getfrag, from, 2006 length + exthdrlen, transhdrlen + exthdrlen, 2007 flags, ipc6); 2008 if (err) { 2009 __ip6_flush_pending_frames(sk, &queue, cork, &v6_cork); 2010 return ERR_PTR(err); 2011 } 2012 2013 return __ip6_make_skb(sk, &queue, cork, &v6_cork); 2014 } 2015