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); 122 123 if (unlikely(IS_ERR_OR_NULL(neigh))) { 124 if (unlikely(!neigh)) 125 neigh = __neigh_create(&nd_tbl, nexthop, dev, false); 126 if (IS_ERR(neigh)) { 127 rcu_read_unlock_bh(); 128 IP6_INC_STATS(net, idev, IPSTATS_MIB_OUTNOROUTES); 129 kfree_skb_reason(skb, SKB_DROP_REASON_NEIGH_CREATEFAIL); 130 return -EINVAL; 131 } 132 } 133 sock_confirm_neigh(skb, neigh); 134 ret = neigh_output(neigh, skb, false); 135 rcu_read_unlock_bh(); 136 return ret; 137 } 138 139 static int 140 ip6_finish_output_gso_slowpath_drop(struct net *net, struct sock *sk, 141 struct sk_buff *skb, unsigned int mtu) 142 { 143 struct sk_buff *segs, *nskb; 144 netdev_features_t features; 145 int ret = 0; 146 147 /* Please see corresponding comment in ip_finish_output_gso 148 * describing the cases where GSO segment length exceeds the 149 * egress MTU. 150 */ 151 features = netif_skb_features(skb); 152 segs = skb_gso_segment(skb, features & ~NETIF_F_GSO_MASK); 153 if (IS_ERR_OR_NULL(segs)) { 154 kfree_skb(skb); 155 return -ENOMEM; 156 } 157 158 consume_skb(skb); 159 160 skb_list_walk_safe(segs, segs, nskb) { 161 int err; 162 163 skb_mark_not_on_list(segs); 164 err = ip6_fragment(net, sk, segs, ip6_finish_output2); 165 if (err && ret == 0) 166 ret = err; 167 } 168 169 return ret; 170 } 171 172 static int __ip6_finish_output(struct net *net, struct sock *sk, struct sk_buff *skb) 173 { 174 unsigned int mtu; 175 176 #if defined(CONFIG_NETFILTER) && defined(CONFIG_XFRM) 177 /* Policy lookup after SNAT yielded a new policy */ 178 if (skb_dst(skb)->xfrm) { 179 IP6CB(skb)->flags |= IP6SKB_REROUTED; 180 return dst_output(net, sk, skb); 181 } 182 #endif 183 184 mtu = ip6_skb_dst_mtu(skb); 185 if (skb_is_gso(skb) && 186 !(IP6CB(skb)->flags & IP6SKB_FAKEJUMBO) && 187 !skb_gso_validate_network_len(skb, mtu)) 188 return ip6_finish_output_gso_slowpath_drop(net, sk, skb, mtu); 189 190 if ((skb->len > mtu && !skb_is_gso(skb)) || 191 dst_allfrag(skb_dst(skb)) || 192 (IP6CB(skb)->frag_max_size && skb->len > IP6CB(skb)->frag_max_size)) 193 return ip6_fragment(net, sk, skb, ip6_finish_output2); 194 else 195 return ip6_finish_output2(net, sk, skb); 196 } 197 198 static int ip6_finish_output(struct net *net, struct sock *sk, struct sk_buff *skb) 199 { 200 int ret; 201 202 ret = BPF_CGROUP_RUN_PROG_INET_EGRESS(sk, skb); 203 switch (ret) { 204 case NET_XMIT_SUCCESS: 205 case NET_XMIT_CN: 206 return __ip6_finish_output(net, sk, skb) ? : ret; 207 default: 208 kfree_skb_reason(skb, SKB_DROP_REASON_BPF_CGROUP_EGRESS); 209 return ret; 210 } 211 } 212 213 int ip6_output(struct net *net, struct sock *sk, struct sk_buff *skb) 214 { 215 struct net_device *dev = skb_dst(skb)->dev, *indev = skb->dev; 216 struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb)); 217 218 skb->protocol = htons(ETH_P_IPV6); 219 skb->dev = dev; 220 221 if (unlikely(idev->cnf.disable_ipv6)) { 222 IP6_INC_STATS(net, idev, IPSTATS_MIB_OUTDISCARDS); 223 kfree_skb_reason(skb, SKB_DROP_REASON_IPV6DISABLED); 224 return 0; 225 } 226 227 return NF_HOOK_COND(NFPROTO_IPV6, NF_INET_POST_ROUTING, 228 net, sk, skb, indev, dev, 229 ip6_finish_output, 230 !(IP6CB(skb)->flags & IP6SKB_REROUTED)); 231 } 232 EXPORT_SYMBOL(ip6_output); 233 234 bool ip6_autoflowlabel(struct net *net, const struct ipv6_pinfo *np) 235 { 236 if (!np->autoflowlabel_set) 237 return ip6_default_np_autolabel(net); 238 else 239 return np->autoflowlabel; 240 } 241 242 /* 243 * xmit an sk_buff (used by TCP, SCTP and DCCP) 244 * Note : socket lock is not held for SYNACK packets, but might be modified 245 * by calls to skb_set_owner_w() and ipv6_local_error(), 246 * which are using proper atomic operations or spinlocks. 247 */ 248 int ip6_xmit(const struct sock *sk, struct sk_buff *skb, struct flowi6 *fl6, 249 __u32 mark, struct ipv6_txoptions *opt, int tclass, u32 priority) 250 { 251 struct net *net = sock_net(sk); 252 const struct ipv6_pinfo *np = inet6_sk(sk); 253 struct in6_addr *first_hop = &fl6->daddr; 254 struct dst_entry *dst = skb_dst(skb); 255 struct net_device *dev = dst->dev; 256 struct inet6_dev *idev = ip6_dst_idev(dst); 257 struct hop_jumbo_hdr *hop_jumbo; 258 int hoplen = sizeof(*hop_jumbo); 259 unsigned int head_room; 260 struct ipv6hdr *hdr; 261 u8 proto = fl6->flowi6_proto; 262 int seg_len = skb->len; 263 int hlimit = -1; 264 u32 mtu; 265 266 head_room = sizeof(struct ipv6hdr) + hoplen + LL_RESERVED_SPACE(dev); 267 if (opt) 268 head_room += opt->opt_nflen + opt->opt_flen; 269 270 if (unlikely(head_room > skb_headroom(skb))) { 271 skb = skb_expand_head(skb, head_room); 272 if (!skb) { 273 IP6_INC_STATS(net, idev, IPSTATS_MIB_OUTDISCARDS); 274 return -ENOBUFS; 275 } 276 } 277 278 if (opt) { 279 seg_len += opt->opt_nflen + opt->opt_flen; 280 281 if (opt->opt_flen) 282 ipv6_push_frag_opts(skb, opt, &proto); 283 284 if (opt->opt_nflen) 285 ipv6_push_nfrag_opts(skb, opt, &proto, &first_hop, 286 &fl6->saddr); 287 } 288 289 if (unlikely(seg_len > IPV6_MAXPLEN)) { 290 hop_jumbo = skb_push(skb, hoplen); 291 292 hop_jumbo->nexthdr = proto; 293 hop_jumbo->hdrlen = 0; 294 hop_jumbo->tlv_type = IPV6_TLV_JUMBO; 295 hop_jumbo->tlv_len = 4; 296 hop_jumbo->jumbo_payload_len = htonl(seg_len + hoplen); 297 298 proto = IPPROTO_HOPOPTS; 299 seg_len = 0; 300 IP6CB(skb)->flags |= IP6SKB_FAKEJUMBO; 301 } 302 303 skb_push(skb, sizeof(struct ipv6hdr)); 304 skb_reset_network_header(skb); 305 hdr = ipv6_hdr(skb); 306 307 /* 308 * Fill in the IPv6 header 309 */ 310 if (np) 311 hlimit = np->hop_limit; 312 if (hlimit < 0) 313 hlimit = ip6_dst_hoplimit(dst); 314 315 ip6_flow_hdr(hdr, tclass, ip6_make_flowlabel(net, skb, fl6->flowlabel, 316 ip6_autoflowlabel(net, np), fl6)); 317 318 hdr->payload_len = htons(seg_len); 319 hdr->nexthdr = proto; 320 hdr->hop_limit = hlimit; 321 322 hdr->saddr = fl6->saddr; 323 hdr->daddr = *first_hop; 324 325 skb->protocol = htons(ETH_P_IPV6); 326 skb->priority = priority; 327 skb->mark = mark; 328 329 mtu = dst_mtu(dst); 330 if ((skb->len <= mtu) || skb->ignore_df || skb_is_gso(skb)) { 331 IP6_UPD_PO_STATS(net, idev, IPSTATS_MIB_OUT, skb->len); 332 333 /* if egress device is enslaved to an L3 master device pass the 334 * skb to its handler for processing 335 */ 336 skb = l3mdev_ip6_out((struct sock *)sk, skb); 337 if (unlikely(!skb)) 338 return 0; 339 340 /* hooks should never assume socket lock is held. 341 * we promote our socket to non const 342 */ 343 return NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT, 344 net, (struct sock *)sk, skb, NULL, dev, 345 dst_output); 346 } 347 348 skb->dev = dev; 349 /* ipv6_local_error() does not require socket lock, 350 * we promote our socket to non const 351 */ 352 ipv6_local_error((struct sock *)sk, EMSGSIZE, fl6, mtu); 353 354 IP6_INC_STATS(net, idev, IPSTATS_MIB_FRAGFAILS); 355 kfree_skb(skb); 356 return -EMSGSIZE; 357 } 358 EXPORT_SYMBOL(ip6_xmit); 359 360 static int ip6_call_ra_chain(struct sk_buff *skb, int sel) 361 { 362 struct ip6_ra_chain *ra; 363 struct sock *last = NULL; 364 365 read_lock(&ip6_ra_lock); 366 for (ra = ip6_ra_chain; ra; ra = ra->next) { 367 struct sock *sk = ra->sk; 368 if (sk && ra->sel == sel && 369 (!sk->sk_bound_dev_if || 370 sk->sk_bound_dev_if == skb->dev->ifindex)) { 371 struct ipv6_pinfo *np = inet6_sk(sk); 372 373 if (np && np->rtalert_isolate && 374 !net_eq(sock_net(sk), dev_net(skb->dev))) { 375 continue; 376 } 377 if (last) { 378 struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC); 379 if (skb2) 380 rawv6_rcv(last, skb2); 381 } 382 last = sk; 383 } 384 } 385 386 if (last) { 387 rawv6_rcv(last, skb); 388 read_unlock(&ip6_ra_lock); 389 return 1; 390 } 391 read_unlock(&ip6_ra_lock); 392 return 0; 393 } 394 395 static int ip6_forward_proxy_check(struct sk_buff *skb) 396 { 397 struct ipv6hdr *hdr = ipv6_hdr(skb); 398 u8 nexthdr = hdr->nexthdr; 399 __be16 frag_off; 400 int offset; 401 402 if (ipv6_ext_hdr(nexthdr)) { 403 offset = ipv6_skip_exthdr(skb, sizeof(*hdr), &nexthdr, &frag_off); 404 if (offset < 0) 405 return 0; 406 } else 407 offset = sizeof(struct ipv6hdr); 408 409 if (nexthdr == IPPROTO_ICMPV6) { 410 struct icmp6hdr *icmp6; 411 412 if (!pskb_may_pull(skb, (skb_network_header(skb) + 413 offset + 1 - skb->data))) 414 return 0; 415 416 icmp6 = (struct icmp6hdr *)(skb_network_header(skb) + offset); 417 418 switch (icmp6->icmp6_type) { 419 case NDISC_ROUTER_SOLICITATION: 420 case NDISC_ROUTER_ADVERTISEMENT: 421 case NDISC_NEIGHBOUR_SOLICITATION: 422 case NDISC_NEIGHBOUR_ADVERTISEMENT: 423 case NDISC_REDIRECT: 424 /* For reaction involving unicast neighbor discovery 425 * message destined to the proxied address, pass it to 426 * input function. 427 */ 428 return 1; 429 default: 430 break; 431 } 432 } 433 434 /* 435 * The proxying router can't forward traffic sent to a link-local 436 * address, so signal the sender and discard the packet. This 437 * behavior is clarified by the MIPv6 specification. 438 */ 439 if (ipv6_addr_type(&hdr->daddr) & IPV6_ADDR_LINKLOCAL) { 440 dst_link_failure(skb); 441 return -1; 442 } 443 444 return 0; 445 } 446 447 static inline int ip6_forward_finish(struct net *net, struct sock *sk, 448 struct sk_buff *skb) 449 { 450 struct dst_entry *dst = skb_dst(skb); 451 452 __IP6_INC_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTFORWDATAGRAMS); 453 __IP6_ADD_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTOCTETS, skb->len); 454 455 #ifdef CONFIG_NET_SWITCHDEV 456 if (skb->offload_l3_fwd_mark) { 457 consume_skb(skb); 458 return 0; 459 } 460 #endif 461 462 skb_clear_tstamp(skb); 463 return dst_output(net, sk, skb); 464 } 465 466 static bool ip6_pkt_too_big(const struct sk_buff *skb, unsigned int mtu) 467 { 468 if (skb->len <= mtu) 469 return false; 470 471 /* ipv6 conntrack defrag sets max_frag_size + ignore_df */ 472 if (IP6CB(skb)->frag_max_size && IP6CB(skb)->frag_max_size > mtu) 473 return true; 474 475 if (skb->ignore_df) 476 return false; 477 478 if (skb_is_gso(skb) && skb_gso_validate_network_len(skb, mtu)) 479 return false; 480 481 return true; 482 } 483 484 int ip6_forward(struct sk_buff *skb) 485 { 486 struct dst_entry *dst = skb_dst(skb); 487 struct ipv6hdr *hdr = ipv6_hdr(skb); 488 struct inet6_skb_parm *opt = IP6CB(skb); 489 struct net *net = dev_net(dst->dev); 490 struct inet6_dev *idev; 491 SKB_DR(reason); 492 u32 mtu; 493 494 idev = __in6_dev_get_safely(dev_get_by_index_rcu(net, IP6CB(skb)->iif)); 495 if (net->ipv6.devconf_all->forwarding == 0) 496 goto error; 497 498 if (skb->pkt_type != PACKET_HOST) 499 goto drop; 500 501 if (unlikely(skb->sk)) 502 goto drop; 503 504 if (skb_warn_if_lro(skb)) 505 goto drop; 506 507 if (!net->ipv6.devconf_all->disable_policy && 508 (!idev || !idev->cnf.disable_policy) && 509 !xfrm6_policy_check(NULL, XFRM_POLICY_FWD, skb)) { 510 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INDISCARDS); 511 goto drop; 512 } 513 514 skb_forward_csum(skb); 515 516 /* 517 * We DO NOT make any processing on 518 * RA packets, pushing them to user level AS IS 519 * without ane WARRANTY that application will be able 520 * to interpret them. The reason is that we 521 * cannot make anything clever here. 522 * 523 * We are not end-node, so that if packet contains 524 * AH/ESP, we cannot make anything. 525 * Defragmentation also would be mistake, RA packets 526 * cannot be fragmented, because there is no warranty 527 * that different fragments will go along one path. --ANK 528 */ 529 if (unlikely(opt->flags & IP6SKB_ROUTERALERT)) { 530 if (ip6_call_ra_chain(skb, ntohs(opt->ra))) 531 return 0; 532 } 533 534 /* 535 * check and decrement ttl 536 */ 537 if (hdr->hop_limit <= 1) { 538 icmpv6_send(skb, ICMPV6_TIME_EXCEED, ICMPV6_EXC_HOPLIMIT, 0); 539 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); 540 541 kfree_skb_reason(skb, SKB_DROP_REASON_IP_INHDR); 542 return -ETIMEDOUT; 543 } 544 545 /* XXX: idev->cnf.proxy_ndp? */ 546 if (net->ipv6.devconf_all->proxy_ndp && 547 pneigh_lookup(&nd_tbl, net, &hdr->daddr, skb->dev, 0)) { 548 int proxied = ip6_forward_proxy_check(skb); 549 if (proxied > 0) { 550 /* It's tempting to decrease the hop limit 551 * here by 1, as we do at the end of the 552 * function too. 553 * 554 * But that would be incorrect, as proxying is 555 * not forwarding. The ip6_input function 556 * will handle this packet locally, and it 557 * depends on the hop limit being unchanged. 558 * 559 * One example is the NDP hop limit, that 560 * always has to stay 255, but other would be 561 * similar checks around RA packets, where the 562 * user can even change the desired limit. 563 */ 564 return ip6_input(skb); 565 } else if (proxied < 0) { 566 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INDISCARDS); 567 goto drop; 568 } 569 } 570 571 if (!xfrm6_route_forward(skb)) { 572 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INDISCARDS); 573 SKB_DR_SET(reason, XFRM_POLICY); 574 goto drop; 575 } 576 dst = skb_dst(skb); 577 578 /* IPv6 specs say nothing about it, but it is clear that we cannot 579 send redirects to source routed frames. 580 We don't send redirects to frames decapsulated from IPsec. 581 */ 582 if (IP6CB(skb)->iif == dst->dev->ifindex && 583 opt->srcrt == 0 && !skb_sec_path(skb)) { 584 struct in6_addr *target = NULL; 585 struct inet_peer *peer; 586 struct rt6_info *rt; 587 588 /* 589 * incoming and outgoing devices are the same 590 * send a redirect. 591 */ 592 593 rt = (struct rt6_info *) dst; 594 if (rt->rt6i_flags & RTF_GATEWAY) 595 target = &rt->rt6i_gateway; 596 else 597 target = &hdr->daddr; 598 599 peer = inet_getpeer_v6(net->ipv6.peers, &hdr->daddr, 1); 600 601 /* Limit redirects both by destination (here) 602 and by source (inside ndisc_send_redirect) 603 */ 604 if (inet_peer_xrlim_allow(peer, 1*HZ)) 605 ndisc_send_redirect(skb, target); 606 if (peer) 607 inet_putpeer(peer); 608 } else { 609 int addrtype = ipv6_addr_type(&hdr->saddr); 610 611 /* This check is security critical. */ 612 if (addrtype == IPV6_ADDR_ANY || 613 addrtype & (IPV6_ADDR_MULTICAST | IPV6_ADDR_LOOPBACK)) 614 goto error; 615 if (addrtype & IPV6_ADDR_LINKLOCAL) { 616 icmpv6_send(skb, ICMPV6_DEST_UNREACH, 617 ICMPV6_NOT_NEIGHBOUR, 0); 618 goto error; 619 } 620 } 621 622 mtu = ip6_dst_mtu_maybe_forward(dst, true); 623 if (mtu < IPV6_MIN_MTU) 624 mtu = IPV6_MIN_MTU; 625 626 if (ip6_pkt_too_big(skb, mtu)) { 627 /* Again, force OUTPUT device used as source address */ 628 skb->dev = dst->dev; 629 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu); 630 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INTOOBIGERRORS); 631 __IP6_INC_STATS(net, ip6_dst_idev(dst), 632 IPSTATS_MIB_FRAGFAILS); 633 kfree_skb_reason(skb, SKB_DROP_REASON_PKT_TOO_BIG); 634 return -EMSGSIZE; 635 } 636 637 if (skb_cow(skb, dst->dev->hard_header_len)) { 638 __IP6_INC_STATS(net, ip6_dst_idev(dst), 639 IPSTATS_MIB_OUTDISCARDS); 640 goto drop; 641 } 642 643 hdr = ipv6_hdr(skb); 644 645 /* Mangling hops number delayed to point after skb COW */ 646 647 hdr->hop_limit--; 648 649 return NF_HOOK(NFPROTO_IPV6, NF_INET_FORWARD, 650 net, NULL, skb, skb->dev, dst->dev, 651 ip6_forward_finish); 652 653 error: 654 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INADDRERRORS); 655 SKB_DR_SET(reason, IP_INADDRERRORS); 656 drop: 657 kfree_skb_reason(skb, reason); 658 return -EINVAL; 659 } 660 661 static void ip6_copy_metadata(struct sk_buff *to, struct sk_buff *from) 662 { 663 to->pkt_type = from->pkt_type; 664 to->priority = from->priority; 665 to->protocol = from->protocol; 666 skb_dst_drop(to); 667 skb_dst_set(to, dst_clone(skb_dst(from))); 668 to->dev = from->dev; 669 to->mark = from->mark; 670 671 skb_copy_hash(to, from); 672 673 #ifdef CONFIG_NET_SCHED 674 to->tc_index = from->tc_index; 675 #endif 676 nf_copy(to, from); 677 skb_ext_copy(to, from); 678 skb_copy_secmark(to, from); 679 } 680 681 int ip6_fraglist_init(struct sk_buff *skb, unsigned int hlen, u8 *prevhdr, 682 u8 nexthdr, __be32 frag_id, 683 struct ip6_fraglist_iter *iter) 684 { 685 unsigned int first_len; 686 struct frag_hdr *fh; 687 688 /* BUILD HEADER */ 689 *prevhdr = NEXTHDR_FRAGMENT; 690 iter->tmp_hdr = kmemdup(skb_network_header(skb), hlen, GFP_ATOMIC); 691 if (!iter->tmp_hdr) 692 return -ENOMEM; 693 694 iter->frag = skb_shinfo(skb)->frag_list; 695 skb_frag_list_init(skb); 696 697 iter->offset = 0; 698 iter->hlen = hlen; 699 iter->frag_id = frag_id; 700 iter->nexthdr = nexthdr; 701 702 __skb_pull(skb, hlen); 703 fh = __skb_push(skb, sizeof(struct frag_hdr)); 704 __skb_push(skb, hlen); 705 skb_reset_network_header(skb); 706 memcpy(skb_network_header(skb), iter->tmp_hdr, hlen); 707 708 fh->nexthdr = nexthdr; 709 fh->reserved = 0; 710 fh->frag_off = htons(IP6_MF); 711 fh->identification = frag_id; 712 713 first_len = skb_pagelen(skb); 714 skb->data_len = first_len - skb_headlen(skb); 715 skb->len = first_len; 716 ipv6_hdr(skb)->payload_len = htons(first_len - sizeof(struct ipv6hdr)); 717 718 return 0; 719 } 720 EXPORT_SYMBOL(ip6_fraglist_init); 721 722 void ip6_fraglist_prepare(struct sk_buff *skb, 723 struct ip6_fraglist_iter *iter) 724 { 725 struct sk_buff *frag = iter->frag; 726 unsigned int hlen = iter->hlen; 727 struct frag_hdr *fh; 728 729 frag->ip_summed = CHECKSUM_NONE; 730 skb_reset_transport_header(frag); 731 fh = __skb_push(frag, sizeof(struct frag_hdr)); 732 __skb_push(frag, hlen); 733 skb_reset_network_header(frag); 734 memcpy(skb_network_header(frag), iter->tmp_hdr, hlen); 735 iter->offset += skb->len - hlen - sizeof(struct frag_hdr); 736 fh->nexthdr = iter->nexthdr; 737 fh->reserved = 0; 738 fh->frag_off = htons(iter->offset); 739 if (frag->next) 740 fh->frag_off |= htons(IP6_MF); 741 fh->identification = iter->frag_id; 742 ipv6_hdr(frag)->payload_len = htons(frag->len - sizeof(struct ipv6hdr)); 743 ip6_copy_metadata(frag, skb); 744 } 745 EXPORT_SYMBOL(ip6_fraglist_prepare); 746 747 void ip6_frag_init(struct sk_buff *skb, unsigned int hlen, unsigned int mtu, 748 unsigned short needed_tailroom, int hdr_room, u8 *prevhdr, 749 u8 nexthdr, __be32 frag_id, struct ip6_frag_state *state) 750 { 751 state->prevhdr = prevhdr; 752 state->nexthdr = nexthdr; 753 state->frag_id = frag_id; 754 755 state->hlen = hlen; 756 state->mtu = mtu; 757 758 state->left = skb->len - hlen; /* Space per frame */ 759 state->ptr = hlen; /* Where to start from */ 760 761 state->hroom = hdr_room; 762 state->troom = needed_tailroom; 763 764 state->offset = 0; 765 } 766 EXPORT_SYMBOL(ip6_frag_init); 767 768 struct sk_buff *ip6_frag_next(struct sk_buff *skb, struct ip6_frag_state *state) 769 { 770 u8 *prevhdr = state->prevhdr, *fragnexthdr_offset; 771 struct sk_buff *frag; 772 struct frag_hdr *fh; 773 unsigned int len; 774 775 len = state->left; 776 /* IF: it doesn't fit, use 'mtu' - the data space left */ 777 if (len > state->mtu) 778 len = state->mtu; 779 /* IF: we are not sending up to and including the packet end 780 then align the next start on an eight byte boundary */ 781 if (len < state->left) 782 len &= ~7; 783 784 /* Allocate buffer */ 785 frag = alloc_skb(len + state->hlen + sizeof(struct frag_hdr) + 786 state->hroom + state->troom, GFP_ATOMIC); 787 if (!frag) 788 return ERR_PTR(-ENOMEM); 789 790 /* 791 * Set up data on packet 792 */ 793 794 ip6_copy_metadata(frag, skb); 795 skb_reserve(frag, state->hroom); 796 skb_put(frag, len + state->hlen + sizeof(struct frag_hdr)); 797 skb_reset_network_header(frag); 798 fh = (struct frag_hdr *)(skb_network_header(frag) + state->hlen); 799 frag->transport_header = (frag->network_header + state->hlen + 800 sizeof(struct frag_hdr)); 801 802 /* 803 * Charge the memory for the fragment to any owner 804 * it might possess 805 */ 806 if (skb->sk) 807 skb_set_owner_w(frag, skb->sk); 808 809 /* 810 * Copy the packet header into the new buffer. 811 */ 812 skb_copy_from_linear_data(skb, skb_network_header(frag), state->hlen); 813 814 fragnexthdr_offset = skb_network_header(frag); 815 fragnexthdr_offset += prevhdr - skb_network_header(skb); 816 *fragnexthdr_offset = NEXTHDR_FRAGMENT; 817 818 /* 819 * Build fragment header. 820 */ 821 fh->nexthdr = state->nexthdr; 822 fh->reserved = 0; 823 fh->identification = state->frag_id; 824 825 /* 826 * Copy a block of the IP datagram. 827 */ 828 BUG_ON(skb_copy_bits(skb, state->ptr, skb_transport_header(frag), 829 len)); 830 state->left -= len; 831 832 fh->frag_off = htons(state->offset); 833 if (state->left > 0) 834 fh->frag_off |= htons(IP6_MF); 835 ipv6_hdr(frag)->payload_len = htons(frag->len - sizeof(struct ipv6hdr)); 836 837 state->ptr += len; 838 state->offset += len; 839 840 return frag; 841 } 842 EXPORT_SYMBOL(ip6_frag_next); 843 844 int ip6_fragment(struct net *net, struct sock *sk, struct sk_buff *skb, 845 int (*output)(struct net *, struct sock *, struct sk_buff *)) 846 { 847 struct sk_buff *frag; 848 struct rt6_info *rt = (struct rt6_info *)skb_dst(skb); 849 struct ipv6_pinfo *np = skb->sk && !dev_recursion_level() ? 850 inet6_sk(skb->sk) : NULL; 851 bool mono_delivery_time = skb->mono_delivery_time; 852 struct ip6_frag_state state; 853 unsigned int mtu, hlen, nexthdr_offset; 854 ktime_t tstamp = skb->tstamp; 855 int hroom, err = 0; 856 __be32 frag_id; 857 u8 *prevhdr, nexthdr = 0; 858 859 err = ip6_find_1stfragopt(skb, &prevhdr); 860 if (err < 0) 861 goto fail; 862 hlen = err; 863 nexthdr = *prevhdr; 864 nexthdr_offset = prevhdr - skb_network_header(skb); 865 866 mtu = ip6_skb_dst_mtu(skb); 867 868 /* We must not fragment if the socket is set to force MTU discovery 869 * or if the skb it not generated by a local socket. 870 */ 871 if (unlikely(!skb->ignore_df && skb->len > mtu)) 872 goto fail_toobig; 873 874 if (IP6CB(skb)->frag_max_size) { 875 if (IP6CB(skb)->frag_max_size > mtu) 876 goto fail_toobig; 877 878 /* don't send fragments larger than what we received */ 879 mtu = IP6CB(skb)->frag_max_size; 880 if (mtu < IPV6_MIN_MTU) 881 mtu = IPV6_MIN_MTU; 882 } 883 884 if (np && np->frag_size < mtu) { 885 if (np->frag_size) 886 mtu = np->frag_size; 887 } 888 if (mtu < hlen + sizeof(struct frag_hdr) + 8) 889 goto fail_toobig; 890 mtu -= hlen + sizeof(struct frag_hdr); 891 892 frag_id = ipv6_select_ident(net, &ipv6_hdr(skb)->daddr, 893 &ipv6_hdr(skb)->saddr); 894 895 if (skb->ip_summed == CHECKSUM_PARTIAL && 896 (err = skb_checksum_help(skb))) 897 goto fail; 898 899 prevhdr = skb_network_header(skb) + nexthdr_offset; 900 hroom = LL_RESERVED_SPACE(rt->dst.dev); 901 if (skb_has_frag_list(skb)) { 902 unsigned int first_len = skb_pagelen(skb); 903 struct ip6_fraglist_iter iter; 904 struct sk_buff *frag2; 905 906 if (first_len - hlen > mtu || 907 ((first_len - hlen) & 7) || 908 skb_cloned(skb) || 909 skb_headroom(skb) < (hroom + sizeof(struct frag_hdr))) 910 goto slow_path; 911 912 skb_walk_frags(skb, frag) { 913 /* Correct geometry. */ 914 if (frag->len > mtu || 915 ((frag->len & 7) && frag->next) || 916 skb_headroom(frag) < (hlen + hroom + sizeof(struct frag_hdr))) 917 goto slow_path_clean; 918 919 /* Partially cloned skb? */ 920 if (skb_shared(frag)) 921 goto slow_path_clean; 922 923 BUG_ON(frag->sk); 924 if (skb->sk) { 925 frag->sk = skb->sk; 926 frag->destructor = sock_wfree; 927 } 928 skb->truesize -= frag->truesize; 929 } 930 931 err = ip6_fraglist_init(skb, hlen, prevhdr, nexthdr, frag_id, 932 &iter); 933 if (err < 0) 934 goto fail; 935 936 /* We prevent @rt from being freed. */ 937 rcu_read_lock(); 938 939 for (;;) { 940 /* Prepare header of the next frame, 941 * before previous one went down. */ 942 if (iter.frag) 943 ip6_fraglist_prepare(skb, &iter); 944 945 skb_set_delivery_time(skb, tstamp, mono_delivery_time); 946 err = output(net, sk, skb); 947 if (!err) 948 IP6_INC_STATS(net, ip6_dst_idev(&rt->dst), 949 IPSTATS_MIB_FRAGCREATES); 950 951 if (err || !iter.frag) 952 break; 953 954 skb = ip6_fraglist_next(&iter); 955 } 956 957 kfree(iter.tmp_hdr); 958 959 if (err == 0) { 960 IP6_INC_STATS(net, ip6_dst_idev(&rt->dst), 961 IPSTATS_MIB_FRAGOKS); 962 rcu_read_unlock(); 963 return 0; 964 } 965 966 kfree_skb_list(iter.frag); 967 968 IP6_INC_STATS(net, ip6_dst_idev(&rt->dst), 969 IPSTATS_MIB_FRAGFAILS); 970 rcu_read_unlock(); 971 return err; 972 973 slow_path_clean: 974 skb_walk_frags(skb, frag2) { 975 if (frag2 == frag) 976 break; 977 frag2->sk = NULL; 978 frag2->destructor = NULL; 979 skb->truesize += frag2->truesize; 980 } 981 } 982 983 slow_path: 984 /* 985 * Fragment the datagram. 986 */ 987 988 ip6_frag_init(skb, hlen, mtu, rt->dst.dev->needed_tailroom, 989 LL_RESERVED_SPACE(rt->dst.dev), prevhdr, nexthdr, frag_id, 990 &state); 991 992 /* 993 * Keep copying data until we run out. 994 */ 995 996 while (state.left > 0) { 997 frag = ip6_frag_next(skb, &state); 998 if (IS_ERR(frag)) { 999 err = PTR_ERR(frag); 1000 goto fail; 1001 } 1002 1003 /* 1004 * Put this fragment into the sending queue. 1005 */ 1006 skb_set_delivery_time(frag, tstamp, mono_delivery_time); 1007 err = output(net, sk, frag); 1008 if (err) 1009 goto fail; 1010 1011 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), 1012 IPSTATS_MIB_FRAGCREATES); 1013 } 1014 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), 1015 IPSTATS_MIB_FRAGOKS); 1016 consume_skb(skb); 1017 return err; 1018 1019 fail_toobig: 1020 if (skb->sk && dst_allfrag(skb_dst(skb))) 1021 sk_gso_disable(skb->sk); 1022 1023 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu); 1024 err = -EMSGSIZE; 1025 1026 fail: 1027 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), 1028 IPSTATS_MIB_FRAGFAILS); 1029 kfree_skb(skb); 1030 return err; 1031 } 1032 1033 static inline int ip6_rt_check(const struct rt6key *rt_key, 1034 const struct in6_addr *fl_addr, 1035 const struct in6_addr *addr_cache) 1036 { 1037 return (rt_key->plen != 128 || !ipv6_addr_equal(fl_addr, &rt_key->addr)) && 1038 (!addr_cache || !ipv6_addr_equal(fl_addr, addr_cache)); 1039 } 1040 1041 static struct dst_entry *ip6_sk_dst_check(struct sock *sk, 1042 struct dst_entry *dst, 1043 const struct flowi6 *fl6) 1044 { 1045 struct ipv6_pinfo *np = inet6_sk(sk); 1046 struct rt6_info *rt; 1047 1048 if (!dst) 1049 goto out; 1050 1051 if (dst->ops->family != AF_INET6) { 1052 dst_release(dst); 1053 return NULL; 1054 } 1055 1056 rt = (struct rt6_info *)dst; 1057 /* Yes, checking route validity in not connected 1058 * case is not very simple. Take into account, 1059 * that we do not support routing by source, TOS, 1060 * and MSG_DONTROUTE --ANK (980726) 1061 * 1062 * 1. ip6_rt_check(): If route was host route, 1063 * check that cached destination is current. 1064 * If it is network route, we still may 1065 * check its validity using saved pointer 1066 * to the last used address: daddr_cache. 1067 * We do not want to save whole address now, 1068 * (because main consumer of this service 1069 * is tcp, which has not this problem), 1070 * so that the last trick works only on connected 1071 * sockets. 1072 * 2. oif also should be the same. 1073 */ 1074 if (ip6_rt_check(&rt->rt6i_dst, &fl6->daddr, np->daddr_cache) || 1075 #ifdef CONFIG_IPV6_SUBTREES 1076 ip6_rt_check(&rt->rt6i_src, &fl6->saddr, np->saddr_cache) || 1077 #endif 1078 (fl6->flowi6_oif && fl6->flowi6_oif != dst->dev->ifindex)) { 1079 dst_release(dst); 1080 dst = NULL; 1081 } 1082 1083 out: 1084 return dst; 1085 } 1086 1087 static int ip6_dst_lookup_tail(struct net *net, const struct sock *sk, 1088 struct dst_entry **dst, struct flowi6 *fl6) 1089 { 1090 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD 1091 struct neighbour *n; 1092 struct rt6_info *rt; 1093 #endif 1094 int err; 1095 int flags = 0; 1096 1097 /* The correct way to handle this would be to do 1098 * ip6_route_get_saddr, and then ip6_route_output; however, 1099 * the route-specific preferred source forces the 1100 * ip6_route_output call _before_ ip6_route_get_saddr. 1101 * 1102 * In source specific routing (no src=any default route), 1103 * ip6_route_output will fail given src=any saddr, though, so 1104 * that's why we try it again later. 1105 */ 1106 if (ipv6_addr_any(&fl6->saddr)) { 1107 struct fib6_info *from; 1108 struct rt6_info *rt; 1109 1110 *dst = ip6_route_output(net, sk, fl6); 1111 rt = (*dst)->error ? NULL : (struct rt6_info *)*dst; 1112 1113 rcu_read_lock(); 1114 from = rt ? rcu_dereference(rt->from) : NULL; 1115 err = ip6_route_get_saddr(net, from, &fl6->daddr, 1116 sk ? inet6_sk(sk)->srcprefs : 0, 1117 &fl6->saddr); 1118 rcu_read_unlock(); 1119 1120 if (err) 1121 goto out_err_release; 1122 1123 /* If we had an erroneous initial result, pretend it 1124 * never existed and let the SA-enabled version take 1125 * over. 1126 */ 1127 if ((*dst)->error) { 1128 dst_release(*dst); 1129 *dst = NULL; 1130 } 1131 1132 if (fl6->flowi6_oif) 1133 flags |= RT6_LOOKUP_F_IFACE; 1134 } 1135 1136 if (!*dst) 1137 *dst = ip6_route_output_flags(net, sk, fl6, flags); 1138 1139 err = (*dst)->error; 1140 if (err) 1141 goto out_err_release; 1142 1143 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD 1144 /* 1145 * Here if the dst entry we've looked up 1146 * has a neighbour entry that is in the INCOMPLETE 1147 * state and the src address from the flow is 1148 * marked as OPTIMISTIC, we release the found 1149 * dst entry and replace it instead with the 1150 * dst entry of the nexthop router 1151 */ 1152 rt = (struct rt6_info *) *dst; 1153 rcu_read_lock_bh(); 1154 n = __ipv6_neigh_lookup_noref(rt->dst.dev, 1155 rt6_nexthop(rt, &fl6->daddr)); 1156 err = n && !(n->nud_state & NUD_VALID) ? -EINVAL : 0; 1157 rcu_read_unlock_bh(); 1158 1159 if (err) { 1160 struct inet6_ifaddr *ifp; 1161 struct flowi6 fl_gw6; 1162 int redirect; 1163 1164 ifp = ipv6_get_ifaddr(net, &fl6->saddr, 1165 (*dst)->dev, 1); 1166 1167 redirect = (ifp && ifp->flags & IFA_F_OPTIMISTIC); 1168 if (ifp) 1169 in6_ifa_put(ifp); 1170 1171 if (redirect) { 1172 /* 1173 * We need to get the dst entry for the 1174 * default router instead 1175 */ 1176 dst_release(*dst); 1177 memcpy(&fl_gw6, fl6, sizeof(struct flowi6)); 1178 memset(&fl_gw6.daddr, 0, sizeof(struct in6_addr)); 1179 *dst = ip6_route_output(net, sk, &fl_gw6); 1180 err = (*dst)->error; 1181 if (err) 1182 goto out_err_release; 1183 } 1184 } 1185 #endif 1186 if (ipv6_addr_v4mapped(&fl6->saddr) && 1187 !(ipv6_addr_v4mapped(&fl6->daddr) || ipv6_addr_any(&fl6->daddr))) { 1188 err = -EAFNOSUPPORT; 1189 goto out_err_release; 1190 } 1191 1192 return 0; 1193 1194 out_err_release: 1195 dst_release(*dst); 1196 *dst = NULL; 1197 1198 if (err == -ENETUNREACH) 1199 IP6_INC_STATS(net, NULL, IPSTATS_MIB_OUTNOROUTES); 1200 return err; 1201 } 1202 1203 /** 1204 * ip6_dst_lookup - perform route lookup on flow 1205 * @net: Network namespace to perform lookup in 1206 * @sk: socket which provides route info 1207 * @dst: pointer to dst_entry * for result 1208 * @fl6: flow to lookup 1209 * 1210 * This function performs a route lookup on the given flow. 1211 * 1212 * It returns zero on success, or a standard errno code on error. 1213 */ 1214 int ip6_dst_lookup(struct net *net, struct sock *sk, struct dst_entry **dst, 1215 struct flowi6 *fl6) 1216 { 1217 *dst = NULL; 1218 return ip6_dst_lookup_tail(net, sk, dst, fl6); 1219 } 1220 EXPORT_SYMBOL_GPL(ip6_dst_lookup); 1221 1222 /** 1223 * ip6_dst_lookup_flow - perform route lookup on flow with ipsec 1224 * @net: Network namespace to perform lookup in 1225 * @sk: socket which provides route info 1226 * @fl6: flow to lookup 1227 * @final_dst: final destination address for ipsec lookup 1228 * 1229 * This function performs a route lookup on the given flow. 1230 * 1231 * It returns a valid dst pointer on success, or a pointer encoded 1232 * error code. 1233 */ 1234 struct dst_entry *ip6_dst_lookup_flow(struct net *net, const struct sock *sk, struct flowi6 *fl6, 1235 const struct in6_addr *final_dst) 1236 { 1237 struct dst_entry *dst = NULL; 1238 int err; 1239 1240 err = ip6_dst_lookup_tail(net, sk, &dst, fl6); 1241 if (err) 1242 return ERR_PTR(err); 1243 if (final_dst) 1244 fl6->daddr = *final_dst; 1245 1246 return xfrm_lookup_route(net, dst, flowi6_to_flowi(fl6), sk, 0); 1247 } 1248 EXPORT_SYMBOL_GPL(ip6_dst_lookup_flow); 1249 1250 /** 1251 * ip6_sk_dst_lookup_flow - perform socket cached route lookup on flow 1252 * @sk: socket which provides the dst cache and route info 1253 * @fl6: flow to lookup 1254 * @final_dst: final destination address for ipsec lookup 1255 * @connected: whether @sk is connected or not 1256 * 1257 * This function performs a route lookup on the given flow with the 1258 * possibility of using the cached route in the socket if it is valid. 1259 * It will take the socket dst lock when operating on the dst cache. 1260 * As a result, this function can only be used in process context. 1261 * 1262 * In addition, for a connected socket, cache the dst in the socket 1263 * if the current cache is not valid. 1264 * 1265 * It returns a valid dst pointer on success, or a pointer encoded 1266 * error code. 1267 */ 1268 struct dst_entry *ip6_sk_dst_lookup_flow(struct sock *sk, struct flowi6 *fl6, 1269 const struct in6_addr *final_dst, 1270 bool connected) 1271 { 1272 struct dst_entry *dst = sk_dst_check(sk, inet6_sk(sk)->dst_cookie); 1273 1274 dst = ip6_sk_dst_check(sk, dst, fl6); 1275 if (dst) 1276 return dst; 1277 1278 dst = ip6_dst_lookup_flow(sock_net(sk), sk, fl6, final_dst); 1279 if (connected && !IS_ERR(dst)) 1280 ip6_sk_dst_store_flow(sk, dst_clone(dst), fl6); 1281 1282 return dst; 1283 } 1284 EXPORT_SYMBOL_GPL(ip6_sk_dst_lookup_flow); 1285 1286 /** 1287 * ip6_dst_lookup_tunnel - perform route lookup on tunnel 1288 * @skb: Packet for which lookup is done 1289 * @dev: Tunnel device 1290 * @net: Network namespace of tunnel device 1291 * @sock: Socket which provides route info 1292 * @saddr: Memory to store the src ip address 1293 * @info: Tunnel information 1294 * @protocol: IP protocol 1295 * @use_cache: Flag to enable cache usage 1296 * This function performs a route lookup on a tunnel 1297 * 1298 * It returns a valid dst pointer and stores src address to be used in 1299 * tunnel in param saddr on success, else a pointer encoded error code. 1300 */ 1301 1302 struct dst_entry *ip6_dst_lookup_tunnel(struct sk_buff *skb, 1303 struct net_device *dev, 1304 struct net *net, 1305 struct socket *sock, 1306 struct in6_addr *saddr, 1307 const struct ip_tunnel_info *info, 1308 u8 protocol, 1309 bool use_cache) 1310 { 1311 struct dst_entry *dst = NULL; 1312 #ifdef CONFIG_DST_CACHE 1313 struct dst_cache *dst_cache; 1314 #endif 1315 struct flowi6 fl6; 1316 __u8 prio; 1317 1318 #ifdef CONFIG_DST_CACHE 1319 dst_cache = (struct dst_cache *)&info->dst_cache; 1320 if (use_cache) { 1321 dst = dst_cache_get_ip6(dst_cache, saddr); 1322 if (dst) 1323 return dst; 1324 } 1325 #endif 1326 memset(&fl6, 0, sizeof(fl6)); 1327 fl6.flowi6_mark = skb->mark; 1328 fl6.flowi6_proto = protocol; 1329 fl6.daddr = info->key.u.ipv6.dst; 1330 fl6.saddr = info->key.u.ipv6.src; 1331 prio = info->key.tos; 1332 fl6.flowlabel = ip6_make_flowinfo(prio, info->key.label); 1333 1334 dst = ipv6_stub->ipv6_dst_lookup_flow(net, sock->sk, &fl6, 1335 NULL); 1336 if (IS_ERR(dst)) { 1337 netdev_dbg(dev, "no route to %pI6\n", &fl6.daddr); 1338 return ERR_PTR(-ENETUNREACH); 1339 } 1340 if (dst->dev == dev) { /* is this necessary? */ 1341 netdev_dbg(dev, "circular route to %pI6\n", &fl6.daddr); 1342 dst_release(dst); 1343 return ERR_PTR(-ELOOP); 1344 } 1345 #ifdef CONFIG_DST_CACHE 1346 if (use_cache) 1347 dst_cache_set_ip6(dst_cache, dst, &fl6.saddr); 1348 #endif 1349 *saddr = fl6.saddr; 1350 return dst; 1351 } 1352 EXPORT_SYMBOL_GPL(ip6_dst_lookup_tunnel); 1353 1354 static inline struct ipv6_opt_hdr *ip6_opt_dup(struct ipv6_opt_hdr *src, 1355 gfp_t gfp) 1356 { 1357 return src ? kmemdup(src, (src->hdrlen + 1) * 8, gfp) : NULL; 1358 } 1359 1360 static inline struct ipv6_rt_hdr *ip6_rthdr_dup(struct ipv6_rt_hdr *src, 1361 gfp_t gfp) 1362 { 1363 return src ? kmemdup(src, (src->hdrlen + 1) * 8, gfp) : NULL; 1364 } 1365 1366 static void ip6_append_data_mtu(unsigned int *mtu, 1367 int *maxfraglen, 1368 unsigned int fragheaderlen, 1369 struct sk_buff *skb, 1370 struct rt6_info *rt, 1371 unsigned int orig_mtu) 1372 { 1373 if (!(rt->dst.flags & DST_XFRM_TUNNEL)) { 1374 if (!skb) { 1375 /* first fragment, reserve header_len */ 1376 *mtu = orig_mtu - rt->dst.header_len; 1377 1378 } else { 1379 /* 1380 * this fragment is not first, the headers 1381 * space is regarded as data space. 1382 */ 1383 *mtu = orig_mtu; 1384 } 1385 *maxfraglen = ((*mtu - fragheaderlen) & ~7) 1386 + fragheaderlen - sizeof(struct frag_hdr); 1387 } 1388 } 1389 1390 static int ip6_setup_cork(struct sock *sk, struct inet_cork_full *cork, 1391 struct inet6_cork *v6_cork, struct ipcm6_cookie *ipc6, 1392 struct rt6_info *rt) 1393 { 1394 struct ipv6_pinfo *np = inet6_sk(sk); 1395 unsigned int mtu; 1396 struct ipv6_txoptions *nopt, *opt = ipc6->opt; 1397 1398 /* callers pass dst together with a reference, set it first so 1399 * ip6_cork_release() can put it down even in case of an error. 1400 */ 1401 cork->base.dst = &rt->dst; 1402 1403 /* 1404 * setup for corking 1405 */ 1406 if (opt) { 1407 if (WARN_ON(v6_cork->opt)) 1408 return -EINVAL; 1409 1410 nopt = v6_cork->opt = kzalloc(sizeof(*opt), sk->sk_allocation); 1411 if (unlikely(!nopt)) 1412 return -ENOBUFS; 1413 1414 nopt->tot_len = sizeof(*opt); 1415 nopt->opt_flen = opt->opt_flen; 1416 nopt->opt_nflen = opt->opt_nflen; 1417 1418 nopt->dst0opt = ip6_opt_dup(opt->dst0opt, sk->sk_allocation); 1419 if (opt->dst0opt && !nopt->dst0opt) 1420 return -ENOBUFS; 1421 1422 nopt->dst1opt = ip6_opt_dup(opt->dst1opt, sk->sk_allocation); 1423 if (opt->dst1opt && !nopt->dst1opt) 1424 return -ENOBUFS; 1425 1426 nopt->hopopt = ip6_opt_dup(opt->hopopt, sk->sk_allocation); 1427 if (opt->hopopt && !nopt->hopopt) 1428 return -ENOBUFS; 1429 1430 nopt->srcrt = ip6_rthdr_dup(opt->srcrt, sk->sk_allocation); 1431 if (opt->srcrt && !nopt->srcrt) 1432 return -ENOBUFS; 1433 1434 /* need source address above miyazawa*/ 1435 } 1436 v6_cork->hop_limit = ipc6->hlimit; 1437 v6_cork->tclass = ipc6->tclass; 1438 if (rt->dst.flags & DST_XFRM_TUNNEL) 1439 mtu = np->pmtudisc >= IPV6_PMTUDISC_PROBE ? 1440 READ_ONCE(rt->dst.dev->mtu) : dst_mtu(&rt->dst); 1441 else 1442 mtu = np->pmtudisc >= IPV6_PMTUDISC_PROBE ? 1443 READ_ONCE(rt->dst.dev->mtu) : dst_mtu(xfrm_dst_path(&rt->dst)); 1444 if (np->frag_size < mtu) { 1445 if (np->frag_size) 1446 mtu = np->frag_size; 1447 } 1448 cork->base.fragsize = mtu; 1449 cork->base.gso_size = ipc6->gso_size; 1450 cork->base.tx_flags = 0; 1451 cork->base.mark = ipc6->sockc.mark; 1452 sock_tx_timestamp(sk, ipc6->sockc.tsflags, &cork->base.tx_flags); 1453 1454 if (dst_allfrag(xfrm_dst_path(&rt->dst))) 1455 cork->base.flags |= IPCORK_ALLFRAG; 1456 cork->base.length = 0; 1457 1458 cork->base.transmit_time = ipc6->sockc.transmit_time; 1459 1460 return 0; 1461 } 1462 1463 static int __ip6_append_data(struct sock *sk, 1464 struct sk_buff_head *queue, 1465 struct inet_cork_full *cork_full, 1466 struct inet6_cork *v6_cork, 1467 struct page_frag *pfrag, 1468 int getfrag(void *from, char *to, int offset, 1469 int len, int odd, struct sk_buff *skb), 1470 void *from, size_t length, int transhdrlen, 1471 unsigned int flags, struct ipcm6_cookie *ipc6) 1472 { 1473 struct sk_buff *skb, *skb_prev = NULL; 1474 struct inet_cork *cork = &cork_full->base; 1475 struct flowi6 *fl6 = &cork_full->fl.u.ip6; 1476 unsigned int maxfraglen, fragheaderlen, mtu, orig_mtu, pmtu; 1477 struct ubuf_info *uarg = NULL; 1478 int exthdrlen = 0; 1479 int dst_exthdrlen = 0; 1480 int hh_len; 1481 int copy; 1482 int err; 1483 int offset = 0; 1484 bool zc = false; 1485 u32 tskey = 0; 1486 struct rt6_info *rt = (struct rt6_info *)cork->dst; 1487 struct ipv6_txoptions *opt = v6_cork->opt; 1488 int csummode = CHECKSUM_NONE; 1489 unsigned int maxnonfragsize, headersize; 1490 unsigned int wmem_alloc_delta = 0; 1491 bool paged, extra_uref = false; 1492 1493 skb = skb_peek_tail(queue); 1494 if (!skb) { 1495 exthdrlen = opt ? opt->opt_flen : 0; 1496 dst_exthdrlen = rt->dst.header_len - rt->rt6i_nfheader_len; 1497 } 1498 1499 paged = !!cork->gso_size; 1500 mtu = cork->gso_size ? IP6_MAX_MTU : cork->fragsize; 1501 orig_mtu = mtu; 1502 1503 if (cork->tx_flags & SKBTX_ANY_SW_TSTAMP && 1504 sk->sk_tsflags & SOF_TIMESTAMPING_OPT_ID) 1505 tskey = atomic_inc_return(&sk->sk_tskey) - 1; 1506 1507 hh_len = LL_RESERVED_SPACE(rt->dst.dev); 1508 1509 fragheaderlen = sizeof(struct ipv6hdr) + rt->rt6i_nfheader_len + 1510 (opt ? opt->opt_nflen : 0); 1511 1512 headersize = sizeof(struct ipv6hdr) + 1513 (opt ? opt->opt_flen + opt->opt_nflen : 0) + 1514 (dst_allfrag(&rt->dst) ? 1515 sizeof(struct frag_hdr) : 0) + 1516 rt->rt6i_nfheader_len; 1517 1518 if (mtu <= fragheaderlen || 1519 ((mtu - fragheaderlen) & ~7) + fragheaderlen <= sizeof(struct frag_hdr)) 1520 goto emsgsize; 1521 1522 maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen - 1523 sizeof(struct frag_hdr); 1524 1525 /* as per RFC 7112 section 5, the entire IPv6 Header Chain must fit 1526 * the first fragment 1527 */ 1528 if (headersize + transhdrlen > mtu) 1529 goto emsgsize; 1530 1531 if (cork->length + length > mtu - headersize && ipc6->dontfrag && 1532 (sk->sk_protocol == IPPROTO_UDP || 1533 sk->sk_protocol == IPPROTO_ICMPV6 || 1534 sk->sk_protocol == IPPROTO_RAW)) { 1535 ipv6_local_rxpmtu(sk, fl6, mtu - headersize + 1536 sizeof(struct ipv6hdr)); 1537 goto emsgsize; 1538 } 1539 1540 if (ip6_sk_ignore_df(sk)) 1541 maxnonfragsize = sizeof(struct ipv6hdr) + IPV6_MAXPLEN; 1542 else 1543 maxnonfragsize = mtu; 1544 1545 if (cork->length + length > maxnonfragsize - headersize) { 1546 emsgsize: 1547 pmtu = max_t(int, mtu - headersize + sizeof(struct ipv6hdr), 0); 1548 ipv6_local_error(sk, EMSGSIZE, fl6, pmtu); 1549 return -EMSGSIZE; 1550 } 1551 1552 /* CHECKSUM_PARTIAL only with no extension headers and when 1553 * we are not going to fragment 1554 */ 1555 if (transhdrlen && sk->sk_protocol == IPPROTO_UDP && 1556 headersize == sizeof(struct ipv6hdr) && 1557 length <= mtu - headersize && 1558 (!(flags & MSG_MORE) || cork->gso_size) && 1559 rt->dst.dev->features & (NETIF_F_IPV6_CSUM | NETIF_F_HW_CSUM)) 1560 csummode = CHECKSUM_PARTIAL; 1561 1562 if ((flags & MSG_ZEROCOPY) && length) { 1563 struct msghdr *msg = from; 1564 1565 if (getfrag == ip_generic_getfrag && msg->msg_ubuf) { 1566 if (skb_zcopy(skb) && msg->msg_ubuf != skb_zcopy(skb)) 1567 return -EINVAL; 1568 1569 /* Leave uarg NULL if can't zerocopy, callers should 1570 * be able to handle it. 1571 */ 1572 if ((rt->dst.dev->features & NETIF_F_SG) && 1573 csummode == CHECKSUM_PARTIAL) { 1574 paged = true; 1575 zc = true; 1576 uarg = msg->msg_ubuf; 1577 } 1578 } else if (sock_flag(sk, SOCK_ZEROCOPY)) { 1579 uarg = msg_zerocopy_realloc(sk, length, skb_zcopy(skb)); 1580 if (!uarg) 1581 return -ENOBUFS; 1582 extra_uref = !skb_zcopy(skb); /* only ref on new uarg */ 1583 if (rt->dst.dev->features & NETIF_F_SG && 1584 csummode == CHECKSUM_PARTIAL) { 1585 paged = true; 1586 zc = true; 1587 } else { 1588 uarg_to_msgzc(uarg)->zerocopy = 0; 1589 skb_zcopy_set(skb, uarg, &extra_uref); 1590 } 1591 } 1592 } 1593 1594 /* 1595 * Let's try using as much space as possible. 1596 * Use MTU if total length of the message fits into the MTU. 1597 * Otherwise, we need to reserve fragment header and 1598 * fragment alignment (= 8-15 octects, in total). 1599 * 1600 * Note that we may need to "move" the data from the tail 1601 * of the buffer to the new fragment when we split 1602 * the message. 1603 * 1604 * FIXME: It may be fragmented into multiple chunks 1605 * at once if non-fragmentable extension headers 1606 * are too large. 1607 * --yoshfuji 1608 */ 1609 1610 cork->length += length; 1611 if (!skb) 1612 goto alloc_new_skb; 1613 1614 while (length > 0) { 1615 /* Check if the remaining data fits into current packet. */ 1616 copy = (cork->length <= mtu && !(cork->flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - skb->len; 1617 if (copy < length) 1618 copy = maxfraglen - skb->len; 1619 1620 if (copy <= 0) { 1621 char *data; 1622 unsigned int datalen; 1623 unsigned int fraglen; 1624 unsigned int fraggap; 1625 unsigned int alloclen, alloc_extra; 1626 unsigned int pagedlen; 1627 alloc_new_skb: 1628 /* There's no room in the current skb */ 1629 if (skb) 1630 fraggap = skb->len - maxfraglen; 1631 else 1632 fraggap = 0; 1633 /* update mtu and maxfraglen if necessary */ 1634 if (!skb || !skb_prev) 1635 ip6_append_data_mtu(&mtu, &maxfraglen, 1636 fragheaderlen, skb, rt, 1637 orig_mtu); 1638 1639 skb_prev = skb; 1640 1641 /* 1642 * If remaining data exceeds the mtu, 1643 * we know we need more fragment(s). 1644 */ 1645 datalen = length + fraggap; 1646 1647 if (datalen > (cork->length <= mtu && !(cork->flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - fragheaderlen) 1648 datalen = maxfraglen - fragheaderlen - rt->dst.trailer_len; 1649 fraglen = datalen + fragheaderlen; 1650 pagedlen = 0; 1651 1652 alloc_extra = hh_len; 1653 alloc_extra += dst_exthdrlen; 1654 alloc_extra += rt->dst.trailer_len; 1655 1656 /* We just reserve space for fragment header. 1657 * Note: this may be overallocation if the message 1658 * (without MSG_MORE) fits into the MTU. 1659 */ 1660 alloc_extra += sizeof(struct frag_hdr); 1661 1662 if ((flags & MSG_MORE) && 1663 !(rt->dst.dev->features&NETIF_F_SG)) 1664 alloclen = mtu; 1665 else if (!paged && 1666 (fraglen + alloc_extra < SKB_MAX_ALLOC || 1667 !(rt->dst.dev->features & NETIF_F_SG))) 1668 alloclen = fraglen; 1669 else { 1670 alloclen = fragheaderlen + transhdrlen; 1671 pagedlen = datalen - transhdrlen; 1672 } 1673 alloclen += alloc_extra; 1674 1675 if (datalen != length + fraggap) { 1676 /* 1677 * this is not the last fragment, the trailer 1678 * space is regarded as data space. 1679 */ 1680 datalen += rt->dst.trailer_len; 1681 } 1682 1683 fraglen = datalen + fragheaderlen; 1684 1685 copy = datalen - transhdrlen - fraggap - pagedlen; 1686 if (copy < 0) { 1687 err = -EINVAL; 1688 goto error; 1689 } 1690 if (transhdrlen) { 1691 skb = sock_alloc_send_skb(sk, alloclen, 1692 (flags & MSG_DONTWAIT), &err); 1693 } else { 1694 skb = NULL; 1695 if (refcount_read(&sk->sk_wmem_alloc) + wmem_alloc_delta <= 1696 2 * sk->sk_sndbuf) 1697 skb = alloc_skb(alloclen, 1698 sk->sk_allocation); 1699 if (unlikely(!skb)) 1700 err = -ENOBUFS; 1701 } 1702 if (!skb) 1703 goto error; 1704 /* 1705 * Fill in the control structures 1706 */ 1707 skb->protocol = htons(ETH_P_IPV6); 1708 skb->ip_summed = csummode; 1709 skb->csum = 0; 1710 /* reserve for fragmentation and ipsec header */ 1711 skb_reserve(skb, hh_len + sizeof(struct frag_hdr) + 1712 dst_exthdrlen); 1713 1714 /* 1715 * Find where to start putting bytes 1716 */ 1717 data = skb_put(skb, fraglen - pagedlen); 1718 skb_set_network_header(skb, exthdrlen); 1719 data += fragheaderlen; 1720 skb->transport_header = (skb->network_header + 1721 fragheaderlen); 1722 if (fraggap) { 1723 skb->csum = skb_copy_and_csum_bits( 1724 skb_prev, maxfraglen, 1725 data + transhdrlen, fraggap); 1726 skb_prev->csum = csum_sub(skb_prev->csum, 1727 skb->csum); 1728 data += fraggap; 1729 pskb_trim_unique(skb_prev, maxfraglen); 1730 } 1731 if (copy > 0 && 1732 getfrag(from, data + transhdrlen, offset, 1733 copy, fraggap, skb) < 0) { 1734 err = -EFAULT; 1735 kfree_skb(skb); 1736 goto error; 1737 } 1738 1739 offset += copy; 1740 length -= copy + transhdrlen; 1741 transhdrlen = 0; 1742 exthdrlen = 0; 1743 dst_exthdrlen = 0; 1744 1745 /* Only the initial fragment is time stamped */ 1746 skb_shinfo(skb)->tx_flags = cork->tx_flags; 1747 cork->tx_flags = 0; 1748 skb_shinfo(skb)->tskey = tskey; 1749 tskey = 0; 1750 skb_zcopy_set(skb, uarg, &extra_uref); 1751 1752 if ((flags & MSG_CONFIRM) && !skb_prev) 1753 skb_set_dst_pending_confirm(skb, 1); 1754 1755 /* 1756 * Put the packet on the pending queue 1757 */ 1758 if (!skb->destructor) { 1759 skb->destructor = sock_wfree; 1760 skb->sk = sk; 1761 wmem_alloc_delta += skb->truesize; 1762 } 1763 __skb_queue_tail(queue, skb); 1764 continue; 1765 } 1766 1767 if (copy > length) 1768 copy = length; 1769 1770 if (!(rt->dst.dev->features&NETIF_F_SG) && 1771 skb_tailroom(skb) >= copy) { 1772 unsigned int off; 1773 1774 off = skb->len; 1775 if (getfrag(from, skb_put(skb, copy), 1776 offset, copy, off, skb) < 0) { 1777 __skb_trim(skb, off); 1778 err = -EFAULT; 1779 goto error; 1780 } 1781 } else if (!zc) { 1782 int i = skb_shinfo(skb)->nr_frags; 1783 1784 err = -ENOMEM; 1785 if (!sk_page_frag_refill(sk, pfrag)) 1786 goto error; 1787 1788 skb_zcopy_downgrade_managed(skb); 1789 if (!skb_can_coalesce(skb, i, pfrag->page, 1790 pfrag->offset)) { 1791 err = -EMSGSIZE; 1792 if (i == MAX_SKB_FRAGS) 1793 goto error; 1794 1795 __skb_fill_page_desc(skb, i, pfrag->page, 1796 pfrag->offset, 0); 1797 skb_shinfo(skb)->nr_frags = ++i; 1798 get_page(pfrag->page); 1799 } 1800 copy = min_t(int, copy, pfrag->size - pfrag->offset); 1801 if (getfrag(from, 1802 page_address(pfrag->page) + pfrag->offset, 1803 offset, copy, skb->len, skb) < 0) 1804 goto error_efault; 1805 1806 pfrag->offset += copy; 1807 skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], copy); 1808 skb->len += copy; 1809 skb->data_len += copy; 1810 skb->truesize += copy; 1811 wmem_alloc_delta += copy; 1812 } else { 1813 err = skb_zerocopy_iter_dgram(skb, from, copy); 1814 if (err < 0) 1815 goto error; 1816 } 1817 offset += copy; 1818 length -= copy; 1819 } 1820 1821 if (wmem_alloc_delta) 1822 refcount_add(wmem_alloc_delta, &sk->sk_wmem_alloc); 1823 return 0; 1824 1825 error_efault: 1826 err = -EFAULT; 1827 error: 1828 net_zcopy_put_abort(uarg, extra_uref); 1829 cork->length -= length; 1830 IP6_INC_STATS(sock_net(sk), rt->rt6i_idev, IPSTATS_MIB_OUTDISCARDS); 1831 refcount_add(wmem_alloc_delta, &sk->sk_wmem_alloc); 1832 return err; 1833 } 1834 1835 int ip6_append_data(struct sock *sk, 1836 int getfrag(void *from, char *to, int offset, int len, 1837 int odd, struct sk_buff *skb), 1838 void *from, size_t length, int transhdrlen, 1839 struct ipcm6_cookie *ipc6, struct flowi6 *fl6, 1840 struct rt6_info *rt, unsigned int flags) 1841 { 1842 struct inet_sock *inet = inet_sk(sk); 1843 struct ipv6_pinfo *np = inet6_sk(sk); 1844 int exthdrlen; 1845 int err; 1846 1847 if (flags&MSG_PROBE) 1848 return 0; 1849 if (skb_queue_empty(&sk->sk_write_queue)) { 1850 /* 1851 * setup for corking 1852 */ 1853 dst_hold(&rt->dst); 1854 err = ip6_setup_cork(sk, &inet->cork, &np->cork, 1855 ipc6, rt); 1856 if (err) 1857 return err; 1858 1859 inet->cork.fl.u.ip6 = *fl6; 1860 exthdrlen = (ipc6->opt ? ipc6->opt->opt_flen : 0); 1861 length += exthdrlen; 1862 transhdrlen += exthdrlen; 1863 } else { 1864 transhdrlen = 0; 1865 } 1866 1867 return __ip6_append_data(sk, &sk->sk_write_queue, &inet->cork, 1868 &np->cork, sk_page_frag(sk), getfrag, 1869 from, length, transhdrlen, flags, ipc6); 1870 } 1871 EXPORT_SYMBOL_GPL(ip6_append_data); 1872 1873 static void ip6_cork_steal_dst(struct sk_buff *skb, struct inet_cork_full *cork) 1874 { 1875 struct dst_entry *dst = cork->base.dst; 1876 1877 cork->base.dst = NULL; 1878 cork->base.flags &= ~IPCORK_ALLFRAG; 1879 skb_dst_set(skb, dst); 1880 } 1881 1882 static void ip6_cork_release(struct inet_cork_full *cork, 1883 struct inet6_cork *v6_cork) 1884 { 1885 if (v6_cork->opt) { 1886 struct ipv6_txoptions *opt = v6_cork->opt; 1887 1888 kfree(opt->dst0opt); 1889 kfree(opt->dst1opt); 1890 kfree(opt->hopopt); 1891 kfree(opt->srcrt); 1892 kfree(opt); 1893 v6_cork->opt = NULL; 1894 } 1895 1896 if (cork->base.dst) { 1897 dst_release(cork->base.dst); 1898 cork->base.dst = NULL; 1899 cork->base.flags &= ~IPCORK_ALLFRAG; 1900 } 1901 } 1902 1903 struct sk_buff *__ip6_make_skb(struct sock *sk, 1904 struct sk_buff_head *queue, 1905 struct inet_cork_full *cork, 1906 struct inet6_cork *v6_cork) 1907 { 1908 struct sk_buff *skb, *tmp_skb; 1909 struct sk_buff **tail_skb; 1910 struct in6_addr *final_dst; 1911 struct ipv6_pinfo *np = inet6_sk(sk); 1912 struct net *net = sock_net(sk); 1913 struct ipv6hdr *hdr; 1914 struct ipv6_txoptions *opt = v6_cork->opt; 1915 struct rt6_info *rt = (struct rt6_info *)cork->base.dst; 1916 struct flowi6 *fl6 = &cork->fl.u.ip6; 1917 unsigned char proto = fl6->flowi6_proto; 1918 1919 skb = __skb_dequeue(queue); 1920 if (!skb) 1921 goto out; 1922 tail_skb = &(skb_shinfo(skb)->frag_list); 1923 1924 /* move skb->data to ip header from ext header */ 1925 if (skb->data < skb_network_header(skb)) 1926 __skb_pull(skb, skb_network_offset(skb)); 1927 while ((tmp_skb = __skb_dequeue(queue)) != NULL) { 1928 __skb_pull(tmp_skb, skb_network_header_len(skb)); 1929 *tail_skb = tmp_skb; 1930 tail_skb = &(tmp_skb->next); 1931 skb->len += tmp_skb->len; 1932 skb->data_len += tmp_skb->len; 1933 skb->truesize += tmp_skb->truesize; 1934 tmp_skb->destructor = NULL; 1935 tmp_skb->sk = NULL; 1936 } 1937 1938 /* Allow local fragmentation. */ 1939 skb->ignore_df = ip6_sk_ignore_df(sk); 1940 __skb_pull(skb, skb_network_header_len(skb)); 1941 1942 final_dst = &fl6->daddr; 1943 if (opt && opt->opt_flen) 1944 ipv6_push_frag_opts(skb, opt, &proto); 1945 if (opt && opt->opt_nflen) 1946 ipv6_push_nfrag_opts(skb, opt, &proto, &final_dst, &fl6->saddr); 1947 1948 skb_push(skb, sizeof(struct ipv6hdr)); 1949 skb_reset_network_header(skb); 1950 hdr = ipv6_hdr(skb); 1951 1952 ip6_flow_hdr(hdr, v6_cork->tclass, 1953 ip6_make_flowlabel(net, skb, fl6->flowlabel, 1954 ip6_autoflowlabel(net, np), fl6)); 1955 hdr->hop_limit = v6_cork->hop_limit; 1956 hdr->nexthdr = proto; 1957 hdr->saddr = fl6->saddr; 1958 hdr->daddr = *final_dst; 1959 1960 skb->priority = sk->sk_priority; 1961 skb->mark = cork->base.mark; 1962 skb->tstamp = cork->base.transmit_time; 1963 1964 ip6_cork_steal_dst(skb, cork); 1965 IP6_UPD_PO_STATS(net, rt->rt6i_idev, IPSTATS_MIB_OUT, skb->len); 1966 if (proto == IPPROTO_ICMPV6) { 1967 struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb)); 1968 u8 icmp6_type; 1969 1970 if (sk->sk_socket->type == SOCK_RAW && !inet_sk(sk)->hdrincl) 1971 icmp6_type = fl6->fl6_icmp_type; 1972 else 1973 icmp6_type = icmp6_hdr(skb)->icmp6_type; 1974 ICMP6MSGOUT_INC_STATS(net, idev, icmp6_type); 1975 ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTMSGS); 1976 } 1977 1978 ip6_cork_release(cork, v6_cork); 1979 out: 1980 return skb; 1981 } 1982 1983 int ip6_send_skb(struct sk_buff *skb) 1984 { 1985 struct net *net = sock_net(skb->sk); 1986 struct rt6_info *rt = (struct rt6_info *)skb_dst(skb); 1987 int err; 1988 1989 err = ip6_local_out(net, skb->sk, skb); 1990 if (err) { 1991 if (err > 0) 1992 err = net_xmit_errno(err); 1993 if (err) 1994 IP6_INC_STATS(net, rt->rt6i_idev, 1995 IPSTATS_MIB_OUTDISCARDS); 1996 } 1997 1998 return err; 1999 } 2000 2001 int ip6_push_pending_frames(struct sock *sk) 2002 { 2003 struct sk_buff *skb; 2004 2005 skb = ip6_finish_skb(sk); 2006 if (!skb) 2007 return 0; 2008 2009 return ip6_send_skb(skb); 2010 } 2011 EXPORT_SYMBOL_GPL(ip6_push_pending_frames); 2012 2013 static void __ip6_flush_pending_frames(struct sock *sk, 2014 struct sk_buff_head *queue, 2015 struct inet_cork_full *cork, 2016 struct inet6_cork *v6_cork) 2017 { 2018 struct sk_buff *skb; 2019 2020 while ((skb = __skb_dequeue_tail(queue)) != NULL) { 2021 if (skb_dst(skb)) 2022 IP6_INC_STATS(sock_net(sk), ip6_dst_idev(skb_dst(skb)), 2023 IPSTATS_MIB_OUTDISCARDS); 2024 kfree_skb(skb); 2025 } 2026 2027 ip6_cork_release(cork, v6_cork); 2028 } 2029 2030 void ip6_flush_pending_frames(struct sock *sk) 2031 { 2032 __ip6_flush_pending_frames(sk, &sk->sk_write_queue, 2033 &inet_sk(sk)->cork, &inet6_sk(sk)->cork); 2034 } 2035 EXPORT_SYMBOL_GPL(ip6_flush_pending_frames); 2036 2037 struct sk_buff *ip6_make_skb(struct sock *sk, 2038 int getfrag(void *from, char *to, int offset, 2039 int len, int odd, struct sk_buff *skb), 2040 void *from, size_t length, int transhdrlen, 2041 struct ipcm6_cookie *ipc6, struct rt6_info *rt, 2042 unsigned int flags, struct inet_cork_full *cork) 2043 { 2044 struct inet6_cork v6_cork; 2045 struct sk_buff_head queue; 2046 int exthdrlen = (ipc6->opt ? ipc6->opt->opt_flen : 0); 2047 int err; 2048 2049 if (flags & MSG_PROBE) { 2050 dst_release(&rt->dst); 2051 return NULL; 2052 } 2053 2054 __skb_queue_head_init(&queue); 2055 2056 cork->base.flags = 0; 2057 cork->base.addr = 0; 2058 cork->base.opt = NULL; 2059 v6_cork.opt = NULL; 2060 err = ip6_setup_cork(sk, cork, &v6_cork, ipc6, rt); 2061 if (err) { 2062 ip6_cork_release(cork, &v6_cork); 2063 return ERR_PTR(err); 2064 } 2065 if (ipc6->dontfrag < 0) 2066 ipc6->dontfrag = inet6_sk(sk)->dontfrag; 2067 2068 err = __ip6_append_data(sk, &queue, cork, &v6_cork, 2069 ¤t->task_frag, getfrag, from, 2070 length + exthdrlen, transhdrlen + exthdrlen, 2071 flags, ipc6); 2072 if (err) { 2073 __ip6_flush_pending_frames(sk, &queue, cork, &v6_cork); 2074 return ERR_PTR(err); 2075 } 2076 2077 return __ip6_make_skb(sk, &queue, cork, &v6_cork); 2078 } 2079