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/gso.h> 46 #include <net/ipv6.h> 47 #include <net/ndisc.h> 48 #include <net/protocol.h> 49 #include <net/ip6_route.h> 50 #include <net/addrconf.h> 51 #include <net/rawv6.h> 52 #include <net/icmp.h> 53 #include <net/xfrm.h> 54 #include <net/checksum.h> 55 #include <linux/mroute6.h> 56 #include <net/l3mdev.h> 57 #include <net/lwtunnel.h> 58 #include <net/ip_tunnels.h> 59 60 static int ip6_finish_output2(struct net *net, struct sock *sk, struct sk_buff *skb) 61 { 62 struct dst_entry *dst = skb_dst(skb); 63 struct net_device *dev = dst->dev; 64 struct inet6_dev *idev = ip6_dst_idev(dst); 65 unsigned int hh_len = LL_RESERVED_SPACE(dev); 66 const struct in6_addr *daddr, *nexthop; 67 struct ipv6hdr *hdr; 68 struct neighbour *neigh; 69 int ret; 70 71 /* Be paranoid, rather than too clever. */ 72 if (unlikely(hh_len > skb_headroom(skb)) && dev->header_ops) { 73 skb = skb_expand_head(skb, hh_len); 74 if (!skb) { 75 IP6_INC_STATS(net, idev, IPSTATS_MIB_OUTDISCARDS); 76 return -ENOMEM; 77 } 78 } 79 80 hdr = ipv6_hdr(skb); 81 daddr = &hdr->daddr; 82 if (ipv6_addr_is_multicast(daddr)) { 83 if (!(dev->flags & IFF_LOOPBACK) && sk_mc_loop(sk) && 84 ((mroute6_is_socket(net, skb) && 85 !(IP6CB(skb)->flags & IP6SKB_FORWARDED)) || 86 ipv6_chk_mcast_addr(dev, daddr, &hdr->saddr))) { 87 struct sk_buff *newskb = skb_clone(skb, GFP_ATOMIC); 88 89 /* Do not check for IFF_ALLMULTI; multicast routing 90 is not supported in any case. 91 */ 92 if (newskb) 93 NF_HOOK(NFPROTO_IPV6, NF_INET_POST_ROUTING, 94 net, sk, newskb, NULL, newskb->dev, 95 dev_loopback_xmit); 96 97 if (hdr->hop_limit == 0) { 98 IP6_INC_STATS(net, idev, 99 IPSTATS_MIB_OUTDISCARDS); 100 kfree_skb(skb); 101 return 0; 102 } 103 } 104 105 IP6_UPD_PO_STATS(net, idev, IPSTATS_MIB_OUTMCAST, skb->len); 106 if (IPV6_ADDR_MC_SCOPE(daddr) <= IPV6_ADDR_SCOPE_NODELOCAL && 107 !(dev->flags & IFF_LOOPBACK)) { 108 kfree_skb(skb); 109 return 0; 110 } 111 } 112 113 if (lwtunnel_xmit_redirect(dst->lwtstate)) { 114 int res = lwtunnel_xmit(skb); 115 116 if (res < 0 || res == LWTUNNEL_XMIT_DONE) 117 return res; 118 } 119 120 rcu_read_lock(); 121 nexthop = rt6_nexthop((struct rt6_info *)dst, daddr); 122 neigh = __ipv6_neigh_lookup_noref(dev, nexthop); 123 124 if (unlikely(IS_ERR_OR_NULL(neigh))) { 125 if (unlikely(!neigh)) 126 neigh = __neigh_create(&nd_tbl, nexthop, dev, false); 127 if (IS_ERR(neigh)) { 128 rcu_read_unlock(); 129 IP6_INC_STATS(net, idev, IPSTATS_MIB_OUTNOROUTES); 130 kfree_skb_reason(skb, SKB_DROP_REASON_NEIGH_CREATEFAIL); 131 return -EINVAL; 132 } 133 } 134 sock_confirm_neigh(skb, neigh); 135 ret = neigh_output(neigh, skb, false); 136 rcu_read_unlock(); 137 return ret; 138 } 139 140 static int 141 ip6_finish_output_gso_slowpath_drop(struct net *net, struct sock *sk, 142 struct sk_buff *skb, unsigned int mtu) 143 { 144 struct sk_buff *segs, *nskb; 145 netdev_features_t features; 146 int ret = 0; 147 148 /* Please see corresponding comment in ip_finish_output_gso 149 * describing the cases where GSO segment length exceeds the 150 * egress MTU. 151 */ 152 features = netif_skb_features(skb); 153 segs = skb_gso_segment(skb, features & ~NETIF_F_GSO_MASK); 154 if (IS_ERR_OR_NULL(segs)) { 155 kfree_skb(skb); 156 return -ENOMEM; 157 } 158 159 consume_skb(skb); 160 161 skb_list_walk_safe(segs, segs, nskb) { 162 int err; 163 164 skb_mark_not_on_list(segs); 165 err = ip6_fragment(net, sk, segs, ip6_finish_output2); 166 if (err && ret == 0) 167 ret = err; 168 } 169 170 return ret; 171 } 172 173 static int __ip6_finish_output(struct net *net, struct sock *sk, struct sk_buff *skb) 174 { 175 unsigned int mtu; 176 177 #if defined(CONFIG_NETFILTER) && defined(CONFIG_XFRM) 178 /* Policy lookup after SNAT yielded a new policy */ 179 if (skb_dst(skb)->xfrm) { 180 IP6CB(skb)->flags |= IP6SKB_REROUTED; 181 return dst_output(net, sk, skb); 182 } 183 #endif 184 185 mtu = ip6_skb_dst_mtu(skb); 186 if (skb_is_gso(skb) && 187 !(IP6CB(skb)->flags & IP6SKB_FAKEJUMBO) && 188 !skb_gso_validate_network_len(skb, mtu)) 189 return ip6_finish_output_gso_slowpath_drop(net, sk, skb, mtu); 190 191 if ((skb->len > mtu && !skb_is_gso(skb)) || 192 dst_allfrag(skb_dst(skb)) || 193 (IP6CB(skb)->frag_max_size && skb->len > IP6CB(skb)->frag_max_size)) 194 return ip6_fragment(net, sk, skb, ip6_finish_output2); 195 else 196 return ip6_finish_output2(net, sk, skb); 197 } 198 199 static int ip6_finish_output(struct net *net, struct sock *sk, struct sk_buff *skb) 200 { 201 int ret; 202 203 ret = BPF_CGROUP_RUN_PROG_INET_EGRESS(sk, skb); 204 switch (ret) { 205 case NET_XMIT_SUCCESS: 206 case NET_XMIT_CN: 207 return __ip6_finish_output(net, sk, skb) ? : ret; 208 default: 209 kfree_skb_reason(skb, SKB_DROP_REASON_BPF_CGROUP_EGRESS); 210 return ret; 211 } 212 } 213 214 int ip6_output(struct net *net, struct sock *sk, struct sk_buff *skb) 215 { 216 struct net_device *dev = skb_dst(skb)->dev, *indev = skb->dev; 217 struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb)); 218 219 skb->protocol = htons(ETH_P_IPV6); 220 skb->dev = dev; 221 222 if (unlikely(idev->cnf.disable_ipv6)) { 223 IP6_INC_STATS(net, idev, IPSTATS_MIB_OUTDISCARDS); 224 kfree_skb_reason(skb, SKB_DROP_REASON_IPV6DISABLED); 225 return 0; 226 } 227 228 return NF_HOOK_COND(NFPROTO_IPV6, NF_INET_POST_ROUTING, 229 net, sk, skb, indev, dev, 230 ip6_finish_output, 231 !(IP6CB(skb)->flags & IP6SKB_REROUTED)); 232 } 233 EXPORT_SYMBOL(ip6_output); 234 235 bool ip6_autoflowlabel(struct net *net, const struct ipv6_pinfo *np) 236 { 237 if (!np->autoflowlabel_set) 238 return ip6_default_np_autolabel(net); 239 else 240 return np->autoflowlabel; 241 } 242 243 /* 244 * xmit an sk_buff (used by TCP, SCTP and DCCP) 245 * Note : socket lock is not held for SYNACK packets, but might be modified 246 * by calls to skb_set_owner_w() and ipv6_local_error(), 247 * which are using proper atomic operations or spinlocks. 248 */ 249 int ip6_xmit(const struct sock *sk, struct sk_buff *skb, struct flowi6 *fl6, 250 __u32 mark, struct ipv6_txoptions *opt, int tclass, u32 priority) 251 { 252 struct net *net = sock_net(sk); 253 const struct ipv6_pinfo *np = inet6_sk(sk); 254 struct in6_addr *first_hop = &fl6->daddr; 255 struct dst_entry *dst = skb_dst(skb); 256 struct net_device *dev = dst->dev; 257 struct inet6_dev *idev = ip6_dst_idev(dst); 258 struct hop_jumbo_hdr *hop_jumbo; 259 int hoplen = sizeof(*hop_jumbo); 260 unsigned int head_room; 261 struct ipv6hdr *hdr; 262 u8 proto = fl6->flowi6_proto; 263 int seg_len = skb->len; 264 int hlimit = -1; 265 u32 mtu; 266 267 head_room = sizeof(struct ipv6hdr) + hoplen + LL_RESERVED_SPACE(dev); 268 if (opt) 269 head_room += opt->opt_nflen + opt->opt_flen; 270 271 if (unlikely(head_room > skb_headroom(skb))) { 272 skb = skb_expand_head(skb, head_room); 273 if (!skb) { 274 IP6_INC_STATS(net, idev, IPSTATS_MIB_OUTDISCARDS); 275 return -ENOBUFS; 276 } 277 } 278 279 if (opt) { 280 seg_len += opt->opt_nflen + opt->opt_flen; 281 282 if (opt->opt_flen) 283 ipv6_push_frag_opts(skb, opt, &proto); 284 285 if (opt->opt_nflen) 286 ipv6_push_nfrag_opts(skb, opt, &proto, &first_hop, 287 &fl6->saddr); 288 } 289 290 if (unlikely(seg_len > IPV6_MAXPLEN)) { 291 hop_jumbo = skb_push(skb, hoplen); 292 293 hop_jumbo->nexthdr = proto; 294 hop_jumbo->hdrlen = 0; 295 hop_jumbo->tlv_type = IPV6_TLV_JUMBO; 296 hop_jumbo->tlv_len = 4; 297 hop_jumbo->jumbo_payload_len = htonl(seg_len + hoplen); 298 299 proto = IPPROTO_HOPOPTS; 300 seg_len = 0; 301 IP6CB(skb)->flags |= IP6SKB_FAKEJUMBO; 302 } 303 304 skb_push(skb, sizeof(struct ipv6hdr)); 305 skb_reset_network_header(skb); 306 hdr = ipv6_hdr(skb); 307 308 /* 309 * Fill in the IPv6 header 310 */ 311 if (np) 312 hlimit = np->hop_limit; 313 if (hlimit < 0) 314 hlimit = ip6_dst_hoplimit(dst); 315 316 ip6_flow_hdr(hdr, tclass, ip6_make_flowlabel(net, skb, fl6->flowlabel, 317 ip6_autoflowlabel(net, np), fl6)); 318 319 hdr->payload_len = htons(seg_len); 320 hdr->nexthdr = proto; 321 hdr->hop_limit = hlimit; 322 323 hdr->saddr = fl6->saddr; 324 hdr->daddr = *first_hop; 325 326 skb->protocol = htons(ETH_P_IPV6); 327 skb->priority = priority; 328 skb->mark = mark; 329 330 mtu = dst_mtu(dst); 331 if ((skb->len <= mtu) || skb->ignore_df || skb_is_gso(skb)) { 332 IP6_UPD_PO_STATS(net, idev, IPSTATS_MIB_OUT, skb->len); 333 334 /* if egress device is enslaved to an L3 master device pass the 335 * skb to its handler for processing 336 */ 337 skb = l3mdev_ip6_out((struct sock *)sk, skb); 338 if (unlikely(!skb)) 339 return 0; 340 341 /* hooks should never assume socket lock is held. 342 * we promote our socket to non const 343 */ 344 return NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT, 345 net, (struct sock *)sk, skb, NULL, dev, 346 dst_output); 347 } 348 349 skb->dev = dev; 350 /* ipv6_local_error() does not require socket lock, 351 * we promote our socket to non const 352 */ 353 ipv6_local_error((struct sock *)sk, EMSGSIZE, fl6, mtu); 354 355 IP6_INC_STATS(net, idev, IPSTATS_MIB_FRAGFAILS); 356 kfree_skb(skb); 357 return -EMSGSIZE; 358 } 359 EXPORT_SYMBOL(ip6_xmit); 360 361 static int ip6_call_ra_chain(struct sk_buff *skb, int sel) 362 { 363 struct ip6_ra_chain *ra; 364 struct sock *last = NULL; 365 366 read_lock(&ip6_ra_lock); 367 for (ra = ip6_ra_chain; ra; ra = ra->next) { 368 struct sock *sk = ra->sk; 369 if (sk && ra->sel == sel && 370 (!sk->sk_bound_dev_if || 371 sk->sk_bound_dev_if == skb->dev->ifindex)) { 372 struct ipv6_pinfo *np = inet6_sk(sk); 373 374 if (np && np->rtalert_isolate && 375 !net_eq(sock_net(sk), dev_net(skb->dev))) { 376 continue; 377 } 378 if (last) { 379 struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC); 380 if (skb2) 381 rawv6_rcv(last, skb2); 382 } 383 last = sk; 384 } 385 } 386 387 if (last) { 388 rawv6_rcv(last, skb); 389 read_unlock(&ip6_ra_lock); 390 return 1; 391 } 392 read_unlock(&ip6_ra_lock); 393 return 0; 394 } 395 396 static int ip6_forward_proxy_check(struct sk_buff *skb) 397 { 398 struct ipv6hdr *hdr = ipv6_hdr(skb); 399 u8 nexthdr = hdr->nexthdr; 400 __be16 frag_off; 401 int offset; 402 403 if (ipv6_ext_hdr(nexthdr)) { 404 offset = ipv6_skip_exthdr(skb, sizeof(*hdr), &nexthdr, &frag_off); 405 if (offset < 0) 406 return 0; 407 } else 408 offset = sizeof(struct ipv6hdr); 409 410 if (nexthdr == IPPROTO_ICMPV6) { 411 struct icmp6hdr *icmp6; 412 413 if (!pskb_may_pull(skb, (skb_network_header(skb) + 414 offset + 1 - skb->data))) 415 return 0; 416 417 icmp6 = (struct icmp6hdr *)(skb_network_header(skb) + offset); 418 419 switch (icmp6->icmp6_type) { 420 case NDISC_ROUTER_SOLICITATION: 421 case NDISC_ROUTER_ADVERTISEMENT: 422 case NDISC_NEIGHBOUR_SOLICITATION: 423 case NDISC_NEIGHBOUR_ADVERTISEMENT: 424 case NDISC_REDIRECT: 425 /* For reaction involving unicast neighbor discovery 426 * message destined to the proxied address, pass it to 427 * input function. 428 */ 429 return 1; 430 default: 431 break; 432 } 433 } 434 435 /* 436 * The proxying router can't forward traffic sent to a link-local 437 * address, so signal the sender and discard the packet. This 438 * behavior is clarified by the MIPv6 specification. 439 */ 440 if (ipv6_addr_type(&hdr->daddr) & IPV6_ADDR_LINKLOCAL) { 441 dst_link_failure(skb); 442 return -1; 443 } 444 445 return 0; 446 } 447 448 static inline int ip6_forward_finish(struct net *net, struct sock *sk, 449 struct sk_buff *skb) 450 { 451 struct dst_entry *dst = skb_dst(skb); 452 453 __IP6_INC_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTFORWDATAGRAMS); 454 __IP6_ADD_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTOCTETS, skb->len); 455 456 #ifdef CONFIG_NET_SWITCHDEV 457 if (skb->offload_l3_fwd_mark) { 458 consume_skb(skb); 459 return 0; 460 } 461 #endif 462 463 skb_clear_tstamp(skb); 464 return dst_output(net, sk, skb); 465 } 466 467 static bool ip6_pkt_too_big(const struct sk_buff *skb, unsigned int mtu) 468 { 469 if (skb->len <= mtu) 470 return false; 471 472 /* ipv6 conntrack defrag sets max_frag_size + ignore_df */ 473 if (IP6CB(skb)->frag_max_size && IP6CB(skb)->frag_max_size > mtu) 474 return true; 475 476 if (skb->ignore_df) 477 return false; 478 479 if (skb_is_gso(skb) && skb_gso_validate_network_len(skb, mtu)) 480 return false; 481 482 return true; 483 } 484 485 int ip6_forward(struct sk_buff *skb) 486 { 487 struct dst_entry *dst = skb_dst(skb); 488 struct ipv6hdr *hdr = ipv6_hdr(skb); 489 struct inet6_skb_parm *opt = IP6CB(skb); 490 struct net *net = dev_net(dst->dev); 491 struct inet6_dev *idev; 492 SKB_DR(reason); 493 u32 mtu; 494 495 idev = __in6_dev_get_safely(dev_get_by_index_rcu(net, IP6CB(skb)->iif)); 496 if (net->ipv6.devconf_all->forwarding == 0) 497 goto error; 498 499 if (skb->pkt_type != PACKET_HOST) 500 goto drop; 501 502 if (unlikely(skb->sk)) 503 goto drop; 504 505 if (skb_warn_if_lro(skb)) 506 goto drop; 507 508 if (!net->ipv6.devconf_all->disable_policy && 509 (!idev || !idev->cnf.disable_policy) && 510 !xfrm6_policy_check(NULL, XFRM_POLICY_FWD, skb)) { 511 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INDISCARDS); 512 goto drop; 513 } 514 515 skb_forward_csum(skb); 516 517 /* 518 * We DO NOT make any processing on 519 * RA packets, pushing them to user level AS IS 520 * without ane WARRANTY that application will be able 521 * to interpret them. The reason is that we 522 * cannot make anything clever here. 523 * 524 * We are not end-node, so that if packet contains 525 * AH/ESP, we cannot make anything. 526 * Defragmentation also would be mistake, RA packets 527 * cannot be fragmented, because there is no warranty 528 * that different fragments will go along one path. --ANK 529 */ 530 if (unlikely(opt->flags & IP6SKB_ROUTERALERT)) { 531 if (ip6_call_ra_chain(skb, ntohs(opt->ra))) 532 return 0; 533 } 534 535 /* 536 * check and decrement ttl 537 */ 538 if (hdr->hop_limit <= 1) { 539 icmpv6_send(skb, ICMPV6_TIME_EXCEED, ICMPV6_EXC_HOPLIMIT, 0); 540 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); 541 542 kfree_skb_reason(skb, SKB_DROP_REASON_IP_INHDR); 543 return -ETIMEDOUT; 544 } 545 546 /* XXX: idev->cnf.proxy_ndp? */ 547 if (net->ipv6.devconf_all->proxy_ndp && 548 pneigh_lookup(&nd_tbl, net, &hdr->daddr, skb->dev, 0)) { 549 int proxied = ip6_forward_proxy_check(skb); 550 if (proxied > 0) { 551 /* It's tempting to decrease the hop limit 552 * here by 1, as we do at the end of the 553 * function too. 554 * 555 * But that would be incorrect, as proxying is 556 * not forwarding. The ip6_input function 557 * will handle this packet locally, and it 558 * depends on the hop limit being unchanged. 559 * 560 * One example is the NDP hop limit, that 561 * always has to stay 255, but other would be 562 * similar checks around RA packets, where the 563 * user can even change the desired limit. 564 */ 565 return ip6_input(skb); 566 } else if (proxied < 0) { 567 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INDISCARDS); 568 goto drop; 569 } 570 } 571 572 if (!xfrm6_route_forward(skb)) { 573 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INDISCARDS); 574 SKB_DR_SET(reason, XFRM_POLICY); 575 goto drop; 576 } 577 dst = skb_dst(skb); 578 579 /* IPv6 specs say nothing about it, but it is clear that we cannot 580 send redirects to source routed frames. 581 We don't send redirects to frames decapsulated from IPsec. 582 */ 583 if (IP6CB(skb)->iif == dst->dev->ifindex && 584 opt->srcrt == 0 && !skb_sec_path(skb)) { 585 struct in6_addr *target = NULL; 586 struct inet_peer *peer; 587 struct rt6_info *rt; 588 589 /* 590 * incoming and outgoing devices are the same 591 * send a redirect. 592 */ 593 594 rt = (struct rt6_info *) dst; 595 if (rt->rt6i_flags & RTF_GATEWAY) 596 target = &rt->rt6i_gateway; 597 else 598 target = &hdr->daddr; 599 600 peer = inet_getpeer_v6(net->ipv6.peers, &hdr->daddr, 1); 601 602 /* Limit redirects both by destination (here) 603 and by source (inside ndisc_send_redirect) 604 */ 605 if (inet_peer_xrlim_allow(peer, 1*HZ)) 606 ndisc_send_redirect(skb, target); 607 if (peer) 608 inet_putpeer(peer); 609 } else { 610 int addrtype = ipv6_addr_type(&hdr->saddr); 611 612 /* This check is security critical. */ 613 if (addrtype == IPV6_ADDR_ANY || 614 addrtype & (IPV6_ADDR_MULTICAST | IPV6_ADDR_LOOPBACK)) 615 goto error; 616 if (addrtype & IPV6_ADDR_LINKLOCAL) { 617 icmpv6_send(skb, ICMPV6_DEST_UNREACH, 618 ICMPV6_NOT_NEIGHBOUR, 0); 619 goto error; 620 } 621 } 622 623 mtu = ip6_dst_mtu_maybe_forward(dst, true); 624 if (mtu < IPV6_MIN_MTU) 625 mtu = IPV6_MIN_MTU; 626 627 if (ip6_pkt_too_big(skb, mtu)) { 628 /* Again, force OUTPUT device used as source address */ 629 skb->dev = dst->dev; 630 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu); 631 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INTOOBIGERRORS); 632 __IP6_INC_STATS(net, ip6_dst_idev(dst), 633 IPSTATS_MIB_FRAGFAILS); 634 kfree_skb_reason(skb, SKB_DROP_REASON_PKT_TOO_BIG); 635 return -EMSGSIZE; 636 } 637 638 if (skb_cow(skb, dst->dev->hard_header_len)) { 639 __IP6_INC_STATS(net, ip6_dst_idev(dst), 640 IPSTATS_MIB_OUTDISCARDS); 641 goto drop; 642 } 643 644 hdr = ipv6_hdr(skb); 645 646 /* Mangling hops number delayed to point after skb COW */ 647 648 hdr->hop_limit--; 649 650 return NF_HOOK(NFPROTO_IPV6, NF_INET_FORWARD, 651 net, NULL, skb, skb->dev, dst->dev, 652 ip6_forward_finish); 653 654 error: 655 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INADDRERRORS); 656 SKB_DR_SET(reason, IP_INADDRERRORS); 657 drop: 658 kfree_skb_reason(skb, reason); 659 return -EINVAL; 660 } 661 662 static void ip6_copy_metadata(struct sk_buff *to, struct sk_buff *from) 663 { 664 to->pkt_type = from->pkt_type; 665 to->priority = from->priority; 666 to->protocol = from->protocol; 667 skb_dst_drop(to); 668 skb_dst_set(to, dst_clone(skb_dst(from))); 669 to->dev = from->dev; 670 to->mark = from->mark; 671 672 skb_copy_hash(to, from); 673 674 #ifdef CONFIG_NET_SCHED 675 to->tc_index = from->tc_index; 676 #endif 677 nf_copy(to, from); 678 skb_ext_copy(to, from); 679 skb_copy_secmark(to, from); 680 } 681 682 int ip6_fraglist_init(struct sk_buff *skb, unsigned int hlen, u8 *prevhdr, 683 u8 nexthdr, __be32 frag_id, 684 struct ip6_fraglist_iter *iter) 685 { 686 unsigned int first_len; 687 struct frag_hdr *fh; 688 689 /* BUILD HEADER */ 690 *prevhdr = NEXTHDR_FRAGMENT; 691 iter->tmp_hdr = kmemdup(skb_network_header(skb), hlen, GFP_ATOMIC); 692 if (!iter->tmp_hdr) 693 return -ENOMEM; 694 695 iter->frag = skb_shinfo(skb)->frag_list; 696 skb_frag_list_init(skb); 697 698 iter->offset = 0; 699 iter->hlen = hlen; 700 iter->frag_id = frag_id; 701 iter->nexthdr = nexthdr; 702 703 __skb_pull(skb, hlen); 704 fh = __skb_push(skb, sizeof(struct frag_hdr)); 705 __skb_push(skb, hlen); 706 skb_reset_network_header(skb); 707 memcpy(skb_network_header(skb), iter->tmp_hdr, hlen); 708 709 fh->nexthdr = nexthdr; 710 fh->reserved = 0; 711 fh->frag_off = htons(IP6_MF); 712 fh->identification = frag_id; 713 714 first_len = skb_pagelen(skb); 715 skb->data_len = first_len - skb_headlen(skb); 716 skb->len = first_len; 717 ipv6_hdr(skb)->payload_len = htons(first_len - sizeof(struct ipv6hdr)); 718 719 return 0; 720 } 721 EXPORT_SYMBOL(ip6_fraglist_init); 722 723 void ip6_fraglist_prepare(struct sk_buff *skb, 724 struct ip6_fraglist_iter *iter) 725 { 726 struct sk_buff *frag = iter->frag; 727 unsigned int hlen = iter->hlen; 728 struct frag_hdr *fh; 729 730 frag->ip_summed = CHECKSUM_NONE; 731 skb_reset_transport_header(frag); 732 fh = __skb_push(frag, sizeof(struct frag_hdr)); 733 __skb_push(frag, hlen); 734 skb_reset_network_header(frag); 735 memcpy(skb_network_header(frag), iter->tmp_hdr, hlen); 736 iter->offset += skb->len - hlen - sizeof(struct frag_hdr); 737 fh->nexthdr = iter->nexthdr; 738 fh->reserved = 0; 739 fh->frag_off = htons(iter->offset); 740 if (frag->next) 741 fh->frag_off |= htons(IP6_MF); 742 fh->identification = iter->frag_id; 743 ipv6_hdr(frag)->payload_len = htons(frag->len - sizeof(struct ipv6hdr)); 744 ip6_copy_metadata(frag, skb); 745 } 746 EXPORT_SYMBOL(ip6_fraglist_prepare); 747 748 void ip6_frag_init(struct sk_buff *skb, unsigned int hlen, unsigned int mtu, 749 unsigned short needed_tailroom, int hdr_room, u8 *prevhdr, 750 u8 nexthdr, __be32 frag_id, struct ip6_frag_state *state) 751 { 752 state->prevhdr = prevhdr; 753 state->nexthdr = nexthdr; 754 state->frag_id = frag_id; 755 756 state->hlen = hlen; 757 state->mtu = mtu; 758 759 state->left = skb->len - hlen; /* Space per frame */ 760 state->ptr = hlen; /* Where to start from */ 761 762 state->hroom = hdr_room; 763 state->troom = needed_tailroom; 764 765 state->offset = 0; 766 } 767 EXPORT_SYMBOL(ip6_frag_init); 768 769 struct sk_buff *ip6_frag_next(struct sk_buff *skb, struct ip6_frag_state *state) 770 { 771 u8 *prevhdr = state->prevhdr, *fragnexthdr_offset; 772 struct sk_buff *frag; 773 struct frag_hdr *fh; 774 unsigned int len; 775 776 len = state->left; 777 /* IF: it doesn't fit, use 'mtu' - the data space left */ 778 if (len > state->mtu) 779 len = state->mtu; 780 /* IF: we are not sending up to and including the packet end 781 then align the next start on an eight byte boundary */ 782 if (len < state->left) 783 len &= ~7; 784 785 /* Allocate buffer */ 786 frag = alloc_skb(len + state->hlen + sizeof(struct frag_hdr) + 787 state->hroom + state->troom, GFP_ATOMIC); 788 if (!frag) 789 return ERR_PTR(-ENOMEM); 790 791 /* 792 * Set up data on packet 793 */ 794 795 ip6_copy_metadata(frag, skb); 796 skb_reserve(frag, state->hroom); 797 skb_put(frag, len + state->hlen + sizeof(struct frag_hdr)); 798 skb_reset_network_header(frag); 799 fh = (struct frag_hdr *)(skb_network_header(frag) + state->hlen); 800 frag->transport_header = (frag->network_header + state->hlen + 801 sizeof(struct frag_hdr)); 802 803 /* 804 * Charge the memory for the fragment to any owner 805 * it might possess 806 */ 807 if (skb->sk) 808 skb_set_owner_w(frag, skb->sk); 809 810 /* 811 * Copy the packet header into the new buffer. 812 */ 813 skb_copy_from_linear_data(skb, skb_network_header(frag), state->hlen); 814 815 fragnexthdr_offset = skb_network_header(frag); 816 fragnexthdr_offset += prevhdr - skb_network_header(skb); 817 *fragnexthdr_offset = NEXTHDR_FRAGMENT; 818 819 /* 820 * Build fragment header. 821 */ 822 fh->nexthdr = state->nexthdr; 823 fh->reserved = 0; 824 fh->identification = state->frag_id; 825 826 /* 827 * Copy a block of the IP datagram. 828 */ 829 BUG_ON(skb_copy_bits(skb, state->ptr, skb_transport_header(frag), 830 len)); 831 state->left -= len; 832 833 fh->frag_off = htons(state->offset); 834 if (state->left > 0) 835 fh->frag_off |= htons(IP6_MF); 836 ipv6_hdr(frag)->payload_len = htons(frag->len - sizeof(struct ipv6hdr)); 837 838 state->ptr += len; 839 state->offset += len; 840 841 return frag; 842 } 843 EXPORT_SYMBOL(ip6_frag_next); 844 845 int ip6_fragment(struct net *net, struct sock *sk, struct sk_buff *skb, 846 int (*output)(struct net *, struct sock *, struct sk_buff *)) 847 { 848 struct sk_buff *frag; 849 struct rt6_info *rt = (struct rt6_info *)skb_dst(skb); 850 struct ipv6_pinfo *np = skb->sk && !dev_recursion_level() ? 851 inet6_sk(skb->sk) : NULL; 852 bool mono_delivery_time = skb->mono_delivery_time; 853 struct ip6_frag_state state; 854 unsigned int mtu, hlen, nexthdr_offset; 855 ktime_t tstamp = skb->tstamp; 856 int hroom, err = 0; 857 __be32 frag_id; 858 u8 *prevhdr, nexthdr = 0; 859 860 err = ip6_find_1stfragopt(skb, &prevhdr); 861 if (err < 0) 862 goto fail; 863 hlen = err; 864 nexthdr = *prevhdr; 865 nexthdr_offset = prevhdr - skb_network_header(skb); 866 867 mtu = ip6_skb_dst_mtu(skb); 868 869 /* We must not fragment if the socket is set to force MTU discovery 870 * or if the skb it not generated by a local socket. 871 */ 872 if (unlikely(!skb->ignore_df && skb->len > mtu)) 873 goto fail_toobig; 874 875 if (IP6CB(skb)->frag_max_size) { 876 if (IP6CB(skb)->frag_max_size > mtu) 877 goto fail_toobig; 878 879 /* don't send fragments larger than what we received */ 880 mtu = IP6CB(skb)->frag_max_size; 881 if (mtu < IPV6_MIN_MTU) 882 mtu = IPV6_MIN_MTU; 883 } 884 885 if (np && np->frag_size < mtu) { 886 if (np->frag_size) 887 mtu = np->frag_size; 888 } 889 if (mtu < hlen + sizeof(struct frag_hdr) + 8) 890 goto fail_toobig; 891 mtu -= hlen + sizeof(struct frag_hdr); 892 893 frag_id = ipv6_select_ident(net, &ipv6_hdr(skb)->daddr, 894 &ipv6_hdr(skb)->saddr); 895 896 if (skb->ip_summed == CHECKSUM_PARTIAL && 897 (err = skb_checksum_help(skb))) 898 goto fail; 899 900 prevhdr = skb_network_header(skb) + nexthdr_offset; 901 hroom = LL_RESERVED_SPACE(rt->dst.dev); 902 if (skb_has_frag_list(skb)) { 903 unsigned int first_len = skb_pagelen(skb); 904 struct ip6_fraglist_iter iter; 905 struct sk_buff *frag2; 906 907 if (first_len - hlen > mtu || 908 ((first_len - hlen) & 7) || 909 skb_cloned(skb) || 910 skb_headroom(skb) < (hroom + sizeof(struct frag_hdr))) 911 goto slow_path; 912 913 skb_walk_frags(skb, frag) { 914 /* Correct geometry. */ 915 if (frag->len > mtu || 916 ((frag->len & 7) && frag->next) || 917 skb_headroom(frag) < (hlen + hroom + sizeof(struct frag_hdr))) 918 goto slow_path_clean; 919 920 /* Partially cloned skb? */ 921 if (skb_shared(frag)) 922 goto slow_path_clean; 923 924 BUG_ON(frag->sk); 925 if (skb->sk) { 926 frag->sk = skb->sk; 927 frag->destructor = sock_wfree; 928 } 929 skb->truesize -= frag->truesize; 930 } 931 932 err = ip6_fraglist_init(skb, hlen, prevhdr, nexthdr, frag_id, 933 &iter); 934 if (err < 0) 935 goto fail; 936 937 /* We prevent @rt from being freed. */ 938 rcu_read_lock(); 939 940 for (;;) { 941 /* Prepare header of the next frame, 942 * before previous one went down. */ 943 if (iter.frag) 944 ip6_fraglist_prepare(skb, &iter); 945 946 skb_set_delivery_time(skb, tstamp, mono_delivery_time); 947 err = output(net, sk, skb); 948 if (!err) 949 IP6_INC_STATS(net, ip6_dst_idev(&rt->dst), 950 IPSTATS_MIB_FRAGCREATES); 951 952 if (err || !iter.frag) 953 break; 954 955 skb = ip6_fraglist_next(&iter); 956 } 957 958 kfree(iter.tmp_hdr); 959 960 if (err == 0) { 961 IP6_INC_STATS(net, ip6_dst_idev(&rt->dst), 962 IPSTATS_MIB_FRAGOKS); 963 rcu_read_unlock(); 964 return 0; 965 } 966 967 kfree_skb_list(iter.frag); 968 969 IP6_INC_STATS(net, ip6_dst_idev(&rt->dst), 970 IPSTATS_MIB_FRAGFAILS); 971 rcu_read_unlock(); 972 return err; 973 974 slow_path_clean: 975 skb_walk_frags(skb, frag2) { 976 if (frag2 == frag) 977 break; 978 frag2->sk = NULL; 979 frag2->destructor = NULL; 980 skb->truesize += frag2->truesize; 981 } 982 } 983 984 slow_path: 985 /* 986 * Fragment the datagram. 987 */ 988 989 ip6_frag_init(skb, hlen, mtu, rt->dst.dev->needed_tailroom, 990 LL_RESERVED_SPACE(rt->dst.dev), prevhdr, nexthdr, frag_id, 991 &state); 992 993 /* 994 * Keep copying data until we run out. 995 */ 996 997 while (state.left > 0) { 998 frag = ip6_frag_next(skb, &state); 999 if (IS_ERR(frag)) { 1000 err = PTR_ERR(frag); 1001 goto fail; 1002 } 1003 1004 /* 1005 * Put this fragment into the sending queue. 1006 */ 1007 skb_set_delivery_time(frag, tstamp, mono_delivery_time); 1008 err = output(net, sk, frag); 1009 if (err) 1010 goto fail; 1011 1012 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), 1013 IPSTATS_MIB_FRAGCREATES); 1014 } 1015 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), 1016 IPSTATS_MIB_FRAGOKS); 1017 consume_skb(skb); 1018 return err; 1019 1020 fail_toobig: 1021 if (skb->sk && dst_allfrag(skb_dst(skb))) 1022 sk_gso_disable(skb->sk); 1023 1024 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu); 1025 err = -EMSGSIZE; 1026 1027 fail: 1028 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), 1029 IPSTATS_MIB_FRAGFAILS); 1030 kfree_skb(skb); 1031 return err; 1032 } 1033 1034 static inline int ip6_rt_check(const struct rt6key *rt_key, 1035 const struct in6_addr *fl_addr, 1036 const struct in6_addr *addr_cache) 1037 { 1038 return (rt_key->plen != 128 || !ipv6_addr_equal(fl_addr, &rt_key->addr)) && 1039 (!addr_cache || !ipv6_addr_equal(fl_addr, addr_cache)); 1040 } 1041 1042 static struct dst_entry *ip6_sk_dst_check(struct sock *sk, 1043 struct dst_entry *dst, 1044 const struct flowi6 *fl6) 1045 { 1046 struct ipv6_pinfo *np = inet6_sk(sk); 1047 struct rt6_info *rt; 1048 1049 if (!dst) 1050 goto out; 1051 1052 if (dst->ops->family != AF_INET6) { 1053 dst_release(dst); 1054 return NULL; 1055 } 1056 1057 rt = (struct rt6_info *)dst; 1058 /* Yes, checking route validity in not connected 1059 * case is not very simple. Take into account, 1060 * that we do not support routing by source, TOS, 1061 * and MSG_DONTROUTE --ANK (980726) 1062 * 1063 * 1. ip6_rt_check(): If route was host route, 1064 * check that cached destination is current. 1065 * If it is network route, we still may 1066 * check its validity using saved pointer 1067 * to the last used address: daddr_cache. 1068 * We do not want to save whole address now, 1069 * (because main consumer of this service 1070 * is tcp, which has not this problem), 1071 * so that the last trick works only on connected 1072 * sockets. 1073 * 2. oif also should be the same. 1074 */ 1075 if (ip6_rt_check(&rt->rt6i_dst, &fl6->daddr, np->daddr_cache) || 1076 #ifdef CONFIG_IPV6_SUBTREES 1077 ip6_rt_check(&rt->rt6i_src, &fl6->saddr, np->saddr_cache) || 1078 #endif 1079 (fl6->flowi6_oif && fl6->flowi6_oif != dst->dev->ifindex)) { 1080 dst_release(dst); 1081 dst = NULL; 1082 } 1083 1084 out: 1085 return dst; 1086 } 1087 1088 static int ip6_dst_lookup_tail(struct net *net, const struct sock *sk, 1089 struct dst_entry **dst, struct flowi6 *fl6) 1090 { 1091 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD 1092 struct neighbour *n; 1093 struct rt6_info *rt; 1094 #endif 1095 int err; 1096 int flags = 0; 1097 1098 /* The correct way to handle this would be to do 1099 * ip6_route_get_saddr, and then ip6_route_output; however, 1100 * the route-specific preferred source forces the 1101 * ip6_route_output call _before_ ip6_route_get_saddr. 1102 * 1103 * In source specific routing (no src=any default route), 1104 * ip6_route_output will fail given src=any saddr, though, so 1105 * that's why we try it again later. 1106 */ 1107 if (ipv6_addr_any(&fl6->saddr)) { 1108 struct fib6_info *from; 1109 struct rt6_info *rt; 1110 1111 *dst = ip6_route_output(net, sk, fl6); 1112 rt = (*dst)->error ? NULL : (struct rt6_info *)*dst; 1113 1114 rcu_read_lock(); 1115 from = rt ? rcu_dereference(rt->from) : NULL; 1116 err = ip6_route_get_saddr(net, from, &fl6->daddr, 1117 sk ? inet6_sk(sk)->srcprefs : 0, 1118 &fl6->saddr); 1119 rcu_read_unlock(); 1120 1121 if (err) 1122 goto out_err_release; 1123 1124 /* If we had an erroneous initial result, pretend it 1125 * never existed and let the SA-enabled version take 1126 * over. 1127 */ 1128 if ((*dst)->error) { 1129 dst_release(*dst); 1130 *dst = NULL; 1131 } 1132 1133 if (fl6->flowi6_oif) 1134 flags |= RT6_LOOKUP_F_IFACE; 1135 } 1136 1137 if (!*dst) 1138 *dst = ip6_route_output_flags(net, sk, fl6, flags); 1139 1140 err = (*dst)->error; 1141 if (err) 1142 goto out_err_release; 1143 1144 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD 1145 /* 1146 * Here if the dst entry we've looked up 1147 * has a neighbour entry that is in the INCOMPLETE 1148 * state and the src address from the flow is 1149 * marked as OPTIMISTIC, we release the found 1150 * dst entry and replace it instead with the 1151 * dst entry of the nexthop router 1152 */ 1153 rt = (struct rt6_info *) *dst; 1154 rcu_read_lock(); 1155 n = __ipv6_neigh_lookup_noref(rt->dst.dev, 1156 rt6_nexthop(rt, &fl6->daddr)); 1157 err = n && !(READ_ONCE(n->nud_state) & NUD_VALID) ? -EINVAL : 0; 1158 rcu_read_unlock(); 1159 1160 if (err) { 1161 struct inet6_ifaddr *ifp; 1162 struct flowi6 fl_gw6; 1163 int redirect; 1164 1165 ifp = ipv6_get_ifaddr(net, &fl6->saddr, 1166 (*dst)->dev, 1); 1167 1168 redirect = (ifp && ifp->flags & IFA_F_OPTIMISTIC); 1169 if (ifp) 1170 in6_ifa_put(ifp); 1171 1172 if (redirect) { 1173 /* 1174 * We need to get the dst entry for the 1175 * default router instead 1176 */ 1177 dst_release(*dst); 1178 memcpy(&fl_gw6, fl6, sizeof(struct flowi6)); 1179 memset(&fl_gw6.daddr, 0, sizeof(struct in6_addr)); 1180 *dst = ip6_route_output(net, sk, &fl_gw6); 1181 err = (*dst)->error; 1182 if (err) 1183 goto out_err_release; 1184 } 1185 } 1186 #endif 1187 if (ipv6_addr_v4mapped(&fl6->saddr) && 1188 !(ipv6_addr_v4mapped(&fl6->daddr) || ipv6_addr_any(&fl6->daddr))) { 1189 err = -EAFNOSUPPORT; 1190 goto out_err_release; 1191 } 1192 1193 return 0; 1194 1195 out_err_release: 1196 dst_release(*dst); 1197 *dst = NULL; 1198 1199 if (err == -ENETUNREACH) 1200 IP6_INC_STATS(net, NULL, IPSTATS_MIB_OUTNOROUTES); 1201 return err; 1202 } 1203 1204 /** 1205 * ip6_dst_lookup - perform route lookup on flow 1206 * @net: Network namespace to perform lookup in 1207 * @sk: socket which provides route info 1208 * @dst: pointer to dst_entry * for result 1209 * @fl6: flow to lookup 1210 * 1211 * This function performs a route lookup on the given flow. 1212 * 1213 * It returns zero on success, or a standard errno code on error. 1214 */ 1215 int ip6_dst_lookup(struct net *net, struct sock *sk, struct dst_entry **dst, 1216 struct flowi6 *fl6) 1217 { 1218 *dst = NULL; 1219 return ip6_dst_lookup_tail(net, sk, dst, fl6); 1220 } 1221 EXPORT_SYMBOL_GPL(ip6_dst_lookup); 1222 1223 /** 1224 * ip6_dst_lookup_flow - perform route lookup on flow with ipsec 1225 * @net: Network namespace to perform lookup in 1226 * @sk: socket which provides route info 1227 * @fl6: flow to lookup 1228 * @final_dst: final destination address for ipsec lookup 1229 * 1230 * This function performs a route lookup on the given flow. 1231 * 1232 * It returns a valid dst pointer on success, or a pointer encoded 1233 * error code. 1234 */ 1235 struct dst_entry *ip6_dst_lookup_flow(struct net *net, const struct sock *sk, struct flowi6 *fl6, 1236 const struct in6_addr *final_dst) 1237 { 1238 struct dst_entry *dst = NULL; 1239 int err; 1240 1241 err = ip6_dst_lookup_tail(net, sk, &dst, fl6); 1242 if (err) 1243 return ERR_PTR(err); 1244 if (final_dst) 1245 fl6->daddr = *final_dst; 1246 1247 return xfrm_lookup_route(net, dst, flowi6_to_flowi(fl6), sk, 0); 1248 } 1249 EXPORT_SYMBOL_GPL(ip6_dst_lookup_flow); 1250 1251 /** 1252 * ip6_sk_dst_lookup_flow - perform socket cached route lookup on flow 1253 * @sk: socket which provides the dst cache and route info 1254 * @fl6: flow to lookup 1255 * @final_dst: final destination address for ipsec lookup 1256 * @connected: whether @sk is connected or not 1257 * 1258 * This function performs a route lookup on the given flow with the 1259 * possibility of using the cached route in the socket if it is valid. 1260 * It will take the socket dst lock when operating on the dst cache. 1261 * As a result, this function can only be used in process context. 1262 * 1263 * In addition, for a connected socket, cache the dst in the socket 1264 * if the current cache is not valid. 1265 * 1266 * It returns a valid dst pointer on success, or a pointer encoded 1267 * error code. 1268 */ 1269 struct dst_entry *ip6_sk_dst_lookup_flow(struct sock *sk, struct flowi6 *fl6, 1270 const struct in6_addr *final_dst, 1271 bool connected) 1272 { 1273 struct dst_entry *dst = sk_dst_check(sk, inet6_sk(sk)->dst_cookie); 1274 1275 dst = ip6_sk_dst_check(sk, dst, fl6); 1276 if (dst) 1277 return dst; 1278 1279 dst = ip6_dst_lookup_flow(sock_net(sk), sk, fl6, final_dst); 1280 if (connected && !IS_ERR(dst)) 1281 ip6_sk_dst_store_flow(sk, dst_clone(dst), fl6); 1282 1283 return dst; 1284 } 1285 EXPORT_SYMBOL_GPL(ip6_sk_dst_lookup_flow); 1286 1287 /** 1288 * ip6_dst_lookup_tunnel - perform route lookup on tunnel 1289 * @skb: Packet for which lookup is done 1290 * @dev: Tunnel device 1291 * @net: Network namespace of tunnel device 1292 * @sock: Socket which provides route info 1293 * @saddr: Memory to store the src ip address 1294 * @info: Tunnel information 1295 * @protocol: IP protocol 1296 * @use_cache: Flag to enable cache usage 1297 * This function performs a route lookup on a tunnel 1298 * 1299 * It returns a valid dst pointer and stores src address to be used in 1300 * tunnel in param saddr on success, else a pointer encoded error code. 1301 */ 1302 1303 struct dst_entry *ip6_dst_lookup_tunnel(struct sk_buff *skb, 1304 struct net_device *dev, 1305 struct net *net, 1306 struct socket *sock, 1307 struct in6_addr *saddr, 1308 const struct ip_tunnel_info *info, 1309 u8 protocol, 1310 bool use_cache) 1311 { 1312 struct dst_entry *dst = NULL; 1313 #ifdef CONFIG_DST_CACHE 1314 struct dst_cache *dst_cache; 1315 #endif 1316 struct flowi6 fl6; 1317 __u8 prio; 1318 1319 #ifdef CONFIG_DST_CACHE 1320 dst_cache = (struct dst_cache *)&info->dst_cache; 1321 if (use_cache) { 1322 dst = dst_cache_get_ip6(dst_cache, saddr); 1323 if (dst) 1324 return dst; 1325 } 1326 #endif 1327 memset(&fl6, 0, sizeof(fl6)); 1328 fl6.flowi6_mark = skb->mark; 1329 fl6.flowi6_proto = protocol; 1330 fl6.daddr = info->key.u.ipv6.dst; 1331 fl6.saddr = info->key.u.ipv6.src; 1332 prio = info->key.tos; 1333 fl6.flowlabel = ip6_make_flowinfo(prio, info->key.label); 1334 1335 dst = ipv6_stub->ipv6_dst_lookup_flow(net, sock->sk, &fl6, 1336 NULL); 1337 if (IS_ERR(dst)) { 1338 netdev_dbg(dev, "no route to %pI6\n", &fl6.daddr); 1339 return ERR_PTR(-ENETUNREACH); 1340 } 1341 if (dst->dev == dev) { /* is this necessary? */ 1342 netdev_dbg(dev, "circular route to %pI6\n", &fl6.daddr); 1343 dst_release(dst); 1344 return ERR_PTR(-ELOOP); 1345 } 1346 #ifdef CONFIG_DST_CACHE 1347 if (use_cache) 1348 dst_cache_set_ip6(dst_cache, dst, &fl6.saddr); 1349 #endif 1350 *saddr = fl6.saddr; 1351 return dst; 1352 } 1353 EXPORT_SYMBOL_GPL(ip6_dst_lookup_tunnel); 1354 1355 static inline struct ipv6_opt_hdr *ip6_opt_dup(struct ipv6_opt_hdr *src, 1356 gfp_t gfp) 1357 { 1358 return src ? kmemdup(src, (src->hdrlen + 1) * 8, gfp) : NULL; 1359 } 1360 1361 static inline struct ipv6_rt_hdr *ip6_rthdr_dup(struct ipv6_rt_hdr *src, 1362 gfp_t gfp) 1363 { 1364 return src ? kmemdup(src, (src->hdrlen + 1) * 8, gfp) : NULL; 1365 } 1366 1367 static void ip6_append_data_mtu(unsigned int *mtu, 1368 int *maxfraglen, 1369 unsigned int fragheaderlen, 1370 struct sk_buff *skb, 1371 struct rt6_info *rt, 1372 unsigned int orig_mtu) 1373 { 1374 if (!(rt->dst.flags & DST_XFRM_TUNNEL)) { 1375 if (!skb) { 1376 /* first fragment, reserve header_len */ 1377 *mtu = orig_mtu - rt->dst.header_len; 1378 1379 } else { 1380 /* 1381 * this fragment is not first, the headers 1382 * space is regarded as data space. 1383 */ 1384 *mtu = orig_mtu; 1385 } 1386 *maxfraglen = ((*mtu - fragheaderlen) & ~7) 1387 + fragheaderlen - sizeof(struct frag_hdr); 1388 } 1389 } 1390 1391 static int ip6_setup_cork(struct sock *sk, struct inet_cork_full *cork, 1392 struct inet6_cork *v6_cork, struct ipcm6_cookie *ipc6, 1393 struct rt6_info *rt) 1394 { 1395 struct ipv6_pinfo *np = inet6_sk(sk); 1396 unsigned int mtu; 1397 struct ipv6_txoptions *nopt, *opt = ipc6->opt; 1398 1399 /* callers pass dst together with a reference, set it first so 1400 * ip6_cork_release() can put it down even in case of an error. 1401 */ 1402 cork->base.dst = &rt->dst; 1403 1404 /* 1405 * setup for corking 1406 */ 1407 if (opt) { 1408 if (WARN_ON(v6_cork->opt)) 1409 return -EINVAL; 1410 1411 nopt = v6_cork->opt = kzalloc(sizeof(*opt), sk->sk_allocation); 1412 if (unlikely(!nopt)) 1413 return -ENOBUFS; 1414 1415 nopt->tot_len = sizeof(*opt); 1416 nopt->opt_flen = opt->opt_flen; 1417 nopt->opt_nflen = opt->opt_nflen; 1418 1419 nopt->dst0opt = ip6_opt_dup(opt->dst0opt, sk->sk_allocation); 1420 if (opt->dst0opt && !nopt->dst0opt) 1421 return -ENOBUFS; 1422 1423 nopt->dst1opt = ip6_opt_dup(opt->dst1opt, sk->sk_allocation); 1424 if (opt->dst1opt && !nopt->dst1opt) 1425 return -ENOBUFS; 1426 1427 nopt->hopopt = ip6_opt_dup(opt->hopopt, sk->sk_allocation); 1428 if (opt->hopopt && !nopt->hopopt) 1429 return -ENOBUFS; 1430 1431 nopt->srcrt = ip6_rthdr_dup(opt->srcrt, sk->sk_allocation); 1432 if (opt->srcrt && !nopt->srcrt) 1433 return -ENOBUFS; 1434 1435 /* need source address above miyazawa*/ 1436 } 1437 v6_cork->hop_limit = ipc6->hlimit; 1438 v6_cork->tclass = ipc6->tclass; 1439 if (rt->dst.flags & DST_XFRM_TUNNEL) 1440 mtu = np->pmtudisc >= IPV6_PMTUDISC_PROBE ? 1441 READ_ONCE(rt->dst.dev->mtu) : dst_mtu(&rt->dst); 1442 else 1443 mtu = np->pmtudisc >= IPV6_PMTUDISC_PROBE ? 1444 READ_ONCE(rt->dst.dev->mtu) : dst_mtu(xfrm_dst_path(&rt->dst)); 1445 if (np->frag_size < mtu) { 1446 if (np->frag_size) 1447 mtu = np->frag_size; 1448 } 1449 cork->base.fragsize = mtu; 1450 cork->base.gso_size = ipc6->gso_size; 1451 cork->base.tx_flags = 0; 1452 cork->base.mark = ipc6->sockc.mark; 1453 sock_tx_timestamp(sk, ipc6->sockc.tsflags, &cork->base.tx_flags); 1454 1455 if (dst_allfrag(xfrm_dst_path(&rt->dst))) 1456 cork->base.flags |= IPCORK_ALLFRAG; 1457 cork->base.length = 0; 1458 1459 cork->base.transmit_time = ipc6->sockc.transmit_time; 1460 1461 return 0; 1462 } 1463 1464 static int __ip6_append_data(struct sock *sk, 1465 struct sk_buff_head *queue, 1466 struct inet_cork_full *cork_full, 1467 struct inet6_cork *v6_cork, 1468 struct page_frag *pfrag, 1469 int getfrag(void *from, char *to, int offset, 1470 int len, int odd, struct sk_buff *skb), 1471 void *from, size_t length, int transhdrlen, 1472 unsigned int flags, struct ipcm6_cookie *ipc6) 1473 { 1474 struct sk_buff *skb, *skb_prev = NULL; 1475 struct inet_cork *cork = &cork_full->base; 1476 struct flowi6 *fl6 = &cork_full->fl.u.ip6; 1477 unsigned int maxfraglen, fragheaderlen, mtu, orig_mtu, pmtu; 1478 struct ubuf_info *uarg = NULL; 1479 int exthdrlen = 0; 1480 int dst_exthdrlen = 0; 1481 int hh_len; 1482 int copy; 1483 int err; 1484 int offset = 0; 1485 bool zc = false; 1486 u32 tskey = 0; 1487 struct rt6_info *rt = (struct rt6_info *)cork->dst; 1488 struct ipv6_txoptions *opt = v6_cork->opt; 1489 int csummode = CHECKSUM_NONE; 1490 unsigned int maxnonfragsize, headersize; 1491 unsigned int wmem_alloc_delta = 0; 1492 bool paged, extra_uref = false; 1493 1494 skb = skb_peek_tail(queue); 1495 if (!skb) { 1496 exthdrlen = opt ? opt->opt_flen : 0; 1497 dst_exthdrlen = rt->dst.header_len - rt->rt6i_nfheader_len; 1498 } 1499 1500 paged = !!cork->gso_size; 1501 mtu = cork->gso_size ? IP6_MAX_MTU : cork->fragsize; 1502 orig_mtu = mtu; 1503 1504 if (cork->tx_flags & SKBTX_ANY_TSTAMP && 1505 sk->sk_tsflags & SOF_TIMESTAMPING_OPT_ID) 1506 tskey = atomic_inc_return(&sk->sk_tskey) - 1; 1507 1508 hh_len = LL_RESERVED_SPACE(rt->dst.dev); 1509 1510 fragheaderlen = sizeof(struct ipv6hdr) + rt->rt6i_nfheader_len + 1511 (opt ? opt->opt_nflen : 0); 1512 1513 headersize = sizeof(struct ipv6hdr) + 1514 (opt ? opt->opt_flen + opt->opt_nflen : 0) + 1515 (dst_allfrag(&rt->dst) ? 1516 sizeof(struct frag_hdr) : 0) + 1517 rt->rt6i_nfheader_len; 1518 1519 if (mtu <= fragheaderlen || 1520 ((mtu - fragheaderlen) & ~7) + fragheaderlen <= sizeof(struct frag_hdr)) 1521 goto emsgsize; 1522 1523 maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen - 1524 sizeof(struct frag_hdr); 1525 1526 /* as per RFC 7112 section 5, the entire IPv6 Header Chain must fit 1527 * the first fragment 1528 */ 1529 if (headersize + transhdrlen > mtu) 1530 goto emsgsize; 1531 1532 if (cork->length + length > mtu - headersize && ipc6->dontfrag && 1533 (sk->sk_protocol == IPPROTO_UDP || 1534 sk->sk_protocol == IPPROTO_ICMPV6 || 1535 sk->sk_protocol == IPPROTO_RAW)) { 1536 ipv6_local_rxpmtu(sk, fl6, mtu - headersize + 1537 sizeof(struct ipv6hdr)); 1538 goto emsgsize; 1539 } 1540 1541 if (ip6_sk_ignore_df(sk)) 1542 maxnonfragsize = sizeof(struct ipv6hdr) + IPV6_MAXPLEN; 1543 else 1544 maxnonfragsize = mtu; 1545 1546 if (cork->length + length > maxnonfragsize - headersize) { 1547 emsgsize: 1548 pmtu = max_t(int, mtu - headersize + sizeof(struct ipv6hdr), 0); 1549 ipv6_local_error(sk, EMSGSIZE, fl6, pmtu); 1550 return -EMSGSIZE; 1551 } 1552 1553 /* CHECKSUM_PARTIAL only with no extension headers and when 1554 * we are not going to fragment 1555 */ 1556 if (transhdrlen && sk->sk_protocol == IPPROTO_UDP && 1557 headersize == sizeof(struct ipv6hdr) && 1558 length <= mtu - headersize && 1559 (!(flags & MSG_MORE) || cork->gso_size) && 1560 rt->dst.dev->features & (NETIF_F_IPV6_CSUM | NETIF_F_HW_CSUM)) 1561 csummode = CHECKSUM_PARTIAL; 1562 1563 if ((flags & MSG_ZEROCOPY) && length) { 1564 struct msghdr *msg = from; 1565 1566 if (getfrag == ip_generic_getfrag && msg->msg_ubuf) { 1567 if (skb_zcopy(skb) && msg->msg_ubuf != skb_zcopy(skb)) 1568 return -EINVAL; 1569 1570 /* Leave uarg NULL if can't zerocopy, callers should 1571 * be able to handle it. 1572 */ 1573 if ((rt->dst.dev->features & NETIF_F_SG) && 1574 csummode == CHECKSUM_PARTIAL) { 1575 paged = true; 1576 zc = true; 1577 uarg = msg->msg_ubuf; 1578 } 1579 } else if (sock_flag(sk, SOCK_ZEROCOPY)) { 1580 uarg = msg_zerocopy_realloc(sk, length, skb_zcopy(skb)); 1581 if (!uarg) 1582 return -ENOBUFS; 1583 extra_uref = !skb_zcopy(skb); /* only ref on new uarg */ 1584 if (rt->dst.dev->features & NETIF_F_SG && 1585 csummode == CHECKSUM_PARTIAL) { 1586 paged = true; 1587 zc = true; 1588 } else { 1589 uarg_to_msgzc(uarg)->zerocopy = 0; 1590 skb_zcopy_set(skb, uarg, &extra_uref); 1591 } 1592 } 1593 } else if ((flags & MSG_SPLICE_PAGES) && length) { 1594 if (inet_sk(sk)->hdrincl) 1595 return -EPERM; 1596 if (rt->dst.dev->features & NETIF_F_SG && 1597 getfrag == ip_generic_getfrag) 1598 /* We need an empty buffer to attach stuff to */ 1599 paged = true; 1600 else 1601 flags &= ~MSG_SPLICE_PAGES; 1602 } 1603 1604 /* 1605 * Let's try using as much space as possible. 1606 * Use MTU if total length of the message fits into the MTU. 1607 * Otherwise, we need to reserve fragment header and 1608 * fragment alignment (= 8-15 octects, in total). 1609 * 1610 * Note that we may need to "move" the data from the tail 1611 * of the buffer to the new fragment when we split 1612 * the message. 1613 * 1614 * FIXME: It may be fragmented into multiple chunks 1615 * at once if non-fragmentable extension headers 1616 * are too large. 1617 * --yoshfuji 1618 */ 1619 1620 cork->length += length; 1621 if (!skb) 1622 goto alloc_new_skb; 1623 1624 while (length > 0) { 1625 /* Check if the remaining data fits into current packet. */ 1626 copy = (cork->length <= mtu && !(cork->flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - skb->len; 1627 if (copy < length) 1628 copy = maxfraglen - skb->len; 1629 1630 if (copy <= 0) { 1631 char *data; 1632 unsigned int datalen; 1633 unsigned int fraglen; 1634 unsigned int fraggap; 1635 unsigned int alloclen, alloc_extra; 1636 unsigned int pagedlen; 1637 alloc_new_skb: 1638 /* There's no room in the current skb */ 1639 if (skb) 1640 fraggap = skb->len - maxfraglen; 1641 else 1642 fraggap = 0; 1643 /* update mtu and maxfraglen if necessary */ 1644 if (!skb || !skb_prev) 1645 ip6_append_data_mtu(&mtu, &maxfraglen, 1646 fragheaderlen, skb, rt, 1647 orig_mtu); 1648 1649 skb_prev = skb; 1650 1651 /* 1652 * If remaining data exceeds the mtu, 1653 * we know we need more fragment(s). 1654 */ 1655 datalen = length + fraggap; 1656 1657 if (datalen > (cork->length <= mtu && !(cork->flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - fragheaderlen) 1658 datalen = maxfraglen - fragheaderlen - rt->dst.trailer_len; 1659 fraglen = datalen + fragheaderlen; 1660 pagedlen = 0; 1661 1662 alloc_extra = hh_len; 1663 alloc_extra += dst_exthdrlen; 1664 alloc_extra += rt->dst.trailer_len; 1665 1666 /* We just reserve space for fragment header. 1667 * Note: this may be overallocation if the message 1668 * (without MSG_MORE) fits into the MTU. 1669 */ 1670 alloc_extra += sizeof(struct frag_hdr); 1671 1672 if ((flags & MSG_MORE) && 1673 !(rt->dst.dev->features&NETIF_F_SG)) 1674 alloclen = mtu; 1675 else if (!paged && 1676 (fraglen + alloc_extra < SKB_MAX_ALLOC || 1677 !(rt->dst.dev->features & NETIF_F_SG))) 1678 alloclen = fraglen; 1679 else { 1680 alloclen = fragheaderlen + transhdrlen; 1681 pagedlen = datalen - transhdrlen; 1682 } 1683 alloclen += alloc_extra; 1684 1685 if (datalen != length + fraggap) { 1686 /* 1687 * this is not the last fragment, the trailer 1688 * space is regarded as data space. 1689 */ 1690 datalen += rt->dst.trailer_len; 1691 } 1692 1693 fraglen = datalen + fragheaderlen; 1694 1695 copy = datalen - transhdrlen - fraggap - pagedlen; 1696 if (copy < 0) { 1697 err = -EINVAL; 1698 goto error; 1699 } 1700 if (transhdrlen) { 1701 skb = sock_alloc_send_skb(sk, alloclen, 1702 (flags & MSG_DONTWAIT), &err); 1703 } else { 1704 skb = NULL; 1705 if (refcount_read(&sk->sk_wmem_alloc) + wmem_alloc_delta <= 1706 2 * sk->sk_sndbuf) 1707 skb = alloc_skb(alloclen, 1708 sk->sk_allocation); 1709 if (unlikely(!skb)) 1710 err = -ENOBUFS; 1711 } 1712 if (!skb) 1713 goto error; 1714 /* 1715 * Fill in the control structures 1716 */ 1717 skb->protocol = htons(ETH_P_IPV6); 1718 skb->ip_summed = csummode; 1719 skb->csum = 0; 1720 /* reserve for fragmentation and ipsec header */ 1721 skb_reserve(skb, hh_len + sizeof(struct frag_hdr) + 1722 dst_exthdrlen); 1723 1724 /* 1725 * Find where to start putting bytes 1726 */ 1727 data = skb_put(skb, fraglen - pagedlen); 1728 skb_set_network_header(skb, exthdrlen); 1729 data += fragheaderlen; 1730 skb->transport_header = (skb->network_header + 1731 fragheaderlen); 1732 if (fraggap) { 1733 skb->csum = skb_copy_and_csum_bits( 1734 skb_prev, maxfraglen, 1735 data + transhdrlen, fraggap); 1736 skb_prev->csum = csum_sub(skb_prev->csum, 1737 skb->csum); 1738 data += fraggap; 1739 pskb_trim_unique(skb_prev, maxfraglen); 1740 } 1741 if (copy > 0 && 1742 getfrag(from, data + transhdrlen, offset, 1743 copy, fraggap, skb) < 0) { 1744 err = -EFAULT; 1745 kfree_skb(skb); 1746 goto error; 1747 } 1748 1749 offset += copy; 1750 length -= copy + transhdrlen; 1751 transhdrlen = 0; 1752 exthdrlen = 0; 1753 dst_exthdrlen = 0; 1754 1755 /* Only the initial fragment is time stamped */ 1756 skb_shinfo(skb)->tx_flags = cork->tx_flags; 1757 cork->tx_flags = 0; 1758 skb_shinfo(skb)->tskey = tskey; 1759 tskey = 0; 1760 skb_zcopy_set(skb, uarg, &extra_uref); 1761 1762 if ((flags & MSG_CONFIRM) && !skb_prev) 1763 skb_set_dst_pending_confirm(skb, 1); 1764 1765 /* 1766 * Put the packet on the pending queue 1767 */ 1768 if (!skb->destructor) { 1769 skb->destructor = sock_wfree; 1770 skb->sk = sk; 1771 wmem_alloc_delta += skb->truesize; 1772 } 1773 __skb_queue_tail(queue, skb); 1774 continue; 1775 } 1776 1777 if (copy > length) 1778 copy = length; 1779 1780 if (!(rt->dst.dev->features&NETIF_F_SG) && 1781 skb_tailroom(skb) >= copy) { 1782 unsigned int off; 1783 1784 off = skb->len; 1785 if (getfrag(from, skb_put(skb, copy), 1786 offset, copy, off, skb) < 0) { 1787 __skb_trim(skb, off); 1788 err = -EFAULT; 1789 goto error; 1790 } 1791 } else if (flags & MSG_SPLICE_PAGES) { 1792 struct msghdr *msg = from; 1793 1794 err = skb_splice_from_iter(skb, &msg->msg_iter, copy, 1795 sk->sk_allocation); 1796 if (err < 0) 1797 goto error; 1798 copy = err; 1799 wmem_alloc_delta += copy; 1800 } else if (!zc) { 1801 int i = skb_shinfo(skb)->nr_frags; 1802 1803 err = -ENOMEM; 1804 if (!sk_page_frag_refill(sk, pfrag)) 1805 goto error; 1806 1807 skb_zcopy_downgrade_managed(skb); 1808 if (!skb_can_coalesce(skb, i, pfrag->page, 1809 pfrag->offset)) { 1810 err = -EMSGSIZE; 1811 if (i == MAX_SKB_FRAGS) 1812 goto error; 1813 1814 __skb_fill_page_desc(skb, i, pfrag->page, 1815 pfrag->offset, 0); 1816 skb_shinfo(skb)->nr_frags = ++i; 1817 get_page(pfrag->page); 1818 } 1819 copy = min_t(int, copy, pfrag->size - pfrag->offset); 1820 if (getfrag(from, 1821 page_address(pfrag->page) + pfrag->offset, 1822 offset, copy, skb->len, skb) < 0) 1823 goto error_efault; 1824 1825 pfrag->offset += copy; 1826 skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], copy); 1827 skb->len += copy; 1828 skb->data_len += copy; 1829 skb->truesize += copy; 1830 wmem_alloc_delta += copy; 1831 } else { 1832 err = skb_zerocopy_iter_dgram(skb, from, copy); 1833 if (err < 0) 1834 goto error; 1835 } 1836 offset += copy; 1837 length -= copy; 1838 } 1839 1840 if (wmem_alloc_delta) 1841 refcount_add(wmem_alloc_delta, &sk->sk_wmem_alloc); 1842 return 0; 1843 1844 error_efault: 1845 err = -EFAULT; 1846 error: 1847 net_zcopy_put_abort(uarg, extra_uref); 1848 cork->length -= length; 1849 IP6_INC_STATS(sock_net(sk), rt->rt6i_idev, IPSTATS_MIB_OUTDISCARDS); 1850 refcount_add(wmem_alloc_delta, &sk->sk_wmem_alloc); 1851 return err; 1852 } 1853 1854 int ip6_append_data(struct sock *sk, 1855 int getfrag(void *from, char *to, int offset, int len, 1856 int odd, struct sk_buff *skb), 1857 void *from, size_t length, int transhdrlen, 1858 struct ipcm6_cookie *ipc6, struct flowi6 *fl6, 1859 struct rt6_info *rt, unsigned int flags) 1860 { 1861 struct inet_sock *inet = inet_sk(sk); 1862 struct ipv6_pinfo *np = inet6_sk(sk); 1863 int exthdrlen; 1864 int err; 1865 1866 if (flags&MSG_PROBE) 1867 return 0; 1868 if (skb_queue_empty(&sk->sk_write_queue)) { 1869 /* 1870 * setup for corking 1871 */ 1872 dst_hold(&rt->dst); 1873 err = ip6_setup_cork(sk, &inet->cork, &np->cork, 1874 ipc6, rt); 1875 if (err) 1876 return err; 1877 1878 inet->cork.fl.u.ip6 = *fl6; 1879 exthdrlen = (ipc6->opt ? ipc6->opt->opt_flen : 0); 1880 length += exthdrlen; 1881 transhdrlen += exthdrlen; 1882 } else { 1883 transhdrlen = 0; 1884 } 1885 1886 return __ip6_append_data(sk, &sk->sk_write_queue, &inet->cork, 1887 &np->cork, sk_page_frag(sk), getfrag, 1888 from, length, transhdrlen, flags, ipc6); 1889 } 1890 EXPORT_SYMBOL_GPL(ip6_append_data); 1891 1892 static void ip6_cork_steal_dst(struct sk_buff *skb, struct inet_cork_full *cork) 1893 { 1894 struct dst_entry *dst = cork->base.dst; 1895 1896 cork->base.dst = NULL; 1897 cork->base.flags &= ~IPCORK_ALLFRAG; 1898 skb_dst_set(skb, dst); 1899 } 1900 1901 static void ip6_cork_release(struct inet_cork_full *cork, 1902 struct inet6_cork *v6_cork) 1903 { 1904 if (v6_cork->opt) { 1905 struct ipv6_txoptions *opt = v6_cork->opt; 1906 1907 kfree(opt->dst0opt); 1908 kfree(opt->dst1opt); 1909 kfree(opt->hopopt); 1910 kfree(opt->srcrt); 1911 kfree(opt); 1912 v6_cork->opt = NULL; 1913 } 1914 1915 if (cork->base.dst) { 1916 dst_release(cork->base.dst); 1917 cork->base.dst = NULL; 1918 cork->base.flags &= ~IPCORK_ALLFRAG; 1919 } 1920 } 1921 1922 struct sk_buff *__ip6_make_skb(struct sock *sk, 1923 struct sk_buff_head *queue, 1924 struct inet_cork_full *cork, 1925 struct inet6_cork *v6_cork) 1926 { 1927 struct sk_buff *skb, *tmp_skb; 1928 struct sk_buff **tail_skb; 1929 struct in6_addr *final_dst; 1930 struct ipv6_pinfo *np = inet6_sk(sk); 1931 struct net *net = sock_net(sk); 1932 struct ipv6hdr *hdr; 1933 struct ipv6_txoptions *opt = v6_cork->opt; 1934 struct rt6_info *rt = (struct rt6_info *)cork->base.dst; 1935 struct flowi6 *fl6 = &cork->fl.u.ip6; 1936 unsigned char proto = fl6->flowi6_proto; 1937 1938 skb = __skb_dequeue(queue); 1939 if (!skb) 1940 goto out; 1941 tail_skb = &(skb_shinfo(skb)->frag_list); 1942 1943 /* move skb->data to ip header from ext header */ 1944 if (skb->data < skb_network_header(skb)) 1945 __skb_pull(skb, skb_network_offset(skb)); 1946 while ((tmp_skb = __skb_dequeue(queue)) != NULL) { 1947 __skb_pull(tmp_skb, skb_network_header_len(skb)); 1948 *tail_skb = tmp_skb; 1949 tail_skb = &(tmp_skb->next); 1950 skb->len += tmp_skb->len; 1951 skb->data_len += tmp_skb->len; 1952 skb->truesize += tmp_skb->truesize; 1953 tmp_skb->destructor = NULL; 1954 tmp_skb->sk = NULL; 1955 } 1956 1957 /* Allow local fragmentation. */ 1958 skb->ignore_df = ip6_sk_ignore_df(sk); 1959 __skb_pull(skb, skb_network_header_len(skb)); 1960 1961 final_dst = &fl6->daddr; 1962 if (opt && opt->opt_flen) 1963 ipv6_push_frag_opts(skb, opt, &proto); 1964 if (opt && opt->opt_nflen) 1965 ipv6_push_nfrag_opts(skb, opt, &proto, &final_dst, &fl6->saddr); 1966 1967 skb_push(skb, sizeof(struct ipv6hdr)); 1968 skb_reset_network_header(skb); 1969 hdr = ipv6_hdr(skb); 1970 1971 ip6_flow_hdr(hdr, v6_cork->tclass, 1972 ip6_make_flowlabel(net, skb, fl6->flowlabel, 1973 ip6_autoflowlabel(net, np), fl6)); 1974 hdr->hop_limit = v6_cork->hop_limit; 1975 hdr->nexthdr = proto; 1976 hdr->saddr = fl6->saddr; 1977 hdr->daddr = *final_dst; 1978 1979 skb->priority = sk->sk_priority; 1980 skb->mark = cork->base.mark; 1981 skb->tstamp = cork->base.transmit_time; 1982 1983 ip6_cork_steal_dst(skb, cork); 1984 IP6_UPD_PO_STATS(net, rt->rt6i_idev, IPSTATS_MIB_OUT, skb->len); 1985 if (proto == IPPROTO_ICMPV6) { 1986 struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb)); 1987 u8 icmp6_type; 1988 1989 if (sk->sk_socket->type == SOCK_RAW && !inet_sk(sk)->hdrincl) 1990 icmp6_type = fl6->fl6_icmp_type; 1991 else 1992 icmp6_type = icmp6_hdr(skb)->icmp6_type; 1993 ICMP6MSGOUT_INC_STATS(net, idev, icmp6_type); 1994 ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTMSGS); 1995 } 1996 1997 ip6_cork_release(cork, v6_cork); 1998 out: 1999 return skb; 2000 } 2001 2002 int ip6_send_skb(struct sk_buff *skb) 2003 { 2004 struct net *net = sock_net(skb->sk); 2005 struct rt6_info *rt = (struct rt6_info *)skb_dst(skb); 2006 int err; 2007 2008 err = ip6_local_out(net, skb->sk, skb); 2009 if (err) { 2010 if (err > 0) 2011 err = net_xmit_errno(err); 2012 if (err) 2013 IP6_INC_STATS(net, rt->rt6i_idev, 2014 IPSTATS_MIB_OUTDISCARDS); 2015 } 2016 2017 return err; 2018 } 2019 2020 int ip6_push_pending_frames(struct sock *sk) 2021 { 2022 struct sk_buff *skb; 2023 2024 skb = ip6_finish_skb(sk); 2025 if (!skb) 2026 return 0; 2027 2028 return ip6_send_skb(skb); 2029 } 2030 EXPORT_SYMBOL_GPL(ip6_push_pending_frames); 2031 2032 static void __ip6_flush_pending_frames(struct sock *sk, 2033 struct sk_buff_head *queue, 2034 struct inet_cork_full *cork, 2035 struct inet6_cork *v6_cork) 2036 { 2037 struct sk_buff *skb; 2038 2039 while ((skb = __skb_dequeue_tail(queue)) != NULL) { 2040 if (skb_dst(skb)) 2041 IP6_INC_STATS(sock_net(sk), ip6_dst_idev(skb_dst(skb)), 2042 IPSTATS_MIB_OUTDISCARDS); 2043 kfree_skb(skb); 2044 } 2045 2046 ip6_cork_release(cork, v6_cork); 2047 } 2048 2049 void ip6_flush_pending_frames(struct sock *sk) 2050 { 2051 __ip6_flush_pending_frames(sk, &sk->sk_write_queue, 2052 &inet_sk(sk)->cork, &inet6_sk(sk)->cork); 2053 } 2054 EXPORT_SYMBOL_GPL(ip6_flush_pending_frames); 2055 2056 struct sk_buff *ip6_make_skb(struct sock *sk, 2057 int getfrag(void *from, char *to, int offset, 2058 int len, int odd, struct sk_buff *skb), 2059 void *from, size_t length, int transhdrlen, 2060 struct ipcm6_cookie *ipc6, struct rt6_info *rt, 2061 unsigned int flags, struct inet_cork_full *cork) 2062 { 2063 struct inet6_cork v6_cork; 2064 struct sk_buff_head queue; 2065 int exthdrlen = (ipc6->opt ? ipc6->opt->opt_flen : 0); 2066 int err; 2067 2068 if (flags & MSG_PROBE) { 2069 dst_release(&rt->dst); 2070 return NULL; 2071 } 2072 2073 __skb_queue_head_init(&queue); 2074 2075 cork->base.flags = 0; 2076 cork->base.addr = 0; 2077 cork->base.opt = NULL; 2078 v6_cork.opt = NULL; 2079 err = ip6_setup_cork(sk, cork, &v6_cork, ipc6, rt); 2080 if (err) { 2081 ip6_cork_release(cork, &v6_cork); 2082 return ERR_PTR(err); 2083 } 2084 if (ipc6->dontfrag < 0) 2085 ipc6->dontfrag = inet6_sk(sk)->dontfrag; 2086 2087 err = __ip6_append_data(sk, &queue, cork, &v6_cork, 2088 ¤t->task_frag, getfrag, from, 2089 length + exthdrlen, transhdrlen + exthdrlen, 2090 flags, ipc6); 2091 if (err) { 2092 __ip6_flush_pending_frames(sk, &queue, cork, &v6_cork); 2093 return ERR_PTR(err); 2094 } 2095 2096 return __ip6_make_skb(sk, &queue, cork, &v6_cork); 2097 } 2098