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 hdr->hop_limit--; 551 return ip6_input(skb); 552 } else if (proxied < 0) { 553 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INDISCARDS); 554 goto drop; 555 } 556 } 557 558 if (!xfrm6_route_forward(skb)) { 559 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INDISCARDS); 560 SKB_DR_SET(reason, XFRM_POLICY); 561 goto drop; 562 } 563 dst = skb_dst(skb); 564 565 /* IPv6 specs say nothing about it, but it is clear that we cannot 566 send redirects to source routed frames. 567 We don't send redirects to frames decapsulated from IPsec. 568 */ 569 if (IP6CB(skb)->iif == dst->dev->ifindex && 570 opt->srcrt == 0 && !skb_sec_path(skb)) { 571 struct in6_addr *target = NULL; 572 struct inet_peer *peer; 573 struct rt6_info *rt; 574 575 /* 576 * incoming and outgoing devices are the same 577 * send a redirect. 578 */ 579 580 rt = (struct rt6_info *) dst; 581 if (rt->rt6i_flags & RTF_GATEWAY) 582 target = &rt->rt6i_gateway; 583 else 584 target = &hdr->daddr; 585 586 peer = inet_getpeer_v6(net->ipv6.peers, &hdr->daddr, 1); 587 588 /* Limit redirects both by destination (here) 589 and by source (inside ndisc_send_redirect) 590 */ 591 if (inet_peer_xrlim_allow(peer, 1*HZ)) 592 ndisc_send_redirect(skb, target); 593 if (peer) 594 inet_putpeer(peer); 595 } else { 596 int addrtype = ipv6_addr_type(&hdr->saddr); 597 598 /* This check is security critical. */ 599 if (addrtype == IPV6_ADDR_ANY || 600 addrtype & (IPV6_ADDR_MULTICAST | IPV6_ADDR_LOOPBACK)) 601 goto error; 602 if (addrtype & IPV6_ADDR_LINKLOCAL) { 603 icmpv6_send(skb, ICMPV6_DEST_UNREACH, 604 ICMPV6_NOT_NEIGHBOUR, 0); 605 goto error; 606 } 607 } 608 609 mtu = ip6_dst_mtu_maybe_forward(dst, true); 610 if (mtu < IPV6_MIN_MTU) 611 mtu = IPV6_MIN_MTU; 612 613 if (ip6_pkt_too_big(skb, mtu)) { 614 /* Again, force OUTPUT device used as source address */ 615 skb->dev = dst->dev; 616 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu); 617 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INTOOBIGERRORS); 618 __IP6_INC_STATS(net, ip6_dst_idev(dst), 619 IPSTATS_MIB_FRAGFAILS); 620 kfree_skb_reason(skb, SKB_DROP_REASON_PKT_TOO_BIG); 621 return -EMSGSIZE; 622 } 623 624 if (skb_cow(skb, dst->dev->hard_header_len)) { 625 __IP6_INC_STATS(net, ip6_dst_idev(dst), 626 IPSTATS_MIB_OUTDISCARDS); 627 goto drop; 628 } 629 630 hdr = ipv6_hdr(skb); 631 632 /* Mangling hops number delayed to point after skb COW */ 633 634 hdr->hop_limit--; 635 636 return NF_HOOK(NFPROTO_IPV6, NF_INET_FORWARD, 637 net, NULL, skb, skb->dev, dst->dev, 638 ip6_forward_finish); 639 640 error: 641 __IP6_INC_STATS(net, idev, IPSTATS_MIB_INADDRERRORS); 642 SKB_DR_SET(reason, IP_INADDRERRORS); 643 drop: 644 kfree_skb_reason(skb, reason); 645 return -EINVAL; 646 } 647 648 static void ip6_copy_metadata(struct sk_buff *to, struct sk_buff *from) 649 { 650 to->pkt_type = from->pkt_type; 651 to->priority = from->priority; 652 to->protocol = from->protocol; 653 skb_dst_drop(to); 654 skb_dst_set(to, dst_clone(skb_dst(from))); 655 to->dev = from->dev; 656 to->mark = from->mark; 657 658 skb_copy_hash(to, from); 659 660 #ifdef CONFIG_NET_SCHED 661 to->tc_index = from->tc_index; 662 #endif 663 nf_copy(to, from); 664 skb_ext_copy(to, from); 665 skb_copy_secmark(to, from); 666 } 667 668 int ip6_fraglist_init(struct sk_buff *skb, unsigned int hlen, u8 *prevhdr, 669 u8 nexthdr, __be32 frag_id, 670 struct ip6_fraglist_iter *iter) 671 { 672 unsigned int first_len; 673 struct frag_hdr *fh; 674 675 /* BUILD HEADER */ 676 *prevhdr = NEXTHDR_FRAGMENT; 677 iter->tmp_hdr = kmemdup(skb_network_header(skb), hlen, GFP_ATOMIC); 678 if (!iter->tmp_hdr) 679 return -ENOMEM; 680 681 iter->frag = skb_shinfo(skb)->frag_list; 682 skb_frag_list_init(skb); 683 684 iter->offset = 0; 685 iter->hlen = hlen; 686 iter->frag_id = frag_id; 687 iter->nexthdr = nexthdr; 688 689 __skb_pull(skb, hlen); 690 fh = __skb_push(skb, sizeof(struct frag_hdr)); 691 __skb_push(skb, hlen); 692 skb_reset_network_header(skb); 693 memcpy(skb_network_header(skb), iter->tmp_hdr, hlen); 694 695 fh->nexthdr = nexthdr; 696 fh->reserved = 0; 697 fh->frag_off = htons(IP6_MF); 698 fh->identification = frag_id; 699 700 first_len = skb_pagelen(skb); 701 skb->data_len = first_len - skb_headlen(skb); 702 skb->len = first_len; 703 ipv6_hdr(skb)->payload_len = htons(first_len - sizeof(struct ipv6hdr)); 704 705 return 0; 706 } 707 EXPORT_SYMBOL(ip6_fraglist_init); 708 709 void ip6_fraglist_prepare(struct sk_buff *skb, 710 struct ip6_fraglist_iter *iter) 711 { 712 struct sk_buff *frag = iter->frag; 713 unsigned int hlen = iter->hlen; 714 struct frag_hdr *fh; 715 716 frag->ip_summed = CHECKSUM_NONE; 717 skb_reset_transport_header(frag); 718 fh = __skb_push(frag, sizeof(struct frag_hdr)); 719 __skb_push(frag, hlen); 720 skb_reset_network_header(frag); 721 memcpy(skb_network_header(frag), iter->tmp_hdr, hlen); 722 iter->offset += skb->len - hlen - sizeof(struct frag_hdr); 723 fh->nexthdr = iter->nexthdr; 724 fh->reserved = 0; 725 fh->frag_off = htons(iter->offset); 726 if (frag->next) 727 fh->frag_off |= htons(IP6_MF); 728 fh->identification = iter->frag_id; 729 ipv6_hdr(frag)->payload_len = htons(frag->len - sizeof(struct ipv6hdr)); 730 ip6_copy_metadata(frag, skb); 731 } 732 EXPORT_SYMBOL(ip6_fraglist_prepare); 733 734 void ip6_frag_init(struct sk_buff *skb, unsigned int hlen, unsigned int mtu, 735 unsigned short needed_tailroom, int hdr_room, u8 *prevhdr, 736 u8 nexthdr, __be32 frag_id, struct ip6_frag_state *state) 737 { 738 state->prevhdr = prevhdr; 739 state->nexthdr = nexthdr; 740 state->frag_id = frag_id; 741 742 state->hlen = hlen; 743 state->mtu = mtu; 744 745 state->left = skb->len - hlen; /* Space per frame */ 746 state->ptr = hlen; /* Where to start from */ 747 748 state->hroom = hdr_room; 749 state->troom = needed_tailroom; 750 751 state->offset = 0; 752 } 753 EXPORT_SYMBOL(ip6_frag_init); 754 755 struct sk_buff *ip6_frag_next(struct sk_buff *skb, struct ip6_frag_state *state) 756 { 757 u8 *prevhdr = state->prevhdr, *fragnexthdr_offset; 758 struct sk_buff *frag; 759 struct frag_hdr *fh; 760 unsigned int len; 761 762 len = state->left; 763 /* IF: it doesn't fit, use 'mtu' - the data space left */ 764 if (len > state->mtu) 765 len = state->mtu; 766 /* IF: we are not sending up to and including the packet end 767 then align the next start on an eight byte boundary */ 768 if (len < state->left) 769 len &= ~7; 770 771 /* Allocate buffer */ 772 frag = alloc_skb(len + state->hlen + sizeof(struct frag_hdr) + 773 state->hroom + state->troom, GFP_ATOMIC); 774 if (!frag) 775 return ERR_PTR(-ENOMEM); 776 777 /* 778 * Set up data on packet 779 */ 780 781 ip6_copy_metadata(frag, skb); 782 skb_reserve(frag, state->hroom); 783 skb_put(frag, len + state->hlen + sizeof(struct frag_hdr)); 784 skb_reset_network_header(frag); 785 fh = (struct frag_hdr *)(skb_network_header(frag) + state->hlen); 786 frag->transport_header = (frag->network_header + state->hlen + 787 sizeof(struct frag_hdr)); 788 789 /* 790 * Charge the memory for the fragment to any owner 791 * it might possess 792 */ 793 if (skb->sk) 794 skb_set_owner_w(frag, skb->sk); 795 796 /* 797 * Copy the packet header into the new buffer. 798 */ 799 skb_copy_from_linear_data(skb, skb_network_header(frag), state->hlen); 800 801 fragnexthdr_offset = skb_network_header(frag); 802 fragnexthdr_offset += prevhdr - skb_network_header(skb); 803 *fragnexthdr_offset = NEXTHDR_FRAGMENT; 804 805 /* 806 * Build fragment header. 807 */ 808 fh->nexthdr = state->nexthdr; 809 fh->reserved = 0; 810 fh->identification = state->frag_id; 811 812 /* 813 * Copy a block of the IP datagram. 814 */ 815 BUG_ON(skb_copy_bits(skb, state->ptr, skb_transport_header(frag), 816 len)); 817 state->left -= len; 818 819 fh->frag_off = htons(state->offset); 820 if (state->left > 0) 821 fh->frag_off |= htons(IP6_MF); 822 ipv6_hdr(frag)->payload_len = htons(frag->len - sizeof(struct ipv6hdr)); 823 824 state->ptr += len; 825 state->offset += len; 826 827 return frag; 828 } 829 EXPORT_SYMBOL(ip6_frag_next); 830 831 int ip6_fragment(struct net *net, struct sock *sk, struct sk_buff *skb, 832 int (*output)(struct net *, struct sock *, struct sk_buff *)) 833 { 834 struct sk_buff *frag; 835 struct rt6_info *rt = (struct rt6_info *)skb_dst(skb); 836 struct ipv6_pinfo *np = skb->sk && !dev_recursion_level() ? 837 inet6_sk(skb->sk) : NULL; 838 bool mono_delivery_time = skb->mono_delivery_time; 839 struct ip6_frag_state state; 840 unsigned int mtu, hlen, nexthdr_offset; 841 ktime_t tstamp = skb->tstamp; 842 int hroom, err = 0; 843 __be32 frag_id; 844 u8 *prevhdr, nexthdr = 0; 845 846 err = ip6_find_1stfragopt(skb, &prevhdr); 847 if (err < 0) 848 goto fail; 849 hlen = err; 850 nexthdr = *prevhdr; 851 nexthdr_offset = prevhdr - skb_network_header(skb); 852 853 mtu = ip6_skb_dst_mtu(skb); 854 855 /* We must not fragment if the socket is set to force MTU discovery 856 * or if the skb it not generated by a local socket. 857 */ 858 if (unlikely(!skb->ignore_df && skb->len > mtu)) 859 goto fail_toobig; 860 861 if (IP6CB(skb)->frag_max_size) { 862 if (IP6CB(skb)->frag_max_size > mtu) 863 goto fail_toobig; 864 865 /* don't send fragments larger than what we received */ 866 mtu = IP6CB(skb)->frag_max_size; 867 if (mtu < IPV6_MIN_MTU) 868 mtu = IPV6_MIN_MTU; 869 } 870 871 if (np && np->frag_size < mtu) { 872 if (np->frag_size) 873 mtu = np->frag_size; 874 } 875 if (mtu < hlen + sizeof(struct frag_hdr) + 8) 876 goto fail_toobig; 877 mtu -= hlen + sizeof(struct frag_hdr); 878 879 frag_id = ipv6_select_ident(net, &ipv6_hdr(skb)->daddr, 880 &ipv6_hdr(skb)->saddr); 881 882 if (skb->ip_summed == CHECKSUM_PARTIAL && 883 (err = skb_checksum_help(skb))) 884 goto fail; 885 886 prevhdr = skb_network_header(skb) + nexthdr_offset; 887 hroom = LL_RESERVED_SPACE(rt->dst.dev); 888 if (skb_has_frag_list(skb)) { 889 unsigned int first_len = skb_pagelen(skb); 890 struct ip6_fraglist_iter iter; 891 struct sk_buff *frag2; 892 893 if (first_len - hlen > mtu || 894 ((first_len - hlen) & 7) || 895 skb_cloned(skb) || 896 skb_headroom(skb) < (hroom + sizeof(struct frag_hdr))) 897 goto slow_path; 898 899 skb_walk_frags(skb, frag) { 900 /* Correct geometry. */ 901 if (frag->len > mtu || 902 ((frag->len & 7) && frag->next) || 903 skb_headroom(frag) < (hlen + hroom + sizeof(struct frag_hdr))) 904 goto slow_path_clean; 905 906 /* Partially cloned skb? */ 907 if (skb_shared(frag)) 908 goto slow_path_clean; 909 910 BUG_ON(frag->sk); 911 if (skb->sk) { 912 frag->sk = skb->sk; 913 frag->destructor = sock_wfree; 914 } 915 skb->truesize -= frag->truesize; 916 } 917 918 err = ip6_fraglist_init(skb, hlen, prevhdr, nexthdr, frag_id, 919 &iter); 920 if (err < 0) 921 goto fail; 922 923 for (;;) { 924 /* Prepare header of the next frame, 925 * before previous one went down. */ 926 if (iter.frag) 927 ip6_fraglist_prepare(skb, &iter); 928 929 skb_set_delivery_time(skb, tstamp, mono_delivery_time); 930 err = output(net, sk, skb); 931 if (!err) 932 IP6_INC_STATS(net, ip6_dst_idev(&rt->dst), 933 IPSTATS_MIB_FRAGCREATES); 934 935 if (err || !iter.frag) 936 break; 937 938 skb = ip6_fraglist_next(&iter); 939 } 940 941 kfree(iter.tmp_hdr); 942 943 if (err == 0) { 944 IP6_INC_STATS(net, ip6_dst_idev(&rt->dst), 945 IPSTATS_MIB_FRAGOKS); 946 return 0; 947 } 948 949 kfree_skb_list(iter.frag); 950 951 IP6_INC_STATS(net, ip6_dst_idev(&rt->dst), 952 IPSTATS_MIB_FRAGFAILS); 953 return err; 954 955 slow_path_clean: 956 skb_walk_frags(skb, frag2) { 957 if (frag2 == frag) 958 break; 959 frag2->sk = NULL; 960 frag2->destructor = NULL; 961 skb->truesize += frag2->truesize; 962 } 963 } 964 965 slow_path: 966 /* 967 * Fragment the datagram. 968 */ 969 970 ip6_frag_init(skb, hlen, mtu, rt->dst.dev->needed_tailroom, 971 LL_RESERVED_SPACE(rt->dst.dev), prevhdr, nexthdr, frag_id, 972 &state); 973 974 /* 975 * Keep copying data until we run out. 976 */ 977 978 while (state.left > 0) { 979 frag = ip6_frag_next(skb, &state); 980 if (IS_ERR(frag)) { 981 err = PTR_ERR(frag); 982 goto fail; 983 } 984 985 /* 986 * Put this fragment into the sending queue. 987 */ 988 skb_set_delivery_time(frag, tstamp, mono_delivery_time); 989 err = output(net, sk, frag); 990 if (err) 991 goto fail; 992 993 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), 994 IPSTATS_MIB_FRAGCREATES); 995 } 996 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), 997 IPSTATS_MIB_FRAGOKS); 998 consume_skb(skb); 999 return err; 1000 1001 fail_toobig: 1002 if (skb->sk && dst_allfrag(skb_dst(skb))) 1003 sk_gso_disable(skb->sk); 1004 1005 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu); 1006 err = -EMSGSIZE; 1007 1008 fail: 1009 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), 1010 IPSTATS_MIB_FRAGFAILS); 1011 kfree_skb(skb); 1012 return err; 1013 } 1014 1015 static inline int ip6_rt_check(const struct rt6key *rt_key, 1016 const struct in6_addr *fl_addr, 1017 const struct in6_addr *addr_cache) 1018 { 1019 return (rt_key->plen != 128 || !ipv6_addr_equal(fl_addr, &rt_key->addr)) && 1020 (!addr_cache || !ipv6_addr_equal(fl_addr, addr_cache)); 1021 } 1022 1023 static struct dst_entry *ip6_sk_dst_check(struct sock *sk, 1024 struct dst_entry *dst, 1025 const struct flowi6 *fl6) 1026 { 1027 struct ipv6_pinfo *np = inet6_sk(sk); 1028 struct rt6_info *rt; 1029 1030 if (!dst) 1031 goto out; 1032 1033 if (dst->ops->family != AF_INET6) { 1034 dst_release(dst); 1035 return NULL; 1036 } 1037 1038 rt = (struct rt6_info *)dst; 1039 /* Yes, checking route validity in not connected 1040 * case is not very simple. Take into account, 1041 * that we do not support routing by source, TOS, 1042 * and MSG_DONTROUTE --ANK (980726) 1043 * 1044 * 1. ip6_rt_check(): If route was host route, 1045 * check that cached destination is current. 1046 * If it is network route, we still may 1047 * check its validity using saved pointer 1048 * to the last used address: daddr_cache. 1049 * We do not want to save whole address now, 1050 * (because main consumer of this service 1051 * is tcp, which has not this problem), 1052 * so that the last trick works only on connected 1053 * sockets. 1054 * 2. oif also should be the same. 1055 */ 1056 if (ip6_rt_check(&rt->rt6i_dst, &fl6->daddr, np->daddr_cache) || 1057 #ifdef CONFIG_IPV6_SUBTREES 1058 ip6_rt_check(&rt->rt6i_src, &fl6->saddr, np->saddr_cache) || 1059 #endif 1060 (fl6->flowi6_oif && fl6->flowi6_oif != dst->dev->ifindex)) { 1061 dst_release(dst); 1062 dst = NULL; 1063 } 1064 1065 out: 1066 return dst; 1067 } 1068 1069 static int ip6_dst_lookup_tail(struct net *net, const struct sock *sk, 1070 struct dst_entry **dst, struct flowi6 *fl6) 1071 { 1072 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD 1073 struct neighbour *n; 1074 struct rt6_info *rt; 1075 #endif 1076 int err; 1077 int flags = 0; 1078 1079 /* The correct way to handle this would be to do 1080 * ip6_route_get_saddr, and then ip6_route_output; however, 1081 * the route-specific preferred source forces the 1082 * ip6_route_output call _before_ ip6_route_get_saddr. 1083 * 1084 * In source specific routing (no src=any default route), 1085 * ip6_route_output will fail given src=any saddr, though, so 1086 * that's why we try it again later. 1087 */ 1088 if (ipv6_addr_any(&fl6->saddr)) { 1089 struct fib6_info *from; 1090 struct rt6_info *rt; 1091 1092 *dst = ip6_route_output(net, sk, fl6); 1093 rt = (*dst)->error ? NULL : (struct rt6_info *)*dst; 1094 1095 rcu_read_lock(); 1096 from = rt ? rcu_dereference(rt->from) : NULL; 1097 err = ip6_route_get_saddr(net, from, &fl6->daddr, 1098 sk ? inet6_sk(sk)->srcprefs : 0, 1099 &fl6->saddr); 1100 rcu_read_unlock(); 1101 1102 if (err) 1103 goto out_err_release; 1104 1105 /* If we had an erroneous initial result, pretend it 1106 * never existed and let the SA-enabled version take 1107 * over. 1108 */ 1109 if ((*dst)->error) { 1110 dst_release(*dst); 1111 *dst = NULL; 1112 } 1113 1114 if (fl6->flowi6_oif) 1115 flags |= RT6_LOOKUP_F_IFACE; 1116 } 1117 1118 if (!*dst) 1119 *dst = ip6_route_output_flags(net, sk, fl6, flags); 1120 1121 err = (*dst)->error; 1122 if (err) 1123 goto out_err_release; 1124 1125 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD 1126 /* 1127 * Here if the dst entry we've looked up 1128 * has a neighbour entry that is in the INCOMPLETE 1129 * state and the src address from the flow is 1130 * marked as OPTIMISTIC, we release the found 1131 * dst entry and replace it instead with the 1132 * dst entry of the nexthop router 1133 */ 1134 rt = (struct rt6_info *) *dst; 1135 rcu_read_lock_bh(); 1136 n = __ipv6_neigh_lookup_noref(rt->dst.dev, 1137 rt6_nexthop(rt, &fl6->daddr)); 1138 err = n && !(n->nud_state & NUD_VALID) ? -EINVAL : 0; 1139 rcu_read_unlock_bh(); 1140 1141 if (err) { 1142 struct inet6_ifaddr *ifp; 1143 struct flowi6 fl_gw6; 1144 int redirect; 1145 1146 ifp = ipv6_get_ifaddr(net, &fl6->saddr, 1147 (*dst)->dev, 1); 1148 1149 redirect = (ifp && ifp->flags & IFA_F_OPTIMISTIC); 1150 if (ifp) 1151 in6_ifa_put(ifp); 1152 1153 if (redirect) { 1154 /* 1155 * We need to get the dst entry for the 1156 * default router instead 1157 */ 1158 dst_release(*dst); 1159 memcpy(&fl_gw6, fl6, sizeof(struct flowi6)); 1160 memset(&fl_gw6.daddr, 0, sizeof(struct in6_addr)); 1161 *dst = ip6_route_output(net, sk, &fl_gw6); 1162 err = (*dst)->error; 1163 if (err) 1164 goto out_err_release; 1165 } 1166 } 1167 #endif 1168 if (ipv6_addr_v4mapped(&fl6->saddr) && 1169 !(ipv6_addr_v4mapped(&fl6->daddr) || ipv6_addr_any(&fl6->daddr))) { 1170 err = -EAFNOSUPPORT; 1171 goto out_err_release; 1172 } 1173 1174 return 0; 1175 1176 out_err_release: 1177 dst_release(*dst); 1178 *dst = NULL; 1179 1180 if (err == -ENETUNREACH) 1181 IP6_INC_STATS(net, NULL, IPSTATS_MIB_OUTNOROUTES); 1182 return err; 1183 } 1184 1185 /** 1186 * ip6_dst_lookup - perform route lookup on flow 1187 * @net: Network namespace to perform lookup in 1188 * @sk: socket which provides route info 1189 * @dst: pointer to dst_entry * for result 1190 * @fl6: flow to lookup 1191 * 1192 * This function performs a route lookup on the given flow. 1193 * 1194 * It returns zero on success, or a standard errno code on error. 1195 */ 1196 int ip6_dst_lookup(struct net *net, struct sock *sk, struct dst_entry **dst, 1197 struct flowi6 *fl6) 1198 { 1199 *dst = NULL; 1200 return ip6_dst_lookup_tail(net, sk, dst, fl6); 1201 } 1202 EXPORT_SYMBOL_GPL(ip6_dst_lookup); 1203 1204 /** 1205 * ip6_dst_lookup_flow - perform route lookup on flow with ipsec 1206 * @net: Network namespace to perform lookup in 1207 * @sk: socket which provides route info 1208 * @fl6: flow to lookup 1209 * @final_dst: final destination address for ipsec lookup 1210 * 1211 * This function performs a route lookup on the given flow. 1212 * 1213 * It returns a valid dst pointer on success, or a pointer encoded 1214 * error code. 1215 */ 1216 struct dst_entry *ip6_dst_lookup_flow(struct net *net, const struct sock *sk, struct flowi6 *fl6, 1217 const struct in6_addr *final_dst) 1218 { 1219 struct dst_entry *dst = NULL; 1220 int err; 1221 1222 err = ip6_dst_lookup_tail(net, sk, &dst, fl6); 1223 if (err) 1224 return ERR_PTR(err); 1225 if (final_dst) 1226 fl6->daddr = *final_dst; 1227 1228 return xfrm_lookup_route(net, dst, flowi6_to_flowi(fl6), sk, 0); 1229 } 1230 EXPORT_SYMBOL_GPL(ip6_dst_lookup_flow); 1231 1232 /** 1233 * ip6_sk_dst_lookup_flow - perform socket cached route lookup on flow 1234 * @sk: socket which provides the dst cache and route info 1235 * @fl6: flow to lookup 1236 * @final_dst: final destination address for ipsec lookup 1237 * @connected: whether @sk is connected or not 1238 * 1239 * This function performs a route lookup on the given flow with the 1240 * possibility of using the cached route in the socket if it is valid. 1241 * It will take the socket dst lock when operating on the dst cache. 1242 * As a result, this function can only be used in process context. 1243 * 1244 * In addition, for a connected socket, cache the dst in the socket 1245 * if the current cache is not valid. 1246 * 1247 * It returns a valid dst pointer on success, or a pointer encoded 1248 * error code. 1249 */ 1250 struct dst_entry *ip6_sk_dst_lookup_flow(struct sock *sk, struct flowi6 *fl6, 1251 const struct in6_addr *final_dst, 1252 bool connected) 1253 { 1254 struct dst_entry *dst = sk_dst_check(sk, inet6_sk(sk)->dst_cookie); 1255 1256 dst = ip6_sk_dst_check(sk, dst, fl6); 1257 if (dst) 1258 return dst; 1259 1260 dst = ip6_dst_lookup_flow(sock_net(sk), sk, fl6, final_dst); 1261 if (connected && !IS_ERR(dst)) 1262 ip6_sk_dst_store_flow(sk, dst_clone(dst), fl6); 1263 1264 return dst; 1265 } 1266 EXPORT_SYMBOL_GPL(ip6_sk_dst_lookup_flow); 1267 1268 /** 1269 * ip6_dst_lookup_tunnel - perform route lookup on tunnel 1270 * @skb: Packet for which lookup is done 1271 * @dev: Tunnel device 1272 * @net: Network namespace of tunnel device 1273 * @sock: Socket which provides route info 1274 * @saddr: Memory to store the src ip address 1275 * @info: Tunnel information 1276 * @protocol: IP protocol 1277 * @use_cache: Flag to enable cache usage 1278 * This function performs a route lookup on a tunnel 1279 * 1280 * It returns a valid dst pointer and stores src address to be used in 1281 * tunnel in param saddr on success, else a pointer encoded error code. 1282 */ 1283 1284 struct dst_entry *ip6_dst_lookup_tunnel(struct sk_buff *skb, 1285 struct net_device *dev, 1286 struct net *net, 1287 struct socket *sock, 1288 struct in6_addr *saddr, 1289 const struct ip_tunnel_info *info, 1290 u8 protocol, 1291 bool use_cache) 1292 { 1293 struct dst_entry *dst = NULL; 1294 #ifdef CONFIG_DST_CACHE 1295 struct dst_cache *dst_cache; 1296 #endif 1297 struct flowi6 fl6; 1298 __u8 prio; 1299 1300 #ifdef CONFIG_DST_CACHE 1301 dst_cache = (struct dst_cache *)&info->dst_cache; 1302 if (use_cache) { 1303 dst = dst_cache_get_ip6(dst_cache, saddr); 1304 if (dst) 1305 return dst; 1306 } 1307 #endif 1308 memset(&fl6, 0, sizeof(fl6)); 1309 fl6.flowi6_mark = skb->mark; 1310 fl6.flowi6_proto = protocol; 1311 fl6.daddr = info->key.u.ipv6.dst; 1312 fl6.saddr = info->key.u.ipv6.src; 1313 prio = info->key.tos; 1314 fl6.flowlabel = ip6_make_flowinfo(prio, info->key.label); 1315 1316 dst = ipv6_stub->ipv6_dst_lookup_flow(net, sock->sk, &fl6, 1317 NULL); 1318 if (IS_ERR(dst)) { 1319 netdev_dbg(dev, "no route to %pI6\n", &fl6.daddr); 1320 return ERR_PTR(-ENETUNREACH); 1321 } 1322 if (dst->dev == dev) { /* is this necessary? */ 1323 netdev_dbg(dev, "circular route to %pI6\n", &fl6.daddr); 1324 dst_release(dst); 1325 return ERR_PTR(-ELOOP); 1326 } 1327 #ifdef CONFIG_DST_CACHE 1328 if (use_cache) 1329 dst_cache_set_ip6(dst_cache, dst, &fl6.saddr); 1330 #endif 1331 *saddr = fl6.saddr; 1332 return dst; 1333 } 1334 EXPORT_SYMBOL_GPL(ip6_dst_lookup_tunnel); 1335 1336 static inline struct ipv6_opt_hdr *ip6_opt_dup(struct ipv6_opt_hdr *src, 1337 gfp_t gfp) 1338 { 1339 return src ? kmemdup(src, (src->hdrlen + 1) * 8, gfp) : NULL; 1340 } 1341 1342 static inline struct ipv6_rt_hdr *ip6_rthdr_dup(struct ipv6_rt_hdr *src, 1343 gfp_t gfp) 1344 { 1345 return src ? kmemdup(src, (src->hdrlen + 1) * 8, gfp) : NULL; 1346 } 1347 1348 static void ip6_append_data_mtu(unsigned int *mtu, 1349 int *maxfraglen, 1350 unsigned int fragheaderlen, 1351 struct sk_buff *skb, 1352 struct rt6_info *rt, 1353 unsigned int orig_mtu) 1354 { 1355 if (!(rt->dst.flags & DST_XFRM_TUNNEL)) { 1356 if (!skb) { 1357 /* first fragment, reserve header_len */ 1358 *mtu = orig_mtu - rt->dst.header_len; 1359 1360 } else { 1361 /* 1362 * this fragment is not first, the headers 1363 * space is regarded as data space. 1364 */ 1365 *mtu = orig_mtu; 1366 } 1367 *maxfraglen = ((*mtu - fragheaderlen) & ~7) 1368 + fragheaderlen - sizeof(struct frag_hdr); 1369 } 1370 } 1371 1372 static int ip6_setup_cork(struct sock *sk, struct inet_cork_full *cork, 1373 struct inet6_cork *v6_cork, struct ipcm6_cookie *ipc6, 1374 struct rt6_info *rt) 1375 { 1376 struct ipv6_pinfo *np = inet6_sk(sk); 1377 unsigned int mtu; 1378 struct ipv6_txoptions *nopt, *opt = ipc6->opt; 1379 1380 /* callers pass dst together with a reference, set it first so 1381 * ip6_cork_release() can put it down even in case of an error. 1382 */ 1383 cork->base.dst = &rt->dst; 1384 1385 /* 1386 * setup for corking 1387 */ 1388 if (opt) { 1389 if (WARN_ON(v6_cork->opt)) 1390 return -EINVAL; 1391 1392 nopt = v6_cork->opt = kzalloc(sizeof(*opt), sk->sk_allocation); 1393 if (unlikely(!nopt)) 1394 return -ENOBUFS; 1395 1396 nopt->tot_len = sizeof(*opt); 1397 nopt->opt_flen = opt->opt_flen; 1398 nopt->opt_nflen = opt->opt_nflen; 1399 1400 nopt->dst0opt = ip6_opt_dup(opt->dst0opt, sk->sk_allocation); 1401 if (opt->dst0opt && !nopt->dst0opt) 1402 return -ENOBUFS; 1403 1404 nopt->dst1opt = ip6_opt_dup(opt->dst1opt, sk->sk_allocation); 1405 if (opt->dst1opt && !nopt->dst1opt) 1406 return -ENOBUFS; 1407 1408 nopt->hopopt = ip6_opt_dup(opt->hopopt, sk->sk_allocation); 1409 if (opt->hopopt && !nopt->hopopt) 1410 return -ENOBUFS; 1411 1412 nopt->srcrt = ip6_rthdr_dup(opt->srcrt, sk->sk_allocation); 1413 if (opt->srcrt && !nopt->srcrt) 1414 return -ENOBUFS; 1415 1416 /* need source address above miyazawa*/ 1417 } 1418 v6_cork->hop_limit = ipc6->hlimit; 1419 v6_cork->tclass = ipc6->tclass; 1420 if (rt->dst.flags & DST_XFRM_TUNNEL) 1421 mtu = np->pmtudisc >= IPV6_PMTUDISC_PROBE ? 1422 READ_ONCE(rt->dst.dev->mtu) : dst_mtu(&rt->dst); 1423 else 1424 mtu = np->pmtudisc >= IPV6_PMTUDISC_PROBE ? 1425 READ_ONCE(rt->dst.dev->mtu) : dst_mtu(xfrm_dst_path(&rt->dst)); 1426 if (np->frag_size < mtu) { 1427 if (np->frag_size) 1428 mtu = np->frag_size; 1429 } 1430 cork->base.fragsize = mtu; 1431 cork->base.gso_size = ipc6->gso_size; 1432 cork->base.tx_flags = 0; 1433 cork->base.mark = ipc6->sockc.mark; 1434 sock_tx_timestamp(sk, ipc6->sockc.tsflags, &cork->base.tx_flags); 1435 1436 if (dst_allfrag(xfrm_dst_path(&rt->dst))) 1437 cork->base.flags |= IPCORK_ALLFRAG; 1438 cork->base.length = 0; 1439 1440 cork->base.transmit_time = ipc6->sockc.transmit_time; 1441 1442 return 0; 1443 } 1444 1445 static int __ip6_append_data(struct sock *sk, 1446 struct sk_buff_head *queue, 1447 struct inet_cork_full *cork_full, 1448 struct inet6_cork *v6_cork, 1449 struct page_frag *pfrag, 1450 int getfrag(void *from, char *to, int offset, 1451 int len, int odd, struct sk_buff *skb), 1452 void *from, size_t length, int transhdrlen, 1453 unsigned int flags, struct ipcm6_cookie *ipc6) 1454 { 1455 struct sk_buff *skb, *skb_prev = NULL; 1456 struct inet_cork *cork = &cork_full->base; 1457 struct flowi6 *fl6 = &cork_full->fl.u.ip6; 1458 unsigned int maxfraglen, fragheaderlen, mtu, orig_mtu, pmtu; 1459 struct ubuf_info *uarg = NULL; 1460 int exthdrlen = 0; 1461 int dst_exthdrlen = 0; 1462 int hh_len; 1463 int copy; 1464 int err; 1465 int offset = 0; 1466 bool zc = false; 1467 u32 tskey = 0; 1468 struct rt6_info *rt = (struct rt6_info *)cork->dst; 1469 struct ipv6_txoptions *opt = v6_cork->opt; 1470 int csummode = CHECKSUM_NONE; 1471 unsigned int maxnonfragsize, headersize; 1472 unsigned int wmem_alloc_delta = 0; 1473 bool paged, extra_uref = false; 1474 1475 skb = skb_peek_tail(queue); 1476 if (!skb) { 1477 exthdrlen = opt ? opt->opt_flen : 0; 1478 dst_exthdrlen = rt->dst.header_len - rt->rt6i_nfheader_len; 1479 } 1480 1481 paged = !!cork->gso_size; 1482 mtu = cork->gso_size ? IP6_MAX_MTU : cork->fragsize; 1483 orig_mtu = mtu; 1484 1485 if (cork->tx_flags & SKBTX_ANY_SW_TSTAMP && 1486 sk->sk_tsflags & SOF_TIMESTAMPING_OPT_ID) 1487 tskey = atomic_inc_return(&sk->sk_tskey) - 1; 1488 1489 hh_len = LL_RESERVED_SPACE(rt->dst.dev); 1490 1491 fragheaderlen = sizeof(struct ipv6hdr) + rt->rt6i_nfheader_len + 1492 (opt ? opt->opt_nflen : 0); 1493 1494 headersize = sizeof(struct ipv6hdr) + 1495 (opt ? opt->opt_flen + opt->opt_nflen : 0) + 1496 (dst_allfrag(&rt->dst) ? 1497 sizeof(struct frag_hdr) : 0) + 1498 rt->rt6i_nfheader_len; 1499 1500 if (mtu <= fragheaderlen || 1501 ((mtu - fragheaderlen) & ~7) + fragheaderlen <= sizeof(struct frag_hdr)) 1502 goto emsgsize; 1503 1504 maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen - 1505 sizeof(struct frag_hdr); 1506 1507 /* as per RFC 7112 section 5, the entire IPv6 Header Chain must fit 1508 * the first fragment 1509 */ 1510 if (headersize + transhdrlen > mtu) 1511 goto emsgsize; 1512 1513 if (cork->length + length > mtu - headersize && ipc6->dontfrag && 1514 (sk->sk_protocol == IPPROTO_UDP || 1515 sk->sk_protocol == IPPROTO_ICMPV6 || 1516 sk->sk_protocol == IPPROTO_RAW)) { 1517 ipv6_local_rxpmtu(sk, fl6, mtu - headersize + 1518 sizeof(struct ipv6hdr)); 1519 goto emsgsize; 1520 } 1521 1522 if (ip6_sk_ignore_df(sk)) 1523 maxnonfragsize = sizeof(struct ipv6hdr) + IPV6_MAXPLEN; 1524 else 1525 maxnonfragsize = mtu; 1526 1527 if (cork->length + length > maxnonfragsize - headersize) { 1528 emsgsize: 1529 pmtu = max_t(int, mtu - headersize + sizeof(struct ipv6hdr), 0); 1530 ipv6_local_error(sk, EMSGSIZE, fl6, pmtu); 1531 return -EMSGSIZE; 1532 } 1533 1534 /* CHECKSUM_PARTIAL only with no extension headers and when 1535 * we are not going to fragment 1536 */ 1537 if (transhdrlen && sk->sk_protocol == IPPROTO_UDP && 1538 headersize == sizeof(struct ipv6hdr) && 1539 length <= mtu - headersize && 1540 (!(flags & MSG_MORE) || cork->gso_size) && 1541 rt->dst.dev->features & (NETIF_F_IPV6_CSUM | NETIF_F_HW_CSUM)) 1542 csummode = CHECKSUM_PARTIAL; 1543 1544 if ((flags & MSG_ZEROCOPY) && length) { 1545 struct msghdr *msg = from; 1546 1547 if (getfrag == ip_generic_getfrag && msg->msg_ubuf) { 1548 if (skb_zcopy(skb) && msg->msg_ubuf != skb_zcopy(skb)) 1549 return -EINVAL; 1550 1551 /* Leave uarg NULL if can't zerocopy, callers should 1552 * be able to handle it. 1553 */ 1554 if ((rt->dst.dev->features & NETIF_F_SG) && 1555 csummode == CHECKSUM_PARTIAL) { 1556 paged = true; 1557 zc = true; 1558 uarg = msg->msg_ubuf; 1559 } 1560 } else if (sock_flag(sk, SOCK_ZEROCOPY)) { 1561 uarg = msg_zerocopy_realloc(sk, length, skb_zcopy(skb)); 1562 if (!uarg) 1563 return -ENOBUFS; 1564 extra_uref = !skb_zcopy(skb); /* only ref on new uarg */ 1565 if (rt->dst.dev->features & NETIF_F_SG && 1566 csummode == CHECKSUM_PARTIAL) { 1567 paged = true; 1568 zc = true; 1569 } else { 1570 uarg->zerocopy = 0; 1571 skb_zcopy_set(skb, uarg, &extra_uref); 1572 } 1573 } 1574 } 1575 1576 /* 1577 * Let's try using as much space as possible. 1578 * Use MTU if total length of the message fits into the MTU. 1579 * Otherwise, we need to reserve fragment header and 1580 * fragment alignment (= 8-15 octects, in total). 1581 * 1582 * Note that we may need to "move" the data from the tail 1583 * of the buffer to the new fragment when we split 1584 * the message. 1585 * 1586 * FIXME: It may be fragmented into multiple chunks 1587 * at once if non-fragmentable extension headers 1588 * are too large. 1589 * --yoshfuji 1590 */ 1591 1592 cork->length += length; 1593 if (!skb) 1594 goto alloc_new_skb; 1595 1596 while (length > 0) { 1597 /* Check if the remaining data fits into current packet. */ 1598 copy = (cork->length <= mtu && !(cork->flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - skb->len; 1599 if (copy < length) 1600 copy = maxfraglen - skb->len; 1601 1602 if (copy <= 0) { 1603 char *data; 1604 unsigned int datalen; 1605 unsigned int fraglen; 1606 unsigned int fraggap; 1607 unsigned int alloclen, alloc_extra; 1608 unsigned int pagedlen; 1609 alloc_new_skb: 1610 /* There's no room in the current skb */ 1611 if (skb) 1612 fraggap = skb->len - maxfraglen; 1613 else 1614 fraggap = 0; 1615 /* update mtu and maxfraglen if necessary */ 1616 if (!skb || !skb_prev) 1617 ip6_append_data_mtu(&mtu, &maxfraglen, 1618 fragheaderlen, skb, rt, 1619 orig_mtu); 1620 1621 skb_prev = skb; 1622 1623 /* 1624 * If remaining data exceeds the mtu, 1625 * we know we need more fragment(s). 1626 */ 1627 datalen = length + fraggap; 1628 1629 if (datalen > (cork->length <= mtu && !(cork->flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - fragheaderlen) 1630 datalen = maxfraglen - fragheaderlen - rt->dst.trailer_len; 1631 fraglen = datalen + fragheaderlen; 1632 pagedlen = 0; 1633 1634 alloc_extra = hh_len; 1635 alloc_extra += dst_exthdrlen; 1636 alloc_extra += rt->dst.trailer_len; 1637 1638 /* We just reserve space for fragment header. 1639 * Note: this may be overallocation if the message 1640 * (without MSG_MORE) fits into the MTU. 1641 */ 1642 alloc_extra += sizeof(struct frag_hdr); 1643 1644 if ((flags & MSG_MORE) && 1645 !(rt->dst.dev->features&NETIF_F_SG)) 1646 alloclen = mtu; 1647 else if (!paged && 1648 (fraglen + alloc_extra < SKB_MAX_ALLOC || 1649 !(rt->dst.dev->features & NETIF_F_SG))) 1650 alloclen = fraglen; 1651 else if (!zc) { 1652 alloclen = min_t(int, fraglen, MAX_HEADER); 1653 pagedlen = fraglen - alloclen; 1654 } else { 1655 alloclen = fragheaderlen + transhdrlen; 1656 pagedlen = datalen - transhdrlen; 1657 } 1658 alloclen += alloc_extra; 1659 1660 if (datalen != length + fraggap) { 1661 /* 1662 * this is not the last fragment, the trailer 1663 * space is regarded as data space. 1664 */ 1665 datalen += rt->dst.trailer_len; 1666 } 1667 1668 fraglen = datalen + fragheaderlen; 1669 1670 copy = datalen - transhdrlen - fraggap - pagedlen; 1671 if (copy < 0) { 1672 err = -EINVAL; 1673 goto error; 1674 } 1675 if (transhdrlen) { 1676 skb = sock_alloc_send_skb(sk, alloclen, 1677 (flags & MSG_DONTWAIT), &err); 1678 } else { 1679 skb = NULL; 1680 if (refcount_read(&sk->sk_wmem_alloc) + wmem_alloc_delta <= 1681 2 * sk->sk_sndbuf) 1682 skb = alloc_skb(alloclen, 1683 sk->sk_allocation); 1684 if (unlikely(!skb)) 1685 err = -ENOBUFS; 1686 } 1687 if (!skb) 1688 goto error; 1689 /* 1690 * Fill in the control structures 1691 */ 1692 skb->protocol = htons(ETH_P_IPV6); 1693 skb->ip_summed = csummode; 1694 skb->csum = 0; 1695 /* reserve for fragmentation and ipsec header */ 1696 skb_reserve(skb, hh_len + sizeof(struct frag_hdr) + 1697 dst_exthdrlen); 1698 1699 /* 1700 * Find where to start putting bytes 1701 */ 1702 data = skb_put(skb, fraglen - pagedlen); 1703 skb_set_network_header(skb, exthdrlen); 1704 data += fragheaderlen; 1705 skb->transport_header = (skb->network_header + 1706 fragheaderlen); 1707 if (fraggap) { 1708 skb->csum = skb_copy_and_csum_bits( 1709 skb_prev, maxfraglen, 1710 data + transhdrlen, fraggap); 1711 skb_prev->csum = csum_sub(skb_prev->csum, 1712 skb->csum); 1713 data += fraggap; 1714 pskb_trim_unique(skb_prev, maxfraglen); 1715 } 1716 if (copy > 0 && 1717 getfrag(from, data + transhdrlen, offset, 1718 copy, fraggap, skb) < 0) { 1719 err = -EFAULT; 1720 kfree_skb(skb); 1721 goto error; 1722 } 1723 1724 offset += copy; 1725 length -= copy + transhdrlen; 1726 transhdrlen = 0; 1727 exthdrlen = 0; 1728 dst_exthdrlen = 0; 1729 1730 /* Only the initial fragment is time stamped */ 1731 skb_shinfo(skb)->tx_flags = cork->tx_flags; 1732 cork->tx_flags = 0; 1733 skb_shinfo(skb)->tskey = tskey; 1734 tskey = 0; 1735 skb_zcopy_set(skb, uarg, &extra_uref); 1736 1737 if ((flags & MSG_CONFIRM) && !skb_prev) 1738 skb_set_dst_pending_confirm(skb, 1); 1739 1740 /* 1741 * Put the packet on the pending queue 1742 */ 1743 if (!skb->destructor) { 1744 skb->destructor = sock_wfree; 1745 skb->sk = sk; 1746 wmem_alloc_delta += skb->truesize; 1747 } 1748 __skb_queue_tail(queue, skb); 1749 continue; 1750 } 1751 1752 if (copy > length) 1753 copy = length; 1754 1755 if (!(rt->dst.dev->features&NETIF_F_SG) && 1756 skb_tailroom(skb) >= copy) { 1757 unsigned int off; 1758 1759 off = skb->len; 1760 if (getfrag(from, skb_put(skb, copy), 1761 offset, copy, off, skb) < 0) { 1762 __skb_trim(skb, off); 1763 err = -EFAULT; 1764 goto error; 1765 } 1766 } else if (!zc) { 1767 int i = skb_shinfo(skb)->nr_frags; 1768 1769 err = -ENOMEM; 1770 if (!sk_page_frag_refill(sk, pfrag)) 1771 goto error; 1772 1773 skb_zcopy_downgrade_managed(skb); 1774 if (!skb_can_coalesce(skb, i, pfrag->page, 1775 pfrag->offset)) { 1776 err = -EMSGSIZE; 1777 if (i == MAX_SKB_FRAGS) 1778 goto error; 1779 1780 __skb_fill_page_desc(skb, i, pfrag->page, 1781 pfrag->offset, 0); 1782 skb_shinfo(skb)->nr_frags = ++i; 1783 get_page(pfrag->page); 1784 } 1785 copy = min_t(int, copy, pfrag->size - pfrag->offset); 1786 if (getfrag(from, 1787 page_address(pfrag->page) + pfrag->offset, 1788 offset, copy, skb->len, skb) < 0) 1789 goto error_efault; 1790 1791 pfrag->offset += copy; 1792 skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], copy); 1793 skb->len += copy; 1794 skb->data_len += copy; 1795 skb->truesize += copy; 1796 wmem_alloc_delta += copy; 1797 } else { 1798 err = skb_zerocopy_iter_dgram(skb, from, copy); 1799 if (err < 0) 1800 goto error; 1801 } 1802 offset += copy; 1803 length -= copy; 1804 } 1805 1806 if (wmem_alloc_delta) 1807 refcount_add(wmem_alloc_delta, &sk->sk_wmem_alloc); 1808 return 0; 1809 1810 error_efault: 1811 err = -EFAULT; 1812 error: 1813 net_zcopy_put_abort(uarg, extra_uref); 1814 cork->length -= length; 1815 IP6_INC_STATS(sock_net(sk), rt->rt6i_idev, IPSTATS_MIB_OUTDISCARDS); 1816 refcount_add(wmem_alloc_delta, &sk->sk_wmem_alloc); 1817 return err; 1818 } 1819 1820 int ip6_append_data(struct sock *sk, 1821 int getfrag(void *from, char *to, int offset, int len, 1822 int odd, struct sk_buff *skb), 1823 void *from, size_t length, int transhdrlen, 1824 struct ipcm6_cookie *ipc6, struct flowi6 *fl6, 1825 struct rt6_info *rt, unsigned int flags) 1826 { 1827 struct inet_sock *inet = inet_sk(sk); 1828 struct ipv6_pinfo *np = inet6_sk(sk); 1829 int exthdrlen; 1830 int err; 1831 1832 if (flags&MSG_PROBE) 1833 return 0; 1834 if (skb_queue_empty(&sk->sk_write_queue)) { 1835 /* 1836 * setup for corking 1837 */ 1838 dst_hold(&rt->dst); 1839 err = ip6_setup_cork(sk, &inet->cork, &np->cork, 1840 ipc6, rt); 1841 if (err) 1842 return err; 1843 1844 inet->cork.fl.u.ip6 = *fl6; 1845 exthdrlen = (ipc6->opt ? ipc6->opt->opt_flen : 0); 1846 length += exthdrlen; 1847 transhdrlen += exthdrlen; 1848 } else { 1849 transhdrlen = 0; 1850 } 1851 1852 return __ip6_append_data(sk, &sk->sk_write_queue, &inet->cork, 1853 &np->cork, sk_page_frag(sk), getfrag, 1854 from, length, transhdrlen, flags, ipc6); 1855 } 1856 EXPORT_SYMBOL_GPL(ip6_append_data); 1857 1858 static void ip6_cork_steal_dst(struct sk_buff *skb, struct inet_cork_full *cork) 1859 { 1860 struct dst_entry *dst = cork->base.dst; 1861 1862 cork->base.dst = NULL; 1863 cork->base.flags &= ~IPCORK_ALLFRAG; 1864 skb_dst_set(skb, dst); 1865 } 1866 1867 static void ip6_cork_release(struct inet_cork_full *cork, 1868 struct inet6_cork *v6_cork) 1869 { 1870 if (v6_cork->opt) { 1871 struct ipv6_txoptions *opt = v6_cork->opt; 1872 1873 kfree(opt->dst0opt); 1874 kfree(opt->dst1opt); 1875 kfree(opt->hopopt); 1876 kfree(opt->srcrt); 1877 kfree(opt); 1878 v6_cork->opt = NULL; 1879 } 1880 1881 if (cork->base.dst) { 1882 dst_release(cork->base.dst); 1883 cork->base.dst = NULL; 1884 cork->base.flags &= ~IPCORK_ALLFRAG; 1885 } 1886 } 1887 1888 struct sk_buff *__ip6_make_skb(struct sock *sk, 1889 struct sk_buff_head *queue, 1890 struct inet_cork_full *cork, 1891 struct inet6_cork *v6_cork) 1892 { 1893 struct sk_buff *skb, *tmp_skb; 1894 struct sk_buff **tail_skb; 1895 struct in6_addr *final_dst; 1896 struct ipv6_pinfo *np = inet6_sk(sk); 1897 struct net *net = sock_net(sk); 1898 struct ipv6hdr *hdr; 1899 struct ipv6_txoptions *opt = v6_cork->opt; 1900 struct rt6_info *rt = (struct rt6_info *)cork->base.dst; 1901 struct flowi6 *fl6 = &cork->fl.u.ip6; 1902 unsigned char proto = fl6->flowi6_proto; 1903 1904 skb = __skb_dequeue(queue); 1905 if (!skb) 1906 goto out; 1907 tail_skb = &(skb_shinfo(skb)->frag_list); 1908 1909 /* move skb->data to ip header from ext header */ 1910 if (skb->data < skb_network_header(skb)) 1911 __skb_pull(skb, skb_network_offset(skb)); 1912 while ((tmp_skb = __skb_dequeue(queue)) != NULL) { 1913 __skb_pull(tmp_skb, skb_network_header_len(skb)); 1914 *tail_skb = tmp_skb; 1915 tail_skb = &(tmp_skb->next); 1916 skb->len += tmp_skb->len; 1917 skb->data_len += tmp_skb->len; 1918 skb->truesize += tmp_skb->truesize; 1919 tmp_skb->destructor = NULL; 1920 tmp_skb->sk = NULL; 1921 } 1922 1923 /* Allow local fragmentation. */ 1924 skb->ignore_df = ip6_sk_ignore_df(sk); 1925 __skb_pull(skb, skb_network_header_len(skb)); 1926 1927 final_dst = &fl6->daddr; 1928 if (opt && opt->opt_flen) 1929 ipv6_push_frag_opts(skb, opt, &proto); 1930 if (opt && opt->opt_nflen) 1931 ipv6_push_nfrag_opts(skb, opt, &proto, &final_dst, &fl6->saddr); 1932 1933 skb_push(skb, sizeof(struct ipv6hdr)); 1934 skb_reset_network_header(skb); 1935 hdr = ipv6_hdr(skb); 1936 1937 ip6_flow_hdr(hdr, v6_cork->tclass, 1938 ip6_make_flowlabel(net, skb, fl6->flowlabel, 1939 ip6_autoflowlabel(net, np), fl6)); 1940 hdr->hop_limit = v6_cork->hop_limit; 1941 hdr->nexthdr = proto; 1942 hdr->saddr = fl6->saddr; 1943 hdr->daddr = *final_dst; 1944 1945 skb->priority = sk->sk_priority; 1946 skb->mark = cork->base.mark; 1947 skb->tstamp = cork->base.transmit_time; 1948 1949 ip6_cork_steal_dst(skb, cork); 1950 IP6_UPD_PO_STATS(net, rt->rt6i_idev, IPSTATS_MIB_OUT, skb->len); 1951 if (proto == IPPROTO_ICMPV6) { 1952 struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb)); 1953 1954 ICMP6MSGOUT_INC_STATS(net, idev, icmp6_hdr(skb)->icmp6_type); 1955 ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTMSGS); 1956 } 1957 1958 ip6_cork_release(cork, v6_cork); 1959 out: 1960 return skb; 1961 } 1962 1963 int ip6_send_skb(struct sk_buff *skb) 1964 { 1965 struct net *net = sock_net(skb->sk); 1966 struct rt6_info *rt = (struct rt6_info *)skb_dst(skb); 1967 int err; 1968 1969 err = ip6_local_out(net, skb->sk, skb); 1970 if (err) { 1971 if (err > 0) 1972 err = net_xmit_errno(err); 1973 if (err) 1974 IP6_INC_STATS(net, rt->rt6i_idev, 1975 IPSTATS_MIB_OUTDISCARDS); 1976 } 1977 1978 return err; 1979 } 1980 1981 int ip6_push_pending_frames(struct sock *sk) 1982 { 1983 struct sk_buff *skb; 1984 1985 skb = ip6_finish_skb(sk); 1986 if (!skb) 1987 return 0; 1988 1989 return ip6_send_skb(skb); 1990 } 1991 EXPORT_SYMBOL_GPL(ip6_push_pending_frames); 1992 1993 static void __ip6_flush_pending_frames(struct sock *sk, 1994 struct sk_buff_head *queue, 1995 struct inet_cork_full *cork, 1996 struct inet6_cork *v6_cork) 1997 { 1998 struct sk_buff *skb; 1999 2000 while ((skb = __skb_dequeue_tail(queue)) != NULL) { 2001 if (skb_dst(skb)) 2002 IP6_INC_STATS(sock_net(sk), ip6_dst_idev(skb_dst(skb)), 2003 IPSTATS_MIB_OUTDISCARDS); 2004 kfree_skb(skb); 2005 } 2006 2007 ip6_cork_release(cork, v6_cork); 2008 } 2009 2010 void ip6_flush_pending_frames(struct sock *sk) 2011 { 2012 __ip6_flush_pending_frames(sk, &sk->sk_write_queue, 2013 &inet_sk(sk)->cork, &inet6_sk(sk)->cork); 2014 } 2015 EXPORT_SYMBOL_GPL(ip6_flush_pending_frames); 2016 2017 struct sk_buff *ip6_make_skb(struct sock *sk, 2018 int getfrag(void *from, char *to, int offset, 2019 int len, int odd, struct sk_buff *skb), 2020 void *from, size_t length, int transhdrlen, 2021 struct ipcm6_cookie *ipc6, struct rt6_info *rt, 2022 unsigned int flags, struct inet_cork_full *cork) 2023 { 2024 struct inet6_cork v6_cork; 2025 struct sk_buff_head queue; 2026 int exthdrlen = (ipc6->opt ? ipc6->opt->opt_flen : 0); 2027 int err; 2028 2029 if (flags & MSG_PROBE) { 2030 dst_release(&rt->dst); 2031 return NULL; 2032 } 2033 2034 __skb_queue_head_init(&queue); 2035 2036 cork->base.flags = 0; 2037 cork->base.addr = 0; 2038 cork->base.opt = NULL; 2039 v6_cork.opt = NULL; 2040 err = ip6_setup_cork(sk, cork, &v6_cork, ipc6, rt); 2041 if (err) { 2042 ip6_cork_release(cork, &v6_cork); 2043 return ERR_PTR(err); 2044 } 2045 if (ipc6->dontfrag < 0) 2046 ipc6->dontfrag = inet6_sk(sk)->dontfrag; 2047 2048 err = __ip6_append_data(sk, &queue, cork, &v6_cork, 2049 ¤t->task_frag, getfrag, from, 2050 length + exthdrlen, transhdrlen + exthdrlen, 2051 flags, ipc6); 2052 if (err) { 2053 __ip6_flush_pending_frames(sk, &queue, cork, &v6_cork); 2054 return ERR_PTR(err); 2055 } 2056 2057 return __ip6_make_skb(sk, &queue, cork, &v6_cork); 2058 } 2059