| 1 | /* |
| 2 | * IPv6 output functions |
| 3 | * Linux INET6 implementation |
| 4 | * |
| 5 | * Authors: |
| 6 | * Pedro Roque <roque@di.fc.ul.pt> |
| 7 | * |
| 8 | * Based on linux/net/ipv4/ip_output.c |
| 9 | * |
| 10 | * This program is free software; you can redistribute it and/or |
| 11 | * modify it under the terms of the GNU General Public License |
| 12 | * as published by the Free Software Foundation; either version |
| 13 | * 2 of the License, or (at your option) any later version. |
| 14 | * |
| 15 | * Changes: |
| 16 | * A.N.Kuznetsov : airthmetics in fragmentation. |
| 17 | * extension headers are implemented. |
| 18 | * route changes now work. |
| 19 | * ip6_forward does not confuse sniffers. |
| 20 | * etc. |
| 21 | * |
| 22 | * H. von Brand : Added missing #include <linux/string.h> |
| 23 | * Imran Patel : frag id should be in NBO |
| 24 | * Kazunori MIYAZAWA @USAGI |
| 25 | * : add ip6_append_data and related functions |
| 26 | * for datagram xmit |
| 27 | */ |
| 28 | |
| 29 | #include <linux/errno.h> |
| 30 | #include <linux/kernel.h> |
| 31 | #include <linux/string.h> |
| 32 | #include <linux/socket.h> |
| 33 | #include <linux/net.h> |
| 34 | #include <linux/netdevice.h> |
| 35 | #include <linux/if_arp.h> |
| 36 | #include <linux/in6.h> |
| 37 | #include <linux/tcp.h> |
| 38 | #include <linux/route.h> |
| 39 | #include <linux/module.h> |
| 40 | #include <linux/slab.h> |
| 41 | |
| 42 | #include <linux/netfilter.h> |
| 43 | #include <linux/netfilter_ipv6.h> |
| 44 | |
| 45 | #include <net/sock.h> |
| 46 | #include <net/snmp.h> |
| 47 | |
| 48 | #include <net/ipv6.h> |
| 49 | #include <net/ndisc.h> |
| 50 | #include <net/protocol.h> |
| 51 | #include <net/ip6_route.h> |
| 52 | #include <net/addrconf.h> |
| 53 | #include <net/rawv6.h> |
| 54 | #include <net/icmp.h> |
| 55 | #include <net/xfrm.h> |
| 56 | #include <net/checksum.h> |
| 57 | #include <linux/mroute6.h> |
| 58 | #include <net/l3mdev.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 neighbour *neigh; |
| 65 | struct in6_addr *nexthop; |
| 66 | int ret; |
| 67 | |
| 68 | skb->protocol = htons(ETH_P_IPV6); |
| 69 | skb->dev = dev; |
| 70 | |
| 71 | if (ipv6_addr_is_multicast(&ipv6_hdr(skb)->daddr)) { |
| 72 | struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb)); |
| 73 | |
| 74 | if (!(dev->flags & IFF_LOOPBACK) && sk_mc_loop(sk) && |
| 75 | ((mroute6_socket(net, skb) && |
| 76 | !(IP6CB(skb)->flags & IP6SKB_FORWARDED)) || |
| 77 | ipv6_chk_mcast_addr(dev, &ipv6_hdr(skb)->daddr, |
| 78 | &ipv6_hdr(skb)->saddr))) { |
| 79 | struct sk_buff *newskb = skb_clone(skb, GFP_ATOMIC); |
| 80 | |
| 81 | /* Do not check for IFF_ALLMULTI; multicast routing |
| 82 | is not supported in any case. |
| 83 | */ |
| 84 | if (newskb) |
| 85 | NF_HOOK(NFPROTO_IPV6, NF_INET_POST_ROUTING, |
| 86 | net, sk, newskb, NULL, newskb->dev, |
| 87 | dev_loopback_xmit); |
| 88 | |
| 89 | if (ipv6_hdr(skb)->hop_limit == 0) { |
| 90 | IP6_INC_STATS(net, idev, |
| 91 | IPSTATS_MIB_OUTDISCARDS); |
| 92 | kfree_skb(skb); |
| 93 | return 0; |
| 94 | } |
| 95 | } |
| 96 | |
| 97 | IP6_UPD_PO_STATS(net, idev, IPSTATS_MIB_OUTMCAST, skb->len); |
| 98 | |
| 99 | if (IPV6_ADDR_MC_SCOPE(&ipv6_hdr(skb)->daddr) <= |
| 100 | IPV6_ADDR_SCOPE_NODELOCAL && |
| 101 | !(dev->flags & IFF_LOOPBACK)) { |
| 102 | kfree_skb(skb); |
| 103 | return 0; |
| 104 | } |
| 105 | } |
| 106 | |
| 107 | rcu_read_lock_bh(); |
| 108 | nexthop = rt6_nexthop((struct rt6_info *)dst, &ipv6_hdr(skb)->daddr); |
| 109 | neigh = __ipv6_neigh_lookup_noref(dst->dev, nexthop); |
| 110 | if (unlikely(!neigh)) |
| 111 | neigh = __neigh_create(&nd_tbl, nexthop, dst->dev, false); |
| 112 | if (!IS_ERR(neigh)) { |
| 113 | ret = dst_neigh_output(dst, neigh, skb); |
| 114 | rcu_read_unlock_bh(); |
| 115 | return ret; |
| 116 | } |
| 117 | rcu_read_unlock_bh(); |
| 118 | |
| 119 | IP6_INC_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTNOROUTES); |
| 120 | kfree_skb(skb); |
| 121 | return -EINVAL; |
| 122 | } |
| 123 | |
| 124 | static int ip6_finish_output(struct net *net, struct sock *sk, struct sk_buff *skb) |
| 125 | { |
| 126 | if ((skb->len > ip6_skb_dst_mtu(skb) && !skb_is_gso(skb)) || |
| 127 | dst_allfrag(skb_dst(skb)) || |
| 128 | (IP6CB(skb)->frag_max_size && skb->len > IP6CB(skb)->frag_max_size)) |
| 129 | return ip6_fragment(net, sk, skb, ip6_finish_output2); |
| 130 | else |
| 131 | return ip6_finish_output2(net, sk, skb); |
| 132 | } |
| 133 | |
| 134 | int ip6_output(struct net *net, struct sock *sk, struct sk_buff *skb) |
| 135 | { |
| 136 | struct net_device *dev = skb_dst(skb)->dev; |
| 137 | struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb)); |
| 138 | |
| 139 | if (unlikely(idev->cnf.disable_ipv6)) { |
| 140 | IP6_INC_STATS(net, idev, IPSTATS_MIB_OUTDISCARDS); |
| 141 | kfree_skb(skb); |
| 142 | return 0; |
| 143 | } |
| 144 | |
| 145 | return NF_HOOK_COND(NFPROTO_IPV6, NF_INET_POST_ROUTING, |
| 146 | net, sk, skb, NULL, dev, |
| 147 | ip6_finish_output, |
| 148 | !(IP6CB(skb)->flags & IP6SKB_REROUTED)); |
| 149 | } |
| 150 | |
| 151 | /* |
| 152 | * xmit an sk_buff (used by TCP, SCTP and DCCP) |
| 153 | * Note : socket lock is not held for SYNACK packets, but might be modified |
| 154 | * by calls to skb_set_owner_w() and ipv6_local_error(), |
| 155 | * which are using proper atomic operations or spinlocks. |
| 156 | */ |
| 157 | int ip6_xmit(const struct sock *sk, struct sk_buff *skb, struct flowi6 *fl6, |
| 158 | struct ipv6_txoptions *opt, int tclass) |
| 159 | { |
| 160 | struct net *net = sock_net(sk); |
| 161 | const struct ipv6_pinfo *np = inet6_sk(sk); |
| 162 | struct in6_addr *first_hop = &fl6->daddr; |
| 163 | struct dst_entry *dst = skb_dst(skb); |
| 164 | struct ipv6hdr *hdr; |
| 165 | u8 proto = fl6->flowi6_proto; |
| 166 | int seg_len = skb->len; |
| 167 | int hlimit = -1; |
| 168 | u32 mtu; |
| 169 | |
| 170 | if (opt) { |
| 171 | unsigned int head_room; |
| 172 | |
| 173 | /* First: exthdrs may take lots of space (~8K for now) |
| 174 | MAX_HEADER is not enough. |
| 175 | */ |
| 176 | head_room = opt->opt_nflen + opt->opt_flen; |
| 177 | seg_len += head_room; |
| 178 | head_room += sizeof(struct ipv6hdr) + LL_RESERVED_SPACE(dst->dev); |
| 179 | |
| 180 | if (skb_headroom(skb) < head_room) { |
| 181 | struct sk_buff *skb2 = skb_realloc_headroom(skb, head_room); |
| 182 | if (!skb2) { |
| 183 | IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), |
| 184 | IPSTATS_MIB_OUTDISCARDS); |
| 185 | kfree_skb(skb); |
| 186 | return -ENOBUFS; |
| 187 | } |
| 188 | consume_skb(skb); |
| 189 | skb = skb2; |
| 190 | /* skb_set_owner_w() changes sk->sk_wmem_alloc atomically, |
| 191 | * it is safe to call in our context (socket lock not held) |
| 192 | */ |
| 193 | skb_set_owner_w(skb, (struct sock *)sk); |
| 194 | } |
| 195 | if (opt->opt_flen) |
| 196 | ipv6_push_frag_opts(skb, opt, &proto); |
| 197 | if (opt->opt_nflen) |
| 198 | ipv6_push_nfrag_opts(skb, opt, &proto, &first_hop); |
| 199 | } |
| 200 | |
| 201 | skb_push(skb, sizeof(struct ipv6hdr)); |
| 202 | skb_reset_network_header(skb); |
| 203 | hdr = ipv6_hdr(skb); |
| 204 | |
| 205 | /* |
| 206 | * Fill in the IPv6 header |
| 207 | */ |
| 208 | if (np) |
| 209 | hlimit = np->hop_limit; |
| 210 | if (hlimit < 0) |
| 211 | hlimit = ip6_dst_hoplimit(dst); |
| 212 | |
| 213 | ip6_flow_hdr(hdr, tclass, ip6_make_flowlabel(net, skb, fl6->flowlabel, |
| 214 | np->autoflowlabel, fl6)); |
| 215 | |
| 216 | hdr->payload_len = htons(seg_len); |
| 217 | hdr->nexthdr = proto; |
| 218 | hdr->hop_limit = hlimit; |
| 219 | |
| 220 | hdr->saddr = fl6->saddr; |
| 221 | hdr->daddr = *first_hop; |
| 222 | |
| 223 | skb->protocol = htons(ETH_P_IPV6); |
| 224 | skb->priority = sk->sk_priority; |
| 225 | skb->mark = sk->sk_mark; |
| 226 | |
| 227 | mtu = dst_mtu(dst); |
| 228 | if ((skb->len <= mtu) || skb->ignore_df || skb_is_gso(skb)) { |
| 229 | IP6_UPD_PO_STATS(net, ip6_dst_idev(skb_dst(skb)), |
| 230 | IPSTATS_MIB_OUT, skb->len); |
| 231 | /* hooks should never assume socket lock is held. |
| 232 | * we promote our socket to non const |
| 233 | */ |
| 234 | return NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT, |
| 235 | net, (struct sock *)sk, skb, NULL, dst->dev, |
| 236 | dst_output); |
| 237 | } |
| 238 | |
| 239 | skb->dev = dst->dev; |
| 240 | /* ipv6_local_error() does not require socket lock, |
| 241 | * we promote our socket to non const |
| 242 | */ |
| 243 | ipv6_local_error((struct sock *)sk, EMSGSIZE, fl6, mtu); |
| 244 | |
| 245 | IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_FRAGFAILS); |
| 246 | kfree_skb(skb); |
| 247 | return -EMSGSIZE; |
| 248 | } |
| 249 | EXPORT_SYMBOL(ip6_xmit); |
| 250 | |
| 251 | static int ip6_call_ra_chain(struct sk_buff *skb, int sel) |
| 252 | { |
| 253 | struct ip6_ra_chain *ra; |
| 254 | struct sock *last = NULL; |
| 255 | |
| 256 | read_lock(&ip6_ra_lock); |
| 257 | for (ra = ip6_ra_chain; ra; ra = ra->next) { |
| 258 | struct sock *sk = ra->sk; |
| 259 | if (sk && ra->sel == sel && |
| 260 | (!sk->sk_bound_dev_if || |
| 261 | sk->sk_bound_dev_if == skb->dev->ifindex)) { |
| 262 | if (last) { |
| 263 | struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC); |
| 264 | if (skb2) |
| 265 | rawv6_rcv(last, skb2); |
| 266 | } |
| 267 | last = sk; |
| 268 | } |
| 269 | } |
| 270 | |
| 271 | if (last) { |
| 272 | rawv6_rcv(last, skb); |
| 273 | read_unlock(&ip6_ra_lock); |
| 274 | return 1; |
| 275 | } |
| 276 | read_unlock(&ip6_ra_lock); |
| 277 | return 0; |
| 278 | } |
| 279 | |
| 280 | static int ip6_forward_proxy_check(struct sk_buff *skb) |
| 281 | { |
| 282 | struct ipv6hdr *hdr = ipv6_hdr(skb); |
| 283 | u8 nexthdr = hdr->nexthdr; |
| 284 | __be16 frag_off; |
| 285 | int offset; |
| 286 | |
| 287 | if (ipv6_ext_hdr(nexthdr)) { |
| 288 | offset = ipv6_skip_exthdr(skb, sizeof(*hdr), &nexthdr, &frag_off); |
| 289 | if (offset < 0) |
| 290 | return 0; |
| 291 | } else |
| 292 | offset = sizeof(struct ipv6hdr); |
| 293 | |
| 294 | if (nexthdr == IPPROTO_ICMPV6) { |
| 295 | struct icmp6hdr *icmp6; |
| 296 | |
| 297 | if (!pskb_may_pull(skb, (skb_network_header(skb) + |
| 298 | offset + 1 - skb->data))) |
| 299 | return 0; |
| 300 | |
| 301 | icmp6 = (struct icmp6hdr *)(skb_network_header(skb) + offset); |
| 302 | |
| 303 | switch (icmp6->icmp6_type) { |
| 304 | case NDISC_ROUTER_SOLICITATION: |
| 305 | case NDISC_ROUTER_ADVERTISEMENT: |
| 306 | case NDISC_NEIGHBOUR_SOLICITATION: |
| 307 | case NDISC_NEIGHBOUR_ADVERTISEMENT: |
| 308 | case NDISC_REDIRECT: |
| 309 | /* For reaction involving unicast neighbor discovery |
| 310 | * message destined to the proxied address, pass it to |
| 311 | * input function. |
| 312 | */ |
| 313 | return 1; |
| 314 | default: |
| 315 | break; |
| 316 | } |
| 317 | } |
| 318 | |
| 319 | /* |
| 320 | * The proxying router can't forward traffic sent to a link-local |
| 321 | * address, so signal the sender and discard the packet. This |
| 322 | * behavior is clarified by the MIPv6 specification. |
| 323 | */ |
| 324 | if (ipv6_addr_type(&hdr->daddr) & IPV6_ADDR_LINKLOCAL) { |
| 325 | dst_link_failure(skb); |
| 326 | return -1; |
| 327 | } |
| 328 | |
| 329 | return 0; |
| 330 | } |
| 331 | |
| 332 | static inline int ip6_forward_finish(struct net *net, struct sock *sk, |
| 333 | struct sk_buff *skb) |
| 334 | { |
| 335 | return dst_output(net, sk, skb); |
| 336 | } |
| 337 | |
| 338 | static unsigned int ip6_dst_mtu_forward(const struct dst_entry *dst) |
| 339 | { |
| 340 | unsigned int mtu; |
| 341 | struct inet6_dev *idev; |
| 342 | |
| 343 | if (dst_metric_locked(dst, RTAX_MTU)) { |
| 344 | mtu = dst_metric_raw(dst, RTAX_MTU); |
| 345 | if (mtu) |
| 346 | return mtu; |
| 347 | } |
| 348 | |
| 349 | mtu = IPV6_MIN_MTU; |
| 350 | rcu_read_lock(); |
| 351 | idev = __in6_dev_get(dst->dev); |
| 352 | if (idev) |
| 353 | mtu = idev->cnf.mtu6; |
| 354 | rcu_read_unlock(); |
| 355 | |
| 356 | return mtu; |
| 357 | } |
| 358 | |
| 359 | static bool ip6_pkt_too_big(const struct sk_buff *skb, unsigned int mtu) |
| 360 | { |
| 361 | if (skb->len <= mtu) |
| 362 | return false; |
| 363 | |
| 364 | /* ipv6 conntrack defrag sets max_frag_size + ignore_df */ |
| 365 | if (IP6CB(skb)->frag_max_size && IP6CB(skb)->frag_max_size > mtu) |
| 366 | return true; |
| 367 | |
| 368 | if (skb->ignore_df) |
| 369 | return false; |
| 370 | |
| 371 | if (skb_is_gso(skb) && skb_gso_network_seglen(skb) <= mtu) |
| 372 | return false; |
| 373 | |
| 374 | return true; |
| 375 | } |
| 376 | |
| 377 | int ip6_forward(struct sk_buff *skb) |
| 378 | { |
| 379 | struct dst_entry *dst = skb_dst(skb); |
| 380 | struct ipv6hdr *hdr = ipv6_hdr(skb); |
| 381 | struct inet6_skb_parm *opt = IP6CB(skb); |
| 382 | struct net *net = dev_net(dst->dev); |
| 383 | u32 mtu; |
| 384 | |
| 385 | if (net->ipv6.devconf_all->forwarding == 0) |
| 386 | goto error; |
| 387 | |
| 388 | if (skb->pkt_type != PACKET_HOST) |
| 389 | goto drop; |
| 390 | |
| 391 | if (unlikely(skb->sk)) |
| 392 | goto drop; |
| 393 | |
| 394 | if (skb_warn_if_lro(skb)) |
| 395 | goto drop; |
| 396 | |
| 397 | if (!xfrm6_policy_check(NULL, XFRM_POLICY_FWD, skb)) { |
| 398 | IP6_INC_STATS_BH(net, ip6_dst_idev(dst), |
| 399 | IPSTATS_MIB_INDISCARDS); |
| 400 | goto drop; |
| 401 | } |
| 402 | |
| 403 | skb_forward_csum(skb); |
| 404 | |
| 405 | /* |
| 406 | * We DO NOT make any processing on |
| 407 | * RA packets, pushing them to user level AS IS |
| 408 | * without ane WARRANTY that application will be able |
| 409 | * to interpret them. The reason is that we |
| 410 | * cannot make anything clever here. |
| 411 | * |
| 412 | * We are not end-node, so that if packet contains |
| 413 | * AH/ESP, we cannot make anything. |
| 414 | * Defragmentation also would be mistake, RA packets |
| 415 | * cannot be fragmented, because there is no warranty |
| 416 | * that different fragments will go along one path. --ANK |
| 417 | */ |
| 418 | if (unlikely(opt->flags & IP6SKB_ROUTERALERT)) { |
| 419 | if (ip6_call_ra_chain(skb, ntohs(opt->ra))) |
| 420 | return 0; |
| 421 | } |
| 422 | |
| 423 | /* |
| 424 | * check and decrement ttl |
| 425 | */ |
| 426 | if (hdr->hop_limit <= 1) { |
| 427 | /* Force OUTPUT device used as source address */ |
| 428 | skb->dev = dst->dev; |
| 429 | icmpv6_send(skb, ICMPV6_TIME_EXCEED, ICMPV6_EXC_HOPLIMIT, 0); |
| 430 | IP6_INC_STATS_BH(net, ip6_dst_idev(dst), |
| 431 | IPSTATS_MIB_INHDRERRORS); |
| 432 | |
| 433 | kfree_skb(skb); |
| 434 | return -ETIMEDOUT; |
| 435 | } |
| 436 | |
| 437 | /* XXX: idev->cnf.proxy_ndp? */ |
| 438 | if (net->ipv6.devconf_all->proxy_ndp && |
| 439 | pneigh_lookup(&nd_tbl, net, &hdr->daddr, skb->dev, 0)) { |
| 440 | int proxied = ip6_forward_proxy_check(skb); |
| 441 | if (proxied > 0) |
| 442 | return ip6_input(skb); |
| 443 | else if (proxied < 0) { |
| 444 | IP6_INC_STATS_BH(net, ip6_dst_idev(dst), |
| 445 | IPSTATS_MIB_INDISCARDS); |
| 446 | goto drop; |
| 447 | } |
| 448 | } |
| 449 | |
| 450 | if (!xfrm6_route_forward(skb)) { |
| 451 | IP6_INC_STATS_BH(net, ip6_dst_idev(dst), |
| 452 | IPSTATS_MIB_INDISCARDS); |
| 453 | goto drop; |
| 454 | } |
| 455 | dst = skb_dst(skb); |
| 456 | |
| 457 | /* IPv6 specs say nothing about it, but it is clear that we cannot |
| 458 | send redirects to source routed frames. |
| 459 | We don't send redirects to frames decapsulated from IPsec. |
| 460 | */ |
| 461 | if (skb->dev == dst->dev && opt->srcrt == 0 && !skb_sec_path(skb)) { |
| 462 | struct in6_addr *target = NULL; |
| 463 | struct inet_peer *peer; |
| 464 | struct rt6_info *rt; |
| 465 | |
| 466 | /* |
| 467 | * incoming and outgoing devices are the same |
| 468 | * send a redirect. |
| 469 | */ |
| 470 | |
| 471 | rt = (struct rt6_info *) dst; |
| 472 | if (rt->rt6i_flags & RTF_GATEWAY) |
| 473 | target = &rt->rt6i_gateway; |
| 474 | else |
| 475 | target = &hdr->daddr; |
| 476 | |
| 477 | peer = inet_getpeer_v6(net->ipv6.peers, &hdr->daddr, 1); |
| 478 | |
| 479 | /* Limit redirects both by destination (here) |
| 480 | and by source (inside ndisc_send_redirect) |
| 481 | */ |
| 482 | if (inet_peer_xrlim_allow(peer, 1*HZ)) |
| 483 | ndisc_send_redirect(skb, target); |
| 484 | if (peer) |
| 485 | inet_putpeer(peer); |
| 486 | } else { |
| 487 | int addrtype = ipv6_addr_type(&hdr->saddr); |
| 488 | |
| 489 | /* This check is security critical. */ |
| 490 | if (addrtype == IPV6_ADDR_ANY || |
| 491 | addrtype & (IPV6_ADDR_MULTICAST | IPV6_ADDR_LOOPBACK)) |
| 492 | goto error; |
| 493 | if (addrtype & IPV6_ADDR_LINKLOCAL) { |
| 494 | icmpv6_send(skb, ICMPV6_DEST_UNREACH, |
| 495 | ICMPV6_NOT_NEIGHBOUR, 0); |
| 496 | goto error; |
| 497 | } |
| 498 | } |
| 499 | |
| 500 | mtu = ip6_dst_mtu_forward(dst); |
| 501 | if (mtu < IPV6_MIN_MTU) |
| 502 | mtu = IPV6_MIN_MTU; |
| 503 | |
| 504 | if (ip6_pkt_too_big(skb, mtu)) { |
| 505 | /* Again, force OUTPUT device used as source address */ |
| 506 | skb->dev = dst->dev; |
| 507 | icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu); |
| 508 | IP6_INC_STATS_BH(net, ip6_dst_idev(dst), |
| 509 | IPSTATS_MIB_INTOOBIGERRORS); |
| 510 | IP6_INC_STATS_BH(net, ip6_dst_idev(dst), |
| 511 | IPSTATS_MIB_FRAGFAILS); |
| 512 | kfree_skb(skb); |
| 513 | return -EMSGSIZE; |
| 514 | } |
| 515 | |
| 516 | if (skb_cow(skb, dst->dev->hard_header_len)) { |
| 517 | IP6_INC_STATS_BH(net, ip6_dst_idev(dst), |
| 518 | IPSTATS_MIB_OUTDISCARDS); |
| 519 | goto drop; |
| 520 | } |
| 521 | |
| 522 | hdr = ipv6_hdr(skb); |
| 523 | |
| 524 | /* Mangling hops number delayed to point after skb COW */ |
| 525 | |
| 526 | hdr->hop_limit--; |
| 527 | |
| 528 | IP6_INC_STATS_BH(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTFORWDATAGRAMS); |
| 529 | IP6_ADD_STATS_BH(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTOCTETS, skb->len); |
| 530 | return NF_HOOK(NFPROTO_IPV6, NF_INET_FORWARD, |
| 531 | net, NULL, skb, skb->dev, dst->dev, |
| 532 | ip6_forward_finish); |
| 533 | |
| 534 | error: |
| 535 | IP6_INC_STATS_BH(net, ip6_dst_idev(dst), IPSTATS_MIB_INADDRERRORS); |
| 536 | drop: |
| 537 | kfree_skb(skb); |
| 538 | return -EINVAL; |
| 539 | } |
| 540 | |
| 541 | static void ip6_copy_metadata(struct sk_buff *to, struct sk_buff *from) |
| 542 | { |
| 543 | to->pkt_type = from->pkt_type; |
| 544 | to->priority = from->priority; |
| 545 | to->protocol = from->protocol; |
| 546 | skb_dst_drop(to); |
| 547 | skb_dst_set(to, dst_clone(skb_dst(from))); |
| 548 | to->dev = from->dev; |
| 549 | to->mark = from->mark; |
| 550 | |
| 551 | #ifdef CONFIG_NET_SCHED |
| 552 | to->tc_index = from->tc_index; |
| 553 | #endif |
| 554 | nf_copy(to, from); |
| 555 | skb_copy_secmark(to, from); |
| 556 | } |
| 557 | |
| 558 | int ip6_fragment(struct net *net, struct sock *sk, struct sk_buff *skb, |
| 559 | int (*output)(struct net *, struct sock *, struct sk_buff *)) |
| 560 | { |
| 561 | struct sk_buff *frag; |
| 562 | struct rt6_info *rt = (struct rt6_info *)skb_dst(skb); |
| 563 | struct ipv6_pinfo *np = skb->sk && !dev_recursion_level() ? |
| 564 | inet6_sk(skb->sk) : NULL; |
| 565 | struct ipv6hdr *tmp_hdr; |
| 566 | struct frag_hdr *fh; |
| 567 | unsigned int mtu, hlen, left, len; |
| 568 | int hroom, troom; |
| 569 | __be32 frag_id; |
| 570 | int ptr, offset = 0, err = 0; |
| 571 | u8 *prevhdr, nexthdr = 0; |
| 572 | |
| 573 | hlen = ip6_find_1stfragopt(skb, &prevhdr); |
| 574 | nexthdr = *prevhdr; |
| 575 | |
| 576 | mtu = ip6_skb_dst_mtu(skb); |
| 577 | |
| 578 | /* We must not fragment if the socket is set to force MTU discovery |
| 579 | * or if the skb it not generated by a local socket. |
| 580 | */ |
| 581 | if (unlikely(!skb->ignore_df && skb->len > mtu)) |
| 582 | goto fail_toobig; |
| 583 | |
| 584 | if (IP6CB(skb)->frag_max_size) { |
| 585 | if (IP6CB(skb)->frag_max_size > mtu) |
| 586 | goto fail_toobig; |
| 587 | |
| 588 | /* don't send fragments larger than what we received */ |
| 589 | mtu = IP6CB(skb)->frag_max_size; |
| 590 | if (mtu < IPV6_MIN_MTU) |
| 591 | mtu = IPV6_MIN_MTU; |
| 592 | } |
| 593 | |
| 594 | if (np && np->frag_size < mtu) { |
| 595 | if (np->frag_size) |
| 596 | mtu = np->frag_size; |
| 597 | } |
| 598 | if (mtu < hlen + sizeof(struct frag_hdr) + 8) |
| 599 | goto fail_toobig; |
| 600 | mtu -= hlen + sizeof(struct frag_hdr); |
| 601 | |
| 602 | frag_id = ipv6_select_ident(net, &ipv6_hdr(skb)->daddr, |
| 603 | &ipv6_hdr(skb)->saddr); |
| 604 | |
| 605 | if (skb->ip_summed == CHECKSUM_PARTIAL && |
| 606 | (err = skb_checksum_help(skb))) |
| 607 | goto fail; |
| 608 | |
| 609 | hroom = LL_RESERVED_SPACE(rt->dst.dev); |
| 610 | if (skb_has_frag_list(skb)) { |
| 611 | int first_len = skb_pagelen(skb); |
| 612 | struct sk_buff *frag2; |
| 613 | |
| 614 | if (first_len - hlen > mtu || |
| 615 | ((first_len - hlen) & 7) || |
| 616 | skb_cloned(skb) || |
| 617 | skb_headroom(skb) < (hroom + sizeof(struct frag_hdr))) |
| 618 | goto slow_path; |
| 619 | |
| 620 | skb_walk_frags(skb, frag) { |
| 621 | /* Correct geometry. */ |
| 622 | if (frag->len > mtu || |
| 623 | ((frag->len & 7) && frag->next) || |
| 624 | skb_headroom(frag) < (hlen + hroom + sizeof(struct frag_hdr))) |
| 625 | goto slow_path_clean; |
| 626 | |
| 627 | /* Partially cloned skb? */ |
| 628 | if (skb_shared(frag)) |
| 629 | goto slow_path_clean; |
| 630 | |
| 631 | BUG_ON(frag->sk); |
| 632 | if (skb->sk) { |
| 633 | frag->sk = skb->sk; |
| 634 | frag->destructor = sock_wfree; |
| 635 | } |
| 636 | skb->truesize -= frag->truesize; |
| 637 | } |
| 638 | |
| 639 | err = 0; |
| 640 | offset = 0; |
| 641 | /* BUILD HEADER */ |
| 642 | |
| 643 | *prevhdr = NEXTHDR_FRAGMENT; |
| 644 | tmp_hdr = kmemdup(skb_network_header(skb), hlen, GFP_ATOMIC); |
| 645 | if (!tmp_hdr) { |
| 646 | IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), |
| 647 | IPSTATS_MIB_FRAGFAILS); |
| 648 | err = -ENOMEM; |
| 649 | goto fail; |
| 650 | } |
| 651 | frag = skb_shinfo(skb)->frag_list; |
| 652 | skb_frag_list_init(skb); |
| 653 | |
| 654 | __skb_pull(skb, hlen); |
| 655 | fh = (struct frag_hdr *)__skb_push(skb, sizeof(struct frag_hdr)); |
| 656 | __skb_push(skb, hlen); |
| 657 | skb_reset_network_header(skb); |
| 658 | memcpy(skb_network_header(skb), tmp_hdr, hlen); |
| 659 | |
| 660 | fh->nexthdr = nexthdr; |
| 661 | fh->reserved = 0; |
| 662 | fh->frag_off = htons(IP6_MF); |
| 663 | fh->identification = frag_id; |
| 664 | |
| 665 | first_len = skb_pagelen(skb); |
| 666 | skb->data_len = first_len - skb_headlen(skb); |
| 667 | skb->len = first_len; |
| 668 | ipv6_hdr(skb)->payload_len = htons(first_len - |
| 669 | sizeof(struct ipv6hdr)); |
| 670 | |
| 671 | dst_hold(&rt->dst); |
| 672 | |
| 673 | for (;;) { |
| 674 | /* Prepare header of the next frame, |
| 675 | * before previous one went down. */ |
| 676 | if (frag) { |
| 677 | frag->ip_summed = CHECKSUM_NONE; |
| 678 | skb_reset_transport_header(frag); |
| 679 | fh = (struct frag_hdr *)__skb_push(frag, sizeof(struct frag_hdr)); |
| 680 | __skb_push(frag, hlen); |
| 681 | skb_reset_network_header(frag); |
| 682 | memcpy(skb_network_header(frag), tmp_hdr, |
| 683 | hlen); |
| 684 | offset += skb->len - hlen - sizeof(struct frag_hdr); |
| 685 | fh->nexthdr = nexthdr; |
| 686 | fh->reserved = 0; |
| 687 | fh->frag_off = htons(offset); |
| 688 | if (frag->next) |
| 689 | fh->frag_off |= htons(IP6_MF); |
| 690 | fh->identification = frag_id; |
| 691 | ipv6_hdr(frag)->payload_len = |
| 692 | htons(frag->len - |
| 693 | sizeof(struct ipv6hdr)); |
| 694 | ip6_copy_metadata(frag, skb); |
| 695 | } |
| 696 | |
| 697 | err = output(net, sk, skb); |
| 698 | if (!err) |
| 699 | IP6_INC_STATS(net, ip6_dst_idev(&rt->dst), |
| 700 | IPSTATS_MIB_FRAGCREATES); |
| 701 | |
| 702 | if (err || !frag) |
| 703 | break; |
| 704 | |
| 705 | skb = frag; |
| 706 | frag = skb->next; |
| 707 | skb->next = NULL; |
| 708 | } |
| 709 | |
| 710 | kfree(tmp_hdr); |
| 711 | |
| 712 | if (err == 0) { |
| 713 | IP6_INC_STATS(net, ip6_dst_idev(&rt->dst), |
| 714 | IPSTATS_MIB_FRAGOKS); |
| 715 | ip6_rt_put(rt); |
| 716 | return 0; |
| 717 | } |
| 718 | |
| 719 | kfree_skb_list(frag); |
| 720 | |
| 721 | IP6_INC_STATS(net, ip6_dst_idev(&rt->dst), |
| 722 | IPSTATS_MIB_FRAGFAILS); |
| 723 | ip6_rt_put(rt); |
| 724 | return err; |
| 725 | |
| 726 | slow_path_clean: |
| 727 | skb_walk_frags(skb, frag2) { |
| 728 | if (frag2 == frag) |
| 729 | break; |
| 730 | frag2->sk = NULL; |
| 731 | frag2->destructor = NULL; |
| 732 | skb->truesize += frag2->truesize; |
| 733 | } |
| 734 | } |
| 735 | |
| 736 | slow_path: |
| 737 | left = skb->len - hlen; /* Space per frame */ |
| 738 | ptr = hlen; /* Where to start from */ |
| 739 | |
| 740 | /* |
| 741 | * Fragment the datagram. |
| 742 | */ |
| 743 | |
| 744 | *prevhdr = NEXTHDR_FRAGMENT; |
| 745 | troom = rt->dst.dev->needed_tailroom; |
| 746 | |
| 747 | /* |
| 748 | * Keep copying data until we run out. |
| 749 | */ |
| 750 | while (left > 0) { |
| 751 | len = left; |
| 752 | /* IF: it doesn't fit, use 'mtu' - the data space left */ |
| 753 | if (len > mtu) |
| 754 | len = mtu; |
| 755 | /* IF: we are not sending up to and including the packet end |
| 756 | then align the next start on an eight byte boundary */ |
| 757 | if (len < left) { |
| 758 | len &= ~7; |
| 759 | } |
| 760 | |
| 761 | /* Allocate buffer */ |
| 762 | frag = alloc_skb(len + hlen + sizeof(struct frag_hdr) + |
| 763 | hroom + troom, GFP_ATOMIC); |
| 764 | if (!frag) { |
| 765 | IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), |
| 766 | IPSTATS_MIB_FRAGFAILS); |
| 767 | err = -ENOMEM; |
| 768 | goto fail; |
| 769 | } |
| 770 | |
| 771 | /* |
| 772 | * Set up data on packet |
| 773 | */ |
| 774 | |
| 775 | ip6_copy_metadata(frag, skb); |
| 776 | skb_reserve(frag, hroom); |
| 777 | skb_put(frag, len + hlen + sizeof(struct frag_hdr)); |
| 778 | skb_reset_network_header(frag); |
| 779 | fh = (struct frag_hdr *)(skb_network_header(frag) + hlen); |
| 780 | frag->transport_header = (frag->network_header + hlen + |
| 781 | sizeof(struct frag_hdr)); |
| 782 | |
| 783 | /* |
| 784 | * Charge the memory for the fragment to any owner |
| 785 | * it might possess |
| 786 | */ |
| 787 | if (skb->sk) |
| 788 | skb_set_owner_w(frag, skb->sk); |
| 789 | |
| 790 | /* |
| 791 | * Copy the packet header into the new buffer. |
| 792 | */ |
| 793 | skb_copy_from_linear_data(skb, skb_network_header(frag), hlen); |
| 794 | |
| 795 | /* |
| 796 | * Build fragment header. |
| 797 | */ |
| 798 | fh->nexthdr = nexthdr; |
| 799 | fh->reserved = 0; |
| 800 | fh->identification = frag_id; |
| 801 | |
| 802 | /* |
| 803 | * Copy a block of the IP datagram. |
| 804 | */ |
| 805 | BUG_ON(skb_copy_bits(skb, ptr, skb_transport_header(frag), |
| 806 | len)); |
| 807 | left -= len; |
| 808 | |
| 809 | fh->frag_off = htons(offset); |
| 810 | if (left > 0) |
| 811 | fh->frag_off |= htons(IP6_MF); |
| 812 | ipv6_hdr(frag)->payload_len = htons(frag->len - |
| 813 | sizeof(struct ipv6hdr)); |
| 814 | |
| 815 | ptr += len; |
| 816 | offset += len; |
| 817 | |
| 818 | /* |
| 819 | * Put this fragment into the sending queue. |
| 820 | */ |
| 821 | err = output(net, sk, frag); |
| 822 | if (err) |
| 823 | goto fail; |
| 824 | |
| 825 | IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), |
| 826 | IPSTATS_MIB_FRAGCREATES); |
| 827 | } |
| 828 | IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), |
| 829 | IPSTATS_MIB_FRAGOKS); |
| 830 | consume_skb(skb); |
| 831 | return err; |
| 832 | |
| 833 | fail_toobig: |
| 834 | if (skb->sk && dst_allfrag(skb_dst(skb))) |
| 835 | sk_nocaps_add(skb->sk, NETIF_F_GSO_MASK); |
| 836 | |
| 837 | skb->dev = skb_dst(skb)->dev; |
| 838 | icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu); |
| 839 | err = -EMSGSIZE; |
| 840 | |
| 841 | fail: |
| 842 | IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), |
| 843 | IPSTATS_MIB_FRAGFAILS); |
| 844 | kfree_skb(skb); |
| 845 | return err; |
| 846 | } |
| 847 | |
| 848 | static inline int ip6_rt_check(const struct rt6key *rt_key, |
| 849 | const struct in6_addr *fl_addr, |
| 850 | const struct in6_addr *addr_cache) |
| 851 | { |
| 852 | return (rt_key->plen != 128 || !ipv6_addr_equal(fl_addr, &rt_key->addr)) && |
| 853 | (!addr_cache || !ipv6_addr_equal(fl_addr, addr_cache)); |
| 854 | } |
| 855 | |
| 856 | static struct dst_entry *ip6_sk_dst_check(struct sock *sk, |
| 857 | struct dst_entry *dst, |
| 858 | const struct flowi6 *fl6) |
| 859 | { |
| 860 | struct ipv6_pinfo *np = inet6_sk(sk); |
| 861 | struct rt6_info *rt; |
| 862 | |
| 863 | if (!dst) |
| 864 | goto out; |
| 865 | |
| 866 | if (dst->ops->family != AF_INET6) { |
| 867 | dst_release(dst); |
| 868 | return NULL; |
| 869 | } |
| 870 | |
| 871 | rt = (struct rt6_info *)dst; |
| 872 | /* Yes, checking route validity in not connected |
| 873 | * case is not very simple. Take into account, |
| 874 | * that we do not support routing by source, TOS, |
| 875 | * and MSG_DONTROUTE --ANK (980726) |
| 876 | * |
| 877 | * 1. ip6_rt_check(): If route was host route, |
| 878 | * check that cached destination is current. |
| 879 | * If it is network route, we still may |
| 880 | * check its validity using saved pointer |
| 881 | * to the last used address: daddr_cache. |
| 882 | * We do not want to save whole address now, |
| 883 | * (because main consumer of this service |
| 884 | * is tcp, which has not this problem), |
| 885 | * so that the last trick works only on connected |
| 886 | * sockets. |
| 887 | * 2. oif also should be the same. |
| 888 | */ |
| 889 | if (ip6_rt_check(&rt->rt6i_dst, &fl6->daddr, np->daddr_cache) || |
| 890 | #ifdef CONFIG_IPV6_SUBTREES |
| 891 | ip6_rt_check(&rt->rt6i_src, &fl6->saddr, np->saddr_cache) || |
| 892 | #endif |
| 893 | (!(fl6->flowi6_flags & FLOWI_FLAG_SKIP_NH_OIF) && |
| 894 | (fl6->flowi6_oif && fl6->flowi6_oif != dst->dev->ifindex))) { |
| 895 | dst_release(dst); |
| 896 | dst = NULL; |
| 897 | } |
| 898 | |
| 899 | out: |
| 900 | return dst; |
| 901 | } |
| 902 | |
| 903 | static int ip6_dst_lookup_tail(struct net *net, const struct sock *sk, |
| 904 | struct dst_entry **dst, struct flowi6 *fl6) |
| 905 | { |
| 906 | #ifdef CONFIG_IPV6_OPTIMISTIC_DAD |
| 907 | struct neighbour *n; |
| 908 | struct rt6_info *rt; |
| 909 | #endif |
| 910 | int err; |
| 911 | int flags = 0; |
| 912 | |
| 913 | /* The correct way to handle this would be to do |
| 914 | * ip6_route_get_saddr, and then ip6_route_output; however, |
| 915 | * the route-specific preferred source forces the |
| 916 | * ip6_route_output call _before_ ip6_route_get_saddr. |
| 917 | * |
| 918 | * In source specific routing (no src=any default route), |
| 919 | * ip6_route_output will fail given src=any saddr, though, so |
| 920 | * that's why we try it again later. |
| 921 | */ |
| 922 | if (ipv6_addr_any(&fl6->saddr) && (!*dst || !(*dst)->error)) { |
| 923 | struct rt6_info *rt; |
| 924 | bool had_dst = *dst != NULL; |
| 925 | |
| 926 | if (!had_dst) |
| 927 | *dst = ip6_route_output(net, sk, fl6); |
| 928 | rt = (*dst)->error ? NULL : (struct rt6_info *)*dst; |
| 929 | err = ip6_route_get_saddr(net, rt, &fl6->daddr, |
| 930 | sk ? inet6_sk(sk)->srcprefs : 0, |
| 931 | &fl6->saddr); |
| 932 | if (err) |
| 933 | goto out_err_release; |
| 934 | |
| 935 | /* If we had an erroneous initial result, pretend it |
| 936 | * never existed and let the SA-enabled version take |
| 937 | * over. |
| 938 | */ |
| 939 | if (!had_dst && (*dst)->error) { |
| 940 | dst_release(*dst); |
| 941 | *dst = NULL; |
| 942 | } |
| 943 | |
| 944 | if (fl6->flowi6_oif) |
| 945 | flags |= RT6_LOOKUP_F_IFACE; |
| 946 | } |
| 947 | |
| 948 | if (!*dst) |
| 949 | *dst = ip6_route_output_flags(net, sk, fl6, flags); |
| 950 | |
| 951 | err = (*dst)->error; |
| 952 | if (err) |
| 953 | goto out_err_release; |
| 954 | |
| 955 | #ifdef CONFIG_IPV6_OPTIMISTIC_DAD |
| 956 | /* |
| 957 | * Here if the dst entry we've looked up |
| 958 | * has a neighbour entry that is in the INCOMPLETE |
| 959 | * state and the src address from the flow is |
| 960 | * marked as OPTIMISTIC, we release the found |
| 961 | * dst entry and replace it instead with the |
| 962 | * dst entry of the nexthop router |
| 963 | */ |
| 964 | rt = (struct rt6_info *) *dst; |
| 965 | rcu_read_lock_bh(); |
| 966 | n = __ipv6_neigh_lookup_noref(rt->dst.dev, |
| 967 | rt6_nexthop(rt, &fl6->daddr)); |
| 968 | err = n && !(n->nud_state & NUD_VALID) ? -EINVAL : 0; |
| 969 | rcu_read_unlock_bh(); |
| 970 | |
| 971 | if (err) { |
| 972 | struct inet6_ifaddr *ifp; |
| 973 | struct flowi6 fl_gw6; |
| 974 | int redirect; |
| 975 | |
| 976 | ifp = ipv6_get_ifaddr(net, &fl6->saddr, |
| 977 | (*dst)->dev, 1); |
| 978 | |
| 979 | redirect = (ifp && ifp->flags & IFA_F_OPTIMISTIC); |
| 980 | if (ifp) |
| 981 | in6_ifa_put(ifp); |
| 982 | |
| 983 | if (redirect) { |
| 984 | /* |
| 985 | * We need to get the dst entry for the |
| 986 | * default router instead |
| 987 | */ |
| 988 | dst_release(*dst); |
| 989 | memcpy(&fl_gw6, fl6, sizeof(struct flowi6)); |
| 990 | memset(&fl_gw6.daddr, 0, sizeof(struct in6_addr)); |
| 991 | *dst = ip6_route_output(net, sk, &fl_gw6); |
| 992 | err = (*dst)->error; |
| 993 | if (err) |
| 994 | goto out_err_release; |
| 995 | } |
| 996 | } |
| 997 | #endif |
| 998 | |
| 999 | return 0; |
| 1000 | |
| 1001 | out_err_release: |
| 1002 | if (err == -ENETUNREACH) |
| 1003 | IP6_INC_STATS(net, NULL, IPSTATS_MIB_OUTNOROUTES); |
| 1004 | dst_release(*dst); |
| 1005 | *dst = NULL; |
| 1006 | return err; |
| 1007 | } |
| 1008 | |
| 1009 | /** |
| 1010 | * ip6_dst_lookup - perform route lookup on flow |
| 1011 | * @sk: socket which provides route info |
| 1012 | * @dst: pointer to dst_entry * for result |
| 1013 | * @fl6: flow to lookup |
| 1014 | * |
| 1015 | * This function performs a route lookup on the given flow. |
| 1016 | * |
| 1017 | * It returns zero on success, or a standard errno code on error. |
| 1018 | */ |
| 1019 | int ip6_dst_lookup(struct net *net, struct sock *sk, struct dst_entry **dst, |
| 1020 | struct flowi6 *fl6) |
| 1021 | { |
| 1022 | *dst = NULL; |
| 1023 | return ip6_dst_lookup_tail(net, sk, dst, fl6); |
| 1024 | } |
| 1025 | EXPORT_SYMBOL_GPL(ip6_dst_lookup); |
| 1026 | |
| 1027 | /** |
| 1028 | * ip6_dst_lookup_flow - perform route lookup on flow with ipsec |
| 1029 | * @sk: socket which provides route info |
| 1030 | * @fl6: flow to lookup |
| 1031 | * @final_dst: final destination address for ipsec lookup |
| 1032 | * |
| 1033 | * This function performs a route lookup on the given flow. |
| 1034 | * |
| 1035 | * It returns a valid dst pointer on success, or a pointer encoded |
| 1036 | * error code. |
| 1037 | */ |
| 1038 | struct dst_entry *ip6_dst_lookup_flow(const struct sock *sk, struct flowi6 *fl6, |
| 1039 | const struct in6_addr *final_dst) |
| 1040 | { |
| 1041 | struct dst_entry *dst = NULL; |
| 1042 | int err; |
| 1043 | |
| 1044 | err = ip6_dst_lookup_tail(sock_net(sk), sk, &dst, fl6); |
| 1045 | if (err) |
| 1046 | return ERR_PTR(err); |
| 1047 | if (final_dst) |
| 1048 | fl6->daddr = *final_dst; |
| 1049 | if (!fl6->flowi6_oif) |
| 1050 | fl6->flowi6_oif = l3mdev_fib_oif(dst->dev); |
| 1051 | |
| 1052 | return xfrm_lookup_route(sock_net(sk), dst, flowi6_to_flowi(fl6), sk, 0); |
| 1053 | } |
| 1054 | EXPORT_SYMBOL_GPL(ip6_dst_lookup_flow); |
| 1055 | |
| 1056 | /** |
| 1057 | * ip6_sk_dst_lookup_flow - perform socket cached route lookup on flow |
| 1058 | * @sk: socket which provides the dst cache and route info |
| 1059 | * @fl6: flow to lookup |
| 1060 | * @final_dst: final destination address for ipsec lookup |
| 1061 | * |
| 1062 | * This function performs a route lookup on the given flow with the |
| 1063 | * possibility of using the cached route in the socket if it is valid. |
| 1064 | * It will take the socket dst lock when operating on the dst cache. |
| 1065 | * As a result, this function can only be used in process context. |
| 1066 | * |
| 1067 | * It returns a valid dst pointer on success, or a pointer encoded |
| 1068 | * error code. |
| 1069 | */ |
| 1070 | struct dst_entry *ip6_sk_dst_lookup_flow(struct sock *sk, struct flowi6 *fl6, |
| 1071 | const struct in6_addr *final_dst) |
| 1072 | { |
| 1073 | struct dst_entry *dst = sk_dst_check(sk, inet6_sk(sk)->dst_cookie); |
| 1074 | int err; |
| 1075 | |
| 1076 | dst = ip6_sk_dst_check(sk, dst, fl6); |
| 1077 | |
| 1078 | err = ip6_dst_lookup_tail(sock_net(sk), sk, &dst, fl6); |
| 1079 | if (err) |
| 1080 | return ERR_PTR(err); |
| 1081 | if (final_dst) |
| 1082 | fl6->daddr = *final_dst; |
| 1083 | |
| 1084 | return xfrm_lookup_route(sock_net(sk), dst, flowi6_to_flowi(fl6), sk, 0); |
| 1085 | } |
| 1086 | EXPORT_SYMBOL_GPL(ip6_sk_dst_lookup_flow); |
| 1087 | |
| 1088 | static inline int ip6_ufo_append_data(struct sock *sk, |
| 1089 | struct sk_buff_head *queue, |
| 1090 | int getfrag(void *from, char *to, int offset, int len, |
| 1091 | int odd, struct sk_buff *skb), |
| 1092 | void *from, int length, int hh_len, int fragheaderlen, |
| 1093 | int transhdrlen, int mtu, unsigned int flags, |
| 1094 | const struct flowi6 *fl6) |
| 1095 | |
| 1096 | { |
| 1097 | struct sk_buff *skb; |
| 1098 | int err; |
| 1099 | |
| 1100 | /* There is support for UDP large send offload by network |
| 1101 | * device, so create one single skb packet containing complete |
| 1102 | * udp datagram |
| 1103 | */ |
| 1104 | skb = skb_peek_tail(queue); |
| 1105 | if (!skb) { |
| 1106 | skb = sock_alloc_send_skb(sk, |
| 1107 | hh_len + fragheaderlen + transhdrlen + 20, |
| 1108 | (flags & MSG_DONTWAIT), &err); |
| 1109 | if (!skb) |
| 1110 | return err; |
| 1111 | |
| 1112 | /* reserve space for Hardware header */ |
| 1113 | skb_reserve(skb, hh_len); |
| 1114 | |
| 1115 | /* create space for UDP/IP header */ |
| 1116 | skb_put(skb, fragheaderlen + transhdrlen); |
| 1117 | |
| 1118 | /* initialize network header pointer */ |
| 1119 | skb_reset_network_header(skb); |
| 1120 | |
| 1121 | /* initialize protocol header pointer */ |
| 1122 | skb->transport_header = skb->network_header + fragheaderlen; |
| 1123 | |
| 1124 | skb->protocol = htons(ETH_P_IPV6); |
| 1125 | skb->csum = 0; |
| 1126 | |
| 1127 | __skb_queue_tail(queue, skb); |
| 1128 | } else if (skb_is_gso(skb)) { |
| 1129 | goto append; |
| 1130 | } |
| 1131 | |
| 1132 | skb->ip_summed = CHECKSUM_PARTIAL; |
| 1133 | /* Specify the length of each IPv6 datagram fragment. |
| 1134 | * It has to be a multiple of 8. |
| 1135 | */ |
| 1136 | skb_shinfo(skb)->gso_size = (mtu - fragheaderlen - |
| 1137 | sizeof(struct frag_hdr)) & ~7; |
| 1138 | skb_shinfo(skb)->gso_type = SKB_GSO_UDP; |
| 1139 | skb_shinfo(skb)->ip6_frag_id = ipv6_select_ident(sock_net(sk), |
| 1140 | &fl6->daddr, |
| 1141 | &fl6->saddr); |
| 1142 | |
| 1143 | append: |
| 1144 | return skb_append_datato_frags(sk, skb, getfrag, from, |
| 1145 | (length - transhdrlen)); |
| 1146 | } |
| 1147 | |
| 1148 | static inline struct ipv6_opt_hdr *ip6_opt_dup(struct ipv6_opt_hdr *src, |
| 1149 | gfp_t gfp) |
| 1150 | { |
| 1151 | return src ? kmemdup(src, (src->hdrlen + 1) * 8, gfp) : NULL; |
| 1152 | } |
| 1153 | |
| 1154 | static inline struct ipv6_rt_hdr *ip6_rthdr_dup(struct ipv6_rt_hdr *src, |
| 1155 | gfp_t gfp) |
| 1156 | { |
| 1157 | return src ? kmemdup(src, (src->hdrlen + 1) * 8, gfp) : NULL; |
| 1158 | } |
| 1159 | |
| 1160 | static void ip6_append_data_mtu(unsigned int *mtu, |
| 1161 | int *maxfraglen, |
| 1162 | unsigned int fragheaderlen, |
| 1163 | struct sk_buff *skb, |
| 1164 | struct rt6_info *rt, |
| 1165 | unsigned int orig_mtu) |
| 1166 | { |
| 1167 | if (!(rt->dst.flags & DST_XFRM_TUNNEL)) { |
| 1168 | if (!skb) { |
| 1169 | /* first fragment, reserve header_len */ |
| 1170 | *mtu = orig_mtu - rt->dst.header_len; |
| 1171 | |
| 1172 | } else { |
| 1173 | /* |
| 1174 | * this fragment is not first, the headers |
| 1175 | * space is regarded as data space. |
| 1176 | */ |
| 1177 | *mtu = orig_mtu; |
| 1178 | } |
| 1179 | *maxfraglen = ((*mtu - fragheaderlen) & ~7) |
| 1180 | + fragheaderlen - sizeof(struct frag_hdr); |
| 1181 | } |
| 1182 | } |
| 1183 | |
| 1184 | static int ip6_setup_cork(struct sock *sk, struct inet_cork_full *cork, |
| 1185 | struct inet6_cork *v6_cork, |
| 1186 | int hlimit, int tclass, struct ipv6_txoptions *opt, |
| 1187 | struct rt6_info *rt, struct flowi6 *fl6) |
| 1188 | { |
| 1189 | struct ipv6_pinfo *np = inet6_sk(sk); |
| 1190 | unsigned int mtu; |
| 1191 | |
| 1192 | /* |
| 1193 | * setup for corking |
| 1194 | */ |
| 1195 | if (opt) { |
| 1196 | if (WARN_ON(v6_cork->opt)) |
| 1197 | return -EINVAL; |
| 1198 | |
| 1199 | v6_cork->opt = kzalloc(opt->tot_len, sk->sk_allocation); |
| 1200 | if (unlikely(!v6_cork->opt)) |
| 1201 | return -ENOBUFS; |
| 1202 | |
| 1203 | v6_cork->opt->tot_len = opt->tot_len; |
| 1204 | v6_cork->opt->opt_flen = opt->opt_flen; |
| 1205 | v6_cork->opt->opt_nflen = opt->opt_nflen; |
| 1206 | |
| 1207 | v6_cork->opt->dst0opt = ip6_opt_dup(opt->dst0opt, |
| 1208 | sk->sk_allocation); |
| 1209 | if (opt->dst0opt && !v6_cork->opt->dst0opt) |
| 1210 | return -ENOBUFS; |
| 1211 | |
| 1212 | v6_cork->opt->dst1opt = ip6_opt_dup(opt->dst1opt, |
| 1213 | sk->sk_allocation); |
| 1214 | if (opt->dst1opt && !v6_cork->opt->dst1opt) |
| 1215 | return -ENOBUFS; |
| 1216 | |
| 1217 | v6_cork->opt->hopopt = ip6_opt_dup(opt->hopopt, |
| 1218 | sk->sk_allocation); |
| 1219 | if (opt->hopopt && !v6_cork->opt->hopopt) |
| 1220 | return -ENOBUFS; |
| 1221 | |
| 1222 | v6_cork->opt->srcrt = ip6_rthdr_dup(opt->srcrt, |
| 1223 | sk->sk_allocation); |
| 1224 | if (opt->srcrt && !v6_cork->opt->srcrt) |
| 1225 | return -ENOBUFS; |
| 1226 | |
| 1227 | /* need source address above miyazawa*/ |
| 1228 | } |
| 1229 | dst_hold(&rt->dst); |
| 1230 | cork->base.dst = &rt->dst; |
| 1231 | cork->fl.u.ip6 = *fl6; |
| 1232 | v6_cork->hop_limit = hlimit; |
| 1233 | v6_cork->tclass = tclass; |
| 1234 | if (rt->dst.flags & DST_XFRM_TUNNEL) |
| 1235 | mtu = np->pmtudisc >= IPV6_PMTUDISC_PROBE ? |
| 1236 | rt->dst.dev->mtu : dst_mtu(&rt->dst); |
| 1237 | else |
| 1238 | mtu = np->pmtudisc >= IPV6_PMTUDISC_PROBE ? |
| 1239 | rt->dst.dev->mtu : dst_mtu(rt->dst.path); |
| 1240 | if (np->frag_size < mtu) { |
| 1241 | if (np->frag_size) |
| 1242 | mtu = np->frag_size; |
| 1243 | } |
| 1244 | cork->base.fragsize = mtu; |
| 1245 | if (dst_allfrag(rt->dst.path)) |
| 1246 | cork->base.flags |= IPCORK_ALLFRAG; |
| 1247 | cork->base.length = 0; |
| 1248 | |
| 1249 | return 0; |
| 1250 | } |
| 1251 | |
| 1252 | static int __ip6_append_data(struct sock *sk, |
| 1253 | struct flowi6 *fl6, |
| 1254 | struct sk_buff_head *queue, |
| 1255 | struct inet_cork *cork, |
| 1256 | struct inet6_cork *v6_cork, |
| 1257 | struct page_frag *pfrag, |
| 1258 | int getfrag(void *from, char *to, int offset, |
| 1259 | int len, int odd, struct sk_buff *skb), |
| 1260 | void *from, int length, int transhdrlen, |
| 1261 | unsigned int flags, int dontfrag) |
| 1262 | { |
| 1263 | struct sk_buff *skb, *skb_prev = NULL; |
| 1264 | unsigned int maxfraglen, fragheaderlen, mtu, orig_mtu; |
| 1265 | int exthdrlen = 0; |
| 1266 | int dst_exthdrlen = 0; |
| 1267 | int hh_len; |
| 1268 | int copy; |
| 1269 | int err; |
| 1270 | int offset = 0; |
| 1271 | __u8 tx_flags = 0; |
| 1272 | u32 tskey = 0; |
| 1273 | struct rt6_info *rt = (struct rt6_info *)cork->dst; |
| 1274 | struct ipv6_txoptions *opt = v6_cork->opt; |
| 1275 | int csummode = CHECKSUM_NONE; |
| 1276 | unsigned int maxnonfragsize, headersize; |
| 1277 | |
| 1278 | skb = skb_peek_tail(queue); |
| 1279 | if (!skb) { |
| 1280 | exthdrlen = opt ? opt->opt_flen : 0; |
| 1281 | dst_exthdrlen = rt->dst.header_len - rt->rt6i_nfheader_len; |
| 1282 | } |
| 1283 | |
| 1284 | mtu = cork->fragsize; |
| 1285 | orig_mtu = mtu; |
| 1286 | |
| 1287 | hh_len = LL_RESERVED_SPACE(rt->dst.dev); |
| 1288 | |
| 1289 | fragheaderlen = sizeof(struct ipv6hdr) + rt->rt6i_nfheader_len + |
| 1290 | (opt ? opt->opt_nflen : 0); |
| 1291 | maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen - |
| 1292 | sizeof(struct frag_hdr); |
| 1293 | |
| 1294 | headersize = sizeof(struct ipv6hdr) + |
| 1295 | (opt ? opt->opt_flen + opt->opt_nflen : 0) + |
| 1296 | (dst_allfrag(&rt->dst) ? |
| 1297 | sizeof(struct frag_hdr) : 0) + |
| 1298 | rt->rt6i_nfheader_len; |
| 1299 | |
| 1300 | if (cork->length + length > mtu - headersize && dontfrag && |
| 1301 | (sk->sk_protocol == IPPROTO_UDP || |
| 1302 | sk->sk_protocol == IPPROTO_RAW)) { |
| 1303 | ipv6_local_rxpmtu(sk, fl6, mtu - headersize + |
| 1304 | sizeof(struct ipv6hdr)); |
| 1305 | goto emsgsize; |
| 1306 | } |
| 1307 | |
| 1308 | if (ip6_sk_ignore_df(sk)) |
| 1309 | maxnonfragsize = sizeof(struct ipv6hdr) + IPV6_MAXPLEN; |
| 1310 | else |
| 1311 | maxnonfragsize = mtu; |
| 1312 | |
| 1313 | if (cork->length + length > maxnonfragsize - headersize) { |
| 1314 | emsgsize: |
| 1315 | ipv6_local_error(sk, EMSGSIZE, fl6, |
| 1316 | mtu - headersize + |
| 1317 | sizeof(struct ipv6hdr)); |
| 1318 | return -EMSGSIZE; |
| 1319 | } |
| 1320 | |
| 1321 | /* CHECKSUM_PARTIAL only with no extension headers and when |
| 1322 | * we are not going to fragment |
| 1323 | */ |
| 1324 | if (transhdrlen && sk->sk_protocol == IPPROTO_UDP && |
| 1325 | headersize == sizeof(struct ipv6hdr) && |
| 1326 | length < mtu - headersize && |
| 1327 | !(flags & MSG_MORE) && |
| 1328 | rt->dst.dev->features & (NETIF_F_IPV6_CSUM | NETIF_F_HW_CSUM)) |
| 1329 | csummode = CHECKSUM_PARTIAL; |
| 1330 | |
| 1331 | if (sk->sk_type == SOCK_DGRAM || sk->sk_type == SOCK_RAW) { |
| 1332 | sock_tx_timestamp(sk, &tx_flags); |
| 1333 | if (tx_flags & SKBTX_ANY_SW_TSTAMP && |
| 1334 | sk->sk_tsflags & SOF_TIMESTAMPING_OPT_ID) |
| 1335 | tskey = sk->sk_tskey++; |
| 1336 | } |
| 1337 | |
| 1338 | /* |
| 1339 | * Let's try using as much space as possible. |
| 1340 | * Use MTU if total length of the message fits into the MTU. |
| 1341 | * Otherwise, we need to reserve fragment header and |
| 1342 | * fragment alignment (= 8-15 octects, in total). |
| 1343 | * |
| 1344 | * Note that we may need to "move" the data from the tail of |
| 1345 | * of the buffer to the new fragment when we split |
| 1346 | * the message. |
| 1347 | * |
| 1348 | * FIXME: It may be fragmented into multiple chunks |
| 1349 | * at once if non-fragmentable extension headers |
| 1350 | * are too large. |
| 1351 | * --yoshfuji |
| 1352 | */ |
| 1353 | |
| 1354 | cork->length += length; |
| 1355 | if (((length > mtu) || |
| 1356 | (skb && skb_is_gso(skb))) && |
| 1357 | (sk->sk_protocol == IPPROTO_UDP) && |
| 1358 | (rt->dst.dev->features & NETIF_F_UFO) && |
| 1359 | (sk->sk_type == SOCK_DGRAM) && !udp_get_no_check6_tx(sk)) { |
| 1360 | err = ip6_ufo_append_data(sk, queue, getfrag, from, length, |
| 1361 | hh_len, fragheaderlen, |
| 1362 | transhdrlen, mtu, flags, fl6); |
| 1363 | if (err) |
| 1364 | goto error; |
| 1365 | return 0; |
| 1366 | } |
| 1367 | |
| 1368 | if (!skb) |
| 1369 | goto alloc_new_skb; |
| 1370 | |
| 1371 | while (length > 0) { |
| 1372 | /* Check if the remaining data fits into current packet. */ |
| 1373 | copy = (cork->length <= mtu && !(cork->flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - skb->len; |
| 1374 | if (copy < length) |
| 1375 | copy = maxfraglen - skb->len; |
| 1376 | |
| 1377 | if (copy <= 0) { |
| 1378 | char *data; |
| 1379 | unsigned int datalen; |
| 1380 | unsigned int fraglen; |
| 1381 | unsigned int fraggap; |
| 1382 | unsigned int alloclen; |
| 1383 | alloc_new_skb: |
| 1384 | /* There's no room in the current skb */ |
| 1385 | if (skb) |
| 1386 | fraggap = skb->len - maxfraglen; |
| 1387 | else |
| 1388 | fraggap = 0; |
| 1389 | /* update mtu and maxfraglen if necessary */ |
| 1390 | if (!skb || !skb_prev) |
| 1391 | ip6_append_data_mtu(&mtu, &maxfraglen, |
| 1392 | fragheaderlen, skb, rt, |
| 1393 | orig_mtu); |
| 1394 | |
| 1395 | skb_prev = skb; |
| 1396 | |
| 1397 | /* |
| 1398 | * If remaining data exceeds the mtu, |
| 1399 | * we know we need more fragment(s). |
| 1400 | */ |
| 1401 | datalen = length + fraggap; |
| 1402 | |
| 1403 | if (datalen > (cork->length <= mtu && !(cork->flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - fragheaderlen) |
| 1404 | datalen = maxfraglen - fragheaderlen - rt->dst.trailer_len; |
| 1405 | if ((flags & MSG_MORE) && |
| 1406 | !(rt->dst.dev->features&NETIF_F_SG)) |
| 1407 | alloclen = mtu; |
| 1408 | else |
| 1409 | alloclen = datalen + fragheaderlen; |
| 1410 | |
| 1411 | alloclen += dst_exthdrlen; |
| 1412 | |
| 1413 | if (datalen != length + fraggap) { |
| 1414 | /* |
| 1415 | * this is not the last fragment, the trailer |
| 1416 | * space is regarded as data space. |
| 1417 | */ |
| 1418 | datalen += rt->dst.trailer_len; |
| 1419 | } |
| 1420 | |
| 1421 | alloclen += rt->dst.trailer_len; |
| 1422 | fraglen = datalen + fragheaderlen; |
| 1423 | |
| 1424 | /* |
| 1425 | * We just reserve space for fragment header. |
| 1426 | * Note: this may be overallocation if the message |
| 1427 | * (without MSG_MORE) fits into the MTU. |
| 1428 | */ |
| 1429 | alloclen += sizeof(struct frag_hdr); |
| 1430 | |
| 1431 | if (transhdrlen) { |
| 1432 | skb = sock_alloc_send_skb(sk, |
| 1433 | alloclen + hh_len, |
| 1434 | (flags & MSG_DONTWAIT), &err); |
| 1435 | } else { |
| 1436 | skb = NULL; |
| 1437 | if (atomic_read(&sk->sk_wmem_alloc) <= |
| 1438 | 2 * sk->sk_sndbuf) |
| 1439 | skb = sock_wmalloc(sk, |
| 1440 | alloclen + hh_len, 1, |
| 1441 | sk->sk_allocation); |
| 1442 | if (unlikely(!skb)) |
| 1443 | err = -ENOBUFS; |
| 1444 | } |
| 1445 | if (!skb) |
| 1446 | goto error; |
| 1447 | /* |
| 1448 | * Fill in the control structures |
| 1449 | */ |
| 1450 | skb->protocol = htons(ETH_P_IPV6); |
| 1451 | skb->ip_summed = csummode; |
| 1452 | skb->csum = 0; |
| 1453 | /* reserve for fragmentation and ipsec header */ |
| 1454 | skb_reserve(skb, hh_len + sizeof(struct frag_hdr) + |
| 1455 | dst_exthdrlen); |
| 1456 | |
| 1457 | /* Only the initial fragment is time stamped */ |
| 1458 | skb_shinfo(skb)->tx_flags = tx_flags; |
| 1459 | tx_flags = 0; |
| 1460 | skb_shinfo(skb)->tskey = tskey; |
| 1461 | tskey = 0; |
| 1462 | |
| 1463 | /* |
| 1464 | * Find where to start putting bytes |
| 1465 | */ |
| 1466 | data = skb_put(skb, fraglen); |
| 1467 | skb_set_network_header(skb, exthdrlen); |
| 1468 | data += fragheaderlen; |
| 1469 | skb->transport_header = (skb->network_header + |
| 1470 | fragheaderlen); |
| 1471 | if (fraggap) { |
| 1472 | skb->csum = skb_copy_and_csum_bits( |
| 1473 | skb_prev, maxfraglen, |
| 1474 | data + transhdrlen, fraggap, 0); |
| 1475 | skb_prev->csum = csum_sub(skb_prev->csum, |
| 1476 | skb->csum); |
| 1477 | data += fraggap; |
| 1478 | pskb_trim_unique(skb_prev, maxfraglen); |
| 1479 | } |
| 1480 | copy = datalen - transhdrlen - fraggap; |
| 1481 | |
| 1482 | if (copy < 0) { |
| 1483 | err = -EINVAL; |
| 1484 | kfree_skb(skb); |
| 1485 | goto error; |
| 1486 | } else if (copy > 0 && getfrag(from, data + transhdrlen, offset, copy, fraggap, skb) < 0) { |
| 1487 | err = -EFAULT; |
| 1488 | kfree_skb(skb); |
| 1489 | goto error; |
| 1490 | } |
| 1491 | |
| 1492 | offset += copy; |
| 1493 | length -= datalen - fraggap; |
| 1494 | transhdrlen = 0; |
| 1495 | exthdrlen = 0; |
| 1496 | dst_exthdrlen = 0; |
| 1497 | |
| 1498 | /* |
| 1499 | * Put the packet on the pending queue |
| 1500 | */ |
| 1501 | __skb_queue_tail(queue, skb); |
| 1502 | continue; |
| 1503 | } |
| 1504 | |
| 1505 | if (copy > length) |
| 1506 | copy = length; |
| 1507 | |
| 1508 | if (!(rt->dst.dev->features&NETIF_F_SG)) { |
| 1509 | unsigned int off; |
| 1510 | |
| 1511 | off = skb->len; |
| 1512 | if (getfrag(from, skb_put(skb, copy), |
| 1513 | offset, copy, off, skb) < 0) { |
| 1514 | __skb_trim(skb, off); |
| 1515 | err = -EFAULT; |
| 1516 | goto error; |
| 1517 | } |
| 1518 | } else { |
| 1519 | int i = skb_shinfo(skb)->nr_frags; |
| 1520 | |
| 1521 | err = -ENOMEM; |
| 1522 | if (!sk_page_frag_refill(sk, pfrag)) |
| 1523 | goto error; |
| 1524 | |
| 1525 | if (!skb_can_coalesce(skb, i, pfrag->page, |
| 1526 | pfrag->offset)) { |
| 1527 | err = -EMSGSIZE; |
| 1528 | if (i == MAX_SKB_FRAGS) |
| 1529 | goto error; |
| 1530 | |
| 1531 | __skb_fill_page_desc(skb, i, pfrag->page, |
| 1532 | pfrag->offset, 0); |
| 1533 | skb_shinfo(skb)->nr_frags = ++i; |
| 1534 | get_page(pfrag->page); |
| 1535 | } |
| 1536 | copy = min_t(int, copy, pfrag->size - pfrag->offset); |
| 1537 | if (getfrag(from, |
| 1538 | page_address(pfrag->page) + pfrag->offset, |
| 1539 | offset, copy, skb->len, skb) < 0) |
| 1540 | goto error_efault; |
| 1541 | |
| 1542 | pfrag->offset += copy; |
| 1543 | skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], copy); |
| 1544 | skb->len += copy; |
| 1545 | skb->data_len += copy; |
| 1546 | skb->truesize += copy; |
| 1547 | atomic_add(copy, &sk->sk_wmem_alloc); |
| 1548 | } |
| 1549 | offset += copy; |
| 1550 | length -= copy; |
| 1551 | } |
| 1552 | |
| 1553 | return 0; |
| 1554 | |
| 1555 | error_efault: |
| 1556 | err = -EFAULT; |
| 1557 | error: |
| 1558 | cork->length -= length; |
| 1559 | IP6_INC_STATS(sock_net(sk), rt->rt6i_idev, IPSTATS_MIB_OUTDISCARDS); |
| 1560 | return err; |
| 1561 | } |
| 1562 | |
| 1563 | int ip6_append_data(struct sock *sk, |
| 1564 | int getfrag(void *from, char *to, int offset, int len, |
| 1565 | int odd, struct sk_buff *skb), |
| 1566 | void *from, int length, int transhdrlen, int hlimit, |
| 1567 | int tclass, struct ipv6_txoptions *opt, struct flowi6 *fl6, |
| 1568 | struct rt6_info *rt, unsigned int flags, int dontfrag) |
| 1569 | { |
| 1570 | struct inet_sock *inet = inet_sk(sk); |
| 1571 | struct ipv6_pinfo *np = inet6_sk(sk); |
| 1572 | int exthdrlen; |
| 1573 | int err; |
| 1574 | |
| 1575 | if (flags&MSG_PROBE) |
| 1576 | return 0; |
| 1577 | if (skb_queue_empty(&sk->sk_write_queue)) { |
| 1578 | /* |
| 1579 | * setup for corking |
| 1580 | */ |
| 1581 | err = ip6_setup_cork(sk, &inet->cork, &np->cork, hlimit, |
| 1582 | tclass, opt, rt, fl6); |
| 1583 | if (err) |
| 1584 | return err; |
| 1585 | |
| 1586 | exthdrlen = (opt ? opt->opt_flen : 0); |
| 1587 | length += exthdrlen; |
| 1588 | transhdrlen += exthdrlen; |
| 1589 | } else { |
| 1590 | fl6 = &inet->cork.fl.u.ip6; |
| 1591 | transhdrlen = 0; |
| 1592 | } |
| 1593 | |
| 1594 | return __ip6_append_data(sk, fl6, &sk->sk_write_queue, &inet->cork.base, |
| 1595 | &np->cork, sk_page_frag(sk), getfrag, |
| 1596 | from, length, transhdrlen, flags, dontfrag); |
| 1597 | } |
| 1598 | EXPORT_SYMBOL_GPL(ip6_append_data); |
| 1599 | |
| 1600 | static void ip6_cork_release(struct inet_cork_full *cork, |
| 1601 | struct inet6_cork *v6_cork) |
| 1602 | { |
| 1603 | if (v6_cork->opt) { |
| 1604 | kfree(v6_cork->opt->dst0opt); |
| 1605 | kfree(v6_cork->opt->dst1opt); |
| 1606 | kfree(v6_cork->opt->hopopt); |
| 1607 | kfree(v6_cork->opt->srcrt); |
| 1608 | kfree(v6_cork->opt); |
| 1609 | v6_cork->opt = NULL; |
| 1610 | } |
| 1611 | |
| 1612 | if (cork->base.dst) { |
| 1613 | dst_release(cork->base.dst); |
| 1614 | cork->base.dst = NULL; |
| 1615 | cork->base.flags &= ~IPCORK_ALLFRAG; |
| 1616 | } |
| 1617 | memset(&cork->fl, 0, sizeof(cork->fl)); |
| 1618 | } |
| 1619 | |
| 1620 | struct sk_buff *__ip6_make_skb(struct sock *sk, |
| 1621 | struct sk_buff_head *queue, |
| 1622 | struct inet_cork_full *cork, |
| 1623 | struct inet6_cork *v6_cork) |
| 1624 | { |
| 1625 | struct sk_buff *skb, *tmp_skb; |
| 1626 | struct sk_buff **tail_skb; |
| 1627 | struct in6_addr final_dst_buf, *final_dst = &final_dst_buf; |
| 1628 | struct ipv6_pinfo *np = inet6_sk(sk); |
| 1629 | struct net *net = sock_net(sk); |
| 1630 | struct ipv6hdr *hdr; |
| 1631 | struct ipv6_txoptions *opt = v6_cork->opt; |
| 1632 | struct rt6_info *rt = (struct rt6_info *)cork->base.dst; |
| 1633 | struct flowi6 *fl6 = &cork->fl.u.ip6; |
| 1634 | unsigned char proto = fl6->flowi6_proto; |
| 1635 | |
| 1636 | skb = __skb_dequeue(queue); |
| 1637 | if (!skb) |
| 1638 | goto out; |
| 1639 | tail_skb = &(skb_shinfo(skb)->frag_list); |
| 1640 | |
| 1641 | /* move skb->data to ip header from ext header */ |
| 1642 | if (skb->data < skb_network_header(skb)) |
| 1643 | __skb_pull(skb, skb_network_offset(skb)); |
| 1644 | while ((tmp_skb = __skb_dequeue(queue)) != NULL) { |
| 1645 | __skb_pull(tmp_skb, skb_network_header_len(skb)); |
| 1646 | *tail_skb = tmp_skb; |
| 1647 | tail_skb = &(tmp_skb->next); |
| 1648 | skb->len += tmp_skb->len; |
| 1649 | skb->data_len += tmp_skb->len; |
| 1650 | skb->truesize += tmp_skb->truesize; |
| 1651 | tmp_skb->destructor = NULL; |
| 1652 | tmp_skb->sk = NULL; |
| 1653 | } |
| 1654 | |
| 1655 | /* Allow local fragmentation. */ |
| 1656 | skb->ignore_df = ip6_sk_ignore_df(sk); |
| 1657 | |
| 1658 | *final_dst = fl6->daddr; |
| 1659 | __skb_pull(skb, skb_network_header_len(skb)); |
| 1660 | if (opt && opt->opt_flen) |
| 1661 | ipv6_push_frag_opts(skb, opt, &proto); |
| 1662 | if (opt && opt->opt_nflen) |
| 1663 | ipv6_push_nfrag_opts(skb, opt, &proto, &final_dst); |
| 1664 | |
| 1665 | skb_push(skb, sizeof(struct ipv6hdr)); |
| 1666 | skb_reset_network_header(skb); |
| 1667 | hdr = ipv6_hdr(skb); |
| 1668 | |
| 1669 | ip6_flow_hdr(hdr, v6_cork->tclass, |
| 1670 | ip6_make_flowlabel(net, skb, fl6->flowlabel, |
| 1671 | np->autoflowlabel, fl6)); |
| 1672 | hdr->hop_limit = v6_cork->hop_limit; |
| 1673 | hdr->nexthdr = proto; |
| 1674 | hdr->saddr = fl6->saddr; |
| 1675 | hdr->daddr = *final_dst; |
| 1676 | |
| 1677 | skb->priority = sk->sk_priority; |
| 1678 | skb->mark = sk->sk_mark; |
| 1679 | |
| 1680 | skb_dst_set(skb, dst_clone(&rt->dst)); |
| 1681 | IP6_UPD_PO_STATS(net, rt->rt6i_idev, IPSTATS_MIB_OUT, skb->len); |
| 1682 | if (proto == IPPROTO_ICMPV6) { |
| 1683 | struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb)); |
| 1684 | |
| 1685 | ICMP6MSGOUT_INC_STATS(net, idev, icmp6_hdr(skb)->icmp6_type); |
| 1686 | ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTMSGS); |
| 1687 | } |
| 1688 | |
| 1689 | ip6_cork_release(cork, v6_cork); |
| 1690 | out: |
| 1691 | return skb; |
| 1692 | } |
| 1693 | |
| 1694 | int ip6_send_skb(struct sk_buff *skb) |
| 1695 | { |
| 1696 | struct net *net = sock_net(skb->sk); |
| 1697 | struct rt6_info *rt = (struct rt6_info *)skb_dst(skb); |
| 1698 | int err; |
| 1699 | |
| 1700 | err = ip6_local_out(net, skb->sk, skb); |
| 1701 | if (err) { |
| 1702 | if (err > 0) |
| 1703 | err = net_xmit_errno(err); |
| 1704 | if (err) |
| 1705 | IP6_INC_STATS(net, rt->rt6i_idev, |
| 1706 | IPSTATS_MIB_OUTDISCARDS); |
| 1707 | } |
| 1708 | |
| 1709 | return err; |
| 1710 | } |
| 1711 | |
| 1712 | int ip6_push_pending_frames(struct sock *sk) |
| 1713 | { |
| 1714 | struct sk_buff *skb; |
| 1715 | |
| 1716 | skb = ip6_finish_skb(sk); |
| 1717 | if (!skb) |
| 1718 | return 0; |
| 1719 | |
| 1720 | return ip6_send_skb(skb); |
| 1721 | } |
| 1722 | EXPORT_SYMBOL_GPL(ip6_push_pending_frames); |
| 1723 | |
| 1724 | static void __ip6_flush_pending_frames(struct sock *sk, |
| 1725 | struct sk_buff_head *queue, |
| 1726 | struct inet_cork_full *cork, |
| 1727 | struct inet6_cork *v6_cork) |
| 1728 | { |
| 1729 | struct sk_buff *skb; |
| 1730 | |
| 1731 | while ((skb = __skb_dequeue_tail(queue)) != NULL) { |
| 1732 | if (skb_dst(skb)) |
| 1733 | IP6_INC_STATS(sock_net(sk), ip6_dst_idev(skb_dst(skb)), |
| 1734 | IPSTATS_MIB_OUTDISCARDS); |
| 1735 | kfree_skb(skb); |
| 1736 | } |
| 1737 | |
| 1738 | ip6_cork_release(cork, v6_cork); |
| 1739 | } |
| 1740 | |
| 1741 | void ip6_flush_pending_frames(struct sock *sk) |
| 1742 | { |
| 1743 | __ip6_flush_pending_frames(sk, &sk->sk_write_queue, |
| 1744 | &inet_sk(sk)->cork, &inet6_sk(sk)->cork); |
| 1745 | } |
| 1746 | EXPORT_SYMBOL_GPL(ip6_flush_pending_frames); |
| 1747 | |
| 1748 | struct sk_buff *ip6_make_skb(struct sock *sk, |
| 1749 | int getfrag(void *from, char *to, int offset, |
| 1750 | int len, int odd, struct sk_buff *skb), |
| 1751 | void *from, int length, int transhdrlen, |
| 1752 | int hlimit, int tclass, |
| 1753 | struct ipv6_txoptions *opt, struct flowi6 *fl6, |
| 1754 | struct rt6_info *rt, unsigned int flags, |
| 1755 | int dontfrag) |
| 1756 | { |
| 1757 | struct inet_cork_full cork; |
| 1758 | struct inet6_cork v6_cork; |
| 1759 | struct sk_buff_head queue; |
| 1760 | int exthdrlen = (opt ? opt->opt_flen : 0); |
| 1761 | int err; |
| 1762 | |
| 1763 | if (flags & MSG_PROBE) |
| 1764 | return NULL; |
| 1765 | |
| 1766 | __skb_queue_head_init(&queue); |
| 1767 | |
| 1768 | cork.base.flags = 0; |
| 1769 | cork.base.addr = 0; |
| 1770 | cork.base.opt = NULL; |
| 1771 | v6_cork.opt = NULL; |
| 1772 | err = ip6_setup_cork(sk, &cork, &v6_cork, hlimit, tclass, opt, rt, fl6); |
| 1773 | if (err) |
| 1774 | return ERR_PTR(err); |
| 1775 | |
| 1776 | if (dontfrag < 0) |
| 1777 | dontfrag = inet6_sk(sk)->dontfrag; |
| 1778 | |
| 1779 | err = __ip6_append_data(sk, fl6, &queue, &cork.base, &v6_cork, |
| 1780 | ¤t->task_frag, getfrag, from, |
| 1781 | length + exthdrlen, transhdrlen + exthdrlen, |
| 1782 | flags, dontfrag); |
| 1783 | if (err) { |
| 1784 | __ip6_flush_pending_frames(sk, &queue, &cork, &v6_cork); |
| 1785 | return ERR_PTR(err); |
| 1786 | } |
| 1787 | |
| 1788 | return __ip6_make_skb(sk, &queue, &cork, &v6_cork); |
| 1789 | } |