linux/net/ipv6/udp.c
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   1/*
   2 *      UDP over IPv6
   3 *      Linux INET6 implementation
   4 *
   5 *      Authors:
   6 *      Pedro Roque             <roque@di.fc.ul.pt>
   7 *
   8 *      Based on linux/ipv4/udp.c
   9 *
  10 *      Fixes:
  11 *      Hideaki YOSHIFUJI       :       sin6_scope_id support
  12 *      YOSHIFUJI Hideaki @USAGI and:   Support IPV6_V6ONLY socket option, which
  13 *      Alexey Kuznetsov                allow both IPv4 and IPv6 sockets to bind
  14 *                                      a single port at the same time.
  15 *      Kazunori MIYAZAWA @USAGI:       change process style to use ip6_append_data
  16 *      YOSHIFUJI Hideaki @USAGI:       convert /proc/net/udp6 to seq_file.
  17 *
  18 *      This program is free software; you can redistribute it and/or
  19 *      modify it under the terms of the GNU General Public License
  20 *      as published by the Free Software Foundation; either version
  21 *      2 of the License, or (at your option) any later version.
  22 */
  23
  24#include <linux/errno.h>
  25#include <linux/types.h>
  26#include <linux/socket.h>
  27#include <linux/sockios.h>
  28#include <linux/net.h>
  29#include <linux/in6.h>
  30#include <linux/netdevice.h>
  31#include <linux/if_arp.h>
  32#include <linux/ipv6.h>
  33#include <linux/icmpv6.h>
  34#include <linux/init.h>
  35#include <linux/module.h>
  36#include <linux/skbuff.h>
  37#include <linux/slab.h>
  38#include <asm/uaccess.h>
  39
  40#include <net/ndisc.h>
  41#include <net/protocol.h>
  42#include <net/transp_v6.h>
  43#include <net/ip6_route.h>
  44#include <net/raw.h>
  45#include <net/tcp_states.h>
  46#include <net/ip6_checksum.h>
  47#include <net/xfrm.h>
  48#include <net/inet6_hashtables.h>
  49#include <net/busy_poll.h>
  50
  51#include <linux/proc_fs.h>
  52#include <linux/seq_file.h>
  53#include <trace/events/skb.h>
  54#include "udp_impl.h"
  55
  56static u32 udp6_ehashfn(const struct net *net,
  57                        const struct in6_addr *laddr,
  58                        const u16 lport,
  59                        const struct in6_addr *faddr,
  60                        const __be16 fport)
  61{
  62        static u32 udp6_ehash_secret __read_mostly;
  63        static u32 udp_ipv6_hash_secret __read_mostly;
  64
  65        u32 lhash, fhash;
  66
  67        net_get_random_once(&udp6_ehash_secret,
  68                            sizeof(udp6_ehash_secret));
  69        net_get_random_once(&udp_ipv6_hash_secret,
  70                            sizeof(udp_ipv6_hash_secret));
  71
  72        lhash = (__force u32)laddr->s6_addr32[3];
  73        fhash = __ipv6_addr_jhash(faddr, udp_ipv6_hash_secret);
  74
  75        return __inet6_ehashfn(lhash, lport, fhash, fport,
  76                               udp_ipv6_hash_secret + net_hash_mix(net));
  77}
  78
  79int ipv6_rcv_saddr_equal(const struct sock *sk, const struct sock *sk2)
  80{
  81        const struct in6_addr *sk2_rcv_saddr6 = inet6_rcv_saddr(sk2);
  82        int sk2_ipv6only = inet_v6_ipv6only(sk2);
  83        int addr_type = ipv6_addr_type(&sk->sk_v6_rcv_saddr);
  84        int addr_type2 = sk2_rcv_saddr6 ? ipv6_addr_type(sk2_rcv_saddr6) : IPV6_ADDR_MAPPED;
  85
  86        /* if both are mapped, treat as IPv4 */
  87        if (addr_type == IPV6_ADDR_MAPPED && addr_type2 == IPV6_ADDR_MAPPED)
  88                return (!sk2_ipv6only &&
  89                        (!sk->sk_rcv_saddr || !sk2->sk_rcv_saddr ||
  90                          sk->sk_rcv_saddr == sk2->sk_rcv_saddr));
  91
  92        if (addr_type2 == IPV6_ADDR_ANY &&
  93            !(sk2_ipv6only && addr_type == IPV6_ADDR_MAPPED))
  94                return 1;
  95
  96        if (addr_type == IPV6_ADDR_ANY &&
  97            !(ipv6_only_sock(sk) && addr_type2 == IPV6_ADDR_MAPPED))
  98                return 1;
  99
 100        if (sk2_rcv_saddr6 &&
 101            ipv6_addr_equal(&sk->sk_v6_rcv_saddr, sk2_rcv_saddr6))
 102                return 1;
 103
 104        return 0;
 105}
 106
 107static u32 udp6_portaddr_hash(const struct net *net,
 108                              const struct in6_addr *addr6,
 109                              unsigned int port)
 110{
 111        unsigned int hash, mix = net_hash_mix(net);
 112
 113        if (ipv6_addr_any(addr6))
 114                hash = jhash_1word(0, mix);
 115        else if (ipv6_addr_v4mapped(addr6))
 116                hash = jhash_1word((__force u32)addr6->s6_addr32[3], mix);
 117        else
 118                hash = jhash2((__force u32 *)addr6->s6_addr32, 4, mix);
 119
 120        return hash ^ port;
 121}
 122
 123int udp_v6_get_port(struct sock *sk, unsigned short snum)
 124{
 125        unsigned int hash2_nulladdr =
 126                udp6_portaddr_hash(sock_net(sk), &in6addr_any, snum);
 127        unsigned int hash2_partial =
 128                udp6_portaddr_hash(sock_net(sk), &sk->sk_v6_rcv_saddr, 0);
 129
 130        /* precompute partial secondary hash */
 131        udp_sk(sk)->udp_portaddr_hash = hash2_partial;
 132        return udp_lib_get_port(sk, snum, ipv6_rcv_saddr_equal, hash2_nulladdr);
 133}
 134
 135static void udp_v6_rehash(struct sock *sk)
 136{
 137        u16 new_hash = udp6_portaddr_hash(sock_net(sk),
 138                                          &sk->sk_v6_rcv_saddr,
 139                                          inet_sk(sk)->inet_num);
 140
 141        udp_lib_rehash(sk, new_hash);
 142}
 143
 144static inline int compute_score(struct sock *sk, struct net *net,
 145                                unsigned short hnum,
 146                                const struct in6_addr *saddr, __be16 sport,
 147                                const struct in6_addr *daddr, __be16 dport,
 148                                int dif)
 149{
 150        int score;
 151        struct inet_sock *inet;
 152
 153        if (!net_eq(sock_net(sk), net) ||
 154            udp_sk(sk)->udp_port_hash != hnum ||
 155            sk->sk_family != PF_INET6)
 156                return -1;
 157
 158        score = 0;
 159        inet = inet_sk(sk);
 160
 161        if (inet->inet_dport) {
 162                if (inet->inet_dport != sport)
 163                        return -1;
 164                score++;
 165        }
 166
 167        if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr)) {
 168                if (!ipv6_addr_equal(&sk->sk_v6_rcv_saddr, daddr))
 169                        return -1;
 170                score++;
 171        }
 172
 173        if (!ipv6_addr_any(&sk->sk_v6_daddr)) {
 174                if (!ipv6_addr_equal(&sk->sk_v6_daddr, saddr))
 175                        return -1;
 176                score++;
 177        }
 178
 179        if (sk->sk_bound_dev_if) {
 180                if (sk->sk_bound_dev_if != dif)
 181                        return -1;
 182                score++;
 183        }
 184
 185        return score;
 186}
 187
 188#define SCORE2_MAX (1 + 1 + 1)
 189static inline int compute_score2(struct sock *sk, struct net *net,
 190                                 const struct in6_addr *saddr, __be16 sport,
 191                                 const struct in6_addr *daddr,
 192                                 unsigned short hnum, int dif)
 193{
 194        int score;
 195        struct inet_sock *inet;
 196
 197        if (!net_eq(sock_net(sk), net) ||
 198            udp_sk(sk)->udp_port_hash != hnum ||
 199            sk->sk_family != PF_INET6)
 200                return -1;
 201
 202        if (!ipv6_addr_equal(&sk->sk_v6_rcv_saddr, daddr))
 203                return -1;
 204
 205        score = 0;
 206        inet = inet_sk(sk);
 207
 208        if (inet->inet_dport) {
 209                if (inet->inet_dport != sport)
 210                        return -1;
 211                score++;
 212        }
 213
 214        if (!ipv6_addr_any(&sk->sk_v6_daddr)) {
 215                if (!ipv6_addr_equal(&sk->sk_v6_daddr, saddr))
 216                        return -1;
 217                score++;
 218        }
 219
 220        if (sk->sk_bound_dev_if) {
 221                if (sk->sk_bound_dev_if != dif)
 222                        return -1;
 223                score++;
 224        }
 225
 226        return score;
 227}
 228
 229/* called with read_rcu_lock() */
 230static struct sock *udp6_lib_lookup2(struct net *net,
 231                const struct in6_addr *saddr, __be16 sport,
 232                const struct in6_addr *daddr, unsigned int hnum, int dif,
 233                struct udp_hslot *hslot2, unsigned int slot2)
 234{
 235        struct sock *sk, *result;
 236        struct hlist_nulls_node *node;
 237        int score, badness, matches = 0, reuseport = 0;
 238        u32 hash = 0;
 239
 240begin:
 241        result = NULL;
 242        badness = -1;
 243        udp_portaddr_for_each_entry_rcu(sk, node, &hslot2->head) {
 244                score = compute_score2(sk, net, saddr, sport,
 245                                      daddr, hnum, dif);
 246                if (score > badness) {
 247                        result = sk;
 248                        badness = score;
 249                        reuseport = sk->sk_reuseport;
 250                        if (reuseport) {
 251                                hash = udp6_ehashfn(net, daddr, hnum,
 252                                                    saddr, sport);
 253                                matches = 1;
 254                        } else if (score == SCORE2_MAX)
 255                                goto exact_match;
 256                } else if (score == badness && reuseport) {
 257                        matches++;
 258                        if (reciprocal_scale(hash, matches) == 0)
 259                                result = sk;
 260                        hash = next_pseudo_random32(hash);
 261                }
 262        }
 263        /*
 264         * if the nulls value we got at the end of this lookup is
 265         * not the expected one, we must restart lookup.
 266         * We probably met an item that was moved to another chain.
 267         */
 268        if (get_nulls_value(node) != slot2)
 269                goto begin;
 270
 271        if (result) {
 272exact_match:
 273                if (unlikely(!atomic_inc_not_zero_hint(&result->sk_refcnt, 2)))
 274                        result = NULL;
 275                else if (unlikely(compute_score2(result, net, saddr, sport,
 276                                  daddr, hnum, dif) < badness)) {
 277                        sock_put(result);
 278                        goto begin;
 279                }
 280        }
 281        return result;
 282}
 283
 284struct sock *__udp6_lib_lookup(struct net *net,
 285                                      const struct in6_addr *saddr, __be16 sport,
 286                                      const struct in6_addr *daddr, __be16 dport,
 287                                      int dif, struct udp_table *udptable)
 288{
 289        struct sock *sk, *result;
 290        struct hlist_nulls_node *node;
 291        unsigned short hnum = ntohs(dport);
 292        unsigned int hash2, slot2, slot = udp_hashfn(net, hnum, udptable->mask);
 293        struct udp_hslot *hslot2, *hslot = &udptable->hash[slot];
 294        int score, badness, matches = 0, reuseport = 0;
 295        u32 hash = 0;
 296
 297        rcu_read_lock();
 298        if (hslot->count > 10) {
 299                hash2 = udp6_portaddr_hash(net, daddr, hnum);
 300                slot2 = hash2 & udptable->mask;
 301                hslot2 = &udptable->hash2[slot2];
 302                if (hslot->count < hslot2->count)
 303                        goto begin;
 304
 305                result = udp6_lib_lookup2(net, saddr, sport,
 306                                          daddr, hnum, dif,
 307                                          hslot2, slot2);
 308                if (!result) {
 309                        hash2 = udp6_portaddr_hash(net, &in6addr_any, hnum);
 310                        slot2 = hash2 & udptable->mask;
 311                        hslot2 = &udptable->hash2[slot2];
 312                        if (hslot->count < hslot2->count)
 313                                goto begin;
 314
 315                        result = udp6_lib_lookup2(net, saddr, sport,
 316                                                  &in6addr_any, hnum, dif,
 317                                                  hslot2, slot2);
 318                }
 319                rcu_read_unlock();
 320                return result;
 321        }
 322begin:
 323        result = NULL;
 324        badness = -1;
 325        sk_nulls_for_each_rcu(sk, node, &hslot->head) {
 326                score = compute_score(sk, net, hnum, saddr, sport, daddr, dport, dif);
 327                if (score > badness) {
 328                        result = sk;
 329                        badness = score;
 330                        reuseport = sk->sk_reuseport;
 331                        if (reuseport) {
 332                                hash = udp6_ehashfn(net, daddr, hnum,
 333                                                    saddr, sport);
 334                                matches = 1;
 335                        }
 336                } else if (score == badness && reuseport) {
 337                        matches++;
 338                        if (reciprocal_scale(hash, matches) == 0)
 339                                result = sk;
 340                        hash = next_pseudo_random32(hash);
 341                }
 342        }
 343        /*
 344         * if the nulls value we got at the end of this lookup is
 345         * not the expected one, we must restart lookup.
 346         * We probably met an item that was moved to another chain.
 347         */
 348        if (get_nulls_value(node) != slot)
 349                goto begin;
 350
 351        if (result) {
 352                if (unlikely(!atomic_inc_not_zero_hint(&result->sk_refcnt, 2)))
 353                        result = NULL;
 354                else if (unlikely(compute_score(result, net, hnum, saddr, sport,
 355                                        daddr, dport, dif) < badness)) {
 356                        sock_put(result);
 357                        goto begin;
 358                }
 359        }
 360        rcu_read_unlock();
 361        return result;
 362}
 363EXPORT_SYMBOL_GPL(__udp6_lib_lookup);
 364
 365static struct sock *__udp6_lib_lookup_skb(struct sk_buff *skb,
 366                                          __be16 sport, __be16 dport,
 367                                          struct udp_table *udptable)
 368{
 369        struct sock *sk;
 370        const struct ipv6hdr *iph = ipv6_hdr(skb);
 371
 372        sk = skb_steal_sock(skb);
 373        if (unlikely(sk))
 374                return sk;
 375        return __udp6_lib_lookup(dev_net(skb_dst(skb)->dev), &iph->saddr, sport,
 376                                 &iph->daddr, dport, inet6_iif(skb),
 377                                 udptable);
 378}
 379
 380struct sock *udp6_lib_lookup(struct net *net, const struct in6_addr *saddr, __be16 sport,
 381                             const struct in6_addr *daddr, __be16 dport, int dif)
 382{
 383        return __udp6_lib_lookup(net, saddr, sport, daddr, dport, dif, &udp_table);
 384}
 385EXPORT_SYMBOL_GPL(udp6_lib_lookup);
 386
 387/*
 388 *      This should be easy, if there is something there we
 389 *      return it, otherwise we block.
 390 */
 391
 392int udpv6_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
 393                  int noblock, int flags, int *addr_len)
 394{
 395        struct ipv6_pinfo *np = inet6_sk(sk);
 396        struct inet_sock *inet = inet_sk(sk);
 397        struct sk_buff *skb;
 398        unsigned int ulen, copied;
 399        int peeked, off = 0;
 400        int err;
 401        int is_udplite = IS_UDPLITE(sk);
 402        int is_udp4;
 403        bool slow;
 404
 405        if (flags & MSG_ERRQUEUE)
 406                return ipv6_recv_error(sk, msg, len, addr_len);
 407
 408        if (np->rxpmtu && np->rxopt.bits.rxpmtu)
 409                return ipv6_recv_rxpmtu(sk, msg, len, addr_len);
 410
 411try_again:
 412        skb = __skb_recv_datagram(sk, flags | (noblock ? MSG_DONTWAIT : 0),
 413                                  &peeked, &off, &err);
 414        if (!skb)
 415                goto out;
 416
 417        ulen = skb->len - sizeof(struct udphdr);
 418        copied = len;
 419        if (copied > ulen)
 420                copied = ulen;
 421        else if (copied < ulen)
 422                msg->msg_flags |= MSG_TRUNC;
 423
 424        is_udp4 = (skb->protocol == htons(ETH_P_IP));
 425
 426        /*
 427         * If checksum is needed at all, try to do it while copying the
 428         * data.  If the data is truncated, or if we only want a partial
 429         * coverage checksum (UDP-Lite), do it before the copy.
 430         */
 431
 432        if (copied < ulen || UDP_SKB_CB(skb)->partial_cov) {
 433                if (udp_lib_checksum_complete(skb))
 434                        goto csum_copy_err;
 435        }
 436
 437        if (skb_csum_unnecessary(skb))
 438                err = skb_copy_datagram_msg(skb, sizeof(struct udphdr),
 439                                            msg, copied);
 440        else {
 441                err = skb_copy_and_csum_datagram_msg(skb, sizeof(struct udphdr), msg);
 442                if (err == -EINVAL)
 443                        goto csum_copy_err;
 444        }
 445        if (unlikely(err)) {
 446                trace_kfree_skb(skb, udpv6_recvmsg);
 447                if (!peeked) {
 448                        atomic_inc(&sk->sk_drops);
 449                        if (is_udp4)
 450                                UDP_INC_STATS_USER(sock_net(sk),
 451                                                   UDP_MIB_INERRORS,
 452                                                   is_udplite);
 453                        else
 454                                UDP6_INC_STATS_USER(sock_net(sk),
 455                                                    UDP_MIB_INERRORS,
 456                                                    is_udplite);
 457                }
 458                goto out_free;
 459        }
 460        if (!peeked) {
 461                if (is_udp4)
 462                        UDP_INC_STATS_USER(sock_net(sk),
 463                                        UDP_MIB_INDATAGRAMS, is_udplite);
 464                else
 465                        UDP6_INC_STATS_USER(sock_net(sk),
 466                                        UDP_MIB_INDATAGRAMS, is_udplite);
 467        }
 468
 469        sock_recv_ts_and_drops(msg, sk, skb);
 470
 471        /* Copy the address. */
 472        if (msg->msg_name) {
 473                DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name);
 474                sin6->sin6_family = AF_INET6;
 475                sin6->sin6_port = udp_hdr(skb)->source;
 476                sin6->sin6_flowinfo = 0;
 477
 478                if (is_udp4) {
 479                        ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr,
 480                                               &sin6->sin6_addr);
 481                        sin6->sin6_scope_id = 0;
 482                } else {
 483                        sin6->sin6_addr = ipv6_hdr(skb)->saddr;
 484                        sin6->sin6_scope_id =
 485                                ipv6_iface_scope_id(&sin6->sin6_addr,
 486                                                    inet6_iif(skb));
 487                }
 488                *addr_len = sizeof(*sin6);
 489        }
 490
 491        if (np->rxopt.all)
 492                ip6_datagram_recv_common_ctl(sk, msg, skb);
 493
 494        if (is_udp4) {
 495                if (inet->cmsg_flags)
 496                        ip_cmsg_recv(msg, skb);
 497        } else {
 498                if (np->rxopt.all)
 499                        ip6_datagram_recv_specific_ctl(sk, msg, skb);
 500        }
 501
 502        err = copied;
 503        if (flags & MSG_TRUNC)
 504                err = ulen;
 505
 506out_free:
 507        skb_free_datagram_locked(sk, skb);
 508out:
 509        return err;
 510
 511csum_copy_err:
 512        slow = lock_sock_fast(sk);
 513        if (!skb_kill_datagram(sk, skb, flags)) {
 514                if (is_udp4) {
 515                        UDP_INC_STATS_USER(sock_net(sk),
 516                                        UDP_MIB_CSUMERRORS, is_udplite);
 517                        UDP_INC_STATS_USER(sock_net(sk),
 518                                        UDP_MIB_INERRORS, is_udplite);
 519                } else {
 520                        UDP6_INC_STATS_USER(sock_net(sk),
 521                                        UDP_MIB_CSUMERRORS, is_udplite);
 522                        UDP6_INC_STATS_USER(sock_net(sk),
 523                                        UDP_MIB_INERRORS, is_udplite);
 524                }
 525        }
 526        unlock_sock_fast(sk, slow);
 527
 528        /* starting over for a new packet, but check if we need to yield */
 529        cond_resched();
 530        msg->msg_flags &= ~MSG_TRUNC;
 531        goto try_again;
 532}
 533
 534void __udp6_lib_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 535                    u8 type, u8 code, int offset, __be32 info,
 536                    struct udp_table *udptable)
 537{
 538        struct ipv6_pinfo *np;
 539        const struct ipv6hdr *hdr = (const struct ipv6hdr *)skb->data;
 540        const struct in6_addr *saddr = &hdr->saddr;
 541        const struct in6_addr *daddr = &hdr->daddr;
 542        struct udphdr *uh = (struct udphdr *)(skb->data+offset);
 543        struct sock *sk;
 544        int err;
 545        struct net *net = dev_net(skb->dev);
 546
 547        sk = __udp6_lib_lookup(net, daddr, uh->dest,
 548                               saddr, uh->source, inet6_iif(skb), udptable);
 549        if (!sk) {
 550                ICMP6_INC_STATS_BH(net, __in6_dev_get(skb->dev),
 551                                   ICMP6_MIB_INERRORS);
 552                return;
 553        }
 554
 555        if (type == ICMPV6_PKT_TOOBIG) {
 556                if (!ip6_sk_accept_pmtu(sk))
 557                        goto out;
 558                ip6_sk_update_pmtu(skb, sk, info);
 559        }
 560        if (type == NDISC_REDIRECT) {
 561                ip6_sk_redirect(skb, sk);
 562                goto out;
 563        }
 564
 565        np = inet6_sk(sk);
 566
 567        if (!icmpv6_err_convert(type, code, &err) && !np->recverr)
 568                goto out;
 569
 570        if (sk->sk_state != TCP_ESTABLISHED && !np->recverr)
 571                goto out;
 572
 573        if (np->recverr)
 574                ipv6_icmp_error(sk, skb, err, uh->dest, ntohl(info), (u8 *)(uh+1));
 575
 576        sk->sk_err = err;
 577        sk->sk_error_report(sk);
 578out:
 579        sock_put(sk);
 580}
 581
 582static int __udpv6_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
 583{
 584        int rc;
 585
 586        if (!ipv6_addr_any(&sk->sk_v6_daddr)) {
 587                sock_rps_save_rxhash(sk, skb);
 588                sk_mark_napi_id(sk, skb);
 589                sk_incoming_cpu_update(sk);
 590        }
 591
 592        rc = sock_queue_rcv_skb(sk, skb);
 593        if (rc < 0) {
 594                int is_udplite = IS_UDPLITE(sk);
 595
 596                /* Note that an ENOMEM error is charged twice */
 597                if (rc == -ENOMEM)
 598                        UDP6_INC_STATS_BH(sock_net(sk),
 599                                        UDP_MIB_RCVBUFERRORS, is_udplite);
 600                UDP6_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
 601                kfree_skb(skb);
 602                return -1;
 603        }
 604        return 0;
 605}
 606
 607static __inline__ void udpv6_err(struct sk_buff *skb,
 608                                 struct inet6_skb_parm *opt, u8 type,
 609                                 u8 code, int offset, __be32 info)
 610{
 611        __udp6_lib_err(skb, opt, type, code, offset, info, &udp_table);
 612}
 613
 614static struct static_key udpv6_encap_needed __read_mostly;
 615void udpv6_encap_enable(void)
 616{
 617        if (!static_key_enabled(&udpv6_encap_needed))
 618                static_key_slow_inc(&udpv6_encap_needed);
 619}
 620EXPORT_SYMBOL(udpv6_encap_enable);
 621
 622int udpv6_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
 623{
 624        struct udp_sock *up = udp_sk(sk);
 625        int rc;
 626        int is_udplite = IS_UDPLITE(sk);
 627
 628        if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
 629                goto drop;
 630
 631        if (static_key_false(&udpv6_encap_needed) && up->encap_type) {
 632                int (*encap_rcv)(struct sock *sk, struct sk_buff *skb);
 633
 634                /*
 635                 * This is an encapsulation socket so pass the skb to
 636                 * the socket's udp_encap_rcv() hook. Otherwise, just
 637                 * fall through and pass this up the UDP socket.
 638                 * up->encap_rcv() returns the following value:
 639                 * =0 if skb was successfully passed to the encap
 640                 *    handler or was discarded by it.
 641                 * >0 if skb should be passed on to UDP.
 642                 * <0 if skb should be resubmitted as proto -N
 643                 */
 644
 645                /* if we're overly short, let UDP handle it */
 646                encap_rcv = ACCESS_ONCE(up->encap_rcv);
 647                if (skb->len > sizeof(struct udphdr) && encap_rcv) {
 648                        int ret;
 649
 650                        /* Verify checksum before giving to encap */
 651                        if (udp_lib_checksum_complete(skb))
 652                                goto csum_error;
 653
 654                        ret = encap_rcv(sk, skb);
 655                        if (ret <= 0) {
 656                                UDP_INC_STATS_BH(sock_net(sk),
 657                                                 UDP_MIB_INDATAGRAMS,
 658                                                 is_udplite);
 659                                return -ret;
 660                        }
 661                }
 662
 663                /* FALLTHROUGH -- it's a UDP Packet */
 664        }
 665
 666        /*
 667         * UDP-Lite specific tests, ignored on UDP sockets (see net/ipv4/udp.c).
 668         */
 669        if ((is_udplite & UDPLITE_RECV_CC)  &&  UDP_SKB_CB(skb)->partial_cov) {
 670
 671                if (up->pcrlen == 0) {          /* full coverage was set  */
 672                        net_dbg_ratelimited("UDPLITE6: partial coverage %d while full coverage %d requested\n",
 673                                            UDP_SKB_CB(skb)->cscov, skb->len);
 674                        goto drop;
 675                }
 676                if (UDP_SKB_CB(skb)->cscov  <  up->pcrlen) {
 677                        net_dbg_ratelimited("UDPLITE6: coverage %d too small, need min %d\n",
 678                                            UDP_SKB_CB(skb)->cscov, up->pcrlen);
 679                        goto drop;
 680                }
 681        }
 682
 683        if (rcu_access_pointer(sk->sk_filter)) {
 684                if (udp_lib_checksum_complete(skb))
 685                        goto csum_error;
 686        }
 687
 688        if (sk_rcvqueues_full(sk, sk->sk_rcvbuf)) {
 689                UDP6_INC_STATS_BH(sock_net(sk),
 690                                  UDP_MIB_RCVBUFERRORS, is_udplite);
 691                goto drop;
 692        }
 693
 694        skb_dst_drop(skb);
 695
 696        bh_lock_sock(sk);
 697        rc = 0;
 698        if (!sock_owned_by_user(sk))
 699                rc = __udpv6_queue_rcv_skb(sk, skb);
 700        else if (sk_add_backlog(sk, skb, sk->sk_rcvbuf)) {
 701                bh_unlock_sock(sk);
 702                goto drop;
 703        }
 704        bh_unlock_sock(sk);
 705
 706        return rc;
 707
 708csum_error:
 709        UDP6_INC_STATS_BH(sock_net(sk), UDP_MIB_CSUMERRORS, is_udplite);
 710drop:
 711        UDP6_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
 712        atomic_inc(&sk->sk_drops);
 713        kfree_skb(skb);
 714        return -1;
 715}
 716
 717static bool __udp_v6_is_mcast_sock(struct net *net, struct sock *sk,
 718                                   __be16 loc_port, const struct in6_addr *loc_addr,
 719                                   __be16 rmt_port, const struct in6_addr *rmt_addr,
 720                                   int dif, unsigned short hnum)
 721{
 722        struct inet_sock *inet = inet_sk(sk);
 723
 724        if (!net_eq(sock_net(sk), net))
 725                return false;
 726
 727        if (udp_sk(sk)->udp_port_hash != hnum ||
 728            sk->sk_family != PF_INET6 ||
 729            (inet->inet_dport && inet->inet_dport != rmt_port) ||
 730            (!ipv6_addr_any(&sk->sk_v6_daddr) &&
 731                    !ipv6_addr_equal(&sk->sk_v6_daddr, rmt_addr)) ||
 732            (sk->sk_bound_dev_if && sk->sk_bound_dev_if != dif) ||
 733            (!ipv6_addr_any(&sk->sk_v6_rcv_saddr) &&
 734                    !ipv6_addr_equal(&sk->sk_v6_rcv_saddr, loc_addr)))
 735                return false;
 736        if (!inet6_mc_check(sk, loc_addr, rmt_addr))
 737                return false;
 738        return true;
 739}
 740
 741static void flush_stack(struct sock **stack, unsigned int count,
 742                        struct sk_buff *skb, unsigned int final)
 743{
 744        struct sk_buff *skb1 = NULL;
 745        struct sock *sk;
 746        unsigned int i;
 747
 748        for (i = 0; i < count; i++) {
 749                sk = stack[i];
 750                if (likely(!skb1))
 751                        skb1 = (i == final) ? skb : skb_clone(skb, GFP_ATOMIC);
 752                if (!skb1) {
 753                        atomic_inc(&sk->sk_drops);
 754                        UDP6_INC_STATS_BH(sock_net(sk), UDP_MIB_RCVBUFERRORS,
 755                                          IS_UDPLITE(sk));
 756                        UDP6_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS,
 757                                          IS_UDPLITE(sk));
 758                }
 759
 760                if (skb1 && udpv6_queue_rcv_skb(sk, skb1) <= 0)
 761                        skb1 = NULL;
 762                sock_put(sk);
 763        }
 764        if (unlikely(skb1))
 765                kfree_skb(skb1);
 766}
 767
 768static void udp6_csum_zero_error(struct sk_buff *skb)
 769{
 770        /* RFC 2460 section 8.1 says that we SHOULD log
 771         * this error. Well, it is reasonable.
 772         */
 773        net_dbg_ratelimited("IPv6: udp checksum is 0 for [%pI6c]:%u->[%pI6c]:%u\n",
 774                            &ipv6_hdr(skb)->saddr, ntohs(udp_hdr(skb)->source),
 775                            &ipv6_hdr(skb)->daddr, ntohs(udp_hdr(skb)->dest));
 776}
 777
 778/*
 779 * Note: called only from the BH handler context,
 780 * so we don't need to lock the hashes.
 781 */
 782static int __udp6_lib_mcast_deliver(struct net *net, struct sk_buff *skb,
 783                const struct in6_addr *saddr, const struct in6_addr *daddr,
 784                struct udp_table *udptable, int proto)
 785{
 786        struct sock *sk, *stack[256 / sizeof(struct sock *)];
 787        const struct udphdr *uh = udp_hdr(skb);
 788        struct hlist_nulls_node *node;
 789        unsigned short hnum = ntohs(uh->dest);
 790        struct udp_hslot *hslot = udp_hashslot(udptable, net, hnum);
 791        int dif = inet6_iif(skb);
 792        unsigned int count = 0, offset = offsetof(typeof(*sk), sk_nulls_node);
 793        unsigned int hash2 = 0, hash2_any = 0, use_hash2 = (hslot->count > 10);
 794        bool inner_flushed = false;
 795
 796        if (use_hash2) {
 797                hash2_any = udp6_portaddr_hash(net, &in6addr_any, hnum) &
 798                            udp_table.mask;
 799                hash2 = udp6_portaddr_hash(net, daddr, hnum) & udp_table.mask;
 800start_lookup:
 801                hslot = &udp_table.hash2[hash2];
 802                offset = offsetof(typeof(*sk), __sk_common.skc_portaddr_node);
 803        }
 804
 805        spin_lock(&hslot->lock);
 806        sk_nulls_for_each_entry_offset(sk, node, &hslot->head, offset) {
 807                if (__udp_v6_is_mcast_sock(net, sk,
 808                                           uh->dest, daddr,
 809                                           uh->source, saddr,
 810                                           dif, hnum) &&
 811                    /* If zero checksum and no_check is not on for
 812                     * the socket then skip it.
 813                     */
 814                    (uh->check || udp_sk(sk)->no_check6_rx)) {
 815                        if (unlikely(count == ARRAY_SIZE(stack))) {
 816                                flush_stack(stack, count, skb, ~0);
 817                                inner_flushed = true;
 818                                count = 0;
 819                        }
 820                        stack[count++] = sk;
 821                        sock_hold(sk);
 822                }
 823        }
 824
 825        spin_unlock(&hslot->lock);
 826
 827        /* Also lookup *:port if we are using hash2 and haven't done so yet. */
 828        if (use_hash2 && hash2 != hash2_any) {
 829                hash2 = hash2_any;
 830                goto start_lookup;
 831        }
 832
 833        if (count) {
 834                flush_stack(stack, count, skb, count - 1);
 835        } else {
 836                if (!inner_flushed)
 837                        UDP_INC_STATS_BH(net, UDP_MIB_IGNOREDMULTI,
 838                                         proto == IPPROTO_UDPLITE);
 839                consume_skb(skb);
 840        }
 841        return 0;
 842}
 843
 844int __udp6_lib_rcv(struct sk_buff *skb, struct udp_table *udptable,
 845                   int proto)
 846{
 847        struct net *net = dev_net(skb->dev);
 848        struct sock *sk;
 849        struct udphdr *uh;
 850        const struct in6_addr *saddr, *daddr;
 851        u32 ulen = 0;
 852
 853        if (!pskb_may_pull(skb, sizeof(struct udphdr)))
 854                goto discard;
 855
 856        saddr = &ipv6_hdr(skb)->saddr;
 857        daddr = &ipv6_hdr(skb)->daddr;
 858        uh = udp_hdr(skb);
 859
 860        ulen = ntohs(uh->len);
 861        if (ulen > skb->len)
 862                goto short_packet;
 863
 864        if (proto == IPPROTO_UDP) {
 865                /* UDP validates ulen. */
 866
 867                /* Check for jumbo payload */
 868                if (ulen == 0)
 869                        ulen = skb->len;
 870
 871                if (ulen < sizeof(*uh))
 872                        goto short_packet;
 873
 874                if (ulen < skb->len) {
 875                        if (pskb_trim_rcsum(skb, ulen))
 876                                goto short_packet;
 877                        saddr = &ipv6_hdr(skb)->saddr;
 878                        daddr = &ipv6_hdr(skb)->daddr;
 879                        uh = udp_hdr(skb);
 880                }
 881        }
 882
 883        if (udp6_csum_init(skb, uh, proto))
 884                goto csum_error;
 885
 886        /*
 887         *      Multicast receive code
 888         */
 889        if (ipv6_addr_is_multicast(daddr))
 890                return __udp6_lib_mcast_deliver(net, skb,
 891                                saddr, daddr, udptable, proto);
 892
 893        /* Unicast */
 894
 895        /*
 896         * check socket cache ... must talk to Alan about his plans
 897         * for sock caches... i'll skip this for now.
 898         */
 899        sk = __udp6_lib_lookup_skb(skb, uh->source, uh->dest, udptable);
 900        if (sk) {
 901                int ret;
 902
 903                if (!uh->check && !udp_sk(sk)->no_check6_rx) {
 904                        sock_put(sk);
 905                        udp6_csum_zero_error(skb);
 906                        goto csum_error;
 907                }
 908
 909                if (inet_get_convert_csum(sk) && uh->check && !IS_UDPLITE(sk))
 910                        skb_checksum_try_convert(skb, IPPROTO_UDP, uh->check,
 911                                                 ip6_compute_pseudo);
 912
 913                ret = udpv6_queue_rcv_skb(sk, skb);
 914                sock_put(sk);
 915
 916                /* a return value > 0 means to resubmit the input, but
 917                 * it wants the return to be -protocol, or 0
 918                 */
 919                if (ret > 0)
 920                        return -ret;
 921
 922                return 0;
 923        }
 924
 925        if (!uh->check) {
 926                udp6_csum_zero_error(skb);
 927                goto csum_error;
 928        }
 929
 930        if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
 931                goto discard;
 932
 933        if (udp_lib_checksum_complete(skb))
 934                goto csum_error;
 935
 936        UDP6_INC_STATS_BH(net, UDP_MIB_NOPORTS, proto == IPPROTO_UDPLITE);
 937        icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0);
 938
 939        kfree_skb(skb);
 940        return 0;
 941
 942short_packet:
 943        net_dbg_ratelimited("UDP%sv6: short packet: From [%pI6c]:%u %d/%d to [%pI6c]:%u\n",
 944                            proto == IPPROTO_UDPLITE ? "-Lite" : "",
 945                            saddr, ntohs(uh->source),
 946                            ulen, skb->len,
 947                            daddr, ntohs(uh->dest));
 948        goto discard;
 949csum_error:
 950        UDP6_INC_STATS_BH(net, UDP_MIB_CSUMERRORS, proto == IPPROTO_UDPLITE);
 951discard:
 952        UDP6_INC_STATS_BH(net, UDP_MIB_INERRORS, proto == IPPROTO_UDPLITE);
 953        kfree_skb(skb);
 954        return 0;
 955}
 956
 957static __inline__ int udpv6_rcv(struct sk_buff *skb)
 958{
 959        return __udp6_lib_rcv(skb, &udp_table, IPPROTO_UDP);
 960}
 961
 962/*
 963 * Throw away all pending data and cancel the corking. Socket is locked.
 964 */
 965static void udp_v6_flush_pending_frames(struct sock *sk)
 966{
 967        struct udp_sock *up = udp_sk(sk);
 968
 969        if (up->pending == AF_INET)
 970                udp_flush_pending_frames(sk);
 971        else if (up->pending) {
 972                up->len = 0;
 973                up->pending = 0;
 974                ip6_flush_pending_frames(sk);
 975        }
 976}
 977
 978/**
 979 *      udp6_hwcsum_outgoing  -  handle outgoing HW checksumming
 980 *      @sk:    socket we are sending on
 981 *      @skb:   sk_buff containing the filled-in UDP header
 982 *              (checksum field must be zeroed out)
 983 */
 984static void udp6_hwcsum_outgoing(struct sock *sk, struct sk_buff *skb,
 985                                 const struct in6_addr *saddr,
 986                                 const struct in6_addr *daddr, int len)
 987{
 988        unsigned int offset;
 989        struct udphdr *uh = udp_hdr(skb);
 990        struct sk_buff *frags = skb_shinfo(skb)->frag_list;
 991        __wsum csum = 0;
 992
 993        if (!frags) {
 994                /* Only one fragment on the socket.  */
 995                skb->csum_start = skb_transport_header(skb) - skb->head;
 996                skb->csum_offset = offsetof(struct udphdr, check);
 997                uh->check = ~csum_ipv6_magic(saddr, daddr, len, IPPROTO_UDP, 0);
 998        } else {
 999                /*
1000                 * HW-checksum won't work as there are two or more
1001                 * fragments on the socket so that all csums of sk_buffs
1002                 * should be together
1003                 */
1004                offset = skb_transport_offset(skb);
1005                skb->csum = skb_checksum(skb, offset, skb->len - offset, 0);
1006
1007                skb->ip_summed = CHECKSUM_NONE;
1008
1009                do {
1010                        csum = csum_add(csum, frags->csum);
1011                } while ((frags = frags->next));
1012
1013                uh->check = csum_ipv6_magic(saddr, daddr, len, IPPROTO_UDP,
1014                                            csum);
1015                if (uh->check == 0)
1016                        uh->check = CSUM_MANGLED_0;
1017        }
1018}
1019
1020/*
1021 *      Sending
1022 */
1023
1024static int udp_v6_send_skb(struct sk_buff *skb, struct flowi6 *fl6)
1025{
1026        struct sock *sk = skb->sk;
1027        struct udphdr *uh;
1028        int err = 0;
1029        int is_udplite = IS_UDPLITE(sk);
1030        __wsum csum = 0;
1031        int offset = skb_transport_offset(skb);
1032        int len = skb->len - offset;
1033
1034        /*
1035         * Create a UDP header
1036         */
1037        uh = udp_hdr(skb);
1038        uh->source = fl6->fl6_sport;
1039        uh->dest = fl6->fl6_dport;
1040        uh->len = htons(len);
1041        uh->check = 0;
1042
1043        if (is_udplite)
1044                csum = udplite_csum(skb);
1045        else if (udp_sk(sk)->no_check6_tx) {   /* UDP csum disabled */
1046                skb->ip_summed = CHECKSUM_NONE;
1047                goto send;
1048        } else if (skb->ip_summed == CHECKSUM_PARTIAL) { /* UDP hardware csum */
1049                udp6_hwcsum_outgoing(sk, skb, &fl6->saddr, &fl6->daddr, len);
1050                goto send;
1051        } else
1052                csum = udp_csum(skb);
1053
1054        /* add protocol-dependent pseudo-header */
1055        uh->check = csum_ipv6_magic(&fl6->saddr, &fl6->daddr,
1056                                    len, fl6->flowi6_proto, csum);
1057        if (uh->check == 0)
1058                uh->check = CSUM_MANGLED_0;
1059
1060send:
1061        err = ip6_send_skb(skb);
1062        if (err) {
1063                if (err == -ENOBUFS && !inet6_sk(sk)->recverr) {
1064                        UDP6_INC_STATS_USER(sock_net(sk),
1065                                            UDP_MIB_SNDBUFERRORS, is_udplite);
1066                        err = 0;
1067                }
1068        } else
1069                UDP6_INC_STATS_USER(sock_net(sk),
1070                                    UDP_MIB_OUTDATAGRAMS, is_udplite);
1071        return err;
1072}
1073
1074static int udp_v6_push_pending_frames(struct sock *sk)
1075{
1076        struct sk_buff *skb;
1077        struct udp_sock  *up = udp_sk(sk);
1078        struct flowi6 fl6;
1079        int err = 0;
1080
1081        if (up->pending == AF_INET)
1082                return udp_push_pending_frames(sk);
1083
1084        /* ip6_finish_skb will release the cork, so make a copy of
1085         * fl6 here.
1086         */
1087        fl6 = inet_sk(sk)->cork.fl.u.ip6;
1088
1089        skb = ip6_finish_skb(sk);
1090        if (!skb)
1091                goto out;
1092
1093        err = udp_v6_send_skb(skb, &fl6);
1094
1095out:
1096        up->len = 0;
1097        up->pending = 0;
1098        return err;
1099}
1100
1101int udpv6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
1102{
1103        struct ipv6_txoptions opt_space;
1104        struct udp_sock *up = udp_sk(sk);
1105        struct inet_sock *inet = inet_sk(sk);
1106        struct ipv6_pinfo *np = inet6_sk(sk);
1107        DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name);
1108        struct in6_addr *daddr, *final_p, final;
1109        struct ipv6_txoptions *opt = NULL;
1110        struct ip6_flowlabel *flowlabel = NULL;
1111        struct flowi6 fl6;
1112        struct dst_entry *dst;
1113        int addr_len = msg->msg_namelen;
1114        int ulen = len;
1115        int hlimit = -1;
1116        int tclass = -1;
1117        int dontfrag = -1;
1118        int corkreq = up->corkflag || msg->msg_flags&MSG_MORE;
1119        int err;
1120        int connected = 0;
1121        int is_udplite = IS_UDPLITE(sk);
1122        int (*getfrag)(void *, char *, int, int, int, struct sk_buff *);
1123
1124        /* destination address check */
1125        if (sin6) {
1126                if (addr_len < offsetof(struct sockaddr, sa_data))
1127                        return -EINVAL;
1128
1129                switch (sin6->sin6_family) {
1130                case AF_INET6:
1131                        if (addr_len < SIN6_LEN_RFC2133)
1132                                return -EINVAL;
1133                        daddr = &sin6->sin6_addr;
1134                        break;
1135                case AF_INET:
1136                        goto do_udp_sendmsg;
1137                case AF_UNSPEC:
1138                        msg->msg_name = sin6 = NULL;
1139                        msg->msg_namelen = addr_len = 0;
1140                        daddr = NULL;
1141                        break;
1142                default:
1143                        return -EINVAL;
1144                }
1145        } else if (!up->pending) {
1146                if (sk->sk_state != TCP_ESTABLISHED)
1147                        return -EDESTADDRREQ;
1148                daddr = &sk->sk_v6_daddr;
1149        } else
1150                daddr = NULL;
1151
1152        if (daddr) {
1153                if (ipv6_addr_v4mapped(daddr)) {
1154                        struct sockaddr_in sin;
1155                        sin.sin_family = AF_INET;
1156                        sin.sin_port = sin6 ? sin6->sin6_port : inet->inet_dport;
1157                        sin.sin_addr.s_addr = daddr->s6_addr32[3];
1158                        msg->msg_name = &sin;
1159                        msg->msg_namelen = sizeof(sin);
1160do_udp_sendmsg:
1161                        if (__ipv6_only_sock(sk))
1162                                return -ENETUNREACH;
1163                        return udp_sendmsg(sk, msg, len);
1164                }
1165        }
1166
1167        if (up->pending == AF_INET)
1168                return udp_sendmsg(sk, msg, len);
1169
1170        /* Rough check on arithmetic overflow,
1171           better check is made in ip6_append_data().
1172           */
1173        if (len > INT_MAX - sizeof(struct udphdr))
1174                return -EMSGSIZE;
1175
1176        getfrag  =  is_udplite ?  udplite_getfrag : ip_generic_getfrag;
1177        if (up->pending) {
1178                /*
1179                 * There are pending frames.
1180                 * The socket lock must be held while it's corked.
1181                 */
1182                lock_sock(sk);
1183                if (likely(up->pending)) {
1184                        if (unlikely(up->pending != AF_INET6)) {
1185                                release_sock(sk);
1186                                return -EAFNOSUPPORT;
1187                        }
1188                        dst = NULL;
1189                        goto do_append_data;
1190                }
1191                release_sock(sk);
1192        }
1193        ulen += sizeof(struct udphdr);
1194
1195        memset(&fl6, 0, sizeof(fl6));
1196
1197        if (sin6) {
1198                if (sin6->sin6_port == 0)
1199                        return -EINVAL;
1200
1201                fl6.fl6_dport = sin6->sin6_port;
1202                daddr = &sin6->sin6_addr;
1203
1204                if (np->sndflow) {
1205                        fl6.flowlabel = sin6->sin6_flowinfo&IPV6_FLOWINFO_MASK;
1206                        if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) {
1207                                flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
1208                                if (!flowlabel)
1209                                        return -EINVAL;
1210                        }
1211                }
1212
1213                /*
1214                 * Otherwise it will be difficult to maintain
1215                 * sk->sk_dst_cache.
1216                 */
1217                if (sk->sk_state == TCP_ESTABLISHED &&
1218                    ipv6_addr_equal(daddr, &sk->sk_v6_daddr))
1219                        daddr = &sk->sk_v6_daddr;
1220
1221                if (addr_len >= sizeof(struct sockaddr_in6) &&
1222                    sin6->sin6_scope_id &&
1223                    __ipv6_addr_needs_scope_id(__ipv6_addr_type(daddr)))
1224                        fl6.flowi6_oif = sin6->sin6_scope_id;
1225        } else {
1226                if (sk->sk_state != TCP_ESTABLISHED)
1227                        return -EDESTADDRREQ;
1228
1229                fl6.fl6_dport = inet->inet_dport;
1230                daddr = &sk->sk_v6_daddr;
1231                fl6.flowlabel = np->flow_label;
1232                connected = 1;
1233        }
1234
1235        if (!fl6.flowi6_oif)
1236                fl6.flowi6_oif = sk->sk_bound_dev_if;
1237
1238        if (!fl6.flowi6_oif)
1239                fl6.flowi6_oif = np->sticky_pktinfo.ipi6_ifindex;
1240
1241        fl6.flowi6_mark = sk->sk_mark;
1242
1243        if (msg->msg_controllen) {
1244                opt = &opt_space;
1245                memset(opt, 0, sizeof(struct ipv6_txoptions));
1246                opt->tot_len = sizeof(*opt);
1247
1248                err = ip6_datagram_send_ctl(sock_net(sk), sk, msg, &fl6, opt,
1249                                            &hlimit, &tclass, &dontfrag);
1250                if (err < 0) {
1251                        fl6_sock_release(flowlabel);
1252                        return err;
1253                }
1254                if ((fl6.flowlabel&IPV6_FLOWLABEL_MASK) && !flowlabel) {
1255                        flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
1256                        if (!flowlabel)
1257                                return -EINVAL;
1258                }
1259                if (!(opt->opt_nflen|opt->opt_flen))
1260                        opt = NULL;
1261                connected = 0;
1262        }
1263        if (!opt)
1264                opt = np->opt;
1265        if (flowlabel)
1266                opt = fl6_merge_options(&opt_space, flowlabel, opt);
1267        opt = ipv6_fixup_options(&opt_space, opt);
1268
1269        fl6.flowi6_proto = sk->sk_protocol;
1270        if (!ipv6_addr_any(daddr))
1271                fl6.daddr = *daddr;
1272        else
1273                fl6.daddr.s6_addr[15] = 0x1; /* :: means loopback (BSD'ism) */
1274        if (ipv6_addr_any(&fl6.saddr) && !ipv6_addr_any(&np->saddr))
1275                fl6.saddr = np->saddr;
1276        fl6.fl6_sport = inet->inet_sport;
1277
1278        final_p = fl6_update_dst(&fl6, opt, &final);
1279        if (final_p)
1280                connected = 0;
1281
1282        if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr)) {
1283                fl6.flowi6_oif = np->mcast_oif;
1284                connected = 0;
1285        } else if (!fl6.flowi6_oif)
1286                fl6.flowi6_oif = np->ucast_oif;
1287
1288        security_sk_classify_flow(sk, flowi6_to_flowi(&fl6));
1289
1290        dst = ip6_sk_dst_lookup_flow(sk, &fl6, final_p);
1291        if (IS_ERR(dst)) {
1292                err = PTR_ERR(dst);
1293                dst = NULL;
1294                goto out;
1295        }
1296
1297        if (hlimit < 0)
1298                hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst);
1299
1300        if (tclass < 0)
1301                tclass = np->tclass;
1302
1303        if (msg->msg_flags&MSG_CONFIRM)
1304                goto do_confirm;
1305back_from_confirm:
1306
1307        /* Lockless fast path for the non-corking case */
1308        if (!corkreq) {
1309                struct sk_buff *skb;
1310
1311                skb = ip6_make_skb(sk, getfrag, msg, ulen,
1312                                   sizeof(struct udphdr), hlimit, tclass, opt,
1313                                   &fl6, (struct rt6_info *)dst,
1314                                   msg->msg_flags, dontfrag);
1315                err = PTR_ERR(skb);
1316                if (!IS_ERR_OR_NULL(skb))
1317                        err = udp_v6_send_skb(skb, &fl6);
1318                goto release_dst;
1319        }
1320
1321        lock_sock(sk);
1322        if (unlikely(up->pending)) {
1323                /* The socket is already corked while preparing it. */
1324                /* ... which is an evident application bug. --ANK */
1325                release_sock(sk);
1326
1327                net_dbg_ratelimited("udp cork app bug 2\n");
1328                err = -EINVAL;
1329                goto out;
1330        }
1331
1332        up->pending = AF_INET6;
1333
1334do_append_data:
1335        if (dontfrag < 0)
1336                dontfrag = np->dontfrag;
1337        up->len += ulen;
1338        err = ip6_append_data(sk, getfrag, msg, ulen,
1339                sizeof(struct udphdr), hlimit, tclass, opt, &fl6,
1340                (struct rt6_info *)dst,
1341                corkreq ? msg->msg_flags|MSG_MORE : msg->msg_flags, dontfrag);
1342        if (err)
1343                udp_v6_flush_pending_frames(sk);
1344        else if (!corkreq)
1345                err = udp_v6_push_pending_frames(sk);
1346        else if (unlikely(skb_queue_empty(&sk->sk_write_queue)))
1347                up->pending = 0;
1348
1349        if (err > 0)
1350                err = np->recverr ? net_xmit_errno(err) : 0;
1351        release_sock(sk);
1352
1353release_dst:
1354        if (dst) {
1355                if (connected) {
1356                        ip6_dst_store(sk, dst,
1357                                      ipv6_addr_equal(&fl6.daddr, &sk->sk_v6_daddr) ?
1358                                      &sk->sk_v6_daddr : NULL,
1359#ifdef CONFIG_IPV6_SUBTREES
1360                                      ipv6_addr_equal(&fl6.saddr, &np->saddr) ?
1361                                      &np->saddr :
1362#endif
1363                                      NULL);
1364                } else {
1365                        dst_release(dst);
1366                }
1367                dst = NULL;
1368        }
1369
1370out:
1371        dst_release(dst);
1372        fl6_sock_release(flowlabel);
1373        if (!err)
1374                return len;
1375        /*
1376         * ENOBUFS = no kernel mem, SOCK_NOSPACE = no sndbuf space.  Reporting
1377         * ENOBUFS might not be good (it's not tunable per se), but otherwise
1378         * we don't have a good statistic (IpOutDiscards but it can be too many
1379         * things).  We could add another new stat but at least for now that
1380         * seems like overkill.
1381         */
1382        if (err == -ENOBUFS || test_bit(SOCK_NOSPACE, &sk->sk_socket->flags)) {
1383                UDP6_INC_STATS_USER(sock_net(sk),
1384                                UDP_MIB_SNDBUFERRORS, is_udplite);
1385        }
1386        return err;
1387
1388do_confirm:
1389        dst_confirm(dst);
1390        if (!(msg->msg_flags&MSG_PROBE) || len)
1391                goto back_from_confirm;
1392        err = 0;
1393        goto out;
1394}
1395
1396void udpv6_destroy_sock(struct sock *sk)
1397{
1398        struct udp_sock *up = udp_sk(sk);
1399        lock_sock(sk);
1400        udp_v6_flush_pending_frames(sk);
1401        release_sock(sk);
1402
1403        if (static_key_false(&udpv6_encap_needed) && up->encap_type) {
1404                void (*encap_destroy)(struct sock *sk);
1405                encap_destroy = ACCESS_ONCE(up->encap_destroy);
1406                if (encap_destroy)
1407                        encap_destroy(sk);
1408        }
1409
1410        inet6_destroy_sock(sk);
1411}
1412
1413/*
1414 *      Socket option code for UDP
1415 */
1416int udpv6_setsockopt(struct sock *sk, int level, int optname,
1417                     char __user *optval, unsigned int optlen)
1418{
1419        if (level == SOL_UDP  ||  level == SOL_UDPLITE)
1420                return udp_lib_setsockopt(sk, level, optname, optval, optlen,
1421                                          udp_v6_push_pending_frames);
1422        return ipv6_setsockopt(sk, level, optname, optval, optlen);
1423}
1424
1425#ifdef CONFIG_COMPAT
1426int compat_udpv6_setsockopt(struct sock *sk, int level, int optname,
1427                            char __user *optval, unsigned int optlen)
1428{
1429        if (level == SOL_UDP  ||  level == SOL_UDPLITE)
1430                return udp_lib_setsockopt(sk, level, optname, optval, optlen,
1431                                          udp_v6_push_pending_frames);
1432        return compat_ipv6_setsockopt(sk, level, optname, optval, optlen);
1433}
1434#endif
1435
1436int udpv6_getsockopt(struct sock *sk, int level, int optname,
1437                     char __user *optval, int __user *optlen)
1438{
1439        if (level == SOL_UDP  ||  level == SOL_UDPLITE)
1440                return udp_lib_getsockopt(sk, level, optname, optval, optlen);
1441        return ipv6_getsockopt(sk, level, optname, optval, optlen);
1442}
1443
1444#ifdef CONFIG_COMPAT
1445int compat_udpv6_getsockopt(struct sock *sk, int level, int optname,
1446                            char __user *optval, int __user *optlen)
1447{
1448        if (level == SOL_UDP  ||  level == SOL_UDPLITE)
1449                return udp_lib_getsockopt(sk, level, optname, optval, optlen);
1450        return compat_ipv6_getsockopt(sk, level, optname, optval, optlen);
1451}
1452#endif
1453
1454static const struct inet6_protocol udpv6_protocol = {
1455        .handler        =       udpv6_rcv,
1456        .err_handler    =       udpv6_err,
1457        .flags          =       INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
1458};
1459
1460/* ------------------------------------------------------------------------ */
1461#ifdef CONFIG_PROC_FS
1462int udp6_seq_show(struct seq_file *seq, void *v)
1463{
1464        if (v == SEQ_START_TOKEN) {
1465                seq_puts(seq, IPV6_SEQ_DGRAM_HEADER);
1466        } else {
1467                int bucket = ((struct udp_iter_state *)seq->private)->bucket;
1468                struct inet_sock *inet = inet_sk(v);
1469                __u16 srcp = ntohs(inet->inet_sport);
1470                __u16 destp = ntohs(inet->inet_dport);
1471                ip6_dgram_sock_seq_show(seq, v, srcp, destp, bucket);
1472        }
1473        return 0;
1474}
1475
1476static const struct file_operations udp6_afinfo_seq_fops = {
1477        .owner    = THIS_MODULE,
1478        .open     = udp_seq_open,
1479        .read     = seq_read,
1480        .llseek   = seq_lseek,
1481        .release  = seq_release_net
1482};
1483
1484static struct udp_seq_afinfo udp6_seq_afinfo = {
1485        .name           = "udp6",
1486        .family         = AF_INET6,
1487        .udp_table      = &udp_table,
1488        .seq_fops       = &udp6_afinfo_seq_fops,
1489        .seq_ops        = {
1490                .show           = udp6_seq_show,
1491        },
1492};
1493
1494int __net_init udp6_proc_init(struct net *net)
1495{
1496        return udp_proc_register(net, &udp6_seq_afinfo);
1497}
1498
1499void udp6_proc_exit(struct net *net) {
1500        udp_proc_unregister(net, &udp6_seq_afinfo);
1501}
1502#endif /* CONFIG_PROC_FS */
1503
1504void udp_v6_clear_sk(struct sock *sk, int size)
1505{
1506        struct inet_sock *inet = inet_sk(sk);
1507
1508        /* we do not want to clear pinet6 field, because of RCU lookups */
1509        sk_prot_clear_portaddr_nulls(sk, offsetof(struct inet_sock, pinet6));
1510
1511        size -= offsetof(struct inet_sock, pinet6) + sizeof(inet->pinet6);
1512        memset(&inet->pinet6 + 1, 0, size);
1513}
1514
1515/* ------------------------------------------------------------------------ */
1516
1517struct proto udpv6_prot = {
1518        .name              = "UDPv6",
1519        .owner             = THIS_MODULE,
1520        .close             = udp_lib_close,
1521        .connect           = ip6_datagram_connect,
1522        .disconnect        = udp_disconnect,
1523        .ioctl             = udp_ioctl,
1524        .destroy           = udpv6_destroy_sock,
1525        .setsockopt        = udpv6_setsockopt,
1526        .getsockopt        = udpv6_getsockopt,
1527        .sendmsg           = udpv6_sendmsg,
1528        .recvmsg           = udpv6_recvmsg,
1529        .backlog_rcv       = __udpv6_queue_rcv_skb,
1530        .hash              = udp_lib_hash,
1531        .unhash            = udp_lib_unhash,
1532        .rehash            = udp_v6_rehash,
1533        .get_port          = udp_v6_get_port,
1534        .memory_allocated  = &udp_memory_allocated,
1535        .sysctl_mem        = sysctl_udp_mem,
1536        .sysctl_wmem       = &sysctl_udp_wmem_min,
1537        .sysctl_rmem       = &sysctl_udp_rmem_min,
1538        .obj_size          = sizeof(struct udp6_sock),
1539        .slab_flags        = SLAB_DESTROY_BY_RCU,
1540        .h.udp_table       = &udp_table,
1541#ifdef CONFIG_COMPAT
1542        .compat_setsockopt = compat_udpv6_setsockopt,
1543        .compat_getsockopt = compat_udpv6_getsockopt,
1544#endif
1545        .clear_sk          = udp_v6_clear_sk,
1546};
1547
1548static struct inet_protosw udpv6_protosw = {
1549        .type =      SOCK_DGRAM,
1550        .protocol =  IPPROTO_UDP,
1551        .prot =      &udpv6_prot,
1552        .ops =       &inet6_dgram_ops,
1553        .flags =     INET_PROTOSW_PERMANENT,
1554};
1555
1556int __init udpv6_init(void)
1557{
1558        int ret;
1559
1560        ret = inet6_add_protocol(&udpv6_protocol, IPPROTO_UDP);
1561        if (ret)
1562                goto out;
1563
1564        ret = inet6_register_protosw(&udpv6_protosw);
1565        if (ret)
1566                goto out_udpv6_protocol;
1567out:
1568        return ret;
1569
1570out_udpv6_protocol:
1571        inet6_del_protocol(&udpv6_protocol, IPPROTO_UDP);
1572        goto out;
1573}
1574
1575void udpv6_exit(void)
1576{
1577        inet6_unregister_protosw(&udpv6_protosw);
1578        inet6_del_protocol(&udpv6_protocol, IPPROTO_UDP);
1579}
1580