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
  50#include <linux/proc_fs.h>
  51#include <linux/seq_file.h>
  52#include <trace/events/skb.h>
  53#include "udp_impl.h"
  54
  55int ipv6_rcv_saddr_equal(const struct sock *sk, const struct sock *sk2)
  56{
  57        const struct in6_addr *sk_rcv_saddr6 = &inet6_sk(sk)->rcv_saddr;
  58        const struct in6_addr *sk2_rcv_saddr6 = inet6_rcv_saddr(sk2);
  59        __be32 sk1_rcv_saddr = sk_rcv_saddr(sk);
  60        __be32 sk2_rcv_saddr = sk_rcv_saddr(sk2);
  61        int sk_ipv6only = ipv6_only_sock(sk);
  62        int sk2_ipv6only = inet_v6_ipv6only(sk2);
  63        int addr_type = ipv6_addr_type(sk_rcv_saddr6);
  64        int addr_type2 = sk2_rcv_saddr6 ? ipv6_addr_type(sk2_rcv_saddr6) : IPV6_ADDR_MAPPED;
  65
  66        /* if both are mapped, treat as IPv4 */
  67        if (addr_type == IPV6_ADDR_MAPPED && addr_type2 == IPV6_ADDR_MAPPED)
  68                return (!sk2_ipv6only &&
  69                        (!sk1_rcv_saddr || !sk2_rcv_saddr ||
  70                          sk1_rcv_saddr == sk2_rcv_saddr));
  71
  72        if (addr_type2 == IPV6_ADDR_ANY &&
  73            !(sk2_ipv6only && addr_type == IPV6_ADDR_MAPPED))
  74                return 1;
  75
  76        if (addr_type == IPV6_ADDR_ANY &&
  77            !(sk_ipv6only && addr_type2 == IPV6_ADDR_MAPPED))
  78                return 1;
  79
  80        if (sk2_rcv_saddr6 &&
  81            ipv6_addr_equal(sk_rcv_saddr6, sk2_rcv_saddr6))
  82                return 1;
  83
  84        return 0;
  85}
  86
  87static unsigned int udp6_portaddr_hash(struct net *net,
  88                                       const struct in6_addr *addr6,
  89                                       unsigned int port)
  90{
  91        unsigned int hash, mix = net_hash_mix(net);
  92
  93        if (ipv6_addr_any(addr6))
  94                hash = jhash_1word(0, mix);
  95        else if (ipv6_addr_v4mapped(addr6))
  96                hash = jhash_1word((__force u32)addr6->s6_addr32[3], mix);
  97        else
  98                hash = jhash2((__force u32 *)addr6->s6_addr32, 4, mix);
  99
 100        return hash ^ port;
 101}
 102
 103
 104int udp_v6_get_port(struct sock *sk, unsigned short snum)
 105{
 106        unsigned int hash2_nulladdr =
 107                udp6_portaddr_hash(sock_net(sk), &in6addr_any, snum);
 108        unsigned int hash2_partial =
 109                udp6_portaddr_hash(sock_net(sk), &inet6_sk(sk)->rcv_saddr, 0);
 110
 111        /* precompute partial secondary hash */
 112        udp_sk(sk)->udp_portaddr_hash = hash2_partial;
 113        return udp_lib_get_port(sk, snum, ipv6_rcv_saddr_equal, hash2_nulladdr);
 114}
 115
 116static void udp_v6_rehash(struct sock *sk)
 117{
 118        u16 new_hash = udp6_portaddr_hash(sock_net(sk),
 119                                          &inet6_sk(sk)->rcv_saddr,
 120                                          inet_sk(sk)->inet_num);
 121
 122        udp_lib_rehash(sk, new_hash);
 123}
 124
 125static inline int compute_score(struct sock *sk, struct net *net,
 126                                unsigned short hnum,
 127                                const struct in6_addr *saddr, __be16 sport,
 128                                const struct in6_addr *daddr, __be16 dport,
 129                                int dif)
 130{
 131        int score = -1;
 132
 133        if (net_eq(sock_net(sk), net) && udp_sk(sk)->udp_port_hash == hnum &&
 134                        sk->sk_family == PF_INET6) {
 135                struct ipv6_pinfo *np = inet6_sk(sk);
 136                struct inet_sock *inet = inet_sk(sk);
 137
 138                score = 0;
 139                if (inet->inet_dport) {
 140                        if (inet->inet_dport != sport)
 141                                return -1;
 142                        score++;
 143                }
 144                if (!ipv6_addr_any(&np->rcv_saddr)) {
 145                        if (!ipv6_addr_equal(&np->rcv_saddr, daddr))
 146                                return -1;
 147                        score++;
 148                }
 149                if (!ipv6_addr_any(&np->daddr)) {
 150                        if (!ipv6_addr_equal(&np->daddr, saddr))
 151                                return -1;
 152                        score++;
 153                }
 154                if (sk->sk_bound_dev_if) {
 155                        if (sk->sk_bound_dev_if != dif)
 156                                return -1;
 157                        score++;
 158                }
 159        }
 160        return score;
 161}
 162
 163#define SCORE2_MAX (1 + 1 + 1)
 164static inline int compute_score2(struct sock *sk, struct net *net,
 165                                const struct in6_addr *saddr, __be16 sport,
 166                                const struct in6_addr *daddr, unsigned short hnum,
 167                                int dif)
 168{
 169        int score = -1;
 170
 171        if (net_eq(sock_net(sk), net) && udp_sk(sk)->udp_port_hash == hnum &&
 172                        sk->sk_family == PF_INET6) {
 173                struct ipv6_pinfo *np = inet6_sk(sk);
 174                struct inet_sock *inet = inet_sk(sk);
 175
 176                if (!ipv6_addr_equal(&np->rcv_saddr, daddr))
 177                        return -1;
 178                score = 0;
 179                if (inet->inet_dport) {
 180                        if (inet->inet_dport != sport)
 181                                return -1;
 182                        score++;
 183                }
 184                if (!ipv6_addr_any(&np->daddr)) {
 185                        if (!ipv6_addr_equal(&np->daddr, saddr))
 186                                return -1;
 187                        score++;
 188                }
 189                if (sk->sk_bound_dev_if) {
 190                        if (sk->sk_bound_dev_if != dif)
 191                                return -1;
 192                        score++;
 193                }
 194        }
 195        return score;
 196}
 197
 198
 199/* called with read_rcu_lock() */
 200static struct sock *udp6_lib_lookup2(struct net *net,
 201                const struct in6_addr *saddr, __be16 sport,
 202                const struct in6_addr *daddr, unsigned int hnum, int dif,
 203                struct udp_hslot *hslot2, unsigned int slot2)
 204{
 205        struct sock *sk, *result;
 206        struct hlist_nulls_node *node;
 207        int score, badness, matches = 0, reuseport = 0;
 208        u32 hash = 0;
 209
 210begin:
 211        result = NULL;
 212        badness = -1;
 213        udp_portaddr_for_each_entry_rcu(sk, node, &hslot2->head) {
 214                score = compute_score2(sk, net, saddr, sport,
 215                                      daddr, hnum, dif);
 216                if (score > badness) {
 217                        result = sk;
 218                        badness = score;
 219                        reuseport = sk->sk_reuseport;
 220                        if (reuseport) {
 221                                hash = inet6_ehashfn(net, daddr, hnum,
 222                                                     saddr, sport);
 223                                matches = 1;
 224                        } else if (score == SCORE2_MAX)
 225                                goto exact_match;
 226                } else if (score == badness && reuseport) {
 227                        matches++;
 228                        if (((u64)hash * matches) >> 32 == 0)
 229                                result = sk;
 230                        hash = next_pseudo_random32(hash);
 231                }
 232        }
 233        /*
 234         * if the nulls value we got at the end of this lookup is
 235         * not the expected one, we must restart lookup.
 236         * We probably met an item that was moved to another chain.
 237         */
 238        if (get_nulls_value(node) != slot2)
 239                goto begin;
 240
 241        if (result) {
 242exact_match:
 243                if (unlikely(!atomic_inc_not_zero_hint(&result->sk_refcnt, 2)))
 244                        result = NULL;
 245                else if (unlikely(compute_score2(result, net, saddr, sport,
 246                                  daddr, hnum, dif) < badness)) {
 247                        sock_put(result);
 248                        goto begin;
 249                }
 250        }
 251        return result;
 252}
 253
 254struct sock *__udp6_lib_lookup(struct net *net,
 255                                      const struct in6_addr *saddr, __be16 sport,
 256                                      const struct in6_addr *daddr, __be16 dport,
 257                                      int dif, struct udp_table *udptable)
 258{
 259        struct sock *sk, *result;
 260        struct hlist_nulls_node *node;
 261        unsigned short hnum = ntohs(dport);
 262        unsigned int hash2, slot2, slot = udp_hashfn(net, hnum, udptable->mask);
 263        struct udp_hslot *hslot2, *hslot = &udptable->hash[slot];
 264        int score, badness, matches = 0, reuseport = 0;
 265        u32 hash = 0;
 266
 267        rcu_read_lock();
 268        if (hslot->count > 10) {
 269                hash2 = udp6_portaddr_hash(net, daddr, hnum);
 270                slot2 = hash2 & udptable->mask;
 271                hslot2 = &udptable->hash2[slot2];
 272                if (hslot->count < hslot2->count)
 273                        goto begin;
 274
 275                result = udp6_lib_lookup2(net, saddr, sport,
 276                                          daddr, hnum, dif,
 277                                          hslot2, slot2);
 278                if (!result) {
 279                        hash2 = udp6_portaddr_hash(net, &in6addr_any, hnum);
 280                        slot2 = hash2 & udptable->mask;
 281                        hslot2 = &udptable->hash2[slot2];
 282                        if (hslot->count < hslot2->count)
 283                                goto begin;
 284
 285                        result = udp6_lib_lookup2(net, saddr, sport,
 286                                                  &in6addr_any, hnum, dif,
 287                                                  hslot2, slot2);
 288                }
 289                rcu_read_unlock();
 290                return result;
 291        }
 292begin:
 293        result = NULL;
 294        badness = -1;
 295        sk_nulls_for_each_rcu(sk, node, &hslot->head) {
 296                score = compute_score(sk, net, hnum, saddr, sport, daddr, dport, dif);
 297                if (score > badness) {
 298                        result = sk;
 299                        badness = score;
 300                        reuseport = sk->sk_reuseport;
 301                        if (reuseport) {
 302                                hash = inet6_ehashfn(net, daddr, hnum,
 303                                                     saddr, sport);
 304                                matches = 1;
 305                        }
 306                } else if (score == badness && reuseport) {
 307                        matches++;
 308                        if (((u64)hash * matches) >> 32 == 0)
 309                                result = sk;
 310                        hash = next_pseudo_random32(hash);
 311                }
 312        }
 313        /*
 314         * if the nulls value we got at the end of this lookup is
 315         * not the expected one, we must restart lookup.
 316         * We probably met an item that was moved to another chain.
 317         */
 318        if (get_nulls_value(node) != slot)
 319                goto begin;
 320
 321        if (result) {
 322                if (unlikely(!atomic_inc_not_zero_hint(&result->sk_refcnt, 2)))
 323                        result = NULL;
 324                else if (unlikely(compute_score(result, net, hnum, saddr, sport,
 325                                        daddr, dport, dif) < badness)) {
 326                        sock_put(result);
 327                        goto begin;
 328                }
 329        }
 330        rcu_read_unlock();
 331        return result;
 332}
 333EXPORT_SYMBOL_GPL(__udp6_lib_lookup);
 334
 335static struct sock *__udp6_lib_lookup_skb(struct sk_buff *skb,
 336                                          __be16 sport, __be16 dport,
 337                                          struct udp_table *udptable)
 338{
 339        struct sock *sk;
 340        const struct ipv6hdr *iph = ipv6_hdr(skb);
 341
 342        if (unlikely(sk = skb_steal_sock(skb)))
 343                return sk;
 344        return __udp6_lib_lookup(dev_net(skb_dst(skb)->dev), &iph->saddr, sport,
 345                                 &iph->daddr, dport, inet6_iif(skb),
 346                                 udptable);
 347}
 348
 349struct sock *udp6_lib_lookup(struct net *net, const struct in6_addr *saddr, __be16 sport,
 350                             const struct in6_addr *daddr, __be16 dport, int dif)
 351{
 352        return __udp6_lib_lookup(net, saddr, sport, daddr, dport, dif, &udp_table);
 353}
 354EXPORT_SYMBOL_GPL(udp6_lib_lookup);
 355
 356
 357/*
 358 *      This should be easy, if there is something there we
 359 *      return it, otherwise we block.
 360 */
 361
 362int udpv6_recvmsg(struct kiocb *iocb, struct sock *sk,
 363                  struct msghdr *msg, size_t len,
 364                  int noblock, int flags, int *addr_len)
 365{
 366        struct ipv6_pinfo *np = inet6_sk(sk);
 367        struct inet_sock *inet = inet_sk(sk);
 368        struct sk_buff *skb;
 369        unsigned int ulen, copied;
 370        int peeked, off = 0;
 371        int err;
 372        int is_udplite = IS_UDPLITE(sk);
 373        int is_udp4;
 374        bool slow;
 375
 376        if (addr_len)
 377                *addr_len = sizeof(struct sockaddr_in6);
 378
 379        if (flags & MSG_ERRQUEUE)
 380                return ipv6_recv_error(sk, msg, len);
 381
 382        if (np->rxpmtu && np->rxopt.bits.rxpmtu)
 383                return ipv6_recv_rxpmtu(sk, msg, len);
 384
 385try_again:
 386        skb = __skb_recv_datagram(sk, flags | (noblock ? MSG_DONTWAIT : 0),
 387                                  &peeked, &off, &err);
 388        if (!skb)
 389                goto out;
 390
 391        ulen = skb->len - sizeof(struct udphdr);
 392        copied = len;
 393        if (copied > ulen)
 394                copied = ulen;
 395        else if (copied < ulen)
 396                msg->msg_flags |= MSG_TRUNC;
 397
 398        is_udp4 = (skb->protocol == htons(ETH_P_IP));
 399
 400        /*
 401         * If checksum is needed at all, try to do it while copying the
 402         * data.  If the data is truncated, or if we only want a partial
 403         * coverage checksum (UDP-Lite), do it before the copy.
 404         */
 405
 406        if (copied < ulen || UDP_SKB_CB(skb)->partial_cov) {
 407                if (udp_lib_checksum_complete(skb))
 408                        goto csum_copy_err;
 409        }
 410
 411        if (skb_csum_unnecessary(skb))
 412                err = skb_copy_datagram_iovec(skb, sizeof(struct udphdr),
 413                                              msg->msg_iov, copied);
 414        else {
 415                err = skb_copy_and_csum_datagram_iovec(skb, sizeof(struct udphdr), msg->msg_iov);
 416                if (err == -EINVAL)
 417                        goto csum_copy_err;
 418        }
 419        if (unlikely(err)) {
 420                trace_kfree_skb(skb, udpv6_recvmsg);
 421                if (!peeked) {
 422                        atomic_inc(&sk->sk_drops);
 423                        if (is_udp4)
 424                                UDP_INC_STATS_USER(sock_net(sk),
 425                                                   UDP_MIB_INERRORS,
 426                                                   is_udplite);
 427                        else
 428                                UDP6_INC_STATS_USER(sock_net(sk),
 429                                                    UDP_MIB_INERRORS,
 430                                                    is_udplite);
 431                }
 432                goto out_free;
 433        }
 434        if (!peeked) {
 435                if (is_udp4)
 436                        UDP_INC_STATS_USER(sock_net(sk),
 437                                        UDP_MIB_INDATAGRAMS, is_udplite);
 438                else
 439                        UDP6_INC_STATS_USER(sock_net(sk),
 440                                        UDP_MIB_INDATAGRAMS, is_udplite);
 441        }
 442
 443        sock_recv_ts_and_drops(msg, sk, skb);
 444
 445        /* Copy the address. */
 446        if (msg->msg_name) {
 447                struct sockaddr_in6 *sin6;
 448
 449                sin6 = (struct sockaddr_in6 *) msg->msg_name;
 450                sin6->sin6_family = AF_INET6;
 451                sin6->sin6_port = udp_hdr(skb)->source;
 452                sin6->sin6_flowinfo = 0;
 453
 454                if (is_udp4) {
 455                        ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr,
 456                                               &sin6->sin6_addr);
 457                        sin6->sin6_scope_id = 0;
 458                } else {
 459                        sin6->sin6_addr = ipv6_hdr(skb)->saddr;
 460                        sin6->sin6_scope_id =
 461                                ipv6_iface_scope_id(&sin6->sin6_addr,
 462                                                    IP6CB(skb)->iif);
 463                }
 464
 465        }
 466        if (is_udp4) {
 467                if (inet->cmsg_flags)
 468                        ip_cmsg_recv(msg, skb);
 469        } else {
 470                if (np->rxopt.all)
 471                        ip6_datagram_recv_ctl(sk, msg, skb);
 472        }
 473
 474        err = copied;
 475        if (flags & MSG_TRUNC)
 476                err = ulen;
 477
 478out_free:
 479        skb_free_datagram_locked(sk, skb);
 480out:
 481        return err;
 482
 483csum_copy_err:
 484        slow = lock_sock_fast(sk);
 485        if (!skb_kill_datagram(sk, skb, flags)) {
 486                if (is_udp4) {
 487                        UDP_INC_STATS_USER(sock_net(sk),
 488                                        UDP_MIB_CSUMERRORS, is_udplite);
 489                        UDP_INC_STATS_USER(sock_net(sk),
 490                                        UDP_MIB_INERRORS, is_udplite);
 491                } else {
 492                        UDP6_INC_STATS_USER(sock_net(sk),
 493                                        UDP_MIB_CSUMERRORS, is_udplite);
 494                        UDP6_INC_STATS_USER(sock_net(sk),
 495                                        UDP_MIB_INERRORS, is_udplite);
 496                }
 497        }
 498        unlock_sock_fast(sk, slow);
 499
 500        if (noblock)
 501                return -EAGAIN;
 502
 503        /* starting over for a new packet */
 504        msg->msg_flags &= ~MSG_TRUNC;
 505        goto try_again;
 506}
 507
 508void __udp6_lib_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 509                    u8 type, u8 code, int offset, __be32 info,
 510                    struct udp_table *udptable)
 511{
 512        struct ipv6_pinfo *np;
 513        const struct ipv6hdr *hdr = (const struct ipv6hdr *)skb->data;
 514        const struct in6_addr *saddr = &hdr->saddr;
 515        const struct in6_addr *daddr = &hdr->daddr;
 516        struct udphdr *uh = (struct udphdr*)(skb->data+offset);
 517        struct sock *sk;
 518        int err;
 519
 520        sk = __udp6_lib_lookup(dev_net(skb->dev), daddr, uh->dest,
 521                               saddr, uh->source, inet6_iif(skb), udptable);
 522        if (sk == NULL)
 523                return;
 524
 525        if (type == ICMPV6_PKT_TOOBIG)
 526                ip6_sk_update_pmtu(skb, sk, info);
 527        if (type == NDISC_REDIRECT)
 528                ip6_sk_redirect(skb, sk);
 529
 530        np = inet6_sk(sk);
 531
 532        if (!icmpv6_err_convert(type, code, &err) && !np->recverr)
 533                goto out;
 534
 535        if (sk->sk_state != TCP_ESTABLISHED && !np->recverr)
 536                goto out;
 537
 538        if (np->recverr)
 539                ipv6_icmp_error(sk, skb, err, uh->dest, ntohl(info), (u8 *)(uh+1));
 540
 541        sk->sk_err = err;
 542        sk->sk_error_report(sk);
 543out:
 544        sock_put(sk);
 545}
 546
 547static int __udpv6_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
 548{
 549        int rc;
 550
 551        if (!ipv6_addr_any(&inet6_sk(sk)->daddr))
 552                sock_rps_save_rxhash(sk, skb);
 553
 554        rc = sock_queue_rcv_skb(sk, skb);
 555        if (rc < 0) {
 556                int is_udplite = IS_UDPLITE(sk);
 557
 558                /* Note that an ENOMEM error is charged twice */
 559                if (rc == -ENOMEM)
 560                        UDP6_INC_STATS_BH(sock_net(sk),
 561                                        UDP_MIB_RCVBUFERRORS, is_udplite);
 562                UDP6_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
 563                kfree_skb(skb);
 564                return -1;
 565        }
 566        return 0;
 567}
 568
 569static __inline__ void udpv6_err(struct sk_buff *skb,
 570                                 struct inet6_skb_parm *opt, u8 type,
 571                                 u8 code, int offset, __be32 info     )
 572{
 573        __udp6_lib_err(skb, opt, type, code, offset, info, &udp_table);
 574}
 575
 576static struct static_key udpv6_encap_needed __read_mostly;
 577void udpv6_encap_enable(void)
 578{
 579        if (!static_key_enabled(&udpv6_encap_needed))
 580                static_key_slow_inc(&udpv6_encap_needed);
 581}
 582EXPORT_SYMBOL(udpv6_encap_enable);
 583
 584int udpv6_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
 585{
 586        struct udp_sock *up = udp_sk(sk);
 587        int rc;
 588        int is_udplite = IS_UDPLITE(sk);
 589
 590        if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
 591                goto drop;
 592
 593        if (static_key_false(&udpv6_encap_needed) && up->encap_type) {
 594                int (*encap_rcv)(struct sock *sk, struct sk_buff *skb);
 595
 596                /*
 597                 * This is an encapsulation socket so pass the skb to
 598                 * the socket's udp_encap_rcv() hook. Otherwise, just
 599                 * fall through and pass this up the UDP socket.
 600                 * up->encap_rcv() returns the following value:
 601                 * =0 if skb was successfully passed to the encap
 602                 *    handler or was discarded by it.
 603                 * >0 if skb should be passed on to UDP.
 604                 * <0 if skb should be resubmitted as proto -N
 605                 */
 606
 607                /* if we're overly short, let UDP handle it */
 608                encap_rcv = ACCESS_ONCE(up->encap_rcv);
 609                if (skb->len > sizeof(struct udphdr) && encap_rcv != NULL) {
 610                        int ret;
 611
 612                        ret = encap_rcv(sk, skb);
 613                        if (ret <= 0) {
 614                                UDP_INC_STATS_BH(sock_net(sk),
 615                                                 UDP_MIB_INDATAGRAMS,
 616                                                 is_udplite);
 617                                return -ret;
 618                        }
 619                }
 620
 621                /* FALLTHROUGH -- it's a UDP Packet */
 622        }
 623
 624        /*
 625         * UDP-Lite specific tests, ignored on UDP sockets (see net/ipv4/udp.c).
 626         */
 627        if ((is_udplite & UDPLITE_RECV_CC)  &&  UDP_SKB_CB(skb)->partial_cov) {
 628
 629                if (up->pcrlen == 0) {          /* full coverage was set  */
 630                        LIMIT_NETDEBUG(KERN_WARNING "UDPLITE6: partial coverage"
 631                                " %d while full coverage %d requested\n",
 632                                UDP_SKB_CB(skb)->cscov, skb->len);
 633                        goto drop;
 634                }
 635                if (UDP_SKB_CB(skb)->cscov  <  up->pcrlen) {
 636                        LIMIT_NETDEBUG(KERN_WARNING "UDPLITE6: coverage %d "
 637                                                    "too small, need min %d\n",
 638                                       UDP_SKB_CB(skb)->cscov, up->pcrlen);
 639                        goto drop;
 640                }
 641        }
 642
 643        if (rcu_access_pointer(sk->sk_filter)) {
 644                if (udp_lib_checksum_complete(skb))
 645                        goto csum_error;
 646        }
 647
 648        if (sk_rcvqueues_full(sk, skb, sk->sk_rcvbuf))
 649                goto drop;
 650
 651        skb_dst_drop(skb);
 652
 653        bh_lock_sock(sk);
 654        rc = 0;
 655        if (!sock_owned_by_user(sk))
 656                rc = __udpv6_queue_rcv_skb(sk, skb);
 657        else if (sk_add_backlog(sk, skb, sk->sk_rcvbuf)) {
 658                bh_unlock_sock(sk);
 659                goto drop;
 660        }
 661        bh_unlock_sock(sk);
 662
 663        return rc;
 664csum_error:
 665        UDP6_INC_STATS_BH(sock_net(sk), UDP_MIB_CSUMERRORS, is_udplite);
 666drop:
 667        UDP6_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
 668        atomic_inc(&sk->sk_drops);
 669        kfree_skb(skb);
 670        return -1;
 671}
 672
 673static struct sock *udp_v6_mcast_next(struct net *net, struct sock *sk,
 674                                      __be16 loc_port, const struct in6_addr *loc_addr,
 675                                      __be16 rmt_port, const struct in6_addr *rmt_addr,
 676                                      int dif)
 677{
 678        struct hlist_nulls_node *node;
 679        struct sock *s = sk;
 680        unsigned short num = ntohs(loc_port);
 681
 682        sk_nulls_for_each_from(s, node) {
 683                struct inet_sock *inet = inet_sk(s);
 684
 685                if (!net_eq(sock_net(s), net))
 686                        continue;
 687
 688                if (udp_sk(s)->udp_port_hash == num &&
 689                    s->sk_family == PF_INET6) {
 690                        struct ipv6_pinfo *np = inet6_sk(s);
 691                        if (inet->inet_dport) {
 692                                if (inet->inet_dport != rmt_port)
 693                                        continue;
 694                        }
 695                        if (!ipv6_addr_any(&np->daddr) &&
 696                            !ipv6_addr_equal(&np->daddr, rmt_addr))
 697                                continue;
 698
 699                        if (s->sk_bound_dev_if && s->sk_bound_dev_if != dif)
 700                                continue;
 701
 702                        if (!ipv6_addr_any(&np->rcv_saddr)) {
 703                                if (!ipv6_addr_equal(&np->rcv_saddr, loc_addr))
 704                                        continue;
 705                        }
 706                        if (!inet6_mc_check(s, loc_addr, rmt_addr))
 707                                continue;
 708                        return s;
 709                }
 710        }
 711        return NULL;
 712}
 713
 714static void flush_stack(struct sock **stack, unsigned int count,
 715                        struct sk_buff *skb, unsigned int final)
 716{
 717        struct sk_buff *skb1 = NULL;
 718        struct sock *sk;
 719        unsigned int i;
 720
 721        for (i = 0; i < count; i++) {
 722                sk = stack[i];
 723                if (likely(skb1 == NULL))
 724                        skb1 = (i == final) ? skb : skb_clone(skb, GFP_ATOMIC);
 725                if (!skb1) {
 726                        atomic_inc(&sk->sk_drops);
 727                        UDP6_INC_STATS_BH(sock_net(sk), UDP_MIB_RCVBUFERRORS,
 728                                          IS_UDPLITE(sk));
 729                        UDP6_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS,
 730                                          IS_UDPLITE(sk));
 731                }
 732
 733                if (skb1 && udpv6_queue_rcv_skb(sk, skb1) <= 0)
 734                        skb1 = NULL;
 735        }
 736        if (unlikely(skb1))
 737                kfree_skb(skb1);
 738}
 739/*
 740 * Note: called only from the BH handler context,
 741 * so we don't need to lock the hashes.
 742 */
 743static int __udp6_lib_mcast_deliver(struct net *net, struct sk_buff *skb,
 744                const struct in6_addr *saddr, const struct in6_addr *daddr,
 745                struct udp_table *udptable)
 746{
 747        struct sock *sk, *stack[256 / sizeof(struct sock *)];
 748        const struct udphdr *uh = udp_hdr(skb);
 749        struct udp_hslot *hslot = udp_hashslot(udptable, net, ntohs(uh->dest));
 750        int dif;
 751        unsigned int i, count = 0;
 752
 753        spin_lock(&hslot->lock);
 754        sk = sk_nulls_head(&hslot->head);
 755        dif = inet6_iif(skb);
 756        sk = udp_v6_mcast_next(net, sk, uh->dest, daddr, uh->source, saddr, dif);
 757        while (sk) {
 758                stack[count++] = sk;
 759                sk = udp_v6_mcast_next(net, sk_nulls_next(sk), uh->dest, daddr,
 760                                       uh->source, saddr, dif);
 761                if (unlikely(count == ARRAY_SIZE(stack))) {
 762                        if (!sk)
 763                                break;
 764                        flush_stack(stack, count, skb, ~0);
 765                        count = 0;
 766                }
 767        }
 768        /*
 769         * before releasing the lock, we must take reference on sockets
 770         */
 771        for (i = 0; i < count; i++)
 772                sock_hold(stack[i]);
 773
 774        spin_unlock(&hslot->lock);
 775
 776        if (count) {
 777                flush_stack(stack, count, skb, count - 1);
 778
 779                for (i = 0; i < count; i++)
 780                        sock_put(stack[i]);
 781        } else {
 782                kfree_skb(skb);
 783        }
 784        return 0;
 785}
 786
 787int __udp6_lib_rcv(struct sk_buff *skb, struct udp_table *udptable,
 788                   int proto)
 789{
 790        struct net *net = dev_net(skb->dev);
 791        struct sock *sk;
 792        struct udphdr *uh;
 793        const struct in6_addr *saddr, *daddr;
 794        u32 ulen = 0;
 795
 796        if (!pskb_may_pull(skb, sizeof(struct udphdr)))
 797                goto discard;
 798
 799        saddr = &ipv6_hdr(skb)->saddr;
 800        daddr = &ipv6_hdr(skb)->daddr;
 801        uh = udp_hdr(skb);
 802
 803        ulen = ntohs(uh->len);
 804        if (ulen > skb->len)
 805                goto short_packet;
 806
 807        if (proto == IPPROTO_UDP) {
 808                /* UDP validates ulen. */
 809
 810                /* Check for jumbo payload */
 811                if (ulen == 0)
 812                        ulen = skb->len;
 813
 814                if (ulen < sizeof(*uh))
 815                        goto short_packet;
 816
 817                if (ulen < skb->len) {
 818                        if (pskb_trim_rcsum(skb, ulen))
 819                                goto short_packet;
 820                        saddr = &ipv6_hdr(skb)->saddr;
 821                        daddr = &ipv6_hdr(skb)->daddr;
 822                        uh = udp_hdr(skb);
 823                }
 824        }
 825
 826        if (udp6_csum_init(skb, uh, proto))
 827                goto csum_error;
 828
 829        /*
 830         *      Multicast receive code
 831         */
 832        if (ipv6_addr_is_multicast(daddr))
 833                return __udp6_lib_mcast_deliver(net, skb,
 834                                saddr, daddr, udptable);
 835
 836        /* Unicast */
 837
 838        /*
 839         * check socket cache ... must talk to Alan about his plans
 840         * for sock caches... i'll skip this for now.
 841         */
 842        sk = __udp6_lib_lookup_skb(skb, uh->source, uh->dest, udptable);
 843        if (sk != NULL) {
 844                int ret = udpv6_queue_rcv_skb(sk, skb);
 845                sock_put(sk);
 846
 847                /* a return value > 0 means to resubmit the input, but
 848                 * it wants the return to be -protocol, or 0
 849                 */
 850                if (ret > 0)
 851                        return -ret;
 852
 853                return 0;
 854        }
 855
 856        if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
 857                goto discard;
 858
 859        if (udp_lib_checksum_complete(skb))
 860                goto csum_error;
 861
 862        UDP6_INC_STATS_BH(net, UDP_MIB_NOPORTS, proto == IPPROTO_UDPLITE);
 863        icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0);
 864
 865        kfree_skb(skb);
 866        return 0;
 867
 868short_packet:
 869        LIMIT_NETDEBUG(KERN_DEBUG "UDP%sv6: short packet: From [%pI6c]:%u %d/%d to [%pI6c]:%u\n",
 870                       proto == IPPROTO_UDPLITE ? "-Lite" : "",
 871                       saddr,
 872                       ntohs(uh->source),
 873                       ulen,
 874                       skb->len,
 875                       daddr,
 876                       ntohs(uh->dest));
 877        goto discard;
 878csum_error:
 879        UDP6_INC_STATS_BH(net, UDP_MIB_CSUMERRORS, proto == IPPROTO_UDPLITE);
 880discard:
 881        UDP6_INC_STATS_BH(net, UDP_MIB_INERRORS, proto == IPPROTO_UDPLITE);
 882        kfree_skb(skb);
 883        return 0;
 884}
 885
 886static __inline__ int udpv6_rcv(struct sk_buff *skb)
 887{
 888        return __udp6_lib_rcv(skb, &udp_table, IPPROTO_UDP);
 889}
 890
 891/*
 892 * Throw away all pending data and cancel the corking. Socket is locked.
 893 */
 894static void udp_v6_flush_pending_frames(struct sock *sk)
 895{
 896        struct udp_sock *up = udp_sk(sk);
 897
 898        if (up->pending == AF_INET)
 899                udp_flush_pending_frames(sk);
 900        else if (up->pending) {
 901                up->len = 0;
 902                up->pending = 0;
 903                ip6_flush_pending_frames(sk);
 904        }
 905}
 906
 907/**
 908 *      udp6_hwcsum_outgoing  -  handle outgoing HW checksumming
 909 *      @sk:    socket we are sending on
 910 *      @skb:   sk_buff containing the filled-in UDP header
 911 *              (checksum field must be zeroed out)
 912 */
 913static void udp6_hwcsum_outgoing(struct sock *sk, struct sk_buff *skb,
 914                                 const struct in6_addr *saddr,
 915                                 const struct in6_addr *daddr, int len)
 916{
 917        unsigned int offset;
 918        struct udphdr *uh = udp_hdr(skb);
 919        __wsum csum = 0;
 920
 921        if (skb_queue_len(&sk->sk_write_queue) == 1) {
 922                /* Only one fragment on the socket.  */
 923                skb->csum_start = skb_transport_header(skb) - skb->head;
 924                skb->csum_offset = offsetof(struct udphdr, check);
 925                uh->check = ~csum_ipv6_magic(saddr, daddr, len, IPPROTO_UDP, 0);
 926        } else {
 927                /*
 928                 * HW-checksum won't work as there are two or more
 929                 * fragments on the socket so that all csums of sk_buffs
 930                 * should be together
 931                 */
 932                offset = skb_transport_offset(skb);
 933                skb->csum = skb_checksum(skb, offset, skb->len - offset, 0);
 934
 935                skb->ip_summed = CHECKSUM_NONE;
 936
 937                skb_queue_walk(&sk->sk_write_queue, skb) {
 938                        csum = csum_add(csum, skb->csum);
 939                }
 940
 941                uh->check = csum_ipv6_magic(saddr, daddr, len, IPPROTO_UDP,
 942                                            csum);
 943                if (uh->check == 0)
 944                        uh->check = CSUM_MANGLED_0;
 945        }
 946}
 947
 948/*
 949 *      Sending
 950 */
 951
 952static int udp_v6_push_pending_frames(struct sock *sk)
 953{
 954        struct sk_buff *skb;
 955        struct udphdr *uh;
 956        struct udp_sock  *up = udp_sk(sk);
 957        struct inet_sock *inet = inet_sk(sk);
 958        struct flowi6 *fl6 = &inet->cork.fl.u.ip6;
 959        int err = 0;
 960        int is_udplite = IS_UDPLITE(sk);
 961        __wsum csum = 0;
 962
 963        /* Grab the skbuff where UDP header space exists. */
 964        if ((skb = skb_peek(&sk->sk_write_queue)) == NULL)
 965                goto out;
 966
 967        /*
 968         * Create a UDP header
 969         */
 970        uh = udp_hdr(skb);
 971        uh->source = fl6->fl6_sport;
 972        uh->dest = fl6->fl6_dport;
 973        uh->len = htons(up->len);
 974        uh->check = 0;
 975
 976        if (is_udplite)
 977                csum = udplite_csum_outgoing(sk, skb);
 978        else if (skb->ip_summed == CHECKSUM_PARTIAL) { /* UDP hardware csum */
 979                udp6_hwcsum_outgoing(sk, skb, &fl6->saddr, &fl6->daddr,
 980                                     up->len);
 981                goto send;
 982        } else
 983                csum = udp_csum_outgoing(sk, skb);
 984
 985        /* add protocol-dependent pseudo-header */
 986        uh->check = csum_ipv6_magic(&fl6->saddr, &fl6->daddr,
 987                                    up->len, fl6->flowi6_proto, csum);
 988        if (uh->check == 0)
 989                uh->check = CSUM_MANGLED_0;
 990
 991send:
 992        err = ip6_push_pending_frames(sk);
 993        if (err) {
 994                if (err == -ENOBUFS && !inet6_sk(sk)->recverr) {
 995                        UDP6_INC_STATS_USER(sock_net(sk),
 996                                            UDP_MIB_SNDBUFERRORS, is_udplite);
 997                        err = 0;
 998                }
 999        } else
1000                UDP6_INC_STATS_USER(sock_net(sk),
1001                                    UDP_MIB_OUTDATAGRAMS, is_udplite);
1002out:
1003        up->len = 0;
1004        up->pending = 0;
1005        return err;
1006}
1007
1008int udpv6_sendmsg(struct kiocb *iocb, struct sock *sk,
1009                  struct msghdr *msg, size_t len)
1010{
1011        struct ipv6_txoptions opt_space;
1012        struct udp_sock *up = udp_sk(sk);
1013        struct inet_sock *inet = inet_sk(sk);
1014        struct ipv6_pinfo *np = inet6_sk(sk);
1015        struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *) msg->msg_name;
1016        struct in6_addr *daddr, *final_p, final;
1017        struct ipv6_txoptions *opt = NULL;
1018        struct ip6_flowlabel *flowlabel = NULL;
1019        struct flowi6 fl6;
1020        struct dst_entry *dst;
1021        int addr_len = msg->msg_namelen;
1022        int ulen = len;
1023        int hlimit = -1;
1024        int tclass = -1;
1025        int dontfrag = -1;
1026        int corkreq = up->corkflag || msg->msg_flags&MSG_MORE;
1027        int err;
1028        int connected = 0;
1029        int is_udplite = IS_UDPLITE(sk);
1030        int (*getfrag)(void *, char *, int, int, int, struct sk_buff *);
1031
1032        /* destination address check */
1033        if (sin6) {
1034                if (addr_len < offsetof(struct sockaddr, sa_data))
1035                        return -EINVAL;
1036
1037                switch (sin6->sin6_family) {
1038                case AF_INET6:
1039                        if (addr_len < SIN6_LEN_RFC2133)
1040                                return -EINVAL;
1041                        daddr = &sin6->sin6_addr;
1042                        break;
1043                case AF_INET:
1044                        goto do_udp_sendmsg;
1045                case AF_UNSPEC:
1046                        msg->msg_name = sin6 = NULL;
1047                        msg->msg_namelen = addr_len = 0;
1048                        daddr = NULL;
1049                        break;
1050                default:
1051                        return -EINVAL;
1052                }
1053        } else if (!up->pending) {
1054                if (sk->sk_state != TCP_ESTABLISHED)
1055                        return -EDESTADDRREQ;
1056                daddr = &np->daddr;
1057        } else
1058                daddr = NULL;
1059
1060        if (daddr) {
1061                if (ipv6_addr_v4mapped(daddr)) {
1062                        struct sockaddr_in sin;
1063                        sin.sin_family = AF_INET;
1064                        sin.sin_port = sin6 ? sin6->sin6_port : inet->inet_dport;
1065                        sin.sin_addr.s_addr = daddr->s6_addr32[3];
1066                        msg->msg_name = &sin;
1067                        msg->msg_namelen = sizeof(sin);
1068do_udp_sendmsg:
1069                        if (__ipv6_only_sock(sk))
1070                                return -ENETUNREACH;
1071                        return udp_sendmsg(iocb, sk, msg, len);
1072                }
1073        }
1074
1075        if (up->pending == AF_INET)
1076                return udp_sendmsg(iocb, sk, msg, len);
1077
1078        /* Rough check on arithmetic overflow,
1079           better check is made in ip6_append_data().
1080           */
1081        if (len > INT_MAX - sizeof(struct udphdr))
1082                return -EMSGSIZE;
1083
1084        if (up->pending) {
1085                /*
1086                 * There are pending frames.
1087                 * The socket lock must be held while it's corked.
1088                 */
1089                lock_sock(sk);
1090                if (likely(up->pending)) {
1091                        if (unlikely(up->pending != AF_INET6)) {
1092                                release_sock(sk);
1093                                return -EAFNOSUPPORT;
1094                        }
1095                        dst = NULL;
1096                        goto do_append_data;
1097                }
1098                release_sock(sk);
1099        }
1100        ulen += sizeof(struct udphdr);
1101
1102        memset(&fl6, 0, sizeof(fl6));
1103
1104        if (sin6) {
1105                if (sin6->sin6_port == 0)
1106                        return -EINVAL;
1107
1108                fl6.fl6_dport = sin6->sin6_port;
1109                daddr = &sin6->sin6_addr;
1110
1111                if (np->sndflow) {
1112                        fl6.flowlabel = sin6->sin6_flowinfo&IPV6_FLOWINFO_MASK;
1113                        if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) {
1114                                flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
1115                                if (flowlabel == NULL)
1116                                        return -EINVAL;
1117                                daddr = &flowlabel->dst;
1118                        }
1119                }
1120
1121                /*
1122                 * Otherwise it will be difficult to maintain
1123                 * sk->sk_dst_cache.
1124                 */
1125                if (sk->sk_state == TCP_ESTABLISHED &&
1126                    ipv6_addr_equal(daddr, &np->daddr))
1127                        daddr = &np->daddr;
1128
1129                if (addr_len >= sizeof(struct sockaddr_in6) &&
1130                    sin6->sin6_scope_id &&
1131                    __ipv6_addr_needs_scope_id(__ipv6_addr_type(daddr)))
1132                        fl6.flowi6_oif = sin6->sin6_scope_id;
1133        } else {
1134                if (sk->sk_state != TCP_ESTABLISHED)
1135                        return -EDESTADDRREQ;
1136
1137                fl6.fl6_dport = inet->inet_dport;
1138                daddr = &np->daddr;
1139                fl6.flowlabel = np->flow_label;
1140                connected = 1;
1141        }
1142
1143        if (!fl6.flowi6_oif)
1144                fl6.flowi6_oif = sk->sk_bound_dev_if;
1145
1146        if (!fl6.flowi6_oif)
1147                fl6.flowi6_oif = np->sticky_pktinfo.ipi6_ifindex;
1148
1149        fl6.flowi6_mark = sk->sk_mark;
1150
1151        if (msg->msg_controllen) {
1152                opt = &opt_space;
1153                memset(opt, 0, sizeof(struct ipv6_txoptions));
1154                opt->tot_len = sizeof(*opt);
1155
1156                err = ip6_datagram_send_ctl(sock_net(sk), sk, msg, &fl6, opt,
1157                                            &hlimit, &tclass, &dontfrag);
1158                if (err < 0) {
1159                        fl6_sock_release(flowlabel);
1160                        return err;
1161                }
1162                if ((fl6.flowlabel&IPV6_FLOWLABEL_MASK) && !flowlabel) {
1163                        flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
1164                        if (flowlabel == NULL)
1165                                return -EINVAL;
1166                }
1167                if (!(opt->opt_nflen|opt->opt_flen))
1168                        opt = NULL;
1169                connected = 0;
1170        }
1171        if (opt == NULL)
1172                opt = np->opt;
1173        if (flowlabel)
1174                opt = fl6_merge_options(&opt_space, flowlabel, opt);
1175        opt = ipv6_fixup_options(&opt_space, opt);
1176
1177        fl6.flowi6_proto = sk->sk_protocol;
1178        if (!ipv6_addr_any(daddr))
1179                fl6.daddr = *daddr;
1180        else
1181                fl6.daddr.s6_addr[15] = 0x1; /* :: means loopback (BSD'ism) */
1182        if (ipv6_addr_any(&fl6.saddr) && !ipv6_addr_any(&np->saddr))
1183                fl6.saddr = np->saddr;
1184        fl6.fl6_sport = inet->inet_sport;
1185
1186        final_p = fl6_update_dst(&fl6, opt, &final);
1187        if (final_p)
1188                connected = 0;
1189
1190        if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr)) {
1191                fl6.flowi6_oif = np->mcast_oif;
1192                connected = 0;
1193        } else if (!fl6.flowi6_oif)
1194                fl6.flowi6_oif = np->ucast_oif;
1195
1196        security_sk_classify_flow(sk, flowi6_to_flowi(&fl6));
1197
1198        dst = ip6_sk_dst_lookup_flow(sk, &fl6, final_p, true);
1199        if (IS_ERR(dst)) {
1200                err = PTR_ERR(dst);
1201                dst = NULL;
1202                goto out;
1203        }
1204
1205        if (hlimit < 0) {
1206                if (ipv6_addr_is_multicast(&fl6.daddr))
1207                        hlimit = np->mcast_hops;
1208                else
1209                        hlimit = np->hop_limit;
1210                if (hlimit < 0)
1211                        hlimit = ip6_dst_hoplimit(dst);
1212        }
1213
1214        if (tclass < 0)
1215                tclass = np->tclass;
1216
1217        if (dontfrag < 0)
1218                dontfrag = np->dontfrag;
1219
1220        if (msg->msg_flags&MSG_CONFIRM)
1221                goto do_confirm;
1222back_from_confirm:
1223
1224        lock_sock(sk);
1225        if (unlikely(up->pending)) {
1226                /* The socket is already corked while preparing it. */
1227                /* ... which is an evident application bug. --ANK */
1228                release_sock(sk);
1229
1230                LIMIT_NETDEBUG(KERN_DEBUG "udp cork app bug 2\n");
1231                err = -EINVAL;
1232                goto out;
1233        }
1234
1235        up->pending = AF_INET6;
1236
1237do_append_data:
1238        up->len += ulen;
1239        getfrag  =  is_udplite ?  udplite_getfrag : ip_generic_getfrag;
1240        err = ip6_append_data(sk, getfrag, msg->msg_iov, ulen,
1241                sizeof(struct udphdr), hlimit, tclass, opt, &fl6,
1242                (struct rt6_info*)dst,
1243                corkreq ? msg->msg_flags|MSG_MORE : msg->msg_flags, dontfrag);
1244        if (err)
1245                udp_v6_flush_pending_frames(sk);
1246        else if (!corkreq)
1247                err = udp_v6_push_pending_frames(sk);
1248        else if (unlikely(skb_queue_empty(&sk->sk_write_queue)))
1249                up->pending = 0;
1250
1251        if (dst) {
1252                if (connected) {
1253                        ip6_dst_store(sk, dst,
1254                                      ipv6_addr_equal(&fl6.daddr, &np->daddr) ?
1255                                      &np->daddr : NULL,
1256#ifdef CONFIG_IPV6_SUBTREES
1257                                      ipv6_addr_equal(&fl6.saddr, &np->saddr) ?
1258                                      &np->saddr :
1259#endif
1260                                      NULL);
1261                } else {
1262                        dst_release(dst);
1263                }
1264                dst = NULL;
1265        }
1266
1267        if (err > 0)
1268                err = np->recverr ? net_xmit_errno(err) : 0;
1269        release_sock(sk);
1270out:
1271        dst_release(dst);
1272        fl6_sock_release(flowlabel);
1273        if (!err)
1274                return len;
1275        /*
1276         * ENOBUFS = no kernel mem, SOCK_NOSPACE = no sndbuf space.  Reporting
1277         * ENOBUFS might not be good (it's not tunable per se), but otherwise
1278         * we don't have a good statistic (IpOutDiscards but it can be too many
1279         * things).  We could add another new stat but at least for now that
1280         * seems like overkill.
1281         */
1282        if (err == -ENOBUFS || test_bit(SOCK_NOSPACE, &sk->sk_socket->flags)) {
1283                UDP6_INC_STATS_USER(sock_net(sk),
1284                                UDP_MIB_SNDBUFERRORS, is_udplite);
1285        }
1286        return err;
1287
1288do_confirm:
1289        dst_confirm(dst);
1290        if (!(msg->msg_flags&MSG_PROBE) || len)
1291                goto back_from_confirm;
1292        err = 0;
1293        goto out;
1294}
1295
1296void udpv6_destroy_sock(struct sock *sk)
1297{
1298        struct udp_sock *up = udp_sk(sk);
1299        lock_sock(sk);
1300        udp_v6_flush_pending_frames(sk);
1301        release_sock(sk);
1302
1303        if (static_key_false(&udpv6_encap_needed) && up->encap_type) {
1304                void (*encap_destroy)(struct sock *sk);
1305                encap_destroy = ACCESS_ONCE(up->encap_destroy);
1306                if (encap_destroy)
1307                        encap_destroy(sk);
1308        }
1309
1310        inet6_destroy_sock(sk);
1311}
1312
1313/*
1314 *      Socket option code for UDP
1315 */
1316int udpv6_setsockopt(struct sock *sk, int level, int optname,
1317                     char __user *optval, unsigned int optlen)
1318{
1319        if (level == SOL_UDP  ||  level == SOL_UDPLITE)
1320                return udp_lib_setsockopt(sk, level, optname, optval, optlen,
1321                                          udp_v6_push_pending_frames);
1322        return ipv6_setsockopt(sk, level, optname, optval, optlen);
1323}
1324
1325#ifdef CONFIG_COMPAT
1326int compat_udpv6_setsockopt(struct sock *sk, int level, int optname,
1327                            char __user *optval, unsigned int optlen)
1328{
1329        if (level == SOL_UDP  ||  level == SOL_UDPLITE)
1330                return udp_lib_setsockopt(sk, level, optname, optval, optlen,
1331                                          udp_v6_push_pending_frames);
1332        return compat_ipv6_setsockopt(sk, level, optname, optval, optlen);
1333}
1334#endif
1335
1336int udpv6_getsockopt(struct sock *sk, int level, int optname,
1337                     char __user *optval, int __user *optlen)
1338{
1339        if (level == SOL_UDP  ||  level == SOL_UDPLITE)
1340                return udp_lib_getsockopt(sk, level, optname, optval, optlen);
1341        return ipv6_getsockopt(sk, level, optname, optval, optlen);
1342}
1343
1344#ifdef CONFIG_COMPAT
1345int compat_udpv6_getsockopt(struct sock *sk, int level, int optname,
1346                            char __user *optval, int __user *optlen)
1347{
1348        if (level == SOL_UDP  ||  level == SOL_UDPLITE)
1349                return udp_lib_getsockopt(sk, level, optname, optval, optlen);
1350        return compat_ipv6_getsockopt(sk, level, optname, optval, optlen);
1351}
1352#endif
1353
1354static const struct inet6_protocol udpv6_protocol = {
1355        .handler        =       udpv6_rcv,
1356        .err_handler    =       udpv6_err,
1357        .flags          =       INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
1358};
1359
1360/* ------------------------------------------------------------------------ */
1361#ifdef CONFIG_PROC_FS
1362
1363static void udp6_sock_seq_show(struct seq_file *seq, struct sock *sp, int bucket)
1364{
1365        struct inet_sock *inet = inet_sk(sp);
1366        struct ipv6_pinfo *np = inet6_sk(sp);
1367        const struct in6_addr *dest, *src;
1368        __u16 destp, srcp;
1369
1370        dest  = &np->daddr;
1371        src   = &np->rcv_saddr;
1372        destp = ntohs(inet->inet_dport);
1373        srcp  = ntohs(inet->inet_sport);
1374        seq_printf(seq,
1375                   "%5d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1376                   "%02X %08X:%08X %02X:%08lX %08X %5d %8d %lu %d %pK %d\n",
1377                   bucket,
1378                   src->s6_addr32[0], src->s6_addr32[1],
1379                   src->s6_addr32[2], src->s6_addr32[3], srcp,
1380                   dest->s6_addr32[0], dest->s6_addr32[1],
1381                   dest->s6_addr32[2], dest->s6_addr32[3], destp,
1382                   sp->sk_state,
1383                   sk_wmem_alloc_get(sp),
1384                   sk_rmem_alloc_get(sp),
1385                   0, 0L, 0,
1386                   from_kuid_munged(seq_user_ns(seq), sock_i_uid(sp)),
1387                   0,
1388                   sock_i_ino(sp),
1389                   atomic_read(&sp->sk_refcnt), sp,
1390                   atomic_read(&sp->sk_drops));
1391}
1392
1393int udp6_seq_show(struct seq_file *seq, void *v)
1394{
1395        if (v == SEQ_START_TOKEN)
1396                seq_printf(seq,
1397                           "  sl  "
1398                           "local_address                         "
1399                           "remote_address                        "
1400                           "st tx_queue rx_queue tr tm->when retrnsmt"
1401                           "   uid  timeout inode ref pointer drops\n");
1402        else
1403                udp6_sock_seq_show(seq, v, ((struct udp_iter_state *)seq->private)->bucket);
1404        return 0;
1405}
1406
1407static const struct file_operations udp6_afinfo_seq_fops = {
1408        .owner    = THIS_MODULE,
1409        .open     = udp_seq_open,
1410        .read     = seq_read,
1411        .llseek   = seq_lseek,
1412        .release  = seq_release_net
1413};
1414
1415static struct udp_seq_afinfo udp6_seq_afinfo = {
1416        .name           = "udp6",
1417        .family         = AF_INET6,
1418        .udp_table      = &udp_table,
1419        .seq_fops       = &udp6_afinfo_seq_fops,
1420        .seq_ops        = {
1421                .show           = udp6_seq_show,
1422        },
1423};
1424
1425int __net_init udp6_proc_init(struct net *net)
1426{
1427        return udp_proc_register(net, &udp6_seq_afinfo);
1428}
1429
1430void udp6_proc_exit(struct net *net) {
1431        udp_proc_unregister(net, &udp6_seq_afinfo);
1432}
1433#endif /* CONFIG_PROC_FS */
1434
1435void udp_v6_clear_sk(struct sock *sk, int size)
1436{
1437        struct inet_sock *inet = inet_sk(sk);
1438
1439        /* we do not want to clear pinet6 field, because of RCU lookups */
1440        sk_prot_clear_portaddr_nulls(sk, offsetof(struct inet_sock, pinet6));
1441
1442        size -= offsetof(struct inet_sock, pinet6) + sizeof(inet->pinet6);
1443        memset(&inet->pinet6 + 1, 0, size);
1444}
1445
1446/* ------------------------------------------------------------------------ */
1447
1448struct proto udpv6_prot = {
1449        .name              = "UDPv6",
1450        .owner             = THIS_MODULE,
1451        .close             = udp_lib_close,
1452        .connect           = ip6_datagram_connect,
1453        .disconnect        = udp_disconnect,
1454        .ioctl             = udp_ioctl,
1455        .destroy           = udpv6_destroy_sock,
1456        .setsockopt        = udpv6_setsockopt,
1457        .getsockopt        = udpv6_getsockopt,
1458        .sendmsg           = udpv6_sendmsg,
1459        .recvmsg           = udpv6_recvmsg,
1460        .backlog_rcv       = __udpv6_queue_rcv_skb,
1461        .hash              = udp_lib_hash,
1462        .unhash            = udp_lib_unhash,
1463        .rehash            = udp_v6_rehash,
1464        .get_port          = udp_v6_get_port,
1465        .memory_allocated  = &udp_memory_allocated,
1466        .sysctl_mem        = sysctl_udp_mem,
1467        .sysctl_wmem       = &sysctl_udp_wmem_min,
1468        .sysctl_rmem       = &sysctl_udp_rmem_min,
1469        .obj_size          = sizeof(struct udp6_sock),
1470        .slab_flags        = SLAB_DESTROY_BY_RCU,
1471        .h.udp_table       = &udp_table,
1472#ifdef CONFIG_COMPAT
1473        .compat_setsockopt = compat_udpv6_setsockopt,
1474        .compat_getsockopt = compat_udpv6_getsockopt,
1475#endif
1476        .clear_sk          = udp_v6_clear_sk,
1477};
1478
1479static struct inet_protosw udpv6_protosw = {
1480        .type =      SOCK_DGRAM,
1481        .protocol =  IPPROTO_UDP,
1482        .prot =      &udpv6_prot,
1483        .ops =       &inet6_dgram_ops,
1484        .no_check =  UDP_CSUM_DEFAULT,
1485        .flags =     INET_PROTOSW_PERMANENT,
1486};
1487
1488
1489int __init udpv6_init(void)
1490{
1491        int ret;
1492
1493        ret = inet6_add_protocol(&udpv6_protocol, IPPROTO_UDP);
1494        if (ret)
1495                goto out;
1496
1497        ret = inet6_register_protosw(&udpv6_protosw);
1498        if (ret)
1499                goto out_udpv6_protocol;
1500out:
1501        return ret;
1502
1503out_udpv6_protocol:
1504        inet6_del_protocol(&udpv6_protocol, IPPROTO_UDP);
1505        goto out;
1506}
1507
1508void udpv6_exit(void)
1509{
1510        inet6_unregister_protosw(&udpv6_protosw);
1511        inet6_del_protocol(&udpv6_protocol, IPPROTO_UDP);
1512}
1513