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 unsigned int udp6_ehashfn(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 unsigned int udp6_portaddr_hash(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
 123
 124int udp_v6_get_port(struct sock *sk, unsigned short snum)
 125{
 126        unsigned int hash2_nulladdr =
 127                udp6_portaddr_hash(sock_net(sk), &in6addr_any, snum);
 128        unsigned int hash2_partial =
 129                udp6_portaddr_hash(sock_net(sk), &sk->sk_v6_rcv_saddr, 0);
 130
 131        /* precompute partial secondary hash */
 132        udp_sk(sk)->udp_portaddr_hash = hash2_partial;
 133        return udp_lib_get_port(sk, snum, ipv6_rcv_saddr_equal, hash2_nulladdr);
 134}
 135
 136static void udp_v6_rehash(struct sock *sk)
 137{
 138        u16 new_hash = udp6_portaddr_hash(sock_net(sk),
 139                                          &sk->sk_v6_rcv_saddr,
 140                                          inet_sk(sk)->inet_num);
 141
 142        udp_lib_rehash(sk, new_hash);
 143}
 144
 145static inline int compute_score(struct sock *sk, struct net *net,
 146                                unsigned short hnum,
 147                                const struct in6_addr *saddr, __be16 sport,
 148                                const struct in6_addr *daddr, __be16 dport,
 149                                int dif)
 150{
 151        int score = -1;
 152
 153        if (net_eq(sock_net(sk), net) && udp_sk(sk)->udp_port_hash == hnum &&
 154                        sk->sk_family == PF_INET6) {
 155                struct inet_sock *inet = inet_sk(sk);
 156
 157                score = 0;
 158                if (inet->inet_dport) {
 159                        if (inet->inet_dport != sport)
 160                                return -1;
 161                        score++;
 162                }
 163                if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr)) {
 164                        if (!ipv6_addr_equal(&sk->sk_v6_rcv_saddr, daddr))
 165                                return -1;
 166                        score++;
 167                }
 168                if (!ipv6_addr_any(&sk->sk_v6_daddr)) {
 169                        if (!ipv6_addr_equal(&sk->sk_v6_daddr, saddr))
 170                                return -1;
 171                        score++;
 172                }
 173                if (sk->sk_bound_dev_if) {
 174                        if (sk->sk_bound_dev_if != dif)
 175                                return -1;
 176                        score++;
 177                }
 178        }
 179        return score;
 180}
 181
 182#define SCORE2_MAX (1 + 1 + 1)
 183static inline int compute_score2(struct sock *sk, struct net *net,
 184                                const struct in6_addr *saddr, __be16 sport,
 185                                const struct in6_addr *daddr, unsigned short hnum,
 186                                int dif)
 187{
 188        int score = -1;
 189
 190        if (net_eq(sock_net(sk), net) && udp_sk(sk)->udp_port_hash == hnum &&
 191                        sk->sk_family == PF_INET6) {
 192                struct inet_sock *inet = inet_sk(sk);
 193
 194                if (!ipv6_addr_equal(&sk->sk_v6_rcv_saddr, daddr))
 195                        return -1;
 196                score = 0;
 197                if (inet->inet_dport) {
 198                        if (inet->inet_dport != sport)
 199                                return -1;
 200                        score++;
 201                }
 202                if (!ipv6_addr_any(&sk->sk_v6_daddr)) {
 203                        if (!ipv6_addr_equal(&sk->sk_v6_daddr, saddr))
 204                                return -1;
 205                        score++;
 206                }
 207                if (sk->sk_bound_dev_if) {
 208                        if (sk->sk_bound_dev_if != dif)
 209                                return -1;
 210                        score++;
 211                }
 212        }
 213        return score;
 214}
 215
 216
 217/* called with read_rcu_lock() */
 218static struct sock *udp6_lib_lookup2(struct net *net,
 219                const struct in6_addr *saddr, __be16 sport,
 220                const struct in6_addr *daddr, unsigned int hnum, int dif,
 221                struct udp_hslot *hslot2, unsigned int slot2)
 222{
 223        struct sock *sk, *result;
 224        struct hlist_nulls_node *node;
 225        int score, badness, matches = 0, reuseport = 0;
 226        u32 hash = 0;
 227
 228begin:
 229        result = NULL;
 230        badness = -1;
 231        udp_portaddr_for_each_entry_rcu(sk, node, &hslot2->head) {
 232                score = compute_score2(sk, net, saddr, sport,
 233                                      daddr, hnum, dif);
 234                if (score > badness) {
 235                        result = sk;
 236                        badness = score;
 237                        reuseport = sk->sk_reuseport;
 238                        if (reuseport) {
 239                                hash = udp6_ehashfn(net, daddr, hnum,
 240                                                    saddr, sport);
 241                                matches = 1;
 242                        } else if (score == SCORE2_MAX)
 243                                goto exact_match;
 244                } else if (score == badness && reuseport) {
 245                        matches++;
 246                        if (reciprocal_scale(hash, matches) == 0)
 247                                result = sk;
 248                        hash = next_pseudo_random32(hash);
 249                }
 250        }
 251        /*
 252         * if the nulls value we got at the end of this lookup is
 253         * not the expected one, we must restart lookup.
 254         * We probably met an item that was moved to another chain.
 255         */
 256        if (get_nulls_value(node) != slot2)
 257                goto begin;
 258
 259        if (result) {
 260exact_match:
 261                if (unlikely(!atomic_inc_not_zero_hint(&result->sk_refcnt, 2)))
 262                        result = NULL;
 263                else if (unlikely(compute_score2(result, net, saddr, sport,
 264                                  daddr, hnum, dif) < badness)) {
 265                        sock_put(result);
 266                        goto begin;
 267                }
 268        }
 269        return result;
 270}
 271
 272struct sock *__udp6_lib_lookup(struct net *net,
 273                                      const struct in6_addr *saddr, __be16 sport,
 274                                      const struct in6_addr *daddr, __be16 dport,
 275                                      int dif, struct udp_table *udptable)
 276{
 277        struct sock *sk, *result;
 278        struct hlist_nulls_node *node;
 279        unsigned short hnum = ntohs(dport);
 280        unsigned int hash2, slot2, slot = udp_hashfn(net, hnum, udptable->mask);
 281        struct udp_hslot *hslot2, *hslot = &udptable->hash[slot];
 282        int score, badness, matches = 0, reuseport = 0;
 283        u32 hash = 0;
 284
 285        rcu_read_lock();
 286        if (hslot->count > 10) {
 287                hash2 = udp6_portaddr_hash(net, daddr, hnum);
 288                slot2 = hash2 & udptable->mask;
 289                hslot2 = &udptable->hash2[slot2];
 290                if (hslot->count < hslot2->count)
 291                        goto begin;
 292
 293                result = udp6_lib_lookup2(net, saddr, sport,
 294                                          daddr, hnum, dif,
 295                                          hslot2, slot2);
 296                if (!result) {
 297                        hash2 = udp6_portaddr_hash(net, &in6addr_any, hnum);
 298                        slot2 = hash2 & udptable->mask;
 299                        hslot2 = &udptable->hash2[slot2];
 300                        if (hslot->count < hslot2->count)
 301                                goto begin;
 302
 303                        result = udp6_lib_lookup2(net, saddr, sport,
 304                                                  &in6addr_any, hnum, dif,
 305                                                  hslot2, slot2);
 306                }
 307                rcu_read_unlock();
 308                return result;
 309        }
 310begin:
 311        result = NULL;
 312        badness = -1;
 313        sk_nulls_for_each_rcu(sk, node, &hslot->head) {
 314                score = compute_score(sk, net, hnum, saddr, sport, daddr, dport, dif);
 315                if (score > badness) {
 316                        result = sk;
 317                        badness = score;
 318                        reuseport = sk->sk_reuseport;
 319                        if (reuseport) {
 320                                hash = udp6_ehashfn(net, daddr, hnum,
 321                                                    saddr, sport);
 322                                matches = 1;
 323                        }
 324                } else if (score == badness && reuseport) {
 325                        matches++;
 326                        if (reciprocal_scale(hash, matches) == 0)
 327                                result = sk;
 328                        hash = next_pseudo_random32(hash);
 329                }
 330        }
 331        /*
 332         * if the nulls value we got at the end of this lookup is
 333         * not the expected one, we must restart lookup.
 334         * We probably met an item that was moved to another chain.
 335         */
 336        if (get_nulls_value(node) != slot)
 337                goto begin;
 338
 339        if (result) {
 340                if (unlikely(!atomic_inc_not_zero_hint(&result->sk_refcnt, 2)))
 341                        result = NULL;
 342                else if (unlikely(compute_score(result, net, hnum, saddr, sport,
 343                                        daddr, dport, dif) < badness)) {
 344                        sock_put(result);
 345                        goto begin;
 346                }
 347        }
 348        rcu_read_unlock();
 349        return result;
 350}
 351EXPORT_SYMBOL_GPL(__udp6_lib_lookup);
 352
 353static struct sock *__udp6_lib_lookup_skb(struct sk_buff *skb,
 354                                          __be16 sport, __be16 dport,
 355                                          struct udp_table *udptable)
 356{
 357        struct sock *sk;
 358        const struct ipv6hdr *iph = ipv6_hdr(skb);
 359
 360        if (unlikely(sk = skb_steal_sock(skb)))
 361                return sk;
 362        return __udp6_lib_lookup(dev_net(skb_dst(skb)->dev), &iph->saddr, sport,
 363                                 &iph->daddr, dport, inet6_iif(skb),
 364                                 udptable);
 365}
 366
 367struct sock *udp6_lib_lookup(struct net *net, const struct in6_addr *saddr, __be16 sport,
 368                             const struct in6_addr *daddr, __be16 dport, int dif)
 369{
 370        return __udp6_lib_lookup(net, saddr, sport, daddr, dport, dif, &udp_table);
 371}
 372EXPORT_SYMBOL_GPL(udp6_lib_lookup);
 373
 374
 375/*
 376 *      This should be easy, if there is something there we
 377 *      return it, otherwise we block.
 378 */
 379
 380int udpv6_recvmsg(struct kiocb *iocb, struct sock *sk,
 381                  struct msghdr *msg, size_t len,
 382                  int noblock, int flags, int *addr_len)
 383{
 384        struct ipv6_pinfo *np = inet6_sk(sk);
 385        struct inet_sock *inet = inet_sk(sk);
 386        struct sk_buff *skb;
 387        unsigned int ulen, copied;
 388        int peeked, off = 0;
 389        int err;
 390        int is_udplite = IS_UDPLITE(sk);
 391        int is_udp4;
 392        bool slow;
 393
 394        if (flags & MSG_ERRQUEUE)
 395                return ipv6_recv_error(sk, msg, len, addr_len);
 396
 397        if (np->rxpmtu && np->rxopt.bits.rxpmtu)
 398                return ipv6_recv_rxpmtu(sk, msg, len, addr_len);
 399
 400try_again:
 401        skb = __skb_recv_datagram(sk, flags | (noblock ? MSG_DONTWAIT : 0),
 402                                  &peeked, &off, &err);
 403        if (!skb)
 404                goto out;
 405
 406        ulen = skb->len - sizeof(struct udphdr);
 407        copied = len;
 408        if (copied > ulen)
 409                copied = ulen;
 410        else if (copied < ulen)
 411                msg->msg_flags |= MSG_TRUNC;
 412
 413        is_udp4 = (skb->protocol == htons(ETH_P_IP));
 414
 415        /*
 416         * If checksum is needed at all, try to do it while copying the
 417         * data.  If the data is truncated, or if we only want a partial
 418         * coverage checksum (UDP-Lite), do it before the copy.
 419         */
 420
 421        if (copied < ulen || UDP_SKB_CB(skb)->partial_cov) {
 422                if (udp_lib_checksum_complete(skb))
 423                        goto csum_copy_err;
 424        }
 425
 426        if (skb_csum_unnecessary(skb))
 427                err = skb_copy_datagram_iovec(skb, sizeof(struct udphdr),
 428                                              msg->msg_iov, copied);
 429        else {
 430                err = skb_copy_and_csum_datagram_iovec(skb, sizeof(struct udphdr), msg->msg_iov);
 431                if (err == -EINVAL)
 432                        goto csum_copy_err;
 433        }
 434        if (unlikely(err)) {
 435                trace_kfree_skb(skb, udpv6_recvmsg);
 436                if (!peeked) {
 437                        atomic_inc(&sk->sk_drops);
 438                        if (is_udp4)
 439                                UDP_INC_STATS_USER(sock_net(sk),
 440                                                   UDP_MIB_INERRORS,
 441                                                   is_udplite);
 442                        else
 443                                UDP6_INC_STATS_USER(sock_net(sk),
 444                                                    UDP_MIB_INERRORS,
 445                                                    is_udplite);
 446                }
 447                goto out_free;
 448        }
 449        if (!peeked) {
 450                if (is_udp4)
 451                        UDP_INC_STATS_USER(sock_net(sk),
 452                                        UDP_MIB_INDATAGRAMS, is_udplite);
 453                else
 454                        UDP6_INC_STATS_USER(sock_net(sk),
 455                                        UDP_MIB_INDATAGRAMS, is_udplite);
 456        }
 457
 458        sock_recv_ts_and_drops(msg, sk, skb);
 459
 460        /* Copy the address. */
 461        if (msg->msg_name) {
 462                DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name);
 463                sin6->sin6_family = AF_INET6;
 464                sin6->sin6_port = udp_hdr(skb)->source;
 465                sin6->sin6_flowinfo = 0;
 466
 467                if (is_udp4) {
 468                        ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr,
 469                                               &sin6->sin6_addr);
 470                        sin6->sin6_scope_id = 0;
 471                } else {
 472                        sin6->sin6_addr = ipv6_hdr(skb)->saddr;
 473                        sin6->sin6_scope_id =
 474                                ipv6_iface_scope_id(&sin6->sin6_addr,
 475                                                    inet6_iif(skb));
 476                }
 477                *addr_len = sizeof(*sin6);
 478        }
 479
 480        if (np->rxopt.all)
 481                ip6_datagram_recv_common_ctl(sk, msg, skb);
 482
 483        if (is_udp4) {
 484                if (inet->cmsg_flags)
 485                        ip_cmsg_recv(msg, skb);
 486        } else {
 487                if (np->rxopt.all)
 488                        ip6_datagram_recv_specific_ctl(sk, msg, skb);
 489        }
 490
 491        err = copied;
 492        if (flags & MSG_TRUNC)
 493                err = ulen;
 494
 495out_free:
 496        skb_free_datagram_locked(sk, skb);
 497out:
 498        return err;
 499
 500csum_copy_err:
 501        slow = lock_sock_fast(sk);
 502        if (!skb_kill_datagram(sk, skb, flags)) {
 503                if (is_udp4) {
 504                        UDP_INC_STATS_USER(sock_net(sk),
 505                                        UDP_MIB_CSUMERRORS, is_udplite);
 506                        UDP_INC_STATS_USER(sock_net(sk),
 507                                        UDP_MIB_INERRORS, is_udplite);
 508                } else {
 509                        UDP6_INC_STATS_USER(sock_net(sk),
 510                                        UDP_MIB_CSUMERRORS, is_udplite);
 511                        UDP6_INC_STATS_USER(sock_net(sk),
 512                                        UDP_MIB_INERRORS, is_udplite);
 513                }
 514        }
 515        unlock_sock_fast(sk, slow);
 516
 517        if (noblock)
 518                return -EAGAIN;
 519
 520        /* starting over for a new packet */
 521        msg->msg_flags &= ~MSG_TRUNC;
 522        goto try_again;
 523}
 524
 525void __udp6_lib_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 526                    u8 type, u8 code, int offset, __be32 info,
 527                    struct udp_table *udptable)
 528{
 529        struct ipv6_pinfo *np;
 530        const struct ipv6hdr *hdr = (const struct ipv6hdr *)skb->data;
 531        const struct in6_addr *saddr = &hdr->saddr;
 532        const struct in6_addr *daddr = &hdr->daddr;
 533        struct udphdr *uh = (struct udphdr *)(skb->data+offset);
 534        struct sock *sk;
 535        int err;
 536        struct net *net = dev_net(skb->dev);
 537
 538        sk = __udp6_lib_lookup(net, daddr, uh->dest,
 539                               saddr, uh->source, inet6_iif(skb), udptable);
 540        if (sk == NULL) {
 541                ICMP6_INC_STATS_BH(net, __in6_dev_get(skb->dev),
 542                                   ICMP6_MIB_INERRORS);
 543                return;
 544        }
 545
 546        if (type == ICMPV6_PKT_TOOBIG) {
 547                if (!ip6_sk_accept_pmtu(sk))
 548                        goto out;
 549                ip6_sk_update_pmtu(skb, sk, info);
 550        }
 551        if (type == NDISC_REDIRECT) {
 552                ip6_sk_redirect(skb, sk);
 553                goto out;
 554        }
 555
 556        np = inet6_sk(sk);
 557
 558        if (!icmpv6_err_convert(type, code, &err) && !np->recverr)
 559                goto out;
 560
 561        if (sk->sk_state != TCP_ESTABLISHED && !np->recverr)
 562                goto out;
 563
 564        if (np->recverr)
 565                ipv6_icmp_error(sk, skb, err, uh->dest, ntohl(info), (u8 *)(uh+1));
 566
 567        sk->sk_err = err;
 568        sk->sk_error_report(sk);
 569out:
 570        sock_put(sk);
 571}
 572
 573static int __udpv6_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
 574{
 575        int rc;
 576
 577        if (!ipv6_addr_any(&sk->sk_v6_daddr)) {
 578                sock_rps_save_rxhash(sk, skb);
 579                sk_mark_napi_id(sk, skb);
 580        }
 581
 582        rc = sock_queue_rcv_skb(sk, skb);
 583        if (rc < 0) {
 584                int is_udplite = IS_UDPLITE(sk);
 585
 586                /* Note that an ENOMEM error is charged twice */
 587                if (rc == -ENOMEM)
 588                        UDP6_INC_STATS_BH(sock_net(sk),
 589                                        UDP_MIB_RCVBUFERRORS, is_udplite);
 590                UDP6_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
 591                kfree_skb(skb);
 592                return -1;
 593        }
 594        return 0;
 595}
 596
 597static __inline__ void udpv6_err(struct sk_buff *skb,
 598                                 struct inet6_skb_parm *opt, u8 type,
 599                                 u8 code, int offset, __be32 info)
 600{
 601        __udp6_lib_err(skb, opt, type, code, offset, info, &udp_table);
 602}
 603
 604static struct static_key udpv6_encap_needed __read_mostly;
 605void udpv6_encap_enable(void)
 606{
 607        if (!static_key_enabled(&udpv6_encap_needed))
 608                static_key_slow_inc(&udpv6_encap_needed);
 609}
 610EXPORT_SYMBOL(udpv6_encap_enable);
 611
 612int udpv6_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
 613{
 614        struct udp_sock *up = udp_sk(sk);
 615        int rc;
 616        int is_udplite = IS_UDPLITE(sk);
 617
 618        if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
 619                goto drop;
 620
 621        if (static_key_false(&udpv6_encap_needed) && up->encap_type) {
 622                int (*encap_rcv)(struct sock *sk, struct sk_buff *skb);
 623
 624                /*
 625                 * This is an encapsulation socket so pass the skb to
 626                 * the socket's udp_encap_rcv() hook. Otherwise, just
 627                 * fall through and pass this up the UDP socket.
 628                 * up->encap_rcv() returns the following value:
 629                 * =0 if skb was successfully passed to the encap
 630                 *    handler or was discarded by it.
 631                 * >0 if skb should be passed on to UDP.
 632                 * <0 if skb should be resubmitted as proto -N
 633                 */
 634
 635                /* if we're overly short, let UDP handle it */
 636                encap_rcv = ACCESS_ONCE(up->encap_rcv);
 637                if (skb->len > sizeof(struct udphdr) && encap_rcv != NULL) {
 638                        int ret;
 639
 640                        /* Verify checksum before giving to encap */
 641                        if (udp_lib_checksum_complete(skb))
 642                                goto csum_error;
 643
 644                        ret = encap_rcv(sk, skb);
 645                        if (ret <= 0) {
 646                                UDP_INC_STATS_BH(sock_net(sk),
 647                                                 UDP_MIB_INDATAGRAMS,
 648                                                 is_udplite);
 649                                return -ret;
 650                        }
 651                }
 652
 653                /* FALLTHROUGH -- it's a UDP Packet */
 654        }
 655
 656        /*
 657         * UDP-Lite specific tests, ignored on UDP sockets (see net/ipv4/udp.c).
 658         */
 659        if ((is_udplite & UDPLITE_RECV_CC)  &&  UDP_SKB_CB(skb)->partial_cov) {
 660
 661                if (up->pcrlen == 0) {          /* full coverage was set  */
 662                        LIMIT_NETDEBUG(KERN_WARNING "UDPLITE6: partial coverage"
 663                                " %d while full coverage %d requested\n",
 664                                UDP_SKB_CB(skb)->cscov, skb->len);
 665                        goto drop;
 666                }
 667                if (UDP_SKB_CB(skb)->cscov  <  up->pcrlen) {
 668                        LIMIT_NETDEBUG(KERN_WARNING "UDPLITE6: coverage %d "
 669                                                    "too small, need min %d\n",
 670                                       UDP_SKB_CB(skb)->cscov, up->pcrlen);
 671                        goto drop;
 672                }
 673        }
 674
 675        if (rcu_access_pointer(sk->sk_filter)) {
 676                if (udp_lib_checksum_complete(skb))
 677                        goto csum_error;
 678        }
 679
 680        if (sk_rcvqueues_full(sk, sk->sk_rcvbuf)) {
 681                UDP6_INC_STATS_BH(sock_net(sk),
 682                                  UDP_MIB_RCVBUFERRORS, is_udplite);
 683                goto drop;
 684        }
 685
 686        skb_dst_drop(skb);
 687
 688        bh_lock_sock(sk);
 689        rc = 0;
 690        if (!sock_owned_by_user(sk))
 691                rc = __udpv6_queue_rcv_skb(sk, skb);
 692        else if (sk_add_backlog(sk, skb, sk->sk_rcvbuf)) {
 693                bh_unlock_sock(sk);
 694                goto drop;
 695        }
 696        bh_unlock_sock(sk);
 697
 698        return rc;
 699
 700csum_error:
 701        UDP6_INC_STATS_BH(sock_net(sk), UDP_MIB_CSUMERRORS, is_udplite);
 702drop:
 703        UDP6_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
 704        atomic_inc(&sk->sk_drops);
 705        kfree_skb(skb);
 706        return -1;
 707}
 708
 709static bool __udp_v6_is_mcast_sock(struct net *net, struct sock *sk,
 710                                   __be16 loc_port, const struct in6_addr *loc_addr,
 711                                   __be16 rmt_port, const struct in6_addr *rmt_addr,
 712                                   int dif, unsigned short hnum)
 713{
 714        struct inet_sock *inet = inet_sk(sk);
 715
 716        if (!net_eq(sock_net(sk), net))
 717                return false;
 718
 719        if (udp_sk(sk)->udp_port_hash != hnum ||
 720            sk->sk_family != PF_INET6 ||
 721            (inet->inet_dport && inet->inet_dport != rmt_port) ||
 722            (!ipv6_addr_any(&sk->sk_v6_daddr) &&
 723                    !ipv6_addr_equal(&sk->sk_v6_daddr, rmt_addr)) ||
 724            (sk->sk_bound_dev_if && sk->sk_bound_dev_if != dif))
 725                return false;
 726        if (!inet6_mc_check(sk, loc_addr, rmt_addr))
 727                return false;
 728        return true;
 729}
 730
 731static void flush_stack(struct sock **stack, unsigned int count,
 732                        struct sk_buff *skb, unsigned int final)
 733{
 734        struct sk_buff *skb1 = NULL;
 735        struct sock *sk;
 736        unsigned int i;
 737
 738        for (i = 0; i < count; i++) {
 739                sk = stack[i];
 740                if (likely(skb1 == NULL))
 741                        skb1 = (i == final) ? skb : skb_clone(skb, GFP_ATOMIC);
 742                if (!skb1) {
 743                        atomic_inc(&sk->sk_drops);
 744                        UDP6_INC_STATS_BH(sock_net(sk), UDP_MIB_RCVBUFERRORS,
 745                                          IS_UDPLITE(sk));
 746                        UDP6_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS,
 747                                          IS_UDPLITE(sk));
 748                }
 749
 750                if (skb1 && udpv6_queue_rcv_skb(sk, skb1) <= 0)
 751                        skb1 = NULL;
 752                sock_put(sk);
 753        }
 754        if (unlikely(skb1))
 755                kfree_skb(skb1);
 756}
 757
 758static void udp6_csum_zero_error(struct sk_buff *skb)
 759{
 760        /* RFC 2460 section 8.1 says that we SHOULD log
 761         * this error. Well, it is reasonable.
 762         */
 763        LIMIT_NETDEBUG(KERN_INFO "IPv6: udp checksum is 0 for [%pI6c]:%u->[%pI6c]:%u\n",
 764                       &ipv6_hdr(skb)->saddr, ntohs(udp_hdr(skb)->source),
 765                       &ipv6_hdr(skb)->daddr, ntohs(udp_hdr(skb)->dest));
 766}
 767
 768/*
 769 * Note: called only from the BH handler context,
 770 * so we don't need to lock the hashes.
 771 */
 772static int __udp6_lib_mcast_deliver(struct net *net, struct sk_buff *skb,
 773                const struct in6_addr *saddr, const struct in6_addr *daddr,
 774                struct udp_table *udptable)
 775{
 776        struct sock *sk, *stack[256 / sizeof(struct sock *)];
 777        const struct udphdr *uh = udp_hdr(skb);
 778        struct hlist_nulls_node *node;
 779        unsigned short hnum = ntohs(uh->dest);
 780        struct udp_hslot *hslot = udp_hashslot(udptable, net, hnum);
 781        int dif = inet6_iif(skb);
 782        unsigned int count = 0, offset = offsetof(typeof(*sk), sk_nulls_node);
 783        unsigned int hash2 = 0, hash2_any = 0, use_hash2 = (hslot->count > 10);
 784
 785        if (use_hash2) {
 786                hash2_any = udp6_portaddr_hash(net, &in6addr_any, hnum) &
 787                            udp_table.mask;
 788                hash2 = udp6_portaddr_hash(net, daddr, hnum) & udp_table.mask;
 789start_lookup:
 790                hslot = &udp_table.hash2[hash2];
 791                offset = offsetof(typeof(*sk), __sk_common.skc_portaddr_node);
 792        }
 793
 794        spin_lock(&hslot->lock);
 795        sk_nulls_for_each_entry_offset(sk, node, &hslot->head, offset) {
 796                if (__udp_v6_is_mcast_sock(net, sk,
 797                                           uh->dest, daddr,
 798                                           uh->source, saddr,
 799                                           dif, hnum) &&
 800                    /* If zero checksum and no_check is not on for
 801                     * the socket then skip it.
 802                     */
 803                    (uh->check || udp_sk(sk)->no_check6_rx)) {
 804                        if (unlikely(count == ARRAY_SIZE(stack))) {
 805                                flush_stack(stack, count, skb, ~0);
 806                                count = 0;
 807                        }
 808                        stack[count++] = sk;
 809                        sock_hold(sk);
 810                }
 811        }
 812
 813        spin_unlock(&hslot->lock);
 814
 815        /* Also lookup *:port if we are using hash2 and haven't done so yet. */
 816        if (use_hash2 && hash2 != hash2_any) {
 817                hash2 = hash2_any;
 818                goto start_lookup;
 819        }
 820
 821        if (count) {
 822                flush_stack(stack, count, skb, count - 1);
 823        } else {
 824                kfree_skb(skb);
 825        }
 826        return 0;
 827}
 828
 829int __udp6_lib_rcv(struct sk_buff *skb, struct udp_table *udptable,
 830                   int proto)
 831{
 832        struct net *net = dev_net(skb->dev);
 833        struct sock *sk;
 834        struct udphdr *uh;
 835        const struct in6_addr *saddr, *daddr;
 836        u32 ulen = 0;
 837
 838        if (!pskb_may_pull(skb, sizeof(struct udphdr)))
 839                goto discard;
 840
 841        saddr = &ipv6_hdr(skb)->saddr;
 842        daddr = &ipv6_hdr(skb)->daddr;
 843        uh = udp_hdr(skb);
 844
 845        ulen = ntohs(uh->len);
 846        if (ulen > skb->len)
 847                goto short_packet;
 848
 849        if (proto == IPPROTO_UDP) {
 850                /* UDP validates ulen. */
 851
 852                /* Check for jumbo payload */
 853                if (ulen == 0)
 854                        ulen = skb->len;
 855
 856                if (ulen < sizeof(*uh))
 857                        goto short_packet;
 858
 859                if (ulen < skb->len) {
 860                        if (pskb_trim_rcsum(skb, ulen))
 861                                goto short_packet;
 862                        saddr = &ipv6_hdr(skb)->saddr;
 863                        daddr = &ipv6_hdr(skb)->daddr;
 864                        uh = udp_hdr(skb);
 865                }
 866        }
 867
 868        if (udp6_csum_init(skb, uh, proto))
 869                goto csum_error;
 870
 871        /*
 872         *      Multicast receive code
 873         */
 874        if (ipv6_addr_is_multicast(daddr))
 875                return __udp6_lib_mcast_deliver(net, skb,
 876                                saddr, daddr, udptable);
 877
 878        /* Unicast */
 879
 880        /*
 881         * check socket cache ... must talk to Alan about his plans
 882         * for sock caches... i'll skip this for now.
 883         */
 884        sk = __udp6_lib_lookup_skb(skb, uh->source, uh->dest, udptable);
 885        if (sk != NULL) {
 886                int ret;
 887
 888                if (!uh->check && !udp_sk(sk)->no_check6_rx) {
 889                        sock_put(sk);
 890                        udp6_csum_zero_error(skb);
 891                        goto csum_error;
 892                }
 893
 894                if (udp_sk(sk)->convert_csum && uh->check && !IS_UDPLITE(sk))
 895                        skb_checksum_try_convert(skb, IPPROTO_UDP, uh->check,
 896                                                 ip6_compute_pseudo);
 897
 898                ret = udpv6_queue_rcv_skb(sk, skb);
 899                sock_put(sk);
 900
 901                /* a return value > 0 means to resubmit the input, but
 902                 * it wants the return to be -protocol, or 0
 903                 */
 904                if (ret > 0)
 905                        return -ret;
 906
 907                return 0;
 908        }
 909
 910        if (!uh->check) {
 911                udp6_csum_zero_error(skb);
 912                goto csum_error;
 913        }
 914
 915        if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
 916                goto discard;
 917
 918        if (udp_lib_checksum_complete(skb))
 919                goto csum_error;
 920
 921        UDP6_INC_STATS_BH(net, UDP_MIB_NOPORTS, proto == IPPROTO_UDPLITE);
 922        icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0);
 923
 924        kfree_skb(skb);
 925        return 0;
 926
 927short_packet:
 928        LIMIT_NETDEBUG(KERN_DEBUG "UDP%sv6: short packet: From [%pI6c]:%u %d/%d to [%pI6c]:%u\n",
 929                       proto == IPPROTO_UDPLITE ? "-Lite" : "",
 930                       saddr,
 931                       ntohs(uh->source),
 932                       ulen,
 933                       skb->len,
 934                       daddr,
 935                       ntohs(uh->dest));
 936        goto discard;
 937csum_error:
 938        UDP6_INC_STATS_BH(net, UDP_MIB_CSUMERRORS, proto == IPPROTO_UDPLITE);
 939discard:
 940        UDP6_INC_STATS_BH(net, UDP_MIB_INERRORS, proto == IPPROTO_UDPLITE);
 941        kfree_skb(skb);
 942        return 0;
 943}
 944
 945static __inline__ int udpv6_rcv(struct sk_buff *skb)
 946{
 947        return __udp6_lib_rcv(skb, &udp_table, IPPROTO_UDP);
 948}
 949
 950/*
 951 * Throw away all pending data and cancel the corking. Socket is locked.
 952 */
 953static void udp_v6_flush_pending_frames(struct sock *sk)
 954{
 955        struct udp_sock *up = udp_sk(sk);
 956
 957        if (up->pending == AF_INET)
 958                udp_flush_pending_frames(sk);
 959        else if (up->pending) {
 960                up->len = 0;
 961                up->pending = 0;
 962                ip6_flush_pending_frames(sk);
 963        }
 964}
 965
 966/**
 967 *      udp6_hwcsum_outgoing  -  handle outgoing HW checksumming
 968 *      @sk:    socket we are sending on
 969 *      @skb:   sk_buff containing the filled-in UDP header
 970 *              (checksum field must be zeroed out)
 971 */
 972static void udp6_hwcsum_outgoing(struct sock *sk, struct sk_buff *skb,
 973                                 const struct in6_addr *saddr,
 974                                 const struct in6_addr *daddr, int len)
 975{
 976        unsigned int offset;
 977        struct udphdr *uh = udp_hdr(skb);
 978        __wsum csum = 0;
 979
 980        if (skb_queue_len(&sk->sk_write_queue) == 1) {
 981                /* Only one fragment on the socket.  */
 982                skb->csum_start = skb_transport_header(skb) - skb->head;
 983                skb->csum_offset = offsetof(struct udphdr, check);
 984                uh->check = ~csum_ipv6_magic(saddr, daddr, len, IPPROTO_UDP, 0);
 985        } else {
 986                /*
 987                 * HW-checksum won't work as there are two or more
 988                 * fragments on the socket so that all csums of sk_buffs
 989                 * should be together
 990                 */
 991                offset = skb_transport_offset(skb);
 992                skb->csum = skb_checksum(skb, offset, skb->len - offset, 0);
 993
 994                skb->ip_summed = CHECKSUM_NONE;
 995
 996                skb_queue_walk(&sk->sk_write_queue, skb) {
 997                        csum = csum_add(csum, skb->csum);
 998                }
 999
1000                uh->check = csum_ipv6_magic(saddr, daddr, len, IPPROTO_UDP,
1001                                            csum);
1002                if (uh->check == 0)
1003                        uh->check = CSUM_MANGLED_0;
1004        }
1005}
1006
1007/*
1008 *      Sending
1009 */
1010
1011static int udp_v6_push_pending_frames(struct sock *sk)
1012{
1013        struct sk_buff *skb;
1014        struct udphdr *uh;
1015        struct udp_sock  *up = udp_sk(sk);
1016        struct inet_sock *inet = inet_sk(sk);
1017        struct flowi6 *fl6;
1018        int err = 0;
1019        int is_udplite = IS_UDPLITE(sk);
1020        __wsum csum = 0;
1021
1022        if (up->pending == AF_INET)
1023                return udp_push_pending_frames(sk);
1024
1025        fl6 = &inet->cork.fl.u.ip6;
1026
1027        /* Grab the skbuff where UDP header space exists. */
1028        if ((skb = skb_peek(&sk->sk_write_queue)) == NULL)
1029                goto out;
1030
1031        /*
1032         * Create a UDP header
1033         */
1034        uh = udp_hdr(skb);
1035        uh->source = fl6->fl6_sport;
1036        uh->dest = fl6->fl6_dport;
1037        uh->len = htons(up->len);
1038        uh->check = 0;
1039
1040        if (is_udplite)
1041                csum = udplite_csum_outgoing(sk, skb);
1042        else if (up->no_check6_tx) {   /* UDP csum disabled */
1043                skb->ip_summed = CHECKSUM_NONE;
1044                goto send;
1045        } else if (skb->ip_summed == CHECKSUM_PARTIAL) { /* UDP hardware csum */
1046                udp6_hwcsum_outgoing(sk, skb, &fl6->saddr, &fl6->daddr,
1047                                     up->len);
1048                goto send;
1049        } else
1050                csum = udp_csum_outgoing(sk, skb);
1051
1052        /* add protocol-dependent pseudo-header */
1053        uh->check = csum_ipv6_magic(&fl6->saddr, &fl6->daddr,
1054                                    up->len, fl6->flowi6_proto, csum);
1055        if (uh->check == 0)
1056                uh->check = CSUM_MANGLED_0;
1057
1058send:
1059        err = ip6_push_pending_frames(sk);
1060        if (err) {
1061                if (err == -ENOBUFS && !inet6_sk(sk)->recverr) {
1062                        UDP6_INC_STATS_USER(sock_net(sk),
1063                                            UDP_MIB_SNDBUFERRORS, is_udplite);
1064                        err = 0;
1065                }
1066        } else
1067                UDP6_INC_STATS_USER(sock_net(sk),
1068                                    UDP_MIB_OUTDATAGRAMS, is_udplite);
1069out:
1070        up->len = 0;
1071        up->pending = 0;
1072        return err;
1073}
1074
1075int udpv6_sendmsg(struct kiocb *iocb, struct sock *sk,
1076                  struct msghdr *msg, size_t len)
1077{
1078        struct ipv6_txoptions opt_space;
1079        struct udp_sock *up = udp_sk(sk);
1080        struct inet_sock *inet = inet_sk(sk);
1081        struct ipv6_pinfo *np = inet6_sk(sk);
1082        DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name);
1083        struct in6_addr *daddr, *final_p, final;
1084        struct ipv6_txoptions *opt = NULL;
1085        struct ip6_flowlabel *flowlabel = NULL;
1086        struct flowi6 fl6;
1087        struct dst_entry *dst;
1088        int addr_len = msg->msg_namelen;
1089        int ulen = len;
1090        int hlimit = -1;
1091        int tclass = -1;
1092        int dontfrag = -1;
1093        int corkreq = up->corkflag || msg->msg_flags&MSG_MORE;
1094        int err;
1095        int connected = 0;
1096        int is_udplite = IS_UDPLITE(sk);
1097        int (*getfrag)(void *, char *, int, int, int, struct sk_buff *);
1098
1099        /* destination address check */
1100        if (sin6) {
1101                if (addr_len < offsetof(struct sockaddr, sa_data))
1102                        return -EINVAL;
1103
1104                switch (sin6->sin6_family) {
1105                case AF_INET6:
1106                        if (addr_len < SIN6_LEN_RFC2133)
1107                                return -EINVAL;
1108                        daddr = &sin6->sin6_addr;
1109                        break;
1110                case AF_INET:
1111                        goto do_udp_sendmsg;
1112                case AF_UNSPEC:
1113                        msg->msg_name = sin6 = NULL;
1114                        msg->msg_namelen = addr_len = 0;
1115                        daddr = NULL;
1116                        break;
1117                default:
1118                        return -EINVAL;
1119                }
1120        } else if (!up->pending) {
1121                if (sk->sk_state != TCP_ESTABLISHED)
1122                        return -EDESTADDRREQ;
1123                daddr = &sk->sk_v6_daddr;
1124        } else
1125                daddr = NULL;
1126
1127        if (daddr) {
1128                if (ipv6_addr_v4mapped(daddr)) {
1129                        struct sockaddr_in sin;
1130                        sin.sin_family = AF_INET;
1131                        sin.sin_port = sin6 ? sin6->sin6_port : inet->inet_dport;
1132                        sin.sin_addr.s_addr = daddr->s6_addr32[3];
1133                        msg->msg_name = &sin;
1134                        msg->msg_namelen = sizeof(sin);
1135do_udp_sendmsg:
1136                        if (__ipv6_only_sock(sk))
1137                                return -ENETUNREACH;
1138                        return udp_sendmsg(iocb, sk, msg, len);
1139                }
1140        }
1141
1142        if (up->pending == AF_INET)
1143                return udp_sendmsg(iocb, sk, msg, len);
1144
1145        /* Rough check on arithmetic overflow,
1146           better check is made in ip6_append_data().
1147           */
1148        if (len > INT_MAX - sizeof(struct udphdr))
1149                return -EMSGSIZE;
1150
1151        if (up->pending) {
1152                /*
1153                 * There are pending frames.
1154                 * The socket lock must be held while it's corked.
1155                 */
1156                lock_sock(sk);
1157                if (likely(up->pending)) {
1158                        if (unlikely(up->pending != AF_INET6)) {
1159                                release_sock(sk);
1160                                return -EAFNOSUPPORT;
1161                        }
1162                        dst = NULL;
1163                        goto do_append_data;
1164                }
1165                release_sock(sk);
1166        }
1167        ulen += sizeof(struct udphdr);
1168
1169        memset(&fl6, 0, sizeof(fl6));
1170
1171        if (sin6) {
1172                if (sin6->sin6_port == 0)
1173                        return -EINVAL;
1174
1175                fl6.fl6_dport = sin6->sin6_port;
1176                daddr = &sin6->sin6_addr;
1177
1178                if (np->sndflow) {
1179                        fl6.flowlabel = sin6->sin6_flowinfo&IPV6_FLOWINFO_MASK;
1180                        if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) {
1181                                flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
1182                                if (flowlabel == NULL)
1183                                        return -EINVAL;
1184                        }
1185                }
1186
1187                /*
1188                 * Otherwise it will be difficult to maintain
1189                 * sk->sk_dst_cache.
1190                 */
1191                if (sk->sk_state == TCP_ESTABLISHED &&
1192                    ipv6_addr_equal(daddr, &sk->sk_v6_daddr))
1193                        daddr = &sk->sk_v6_daddr;
1194
1195                if (addr_len >= sizeof(struct sockaddr_in6) &&
1196                    sin6->sin6_scope_id &&
1197                    __ipv6_addr_needs_scope_id(__ipv6_addr_type(daddr)))
1198                        fl6.flowi6_oif = sin6->sin6_scope_id;
1199        } else {
1200                if (sk->sk_state != TCP_ESTABLISHED)
1201                        return -EDESTADDRREQ;
1202
1203                fl6.fl6_dport = inet->inet_dport;
1204                daddr = &sk->sk_v6_daddr;
1205                fl6.flowlabel = np->flow_label;
1206                connected = 1;
1207        }
1208
1209        if (!fl6.flowi6_oif)
1210                fl6.flowi6_oif = sk->sk_bound_dev_if;
1211
1212        if (!fl6.flowi6_oif)
1213                fl6.flowi6_oif = np->sticky_pktinfo.ipi6_ifindex;
1214
1215        fl6.flowi6_mark = sk->sk_mark;
1216
1217        if (msg->msg_controllen) {
1218                opt = &opt_space;
1219                memset(opt, 0, sizeof(struct ipv6_txoptions));
1220                opt->tot_len = sizeof(*opt);
1221
1222                err = ip6_datagram_send_ctl(sock_net(sk), sk, msg, &fl6, opt,
1223                                            &hlimit, &tclass, &dontfrag);
1224                if (err < 0) {
1225                        fl6_sock_release(flowlabel);
1226                        return err;
1227                }
1228                if ((fl6.flowlabel&IPV6_FLOWLABEL_MASK) && !flowlabel) {
1229                        flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
1230                        if (flowlabel == NULL)
1231                                return -EINVAL;
1232                }
1233                if (!(opt->opt_nflen|opt->opt_flen))
1234                        opt = NULL;
1235                connected = 0;
1236        }
1237        if (opt == NULL)
1238                opt = np->opt;
1239        if (flowlabel)
1240                opt = fl6_merge_options(&opt_space, flowlabel, opt);
1241        opt = ipv6_fixup_options(&opt_space, opt);
1242
1243        fl6.flowi6_proto = sk->sk_protocol;
1244        if (!ipv6_addr_any(daddr))
1245                fl6.daddr = *daddr;
1246        else
1247                fl6.daddr.s6_addr[15] = 0x1; /* :: means loopback (BSD'ism) */
1248        if (ipv6_addr_any(&fl6.saddr) && !ipv6_addr_any(&np->saddr))
1249                fl6.saddr = np->saddr;
1250        fl6.fl6_sport = inet->inet_sport;
1251
1252        final_p = fl6_update_dst(&fl6, opt, &final);
1253        if (final_p)
1254                connected = 0;
1255
1256        if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr)) {
1257                fl6.flowi6_oif = np->mcast_oif;
1258                connected = 0;
1259        } else if (!fl6.flowi6_oif)
1260                fl6.flowi6_oif = np->ucast_oif;
1261
1262        security_sk_classify_flow(sk, flowi6_to_flowi(&fl6));
1263
1264        dst = ip6_sk_dst_lookup_flow(sk, &fl6, final_p);
1265        if (IS_ERR(dst)) {
1266                err = PTR_ERR(dst);
1267                dst = NULL;
1268                goto out;
1269        }
1270
1271        if (hlimit < 0)
1272                hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst);
1273
1274        if (tclass < 0)
1275                tclass = np->tclass;
1276
1277        if (msg->msg_flags&MSG_CONFIRM)
1278                goto do_confirm;
1279back_from_confirm:
1280
1281        lock_sock(sk);
1282        if (unlikely(up->pending)) {
1283                /* The socket is already corked while preparing it. */
1284                /* ... which is an evident application bug. --ANK */
1285                release_sock(sk);
1286
1287                LIMIT_NETDEBUG(KERN_DEBUG "udp cork app bug 2\n");
1288                err = -EINVAL;
1289                goto out;
1290        }
1291
1292        up->pending = AF_INET6;
1293
1294do_append_data:
1295        if (dontfrag < 0)
1296                dontfrag = np->dontfrag;
1297        up->len += ulen;
1298        getfrag  =  is_udplite ?  udplite_getfrag : ip_generic_getfrag;
1299        err = ip6_append_data(sk, getfrag, msg->msg_iov, ulen,
1300                sizeof(struct udphdr), hlimit, tclass, opt, &fl6,
1301                (struct rt6_info *)dst,
1302                corkreq ? msg->msg_flags|MSG_MORE : msg->msg_flags, dontfrag);
1303        if (err)
1304                udp_v6_flush_pending_frames(sk);
1305        else if (!corkreq)
1306                err = udp_v6_push_pending_frames(sk);
1307        else if (unlikely(skb_queue_empty(&sk->sk_write_queue)))
1308                up->pending = 0;
1309
1310        if (dst) {
1311                if (connected) {
1312                        ip6_dst_store(sk, dst,
1313                                      ipv6_addr_equal(&fl6.daddr, &sk->sk_v6_daddr) ?
1314                                      &sk->sk_v6_daddr : NULL,
1315#ifdef CONFIG_IPV6_SUBTREES
1316                                      ipv6_addr_equal(&fl6.saddr, &np->saddr) ?
1317                                      &np->saddr :
1318#endif
1319                                      NULL);
1320                } else {
1321                        dst_release(dst);
1322                }
1323                dst = NULL;
1324        }
1325
1326        if (err > 0)
1327                err = np->recverr ? net_xmit_errno(err) : 0;
1328        release_sock(sk);
1329out:
1330        dst_release(dst);
1331        fl6_sock_release(flowlabel);
1332        if (!err)
1333                return len;
1334        /*
1335         * ENOBUFS = no kernel mem, SOCK_NOSPACE = no sndbuf space.  Reporting
1336         * ENOBUFS might not be good (it's not tunable per se), but otherwise
1337         * we don't have a good statistic (IpOutDiscards but it can be too many
1338         * things).  We could add another new stat but at least for now that
1339         * seems like overkill.
1340         */
1341        if (err == -ENOBUFS || test_bit(SOCK_NOSPACE, &sk->sk_socket->flags)) {
1342                UDP6_INC_STATS_USER(sock_net(sk),
1343                                UDP_MIB_SNDBUFERRORS, is_udplite);
1344        }
1345        return err;
1346
1347do_confirm:
1348        dst_confirm(dst);
1349        if (!(msg->msg_flags&MSG_PROBE) || len)
1350                goto back_from_confirm;
1351        err = 0;
1352        goto out;
1353}
1354
1355void udpv6_destroy_sock(struct sock *sk)
1356{
1357        struct udp_sock *up = udp_sk(sk);
1358        lock_sock(sk);
1359        udp_v6_flush_pending_frames(sk);
1360        release_sock(sk);
1361
1362        if (static_key_false(&udpv6_encap_needed) && up->encap_type) {
1363                void (*encap_destroy)(struct sock *sk);
1364                encap_destroy = ACCESS_ONCE(up->encap_destroy);
1365                if (encap_destroy)
1366                        encap_destroy(sk);
1367        }
1368
1369        inet6_destroy_sock(sk);
1370}
1371
1372/*
1373 *      Socket option code for UDP
1374 */
1375int udpv6_setsockopt(struct sock *sk, int level, int optname,
1376                     char __user *optval, unsigned int optlen)
1377{
1378        if (level == SOL_UDP  ||  level == SOL_UDPLITE)
1379                return udp_lib_setsockopt(sk, level, optname, optval, optlen,
1380                                          udp_v6_push_pending_frames);
1381        return ipv6_setsockopt(sk, level, optname, optval, optlen);
1382}
1383
1384#ifdef CONFIG_COMPAT
1385int compat_udpv6_setsockopt(struct sock *sk, int level, int optname,
1386                            char __user *optval, unsigned int optlen)
1387{
1388        if (level == SOL_UDP  ||  level == SOL_UDPLITE)
1389                return udp_lib_setsockopt(sk, level, optname, optval, optlen,
1390                                          udp_v6_push_pending_frames);
1391        return compat_ipv6_setsockopt(sk, level, optname, optval, optlen);
1392}
1393#endif
1394
1395int udpv6_getsockopt(struct sock *sk, int level, int optname,
1396                     char __user *optval, int __user *optlen)
1397{
1398        if (level == SOL_UDP  ||  level == SOL_UDPLITE)
1399                return udp_lib_getsockopt(sk, level, optname, optval, optlen);
1400        return ipv6_getsockopt(sk, level, optname, optval, optlen);
1401}
1402
1403#ifdef CONFIG_COMPAT
1404int compat_udpv6_getsockopt(struct sock *sk, int level, int optname,
1405                            char __user *optval, int __user *optlen)
1406{
1407        if (level == SOL_UDP  ||  level == SOL_UDPLITE)
1408                return udp_lib_getsockopt(sk, level, optname, optval, optlen);
1409        return compat_ipv6_getsockopt(sk, level, optname, optval, optlen);
1410}
1411#endif
1412
1413static const struct inet6_protocol udpv6_protocol = {
1414        .handler        =       udpv6_rcv,
1415        .err_handler    =       udpv6_err,
1416        .flags          =       INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
1417};
1418
1419/* ------------------------------------------------------------------------ */
1420#ifdef CONFIG_PROC_FS
1421int udp6_seq_show(struct seq_file *seq, void *v)
1422{
1423        if (v == SEQ_START_TOKEN) {
1424                seq_puts(seq, IPV6_SEQ_DGRAM_HEADER);
1425        } else {
1426                int bucket = ((struct udp_iter_state *)seq->private)->bucket;
1427                struct inet_sock *inet = inet_sk(v);
1428                __u16 srcp = ntohs(inet->inet_sport);
1429                __u16 destp = ntohs(inet->inet_dport);
1430                ip6_dgram_sock_seq_show(seq, v, srcp, destp, bucket);
1431        }
1432        return 0;
1433}
1434
1435static const struct file_operations udp6_afinfo_seq_fops = {
1436        .owner    = THIS_MODULE,
1437        .open     = udp_seq_open,
1438        .read     = seq_read,
1439        .llseek   = seq_lseek,
1440        .release  = seq_release_net
1441};
1442
1443static struct udp_seq_afinfo udp6_seq_afinfo = {
1444        .name           = "udp6",
1445        .family         = AF_INET6,
1446        .udp_table      = &udp_table,
1447        .seq_fops       = &udp6_afinfo_seq_fops,
1448        .seq_ops        = {
1449                .show           = udp6_seq_show,
1450        },
1451};
1452
1453int __net_init udp6_proc_init(struct net *net)
1454{
1455        return udp_proc_register(net, &udp6_seq_afinfo);
1456}
1457
1458void udp6_proc_exit(struct net *net) {
1459        udp_proc_unregister(net, &udp6_seq_afinfo);
1460}
1461#endif /* CONFIG_PROC_FS */
1462
1463void udp_v6_clear_sk(struct sock *sk, int size)
1464{
1465        struct inet_sock *inet = inet_sk(sk);
1466
1467        /* we do not want to clear pinet6 field, because of RCU lookups */
1468        sk_prot_clear_portaddr_nulls(sk, offsetof(struct inet_sock, pinet6));
1469
1470        size -= offsetof(struct inet_sock, pinet6) + sizeof(inet->pinet6);
1471        memset(&inet->pinet6 + 1, 0, size);
1472}
1473
1474/* ------------------------------------------------------------------------ */
1475
1476struct proto udpv6_prot = {
1477        .name              = "UDPv6",
1478        .owner             = THIS_MODULE,
1479        .close             = udp_lib_close,
1480        .connect           = ip6_datagram_connect,
1481        .disconnect        = udp_disconnect,
1482        .ioctl             = udp_ioctl,
1483        .destroy           = udpv6_destroy_sock,
1484        .setsockopt        = udpv6_setsockopt,
1485        .getsockopt        = udpv6_getsockopt,
1486        .sendmsg           = udpv6_sendmsg,
1487        .recvmsg           = udpv6_recvmsg,
1488        .backlog_rcv       = __udpv6_queue_rcv_skb,
1489        .hash              = udp_lib_hash,
1490        .unhash            = udp_lib_unhash,
1491        .rehash            = udp_v6_rehash,
1492        .get_port          = udp_v6_get_port,
1493        .memory_allocated  = &udp_memory_allocated,
1494        .sysctl_mem        = sysctl_udp_mem,
1495        .sysctl_wmem       = &sysctl_udp_wmem_min,
1496        .sysctl_rmem       = &sysctl_udp_rmem_min,
1497        .obj_size          = sizeof(struct udp6_sock),
1498        .slab_flags        = SLAB_DESTROY_BY_RCU,
1499        .h.udp_table       = &udp_table,
1500#ifdef CONFIG_COMPAT
1501        .compat_setsockopt = compat_udpv6_setsockopt,
1502        .compat_getsockopt = compat_udpv6_getsockopt,
1503#endif
1504        .clear_sk          = udp_v6_clear_sk,
1505};
1506
1507static struct inet_protosw udpv6_protosw = {
1508        .type =      SOCK_DGRAM,
1509        .protocol =  IPPROTO_UDP,
1510        .prot =      &udpv6_prot,
1511        .ops =       &inet6_dgram_ops,
1512        .flags =     INET_PROTOSW_PERMANENT,
1513};
1514
1515
1516int __init udpv6_init(void)
1517{
1518        int ret;
1519
1520        ret = inet6_add_protocol(&udpv6_protocol, IPPROTO_UDP);
1521        if (ret)
1522                goto out;
1523
1524        ret = inet6_register_protosw(&udpv6_protosw);
1525        if (ret)
1526                goto out_udpv6_protocol;
1527out:
1528        return ret;
1529
1530out_udpv6_protocol:
1531        inet6_del_protocol(&udpv6_protocol, IPPROTO_UDP);
1532        goto out;
1533}
1534
1535void udpv6_exit(void)
1536{
1537        inet6_unregister_protosw(&udpv6_protosw);
1538        inet6_del_protocol(&udpv6_protocol, IPPROTO_UDP);
1539}
1540