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 <linux/uaccess.h>
  39
  40#include <net/addrconf.h>
  41#include <net/ndisc.h>
  42#include <net/protocol.h>
  43#include <net/transp_v6.h>
  44#include <net/ip6_route.h>
  45#include <net/raw.h>
  46#include <net/tcp_states.h>
  47#include <net/ip6_checksum.h>
  48#include <net/xfrm.h>
  49#include <net/inet_hashtables.h>
  50#include <net/inet6_hashtables.h>
  51#include <net/busy_poll.h>
  52#include <net/sock_reuseport.h>
  53
  54#include <linux/proc_fs.h>
  55#include <linux/seq_file.h>
  56#include <trace/events/skb.h>
  57#include "udp_impl.h"
  58
  59static bool udp6_lib_exact_dif_match(struct net *net, struct sk_buff *skb)
  60{
  61#if defined(CONFIG_NET_L3_MASTER_DEV)
  62        if (!net->ipv4.sysctl_udp_l3mdev_accept &&
  63            skb && ipv6_l3mdev_skb(IP6CB(skb)->flags))
  64                return true;
  65#endif
  66        return false;
  67}
  68
  69static u32 udp6_ehashfn(const struct net *net,
  70                        const struct in6_addr *laddr,
  71                        const u16 lport,
  72                        const struct in6_addr *faddr,
  73                        const __be16 fport)
  74{
  75        static u32 udp6_ehash_secret __read_mostly;
  76        static u32 udp_ipv6_hash_secret __read_mostly;
  77
  78        u32 lhash, fhash;
  79
  80        net_get_random_once(&udp6_ehash_secret,
  81                            sizeof(udp6_ehash_secret));
  82        net_get_random_once(&udp_ipv6_hash_secret,
  83                            sizeof(udp_ipv6_hash_secret));
  84
  85        lhash = (__force u32)laddr->s6_addr32[3];
  86        fhash = __ipv6_addr_jhash(faddr, udp_ipv6_hash_secret);
  87
  88        return __inet6_ehashfn(lhash, lport, fhash, fport,
  89                               udp_ipv6_hash_secret + net_hash_mix(net));
  90}
  91
  92static u32 udp6_portaddr_hash(const struct net *net,
  93                              const struct in6_addr *addr6,
  94                              unsigned int port)
  95{
  96        unsigned int hash, mix = net_hash_mix(net);
  97
  98        if (ipv6_addr_any(addr6))
  99                hash = jhash_1word(0, mix);
 100        else if (ipv6_addr_v4mapped(addr6))
 101                hash = jhash_1word((__force u32)addr6->s6_addr32[3], mix);
 102        else
 103                hash = jhash2((__force u32 *)addr6->s6_addr32, 4, mix);
 104
 105        return hash ^ port;
 106}
 107
 108int udp_v6_get_port(struct sock *sk, unsigned short snum)
 109{
 110        unsigned int hash2_nulladdr =
 111                udp6_portaddr_hash(sock_net(sk), &in6addr_any, snum);
 112        unsigned int hash2_partial =
 113                udp6_portaddr_hash(sock_net(sk), &sk->sk_v6_rcv_saddr, 0);
 114
 115        /* precompute partial secondary hash */
 116        udp_sk(sk)->udp_portaddr_hash = hash2_partial;
 117        return udp_lib_get_port(sk, snum, hash2_nulladdr);
 118}
 119
 120static void udp_v6_rehash(struct sock *sk)
 121{
 122        u16 new_hash = udp6_portaddr_hash(sock_net(sk),
 123                                          &sk->sk_v6_rcv_saddr,
 124                                          inet_sk(sk)->inet_num);
 125
 126        udp_lib_rehash(sk, new_hash);
 127}
 128
 129static int compute_score(struct sock *sk, struct net *net,
 130                         const struct in6_addr *saddr, __be16 sport,
 131                         const struct in6_addr *daddr, unsigned short hnum,
 132                         int dif, bool exact_dif)
 133{
 134        int score;
 135        struct inet_sock *inet;
 136
 137        if (!net_eq(sock_net(sk), net) ||
 138            udp_sk(sk)->udp_port_hash != hnum ||
 139            sk->sk_family != PF_INET6)
 140                return -1;
 141
 142        score = 0;
 143        inet = inet_sk(sk);
 144
 145        if (inet->inet_dport) {
 146                if (inet->inet_dport != sport)
 147                        return -1;
 148                score++;
 149        }
 150
 151        if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr)) {
 152                if (!ipv6_addr_equal(&sk->sk_v6_rcv_saddr, daddr))
 153                        return -1;
 154                score++;
 155        }
 156
 157        if (!ipv6_addr_any(&sk->sk_v6_daddr)) {
 158                if (!ipv6_addr_equal(&sk->sk_v6_daddr, saddr))
 159                        return -1;
 160                score++;
 161        }
 162
 163        if (sk->sk_bound_dev_if || exact_dif) {
 164                if (sk->sk_bound_dev_if != dif)
 165                        return -1;
 166                score++;
 167        }
 168
 169        if (sk->sk_incoming_cpu == raw_smp_processor_id())
 170                score++;
 171
 172        return score;
 173}
 174
 175/* called with rcu_read_lock() */
 176static struct sock *udp6_lib_lookup2(struct net *net,
 177                const struct in6_addr *saddr, __be16 sport,
 178                const struct in6_addr *daddr, unsigned int hnum, int dif,
 179                bool exact_dif, struct udp_hslot *hslot2,
 180                struct sk_buff *skb)
 181{
 182        struct sock *sk, *result;
 183        int score, badness, matches = 0, reuseport = 0;
 184        u32 hash = 0;
 185
 186        result = NULL;
 187        badness = -1;
 188        udp_portaddr_for_each_entry_rcu(sk, &hslot2->head) {
 189                score = compute_score(sk, net, saddr, sport,
 190                                      daddr, hnum, dif, exact_dif);
 191                if (score > badness) {
 192                        reuseport = sk->sk_reuseport;
 193                        if (reuseport) {
 194                                hash = udp6_ehashfn(net, daddr, hnum,
 195                                                    saddr, sport);
 196
 197                                result = reuseport_select_sock(sk, hash, skb,
 198                                                        sizeof(struct udphdr));
 199                                if (result)
 200                                        return result;
 201                                matches = 1;
 202                        }
 203                        result = sk;
 204                        badness = score;
 205                } else if (score == badness && reuseport) {
 206                        matches++;
 207                        if (reciprocal_scale(hash, matches) == 0)
 208                                result = sk;
 209                        hash = next_pseudo_random32(hash);
 210                }
 211        }
 212        return result;
 213}
 214
 215/* rcu_read_lock() must be held */
 216struct sock *__udp6_lib_lookup(struct net *net,
 217                                      const struct in6_addr *saddr, __be16 sport,
 218                                      const struct in6_addr *daddr, __be16 dport,
 219                                      int dif, struct udp_table *udptable,
 220                                      struct sk_buff *skb)
 221{
 222        struct sock *sk, *result;
 223        unsigned short hnum = ntohs(dport);
 224        unsigned int hash2, slot2, slot = udp_hashfn(net, hnum, udptable->mask);
 225        struct udp_hslot *hslot2, *hslot = &udptable->hash[slot];
 226        bool exact_dif = udp6_lib_exact_dif_match(net, skb);
 227        int score, badness, matches = 0, reuseport = 0;
 228        u32 hash = 0;
 229
 230        if (hslot->count > 10) {
 231                hash2 = udp6_portaddr_hash(net, daddr, hnum);
 232                slot2 = hash2 & udptable->mask;
 233                hslot2 = &udptable->hash2[slot2];
 234                if (hslot->count < hslot2->count)
 235                        goto begin;
 236
 237                result = udp6_lib_lookup2(net, saddr, sport,
 238                                          daddr, hnum, dif, exact_dif,
 239                                          hslot2, skb);
 240                if (!result) {
 241                        unsigned int old_slot2 = slot2;
 242                        hash2 = udp6_portaddr_hash(net, &in6addr_any, hnum);
 243                        slot2 = hash2 & udptable->mask;
 244                        /* avoid searching the same slot again. */
 245                        if (unlikely(slot2 == old_slot2))
 246                                return result;
 247
 248                        hslot2 = &udptable->hash2[slot2];
 249                        if (hslot->count < hslot2->count)
 250                                goto begin;
 251
 252                        result = udp6_lib_lookup2(net, saddr, sport,
 253                                                  daddr, hnum, dif,
 254                                                  exact_dif, hslot2,
 255                                                  skb);
 256                }
 257                return result;
 258        }
 259begin:
 260        result = NULL;
 261        badness = -1;
 262        sk_for_each_rcu(sk, &hslot->head) {
 263                score = compute_score(sk, net, saddr, sport, daddr, hnum, dif,
 264                                      exact_dif);
 265                if (score > badness) {
 266                        reuseport = sk->sk_reuseport;
 267                        if (reuseport) {
 268                                hash = udp6_ehashfn(net, daddr, hnum,
 269                                                    saddr, sport);
 270                                result = reuseport_select_sock(sk, hash, skb,
 271                                                        sizeof(struct udphdr));
 272                                if (result)
 273                                        return result;
 274                                matches = 1;
 275                        }
 276                        result = sk;
 277                        badness = score;
 278                } else if (score == badness && reuseport) {
 279                        matches++;
 280                        if (reciprocal_scale(hash, matches) == 0)
 281                                result = sk;
 282                        hash = next_pseudo_random32(hash);
 283                }
 284        }
 285        return result;
 286}
 287EXPORT_SYMBOL_GPL(__udp6_lib_lookup);
 288
 289static struct sock *__udp6_lib_lookup_skb(struct sk_buff *skb,
 290                                          __be16 sport, __be16 dport,
 291                                          struct udp_table *udptable)
 292{
 293        const struct ipv6hdr *iph = ipv6_hdr(skb);
 294
 295        return __udp6_lib_lookup(dev_net(skb->dev), &iph->saddr, sport,
 296                                 &iph->daddr, dport, inet6_iif(skb),
 297                                 udptable, skb);
 298}
 299
 300struct sock *udp6_lib_lookup_skb(struct sk_buff *skb,
 301                                 __be16 sport, __be16 dport)
 302{
 303        const struct ipv6hdr *iph = ipv6_hdr(skb);
 304
 305        return __udp6_lib_lookup(dev_net(skb->dev), &iph->saddr, sport,
 306                                 &iph->daddr, dport, inet6_iif(skb),
 307                                 &udp_table, skb);
 308}
 309EXPORT_SYMBOL_GPL(udp6_lib_lookup_skb);
 310
 311/* Must be called under rcu_read_lock().
 312 * Does increment socket refcount.
 313 */
 314#if IS_ENABLED(CONFIG_NETFILTER_XT_MATCH_SOCKET) || \
 315    IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TPROXY) || \
 316    IS_ENABLED(CONFIG_NF_SOCKET_IPV6)
 317struct sock *udp6_lib_lookup(struct net *net, const struct in6_addr *saddr, __be16 sport,
 318                             const struct in6_addr *daddr, __be16 dport, int dif)
 319{
 320        struct sock *sk;
 321
 322        sk =  __udp6_lib_lookup(net, saddr, sport, daddr, dport,
 323                                dif, &udp_table, NULL);
 324        if (sk && !refcount_inc_not_zero(&sk->sk_refcnt))
 325                sk = NULL;
 326        return sk;
 327}
 328EXPORT_SYMBOL_GPL(udp6_lib_lookup);
 329#endif
 330
 331/* do not use the scratch area len for jumbogram: their length execeeds the
 332 * scratch area space; note that the IP6CB flags is still in the first
 333 * cacheline, so checking for jumbograms is cheap
 334 */
 335static int udp6_skb_len(struct sk_buff *skb)
 336{
 337        return unlikely(inet6_is_jumbogram(skb)) ? skb->len : udp_skb_len(skb);
 338}
 339
 340/*
 341 *      This should be easy, if there is something there we
 342 *      return it, otherwise we block.
 343 */
 344
 345int udpv6_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
 346                  int noblock, int flags, int *addr_len)
 347{
 348        struct ipv6_pinfo *np = inet6_sk(sk);
 349        struct inet_sock *inet = inet_sk(sk);
 350        struct sk_buff *skb;
 351        unsigned int ulen, copied;
 352        int peeked, peeking, off;
 353        int err;
 354        int is_udplite = IS_UDPLITE(sk);
 355        bool checksum_valid = false;
 356        int is_udp4;
 357
 358        if (flags & MSG_ERRQUEUE)
 359                return ipv6_recv_error(sk, msg, len, addr_len);
 360
 361        if (np->rxpmtu && np->rxopt.bits.rxpmtu)
 362                return ipv6_recv_rxpmtu(sk, msg, len, addr_len);
 363
 364try_again:
 365        peeking = flags & MSG_PEEK;
 366        off = sk_peek_offset(sk, flags);
 367        skb = __skb_recv_udp(sk, flags, noblock, &peeked, &off, &err);
 368        if (!skb)
 369                return err;
 370
 371        ulen = udp6_skb_len(skb);
 372        copied = len;
 373        if (copied > ulen - off)
 374                copied = ulen - off;
 375        else if (copied < ulen)
 376                msg->msg_flags |= MSG_TRUNC;
 377
 378        is_udp4 = (skb->protocol == htons(ETH_P_IP));
 379
 380        /*
 381         * If checksum is needed at all, try to do it while copying the
 382         * data.  If the data is truncated, or if we only want a partial
 383         * coverage checksum (UDP-Lite), do it before the copy.
 384         */
 385
 386        if (copied < ulen || peeking ||
 387            (is_udplite && UDP_SKB_CB(skb)->partial_cov)) {
 388                checksum_valid = udp_skb_csum_unnecessary(skb) ||
 389                                !__udp_lib_checksum_complete(skb);
 390                if (!checksum_valid)
 391                        goto csum_copy_err;
 392        }
 393
 394        if (checksum_valid || udp_skb_csum_unnecessary(skb)) {
 395                if (udp_skb_is_linear(skb))
 396                        err = copy_linear_skb(skb, copied, off, &msg->msg_iter);
 397                else
 398                        err = skb_copy_datagram_msg(skb, off, msg, copied);
 399        } else {
 400                err = skb_copy_and_csum_datagram_msg(skb, off, msg);
 401                if (err == -EINVAL)
 402                        goto csum_copy_err;
 403        }
 404        if (unlikely(err)) {
 405                if (!peeked) {
 406                        atomic_inc(&sk->sk_drops);
 407                        if (is_udp4)
 408                                UDP_INC_STATS(sock_net(sk), UDP_MIB_INERRORS,
 409                                              is_udplite);
 410                        else
 411                                UDP6_INC_STATS(sock_net(sk), UDP_MIB_INERRORS,
 412                                               is_udplite);
 413                }
 414                kfree_skb(skb);
 415                return err;
 416        }
 417        if (!peeked) {
 418                if (is_udp4)
 419                        UDP_INC_STATS(sock_net(sk), UDP_MIB_INDATAGRAMS,
 420                                      is_udplite);
 421                else
 422                        UDP6_INC_STATS(sock_net(sk), UDP_MIB_INDATAGRAMS,
 423                                       is_udplite);
 424        }
 425
 426        sock_recv_ts_and_drops(msg, sk, skb);
 427
 428        /* Copy the address. */
 429        if (msg->msg_name) {
 430                DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name);
 431                sin6->sin6_family = AF_INET6;
 432                sin6->sin6_port = udp_hdr(skb)->source;
 433                sin6->sin6_flowinfo = 0;
 434
 435                if (is_udp4) {
 436                        ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr,
 437                                               &sin6->sin6_addr);
 438                        sin6->sin6_scope_id = 0;
 439                } else {
 440                        sin6->sin6_addr = ipv6_hdr(skb)->saddr;
 441                        sin6->sin6_scope_id =
 442                                ipv6_iface_scope_id(&sin6->sin6_addr,
 443                                                    inet6_iif(skb));
 444                }
 445                *addr_len = sizeof(*sin6);
 446        }
 447
 448        if (np->rxopt.all)
 449                ip6_datagram_recv_common_ctl(sk, msg, skb);
 450
 451        if (is_udp4) {
 452                if (inet->cmsg_flags)
 453                        ip_cmsg_recv_offset(msg, sk, skb,
 454                                            sizeof(struct udphdr), off);
 455        } else {
 456                if (np->rxopt.all)
 457                        ip6_datagram_recv_specific_ctl(sk, msg, skb);
 458        }
 459
 460        err = copied;
 461        if (flags & MSG_TRUNC)
 462                err = ulen;
 463
 464        skb_consume_udp(sk, skb, peeking ? -err : err);
 465        return err;
 466
 467csum_copy_err:
 468        if (!__sk_queue_drop_skb(sk, &udp_sk(sk)->reader_queue, skb, flags,
 469                                 udp_skb_destructor)) {
 470                if (is_udp4) {
 471                        UDP_INC_STATS(sock_net(sk),
 472                                      UDP_MIB_CSUMERRORS, is_udplite);
 473                        UDP_INC_STATS(sock_net(sk),
 474                                      UDP_MIB_INERRORS, is_udplite);
 475                } else {
 476                        UDP6_INC_STATS(sock_net(sk),
 477                                       UDP_MIB_CSUMERRORS, is_udplite);
 478                        UDP6_INC_STATS(sock_net(sk),
 479                                       UDP_MIB_INERRORS, is_udplite);
 480                }
 481        }
 482        kfree_skb(skb);
 483
 484        /* starting over for a new packet, but check if we need to yield */
 485        cond_resched();
 486        msg->msg_flags &= ~MSG_TRUNC;
 487        goto try_again;
 488}
 489
 490void __udp6_lib_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 491                    u8 type, u8 code, int offset, __be32 info,
 492                    struct udp_table *udptable)
 493{
 494        struct ipv6_pinfo *np;
 495        const struct ipv6hdr *hdr = (const struct ipv6hdr *)skb->data;
 496        const struct in6_addr *saddr = &hdr->saddr;
 497        const struct in6_addr *daddr = &hdr->daddr;
 498        struct udphdr *uh = (struct udphdr *)(skb->data+offset);
 499        struct sock *sk;
 500        int harderr;
 501        int err;
 502        struct net *net = dev_net(skb->dev);
 503
 504        sk = __udp6_lib_lookup(net, daddr, uh->dest, saddr, uh->source,
 505                               inet6_iif(skb), udptable, skb);
 506        if (!sk) {
 507                __ICMP6_INC_STATS(net, __in6_dev_get(skb->dev),
 508                                  ICMP6_MIB_INERRORS);
 509                return;
 510        }
 511
 512        harderr = icmpv6_err_convert(type, code, &err);
 513        np = inet6_sk(sk);
 514
 515        if (type == ICMPV6_PKT_TOOBIG) {
 516                if (!ip6_sk_accept_pmtu(sk))
 517                        goto out;
 518                ip6_sk_update_pmtu(skb, sk, info);
 519                if (np->pmtudisc != IPV6_PMTUDISC_DONT)
 520                        harderr = 1;
 521        }
 522        if (type == NDISC_REDIRECT) {
 523                ip6_sk_redirect(skb, sk);
 524                goto out;
 525        }
 526
 527        if (!np->recverr) {
 528                if (!harderr || sk->sk_state != TCP_ESTABLISHED)
 529                        goto out;
 530        } else {
 531                ipv6_icmp_error(sk, skb, err, uh->dest, ntohl(info), (u8 *)(uh+1));
 532        }
 533
 534        sk->sk_err = err;
 535        sk->sk_error_report(sk);
 536out:
 537        return;
 538}
 539
 540static int __udpv6_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
 541{
 542        int rc;
 543
 544        if (!ipv6_addr_any(&sk->sk_v6_daddr)) {
 545                sock_rps_save_rxhash(sk, skb);
 546                sk_mark_napi_id(sk, skb);
 547                sk_incoming_cpu_update(sk);
 548        } else {
 549                sk_mark_napi_id_once(sk, skb);
 550        }
 551
 552        rc = __udp_enqueue_schedule_skb(sk, skb);
 553        if (rc < 0) {
 554                int is_udplite = IS_UDPLITE(sk);
 555
 556                /* Note that an ENOMEM error is charged twice */
 557                if (rc == -ENOMEM)
 558                        UDP6_INC_STATS(sock_net(sk),
 559                                         UDP_MIB_RCVBUFERRORS, is_udplite);
 560                UDP6_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
 561                kfree_skb(skb);
 562                return -1;
 563        }
 564
 565        return 0;
 566}
 567
 568static __inline__ void udpv6_err(struct sk_buff *skb,
 569                                 struct inet6_skb_parm *opt, u8 type,
 570                                 u8 code, int offset, __be32 info)
 571{
 572        __udp6_lib_err(skb, opt, type, code, offset, info, &udp_table);
 573}
 574
 575static struct static_key udpv6_encap_needed __read_mostly;
 576void udpv6_encap_enable(void)
 577{
 578        if (!static_key_enabled(&udpv6_encap_needed))
 579                static_key_slow_inc(&udpv6_encap_needed);
 580}
 581EXPORT_SYMBOL(udpv6_encap_enable);
 582
 583static int udpv6_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
 584{
 585        struct udp_sock *up = udp_sk(sk);
 586        int is_udplite = IS_UDPLITE(sk);
 587
 588        if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
 589                goto drop;
 590
 591        if (static_key_false(&udpv6_encap_needed) && up->encap_type) {
 592                int (*encap_rcv)(struct sock *sk, struct sk_buff *skb);
 593
 594                /*
 595                 * This is an encapsulation socket so pass the skb to
 596                 * the socket's udp_encap_rcv() hook. Otherwise, just
 597                 * fall through and pass this up the UDP socket.
 598                 * up->encap_rcv() returns the following value:
 599                 * =0 if skb was successfully passed to the encap
 600                 *    handler or was discarded by it.
 601                 * >0 if skb should be passed on to UDP.
 602                 * <0 if skb should be resubmitted as proto -N
 603                 */
 604
 605                /* if we're overly short, let UDP handle it */
 606                encap_rcv = ACCESS_ONCE(up->encap_rcv);
 607                if (encap_rcv) {
 608                        int ret;
 609
 610                        /* Verify checksum before giving to encap */
 611                        if (udp_lib_checksum_complete(skb))
 612                                goto csum_error;
 613
 614                        ret = encap_rcv(sk, skb);
 615                        if (ret <= 0) {
 616                                __UDP_INC_STATS(sock_net(sk),
 617                                                UDP_MIB_INDATAGRAMS,
 618                                                is_udplite);
 619                                return -ret;
 620                        }
 621                }
 622
 623                /* FALLTHROUGH -- it's a UDP Packet */
 624        }
 625
 626        /*
 627         * UDP-Lite specific tests, ignored on UDP sockets (see net/ipv4/udp.c).
 628         */
 629        if ((is_udplite & UDPLITE_RECV_CC)  &&  UDP_SKB_CB(skb)->partial_cov) {
 630
 631                if (up->pcrlen == 0) {          /* full coverage was set  */
 632                        net_dbg_ratelimited("UDPLITE6: partial coverage %d while full coverage %d requested\n",
 633                                            UDP_SKB_CB(skb)->cscov, skb->len);
 634                        goto drop;
 635                }
 636                if (UDP_SKB_CB(skb)->cscov  <  up->pcrlen) {
 637                        net_dbg_ratelimited("UDPLITE6: coverage %d too small, need min %d\n",
 638                                            UDP_SKB_CB(skb)->cscov, up->pcrlen);
 639                        goto drop;
 640                }
 641        }
 642
 643        prefetch(&sk->sk_rmem_alloc);
 644        if (rcu_access_pointer(sk->sk_filter) &&
 645            udp_lib_checksum_complete(skb))
 646                goto csum_error;
 647
 648        if (sk_filter_trim_cap(sk, skb, sizeof(struct udphdr)))
 649                goto drop;
 650
 651        udp_csum_pull_header(skb);
 652
 653        skb_dst_drop(skb);
 654
 655        return __udpv6_queue_rcv_skb(sk, skb);
 656
 657csum_error:
 658        __UDP6_INC_STATS(sock_net(sk), UDP_MIB_CSUMERRORS, is_udplite);
 659drop:
 660        __UDP6_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
 661        atomic_inc(&sk->sk_drops);
 662        kfree_skb(skb);
 663        return -1;
 664}
 665
 666static bool __udp_v6_is_mcast_sock(struct net *net, struct sock *sk,
 667                                   __be16 loc_port, const struct in6_addr *loc_addr,
 668                                   __be16 rmt_port, const struct in6_addr *rmt_addr,
 669                                   int dif, unsigned short hnum)
 670{
 671        struct inet_sock *inet = inet_sk(sk);
 672
 673        if (!net_eq(sock_net(sk), net))
 674                return false;
 675
 676        if (udp_sk(sk)->udp_port_hash != hnum ||
 677            sk->sk_family != PF_INET6 ||
 678            (inet->inet_dport && inet->inet_dport != rmt_port) ||
 679            (!ipv6_addr_any(&sk->sk_v6_daddr) &&
 680                    !ipv6_addr_equal(&sk->sk_v6_daddr, rmt_addr)) ||
 681            (sk->sk_bound_dev_if && sk->sk_bound_dev_if != dif) ||
 682            (!ipv6_addr_any(&sk->sk_v6_rcv_saddr) &&
 683                    !ipv6_addr_equal(&sk->sk_v6_rcv_saddr, loc_addr)))
 684                return false;
 685        if (!inet6_mc_check(sk, loc_addr, rmt_addr))
 686                return false;
 687        return true;
 688}
 689
 690static void udp6_csum_zero_error(struct sk_buff *skb)
 691{
 692        /* RFC 2460 section 8.1 says that we SHOULD log
 693         * this error. Well, it is reasonable.
 694         */
 695        net_dbg_ratelimited("IPv6: udp checksum is 0 for [%pI6c]:%u->[%pI6c]:%u\n",
 696                            &ipv6_hdr(skb)->saddr, ntohs(udp_hdr(skb)->source),
 697                            &ipv6_hdr(skb)->daddr, ntohs(udp_hdr(skb)->dest));
 698}
 699
 700/*
 701 * Note: called only from the BH handler context,
 702 * so we don't need to lock the hashes.
 703 */
 704static int __udp6_lib_mcast_deliver(struct net *net, struct sk_buff *skb,
 705                const struct in6_addr *saddr, const struct in6_addr *daddr,
 706                struct udp_table *udptable, int proto)
 707{
 708        struct sock *sk, *first = NULL;
 709        const struct udphdr *uh = udp_hdr(skb);
 710        unsigned short hnum = ntohs(uh->dest);
 711        struct udp_hslot *hslot = udp_hashslot(udptable, net, hnum);
 712        unsigned int offset = offsetof(typeof(*sk), sk_node);
 713        unsigned int hash2 = 0, hash2_any = 0, use_hash2 = (hslot->count > 10);
 714        int dif = inet6_iif(skb);
 715        struct hlist_node *node;
 716        struct sk_buff *nskb;
 717
 718        if (use_hash2) {
 719                hash2_any = udp6_portaddr_hash(net, &in6addr_any, hnum) &
 720                            udptable->mask;
 721                hash2 = udp6_portaddr_hash(net, daddr, hnum) & udptable->mask;
 722start_lookup:
 723                hslot = &udptable->hash2[hash2];
 724                offset = offsetof(typeof(*sk), __sk_common.skc_portaddr_node);
 725        }
 726
 727        sk_for_each_entry_offset_rcu(sk, node, &hslot->head, offset) {
 728                if (!__udp_v6_is_mcast_sock(net, sk, uh->dest, daddr,
 729                                            uh->source, saddr, dif, hnum))
 730                        continue;
 731                /* If zero checksum and no_check is not on for
 732                 * the socket then skip it.
 733                 */
 734                if (!uh->check && !udp_sk(sk)->no_check6_rx)
 735                        continue;
 736                if (!first) {
 737                        first = sk;
 738                        continue;
 739                }
 740                nskb = skb_clone(skb, GFP_ATOMIC);
 741                if (unlikely(!nskb)) {
 742                        atomic_inc(&sk->sk_drops);
 743                        __UDP6_INC_STATS(net, UDP_MIB_RCVBUFERRORS,
 744                                         IS_UDPLITE(sk));
 745                        __UDP6_INC_STATS(net, UDP_MIB_INERRORS,
 746                                         IS_UDPLITE(sk));
 747                        continue;
 748                }
 749
 750                if (udpv6_queue_rcv_skb(sk, nskb) > 0)
 751                        consume_skb(nskb);
 752        }
 753
 754        /* Also lookup *:port if we are using hash2 and haven't done so yet. */
 755        if (use_hash2 && hash2 != hash2_any) {
 756                hash2 = hash2_any;
 757                goto start_lookup;
 758        }
 759
 760        if (first) {
 761                if (udpv6_queue_rcv_skb(first, skb) > 0)
 762                        consume_skb(skb);
 763        } else {
 764                kfree_skb(skb);
 765                __UDP6_INC_STATS(net, UDP_MIB_IGNOREDMULTI,
 766                                 proto == IPPROTO_UDPLITE);
 767        }
 768        return 0;
 769}
 770
 771static void udp6_sk_rx_dst_set(struct sock *sk, struct dst_entry *dst)
 772{
 773        if (udp_sk_rx_dst_set(sk, dst)) {
 774                const struct rt6_info *rt = (const struct rt6_info *)dst;
 775
 776                inet6_sk(sk)->rx_dst_cookie = rt6_get_cookie(rt);
 777        }
 778}
 779
 780int __udp6_lib_rcv(struct sk_buff *skb, struct udp_table *udptable,
 781                   int proto)
 782{
 783        const struct in6_addr *saddr, *daddr;
 784        struct net *net = dev_net(skb->dev);
 785        struct udphdr *uh;
 786        struct sock *sk;
 787        u32 ulen = 0;
 788
 789        if (!pskb_may_pull(skb, sizeof(struct udphdr)))
 790                goto discard;
 791
 792        saddr = &ipv6_hdr(skb)->saddr;
 793        daddr = &ipv6_hdr(skb)->daddr;
 794        uh = udp_hdr(skb);
 795
 796        ulen = ntohs(uh->len);
 797        if (ulen > skb->len)
 798                goto short_packet;
 799
 800        if (proto == IPPROTO_UDP) {
 801                /* UDP validates ulen. */
 802
 803                /* Check for jumbo payload */
 804                if (ulen == 0)
 805                        ulen = skb->len;
 806
 807                if (ulen < sizeof(*uh))
 808                        goto short_packet;
 809
 810                if (ulen < skb->len) {
 811                        if (pskb_trim_rcsum(skb, ulen))
 812                                goto short_packet;
 813                        saddr = &ipv6_hdr(skb)->saddr;
 814                        daddr = &ipv6_hdr(skb)->daddr;
 815                        uh = udp_hdr(skb);
 816                }
 817        }
 818
 819        if (udp6_csum_init(skb, uh, proto))
 820                goto csum_error;
 821
 822        /* Check if the socket is already available, e.g. due to early demux */
 823        sk = skb_steal_sock(skb);
 824        if (sk) {
 825                struct dst_entry *dst = skb_dst(skb);
 826                int ret;
 827
 828                if (unlikely(sk->sk_rx_dst != dst))
 829                        udp6_sk_rx_dst_set(sk, dst);
 830
 831                ret = udpv6_queue_rcv_skb(sk, skb);
 832                sock_put(sk);
 833
 834                /* a return value > 0 means to resubmit the input */
 835                if (ret > 0)
 836                        return ret;
 837                return 0;
 838        }
 839
 840        /*
 841         *      Multicast receive code
 842         */
 843        if (ipv6_addr_is_multicast(daddr))
 844                return __udp6_lib_mcast_deliver(net, skb,
 845                                saddr, daddr, udptable, proto);
 846
 847        /* Unicast */
 848        sk = __udp6_lib_lookup_skb(skb, uh->source, uh->dest, udptable);
 849        if (sk) {
 850                int ret;
 851
 852                if (!uh->check && !udp_sk(sk)->no_check6_rx) {
 853                        udp6_csum_zero_error(skb);
 854                        goto csum_error;
 855                }
 856
 857                if (inet_get_convert_csum(sk) && uh->check && !IS_UDPLITE(sk))
 858                        skb_checksum_try_convert(skb, IPPROTO_UDP, uh->check,
 859                                                 ip6_compute_pseudo);
 860
 861                ret = udpv6_queue_rcv_skb(sk, skb);
 862
 863                /* a return value > 0 means to resubmit the input */
 864                if (ret > 0)
 865                        return ret;
 866
 867                return 0;
 868        }
 869
 870        if (!uh->check) {
 871                udp6_csum_zero_error(skb);
 872                goto csum_error;
 873        }
 874
 875        if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
 876                goto discard;
 877
 878        if (udp_lib_checksum_complete(skb))
 879                goto csum_error;
 880
 881        __UDP6_INC_STATS(net, UDP_MIB_NOPORTS, proto == IPPROTO_UDPLITE);
 882        icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0);
 883
 884        kfree_skb(skb);
 885        return 0;
 886
 887short_packet:
 888        net_dbg_ratelimited("UDP%sv6: short packet: From [%pI6c]:%u %d/%d to [%pI6c]:%u\n",
 889                            proto == IPPROTO_UDPLITE ? "-Lite" : "",
 890                            saddr, ntohs(uh->source),
 891                            ulen, skb->len,
 892                            daddr, ntohs(uh->dest));
 893        goto discard;
 894csum_error:
 895        __UDP6_INC_STATS(net, UDP_MIB_CSUMERRORS, proto == IPPROTO_UDPLITE);
 896discard:
 897        __UDP6_INC_STATS(net, UDP_MIB_INERRORS, proto == IPPROTO_UDPLITE);
 898        kfree_skb(skb);
 899        return 0;
 900}
 901
 902
 903static struct sock *__udp6_lib_demux_lookup(struct net *net,
 904                        __be16 loc_port, const struct in6_addr *loc_addr,
 905                        __be16 rmt_port, const struct in6_addr *rmt_addr,
 906                        int dif)
 907{
 908        unsigned short hnum = ntohs(loc_port);
 909        unsigned int hash2 = udp6_portaddr_hash(net, loc_addr, hnum);
 910        unsigned int slot2 = hash2 & udp_table.mask;
 911        struct udp_hslot *hslot2 = &udp_table.hash2[slot2];
 912        const __portpair ports = INET_COMBINED_PORTS(rmt_port, hnum);
 913        struct sock *sk;
 914
 915        udp_portaddr_for_each_entry_rcu(sk, &hslot2->head) {
 916                if (sk->sk_state == TCP_ESTABLISHED &&
 917                    INET6_MATCH(sk, net, rmt_addr, loc_addr, ports, dif))
 918                        return sk;
 919                /* Only check first socket in chain */
 920                break;
 921        }
 922        return NULL;
 923}
 924
 925static void udp_v6_early_demux(struct sk_buff *skb)
 926{
 927        struct net *net = dev_net(skb->dev);
 928        const struct udphdr *uh;
 929        struct sock *sk;
 930        struct dst_entry *dst;
 931        int dif = skb->dev->ifindex;
 932
 933        if (!pskb_may_pull(skb, skb_transport_offset(skb) +
 934            sizeof(struct udphdr)))
 935                return;
 936
 937        uh = udp_hdr(skb);
 938
 939        if (skb->pkt_type == PACKET_HOST)
 940                sk = __udp6_lib_demux_lookup(net, uh->dest,
 941                                             &ipv6_hdr(skb)->daddr,
 942                                             uh->source, &ipv6_hdr(skb)->saddr,
 943                                             dif);
 944        else
 945                return;
 946
 947        if (!sk || !refcount_inc_not_zero(&sk->sk_refcnt))
 948                return;
 949
 950        skb->sk = sk;
 951        skb->destructor = sock_efree;
 952        dst = READ_ONCE(sk->sk_rx_dst);
 953
 954        if (dst)
 955                dst = dst_check(dst, inet6_sk(sk)->rx_dst_cookie);
 956        if (dst) {
 957                /* set noref for now.
 958                 * any place which wants to hold dst has to call
 959                 * dst_hold_safe()
 960                 */
 961                skb_dst_set_noref(skb, dst);
 962        }
 963}
 964
 965static __inline__ int udpv6_rcv(struct sk_buff *skb)
 966{
 967        return __udp6_lib_rcv(skb, &udp_table, IPPROTO_UDP);
 968}
 969
 970/*
 971 * Throw away all pending data and cancel the corking. Socket is locked.
 972 */
 973static void udp_v6_flush_pending_frames(struct sock *sk)
 974{
 975        struct udp_sock *up = udp_sk(sk);
 976
 977        if (up->pending == AF_INET)
 978                udp_flush_pending_frames(sk);
 979        else if (up->pending) {
 980                up->len = 0;
 981                up->pending = 0;
 982                ip6_flush_pending_frames(sk);
 983        }
 984}
 985
 986/**
 987 *      udp6_hwcsum_outgoing  -  handle outgoing HW checksumming
 988 *      @sk:    socket we are sending on
 989 *      @skb:   sk_buff containing the filled-in UDP header
 990 *              (checksum field must be zeroed out)
 991 */
 992static void udp6_hwcsum_outgoing(struct sock *sk, struct sk_buff *skb,
 993                                 const struct in6_addr *saddr,
 994                                 const struct in6_addr *daddr, int len)
 995{
 996        unsigned int offset;
 997        struct udphdr *uh = udp_hdr(skb);
 998        struct sk_buff *frags = skb_shinfo(skb)->frag_list;
 999        __wsum csum = 0;
1000
1001        if (!frags) {
1002                /* Only one fragment on the socket.  */
1003                skb->csum_start = skb_transport_header(skb) - skb->head;
1004                skb->csum_offset = offsetof(struct udphdr, check);
1005                uh->check = ~csum_ipv6_magic(saddr, daddr, len, IPPROTO_UDP, 0);
1006        } else {
1007                /*
1008                 * HW-checksum won't work as there are two or more
1009                 * fragments on the socket so that all csums of sk_buffs
1010                 * should be together
1011                 */
1012                offset = skb_transport_offset(skb);
1013                skb->csum = skb_checksum(skb, offset, skb->len - offset, 0);
1014
1015                skb->ip_summed = CHECKSUM_NONE;
1016
1017                do {
1018                        csum = csum_add(csum, frags->csum);
1019                } while ((frags = frags->next));
1020
1021                uh->check = csum_ipv6_magic(saddr, daddr, len, IPPROTO_UDP,
1022                                            csum);
1023                if (uh->check == 0)
1024                        uh->check = CSUM_MANGLED_0;
1025        }
1026}
1027
1028/*
1029 *      Sending
1030 */
1031
1032static int udp_v6_send_skb(struct sk_buff *skb, struct flowi6 *fl6)
1033{
1034        struct sock *sk = skb->sk;
1035        struct udphdr *uh;
1036        int err = 0;
1037        int is_udplite = IS_UDPLITE(sk);
1038        __wsum csum = 0;
1039        int offset = skb_transport_offset(skb);
1040        int len = skb->len - offset;
1041
1042        /*
1043         * Create a UDP header
1044         */
1045        uh = udp_hdr(skb);
1046        uh->source = fl6->fl6_sport;
1047        uh->dest = fl6->fl6_dport;
1048        uh->len = htons(len);
1049        uh->check = 0;
1050
1051        if (is_udplite)
1052                csum = udplite_csum(skb);
1053        else if (udp_sk(sk)->no_check6_tx) {   /* UDP csum disabled */
1054                skb->ip_summed = CHECKSUM_NONE;
1055                goto send;
1056        } else if (skb->ip_summed == CHECKSUM_PARTIAL) { /* UDP hardware csum */
1057                udp6_hwcsum_outgoing(sk, skb, &fl6->saddr, &fl6->daddr, len);
1058                goto send;
1059        } else
1060                csum = udp_csum(skb);
1061
1062        /* add protocol-dependent pseudo-header */
1063        uh->check = csum_ipv6_magic(&fl6->saddr, &fl6->daddr,
1064                                    len, fl6->flowi6_proto, csum);
1065        if (uh->check == 0)
1066                uh->check = CSUM_MANGLED_0;
1067
1068send:
1069        err = ip6_send_skb(skb);
1070        if (err) {
1071                if (err == -ENOBUFS && !inet6_sk(sk)->recverr) {
1072                        UDP6_INC_STATS(sock_net(sk),
1073                                       UDP_MIB_SNDBUFERRORS, is_udplite);
1074                        err = 0;
1075                }
1076        } else {
1077                UDP6_INC_STATS(sock_net(sk),
1078                               UDP_MIB_OUTDATAGRAMS, is_udplite);
1079        }
1080        return err;
1081}
1082
1083static int udp_v6_push_pending_frames(struct sock *sk)
1084{
1085        struct sk_buff *skb;
1086        struct udp_sock  *up = udp_sk(sk);
1087        struct flowi6 fl6;
1088        int err = 0;
1089
1090        if (up->pending == AF_INET)
1091                return udp_push_pending_frames(sk);
1092
1093        /* ip6_finish_skb will release the cork, so make a copy of
1094         * fl6 here.
1095         */
1096        fl6 = inet_sk(sk)->cork.fl.u.ip6;
1097
1098        skb = ip6_finish_skb(sk);
1099        if (!skb)
1100                goto out;
1101
1102        err = udp_v6_send_skb(skb, &fl6);
1103
1104out:
1105        up->len = 0;
1106        up->pending = 0;
1107        return err;
1108}
1109
1110int udpv6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
1111{
1112        struct ipv6_txoptions opt_space;
1113        struct udp_sock *up = udp_sk(sk);
1114        struct inet_sock *inet = inet_sk(sk);
1115        struct ipv6_pinfo *np = inet6_sk(sk);
1116        DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name);
1117        struct in6_addr *daddr, *final_p, final;
1118        struct ipv6_txoptions *opt = NULL;
1119        struct ipv6_txoptions *opt_to_free = NULL;
1120        struct ip6_flowlabel *flowlabel = NULL;
1121        struct flowi6 fl6;
1122        struct dst_entry *dst;
1123        struct ipcm6_cookie ipc6;
1124        int addr_len = msg->msg_namelen;
1125        int ulen = len;
1126        int corkreq = up->corkflag || msg->msg_flags&MSG_MORE;
1127        int err;
1128        int connected = 0;
1129        int is_udplite = IS_UDPLITE(sk);
1130        int (*getfrag)(void *, char *, int, int, int, struct sk_buff *);
1131        struct sockcm_cookie sockc;
1132
1133        ipc6.hlimit = -1;
1134        ipc6.tclass = -1;
1135        ipc6.dontfrag = -1;
1136        sockc.tsflags = sk->sk_tsflags;
1137
1138        /* destination address check */
1139        if (sin6) {
1140                if (addr_len < offsetof(struct sockaddr, sa_data))
1141                        return -EINVAL;
1142
1143                switch (sin6->sin6_family) {
1144                case AF_INET6:
1145                        if (addr_len < SIN6_LEN_RFC2133)
1146                                return -EINVAL;
1147                        daddr = &sin6->sin6_addr;
1148                        if (ipv6_addr_any(daddr) &&
1149                            ipv6_addr_v4mapped(&np->saddr))
1150                                ipv6_addr_set_v4mapped(htonl(INADDR_LOOPBACK),
1151                                                       daddr);
1152                        break;
1153                case AF_INET:
1154                        goto do_udp_sendmsg;
1155                case AF_UNSPEC:
1156                        msg->msg_name = sin6 = NULL;
1157                        msg->msg_namelen = addr_len = 0;
1158                        daddr = NULL;
1159                        break;
1160                default:
1161                        return -EINVAL;
1162                }
1163        } else if (!up->pending) {
1164                if (sk->sk_state != TCP_ESTABLISHED)
1165                        return -EDESTADDRREQ;
1166                daddr = &sk->sk_v6_daddr;
1167        } else
1168                daddr = NULL;
1169
1170        if (daddr) {
1171                if (ipv6_addr_v4mapped(daddr)) {
1172                        struct sockaddr_in sin;
1173                        sin.sin_family = AF_INET;
1174                        sin.sin_port = sin6 ? sin6->sin6_port : inet->inet_dport;
1175                        sin.sin_addr.s_addr = daddr->s6_addr32[3];
1176                        msg->msg_name = &sin;
1177                        msg->msg_namelen = sizeof(sin);
1178do_udp_sendmsg:
1179                        if (__ipv6_only_sock(sk))
1180                                return -ENETUNREACH;
1181                        return udp_sendmsg(sk, msg, len);
1182                }
1183        }
1184
1185        if (up->pending == AF_INET)
1186                return udp_sendmsg(sk, msg, len);
1187
1188        /* Rough check on arithmetic overflow,
1189           better check is made in ip6_append_data().
1190           */
1191        if (len > INT_MAX - sizeof(struct udphdr))
1192                return -EMSGSIZE;
1193
1194        getfrag  =  is_udplite ?  udplite_getfrag : ip_generic_getfrag;
1195        if (up->pending) {
1196                /*
1197                 * There are pending frames.
1198                 * The socket lock must be held while it's corked.
1199                 */
1200                lock_sock(sk);
1201                if (likely(up->pending)) {
1202                        if (unlikely(up->pending != AF_INET6)) {
1203                                release_sock(sk);
1204                                return -EAFNOSUPPORT;
1205                        }
1206                        dst = NULL;
1207                        goto do_append_data;
1208                }
1209                release_sock(sk);
1210        }
1211        ulen += sizeof(struct udphdr);
1212
1213        memset(&fl6, 0, sizeof(fl6));
1214
1215        if (sin6) {
1216                if (sin6->sin6_port == 0)
1217                        return -EINVAL;
1218
1219                fl6.fl6_dport = sin6->sin6_port;
1220                daddr = &sin6->sin6_addr;
1221
1222                if (np->sndflow) {
1223                        fl6.flowlabel = sin6->sin6_flowinfo&IPV6_FLOWINFO_MASK;
1224                        if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) {
1225                                flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
1226                                if (!flowlabel)
1227                                        return -EINVAL;
1228                        }
1229                }
1230
1231                /*
1232                 * Otherwise it will be difficult to maintain
1233                 * sk->sk_dst_cache.
1234                 */
1235                if (sk->sk_state == TCP_ESTABLISHED &&
1236                    ipv6_addr_equal(daddr, &sk->sk_v6_daddr))
1237                        daddr = &sk->sk_v6_daddr;
1238
1239                if (addr_len >= sizeof(struct sockaddr_in6) &&
1240                    sin6->sin6_scope_id &&
1241                    __ipv6_addr_needs_scope_id(__ipv6_addr_type(daddr)))
1242                        fl6.flowi6_oif = sin6->sin6_scope_id;
1243        } else {
1244                if (sk->sk_state != TCP_ESTABLISHED)
1245                        return -EDESTADDRREQ;
1246
1247                fl6.fl6_dport = inet->inet_dport;
1248                daddr = &sk->sk_v6_daddr;
1249                fl6.flowlabel = np->flow_label;
1250                connected = 1;
1251        }
1252
1253        if (!fl6.flowi6_oif)
1254                fl6.flowi6_oif = sk->sk_bound_dev_if;
1255
1256        if (!fl6.flowi6_oif)
1257                fl6.flowi6_oif = np->sticky_pktinfo.ipi6_ifindex;
1258
1259        fl6.flowi6_mark = sk->sk_mark;
1260        fl6.flowi6_uid = sk->sk_uid;
1261
1262        if (msg->msg_controllen) {
1263                opt = &opt_space;
1264                memset(opt, 0, sizeof(struct ipv6_txoptions));
1265                opt->tot_len = sizeof(*opt);
1266                ipc6.opt = opt;
1267
1268                err = ip6_datagram_send_ctl(sock_net(sk), sk, msg, &fl6, &ipc6, &sockc);
1269                if (err < 0) {
1270                        fl6_sock_release(flowlabel);
1271                        return err;
1272                }
1273                if ((fl6.flowlabel&IPV6_FLOWLABEL_MASK) && !flowlabel) {
1274                        flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
1275                        if (!flowlabel)
1276                                return -EINVAL;
1277                }
1278                if (!(opt->opt_nflen|opt->opt_flen))
1279                        opt = NULL;
1280                connected = 0;
1281        }
1282        if (!opt) {
1283                opt = txopt_get(np);
1284                opt_to_free = opt;
1285        }
1286        if (flowlabel)
1287                opt = fl6_merge_options(&opt_space, flowlabel, opt);
1288        opt = ipv6_fixup_options(&opt_space, opt);
1289        ipc6.opt = opt;
1290
1291        fl6.flowi6_proto = sk->sk_protocol;
1292        if (!ipv6_addr_any(daddr))
1293                fl6.daddr = *daddr;
1294        else
1295                fl6.daddr.s6_addr[15] = 0x1; /* :: means loopback (BSD'ism) */
1296        if (ipv6_addr_any(&fl6.saddr) && !ipv6_addr_any(&np->saddr))
1297                fl6.saddr = np->saddr;
1298        fl6.fl6_sport = inet->inet_sport;
1299
1300        final_p = fl6_update_dst(&fl6, opt, &final);
1301        if (final_p)
1302                connected = 0;
1303
1304        if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr)) {
1305                fl6.flowi6_oif = np->mcast_oif;
1306                connected = 0;
1307        } else if (!fl6.flowi6_oif)
1308                fl6.flowi6_oif = np->ucast_oif;
1309
1310        security_sk_classify_flow(sk, flowi6_to_flowi(&fl6));
1311
1312        if (ipc6.tclass < 0)
1313                ipc6.tclass = np->tclass;
1314
1315        fl6.flowlabel = ip6_make_flowinfo(ipc6.tclass, fl6.flowlabel);
1316
1317        dst = ip6_sk_dst_lookup_flow(sk, &fl6, final_p);
1318        if (IS_ERR(dst)) {
1319                err = PTR_ERR(dst);
1320                dst = NULL;
1321                goto out;
1322        }
1323
1324        if (ipc6.hlimit < 0)
1325                ipc6.hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst);
1326
1327        if (msg->msg_flags&MSG_CONFIRM)
1328                goto do_confirm;
1329back_from_confirm:
1330
1331        /* Lockless fast path for the non-corking case */
1332        if (!corkreq) {
1333                struct sk_buff *skb;
1334
1335                skb = ip6_make_skb(sk, getfrag, msg, ulen,
1336                                   sizeof(struct udphdr), &ipc6,
1337                                   &fl6, (struct rt6_info *)dst,
1338                                   msg->msg_flags, &sockc);
1339                err = PTR_ERR(skb);
1340                if (!IS_ERR_OR_NULL(skb))
1341                        err = udp_v6_send_skb(skb, &fl6);
1342                goto release_dst;
1343        }
1344
1345        lock_sock(sk);
1346        if (unlikely(up->pending)) {
1347                /* The socket is already corked while preparing it. */
1348                /* ... which is an evident application bug. --ANK */
1349                release_sock(sk);
1350
1351                net_dbg_ratelimited("udp cork app bug 2\n");
1352                err = -EINVAL;
1353                goto out;
1354        }
1355
1356        up->pending = AF_INET6;
1357
1358do_append_data:
1359        if (ipc6.dontfrag < 0)
1360                ipc6.dontfrag = np->dontfrag;
1361        up->len += ulen;
1362        err = ip6_append_data(sk, getfrag, msg, ulen, sizeof(struct udphdr),
1363                              &ipc6, &fl6, (struct rt6_info *)dst,
1364                              corkreq ? msg->msg_flags|MSG_MORE : msg->msg_flags, &sockc);
1365        if (err)
1366                udp_v6_flush_pending_frames(sk);
1367        else if (!corkreq)
1368                err = udp_v6_push_pending_frames(sk);
1369        else if (unlikely(skb_queue_empty(&sk->sk_write_queue)))
1370                up->pending = 0;
1371
1372        if (err > 0)
1373                err = np->recverr ? net_xmit_errno(err) : 0;
1374        release_sock(sk);
1375
1376release_dst:
1377        if (dst) {
1378                if (connected) {
1379                        ip6_dst_store(sk, dst,
1380                                      ipv6_addr_equal(&fl6.daddr, &sk->sk_v6_daddr) ?
1381                                      &sk->sk_v6_daddr : NULL,
1382#ifdef CONFIG_IPV6_SUBTREES
1383                                      ipv6_addr_equal(&fl6.saddr, &np->saddr) ?
1384                                      &np->saddr :
1385#endif
1386                                      NULL);
1387                } else {
1388                        dst_release(dst);
1389                }
1390                dst = NULL;
1391        }
1392
1393out:
1394        dst_release(dst);
1395        fl6_sock_release(flowlabel);
1396        txopt_put(opt_to_free);
1397        if (!err)
1398                return len;
1399        /*
1400         * ENOBUFS = no kernel mem, SOCK_NOSPACE = no sndbuf space.  Reporting
1401         * ENOBUFS might not be good (it's not tunable per se), but otherwise
1402         * we don't have a good statistic (IpOutDiscards but it can be too many
1403         * things).  We could add another new stat but at least for now that
1404         * seems like overkill.
1405         */
1406        if (err == -ENOBUFS || test_bit(SOCK_NOSPACE, &sk->sk_socket->flags)) {
1407                UDP6_INC_STATS(sock_net(sk),
1408                               UDP_MIB_SNDBUFERRORS, is_udplite);
1409        }
1410        return err;
1411
1412do_confirm:
1413        if (msg->msg_flags & MSG_PROBE)
1414                dst_confirm_neigh(dst, &fl6.daddr);
1415        if (!(msg->msg_flags&MSG_PROBE) || len)
1416                goto back_from_confirm;
1417        err = 0;
1418        goto out;
1419}
1420
1421void udpv6_destroy_sock(struct sock *sk)
1422{
1423        struct udp_sock *up = udp_sk(sk);
1424        lock_sock(sk);
1425        udp_v6_flush_pending_frames(sk);
1426        release_sock(sk);
1427
1428        if (static_key_false(&udpv6_encap_needed) && up->encap_type) {
1429                void (*encap_destroy)(struct sock *sk);
1430                encap_destroy = ACCESS_ONCE(up->encap_destroy);
1431                if (encap_destroy)
1432                        encap_destroy(sk);
1433        }
1434
1435        inet6_destroy_sock(sk);
1436}
1437
1438/*
1439 *      Socket option code for UDP
1440 */
1441int udpv6_setsockopt(struct sock *sk, int level, int optname,
1442                     char __user *optval, unsigned int optlen)
1443{
1444        if (level == SOL_UDP  ||  level == SOL_UDPLITE)
1445                return udp_lib_setsockopt(sk, level, optname, optval, optlen,
1446                                          udp_v6_push_pending_frames);
1447        return ipv6_setsockopt(sk, level, optname, optval, optlen);
1448}
1449
1450#ifdef CONFIG_COMPAT
1451int compat_udpv6_setsockopt(struct sock *sk, int level, int optname,
1452                            char __user *optval, unsigned int optlen)
1453{
1454        if (level == SOL_UDP  ||  level == SOL_UDPLITE)
1455                return udp_lib_setsockopt(sk, level, optname, optval, optlen,
1456                                          udp_v6_push_pending_frames);
1457        return compat_ipv6_setsockopt(sk, level, optname, optval, optlen);
1458}
1459#endif
1460
1461int udpv6_getsockopt(struct sock *sk, int level, int optname,
1462                     char __user *optval, int __user *optlen)
1463{
1464        if (level == SOL_UDP  ||  level == SOL_UDPLITE)
1465                return udp_lib_getsockopt(sk, level, optname, optval, optlen);
1466        return ipv6_getsockopt(sk, level, optname, optval, optlen);
1467}
1468
1469#ifdef CONFIG_COMPAT
1470int compat_udpv6_getsockopt(struct sock *sk, int level, int optname,
1471                            char __user *optval, int __user *optlen)
1472{
1473        if (level == SOL_UDP  ||  level == SOL_UDPLITE)
1474                return udp_lib_getsockopt(sk, level, optname, optval, optlen);
1475        return compat_ipv6_getsockopt(sk, level, optname, optval, optlen);
1476}
1477#endif
1478
1479static struct inet6_protocol udpv6_protocol = {
1480        .early_demux    =       udp_v6_early_demux,
1481        .early_demux_handler =  udp_v6_early_demux,
1482        .handler        =       udpv6_rcv,
1483        .err_handler    =       udpv6_err,
1484        .flags          =       INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
1485};
1486
1487/* ------------------------------------------------------------------------ */
1488#ifdef CONFIG_PROC_FS
1489int udp6_seq_show(struct seq_file *seq, void *v)
1490{
1491        if (v == SEQ_START_TOKEN) {
1492                seq_puts(seq, IPV6_SEQ_DGRAM_HEADER);
1493        } else {
1494                int bucket = ((struct udp_iter_state *)seq->private)->bucket;
1495                struct inet_sock *inet = inet_sk(v);
1496                __u16 srcp = ntohs(inet->inet_sport);
1497                __u16 destp = ntohs(inet->inet_dport);
1498                ip6_dgram_sock_seq_show(seq, v, srcp, destp, bucket);
1499        }
1500        return 0;
1501}
1502
1503static const struct file_operations udp6_afinfo_seq_fops = {
1504        .owner    = THIS_MODULE,
1505        .open     = udp_seq_open,
1506        .read     = seq_read,
1507        .llseek   = seq_lseek,
1508        .release  = seq_release_net
1509};
1510
1511static struct udp_seq_afinfo udp6_seq_afinfo = {
1512        .name           = "udp6",
1513        .family         = AF_INET6,
1514        .udp_table      = &udp_table,
1515        .seq_fops       = &udp6_afinfo_seq_fops,
1516        .seq_ops        = {
1517                .show           = udp6_seq_show,
1518        },
1519};
1520
1521int __net_init udp6_proc_init(struct net *net)
1522{
1523        return udp_proc_register(net, &udp6_seq_afinfo);
1524}
1525
1526void udp6_proc_exit(struct net *net)
1527{
1528        udp_proc_unregister(net, &udp6_seq_afinfo);
1529}
1530#endif /* CONFIG_PROC_FS */
1531
1532/* ------------------------------------------------------------------------ */
1533
1534struct proto udpv6_prot = {
1535        .name              = "UDPv6",
1536        .owner             = THIS_MODULE,
1537        .close             = udp_lib_close,
1538        .connect           = ip6_datagram_connect,
1539        .disconnect        = udp_disconnect,
1540        .ioctl             = udp_ioctl,
1541        .init              = udp_init_sock,
1542        .destroy           = udpv6_destroy_sock,
1543        .setsockopt        = udpv6_setsockopt,
1544        .getsockopt        = udpv6_getsockopt,
1545        .sendmsg           = udpv6_sendmsg,
1546        .recvmsg           = udpv6_recvmsg,
1547        .release_cb        = ip6_datagram_release_cb,
1548        .hash              = udp_lib_hash,
1549        .unhash            = udp_lib_unhash,
1550        .rehash            = udp_v6_rehash,
1551        .get_port          = udp_v6_get_port,
1552        .memory_allocated  = &udp_memory_allocated,
1553        .sysctl_mem        = sysctl_udp_mem,
1554        .sysctl_wmem       = &sysctl_udp_wmem_min,
1555        .sysctl_rmem       = &sysctl_udp_rmem_min,
1556        .obj_size          = sizeof(struct udp6_sock),
1557        .h.udp_table       = &udp_table,
1558#ifdef CONFIG_COMPAT
1559        .compat_setsockopt = compat_udpv6_setsockopt,
1560        .compat_getsockopt = compat_udpv6_getsockopt,
1561#endif
1562        .diag_destroy      = udp_abort,
1563};
1564
1565static struct inet_protosw udpv6_protosw = {
1566        .type =      SOCK_DGRAM,
1567        .protocol =  IPPROTO_UDP,
1568        .prot =      &udpv6_prot,
1569        .ops =       &inet6_dgram_ops,
1570        .flags =     INET_PROTOSW_PERMANENT,
1571};
1572
1573int __init udpv6_init(void)
1574{
1575        int ret;
1576
1577        ret = inet6_add_protocol(&udpv6_protocol, IPPROTO_UDP);
1578        if (ret)
1579                goto out;
1580
1581        ret = inet6_register_protosw(&udpv6_protosw);
1582        if (ret)
1583                goto out_udpv6_protocol;
1584out:
1585        return ret;
1586
1587out_udpv6_protocol:
1588        inet6_del_protocol(&udpv6_protocol, IPPROTO_UDP);
1589        goto out;
1590}
1591
1592void udpv6_exit(void)
1593{
1594        inet6_unregister_protosw(&udpv6_protosw);
1595        inet6_del_protocol(&udpv6_protocol, IPPROTO_UDP);
1596}
1597