net/ipv6/udp.c

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This source file includes following definitions.
udp6_ehashfn
udp_v6_get_port
udp_v6_rehash
compute_score
udp6_lib_lookup2
__udp6_lib_lookup
__udp6_lib_lookup_skb
udp6_lib_lookup_skb
udp6_lib_lookup
udp6_skb_len
udpv6_recvmsg
udpv6_encap_enable
__udp6_lib_err_encap_no_sk
__udp6_lib_err_encap
__udp6_lib_err
__udpv6_queue_rcv_skb
udpv6_err
udpv6_queue_rcv_one_skb
udpv6_queue_rcv_skb
__udp_v6_is_mcast_sock
udp6_csum_zero_error
__udp6_lib_mcast_deliver
udp6_sk_rx_dst_set
udp6_unicast_rcv_skb
__udp6_lib_rcv
__udp6_lib_demux_lookup
udp_v6_early_demux
udpv6_rcv
udp_v6_flush_pending_frames
udpv6_pre_connect
udp6_hwcsum_outgoing
udp_v6_send_skb
udp_v6_push_pending_frames
udpv6_sendmsg
udpv6_destroy_sock
udpv6_setsockopt
compat_udpv6_setsockopt
udpv6_getsockopt
compat_udpv6_getsockopt
udp6_seq_show
udp6_proc_init
udp6_proc_exit
udpv6_init
udpv6_exit
   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *      UDP over IPv6
   4  *      Linux INET6 implementation
   5  *
   6  *      Authors:
   7  *      Pedro Roque             <roque@di.fc.ul.pt>
   8  *
   9  *      Based on linux/ipv4/udp.c
  10  *
  11  *      Fixes:
  12  *      Hideaki YOSHIFUJI       :       sin6_scope_id support
  13  *      YOSHIFUJI Hideaki @USAGI and:   Support IPV6_V6ONLY socket option, which
  14  *      Alexey Kuznetsov                allow both IPv4 and IPv6 sockets to bind
  15  *                                      a single port at the same time.
  16  *      Kazunori MIYAZAWA @USAGI:       change process style to use ip6_append_data
  17  *      YOSHIFUJI Hideaki @USAGI:       convert /proc/net/udp6 to seq_file.
  18  */
  19 
  20 #include <linux/errno.h>
  21 #include <linux/types.h>
  22 #include <linux/socket.h>
  23 #include <linux/sockios.h>
  24 #include <linux/net.h>
  25 #include <linux/in6.h>
  26 #include <linux/netdevice.h>
  27 #include <linux/if_arp.h>
  28 #include <linux/ipv6.h>
  29 #include <linux/icmpv6.h>
  30 #include <linux/init.h>
  31 #include <linux/module.h>
  32 #include <linux/skbuff.h>
  33 #include <linux/slab.h>
  34 #include <linux/uaccess.h>
  35 #include <linux/indirect_call_wrapper.h>
  36 
  37 #include <net/addrconf.h>
  38 #include <net/ndisc.h>
  39 #include <net/protocol.h>
  40 #include <net/transp_v6.h>
  41 #include <net/ip6_route.h>
  42 #include <net/raw.h>
  43 #include <net/tcp_states.h>
  44 #include <net/ip6_checksum.h>
  45 #include <net/ip6_tunnel.h>
  46 #include <net/xfrm.h>
  47 #include <net/inet_hashtables.h>
  48 #include <net/inet6_hashtables.h>
  49 #include <net/busy_poll.h>
  50 #include <net/sock_reuseport.h>
  51 
  52 #include <linux/proc_fs.h>
  53 #include <linux/seq_file.h>
  54 #include <trace/events/skb.h>
  55 #include "udp_impl.h"
  56 
  57 static u32 udp6_ehashfn(const struct net *net,
  58                         const struct in6_addr *laddr,
  59                         const u16 lport,
  60                         const struct in6_addr *faddr,
  61                         const __be16 fport)
  62 {
  63         static u32 udp6_ehash_secret __read_mostly;
  64         static u32 udp_ipv6_hash_secret __read_mostly;
  65 
  66         u32 lhash, fhash;
  67 
  68         net_get_random_once(&udp6_ehash_secret,
  69                             sizeof(udp6_ehash_secret));
  70         net_get_random_once(&udp_ipv6_hash_secret,
  71                             sizeof(udp_ipv6_hash_secret));
  72 
  73         lhash = (__force u32)laddr->s6_addr32[3];
  74         fhash = __ipv6_addr_jhash(faddr, udp_ipv6_hash_secret);
  75 
  76         return __inet6_ehashfn(lhash, lport, fhash, fport,
  77                                udp_ipv6_hash_secret + net_hash_mix(net));
  78 }
  79 
  80 int udp_v6_get_port(struct sock *sk, unsigned short snum)
  81 {
  82         unsigned int hash2_nulladdr =
  83                 ipv6_portaddr_hash(sock_net(sk), &in6addr_any, snum);
  84         unsigned int hash2_partial =
  85                 ipv6_portaddr_hash(sock_net(sk), &sk->sk_v6_rcv_saddr, 0);
  86 
  87         /* precompute partial secondary hash */
  88         udp_sk(sk)->udp_portaddr_hash = hash2_partial;
  89         return udp_lib_get_port(sk, snum, hash2_nulladdr);
  90 }
  91 
  92 void udp_v6_rehash(struct sock *sk)
  93 {
  94         u16 new_hash = ipv6_portaddr_hash(sock_net(sk),
  95                                           &sk->sk_v6_rcv_saddr,
  96                                           inet_sk(sk)->inet_num);
  97 
  98         udp_lib_rehash(sk, new_hash);
  99 }
 100 
 101 static int compute_score(struct sock *sk, struct net *net,
 102                          const struct in6_addr *saddr, __be16 sport,
 103                          const struct in6_addr *daddr, unsigned short hnum,
 104                          int dif, int sdif)
 105 {
 106         int score;
 107         struct inet_sock *inet;
 108         bool dev_match;
 109 
 110         if (!net_eq(sock_net(sk), net) ||
 111             udp_sk(sk)->udp_port_hash != hnum ||
 112             sk->sk_family != PF_INET6)
 113                 return -1;
 114 
 115         if (!ipv6_addr_equal(&sk->sk_v6_rcv_saddr, daddr))
 116                 return -1;
 117 
 118         score = 0;
 119         inet = inet_sk(sk);
 120 
 121         if (inet->inet_dport) {
 122                 if (inet->inet_dport != sport)
 123                         return -1;
 124                 score++;
 125         }
 126 
 127         if (!ipv6_addr_any(&sk->sk_v6_daddr)) {
 128                 if (!ipv6_addr_equal(&sk->sk_v6_daddr, saddr))
 129                         return -1;
 130                 score++;
 131         }
 132 
 133         dev_match = udp_sk_bound_dev_eq(net, sk->sk_bound_dev_if, dif, sdif);
 134         if (!dev_match)
 135                 return -1;
 136         score++;
 137 
 138         if (READ_ONCE(sk->sk_incoming_cpu) == raw_smp_processor_id())
 139                 score++;
 140 
 141         return score;
 142 }
 143 
 144 /* called with rcu_read_lock() */
 145 static struct sock *udp6_lib_lookup2(struct net *net,
 146                 const struct in6_addr *saddr, __be16 sport,
 147                 const struct in6_addr *daddr, unsigned int hnum,
 148                 int dif, int sdif, struct udp_hslot *hslot2,
 149                 struct sk_buff *skb)
 150 {
 151         struct sock *sk, *result;
 152         int score, badness;
 153         u32 hash = 0;
 154 
 155         result = NULL;
 156         badness = -1;
 157         udp_portaddr_for_each_entry_rcu(sk, &hslot2->head) {
 158                 score = compute_score(sk, net, saddr, sport,
 159                                       daddr, hnum, dif, sdif);
 160                 if (score > badness) {
 161                         if (sk->sk_reuseport &&
 162                             sk->sk_state != TCP_ESTABLISHED) {
 163                                 hash = udp6_ehashfn(net, daddr, hnum,
 164                                                     saddr, sport);
 165 
 166                                 result = reuseport_select_sock(sk, hash, skb,
 167                                                         sizeof(struct udphdr));
 168                                 if (result && !reuseport_has_conns(sk, false))
 169                                         return result;
 170                         }
 171                         result = sk;
 172                         badness = score;
 173                 }
 174         }
 175         return result;
 176 }
 177 
 178 /* rcu_read_lock() must be held */
 179 struct sock *__udp6_lib_lookup(struct net *net,
 180                                const struct in6_addr *saddr, __be16 sport,
 181                                const struct in6_addr *daddr, __be16 dport,
 182                                int dif, int sdif, struct udp_table *udptable,
 183                                struct sk_buff *skb)
 184 {
 185         unsigned short hnum = ntohs(dport);
 186         unsigned int hash2, slot2;
 187         struct udp_hslot *hslot2;
 188         struct sock *result;
 189 
 190         hash2 = ipv6_portaddr_hash(net, daddr, hnum);
 191         slot2 = hash2 & udptable->mask;
 192         hslot2 = &udptable->hash2[slot2];
 193 
 194         result = udp6_lib_lookup2(net, saddr, sport,
 195                                   daddr, hnum, dif, sdif,
 196                                   hslot2, skb);
 197         if (!result) {
 198                 hash2 = ipv6_portaddr_hash(net, &in6addr_any, hnum);
 199                 slot2 = hash2 & udptable->mask;
 200 
 201                 hslot2 = &udptable->hash2[slot2];
 202 
 203                 result = udp6_lib_lookup2(net, saddr, sport,
 204                                           &in6addr_any, hnum, dif, sdif,
 205                                           hslot2, skb);
 206         }
 207         if (IS_ERR(result))
 208                 return NULL;
 209         return result;
 210 }
 211 EXPORT_SYMBOL_GPL(__udp6_lib_lookup);
 212 
 213 static struct sock *__udp6_lib_lookup_skb(struct sk_buff *skb,
 214                                           __be16 sport, __be16 dport,
 215                                           struct udp_table *udptable)
 216 {
 217         const struct ipv6hdr *iph = ipv6_hdr(skb);
 218 
 219         return __udp6_lib_lookup(dev_net(skb->dev), &iph->saddr, sport,
 220                                  &iph->daddr, dport, inet6_iif(skb),
 221                                  inet6_sdif(skb), udptable, skb);
 222 }
 223 
 224 struct sock *udp6_lib_lookup_skb(struct sk_buff *skb,
 225                                  __be16 sport, __be16 dport)
 226 {
 227         const struct ipv6hdr *iph = ipv6_hdr(skb);
 228 
 229         return __udp6_lib_lookup(dev_net(skb->dev), &iph->saddr, sport,
 230                                  &iph->daddr, dport, inet6_iif(skb),
 231                                  inet6_sdif(skb), &udp_table, NULL);
 232 }
 233 EXPORT_SYMBOL_GPL(udp6_lib_lookup_skb);
 234 
 235 /* Must be called under rcu_read_lock().
 236  * Does increment socket refcount.
 237  */
 238 #if IS_ENABLED(CONFIG_NF_TPROXY_IPV6) || IS_ENABLED(CONFIG_NF_SOCKET_IPV6)
 239 struct sock *udp6_lib_lookup(struct net *net, const struct in6_addr *saddr, __be16 sport,
 240                              const struct in6_addr *daddr, __be16 dport, int dif)
 241 {
 242         struct sock *sk;
 243 
 244         sk =  __udp6_lib_lookup(net, saddr, sport, daddr, dport,
 245                                 dif, 0, &udp_table, NULL);
 246         if (sk && !refcount_inc_not_zero(&sk->sk_refcnt))
 247                 sk = NULL;
 248         return sk;
 249 }
 250 EXPORT_SYMBOL_GPL(udp6_lib_lookup);
 251 #endif
 252 
 253 /* do not use the scratch area len for jumbogram: their length execeeds the
 254  * scratch area space; note that the IP6CB flags is still in the first
 255  * cacheline, so checking for jumbograms is cheap
 256  */
 257 static int udp6_skb_len(struct sk_buff *skb)
 258 {
 259         return unlikely(inet6_is_jumbogram(skb)) ? skb->len : udp_skb_len(skb);
 260 }
 261 
 262 /*
 263  *      This should be easy, if there is something there we
 264  *      return it, otherwise we block.
 265  */
 266 
 267 int udpv6_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
 268                   int noblock, int flags, int *addr_len)
 269 {
 270         struct ipv6_pinfo *np = inet6_sk(sk);
 271         struct inet_sock *inet = inet_sk(sk);
 272         struct sk_buff *skb;
 273         unsigned int ulen, copied;
 274         int off, err, peeking = flags & MSG_PEEK;
 275         int is_udplite = IS_UDPLITE(sk);
 276         struct udp_mib __percpu *mib;
 277         bool checksum_valid = false;
 278         int is_udp4;
 279 
 280         if (flags & MSG_ERRQUEUE)
 281                 return ipv6_recv_error(sk, msg, len, addr_len);
 282 
 283         if (np->rxpmtu && np->rxopt.bits.rxpmtu)
 284                 return ipv6_recv_rxpmtu(sk, msg, len, addr_len);
 285 
 286 try_again:
 287         off = sk_peek_offset(sk, flags);
 288         skb = __skb_recv_udp(sk, flags, noblock, &off, &err);
 289         if (!skb)
 290                 return err;
 291 
 292         ulen = udp6_skb_len(skb);
 293         copied = len;
 294         if (copied > ulen - off)
 295                 copied = ulen - off;
 296         else if (copied < ulen)
 297                 msg->msg_flags |= MSG_TRUNC;
 298 
 299         is_udp4 = (skb->protocol == htons(ETH_P_IP));
 300         mib = __UDPX_MIB(sk, is_udp4);
 301 
 302         /*
 303          * If checksum is needed at all, try to do it while copying the
 304          * data.  If the data is truncated, or if we only want a partial
 305          * coverage checksum (UDP-Lite), do it before the copy.
 306          */
 307 
 308         if (copied < ulen || peeking ||
 309             (is_udplite && UDP_SKB_CB(skb)->partial_cov)) {
 310                 checksum_valid = udp_skb_csum_unnecessary(skb) ||
 311                                 !__udp_lib_checksum_complete(skb);
 312                 if (!checksum_valid)
 313                         goto csum_copy_err;
 314         }
 315 
 316         if (checksum_valid || udp_skb_csum_unnecessary(skb)) {
 317                 if (udp_skb_is_linear(skb))
 318                         err = copy_linear_skb(skb, copied, off, &msg->msg_iter);
 319                 else
 320                         err = skb_copy_datagram_msg(skb, off, msg, copied);
 321         } else {
 322                 err = skb_copy_and_csum_datagram_msg(skb, off, msg);
 323                 if (err == -EINVAL)
 324                         goto csum_copy_err;
 325         }
 326         if (unlikely(err)) {
 327                 if (!peeking) {
 328                         atomic_inc(&sk->sk_drops);
 329                         SNMP_INC_STATS(mib, UDP_MIB_INERRORS);
 330                 }
 331                 kfree_skb(skb);
 332                 return err;
 333         }
 334         if (!peeking)
 335                 SNMP_INC_STATS(mib, UDP_MIB_INDATAGRAMS);
 336 
 337         sock_recv_ts_and_drops(msg, sk, skb);
 338 
 339         /* Copy the address. */
 340         if (msg->msg_name) {
 341                 DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name);
 342                 sin6->sin6_family = AF_INET6;
 343                 sin6->sin6_port = udp_hdr(skb)->source;
 344                 sin6->sin6_flowinfo = 0;
 345 
 346                 if (is_udp4) {
 347                         ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr,
 348                                                &sin6->sin6_addr);
 349                         sin6->sin6_scope_id = 0;
 350                 } else {
 351                         sin6->sin6_addr = ipv6_hdr(skb)->saddr;
 352                         sin6->sin6_scope_id =
 353                                 ipv6_iface_scope_id(&sin6->sin6_addr,
 354                                                     inet6_iif(skb));
 355                 }
 356                 *addr_len = sizeof(*sin6);
 357 
 358                 if (cgroup_bpf_enabled)
 359                         BPF_CGROUP_RUN_PROG_UDP6_RECVMSG_LOCK(sk,
 360                                                 (struct sockaddr *)sin6);
 361         }
 362 
 363         if (udp_sk(sk)->gro_enabled)
 364                 udp_cmsg_recv(msg, sk, skb);
 365 
 366         if (np->rxopt.all)
 367                 ip6_datagram_recv_common_ctl(sk, msg, skb);
 368 
 369         if (is_udp4) {
 370                 if (inet->cmsg_flags)
 371                         ip_cmsg_recv_offset(msg, sk, skb,
 372                                             sizeof(struct udphdr), off);
 373         } else {
 374                 if (np->rxopt.all)
 375                         ip6_datagram_recv_specific_ctl(sk, msg, skb);
 376         }
 377 
 378         err = copied;
 379         if (flags & MSG_TRUNC)
 380                 err = ulen;
 381 
 382         skb_consume_udp(sk, skb, peeking ? -err : err);
 383         return err;
 384 
 385 csum_copy_err:
 386         if (!__sk_queue_drop_skb(sk, &udp_sk(sk)->reader_queue, skb, flags,
 387                                  udp_skb_destructor)) {
 388                 SNMP_INC_STATS(mib, UDP_MIB_CSUMERRORS);
 389                 SNMP_INC_STATS(mib, UDP_MIB_INERRORS);
 390         }
 391         kfree_skb(skb);
 392 
 393         /* starting over for a new packet, but check if we need to yield */
 394         cond_resched();
 395         msg->msg_flags &= ~MSG_TRUNC;
 396         goto try_again;
 397 }
 398 
 399 DEFINE_STATIC_KEY_FALSE(udpv6_encap_needed_key);
 400 void udpv6_encap_enable(void)
 401 {
 402         static_branch_inc(&udpv6_encap_needed_key);
 403 }
 404 EXPORT_SYMBOL(udpv6_encap_enable);
 405 
 406 /* Handler for tunnels with arbitrary destination ports: no socket lookup, go
 407  * through error handlers in encapsulations looking for a match.
 408  */
 409 static int __udp6_lib_err_encap_no_sk(struct sk_buff *skb,
 410                                       struct inet6_skb_parm *opt,
 411                                       u8 type, u8 code, int offset, __be32 info)
 412 {
 413         int i;
 414 
 415         for (i = 0; i < MAX_IPTUN_ENCAP_OPS; i++) {
 416                 int (*handler)(struct sk_buff *skb, struct inet6_skb_parm *opt,
 417                                u8 type, u8 code, int offset, __be32 info);
 418                 const struct ip6_tnl_encap_ops *encap;
 419 
 420                 encap = rcu_dereference(ip6tun_encaps[i]);
 421                 if (!encap)
 422                         continue;
 423                 handler = encap->err_handler;
 424                 if (handler && !handler(skb, opt, type, code, offset, info))
 425                         return 0;
 426         }
 427 
 428         return -ENOENT;
 429 }
 430 
 431 /* Try to match ICMP errors to UDP tunnels by looking up a socket without
 432  * reversing source and destination port: this will match tunnels that force the
 433  * same destination port on both endpoints (e.g. VXLAN, GENEVE). Note that
 434  * lwtunnels might actually break this assumption by being configured with
 435  * different destination ports on endpoints, in this case we won't be able to
 436  * trace ICMP messages back to them.
 437  *
 438  * If this doesn't match any socket, probe tunnels with arbitrary destination
 439  * ports (e.g. FoU, GUE): there, the receiving socket is useless, as the port
 440  * we've sent packets to won't necessarily match the local destination port.
 441  *
 442  * Then ask the tunnel implementation to match the error against a valid
 443  * association.
 444  *
 445  * Return an error if we can't find a match, the socket if we need further
 446  * processing, zero otherwise.
 447  */
 448 static struct sock *__udp6_lib_err_encap(struct net *net,
 449                                          const struct ipv6hdr *hdr, int offset,
 450                                          struct udphdr *uh,
 451                                          struct udp_table *udptable,
 452                                          struct sk_buff *skb,
 453                                          struct inet6_skb_parm *opt,
 454                                          u8 type, u8 code, __be32 info)
 455 {
 456         int network_offset, transport_offset;
 457         struct sock *sk;
 458 
 459         network_offset = skb_network_offset(skb);
 460         transport_offset = skb_transport_offset(skb);
 461 
 462         /* Network header needs to point to the outer IPv6 header inside ICMP */
 463         skb_reset_network_header(skb);
 464 
 465         /* Transport header needs to point to the UDP header */
 466         skb_set_transport_header(skb, offset);
 467 
 468         sk = __udp6_lib_lookup(net, &hdr->daddr, uh->source,
 469                                &hdr->saddr, uh->dest,
 470                                inet6_iif(skb), 0, udptable, skb);
 471         if (sk) {
 472                 int (*lookup)(struct sock *sk, struct sk_buff *skb);
 473                 struct udp_sock *up = udp_sk(sk);
 474 
 475                 lookup = READ_ONCE(up->encap_err_lookup);
 476                 if (!lookup || lookup(sk, skb))
 477                         sk = NULL;
 478         }
 479 
 480         if (!sk) {
 481                 sk = ERR_PTR(__udp6_lib_err_encap_no_sk(skb, opt, type, code,
 482                                                         offset, info));
 483         }
 484 
 485         skb_set_transport_header(skb, transport_offset);
 486         skb_set_network_header(skb, network_offset);
 487 
 488         return sk;
 489 }
 490 
 491 int __udp6_lib_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 492                    u8 type, u8 code, int offset, __be32 info,
 493                    struct udp_table *udptable)
 494 {
 495         struct ipv6_pinfo *np;
 496         const struct ipv6hdr *hdr = (const struct ipv6hdr *)skb->data;
 497         const struct in6_addr *saddr = &hdr->saddr;
 498         const struct in6_addr *daddr = &hdr->daddr;
 499         struct udphdr *uh = (struct udphdr *)(skb->data+offset);
 500         bool tunnel = false;
 501         struct sock *sk;
 502         int harderr;
 503         int err;
 504         struct net *net = dev_net(skb->dev);
 505 
 506         sk = __udp6_lib_lookup(net, daddr, uh->dest, saddr, uh->source,
 507                                inet6_iif(skb), inet6_sdif(skb), udptable, NULL);
 508         if (!sk) {
 509                 /* No socket for error: try tunnels before discarding */
 510                 sk = ERR_PTR(-ENOENT);
 511                 if (static_branch_unlikely(&udpv6_encap_needed_key)) {
 512                         sk = __udp6_lib_err_encap(net, hdr, offset, uh,
 513                                                   udptable, skb,
 514                                                   opt, type, code, info);
 515                         if (!sk)
 516                                 return 0;
 517                 }
 518 
 519                 if (IS_ERR(sk)) {
 520                         __ICMP6_INC_STATS(net, __in6_dev_get(skb->dev),
 521                                           ICMP6_MIB_INERRORS);
 522                         return PTR_ERR(sk);
 523                 }
 524 
 525                 tunnel = true;
 526         }
 527 
 528         harderr = icmpv6_err_convert(type, code, &err);
 529         np = inet6_sk(sk);
 530 
 531         if (type == ICMPV6_PKT_TOOBIG) {
 532                 if (!ip6_sk_accept_pmtu(sk))
 533                         goto out;
 534                 ip6_sk_update_pmtu(skb, sk, info);
 535                 if (np->pmtudisc != IPV6_PMTUDISC_DONT)
 536                         harderr = 1;
 537         }
 538         if (type == NDISC_REDIRECT) {
 539                 if (tunnel) {
 540                         ip6_redirect(skb, sock_net(sk), inet6_iif(skb),
 541                                      sk->sk_mark, sk->sk_uid);
 542                 } else {
 543                         ip6_sk_redirect(skb, sk);
 544                 }
 545                 goto out;
 546         }
 547 
 548         /* Tunnels don't have an application socket: don't pass errors back */
 549         if (tunnel)
 550                 goto out;
 551 
 552         if (!np->recverr) {
 553                 if (!harderr || sk->sk_state != TCP_ESTABLISHED)
 554                         goto out;
 555         } else {
 556                 ipv6_icmp_error(sk, skb, err, uh->dest, ntohl(info), (u8 *)(uh+1));
 557         }
 558 
 559         sk->sk_err = err;
 560         sk->sk_error_report(sk);
 561 out:
 562         return 0;
 563 }
 564 
 565 static int __udpv6_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
 566 {
 567         int rc;
 568 
 569         if (!ipv6_addr_any(&sk->sk_v6_daddr)) {
 570                 sock_rps_save_rxhash(sk, skb);
 571                 sk_mark_napi_id(sk, skb);
 572                 sk_incoming_cpu_update(sk);
 573         } else {
 574                 sk_mark_napi_id_once(sk, skb);
 575         }
 576 
 577         rc = __udp_enqueue_schedule_skb(sk, skb);
 578         if (rc < 0) {
 579                 int is_udplite = IS_UDPLITE(sk);
 580 
 581                 /* Note that an ENOMEM error is charged twice */
 582                 if (rc == -ENOMEM)
 583                         UDP6_INC_STATS(sock_net(sk),
 584                                          UDP_MIB_RCVBUFERRORS, is_udplite);
 585                 UDP6_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
 586                 kfree_skb(skb);
 587                 return -1;
 588         }
 589 
 590         return 0;
 591 }
 592 
 593 static __inline__ int udpv6_err(struct sk_buff *skb,
 594                                 struct inet6_skb_parm *opt, u8 type,
 595                                 u8 code, int offset, __be32 info)
 596 {
 597         return __udp6_lib_err(skb, opt, type, code, offset, info, &udp_table);
 598 }
 599 
 600 static int udpv6_queue_rcv_one_skb(struct sock *sk, struct sk_buff *skb)
 601 {
 602         struct udp_sock *up = udp_sk(sk);
 603         int is_udplite = IS_UDPLITE(sk);
 604 
 605         if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
 606                 goto drop;
 607 
 608         if (static_branch_unlikely(&udpv6_encap_needed_key) && up->encap_type) {
 609                 int (*encap_rcv)(struct sock *sk, struct sk_buff *skb);
 610 
 611                 /*
 612                  * This is an encapsulation socket so pass the skb to
 613                  * the socket's udp_encap_rcv() hook. Otherwise, just
 614                  * fall through and pass this up the UDP socket.
 615                  * up->encap_rcv() returns the following value:
 616                  * =0 if skb was successfully passed to the encap
 617                  *    handler or was discarded by it.
 618                  * >0 if skb should be passed on to UDP.
 619                  * <0 if skb should be resubmitted as proto -N
 620                  */
 621 
 622                 /* if we're overly short, let UDP handle it */
 623                 encap_rcv = READ_ONCE(up->encap_rcv);
 624                 if (encap_rcv) {
 625                         int ret;
 626 
 627                         /* Verify checksum before giving to encap */
 628                         if (udp_lib_checksum_complete(skb))
 629                                 goto csum_error;
 630 
 631                         ret = encap_rcv(sk, skb);
 632                         if (ret <= 0) {
 633                                 __UDP_INC_STATS(sock_net(sk),
 634                                                 UDP_MIB_INDATAGRAMS,
 635                                                 is_udplite);
 636                                 return -ret;
 637                         }
 638                 }
 639 
 640                 /* FALLTHROUGH -- it's a UDP Packet */
 641         }
 642 
 643         /*
 644          * UDP-Lite specific tests, ignored on UDP sockets (see net/ipv4/udp.c).
 645          */
 646         if ((is_udplite & UDPLITE_RECV_CC)  &&  UDP_SKB_CB(skb)->partial_cov) {
 647 
 648                 if (up->pcrlen == 0) {          /* full coverage was set  */
 649                         net_dbg_ratelimited("UDPLITE6: partial coverage %d while full coverage %d requested\n",
 650                                             UDP_SKB_CB(skb)->cscov, skb->len);
 651                         goto drop;
 652                 }
 653                 if (UDP_SKB_CB(skb)->cscov  <  up->pcrlen) {
 654                         net_dbg_ratelimited("UDPLITE6: coverage %d too small, need min %d\n",
 655                                             UDP_SKB_CB(skb)->cscov, up->pcrlen);
 656                         goto drop;
 657                 }
 658         }
 659 
 660         prefetch(&sk->sk_rmem_alloc);
 661         if (rcu_access_pointer(sk->sk_filter) &&
 662             udp_lib_checksum_complete(skb))
 663                 goto csum_error;
 664 
 665         if (sk_filter_trim_cap(sk, skb, sizeof(struct udphdr)))
 666                 goto drop;
 667 
 668         udp_csum_pull_header(skb);
 669 
 670         skb_dst_drop(skb);
 671 
 672         return __udpv6_queue_rcv_skb(sk, skb);
 673 
 674 csum_error:
 675         __UDP6_INC_STATS(sock_net(sk), UDP_MIB_CSUMERRORS, is_udplite);
 676 drop:
 677         __UDP6_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
 678         atomic_inc(&sk->sk_drops);
 679         kfree_skb(skb);
 680         return -1;
 681 }
 682 
 683 static int udpv6_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
 684 {
 685         struct sk_buff *next, *segs;
 686         int ret;
 687 
 688         if (likely(!udp_unexpected_gso(sk, skb)))
 689                 return udpv6_queue_rcv_one_skb(sk, skb);
 690 
 691         __skb_push(skb, -skb_mac_offset(skb));
 692         segs = udp_rcv_segment(sk, skb, false);
 693         for (skb = segs; skb; skb = next) {
 694                 next = skb->next;
 695                 __skb_pull(skb, skb_transport_offset(skb));
 696 
 697                 ret = udpv6_queue_rcv_one_skb(sk, skb);
 698                 if (ret > 0)
 699                         ip6_protocol_deliver_rcu(dev_net(skb->dev), skb, ret,
 700                                                  true);
 701         }
 702         return 0;
 703 }
 704 
 705 static bool __udp_v6_is_mcast_sock(struct net *net, struct sock *sk,
 706                                    __be16 loc_port, const struct in6_addr *loc_addr,
 707                                    __be16 rmt_port, const struct in6_addr *rmt_addr,
 708                                    int dif, int sdif, unsigned short hnum)
 709 {
 710         struct inet_sock *inet = inet_sk(sk);
 711 
 712         if (!net_eq(sock_net(sk), net))
 713                 return false;
 714 
 715         if (udp_sk(sk)->udp_port_hash != hnum ||
 716             sk->sk_family != PF_INET6 ||
 717             (inet->inet_dport && inet->inet_dport != rmt_port) ||
 718             (!ipv6_addr_any(&sk->sk_v6_daddr) &&
 719                     !ipv6_addr_equal(&sk->sk_v6_daddr, rmt_addr)) ||
 720             !udp_sk_bound_dev_eq(net, sk->sk_bound_dev_if, dif, sdif) ||
 721             (!ipv6_addr_any(&sk->sk_v6_rcv_saddr) &&
 722                     !ipv6_addr_equal(&sk->sk_v6_rcv_saddr, loc_addr)))
 723                 return false;
 724         if (!inet6_mc_check(sk, loc_addr, rmt_addr))
 725                 return false;
 726         return true;
 727 }
 728 
 729 static void udp6_csum_zero_error(struct sk_buff *skb)
 730 {
 731         /* RFC 2460 section 8.1 says that we SHOULD log
 732          * this error. Well, it is reasonable.
 733          */
 734         net_dbg_ratelimited("IPv6: udp checksum is 0 for [%pI6c]:%u->[%pI6c]:%u\n",
 735                             &ipv6_hdr(skb)->saddr, ntohs(udp_hdr(skb)->source),
 736                             &ipv6_hdr(skb)->daddr, ntohs(udp_hdr(skb)->dest));
 737 }
 738 
 739 /*
 740  * Note: called only from the BH handler context,
 741  * so we don't need to lock the hashes.
 742  */
 743 static int __udp6_lib_mcast_deliver(struct net *net, struct sk_buff *skb,
 744                 const struct in6_addr *saddr, const struct in6_addr *daddr,
 745                 struct udp_table *udptable, int proto)
 746 {
 747         struct sock *sk, *first = NULL;
 748         const struct udphdr *uh = udp_hdr(skb);
 749         unsigned short hnum = ntohs(uh->dest);
 750         struct udp_hslot *hslot = udp_hashslot(udptable, net, hnum);
 751         unsigned int offset = offsetof(typeof(*sk), sk_node);
 752         unsigned int hash2 = 0, hash2_any = 0, use_hash2 = (hslot->count > 10);
 753         int dif = inet6_iif(skb);
 754         int sdif = inet6_sdif(skb);
 755         struct hlist_node *node;
 756         struct sk_buff *nskb;
 757 
 758         if (use_hash2) {
 759                 hash2_any = ipv6_portaddr_hash(net, &in6addr_any, hnum) &
 760                             udptable->mask;
 761                 hash2 = ipv6_portaddr_hash(net, daddr, hnum) & udptable->mask;
 762 start_lookup:
 763                 hslot = &udptable->hash2[hash2];
 764                 offset = offsetof(typeof(*sk), __sk_common.skc_portaddr_node);
 765         }
 766 
 767         sk_for_each_entry_offset_rcu(sk, node, &hslot->head, offset) {
 768                 if (!__udp_v6_is_mcast_sock(net, sk, uh->dest, daddr,
 769                                             uh->source, saddr, dif, sdif,
 770                                             hnum))
 771                         continue;
 772                 /* If zero checksum and no_check is not on for
 773                  * the socket then skip it.
 774                  */
 775                 if (!uh->check && !udp_sk(sk)->no_check6_rx)
 776                         continue;
 777                 if (!first) {
 778                         first = sk;
 779                         continue;
 780                 }
 781                 nskb = skb_clone(skb, GFP_ATOMIC);
 782                 if (unlikely(!nskb)) {
 783                         atomic_inc(&sk->sk_drops);
 784                         __UDP6_INC_STATS(net, UDP_MIB_RCVBUFERRORS,
 785                                          IS_UDPLITE(sk));
 786                         __UDP6_INC_STATS(net, UDP_MIB_INERRORS,
 787                                          IS_UDPLITE(sk));
 788                         continue;
 789                 }
 790 
 791                 if (udpv6_queue_rcv_skb(sk, nskb) > 0)
 792                         consume_skb(nskb);
 793         }
 794 
 795         /* Also lookup *:port if we are using hash2 and haven't done so yet. */
 796         if (use_hash2 && hash2 != hash2_any) {
 797                 hash2 = hash2_any;
 798                 goto start_lookup;
 799         }
 800 
 801         if (first) {
 802                 if (udpv6_queue_rcv_skb(first, skb) > 0)
 803                         consume_skb(skb);
 804         } else {
 805                 kfree_skb(skb);
 806                 __UDP6_INC_STATS(net, UDP_MIB_IGNOREDMULTI,
 807                                  proto == IPPROTO_UDPLITE);
 808         }
 809         return 0;
 810 }
 811 
 812 static void udp6_sk_rx_dst_set(struct sock *sk, struct dst_entry *dst)
 813 {
 814         if (udp_sk_rx_dst_set(sk, dst)) {
 815                 const struct rt6_info *rt = (const struct rt6_info *)dst;
 816 
 817                 inet6_sk(sk)->rx_dst_cookie = rt6_get_cookie(rt);
 818         }
 819 }
 820 
 821 /* wrapper for udp_queue_rcv_skb tacking care of csum conversion and
 822  * return code conversion for ip layer consumption
 823  */
 824 static int udp6_unicast_rcv_skb(struct sock *sk, struct sk_buff *skb,
 825                                 struct udphdr *uh)
 826 {
 827         int ret;
 828 
 829         if (inet_get_convert_csum(sk) && uh->check && !IS_UDPLITE(sk))
 830                 skb_checksum_try_convert(skb, IPPROTO_UDP, ip6_compute_pseudo);
 831 
 832         ret = udpv6_queue_rcv_skb(sk, skb);
 833 
 834         /* a return value > 0 means to resubmit the input */
 835         if (ret > 0)
 836                 return ret;
 837         return 0;
 838 }
 839 
 840 int __udp6_lib_rcv(struct sk_buff *skb, struct udp_table *udptable,
 841                    int proto)
 842 {
 843         const struct in6_addr *saddr, *daddr;
 844         struct net *net = dev_net(skb->dev);
 845         struct udphdr *uh;
 846         struct sock *sk;
 847         u32 ulen = 0;
 848 
 849         if (!pskb_may_pull(skb, sizeof(struct udphdr)))
 850                 goto discard;
 851 
 852         saddr = &ipv6_hdr(skb)->saddr;
 853         daddr = &ipv6_hdr(skb)->daddr;
 854         uh = udp_hdr(skb);
 855 
 856         ulen = ntohs(uh->len);
 857         if (ulen > skb->len)
 858                 goto short_packet;
 859 
 860         if (proto == IPPROTO_UDP) {
 861                 /* UDP validates ulen. */
 862 
 863                 /* Check for jumbo payload */
 864                 if (ulen == 0)
 865                         ulen = skb->len;
 866 
 867                 if (ulen < sizeof(*uh))
 868                         goto short_packet;
 869 
 870                 if (ulen < skb->len) {
 871                         if (pskb_trim_rcsum(skb, ulen))
 872                                 goto short_packet;
 873                         saddr = &ipv6_hdr(skb)->saddr;
 874                         daddr = &ipv6_hdr(skb)->daddr;
 875                         uh = udp_hdr(skb);
 876                 }
 877         }
 878 
 879         if (udp6_csum_init(skb, uh, proto))
 880                 goto csum_error;
 881 
 882         /* Check if the socket is already available, e.g. due to early demux */
 883         sk = skb_steal_sock(skb);
 884         if (sk) {
 885                 struct dst_entry *dst = skb_dst(skb);
 886                 int ret;
 887 
 888                 if (unlikely(sk->sk_rx_dst != dst))
 889                         udp6_sk_rx_dst_set(sk, dst);
 890 
 891                 if (!uh->check && !udp_sk(sk)->no_check6_rx) {
 892                         sock_put(sk);
 893                         goto report_csum_error;
 894                 }
 895 
 896                 ret = udp6_unicast_rcv_skb(sk, skb, uh);
 897                 sock_put(sk);
 898                 return ret;
 899         }
 900 
 901         /*
 902          *      Multicast receive code
 903          */
 904         if (ipv6_addr_is_multicast(daddr))
 905                 return __udp6_lib_mcast_deliver(net, skb,
 906                                 saddr, daddr, udptable, proto);
 907 
 908         /* Unicast */
 909         sk = __udp6_lib_lookup_skb(skb, uh->source, uh->dest, udptable);
 910         if (sk) {
 911                 if (!uh->check && !udp_sk(sk)->no_check6_rx)
 912                         goto report_csum_error;
 913                 return udp6_unicast_rcv_skb(sk, skb, uh);
 914         }
 915 
 916         if (!uh->check)
 917                 goto report_csum_error;
 918 
 919         if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
 920                 goto discard;
 921 
 922         if (udp_lib_checksum_complete(skb))
 923                 goto csum_error;
 924 
 925         __UDP6_INC_STATS(net, UDP_MIB_NOPORTS, proto == IPPROTO_UDPLITE);
 926         icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0);
 927 
 928         kfree_skb(skb);
 929         return 0;
 930 
 931 short_packet:
 932         net_dbg_ratelimited("UDP%sv6: short packet: From [%pI6c]:%u %d/%d to [%pI6c]:%u\n",
 933                             proto == IPPROTO_UDPLITE ? "-Lite" : "",
 934                             saddr, ntohs(uh->source),
 935                             ulen, skb->len,
 936                             daddr, ntohs(uh->dest));
 937         goto discard;
 938 
 939 report_csum_error:
 940         udp6_csum_zero_error(skb);
 941 csum_error:
 942         __UDP6_INC_STATS(net, UDP_MIB_CSUMERRORS, proto == IPPROTO_UDPLITE);
 943 discard:
 944         __UDP6_INC_STATS(net, UDP_MIB_INERRORS, proto == IPPROTO_UDPLITE);
 945         kfree_skb(skb);
 946         return 0;
 947 }
 948 
 949 
 950 static struct sock *__udp6_lib_demux_lookup(struct net *net,
 951                         __be16 loc_port, const struct in6_addr *loc_addr,
 952                         __be16 rmt_port, const struct in6_addr *rmt_addr,
 953                         int dif, int sdif)
 954 {
 955         unsigned short hnum = ntohs(loc_port);
 956         unsigned int hash2 = ipv6_portaddr_hash(net, loc_addr, hnum);
 957         unsigned int slot2 = hash2 & udp_table.mask;
 958         struct udp_hslot *hslot2 = &udp_table.hash2[slot2];
 959         const __portpair ports = INET_COMBINED_PORTS(rmt_port, hnum);
 960         struct sock *sk;
 961 
 962         udp_portaddr_for_each_entry_rcu(sk, &hslot2->head) {
 963                 if (sk->sk_state == TCP_ESTABLISHED &&
 964                     INET6_MATCH(sk, net, rmt_addr, loc_addr, ports, dif, sdif))
 965                         return sk;
 966                 /* Only check first socket in chain */
 967                 break;
 968         }
 969         return NULL;
 970 }
 971 
 972 INDIRECT_CALLABLE_SCOPE void udp_v6_early_demux(struct sk_buff *skb)
 973 {
 974         struct net *net = dev_net(skb->dev);
 975         const struct udphdr *uh;
 976         struct sock *sk;
 977         struct dst_entry *dst;
 978         int dif = skb->dev->ifindex;
 979         int sdif = inet6_sdif(skb);
 980 
 981         if (!pskb_may_pull(skb, skb_transport_offset(skb) +
 982             sizeof(struct udphdr)))
 983                 return;
 984 
 985         uh = udp_hdr(skb);
 986 
 987         if (skb->pkt_type == PACKET_HOST)
 988                 sk = __udp6_lib_demux_lookup(net, uh->dest,
 989                                              &ipv6_hdr(skb)->daddr,
 990                                              uh->source, &ipv6_hdr(skb)->saddr,
 991                                              dif, sdif);
 992         else
 993                 return;
 994 
 995         if (!sk || !refcount_inc_not_zero(&sk->sk_refcnt))
 996                 return;
 997 
 998         skb->sk = sk;
 999         skb->destructor = sock_efree;
1000         dst = READ_ONCE(sk->sk_rx_dst);
1001 
1002         if (dst)
1003                 dst = dst_check(dst, inet6_sk(sk)->rx_dst_cookie);
1004         if (dst) {
1005                 /* set noref for now.
1006                  * any place which wants to hold dst has to call
1007                  * dst_hold_safe()
1008                  */
1009                 skb_dst_set_noref(skb, dst);
1010         }
1011 }
1012 
1013 INDIRECT_CALLABLE_SCOPE int udpv6_rcv(struct sk_buff *skb)
1014 {
1015         return __udp6_lib_rcv(skb, &udp_table, IPPROTO_UDP);
1016 }
1017 
1018 /*
1019  * Throw away all pending data and cancel the corking. Socket is locked.
1020  */
1021 static void udp_v6_flush_pending_frames(struct sock *sk)
1022 {
1023         struct udp_sock *up = udp_sk(sk);
1024 
1025         if (up->pending == AF_INET)
1026                 udp_flush_pending_frames(sk);
1027         else if (up->pending) {
1028                 up->len = 0;
1029                 up->pending = 0;
1030                 ip6_flush_pending_frames(sk);
1031         }
1032 }
1033 
1034 static int udpv6_pre_connect(struct sock *sk, struct sockaddr *uaddr,
1035                              int addr_len)
1036 {
1037         if (addr_len < offsetofend(struct sockaddr, sa_family))
1038                 return -EINVAL;
1039         /* The following checks are replicated from __ip6_datagram_connect()
1040          * and intended to prevent BPF program called below from accessing
1041          * bytes that are out of the bound specified by user in addr_len.
1042          */
1043         if (uaddr->sa_family == AF_INET) {
1044                 if (__ipv6_only_sock(sk))
1045                         return -EAFNOSUPPORT;
1046                 return udp_pre_connect(sk, uaddr, addr_len);
1047         }
1048 
1049         if (addr_len < SIN6_LEN_RFC2133)
1050                 return -EINVAL;
1051 
1052         return BPF_CGROUP_RUN_PROG_INET6_CONNECT_LOCK(sk, uaddr);
1053 }
1054 
1055 /**
1056  *      udp6_hwcsum_outgoing  -  handle outgoing HW checksumming
1057  *      @sk:    socket we are sending on
1058  *      @skb:   sk_buff containing the filled-in UDP header
1059  *              (checksum field must be zeroed out)
1060  */
1061 static void udp6_hwcsum_outgoing(struct sock *sk, struct sk_buff *skb,
1062                                  const struct in6_addr *saddr,
1063                                  const struct in6_addr *daddr, int len)
1064 {
1065         unsigned int offset;
1066         struct udphdr *uh = udp_hdr(skb);
1067         struct sk_buff *frags = skb_shinfo(skb)->frag_list;
1068         __wsum csum = 0;
1069 
1070         if (!frags) {
1071                 /* Only one fragment on the socket.  */
1072                 skb->csum_start = skb_transport_header(skb) - skb->head;
1073                 skb->csum_offset = offsetof(struct udphdr, check);
1074                 uh->check = ~csum_ipv6_magic(saddr, daddr, len, IPPROTO_UDP, 0);
1075         } else {
1076                 /*
1077                  * HW-checksum won't work as there are two or more
1078                  * fragments on the socket so that all csums of sk_buffs
1079                  * should be together
1080                  */
1081                 offset = skb_transport_offset(skb);
1082                 skb->csum = skb_checksum(skb, offset, skb->len - offset, 0);
1083                 csum = skb->csum;
1084 
1085                 skb->ip_summed = CHECKSUM_NONE;
1086 
1087                 do {
1088                         csum = csum_add(csum, frags->csum);
1089                 } while ((frags = frags->next));
1090 
1091                 uh->check = csum_ipv6_magic(saddr, daddr, len, IPPROTO_UDP,
1092                                             csum);
1093                 if (uh->check == 0)
1094                         uh->check = CSUM_MANGLED_0;
1095         }
1096 }
1097 
1098 /*
1099  *      Sending
1100  */
1101 
1102 static int udp_v6_send_skb(struct sk_buff *skb, struct flowi6 *fl6,
1103                            struct inet_cork *cork)
1104 {
1105         struct sock *sk = skb->sk;
1106         struct udphdr *uh;
1107         int err = 0;
1108         int is_udplite = IS_UDPLITE(sk);
1109         __wsum csum = 0;
1110         int offset = skb_transport_offset(skb);
1111         int len = skb->len - offset;
1112         int datalen = len - sizeof(*uh);
1113 
1114         /*
1115          * Create a UDP header
1116          */
1117         uh = udp_hdr(skb);
1118         uh->source = fl6->fl6_sport;
1119         uh->dest = fl6->fl6_dport;
1120         uh->len = htons(len);
1121         uh->check = 0;
1122 
1123         if (cork->gso_size) {
1124                 const int hlen = skb_network_header_len(skb) +
1125                                  sizeof(struct udphdr);
1126 
1127                 if (hlen + cork->gso_size > cork->fragsize) {
1128                         kfree_skb(skb);
1129                         return -EINVAL;
1130                 }
1131                 if (skb->len > cork->gso_size * UDP_MAX_SEGMENTS) {
1132                         kfree_skb(skb);
1133                         return -EINVAL;
1134                 }
1135                 if (udp_sk(sk)->no_check6_tx) {
1136                         kfree_skb(skb);
1137                         return -EINVAL;
1138                 }
1139                 if (skb->ip_summed != CHECKSUM_PARTIAL || is_udplite ||
1140                     dst_xfrm(skb_dst(skb))) {
1141                         kfree_skb(skb);
1142                         return -EIO;
1143                 }
1144 
1145                 if (datalen > cork->gso_size) {
1146                         skb_shinfo(skb)->gso_size = cork->gso_size;
1147                         skb_shinfo(skb)->gso_type = SKB_GSO_UDP_L4;
1148                         skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(datalen,
1149                                                                  cork->gso_size);
1150                 }
1151                 goto csum_partial;
1152         }
1153 
1154         if (is_udplite)
1155                 csum = udplite_csum(skb);
1156         else if (udp_sk(sk)->no_check6_tx) {   /* UDP csum disabled */
1157                 skb->ip_summed = CHECKSUM_NONE;
1158                 goto send;
1159         } else if (skb->ip_summed == CHECKSUM_PARTIAL) { /* UDP hardware csum */
1160 csum_partial:
1161                 udp6_hwcsum_outgoing(sk, skb, &fl6->saddr, &fl6->daddr, len);
1162                 goto send;
1163         } else
1164                 csum = udp_csum(skb);
1165 
1166         /* add protocol-dependent pseudo-header */
1167         uh->check = csum_ipv6_magic(&fl6->saddr, &fl6->daddr,
1168                                     len, fl6->flowi6_proto, csum);
1169         if (uh->check == 0)
1170                 uh->check = CSUM_MANGLED_0;
1171 
1172 send:
1173         err = ip6_send_skb(skb);
1174         if (err) {
1175                 if (err == -ENOBUFS && !inet6_sk(sk)->recverr) {
1176                         UDP6_INC_STATS(sock_net(sk),
1177                                        UDP_MIB_SNDBUFERRORS, is_udplite);
1178                         err = 0;
1179                 }
1180         } else {
1181                 UDP6_INC_STATS(sock_net(sk),
1182                                UDP_MIB_OUTDATAGRAMS, is_udplite);
1183         }
1184         return err;
1185 }
1186 
1187 static int udp_v6_push_pending_frames(struct sock *sk)
1188 {
1189         struct sk_buff *skb;
1190         struct udp_sock  *up = udp_sk(sk);
1191         struct flowi6 fl6;
1192         int err = 0;
1193 
1194         if (up->pending == AF_INET)
1195                 return udp_push_pending_frames(sk);
1196 
1197         /* ip6_finish_skb will release the cork, so make a copy of
1198          * fl6 here.
1199          */
1200         fl6 = inet_sk(sk)->cork.fl.u.ip6;
1201 
1202         skb = ip6_finish_skb(sk);
1203         if (!skb)
1204                 goto out;
1205 
1206         err = udp_v6_send_skb(skb, &fl6, &inet_sk(sk)->cork.base);
1207 
1208 out:
1209         up->len = 0;
1210         up->pending = 0;
1211         return err;
1212 }
1213 
1214 int udpv6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
1215 {
1216         struct ipv6_txoptions opt_space;
1217         struct udp_sock *up = udp_sk(sk);
1218         struct inet_sock *inet = inet_sk(sk);
1219         struct ipv6_pinfo *np = inet6_sk(sk);
1220         DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name);
1221         struct in6_addr *daddr, *final_p, final;
1222         struct ipv6_txoptions *opt = NULL;
1223         struct ipv6_txoptions *opt_to_free = NULL;
1224         struct ip6_flowlabel *flowlabel = NULL;
1225         struct flowi6 fl6;
1226         struct dst_entry *dst;
1227         struct ipcm6_cookie ipc6;
1228         int addr_len = msg->msg_namelen;
1229         bool connected = false;
1230         int ulen = len;
1231         int corkreq = up->corkflag || msg->msg_flags&MSG_MORE;
1232         int err;
1233         int is_udplite = IS_UDPLITE(sk);
1234         int (*getfrag)(void *, char *, int, int, int, struct sk_buff *);
1235 
1236         ipcm6_init(&ipc6);
1237         ipc6.gso_size = up->gso_size;
1238         ipc6.sockc.tsflags = sk->sk_tsflags;
1239         ipc6.sockc.mark = sk->sk_mark;
1240 
1241         /* destination address check */
1242         if (sin6) {
1243                 if (addr_len < offsetof(struct sockaddr, sa_data))
1244                         return -EINVAL;
1245 
1246                 switch (sin6->sin6_family) {
1247                 case AF_INET6:
1248                         if (addr_len < SIN6_LEN_RFC2133)
1249                                 return -EINVAL;
1250                         daddr = &sin6->sin6_addr;
1251                         if (ipv6_addr_any(daddr) &&
1252                             ipv6_addr_v4mapped(&np->saddr))
1253                                 ipv6_addr_set_v4mapped(htonl(INADDR_LOOPBACK),
1254                                                        daddr);
1255                         break;
1256                 case AF_INET:
1257                         goto do_udp_sendmsg;
1258                 case AF_UNSPEC:
1259                         msg->msg_name = sin6 = NULL;
1260                         msg->msg_namelen = addr_len = 0;
1261                         daddr = NULL;
1262                         break;
1263                 default:
1264                         return -EINVAL;
1265                 }
1266         } else if (!up->pending) {
1267                 if (sk->sk_state != TCP_ESTABLISHED)
1268                         return -EDESTADDRREQ;
1269                 daddr = &sk->sk_v6_daddr;
1270         } else
1271                 daddr = NULL;
1272 
1273         if (daddr) {
1274                 if (ipv6_addr_v4mapped(daddr)) {
1275                         struct sockaddr_in sin;
1276                         sin.sin_family = AF_INET;
1277                         sin.sin_port = sin6 ? sin6->sin6_port : inet->inet_dport;
1278                         sin.sin_addr.s_addr = daddr->s6_addr32[3];
1279                         msg->msg_name = &sin;
1280                         msg->msg_namelen = sizeof(sin);
1281 do_udp_sendmsg:
1282                         if (__ipv6_only_sock(sk))
1283                                 return -ENETUNREACH;
1284                         return udp_sendmsg(sk, msg, len);
1285                 }
1286         }
1287 
1288         if (up->pending == AF_INET)
1289                 return udp_sendmsg(sk, msg, len);
1290 
1291         /* Rough check on arithmetic overflow,
1292            better check is made in ip6_append_data().
1293            */
1294         if (len > INT_MAX - sizeof(struct udphdr))
1295                 return -EMSGSIZE;
1296 
1297         getfrag  =  is_udplite ?  udplite_getfrag : ip_generic_getfrag;
1298         if (up->pending) {
1299                 /*
1300                  * There are pending frames.
1301                  * The socket lock must be held while it's corked.
1302                  */
1303                 lock_sock(sk);
1304                 if (likely(up->pending)) {
1305                         if (unlikely(up->pending != AF_INET6)) {
1306                                 release_sock(sk);
1307                                 return -EAFNOSUPPORT;
1308                         }
1309                         dst = NULL;
1310                         goto do_append_data;
1311                 }
1312                 release_sock(sk);
1313         }
1314         ulen += sizeof(struct udphdr);
1315 
1316         memset(&fl6, 0, sizeof(fl6));
1317 
1318         if (sin6) {
1319                 if (sin6->sin6_port == 0)
1320                         return -EINVAL;
1321 
1322                 fl6.fl6_dport = sin6->sin6_port;
1323                 daddr = &sin6->sin6_addr;
1324 
1325                 if (np->sndflow) {
1326                         fl6.flowlabel = sin6->sin6_flowinfo&IPV6_FLOWINFO_MASK;
1327                         if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) {
1328                                 flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
1329                                 if (IS_ERR(flowlabel))
1330                                         return -EINVAL;
1331                         }
1332                 }
1333 
1334                 /*
1335                  * Otherwise it will be difficult to maintain
1336                  * sk->sk_dst_cache.
1337                  */
1338                 if (sk->sk_state == TCP_ESTABLISHED &&
1339                     ipv6_addr_equal(daddr, &sk->sk_v6_daddr))
1340                         daddr = &sk->sk_v6_daddr;
1341 
1342                 if (addr_len >= sizeof(struct sockaddr_in6) &&
1343                     sin6->sin6_scope_id &&
1344                     __ipv6_addr_needs_scope_id(__ipv6_addr_type(daddr)))
1345                         fl6.flowi6_oif = sin6->sin6_scope_id;
1346         } else {
1347                 if (sk->sk_state != TCP_ESTABLISHED)
1348                         return -EDESTADDRREQ;
1349 
1350                 fl6.fl6_dport = inet->inet_dport;
1351                 daddr = &sk->sk_v6_daddr;
1352                 fl6.flowlabel = np->flow_label;
1353                 connected = true;
1354         }
1355 
1356         if (!fl6.flowi6_oif)
1357                 fl6.flowi6_oif = sk->sk_bound_dev_if;
1358 
1359         if (!fl6.flowi6_oif)
1360                 fl6.flowi6_oif = np->sticky_pktinfo.ipi6_ifindex;
1361 
1362         fl6.flowi6_mark = ipc6.sockc.mark;
1363         fl6.flowi6_uid = sk->sk_uid;
1364 
1365         if (msg->msg_controllen) {
1366                 opt = &opt_space;
1367                 memset(opt, 0, sizeof(struct ipv6_txoptions));
1368                 opt->tot_len = sizeof(*opt);
1369                 ipc6.opt = opt;
1370 
1371                 err = udp_cmsg_send(sk, msg, &ipc6.gso_size);
1372                 if (err > 0)
1373                         err = ip6_datagram_send_ctl(sock_net(sk), sk, msg, &fl6,
1374                                                     &ipc6);
1375                 if (err < 0) {
1376                         fl6_sock_release(flowlabel);
1377                         return err;
1378                 }
1379                 if ((fl6.flowlabel&IPV6_FLOWLABEL_MASK) && !flowlabel) {
1380                         flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
1381                         if (IS_ERR(flowlabel))
1382                                 return -EINVAL;
1383                 }
1384                 if (!(opt->opt_nflen|opt->opt_flen))
1385                         opt = NULL;
1386                 connected = false;
1387         }
1388         if (!opt) {
1389                 opt = txopt_get(np);
1390                 opt_to_free = opt;
1391         }
1392         if (flowlabel)
1393                 opt = fl6_merge_options(&opt_space, flowlabel, opt);
1394         opt = ipv6_fixup_options(&opt_space, opt);
1395         ipc6.opt = opt;
1396 
1397         fl6.flowi6_proto = sk->sk_protocol;
1398         fl6.daddr = *daddr;
1399         if (ipv6_addr_any(&fl6.saddr) && !ipv6_addr_any(&np->saddr))
1400                 fl6.saddr = np->saddr;
1401         fl6.fl6_sport = inet->inet_sport;
1402 
1403         if (cgroup_bpf_enabled && !connected) {
1404                 err = BPF_CGROUP_RUN_PROG_UDP6_SENDMSG_LOCK(sk,
1405                                            (struct sockaddr *)sin6, &fl6.saddr);
1406                 if (err)
1407                         goto out_no_dst;
1408                 if (sin6) {
1409                         if (ipv6_addr_v4mapped(&sin6->sin6_addr)) {
1410                                 /* BPF program rewrote IPv6-only by IPv4-mapped
1411                                  * IPv6. It's currently unsupported.
1412                                  */
1413                                 err = -ENOTSUPP;
1414                                 goto out_no_dst;
1415                         }
1416                         if (sin6->sin6_port == 0) {
1417                                 /* BPF program set invalid port. Reject it. */
1418                                 err = -EINVAL;
1419                                 goto out_no_dst;
1420                         }
1421                         fl6.fl6_dport = sin6->sin6_port;
1422                         fl6.daddr = sin6->sin6_addr;
1423                 }
1424         }
1425 
1426         if (ipv6_addr_any(&fl6.daddr))
1427                 fl6.daddr.s6_addr[15] = 0x1; /* :: means loopback (BSD'ism) */
1428 
1429         final_p = fl6_update_dst(&fl6, opt, &final);
1430         if (final_p)
1431                 connected = false;
1432 
1433         if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr)) {
1434                 fl6.flowi6_oif = np->mcast_oif;
1435                 connected = false;
1436         } else if (!fl6.flowi6_oif)
1437                 fl6.flowi6_oif = np->ucast_oif;
1438 
1439         security_sk_classify_flow(sk, flowi6_to_flowi(&fl6));
1440 
1441         if (ipc6.tclass < 0)
1442                 ipc6.tclass = np->tclass;
1443 
1444         fl6.flowlabel = ip6_make_flowinfo(ipc6.tclass, fl6.flowlabel);
1445 
1446         dst = ip6_sk_dst_lookup_flow(sk, &fl6, final_p, connected);
1447         if (IS_ERR(dst)) {
1448                 err = PTR_ERR(dst);
1449                 dst = NULL;
1450                 goto out;
1451         }
1452 
1453         if (ipc6.hlimit < 0)
1454                 ipc6.hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst);
1455 
1456         if (msg->msg_flags&MSG_CONFIRM)
1457                 goto do_confirm;
1458 back_from_confirm:
1459 
1460         /* Lockless fast path for the non-corking case */
1461         if (!corkreq) {
1462                 struct inet_cork_full cork;
1463                 struct sk_buff *skb;
1464 
1465                 skb = ip6_make_skb(sk, getfrag, msg, ulen,
1466                                    sizeof(struct udphdr), &ipc6,
1467                                    &fl6, (struct rt6_info *)dst,
1468                                    msg->msg_flags, &cork);
1469                 err = PTR_ERR(skb);
1470                 if (!IS_ERR_OR_NULL(skb))
1471                         err = udp_v6_send_skb(skb, &fl6, &cork.base);
1472                 goto out;
1473         }
1474 
1475         lock_sock(sk);
1476         if (unlikely(up->pending)) {
1477                 /* The socket is already corked while preparing it. */
1478                 /* ... which is an evident application bug. --ANK */
1479                 release_sock(sk);
1480 
1481                 net_dbg_ratelimited("udp cork app bug 2\n");
1482                 err = -EINVAL;
1483                 goto out;
1484         }
1485 
1486         up->pending = AF_INET6;
1487 
1488 do_append_data:
1489         if (ipc6.dontfrag < 0)
1490                 ipc6.dontfrag = np->dontfrag;
1491         up->len += ulen;
1492         err = ip6_append_data(sk, getfrag, msg, ulen, sizeof(struct udphdr),
1493                               &ipc6, &fl6, (struct rt6_info *)dst,
1494                               corkreq ? msg->msg_flags|MSG_MORE : msg->msg_flags);
1495         if (err)
1496                 udp_v6_flush_pending_frames(sk);
1497         else if (!corkreq)
1498                 err = udp_v6_push_pending_frames(sk);
1499         else if (unlikely(skb_queue_empty(&sk->sk_write_queue)))
1500                 up->pending = 0;
1501 
1502         if (err > 0)
1503                 err = np->recverr ? net_xmit_errno(err) : 0;
1504         release_sock(sk);
1505 
1506 out:
1507         dst_release(dst);
1508 out_no_dst:
1509         fl6_sock_release(flowlabel);
1510         txopt_put(opt_to_free);
1511         if (!err)
1512                 return len;
1513         /*
1514          * ENOBUFS = no kernel mem, SOCK_NOSPACE = no sndbuf space.  Reporting
1515          * ENOBUFS might not be good (it's not tunable per se), but otherwise
1516          * we don't have a good statistic (IpOutDiscards but it can be too many
1517          * things).  We could add another new stat but at least for now that
1518          * seems like overkill.
1519          */
1520         if (err == -ENOBUFS || test_bit(SOCK_NOSPACE, &sk->sk_socket->flags)) {
1521                 UDP6_INC_STATS(sock_net(sk),
1522                                UDP_MIB_SNDBUFERRORS, is_udplite);
1523         }
1524         return err;
1525 
1526 do_confirm:
1527         if (msg->msg_flags & MSG_PROBE)
1528                 dst_confirm_neigh(dst, &fl6.daddr);
1529         if (!(msg->msg_flags&MSG_PROBE) || len)
1530                 goto back_from_confirm;
1531         err = 0;
1532         goto out;
1533 }
1534 
1535 void udpv6_destroy_sock(struct sock *sk)
1536 {
1537         struct udp_sock *up = udp_sk(sk);
1538         lock_sock(sk);
1539         udp_v6_flush_pending_frames(sk);
1540         release_sock(sk);
1541 
1542         if (static_branch_unlikely(&udpv6_encap_needed_key)) {
1543                 if (up->encap_type) {
1544                         void (*encap_destroy)(struct sock *sk);
1545                         encap_destroy = READ_ONCE(up->encap_destroy);
1546                         if (encap_destroy)
1547                                 encap_destroy(sk);
1548                 }
1549                 if (up->encap_enabled)
1550                         static_branch_dec(&udpv6_encap_needed_key);
1551         }
1552 
1553         inet6_destroy_sock(sk);
1554 }
1555 
1556 /*
1557  *      Socket option code for UDP
1558  */
1559 int udpv6_setsockopt(struct sock *sk, int level, int optname,
1560                      char __user *optval, unsigned int optlen)
1561 {
1562         if (level == SOL_UDP  ||  level == SOL_UDPLITE)
1563                 return udp_lib_setsockopt(sk, level, optname, optval, optlen,
1564                                           udp_v6_push_pending_frames);
1565         return ipv6_setsockopt(sk, level, optname, optval, optlen);
1566 }
1567 
1568 #ifdef CONFIG_COMPAT
1569 int compat_udpv6_setsockopt(struct sock *sk, int level, int optname,
1570                             char __user *optval, unsigned int optlen)
1571 {
1572         if (level == SOL_UDP  ||  level == SOL_UDPLITE)
1573                 return udp_lib_setsockopt(sk, level, optname, optval, optlen,
1574                                           udp_v6_push_pending_frames);
1575         return compat_ipv6_setsockopt(sk, level, optname, optval, optlen);
1576 }
1577 #endif
1578 
1579 int udpv6_getsockopt(struct sock *sk, int level, int optname,
1580                      char __user *optval, int __user *optlen)
1581 {
1582         if (level == SOL_UDP  ||  level == SOL_UDPLITE)
1583                 return udp_lib_getsockopt(sk, level, optname, optval, optlen);
1584         return ipv6_getsockopt(sk, level, optname, optval, optlen);
1585 }
1586 
1587 #ifdef CONFIG_COMPAT
1588 int compat_udpv6_getsockopt(struct sock *sk, int level, int optname,
1589                             char __user *optval, int __user *optlen)
1590 {
1591         if (level == SOL_UDP  ||  level == SOL_UDPLITE)
1592                 return udp_lib_getsockopt(sk, level, optname, optval, optlen);
1593         return compat_ipv6_getsockopt(sk, level, optname, optval, optlen);
1594 }
1595 #endif
1596 
1597 /* thinking of making this const? Don't.
1598  * early_demux can change based on sysctl.
1599  */
1600 static struct inet6_protocol udpv6_protocol = {
1601         .early_demux    =       udp_v6_early_demux,
1602         .early_demux_handler =  udp_v6_early_demux,
1603         .handler        =       udpv6_rcv,
1604         .err_handler    =       udpv6_err,
1605         .flags          =       INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
1606 };
1607 
1608 /* ------------------------------------------------------------------------ */
1609 #ifdef CONFIG_PROC_FS
1610 int udp6_seq_show(struct seq_file *seq, void *v)
1611 {
1612         if (v == SEQ_START_TOKEN) {
1613                 seq_puts(seq, IPV6_SEQ_DGRAM_HEADER);
1614         } else {
1615                 int bucket = ((struct udp_iter_state *)seq->private)->bucket;
1616                 struct inet_sock *inet = inet_sk(v);
1617                 __u16 srcp = ntohs(inet->inet_sport);
1618                 __u16 destp = ntohs(inet->inet_dport);
1619                 __ip6_dgram_sock_seq_show(seq, v, srcp, destp,
1620                                           udp_rqueue_get(v), bucket);
1621         }
1622         return 0;
1623 }
1624 
1625 const struct seq_operations udp6_seq_ops = {
1626         .start          = udp_seq_start,
1627         .next           = udp_seq_next,
1628         .stop           = udp_seq_stop,
1629         .show           = udp6_seq_show,
1630 };
1631 EXPORT_SYMBOL(udp6_seq_ops);
1632 
1633 static struct udp_seq_afinfo udp6_seq_afinfo = {
1634         .family         = AF_INET6,
1635         .udp_table      = &udp_table,
1636 };
1637 
1638 int __net_init udp6_proc_init(struct net *net)
1639 {
1640         if (!proc_create_net_data("udp6", 0444, net->proc_net, &udp6_seq_ops,
1641                         sizeof(struct udp_iter_state), &udp6_seq_afinfo))
1642                 return -ENOMEM;
1643         return 0;
1644 }
1645 
1646 void udp6_proc_exit(struct net *net)
1647 {
1648         remove_proc_entry("udp6", net->proc_net);
1649 }
1650 #endif /* CONFIG_PROC_FS */
1651 
1652 /* ------------------------------------------------------------------------ */
1653 
1654 struct proto udpv6_prot = {
1655         .name                   = "UDPv6",
1656         .owner                  = THIS_MODULE,
1657         .close                  = udp_lib_close,
1658         .pre_connect            = udpv6_pre_connect,
1659         .connect                = ip6_datagram_connect,
1660         .disconnect             = udp_disconnect,
1661         .ioctl                  = udp_ioctl,
1662         .init                   = udp_init_sock,
1663         .destroy                = udpv6_destroy_sock,
1664         .setsockopt             = udpv6_setsockopt,
1665         .getsockopt             = udpv6_getsockopt,
1666         .sendmsg                = udpv6_sendmsg,
1667         .recvmsg                = udpv6_recvmsg,
1668         .release_cb             = ip6_datagram_release_cb,
1669         .hash                   = udp_lib_hash,
1670         .unhash                 = udp_lib_unhash,
1671         .rehash                 = udp_v6_rehash,
1672         .get_port               = udp_v6_get_port,
1673         .memory_allocated       = &udp_memory_allocated,
1674         .sysctl_mem             = sysctl_udp_mem,
1675         .sysctl_wmem_offset     = offsetof(struct net, ipv4.sysctl_udp_wmem_min),
1676         .sysctl_rmem_offset     = offsetof(struct net, ipv4.sysctl_udp_rmem_min),
1677         .obj_size               = sizeof(struct udp6_sock),
1678         .h.udp_table            = &udp_table,
1679 #ifdef CONFIG_COMPAT
1680         .compat_setsockopt      = compat_udpv6_setsockopt,
1681         .compat_getsockopt      = compat_udpv6_getsockopt,
1682 #endif
1683         .diag_destroy           = udp_abort,
1684 };
1685 
1686 static struct inet_protosw udpv6_protosw = {
1687         .type =      SOCK_DGRAM,
1688         .protocol =  IPPROTO_UDP,
1689         .prot =      &udpv6_prot,
1690         .ops =       &inet6_dgram_ops,
1691         .flags =     INET_PROTOSW_PERMANENT,
1692 };
1693 
1694 int __init udpv6_init(void)
1695 {
1696         int ret;
1697 
1698         ret = inet6_add_protocol(&udpv6_protocol, IPPROTO_UDP);
1699         if (ret)
1700                 goto out;
1701 
1702         ret = inet6_register_protosw(&udpv6_protosw);
1703         if (ret)
1704                 goto out_udpv6_protocol;
1705 out:
1706         return ret;
1707 
1708 out_udpv6_protocol:
1709         inet6_del_protocol(&udpv6_protocol, IPPROTO_UDP);
1710         goto out;
1711 }
1712 
1713 void udpv6_exit(void)
1714 {
1715         inet6_unregister_protosw(&udpv6_protosw);
1716         inet6_del_protocol(&udpv6_protocol, IPPROTO_UDP);
1717 }
/* [<][>][^][v][top][bottom][index][help] */
root/net/ipv6/udp.c

DEFINITIONS
