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TOMOYO Linux Cross Reference
Linux/net/ipv6/udp.c

Version: ~ [ linux-5.4-rc7 ] ~ [ linux-5.3.11 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.84 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.154 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.201 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.201 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.19.8 ] ~ [ linux-3.18.140 ] ~ [ linux-3.17.8 ] ~ [ linux-3.16.77 ] ~ [ linux-3.15.10 ] ~ [ linux-3.14.79 ] ~ [ linux-3.13.11 ] ~ [ linux-3.12.74 ] ~ [ linux-3.11.10 ] ~ [ linux-3.10.108 ] ~ [ linux-3.9.11 ] ~ [ linux-3.8.13 ] ~ [ linux-3.7.10 ] ~ [ linux-3.6.11 ] ~ [ linux-3.5.7 ] ~ [ linux-3.4.113 ] ~ [ linux-3.3.8 ] ~ [ linux-3.2.102 ] ~ [ linux-3.1.10 ] ~ [ linux-3.0.101 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  1 /*
  2  *      UDP over IPv6
  3  *      Linux INET6 implementation
  4  *
  5  *      Authors:
  6  *      Pedro Roque             <roque@di.fc.ul.pt>
  7  *
  8  *      Based on linux/ipv4/udp.c
  9  *
 10  *      Fixes:
 11  *      Hideaki YOSHIFUJI       :       sin6_scope_id support
 12  *      YOSHIFUJI Hideaki @USAGI and:   Support IPV6_V6ONLY socket option, which
 13  *      Alexey Kuznetsov                allow both IPv4 and IPv6 sockets to bind
 14  *                                      a single port at the same time.
 15  *      Kazunori MIYAZAWA @USAGI:       change process style to use ip6_append_data
 16  *      YOSHIFUJI Hideaki @USAGI:       convert /proc/net/udp6 to seq_file.
 17  *
 18  *      This program is free software; you can redistribute it and/or
 19  *      modify it under the terms of the GNU General Public License
 20  *      as published by the Free Software Foundation; either version
 21  *      2 of the License, or (at your option) any later version.
 22  */
 23 
 24 #include <linux/errno.h>
 25 #include <linux/types.h>
 26 #include <linux/socket.h>
 27 #include <linux/sockios.h>
 28 #include <linux/net.h>
 29 #include <linux/in6.h>
 30 #include <linux/netdevice.h>
 31 #include <linux/if_arp.h>
 32 #include <linux/ipv6.h>
 33 #include <linux/icmpv6.h>
 34 #include <linux/init.h>
 35 #include <linux/module.h>
 36 #include <linux/skbuff.h>
 37 #include <linux/slab.h>
 38 #include <asm/uaccess.h>
 39 
 40 #include <net/ndisc.h>
 41 #include <net/protocol.h>
 42 #include <net/transp_v6.h>
 43 #include <net/ip6_route.h>
 44 #include <net/raw.h>
 45 #include <net/tcp_states.h>
 46 #include <net/ip6_checksum.h>
 47 #include <net/xfrm.h>
 48 #include <net/inet6_hashtables.h>
 49 
 50 #include <linux/proc_fs.h>
 51 #include <linux/seq_file.h>
 52 #include <trace/events/skb.h>
 53 #include "udp_impl.h"
 54 
 55 int ipv6_rcv_saddr_equal(const struct sock *sk, const struct sock *sk2)
 56 {
 57         const struct in6_addr *sk_rcv_saddr6 = &inet6_sk(sk)->rcv_saddr;
 58         const struct in6_addr *sk2_rcv_saddr6 = inet6_rcv_saddr(sk2);
 59         __be32 sk1_rcv_saddr = sk_rcv_saddr(sk);
 60         __be32 sk2_rcv_saddr = sk_rcv_saddr(sk2);
 61         int sk_ipv6only = ipv6_only_sock(sk);
 62         int sk2_ipv6only = inet_v6_ipv6only(sk2);
 63         int addr_type = ipv6_addr_type(sk_rcv_saddr6);
 64         int addr_type2 = sk2_rcv_saddr6 ? ipv6_addr_type(sk2_rcv_saddr6) : IPV6_ADDR_MAPPED;
 65 
 66         /* if both are mapped, treat as IPv4 */
 67         if (addr_type == IPV6_ADDR_MAPPED && addr_type2 == IPV6_ADDR_MAPPED)
 68                 return (!sk2_ipv6only &&
 69                         (!sk1_rcv_saddr || !sk2_rcv_saddr ||
 70                           sk1_rcv_saddr == sk2_rcv_saddr));
 71 
 72         if (addr_type2 == IPV6_ADDR_ANY &&
 73             !(sk2_ipv6only && addr_type == IPV6_ADDR_MAPPED))
 74                 return 1;
 75 
 76         if (addr_type == IPV6_ADDR_ANY &&
 77             !(sk_ipv6only && addr_type2 == IPV6_ADDR_MAPPED))
 78                 return 1;
 79 
 80         if (sk2_rcv_saddr6 &&
 81             ipv6_addr_equal(sk_rcv_saddr6, sk2_rcv_saddr6))
 82                 return 1;
 83 
 84         return 0;
 85 }
 86 
 87 static unsigned int udp6_portaddr_hash(struct net *net,
 88                                        const struct in6_addr *addr6,
 89                                        unsigned int port)
 90 {
 91         unsigned int hash, mix = net_hash_mix(net);
 92 
 93         if (ipv6_addr_any(addr6))
 94                 hash = jhash_1word(0, mix);
 95         else if (ipv6_addr_v4mapped(addr6))
 96                 hash = jhash_1word((__force u32)addr6->s6_addr32[3], mix);
 97         else
 98                 hash = jhash2((__force u32 *)addr6->s6_addr32, 4, mix);
 99 
100         return hash ^ port;
101 }
102 
103 
104 int udp_v6_get_port(struct sock *sk, unsigned short snum)
105 {
106         unsigned int hash2_nulladdr =
107                 udp6_portaddr_hash(sock_net(sk), &in6addr_any, snum);
108         unsigned int hash2_partial =
109                 udp6_portaddr_hash(sock_net(sk), &inet6_sk(sk)->rcv_saddr, 0);
110 
111         /* precompute partial secondary hash */
112         udp_sk(sk)->udp_portaddr_hash = hash2_partial;
113         return udp_lib_get_port(sk, snum, ipv6_rcv_saddr_equal, hash2_nulladdr);
114 }
115 
116 static void udp_v6_rehash(struct sock *sk)
117 {
118         u16 new_hash = udp6_portaddr_hash(sock_net(sk),
119                                           &inet6_sk(sk)->rcv_saddr,
120                                           inet_sk(sk)->inet_num);
121 
122         udp_lib_rehash(sk, new_hash);
123 }
124 
125 static inline int compute_score(struct sock *sk, struct net *net,
126                                 unsigned short hnum,
127                                 const struct in6_addr *saddr, __be16 sport,
128                                 const struct in6_addr *daddr, __be16 dport,
129                                 int dif)
130 {
131         int score = -1;
132 
133         if (net_eq(sock_net(sk), net) && udp_sk(sk)->udp_port_hash == hnum &&
134                         sk->sk_family == PF_INET6) {
135                 struct ipv6_pinfo *np = inet6_sk(sk);
136                 struct inet_sock *inet = inet_sk(sk);
137 
138                 score = 0;
139                 if (inet->inet_dport) {
140                         if (inet->inet_dport != sport)
141                                 return -1;
142                         score++;
143                 }
144                 if (!ipv6_addr_any(&np->rcv_saddr)) {
145                         if (!ipv6_addr_equal(&np->rcv_saddr, daddr))
146                                 return -1;
147                         score++;
148                 }
149                 if (!ipv6_addr_any(&np->daddr)) {
150                         if (!ipv6_addr_equal(&np->daddr, saddr))
151                                 return -1;
152                         score++;
153                 }
154                 if (sk->sk_bound_dev_if) {
155                         if (sk->sk_bound_dev_if != dif)
156                                 return -1;
157                         score++;
158                 }
159         }
160         return score;
161 }
162 
163 #define SCORE2_MAX (1 + 1 + 1)
164 static inline int compute_score2(struct sock *sk, struct net *net,
165                                 const struct in6_addr *saddr, __be16 sport,
166                                 const struct in6_addr *daddr, unsigned short hnum,
167                                 int dif)
168 {
169         int score = -1;
170 
171         if (net_eq(sock_net(sk), net) && udp_sk(sk)->udp_port_hash == hnum &&
172                         sk->sk_family == PF_INET6) {
173                 struct ipv6_pinfo *np = inet6_sk(sk);
174                 struct inet_sock *inet = inet_sk(sk);
175 
176                 if (!ipv6_addr_equal(&np->rcv_saddr, daddr))
177                         return -1;
178                 score = 0;
179                 if (inet->inet_dport) {
180                         if (inet->inet_dport != sport)
181                                 return -1;
182                         score++;
183                 }
184                 if (!ipv6_addr_any(&np->daddr)) {
185                         if (!ipv6_addr_equal(&np->daddr, saddr))
186                                 return -1;
187                         score++;
188                 }
189                 if (sk->sk_bound_dev_if) {
190                         if (sk->sk_bound_dev_if != dif)
191                                 return -1;
192                         score++;
193                 }
194         }
195         return score;
196 }
197 
198 
199 /* called with read_rcu_lock() */
200 static struct sock *udp6_lib_lookup2(struct net *net,
201                 const struct in6_addr *saddr, __be16 sport,
202                 const struct in6_addr *daddr, unsigned int hnum, int dif,
203                 struct udp_hslot *hslot2, unsigned int slot2)
204 {
205         struct sock *sk, *result;
206         struct hlist_nulls_node *node;
207         int score, badness, matches = 0, reuseport = 0;
208         u32 hash = 0;
209 
210 begin:
211         result = NULL;
212         badness = -1;
213         udp_portaddr_for_each_entry_rcu(sk, node, &hslot2->head) {
214                 score = compute_score2(sk, net, saddr, sport,
215                                       daddr, hnum, dif);
216                 if (score > badness) {
217                         result = sk;
218                         badness = score;
219                         reuseport = sk->sk_reuseport;
220                         if (reuseport) {
221                                 hash = inet6_ehashfn(net, daddr, hnum,
222                                                      saddr, sport);
223                                 matches = 1;
224                         } else if (score == SCORE2_MAX)
225                                 goto exact_match;
226                 } else if (score == badness && reuseport) {
227                         matches++;
228                         if (((u64)hash * matches) >> 32 == 0)
229                                 result = sk;
230                         hash = next_pseudo_random32(hash);
231                 }
232         }
233         /*
234          * if the nulls value we got at the end of this lookup is
235          * not the expected one, we must restart lookup.
236          * We probably met an item that was moved to another chain.
237          */
238         if (get_nulls_value(node) != slot2)
239                 goto begin;
240 
241         if (result) {
242 exact_match:
243                 if (unlikely(!atomic_inc_not_zero_hint(&result->sk_refcnt, 2)))
244                         result = NULL;
245                 else if (unlikely(compute_score2(result, net, saddr, sport,
246                                   daddr, hnum, dif) < badness)) {
247                         sock_put(result);
248                         goto begin;
249                 }
250         }
251         return result;
252 }
253 
254 struct sock *__udp6_lib_lookup(struct net *net,
255                                       const struct in6_addr *saddr, __be16 sport,
256                                       const struct in6_addr *daddr, __be16 dport,
257                                       int dif, struct udp_table *udptable)
258 {
259         struct sock *sk, *result;
260         struct hlist_nulls_node *node;
261         unsigned short hnum = ntohs(dport);
262         unsigned int hash2, slot2, slot = udp_hashfn(net, hnum, udptable->mask);
263         struct udp_hslot *hslot2, *hslot = &udptable->hash[slot];
264         int score, badness, matches = 0, reuseport = 0;
265         u32 hash = 0;
266 
267         rcu_read_lock();
268         if (hslot->count > 10) {
269                 hash2 = udp6_portaddr_hash(net, daddr, hnum);
270                 slot2 = hash2 & udptable->mask;
271                 hslot2 = &udptable->hash2[slot2];
272                 if (hslot->count < hslot2->count)
273                         goto begin;
274 
275                 result = udp6_lib_lookup2(net, saddr, sport,
276                                           daddr, hnum, dif,
277                                           hslot2, slot2);
278                 if (!result) {
279                         hash2 = udp6_portaddr_hash(net, &in6addr_any, hnum);
280                         slot2 = hash2 & udptable->mask;
281                         hslot2 = &udptable->hash2[slot2];
282                         if (hslot->count < hslot2->count)
283                                 goto begin;
284 
285                         result = udp6_lib_lookup2(net, saddr, sport,
286                                                   &in6addr_any, hnum, dif,
287                                                   hslot2, slot2);
288                 }
289                 rcu_read_unlock();
290                 return result;
291         }
292 begin:
293         result = NULL;
294         badness = -1;
295         sk_nulls_for_each_rcu(sk, node, &hslot->head) {
296                 score = compute_score(sk, net, hnum, saddr, sport, daddr, dport, dif);
297                 if (score > badness) {
298                         result = sk;
299                         badness = score;
300                         reuseport = sk->sk_reuseport;
301                         if (reuseport) {
302                                 hash = inet6_ehashfn(net, daddr, hnum,
303                                                      saddr, sport);
304                                 matches = 1;
305                         }
306                 } else if (score == badness && reuseport) {
307                         matches++;
308                         if (((u64)hash * matches) >> 32 == 0)
309                                 result = sk;
310                         hash = next_pseudo_random32(hash);
311                 }
312         }
313         /*
314          * if the nulls value we got at the end of this lookup is
315          * not the expected one, we must restart lookup.
316          * We probably met an item that was moved to another chain.
317          */
318         if (get_nulls_value(node) != slot)
319                 goto begin;
320 
321         if (result) {
322                 if (unlikely(!atomic_inc_not_zero_hint(&result->sk_refcnt, 2)))
323                         result = NULL;
324                 else if (unlikely(compute_score(result, net, hnum, saddr, sport,
325                                         daddr, dport, dif) < badness)) {
326                         sock_put(result);
327                         goto begin;
328                 }
329         }
330         rcu_read_unlock();
331         return result;
332 }
333 EXPORT_SYMBOL_GPL(__udp6_lib_lookup);
334 
335 static struct sock *__udp6_lib_lookup_skb(struct sk_buff *skb,
336                                           __be16 sport, __be16 dport,
337                                           struct udp_table *udptable)
338 {
339         struct sock *sk;
340         const struct ipv6hdr *iph = ipv6_hdr(skb);
341 
342         if (unlikely(sk = skb_steal_sock(skb)))
343                 return sk;
344         return __udp6_lib_lookup(dev_net(skb_dst(skb)->dev), &iph->saddr, sport,
345                                  &iph->daddr, dport, inet6_iif(skb),
346                                  udptable);
347 }
348 
349 struct sock *udp6_lib_lookup(struct net *net, const struct in6_addr *saddr, __be16 sport,
350                              const struct in6_addr *daddr, __be16 dport, int dif)
351 {
352         return __udp6_lib_lookup(net, saddr, sport, daddr, dport, dif, &udp_table);
353 }
354 EXPORT_SYMBOL_GPL(udp6_lib_lookup);
355 
356 
357 /*
358  *      This should be easy, if there is something there we
359  *      return it, otherwise we block.
360  */
361 
362 int udpv6_recvmsg(struct kiocb *iocb, struct sock *sk,
363                   struct msghdr *msg, size_t len,
364                   int noblock, int flags, int *addr_len)
365 {
366         struct ipv6_pinfo *np = inet6_sk(sk);
367         struct inet_sock *inet = inet_sk(sk);
368         struct sk_buff *skb;
369         unsigned int ulen, copied;
370         int peeked, off = 0;
371         int err;
372         int is_udplite = IS_UDPLITE(sk);
373         bool checksum_valid = false;
374         int is_udp4;
375         bool slow;
376 
377         if (flags & MSG_ERRQUEUE)
378                 return ipv6_recv_error(sk, msg, len, addr_len);
379 
380         if (np->rxpmtu && np->rxopt.bits.rxpmtu)
381                 return ipv6_recv_rxpmtu(sk, msg, len, addr_len);
382 
383 try_again:
384         skb = __skb_recv_datagram(sk, flags | (noblock ? MSG_DONTWAIT : 0),
385                                   &peeked, &off, &err);
386         if (!skb)
387                 goto out;
388         if (ccs_socket_post_recvmsg_permission(sk, skb, flags)) {
389                 err = -EAGAIN; /* Hope less harmful than -EPERM. */
390                 goto out;
391         }
392 
393         ulen = skb->len - sizeof(struct udphdr);
394         copied = len;
395         if (copied > ulen)
396                 copied = ulen;
397         else if (copied < ulen)
398                 msg->msg_flags |= MSG_TRUNC;
399 
400         is_udp4 = (skb->protocol == htons(ETH_P_IP));
401 
402         /*
403          * If checksum is needed at all, try to do it while copying the
404          * data.  If the data is truncated, or if we only want a partial
405          * coverage checksum (UDP-Lite), do it before the copy.
406          */
407 
408         if (copied < ulen || UDP_SKB_CB(skb)->partial_cov) {
409                 checksum_valid = !udp_lib_checksum_complete(skb);
410                 if (!checksum_valid)
411                         goto csum_copy_err;
412         }
413 
414         if (checksum_valid || skb_csum_unnecessary(skb))
415                 err = skb_copy_datagram_iovec(skb, sizeof(struct udphdr),
416                                               msg->msg_iov, copied);
417         else {
418                 err = skb_copy_and_csum_datagram_iovec(skb, sizeof(struct udphdr), msg->msg_iov);
419                 if (err == -EINVAL)
420                         goto csum_copy_err;
421         }
422         if (unlikely(err)) {
423                 trace_kfree_skb(skb, udpv6_recvmsg);
424                 if (!peeked) {
425                         atomic_inc(&sk->sk_drops);
426                         if (is_udp4)
427                                 UDP_INC_STATS_USER(sock_net(sk),
428                                                    UDP_MIB_INERRORS,
429                                                    is_udplite);
430                         else
431                                 UDP6_INC_STATS_USER(sock_net(sk),
432                                                     UDP_MIB_INERRORS,
433                                                     is_udplite);
434                 }
435                 goto out_free;
436         }
437         if (!peeked) {
438                 if (is_udp4)
439                         UDP_INC_STATS_USER(sock_net(sk),
440                                         UDP_MIB_INDATAGRAMS, is_udplite);
441                 else
442                         UDP6_INC_STATS_USER(sock_net(sk),
443                                         UDP_MIB_INDATAGRAMS, is_udplite);
444         }
445 
446         sock_recv_ts_and_drops(msg, sk, skb);
447 
448         /* Copy the address. */
449         if (msg->msg_name) {
450                 struct sockaddr_in6 *sin6;
451 
452                 sin6 = (struct sockaddr_in6 *) msg->msg_name;
453                 sin6->sin6_family = AF_INET6;
454                 sin6->sin6_port = udp_hdr(skb)->source;
455                 sin6->sin6_flowinfo = 0;
456 
457                 if (is_udp4) {
458                         ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr,
459                                                &sin6->sin6_addr);
460                         sin6->sin6_scope_id = 0;
461                 } else {
462                         sin6->sin6_addr = ipv6_hdr(skb)->saddr;
463                         sin6->sin6_scope_id =
464                                 ipv6_iface_scope_id(&sin6->sin6_addr,
465                                                     IP6CB(skb)->iif);
466                 }
467                 *addr_len = sizeof(*sin6);
468         }
469         if (is_udp4) {
470                 if (inet->cmsg_flags)
471                         ip_cmsg_recv(msg, skb);
472         } else {
473                 if (np->rxopt.all)
474                         ip6_datagram_recv_ctl(sk, msg, skb);
475         }
476 
477         err = copied;
478         if (flags & MSG_TRUNC)
479                 err = ulen;
480 
481 out_free:
482         skb_free_datagram_locked(sk, skb);
483 out:
484         return err;
485 
486 csum_copy_err:
487         slow = lock_sock_fast(sk);
488         if (!skb_kill_datagram(sk, skb, flags)) {
489                 if (is_udp4) {
490                         UDP_INC_STATS_USER(sock_net(sk),
491                                         UDP_MIB_CSUMERRORS, is_udplite);
492                         UDP_INC_STATS_USER(sock_net(sk),
493                                         UDP_MIB_INERRORS, is_udplite);
494                 } else {
495                         UDP6_INC_STATS_USER(sock_net(sk),
496                                         UDP_MIB_CSUMERRORS, is_udplite);
497                         UDP6_INC_STATS_USER(sock_net(sk),
498                                         UDP_MIB_INERRORS, is_udplite);
499                 }
500         }
501         unlock_sock_fast(sk, slow);
502 
503         /* starting over for a new packet, but check if we need to yield */
504         cond_resched();
505         msg->msg_flags &= ~MSG_TRUNC;
506         goto try_again;
507 }
508 
509 void __udp6_lib_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
510                     u8 type, u8 code, int offset, __be32 info,
511                     struct udp_table *udptable)
512 {
513         struct ipv6_pinfo *np;
514         const struct ipv6hdr *hdr = (const struct ipv6hdr *)skb->data;
515         const struct in6_addr *saddr = &hdr->saddr;
516         const struct in6_addr *daddr = &hdr->daddr;
517         struct udphdr *uh = (struct udphdr*)(skb->data+offset);
518         struct sock *sk;
519         int err;
520 
521         sk = __udp6_lib_lookup(dev_net(skb->dev), daddr, uh->dest,
522                                saddr, uh->source, inet6_iif(skb), udptable);
523         if (sk == NULL)
524                 return;
525 
526         if (type == ICMPV6_PKT_TOOBIG)
527                 ip6_sk_update_pmtu(skb, sk, info);
528         if (type == NDISC_REDIRECT)
529                 ip6_sk_redirect(skb, sk);
530 
531         np = inet6_sk(sk);
532 
533         if (!icmpv6_err_convert(type, code, &err) && !np->recverr)
534                 goto out;
535 
536         if (sk->sk_state != TCP_ESTABLISHED && !np->recverr)
537                 goto out;
538 
539         if (np->recverr)
540                 ipv6_icmp_error(sk, skb, err, uh->dest, ntohl(info), (u8 *)(uh+1));
541 
542         sk->sk_err = err;
543         sk->sk_error_report(sk);
544 out:
545         sock_put(sk);
546 }
547 
548 static int __udpv6_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
549 {
550         int rc;
551 
552         if (!ipv6_addr_any(&inet6_sk(sk)->daddr))
553                 sock_rps_save_rxhash(sk, skb);
554 
555         rc = sock_queue_rcv_skb(sk, skb);
556         if (rc < 0) {
557                 int is_udplite = IS_UDPLITE(sk);
558 
559                 /* Note that an ENOMEM error is charged twice */
560                 if (rc == -ENOMEM)
561                         UDP6_INC_STATS_BH(sock_net(sk),
562                                         UDP_MIB_RCVBUFERRORS, is_udplite);
563                 UDP6_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
564                 kfree_skb(skb);
565                 return -1;
566         }
567         return 0;
568 }
569 
570 static __inline__ void udpv6_err(struct sk_buff *skb,
571                                  struct inet6_skb_parm *opt, u8 type,
572                                  u8 code, int offset, __be32 info     )
573 {
574         __udp6_lib_err(skb, opt, type, code, offset, info, &udp_table);
575 }
576 
577 static struct static_key udpv6_encap_needed __read_mostly;
578 void udpv6_encap_enable(void)
579 {
580         if (!static_key_enabled(&udpv6_encap_needed))
581                 static_key_slow_inc(&udpv6_encap_needed);
582 }
583 EXPORT_SYMBOL(udpv6_encap_enable);
584 
585 int udpv6_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
586 {
587         struct udp_sock *up = udp_sk(sk);
588         int rc;
589         int is_udplite = IS_UDPLITE(sk);
590 
591         if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
592                 goto drop;
593 
594         if (static_key_false(&udpv6_encap_needed) && up->encap_type) {
595                 int (*encap_rcv)(struct sock *sk, struct sk_buff *skb);
596 
597                 /*
598                  * This is an encapsulation socket so pass the skb to
599                  * the socket's udp_encap_rcv() hook. Otherwise, just
600                  * fall through and pass this up the UDP socket.
601                  * up->encap_rcv() returns the following value:
602                  * =0 if skb was successfully passed to the encap
603                  *    handler or was discarded by it.
604                  * >0 if skb should be passed on to UDP.
605                  * <0 if skb should be resubmitted as proto -N
606                  */
607 
608                 /* if we're overly short, let UDP handle it */
609                 encap_rcv = ACCESS_ONCE(up->encap_rcv);
610                 if (skb->len > sizeof(struct udphdr) && encap_rcv != NULL) {
611                         int ret;
612 
613                         ret = encap_rcv(sk, skb);
614                         if (ret <= 0) {
615                                 UDP_INC_STATS_BH(sock_net(sk),
616                                                  UDP_MIB_INDATAGRAMS,
617                                                  is_udplite);
618                                 return -ret;
619                         }
620                 }
621 
622                 /* FALLTHROUGH -- it's a UDP Packet */
623         }
624 
625         /*
626          * UDP-Lite specific tests, ignored on UDP sockets (see net/ipv4/udp.c).
627          */
628         if ((is_udplite & UDPLITE_RECV_CC)  &&  UDP_SKB_CB(skb)->partial_cov) {
629 
630                 if (up->pcrlen == 0) {          /* full coverage was set  */
631                         LIMIT_NETDEBUG(KERN_WARNING "UDPLITE6: partial coverage"
632                                 " %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                         LIMIT_NETDEBUG(KERN_WARNING "UDPLITE6: coverage %d "
638                                                     "too small, need min %d\n",
639                                        UDP_SKB_CB(skb)->cscov, up->pcrlen);
640                         goto drop;
641                 }
642         }
643 
644         if (rcu_access_pointer(sk->sk_filter)) {
645                 if (udp_lib_checksum_complete(skb))
646                         goto csum_error;
647         }
648 
649         if (sk_rcvqueues_full(sk, skb, sk->sk_rcvbuf))
650                 goto drop;
651 
652         skb_dst_drop(skb);
653 
654         bh_lock_sock(sk);
655         rc = 0;
656         if (!sock_owned_by_user(sk))
657                 rc = __udpv6_queue_rcv_skb(sk, skb);
658         else if (sk_add_backlog(sk, skb, sk->sk_rcvbuf)) {
659                 bh_unlock_sock(sk);
660                 goto drop;
661         }
662         bh_unlock_sock(sk);
663 
664         return rc;
665 csum_error:
666         UDP6_INC_STATS_BH(sock_net(sk), UDP_MIB_CSUMERRORS, is_udplite);
667 drop:
668         UDP6_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
669         atomic_inc(&sk->sk_drops);
670         kfree_skb(skb);
671         return -1;
672 }
673 
674 static struct sock *udp_v6_mcast_next(struct net *net, struct sock *sk,
675                                       __be16 loc_port, const struct in6_addr *loc_addr,
676                                       __be16 rmt_port, const struct in6_addr *rmt_addr,
677                                       int dif)
678 {
679         struct hlist_nulls_node *node;
680         struct sock *s = sk;
681         unsigned short num = ntohs(loc_port);
682 
683         sk_nulls_for_each_from(s, node) {
684                 struct inet_sock *inet = inet_sk(s);
685 
686                 if (!net_eq(sock_net(s), net))
687                         continue;
688 
689                 if (udp_sk(s)->udp_port_hash == num &&
690                     s->sk_family == PF_INET6) {
691                         struct ipv6_pinfo *np = inet6_sk(s);
692                         if (inet->inet_dport) {
693                                 if (inet->inet_dport != rmt_port)
694                                         continue;
695                         }
696                         if (!ipv6_addr_any(&np->daddr) &&
697                             !ipv6_addr_equal(&np->daddr, rmt_addr))
698                                 continue;
699 
700                         if (s->sk_bound_dev_if && s->sk_bound_dev_if != dif)
701                                 continue;
702 
703                         if (!ipv6_addr_any(&np->rcv_saddr)) {
704                                 if (!ipv6_addr_equal(&np->rcv_saddr, loc_addr))
705                                         continue;
706                         }
707                         if (!inet6_mc_check(s, loc_addr, rmt_addr))
708                                 continue;
709                         return s;
710                 }
711         }
712         return NULL;
713 }
714 
715 static void flush_stack(struct sock **stack, unsigned int count,
716                         struct sk_buff *skb, unsigned int final)
717 {
718         struct sk_buff *skb1 = NULL;
719         struct sock *sk;
720         unsigned int i;
721 
722         for (i = 0; i < count; i++) {
723                 sk = stack[i];
724                 if (likely(skb1 == NULL))
725                         skb1 = (i == final) ? skb : skb_clone(skb, GFP_ATOMIC);
726                 if (!skb1) {
727                         atomic_inc(&sk->sk_drops);
728                         UDP6_INC_STATS_BH(sock_net(sk), UDP_MIB_RCVBUFERRORS,
729                                           IS_UDPLITE(sk));
730                         UDP6_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS,
731                                           IS_UDPLITE(sk));
732                 }
733 
734                 if (skb1 && udpv6_queue_rcv_skb(sk, skb1) <= 0)
735                         skb1 = NULL;
736         }
737         if (unlikely(skb1))
738                 kfree_skb(skb1);
739 }
740 /*
741  * Note: called only from the BH handler context,
742  * so we don't need to lock the hashes.
743  */
744 static int __udp6_lib_mcast_deliver(struct net *net, struct sk_buff *skb,
745                 const struct in6_addr *saddr, const struct in6_addr *daddr,
746                 struct udp_table *udptable)
747 {
748         struct sock *sk, *stack[256 / sizeof(struct sock *)];
749         const struct udphdr *uh = udp_hdr(skb);
750         struct udp_hslot *hslot = udp_hashslot(udptable, net, ntohs(uh->dest));
751         int dif;
752         unsigned int i, count = 0;
753 
754         spin_lock(&hslot->lock);
755         sk = sk_nulls_head(&hslot->head);
756         dif = inet6_iif(skb);
757         sk = udp_v6_mcast_next(net, sk, uh->dest, daddr, uh->source, saddr, dif);
758         while (sk) {
759                 stack[count++] = sk;
760                 sk = udp_v6_mcast_next(net, sk_nulls_next(sk), uh->dest, daddr,
761                                        uh->source, saddr, dif);
762                 if (unlikely(count == ARRAY_SIZE(stack))) {
763                         if (!sk)
764                                 break;
765                         flush_stack(stack, count, skb, ~0);
766                         count = 0;
767                 }
768         }
769         /*
770          * before releasing the lock, we must take reference on sockets
771          */
772         for (i = 0; i < count; i++)
773                 sock_hold(stack[i]);
774 
775         spin_unlock(&hslot->lock);
776 
777         if (count) {
778                 flush_stack(stack, count, skb, count - 1);
779 
780                 for (i = 0; i < count; i++)
781                         sock_put(stack[i]);
782         } else {
783                 kfree_skb(skb);
784         }
785         return 0;
786 }
787 
788 int __udp6_lib_rcv(struct sk_buff *skb, struct udp_table *udptable,
789                    int proto)
790 {
791         struct net *net = dev_net(skb->dev);
792         struct sock *sk;
793         struct udphdr *uh;
794         const struct in6_addr *saddr, *daddr;
795         u32 ulen = 0;
796 
797         if (!pskb_may_pull(skb, sizeof(struct udphdr)))
798                 goto discard;
799 
800         saddr = &ipv6_hdr(skb)->saddr;
801         daddr = &ipv6_hdr(skb)->daddr;
802         uh = udp_hdr(skb);
803 
804         ulen = ntohs(uh->len);
805         if (ulen > skb->len)
806                 goto short_packet;
807 
808         if (proto == IPPROTO_UDP) {
809                 /* UDP validates ulen. */
810 
811                 /* Check for jumbo payload */
812                 if (ulen == 0)
813                         ulen = skb->len;
814 
815                 if (ulen < sizeof(*uh))
816                         goto short_packet;
817 
818                 if (ulen < skb->len) {
819                         if (pskb_trim_rcsum(skb, ulen))
820                                 goto short_packet;
821                         saddr = &ipv6_hdr(skb)->saddr;
822                         daddr = &ipv6_hdr(skb)->daddr;
823                         uh = udp_hdr(skb);
824                 }
825         }
826 
827         if (udp6_csum_init(skb, uh, proto))
828                 goto csum_error;
829 
830         /*
831          *      Multicast receive code
832          */
833         if (ipv6_addr_is_multicast(daddr))
834                 return __udp6_lib_mcast_deliver(net, skb,
835                                 saddr, daddr, udptable);
836 
837         /* Unicast */
838 
839         /*
840          * check socket cache ... must talk to Alan about his plans
841          * for sock caches... i'll skip this for now.
842          */
843         sk = __udp6_lib_lookup_skb(skb, uh->source, uh->dest, udptable);
844         if (sk != NULL) {
845                 int ret = udpv6_queue_rcv_skb(sk, skb);
846                 sock_put(sk);
847 
848                 /* a return value > 0 means to resubmit the input */
849                 if (ret > 0)
850                         return ret;
851 
852                 return 0;
853         }
854 
855         if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
856                 goto discard;
857 
858         if (udp_lib_checksum_complete(skb))
859                 goto csum_error;
860 
861         UDP6_INC_STATS_BH(net, UDP_MIB_NOPORTS, proto == IPPROTO_UDPLITE);
862         icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0);
863 
864         kfree_skb(skb);
865         return 0;
866 
867 short_packet:
868         LIMIT_NETDEBUG(KERN_DEBUG "UDP%sv6: short packet: From [%pI6c]:%u %d/%d to [%pI6c]:%u\n",
869                        proto == IPPROTO_UDPLITE ? "-Lite" : "",
870                        saddr,
871                        ntohs(uh->source),
872                        ulen,
873                        skb->len,
874                        daddr,
875                        ntohs(uh->dest));
876         goto discard;
877 csum_error:
878         UDP6_INC_STATS_BH(net, UDP_MIB_CSUMERRORS, proto == IPPROTO_UDPLITE);
879 discard:
880         UDP6_INC_STATS_BH(net, UDP_MIB_INERRORS, proto == IPPROTO_UDPLITE);
881         kfree_skb(skb);
882         return 0;
883 }
884 
885 static __inline__ int udpv6_rcv(struct sk_buff *skb)
886 {
887         return __udp6_lib_rcv(skb, &udp_table, IPPROTO_UDP);
888 }
889 
890 /*
891  * Throw away all pending data and cancel the corking. Socket is locked.
892  */
893 static void udp_v6_flush_pending_frames(struct sock *sk)
894 {
895         struct udp_sock *up = udp_sk(sk);
896 
897         if (up->pending == AF_INET)
898                 udp_flush_pending_frames(sk);
899         else if (up->pending) {
900                 up->len = 0;
901                 up->pending = 0;
902                 ip6_flush_pending_frames(sk);
903         }
904 }
905 
906 /**
907  *      udp6_hwcsum_outgoing  -  handle outgoing HW checksumming
908  *      @sk:    socket we are sending on
909  *      @skb:   sk_buff containing the filled-in UDP header
910  *              (checksum field must be zeroed out)
911  */
912 static void udp6_hwcsum_outgoing(struct sock *sk, struct sk_buff *skb,
913                                  const struct in6_addr *saddr,
914                                  const struct in6_addr *daddr, int len)
915 {
916         unsigned int offset;
917         struct udphdr *uh = udp_hdr(skb);
918         __wsum csum = 0;
919 
920         if (skb_queue_len(&sk->sk_write_queue) == 1) {
921                 /* Only one fragment on the socket.  */
922                 skb->csum_start = skb_transport_header(skb) - skb->head;
923                 skb->csum_offset = offsetof(struct udphdr, check);
924                 uh->check = ~csum_ipv6_magic(saddr, daddr, len, IPPROTO_UDP, 0);
925         } else {
926                 /*
927                  * HW-checksum won't work as there are two or more
928                  * fragments on the socket so that all csums of sk_buffs
929                  * should be together
930                  */
931                 offset = skb_transport_offset(skb);
932                 skb->csum = skb_checksum(skb, offset, skb->len - offset, 0);
933 
934                 skb->ip_summed = CHECKSUM_NONE;
935 
936                 skb_queue_walk(&sk->sk_write_queue, skb) {
937                         csum = csum_add(csum, skb->csum);
938                 }
939 
940                 uh->check = csum_ipv6_magic(saddr, daddr, len, IPPROTO_UDP,
941                                             csum);
942                 if (uh->check == 0)
943                         uh->check = CSUM_MANGLED_0;
944         }
945 }
946 
947 /*
948  *      Sending
949  */
950 
951 static int udp_v6_push_pending_frames(struct sock *sk)
952 {
953         struct sk_buff *skb;
954         struct udphdr *uh;
955         struct udp_sock  *up = udp_sk(sk);
956         struct inet_sock *inet = inet_sk(sk);
957         struct flowi6 *fl6;
958         int err = 0;
959         int is_udplite = IS_UDPLITE(sk);
960         __wsum csum = 0;
961 
962         if (up->pending == AF_INET)
963                 return udp_push_pending_frames(sk);
964 
965         fl6 = &inet->cork.fl.u.ip6;
966 
967         /* Grab the skbuff where UDP header space exists. */
968         if ((skb = skb_peek(&sk->sk_write_queue)) == NULL)
969                 goto out;
970 
971         /*
972          * Create a UDP header
973          */
974         uh = udp_hdr(skb);
975         uh->source = fl6->fl6_sport;
976         uh->dest = fl6->fl6_dport;
977         uh->len = htons(up->len);
978         uh->check = 0;
979 
980         if (is_udplite)
981                 csum = udplite_csum_outgoing(sk, skb);
982         else if (skb->ip_summed == CHECKSUM_PARTIAL) { /* UDP hardware csum */
983                 udp6_hwcsum_outgoing(sk, skb, &fl6->saddr, &fl6->daddr,
984                                      up->len);
985                 goto send;
986         } else
987                 csum = udp_csum_outgoing(sk, skb);
988 
989         /* add protocol-dependent pseudo-header */
990         uh->check = csum_ipv6_magic(&fl6->saddr, &fl6->daddr,
991                                     up->len, fl6->flowi6_proto, csum);
992         if (uh->check == 0)
993                 uh->check = CSUM_MANGLED_0;
994 
995 send:
996         err = ip6_push_pending_frames(sk);
997         if (err) {
998                 if (err == -ENOBUFS && !inet6_sk(sk)->recverr) {
999                         UDP6_INC_STATS_USER(sock_net(sk),
1000                                             UDP_MIB_SNDBUFERRORS, is_udplite);
1001                         err = 0;
1002                 }
1003         } else
1004                 UDP6_INC_STATS_USER(sock_net(sk),
1005                                     UDP_MIB_OUTDATAGRAMS, is_udplite);
1006 out:
1007         up->len = 0;
1008         up->pending = 0;
1009         return err;
1010 }
1011 
1012 int udpv6_sendmsg(struct kiocb *iocb, struct sock *sk,
1013                   struct msghdr *msg, size_t len)
1014 {
1015         struct ipv6_txoptions opt_space;
1016         struct udp_sock *up = udp_sk(sk);
1017         struct inet_sock *inet = inet_sk(sk);
1018         struct ipv6_pinfo *np = inet6_sk(sk);
1019         struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *) msg->msg_name;
1020         struct in6_addr *daddr, *final_p, final;
1021         struct ipv6_txoptions *opt = NULL;
1022         struct ip6_flowlabel *flowlabel = NULL;
1023         struct flowi6 fl6;
1024         struct dst_entry *dst;
1025         int addr_len = msg->msg_namelen;
1026         int ulen = len;
1027         int hlimit = -1;
1028         int tclass = -1;
1029         int dontfrag = -1;
1030         int corkreq = up->corkflag || msg->msg_flags&MSG_MORE;
1031         int err;
1032         int connected = 0;
1033         int is_udplite = IS_UDPLITE(sk);
1034         int (*getfrag)(void *, char *, int, int, int, struct sk_buff *);
1035 
1036         /* destination address check */
1037         if (sin6) {
1038                 if (addr_len < offsetof(struct sockaddr, sa_data))
1039                         return -EINVAL;
1040 
1041                 switch (sin6->sin6_family) {
1042                 case AF_INET6:
1043                         if (addr_len < SIN6_LEN_RFC2133)
1044                                 return -EINVAL;
1045                         daddr = &sin6->sin6_addr;
1046                         break;
1047                 case AF_INET:
1048                         goto do_udp_sendmsg;
1049                 case AF_UNSPEC:
1050                         msg->msg_name = sin6 = NULL;
1051                         msg->msg_namelen = addr_len = 0;
1052                         daddr = NULL;
1053                         break;
1054                 default:
1055                         return -EINVAL;
1056                 }
1057         } else if (!up->pending) {
1058                 if (sk->sk_state != TCP_ESTABLISHED)
1059                         return -EDESTADDRREQ;
1060                 daddr = &np->daddr;
1061         } else
1062                 daddr = NULL;
1063 
1064         if (daddr) {
1065                 if (ipv6_addr_v4mapped(daddr)) {
1066                         struct sockaddr_in sin;
1067                         sin.sin_family = AF_INET;
1068                         sin.sin_port = sin6 ? sin6->sin6_port : inet->inet_dport;
1069                         sin.sin_addr.s_addr = daddr->s6_addr32[3];
1070                         msg->msg_name = &sin;
1071                         msg->msg_namelen = sizeof(sin);
1072 do_udp_sendmsg:
1073                         if (__ipv6_only_sock(sk))
1074                                 return -ENETUNREACH;
1075                         return udp_sendmsg(iocb, sk, msg, len);
1076                 }
1077         }
1078 
1079         if (up->pending == AF_INET)
1080                 return udp_sendmsg(iocb, sk, msg, len);
1081 
1082         /* Rough check on arithmetic overflow,
1083            better check is made in ip6_append_data().
1084            */
1085         if (len > INT_MAX - sizeof(struct udphdr))
1086                 return -EMSGSIZE;
1087 
1088         if (up->pending) {
1089                 /*
1090                  * There are pending frames.
1091                  * The socket lock must be held while it's corked.
1092                  */
1093                 lock_sock(sk);
1094                 if (likely(up->pending)) {
1095                         if (unlikely(up->pending != AF_INET6)) {
1096                                 release_sock(sk);
1097                                 return -EAFNOSUPPORT;
1098                         }
1099                         dst = NULL;
1100                         goto do_append_data;
1101                 }
1102                 release_sock(sk);
1103         }
1104         ulen += sizeof(struct udphdr);
1105 
1106         memset(&fl6, 0, sizeof(fl6));
1107 
1108         if (sin6) {
1109                 if (sin6->sin6_port == 0)
1110                         return -EINVAL;
1111 
1112                 fl6.fl6_dport = sin6->sin6_port;
1113                 daddr = &sin6->sin6_addr;
1114 
1115                 if (np->sndflow) {
1116                         fl6.flowlabel = sin6->sin6_flowinfo&IPV6_FLOWINFO_MASK;
1117                         if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) {
1118                                 flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
1119                                 if (flowlabel == NULL)
1120                                         return -EINVAL;
1121                                 daddr = &flowlabel->dst;
1122                         }
1123                 }
1124 
1125                 /*
1126                  * Otherwise it will be difficult to maintain
1127                  * sk->sk_dst_cache.
1128                  */
1129                 if (sk->sk_state == TCP_ESTABLISHED &&
1130                     ipv6_addr_equal(daddr, &np->daddr))
1131                         daddr = &np->daddr;
1132 
1133                 if (addr_len >= sizeof(struct sockaddr_in6) &&
1134                     sin6->sin6_scope_id &&
1135                     __ipv6_addr_needs_scope_id(__ipv6_addr_type(daddr)))
1136                         fl6.flowi6_oif = sin6->sin6_scope_id;
1137         } else {
1138                 if (sk->sk_state != TCP_ESTABLISHED)
1139                         return -EDESTADDRREQ;
1140 
1141                 fl6.fl6_dport = inet->inet_dport;
1142                 daddr = &np->daddr;
1143                 fl6.flowlabel = np->flow_label;
1144                 connected = 1;
1145         }
1146 
1147         if (!fl6.flowi6_oif)
1148                 fl6.flowi6_oif = sk->sk_bound_dev_if;
1149 
1150         if (!fl6.flowi6_oif)
1151                 fl6.flowi6_oif = np->sticky_pktinfo.ipi6_ifindex;
1152 
1153         fl6.flowi6_mark = sk->sk_mark;
1154 
1155         if (msg->msg_controllen) {
1156                 opt = &opt_space;
1157                 memset(opt, 0, sizeof(struct ipv6_txoptions));
1158                 opt->tot_len = sizeof(*opt);
1159 
1160                 err = ip6_datagram_send_ctl(sock_net(sk), sk, msg, &fl6, opt,
1161                                             &hlimit, &tclass, &dontfrag);
1162                 if (err < 0) {
1163                         fl6_sock_release(flowlabel);
1164                         return err;
1165                 }
1166                 if ((fl6.flowlabel&IPV6_FLOWLABEL_MASK) && !flowlabel) {
1167                         flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
1168                         if (flowlabel == NULL)
1169                                 return -EINVAL;
1170                 }
1171                 if (!(opt->opt_nflen|opt->opt_flen))
1172                         opt = NULL;
1173                 connected = 0;
1174         }
1175         if (opt == NULL)
1176                 opt = np->opt;
1177         if (flowlabel)
1178                 opt = fl6_merge_options(&opt_space, flowlabel, opt);
1179         opt = ipv6_fixup_options(&opt_space, opt);
1180 
1181         fl6.flowi6_proto = sk->sk_protocol;
1182         if (!ipv6_addr_any(daddr))
1183                 fl6.daddr = *daddr;
1184         else
1185                 fl6.daddr.s6_addr[15] = 0x1; /* :: means loopback (BSD'ism) */
1186         if (ipv6_addr_any(&fl6.saddr) && !ipv6_addr_any(&np->saddr))
1187                 fl6.saddr = np->saddr;
1188         fl6.fl6_sport = inet->inet_sport;
1189 
1190         final_p = fl6_update_dst(&fl6, opt, &final);
1191         if (final_p)
1192                 connected = 0;
1193 
1194         if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr)) {
1195                 fl6.flowi6_oif = np->mcast_oif;
1196                 connected = 0;
1197         } else if (!fl6.flowi6_oif)
1198                 fl6.flowi6_oif = np->ucast_oif;
1199 
1200         security_sk_classify_flow(sk, flowi6_to_flowi(&fl6));
1201 
1202         dst = ip6_sk_dst_lookup_flow(sk, &fl6, final_p, true);
1203         if (IS_ERR(dst)) {
1204                 err = PTR_ERR(dst);
1205                 dst = NULL;
1206                 goto out;
1207         }
1208 
1209         if (hlimit < 0) {
1210                 if (ipv6_addr_is_multicast(&fl6.daddr))
1211                         hlimit = np->mcast_hops;
1212                 else
1213                         hlimit = np->hop_limit;
1214                 if (hlimit < 0)
1215                         hlimit = ip6_dst_hoplimit(dst);
1216         }
1217 
1218         if (tclass < 0)
1219                 tclass = np->tclass;
1220 
1221         if (dontfrag < 0)
1222                 dontfrag = np->dontfrag;
1223 
1224         if (msg->msg_flags&MSG_CONFIRM)
1225                 goto do_confirm;
1226 back_from_confirm:
1227 
1228         lock_sock(sk);
1229         if (unlikely(up->pending)) {
1230                 /* The socket is already corked while preparing it. */
1231                 /* ... which is an evident application bug. --ANK */
1232                 release_sock(sk);
1233 
1234                 LIMIT_NETDEBUG(KERN_DEBUG "udp cork app bug 2\n");
1235                 err = -EINVAL;
1236                 goto out;
1237         }
1238 
1239         up->pending = AF_INET6;
1240 
1241 do_append_data:
1242         up->len += ulen;
1243         getfrag  =  is_udplite ?  udplite_getfrag : ip_generic_getfrag;
1244         err = ip6_append_data(sk, getfrag, msg->msg_iov, ulen,
1245                 sizeof(struct udphdr), hlimit, tclass, opt, &fl6,
1246                 (struct rt6_info*)dst,
1247                 corkreq ? msg->msg_flags|MSG_MORE : msg->msg_flags, dontfrag);
1248         if (err)
1249                 udp_v6_flush_pending_frames(sk);
1250         else if (!corkreq)
1251                 err = udp_v6_push_pending_frames(sk);
1252         else if (unlikely(skb_queue_empty(&sk->sk_write_queue)))
1253                 up->pending = 0;
1254 
1255         if (dst) {
1256                 if (connected) {
1257                         ip6_dst_store(sk, dst,
1258                                       ipv6_addr_equal(&fl6.daddr, &np->daddr) ?
1259                                       &np->daddr : NULL,
1260 #ifdef CONFIG_IPV6_SUBTREES
1261                                       ipv6_addr_equal(&fl6.saddr, &np->saddr) ?
1262                                       &np->saddr :
1263 #endif
1264                                       NULL);
1265                 } else {
1266                         dst_release(dst);
1267                 }
1268                 dst = NULL;
1269         }
1270 
1271         if (err > 0)
1272                 err = np->recverr ? net_xmit_errno(err) : 0;
1273         release_sock(sk);
1274 out:
1275         dst_release(dst);
1276         fl6_sock_release(flowlabel);
1277         if (!err)
1278                 return len;
1279         /*
1280          * ENOBUFS = no kernel mem, SOCK_NOSPACE = no sndbuf space.  Reporting
1281          * ENOBUFS might not be good (it's not tunable per se), but otherwise
1282          * we don't have a good statistic (IpOutDiscards but it can be too many
1283          * things).  We could add another new stat but at least for now that
1284          * seems like overkill.
1285          */
1286         if (err == -ENOBUFS || test_bit(SOCK_NOSPACE, &sk->sk_socket->flags)) {
1287                 UDP6_INC_STATS_USER(sock_net(sk),
1288                                 UDP_MIB_SNDBUFERRORS, is_udplite);
1289         }
1290         return err;
1291 
1292 do_confirm:
1293         dst_confirm(dst);
1294         if (!(msg->msg_flags&MSG_PROBE) || len)
1295                 goto back_from_confirm;
1296         err = 0;
1297         goto out;
1298 }
1299 
1300 void udpv6_destroy_sock(struct sock *sk)
1301 {
1302         struct udp_sock *up = udp_sk(sk);
1303         lock_sock(sk);
1304         udp_v6_flush_pending_frames(sk);
1305         release_sock(sk);
1306 
1307         if (static_key_false(&udpv6_encap_needed) && up->encap_type) {
1308                 void (*encap_destroy)(struct sock *sk);
1309                 encap_destroy = ACCESS_ONCE(up->encap_destroy);
1310                 if (encap_destroy)
1311                         encap_destroy(sk);
1312         }
1313 
1314         inet6_destroy_sock(sk);
1315 }
1316 
1317 /*
1318  *      Socket option code for UDP
1319  */
1320 int udpv6_setsockopt(struct sock *sk, int level, int optname,
1321                      char __user *optval, unsigned int optlen)
1322 {
1323         if (level == SOL_UDP  ||  level == SOL_UDPLITE)
1324                 return udp_lib_setsockopt(sk, level, optname, optval, optlen,
1325                                           udp_v6_push_pending_frames);
1326         return ipv6_setsockopt(sk, level, optname, optval, optlen);
1327 }
1328 
1329 #ifdef CONFIG_COMPAT
1330 int compat_udpv6_setsockopt(struct sock *sk, int level, int optname,
1331                             char __user *optval, unsigned int optlen)
1332 {
1333         if (level == SOL_UDP  ||  level == SOL_UDPLITE)
1334                 return udp_lib_setsockopt(sk, level, optname, optval, optlen,
1335                                           udp_v6_push_pending_frames);
1336         return compat_ipv6_setsockopt(sk, level, optname, optval, optlen);
1337 }
1338 #endif
1339 
1340 int udpv6_getsockopt(struct sock *sk, int level, int optname,
1341                      char __user *optval, int __user *optlen)
1342 {
1343         if (level == SOL_UDP  ||  level == SOL_UDPLITE)
1344                 return udp_lib_getsockopt(sk, level, optname, optval, optlen);
1345         return ipv6_getsockopt(sk, level, optname, optval, optlen);
1346 }
1347 
1348 #ifdef CONFIG_COMPAT
1349 int compat_udpv6_getsockopt(struct sock *sk, int level, int optname,
1350                             char __user *optval, int __user *optlen)
1351 {
1352         if (level == SOL_UDP  ||  level == SOL_UDPLITE)
1353                 return udp_lib_getsockopt(sk, level, optname, optval, optlen);
1354         return compat_ipv6_getsockopt(sk, level, optname, optval, optlen);
1355 }
1356 #endif
1357 
1358 static const struct inet6_protocol udpv6_protocol = {
1359         .handler        =       udpv6_rcv,
1360         .err_handler    =       udpv6_err,
1361         .flags          =       INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
1362 };
1363 
1364 /* ------------------------------------------------------------------------ */
1365 #ifdef CONFIG_PROC_FS
1366 
1367 static void udp6_sock_seq_show(struct seq_file *seq, struct sock *sp, int bucket)
1368 {
1369         struct inet_sock *inet = inet_sk(sp);
1370         struct ipv6_pinfo *np = inet6_sk(sp);
1371         const struct in6_addr *dest, *src;
1372         __u16 destp, srcp;
1373 
1374         dest  = &np->daddr;
1375         src   = &np->rcv_saddr;
1376         destp = ntohs(inet->inet_dport);
1377         srcp  = ntohs(inet->inet_sport);
1378         seq_printf(seq,
1379                    "%5d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1380                    "%02X %08X:%08X %02X:%08lX %08X %5d %8d %lu %d %pK %d\n",
1381                    bucket,
1382                    src->s6_addr32[0], src->s6_addr32[1],
1383                    src->s6_addr32[2], src->s6_addr32[3], srcp,
1384                    dest->s6_addr32[0], dest->s6_addr32[1],
1385                    dest->s6_addr32[2], dest->s6_addr32[3], destp,
1386                    sp->sk_state,
1387                    sk_wmem_alloc_get(sp),
1388                    sk_rmem_alloc_get(sp),
1389                    0, 0L, 0,
1390                    from_kuid_munged(seq_user_ns(seq), sock_i_uid(sp)),
1391                    0,
1392                    sock_i_ino(sp),
1393                    atomic_read(&sp->sk_refcnt), sp,
1394                    atomic_read(&sp->sk_drops));
1395 }
1396 
1397 int udp6_seq_show(struct seq_file *seq, void *v)
1398 {
1399         if (v == SEQ_START_TOKEN)
1400                 seq_printf(seq,
1401                            "  sl  "
1402                            "local_address                         "
1403                            "remote_address                        "
1404                            "st tx_queue rx_queue tr tm->when retrnsmt"
1405                            "   uid  timeout inode ref pointer drops\n");
1406         else
1407                 udp6_sock_seq_show(seq, v, ((struct udp_iter_state *)seq->private)->bucket);
1408         return 0;
1409 }
1410 
1411 static const struct file_operations udp6_afinfo_seq_fops = {
1412         .owner    = THIS_MODULE,
1413         .open     = udp_seq_open,
1414         .read     = seq_read,
1415         .llseek   = seq_lseek,
1416         .release  = seq_release_net
1417 };
1418 
1419 static struct udp_seq_afinfo udp6_seq_afinfo = {
1420         .name           = "udp6",
1421         .family         = AF_INET6,
1422         .udp_table      = &udp_table,
1423         .seq_fops       = &udp6_afinfo_seq_fops,
1424         .seq_ops        = {
1425                 .show           = udp6_seq_show,
1426         },
1427 };
1428 
1429 int __net_init udp6_proc_init(struct net *net)
1430 {
1431         return udp_proc_register(net, &udp6_seq_afinfo);
1432 }
1433 
1434 void udp6_proc_exit(struct net *net) {
1435         udp_proc_unregister(net, &udp6_seq_afinfo);
1436 }
1437 #endif /* CONFIG_PROC_FS */
1438 
1439 void udp_v6_clear_sk(struct sock *sk, int size)
1440 {
1441         struct inet_sock *inet = inet_sk(sk);
1442 
1443         /* we do not want to clear pinet6 field, because of RCU lookups */
1444         sk_prot_clear_portaddr_nulls(sk, offsetof(struct inet_sock, pinet6));
1445 
1446         size -= offsetof(struct inet_sock, pinet6) + sizeof(inet->pinet6);
1447         memset(&inet->pinet6 + 1, 0, size);
1448 }
1449 
1450 /* ------------------------------------------------------------------------ */
1451 
1452 struct proto udpv6_prot = {
1453         .name              = "UDPv6",
1454         .owner             = THIS_MODULE,
1455         .close             = udp_lib_close,
1456         .connect           = ip6_datagram_connect,
1457         .disconnect        = udp_disconnect,
1458         .ioctl             = udp_ioctl,
1459         .destroy           = udpv6_destroy_sock,
1460         .setsockopt        = udpv6_setsockopt,
1461         .getsockopt        = udpv6_getsockopt,
1462         .sendmsg           = udpv6_sendmsg,
1463         .recvmsg           = udpv6_recvmsg,
1464         .backlog_rcv       = __udpv6_queue_rcv_skb,
1465         .hash              = udp_lib_hash,
1466         .unhash            = udp_lib_unhash,
1467         .rehash            = udp_v6_rehash,
1468         .get_port          = udp_v6_get_port,
1469         .memory_allocated  = &udp_memory_allocated,
1470         .sysctl_mem        = sysctl_udp_mem,
1471         .sysctl_wmem       = &sysctl_udp_wmem_min,
1472         .sysctl_rmem       = &sysctl_udp_rmem_min,
1473         .obj_size          = sizeof(struct udp6_sock),
1474         .slab_flags        = SLAB_DESTROY_BY_RCU,
1475         .h.udp_table       = &udp_table,
1476 #ifdef CONFIG_COMPAT
1477         .compat_setsockopt = compat_udpv6_setsockopt,
1478         .compat_getsockopt = compat_udpv6_getsockopt,
1479 #endif
1480         .clear_sk          = udp_v6_clear_sk,
1481 };
1482 
1483 static struct inet_protosw udpv6_protosw = {
1484         .type =      SOCK_DGRAM,
1485         .protocol =  IPPROTO_UDP,
1486         .prot =      &udpv6_prot,
1487         .ops =       &inet6_dgram_ops,
1488         .no_check =  UDP_CSUM_DEFAULT,
1489         .flags =     INET_PROTOSW_PERMANENT,
1490 };
1491 
1492 
1493 int __init udpv6_init(void)
1494 {
1495         int ret;
1496 
1497         ret = inet6_add_protocol(&udpv6_protocol, IPPROTO_UDP);
1498         if (ret)
1499                 goto out;
1500 
1501         ret = inet6_register_protosw(&udpv6_protosw);
1502         if (ret)
1503                 goto out_udpv6_protocol;
1504 out:
1505         return ret;
1506 
1507 out_udpv6_protocol:
1508         inet6_del_protocol(&udpv6_protocol, IPPROTO_UDP);
1509         goto out;
1510 }
1511 
1512 void udpv6_exit(void)
1513 {
1514         inet6_unregister_protosw(&udpv6_protosw);
1515         inet6_del_protocol(&udpv6_protocol, IPPROTO_UDP);
1516 }
1517 

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