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udp.c
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1 /*
2  * UDP over IPv6
3  * Linux INET6 implementation
4  *
5  * Authors:
6  * Pedro Roque <[email protected]>
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 
49 #include <linux/proc_fs.h>
50 #include <linux/seq_file.h>
51 #include <trace/events/skb.h>
52 #include "udp_impl.h"
53 
54 int ipv6_rcv_saddr_equal(const struct sock *sk, const struct sock *sk2)
55 {
56  const struct in6_addr *sk_rcv_saddr6 = &inet6_sk(sk)->rcv_saddr;
57  const struct in6_addr *sk2_rcv_saddr6 = inet6_rcv_saddr(sk2);
58  __be32 sk1_rcv_saddr = sk_rcv_saddr(sk);
59  __be32 sk2_rcv_saddr = sk_rcv_saddr(sk2);
60  int sk_ipv6only = ipv6_only_sock(sk);
61  int sk2_ipv6only = inet_v6_ipv6only(sk2);
62  int addr_type = ipv6_addr_type(sk_rcv_saddr6);
63  int addr_type2 = sk2_rcv_saddr6 ? ipv6_addr_type(sk2_rcv_saddr6) : IPV6_ADDR_MAPPED;
64 
65  /* if both are mapped, treat as IPv4 */
66  if (addr_type == IPV6_ADDR_MAPPED && addr_type2 == IPV6_ADDR_MAPPED)
67  return (!sk2_ipv6only &&
68  (!sk1_rcv_saddr || !sk2_rcv_saddr ||
69  sk1_rcv_saddr == sk2_rcv_saddr));
70 
71  if (addr_type2 == IPV6_ADDR_ANY &&
72  !(sk2_ipv6only && addr_type == IPV6_ADDR_MAPPED))
73  return 1;
74 
75  if (addr_type == IPV6_ADDR_ANY &&
76  !(sk_ipv6only && addr_type2 == IPV6_ADDR_MAPPED))
77  return 1;
78 
79  if (sk2_rcv_saddr6 &&
80  ipv6_addr_equal(sk_rcv_saddr6, sk2_rcv_saddr6))
81  return 1;
82 
83  return 0;
84 }
85 
86 static unsigned int udp6_portaddr_hash(struct net *net,
87  const struct in6_addr *addr6,
88  unsigned int port)
89 {
90  unsigned int hash, mix = net_hash_mix(net);
91 
92  if (ipv6_addr_any(addr6))
93  hash = jhash_1word(0, mix);
94  else if (ipv6_addr_v4mapped(addr6))
95  hash = jhash_1word((__force u32)addr6->s6_addr32[3], mix);
96  else
97  hash = jhash2((__force u32 *)addr6->s6_addr32, 4, mix);
98 
99  return hash ^ port;
100 }
101 
102 
103 int udp_v6_get_port(struct sock *sk, unsigned short snum)
104 {
105  unsigned int hash2_nulladdr =
106  udp6_portaddr_hash(sock_net(sk), &in6addr_any, snum);
107  unsigned int hash2_partial =
108  udp6_portaddr_hash(sock_net(sk), &inet6_sk(sk)->rcv_saddr, 0);
109 
110  /* precompute partial secondary hash */
111  udp_sk(sk)->udp_portaddr_hash = hash2_partial;
112  return udp_lib_get_port(sk, snum, ipv6_rcv_saddr_equal, hash2_nulladdr);
113 }
114 
115 static void udp_v6_rehash(struct sock *sk)
116 {
117  u16 new_hash = udp6_portaddr_hash(sock_net(sk),
118  &inet6_sk(sk)->rcv_saddr,
119  inet_sk(sk)->inet_num);
120 
121  udp_lib_rehash(sk, new_hash);
122 }
123 
124 static inline int compute_score(struct sock *sk, struct net *net,
125  unsigned short hnum,
126  const struct in6_addr *saddr, __be16 sport,
127  const struct in6_addr *daddr, __be16 dport,
128  int dif)
129 {
130  int score = -1;
131 
132  if (net_eq(sock_net(sk), net) && udp_sk(sk)->udp_port_hash == hnum &&
133  sk->sk_family == PF_INET6) {
134  struct ipv6_pinfo *np = inet6_sk(sk);
135  struct inet_sock *inet = inet_sk(sk);
136 
137  score = 0;
138  if (inet->inet_dport) {
139  if (inet->inet_dport != sport)
140  return -1;
141  score++;
142  }
143  if (!ipv6_addr_any(&np->rcv_saddr)) {
144  if (!ipv6_addr_equal(&np->rcv_saddr, daddr))
145  return -1;
146  score++;
147  }
148  if (!ipv6_addr_any(&np->daddr)) {
149  if (!ipv6_addr_equal(&np->daddr, saddr))
150  return -1;
151  score++;
152  }
153  if (sk->sk_bound_dev_if) {
154  if (sk->sk_bound_dev_if != dif)
155  return -1;
156  score++;
157  }
158  }
159  return score;
160 }
161 
162 #define SCORE2_MAX (1 + 1 + 1)
163 static inline int compute_score2(struct sock *sk, struct net *net,
164  const struct in6_addr *saddr, __be16 sport,
165  const struct in6_addr *daddr, unsigned short hnum,
166  int dif)
167 {
168  int score = -1;
169 
170  if (net_eq(sock_net(sk), net) && udp_sk(sk)->udp_port_hash == hnum &&
171  sk->sk_family == PF_INET6) {
172  struct ipv6_pinfo *np = inet6_sk(sk);
173  struct inet_sock *inet = inet_sk(sk);
174 
175  if (!ipv6_addr_equal(&np->rcv_saddr, daddr))
176  return -1;
177  score = 0;
178  if (inet->inet_dport) {
179  if (inet->inet_dport != sport)
180  return -1;
181  score++;
182  }
183  if (!ipv6_addr_any(&np->daddr)) {
184  if (!ipv6_addr_equal(&np->daddr, saddr))
185  return -1;
186  score++;
187  }
188  if (sk->sk_bound_dev_if) {
189  if (sk->sk_bound_dev_if != dif)
190  return -1;
191  score++;
192  }
193  }
194  return score;
195 }
196 
197 
198 /* called with read_rcu_lock() */
199 static struct sock *udp6_lib_lookup2(struct net *net,
200  const struct in6_addr *saddr, __be16 sport,
201  const struct in6_addr *daddr, unsigned int hnum, int dif,
202  struct udp_hslot *hslot2, unsigned int slot2)
203 {
204  struct sock *sk, *result;
205  struct hlist_nulls_node *node;
206  int score, badness;
207 
208 begin:
209  result = NULL;
210  badness = -1;
211  udp_portaddr_for_each_entry_rcu(sk, node, &hslot2->head) {
212  score = compute_score2(sk, net, saddr, sport,
213  daddr, hnum, dif);
214  if (score > badness) {
215  result = sk;
216  badness = score;
217  if (score == SCORE2_MAX)
218  goto exact_match;
219  }
220  }
221  /*
222  * if the nulls value we got at the end of this lookup is
223  * not the expected one, we must restart lookup.
224  * We probably met an item that was moved to another chain.
225  */
226  if (get_nulls_value(node) != slot2)
227  goto begin;
228 
229  if (result) {
230 exact_match:
231  if (unlikely(!atomic_inc_not_zero_hint(&result->sk_refcnt, 2)))
232  result = NULL;
233  else if (unlikely(compute_score2(result, net, saddr, sport,
234  daddr, hnum, dif) < badness)) {
235  sock_put(result);
236  goto begin;
237  }
238  }
239  return result;
240 }
241 
242 struct sock *__udp6_lib_lookup(struct net *net,
243  const struct in6_addr *saddr, __be16 sport,
244  const struct in6_addr *daddr, __be16 dport,
245  int dif, struct udp_table *udptable)
246 {
247  struct sock *sk, *result;
248  struct hlist_nulls_node *node;
249  unsigned short hnum = ntohs(dport);
250  unsigned int hash2, slot2, slot = udp_hashfn(net, hnum, udptable->mask);
251  struct udp_hslot *hslot2, *hslot = &udptable->hash[slot];
252  int score, badness;
253 
254  rcu_read_lock();
255  if (hslot->count > 10) {
256  hash2 = udp6_portaddr_hash(net, daddr, hnum);
257  slot2 = hash2 & udptable->mask;
258  hslot2 = &udptable->hash2[slot2];
259  if (hslot->count < hslot2->count)
260  goto begin;
261 
262  result = udp6_lib_lookup2(net, saddr, sport,
263  daddr, hnum, dif,
264  hslot2, slot2);
265  if (!result) {
266  hash2 = udp6_portaddr_hash(net, &in6addr_any, hnum);
267  slot2 = hash2 & udptable->mask;
268  hslot2 = &udptable->hash2[slot2];
269  if (hslot->count < hslot2->count)
270  goto begin;
271 
272  result = udp6_lib_lookup2(net, saddr, sport,
273  &in6addr_any, hnum, dif,
274  hslot2, slot2);
275  }
276  rcu_read_unlock();
277  return result;
278  }
279 begin:
280  result = NULL;
281  badness = -1;
282  sk_nulls_for_each_rcu(sk, node, &hslot->head) {
283  score = compute_score(sk, net, hnum, saddr, sport, daddr, dport, dif);
284  if (score > badness) {
285  result = sk;
286  badness = score;
287  }
288  }
289  /*
290  * if the nulls value we got at the end of this lookup is
291  * not the expected one, we must restart lookup.
292  * We probably met an item that was moved to another chain.
293  */
294  if (get_nulls_value(node) != slot)
295  goto begin;
296 
297  if (result) {
298  if (unlikely(!atomic_inc_not_zero_hint(&result->sk_refcnt, 2)))
299  result = NULL;
300  else if (unlikely(compute_score(result, net, hnum, saddr, sport,
301  daddr, dport, dif) < badness)) {
302  sock_put(result);
303  goto begin;
304  }
305  }
306  rcu_read_unlock();
307  return result;
308 }
309 EXPORT_SYMBOL_GPL(__udp6_lib_lookup);
310 
311 static struct sock *__udp6_lib_lookup_skb(struct sk_buff *skb,
312  __be16 sport, __be16 dport,
313  struct udp_table *udptable)
314 {
315  struct sock *sk;
316  const struct ipv6hdr *iph = ipv6_hdr(skb);
317 
318  if (unlikely(sk = skb_steal_sock(skb)))
319  return sk;
320  return __udp6_lib_lookup(dev_net(skb_dst(skb)->dev), &iph->saddr, sport,
321  &iph->daddr, dport, inet6_iif(skb),
322  udptable);
323 }
324 
325 struct sock *udp6_lib_lookup(struct net *net, const struct in6_addr *saddr, __be16 sport,
326  const struct in6_addr *daddr, __be16 dport, int dif)
327 {
328  return __udp6_lib_lookup(net, saddr, sport, daddr, dport, dif, &udp_table);
329 }
330 EXPORT_SYMBOL_GPL(udp6_lib_lookup);
331 
332 
333 /*
334  * This should be easy, if there is something there we
335  * return it, otherwise we block.
336  */
337 
338 int udpv6_recvmsg(struct kiocb *iocb, struct sock *sk,
339  struct msghdr *msg, size_t len,
340  int noblock, int flags, int *addr_len)
341 {
342  struct ipv6_pinfo *np = inet6_sk(sk);
343  struct inet_sock *inet = inet_sk(sk);
344  struct sk_buff *skb;
345  unsigned int ulen, copied;
346  int peeked, off = 0;
347  int err;
348  int is_udplite = IS_UDPLITE(sk);
349  int is_udp4;
350  bool slow;
351 
352  if (addr_len)
353  *addr_len = sizeof(struct sockaddr_in6);
354 
355  if (flags & MSG_ERRQUEUE)
356  return ipv6_recv_error(sk, msg, len);
357 
358  if (np->rxpmtu && np->rxopt.bits.rxpmtu)
359  return ipv6_recv_rxpmtu(sk, msg, len);
360 
361 try_again:
362  skb = __skb_recv_datagram(sk, flags | (noblock ? MSG_DONTWAIT : 0),
363  &peeked, &off, &err);
364  if (!skb)
365  goto out;
366 
367  ulen = skb->len - sizeof(struct udphdr);
368  copied = len;
369  if (copied > ulen)
370  copied = ulen;
371  else if (copied < ulen)
372  msg->msg_flags |= MSG_TRUNC;
373 
374  is_udp4 = (skb->protocol == htons(ETH_P_IP));
375 
376  /*
377  * If checksum is needed at all, try to do it while copying the
378  * data. If the data is truncated, or if we only want a partial
379  * coverage checksum (UDP-Lite), do it before the copy.
380  */
381 
382  if (copied < ulen || UDP_SKB_CB(skb)->partial_cov) {
383  if (udp_lib_checksum_complete(skb))
384  goto csum_copy_err;
385  }
386 
387  if (skb_csum_unnecessary(skb))
388  err = skb_copy_datagram_iovec(skb, sizeof(struct udphdr),
389  msg->msg_iov, copied);
390  else {
391  err = skb_copy_and_csum_datagram_iovec(skb, sizeof(struct udphdr), msg->msg_iov);
392  if (err == -EINVAL)
393  goto csum_copy_err;
394  }
395  if (unlikely(err)) {
396  trace_kfree_skb(skb, udpv6_recvmsg);
397  if (!peeked) {
398  atomic_inc(&sk->sk_drops);
399  if (is_udp4)
400  UDP_INC_STATS_USER(sock_net(sk),
401  UDP_MIB_INERRORS,
402  is_udplite);
403  else
404  UDP6_INC_STATS_USER(sock_net(sk),
405  UDP_MIB_INERRORS,
406  is_udplite);
407  }
408  goto out_free;
409  }
410  if (!peeked) {
411  if (is_udp4)
412  UDP_INC_STATS_USER(sock_net(sk),
413  UDP_MIB_INDATAGRAMS, is_udplite);
414  else
415  UDP6_INC_STATS_USER(sock_net(sk),
416  UDP_MIB_INDATAGRAMS, is_udplite);
417  }
418 
419  sock_recv_ts_and_drops(msg, sk, skb);
420 
421  /* Copy the address. */
422  if (msg->msg_name) {
423  struct sockaddr_in6 *sin6;
424 
425  sin6 = (struct sockaddr_in6 *) msg->msg_name;
426  sin6->sin6_family = AF_INET6;
427  sin6->sin6_port = udp_hdr(skb)->source;
428  sin6->sin6_flowinfo = 0;
429  sin6->sin6_scope_id = 0;
430 
431  if (is_udp4)
432  ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr,
433  &sin6->sin6_addr);
434  else {
435  sin6->sin6_addr = ipv6_hdr(skb)->saddr;
436  if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL)
437  sin6->sin6_scope_id = IP6CB(skb)->iif;
438  }
439 
440  }
441  if (is_udp4) {
442  if (inet->cmsg_flags)
443  ip_cmsg_recv(msg, skb);
444  } else {
445  if (np->rxopt.all)
446  datagram_recv_ctl(sk, msg, skb);
447  }
448 
449  err = copied;
450  if (flags & MSG_TRUNC)
451  err = ulen;
452 
453 out_free:
454  skb_free_datagram_locked(sk, skb);
455 out:
456  return err;
457 
458 csum_copy_err:
459  slow = lock_sock_fast(sk);
460  if (!skb_kill_datagram(sk, skb, flags)) {
461  if (is_udp4)
462  UDP_INC_STATS_USER(sock_net(sk),
463  UDP_MIB_INERRORS, is_udplite);
464  else
465  UDP6_INC_STATS_USER(sock_net(sk),
466  UDP_MIB_INERRORS, is_udplite);
467  }
468  unlock_sock_fast(sk, slow);
469 
470  if (noblock)
471  return -EAGAIN;
472 
473  /* starting over for a new packet */
474  msg->msg_flags &= ~MSG_TRUNC;
475  goto try_again;
476 }
477 
478 void __udp6_lib_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
479  u8 type, u8 code, int offset, __be32 info,
480  struct udp_table *udptable)
481 {
482  struct ipv6_pinfo *np;
483  const struct ipv6hdr *hdr = (const struct ipv6hdr *)skb->data;
484  const struct in6_addr *saddr = &hdr->saddr;
485  const struct in6_addr *daddr = &hdr->daddr;
486  struct udphdr *uh = (struct udphdr*)(skb->data+offset);
487  struct sock *sk;
488  int err;
489 
490  sk = __udp6_lib_lookup(dev_net(skb->dev), daddr, uh->dest,
491  saddr, uh->source, inet6_iif(skb), udptable);
492  if (sk == NULL)
493  return;
494 
495  if (type == ICMPV6_PKT_TOOBIG)
496  ip6_sk_update_pmtu(skb, sk, info);
497  if (type == NDISC_REDIRECT)
498  ip6_sk_redirect(skb, sk);
499 
500  np = inet6_sk(sk);
501 
502  if (!icmpv6_err_convert(type, code, &err) && !np->recverr)
503  goto out;
504 
505  if (sk->sk_state != TCP_ESTABLISHED && !np->recverr)
506  goto out;
507 
508  if (np->recverr)
509  ipv6_icmp_error(sk, skb, err, uh->dest, ntohl(info), (u8 *)(uh+1));
510 
511  sk->sk_err = err;
512  sk->sk_error_report(sk);
513 out:
514  sock_put(sk);
515 }
516 
517 static int __udpv6_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
518 {
519  int rc;
520 
521  if (!ipv6_addr_any(&inet6_sk(sk)->daddr))
522  sock_rps_save_rxhash(sk, skb);
523 
524  rc = sock_queue_rcv_skb(sk, skb);
525  if (rc < 0) {
526  int is_udplite = IS_UDPLITE(sk);
527 
528  /* Note that an ENOMEM error is charged twice */
529  if (rc == -ENOMEM)
530  UDP6_INC_STATS_BH(sock_net(sk),
531  UDP_MIB_RCVBUFERRORS, is_udplite);
532  UDP6_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
533  kfree_skb(skb);
534  return -1;
535  }
536  return 0;
537 }
538 
539 static __inline__ void udpv6_err(struct sk_buff *skb,
540  struct inet6_skb_parm *opt, u8 type,
541  u8 code, int offset, __be32 info )
542 {
543  __udp6_lib_err(skb, opt, type, code, offset, info, &udp_table);
544 }
545 
546 static struct static_key udpv6_encap_needed __read_mostly;
547 void udpv6_encap_enable(void)
548 {
549  if (!static_key_enabled(&udpv6_encap_needed))
550  static_key_slow_inc(&udpv6_encap_needed);
551 }
552 EXPORT_SYMBOL(udpv6_encap_enable);
553 
554 int udpv6_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
555 {
556  struct udp_sock *up = udp_sk(sk);
557  int rc;
558  int is_udplite = IS_UDPLITE(sk);
559 
560  if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
561  goto drop;
562 
563  if (static_key_false(&udpv6_encap_needed) && up->encap_type) {
564  int (*encap_rcv)(struct sock *sk, struct sk_buff *skb);
565 
566  /*
567  * This is an encapsulation socket so pass the skb to
568  * the socket's udp_encap_rcv() hook. Otherwise, just
569  * fall through and pass this up the UDP socket.
570  * up->encap_rcv() returns the following value:
571  * =0 if skb was successfully passed to the encap
572  * handler or was discarded by it.
573  * >0 if skb should be passed on to UDP.
574  * <0 if skb should be resubmitted as proto -N
575  */
576 
577  /* if we're overly short, let UDP handle it */
578  encap_rcv = ACCESS_ONCE(up->encap_rcv);
579  if (skb->len > sizeof(struct udphdr) && encap_rcv != NULL) {
580  int ret;
581 
582  ret = encap_rcv(sk, skb);
583  if (ret <= 0) {
584  UDP_INC_STATS_BH(sock_net(sk),
585  UDP_MIB_INDATAGRAMS,
586  is_udplite);
587  return -ret;
588  }
589  }
590 
591  /* FALLTHROUGH -- it's a UDP Packet */
592  }
593 
594  /*
595  * UDP-Lite specific tests, ignored on UDP sockets (see net/ipv4/udp.c).
596  */
597  if ((is_udplite & UDPLITE_RECV_CC) && UDP_SKB_CB(skb)->partial_cov) {
598 
599  if (up->pcrlen == 0) { /* full coverage was set */
600  LIMIT_NETDEBUG(KERN_WARNING "UDPLITE6: partial coverage"
601  " %d while full coverage %d requested\n",
602  UDP_SKB_CB(skb)->cscov, skb->len);
603  goto drop;
604  }
605  if (UDP_SKB_CB(skb)->cscov < up->pcrlen) {
606  LIMIT_NETDEBUG(KERN_WARNING "UDPLITE6: coverage %d "
607  "too small, need min %d\n",
608  UDP_SKB_CB(skb)->cscov, up->pcrlen);
609  goto drop;
610  }
611  }
612 
613  if (rcu_access_pointer(sk->sk_filter)) {
614  if (udp_lib_checksum_complete(skb))
615  goto drop;
616  }
617 
618  if (sk_rcvqueues_full(sk, skb, sk->sk_rcvbuf))
619  goto drop;
620 
621  skb_dst_drop(skb);
622 
623  bh_lock_sock(sk);
624  rc = 0;
625  if (!sock_owned_by_user(sk))
626  rc = __udpv6_queue_rcv_skb(sk, skb);
627  else if (sk_add_backlog(sk, skb, sk->sk_rcvbuf)) {
628  bh_unlock_sock(sk);
629  goto drop;
630  }
631  bh_unlock_sock(sk);
632 
633  return rc;
634 drop:
635  UDP6_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
636  atomic_inc(&sk->sk_drops);
637  kfree_skb(skb);
638  return -1;
639 }
640 
641 static struct sock *udp_v6_mcast_next(struct net *net, struct sock *sk,
642  __be16 loc_port, const struct in6_addr *loc_addr,
643  __be16 rmt_port, const struct in6_addr *rmt_addr,
644  int dif)
645 {
646  struct hlist_nulls_node *node;
647  struct sock *s = sk;
648  unsigned short num = ntohs(loc_port);
649 
650  sk_nulls_for_each_from(s, node) {
651  struct inet_sock *inet = inet_sk(s);
652 
653  if (!net_eq(sock_net(s), net))
654  continue;
655 
656  if (udp_sk(s)->udp_port_hash == num &&
657  s->sk_family == PF_INET6) {
658  struct ipv6_pinfo *np = inet6_sk(s);
659  if (inet->inet_dport) {
660  if (inet->inet_dport != rmt_port)
661  continue;
662  }
663  if (!ipv6_addr_any(&np->daddr) &&
664  !ipv6_addr_equal(&np->daddr, rmt_addr))
665  continue;
666 
667  if (s->sk_bound_dev_if && s->sk_bound_dev_if != dif)
668  continue;
669 
670  if (!ipv6_addr_any(&np->rcv_saddr)) {
671  if (!ipv6_addr_equal(&np->rcv_saddr, loc_addr))
672  continue;
673  }
674  if (!inet6_mc_check(s, loc_addr, rmt_addr))
675  continue;
676  return s;
677  }
678  }
679  return NULL;
680 }
681 
682 static void flush_stack(struct sock **stack, unsigned int count,
683  struct sk_buff *skb, unsigned int final)
684 {
685  struct sk_buff *skb1 = NULL;
686  struct sock *sk;
687  unsigned int i;
688 
689  for (i = 0; i < count; i++) {
690  sk = stack[i];
691  if (likely(skb1 == NULL))
692  skb1 = (i == final) ? skb : skb_clone(skb, GFP_ATOMIC);
693  if (!skb1) {
694  atomic_inc(&sk->sk_drops);
695  UDP6_INC_STATS_BH(sock_net(sk), UDP_MIB_RCVBUFERRORS,
696  IS_UDPLITE(sk));
697  UDP6_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS,
698  IS_UDPLITE(sk));
699  }
700 
701  if (skb1 && udpv6_queue_rcv_skb(sk, skb1) <= 0)
702  skb1 = NULL;
703  }
704  if (unlikely(skb1))
705  kfree_skb(skb1);
706 }
707 /*
708  * Note: called only from the BH handler context,
709  * so we don't need to lock the hashes.
710  */
711 static int __udp6_lib_mcast_deliver(struct net *net, struct sk_buff *skb,
712  const struct in6_addr *saddr, const struct in6_addr *daddr,
713  struct udp_table *udptable)
714 {
715  struct sock *sk, *stack[256 / sizeof(struct sock *)];
716  const struct udphdr *uh = udp_hdr(skb);
717  struct udp_hslot *hslot = udp_hashslot(udptable, net, ntohs(uh->dest));
718  int dif;
719  unsigned int i, count = 0;
720 
721  spin_lock(&hslot->lock);
722  sk = sk_nulls_head(&hslot->head);
723  dif = inet6_iif(skb);
724  sk = udp_v6_mcast_next(net, sk, uh->dest, daddr, uh->source, saddr, dif);
725  while (sk) {
726  stack[count++] = sk;
727  sk = udp_v6_mcast_next(net, sk_nulls_next(sk), uh->dest, daddr,
728  uh->source, saddr, dif);
729  if (unlikely(count == ARRAY_SIZE(stack))) {
730  if (!sk)
731  break;
732  flush_stack(stack, count, skb, ~0);
733  count = 0;
734  }
735  }
736  /*
737  * before releasing the lock, we must take reference on sockets
738  */
739  for (i = 0; i < count; i++)
740  sock_hold(stack[i]);
741 
742  spin_unlock(&hslot->lock);
743 
744  if (count) {
745  flush_stack(stack, count, skb, count - 1);
746 
747  for (i = 0; i < count; i++)
748  sock_put(stack[i]);
749  } else {
750  kfree_skb(skb);
751  }
752  return 0;
753 }
754 
755 static inline int udp6_csum_init(struct sk_buff *skb, struct udphdr *uh,
756  int proto)
757 {
758  int err;
759 
760  UDP_SKB_CB(skb)->partial_cov = 0;
761  UDP_SKB_CB(skb)->cscov = skb->len;
762 
763  if (proto == IPPROTO_UDPLITE) {
764  err = udplite_checksum_init(skb, uh);
765  if (err)
766  return err;
767  }
768 
769  if (uh->check == 0) {
770  /* RFC 2460 section 8.1 says that we SHOULD log
771  this error. Well, it is reasonable.
772  */
773  LIMIT_NETDEBUG(KERN_INFO "IPv6: udp checksum is 0\n");
774  return 1;
775  }
776  if (skb->ip_summed == CHECKSUM_COMPLETE &&
777  !csum_ipv6_magic(&ipv6_hdr(skb)->saddr, &ipv6_hdr(skb)->daddr,
778  skb->len, proto, skb->csum))
779  skb->ip_summed = CHECKSUM_UNNECESSARY;
780 
781  if (!skb_csum_unnecessary(skb))
782  skb->csum = ~csum_unfold(csum_ipv6_magic(&ipv6_hdr(skb)->saddr,
783  &ipv6_hdr(skb)->daddr,
784  skb->len, proto, 0));
785 
786  return 0;
787 }
788 
789 int __udp6_lib_rcv(struct sk_buff *skb, struct udp_table *udptable,
790  int proto)
791 {
792  struct net *net = dev_net(skb->dev);
793  struct sock *sk;
794  struct udphdr *uh;
795  const struct in6_addr *saddr, *daddr;
796  u32 ulen = 0;
797 
798  if (!pskb_may_pull(skb, sizeof(struct udphdr)))
799  goto discard;
800 
801  saddr = &ipv6_hdr(skb)->saddr;
802  daddr = &ipv6_hdr(skb)->daddr;
803  uh = udp_hdr(skb);
804 
805  ulen = ntohs(uh->len);
806  if (ulen > skb->len)
807  goto short_packet;
808 
809  if (proto == IPPROTO_UDP) {
810  /* UDP validates ulen. */
811 
812  /* Check for jumbo payload */
813  if (ulen == 0)
814  ulen = skb->len;
815 
816  if (ulen < sizeof(*uh))
817  goto short_packet;
818 
819  if (ulen < skb->len) {
820  if (pskb_trim_rcsum(skb, ulen))
821  goto short_packet;
822  saddr = &ipv6_hdr(skb)->saddr;
823  daddr = &ipv6_hdr(skb)->daddr;
824  uh = udp_hdr(skb);
825  }
826  }
827 
828  if (udp6_csum_init(skb, uh, proto))
829  goto discard;
830 
831  /*
832  * Multicast receive code
833  */
834  if (ipv6_addr_is_multicast(daddr))
835  return __udp6_lib_mcast_deliver(net, skb,
836  saddr, daddr, udptable);
837 
838  /* Unicast */
839 
840  /*
841  * check socket cache ... must talk to Alan about his plans
842  * for sock caches... i'll skip this for now.
843  */
844  sk = __udp6_lib_lookup_skb(skb, uh->source, uh->dest, udptable);
845  if (sk != NULL) {
846  int ret = udpv6_queue_rcv_skb(sk, skb);
847  sock_put(sk);
848 
849  /* a return value > 0 means to resubmit the input, but
850  * it wants the return to be -protocol, or 0
851  */
852  if (ret > 0)
853  return -ret;
854 
855  return 0;
856  }
857 
858  if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
859  goto discard;
860 
861  if (udp_lib_checksum_complete(skb))
862  goto discard;
863 
864  UDP6_INC_STATS_BH(net, UDP_MIB_NOPORTS, proto == IPPROTO_UDPLITE);
865  icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0);
866 
867  kfree_skb(skb);
868  return 0;
869 
870 short_packet:
871  LIMIT_NETDEBUG(KERN_DEBUG "UDP%sv6: short packet: From [%pI6c]:%u %d/%d to [%pI6c]:%u\n",
872  proto == IPPROTO_UDPLITE ? "-Lite" : "",
873  saddr,
874  ntohs(uh->source),
875  ulen,
876  skb->len,
877  daddr,
878  ntohs(uh->dest));
879 
880 discard:
881  UDP6_INC_STATS_BH(net, UDP_MIB_INERRORS, proto == IPPROTO_UDPLITE);
882  kfree_skb(skb);
883  return 0;
884 }
885 
886 static __inline__ int udpv6_rcv(struct sk_buff *skb)
887 {
888  return __udp6_lib_rcv(skb, &udp_table, IPPROTO_UDP);
889 }
890 
891 /*
892  * Throw away all pending data and cancel the corking. Socket is locked.
893  */
894 static void udp_v6_flush_pending_frames(struct sock *sk)
895 {
896  struct udp_sock *up = udp_sk(sk);
897 
898  if (up->pending == AF_INET)
899  udp_flush_pending_frames(sk);
900  else if (up->pending) {
901  up->len = 0;
902  up->pending = 0;
903  ip6_flush_pending_frames(sk);
904  }
905 }
906 
913 static void udp6_hwcsum_outgoing(struct sock *sk, struct sk_buff *skb,
914  const struct in6_addr *saddr,
915  const struct in6_addr *daddr, int len)
916 {
917  unsigned int offset;
918  struct udphdr *uh = udp_hdr(skb);
919  __wsum csum = 0;
920 
921  if (skb_queue_len(&sk->sk_write_queue) == 1) {
922  /* Only one fragment on the socket. */
923  skb->csum_start = skb_transport_header(skb) - skb->head;
924  skb->csum_offset = offsetof(struct udphdr, check);
925  uh->check = ~csum_ipv6_magic(saddr, daddr, len, IPPROTO_UDP, 0);
926  } else {
927  /*
928  * HW-checksum won't work as there are two or more
929  * fragments on the socket so that all csums of sk_buffs
930  * should be together
931  */
932  offset = skb_transport_offset(skb);
933  skb->csum = skb_checksum(skb, offset, skb->len - offset, 0);
934 
935  skb->ip_summed = CHECKSUM_NONE;
936 
937  skb_queue_walk(&sk->sk_write_queue, skb) {
938  csum = csum_add(csum, skb->csum);
939  }
940 
941  uh->check = csum_ipv6_magic(saddr, daddr, len, IPPROTO_UDP,
942  csum);
943  if (uh->check == 0)
944  uh->check = CSUM_MANGLED_0;
945  }
946 }
947 
948 /*
949  * Sending
950  */
951 
952 static int udp_v6_push_pending_frames(struct sock *sk)
953 {
954  struct sk_buff *skb;
955  struct udphdr *uh;
956  struct udp_sock *up = udp_sk(sk);
957  struct inet_sock *inet = inet_sk(sk);
958  struct flowi6 *fl6 = &inet->cork.fl.u.ip6;
959  int err = 0;
960  int is_udplite = IS_UDPLITE(sk);
961  __wsum csum = 0;
962 
963  /* Grab the skbuff where UDP header space exists. */
964  if ((skb = skb_peek(&sk->sk_write_queue)) == NULL)
965  goto out;
966 
967  /*
968  * Create a UDP header
969  */
970  uh = udp_hdr(skb);
971  uh->source = fl6->fl6_sport;
972  uh->dest = fl6->fl6_dport;
973  uh->len = htons(up->len);
974  uh->check = 0;
975 
976  if (is_udplite)
977  csum = udplite_csum_outgoing(sk, skb);
978  else if (skb->ip_summed == CHECKSUM_PARTIAL) { /* UDP hardware csum */
979  udp6_hwcsum_outgoing(sk, skb, &fl6->saddr, &fl6->daddr,
980  up->len);
981  goto send;
982  } else
983  csum = udp_csum_outgoing(sk, skb);
984 
985  /* add protocol-dependent pseudo-header */
986  uh->check = csum_ipv6_magic(&fl6->saddr, &fl6->daddr,
987  up->len, fl6->flowi6_proto, csum);
988  if (uh->check == 0)
989  uh->check = CSUM_MANGLED_0;
990 
991 send:
992  err = ip6_push_pending_frames(sk);
993  if (err) {
994  if (err == -ENOBUFS && !inet6_sk(sk)->recverr) {
995  UDP6_INC_STATS_USER(sock_net(sk),
996  UDP_MIB_SNDBUFERRORS, is_udplite);
997  err = 0;
998  }
999  } else
1000  UDP6_INC_STATS_USER(sock_net(sk),
1001  UDP_MIB_OUTDATAGRAMS, is_udplite);
1002 out:
1003  up->len = 0;
1004  up->pending = 0;
1005  return err;
1006 }
1007 
1008 int udpv6_sendmsg(struct kiocb *iocb, struct sock *sk,
1009  struct msghdr *msg, size_t len)
1010 {
1011  struct ipv6_txoptions opt_space;
1012  struct udp_sock *up = udp_sk(sk);
1013  struct inet_sock *inet = inet_sk(sk);
1014  struct ipv6_pinfo *np = inet6_sk(sk);
1015  struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *) msg->msg_name;
1016  struct in6_addr *daddr, *final_p, final;
1017  struct ipv6_txoptions *opt = NULL;
1018  struct ip6_flowlabel *flowlabel = NULL;
1019  struct flowi6 fl6;
1020  struct dst_entry *dst;
1021  int addr_len = msg->msg_namelen;
1022  int ulen = len;
1023  int hlimit = -1;
1024  int tclass = -1;
1025  int dontfrag = -1;
1026  int corkreq = up->corkflag || msg->msg_flags&MSG_MORE;
1027  int err;
1028  int connected = 0;
1029  int is_udplite = IS_UDPLITE(sk);
1030  int (*getfrag)(void *, char *, int, int, int, struct sk_buff *);
1031 
1032  /* destination address check */
1033  if (sin6) {
1034  if (addr_len < offsetof(struct sockaddr, sa_data))
1035  return -EINVAL;
1036 
1037  switch (sin6->sin6_family) {
1038  case AF_INET6:
1039  if (addr_len < SIN6_LEN_RFC2133)
1040  return -EINVAL;
1041  daddr = &sin6->sin6_addr;
1042  break;
1043  case AF_INET:
1044  goto do_udp_sendmsg;
1045  case AF_UNSPEC:
1046  msg->msg_name = sin6 = NULL;
1047  msg->msg_namelen = addr_len = 0;
1048  daddr = NULL;
1049  break;
1050  default:
1051  return -EINVAL;
1052  }
1053  } else if (!up->pending) {
1054  if (sk->sk_state != TCP_ESTABLISHED)
1055  return -EDESTADDRREQ;
1056  daddr = &np->daddr;
1057  } else
1058  daddr = NULL;
1059 
1060  if (daddr) {
1061  if (ipv6_addr_v4mapped(daddr)) {
1062  struct sockaddr_in sin;
1063  sin.sin_family = AF_INET;
1064  sin.sin_port = sin6 ? sin6->sin6_port : inet->inet_dport;
1065  sin.sin_addr.s_addr = daddr->s6_addr32[3];
1066  msg->msg_name = &sin;
1067  msg->msg_namelen = sizeof(sin);
1068 do_udp_sendmsg:
1069  if (__ipv6_only_sock(sk))
1070  return -ENETUNREACH;
1071  return udp_sendmsg(iocb, sk, msg, len);
1072  }
1073  }
1074 
1075  if (up->pending == AF_INET)
1076  return udp_sendmsg(iocb, sk, msg, len);
1077 
1078  /* Rough check on arithmetic overflow,
1079  better check is made in ip6_append_data().
1080  */
1081  if (len > INT_MAX - sizeof(struct udphdr))
1082  return -EMSGSIZE;
1083 
1084  if (up->pending) {
1085  /*
1086  * There are pending frames.
1087  * The socket lock must be held while it's corked.
1088  */
1089  lock_sock(sk);
1090  if (likely(up->pending)) {
1091  if (unlikely(up->pending != AF_INET6)) {
1092  release_sock(sk);
1093  return -EAFNOSUPPORT;
1094  }
1095  dst = NULL;
1096  goto do_append_data;
1097  }
1098  release_sock(sk);
1099  }
1100  ulen += sizeof(struct udphdr);
1101 
1102  memset(&fl6, 0, sizeof(fl6));
1103 
1104  if (sin6) {
1105  if (sin6->sin6_port == 0)
1106  return -EINVAL;
1107 
1108  fl6.fl6_dport = sin6->sin6_port;
1109  daddr = &sin6->sin6_addr;
1110 
1111  if (np->sndflow) {
1112  fl6.flowlabel = sin6->sin6_flowinfo&IPV6_FLOWINFO_MASK;
1113  if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) {
1114  flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
1115  if (flowlabel == NULL)
1116  return -EINVAL;
1117  daddr = &flowlabel->dst;
1118  }
1119  }
1120 
1121  /*
1122  * Otherwise it will be difficult to maintain
1123  * sk->sk_dst_cache.
1124  */
1125  if (sk->sk_state == TCP_ESTABLISHED &&
1126  ipv6_addr_equal(daddr, &np->daddr))
1127  daddr = &np->daddr;
1128 
1129  if (addr_len >= sizeof(struct sockaddr_in6) &&
1130  sin6->sin6_scope_id &&
1131  ipv6_addr_type(daddr)&IPV6_ADDR_LINKLOCAL)
1132  fl6.flowi6_oif = sin6->sin6_scope_id;
1133  } else {
1134  if (sk->sk_state != TCP_ESTABLISHED)
1135  return -EDESTADDRREQ;
1136 
1137  fl6.fl6_dport = inet->inet_dport;
1138  daddr = &np->daddr;
1139  fl6.flowlabel = np->flow_label;
1140  connected = 1;
1141  }
1142 
1143  if (!fl6.flowi6_oif)
1144  fl6.flowi6_oif = sk->sk_bound_dev_if;
1145 
1146  if (!fl6.flowi6_oif)
1147  fl6.flowi6_oif = np->sticky_pktinfo.ipi6_ifindex;
1148 
1149  fl6.flowi6_mark = sk->sk_mark;
1150 
1151  if (msg->msg_controllen) {
1152  opt = &opt_space;
1153  memset(opt, 0, sizeof(struct ipv6_txoptions));
1154  opt->tot_len = sizeof(*opt);
1155 
1156  err = datagram_send_ctl(sock_net(sk), sk, msg, &fl6, opt,
1157  &hlimit, &tclass, &dontfrag);
1158  if (err < 0) {
1159  fl6_sock_release(flowlabel);
1160  return err;
1161  }
1162  if ((fl6.flowlabel&IPV6_FLOWLABEL_MASK) && !flowlabel) {
1163  flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
1164  if (flowlabel == NULL)
1165  return -EINVAL;
1166  }
1167  if (!(opt->opt_nflen|opt->opt_flen))
1168  opt = NULL;
1169  connected = 0;
1170  }
1171  if (opt == NULL)
1172  opt = np->opt;
1173  if (flowlabel)
1174  opt = fl6_merge_options(&opt_space, flowlabel, opt);
1175  opt = ipv6_fixup_options(&opt_space, opt);
1176 
1177  fl6.flowi6_proto = sk->sk_protocol;
1178  if (!ipv6_addr_any(daddr))
1179  fl6.daddr = *daddr;
1180  else
1181  fl6.daddr.s6_addr[15] = 0x1; /* :: means loopback (BSD'ism) */
1182  if (ipv6_addr_any(&fl6.saddr) && !ipv6_addr_any(&np->saddr))
1183  fl6.saddr = np->saddr;
1184  fl6.fl6_sport = inet->inet_sport;
1185 
1186  final_p = fl6_update_dst(&fl6, opt, &final);
1187  if (final_p)
1188  connected = 0;
1189 
1190  if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr)) {
1191  fl6.flowi6_oif = np->mcast_oif;
1192  connected = 0;
1193  } else if (!fl6.flowi6_oif)
1194  fl6.flowi6_oif = np->ucast_oif;
1195 
1196  security_sk_classify_flow(sk, flowi6_to_flowi(&fl6));
1197 
1198  dst = ip6_sk_dst_lookup_flow(sk, &fl6, final_p, true);
1199  if (IS_ERR(dst)) {
1200  err = PTR_ERR(dst);
1201  dst = NULL;
1202  goto out;
1203  }
1204 
1205  if (hlimit < 0) {
1206  if (ipv6_addr_is_multicast(&fl6.daddr))
1207  hlimit = np->mcast_hops;
1208  else
1209  hlimit = np->hop_limit;
1210  if (hlimit < 0)
1211  hlimit = ip6_dst_hoplimit(dst);
1212  }
1213 
1214  if (tclass < 0)
1215  tclass = np->tclass;
1216 
1217  if (dontfrag < 0)
1218  dontfrag = np->dontfrag;
1219 
1220  if (msg->msg_flags&MSG_CONFIRM)
1221  goto do_confirm;
1222 back_from_confirm:
1223 
1224  lock_sock(sk);
1225  if (unlikely(up->pending)) {
1226  /* The socket is already corked while preparing it. */
1227  /* ... which is an evident application bug. --ANK */
1228  release_sock(sk);
1229 
1230  LIMIT_NETDEBUG(KERN_DEBUG "udp cork app bug 2\n");
1231  err = -EINVAL;
1232  goto out;
1233  }
1234 
1235  up->pending = AF_INET6;
1236 
1237 do_append_data:
1238  up->len += ulen;
1239  getfrag = is_udplite ? udplite_getfrag : ip_generic_getfrag;
1240  err = ip6_append_data(sk, getfrag, msg->msg_iov, ulen,
1241  sizeof(struct udphdr), hlimit, tclass, opt, &fl6,
1242  (struct rt6_info*)dst,
1243  corkreq ? msg->msg_flags|MSG_MORE : msg->msg_flags, dontfrag);
1244  if (err)
1245  udp_v6_flush_pending_frames(sk);
1246  else if (!corkreq)
1247  err = udp_v6_push_pending_frames(sk);
1248  else if (unlikely(skb_queue_empty(&sk->sk_write_queue)))
1249  up->pending = 0;
1250 
1251  if (dst) {
1252  if (connected) {
1253  ip6_dst_store(sk, dst,
1254  ipv6_addr_equal(&fl6.daddr, &np->daddr) ?
1255  &np->daddr : NULL,
1256 #ifdef CONFIG_IPV6_SUBTREES
1257  ipv6_addr_equal(&fl6.saddr, &np->saddr) ?
1258  &np->saddr :
1259 #endif
1260  NULL);
1261  } else {
1262  dst_release(dst);
1263  }
1264  dst = NULL;
1265  }
1266 
1267  if (err > 0)
1268  err = np->recverr ? net_xmit_errno(err) : 0;
1269  release_sock(sk);
1270 out:
1271  dst_release(dst);
1272  fl6_sock_release(flowlabel);
1273  if (!err)
1274  return len;
1275  /*
1276  * ENOBUFS = no kernel mem, SOCK_NOSPACE = no sndbuf space. Reporting
1277  * ENOBUFS might not be good (it's not tunable per se), but otherwise
1278  * we don't have a good statistic (IpOutDiscards but it can be too many
1279  * things). We could add another new stat but at least for now that
1280  * seems like overkill.
1281  */
1282  if (err == -ENOBUFS || test_bit(SOCK_NOSPACE, &sk->sk_socket->flags)) {
1283  UDP6_INC_STATS_USER(sock_net(sk),
1284  UDP_MIB_SNDBUFERRORS, is_udplite);
1285  }
1286  return err;
1287 
1288 do_confirm:
1289  dst_confirm(dst);
1290  if (!(msg->msg_flags&MSG_PROBE) || len)
1291  goto back_from_confirm;
1292  err = 0;
1293  goto out;
1294 }
1295 
1296 void udpv6_destroy_sock(struct sock *sk)
1297 {
1298  lock_sock(sk);
1299  udp_v6_flush_pending_frames(sk);
1300  release_sock(sk);
1301 
1302  inet6_destroy_sock(sk);
1303 }
1304 
1305 /*
1306  * Socket option code for UDP
1307  */
1308 int udpv6_setsockopt(struct sock *sk, int level, int optname,
1309  char __user *optval, unsigned int optlen)
1310 {
1311  if (level == SOL_UDP || level == SOL_UDPLITE)
1312  return udp_lib_setsockopt(sk, level, optname, optval, optlen,
1313  udp_v6_push_pending_frames);
1314  return ipv6_setsockopt(sk, level, optname, optval, optlen);
1315 }
1316 
1317 #ifdef CONFIG_COMPAT
1318 int compat_udpv6_setsockopt(struct sock *sk, int level, int optname,
1319  char __user *optval, unsigned int optlen)
1320 {
1321  if (level == SOL_UDP || level == SOL_UDPLITE)
1322  return udp_lib_setsockopt(sk, level, optname, optval, optlen,
1323  udp_v6_push_pending_frames);
1324  return compat_ipv6_setsockopt(sk, level, optname, optval, optlen);
1325 }
1326 #endif
1327 
1328 int udpv6_getsockopt(struct sock *sk, int level, int optname,
1329  char __user *optval, int __user *optlen)
1330 {
1331  if (level == SOL_UDP || level == SOL_UDPLITE)
1332  return udp_lib_getsockopt(sk, level, optname, optval, optlen);
1333  return ipv6_getsockopt(sk, level, optname, optval, optlen);
1334 }
1335 
1336 #ifdef CONFIG_COMPAT
1337 int compat_udpv6_getsockopt(struct sock *sk, int level, int optname,
1338  char __user *optval, int __user *optlen)
1339 {
1340  if (level == SOL_UDP || level == SOL_UDPLITE)
1341  return udp_lib_getsockopt(sk, level, optname, optval, optlen);
1342  return compat_ipv6_getsockopt(sk, level, optname, optval, optlen);
1343 }
1344 #endif
1345 
1346 static int udp6_ufo_send_check(struct sk_buff *skb)
1347 {
1348  const struct ipv6hdr *ipv6h;
1349  struct udphdr *uh;
1350 
1351  if (!pskb_may_pull(skb, sizeof(*uh)))
1352  return -EINVAL;
1353 
1354  ipv6h = ipv6_hdr(skb);
1355  uh = udp_hdr(skb);
1356 
1357  uh->check = ~csum_ipv6_magic(&ipv6h->saddr, &ipv6h->daddr, skb->len,
1358  IPPROTO_UDP, 0);
1359  skb->csum_start = skb_transport_header(skb) - skb->head;
1360  skb->csum_offset = offsetof(struct udphdr, check);
1361  skb->ip_summed = CHECKSUM_PARTIAL;
1362  return 0;
1363 }
1364 
1365 static struct sk_buff *udp6_ufo_fragment(struct sk_buff *skb,
1366  netdev_features_t features)
1367 {
1368  struct sk_buff *segs = ERR_PTR(-EINVAL);
1369  unsigned int mss;
1370  unsigned int unfrag_ip6hlen, unfrag_len;
1371  struct frag_hdr *fptr;
1372  u8 *mac_start, *prevhdr;
1373  u8 nexthdr;
1374  u8 frag_hdr_sz = sizeof(struct frag_hdr);
1375  int offset;
1376  __wsum csum;
1377 
1378  mss = skb_shinfo(skb)->gso_size;
1379  if (unlikely(skb->len <= mss))
1380  goto out;
1381 
1382  if (skb_gso_ok(skb, features | NETIF_F_GSO_ROBUST)) {
1383  /* Packet is from an untrusted source, reset gso_segs. */
1384  int type = skb_shinfo(skb)->gso_type;
1385 
1386  if (unlikely(type & ~(SKB_GSO_UDP | SKB_GSO_DODGY) ||
1387  !(type & (SKB_GSO_UDP))))
1388  goto out;
1389 
1390  skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(skb->len, mss);
1391 
1392  segs = NULL;
1393  goto out;
1394  }
1395 
1396  /* Do software UFO. Complete and fill in the UDP checksum as HW cannot
1397  * do checksum of UDP packets sent as multiple IP fragments.
1398  */
1399  offset = skb_checksum_start_offset(skb);
1400  csum = skb_checksum(skb, offset, skb->len - offset, 0);
1401  offset += skb->csum_offset;
1402  *(__sum16 *)(skb->data + offset) = csum_fold(csum);
1403  skb->ip_summed = CHECKSUM_NONE;
1404 
1405  /* Check if there is enough headroom to insert fragment header. */
1406  if ((skb_mac_header(skb) < skb->head + frag_hdr_sz) &&
1407  pskb_expand_head(skb, frag_hdr_sz, 0, GFP_ATOMIC))
1408  goto out;
1409 
1410  /* Find the unfragmentable header and shift it left by frag_hdr_sz
1411  * bytes to insert fragment header.
1412  */
1413  unfrag_ip6hlen = ip6_find_1stfragopt(skb, &prevhdr);
1414  nexthdr = *prevhdr;
1415  *prevhdr = NEXTHDR_FRAGMENT;
1416  unfrag_len = skb_network_header(skb) - skb_mac_header(skb) +
1417  unfrag_ip6hlen;
1418  mac_start = skb_mac_header(skb);
1419  memmove(mac_start-frag_hdr_sz, mac_start, unfrag_len);
1420 
1421  skb->mac_header -= frag_hdr_sz;
1422  skb->network_header -= frag_hdr_sz;
1423 
1424  fptr = (struct frag_hdr *)(skb_network_header(skb) + unfrag_ip6hlen);
1425  fptr->nexthdr = nexthdr;
1426  fptr->reserved = 0;
1427  ipv6_select_ident(fptr, (struct rt6_info *)skb_dst(skb));
1428 
1429  /* Fragment the skb. ipv6 header and the remaining fields of the
1430  * fragment header are updated in ipv6_gso_segment()
1431  */
1432  segs = skb_segment(skb, features);
1433 
1434 out:
1435  return segs;
1436 }
1437 
1438 static const struct inet6_protocol udpv6_protocol = {
1439  .handler = udpv6_rcv,
1440  .err_handler = udpv6_err,
1441  .gso_send_check = udp6_ufo_send_check,
1442  .gso_segment = udp6_ufo_fragment,
1443  .flags = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
1444 };
1445 
1446 /* ------------------------------------------------------------------------ */
1447 #ifdef CONFIG_PROC_FS
1448 
1449 static void udp6_sock_seq_show(struct seq_file *seq, struct sock *sp, int bucket)
1450 {
1451  struct inet_sock *inet = inet_sk(sp);
1452  struct ipv6_pinfo *np = inet6_sk(sp);
1453  const struct in6_addr *dest, *src;
1454  __u16 destp, srcp;
1455 
1456  dest = &np->daddr;
1457  src = &np->rcv_saddr;
1458  destp = ntohs(inet->inet_dport);
1459  srcp = ntohs(inet->inet_sport);
1460  seq_printf(seq,
1461  "%5d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1462  "%02X %08X:%08X %02X:%08lX %08X %5d %8d %lu %d %pK %d\n",
1463  bucket,
1464  src->s6_addr32[0], src->s6_addr32[1],
1465  src->s6_addr32[2], src->s6_addr32[3], srcp,
1466  dest->s6_addr32[0], dest->s6_addr32[1],
1467  dest->s6_addr32[2], dest->s6_addr32[3], destp,
1468  sp->sk_state,
1469  sk_wmem_alloc_get(sp),
1470  sk_rmem_alloc_get(sp),
1471  0, 0L, 0,
1472  from_kuid_munged(seq_user_ns(seq), sock_i_uid(sp)),
1473  0,
1474  sock_i_ino(sp),
1475  atomic_read(&sp->sk_refcnt), sp,
1476  atomic_read(&sp->sk_drops));
1477 }
1478 
1479 int udp6_seq_show(struct seq_file *seq, void *v)
1480 {
1481  if (v == SEQ_START_TOKEN)
1482  seq_printf(seq,
1483  " sl "
1484  "local_address "
1485  "remote_address "
1486  "st tx_queue rx_queue tr tm->when retrnsmt"
1487  " uid timeout inode ref pointer drops\n");
1488  else
1489  udp6_sock_seq_show(seq, v, ((struct udp_iter_state *)seq->private)->bucket);
1490  return 0;
1491 }
1492 
1493 static const struct file_operations udp6_afinfo_seq_fops = {
1494  .owner = THIS_MODULE,
1495  .open = udp_seq_open,
1496  .read = seq_read,
1497  .llseek = seq_lseek,
1498  .release = seq_release_net
1499 };
1500 
1501 static struct udp_seq_afinfo udp6_seq_afinfo = {
1502  .name = "udp6",
1503  .family = AF_INET6,
1504  .udp_table = &udp_table,
1505  .seq_fops = &udp6_afinfo_seq_fops,
1506  .seq_ops = {
1507  .show = udp6_seq_show,
1508  },
1509 };
1510 
1511 int __net_init udp6_proc_init(struct net *net)
1512 {
1513  return udp_proc_register(net, &udp6_seq_afinfo);
1514 }
1515 
1516 void udp6_proc_exit(struct net *net) {
1517  udp_proc_unregister(net, &udp6_seq_afinfo);
1518 }
1519 #endif /* CONFIG_PROC_FS */
1520 
1521 /* ------------------------------------------------------------------------ */
1522 
1523 struct proto udpv6_prot = {
1524  .name = "UDPv6",
1525  .owner = THIS_MODULE,
1526  .close = udp_lib_close,
1527  .connect = ip6_datagram_connect,
1528  .disconnect = udp_disconnect,
1529  .ioctl = udp_ioctl,
1530  .destroy = udpv6_destroy_sock,
1531  .setsockopt = udpv6_setsockopt,
1532  .getsockopt = udpv6_getsockopt,
1533  .sendmsg = udpv6_sendmsg,
1534  .recvmsg = udpv6_recvmsg,
1535  .backlog_rcv = __udpv6_queue_rcv_skb,
1536  .hash = udp_lib_hash,
1537  .unhash = udp_lib_unhash,
1538  .rehash = udp_v6_rehash,
1539  .get_port = udp_v6_get_port,
1540  .memory_allocated = &udp_memory_allocated,
1541  .sysctl_mem = sysctl_udp_mem,
1542  .sysctl_wmem = &sysctl_udp_wmem_min,
1543  .sysctl_rmem = &sysctl_udp_rmem_min,
1544  .obj_size = sizeof(struct udp6_sock),
1545  .slab_flags = SLAB_DESTROY_BY_RCU,
1546  .h.udp_table = &udp_table,
1547 #ifdef CONFIG_COMPAT
1548  .compat_setsockopt = compat_udpv6_setsockopt,
1549  .compat_getsockopt = compat_udpv6_getsockopt,
1550 #endif
1551  .clear_sk = sk_prot_clear_portaddr_nulls,
1552 };
1553 
1554 static struct inet_protosw udpv6_protosw = {
1555  .type = SOCK_DGRAM,
1556  .protocol = IPPROTO_UDP,
1557  .prot = &udpv6_prot,
1558  .ops = &inet6_dgram_ops,
1559  .no_check = UDP_CSUM_DEFAULT,
1560  .flags = INET_PROTOSW_PERMANENT,
1561 };
1562 
1563 
1564 int __init udpv6_init(void)
1565 {
1566  int ret;
1567 
1568  ret = inet6_add_protocol(&udpv6_protocol, IPPROTO_UDP);
1569  if (ret)
1570  goto out;
1571 
1572  ret = inet6_register_protosw(&udpv6_protosw);
1573  if (ret)
1574  goto out_udpv6_protocol;
1575 out:
1576  return ret;
1577 
1578 out_udpv6_protocol:
1579  inet6_del_protocol(&udpv6_protocol, IPPROTO_UDP);
1580  goto out;
1581 }
1582 
1583 void udpv6_exit(void)
1584 {
1585  inet6_unregister_protosw(&udpv6_protosw);
1586  inet6_del_protocol(&udpv6_protocol, IPPROTO_UDP);
1587 }
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