xref: /openbmc/linux/net/ipv6/udp.c (revision 9d749629)
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 	int is_udp4;
374 	bool slow;
375 
376 	if (addr_len)
377 		*addr_len = sizeof(struct sockaddr_in6);
378 
379 	if (flags & MSG_ERRQUEUE)
380 		return ipv6_recv_error(sk, msg, len);
381 
382 	if (np->rxpmtu && np->rxopt.bits.rxpmtu)
383 		return ipv6_recv_rxpmtu(sk, msg, len);
384 
385 try_again:
386 	skb = __skb_recv_datagram(sk, flags | (noblock ? MSG_DONTWAIT : 0),
387 				  &peeked, &off, &err);
388 	if (!skb)
389 		goto out;
390 
391 	ulen = skb->len - sizeof(struct udphdr);
392 	copied = len;
393 	if (copied > ulen)
394 		copied = ulen;
395 	else if (copied < ulen)
396 		msg->msg_flags |= MSG_TRUNC;
397 
398 	is_udp4 = (skb->protocol == htons(ETH_P_IP));
399 
400 	/*
401 	 * If checksum is needed at all, try to do it while copying the
402 	 * data.  If the data is truncated, or if we only want a partial
403 	 * coverage checksum (UDP-Lite), do it before the copy.
404 	 */
405 
406 	if (copied < ulen || UDP_SKB_CB(skb)->partial_cov) {
407 		if (udp_lib_checksum_complete(skb))
408 			goto csum_copy_err;
409 	}
410 
411 	if (skb_csum_unnecessary(skb))
412 		err = skb_copy_datagram_iovec(skb, sizeof(struct udphdr),
413 					      msg->msg_iov, copied);
414 	else {
415 		err = skb_copy_and_csum_datagram_iovec(skb, sizeof(struct udphdr), msg->msg_iov);
416 		if (err == -EINVAL)
417 			goto csum_copy_err;
418 	}
419 	if (unlikely(err)) {
420 		trace_kfree_skb(skb, udpv6_recvmsg);
421 		if (!peeked) {
422 			atomic_inc(&sk->sk_drops);
423 			if (is_udp4)
424 				UDP_INC_STATS_USER(sock_net(sk),
425 						   UDP_MIB_INERRORS,
426 						   is_udplite);
427 			else
428 				UDP6_INC_STATS_USER(sock_net(sk),
429 						    UDP_MIB_INERRORS,
430 						    is_udplite);
431 		}
432 		goto out_free;
433 	}
434 	if (!peeked) {
435 		if (is_udp4)
436 			UDP_INC_STATS_USER(sock_net(sk),
437 					UDP_MIB_INDATAGRAMS, is_udplite);
438 		else
439 			UDP6_INC_STATS_USER(sock_net(sk),
440 					UDP_MIB_INDATAGRAMS, is_udplite);
441 	}
442 
443 	sock_recv_ts_and_drops(msg, sk, skb);
444 
445 	/* Copy the address. */
446 	if (msg->msg_name) {
447 		struct sockaddr_in6 *sin6;
448 
449 		sin6 = (struct sockaddr_in6 *) msg->msg_name;
450 		sin6->sin6_family = AF_INET6;
451 		sin6->sin6_port = udp_hdr(skb)->source;
452 		sin6->sin6_flowinfo = 0;
453 		sin6->sin6_scope_id = 0;
454 
455 		if (is_udp4)
456 			ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr,
457 					       &sin6->sin6_addr);
458 		else {
459 			sin6->sin6_addr = ipv6_hdr(skb)->saddr;
460 			if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL)
461 				sin6->sin6_scope_id = IP6CB(skb)->iif;
462 		}
463 
464 	}
465 	if (is_udp4) {
466 		if (inet->cmsg_flags)
467 			ip_cmsg_recv(msg, skb);
468 	} else {
469 		if (np->rxopt.all)
470 			ip6_datagram_recv_ctl(sk, msg, skb);
471 	}
472 
473 	err = copied;
474 	if (flags & MSG_TRUNC)
475 		err = ulen;
476 
477 out_free:
478 	skb_free_datagram_locked(sk, skb);
479 out:
480 	return err;
481 
482 csum_copy_err:
483 	slow = lock_sock_fast(sk);
484 	if (!skb_kill_datagram(sk, skb, flags)) {
485 		if (is_udp4)
486 			UDP_INC_STATS_USER(sock_net(sk),
487 					UDP_MIB_INERRORS, is_udplite);
488 		else
489 			UDP6_INC_STATS_USER(sock_net(sk),
490 					UDP_MIB_INERRORS, is_udplite);
491 	}
492 	unlock_sock_fast(sk, slow);
493 
494 	if (noblock)
495 		return -EAGAIN;
496 
497 	/* starting over for a new packet */
498 	msg->msg_flags &= ~MSG_TRUNC;
499 	goto try_again;
500 }
501 
502 void __udp6_lib_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
503 		    u8 type, u8 code, int offset, __be32 info,
504 		    struct udp_table *udptable)
505 {
506 	struct ipv6_pinfo *np;
507 	const struct ipv6hdr *hdr = (const struct ipv6hdr *)skb->data;
508 	const struct in6_addr *saddr = &hdr->saddr;
509 	const struct in6_addr *daddr = &hdr->daddr;
510 	struct udphdr *uh = (struct udphdr*)(skb->data+offset);
511 	struct sock *sk;
512 	int err;
513 
514 	sk = __udp6_lib_lookup(dev_net(skb->dev), daddr, uh->dest,
515 			       saddr, uh->source, inet6_iif(skb), udptable);
516 	if (sk == NULL)
517 		return;
518 
519 	if (type == ICMPV6_PKT_TOOBIG)
520 		ip6_sk_update_pmtu(skb, sk, info);
521 	if (type == NDISC_REDIRECT)
522 		ip6_sk_redirect(skb, sk);
523 
524 	np = inet6_sk(sk);
525 
526 	if (!icmpv6_err_convert(type, code, &err) && !np->recverr)
527 		goto out;
528 
529 	if (sk->sk_state != TCP_ESTABLISHED && !np->recverr)
530 		goto out;
531 
532 	if (np->recverr)
533 		ipv6_icmp_error(sk, skb, err, uh->dest, ntohl(info), (u8 *)(uh+1));
534 
535 	sk->sk_err = err;
536 	sk->sk_error_report(sk);
537 out:
538 	sock_put(sk);
539 }
540 
541 static int __udpv6_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
542 {
543 	int rc;
544 
545 	if (!ipv6_addr_any(&inet6_sk(sk)->daddr))
546 		sock_rps_save_rxhash(sk, skb);
547 
548 	rc = sock_queue_rcv_skb(sk, skb);
549 	if (rc < 0) {
550 		int is_udplite = IS_UDPLITE(sk);
551 
552 		/* Note that an ENOMEM error is charged twice */
553 		if (rc == -ENOMEM)
554 			UDP6_INC_STATS_BH(sock_net(sk),
555 					UDP_MIB_RCVBUFERRORS, is_udplite);
556 		UDP6_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
557 		kfree_skb(skb);
558 		return -1;
559 	}
560 	return 0;
561 }
562 
563 static __inline__ void udpv6_err(struct sk_buff *skb,
564 				 struct inet6_skb_parm *opt, u8 type,
565 				 u8 code, int offset, __be32 info     )
566 {
567 	__udp6_lib_err(skb, opt, type, code, offset, info, &udp_table);
568 }
569 
570 static struct static_key udpv6_encap_needed __read_mostly;
571 void udpv6_encap_enable(void)
572 {
573 	if (!static_key_enabled(&udpv6_encap_needed))
574 		static_key_slow_inc(&udpv6_encap_needed);
575 }
576 EXPORT_SYMBOL(udpv6_encap_enable);
577 
578 int udpv6_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
579 {
580 	struct udp_sock *up = udp_sk(sk);
581 	int rc;
582 	int is_udplite = IS_UDPLITE(sk);
583 
584 	if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
585 		goto drop;
586 
587 	if (static_key_false(&udpv6_encap_needed) && up->encap_type) {
588 		int (*encap_rcv)(struct sock *sk, struct sk_buff *skb);
589 
590 		/*
591 		 * This is an encapsulation socket so pass the skb to
592 		 * the socket's udp_encap_rcv() hook. Otherwise, just
593 		 * fall through and pass this up the UDP socket.
594 		 * up->encap_rcv() returns the following value:
595 		 * =0 if skb was successfully passed to the encap
596 		 *    handler or was discarded by it.
597 		 * >0 if skb should be passed on to UDP.
598 		 * <0 if skb should be resubmitted as proto -N
599 		 */
600 
601 		/* if we're overly short, let UDP handle it */
602 		encap_rcv = ACCESS_ONCE(up->encap_rcv);
603 		if (skb->len > sizeof(struct udphdr) && encap_rcv != NULL) {
604 			int ret;
605 
606 			ret = encap_rcv(sk, skb);
607 			if (ret <= 0) {
608 				UDP_INC_STATS_BH(sock_net(sk),
609 						 UDP_MIB_INDATAGRAMS,
610 						 is_udplite);
611 				return -ret;
612 			}
613 		}
614 
615 		/* FALLTHROUGH -- it's a UDP Packet */
616 	}
617 
618 	/*
619 	 * UDP-Lite specific tests, ignored on UDP sockets (see net/ipv4/udp.c).
620 	 */
621 	if ((is_udplite & UDPLITE_RECV_CC)  &&  UDP_SKB_CB(skb)->partial_cov) {
622 
623 		if (up->pcrlen == 0) {          /* full coverage was set  */
624 			LIMIT_NETDEBUG(KERN_WARNING "UDPLITE6: partial coverage"
625 				" %d while full coverage %d requested\n",
626 				UDP_SKB_CB(skb)->cscov, skb->len);
627 			goto drop;
628 		}
629 		if (UDP_SKB_CB(skb)->cscov  <  up->pcrlen) {
630 			LIMIT_NETDEBUG(KERN_WARNING "UDPLITE6: coverage %d "
631 						    "too small, need min %d\n",
632 				       UDP_SKB_CB(skb)->cscov, up->pcrlen);
633 			goto drop;
634 		}
635 	}
636 
637 	if (rcu_access_pointer(sk->sk_filter)) {
638 		if (udp_lib_checksum_complete(skb))
639 			goto drop;
640 	}
641 
642 	if (sk_rcvqueues_full(sk, skb, sk->sk_rcvbuf))
643 		goto drop;
644 
645 	skb_dst_drop(skb);
646 
647 	bh_lock_sock(sk);
648 	rc = 0;
649 	if (!sock_owned_by_user(sk))
650 		rc = __udpv6_queue_rcv_skb(sk, skb);
651 	else if (sk_add_backlog(sk, skb, sk->sk_rcvbuf)) {
652 		bh_unlock_sock(sk);
653 		goto drop;
654 	}
655 	bh_unlock_sock(sk);
656 
657 	return rc;
658 drop:
659 	UDP6_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
660 	atomic_inc(&sk->sk_drops);
661 	kfree_skb(skb);
662 	return -1;
663 }
664 
665 static struct sock *udp_v6_mcast_next(struct net *net, struct sock *sk,
666 				      __be16 loc_port, const struct in6_addr *loc_addr,
667 				      __be16 rmt_port, const struct in6_addr *rmt_addr,
668 				      int dif)
669 {
670 	struct hlist_nulls_node *node;
671 	struct sock *s = sk;
672 	unsigned short num = ntohs(loc_port);
673 
674 	sk_nulls_for_each_from(s, node) {
675 		struct inet_sock *inet = inet_sk(s);
676 
677 		if (!net_eq(sock_net(s), net))
678 			continue;
679 
680 		if (udp_sk(s)->udp_port_hash == num &&
681 		    s->sk_family == PF_INET6) {
682 			struct ipv6_pinfo *np = inet6_sk(s);
683 			if (inet->inet_dport) {
684 				if (inet->inet_dport != rmt_port)
685 					continue;
686 			}
687 			if (!ipv6_addr_any(&np->daddr) &&
688 			    !ipv6_addr_equal(&np->daddr, rmt_addr))
689 				continue;
690 
691 			if (s->sk_bound_dev_if && s->sk_bound_dev_if != dif)
692 				continue;
693 
694 			if (!ipv6_addr_any(&np->rcv_saddr)) {
695 				if (!ipv6_addr_equal(&np->rcv_saddr, loc_addr))
696 					continue;
697 			}
698 			if (!inet6_mc_check(s, loc_addr, rmt_addr))
699 				continue;
700 			return s;
701 		}
702 	}
703 	return NULL;
704 }
705 
706 static void flush_stack(struct sock **stack, unsigned int count,
707 			struct sk_buff *skb, unsigned int final)
708 {
709 	struct sk_buff *skb1 = NULL;
710 	struct sock *sk;
711 	unsigned int i;
712 
713 	for (i = 0; i < count; i++) {
714 		sk = stack[i];
715 		if (likely(skb1 == NULL))
716 			skb1 = (i == final) ? skb : skb_clone(skb, GFP_ATOMIC);
717 		if (!skb1) {
718 			atomic_inc(&sk->sk_drops);
719 			UDP6_INC_STATS_BH(sock_net(sk), UDP_MIB_RCVBUFERRORS,
720 					  IS_UDPLITE(sk));
721 			UDP6_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS,
722 					  IS_UDPLITE(sk));
723 		}
724 
725 		if (skb1 && udpv6_queue_rcv_skb(sk, skb1) <= 0)
726 			skb1 = NULL;
727 	}
728 	if (unlikely(skb1))
729 		kfree_skb(skb1);
730 }
731 /*
732  * Note: called only from the BH handler context,
733  * so we don't need to lock the hashes.
734  */
735 static int __udp6_lib_mcast_deliver(struct net *net, struct sk_buff *skb,
736 		const struct in6_addr *saddr, const struct in6_addr *daddr,
737 		struct udp_table *udptable)
738 {
739 	struct sock *sk, *stack[256 / sizeof(struct sock *)];
740 	const struct udphdr *uh = udp_hdr(skb);
741 	struct udp_hslot *hslot = udp_hashslot(udptable, net, ntohs(uh->dest));
742 	int dif;
743 	unsigned int i, count = 0;
744 
745 	spin_lock(&hslot->lock);
746 	sk = sk_nulls_head(&hslot->head);
747 	dif = inet6_iif(skb);
748 	sk = udp_v6_mcast_next(net, sk, uh->dest, daddr, uh->source, saddr, dif);
749 	while (sk) {
750 		stack[count++] = sk;
751 		sk = udp_v6_mcast_next(net, sk_nulls_next(sk), uh->dest, daddr,
752 				       uh->source, saddr, dif);
753 		if (unlikely(count == ARRAY_SIZE(stack))) {
754 			if (!sk)
755 				break;
756 			flush_stack(stack, count, skb, ~0);
757 			count = 0;
758 		}
759 	}
760 	/*
761 	 * before releasing the lock, we must take reference on sockets
762 	 */
763 	for (i = 0; i < count; i++)
764 		sock_hold(stack[i]);
765 
766 	spin_unlock(&hslot->lock);
767 
768 	if (count) {
769 		flush_stack(stack, count, skb, count - 1);
770 
771 		for (i = 0; i < count; i++)
772 			sock_put(stack[i]);
773 	} else {
774 		kfree_skb(skb);
775 	}
776 	return 0;
777 }
778 
779 int __udp6_lib_rcv(struct sk_buff *skb, struct udp_table *udptable,
780 		   int proto)
781 {
782 	struct net *net = dev_net(skb->dev);
783 	struct sock *sk;
784 	struct udphdr *uh;
785 	const struct in6_addr *saddr, *daddr;
786 	u32 ulen = 0;
787 
788 	if (!pskb_may_pull(skb, sizeof(struct udphdr)))
789 		goto discard;
790 
791 	saddr = &ipv6_hdr(skb)->saddr;
792 	daddr = &ipv6_hdr(skb)->daddr;
793 	uh = udp_hdr(skb);
794 
795 	ulen = ntohs(uh->len);
796 	if (ulen > skb->len)
797 		goto short_packet;
798 
799 	if (proto == IPPROTO_UDP) {
800 		/* UDP validates ulen. */
801 
802 		/* Check for jumbo payload */
803 		if (ulen == 0)
804 			ulen = skb->len;
805 
806 		if (ulen < sizeof(*uh))
807 			goto short_packet;
808 
809 		if (ulen < skb->len) {
810 			if (pskb_trim_rcsum(skb, ulen))
811 				goto short_packet;
812 			saddr = &ipv6_hdr(skb)->saddr;
813 			daddr = &ipv6_hdr(skb)->daddr;
814 			uh = udp_hdr(skb);
815 		}
816 	}
817 
818 	if (udp6_csum_init(skb, uh, proto))
819 		goto discard;
820 
821 	/*
822 	 *	Multicast receive code
823 	 */
824 	if (ipv6_addr_is_multicast(daddr))
825 		return __udp6_lib_mcast_deliver(net, skb,
826 				saddr, daddr, udptable);
827 
828 	/* Unicast */
829 
830 	/*
831 	 * check socket cache ... must talk to Alan about his plans
832 	 * for sock caches... i'll skip this for now.
833 	 */
834 	sk = __udp6_lib_lookup_skb(skb, uh->source, uh->dest, udptable);
835 	if (sk != NULL) {
836 		int ret = udpv6_queue_rcv_skb(sk, skb);
837 		sock_put(sk);
838 
839 		/* a return value > 0 means to resubmit the input, but
840 		 * it wants the return to be -protocol, or 0
841 		 */
842 		if (ret > 0)
843 			return -ret;
844 
845 		return 0;
846 	}
847 
848 	if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
849 		goto discard;
850 
851 	if (udp_lib_checksum_complete(skb))
852 		goto discard;
853 
854 	UDP6_INC_STATS_BH(net, UDP_MIB_NOPORTS, proto == IPPROTO_UDPLITE);
855 	icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0);
856 
857 	kfree_skb(skb);
858 	return 0;
859 
860 short_packet:
861 	LIMIT_NETDEBUG(KERN_DEBUG "UDP%sv6: short packet: From [%pI6c]:%u %d/%d to [%pI6c]:%u\n",
862 		       proto == IPPROTO_UDPLITE ? "-Lite" : "",
863 		       saddr,
864 		       ntohs(uh->source),
865 		       ulen,
866 		       skb->len,
867 		       daddr,
868 		       ntohs(uh->dest));
869 
870 discard:
871 	UDP6_INC_STATS_BH(net, UDP_MIB_INERRORS, proto == IPPROTO_UDPLITE);
872 	kfree_skb(skb);
873 	return 0;
874 }
875 
876 static __inline__ int udpv6_rcv(struct sk_buff *skb)
877 {
878 	return __udp6_lib_rcv(skb, &udp_table, IPPROTO_UDP);
879 }
880 
881 /*
882  * Throw away all pending data and cancel the corking. Socket is locked.
883  */
884 static void udp_v6_flush_pending_frames(struct sock *sk)
885 {
886 	struct udp_sock *up = udp_sk(sk);
887 
888 	if (up->pending == AF_INET)
889 		udp_flush_pending_frames(sk);
890 	else if (up->pending) {
891 		up->len = 0;
892 		up->pending = 0;
893 		ip6_flush_pending_frames(sk);
894 	}
895 }
896 
897 /**
898  * 	udp6_hwcsum_outgoing  -  handle outgoing HW checksumming
899  * 	@sk: 	socket we are sending on
900  * 	@skb: 	sk_buff containing the filled-in UDP header
901  * 	        (checksum field must be zeroed out)
902  */
903 static void udp6_hwcsum_outgoing(struct sock *sk, struct sk_buff *skb,
904 				 const struct in6_addr *saddr,
905 				 const struct in6_addr *daddr, int len)
906 {
907 	unsigned int offset;
908 	struct udphdr *uh = udp_hdr(skb);
909 	__wsum csum = 0;
910 
911 	if (skb_queue_len(&sk->sk_write_queue) == 1) {
912 		/* Only one fragment on the socket.  */
913 		skb->csum_start = skb_transport_header(skb) - skb->head;
914 		skb->csum_offset = offsetof(struct udphdr, check);
915 		uh->check = ~csum_ipv6_magic(saddr, daddr, len, IPPROTO_UDP, 0);
916 	} else {
917 		/*
918 		 * HW-checksum won't work as there are two or more
919 		 * fragments on the socket so that all csums of sk_buffs
920 		 * should be together
921 		 */
922 		offset = skb_transport_offset(skb);
923 		skb->csum = skb_checksum(skb, offset, skb->len - offset, 0);
924 
925 		skb->ip_summed = CHECKSUM_NONE;
926 
927 		skb_queue_walk(&sk->sk_write_queue, skb) {
928 			csum = csum_add(csum, skb->csum);
929 		}
930 
931 		uh->check = csum_ipv6_magic(saddr, daddr, len, IPPROTO_UDP,
932 					    csum);
933 		if (uh->check == 0)
934 			uh->check = CSUM_MANGLED_0;
935 	}
936 }
937 
938 /*
939  *	Sending
940  */
941 
942 static int udp_v6_push_pending_frames(struct sock *sk)
943 {
944 	struct sk_buff *skb;
945 	struct udphdr *uh;
946 	struct udp_sock  *up = udp_sk(sk);
947 	struct inet_sock *inet = inet_sk(sk);
948 	struct flowi6 *fl6 = &inet->cork.fl.u.ip6;
949 	int err = 0;
950 	int is_udplite = IS_UDPLITE(sk);
951 	__wsum csum = 0;
952 
953 	/* Grab the skbuff where UDP header space exists. */
954 	if ((skb = skb_peek(&sk->sk_write_queue)) == NULL)
955 		goto out;
956 
957 	/*
958 	 * Create a UDP header
959 	 */
960 	uh = udp_hdr(skb);
961 	uh->source = fl6->fl6_sport;
962 	uh->dest = fl6->fl6_dport;
963 	uh->len = htons(up->len);
964 	uh->check = 0;
965 
966 	if (is_udplite)
967 		csum = udplite_csum_outgoing(sk, skb);
968 	else if (skb->ip_summed == CHECKSUM_PARTIAL) { /* UDP hardware csum */
969 		udp6_hwcsum_outgoing(sk, skb, &fl6->saddr, &fl6->daddr,
970 				     up->len);
971 		goto send;
972 	} else
973 		csum = udp_csum_outgoing(sk, skb);
974 
975 	/* add protocol-dependent pseudo-header */
976 	uh->check = csum_ipv6_magic(&fl6->saddr, &fl6->daddr,
977 				    up->len, fl6->flowi6_proto, csum);
978 	if (uh->check == 0)
979 		uh->check = CSUM_MANGLED_0;
980 
981 send:
982 	err = ip6_push_pending_frames(sk);
983 	if (err) {
984 		if (err == -ENOBUFS && !inet6_sk(sk)->recverr) {
985 			UDP6_INC_STATS_USER(sock_net(sk),
986 					    UDP_MIB_SNDBUFERRORS, is_udplite);
987 			err = 0;
988 		}
989 	} else
990 		UDP6_INC_STATS_USER(sock_net(sk),
991 				    UDP_MIB_OUTDATAGRAMS, is_udplite);
992 out:
993 	up->len = 0;
994 	up->pending = 0;
995 	return err;
996 }
997 
998 int udpv6_sendmsg(struct kiocb *iocb, struct sock *sk,
999 		  struct msghdr *msg, size_t len)
1000 {
1001 	struct ipv6_txoptions opt_space;
1002 	struct udp_sock *up = udp_sk(sk);
1003 	struct inet_sock *inet = inet_sk(sk);
1004 	struct ipv6_pinfo *np = inet6_sk(sk);
1005 	struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *) msg->msg_name;
1006 	struct in6_addr *daddr, *final_p, final;
1007 	struct ipv6_txoptions *opt = NULL;
1008 	struct ip6_flowlabel *flowlabel = NULL;
1009 	struct flowi6 fl6;
1010 	struct dst_entry *dst;
1011 	int addr_len = msg->msg_namelen;
1012 	int ulen = len;
1013 	int hlimit = -1;
1014 	int tclass = -1;
1015 	int dontfrag = -1;
1016 	int corkreq = up->corkflag || msg->msg_flags&MSG_MORE;
1017 	int err;
1018 	int connected = 0;
1019 	int is_udplite = IS_UDPLITE(sk);
1020 	int (*getfrag)(void *, char *, int, int, int, struct sk_buff *);
1021 
1022 	/* destination address check */
1023 	if (sin6) {
1024 		if (addr_len < offsetof(struct sockaddr, sa_data))
1025 			return -EINVAL;
1026 
1027 		switch (sin6->sin6_family) {
1028 		case AF_INET6:
1029 			if (addr_len < SIN6_LEN_RFC2133)
1030 				return -EINVAL;
1031 			daddr = &sin6->sin6_addr;
1032 			break;
1033 		case AF_INET:
1034 			goto do_udp_sendmsg;
1035 		case AF_UNSPEC:
1036 			msg->msg_name = sin6 = NULL;
1037 			msg->msg_namelen = addr_len = 0;
1038 			daddr = NULL;
1039 			break;
1040 		default:
1041 			return -EINVAL;
1042 		}
1043 	} else if (!up->pending) {
1044 		if (sk->sk_state != TCP_ESTABLISHED)
1045 			return -EDESTADDRREQ;
1046 		daddr = &np->daddr;
1047 	} else
1048 		daddr = NULL;
1049 
1050 	if (daddr) {
1051 		if (ipv6_addr_v4mapped(daddr)) {
1052 			struct sockaddr_in sin;
1053 			sin.sin_family = AF_INET;
1054 			sin.sin_port = sin6 ? sin6->sin6_port : inet->inet_dport;
1055 			sin.sin_addr.s_addr = daddr->s6_addr32[3];
1056 			msg->msg_name = &sin;
1057 			msg->msg_namelen = sizeof(sin);
1058 do_udp_sendmsg:
1059 			if (__ipv6_only_sock(sk))
1060 				return -ENETUNREACH;
1061 			return udp_sendmsg(iocb, sk, msg, len);
1062 		}
1063 	}
1064 
1065 	if (up->pending == AF_INET)
1066 		return udp_sendmsg(iocb, sk, msg, len);
1067 
1068 	/* Rough check on arithmetic overflow,
1069 	   better check is made in ip6_append_data().
1070 	   */
1071 	if (len > INT_MAX - sizeof(struct udphdr))
1072 		return -EMSGSIZE;
1073 
1074 	if (up->pending) {
1075 		/*
1076 		 * There are pending frames.
1077 		 * The socket lock must be held while it's corked.
1078 		 */
1079 		lock_sock(sk);
1080 		if (likely(up->pending)) {
1081 			if (unlikely(up->pending != AF_INET6)) {
1082 				release_sock(sk);
1083 				return -EAFNOSUPPORT;
1084 			}
1085 			dst = NULL;
1086 			goto do_append_data;
1087 		}
1088 		release_sock(sk);
1089 	}
1090 	ulen += sizeof(struct udphdr);
1091 
1092 	memset(&fl6, 0, sizeof(fl6));
1093 
1094 	if (sin6) {
1095 		if (sin6->sin6_port == 0)
1096 			return -EINVAL;
1097 
1098 		fl6.fl6_dport = sin6->sin6_port;
1099 		daddr = &sin6->sin6_addr;
1100 
1101 		if (np->sndflow) {
1102 			fl6.flowlabel = sin6->sin6_flowinfo&IPV6_FLOWINFO_MASK;
1103 			if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) {
1104 				flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
1105 				if (flowlabel == NULL)
1106 					return -EINVAL;
1107 				daddr = &flowlabel->dst;
1108 			}
1109 		}
1110 
1111 		/*
1112 		 * Otherwise it will be difficult to maintain
1113 		 * sk->sk_dst_cache.
1114 		 */
1115 		if (sk->sk_state == TCP_ESTABLISHED &&
1116 		    ipv6_addr_equal(daddr, &np->daddr))
1117 			daddr = &np->daddr;
1118 
1119 		if (addr_len >= sizeof(struct sockaddr_in6) &&
1120 		    sin6->sin6_scope_id &&
1121 		    ipv6_addr_type(daddr)&IPV6_ADDR_LINKLOCAL)
1122 			fl6.flowi6_oif = sin6->sin6_scope_id;
1123 	} else {
1124 		if (sk->sk_state != TCP_ESTABLISHED)
1125 			return -EDESTADDRREQ;
1126 
1127 		fl6.fl6_dport = inet->inet_dport;
1128 		daddr = &np->daddr;
1129 		fl6.flowlabel = np->flow_label;
1130 		connected = 1;
1131 	}
1132 
1133 	if (!fl6.flowi6_oif)
1134 		fl6.flowi6_oif = sk->sk_bound_dev_if;
1135 
1136 	if (!fl6.flowi6_oif)
1137 		fl6.flowi6_oif = np->sticky_pktinfo.ipi6_ifindex;
1138 
1139 	fl6.flowi6_mark = sk->sk_mark;
1140 
1141 	if (msg->msg_controllen) {
1142 		opt = &opt_space;
1143 		memset(opt, 0, sizeof(struct ipv6_txoptions));
1144 		opt->tot_len = sizeof(*opt);
1145 
1146 		err = ip6_datagram_send_ctl(sock_net(sk), sk, msg, &fl6, opt,
1147 					    &hlimit, &tclass, &dontfrag);
1148 		if (err < 0) {
1149 			fl6_sock_release(flowlabel);
1150 			return err;
1151 		}
1152 		if ((fl6.flowlabel&IPV6_FLOWLABEL_MASK) && !flowlabel) {
1153 			flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
1154 			if (flowlabel == NULL)
1155 				return -EINVAL;
1156 		}
1157 		if (!(opt->opt_nflen|opt->opt_flen))
1158 			opt = NULL;
1159 		connected = 0;
1160 	}
1161 	if (opt == NULL)
1162 		opt = np->opt;
1163 	if (flowlabel)
1164 		opt = fl6_merge_options(&opt_space, flowlabel, opt);
1165 	opt = ipv6_fixup_options(&opt_space, opt);
1166 
1167 	fl6.flowi6_proto = sk->sk_protocol;
1168 	if (!ipv6_addr_any(daddr))
1169 		fl6.daddr = *daddr;
1170 	else
1171 		fl6.daddr.s6_addr[15] = 0x1; /* :: means loopback (BSD'ism) */
1172 	if (ipv6_addr_any(&fl6.saddr) && !ipv6_addr_any(&np->saddr))
1173 		fl6.saddr = np->saddr;
1174 	fl6.fl6_sport = inet->inet_sport;
1175 
1176 	final_p = fl6_update_dst(&fl6, opt, &final);
1177 	if (final_p)
1178 		connected = 0;
1179 
1180 	if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr)) {
1181 		fl6.flowi6_oif = np->mcast_oif;
1182 		connected = 0;
1183 	} else if (!fl6.flowi6_oif)
1184 		fl6.flowi6_oif = np->ucast_oif;
1185 
1186 	security_sk_classify_flow(sk, flowi6_to_flowi(&fl6));
1187 
1188 	dst = ip6_sk_dst_lookup_flow(sk, &fl6, final_p, true);
1189 	if (IS_ERR(dst)) {
1190 		err = PTR_ERR(dst);
1191 		dst = NULL;
1192 		goto out;
1193 	}
1194 
1195 	if (hlimit < 0) {
1196 		if (ipv6_addr_is_multicast(&fl6.daddr))
1197 			hlimit = np->mcast_hops;
1198 		else
1199 			hlimit = np->hop_limit;
1200 		if (hlimit < 0)
1201 			hlimit = ip6_dst_hoplimit(dst);
1202 	}
1203 
1204 	if (tclass < 0)
1205 		tclass = np->tclass;
1206 
1207 	if (dontfrag < 0)
1208 		dontfrag = np->dontfrag;
1209 
1210 	if (msg->msg_flags&MSG_CONFIRM)
1211 		goto do_confirm;
1212 back_from_confirm:
1213 
1214 	lock_sock(sk);
1215 	if (unlikely(up->pending)) {
1216 		/* The socket is already corked while preparing it. */
1217 		/* ... which is an evident application bug. --ANK */
1218 		release_sock(sk);
1219 
1220 		LIMIT_NETDEBUG(KERN_DEBUG "udp cork app bug 2\n");
1221 		err = -EINVAL;
1222 		goto out;
1223 	}
1224 
1225 	up->pending = AF_INET6;
1226 
1227 do_append_data:
1228 	up->len += ulen;
1229 	getfrag  =  is_udplite ?  udplite_getfrag : ip_generic_getfrag;
1230 	err = ip6_append_data(sk, getfrag, msg->msg_iov, ulen,
1231 		sizeof(struct udphdr), hlimit, tclass, opt, &fl6,
1232 		(struct rt6_info*)dst,
1233 		corkreq ? msg->msg_flags|MSG_MORE : msg->msg_flags, dontfrag);
1234 	if (err)
1235 		udp_v6_flush_pending_frames(sk);
1236 	else if (!corkreq)
1237 		err = udp_v6_push_pending_frames(sk);
1238 	else if (unlikely(skb_queue_empty(&sk->sk_write_queue)))
1239 		up->pending = 0;
1240 
1241 	if (dst) {
1242 		if (connected) {
1243 			ip6_dst_store(sk, dst,
1244 				      ipv6_addr_equal(&fl6.daddr, &np->daddr) ?
1245 				      &np->daddr : NULL,
1246 #ifdef CONFIG_IPV6_SUBTREES
1247 				      ipv6_addr_equal(&fl6.saddr, &np->saddr) ?
1248 				      &np->saddr :
1249 #endif
1250 				      NULL);
1251 		} else {
1252 			dst_release(dst);
1253 		}
1254 		dst = NULL;
1255 	}
1256 
1257 	if (err > 0)
1258 		err = np->recverr ? net_xmit_errno(err) : 0;
1259 	release_sock(sk);
1260 out:
1261 	dst_release(dst);
1262 	fl6_sock_release(flowlabel);
1263 	if (!err)
1264 		return len;
1265 	/*
1266 	 * ENOBUFS = no kernel mem, SOCK_NOSPACE = no sndbuf space.  Reporting
1267 	 * ENOBUFS might not be good (it's not tunable per se), but otherwise
1268 	 * we don't have a good statistic (IpOutDiscards but it can be too many
1269 	 * things).  We could add another new stat but at least for now that
1270 	 * seems like overkill.
1271 	 */
1272 	if (err == -ENOBUFS || test_bit(SOCK_NOSPACE, &sk->sk_socket->flags)) {
1273 		UDP6_INC_STATS_USER(sock_net(sk),
1274 				UDP_MIB_SNDBUFERRORS, is_udplite);
1275 	}
1276 	return err;
1277 
1278 do_confirm:
1279 	dst_confirm(dst);
1280 	if (!(msg->msg_flags&MSG_PROBE) || len)
1281 		goto back_from_confirm;
1282 	err = 0;
1283 	goto out;
1284 }
1285 
1286 void udpv6_destroy_sock(struct sock *sk)
1287 {
1288 	lock_sock(sk);
1289 	udp_v6_flush_pending_frames(sk);
1290 	release_sock(sk);
1291 
1292 	inet6_destroy_sock(sk);
1293 }
1294 
1295 /*
1296  *	Socket option code for UDP
1297  */
1298 int udpv6_setsockopt(struct sock *sk, int level, int optname,
1299 		     char __user *optval, unsigned int optlen)
1300 {
1301 	if (level == SOL_UDP  ||  level == SOL_UDPLITE)
1302 		return udp_lib_setsockopt(sk, level, optname, optval, optlen,
1303 					  udp_v6_push_pending_frames);
1304 	return ipv6_setsockopt(sk, level, optname, optval, optlen);
1305 }
1306 
1307 #ifdef CONFIG_COMPAT
1308 int compat_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 compat_ipv6_setsockopt(sk, level, optname, optval, optlen);
1315 }
1316 #endif
1317 
1318 int udpv6_getsockopt(struct sock *sk, int level, int optname,
1319 		     char __user *optval, int __user *optlen)
1320 {
1321 	if (level == SOL_UDP  ||  level == SOL_UDPLITE)
1322 		return udp_lib_getsockopt(sk, level, optname, optval, optlen);
1323 	return ipv6_getsockopt(sk, level, optname, optval, optlen);
1324 }
1325 
1326 #ifdef CONFIG_COMPAT
1327 int compat_udpv6_getsockopt(struct sock *sk, int level, int optname,
1328 			    char __user *optval, int __user *optlen)
1329 {
1330 	if (level == SOL_UDP  ||  level == SOL_UDPLITE)
1331 		return udp_lib_getsockopt(sk, level, optname, optval, optlen);
1332 	return compat_ipv6_getsockopt(sk, level, optname, optval, optlen);
1333 }
1334 #endif
1335 
1336 static const struct inet6_protocol udpv6_protocol = {
1337 	.handler	=	udpv6_rcv,
1338 	.err_handler	=	udpv6_err,
1339 	.flags		=	INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
1340 };
1341 
1342 /* ------------------------------------------------------------------------ */
1343 #ifdef CONFIG_PROC_FS
1344 
1345 static void udp6_sock_seq_show(struct seq_file *seq, struct sock *sp, int bucket)
1346 {
1347 	struct inet_sock *inet = inet_sk(sp);
1348 	struct ipv6_pinfo *np = inet6_sk(sp);
1349 	const struct in6_addr *dest, *src;
1350 	__u16 destp, srcp;
1351 
1352 	dest  = &np->daddr;
1353 	src   = &np->rcv_saddr;
1354 	destp = ntohs(inet->inet_dport);
1355 	srcp  = ntohs(inet->inet_sport);
1356 	seq_printf(seq,
1357 		   "%5d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1358 		   "%02X %08X:%08X %02X:%08lX %08X %5d %8d %lu %d %pK %d\n",
1359 		   bucket,
1360 		   src->s6_addr32[0], src->s6_addr32[1],
1361 		   src->s6_addr32[2], src->s6_addr32[3], srcp,
1362 		   dest->s6_addr32[0], dest->s6_addr32[1],
1363 		   dest->s6_addr32[2], dest->s6_addr32[3], destp,
1364 		   sp->sk_state,
1365 		   sk_wmem_alloc_get(sp),
1366 		   sk_rmem_alloc_get(sp),
1367 		   0, 0L, 0,
1368 		   from_kuid_munged(seq_user_ns(seq), sock_i_uid(sp)),
1369 		   0,
1370 		   sock_i_ino(sp),
1371 		   atomic_read(&sp->sk_refcnt), sp,
1372 		   atomic_read(&sp->sk_drops));
1373 }
1374 
1375 int udp6_seq_show(struct seq_file *seq, void *v)
1376 {
1377 	if (v == SEQ_START_TOKEN)
1378 		seq_printf(seq,
1379 			   "  sl  "
1380 			   "local_address                         "
1381 			   "remote_address                        "
1382 			   "st tx_queue rx_queue tr tm->when retrnsmt"
1383 			   "   uid  timeout inode ref pointer drops\n");
1384 	else
1385 		udp6_sock_seq_show(seq, v, ((struct udp_iter_state *)seq->private)->bucket);
1386 	return 0;
1387 }
1388 
1389 static const struct file_operations udp6_afinfo_seq_fops = {
1390 	.owner    = THIS_MODULE,
1391 	.open     = udp_seq_open,
1392 	.read     = seq_read,
1393 	.llseek   = seq_lseek,
1394 	.release  = seq_release_net
1395 };
1396 
1397 static struct udp_seq_afinfo udp6_seq_afinfo = {
1398 	.name		= "udp6",
1399 	.family		= AF_INET6,
1400 	.udp_table	= &udp_table,
1401 	.seq_fops	= &udp6_afinfo_seq_fops,
1402 	.seq_ops	= {
1403 		.show		= udp6_seq_show,
1404 	},
1405 };
1406 
1407 int __net_init udp6_proc_init(struct net *net)
1408 {
1409 	return udp_proc_register(net, &udp6_seq_afinfo);
1410 }
1411 
1412 void udp6_proc_exit(struct net *net) {
1413 	udp_proc_unregister(net, &udp6_seq_afinfo);
1414 }
1415 #endif /* CONFIG_PROC_FS */
1416 
1417 /* ------------------------------------------------------------------------ */
1418 
1419 struct proto udpv6_prot = {
1420 	.name		   = "UDPv6",
1421 	.owner		   = THIS_MODULE,
1422 	.close		   = udp_lib_close,
1423 	.connect	   = ip6_datagram_connect,
1424 	.disconnect	   = udp_disconnect,
1425 	.ioctl		   = udp_ioctl,
1426 	.destroy	   = udpv6_destroy_sock,
1427 	.setsockopt	   = udpv6_setsockopt,
1428 	.getsockopt	   = udpv6_getsockopt,
1429 	.sendmsg	   = udpv6_sendmsg,
1430 	.recvmsg	   = udpv6_recvmsg,
1431 	.backlog_rcv	   = __udpv6_queue_rcv_skb,
1432 	.hash		   = udp_lib_hash,
1433 	.unhash		   = udp_lib_unhash,
1434 	.rehash		   = udp_v6_rehash,
1435 	.get_port	   = udp_v6_get_port,
1436 	.memory_allocated  = &udp_memory_allocated,
1437 	.sysctl_mem	   = sysctl_udp_mem,
1438 	.sysctl_wmem	   = &sysctl_udp_wmem_min,
1439 	.sysctl_rmem	   = &sysctl_udp_rmem_min,
1440 	.obj_size	   = sizeof(struct udp6_sock),
1441 	.slab_flags	   = SLAB_DESTROY_BY_RCU,
1442 	.h.udp_table	   = &udp_table,
1443 #ifdef CONFIG_COMPAT
1444 	.compat_setsockopt = compat_udpv6_setsockopt,
1445 	.compat_getsockopt = compat_udpv6_getsockopt,
1446 #endif
1447 	.clear_sk	   = sk_prot_clear_portaddr_nulls,
1448 };
1449 
1450 static struct inet_protosw udpv6_protosw = {
1451 	.type =      SOCK_DGRAM,
1452 	.protocol =  IPPROTO_UDP,
1453 	.prot =      &udpv6_prot,
1454 	.ops =       &inet6_dgram_ops,
1455 	.no_check =  UDP_CSUM_DEFAULT,
1456 	.flags =     INET_PROTOSW_PERMANENT,
1457 };
1458 
1459 
1460 int __init udpv6_init(void)
1461 {
1462 	int ret;
1463 
1464 	ret = inet6_add_protocol(&udpv6_protocol, IPPROTO_UDP);
1465 	if (ret)
1466 		goto out;
1467 
1468 	ret = inet6_register_protosw(&udpv6_protosw);
1469 	if (ret)
1470 		goto out_udpv6_protocol;
1471 out:
1472 	return ret;
1473 
1474 out_udpv6_protocol:
1475 	inet6_del_protocol(&udpv6_protocol, IPPROTO_UDP);
1476 	goto out;
1477 }
1478 
1479 void udpv6_exit(void)
1480 {
1481 	inet6_unregister_protosw(&udpv6_protosw);
1482 	inet6_del_protocol(&udpv6_protocol, IPPROTO_UDP);
1483 }
1484