xref: /openbmc/linux/net/ipv6/udp.c (revision 78c99ba1) 
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 <asm/uaccess.h>
38 
39 #include <net/ndisc.h>
40 #include <net/protocol.h>
41 #include <net/transp_v6.h>
42 #include <net/ip6_route.h>
43 #include <net/raw.h>
44 #include <net/tcp_states.h>
45 #include <net/ip6_checksum.h>
46 #include <net/xfrm.h>
47 
48 #include <linux/proc_fs.h>
49 #include <linux/seq_file.h>
50 #include "udp_impl.h"
51 
52 int ipv6_rcv_saddr_equal(const struct sock *sk, const struct sock *sk2)
53 {
54 	const struct in6_addr *sk_rcv_saddr6 = &inet6_sk(sk)->rcv_saddr;
55 	const struct in6_addr *sk2_rcv_saddr6 = inet6_rcv_saddr(sk2);
56 	__be32 sk_rcv_saddr = inet_sk(sk)->rcv_saddr;
57 	__be32 sk2_rcv_saddr = inet_rcv_saddr(sk2);
58 	int sk_ipv6only = ipv6_only_sock(sk);
59 	int sk2_ipv6only = inet_v6_ipv6only(sk2);
60 	int addr_type = ipv6_addr_type(sk_rcv_saddr6);
61 	int addr_type2 = sk2_rcv_saddr6 ? ipv6_addr_type(sk2_rcv_saddr6) : IPV6_ADDR_MAPPED;
62 
63 	/* if both are mapped, treat as IPv4 */
64 	if (addr_type == IPV6_ADDR_MAPPED && addr_type2 == IPV6_ADDR_MAPPED)
65 		return (!sk2_ipv6only &&
66 			(!sk_rcv_saddr || !sk2_rcv_saddr ||
67 			  sk_rcv_saddr == sk2_rcv_saddr));
68 
69 	if (addr_type2 == IPV6_ADDR_ANY &&
70 	    !(sk2_ipv6only && addr_type == IPV6_ADDR_MAPPED))
71 		return 1;
72 
73 	if (addr_type == IPV6_ADDR_ANY &&
74 	    !(sk_ipv6only && addr_type2 == IPV6_ADDR_MAPPED))
75 		return 1;
76 
77 	if (sk2_rcv_saddr6 &&
78 	    ipv6_addr_equal(sk_rcv_saddr6, sk2_rcv_saddr6))
79 		return 1;
80 
81 	return 0;
82 }
83 
84 int udp_v6_get_port(struct sock *sk, unsigned short snum)
85 {
86 	return udp_lib_get_port(sk, snum, ipv6_rcv_saddr_equal);
87 }
88 
89 static inline int compute_score(struct sock *sk, struct net *net,
90 				unsigned short hnum,
91 				struct in6_addr *saddr, __be16 sport,
92 				struct in6_addr *daddr, __be16 dport,
93 				int dif)
94 {
95 	int score = -1;
96 
97 	if (net_eq(sock_net(sk), net) && sk->sk_hash == hnum &&
98 			sk->sk_family == PF_INET6) {
99 		struct ipv6_pinfo *np = inet6_sk(sk);
100 		struct inet_sock *inet = inet_sk(sk);
101 
102 		score = 0;
103 		if (inet->dport) {
104 			if (inet->dport != sport)
105 				return -1;
106 			score++;
107 		}
108 		if (!ipv6_addr_any(&np->rcv_saddr)) {
109 			if (!ipv6_addr_equal(&np->rcv_saddr, daddr))
110 				return -1;
111 			score++;
112 		}
113 		if (!ipv6_addr_any(&np->daddr)) {
114 			if (!ipv6_addr_equal(&np->daddr, saddr))
115 				return -1;
116 			score++;
117 		}
118 		if (sk->sk_bound_dev_if) {
119 			if (sk->sk_bound_dev_if != dif)
120 				return -1;
121 			score++;
122 		}
123 	}
124 	return score;
125 }
126 
127 static struct sock *__udp6_lib_lookup(struct net *net,
128 				      struct in6_addr *saddr, __be16 sport,
129 				      struct in6_addr *daddr, __be16 dport,
130 				      int dif, struct udp_table *udptable)
131 {
132 	struct sock *sk, *result;
133 	struct hlist_nulls_node *node;
134 	unsigned short hnum = ntohs(dport);
135 	unsigned int hash = udp_hashfn(net, hnum);
136 	struct udp_hslot *hslot = &udptable->hash[hash];
137 	int score, badness;
138 
139 	rcu_read_lock();
140 begin:
141 	result = NULL;
142 	badness = -1;
143 	sk_nulls_for_each_rcu(sk, node, &hslot->head) {
144 		score = compute_score(sk, net, hnum, saddr, sport, daddr, dport, dif);
145 		if (score > badness) {
146 			result = sk;
147 			badness = score;
148 		}
149 	}
150 	/*
151 	 * if the nulls value we got at the end of this lookup is
152 	 * not the expected one, we must restart lookup.
153 	 * We probably met an item that was moved to another chain.
154 	 */
155 	if (get_nulls_value(node) != hash)
156 		goto begin;
157 
158 	if (result) {
159 		if (unlikely(!atomic_inc_not_zero(&result->sk_refcnt)))
160 			result = NULL;
161 		else if (unlikely(compute_score(result, net, hnum, saddr, sport,
162 					daddr, dport, dif) < badness)) {
163 			sock_put(result);
164 			goto begin;
165 		}
166 	}
167 	rcu_read_unlock();
168 	return result;
169 }
170 
171 static struct sock *__udp6_lib_lookup_skb(struct sk_buff *skb,
172 					  __be16 sport, __be16 dport,
173 					  struct udp_table *udptable)
174 {
175 	struct sock *sk;
176 	struct ipv6hdr *iph = ipv6_hdr(skb);
177 
178 	if (unlikely(sk = skb_steal_sock(skb)))
179 		return sk;
180 	else
181 		return __udp6_lib_lookup(dev_net(skb->dst->dev), &iph->saddr, sport,
182 					 &iph->daddr, dport, inet6_iif(skb),
183 					 udptable);
184 }
185 
186 /*
187  * 	This should be easy, if there is something there we
188  * 	return it, otherwise we block.
189  */
190 
191 int udpv6_recvmsg(struct kiocb *iocb, struct sock *sk,
192 		  struct msghdr *msg, size_t len,
193 		  int noblock, int flags, int *addr_len)
194 {
195 	struct ipv6_pinfo *np = inet6_sk(sk);
196 	struct inet_sock *inet = inet_sk(sk);
197 	struct sk_buff *skb;
198 	unsigned int ulen, copied;
199 	int peeked;
200 	int err;
201 	int is_udplite = IS_UDPLITE(sk);
202 	int is_udp4;
203 
204 	if (addr_len)
205 		*addr_len=sizeof(struct sockaddr_in6);
206 
207 	if (flags & MSG_ERRQUEUE)
208 		return ipv6_recv_error(sk, msg, len);
209 
210 try_again:
211 	skb = __skb_recv_datagram(sk, flags | (noblock ? MSG_DONTWAIT : 0),
212 				  &peeked, &err);
213 	if (!skb)
214 		goto out;
215 
216 	ulen = skb->len - sizeof(struct udphdr);
217 	copied = len;
218 	if (copied > ulen)
219 		copied = ulen;
220 	else if (copied < ulen)
221 		msg->msg_flags |= MSG_TRUNC;
222 
223 	is_udp4 = (skb->protocol == htons(ETH_P_IP));
224 
225 	/*
226 	 * If checksum is needed at all, try to do it while copying the
227 	 * data.  If the data is truncated, or if we only want a partial
228 	 * coverage checksum (UDP-Lite), do it before the copy.
229 	 */
230 
231 	if (copied < ulen || UDP_SKB_CB(skb)->partial_cov) {
232 		if (udp_lib_checksum_complete(skb))
233 			goto csum_copy_err;
234 	}
235 
236 	if (skb_csum_unnecessary(skb))
237 		err = skb_copy_datagram_iovec(skb, sizeof(struct udphdr),
238 					      msg->msg_iov, copied       );
239 	else {
240 		err = skb_copy_and_csum_datagram_iovec(skb, sizeof(struct udphdr), msg->msg_iov);
241 		if (err == -EINVAL)
242 			goto csum_copy_err;
243 	}
244 	if (err)
245 		goto out_free;
246 
247 	if (!peeked) {
248 		if (is_udp4)
249 			UDP_INC_STATS_USER(sock_net(sk),
250 					UDP_MIB_INDATAGRAMS, is_udplite);
251 		else
252 			UDP6_INC_STATS_USER(sock_net(sk),
253 					UDP_MIB_INDATAGRAMS, is_udplite);
254 	}
255 
256 	sock_recv_timestamp(msg, sk, skb);
257 
258 	/* Copy the address. */
259 	if (msg->msg_name) {
260 		struct sockaddr_in6 *sin6;
261 
262 		sin6 = (struct sockaddr_in6 *) msg->msg_name;
263 		sin6->sin6_family = AF_INET6;
264 		sin6->sin6_port = udp_hdr(skb)->source;
265 		sin6->sin6_flowinfo = 0;
266 		sin6->sin6_scope_id = 0;
267 
268 		if (is_udp4)
269 			ipv6_addr_set(&sin6->sin6_addr, 0, 0,
270 				      htonl(0xffff), ip_hdr(skb)->saddr);
271 		else {
272 			ipv6_addr_copy(&sin6->sin6_addr,
273 				       &ipv6_hdr(skb)->saddr);
274 			if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL)
275 				sin6->sin6_scope_id = IP6CB(skb)->iif;
276 		}
277 
278 	}
279 	if (is_udp4) {
280 		if (inet->cmsg_flags)
281 			ip_cmsg_recv(msg, skb);
282 	} else {
283 		if (np->rxopt.all)
284 			datagram_recv_ctl(sk, msg, skb);
285 	}
286 
287 	err = copied;
288 	if (flags & MSG_TRUNC)
289 		err = ulen;
290 
291 out_free:
292 	lock_sock(sk);
293 	skb_free_datagram(sk, skb);
294 	release_sock(sk);
295 out:
296 	return err;
297 
298 csum_copy_err:
299 	lock_sock(sk);
300 	if (!skb_kill_datagram(sk, skb, flags)) {
301 		if (is_udp4)
302 			UDP_INC_STATS_USER(sock_net(sk),
303 					UDP_MIB_INERRORS, is_udplite);
304 		else
305 			UDP6_INC_STATS_USER(sock_net(sk),
306 					UDP_MIB_INERRORS, is_udplite);
307 	}
308 	release_sock(sk);
309 
310 	if (flags & MSG_DONTWAIT)
311 		return -EAGAIN;
312 	goto try_again;
313 }
314 
315 void __udp6_lib_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
316 		    int type, int code, int offset, __be32 info,
317 		    struct udp_table *udptable)
318 {
319 	struct ipv6_pinfo *np;
320 	struct ipv6hdr *hdr = (struct ipv6hdr*)skb->data;
321 	struct in6_addr *saddr = &hdr->saddr;
322 	struct in6_addr *daddr = &hdr->daddr;
323 	struct udphdr *uh = (struct udphdr*)(skb->data+offset);
324 	struct sock *sk;
325 	int err;
326 
327 	sk = __udp6_lib_lookup(dev_net(skb->dev), daddr, uh->dest,
328 			       saddr, uh->source, inet6_iif(skb), udptable);
329 	if (sk == NULL)
330 		return;
331 
332 	np = inet6_sk(sk);
333 
334 	if (!icmpv6_err_convert(type, code, &err) && !np->recverr)
335 		goto out;
336 
337 	if (sk->sk_state != TCP_ESTABLISHED && !np->recverr)
338 		goto out;
339 
340 	if (np->recverr)
341 		ipv6_icmp_error(sk, skb, err, uh->dest, ntohl(info), (u8 *)(uh+1));
342 
343 	sk->sk_err = err;
344 	sk->sk_error_report(sk);
345 out:
346 	sock_put(sk);
347 }
348 
349 static __inline__ void udpv6_err(struct sk_buff *skb,
350 				 struct inet6_skb_parm *opt, int type,
351 				 int code, int offset, __be32 info     )
352 {
353 	__udp6_lib_err(skb, opt, type, code, offset, info, &udp_table);
354 }
355 
356 int udpv6_queue_rcv_skb(struct sock * sk, struct sk_buff *skb)
357 {
358 	struct udp_sock *up = udp_sk(sk);
359 	int rc;
360 	int is_udplite = IS_UDPLITE(sk);
361 
362 	if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
363 		goto drop;
364 
365 	/*
366 	 * UDP-Lite specific tests, ignored on UDP sockets (see net/ipv4/udp.c).
367 	 */
368 	if ((is_udplite & UDPLITE_RECV_CC)  &&  UDP_SKB_CB(skb)->partial_cov) {
369 
370 		if (up->pcrlen == 0) {          /* full coverage was set  */
371 			LIMIT_NETDEBUG(KERN_WARNING "UDPLITE6: partial coverage"
372 				" %d while full coverage %d requested\n",
373 				UDP_SKB_CB(skb)->cscov, skb->len);
374 			goto drop;
375 		}
376 		if (UDP_SKB_CB(skb)->cscov  <  up->pcrlen) {
377 			LIMIT_NETDEBUG(KERN_WARNING "UDPLITE6: coverage %d "
378 						    "too small, need min %d\n",
379 				       UDP_SKB_CB(skb)->cscov, up->pcrlen);
380 			goto drop;
381 		}
382 	}
383 
384 	if (sk->sk_filter) {
385 		if (udp_lib_checksum_complete(skb))
386 			goto drop;
387 	}
388 
389 	if ((rc = sock_queue_rcv_skb(sk,skb)) < 0) {
390 		/* Note that an ENOMEM error is charged twice */
391 		if (rc == -ENOMEM) {
392 			UDP6_INC_STATS_BH(sock_net(sk),
393 					UDP_MIB_RCVBUFERRORS, is_udplite);
394 			atomic_inc(&sk->sk_drops);
395 		}
396 		goto drop;
397 	}
398 
399 	return 0;
400 drop:
401 	UDP6_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
402 	kfree_skb(skb);
403 	return -1;
404 }
405 
406 static struct sock *udp_v6_mcast_next(struct net *net, struct sock *sk,
407 				      __be16 loc_port, struct in6_addr *loc_addr,
408 				      __be16 rmt_port, struct in6_addr *rmt_addr,
409 				      int dif)
410 {
411 	struct hlist_nulls_node *node;
412 	struct sock *s = sk;
413 	unsigned short num = ntohs(loc_port);
414 
415 	sk_nulls_for_each_from(s, node) {
416 		struct inet_sock *inet = inet_sk(s);
417 
418 		if (!net_eq(sock_net(s), net))
419 			continue;
420 
421 		if (s->sk_hash == num && s->sk_family == PF_INET6) {
422 			struct ipv6_pinfo *np = inet6_sk(s);
423 			if (inet->dport) {
424 				if (inet->dport != rmt_port)
425 					continue;
426 			}
427 			if (!ipv6_addr_any(&np->daddr) &&
428 			    !ipv6_addr_equal(&np->daddr, rmt_addr))
429 				continue;
430 
431 			if (s->sk_bound_dev_if && s->sk_bound_dev_if != dif)
432 				continue;
433 
434 			if (!ipv6_addr_any(&np->rcv_saddr)) {
435 				if (!ipv6_addr_equal(&np->rcv_saddr, loc_addr))
436 					continue;
437 			}
438 			if (!inet6_mc_check(s, loc_addr, rmt_addr))
439 				continue;
440 			return s;
441 		}
442 	}
443 	return NULL;
444 }
445 
446 /*
447  * Note: called only from the BH handler context,
448  * so we don't need to lock the hashes.
449  */
450 static int __udp6_lib_mcast_deliver(struct net *net, struct sk_buff *skb,
451 		struct in6_addr *saddr, struct in6_addr *daddr,
452 		struct udp_table *udptable)
453 {
454 	struct sock *sk, *sk2;
455 	const struct udphdr *uh = udp_hdr(skb);
456 	struct udp_hslot *hslot = &udptable->hash[udp_hashfn(net, ntohs(uh->dest))];
457 	int dif;
458 
459 	spin_lock(&hslot->lock);
460 	sk = sk_nulls_head(&hslot->head);
461 	dif = inet6_iif(skb);
462 	sk = udp_v6_mcast_next(net, sk, uh->dest, daddr, uh->source, saddr, dif);
463 	if (!sk) {
464 		kfree_skb(skb);
465 		goto out;
466 	}
467 
468 	sk2 = sk;
469 	while ((sk2 = udp_v6_mcast_next(net, sk_nulls_next(sk2), uh->dest, daddr,
470 					uh->source, saddr, dif))) {
471 		struct sk_buff *buff = skb_clone(skb, GFP_ATOMIC);
472 		if (buff) {
473 			bh_lock_sock(sk2);
474 			if (!sock_owned_by_user(sk2))
475 				udpv6_queue_rcv_skb(sk2, buff);
476 			else
477 				sk_add_backlog(sk2, buff);
478 			bh_unlock_sock(sk2);
479 		}
480 	}
481 	bh_lock_sock(sk);
482 	if (!sock_owned_by_user(sk))
483 		udpv6_queue_rcv_skb(sk, skb);
484 	else
485 		sk_add_backlog(sk, skb);
486 	bh_unlock_sock(sk);
487 out:
488 	spin_unlock(&hslot->lock);
489 	return 0;
490 }
491 
492 static inline int udp6_csum_init(struct sk_buff *skb, struct udphdr *uh,
493 				 int proto)
494 {
495 	int err;
496 
497 	UDP_SKB_CB(skb)->partial_cov = 0;
498 	UDP_SKB_CB(skb)->cscov = skb->len;
499 
500 	if (proto == IPPROTO_UDPLITE) {
501 		err = udplite_checksum_init(skb, uh);
502 		if (err)
503 			return err;
504 	}
505 
506 	if (uh->check == 0) {
507 		/* RFC 2460 section 8.1 says that we SHOULD log
508 		   this error. Well, it is reasonable.
509 		 */
510 		LIMIT_NETDEBUG(KERN_INFO "IPv6: udp checksum is 0\n");
511 		return 1;
512 	}
513 	if (skb->ip_summed == CHECKSUM_COMPLETE &&
514 	    !csum_ipv6_magic(&ipv6_hdr(skb)->saddr, &ipv6_hdr(skb)->daddr,
515 			     skb->len, proto, skb->csum))
516 		skb->ip_summed = CHECKSUM_UNNECESSARY;
517 
518 	if (!skb_csum_unnecessary(skb))
519 		skb->csum = ~csum_unfold(csum_ipv6_magic(&ipv6_hdr(skb)->saddr,
520 							 &ipv6_hdr(skb)->daddr,
521 							 skb->len, proto, 0));
522 
523 	return 0;
524 }
525 
526 int __udp6_lib_rcv(struct sk_buff *skb, struct udp_table *udptable,
527 		   int proto)
528 {
529 	struct sock *sk;
530 	struct udphdr *uh;
531 	struct net_device *dev = skb->dev;
532 	struct in6_addr *saddr, *daddr;
533 	u32 ulen = 0;
534 	struct net *net = dev_net(skb->dev);
535 
536 	if (!pskb_may_pull(skb, sizeof(struct udphdr)))
537 		goto short_packet;
538 
539 	saddr = &ipv6_hdr(skb)->saddr;
540 	daddr = &ipv6_hdr(skb)->daddr;
541 	uh = udp_hdr(skb);
542 
543 	ulen = ntohs(uh->len);
544 	if (ulen > skb->len)
545 		goto short_packet;
546 
547 	if (proto == IPPROTO_UDP) {
548 		/* UDP validates ulen. */
549 
550 		/* Check for jumbo payload */
551 		if (ulen == 0)
552 			ulen = skb->len;
553 
554 		if (ulen < sizeof(*uh))
555 			goto short_packet;
556 
557 		if (ulen < skb->len) {
558 			if (pskb_trim_rcsum(skb, ulen))
559 				goto short_packet;
560 			saddr = &ipv6_hdr(skb)->saddr;
561 			daddr = &ipv6_hdr(skb)->daddr;
562 			uh = udp_hdr(skb);
563 		}
564 	}
565 
566 	if (udp6_csum_init(skb, uh, proto))
567 		goto discard;
568 
569 	/*
570 	 *	Multicast receive code
571 	 */
572 	if (ipv6_addr_is_multicast(daddr))
573 		return __udp6_lib_mcast_deliver(net, skb,
574 				saddr, daddr, udptable);
575 
576 	/* Unicast */
577 
578 	/*
579 	 * check socket cache ... must talk to Alan about his plans
580 	 * for sock caches... i'll skip this for now.
581 	 */
582 	sk = __udp6_lib_lookup_skb(skb, uh->source, uh->dest, udptable);
583 
584 	if (sk == NULL) {
585 		if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
586 			goto discard;
587 
588 		if (udp_lib_checksum_complete(skb))
589 			goto discard;
590 		UDP6_INC_STATS_BH(net, UDP_MIB_NOPORTS,
591 				proto == IPPROTO_UDPLITE);
592 
593 		icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0, dev);
594 
595 		kfree_skb(skb);
596 		return 0;
597 	}
598 
599 	/* deliver */
600 
601 	bh_lock_sock(sk);
602 	if (!sock_owned_by_user(sk))
603 		udpv6_queue_rcv_skb(sk, skb);
604 	else
605 		sk_add_backlog(sk, skb);
606 	bh_unlock_sock(sk);
607 	sock_put(sk);
608 	return 0;
609 
610 short_packet:
611 	LIMIT_NETDEBUG(KERN_DEBUG "UDP%sv6: short packet: %d/%u\n",
612 		       proto == IPPROTO_UDPLITE ? "-Lite" : "",
613 		       ulen, skb->len);
614 
615 discard:
616 	UDP6_INC_STATS_BH(net, UDP_MIB_INERRORS, proto == IPPROTO_UDPLITE);
617 	kfree_skb(skb);
618 	return 0;
619 }
620 
621 static __inline__ int udpv6_rcv(struct sk_buff *skb)
622 {
623 	return __udp6_lib_rcv(skb, &udp_table, IPPROTO_UDP);
624 }
625 
626 /*
627  * Throw away all pending data and cancel the corking. Socket is locked.
628  */
629 static void udp_v6_flush_pending_frames(struct sock *sk)
630 {
631 	struct udp_sock *up = udp_sk(sk);
632 
633 	if (up->pending == AF_INET)
634 		udp_flush_pending_frames(sk);
635 	else if (up->pending) {
636 		up->len = 0;
637 		up->pending = 0;
638 		ip6_flush_pending_frames(sk);
639 	}
640 }
641 
642 /*
643  *	Sending
644  */
645 
646 static int udp_v6_push_pending_frames(struct sock *sk)
647 {
648 	struct sk_buff *skb;
649 	struct udphdr *uh;
650 	struct udp_sock  *up = udp_sk(sk);
651 	struct inet_sock *inet = inet_sk(sk);
652 	struct flowi *fl = &inet->cork.fl;
653 	int err = 0;
654 	int is_udplite = IS_UDPLITE(sk);
655 	__wsum csum = 0;
656 
657 	/* Grab the skbuff where UDP header space exists. */
658 	if ((skb = skb_peek(&sk->sk_write_queue)) == NULL)
659 		goto out;
660 
661 	/*
662 	 * Create a UDP header
663 	 */
664 	uh = udp_hdr(skb);
665 	uh->source = fl->fl_ip_sport;
666 	uh->dest = fl->fl_ip_dport;
667 	uh->len = htons(up->len);
668 	uh->check = 0;
669 
670 	if (is_udplite)
671 		csum = udplite_csum_outgoing(sk, skb);
672 	 else
673 		csum = udp_csum_outgoing(sk, skb);
674 
675 	/* add protocol-dependent pseudo-header */
676 	uh->check = csum_ipv6_magic(&fl->fl6_src, &fl->fl6_dst,
677 				    up->len, fl->proto, csum   );
678 	if (uh->check == 0)
679 		uh->check = CSUM_MANGLED_0;
680 
681 	err = ip6_push_pending_frames(sk);
682 out:
683 	up->len = 0;
684 	up->pending = 0;
685 	if (!err)
686 		UDP6_INC_STATS_USER(sock_net(sk),
687 				UDP_MIB_OUTDATAGRAMS, is_udplite);
688 	return err;
689 }
690 
691 int udpv6_sendmsg(struct kiocb *iocb, struct sock *sk,
692 		  struct msghdr *msg, size_t len)
693 {
694 	struct ipv6_txoptions opt_space;
695 	struct udp_sock *up = udp_sk(sk);
696 	struct inet_sock *inet = inet_sk(sk);
697 	struct ipv6_pinfo *np = inet6_sk(sk);
698 	struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *) msg->msg_name;
699 	struct in6_addr *daddr, *final_p = NULL, final;
700 	struct ipv6_txoptions *opt = NULL;
701 	struct ip6_flowlabel *flowlabel = NULL;
702 	struct flowi fl;
703 	struct dst_entry *dst;
704 	int addr_len = msg->msg_namelen;
705 	int ulen = len;
706 	int hlimit = -1;
707 	int tclass = -1;
708 	int corkreq = up->corkflag || msg->msg_flags&MSG_MORE;
709 	int err;
710 	int connected = 0;
711 	int is_udplite = IS_UDPLITE(sk);
712 	int (*getfrag)(void *, char *, int, int, int, struct sk_buff *);
713 
714 	/* destination address check */
715 	if (sin6) {
716 		if (addr_len < offsetof(struct sockaddr, sa_data))
717 			return -EINVAL;
718 
719 		switch (sin6->sin6_family) {
720 		case AF_INET6:
721 			if (addr_len < SIN6_LEN_RFC2133)
722 				return -EINVAL;
723 			daddr = &sin6->sin6_addr;
724 			break;
725 		case AF_INET:
726 			goto do_udp_sendmsg;
727 		case AF_UNSPEC:
728 			msg->msg_name = sin6 = NULL;
729 			msg->msg_namelen = addr_len = 0;
730 			daddr = NULL;
731 			break;
732 		default:
733 			return -EINVAL;
734 		}
735 	} else if (!up->pending) {
736 		if (sk->sk_state != TCP_ESTABLISHED)
737 			return -EDESTADDRREQ;
738 		daddr = &np->daddr;
739 	} else
740 		daddr = NULL;
741 
742 	if (daddr) {
743 		if (ipv6_addr_v4mapped(daddr)) {
744 			struct sockaddr_in sin;
745 			sin.sin_family = AF_INET;
746 			sin.sin_port = sin6 ? sin6->sin6_port : inet->dport;
747 			sin.sin_addr.s_addr = daddr->s6_addr32[3];
748 			msg->msg_name = &sin;
749 			msg->msg_namelen = sizeof(sin);
750 do_udp_sendmsg:
751 			if (__ipv6_only_sock(sk))
752 				return -ENETUNREACH;
753 			return udp_sendmsg(iocb, sk, msg, len);
754 		}
755 	}
756 
757 	if (up->pending == AF_INET)
758 		return udp_sendmsg(iocb, sk, msg, len);
759 
760 	/* Rough check on arithmetic overflow,
761 	   better check is made in ip6_append_data().
762 	   */
763 	if (len > INT_MAX - sizeof(struct udphdr))
764 		return -EMSGSIZE;
765 
766 	if (up->pending) {
767 		/*
768 		 * There are pending frames.
769 		 * The socket lock must be held while it's corked.
770 		 */
771 		lock_sock(sk);
772 		if (likely(up->pending)) {
773 			if (unlikely(up->pending != AF_INET6)) {
774 				release_sock(sk);
775 				return -EAFNOSUPPORT;
776 			}
777 			dst = NULL;
778 			goto do_append_data;
779 		}
780 		release_sock(sk);
781 	}
782 	ulen += sizeof(struct udphdr);
783 
784 	memset(&fl, 0, sizeof(fl));
785 
786 	if (sin6) {
787 		if (sin6->sin6_port == 0)
788 			return -EINVAL;
789 
790 		fl.fl_ip_dport = sin6->sin6_port;
791 		daddr = &sin6->sin6_addr;
792 
793 		if (np->sndflow) {
794 			fl.fl6_flowlabel = sin6->sin6_flowinfo&IPV6_FLOWINFO_MASK;
795 			if (fl.fl6_flowlabel&IPV6_FLOWLABEL_MASK) {
796 				flowlabel = fl6_sock_lookup(sk, fl.fl6_flowlabel);
797 				if (flowlabel == NULL)
798 					return -EINVAL;
799 				daddr = &flowlabel->dst;
800 			}
801 		}
802 
803 		/*
804 		 * Otherwise it will be difficult to maintain
805 		 * sk->sk_dst_cache.
806 		 */
807 		if (sk->sk_state == TCP_ESTABLISHED &&
808 		    ipv6_addr_equal(daddr, &np->daddr))
809 			daddr = &np->daddr;
810 
811 		if (addr_len >= sizeof(struct sockaddr_in6) &&
812 		    sin6->sin6_scope_id &&
813 		    ipv6_addr_type(daddr)&IPV6_ADDR_LINKLOCAL)
814 			fl.oif = sin6->sin6_scope_id;
815 	} else {
816 		if (sk->sk_state != TCP_ESTABLISHED)
817 			return -EDESTADDRREQ;
818 
819 		fl.fl_ip_dport = inet->dport;
820 		daddr = &np->daddr;
821 		fl.fl6_flowlabel = np->flow_label;
822 		connected = 1;
823 	}
824 
825 	if (!fl.oif)
826 		fl.oif = sk->sk_bound_dev_if;
827 
828 	if (!fl.oif)
829 		fl.oif = np->sticky_pktinfo.ipi6_ifindex;
830 
831 	if (msg->msg_controllen) {
832 		opt = &opt_space;
833 		memset(opt, 0, sizeof(struct ipv6_txoptions));
834 		opt->tot_len = sizeof(*opt);
835 
836 		err = datagram_send_ctl(sock_net(sk), msg, &fl, opt, &hlimit, &tclass);
837 		if (err < 0) {
838 			fl6_sock_release(flowlabel);
839 			return err;
840 		}
841 		if ((fl.fl6_flowlabel&IPV6_FLOWLABEL_MASK) && !flowlabel) {
842 			flowlabel = fl6_sock_lookup(sk, fl.fl6_flowlabel);
843 			if (flowlabel == NULL)
844 				return -EINVAL;
845 		}
846 		if (!(opt->opt_nflen|opt->opt_flen))
847 			opt = NULL;
848 		connected = 0;
849 	}
850 	if (opt == NULL)
851 		opt = np->opt;
852 	if (flowlabel)
853 		opt = fl6_merge_options(&opt_space, flowlabel, opt);
854 	opt = ipv6_fixup_options(&opt_space, opt);
855 
856 	fl.proto = sk->sk_protocol;
857 	if (!ipv6_addr_any(daddr))
858 		ipv6_addr_copy(&fl.fl6_dst, daddr);
859 	else
860 		fl.fl6_dst.s6_addr[15] = 0x1; /* :: means loopback (BSD'ism) */
861 	if (ipv6_addr_any(&fl.fl6_src) && !ipv6_addr_any(&np->saddr))
862 		ipv6_addr_copy(&fl.fl6_src, &np->saddr);
863 	fl.fl_ip_sport = inet->sport;
864 
865 	/* merge ip6_build_xmit from ip6_output */
866 	if (opt && opt->srcrt) {
867 		struct rt0_hdr *rt0 = (struct rt0_hdr *) opt->srcrt;
868 		ipv6_addr_copy(&final, &fl.fl6_dst);
869 		ipv6_addr_copy(&fl.fl6_dst, rt0->addr);
870 		final_p = &final;
871 		connected = 0;
872 	}
873 
874 	if (!fl.oif && ipv6_addr_is_multicast(&fl.fl6_dst)) {
875 		fl.oif = np->mcast_oif;
876 		connected = 0;
877 	}
878 
879 	security_sk_classify_flow(sk, &fl);
880 
881 	err = ip6_sk_dst_lookup(sk, &dst, &fl);
882 	if (err)
883 		goto out;
884 	if (final_p)
885 		ipv6_addr_copy(&fl.fl6_dst, final_p);
886 
887 	err = __xfrm_lookup(sock_net(sk), &dst, &fl, sk, XFRM_LOOKUP_WAIT);
888 	if (err < 0) {
889 		if (err == -EREMOTE)
890 			err = ip6_dst_blackhole(sk, &dst, &fl);
891 		if (err < 0)
892 			goto out;
893 	}
894 
895 	if (hlimit < 0) {
896 		if (ipv6_addr_is_multicast(&fl.fl6_dst))
897 			hlimit = np->mcast_hops;
898 		else
899 			hlimit = np->hop_limit;
900 		if (hlimit < 0)
901 			hlimit = ip6_dst_hoplimit(dst);
902 	}
903 
904 	if (tclass < 0) {
905 		tclass = np->tclass;
906 		if (tclass < 0)
907 			tclass = 0;
908 	}
909 
910 	if (msg->msg_flags&MSG_CONFIRM)
911 		goto do_confirm;
912 back_from_confirm:
913 
914 	lock_sock(sk);
915 	if (unlikely(up->pending)) {
916 		/* The socket is already corked while preparing it. */
917 		/* ... which is an evident application bug. --ANK */
918 		release_sock(sk);
919 
920 		LIMIT_NETDEBUG(KERN_DEBUG "udp cork app bug 2\n");
921 		err = -EINVAL;
922 		goto out;
923 	}
924 
925 	up->pending = AF_INET6;
926 
927 do_append_data:
928 	up->len += ulen;
929 	getfrag  =  is_udplite ?  udplite_getfrag : ip_generic_getfrag;
930 	err = ip6_append_data(sk, getfrag, msg->msg_iov, ulen,
931 		sizeof(struct udphdr), hlimit, tclass, opt, &fl,
932 		(struct rt6_info*)dst,
933 		corkreq ? msg->msg_flags|MSG_MORE : msg->msg_flags);
934 	if (err)
935 		udp_v6_flush_pending_frames(sk);
936 	else if (!corkreq)
937 		err = udp_v6_push_pending_frames(sk);
938 	else if (unlikely(skb_queue_empty(&sk->sk_write_queue)))
939 		up->pending = 0;
940 
941 	if (dst) {
942 		if (connected) {
943 			ip6_dst_store(sk, dst,
944 				      ipv6_addr_equal(&fl.fl6_dst, &np->daddr) ?
945 				      &np->daddr : NULL,
946 #ifdef CONFIG_IPV6_SUBTREES
947 				      ipv6_addr_equal(&fl.fl6_src, &np->saddr) ?
948 				      &np->saddr :
949 #endif
950 				      NULL);
951 		} else {
952 			dst_release(dst);
953 		}
954 		dst = NULL;
955 	}
956 
957 	if (err > 0)
958 		err = np->recverr ? net_xmit_errno(err) : 0;
959 	release_sock(sk);
960 out:
961 	dst_release(dst);
962 	fl6_sock_release(flowlabel);
963 	if (!err)
964 		return len;
965 	/*
966 	 * ENOBUFS = no kernel mem, SOCK_NOSPACE = no sndbuf space.  Reporting
967 	 * ENOBUFS might not be good (it's not tunable per se), but otherwise
968 	 * we don't have a good statistic (IpOutDiscards but it can be too many
969 	 * things).  We could add another new stat but at least for now that
970 	 * seems like overkill.
971 	 */
972 	if (err == -ENOBUFS || test_bit(SOCK_NOSPACE, &sk->sk_socket->flags)) {
973 		UDP6_INC_STATS_USER(sock_net(sk),
974 				UDP_MIB_SNDBUFERRORS, is_udplite);
975 	}
976 	return err;
977 
978 do_confirm:
979 	dst_confirm(dst);
980 	if (!(msg->msg_flags&MSG_PROBE) || len)
981 		goto back_from_confirm;
982 	err = 0;
983 	goto out;
984 }
985 
986 void udpv6_destroy_sock(struct sock *sk)
987 {
988 	lock_sock(sk);
989 	udp_v6_flush_pending_frames(sk);
990 	release_sock(sk);
991 
992 	inet6_destroy_sock(sk);
993 }
994 
995 /*
996  *	Socket option code for UDP
997  */
998 int udpv6_setsockopt(struct sock *sk, int level, int optname,
999 		     char __user *optval, int optlen)
1000 {
1001 	if (level == SOL_UDP  ||  level == SOL_UDPLITE)
1002 		return udp_lib_setsockopt(sk, level, optname, optval, optlen,
1003 					  udp_v6_push_pending_frames);
1004 	return ipv6_setsockopt(sk, level, optname, optval, optlen);
1005 }
1006 
1007 #ifdef CONFIG_COMPAT
1008 int compat_udpv6_setsockopt(struct sock *sk, int level, int optname,
1009 			    char __user *optval, int optlen)
1010 {
1011 	if (level == SOL_UDP  ||  level == SOL_UDPLITE)
1012 		return udp_lib_setsockopt(sk, level, optname, optval, optlen,
1013 					  udp_v6_push_pending_frames);
1014 	return compat_ipv6_setsockopt(sk, level, optname, optval, optlen);
1015 }
1016 #endif
1017 
1018 int udpv6_getsockopt(struct sock *sk, int level, int optname,
1019 		     char __user *optval, int __user *optlen)
1020 {
1021 	if (level == SOL_UDP  ||  level == SOL_UDPLITE)
1022 		return udp_lib_getsockopt(sk, level, optname, optval, optlen);
1023 	return ipv6_getsockopt(sk, level, optname, optval, optlen);
1024 }
1025 
1026 #ifdef CONFIG_COMPAT
1027 int compat_udpv6_getsockopt(struct sock *sk, int level, int optname,
1028 			    char __user *optval, int __user *optlen)
1029 {
1030 	if (level == SOL_UDP  ||  level == SOL_UDPLITE)
1031 		return udp_lib_getsockopt(sk, level, optname, optval, optlen);
1032 	return compat_ipv6_getsockopt(sk, level, optname, optval, optlen);
1033 }
1034 #endif
1035 
1036 static struct inet6_protocol udpv6_protocol = {
1037 	.handler	=	udpv6_rcv,
1038 	.err_handler	=	udpv6_err,
1039 	.flags		=	INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
1040 };
1041 
1042 /* ------------------------------------------------------------------------ */
1043 #ifdef CONFIG_PROC_FS
1044 
1045 static void udp6_sock_seq_show(struct seq_file *seq, struct sock *sp, int bucket)
1046 {
1047 	struct inet_sock *inet = inet_sk(sp);
1048 	struct ipv6_pinfo *np = inet6_sk(sp);
1049 	struct in6_addr *dest, *src;
1050 	__u16 destp, srcp;
1051 
1052 	dest  = &np->daddr;
1053 	src   = &np->rcv_saddr;
1054 	destp = ntohs(inet->dport);
1055 	srcp  = ntohs(inet->sport);
1056 	seq_printf(seq,
1057 		   "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1058 		   "%02X %08X:%08X %02X:%08lX %08X %5d %8d %lu %d %p %d\n",
1059 		   bucket,
1060 		   src->s6_addr32[0], src->s6_addr32[1],
1061 		   src->s6_addr32[2], src->s6_addr32[3], srcp,
1062 		   dest->s6_addr32[0], dest->s6_addr32[1],
1063 		   dest->s6_addr32[2], dest->s6_addr32[3], destp,
1064 		   sp->sk_state,
1065 		   atomic_read(&sp->sk_wmem_alloc),
1066 		   atomic_read(&sp->sk_rmem_alloc),
1067 		   0, 0L, 0,
1068 		   sock_i_uid(sp), 0,
1069 		   sock_i_ino(sp),
1070 		   atomic_read(&sp->sk_refcnt), sp,
1071 		   atomic_read(&sp->sk_drops));
1072 }
1073 
1074 int udp6_seq_show(struct seq_file *seq, void *v)
1075 {
1076 	if (v == SEQ_START_TOKEN)
1077 		seq_printf(seq,
1078 			   "  sl  "
1079 			   "local_address                         "
1080 			   "remote_address                        "
1081 			   "st tx_queue rx_queue tr tm->when retrnsmt"
1082 			   "   uid  timeout inode ref pointer drops\n");
1083 	else
1084 		udp6_sock_seq_show(seq, v, ((struct udp_iter_state *)seq->private)->bucket);
1085 	return 0;
1086 }
1087 
1088 static struct udp_seq_afinfo udp6_seq_afinfo = {
1089 	.name		= "udp6",
1090 	.family		= AF_INET6,
1091 	.udp_table	= &udp_table,
1092 	.seq_fops	= {
1093 		.owner	=	THIS_MODULE,
1094 	},
1095 	.seq_ops	= {
1096 		.show		= udp6_seq_show,
1097 	},
1098 };
1099 
1100 int udp6_proc_init(struct net *net)
1101 {
1102 	return udp_proc_register(net, &udp6_seq_afinfo);
1103 }
1104 
1105 void udp6_proc_exit(struct net *net) {
1106 	udp_proc_unregister(net, &udp6_seq_afinfo);
1107 }
1108 #endif /* CONFIG_PROC_FS */
1109 
1110 /* ------------------------------------------------------------------------ */
1111 
1112 struct proto udpv6_prot = {
1113 	.name		   = "UDPv6",
1114 	.owner		   = THIS_MODULE,
1115 	.close		   = udp_lib_close,
1116 	.connect	   = ip6_datagram_connect,
1117 	.disconnect	   = udp_disconnect,
1118 	.ioctl		   = udp_ioctl,
1119 	.destroy	   = udpv6_destroy_sock,
1120 	.setsockopt	   = udpv6_setsockopt,
1121 	.getsockopt	   = udpv6_getsockopt,
1122 	.sendmsg	   = udpv6_sendmsg,
1123 	.recvmsg	   = udpv6_recvmsg,
1124 	.backlog_rcv	   = udpv6_queue_rcv_skb,
1125 	.hash		   = udp_lib_hash,
1126 	.unhash		   = udp_lib_unhash,
1127 	.get_port	   = udp_v6_get_port,
1128 	.memory_allocated  = &udp_memory_allocated,
1129 	.sysctl_mem	   = sysctl_udp_mem,
1130 	.sysctl_wmem	   = &sysctl_udp_wmem_min,
1131 	.sysctl_rmem	   = &sysctl_udp_rmem_min,
1132 	.obj_size	   = sizeof(struct udp6_sock),
1133 	.slab_flags	   = SLAB_DESTROY_BY_RCU,
1134 	.h.udp_table	   = &udp_table,
1135 #ifdef CONFIG_COMPAT
1136 	.compat_setsockopt = compat_udpv6_setsockopt,
1137 	.compat_getsockopt = compat_udpv6_getsockopt,
1138 #endif
1139 };
1140 
1141 static struct inet_protosw udpv6_protosw = {
1142 	.type =      SOCK_DGRAM,
1143 	.protocol =  IPPROTO_UDP,
1144 	.prot =      &udpv6_prot,
1145 	.ops =       &inet6_dgram_ops,
1146 	.capability =-1,
1147 	.no_check =  UDP_CSUM_DEFAULT,
1148 	.flags =     INET_PROTOSW_PERMANENT,
1149 };
1150 
1151 
1152 int __init udpv6_init(void)
1153 {
1154 	int ret;
1155 
1156 	ret = inet6_add_protocol(&udpv6_protocol, IPPROTO_UDP);
1157 	if (ret)
1158 		goto out;
1159 
1160 	ret = inet6_register_protosw(&udpv6_protosw);
1161 	if (ret)
1162 		goto out_udpv6_protocol;
1163 out:
1164 	return ret;
1165 
1166 out_udpv6_protocol:
1167 	inet6_del_protocol(&udpv6_protocol, IPPROTO_UDP);
1168 	goto out;
1169 }
1170 
1171 void udpv6_exit(void)
1172 {
1173 	inet6_unregister_protosw(&udpv6_protosw);
1174 	inet6_del_protocol(&udpv6_protocol, IPPROTO_UDP);
1175 }
1176