xref: /openbmc/linux/net/ipv6/udp.c (revision a1e58bbd)
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  *	$Id: udp.c,v 1.65 2002/02/01 22:01:04 davem Exp $
11  *
12  *	Fixes:
13  *	Hideaki YOSHIFUJI	:	sin6_scope_id support
14  *	YOSHIFUJI Hideaki @USAGI and:	Support IPV6_V6ONLY socket option, which
15  *	Alexey Kuznetsov		allow both IPv4 and IPv6 sockets to bind
16  *					a single port at the same time.
17  *      Kazunori MIYAZAWA @USAGI:       change process style to use ip6_append_data
18  *      YOSHIFUJI Hideaki @USAGI:	convert /proc/net/udp6 to seq_file.
19  *
20  *	This program is free software; you can redistribute it and/or
21  *      modify it under the terms of the GNU General Public License
22  *      as published by the Free Software Foundation; either version
23  *      2 of the License, or (at your option) any later version.
24  */
25 
26 #include <linux/errno.h>
27 #include <linux/types.h>
28 #include <linux/socket.h>
29 #include <linux/sockios.h>
30 #include <linux/net.h>
31 #include <linux/in6.h>
32 #include <linux/netdevice.h>
33 #include <linux/if_arp.h>
34 #include <linux/ipv6.h>
35 #include <linux/icmpv6.h>
36 #include <linux/init.h>
37 #include <linux/module.h>
38 #include <linux/skbuff.h>
39 #include <asm/uaccess.h>
40 
41 #include <net/ndisc.h>
42 #include <net/protocol.h>
43 #include <net/transp_v6.h>
44 #include <net/ip6_route.h>
45 #include <net/raw.h>
46 #include <net/tcp_states.h>
47 #include <net/ip6_checksum.h>
48 #include <net/xfrm.h>
49 
50 #include <linux/proc_fs.h>
51 #include <linux/seq_file.h>
52 #include "udp_impl.h"
53 
54 static inline int udp_v6_get_port(struct sock *sk, unsigned short snum)
55 {
56 	return udp_get_port(sk, snum, ipv6_rcv_saddr_equal);
57 }
58 
59 static struct sock *__udp6_lib_lookup(struct net *net,
60 				      struct in6_addr *saddr, __be16 sport,
61 				      struct in6_addr *daddr, __be16 dport,
62 				      int dif, struct hlist_head udptable[])
63 {
64 	struct sock *sk, *result = NULL;
65 	struct hlist_node *node;
66 	unsigned short hnum = ntohs(dport);
67 	int badness = -1;
68 
69 	read_lock(&udp_hash_lock);
70 	sk_for_each(sk, node, &udptable[hnum & (UDP_HTABLE_SIZE - 1)]) {
71 		struct inet_sock *inet = inet_sk(sk);
72 
73 		if (sk->sk_net == net && sk->sk_hash == hnum &&
74 				sk->sk_family == PF_INET6) {
75 			struct ipv6_pinfo *np = inet6_sk(sk);
76 			int score = 0;
77 			if (inet->dport) {
78 				if (inet->dport != sport)
79 					continue;
80 				score++;
81 			}
82 			if (!ipv6_addr_any(&np->rcv_saddr)) {
83 				if (!ipv6_addr_equal(&np->rcv_saddr, daddr))
84 					continue;
85 				score++;
86 			}
87 			if (!ipv6_addr_any(&np->daddr)) {
88 				if (!ipv6_addr_equal(&np->daddr, saddr))
89 					continue;
90 				score++;
91 			}
92 			if (sk->sk_bound_dev_if) {
93 				if (sk->sk_bound_dev_if != dif)
94 					continue;
95 				score++;
96 			}
97 			if (score == 4) {
98 				result = sk;
99 				break;
100 			} else if (score > badness) {
101 				result = sk;
102 				badness = score;
103 			}
104 		}
105 	}
106 	if (result)
107 		sock_hold(result);
108 	read_unlock(&udp_hash_lock);
109 	return result;
110 }
111 
112 /*
113  * 	This should be easy, if there is something there we
114  * 	return it, otherwise we block.
115  */
116 
117 int udpv6_recvmsg(struct kiocb *iocb, struct sock *sk,
118 		  struct msghdr *msg, size_t len,
119 		  int noblock, int flags, int *addr_len)
120 {
121 	struct ipv6_pinfo *np = inet6_sk(sk);
122 	struct inet_sock *inet = inet_sk(sk);
123 	struct sk_buff *skb;
124 	unsigned int ulen, copied;
125 	int peeked;
126 	int err;
127 	int is_udplite = IS_UDPLITE(sk);
128 
129 	if (addr_len)
130 		*addr_len=sizeof(struct sockaddr_in6);
131 
132 	if (flags & MSG_ERRQUEUE)
133 		return ipv6_recv_error(sk, msg, len);
134 
135 try_again:
136 	skb = __skb_recv_datagram(sk, flags | (noblock ? MSG_DONTWAIT : 0),
137 				  &peeked, &err);
138 	if (!skb)
139 		goto out;
140 
141 	ulen = skb->len - sizeof(struct udphdr);
142 	copied = len;
143 	if (copied > ulen)
144 		copied = ulen;
145 	else if (copied < ulen)
146 		msg->msg_flags |= MSG_TRUNC;
147 
148 	/*
149 	 * If checksum is needed at all, try to do it while copying the
150 	 * data.  If the data is truncated, or if we only want a partial
151 	 * coverage checksum (UDP-Lite), do it before the copy.
152 	 */
153 
154 	if (copied < ulen || UDP_SKB_CB(skb)->partial_cov) {
155 		if (udp_lib_checksum_complete(skb))
156 			goto csum_copy_err;
157 	}
158 
159 	if (skb_csum_unnecessary(skb))
160 		err = skb_copy_datagram_iovec(skb, sizeof(struct udphdr),
161 					      msg->msg_iov, copied       );
162 	else {
163 		err = skb_copy_and_csum_datagram_iovec(skb, sizeof(struct udphdr), msg->msg_iov);
164 		if (err == -EINVAL)
165 			goto csum_copy_err;
166 	}
167 	if (err)
168 		goto out_free;
169 
170 	if (!peeked)
171 		UDP6_INC_STATS_USER(UDP_MIB_INDATAGRAMS, is_udplite);
172 
173 	sock_recv_timestamp(msg, sk, skb);
174 
175 	/* Copy the address. */
176 	if (msg->msg_name) {
177 		struct sockaddr_in6 *sin6;
178 
179 		sin6 = (struct sockaddr_in6 *) msg->msg_name;
180 		sin6->sin6_family = AF_INET6;
181 		sin6->sin6_port = udp_hdr(skb)->source;
182 		sin6->sin6_flowinfo = 0;
183 		sin6->sin6_scope_id = 0;
184 
185 		if (skb->protocol == htons(ETH_P_IP))
186 			ipv6_addr_set(&sin6->sin6_addr, 0, 0,
187 				      htonl(0xffff), ip_hdr(skb)->saddr);
188 		else {
189 			ipv6_addr_copy(&sin6->sin6_addr,
190 				       &ipv6_hdr(skb)->saddr);
191 			if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL)
192 				sin6->sin6_scope_id = IP6CB(skb)->iif;
193 		}
194 
195 	}
196 	if (skb->protocol == htons(ETH_P_IP)) {
197 		if (inet->cmsg_flags)
198 			ip_cmsg_recv(msg, skb);
199 	} else {
200 		if (np->rxopt.all)
201 			datagram_recv_ctl(sk, msg, skb);
202 	}
203 
204 	err = copied;
205 	if (flags & MSG_TRUNC)
206 		err = ulen;
207 
208 out_free:
209 	lock_sock(sk);
210 	skb_free_datagram(sk, skb);
211 	release_sock(sk);
212 out:
213 	return err;
214 
215 csum_copy_err:
216 	lock_sock(sk);
217 	if (!skb_kill_datagram(sk, skb, flags))
218 		UDP6_INC_STATS_USER(UDP_MIB_INERRORS, is_udplite);
219 	release_sock(sk);
220 
221 	if (flags & MSG_DONTWAIT)
222 		return -EAGAIN;
223 	goto try_again;
224 }
225 
226 void __udp6_lib_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
227 		    int type, int code, int offset, __be32 info,
228 		    struct hlist_head udptable[]                    )
229 {
230 	struct ipv6_pinfo *np;
231 	struct ipv6hdr *hdr = (struct ipv6hdr*)skb->data;
232 	struct in6_addr *saddr = &hdr->saddr;
233 	struct in6_addr *daddr = &hdr->daddr;
234 	struct udphdr *uh = (struct udphdr*)(skb->data+offset);
235 	struct sock *sk;
236 	int err;
237 
238 	sk = __udp6_lib_lookup(skb->dev->nd_net, daddr, uh->dest,
239 			       saddr, uh->source, inet6_iif(skb), udptable);
240 	if (sk == NULL)
241 		return;
242 
243 	np = inet6_sk(sk);
244 
245 	if (!icmpv6_err_convert(type, code, &err) && !np->recverr)
246 		goto out;
247 
248 	if (sk->sk_state != TCP_ESTABLISHED && !np->recverr)
249 		goto out;
250 
251 	if (np->recverr)
252 		ipv6_icmp_error(sk, skb, err, uh->dest, ntohl(info), (u8 *)(uh+1));
253 
254 	sk->sk_err = err;
255 	sk->sk_error_report(sk);
256 out:
257 	sock_put(sk);
258 }
259 
260 static __inline__ void udpv6_err(struct sk_buff *skb,
261 				 struct inet6_skb_parm *opt, int type,
262 				 int code, int offset, __be32 info     )
263 {
264 	__udp6_lib_err(skb, opt, type, code, offset, info, udp_hash);
265 }
266 
267 int udpv6_queue_rcv_skb(struct sock * sk, struct sk_buff *skb)
268 {
269 	struct udp_sock *up = udp_sk(sk);
270 	int rc;
271 	int is_udplite = IS_UDPLITE(sk);
272 
273 	if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
274 		goto drop;
275 
276 	/*
277 	 * UDP-Lite specific tests, ignored on UDP sockets (see net/ipv4/udp.c).
278 	 */
279 	if ((is_udplite & UDPLITE_RECV_CC)  &&  UDP_SKB_CB(skb)->partial_cov) {
280 
281 		if (up->pcrlen == 0) {          /* full coverage was set  */
282 			LIMIT_NETDEBUG(KERN_WARNING "UDPLITE6: partial coverage"
283 				" %d while full coverage %d requested\n",
284 				UDP_SKB_CB(skb)->cscov, skb->len);
285 			goto drop;
286 		}
287 		if (UDP_SKB_CB(skb)->cscov  <  up->pcrlen) {
288 			LIMIT_NETDEBUG(KERN_WARNING "UDPLITE6: coverage %d "
289 						    "too small, need min %d\n",
290 				       UDP_SKB_CB(skb)->cscov, up->pcrlen);
291 			goto drop;
292 		}
293 	}
294 
295 	if (sk->sk_filter) {
296 		if (udp_lib_checksum_complete(skb))
297 			goto drop;
298 	}
299 
300 	if ((rc = sock_queue_rcv_skb(sk,skb)) < 0) {
301 		/* Note that an ENOMEM error is charged twice */
302 		if (rc == -ENOMEM)
303 			UDP6_INC_STATS_BH(UDP_MIB_RCVBUFERRORS, is_udplite);
304 		goto drop;
305 	}
306 
307 	return 0;
308 drop:
309 	UDP6_INC_STATS_BH(UDP_MIB_INERRORS, is_udplite);
310 	kfree_skb(skb);
311 	return -1;
312 }
313 
314 static struct sock *udp_v6_mcast_next(struct sock *sk,
315 				      __be16 loc_port, struct in6_addr *loc_addr,
316 				      __be16 rmt_port, struct in6_addr *rmt_addr,
317 				      int dif)
318 {
319 	struct hlist_node *node;
320 	struct sock *s = sk;
321 	unsigned short num = ntohs(loc_port);
322 
323 	sk_for_each_from(s, node) {
324 		struct inet_sock *inet = inet_sk(s);
325 
326 		if (s->sk_hash == num && s->sk_family == PF_INET6) {
327 			struct ipv6_pinfo *np = inet6_sk(s);
328 			if (inet->dport) {
329 				if (inet->dport != rmt_port)
330 					continue;
331 			}
332 			if (!ipv6_addr_any(&np->daddr) &&
333 			    !ipv6_addr_equal(&np->daddr, rmt_addr))
334 				continue;
335 
336 			if (s->sk_bound_dev_if && s->sk_bound_dev_if != dif)
337 				continue;
338 
339 			if (!ipv6_addr_any(&np->rcv_saddr)) {
340 				if (!ipv6_addr_equal(&np->rcv_saddr, loc_addr))
341 					continue;
342 			}
343 			if (!inet6_mc_check(s, loc_addr, rmt_addr))
344 				continue;
345 			return s;
346 		}
347 	}
348 	return NULL;
349 }
350 
351 /*
352  * Note: called only from the BH handler context,
353  * so we don't need to lock the hashes.
354  */
355 static int __udp6_lib_mcast_deliver(struct sk_buff *skb, struct in6_addr *saddr,
356 			   struct in6_addr *daddr, struct hlist_head udptable[])
357 {
358 	struct sock *sk, *sk2;
359 	const struct udphdr *uh = udp_hdr(skb);
360 	int dif;
361 
362 	read_lock(&udp_hash_lock);
363 	sk = sk_head(&udptable[ntohs(uh->dest) & (UDP_HTABLE_SIZE - 1)]);
364 	dif = inet6_iif(skb);
365 	sk = udp_v6_mcast_next(sk, uh->dest, daddr, uh->source, saddr, dif);
366 	if (!sk) {
367 		kfree_skb(skb);
368 		goto out;
369 	}
370 
371 	sk2 = sk;
372 	while ((sk2 = udp_v6_mcast_next(sk_next(sk2), uh->dest, daddr,
373 					uh->source, saddr, dif))) {
374 		struct sk_buff *buff = skb_clone(skb, GFP_ATOMIC);
375 		if (buff) {
376 			bh_lock_sock_nested(sk2);
377 			if (!sock_owned_by_user(sk2))
378 				udpv6_queue_rcv_skb(sk2, buff);
379 			else
380 				sk_add_backlog(sk2, buff);
381 			bh_unlock_sock(sk2);
382 		}
383 	}
384 	bh_lock_sock_nested(sk);
385 	if (!sock_owned_by_user(sk))
386 		udpv6_queue_rcv_skb(sk, skb);
387 	else
388 		sk_add_backlog(sk, skb);
389 	bh_unlock_sock(sk);
390 out:
391 	read_unlock(&udp_hash_lock);
392 	return 0;
393 }
394 
395 static inline int udp6_csum_init(struct sk_buff *skb, struct udphdr *uh,
396 				 int proto)
397 {
398 	int err;
399 
400 	UDP_SKB_CB(skb)->partial_cov = 0;
401 	UDP_SKB_CB(skb)->cscov = skb->len;
402 
403 	if (proto == IPPROTO_UDPLITE) {
404 		err = udplite_checksum_init(skb, uh);
405 		if (err)
406 			return err;
407 	}
408 
409 	if (uh->check == 0) {
410 		/* RFC 2460 section 8.1 says that we SHOULD log
411 		   this error. Well, it is reasonable.
412 		 */
413 		LIMIT_NETDEBUG(KERN_INFO "IPv6: udp checksum is 0\n");
414 		return 1;
415 	}
416 	if (skb->ip_summed == CHECKSUM_COMPLETE &&
417 	    !csum_ipv6_magic(&ipv6_hdr(skb)->saddr, &ipv6_hdr(skb)->daddr,
418 			     skb->len, proto, skb->csum))
419 		skb->ip_summed = CHECKSUM_UNNECESSARY;
420 
421 	if (!skb_csum_unnecessary(skb))
422 		skb->csum = ~csum_unfold(csum_ipv6_magic(&ipv6_hdr(skb)->saddr,
423 							 &ipv6_hdr(skb)->daddr,
424 							 skb->len, proto, 0));
425 
426 	return 0;
427 }
428 
429 int __udp6_lib_rcv(struct sk_buff *skb, struct hlist_head udptable[],
430 		   int proto)
431 {
432 	struct sock *sk;
433 	struct udphdr *uh;
434 	struct net_device *dev = skb->dev;
435 	struct in6_addr *saddr, *daddr;
436 	u32 ulen = 0;
437 
438 	if (!pskb_may_pull(skb, sizeof(struct udphdr)))
439 		goto short_packet;
440 
441 	saddr = &ipv6_hdr(skb)->saddr;
442 	daddr = &ipv6_hdr(skb)->daddr;
443 	uh = udp_hdr(skb);
444 
445 	ulen = ntohs(uh->len);
446 	if (ulen > skb->len)
447 		goto short_packet;
448 
449 	if (proto == IPPROTO_UDP) {
450 		/* UDP validates ulen. */
451 
452 		/* Check for jumbo payload */
453 		if (ulen == 0)
454 			ulen = skb->len;
455 
456 		if (ulen < sizeof(*uh))
457 			goto short_packet;
458 
459 		if (ulen < skb->len) {
460 			if (pskb_trim_rcsum(skb, ulen))
461 				goto short_packet;
462 			saddr = &ipv6_hdr(skb)->saddr;
463 			daddr = &ipv6_hdr(skb)->daddr;
464 			uh = udp_hdr(skb);
465 		}
466 	}
467 
468 	if (udp6_csum_init(skb, uh, proto))
469 		goto discard;
470 
471 	/*
472 	 *	Multicast receive code
473 	 */
474 	if (ipv6_addr_is_multicast(daddr))
475 		return __udp6_lib_mcast_deliver(skb, saddr, daddr, udptable);
476 
477 	/* Unicast */
478 
479 	/*
480 	 * check socket cache ... must talk to Alan about his plans
481 	 * for sock caches... i'll skip this for now.
482 	 */
483 	sk = __udp6_lib_lookup(skb->dev->nd_net, saddr, uh->source,
484 			       daddr, uh->dest, inet6_iif(skb), udptable);
485 
486 	if (sk == NULL) {
487 		if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
488 			goto discard;
489 
490 		if (udp_lib_checksum_complete(skb))
491 			goto discard;
492 		UDP6_INC_STATS_BH(UDP_MIB_NOPORTS, proto == IPPROTO_UDPLITE);
493 
494 		icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0, dev);
495 
496 		kfree_skb(skb);
497 		return 0;
498 	}
499 
500 	/* deliver */
501 
502 	bh_lock_sock_nested(sk);
503 	if (!sock_owned_by_user(sk))
504 		udpv6_queue_rcv_skb(sk, skb);
505 	else
506 		sk_add_backlog(sk, skb);
507 	bh_unlock_sock(sk);
508 	sock_put(sk);
509 	return 0;
510 
511 short_packet:
512 	LIMIT_NETDEBUG(KERN_DEBUG "UDP%sv6: short packet: %d/%u\n",
513 		       proto == IPPROTO_UDPLITE ? "-Lite" : "",
514 		       ulen, skb->len);
515 
516 discard:
517 	UDP6_INC_STATS_BH(UDP_MIB_INERRORS, proto == IPPROTO_UDPLITE);
518 	kfree_skb(skb);
519 	return 0;
520 }
521 
522 static __inline__ int udpv6_rcv(struct sk_buff *skb)
523 {
524 	return __udp6_lib_rcv(skb, udp_hash, IPPROTO_UDP);
525 }
526 
527 /*
528  * Throw away all pending data and cancel the corking. Socket is locked.
529  */
530 static void udp_v6_flush_pending_frames(struct sock *sk)
531 {
532 	struct udp_sock *up = udp_sk(sk);
533 
534 	if (up->pending) {
535 		up->len = 0;
536 		up->pending = 0;
537 		ip6_flush_pending_frames(sk);
538 	}
539 }
540 
541 /*
542  *	Sending
543  */
544 
545 static int udp_v6_push_pending_frames(struct sock *sk)
546 {
547 	struct sk_buff *skb;
548 	struct udphdr *uh;
549 	struct udp_sock  *up = udp_sk(sk);
550 	struct inet_sock *inet = inet_sk(sk);
551 	struct flowi *fl = &inet->cork.fl;
552 	int err = 0;
553 	int is_udplite = IS_UDPLITE(sk);
554 	__wsum csum = 0;
555 
556 	/* Grab the skbuff where UDP header space exists. */
557 	if ((skb = skb_peek(&sk->sk_write_queue)) == NULL)
558 		goto out;
559 
560 	/*
561 	 * Create a UDP header
562 	 */
563 	uh = udp_hdr(skb);
564 	uh->source = fl->fl_ip_sport;
565 	uh->dest = fl->fl_ip_dport;
566 	uh->len = htons(up->len);
567 	uh->check = 0;
568 
569 	if (is_udplite)
570 		csum = udplite_csum_outgoing(sk, skb);
571 	 else
572 		csum = udp_csum_outgoing(sk, skb);
573 
574 	/* add protocol-dependent pseudo-header */
575 	uh->check = csum_ipv6_magic(&fl->fl6_src, &fl->fl6_dst,
576 				    up->len, fl->proto, csum   );
577 	if (uh->check == 0)
578 		uh->check = CSUM_MANGLED_0;
579 
580 	err = ip6_push_pending_frames(sk);
581 out:
582 	up->len = 0;
583 	up->pending = 0;
584 	if (!err)
585 		UDP6_INC_STATS_USER(UDP_MIB_OUTDATAGRAMS, is_udplite);
586 	return err;
587 }
588 
589 int udpv6_sendmsg(struct kiocb *iocb, struct sock *sk,
590 		  struct msghdr *msg, size_t len)
591 {
592 	struct ipv6_txoptions opt_space;
593 	struct udp_sock *up = udp_sk(sk);
594 	struct inet_sock *inet = inet_sk(sk);
595 	struct ipv6_pinfo *np = inet6_sk(sk);
596 	struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *) msg->msg_name;
597 	struct in6_addr *daddr, *final_p = NULL, final;
598 	struct ipv6_txoptions *opt = NULL;
599 	struct ip6_flowlabel *flowlabel = NULL;
600 	struct flowi fl;
601 	struct dst_entry *dst;
602 	int addr_len = msg->msg_namelen;
603 	int ulen = len;
604 	int hlimit = -1;
605 	int tclass = -1;
606 	int corkreq = up->corkflag || msg->msg_flags&MSG_MORE;
607 	int err;
608 	int connected = 0;
609 	int is_udplite = IS_UDPLITE(sk);
610 	int (*getfrag)(void *, char *, int, int, int, struct sk_buff *);
611 
612 	/* destination address check */
613 	if (sin6) {
614 		if (addr_len < offsetof(struct sockaddr, sa_data))
615 			return -EINVAL;
616 
617 		switch (sin6->sin6_family) {
618 		case AF_INET6:
619 			if (addr_len < SIN6_LEN_RFC2133)
620 				return -EINVAL;
621 			daddr = &sin6->sin6_addr;
622 			break;
623 		case AF_INET:
624 			goto do_udp_sendmsg;
625 		case AF_UNSPEC:
626 			msg->msg_name = sin6 = NULL;
627 			msg->msg_namelen = addr_len = 0;
628 			daddr = NULL;
629 			break;
630 		default:
631 			return -EINVAL;
632 		}
633 	} else if (!up->pending) {
634 		if (sk->sk_state != TCP_ESTABLISHED)
635 			return -EDESTADDRREQ;
636 		daddr = &np->daddr;
637 	} else
638 		daddr = NULL;
639 
640 	if (daddr) {
641 		if (ipv6_addr_v4mapped(daddr)) {
642 			struct sockaddr_in sin;
643 			sin.sin_family = AF_INET;
644 			sin.sin_port = sin6 ? sin6->sin6_port : inet->dport;
645 			sin.sin_addr.s_addr = daddr->s6_addr32[3];
646 			msg->msg_name = &sin;
647 			msg->msg_namelen = sizeof(sin);
648 do_udp_sendmsg:
649 			if (__ipv6_only_sock(sk))
650 				return -ENETUNREACH;
651 			return udp_sendmsg(iocb, sk, msg, len);
652 		}
653 	}
654 
655 	if (up->pending == AF_INET)
656 		return udp_sendmsg(iocb, sk, msg, len);
657 
658 	/* Rough check on arithmetic overflow,
659 	   better check is made in ip6_append_data().
660 	   */
661 	if (len > INT_MAX - sizeof(struct udphdr))
662 		return -EMSGSIZE;
663 
664 	if (up->pending) {
665 		/*
666 		 * There are pending frames.
667 		 * The socket lock must be held while it's corked.
668 		 */
669 		lock_sock(sk);
670 		if (likely(up->pending)) {
671 			if (unlikely(up->pending != AF_INET6)) {
672 				release_sock(sk);
673 				return -EAFNOSUPPORT;
674 			}
675 			dst = NULL;
676 			goto do_append_data;
677 		}
678 		release_sock(sk);
679 	}
680 	ulen += sizeof(struct udphdr);
681 
682 	memset(&fl, 0, sizeof(fl));
683 
684 	if (sin6) {
685 		if (sin6->sin6_port == 0)
686 			return -EINVAL;
687 
688 		fl.fl_ip_dport = sin6->sin6_port;
689 		daddr = &sin6->sin6_addr;
690 
691 		if (np->sndflow) {
692 			fl.fl6_flowlabel = sin6->sin6_flowinfo&IPV6_FLOWINFO_MASK;
693 			if (fl.fl6_flowlabel&IPV6_FLOWLABEL_MASK) {
694 				flowlabel = fl6_sock_lookup(sk, fl.fl6_flowlabel);
695 				if (flowlabel == NULL)
696 					return -EINVAL;
697 				daddr = &flowlabel->dst;
698 			}
699 		}
700 
701 		/*
702 		 * Otherwise it will be difficult to maintain
703 		 * sk->sk_dst_cache.
704 		 */
705 		if (sk->sk_state == TCP_ESTABLISHED &&
706 		    ipv6_addr_equal(daddr, &np->daddr))
707 			daddr = &np->daddr;
708 
709 		if (addr_len >= sizeof(struct sockaddr_in6) &&
710 		    sin6->sin6_scope_id &&
711 		    ipv6_addr_type(daddr)&IPV6_ADDR_LINKLOCAL)
712 			fl.oif = sin6->sin6_scope_id;
713 	} else {
714 		if (sk->sk_state != TCP_ESTABLISHED)
715 			return -EDESTADDRREQ;
716 
717 		fl.fl_ip_dport = inet->dport;
718 		daddr = &np->daddr;
719 		fl.fl6_flowlabel = np->flow_label;
720 		connected = 1;
721 	}
722 
723 	if (!fl.oif)
724 		fl.oif = sk->sk_bound_dev_if;
725 
726 	if (msg->msg_controllen) {
727 		opt = &opt_space;
728 		memset(opt, 0, sizeof(struct ipv6_txoptions));
729 		opt->tot_len = sizeof(*opt);
730 
731 		err = datagram_send_ctl(msg, &fl, opt, &hlimit, &tclass);
732 		if (err < 0) {
733 			fl6_sock_release(flowlabel);
734 			return err;
735 		}
736 		if ((fl.fl6_flowlabel&IPV6_FLOWLABEL_MASK) && !flowlabel) {
737 			flowlabel = fl6_sock_lookup(sk, fl.fl6_flowlabel);
738 			if (flowlabel == NULL)
739 				return -EINVAL;
740 		}
741 		if (!(opt->opt_nflen|opt->opt_flen))
742 			opt = NULL;
743 		connected = 0;
744 	}
745 	if (opt == NULL)
746 		opt = np->opt;
747 	if (flowlabel)
748 		opt = fl6_merge_options(&opt_space, flowlabel, opt);
749 	opt = ipv6_fixup_options(&opt_space, opt);
750 
751 	fl.proto = sk->sk_protocol;
752 	ipv6_addr_copy(&fl.fl6_dst, daddr);
753 	if (ipv6_addr_any(&fl.fl6_src) && !ipv6_addr_any(&np->saddr))
754 		ipv6_addr_copy(&fl.fl6_src, &np->saddr);
755 	fl.fl_ip_sport = inet->sport;
756 
757 	/* merge ip6_build_xmit from ip6_output */
758 	if (opt && opt->srcrt) {
759 		struct rt0_hdr *rt0 = (struct rt0_hdr *) opt->srcrt;
760 		ipv6_addr_copy(&final, &fl.fl6_dst);
761 		ipv6_addr_copy(&fl.fl6_dst, rt0->addr);
762 		final_p = &final;
763 		connected = 0;
764 	}
765 
766 	if (!fl.oif && ipv6_addr_is_multicast(&fl.fl6_dst)) {
767 		fl.oif = np->mcast_oif;
768 		connected = 0;
769 	}
770 
771 	security_sk_classify_flow(sk, &fl);
772 
773 	err = ip6_sk_dst_lookup(sk, &dst, &fl);
774 	if (err)
775 		goto out;
776 	if (final_p)
777 		ipv6_addr_copy(&fl.fl6_dst, final_p);
778 
779 	if ((err = __xfrm_lookup(&dst, &fl, sk, XFRM_LOOKUP_WAIT)) < 0) {
780 		if (err == -EREMOTE)
781 			err = ip6_dst_blackhole(sk, &dst, &fl);
782 		if (err < 0)
783 			goto out;
784 	}
785 
786 	if (hlimit < 0) {
787 		if (ipv6_addr_is_multicast(&fl.fl6_dst))
788 			hlimit = np->mcast_hops;
789 		else
790 			hlimit = np->hop_limit;
791 		if (hlimit < 0)
792 			hlimit = dst_metric(dst, RTAX_HOPLIMIT);
793 		if (hlimit < 0)
794 			hlimit = ipv6_get_hoplimit(dst->dev);
795 	}
796 
797 	if (tclass < 0) {
798 		tclass = np->tclass;
799 		if (tclass < 0)
800 			tclass = 0;
801 	}
802 
803 	if (msg->msg_flags&MSG_CONFIRM)
804 		goto do_confirm;
805 back_from_confirm:
806 
807 	lock_sock(sk);
808 	if (unlikely(up->pending)) {
809 		/* The socket is already corked while preparing it. */
810 		/* ... which is an evident application bug. --ANK */
811 		release_sock(sk);
812 
813 		LIMIT_NETDEBUG(KERN_DEBUG "udp cork app bug 2\n");
814 		err = -EINVAL;
815 		goto out;
816 	}
817 
818 	up->pending = AF_INET6;
819 
820 do_append_data:
821 	up->len += ulen;
822 	getfrag  =  is_udplite ?  udplite_getfrag : ip_generic_getfrag;
823 	err = ip6_append_data(sk, getfrag, msg->msg_iov, ulen,
824 		sizeof(struct udphdr), hlimit, tclass, opt, &fl,
825 		(struct rt6_info*)dst,
826 		corkreq ? msg->msg_flags|MSG_MORE : msg->msg_flags);
827 	if (err)
828 		udp_v6_flush_pending_frames(sk);
829 	else if (!corkreq)
830 		err = udp_v6_push_pending_frames(sk);
831 	else if (unlikely(skb_queue_empty(&sk->sk_write_queue)))
832 		up->pending = 0;
833 
834 	if (dst) {
835 		if (connected) {
836 			ip6_dst_store(sk, dst,
837 				      ipv6_addr_equal(&fl.fl6_dst, &np->daddr) ?
838 				      &np->daddr : NULL,
839 #ifdef CONFIG_IPV6_SUBTREES
840 				      ipv6_addr_equal(&fl.fl6_src, &np->saddr) ?
841 				      &np->saddr :
842 #endif
843 				      NULL);
844 		} else {
845 			dst_release(dst);
846 		}
847 	}
848 
849 	if (err > 0)
850 		err = np->recverr ? net_xmit_errno(err) : 0;
851 	release_sock(sk);
852 out:
853 	fl6_sock_release(flowlabel);
854 	if (!err)
855 		return len;
856 	/*
857 	 * ENOBUFS = no kernel mem, SOCK_NOSPACE = no sndbuf space.  Reporting
858 	 * ENOBUFS might not be good (it's not tunable per se), but otherwise
859 	 * we don't have a good statistic (IpOutDiscards but it can be too many
860 	 * things).  We could add another new stat but at least for now that
861 	 * seems like overkill.
862 	 */
863 	if (err == -ENOBUFS || test_bit(SOCK_NOSPACE, &sk->sk_socket->flags)) {
864 		UDP6_INC_STATS_USER(UDP_MIB_SNDBUFERRORS, is_udplite);
865 	}
866 	return err;
867 
868 do_confirm:
869 	dst_confirm(dst);
870 	if (!(msg->msg_flags&MSG_PROBE) || len)
871 		goto back_from_confirm;
872 	err = 0;
873 	goto out;
874 }
875 
876 int udpv6_destroy_sock(struct sock *sk)
877 {
878 	lock_sock(sk);
879 	udp_v6_flush_pending_frames(sk);
880 	release_sock(sk);
881 
882 	inet6_destroy_sock(sk);
883 
884 	return 0;
885 }
886 
887 /*
888  *	Socket option code for UDP
889  */
890 int udpv6_setsockopt(struct sock *sk, int level, int optname,
891 		     char __user *optval, int optlen)
892 {
893 	if (level == SOL_UDP  ||  level == SOL_UDPLITE)
894 		return udp_lib_setsockopt(sk, level, optname, optval, optlen,
895 					  udp_v6_push_pending_frames);
896 	return ipv6_setsockopt(sk, level, optname, optval, optlen);
897 }
898 
899 #ifdef CONFIG_COMPAT
900 int compat_udpv6_setsockopt(struct sock *sk, int level, int optname,
901 			    char __user *optval, int optlen)
902 {
903 	if (level == SOL_UDP  ||  level == SOL_UDPLITE)
904 		return udp_lib_setsockopt(sk, level, optname, optval, optlen,
905 					  udp_v6_push_pending_frames);
906 	return compat_ipv6_setsockopt(sk, level, optname, optval, optlen);
907 }
908 #endif
909 
910 int udpv6_getsockopt(struct sock *sk, int level, int optname,
911 		     char __user *optval, int __user *optlen)
912 {
913 	if (level == SOL_UDP  ||  level == SOL_UDPLITE)
914 		return udp_lib_getsockopt(sk, level, optname, optval, optlen);
915 	return ipv6_getsockopt(sk, level, optname, optval, optlen);
916 }
917 
918 #ifdef CONFIG_COMPAT
919 int compat_udpv6_getsockopt(struct sock *sk, int level, int optname,
920 			    char __user *optval, int __user *optlen)
921 {
922 	if (level == SOL_UDP  ||  level == SOL_UDPLITE)
923 		return udp_lib_getsockopt(sk, level, optname, optval, optlen);
924 	return compat_ipv6_getsockopt(sk, level, optname, optval, optlen);
925 }
926 #endif
927 
928 static struct inet6_protocol udpv6_protocol = {
929 	.handler	=	udpv6_rcv,
930 	.err_handler	=	udpv6_err,
931 	.flags		=	INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
932 };
933 
934 /* ------------------------------------------------------------------------ */
935 #ifdef CONFIG_PROC_FS
936 
937 static void udp6_sock_seq_show(struct seq_file *seq, struct sock *sp, int bucket)
938 {
939 	struct inet_sock *inet = inet_sk(sp);
940 	struct ipv6_pinfo *np = inet6_sk(sp);
941 	struct in6_addr *dest, *src;
942 	__u16 destp, srcp;
943 
944 	dest  = &np->daddr;
945 	src   = &np->rcv_saddr;
946 	destp = ntohs(inet->dport);
947 	srcp  = ntohs(inet->sport);
948 	seq_printf(seq,
949 		   "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
950 		   "%02X %08X:%08X %02X:%08lX %08X %5d %8d %lu %d %p\n",
951 		   bucket,
952 		   src->s6_addr32[0], src->s6_addr32[1],
953 		   src->s6_addr32[2], src->s6_addr32[3], srcp,
954 		   dest->s6_addr32[0], dest->s6_addr32[1],
955 		   dest->s6_addr32[2], dest->s6_addr32[3], destp,
956 		   sp->sk_state,
957 		   atomic_read(&sp->sk_wmem_alloc),
958 		   atomic_read(&sp->sk_rmem_alloc),
959 		   0, 0L, 0,
960 		   sock_i_uid(sp), 0,
961 		   sock_i_ino(sp),
962 		   atomic_read(&sp->sk_refcnt), sp);
963 }
964 
965 int udp6_seq_show(struct seq_file *seq, void *v)
966 {
967 	if (v == SEQ_START_TOKEN)
968 		seq_printf(seq,
969 			   "  sl  "
970 			   "local_address                         "
971 			   "remote_address                        "
972 			   "st tx_queue rx_queue tr tm->when retrnsmt"
973 			   "   uid  timeout inode\n");
974 	else
975 		udp6_sock_seq_show(seq, v, ((struct udp_iter_state *)seq->private)->bucket);
976 	return 0;
977 }
978 
979 static struct file_operations udp6_seq_fops;
980 static struct udp_seq_afinfo udp6_seq_afinfo = {
981 	.owner		= THIS_MODULE,
982 	.name		= "udp6",
983 	.family		= AF_INET6,
984 	.hashtable	= udp_hash,
985 	.seq_show	= udp6_seq_show,
986 	.seq_fops	= &udp6_seq_fops,
987 };
988 
989 int __init udp6_proc_init(void)
990 {
991 	return udp_proc_register(&udp6_seq_afinfo);
992 }
993 
994 void udp6_proc_exit(void) {
995 	udp_proc_unregister(&udp6_seq_afinfo);
996 }
997 #endif /* CONFIG_PROC_FS */
998 
999 /* ------------------------------------------------------------------------ */
1000 
1001 DEFINE_PROTO_INUSE(udpv6)
1002 
1003 struct proto udpv6_prot = {
1004 	.name		   = "UDPv6",
1005 	.owner		   = THIS_MODULE,
1006 	.close		   = udp_lib_close,
1007 	.connect	   = ip6_datagram_connect,
1008 	.disconnect	   = udp_disconnect,
1009 	.ioctl		   = udp_ioctl,
1010 	.destroy	   = udpv6_destroy_sock,
1011 	.setsockopt	   = udpv6_setsockopt,
1012 	.getsockopt	   = udpv6_getsockopt,
1013 	.sendmsg	   = udpv6_sendmsg,
1014 	.recvmsg	   = udpv6_recvmsg,
1015 	.backlog_rcv	   = udpv6_queue_rcv_skb,
1016 	.hash		   = udp_lib_hash,
1017 	.unhash		   = udp_lib_unhash,
1018 	.get_port	   = udp_v6_get_port,
1019 	.memory_allocated  = &udp_memory_allocated,
1020 	.sysctl_mem	   = sysctl_udp_mem,
1021 	.sysctl_wmem	   = &sysctl_udp_wmem_min,
1022 	.sysctl_rmem	   = &sysctl_udp_rmem_min,
1023 	.obj_size	   = sizeof(struct udp6_sock),
1024 #ifdef CONFIG_COMPAT
1025 	.compat_setsockopt = compat_udpv6_setsockopt,
1026 	.compat_getsockopt = compat_udpv6_getsockopt,
1027 #endif
1028 	REF_PROTO_INUSE(udpv6)
1029 };
1030 
1031 static struct inet_protosw udpv6_protosw = {
1032 	.type =      SOCK_DGRAM,
1033 	.protocol =  IPPROTO_UDP,
1034 	.prot =      &udpv6_prot,
1035 	.ops =       &inet6_dgram_ops,
1036 	.capability =-1,
1037 	.no_check =  UDP_CSUM_DEFAULT,
1038 	.flags =     INET_PROTOSW_PERMANENT,
1039 };
1040 
1041 
1042 int __init udpv6_init(void)
1043 {
1044 	int ret;
1045 
1046 	ret = inet6_add_protocol(&udpv6_protocol, IPPROTO_UDP);
1047 	if (ret)
1048 		goto out;
1049 
1050 	ret = inet6_register_protosw(&udpv6_protosw);
1051 	if (ret)
1052 		goto out_udpv6_protocol;
1053 out:
1054 	return ret;
1055 
1056 out_udpv6_protocol:
1057 	inet6_del_protocol(&udpv6_protocol, IPPROTO_UDP);
1058 	goto out;
1059 }
1060 
1061 void udpv6_exit(void)
1062 {
1063 	inet6_unregister_protosw(&udpv6_protosw);
1064 	inet6_del_protocol(&udpv6_protocol, IPPROTO_UDP);
1065 }
1066