xref: /openbmc/linux/net/ipv6/udp.c (revision f42b3800)
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 int udp_v6_get_port(struct sock *sk, unsigned short snum)
55 {
56 	return udp_lib_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 (net_eq(sock_net(sk), 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(dev_net(skb->dev), 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 (sock_net(s) != sock_net(sk))
327 			continue;
328 
329 		if (s->sk_hash == num && s->sk_family == PF_INET6) {
330 			struct ipv6_pinfo *np = inet6_sk(s);
331 			if (inet->dport) {
332 				if (inet->dport != rmt_port)
333 					continue;
334 			}
335 			if (!ipv6_addr_any(&np->daddr) &&
336 			    !ipv6_addr_equal(&np->daddr, rmt_addr))
337 				continue;
338 
339 			if (s->sk_bound_dev_if && s->sk_bound_dev_if != dif)
340 				continue;
341 
342 			if (!ipv6_addr_any(&np->rcv_saddr)) {
343 				if (!ipv6_addr_equal(&np->rcv_saddr, loc_addr))
344 					continue;
345 			}
346 			if (!inet6_mc_check(s, loc_addr, rmt_addr))
347 				continue;
348 			return s;
349 		}
350 	}
351 	return NULL;
352 }
353 
354 /*
355  * Note: called only from the BH handler context,
356  * so we don't need to lock the hashes.
357  */
358 static int __udp6_lib_mcast_deliver(struct sk_buff *skb, struct in6_addr *saddr,
359 			   struct in6_addr *daddr, struct hlist_head udptable[])
360 {
361 	struct sock *sk, *sk2;
362 	const struct udphdr *uh = udp_hdr(skb);
363 	int dif;
364 
365 	read_lock(&udp_hash_lock);
366 	sk = sk_head(&udptable[ntohs(uh->dest) & (UDP_HTABLE_SIZE - 1)]);
367 	dif = inet6_iif(skb);
368 	sk = udp_v6_mcast_next(sk, uh->dest, daddr, uh->source, saddr, dif);
369 	if (!sk) {
370 		kfree_skb(skb);
371 		goto out;
372 	}
373 
374 	sk2 = sk;
375 	while ((sk2 = udp_v6_mcast_next(sk_next(sk2), uh->dest, daddr,
376 					uh->source, saddr, dif))) {
377 		struct sk_buff *buff = skb_clone(skb, GFP_ATOMIC);
378 		if (buff) {
379 			bh_lock_sock_nested(sk2);
380 			if (!sock_owned_by_user(sk2))
381 				udpv6_queue_rcv_skb(sk2, buff);
382 			else
383 				sk_add_backlog(sk2, buff);
384 			bh_unlock_sock(sk2);
385 		}
386 	}
387 	bh_lock_sock_nested(sk);
388 	if (!sock_owned_by_user(sk))
389 		udpv6_queue_rcv_skb(sk, skb);
390 	else
391 		sk_add_backlog(sk, skb);
392 	bh_unlock_sock(sk);
393 out:
394 	read_unlock(&udp_hash_lock);
395 	return 0;
396 }
397 
398 static inline int udp6_csum_init(struct sk_buff *skb, struct udphdr *uh,
399 				 int proto)
400 {
401 	int err;
402 
403 	UDP_SKB_CB(skb)->partial_cov = 0;
404 	UDP_SKB_CB(skb)->cscov = skb->len;
405 
406 	if (proto == IPPROTO_UDPLITE) {
407 		err = udplite_checksum_init(skb, uh);
408 		if (err)
409 			return err;
410 	}
411 
412 	if (uh->check == 0) {
413 		/* RFC 2460 section 8.1 says that we SHOULD log
414 		   this error. Well, it is reasonable.
415 		 */
416 		LIMIT_NETDEBUG(KERN_INFO "IPv6: udp checksum is 0\n");
417 		return 1;
418 	}
419 	if (skb->ip_summed == CHECKSUM_COMPLETE &&
420 	    !csum_ipv6_magic(&ipv6_hdr(skb)->saddr, &ipv6_hdr(skb)->daddr,
421 			     skb->len, proto, skb->csum))
422 		skb->ip_summed = CHECKSUM_UNNECESSARY;
423 
424 	if (!skb_csum_unnecessary(skb))
425 		skb->csum = ~csum_unfold(csum_ipv6_magic(&ipv6_hdr(skb)->saddr,
426 							 &ipv6_hdr(skb)->daddr,
427 							 skb->len, proto, 0));
428 
429 	return 0;
430 }
431 
432 int __udp6_lib_rcv(struct sk_buff *skb, struct hlist_head udptable[],
433 		   int proto)
434 {
435 	struct sock *sk;
436 	struct udphdr *uh;
437 	struct net_device *dev = skb->dev;
438 	struct in6_addr *saddr, *daddr;
439 	u32 ulen = 0;
440 
441 	if (!pskb_may_pull(skb, sizeof(struct udphdr)))
442 		goto short_packet;
443 
444 	saddr = &ipv6_hdr(skb)->saddr;
445 	daddr = &ipv6_hdr(skb)->daddr;
446 	uh = udp_hdr(skb);
447 
448 	ulen = ntohs(uh->len);
449 	if (ulen > skb->len)
450 		goto short_packet;
451 
452 	if (proto == IPPROTO_UDP) {
453 		/* UDP validates ulen. */
454 
455 		/* Check for jumbo payload */
456 		if (ulen == 0)
457 			ulen = skb->len;
458 
459 		if (ulen < sizeof(*uh))
460 			goto short_packet;
461 
462 		if (ulen < skb->len) {
463 			if (pskb_trim_rcsum(skb, ulen))
464 				goto short_packet;
465 			saddr = &ipv6_hdr(skb)->saddr;
466 			daddr = &ipv6_hdr(skb)->daddr;
467 			uh = udp_hdr(skb);
468 		}
469 	}
470 
471 	if (udp6_csum_init(skb, uh, proto))
472 		goto discard;
473 
474 	/*
475 	 *	Multicast receive code
476 	 */
477 	if (ipv6_addr_is_multicast(daddr))
478 		return __udp6_lib_mcast_deliver(skb, saddr, daddr, udptable);
479 
480 	/* Unicast */
481 
482 	/*
483 	 * check socket cache ... must talk to Alan about his plans
484 	 * for sock caches... i'll skip this for now.
485 	 */
486 	sk = __udp6_lib_lookup(dev_net(skb->dev), saddr, uh->source,
487 			       daddr, uh->dest, inet6_iif(skb), udptable);
488 
489 	if (sk == NULL) {
490 		if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
491 			goto discard;
492 
493 		if (udp_lib_checksum_complete(skb))
494 			goto discard;
495 		UDP6_INC_STATS_BH(UDP_MIB_NOPORTS, proto == IPPROTO_UDPLITE);
496 
497 		icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0, dev);
498 
499 		kfree_skb(skb);
500 		return 0;
501 	}
502 
503 	/* deliver */
504 
505 	bh_lock_sock_nested(sk);
506 	if (!sock_owned_by_user(sk))
507 		udpv6_queue_rcv_skb(sk, skb);
508 	else
509 		sk_add_backlog(sk, skb);
510 	bh_unlock_sock(sk);
511 	sock_put(sk);
512 	return 0;
513 
514 short_packet:
515 	LIMIT_NETDEBUG(KERN_DEBUG "UDP%sv6: short packet: %d/%u\n",
516 		       proto == IPPROTO_UDPLITE ? "-Lite" : "",
517 		       ulen, skb->len);
518 
519 discard:
520 	UDP6_INC_STATS_BH(UDP_MIB_INERRORS, proto == IPPROTO_UDPLITE);
521 	kfree_skb(skb);
522 	return 0;
523 }
524 
525 static __inline__ int udpv6_rcv(struct sk_buff *skb)
526 {
527 	return __udp6_lib_rcv(skb, udp_hash, IPPROTO_UDP);
528 }
529 
530 /*
531  * Throw away all pending data and cancel the corking. Socket is locked.
532  */
533 static void udp_v6_flush_pending_frames(struct sock *sk)
534 {
535 	struct udp_sock *up = udp_sk(sk);
536 
537 	if (up->pending) {
538 		up->len = 0;
539 		up->pending = 0;
540 		ip6_flush_pending_frames(sk);
541 	}
542 }
543 
544 /*
545  *	Sending
546  */
547 
548 static int udp_v6_push_pending_frames(struct sock *sk)
549 {
550 	struct sk_buff *skb;
551 	struct udphdr *uh;
552 	struct udp_sock  *up = udp_sk(sk);
553 	struct inet_sock *inet = inet_sk(sk);
554 	struct flowi *fl = &inet->cork.fl;
555 	int err = 0;
556 	int is_udplite = IS_UDPLITE(sk);
557 	__wsum csum = 0;
558 
559 	/* Grab the skbuff where UDP header space exists. */
560 	if ((skb = skb_peek(&sk->sk_write_queue)) == NULL)
561 		goto out;
562 
563 	/*
564 	 * Create a UDP header
565 	 */
566 	uh = udp_hdr(skb);
567 	uh->source = fl->fl_ip_sport;
568 	uh->dest = fl->fl_ip_dport;
569 	uh->len = htons(up->len);
570 	uh->check = 0;
571 
572 	if (is_udplite)
573 		csum = udplite_csum_outgoing(sk, skb);
574 	 else
575 		csum = udp_csum_outgoing(sk, skb);
576 
577 	/* add protocol-dependent pseudo-header */
578 	uh->check = csum_ipv6_magic(&fl->fl6_src, &fl->fl6_dst,
579 				    up->len, fl->proto, csum   );
580 	if (uh->check == 0)
581 		uh->check = CSUM_MANGLED_0;
582 
583 	err = ip6_push_pending_frames(sk);
584 out:
585 	up->len = 0;
586 	up->pending = 0;
587 	if (!err)
588 		UDP6_INC_STATS_USER(UDP_MIB_OUTDATAGRAMS, is_udplite);
589 	return err;
590 }
591 
592 int udpv6_sendmsg(struct kiocb *iocb, struct sock *sk,
593 		  struct msghdr *msg, size_t len)
594 {
595 	struct ipv6_txoptions opt_space;
596 	struct udp_sock *up = udp_sk(sk);
597 	struct inet_sock *inet = inet_sk(sk);
598 	struct ipv6_pinfo *np = inet6_sk(sk);
599 	struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *) msg->msg_name;
600 	struct in6_addr *daddr, *final_p = NULL, final;
601 	struct ipv6_txoptions *opt = NULL;
602 	struct ip6_flowlabel *flowlabel = NULL;
603 	struct flowi fl;
604 	struct dst_entry *dst;
605 	int addr_len = msg->msg_namelen;
606 	int ulen = len;
607 	int hlimit = -1;
608 	int tclass = -1;
609 	int corkreq = up->corkflag || msg->msg_flags&MSG_MORE;
610 	int err;
611 	int connected = 0;
612 	int is_udplite = IS_UDPLITE(sk);
613 	int (*getfrag)(void *, char *, int, int, int, struct sk_buff *);
614 
615 	/* destination address check */
616 	if (sin6) {
617 		if (addr_len < offsetof(struct sockaddr, sa_data))
618 			return -EINVAL;
619 
620 		switch (sin6->sin6_family) {
621 		case AF_INET6:
622 			if (addr_len < SIN6_LEN_RFC2133)
623 				return -EINVAL;
624 			daddr = &sin6->sin6_addr;
625 			break;
626 		case AF_INET:
627 			goto do_udp_sendmsg;
628 		case AF_UNSPEC:
629 			msg->msg_name = sin6 = NULL;
630 			msg->msg_namelen = addr_len = 0;
631 			daddr = NULL;
632 			break;
633 		default:
634 			return -EINVAL;
635 		}
636 	} else if (!up->pending) {
637 		if (sk->sk_state != TCP_ESTABLISHED)
638 			return -EDESTADDRREQ;
639 		daddr = &np->daddr;
640 	} else
641 		daddr = NULL;
642 
643 	if (daddr) {
644 		if (ipv6_addr_v4mapped(daddr)) {
645 			struct sockaddr_in sin;
646 			sin.sin_family = AF_INET;
647 			sin.sin_port = sin6 ? sin6->sin6_port : inet->dport;
648 			sin.sin_addr.s_addr = daddr->s6_addr32[3];
649 			msg->msg_name = &sin;
650 			msg->msg_namelen = sizeof(sin);
651 do_udp_sendmsg:
652 			if (__ipv6_only_sock(sk))
653 				return -ENETUNREACH;
654 			return udp_sendmsg(iocb, sk, msg, len);
655 		}
656 	}
657 
658 	if (up->pending == AF_INET)
659 		return udp_sendmsg(iocb, sk, msg, len);
660 
661 	/* Rough check on arithmetic overflow,
662 	   better check is made in ip6_append_data().
663 	   */
664 	if (len > INT_MAX - sizeof(struct udphdr))
665 		return -EMSGSIZE;
666 
667 	if (up->pending) {
668 		/*
669 		 * There are pending frames.
670 		 * The socket lock must be held while it's corked.
671 		 */
672 		lock_sock(sk);
673 		if (likely(up->pending)) {
674 			if (unlikely(up->pending != AF_INET6)) {
675 				release_sock(sk);
676 				return -EAFNOSUPPORT;
677 			}
678 			dst = NULL;
679 			goto do_append_data;
680 		}
681 		release_sock(sk);
682 	}
683 	ulen += sizeof(struct udphdr);
684 
685 	memset(&fl, 0, sizeof(fl));
686 
687 	if (sin6) {
688 		if (sin6->sin6_port == 0)
689 			return -EINVAL;
690 
691 		fl.fl_ip_dport = sin6->sin6_port;
692 		daddr = &sin6->sin6_addr;
693 
694 		if (np->sndflow) {
695 			fl.fl6_flowlabel = sin6->sin6_flowinfo&IPV6_FLOWINFO_MASK;
696 			if (fl.fl6_flowlabel&IPV6_FLOWLABEL_MASK) {
697 				flowlabel = fl6_sock_lookup(sk, fl.fl6_flowlabel);
698 				if (flowlabel == NULL)
699 					return -EINVAL;
700 				daddr = &flowlabel->dst;
701 			}
702 		}
703 
704 		/*
705 		 * Otherwise it will be difficult to maintain
706 		 * sk->sk_dst_cache.
707 		 */
708 		if (sk->sk_state == TCP_ESTABLISHED &&
709 		    ipv6_addr_equal(daddr, &np->daddr))
710 			daddr = &np->daddr;
711 
712 		if (addr_len >= sizeof(struct sockaddr_in6) &&
713 		    sin6->sin6_scope_id &&
714 		    ipv6_addr_type(daddr)&IPV6_ADDR_LINKLOCAL)
715 			fl.oif = sin6->sin6_scope_id;
716 	} else {
717 		if (sk->sk_state != TCP_ESTABLISHED)
718 			return -EDESTADDRREQ;
719 
720 		fl.fl_ip_dport = inet->dport;
721 		daddr = &np->daddr;
722 		fl.fl6_flowlabel = np->flow_label;
723 		connected = 1;
724 	}
725 
726 	if (!fl.oif)
727 		fl.oif = sk->sk_bound_dev_if;
728 
729 	if (msg->msg_controllen) {
730 		opt = &opt_space;
731 		memset(opt, 0, sizeof(struct ipv6_txoptions));
732 		opt->tot_len = sizeof(*opt);
733 
734 		err = datagram_send_ctl(msg, &fl, opt, &hlimit, &tclass);
735 		if (err < 0) {
736 			fl6_sock_release(flowlabel);
737 			return err;
738 		}
739 		if ((fl.fl6_flowlabel&IPV6_FLOWLABEL_MASK) && !flowlabel) {
740 			flowlabel = fl6_sock_lookup(sk, fl.fl6_flowlabel);
741 			if (flowlabel == NULL)
742 				return -EINVAL;
743 		}
744 		if (!(opt->opt_nflen|opt->opt_flen))
745 			opt = NULL;
746 		connected = 0;
747 	}
748 	if (opt == NULL)
749 		opt = np->opt;
750 	if (flowlabel)
751 		opt = fl6_merge_options(&opt_space, flowlabel, opt);
752 	opt = ipv6_fixup_options(&opt_space, opt);
753 
754 	fl.proto = sk->sk_protocol;
755 	if (!ipv6_addr_any(daddr))
756 		ipv6_addr_copy(&fl.fl6_dst, daddr);
757 	else
758 		fl.fl6_dst.s6_addr[15] = 0x1; /* :: means loopback (BSD'ism) */
759 	if (ipv6_addr_any(&fl.fl6_src) && !ipv6_addr_any(&np->saddr))
760 		ipv6_addr_copy(&fl.fl6_src, &np->saddr);
761 	fl.fl_ip_sport = inet->sport;
762 
763 	/* merge ip6_build_xmit from ip6_output */
764 	if (opt && opt->srcrt) {
765 		struct rt0_hdr *rt0 = (struct rt0_hdr *) opt->srcrt;
766 		ipv6_addr_copy(&final, &fl.fl6_dst);
767 		ipv6_addr_copy(&fl.fl6_dst, rt0->addr);
768 		final_p = &final;
769 		connected = 0;
770 	}
771 
772 	if (!fl.oif && ipv6_addr_is_multicast(&fl.fl6_dst)) {
773 		fl.oif = np->mcast_oif;
774 		connected = 0;
775 	}
776 
777 	security_sk_classify_flow(sk, &fl);
778 
779 	err = ip6_sk_dst_lookup(sk, &dst, &fl);
780 	if (err)
781 		goto out;
782 	if (final_p)
783 		ipv6_addr_copy(&fl.fl6_dst, final_p);
784 
785 	if ((err = __xfrm_lookup(&dst, &fl, sk, XFRM_LOOKUP_WAIT)) < 0) {
786 		if (err == -EREMOTE)
787 			err = ip6_dst_blackhole(sk, &dst, &fl);
788 		if (err < 0)
789 			goto out;
790 	}
791 
792 	if (hlimit < 0) {
793 		if (ipv6_addr_is_multicast(&fl.fl6_dst))
794 			hlimit = np->mcast_hops;
795 		else
796 			hlimit = np->hop_limit;
797 		if (hlimit < 0)
798 			hlimit = ip6_dst_hoplimit(dst);
799 	}
800 
801 	if (tclass < 0) {
802 		tclass = np->tclass;
803 		if (tclass < 0)
804 			tclass = 0;
805 	}
806 
807 	if (msg->msg_flags&MSG_CONFIRM)
808 		goto do_confirm;
809 back_from_confirm:
810 
811 	lock_sock(sk);
812 	if (unlikely(up->pending)) {
813 		/* The socket is already corked while preparing it. */
814 		/* ... which is an evident application bug. --ANK */
815 		release_sock(sk);
816 
817 		LIMIT_NETDEBUG(KERN_DEBUG "udp cork app bug 2\n");
818 		err = -EINVAL;
819 		goto out;
820 	}
821 
822 	up->pending = AF_INET6;
823 
824 do_append_data:
825 	up->len += ulen;
826 	getfrag  =  is_udplite ?  udplite_getfrag : ip_generic_getfrag;
827 	err = ip6_append_data(sk, getfrag, msg->msg_iov, ulen,
828 		sizeof(struct udphdr), hlimit, tclass, opt, &fl,
829 		(struct rt6_info*)dst,
830 		corkreq ? msg->msg_flags|MSG_MORE : msg->msg_flags);
831 	if (err)
832 		udp_v6_flush_pending_frames(sk);
833 	else if (!corkreq)
834 		err = udp_v6_push_pending_frames(sk);
835 	else if (unlikely(skb_queue_empty(&sk->sk_write_queue)))
836 		up->pending = 0;
837 
838 	if (dst) {
839 		if (connected) {
840 			ip6_dst_store(sk, dst,
841 				      ipv6_addr_equal(&fl.fl6_dst, &np->daddr) ?
842 				      &np->daddr : NULL,
843 #ifdef CONFIG_IPV6_SUBTREES
844 				      ipv6_addr_equal(&fl.fl6_src, &np->saddr) ?
845 				      &np->saddr :
846 #endif
847 				      NULL);
848 		} else {
849 			dst_release(dst);
850 		}
851 	}
852 
853 	if (err > 0)
854 		err = np->recverr ? net_xmit_errno(err) : 0;
855 	release_sock(sk);
856 out:
857 	fl6_sock_release(flowlabel);
858 	if (!err)
859 		return len;
860 	/*
861 	 * ENOBUFS = no kernel mem, SOCK_NOSPACE = no sndbuf space.  Reporting
862 	 * ENOBUFS might not be good (it's not tunable per se), but otherwise
863 	 * we don't have a good statistic (IpOutDiscards but it can be too many
864 	 * things).  We could add another new stat but at least for now that
865 	 * seems like overkill.
866 	 */
867 	if (err == -ENOBUFS || test_bit(SOCK_NOSPACE, &sk->sk_socket->flags)) {
868 		UDP6_INC_STATS_USER(UDP_MIB_SNDBUFERRORS, is_udplite);
869 	}
870 	return err;
871 
872 do_confirm:
873 	dst_confirm(dst);
874 	if (!(msg->msg_flags&MSG_PROBE) || len)
875 		goto back_from_confirm;
876 	err = 0;
877 	goto out;
878 }
879 
880 int udpv6_destroy_sock(struct sock *sk)
881 {
882 	lock_sock(sk);
883 	udp_v6_flush_pending_frames(sk);
884 	release_sock(sk);
885 
886 	inet6_destroy_sock(sk);
887 
888 	return 0;
889 }
890 
891 /*
892  *	Socket option code for UDP
893  */
894 int udpv6_setsockopt(struct sock *sk, int level, int optname,
895 		     char __user *optval, int optlen)
896 {
897 	if (level == SOL_UDP  ||  level == SOL_UDPLITE)
898 		return udp_lib_setsockopt(sk, level, optname, optval, optlen,
899 					  udp_v6_push_pending_frames);
900 	return ipv6_setsockopt(sk, level, optname, optval, optlen);
901 }
902 
903 #ifdef CONFIG_COMPAT
904 int compat_udpv6_setsockopt(struct sock *sk, int level, int optname,
905 			    char __user *optval, int optlen)
906 {
907 	if (level == SOL_UDP  ||  level == SOL_UDPLITE)
908 		return udp_lib_setsockopt(sk, level, optname, optval, optlen,
909 					  udp_v6_push_pending_frames);
910 	return compat_ipv6_setsockopt(sk, level, optname, optval, optlen);
911 }
912 #endif
913 
914 int udpv6_getsockopt(struct sock *sk, int level, int optname,
915 		     char __user *optval, int __user *optlen)
916 {
917 	if (level == SOL_UDP  ||  level == SOL_UDPLITE)
918 		return udp_lib_getsockopt(sk, level, optname, optval, optlen);
919 	return ipv6_getsockopt(sk, level, optname, optval, optlen);
920 }
921 
922 #ifdef CONFIG_COMPAT
923 int compat_udpv6_getsockopt(struct sock *sk, int level, int optname,
924 			    char __user *optval, int __user *optlen)
925 {
926 	if (level == SOL_UDP  ||  level == SOL_UDPLITE)
927 		return udp_lib_getsockopt(sk, level, optname, optval, optlen);
928 	return compat_ipv6_getsockopt(sk, level, optname, optval, optlen);
929 }
930 #endif
931 
932 static struct inet6_protocol udpv6_protocol = {
933 	.handler	=	udpv6_rcv,
934 	.err_handler	=	udpv6_err,
935 	.flags		=	INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
936 };
937 
938 /* ------------------------------------------------------------------------ */
939 #ifdef CONFIG_PROC_FS
940 
941 static void udp6_sock_seq_show(struct seq_file *seq, struct sock *sp, int bucket)
942 {
943 	struct inet_sock *inet = inet_sk(sp);
944 	struct ipv6_pinfo *np = inet6_sk(sp);
945 	struct in6_addr *dest, *src;
946 	__u16 destp, srcp;
947 
948 	dest  = &np->daddr;
949 	src   = &np->rcv_saddr;
950 	destp = ntohs(inet->dport);
951 	srcp  = ntohs(inet->sport);
952 	seq_printf(seq,
953 		   "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
954 		   "%02X %08X:%08X %02X:%08lX %08X %5d %8d %lu %d %p\n",
955 		   bucket,
956 		   src->s6_addr32[0], src->s6_addr32[1],
957 		   src->s6_addr32[2], src->s6_addr32[3], srcp,
958 		   dest->s6_addr32[0], dest->s6_addr32[1],
959 		   dest->s6_addr32[2], dest->s6_addr32[3], destp,
960 		   sp->sk_state,
961 		   atomic_read(&sp->sk_wmem_alloc),
962 		   atomic_read(&sp->sk_rmem_alloc),
963 		   0, 0L, 0,
964 		   sock_i_uid(sp), 0,
965 		   sock_i_ino(sp),
966 		   atomic_read(&sp->sk_refcnt), sp);
967 }
968 
969 int udp6_seq_show(struct seq_file *seq, void *v)
970 {
971 	if (v == SEQ_START_TOKEN)
972 		seq_printf(seq,
973 			   "  sl  "
974 			   "local_address                         "
975 			   "remote_address                        "
976 			   "st tx_queue rx_queue tr tm->when retrnsmt"
977 			   "   uid  timeout inode\n");
978 	else
979 		udp6_sock_seq_show(seq, v, ((struct udp_iter_state *)seq->private)->bucket);
980 	return 0;
981 }
982 
983 static struct udp_seq_afinfo udp6_seq_afinfo = {
984 	.name		= "udp6",
985 	.family		= AF_INET6,
986 	.hashtable	= udp_hash,
987 	.seq_fops	= {
988 		.owner	=	THIS_MODULE,
989 	},
990 	.seq_ops	= {
991 		.show		= udp6_seq_show,
992 	},
993 };
994 
995 int udp6_proc_init(struct net *net)
996 {
997 	return udp_proc_register(net, &udp6_seq_afinfo);
998 }
999 
1000 void udp6_proc_exit(struct net *net) {
1001 	udp_proc_unregister(net, &udp6_seq_afinfo);
1002 }
1003 #endif /* CONFIG_PROC_FS */
1004 
1005 /* ------------------------------------------------------------------------ */
1006 
1007 struct proto udpv6_prot = {
1008 	.name		   = "UDPv6",
1009 	.owner		   = THIS_MODULE,
1010 	.close		   = udp_lib_close,
1011 	.connect	   = ip6_datagram_connect,
1012 	.disconnect	   = udp_disconnect,
1013 	.ioctl		   = udp_ioctl,
1014 	.destroy	   = udpv6_destroy_sock,
1015 	.setsockopt	   = udpv6_setsockopt,
1016 	.getsockopt	   = udpv6_getsockopt,
1017 	.sendmsg	   = udpv6_sendmsg,
1018 	.recvmsg	   = udpv6_recvmsg,
1019 	.backlog_rcv	   = udpv6_queue_rcv_skb,
1020 	.hash		   = udp_lib_hash,
1021 	.unhash		   = udp_lib_unhash,
1022 	.get_port	   = udp_v6_get_port,
1023 	.memory_allocated  = &udp_memory_allocated,
1024 	.sysctl_mem	   = sysctl_udp_mem,
1025 	.sysctl_wmem	   = &sysctl_udp_wmem_min,
1026 	.sysctl_rmem	   = &sysctl_udp_rmem_min,
1027 	.obj_size	   = sizeof(struct udp6_sock),
1028 	.h.udp_hash	   = udp_hash,
1029 #ifdef CONFIG_COMPAT
1030 	.compat_setsockopt = compat_udpv6_setsockopt,
1031 	.compat_getsockopt = compat_udpv6_getsockopt,
1032 #endif
1033 };
1034 
1035 static struct inet_protosw udpv6_protosw = {
1036 	.type =      SOCK_DGRAM,
1037 	.protocol =  IPPROTO_UDP,
1038 	.prot =      &udpv6_prot,
1039 	.ops =       &inet6_dgram_ops,
1040 	.capability =-1,
1041 	.no_check =  UDP_CSUM_DEFAULT,
1042 	.flags =     INET_PROTOSW_PERMANENT,
1043 };
1044 
1045 
1046 int __init udpv6_init(void)
1047 {
1048 	int ret;
1049 
1050 	ret = inet6_add_protocol(&udpv6_protocol, IPPROTO_UDP);
1051 	if (ret)
1052 		goto out;
1053 
1054 	ret = inet6_register_protosw(&udpv6_protosw);
1055 	if (ret)
1056 		goto out_udpv6_protocol;
1057 out:
1058 	return ret;
1059 
1060 out_udpv6_protocol:
1061 	inet6_del_protocol(&udpv6_protocol, IPPROTO_UDP);
1062 	goto out;
1063 }
1064 
1065 void udpv6_exit(void)
1066 {
1067 	inet6_unregister_protosw(&udpv6_protosw);
1068 	inet6_del_protocol(&udpv6_protocol, IPPROTO_UDP);
1069 }
1070