xref: /openbmc/linux/net/ipv6/udp.c (revision 64c70b1c)
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/skbuff.h>
38 #include <asm/uaccess.h>
39 
40 #include <net/ndisc.h>
41 #include <net/protocol.h>
42 #include <net/transp_v6.h>
43 #include <net/ip6_route.h>
44 #include <net/raw.h>
45 #include <net/tcp_states.h>
46 #include <net/ip6_checksum.h>
47 #include <net/xfrm.h>
48 
49 #include <linux/proc_fs.h>
50 #include <linux/seq_file.h>
51 #include "udp_impl.h"
52 
53 DEFINE_SNMP_STAT(struct udp_mib, udp_stats_in6) __read_mostly;
54 
55 static inline int udp_v6_get_port(struct sock *sk, unsigned short snum)
56 {
57 	return udp_get_port(sk, snum, ipv6_rcv_saddr_equal);
58 }
59 
60 static struct sock *__udp6_lib_lookup(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_hash == hnum && sk->sk_family == PF_INET6) {
74 			struct ipv6_pinfo *np = inet6_sk(sk);
75 			int score = 0;
76 			if (inet->dport) {
77 				if (inet->dport != sport)
78 					continue;
79 				score++;
80 			}
81 			if (!ipv6_addr_any(&np->rcv_saddr)) {
82 				if (!ipv6_addr_equal(&np->rcv_saddr, daddr))
83 					continue;
84 				score++;
85 			}
86 			if (!ipv6_addr_any(&np->daddr)) {
87 				if (!ipv6_addr_equal(&np->daddr, saddr))
88 					continue;
89 				score++;
90 			}
91 			if (sk->sk_bound_dev_if) {
92 				if (sk->sk_bound_dev_if != dif)
93 					continue;
94 				score++;
95 			}
96 			if (score == 4) {
97 				result = sk;
98 				break;
99 			} else if (score > badness) {
100 				result = sk;
101 				badness = score;
102 			}
103 		}
104 	}
105 	if (result)
106 		sock_hold(result);
107 	read_unlock(&udp_hash_lock);
108 	return result;
109 }
110 
111 /*
112  * 	This should be easy, if there is something there we
113  * 	return it, otherwise we block.
114  */
115 
116 int udpv6_recvmsg(struct kiocb *iocb, struct sock *sk,
117 		  struct msghdr *msg, size_t len,
118 		  int noblock, int flags, int *addr_len)
119 {
120 	struct ipv6_pinfo *np = inet6_sk(sk);
121 	struct inet_sock *inet = inet_sk(sk);
122 	struct sk_buff *skb;
123 	unsigned int ulen, copied;
124 	int err;
125 	int is_udplite = IS_UDPLITE(sk);
126 
127 	if (addr_len)
128 		*addr_len=sizeof(struct sockaddr_in6);
129 
130 	if (flags & MSG_ERRQUEUE)
131 		return ipv6_recv_error(sk, msg, len);
132 
133 try_again:
134 	skb = skb_recv_datagram(sk, flags, noblock, &err);
135 	if (!skb)
136 		goto out;
137 
138 	ulen = skb->len - sizeof(struct udphdr);
139 	copied = len;
140 	if (copied > ulen)
141 		copied = ulen;
142 	else if (copied < ulen)
143 		msg->msg_flags |= MSG_TRUNC;
144 
145 	/*
146 	 * If checksum is needed at all, try to do it while copying the
147 	 * data.  If the data is truncated, or if we only want a partial
148 	 * coverage checksum (UDP-Lite), do it before the copy.
149 	 */
150 
151 	if (copied < ulen || UDP_SKB_CB(skb)->partial_cov) {
152 		if (udp_lib_checksum_complete(skb))
153 			goto csum_copy_err;
154 	}
155 
156 	if (skb_csum_unnecessary(skb))
157 		err = skb_copy_datagram_iovec(skb, sizeof(struct udphdr),
158 					      msg->msg_iov, copied       );
159 	else {
160 		err = skb_copy_and_csum_datagram_iovec(skb, sizeof(struct udphdr), msg->msg_iov);
161 		if (err == -EINVAL)
162 			goto csum_copy_err;
163 	}
164 	if (err)
165 		goto out_free;
166 
167 	sock_recv_timestamp(msg, sk, skb);
168 
169 	/* Copy the address. */
170 	if (msg->msg_name) {
171 		struct sockaddr_in6 *sin6;
172 
173 		sin6 = (struct sockaddr_in6 *) msg->msg_name;
174 		sin6->sin6_family = AF_INET6;
175 		sin6->sin6_port = udp_hdr(skb)->source;
176 		sin6->sin6_flowinfo = 0;
177 		sin6->sin6_scope_id = 0;
178 
179 		if (skb->protocol == htons(ETH_P_IP))
180 			ipv6_addr_set(&sin6->sin6_addr, 0, 0,
181 				      htonl(0xffff), ip_hdr(skb)->saddr);
182 		else {
183 			ipv6_addr_copy(&sin6->sin6_addr,
184 				       &ipv6_hdr(skb)->saddr);
185 			if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL)
186 				sin6->sin6_scope_id = IP6CB(skb)->iif;
187 		}
188 
189 	}
190 	if (skb->protocol == htons(ETH_P_IP)) {
191 		if (inet->cmsg_flags)
192 			ip_cmsg_recv(msg, skb);
193 	} else {
194 		if (np->rxopt.all)
195 			datagram_recv_ctl(sk, msg, skb);
196 	}
197 
198 	err = copied;
199 	if (flags & MSG_TRUNC)
200 		err = ulen;
201 
202 out_free:
203 	skb_free_datagram(sk, skb);
204 out:
205 	return err;
206 
207 csum_copy_err:
208 	skb_kill_datagram(sk, skb, flags);
209 
210 	if (flags & MSG_DONTWAIT) {
211 		UDP6_INC_STATS_USER(UDP_MIB_INERRORS, is_udplite);
212 		return -EAGAIN;
213 	}
214 	goto try_again;
215 }
216 
217 void __udp6_lib_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
218 		    int type, int code, int offset, __be32 info,
219 		    struct hlist_head udptable[]                    )
220 {
221 	struct ipv6_pinfo *np;
222 	struct ipv6hdr *hdr = (struct ipv6hdr*)skb->data;
223 	struct in6_addr *saddr = &hdr->saddr;
224 	struct in6_addr *daddr = &hdr->daddr;
225 	struct udphdr *uh = (struct udphdr*)(skb->data+offset);
226 	struct sock *sk;
227 	int err;
228 
229 	sk = __udp6_lib_lookup(daddr, uh->dest,
230 			       saddr, uh->source, inet6_iif(skb), udptable);
231 	if (sk == NULL)
232 		return;
233 
234 	np = inet6_sk(sk);
235 
236 	if (!icmpv6_err_convert(type, code, &err) && !np->recverr)
237 		goto out;
238 
239 	if (sk->sk_state != TCP_ESTABLISHED && !np->recverr)
240 		goto out;
241 
242 	if (np->recverr)
243 		ipv6_icmp_error(sk, skb, err, uh->dest, ntohl(info), (u8 *)(uh+1));
244 
245 	sk->sk_err = err;
246 	sk->sk_error_report(sk);
247 out:
248 	sock_put(sk);
249 }
250 
251 static __inline__ void udpv6_err(struct sk_buff *skb,
252 				 struct inet6_skb_parm *opt, int type,
253 				 int code, int offset, __be32 info     )
254 {
255 	return __udp6_lib_err(skb, opt, type, code, offset, info, udp_hash);
256 }
257 
258 int udpv6_queue_rcv_skb(struct sock * sk, struct sk_buff *skb)
259 {
260 	struct udp_sock *up = udp_sk(sk);
261 	int rc;
262 
263 	if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
264 		goto drop;
265 
266 	/*
267 	 * UDP-Lite specific tests, ignored on UDP sockets (see net/ipv4/udp.c).
268 	 */
269 	if ((up->pcflag & UDPLITE_RECV_CC)  &&  UDP_SKB_CB(skb)->partial_cov) {
270 
271 		if (up->pcrlen == 0) {          /* full coverage was set  */
272 			LIMIT_NETDEBUG(KERN_WARNING "UDPLITE6: partial coverage"
273 				" %d while full coverage %d requested\n",
274 				UDP_SKB_CB(skb)->cscov, skb->len);
275 			goto drop;
276 		}
277 		if (UDP_SKB_CB(skb)->cscov  <  up->pcrlen) {
278 			LIMIT_NETDEBUG(KERN_WARNING "UDPLITE6: coverage %d "
279 						    "too small, need min %d\n",
280 				       UDP_SKB_CB(skb)->cscov, up->pcrlen);
281 			goto drop;
282 		}
283 	}
284 
285 	if (sk->sk_filter) {
286 		if (udp_lib_checksum_complete(skb))
287 			goto drop;
288 	}
289 
290 	if ((rc = sock_queue_rcv_skb(sk,skb)) < 0) {
291 		/* Note that an ENOMEM error is charged twice */
292 		if (rc == -ENOMEM)
293 			UDP6_INC_STATS_BH(UDP_MIB_RCVBUFERRORS, up->pcflag);
294 		goto drop;
295 	}
296 	UDP6_INC_STATS_BH(UDP_MIB_INDATAGRAMS, up->pcflag);
297 	return 0;
298 drop:
299 	UDP6_INC_STATS_BH(UDP_MIB_INERRORS, up->pcflag);
300 	kfree_skb(skb);
301 	return -1;
302 }
303 
304 static struct sock *udp_v6_mcast_next(struct sock *sk,
305 				      __be16 loc_port, struct in6_addr *loc_addr,
306 				      __be16 rmt_port, struct in6_addr *rmt_addr,
307 				      int dif)
308 {
309 	struct hlist_node *node;
310 	struct sock *s = sk;
311 	unsigned short num = ntohs(loc_port);
312 
313 	sk_for_each_from(s, node) {
314 		struct inet_sock *inet = inet_sk(s);
315 
316 		if (s->sk_hash == num && s->sk_family == PF_INET6) {
317 			struct ipv6_pinfo *np = inet6_sk(s);
318 			if (inet->dport) {
319 				if (inet->dport != rmt_port)
320 					continue;
321 			}
322 			if (!ipv6_addr_any(&np->daddr) &&
323 			    !ipv6_addr_equal(&np->daddr, rmt_addr))
324 				continue;
325 
326 			if (s->sk_bound_dev_if && s->sk_bound_dev_if != dif)
327 				continue;
328 
329 			if (!ipv6_addr_any(&np->rcv_saddr)) {
330 				if (!ipv6_addr_equal(&np->rcv_saddr, loc_addr))
331 					continue;
332 			}
333 			if (!inet6_mc_check(s, loc_addr, rmt_addr))
334 				continue;
335 			return s;
336 		}
337 	}
338 	return NULL;
339 }
340 
341 /*
342  * Note: called only from the BH handler context,
343  * so we don't need to lock the hashes.
344  */
345 static int __udp6_lib_mcast_deliver(struct sk_buff *skb, struct in6_addr *saddr,
346 			   struct in6_addr *daddr, struct hlist_head udptable[])
347 {
348 	struct sock *sk, *sk2;
349 	const struct udphdr *uh = udp_hdr(skb);
350 	int dif;
351 
352 	read_lock(&udp_hash_lock);
353 	sk = sk_head(&udptable[ntohs(uh->dest) & (UDP_HTABLE_SIZE - 1)]);
354 	dif = inet6_iif(skb);
355 	sk = udp_v6_mcast_next(sk, uh->dest, daddr, uh->source, saddr, dif);
356 	if (!sk) {
357 		kfree_skb(skb);
358 		goto out;
359 	}
360 
361 	sk2 = sk;
362 	while ((sk2 = udp_v6_mcast_next(sk_next(sk2), uh->dest, daddr,
363 					uh->source, saddr, dif))) {
364 		struct sk_buff *buff = skb_clone(skb, GFP_ATOMIC);
365 		if (buff)
366 			udpv6_queue_rcv_skb(sk2, buff);
367 	}
368 	udpv6_queue_rcv_skb(sk, skb);
369 out:
370 	read_unlock(&udp_hash_lock);
371 	return 0;
372 }
373 
374 static inline int udp6_csum_init(struct sk_buff *skb, struct udphdr *uh,
375 				 int proto)
376 {
377 	int err;
378 
379 	UDP_SKB_CB(skb)->partial_cov = 0;
380 	UDP_SKB_CB(skb)->cscov = skb->len;
381 
382 	if (proto == IPPROTO_UDPLITE) {
383 		err = udplite_checksum_init(skb, uh);
384 		if (err)
385 			return err;
386 	}
387 
388 	if (uh->check == 0) {
389 		/* RFC 2460 section 8.1 says that we SHOULD log
390 		   this error. Well, it is reasonable.
391 		 */
392 		LIMIT_NETDEBUG(KERN_INFO "IPv6: udp checksum is 0\n");
393 		return 1;
394 	}
395 	if (skb->ip_summed == CHECKSUM_COMPLETE &&
396 	    !csum_ipv6_magic(&ipv6_hdr(skb)->saddr, &ipv6_hdr(skb)->daddr,
397 			     skb->len, proto, skb->csum))
398 		skb->ip_summed = CHECKSUM_UNNECESSARY;
399 
400 	if (!skb_csum_unnecessary(skb))
401 		skb->csum = ~csum_unfold(csum_ipv6_magic(&ipv6_hdr(skb)->saddr,
402 							 &ipv6_hdr(skb)->daddr,
403 							 skb->len, proto, 0));
404 
405 	return 0;
406 }
407 
408 int __udp6_lib_rcv(struct sk_buff **pskb, struct hlist_head udptable[],
409 		   int proto)
410 {
411 	struct sk_buff *skb = *pskb;
412 	struct sock *sk;
413 	struct udphdr *uh;
414 	struct net_device *dev = skb->dev;
415 	struct in6_addr *saddr, *daddr;
416 	u32 ulen = 0;
417 
418 	if (!pskb_may_pull(skb, sizeof(struct udphdr)))
419 		goto short_packet;
420 
421 	saddr = &ipv6_hdr(skb)->saddr;
422 	daddr = &ipv6_hdr(skb)->daddr;
423 	uh = udp_hdr(skb);
424 
425 	ulen = ntohs(uh->len);
426 	if (ulen > skb->len)
427 		goto short_packet;
428 
429 	if (proto == IPPROTO_UDP) {
430 		/* UDP validates ulen. */
431 
432 		/* Check for jumbo payload */
433 		if (ulen == 0)
434 			ulen = skb->len;
435 
436 		if (ulen < sizeof(*uh))
437 			goto short_packet;
438 
439 		if (ulen < skb->len) {
440 			if (pskb_trim_rcsum(skb, ulen))
441 				goto short_packet;
442 			saddr = &ipv6_hdr(skb)->saddr;
443 			daddr = &ipv6_hdr(skb)->daddr;
444 			uh = udp_hdr(skb);
445 		}
446 	}
447 
448 	if (udp6_csum_init(skb, uh, proto))
449 		goto discard;
450 
451 	/*
452 	 *	Multicast receive code
453 	 */
454 	if (ipv6_addr_is_multicast(daddr))
455 		return __udp6_lib_mcast_deliver(skb, saddr, daddr, udptable);
456 
457 	/* Unicast */
458 
459 	/*
460 	 * check socket cache ... must talk to Alan about his plans
461 	 * for sock caches... i'll skip this for now.
462 	 */
463 	sk = __udp6_lib_lookup(saddr, uh->source,
464 			       daddr, uh->dest, inet6_iif(skb), udptable);
465 
466 	if (sk == NULL) {
467 		if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
468 			goto discard;
469 
470 		if (udp_lib_checksum_complete(skb))
471 			goto discard;
472 		UDP6_INC_STATS_BH(UDP_MIB_NOPORTS, proto == IPPROTO_UDPLITE);
473 
474 		icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0, dev);
475 
476 		kfree_skb(skb);
477 		return 0;
478 	}
479 
480 	/* deliver */
481 
482 	udpv6_queue_rcv_skb(sk, skb);
483 	sock_put(sk);
484 	return 0;
485 
486 short_packet:
487 	LIMIT_NETDEBUG(KERN_DEBUG "UDP%sv6: short packet: %d/%u\n",
488 		       proto == IPPROTO_UDPLITE ? "-Lite" : "",
489 		       ulen, skb->len);
490 
491 discard:
492 	UDP6_INC_STATS_BH(UDP_MIB_INERRORS, proto == IPPROTO_UDPLITE);
493 	kfree_skb(skb);
494 	return 0;
495 }
496 
497 static __inline__ int udpv6_rcv(struct sk_buff **pskb)
498 {
499 	return __udp6_lib_rcv(pskb, udp_hash, IPPROTO_UDP);
500 }
501 
502 /*
503  * Throw away all pending data and cancel the corking. Socket is locked.
504  */
505 static void udp_v6_flush_pending_frames(struct sock *sk)
506 {
507 	struct udp_sock *up = udp_sk(sk);
508 
509 	if (up->pending) {
510 		up->len = 0;
511 		up->pending = 0;
512 		ip6_flush_pending_frames(sk);
513 	}
514 }
515 
516 /*
517  *	Sending
518  */
519 
520 static int udp_v6_push_pending_frames(struct sock *sk)
521 {
522 	struct sk_buff *skb;
523 	struct udphdr *uh;
524 	struct udp_sock  *up = udp_sk(sk);
525 	struct inet_sock *inet = inet_sk(sk);
526 	struct flowi *fl = &inet->cork.fl;
527 	int err = 0;
528 	__wsum csum = 0;
529 
530 	/* Grab the skbuff where UDP header space exists. */
531 	if ((skb = skb_peek(&sk->sk_write_queue)) == NULL)
532 		goto out;
533 
534 	/*
535 	 * Create a UDP header
536 	 */
537 	uh = udp_hdr(skb);
538 	uh->source = fl->fl_ip_sport;
539 	uh->dest = fl->fl_ip_dport;
540 	uh->len = htons(up->len);
541 	uh->check = 0;
542 
543 	if (up->pcflag)
544 		csum = udplite_csum_outgoing(sk, skb);
545 	 else
546 		csum = udp_csum_outgoing(sk, skb);
547 
548 	/* add protocol-dependent pseudo-header */
549 	uh->check = csum_ipv6_magic(&fl->fl6_src, &fl->fl6_dst,
550 				    up->len, fl->proto, csum   );
551 	if (uh->check == 0)
552 		uh->check = CSUM_MANGLED_0;
553 
554 	err = ip6_push_pending_frames(sk);
555 out:
556 	up->len = 0;
557 	up->pending = 0;
558 	return err;
559 }
560 
561 int udpv6_sendmsg(struct kiocb *iocb, struct sock *sk,
562 		  struct msghdr *msg, size_t len)
563 {
564 	struct ipv6_txoptions opt_space;
565 	struct udp_sock *up = udp_sk(sk);
566 	struct inet_sock *inet = inet_sk(sk);
567 	struct ipv6_pinfo *np = inet6_sk(sk);
568 	struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *) msg->msg_name;
569 	struct in6_addr *daddr, *final_p = NULL, final;
570 	struct ipv6_txoptions *opt = NULL;
571 	struct ip6_flowlabel *flowlabel = NULL;
572 	struct flowi fl;
573 	struct dst_entry *dst;
574 	int addr_len = msg->msg_namelen;
575 	int ulen = len;
576 	int hlimit = -1;
577 	int tclass = -1;
578 	int corkreq = up->corkflag || msg->msg_flags&MSG_MORE;
579 	int err;
580 	int connected = 0;
581 	int is_udplite = up->pcflag;
582 	int (*getfrag)(void *, char *, int, int, int, struct sk_buff *);
583 
584 	/* destination address check */
585 	if (sin6) {
586 		if (addr_len < offsetof(struct sockaddr, sa_data))
587 			return -EINVAL;
588 
589 		switch (sin6->sin6_family) {
590 		case AF_INET6:
591 			if (addr_len < SIN6_LEN_RFC2133)
592 				return -EINVAL;
593 			daddr = &sin6->sin6_addr;
594 			break;
595 		case AF_INET:
596 			goto do_udp_sendmsg;
597 		case AF_UNSPEC:
598 			msg->msg_name = sin6 = NULL;
599 			msg->msg_namelen = addr_len = 0;
600 			daddr = NULL;
601 			break;
602 		default:
603 			return -EINVAL;
604 		}
605 	} else if (!up->pending) {
606 		if (sk->sk_state != TCP_ESTABLISHED)
607 			return -EDESTADDRREQ;
608 		daddr = &np->daddr;
609 	} else
610 		daddr = NULL;
611 
612 	if (daddr) {
613 		if (ipv6_addr_type(daddr) == IPV6_ADDR_MAPPED) {
614 			struct sockaddr_in sin;
615 			sin.sin_family = AF_INET;
616 			sin.sin_port = sin6 ? sin6->sin6_port : inet->dport;
617 			sin.sin_addr.s_addr = daddr->s6_addr32[3];
618 			msg->msg_name = &sin;
619 			msg->msg_namelen = sizeof(sin);
620 do_udp_sendmsg:
621 			if (__ipv6_only_sock(sk))
622 				return -ENETUNREACH;
623 			return udp_sendmsg(iocb, sk, msg, len);
624 		}
625 	}
626 
627 	if (up->pending == AF_INET)
628 		return udp_sendmsg(iocb, sk, msg, len);
629 
630 	/* Rough check on arithmetic overflow,
631 	   better check is made in ip6_append_data().
632 	   */
633 	if (len > INT_MAX - sizeof(struct udphdr))
634 		return -EMSGSIZE;
635 
636 	if (up->pending) {
637 		/*
638 		 * There are pending frames.
639 		 * The socket lock must be held while it's corked.
640 		 */
641 		lock_sock(sk);
642 		if (likely(up->pending)) {
643 			if (unlikely(up->pending != AF_INET6)) {
644 				release_sock(sk);
645 				return -EAFNOSUPPORT;
646 			}
647 			dst = NULL;
648 			goto do_append_data;
649 		}
650 		release_sock(sk);
651 	}
652 	ulen += sizeof(struct udphdr);
653 
654 	memset(&fl, 0, sizeof(fl));
655 
656 	if (sin6) {
657 		if (sin6->sin6_port == 0)
658 			return -EINVAL;
659 
660 		fl.fl_ip_dport = sin6->sin6_port;
661 		daddr = &sin6->sin6_addr;
662 
663 		if (np->sndflow) {
664 			fl.fl6_flowlabel = sin6->sin6_flowinfo&IPV6_FLOWINFO_MASK;
665 			if (fl.fl6_flowlabel&IPV6_FLOWLABEL_MASK) {
666 				flowlabel = fl6_sock_lookup(sk, fl.fl6_flowlabel);
667 				if (flowlabel == NULL)
668 					return -EINVAL;
669 				daddr = &flowlabel->dst;
670 			}
671 		}
672 
673 		/*
674 		 * Otherwise it will be difficult to maintain
675 		 * sk->sk_dst_cache.
676 		 */
677 		if (sk->sk_state == TCP_ESTABLISHED &&
678 		    ipv6_addr_equal(daddr, &np->daddr))
679 			daddr = &np->daddr;
680 
681 		if (addr_len >= sizeof(struct sockaddr_in6) &&
682 		    sin6->sin6_scope_id &&
683 		    ipv6_addr_type(daddr)&IPV6_ADDR_LINKLOCAL)
684 			fl.oif = sin6->sin6_scope_id;
685 	} else {
686 		if (sk->sk_state != TCP_ESTABLISHED)
687 			return -EDESTADDRREQ;
688 
689 		fl.fl_ip_dport = inet->dport;
690 		daddr = &np->daddr;
691 		fl.fl6_flowlabel = np->flow_label;
692 		connected = 1;
693 	}
694 
695 	if (!fl.oif)
696 		fl.oif = sk->sk_bound_dev_if;
697 
698 	if (msg->msg_controllen) {
699 		opt = &opt_space;
700 		memset(opt, 0, sizeof(struct ipv6_txoptions));
701 		opt->tot_len = sizeof(*opt);
702 
703 		err = datagram_send_ctl(msg, &fl, opt, &hlimit, &tclass);
704 		if (err < 0) {
705 			fl6_sock_release(flowlabel);
706 			return err;
707 		}
708 		if ((fl.fl6_flowlabel&IPV6_FLOWLABEL_MASK) && !flowlabel) {
709 			flowlabel = fl6_sock_lookup(sk, fl.fl6_flowlabel);
710 			if (flowlabel == NULL)
711 				return -EINVAL;
712 		}
713 		if (!(opt->opt_nflen|opt->opt_flen))
714 			opt = NULL;
715 		connected = 0;
716 	}
717 	if (opt == NULL)
718 		opt = np->opt;
719 	if (flowlabel)
720 		opt = fl6_merge_options(&opt_space, flowlabel, opt);
721 	opt = ipv6_fixup_options(&opt_space, opt);
722 
723 	fl.proto = sk->sk_protocol;
724 	ipv6_addr_copy(&fl.fl6_dst, daddr);
725 	if (ipv6_addr_any(&fl.fl6_src) && !ipv6_addr_any(&np->saddr))
726 		ipv6_addr_copy(&fl.fl6_src, &np->saddr);
727 	fl.fl_ip_sport = inet->sport;
728 
729 	/* merge ip6_build_xmit from ip6_output */
730 	if (opt && opt->srcrt) {
731 		struct rt0_hdr *rt0 = (struct rt0_hdr *) opt->srcrt;
732 		ipv6_addr_copy(&final, &fl.fl6_dst);
733 		ipv6_addr_copy(&fl.fl6_dst, rt0->addr);
734 		final_p = &final;
735 		connected = 0;
736 	}
737 
738 	if (!fl.oif && ipv6_addr_is_multicast(&fl.fl6_dst)) {
739 		fl.oif = np->mcast_oif;
740 		connected = 0;
741 	}
742 
743 	security_sk_classify_flow(sk, &fl);
744 
745 	err = ip6_sk_dst_lookup(sk, &dst, &fl);
746 	if (err)
747 		goto out;
748 	if (final_p)
749 		ipv6_addr_copy(&fl.fl6_dst, final_p);
750 
751 	if ((err = __xfrm_lookup(&dst, &fl, sk, 1)) < 0) {
752 		if (err == -EREMOTE)
753 			err = ip6_dst_blackhole(sk, &dst, &fl);
754 		if (err < 0)
755 			goto out;
756 	}
757 
758 	if (hlimit < 0) {
759 		if (ipv6_addr_is_multicast(&fl.fl6_dst))
760 			hlimit = np->mcast_hops;
761 		else
762 			hlimit = np->hop_limit;
763 		if (hlimit < 0)
764 			hlimit = dst_metric(dst, RTAX_HOPLIMIT);
765 		if (hlimit < 0)
766 			hlimit = ipv6_get_hoplimit(dst->dev);
767 	}
768 
769 	if (tclass < 0) {
770 		tclass = np->tclass;
771 		if (tclass < 0)
772 			tclass = 0;
773 	}
774 
775 	if (msg->msg_flags&MSG_CONFIRM)
776 		goto do_confirm;
777 back_from_confirm:
778 
779 	lock_sock(sk);
780 	if (unlikely(up->pending)) {
781 		/* The socket is already corked while preparing it. */
782 		/* ... which is an evident application bug. --ANK */
783 		release_sock(sk);
784 
785 		LIMIT_NETDEBUG(KERN_DEBUG "udp cork app bug 2\n");
786 		err = -EINVAL;
787 		goto out;
788 	}
789 
790 	up->pending = AF_INET6;
791 
792 do_append_data:
793 	up->len += ulen;
794 	getfrag  =  is_udplite ?  udplite_getfrag : ip_generic_getfrag;
795 	err = ip6_append_data(sk, getfrag, msg->msg_iov, ulen,
796 		sizeof(struct udphdr), hlimit, tclass, opt, &fl,
797 		(struct rt6_info*)dst,
798 		corkreq ? msg->msg_flags|MSG_MORE : msg->msg_flags);
799 	if (err)
800 		udp_v6_flush_pending_frames(sk);
801 	else if (!corkreq)
802 		err = udp_v6_push_pending_frames(sk);
803 	else if (unlikely(skb_queue_empty(&sk->sk_write_queue)))
804 		up->pending = 0;
805 
806 	if (dst) {
807 		if (connected) {
808 			ip6_dst_store(sk, dst,
809 				      ipv6_addr_equal(&fl.fl6_dst, &np->daddr) ?
810 				      &np->daddr : NULL,
811 #ifdef CONFIG_IPV6_SUBTREES
812 				      ipv6_addr_equal(&fl.fl6_src, &np->saddr) ?
813 				      &np->saddr :
814 #endif
815 				      NULL);
816 		} else {
817 			dst_release(dst);
818 		}
819 	}
820 
821 	if (err > 0)
822 		err = np->recverr ? net_xmit_errno(err) : 0;
823 	release_sock(sk);
824 out:
825 	fl6_sock_release(flowlabel);
826 	if (!err) {
827 		UDP6_INC_STATS_USER(UDP_MIB_OUTDATAGRAMS, is_udplite);
828 		return len;
829 	}
830 	/*
831 	 * ENOBUFS = no kernel mem, SOCK_NOSPACE = no sndbuf space.  Reporting
832 	 * ENOBUFS might not be good (it's not tunable per se), but otherwise
833 	 * we don't have a good statistic (IpOutDiscards but it can be too many
834 	 * things).  We could add another new stat but at least for now that
835 	 * seems like overkill.
836 	 */
837 	if (err == -ENOBUFS || test_bit(SOCK_NOSPACE, &sk->sk_socket->flags)) {
838 		UDP6_INC_STATS_USER(UDP_MIB_SNDBUFERRORS, is_udplite);
839 	}
840 	return err;
841 
842 do_confirm:
843 	dst_confirm(dst);
844 	if (!(msg->msg_flags&MSG_PROBE) || len)
845 		goto back_from_confirm;
846 	err = 0;
847 	goto out;
848 }
849 
850 int udpv6_destroy_sock(struct sock *sk)
851 {
852 	lock_sock(sk);
853 	udp_v6_flush_pending_frames(sk);
854 	release_sock(sk);
855 
856 	inet6_destroy_sock(sk);
857 
858 	return 0;
859 }
860 
861 /*
862  *	Socket option code for UDP
863  */
864 int udpv6_setsockopt(struct sock *sk, int level, int optname,
865 		     char __user *optval, int optlen)
866 {
867 	if (level == SOL_UDP  ||  level == SOL_UDPLITE)
868 		return udp_lib_setsockopt(sk, level, optname, optval, optlen,
869 					  udp_v6_push_pending_frames);
870 	return ipv6_setsockopt(sk, level, optname, optval, optlen);
871 }
872 
873 #ifdef CONFIG_COMPAT
874 int compat_udpv6_setsockopt(struct sock *sk, int level, int optname,
875 			    char __user *optval, int optlen)
876 {
877 	if (level == SOL_UDP  ||  level == SOL_UDPLITE)
878 		return udp_lib_setsockopt(sk, level, optname, optval, optlen,
879 					  udp_v6_push_pending_frames);
880 	return compat_ipv6_setsockopt(sk, level, optname, optval, optlen);
881 }
882 #endif
883 
884 int udpv6_getsockopt(struct sock *sk, int level, int optname,
885 		     char __user *optval, int __user *optlen)
886 {
887 	if (level == SOL_UDP  ||  level == SOL_UDPLITE)
888 		return udp_lib_getsockopt(sk, level, optname, optval, optlen);
889 	return ipv6_getsockopt(sk, level, optname, optval, optlen);
890 }
891 
892 #ifdef CONFIG_COMPAT
893 int compat_udpv6_getsockopt(struct sock *sk, int level, int optname,
894 			    char __user *optval, int __user *optlen)
895 {
896 	if (level == SOL_UDP  ||  level == SOL_UDPLITE)
897 		return udp_lib_getsockopt(sk, level, optname, optval, optlen);
898 	return compat_ipv6_getsockopt(sk, level, optname, optval, optlen);
899 }
900 #endif
901 
902 static struct inet6_protocol udpv6_protocol = {
903 	.handler	=	udpv6_rcv,
904 	.err_handler	=	udpv6_err,
905 	.flags		=	INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
906 };
907 
908 /* ------------------------------------------------------------------------ */
909 #ifdef CONFIG_PROC_FS
910 
911 static void udp6_sock_seq_show(struct seq_file *seq, struct sock *sp, int bucket)
912 {
913 	struct inet_sock *inet = inet_sk(sp);
914 	struct ipv6_pinfo *np = inet6_sk(sp);
915 	struct in6_addr *dest, *src;
916 	__u16 destp, srcp;
917 
918 	dest  = &np->daddr;
919 	src   = &np->rcv_saddr;
920 	destp = ntohs(inet->dport);
921 	srcp  = ntohs(inet->sport);
922 	seq_printf(seq,
923 		   "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
924 		   "%02X %08X:%08X %02X:%08lX %08X %5d %8d %lu %d %p\n",
925 		   bucket,
926 		   src->s6_addr32[0], src->s6_addr32[1],
927 		   src->s6_addr32[2], src->s6_addr32[3], srcp,
928 		   dest->s6_addr32[0], dest->s6_addr32[1],
929 		   dest->s6_addr32[2], dest->s6_addr32[3], destp,
930 		   sp->sk_state,
931 		   atomic_read(&sp->sk_wmem_alloc),
932 		   atomic_read(&sp->sk_rmem_alloc),
933 		   0, 0L, 0,
934 		   sock_i_uid(sp), 0,
935 		   sock_i_ino(sp),
936 		   atomic_read(&sp->sk_refcnt), sp);
937 }
938 
939 int udp6_seq_show(struct seq_file *seq, void *v)
940 {
941 	if (v == SEQ_START_TOKEN)
942 		seq_printf(seq,
943 			   "  sl  "
944 			   "local_address                         "
945 			   "remote_address                        "
946 			   "st tx_queue rx_queue tr tm->when retrnsmt"
947 			   "   uid  timeout inode\n");
948 	else
949 		udp6_sock_seq_show(seq, v, ((struct udp_iter_state *)seq->private)->bucket);
950 	return 0;
951 }
952 
953 static struct file_operations udp6_seq_fops;
954 static struct udp_seq_afinfo udp6_seq_afinfo = {
955 	.owner		= THIS_MODULE,
956 	.name		= "udp6",
957 	.family		= AF_INET6,
958 	.hashtable	= udp_hash,
959 	.seq_show	= udp6_seq_show,
960 	.seq_fops	= &udp6_seq_fops,
961 };
962 
963 int __init udp6_proc_init(void)
964 {
965 	return udp_proc_register(&udp6_seq_afinfo);
966 }
967 
968 void udp6_proc_exit(void) {
969 	udp_proc_unregister(&udp6_seq_afinfo);
970 }
971 #endif /* CONFIG_PROC_FS */
972 
973 /* ------------------------------------------------------------------------ */
974 
975 struct proto udpv6_prot = {
976 	.name		   = "UDPv6",
977 	.owner		   = THIS_MODULE,
978 	.close		   = udp_lib_close,
979 	.connect	   = ip6_datagram_connect,
980 	.disconnect	   = udp_disconnect,
981 	.ioctl		   = udp_ioctl,
982 	.destroy	   = udpv6_destroy_sock,
983 	.setsockopt	   = udpv6_setsockopt,
984 	.getsockopt	   = udpv6_getsockopt,
985 	.sendmsg	   = udpv6_sendmsg,
986 	.recvmsg	   = udpv6_recvmsg,
987 	.backlog_rcv	   = udpv6_queue_rcv_skb,
988 	.hash		   = udp_lib_hash,
989 	.unhash		   = udp_lib_unhash,
990 	.get_port	   = udp_v6_get_port,
991 	.obj_size	   = sizeof(struct udp6_sock),
992 #ifdef CONFIG_COMPAT
993 	.compat_setsockopt = compat_udpv6_setsockopt,
994 	.compat_getsockopt = compat_udpv6_getsockopt,
995 #endif
996 };
997 
998 static struct inet_protosw udpv6_protosw = {
999 	.type =      SOCK_DGRAM,
1000 	.protocol =  IPPROTO_UDP,
1001 	.prot =      &udpv6_prot,
1002 	.ops =       &inet6_dgram_ops,
1003 	.capability =-1,
1004 	.no_check =  UDP_CSUM_DEFAULT,
1005 	.flags =     INET_PROTOSW_PERMANENT,
1006 };
1007 
1008 
1009 void __init udpv6_init(void)
1010 {
1011 	if (inet6_add_protocol(&udpv6_protocol, IPPROTO_UDP) < 0)
1012 		printk(KERN_ERR "udpv6_init: Could not register protocol\n");
1013 	inet6_register_protosw(&udpv6_protosw);
1014 }
1015