xref: /linux/net/ipv6/udp.c (revision 606d099cdd1080bbb50ea50dc52d98252f8f10a1)
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/sched.h>
31 #include <linux/net.h>
32 #include <linux/in6.h>
33 #include <linux/netdevice.h>
34 #include <linux/if_arp.h>
35 #include <linux/ipv6.h>
36 #include <linux/icmpv6.h>
37 #include <linux/init.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 DEFINE_SNMP_STAT(struct udp_mib, udp_stats_in6) __read_mostly;
55 
56 static inline int udp_v6_get_port(struct sock *sk, unsigned short snum)
57 {
58 	return udp_get_port(sk, snum, ipv6_rcv_saddr_equal);
59 }
60 
61 static struct sock *__udp6_lib_lookup(struct in6_addr *saddr, __be16 sport,
62 				      struct in6_addr *daddr, __be16 dport,
63 				      int dif, struct hlist_head udptable[])
64 {
65 	struct sock *sk, *result = NULL;
66 	struct hlist_node *node;
67 	unsigned short hnum = ntohs(dport);
68 	int badness = -1;
69 
70  	read_lock(&udp_hash_lock);
71 	sk_for_each(sk, node, &udptable[hnum & (UDP_HTABLE_SIZE - 1)]) {
72 		struct inet_sock *inet = inet_sk(sk);
73 
74 		if (inet->num == hnum && 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 	size_t copied;
125 	int err, copy_only, 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  	copied = skb->len - sizeof(struct udphdr);
139   	if (copied > len) {
140   		copied = len;
141   		msg->msg_flags |= MSG_TRUNC;
142   	}
143 
144 	/*
145 	 * 	Decide whether to checksum and/or copy data.
146 	 */
147 	copy_only = (skb->ip_summed==CHECKSUM_UNNECESSARY);
148 
149 	if (is_udplite  ||  (!copy_only  &&  msg->msg_flags&MSG_TRUNC)) {
150 		if (__udp_lib_checksum_complete(skb))
151 			goto csum_copy_err;
152 		copy_only = 1;
153 	}
154 
155 	if (copy_only)
156 		err = skb_copy_datagram_iovec(skb, sizeof(struct udphdr),
157 					      msg->msg_iov, copied       );
158 	else {
159 		err = skb_copy_and_csum_datagram_iovec(skb, sizeof(struct udphdr), msg->msg_iov);
160 		if (err == -EINVAL)
161 			goto csum_copy_err;
162 	}
163 	if (err)
164 		goto out_free;
165 
166 	sock_recv_timestamp(msg, sk, skb);
167 
168 	/* Copy the address. */
169 	if (msg->msg_name) {
170 		struct sockaddr_in6 *sin6;
171 
172 		sin6 = (struct sockaddr_in6 *) msg->msg_name;
173 		sin6->sin6_family = AF_INET6;
174 		sin6->sin6_port = skb->h.uh->source;
175 		sin6->sin6_flowinfo = 0;
176 		sin6->sin6_scope_id = 0;
177 
178 		if (skb->protocol == htons(ETH_P_IP))
179 			ipv6_addr_set(&sin6->sin6_addr, 0, 0,
180 				      htonl(0xffff), skb->nh.iph->saddr);
181 		else {
182 			ipv6_addr_copy(&sin6->sin6_addr, &skb->nh.ipv6h->saddr);
183 			if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL)
184 				sin6->sin6_scope_id = IP6CB(skb)->iif;
185 		}
186 
187 	}
188 	if (skb->protocol == htons(ETH_P_IP)) {
189 		if (inet->cmsg_flags)
190 			ip_cmsg_recv(msg, skb);
191 	} else {
192 		if (np->rxopt.all)
193 			datagram_recv_ctl(sk, msg, skb);
194   	}
195 
196 	err = copied;
197 	if (flags & MSG_TRUNC)
198 		err = skb->len - sizeof(struct udphdr);
199 
200 out_free:
201 	skb_free_datagram(sk, skb);
202 out:
203 	return err;
204 
205 csum_copy_err:
206 	skb_kill_datagram(sk, skb, flags);
207 
208 	if (flags & MSG_DONTWAIT) {
209 		UDP6_INC_STATS_USER(UDP_MIB_INERRORS, is_udplite);
210 		return -EAGAIN;
211 	}
212 	goto try_again;
213 }
214 
215 void __udp6_lib_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
216 		    int type, int code, int offset, __be32 info,
217 		    struct hlist_head udptable[]                    )
218 {
219 	struct ipv6_pinfo *np;
220 	struct ipv6hdr *hdr = (struct ipv6hdr*)skb->data;
221 	struct in6_addr *saddr = &hdr->saddr;
222 	struct in6_addr *daddr = &hdr->daddr;
223 	struct udphdr *uh = (struct udphdr*)(skb->data+offset);
224 	struct sock *sk;
225 	int err;
226 
227 	sk = __udp6_lib_lookup(daddr, uh->dest,
228 			       saddr, uh->source, inet6_iif(skb), udptable);
229 	if (sk == NULL)
230 		return;
231 
232 	np = inet6_sk(sk);
233 
234 	if (!icmpv6_err_convert(type, code, &err) && !np->recverr)
235 		goto out;
236 
237 	if (sk->sk_state != TCP_ESTABLISHED && !np->recverr)
238 		goto out;
239 
240 	if (np->recverr)
241 		ipv6_icmp_error(sk, skb, err, uh->dest, ntohl(info), (u8 *)(uh+1));
242 
243 	sk->sk_err = err;
244 	sk->sk_error_report(sk);
245 out:
246 	sock_put(sk);
247 }
248 
249 static __inline__ void udpv6_err(struct sk_buff *skb,
250 				 struct inet6_skb_parm *opt, int type,
251 				 int code, int offset, __be32 info     )
252 {
253 	return __udp6_lib_err(skb, opt, type, code, offset, info, udp_hash);
254 }
255 
256 int udpv6_queue_rcv_skb(struct sock * sk, struct sk_buff *skb)
257 {
258 	struct udp_sock *up = udp_sk(sk);
259 	int rc;
260 
261 	if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
262 		goto drop;
263 
264 	/*
265 	 * UDP-Lite specific tests, ignored on UDP sockets (see net/ipv4/udp.c).
266 	 */
267 	if ((up->pcflag & UDPLITE_RECV_CC)  &&  UDP_SKB_CB(skb)->partial_cov) {
268 
269 		if (up->pcrlen == 0) {          /* full coverage was set  */
270 			LIMIT_NETDEBUG(KERN_WARNING "UDPLITE6: partial coverage"
271 				" %d while full coverage %d requested\n",
272 				UDP_SKB_CB(skb)->cscov, skb->len);
273 			goto drop;
274 		}
275 		if (UDP_SKB_CB(skb)->cscov  <  up->pcrlen) {
276 			LIMIT_NETDEBUG(KERN_WARNING "UDPLITE6: coverage %d "
277 						    "too small, need min %d\n",
278 				       UDP_SKB_CB(skb)->cscov, up->pcrlen);
279 			goto drop;
280 		}
281 	}
282 
283 	if (udp_lib_checksum_complete(skb))
284 		goto drop;
285 
286 	if ((rc = sock_queue_rcv_skb(sk,skb)) < 0) {
287 		/* Note that an ENOMEM error is charged twice */
288 		if (rc == -ENOMEM)
289 			UDP6_INC_STATS_BH(UDP_MIB_RCVBUFERRORS, up->pcflag);
290 		goto drop;
291 	}
292 	UDP6_INC_STATS_BH(UDP_MIB_INDATAGRAMS, up->pcflag);
293 	return 0;
294 drop:
295 	UDP6_INC_STATS_BH(UDP_MIB_INERRORS, up->pcflag);
296 	kfree_skb(skb);
297 	return -1;
298 }
299 
300 static struct sock *udp_v6_mcast_next(struct sock *sk,
301 				      __be16 loc_port, struct in6_addr *loc_addr,
302 				      __be16 rmt_port, struct in6_addr *rmt_addr,
303 				      int dif)
304 {
305 	struct hlist_node *node;
306 	struct sock *s = sk;
307 	unsigned short num = ntohs(loc_port);
308 
309 	sk_for_each_from(s, node) {
310 		struct inet_sock *inet = inet_sk(s);
311 
312 		if (inet->num == num && s->sk_family == PF_INET6) {
313 			struct ipv6_pinfo *np = inet6_sk(s);
314 			if (inet->dport) {
315 				if (inet->dport != rmt_port)
316 					continue;
317 			}
318 			if (!ipv6_addr_any(&np->daddr) &&
319 			    !ipv6_addr_equal(&np->daddr, rmt_addr))
320 				continue;
321 
322 			if (s->sk_bound_dev_if && s->sk_bound_dev_if != dif)
323 				continue;
324 
325 			if (!ipv6_addr_any(&np->rcv_saddr)) {
326 				if (!ipv6_addr_equal(&np->rcv_saddr, loc_addr))
327 					continue;
328 			}
329 			if(!inet6_mc_check(s, loc_addr, rmt_addr))
330 				continue;
331 			return s;
332 		}
333 	}
334 	return NULL;
335 }
336 
337 /*
338  * Note: called only from the BH handler context,
339  * so we don't need to lock the hashes.
340  */
341 static int __udp6_lib_mcast_deliver(struct sk_buff *skb, struct in6_addr *saddr,
342 		           struct in6_addr *daddr, struct hlist_head udptable[])
343 {
344 	struct sock *sk, *sk2;
345 	const struct udphdr *uh = skb->h.uh;
346 	int dif;
347 
348 	read_lock(&udp_hash_lock);
349 	sk = sk_head(&udptable[ntohs(uh->dest) & (UDP_HTABLE_SIZE - 1)]);
350 	dif = inet6_iif(skb);
351 	sk = udp_v6_mcast_next(sk, uh->dest, daddr, uh->source, saddr, dif);
352 	if (!sk) {
353 		kfree_skb(skb);
354 		goto out;
355 	}
356 
357 	sk2 = sk;
358 	while ((sk2 = udp_v6_mcast_next(sk_next(sk2), uh->dest, daddr,
359 					uh->source, saddr, dif))) {
360 		struct sk_buff *buff = skb_clone(skb, GFP_ATOMIC);
361 		if (buff)
362 			udpv6_queue_rcv_skb(sk2, buff);
363 	}
364 	udpv6_queue_rcv_skb(sk, skb);
365 out:
366 	read_unlock(&udp_hash_lock);
367 	return 0;
368 }
369 
370 static inline int udp6_csum_init(struct sk_buff *skb, struct udphdr *uh)
371 
372 {
373 	if (uh->check == 0) {
374 		/* RFC 2460 section 8.1 says that we SHOULD log
375 		   this error. Well, it is reasonable.
376 		 */
377 		LIMIT_NETDEBUG(KERN_INFO "IPv6: udp checksum is 0\n");
378 		return 1;
379 	}
380 	if (skb->ip_summed == CHECKSUM_COMPLETE &&
381 	    !csum_ipv6_magic(&skb->nh.ipv6h->saddr, &skb->nh.ipv6h->daddr,
382 		    	     skb->len, IPPROTO_UDP, skb->csum             ))
383 		skb->ip_summed = CHECKSUM_UNNECESSARY;
384 
385 	if (skb->ip_summed != CHECKSUM_UNNECESSARY)
386 		skb->csum = ~csum_unfold(csum_ipv6_magic(&skb->nh.ipv6h->saddr,
387 							 &skb->nh.ipv6h->daddr,
388 							 skb->len, IPPROTO_UDP,
389 							 0));
390 
391 	return (UDP_SKB_CB(skb)->partial_cov = 0);
392 }
393 
394 int __udp6_lib_rcv(struct sk_buff **pskb, struct hlist_head udptable[],
395 		   int is_udplite)
396 {
397 	struct sk_buff *skb = *pskb;
398 	struct sock *sk;
399   	struct udphdr *uh;
400 	struct net_device *dev = skb->dev;
401 	struct in6_addr *saddr, *daddr;
402 	u32 ulen = 0;
403 
404 	if (!pskb_may_pull(skb, sizeof(struct udphdr)))
405 		goto short_packet;
406 
407 	saddr = &skb->nh.ipv6h->saddr;
408 	daddr = &skb->nh.ipv6h->daddr;
409 	uh = skb->h.uh;
410 
411 	ulen = ntohs(uh->len);
412 	if (ulen > skb->len)
413 		goto short_packet;
414 
415 	if(! is_udplite ) {		/* UDP validates ulen. */
416 
417 		/* Check for jumbo payload */
418 		if (ulen == 0)
419 			ulen = skb->len;
420 
421 		if (ulen < sizeof(*uh))
422 			goto short_packet;
423 
424 		if (ulen < skb->len) {
425 			if (pskb_trim_rcsum(skb, ulen))
426 				goto short_packet;
427 			saddr = &skb->nh.ipv6h->saddr;
428 			daddr = &skb->nh.ipv6h->daddr;
429 			uh = skb->h.uh;
430 		}
431 
432 		if (udp6_csum_init(skb, uh))
433 			goto discard;
434 
435 	} else 	{			/* UDP-Lite validates cscov. */
436 		if (udplite6_csum_init(skb, uh))
437 			goto discard;
438 	}
439 
440 	/*
441 	 *	Multicast receive code
442 	 */
443 	if (ipv6_addr_is_multicast(daddr))
444 		return __udp6_lib_mcast_deliver(skb, saddr, daddr, udptable);
445 
446 	/* Unicast */
447 
448 	/*
449 	 * check socket cache ... must talk to Alan about his plans
450 	 * for sock caches... i'll skip this for now.
451 	 */
452 	sk = __udp6_lib_lookup(saddr, uh->source,
453 			       daddr, uh->dest, inet6_iif(skb), udptable);
454 
455 	if (sk == NULL) {
456 		if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
457 			goto discard;
458 
459 		if (udp_lib_checksum_complete(skb))
460 			goto discard;
461 		UDP6_INC_STATS_BH(UDP_MIB_NOPORTS, is_udplite);
462 
463 		icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0, dev);
464 
465 		kfree_skb(skb);
466 		return(0);
467 	}
468 
469 	/* deliver */
470 
471 	udpv6_queue_rcv_skb(sk, skb);
472 	sock_put(sk);
473 	return(0);
474 
475 short_packet:
476 	LIMIT_NETDEBUG(KERN_DEBUG "UDP%sv6: short packet: %d/%u\n",
477 		       is_udplite? "-Lite" : "",  ulen, skb->len);
478 
479 discard:
480 	UDP6_INC_STATS_BH(UDP_MIB_INERRORS, is_udplite);
481 	kfree_skb(skb);
482 	return(0);
483 }
484 
485 static __inline__ int udpv6_rcv(struct sk_buff **pskb)
486 {
487 	return __udp6_lib_rcv(pskb, udp_hash, 0);
488 }
489 
490 /*
491  * Throw away all pending data and cancel the corking. Socket is locked.
492  */
493 static void udp_v6_flush_pending_frames(struct sock *sk)
494 {
495 	struct udp_sock *up = udp_sk(sk);
496 
497 	if (up->pending) {
498 		up->len = 0;
499 		up->pending = 0;
500 		ip6_flush_pending_frames(sk);
501         }
502 }
503 
504 /*
505  *	Sending
506  */
507 
508 static int udp_v6_push_pending_frames(struct sock *sk)
509 {
510 	struct sk_buff *skb;
511 	struct udphdr *uh;
512 	struct udp_sock  *up = udp_sk(sk);
513 	struct inet_sock *inet = inet_sk(sk);
514 	struct flowi *fl = &inet->cork.fl;
515 	int err = 0;
516 	__wsum csum = 0;
517 
518 	/* Grab the skbuff where UDP header space exists. */
519 	if ((skb = skb_peek(&sk->sk_write_queue)) == NULL)
520 		goto out;
521 
522 	/*
523 	 * Create a UDP header
524 	 */
525 	uh = skb->h.uh;
526 	uh->source = fl->fl_ip_sport;
527 	uh->dest = fl->fl_ip_dport;
528 	uh->len = htons(up->len);
529 	uh->check = 0;
530 
531 	if (up->pcflag)
532 		csum = udplite_csum_outgoing(sk, skb);
533 	 else
534 		csum = udp_csum_outgoing(sk, skb);
535 
536 	/* add protocol-dependent pseudo-header */
537 	uh->check = csum_ipv6_magic(&fl->fl6_src, &fl->fl6_dst,
538 				    up->len, fl->proto, csum   );
539 	if (uh->check == 0)
540 		uh->check = CSUM_MANGLED_0;
541 
542 	err = ip6_push_pending_frames(sk);
543 out:
544 	up->len = 0;
545 	up->pending = 0;
546 	return err;
547 }
548 
549 int udpv6_sendmsg(struct kiocb *iocb, struct sock *sk,
550 		  struct msghdr *msg, size_t len)
551 {
552 	struct ipv6_txoptions opt_space;
553 	struct udp_sock *up = udp_sk(sk);
554 	struct inet_sock *inet = inet_sk(sk);
555 	struct ipv6_pinfo *np = inet6_sk(sk);
556 	struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *) msg->msg_name;
557 	struct in6_addr *daddr, *final_p = NULL, final;
558 	struct ipv6_txoptions *opt = NULL;
559 	struct ip6_flowlabel *flowlabel = NULL;
560 	struct flowi fl;
561 	struct dst_entry *dst;
562 	int addr_len = msg->msg_namelen;
563 	int ulen = len;
564 	int hlimit = -1;
565 	int tclass = -1;
566 	int corkreq = up->corkflag || msg->msg_flags&MSG_MORE;
567 	int err;
568 	int connected = 0;
569 	int is_udplite = up->pcflag;
570 	int (*getfrag)(void *, char *, int, int, int, struct sk_buff *);
571 
572 	/* destination address check */
573 	if (sin6) {
574 		if (addr_len < offsetof(struct sockaddr, sa_data))
575 			return -EINVAL;
576 
577 		switch (sin6->sin6_family) {
578 		case AF_INET6:
579 			if (addr_len < SIN6_LEN_RFC2133)
580 				return -EINVAL;
581 			daddr = &sin6->sin6_addr;
582 			break;
583 		case AF_INET:
584 			goto do_udp_sendmsg;
585 		case AF_UNSPEC:
586 			msg->msg_name = sin6 = NULL;
587 			msg->msg_namelen = addr_len = 0;
588 			daddr = NULL;
589 			break;
590 		default:
591 			return -EINVAL;
592 		}
593 	} else if (!up->pending) {
594 		if (sk->sk_state != TCP_ESTABLISHED)
595 			return -EDESTADDRREQ;
596 		daddr = &np->daddr;
597 	} else
598 		daddr = NULL;
599 
600 	if (daddr) {
601 		if (ipv6_addr_type(daddr) == IPV6_ADDR_MAPPED) {
602 			struct sockaddr_in sin;
603 			sin.sin_family = AF_INET;
604 			sin.sin_port = sin6 ? sin6->sin6_port : inet->dport;
605 			sin.sin_addr.s_addr = daddr->s6_addr32[3];
606 			msg->msg_name = &sin;
607 			msg->msg_namelen = sizeof(sin);
608 do_udp_sendmsg:
609 			if (__ipv6_only_sock(sk))
610 				return -ENETUNREACH;
611 			return udp_sendmsg(iocb, sk, msg, len);
612 		}
613 	}
614 
615 	if (up->pending == AF_INET)
616 		return udp_sendmsg(iocb, sk, msg, len);
617 
618 	/* Rough check on arithmetic overflow,
619 	   better check is made in ip6_build_xmit
620 	   */
621 	if (len > INT_MAX - sizeof(struct udphdr))
622 		return -EMSGSIZE;
623 
624 	if (up->pending) {
625 		/*
626 		 * There are pending frames.
627 		 * The socket lock must be held while it's corked.
628 		 */
629 		lock_sock(sk);
630 		if (likely(up->pending)) {
631 			if (unlikely(up->pending != AF_INET6)) {
632 				release_sock(sk);
633 				return -EAFNOSUPPORT;
634 			}
635 			dst = NULL;
636 			goto do_append_data;
637 		}
638 		release_sock(sk);
639 	}
640 	ulen += sizeof(struct udphdr);
641 
642 	memset(&fl, 0, sizeof(fl));
643 
644 	if (sin6) {
645 		if (sin6->sin6_port == 0)
646 			return -EINVAL;
647 
648 		fl.fl_ip_dport = sin6->sin6_port;
649 		daddr = &sin6->sin6_addr;
650 
651 		if (np->sndflow) {
652 			fl.fl6_flowlabel = sin6->sin6_flowinfo&IPV6_FLOWINFO_MASK;
653 			if (fl.fl6_flowlabel&IPV6_FLOWLABEL_MASK) {
654 				flowlabel = fl6_sock_lookup(sk, fl.fl6_flowlabel);
655 				if (flowlabel == NULL)
656 					return -EINVAL;
657 				daddr = &flowlabel->dst;
658 			}
659 		}
660 
661 		/*
662 		 * Otherwise it will be difficult to maintain
663 		 * sk->sk_dst_cache.
664 		 */
665 		if (sk->sk_state == TCP_ESTABLISHED &&
666 		    ipv6_addr_equal(daddr, &np->daddr))
667 			daddr = &np->daddr;
668 
669 		if (addr_len >= sizeof(struct sockaddr_in6) &&
670 		    sin6->sin6_scope_id &&
671 		    ipv6_addr_type(daddr)&IPV6_ADDR_LINKLOCAL)
672 			fl.oif = sin6->sin6_scope_id;
673 	} else {
674 		if (sk->sk_state != TCP_ESTABLISHED)
675 			return -EDESTADDRREQ;
676 
677 		fl.fl_ip_dport = inet->dport;
678 		daddr = &np->daddr;
679 		fl.fl6_flowlabel = np->flow_label;
680 		connected = 1;
681 	}
682 
683 	if (!fl.oif)
684 		fl.oif = sk->sk_bound_dev_if;
685 
686 	if (msg->msg_controllen) {
687 		opt = &opt_space;
688 		memset(opt, 0, sizeof(struct ipv6_txoptions));
689 		opt->tot_len = sizeof(*opt);
690 
691 		err = datagram_send_ctl(msg, &fl, opt, &hlimit, &tclass);
692 		if (err < 0) {
693 			fl6_sock_release(flowlabel);
694 			return err;
695 		}
696 		if ((fl.fl6_flowlabel&IPV6_FLOWLABEL_MASK) && !flowlabel) {
697 			flowlabel = fl6_sock_lookup(sk, fl.fl6_flowlabel);
698 			if (flowlabel == NULL)
699 				return -EINVAL;
700 		}
701 		if (!(opt->opt_nflen|opt->opt_flen))
702 			opt = NULL;
703 		connected = 0;
704 	}
705 	if (opt == NULL)
706 		opt = np->opt;
707 	if (flowlabel)
708 		opt = fl6_merge_options(&opt_space, flowlabel, opt);
709 	opt = ipv6_fixup_options(&opt_space, opt);
710 
711 	fl.proto = sk->sk_protocol;
712 	ipv6_addr_copy(&fl.fl6_dst, daddr);
713 	if (ipv6_addr_any(&fl.fl6_src) && !ipv6_addr_any(&np->saddr))
714 		ipv6_addr_copy(&fl.fl6_src, &np->saddr);
715 	fl.fl_ip_sport = inet->sport;
716 
717 	/* merge ip6_build_xmit from ip6_output */
718 	if (opt && opt->srcrt) {
719 		struct rt0_hdr *rt0 = (struct rt0_hdr *) opt->srcrt;
720 		ipv6_addr_copy(&final, &fl.fl6_dst);
721 		ipv6_addr_copy(&fl.fl6_dst, rt0->addr);
722 		final_p = &final;
723 		connected = 0;
724 	}
725 
726 	if (!fl.oif && ipv6_addr_is_multicast(&fl.fl6_dst)) {
727 		fl.oif = np->mcast_oif;
728 		connected = 0;
729 	}
730 
731 	security_sk_classify_flow(sk, &fl);
732 
733 	err = ip6_sk_dst_lookup(sk, &dst, &fl);
734 	if (err)
735 		goto out;
736 	if (final_p)
737 		ipv6_addr_copy(&fl.fl6_dst, final_p);
738 
739 	if ((err = xfrm_lookup(&dst, &fl, sk, 0)) < 0)
740 		goto out;
741 
742 	if (hlimit < 0) {
743 		if (ipv6_addr_is_multicast(&fl.fl6_dst))
744 			hlimit = np->mcast_hops;
745 		else
746 			hlimit = np->hop_limit;
747 		if (hlimit < 0)
748 			hlimit = dst_metric(dst, RTAX_HOPLIMIT);
749 		if (hlimit < 0)
750 			hlimit = ipv6_get_hoplimit(dst->dev);
751 	}
752 
753 	if (tclass < 0) {
754 		tclass = np->tclass;
755 		if (tclass < 0)
756 			tclass = 0;
757 	}
758 
759 	if (msg->msg_flags&MSG_CONFIRM)
760 		goto do_confirm;
761 back_from_confirm:
762 
763 	lock_sock(sk);
764 	if (unlikely(up->pending)) {
765 		/* The socket is already corked while preparing it. */
766 		/* ... which is an evident application bug. --ANK */
767 		release_sock(sk);
768 
769 		LIMIT_NETDEBUG(KERN_DEBUG "udp cork app bug 2\n");
770 		err = -EINVAL;
771 		goto out;
772 	}
773 
774 	up->pending = AF_INET6;
775 
776 do_append_data:
777 	up->len += ulen;
778 	getfrag  =  is_udplite ?  udplite_getfrag : ip_generic_getfrag;
779 	err = ip6_append_data(sk, getfrag, msg->msg_iov, ulen,
780 		sizeof(struct udphdr), hlimit, tclass, opt, &fl,
781 		(struct rt6_info*)dst,
782 		corkreq ? msg->msg_flags|MSG_MORE : msg->msg_flags);
783 	if (err)
784 		udp_v6_flush_pending_frames(sk);
785 	else if (!corkreq)
786 		err = udp_v6_push_pending_frames(sk);
787 	else if (unlikely(skb_queue_empty(&sk->sk_write_queue)))
788 		up->pending = 0;
789 
790 	if (dst) {
791 		if (connected) {
792 			ip6_dst_store(sk, dst,
793 				      ipv6_addr_equal(&fl.fl6_dst, &np->daddr) ?
794 				      &np->daddr : NULL,
795 #ifdef CONFIG_IPV6_SUBTREES
796 				      ipv6_addr_equal(&fl.fl6_src, &np->saddr) ?
797 				      &np->saddr :
798 #endif
799 				      NULL);
800 		} else {
801 			dst_release(dst);
802 		}
803 	}
804 
805 	if (err > 0)
806 		err = np->recverr ? net_xmit_errno(err) : 0;
807 	release_sock(sk);
808 out:
809 	fl6_sock_release(flowlabel);
810 	if (!err) {
811 		UDP6_INC_STATS_USER(UDP_MIB_OUTDATAGRAMS, is_udplite);
812 		return len;
813 	}
814 	/*
815 	 * ENOBUFS = no kernel mem, SOCK_NOSPACE = no sndbuf space.  Reporting
816 	 * ENOBUFS might not be good (it's not tunable per se), but otherwise
817 	 * we don't have a good statistic (IpOutDiscards but it can be too many
818 	 * things).  We could add another new stat but at least for now that
819 	 * seems like overkill.
820 	 */
821 	if (err == -ENOBUFS || test_bit(SOCK_NOSPACE, &sk->sk_socket->flags)) {
822 		UDP6_INC_STATS_USER(UDP_MIB_SNDBUFERRORS, is_udplite);
823 	}
824 	return err;
825 
826 do_confirm:
827 	dst_confirm(dst);
828 	if (!(msg->msg_flags&MSG_PROBE) || len)
829 		goto back_from_confirm;
830 	err = 0;
831 	goto out;
832 }
833 
834 int udpv6_destroy_sock(struct sock *sk)
835 {
836 	lock_sock(sk);
837 	udp_v6_flush_pending_frames(sk);
838 	release_sock(sk);
839 
840 	inet6_destroy_sock(sk);
841 
842 	return 0;
843 }
844 
845 /*
846  *	Socket option code for UDP
847  */
848 int udpv6_setsockopt(struct sock *sk, int level, int optname,
849 		     char __user *optval, int optlen)
850 {
851 	if (level == SOL_UDP  ||  level == SOL_UDPLITE)
852 		return udp_lib_setsockopt(sk, level, optname, optval, optlen,
853 					  udp_v6_push_pending_frames);
854 	return ipv6_setsockopt(sk, level, optname, optval, optlen);
855 }
856 
857 #ifdef CONFIG_COMPAT
858 int compat_udpv6_setsockopt(struct sock *sk, int level, int optname,
859 			    char __user *optval, int optlen)
860 {
861 	if (level == SOL_UDP  ||  level == SOL_UDPLITE)
862 		return udp_lib_setsockopt(sk, level, optname, optval, optlen,
863 					  udp_v6_push_pending_frames);
864 	return compat_ipv6_setsockopt(sk, level, optname, optval, optlen);
865 }
866 #endif
867 
868 int udpv6_getsockopt(struct sock *sk, int level, int optname,
869 		     char __user *optval, int __user *optlen)
870 {
871 	if (level == SOL_UDP  ||  level == SOL_UDPLITE)
872 		return udp_lib_getsockopt(sk, level, optname, optval, optlen);
873 	return ipv6_getsockopt(sk, level, optname, optval, optlen);
874 }
875 
876 #ifdef CONFIG_COMPAT
877 int compat_udpv6_getsockopt(struct sock *sk, int level, int optname,
878 			    char __user *optval, int __user *optlen)
879 {
880 	if (level == SOL_UDP  ||  level == SOL_UDPLITE)
881 		return udp_lib_getsockopt(sk, level, optname, optval, optlen);
882 	return compat_ipv6_getsockopt(sk, level, optname, optval, optlen);
883 }
884 #endif
885 
886 static struct inet6_protocol udpv6_protocol = {
887 	.handler	=	udpv6_rcv,
888 	.err_handler	=	udpv6_err,
889 	.flags		=	INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
890 };
891 
892 /* ------------------------------------------------------------------------ */
893 #ifdef CONFIG_PROC_FS
894 
895 static void udp6_sock_seq_show(struct seq_file *seq, struct sock *sp, int bucket)
896 {
897 	struct inet_sock *inet = inet_sk(sp);
898 	struct ipv6_pinfo *np = inet6_sk(sp);
899 	struct in6_addr *dest, *src;
900 	__u16 destp, srcp;
901 
902 	dest  = &np->daddr;
903 	src   = &np->rcv_saddr;
904 	destp = ntohs(inet->dport);
905 	srcp  = ntohs(inet->sport);
906 	seq_printf(seq,
907 		   "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
908 		   "%02X %08X:%08X %02X:%08lX %08X %5d %8d %lu %d %p\n",
909 		   bucket,
910 		   src->s6_addr32[0], src->s6_addr32[1],
911 		   src->s6_addr32[2], src->s6_addr32[3], srcp,
912 		   dest->s6_addr32[0], dest->s6_addr32[1],
913 		   dest->s6_addr32[2], dest->s6_addr32[3], destp,
914 		   sp->sk_state,
915 		   atomic_read(&sp->sk_wmem_alloc),
916 		   atomic_read(&sp->sk_rmem_alloc),
917 		   0, 0L, 0,
918 		   sock_i_uid(sp), 0,
919 		   sock_i_ino(sp),
920 		   atomic_read(&sp->sk_refcnt), sp);
921 }
922 
923 int udp6_seq_show(struct seq_file *seq, void *v)
924 {
925 	if (v == SEQ_START_TOKEN)
926 		seq_printf(seq,
927 			   "  sl  "
928 			   "local_address                         "
929 			   "remote_address                        "
930 			   "st tx_queue rx_queue tr tm->when retrnsmt"
931 			   "   uid  timeout inode\n");
932 	else
933 		udp6_sock_seq_show(seq, v, ((struct udp_iter_state *)seq->private)->bucket);
934 	return 0;
935 }
936 
937 static struct file_operations udp6_seq_fops;
938 static struct udp_seq_afinfo udp6_seq_afinfo = {
939 	.owner		= THIS_MODULE,
940 	.name		= "udp6",
941 	.family		= AF_INET6,
942 	.hashtable	= udp_hash,
943 	.seq_show	= udp6_seq_show,
944 	.seq_fops	= &udp6_seq_fops,
945 };
946 
947 int __init udp6_proc_init(void)
948 {
949 	return udp_proc_register(&udp6_seq_afinfo);
950 }
951 
952 void udp6_proc_exit(void) {
953 	udp_proc_unregister(&udp6_seq_afinfo);
954 }
955 #endif /* CONFIG_PROC_FS */
956 
957 /* ------------------------------------------------------------------------ */
958 
959 struct proto udpv6_prot = {
960 	.name		   = "UDPv6",
961 	.owner		   = THIS_MODULE,
962 	.close		   = udp_lib_close,
963 	.connect	   = ip6_datagram_connect,
964 	.disconnect	   = udp_disconnect,
965 	.ioctl		   = udp_ioctl,
966 	.destroy	   = udpv6_destroy_sock,
967 	.setsockopt	   = udpv6_setsockopt,
968 	.getsockopt	   = udpv6_getsockopt,
969 	.sendmsg	   = udpv6_sendmsg,
970 	.recvmsg	   = udpv6_recvmsg,
971 	.backlog_rcv	   = udpv6_queue_rcv_skb,
972 	.hash		   = udp_lib_hash,
973 	.unhash		   = udp_lib_unhash,
974 	.get_port	   = udp_v6_get_port,
975 	.obj_size	   = sizeof(struct udp6_sock),
976 #ifdef CONFIG_COMPAT
977 	.compat_setsockopt = compat_udpv6_setsockopt,
978 	.compat_getsockopt = compat_udpv6_getsockopt,
979 #endif
980 };
981 
982 static struct inet_protosw udpv6_protosw = {
983 	.type =      SOCK_DGRAM,
984 	.protocol =  IPPROTO_UDP,
985 	.prot =      &udpv6_prot,
986 	.ops =       &inet6_dgram_ops,
987 	.capability =-1,
988 	.no_check =  UDP_CSUM_DEFAULT,
989 	.flags =     INET_PROTOSW_PERMANENT,
990 };
991 
992 
993 void __init udpv6_init(void)
994 {
995 	if (inet6_add_protocol(&udpv6_protocol, IPPROTO_UDP) < 0)
996 		printk(KERN_ERR "udpv6_init: Could not register protocol\n");
997 	inet6_register_protosw(&udpv6_protosw);
998 }
999