xref: /openbmc/linux/net/ipv6/udp.c (revision 87c2ce3b)
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/config.h>
27 #include <linux/errno.h>
28 #include <linux/types.h>
29 #include <linux/socket.h>
30 #include <linux/sockios.h>
31 #include <linux/sched.h>
32 #include <linux/net.h>
33 #include <linux/in6.h>
34 #include <linux/netdevice.h>
35 #include <linux/if_arp.h>
36 #include <linux/ipv6.h>
37 #include <linux/icmpv6.h>
38 #include <linux/init.h>
39 #include <linux/skbuff.h>
40 #include <asm/uaccess.h>
41 
42 #include <net/sock.h>
43 #include <net/snmp.h>
44 
45 #include <net/ipv6.h>
46 #include <net/ndisc.h>
47 #include <net/protocol.h>
48 #include <net/transp_v6.h>
49 #include <net/ip6_route.h>
50 #include <net/addrconf.h>
51 #include <net/ip.h>
52 #include <net/udp.h>
53 #include <net/raw.h>
54 #include <net/inet_common.h>
55 #include <net/tcp_states.h>
56 
57 #include <net/ip6_checksum.h>
58 #include <net/xfrm.h>
59 
60 #include <linux/proc_fs.h>
61 #include <linux/seq_file.h>
62 
63 DEFINE_SNMP_STAT(struct udp_mib, udp_stats_in6) __read_mostly;
64 
65 /* Grrr, addr_type already calculated by caller, but I don't want
66  * to add some silly "cookie" argument to this method just for that.
67  */
68 static int udp_v6_get_port(struct sock *sk, unsigned short snum)
69 {
70 	struct sock *sk2;
71 	struct hlist_node *node;
72 
73 	write_lock_bh(&udp_hash_lock);
74 	if (snum == 0) {
75 		int best_size_so_far, best, result, i;
76 
77 		if (udp_port_rover > sysctl_local_port_range[1] ||
78 		    udp_port_rover < sysctl_local_port_range[0])
79 			udp_port_rover = sysctl_local_port_range[0];
80 		best_size_so_far = 32767;
81 		best = result = udp_port_rover;
82 		for (i = 0; i < UDP_HTABLE_SIZE; i++, result++) {
83 			int size;
84 			struct hlist_head *list;
85 
86 			list = &udp_hash[result & (UDP_HTABLE_SIZE - 1)];
87 			if (hlist_empty(list)) {
88 				if (result > sysctl_local_port_range[1])
89 					result = sysctl_local_port_range[0] +
90 						((result - sysctl_local_port_range[0]) &
91 						 (UDP_HTABLE_SIZE - 1));
92 				goto gotit;
93 			}
94 			size = 0;
95 			sk_for_each(sk2, node, list)
96 				if (++size >= best_size_so_far)
97 					goto next;
98 			best_size_so_far = size;
99 			best = result;
100 		next:;
101 		}
102 		result = best;
103 		for(i = 0; i < (1 << 16) / UDP_HTABLE_SIZE; i++, result += UDP_HTABLE_SIZE) {
104 			if (result > sysctl_local_port_range[1])
105 				result = sysctl_local_port_range[0]
106 					+ ((result - sysctl_local_port_range[0]) &
107 					   (UDP_HTABLE_SIZE - 1));
108 			if (!udp_lport_inuse(result))
109 				break;
110 		}
111 		if (i >= (1 << 16) / UDP_HTABLE_SIZE)
112 			goto fail;
113 gotit:
114 		udp_port_rover = snum = result;
115 	} else {
116 		sk_for_each(sk2, node,
117 			    &udp_hash[snum & (UDP_HTABLE_SIZE - 1)]) {
118 			if (inet_sk(sk2)->num == snum &&
119 			    sk2 != sk &&
120 			    (!sk2->sk_bound_dev_if ||
121 			     !sk->sk_bound_dev_if ||
122 			     sk2->sk_bound_dev_if == sk->sk_bound_dev_if) &&
123 			    (!sk2->sk_reuse || !sk->sk_reuse) &&
124 			    ipv6_rcv_saddr_equal(sk, sk2))
125 				goto fail;
126 		}
127 	}
128 
129 	inet_sk(sk)->num = snum;
130 	if (sk_unhashed(sk)) {
131 		sk_add_node(sk, &udp_hash[snum & (UDP_HTABLE_SIZE - 1)]);
132 		sock_prot_inc_use(sk->sk_prot);
133 	}
134 	write_unlock_bh(&udp_hash_lock);
135 	return 0;
136 
137 fail:
138 	write_unlock_bh(&udp_hash_lock);
139 	return 1;
140 }
141 
142 static void udp_v6_hash(struct sock *sk)
143 {
144 	BUG();
145 }
146 
147 static void udp_v6_unhash(struct sock *sk)
148 {
149  	write_lock_bh(&udp_hash_lock);
150 	if (sk_del_node_init(sk)) {
151 		inet_sk(sk)->num = 0;
152 		sock_prot_dec_use(sk->sk_prot);
153 	}
154 	write_unlock_bh(&udp_hash_lock);
155 }
156 
157 static struct sock *udp_v6_lookup(struct in6_addr *saddr, u16 sport,
158 				  struct in6_addr *daddr, u16 dport, int dif)
159 {
160 	struct sock *sk, *result = NULL;
161 	struct hlist_node *node;
162 	unsigned short hnum = ntohs(dport);
163 	int badness = -1;
164 
165  	read_lock(&udp_hash_lock);
166 	sk_for_each(sk, node, &udp_hash[hnum & (UDP_HTABLE_SIZE - 1)]) {
167 		struct inet_sock *inet = inet_sk(sk);
168 
169 		if (inet->num == hnum && sk->sk_family == PF_INET6) {
170 			struct ipv6_pinfo *np = inet6_sk(sk);
171 			int score = 0;
172 			if (inet->dport) {
173 				if (inet->dport != sport)
174 					continue;
175 				score++;
176 			}
177 			if (!ipv6_addr_any(&np->rcv_saddr)) {
178 				if (!ipv6_addr_equal(&np->rcv_saddr, daddr))
179 					continue;
180 				score++;
181 			}
182 			if (!ipv6_addr_any(&np->daddr)) {
183 				if (!ipv6_addr_equal(&np->daddr, saddr))
184 					continue;
185 				score++;
186 			}
187 			if (sk->sk_bound_dev_if) {
188 				if (sk->sk_bound_dev_if != dif)
189 					continue;
190 				score++;
191 			}
192 			if(score == 4) {
193 				result = sk;
194 				break;
195 			} else if(score > badness) {
196 				result = sk;
197 				badness = score;
198 			}
199 		}
200 	}
201 	if (result)
202 		sock_hold(result);
203  	read_unlock(&udp_hash_lock);
204 	return result;
205 }
206 
207 /*
208  *
209  */
210 
211 static void udpv6_close(struct sock *sk, long timeout)
212 {
213 	sk_common_release(sk);
214 }
215 
216 /*
217  * 	This should be easy, if there is something there we
218  * 	return it, otherwise we block.
219  */
220 
221 static int udpv6_recvmsg(struct kiocb *iocb, struct sock *sk,
222 		  struct msghdr *msg, size_t len,
223 		  int noblock, int flags, int *addr_len)
224 {
225 	struct ipv6_pinfo *np = inet6_sk(sk);
226 	struct inet_sock *inet = inet_sk(sk);
227   	struct sk_buff *skb;
228 	size_t copied;
229   	int err;
230 
231   	if (addr_len)
232   		*addr_len=sizeof(struct sockaddr_in6);
233 
234 	if (flags & MSG_ERRQUEUE)
235 		return ipv6_recv_error(sk, msg, len);
236 
237 try_again:
238 	skb = skb_recv_datagram(sk, flags, noblock, &err);
239 	if (!skb)
240 		goto out;
241 
242  	copied = skb->len - sizeof(struct udphdr);
243   	if (copied > len) {
244   		copied = len;
245   		msg->msg_flags |= MSG_TRUNC;
246   	}
247 
248 	if (skb->ip_summed==CHECKSUM_UNNECESSARY) {
249 		err = skb_copy_datagram_iovec(skb, sizeof(struct udphdr), msg->msg_iov,
250 					      copied);
251 	} else if (msg->msg_flags&MSG_TRUNC) {
252 		if (__skb_checksum_complete(skb))
253 			goto csum_copy_err;
254 		err = skb_copy_datagram_iovec(skb, sizeof(struct udphdr), msg->msg_iov,
255 					      copied);
256 	} else {
257 		err = skb_copy_and_csum_datagram_iovec(skb, sizeof(struct udphdr), msg->msg_iov);
258 		if (err == -EINVAL)
259 			goto csum_copy_err;
260 	}
261 	if (err)
262 		goto out_free;
263 
264 	sock_recv_timestamp(msg, sk, skb);
265 
266 	/* Copy the address. */
267 	if (msg->msg_name) {
268 		struct sockaddr_in6 *sin6;
269 
270 		sin6 = (struct sockaddr_in6 *) msg->msg_name;
271 		sin6->sin6_family = AF_INET6;
272 		sin6->sin6_port = skb->h.uh->source;
273 		sin6->sin6_flowinfo = 0;
274 		sin6->sin6_scope_id = 0;
275 
276 		if (skb->protocol == htons(ETH_P_IP))
277 			ipv6_addr_set(&sin6->sin6_addr, 0, 0,
278 				      htonl(0xffff), skb->nh.iph->saddr);
279 		else {
280 			ipv6_addr_copy(&sin6->sin6_addr, &skb->nh.ipv6h->saddr);
281 			if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL)
282 				sin6->sin6_scope_id = IP6CB(skb)->iif;
283 		}
284 
285 	}
286 	if (skb->protocol == htons(ETH_P_IP)) {
287 		if (inet->cmsg_flags)
288 			ip_cmsg_recv(msg, skb);
289 	} else {
290 		if (np->rxopt.all)
291 			datagram_recv_ctl(sk, msg, skb);
292   	}
293 
294 	err = copied;
295 	if (flags & MSG_TRUNC)
296 		err = skb->len - sizeof(struct udphdr);
297 
298 out_free:
299 	skb_free_datagram(sk, skb);
300 out:
301 	return err;
302 
303 csum_copy_err:
304 	skb_kill_datagram(sk, skb, flags);
305 
306 	if (flags & MSG_DONTWAIT) {
307 		UDP6_INC_STATS_USER(UDP_MIB_INERRORS);
308 		return -EAGAIN;
309 	}
310 	goto try_again;
311 }
312 
313 static void udpv6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
314 	       int type, int code, int offset, __u32 info)
315 {
316 	struct ipv6_pinfo *np;
317 	struct ipv6hdr *hdr = (struct ipv6hdr*)skb->data;
318 	struct net_device *dev = skb->dev;
319 	struct in6_addr *saddr = &hdr->saddr;
320 	struct in6_addr *daddr = &hdr->daddr;
321 	struct udphdr *uh = (struct udphdr*)(skb->data+offset);
322 	struct sock *sk;
323 	int err;
324 
325 	sk = udp_v6_lookup(daddr, uh->dest, saddr, uh->source, dev->ifindex);
326 
327 	if (sk == NULL)
328 		return;
329 
330 	np = inet6_sk(sk);
331 
332 	if (!icmpv6_err_convert(type, code, &err) && !np->recverr)
333 		goto out;
334 
335 	if (sk->sk_state != TCP_ESTABLISHED && !np->recverr)
336 		goto out;
337 
338 	if (np->recverr)
339 		ipv6_icmp_error(sk, skb, err, uh->dest, ntohl(info), (u8 *)(uh+1));
340 
341 	sk->sk_err = err;
342 	sk->sk_error_report(sk);
343 out:
344 	sock_put(sk);
345 }
346 
347 static inline int udpv6_queue_rcv_skb(struct sock * sk, struct sk_buff *skb)
348 {
349 	if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb)) {
350 		kfree_skb(skb);
351 		return -1;
352 	}
353 
354 	if (skb_checksum_complete(skb)) {
355 		UDP6_INC_STATS_BH(UDP_MIB_INERRORS);
356 		kfree_skb(skb);
357 		return 0;
358 	}
359 
360 	if (sock_queue_rcv_skb(sk,skb)<0) {
361 		UDP6_INC_STATS_BH(UDP_MIB_INERRORS);
362 		kfree_skb(skb);
363 		return 0;
364 	}
365 	UDP6_INC_STATS_BH(UDP_MIB_INDATAGRAMS);
366 	return 0;
367 }
368 
369 static struct sock *udp_v6_mcast_next(struct sock *sk,
370 				      u16 loc_port, struct in6_addr *loc_addr,
371 				      u16 rmt_port, struct in6_addr *rmt_addr,
372 				      int dif)
373 {
374 	struct hlist_node *node;
375 	struct sock *s = sk;
376 	unsigned short num = ntohs(loc_port);
377 
378 	sk_for_each_from(s, node) {
379 		struct inet_sock *inet = inet_sk(s);
380 
381 		if (inet->num == num && s->sk_family == PF_INET6) {
382 			struct ipv6_pinfo *np = inet6_sk(s);
383 			if (inet->dport) {
384 				if (inet->dport != rmt_port)
385 					continue;
386 			}
387 			if (!ipv6_addr_any(&np->daddr) &&
388 			    !ipv6_addr_equal(&np->daddr, rmt_addr))
389 				continue;
390 
391 			if (s->sk_bound_dev_if && s->sk_bound_dev_if != dif)
392 				continue;
393 
394 			if (!ipv6_addr_any(&np->rcv_saddr)) {
395 				if (!ipv6_addr_equal(&np->rcv_saddr, loc_addr))
396 					continue;
397 			}
398 			if(!inet6_mc_check(s, loc_addr, rmt_addr))
399 				continue;
400 			return s;
401 		}
402 	}
403 	return NULL;
404 }
405 
406 /*
407  * Note: called only from the BH handler context,
408  * so we don't need to lock the hashes.
409  */
410 static void udpv6_mcast_deliver(struct udphdr *uh,
411 				struct in6_addr *saddr, struct in6_addr *daddr,
412 				struct sk_buff *skb)
413 {
414 	struct sock *sk, *sk2;
415 	int dif;
416 
417 	read_lock(&udp_hash_lock);
418 	sk = sk_head(&udp_hash[ntohs(uh->dest) & (UDP_HTABLE_SIZE - 1)]);
419 	dif = skb->dev->ifindex;
420 	sk = udp_v6_mcast_next(sk, uh->dest, daddr, uh->source, saddr, dif);
421 	if (!sk) {
422 		kfree_skb(skb);
423 		goto out;
424 	}
425 
426 	sk2 = sk;
427 	while ((sk2 = udp_v6_mcast_next(sk_next(sk2), uh->dest, daddr,
428 					uh->source, saddr, dif))) {
429 		struct sk_buff *buff = skb_clone(skb, GFP_ATOMIC);
430 		if (buff)
431 			udpv6_queue_rcv_skb(sk2, buff);
432 	}
433 	udpv6_queue_rcv_skb(sk, skb);
434 out:
435 	read_unlock(&udp_hash_lock);
436 }
437 
438 static int udpv6_rcv(struct sk_buff **pskb)
439 {
440 	struct sk_buff *skb = *pskb;
441 	struct sock *sk;
442   	struct udphdr *uh;
443 	struct net_device *dev = skb->dev;
444 	struct in6_addr *saddr, *daddr;
445 	u32 ulen = 0;
446 
447 	if (!pskb_may_pull(skb, sizeof(struct udphdr)))
448 		goto short_packet;
449 
450 	saddr = &skb->nh.ipv6h->saddr;
451 	daddr = &skb->nh.ipv6h->daddr;
452 	uh = skb->h.uh;
453 
454 	ulen = ntohs(uh->len);
455 
456 	/* Check for jumbo payload */
457 	if (ulen == 0)
458 		ulen = skb->len;
459 
460 	if (ulen > skb->len || ulen < sizeof(*uh))
461 		goto short_packet;
462 
463 	if (uh->check == 0) {
464 		/* RFC 2460 section 8.1 says that we SHOULD log
465 		   this error. Well, it is reasonable.
466 		 */
467 		LIMIT_NETDEBUG(KERN_INFO "IPv6: udp checksum is 0\n");
468 		goto discard;
469 	}
470 
471 	if (ulen < skb->len) {
472 		if (pskb_trim_rcsum(skb, ulen))
473 			goto discard;
474 		saddr = &skb->nh.ipv6h->saddr;
475 		daddr = &skb->nh.ipv6h->daddr;
476 		uh = skb->h.uh;
477 	}
478 
479 	if (skb->ip_summed == CHECKSUM_HW &&
480 	    !csum_ipv6_magic(saddr, daddr, ulen, IPPROTO_UDP, skb->csum))
481 		skb->ip_summed = CHECKSUM_UNNECESSARY;
482 
483 	if (skb->ip_summed != CHECKSUM_UNNECESSARY)
484 		skb->csum = ~csum_ipv6_magic(saddr, daddr, ulen, IPPROTO_UDP, 0);
485 
486 	/*
487 	 *	Multicast receive code
488 	 */
489 	if (ipv6_addr_is_multicast(daddr)) {
490 		udpv6_mcast_deliver(uh, saddr, daddr, skb);
491 		return 0;
492 	}
493 
494 	/* Unicast */
495 
496 	/*
497 	 * check socket cache ... must talk to Alan about his plans
498 	 * for sock caches... i'll skip this for now.
499 	 */
500 	sk = udp_v6_lookup(saddr, uh->source, daddr, uh->dest, dev->ifindex);
501 
502 	if (sk == NULL) {
503 		if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
504 			goto discard;
505 
506 		if (skb_checksum_complete(skb))
507 			goto discard;
508 		UDP6_INC_STATS_BH(UDP_MIB_NOPORTS);
509 
510 		icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0, dev);
511 
512 		kfree_skb(skb);
513 		return(0);
514 	}
515 
516 	/* deliver */
517 
518 	udpv6_queue_rcv_skb(sk, skb);
519 	sock_put(sk);
520 	return(0);
521 
522 short_packet:
523 	if (net_ratelimit())
524 		printk(KERN_DEBUG "UDP: short packet: %d/%u\n", ulen, skb->len);
525 
526 discard:
527 	UDP6_INC_STATS_BH(UDP_MIB_INERRORS);
528 	kfree_skb(skb);
529 	return(0);
530 }
531 /*
532  * Throw away all pending data and cancel the corking. Socket is locked.
533  */
534 static void udp_v6_flush_pending_frames(struct sock *sk)
535 {
536 	struct udp_sock *up = udp_sk(sk);
537 
538 	if (up->pending) {
539 		up->len = 0;
540 		up->pending = 0;
541 		ip6_flush_pending_frames(sk);
542         }
543 }
544 
545 /*
546  *	Sending
547  */
548 
549 static int udp_v6_push_pending_frames(struct sock *sk, struct udp_sock *up)
550 {
551 	struct sk_buff *skb;
552 	struct udphdr *uh;
553 	struct inet_sock *inet = inet_sk(sk);
554 	struct flowi *fl = &inet->cork.fl;
555 	int err = 0;
556 
557 	/* Grab the skbuff where UDP header space exists. */
558 	if ((skb = skb_peek(&sk->sk_write_queue)) == NULL)
559 		goto out;
560 
561 	/*
562 	 * Create a UDP header
563 	 */
564 	uh = skb->h.uh;
565 	uh->source = fl->fl_ip_sport;
566 	uh->dest = fl->fl_ip_dport;
567 	uh->len = htons(up->len);
568 	uh->check = 0;
569 
570 	if (sk->sk_no_check == UDP_CSUM_NOXMIT) {
571 		skb->ip_summed = CHECKSUM_NONE;
572 		goto send;
573 	}
574 
575 	if (skb_queue_len(&sk->sk_write_queue) == 1) {
576 		skb->csum = csum_partial((char *)uh,
577 				sizeof(struct udphdr), skb->csum);
578 		uh->check = csum_ipv6_magic(&fl->fl6_src,
579 					    &fl->fl6_dst,
580 					    up->len, fl->proto, skb->csum);
581 	} else {
582 		u32 tmp_csum = 0;
583 
584 		skb_queue_walk(&sk->sk_write_queue, skb) {
585 			tmp_csum = csum_add(tmp_csum, skb->csum);
586 		}
587 		tmp_csum = csum_partial((char *)uh,
588 				sizeof(struct udphdr), tmp_csum);
589                 tmp_csum = csum_ipv6_magic(&fl->fl6_src,
590 					   &fl->fl6_dst,
591 					   up->len, fl->proto, tmp_csum);
592                 uh->check = tmp_csum;
593 
594 	}
595 	if (uh->check == 0)
596 		uh->check = -1;
597 
598 send:
599 	err = ip6_push_pending_frames(sk);
600 out:
601 	up->len = 0;
602 	up->pending = 0;
603 	return err;
604 }
605 
606 static int udpv6_sendmsg(struct kiocb *iocb, struct sock *sk,
607 		  struct msghdr *msg, size_t len)
608 {
609 	struct ipv6_txoptions opt_space;
610 	struct udp_sock *up = udp_sk(sk);
611 	struct inet_sock *inet = inet_sk(sk);
612 	struct ipv6_pinfo *np = inet6_sk(sk);
613 	struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *) msg->msg_name;
614 	struct in6_addr *daddr, *final_p = NULL, final;
615 	struct ipv6_txoptions *opt = NULL;
616 	struct ip6_flowlabel *flowlabel = NULL;
617 	struct flowi *fl = &inet->cork.fl;
618 	struct dst_entry *dst;
619 	int addr_len = msg->msg_namelen;
620 	int ulen = len;
621 	int hlimit = -1;
622 	int tclass = -1;
623 	int corkreq = up->corkflag || msg->msg_flags&MSG_MORE;
624 	int err;
625 	int connected = 0;
626 
627 	/* destination address check */
628 	if (sin6) {
629 		if (addr_len < offsetof(struct sockaddr, sa_data))
630 			return -EINVAL;
631 
632 		switch (sin6->sin6_family) {
633 		case AF_INET6:
634 			if (addr_len < SIN6_LEN_RFC2133)
635 				return -EINVAL;
636 			daddr = &sin6->sin6_addr;
637 			break;
638 		case AF_INET:
639 			goto do_udp_sendmsg;
640 		case AF_UNSPEC:
641 			msg->msg_name = sin6 = NULL;
642 			msg->msg_namelen = addr_len = 0;
643 			daddr = NULL;
644 			break;
645 		default:
646 			return -EINVAL;
647 		}
648 	} else if (!up->pending) {
649 		if (sk->sk_state != TCP_ESTABLISHED)
650 			return -EDESTADDRREQ;
651 		daddr = &np->daddr;
652 	} else
653 		daddr = NULL;
654 
655 	if (daddr) {
656 		if (ipv6_addr_type(daddr) == IPV6_ADDR_MAPPED) {
657 			struct sockaddr_in sin;
658 			sin.sin_family = AF_INET;
659 			sin.sin_port = sin6 ? sin6->sin6_port : inet->dport;
660 			sin.sin_addr.s_addr = daddr->s6_addr32[3];
661 			msg->msg_name = &sin;
662 			msg->msg_namelen = sizeof(sin);
663 do_udp_sendmsg:
664 			if (__ipv6_only_sock(sk))
665 				return -ENETUNREACH;
666 			return udp_sendmsg(iocb, sk, msg, len);
667 		}
668 	}
669 
670 	if (up->pending == AF_INET)
671 		return udp_sendmsg(iocb, sk, msg, len);
672 
673 	/* Rough check on arithmetic overflow,
674 	   better check is made in ip6_build_xmit
675 	   */
676 	if (len > INT_MAX - sizeof(struct udphdr))
677 		return -EMSGSIZE;
678 
679 	if (up->pending) {
680 		/*
681 		 * There are pending frames.
682 		 * The socket lock must be held while it's corked.
683 		 */
684 		lock_sock(sk);
685 		if (likely(up->pending)) {
686 			if (unlikely(up->pending != AF_INET6)) {
687 				release_sock(sk);
688 				return -EAFNOSUPPORT;
689 			}
690 			dst = NULL;
691 			goto do_append_data;
692 		}
693 		release_sock(sk);
694 	}
695 	ulen += sizeof(struct udphdr);
696 
697 	memset(fl, 0, sizeof(*fl));
698 
699 	if (sin6) {
700 		if (sin6->sin6_port == 0)
701 			return -EINVAL;
702 
703 		fl->fl_ip_dport = sin6->sin6_port;
704 		daddr = &sin6->sin6_addr;
705 
706 		if (np->sndflow) {
707 			fl->fl6_flowlabel = sin6->sin6_flowinfo&IPV6_FLOWINFO_MASK;
708 			if (fl->fl6_flowlabel&IPV6_FLOWLABEL_MASK) {
709 				flowlabel = fl6_sock_lookup(sk, fl->fl6_flowlabel);
710 				if (flowlabel == NULL)
711 					return -EINVAL;
712 				daddr = &flowlabel->dst;
713 			}
714 		}
715 
716 		/*
717 		 * Otherwise it will be difficult to maintain
718 		 * sk->sk_dst_cache.
719 		 */
720 		if (sk->sk_state == TCP_ESTABLISHED &&
721 		    ipv6_addr_equal(daddr, &np->daddr))
722 			daddr = &np->daddr;
723 
724 		if (addr_len >= sizeof(struct sockaddr_in6) &&
725 		    sin6->sin6_scope_id &&
726 		    ipv6_addr_type(daddr)&IPV6_ADDR_LINKLOCAL)
727 			fl->oif = sin6->sin6_scope_id;
728 	} else {
729 		if (sk->sk_state != TCP_ESTABLISHED)
730 			return -EDESTADDRREQ;
731 
732 		fl->fl_ip_dport = inet->dport;
733 		daddr = &np->daddr;
734 		fl->fl6_flowlabel = np->flow_label;
735 		connected = 1;
736 	}
737 
738 	if (!fl->oif)
739 		fl->oif = sk->sk_bound_dev_if;
740 
741 	if (msg->msg_controllen) {
742 		opt = &opt_space;
743 		memset(opt, 0, sizeof(struct ipv6_txoptions));
744 		opt->tot_len = sizeof(*opt);
745 
746 		err = datagram_send_ctl(msg, fl, opt, &hlimit, &tclass);
747 		if (err < 0) {
748 			fl6_sock_release(flowlabel);
749 			return err;
750 		}
751 		if ((fl->fl6_flowlabel&IPV6_FLOWLABEL_MASK) && !flowlabel) {
752 			flowlabel = fl6_sock_lookup(sk, fl->fl6_flowlabel);
753 			if (flowlabel == NULL)
754 				return -EINVAL;
755 		}
756 		if (!(opt->opt_nflen|opt->opt_flen))
757 			opt = NULL;
758 		connected = 0;
759 	}
760 	if (opt == NULL)
761 		opt = np->opt;
762 	if (flowlabel)
763 		opt = fl6_merge_options(&opt_space, flowlabel, opt);
764 	opt = ipv6_fixup_options(&opt_space, opt);
765 
766 	fl->proto = IPPROTO_UDP;
767 	ipv6_addr_copy(&fl->fl6_dst, daddr);
768 	if (ipv6_addr_any(&fl->fl6_src) && !ipv6_addr_any(&np->saddr))
769 		ipv6_addr_copy(&fl->fl6_src, &np->saddr);
770 	fl->fl_ip_sport = inet->sport;
771 
772 	/* merge ip6_build_xmit from ip6_output */
773 	if (opt && opt->srcrt) {
774 		struct rt0_hdr *rt0 = (struct rt0_hdr *) opt->srcrt;
775 		ipv6_addr_copy(&final, &fl->fl6_dst);
776 		ipv6_addr_copy(&fl->fl6_dst, rt0->addr);
777 		final_p = &final;
778 		connected = 0;
779 	}
780 
781 	if (!fl->oif && ipv6_addr_is_multicast(&fl->fl6_dst)) {
782 		fl->oif = np->mcast_oif;
783 		connected = 0;
784 	}
785 
786 	err = ip6_dst_lookup(sk, &dst, fl);
787 	if (err)
788 		goto out;
789 	if (final_p)
790 		ipv6_addr_copy(&fl->fl6_dst, final_p);
791 
792 	if ((err = xfrm_lookup(&dst, fl, sk, 0)) < 0)
793 		goto out;
794 
795 	if (hlimit < 0) {
796 		if (ipv6_addr_is_multicast(&fl->fl6_dst))
797 			hlimit = np->mcast_hops;
798 		else
799 			hlimit = np->hop_limit;
800 		if (hlimit < 0)
801 			hlimit = dst_metric(dst, RTAX_HOPLIMIT);
802 		if (hlimit < 0)
803 			hlimit = ipv6_get_hoplimit(dst->dev);
804 	}
805 
806 	if (tclass < 0) {
807 		tclass = np->tclass;
808 		if (tclass < 0)
809 			tclass = 0;
810 	}
811 
812 	if (msg->msg_flags&MSG_CONFIRM)
813 		goto do_confirm;
814 back_from_confirm:
815 
816 	lock_sock(sk);
817 	if (unlikely(up->pending)) {
818 		/* The socket is already corked while preparing it. */
819 		/* ... which is an evident application bug. --ANK */
820 		release_sock(sk);
821 
822 		LIMIT_NETDEBUG(KERN_DEBUG "udp cork app bug 2\n");
823 		err = -EINVAL;
824 		goto out;
825 	}
826 
827 	up->pending = AF_INET6;
828 
829 do_append_data:
830 	up->len += ulen;
831 	err = ip6_append_data(sk, ip_generic_getfrag, msg->msg_iov, ulen,
832 		sizeof(struct udphdr), hlimit, tclass, opt, fl,
833 		(struct rt6_info*)dst,
834 		corkreq ? msg->msg_flags|MSG_MORE : msg->msg_flags);
835 	if (err)
836 		udp_v6_flush_pending_frames(sk);
837 	else if (!corkreq)
838 		err = udp_v6_push_pending_frames(sk, up);
839 
840 	if (dst) {
841 		if (connected) {
842 			ip6_dst_store(sk, dst,
843 				      ipv6_addr_equal(&fl->fl6_dst, &np->daddr) ?
844 				      &np->daddr : NULL);
845 		} else {
846 			dst_release(dst);
847 		}
848 	}
849 
850 	if (err > 0)
851 		err = np->recverr ? net_xmit_errno(err) : 0;
852 	release_sock(sk);
853 out:
854 	fl6_sock_release(flowlabel);
855 	if (!err) {
856 		UDP6_INC_STATS_USER(UDP_MIB_OUTDATAGRAMS);
857 		return len;
858 	}
859 	return err;
860 
861 do_confirm:
862 	dst_confirm(dst);
863 	if (!(msg->msg_flags&MSG_PROBE) || len)
864 		goto back_from_confirm;
865 	err = 0;
866 	goto out;
867 }
868 
869 static int udpv6_destroy_sock(struct sock *sk)
870 {
871 	lock_sock(sk);
872 	udp_v6_flush_pending_frames(sk);
873 	release_sock(sk);
874 
875 	inet6_destroy_sock(sk);
876 
877 	return 0;
878 }
879 
880 /*
881  *	Socket option code for UDP
882  */
883 static int udpv6_setsockopt(struct sock *sk, int level, int optname,
884 			  char __user *optval, int optlen)
885 {
886 	struct udp_sock *up = udp_sk(sk);
887 	int val;
888 	int err = 0;
889 
890 	if (level != SOL_UDP)
891 		return ipv6_setsockopt(sk, level, optname, optval, optlen);
892 
893 	if(optlen<sizeof(int))
894 		return -EINVAL;
895 
896 	if (get_user(val, (int __user *)optval))
897 		return -EFAULT;
898 
899 	switch(optname) {
900 	case UDP_CORK:
901 		if (val != 0) {
902 			up->corkflag = 1;
903 		} else {
904 			up->corkflag = 0;
905 			lock_sock(sk);
906 			udp_v6_push_pending_frames(sk, up);
907 			release_sock(sk);
908 		}
909 		break;
910 
911 	case UDP_ENCAP:
912 		switch (val) {
913 		case 0:
914 			up->encap_type = val;
915 			break;
916 		default:
917 			err = -ENOPROTOOPT;
918 			break;
919 		}
920 		break;
921 
922 	default:
923 		err = -ENOPROTOOPT;
924 		break;
925 	};
926 
927 	return err;
928 }
929 
930 static int udpv6_getsockopt(struct sock *sk, int level, int optname,
931 			  char __user *optval, int __user *optlen)
932 {
933 	struct udp_sock *up = udp_sk(sk);
934 	int val, len;
935 
936 	if (level != SOL_UDP)
937 		return ipv6_getsockopt(sk, level, optname, optval, optlen);
938 
939 	if(get_user(len,optlen))
940 		return -EFAULT;
941 
942 	len = min_t(unsigned int, len, sizeof(int));
943 
944 	if(len < 0)
945 		return -EINVAL;
946 
947 	switch(optname) {
948 	case UDP_CORK:
949 		val = up->corkflag;
950 		break;
951 
952 	case UDP_ENCAP:
953 		val = up->encap_type;
954 		break;
955 
956 	default:
957 		return -ENOPROTOOPT;
958 	};
959 
960   	if(put_user(len, optlen))
961   		return -EFAULT;
962 	if(copy_to_user(optval, &val,len))
963 		return -EFAULT;
964   	return 0;
965 }
966 
967 static struct inet6_protocol udpv6_protocol = {
968 	.handler	=	udpv6_rcv,
969 	.err_handler	=	udpv6_err,
970 	.flags		=	INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
971 };
972 
973 /* ------------------------------------------------------------------------ */
974 #ifdef CONFIG_PROC_FS
975 
976 static void udp6_sock_seq_show(struct seq_file *seq, struct sock *sp, int bucket)
977 {
978 	struct inet_sock *inet = inet_sk(sp);
979 	struct ipv6_pinfo *np = inet6_sk(sp);
980 	struct in6_addr *dest, *src;
981 	__u16 destp, srcp;
982 
983 	dest  = &np->daddr;
984 	src   = &np->rcv_saddr;
985 	destp = ntohs(inet->dport);
986 	srcp  = ntohs(inet->sport);
987 	seq_printf(seq,
988 		   "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
989 		   "%02X %08X:%08X %02X:%08lX %08X %5d %8d %lu %d %p\n",
990 		   bucket,
991 		   src->s6_addr32[0], src->s6_addr32[1],
992 		   src->s6_addr32[2], src->s6_addr32[3], srcp,
993 		   dest->s6_addr32[0], dest->s6_addr32[1],
994 		   dest->s6_addr32[2], dest->s6_addr32[3], destp,
995 		   sp->sk_state,
996 		   atomic_read(&sp->sk_wmem_alloc),
997 		   atomic_read(&sp->sk_rmem_alloc),
998 		   0, 0L, 0,
999 		   sock_i_uid(sp), 0,
1000 		   sock_i_ino(sp),
1001 		   atomic_read(&sp->sk_refcnt), sp);
1002 }
1003 
1004 static int udp6_seq_show(struct seq_file *seq, void *v)
1005 {
1006 	if (v == SEQ_START_TOKEN)
1007 		seq_printf(seq,
1008 			   "  sl  "
1009 			   "local_address                         "
1010 			   "remote_address                        "
1011 			   "st tx_queue rx_queue tr tm->when retrnsmt"
1012 			   "   uid  timeout inode\n");
1013 	else
1014 		udp6_sock_seq_show(seq, v, ((struct udp_iter_state *)seq->private)->bucket);
1015 	return 0;
1016 }
1017 
1018 static struct file_operations udp6_seq_fops;
1019 static struct udp_seq_afinfo udp6_seq_afinfo = {
1020 	.owner		= THIS_MODULE,
1021 	.name		= "udp6",
1022 	.family		= AF_INET6,
1023 	.seq_show	= udp6_seq_show,
1024 	.seq_fops	= &udp6_seq_fops,
1025 };
1026 
1027 int __init udp6_proc_init(void)
1028 {
1029 	return udp_proc_register(&udp6_seq_afinfo);
1030 }
1031 
1032 void udp6_proc_exit(void) {
1033 	udp_proc_unregister(&udp6_seq_afinfo);
1034 }
1035 #endif /* CONFIG_PROC_FS */
1036 
1037 /* ------------------------------------------------------------------------ */
1038 
1039 struct proto udpv6_prot = {
1040 	.name =		"UDPv6",
1041 	.owner =	THIS_MODULE,
1042 	.close =	udpv6_close,
1043 	.connect =	ip6_datagram_connect,
1044 	.disconnect =	udp_disconnect,
1045 	.ioctl =	udp_ioctl,
1046 	.destroy =	udpv6_destroy_sock,
1047 	.setsockopt =	udpv6_setsockopt,
1048 	.getsockopt =	udpv6_getsockopt,
1049 	.sendmsg =	udpv6_sendmsg,
1050 	.recvmsg =	udpv6_recvmsg,
1051 	.backlog_rcv =	udpv6_queue_rcv_skb,
1052 	.hash =		udp_v6_hash,
1053 	.unhash =	udp_v6_unhash,
1054 	.get_port =	udp_v6_get_port,
1055 	.obj_size =	sizeof(struct udp6_sock),
1056 };
1057 
1058 static struct inet_protosw udpv6_protosw = {
1059 	.type =      SOCK_DGRAM,
1060 	.protocol =  IPPROTO_UDP,
1061 	.prot =      &udpv6_prot,
1062 	.ops =       &inet6_dgram_ops,
1063 	.capability =-1,
1064 	.no_check =  UDP_CSUM_DEFAULT,
1065 	.flags =     INET_PROTOSW_PERMANENT,
1066 };
1067 
1068 
1069 void __init udpv6_init(void)
1070 {
1071 	if (inet6_add_protocol(&udpv6_protocol, IPPROTO_UDP) < 0)
1072 		printk(KERN_ERR "udpv6_init: Could not register protocol\n");
1073 	inet6_register_protosw(&udpv6_protosw);
1074 }
1075