xref: /linux/net/ipv6/udp.c (revision 0dd9ac63ce26ec87b080ca9c3e6efed33c23ace6)
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  *	Fixes:
11  *	Hideaki YOSHIFUJI	:	sin6_scope_id support
12  *	YOSHIFUJI Hideaki @USAGI and:	Support IPV6_V6ONLY socket option, which
13  *	Alexey Kuznetsov		allow both IPv4 and IPv6 sockets to bind
14  *					a single port at the same time.
15  *      Kazunori MIYAZAWA @USAGI:       change process style to use ip6_append_data
16  *      YOSHIFUJI Hideaki @USAGI:	convert /proc/net/udp6 to seq_file.
17  *
18  *	This program is free software; you can redistribute it and/or
19  *      modify it under the terms of the GNU General Public License
20  *      as published by the Free Software Foundation; either version
21  *      2 of the License, or (at your option) any later version.
22  */
23 
24 #include <linux/errno.h>
25 #include <linux/types.h>
26 #include <linux/socket.h>
27 #include <linux/sockios.h>
28 #include <linux/net.h>
29 #include <linux/in6.h>
30 #include <linux/netdevice.h>
31 #include <linux/if_arp.h>
32 #include <linux/ipv6.h>
33 #include <linux/icmpv6.h>
34 #include <linux/init.h>
35 #include <linux/module.h>
36 #include <linux/skbuff.h>
37 #include <linux/slab.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 int ipv6_rcv_saddr_equal(const struct sock *sk, const struct sock *sk2)
54 {
55 	const struct in6_addr *sk_rcv_saddr6 = &inet6_sk(sk)->rcv_saddr;
56 	const struct in6_addr *sk2_rcv_saddr6 = inet6_rcv_saddr(sk2);
57 	__be32 sk1_rcv_saddr = inet_sk(sk)->inet_rcv_saddr;
58 	__be32 sk2_rcv_saddr = inet_rcv_saddr(sk2);
59 	int sk_ipv6only = ipv6_only_sock(sk);
60 	int sk2_ipv6only = inet_v6_ipv6only(sk2);
61 	int addr_type = ipv6_addr_type(sk_rcv_saddr6);
62 	int addr_type2 = sk2_rcv_saddr6 ? ipv6_addr_type(sk2_rcv_saddr6) : IPV6_ADDR_MAPPED;
63 
64 	/* if both are mapped, treat as IPv4 */
65 	if (addr_type == IPV6_ADDR_MAPPED && addr_type2 == IPV6_ADDR_MAPPED)
66 		return (!sk2_ipv6only &&
67 			(!sk1_rcv_saddr || !sk2_rcv_saddr ||
68 			  sk1_rcv_saddr == sk2_rcv_saddr));
69 
70 	if (addr_type2 == IPV6_ADDR_ANY &&
71 	    !(sk2_ipv6only && addr_type == IPV6_ADDR_MAPPED))
72 		return 1;
73 
74 	if (addr_type == IPV6_ADDR_ANY &&
75 	    !(sk_ipv6only && addr_type2 == IPV6_ADDR_MAPPED))
76 		return 1;
77 
78 	if (sk2_rcv_saddr6 &&
79 	    ipv6_addr_equal(sk_rcv_saddr6, sk2_rcv_saddr6))
80 		return 1;
81 
82 	return 0;
83 }
84 
85 static unsigned int udp6_portaddr_hash(struct net *net,
86 				       const struct in6_addr *addr6,
87 				       unsigned int port)
88 {
89 	unsigned int hash, mix = net_hash_mix(net);
90 
91 	if (ipv6_addr_any(addr6))
92 		hash = jhash_1word(0, mix);
93 	else if (ipv6_addr_v4mapped(addr6))
94 		hash = jhash_1word((__force u32)addr6->s6_addr32[3], mix);
95 	else
96 		hash = jhash2((__force u32 *)addr6->s6_addr32, 4, mix);
97 
98 	return hash ^ port;
99 }
100 
101 
102 int udp_v6_get_port(struct sock *sk, unsigned short snum)
103 {
104 	unsigned int hash2_nulladdr =
105 		udp6_portaddr_hash(sock_net(sk), &in6addr_any, snum);
106 	unsigned int hash2_partial =
107 		udp6_portaddr_hash(sock_net(sk), &inet6_sk(sk)->rcv_saddr, 0);
108 
109 	/* precompute partial secondary hash */
110 	udp_sk(sk)->udp_portaddr_hash = hash2_partial;
111 	return udp_lib_get_port(sk, snum, ipv6_rcv_saddr_equal, hash2_nulladdr);
112 }
113 
114 static inline int compute_score(struct sock *sk, struct net *net,
115 				unsigned short hnum,
116 				struct in6_addr *saddr, __be16 sport,
117 				struct in6_addr *daddr, __be16 dport,
118 				int dif)
119 {
120 	int score = -1;
121 
122 	if (net_eq(sock_net(sk), net) && udp_sk(sk)->udp_port_hash == hnum &&
123 			sk->sk_family == PF_INET6) {
124 		struct ipv6_pinfo *np = inet6_sk(sk);
125 		struct inet_sock *inet = inet_sk(sk);
126 
127 		score = 0;
128 		if (inet->inet_dport) {
129 			if (inet->inet_dport != sport)
130 				return -1;
131 			score++;
132 		}
133 		if (!ipv6_addr_any(&np->rcv_saddr)) {
134 			if (!ipv6_addr_equal(&np->rcv_saddr, daddr))
135 				return -1;
136 			score++;
137 		}
138 		if (!ipv6_addr_any(&np->daddr)) {
139 			if (!ipv6_addr_equal(&np->daddr, saddr))
140 				return -1;
141 			score++;
142 		}
143 		if (sk->sk_bound_dev_if) {
144 			if (sk->sk_bound_dev_if != dif)
145 				return -1;
146 			score++;
147 		}
148 	}
149 	return score;
150 }
151 
152 #define SCORE2_MAX (1 + 1 + 1)
153 static inline int compute_score2(struct sock *sk, struct net *net,
154 				const struct in6_addr *saddr, __be16 sport,
155 				const struct in6_addr *daddr, unsigned short hnum,
156 				int dif)
157 {
158 	int score = -1;
159 
160 	if (net_eq(sock_net(sk), net) && udp_sk(sk)->udp_port_hash == hnum &&
161 			sk->sk_family == PF_INET6) {
162 		struct ipv6_pinfo *np = inet6_sk(sk);
163 		struct inet_sock *inet = inet_sk(sk);
164 
165 		if (!ipv6_addr_equal(&np->rcv_saddr, daddr))
166 			return -1;
167 		score = 0;
168 		if (inet->inet_dport) {
169 			if (inet->inet_dport != sport)
170 				return -1;
171 			score++;
172 		}
173 		if (!ipv6_addr_any(&np->daddr)) {
174 			if (!ipv6_addr_equal(&np->daddr, saddr))
175 				return -1;
176 			score++;
177 		}
178 		if (sk->sk_bound_dev_if) {
179 			if (sk->sk_bound_dev_if != dif)
180 				return -1;
181 			score++;
182 		}
183 	}
184 	return score;
185 }
186 
187 
188 /* called with read_rcu_lock() */
189 static struct sock *udp6_lib_lookup2(struct net *net,
190 		const struct in6_addr *saddr, __be16 sport,
191 		const struct in6_addr *daddr, unsigned int hnum, int dif,
192 		struct udp_hslot *hslot2, unsigned int slot2)
193 {
194 	struct sock *sk, *result;
195 	struct hlist_nulls_node *node;
196 	int score, badness;
197 
198 begin:
199 	result = NULL;
200 	badness = -1;
201 	udp_portaddr_for_each_entry_rcu(sk, node, &hslot2->head) {
202 		score = compute_score2(sk, net, saddr, sport,
203 				      daddr, hnum, dif);
204 		if (score > badness) {
205 			result = sk;
206 			badness = score;
207 			if (score == SCORE2_MAX)
208 				goto exact_match;
209 		}
210 	}
211 	/*
212 	 * if the nulls value we got at the end of this lookup is
213 	 * not the expected one, we must restart lookup.
214 	 * We probably met an item that was moved to another chain.
215 	 */
216 	if (get_nulls_value(node) != slot2)
217 		goto begin;
218 
219 	if (result) {
220 exact_match:
221 		if (unlikely(!atomic_inc_not_zero(&result->sk_refcnt)))
222 			result = NULL;
223 		else if (unlikely(compute_score2(result, net, saddr, sport,
224 				  daddr, hnum, dif) < badness)) {
225 			sock_put(result);
226 			goto begin;
227 		}
228 	}
229 	return result;
230 }
231 
232 static struct sock *__udp6_lib_lookup(struct net *net,
233 				      struct in6_addr *saddr, __be16 sport,
234 				      struct in6_addr *daddr, __be16 dport,
235 				      int dif, struct udp_table *udptable)
236 {
237 	struct sock *sk, *result;
238 	struct hlist_nulls_node *node;
239 	unsigned short hnum = ntohs(dport);
240 	unsigned int hash2, slot2, slot = udp_hashfn(net, hnum, udptable->mask);
241 	struct udp_hslot *hslot2, *hslot = &udptable->hash[slot];
242 	int score, badness;
243 
244 	rcu_read_lock();
245 	if (hslot->count > 10) {
246 		hash2 = udp6_portaddr_hash(net, daddr, hnum);
247 		slot2 = hash2 & udptable->mask;
248 		hslot2 = &udptable->hash2[slot2];
249 		if (hslot->count < hslot2->count)
250 			goto begin;
251 
252 		result = udp6_lib_lookup2(net, saddr, sport,
253 					  daddr, hnum, dif,
254 					  hslot2, slot2);
255 		if (!result) {
256 			hash2 = udp6_portaddr_hash(net, &in6addr_any, hnum);
257 			slot2 = hash2 & udptable->mask;
258 			hslot2 = &udptable->hash2[slot2];
259 			if (hslot->count < hslot2->count)
260 				goto begin;
261 
262 			result = udp6_lib_lookup2(net, saddr, sport,
263 						  &in6addr_any, hnum, dif,
264 						  hslot2, slot2);
265 		}
266 		rcu_read_unlock();
267 		return result;
268 	}
269 begin:
270 	result = NULL;
271 	badness = -1;
272 	sk_nulls_for_each_rcu(sk, node, &hslot->head) {
273 		score = compute_score(sk, net, hnum, saddr, sport, daddr, dport, dif);
274 		if (score > badness) {
275 			result = sk;
276 			badness = score;
277 		}
278 	}
279 	/*
280 	 * if the nulls value we got at the end of this lookup is
281 	 * not the expected one, we must restart lookup.
282 	 * We probably met an item that was moved to another chain.
283 	 */
284 	if (get_nulls_value(node) != slot)
285 		goto begin;
286 
287 	if (result) {
288 		if (unlikely(!atomic_inc_not_zero(&result->sk_refcnt)))
289 			result = NULL;
290 		else if (unlikely(compute_score(result, net, hnum, saddr, sport,
291 					daddr, dport, dif) < badness)) {
292 			sock_put(result);
293 			goto begin;
294 		}
295 	}
296 	rcu_read_unlock();
297 	return result;
298 }
299 
300 static struct sock *__udp6_lib_lookup_skb(struct sk_buff *skb,
301 					  __be16 sport, __be16 dport,
302 					  struct udp_table *udptable)
303 {
304 	struct sock *sk;
305 	struct ipv6hdr *iph = ipv6_hdr(skb);
306 
307 	if (unlikely(sk = skb_steal_sock(skb)))
308 		return sk;
309 	return __udp6_lib_lookup(dev_net(skb_dst(skb)->dev), &iph->saddr, sport,
310 				 &iph->daddr, dport, inet6_iif(skb),
311 				 udptable);
312 }
313 
314 /*
315  * 	This should be easy, if there is something there we
316  * 	return it, otherwise we block.
317  */
318 
319 int udpv6_recvmsg(struct kiocb *iocb, struct sock *sk,
320 		  struct msghdr *msg, size_t len,
321 		  int noblock, int flags, int *addr_len)
322 {
323 	struct ipv6_pinfo *np = inet6_sk(sk);
324 	struct inet_sock *inet = inet_sk(sk);
325 	struct sk_buff *skb;
326 	unsigned int ulen;
327 	int peeked;
328 	int err;
329 	int is_udplite = IS_UDPLITE(sk);
330 	int is_udp4;
331 	bool slow;
332 
333 	if (addr_len)
334 		*addr_len=sizeof(struct sockaddr_in6);
335 
336 	if (flags & MSG_ERRQUEUE)
337 		return ipv6_recv_error(sk, msg, len);
338 
339 	if (np->rxpmtu && np->rxopt.bits.rxpmtu)
340 		return ipv6_recv_rxpmtu(sk, msg, len);
341 
342 try_again:
343 	skb = __skb_recv_datagram(sk, flags | (noblock ? MSG_DONTWAIT : 0),
344 				  &peeked, &err);
345 	if (!skb)
346 		goto out;
347 
348 	ulen = skb->len - sizeof(struct udphdr);
349 	if (len > ulen)
350 		len = ulen;
351 	else if (len < ulen)
352 		msg->msg_flags |= MSG_TRUNC;
353 
354 	is_udp4 = (skb->protocol == htons(ETH_P_IP));
355 
356 	/*
357 	 * If checksum is needed at all, try to do it while copying the
358 	 * data.  If the data is truncated, or if we only want a partial
359 	 * coverage checksum (UDP-Lite), do it before the copy.
360 	 */
361 
362 	if (len < ulen || UDP_SKB_CB(skb)->partial_cov) {
363 		if (udp_lib_checksum_complete(skb))
364 			goto csum_copy_err;
365 	}
366 
367 	if (skb_csum_unnecessary(skb))
368 		err = skb_copy_datagram_iovec(skb, sizeof(struct udphdr),
369 					      msg->msg_iov,len);
370 	else {
371 		err = skb_copy_and_csum_datagram_iovec(skb, sizeof(struct udphdr), msg->msg_iov);
372 		if (err == -EINVAL)
373 			goto csum_copy_err;
374 	}
375 	if (err)
376 		goto out_free;
377 
378 	if (!peeked) {
379 		if (is_udp4)
380 			UDP_INC_STATS_USER(sock_net(sk),
381 					UDP_MIB_INDATAGRAMS, is_udplite);
382 		else
383 			UDP6_INC_STATS_USER(sock_net(sk),
384 					UDP_MIB_INDATAGRAMS, is_udplite);
385 	}
386 
387 	sock_recv_ts_and_drops(msg, sk, skb);
388 
389 	/* Copy the address. */
390 	if (msg->msg_name) {
391 		struct sockaddr_in6 *sin6;
392 
393 		sin6 = (struct sockaddr_in6 *) msg->msg_name;
394 		sin6->sin6_family = AF_INET6;
395 		sin6->sin6_port = udp_hdr(skb)->source;
396 		sin6->sin6_flowinfo = 0;
397 		sin6->sin6_scope_id = 0;
398 
399 		if (is_udp4)
400 			ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr,
401 					       &sin6->sin6_addr);
402 		else {
403 			ipv6_addr_copy(&sin6->sin6_addr,
404 				       &ipv6_hdr(skb)->saddr);
405 			if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL)
406 				sin6->sin6_scope_id = IP6CB(skb)->iif;
407 		}
408 
409 	}
410 	if (is_udp4) {
411 		if (inet->cmsg_flags)
412 			ip_cmsg_recv(msg, skb);
413 	} else {
414 		if (np->rxopt.all)
415 			datagram_recv_ctl(sk, msg, skb);
416 	}
417 
418 	err = len;
419 	if (flags & MSG_TRUNC)
420 		err = ulen;
421 
422 out_free:
423 	skb_free_datagram_locked(sk, skb);
424 out:
425 	return err;
426 
427 csum_copy_err:
428 	slow = lock_sock_fast(sk);
429 	if (!skb_kill_datagram(sk, skb, flags)) {
430 		if (is_udp4)
431 			UDP_INC_STATS_USER(sock_net(sk),
432 					UDP_MIB_INERRORS, is_udplite);
433 		else
434 			UDP6_INC_STATS_USER(sock_net(sk),
435 					UDP_MIB_INERRORS, is_udplite);
436 	}
437 	unlock_sock_fast(sk, slow);
438 
439 	if (flags & MSG_DONTWAIT)
440 		return -EAGAIN;
441 	goto try_again;
442 }
443 
444 void __udp6_lib_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
445 		    u8 type, u8 code, int offset, __be32 info,
446 		    struct udp_table *udptable)
447 {
448 	struct ipv6_pinfo *np;
449 	struct ipv6hdr *hdr = (struct ipv6hdr*)skb->data;
450 	struct in6_addr *saddr = &hdr->saddr;
451 	struct in6_addr *daddr = &hdr->daddr;
452 	struct udphdr *uh = (struct udphdr*)(skb->data+offset);
453 	struct sock *sk;
454 	int err;
455 
456 	sk = __udp6_lib_lookup(dev_net(skb->dev), daddr, uh->dest,
457 			       saddr, uh->source, inet6_iif(skb), udptable);
458 	if (sk == NULL)
459 		return;
460 
461 	np = inet6_sk(sk);
462 
463 	if (!icmpv6_err_convert(type, code, &err) && !np->recverr)
464 		goto out;
465 
466 	if (sk->sk_state != TCP_ESTABLISHED && !np->recverr)
467 		goto out;
468 
469 	if (np->recverr)
470 		ipv6_icmp_error(sk, skb, err, uh->dest, ntohl(info), (u8 *)(uh+1));
471 
472 	sk->sk_err = err;
473 	sk->sk_error_report(sk);
474 out:
475 	sock_put(sk);
476 }
477 
478 static __inline__ void udpv6_err(struct sk_buff *skb,
479 				 struct inet6_skb_parm *opt, u8 type,
480 				 u8 code, int offset, __be32 info     )
481 {
482 	__udp6_lib_err(skb, opt, type, code, offset, info, &udp_table);
483 }
484 
485 int udpv6_queue_rcv_skb(struct sock * sk, struct sk_buff *skb)
486 {
487 	struct udp_sock *up = udp_sk(sk);
488 	int rc;
489 	int is_udplite = IS_UDPLITE(sk);
490 
491 	if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
492 		goto drop;
493 
494 	/*
495 	 * UDP-Lite specific tests, ignored on UDP sockets (see net/ipv4/udp.c).
496 	 */
497 	if ((is_udplite & UDPLITE_RECV_CC)  &&  UDP_SKB_CB(skb)->partial_cov) {
498 
499 		if (up->pcrlen == 0) {          /* full coverage was set  */
500 			LIMIT_NETDEBUG(KERN_WARNING "UDPLITE6: partial coverage"
501 				" %d while full coverage %d requested\n",
502 				UDP_SKB_CB(skb)->cscov, skb->len);
503 			goto drop;
504 		}
505 		if (UDP_SKB_CB(skb)->cscov  <  up->pcrlen) {
506 			LIMIT_NETDEBUG(KERN_WARNING "UDPLITE6: coverage %d "
507 						    "too small, need min %d\n",
508 				       UDP_SKB_CB(skb)->cscov, up->pcrlen);
509 			goto drop;
510 		}
511 	}
512 
513 	if (sk->sk_filter) {
514 		if (udp_lib_checksum_complete(skb))
515 			goto drop;
516 	}
517 
518 	if ((rc = ip_queue_rcv_skb(sk, skb)) < 0) {
519 		/* Note that an ENOMEM error is charged twice */
520 		if (rc == -ENOMEM)
521 			UDP6_INC_STATS_BH(sock_net(sk),
522 					UDP_MIB_RCVBUFERRORS, is_udplite);
523 		goto drop_no_sk_drops_inc;
524 	}
525 
526 	return 0;
527 drop:
528 	atomic_inc(&sk->sk_drops);
529 drop_no_sk_drops_inc:
530 	UDP6_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
531 	kfree_skb(skb);
532 	return -1;
533 }
534 
535 static struct sock *udp_v6_mcast_next(struct net *net, struct sock *sk,
536 				      __be16 loc_port, struct in6_addr *loc_addr,
537 				      __be16 rmt_port, struct in6_addr *rmt_addr,
538 				      int dif)
539 {
540 	struct hlist_nulls_node *node;
541 	struct sock *s = sk;
542 	unsigned short num = ntohs(loc_port);
543 
544 	sk_nulls_for_each_from(s, node) {
545 		struct inet_sock *inet = inet_sk(s);
546 
547 		if (!net_eq(sock_net(s), net))
548 			continue;
549 
550 		if (udp_sk(s)->udp_port_hash == num &&
551 		    s->sk_family == PF_INET6) {
552 			struct ipv6_pinfo *np = inet6_sk(s);
553 			if (inet->inet_dport) {
554 				if (inet->inet_dport != rmt_port)
555 					continue;
556 			}
557 			if (!ipv6_addr_any(&np->daddr) &&
558 			    !ipv6_addr_equal(&np->daddr, rmt_addr))
559 				continue;
560 
561 			if (s->sk_bound_dev_if && s->sk_bound_dev_if != dif)
562 				continue;
563 
564 			if (!ipv6_addr_any(&np->rcv_saddr)) {
565 				if (!ipv6_addr_equal(&np->rcv_saddr, loc_addr))
566 					continue;
567 			}
568 			if (!inet6_mc_check(s, loc_addr, rmt_addr))
569 				continue;
570 			return s;
571 		}
572 	}
573 	return NULL;
574 }
575 
576 static void flush_stack(struct sock **stack, unsigned int count,
577 			struct sk_buff *skb, unsigned int final)
578 {
579 	unsigned int i;
580 	struct sock *sk;
581 	struct sk_buff *skb1;
582 
583 	for (i = 0; i < count; i++) {
584 		skb1 = (i == final) ? skb : skb_clone(skb, GFP_ATOMIC);
585 
586 		sk = stack[i];
587 		if (skb1) {
588 			if (sk_rcvqueues_full(sk, skb)) {
589 				kfree_skb(skb1);
590 				goto drop;
591 			}
592 			bh_lock_sock(sk);
593 			if (!sock_owned_by_user(sk))
594 				udpv6_queue_rcv_skb(sk, skb1);
595 			else if (sk_add_backlog(sk, skb1)) {
596 				kfree_skb(skb1);
597 				bh_unlock_sock(sk);
598 				goto drop;
599 			}
600 			bh_unlock_sock(sk);
601 			continue;
602 		}
603 drop:
604 		atomic_inc(&sk->sk_drops);
605 		UDP6_INC_STATS_BH(sock_net(sk),
606 				UDP_MIB_RCVBUFERRORS, IS_UDPLITE(sk));
607 		UDP6_INC_STATS_BH(sock_net(sk),
608 				UDP_MIB_INERRORS, IS_UDPLITE(sk));
609 	}
610 }
611 /*
612  * Note: called only from the BH handler context,
613  * so we don't need to lock the hashes.
614  */
615 static int __udp6_lib_mcast_deliver(struct net *net, struct sk_buff *skb,
616 		struct in6_addr *saddr, struct in6_addr *daddr,
617 		struct udp_table *udptable)
618 {
619 	struct sock *sk, *stack[256 / sizeof(struct sock *)];
620 	const struct udphdr *uh = udp_hdr(skb);
621 	struct udp_hslot *hslot = udp_hashslot(udptable, net, ntohs(uh->dest));
622 	int dif;
623 	unsigned int i, count = 0;
624 
625 	spin_lock(&hslot->lock);
626 	sk = sk_nulls_head(&hslot->head);
627 	dif = inet6_iif(skb);
628 	sk = udp_v6_mcast_next(net, sk, uh->dest, daddr, uh->source, saddr, dif);
629 	while (sk) {
630 		stack[count++] = sk;
631 		sk = udp_v6_mcast_next(net, sk_nulls_next(sk), uh->dest, daddr,
632 				       uh->source, saddr, dif);
633 		if (unlikely(count == ARRAY_SIZE(stack))) {
634 			if (!sk)
635 				break;
636 			flush_stack(stack, count, skb, ~0);
637 			count = 0;
638 		}
639 	}
640 	/*
641 	 * before releasing the lock, we must take reference on sockets
642 	 */
643 	for (i = 0; i < count; i++)
644 		sock_hold(stack[i]);
645 
646 	spin_unlock(&hslot->lock);
647 
648 	if (count) {
649 		flush_stack(stack, count, skb, count - 1);
650 
651 		for (i = 0; i < count; i++)
652 			sock_put(stack[i]);
653 	} else {
654 		kfree_skb(skb);
655 	}
656 	return 0;
657 }
658 
659 static inline int udp6_csum_init(struct sk_buff *skb, struct udphdr *uh,
660 				 int proto)
661 {
662 	int err;
663 
664 	UDP_SKB_CB(skb)->partial_cov = 0;
665 	UDP_SKB_CB(skb)->cscov = skb->len;
666 
667 	if (proto == IPPROTO_UDPLITE) {
668 		err = udplite_checksum_init(skb, uh);
669 		if (err)
670 			return err;
671 	}
672 
673 	if (uh->check == 0) {
674 		/* RFC 2460 section 8.1 says that we SHOULD log
675 		   this error. Well, it is reasonable.
676 		 */
677 		LIMIT_NETDEBUG(KERN_INFO "IPv6: udp checksum is 0\n");
678 		return 1;
679 	}
680 	if (skb->ip_summed == CHECKSUM_COMPLETE &&
681 	    !csum_ipv6_magic(&ipv6_hdr(skb)->saddr, &ipv6_hdr(skb)->daddr,
682 			     skb->len, proto, skb->csum))
683 		skb->ip_summed = CHECKSUM_UNNECESSARY;
684 
685 	if (!skb_csum_unnecessary(skb))
686 		skb->csum = ~csum_unfold(csum_ipv6_magic(&ipv6_hdr(skb)->saddr,
687 							 &ipv6_hdr(skb)->daddr,
688 							 skb->len, proto, 0));
689 
690 	return 0;
691 }
692 
693 int __udp6_lib_rcv(struct sk_buff *skb, struct udp_table *udptable,
694 		   int proto)
695 {
696 	struct net *net = dev_net(skb->dev);
697 	struct sock *sk;
698 	struct udphdr *uh;
699 	struct in6_addr *saddr, *daddr;
700 	u32 ulen = 0;
701 
702 	if (!pskb_may_pull(skb, sizeof(struct udphdr)))
703 		goto discard;
704 
705 	saddr = &ipv6_hdr(skb)->saddr;
706 	daddr = &ipv6_hdr(skb)->daddr;
707 	uh = udp_hdr(skb);
708 
709 	ulen = ntohs(uh->len);
710 	if (ulen > skb->len)
711 		goto short_packet;
712 
713 	if (proto == IPPROTO_UDP) {
714 		/* UDP validates ulen. */
715 
716 		/* Check for jumbo payload */
717 		if (ulen == 0)
718 			ulen = skb->len;
719 
720 		if (ulen < sizeof(*uh))
721 			goto short_packet;
722 
723 		if (ulen < skb->len) {
724 			if (pskb_trim_rcsum(skb, ulen))
725 				goto short_packet;
726 			saddr = &ipv6_hdr(skb)->saddr;
727 			daddr = &ipv6_hdr(skb)->daddr;
728 			uh = udp_hdr(skb);
729 		}
730 	}
731 
732 	if (udp6_csum_init(skb, uh, proto))
733 		goto discard;
734 
735 	/*
736 	 *	Multicast receive code
737 	 */
738 	if (ipv6_addr_is_multicast(daddr))
739 		return __udp6_lib_mcast_deliver(net, skb,
740 				saddr, daddr, udptable);
741 
742 	/* Unicast */
743 
744 	/*
745 	 * check socket cache ... must talk to Alan about his plans
746 	 * for sock caches... i'll skip this for now.
747 	 */
748 	sk = __udp6_lib_lookup_skb(skb, uh->source, uh->dest, udptable);
749 
750 	if (sk == NULL) {
751 		if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
752 			goto discard;
753 
754 		if (udp_lib_checksum_complete(skb))
755 			goto discard;
756 		UDP6_INC_STATS_BH(net, UDP_MIB_NOPORTS,
757 				proto == IPPROTO_UDPLITE);
758 
759 		icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0);
760 
761 		kfree_skb(skb);
762 		return 0;
763 	}
764 
765 	/* deliver */
766 
767 	if (sk_rcvqueues_full(sk, skb)) {
768 		sock_put(sk);
769 		goto discard;
770 	}
771 	bh_lock_sock(sk);
772 	if (!sock_owned_by_user(sk))
773 		udpv6_queue_rcv_skb(sk, skb);
774 	else if (sk_add_backlog(sk, skb)) {
775 		atomic_inc(&sk->sk_drops);
776 		bh_unlock_sock(sk);
777 		sock_put(sk);
778 		goto discard;
779 	}
780 	bh_unlock_sock(sk);
781 	sock_put(sk);
782 	return 0;
783 
784 short_packet:
785 	LIMIT_NETDEBUG(KERN_DEBUG "UDP%sv6: short packet: From [%pI6c]:%u %d/%d to [%pI6c]:%u\n",
786 		       proto == IPPROTO_UDPLITE ? "-Lite" : "",
787 		       saddr,
788 		       ntohs(uh->source),
789 		       ulen,
790 		       skb->len,
791 		       daddr,
792 		       ntohs(uh->dest));
793 
794 discard:
795 	UDP6_INC_STATS_BH(net, UDP_MIB_INERRORS, proto == IPPROTO_UDPLITE);
796 	kfree_skb(skb);
797 	return 0;
798 }
799 
800 static __inline__ int udpv6_rcv(struct sk_buff *skb)
801 {
802 	return __udp6_lib_rcv(skb, &udp_table, IPPROTO_UDP);
803 }
804 
805 /*
806  * Throw away all pending data and cancel the corking. Socket is locked.
807  */
808 static void udp_v6_flush_pending_frames(struct sock *sk)
809 {
810 	struct udp_sock *up = udp_sk(sk);
811 
812 	if (up->pending == AF_INET)
813 		udp_flush_pending_frames(sk);
814 	else if (up->pending) {
815 		up->len = 0;
816 		up->pending = 0;
817 		ip6_flush_pending_frames(sk);
818 	}
819 }
820 
821 /**
822  * 	udp6_hwcsum_outgoing  -  handle outgoing HW checksumming
823  * 	@sk: 	socket we are sending on
824  * 	@skb: 	sk_buff containing the filled-in UDP header
825  * 	        (checksum field must be zeroed out)
826  */
827 static void udp6_hwcsum_outgoing(struct sock *sk, struct sk_buff *skb,
828 				 const struct in6_addr *saddr,
829 				 const struct in6_addr *daddr, int len)
830 {
831 	unsigned int offset;
832 	struct udphdr *uh = udp_hdr(skb);
833 	__wsum csum = 0;
834 
835 	if (skb_queue_len(&sk->sk_write_queue) == 1) {
836 		/* Only one fragment on the socket.  */
837 		skb->csum_start = skb_transport_header(skb) - skb->head;
838 		skb->csum_offset = offsetof(struct udphdr, check);
839 		uh->check = ~csum_ipv6_magic(saddr, daddr, len, IPPROTO_UDP, 0);
840 	} else {
841 		/*
842 		 * HW-checksum won't work as there are two or more
843 		 * fragments on the socket so that all csums of sk_buffs
844 		 * should be together
845 		 */
846 		offset = skb_transport_offset(skb);
847 		skb->csum = skb_checksum(skb, offset, skb->len - offset, 0);
848 
849 		skb->ip_summed = CHECKSUM_NONE;
850 
851 		skb_queue_walk(&sk->sk_write_queue, skb) {
852 			csum = csum_add(csum, skb->csum);
853 		}
854 
855 		uh->check = csum_ipv6_magic(saddr, daddr, len, IPPROTO_UDP,
856 					    csum);
857 		if (uh->check == 0)
858 			uh->check = CSUM_MANGLED_0;
859 	}
860 }
861 
862 /*
863  *	Sending
864  */
865 
866 static int udp_v6_push_pending_frames(struct sock *sk)
867 {
868 	struct sk_buff *skb;
869 	struct udphdr *uh;
870 	struct udp_sock  *up = udp_sk(sk);
871 	struct inet_sock *inet = inet_sk(sk);
872 	struct flowi *fl = &inet->cork.fl;
873 	int err = 0;
874 	int is_udplite = IS_UDPLITE(sk);
875 	__wsum csum = 0;
876 
877 	/* Grab the skbuff where UDP header space exists. */
878 	if ((skb = skb_peek(&sk->sk_write_queue)) == NULL)
879 		goto out;
880 
881 	/*
882 	 * Create a UDP header
883 	 */
884 	uh = udp_hdr(skb);
885 	uh->source = fl->fl_ip_sport;
886 	uh->dest = fl->fl_ip_dport;
887 	uh->len = htons(up->len);
888 	uh->check = 0;
889 
890 	if (is_udplite)
891 		csum = udplite_csum_outgoing(sk, skb);
892 	else if (skb->ip_summed == CHECKSUM_PARTIAL) { /* UDP hardware csum */
893 		udp6_hwcsum_outgoing(sk, skb, &fl->fl6_src, &fl->fl6_dst,
894 				     up->len);
895 		goto send;
896 	} else
897 		csum = udp_csum_outgoing(sk, skb);
898 
899 	/* add protocol-dependent pseudo-header */
900 	uh->check = csum_ipv6_magic(&fl->fl6_src, &fl->fl6_dst,
901 				    up->len, fl->proto, csum   );
902 	if (uh->check == 0)
903 		uh->check = CSUM_MANGLED_0;
904 
905 send:
906 	err = ip6_push_pending_frames(sk);
907 	if (err) {
908 		if (err == -ENOBUFS && !inet6_sk(sk)->recverr) {
909 			UDP6_INC_STATS_USER(sock_net(sk),
910 					    UDP_MIB_SNDBUFERRORS, is_udplite);
911 			err = 0;
912 		}
913 	} else
914 		UDP6_INC_STATS_USER(sock_net(sk),
915 				    UDP_MIB_OUTDATAGRAMS, is_udplite);
916 out:
917 	up->len = 0;
918 	up->pending = 0;
919 	return err;
920 }
921 
922 int udpv6_sendmsg(struct kiocb *iocb, struct sock *sk,
923 		  struct msghdr *msg, size_t len)
924 {
925 	struct ipv6_txoptions opt_space;
926 	struct udp_sock *up = udp_sk(sk);
927 	struct inet_sock *inet = inet_sk(sk);
928 	struct ipv6_pinfo *np = inet6_sk(sk);
929 	struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *) msg->msg_name;
930 	struct in6_addr *daddr, *final_p = NULL, final;
931 	struct ipv6_txoptions *opt = NULL;
932 	struct ip6_flowlabel *flowlabel = NULL;
933 	struct flowi fl;
934 	struct dst_entry *dst;
935 	int addr_len = msg->msg_namelen;
936 	int ulen = len;
937 	int hlimit = -1;
938 	int tclass = -1;
939 	int dontfrag = -1;
940 	int corkreq = up->corkflag || msg->msg_flags&MSG_MORE;
941 	int err;
942 	int connected = 0;
943 	int is_udplite = IS_UDPLITE(sk);
944 	int (*getfrag)(void *, char *, int, int, int, struct sk_buff *);
945 
946 	/* destination address check */
947 	if (sin6) {
948 		if (addr_len < offsetof(struct sockaddr, sa_data))
949 			return -EINVAL;
950 
951 		switch (sin6->sin6_family) {
952 		case AF_INET6:
953 			if (addr_len < SIN6_LEN_RFC2133)
954 				return -EINVAL;
955 			daddr = &sin6->sin6_addr;
956 			break;
957 		case AF_INET:
958 			goto do_udp_sendmsg;
959 		case AF_UNSPEC:
960 			msg->msg_name = sin6 = NULL;
961 			msg->msg_namelen = addr_len = 0;
962 			daddr = NULL;
963 			break;
964 		default:
965 			return -EINVAL;
966 		}
967 	} else if (!up->pending) {
968 		if (sk->sk_state != TCP_ESTABLISHED)
969 			return -EDESTADDRREQ;
970 		daddr = &np->daddr;
971 	} else
972 		daddr = NULL;
973 
974 	if (daddr) {
975 		if (ipv6_addr_v4mapped(daddr)) {
976 			struct sockaddr_in sin;
977 			sin.sin_family = AF_INET;
978 			sin.sin_port = sin6 ? sin6->sin6_port : inet->inet_dport;
979 			sin.sin_addr.s_addr = daddr->s6_addr32[3];
980 			msg->msg_name = &sin;
981 			msg->msg_namelen = sizeof(sin);
982 do_udp_sendmsg:
983 			if (__ipv6_only_sock(sk))
984 				return -ENETUNREACH;
985 			return udp_sendmsg(iocb, sk, msg, len);
986 		}
987 	}
988 
989 	if (up->pending == AF_INET)
990 		return udp_sendmsg(iocb, sk, msg, len);
991 
992 	/* Rough check on arithmetic overflow,
993 	   better check is made in ip6_append_data().
994 	   */
995 	if (len > INT_MAX - sizeof(struct udphdr))
996 		return -EMSGSIZE;
997 
998 	if (up->pending) {
999 		/*
1000 		 * There are pending frames.
1001 		 * The socket lock must be held while it's corked.
1002 		 */
1003 		lock_sock(sk);
1004 		if (likely(up->pending)) {
1005 			if (unlikely(up->pending != AF_INET6)) {
1006 				release_sock(sk);
1007 				return -EAFNOSUPPORT;
1008 			}
1009 			dst = NULL;
1010 			goto do_append_data;
1011 		}
1012 		release_sock(sk);
1013 	}
1014 	ulen += sizeof(struct udphdr);
1015 
1016 	memset(&fl, 0, sizeof(fl));
1017 
1018 	if (sin6) {
1019 		if (sin6->sin6_port == 0)
1020 			return -EINVAL;
1021 
1022 		fl.fl_ip_dport = sin6->sin6_port;
1023 		daddr = &sin6->sin6_addr;
1024 
1025 		if (np->sndflow) {
1026 			fl.fl6_flowlabel = sin6->sin6_flowinfo&IPV6_FLOWINFO_MASK;
1027 			if (fl.fl6_flowlabel&IPV6_FLOWLABEL_MASK) {
1028 				flowlabel = fl6_sock_lookup(sk, fl.fl6_flowlabel);
1029 				if (flowlabel == NULL)
1030 					return -EINVAL;
1031 				daddr = &flowlabel->dst;
1032 			}
1033 		}
1034 
1035 		/*
1036 		 * Otherwise it will be difficult to maintain
1037 		 * sk->sk_dst_cache.
1038 		 */
1039 		if (sk->sk_state == TCP_ESTABLISHED &&
1040 		    ipv6_addr_equal(daddr, &np->daddr))
1041 			daddr = &np->daddr;
1042 
1043 		if (addr_len >= sizeof(struct sockaddr_in6) &&
1044 		    sin6->sin6_scope_id &&
1045 		    ipv6_addr_type(daddr)&IPV6_ADDR_LINKLOCAL)
1046 			fl.oif = sin6->sin6_scope_id;
1047 	} else {
1048 		if (sk->sk_state != TCP_ESTABLISHED)
1049 			return -EDESTADDRREQ;
1050 
1051 		fl.fl_ip_dport = inet->inet_dport;
1052 		daddr = &np->daddr;
1053 		fl.fl6_flowlabel = np->flow_label;
1054 		connected = 1;
1055 	}
1056 
1057 	if (!fl.oif)
1058 		fl.oif = sk->sk_bound_dev_if;
1059 
1060 	if (!fl.oif)
1061 		fl.oif = np->sticky_pktinfo.ipi6_ifindex;
1062 
1063 	fl.mark = sk->sk_mark;
1064 
1065 	if (msg->msg_controllen) {
1066 		opt = &opt_space;
1067 		memset(opt, 0, sizeof(struct ipv6_txoptions));
1068 		opt->tot_len = sizeof(*opt);
1069 
1070 		err = datagram_send_ctl(sock_net(sk), msg, &fl, opt, &hlimit,
1071 					&tclass, &dontfrag);
1072 		if (err < 0) {
1073 			fl6_sock_release(flowlabel);
1074 			return err;
1075 		}
1076 		if ((fl.fl6_flowlabel&IPV6_FLOWLABEL_MASK) && !flowlabel) {
1077 			flowlabel = fl6_sock_lookup(sk, fl.fl6_flowlabel);
1078 			if (flowlabel == NULL)
1079 				return -EINVAL;
1080 		}
1081 		if (!(opt->opt_nflen|opt->opt_flen))
1082 			opt = NULL;
1083 		connected = 0;
1084 	}
1085 	if (opt == NULL)
1086 		opt = np->opt;
1087 	if (flowlabel)
1088 		opt = fl6_merge_options(&opt_space, flowlabel, opt);
1089 	opt = ipv6_fixup_options(&opt_space, opt);
1090 
1091 	fl.proto = sk->sk_protocol;
1092 	if (!ipv6_addr_any(daddr))
1093 		ipv6_addr_copy(&fl.fl6_dst, daddr);
1094 	else
1095 		fl.fl6_dst.s6_addr[15] = 0x1; /* :: means loopback (BSD'ism) */
1096 	if (ipv6_addr_any(&fl.fl6_src) && !ipv6_addr_any(&np->saddr))
1097 		ipv6_addr_copy(&fl.fl6_src, &np->saddr);
1098 	fl.fl_ip_sport = inet->inet_sport;
1099 
1100 	/* merge ip6_build_xmit from ip6_output */
1101 	if (opt && opt->srcrt) {
1102 		struct rt0_hdr *rt0 = (struct rt0_hdr *) opt->srcrt;
1103 		ipv6_addr_copy(&final, &fl.fl6_dst);
1104 		ipv6_addr_copy(&fl.fl6_dst, rt0->addr);
1105 		final_p = &final;
1106 		connected = 0;
1107 	}
1108 
1109 	if (!fl.oif && ipv6_addr_is_multicast(&fl.fl6_dst)) {
1110 		fl.oif = np->mcast_oif;
1111 		connected = 0;
1112 	}
1113 
1114 	security_sk_classify_flow(sk, &fl);
1115 
1116 	err = ip6_sk_dst_lookup(sk, &dst, &fl);
1117 	if (err)
1118 		goto out;
1119 	if (final_p)
1120 		ipv6_addr_copy(&fl.fl6_dst, final_p);
1121 
1122 	err = __xfrm_lookup(sock_net(sk), &dst, &fl, sk, XFRM_LOOKUP_WAIT);
1123 	if (err < 0) {
1124 		if (err == -EREMOTE)
1125 			err = ip6_dst_blackhole(sk, &dst, &fl);
1126 		if (err < 0)
1127 			goto out;
1128 	}
1129 
1130 	if (hlimit < 0) {
1131 		if (ipv6_addr_is_multicast(&fl.fl6_dst))
1132 			hlimit = np->mcast_hops;
1133 		else
1134 			hlimit = np->hop_limit;
1135 		if (hlimit < 0)
1136 			hlimit = ip6_dst_hoplimit(dst);
1137 	}
1138 
1139 	if (tclass < 0)
1140 		tclass = np->tclass;
1141 
1142 	if (dontfrag < 0)
1143 		dontfrag = np->dontfrag;
1144 
1145 	if (msg->msg_flags&MSG_CONFIRM)
1146 		goto do_confirm;
1147 back_from_confirm:
1148 
1149 	lock_sock(sk);
1150 	if (unlikely(up->pending)) {
1151 		/* The socket is already corked while preparing it. */
1152 		/* ... which is an evident application bug. --ANK */
1153 		release_sock(sk);
1154 
1155 		LIMIT_NETDEBUG(KERN_DEBUG "udp cork app bug 2\n");
1156 		err = -EINVAL;
1157 		goto out;
1158 	}
1159 
1160 	up->pending = AF_INET6;
1161 
1162 do_append_data:
1163 	up->len += ulen;
1164 	getfrag  =  is_udplite ?  udplite_getfrag : ip_generic_getfrag;
1165 	err = ip6_append_data(sk, getfrag, msg->msg_iov, ulen,
1166 		sizeof(struct udphdr), hlimit, tclass, opt, &fl,
1167 		(struct rt6_info*)dst,
1168 		corkreq ? msg->msg_flags|MSG_MORE : msg->msg_flags, dontfrag);
1169 	if (err)
1170 		udp_v6_flush_pending_frames(sk);
1171 	else if (!corkreq)
1172 		err = udp_v6_push_pending_frames(sk);
1173 	else if (unlikely(skb_queue_empty(&sk->sk_write_queue)))
1174 		up->pending = 0;
1175 
1176 	if (dst) {
1177 		if (connected) {
1178 			ip6_dst_store(sk, dst,
1179 				      ipv6_addr_equal(&fl.fl6_dst, &np->daddr) ?
1180 				      &np->daddr : NULL,
1181 #ifdef CONFIG_IPV6_SUBTREES
1182 				      ipv6_addr_equal(&fl.fl6_src, &np->saddr) ?
1183 				      &np->saddr :
1184 #endif
1185 				      NULL);
1186 		} else {
1187 			dst_release(dst);
1188 		}
1189 		dst = NULL;
1190 	}
1191 
1192 	if (err > 0)
1193 		err = np->recverr ? net_xmit_errno(err) : 0;
1194 	release_sock(sk);
1195 out:
1196 	dst_release(dst);
1197 	fl6_sock_release(flowlabel);
1198 	if (!err)
1199 		return len;
1200 	/*
1201 	 * ENOBUFS = no kernel mem, SOCK_NOSPACE = no sndbuf space.  Reporting
1202 	 * ENOBUFS might not be good (it's not tunable per se), but otherwise
1203 	 * we don't have a good statistic (IpOutDiscards but it can be too many
1204 	 * things).  We could add another new stat but at least for now that
1205 	 * seems like overkill.
1206 	 */
1207 	if (err == -ENOBUFS || test_bit(SOCK_NOSPACE, &sk->sk_socket->flags)) {
1208 		UDP6_INC_STATS_USER(sock_net(sk),
1209 				UDP_MIB_SNDBUFERRORS, is_udplite);
1210 	}
1211 	return err;
1212 
1213 do_confirm:
1214 	dst_confirm(dst);
1215 	if (!(msg->msg_flags&MSG_PROBE) || len)
1216 		goto back_from_confirm;
1217 	err = 0;
1218 	goto out;
1219 }
1220 
1221 void udpv6_destroy_sock(struct sock *sk)
1222 {
1223 	lock_sock(sk);
1224 	udp_v6_flush_pending_frames(sk);
1225 	release_sock(sk);
1226 
1227 	inet6_destroy_sock(sk);
1228 }
1229 
1230 /*
1231  *	Socket option code for UDP
1232  */
1233 int udpv6_setsockopt(struct sock *sk, int level, int optname,
1234 		     char __user *optval, unsigned int optlen)
1235 {
1236 	if (level == SOL_UDP  ||  level == SOL_UDPLITE)
1237 		return udp_lib_setsockopt(sk, level, optname, optval, optlen,
1238 					  udp_v6_push_pending_frames);
1239 	return ipv6_setsockopt(sk, level, optname, optval, optlen);
1240 }
1241 
1242 #ifdef CONFIG_COMPAT
1243 int compat_udpv6_setsockopt(struct sock *sk, int level, int optname,
1244 			    char __user *optval, unsigned int optlen)
1245 {
1246 	if (level == SOL_UDP  ||  level == SOL_UDPLITE)
1247 		return udp_lib_setsockopt(sk, level, optname, optval, optlen,
1248 					  udp_v6_push_pending_frames);
1249 	return compat_ipv6_setsockopt(sk, level, optname, optval, optlen);
1250 }
1251 #endif
1252 
1253 int udpv6_getsockopt(struct sock *sk, int level, int optname,
1254 		     char __user *optval, int __user *optlen)
1255 {
1256 	if (level == SOL_UDP  ||  level == SOL_UDPLITE)
1257 		return udp_lib_getsockopt(sk, level, optname, optval, optlen);
1258 	return ipv6_getsockopt(sk, level, optname, optval, optlen);
1259 }
1260 
1261 #ifdef CONFIG_COMPAT
1262 int compat_udpv6_getsockopt(struct sock *sk, int level, int optname,
1263 			    char __user *optval, int __user *optlen)
1264 {
1265 	if (level == SOL_UDP  ||  level == SOL_UDPLITE)
1266 		return udp_lib_getsockopt(sk, level, optname, optval, optlen);
1267 	return compat_ipv6_getsockopt(sk, level, optname, optval, optlen);
1268 }
1269 #endif
1270 
1271 static int udp6_ufo_send_check(struct sk_buff *skb)
1272 {
1273 	struct ipv6hdr *ipv6h;
1274 	struct udphdr *uh;
1275 
1276 	if (!pskb_may_pull(skb, sizeof(*uh)))
1277 		return -EINVAL;
1278 
1279 	ipv6h = ipv6_hdr(skb);
1280 	uh = udp_hdr(skb);
1281 
1282 	uh->check = ~csum_ipv6_magic(&ipv6h->saddr, &ipv6h->daddr, skb->len,
1283 				     IPPROTO_UDP, 0);
1284 	skb->csum_start = skb_transport_header(skb) - skb->head;
1285 	skb->csum_offset = offsetof(struct udphdr, check);
1286 	skb->ip_summed = CHECKSUM_PARTIAL;
1287 	return 0;
1288 }
1289 
1290 static struct sk_buff *udp6_ufo_fragment(struct sk_buff *skb, int features)
1291 {
1292 	struct sk_buff *segs = ERR_PTR(-EINVAL);
1293 	unsigned int mss;
1294 	unsigned int unfrag_ip6hlen, unfrag_len;
1295 	struct frag_hdr *fptr;
1296 	u8 *mac_start, *prevhdr;
1297 	u8 nexthdr;
1298 	u8 frag_hdr_sz = sizeof(struct frag_hdr);
1299 	int offset;
1300 	__wsum csum;
1301 
1302 	mss = skb_shinfo(skb)->gso_size;
1303 	if (unlikely(skb->len <= mss))
1304 		goto out;
1305 
1306 	if (skb_gso_ok(skb, features | NETIF_F_GSO_ROBUST)) {
1307 		/* Packet is from an untrusted source, reset gso_segs. */
1308 		int type = skb_shinfo(skb)->gso_type;
1309 
1310 		if (unlikely(type & ~(SKB_GSO_UDP | SKB_GSO_DODGY) ||
1311 			     !(type & (SKB_GSO_UDP))))
1312 			goto out;
1313 
1314 		skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(skb->len, mss);
1315 
1316 		segs = NULL;
1317 		goto out;
1318 	}
1319 
1320 	/* Do software UFO. Complete and fill in the UDP checksum as HW cannot
1321 	 * do checksum of UDP packets sent as multiple IP fragments.
1322 	 */
1323 	offset = skb->csum_start - skb_headroom(skb);
1324 	csum = skb_checksum(skb, offset, skb->len- offset, 0);
1325 	offset += skb->csum_offset;
1326 	*(__sum16 *)(skb->data + offset) = csum_fold(csum);
1327 	skb->ip_summed = CHECKSUM_NONE;
1328 
1329 	/* Check if there is enough headroom to insert fragment header. */
1330 	if ((skb_headroom(skb) < frag_hdr_sz) &&
1331 	    pskb_expand_head(skb, frag_hdr_sz, 0, GFP_ATOMIC))
1332 		goto out;
1333 
1334 	/* Find the unfragmentable header and shift it left by frag_hdr_sz
1335 	 * bytes to insert fragment header.
1336 	 */
1337 	unfrag_ip6hlen = ip6_find_1stfragopt(skb, &prevhdr);
1338 	nexthdr = *prevhdr;
1339 	*prevhdr = NEXTHDR_FRAGMENT;
1340 	unfrag_len = skb_network_header(skb) - skb_mac_header(skb) +
1341 		     unfrag_ip6hlen;
1342 	mac_start = skb_mac_header(skb);
1343 	memmove(mac_start-frag_hdr_sz, mac_start, unfrag_len);
1344 
1345 	skb->mac_header -= frag_hdr_sz;
1346 	skb->network_header -= frag_hdr_sz;
1347 
1348 	fptr = (struct frag_hdr *)(skb_network_header(skb) + unfrag_ip6hlen);
1349 	fptr->nexthdr = nexthdr;
1350 	fptr->reserved = 0;
1351 	ipv6_select_ident(fptr);
1352 
1353 	/* Fragment the skb. ipv6 header and the remaining fields of the
1354 	 * fragment header are updated in ipv6_gso_segment()
1355 	 */
1356 	segs = skb_segment(skb, features);
1357 
1358 out:
1359 	return segs;
1360 }
1361 
1362 static const struct inet6_protocol udpv6_protocol = {
1363 	.handler	=	udpv6_rcv,
1364 	.err_handler	=	udpv6_err,
1365 	.gso_send_check =	udp6_ufo_send_check,
1366 	.gso_segment	=	udp6_ufo_fragment,
1367 	.flags		=	INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
1368 };
1369 
1370 /* ------------------------------------------------------------------------ */
1371 #ifdef CONFIG_PROC_FS
1372 
1373 static void udp6_sock_seq_show(struct seq_file *seq, struct sock *sp, int bucket)
1374 {
1375 	struct inet_sock *inet = inet_sk(sp);
1376 	struct ipv6_pinfo *np = inet6_sk(sp);
1377 	struct in6_addr *dest, *src;
1378 	__u16 destp, srcp;
1379 
1380 	dest  = &np->daddr;
1381 	src   = &np->rcv_saddr;
1382 	destp = ntohs(inet->inet_dport);
1383 	srcp  = ntohs(inet->inet_sport);
1384 	seq_printf(seq,
1385 		   "%5d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1386 		   "%02X %08X:%08X %02X:%08lX %08X %5d %8d %lu %d %p %d\n",
1387 		   bucket,
1388 		   src->s6_addr32[0], src->s6_addr32[1],
1389 		   src->s6_addr32[2], src->s6_addr32[3], srcp,
1390 		   dest->s6_addr32[0], dest->s6_addr32[1],
1391 		   dest->s6_addr32[2], dest->s6_addr32[3], destp,
1392 		   sp->sk_state,
1393 		   sk_wmem_alloc_get(sp),
1394 		   sk_rmem_alloc_get(sp),
1395 		   0, 0L, 0,
1396 		   sock_i_uid(sp), 0,
1397 		   sock_i_ino(sp),
1398 		   atomic_read(&sp->sk_refcnt), sp,
1399 		   atomic_read(&sp->sk_drops));
1400 }
1401 
1402 int udp6_seq_show(struct seq_file *seq, void *v)
1403 {
1404 	if (v == SEQ_START_TOKEN)
1405 		seq_printf(seq,
1406 			   "  sl  "
1407 			   "local_address                         "
1408 			   "remote_address                        "
1409 			   "st tx_queue rx_queue tr tm->when retrnsmt"
1410 			   "   uid  timeout inode ref pointer drops\n");
1411 	else
1412 		udp6_sock_seq_show(seq, v, ((struct udp_iter_state *)seq->private)->bucket);
1413 	return 0;
1414 }
1415 
1416 static struct udp_seq_afinfo udp6_seq_afinfo = {
1417 	.name		= "udp6",
1418 	.family		= AF_INET6,
1419 	.udp_table	= &udp_table,
1420 	.seq_fops	= {
1421 		.owner	=	THIS_MODULE,
1422 	},
1423 	.seq_ops	= {
1424 		.show		= udp6_seq_show,
1425 	},
1426 };
1427 
1428 int __net_init udp6_proc_init(struct net *net)
1429 {
1430 	return udp_proc_register(net, &udp6_seq_afinfo);
1431 }
1432 
1433 void udp6_proc_exit(struct net *net) {
1434 	udp_proc_unregister(net, &udp6_seq_afinfo);
1435 }
1436 #endif /* CONFIG_PROC_FS */
1437 
1438 /* ------------------------------------------------------------------------ */
1439 
1440 struct proto udpv6_prot = {
1441 	.name		   = "UDPv6",
1442 	.owner		   = THIS_MODULE,
1443 	.close		   = udp_lib_close,
1444 	.connect	   = ip6_datagram_connect,
1445 	.disconnect	   = udp_disconnect,
1446 	.ioctl		   = udp_ioctl,
1447 	.destroy	   = udpv6_destroy_sock,
1448 	.setsockopt	   = udpv6_setsockopt,
1449 	.getsockopt	   = udpv6_getsockopt,
1450 	.sendmsg	   = udpv6_sendmsg,
1451 	.recvmsg	   = udpv6_recvmsg,
1452 	.backlog_rcv	   = udpv6_queue_rcv_skb,
1453 	.hash		   = udp_lib_hash,
1454 	.unhash		   = udp_lib_unhash,
1455 	.get_port	   = udp_v6_get_port,
1456 	.memory_allocated  = &udp_memory_allocated,
1457 	.sysctl_mem	   = sysctl_udp_mem,
1458 	.sysctl_wmem	   = &sysctl_udp_wmem_min,
1459 	.sysctl_rmem	   = &sysctl_udp_rmem_min,
1460 	.obj_size	   = sizeof(struct udp6_sock),
1461 	.slab_flags	   = SLAB_DESTROY_BY_RCU,
1462 	.h.udp_table	   = &udp_table,
1463 #ifdef CONFIG_COMPAT
1464 	.compat_setsockopt = compat_udpv6_setsockopt,
1465 	.compat_getsockopt = compat_udpv6_getsockopt,
1466 #endif
1467 };
1468 
1469 static struct inet_protosw udpv6_protosw = {
1470 	.type =      SOCK_DGRAM,
1471 	.protocol =  IPPROTO_UDP,
1472 	.prot =      &udpv6_prot,
1473 	.ops =       &inet6_dgram_ops,
1474 	.no_check =  UDP_CSUM_DEFAULT,
1475 	.flags =     INET_PROTOSW_PERMANENT,
1476 };
1477 
1478 
1479 int __init udpv6_init(void)
1480 {
1481 	int ret;
1482 
1483 	ret = inet6_add_protocol(&udpv6_protocol, IPPROTO_UDP);
1484 	if (ret)
1485 		goto out;
1486 
1487 	ret = inet6_register_protosw(&udpv6_protosw);
1488 	if (ret)
1489 		goto out_udpv6_protocol;
1490 out:
1491 	return ret;
1492 
1493 out_udpv6_protocol:
1494 	inet6_del_protocol(&udpv6_protocol, IPPROTO_UDP);
1495 	goto out;
1496 }
1497 
1498 void udpv6_exit(void)
1499 {
1500 	inet6_unregister_protosw(&udpv6_protosw);
1501 	inet6_del_protocol(&udpv6_protocol, IPPROTO_UDP);
1502 }
1503