1 /*
2  *	UDP over IPv6
3  *	Linux INET6 implementation
4  *
5  *	Authors:
6  *	Pedro Roque		<pedro_m@yahoo.com>
7  *
8  *	Based on linux/ipv4/udp.c
9  *
10  *	$Id: udp.c,v 1.64.2.1 2002/03/05 12:47:34 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  *
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/config.h>
25 #include <linux/errno.h>
26 #include <linux/types.h>
27 #include <linux/socket.h>
28 #include <linux/sockios.h>
29 #include <linux/sched.h>
30 #include <linux/net.h>
31 #include <linux/in6.h>
32 #include <linux/netdevice.h>
33 #include <linux/if_arp.h>
34 #include <linux/ipv6.h>
35 #include <linux/icmpv6.h>
36 #include <linux/init.h>
37 #include <asm/uaccess.h>
38 
39 #include <net/sock.h>
40 #include <net/snmp.h>
41 
42 #include <net/ipv6.h>
43 #include <net/ndisc.h>
44 #include <net/protocol.h>
45 #include <net/transp_v6.h>
46 #include <net/ip6_route.h>
47 #include <net/addrconf.h>
48 #include <net/ip.h>
49 #include <net/udp.h>
50 #include <net/inet_common.h>
51 
52 #include <net/checksum.h>
53 
54 struct udp_mib udp_stats_in6[NR_CPUS*2];
55 
56 /* Grrr, addr_type already calculated by caller, but I don't want
57  * to add some silly "cookie" argument to this method just for that.
58  */
udp_v6_get_port(struct sock * sk,unsigned short snum)59 static int udp_v6_get_port(struct sock *sk, unsigned short snum)
60 {
61 	write_lock_bh(&udp_hash_lock);
62 	if (snum == 0) {
63 		int best_size_so_far, best, result, i;
64 
65 		if (udp_port_rover > sysctl_local_port_range[1] ||
66 		    udp_port_rover < sysctl_local_port_range[0])
67 			udp_port_rover = sysctl_local_port_range[0];
68 		best_size_so_far = 32767;
69 		best = result = udp_port_rover;
70 		for (i = 0; i < UDP_HTABLE_SIZE; i++, result++) {
71 			struct sock *sk;
72 			int size;
73 
74 			sk = udp_hash[result & (UDP_HTABLE_SIZE - 1)];
75 			if (!sk) {
76 				if (result > sysctl_local_port_range[1])
77 					result = sysctl_local_port_range[0] +
78 						((result - sysctl_local_port_range[0]) &
79 						 (UDP_HTABLE_SIZE - 1));
80 				goto gotit;
81 			}
82 			size = 0;
83 			do {
84 				if (++size >= best_size_so_far)
85 					goto next;
86 			} while ((sk = sk->next) != NULL);
87 			best_size_so_far = size;
88 			best = result;
89 		next:;
90 		}
91 		result = best;
92 		for(i = 0; i < (1 << 16) / UDP_HTABLE_SIZE; i++, result += UDP_HTABLE_SIZE) {
93 			if (result > sysctl_local_port_range[1])
94 				result = sysctl_local_port_range[0]
95 					+ ((result - sysctl_local_port_range[0]) &
96 					   (UDP_HTABLE_SIZE - 1));
97 			if (!udp_lport_inuse(result))
98 				break;
99 		}
100 		if (i >= (1 << 16) / UDP_HTABLE_SIZE)
101 			goto fail;
102 gotit:
103 		udp_port_rover = snum = result;
104 	} else {
105 		struct sock *sk2;
106 		int addr_type = ipv6_addr_type(&sk->net_pinfo.af_inet6.rcv_saddr);
107 
108 		for (sk2 = udp_hash[snum & (UDP_HTABLE_SIZE - 1)];
109 		     sk2 != NULL;
110 		     sk2 = sk2->next) {
111 			if (sk2->num == snum &&
112 			    sk2 != sk &&
113 			    (!sk2->bound_dev_if ||
114 			     !sk->bound_dev_if ||
115 			     sk2->bound_dev_if == sk->bound_dev_if) &&
116 			    ((!sk2->rcv_saddr && !ipv6_only_sock(sk)) ||
117 			     (sk2->family == AF_INET6 &&
118 			      ipv6_addr_any(&sk2->net_pinfo.af_inet6.rcv_saddr) &&
119 			      !(ipv6_only_sock(sk2) && addr_type == IPV6_ADDR_MAPPED)) ||
120 			     (addr_type == IPV6_ADDR_ANY &&
121 			      (!ipv6_only_sock(sk) ||
122 			       !(sk2->family == AF_INET6 ? (ipv6_addr_type(&sk2->net_pinfo.af_inet6.rcv_saddr) == IPV6_ADDR_MAPPED) : 1))) ||
123 			     (sk2->family == AF_INET6 &&
124 			      !ipv6_addr_cmp(&sk->net_pinfo.af_inet6.rcv_saddr,
125 					     &sk2->net_pinfo.af_inet6.rcv_saddr)) ||
126 			     (addr_type == IPV6_ADDR_MAPPED &&
127 			      !ipv6_only_sock(sk2) &&
128 			      (!sk2->rcv_saddr ||
129 			       !sk->rcv_saddr ||
130 			       sk->rcv_saddr == sk2->rcv_saddr))) &&
131 			    (!sk2->reuse || !sk->reuse))
132 				goto fail;
133 		}
134 	}
135 
136 	sk->num = snum;
137 	if (sk->pprev == NULL) {
138 		struct sock **skp = &udp_hash[snum & (UDP_HTABLE_SIZE - 1)];
139 		if ((sk->next = *skp) != NULL)
140 			(*skp)->pprev = &sk->next;
141 		*skp = sk;
142 		sk->pprev = skp;
143 		sock_prot_inc_use(sk->prot);
144 		sock_hold(sk);
145 	}
146 	write_unlock_bh(&udp_hash_lock);
147 	return 0;
148 
149 fail:
150 	write_unlock_bh(&udp_hash_lock);
151 	return 1;
152 }
153 
udp_v6_hash(struct sock * sk)154 static void udp_v6_hash(struct sock *sk)
155 {
156 	BUG();
157 }
158 
udp_v6_unhash(struct sock * sk)159 static void udp_v6_unhash(struct sock *sk)
160 {
161  	write_lock_bh(&udp_hash_lock);
162 	if (sk->pprev) {
163 		if (sk->next)
164 			sk->next->pprev = sk->pprev;
165 		*sk->pprev = sk->next;
166 		sk->pprev = NULL;
167 		sk->num = 0;
168 		sock_prot_dec_use(sk->prot);
169 		__sock_put(sk);
170 	}
171 	write_unlock_bh(&udp_hash_lock);
172 }
173 
udp_v6_lookup(struct in6_addr * saddr,u16 sport,struct in6_addr * daddr,u16 dport,int dif)174 static struct sock *udp_v6_lookup(struct in6_addr *saddr, u16 sport,
175 				  struct in6_addr *daddr, u16 dport, int dif)
176 {
177 	struct sock *sk, *result = NULL;
178 	unsigned short hnum = ntohs(dport);
179 	int badness = -1;
180 
181  	read_lock(&udp_hash_lock);
182 	for(sk = udp_hash[hnum & (UDP_HTABLE_SIZE - 1)]; sk != NULL; sk = sk->next) {
183 		if((sk->num == hnum)		&&
184 		   (sk->family == PF_INET6)) {
185 			struct ipv6_pinfo *np = &sk->net_pinfo.af_inet6;
186 			int score = 0;
187 			if(sk->dport) {
188 				if(sk->dport != sport)
189 					continue;
190 				score++;
191 			}
192 			if(!ipv6_addr_any(&np->rcv_saddr)) {
193 				if(ipv6_addr_cmp(&np->rcv_saddr, daddr))
194 					continue;
195 				score++;
196 			}
197 			if(!ipv6_addr_any(&np->daddr)) {
198 				if(ipv6_addr_cmp(&np->daddr, saddr))
199 					continue;
200 				score++;
201 			}
202 			if(sk->bound_dev_if) {
203 				if(sk->bound_dev_if != dif)
204 					continue;
205 				score++;
206 			}
207 			if(score == 4) {
208 				result = sk;
209 				break;
210 			} else if(score > badness) {
211 				result = sk;
212 				badness = score;
213 			}
214 		}
215 	}
216 	if (result)
217 		sock_hold(result);
218  	read_unlock(&udp_hash_lock);
219 	return result;
220 }
221 
222 /*
223  *
224  */
225 
udpv6_connect(struct sock * sk,struct sockaddr * uaddr,int addr_len)226 int udpv6_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
227 {
228 	struct sockaddr_in6	*usin = (struct sockaddr_in6 *) uaddr;
229 	struct ipv6_pinfo      	*np = &sk->net_pinfo.af_inet6;
230 	struct in6_addr		*daddr;
231 	struct in6_addr		saddr;
232 	struct dst_entry	*dst;
233 	struct flowi		fl;
234 	struct ip6_flowlabel	*flowlabel = NULL;
235 	int			addr_type;
236 	int			err;
237 
238 	if (usin->sin6_family == AF_INET) {
239 		if (__ipv6_only_sock(sk))
240 			return -EAFNOSUPPORT;
241 		err = udp_connect(sk, uaddr, addr_len);
242 		goto ipv4_connected;
243 	}
244 
245 	if (addr_len < SIN6_LEN_RFC2133)
246 	  	return -EINVAL;
247 
248 	if (usin->sin6_family != AF_INET6)
249 	  	return -EAFNOSUPPORT;
250 
251 	fl.fl6_flowlabel = 0;
252 	if (np->sndflow) {
253 		fl.fl6_flowlabel = usin->sin6_flowinfo&IPV6_FLOWINFO_MASK;
254 		if (fl.fl6_flowlabel&IPV6_FLOWLABEL_MASK) {
255 			flowlabel = fl6_sock_lookup(sk, fl.fl6_flowlabel);
256 			if (flowlabel == NULL)
257 				return -EINVAL;
258 			ipv6_addr_copy(&usin->sin6_addr, &flowlabel->dst);
259 		}
260 	}
261 
262 	addr_type = ipv6_addr_type(&usin->sin6_addr);
263 
264 	if (addr_type == IPV6_ADDR_ANY) {
265 		/*
266 		 *	connect to self
267 		 */
268 		usin->sin6_addr.s6_addr[15] = 0x01;
269 	}
270 
271 	daddr = &usin->sin6_addr;
272 
273 	if (addr_type == IPV6_ADDR_MAPPED) {
274 		struct sockaddr_in sin;
275 
276 		if (__ipv6_only_sock(sk))
277 			return -ENETUNREACH;
278 
279 		sin.sin_family = AF_INET;
280 		sin.sin_addr.s_addr = daddr->s6_addr32[3];
281 		sin.sin_port = usin->sin6_port;
282 
283 		err = udp_connect(sk, (struct sockaddr*) &sin, sizeof(sin));
284 
285 ipv4_connected:
286 		if (err < 0)
287 			return err;
288 
289 		ipv6_addr_set(&np->daddr, 0, 0,
290 			      htonl(0x0000ffff),
291 			      sk->daddr);
292 
293 		if(ipv6_addr_any(&np->saddr)) {
294 			ipv6_addr_set(&np->saddr, 0, 0,
295 				      htonl(0x0000ffff),
296 				      sk->saddr);
297 		}
298 
299 		if(ipv6_addr_any(&np->rcv_saddr)) {
300 			ipv6_addr_set(&np->rcv_saddr, 0, 0,
301 				      htonl(0x0000ffff),
302 				      sk->rcv_saddr);
303 		}
304 		return 0;
305 	}
306 
307 	if (addr_type&IPV6_ADDR_LINKLOCAL) {
308 		if (addr_len >= sizeof(struct sockaddr_in6) &&
309 		    usin->sin6_scope_id) {
310 			if (sk->bound_dev_if && sk->bound_dev_if != usin->sin6_scope_id) {
311 				fl6_sock_release(flowlabel);
312 				return -EINVAL;
313 			}
314 			sk->bound_dev_if = usin->sin6_scope_id;
315 			if (!sk->bound_dev_if && (addr_type&IPV6_ADDR_MULTICAST))
316 				fl.oif = np->mcast_oif;
317 		}
318 
319 		/* Connect to link-local address requires an interface */
320 		if (sk->bound_dev_if == 0)
321 			return -EINVAL;
322 	}
323 
324 	ipv6_addr_copy(&np->daddr, daddr);
325 	np->flow_label = fl.fl6_flowlabel;
326 
327 	sk->dport = usin->sin6_port;
328 
329 	/*
330 	 *	Check for a route to destination an obtain the
331 	 *	destination cache for it.
332 	 */
333 
334 	fl.proto = IPPROTO_UDP;
335 	fl.fl6_dst = &np->daddr;
336 	fl.fl6_src = &saddr;
337 	fl.oif = sk->bound_dev_if;
338 	fl.uli_u.ports.dport = sk->dport;
339 	fl.uli_u.ports.sport = sk->sport;
340 
341 	if (!fl.oif && (addr_type&IPV6_ADDR_MULTICAST))
342 		fl.oif = np->mcast_oif;
343 
344 	if (flowlabel) {
345 		if (flowlabel->opt && flowlabel->opt->srcrt) {
346 			struct rt0_hdr *rt0 = (struct rt0_hdr *) flowlabel->opt->srcrt;
347 			fl.fl6_dst = rt0->addr;
348 		}
349 	} else if (np->opt && np->opt->srcrt) {
350 		struct rt0_hdr *rt0 = (struct rt0_hdr *) np->opt->srcrt;
351 		fl.fl6_dst = rt0->addr;
352 	}
353 
354 	dst = ip6_route_output(sk, &fl);
355 
356 	if ((err = dst->error) != 0) {
357 		dst_release(dst);
358 		fl6_sock_release(flowlabel);
359 		return err;
360 	}
361 
362 	ip6_dst_store(sk, dst, fl.fl6_dst);
363 
364 	/* get the source adddress used in the apropriate device */
365 
366 	err = ipv6_get_saddr(dst, daddr, &saddr);
367 
368 	if (err == 0) {
369 		if(ipv6_addr_any(&np->saddr))
370 			ipv6_addr_copy(&np->saddr, &saddr);
371 
372 		if(ipv6_addr_any(&np->rcv_saddr)) {
373 			ipv6_addr_copy(&np->rcv_saddr, &saddr);
374 			sk->rcv_saddr = LOOPBACK4_IPV6;
375 		}
376 		sk->state = TCP_ESTABLISHED;
377 	}
378 	fl6_sock_release(flowlabel);
379 
380 	return err;
381 }
382 
udpv6_close(struct sock * sk,long timeout)383 static void udpv6_close(struct sock *sk, long timeout)
384 {
385 	inet_sock_release(sk);
386 }
387 
388 /*
389  * 	This should be easy, if there is something there we
390  * 	return it, otherwise we block.
391  */
392 
udpv6_recvmsg(struct sock * sk,struct msghdr * msg,int len,int noblock,int flags,int * addr_len)393 int udpv6_recvmsg(struct sock *sk, struct msghdr *msg, int len,
394 		  int noblock, int flags, int *addr_len)
395 {
396   	struct sk_buff *skb;
397   	int copied, err;
398 
399   	if (addr_len)
400   		*addr_len=sizeof(struct sockaddr_in6);
401 
402 	if (flags & MSG_ERRQUEUE)
403 		return ipv6_recv_error(sk, msg, len);
404 
405 try_again:
406 	skb = skb_recv_datagram(sk, flags, noblock, &err);
407 	if (!skb)
408 		goto out;
409 
410  	copied = skb->len - sizeof(struct udphdr);
411   	if (copied > len) {
412   		copied = len;
413   		msg->msg_flags |= MSG_TRUNC;
414   	}
415 
416 	if (skb->ip_summed==CHECKSUM_UNNECESSARY) {
417 		err = skb_copy_datagram_iovec(skb, sizeof(struct udphdr), msg->msg_iov,
418 					      copied);
419 	} else if (msg->msg_flags&MSG_TRUNC) {
420 		if ((unsigned short)csum_fold(skb_checksum(skb, 0, skb->len, skb->csum)))
421 			goto csum_copy_err;
422 		err = skb_copy_datagram_iovec(skb, sizeof(struct udphdr), msg->msg_iov,
423 					      copied);
424 	} else {
425 		err = skb_copy_and_csum_datagram_iovec(skb, sizeof(struct udphdr), msg->msg_iov);
426 		if (err == -EINVAL)
427 			goto csum_copy_err;
428 	}
429 	if (err)
430 		goto out_free;
431 
432 	sock_recv_timestamp(msg, sk, skb);
433 
434 	/* Copy the address. */
435 	if (msg->msg_name) {
436 		struct sockaddr_in6 *sin6;
437 
438 		sin6 = (struct sockaddr_in6 *) msg->msg_name;
439 		sin6->sin6_family = AF_INET6;
440 		sin6->sin6_port = skb->h.uh->source;
441 		sin6->sin6_flowinfo = 0;
442 		sin6->sin6_scope_id = 0;
443 
444 		if (skb->protocol == htons(ETH_P_IP)) {
445 			ipv6_addr_set(&sin6->sin6_addr, 0, 0,
446 				      htonl(0xffff), skb->nh.iph->saddr);
447 			if (sk->protinfo.af_inet.cmsg_flags)
448 				ip_cmsg_recv(msg, skb);
449 		} else {
450 			memcpy(&sin6->sin6_addr, &skb->nh.ipv6h->saddr,
451 			       sizeof(struct in6_addr));
452 
453 			if (sk->net_pinfo.af_inet6.rxopt.all)
454 				datagram_recv_ctl(sk, msg, skb);
455 			if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL) {
456 				struct inet6_skb_parm *opt = (struct inet6_skb_parm *) skb->cb;
457 				sin6->sin6_scope_id = opt->iif;
458 			}
459 		}
460   	}
461 
462 	err = copied;
463 	if (flags & MSG_TRUNC)
464 		err = skb->len - sizeof(struct udphdr);
465 
466 out_free:
467 	skb_free_datagram(sk, skb);
468 out:
469 	return err;
470 
471 csum_copy_err:
472 	/* Clear queue. */
473 	if (flags&MSG_PEEK) {
474 		int clear = 0;
475 		spin_lock_irq(&sk->receive_queue.lock);
476 		if (skb == skb_peek(&sk->receive_queue)) {
477 			__skb_unlink(skb, &sk->receive_queue);
478 			clear = 1;
479 		}
480 		spin_unlock_irq(&sk->receive_queue.lock);
481 		if (clear)
482 			kfree_skb(skb);
483 	}
484 
485 	skb_free_datagram(sk, skb);
486 
487 	if (flags & MSG_DONTWAIT) {
488 		UDP6_INC_STATS_USER(UdpInErrors);
489 		return -EAGAIN;
490 	}
491 	goto try_again;
492 }
493 
udpv6_err(struct sk_buff * skb,struct inet6_skb_parm * opt,int type,int code,int offset,__u32 info)494 void udpv6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
495 	       int type, int code, int offset, __u32 info)
496 {
497 	struct ipv6hdr *hdr = (struct ipv6hdr*)skb->data;
498 	struct net_device *dev = skb->dev;
499 	struct in6_addr *saddr = &hdr->saddr;
500 	struct in6_addr *daddr = &hdr->daddr;
501 	struct udphdr *uh = (struct udphdr*)(skb->data+offset);
502 	struct sock *sk;
503 	int err;
504 
505 	sk = udp_v6_lookup(daddr, uh->dest, saddr, uh->source, dev->ifindex);
506 
507 	if (sk == NULL)
508 		return;
509 
510 	if (!icmpv6_err_convert(type, code, &err) &&
511 	    !sk->net_pinfo.af_inet6.recverr)
512 		goto out;
513 
514 	if (sk->state!=TCP_ESTABLISHED &&
515 	    !sk->net_pinfo.af_inet6.recverr)
516 		goto out;
517 
518 	if (sk->net_pinfo.af_inet6.recverr)
519 		ipv6_icmp_error(sk, skb, err, uh->dest, ntohl(info), (u8 *)(uh+1));
520 
521 	sk->err = err;
522 	sk->error_report(sk);
523 out:
524 	sock_put(sk);
525 }
526 
udpv6_queue_rcv_skb(struct sock * sk,struct sk_buff * skb)527 static inline int udpv6_queue_rcv_skb(struct sock * sk, struct sk_buff *skb)
528 {
529 	if (skb->ip_summed != CHECKSUM_UNNECESSARY) {
530 		if ((unsigned short)csum_fold(skb_checksum(skb, 0, skb->len, skb->csum))) {
531 			UDP6_INC_STATS_BH(UdpInErrors);
532 			IP6_INC_STATS_BH(Ip6InDiscards);
533 			kfree_skb(skb);
534 			return 0;
535 		}
536 		skb->ip_summed = CHECKSUM_UNNECESSARY;
537 	}
538 	if (sock_queue_rcv_skb(sk,skb)<0) {
539 		UDP6_INC_STATS_BH(UdpInErrors);
540 		IP6_INC_STATS_BH(Ip6InDiscards);
541 		kfree_skb(skb);
542 		return 0;
543 	}
544   	IP6_INC_STATS_BH(Ip6InDelivers);
545 	UDP6_INC_STATS_BH(UdpInDatagrams);
546 	return 0;
547 }
548 
udp_v6_mcast_next(struct sock * sk,u16 loc_port,struct in6_addr * loc_addr,u16 rmt_port,struct in6_addr * rmt_addr,int dif)549 static struct sock *udp_v6_mcast_next(struct sock *sk,
550 				      u16 loc_port, struct in6_addr *loc_addr,
551 				      u16 rmt_port, struct in6_addr *rmt_addr,
552 				      int dif)
553 {
554 	struct sock *s = sk;
555 	unsigned short num = ntohs(loc_port);
556 	for(; s; s = s->next) {
557 		if(s->num == num) {
558 			struct ipv6_pinfo *np = &s->net_pinfo.af_inet6;
559 			if(s->dport) {
560 				if(s->dport != rmt_port)
561 					continue;
562 			}
563 			if(!ipv6_addr_any(&np->daddr) &&
564 			   ipv6_addr_cmp(&np->daddr, rmt_addr))
565 				continue;
566 
567 			if (s->bound_dev_if && s->bound_dev_if != dif)
568 				continue;
569 
570 			if(!ipv6_addr_any(&np->rcv_saddr)) {
571 				if(ipv6_addr_cmp(&np->rcv_saddr, loc_addr) == 0)
572 					return s;
573 				continue;
574 			}
575 			if(!inet6_mc_check(s, loc_addr, rmt_addr))
576 				continue;
577 			return s;
578 		}
579 	}
580 	return NULL;
581 }
582 
583 /*
584  * Note: called only from the BH handler context,
585  * so we don't need to lock the hashes.
586  */
udpv6_mcast_deliver(struct udphdr * uh,struct in6_addr * saddr,struct in6_addr * daddr,struct sk_buff * skb)587 static void udpv6_mcast_deliver(struct udphdr *uh,
588 				struct in6_addr *saddr, struct in6_addr *daddr,
589 				struct sk_buff *skb)
590 {
591 	struct sock *sk, *sk2;
592 	int dif;
593 
594 	read_lock(&udp_hash_lock);
595 	sk = udp_hash[ntohs(uh->dest) & (UDP_HTABLE_SIZE - 1)];
596 	dif = skb->dev->ifindex;
597 	sk = udp_v6_mcast_next(sk, uh->dest, daddr, uh->source, saddr, dif);
598 	if (!sk) {
599 		kfree_skb(skb);
600 		goto out;
601 	}
602 
603 	sk2 = sk;
604 	while((sk2 = udp_v6_mcast_next(sk2->next, uh->dest, daddr,
605 						  uh->source, saddr, dif))) {
606 		struct sk_buff *buff = skb_clone(skb, GFP_ATOMIC);
607 		if (buff)
608 			udpv6_queue_rcv_skb(sk2, buff);
609 	}
610 	udpv6_queue_rcv_skb(sk, skb);
611 out:
612 	read_unlock(&udp_hash_lock);
613 }
614 
udpv6_rcv(struct sk_buff * skb)615 int udpv6_rcv(struct sk_buff *skb)
616 {
617 	struct sock *sk;
618   	struct udphdr *uh;
619 	struct net_device *dev = skb->dev;
620 	struct in6_addr *saddr, *daddr;
621 	u32 ulen = 0;
622 
623 	if (!pskb_may_pull(skb, sizeof(struct udphdr)))
624 		goto short_packet;
625 
626 	saddr = &skb->nh.ipv6h->saddr;
627 	daddr = &skb->nh.ipv6h->daddr;
628 	uh = skb->h.uh;
629 
630 	ulen = ntohs(uh->len);
631 
632 	/* Check for jumbo payload */
633 	if (ulen == 0)
634 		ulen = skb->len;
635 
636 	if (ulen > skb->len || ulen < sizeof(*uh))
637 		goto short_packet;
638 
639 	if (uh->check == 0) {
640 		/* IPv6 draft-v2 section 8.1 says that we SHOULD log
641 		   this error. Well, it is reasonable.
642 		 */
643 		if (net_ratelimit())
644 			printk(KERN_INFO "IPv6: udp checksum is 0\n");
645 		goto discard;
646 	}
647 
648 	if (ulen < skb->len) {
649 		if (__pskb_trim(skb, ulen))
650 			goto discard;
651 		saddr = &skb->nh.ipv6h->saddr;
652 		daddr = &skb->nh.ipv6h->daddr;
653 		uh = skb->h.uh;
654 	}
655 
656 	if (skb->ip_summed==CHECKSUM_HW) {
657 		skb->ip_summed = CHECKSUM_UNNECESSARY;
658 		if (csum_ipv6_magic(saddr, daddr, ulen, IPPROTO_UDP, skb->csum)) {
659 			NETDEBUG(if (net_ratelimit()) printk(KERN_DEBUG "udp v6 hw csum failure.\n"));
660 			skb->ip_summed = CHECKSUM_NONE;
661 		}
662 	}
663 	if (skb->ip_summed != CHECKSUM_UNNECESSARY)
664 		skb->csum = ~csum_ipv6_magic(saddr, daddr, ulen, IPPROTO_UDP, 0);
665 
666 	/*
667 	 *	Multicast receive code
668 	 */
669 	if (ipv6_addr_type(daddr) & IPV6_ADDR_MULTICAST) {
670 		udpv6_mcast_deliver(uh, saddr, daddr, skb);
671 		return 0;
672 	}
673 
674 	/* Unicast */
675 
676 	/*
677 	 * check socket cache ... must talk to Alan about his plans
678 	 * for sock caches... i'll skip this for now.
679 	 */
680 	sk = udp_v6_lookup(saddr, uh->source, daddr, uh->dest, dev->ifindex);
681 
682 	if (sk == NULL) {
683 		if (skb->ip_summed != CHECKSUM_UNNECESSARY &&
684 		    (unsigned short)csum_fold(skb_checksum(skb, 0, skb->len, skb->csum)))
685 			goto discard;
686 		UDP6_INC_STATS_BH(UdpNoPorts);
687 
688 		icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0, dev);
689 
690 		kfree_skb(skb);
691 		return(0);
692 	}
693 
694 	/* deliver */
695 
696 	udpv6_queue_rcv_skb(sk, skb);
697 	sock_put(sk);
698 	return(0);
699 
700 short_packet:
701 	if (net_ratelimit())
702 		printk(KERN_DEBUG "UDP: short packet: %d/%u\n", ulen, skb->len);
703 
704 discard:
705 	UDP6_INC_STATS_BH(UdpInErrors);
706 	kfree_skb(skb);
707 	return(0);
708 }
709 
710 /*
711  *	Sending
712  */
713 
714 struct udpv6fakehdr
715 {
716 	struct udphdr	uh;
717 	struct iovec	*iov;
718 	__u32		wcheck;
719 	__u32		pl_len;
720 	struct in6_addr *daddr;
721 };
722 
723 /*
724  *	with checksum
725  */
726 
udpv6_getfrag(const void * data,struct in6_addr * addr,char * buff,unsigned int offset,unsigned int len)727 static int udpv6_getfrag(const void *data, struct in6_addr *addr,
728 			 char *buff, unsigned int offset, unsigned int len)
729 {
730 	struct udpv6fakehdr *udh = (struct udpv6fakehdr *) data;
731 	char *dst;
732 	int final = 0;
733 	int clen = len;
734 
735 	dst = buff;
736 
737 	if (offset) {
738 		offset -= sizeof(struct udphdr);
739 	} else {
740 		dst += sizeof(struct udphdr);
741 		final = 1;
742 		clen -= sizeof(struct udphdr);
743 	}
744 
745 	if (csum_partial_copy_fromiovecend(dst, udh->iov, offset,
746 					   clen, &udh->wcheck))
747 		return -EFAULT;
748 
749 	if (final) {
750 		struct in6_addr *daddr;
751 
752 		udh->wcheck = csum_partial((char *)udh, sizeof(struct udphdr),
753 					   udh->wcheck);
754 
755 		if (udh->daddr) {
756 			daddr = udh->daddr;
757 		} else {
758 			/*
759 			 *	use packet destination address
760 			 *	this should improve cache locality
761 			 */
762 			daddr = addr + 1;
763 		}
764 		udh->uh.check = csum_ipv6_magic(addr, daddr,
765 						udh->pl_len, IPPROTO_UDP,
766 						udh->wcheck);
767 		if (udh->uh.check == 0)
768 			udh->uh.check = -1;
769 
770 		memcpy(buff, udh, sizeof(struct udphdr));
771 	}
772 	return 0;
773 }
774 
udpv6_sendmsg(struct sock * sk,struct msghdr * msg,int ulen)775 static int udpv6_sendmsg(struct sock *sk, struct msghdr *msg, int ulen)
776 {
777 	struct ipv6_txoptions opt_space;
778 	struct udpv6fakehdr udh;
779 	struct ipv6_pinfo *np = &sk->net_pinfo.af_inet6;
780 	struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *) msg->msg_name;
781 	struct ipv6_txoptions *opt = NULL;
782 	struct ip6_flowlabel *flowlabel = NULL;
783 	struct flowi fl;
784 	int addr_len = msg->msg_namelen;
785 	struct in6_addr *daddr;
786 	int len = ulen + sizeof(struct udphdr);
787 	int addr_type;
788 	int hlimit = -1;
789 
790 	int err;
791 
792 	/* Rough check on arithmetic overflow,
793 	   better check is made in ip6_build_xmit
794 	   */
795 	if (ulen < 0 || ulen > INT_MAX - sizeof(struct udphdr))
796 		return -EMSGSIZE;
797 
798 	fl.fl6_flowlabel = 0;
799 	fl.oif = 0;
800 
801 	if (sin6) {
802 		if (sin6->sin6_family == AF_INET) {
803 			if (__ipv6_only_sock(sk))
804 				return -ENETUNREACH;
805 			return udp_sendmsg(sk, msg, ulen);
806 		}
807 
808 		if (addr_len < SIN6_LEN_RFC2133)
809 			return -EINVAL;
810 
811 		if (sin6->sin6_family && sin6->sin6_family != AF_INET6)
812 			return -EINVAL;
813 
814 		if (sin6->sin6_port == 0)
815 			return -EINVAL;
816 
817 		udh.uh.dest = sin6->sin6_port;
818 		daddr = &sin6->sin6_addr;
819 
820 		if (np->sndflow) {
821 			fl.fl6_flowlabel = sin6->sin6_flowinfo&IPV6_FLOWINFO_MASK;
822 			if (fl.fl6_flowlabel&IPV6_FLOWLABEL_MASK) {
823 				flowlabel = fl6_sock_lookup(sk, fl.fl6_flowlabel);
824 				if (flowlabel == NULL)
825 					return -EINVAL;
826 				daddr = &flowlabel->dst;
827 			}
828 		}
829 
830 		/* Otherwise it will be difficult to maintain sk->dst_cache. */
831 		if (sk->state == TCP_ESTABLISHED &&
832 		    !ipv6_addr_cmp(daddr, &sk->net_pinfo.af_inet6.daddr))
833 			daddr = &sk->net_pinfo.af_inet6.daddr;
834 
835 		if (addr_len >= sizeof(struct sockaddr_in6) &&
836 		    sin6->sin6_scope_id &&
837 		    ipv6_addr_type(daddr)&IPV6_ADDR_LINKLOCAL)
838 			fl.oif = sin6->sin6_scope_id;
839 	} else {
840 		if (sk->state != TCP_ESTABLISHED)
841 			return -EDESTADDRREQ;
842 
843 		udh.uh.dest = sk->dport;
844 		daddr = &sk->net_pinfo.af_inet6.daddr;
845 		fl.fl6_flowlabel = np->flow_label;
846 	}
847 
848 	addr_type = ipv6_addr_type(daddr);
849 
850 	if (addr_type == IPV6_ADDR_MAPPED) {
851 		struct sockaddr_in sin;
852 
853 		if (__ipv6_only_sock(sk))
854 			return -ENETUNREACH;
855 
856 		sin.sin_family = AF_INET;
857 		sin.sin_addr.s_addr = daddr->s6_addr32[3];
858 		sin.sin_port = udh.uh.dest;
859 		msg->msg_name = (struct sockaddr *)(&sin);
860 		msg->msg_namelen = sizeof(sin);
861 		fl6_sock_release(flowlabel);
862 
863 		return udp_sendmsg(sk, msg, ulen);
864 	}
865 
866 	udh.daddr = NULL;
867 	if (!fl.oif)
868 		fl.oif = sk->bound_dev_if;
869 	fl.fl6_src = NULL;
870 
871 	if (msg->msg_controllen) {
872 		opt = &opt_space;
873 		memset(opt, 0, sizeof(struct ipv6_txoptions));
874 
875 		err = datagram_send_ctl(msg, &fl, opt, &hlimit);
876 		if (err < 0) {
877 			fl6_sock_release(flowlabel);
878 			return err;
879 		}
880 		if ((fl.fl6_flowlabel&IPV6_FLOWLABEL_MASK) && !flowlabel) {
881 			flowlabel = fl6_sock_lookup(sk, fl.fl6_flowlabel);
882 			if (flowlabel == NULL)
883 				return -EINVAL;
884 		}
885 		if (!(opt->opt_nflen|opt->opt_flen))
886 			opt = NULL;
887 	}
888 	if (opt == NULL)
889 		opt = np->opt;
890 	if (flowlabel)
891 		opt = fl6_merge_options(&opt_space, flowlabel, opt);
892 	if (opt && opt->srcrt)
893 		udh.daddr = daddr;
894 
895 	udh.uh.source = sk->sport;
896 	udh.uh.len = len < 0x10000 ? htons(len) : 0;
897 	udh.uh.check = 0;
898 	udh.iov = msg->msg_iov;
899 	udh.wcheck = 0;
900 	udh.pl_len = len;
901 
902 	fl.proto = IPPROTO_UDP;
903 	fl.fl6_dst = daddr;
904 	if (fl.fl6_src == NULL && !ipv6_addr_any(&np->saddr))
905 		fl.fl6_src = &np->saddr;
906 	fl.uli_u.ports.dport = udh.uh.dest;
907 	fl.uli_u.ports.sport = udh.uh.source;
908 
909 	err = ip6_build_xmit(sk, udpv6_getfrag, &udh, &fl, len, opt, hlimit,
910 			     msg->msg_flags);
911 
912 	fl6_sock_release(flowlabel);
913 
914 	if (err < 0)
915 		return err;
916 
917 	UDP6_INC_STATS_USER(UdpOutDatagrams);
918 	return ulen;
919 }
920 
921 static struct inet6_protocol udpv6_protocol =
922 {
923 	udpv6_rcv,		/* UDP handler		*/
924 	udpv6_err,		/* UDP error control	*/
925 	NULL,			/* next			*/
926 	IPPROTO_UDP,		/* protocol ID		*/
927 	0,			/* copy			*/
928 	NULL,			/* data			*/
929 	"UDPv6"			/* name			*/
930 };
931 
932 #define LINE_LEN 190
933 #define LINE_FMT "%-190s\n"
934 
get_udp6_sock(struct sock * sp,char * tmpbuf,int i)935 static void get_udp6_sock(struct sock *sp, char *tmpbuf, int i)
936 {
937 	struct in6_addr *dest, *src;
938 	__u16 destp, srcp;
939 
940 	dest  = &sp->net_pinfo.af_inet6.daddr;
941 	src   = &sp->net_pinfo.af_inet6.rcv_saddr;
942 	destp = ntohs(sp->dport);
943 	srcp  = ntohs(sp->sport);
944 	sprintf(tmpbuf,
945 		"%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
946 		"%02X %08X:%08X %02X:%08lX %08X %5d %8d %lu %d %p",
947 		i,
948 		src->s6_addr32[0], src->s6_addr32[1],
949 		src->s6_addr32[2], src->s6_addr32[3], srcp,
950 		dest->s6_addr32[0], dest->s6_addr32[1],
951 		dest->s6_addr32[2], dest->s6_addr32[3], destp,
952 		sp->state,
953 		atomic_read(&sp->wmem_alloc), atomic_read(&sp->rmem_alloc),
954 		0, 0L, 0,
955 		sock_i_uid(sp), 0,
956 		sock_i_ino(sp),
957 		atomic_read(&sp->refcnt), sp);
958 }
959 
udp6_get_info(char * buffer,char ** start,off_t offset,int length)960 int udp6_get_info(char *buffer, char **start, off_t offset, int length)
961 {
962 	int len = 0, num = 0, i;
963 	off_t pos = 0;
964 	off_t begin;
965 	char tmpbuf[LINE_LEN+2];
966 
967 	if (offset < LINE_LEN+1)
968 		len += sprintf(buffer, LINE_FMT,
969 			       "  sl  "						/* 6 */
970 			       "local_address                         "		/* 38 */
971 			       "remote_address                        "		/* 38 */
972 			       "st tx_queue rx_queue tr tm->when retrnsmt"	/* 41 */
973 			       "   uid  timeout inode");			/* 21 */
974 										/*----*/
975 										/*144 */
976 	pos = LINE_LEN+1;
977 	read_lock(&udp_hash_lock);
978 	for (i = 0; i < UDP_HTABLE_SIZE; i++) {
979 		struct sock *sk;
980 
981 		for (sk = udp_hash[i]; sk; sk = sk->next, num++) {
982 			if (sk->family != PF_INET6)
983 				continue;
984 			pos += LINE_LEN+1;
985 			if (pos <= offset)
986 				continue;
987 			get_udp6_sock(sk, tmpbuf, i);
988 			len += sprintf(buffer+len, LINE_FMT, tmpbuf);
989 			if(len >= length)
990 				goto out;
991 		}
992 	}
993 out:
994 	read_unlock(&udp_hash_lock);
995 	begin = len - (pos - offset);
996 	*start = buffer + begin;
997 	len -= begin;
998 	if(len > length)
999 		len = length;
1000 	if (len < 0)
1001 		len = 0;
1002 	return len;
1003 }
1004 
1005 struct proto udpv6_prot = {
1006 	name:		"UDP",
1007 	close:		udpv6_close,
1008 	connect:	udpv6_connect,
1009 	disconnect:	udp_disconnect,
1010 	ioctl:		udp_ioctl,
1011 	destroy:	inet6_destroy_sock,
1012 	setsockopt:	ipv6_setsockopt,
1013 	getsockopt:	ipv6_getsockopt,
1014 	sendmsg:	udpv6_sendmsg,
1015 	recvmsg:	udpv6_recvmsg,
1016 	backlog_rcv:	udpv6_queue_rcv_skb,
1017 	hash:		udp_v6_hash,
1018 	unhash:		udp_v6_unhash,
1019 	get_port:	udp_v6_get_port,
1020 };
1021 
1022 extern struct proto_ops inet6_dgram_ops;
1023 
1024 static struct inet_protosw udpv6_protosw = {
1025 	type:        SOCK_DGRAM,
1026 	protocol:    IPPROTO_UDP,
1027 	prot:        &udpv6_prot,
1028 	ops:         &inet6_dgram_ops,
1029 	capability:  -1,
1030 	no_check:    UDP_CSUM_DEFAULT,
1031 	flags:       INET_PROTOSW_PERMANENT,
1032 };
1033 
1034 
udpv6_init(void)1035 void __init udpv6_init(void)
1036 {
1037 	inet6_add_protocol(&udpv6_protocol);
1038 	inet6_register_protosw(&udpv6_protosw);
1039 }
1040