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1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *	UDP over IPv6
4  *	Linux INET6 implementation
5  *
6  *	Authors:
7  *	Pedro Roque		<roque@di.fc.ul.pt>
8  *
9  *	Based on linux/ipv4/udp.c
10  *
11  *	Fixes:
12  *	Hideaki YOSHIFUJI	:	sin6_scope_id support
13  *	YOSHIFUJI Hideaki @USAGI and:	Support IPV6_V6ONLY socket option, which
14  *	Alexey Kuznetsov		allow both IPv4 and IPv6 sockets to bind
15  *					a single port at the same time.
16  *      Kazunori MIYAZAWA @USAGI:       change process style to use ip6_append_data
17  *      YOSHIFUJI Hideaki @USAGI:	convert /proc/net/udp6 to seq_file.
18  */
19 
20 #include <linux/errno.h>
21 #include <linux/types.h>
22 #include <linux/socket.h>
23 #include <linux/sockios.h>
24 #include <linux/net.h>
25 #include <linux/in6.h>
26 #include <linux/netdevice.h>
27 #include <linux/if_arp.h>
28 #include <linux/ipv6.h>
29 #include <linux/icmpv6.h>
30 #include <linux/init.h>
31 #include <linux/module.h>
32 #include <linux/skbuff.h>
33 #include <linux/slab.h>
34 #include <linux/uaccess.h>
35 #include <linux/indirect_call_wrapper.h>
36 
37 #include <net/addrconf.h>
38 #include <net/ndisc.h>
39 #include <net/protocol.h>
40 #include <net/transp_v6.h>
41 #include <net/ip6_route.h>
42 #include <net/raw.h>
43 #include <net/tcp_states.h>
44 #include <net/ip6_checksum.h>
45 #include <net/ip6_tunnel.h>
46 #include <net/xfrm.h>
47 #include <net/inet_hashtables.h>
48 #include <net/inet6_hashtables.h>
49 #include <net/busy_poll.h>
50 #include <net/sock_reuseport.h>
51 
52 #include <linux/proc_fs.h>
53 #include <linux/seq_file.h>
54 #include <trace/events/skb.h>
55 #include "udp_impl.h"
56 
udpv6_destruct_sock(struct sock * sk)57 static void udpv6_destruct_sock(struct sock *sk)
58 {
59 	udp_destruct_common(sk);
60 	inet6_sock_destruct(sk);
61 }
62 
udpv6_init_sock(struct sock * sk)63 int udpv6_init_sock(struct sock *sk)
64 {
65 	skb_queue_head_init(&udp_sk(sk)->reader_queue);
66 	sk->sk_destruct = udpv6_destruct_sock;
67 	return 0;
68 }
69 
udp6_ehashfn(const struct net * net,const struct in6_addr * laddr,const u16 lport,const struct in6_addr * faddr,const __be16 fport)70 static u32 udp6_ehashfn(const struct net *net,
71 			const struct in6_addr *laddr,
72 			const u16 lport,
73 			const struct in6_addr *faddr,
74 			const __be16 fport)
75 {
76 	static u32 udp6_ehash_secret __read_mostly;
77 	static u32 udp_ipv6_hash_secret __read_mostly;
78 
79 	u32 lhash, fhash;
80 
81 	net_get_random_once(&udp6_ehash_secret,
82 			    sizeof(udp6_ehash_secret));
83 	net_get_random_once(&udp_ipv6_hash_secret,
84 			    sizeof(udp_ipv6_hash_secret));
85 
86 	lhash = (__force u32)laddr->s6_addr32[3];
87 	fhash = __ipv6_addr_jhash(faddr, udp_ipv6_hash_secret);
88 
89 	return __inet6_ehashfn(lhash, lport, fhash, fport,
90 			       udp6_ehash_secret + net_hash_mix(net));
91 }
92 
udp_v6_get_port(struct sock * sk,unsigned short snum)93 int udp_v6_get_port(struct sock *sk, unsigned short snum)
94 {
95 	unsigned int hash2_nulladdr =
96 		ipv6_portaddr_hash(sock_net(sk), &in6addr_any, snum);
97 	unsigned int hash2_partial =
98 		ipv6_portaddr_hash(sock_net(sk), &sk->sk_v6_rcv_saddr, 0);
99 
100 	/* precompute partial secondary hash */
101 	udp_sk(sk)->udp_portaddr_hash = hash2_partial;
102 	return udp_lib_get_port(sk, snum, hash2_nulladdr);
103 }
104 
udp_v6_rehash(struct sock * sk)105 void udp_v6_rehash(struct sock *sk)
106 {
107 	u16 new_hash = ipv6_portaddr_hash(sock_net(sk),
108 					  &sk->sk_v6_rcv_saddr,
109 					  inet_sk(sk)->inet_num);
110 
111 	udp_lib_rehash(sk, new_hash);
112 }
113 
compute_score(struct sock * sk,struct net * net,const struct in6_addr * saddr,__be16 sport,const struct in6_addr * daddr,unsigned short hnum,int dif,int sdif)114 static int compute_score(struct sock *sk, struct net *net,
115 			 const struct in6_addr *saddr, __be16 sport,
116 			 const struct in6_addr *daddr, unsigned short hnum,
117 			 int dif, int sdif)
118 {
119 	int score;
120 	struct inet_sock *inet;
121 	bool dev_match;
122 
123 	if (!net_eq(sock_net(sk), net) ||
124 	    udp_sk(sk)->udp_port_hash != hnum ||
125 	    sk->sk_family != PF_INET6)
126 		return -1;
127 
128 	if (!ipv6_addr_equal(&sk->sk_v6_rcv_saddr, daddr))
129 		return -1;
130 
131 	score = 0;
132 	inet = inet_sk(sk);
133 
134 	if (inet->inet_dport) {
135 		if (inet->inet_dport != sport)
136 			return -1;
137 		score++;
138 	}
139 
140 	if (!ipv6_addr_any(&sk->sk_v6_daddr)) {
141 		if (!ipv6_addr_equal(&sk->sk_v6_daddr, saddr))
142 			return -1;
143 		score++;
144 	}
145 
146 	dev_match = udp_sk_bound_dev_eq(net, sk->sk_bound_dev_if, dif, sdif);
147 	if (!dev_match)
148 		return -1;
149 	if (sk->sk_bound_dev_if)
150 		score++;
151 
152 	if (READ_ONCE(sk->sk_incoming_cpu) == raw_smp_processor_id())
153 		score++;
154 
155 	return score;
156 }
157 
158 /* called with rcu_read_lock() */
udp6_lib_lookup2(struct net * net,const struct in6_addr * saddr,__be16 sport,const struct in6_addr * daddr,unsigned int hnum,int dif,int sdif,struct udp_hslot * hslot2,struct sk_buff * skb)159 static struct sock *udp6_lib_lookup2(struct net *net,
160 		const struct in6_addr *saddr, __be16 sport,
161 		const struct in6_addr *daddr, unsigned int hnum,
162 		int dif, int sdif, struct udp_hslot *hslot2,
163 		struct sk_buff *skb)
164 {
165 	struct sock *sk, *result, *reuseport_result;
166 	int score, badness;
167 	u32 hash = 0;
168 
169 	result = NULL;
170 	badness = -1;
171 	udp_portaddr_for_each_entry_rcu(sk, &hslot2->head) {
172 		score = compute_score(sk, net, saddr, sport,
173 				      daddr, hnum, dif, sdif);
174 		if (score > badness) {
175 			reuseport_result = NULL;
176 
177 			if (sk->sk_reuseport &&
178 			    sk->sk_state != TCP_ESTABLISHED) {
179 				hash = udp6_ehashfn(net, daddr, hnum,
180 						    saddr, sport);
181 
182 				reuseport_result = reuseport_select_sock(sk, hash, skb,
183 									 sizeof(struct udphdr));
184 				if (reuseport_result && !reuseport_has_conns(sk, false))
185 					return reuseport_result;
186 			}
187 
188 			result = reuseport_result ? : sk;
189 			badness = score;
190 		}
191 	}
192 	return result;
193 }
194 
195 /* rcu_read_lock() must be held */
__udp6_lib_lookup(struct net * net,const struct in6_addr * saddr,__be16 sport,const struct in6_addr * daddr,__be16 dport,int dif,int sdif,struct udp_table * udptable,struct sk_buff * skb)196 struct sock *__udp6_lib_lookup(struct net *net,
197 			       const struct in6_addr *saddr, __be16 sport,
198 			       const struct in6_addr *daddr, __be16 dport,
199 			       int dif, int sdif, struct udp_table *udptable,
200 			       struct sk_buff *skb)
201 {
202 	unsigned short hnum = ntohs(dport);
203 	unsigned int hash2, slot2;
204 	struct udp_hslot *hslot2;
205 	struct sock *result;
206 
207 	hash2 = ipv6_portaddr_hash(net, daddr, hnum);
208 	slot2 = hash2 & udptable->mask;
209 	hslot2 = &udptable->hash2[slot2];
210 
211 	result = udp6_lib_lookup2(net, saddr, sport,
212 				  daddr, hnum, dif, sdif,
213 				  hslot2, skb);
214 	if (!result) {
215 		hash2 = ipv6_portaddr_hash(net, &in6addr_any, hnum);
216 		slot2 = hash2 & udptable->mask;
217 
218 		hslot2 = &udptable->hash2[slot2];
219 
220 		result = udp6_lib_lookup2(net, saddr, sport,
221 					  &in6addr_any, hnum, dif, sdif,
222 					  hslot2, skb);
223 	}
224 	if (IS_ERR(result))
225 		return NULL;
226 	return result;
227 }
228 EXPORT_SYMBOL_GPL(__udp6_lib_lookup);
229 
__udp6_lib_lookup_skb(struct sk_buff * skb,__be16 sport,__be16 dport,struct udp_table * udptable)230 static struct sock *__udp6_lib_lookup_skb(struct sk_buff *skb,
231 					  __be16 sport, __be16 dport,
232 					  struct udp_table *udptable)
233 {
234 	const struct ipv6hdr *iph = ipv6_hdr(skb);
235 
236 	return __udp6_lib_lookup(dev_net(skb->dev), &iph->saddr, sport,
237 				 &iph->daddr, dport, inet6_iif(skb),
238 				 inet6_sdif(skb), udptable, skb);
239 }
240 
udp6_lib_lookup_skb(struct sk_buff * skb,__be16 sport,__be16 dport)241 struct sock *udp6_lib_lookup_skb(struct sk_buff *skb,
242 				 __be16 sport, __be16 dport)
243 {
244 	const struct ipv6hdr *iph = ipv6_hdr(skb);
245 
246 	return __udp6_lib_lookup(dev_net(skb->dev), &iph->saddr, sport,
247 				 &iph->daddr, dport, inet6_iif(skb),
248 				 inet6_sdif(skb), &udp_table, NULL);
249 }
250 EXPORT_SYMBOL_GPL(udp6_lib_lookup_skb);
251 
252 /* Must be called under rcu_read_lock().
253  * Does increment socket refcount.
254  */
255 #if IS_ENABLED(CONFIG_NF_TPROXY_IPV6) || IS_ENABLED(CONFIG_NF_SOCKET_IPV6)
udp6_lib_lookup(struct net * net,const struct in6_addr * saddr,__be16 sport,const struct in6_addr * daddr,__be16 dport,int dif)256 struct sock *udp6_lib_lookup(struct net *net, const struct in6_addr *saddr, __be16 sport,
257 			     const struct in6_addr *daddr, __be16 dport, int dif)
258 {
259 	struct sock *sk;
260 
261 	sk =  __udp6_lib_lookup(net, saddr, sport, daddr, dport,
262 				dif, 0, &udp_table, NULL);
263 	if (sk && !refcount_inc_not_zero(&sk->sk_refcnt))
264 		sk = NULL;
265 	return sk;
266 }
267 EXPORT_SYMBOL_GPL(udp6_lib_lookup);
268 #endif
269 
270 /* do not use the scratch area len for jumbogram: their length execeeds the
271  * scratch area space; note that the IP6CB flags is still in the first
272  * cacheline, so checking for jumbograms is cheap
273  */
udp6_skb_len(struct sk_buff * skb)274 static int udp6_skb_len(struct sk_buff *skb)
275 {
276 	return unlikely(inet6_is_jumbogram(skb)) ? skb->len : udp_skb_len(skb);
277 }
278 
279 /*
280  *	This should be easy, if there is something there we
281  *	return it, otherwise we block.
282  */
283 
udpv6_recvmsg(struct sock * sk,struct msghdr * msg,size_t len,int noblock,int flags,int * addr_len)284 int udpv6_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
285 		  int noblock, int flags, int *addr_len)
286 {
287 	struct ipv6_pinfo *np = inet6_sk(sk);
288 	struct inet_sock *inet = inet_sk(sk);
289 	struct sk_buff *skb;
290 	unsigned int ulen, copied;
291 	int off, err, peeking = flags & MSG_PEEK;
292 	int is_udplite = IS_UDPLITE(sk);
293 	struct udp_mib __percpu *mib;
294 	bool checksum_valid = false;
295 	int is_udp4;
296 
297 	if (flags & MSG_ERRQUEUE)
298 		return ipv6_recv_error(sk, msg, len, addr_len);
299 
300 	if (np->rxpmtu && np->rxopt.bits.rxpmtu)
301 		return ipv6_recv_rxpmtu(sk, msg, len, addr_len);
302 
303 try_again:
304 	off = sk_peek_offset(sk, flags);
305 	skb = __skb_recv_udp(sk, flags, noblock, &off, &err);
306 	if (!skb)
307 		return err;
308 
309 	ulen = udp6_skb_len(skb);
310 	copied = len;
311 	if (copied > ulen - off)
312 		copied = ulen - off;
313 	else if (copied < ulen)
314 		msg->msg_flags |= MSG_TRUNC;
315 
316 	is_udp4 = (skb->protocol == htons(ETH_P_IP));
317 	mib = __UDPX_MIB(sk, is_udp4);
318 
319 	/*
320 	 * If checksum is needed at all, try to do it while copying the
321 	 * data.  If the data is truncated, or if we only want a partial
322 	 * coverage checksum (UDP-Lite), do it before the copy.
323 	 */
324 
325 	if (copied < ulen || peeking ||
326 	    (is_udplite && UDP_SKB_CB(skb)->partial_cov)) {
327 		checksum_valid = udp_skb_csum_unnecessary(skb) ||
328 				!__udp_lib_checksum_complete(skb);
329 		if (!checksum_valid)
330 			goto csum_copy_err;
331 	}
332 
333 	if (checksum_valid || udp_skb_csum_unnecessary(skb)) {
334 		if (udp_skb_is_linear(skb))
335 			err = copy_linear_skb(skb, copied, off, &msg->msg_iter);
336 		else
337 			err = skb_copy_datagram_msg(skb, off, msg, copied);
338 	} else {
339 		err = skb_copy_and_csum_datagram_msg(skb, off, msg);
340 		if (err == -EINVAL)
341 			goto csum_copy_err;
342 	}
343 	if (unlikely(err)) {
344 		if (!peeking) {
345 			atomic_inc(&sk->sk_drops);
346 			SNMP_INC_STATS(mib, UDP_MIB_INERRORS);
347 		}
348 		kfree_skb(skb);
349 		return err;
350 	}
351 	if (!peeking)
352 		SNMP_INC_STATS(mib, UDP_MIB_INDATAGRAMS);
353 
354 	sock_recv_ts_and_drops(msg, sk, skb);
355 
356 	/* Copy the address. */
357 	if (msg->msg_name) {
358 		DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name);
359 		sin6->sin6_family = AF_INET6;
360 		sin6->sin6_port = udp_hdr(skb)->source;
361 		sin6->sin6_flowinfo = 0;
362 
363 		if (is_udp4) {
364 			ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr,
365 					       &sin6->sin6_addr);
366 			sin6->sin6_scope_id = 0;
367 		} else {
368 			sin6->sin6_addr = ipv6_hdr(skb)->saddr;
369 			sin6->sin6_scope_id =
370 				ipv6_iface_scope_id(&sin6->sin6_addr,
371 						    inet6_iif(skb));
372 		}
373 		*addr_len = sizeof(*sin6);
374 
375 		if (cgroup_bpf_enabled)
376 			BPF_CGROUP_RUN_PROG_UDP6_RECVMSG_LOCK(sk,
377 						(struct sockaddr *)sin6);
378 	}
379 
380 	if (udp_sk(sk)->gro_enabled)
381 		udp_cmsg_recv(msg, sk, skb);
382 
383 	if (np->rxopt.all)
384 		ip6_datagram_recv_common_ctl(sk, msg, skb);
385 
386 	if (is_udp4) {
387 		if (inet->cmsg_flags)
388 			ip_cmsg_recv_offset(msg, sk, skb,
389 					    sizeof(struct udphdr), off);
390 	} else {
391 		if (np->rxopt.all)
392 			ip6_datagram_recv_specific_ctl(sk, msg, skb);
393 	}
394 
395 	err = copied;
396 	if (flags & MSG_TRUNC)
397 		err = ulen;
398 
399 	skb_consume_udp(sk, skb, peeking ? -err : err);
400 	return err;
401 
402 csum_copy_err:
403 	if (!__sk_queue_drop_skb(sk, &udp_sk(sk)->reader_queue, skb, flags,
404 				 udp_skb_destructor)) {
405 		SNMP_INC_STATS(mib, UDP_MIB_CSUMERRORS);
406 		SNMP_INC_STATS(mib, UDP_MIB_INERRORS);
407 	}
408 	kfree_skb(skb);
409 
410 	/* starting over for a new packet, but check if we need to yield */
411 	cond_resched();
412 	msg->msg_flags &= ~MSG_TRUNC;
413 	goto try_again;
414 }
415 
416 DEFINE_STATIC_KEY_FALSE(udpv6_encap_needed_key);
udpv6_encap_enable(void)417 void udpv6_encap_enable(void)
418 {
419 	static_branch_inc(&udpv6_encap_needed_key);
420 }
421 EXPORT_SYMBOL(udpv6_encap_enable);
422 
423 /* Handler for tunnels with arbitrary destination ports: no socket lookup, go
424  * through error handlers in encapsulations looking for a match.
425  */
__udp6_lib_err_encap_no_sk(struct sk_buff * skb,struct inet6_skb_parm * opt,u8 type,u8 code,int offset,__be32 info)426 static int __udp6_lib_err_encap_no_sk(struct sk_buff *skb,
427 				      struct inet6_skb_parm *opt,
428 				      u8 type, u8 code, int offset, __be32 info)
429 {
430 	int i;
431 
432 	for (i = 0; i < MAX_IPTUN_ENCAP_OPS; i++) {
433 		int (*handler)(struct sk_buff *skb, struct inet6_skb_parm *opt,
434 			       u8 type, u8 code, int offset, __be32 info);
435 		const struct ip6_tnl_encap_ops *encap;
436 
437 		encap = rcu_dereference(ip6tun_encaps[i]);
438 		if (!encap)
439 			continue;
440 		handler = encap->err_handler;
441 		if (handler && !handler(skb, opt, type, code, offset, info))
442 			return 0;
443 	}
444 
445 	return -ENOENT;
446 }
447 
448 /* Try to match ICMP errors to UDP tunnels by looking up a socket without
449  * reversing source and destination port: this will match tunnels that force the
450  * same destination port on both endpoints (e.g. VXLAN, GENEVE). Note that
451  * lwtunnels might actually break this assumption by being configured with
452  * different destination ports on endpoints, in this case we won't be able to
453  * trace ICMP messages back to them.
454  *
455  * If this doesn't match any socket, probe tunnels with arbitrary destination
456  * ports (e.g. FoU, GUE): there, the receiving socket is useless, as the port
457  * we've sent packets to won't necessarily match the local destination port.
458  *
459  * Then ask the tunnel implementation to match the error against a valid
460  * association.
461  *
462  * Return an error if we can't find a match, the socket if we need further
463  * processing, zero otherwise.
464  */
__udp6_lib_err_encap(struct net * net,const struct ipv6hdr * hdr,int offset,struct udphdr * uh,struct udp_table * udptable,struct sk_buff * skb,struct inet6_skb_parm * opt,u8 type,u8 code,__be32 info)465 static struct sock *__udp6_lib_err_encap(struct net *net,
466 					 const struct ipv6hdr *hdr, int offset,
467 					 struct udphdr *uh,
468 					 struct udp_table *udptable,
469 					 struct sk_buff *skb,
470 					 struct inet6_skb_parm *opt,
471 					 u8 type, u8 code, __be32 info)
472 {
473 	int network_offset, transport_offset;
474 	struct sock *sk;
475 
476 	network_offset = skb_network_offset(skb);
477 	transport_offset = skb_transport_offset(skb);
478 
479 	/* Network header needs to point to the outer IPv6 header inside ICMP */
480 	skb_reset_network_header(skb);
481 
482 	/* Transport header needs to point to the UDP header */
483 	skb_set_transport_header(skb, offset);
484 
485 	sk = __udp6_lib_lookup(net, &hdr->daddr, uh->source,
486 			       &hdr->saddr, uh->dest,
487 			       inet6_iif(skb), 0, udptable, skb);
488 	if (sk) {
489 		int (*lookup)(struct sock *sk, struct sk_buff *skb);
490 		struct udp_sock *up = udp_sk(sk);
491 
492 		lookup = READ_ONCE(up->encap_err_lookup);
493 		if (!lookup || lookup(sk, skb))
494 			sk = NULL;
495 	}
496 
497 	if (!sk) {
498 		sk = ERR_PTR(__udp6_lib_err_encap_no_sk(skb, opt, type, code,
499 							offset, info));
500 	}
501 
502 	skb_set_transport_header(skb, transport_offset);
503 	skb_set_network_header(skb, network_offset);
504 
505 	return sk;
506 }
507 
__udp6_lib_err(struct sk_buff * skb,struct inet6_skb_parm * opt,u8 type,u8 code,int offset,__be32 info,struct udp_table * udptable)508 int __udp6_lib_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
509 		   u8 type, u8 code, int offset, __be32 info,
510 		   struct udp_table *udptable)
511 {
512 	struct ipv6_pinfo *np;
513 	const struct ipv6hdr *hdr = (const struct ipv6hdr *)skb->data;
514 	const struct in6_addr *saddr = &hdr->saddr;
515 	const struct in6_addr *daddr = &hdr->daddr;
516 	struct udphdr *uh = (struct udphdr *)(skb->data+offset);
517 	bool tunnel = false;
518 	struct sock *sk;
519 	int harderr;
520 	int err;
521 	struct net *net = dev_net(skb->dev);
522 
523 	sk = __udp6_lib_lookup(net, daddr, uh->dest, saddr, uh->source,
524 			       inet6_iif(skb), inet6_sdif(skb), udptable, NULL);
525 	if (!sk) {
526 		/* No socket for error: try tunnels before discarding */
527 		sk = ERR_PTR(-ENOENT);
528 		if (static_branch_unlikely(&udpv6_encap_needed_key)) {
529 			sk = __udp6_lib_err_encap(net, hdr, offset, uh,
530 						  udptable, skb,
531 						  opt, type, code, info);
532 			if (!sk)
533 				return 0;
534 		}
535 
536 		if (IS_ERR(sk)) {
537 			__ICMP6_INC_STATS(net, __in6_dev_get(skb->dev),
538 					  ICMP6_MIB_INERRORS);
539 			return PTR_ERR(sk);
540 		}
541 
542 		tunnel = true;
543 	}
544 
545 	harderr = icmpv6_err_convert(type, code, &err);
546 	np = inet6_sk(sk);
547 
548 	if (type == ICMPV6_PKT_TOOBIG) {
549 		if (!ip6_sk_accept_pmtu(sk))
550 			goto out;
551 		ip6_sk_update_pmtu(skb, sk, info);
552 		if (np->pmtudisc != IPV6_PMTUDISC_DONT)
553 			harderr = 1;
554 	}
555 	if (type == NDISC_REDIRECT) {
556 		if (tunnel) {
557 			ip6_redirect(skb, sock_net(sk), inet6_iif(skb),
558 				     sk->sk_mark, sk->sk_uid);
559 		} else {
560 			ip6_sk_redirect(skb, sk);
561 		}
562 		goto out;
563 	}
564 
565 	/* Tunnels don't have an application socket: don't pass errors back */
566 	if (tunnel)
567 		goto out;
568 
569 	if (!np->recverr) {
570 		if (!harderr || sk->sk_state != TCP_ESTABLISHED)
571 			goto out;
572 	} else {
573 		ipv6_icmp_error(sk, skb, err, uh->dest, ntohl(info), (u8 *)(uh+1));
574 	}
575 
576 	sk->sk_err = err;
577 	sk->sk_error_report(sk);
578 out:
579 	return 0;
580 }
581 
__udpv6_queue_rcv_skb(struct sock * sk,struct sk_buff * skb)582 static int __udpv6_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
583 {
584 	int rc;
585 
586 	if (!ipv6_addr_any(&sk->sk_v6_daddr)) {
587 		sock_rps_save_rxhash(sk, skb);
588 		sk_mark_napi_id(sk, skb);
589 		sk_incoming_cpu_update(sk);
590 	} else {
591 		sk_mark_napi_id_once(sk, skb);
592 	}
593 
594 	rc = __udp_enqueue_schedule_skb(sk, skb);
595 	if (rc < 0) {
596 		int is_udplite = IS_UDPLITE(sk);
597 
598 		/* Note that an ENOMEM error is charged twice */
599 		if (rc == -ENOMEM)
600 			UDP6_INC_STATS(sock_net(sk),
601 					 UDP_MIB_RCVBUFERRORS, is_udplite);
602 		UDP6_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
603 		kfree_skb(skb);
604 		return -1;
605 	}
606 
607 	return 0;
608 }
609 
udpv6_err(struct sk_buff * skb,struct inet6_skb_parm * opt,u8 type,u8 code,int offset,__be32 info)610 static __inline__ int udpv6_err(struct sk_buff *skb,
611 				struct inet6_skb_parm *opt, u8 type,
612 				u8 code, int offset, __be32 info)
613 {
614 	return __udp6_lib_err(skb, opt, type, code, offset, info, &udp_table);
615 }
616 
udpv6_queue_rcv_one_skb(struct sock * sk,struct sk_buff * skb)617 static int udpv6_queue_rcv_one_skb(struct sock *sk, struct sk_buff *skb)
618 {
619 	struct udp_sock *up = udp_sk(sk);
620 	int is_udplite = IS_UDPLITE(sk);
621 
622 	if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
623 		goto drop;
624 
625 	if (static_branch_unlikely(&udpv6_encap_needed_key) && up->encap_type) {
626 		int (*encap_rcv)(struct sock *sk, struct sk_buff *skb);
627 
628 		/*
629 		 * This is an encapsulation socket so pass the skb to
630 		 * the socket's udp_encap_rcv() hook. Otherwise, just
631 		 * fall through and pass this up the UDP socket.
632 		 * up->encap_rcv() returns the following value:
633 		 * =0 if skb was successfully passed to the encap
634 		 *    handler or was discarded by it.
635 		 * >0 if skb should be passed on to UDP.
636 		 * <0 if skb should be resubmitted as proto -N
637 		 */
638 
639 		/* if we're overly short, let UDP handle it */
640 		encap_rcv = READ_ONCE(up->encap_rcv);
641 		if (encap_rcv) {
642 			int ret;
643 
644 			/* Verify checksum before giving to encap */
645 			if (udp_lib_checksum_complete(skb))
646 				goto csum_error;
647 
648 			ret = encap_rcv(sk, skb);
649 			if (ret <= 0) {
650 				__UDP_INC_STATS(sock_net(sk),
651 						UDP_MIB_INDATAGRAMS,
652 						is_udplite);
653 				return -ret;
654 			}
655 		}
656 
657 		/* FALLTHROUGH -- it's a UDP Packet */
658 	}
659 
660 	/*
661 	 * UDP-Lite specific tests, ignored on UDP sockets (see net/ipv4/udp.c).
662 	 */
663 	if ((up->pcflag & UDPLITE_RECV_CC)  &&  UDP_SKB_CB(skb)->partial_cov) {
664 
665 		if (up->pcrlen == 0) {          /* full coverage was set  */
666 			net_dbg_ratelimited("UDPLITE6: partial coverage %d while full coverage %d requested\n",
667 					    UDP_SKB_CB(skb)->cscov, skb->len);
668 			goto drop;
669 		}
670 		if (UDP_SKB_CB(skb)->cscov  <  up->pcrlen) {
671 			net_dbg_ratelimited("UDPLITE6: coverage %d too small, need min %d\n",
672 					    UDP_SKB_CB(skb)->cscov, up->pcrlen);
673 			goto drop;
674 		}
675 	}
676 
677 	prefetch(&sk->sk_rmem_alloc);
678 	if (rcu_access_pointer(sk->sk_filter) &&
679 	    udp_lib_checksum_complete(skb))
680 		goto csum_error;
681 
682 	if (sk_filter_trim_cap(sk, skb, sizeof(struct udphdr)))
683 		goto drop;
684 
685 	udp_csum_pull_header(skb);
686 
687 	skb_dst_drop(skb);
688 
689 	return __udpv6_queue_rcv_skb(sk, skb);
690 
691 csum_error:
692 	__UDP6_INC_STATS(sock_net(sk), UDP_MIB_CSUMERRORS, is_udplite);
693 drop:
694 	__UDP6_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
695 	atomic_inc(&sk->sk_drops);
696 	kfree_skb(skb);
697 	return -1;
698 }
699 
udpv6_queue_rcv_skb(struct sock * sk,struct sk_buff * skb)700 static int udpv6_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
701 {
702 	struct sk_buff *next, *segs;
703 	int ret;
704 
705 	if (likely(!udp_unexpected_gso(sk, skb)))
706 		return udpv6_queue_rcv_one_skb(sk, skb);
707 
708 	__skb_push(skb, -skb_mac_offset(skb));
709 	segs = udp_rcv_segment(sk, skb, false);
710 	for (skb = segs; skb; skb = next) {
711 		next = skb->next;
712 		__skb_pull(skb, skb_transport_offset(skb));
713 
714 		ret = udpv6_queue_rcv_one_skb(sk, skb);
715 		if (ret > 0)
716 			ip6_protocol_deliver_rcu(dev_net(skb->dev), skb, ret,
717 						 true);
718 	}
719 	return 0;
720 }
721 
__udp_v6_is_mcast_sock(struct net * net,struct sock * sk,__be16 loc_port,const struct in6_addr * loc_addr,__be16 rmt_port,const struct in6_addr * rmt_addr,int dif,int sdif,unsigned short hnum)722 static bool __udp_v6_is_mcast_sock(struct net *net, struct sock *sk,
723 				   __be16 loc_port, const struct in6_addr *loc_addr,
724 				   __be16 rmt_port, const struct in6_addr *rmt_addr,
725 				   int dif, int sdif, unsigned short hnum)
726 {
727 	struct inet_sock *inet = inet_sk(sk);
728 
729 	if (!net_eq(sock_net(sk), net))
730 		return false;
731 
732 	if (udp_sk(sk)->udp_port_hash != hnum ||
733 	    sk->sk_family != PF_INET6 ||
734 	    (inet->inet_dport && inet->inet_dport != rmt_port) ||
735 	    (!ipv6_addr_any(&sk->sk_v6_daddr) &&
736 		    !ipv6_addr_equal(&sk->sk_v6_daddr, rmt_addr)) ||
737 	    !udp_sk_bound_dev_eq(net, sk->sk_bound_dev_if, dif, sdif) ||
738 	    (!ipv6_addr_any(&sk->sk_v6_rcv_saddr) &&
739 		    !ipv6_addr_equal(&sk->sk_v6_rcv_saddr, loc_addr)))
740 		return false;
741 	if (!inet6_mc_check(sk, loc_addr, rmt_addr))
742 		return false;
743 	return true;
744 }
745 
udp6_csum_zero_error(struct sk_buff * skb)746 static void udp6_csum_zero_error(struct sk_buff *skb)
747 {
748 	/* RFC 2460 section 8.1 says that we SHOULD log
749 	 * this error. Well, it is reasonable.
750 	 */
751 	net_dbg_ratelimited("IPv6: udp checksum is 0 for [%pI6c]:%u->[%pI6c]:%u\n",
752 			    &ipv6_hdr(skb)->saddr, ntohs(udp_hdr(skb)->source),
753 			    &ipv6_hdr(skb)->daddr, ntohs(udp_hdr(skb)->dest));
754 }
755 
756 /*
757  * Note: called only from the BH handler context,
758  * so we don't need to lock the hashes.
759  */
__udp6_lib_mcast_deliver(struct net * net,struct sk_buff * skb,const struct in6_addr * saddr,const struct in6_addr * daddr,struct udp_table * udptable,int proto)760 static int __udp6_lib_mcast_deliver(struct net *net, struct sk_buff *skb,
761 		const struct in6_addr *saddr, const struct in6_addr *daddr,
762 		struct udp_table *udptable, int proto)
763 {
764 	struct sock *sk, *first = NULL;
765 	const struct udphdr *uh = udp_hdr(skb);
766 	unsigned short hnum = ntohs(uh->dest);
767 	struct udp_hslot *hslot = udp_hashslot(udptable, net, hnum);
768 	unsigned int offset = offsetof(typeof(*sk), sk_node);
769 	unsigned int hash2 = 0, hash2_any = 0, use_hash2 = (hslot->count > 10);
770 	int dif = inet6_iif(skb);
771 	int sdif = inet6_sdif(skb);
772 	struct hlist_node *node;
773 	struct sk_buff *nskb;
774 
775 	if (use_hash2) {
776 		hash2_any = ipv6_portaddr_hash(net, &in6addr_any, hnum) &
777 			    udptable->mask;
778 		hash2 = ipv6_portaddr_hash(net, daddr, hnum) & udptable->mask;
779 start_lookup:
780 		hslot = &udptable->hash2[hash2];
781 		offset = offsetof(typeof(*sk), __sk_common.skc_portaddr_node);
782 	}
783 
784 	sk_for_each_entry_offset_rcu(sk, node, &hslot->head, offset) {
785 		if (!__udp_v6_is_mcast_sock(net, sk, uh->dest, daddr,
786 					    uh->source, saddr, dif, sdif,
787 					    hnum))
788 			continue;
789 		/* If zero checksum and no_check is not on for
790 		 * the socket then skip it.
791 		 */
792 		if (!uh->check && !udp_sk(sk)->no_check6_rx)
793 			continue;
794 		if (!first) {
795 			first = sk;
796 			continue;
797 		}
798 		nskb = skb_clone(skb, GFP_ATOMIC);
799 		if (unlikely(!nskb)) {
800 			atomic_inc(&sk->sk_drops);
801 			__UDP6_INC_STATS(net, UDP_MIB_RCVBUFERRORS,
802 					 IS_UDPLITE(sk));
803 			__UDP6_INC_STATS(net, UDP_MIB_INERRORS,
804 					 IS_UDPLITE(sk));
805 			continue;
806 		}
807 
808 		if (udpv6_queue_rcv_skb(sk, nskb) > 0)
809 			consume_skb(nskb);
810 	}
811 
812 	/* Also lookup *:port if we are using hash2 and haven't done so yet. */
813 	if (use_hash2 && hash2 != hash2_any) {
814 		hash2 = hash2_any;
815 		goto start_lookup;
816 	}
817 
818 	if (first) {
819 		if (udpv6_queue_rcv_skb(first, skb) > 0)
820 			consume_skb(skb);
821 	} else {
822 		kfree_skb(skb);
823 		__UDP6_INC_STATS(net, UDP_MIB_IGNOREDMULTI,
824 				 proto == IPPROTO_UDPLITE);
825 	}
826 	return 0;
827 }
828 
udp6_sk_rx_dst_set(struct sock * sk,struct dst_entry * dst)829 static void udp6_sk_rx_dst_set(struct sock *sk, struct dst_entry *dst)
830 {
831 	if (udp_sk_rx_dst_set(sk, dst)) {
832 		const struct rt6_info *rt = (const struct rt6_info *)dst;
833 
834 		inet6_sk(sk)->rx_dst_cookie = rt6_get_cookie(rt);
835 	}
836 }
837 
838 /* wrapper for udp_queue_rcv_skb tacking care of csum conversion and
839  * return code conversion for ip layer consumption
840  */
udp6_unicast_rcv_skb(struct sock * sk,struct sk_buff * skb,struct udphdr * uh)841 static int udp6_unicast_rcv_skb(struct sock *sk, struct sk_buff *skb,
842 				struct udphdr *uh)
843 {
844 	int ret;
845 
846 	if (inet_get_convert_csum(sk) && uh->check && !IS_UDPLITE(sk))
847 		skb_checksum_try_convert(skb, IPPROTO_UDP, ip6_compute_pseudo);
848 
849 	ret = udpv6_queue_rcv_skb(sk, skb);
850 
851 	/* a return value > 0 means to resubmit the input */
852 	if (ret > 0)
853 		return ret;
854 	return 0;
855 }
856 
__udp6_lib_rcv(struct sk_buff * skb,struct udp_table * udptable,int proto)857 int __udp6_lib_rcv(struct sk_buff *skb, struct udp_table *udptable,
858 		   int proto)
859 {
860 	const struct in6_addr *saddr, *daddr;
861 	struct net *net = dev_net(skb->dev);
862 	struct udphdr *uh;
863 	struct sock *sk;
864 	u32 ulen = 0;
865 
866 	if (!pskb_may_pull(skb, sizeof(struct udphdr)))
867 		goto discard;
868 
869 	saddr = &ipv6_hdr(skb)->saddr;
870 	daddr = &ipv6_hdr(skb)->daddr;
871 	uh = udp_hdr(skb);
872 
873 	ulen = ntohs(uh->len);
874 	if (ulen > skb->len)
875 		goto short_packet;
876 
877 	if (proto == IPPROTO_UDP) {
878 		/* UDP validates ulen. */
879 
880 		/* Check for jumbo payload */
881 		if (ulen == 0)
882 			ulen = skb->len;
883 
884 		if (ulen < sizeof(*uh))
885 			goto short_packet;
886 
887 		if (ulen < skb->len) {
888 			if (pskb_trim_rcsum(skb, ulen))
889 				goto short_packet;
890 			saddr = &ipv6_hdr(skb)->saddr;
891 			daddr = &ipv6_hdr(skb)->daddr;
892 			uh = udp_hdr(skb);
893 		}
894 	}
895 
896 	if (udp6_csum_init(skb, uh, proto))
897 		goto csum_error;
898 
899 	/* Check if the socket is already available, e.g. due to early demux */
900 	sk = skb_steal_sock(skb);
901 	if (sk) {
902 		struct dst_entry *dst = skb_dst(skb);
903 		int ret;
904 
905 		if (unlikely(rcu_dereference(sk->sk_rx_dst) != dst))
906 			udp6_sk_rx_dst_set(sk, dst);
907 
908 		if (!uh->check && !udp_sk(sk)->no_check6_rx) {
909 			sock_put(sk);
910 			goto report_csum_error;
911 		}
912 
913 		ret = udp6_unicast_rcv_skb(sk, skb, uh);
914 		sock_put(sk);
915 		return ret;
916 	}
917 
918 	/*
919 	 *	Multicast receive code
920 	 */
921 	if (ipv6_addr_is_multicast(daddr))
922 		return __udp6_lib_mcast_deliver(net, skb,
923 				saddr, daddr, udptable, proto);
924 
925 	/* Unicast */
926 	sk = __udp6_lib_lookup_skb(skb, uh->source, uh->dest, udptable);
927 	if (sk) {
928 		if (!uh->check && !udp_sk(sk)->no_check6_rx)
929 			goto report_csum_error;
930 		return udp6_unicast_rcv_skb(sk, skb, uh);
931 	}
932 
933 	if (!uh->check)
934 		goto report_csum_error;
935 
936 	if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
937 		goto discard;
938 
939 	if (udp_lib_checksum_complete(skb))
940 		goto csum_error;
941 
942 	__UDP6_INC_STATS(net, UDP_MIB_NOPORTS, proto == IPPROTO_UDPLITE);
943 	icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0);
944 
945 	kfree_skb(skb);
946 	return 0;
947 
948 short_packet:
949 	net_dbg_ratelimited("UDP%sv6: short packet: From [%pI6c]:%u %d/%d to [%pI6c]:%u\n",
950 			    proto == IPPROTO_UDPLITE ? "-Lite" : "",
951 			    saddr, ntohs(uh->source),
952 			    ulen, skb->len,
953 			    daddr, ntohs(uh->dest));
954 	goto discard;
955 
956 report_csum_error:
957 	udp6_csum_zero_error(skb);
958 csum_error:
959 	__UDP6_INC_STATS(net, UDP_MIB_CSUMERRORS, proto == IPPROTO_UDPLITE);
960 discard:
961 	__UDP6_INC_STATS(net, UDP_MIB_INERRORS, proto == IPPROTO_UDPLITE);
962 	kfree_skb(skb);
963 	return 0;
964 }
965 
966 
__udp6_lib_demux_lookup(struct net * net,__be16 loc_port,const struct in6_addr * loc_addr,__be16 rmt_port,const struct in6_addr * rmt_addr,int dif,int sdif)967 static struct sock *__udp6_lib_demux_lookup(struct net *net,
968 			__be16 loc_port, const struct in6_addr *loc_addr,
969 			__be16 rmt_port, const struct in6_addr *rmt_addr,
970 			int dif, int sdif)
971 {
972 	unsigned short hnum = ntohs(loc_port);
973 	unsigned int hash2 = ipv6_portaddr_hash(net, loc_addr, hnum);
974 	unsigned int slot2 = hash2 & udp_table.mask;
975 	struct udp_hslot *hslot2 = &udp_table.hash2[slot2];
976 	const __portpair ports = INET_COMBINED_PORTS(rmt_port, hnum);
977 	struct sock *sk;
978 
979 	udp_portaddr_for_each_entry_rcu(sk, &hslot2->head) {
980 		if (sk->sk_state == TCP_ESTABLISHED &&
981 		    INET6_MATCH(sk, net, rmt_addr, loc_addr, ports, dif, sdif))
982 			return sk;
983 		/* Only check first socket in chain */
984 		break;
985 	}
986 	return NULL;
987 }
988 
udp_v6_early_demux(struct sk_buff * skb)989 void udp_v6_early_demux(struct sk_buff *skb)
990 {
991 	struct net *net = dev_net(skb->dev);
992 	const struct udphdr *uh;
993 	struct sock *sk;
994 	struct dst_entry *dst;
995 	int dif = skb->dev->ifindex;
996 	int sdif = inet6_sdif(skb);
997 
998 	if (!pskb_may_pull(skb, skb_transport_offset(skb) +
999 	    sizeof(struct udphdr)))
1000 		return;
1001 
1002 	uh = udp_hdr(skb);
1003 
1004 	if (skb->pkt_type == PACKET_HOST)
1005 		sk = __udp6_lib_demux_lookup(net, uh->dest,
1006 					     &ipv6_hdr(skb)->daddr,
1007 					     uh->source, &ipv6_hdr(skb)->saddr,
1008 					     dif, sdif);
1009 	else
1010 		return;
1011 
1012 	if (!sk || !refcount_inc_not_zero(&sk->sk_refcnt))
1013 		return;
1014 
1015 	skb->sk = sk;
1016 	skb->destructor = sock_efree;
1017 	dst = rcu_dereference(sk->sk_rx_dst);
1018 
1019 	if (dst)
1020 		dst = dst_check(dst, inet6_sk(sk)->rx_dst_cookie);
1021 	if (dst) {
1022 		/* set noref for now.
1023 		 * any place which wants to hold dst has to call
1024 		 * dst_hold_safe()
1025 		 */
1026 		skb_dst_set_noref(skb, dst);
1027 	}
1028 }
1029 
udpv6_rcv(struct sk_buff * skb)1030 INDIRECT_CALLABLE_SCOPE int udpv6_rcv(struct sk_buff *skb)
1031 {
1032 	return __udp6_lib_rcv(skb, &udp_table, IPPROTO_UDP);
1033 }
1034 
1035 /*
1036  * Throw away all pending data and cancel the corking. Socket is locked.
1037  */
udp_v6_flush_pending_frames(struct sock * sk)1038 static void udp_v6_flush_pending_frames(struct sock *sk)
1039 {
1040 	struct udp_sock *up = udp_sk(sk);
1041 
1042 	if (up->pending == AF_INET)
1043 		udp_flush_pending_frames(sk);
1044 	else if (up->pending) {
1045 		up->len = 0;
1046 		up->pending = 0;
1047 		ip6_flush_pending_frames(sk);
1048 	}
1049 }
1050 
udpv6_pre_connect(struct sock * sk,struct sockaddr * uaddr,int addr_len)1051 static int udpv6_pre_connect(struct sock *sk, struct sockaddr *uaddr,
1052 			     int addr_len)
1053 {
1054 	if (addr_len < offsetofend(struct sockaddr, sa_family))
1055 		return -EINVAL;
1056 	/* The following checks are replicated from __ip6_datagram_connect()
1057 	 * and intended to prevent BPF program called below from accessing
1058 	 * bytes that are out of the bound specified by user in addr_len.
1059 	 */
1060 	if (uaddr->sa_family == AF_INET) {
1061 		if (__ipv6_only_sock(sk))
1062 			return -EAFNOSUPPORT;
1063 		return udp_pre_connect(sk, uaddr, addr_len);
1064 	}
1065 
1066 	if (addr_len < SIN6_LEN_RFC2133)
1067 		return -EINVAL;
1068 
1069 	return BPF_CGROUP_RUN_PROG_INET6_CONNECT_LOCK(sk, uaddr);
1070 }
1071 
1072 /**
1073  *	udp6_hwcsum_outgoing  -  handle outgoing HW checksumming
1074  *	@sk:	socket we are sending on
1075  *	@skb:	sk_buff containing the filled-in UDP header
1076  *		(checksum field must be zeroed out)
1077  */
udp6_hwcsum_outgoing(struct sock * sk,struct sk_buff * skb,const struct in6_addr * saddr,const struct in6_addr * daddr,int len)1078 static void udp6_hwcsum_outgoing(struct sock *sk, struct sk_buff *skb,
1079 				 const struct in6_addr *saddr,
1080 				 const struct in6_addr *daddr, int len)
1081 {
1082 	unsigned int offset;
1083 	struct udphdr *uh = udp_hdr(skb);
1084 	struct sk_buff *frags = skb_shinfo(skb)->frag_list;
1085 	__wsum csum = 0;
1086 
1087 	if (!frags) {
1088 		/* Only one fragment on the socket.  */
1089 		skb->csum_start = skb_transport_header(skb) - skb->head;
1090 		skb->csum_offset = offsetof(struct udphdr, check);
1091 		uh->check = ~csum_ipv6_magic(saddr, daddr, len, IPPROTO_UDP, 0);
1092 	} else {
1093 		/*
1094 		 * HW-checksum won't work as there are two or more
1095 		 * fragments on the socket so that all csums of sk_buffs
1096 		 * should be together
1097 		 */
1098 		offset = skb_transport_offset(skb);
1099 		skb->csum = skb_checksum(skb, offset, skb->len - offset, 0);
1100 		csum = skb->csum;
1101 
1102 		skb->ip_summed = CHECKSUM_NONE;
1103 
1104 		do {
1105 			csum = csum_add(csum, frags->csum);
1106 		} while ((frags = frags->next));
1107 
1108 		uh->check = csum_ipv6_magic(saddr, daddr, len, IPPROTO_UDP,
1109 					    csum);
1110 		if (uh->check == 0)
1111 			uh->check = CSUM_MANGLED_0;
1112 	}
1113 }
1114 
1115 /*
1116  *	Sending
1117  */
1118 
udp_v6_send_skb(struct sk_buff * skb,struct flowi6 * fl6,struct inet_cork * cork)1119 static int udp_v6_send_skb(struct sk_buff *skb, struct flowi6 *fl6,
1120 			   struct inet_cork *cork)
1121 {
1122 	struct sock *sk = skb->sk;
1123 	struct udphdr *uh;
1124 	int err = 0;
1125 	int is_udplite = IS_UDPLITE(sk);
1126 	__wsum csum = 0;
1127 	int offset = skb_transport_offset(skb);
1128 	int len = skb->len - offset;
1129 	int datalen = len - sizeof(*uh);
1130 
1131 	/*
1132 	 * Create a UDP header
1133 	 */
1134 	uh = udp_hdr(skb);
1135 	uh->source = fl6->fl6_sport;
1136 	uh->dest = fl6->fl6_dport;
1137 	uh->len = htons(len);
1138 	uh->check = 0;
1139 
1140 	if (cork->gso_size) {
1141 		const int hlen = skb_network_header_len(skb) +
1142 				 sizeof(struct udphdr);
1143 
1144 		if (hlen + cork->gso_size > cork->fragsize) {
1145 			kfree_skb(skb);
1146 			return -EINVAL;
1147 		}
1148 		if (datalen > cork->gso_size * UDP_MAX_SEGMENTS) {
1149 			kfree_skb(skb);
1150 			return -EINVAL;
1151 		}
1152 		if (udp_sk(sk)->no_check6_tx) {
1153 			kfree_skb(skb);
1154 			return -EINVAL;
1155 		}
1156 		if (skb->ip_summed != CHECKSUM_PARTIAL || is_udplite ||
1157 		    dst_xfrm(skb_dst(skb))) {
1158 			kfree_skb(skb);
1159 			return -EIO;
1160 		}
1161 
1162 		if (datalen > cork->gso_size) {
1163 			skb_shinfo(skb)->gso_size = cork->gso_size;
1164 			skb_shinfo(skb)->gso_type = SKB_GSO_UDP_L4;
1165 			skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(datalen,
1166 								 cork->gso_size);
1167 		}
1168 		goto csum_partial;
1169 	}
1170 
1171 	if (is_udplite)
1172 		csum = udplite_csum(skb);
1173 	else if (udp_sk(sk)->no_check6_tx) {   /* UDP csum disabled */
1174 		skb->ip_summed = CHECKSUM_NONE;
1175 		goto send;
1176 	} else if (skb->ip_summed == CHECKSUM_PARTIAL) { /* UDP hardware csum */
1177 csum_partial:
1178 		udp6_hwcsum_outgoing(sk, skb, &fl6->saddr, &fl6->daddr, len);
1179 		goto send;
1180 	} else
1181 		csum = udp_csum(skb);
1182 
1183 	/* add protocol-dependent pseudo-header */
1184 	uh->check = csum_ipv6_magic(&fl6->saddr, &fl6->daddr,
1185 				    len, fl6->flowi6_proto, csum);
1186 	if (uh->check == 0)
1187 		uh->check = CSUM_MANGLED_0;
1188 
1189 send:
1190 	err = ip6_send_skb(skb);
1191 	if (err) {
1192 		if (err == -ENOBUFS && !inet6_sk(sk)->recverr) {
1193 			UDP6_INC_STATS(sock_net(sk),
1194 				       UDP_MIB_SNDBUFERRORS, is_udplite);
1195 			err = 0;
1196 		}
1197 	} else {
1198 		UDP6_INC_STATS(sock_net(sk),
1199 			       UDP_MIB_OUTDATAGRAMS, is_udplite);
1200 	}
1201 	return err;
1202 }
1203 
udp_v6_push_pending_frames(struct sock * sk)1204 static int udp_v6_push_pending_frames(struct sock *sk)
1205 {
1206 	struct sk_buff *skb;
1207 	struct udp_sock  *up = udp_sk(sk);
1208 	struct flowi6 fl6;
1209 	int err = 0;
1210 
1211 	if (up->pending == AF_INET)
1212 		return udp_push_pending_frames(sk);
1213 
1214 	/* ip6_finish_skb will release the cork, so make a copy of
1215 	 * fl6 here.
1216 	 */
1217 	fl6 = inet_sk(sk)->cork.fl.u.ip6;
1218 
1219 	skb = ip6_finish_skb(sk);
1220 	if (!skb)
1221 		goto out;
1222 
1223 	err = udp_v6_send_skb(skb, &fl6, &inet_sk(sk)->cork.base);
1224 
1225 out:
1226 	up->len = 0;
1227 	up->pending = 0;
1228 	return err;
1229 }
1230 
udpv6_sendmsg(struct sock * sk,struct msghdr * msg,size_t len)1231 int udpv6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
1232 {
1233 	struct ipv6_txoptions opt_space;
1234 	struct udp_sock *up = udp_sk(sk);
1235 	struct inet_sock *inet = inet_sk(sk);
1236 	struct ipv6_pinfo *np = inet6_sk(sk);
1237 	DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name);
1238 	struct in6_addr *daddr, *final_p, final;
1239 	struct ipv6_txoptions *opt = NULL;
1240 	struct ipv6_txoptions *opt_to_free = NULL;
1241 	struct ip6_flowlabel *flowlabel = NULL;
1242 	struct flowi6 fl6;
1243 	struct dst_entry *dst;
1244 	struct ipcm6_cookie ipc6;
1245 	int addr_len = msg->msg_namelen;
1246 	bool connected = false;
1247 	int ulen = len;
1248 	int corkreq = READ_ONCE(up->corkflag) || msg->msg_flags&MSG_MORE;
1249 	int err;
1250 	int is_udplite = IS_UDPLITE(sk);
1251 	int (*getfrag)(void *, char *, int, int, int, struct sk_buff *);
1252 
1253 	ipcm6_init(&ipc6);
1254 	ipc6.gso_size = READ_ONCE(up->gso_size);
1255 	ipc6.sockc.tsflags = sk->sk_tsflags;
1256 	ipc6.sockc.mark = sk->sk_mark;
1257 
1258 	/* destination address check */
1259 	if (sin6) {
1260 		if (addr_len < offsetof(struct sockaddr, sa_data))
1261 			return -EINVAL;
1262 
1263 		switch (sin6->sin6_family) {
1264 		case AF_INET6:
1265 			if (addr_len < SIN6_LEN_RFC2133)
1266 				return -EINVAL;
1267 			daddr = &sin6->sin6_addr;
1268 			if (ipv6_addr_any(daddr) &&
1269 			    ipv6_addr_v4mapped(&np->saddr))
1270 				ipv6_addr_set_v4mapped(htonl(INADDR_LOOPBACK),
1271 						       daddr);
1272 			break;
1273 		case AF_INET:
1274 			goto do_udp_sendmsg;
1275 		case AF_UNSPEC:
1276 			msg->msg_name = sin6 = NULL;
1277 			msg->msg_namelen = addr_len = 0;
1278 			daddr = NULL;
1279 			break;
1280 		default:
1281 			return -EINVAL;
1282 		}
1283 	} else if (!up->pending) {
1284 		if (sk->sk_state != TCP_ESTABLISHED)
1285 			return -EDESTADDRREQ;
1286 		daddr = &sk->sk_v6_daddr;
1287 	} else
1288 		daddr = NULL;
1289 
1290 	if (daddr) {
1291 		if (ipv6_addr_v4mapped(daddr)) {
1292 			struct sockaddr_in sin;
1293 			sin.sin_family = AF_INET;
1294 			sin.sin_port = sin6 ? sin6->sin6_port : inet->inet_dport;
1295 			sin.sin_addr.s_addr = daddr->s6_addr32[3];
1296 			msg->msg_name = &sin;
1297 			msg->msg_namelen = sizeof(sin);
1298 do_udp_sendmsg:
1299 			err = __ipv6_only_sock(sk) ?
1300 				-ENETUNREACH : udp_sendmsg(sk, msg, len);
1301 			msg->msg_name = sin6;
1302 			msg->msg_namelen = addr_len;
1303 			return err;
1304 		}
1305 	}
1306 
1307 	if (up->pending == AF_INET)
1308 		return udp_sendmsg(sk, msg, len);
1309 
1310 	/* Rough check on arithmetic overflow,
1311 	   better check is made in ip6_append_data().
1312 	   */
1313 	if (len > INT_MAX - sizeof(struct udphdr))
1314 		return -EMSGSIZE;
1315 
1316 	getfrag  =  is_udplite ?  udplite_getfrag : ip_generic_getfrag;
1317 	if (up->pending) {
1318 		/*
1319 		 * There are pending frames.
1320 		 * The socket lock must be held while it's corked.
1321 		 */
1322 		lock_sock(sk);
1323 		if (likely(up->pending)) {
1324 			if (unlikely(up->pending != AF_INET6)) {
1325 				release_sock(sk);
1326 				return -EAFNOSUPPORT;
1327 			}
1328 			dst = NULL;
1329 			goto do_append_data;
1330 		}
1331 		release_sock(sk);
1332 	}
1333 	ulen += sizeof(struct udphdr);
1334 
1335 	memset(&fl6, 0, sizeof(fl6));
1336 
1337 	if (sin6) {
1338 		if (sin6->sin6_port == 0)
1339 			return -EINVAL;
1340 
1341 		fl6.fl6_dport = sin6->sin6_port;
1342 		daddr = &sin6->sin6_addr;
1343 
1344 		if (np->sndflow) {
1345 			fl6.flowlabel = sin6->sin6_flowinfo&IPV6_FLOWINFO_MASK;
1346 			if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) {
1347 				flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
1348 				if (IS_ERR(flowlabel))
1349 					return -EINVAL;
1350 			}
1351 		}
1352 
1353 		/*
1354 		 * Otherwise it will be difficult to maintain
1355 		 * sk->sk_dst_cache.
1356 		 */
1357 		if (sk->sk_state == TCP_ESTABLISHED &&
1358 		    ipv6_addr_equal(daddr, &sk->sk_v6_daddr))
1359 			daddr = &sk->sk_v6_daddr;
1360 
1361 		if (addr_len >= sizeof(struct sockaddr_in6) &&
1362 		    sin6->sin6_scope_id &&
1363 		    __ipv6_addr_needs_scope_id(__ipv6_addr_type(daddr)))
1364 			fl6.flowi6_oif = sin6->sin6_scope_id;
1365 	} else {
1366 		if (sk->sk_state != TCP_ESTABLISHED)
1367 			return -EDESTADDRREQ;
1368 
1369 		fl6.fl6_dport = inet->inet_dport;
1370 		daddr = &sk->sk_v6_daddr;
1371 		fl6.flowlabel = np->flow_label;
1372 		connected = true;
1373 	}
1374 
1375 	if (!fl6.flowi6_oif)
1376 		fl6.flowi6_oif = sk->sk_bound_dev_if;
1377 
1378 	if (!fl6.flowi6_oif)
1379 		fl6.flowi6_oif = np->sticky_pktinfo.ipi6_ifindex;
1380 
1381 	fl6.flowi6_uid = sk->sk_uid;
1382 
1383 	if (msg->msg_controllen) {
1384 		opt = &opt_space;
1385 		memset(opt, 0, sizeof(struct ipv6_txoptions));
1386 		opt->tot_len = sizeof(*opt);
1387 		ipc6.opt = opt;
1388 
1389 		err = udp_cmsg_send(sk, msg, &ipc6.gso_size);
1390 		if (err > 0)
1391 			err = ip6_datagram_send_ctl(sock_net(sk), sk, msg, &fl6,
1392 						    &ipc6);
1393 		if (err < 0) {
1394 			fl6_sock_release(flowlabel);
1395 			return err;
1396 		}
1397 		if ((fl6.flowlabel&IPV6_FLOWLABEL_MASK) && !flowlabel) {
1398 			flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
1399 			if (IS_ERR(flowlabel))
1400 				return -EINVAL;
1401 		}
1402 		if (!(opt->opt_nflen|opt->opt_flen))
1403 			opt = NULL;
1404 		connected = false;
1405 	}
1406 	if (!opt) {
1407 		opt = txopt_get(np);
1408 		opt_to_free = opt;
1409 	}
1410 	if (flowlabel)
1411 		opt = fl6_merge_options(&opt_space, flowlabel, opt);
1412 	opt = ipv6_fixup_options(&opt_space, opt);
1413 	ipc6.opt = opt;
1414 
1415 	fl6.flowi6_proto = sk->sk_protocol;
1416 	fl6.flowi6_mark = ipc6.sockc.mark;
1417 	fl6.daddr = *daddr;
1418 	if (ipv6_addr_any(&fl6.saddr) && !ipv6_addr_any(&np->saddr))
1419 		fl6.saddr = np->saddr;
1420 	fl6.fl6_sport = inet->inet_sport;
1421 
1422 	if (cgroup_bpf_enabled && !connected) {
1423 		err = BPF_CGROUP_RUN_PROG_UDP6_SENDMSG_LOCK(sk,
1424 					   (struct sockaddr *)sin6, &fl6.saddr);
1425 		if (err)
1426 			goto out_no_dst;
1427 		if (sin6) {
1428 			if (ipv6_addr_v4mapped(&sin6->sin6_addr)) {
1429 				/* BPF program rewrote IPv6-only by IPv4-mapped
1430 				 * IPv6. It's currently unsupported.
1431 				 */
1432 				err = -ENOTSUPP;
1433 				goto out_no_dst;
1434 			}
1435 			if (sin6->sin6_port == 0) {
1436 				/* BPF program set invalid port. Reject it. */
1437 				err = -EINVAL;
1438 				goto out_no_dst;
1439 			}
1440 			fl6.fl6_dport = sin6->sin6_port;
1441 			fl6.daddr = sin6->sin6_addr;
1442 		}
1443 	}
1444 
1445 	if (ipv6_addr_any(&fl6.daddr))
1446 		fl6.daddr.s6_addr[15] = 0x1; /* :: means loopback (BSD'ism) */
1447 
1448 	final_p = fl6_update_dst(&fl6, opt, &final);
1449 	if (final_p)
1450 		connected = false;
1451 
1452 	if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr)) {
1453 		fl6.flowi6_oif = np->mcast_oif;
1454 		connected = false;
1455 	} else if (!fl6.flowi6_oif)
1456 		fl6.flowi6_oif = np->ucast_oif;
1457 
1458 	security_sk_classify_flow(sk, flowi6_to_flowi(&fl6));
1459 
1460 	if (ipc6.tclass < 0)
1461 		ipc6.tclass = np->tclass;
1462 
1463 	fl6.flowlabel = ip6_make_flowinfo(ipc6.tclass, fl6.flowlabel);
1464 
1465 	dst = ip6_sk_dst_lookup_flow(sk, &fl6, final_p, connected);
1466 	if (IS_ERR(dst)) {
1467 		err = PTR_ERR(dst);
1468 		dst = NULL;
1469 		goto out;
1470 	}
1471 
1472 	if (ipc6.hlimit < 0)
1473 		ipc6.hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst);
1474 
1475 	if (msg->msg_flags&MSG_CONFIRM)
1476 		goto do_confirm;
1477 back_from_confirm:
1478 
1479 	/* Lockless fast path for the non-corking case */
1480 	if (!corkreq) {
1481 		struct inet_cork_full cork;
1482 		struct sk_buff *skb;
1483 
1484 		skb = ip6_make_skb(sk, getfrag, msg, ulen,
1485 				   sizeof(struct udphdr), &ipc6,
1486 				   &fl6, (struct rt6_info *)dst,
1487 				   msg->msg_flags, &cork);
1488 		err = PTR_ERR(skb);
1489 		if (!IS_ERR_OR_NULL(skb))
1490 			err = udp_v6_send_skb(skb, &fl6, &cork.base);
1491 		goto out;
1492 	}
1493 
1494 	lock_sock(sk);
1495 	if (unlikely(up->pending)) {
1496 		/* The socket is already corked while preparing it. */
1497 		/* ... which is an evident application bug. --ANK */
1498 		release_sock(sk);
1499 
1500 		net_dbg_ratelimited("udp cork app bug 2\n");
1501 		err = -EINVAL;
1502 		goto out;
1503 	}
1504 
1505 	up->pending = AF_INET6;
1506 
1507 do_append_data:
1508 	if (ipc6.dontfrag < 0)
1509 		ipc6.dontfrag = np->dontfrag;
1510 	up->len += ulen;
1511 	err = ip6_append_data(sk, getfrag, msg, ulen, sizeof(struct udphdr),
1512 			      &ipc6, &fl6, (struct rt6_info *)dst,
1513 			      corkreq ? msg->msg_flags|MSG_MORE : msg->msg_flags);
1514 	if (err)
1515 		udp_v6_flush_pending_frames(sk);
1516 	else if (!corkreq)
1517 		err = udp_v6_push_pending_frames(sk);
1518 	else if (unlikely(skb_queue_empty(&sk->sk_write_queue)))
1519 		up->pending = 0;
1520 
1521 	if (err > 0)
1522 		err = np->recverr ? net_xmit_errno(err) : 0;
1523 	release_sock(sk);
1524 
1525 out:
1526 	dst_release(dst);
1527 out_no_dst:
1528 	fl6_sock_release(flowlabel);
1529 	txopt_put(opt_to_free);
1530 	if (!err)
1531 		return len;
1532 	/*
1533 	 * ENOBUFS = no kernel mem, SOCK_NOSPACE = no sndbuf space.  Reporting
1534 	 * ENOBUFS might not be good (it's not tunable per se), but otherwise
1535 	 * we don't have a good statistic (IpOutDiscards but it can be too many
1536 	 * things).  We could add another new stat but at least for now that
1537 	 * seems like overkill.
1538 	 */
1539 	if (err == -ENOBUFS || test_bit(SOCK_NOSPACE, &sk->sk_socket->flags)) {
1540 		UDP6_INC_STATS(sock_net(sk),
1541 			       UDP_MIB_SNDBUFERRORS, is_udplite);
1542 	}
1543 	return err;
1544 
1545 do_confirm:
1546 	if (msg->msg_flags & MSG_PROBE)
1547 		dst_confirm_neigh(dst, &fl6.daddr);
1548 	if (!(msg->msg_flags&MSG_PROBE) || len)
1549 		goto back_from_confirm;
1550 	err = 0;
1551 	goto out;
1552 }
1553 
udpv6_destroy_sock(struct sock * sk)1554 void udpv6_destroy_sock(struct sock *sk)
1555 {
1556 	struct udp_sock *up = udp_sk(sk);
1557 	lock_sock(sk);
1558 
1559 	/* protects from races with udp_abort() */
1560 	sock_set_flag(sk, SOCK_DEAD);
1561 	udp_v6_flush_pending_frames(sk);
1562 	release_sock(sk);
1563 
1564 	if (static_branch_unlikely(&udpv6_encap_needed_key)) {
1565 		if (up->encap_type) {
1566 			void (*encap_destroy)(struct sock *sk);
1567 			encap_destroy = READ_ONCE(up->encap_destroy);
1568 			if (encap_destroy)
1569 				encap_destroy(sk);
1570 		}
1571 		if (up->encap_enabled) {
1572 			static_branch_dec(&udpv6_encap_needed_key);
1573 			udp_encap_disable();
1574 		}
1575 	}
1576 }
1577 
1578 /*
1579  *	Socket option code for UDP
1580  */
udpv6_setsockopt(struct sock * sk,int level,int optname,char __user * optval,unsigned int optlen)1581 int udpv6_setsockopt(struct sock *sk, int level, int optname,
1582 		     char __user *optval, unsigned int optlen)
1583 {
1584 	if (level == SOL_UDP  ||  level == SOL_UDPLITE)
1585 		return udp_lib_setsockopt(sk, level, optname, optval, optlen,
1586 					  udp_v6_push_pending_frames);
1587 	return ipv6_setsockopt(sk, level, optname, optval, optlen);
1588 }
1589 
1590 #ifdef CONFIG_COMPAT
compat_udpv6_setsockopt(struct sock * sk,int level,int optname,char __user * optval,unsigned int optlen)1591 int compat_udpv6_setsockopt(struct sock *sk, int level, int optname,
1592 			    char __user *optval, unsigned int optlen)
1593 {
1594 	if (level == SOL_UDP  ||  level == SOL_UDPLITE)
1595 		return udp_lib_setsockopt(sk, level, optname, optval, optlen,
1596 					  udp_v6_push_pending_frames);
1597 	return compat_ipv6_setsockopt(sk, level, optname, optval, optlen);
1598 }
1599 #endif
1600 
udpv6_getsockopt(struct sock * sk,int level,int optname,char __user * optval,int __user * optlen)1601 int udpv6_getsockopt(struct sock *sk, int level, int optname,
1602 		     char __user *optval, int __user *optlen)
1603 {
1604 	if (level == SOL_UDP  ||  level == SOL_UDPLITE)
1605 		return udp_lib_getsockopt(sk, level, optname, optval, optlen);
1606 	return ipv6_getsockopt(sk, level, optname, optval, optlen);
1607 }
1608 
1609 #ifdef CONFIG_COMPAT
compat_udpv6_getsockopt(struct sock * sk,int level,int optname,char __user * optval,int __user * optlen)1610 int compat_udpv6_getsockopt(struct sock *sk, int level, int optname,
1611 			    char __user *optval, int __user *optlen)
1612 {
1613 	if (level == SOL_UDP  ||  level == SOL_UDPLITE)
1614 		return udp_lib_getsockopt(sk, level, optname, optval, optlen);
1615 	return compat_ipv6_getsockopt(sk, level, optname, optval, optlen);
1616 }
1617 #endif
1618 
1619 static const struct inet6_protocol udpv6_protocol = {
1620 	.handler	=	udpv6_rcv,
1621 	.err_handler	=	udpv6_err,
1622 	.flags		=	INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
1623 };
1624 
1625 /* ------------------------------------------------------------------------ */
1626 #ifdef CONFIG_PROC_FS
udp6_seq_show(struct seq_file * seq,void * v)1627 int udp6_seq_show(struct seq_file *seq, void *v)
1628 {
1629 	if (v == SEQ_START_TOKEN) {
1630 		seq_puts(seq, IPV6_SEQ_DGRAM_HEADER);
1631 	} else {
1632 		int bucket = ((struct udp_iter_state *)seq->private)->bucket;
1633 		struct inet_sock *inet = inet_sk(v);
1634 		__u16 srcp = ntohs(inet->inet_sport);
1635 		__u16 destp = ntohs(inet->inet_dport);
1636 		__ip6_dgram_sock_seq_show(seq, v, srcp, destp,
1637 					  udp_rqueue_get(v), bucket);
1638 	}
1639 	return 0;
1640 }
1641 
1642 const struct seq_operations udp6_seq_ops = {
1643 	.start		= udp_seq_start,
1644 	.next		= udp_seq_next,
1645 	.stop		= udp_seq_stop,
1646 	.show		= udp6_seq_show,
1647 };
1648 EXPORT_SYMBOL(udp6_seq_ops);
1649 
1650 static struct udp_seq_afinfo udp6_seq_afinfo = {
1651 	.family		= AF_INET6,
1652 	.udp_table	= &udp_table,
1653 };
1654 
udp6_proc_init(struct net * net)1655 int __net_init udp6_proc_init(struct net *net)
1656 {
1657 	if (!proc_create_net_data("udp6", 0444, net->proc_net, &udp6_seq_ops,
1658 			sizeof(struct udp_iter_state), &udp6_seq_afinfo))
1659 		return -ENOMEM;
1660 	return 0;
1661 }
1662 
udp6_proc_exit(struct net * net)1663 void udp6_proc_exit(struct net *net)
1664 {
1665 	remove_proc_entry("udp6", net->proc_net);
1666 }
1667 #endif /* CONFIG_PROC_FS */
1668 
1669 /* ------------------------------------------------------------------------ */
1670 
1671 struct proto udpv6_prot = {
1672 	.name			= "UDPv6",
1673 	.owner			= THIS_MODULE,
1674 	.close			= udp_lib_close,
1675 	.pre_connect		= udpv6_pre_connect,
1676 	.connect		= ip6_datagram_connect,
1677 	.disconnect		= udp_disconnect,
1678 	.ioctl			= udp_ioctl,
1679 	.init			= udpv6_init_sock,
1680 	.destroy		= udpv6_destroy_sock,
1681 	.setsockopt		= udpv6_setsockopt,
1682 	.getsockopt		= udpv6_getsockopt,
1683 	.sendmsg		= udpv6_sendmsg,
1684 	.recvmsg		= udpv6_recvmsg,
1685 	.release_cb		= ip6_datagram_release_cb,
1686 	.hash			= udp_lib_hash,
1687 	.unhash			= udp_lib_unhash,
1688 	.rehash			= udp_v6_rehash,
1689 	.get_port		= udp_v6_get_port,
1690 	.memory_allocated	= &udp_memory_allocated,
1691 	.sysctl_mem		= sysctl_udp_mem,
1692 	.sysctl_wmem_offset     = offsetof(struct net, ipv4.sysctl_udp_wmem_min),
1693 	.sysctl_rmem_offset     = offsetof(struct net, ipv4.sysctl_udp_rmem_min),
1694 	.obj_size		= sizeof(struct udp6_sock),
1695 	.h.udp_table		= &udp_table,
1696 #ifdef CONFIG_COMPAT
1697 	.compat_setsockopt	= compat_udpv6_setsockopt,
1698 	.compat_getsockopt	= compat_udpv6_getsockopt,
1699 #endif
1700 	.diag_destroy		= udp_abort,
1701 };
1702 
1703 static struct inet_protosw udpv6_protosw = {
1704 	.type =      SOCK_DGRAM,
1705 	.protocol =  IPPROTO_UDP,
1706 	.prot =      &udpv6_prot,
1707 	.ops =       &inet6_dgram_ops,
1708 	.flags =     INET_PROTOSW_PERMANENT,
1709 };
1710 
udpv6_init(void)1711 int __init udpv6_init(void)
1712 {
1713 	int ret;
1714 
1715 	ret = inet6_add_protocol(&udpv6_protocol, IPPROTO_UDP);
1716 	if (ret)
1717 		goto out;
1718 
1719 	ret = inet6_register_protosw(&udpv6_protosw);
1720 	if (ret)
1721 		goto out_udpv6_protocol;
1722 out:
1723 	return ret;
1724 
1725 out_udpv6_protocol:
1726 	inet6_del_protocol(&udpv6_protocol, IPPROTO_UDP);
1727 	goto out;
1728 }
1729 
udpv6_exit(void)1730 void udpv6_exit(void)
1731 {
1732 	inet6_unregister_protosw(&udpv6_protosw);
1733 	inet6_del_protocol(&udpv6_protocol, IPPROTO_UDP);
1734 }
1735