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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/bpf-cgroup.h>
21 #include <linux/errno.h>
22 #include <linux/types.h>
23 #include <linux/socket.h>
24 #include <linux/sockios.h>
25 #include <linux/net.h>
26 #include <linux/in6.h>
27 #include <linux/netdevice.h>
28 #include <linux/if_arp.h>
29 #include <linux/ipv6.h>
30 #include <linux/icmpv6.h>
31 #include <linux/init.h>
32 #include <linux/module.h>
33 #include <linux/skbuff.h>
34 #include <linux/slab.h>
35 #include <linux/uaccess.h>
36 #include <linux/indirect_call_wrapper.h>
37 
38 #include <net/addrconf.h>
39 #include <net/ndisc.h>
40 #include <net/protocol.h>
41 #include <net/transp_v6.h>
42 #include <net/ip6_route.h>
43 #include <net/raw.h>
44 #include <net/seg6.h>
45 #include <net/tcp_states.h>
46 #include <net/ip6_checksum.h>
47 #include <net/ip6_tunnel.h>
48 #include <trace/events/udp.h>
49 #include <net/xfrm.h>
50 #include <net/inet_hashtables.h>
51 #include <net/inet6_hashtables.h>
52 #include <net/busy_poll.h>
53 #include <net/sock_reuseport.h>
54 #include <net/gro.h>
55 
56 #include <linux/proc_fs.h>
57 #include <linux/seq_file.h>
58 #include <trace/events/skb.h>
59 #include "udp_impl.h"
60 
udpv6_destruct_sock(struct sock * sk)61 static void udpv6_destruct_sock(struct sock *sk)
62 {
63 	udp_destruct_common(sk);
64 	inet6_sock_destruct(sk);
65 }
66 
udpv6_init_sock(struct sock * sk)67 int udpv6_init_sock(struct sock *sk)
68 {
69 	udp_lib_init_sock(sk);
70 	sk->sk_destruct = udpv6_destruct_sock;
71 	set_bit(SOCK_SUPPORT_ZC, &sk->sk_socket->flags);
72 	return 0;
73 }
74 
75 INDIRECT_CALLABLE_SCOPE
udp6_ehashfn(const struct net * net,const struct in6_addr * laddr,const u16 lport,const struct in6_addr * faddr,const __be16 fport)76 u32 udp6_ehashfn(const struct net *net,
77 		 const struct in6_addr *laddr,
78 		 const u16 lport,
79 		 const struct in6_addr *faddr,
80 		 const __be16 fport)
81 {
82 	static u32 udp6_ehash_secret __read_mostly;
83 	static u32 udp_ipv6_hash_secret __read_mostly;
84 
85 	u32 lhash, fhash;
86 
87 	net_get_random_once(&udp6_ehash_secret,
88 			    sizeof(udp6_ehash_secret));
89 	net_get_random_once(&udp_ipv6_hash_secret,
90 			    sizeof(udp_ipv6_hash_secret));
91 
92 	lhash = (__force u32)laddr->s6_addr32[3];
93 	fhash = __ipv6_addr_jhash(faddr, udp_ipv6_hash_secret);
94 
95 	return __inet6_ehashfn(lhash, lport, fhash, fport,
96 			       udp6_ehash_secret + net_hash_mix(net));
97 }
98 
udp_v6_get_port(struct sock * sk,unsigned short snum)99 int udp_v6_get_port(struct sock *sk, unsigned short snum)
100 {
101 	unsigned int hash2_nulladdr =
102 		ipv6_portaddr_hash(sock_net(sk), &in6addr_any, snum);
103 	unsigned int hash2_partial =
104 		ipv6_portaddr_hash(sock_net(sk), &sk->sk_v6_rcv_saddr, 0);
105 
106 	/* precompute partial secondary hash */
107 	udp_sk(sk)->udp_portaddr_hash = hash2_partial;
108 	return udp_lib_get_port(sk, snum, hash2_nulladdr);
109 }
110 
udp_v6_rehash(struct sock * sk)111 void udp_v6_rehash(struct sock *sk)
112 {
113 	u16 new_hash = ipv6_portaddr_hash(sock_net(sk),
114 					  &sk->sk_v6_rcv_saddr,
115 					  inet_sk(sk)->inet_num);
116 
117 	udp_lib_rehash(sk, new_hash);
118 }
119 
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)120 static int compute_score(struct sock *sk, struct net *net,
121 			 const struct in6_addr *saddr, __be16 sport,
122 			 const struct in6_addr *daddr, unsigned short hnum,
123 			 int dif, int sdif)
124 {
125 	int bound_dev_if, score;
126 	struct inet_sock *inet;
127 	bool dev_match;
128 
129 	if (!net_eq(sock_net(sk), net) ||
130 	    udp_sk(sk)->udp_port_hash != hnum ||
131 	    sk->sk_family != PF_INET6)
132 		return -1;
133 
134 	if (!ipv6_addr_equal(&sk->sk_v6_rcv_saddr, daddr))
135 		return -1;
136 
137 	score = 0;
138 	inet = inet_sk(sk);
139 
140 	if (inet->inet_dport) {
141 		if (inet->inet_dport != sport)
142 			return -1;
143 		score++;
144 	}
145 
146 	if (!ipv6_addr_any(&sk->sk_v6_daddr)) {
147 		if (!ipv6_addr_equal(&sk->sk_v6_daddr, saddr))
148 			return -1;
149 		score++;
150 	}
151 
152 	bound_dev_if = READ_ONCE(sk->sk_bound_dev_if);
153 	dev_match = udp_sk_bound_dev_eq(net, bound_dev_if, dif, sdif);
154 	if (!dev_match)
155 		return -1;
156 	if (bound_dev_if)
157 		score++;
158 
159 	if (READ_ONCE(sk->sk_incoming_cpu) == raw_smp_processor_id())
160 		score++;
161 
162 	return score;
163 }
164 
165 /**
166  * udp6_lib_lookup1() - Simplified lookup using primary hash (destination port)
167  * @net:	Network namespace
168  * @saddr:	Source address, network order
169  * @sport:	Source port, network order
170  * @daddr:	Destination address, network order
171  * @hnum:	Destination port, host order
172  * @dif:	Destination interface index
173  * @sdif:	Destination bridge port index, if relevant
174  * @udptable:	Set of UDP hash tables
175  *
176  * Simplified lookup to be used as fallback if no sockets are found due to a
177  * potential race between (receive) address change, and lookup happening before
178  * the rehash operation. This function ignores SO_REUSEPORT groups while scoring
179  * result sockets, because if we have one, we don't need the fallback at all.
180  *
181  * Called under rcu_read_lock().
182  *
183  * Return: socket with highest matching score if any, NULL if none
184  */
udp6_lib_lookup1(const struct net * net,const struct in6_addr * saddr,__be16 sport,const struct in6_addr * daddr,unsigned int hnum,int dif,int sdif,const struct udp_table * udptable)185 static struct sock *udp6_lib_lookup1(const struct net *net,
186 				     const struct in6_addr *saddr, __be16 sport,
187 				     const struct in6_addr *daddr,
188 				     unsigned int hnum, int dif, int sdif,
189 				     const struct udp_table *udptable)
190 {
191 	unsigned int slot = udp_hashfn(net, hnum, udptable->mask);
192 	struct udp_hslot *hslot = &udptable->hash[slot];
193 	struct sock *sk, *result = NULL;
194 	int score, badness = 0;
195 
196 	sk_for_each_rcu(sk, &hslot->head) {
197 		score = compute_score(sk, (struct net *)net,
198 				      (struct in6_addr *)saddr, sport,
199 				      (struct in6_addr *)daddr, hnum,
200 				      dif, sdif);
201 		if (score > badness) {
202 			result = sk;
203 			badness = score;
204 		}
205 	}
206 
207 	return result;
208 }
209 
210 /* 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)211 static struct sock *udp6_lib_lookup2(struct net *net,
212 		const struct in6_addr *saddr, __be16 sport,
213 		const struct in6_addr *daddr, unsigned int hnum,
214 		int dif, int sdif, struct udp_hslot *hslot2,
215 		struct sk_buff *skb)
216 {
217 	struct sock *sk, *result;
218 	int score, badness;
219 	bool need_rescore;
220 
221 	result = NULL;
222 	badness = -1;
223 	udp_portaddr_for_each_entry_rcu(sk, &hslot2->head) {
224 		need_rescore = false;
225 rescore:
226 		score = compute_score(need_rescore ? result : sk, net, saddr,
227 				      sport, daddr, hnum, dif, sdif);
228 		if (score > badness) {
229 			badness = score;
230 
231 			if (need_rescore)
232 				continue;
233 
234 			if (sk->sk_state == TCP_ESTABLISHED) {
235 				result = sk;
236 				continue;
237 			}
238 
239 			result = inet6_lookup_reuseport(net, sk, skb, sizeof(struct udphdr),
240 							saddr, sport, daddr, hnum, udp6_ehashfn);
241 			if (!result) {
242 				result = sk;
243 				continue;
244 			}
245 
246 			/* Fall back to scoring if group has connections */
247 			if (!reuseport_has_conns(sk))
248 				return result;
249 
250 			/* Reuseport logic returned an error, keep original score. */
251 			if (IS_ERR(result))
252 				continue;
253 
254 			/* compute_score is too long of a function to be
255 			 * inlined, and calling it again here yields
256 			 * measureable overhead for some
257 			 * workloads. Work around it by jumping
258 			 * backwards to rescore 'result'.
259 			 */
260 			need_rescore = true;
261 			goto rescore;
262 		}
263 	}
264 	return result;
265 }
266 
267 /* 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)268 struct sock *__udp6_lib_lookup(struct net *net,
269 			       const struct in6_addr *saddr, __be16 sport,
270 			       const struct in6_addr *daddr, __be16 dport,
271 			       int dif, int sdif, struct udp_table *udptable,
272 			       struct sk_buff *skb)
273 {
274 	unsigned short hnum = ntohs(dport);
275 	unsigned int hash2, slot2;
276 	struct udp_hslot *hslot2;
277 	struct sock *result, *sk;
278 
279 	hash2 = ipv6_portaddr_hash(net, daddr, hnum);
280 	slot2 = hash2 & udptable->mask;
281 	hslot2 = &udptable->hash2[slot2];
282 
283 	/* Lookup connected or non-wildcard sockets */
284 	result = udp6_lib_lookup2(net, saddr, sport,
285 				  daddr, hnum, dif, sdif,
286 				  hslot2, skb);
287 	if (!IS_ERR_OR_NULL(result) && result->sk_state == TCP_ESTABLISHED)
288 		goto done;
289 
290 	/* Lookup redirect from BPF */
291 	if (static_branch_unlikely(&bpf_sk_lookup_enabled) &&
292 	    udptable == net->ipv4.udp_table) {
293 		sk = inet6_lookup_run_sk_lookup(net, IPPROTO_UDP, skb, sizeof(struct udphdr),
294 						saddr, sport, daddr, hnum, dif,
295 						udp6_ehashfn);
296 		if (sk) {
297 			result = sk;
298 			goto done;
299 		}
300 	}
301 
302 	/* Got non-wildcard socket or error on first lookup */
303 	if (result)
304 		goto done;
305 
306 	/* Lookup wildcard sockets */
307 	hash2 = ipv6_portaddr_hash(net, &in6addr_any, hnum);
308 	slot2 = hash2 & udptable->mask;
309 	hslot2 = &udptable->hash2[slot2];
310 
311 	result = udp6_lib_lookup2(net, saddr, sport,
312 				  &in6addr_any, hnum, dif, sdif,
313 				  hslot2, skb);
314 	if (!IS_ERR_OR_NULL(result))
315 		goto done;
316 
317 	/* Cover address change/lookup/rehash race: see __udp4_lib_lookup() */
318 	result = udp6_lib_lookup1(net, saddr, sport, daddr, hnum, dif, sdif,
319 				  udptable);
320 
321 done:
322 	if (IS_ERR(result))
323 		return NULL;
324 	return result;
325 }
326 EXPORT_SYMBOL_GPL(__udp6_lib_lookup);
327 
__udp6_lib_lookup_skb(struct sk_buff * skb,__be16 sport,__be16 dport,struct udp_table * udptable)328 static struct sock *__udp6_lib_lookup_skb(struct sk_buff *skb,
329 					  __be16 sport, __be16 dport,
330 					  struct udp_table *udptable)
331 {
332 	const struct ipv6hdr *iph = ipv6_hdr(skb);
333 
334 	return __udp6_lib_lookup(dev_net(skb->dev), &iph->saddr, sport,
335 				 &iph->daddr, dport, inet6_iif(skb),
336 				 inet6_sdif(skb), udptable, skb);
337 }
338 
udp6_lib_lookup_skb(const struct sk_buff * skb,__be16 sport,__be16 dport)339 struct sock *udp6_lib_lookup_skb(const struct sk_buff *skb,
340 				 __be16 sport, __be16 dport)
341 {
342 	const u16 offset = NAPI_GRO_CB(skb)->network_offsets[skb->encapsulation];
343 	const struct ipv6hdr *iph = (struct ipv6hdr *)(skb->data + offset);
344 	struct net *net = dev_net(skb->dev);
345 	int iif, sdif;
346 
347 	inet6_get_iif_sdif(skb, &iif, &sdif);
348 
349 	return __udp6_lib_lookup(net, &iph->saddr, sport,
350 				 &iph->daddr, dport, iif,
351 				 sdif, net->ipv4.udp_table, NULL);
352 }
353 
354 /* Must be called under rcu_read_lock().
355  * Does increment socket refcount.
356  */
357 #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)358 struct sock *udp6_lib_lookup(struct net *net, const struct in6_addr *saddr, __be16 sport,
359 			     const struct in6_addr *daddr, __be16 dport, int dif)
360 {
361 	struct sock *sk;
362 
363 	sk =  __udp6_lib_lookup(net, saddr, sport, daddr, dport,
364 				dif, 0, net->ipv4.udp_table, NULL);
365 	if (sk && !refcount_inc_not_zero(&sk->sk_refcnt))
366 		sk = NULL;
367 	return sk;
368 }
369 EXPORT_SYMBOL_GPL(udp6_lib_lookup);
370 #endif
371 
372 /* do not use the scratch area len for jumbogram: their length execeeds the
373  * scratch area space; note that the IP6CB flags is still in the first
374  * cacheline, so checking for jumbograms is cheap
375  */
udp6_skb_len(struct sk_buff * skb)376 static int udp6_skb_len(struct sk_buff *skb)
377 {
378 	return unlikely(inet6_is_jumbogram(skb)) ? skb->len : udp_skb_len(skb);
379 }
380 
381 /*
382  *	This should be easy, if there is something there we
383  *	return it, otherwise we block.
384  */
385 
udpv6_recvmsg(struct sock * sk,struct msghdr * msg,size_t len,int flags,int * addr_len)386 int udpv6_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
387 		  int flags, int *addr_len)
388 {
389 	struct ipv6_pinfo *np = inet6_sk(sk);
390 	struct inet_sock *inet = inet_sk(sk);
391 	struct sk_buff *skb;
392 	unsigned int ulen, copied;
393 	int off, err, peeking = flags & MSG_PEEK;
394 	int is_udplite = IS_UDPLITE(sk);
395 	struct udp_mib __percpu *mib;
396 	bool checksum_valid = false;
397 	int is_udp4;
398 
399 	if (flags & MSG_ERRQUEUE)
400 		return ipv6_recv_error(sk, msg, len, addr_len);
401 
402 	if (np->rxpmtu && np->rxopt.bits.rxpmtu)
403 		return ipv6_recv_rxpmtu(sk, msg, len, addr_len);
404 
405 try_again:
406 	off = sk_peek_offset(sk, flags);
407 	skb = __skb_recv_udp(sk, flags, &off, &err);
408 	if (!skb)
409 		return err;
410 
411 	ulen = udp6_skb_len(skb);
412 	copied = len;
413 	if (copied > ulen - off)
414 		copied = ulen - off;
415 	else if (copied < ulen)
416 		msg->msg_flags |= MSG_TRUNC;
417 
418 	is_udp4 = (skb->protocol == htons(ETH_P_IP));
419 	mib = __UDPX_MIB(sk, is_udp4);
420 
421 	/*
422 	 * If checksum is needed at all, try to do it while copying the
423 	 * data.  If the data is truncated, or if we only want a partial
424 	 * coverage checksum (UDP-Lite), do it before the copy.
425 	 */
426 
427 	if (copied < ulen || peeking ||
428 	    (is_udplite && UDP_SKB_CB(skb)->partial_cov)) {
429 		checksum_valid = udp_skb_csum_unnecessary(skb) ||
430 				!__udp_lib_checksum_complete(skb);
431 		if (!checksum_valid)
432 			goto csum_copy_err;
433 	}
434 
435 	if (checksum_valid || udp_skb_csum_unnecessary(skb)) {
436 		if (udp_skb_is_linear(skb))
437 			err = copy_linear_skb(skb, copied, off, &msg->msg_iter);
438 		else
439 			err = skb_copy_datagram_msg(skb, off, msg, copied);
440 	} else {
441 		err = skb_copy_and_csum_datagram_msg(skb, off, msg);
442 		if (err == -EINVAL)
443 			goto csum_copy_err;
444 	}
445 	if (unlikely(err)) {
446 		if (!peeking) {
447 			atomic_inc(&sk->sk_drops);
448 			SNMP_INC_STATS(mib, UDP_MIB_INERRORS);
449 		}
450 		kfree_skb(skb);
451 		return err;
452 	}
453 	if (!peeking)
454 		SNMP_INC_STATS(mib, UDP_MIB_INDATAGRAMS);
455 
456 	sock_recv_cmsgs(msg, sk, skb);
457 
458 	/* Copy the address. */
459 	if (msg->msg_name) {
460 		DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name);
461 		sin6->sin6_family = AF_INET6;
462 		sin6->sin6_port = udp_hdr(skb)->source;
463 		sin6->sin6_flowinfo = 0;
464 
465 		if (is_udp4) {
466 			ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr,
467 					       &sin6->sin6_addr);
468 			sin6->sin6_scope_id = 0;
469 		} else {
470 			sin6->sin6_addr = ipv6_hdr(skb)->saddr;
471 			sin6->sin6_scope_id =
472 				ipv6_iface_scope_id(&sin6->sin6_addr,
473 						    inet6_iif(skb));
474 		}
475 		*addr_len = sizeof(*sin6);
476 
477 		BPF_CGROUP_RUN_PROG_UDP6_RECVMSG_LOCK(sk,
478 						      (struct sockaddr *)sin6,
479 						      addr_len);
480 	}
481 
482 	if (udp_test_bit(GRO_ENABLED, sk))
483 		udp_cmsg_recv(msg, sk, skb);
484 
485 	if (np->rxopt.all)
486 		ip6_datagram_recv_common_ctl(sk, msg, skb);
487 
488 	if (is_udp4) {
489 		if (inet_cmsg_flags(inet))
490 			ip_cmsg_recv_offset(msg, sk, skb,
491 					    sizeof(struct udphdr), off);
492 	} else {
493 		if (np->rxopt.all)
494 			ip6_datagram_recv_specific_ctl(sk, msg, skb);
495 	}
496 
497 	err = copied;
498 	if (flags & MSG_TRUNC)
499 		err = ulen;
500 
501 	skb_consume_udp(sk, skb, peeking ? -err : err);
502 	return err;
503 
504 csum_copy_err:
505 	if (!__sk_queue_drop_skb(sk, &udp_sk(sk)->reader_queue, skb, flags,
506 				 udp_skb_destructor)) {
507 		SNMP_INC_STATS(mib, UDP_MIB_CSUMERRORS);
508 		SNMP_INC_STATS(mib, UDP_MIB_INERRORS);
509 	}
510 	kfree_skb(skb);
511 
512 	/* starting over for a new packet, but check if we need to yield */
513 	cond_resched();
514 	msg->msg_flags &= ~MSG_TRUNC;
515 	goto try_again;
516 }
517 
518 DECLARE_STATIC_KEY_FALSE(udpv6_encap_needed_key);
udpv6_encap_enable(void)519 void udpv6_encap_enable(void)
520 {
521 	static_branch_inc(&udpv6_encap_needed_key);
522 }
523 EXPORT_SYMBOL(udpv6_encap_enable);
524 
525 /* Handler for tunnels with arbitrary destination ports: no socket lookup, go
526  * through error handlers in encapsulations looking for a match.
527  */
__udp6_lib_err_encap_no_sk(struct sk_buff * skb,struct inet6_skb_parm * opt,u8 type,u8 code,int offset,__be32 info)528 static int __udp6_lib_err_encap_no_sk(struct sk_buff *skb,
529 				      struct inet6_skb_parm *opt,
530 				      u8 type, u8 code, int offset, __be32 info)
531 {
532 	int i;
533 
534 	for (i = 0; i < MAX_IPTUN_ENCAP_OPS; i++) {
535 		int (*handler)(struct sk_buff *skb, struct inet6_skb_parm *opt,
536 			       u8 type, u8 code, int offset, __be32 info);
537 		const struct ip6_tnl_encap_ops *encap;
538 
539 		encap = rcu_dereference(ip6tun_encaps[i]);
540 		if (!encap)
541 			continue;
542 		handler = encap->err_handler;
543 		if (handler && !handler(skb, opt, type, code, offset, info))
544 			return 0;
545 	}
546 
547 	return -ENOENT;
548 }
549 
550 /* Try to match ICMP errors to UDP tunnels by looking up a socket without
551  * reversing source and destination port: this will match tunnels that force the
552  * same destination port on both endpoints (e.g. VXLAN, GENEVE). Note that
553  * lwtunnels might actually break this assumption by being configured with
554  * different destination ports on endpoints, in this case we won't be able to
555  * trace ICMP messages back to them.
556  *
557  * If this doesn't match any socket, probe tunnels with arbitrary destination
558  * ports (e.g. FoU, GUE): there, the receiving socket is useless, as the port
559  * we've sent packets to won't necessarily match the local destination port.
560  *
561  * Then ask the tunnel implementation to match the error against a valid
562  * association.
563  *
564  * Return an error if we can't find a match, the socket if we need further
565  * processing, zero otherwise.
566  */
__udp6_lib_err_encap(struct net * net,const struct ipv6hdr * hdr,int offset,struct udphdr * uh,struct udp_table * udptable,struct sock * sk,struct sk_buff * skb,struct inet6_skb_parm * opt,u8 type,u8 code,__be32 info)567 static struct sock *__udp6_lib_err_encap(struct net *net,
568 					 const struct ipv6hdr *hdr, int offset,
569 					 struct udphdr *uh,
570 					 struct udp_table *udptable,
571 					 struct sock *sk,
572 					 struct sk_buff *skb,
573 					 struct inet6_skb_parm *opt,
574 					 u8 type, u8 code, __be32 info)
575 {
576 	int (*lookup)(struct sock *sk, struct sk_buff *skb);
577 	int network_offset, transport_offset;
578 	struct udp_sock *up;
579 
580 	network_offset = skb_network_offset(skb);
581 	transport_offset = skb_transport_offset(skb);
582 
583 	/* Network header needs to point to the outer IPv6 header inside ICMP */
584 	skb_reset_network_header(skb);
585 
586 	/* Transport header needs to point to the UDP header */
587 	skb_set_transport_header(skb, offset);
588 
589 	if (sk) {
590 		up = udp_sk(sk);
591 
592 		lookup = READ_ONCE(up->encap_err_lookup);
593 		if (lookup && lookup(sk, skb))
594 			sk = NULL;
595 
596 		goto out;
597 	}
598 
599 	sk = __udp6_lib_lookup(net, &hdr->daddr, uh->source,
600 			       &hdr->saddr, uh->dest,
601 			       inet6_iif(skb), 0, udptable, skb);
602 	if (sk) {
603 		up = udp_sk(sk);
604 
605 		lookup = READ_ONCE(up->encap_err_lookup);
606 		if (!lookup || lookup(sk, skb))
607 			sk = NULL;
608 	}
609 
610 out:
611 	if (!sk) {
612 		sk = ERR_PTR(__udp6_lib_err_encap_no_sk(skb, opt, type, code,
613 							offset, info));
614 	}
615 
616 	skb_set_transport_header(skb, transport_offset);
617 	skb_set_network_header(skb, network_offset);
618 
619 	return sk;
620 }
621 
__udp6_lib_err(struct sk_buff * skb,struct inet6_skb_parm * opt,u8 type,u8 code,int offset,__be32 info,struct udp_table * udptable)622 int __udp6_lib_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
623 		   u8 type, u8 code, int offset, __be32 info,
624 		   struct udp_table *udptable)
625 {
626 	struct ipv6_pinfo *np;
627 	const struct ipv6hdr *hdr = (const struct ipv6hdr *)skb->data;
628 	const struct in6_addr *saddr = &hdr->saddr;
629 	const struct in6_addr *daddr = seg6_get_daddr(skb, opt) ? : &hdr->daddr;
630 	struct udphdr *uh = (struct udphdr *)(skb->data+offset);
631 	bool tunnel = false;
632 	struct sock *sk;
633 	int harderr;
634 	int err;
635 	struct net *net = dev_net(skb->dev);
636 
637 	sk = __udp6_lib_lookup(net, daddr, uh->dest, saddr, uh->source,
638 			       inet6_iif(skb), inet6_sdif(skb), udptable, NULL);
639 
640 	if (!sk || READ_ONCE(udp_sk(sk)->encap_type)) {
641 		/* No socket for error: try tunnels before discarding */
642 		if (static_branch_unlikely(&udpv6_encap_needed_key)) {
643 			sk = __udp6_lib_err_encap(net, hdr, offset, uh,
644 						  udptable, sk, skb,
645 						  opt, type, code, info);
646 			if (!sk)
647 				return 0;
648 		} else
649 			sk = ERR_PTR(-ENOENT);
650 
651 		if (IS_ERR(sk)) {
652 			__ICMP6_INC_STATS(net, __in6_dev_get(skb->dev),
653 					  ICMP6_MIB_INERRORS);
654 			return PTR_ERR(sk);
655 		}
656 
657 		tunnel = true;
658 	}
659 
660 	harderr = icmpv6_err_convert(type, code, &err);
661 	np = inet6_sk(sk);
662 
663 	if (type == ICMPV6_PKT_TOOBIG) {
664 		if (!ip6_sk_accept_pmtu(sk))
665 			goto out;
666 		ip6_sk_update_pmtu(skb, sk, info);
667 		if (np->pmtudisc != IPV6_PMTUDISC_DONT)
668 			harderr = 1;
669 	}
670 	if (type == NDISC_REDIRECT) {
671 		if (tunnel) {
672 			ip6_redirect(skb, sock_net(sk), inet6_iif(skb),
673 				     READ_ONCE(sk->sk_mark), sk->sk_uid);
674 		} else {
675 			ip6_sk_redirect(skb, sk);
676 		}
677 		goto out;
678 	}
679 
680 	/* Tunnels don't have an application socket: don't pass errors back */
681 	if (tunnel) {
682 		if (udp_sk(sk)->encap_err_rcv)
683 			udp_sk(sk)->encap_err_rcv(sk, skb, err, uh->dest,
684 						  ntohl(info), (u8 *)(uh+1));
685 		goto out;
686 	}
687 
688 	if (!np->recverr) {
689 		if (!harderr || sk->sk_state != TCP_ESTABLISHED)
690 			goto out;
691 	} else {
692 		ipv6_icmp_error(sk, skb, err, uh->dest, ntohl(info), (u8 *)(uh+1));
693 	}
694 
695 	sk->sk_err = err;
696 	sk_error_report(sk);
697 out:
698 	return 0;
699 }
700 
__udpv6_queue_rcv_skb(struct sock * sk,struct sk_buff * skb)701 static int __udpv6_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
702 {
703 	int rc;
704 
705 	if (!ipv6_addr_any(&sk->sk_v6_daddr)) {
706 		sock_rps_save_rxhash(sk, skb);
707 		sk_mark_napi_id(sk, skb);
708 		sk_incoming_cpu_update(sk);
709 	} else {
710 		sk_mark_napi_id_once(sk, skb);
711 	}
712 
713 	rc = __udp_enqueue_schedule_skb(sk, skb);
714 	if (rc < 0) {
715 		int is_udplite = IS_UDPLITE(sk);
716 		enum skb_drop_reason drop_reason;
717 
718 		/* Note that an ENOMEM error is charged twice */
719 		if (rc == -ENOMEM) {
720 			UDP6_INC_STATS(sock_net(sk),
721 					 UDP_MIB_RCVBUFERRORS, is_udplite);
722 			drop_reason = SKB_DROP_REASON_SOCKET_RCVBUFF;
723 		} else {
724 			UDP6_INC_STATS(sock_net(sk),
725 				       UDP_MIB_MEMERRORS, is_udplite);
726 			drop_reason = SKB_DROP_REASON_PROTO_MEM;
727 		}
728 		UDP6_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
729 		kfree_skb_reason(skb, drop_reason);
730 		trace_udp_fail_queue_rcv_skb(rc, sk);
731 		return -1;
732 	}
733 
734 	return 0;
735 }
736 
udpv6_err(struct sk_buff * skb,struct inet6_skb_parm * opt,u8 type,u8 code,int offset,__be32 info)737 static __inline__ int udpv6_err(struct sk_buff *skb,
738 				struct inet6_skb_parm *opt, u8 type,
739 				u8 code, int offset, __be32 info)
740 {
741 	return __udp6_lib_err(skb, opt, type, code, offset, info,
742 			      dev_net(skb->dev)->ipv4.udp_table);
743 }
744 
udpv6_queue_rcv_one_skb(struct sock * sk,struct sk_buff * skb)745 static int udpv6_queue_rcv_one_skb(struct sock *sk, struct sk_buff *skb)
746 {
747 	enum skb_drop_reason drop_reason = SKB_DROP_REASON_NOT_SPECIFIED;
748 	struct udp_sock *up = udp_sk(sk);
749 	int is_udplite = IS_UDPLITE(sk);
750 
751 	if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb)) {
752 		drop_reason = SKB_DROP_REASON_XFRM_POLICY;
753 		goto drop;
754 	}
755 	nf_reset_ct(skb);
756 
757 	if (static_branch_unlikely(&udpv6_encap_needed_key) &&
758 	    READ_ONCE(up->encap_type)) {
759 		int (*encap_rcv)(struct sock *sk, struct sk_buff *skb);
760 
761 		/*
762 		 * This is an encapsulation socket so pass the skb to
763 		 * the socket's udp_encap_rcv() hook. Otherwise, just
764 		 * fall through and pass this up the UDP socket.
765 		 * up->encap_rcv() returns the following value:
766 		 * =0 if skb was successfully passed to the encap
767 		 *    handler or was discarded by it.
768 		 * >0 if skb should be passed on to UDP.
769 		 * <0 if skb should be resubmitted as proto -N
770 		 */
771 
772 		/* if we're overly short, let UDP handle it */
773 		encap_rcv = READ_ONCE(up->encap_rcv);
774 		if (encap_rcv) {
775 			int ret;
776 
777 			/* Verify checksum before giving to encap */
778 			if (udp_lib_checksum_complete(skb))
779 				goto csum_error;
780 
781 			ret = encap_rcv(sk, skb);
782 			if (ret <= 0) {
783 				__UDP6_INC_STATS(sock_net(sk),
784 						 UDP_MIB_INDATAGRAMS,
785 						 is_udplite);
786 				return -ret;
787 			}
788 		}
789 
790 		/* FALLTHROUGH -- it's a UDP Packet */
791 	}
792 
793 	/*
794 	 * UDP-Lite specific tests, ignored on UDP sockets (see net/ipv4/udp.c).
795 	 */
796 	if (udp_test_bit(UDPLITE_RECV_CC, sk) && UDP_SKB_CB(skb)->partial_cov) {
797 		u16 pcrlen = READ_ONCE(up->pcrlen);
798 
799 		if (pcrlen == 0) {          /* full coverage was set  */
800 			net_dbg_ratelimited("UDPLITE6: partial coverage %d while full coverage %d requested\n",
801 					    UDP_SKB_CB(skb)->cscov, skb->len);
802 			goto drop;
803 		}
804 		if (UDP_SKB_CB(skb)->cscov < pcrlen) {
805 			net_dbg_ratelimited("UDPLITE6: coverage %d too small, need min %d\n",
806 					    UDP_SKB_CB(skb)->cscov, pcrlen);
807 			goto drop;
808 		}
809 	}
810 
811 	prefetch(&sk->sk_rmem_alloc);
812 	if (rcu_access_pointer(sk->sk_filter) &&
813 	    udp_lib_checksum_complete(skb))
814 		goto csum_error;
815 
816 	if (sk_filter_trim_cap(sk, skb, sizeof(struct udphdr))) {
817 		drop_reason = SKB_DROP_REASON_SOCKET_FILTER;
818 		goto drop;
819 	}
820 
821 	udp_csum_pull_header(skb);
822 
823 	skb_dst_drop(skb);
824 
825 	return __udpv6_queue_rcv_skb(sk, skb);
826 
827 csum_error:
828 	drop_reason = SKB_DROP_REASON_UDP_CSUM;
829 	__UDP6_INC_STATS(sock_net(sk), UDP_MIB_CSUMERRORS, is_udplite);
830 drop:
831 	__UDP6_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
832 	atomic_inc(&sk->sk_drops);
833 	kfree_skb_reason(skb, drop_reason);
834 	return -1;
835 }
836 
udpv6_queue_rcv_skb(struct sock * sk,struct sk_buff * skb)837 static int udpv6_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
838 {
839 	struct sk_buff *next, *segs;
840 	int ret;
841 
842 	if (likely(!udp_unexpected_gso(sk, skb)))
843 		return udpv6_queue_rcv_one_skb(sk, skb);
844 
845 	__skb_push(skb, -skb_mac_offset(skb));
846 	segs = udp_rcv_segment(sk, skb, false);
847 	skb_list_walk_safe(segs, skb, next) {
848 		__skb_pull(skb, skb_transport_offset(skb));
849 
850 		udp_post_segment_fix_csum(skb);
851 		ret = udpv6_queue_rcv_one_skb(sk, skb);
852 		if (ret > 0)
853 			ip6_protocol_deliver_rcu(dev_net(skb->dev), skb, ret,
854 						 true);
855 	}
856 	return 0;
857 }
858 
__udp_v6_is_mcast_sock(struct net * net,const 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)859 static bool __udp_v6_is_mcast_sock(struct net *net, const struct sock *sk,
860 				   __be16 loc_port, const struct in6_addr *loc_addr,
861 				   __be16 rmt_port, const struct in6_addr *rmt_addr,
862 				   int dif, int sdif, unsigned short hnum)
863 {
864 	const struct inet_sock *inet = inet_sk(sk);
865 
866 	if (!net_eq(sock_net(sk), net))
867 		return false;
868 
869 	if (udp_sk(sk)->udp_port_hash != hnum ||
870 	    sk->sk_family != PF_INET6 ||
871 	    (inet->inet_dport && inet->inet_dport != rmt_port) ||
872 	    (!ipv6_addr_any(&sk->sk_v6_daddr) &&
873 		    !ipv6_addr_equal(&sk->sk_v6_daddr, rmt_addr)) ||
874 	    !udp_sk_bound_dev_eq(net, READ_ONCE(sk->sk_bound_dev_if), dif, sdif) ||
875 	    (!ipv6_addr_any(&sk->sk_v6_rcv_saddr) &&
876 		    !ipv6_addr_equal(&sk->sk_v6_rcv_saddr, loc_addr)))
877 		return false;
878 	if (!inet6_mc_check(sk, loc_addr, rmt_addr))
879 		return false;
880 	return true;
881 }
882 
udp6_csum_zero_error(struct sk_buff * skb)883 static void udp6_csum_zero_error(struct sk_buff *skb)
884 {
885 	/* RFC 2460 section 8.1 says that we SHOULD log
886 	 * this error. Well, it is reasonable.
887 	 */
888 	net_dbg_ratelimited("IPv6: udp checksum is 0 for [%pI6c]:%u->[%pI6c]:%u\n",
889 			    &ipv6_hdr(skb)->saddr, ntohs(udp_hdr(skb)->source),
890 			    &ipv6_hdr(skb)->daddr, ntohs(udp_hdr(skb)->dest));
891 }
892 
893 /*
894  * Note: called only from the BH handler context,
895  * so we don't need to lock the hashes.
896  */
__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)897 static int __udp6_lib_mcast_deliver(struct net *net, struct sk_buff *skb,
898 		const struct in6_addr *saddr, const struct in6_addr *daddr,
899 		struct udp_table *udptable, int proto)
900 {
901 	struct sock *sk, *first = NULL;
902 	const struct udphdr *uh = udp_hdr(skb);
903 	unsigned short hnum = ntohs(uh->dest);
904 	struct udp_hslot *hslot = udp_hashslot(udptable, net, hnum);
905 	unsigned int offset = offsetof(typeof(*sk), sk_node);
906 	unsigned int hash2 = 0, hash2_any = 0, use_hash2 = (hslot->count > 10);
907 	int dif = inet6_iif(skb);
908 	int sdif = inet6_sdif(skb);
909 	struct hlist_node *node;
910 	struct sk_buff *nskb;
911 
912 	if (use_hash2) {
913 		hash2_any = ipv6_portaddr_hash(net, &in6addr_any, hnum) &
914 			    udptable->mask;
915 		hash2 = ipv6_portaddr_hash(net, daddr, hnum) & udptable->mask;
916 start_lookup:
917 		hslot = &udptable->hash2[hash2];
918 		offset = offsetof(typeof(*sk), __sk_common.skc_portaddr_node);
919 	}
920 
921 	sk_for_each_entry_offset_rcu(sk, node, &hslot->head, offset) {
922 		if (!__udp_v6_is_mcast_sock(net, sk, uh->dest, daddr,
923 					    uh->source, saddr, dif, sdif,
924 					    hnum))
925 			continue;
926 		/* If zero checksum and no_check is not on for
927 		 * the socket then skip it.
928 		 */
929 		if (!uh->check && !udp_get_no_check6_rx(sk))
930 			continue;
931 		if (!first) {
932 			first = sk;
933 			continue;
934 		}
935 		nskb = skb_clone(skb, GFP_ATOMIC);
936 		if (unlikely(!nskb)) {
937 			atomic_inc(&sk->sk_drops);
938 			__UDP6_INC_STATS(net, UDP_MIB_RCVBUFERRORS,
939 					 IS_UDPLITE(sk));
940 			__UDP6_INC_STATS(net, UDP_MIB_INERRORS,
941 					 IS_UDPLITE(sk));
942 			continue;
943 		}
944 
945 		if (udpv6_queue_rcv_skb(sk, nskb) > 0)
946 			consume_skb(nskb);
947 	}
948 
949 	/* Also lookup *:port if we are using hash2 and haven't done so yet. */
950 	if (use_hash2 && hash2 != hash2_any) {
951 		hash2 = hash2_any;
952 		goto start_lookup;
953 	}
954 
955 	if (first) {
956 		if (udpv6_queue_rcv_skb(first, skb) > 0)
957 			consume_skb(skb);
958 	} else {
959 		kfree_skb(skb);
960 		__UDP6_INC_STATS(net, UDP_MIB_IGNOREDMULTI,
961 				 proto == IPPROTO_UDPLITE);
962 	}
963 	return 0;
964 }
965 
udp6_sk_rx_dst_set(struct sock * sk,struct dst_entry * dst)966 static void udp6_sk_rx_dst_set(struct sock *sk, struct dst_entry *dst)
967 {
968 	if (udp_sk_rx_dst_set(sk, dst))
969 		sk->sk_rx_dst_cookie = rt6_get_cookie(dst_rt6_info(dst));
970 }
971 
972 /* wrapper for udp_queue_rcv_skb tacking care of csum conversion and
973  * return code conversion for ip layer consumption
974  */
udp6_unicast_rcv_skb(struct sock * sk,struct sk_buff * skb,struct udphdr * uh)975 static int udp6_unicast_rcv_skb(struct sock *sk, struct sk_buff *skb,
976 				struct udphdr *uh)
977 {
978 	int ret;
979 
980 	if (inet_get_convert_csum(sk) && uh->check && !IS_UDPLITE(sk))
981 		skb_checksum_try_convert(skb, IPPROTO_UDP, ip6_compute_pseudo);
982 
983 	ret = udpv6_queue_rcv_skb(sk, skb);
984 
985 	/* a return value > 0 means to resubmit the input */
986 	if (ret > 0)
987 		return ret;
988 	return 0;
989 }
990 
__udp6_lib_rcv(struct sk_buff * skb,struct udp_table * udptable,int proto)991 int __udp6_lib_rcv(struct sk_buff *skb, struct udp_table *udptable,
992 		   int proto)
993 {
994 	enum skb_drop_reason reason = SKB_DROP_REASON_NOT_SPECIFIED;
995 	const struct in6_addr *saddr, *daddr;
996 	struct net *net = dev_net(skb->dev);
997 	struct udphdr *uh;
998 	struct sock *sk;
999 	bool refcounted;
1000 	u32 ulen = 0;
1001 
1002 	if (!pskb_may_pull(skb, sizeof(struct udphdr)))
1003 		goto discard;
1004 
1005 	saddr = &ipv6_hdr(skb)->saddr;
1006 	daddr = &ipv6_hdr(skb)->daddr;
1007 	uh = udp_hdr(skb);
1008 
1009 	ulen = ntohs(uh->len);
1010 	if (ulen > skb->len)
1011 		goto short_packet;
1012 
1013 	if (proto == IPPROTO_UDP) {
1014 		/* UDP validates ulen. */
1015 
1016 		/* Check for jumbo payload */
1017 		if (ulen == 0)
1018 			ulen = skb->len;
1019 
1020 		if (ulen < sizeof(*uh))
1021 			goto short_packet;
1022 
1023 		if (ulen < skb->len) {
1024 			if (pskb_trim_rcsum(skb, ulen))
1025 				goto short_packet;
1026 			saddr = &ipv6_hdr(skb)->saddr;
1027 			daddr = &ipv6_hdr(skb)->daddr;
1028 			uh = udp_hdr(skb);
1029 		}
1030 	}
1031 
1032 	if (udp6_csum_init(skb, uh, proto))
1033 		goto csum_error;
1034 
1035 	/* Check if the socket is already available, e.g. due to early demux */
1036 	sk = inet6_steal_sock(net, skb, sizeof(struct udphdr), saddr, uh->source, daddr, uh->dest,
1037 			      &refcounted, udp6_ehashfn);
1038 	if (IS_ERR(sk))
1039 		goto no_sk;
1040 
1041 	if (sk) {
1042 		struct dst_entry *dst = skb_dst(skb);
1043 		int ret;
1044 
1045 		if (unlikely(rcu_dereference(sk->sk_rx_dst) != dst))
1046 			udp6_sk_rx_dst_set(sk, dst);
1047 
1048 		if (!uh->check && !udp_get_no_check6_rx(sk)) {
1049 			if (refcounted)
1050 				sock_put(sk);
1051 			goto report_csum_error;
1052 		}
1053 
1054 		ret = udp6_unicast_rcv_skb(sk, skb, uh);
1055 		if (refcounted)
1056 			sock_put(sk);
1057 		return ret;
1058 	}
1059 
1060 	/*
1061 	 *	Multicast receive code
1062 	 */
1063 	if (ipv6_addr_is_multicast(daddr))
1064 		return __udp6_lib_mcast_deliver(net, skb,
1065 				saddr, daddr, udptable, proto);
1066 
1067 	/* Unicast */
1068 	sk = __udp6_lib_lookup_skb(skb, uh->source, uh->dest, udptable);
1069 	if (sk) {
1070 		if (!uh->check && !udp_get_no_check6_rx(sk))
1071 			goto report_csum_error;
1072 		return udp6_unicast_rcv_skb(sk, skb, uh);
1073 	}
1074 no_sk:
1075 	reason = SKB_DROP_REASON_NO_SOCKET;
1076 
1077 	if (!uh->check)
1078 		goto report_csum_error;
1079 
1080 	if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
1081 		goto discard;
1082 	nf_reset_ct(skb);
1083 
1084 	if (udp_lib_checksum_complete(skb))
1085 		goto csum_error;
1086 
1087 	__UDP6_INC_STATS(net, UDP_MIB_NOPORTS, proto == IPPROTO_UDPLITE);
1088 	icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0);
1089 
1090 	kfree_skb_reason(skb, reason);
1091 	return 0;
1092 
1093 short_packet:
1094 	if (reason == SKB_DROP_REASON_NOT_SPECIFIED)
1095 		reason = SKB_DROP_REASON_PKT_TOO_SMALL;
1096 	net_dbg_ratelimited("UDP%sv6: short packet: From [%pI6c]:%u %d/%d to [%pI6c]:%u\n",
1097 			    proto == IPPROTO_UDPLITE ? "-Lite" : "",
1098 			    saddr, ntohs(uh->source),
1099 			    ulen, skb->len,
1100 			    daddr, ntohs(uh->dest));
1101 	goto discard;
1102 
1103 report_csum_error:
1104 	udp6_csum_zero_error(skb);
1105 csum_error:
1106 	if (reason == SKB_DROP_REASON_NOT_SPECIFIED)
1107 		reason = SKB_DROP_REASON_UDP_CSUM;
1108 	__UDP6_INC_STATS(net, UDP_MIB_CSUMERRORS, proto == IPPROTO_UDPLITE);
1109 discard:
1110 	__UDP6_INC_STATS(net, UDP_MIB_INERRORS, proto == IPPROTO_UDPLITE);
1111 	kfree_skb_reason(skb, reason);
1112 	return 0;
1113 }
1114 
1115 
__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)1116 static struct sock *__udp6_lib_demux_lookup(struct net *net,
1117 			__be16 loc_port, const struct in6_addr *loc_addr,
1118 			__be16 rmt_port, const struct in6_addr *rmt_addr,
1119 			int dif, int sdif)
1120 {
1121 	struct udp_table *udptable = net->ipv4.udp_table;
1122 	unsigned short hnum = ntohs(loc_port);
1123 	unsigned int hash2, slot2;
1124 	struct udp_hslot *hslot2;
1125 	__portpair ports;
1126 	struct sock *sk;
1127 
1128 	hash2 = ipv6_portaddr_hash(net, loc_addr, hnum);
1129 	slot2 = hash2 & udptable->mask;
1130 	hslot2 = &udptable->hash2[slot2];
1131 	ports = INET_COMBINED_PORTS(rmt_port, hnum);
1132 
1133 	udp_portaddr_for_each_entry_rcu(sk, &hslot2->head) {
1134 		if (sk->sk_state == TCP_ESTABLISHED &&
1135 		    inet6_match(net, sk, rmt_addr, loc_addr, ports, dif, sdif))
1136 			return sk;
1137 		/* Only check first socket in chain */
1138 		break;
1139 	}
1140 	return NULL;
1141 }
1142 
udp_v6_early_demux(struct sk_buff * skb)1143 void udp_v6_early_demux(struct sk_buff *skb)
1144 {
1145 	struct net *net = dev_net(skb->dev);
1146 	const struct udphdr *uh;
1147 	struct sock *sk;
1148 	struct dst_entry *dst;
1149 	int dif = skb->dev->ifindex;
1150 	int sdif = inet6_sdif(skb);
1151 
1152 	if (!pskb_may_pull(skb, skb_transport_offset(skb) +
1153 	    sizeof(struct udphdr)))
1154 		return;
1155 
1156 	uh = udp_hdr(skb);
1157 
1158 	if (skb->pkt_type == PACKET_HOST)
1159 		sk = __udp6_lib_demux_lookup(net, uh->dest,
1160 					     &ipv6_hdr(skb)->daddr,
1161 					     uh->source, &ipv6_hdr(skb)->saddr,
1162 					     dif, sdif);
1163 	else
1164 		return;
1165 
1166 	if (!sk || !refcount_inc_not_zero(&sk->sk_refcnt))
1167 		return;
1168 
1169 	skb->sk = sk;
1170 	skb->destructor = sock_efree;
1171 	dst = rcu_dereference(sk->sk_rx_dst);
1172 
1173 	if (dst)
1174 		dst = dst_check(dst, sk->sk_rx_dst_cookie);
1175 	if (dst) {
1176 		/* set noref for now.
1177 		 * any place which wants to hold dst has to call
1178 		 * dst_hold_safe()
1179 		 */
1180 		skb_dst_set_noref(skb, dst);
1181 	}
1182 }
1183 
udpv6_rcv(struct sk_buff * skb)1184 INDIRECT_CALLABLE_SCOPE int udpv6_rcv(struct sk_buff *skb)
1185 {
1186 	return __udp6_lib_rcv(skb, dev_net(skb->dev)->ipv4.udp_table, IPPROTO_UDP);
1187 }
1188 
1189 /*
1190  * Throw away all pending data and cancel the corking. Socket is locked.
1191  */
udp_v6_flush_pending_frames(struct sock * sk)1192 static void udp_v6_flush_pending_frames(struct sock *sk)
1193 {
1194 	struct udp_sock *up = udp_sk(sk);
1195 
1196 	if (up->pending == AF_INET)
1197 		udp_flush_pending_frames(sk);
1198 	else if (up->pending) {
1199 		up->len = 0;
1200 		WRITE_ONCE(up->pending, 0);
1201 		ip6_flush_pending_frames(sk);
1202 	}
1203 }
1204 
udpv6_pre_connect(struct sock * sk,struct sockaddr * uaddr,int addr_len)1205 static int udpv6_pre_connect(struct sock *sk, struct sockaddr *uaddr,
1206 			     int addr_len)
1207 {
1208 	if (addr_len < offsetofend(struct sockaddr, sa_family))
1209 		return -EINVAL;
1210 	/* The following checks are replicated from __ip6_datagram_connect()
1211 	 * and intended to prevent BPF program called below from accessing
1212 	 * bytes that are out of the bound specified by user in addr_len.
1213 	 */
1214 	if (uaddr->sa_family == AF_INET) {
1215 		if (ipv6_only_sock(sk))
1216 			return -EAFNOSUPPORT;
1217 		return udp_pre_connect(sk, uaddr, addr_len);
1218 	}
1219 
1220 	if (addr_len < SIN6_LEN_RFC2133)
1221 		return -EINVAL;
1222 
1223 	return BPF_CGROUP_RUN_PROG_INET6_CONNECT_LOCK(sk, uaddr, &addr_len);
1224 }
1225 
1226 /**
1227  *	udp6_hwcsum_outgoing  -  handle outgoing HW checksumming
1228  *	@sk:	socket we are sending on
1229  *	@skb:	sk_buff containing the filled-in UDP header
1230  *		(checksum field must be zeroed out)
1231  *	@saddr: source address
1232  *	@daddr: destination address
1233  *	@len:	length of packet
1234  */
udp6_hwcsum_outgoing(struct sock * sk,struct sk_buff * skb,const struct in6_addr * saddr,const struct in6_addr * daddr,int len)1235 static void udp6_hwcsum_outgoing(struct sock *sk, struct sk_buff *skb,
1236 				 const struct in6_addr *saddr,
1237 				 const struct in6_addr *daddr, int len)
1238 {
1239 	unsigned int offset;
1240 	struct udphdr *uh = udp_hdr(skb);
1241 	struct sk_buff *frags = skb_shinfo(skb)->frag_list;
1242 	__wsum csum = 0;
1243 
1244 	if (!frags) {
1245 		/* Only one fragment on the socket.  */
1246 		skb->csum_start = skb_transport_header(skb) - skb->head;
1247 		skb->csum_offset = offsetof(struct udphdr, check);
1248 		uh->check = ~csum_ipv6_magic(saddr, daddr, len, IPPROTO_UDP, 0);
1249 	} else {
1250 		/*
1251 		 * HW-checksum won't work as there are two or more
1252 		 * fragments on the socket so that all csums of sk_buffs
1253 		 * should be together
1254 		 */
1255 		offset = skb_transport_offset(skb);
1256 		skb->csum = skb_checksum(skb, offset, skb->len - offset, 0);
1257 		csum = skb->csum;
1258 
1259 		skb->ip_summed = CHECKSUM_NONE;
1260 
1261 		do {
1262 			csum = csum_add(csum, frags->csum);
1263 		} while ((frags = frags->next));
1264 
1265 		uh->check = csum_ipv6_magic(saddr, daddr, len, IPPROTO_UDP,
1266 					    csum);
1267 		if (uh->check == 0)
1268 			uh->check = CSUM_MANGLED_0;
1269 	}
1270 }
1271 
1272 /*
1273  *	Sending
1274  */
1275 
udp_v6_send_skb(struct sk_buff * skb,struct flowi6 * fl6,struct inet_cork * cork)1276 static int udp_v6_send_skb(struct sk_buff *skb, struct flowi6 *fl6,
1277 			   struct inet_cork *cork)
1278 {
1279 	struct sock *sk = skb->sk;
1280 	struct udphdr *uh;
1281 	int err = 0;
1282 	int is_udplite = IS_UDPLITE(sk);
1283 	__wsum csum = 0;
1284 	int offset = skb_transport_offset(skb);
1285 	int len = skb->len - offset;
1286 	int datalen = len - sizeof(*uh);
1287 
1288 	/*
1289 	 * Create a UDP header
1290 	 */
1291 	uh = udp_hdr(skb);
1292 	uh->source = fl6->fl6_sport;
1293 	uh->dest = fl6->fl6_dport;
1294 	uh->len = htons(len);
1295 	uh->check = 0;
1296 
1297 	if (cork->gso_size) {
1298 		const int hlen = skb_network_header_len(skb) +
1299 				 sizeof(struct udphdr);
1300 
1301 		if (hlen + min(datalen, cork->gso_size) > cork->fragsize) {
1302 			kfree_skb(skb);
1303 			return -EMSGSIZE;
1304 		}
1305 		if (datalen > cork->gso_size * UDP_MAX_SEGMENTS) {
1306 			kfree_skb(skb);
1307 			return -EINVAL;
1308 		}
1309 		if (udp_get_no_check6_tx(sk)) {
1310 			kfree_skb(skb);
1311 			return -EINVAL;
1312 		}
1313 		if (skb->ip_summed != CHECKSUM_PARTIAL || is_udplite ||
1314 		    dst_xfrm(skb_dst(skb))) {
1315 			kfree_skb(skb);
1316 			return -EIO;
1317 		}
1318 
1319 		if (datalen > cork->gso_size) {
1320 			skb_shinfo(skb)->gso_size = cork->gso_size;
1321 			skb_shinfo(skb)->gso_type = SKB_GSO_UDP_L4;
1322 			skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(datalen,
1323 								 cork->gso_size);
1324 		}
1325 		goto csum_partial;
1326 	}
1327 
1328 	if (is_udplite)
1329 		csum = udplite_csum(skb);
1330 	else if (udp_get_no_check6_tx(sk)) {   /* UDP csum disabled */
1331 		skb->ip_summed = CHECKSUM_NONE;
1332 		goto send;
1333 	} else if (skb->ip_summed == CHECKSUM_PARTIAL) { /* UDP hardware csum */
1334 csum_partial:
1335 		udp6_hwcsum_outgoing(sk, skb, &fl6->saddr, &fl6->daddr, len);
1336 		goto send;
1337 	} else
1338 		csum = udp_csum(skb);
1339 
1340 	/* add protocol-dependent pseudo-header */
1341 	uh->check = csum_ipv6_magic(&fl6->saddr, &fl6->daddr,
1342 				    len, fl6->flowi6_proto, csum);
1343 	if (uh->check == 0)
1344 		uh->check = CSUM_MANGLED_0;
1345 
1346 send:
1347 	err = ip6_send_skb(skb);
1348 	if (err) {
1349 		if (err == -ENOBUFS && !inet6_sk(sk)->recverr) {
1350 			UDP6_INC_STATS(sock_net(sk),
1351 				       UDP_MIB_SNDBUFERRORS, is_udplite);
1352 			err = 0;
1353 		}
1354 	} else {
1355 		UDP6_INC_STATS(sock_net(sk),
1356 			       UDP_MIB_OUTDATAGRAMS, is_udplite);
1357 	}
1358 	return err;
1359 }
1360 
udp_v6_push_pending_frames(struct sock * sk)1361 static int udp_v6_push_pending_frames(struct sock *sk)
1362 {
1363 	struct sk_buff *skb;
1364 	struct udp_sock  *up = udp_sk(sk);
1365 	int err = 0;
1366 
1367 	if (up->pending == AF_INET)
1368 		return udp_push_pending_frames(sk);
1369 
1370 	skb = ip6_finish_skb(sk);
1371 	if (!skb)
1372 		goto out;
1373 
1374 	err = udp_v6_send_skb(skb, &inet_sk(sk)->cork.fl.u.ip6,
1375 			      &inet_sk(sk)->cork.base);
1376 out:
1377 	up->len = 0;
1378 	WRITE_ONCE(up->pending, 0);
1379 	return err;
1380 }
1381 
udpv6_sendmsg(struct sock * sk,struct msghdr * msg,size_t len)1382 int udpv6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
1383 {
1384 	struct ipv6_txoptions opt_space;
1385 	struct udp_sock *up = udp_sk(sk);
1386 	struct inet_sock *inet = inet_sk(sk);
1387 	struct ipv6_pinfo *np = inet6_sk(sk);
1388 	DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name);
1389 	struct in6_addr *daddr, *final_p, final;
1390 	struct ipv6_txoptions *opt = NULL;
1391 	struct ipv6_txoptions *opt_to_free = NULL;
1392 	struct ip6_flowlabel *flowlabel = NULL;
1393 	struct inet_cork_full cork;
1394 	struct flowi6 *fl6 = &cork.fl.u.ip6;
1395 	struct dst_entry *dst;
1396 	struct ipcm6_cookie ipc6;
1397 	int addr_len = msg->msg_namelen;
1398 	bool connected = false;
1399 	int ulen = len;
1400 	int corkreq = udp_test_bit(CORK, sk) || msg->msg_flags & MSG_MORE;
1401 	int err;
1402 	int is_udplite = IS_UDPLITE(sk);
1403 	int (*getfrag)(void *, char *, int, int, int, struct sk_buff *);
1404 
1405 	ipcm6_init(&ipc6);
1406 	ipc6.gso_size = READ_ONCE(up->gso_size);
1407 	ipc6.sockc.tsflags = READ_ONCE(sk->sk_tsflags);
1408 	ipc6.sockc.mark = READ_ONCE(sk->sk_mark);
1409 
1410 	/* destination address check */
1411 	if (sin6) {
1412 		if (addr_len < offsetof(struct sockaddr, sa_data))
1413 			return -EINVAL;
1414 
1415 		switch (sin6->sin6_family) {
1416 		case AF_INET6:
1417 			if (addr_len < SIN6_LEN_RFC2133)
1418 				return -EINVAL;
1419 			daddr = &sin6->sin6_addr;
1420 			if (ipv6_addr_any(daddr) &&
1421 			    ipv6_addr_v4mapped(&np->saddr))
1422 				ipv6_addr_set_v4mapped(htonl(INADDR_LOOPBACK),
1423 						       daddr);
1424 			break;
1425 		case AF_INET:
1426 			goto do_udp_sendmsg;
1427 		case AF_UNSPEC:
1428 			msg->msg_name = sin6 = NULL;
1429 			msg->msg_namelen = addr_len = 0;
1430 			daddr = NULL;
1431 			break;
1432 		default:
1433 			return -EINVAL;
1434 		}
1435 	} else if (!READ_ONCE(up->pending)) {
1436 		if (sk->sk_state != TCP_ESTABLISHED)
1437 			return -EDESTADDRREQ;
1438 		daddr = &sk->sk_v6_daddr;
1439 	} else
1440 		daddr = NULL;
1441 
1442 	if (daddr) {
1443 		if (ipv6_addr_v4mapped(daddr)) {
1444 			struct sockaddr_in sin;
1445 			sin.sin_family = AF_INET;
1446 			sin.sin_port = sin6 ? sin6->sin6_port : inet->inet_dport;
1447 			sin.sin_addr.s_addr = daddr->s6_addr32[3];
1448 			msg->msg_name = &sin;
1449 			msg->msg_namelen = sizeof(sin);
1450 do_udp_sendmsg:
1451 			err = ipv6_only_sock(sk) ?
1452 				-ENETUNREACH : udp_sendmsg(sk, msg, len);
1453 			msg->msg_name = sin6;
1454 			msg->msg_namelen = addr_len;
1455 			return err;
1456 		}
1457 	}
1458 
1459 	/* Rough check on arithmetic overflow,
1460 	   better check is made in ip6_append_data().
1461 	   */
1462 	if (len > INT_MAX - sizeof(struct udphdr))
1463 		return -EMSGSIZE;
1464 
1465 	getfrag  =  is_udplite ?  udplite_getfrag : ip_generic_getfrag;
1466 	if (READ_ONCE(up->pending)) {
1467 		if (READ_ONCE(up->pending) == AF_INET)
1468 			return udp_sendmsg(sk, msg, len);
1469 		/*
1470 		 * There are pending frames.
1471 		 * The socket lock must be held while it's corked.
1472 		 */
1473 		lock_sock(sk);
1474 		if (likely(up->pending)) {
1475 			if (unlikely(up->pending != AF_INET6)) {
1476 				release_sock(sk);
1477 				return -EAFNOSUPPORT;
1478 			}
1479 			dst = NULL;
1480 			goto do_append_data;
1481 		}
1482 		release_sock(sk);
1483 	}
1484 	ulen += sizeof(struct udphdr);
1485 
1486 	memset(fl6, 0, sizeof(*fl6));
1487 
1488 	if (sin6) {
1489 		if (sin6->sin6_port == 0)
1490 			return -EINVAL;
1491 
1492 		fl6->fl6_dport = sin6->sin6_port;
1493 		daddr = &sin6->sin6_addr;
1494 
1495 		if (np->sndflow) {
1496 			fl6->flowlabel = sin6->sin6_flowinfo&IPV6_FLOWINFO_MASK;
1497 			if (fl6->flowlabel & IPV6_FLOWLABEL_MASK) {
1498 				flowlabel = fl6_sock_lookup(sk, fl6->flowlabel);
1499 				if (IS_ERR(flowlabel))
1500 					return -EINVAL;
1501 			}
1502 		}
1503 
1504 		/*
1505 		 * Otherwise it will be difficult to maintain
1506 		 * sk->sk_dst_cache.
1507 		 */
1508 		if (sk->sk_state == TCP_ESTABLISHED &&
1509 		    ipv6_addr_equal(daddr, &sk->sk_v6_daddr))
1510 			daddr = &sk->sk_v6_daddr;
1511 
1512 		if (addr_len >= sizeof(struct sockaddr_in6) &&
1513 		    sin6->sin6_scope_id &&
1514 		    __ipv6_addr_needs_scope_id(__ipv6_addr_type(daddr)))
1515 			fl6->flowi6_oif = sin6->sin6_scope_id;
1516 	} else {
1517 		if (sk->sk_state != TCP_ESTABLISHED)
1518 			return -EDESTADDRREQ;
1519 
1520 		fl6->fl6_dport = inet->inet_dport;
1521 		daddr = &sk->sk_v6_daddr;
1522 		fl6->flowlabel = np->flow_label;
1523 		connected = true;
1524 	}
1525 
1526 	if (!fl6->flowi6_oif)
1527 		fl6->flowi6_oif = READ_ONCE(sk->sk_bound_dev_if);
1528 
1529 	if (!fl6->flowi6_oif)
1530 		fl6->flowi6_oif = np->sticky_pktinfo.ipi6_ifindex;
1531 
1532 	fl6->flowi6_uid = sk->sk_uid;
1533 
1534 	if (msg->msg_controllen) {
1535 		opt = &opt_space;
1536 		memset(opt, 0, sizeof(struct ipv6_txoptions));
1537 		opt->tot_len = sizeof(*opt);
1538 		ipc6.opt = opt;
1539 
1540 		err = udp_cmsg_send(sk, msg, &ipc6.gso_size);
1541 		if (err > 0) {
1542 			err = ip6_datagram_send_ctl(sock_net(sk), sk, msg, fl6,
1543 						    &ipc6);
1544 			connected = false;
1545 		}
1546 		if (err < 0) {
1547 			fl6_sock_release(flowlabel);
1548 			return err;
1549 		}
1550 		if ((fl6->flowlabel&IPV6_FLOWLABEL_MASK) && !flowlabel) {
1551 			flowlabel = fl6_sock_lookup(sk, fl6->flowlabel);
1552 			if (IS_ERR(flowlabel))
1553 				return -EINVAL;
1554 		}
1555 		if (!(opt->opt_nflen|opt->opt_flen))
1556 			opt = NULL;
1557 	}
1558 	if (!opt) {
1559 		opt = txopt_get(np);
1560 		opt_to_free = opt;
1561 	}
1562 	if (flowlabel)
1563 		opt = fl6_merge_options(&opt_space, flowlabel, opt);
1564 	opt = ipv6_fixup_options(&opt_space, opt);
1565 	ipc6.opt = opt;
1566 
1567 	fl6->flowi6_proto = sk->sk_protocol;
1568 	fl6->flowi6_mark = ipc6.sockc.mark;
1569 	fl6->daddr = *daddr;
1570 	if (ipv6_addr_any(&fl6->saddr) && !ipv6_addr_any(&np->saddr))
1571 		fl6->saddr = np->saddr;
1572 	fl6->fl6_sport = inet->inet_sport;
1573 
1574 	if (cgroup_bpf_enabled(CGROUP_UDP6_SENDMSG) && !connected) {
1575 		err = BPF_CGROUP_RUN_PROG_UDP6_SENDMSG_LOCK(sk,
1576 					   (struct sockaddr *)sin6,
1577 					   &addr_len,
1578 					   &fl6->saddr);
1579 		if (err)
1580 			goto out_no_dst;
1581 		if (sin6) {
1582 			if (ipv6_addr_v4mapped(&sin6->sin6_addr)) {
1583 				/* BPF program rewrote IPv6-only by IPv4-mapped
1584 				 * IPv6. It's currently unsupported.
1585 				 */
1586 				err = -ENOTSUPP;
1587 				goto out_no_dst;
1588 			}
1589 			if (sin6->sin6_port == 0) {
1590 				/* BPF program set invalid port. Reject it. */
1591 				err = -EINVAL;
1592 				goto out_no_dst;
1593 			}
1594 			fl6->fl6_dport = sin6->sin6_port;
1595 			fl6->daddr = sin6->sin6_addr;
1596 		}
1597 	}
1598 
1599 	if (ipv6_addr_any(&fl6->daddr))
1600 		fl6->daddr.s6_addr[15] = 0x1; /* :: means loopback (BSD'ism) */
1601 
1602 	final_p = fl6_update_dst(fl6, opt, &final);
1603 	if (final_p)
1604 		connected = false;
1605 
1606 	if (!fl6->flowi6_oif && ipv6_addr_is_multicast(&fl6->daddr)) {
1607 		fl6->flowi6_oif = np->mcast_oif;
1608 		connected = false;
1609 	} else if (!fl6->flowi6_oif)
1610 		fl6->flowi6_oif = np->ucast_oif;
1611 
1612 	security_sk_classify_flow(sk, flowi6_to_flowi_common(fl6));
1613 
1614 	if (ipc6.tclass < 0)
1615 		ipc6.tclass = np->tclass;
1616 
1617 	fl6->flowlabel = ip6_make_flowinfo(ipc6.tclass, fl6->flowlabel);
1618 
1619 	dst = ip6_sk_dst_lookup_flow(sk, fl6, final_p, connected);
1620 	if (IS_ERR(dst)) {
1621 		err = PTR_ERR(dst);
1622 		dst = NULL;
1623 		goto out;
1624 	}
1625 
1626 	if (ipc6.hlimit < 0)
1627 		ipc6.hlimit = ip6_sk_dst_hoplimit(np, fl6, dst);
1628 
1629 	if (msg->msg_flags&MSG_CONFIRM)
1630 		goto do_confirm;
1631 back_from_confirm:
1632 
1633 	/* Lockless fast path for the non-corking case */
1634 	if (!corkreq) {
1635 		struct sk_buff *skb;
1636 
1637 		skb = ip6_make_skb(sk, getfrag, msg, ulen,
1638 				   sizeof(struct udphdr), &ipc6,
1639 				   dst_rt6_info(dst),
1640 				   msg->msg_flags, &cork);
1641 		err = PTR_ERR(skb);
1642 		if (!IS_ERR_OR_NULL(skb))
1643 			err = udp_v6_send_skb(skb, fl6, &cork.base);
1644 		/* ip6_make_skb steals dst reference */
1645 		goto out_no_dst;
1646 	}
1647 
1648 	lock_sock(sk);
1649 	if (unlikely(up->pending)) {
1650 		/* The socket is already corked while preparing it. */
1651 		/* ... which is an evident application bug. --ANK */
1652 		release_sock(sk);
1653 
1654 		net_dbg_ratelimited("udp cork app bug 2\n");
1655 		err = -EINVAL;
1656 		goto out;
1657 	}
1658 
1659 	WRITE_ONCE(up->pending, AF_INET6);
1660 
1661 do_append_data:
1662 	if (ipc6.dontfrag < 0)
1663 		ipc6.dontfrag = np->dontfrag;
1664 	up->len += ulen;
1665 	err = ip6_append_data(sk, getfrag, msg, ulen, sizeof(struct udphdr),
1666 			      &ipc6, fl6, dst_rt6_info(dst),
1667 			      corkreq ? msg->msg_flags|MSG_MORE : msg->msg_flags);
1668 	if (err)
1669 		udp_v6_flush_pending_frames(sk);
1670 	else if (!corkreq)
1671 		err = udp_v6_push_pending_frames(sk);
1672 	else if (unlikely(skb_queue_empty(&sk->sk_write_queue)))
1673 		WRITE_ONCE(up->pending, 0);
1674 
1675 	if (err > 0)
1676 		err = np->recverr ? net_xmit_errno(err) : 0;
1677 	release_sock(sk);
1678 
1679 out:
1680 	dst_release(dst);
1681 out_no_dst:
1682 	fl6_sock_release(flowlabel);
1683 	txopt_put(opt_to_free);
1684 	if (!err)
1685 		return len;
1686 	/*
1687 	 * ENOBUFS = no kernel mem, SOCK_NOSPACE = no sndbuf space.  Reporting
1688 	 * ENOBUFS might not be good (it's not tunable per se), but otherwise
1689 	 * we don't have a good statistic (IpOutDiscards but it can be too many
1690 	 * things).  We could add another new stat but at least for now that
1691 	 * seems like overkill.
1692 	 */
1693 	if (err == -ENOBUFS || test_bit(SOCK_NOSPACE, &sk->sk_socket->flags)) {
1694 		UDP6_INC_STATS(sock_net(sk),
1695 			       UDP_MIB_SNDBUFERRORS, is_udplite);
1696 	}
1697 	return err;
1698 
1699 do_confirm:
1700 	if (msg->msg_flags & MSG_PROBE)
1701 		dst_confirm_neigh(dst, &fl6->daddr);
1702 	if (!(msg->msg_flags&MSG_PROBE) || len)
1703 		goto back_from_confirm;
1704 	err = 0;
1705 	goto out;
1706 }
1707 EXPORT_SYMBOL(udpv6_sendmsg);
1708 
udpv6_splice_eof(struct socket * sock)1709 static void udpv6_splice_eof(struct socket *sock)
1710 {
1711 	struct sock *sk = sock->sk;
1712 	struct udp_sock *up = udp_sk(sk);
1713 
1714 	if (!READ_ONCE(up->pending) || udp_test_bit(CORK, sk))
1715 		return;
1716 
1717 	lock_sock(sk);
1718 	if (up->pending && !udp_test_bit(CORK, sk))
1719 		udp_v6_push_pending_frames(sk);
1720 	release_sock(sk);
1721 }
1722 
udpv6_destroy_sock(struct sock * sk)1723 void udpv6_destroy_sock(struct sock *sk)
1724 {
1725 	struct udp_sock *up = udp_sk(sk);
1726 	lock_sock(sk);
1727 
1728 	/* protects from races with udp_abort() */
1729 	sock_set_flag(sk, SOCK_DEAD);
1730 	udp_v6_flush_pending_frames(sk);
1731 	release_sock(sk);
1732 
1733 	if (static_branch_unlikely(&udpv6_encap_needed_key)) {
1734 		if (up->encap_type) {
1735 			void (*encap_destroy)(struct sock *sk);
1736 			encap_destroy = READ_ONCE(up->encap_destroy);
1737 			if (encap_destroy)
1738 				encap_destroy(sk);
1739 		}
1740 		if (udp_test_bit(ENCAP_ENABLED, sk)) {
1741 			static_branch_dec(&udpv6_encap_needed_key);
1742 			udp_encap_disable();
1743 		}
1744 	}
1745 }
1746 
1747 /*
1748  *	Socket option code for UDP
1749  */
udpv6_setsockopt(struct sock * sk,int level,int optname,sockptr_t optval,unsigned int optlen)1750 int udpv6_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval,
1751 		     unsigned int optlen)
1752 {
1753 	if (level == SOL_UDP  ||  level == SOL_UDPLITE || level == SOL_SOCKET)
1754 		return udp_lib_setsockopt(sk, level, optname,
1755 					  optval, optlen,
1756 					  udp_v6_push_pending_frames);
1757 	return ipv6_setsockopt(sk, level, optname, optval, optlen);
1758 }
1759 
udpv6_getsockopt(struct sock * sk,int level,int optname,char __user * optval,int __user * optlen)1760 int udpv6_getsockopt(struct sock *sk, int level, int optname,
1761 		     char __user *optval, int __user *optlen)
1762 {
1763 	if (level == SOL_UDP  ||  level == SOL_UDPLITE)
1764 		return udp_lib_getsockopt(sk, level, optname, optval, optlen);
1765 	return ipv6_getsockopt(sk, level, optname, optval, optlen);
1766 }
1767 
1768 static const struct inet6_protocol udpv6_protocol = {
1769 	.handler	=	udpv6_rcv,
1770 	.err_handler	=	udpv6_err,
1771 	.flags		=	INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
1772 };
1773 
1774 /* ------------------------------------------------------------------------ */
1775 #ifdef CONFIG_PROC_FS
udp6_seq_show(struct seq_file * seq,void * v)1776 int udp6_seq_show(struct seq_file *seq, void *v)
1777 {
1778 	if (v == SEQ_START_TOKEN) {
1779 		seq_puts(seq, IPV6_SEQ_DGRAM_HEADER);
1780 	} else {
1781 		int bucket = ((struct udp_iter_state *)seq->private)->bucket;
1782 		const struct inet_sock *inet = inet_sk((const struct sock *)v);
1783 		__u16 srcp = ntohs(inet->inet_sport);
1784 		__u16 destp = ntohs(inet->inet_dport);
1785 		__ip6_dgram_sock_seq_show(seq, v, srcp, destp,
1786 					  udp_rqueue_get(v), bucket);
1787 	}
1788 	return 0;
1789 }
1790 
1791 const struct seq_operations udp6_seq_ops = {
1792 	.start		= udp_seq_start,
1793 	.next		= udp_seq_next,
1794 	.stop		= udp_seq_stop,
1795 	.show		= udp6_seq_show,
1796 };
1797 EXPORT_SYMBOL(udp6_seq_ops);
1798 
1799 static struct udp_seq_afinfo udp6_seq_afinfo = {
1800 	.family		= AF_INET6,
1801 	.udp_table	= NULL,
1802 };
1803 
udp6_proc_init(struct net * net)1804 int __net_init udp6_proc_init(struct net *net)
1805 {
1806 	if (!proc_create_net_data("udp6", 0444, net->proc_net, &udp6_seq_ops,
1807 			sizeof(struct udp_iter_state), &udp6_seq_afinfo))
1808 		return -ENOMEM;
1809 	return 0;
1810 }
1811 
udp6_proc_exit(struct net * net)1812 void udp6_proc_exit(struct net *net)
1813 {
1814 	remove_proc_entry("udp6", net->proc_net);
1815 }
1816 #endif /* CONFIG_PROC_FS */
1817 
1818 /* ------------------------------------------------------------------------ */
1819 
1820 struct proto udpv6_prot = {
1821 	.name			= "UDPv6",
1822 	.owner			= THIS_MODULE,
1823 	.close			= udp_lib_close,
1824 	.pre_connect		= udpv6_pre_connect,
1825 	.connect		= ip6_datagram_connect,
1826 	.disconnect		= udp_disconnect,
1827 	.ioctl			= udp_ioctl,
1828 	.init			= udpv6_init_sock,
1829 	.destroy		= udpv6_destroy_sock,
1830 	.setsockopt		= udpv6_setsockopt,
1831 	.getsockopt		= udpv6_getsockopt,
1832 	.sendmsg		= udpv6_sendmsg,
1833 	.recvmsg		= udpv6_recvmsg,
1834 	.splice_eof		= udpv6_splice_eof,
1835 	.release_cb		= ip6_datagram_release_cb,
1836 	.hash			= udp_lib_hash,
1837 	.unhash			= udp_lib_unhash,
1838 	.rehash			= udp_v6_rehash,
1839 	.get_port		= udp_v6_get_port,
1840 	.put_port		= udp_lib_unhash,
1841 #ifdef CONFIG_BPF_SYSCALL
1842 	.psock_update_sk_prot	= udp_bpf_update_proto,
1843 #endif
1844 
1845 	.memory_allocated	= &udp_memory_allocated,
1846 	.per_cpu_fw_alloc	= &udp_memory_per_cpu_fw_alloc,
1847 
1848 	.sysctl_mem		= sysctl_udp_mem,
1849 	.sysctl_wmem_offset     = offsetof(struct net, ipv4.sysctl_udp_wmem_min),
1850 	.sysctl_rmem_offset     = offsetof(struct net, ipv4.sysctl_udp_rmem_min),
1851 	.obj_size		= sizeof(struct udp6_sock),
1852 	.ipv6_pinfo_offset = offsetof(struct udp6_sock, inet6),
1853 	.h.udp_table		= NULL,
1854 	.diag_destroy		= udp_abort,
1855 };
1856 
1857 static struct inet_protosw udpv6_protosw = {
1858 	.type =      SOCK_DGRAM,
1859 	.protocol =  IPPROTO_UDP,
1860 	.prot =      &udpv6_prot,
1861 	.ops =       &inet6_dgram_ops,
1862 	.flags =     INET_PROTOSW_PERMANENT,
1863 };
1864 
udpv6_init(void)1865 int __init udpv6_init(void)
1866 {
1867 	int ret;
1868 
1869 	ret = inet6_add_protocol(&udpv6_protocol, IPPROTO_UDP);
1870 	if (ret)
1871 		goto out;
1872 
1873 	ret = inet6_register_protosw(&udpv6_protosw);
1874 	if (ret)
1875 		goto out_udpv6_protocol;
1876 out:
1877 	return ret;
1878 
1879 out_udpv6_protocol:
1880 	inet6_del_protocol(&udpv6_protocol, IPPROTO_UDP);
1881 	goto out;
1882 }
1883 
udpv6_exit(void)1884 void udpv6_exit(void)
1885 {
1886 	inet6_unregister_protosw(&udpv6_protosw);
1887 	inet6_del_protocol(&udpv6_protocol, IPPROTO_UDP);
1888 }
1889