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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/seg6.h>
44 #include <net/tcp_states.h>
45 #include <net/ip6_checksum.h>
46 #include <net/ip6_tunnel.h>
47 #include <net/xfrm.h>
48 #include <net/inet_hashtables.h>
49 #include <net/inet6_hashtables.h>
50 #include <net/busy_poll.h>
51 #include <net/sock_reuseport.h>
52 
53 #include <linux/proc_fs.h>
54 #include <linux/seq_file.h>
55 #include <trace/events/skb.h>
56 #include "udp_impl.h"
57 
udpv6_destruct_sock(struct sock * sk)58 static void udpv6_destruct_sock(struct sock *sk)
59 {
60 	udp_destruct_common(sk);
61 	inet6_sock_destruct(sk);
62 }
63 
udpv6_init_sock(struct sock * sk)64 int udpv6_init_sock(struct sock *sk)
65 {
66 	skb_queue_head_init(&udp_sk(sk)->reader_queue);
67 	sk->sk_destruct = udpv6_destruct_sock;
68 	return 0;
69 }
70 
udp6_ehashfn(const struct net * net,const struct in6_addr * laddr,const u16 lport,const struct in6_addr * faddr,const __be16 fport)71 static u32 udp6_ehashfn(const struct net *net,
72 			const struct in6_addr *laddr,
73 			const u16 lport,
74 			const struct in6_addr *faddr,
75 			const __be16 fport)
76 {
77 	static u32 udp6_ehash_secret __read_mostly;
78 	static u32 udp_ipv6_hash_secret __read_mostly;
79 
80 	u32 lhash, fhash;
81 
82 	net_get_random_once(&udp6_ehash_secret,
83 			    sizeof(udp6_ehash_secret));
84 	net_get_random_once(&udp_ipv6_hash_secret,
85 			    sizeof(udp_ipv6_hash_secret));
86 
87 	lhash = (__force u32)laddr->s6_addr32[3];
88 	fhash = __ipv6_addr_jhash(faddr, udp_ipv6_hash_secret);
89 
90 	return __inet6_ehashfn(lhash, lport, fhash, fport,
91 			       udp6_ehash_secret + net_hash_mix(net));
92 }
93 
udp_v6_get_port(struct sock * sk,unsigned short snum)94 int udp_v6_get_port(struct sock *sk, unsigned short snum)
95 {
96 	unsigned int hash2_nulladdr =
97 		ipv6_portaddr_hash(sock_net(sk), &in6addr_any, snum);
98 	unsigned int hash2_partial =
99 		ipv6_portaddr_hash(sock_net(sk), &sk->sk_v6_rcv_saddr, 0);
100 
101 	/* precompute partial secondary hash */
102 	udp_sk(sk)->udp_portaddr_hash = hash2_partial;
103 	return udp_lib_get_port(sk, snum, hash2_nulladdr);
104 }
105 
udp_v6_rehash(struct sock * sk)106 void udp_v6_rehash(struct sock *sk)
107 {
108 	u16 new_hash = ipv6_portaddr_hash(sock_net(sk),
109 					  &sk->sk_v6_rcv_saddr,
110 					  inet_sk(sk)->inet_num);
111 
112 	udp_lib_rehash(sk, new_hash);
113 }
114 
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)115 static int compute_score(struct sock *sk, struct net *net,
116 			 const struct in6_addr *saddr, __be16 sport,
117 			 const struct in6_addr *daddr, unsigned short hnum,
118 			 int dif, int sdif)
119 {
120 	int score;
121 	struct inet_sock *inet;
122 	bool dev_match;
123 
124 	if (!net_eq(sock_net(sk), net) ||
125 	    udp_sk(sk)->udp_port_hash != hnum ||
126 	    sk->sk_family != PF_INET6)
127 		return -1;
128 
129 	if (!ipv6_addr_equal(&sk->sk_v6_rcv_saddr, daddr))
130 		return -1;
131 
132 	score = 0;
133 	inet = inet_sk(sk);
134 
135 	if (inet->inet_dport) {
136 		if (inet->inet_dport != sport)
137 			return -1;
138 		score++;
139 	}
140 
141 	if (!ipv6_addr_any(&sk->sk_v6_daddr)) {
142 		if (!ipv6_addr_equal(&sk->sk_v6_daddr, saddr))
143 			return -1;
144 		score++;
145 	}
146 
147 	dev_match = udp_sk_bound_dev_eq(net, sk->sk_bound_dev_if, dif, sdif);
148 	if (!dev_match)
149 		return -1;
150 	if (sk->sk_bound_dev_if)
151 		score++;
152 
153 	if (READ_ONCE(sk->sk_incoming_cpu) == raw_smp_processor_id())
154 		score++;
155 
156 	return score;
157 }
158 
lookup_reuseport(struct net * net,struct sock * sk,struct sk_buff * skb,const struct in6_addr * saddr,__be16 sport,const struct in6_addr * daddr,unsigned int hnum)159 static struct sock *lookup_reuseport(struct net *net, struct sock *sk,
160 				     struct sk_buff *skb,
161 				     const struct in6_addr *saddr,
162 				     __be16 sport,
163 				     const struct in6_addr *daddr,
164 				     unsigned int hnum)
165 {
166 	struct sock *reuse_sk = NULL;
167 	u32 hash;
168 
169 	if (sk->sk_reuseport && sk->sk_state != TCP_ESTABLISHED) {
170 		hash = udp6_ehashfn(net, daddr, hnum, saddr, sport);
171 		reuse_sk = reuseport_select_sock(sk, hash, skb,
172 						 sizeof(struct udphdr));
173 	}
174 	return reuse_sk;
175 }
176 
177 /* 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)178 static struct sock *udp6_lib_lookup2(struct net *net,
179 		const struct in6_addr *saddr, __be16 sport,
180 		const struct in6_addr *daddr, unsigned int hnum,
181 		int dif, int sdif, struct udp_hslot *hslot2,
182 		struct sk_buff *skb)
183 {
184 	struct sock *sk, *result;
185 	int score, badness;
186 
187 	result = NULL;
188 	badness = -1;
189 	udp_portaddr_for_each_entry_rcu(sk, &hslot2->head) {
190 		score = compute_score(sk, net, saddr, sport,
191 				      daddr, hnum, dif, sdif);
192 		if (score > badness) {
193 			badness = score;
194 			result = lookup_reuseport(net, sk, skb, saddr, sport, daddr, hnum);
195 			if (!result) {
196 				result = sk;
197 				continue;
198 			}
199 
200 			/* Fall back to scoring if group has connections */
201 			if (!reuseport_has_conns(sk))
202 				return result;
203 
204 			/* Reuseport logic returned an error, keep original score. */
205 			if (IS_ERR(result))
206 				continue;
207 
208 			badness = compute_score(sk, net, saddr, sport,
209 						daddr, hnum, dif, sdif);
210 		}
211 	}
212 	return result;
213 }
214 
udp6_lookup_run_bpf(struct net * net,struct udp_table * udptable,struct sk_buff * skb,const struct in6_addr * saddr,__be16 sport,const struct in6_addr * daddr,u16 hnum)215 static inline struct sock *udp6_lookup_run_bpf(struct net *net,
216 					       struct udp_table *udptable,
217 					       struct sk_buff *skb,
218 					       const struct in6_addr *saddr,
219 					       __be16 sport,
220 					       const struct in6_addr *daddr,
221 					       u16 hnum)
222 {
223 	struct sock *sk, *reuse_sk;
224 	bool no_reuseport;
225 
226 	if (udptable != &udp_table)
227 		return NULL; /* only UDP is supported */
228 
229 	no_reuseport = bpf_sk_lookup_run_v6(net, IPPROTO_UDP,
230 					    saddr, sport, daddr, hnum, &sk);
231 	if (no_reuseport || IS_ERR_OR_NULL(sk))
232 		return sk;
233 
234 	reuse_sk = lookup_reuseport(net, sk, skb, saddr, sport, daddr, hnum);
235 	if (reuse_sk)
236 		sk = reuse_sk;
237 	return sk;
238 }
239 
240 /* 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)241 struct sock *__udp6_lib_lookup(struct net *net,
242 			       const struct in6_addr *saddr, __be16 sport,
243 			       const struct in6_addr *daddr, __be16 dport,
244 			       int dif, int sdif, struct udp_table *udptable,
245 			       struct sk_buff *skb)
246 {
247 	unsigned short hnum = ntohs(dport);
248 	unsigned int hash2, slot2;
249 	struct udp_hslot *hslot2;
250 	struct sock *result, *sk;
251 
252 	hash2 = ipv6_portaddr_hash(net, daddr, hnum);
253 	slot2 = hash2 & udptable->mask;
254 	hslot2 = &udptable->hash2[slot2];
255 
256 	/* Lookup connected or non-wildcard sockets */
257 	result = udp6_lib_lookup2(net, saddr, sport,
258 				  daddr, hnum, dif, sdif,
259 				  hslot2, skb);
260 	if (!IS_ERR_OR_NULL(result) && result->sk_state == TCP_ESTABLISHED)
261 		goto done;
262 
263 	/* Lookup redirect from BPF */
264 	if (static_branch_unlikely(&bpf_sk_lookup_enabled)) {
265 		sk = udp6_lookup_run_bpf(net, udptable, skb,
266 					 saddr, sport, daddr, hnum);
267 		if (sk) {
268 			result = sk;
269 			goto done;
270 		}
271 	}
272 
273 	/* Got non-wildcard socket or error on first lookup */
274 	if (result)
275 		goto done;
276 
277 	/* Lookup wildcard sockets */
278 	hash2 = ipv6_portaddr_hash(net, &in6addr_any, hnum);
279 	slot2 = hash2 & udptable->mask;
280 	hslot2 = &udptable->hash2[slot2];
281 
282 	result = udp6_lib_lookup2(net, saddr, sport,
283 				  &in6addr_any, hnum, dif, sdif,
284 				  hslot2, skb);
285 done:
286 	if (IS_ERR(result))
287 		return NULL;
288 	return result;
289 }
290 EXPORT_SYMBOL_GPL(__udp6_lib_lookup);
291 
__udp6_lib_lookup_skb(struct sk_buff * skb,__be16 sport,__be16 dport,struct udp_table * udptable)292 static struct sock *__udp6_lib_lookup_skb(struct sk_buff *skb,
293 					  __be16 sport, __be16 dport,
294 					  struct udp_table *udptable)
295 {
296 	const struct ipv6hdr *iph = ipv6_hdr(skb);
297 
298 	return __udp6_lib_lookup(dev_net(skb->dev), &iph->saddr, sport,
299 				 &iph->daddr, dport, inet6_iif(skb),
300 				 inet6_sdif(skb), udptable, skb);
301 }
302 
udp6_lib_lookup_skb(const struct sk_buff * skb,__be16 sport,__be16 dport)303 struct sock *udp6_lib_lookup_skb(const struct sk_buff *skb,
304 				 __be16 sport, __be16 dport)
305 {
306 	const struct ipv6hdr *iph = ipv6_hdr(skb);
307 
308 	return __udp6_lib_lookup(dev_net(skb->dev), &iph->saddr, sport,
309 				 &iph->daddr, dport, inet6_iif(skb),
310 				 inet6_sdif(skb), &udp_table, NULL);
311 }
312 
313 /* Must be called under rcu_read_lock().
314  * Does increment socket refcount.
315  */
316 #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)317 struct sock *udp6_lib_lookup(struct net *net, const struct in6_addr *saddr, __be16 sport,
318 			     const struct in6_addr *daddr, __be16 dport, int dif)
319 {
320 	struct sock *sk;
321 
322 	sk =  __udp6_lib_lookup(net, saddr, sport, daddr, dport,
323 				dif, 0, &udp_table, NULL);
324 	if (sk && !refcount_inc_not_zero(&sk->sk_refcnt))
325 		sk = NULL;
326 	return sk;
327 }
328 EXPORT_SYMBOL_GPL(udp6_lib_lookup);
329 #endif
330 
331 /* do not use the scratch area len for jumbogram: their length execeeds the
332  * scratch area space; note that the IP6CB flags is still in the first
333  * cacheline, so checking for jumbograms is cheap
334  */
udp6_skb_len(struct sk_buff * skb)335 static int udp6_skb_len(struct sk_buff *skb)
336 {
337 	return unlikely(inet6_is_jumbogram(skb)) ? skb->len : udp_skb_len(skb);
338 }
339 
340 /*
341  *	This should be easy, if there is something there we
342  *	return it, otherwise we block.
343  */
344 
udpv6_recvmsg(struct sock * sk,struct msghdr * msg,size_t len,int noblock,int flags,int * addr_len)345 int udpv6_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
346 		  int noblock, int flags, int *addr_len)
347 {
348 	struct ipv6_pinfo *np = inet6_sk(sk);
349 	struct inet_sock *inet = inet_sk(sk);
350 	struct sk_buff *skb;
351 	unsigned int ulen, copied;
352 	int off, err, peeking = flags & MSG_PEEK;
353 	int is_udplite = IS_UDPLITE(sk);
354 	struct udp_mib __percpu *mib;
355 	bool checksum_valid = false;
356 	int is_udp4;
357 
358 	if (flags & MSG_ERRQUEUE)
359 		return ipv6_recv_error(sk, msg, len, addr_len);
360 
361 	if (np->rxpmtu && np->rxopt.bits.rxpmtu)
362 		return ipv6_recv_rxpmtu(sk, msg, len, addr_len);
363 
364 try_again:
365 	off = sk_peek_offset(sk, flags);
366 	skb = __skb_recv_udp(sk, flags, noblock, &off, &err);
367 	if (!skb)
368 		return err;
369 
370 	ulen = udp6_skb_len(skb);
371 	copied = len;
372 	if (copied > ulen - off)
373 		copied = ulen - off;
374 	else if (copied < ulen)
375 		msg->msg_flags |= MSG_TRUNC;
376 
377 	is_udp4 = (skb->protocol == htons(ETH_P_IP));
378 	mib = __UDPX_MIB(sk, is_udp4);
379 
380 	/*
381 	 * If checksum is needed at all, try to do it while copying the
382 	 * data.  If the data is truncated, or if we only want a partial
383 	 * coverage checksum (UDP-Lite), do it before the copy.
384 	 */
385 
386 	if (copied < ulen || peeking ||
387 	    (is_udplite && UDP_SKB_CB(skb)->partial_cov)) {
388 		checksum_valid = udp_skb_csum_unnecessary(skb) ||
389 				!__udp_lib_checksum_complete(skb);
390 		if (!checksum_valid)
391 			goto csum_copy_err;
392 	}
393 
394 	if (checksum_valid || udp_skb_csum_unnecessary(skb)) {
395 		if (udp_skb_is_linear(skb))
396 			err = copy_linear_skb(skb, copied, off, &msg->msg_iter);
397 		else
398 			err = skb_copy_datagram_msg(skb, off, msg, copied);
399 	} else {
400 		err = skb_copy_and_csum_datagram_msg(skb, off, msg);
401 		if (err == -EINVAL)
402 			goto csum_copy_err;
403 	}
404 	if (unlikely(err)) {
405 		if (!peeking) {
406 			atomic_inc(&sk->sk_drops);
407 			SNMP_INC_STATS(mib, UDP_MIB_INERRORS);
408 		}
409 		kfree_skb(skb);
410 		return err;
411 	}
412 	if (!peeking)
413 		SNMP_INC_STATS(mib, UDP_MIB_INDATAGRAMS);
414 
415 	sock_recv_ts_and_drops(msg, sk, skb);
416 
417 	/* Copy the address. */
418 	if (msg->msg_name) {
419 		DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name);
420 		sin6->sin6_family = AF_INET6;
421 		sin6->sin6_port = udp_hdr(skb)->source;
422 		sin6->sin6_flowinfo = 0;
423 
424 		if (is_udp4) {
425 			ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr,
426 					       &sin6->sin6_addr);
427 			sin6->sin6_scope_id = 0;
428 		} else {
429 			sin6->sin6_addr = ipv6_hdr(skb)->saddr;
430 			sin6->sin6_scope_id =
431 				ipv6_iface_scope_id(&sin6->sin6_addr,
432 						    inet6_iif(skb));
433 		}
434 		*addr_len = sizeof(*sin6);
435 
436 		BPF_CGROUP_RUN_PROG_UDP6_RECVMSG_LOCK(sk,
437 						      (struct sockaddr *)sin6);
438 	}
439 
440 	if (udp_sk(sk)->gro_enabled)
441 		udp_cmsg_recv(msg, sk, skb);
442 
443 	if (np->rxopt.all)
444 		ip6_datagram_recv_common_ctl(sk, msg, skb);
445 
446 	if (is_udp4) {
447 		if (inet->cmsg_flags)
448 			ip_cmsg_recv_offset(msg, sk, skb,
449 					    sizeof(struct udphdr), off);
450 	} else {
451 		if (np->rxopt.all)
452 			ip6_datagram_recv_specific_ctl(sk, msg, skb);
453 	}
454 
455 	err = copied;
456 	if (flags & MSG_TRUNC)
457 		err = ulen;
458 
459 	skb_consume_udp(sk, skb, peeking ? -err : err);
460 	return err;
461 
462 csum_copy_err:
463 	if (!__sk_queue_drop_skb(sk, &udp_sk(sk)->reader_queue, skb, flags,
464 				 udp_skb_destructor)) {
465 		SNMP_INC_STATS(mib, UDP_MIB_CSUMERRORS);
466 		SNMP_INC_STATS(mib, UDP_MIB_INERRORS);
467 	}
468 	kfree_skb(skb);
469 
470 	/* starting over for a new packet, but check if we need to yield */
471 	cond_resched();
472 	msg->msg_flags &= ~MSG_TRUNC;
473 	goto try_again;
474 }
475 
476 DEFINE_STATIC_KEY_FALSE(udpv6_encap_needed_key);
udpv6_encap_enable(void)477 void udpv6_encap_enable(void)
478 {
479 	static_branch_inc(&udpv6_encap_needed_key);
480 }
481 EXPORT_SYMBOL(udpv6_encap_enable);
482 
483 /* Handler for tunnels with arbitrary destination ports: no socket lookup, go
484  * through error handlers in encapsulations looking for a match.
485  */
__udp6_lib_err_encap_no_sk(struct sk_buff * skb,struct inet6_skb_parm * opt,u8 type,u8 code,int offset,__be32 info)486 static int __udp6_lib_err_encap_no_sk(struct sk_buff *skb,
487 				      struct inet6_skb_parm *opt,
488 				      u8 type, u8 code, int offset, __be32 info)
489 {
490 	int i;
491 
492 	for (i = 0; i < MAX_IPTUN_ENCAP_OPS; i++) {
493 		int (*handler)(struct sk_buff *skb, struct inet6_skb_parm *opt,
494 			       u8 type, u8 code, int offset, __be32 info);
495 		const struct ip6_tnl_encap_ops *encap;
496 
497 		encap = rcu_dereference(ip6tun_encaps[i]);
498 		if (!encap)
499 			continue;
500 		handler = encap->err_handler;
501 		if (handler && !handler(skb, opt, type, code, offset, info))
502 			return 0;
503 	}
504 
505 	return -ENOENT;
506 }
507 
508 /* Try to match ICMP errors to UDP tunnels by looking up a socket without
509  * reversing source and destination port: this will match tunnels that force the
510  * same destination port on both endpoints (e.g. VXLAN, GENEVE). Note that
511  * lwtunnels might actually break this assumption by being configured with
512  * different destination ports on endpoints, in this case we won't be able to
513  * trace ICMP messages back to them.
514  *
515  * If this doesn't match any socket, probe tunnels with arbitrary destination
516  * ports (e.g. FoU, GUE): there, the receiving socket is useless, as the port
517  * we've sent packets to won't necessarily match the local destination port.
518  *
519  * Then ask the tunnel implementation to match the error against a valid
520  * association.
521  *
522  * Return an error if we can't find a match, the socket if we need further
523  * processing, zero otherwise.
524  */
__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)525 static struct sock *__udp6_lib_err_encap(struct net *net,
526 					 const struct ipv6hdr *hdr, int offset,
527 					 struct udphdr *uh,
528 					 struct udp_table *udptable,
529 					 struct sock *sk,
530 					 struct sk_buff *skb,
531 					 struct inet6_skb_parm *opt,
532 					 u8 type, u8 code, __be32 info)
533 {
534 	int (*lookup)(struct sock *sk, struct sk_buff *skb);
535 	int network_offset, transport_offset;
536 	struct udp_sock *up;
537 
538 	network_offset = skb_network_offset(skb);
539 	transport_offset = skb_transport_offset(skb);
540 
541 	/* Network header needs to point to the outer IPv6 header inside ICMP */
542 	skb_reset_network_header(skb);
543 
544 	/* Transport header needs to point to the UDP header */
545 	skb_set_transport_header(skb, offset);
546 
547 	if (sk) {
548 		up = udp_sk(sk);
549 
550 		lookup = READ_ONCE(up->encap_err_lookup);
551 		if (lookup && lookup(sk, skb))
552 			sk = NULL;
553 
554 		goto out;
555 	}
556 
557 	sk = __udp6_lib_lookup(net, &hdr->daddr, uh->source,
558 			       &hdr->saddr, uh->dest,
559 			       inet6_iif(skb), 0, udptable, skb);
560 	if (sk) {
561 		up = udp_sk(sk);
562 
563 		lookup = READ_ONCE(up->encap_err_lookup);
564 		if (!lookup || lookup(sk, skb))
565 			sk = NULL;
566 	}
567 
568 out:
569 	if (!sk) {
570 		sk = ERR_PTR(__udp6_lib_err_encap_no_sk(skb, opt, type, code,
571 							offset, info));
572 	}
573 
574 	skb_set_transport_header(skb, transport_offset);
575 	skb_set_network_header(skb, network_offset);
576 
577 	return sk;
578 }
579 
__udp6_lib_err(struct sk_buff * skb,struct inet6_skb_parm * opt,u8 type,u8 code,int offset,__be32 info,struct udp_table * udptable)580 int __udp6_lib_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
581 		   u8 type, u8 code, int offset, __be32 info,
582 		   struct udp_table *udptable)
583 {
584 	struct ipv6_pinfo *np;
585 	const struct ipv6hdr *hdr = (const struct ipv6hdr *)skb->data;
586 	const struct in6_addr *saddr = &hdr->saddr;
587 	const struct in6_addr *daddr = seg6_get_daddr(skb, opt) ? : &hdr->daddr;
588 	struct udphdr *uh = (struct udphdr *)(skb->data+offset);
589 	bool tunnel = false;
590 	struct sock *sk;
591 	int harderr;
592 	int err;
593 	struct net *net = dev_net(skb->dev);
594 
595 	sk = __udp6_lib_lookup(net, daddr, uh->dest, saddr, uh->source,
596 			       inet6_iif(skb), inet6_sdif(skb), udptable, NULL);
597 
598 	if (!sk || udp_sk(sk)->encap_type) {
599 		/* No socket for error: try tunnels before discarding */
600 		if (static_branch_unlikely(&udpv6_encap_needed_key)) {
601 			sk = __udp6_lib_err_encap(net, hdr, offset, uh,
602 						  udptable, sk, skb,
603 						  opt, type, code, info);
604 			if (!sk)
605 				return 0;
606 		} else
607 			sk = ERR_PTR(-ENOENT);
608 
609 		if (IS_ERR(sk)) {
610 			__ICMP6_INC_STATS(net, __in6_dev_get(skb->dev),
611 					  ICMP6_MIB_INERRORS);
612 			return PTR_ERR(sk);
613 		}
614 
615 		tunnel = true;
616 	}
617 
618 	harderr = icmpv6_err_convert(type, code, &err);
619 	np = inet6_sk(sk);
620 
621 	if (type == ICMPV6_PKT_TOOBIG) {
622 		if (!ip6_sk_accept_pmtu(sk))
623 			goto out;
624 		ip6_sk_update_pmtu(skb, sk, info);
625 		if (np->pmtudisc != IPV6_PMTUDISC_DONT)
626 			harderr = 1;
627 	}
628 	if (type == NDISC_REDIRECT) {
629 		if (tunnel) {
630 			ip6_redirect(skb, sock_net(sk), inet6_iif(skb),
631 				     sk->sk_mark, sk->sk_uid);
632 		} else {
633 			ip6_sk_redirect(skb, sk);
634 		}
635 		goto out;
636 	}
637 
638 	/* Tunnels don't have an application socket: don't pass errors back */
639 	if (tunnel) {
640 		if (udp_sk(sk)->encap_err_rcv)
641 			udp_sk(sk)->encap_err_rcv(sk, skb, offset);
642 		goto out;
643 	}
644 
645 	if (!np->recverr) {
646 		if (!harderr || sk->sk_state != TCP_ESTABLISHED)
647 			goto out;
648 	} else {
649 		ipv6_icmp_error(sk, skb, err, uh->dest, ntohl(info), (u8 *)(uh+1));
650 	}
651 
652 	sk->sk_err = err;
653 	sk_error_report(sk);
654 out:
655 	return 0;
656 }
657 
__udpv6_queue_rcv_skb(struct sock * sk,struct sk_buff * skb)658 static int __udpv6_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
659 {
660 	int rc;
661 
662 	if (!ipv6_addr_any(&sk->sk_v6_daddr)) {
663 		sock_rps_save_rxhash(sk, skb);
664 		sk_mark_napi_id(sk, skb);
665 		sk_incoming_cpu_update(sk);
666 	} else {
667 		sk_mark_napi_id_once(sk, skb);
668 	}
669 
670 	rc = __udp_enqueue_schedule_skb(sk, skb);
671 	if (rc < 0) {
672 		int is_udplite = IS_UDPLITE(sk);
673 
674 		/* Note that an ENOMEM error is charged twice */
675 		if (rc == -ENOMEM)
676 			UDP6_INC_STATS(sock_net(sk),
677 					 UDP_MIB_RCVBUFERRORS, is_udplite);
678 		else
679 			UDP6_INC_STATS(sock_net(sk),
680 				       UDP_MIB_MEMERRORS, is_udplite);
681 		UDP6_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
682 		kfree_skb(skb);
683 		return -1;
684 	}
685 
686 	return 0;
687 }
688 
udpv6_err(struct sk_buff * skb,struct inet6_skb_parm * opt,u8 type,u8 code,int offset,__be32 info)689 static __inline__ int udpv6_err(struct sk_buff *skb,
690 				struct inet6_skb_parm *opt, u8 type,
691 				u8 code, int offset, __be32 info)
692 {
693 	return __udp6_lib_err(skb, opt, type, code, offset, info, &udp_table);
694 }
695 
udpv6_queue_rcv_one_skb(struct sock * sk,struct sk_buff * skb)696 static int udpv6_queue_rcv_one_skb(struct sock *sk, struct sk_buff *skb)
697 {
698 	struct udp_sock *up = udp_sk(sk);
699 	int is_udplite = IS_UDPLITE(sk);
700 
701 	if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
702 		goto drop;
703 
704 	if (static_branch_unlikely(&udpv6_encap_needed_key) && up->encap_type) {
705 		int (*encap_rcv)(struct sock *sk, struct sk_buff *skb);
706 
707 		/*
708 		 * This is an encapsulation socket so pass the skb to
709 		 * the socket's udp_encap_rcv() hook. Otherwise, just
710 		 * fall through and pass this up the UDP socket.
711 		 * up->encap_rcv() returns the following value:
712 		 * =0 if skb was successfully passed to the encap
713 		 *    handler or was discarded by it.
714 		 * >0 if skb should be passed on to UDP.
715 		 * <0 if skb should be resubmitted as proto -N
716 		 */
717 
718 		/* if we're overly short, let UDP handle it */
719 		encap_rcv = READ_ONCE(up->encap_rcv);
720 		if (encap_rcv) {
721 			int ret;
722 
723 			/* Verify checksum before giving to encap */
724 			if (udp_lib_checksum_complete(skb))
725 				goto csum_error;
726 
727 			ret = encap_rcv(sk, skb);
728 			if (ret <= 0) {
729 				__UDP_INC_STATS(sock_net(sk),
730 						UDP_MIB_INDATAGRAMS,
731 						is_udplite);
732 				return -ret;
733 			}
734 		}
735 
736 		/* FALLTHROUGH -- it's a UDP Packet */
737 	}
738 
739 	/*
740 	 * UDP-Lite specific tests, ignored on UDP sockets (see net/ipv4/udp.c).
741 	 */
742 	if ((up->pcflag & UDPLITE_RECV_CC)  &&  UDP_SKB_CB(skb)->partial_cov) {
743 
744 		if (up->pcrlen == 0) {          /* full coverage was set  */
745 			net_dbg_ratelimited("UDPLITE6: partial coverage %d while full coverage %d requested\n",
746 					    UDP_SKB_CB(skb)->cscov, skb->len);
747 			goto drop;
748 		}
749 		if (UDP_SKB_CB(skb)->cscov  <  up->pcrlen) {
750 			net_dbg_ratelimited("UDPLITE6: coverage %d too small, need min %d\n",
751 					    UDP_SKB_CB(skb)->cscov, up->pcrlen);
752 			goto drop;
753 		}
754 	}
755 
756 	prefetch(&sk->sk_rmem_alloc);
757 	if (rcu_access_pointer(sk->sk_filter) &&
758 	    udp_lib_checksum_complete(skb))
759 		goto csum_error;
760 
761 	if (sk_filter_trim_cap(sk, skb, sizeof(struct udphdr)))
762 		goto drop;
763 
764 	udp_csum_pull_header(skb);
765 
766 	skb_dst_drop(skb);
767 
768 	return __udpv6_queue_rcv_skb(sk, skb);
769 
770 csum_error:
771 	__UDP6_INC_STATS(sock_net(sk), UDP_MIB_CSUMERRORS, is_udplite);
772 drop:
773 	__UDP6_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
774 	atomic_inc(&sk->sk_drops);
775 	kfree_skb(skb);
776 	return -1;
777 }
778 
udpv6_queue_rcv_skb(struct sock * sk,struct sk_buff * skb)779 static int udpv6_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
780 {
781 	struct sk_buff *next, *segs;
782 	int ret;
783 
784 	if (likely(!udp_unexpected_gso(sk, skb)))
785 		return udpv6_queue_rcv_one_skb(sk, skb);
786 
787 	__skb_push(skb, -skb_mac_offset(skb));
788 	segs = udp_rcv_segment(sk, skb, false);
789 	skb_list_walk_safe(segs, skb, next) {
790 		__skb_pull(skb, skb_transport_offset(skb));
791 
792 		udp_post_segment_fix_csum(skb);
793 		ret = udpv6_queue_rcv_one_skb(sk, skb);
794 		if (ret > 0)
795 			ip6_protocol_deliver_rcu(dev_net(skb->dev), skb, ret,
796 						 true);
797 	}
798 	return 0;
799 }
800 
__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)801 static bool __udp_v6_is_mcast_sock(struct net *net, struct sock *sk,
802 				   __be16 loc_port, const struct in6_addr *loc_addr,
803 				   __be16 rmt_port, const struct in6_addr *rmt_addr,
804 				   int dif, int sdif, unsigned short hnum)
805 {
806 	struct inet_sock *inet = inet_sk(sk);
807 
808 	if (!net_eq(sock_net(sk), net))
809 		return false;
810 
811 	if (udp_sk(sk)->udp_port_hash != hnum ||
812 	    sk->sk_family != PF_INET6 ||
813 	    (inet->inet_dport && inet->inet_dport != rmt_port) ||
814 	    (!ipv6_addr_any(&sk->sk_v6_daddr) &&
815 		    !ipv6_addr_equal(&sk->sk_v6_daddr, rmt_addr)) ||
816 	    !udp_sk_bound_dev_eq(net, sk->sk_bound_dev_if, dif, sdif) ||
817 	    (!ipv6_addr_any(&sk->sk_v6_rcv_saddr) &&
818 		    !ipv6_addr_equal(&sk->sk_v6_rcv_saddr, loc_addr)))
819 		return false;
820 	if (!inet6_mc_check(sk, loc_addr, rmt_addr))
821 		return false;
822 	return true;
823 }
824 
udp6_csum_zero_error(struct sk_buff * skb)825 static void udp6_csum_zero_error(struct sk_buff *skb)
826 {
827 	/* RFC 2460 section 8.1 says that we SHOULD log
828 	 * this error. Well, it is reasonable.
829 	 */
830 	net_dbg_ratelimited("IPv6: udp checksum is 0 for [%pI6c]:%u->[%pI6c]:%u\n",
831 			    &ipv6_hdr(skb)->saddr, ntohs(udp_hdr(skb)->source),
832 			    &ipv6_hdr(skb)->daddr, ntohs(udp_hdr(skb)->dest));
833 }
834 
835 /*
836  * Note: called only from the BH handler context,
837  * so we don't need to lock the hashes.
838  */
__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)839 static int __udp6_lib_mcast_deliver(struct net *net, struct sk_buff *skb,
840 		const struct in6_addr *saddr, const struct in6_addr *daddr,
841 		struct udp_table *udptable, int proto)
842 {
843 	struct sock *sk, *first = NULL;
844 	const struct udphdr *uh = udp_hdr(skb);
845 	unsigned short hnum = ntohs(uh->dest);
846 	struct udp_hslot *hslot = udp_hashslot(udptable, net, hnum);
847 	unsigned int offset = offsetof(typeof(*sk), sk_node);
848 	unsigned int hash2 = 0, hash2_any = 0, use_hash2 = (hslot->count > 10);
849 	int dif = inet6_iif(skb);
850 	int sdif = inet6_sdif(skb);
851 	struct hlist_node *node;
852 	struct sk_buff *nskb;
853 
854 	if (use_hash2) {
855 		hash2_any = ipv6_portaddr_hash(net, &in6addr_any, hnum) &
856 			    udptable->mask;
857 		hash2 = ipv6_portaddr_hash(net, daddr, hnum) & udptable->mask;
858 start_lookup:
859 		hslot = &udptable->hash2[hash2];
860 		offset = offsetof(typeof(*sk), __sk_common.skc_portaddr_node);
861 	}
862 
863 	sk_for_each_entry_offset_rcu(sk, node, &hslot->head, offset) {
864 		if (!__udp_v6_is_mcast_sock(net, sk, uh->dest, daddr,
865 					    uh->source, saddr, dif, sdif,
866 					    hnum))
867 			continue;
868 		/* If zero checksum and no_check is not on for
869 		 * the socket then skip it.
870 		 */
871 		if (!uh->check && !udp_sk(sk)->no_check6_rx)
872 			continue;
873 		if (!first) {
874 			first = sk;
875 			continue;
876 		}
877 		nskb = skb_clone(skb, GFP_ATOMIC);
878 		if (unlikely(!nskb)) {
879 			atomic_inc(&sk->sk_drops);
880 			__UDP6_INC_STATS(net, UDP_MIB_RCVBUFERRORS,
881 					 IS_UDPLITE(sk));
882 			__UDP6_INC_STATS(net, UDP_MIB_INERRORS,
883 					 IS_UDPLITE(sk));
884 			continue;
885 		}
886 
887 		if (udpv6_queue_rcv_skb(sk, nskb) > 0)
888 			consume_skb(nskb);
889 	}
890 
891 	/* Also lookup *:port if we are using hash2 and haven't done so yet. */
892 	if (use_hash2 && hash2 != hash2_any) {
893 		hash2 = hash2_any;
894 		goto start_lookup;
895 	}
896 
897 	if (first) {
898 		if (udpv6_queue_rcv_skb(first, skb) > 0)
899 			consume_skb(skb);
900 	} else {
901 		kfree_skb(skb);
902 		__UDP6_INC_STATS(net, UDP_MIB_IGNOREDMULTI,
903 				 proto == IPPROTO_UDPLITE);
904 	}
905 	return 0;
906 }
907 
udp6_sk_rx_dst_set(struct sock * sk,struct dst_entry * dst)908 static void udp6_sk_rx_dst_set(struct sock *sk, struct dst_entry *dst)
909 {
910 	if (udp_sk_rx_dst_set(sk, dst)) {
911 		const struct rt6_info *rt = (const struct rt6_info *)dst;
912 
913 		sk->sk_rx_dst_cookie = rt6_get_cookie(rt);
914 	}
915 }
916 
917 /* wrapper for udp_queue_rcv_skb tacking care of csum conversion and
918  * return code conversion for ip layer consumption
919  */
udp6_unicast_rcv_skb(struct sock * sk,struct sk_buff * skb,struct udphdr * uh)920 static int udp6_unicast_rcv_skb(struct sock *sk, struct sk_buff *skb,
921 				struct udphdr *uh)
922 {
923 	int ret;
924 
925 	if (inet_get_convert_csum(sk) && uh->check && !IS_UDPLITE(sk))
926 		skb_checksum_try_convert(skb, IPPROTO_UDP, ip6_compute_pseudo);
927 
928 	ret = udpv6_queue_rcv_skb(sk, skb);
929 
930 	/* a return value > 0 means to resubmit the input */
931 	if (ret > 0)
932 		return ret;
933 	return 0;
934 }
935 
__udp6_lib_rcv(struct sk_buff * skb,struct udp_table * udptable,int proto)936 int __udp6_lib_rcv(struct sk_buff *skb, struct udp_table *udptable,
937 		   int proto)
938 {
939 	enum skb_drop_reason reason = SKB_DROP_REASON_NOT_SPECIFIED;
940 	const struct in6_addr *saddr, *daddr;
941 	struct net *net = dev_net(skb->dev);
942 	struct udphdr *uh;
943 	struct sock *sk;
944 	bool refcounted;
945 	u32 ulen = 0;
946 
947 	if (!pskb_may_pull(skb, sizeof(struct udphdr)))
948 		goto discard;
949 
950 	saddr = &ipv6_hdr(skb)->saddr;
951 	daddr = &ipv6_hdr(skb)->daddr;
952 	uh = udp_hdr(skb);
953 
954 	ulen = ntohs(uh->len);
955 	if (ulen > skb->len)
956 		goto short_packet;
957 
958 	if (proto == IPPROTO_UDP) {
959 		/* UDP validates ulen. */
960 
961 		/* Check for jumbo payload */
962 		if (ulen == 0)
963 			ulen = skb->len;
964 
965 		if (ulen < sizeof(*uh))
966 			goto short_packet;
967 
968 		if (ulen < skb->len) {
969 			if (pskb_trim_rcsum(skb, ulen))
970 				goto short_packet;
971 			saddr = &ipv6_hdr(skb)->saddr;
972 			daddr = &ipv6_hdr(skb)->daddr;
973 			uh = udp_hdr(skb);
974 		}
975 	}
976 
977 	if (udp6_csum_init(skb, uh, proto))
978 		goto csum_error;
979 
980 	/* Check if the socket is already available, e.g. due to early demux */
981 	sk = skb_steal_sock(skb, &refcounted);
982 	if (sk) {
983 		struct dst_entry *dst = skb_dst(skb);
984 		int ret;
985 
986 		if (unlikely(rcu_dereference(sk->sk_rx_dst) != dst))
987 			udp6_sk_rx_dst_set(sk, dst);
988 
989 		if (!uh->check && !udp_sk(sk)->no_check6_rx) {
990 			if (refcounted)
991 				sock_put(sk);
992 			goto report_csum_error;
993 		}
994 
995 		ret = udp6_unicast_rcv_skb(sk, skb, uh);
996 		if (refcounted)
997 			sock_put(sk);
998 		return ret;
999 	}
1000 
1001 	/*
1002 	 *	Multicast receive code
1003 	 */
1004 	if (ipv6_addr_is_multicast(daddr))
1005 		return __udp6_lib_mcast_deliver(net, skb,
1006 				saddr, daddr, udptable, proto);
1007 
1008 	/* Unicast */
1009 	sk = __udp6_lib_lookup_skb(skb, uh->source, uh->dest, udptable);
1010 	if (sk) {
1011 		if (!uh->check && !udp_sk(sk)->no_check6_rx)
1012 			goto report_csum_error;
1013 		return udp6_unicast_rcv_skb(sk, skb, uh);
1014 	}
1015 
1016 	reason = SKB_DROP_REASON_NO_SOCKET;
1017 
1018 	if (!uh->check)
1019 		goto report_csum_error;
1020 
1021 	if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
1022 		goto discard;
1023 
1024 	if (udp_lib_checksum_complete(skb))
1025 		goto csum_error;
1026 
1027 	__UDP6_INC_STATS(net, UDP_MIB_NOPORTS, proto == IPPROTO_UDPLITE);
1028 	icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0);
1029 
1030 	kfree_skb_reason(skb, reason);
1031 	return 0;
1032 
1033 short_packet:
1034 	if (reason == SKB_DROP_REASON_NOT_SPECIFIED)
1035 		reason = SKB_DROP_REASON_PKT_TOO_SMALL;
1036 	net_dbg_ratelimited("UDP%sv6: short packet: From [%pI6c]:%u %d/%d to [%pI6c]:%u\n",
1037 			    proto == IPPROTO_UDPLITE ? "-Lite" : "",
1038 			    saddr, ntohs(uh->source),
1039 			    ulen, skb->len,
1040 			    daddr, ntohs(uh->dest));
1041 	goto discard;
1042 
1043 report_csum_error:
1044 	udp6_csum_zero_error(skb);
1045 csum_error:
1046 	if (reason == SKB_DROP_REASON_NOT_SPECIFIED)
1047 		reason = SKB_DROP_REASON_UDP_CSUM;
1048 	__UDP6_INC_STATS(net, UDP_MIB_CSUMERRORS, proto == IPPROTO_UDPLITE);
1049 discard:
1050 	__UDP6_INC_STATS(net, UDP_MIB_INERRORS, proto == IPPROTO_UDPLITE);
1051 	kfree_skb_reason(skb, reason);
1052 	return 0;
1053 }
1054 
1055 
__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)1056 static struct sock *__udp6_lib_demux_lookup(struct net *net,
1057 			__be16 loc_port, const struct in6_addr *loc_addr,
1058 			__be16 rmt_port, const struct in6_addr *rmt_addr,
1059 			int dif, int sdif)
1060 {
1061 	unsigned short hnum = ntohs(loc_port);
1062 	unsigned int hash2 = ipv6_portaddr_hash(net, loc_addr, hnum);
1063 	unsigned int slot2 = hash2 & udp_table.mask;
1064 	struct udp_hslot *hslot2 = &udp_table.hash2[slot2];
1065 	const __portpair ports = INET_COMBINED_PORTS(rmt_port, hnum);
1066 	struct sock *sk;
1067 
1068 	udp_portaddr_for_each_entry_rcu(sk, &hslot2->head) {
1069 		if (sk->sk_state == TCP_ESTABLISHED &&
1070 		    inet6_match(net, sk, rmt_addr, loc_addr, ports, dif, sdif))
1071 			return sk;
1072 		/* Only check first socket in chain */
1073 		break;
1074 	}
1075 	return NULL;
1076 }
1077 
udp_v6_early_demux(struct sk_buff * skb)1078 void udp_v6_early_demux(struct sk_buff *skb)
1079 {
1080 	struct net *net = dev_net(skb->dev);
1081 	const struct udphdr *uh;
1082 	struct sock *sk;
1083 	struct dst_entry *dst;
1084 	int dif = skb->dev->ifindex;
1085 	int sdif = inet6_sdif(skb);
1086 
1087 	if (!pskb_may_pull(skb, skb_transport_offset(skb) +
1088 	    sizeof(struct udphdr)))
1089 		return;
1090 
1091 	uh = udp_hdr(skb);
1092 
1093 	if (skb->pkt_type == PACKET_HOST)
1094 		sk = __udp6_lib_demux_lookup(net, uh->dest,
1095 					     &ipv6_hdr(skb)->daddr,
1096 					     uh->source, &ipv6_hdr(skb)->saddr,
1097 					     dif, sdif);
1098 	else
1099 		return;
1100 
1101 	if (!sk || !refcount_inc_not_zero(&sk->sk_refcnt))
1102 		return;
1103 
1104 	skb->sk = sk;
1105 	skb->destructor = sock_efree;
1106 	dst = rcu_dereference(sk->sk_rx_dst);
1107 
1108 	if (dst)
1109 		dst = dst_check(dst, sk->sk_rx_dst_cookie);
1110 	if (dst) {
1111 		/* set noref for now.
1112 		 * any place which wants to hold dst has to call
1113 		 * dst_hold_safe()
1114 		 */
1115 		skb_dst_set_noref(skb, dst);
1116 	}
1117 }
1118 
udpv6_rcv(struct sk_buff * skb)1119 INDIRECT_CALLABLE_SCOPE int udpv6_rcv(struct sk_buff *skb)
1120 {
1121 	return __udp6_lib_rcv(skb, &udp_table, IPPROTO_UDP);
1122 }
1123 
1124 /*
1125  * Throw away all pending data and cancel the corking. Socket is locked.
1126  */
udp_v6_flush_pending_frames(struct sock * sk)1127 static void udp_v6_flush_pending_frames(struct sock *sk)
1128 {
1129 	struct udp_sock *up = udp_sk(sk);
1130 
1131 	if (up->pending == AF_INET)
1132 		udp_flush_pending_frames(sk);
1133 	else if (up->pending) {
1134 		up->len = 0;
1135 		up->pending = 0;
1136 		ip6_flush_pending_frames(sk);
1137 	}
1138 }
1139 
udpv6_pre_connect(struct sock * sk,struct sockaddr * uaddr,int addr_len)1140 static int udpv6_pre_connect(struct sock *sk, struct sockaddr *uaddr,
1141 			     int addr_len)
1142 {
1143 	if (addr_len < offsetofend(struct sockaddr, sa_family))
1144 		return -EINVAL;
1145 	/* The following checks are replicated from __ip6_datagram_connect()
1146 	 * and intended to prevent BPF program called below from accessing
1147 	 * bytes that are out of the bound specified by user in addr_len.
1148 	 */
1149 	if (uaddr->sa_family == AF_INET) {
1150 		if (__ipv6_only_sock(sk))
1151 			return -EAFNOSUPPORT;
1152 		return udp_pre_connect(sk, uaddr, addr_len);
1153 	}
1154 
1155 	if (addr_len < SIN6_LEN_RFC2133)
1156 		return -EINVAL;
1157 
1158 	return BPF_CGROUP_RUN_PROG_INET6_CONNECT_LOCK(sk, uaddr);
1159 }
1160 
1161 /**
1162  *	udp6_hwcsum_outgoing  -  handle outgoing HW checksumming
1163  *	@sk:	socket we are sending on
1164  *	@skb:	sk_buff containing the filled-in UDP header
1165  *		(checksum field must be zeroed out)
1166  *	@saddr: source address
1167  *	@daddr: destination address
1168  *	@len:	length of packet
1169  */
udp6_hwcsum_outgoing(struct sock * sk,struct sk_buff * skb,const struct in6_addr * saddr,const struct in6_addr * daddr,int len)1170 static void udp6_hwcsum_outgoing(struct sock *sk, struct sk_buff *skb,
1171 				 const struct in6_addr *saddr,
1172 				 const struct in6_addr *daddr, int len)
1173 {
1174 	unsigned int offset;
1175 	struct udphdr *uh = udp_hdr(skb);
1176 	struct sk_buff *frags = skb_shinfo(skb)->frag_list;
1177 	__wsum csum = 0;
1178 
1179 	if (!frags) {
1180 		/* Only one fragment on the socket.  */
1181 		skb->csum_start = skb_transport_header(skb) - skb->head;
1182 		skb->csum_offset = offsetof(struct udphdr, check);
1183 		uh->check = ~csum_ipv6_magic(saddr, daddr, len, IPPROTO_UDP, 0);
1184 	} else {
1185 		/*
1186 		 * HW-checksum won't work as there are two or more
1187 		 * fragments on the socket so that all csums of sk_buffs
1188 		 * should be together
1189 		 */
1190 		offset = skb_transport_offset(skb);
1191 		skb->csum = skb_checksum(skb, offset, skb->len - offset, 0);
1192 		csum = skb->csum;
1193 
1194 		skb->ip_summed = CHECKSUM_NONE;
1195 
1196 		do {
1197 			csum = csum_add(csum, frags->csum);
1198 		} while ((frags = frags->next));
1199 
1200 		uh->check = csum_ipv6_magic(saddr, daddr, len, IPPROTO_UDP,
1201 					    csum);
1202 		if (uh->check == 0)
1203 			uh->check = CSUM_MANGLED_0;
1204 	}
1205 }
1206 
1207 /*
1208  *	Sending
1209  */
1210 
udp_v6_send_skb(struct sk_buff * skb,struct flowi6 * fl6,struct inet_cork * cork)1211 static int udp_v6_send_skb(struct sk_buff *skb, struct flowi6 *fl6,
1212 			   struct inet_cork *cork)
1213 {
1214 	struct sock *sk = skb->sk;
1215 	struct udphdr *uh;
1216 	int err = 0;
1217 	int is_udplite = IS_UDPLITE(sk);
1218 	__wsum csum = 0;
1219 	int offset = skb_transport_offset(skb);
1220 	int len = skb->len - offset;
1221 	int datalen = len - sizeof(*uh);
1222 
1223 	/*
1224 	 * Create a UDP header
1225 	 */
1226 	uh = udp_hdr(skb);
1227 	uh->source = fl6->fl6_sport;
1228 	uh->dest = fl6->fl6_dport;
1229 	uh->len = htons(len);
1230 	uh->check = 0;
1231 
1232 	if (cork->gso_size) {
1233 		const int hlen = skb_network_header_len(skb) +
1234 				 sizeof(struct udphdr);
1235 
1236 		if (hlen + cork->gso_size > cork->fragsize) {
1237 			kfree_skb(skb);
1238 			return -EINVAL;
1239 		}
1240 		if (datalen > cork->gso_size * UDP_MAX_SEGMENTS) {
1241 			kfree_skb(skb);
1242 			return -EINVAL;
1243 		}
1244 		if (udp_sk(sk)->no_check6_tx) {
1245 			kfree_skb(skb);
1246 			return -EINVAL;
1247 		}
1248 		if (skb->ip_summed != CHECKSUM_PARTIAL || is_udplite ||
1249 		    dst_xfrm(skb_dst(skb))) {
1250 			kfree_skb(skb);
1251 			return -EIO;
1252 		}
1253 
1254 		if (datalen > cork->gso_size) {
1255 			skb_shinfo(skb)->gso_size = cork->gso_size;
1256 			skb_shinfo(skb)->gso_type = SKB_GSO_UDP_L4;
1257 			skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(datalen,
1258 								 cork->gso_size);
1259 		}
1260 		goto csum_partial;
1261 	}
1262 
1263 	if (is_udplite)
1264 		csum = udplite_csum(skb);
1265 	else if (udp_sk(sk)->no_check6_tx) {   /* UDP csum disabled */
1266 		skb->ip_summed = CHECKSUM_NONE;
1267 		goto send;
1268 	} else if (skb->ip_summed == CHECKSUM_PARTIAL) { /* UDP hardware csum */
1269 csum_partial:
1270 		udp6_hwcsum_outgoing(sk, skb, &fl6->saddr, &fl6->daddr, len);
1271 		goto send;
1272 	} else
1273 		csum = udp_csum(skb);
1274 
1275 	/* add protocol-dependent pseudo-header */
1276 	uh->check = csum_ipv6_magic(&fl6->saddr, &fl6->daddr,
1277 				    len, fl6->flowi6_proto, csum);
1278 	if (uh->check == 0)
1279 		uh->check = CSUM_MANGLED_0;
1280 
1281 send:
1282 	err = ip6_send_skb(skb);
1283 	if (err) {
1284 		if (err == -ENOBUFS && !inet6_sk(sk)->recverr) {
1285 			UDP6_INC_STATS(sock_net(sk),
1286 				       UDP_MIB_SNDBUFERRORS, is_udplite);
1287 			err = 0;
1288 		}
1289 	} else {
1290 		UDP6_INC_STATS(sock_net(sk),
1291 			       UDP_MIB_OUTDATAGRAMS, is_udplite);
1292 	}
1293 	return err;
1294 }
1295 
udp_v6_push_pending_frames(struct sock * sk)1296 static int udp_v6_push_pending_frames(struct sock *sk)
1297 {
1298 	struct sk_buff *skb;
1299 	struct udp_sock  *up = udp_sk(sk);
1300 	struct flowi6 fl6;
1301 	int err = 0;
1302 
1303 	if (up->pending == AF_INET)
1304 		return udp_push_pending_frames(sk);
1305 
1306 	/* ip6_finish_skb will release the cork, so make a copy of
1307 	 * fl6 here.
1308 	 */
1309 	fl6 = inet_sk(sk)->cork.fl.u.ip6;
1310 
1311 	skb = ip6_finish_skb(sk);
1312 	if (!skb)
1313 		goto out;
1314 
1315 	err = udp_v6_send_skb(skb, &fl6, &inet_sk(sk)->cork.base);
1316 
1317 out:
1318 	up->len = 0;
1319 	up->pending = 0;
1320 	return err;
1321 }
1322 
udpv6_sendmsg(struct sock * sk,struct msghdr * msg,size_t len)1323 int udpv6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
1324 {
1325 	struct ipv6_txoptions opt_space;
1326 	struct udp_sock *up = udp_sk(sk);
1327 	struct inet_sock *inet = inet_sk(sk);
1328 	struct ipv6_pinfo *np = inet6_sk(sk);
1329 	DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name);
1330 	struct in6_addr *daddr, *final_p, final;
1331 	struct ipv6_txoptions *opt = NULL;
1332 	struct ipv6_txoptions *opt_to_free = NULL;
1333 	struct ip6_flowlabel *flowlabel = NULL;
1334 	struct flowi6 fl6;
1335 	struct dst_entry *dst;
1336 	struct ipcm6_cookie ipc6;
1337 	int addr_len = msg->msg_namelen;
1338 	bool connected = false;
1339 	int ulen = len;
1340 	int corkreq = READ_ONCE(up->corkflag) || msg->msg_flags&MSG_MORE;
1341 	int err;
1342 	int is_udplite = IS_UDPLITE(sk);
1343 	int (*getfrag)(void *, char *, int, int, int, struct sk_buff *);
1344 
1345 	ipcm6_init(&ipc6);
1346 	ipc6.gso_size = READ_ONCE(up->gso_size);
1347 	ipc6.sockc.tsflags = sk->sk_tsflags;
1348 	ipc6.sockc.mark = sk->sk_mark;
1349 
1350 	/* destination address check */
1351 	if (sin6) {
1352 		if (addr_len < offsetof(struct sockaddr, sa_data))
1353 			return -EINVAL;
1354 
1355 		switch (sin6->sin6_family) {
1356 		case AF_INET6:
1357 			if (addr_len < SIN6_LEN_RFC2133)
1358 				return -EINVAL;
1359 			daddr = &sin6->sin6_addr;
1360 			if (ipv6_addr_any(daddr) &&
1361 			    ipv6_addr_v4mapped(&np->saddr))
1362 				ipv6_addr_set_v4mapped(htonl(INADDR_LOOPBACK),
1363 						       daddr);
1364 			break;
1365 		case AF_INET:
1366 			goto do_udp_sendmsg;
1367 		case AF_UNSPEC:
1368 			msg->msg_name = sin6 = NULL;
1369 			msg->msg_namelen = addr_len = 0;
1370 			daddr = NULL;
1371 			break;
1372 		default:
1373 			return -EINVAL;
1374 		}
1375 	} else if (!up->pending) {
1376 		if (sk->sk_state != TCP_ESTABLISHED)
1377 			return -EDESTADDRREQ;
1378 		daddr = &sk->sk_v6_daddr;
1379 	} else
1380 		daddr = NULL;
1381 
1382 	if (daddr) {
1383 		if (ipv6_addr_v4mapped(daddr)) {
1384 			struct sockaddr_in sin;
1385 			sin.sin_family = AF_INET;
1386 			sin.sin_port = sin6 ? sin6->sin6_port : inet->inet_dport;
1387 			sin.sin_addr.s_addr = daddr->s6_addr32[3];
1388 			msg->msg_name = &sin;
1389 			msg->msg_namelen = sizeof(sin);
1390 do_udp_sendmsg:
1391 			err = __ipv6_only_sock(sk) ?
1392 				-ENETUNREACH : udp_sendmsg(sk, msg, len);
1393 			msg->msg_name = sin6;
1394 			msg->msg_namelen = addr_len;
1395 			return err;
1396 		}
1397 	}
1398 
1399 	if (up->pending == AF_INET)
1400 		return udp_sendmsg(sk, msg, len);
1401 
1402 	/* Rough check on arithmetic overflow,
1403 	   better check is made in ip6_append_data().
1404 	   */
1405 	if (len > INT_MAX - sizeof(struct udphdr))
1406 		return -EMSGSIZE;
1407 
1408 	getfrag  =  is_udplite ?  udplite_getfrag : ip_generic_getfrag;
1409 	if (up->pending) {
1410 		/*
1411 		 * There are pending frames.
1412 		 * The socket lock must be held while it's corked.
1413 		 */
1414 		lock_sock(sk);
1415 		if (likely(up->pending)) {
1416 			if (unlikely(up->pending != AF_INET6)) {
1417 				release_sock(sk);
1418 				return -EAFNOSUPPORT;
1419 			}
1420 			dst = NULL;
1421 			goto do_append_data;
1422 		}
1423 		release_sock(sk);
1424 	}
1425 	ulen += sizeof(struct udphdr);
1426 
1427 	memset(&fl6, 0, sizeof(fl6));
1428 
1429 	if (sin6) {
1430 		if (sin6->sin6_port == 0)
1431 			return -EINVAL;
1432 
1433 		fl6.fl6_dport = sin6->sin6_port;
1434 		daddr = &sin6->sin6_addr;
1435 
1436 		if (np->sndflow) {
1437 			fl6.flowlabel = sin6->sin6_flowinfo&IPV6_FLOWINFO_MASK;
1438 			if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) {
1439 				flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
1440 				if (IS_ERR(flowlabel))
1441 					return -EINVAL;
1442 			}
1443 		}
1444 
1445 		/*
1446 		 * Otherwise it will be difficult to maintain
1447 		 * sk->sk_dst_cache.
1448 		 */
1449 		if (sk->sk_state == TCP_ESTABLISHED &&
1450 		    ipv6_addr_equal(daddr, &sk->sk_v6_daddr))
1451 			daddr = &sk->sk_v6_daddr;
1452 
1453 		if (addr_len >= sizeof(struct sockaddr_in6) &&
1454 		    sin6->sin6_scope_id &&
1455 		    __ipv6_addr_needs_scope_id(__ipv6_addr_type(daddr)))
1456 			fl6.flowi6_oif = sin6->sin6_scope_id;
1457 	} else {
1458 		if (sk->sk_state != TCP_ESTABLISHED)
1459 			return -EDESTADDRREQ;
1460 
1461 		fl6.fl6_dport = inet->inet_dport;
1462 		daddr = &sk->sk_v6_daddr;
1463 		fl6.flowlabel = np->flow_label;
1464 		connected = true;
1465 	}
1466 
1467 	if (!fl6.flowi6_oif)
1468 		fl6.flowi6_oif = sk->sk_bound_dev_if;
1469 
1470 	if (!fl6.flowi6_oif)
1471 		fl6.flowi6_oif = np->sticky_pktinfo.ipi6_ifindex;
1472 
1473 	fl6.flowi6_uid = sk->sk_uid;
1474 
1475 	if (msg->msg_controllen) {
1476 		opt = &opt_space;
1477 		memset(opt, 0, sizeof(struct ipv6_txoptions));
1478 		opt->tot_len = sizeof(*opt);
1479 		ipc6.opt = opt;
1480 
1481 		err = udp_cmsg_send(sk, msg, &ipc6.gso_size);
1482 		if (err > 0)
1483 			err = ip6_datagram_send_ctl(sock_net(sk), sk, msg, &fl6,
1484 						    &ipc6);
1485 		if (err < 0) {
1486 			fl6_sock_release(flowlabel);
1487 			return err;
1488 		}
1489 		if ((fl6.flowlabel&IPV6_FLOWLABEL_MASK) && !flowlabel) {
1490 			flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
1491 			if (IS_ERR(flowlabel))
1492 				return -EINVAL;
1493 		}
1494 		if (!(opt->opt_nflen|opt->opt_flen))
1495 			opt = NULL;
1496 		connected = false;
1497 	}
1498 	if (!opt) {
1499 		opt = txopt_get(np);
1500 		opt_to_free = opt;
1501 	}
1502 	if (flowlabel)
1503 		opt = fl6_merge_options(&opt_space, flowlabel, opt);
1504 	opt = ipv6_fixup_options(&opt_space, opt);
1505 	ipc6.opt = opt;
1506 
1507 	fl6.flowi6_proto = sk->sk_protocol;
1508 	fl6.flowi6_mark = ipc6.sockc.mark;
1509 	fl6.daddr = *daddr;
1510 	if (ipv6_addr_any(&fl6.saddr) && !ipv6_addr_any(&np->saddr))
1511 		fl6.saddr = np->saddr;
1512 	fl6.fl6_sport = inet->inet_sport;
1513 
1514 	if (cgroup_bpf_enabled(CGROUP_UDP6_SENDMSG) && !connected) {
1515 		err = BPF_CGROUP_RUN_PROG_UDP6_SENDMSG_LOCK(sk,
1516 					   (struct sockaddr *)sin6, &fl6.saddr);
1517 		if (err)
1518 			goto out_no_dst;
1519 		if (sin6) {
1520 			if (ipv6_addr_v4mapped(&sin6->sin6_addr)) {
1521 				/* BPF program rewrote IPv6-only by IPv4-mapped
1522 				 * IPv6. It's currently unsupported.
1523 				 */
1524 				err = -ENOTSUPP;
1525 				goto out_no_dst;
1526 			}
1527 			if (sin6->sin6_port == 0) {
1528 				/* BPF program set invalid port. Reject it. */
1529 				err = -EINVAL;
1530 				goto out_no_dst;
1531 			}
1532 			fl6.fl6_dport = sin6->sin6_port;
1533 			fl6.daddr = sin6->sin6_addr;
1534 		}
1535 	}
1536 
1537 	if (ipv6_addr_any(&fl6.daddr))
1538 		fl6.daddr.s6_addr[15] = 0x1; /* :: means loopback (BSD'ism) */
1539 
1540 	final_p = fl6_update_dst(&fl6, opt, &final);
1541 	if (final_p)
1542 		connected = false;
1543 
1544 	if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr)) {
1545 		fl6.flowi6_oif = np->mcast_oif;
1546 		connected = false;
1547 	} else if (!fl6.flowi6_oif)
1548 		fl6.flowi6_oif = np->ucast_oif;
1549 
1550 	security_sk_classify_flow(sk, flowi6_to_flowi_common(&fl6));
1551 
1552 	if (ipc6.tclass < 0)
1553 		ipc6.tclass = np->tclass;
1554 
1555 	fl6.flowlabel = ip6_make_flowinfo(ipc6.tclass, fl6.flowlabel);
1556 
1557 	dst = ip6_sk_dst_lookup_flow(sk, &fl6, final_p, connected);
1558 	if (IS_ERR(dst)) {
1559 		err = PTR_ERR(dst);
1560 		dst = NULL;
1561 		goto out;
1562 	}
1563 
1564 	if (ipc6.hlimit < 0)
1565 		ipc6.hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst);
1566 
1567 	if (msg->msg_flags&MSG_CONFIRM)
1568 		goto do_confirm;
1569 back_from_confirm:
1570 
1571 	/* Lockless fast path for the non-corking case */
1572 	if (!corkreq) {
1573 		struct inet_cork_full cork;
1574 		struct sk_buff *skb;
1575 
1576 		skb = ip6_make_skb(sk, getfrag, msg, ulen,
1577 				   sizeof(struct udphdr), &ipc6,
1578 				   &fl6, (struct rt6_info *)dst,
1579 				   msg->msg_flags, &cork);
1580 		err = PTR_ERR(skb);
1581 		if (!IS_ERR_OR_NULL(skb))
1582 			err = udp_v6_send_skb(skb, &fl6, &cork.base);
1583 		goto out;
1584 	}
1585 
1586 	lock_sock(sk);
1587 	if (unlikely(up->pending)) {
1588 		/* The socket is already corked while preparing it. */
1589 		/* ... which is an evident application bug. --ANK */
1590 		release_sock(sk);
1591 
1592 		net_dbg_ratelimited("udp cork app bug 2\n");
1593 		err = -EINVAL;
1594 		goto out;
1595 	}
1596 
1597 	up->pending = AF_INET6;
1598 
1599 do_append_data:
1600 	if (ipc6.dontfrag < 0)
1601 		ipc6.dontfrag = np->dontfrag;
1602 	up->len += ulen;
1603 	err = ip6_append_data(sk, getfrag, msg, ulen, sizeof(struct udphdr),
1604 			      &ipc6, &fl6, (struct rt6_info *)dst,
1605 			      corkreq ? msg->msg_flags|MSG_MORE : msg->msg_flags);
1606 	if (err)
1607 		udp_v6_flush_pending_frames(sk);
1608 	else if (!corkreq)
1609 		err = udp_v6_push_pending_frames(sk);
1610 	else if (unlikely(skb_queue_empty(&sk->sk_write_queue)))
1611 		up->pending = 0;
1612 
1613 	if (err > 0)
1614 		err = np->recverr ? net_xmit_errno(err) : 0;
1615 	release_sock(sk);
1616 
1617 out:
1618 	dst_release(dst);
1619 out_no_dst:
1620 	fl6_sock_release(flowlabel);
1621 	txopt_put(opt_to_free);
1622 	if (!err)
1623 		return len;
1624 	/*
1625 	 * ENOBUFS = no kernel mem, SOCK_NOSPACE = no sndbuf space.  Reporting
1626 	 * ENOBUFS might not be good (it's not tunable per se), but otherwise
1627 	 * we don't have a good statistic (IpOutDiscards but it can be too many
1628 	 * things).  We could add another new stat but at least for now that
1629 	 * seems like overkill.
1630 	 */
1631 	if (err == -ENOBUFS || test_bit(SOCK_NOSPACE, &sk->sk_socket->flags)) {
1632 		UDP6_INC_STATS(sock_net(sk),
1633 			       UDP_MIB_SNDBUFERRORS, is_udplite);
1634 	}
1635 	return err;
1636 
1637 do_confirm:
1638 	if (msg->msg_flags & MSG_PROBE)
1639 		dst_confirm_neigh(dst, &fl6.daddr);
1640 	if (!(msg->msg_flags&MSG_PROBE) || len)
1641 		goto back_from_confirm;
1642 	err = 0;
1643 	goto out;
1644 }
1645 
udpv6_destroy_sock(struct sock * sk)1646 void udpv6_destroy_sock(struct sock *sk)
1647 {
1648 	struct udp_sock *up = udp_sk(sk);
1649 	lock_sock(sk);
1650 
1651 	/* protects from races with udp_abort() */
1652 	sock_set_flag(sk, SOCK_DEAD);
1653 	udp_v6_flush_pending_frames(sk);
1654 	release_sock(sk);
1655 
1656 	if (static_branch_unlikely(&udpv6_encap_needed_key)) {
1657 		if (up->encap_type) {
1658 			void (*encap_destroy)(struct sock *sk);
1659 			encap_destroy = READ_ONCE(up->encap_destroy);
1660 			if (encap_destroy)
1661 				encap_destroy(sk);
1662 		}
1663 		if (up->encap_enabled) {
1664 			static_branch_dec(&udpv6_encap_needed_key);
1665 			udp_encap_disable();
1666 		}
1667 	}
1668 }
1669 
1670 /*
1671  *	Socket option code for UDP
1672  */
udpv6_setsockopt(struct sock * sk,int level,int optname,sockptr_t optval,unsigned int optlen)1673 int udpv6_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval,
1674 		     unsigned int optlen)
1675 {
1676 	if (level == SOL_UDP  ||  level == SOL_UDPLITE)
1677 		return udp_lib_setsockopt(sk, level, optname,
1678 					  optval, optlen,
1679 					  udp_v6_push_pending_frames);
1680 	return ipv6_setsockopt(sk, level, optname, optval, optlen);
1681 }
1682 
udpv6_getsockopt(struct sock * sk,int level,int optname,char __user * optval,int __user * optlen)1683 int udpv6_getsockopt(struct sock *sk, int level, int optname,
1684 		     char __user *optval, int __user *optlen)
1685 {
1686 	if (level == SOL_UDP  ||  level == SOL_UDPLITE)
1687 		return udp_lib_getsockopt(sk, level, optname, optval, optlen);
1688 	return ipv6_getsockopt(sk, level, optname, optval, optlen);
1689 }
1690 
1691 static const struct inet6_protocol udpv6_protocol = {
1692 	.handler	=	udpv6_rcv,
1693 	.err_handler	=	udpv6_err,
1694 	.flags		=	INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
1695 };
1696 
1697 /* ------------------------------------------------------------------------ */
1698 #ifdef CONFIG_PROC_FS
udp6_seq_show(struct seq_file * seq,void * v)1699 int udp6_seq_show(struct seq_file *seq, void *v)
1700 {
1701 	if (v == SEQ_START_TOKEN) {
1702 		seq_puts(seq, IPV6_SEQ_DGRAM_HEADER);
1703 	} else {
1704 		int bucket = ((struct udp_iter_state *)seq->private)->bucket;
1705 		struct inet_sock *inet = inet_sk(v);
1706 		__u16 srcp = ntohs(inet->inet_sport);
1707 		__u16 destp = ntohs(inet->inet_dport);
1708 		__ip6_dgram_sock_seq_show(seq, v, srcp, destp,
1709 					  udp_rqueue_get(v), bucket);
1710 	}
1711 	return 0;
1712 }
1713 
1714 const struct seq_operations udp6_seq_ops = {
1715 	.start		= udp_seq_start,
1716 	.next		= udp_seq_next,
1717 	.stop		= udp_seq_stop,
1718 	.show		= udp6_seq_show,
1719 };
1720 EXPORT_SYMBOL(udp6_seq_ops);
1721 
1722 static struct udp_seq_afinfo udp6_seq_afinfo = {
1723 	.family		= AF_INET6,
1724 	.udp_table	= &udp_table,
1725 };
1726 
udp6_proc_init(struct net * net)1727 int __net_init udp6_proc_init(struct net *net)
1728 {
1729 	if (!proc_create_net_data("udp6", 0444, net->proc_net, &udp6_seq_ops,
1730 			sizeof(struct udp_iter_state), &udp6_seq_afinfo))
1731 		return -ENOMEM;
1732 	return 0;
1733 }
1734 
udp6_proc_exit(struct net * net)1735 void udp6_proc_exit(struct net *net)
1736 {
1737 	remove_proc_entry("udp6", net->proc_net);
1738 }
1739 #endif /* CONFIG_PROC_FS */
1740 
1741 /* ------------------------------------------------------------------------ */
1742 
1743 struct proto udpv6_prot = {
1744 	.name			= "UDPv6",
1745 	.owner			= THIS_MODULE,
1746 	.close			= udp_lib_close,
1747 	.pre_connect		= udpv6_pre_connect,
1748 	.connect		= ip6_datagram_connect,
1749 	.disconnect		= udp_disconnect,
1750 	.ioctl			= udp_ioctl,
1751 	.init			= udpv6_init_sock,
1752 	.destroy		= udpv6_destroy_sock,
1753 	.setsockopt		= udpv6_setsockopt,
1754 	.getsockopt		= udpv6_getsockopt,
1755 	.sendmsg		= udpv6_sendmsg,
1756 	.recvmsg		= udpv6_recvmsg,
1757 	.release_cb		= ip6_datagram_release_cb,
1758 	.hash			= udp_lib_hash,
1759 	.unhash			= udp_lib_unhash,
1760 	.rehash			= udp_v6_rehash,
1761 	.get_port		= udp_v6_get_port,
1762 #ifdef CONFIG_BPF_SYSCALL
1763 	.psock_update_sk_prot	= udp_bpf_update_proto,
1764 #endif
1765 	.memory_allocated	= &udp_memory_allocated,
1766 	.sysctl_mem		= sysctl_udp_mem,
1767 	.sysctl_wmem_offset     = offsetof(struct net, ipv4.sysctl_udp_wmem_min),
1768 	.sysctl_rmem_offset     = offsetof(struct net, ipv4.sysctl_udp_rmem_min),
1769 	.obj_size		= sizeof(struct udp6_sock),
1770 	.h.udp_table		= &udp_table,
1771 	.diag_destroy		= udp_abort,
1772 };
1773 
1774 static struct inet_protosw udpv6_protosw = {
1775 	.type =      SOCK_DGRAM,
1776 	.protocol =  IPPROTO_UDP,
1777 	.prot =      &udpv6_prot,
1778 	.ops =       &inet6_dgram_ops,
1779 	.flags =     INET_PROTOSW_PERMANENT,
1780 };
1781 
udpv6_init(void)1782 int __init udpv6_init(void)
1783 {
1784 	int ret;
1785 
1786 	ret = inet6_add_protocol(&udpv6_protocol, IPPROTO_UDP);
1787 	if (ret)
1788 		goto out;
1789 
1790 	ret = inet6_register_protosw(&udpv6_protosw);
1791 	if (ret)
1792 		goto out_udpv6_protocol;
1793 out:
1794 	return ret;
1795 
1796 out_udpv6_protocol:
1797 	inet6_del_protocol(&udpv6_protocol, IPPROTO_UDP);
1798 	goto out;
1799 }
1800 
udpv6_exit(void)1801 void udpv6_exit(void)
1802 {
1803 	inet6_unregister_protosw(&udpv6_protosw);
1804 	inet6_del_protocol(&udpv6_protocol, IPPROTO_UDP);
1805 }
1806