xref: /openbmc/linux/net/ipv6/udp.c (revision af276a5a)
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 /* 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)166 static struct sock *udp6_lib_lookup2(struct net *net,
167 		const struct in6_addr *saddr, __be16 sport,
168 		const struct in6_addr *daddr, unsigned int hnum,
169 		int dif, int sdif, struct udp_hslot *hslot2,
170 		struct sk_buff *skb)
171 {
172 	struct sock *sk, *result;
173 	int score, badness;
174 
175 	result = NULL;
176 	badness = -1;
177 	udp_portaddr_for_each_entry_rcu(sk, &hslot2->head) {
178 		score = compute_score(sk, net, saddr, sport,
179 				      daddr, hnum, dif, sdif);
180 		if (score > badness) {
181 			badness = score;
182 
183 			if (sk->sk_state == TCP_ESTABLISHED) {
184 				result = sk;
185 				continue;
186 			}
187 
188 			result = inet6_lookup_reuseport(net, sk, skb, sizeof(struct udphdr),
189 							saddr, sport, daddr, hnum, udp6_ehashfn);
190 			if (!result) {
191 				result = sk;
192 				continue;
193 			}
194 
195 			/* Fall back to scoring if group has connections */
196 			if (!reuseport_has_conns(sk))
197 				return result;
198 
199 			/* Reuseport logic returned an error, keep original score. */
200 			if (IS_ERR(result))
201 				continue;
202 
203 			badness = compute_score(sk, net, saddr, sport,
204 						daddr, hnum, dif, sdif);
205 		}
206 	}
207 	return result;
208 }
209 
210 /* 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)211 struct sock *__udp6_lib_lookup(struct net *net,
212 			       const struct in6_addr *saddr, __be16 sport,
213 			       const struct in6_addr *daddr, __be16 dport,
214 			       int dif, int sdif, struct udp_table *udptable,
215 			       struct sk_buff *skb)
216 {
217 	unsigned short hnum = ntohs(dport);
218 	unsigned int hash2, slot2;
219 	struct udp_hslot *hslot2;
220 	struct sock *result, *sk;
221 
222 	hash2 = ipv6_portaddr_hash(net, daddr, hnum);
223 	slot2 = hash2 & udptable->mask;
224 	hslot2 = &udptable->hash2[slot2];
225 
226 	/* Lookup connected or non-wildcard sockets */
227 	result = udp6_lib_lookup2(net, saddr, sport,
228 				  daddr, hnum, dif, sdif,
229 				  hslot2, skb);
230 	if (!IS_ERR_OR_NULL(result) && result->sk_state == TCP_ESTABLISHED)
231 		goto done;
232 
233 	/* Lookup redirect from BPF */
234 	if (static_branch_unlikely(&bpf_sk_lookup_enabled) &&
235 	    udptable == net->ipv4.udp_table) {
236 		sk = inet6_lookup_run_sk_lookup(net, IPPROTO_UDP, skb, sizeof(struct udphdr),
237 						saddr, sport, daddr, hnum, dif,
238 						udp6_ehashfn);
239 		if (sk) {
240 			result = sk;
241 			goto done;
242 		}
243 	}
244 
245 	/* Got non-wildcard socket or error on first lookup */
246 	if (result)
247 		goto done;
248 
249 	/* Lookup wildcard sockets */
250 	hash2 = ipv6_portaddr_hash(net, &in6addr_any, hnum);
251 	slot2 = hash2 & udptable->mask;
252 	hslot2 = &udptable->hash2[slot2];
253 
254 	result = udp6_lib_lookup2(net, saddr, sport,
255 				  &in6addr_any, hnum, dif, sdif,
256 				  hslot2, skb);
257 done:
258 	if (IS_ERR(result))
259 		return NULL;
260 	return result;
261 }
262 EXPORT_SYMBOL_GPL(__udp6_lib_lookup);
263 
__udp6_lib_lookup_skb(struct sk_buff * skb,__be16 sport,__be16 dport,struct udp_table * udptable)264 static struct sock *__udp6_lib_lookup_skb(struct sk_buff *skb,
265 					  __be16 sport, __be16 dport,
266 					  struct udp_table *udptable)
267 {
268 	const struct ipv6hdr *iph = ipv6_hdr(skb);
269 
270 	return __udp6_lib_lookup(dev_net(skb->dev), &iph->saddr, sport,
271 				 &iph->daddr, dport, inet6_iif(skb),
272 				 inet6_sdif(skb), udptable, skb);
273 }
274 
udp6_lib_lookup_skb(const struct sk_buff * skb,__be16 sport,__be16 dport)275 struct sock *udp6_lib_lookup_skb(const struct sk_buff *skb,
276 				 __be16 sport, __be16 dport)
277 {
278 	const u16 offset = NAPI_GRO_CB(skb)->network_offsets[skb->encapsulation];
279 	const struct ipv6hdr *iph = (struct ipv6hdr *)(skb->data + offset);
280 	struct net *net = dev_net(skb->dev);
281 	int iif, sdif;
282 
283 	inet6_get_iif_sdif(skb, &iif, &sdif);
284 
285 	return __udp6_lib_lookup(net, &iph->saddr, sport,
286 				 &iph->daddr, dport, iif,
287 				 sdif, net->ipv4.udp_table, NULL);
288 }
289 
290 /* Must be called under rcu_read_lock().
291  * Does increment socket refcount.
292  */
293 #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)294 struct sock *udp6_lib_lookup(struct net *net, const struct in6_addr *saddr, __be16 sport,
295 			     const struct in6_addr *daddr, __be16 dport, int dif)
296 {
297 	struct sock *sk;
298 
299 	sk =  __udp6_lib_lookup(net, saddr, sport, daddr, dport,
300 				dif, 0, net->ipv4.udp_table, NULL);
301 	if (sk && !refcount_inc_not_zero(&sk->sk_refcnt))
302 		sk = NULL;
303 	return sk;
304 }
305 EXPORT_SYMBOL_GPL(udp6_lib_lookup);
306 #endif
307 
308 /* do not use the scratch area len for jumbogram: their length execeeds the
309  * scratch area space; note that the IP6CB flags is still in the first
310  * cacheline, so checking for jumbograms is cheap
311  */
udp6_skb_len(struct sk_buff * skb)312 static int udp6_skb_len(struct sk_buff *skb)
313 {
314 	return unlikely(inet6_is_jumbogram(skb)) ? skb->len : udp_skb_len(skb);
315 }
316 
317 /*
318  *	This should be easy, if there is something there we
319  *	return it, otherwise we block.
320  */
321 
udpv6_recvmsg(struct sock * sk,struct msghdr * msg,size_t len,int flags,int * addr_len)322 int udpv6_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
323 		  int flags, int *addr_len)
324 {
325 	struct ipv6_pinfo *np = inet6_sk(sk);
326 	struct inet_sock *inet = inet_sk(sk);
327 	struct sk_buff *skb;
328 	unsigned int ulen, copied;
329 	int off, err, peeking = flags & MSG_PEEK;
330 	int is_udplite = IS_UDPLITE(sk);
331 	struct udp_mib __percpu *mib;
332 	bool checksum_valid = false;
333 	int is_udp4;
334 
335 	if (flags & MSG_ERRQUEUE)
336 		return ipv6_recv_error(sk, msg, len, addr_len);
337 
338 	if (np->rxpmtu && np->rxopt.bits.rxpmtu)
339 		return ipv6_recv_rxpmtu(sk, msg, len, addr_len);
340 
341 try_again:
342 	off = sk_peek_offset(sk, flags);
343 	skb = __skb_recv_udp(sk, flags, &off, &err);
344 	if (!skb)
345 		return err;
346 
347 	ulen = udp6_skb_len(skb);
348 	copied = len;
349 	if (copied > ulen - off)
350 		copied = ulen - off;
351 	else if (copied < ulen)
352 		msg->msg_flags |= MSG_TRUNC;
353 
354 	is_udp4 = (skb->protocol == htons(ETH_P_IP));
355 	mib = __UDPX_MIB(sk, is_udp4);
356 
357 	/*
358 	 * If checksum is needed at all, try to do it while copying the
359 	 * data.  If the data is truncated, or if we only want a partial
360 	 * coverage checksum (UDP-Lite), do it before the copy.
361 	 */
362 
363 	if (copied < ulen || peeking ||
364 	    (is_udplite && UDP_SKB_CB(skb)->partial_cov)) {
365 		checksum_valid = udp_skb_csum_unnecessary(skb) ||
366 				!__udp_lib_checksum_complete(skb);
367 		if (!checksum_valid)
368 			goto csum_copy_err;
369 	}
370 
371 	if (checksum_valid || udp_skb_csum_unnecessary(skb)) {
372 		if (udp_skb_is_linear(skb))
373 			err = copy_linear_skb(skb, copied, off, &msg->msg_iter);
374 		else
375 			err = skb_copy_datagram_msg(skb, off, msg, copied);
376 	} else {
377 		err = skb_copy_and_csum_datagram_msg(skb, off, msg);
378 		if (err == -EINVAL)
379 			goto csum_copy_err;
380 	}
381 	if (unlikely(err)) {
382 		if (!peeking) {
383 			atomic_inc(&sk->sk_drops);
384 			SNMP_INC_STATS(mib, UDP_MIB_INERRORS);
385 		}
386 		kfree_skb(skb);
387 		return err;
388 	}
389 	if (!peeking)
390 		SNMP_INC_STATS(mib, UDP_MIB_INDATAGRAMS);
391 
392 	sock_recv_cmsgs(msg, sk, skb);
393 
394 	/* Copy the address. */
395 	if (msg->msg_name) {
396 		DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name);
397 		sin6->sin6_family = AF_INET6;
398 		sin6->sin6_port = udp_hdr(skb)->source;
399 		sin6->sin6_flowinfo = 0;
400 
401 		if (is_udp4) {
402 			ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr,
403 					       &sin6->sin6_addr);
404 			sin6->sin6_scope_id = 0;
405 		} else {
406 			sin6->sin6_addr = ipv6_hdr(skb)->saddr;
407 			sin6->sin6_scope_id =
408 				ipv6_iface_scope_id(&sin6->sin6_addr,
409 						    inet6_iif(skb));
410 		}
411 		*addr_len = sizeof(*sin6);
412 
413 		BPF_CGROUP_RUN_PROG_UDP6_RECVMSG_LOCK(sk,
414 						      (struct sockaddr *)sin6,
415 						      addr_len);
416 	}
417 
418 	if (udp_test_bit(GRO_ENABLED, sk))
419 		udp_cmsg_recv(msg, sk, skb);
420 
421 	if (np->rxopt.all)
422 		ip6_datagram_recv_common_ctl(sk, msg, skb);
423 
424 	if (is_udp4) {
425 		if (inet_cmsg_flags(inet))
426 			ip_cmsg_recv_offset(msg, sk, skb,
427 					    sizeof(struct udphdr), off);
428 	} else {
429 		if (np->rxopt.all)
430 			ip6_datagram_recv_specific_ctl(sk, msg, skb);
431 	}
432 
433 	err = copied;
434 	if (flags & MSG_TRUNC)
435 		err = ulen;
436 
437 	skb_consume_udp(sk, skb, peeking ? -err : err);
438 	return err;
439 
440 csum_copy_err:
441 	if (!__sk_queue_drop_skb(sk, &udp_sk(sk)->reader_queue, skb, flags,
442 				 udp_skb_destructor)) {
443 		SNMP_INC_STATS(mib, UDP_MIB_CSUMERRORS);
444 		SNMP_INC_STATS(mib, UDP_MIB_INERRORS);
445 	}
446 	kfree_skb(skb);
447 
448 	/* starting over for a new packet, but check if we need to yield */
449 	cond_resched();
450 	msg->msg_flags &= ~MSG_TRUNC;
451 	goto try_again;
452 }
453 
454 DECLARE_STATIC_KEY_FALSE(udpv6_encap_needed_key);
udpv6_encap_enable(void)455 void udpv6_encap_enable(void)
456 {
457 	static_branch_inc(&udpv6_encap_needed_key);
458 }
459 EXPORT_SYMBOL(udpv6_encap_enable);
460 
461 /* Handler for tunnels with arbitrary destination ports: no socket lookup, go
462  * through error handlers in encapsulations looking for a match.
463  */
__udp6_lib_err_encap_no_sk(struct sk_buff * skb,struct inet6_skb_parm * opt,u8 type,u8 code,int offset,__be32 info)464 static int __udp6_lib_err_encap_no_sk(struct sk_buff *skb,
465 				      struct inet6_skb_parm *opt,
466 				      u8 type, u8 code, int offset, __be32 info)
467 {
468 	int i;
469 
470 	for (i = 0; i < MAX_IPTUN_ENCAP_OPS; i++) {
471 		int (*handler)(struct sk_buff *skb, struct inet6_skb_parm *opt,
472 			       u8 type, u8 code, int offset, __be32 info);
473 		const struct ip6_tnl_encap_ops *encap;
474 
475 		encap = rcu_dereference(ip6tun_encaps[i]);
476 		if (!encap)
477 			continue;
478 		handler = encap->err_handler;
479 		if (handler && !handler(skb, opt, type, code, offset, info))
480 			return 0;
481 	}
482 
483 	return -ENOENT;
484 }
485 
486 /* Try to match ICMP errors to UDP tunnels by looking up a socket without
487  * reversing source and destination port: this will match tunnels that force the
488  * same destination port on both endpoints (e.g. VXLAN, GENEVE). Note that
489  * lwtunnels might actually break this assumption by being configured with
490  * different destination ports on endpoints, in this case we won't be able to
491  * trace ICMP messages back to them.
492  *
493  * If this doesn't match any socket, probe tunnels with arbitrary destination
494  * ports (e.g. FoU, GUE): there, the receiving socket is useless, as the port
495  * we've sent packets to won't necessarily match the local destination port.
496  *
497  * Then ask the tunnel implementation to match the error against a valid
498  * association.
499  *
500  * Return an error if we can't find a match, the socket if we need further
501  * processing, zero otherwise.
502  */
__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)503 static struct sock *__udp6_lib_err_encap(struct net *net,
504 					 const struct ipv6hdr *hdr, int offset,
505 					 struct udphdr *uh,
506 					 struct udp_table *udptable,
507 					 struct sock *sk,
508 					 struct sk_buff *skb,
509 					 struct inet6_skb_parm *opt,
510 					 u8 type, u8 code, __be32 info)
511 {
512 	int (*lookup)(struct sock *sk, struct sk_buff *skb);
513 	int network_offset, transport_offset;
514 	struct udp_sock *up;
515 
516 	network_offset = skb_network_offset(skb);
517 	transport_offset = skb_transport_offset(skb);
518 
519 	/* Network header needs to point to the outer IPv6 header inside ICMP */
520 	skb_reset_network_header(skb);
521 
522 	/* Transport header needs to point to the UDP header */
523 	skb_set_transport_header(skb, offset);
524 
525 	if (sk) {
526 		up = udp_sk(sk);
527 
528 		lookup = READ_ONCE(up->encap_err_lookup);
529 		if (lookup && lookup(sk, skb))
530 			sk = NULL;
531 
532 		goto out;
533 	}
534 
535 	sk = __udp6_lib_lookup(net, &hdr->daddr, uh->source,
536 			       &hdr->saddr, uh->dest,
537 			       inet6_iif(skb), 0, udptable, skb);
538 	if (sk) {
539 		up = udp_sk(sk);
540 
541 		lookup = READ_ONCE(up->encap_err_lookup);
542 		if (!lookup || lookup(sk, skb))
543 			sk = NULL;
544 	}
545 
546 out:
547 	if (!sk) {
548 		sk = ERR_PTR(__udp6_lib_err_encap_no_sk(skb, opt, type, code,
549 							offset, info));
550 	}
551 
552 	skb_set_transport_header(skb, transport_offset);
553 	skb_set_network_header(skb, network_offset);
554 
555 	return sk;
556 }
557 
__udp6_lib_err(struct sk_buff * skb,struct inet6_skb_parm * opt,u8 type,u8 code,int offset,__be32 info,struct udp_table * udptable)558 int __udp6_lib_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
559 		   u8 type, u8 code, int offset, __be32 info,
560 		   struct udp_table *udptable)
561 {
562 	struct ipv6_pinfo *np;
563 	const struct ipv6hdr *hdr = (const struct ipv6hdr *)skb->data;
564 	const struct in6_addr *saddr = &hdr->saddr;
565 	const struct in6_addr *daddr = seg6_get_daddr(skb, opt) ? : &hdr->daddr;
566 	struct udphdr *uh = (struct udphdr *)(skb->data+offset);
567 	bool tunnel = false;
568 	struct sock *sk;
569 	int harderr;
570 	int err;
571 	struct net *net = dev_net(skb->dev);
572 
573 	sk = __udp6_lib_lookup(net, daddr, uh->dest, saddr, uh->source,
574 			       inet6_iif(skb), inet6_sdif(skb), udptable, NULL);
575 
576 	if (!sk || READ_ONCE(udp_sk(sk)->encap_type)) {
577 		/* No socket for error: try tunnels before discarding */
578 		if (static_branch_unlikely(&udpv6_encap_needed_key)) {
579 			sk = __udp6_lib_err_encap(net, hdr, offset, uh,
580 						  udptable, sk, skb,
581 						  opt, type, code, info);
582 			if (!sk)
583 				return 0;
584 		} else
585 			sk = ERR_PTR(-ENOENT);
586 
587 		if (IS_ERR(sk)) {
588 			__ICMP6_INC_STATS(net, __in6_dev_get(skb->dev),
589 					  ICMP6_MIB_INERRORS);
590 			return PTR_ERR(sk);
591 		}
592 
593 		tunnel = true;
594 	}
595 
596 	harderr = icmpv6_err_convert(type, code, &err);
597 	np = inet6_sk(sk);
598 
599 	if (type == ICMPV6_PKT_TOOBIG) {
600 		if (!ip6_sk_accept_pmtu(sk))
601 			goto out;
602 		ip6_sk_update_pmtu(skb, sk, info);
603 		if (np->pmtudisc != IPV6_PMTUDISC_DONT)
604 			harderr = 1;
605 	}
606 	if (type == NDISC_REDIRECT) {
607 		if (tunnel) {
608 			ip6_redirect(skb, sock_net(sk), inet6_iif(skb),
609 				     READ_ONCE(sk->sk_mark), sk->sk_uid);
610 		} else {
611 			ip6_sk_redirect(skb, sk);
612 		}
613 		goto out;
614 	}
615 
616 	/* Tunnels don't have an application socket: don't pass errors back */
617 	if (tunnel) {
618 		if (udp_sk(sk)->encap_err_rcv)
619 			udp_sk(sk)->encap_err_rcv(sk, skb, err, uh->dest,
620 						  ntohl(info), (u8 *)(uh+1));
621 		goto out;
622 	}
623 
624 	if (!np->recverr) {
625 		if (!harderr || sk->sk_state != TCP_ESTABLISHED)
626 			goto out;
627 	} else {
628 		ipv6_icmp_error(sk, skb, err, uh->dest, ntohl(info), (u8 *)(uh+1));
629 	}
630 
631 	sk->sk_err = err;
632 	sk_error_report(sk);
633 out:
634 	return 0;
635 }
636 
__udpv6_queue_rcv_skb(struct sock * sk,struct sk_buff * skb)637 static int __udpv6_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
638 {
639 	int rc;
640 
641 	if (!ipv6_addr_any(&sk->sk_v6_daddr)) {
642 		sock_rps_save_rxhash(sk, skb);
643 		sk_mark_napi_id(sk, skb);
644 		sk_incoming_cpu_update(sk);
645 	} else {
646 		sk_mark_napi_id_once(sk, skb);
647 	}
648 
649 	rc = __udp_enqueue_schedule_skb(sk, skb);
650 	if (rc < 0) {
651 		int is_udplite = IS_UDPLITE(sk);
652 		enum skb_drop_reason drop_reason;
653 
654 		/* Note that an ENOMEM error is charged twice */
655 		if (rc == -ENOMEM) {
656 			UDP6_INC_STATS(sock_net(sk),
657 					 UDP_MIB_RCVBUFERRORS, is_udplite);
658 			drop_reason = SKB_DROP_REASON_SOCKET_RCVBUFF;
659 		} else {
660 			UDP6_INC_STATS(sock_net(sk),
661 				       UDP_MIB_MEMERRORS, is_udplite);
662 			drop_reason = SKB_DROP_REASON_PROTO_MEM;
663 		}
664 		UDP6_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
665 		kfree_skb_reason(skb, drop_reason);
666 		trace_udp_fail_queue_rcv_skb(rc, sk);
667 		return -1;
668 	}
669 
670 	return 0;
671 }
672 
udpv6_err(struct sk_buff * skb,struct inet6_skb_parm * opt,u8 type,u8 code,int offset,__be32 info)673 static __inline__ int udpv6_err(struct sk_buff *skb,
674 				struct inet6_skb_parm *opt, u8 type,
675 				u8 code, int offset, __be32 info)
676 {
677 	return __udp6_lib_err(skb, opt, type, code, offset, info,
678 			      dev_net(skb->dev)->ipv4.udp_table);
679 }
680 
udpv6_queue_rcv_one_skb(struct sock * sk,struct sk_buff * skb)681 static int udpv6_queue_rcv_one_skb(struct sock *sk, struct sk_buff *skb)
682 {
683 	enum skb_drop_reason drop_reason = SKB_DROP_REASON_NOT_SPECIFIED;
684 	struct udp_sock *up = udp_sk(sk);
685 	int is_udplite = IS_UDPLITE(sk);
686 
687 	if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb)) {
688 		drop_reason = SKB_DROP_REASON_XFRM_POLICY;
689 		goto drop;
690 	}
691 	nf_reset_ct(skb);
692 
693 	if (static_branch_unlikely(&udpv6_encap_needed_key) &&
694 	    READ_ONCE(up->encap_type)) {
695 		int (*encap_rcv)(struct sock *sk, struct sk_buff *skb);
696 
697 		/*
698 		 * This is an encapsulation socket so pass the skb to
699 		 * the socket's udp_encap_rcv() hook. Otherwise, just
700 		 * fall through and pass this up the UDP socket.
701 		 * up->encap_rcv() returns the following value:
702 		 * =0 if skb was successfully passed to the encap
703 		 *    handler or was discarded by it.
704 		 * >0 if skb should be passed on to UDP.
705 		 * <0 if skb should be resubmitted as proto -N
706 		 */
707 
708 		/* if we're overly short, let UDP handle it */
709 		encap_rcv = READ_ONCE(up->encap_rcv);
710 		if (encap_rcv) {
711 			int ret;
712 
713 			/* Verify checksum before giving to encap */
714 			if (udp_lib_checksum_complete(skb))
715 				goto csum_error;
716 
717 			ret = encap_rcv(sk, skb);
718 			if (ret <= 0) {
719 				__UDP6_INC_STATS(sock_net(sk),
720 						 UDP_MIB_INDATAGRAMS,
721 						 is_udplite);
722 				return -ret;
723 			}
724 		}
725 
726 		/* FALLTHROUGH -- it's a UDP Packet */
727 	}
728 
729 	/*
730 	 * UDP-Lite specific tests, ignored on UDP sockets (see net/ipv4/udp.c).
731 	 */
732 	if (udp_test_bit(UDPLITE_RECV_CC, sk) && UDP_SKB_CB(skb)->partial_cov) {
733 		u16 pcrlen = READ_ONCE(up->pcrlen);
734 
735 		if (pcrlen == 0) {          /* full coverage was set  */
736 			net_dbg_ratelimited("UDPLITE6: partial coverage %d while full coverage %d requested\n",
737 					    UDP_SKB_CB(skb)->cscov, skb->len);
738 			goto drop;
739 		}
740 		if (UDP_SKB_CB(skb)->cscov < pcrlen) {
741 			net_dbg_ratelimited("UDPLITE6: coverage %d too small, need min %d\n",
742 					    UDP_SKB_CB(skb)->cscov, pcrlen);
743 			goto drop;
744 		}
745 	}
746 
747 	prefetch(&sk->sk_rmem_alloc);
748 	if (rcu_access_pointer(sk->sk_filter) &&
749 	    udp_lib_checksum_complete(skb))
750 		goto csum_error;
751 
752 	if (sk_filter_trim_cap(sk, skb, sizeof(struct udphdr))) {
753 		drop_reason = SKB_DROP_REASON_SOCKET_FILTER;
754 		goto drop;
755 	}
756 
757 	udp_csum_pull_header(skb);
758 
759 	skb_dst_drop(skb);
760 
761 	return __udpv6_queue_rcv_skb(sk, skb);
762 
763 csum_error:
764 	drop_reason = SKB_DROP_REASON_UDP_CSUM;
765 	__UDP6_INC_STATS(sock_net(sk), UDP_MIB_CSUMERRORS, is_udplite);
766 drop:
767 	__UDP6_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
768 	atomic_inc(&sk->sk_drops);
769 	kfree_skb_reason(skb, drop_reason);
770 	return -1;
771 }
772 
udpv6_queue_rcv_skb(struct sock * sk,struct sk_buff * skb)773 static int udpv6_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
774 {
775 	struct sk_buff *next, *segs;
776 	int ret;
777 
778 	if (likely(!udp_unexpected_gso(sk, skb)))
779 		return udpv6_queue_rcv_one_skb(sk, skb);
780 
781 	__skb_push(skb, -skb_mac_offset(skb));
782 	segs = udp_rcv_segment(sk, skb, false);
783 	skb_list_walk_safe(segs, skb, next) {
784 		__skb_pull(skb, skb_transport_offset(skb));
785 
786 		udp_post_segment_fix_csum(skb);
787 		ret = udpv6_queue_rcv_one_skb(sk, skb);
788 		if (ret > 0)
789 			ip6_protocol_deliver_rcu(dev_net(skb->dev), skb, ret,
790 						 true);
791 	}
792 	return 0;
793 }
794 
__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)795 static bool __udp_v6_is_mcast_sock(struct net *net, const struct sock *sk,
796 				   __be16 loc_port, const struct in6_addr *loc_addr,
797 				   __be16 rmt_port, const struct in6_addr *rmt_addr,
798 				   int dif, int sdif, unsigned short hnum)
799 {
800 	const struct inet_sock *inet = inet_sk(sk);
801 
802 	if (!net_eq(sock_net(sk), net))
803 		return false;
804 
805 	if (udp_sk(sk)->udp_port_hash != hnum ||
806 	    sk->sk_family != PF_INET6 ||
807 	    (inet->inet_dport && inet->inet_dport != rmt_port) ||
808 	    (!ipv6_addr_any(&sk->sk_v6_daddr) &&
809 		    !ipv6_addr_equal(&sk->sk_v6_daddr, rmt_addr)) ||
810 	    !udp_sk_bound_dev_eq(net, READ_ONCE(sk->sk_bound_dev_if), dif, sdif) ||
811 	    (!ipv6_addr_any(&sk->sk_v6_rcv_saddr) &&
812 		    !ipv6_addr_equal(&sk->sk_v6_rcv_saddr, loc_addr)))
813 		return false;
814 	if (!inet6_mc_check(sk, loc_addr, rmt_addr))
815 		return false;
816 	return true;
817 }
818 
udp6_csum_zero_error(struct sk_buff * skb)819 static void udp6_csum_zero_error(struct sk_buff *skb)
820 {
821 	/* RFC 2460 section 8.1 says that we SHOULD log
822 	 * this error. Well, it is reasonable.
823 	 */
824 	net_dbg_ratelimited("IPv6: udp checksum is 0 for [%pI6c]:%u->[%pI6c]:%u\n",
825 			    &ipv6_hdr(skb)->saddr, ntohs(udp_hdr(skb)->source),
826 			    &ipv6_hdr(skb)->daddr, ntohs(udp_hdr(skb)->dest));
827 }
828 
829 /*
830  * Note: called only from the BH handler context,
831  * so we don't need to lock the hashes.
832  */
__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)833 static int __udp6_lib_mcast_deliver(struct net *net, struct sk_buff *skb,
834 		const struct in6_addr *saddr, const struct in6_addr *daddr,
835 		struct udp_table *udptable, int proto)
836 {
837 	struct sock *sk, *first = NULL;
838 	const struct udphdr *uh = udp_hdr(skb);
839 	unsigned short hnum = ntohs(uh->dest);
840 	struct udp_hslot *hslot = udp_hashslot(udptable, net, hnum);
841 	unsigned int offset = offsetof(typeof(*sk), sk_node);
842 	unsigned int hash2 = 0, hash2_any = 0, use_hash2 = (hslot->count > 10);
843 	int dif = inet6_iif(skb);
844 	int sdif = inet6_sdif(skb);
845 	struct hlist_node *node;
846 	struct sk_buff *nskb;
847 
848 	if (use_hash2) {
849 		hash2_any = ipv6_portaddr_hash(net, &in6addr_any, hnum) &
850 			    udptable->mask;
851 		hash2 = ipv6_portaddr_hash(net, daddr, hnum) & udptable->mask;
852 start_lookup:
853 		hslot = &udptable->hash2[hash2];
854 		offset = offsetof(typeof(*sk), __sk_common.skc_portaddr_node);
855 	}
856 
857 	sk_for_each_entry_offset_rcu(sk, node, &hslot->head, offset) {
858 		if (!__udp_v6_is_mcast_sock(net, sk, uh->dest, daddr,
859 					    uh->source, saddr, dif, sdif,
860 					    hnum))
861 			continue;
862 		/* If zero checksum and no_check is not on for
863 		 * the socket then skip it.
864 		 */
865 		if (!uh->check && !udp_get_no_check6_rx(sk))
866 			continue;
867 		if (!first) {
868 			first = sk;
869 			continue;
870 		}
871 		nskb = skb_clone(skb, GFP_ATOMIC);
872 		if (unlikely(!nskb)) {
873 			atomic_inc(&sk->sk_drops);
874 			__UDP6_INC_STATS(net, UDP_MIB_RCVBUFERRORS,
875 					 IS_UDPLITE(sk));
876 			__UDP6_INC_STATS(net, UDP_MIB_INERRORS,
877 					 IS_UDPLITE(sk));
878 			continue;
879 		}
880 
881 		if (udpv6_queue_rcv_skb(sk, nskb) > 0)
882 			consume_skb(nskb);
883 	}
884 
885 	/* Also lookup *:port if we are using hash2 and haven't done so yet. */
886 	if (use_hash2 && hash2 != hash2_any) {
887 		hash2 = hash2_any;
888 		goto start_lookup;
889 	}
890 
891 	if (first) {
892 		if (udpv6_queue_rcv_skb(first, skb) > 0)
893 			consume_skb(skb);
894 	} else {
895 		kfree_skb(skb);
896 		__UDP6_INC_STATS(net, UDP_MIB_IGNOREDMULTI,
897 				 proto == IPPROTO_UDPLITE);
898 	}
899 	return 0;
900 }
901 
udp6_sk_rx_dst_set(struct sock * sk,struct dst_entry * dst)902 static void udp6_sk_rx_dst_set(struct sock *sk, struct dst_entry *dst)
903 {
904 	if (udp_sk_rx_dst_set(sk, dst)) {
905 		const struct rt6_info *rt = (const struct rt6_info *)dst;
906 
907 		sk->sk_rx_dst_cookie = rt6_get_cookie(rt);
908 	}
909 }
910 
911 /* wrapper for udp_queue_rcv_skb tacking care of csum conversion and
912  * return code conversion for ip layer consumption
913  */
udp6_unicast_rcv_skb(struct sock * sk,struct sk_buff * skb,struct udphdr * uh)914 static int udp6_unicast_rcv_skb(struct sock *sk, struct sk_buff *skb,
915 				struct udphdr *uh)
916 {
917 	int ret;
918 
919 	if (inet_get_convert_csum(sk) && uh->check && !IS_UDPLITE(sk))
920 		skb_checksum_try_convert(skb, IPPROTO_UDP, ip6_compute_pseudo);
921 
922 	ret = udpv6_queue_rcv_skb(sk, skb);
923 
924 	/* a return value > 0 means to resubmit the input */
925 	if (ret > 0)
926 		return ret;
927 	return 0;
928 }
929 
__udp6_lib_rcv(struct sk_buff * skb,struct udp_table * udptable,int proto)930 int __udp6_lib_rcv(struct sk_buff *skb, struct udp_table *udptable,
931 		   int proto)
932 {
933 	enum skb_drop_reason reason = SKB_DROP_REASON_NOT_SPECIFIED;
934 	const struct in6_addr *saddr, *daddr;
935 	struct net *net = dev_net(skb->dev);
936 	struct udphdr *uh;
937 	struct sock *sk;
938 	bool refcounted;
939 	u32 ulen = 0;
940 
941 	if (!pskb_may_pull(skb, sizeof(struct udphdr)))
942 		goto discard;
943 
944 	saddr = &ipv6_hdr(skb)->saddr;
945 	daddr = &ipv6_hdr(skb)->daddr;
946 	uh = udp_hdr(skb);
947 
948 	ulen = ntohs(uh->len);
949 	if (ulen > skb->len)
950 		goto short_packet;
951 
952 	if (proto == IPPROTO_UDP) {
953 		/* UDP validates ulen. */
954 
955 		/* Check for jumbo payload */
956 		if (ulen == 0)
957 			ulen = skb->len;
958 
959 		if (ulen < sizeof(*uh))
960 			goto short_packet;
961 
962 		if (ulen < skb->len) {
963 			if (pskb_trim_rcsum(skb, ulen))
964 				goto short_packet;
965 			saddr = &ipv6_hdr(skb)->saddr;
966 			daddr = &ipv6_hdr(skb)->daddr;
967 			uh = udp_hdr(skb);
968 		}
969 	}
970 
971 	if (udp6_csum_init(skb, uh, proto))
972 		goto csum_error;
973 
974 	/* Check if the socket is already available, e.g. due to early demux */
975 	sk = inet6_steal_sock(net, skb, sizeof(struct udphdr), saddr, uh->source, daddr, uh->dest,
976 			      &refcounted, udp6_ehashfn);
977 	if (IS_ERR(sk))
978 		goto no_sk;
979 
980 	if (sk) {
981 		struct dst_entry *dst = skb_dst(skb);
982 		int ret;
983 
984 		if (unlikely(rcu_dereference(sk->sk_rx_dst) != dst))
985 			udp6_sk_rx_dst_set(sk, dst);
986 
987 		if (!uh->check && !udp_get_no_check6_rx(sk)) {
988 			if (refcounted)
989 				sock_put(sk);
990 			goto report_csum_error;
991 		}
992 
993 		ret = udp6_unicast_rcv_skb(sk, skb, uh);
994 		if (refcounted)
995 			sock_put(sk);
996 		return ret;
997 	}
998 
999 	/*
1000 	 *	Multicast receive code
1001 	 */
1002 	if (ipv6_addr_is_multicast(daddr))
1003 		return __udp6_lib_mcast_deliver(net, skb,
1004 				saddr, daddr, udptable, proto);
1005 
1006 	/* Unicast */
1007 	sk = __udp6_lib_lookup_skb(skb, uh->source, uh->dest, udptable);
1008 	if (sk) {
1009 		if (!uh->check && !udp_get_no_check6_rx(sk))
1010 			goto report_csum_error;
1011 		return udp6_unicast_rcv_skb(sk, skb, uh);
1012 	}
1013 no_sk:
1014 	reason = SKB_DROP_REASON_NO_SOCKET;
1015 
1016 	if (!uh->check)
1017 		goto report_csum_error;
1018 
1019 	if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
1020 		goto discard;
1021 	nf_reset_ct(skb);
1022 
1023 	if (udp_lib_checksum_complete(skb))
1024 		goto csum_error;
1025 
1026 	__UDP6_INC_STATS(net, UDP_MIB_NOPORTS, proto == IPPROTO_UDPLITE);
1027 	icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0);
1028 
1029 	kfree_skb_reason(skb, reason);
1030 	return 0;
1031 
1032 short_packet:
1033 	if (reason == SKB_DROP_REASON_NOT_SPECIFIED)
1034 		reason = SKB_DROP_REASON_PKT_TOO_SMALL;
1035 	net_dbg_ratelimited("UDP%sv6: short packet: From [%pI6c]:%u %d/%d to [%pI6c]:%u\n",
1036 			    proto == IPPROTO_UDPLITE ? "-Lite" : "",
1037 			    saddr, ntohs(uh->source),
1038 			    ulen, skb->len,
1039 			    daddr, ntohs(uh->dest));
1040 	goto discard;
1041 
1042 report_csum_error:
1043 	udp6_csum_zero_error(skb);
1044 csum_error:
1045 	if (reason == SKB_DROP_REASON_NOT_SPECIFIED)
1046 		reason = SKB_DROP_REASON_UDP_CSUM;
1047 	__UDP6_INC_STATS(net, UDP_MIB_CSUMERRORS, proto == IPPROTO_UDPLITE);
1048 discard:
1049 	__UDP6_INC_STATS(net, UDP_MIB_INERRORS, proto == IPPROTO_UDPLITE);
1050 	kfree_skb_reason(skb, reason);
1051 	return 0;
1052 }
1053 
1054 
__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)1055 static struct sock *__udp6_lib_demux_lookup(struct net *net,
1056 			__be16 loc_port, const struct in6_addr *loc_addr,
1057 			__be16 rmt_port, const struct in6_addr *rmt_addr,
1058 			int dif, int sdif)
1059 {
1060 	struct udp_table *udptable = net->ipv4.udp_table;
1061 	unsigned short hnum = ntohs(loc_port);
1062 	unsigned int hash2, slot2;
1063 	struct udp_hslot *hslot2;
1064 	__portpair ports;
1065 	struct sock *sk;
1066 
1067 	hash2 = ipv6_portaddr_hash(net, loc_addr, hnum);
1068 	slot2 = hash2 & udptable->mask;
1069 	hslot2 = &udptable->hash2[slot2];
1070 	ports = INET_COMBINED_PORTS(rmt_port, hnum);
1071 
1072 	udp_portaddr_for_each_entry_rcu(sk, &hslot2->head) {
1073 		if (sk->sk_state == TCP_ESTABLISHED &&
1074 		    inet6_match(net, sk, rmt_addr, loc_addr, ports, dif, sdif))
1075 			return sk;
1076 		/* Only check first socket in chain */
1077 		break;
1078 	}
1079 	return NULL;
1080 }
1081 
udp_v6_early_demux(struct sk_buff * skb)1082 void udp_v6_early_demux(struct sk_buff *skb)
1083 {
1084 	struct net *net = dev_net(skb->dev);
1085 	const struct udphdr *uh;
1086 	struct sock *sk;
1087 	struct dst_entry *dst;
1088 	int dif = skb->dev->ifindex;
1089 	int sdif = inet6_sdif(skb);
1090 
1091 	if (!pskb_may_pull(skb, skb_transport_offset(skb) +
1092 	    sizeof(struct udphdr)))
1093 		return;
1094 
1095 	uh = udp_hdr(skb);
1096 
1097 	if (skb->pkt_type == PACKET_HOST)
1098 		sk = __udp6_lib_demux_lookup(net, uh->dest,
1099 					     &ipv6_hdr(skb)->daddr,
1100 					     uh->source, &ipv6_hdr(skb)->saddr,
1101 					     dif, sdif);
1102 	else
1103 		return;
1104 
1105 	if (!sk || !refcount_inc_not_zero(&sk->sk_refcnt))
1106 		return;
1107 
1108 	skb->sk = sk;
1109 	skb->destructor = sock_efree;
1110 	dst = rcu_dereference(sk->sk_rx_dst);
1111 
1112 	if (dst)
1113 		dst = dst_check(dst, sk->sk_rx_dst_cookie);
1114 	if (dst) {
1115 		/* set noref for now.
1116 		 * any place which wants to hold dst has to call
1117 		 * dst_hold_safe()
1118 		 */
1119 		skb_dst_set_noref(skb, dst);
1120 	}
1121 }
1122 
udpv6_rcv(struct sk_buff * skb)1123 INDIRECT_CALLABLE_SCOPE int udpv6_rcv(struct sk_buff *skb)
1124 {
1125 	return __udp6_lib_rcv(skb, dev_net(skb->dev)->ipv4.udp_table, IPPROTO_UDP);
1126 }
1127 
1128 /*
1129  * Throw away all pending data and cancel the corking. Socket is locked.
1130  */
udp_v6_flush_pending_frames(struct sock * sk)1131 static void udp_v6_flush_pending_frames(struct sock *sk)
1132 {
1133 	struct udp_sock *up = udp_sk(sk);
1134 
1135 	if (up->pending == AF_INET)
1136 		udp_flush_pending_frames(sk);
1137 	else if (up->pending) {
1138 		up->len = 0;
1139 		WRITE_ONCE(up->pending, 0);
1140 		ip6_flush_pending_frames(sk);
1141 	}
1142 }
1143 
udpv6_pre_connect(struct sock * sk,struct sockaddr * uaddr,int addr_len)1144 static int udpv6_pre_connect(struct sock *sk, struct sockaddr *uaddr,
1145 			     int addr_len)
1146 {
1147 	if (addr_len < offsetofend(struct sockaddr, sa_family))
1148 		return -EINVAL;
1149 	/* The following checks are replicated from __ip6_datagram_connect()
1150 	 * and intended to prevent BPF program called below from accessing
1151 	 * bytes that are out of the bound specified by user in addr_len.
1152 	 */
1153 	if (uaddr->sa_family == AF_INET) {
1154 		if (ipv6_only_sock(sk))
1155 			return -EAFNOSUPPORT;
1156 		return udp_pre_connect(sk, uaddr, addr_len);
1157 	}
1158 
1159 	if (addr_len < SIN6_LEN_RFC2133)
1160 		return -EINVAL;
1161 
1162 	return BPF_CGROUP_RUN_PROG_INET6_CONNECT_LOCK(sk, uaddr, &addr_len);
1163 }
1164 
1165 /**
1166  *	udp6_hwcsum_outgoing  -  handle outgoing HW checksumming
1167  *	@sk:	socket we are sending on
1168  *	@skb:	sk_buff containing the filled-in UDP header
1169  *		(checksum field must be zeroed out)
1170  *	@saddr: source address
1171  *	@daddr: destination address
1172  *	@len:	length of packet
1173  */
udp6_hwcsum_outgoing(struct sock * sk,struct sk_buff * skb,const struct in6_addr * saddr,const struct in6_addr * daddr,int len)1174 static void udp6_hwcsum_outgoing(struct sock *sk, struct sk_buff *skb,
1175 				 const struct in6_addr *saddr,
1176 				 const struct in6_addr *daddr, int len)
1177 {
1178 	unsigned int offset;
1179 	struct udphdr *uh = udp_hdr(skb);
1180 	struct sk_buff *frags = skb_shinfo(skb)->frag_list;
1181 	__wsum csum = 0;
1182 
1183 	if (!frags) {
1184 		/* Only one fragment on the socket.  */
1185 		skb->csum_start = skb_transport_header(skb) - skb->head;
1186 		skb->csum_offset = offsetof(struct udphdr, check);
1187 		uh->check = ~csum_ipv6_magic(saddr, daddr, len, IPPROTO_UDP, 0);
1188 	} else {
1189 		/*
1190 		 * HW-checksum won't work as there are two or more
1191 		 * fragments on the socket so that all csums of sk_buffs
1192 		 * should be together
1193 		 */
1194 		offset = skb_transport_offset(skb);
1195 		skb->csum = skb_checksum(skb, offset, skb->len - offset, 0);
1196 		csum = skb->csum;
1197 
1198 		skb->ip_summed = CHECKSUM_NONE;
1199 
1200 		do {
1201 			csum = csum_add(csum, frags->csum);
1202 		} while ((frags = frags->next));
1203 
1204 		uh->check = csum_ipv6_magic(saddr, daddr, len, IPPROTO_UDP,
1205 					    csum);
1206 		if (uh->check == 0)
1207 			uh->check = CSUM_MANGLED_0;
1208 	}
1209 }
1210 
1211 /*
1212  *	Sending
1213  */
1214 
udp_v6_send_skb(struct sk_buff * skb,struct flowi6 * fl6,struct inet_cork * cork)1215 static int udp_v6_send_skb(struct sk_buff *skb, struct flowi6 *fl6,
1216 			   struct inet_cork *cork)
1217 {
1218 	struct sock *sk = skb->sk;
1219 	struct udphdr *uh;
1220 	int err = 0;
1221 	int is_udplite = IS_UDPLITE(sk);
1222 	__wsum csum = 0;
1223 	int offset = skb_transport_offset(skb);
1224 	int len = skb->len - offset;
1225 	int datalen = len - sizeof(*uh);
1226 
1227 	/*
1228 	 * Create a UDP header
1229 	 */
1230 	uh = udp_hdr(skb);
1231 	uh->source = fl6->fl6_sport;
1232 	uh->dest = fl6->fl6_dport;
1233 	uh->len = htons(len);
1234 	uh->check = 0;
1235 
1236 	if (cork->gso_size) {
1237 		const int hlen = skb_network_header_len(skb) +
1238 				 sizeof(struct udphdr);
1239 
1240 		if (hlen + cork->gso_size > cork->fragsize) {
1241 			kfree_skb(skb);
1242 			return -EINVAL;
1243 		}
1244 		if (datalen > cork->gso_size * UDP_MAX_SEGMENTS) {
1245 			kfree_skb(skb);
1246 			return -EINVAL;
1247 		}
1248 		if (udp_get_no_check6_tx(sk)) {
1249 			kfree_skb(skb);
1250 			return -EINVAL;
1251 		}
1252 		if (skb->ip_summed != CHECKSUM_PARTIAL || is_udplite ||
1253 		    dst_xfrm(skb_dst(skb))) {
1254 			kfree_skb(skb);
1255 			return -EIO;
1256 		}
1257 
1258 		if (datalen > cork->gso_size) {
1259 			skb_shinfo(skb)->gso_size = cork->gso_size;
1260 			skb_shinfo(skb)->gso_type = SKB_GSO_UDP_L4;
1261 			skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(datalen,
1262 								 cork->gso_size);
1263 		}
1264 		goto csum_partial;
1265 	}
1266 
1267 	if (is_udplite)
1268 		csum = udplite_csum(skb);
1269 	else if (udp_get_no_check6_tx(sk)) {   /* UDP csum disabled */
1270 		skb->ip_summed = CHECKSUM_NONE;
1271 		goto send;
1272 	} else if (skb->ip_summed == CHECKSUM_PARTIAL) { /* UDP hardware csum */
1273 csum_partial:
1274 		udp6_hwcsum_outgoing(sk, skb, &fl6->saddr, &fl6->daddr, len);
1275 		goto send;
1276 	} else
1277 		csum = udp_csum(skb);
1278 
1279 	/* add protocol-dependent pseudo-header */
1280 	uh->check = csum_ipv6_magic(&fl6->saddr, &fl6->daddr,
1281 				    len, fl6->flowi6_proto, csum);
1282 	if (uh->check == 0)
1283 		uh->check = CSUM_MANGLED_0;
1284 
1285 send:
1286 	err = ip6_send_skb(skb);
1287 	if (err) {
1288 		if (err == -ENOBUFS && !inet6_sk(sk)->recverr) {
1289 			UDP6_INC_STATS(sock_net(sk),
1290 				       UDP_MIB_SNDBUFERRORS, is_udplite);
1291 			err = 0;
1292 		}
1293 	} else {
1294 		UDP6_INC_STATS(sock_net(sk),
1295 			       UDP_MIB_OUTDATAGRAMS, is_udplite);
1296 	}
1297 	return err;
1298 }
1299 
udp_v6_push_pending_frames(struct sock * sk)1300 static int udp_v6_push_pending_frames(struct sock *sk)
1301 {
1302 	struct sk_buff *skb;
1303 	struct udp_sock  *up = udp_sk(sk);
1304 	int err = 0;
1305 
1306 	if (up->pending == AF_INET)
1307 		return udp_push_pending_frames(sk);
1308 
1309 	skb = ip6_finish_skb(sk);
1310 	if (!skb)
1311 		goto out;
1312 
1313 	err = udp_v6_send_skb(skb, &inet_sk(sk)->cork.fl.u.ip6,
1314 			      &inet_sk(sk)->cork.base);
1315 out:
1316 	up->len = 0;
1317 	WRITE_ONCE(up->pending, 0);
1318 	return err;
1319 }
1320 
udpv6_sendmsg(struct sock * sk,struct msghdr * msg,size_t len)1321 int udpv6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
1322 {
1323 	struct ipv6_txoptions opt_space;
1324 	struct udp_sock *up = udp_sk(sk);
1325 	struct inet_sock *inet = inet_sk(sk);
1326 	struct ipv6_pinfo *np = inet6_sk(sk);
1327 	DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name);
1328 	struct in6_addr *daddr, *final_p, final;
1329 	struct ipv6_txoptions *opt = NULL;
1330 	struct ipv6_txoptions *opt_to_free = NULL;
1331 	struct ip6_flowlabel *flowlabel = NULL;
1332 	struct inet_cork_full cork;
1333 	struct flowi6 *fl6 = &cork.fl.u.ip6;
1334 	struct dst_entry *dst;
1335 	struct ipcm6_cookie ipc6;
1336 	int addr_len = msg->msg_namelen;
1337 	bool connected = false;
1338 	int ulen = len;
1339 	int corkreq = udp_test_bit(CORK, sk) || msg->msg_flags & MSG_MORE;
1340 	int err;
1341 	int is_udplite = IS_UDPLITE(sk);
1342 	int (*getfrag)(void *, char *, int, int, int, struct sk_buff *);
1343 
1344 	ipcm6_init(&ipc6);
1345 	ipc6.gso_size = READ_ONCE(up->gso_size);
1346 	ipc6.sockc.tsflags = READ_ONCE(sk->sk_tsflags);
1347 	ipc6.sockc.mark = READ_ONCE(sk->sk_mark);
1348 
1349 	/* destination address check */
1350 	if (sin6) {
1351 		if (addr_len < offsetof(struct sockaddr, sa_data))
1352 			return -EINVAL;
1353 
1354 		switch (sin6->sin6_family) {
1355 		case AF_INET6:
1356 			if (addr_len < SIN6_LEN_RFC2133)
1357 				return -EINVAL;
1358 			daddr = &sin6->sin6_addr;
1359 			if (ipv6_addr_any(daddr) &&
1360 			    ipv6_addr_v4mapped(&np->saddr))
1361 				ipv6_addr_set_v4mapped(htonl(INADDR_LOOPBACK),
1362 						       daddr);
1363 			break;
1364 		case AF_INET:
1365 			goto do_udp_sendmsg;
1366 		case AF_UNSPEC:
1367 			msg->msg_name = sin6 = NULL;
1368 			msg->msg_namelen = addr_len = 0;
1369 			daddr = NULL;
1370 			break;
1371 		default:
1372 			return -EINVAL;
1373 		}
1374 	} else if (!READ_ONCE(up->pending)) {
1375 		if (sk->sk_state != TCP_ESTABLISHED)
1376 			return -EDESTADDRREQ;
1377 		daddr = &sk->sk_v6_daddr;
1378 	} else
1379 		daddr = NULL;
1380 
1381 	if (daddr) {
1382 		if (ipv6_addr_v4mapped(daddr)) {
1383 			struct sockaddr_in sin;
1384 			sin.sin_family = AF_INET;
1385 			sin.sin_port = sin6 ? sin6->sin6_port : inet->inet_dport;
1386 			sin.sin_addr.s_addr = daddr->s6_addr32[3];
1387 			msg->msg_name = &sin;
1388 			msg->msg_namelen = sizeof(sin);
1389 do_udp_sendmsg:
1390 			err = ipv6_only_sock(sk) ?
1391 				-ENETUNREACH : udp_sendmsg(sk, msg, len);
1392 			msg->msg_name = sin6;
1393 			msg->msg_namelen = addr_len;
1394 			return err;
1395 		}
1396 	}
1397 
1398 	/* Rough check on arithmetic overflow,
1399 	   better check is made in ip6_append_data().
1400 	   */
1401 	if (len > INT_MAX - sizeof(struct udphdr))
1402 		return -EMSGSIZE;
1403 
1404 	getfrag  =  is_udplite ?  udplite_getfrag : ip_generic_getfrag;
1405 	if (READ_ONCE(up->pending)) {
1406 		if (READ_ONCE(up->pending) == AF_INET)
1407 			return udp_sendmsg(sk, msg, len);
1408 		/*
1409 		 * There are pending frames.
1410 		 * The socket lock must be held while it's corked.
1411 		 */
1412 		lock_sock(sk);
1413 		if (likely(up->pending)) {
1414 			if (unlikely(up->pending != AF_INET6)) {
1415 				release_sock(sk);
1416 				return -EAFNOSUPPORT;
1417 			}
1418 			dst = NULL;
1419 			goto do_append_data;
1420 		}
1421 		release_sock(sk);
1422 	}
1423 	ulen += sizeof(struct udphdr);
1424 
1425 	memset(fl6, 0, sizeof(*fl6));
1426 
1427 	if (sin6) {
1428 		if (sin6->sin6_port == 0)
1429 			return -EINVAL;
1430 
1431 		fl6->fl6_dport = sin6->sin6_port;
1432 		daddr = &sin6->sin6_addr;
1433 
1434 		if (np->sndflow) {
1435 			fl6->flowlabel = sin6->sin6_flowinfo&IPV6_FLOWINFO_MASK;
1436 			if (fl6->flowlabel & IPV6_FLOWLABEL_MASK) {
1437 				flowlabel = fl6_sock_lookup(sk, fl6->flowlabel);
1438 				if (IS_ERR(flowlabel))
1439 					return -EINVAL;
1440 			}
1441 		}
1442 
1443 		/*
1444 		 * Otherwise it will be difficult to maintain
1445 		 * sk->sk_dst_cache.
1446 		 */
1447 		if (sk->sk_state == TCP_ESTABLISHED &&
1448 		    ipv6_addr_equal(daddr, &sk->sk_v6_daddr))
1449 			daddr = &sk->sk_v6_daddr;
1450 
1451 		if (addr_len >= sizeof(struct sockaddr_in6) &&
1452 		    sin6->sin6_scope_id &&
1453 		    __ipv6_addr_needs_scope_id(__ipv6_addr_type(daddr)))
1454 			fl6->flowi6_oif = sin6->sin6_scope_id;
1455 	} else {
1456 		if (sk->sk_state != TCP_ESTABLISHED)
1457 			return -EDESTADDRREQ;
1458 
1459 		fl6->fl6_dport = inet->inet_dport;
1460 		daddr = &sk->sk_v6_daddr;
1461 		fl6->flowlabel = np->flow_label;
1462 		connected = true;
1463 	}
1464 
1465 	if (!fl6->flowi6_oif)
1466 		fl6->flowi6_oif = READ_ONCE(sk->sk_bound_dev_if);
1467 
1468 	if (!fl6->flowi6_oif)
1469 		fl6->flowi6_oif = np->sticky_pktinfo.ipi6_ifindex;
1470 
1471 	fl6->flowi6_uid = sk->sk_uid;
1472 
1473 	if (msg->msg_controllen) {
1474 		opt = &opt_space;
1475 		memset(opt, 0, sizeof(struct ipv6_txoptions));
1476 		opt->tot_len = sizeof(*opt);
1477 		ipc6.opt = opt;
1478 
1479 		err = udp_cmsg_send(sk, msg, &ipc6.gso_size);
1480 		if (err > 0) {
1481 			err = ip6_datagram_send_ctl(sock_net(sk), sk, msg, fl6,
1482 						    &ipc6);
1483 			connected = false;
1484 		}
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 	}
1497 	if (!opt) {
1498 		opt = txopt_get(np);
1499 		opt_to_free = opt;
1500 	}
1501 	if (flowlabel)
1502 		opt = fl6_merge_options(&opt_space, flowlabel, opt);
1503 	opt = ipv6_fixup_options(&opt_space, opt);
1504 	ipc6.opt = opt;
1505 
1506 	fl6->flowi6_proto = sk->sk_protocol;
1507 	fl6->flowi6_mark = ipc6.sockc.mark;
1508 	fl6->daddr = *daddr;
1509 	if (ipv6_addr_any(&fl6->saddr) && !ipv6_addr_any(&np->saddr))
1510 		fl6->saddr = np->saddr;
1511 	fl6->fl6_sport = inet->inet_sport;
1512 
1513 	if (cgroup_bpf_enabled(CGROUP_UDP6_SENDMSG) && !connected) {
1514 		err = BPF_CGROUP_RUN_PROG_UDP6_SENDMSG_LOCK(sk,
1515 					   (struct sockaddr *)sin6,
1516 					   &addr_len,
1517 					   &fl6->saddr);
1518 		if (err)
1519 			goto out_no_dst;
1520 		if (sin6) {
1521 			if (ipv6_addr_v4mapped(&sin6->sin6_addr)) {
1522 				/* BPF program rewrote IPv6-only by IPv4-mapped
1523 				 * IPv6. It's currently unsupported.
1524 				 */
1525 				err = -ENOTSUPP;
1526 				goto out_no_dst;
1527 			}
1528 			if (sin6->sin6_port == 0) {
1529 				/* BPF program set invalid port. Reject it. */
1530 				err = -EINVAL;
1531 				goto out_no_dst;
1532 			}
1533 			fl6->fl6_dport = sin6->sin6_port;
1534 			fl6->daddr = sin6->sin6_addr;
1535 		}
1536 	}
1537 
1538 	if (ipv6_addr_any(&fl6->daddr))
1539 		fl6->daddr.s6_addr[15] = 0x1; /* :: means loopback (BSD'ism) */
1540 
1541 	final_p = fl6_update_dst(fl6, opt, &final);
1542 	if (final_p)
1543 		connected = false;
1544 
1545 	if (!fl6->flowi6_oif && ipv6_addr_is_multicast(&fl6->daddr)) {
1546 		fl6->flowi6_oif = np->mcast_oif;
1547 		connected = false;
1548 	} else if (!fl6->flowi6_oif)
1549 		fl6->flowi6_oif = np->ucast_oif;
1550 
1551 	security_sk_classify_flow(sk, flowi6_to_flowi_common(fl6));
1552 
1553 	if (ipc6.tclass < 0)
1554 		ipc6.tclass = np->tclass;
1555 
1556 	fl6->flowlabel = ip6_make_flowinfo(ipc6.tclass, fl6->flowlabel);
1557 
1558 	dst = ip6_sk_dst_lookup_flow(sk, fl6, final_p, connected);
1559 	if (IS_ERR(dst)) {
1560 		err = PTR_ERR(dst);
1561 		dst = NULL;
1562 		goto out;
1563 	}
1564 
1565 	if (ipc6.hlimit < 0)
1566 		ipc6.hlimit = ip6_sk_dst_hoplimit(np, fl6, dst);
1567 
1568 	if (msg->msg_flags&MSG_CONFIRM)
1569 		goto do_confirm;
1570 back_from_confirm:
1571 
1572 	/* Lockless fast path for the non-corking case */
1573 	if (!corkreq) {
1574 		struct sk_buff *skb;
1575 
1576 		skb = ip6_make_skb(sk, getfrag, msg, ulen,
1577 				   sizeof(struct udphdr), &ipc6,
1578 				   (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 		/* ip6_make_skb steals dst reference */
1584 		goto out_no_dst;
1585 	}
1586 
1587 	lock_sock(sk);
1588 	if (unlikely(up->pending)) {
1589 		/* The socket is already corked while preparing it. */
1590 		/* ... which is an evident application bug. --ANK */
1591 		release_sock(sk);
1592 
1593 		net_dbg_ratelimited("udp cork app bug 2\n");
1594 		err = -EINVAL;
1595 		goto out;
1596 	}
1597 
1598 	WRITE_ONCE(up->pending, AF_INET6);
1599 
1600 do_append_data:
1601 	if (ipc6.dontfrag < 0)
1602 		ipc6.dontfrag = np->dontfrag;
1603 	up->len += ulen;
1604 	err = ip6_append_data(sk, getfrag, msg, ulen, sizeof(struct udphdr),
1605 			      &ipc6, fl6, (struct rt6_info *)dst,
1606 			      corkreq ? msg->msg_flags|MSG_MORE : msg->msg_flags);
1607 	if (err)
1608 		udp_v6_flush_pending_frames(sk);
1609 	else if (!corkreq)
1610 		err = udp_v6_push_pending_frames(sk);
1611 	else if (unlikely(skb_queue_empty(&sk->sk_write_queue)))
1612 		WRITE_ONCE(up->pending, 0);
1613 
1614 	if (err > 0)
1615 		err = np->recverr ? net_xmit_errno(err) : 0;
1616 	release_sock(sk);
1617 
1618 out:
1619 	dst_release(dst);
1620 out_no_dst:
1621 	fl6_sock_release(flowlabel);
1622 	txopt_put(opt_to_free);
1623 	if (!err)
1624 		return len;
1625 	/*
1626 	 * ENOBUFS = no kernel mem, SOCK_NOSPACE = no sndbuf space.  Reporting
1627 	 * ENOBUFS might not be good (it's not tunable per se), but otherwise
1628 	 * we don't have a good statistic (IpOutDiscards but it can be too many
1629 	 * things).  We could add another new stat but at least for now that
1630 	 * seems like overkill.
1631 	 */
1632 	if (err == -ENOBUFS || test_bit(SOCK_NOSPACE, &sk->sk_socket->flags)) {
1633 		UDP6_INC_STATS(sock_net(sk),
1634 			       UDP_MIB_SNDBUFERRORS, is_udplite);
1635 	}
1636 	return err;
1637 
1638 do_confirm:
1639 	if (msg->msg_flags & MSG_PROBE)
1640 		dst_confirm_neigh(dst, &fl6->daddr);
1641 	if (!(msg->msg_flags&MSG_PROBE) || len)
1642 		goto back_from_confirm;
1643 	err = 0;
1644 	goto out;
1645 }
1646 EXPORT_SYMBOL(udpv6_sendmsg);
1647 
udpv6_splice_eof(struct socket * sock)1648 static void udpv6_splice_eof(struct socket *sock)
1649 {
1650 	struct sock *sk = sock->sk;
1651 	struct udp_sock *up = udp_sk(sk);
1652 
1653 	if (!READ_ONCE(up->pending) || udp_test_bit(CORK, sk))
1654 		return;
1655 
1656 	lock_sock(sk);
1657 	if (up->pending && !udp_test_bit(CORK, sk))
1658 		udp_v6_push_pending_frames(sk);
1659 	release_sock(sk);
1660 }
1661 
udpv6_destroy_sock(struct sock * sk)1662 void udpv6_destroy_sock(struct sock *sk)
1663 {
1664 	struct udp_sock *up = udp_sk(sk);
1665 	lock_sock(sk);
1666 
1667 	/* protects from races with udp_abort() */
1668 	sock_set_flag(sk, SOCK_DEAD);
1669 	udp_v6_flush_pending_frames(sk);
1670 	release_sock(sk);
1671 
1672 	if (static_branch_unlikely(&udpv6_encap_needed_key)) {
1673 		if (up->encap_type) {
1674 			void (*encap_destroy)(struct sock *sk);
1675 			encap_destroy = READ_ONCE(up->encap_destroy);
1676 			if (encap_destroy)
1677 				encap_destroy(sk);
1678 		}
1679 		if (udp_test_bit(ENCAP_ENABLED, sk)) {
1680 			static_branch_dec(&udpv6_encap_needed_key);
1681 			udp_encap_disable();
1682 		}
1683 	}
1684 }
1685 
1686 /*
1687  *	Socket option code for UDP
1688  */
udpv6_setsockopt(struct sock * sk,int level,int optname,sockptr_t optval,unsigned int optlen)1689 int udpv6_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval,
1690 		     unsigned int optlen)
1691 {
1692 	if (level == SOL_UDP  ||  level == SOL_UDPLITE || level == SOL_SOCKET)
1693 		return udp_lib_setsockopt(sk, level, optname,
1694 					  optval, optlen,
1695 					  udp_v6_push_pending_frames);
1696 	return ipv6_setsockopt(sk, level, optname, optval, optlen);
1697 }
1698 
udpv6_getsockopt(struct sock * sk,int level,int optname,char __user * optval,int __user * optlen)1699 int udpv6_getsockopt(struct sock *sk, int level, int optname,
1700 		     char __user *optval, int __user *optlen)
1701 {
1702 	if (level == SOL_UDP  ||  level == SOL_UDPLITE)
1703 		return udp_lib_getsockopt(sk, level, optname, optval, optlen);
1704 	return ipv6_getsockopt(sk, level, optname, optval, optlen);
1705 }
1706 
1707 static const struct inet6_protocol udpv6_protocol = {
1708 	.handler	=	udpv6_rcv,
1709 	.err_handler	=	udpv6_err,
1710 	.flags		=	INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
1711 };
1712 
1713 /* ------------------------------------------------------------------------ */
1714 #ifdef CONFIG_PROC_FS
udp6_seq_show(struct seq_file * seq,void * v)1715 int udp6_seq_show(struct seq_file *seq, void *v)
1716 {
1717 	if (v == SEQ_START_TOKEN) {
1718 		seq_puts(seq, IPV6_SEQ_DGRAM_HEADER);
1719 	} else {
1720 		int bucket = ((struct udp_iter_state *)seq->private)->bucket;
1721 		const struct inet_sock *inet = inet_sk((const struct sock *)v);
1722 		__u16 srcp = ntohs(inet->inet_sport);
1723 		__u16 destp = ntohs(inet->inet_dport);
1724 		__ip6_dgram_sock_seq_show(seq, v, srcp, destp,
1725 					  udp_rqueue_get(v), bucket);
1726 	}
1727 	return 0;
1728 }
1729 
1730 const struct seq_operations udp6_seq_ops = {
1731 	.start		= udp_seq_start,
1732 	.next		= udp_seq_next,
1733 	.stop		= udp_seq_stop,
1734 	.show		= udp6_seq_show,
1735 };
1736 EXPORT_SYMBOL(udp6_seq_ops);
1737 
1738 static struct udp_seq_afinfo udp6_seq_afinfo = {
1739 	.family		= AF_INET6,
1740 	.udp_table	= NULL,
1741 };
1742 
udp6_proc_init(struct net * net)1743 int __net_init udp6_proc_init(struct net *net)
1744 {
1745 	if (!proc_create_net_data("udp6", 0444, net->proc_net, &udp6_seq_ops,
1746 			sizeof(struct udp_iter_state), &udp6_seq_afinfo))
1747 		return -ENOMEM;
1748 	return 0;
1749 }
1750 
udp6_proc_exit(struct net * net)1751 void udp6_proc_exit(struct net *net)
1752 {
1753 	remove_proc_entry("udp6", net->proc_net);
1754 }
1755 #endif /* CONFIG_PROC_FS */
1756 
1757 /* ------------------------------------------------------------------------ */
1758 
1759 struct proto udpv6_prot = {
1760 	.name			= "UDPv6",
1761 	.owner			= THIS_MODULE,
1762 	.close			= udp_lib_close,
1763 	.pre_connect		= udpv6_pre_connect,
1764 	.connect		= ip6_datagram_connect,
1765 	.disconnect		= udp_disconnect,
1766 	.ioctl			= udp_ioctl,
1767 	.init			= udpv6_init_sock,
1768 	.destroy		= udpv6_destroy_sock,
1769 	.setsockopt		= udpv6_setsockopt,
1770 	.getsockopt		= udpv6_getsockopt,
1771 	.sendmsg		= udpv6_sendmsg,
1772 	.recvmsg		= udpv6_recvmsg,
1773 	.splice_eof		= udpv6_splice_eof,
1774 	.release_cb		= ip6_datagram_release_cb,
1775 	.hash			= udp_lib_hash,
1776 	.unhash			= udp_lib_unhash,
1777 	.rehash			= udp_v6_rehash,
1778 	.get_port		= udp_v6_get_port,
1779 	.put_port		= udp_lib_unhash,
1780 #ifdef CONFIG_BPF_SYSCALL
1781 	.psock_update_sk_prot	= udp_bpf_update_proto,
1782 #endif
1783 
1784 	.memory_allocated	= &udp_memory_allocated,
1785 	.per_cpu_fw_alloc	= &udp_memory_per_cpu_fw_alloc,
1786 
1787 	.sysctl_mem		= sysctl_udp_mem,
1788 	.sysctl_wmem_offset     = offsetof(struct net, ipv4.sysctl_udp_wmem_min),
1789 	.sysctl_rmem_offset     = offsetof(struct net, ipv4.sysctl_udp_rmem_min),
1790 	.obj_size		= sizeof(struct udp6_sock),
1791 	.ipv6_pinfo_offset = offsetof(struct udp6_sock, inet6),
1792 	.h.udp_table		= NULL,
1793 	.diag_destroy		= udp_abort,
1794 };
1795 
1796 static struct inet_protosw udpv6_protosw = {
1797 	.type =      SOCK_DGRAM,
1798 	.protocol =  IPPROTO_UDP,
1799 	.prot =      &udpv6_prot,
1800 	.ops =       &inet6_dgram_ops,
1801 	.flags =     INET_PROTOSW_PERMANENT,
1802 };
1803 
udpv6_init(void)1804 int __init udpv6_init(void)
1805 {
1806 	int ret;
1807 
1808 	ret = inet6_add_protocol(&udpv6_protocol, IPPROTO_UDP);
1809 	if (ret)
1810 		goto out;
1811 
1812 	ret = inet6_register_protosw(&udpv6_protosw);
1813 	if (ret)
1814 		goto out_udpv6_protocol;
1815 out:
1816 	return ret;
1817 
1818 out_udpv6_protocol:
1819 	inet6_del_protocol(&udpv6_protocol, IPPROTO_UDP);
1820 	goto out;
1821 }
1822 
udpv6_exit(void)1823 void udpv6_exit(void)
1824 {
1825 	inet6_unregister_protosw(&udpv6_protosw);
1826 	inet6_del_protocol(&udpv6_protocol, IPPROTO_UDP);
1827 }
1828