xref: /linux/net/core/sock.c (revision 05ee19c18c2bb3dea69e29219017367c4a77e65a)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * INET		An implementation of the TCP/IP protocol suite for the LINUX
4  *		operating system.  INET is implemented using the  BSD Socket
5  *		interface as the means of communication with the user level.
6  *
7  *		Generic socket support routines. Memory allocators, socket lock/release
8  *		handler for protocols to use and generic option handler.
9  *
10  * Authors:	Ross Biro
11  *		Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
12  *		Florian La Roche, <flla@stud.uni-sb.de>
13  *		Alan Cox, <A.Cox@swansea.ac.uk>
14  *
15  * Fixes:
16  *		Alan Cox	: 	Numerous verify_area() problems
17  *		Alan Cox	:	Connecting on a connecting socket
18  *					now returns an error for tcp.
19  *		Alan Cox	:	sock->protocol is set correctly.
20  *					and is not sometimes left as 0.
21  *		Alan Cox	:	connect handles icmp errors on a
22  *					connect properly. Unfortunately there
23  *					is a restart syscall nasty there. I
24  *					can't match BSD without hacking the C
25  *					library. Ideas urgently sought!
26  *		Alan Cox	:	Disallow bind() to addresses that are
27  *					not ours - especially broadcast ones!!
28  *		Alan Cox	:	Socket 1024 _IS_ ok for users. (fencepost)
29  *		Alan Cox	:	sock_wfree/sock_rfree don't destroy sockets,
30  *					instead they leave that for the DESTROY timer.
31  *		Alan Cox	:	Clean up error flag in accept
32  *		Alan Cox	:	TCP ack handling is buggy, the DESTROY timer
33  *					was buggy. Put a remove_sock() in the handler
34  *					for memory when we hit 0. Also altered the timer
35  *					code. The ACK stuff can wait and needs major
36  *					TCP layer surgery.
37  *		Alan Cox	:	Fixed TCP ack bug, removed remove sock
38  *					and fixed timer/inet_bh race.
39  *		Alan Cox	:	Added zapped flag for TCP
40  *		Alan Cox	:	Move kfree_skb into skbuff.c and tidied up surplus code
41  *		Alan Cox	:	for new sk_buff allocations wmalloc/rmalloc now call alloc_skb
42  *		Alan Cox	:	kfree_s calls now are kfree_skbmem so we can track skb resources
43  *		Alan Cox	:	Supports socket option broadcast now as does udp. Packet and raw need fixing.
44  *		Alan Cox	:	Added RCVBUF,SNDBUF size setting. It suddenly occurred to me how easy it was so...
45  *		Rick Sladkey	:	Relaxed UDP rules for matching packets.
46  *		C.E.Hawkins	:	IFF_PROMISC/SIOCGHWADDR support
47  *	Pauline Middelink	:	identd support
48  *		Alan Cox	:	Fixed connect() taking signals I think.
49  *		Alan Cox	:	SO_LINGER supported
50  *		Alan Cox	:	Error reporting fixes
51  *		Anonymous	:	inet_create tidied up (sk->reuse setting)
52  *		Alan Cox	:	inet sockets don't set sk->type!
53  *		Alan Cox	:	Split socket option code
54  *		Alan Cox	:	Callbacks
55  *		Alan Cox	:	Nagle flag for Charles & Johannes stuff
56  *		Alex		:	Removed restriction on inet fioctl
57  *		Alan Cox	:	Splitting INET from NET core
58  *		Alan Cox	:	Fixed bogus SO_TYPE handling in getsockopt()
59  *		Adam Caldwell	:	Missing return in SO_DONTROUTE/SO_DEBUG code
60  *		Alan Cox	:	Split IP from generic code
61  *		Alan Cox	:	New kfree_skbmem()
62  *		Alan Cox	:	Make SO_DEBUG superuser only.
63  *		Alan Cox	:	Allow anyone to clear SO_DEBUG
64  *					(compatibility fix)
65  *		Alan Cox	:	Added optimistic memory grabbing for AF_UNIX throughput.
66  *		Alan Cox	:	Allocator for a socket is settable.
67  *		Alan Cox	:	SO_ERROR includes soft errors.
68  *		Alan Cox	:	Allow NULL arguments on some SO_ opts
69  *		Alan Cox	: 	Generic socket allocation to make hooks
70  *					easier (suggested by Craig Metz).
71  *		Michael Pall	:	SO_ERROR returns positive errno again
72  *              Steve Whitehouse:       Added default destructor to free
73  *                                      protocol private data.
74  *              Steve Whitehouse:       Added various other default routines
75  *                                      common to several socket families.
76  *              Chris Evans     :       Call suser() check last on F_SETOWN
77  *		Jay Schulist	:	Added SO_ATTACH_FILTER and SO_DETACH_FILTER.
78  *		Andi Kleen	:	Add sock_kmalloc()/sock_kfree_s()
79  *		Andi Kleen	:	Fix write_space callback
80  *		Chris Evans	:	Security fixes - signedness again
81  *		Arnaldo C. Melo :       cleanups, use skb_queue_purge
82  *
83  * To Fix:
84  */
85 
86 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
87 
88 #include <asm/unaligned.h>
89 #include <linux/capability.h>
90 #include <linux/errno.h>
91 #include <linux/errqueue.h>
92 #include <linux/types.h>
93 #include <linux/socket.h>
94 #include <linux/in.h>
95 #include <linux/kernel.h>
96 #include <linux/module.h>
97 #include <linux/proc_fs.h>
98 #include <linux/seq_file.h>
99 #include <linux/sched.h>
100 #include <linux/sched/mm.h>
101 #include <linux/timer.h>
102 #include <linux/string.h>
103 #include <linux/sockios.h>
104 #include <linux/net.h>
105 #include <linux/mm.h>
106 #include <linux/slab.h>
107 #include <linux/interrupt.h>
108 #include <linux/poll.h>
109 #include <linux/tcp.h>
110 #include <linux/init.h>
111 #include <linux/highmem.h>
112 #include <linux/user_namespace.h>
113 #include <linux/static_key.h>
114 #include <linux/memcontrol.h>
115 #include <linux/prefetch.h>
116 
117 #include <linux/uaccess.h>
118 
119 #include <linux/netdevice.h>
120 #include <net/protocol.h>
121 #include <linux/skbuff.h>
122 #include <net/net_namespace.h>
123 #include <net/request_sock.h>
124 #include <net/sock.h>
125 #include <linux/net_tstamp.h>
126 #include <net/xfrm.h>
127 #include <linux/ipsec.h>
128 #include <net/cls_cgroup.h>
129 #include <net/netprio_cgroup.h>
130 #include <linux/sock_diag.h>
131 
132 #include <linux/filter.h>
133 #include <net/sock_reuseport.h>
134 #include <net/bpf_sk_storage.h>
135 
136 #include <trace/events/sock.h>
137 
138 #include <net/tcp.h>
139 #include <net/busy_poll.h>
140 
141 static DEFINE_MUTEX(proto_list_mutex);
142 static LIST_HEAD(proto_list);
143 
144 static void sock_inuse_add(struct net *net, int val);
145 
146 /**
147  * sk_ns_capable - General socket capability test
148  * @sk: Socket to use a capability on or through
149  * @user_ns: The user namespace of the capability to use
150  * @cap: The capability to use
151  *
152  * Test to see if the opener of the socket had when the socket was
153  * created and the current process has the capability @cap in the user
154  * namespace @user_ns.
155  */
156 bool sk_ns_capable(const struct sock *sk,
157 		   struct user_namespace *user_ns, int cap)
158 {
159 	return file_ns_capable(sk->sk_socket->file, user_ns, cap) &&
160 		ns_capable(user_ns, cap);
161 }
162 EXPORT_SYMBOL(sk_ns_capable);
163 
164 /**
165  * sk_capable - Socket global capability test
166  * @sk: Socket to use a capability on or through
167  * @cap: The global capability to use
168  *
169  * Test to see if the opener of the socket had when the socket was
170  * created and the current process has the capability @cap in all user
171  * namespaces.
172  */
173 bool sk_capable(const struct sock *sk, int cap)
174 {
175 	return sk_ns_capable(sk, &init_user_ns, cap);
176 }
177 EXPORT_SYMBOL(sk_capable);
178 
179 /**
180  * sk_net_capable - Network namespace socket capability test
181  * @sk: Socket to use a capability on or through
182  * @cap: The capability to use
183  *
184  * Test to see if the opener of the socket had when the socket was created
185  * and the current process has the capability @cap over the network namespace
186  * the socket is a member of.
187  */
188 bool sk_net_capable(const struct sock *sk, int cap)
189 {
190 	return sk_ns_capable(sk, sock_net(sk)->user_ns, cap);
191 }
192 EXPORT_SYMBOL(sk_net_capable);
193 
194 /*
195  * Each address family might have different locking rules, so we have
196  * one slock key per address family and separate keys for internal and
197  * userspace sockets.
198  */
199 static struct lock_class_key af_family_keys[AF_MAX];
200 static struct lock_class_key af_family_kern_keys[AF_MAX];
201 static struct lock_class_key af_family_slock_keys[AF_MAX];
202 static struct lock_class_key af_family_kern_slock_keys[AF_MAX];
203 
204 /*
205  * Make lock validator output more readable. (we pre-construct these
206  * strings build-time, so that runtime initialization of socket
207  * locks is fast):
208  */
209 
210 #define _sock_locks(x)						  \
211   x "AF_UNSPEC",	x "AF_UNIX"     ,	x "AF_INET"     , \
212   x "AF_AX25"  ,	x "AF_IPX"      ,	x "AF_APPLETALK", \
213   x "AF_NETROM",	x "AF_BRIDGE"   ,	x "AF_ATMPVC"   , \
214   x "AF_X25"   ,	x "AF_INET6"    ,	x "AF_ROSE"     , \
215   x "AF_DECnet",	x "AF_NETBEUI"  ,	x "AF_SECURITY" , \
216   x "AF_KEY"   ,	x "AF_NETLINK"  ,	x "AF_PACKET"   , \
217   x "AF_ASH"   ,	x "AF_ECONET"   ,	x "AF_ATMSVC"   , \
218   x "AF_RDS"   ,	x "AF_SNA"      ,	x "AF_IRDA"     , \
219   x "AF_PPPOX" ,	x "AF_WANPIPE"  ,	x "AF_LLC"      , \
220   x "27"       ,	x "28"          ,	x "AF_CAN"      , \
221   x "AF_TIPC"  ,	x "AF_BLUETOOTH",	x "IUCV"        , \
222   x "AF_RXRPC" ,	x "AF_ISDN"     ,	x "AF_PHONET"   , \
223   x "AF_IEEE802154",	x "AF_CAIF"	,	x "AF_ALG"      , \
224   x "AF_NFC"   ,	x "AF_VSOCK"    ,	x "AF_KCM"      , \
225   x "AF_QIPCRTR",	x "AF_SMC"	,	x "AF_XDP"	, \
226   x "AF_MAX"
227 
228 static const char *const af_family_key_strings[AF_MAX+1] = {
229 	_sock_locks("sk_lock-")
230 };
231 static const char *const af_family_slock_key_strings[AF_MAX+1] = {
232 	_sock_locks("slock-")
233 };
234 static const char *const af_family_clock_key_strings[AF_MAX+1] = {
235 	_sock_locks("clock-")
236 };
237 
238 static const char *const af_family_kern_key_strings[AF_MAX+1] = {
239 	_sock_locks("k-sk_lock-")
240 };
241 static const char *const af_family_kern_slock_key_strings[AF_MAX+1] = {
242 	_sock_locks("k-slock-")
243 };
244 static const char *const af_family_kern_clock_key_strings[AF_MAX+1] = {
245 	_sock_locks("k-clock-")
246 };
247 static const char *const af_family_rlock_key_strings[AF_MAX+1] = {
248 	_sock_locks("rlock-")
249 };
250 static const char *const af_family_wlock_key_strings[AF_MAX+1] = {
251 	_sock_locks("wlock-")
252 };
253 static const char *const af_family_elock_key_strings[AF_MAX+1] = {
254 	_sock_locks("elock-")
255 };
256 
257 /*
258  * sk_callback_lock and sk queues locking rules are per-address-family,
259  * so split the lock classes by using a per-AF key:
260  */
261 static struct lock_class_key af_callback_keys[AF_MAX];
262 static struct lock_class_key af_rlock_keys[AF_MAX];
263 static struct lock_class_key af_wlock_keys[AF_MAX];
264 static struct lock_class_key af_elock_keys[AF_MAX];
265 static struct lock_class_key af_kern_callback_keys[AF_MAX];
266 
267 /* Run time adjustable parameters. */
268 __u32 sysctl_wmem_max __read_mostly = SK_WMEM_MAX;
269 EXPORT_SYMBOL(sysctl_wmem_max);
270 __u32 sysctl_rmem_max __read_mostly = SK_RMEM_MAX;
271 EXPORT_SYMBOL(sysctl_rmem_max);
272 __u32 sysctl_wmem_default __read_mostly = SK_WMEM_MAX;
273 __u32 sysctl_rmem_default __read_mostly = SK_RMEM_MAX;
274 
275 /* Maximal space eaten by iovec or ancillary data plus some space */
276 int sysctl_optmem_max __read_mostly = sizeof(unsigned long)*(2*UIO_MAXIOV+512);
277 EXPORT_SYMBOL(sysctl_optmem_max);
278 
279 int sysctl_tstamp_allow_data __read_mostly = 1;
280 
281 DEFINE_STATIC_KEY_FALSE(memalloc_socks_key);
282 EXPORT_SYMBOL_GPL(memalloc_socks_key);
283 
284 /**
285  * sk_set_memalloc - sets %SOCK_MEMALLOC
286  * @sk: socket to set it on
287  *
288  * Set %SOCK_MEMALLOC on a socket for access to emergency reserves.
289  * It's the responsibility of the admin to adjust min_free_kbytes
290  * to meet the requirements
291  */
292 void sk_set_memalloc(struct sock *sk)
293 {
294 	sock_set_flag(sk, SOCK_MEMALLOC);
295 	sk->sk_allocation |= __GFP_MEMALLOC;
296 	static_branch_inc(&memalloc_socks_key);
297 }
298 EXPORT_SYMBOL_GPL(sk_set_memalloc);
299 
300 void sk_clear_memalloc(struct sock *sk)
301 {
302 	sock_reset_flag(sk, SOCK_MEMALLOC);
303 	sk->sk_allocation &= ~__GFP_MEMALLOC;
304 	static_branch_dec(&memalloc_socks_key);
305 
306 	/*
307 	 * SOCK_MEMALLOC is allowed to ignore rmem limits to ensure forward
308 	 * progress of swapping. SOCK_MEMALLOC may be cleared while
309 	 * it has rmem allocations due to the last swapfile being deactivated
310 	 * but there is a risk that the socket is unusable due to exceeding
311 	 * the rmem limits. Reclaim the reserves and obey rmem limits again.
312 	 */
313 	sk_mem_reclaim(sk);
314 }
315 EXPORT_SYMBOL_GPL(sk_clear_memalloc);
316 
317 int __sk_backlog_rcv(struct sock *sk, struct sk_buff *skb)
318 {
319 	int ret;
320 	unsigned int noreclaim_flag;
321 
322 	/* these should have been dropped before queueing */
323 	BUG_ON(!sock_flag(sk, SOCK_MEMALLOC));
324 
325 	noreclaim_flag = memalloc_noreclaim_save();
326 	ret = sk->sk_backlog_rcv(sk, skb);
327 	memalloc_noreclaim_restore(noreclaim_flag);
328 
329 	return ret;
330 }
331 EXPORT_SYMBOL(__sk_backlog_rcv);
332 
333 static int sock_get_timeout(long timeo, void *optval, bool old_timeval)
334 {
335 	struct __kernel_sock_timeval tv;
336 
337 	if (timeo == MAX_SCHEDULE_TIMEOUT) {
338 		tv.tv_sec = 0;
339 		tv.tv_usec = 0;
340 	} else {
341 		tv.tv_sec = timeo / HZ;
342 		tv.tv_usec = ((timeo % HZ) * USEC_PER_SEC) / HZ;
343 	}
344 
345 	if (old_timeval && in_compat_syscall() && !COMPAT_USE_64BIT_TIME) {
346 		struct old_timeval32 tv32 = { tv.tv_sec, tv.tv_usec };
347 		*(struct old_timeval32 *)optval = tv32;
348 		return sizeof(tv32);
349 	}
350 
351 	if (old_timeval) {
352 		struct __kernel_old_timeval old_tv;
353 		old_tv.tv_sec = tv.tv_sec;
354 		old_tv.tv_usec = tv.tv_usec;
355 		*(struct __kernel_old_timeval *)optval = old_tv;
356 		return sizeof(old_tv);
357 	}
358 
359 	*(struct __kernel_sock_timeval *)optval = tv;
360 	return sizeof(tv);
361 }
362 
363 static int sock_set_timeout(long *timeo_p, char __user *optval, int optlen, bool old_timeval)
364 {
365 	struct __kernel_sock_timeval tv;
366 
367 	if (old_timeval && in_compat_syscall() && !COMPAT_USE_64BIT_TIME) {
368 		struct old_timeval32 tv32;
369 
370 		if (optlen < sizeof(tv32))
371 			return -EINVAL;
372 
373 		if (copy_from_user(&tv32, optval, sizeof(tv32)))
374 			return -EFAULT;
375 		tv.tv_sec = tv32.tv_sec;
376 		tv.tv_usec = tv32.tv_usec;
377 	} else if (old_timeval) {
378 		struct __kernel_old_timeval old_tv;
379 
380 		if (optlen < sizeof(old_tv))
381 			return -EINVAL;
382 		if (copy_from_user(&old_tv, optval, sizeof(old_tv)))
383 			return -EFAULT;
384 		tv.tv_sec = old_tv.tv_sec;
385 		tv.tv_usec = old_tv.tv_usec;
386 	} else {
387 		if (optlen < sizeof(tv))
388 			return -EINVAL;
389 		if (copy_from_user(&tv, optval, sizeof(tv)))
390 			return -EFAULT;
391 	}
392 	if (tv.tv_usec < 0 || tv.tv_usec >= USEC_PER_SEC)
393 		return -EDOM;
394 
395 	if (tv.tv_sec < 0) {
396 		static int warned __read_mostly;
397 
398 		*timeo_p = 0;
399 		if (warned < 10 && net_ratelimit()) {
400 			warned++;
401 			pr_info("%s: `%s' (pid %d) tries to set negative timeout\n",
402 				__func__, current->comm, task_pid_nr(current));
403 		}
404 		return 0;
405 	}
406 	*timeo_p = MAX_SCHEDULE_TIMEOUT;
407 	if (tv.tv_sec == 0 && tv.tv_usec == 0)
408 		return 0;
409 	if (tv.tv_sec < (MAX_SCHEDULE_TIMEOUT / HZ - 1))
410 		*timeo_p = tv.tv_sec * HZ + DIV_ROUND_UP((unsigned long)tv.tv_usec, USEC_PER_SEC / HZ);
411 	return 0;
412 }
413 
414 static void sock_warn_obsolete_bsdism(const char *name)
415 {
416 	static int warned;
417 	static char warncomm[TASK_COMM_LEN];
418 	if (strcmp(warncomm, current->comm) && warned < 5) {
419 		strcpy(warncomm,  current->comm);
420 		pr_warn("process `%s' is using obsolete %s SO_BSDCOMPAT\n",
421 			warncomm, name);
422 		warned++;
423 	}
424 }
425 
426 static bool sock_needs_netstamp(const struct sock *sk)
427 {
428 	switch (sk->sk_family) {
429 	case AF_UNSPEC:
430 	case AF_UNIX:
431 		return false;
432 	default:
433 		return true;
434 	}
435 }
436 
437 static void sock_disable_timestamp(struct sock *sk, unsigned long flags)
438 {
439 	if (sk->sk_flags & flags) {
440 		sk->sk_flags &= ~flags;
441 		if (sock_needs_netstamp(sk) &&
442 		    !(sk->sk_flags & SK_FLAGS_TIMESTAMP))
443 			net_disable_timestamp();
444 	}
445 }
446 
447 
448 int __sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
449 {
450 	unsigned long flags;
451 	struct sk_buff_head *list = &sk->sk_receive_queue;
452 
453 	if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf) {
454 		atomic_inc(&sk->sk_drops);
455 		trace_sock_rcvqueue_full(sk, skb);
456 		return -ENOMEM;
457 	}
458 
459 	if (!sk_rmem_schedule(sk, skb, skb->truesize)) {
460 		atomic_inc(&sk->sk_drops);
461 		return -ENOBUFS;
462 	}
463 
464 	skb->dev = NULL;
465 	skb_set_owner_r(skb, sk);
466 
467 	/* we escape from rcu protected region, make sure we dont leak
468 	 * a norefcounted dst
469 	 */
470 	skb_dst_force(skb);
471 
472 	spin_lock_irqsave(&list->lock, flags);
473 	sock_skb_set_dropcount(sk, skb);
474 	__skb_queue_tail(list, skb);
475 	spin_unlock_irqrestore(&list->lock, flags);
476 
477 	if (!sock_flag(sk, SOCK_DEAD))
478 		sk->sk_data_ready(sk);
479 	return 0;
480 }
481 EXPORT_SYMBOL(__sock_queue_rcv_skb);
482 
483 int sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
484 {
485 	int err;
486 
487 	err = sk_filter(sk, skb);
488 	if (err)
489 		return err;
490 
491 	return __sock_queue_rcv_skb(sk, skb);
492 }
493 EXPORT_SYMBOL(sock_queue_rcv_skb);
494 
495 int __sk_receive_skb(struct sock *sk, struct sk_buff *skb,
496 		     const int nested, unsigned int trim_cap, bool refcounted)
497 {
498 	int rc = NET_RX_SUCCESS;
499 
500 	if (sk_filter_trim_cap(sk, skb, trim_cap))
501 		goto discard_and_relse;
502 
503 	skb->dev = NULL;
504 
505 	if (sk_rcvqueues_full(sk, sk->sk_rcvbuf)) {
506 		atomic_inc(&sk->sk_drops);
507 		goto discard_and_relse;
508 	}
509 	if (nested)
510 		bh_lock_sock_nested(sk);
511 	else
512 		bh_lock_sock(sk);
513 	if (!sock_owned_by_user(sk)) {
514 		/*
515 		 * trylock + unlock semantics:
516 		 */
517 		mutex_acquire(&sk->sk_lock.dep_map, 0, 1, _RET_IP_);
518 
519 		rc = sk_backlog_rcv(sk, skb);
520 
521 		mutex_release(&sk->sk_lock.dep_map, _RET_IP_);
522 	} else if (sk_add_backlog(sk, skb, READ_ONCE(sk->sk_rcvbuf))) {
523 		bh_unlock_sock(sk);
524 		atomic_inc(&sk->sk_drops);
525 		goto discard_and_relse;
526 	}
527 
528 	bh_unlock_sock(sk);
529 out:
530 	if (refcounted)
531 		sock_put(sk);
532 	return rc;
533 discard_and_relse:
534 	kfree_skb(skb);
535 	goto out;
536 }
537 EXPORT_SYMBOL(__sk_receive_skb);
538 
539 struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie)
540 {
541 	struct dst_entry *dst = __sk_dst_get(sk);
542 
543 	if (dst && dst->obsolete && dst->ops->check(dst, cookie) == NULL) {
544 		sk_tx_queue_clear(sk);
545 		sk->sk_dst_pending_confirm = 0;
546 		RCU_INIT_POINTER(sk->sk_dst_cache, NULL);
547 		dst_release(dst);
548 		return NULL;
549 	}
550 
551 	return dst;
552 }
553 EXPORT_SYMBOL(__sk_dst_check);
554 
555 struct dst_entry *sk_dst_check(struct sock *sk, u32 cookie)
556 {
557 	struct dst_entry *dst = sk_dst_get(sk);
558 
559 	if (dst && dst->obsolete && dst->ops->check(dst, cookie) == NULL) {
560 		sk_dst_reset(sk);
561 		dst_release(dst);
562 		return NULL;
563 	}
564 
565 	return dst;
566 }
567 EXPORT_SYMBOL(sk_dst_check);
568 
569 static int sock_setbindtodevice_locked(struct sock *sk, int ifindex)
570 {
571 	int ret = -ENOPROTOOPT;
572 #ifdef CONFIG_NETDEVICES
573 	struct net *net = sock_net(sk);
574 
575 	/* Sorry... */
576 	ret = -EPERM;
577 	if (sk->sk_bound_dev_if && !ns_capable(net->user_ns, CAP_NET_RAW))
578 		goto out;
579 
580 	ret = -EINVAL;
581 	if (ifindex < 0)
582 		goto out;
583 
584 	sk->sk_bound_dev_if = ifindex;
585 	if (sk->sk_prot->rehash)
586 		sk->sk_prot->rehash(sk);
587 	sk_dst_reset(sk);
588 
589 	ret = 0;
590 
591 out:
592 #endif
593 
594 	return ret;
595 }
596 
597 static int sock_setbindtodevice(struct sock *sk, char __user *optval,
598 				int optlen)
599 {
600 	int ret = -ENOPROTOOPT;
601 #ifdef CONFIG_NETDEVICES
602 	struct net *net = sock_net(sk);
603 	char devname[IFNAMSIZ];
604 	int index;
605 
606 	ret = -EINVAL;
607 	if (optlen < 0)
608 		goto out;
609 
610 	/* Bind this socket to a particular device like "eth0",
611 	 * as specified in the passed interface name. If the
612 	 * name is "" or the option length is zero the socket
613 	 * is not bound.
614 	 */
615 	if (optlen > IFNAMSIZ - 1)
616 		optlen = IFNAMSIZ - 1;
617 	memset(devname, 0, sizeof(devname));
618 
619 	ret = -EFAULT;
620 	if (copy_from_user(devname, optval, optlen))
621 		goto out;
622 
623 	index = 0;
624 	if (devname[0] != '\0') {
625 		struct net_device *dev;
626 
627 		rcu_read_lock();
628 		dev = dev_get_by_name_rcu(net, devname);
629 		if (dev)
630 			index = dev->ifindex;
631 		rcu_read_unlock();
632 		ret = -ENODEV;
633 		if (!dev)
634 			goto out;
635 	}
636 
637 	lock_sock(sk);
638 	ret = sock_setbindtodevice_locked(sk, index);
639 	release_sock(sk);
640 
641 out:
642 #endif
643 
644 	return ret;
645 }
646 
647 static int sock_getbindtodevice(struct sock *sk, char __user *optval,
648 				int __user *optlen, int len)
649 {
650 	int ret = -ENOPROTOOPT;
651 #ifdef CONFIG_NETDEVICES
652 	struct net *net = sock_net(sk);
653 	char devname[IFNAMSIZ];
654 
655 	if (sk->sk_bound_dev_if == 0) {
656 		len = 0;
657 		goto zero;
658 	}
659 
660 	ret = -EINVAL;
661 	if (len < IFNAMSIZ)
662 		goto out;
663 
664 	ret = netdev_get_name(net, devname, sk->sk_bound_dev_if);
665 	if (ret)
666 		goto out;
667 
668 	len = strlen(devname) + 1;
669 
670 	ret = -EFAULT;
671 	if (copy_to_user(optval, devname, len))
672 		goto out;
673 
674 zero:
675 	ret = -EFAULT;
676 	if (put_user(len, optlen))
677 		goto out;
678 
679 	ret = 0;
680 
681 out:
682 #endif
683 
684 	return ret;
685 }
686 
687 static inline void sock_valbool_flag(struct sock *sk, enum sock_flags bit,
688 				     int valbool)
689 {
690 	if (valbool)
691 		sock_set_flag(sk, bit);
692 	else
693 		sock_reset_flag(sk, bit);
694 }
695 
696 bool sk_mc_loop(struct sock *sk)
697 {
698 	if (dev_recursion_level())
699 		return false;
700 	if (!sk)
701 		return true;
702 	switch (sk->sk_family) {
703 	case AF_INET:
704 		return inet_sk(sk)->mc_loop;
705 #if IS_ENABLED(CONFIG_IPV6)
706 	case AF_INET6:
707 		return inet6_sk(sk)->mc_loop;
708 #endif
709 	}
710 	WARN_ON(1);
711 	return true;
712 }
713 EXPORT_SYMBOL(sk_mc_loop);
714 
715 /*
716  *	This is meant for all protocols to use and covers goings on
717  *	at the socket level. Everything here is generic.
718  */
719 
720 int sock_setsockopt(struct socket *sock, int level, int optname,
721 		    char __user *optval, unsigned int optlen)
722 {
723 	struct sock_txtime sk_txtime;
724 	struct sock *sk = sock->sk;
725 	int val;
726 	int valbool;
727 	struct linger ling;
728 	int ret = 0;
729 
730 	/*
731 	 *	Options without arguments
732 	 */
733 
734 	if (optname == SO_BINDTODEVICE)
735 		return sock_setbindtodevice(sk, optval, optlen);
736 
737 	if (optlen < sizeof(int))
738 		return -EINVAL;
739 
740 	if (get_user(val, (int __user *)optval))
741 		return -EFAULT;
742 
743 	valbool = val ? 1 : 0;
744 
745 	lock_sock(sk);
746 
747 	switch (optname) {
748 	case SO_DEBUG:
749 		if (val && !capable(CAP_NET_ADMIN))
750 			ret = -EACCES;
751 		else
752 			sock_valbool_flag(sk, SOCK_DBG, valbool);
753 		break;
754 	case SO_REUSEADDR:
755 		sk->sk_reuse = (valbool ? SK_CAN_REUSE : SK_NO_REUSE);
756 		break;
757 	case SO_REUSEPORT:
758 		sk->sk_reuseport = valbool;
759 		break;
760 	case SO_TYPE:
761 	case SO_PROTOCOL:
762 	case SO_DOMAIN:
763 	case SO_ERROR:
764 		ret = -ENOPROTOOPT;
765 		break;
766 	case SO_DONTROUTE:
767 		sock_valbool_flag(sk, SOCK_LOCALROUTE, valbool);
768 		sk_dst_reset(sk);
769 		break;
770 	case SO_BROADCAST:
771 		sock_valbool_flag(sk, SOCK_BROADCAST, valbool);
772 		break;
773 	case SO_SNDBUF:
774 		/* Don't error on this BSD doesn't and if you think
775 		 * about it this is right. Otherwise apps have to
776 		 * play 'guess the biggest size' games. RCVBUF/SNDBUF
777 		 * are treated in BSD as hints
778 		 */
779 		val = min_t(u32, val, sysctl_wmem_max);
780 set_sndbuf:
781 		/* Ensure val * 2 fits into an int, to prevent max_t()
782 		 * from treating it as a negative value.
783 		 */
784 		val = min_t(int, val, INT_MAX / 2);
785 		sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
786 		WRITE_ONCE(sk->sk_sndbuf,
787 			   max_t(int, val * 2, SOCK_MIN_SNDBUF));
788 		/* Wake up sending tasks if we upped the value. */
789 		sk->sk_write_space(sk);
790 		break;
791 
792 	case SO_SNDBUFFORCE:
793 		if (!capable(CAP_NET_ADMIN)) {
794 			ret = -EPERM;
795 			break;
796 		}
797 
798 		/* No negative values (to prevent underflow, as val will be
799 		 * multiplied by 2).
800 		 */
801 		if (val < 0)
802 			val = 0;
803 		goto set_sndbuf;
804 
805 	case SO_RCVBUF:
806 		/* Don't error on this BSD doesn't and if you think
807 		 * about it this is right. Otherwise apps have to
808 		 * play 'guess the biggest size' games. RCVBUF/SNDBUF
809 		 * are treated in BSD as hints
810 		 */
811 		val = min_t(u32, val, sysctl_rmem_max);
812 set_rcvbuf:
813 		/* Ensure val * 2 fits into an int, to prevent max_t()
814 		 * from treating it as a negative value.
815 		 */
816 		val = min_t(int, val, INT_MAX / 2);
817 		sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
818 		/*
819 		 * We double it on the way in to account for
820 		 * "struct sk_buff" etc. overhead.   Applications
821 		 * assume that the SO_RCVBUF setting they make will
822 		 * allow that much actual data to be received on that
823 		 * socket.
824 		 *
825 		 * Applications are unaware that "struct sk_buff" and
826 		 * other overheads allocate from the receive buffer
827 		 * during socket buffer allocation.
828 		 *
829 		 * And after considering the possible alternatives,
830 		 * returning the value we actually used in getsockopt
831 		 * is the most desirable behavior.
832 		 */
833 		WRITE_ONCE(sk->sk_rcvbuf,
834 			   max_t(int, val * 2, SOCK_MIN_RCVBUF));
835 		break;
836 
837 	case SO_RCVBUFFORCE:
838 		if (!capable(CAP_NET_ADMIN)) {
839 			ret = -EPERM;
840 			break;
841 		}
842 
843 		/* No negative values (to prevent underflow, as val will be
844 		 * multiplied by 2).
845 		 */
846 		if (val < 0)
847 			val = 0;
848 		goto set_rcvbuf;
849 
850 	case SO_KEEPALIVE:
851 		if (sk->sk_prot->keepalive)
852 			sk->sk_prot->keepalive(sk, valbool);
853 		sock_valbool_flag(sk, SOCK_KEEPOPEN, valbool);
854 		break;
855 
856 	case SO_OOBINLINE:
857 		sock_valbool_flag(sk, SOCK_URGINLINE, valbool);
858 		break;
859 
860 	case SO_NO_CHECK:
861 		sk->sk_no_check_tx = valbool;
862 		break;
863 
864 	case SO_PRIORITY:
865 		if ((val >= 0 && val <= 6) ||
866 		    ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
867 			sk->sk_priority = val;
868 		else
869 			ret = -EPERM;
870 		break;
871 
872 	case SO_LINGER:
873 		if (optlen < sizeof(ling)) {
874 			ret = -EINVAL;	/* 1003.1g */
875 			break;
876 		}
877 		if (copy_from_user(&ling, optval, sizeof(ling))) {
878 			ret = -EFAULT;
879 			break;
880 		}
881 		if (!ling.l_onoff)
882 			sock_reset_flag(sk, SOCK_LINGER);
883 		else {
884 #if (BITS_PER_LONG == 32)
885 			if ((unsigned int)ling.l_linger >= MAX_SCHEDULE_TIMEOUT/HZ)
886 				sk->sk_lingertime = MAX_SCHEDULE_TIMEOUT;
887 			else
888 #endif
889 				sk->sk_lingertime = (unsigned int)ling.l_linger * HZ;
890 			sock_set_flag(sk, SOCK_LINGER);
891 		}
892 		break;
893 
894 	case SO_BSDCOMPAT:
895 		sock_warn_obsolete_bsdism("setsockopt");
896 		break;
897 
898 	case SO_PASSCRED:
899 		if (valbool)
900 			set_bit(SOCK_PASSCRED, &sock->flags);
901 		else
902 			clear_bit(SOCK_PASSCRED, &sock->flags);
903 		break;
904 
905 	case SO_TIMESTAMP_OLD:
906 	case SO_TIMESTAMP_NEW:
907 	case SO_TIMESTAMPNS_OLD:
908 	case SO_TIMESTAMPNS_NEW:
909 		if (valbool)  {
910 			if (optname == SO_TIMESTAMP_NEW || optname == SO_TIMESTAMPNS_NEW)
911 				sock_set_flag(sk, SOCK_TSTAMP_NEW);
912 			else
913 				sock_reset_flag(sk, SOCK_TSTAMP_NEW);
914 
915 			if (optname == SO_TIMESTAMP_OLD || optname == SO_TIMESTAMP_NEW)
916 				sock_reset_flag(sk, SOCK_RCVTSTAMPNS);
917 			else
918 				sock_set_flag(sk, SOCK_RCVTSTAMPNS);
919 			sock_set_flag(sk, SOCK_RCVTSTAMP);
920 			sock_enable_timestamp(sk, SOCK_TIMESTAMP);
921 		} else {
922 			sock_reset_flag(sk, SOCK_RCVTSTAMP);
923 			sock_reset_flag(sk, SOCK_RCVTSTAMPNS);
924 			sock_reset_flag(sk, SOCK_TSTAMP_NEW);
925 		}
926 		break;
927 
928 	case SO_TIMESTAMPING_NEW:
929 		sock_set_flag(sk, SOCK_TSTAMP_NEW);
930 		/* fall through */
931 	case SO_TIMESTAMPING_OLD:
932 		if (val & ~SOF_TIMESTAMPING_MASK) {
933 			ret = -EINVAL;
934 			break;
935 		}
936 
937 		if (val & SOF_TIMESTAMPING_OPT_ID &&
938 		    !(sk->sk_tsflags & SOF_TIMESTAMPING_OPT_ID)) {
939 			if (sk->sk_protocol == IPPROTO_TCP &&
940 			    sk->sk_type == SOCK_STREAM) {
941 				if ((1 << sk->sk_state) &
942 				    (TCPF_CLOSE | TCPF_LISTEN)) {
943 					ret = -EINVAL;
944 					break;
945 				}
946 				sk->sk_tskey = tcp_sk(sk)->snd_una;
947 			} else {
948 				sk->sk_tskey = 0;
949 			}
950 		}
951 
952 		if (val & SOF_TIMESTAMPING_OPT_STATS &&
953 		    !(val & SOF_TIMESTAMPING_OPT_TSONLY)) {
954 			ret = -EINVAL;
955 			break;
956 		}
957 
958 		sk->sk_tsflags = val;
959 		if (val & SOF_TIMESTAMPING_RX_SOFTWARE)
960 			sock_enable_timestamp(sk,
961 					      SOCK_TIMESTAMPING_RX_SOFTWARE);
962 		else {
963 			if (optname == SO_TIMESTAMPING_NEW)
964 				sock_reset_flag(sk, SOCK_TSTAMP_NEW);
965 
966 			sock_disable_timestamp(sk,
967 					       (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE));
968 		}
969 		break;
970 
971 	case SO_RCVLOWAT:
972 		if (val < 0)
973 			val = INT_MAX;
974 		if (sock->ops->set_rcvlowat)
975 			ret = sock->ops->set_rcvlowat(sk, val);
976 		else
977 			WRITE_ONCE(sk->sk_rcvlowat, val ? : 1);
978 		break;
979 
980 	case SO_RCVTIMEO_OLD:
981 	case SO_RCVTIMEO_NEW:
982 		ret = sock_set_timeout(&sk->sk_rcvtimeo, optval, optlen, optname == SO_RCVTIMEO_OLD);
983 		break;
984 
985 	case SO_SNDTIMEO_OLD:
986 	case SO_SNDTIMEO_NEW:
987 		ret = sock_set_timeout(&sk->sk_sndtimeo, optval, optlen, optname == SO_SNDTIMEO_OLD);
988 		break;
989 
990 	case SO_ATTACH_FILTER:
991 		ret = -EINVAL;
992 		if (optlen == sizeof(struct sock_fprog)) {
993 			struct sock_fprog fprog;
994 
995 			ret = -EFAULT;
996 			if (copy_from_user(&fprog, optval, sizeof(fprog)))
997 				break;
998 
999 			ret = sk_attach_filter(&fprog, sk);
1000 		}
1001 		break;
1002 
1003 	case SO_ATTACH_BPF:
1004 		ret = -EINVAL;
1005 		if (optlen == sizeof(u32)) {
1006 			u32 ufd;
1007 
1008 			ret = -EFAULT;
1009 			if (copy_from_user(&ufd, optval, sizeof(ufd)))
1010 				break;
1011 
1012 			ret = sk_attach_bpf(ufd, sk);
1013 		}
1014 		break;
1015 
1016 	case SO_ATTACH_REUSEPORT_CBPF:
1017 		ret = -EINVAL;
1018 		if (optlen == sizeof(struct sock_fprog)) {
1019 			struct sock_fprog fprog;
1020 
1021 			ret = -EFAULT;
1022 			if (copy_from_user(&fprog, optval, sizeof(fprog)))
1023 				break;
1024 
1025 			ret = sk_reuseport_attach_filter(&fprog, sk);
1026 		}
1027 		break;
1028 
1029 	case SO_ATTACH_REUSEPORT_EBPF:
1030 		ret = -EINVAL;
1031 		if (optlen == sizeof(u32)) {
1032 			u32 ufd;
1033 
1034 			ret = -EFAULT;
1035 			if (copy_from_user(&ufd, optval, sizeof(ufd)))
1036 				break;
1037 
1038 			ret = sk_reuseport_attach_bpf(ufd, sk);
1039 		}
1040 		break;
1041 
1042 	case SO_DETACH_REUSEPORT_BPF:
1043 		ret = reuseport_detach_prog(sk);
1044 		break;
1045 
1046 	case SO_DETACH_FILTER:
1047 		ret = sk_detach_filter(sk);
1048 		break;
1049 
1050 	case SO_LOCK_FILTER:
1051 		if (sock_flag(sk, SOCK_FILTER_LOCKED) && !valbool)
1052 			ret = -EPERM;
1053 		else
1054 			sock_valbool_flag(sk, SOCK_FILTER_LOCKED, valbool);
1055 		break;
1056 
1057 	case SO_PASSSEC:
1058 		if (valbool)
1059 			set_bit(SOCK_PASSSEC, &sock->flags);
1060 		else
1061 			clear_bit(SOCK_PASSSEC, &sock->flags);
1062 		break;
1063 	case SO_MARK:
1064 		if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) {
1065 			ret = -EPERM;
1066 		} else if (val != sk->sk_mark) {
1067 			sk->sk_mark = val;
1068 			sk_dst_reset(sk);
1069 		}
1070 		break;
1071 
1072 	case SO_RXQ_OVFL:
1073 		sock_valbool_flag(sk, SOCK_RXQ_OVFL, valbool);
1074 		break;
1075 
1076 	case SO_WIFI_STATUS:
1077 		sock_valbool_flag(sk, SOCK_WIFI_STATUS, valbool);
1078 		break;
1079 
1080 	case SO_PEEK_OFF:
1081 		if (sock->ops->set_peek_off)
1082 			ret = sock->ops->set_peek_off(sk, val);
1083 		else
1084 			ret = -EOPNOTSUPP;
1085 		break;
1086 
1087 	case SO_NOFCS:
1088 		sock_valbool_flag(sk, SOCK_NOFCS, valbool);
1089 		break;
1090 
1091 	case SO_SELECT_ERR_QUEUE:
1092 		sock_valbool_flag(sk, SOCK_SELECT_ERR_QUEUE, valbool);
1093 		break;
1094 
1095 #ifdef CONFIG_NET_RX_BUSY_POLL
1096 	case SO_BUSY_POLL:
1097 		/* allow unprivileged users to decrease the value */
1098 		if ((val > sk->sk_ll_usec) && !capable(CAP_NET_ADMIN))
1099 			ret = -EPERM;
1100 		else {
1101 			if (val < 0)
1102 				ret = -EINVAL;
1103 			else
1104 				sk->sk_ll_usec = val;
1105 		}
1106 		break;
1107 #endif
1108 
1109 	case SO_MAX_PACING_RATE:
1110 		{
1111 		unsigned long ulval = (val == ~0U) ? ~0UL : val;
1112 
1113 		if (sizeof(ulval) != sizeof(val) &&
1114 		    optlen >= sizeof(ulval) &&
1115 		    get_user(ulval, (unsigned long __user *)optval)) {
1116 			ret = -EFAULT;
1117 			break;
1118 		}
1119 		if (ulval != ~0UL)
1120 			cmpxchg(&sk->sk_pacing_status,
1121 				SK_PACING_NONE,
1122 				SK_PACING_NEEDED);
1123 		sk->sk_max_pacing_rate = ulval;
1124 		sk->sk_pacing_rate = min(sk->sk_pacing_rate, ulval);
1125 		break;
1126 		}
1127 	case SO_INCOMING_CPU:
1128 		WRITE_ONCE(sk->sk_incoming_cpu, val);
1129 		break;
1130 
1131 	case SO_CNX_ADVICE:
1132 		if (val == 1)
1133 			dst_negative_advice(sk);
1134 		break;
1135 
1136 	case SO_ZEROCOPY:
1137 		if (sk->sk_family == PF_INET || sk->sk_family == PF_INET6) {
1138 			if (!((sk->sk_type == SOCK_STREAM &&
1139 			       sk->sk_protocol == IPPROTO_TCP) ||
1140 			      (sk->sk_type == SOCK_DGRAM &&
1141 			       sk->sk_protocol == IPPROTO_UDP)))
1142 				ret = -ENOTSUPP;
1143 		} else if (sk->sk_family != PF_RDS) {
1144 			ret = -ENOTSUPP;
1145 		}
1146 		if (!ret) {
1147 			if (val < 0 || val > 1)
1148 				ret = -EINVAL;
1149 			else
1150 				sock_valbool_flag(sk, SOCK_ZEROCOPY, valbool);
1151 		}
1152 		break;
1153 
1154 	case SO_TXTIME:
1155 		if (optlen != sizeof(struct sock_txtime)) {
1156 			ret = -EINVAL;
1157 			break;
1158 		} else if (copy_from_user(&sk_txtime, optval,
1159 			   sizeof(struct sock_txtime))) {
1160 			ret = -EFAULT;
1161 			break;
1162 		} else if (sk_txtime.flags & ~SOF_TXTIME_FLAGS_MASK) {
1163 			ret = -EINVAL;
1164 			break;
1165 		}
1166 		/* CLOCK_MONOTONIC is only used by sch_fq, and this packet
1167 		 * scheduler has enough safe guards.
1168 		 */
1169 		if (sk_txtime.clockid != CLOCK_MONOTONIC &&
1170 		    !ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) {
1171 			ret = -EPERM;
1172 			break;
1173 		}
1174 		sock_valbool_flag(sk, SOCK_TXTIME, true);
1175 		sk->sk_clockid = sk_txtime.clockid;
1176 		sk->sk_txtime_deadline_mode =
1177 			!!(sk_txtime.flags & SOF_TXTIME_DEADLINE_MODE);
1178 		sk->sk_txtime_report_errors =
1179 			!!(sk_txtime.flags & SOF_TXTIME_REPORT_ERRORS);
1180 		break;
1181 
1182 	case SO_BINDTOIFINDEX:
1183 		ret = sock_setbindtodevice_locked(sk, val);
1184 		break;
1185 
1186 	default:
1187 		ret = -ENOPROTOOPT;
1188 		break;
1189 	}
1190 	release_sock(sk);
1191 	return ret;
1192 }
1193 EXPORT_SYMBOL(sock_setsockopt);
1194 
1195 
1196 static void cred_to_ucred(struct pid *pid, const struct cred *cred,
1197 			  struct ucred *ucred)
1198 {
1199 	ucred->pid = pid_vnr(pid);
1200 	ucred->uid = ucred->gid = -1;
1201 	if (cred) {
1202 		struct user_namespace *current_ns = current_user_ns();
1203 
1204 		ucred->uid = from_kuid_munged(current_ns, cred->euid);
1205 		ucred->gid = from_kgid_munged(current_ns, cred->egid);
1206 	}
1207 }
1208 
1209 static int groups_to_user(gid_t __user *dst, const struct group_info *src)
1210 {
1211 	struct user_namespace *user_ns = current_user_ns();
1212 	int i;
1213 
1214 	for (i = 0; i < src->ngroups; i++)
1215 		if (put_user(from_kgid_munged(user_ns, src->gid[i]), dst + i))
1216 			return -EFAULT;
1217 
1218 	return 0;
1219 }
1220 
1221 int sock_getsockopt(struct socket *sock, int level, int optname,
1222 		    char __user *optval, int __user *optlen)
1223 {
1224 	struct sock *sk = sock->sk;
1225 
1226 	union {
1227 		int val;
1228 		u64 val64;
1229 		unsigned long ulval;
1230 		struct linger ling;
1231 		struct old_timeval32 tm32;
1232 		struct __kernel_old_timeval tm;
1233 		struct  __kernel_sock_timeval stm;
1234 		struct sock_txtime txtime;
1235 	} v;
1236 
1237 	int lv = sizeof(int);
1238 	int len;
1239 
1240 	if (get_user(len, optlen))
1241 		return -EFAULT;
1242 	if (len < 0)
1243 		return -EINVAL;
1244 
1245 	memset(&v, 0, sizeof(v));
1246 
1247 	switch (optname) {
1248 	case SO_DEBUG:
1249 		v.val = sock_flag(sk, SOCK_DBG);
1250 		break;
1251 
1252 	case SO_DONTROUTE:
1253 		v.val = sock_flag(sk, SOCK_LOCALROUTE);
1254 		break;
1255 
1256 	case SO_BROADCAST:
1257 		v.val = sock_flag(sk, SOCK_BROADCAST);
1258 		break;
1259 
1260 	case SO_SNDBUF:
1261 		v.val = sk->sk_sndbuf;
1262 		break;
1263 
1264 	case SO_RCVBUF:
1265 		v.val = sk->sk_rcvbuf;
1266 		break;
1267 
1268 	case SO_REUSEADDR:
1269 		v.val = sk->sk_reuse;
1270 		break;
1271 
1272 	case SO_REUSEPORT:
1273 		v.val = sk->sk_reuseport;
1274 		break;
1275 
1276 	case SO_KEEPALIVE:
1277 		v.val = sock_flag(sk, SOCK_KEEPOPEN);
1278 		break;
1279 
1280 	case SO_TYPE:
1281 		v.val = sk->sk_type;
1282 		break;
1283 
1284 	case SO_PROTOCOL:
1285 		v.val = sk->sk_protocol;
1286 		break;
1287 
1288 	case SO_DOMAIN:
1289 		v.val = sk->sk_family;
1290 		break;
1291 
1292 	case SO_ERROR:
1293 		v.val = -sock_error(sk);
1294 		if (v.val == 0)
1295 			v.val = xchg(&sk->sk_err_soft, 0);
1296 		break;
1297 
1298 	case SO_OOBINLINE:
1299 		v.val = sock_flag(sk, SOCK_URGINLINE);
1300 		break;
1301 
1302 	case SO_NO_CHECK:
1303 		v.val = sk->sk_no_check_tx;
1304 		break;
1305 
1306 	case SO_PRIORITY:
1307 		v.val = sk->sk_priority;
1308 		break;
1309 
1310 	case SO_LINGER:
1311 		lv		= sizeof(v.ling);
1312 		v.ling.l_onoff	= sock_flag(sk, SOCK_LINGER);
1313 		v.ling.l_linger	= sk->sk_lingertime / HZ;
1314 		break;
1315 
1316 	case SO_BSDCOMPAT:
1317 		sock_warn_obsolete_bsdism("getsockopt");
1318 		break;
1319 
1320 	case SO_TIMESTAMP_OLD:
1321 		v.val = sock_flag(sk, SOCK_RCVTSTAMP) &&
1322 				!sock_flag(sk, SOCK_TSTAMP_NEW) &&
1323 				!sock_flag(sk, SOCK_RCVTSTAMPNS);
1324 		break;
1325 
1326 	case SO_TIMESTAMPNS_OLD:
1327 		v.val = sock_flag(sk, SOCK_RCVTSTAMPNS) && !sock_flag(sk, SOCK_TSTAMP_NEW);
1328 		break;
1329 
1330 	case SO_TIMESTAMP_NEW:
1331 		v.val = sock_flag(sk, SOCK_RCVTSTAMP) && sock_flag(sk, SOCK_TSTAMP_NEW);
1332 		break;
1333 
1334 	case SO_TIMESTAMPNS_NEW:
1335 		v.val = sock_flag(sk, SOCK_RCVTSTAMPNS) && sock_flag(sk, SOCK_TSTAMP_NEW);
1336 		break;
1337 
1338 	case SO_TIMESTAMPING_OLD:
1339 		v.val = sk->sk_tsflags;
1340 		break;
1341 
1342 	case SO_RCVTIMEO_OLD:
1343 	case SO_RCVTIMEO_NEW:
1344 		lv = sock_get_timeout(sk->sk_rcvtimeo, &v, SO_RCVTIMEO_OLD == optname);
1345 		break;
1346 
1347 	case SO_SNDTIMEO_OLD:
1348 	case SO_SNDTIMEO_NEW:
1349 		lv = sock_get_timeout(sk->sk_sndtimeo, &v, SO_SNDTIMEO_OLD == optname);
1350 		break;
1351 
1352 	case SO_RCVLOWAT:
1353 		v.val = sk->sk_rcvlowat;
1354 		break;
1355 
1356 	case SO_SNDLOWAT:
1357 		v.val = 1;
1358 		break;
1359 
1360 	case SO_PASSCRED:
1361 		v.val = !!test_bit(SOCK_PASSCRED, &sock->flags);
1362 		break;
1363 
1364 	case SO_PEERCRED:
1365 	{
1366 		struct ucred peercred;
1367 		if (len > sizeof(peercred))
1368 			len = sizeof(peercred);
1369 		cred_to_ucred(sk->sk_peer_pid, sk->sk_peer_cred, &peercred);
1370 		if (copy_to_user(optval, &peercred, len))
1371 			return -EFAULT;
1372 		goto lenout;
1373 	}
1374 
1375 	case SO_PEERGROUPS:
1376 	{
1377 		int ret, n;
1378 
1379 		if (!sk->sk_peer_cred)
1380 			return -ENODATA;
1381 
1382 		n = sk->sk_peer_cred->group_info->ngroups;
1383 		if (len < n * sizeof(gid_t)) {
1384 			len = n * sizeof(gid_t);
1385 			return put_user(len, optlen) ? -EFAULT : -ERANGE;
1386 		}
1387 		len = n * sizeof(gid_t);
1388 
1389 		ret = groups_to_user((gid_t __user *)optval,
1390 				     sk->sk_peer_cred->group_info);
1391 		if (ret)
1392 			return ret;
1393 		goto lenout;
1394 	}
1395 
1396 	case SO_PEERNAME:
1397 	{
1398 		char address[128];
1399 
1400 		lv = sock->ops->getname(sock, (struct sockaddr *)address, 2);
1401 		if (lv < 0)
1402 			return -ENOTCONN;
1403 		if (lv < len)
1404 			return -EINVAL;
1405 		if (copy_to_user(optval, address, len))
1406 			return -EFAULT;
1407 		goto lenout;
1408 	}
1409 
1410 	/* Dubious BSD thing... Probably nobody even uses it, but
1411 	 * the UNIX standard wants it for whatever reason... -DaveM
1412 	 */
1413 	case SO_ACCEPTCONN:
1414 		v.val = sk->sk_state == TCP_LISTEN;
1415 		break;
1416 
1417 	case SO_PASSSEC:
1418 		v.val = !!test_bit(SOCK_PASSSEC, &sock->flags);
1419 		break;
1420 
1421 	case SO_PEERSEC:
1422 		return security_socket_getpeersec_stream(sock, optval, optlen, len);
1423 
1424 	case SO_MARK:
1425 		v.val = sk->sk_mark;
1426 		break;
1427 
1428 	case SO_RXQ_OVFL:
1429 		v.val = sock_flag(sk, SOCK_RXQ_OVFL);
1430 		break;
1431 
1432 	case SO_WIFI_STATUS:
1433 		v.val = sock_flag(sk, SOCK_WIFI_STATUS);
1434 		break;
1435 
1436 	case SO_PEEK_OFF:
1437 		if (!sock->ops->set_peek_off)
1438 			return -EOPNOTSUPP;
1439 
1440 		v.val = sk->sk_peek_off;
1441 		break;
1442 	case SO_NOFCS:
1443 		v.val = sock_flag(sk, SOCK_NOFCS);
1444 		break;
1445 
1446 	case SO_BINDTODEVICE:
1447 		return sock_getbindtodevice(sk, optval, optlen, len);
1448 
1449 	case SO_GET_FILTER:
1450 		len = sk_get_filter(sk, (struct sock_filter __user *)optval, len);
1451 		if (len < 0)
1452 			return len;
1453 
1454 		goto lenout;
1455 
1456 	case SO_LOCK_FILTER:
1457 		v.val = sock_flag(sk, SOCK_FILTER_LOCKED);
1458 		break;
1459 
1460 	case SO_BPF_EXTENSIONS:
1461 		v.val = bpf_tell_extensions();
1462 		break;
1463 
1464 	case SO_SELECT_ERR_QUEUE:
1465 		v.val = sock_flag(sk, SOCK_SELECT_ERR_QUEUE);
1466 		break;
1467 
1468 #ifdef CONFIG_NET_RX_BUSY_POLL
1469 	case SO_BUSY_POLL:
1470 		v.val = sk->sk_ll_usec;
1471 		break;
1472 #endif
1473 
1474 	case SO_MAX_PACING_RATE:
1475 		if (sizeof(v.ulval) != sizeof(v.val) && len >= sizeof(v.ulval)) {
1476 			lv = sizeof(v.ulval);
1477 			v.ulval = sk->sk_max_pacing_rate;
1478 		} else {
1479 			/* 32bit version */
1480 			v.val = min_t(unsigned long, sk->sk_max_pacing_rate, ~0U);
1481 		}
1482 		break;
1483 
1484 	case SO_INCOMING_CPU:
1485 		v.val = READ_ONCE(sk->sk_incoming_cpu);
1486 		break;
1487 
1488 	case SO_MEMINFO:
1489 	{
1490 		u32 meminfo[SK_MEMINFO_VARS];
1491 
1492 		sk_get_meminfo(sk, meminfo);
1493 
1494 		len = min_t(unsigned int, len, sizeof(meminfo));
1495 		if (copy_to_user(optval, &meminfo, len))
1496 			return -EFAULT;
1497 
1498 		goto lenout;
1499 	}
1500 
1501 #ifdef CONFIG_NET_RX_BUSY_POLL
1502 	case SO_INCOMING_NAPI_ID:
1503 		v.val = READ_ONCE(sk->sk_napi_id);
1504 
1505 		/* aggregate non-NAPI IDs down to 0 */
1506 		if (v.val < MIN_NAPI_ID)
1507 			v.val = 0;
1508 
1509 		break;
1510 #endif
1511 
1512 	case SO_COOKIE:
1513 		lv = sizeof(u64);
1514 		if (len < lv)
1515 			return -EINVAL;
1516 		v.val64 = sock_gen_cookie(sk);
1517 		break;
1518 
1519 	case SO_ZEROCOPY:
1520 		v.val = sock_flag(sk, SOCK_ZEROCOPY);
1521 		break;
1522 
1523 	case SO_TXTIME:
1524 		lv = sizeof(v.txtime);
1525 		v.txtime.clockid = sk->sk_clockid;
1526 		v.txtime.flags |= sk->sk_txtime_deadline_mode ?
1527 				  SOF_TXTIME_DEADLINE_MODE : 0;
1528 		v.txtime.flags |= sk->sk_txtime_report_errors ?
1529 				  SOF_TXTIME_REPORT_ERRORS : 0;
1530 		break;
1531 
1532 	case SO_BINDTOIFINDEX:
1533 		v.val = sk->sk_bound_dev_if;
1534 		break;
1535 
1536 	default:
1537 		/* We implement the SO_SNDLOWAT etc to not be settable
1538 		 * (1003.1g 7).
1539 		 */
1540 		return -ENOPROTOOPT;
1541 	}
1542 
1543 	if (len > lv)
1544 		len = lv;
1545 	if (copy_to_user(optval, &v, len))
1546 		return -EFAULT;
1547 lenout:
1548 	if (put_user(len, optlen))
1549 		return -EFAULT;
1550 	return 0;
1551 }
1552 
1553 /*
1554  * Initialize an sk_lock.
1555  *
1556  * (We also register the sk_lock with the lock validator.)
1557  */
1558 static inline void sock_lock_init(struct sock *sk)
1559 {
1560 	if (sk->sk_kern_sock)
1561 		sock_lock_init_class_and_name(
1562 			sk,
1563 			af_family_kern_slock_key_strings[sk->sk_family],
1564 			af_family_kern_slock_keys + sk->sk_family,
1565 			af_family_kern_key_strings[sk->sk_family],
1566 			af_family_kern_keys + sk->sk_family);
1567 	else
1568 		sock_lock_init_class_and_name(
1569 			sk,
1570 			af_family_slock_key_strings[sk->sk_family],
1571 			af_family_slock_keys + sk->sk_family,
1572 			af_family_key_strings[sk->sk_family],
1573 			af_family_keys + sk->sk_family);
1574 }
1575 
1576 /*
1577  * Copy all fields from osk to nsk but nsk->sk_refcnt must not change yet,
1578  * even temporarly, because of RCU lookups. sk_node should also be left as is.
1579  * We must not copy fields between sk_dontcopy_begin and sk_dontcopy_end
1580  */
1581 static void sock_copy(struct sock *nsk, const struct sock *osk)
1582 {
1583 	const struct proto *prot = READ_ONCE(osk->sk_prot);
1584 #ifdef CONFIG_SECURITY_NETWORK
1585 	void *sptr = nsk->sk_security;
1586 #endif
1587 	memcpy(nsk, osk, offsetof(struct sock, sk_dontcopy_begin));
1588 
1589 	memcpy(&nsk->sk_dontcopy_end, &osk->sk_dontcopy_end,
1590 	       prot->obj_size - offsetof(struct sock, sk_dontcopy_end));
1591 
1592 #ifdef CONFIG_SECURITY_NETWORK
1593 	nsk->sk_security = sptr;
1594 	security_sk_clone(osk, nsk);
1595 #endif
1596 }
1597 
1598 static struct sock *sk_prot_alloc(struct proto *prot, gfp_t priority,
1599 		int family)
1600 {
1601 	struct sock *sk;
1602 	struct kmem_cache *slab;
1603 
1604 	slab = prot->slab;
1605 	if (slab != NULL) {
1606 		sk = kmem_cache_alloc(slab, priority & ~__GFP_ZERO);
1607 		if (!sk)
1608 			return sk;
1609 		if (want_init_on_alloc(priority))
1610 			sk_prot_clear_nulls(sk, prot->obj_size);
1611 	} else
1612 		sk = kmalloc(prot->obj_size, priority);
1613 
1614 	if (sk != NULL) {
1615 		if (security_sk_alloc(sk, family, priority))
1616 			goto out_free;
1617 
1618 		if (!try_module_get(prot->owner))
1619 			goto out_free_sec;
1620 		sk_tx_queue_clear(sk);
1621 	}
1622 
1623 	return sk;
1624 
1625 out_free_sec:
1626 	security_sk_free(sk);
1627 out_free:
1628 	if (slab != NULL)
1629 		kmem_cache_free(slab, sk);
1630 	else
1631 		kfree(sk);
1632 	return NULL;
1633 }
1634 
1635 static void sk_prot_free(struct proto *prot, struct sock *sk)
1636 {
1637 	struct kmem_cache *slab;
1638 	struct module *owner;
1639 
1640 	owner = prot->owner;
1641 	slab = prot->slab;
1642 
1643 	cgroup_sk_free(&sk->sk_cgrp_data);
1644 	mem_cgroup_sk_free(sk);
1645 	security_sk_free(sk);
1646 	if (slab != NULL)
1647 		kmem_cache_free(slab, sk);
1648 	else
1649 		kfree(sk);
1650 	module_put(owner);
1651 }
1652 
1653 /**
1654  *	sk_alloc - All socket objects are allocated here
1655  *	@net: the applicable net namespace
1656  *	@family: protocol family
1657  *	@priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
1658  *	@prot: struct proto associated with this new sock instance
1659  *	@kern: is this to be a kernel socket?
1660  */
1661 struct sock *sk_alloc(struct net *net, int family, gfp_t priority,
1662 		      struct proto *prot, int kern)
1663 {
1664 	struct sock *sk;
1665 
1666 	sk = sk_prot_alloc(prot, priority | __GFP_ZERO, family);
1667 	if (sk) {
1668 		sk->sk_family = family;
1669 		/*
1670 		 * See comment in struct sock definition to understand
1671 		 * why we need sk_prot_creator -acme
1672 		 */
1673 		sk->sk_prot = sk->sk_prot_creator = prot;
1674 		sk->sk_kern_sock = kern;
1675 		sock_lock_init(sk);
1676 		sk->sk_net_refcnt = kern ? 0 : 1;
1677 		if (likely(sk->sk_net_refcnt)) {
1678 			get_net(net);
1679 			sock_inuse_add(net, 1);
1680 		}
1681 
1682 		sock_net_set(sk, net);
1683 		refcount_set(&sk->sk_wmem_alloc, 1);
1684 
1685 		mem_cgroup_sk_alloc(sk);
1686 		cgroup_sk_alloc(&sk->sk_cgrp_data);
1687 		sock_update_classid(&sk->sk_cgrp_data);
1688 		sock_update_netprioidx(&sk->sk_cgrp_data);
1689 	}
1690 
1691 	return sk;
1692 }
1693 EXPORT_SYMBOL(sk_alloc);
1694 
1695 /* Sockets having SOCK_RCU_FREE will call this function after one RCU
1696  * grace period. This is the case for UDP sockets and TCP listeners.
1697  */
1698 static void __sk_destruct(struct rcu_head *head)
1699 {
1700 	struct sock *sk = container_of(head, struct sock, sk_rcu);
1701 	struct sk_filter *filter;
1702 
1703 	if (sk->sk_destruct)
1704 		sk->sk_destruct(sk);
1705 
1706 	filter = rcu_dereference_check(sk->sk_filter,
1707 				       refcount_read(&sk->sk_wmem_alloc) == 0);
1708 	if (filter) {
1709 		sk_filter_uncharge(sk, filter);
1710 		RCU_INIT_POINTER(sk->sk_filter, NULL);
1711 	}
1712 
1713 	sock_disable_timestamp(sk, SK_FLAGS_TIMESTAMP);
1714 
1715 #ifdef CONFIG_BPF_SYSCALL
1716 	bpf_sk_storage_free(sk);
1717 #endif
1718 
1719 	if (atomic_read(&sk->sk_omem_alloc))
1720 		pr_debug("%s: optmem leakage (%d bytes) detected\n",
1721 			 __func__, atomic_read(&sk->sk_omem_alloc));
1722 
1723 	if (sk->sk_frag.page) {
1724 		put_page(sk->sk_frag.page);
1725 		sk->sk_frag.page = NULL;
1726 	}
1727 
1728 	if (sk->sk_peer_cred)
1729 		put_cred(sk->sk_peer_cred);
1730 	put_pid(sk->sk_peer_pid);
1731 	if (likely(sk->sk_net_refcnt))
1732 		put_net(sock_net(sk));
1733 	sk_prot_free(sk->sk_prot_creator, sk);
1734 }
1735 
1736 void sk_destruct(struct sock *sk)
1737 {
1738 	bool use_call_rcu = sock_flag(sk, SOCK_RCU_FREE);
1739 
1740 	if (rcu_access_pointer(sk->sk_reuseport_cb)) {
1741 		reuseport_detach_sock(sk);
1742 		use_call_rcu = true;
1743 	}
1744 
1745 	if (use_call_rcu)
1746 		call_rcu(&sk->sk_rcu, __sk_destruct);
1747 	else
1748 		__sk_destruct(&sk->sk_rcu);
1749 }
1750 
1751 static void __sk_free(struct sock *sk)
1752 {
1753 	if (likely(sk->sk_net_refcnt))
1754 		sock_inuse_add(sock_net(sk), -1);
1755 
1756 	if (unlikely(sk->sk_net_refcnt && sock_diag_has_destroy_listeners(sk)))
1757 		sock_diag_broadcast_destroy(sk);
1758 	else
1759 		sk_destruct(sk);
1760 }
1761 
1762 void sk_free(struct sock *sk)
1763 {
1764 	/*
1765 	 * We subtract one from sk_wmem_alloc and can know if
1766 	 * some packets are still in some tx queue.
1767 	 * If not null, sock_wfree() will call __sk_free(sk) later
1768 	 */
1769 	if (refcount_dec_and_test(&sk->sk_wmem_alloc))
1770 		__sk_free(sk);
1771 }
1772 EXPORT_SYMBOL(sk_free);
1773 
1774 static void sk_init_common(struct sock *sk)
1775 {
1776 	skb_queue_head_init(&sk->sk_receive_queue);
1777 	skb_queue_head_init(&sk->sk_write_queue);
1778 	skb_queue_head_init(&sk->sk_error_queue);
1779 
1780 	rwlock_init(&sk->sk_callback_lock);
1781 	lockdep_set_class_and_name(&sk->sk_receive_queue.lock,
1782 			af_rlock_keys + sk->sk_family,
1783 			af_family_rlock_key_strings[sk->sk_family]);
1784 	lockdep_set_class_and_name(&sk->sk_write_queue.lock,
1785 			af_wlock_keys + sk->sk_family,
1786 			af_family_wlock_key_strings[sk->sk_family]);
1787 	lockdep_set_class_and_name(&sk->sk_error_queue.lock,
1788 			af_elock_keys + sk->sk_family,
1789 			af_family_elock_key_strings[sk->sk_family]);
1790 	lockdep_set_class_and_name(&sk->sk_callback_lock,
1791 			af_callback_keys + sk->sk_family,
1792 			af_family_clock_key_strings[sk->sk_family]);
1793 }
1794 
1795 /**
1796  *	sk_clone_lock - clone a socket, and lock its clone
1797  *	@sk: the socket to clone
1798  *	@priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
1799  *
1800  *	Caller must unlock socket even in error path (bh_unlock_sock(newsk))
1801  */
1802 struct sock *sk_clone_lock(const struct sock *sk, const gfp_t priority)
1803 {
1804 	struct proto *prot = READ_ONCE(sk->sk_prot);
1805 	struct sock *newsk;
1806 	bool is_charged = true;
1807 
1808 	newsk = sk_prot_alloc(prot, priority, sk->sk_family);
1809 	if (newsk != NULL) {
1810 		struct sk_filter *filter;
1811 
1812 		sock_copy(newsk, sk);
1813 
1814 		newsk->sk_prot_creator = prot;
1815 
1816 		/* SANITY */
1817 		if (likely(newsk->sk_net_refcnt))
1818 			get_net(sock_net(newsk));
1819 		sk_node_init(&newsk->sk_node);
1820 		sock_lock_init(newsk);
1821 		bh_lock_sock(newsk);
1822 		newsk->sk_backlog.head	= newsk->sk_backlog.tail = NULL;
1823 		newsk->sk_backlog.len = 0;
1824 
1825 		atomic_set(&newsk->sk_rmem_alloc, 0);
1826 		/*
1827 		 * sk_wmem_alloc set to one (see sk_free() and sock_wfree())
1828 		 */
1829 		refcount_set(&newsk->sk_wmem_alloc, 1);
1830 		atomic_set(&newsk->sk_omem_alloc, 0);
1831 		sk_init_common(newsk);
1832 
1833 		newsk->sk_dst_cache	= NULL;
1834 		newsk->sk_dst_pending_confirm = 0;
1835 		newsk->sk_wmem_queued	= 0;
1836 		newsk->sk_forward_alloc = 0;
1837 		atomic_set(&newsk->sk_drops, 0);
1838 		newsk->sk_send_head	= NULL;
1839 		newsk->sk_userlocks	= sk->sk_userlocks & ~SOCK_BINDPORT_LOCK;
1840 		atomic_set(&newsk->sk_zckey, 0);
1841 
1842 		sock_reset_flag(newsk, SOCK_DONE);
1843 
1844 		/* sk->sk_memcg will be populated at accept() time */
1845 		newsk->sk_memcg = NULL;
1846 
1847 		cgroup_sk_alloc(&newsk->sk_cgrp_data);
1848 
1849 		rcu_read_lock();
1850 		filter = rcu_dereference(sk->sk_filter);
1851 		if (filter != NULL)
1852 			/* though it's an empty new sock, the charging may fail
1853 			 * if sysctl_optmem_max was changed between creation of
1854 			 * original socket and cloning
1855 			 */
1856 			is_charged = sk_filter_charge(newsk, filter);
1857 		RCU_INIT_POINTER(newsk->sk_filter, filter);
1858 		rcu_read_unlock();
1859 
1860 		if (unlikely(!is_charged || xfrm_sk_clone_policy(newsk, sk))) {
1861 			/* We need to make sure that we don't uncharge the new
1862 			 * socket if we couldn't charge it in the first place
1863 			 * as otherwise we uncharge the parent's filter.
1864 			 */
1865 			if (!is_charged)
1866 				RCU_INIT_POINTER(newsk->sk_filter, NULL);
1867 			sk_free_unlock_clone(newsk);
1868 			newsk = NULL;
1869 			goto out;
1870 		}
1871 		RCU_INIT_POINTER(newsk->sk_reuseport_cb, NULL);
1872 
1873 		if (bpf_sk_storage_clone(sk, newsk)) {
1874 			sk_free_unlock_clone(newsk);
1875 			newsk = NULL;
1876 			goto out;
1877 		}
1878 
1879 		/* Clear sk_user_data if parent had the pointer tagged
1880 		 * as not suitable for copying when cloning.
1881 		 */
1882 		if (sk_user_data_is_nocopy(newsk))
1883 			newsk->sk_user_data = NULL;
1884 
1885 		newsk->sk_err	   = 0;
1886 		newsk->sk_err_soft = 0;
1887 		newsk->sk_priority = 0;
1888 		newsk->sk_incoming_cpu = raw_smp_processor_id();
1889 		if (likely(newsk->sk_net_refcnt))
1890 			sock_inuse_add(sock_net(newsk), 1);
1891 
1892 		/*
1893 		 * Before updating sk_refcnt, we must commit prior changes to memory
1894 		 * (Documentation/RCU/rculist_nulls.txt for details)
1895 		 */
1896 		smp_wmb();
1897 		refcount_set(&newsk->sk_refcnt, 2);
1898 
1899 		/*
1900 		 * Increment the counter in the same struct proto as the master
1901 		 * sock (sk_refcnt_debug_inc uses newsk->sk_prot->socks, that
1902 		 * is the same as sk->sk_prot->socks, as this field was copied
1903 		 * with memcpy).
1904 		 *
1905 		 * This _changes_ the previous behaviour, where
1906 		 * tcp_create_openreq_child always was incrementing the
1907 		 * equivalent to tcp_prot->socks (inet_sock_nr), so this have
1908 		 * to be taken into account in all callers. -acme
1909 		 */
1910 		sk_refcnt_debug_inc(newsk);
1911 		sk_set_socket(newsk, NULL);
1912 		RCU_INIT_POINTER(newsk->sk_wq, NULL);
1913 
1914 		if (newsk->sk_prot->sockets_allocated)
1915 			sk_sockets_allocated_inc(newsk);
1916 
1917 		if (sock_needs_netstamp(sk) &&
1918 		    newsk->sk_flags & SK_FLAGS_TIMESTAMP)
1919 			net_enable_timestamp();
1920 	}
1921 out:
1922 	return newsk;
1923 }
1924 EXPORT_SYMBOL_GPL(sk_clone_lock);
1925 
1926 void sk_free_unlock_clone(struct sock *sk)
1927 {
1928 	/* It is still raw copy of parent, so invalidate
1929 	 * destructor and make plain sk_free() */
1930 	sk->sk_destruct = NULL;
1931 	bh_unlock_sock(sk);
1932 	sk_free(sk);
1933 }
1934 EXPORT_SYMBOL_GPL(sk_free_unlock_clone);
1935 
1936 void sk_setup_caps(struct sock *sk, struct dst_entry *dst)
1937 {
1938 	u32 max_segs = 1;
1939 
1940 	sk_dst_set(sk, dst);
1941 	sk->sk_route_caps = dst->dev->features | sk->sk_route_forced_caps;
1942 	if (sk->sk_route_caps & NETIF_F_GSO)
1943 		sk->sk_route_caps |= NETIF_F_GSO_SOFTWARE;
1944 	sk->sk_route_caps &= ~sk->sk_route_nocaps;
1945 	if (sk_can_gso(sk)) {
1946 		if (dst->header_len && !xfrm_dst_offload_ok(dst)) {
1947 			sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
1948 		} else {
1949 			sk->sk_route_caps |= NETIF_F_SG | NETIF_F_HW_CSUM;
1950 			sk->sk_gso_max_size = dst->dev->gso_max_size;
1951 			max_segs = max_t(u32, dst->dev->gso_max_segs, 1);
1952 		}
1953 	}
1954 	sk->sk_gso_max_segs = max_segs;
1955 }
1956 EXPORT_SYMBOL_GPL(sk_setup_caps);
1957 
1958 /*
1959  *	Simple resource managers for sockets.
1960  */
1961 
1962 
1963 /*
1964  * Write buffer destructor automatically called from kfree_skb.
1965  */
1966 void sock_wfree(struct sk_buff *skb)
1967 {
1968 	struct sock *sk = skb->sk;
1969 	unsigned int len = skb->truesize;
1970 
1971 	if (!sock_flag(sk, SOCK_USE_WRITE_QUEUE)) {
1972 		/*
1973 		 * Keep a reference on sk_wmem_alloc, this will be released
1974 		 * after sk_write_space() call
1975 		 */
1976 		WARN_ON(refcount_sub_and_test(len - 1, &sk->sk_wmem_alloc));
1977 		sk->sk_write_space(sk);
1978 		len = 1;
1979 	}
1980 	/*
1981 	 * if sk_wmem_alloc reaches 0, we must finish what sk_free()
1982 	 * could not do because of in-flight packets
1983 	 */
1984 	if (refcount_sub_and_test(len, &sk->sk_wmem_alloc))
1985 		__sk_free(sk);
1986 }
1987 EXPORT_SYMBOL(sock_wfree);
1988 
1989 /* This variant of sock_wfree() is used by TCP,
1990  * since it sets SOCK_USE_WRITE_QUEUE.
1991  */
1992 void __sock_wfree(struct sk_buff *skb)
1993 {
1994 	struct sock *sk = skb->sk;
1995 
1996 	if (refcount_sub_and_test(skb->truesize, &sk->sk_wmem_alloc))
1997 		__sk_free(sk);
1998 }
1999 
2000 void skb_set_owner_w(struct sk_buff *skb, struct sock *sk)
2001 {
2002 	skb_orphan(skb);
2003 	skb->sk = sk;
2004 #ifdef CONFIG_INET
2005 	if (unlikely(!sk_fullsock(sk))) {
2006 		skb->destructor = sock_edemux;
2007 		sock_hold(sk);
2008 		return;
2009 	}
2010 #endif
2011 	skb->destructor = sock_wfree;
2012 	skb_set_hash_from_sk(skb, sk);
2013 	/*
2014 	 * We used to take a refcount on sk, but following operation
2015 	 * is enough to guarantee sk_free() wont free this sock until
2016 	 * all in-flight packets are completed
2017 	 */
2018 	refcount_add(skb->truesize, &sk->sk_wmem_alloc);
2019 }
2020 EXPORT_SYMBOL(skb_set_owner_w);
2021 
2022 static bool can_skb_orphan_partial(const struct sk_buff *skb)
2023 {
2024 #ifdef CONFIG_TLS_DEVICE
2025 	/* Drivers depend on in-order delivery for crypto offload,
2026 	 * partial orphan breaks out-of-order-OK logic.
2027 	 */
2028 	if (skb->decrypted)
2029 		return false;
2030 #endif
2031 	return (skb->destructor == sock_wfree ||
2032 		(IS_ENABLED(CONFIG_INET) && skb->destructor == tcp_wfree));
2033 }
2034 
2035 /* This helper is used by netem, as it can hold packets in its
2036  * delay queue. We want to allow the owner socket to send more
2037  * packets, as if they were already TX completed by a typical driver.
2038  * But we also want to keep skb->sk set because some packet schedulers
2039  * rely on it (sch_fq for example).
2040  */
2041 void skb_orphan_partial(struct sk_buff *skb)
2042 {
2043 	if (skb_is_tcp_pure_ack(skb))
2044 		return;
2045 
2046 	if (can_skb_orphan_partial(skb)) {
2047 		struct sock *sk = skb->sk;
2048 
2049 		if (refcount_inc_not_zero(&sk->sk_refcnt)) {
2050 			WARN_ON(refcount_sub_and_test(skb->truesize, &sk->sk_wmem_alloc));
2051 			skb->destructor = sock_efree;
2052 		}
2053 	} else {
2054 		skb_orphan(skb);
2055 	}
2056 }
2057 EXPORT_SYMBOL(skb_orphan_partial);
2058 
2059 /*
2060  * Read buffer destructor automatically called from kfree_skb.
2061  */
2062 void sock_rfree(struct sk_buff *skb)
2063 {
2064 	struct sock *sk = skb->sk;
2065 	unsigned int len = skb->truesize;
2066 
2067 	atomic_sub(len, &sk->sk_rmem_alloc);
2068 	sk_mem_uncharge(sk, len);
2069 }
2070 EXPORT_SYMBOL(sock_rfree);
2071 
2072 /*
2073  * Buffer destructor for skbs that are not used directly in read or write
2074  * path, e.g. for error handler skbs. Automatically called from kfree_skb.
2075  */
2076 void sock_efree(struct sk_buff *skb)
2077 {
2078 	sock_put(skb->sk);
2079 }
2080 EXPORT_SYMBOL(sock_efree);
2081 
2082 /* Buffer destructor for prefetch/receive path where reference count may
2083  * not be held, e.g. for listen sockets.
2084  */
2085 #ifdef CONFIG_INET
2086 void sock_pfree(struct sk_buff *skb)
2087 {
2088 	if (sk_is_refcounted(skb->sk))
2089 		sock_gen_put(skb->sk);
2090 }
2091 EXPORT_SYMBOL(sock_pfree);
2092 #endif /* CONFIG_INET */
2093 
2094 kuid_t sock_i_uid(struct sock *sk)
2095 {
2096 	kuid_t uid;
2097 
2098 	read_lock_bh(&sk->sk_callback_lock);
2099 	uid = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_uid : GLOBAL_ROOT_UID;
2100 	read_unlock_bh(&sk->sk_callback_lock);
2101 	return uid;
2102 }
2103 EXPORT_SYMBOL(sock_i_uid);
2104 
2105 unsigned long sock_i_ino(struct sock *sk)
2106 {
2107 	unsigned long ino;
2108 
2109 	read_lock_bh(&sk->sk_callback_lock);
2110 	ino = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_ino : 0;
2111 	read_unlock_bh(&sk->sk_callback_lock);
2112 	return ino;
2113 }
2114 EXPORT_SYMBOL(sock_i_ino);
2115 
2116 /*
2117  * Allocate a skb from the socket's send buffer.
2118  */
2119 struct sk_buff *sock_wmalloc(struct sock *sk, unsigned long size, int force,
2120 			     gfp_t priority)
2121 {
2122 	if (force ||
2123 	    refcount_read(&sk->sk_wmem_alloc) < READ_ONCE(sk->sk_sndbuf)) {
2124 		struct sk_buff *skb = alloc_skb(size, priority);
2125 
2126 		if (skb) {
2127 			skb_set_owner_w(skb, sk);
2128 			return skb;
2129 		}
2130 	}
2131 	return NULL;
2132 }
2133 EXPORT_SYMBOL(sock_wmalloc);
2134 
2135 static void sock_ofree(struct sk_buff *skb)
2136 {
2137 	struct sock *sk = skb->sk;
2138 
2139 	atomic_sub(skb->truesize, &sk->sk_omem_alloc);
2140 }
2141 
2142 struct sk_buff *sock_omalloc(struct sock *sk, unsigned long size,
2143 			     gfp_t priority)
2144 {
2145 	struct sk_buff *skb;
2146 
2147 	/* small safe race: SKB_TRUESIZE may differ from final skb->truesize */
2148 	if (atomic_read(&sk->sk_omem_alloc) + SKB_TRUESIZE(size) >
2149 	    sysctl_optmem_max)
2150 		return NULL;
2151 
2152 	skb = alloc_skb(size, priority);
2153 	if (!skb)
2154 		return NULL;
2155 
2156 	atomic_add(skb->truesize, &sk->sk_omem_alloc);
2157 	skb->sk = sk;
2158 	skb->destructor = sock_ofree;
2159 	return skb;
2160 }
2161 
2162 /*
2163  * Allocate a memory block from the socket's option memory buffer.
2164  */
2165 void *sock_kmalloc(struct sock *sk, int size, gfp_t priority)
2166 {
2167 	if ((unsigned int)size <= sysctl_optmem_max &&
2168 	    atomic_read(&sk->sk_omem_alloc) + size < sysctl_optmem_max) {
2169 		void *mem;
2170 		/* First do the add, to avoid the race if kmalloc
2171 		 * might sleep.
2172 		 */
2173 		atomic_add(size, &sk->sk_omem_alloc);
2174 		mem = kmalloc(size, priority);
2175 		if (mem)
2176 			return mem;
2177 		atomic_sub(size, &sk->sk_omem_alloc);
2178 	}
2179 	return NULL;
2180 }
2181 EXPORT_SYMBOL(sock_kmalloc);
2182 
2183 /* Free an option memory block. Note, we actually want the inline
2184  * here as this allows gcc to detect the nullify and fold away the
2185  * condition entirely.
2186  */
2187 static inline void __sock_kfree_s(struct sock *sk, void *mem, int size,
2188 				  const bool nullify)
2189 {
2190 	if (WARN_ON_ONCE(!mem))
2191 		return;
2192 	if (nullify)
2193 		kzfree(mem);
2194 	else
2195 		kfree(mem);
2196 	atomic_sub(size, &sk->sk_omem_alloc);
2197 }
2198 
2199 void sock_kfree_s(struct sock *sk, void *mem, int size)
2200 {
2201 	__sock_kfree_s(sk, mem, size, false);
2202 }
2203 EXPORT_SYMBOL(sock_kfree_s);
2204 
2205 void sock_kzfree_s(struct sock *sk, void *mem, int size)
2206 {
2207 	__sock_kfree_s(sk, mem, size, true);
2208 }
2209 EXPORT_SYMBOL(sock_kzfree_s);
2210 
2211 /* It is almost wait_for_tcp_memory minus release_sock/lock_sock.
2212    I think, these locks should be removed for datagram sockets.
2213  */
2214 static long sock_wait_for_wmem(struct sock *sk, long timeo)
2215 {
2216 	DEFINE_WAIT(wait);
2217 
2218 	sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
2219 	for (;;) {
2220 		if (!timeo)
2221 			break;
2222 		if (signal_pending(current))
2223 			break;
2224 		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
2225 		prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
2226 		if (refcount_read(&sk->sk_wmem_alloc) < READ_ONCE(sk->sk_sndbuf))
2227 			break;
2228 		if (sk->sk_shutdown & SEND_SHUTDOWN)
2229 			break;
2230 		if (sk->sk_err)
2231 			break;
2232 		timeo = schedule_timeout(timeo);
2233 	}
2234 	finish_wait(sk_sleep(sk), &wait);
2235 	return timeo;
2236 }
2237 
2238 
2239 /*
2240  *	Generic send/receive buffer handlers
2241  */
2242 
2243 struct sk_buff *sock_alloc_send_pskb(struct sock *sk, unsigned long header_len,
2244 				     unsigned long data_len, int noblock,
2245 				     int *errcode, int max_page_order)
2246 {
2247 	struct sk_buff *skb;
2248 	long timeo;
2249 	int err;
2250 
2251 	timeo = sock_sndtimeo(sk, noblock);
2252 	for (;;) {
2253 		err = sock_error(sk);
2254 		if (err != 0)
2255 			goto failure;
2256 
2257 		err = -EPIPE;
2258 		if (sk->sk_shutdown & SEND_SHUTDOWN)
2259 			goto failure;
2260 
2261 		if (sk_wmem_alloc_get(sk) < READ_ONCE(sk->sk_sndbuf))
2262 			break;
2263 
2264 		sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
2265 		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
2266 		err = -EAGAIN;
2267 		if (!timeo)
2268 			goto failure;
2269 		if (signal_pending(current))
2270 			goto interrupted;
2271 		timeo = sock_wait_for_wmem(sk, timeo);
2272 	}
2273 	skb = alloc_skb_with_frags(header_len, data_len, max_page_order,
2274 				   errcode, sk->sk_allocation);
2275 	if (skb)
2276 		skb_set_owner_w(skb, sk);
2277 	return skb;
2278 
2279 interrupted:
2280 	err = sock_intr_errno(timeo);
2281 failure:
2282 	*errcode = err;
2283 	return NULL;
2284 }
2285 EXPORT_SYMBOL(sock_alloc_send_pskb);
2286 
2287 struct sk_buff *sock_alloc_send_skb(struct sock *sk, unsigned long size,
2288 				    int noblock, int *errcode)
2289 {
2290 	return sock_alloc_send_pskb(sk, size, 0, noblock, errcode, 0);
2291 }
2292 EXPORT_SYMBOL(sock_alloc_send_skb);
2293 
2294 int __sock_cmsg_send(struct sock *sk, struct msghdr *msg, struct cmsghdr *cmsg,
2295 		     struct sockcm_cookie *sockc)
2296 {
2297 	u32 tsflags;
2298 
2299 	switch (cmsg->cmsg_type) {
2300 	case SO_MARK:
2301 		if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
2302 			return -EPERM;
2303 		if (cmsg->cmsg_len != CMSG_LEN(sizeof(u32)))
2304 			return -EINVAL;
2305 		sockc->mark = *(u32 *)CMSG_DATA(cmsg);
2306 		break;
2307 	case SO_TIMESTAMPING_OLD:
2308 		if (cmsg->cmsg_len != CMSG_LEN(sizeof(u32)))
2309 			return -EINVAL;
2310 
2311 		tsflags = *(u32 *)CMSG_DATA(cmsg);
2312 		if (tsflags & ~SOF_TIMESTAMPING_TX_RECORD_MASK)
2313 			return -EINVAL;
2314 
2315 		sockc->tsflags &= ~SOF_TIMESTAMPING_TX_RECORD_MASK;
2316 		sockc->tsflags |= tsflags;
2317 		break;
2318 	case SCM_TXTIME:
2319 		if (!sock_flag(sk, SOCK_TXTIME))
2320 			return -EINVAL;
2321 		if (cmsg->cmsg_len != CMSG_LEN(sizeof(u64)))
2322 			return -EINVAL;
2323 		sockc->transmit_time = get_unaligned((u64 *)CMSG_DATA(cmsg));
2324 		break;
2325 	/* SCM_RIGHTS and SCM_CREDENTIALS are semantically in SOL_UNIX. */
2326 	case SCM_RIGHTS:
2327 	case SCM_CREDENTIALS:
2328 		break;
2329 	default:
2330 		return -EINVAL;
2331 	}
2332 	return 0;
2333 }
2334 EXPORT_SYMBOL(__sock_cmsg_send);
2335 
2336 int sock_cmsg_send(struct sock *sk, struct msghdr *msg,
2337 		   struct sockcm_cookie *sockc)
2338 {
2339 	struct cmsghdr *cmsg;
2340 	int ret;
2341 
2342 	for_each_cmsghdr(cmsg, msg) {
2343 		if (!CMSG_OK(msg, cmsg))
2344 			return -EINVAL;
2345 		if (cmsg->cmsg_level != SOL_SOCKET)
2346 			continue;
2347 		ret = __sock_cmsg_send(sk, msg, cmsg, sockc);
2348 		if (ret)
2349 			return ret;
2350 	}
2351 	return 0;
2352 }
2353 EXPORT_SYMBOL(sock_cmsg_send);
2354 
2355 static void sk_enter_memory_pressure(struct sock *sk)
2356 {
2357 	if (!sk->sk_prot->enter_memory_pressure)
2358 		return;
2359 
2360 	sk->sk_prot->enter_memory_pressure(sk);
2361 }
2362 
2363 static void sk_leave_memory_pressure(struct sock *sk)
2364 {
2365 	if (sk->sk_prot->leave_memory_pressure) {
2366 		sk->sk_prot->leave_memory_pressure(sk);
2367 	} else {
2368 		unsigned long *memory_pressure = sk->sk_prot->memory_pressure;
2369 
2370 		if (memory_pressure && READ_ONCE(*memory_pressure))
2371 			WRITE_ONCE(*memory_pressure, 0);
2372 	}
2373 }
2374 
2375 #define SKB_FRAG_PAGE_ORDER	get_order(32768)
2376 DEFINE_STATIC_KEY_FALSE(net_high_order_alloc_disable_key);
2377 
2378 /**
2379  * skb_page_frag_refill - check that a page_frag contains enough room
2380  * @sz: minimum size of the fragment we want to get
2381  * @pfrag: pointer to page_frag
2382  * @gfp: priority for memory allocation
2383  *
2384  * Note: While this allocator tries to use high order pages, there is
2385  * no guarantee that allocations succeed. Therefore, @sz MUST be
2386  * less or equal than PAGE_SIZE.
2387  */
2388 bool skb_page_frag_refill(unsigned int sz, struct page_frag *pfrag, gfp_t gfp)
2389 {
2390 	if (pfrag->page) {
2391 		if (page_ref_count(pfrag->page) == 1) {
2392 			pfrag->offset = 0;
2393 			return true;
2394 		}
2395 		if (pfrag->offset + sz <= pfrag->size)
2396 			return true;
2397 		put_page(pfrag->page);
2398 	}
2399 
2400 	pfrag->offset = 0;
2401 	if (SKB_FRAG_PAGE_ORDER &&
2402 	    !static_branch_unlikely(&net_high_order_alloc_disable_key)) {
2403 		/* Avoid direct reclaim but allow kswapd to wake */
2404 		pfrag->page = alloc_pages((gfp & ~__GFP_DIRECT_RECLAIM) |
2405 					  __GFP_COMP | __GFP_NOWARN |
2406 					  __GFP_NORETRY,
2407 					  SKB_FRAG_PAGE_ORDER);
2408 		if (likely(pfrag->page)) {
2409 			pfrag->size = PAGE_SIZE << SKB_FRAG_PAGE_ORDER;
2410 			return true;
2411 		}
2412 	}
2413 	pfrag->page = alloc_page(gfp);
2414 	if (likely(pfrag->page)) {
2415 		pfrag->size = PAGE_SIZE;
2416 		return true;
2417 	}
2418 	return false;
2419 }
2420 EXPORT_SYMBOL(skb_page_frag_refill);
2421 
2422 bool sk_page_frag_refill(struct sock *sk, struct page_frag *pfrag)
2423 {
2424 	if (likely(skb_page_frag_refill(32U, pfrag, sk->sk_allocation)))
2425 		return true;
2426 
2427 	sk_enter_memory_pressure(sk);
2428 	sk_stream_moderate_sndbuf(sk);
2429 	return false;
2430 }
2431 EXPORT_SYMBOL(sk_page_frag_refill);
2432 
2433 static void __lock_sock(struct sock *sk)
2434 	__releases(&sk->sk_lock.slock)
2435 	__acquires(&sk->sk_lock.slock)
2436 {
2437 	DEFINE_WAIT(wait);
2438 
2439 	for (;;) {
2440 		prepare_to_wait_exclusive(&sk->sk_lock.wq, &wait,
2441 					TASK_UNINTERRUPTIBLE);
2442 		spin_unlock_bh(&sk->sk_lock.slock);
2443 		schedule();
2444 		spin_lock_bh(&sk->sk_lock.slock);
2445 		if (!sock_owned_by_user(sk))
2446 			break;
2447 	}
2448 	finish_wait(&sk->sk_lock.wq, &wait);
2449 }
2450 
2451 void __release_sock(struct sock *sk)
2452 	__releases(&sk->sk_lock.slock)
2453 	__acquires(&sk->sk_lock.slock)
2454 {
2455 	struct sk_buff *skb, *next;
2456 
2457 	while ((skb = sk->sk_backlog.head) != NULL) {
2458 		sk->sk_backlog.head = sk->sk_backlog.tail = NULL;
2459 
2460 		spin_unlock_bh(&sk->sk_lock.slock);
2461 
2462 		do {
2463 			next = skb->next;
2464 			prefetch(next);
2465 			WARN_ON_ONCE(skb_dst_is_noref(skb));
2466 			skb_mark_not_on_list(skb);
2467 			sk_backlog_rcv(sk, skb);
2468 
2469 			cond_resched();
2470 
2471 			skb = next;
2472 		} while (skb != NULL);
2473 
2474 		spin_lock_bh(&sk->sk_lock.slock);
2475 	}
2476 
2477 	/*
2478 	 * Doing the zeroing here guarantee we can not loop forever
2479 	 * while a wild producer attempts to flood us.
2480 	 */
2481 	sk->sk_backlog.len = 0;
2482 }
2483 
2484 void __sk_flush_backlog(struct sock *sk)
2485 {
2486 	spin_lock_bh(&sk->sk_lock.slock);
2487 	__release_sock(sk);
2488 	spin_unlock_bh(&sk->sk_lock.slock);
2489 }
2490 
2491 /**
2492  * sk_wait_data - wait for data to arrive at sk_receive_queue
2493  * @sk:    sock to wait on
2494  * @timeo: for how long
2495  * @skb:   last skb seen on sk_receive_queue
2496  *
2497  * Now socket state including sk->sk_err is changed only under lock,
2498  * hence we may omit checks after joining wait queue.
2499  * We check receive queue before schedule() only as optimization;
2500  * it is very likely that release_sock() added new data.
2501  */
2502 int sk_wait_data(struct sock *sk, long *timeo, const struct sk_buff *skb)
2503 {
2504 	DEFINE_WAIT_FUNC(wait, woken_wake_function);
2505 	int rc;
2506 
2507 	add_wait_queue(sk_sleep(sk), &wait);
2508 	sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
2509 	rc = sk_wait_event(sk, timeo, skb_peek_tail(&sk->sk_receive_queue) != skb, &wait);
2510 	sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
2511 	remove_wait_queue(sk_sleep(sk), &wait);
2512 	return rc;
2513 }
2514 EXPORT_SYMBOL(sk_wait_data);
2515 
2516 /**
2517  *	__sk_mem_raise_allocated - increase memory_allocated
2518  *	@sk: socket
2519  *	@size: memory size to allocate
2520  *	@amt: pages to allocate
2521  *	@kind: allocation type
2522  *
2523  *	Similar to __sk_mem_schedule(), but does not update sk_forward_alloc
2524  */
2525 int __sk_mem_raise_allocated(struct sock *sk, int size, int amt, int kind)
2526 {
2527 	struct proto *prot = sk->sk_prot;
2528 	long allocated = sk_memory_allocated_add(sk, amt);
2529 	bool charged = true;
2530 
2531 	if (mem_cgroup_sockets_enabled && sk->sk_memcg &&
2532 	    !(charged = mem_cgroup_charge_skmem(sk->sk_memcg, amt)))
2533 		goto suppress_allocation;
2534 
2535 	/* Under limit. */
2536 	if (allocated <= sk_prot_mem_limits(sk, 0)) {
2537 		sk_leave_memory_pressure(sk);
2538 		return 1;
2539 	}
2540 
2541 	/* Under pressure. */
2542 	if (allocated > sk_prot_mem_limits(sk, 1))
2543 		sk_enter_memory_pressure(sk);
2544 
2545 	/* Over hard limit. */
2546 	if (allocated > sk_prot_mem_limits(sk, 2))
2547 		goto suppress_allocation;
2548 
2549 	/* guarantee minimum buffer size under pressure */
2550 	if (kind == SK_MEM_RECV) {
2551 		if (atomic_read(&sk->sk_rmem_alloc) < sk_get_rmem0(sk, prot))
2552 			return 1;
2553 
2554 	} else { /* SK_MEM_SEND */
2555 		int wmem0 = sk_get_wmem0(sk, prot);
2556 
2557 		if (sk->sk_type == SOCK_STREAM) {
2558 			if (sk->sk_wmem_queued < wmem0)
2559 				return 1;
2560 		} else if (refcount_read(&sk->sk_wmem_alloc) < wmem0) {
2561 				return 1;
2562 		}
2563 	}
2564 
2565 	if (sk_has_memory_pressure(sk)) {
2566 		u64 alloc;
2567 
2568 		if (!sk_under_memory_pressure(sk))
2569 			return 1;
2570 		alloc = sk_sockets_allocated_read_positive(sk);
2571 		if (sk_prot_mem_limits(sk, 2) > alloc *
2572 		    sk_mem_pages(sk->sk_wmem_queued +
2573 				 atomic_read(&sk->sk_rmem_alloc) +
2574 				 sk->sk_forward_alloc))
2575 			return 1;
2576 	}
2577 
2578 suppress_allocation:
2579 
2580 	if (kind == SK_MEM_SEND && sk->sk_type == SOCK_STREAM) {
2581 		sk_stream_moderate_sndbuf(sk);
2582 
2583 		/* Fail only if socket is _under_ its sndbuf.
2584 		 * In this case we cannot block, so that we have to fail.
2585 		 */
2586 		if (sk->sk_wmem_queued + size >= sk->sk_sndbuf)
2587 			return 1;
2588 	}
2589 
2590 	if (kind == SK_MEM_SEND || (kind == SK_MEM_RECV && charged))
2591 		trace_sock_exceed_buf_limit(sk, prot, allocated, kind);
2592 
2593 	sk_memory_allocated_sub(sk, amt);
2594 
2595 	if (mem_cgroup_sockets_enabled && sk->sk_memcg)
2596 		mem_cgroup_uncharge_skmem(sk->sk_memcg, amt);
2597 
2598 	return 0;
2599 }
2600 EXPORT_SYMBOL(__sk_mem_raise_allocated);
2601 
2602 /**
2603  *	__sk_mem_schedule - increase sk_forward_alloc and memory_allocated
2604  *	@sk: socket
2605  *	@size: memory size to allocate
2606  *	@kind: allocation type
2607  *
2608  *	If kind is SK_MEM_SEND, it means wmem allocation. Otherwise it means
2609  *	rmem allocation. This function assumes that protocols which have
2610  *	memory_pressure use sk_wmem_queued as write buffer accounting.
2611  */
2612 int __sk_mem_schedule(struct sock *sk, int size, int kind)
2613 {
2614 	int ret, amt = sk_mem_pages(size);
2615 
2616 	sk->sk_forward_alloc += amt << SK_MEM_QUANTUM_SHIFT;
2617 	ret = __sk_mem_raise_allocated(sk, size, amt, kind);
2618 	if (!ret)
2619 		sk->sk_forward_alloc -= amt << SK_MEM_QUANTUM_SHIFT;
2620 	return ret;
2621 }
2622 EXPORT_SYMBOL(__sk_mem_schedule);
2623 
2624 /**
2625  *	__sk_mem_reduce_allocated - reclaim memory_allocated
2626  *	@sk: socket
2627  *	@amount: number of quanta
2628  *
2629  *	Similar to __sk_mem_reclaim(), but does not update sk_forward_alloc
2630  */
2631 void __sk_mem_reduce_allocated(struct sock *sk, int amount)
2632 {
2633 	sk_memory_allocated_sub(sk, amount);
2634 
2635 	if (mem_cgroup_sockets_enabled && sk->sk_memcg)
2636 		mem_cgroup_uncharge_skmem(sk->sk_memcg, amount);
2637 
2638 	if (sk_under_memory_pressure(sk) &&
2639 	    (sk_memory_allocated(sk) < sk_prot_mem_limits(sk, 0)))
2640 		sk_leave_memory_pressure(sk);
2641 }
2642 EXPORT_SYMBOL(__sk_mem_reduce_allocated);
2643 
2644 /**
2645  *	__sk_mem_reclaim - reclaim sk_forward_alloc and memory_allocated
2646  *	@sk: socket
2647  *	@amount: number of bytes (rounded down to a SK_MEM_QUANTUM multiple)
2648  */
2649 void __sk_mem_reclaim(struct sock *sk, int amount)
2650 {
2651 	amount >>= SK_MEM_QUANTUM_SHIFT;
2652 	sk->sk_forward_alloc -= amount << SK_MEM_QUANTUM_SHIFT;
2653 	__sk_mem_reduce_allocated(sk, amount);
2654 }
2655 EXPORT_SYMBOL(__sk_mem_reclaim);
2656 
2657 int sk_set_peek_off(struct sock *sk, int val)
2658 {
2659 	sk->sk_peek_off = val;
2660 	return 0;
2661 }
2662 EXPORT_SYMBOL_GPL(sk_set_peek_off);
2663 
2664 /*
2665  * Set of default routines for initialising struct proto_ops when
2666  * the protocol does not support a particular function. In certain
2667  * cases where it makes no sense for a protocol to have a "do nothing"
2668  * function, some default processing is provided.
2669  */
2670 
2671 int sock_no_bind(struct socket *sock, struct sockaddr *saddr, int len)
2672 {
2673 	return -EOPNOTSUPP;
2674 }
2675 EXPORT_SYMBOL(sock_no_bind);
2676 
2677 int sock_no_connect(struct socket *sock, struct sockaddr *saddr,
2678 		    int len, int flags)
2679 {
2680 	return -EOPNOTSUPP;
2681 }
2682 EXPORT_SYMBOL(sock_no_connect);
2683 
2684 int sock_no_socketpair(struct socket *sock1, struct socket *sock2)
2685 {
2686 	return -EOPNOTSUPP;
2687 }
2688 EXPORT_SYMBOL(sock_no_socketpair);
2689 
2690 int sock_no_accept(struct socket *sock, struct socket *newsock, int flags,
2691 		   bool kern)
2692 {
2693 	return -EOPNOTSUPP;
2694 }
2695 EXPORT_SYMBOL(sock_no_accept);
2696 
2697 int sock_no_getname(struct socket *sock, struct sockaddr *saddr,
2698 		    int peer)
2699 {
2700 	return -EOPNOTSUPP;
2701 }
2702 EXPORT_SYMBOL(sock_no_getname);
2703 
2704 int sock_no_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
2705 {
2706 	return -EOPNOTSUPP;
2707 }
2708 EXPORT_SYMBOL(sock_no_ioctl);
2709 
2710 int sock_no_listen(struct socket *sock, int backlog)
2711 {
2712 	return -EOPNOTSUPP;
2713 }
2714 EXPORT_SYMBOL(sock_no_listen);
2715 
2716 int sock_no_shutdown(struct socket *sock, int how)
2717 {
2718 	return -EOPNOTSUPP;
2719 }
2720 EXPORT_SYMBOL(sock_no_shutdown);
2721 
2722 int sock_no_setsockopt(struct socket *sock, int level, int optname,
2723 		    char __user *optval, unsigned int optlen)
2724 {
2725 	return -EOPNOTSUPP;
2726 }
2727 EXPORT_SYMBOL(sock_no_setsockopt);
2728 
2729 int sock_no_getsockopt(struct socket *sock, int level, int optname,
2730 		    char __user *optval, int __user *optlen)
2731 {
2732 	return -EOPNOTSUPP;
2733 }
2734 EXPORT_SYMBOL(sock_no_getsockopt);
2735 
2736 int sock_no_sendmsg(struct socket *sock, struct msghdr *m, size_t len)
2737 {
2738 	return -EOPNOTSUPP;
2739 }
2740 EXPORT_SYMBOL(sock_no_sendmsg);
2741 
2742 int sock_no_sendmsg_locked(struct sock *sk, struct msghdr *m, size_t len)
2743 {
2744 	return -EOPNOTSUPP;
2745 }
2746 EXPORT_SYMBOL(sock_no_sendmsg_locked);
2747 
2748 int sock_no_recvmsg(struct socket *sock, struct msghdr *m, size_t len,
2749 		    int flags)
2750 {
2751 	return -EOPNOTSUPP;
2752 }
2753 EXPORT_SYMBOL(sock_no_recvmsg);
2754 
2755 int sock_no_mmap(struct file *file, struct socket *sock, struct vm_area_struct *vma)
2756 {
2757 	/* Mirror missing mmap method error code */
2758 	return -ENODEV;
2759 }
2760 EXPORT_SYMBOL(sock_no_mmap);
2761 
2762 ssize_t sock_no_sendpage(struct socket *sock, struct page *page, int offset, size_t size, int flags)
2763 {
2764 	ssize_t res;
2765 	struct msghdr msg = {.msg_flags = flags};
2766 	struct kvec iov;
2767 	char *kaddr = kmap(page);
2768 	iov.iov_base = kaddr + offset;
2769 	iov.iov_len = size;
2770 	res = kernel_sendmsg(sock, &msg, &iov, 1, size);
2771 	kunmap(page);
2772 	return res;
2773 }
2774 EXPORT_SYMBOL(sock_no_sendpage);
2775 
2776 ssize_t sock_no_sendpage_locked(struct sock *sk, struct page *page,
2777 				int offset, size_t size, int flags)
2778 {
2779 	ssize_t res;
2780 	struct msghdr msg = {.msg_flags = flags};
2781 	struct kvec iov;
2782 	char *kaddr = kmap(page);
2783 
2784 	iov.iov_base = kaddr + offset;
2785 	iov.iov_len = size;
2786 	res = kernel_sendmsg_locked(sk, &msg, &iov, 1, size);
2787 	kunmap(page);
2788 	return res;
2789 }
2790 EXPORT_SYMBOL(sock_no_sendpage_locked);
2791 
2792 /*
2793  *	Default Socket Callbacks
2794  */
2795 
2796 static void sock_def_wakeup(struct sock *sk)
2797 {
2798 	struct socket_wq *wq;
2799 
2800 	rcu_read_lock();
2801 	wq = rcu_dereference(sk->sk_wq);
2802 	if (skwq_has_sleeper(wq))
2803 		wake_up_interruptible_all(&wq->wait);
2804 	rcu_read_unlock();
2805 }
2806 
2807 static void sock_def_error_report(struct sock *sk)
2808 {
2809 	struct socket_wq *wq;
2810 
2811 	rcu_read_lock();
2812 	wq = rcu_dereference(sk->sk_wq);
2813 	if (skwq_has_sleeper(wq))
2814 		wake_up_interruptible_poll(&wq->wait, EPOLLERR);
2815 	sk_wake_async(sk, SOCK_WAKE_IO, POLL_ERR);
2816 	rcu_read_unlock();
2817 }
2818 
2819 void sock_def_readable(struct sock *sk)
2820 {
2821 	struct socket_wq *wq;
2822 
2823 	rcu_read_lock();
2824 	wq = rcu_dereference(sk->sk_wq);
2825 	if (skwq_has_sleeper(wq))
2826 		wake_up_interruptible_sync_poll(&wq->wait, EPOLLIN | EPOLLPRI |
2827 						EPOLLRDNORM | EPOLLRDBAND);
2828 	sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
2829 	rcu_read_unlock();
2830 }
2831 
2832 static void sock_def_write_space(struct sock *sk)
2833 {
2834 	struct socket_wq *wq;
2835 
2836 	rcu_read_lock();
2837 
2838 	/* Do not wake up a writer until he can make "significant"
2839 	 * progress.  --DaveM
2840 	 */
2841 	if ((refcount_read(&sk->sk_wmem_alloc) << 1) <= READ_ONCE(sk->sk_sndbuf)) {
2842 		wq = rcu_dereference(sk->sk_wq);
2843 		if (skwq_has_sleeper(wq))
2844 			wake_up_interruptible_sync_poll(&wq->wait, EPOLLOUT |
2845 						EPOLLWRNORM | EPOLLWRBAND);
2846 
2847 		/* Should agree with poll, otherwise some programs break */
2848 		if (sock_writeable(sk))
2849 			sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
2850 	}
2851 
2852 	rcu_read_unlock();
2853 }
2854 
2855 static void sock_def_destruct(struct sock *sk)
2856 {
2857 }
2858 
2859 void sk_send_sigurg(struct sock *sk)
2860 {
2861 	if (sk->sk_socket && sk->sk_socket->file)
2862 		if (send_sigurg(&sk->sk_socket->file->f_owner))
2863 			sk_wake_async(sk, SOCK_WAKE_URG, POLL_PRI);
2864 }
2865 EXPORT_SYMBOL(sk_send_sigurg);
2866 
2867 void sk_reset_timer(struct sock *sk, struct timer_list* timer,
2868 		    unsigned long expires)
2869 {
2870 	if (!mod_timer(timer, expires))
2871 		sock_hold(sk);
2872 }
2873 EXPORT_SYMBOL(sk_reset_timer);
2874 
2875 void sk_stop_timer(struct sock *sk, struct timer_list* timer)
2876 {
2877 	if (del_timer(timer))
2878 		__sock_put(sk);
2879 }
2880 EXPORT_SYMBOL(sk_stop_timer);
2881 
2882 void sock_init_data(struct socket *sock, struct sock *sk)
2883 {
2884 	sk_init_common(sk);
2885 	sk->sk_send_head	=	NULL;
2886 
2887 	timer_setup(&sk->sk_timer, NULL, 0);
2888 
2889 	sk->sk_allocation	=	GFP_KERNEL;
2890 	sk->sk_rcvbuf		=	sysctl_rmem_default;
2891 	sk->sk_sndbuf		=	sysctl_wmem_default;
2892 	sk->sk_state		=	TCP_CLOSE;
2893 	sk_set_socket(sk, sock);
2894 
2895 	sock_set_flag(sk, SOCK_ZAPPED);
2896 
2897 	if (sock) {
2898 		sk->sk_type	=	sock->type;
2899 		RCU_INIT_POINTER(sk->sk_wq, &sock->wq);
2900 		sock->sk	=	sk;
2901 		sk->sk_uid	=	SOCK_INODE(sock)->i_uid;
2902 	} else {
2903 		RCU_INIT_POINTER(sk->sk_wq, NULL);
2904 		sk->sk_uid	=	make_kuid(sock_net(sk)->user_ns, 0);
2905 	}
2906 
2907 	rwlock_init(&sk->sk_callback_lock);
2908 	if (sk->sk_kern_sock)
2909 		lockdep_set_class_and_name(
2910 			&sk->sk_callback_lock,
2911 			af_kern_callback_keys + sk->sk_family,
2912 			af_family_kern_clock_key_strings[sk->sk_family]);
2913 	else
2914 		lockdep_set_class_and_name(
2915 			&sk->sk_callback_lock,
2916 			af_callback_keys + sk->sk_family,
2917 			af_family_clock_key_strings[sk->sk_family]);
2918 
2919 	sk->sk_state_change	=	sock_def_wakeup;
2920 	sk->sk_data_ready	=	sock_def_readable;
2921 	sk->sk_write_space	=	sock_def_write_space;
2922 	sk->sk_error_report	=	sock_def_error_report;
2923 	sk->sk_destruct		=	sock_def_destruct;
2924 
2925 	sk->sk_frag.page	=	NULL;
2926 	sk->sk_frag.offset	=	0;
2927 	sk->sk_peek_off		=	-1;
2928 
2929 	sk->sk_peer_pid 	=	NULL;
2930 	sk->sk_peer_cred	=	NULL;
2931 	sk->sk_write_pending	=	0;
2932 	sk->sk_rcvlowat		=	1;
2933 	sk->sk_rcvtimeo		=	MAX_SCHEDULE_TIMEOUT;
2934 	sk->sk_sndtimeo		=	MAX_SCHEDULE_TIMEOUT;
2935 
2936 	sk->sk_stamp = SK_DEFAULT_STAMP;
2937 #if BITS_PER_LONG==32
2938 	seqlock_init(&sk->sk_stamp_seq);
2939 #endif
2940 	atomic_set(&sk->sk_zckey, 0);
2941 
2942 #ifdef CONFIG_NET_RX_BUSY_POLL
2943 	sk->sk_napi_id		=	0;
2944 	sk->sk_ll_usec		=	sysctl_net_busy_read;
2945 #endif
2946 
2947 	sk->sk_max_pacing_rate = ~0UL;
2948 	sk->sk_pacing_rate = ~0UL;
2949 	WRITE_ONCE(sk->sk_pacing_shift, 10);
2950 	sk->sk_incoming_cpu = -1;
2951 
2952 	sk_rx_queue_clear(sk);
2953 	/*
2954 	 * Before updating sk_refcnt, we must commit prior changes to memory
2955 	 * (Documentation/RCU/rculist_nulls.txt for details)
2956 	 */
2957 	smp_wmb();
2958 	refcount_set(&sk->sk_refcnt, 1);
2959 	atomic_set(&sk->sk_drops, 0);
2960 }
2961 EXPORT_SYMBOL(sock_init_data);
2962 
2963 void lock_sock_nested(struct sock *sk, int subclass)
2964 {
2965 	might_sleep();
2966 	spin_lock_bh(&sk->sk_lock.slock);
2967 	if (sk->sk_lock.owned)
2968 		__lock_sock(sk);
2969 	sk->sk_lock.owned = 1;
2970 	spin_unlock(&sk->sk_lock.slock);
2971 	/*
2972 	 * The sk_lock has mutex_lock() semantics here:
2973 	 */
2974 	mutex_acquire(&sk->sk_lock.dep_map, subclass, 0, _RET_IP_);
2975 	local_bh_enable();
2976 }
2977 EXPORT_SYMBOL(lock_sock_nested);
2978 
2979 void release_sock(struct sock *sk)
2980 {
2981 	spin_lock_bh(&sk->sk_lock.slock);
2982 	if (sk->sk_backlog.tail)
2983 		__release_sock(sk);
2984 
2985 	/* Warning : release_cb() might need to release sk ownership,
2986 	 * ie call sock_release_ownership(sk) before us.
2987 	 */
2988 	if (sk->sk_prot->release_cb)
2989 		sk->sk_prot->release_cb(sk);
2990 
2991 	sock_release_ownership(sk);
2992 	if (waitqueue_active(&sk->sk_lock.wq))
2993 		wake_up(&sk->sk_lock.wq);
2994 	spin_unlock_bh(&sk->sk_lock.slock);
2995 }
2996 EXPORT_SYMBOL(release_sock);
2997 
2998 /**
2999  * lock_sock_fast - fast version of lock_sock
3000  * @sk: socket
3001  *
3002  * This version should be used for very small section, where process wont block
3003  * return false if fast path is taken:
3004  *
3005  *   sk_lock.slock locked, owned = 0, BH disabled
3006  *
3007  * return true if slow path is taken:
3008  *
3009  *   sk_lock.slock unlocked, owned = 1, BH enabled
3010  */
3011 bool lock_sock_fast(struct sock *sk)
3012 {
3013 	might_sleep();
3014 	spin_lock_bh(&sk->sk_lock.slock);
3015 
3016 	if (!sk->sk_lock.owned)
3017 		/*
3018 		 * Note : We must disable BH
3019 		 */
3020 		return false;
3021 
3022 	__lock_sock(sk);
3023 	sk->sk_lock.owned = 1;
3024 	spin_unlock(&sk->sk_lock.slock);
3025 	/*
3026 	 * The sk_lock has mutex_lock() semantics here:
3027 	 */
3028 	mutex_acquire(&sk->sk_lock.dep_map, 0, 0, _RET_IP_);
3029 	local_bh_enable();
3030 	return true;
3031 }
3032 EXPORT_SYMBOL(lock_sock_fast);
3033 
3034 int sock_gettstamp(struct socket *sock, void __user *userstamp,
3035 		   bool timeval, bool time32)
3036 {
3037 	struct sock *sk = sock->sk;
3038 	struct timespec64 ts;
3039 
3040 	sock_enable_timestamp(sk, SOCK_TIMESTAMP);
3041 	ts = ktime_to_timespec64(sock_read_timestamp(sk));
3042 	if (ts.tv_sec == -1)
3043 		return -ENOENT;
3044 	if (ts.tv_sec == 0) {
3045 		ktime_t kt = ktime_get_real();
3046 		sock_write_timestamp(sk, kt);
3047 		ts = ktime_to_timespec64(kt);
3048 	}
3049 
3050 	if (timeval)
3051 		ts.tv_nsec /= 1000;
3052 
3053 #ifdef CONFIG_COMPAT_32BIT_TIME
3054 	if (time32)
3055 		return put_old_timespec32(&ts, userstamp);
3056 #endif
3057 #ifdef CONFIG_SPARC64
3058 	/* beware of padding in sparc64 timeval */
3059 	if (timeval && !in_compat_syscall()) {
3060 		struct __kernel_old_timeval __user tv = {
3061 			.tv_sec = ts.tv_sec,
3062 			.tv_usec = ts.tv_nsec,
3063 		};
3064 		if (copy_to_user(userstamp, &tv, sizeof(tv)))
3065 			return -EFAULT;
3066 		return 0;
3067 	}
3068 #endif
3069 	return put_timespec64(&ts, userstamp);
3070 }
3071 EXPORT_SYMBOL(sock_gettstamp);
3072 
3073 void sock_enable_timestamp(struct sock *sk, enum sock_flags flag)
3074 {
3075 	if (!sock_flag(sk, flag)) {
3076 		unsigned long previous_flags = sk->sk_flags;
3077 
3078 		sock_set_flag(sk, flag);
3079 		/*
3080 		 * we just set one of the two flags which require net
3081 		 * time stamping, but time stamping might have been on
3082 		 * already because of the other one
3083 		 */
3084 		if (sock_needs_netstamp(sk) &&
3085 		    !(previous_flags & SK_FLAGS_TIMESTAMP))
3086 			net_enable_timestamp();
3087 	}
3088 }
3089 
3090 int sock_recv_errqueue(struct sock *sk, struct msghdr *msg, int len,
3091 		       int level, int type)
3092 {
3093 	struct sock_exterr_skb *serr;
3094 	struct sk_buff *skb;
3095 	int copied, err;
3096 
3097 	err = -EAGAIN;
3098 	skb = sock_dequeue_err_skb(sk);
3099 	if (skb == NULL)
3100 		goto out;
3101 
3102 	copied = skb->len;
3103 	if (copied > len) {
3104 		msg->msg_flags |= MSG_TRUNC;
3105 		copied = len;
3106 	}
3107 	err = skb_copy_datagram_msg(skb, 0, msg, copied);
3108 	if (err)
3109 		goto out_free_skb;
3110 
3111 	sock_recv_timestamp(msg, sk, skb);
3112 
3113 	serr = SKB_EXT_ERR(skb);
3114 	put_cmsg(msg, level, type, sizeof(serr->ee), &serr->ee);
3115 
3116 	msg->msg_flags |= MSG_ERRQUEUE;
3117 	err = copied;
3118 
3119 out_free_skb:
3120 	kfree_skb(skb);
3121 out:
3122 	return err;
3123 }
3124 EXPORT_SYMBOL(sock_recv_errqueue);
3125 
3126 /*
3127  *	Get a socket option on an socket.
3128  *
3129  *	FIX: POSIX 1003.1g is very ambiguous here. It states that
3130  *	asynchronous errors should be reported by getsockopt. We assume
3131  *	this means if you specify SO_ERROR (otherwise whats the point of it).
3132  */
3133 int sock_common_getsockopt(struct socket *sock, int level, int optname,
3134 			   char __user *optval, int __user *optlen)
3135 {
3136 	struct sock *sk = sock->sk;
3137 
3138 	return sk->sk_prot->getsockopt(sk, level, optname, optval, optlen);
3139 }
3140 EXPORT_SYMBOL(sock_common_getsockopt);
3141 
3142 #ifdef CONFIG_COMPAT
3143 int compat_sock_common_getsockopt(struct socket *sock, int level, int optname,
3144 				  char __user *optval, int __user *optlen)
3145 {
3146 	struct sock *sk = sock->sk;
3147 
3148 	if (sk->sk_prot->compat_getsockopt != NULL)
3149 		return sk->sk_prot->compat_getsockopt(sk, level, optname,
3150 						      optval, optlen);
3151 	return sk->sk_prot->getsockopt(sk, level, optname, optval, optlen);
3152 }
3153 EXPORT_SYMBOL(compat_sock_common_getsockopt);
3154 #endif
3155 
3156 int sock_common_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
3157 			int flags)
3158 {
3159 	struct sock *sk = sock->sk;
3160 	int addr_len = 0;
3161 	int err;
3162 
3163 	err = sk->sk_prot->recvmsg(sk, msg, size, flags & MSG_DONTWAIT,
3164 				   flags & ~MSG_DONTWAIT, &addr_len);
3165 	if (err >= 0)
3166 		msg->msg_namelen = addr_len;
3167 	return err;
3168 }
3169 EXPORT_SYMBOL(sock_common_recvmsg);
3170 
3171 /*
3172  *	Set socket options on an inet socket.
3173  */
3174 int sock_common_setsockopt(struct socket *sock, int level, int optname,
3175 			   char __user *optval, unsigned int optlen)
3176 {
3177 	struct sock *sk = sock->sk;
3178 
3179 	return sk->sk_prot->setsockopt(sk, level, optname, optval, optlen);
3180 }
3181 EXPORT_SYMBOL(sock_common_setsockopt);
3182 
3183 #ifdef CONFIG_COMPAT
3184 int compat_sock_common_setsockopt(struct socket *sock, int level, int optname,
3185 				  char __user *optval, unsigned int optlen)
3186 {
3187 	struct sock *sk = sock->sk;
3188 
3189 	if (sk->sk_prot->compat_setsockopt != NULL)
3190 		return sk->sk_prot->compat_setsockopt(sk, level, optname,
3191 						      optval, optlen);
3192 	return sk->sk_prot->setsockopt(sk, level, optname, optval, optlen);
3193 }
3194 EXPORT_SYMBOL(compat_sock_common_setsockopt);
3195 #endif
3196 
3197 void sk_common_release(struct sock *sk)
3198 {
3199 	if (sk->sk_prot->destroy)
3200 		sk->sk_prot->destroy(sk);
3201 
3202 	/*
3203 	 * Observation: when sock_common_release is called, processes have
3204 	 * no access to socket. But net still has.
3205 	 * Step one, detach it from networking:
3206 	 *
3207 	 * A. Remove from hash tables.
3208 	 */
3209 
3210 	sk->sk_prot->unhash(sk);
3211 
3212 	/*
3213 	 * In this point socket cannot receive new packets, but it is possible
3214 	 * that some packets are in flight because some CPU runs receiver and
3215 	 * did hash table lookup before we unhashed socket. They will achieve
3216 	 * receive queue and will be purged by socket destructor.
3217 	 *
3218 	 * Also we still have packets pending on receive queue and probably,
3219 	 * our own packets waiting in device queues. sock_destroy will drain
3220 	 * receive queue, but transmitted packets will delay socket destruction
3221 	 * until the last reference will be released.
3222 	 */
3223 
3224 	sock_orphan(sk);
3225 
3226 	xfrm_sk_free_policy(sk);
3227 
3228 	sk_refcnt_debug_release(sk);
3229 
3230 	sock_put(sk);
3231 }
3232 EXPORT_SYMBOL(sk_common_release);
3233 
3234 void sk_get_meminfo(const struct sock *sk, u32 *mem)
3235 {
3236 	memset(mem, 0, sizeof(*mem) * SK_MEMINFO_VARS);
3237 
3238 	mem[SK_MEMINFO_RMEM_ALLOC] = sk_rmem_alloc_get(sk);
3239 	mem[SK_MEMINFO_RCVBUF] = READ_ONCE(sk->sk_rcvbuf);
3240 	mem[SK_MEMINFO_WMEM_ALLOC] = sk_wmem_alloc_get(sk);
3241 	mem[SK_MEMINFO_SNDBUF] = READ_ONCE(sk->sk_sndbuf);
3242 	mem[SK_MEMINFO_FWD_ALLOC] = sk->sk_forward_alloc;
3243 	mem[SK_MEMINFO_WMEM_QUEUED] = READ_ONCE(sk->sk_wmem_queued);
3244 	mem[SK_MEMINFO_OPTMEM] = atomic_read(&sk->sk_omem_alloc);
3245 	mem[SK_MEMINFO_BACKLOG] = READ_ONCE(sk->sk_backlog.len);
3246 	mem[SK_MEMINFO_DROPS] = atomic_read(&sk->sk_drops);
3247 }
3248 
3249 #ifdef CONFIG_PROC_FS
3250 #define PROTO_INUSE_NR	64	/* should be enough for the first time */
3251 struct prot_inuse {
3252 	int val[PROTO_INUSE_NR];
3253 };
3254 
3255 static DECLARE_BITMAP(proto_inuse_idx, PROTO_INUSE_NR);
3256 
3257 void sock_prot_inuse_add(struct net *net, struct proto *prot, int val)
3258 {
3259 	__this_cpu_add(net->core.prot_inuse->val[prot->inuse_idx], val);
3260 }
3261 EXPORT_SYMBOL_GPL(sock_prot_inuse_add);
3262 
3263 int sock_prot_inuse_get(struct net *net, struct proto *prot)
3264 {
3265 	int cpu, idx = prot->inuse_idx;
3266 	int res = 0;
3267 
3268 	for_each_possible_cpu(cpu)
3269 		res += per_cpu_ptr(net->core.prot_inuse, cpu)->val[idx];
3270 
3271 	return res >= 0 ? res : 0;
3272 }
3273 EXPORT_SYMBOL_GPL(sock_prot_inuse_get);
3274 
3275 static void sock_inuse_add(struct net *net, int val)
3276 {
3277 	this_cpu_add(*net->core.sock_inuse, val);
3278 }
3279 
3280 int sock_inuse_get(struct net *net)
3281 {
3282 	int cpu, res = 0;
3283 
3284 	for_each_possible_cpu(cpu)
3285 		res += *per_cpu_ptr(net->core.sock_inuse, cpu);
3286 
3287 	return res;
3288 }
3289 
3290 EXPORT_SYMBOL_GPL(sock_inuse_get);
3291 
3292 static int __net_init sock_inuse_init_net(struct net *net)
3293 {
3294 	net->core.prot_inuse = alloc_percpu(struct prot_inuse);
3295 	if (net->core.prot_inuse == NULL)
3296 		return -ENOMEM;
3297 
3298 	net->core.sock_inuse = alloc_percpu(int);
3299 	if (net->core.sock_inuse == NULL)
3300 		goto out;
3301 
3302 	return 0;
3303 
3304 out:
3305 	free_percpu(net->core.prot_inuse);
3306 	return -ENOMEM;
3307 }
3308 
3309 static void __net_exit sock_inuse_exit_net(struct net *net)
3310 {
3311 	free_percpu(net->core.prot_inuse);
3312 	free_percpu(net->core.sock_inuse);
3313 }
3314 
3315 static struct pernet_operations net_inuse_ops = {
3316 	.init = sock_inuse_init_net,
3317 	.exit = sock_inuse_exit_net,
3318 };
3319 
3320 static __init int net_inuse_init(void)
3321 {
3322 	if (register_pernet_subsys(&net_inuse_ops))
3323 		panic("Cannot initialize net inuse counters");
3324 
3325 	return 0;
3326 }
3327 
3328 core_initcall(net_inuse_init);
3329 
3330 static int assign_proto_idx(struct proto *prot)
3331 {
3332 	prot->inuse_idx = find_first_zero_bit(proto_inuse_idx, PROTO_INUSE_NR);
3333 
3334 	if (unlikely(prot->inuse_idx == PROTO_INUSE_NR - 1)) {
3335 		pr_err("PROTO_INUSE_NR exhausted\n");
3336 		return -ENOSPC;
3337 	}
3338 
3339 	set_bit(prot->inuse_idx, proto_inuse_idx);
3340 	return 0;
3341 }
3342 
3343 static void release_proto_idx(struct proto *prot)
3344 {
3345 	if (prot->inuse_idx != PROTO_INUSE_NR - 1)
3346 		clear_bit(prot->inuse_idx, proto_inuse_idx);
3347 }
3348 #else
3349 static inline int assign_proto_idx(struct proto *prot)
3350 {
3351 	return 0;
3352 }
3353 
3354 static inline void release_proto_idx(struct proto *prot)
3355 {
3356 }
3357 
3358 static void sock_inuse_add(struct net *net, int val)
3359 {
3360 }
3361 #endif
3362 
3363 static void req_prot_cleanup(struct request_sock_ops *rsk_prot)
3364 {
3365 	if (!rsk_prot)
3366 		return;
3367 	kfree(rsk_prot->slab_name);
3368 	rsk_prot->slab_name = NULL;
3369 	kmem_cache_destroy(rsk_prot->slab);
3370 	rsk_prot->slab = NULL;
3371 }
3372 
3373 static int req_prot_init(const struct proto *prot)
3374 {
3375 	struct request_sock_ops *rsk_prot = prot->rsk_prot;
3376 
3377 	if (!rsk_prot)
3378 		return 0;
3379 
3380 	rsk_prot->slab_name = kasprintf(GFP_KERNEL, "request_sock_%s",
3381 					prot->name);
3382 	if (!rsk_prot->slab_name)
3383 		return -ENOMEM;
3384 
3385 	rsk_prot->slab = kmem_cache_create(rsk_prot->slab_name,
3386 					   rsk_prot->obj_size, 0,
3387 					   SLAB_ACCOUNT | prot->slab_flags,
3388 					   NULL);
3389 
3390 	if (!rsk_prot->slab) {
3391 		pr_crit("%s: Can't create request sock SLAB cache!\n",
3392 			prot->name);
3393 		return -ENOMEM;
3394 	}
3395 	return 0;
3396 }
3397 
3398 int proto_register(struct proto *prot, int alloc_slab)
3399 {
3400 	int ret = -ENOBUFS;
3401 
3402 	if (alloc_slab) {
3403 		prot->slab = kmem_cache_create_usercopy(prot->name,
3404 					prot->obj_size, 0,
3405 					SLAB_HWCACHE_ALIGN | SLAB_ACCOUNT |
3406 					prot->slab_flags,
3407 					prot->useroffset, prot->usersize,
3408 					NULL);
3409 
3410 		if (prot->slab == NULL) {
3411 			pr_crit("%s: Can't create sock SLAB cache!\n",
3412 				prot->name);
3413 			goto out;
3414 		}
3415 
3416 		if (req_prot_init(prot))
3417 			goto out_free_request_sock_slab;
3418 
3419 		if (prot->twsk_prot != NULL) {
3420 			prot->twsk_prot->twsk_slab_name = kasprintf(GFP_KERNEL, "tw_sock_%s", prot->name);
3421 
3422 			if (prot->twsk_prot->twsk_slab_name == NULL)
3423 				goto out_free_request_sock_slab;
3424 
3425 			prot->twsk_prot->twsk_slab =
3426 				kmem_cache_create(prot->twsk_prot->twsk_slab_name,
3427 						  prot->twsk_prot->twsk_obj_size,
3428 						  0,
3429 						  SLAB_ACCOUNT |
3430 						  prot->slab_flags,
3431 						  NULL);
3432 			if (prot->twsk_prot->twsk_slab == NULL)
3433 				goto out_free_timewait_sock_slab_name;
3434 		}
3435 	}
3436 
3437 	mutex_lock(&proto_list_mutex);
3438 	ret = assign_proto_idx(prot);
3439 	if (ret) {
3440 		mutex_unlock(&proto_list_mutex);
3441 		goto out_free_timewait_sock_slab_name;
3442 	}
3443 	list_add(&prot->node, &proto_list);
3444 	mutex_unlock(&proto_list_mutex);
3445 	return ret;
3446 
3447 out_free_timewait_sock_slab_name:
3448 	if (alloc_slab && prot->twsk_prot)
3449 		kfree(prot->twsk_prot->twsk_slab_name);
3450 out_free_request_sock_slab:
3451 	if (alloc_slab) {
3452 		req_prot_cleanup(prot->rsk_prot);
3453 
3454 		kmem_cache_destroy(prot->slab);
3455 		prot->slab = NULL;
3456 	}
3457 out:
3458 	return ret;
3459 }
3460 EXPORT_SYMBOL(proto_register);
3461 
3462 void proto_unregister(struct proto *prot)
3463 {
3464 	mutex_lock(&proto_list_mutex);
3465 	release_proto_idx(prot);
3466 	list_del(&prot->node);
3467 	mutex_unlock(&proto_list_mutex);
3468 
3469 	kmem_cache_destroy(prot->slab);
3470 	prot->slab = NULL;
3471 
3472 	req_prot_cleanup(prot->rsk_prot);
3473 
3474 	if (prot->twsk_prot != NULL && prot->twsk_prot->twsk_slab != NULL) {
3475 		kmem_cache_destroy(prot->twsk_prot->twsk_slab);
3476 		kfree(prot->twsk_prot->twsk_slab_name);
3477 		prot->twsk_prot->twsk_slab = NULL;
3478 	}
3479 }
3480 EXPORT_SYMBOL(proto_unregister);
3481 
3482 int sock_load_diag_module(int family, int protocol)
3483 {
3484 	if (!protocol) {
3485 		if (!sock_is_registered(family))
3486 			return -ENOENT;
3487 
3488 		return request_module("net-pf-%d-proto-%d-type-%d", PF_NETLINK,
3489 				      NETLINK_SOCK_DIAG, family);
3490 	}
3491 
3492 #ifdef CONFIG_INET
3493 	if (family == AF_INET &&
3494 	    protocol != IPPROTO_RAW &&
3495 	    !rcu_access_pointer(inet_protos[protocol]))
3496 		return -ENOENT;
3497 #endif
3498 
3499 	return request_module("net-pf-%d-proto-%d-type-%d-%d", PF_NETLINK,
3500 			      NETLINK_SOCK_DIAG, family, protocol);
3501 }
3502 EXPORT_SYMBOL(sock_load_diag_module);
3503 
3504 #ifdef CONFIG_PROC_FS
3505 static void *proto_seq_start(struct seq_file *seq, loff_t *pos)
3506 	__acquires(proto_list_mutex)
3507 {
3508 	mutex_lock(&proto_list_mutex);
3509 	return seq_list_start_head(&proto_list, *pos);
3510 }
3511 
3512 static void *proto_seq_next(struct seq_file *seq, void *v, loff_t *pos)
3513 {
3514 	return seq_list_next(v, &proto_list, pos);
3515 }
3516 
3517 static void proto_seq_stop(struct seq_file *seq, void *v)
3518 	__releases(proto_list_mutex)
3519 {
3520 	mutex_unlock(&proto_list_mutex);
3521 }
3522 
3523 static char proto_method_implemented(const void *method)
3524 {
3525 	return method == NULL ? 'n' : 'y';
3526 }
3527 static long sock_prot_memory_allocated(struct proto *proto)
3528 {
3529 	return proto->memory_allocated != NULL ? proto_memory_allocated(proto) : -1L;
3530 }
3531 
3532 static const char *sock_prot_memory_pressure(struct proto *proto)
3533 {
3534 	return proto->memory_pressure != NULL ?
3535 	proto_memory_pressure(proto) ? "yes" : "no" : "NI";
3536 }
3537 
3538 static void proto_seq_printf(struct seq_file *seq, struct proto *proto)
3539 {
3540 
3541 	seq_printf(seq, "%-9s %4u %6d  %6ld   %-3s %6u   %-3s  %-10s "
3542 			"%2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c\n",
3543 		   proto->name,
3544 		   proto->obj_size,
3545 		   sock_prot_inuse_get(seq_file_net(seq), proto),
3546 		   sock_prot_memory_allocated(proto),
3547 		   sock_prot_memory_pressure(proto),
3548 		   proto->max_header,
3549 		   proto->slab == NULL ? "no" : "yes",
3550 		   module_name(proto->owner),
3551 		   proto_method_implemented(proto->close),
3552 		   proto_method_implemented(proto->connect),
3553 		   proto_method_implemented(proto->disconnect),
3554 		   proto_method_implemented(proto->accept),
3555 		   proto_method_implemented(proto->ioctl),
3556 		   proto_method_implemented(proto->init),
3557 		   proto_method_implemented(proto->destroy),
3558 		   proto_method_implemented(proto->shutdown),
3559 		   proto_method_implemented(proto->setsockopt),
3560 		   proto_method_implemented(proto->getsockopt),
3561 		   proto_method_implemented(proto->sendmsg),
3562 		   proto_method_implemented(proto->recvmsg),
3563 		   proto_method_implemented(proto->sendpage),
3564 		   proto_method_implemented(proto->bind),
3565 		   proto_method_implemented(proto->backlog_rcv),
3566 		   proto_method_implemented(proto->hash),
3567 		   proto_method_implemented(proto->unhash),
3568 		   proto_method_implemented(proto->get_port),
3569 		   proto_method_implemented(proto->enter_memory_pressure));
3570 }
3571 
3572 static int proto_seq_show(struct seq_file *seq, void *v)
3573 {
3574 	if (v == &proto_list)
3575 		seq_printf(seq, "%-9s %-4s %-8s %-6s %-5s %-7s %-4s %-10s %s",
3576 			   "protocol",
3577 			   "size",
3578 			   "sockets",
3579 			   "memory",
3580 			   "press",
3581 			   "maxhdr",
3582 			   "slab",
3583 			   "module",
3584 			   "cl co di ac io in de sh ss gs se re sp bi br ha uh gp em\n");
3585 	else
3586 		proto_seq_printf(seq, list_entry(v, struct proto, node));
3587 	return 0;
3588 }
3589 
3590 static const struct seq_operations proto_seq_ops = {
3591 	.start  = proto_seq_start,
3592 	.next   = proto_seq_next,
3593 	.stop   = proto_seq_stop,
3594 	.show   = proto_seq_show,
3595 };
3596 
3597 static __net_init int proto_init_net(struct net *net)
3598 {
3599 	if (!proc_create_net("protocols", 0444, net->proc_net, &proto_seq_ops,
3600 			sizeof(struct seq_net_private)))
3601 		return -ENOMEM;
3602 
3603 	return 0;
3604 }
3605 
3606 static __net_exit void proto_exit_net(struct net *net)
3607 {
3608 	remove_proc_entry("protocols", net->proc_net);
3609 }
3610 
3611 
3612 static __net_initdata struct pernet_operations proto_net_ops = {
3613 	.init = proto_init_net,
3614 	.exit = proto_exit_net,
3615 };
3616 
3617 static int __init proto_init(void)
3618 {
3619 	return register_pernet_subsys(&proto_net_ops);
3620 }
3621 
3622 subsys_initcall(proto_init);
3623 
3624 #endif /* PROC_FS */
3625 
3626 #ifdef CONFIG_NET_RX_BUSY_POLL
3627 bool sk_busy_loop_end(void *p, unsigned long start_time)
3628 {
3629 	struct sock *sk = p;
3630 
3631 	return !skb_queue_empty_lockless(&sk->sk_receive_queue) ||
3632 	       sk_busy_loop_timeout(sk, start_time);
3633 }
3634 EXPORT_SYMBOL(sk_busy_loop_end);
3635 #endif /* CONFIG_NET_RX_BUSY_POLL */
3636