xref: /linux/net/core/sock.c (revision 385f186aba3d2f7122b71d6d4c7e236b9d4e8003)
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 <linux/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/udp.h>
111 #include <linux/init.h>
112 #include <linux/highmem.h>
113 #include <linux/user_namespace.h>
114 #include <linux/static_key.h>
115 #include <linux/memcontrol.h>
116 #include <linux/prefetch.h>
117 #include <linux/compat.h>
118 #include <linux/mroute.h>
119 #include <linux/mroute6.h>
120 #include <linux/icmpv6.h>
121 
122 #include <linux/uaccess.h>
123 
124 #include <linux/netdevice.h>
125 #include <net/protocol.h>
126 #include <linux/skbuff.h>
127 #include <linux/skbuff_ref.h>
128 #include <net/net_namespace.h>
129 #include <net/request_sock.h>
130 #include <net/sock.h>
131 #include <net/proto_memory.h>
132 #include <linux/net_tstamp.h>
133 #include <net/xfrm.h>
134 #include <linux/ipsec.h>
135 #include <net/cls_cgroup.h>
136 #include <net/netprio_cgroup.h>
137 #include <linux/sock_diag.h>
138 
139 #include <linux/filter.h>
140 #include <net/sock_reuseport.h>
141 #include <net/bpf_sk_storage.h>
142 
143 #include <trace/events/sock.h>
144 
145 #include <net/tcp.h>
146 #include <net/busy_poll.h>
147 #include <net/phonet/phonet.h>
148 
149 #include <linux/ethtool.h>
150 
151 #include "dev.h"
152 
153 static DEFINE_MUTEX(proto_list_mutex);
154 static LIST_HEAD(proto_list);
155 
156 static void sock_def_write_space_wfree(struct sock *sk);
157 static void sock_def_write_space(struct sock *sk);
158 
159 /**
160  * sk_ns_capable - General socket capability test
161  * @sk: Socket to use a capability on or through
162  * @user_ns: The user namespace of the capability to use
163  * @cap: The capability to use
164  *
165  * Test to see if the opener of the socket had when the socket was
166  * created and the current process has the capability @cap in the user
167  * namespace @user_ns.
168  */
169 bool sk_ns_capable(const struct sock *sk,
170 		   struct user_namespace *user_ns, int cap)
171 {
172 	return file_ns_capable(sk->sk_socket->file, user_ns, cap) &&
173 		ns_capable(user_ns, cap);
174 }
175 EXPORT_SYMBOL(sk_ns_capable);
176 
177 /**
178  * sk_capable - Socket global capability test
179  * @sk: Socket to use a capability on or through
180  * @cap: The global capability to use
181  *
182  * Test to see if the opener of the socket had when the socket was
183  * created and the current process has the capability @cap in all user
184  * namespaces.
185  */
186 bool sk_capable(const struct sock *sk, int cap)
187 {
188 	return sk_ns_capable(sk, &init_user_ns, cap);
189 }
190 EXPORT_SYMBOL(sk_capable);
191 
192 /**
193  * sk_net_capable - Network namespace socket capability test
194  * @sk: Socket to use a capability on or through
195  * @cap: The capability to use
196  *
197  * Test to see if the opener of the socket had when the socket was created
198  * and the current process has the capability @cap over the network namespace
199  * the socket is a member of.
200  */
201 bool sk_net_capable(const struct sock *sk, int cap)
202 {
203 	return sk_ns_capable(sk, sock_net(sk)->user_ns, cap);
204 }
205 EXPORT_SYMBOL(sk_net_capable);
206 
207 /*
208  * Each address family might have different locking rules, so we have
209  * one slock key per address family and separate keys for internal and
210  * userspace sockets.
211  */
212 static struct lock_class_key af_family_keys[AF_MAX];
213 static struct lock_class_key af_family_kern_keys[AF_MAX];
214 static struct lock_class_key af_family_slock_keys[AF_MAX];
215 static struct lock_class_key af_family_kern_slock_keys[AF_MAX];
216 
217 /*
218  * Make lock validator output more readable. (we pre-construct these
219  * strings build-time, so that runtime initialization of socket
220  * locks is fast):
221  */
222 
223 #define _sock_locks(x)						  \
224   x "AF_UNSPEC",	x "AF_UNIX"     ,	x "AF_INET"     , \
225   x "AF_AX25"  ,	x "AF_IPX"      ,	x "AF_APPLETALK", \
226   x "AF_NETROM",	x "AF_BRIDGE"   ,	x "AF_ATMPVC"   , \
227   x "AF_X25"   ,	x "AF_INET6"    ,	x "AF_ROSE"     , \
228   x "AF_DECnet",	x "AF_NETBEUI"  ,	x "AF_SECURITY" , \
229   x "AF_KEY"   ,	x "AF_NETLINK"  ,	x "AF_PACKET"   , \
230   x "AF_ASH"   ,	x "AF_ECONET"   ,	x "AF_ATMSVC"   , \
231   x "AF_RDS"   ,	x "AF_SNA"      ,	x "AF_IRDA"     , \
232   x "AF_PPPOX" ,	x "AF_WANPIPE"  ,	x "AF_LLC"      , \
233   x "27"       ,	x "28"          ,	x "AF_CAN"      , \
234   x "AF_TIPC"  ,	x "AF_BLUETOOTH",	x "IUCV"        , \
235   x "AF_RXRPC" ,	x "AF_ISDN"     ,	x "AF_PHONET"   , \
236   x "AF_IEEE802154",	x "AF_CAIF"	,	x "AF_ALG"      , \
237   x "AF_NFC"   ,	x "AF_VSOCK"    ,	x "AF_KCM"      , \
238   x "AF_QIPCRTR",	x "AF_SMC"	,	x "AF_XDP"	, \
239   x "AF_MCTP"  , \
240   x "AF_MAX"
241 
242 static const char *const af_family_key_strings[AF_MAX+1] = {
243 	_sock_locks("sk_lock-")
244 };
245 static const char *const af_family_slock_key_strings[AF_MAX+1] = {
246 	_sock_locks("slock-")
247 };
248 static const char *const af_family_clock_key_strings[AF_MAX+1] = {
249 	_sock_locks("clock-")
250 };
251 
252 static const char *const af_family_kern_key_strings[AF_MAX+1] = {
253 	_sock_locks("k-sk_lock-")
254 };
255 static const char *const af_family_kern_slock_key_strings[AF_MAX+1] = {
256 	_sock_locks("k-slock-")
257 };
258 static const char *const af_family_kern_clock_key_strings[AF_MAX+1] = {
259 	_sock_locks("k-clock-")
260 };
261 static const char *const af_family_rlock_key_strings[AF_MAX+1] = {
262 	_sock_locks("rlock-")
263 };
264 static const char *const af_family_wlock_key_strings[AF_MAX+1] = {
265 	_sock_locks("wlock-")
266 };
267 static const char *const af_family_elock_key_strings[AF_MAX+1] = {
268 	_sock_locks("elock-")
269 };
270 
271 /*
272  * sk_callback_lock and sk queues locking rules are per-address-family,
273  * so split the lock classes by using a per-AF key:
274  */
275 static struct lock_class_key af_callback_keys[AF_MAX];
276 static struct lock_class_key af_rlock_keys[AF_MAX];
277 static struct lock_class_key af_wlock_keys[AF_MAX];
278 static struct lock_class_key af_elock_keys[AF_MAX];
279 static struct lock_class_key af_kern_callback_keys[AF_MAX];
280 
281 /* Run time adjustable parameters. */
282 __u32 sysctl_wmem_max __read_mostly = SK_WMEM_MAX;
283 EXPORT_SYMBOL(sysctl_wmem_max);
284 __u32 sysctl_rmem_max __read_mostly = SK_RMEM_MAX;
285 EXPORT_SYMBOL(sysctl_rmem_max);
286 __u32 sysctl_wmem_default __read_mostly = SK_WMEM_MAX;
287 __u32 sysctl_rmem_default __read_mostly = SK_RMEM_MAX;
288 
289 DEFINE_STATIC_KEY_FALSE(memalloc_socks_key);
290 EXPORT_SYMBOL_GPL(memalloc_socks_key);
291 
292 /**
293  * sk_set_memalloc - sets %SOCK_MEMALLOC
294  * @sk: socket to set it on
295  *
296  * Set %SOCK_MEMALLOC on a socket for access to emergency reserves.
297  * It's the responsibility of the admin to adjust min_free_kbytes
298  * to meet the requirements
299  */
300 void sk_set_memalloc(struct sock *sk)
301 {
302 	sock_set_flag(sk, SOCK_MEMALLOC);
303 	sk->sk_allocation |= __GFP_MEMALLOC;
304 	static_branch_inc(&memalloc_socks_key);
305 }
306 EXPORT_SYMBOL_GPL(sk_set_memalloc);
307 
308 void sk_clear_memalloc(struct sock *sk)
309 {
310 	sock_reset_flag(sk, SOCK_MEMALLOC);
311 	sk->sk_allocation &= ~__GFP_MEMALLOC;
312 	static_branch_dec(&memalloc_socks_key);
313 
314 	/*
315 	 * SOCK_MEMALLOC is allowed to ignore rmem limits to ensure forward
316 	 * progress of swapping. SOCK_MEMALLOC may be cleared while
317 	 * it has rmem allocations due to the last swapfile being deactivated
318 	 * but there is a risk that the socket is unusable due to exceeding
319 	 * the rmem limits. Reclaim the reserves and obey rmem limits again.
320 	 */
321 	sk_mem_reclaim(sk);
322 }
323 EXPORT_SYMBOL_GPL(sk_clear_memalloc);
324 
325 int __sk_backlog_rcv(struct sock *sk, struct sk_buff *skb)
326 {
327 	int ret;
328 	unsigned int noreclaim_flag;
329 
330 	/* these should have been dropped before queueing */
331 	BUG_ON(!sock_flag(sk, SOCK_MEMALLOC));
332 
333 	noreclaim_flag = memalloc_noreclaim_save();
334 	ret = INDIRECT_CALL_INET(sk->sk_backlog_rcv,
335 				 tcp_v6_do_rcv,
336 				 tcp_v4_do_rcv,
337 				 sk, skb);
338 	memalloc_noreclaim_restore(noreclaim_flag);
339 
340 	return ret;
341 }
342 EXPORT_SYMBOL(__sk_backlog_rcv);
343 
344 void sk_error_report(struct sock *sk)
345 {
346 	sk->sk_error_report(sk);
347 
348 	switch (sk->sk_family) {
349 	case AF_INET:
350 		fallthrough;
351 	case AF_INET6:
352 		trace_inet_sk_error_report(sk);
353 		break;
354 	default:
355 		break;
356 	}
357 }
358 EXPORT_SYMBOL(sk_error_report);
359 
360 int sock_get_timeout(long timeo, void *optval, bool old_timeval)
361 {
362 	struct __kernel_sock_timeval tv;
363 
364 	if (timeo == MAX_SCHEDULE_TIMEOUT) {
365 		tv.tv_sec = 0;
366 		tv.tv_usec = 0;
367 	} else {
368 		tv.tv_sec = timeo / HZ;
369 		tv.tv_usec = ((timeo % HZ) * USEC_PER_SEC) / HZ;
370 	}
371 
372 	if (old_timeval && in_compat_syscall() && !COMPAT_USE_64BIT_TIME) {
373 		struct old_timeval32 tv32 = { tv.tv_sec, tv.tv_usec };
374 		*(struct old_timeval32 *)optval = tv32;
375 		return sizeof(tv32);
376 	}
377 
378 	if (old_timeval) {
379 		struct __kernel_old_timeval old_tv;
380 		old_tv.tv_sec = tv.tv_sec;
381 		old_tv.tv_usec = tv.tv_usec;
382 		*(struct __kernel_old_timeval *)optval = old_tv;
383 		return sizeof(old_tv);
384 	}
385 
386 	*(struct __kernel_sock_timeval *)optval = tv;
387 	return sizeof(tv);
388 }
389 EXPORT_SYMBOL(sock_get_timeout);
390 
391 int sock_copy_user_timeval(struct __kernel_sock_timeval *tv,
392 			   sockptr_t optval, int optlen, bool old_timeval)
393 {
394 	if (old_timeval && in_compat_syscall() && !COMPAT_USE_64BIT_TIME) {
395 		struct old_timeval32 tv32;
396 
397 		if (optlen < sizeof(tv32))
398 			return -EINVAL;
399 
400 		if (copy_from_sockptr(&tv32, optval, sizeof(tv32)))
401 			return -EFAULT;
402 		tv->tv_sec = tv32.tv_sec;
403 		tv->tv_usec = tv32.tv_usec;
404 	} else if (old_timeval) {
405 		struct __kernel_old_timeval old_tv;
406 
407 		if (optlen < sizeof(old_tv))
408 			return -EINVAL;
409 		if (copy_from_sockptr(&old_tv, optval, sizeof(old_tv)))
410 			return -EFAULT;
411 		tv->tv_sec = old_tv.tv_sec;
412 		tv->tv_usec = old_tv.tv_usec;
413 	} else {
414 		if (optlen < sizeof(*tv))
415 			return -EINVAL;
416 		if (copy_from_sockptr(tv, optval, sizeof(*tv)))
417 			return -EFAULT;
418 	}
419 
420 	return 0;
421 }
422 EXPORT_SYMBOL(sock_copy_user_timeval);
423 
424 static int sock_set_timeout(long *timeo_p, sockptr_t optval, int optlen,
425 			    bool old_timeval)
426 {
427 	struct __kernel_sock_timeval tv;
428 	int err = sock_copy_user_timeval(&tv, optval, optlen, old_timeval);
429 	long val;
430 
431 	if (err)
432 		return err;
433 
434 	if (tv.tv_usec < 0 || tv.tv_usec >= USEC_PER_SEC)
435 		return -EDOM;
436 
437 	if (tv.tv_sec < 0) {
438 		static int warned __read_mostly;
439 
440 		WRITE_ONCE(*timeo_p, 0);
441 		if (warned < 10 && net_ratelimit()) {
442 			warned++;
443 			pr_info("%s: `%s' (pid %d) tries to set negative timeout\n",
444 				__func__, current->comm, task_pid_nr(current));
445 		}
446 		return 0;
447 	}
448 	val = MAX_SCHEDULE_TIMEOUT;
449 	if ((tv.tv_sec || tv.tv_usec) &&
450 	    (tv.tv_sec < (MAX_SCHEDULE_TIMEOUT / HZ - 1)))
451 		val = tv.tv_sec * HZ + DIV_ROUND_UP((unsigned long)tv.tv_usec,
452 						    USEC_PER_SEC / HZ);
453 	WRITE_ONCE(*timeo_p, val);
454 	return 0;
455 }
456 
457 static bool sk_set_prio_allowed(const struct sock *sk, int val)
458 {
459 	return ((val >= TC_PRIO_BESTEFFORT && val <= TC_PRIO_INTERACTIVE) ||
460 		sockopt_ns_capable(sock_net(sk)->user_ns, CAP_NET_RAW) ||
461 		sockopt_ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN));
462 }
463 
464 static bool sock_needs_netstamp(const struct sock *sk)
465 {
466 	switch (sk->sk_family) {
467 	case AF_UNSPEC:
468 	case AF_UNIX:
469 		return false;
470 	default:
471 		return true;
472 	}
473 }
474 
475 static void sock_disable_timestamp(struct sock *sk, unsigned long flags)
476 {
477 	if (sk->sk_flags & flags) {
478 		sk->sk_flags &= ~flags;
479 		if (sock_needs_netstamp(sk) &&
480 		    !(sk->sk_flags & SK_FLAGS_TIMESTAMP))
481 			net_disable_timestamp();
482 	}
483 }
484 
485 
486 int __sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
487 {
488 	unsigned long flags;
489 	struct sk_buff_head *list = &sk->sk_receive_queue;
490 
491 	if (atomic_read(&sk->sk_rmem_alloc) >= READ_ONCE(sk->sk_rcvbuf)) {
492 		atomic_inc(&sk->sk_drops);
493 		trace_sock_rcvqueue_full(sk, skb);
494 		return -ENOMEM;
495 	}
496 
497 	if (!sk_rmem_schedule(sk, skb, skb->truesize)) {
498 		atomic_inc(&sk->sk_drops);
499 		return -ENOBUFS;
500 	}
501 
502 	skb->dev = NULL;
503 	skb_set_owner_r(skb, sk);
504 
505 	/* we escape from rcu protected region, make sure we dont leak
506 	 * a norefcounted dst
507 	 */
508 	skb_dst_force(skb);
509 
510 	spin_lock_irqsave(&list->lock, flags);
511 	sock_skb_set_dropcount(sk, skb);
512 	__skb_queue_tail(list, skb);
513 	spin_unlock_irqrestore(&list->lock, flags);
514 
515 	if (!sock_flag(sk, SOCK_DEAD))
516 		sk->sk_data_ready(sk);
517 	return 0;
518 }
519 EXPORT_SYMBOL(__sock_queue_rcv_skb);
520 
521 int sock_queue_rcv_skb_reason(struct sock *sk, struct sk_buff *skb,
522 			      enum skb_drop_reason *reason)
523 {
524 	enum skb_drop_reason drop_reason;
525 	int err;
526 
527 	err = sk_filter(sk, skb);
528 	if (err) {
529 		drop_reason = SKB_DROP_REASON_SOCKET_FILTER;
530 		goto out;
531 	}
532 	err = __sock_queue_rcv_skb(sk, skb);
533 	switch (err) {
534 	case -ENOMEM:
535 		drop_reason = SKB_DROP_REASON_SOCKET_RCVBUFF;
536 		break;
537 	case -ENOBUFS:
538 		drop_reason = SKB_DROP_REASON_PROTO_MEM;
539 		break;
540 	default:
541 		drop_reason = SKB_NOT_DROPPED_YET;
542 		break;
543 	}
544 out:
545 	if (reason)
546 		*reason = drop_reason;
547 	return err;
548 }
549 EXPORT_SYMBOL(sock_queue_rcv_skb_reason);
550 
551 int __sk_receive_skb(struct sock *sk, struct sk_buff *skb,
552 		     const int nested, unsigned int trim_cap, bool refcounted)
553 {
554 	int rc = NET_RX_SUCCESS;
555 
556 	if (sk_filter_trim_cap(sk, skb, trim_cap))
557 		goto discard_and_relse;
558 
559 	skb->dev = NULL;
560 
561 	if (sk_rcvqueues_full(sk, READ_ONCE(sk->sk_rcvbuf))) {
562 		atomic_inc(&sk->sk_drops);
563 		goto discard_and_relse;
564 	}
565 	if (nested)
566 		bh_lock_sock_nested(sk);
567 	else
568 		bh_lock_sock(sk);
569 	if (!sock_owned_by_user(sk)) {
570 		/*
571 		 * trylock + unlock semantics:
572 		 */
573 		mutex_acquire(&sk->sk_lock.dep_map, 0, 1, _RET_IP_);
574 
575 		rc = sk_backlog_rcv(sk, skb);
576 
577 		mutex_release(&sk->sk_lock.dep_map, _RET_IP_);
578 	} else if (sk_add_backlog(sk, skb, READ_ONCE(sk->sk_rcvbuf))) {
579 		bh_unlock_sock(sk);
580 		atomic_inc(&sk->sk_drops);
581 		goto discard_and_relse;
582 	}
583 
584 	bh_unlock_sock(sk);
585 out:
586 	if (refcounted)
587 		sock_put(sk);
588 	return rc;
589 discard_and_relse:
590 	kfree_skb(skb);
591 	goto out;
592 }
593 EXPORT_SYMBOL(__sk_receive_skb);
594 
595 INDIRECT_CALLABLE_DECLARE(struct dst_entry *ip6_dst_check(struct dst_entry *,
596 							  u32));
597 INDIRECT_CALLABLE_DECLARE(struct dst_entry *ipv4_dst_check(struct dst_entry *,
598 							   u32));
599 struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie)
600 {
601 	struct dst_entry *dst = __sk_dst_get(sk);
602 
603 	if (dst && dst->obsolete &&
604 	    INDIRECT_CALL_INET(dst->ops->check, ip6_dst_check, ipv4_dst_check,
605 			       dst, cookie) == NULL) {
606 		sk_tx_queue_clear(sk);
607 		WRITE_ONCE(sk->sk_dst_pending_confirm, 0);
608 		RCU_INIT_POINTER(sk->sk_dst_cache, NULL);
609 		dst_release(dst);
610 		return NULL;
611 	}
612 
613 	return dst;
614 }
615 EXPORT_SYMBOL(__sk_dst_check);
616 
617 struct dst_entry *sk_dst_check(struct sock *sk, u32 cookie)
618 {
619 	struct dst_entry *dst = sk_dst_get(sk);
620 
621 	if (dst && dst->obsolete &&
622 	    INDIRECT_CALL_INET(dst->ops->check, ip6_dst_check, ipv4_dst_check,
623 			       dst, cookie) == NULL) {
624 		sk_dst_reset(sk);
625 		dst_release(dst);
626 		return NULL;
627 	}
628 
629 	return dst;
630 }
631 EXPORT_SYMBOL(sk_dst_check);
632 
633 static int sock_bindtoindex_locked(struct sock *sk, int ifindex)
634 {
635 	int ret = -ENOPROTOOPT;
636 #ifdef CONFIG_NETDEVICES
637 	struct net *net = sock_net(sk);
638 
639 	/* Sorry... */
640 	ret = -EPERM;
641 	if (sk->sk_bound_dev_if && !ns_capable(net->user_ns, CAP_NET_RAW))
642 		goto out;
643 
644 	ret = -EINVAL;
645 	if (ifindex < 0)
646 		goto out;
647 
648 	/* Paired with all READ_ONCE() done locklessly. */
649 	WRITE_ONCE(sk->sk_bound_dev_if, ifindex);
650 
651 	if (sk->sk_prot->rehash)
652 		sk->sk_prot->rehash(sk);
653 	sk_dst_reset(sk);
654 
655 	ret = 0;
656 
657 out:
658 #endif
659 
660 	return ret;
661 }
662 
663 int sock_bindtoindex(struct sock *sk, int ifindex, bool lock_sk)
664 {
665 	int ret;
666 
667 	if (lock_sk)
668 		lock_sock(sk);
669 	ret = sock_bindtoindex_locked(sk, ifindex);
670 	if (lock_sk)
671 		release_sock(sk);
672 
673 	return ret;
674 }
675 EXPORT_SYMBOL(sock_bindtoindex);
676 
677 static int sock_setbindtodevice(struct sock *sk, sockptr_t optval, int optlen)
678 {
679 	int ret = -ENOPROTOOPT;
680 #ifdef CONFIG_NETDEVICES
681 	struct net *net = sock_net(sk);
682 	char devname[IFNAMSIZ];
683 	int index;
684 
685 	ret = -EINVAL;
686 	if (optlen < 0)
687 		goto out;
688 
689 	/* Bind this socket to a particular device like "eth0",
690 	 * as specified in the passed interface name. If the
691 	 * name is "" or the option length is zero the socket
692 	 * is not bound.
693 	 */
694 	if (optlen > IFNAMSIZ - 1)
695 		optlen = IFNAMSIZ - 1;
696 	memset(devname, 0, sizeof(devname));
697 
698 	ret = -EFAULT;
699 	if (copy_from_sockptr(devname, optval, optlen))
700 		goto out;
701 
702 	index = 0;
703 	if (devname[0] != '\0') {
704 		struct net_device *dev;
705 
706 		rcu_read_lock();
707 		dev = dev_get_by_name_rcu(net, devname);
708 		if (dev)
709 			index = dev->ifindex;
710 		rcu_read_unlock();
711 		ret = -ENODEV;
712 		if (!dev)
713 			goto out;
714 	}
715 
716 	sockopt_lock_sock(sk);
717 	ret = sock_bindtoindex_locked(sk, index);
718 	sockopt_release_sock(sk);
719 out:
720 #endif
721 
722 	return ret;
723 }
724 
725 static int sock_getbindtodevice(struct sock *sk, sockptr_t optval,
726 				sockptr_t optlen, int len)
727 {
728 	int ret = -ENOPROTOOPT;
729 #ifdef CONFIG_NETDEVICES
730 	int bound_dev_if = READ_ONCE(sk->sk_bound_dev_if);
731 	struct net *net = sock_net(sk);
732 	char devname[IFNAMSIZ];
733 
734 	if (bound_dev_if == 0) {
735 		len = 0;
736 		goto zero;
737 	}
738 
739 	ret = -EINVAL;
740 	if (len < IFNAMSIZ)
741 		goto out;
742 
743 	ret = netdev_get_name(net, devname, bound_dev_if);
744 	if (ret)
745 		goto out;
746 
747 	len = strlen(devname) + 1;
748 
749 	ret = -EFAULT;
750 	if (copy_to_sockptr(optval, devname, len))
751 		goto out;
752 
753 zero:
754 	ret = -EFAULT;
755 	if (copy_to_sockptr(optlen, &len, sizeof(int)))
756 		goto out;
757 
758 	ret = 0;
759 
760 out:
761 #endif
762 
763 	return ret;
764 }
765 
766 bool sk_mc_loop(const struct sock *sk)
767 {
768 	if (dev_recursion_level())
769 		return false;
770 	if (!sk)
771 		return true;
772 	/* IPV6_ADDRFORM can change sk->sk_family under us. */
773 	switch (READ_ONCE(sk->sk_family)) {
774 	case AF_INET:
775 		return inet_test_bit(MC_LOOP, sk);
776 #if IS_ENABLED(CONFIG_IPV6)
777 	case AF_INET6:
778 		return inet6_test_bit(MC6_LOOP, sk);
779 #endif
780 	}
781 	WARN_ON_ONCE(1);
782 	return true;
783 }
784 EXPORT_SYMBOL(sk_mc_loop);
785 
786 void sock_set_reuseaddr(struct sock *sk)
787 {
788 	lock_sock(sk);
789 	sk->sk_reuse = SK_CAN_REUSE;
790 	release_sock(sk);
791 }
792 EXPORT_SYMBOL(sock_set_reuseaddr);
793 
794 void sock_set_reuseport(struct sock *sk)
795 {
796 	lock_sock(sk);
797 	sk->sk_reuseport = true;
798 	release_sock(sk);
799 }
800 EXPORT_SYMBOL(sock_set_reuseport);
801 
802 void sock_no_linger(struct sock *sk)
803 {
804 	lock_sock(sk);
805 	WRITE_ONCE(sk->sk_lingertime, 0);
806 	sock_set_flag(sk, SOCK_LINGER);
807 	release_sock(sk);
808 }
809 EXPORT_SYMBOL(sock_no_linger);
810 
811 void sock_set_priority(struct sock *sk, u32 priority)
812 {
813 	WRITE_ONCE(sk->sk_priority, priority);
814 }
815 EXPORT_SYMBOL(sock_set_priority);
816 
817 void sock_set_sndtimeo(struct sock *sk, s64 secs)
818 {
819 	lock_sock(sk);
820 	if (secs && secs < MAX_SCHEDULE_TIMEOUT / HZ - 1)
821 		WRITE_ONCE(sk->sk_sndtimeo, secs * HZ);
822 	else
823 		WRITE_ONCE(sk->sk_sndtimeo, MAX_SCHEDULE_TIMEOUT);
824 	release_sock(sk);
825 }
826 EXPORT_SYMBOL(sock_set_sndtimeo);
827 
828 static void __sock_set_timestamps(struct sock *sk, bool val, bool new, bool ns)
829 {
830 	sock_valbool_flag(sk, SOCK_RCVTSTAMP, val);
831 	sock_valbool_flag(sk, SOCK_RCVTSTAMPNS, val && ns);
832 	if (val)  {
833 		sock_valbool_flag(sk, SOCK_TSTAMP_NEW, new);
834 		sock_enable_timestamp(sk, SOCK_TIMESTAMP);
835 	}
836 }
837 
838 void sock_enable_timestamps(struct sock *sk)
839 {
840 	lock_sock(sk);
841 	__sock_set_timestamps(sk, true, false, true);
842 	release_sock(sk);
843 }
844 EXPORT_SYMBOL(sock_enable_timestamps);
845 
846 void sock_set_timestamp(struct sock *sk, int optname, bool valbool)
847 {
848 	switch (optname) {
849 	case SO_TIMESTAMP_OLD:
850 		__sock_set_timestamps(sk, valbool, false, false);
851 		break;
852 	case SO_TIMESTAMP_NEW:
853 		__sock_set_timestamps(sk, valbool, true, false);
854 		break;
855 	case SO_TIMESTAMPNS_OLD:
856 		__sock_set_timestamps(sk, valbool, false, true);
857 		break;
858 	case SO_TIMESTAMPNS_NEW:
859 		__sock_set_timestamps(sk, valbool, true, true);
860 		break;
861 	}
862 }
863 
864 static int sock_timestamping_bind_phc(struct sock *sk, int phc_index)
865 {
866 	struct net *net = sock_net(sk);
867 	struct net_device *dev = NULL;
868 	bool match = false;
869 	int *vclock_index;
870 	int i, num;
871 
872 	if (sk->sk_bound_dev_if)
873 		dev = dev_get_by_index(net, sk->sk_bound_dev_if);
874 
875 	if (!dev) {
876 		pr_err("%s: sock not bind to device\n", __func__);
877 		return -EOPNOTSUPP;
878 	}
879 
880 	num = ethtool_get_phc_vclocks(dev, &vclock_index);
881 	dev_put(dev);
882 
883 	for (i = 0; i < num; i++) {
884 		if (*(vclock_index + i) == phc_index) {
885 			match = true;
886 			break;
887 		}
888 	}
889 
890 	if (num > 0)
891 		kfree(vclock_index);
892 
893 	if (!match)
894 		return -EINVAL;
895 
896 	WRITE_ONCE(sk->sk_bind_phc, phc_index);
897 
898 	return 0;
899 }
900 
901 int sock_set_timestamping(struct sock *sk, int optname,
902 			  struct so_timestamping timestamping)
903 {
904 	int val = timestamping.flags;
905 	int ret;
906 
907 	if (val & ~SOF_TIMESTAMPING_MASK)
908 		return -EINVAL;
909 
910 	if (val & SOF_TIMESTAMPING_OPT_ID_TCP &&
911 	    !(val & SOF_TIMESTAMPING_OPT_ID))
912 		return -EINVAL;
913 
914 	if (val & SOF_TIMESTAMPING_OPT_ID &&
915 	    !(sk->sk_tsflags & SOF_TIMESTAMPING_OPT_ID)) {
916 		if (sk_is_tcp(sk)) {
917 			if ((1 << sk->sk_state) &
918 			    (TCPF_CLOSE | TCPF_LISTEN))
919 				return -EINVAL;
920 			if (val & SOF_TIMESTAMPING_OPT_ID_TCP)
921 				atomic_set(&sk->sk_tskey, tcp_sk(sk)->write_seq);
922 			else
923 				atomic_set(&sk->sk_tskey, tcp_sk(sk)->snd_una);
924 		} else {
925 			atomic_set(&sk->sk_tskey, 0);
926 		}
927 	}
928 
929 	if (val & SOF_TIMESTAMPING_OPT_STATS &&
930 	    !(val & SOF_TIMESTAMPING_OPT_TSONLY))
931 		return -EINVAL;
932 
933 	if (val & SOF_TIMESTAMPING_BIND_PHC) {
934 		ret = sock_timestamping_bind_phc(sk, timestamping.bind_phc);
935 		if (ret)
936 			return ret;
937 	}
938 
939 	WRITE_ONCE(sk->sk_tsflags, val);
940 	sock_valbool_flag(sk, SOCK_TSTAMP_NEW, optname == SO_TIMESTAMPING_NEW);
941 
942 	if (val & SOF_TIMESTAMPING_RX_SOFTWARE)
943 		sock_enable_timestamp(sk,
944 				      SOCK_TIMESTAMPING_RX_SOFTWARE);
945 	else
946 		sock_disable_timestamp(sk,
947 				       (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE));
948 	return 0;
949 }
950 
951 void sock_set_keepalive(struct sock *sk)
952 {
953 	lock_sock(sk);
954 	if (sk->sk_prot->keepalive)
955 		sk->sk_prot->keepalive(sk, true);
956 	sock_valbool_flag(sk, SOCK_KEEPOPEN, true);
957 	release_sock(sk);
958 }
959 EXPORT_SYMBOL(sock_set_keepalive);
960 
961 static void __sock_set_rcvbuf(struct sock *sk, int val)
962 {
963 	/* Ensure val * 2 fits into an int, to prevent max_t() from treating it
964 	 * as a negative value.
965 	 */
966 	val = min_t(int, val, INT_MAX / 2);
967 	sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
968 
969 	/* We double it on the way in to account for "struct sk_buff" etc.
970 	 * overhead.   Applications assume that the SO_RCVBUF setting they make
971 	 * will allow that much actual data to be received on that socket.
972 	 *
973 	 * Applications are unaware that "struct sk_buff" and other overheads
974 	 * allocate from the receive buffer during socket buffer allocation.
975 	 *
976 	 * And after considering the possible alternatives, returning the value
977 	 * we actually used in getsockopt is the most desirable behavior.
978 	 */
979 	WRITE_ONCE(sk->sk_rcvbuf, max_t(int, val * 2, SOCK_MIN_RCVBUF));
980 }
981 
982 void sock_set_rcvbuf(struct sock *sk, int val)
983 {
984 	lock_sock(sk);
985 	__sock_set_rcvbuf(sk, val);
986 	release_sock(sk);
987 }
988 EXPORT_SYMBOL(sock_set_rcvbuf);
989 
990 static void __sock_set_mark(struct sock *sk, u32 val)
991 {
992 	if (val != sk->sk_mark) {
993 		WRITE_ONCE(sk->sk_mark, val);
994 		sk_dst_reset(sk);
995 	}
996 }
997 
998 void sock_set_mark(struct sock *sk, u32 val)
999 {
1000 	lock_sock(sk);
1001 	__sock_set_mark(sk, val);
1002 	release_sock(sk);
1003 }
1004 EXPORT_SYMBOL(sock_set_mark);
1005 
1006 static void sock_release_reserved_memory(struct sock *sk, int bytes)
1007 {
1008 	/* Round down bytes to multiple of pages */
1009 	bytes = round_down(bytes, PAGE_SIZE);
1010 
1011 	WARN_ON(bytes > sk->sk_reserved_mem);
1012 	WRITE_ONCE(sk->sk_reserved_mem, sk->sk_reserved_mem - bytes);
1013 	sk_mem_reclaim(sk);
1014 }
1015 
1016 static int sock_reserve_memory(struct sock *sk, int bytes)
1017 {
1018 	long allocated;
1019 	bool charged;
1020 	int pages;
1021 
1022 	if (!mem_cgroup_sockets_enabled || !sk->sk_memcg || !sk_has_account(sk))
1023 		return -EOPNOTSUPP;
1024 
1025 	if (!bytes)
1026 		return 0;
1027 
1028 	pages = sk_mem_pages(bytes);
1029 
1030 	/* pre-charge to memcg */
1031 	charged = mem_cgroup_charge_skmem(sk->sk_memcg, pages,
1032 					  GFP_KERNEL | __GFP_RETRY_MAYFAIL);
1033 	if (!charged)
1034 		return -ENOMEM;
1035 
1036 	/* pre-charge to forward_alloc */
1037 	sk_memory_allocated_add(sk, pages);
1038 	allocated = sk_memory_allocated(sk);
1039 	/* If the system goes into memory pressure with this
1040 	 * precharge, give up and return error.
1041 	 */
1042 	if (allocated > sk_prot_mem_limits(sk, 1)) {
1043 		sk_memory_allocated_sub(sk, pages);
1044 		mem_cgroup_uncharge_skmem(sk->sk_memcg, pages);
1045 		return -ENOMEM;
1046 	}
1047 	sk_forward_alloc_add(sk, pages << PAGE_SHIFT);
1048 
1049 	WRITE_ONCE(sk->sk_reserved_mem,
1050 		   sk->sk_reserved_mem + (pages << PAGE_SHIFT));
1051 
1052 	return 0;
1053 }
1054 
1055 #ifdef CONFIG_PAGE_POOL
1056 
1057 /* This is the number of tokens and frags that the user can SO_DEVMEM_DONTNEED
1058  * in 1 syscall. The limit exists to limit the amount of memory the kernel
1059  * allocates to copy these tokens, and to prevent looping over the frags for
1060  * too long.
1061  */
1062 #define MAX_DONTNEED_TOKENS 128
1063 #define MAX_DONTNEED_FRAGS 1024
1064 
1065 static noinline_for_stack int
1066 sock_devmem_dontneed(struct sock *sk, sockptr_t optval, unsigned int optlen)
1067 {
1068 	unsigned int num_tokens, i, j, k, netmem_num = 0;
1069 	struct dmabuf_token *tokens;
1070 	int ret = 0, num_frags = 0;
1071 	netmem_ref netmems[16];
1072 
1073 	if (!sk_is_tcp(sk))
1074 		return -EBADF;
1075 
1076 	if (optlen % sizeof(*tokens) ||
1077 	    optlen > sizeof(*tokens) * MAX_DONTNEED_TOKENS)
1078 		return -EINVAL;
1079 
1080 	num_tokens = optlen / sizeof(*tokens);
1081 	tokens = kvmalloc_array(num_tokens, sizeof(*tokens), GFP_KERNEL);
1082 	if (!tokens)
1083 		return -ENOMEM;
1084 
1085 	if (copy_from_sockptr(tokens, optval, optlen)) {
1086 		kvfree(tokens);
1087 		return -EFAULT;
1088 	}
1089 
1090 	xa_lock_bh(&sk->sk_user_frags);
1091 	for (i = 0; i < num_tokens; i++) {
1092 		for (j = 0; j < tokens[i].token_count; j++) {
1093 			if (++num_frags > MAX_DONTNEED_FRAGS)
1094 				goto frag_limit_reached;
1095 
1096 			netmem_ref netmem = (__force netmem_ref)__xa_erase(
1097 				&sk->sk_user_frags, tokens[i].token_start + j);
1098 
1099 			if (!netmem || WARN_ON_ONCE(!netmem_is_net_iov(netmem)))
1100 				continue;
1101 
1102 			netmems[netmem_num++] = netmem;
1103 			if (netmem_num == ARRAY_SIZE(netmems)) {
1104 				xa_unlock_bh(&sk->sk_user_frags);
1105 				for (k = 0; k < netmem_num; k++)
1106 					WARN_ON_ONCE(!napi_pp_put_page(netmems[k]));
1107 				netmem_num = 0;
1108 				xa_lock_bh(&sk->sk_user_frags);
1109 			}
1110 			ret++;
1111 		}
1112 	}
1113 
1114 frag_limit_reached:
1115 	xa_unlock_bh(&sk->sk_user_frags);
1116 	for (k = 0; k < netmem_num; k++)
1117 		WARN_ON_ONCE(!napi_pp_put_page(netmems[k]));
1118 
1119 	kvfree(tokens);
1120 	return ret;
1121 }
1122 #endif
1123 
1124 void sockopt_lock_sock(struct sock *sk)
1125 {
1126 	/* When current->bpf_ctx is set, the setsockopt is called from
1127 	 * a bpf prog.  bpf has ensured the sk lock has been
1128 	 * acquired before calling setsockopt().
1129 	 */
1130 	if (has_current_bpf_ctx())
1131 		return;
1132 
1133 	lock_sock(sk);
1134 }
1135 EXPORT_SYMBOL(sockopt_lock_sock);
1136 
1137 void sockopt_release_sock(struct sock *sk)
1138 {
1139 	if (has_current_bpf_ctx())
1140 		return;
1141 
1142 	release_sock(sk);
1143 }
1144 EXPORT_SYMBOL(sockopt_release_sock);
1145 
1146 bool sockopt_ns_capable(struct user_namespace *ns, int cap)
1147 {
1148 	return has_current_bpf_ctx() || ns_capable(ns, cap);
1149 }
1150 EXPORT_SYMBOL(sockopt_ns_capable);
1151 
1152 bool sockopt_capable(int cap)
1153 {
1154 	return has_current_bpf_ctx() || capable(cap);
1155 }
1156 EXPORT_SYMBOL(sockopt_capable);
1157 
1158 static int sockopt_validate_clockid(__kernel_clockid_t value)
1159 {
1160 	switch (value) {
1161 	case CLOCK_REALTIME:
1162 	case CLOCK_MONOTONIC:
1163 	case CLOCK_TAI:
1164 		return 0;
1165 	}
1166 	return -EINVAL;
1167 }
1168 
1169 /*
1170  *	This is meant for all protocols to use and covers goings on
1171  *	at the socket level. Everything here is generic.
1172  */
1173 
1174 int sk_setsockopt(struct sock *sk, int level, int optname,
1175 		  sockptr_t optval, unsigned int optlen)
1176 {
1177 	struct so_timestamping timestamping;
1178 	struct socket *sock = sk->sk_socket;
1179 	struct sock_txtime sk_txtime;
1180 	int val;
1181 	int valbool;
1182 	struct linger ling;
1183 	int ret = 0;
1184 
1185 	/*
1186 	 *	Options without arguments
1187 	 */
1188 
1189 	if (optname == SO_BINDTODEVICE)
1190 		return sock_setbindtodevice(sk, optval, optlen);
1191 
1192 	if (optlen < sizeof(int))
1193 		return -EINVAL;
1194 
1195 	if (copy_from_sockptr(&val, optval, sizeof(val)))
1196 		return -EFAULT;
1197 
1198 	valbool = val ? 1 : 0;
1199 
1200 	/* handle options which do not require locking the socket. */
1201 	switch (optname) {
1202 	case SO_PRIORITY:
1203 		if (sk_set_prio_allowed(sk, val)) {
1204 			sock_set_priority(sk, val);
1205 			return 0;
1206 		}
1207 		return -EPERM;
1208 	case SO_PASSSEC:
1209 		assign_bit(SOCK_PASSSEC, &sock->flags, valbool);
1210 		return 0;
1211 	case SO_PASSCRED:
1212 		assign_bit(SOCK_PASSCRED, &sock->flags, valbool);
1213 		return 0;
1214 	case SO_PASSPIDFD:
1215 		assign_bit(SOCK_PASSPIDFD, &sock->flags, valbool);
1216 		return 0;
1217 	case SO_TYPE:
1218 	case SO_PROTOCOL:
1219 	case SO_DOMAIN:
1220 	case SO_ERROR:
1221 		return -ENOPROTOOPT;
1222 #ifdef CONFIG_NET_RX_BUSY_POLL
1223 	case SO_BUSY_POLL:
1224 		if (val < 0)
1225 			return -EINVAL;
1226 		WRITE_ONCE(sk->sk_ll_usec, val);
1227 		return 0;
1228 	case SO_PREFER_BUSY_POLL:
1229 		if (valbool && !sockopt_capable(CAP_NET_ADMIN))
1230 			return -EPERM;
1231 		WRITE_ONCE(sk->sk_prefer_busy_poll, valbool);
1232 		return 0;
1233 	case SO_BUSY_POLL_BUDGET:
1234 		if (val > READ_ONCE(sk->sk_busy_poll_budget) &&
1235 		    !sockopt_capable(CAP_NET_ADMIN))
1236 			return -EPERM;
1237 		if (val < 0 || val > U16_MAX)
1238 			return -EINVAL;
1239 		WRITE_ONCE(sk->sk_busy_poll_budget, val);
1240 		return 0;
1241 #endif
1242 	case SO_MAX_PACING_RATE:
1243 		{
1244 		unsigned long ulval = (val == ~0U) ? ~0UL : (unsigned int)val;
1245 		unsigned long pacing_rate;
1246 
1247 		if (sizeof(ulval) != sizeof(val) &&
1248 		    optlen >= sizeof(ulval) &&
1249 		    copy_from_sockptr(&ulval, optval, sizeof(ulval))) {
1250 			return -EFAULT;
1251 		}
1252 		if (ulval != ~0UL)
1253 			cmpxchg(&sk->sk_pacing_status,
1254 				SK_PACING_NONE,
1255 				SK_PACING_NEEDED);
1256 		/* Pairs with READ_ONCE() from sk_getsockopt() */
1257 		WRITE_ONCE(sk->sk_max_pacing_rate, ulval);
1258 		pacing_rate = READ_ONCE(sk->sk_pacing_rate);
1259 		if (ulval < pacing_rate)
1260 			WRITE_ONCE(sk->sk_pacing_rate, ulval);
1261 		return 0;
1262 		}
1263 	case SO_TXREHASH:
1264 		if (val < -1 || val > 1)
1265 			return -EINVAL;
1266 		if ((u8)val == SOCK_TXREHASH_DEFAULT)
1267 			val = READ_ONCE(sock_net(sk)->core.sysctl_txrehash);
1268 		/* Paired with READ_ONCE() in tcp_rtx_synack()
1269 		 * and sk_getsockopt().
1270 		 */
1271 		WRITE_ONCE(sk->sk_txrehash, (u8)val);
1272 		return 0;
1273 	case SO_PEEK_OFF:
1274 		{
1275 		int (*set_peek_off)(struct sock *sk, int val);
1276 
1277 		set_peek_off = READ_ONCE(sock->ops)->set_peek_off;
1278 		if (set_peek_off)
1279 			ret = set_peek_off(sk, val);
1280 		else
1281 			ret = -EOPNOTSUPP;
1282 		return ret;
1283 		}
1284 #ifdef CONFIG_PAGE_POOL
1285 	case SO_DEVMEM_DONTNEED:
1286 		return sock_devmem_dontneed(sk, optval, optlen);
1287 #endif
1288 	}
1289 
1290 	sockopt_lock_sock(sk);
1291 
1292 	switch (optname) {
1293 	case SO_DEBUG:
1294 		if (val && !sockopt_capable(CAP_NET_ADMIN))
1295 			ret = -EACCES;
1296 		else
1297 			sock_valbool_flag(sk, SOCK_DBG, valbool);
1298 		break;
1299 	case SO_REUSEADDR:
1300 		sk->sk_reuse = (valbool ? SK_CAN_REUSE : SK_NO_REUSE);
1301 		break;
1302 	case SO_REUSEPORT:
1303 		if (valbool && !sk_is_inet(sk))
1304 			ret = -EOPNOTSUPP;
1305 		else
1306 			sk->sk_reuseport = valbool;
1307 		break;
1308 	case SO_DONTROUTE:
1309 		sock_valbool_flag(sk, SOCK_LOCALROUTE, valbool);
1310 		sk_dst_reset(sk);
1311 		break;
1312 	case SO_BROADCAST:
1313 		sock_valbool_flag(sk, SOCK_BROADCAST, valbool);
1314 		break;
1315 	case SO_SNDBUF:
1316 		/* Don't error on this BSD doesn't and if you think
1317 		 * about it this is right. Otherwise apps have to
1318 		 * play 'guess the biggest size' games. RCVBUF/SNDBUF
1319 		 * are treated in BSD as hints
1320 		 */
1321 		val = min_t(u32, val, READ_ONCE(sysctl_wmem_max));
1322 set_sndbuf:
1323 		/* Ensure val * 2 fits into an int, to prevent max_t()
1324 		 * from treating it as a negative value.
1325 		 */
1326 		val = min_t(int, val, INT_MAX / 2);
1327 		sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
1328 		WRITE_ONCE(sk->sk_sndbuf,
1329 			   max_t(int, val * 2, SOCK_MIN_SNDBUF));
1330 		/* Wake up sending tasks if we upped the value. */
1331 		sk->sk_write_space(sk);
1332 		break;
1333 
1334 	case SO_SNDBUFFORCE:
1335 		if (!sockopt_capable(CAP_NET_ADMIN)) {
1336 			ret = -EPERM;
1337 			break;
1338 		}
1339 
1340 		/* No negative values (to prevent underflow, as val will be
1341 		 * multiplied by 2).
1342 		 */
1343 		if (val < 0)
1344 			val = 0;
1345 		goto set_sndbuf;
1346 
1347 	case SO_RCVBUF:
1348 		/* Don't error on this BSD doesn't and if you think
1349 		 * about it this is right. Otherwise apps have to
1350 		 * play 'guess the biggest size' games. RCVBUF/SNDBUF
1351 		 * are treated in BSD as hints
1352 		 */
1353 		__sock_set_rcvbuf(sk, min_t(u32, val, READ_ONCE(sysctl_rmem_max)));
1354 		break;
1355 
1356 	case SO_RCVBUFFORCE:
1357 		if (!sockopt_capable(CAP_NET_ADMIN)) {
1358 			ret = -EPERM;
1359 			break;
1360 		}
1361 
1362 		/* No negative values (to prevent underflow, as val will be
1363 		 * multiplied by 2).
1364 		 */
1365 		__sock_set_rcvbuf(sk, max(val, 0));
1366 		break;
1367 
1368 	case SO_KEEPALIVE:
1369 		if (sk->sk_prot->keepalive)
1370 			sk->sk_prot->keepalive(sk, valbool);
1371 		sock_valbool_flag(sk, SOCK_KEEPOPEN, valbool);
1372 		break;
1373 
1374 	case SO_OOBINLINE:
1375 		sock_valbool_flag(sk, SOCK_URGINLINE, valbool);
1376 		break;
1377 
1378 	case SO_NO_CHECK:
1379 		sk->sk_no_check_tx = valbool;
1380 		break;
1381 
1382 	case SO_LINGER:
1383 		if (optlen < sizeof(ling)) {
1384 			ret = -EINVAL;	/* 1003.1g */
1385 			break;
1386 		}
1387 		if (copy_from_sockptr(&ling, optval, sizeof(ling))) {
1388 			ret = -EFAULT;
1389 			break;
1390 		}
1391 		if (!ling.l_onoff) {
1392 			sock_reset_flag(sk, SOCK_LINGER);
1393 		} else {
1394 			unsigned long t_sec = ling.l_linger;
1395 
1396 			if (t_sec >= MAX_SCHEDULE_TIMEOUT / HZ)
1397 				WRITE_ONCE(sk->sk_lingertime, MAX_SCHEDULE_TIMEOUT);
1398 			else
1399 				WRITE_ONCE(sk->sk_lingertime, t_sec * HZ);
1400 			sock_set_flag(sk, SOCK_LINGER);
1401 		}
1402 		break;
1403 
1404 	case SO_BSDCOMPAT:
1405 		break;
1406 
1407 	case SO_TIMESTAMP_OLD:
1408 	case SO_TIMESTAMP_NEW:
1409 	case SO_TIMESTAMPNS_OLD:
1410 	case SO_TIMESTAMPNS_NEW:
1411 		sock_set_timestamp(sk, optname, valbool);
1412 		break;
1413 
1414 	case SO_TIMESTAMPING_NEW:
1415 	case SO_TIMESTAMPING_OLD:
1416 		if (optlen == sizeof(timestamping)) {
1417 			if (copy_from_sockptr(&timestamping, optval,
1418 					      sizeof(timestamping))) {
1419 				ret = -EFAULT;
1420 				break;
1421 			}
1422 		} else {
1423 			memset(&timestamping, 0, sizeof(timestamping));
1424 			timestamping.flags = val;
1425 		}
1426 		ret = sock_set_timestamping(sk, optname, timestamping);
1427 		break;
1428 
1429 	case SO_RCVLOWAT:
1430 		{
1431 		int (*set_rcvlowat)(struct sock *sk, int val) = NULL;
1432 
1433 		if (val < 0)
1434 			val = INT_MAX;
1435 		if (sock)
1436 			set_rcvlowat = READ_ONCE(sock->ops)->set_rcvlowat;
1437 		if (set_rcvlowat)
1438 			ret = set_rcvlowat(sk, val);
1439 		else
1440 			WRITE_ONCE(sk->sk_rcvlowat, val ? : 1);
1441 		break;
1442 		}
1443 	case SO_RCVTIMEO_OLD:
1444 	case SO_RCVTIMEO_NEW:
1445 		ret = sock_set_timeout(&sk->sk_rcvtimeo, optval,
1446 				       optlen, optname == SO_RCVTIMEO_OLD);
1447 		break;
1448 
1449 	case SO_SNDTIMEO_OLD:
1450 	case SO_SNDTIMEO_NEW:
1451 		ret = sock_set_timeout(&sk->sk_sndtimeo, optval,
1452 				       optlen, optname == SO_SNDTIMEO_OLD);
1453 		break;
1454 
1455 	case SO_ATTACH_FILTER: {
1456 		struct sock_fprog fprog;
1457 
1458 		ret = copy_bpf_fprog_from_user(&fprog, optval, optlen);
1459 		if (!ret)
1460 			ret = sk_attach_filter(&fprog, sk);
1461 		break;
1462 	}
1463 	case SO_ATTACH_BPF:
1464 		ret = -EINVAL;
1465 		if (optlen == sizeof(u32)) {
1466 			u32 ufd;
1467 
1468 			ret = -EFAULT;
1469 			if (copy_from_sockptr(&ufd, optval, sizeof(ufd)))
1470 				break;
1471 
1472 			ret = sk_attach_bpf(ufd, sk);
1473 		}
1474 		break;
1475 
1476 	case SO_ATTACH_REUSEPORT_CBPF: {
1477 		struct sock_fprog fprog;
1478 
1479 		ret = copy_bpf_fprog_from_user(&fprog, optval, optlen);
1480 		if (!ret)
1481 			ret = sk_reuseport_attach_filter(&fprog, sk);
1482 		break;
1483 	}
1484 	case SO_ATTACH_REUSEPORT_EBPF:
1485 		ret = -EINVAL;
1486 		if (optlen == sizeof(u32)) {
1487 			u32 ufd;
1488 
1489 			ret = -EFAULT;
1490 			if (copy_from_sockptr(&ufd, optval, sizeof(ufd)))
1491 				break;
1492 
1493 			ret = sk_reuseport_attach_bpf(ufd, sk);
1494 		}
1495 		break;
1496 
1497 	case SO_DETACH_REUSEPORT_BPF:
1498 		ret = reuseport_detach_prog(sk);
1499 		break;
1500 
1501 	case SO_DETACH_FILTER:
1502 		ret = sk_detach_filter(sk);
1503 		break;
1504 
1505 	case SO_LOCK_FILTER:
1506 		if (sock_flag(sk, SOCK_FILTER_LOCKED) && !valbool)
1507 			ret = -EPERM;
1508 		else
1509 			sock_valbool_flag(sk, SOCK_FILTER_LOCKED, valbool);
1510 		break;
1511 
1512 	case SO_MARK:
1513 		if (!sockopt_ns_capable(sock_net(sk)->user_ns, CAP_NET_RAW) &&
1514 		    !sockopt_ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) {
1515 			ret = -EPERM;
1516 			break;
1517 		}
1518 
1519 		__sock_set_mark(sk, val);
1520 		break;
1521 	case SO_RCVMARK:
1522 		sock_valbool_flag(sk, SOCK_RCVMARK, valbool);
1523 		break;
1524 
1525 	case SO_RCVPRIORITY:
1526 		sock_valbool_flag(sk, SOCK_RCVPRIORITY, valbool);
1527 		break;
1528 
1529 	case SO_RXQ_OVFL:
1530 		sock_valbool_flag(sk, SOCK_RXQ_OVFL, valbool);
1531 		break;
1532 
1533 	case SO_WIFI_STATUS:
1534 		sock_valbool_flag(sk, SOCK_WIFI_STATUS, valbool);
1535 		break;
1536 
1537 	case SO_NOFCS:
1538 		sock_valbool_flag(sk, SOCK_NOFCS, valbool);
1539 		break;
1540 
1541 	case SO_SELECT_ERR_QUEUE:
1542 		sock_valbool_flag(sk, SOCK_SELECT_ERR_QUEUE, valbool);
1543 		break;
1544 
1545 
1546 	case SO_INCOMING_CPU:
1547 		reuseport_update_incoming_cpu(sk, val);
1548 		break;
1549 
1550 	case SO_CNX_ADVICE:
1551 		if (val == 1)
1552 			dst_negative_advice(sk);
1553 		break;
1554 
1555 	case SO_ZEROCOPY:
1556 		if (sk->sk_family == PF_INET || sk->sk_family == PF_INET6) {
1557 			if (!(sk_is_tcp(sk) ||
1558 			      (sk->sk_type == SOCK_DGRAM &&
1559 			       sk->sk_protocol == IPPROTO_UDP)))
1560 				ret = -EOPNOTSUPP;
1561 		} else if (sk->sk_family != PF_RDS) {
1562 			ret = -EOPNOTSUPP;
1563 		}
1564 		if (!ret) {
1565 			if (val < 0 || val > 1)
1566 				ret = -EINVAL;
1567 			else
1568 				sock_valbool_flag(sk, SOCK_ZEROCOPY, valbool);
1569 		}
1570 		break;
1571 
1572 	case SO_TXTIME:
1573 		if (optlen != sizeof(struct sock_txtime)) {
1574 			ret = -EINVAL;
1575 			break;
1576 		} else if (copy_from_sockptr(&sk_txtime, optval,
1577 			   sizeof(struct sock_txtime))) {
1578 			ret = -EFAULT;
1579 			break;
1580 		} else if (sk_txtime.flags & ~SOF_TXTIME_FLAGS_MASK) {
1581 			ret = -EINVAL;
1582 			break;
1583 		}
1584 		/* CLOCK_MONOTONIC is only used by sch_fq, and this packet
1585 		 * scheduler has enough safe guards.
1586 		 */
1587 		if (sk_txtime.clockid != CLOCK_MONOTONIC &&
1588 		    !sockopt_ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) {
1589 			ret = -EPERM;
1590 			break;
1591 		}
1592 
1593 		ret = sockopt_validate_clockid(sk_txtime.clockid);
1594 		if (ret)
1595 			break;
1596 
1597 		sock_valbool_flag(sk, SOCK_TXTIME, true);
1598 		sk->sk_clockid = sk_txtime.clockid;
1599 		sk->sk_txtime_deadline_mode =
1600 			!!(sk_txtime.flags & SOF_TXTIME_DEADLINE_MODE);
1601 		sk->sk_txtime_report_errors =
1602 			!!(sk_txtime.flags & SOF_TXTIME_REPORT_ERRORS);
1603 		break;
1604 
1605 	case SO_BINDTOIFINDEX:
1606 		ret = sock_bindtoindex_locked(sk, val);
1607 		break;
1608 
1609 	case SO_BUF_LOCK:
1610 		if (val & ~SOCK_BUF_LOCK_MASK) {
1611 			ret = -EINVAL;
1612 			break;
1613 		}
1614 		sk->sk_userlocks = val | (sk->sk_userlocks &
1615 					  ~SOCK_BUF_LOCK_MASK);
1616 		break;
1617 
1618 	case SO_RESERVE_MEM:
1619 	{
1620 		int delta;
1621 
1622 		if (val < 0) {
1623 			ret = -EINVAL;
1624 			break;
1625 		}
1626 
1627 		delta = val - sk->sk_reserved_mem;
1628 		if (delta < 0)
1629 			sock_release_reserved_memory(sk, -delta);
1630 		else
1631 			ret = sock_reserve_memory(sk, delta);
1632 		break;
1633 	}
1634 
1635 	default:
1636 		ret = -ENOPROTOOPT;
1637 		break;
1638 	}
1639 	sockopt_release_sock(sk);
1640 	return ret;
1641 }
1642 
1643 int sock_setsockopt(struct socket *sock, int level, int optname,
1644 		    sockptr_t optval, unsigned int optlen)
1645 {
1646 	return sk_setsockopt(sock->sk, level, optname,
1647 			     optval, optlen);
1648 }
1649 EXPORT_SYMBOL(sock_setsockopt);
1650 
1651 static const struct cred *sk_get_peer_cred(struct sock *sk)
1652 {
1653 	const struct cred *cred;
1654 
1655 	spin_lock(&sk->sk_peer_lock);
1656 	cred = get_cred(sk->sk_peer_cred);
1657 	spin_unlock(&sk->sk_peer_lock);
1658 
1659 	return cred;
1660 }
1661 
1662 static void cred_to_ucred(struct pid *pid, const struct cred *cred,
1663 			  struct ucred *ucred)
1664 {
1665 	ucred->pid = pid_vnr(pid);
1666 	ucred->uid = ucred->gid = -1;
1667 	if (cred) {
1668 		struct user_namespace *current_ns = current_user_ns();
1669 
1670 		ucred->uid = from_kuid_munged(current_ns, cred->euid);
1671 		ucred->gid = from_kgid_munged(current_ns, cred->egid);
1672 	}
1673 }
1674 
1675 static int groups_to_user(sockptr_t dst, const struct group_info *src)
1676 {
1677 	struct user_namespace *user_ns = current_user_ns();
1678 	int i;
1679 
1680 	for (i = 0; i < src->ngroups; i++) {
1681 		gid_t gid = from_kgid_munged(user_ns, src->gid[i]);
1682 
1683 		if (copy_to_sockptr_offset(dst, i * sizeof(gid), &gid, sizeof(gid)))
1684 			return -EFAULT;
1685 	}
1686 
1687 	return 0;
1688 }
1689 
1690 int sk_getsockopt(struct sock *sk, int level, int optname,
1691 		  sockptr_t optval, sockptr_t optlen)
1692 {
1693 	struct socket *sock = sk->sk_socket;
1694 
1695 	union {
1696 		int val;
1697 		u64 val64;
1698 		unsigned long ulval;
1699 		struct linger ling;
1700 		struct old_timeval32 tm32;
1701 		struct __kernel_old_timeval tm;
1702 		struct  __kernel_sock_timeval stm;
1703 		struct sock_txtime txtime;
1704 		struct so_timestamping timestamping;
1705 	} v;
1706 
1707 	int lv = sizeof(int);
1708 	int len;
1709 
1710 	if (copy_from_sockptr(&len, optlen, sizeof(int)))
1711 		return -EFAULT;
1712 	if (len < 0)
1713 		return -EINVAL;
1714 
1715 	memset(&v, 0, sizeof(v));
1716 
1717 	switch (optname) {
1718 	case SO_DEBUG:
1719 		v.val = sock_flag(sk, SOCK_DBG);
1720 		break;
1721 
1722 	case SO_DONTROUTE:
1723 		v.val = sock_flag(sk, SOCK_LOCALROUTE);
1724 		break;
1725 
1726 	case SO_BROADCAST:
1727 		v.val = sock_flag(sk, SOCK_BROADCAST);
1728 		break;
1729 
1730 	case SO_SNDBUF:
1731 		v.val = READ_ONCE(sk->sk_sndbuf);
1732 		break;
1733 
1734 	case SO_RCVBUF:
1735 		v.val = READ_ONCE(sk->sk_rcvbuf);
1736 		break;
1737 
1738 	case SO_REUSEADDR:
1739 		v.val = sk->sk_reuse;
1740 		break;
1741 
1742 	case SO_REUSEPORT:
1743 		v.val = sk->sk_reuseport;
1744 		break;
1745 
1746 	case SO_KEEPALIVE:
1747 		v.val = sock_flag(sk, SOCK_KEEPOPEN);
1748 		break;
1749 
1750 	case SO_TYPE:
1751 		v.val = sk->sk_type;
1752 		break;
1753 
1754 	case SO_PROTOCOL:
1755 		v.val = sk->sk_protocol;
1756 		break;
1757 
1758 	case SO_DOMAIN:
1759 		v.val = sk->sk_family;
1760 		break;
1761 
1762 	case SO_ERROR:
1763 		v.val = -sock_error(sk);
1764 		if (v.val == 0)
1765 			v.val = xchg(&sk->sk_err_soft, 0);
1766 		break;
1767 
1768 	case SO_OOBINLINE:
1769 		v.val = sock_flag(sk, SOCK_URGINLINE);
1770 		break;
1771 
1772 	case SO_NO_CHECK:
1773 		v.val = sk->sk_no_check_tx;
1774 		break;
1775 
1776 	case SO_PRIORITY:
1777 		v.val = READ_ONCE(sk->sk_priority);
1778 		break;
1779 
1780 	case SO_LINGER:
1781 		lv		= sizeof(v.ling);
1782 		v.ling.l_onoff	= sock_flag(sk, SOCK_LINGER);
1783 		v.ling.l_linger	= READ_ONCE(sk->sk_lingertime) / HZ;
1784 		break;
1785 
1786 	case SO_BSDCOMPAT:
1787 		break;
1788 
1789 	case SO_TIMESTAMP_OLD:
1790 		v.val = sock_flag(sk, SOCK_RCVTSTAMP) &&
1791 				!sock_flag(sk, SOCK_TSTAMP_NEW) &&
1792 				!sock_flag(sk, SOCK_RCVTSTAMPNS);
1793 		break;
1794 
1795 	case SO_TIMESTAMPNS_OLD:
1796 		v.val = sock_flag(sk, SOCK_RCVTSTAMPNS) && !sock_flag(sk, SOCK_TSTAMP_NEW);
1797 		break;
1798 
1799 	case SO_TIMESTAMP_NEW:
1800 		v.val = sock_flag(sk, SOCK_RCVTSTAMP) && sock_flag(sk, SOCK_TSTAMP_NEW);
1801 		break;
1802 
1803 	case SO_TIMESTAMPNS_NEW:
1804 		v.val = sock_flag(sk, SOCK_RCVTSTAMPNS) && sock_flag(sk, SOCK_TSTAMP_NEW);
1805 		break;
1806 
1807 	case SO_TIMESTAMPING_OLD:
1808 	case SO_TIMESTAMPING_NEW:
1809 		lv = sizeof(v.timestamping);
1810 		/* For the later-added case SO_TIMESTAMPING_NEW: Be strict about only
1811 		 * returning the flags when they were set through the same option.
1812 		 * Don't change the beviour for the old case SO_TIMESTAMPING_OLD.
1813 		 */
1814 		if (optname == SO_TIMESTAMPING_OLD || sock_flag(sk, SOCK_TSTAMP_NEW)) {
1815 			v.timestamping.flags = READ_ONCE(sk->sk_tsflags);
1816 			v.timestamping.bind_phc = READ_ONCE(sk->sk_bind_phc);
1817 		}
1818 		break;
1819 
1820 	case SO_RCVTIMEO_OLD:
1821 	case SO_RCVTIMEO_NEW:
1822 		lv = sock_get_timeout(READ_ONCE(sk->sk_rcvtimeo), &v,
1823 				      SO_RCVTIMEO_OLD == optname);
1824 		break;
1825 
1826 	case SO_SNDTIMEO_OLD:
1827 	case SO_SNDTIMEO_NEW:
1828 		lv = sock_get_timeout(READ_ONCE(sk->sk_sndtimeo), &v,
1829 				      SO_SNDTIMEO_OLD == optname);
1830 		break;
1831 
1832 	case SO_RCVLOWAT:
1833 		v.val = READ_ONCE(sk->sk_rcvlowat);
1834 		break;
1835 
1836 	case SO_SNDLOWAT:
1837 		v.val = 1;
1838 		break;
1839 
1840 	case SO_PASSCRED:
1841 		v.val = !!test_bit(SOCK_PASSCRED, &sock->flags);
1842 		break;
1843 
1844 	case SO_PASSPIDFD:
1845 		v.val = !!test_bit(SOCK_PASSPIDFD, &sock->flags);
1846 		break;
1847 
1848 	case SO_PEERCRED:
1849 	{
1850 		struct ucred peercred;
1851 		if (len > sizeof(peercred))
1852 			len = sizeof(peercred);
1853 
1854 		spin_lock(&sk->sk_peer_lock);
1855 		cred_to_ucred(sk->sk_peer_pid, sk->sk_peer_cred, &peercred);
1856 		spin_unlock(&sk->sk_peer_lock);
1857 
1858 		if (copy_to_sockptr(optval, &peercred, len))
1859 			return -EFAULT;
1860 		goto lenout;
1861 	}
1862 
1863 	case SO_PEERPIDFD:
1864 	{
1865 		struct pid *peer_pid;
1866 		struct file *pidfd_file = NULL;
1867 		int pidfd;
1868 
1869 		if (len > sizeof(pidfd))
1870 			len = sizeof(pidfd);
1871 
1872 		spin_lock(&sk->sk_peer_lock);
1873 		peer_pid = get_pid(sk->sk_peer_pid);
1874 		spin_unlock(&sk->sk_peer_lock);
1875 
1876 		if (!peer_pid)
1877 			return -ENODATA;
1878 
1879 		pidfd = pidfd_prepare(peer_pid, 0, &pidfd_file);
1880 		put_pid(peer_pid);
1881 		if (pidfd < 0)
1882 			return pidfd;
1883 
1884 		if (copy_to_sockptr(optval, &pidfd, len) ||
1885 		    copy_to_sockptr(optlen, &len, sizeof(int))) {
1886 			put_unused_fd(pidfd);
1887 			fput(pidfd_file);
1888 
1889 			return -EFAULT;
1890 		}
1891 
1892 		fd_install(pidfd, pidfd_file);
1893 		return 0;
1894 	}
1895 
1896 	case SO_PEERGROUPS:
1897 	{
1898 		const struct cred *cred;
1899 		int ret, n;
1900 
1901 		cred = sk_get_peer_cred(sk);
1902 		if (!cred)
1903 			return -ENODATA;
1904 
1905 		n = cred->group_info->ngroups;
1906 		if (len < n * sizeof(gid_t)) {
1907 			len = n * sizeof(gid_t);
1908 			put_cred(cred);
1909 			return copy_to_sockptr(optlen, &len, sizeof(int)) ? -EFAULT : -ERANGE;
1910 		}
1911 		len = n * sizeof(gid_t);
1912 
1913 		ret = groups_to_user(optval, cred->group_info);
1914 		put_cred(cred);
1915 		if (ret)
1916 			return ret;
1917 		goto lenout;
1918 	}
1919 
1920 	case SO_PEERNAME:
1921 	{
1922 		struct sockaddr_storage address;
1923 
1924 		lv = READ_ONCE(sock->ops)->getname(sock, (struct sockaddr *)&address, 2);
1925 		if (lv < 0)
1926 			return -ENOTCONN;
1927 		if (lv < len)
1928 			return -EINVAL;
1929 		if (copy_to_sockptr(optval, &address, len))
1930 			return -EFAULT;
1931 		goto lenout;
1932 	}
1933 
1934 	/* Dubious BSD thing... Probably nobody even uses it, but
1935 	 * the UNIX standard wants it for whatever reason... -DaveM
1936 	 */
1937 	case SO_ACCEPTCONN:
1938 		v.val = sk->sk_state == TCP_LISTEN;
1939 		break;
1940 
1941 	case SO_PASSSEC:
1942 		v.val = !!test_bit(SOCK_PASSSEC, &sock->flags);
1943 		break;
1944 
1945 	case SO_PEERSEC:
1946 		return security_socket_getpeersec_stream(sock,
1947 							 optval, optlen, len);
1948 
1949 	case SO_MARK:
1950 		v.val = READ_ONCE(sk->sk_mark);
1951 		break;
1952 
1953 	case SO_RCVMARK:
1954 		v.val = sock_flag(sk, SOCK_RCVMARK);
1955 		break;
1956 
1957 	case SO_RCVPRIORITY:
1958 		v.val = sock_flag(sk, SOCK_RCVPRIORITY);
1959 		break;
1960 
1961 	case SO_RXQ_OVFL:
1962 		v.val = sock_flag(sk, SOCK_RXQ_OVFL);
1963 		break;
1964 
1965 	case SO_WIFI_STATUS:
1966 		v.val = sock_flag(sk, SOCK_WIFI_STATUS);
1967 		break;
1968 
1969 	case SO_PEEK_OFF:
1970 		if (!READ_ONCE(sock->ops)->set_peek_off)
1971 			return -EOPNOTSUPP;
1972 
1973 		v.val = READ_ONCE(sk->sk_peek_off);
1974 		break;
1975 	case SO_NOFCS:
1976 		v.val = sock_flag(sk, SOCK_NOFCS);
1977 		break;
1978 
1979 	case SO_BINDTODEVICE:
1980 		return sock_getbindtodevice(sk, optval, optlen, len);
1981 
1982 	case SO_GET_FILTER:
1983 		len = sk_get_filter(sk, optval, len);
1984 		if (len < 0)
1985 			return len;
1986 
1987 		goto lenout;
1988 
1989 	case SO_LOCK_FILTER:
1990 		v.val = sock_flag(sk, SOCK_FILTER_LOCKED);
1991 		break;
1992 
1993 	case SO_BPF_EXTENSIONS:
1994 		v.val = bpf_tell_extensions();
1995 		break;
1996 
1997 	case SO_SELECT_ERR_QUEUE:
1998 		v.val = sock_flag(sk, SOCK_SELECT_ERR_QUEUE);
1999 		break;
2000 
2001 #ifdef CONFIG_NET_RX_BUSY_POLL
2002 	case SO_BUSY_POLL:
2003 		v.val = READ_ONCE(sk->sk_ll_usec);
2004 		break;
2005 	case SO_PREFER_BUSY_POLL:
2006 		v.val = READ_ONCE(sk->sk_prefer_busy_poll);
2007 		break;
2008 #endif
2009 
2010 	case SO_MAX_PACING_RATE:
2011 		/* The READ_ONCE() pair with the WRITE_ONCE() in sk_setsockopt() */
2012 		if (sizeof(v.ulval) != sizeof(v.val) && len >= sizeof(v.ulval)) {
2013 			lv = sizeof(v.ulval);
2014 			v.ulval = READ_ONCE(sk->sk_max_pacing_rate);
2015 		} else {
2016 			/* 32bit version */
2017 			v.val = min_t(unsigned long, ~0U,
2018 				      READ_ONCE(sk->sk_max_pacing_rate));
2019 		}
2020 		break;
2021 
2022 	case SO_INCOMING_CPU:
2023 		v.val = READ_ONCE(sk->sk_incoming_cpu);
2024 		break;
2025 
2026 	case SO_MEMINFO:
2027 	{
2028 		u32 meminfo[SK_MEMINFO_VARS];
2029 
2030 		sk_get_meminfo(sk, meminfo);
2031 
2032 		len = min_t(unsigned int, len, sizeof(meminfo));
2033 		if (copy_to_sockptr(optval, &meminfo, len))
2034 			return -EFAULT;
2035 
2036 		goto lenout;
2037 	}
2038 
2039 #ifdef CONFIG_NET_RX_BUSY_POLL
2040 	case SO_INCOMING_NAPI_ID:
2041 		v.val = READ_ONCE(sk->sk_napi_id);
2042 
2043 		/* aggregate non-NAPI IDs down to 0 */
2044 		if (v.val < MIN_NAPI_ID)
2045 			v.val = 0;
2046 
2047 		break;
2048 #endif
2049 
2050 	case SO_COOKIE:
2051 		lv = sizeof(u64);
2052 		if (len < lv)
2053 			return -EINVAL;
2054 		v.val64 = sock_gen_cookie(sk);
2055 		break;
2056 
2057 	case SO_ZEROCOPY:
2058 		v.val = sock_flag(sk, SOCK_ZEROCOPY);
2059 		break;
2060 
2061 	case SO_TXTIME:
2062 		lv = sizeof(v.txtime);
2063 		v.txtime.clockid = sk->sk_clockid;
2064 		v.txtime.flags |= sk->sk_txtime_deadline_mode ?
2065 				  SOF_TXTIME_DEADLINE_MODE : 0;
2066 		v.txtime.flags |= sk->sk_txtime_report_errors ?
2067 				  SOF_TXTIME_REPORT_ERRORS : 0;
2068 		break;
2069 
2070 	case SO_BINDTOIFINDEX:
2071 		v.val = READ_ONCE(sk->sk_bound_dev_if);
2072 		break;
2073 
2074 	case SO_NETNS_COOKIE:
2075 		lv = sizeof(u64);
2076 		if (len != lv)
2077 			return -EINVAL;
2078 		v.val64 = sock_net(sk)->net_cookie;
2079 		break;
2080 
2081 	case SO_BUF_LOCK:
2082 		v.val = sk->sk_userlocks & SOCK_BUF_LOCK_MASK;
2083 		break;
2084 
2085 	case SO_RESERVE_MEM:
2086 		v.val = READ_ONCE(sk->sk_reserved_mem);
2087 		break;
2088 
2089 	case SO_TXREHASH:
2090 		/* Paired with WRITE_ONCE() in sk_setsockopt() */
2091 		v.val = READ_ONCE(sk->sk_txrehash);
2092 		break;
2093 
2094 	default:
2095 		/* We implement the SO_SNDLOWAT etc to not be settable
2096 		 * (1003.1g 7).
2097 		 */
2098 		return -ENOPROTOOPT;
2099 	}
2100 
2101 	if (len > lv)
2102 		len = lv;
2103 	if (copy_to_sockptr(optval, &v, len))
2104 		return -EFAULT;
2105 lenout:
2106 	if (copy_to_sockptr(optlen, &len, sizeof(int)))
2107 		return -EFAULT;
2108 	return 0;
2109 }
2110 
2111 /*
2112  * Initialize an sk_lock.
2113  *
2114  * (We also register the sk_lock with the lock validator.)
2115  */
2116 static inline void sock_lock_init(struct sock *sk)
2117 {
2118 	if (sk->sk_kern_sock)
2119 		sock_lock_init_class_and_name(
2120 			sk,
2121 			af_family_kern_slock_key_strings[sk->sk_family],
2122 			af_family_kern_slock_keys + sk->sk_family,
2123 			af_family_kern_key_strings[sk->sk_family],
2124 			af_family_kern_keys + sk->sk_family);
2125 	else
2126 		sock_lock_init_class_and_name(
2127 			sk,
2128 			af_family_slock_key_strings[sk->sk_family],
2129 			af_family_slock_keys + sk->sk_family,
2130 			af_family_key_strings[sk->sk_family],
2131 			af_family_keys + sk->sk_family);
2132 }
2133 
2134 /*
2135  * Copy all fields from osk to nsk but nsk->sk_refcnt must not change yet,
2136  * even temporarily, because of RCU lookups. sk_node should also be left as is.
2137  * We must not copy fields between sk_dontcopy_begin and sk_dontcopy_end
2138  */
2139 static void sock_copy(struct sock *nsk, const struct sock *osk)
2140 {
2141 	const struct proto *prot = READ_ONCE(osk->sk_prot);
2142 #ifdef CONFIG_SECURITY_NETWORK
2143 	void *sptr = nsk->sk_security;
2144 #endif
2145 
2146 	/* If we move sk_tx_queue_mapping out of the private section,
2147 	 * we must check if sk_tx_queue_clear() is called after
2148 	 * sock_copy() in sk_clone_lock().
2149 	 */
2150 	BUILD_BUG_ON(offsetof(struct sock, sk_tx_queue_mapping) <
2151 		     offsetof(struct sock, sk_dontcopy_begin) ||
2152 		     offsetof(struct sock, sk_tx_queue_mapping) >=
2153 		     offsetof(struct sock, sk_dontcopy_end));
2154 
2155 	memcpy(nsk, osk, offsetof(struct sock, sk_dontcopy_begin));
2156 
2157 	unsafe_memcpy(&nsk->sk_dontcopy_end, &osk->sk_dontcopy_end,
2158 		      prot->obj_size - offsetof(struct sock, sk_dontcopy_end),
2159 		      /* alloc is larger than struct, see sk_prot_alloc() */);
2160 
2161 #ifdef CONFIG_SECURITY_NETWORK
2162 	nsk->sk_security = sptr;
2163 	security_sk_clone(osk, nsk);
2164 #endif
2165 }
2166 
2167 static struct sock *sk_prot_alloc(struct proto *prot, gfp_t priority,
2168 		int family)
2169 {
2170 	struct sock *sk;
2171 	struct kmem_cache *slab;
2172 
2173 	slab = prot->slab;
2174 	if (slab != NULL) {
2175 		sk = kmem_cache_alloc(slab, priority & ~__GFP_ZERO);
2176 		if (!sk)
2177 			return sk;
2178 		if (want_init_on_alloc(priority))
2179 			sk_prot_clear_nulls(sk, prot->obj_size);
2180 	} else
2181 		sk = kmalloc(prot->obj_size, priority);
2182 
2183 	if (sk != NULL) {
2184 		if (security_sk_alloc(sk, family, priority))
2185 			goto out_free;
2186 
2187 		if (!try_module_get(prot->owner))
2188 			goto out_free_sec;
2189 	}
2190 
2191 	return sk;
2192 
2193 out_free_sec:
2194 	security_sk_free(sk);
2195 out_free:
2196 	if (slab != NULL)
2197 		kmem_cache_free(slab, sk);
2198 	else
2199 		kfree(sk);
2200 	return NULL;
2201 }
2202 
2203 static void sk_prot_free(struct proto *prot, struct sock *sk)
2204 {
2205 	struct kmem_cache *slab;
2206 	struct module *owner;
2207 
2208 	owner = prot->owner;
2209 	slab = prot->slab;
2210 
2211 	cgroup_sk_free(&sk->sk_cgrp_data);
2212 	mem_cgroup_sk_free(sk);
2213 	security_sk_free(sk);
2214 	if (slab != NULL)
2215 		kmem_cache_free(slab, sk);
2216 	else
2217 		kfree(sk);
2218 	module_put(owner);
2219 }
2220 
2221 /**
2222  *	sk_alloc - All socket objects are allocated here
2223  *	@net: the applicable net namespace
2224  *	@family: protocol family
2225  *	@priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
2226  *	@prot: struct proto associated with this new sock instance
2227  *	@kern: is this to be a kernel socket?
2228  */
2229 struct sock *sk_alloc(struct net *net, int family, gfp_t priority,
2230 		      struct proto *prot, int kern)
2231 {
2232 	struct sock *sk;
2233 
2234 	sk = sk_prot_alloc(prot, priority | __GFP_ZERO, family);
2235 	if (sk) {
2236 		sk->sk_family = family;
2237 		/*
2238 		 * See comment in struct sock definition to understand
2239 		 * why we need sk_prot_creator -acme
2240 		 */
2241 		sk->sk_prot = sk->sk_prot_creator = prot;
2242 		sk->sk_kern_sock = kern;
2243 		sock_lock_init(sk);
2244 		sk->sk_net_refcnt = kern ? 0 : 1;
2245 		if (likely(sk->sk_net_refcnt)) {
2246 			get_net_track(net, &sk->ns_tracker, priority);
2247 			sock_inuse_add(net, 1);
2248 		} else {
2249 			__netns_tracker_alloc(net, &sk->ns_tracker,
2250 					      false, priority);
2251 		}
2252 
2253 		sock_net_set(sk, net);
2254 		refcount_set(&sk->sk_wmem_alloc, 1);
2255 
2256 		mem_cgroup_sk_alloc(sk);
2257 		cgroup_sk_alloc(&sk->sk_cgrp_data);
2258 		sock_update_classid(&sk->sk_cgrp_data);
2259 		sock_update_netprioidx(&sk->sk_cgrp_data);
2260 		sk_tx_queue_clear(sk);
2261 	}
2262 
2263 	return sk;
2264 }
2265 EXPORT_SYMBOL(sk_alloc);
2266 
2267 /* Sockets having SOCK_RCU_FREE will call this function after one RCU
2268  * grace period. This is the case for UDP sockets and TCP listeners.
2269  */
2270 static void __sk_destruct(struct rcu_head *head)
2271 {
2272 	struct sock *sk = container_of(head, struct sock, sk_rcu);
2273 	struct sk_filter *filter;
2274 
2275 	if (sk->sk_destruct)
2276 		sk->sk_destruct(sk);
2277 
2278 	filter = rcu_dereference_check(sk->sk_filter,
2279 				       refcount_read(&sk->sk_wmem_alloc) == 0);
2280 	if (filter) {
2281 		sk_filter_uncharge(sk, filter);
2282 		RCU_INIT_POINTER(sk->sk_filter, NULL);
2283 	}
2284 
2285 	sock_disable_timestamp(sk, SK_FLAGS_TIMESTAMP);
2286 
2287 #ifdef CONFIG_BPF_SYSCALL
2288 	bpf_sk_storage_free(sk);
2289 #endif
2290 
2291 	if (atomic_read(&sk->sk_omem_alloc))
2292 		pr_debug("%s: optmem leakage (%d bytes) detected\n",
2293 			 __func__, atomic_read(&sk->sk_omem_alloc));
2294 
2295 	if (sk->sk_frag.page) {
2296 		put_page(sk->sk_frag.page);
2297 		sk->sk_frag.page = NULL;
2298 	}
2299 
2300 	/* We do not need to acquire sk->sk_peer_lock, we are the last user. */
2301 	put_cred(sk->sk_peer_cred);
2302 	put_pid(sk->sk_peer_pid);
2303 
2304 	if (likely(sk->sk_net_refcnt))
2305 		put_net_track(sock_net(sk), &sk->ns_tracker);
2306 	else
2307 		__netns_tracker_free(sock_net(sk), &sk->ns_tracker, false);
2308 
2309 	sk_prot_free(sk->sk_prot_creator, sk);
2310 }
2311 
2312 void sk_destruct(struct sock *sk)
2313 {
2314 	bool use_call_rcu = sock_flag(sk, SOCK_RCU_FREE);
2315 
2316 	if (rcu_access_pointer(sk->sk_reuseport_cb)) {
2317 		reuseport_detach_sock(sk);
2318 		use_call_rcu = true;
2319 	}
2320 
2321 	if (use_call_rcu)
2322 		call_rcu(&sk->sk_rcu, __sk_destruct);
2323 	else
2324 		__sk_destruct(&sk->sk_rcu);
2325 }
2326 
2327 static void __sk_free(struct sock *sk)
2328 {
2329 	if (likely(sk->sk_net_refcnt))
2330 		sock_inuse_add(sock_net(sk), -1);
2331 
2332 	if (unlikely(sk->sk_net_refcnt && sock_diag_has_destroy_listeners(sk)))
2333 		sock_diag_broadcast_destroy(sk);
2334 	else
2335 		sk_destruct(sk);
2336 }
2337 
2338 void sk_free(struct sock *sk)
2339 {
2340 	/*
2341 	 * We subtract one from sk_wmem_alloc and can know if
2342 	 * some packets are still in some tx queue.
2343 	 * If not null, sock_wfree() will call __sk_free(sk) later
2344 	 */
2345 	if (refcount_dec_and_test(&sk->sk_wmem_alloc))
2346 		__sk_free(sk);
2347 }
2348 EXPORT_SYMBOL(sk_free);
2349 
2350 static void sk_init_common(struct sock *sk)
2351 {
2352 	skb_queue_head_init(&sk->sk_receive_queue);
2353 	skb_queue_head_init(&sk->sk_write_queue);
2354 	skb_queue_head_init(&sk->sk_error_queue);
2355 
2356 	rwlock_init(&sk->sk_callback_lock);
2357 	lockdep_set_class_and_name(&sk->sk_receive_queue.lock,
2358 			af_rlock_keys + sk->sk_family,
2359 			af_family_rlock_key_strings[sk->sk_family]);
2360 	lockdep_set_class_and_name(&sk->sk_write_queue.lock,
2361 			af_wlock_keys + sk->sk_family,
2362 			af_family_wlock_key_strings[sk->sk_family]);
2363 	lockdep_set_class_and_name(&sk->sk_error_queue.lock,
2364 			af_elock_keys + sk->sk_family,
2365 			af_family_elock_key_strings[sk->sk_family]);
2366 	if (sk->sk_kern_sock)
2367 		lockdep_set_class_and_name(&sk->sk_callback_lock,
2368 			af_kern_callback_keys + sk->sk_family,
2369 			af_family_kern_clock_key_strings[sk->sk_family]);
2370 	else
2371 		lockdep_set_class_and_name(&sk->sk_callback_lock,
2372 			af_callback_keys + sk->sk_family,
2373 			af_family_clock_key_strings[sk->sk_family]);
2374 }
2375 
2376 /**
2377  *	sk_clone_lock - clone a socket, and lock its clone
2378  *	@sk: the socket to clone
2379  *	@priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
2380  *
2381  *	Caller must unlock socket even in error path (bh_unlock_sock(newsk))
2382  */
2383 struct sock *sk_clone_lock(const struct sock *sk, const gfp_t priority)
2384 {
2385 	struct proto *prot = READ_ONCE(sk->sk_prot);
2386 	struct sk_filter *filter;
2387 	bool is_charged = true;
2388 	struct sock *newsk;
2389 
2390 	newsk = sk_prot_alloc(prot, priority, sk->sk_family);
2391 	if (!newsk)
2392 		goto out;
2393 
2394 	sock_copy(newsk, sk);
2395 
2396 	newsk->sk_prot_creator = prot;
2397 
2398 	/* SANITY */
2399 	if (likely(newsk->sk_net_refcnt)) {
2400 		get_net_track(sock_net(newsk), &newsk->ns_tracker, priority);
2401 		sock_inuse_add(sock_net(newsk), 1);
2402 	} else {
2403 		/* Kernel sockets are not elevating the struct net refcount.
2404 		 * Instead, use a tracker to more easily detect if a layer
2405 		 * is not properly dismantling its kernel sockets at netns
2406 		 * destroy time.
2407 		 */
2408 		__netns_tracker_alloc(sock_net(newsk), &newsk->ns_tracker,
2409 				      false, priority);
2410 	}
2411 	sk_node_init(&newsk->sk_node);
2412 	sock_lock_init(newsk);
2413 	bh_lock_sock(newsk);
2414 	newsk->sk_backlog.head	= newsk->sk_backlog.tail = NULL;
2415 	newsk->sk_backlog.len = 0;
2416 
2417 	atomic_set(&newsk->sk_rmem_alloc, 0);
2418 
2419 	/* sk_wmem_alloc set to one (see sk_free() and sock_wfree()) */
2420 	refcount_set(&newsk->sk_wmem_alloc, 1);
2421 
2422 	atomic_set(&newsk->sk_omem_alloc, 0);
2423 	sk_init_common(newsk);
2424 
2425 	newsk->sk_dst_cache	= NULL;
2426 	newsk->sk_dst_pending_confirm = 0;
2427 	newsk->sk_wmem_queued	= 0;
2428 	newsk->sk_forward_alloc = 0;
2429 	newsk->sk_reserved_mem  = 0;
2430 	atomic_set(&newsk->sk_drops, 0);
2431 	newsk->sk_send_head	= NULL;
2432 	newsk->sk_userlocks	= sk->sk_userlocks & ~SOCK_BINDPORT_LOCK;
2433 	atomic_set(&newsk->sk_zckey, 0);
2434 
2435 	sock_reset_flag(newsk, SOCK_DONE);
2436 
2437 	/* sk->sk_memcg will be populated at accept() time */
2438 	newsk->sk_memcg = NULL;
2439 
2440 	cgroup_sk_clone(&newsk->sk_cgrp_data);
2441 
2442 	rcu_read_lock();
2443 	filter = rcu_dereference(sk->sk_filter);
2444 	if (filter != NULL)
2445 		/* though it's an empty new sock, the charging may fail
2446 		 * if sysctl_optmem_max was changed between creation of
2447 		 * original socket and cloning
2448 		 */
2449 		is_charged = sk_filter_charge(newsk, filter);
2450 	RCU_INIT_POINTER(newsk->sk_filter, filter);
2451 	rcu_read_unlock();
2452 
2453 	if (unlikely(!is_charged || xfrm_sk_clone_policy(newsk, sk))) {
2454 		/* We need to make sure that we don't uncharge the new
2455 		 * socket if we couldn't charge it in the first place
2456 		 * as otherwise we uncharge the parent's filter.
2457 		 */
2458 		if (!is_charged)
2459 			RCU_INIT_POINTER(newsk->sk_filter, NULL);
2460 		sk_free_unlock_clone(newsk);
2461 		newsk = NULL;
2462 		goto out;
2463 	}
2464 	RCU_INIT_POINTER(newsk->sk_reuseport_cb, NULL);
2465 
2466 	if (bpf_sk_storage_clone(sk, newsk)) {
2467 		sk_free_unlock_clone(newsk);
2468 		newsk = NULL;
2469 		goto out;
2470 	}
2471 
2472 	/* Clear sk_user_data if parent had the pointer tagged
2473 	 * as not suitable for copying when cloning.
2474 	 */
2475 	if (sk_user_data_is_nocopy(newsk))
2476 		newsk->sk_user_data = NULL;
2477 
2478 	newsk->sk_err	   = 0;
2479 	newsk->sk_err_soft = 0;
2480 	newsk->sk_priority = 0;
2481 	newsk->sk_incoming_cpu = raw_smp_processor_id();
2482 
2483 	/* Before updating sk_refcnt, we must commit prior changes to memory
2484 	 * (Documentation/RCU/rculist_nulls.rst for details)
2485 	 */
2486 	smp_wmb();
2487 	refcount_set(&newsk->sk_refcnt, 2);
2488 
2489 	sk_set_socket(newsk, NULL);
2490 	sk_tx_queue_clear(newsk);
2491 	RCU_INIT_POINTER(newsk->sk_wq, NULL);
2492 
2493 	if (newsk->sk_prot->sockets_allocated)
2494 		sk_sockets_allocated_inc(newsk);
2495 
2496 	if (sock_needs_netstamp(sk) && newsk->sk_flags & SK_FLAGS_TIMESTAMP)
2497 		net_enable_timestamp();
2498 out:
2499 	return newsk;
2500 }
2501 EXPORT_SYMBOL_GPL(sk_clone_lock);
2502 
2503 void sk_free_unlock_clone(struct sock *sk)
2504 {
2505 	/* It is still raw copy of parent, so invalidate
2506 	 * destructor and make plain sk_free() */
2507 	sk->sk_destruct = NULL;
2508 	bh_unlock_sock(sk);
2509 	sk_free(sk);
2510 }
2511 EXPORT_SYMBOL_GPL(sk_free_unlock_clone);
2512 
2513 static u32 sk_dst_gso_max_size(struct sock *sk, struct dst_entry *dst)
2514 {
2515 	bool is_ipv6 = false;
2516 	u32 max_size;
2517 
2518 #if IS_ENABLED(CONFIG_IPV6)
2519 	is_ipv6 = (sk->sk_family == AF_INET6 &&
2520 		   !ipv6_addr_v4mapped(&sk->sk_v6_rcv_saddr));
2521 #endif
2522 	/* pairs with the WRITE_ONCE() in netif_set_gso(_ipv4)_max_size() */
2523 	max_size = is_ipv6 ? READ_ONCE(dst->dev->gso_max_size) :
2524 			READ_ONCE(dst->dev->gso_ipv4_max_size);
2525 	if (max_size > GSO_LEGACY_MAX_SIZE && !sk_is_tcp(sk))
2526 		max_size = GSO_LEGACY_MAX_SIZE;
2527 
2528 	return max_size - (MAX_TCP_HEADER + 1);
2529 }
2530 
2531 void sk_setup_caps(struct sock *sk, struct dst_entry *dst)
2532 {
2533 	u32 max_segs = 1;
2534 
2535 	sk->sk_route_caps = dst->dev->features;
2536 	if (sk_is_tcp(sk))
2537 		sk->sk_route_caps |= NETIF_F_GSO;
2538 	if (sk->sk_route_caps & NETIF_F_GSO)
2539 		sk->sk_route_caps |= NETIF_F_GSO_SOFTWARE;
2540 	if (unlikely(sk->sk_gso_disabled))
2541 		sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
2542 	if (sk_can_gso(sk)) {
2543 		if (dst->header_len && !xfrm_dst_offload_ok(dst)) {
2544 			sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
2545 		} else {
2546 			sk->sk_route_caps |= NETIF_F_SG | NETIF_F_HW_CSUM;
2547 			sk->sk_gso_max_size = sk_dst_gso_max_size(sk, dst);
2548 			/* pairs with the WRITE_ONCE() in netif_set_gso_max_segs() */
2549 			max_segs = max_t(u32, READ_ONCE(dst->dev->gso_max_segs), 1);
2550 		}
2551 	}
2552 	sk->sk_gso_max_segs = max_segs;
2553 	sk_dst_set(sk, dst);
2554 }
2555 EXPORT_SYMBOL_GPL(sk_setup_caps);
2556 
2557 /*
2558  *	Simple resource managers for sockets.
2559  */
2560 
2561 
2562 /*
2563  * Write buffer destructor automatically called from kfree_skb.
2564  */
2565 void sock_wfree(struct sk_buff *skb)
2566 {
2567 	struct sock *sk = skb->sk;
2568 	unsigned int len = skb->truesize;
2569 	bool free;
2570 
2571 	if (!sock_flag(sk, SOCK_USE_WRITE_QUEUE)) {
2572 		if (sock_flag(sk, SOCK_RCU_FREE) &&
2573 		    sk->sk_write_space == sock_def_write_space) {
2574 			rcu_read_lock();
2575 			free = refcount_sub_and_test(len, &sk->sk_wmem_alloc);
2576 			sock_def_write_space_wfree(sk);
2577 			rcu_read_unlock();
2578 			if (unlikely(free))
2579 				__sk_free(sk);
2580 			return;
2581 		}
2582 
2583 		/*
2584 		 * Keep a reference on sk_wmem_alloc, this will be released
2585 		 * after sk_write_space() call
2586 		 */
2587 		WARN_ON(refcount_sub_and_test(len - 1, &sk->sk_wmem_alloc));
2588 		sk->sk_write_space(sk);
2589 		len = 1;
2590 	}
2591 	/*
2592 	 * if sk_wmem_alloc reaches 0, we must finish what sk_free()
2593 	 * could not do because of in-flight packets
2594 	 */
2595 	if (refcount_sub_and_test(len, &sk->sk_wmem_alloc))
2596 		__sk_free(sk);
2597 }
2598 EXPORT_SYMBOL(sock_wfree);
2599 
2600 /* This variant of sock_wfree() is used by TCP,
2601  * since it sets SOCK_USE_WRITE_QUEUE.
2602  */
2603 void __sock_wfree(struct sk_buff *skb)
2604 {
2605 	struct sock *sk = skb->sk;
2606 
2607 	if (refcount_sub_and_test(skb->truesize, &sk->sk_wmem_alloc))
2608 		__sk_free(sk);
2609 }
2610 
2611 void skb_set_owner_w(struct sk_buff *skb, struct sock *sk)
2612 {
2613 	skb_orphan(skb);
2614 #ifdef CONFIG_INET
2615 	if (unlikely(!sk_fullsock(sk)))
2616 		return skb_set_owner_edemux(skb, sk);
2617 #endif
2618 	skb->sk = sk;
2619 	skb->destructor = sock_wfree;
2620 	skb_set_hash_from_sk(skb, sk);
2621 	/*
2622 	 * We used to take a refcount on sk, but following operation
2623 	 * is enough to guarantee sk_free() won't free this sock until
2624 	 * all in-flight packets are completed
2625 	 */
2626 	refcount_add(skb->truesize, &sk->sk_wmem_alloc);
2627 }
2628 EXPORT_SYMBOL(skb_set_owner_w);
2629 
2630 static bool can_skb_orphan_partial(const struct sk_buff *skb)
2631 {
2632 	/* Drivers depend on in-order delivery for crypto offload,
2633 	 * partial orphan breaks out-of-order-OK logic.
2634 	 */
2635 	if (skb_is_decrypted(skb))
2636 		return false;
2637 
2638 	return (skb->destructor == sock_wfree ||
2639 		(IS_ENABLED(CONFIG_INET) && skb->destructor == tcp_wfree));
2640 }
2641 
2642 /* This helper is used by netem, as it can hold packets in its
2643  * delay queue. We want to allow the owner socket to send more
2644  * packets, as if they were already TX completed by a typical driver.
2645  * But we also want to keep skb->sk set because some packet schedulers
2646  * rely on it (sch_fq for example).
2647  */
2648 void skb_orphan_partial(struct sk_buff *skb)
2649 {
2650 	if (skb_is_tcp_pure_ack(skb))
2651 		return;
2652 
2653 	if (can_skb_orphan_partial(skb) && skb_set_owner_sk_safe(skb, skb->sk))
2654 		return;
2655 
2656 	skb_orphan(skb);
2657 }
2658 EXPORT_SYMBOL(skb_orphan_partial);
2659 
2660 /*
2661  * Read buffer destructor automatically called from kfree_skb.
2662  */
2663 void sock_rfree(struct sk_buff *skb)
2664 {
2665 	struct sock *sk = skb->sk;
2666 	unsigned int len = skb->truesize;
2667 
2668 	atomic_sub(len, &sk->sk_rmem_alloc);
2669 	sk_mem_uncharge(sk, len);
2670 }
2671 EXPORT_SYMBOL(sock_rfree);
2672 
2673 /*
2674  * Buffer destructor for skbs that are not used directly in read or write
2675  * path, e.g. for error handler skbs. Automatically called from kfree_skb.
2676  */
2677 void sock_efree(struct sk_buff *skb)
2678 {
2679 	sock_put(skb->sk);
2680 }
2681 EXPORT_SYMBOL(sock_efree);
2682 
2683 /* Buffer destructor for prefetch/receive path where reference count may
2684  * not be held, e.g. for listen sockets.
2685  */
2686 #ifdef CONFIG_INET
2687 void sock_pfree(struct sk_buff *skb)
2688 {
2689 	struct sock *sk = skb->sk;
2690 
2691 	if (!sk_is_refcounted(sk))
2692 		return;
2693 
2694 	if (sk->sk_state == TCP_NEW_SYN_RECV && inet_reqsk(sk)->syncookie) {
2695 		inet_reqsk(sk)->rsk_listener = NULL;
2696 		reqsk_free(inet_reqsk(sk));
2697 		return;
2698 	}
2699 
2700 	sock_gen_put(sk);
2701 }
2702 EXPORT_SYMBOL(sock_pfree);
2703 #endif /* CONFIG_INET */
2704 
2705 kuid_t sock_i_uid(struct sock *sk)
2706 {
2707 	kuid_t uid;
2708 
2709 	read_lock_bh(&sk->sk_callback_lock);
2710 	uid = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_uid : GLOBAL_ROOT_UID;
2711 	read_unlock_bh(&sk->sk_callback_lock);
2712 	return uid;
2713 }
2714 EXPORT_SYMBOL(sock_i_uid);
2715 
2716 unsigned long __sock_i_ino(struct sock *sk)
2717 {
2718 	unsigned long ino;
2719 
2720 	read_lock(&sk->sk_callback_lock);
2721 	ino = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_ino : 0;
2722 	read_unlock(&sk->sk_callback_lock);
2723 	return ino;
2724 }
2725 EXPORT_SYMBOL(__sock_i_ino);
2726 
2727 unsigned long sock_i_ino(struct sock *sk)
2728 {
2729 	unsigned long ino;
2730 
2731 	local_bh_disable();
2732 	ino = __sock_i_ino(sk);
2733 	local_bh_enable();
2734 	return ino;
2735 }
2736 EXPORT_SYMBOL(sock_i_ino);
2737 
2738 /*
2739  * Allocate a skb from the socket's send buffer.
2740  */
2741 struct sk_buff *sock_wmalloc(struct sock *sk, unsigned long size, int force,
2742 			     gfp_t priority)
2743 {
2744 	if (force ||
2745 	    refcount_read(&sk->sk_wmem_alloc) < READ_ONCE(sk->sk_sndbuf)) {
2746 		struct sk_buff *skb = alloc_skb(size, priority);
2747 
2748 		if (skb) {
2749 			skb_set_owner_w(skb, sk);
2750 			return skb;
2751 		}
2752 	}
2753 	return NULL;
2754 }
2755 EXPORT_SYMBOL(sock_wmalloc);
2756 
2757 static void sock_ofree(struct sk_buff *skb)
2758 {
2759 	struct sock *sk = skb->sk;
2760 
2761 	atomic_sub(skb->truesize, &sk->sk_omem_alloc);
2762 }
2763 
2764 struct sk_buff *sock_omalloc(struct sock *sk, unsigned long size,
2765 			     gfp_t priority)
2766 {
2767 	struct sk_buff *skb;
2768 
2769 	/* small safe race: SKB_TRUESIZE may differ from final skb->truesize */
2770 	if (atomic_read(&sk->sk_omem_alloc) + SKB_TRUESIZE(size) >
2771 	    READ_ONCE(sock_net(sk)->core.sysctl_optmem_max))
2772 		return NULL;
2773 
2774 	skb = alloc_skb(size, priority);
2775 	if (!skb)
2776 		return NULL;
2777 
2778 	atomic_add(skb->truesize, &sk->sk_omem_alloc);
2779 	skb->sk = sk;
2780 	skb->destructor = sock_ofree;
2781 	return skb;
2782 }
2783 
2784 /*
2785  * Allocate a memory block from the socket's option memory buffer.
2786  */
2787 void *sock_kmalloc(struct sock *sk, int size, gfp_t priority)
2788 {
2789 	int optmem_max = READ_ONCE(sock_net(sk)->core.sysctl_optmem_max);
2790 
2791 	if ((unsigned int)size <= optmem_max &&
2792 	    atomic_read(&sk->sk_omem_alloc) + size < optmem_max) {
2793 		void *mem;
2794 		/* First do the add, to avoid the race if kmalloc
2795 		 * might sleep.
2796 		 */
2797 		atomic_add(size, &sk->sk_omem_alloc);
2798 		mem = kmalloc(size, priority);
2799 		if (mem)
2800 			return mem;
2801 		atomic_sub(size, &sk->sk_omem_alloc);
2802 	}
2803 	return NULL;
2804 }
2805 EXPORT_SYMBOL(sock_kmalloc);
2806 
2807 /* Free an option memory block. Note, we actually want the inline
2808  * here as this allows gcc to detect the nullify and fold away the
2809  * condition entirely.
2810  */
2811 static inline void __sock_kfree_s(struct sock *sk, void *mem, int size,
2812 				  const bool nullify)
2813 {
2814 	if (WARN_ON_ONCE(!mem))
2815 		return;
2816 	if (nullify)
2817 		kfree_sensitive(mem);
2818 	else
2819 		kfree(mem);
2820 	atomic_sub(size, &sk->sk_omem_alloc);
2821 }
2822 
2823 void sock_kfree_s(struct sock *sk, void *mem, int size)
2824 {
2825 	__sock_kfree_s(sk, mem, size, false);
2826 }
2827 EXPORT_SYMBOL(sock_kfree_s);
2828 
2829 void sock_kzfree_s(struct sock *sk, void *mem, int size)
2830 {
2831 	__sock_kfree_s(sk, mem, size, true);
2832 }
2833 EXPORT_SYMBOL(sock_kzfree_s);
2834 
2835 /* It is almost wait_for_tcp_memory minus release_sock/lock_sock.
2836    I think, these locks should be removed for datagram sockets.
2837  */
2838 static long sock_wait_for_wmem(struct sock *sk, long timeo)
2839 {
2840 	DEFINE_WAIT(wait);
2841 
2842 	sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
2843 	for (;;) {
2844 		if (!timeo)
2845 			break;
2846 		if (signal_pending(current))
2847 			break;
2848 		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
2849 		prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
2850 		if (refcount_read(&sk->sk_wmem_alloc) < READ_ONCE(sk->sk_sndbuf))
2851 			break;
2852 		if (READ_ONCE(sk->sk_shutdown) & SEND_SHUTDOWN)
2853 			break;
2854 		if (READ_ONCE(sk->sk_err))
2855 			break;
2856 		timeo = schedule_timeout(timeo);
2857 	}
2858 	finish_wait(sk_sleep(sk), &wait);
2859 	return timeo;
2860 }
2861 
2862 
2863 /*
2864  *	Generic send/receive buffer handlers
2865  */
2866 
2867 struct sk_buff *sock_alloc_send_pskb(struct sock *sk, unsigned long header_len,
2868 				     unsigned long data_len, int noblock,
2869 				     int *errcode, int max_page_order)
2870 {
2871 	struct sk_buff *skb;
2872 	long timeo;
2873 	int err;
2874 
2875 	timeo = sock_sndtimeo(sk, noblock);
2876 	for (;;) {
2877 		err = sock_error(sk);
2878 		if (err != 0)
2879 			goto failure;
2880 
2881 		err = -EPIPE;
2882 		if (READ_ONCE(sk->sk_shutdown) & SEND_SHUTDOWN)
2883 			goto failure;
2884 
2885 		if (sk_wmem_alloc_get(sk) < READ_ONCE(sk->sk_sndbuf))
2886 			break;
2887 
2888 		sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
2889 		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
2890 		err = -EAGAIN;
2891 		if (!timeo)
2892 			goto failure;
2893 		if (signal_pending(current))
2894 			goto interrupted;
2895 		timeo = sock_wait_for_wmem(sk, timeo);
2896 	}
2897 	skb = alloc_skb_with_frags(header_len, data_len, max_page_order,
2898 				   errcode, sk->sk_allocation);
2899 	if (skb)
2900 		skb_set_owner_w(skb, sk);
2901 	return skb;
2902 
2903 interrupted:
2904 	err = sock_intr_errno(timeo);
2905 failure:
2906 	*errcode = err;
2907 	return NULL;
2908 }
2909 EXPORT_SYMBOL(sock_alloc_send_pskb);
2910 
2911 int __sock_cmsg_send(struct sock *sk, struct cmsghdr *cmsg,
2912 		     struct sockcm_cookie *sockc)
2913 {
2914 	u32 tsflags;
2915 
2916 	BUILD_BUG_ON(SOF_TIMESTAMPING_LAST == (1 << 31));
2917 
2918 	switch (cmsg->cmsg_type) {
2919 	case SO_MARK:
2920 		if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_RAW) &&
2921 		    !ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
2922 			return -EPERM;
2923 		if (cmsg->cmsg_len != CMSG_LEN(sizeof(u32)))
2924 			return -EINVAL;
2925 		sockc->mark = *(u32 *)CMSG_DATA(cmsg);
2926 		break;
2927 	case SO_TIMESTAMPING_OLD:
2928 	case SO_TIMESTAMPING_NEW:
2929 		if (cmsg->cmsg_len != CMSG_LEN(sizeof(u32)))
2930 			return -EINVAL;
2931 
2932 		tsflags = *(u32 *)CMSG_DATA(cmsg);
2933 		if (tsflags & ~SOF_TIMESTAMPING_TX_RECORD_MASK)
2934 			return -EINVAL;
2935 
2936 		sockc->tsflags &= ~SOF_TIMESTAMPING_TX_RECORD_MASK;
2937 		sockc->tsflags |= tsflags;
2938 		break;
2939 	case SCM_TXTIME:
2940 		if (!sock_flag(sk, SOCK_TXTIME))
2941 			return -EINVAL;
2942 		if (cmsg->cmsg_len != CMSG_LEN(sizeof(u64)))
2943 			return -EINVAL;
2944 		sockc->transmit_time = get_unaligned((u64 *)CMSG_DATA(cmsg));
2945 		break;
2946 	case SCM_TS_OPT_ID:
2947 		if (sk_is_tcp(sk))
2948 			return -EINVAL;
2949 		tsflags = READ_ONCE(sk->sk_tsflags);
2950 		if (!(tsflags & SOF_TIMESTAMPING_OPT_ID))
2951 			return -EINVAL;
2952 		if (cmsg->cmsg_len != CMSG_LEN(sizeof(u32)))
2953 			return -EINVAL;
2954 		sockc->ts_opt_id = *(u32 *)CMSG_DATA(cmsg);
2955 		sockc->tsflags |= SOCKCM_FLAG_TS_OPT_ID;
2956 		break;
2957 	/* SCM_RIGHTS and SCM_CREDENTIALS are semantically in SOL_UNIX. */
2958 	case SCM_RIGHTS:
2959 	case SCM_CREDENTIALS:
2960 		break;
2961 	case SO_PRIORITY:
2962 		if (cmsg->cmsg_len != CMSG_LEN(sizeof(u32)))
2963 			return -EINVAL;
2964 		if (!sk_set_prio_allowed(sk, *(u32 *)CMSG_DATA(cmsg)))
2965 			return -EPERM;
2966 		sockc->priority = *(u32 *)CMSG_DATA(cmsg);
2967 		break;
2968 	default:
2969 		return -EINVAL;
2970 	}
2971 	return 0;
2972 }
2973 EXPORT_SYMBOL(__sock_cmsg_send);
2974 
2975 int sock_cmsg_send(struct sock *sk, struct msghdr *msg,
2976 		   struct sockcm_cookie *sockc)
2977 {
2978 	struct cmsghdr *cmsg;
2979 	int ret;
2980 
2981 	for_each_cmsghdr(cmsg, msg) {
2982 		if (!CMSG_OK(msg, cmsg))
2983 			return -EINVAL;
2984 		if (cmsg->cmsg_level != SOL_SOCKET)
2985 			continue;
2986 		ret = __sock_cmsg_send(sk, cmsg, sockc);
2987 		if (ret)
2988 			return ret;
2989 	}
2990 	return 0;
2991 }
2992 EXPORT_SYMBOL(sock_cmsg_send);
2993 
2994 static void sk_enter_memory_pressure(struct sock *sk)
2995 {
2996 	if (!sk->sk_prot->enter_memory_pressure)
2997 		return;
2998 
2999 	sk->sk_prot->enter_memory_pressure(sk);
3000 }
3001 
3002 static void sk_leave_memory_pressure(struct sock *sk)
3003 {
3004 	if (sk->sk_prot->leave_memory_pressure) {
3005 		INDIRECT_CALL_INET_1(sk->sk_prot->leave_memory_pressure,
3006 				     tcp_leave_memory_pressure, sk);
3007 	} else {
3008 		unsigned long *memory_pressure = sk->sk_prot->memory_pressure;
3009 
3010 		if (memory_pressure && READ_ONCE(*memory_pressure))
3011 			WRITE_ONCE(*memory_pressure, 0);
3012 	}
3013 }
3014 
3015 DEFINE_STATIC_KEY_FALSE(net_high_order_alloc_disable_key);
3016 
3017 /**
3018  * skb_page_frag_refill - check that a page_frag contains enough room
3019  * @sz: minimum size of the fragment we want to get
3020  * @pfrag: pointer to page_frag
3021  * @gfp: priority for memory allocation
3022  *
3023  * Note: While this allocator tries to use high order pages, there is
3024  * no guarantee that allocations succeed. Therefore, @sz MUST be
3025  * less or equal than PAGE_SIZE.
3026  */
3027 bool skb_page_frag_refill(unsigned int sz, struct page_frag *pfrag, gfp_t gfp)
3028 {
3029 	if (pfrag->page) {
3030 		if (page_ref_count(pfrag->page) == 1) {
3031 			pfrag->offset = 0;
3032 			return true;
3033 		}
3034 		if (pfrag->offset + sz <= pfrag->size)
3035 			return true;
3036 		put_page(pfrag->page);
3037 	}
3038 
3039 	pfrag->offset = 0;
3040 	if (SKB_FRAG_PAGE_ORDER &&
3041 	    !static_branch_unlikely(&net_high_order_alloc_disable_key)) {
3042 		/* Avoid direct reclaim but allow kswapd to wake */
3043 		pfrag->page = alloc_pages((gfp & ~__GFP_DIRECT_RECLAIM) |
3044 					  __GFP_COMP | __GFP_NOWARN |
3045 					  __GFP_NORETRY,
3046 					  SKB_FRAG_PAGE_ORDER);
3047 		if (likely(pfrag->page)) {
3048 			pfrag->size = PAGE_SIZE << SKB_FRAG_PAGE_ORDER;
3049 			return true;
3050 		}
3051 	}
3052 	pfrag->page = alloc_page(gfp);
3053 	if (likely(pfrag->page)) {
3054 		pfrag->size = PAGE_SIZE;
3055 		return true;
3056 	}
3057 	return false;
3058 }
3059 EXPORT_SYMBOL(skb_page_frag_refill);
3060 
3061 bool sk_page_frag_refill(struct sock *sk, struct page_frag *pfrag)
3062 {
3063 	if (likely(skb_page_frag_refill(32U, pfrag, sk->sk_allocation)))
3064 		return true;
3065 
3066 	sk_enter_memory_pressure(sk);
3067 	sk_stream_moderate_sndbuf(sk);
3068 	return false;
3069 }
3070 EXPORT_SYMBOL(sk_page_frag_refill);
3071 
3072 void __lock_sock(struct sock *sk)
3073 	__releases(&sk->sk_lock.slock)
3074 	__acquires(&sk->sk_lock.slock)
3075 {
3076 	DEFINE_WAIT(wait);
3077 
3078 	for (;;) {
3079 		prepare_to_wait_exclusive(&sk->sk_lock.wq, &wait,
3080 					TASK_UNINTERRUPTIBLE);
3081 		spin_unlock_bh(&sk->sk_lock.slock);
3082 		schedule();
3083 		spin_lock_bh(&sk->sk_lock.slock);
3084 		if (!sock_owned_by_user(sk))
3085 			break;
3086 	}
3087 	finish_wait(&sk->sk_lock.wq, &wait);
3088 }
3089 
3090 void __release_sock(struct sock *sk)
3091 	__releases(&sk->sk_lock.slock)
3092 	__acquires(&sk->sk_lock.slock)
3093 {
3094 	struct sk_buff *skb, *next;
3095 
3096 	while ((skb = sk->sk_backlog.head) != NULL) {
3097 		sk->sk_backlog.head = sk->sk_backlog.tail = NULL;
3098 
3099 		spin_unlock_bh(&sk->sk_lock.slock);
3100 
3101 		do {
3102 			next = skb->next;
3103 			prefetch(next);
3104 			DEBUG_NET_WARN_ON_ONCE(skb_dst_is_noref(skb));
3105 			skb_mark_not_on_list(skb);
3106 			sk_backlog_rcv(sk, skb);
3107 
3108 			cond_resched();
3109 
3110 			skb = next;
3111 		} while (skb != NULL);
3112 
3113 		spin_lock_bh(&sk->sk_lock.slock);
3114 	}
3115 
3116 	/*
3117 	 * Doing the zeroing here guarantee we can not loop forever
3118 	 * while a wild producer attempts to flood us.
3119 	 */
3120 	sk->sk_backlog.len = 0;
3121 }
3122 
3123 void __sk_flush_backlog(struct sock *sk)
3124 {
3125 	spin_lock_bh(&sk->sk_lock.slock);
3126 	__release_sock(sk);
3127 
3128 	if (sk->sk_prot->release_cb)
3129 		INDIRECT_CALL_INET_1(sk->sk_prot->release_cb,
3130 				     tcp_release_cb, sk);
3131 
3132 	spin_unlock_bh(&sk->sk_lock.slock);
3133 }
3134 EXPORT_SYMBOL_GPL(__sk_flush_backlog);
3135 
3136 /**
3137  * sk_wait_data - wait for data to arrive at sk_receive_queue
3138  * @sk:    sock to wait on
3139  * @timeo: for how long
3140  * @skb:   last skb seen on sk_receive_queue
3141  *
3142  * Now socket state including sk->sk_err is changed only under lock,
3143  * hence we may omit checks after joining wait queue.
3144  * We check receive queue before schedule() only as optimization;
3145  * it is very likely that release_sock() added new data.
3146  */
3147 int sk_wait_data(struct sock *sk, long *timeo, const struct sk_buff *skb)
3148 {
3149 	DEFINE_WAIT_FUNC(wait, woken_wake_function);
3150 	int rc;
3151 
3152 	add_wait_queue(sk_sleep(sk), &wait);
3153 	sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
3154 	rc = sk_wait_event(sk, timeo, skb_peek_tail(&sk->sk_receive_queue) != skb, &wait);
3155 	sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
3156 	remove_wait_queue(sk_sleep(sk), &wait);
3157 	return rc;
3158 }
3159 EXPORT_SYMBOL(sk_wait_data);
3160 
3161 /**
3162  *	__sk_mem_raise_allocated - increase memory_allocated
3163  *	@sk: socket
3164  *	@size: memory size to allocate
3165  *	@amt: pages to allocate
3166  *	@kind: allocation type
3167  *
3168  *	Similar to __sk_mem_schedule(), but does not update sk_forward_alloc.
3169  *
3170  *	Unlike the globally shared limits among the sockets under same protocol,
3171  *	consuming the budget of a memcg won't have direct effect on other ones.
3172  *	So be optimistic about memcg's tolerance, and leave the callers to decide
3173  *	whether or not to raise allocated through sk_under_memory_pressure() or
3174  *	its variants.
3175  */
3176 int __sk_mem_raise_allocated(struct sock *sk, int size, int amt, int kind)
3177 {
3178 	struct mem_cgroup *memcg = mem_cgroup_sockets_enabled ? sk->sk_memcg : NULL;
3179 	struct proto *prot = sk->sk_prot;
3180 	bool charged = false;
3181 	long allocated;
3182 
3183 	sk_memory_allocated_add(sk, amt);
3184 	allocated = sk_memory_allocated(sk);
3185 
3186 	if (memcg) {
3187 		if (!mem_cgroup_charge_skmem(memcg, amt, gfp_memcg_charge()))
3188 			goto suppress_allocation;
3189 		charged = true;
3190 	}
3191 
3192 	/* Under limit. */
3193 	if (allocated <= sk_prot_mem_limits(sk, 0)) {
3194 		sk_leave_memory_pressure(sk);
3195 		return 1;
3196 	}
3197 
3198 	/* Under pressure. */
3199 	if (allocated > sk_prot_mem_limits(sk, 1))
3200 		sk_enter_memory_pressure(sk);
3201 
3202 	/* Over hard limit. */
3203 	if (allocated > sk_prot_mem_limits(sk, 2))
3204 		goto suppress_allocation;
3205 
3206 	/* Guarantee minimum buffer size under pressure (either global
3207 	 * or memcg) to make sure features described in RFC 7323 (TCP
3208 	 * Extensions for High Performance) work properly.
3209 	 *
3210 	 * This rule does NOT stand when exceeds global or memcg's hard
3211 	 * limit, or else a DoS attack can be taken place by spawning
3212 	 * lots of sockets whose usage are under minimum buffer size.
3213 	 */
3214 	if (kind == SK_MEM_RECV) {
3215 		if (atomic_read(&sk->sk_rmem_alloc) < sk_get_rmem0(sk, prot))
3216 			return 1;
3217 
3218 	} else { /* SK_MEM_SEND */
3219 		int wmem0 = sk_get_wmem0(sk, prot);
3220 
3221 		if (sk->sk_type == SOCK_STREAM) {
3222 			if (sk->sk_wmem_queued < wmem0)
3223 				return 1;
3224 		} else if (refcount_read(&sk->sk_wmem_alloc) < wmem0) {
3225 				return 1;
3226 		}
3227 	}
3228 
3229 	if (sk_has_memory_pressure(sk)) {
3230 		u64 alloc;
3231 
3232 		/* The following 'average' heuristic is within the
3233 		 * scope of global accounting, so it only makes
3234 		 * sense for global memory pressure.
3235 		 */
3236 		if (!sk_under_global_memory_pressure(sk))
3237 			return 1;
3238 
3239 		/* Try to be fair among all the sockets under global
3240 		 * pressure by allowing the ones that below average
3241 		 * usage to raise.
3242 		 */
3243 		alloc = sk_sockets_allocated_read_positive(sk);
3244 		if (sk_prot_mem_limits(sk, 2) > alloc *
3245 		    sk_mem_pages(sk->sk_wmem_queued +
3246 				 atomic_read(&sk->sk_rmem_alloc) +
3247 				 sk->sk_forward_alloc))
3248 			return 1;
3249 	}
3250 
3251 suppress_allocation:
3252 
3253 	if (kind == SK_MEM_SEND && sk->sk_type == SOCK_STREAM) {
3254 		sk_stream_moderate_sndbuf(sk);
3255 
3256 		/* Fail only if socket is _under_ its sndbuf.
3257 		 * In this case we cannot block, so that we have to fail.
3258 		 */
3259 		if (sk->sk_wmem_queued + size >= sk->sk_sndbuf) {
3260 			/* Force charge with __GFP_NOFAIL */
3261 			if (memcg && !charged) {
3262 				mem_cgroup_charge_skmem(memcg, amt,
3263 					gfp_memcg_charge() | __GFP_NOFAIL);
3264 			}
3265 			return 1;
3266 		}
3267 	}
3268 
3269 	if (kind == SK_MEM_SEND || (kind == SK_MEM_RECV && charged))
3270 		trace_sock_exceed_buf_limit(sk, prot, allocated, kind);
3271 
3272 	sk_memory_allocated_sub(sk, amt);
3273 
3274 	if (charged)
3275 		mem_cgroup_uncharge_skmem(memcg, amt);
3276 
3277 	return 0;
3278 }
3279 
3280 /**
3281  *	__sk_mem_schedule - increase sk_forward_alloc and memory_allocated
3282  *	@sk: socket
3283  *	@size: memory size to allocate
3284  *	@kind: allocation type
3285  *
3286  *	If kind is SK_MEM_SEND, it means wmem allocation. Otherwise it means
3287  *	rmem allocation. This function assumes that protocols which have
3288  *	memory_pressure use sk_wmem_queued as write buffer accounting.
3289  */
3290 int __sk_mem_schedule(struct sock *sk, int size, int kind)
3291 {
3292 	int ret, amt = sk_mem_pages(size);
3293 
3294 	sk_forward_alloc_add(sk, amt << PAGE_SHIFT);
3295 	ret = __sk_mem_raise_allocated(sk, size, amt, kind);
3296 	if (!ret)
3297 		sk_forward_alloc_add(sk, -(amt << PAGE_SHIFT));
3298 	return ret;
3299 }
3300 EXPORT_SYMBOL(__sk_mem_schedule);
3301 
3302 /**
3303  *	__sk_mem_reduce_allocated - reclaim memory_allocated
3304  *	@sk: socket
3305  *	@amount: number of quanta
3306  *
3307  *	Similar to __sk_mem_reclaim(), but does not update sk_forward_alloc
3308  */
3309 void __sk_mem_reduce_allocated(struct sock *sk, int amount)
3310 {
3311 	sk_memory_allocated_sub(sk, amount);
3312 
3313 	if (mem_cgroup_sockets_enabled && sk->sk_memcg)
3314 		mem_cgroup_uncharge_skmem(sk->sk_memcg, amount);
3315 
3316 	if (sk_under_global_memory_pressure(sk) &&
3317 	    (sk_memory_allocated(sk) < sk_prot_mem_limits(sk, 0)))
3318 		sk_leave_memory_pressure(sk);
3319 }
3320 
3321 /**
3322  *	__sk_mem_reclaim - reclaim sk_forward_alloc and memory_allocated
3323  *	@sk: socket
3324  *	@amount: number of bytes (rounded down to a PAGE_SIZE multiple)
3325  */
3326 void __sk_mem_reclaim(struct sock *sk, int amount)
3327 {
3328 	amount >>= PAGE_SHIFT;
3329 	sk_forward_alloc_add(sk, -(amount << PAGE_SHIFT));
3330 	__sk_mem_reduce_allocated(sk, amount);
3331 }
3332 EXPORT_SYMBOL(__sk_mem_reclaim);
3333 
3334 int sk_set_peek_off(struct sock *sk, int val)
3335 {
3336 	WRITE_ONCE(sk->sk_peek_off, val);
3337 	return 0;
3338 }
3339 EXPORT_SYMBOL_GPL(sk_set_peek_off);
3340 
3341 /*
3342  * Set of default routines for initialising struct proto_ops when
3343  * the protocol does not support a particular function. In certain
3344  * cases where it makes no sense for a protocol to have a "do nothing"
3345  * function, some default processing is provided.
3346  */
3347 
3348 int sock_no_bind(struct socket *sock, struct sockaddr *saddr, int len)
3349 {
3350 	return -EOPNOTSUPP;
3351 }
3352 EXPORT_SYMBOL(sock_no_bind);
3353 
3354 int sock_no_connect(struct socket *sock, struct sockaddr *saddr,
3355 		    int len, int flags)
3356 {
3357 	return -EOPNOTSUPP;
3358 }
3359 EXPORT_SYMBOL(sock_no_connect);
3360 
3361 int sock_no_socketpair(struct socket *sock1, struct socket *sock2)
3362 {
3363 	return -EOPNOTSUPP;
3364 }
3365 EXPORT_SYMBOL(sock_no_socketpair);
3366 
3367 int sock_no_accept(struct socket *sock, struct socket *newsock,
3368 		   struct proto_accept_arg *arg)
3369 {
3370 	return -EOPNOTSUPP;
3371 }
3372 EXPORT_SYMBOL(sock_no_accept);
3373 
3374 int sock_no_getname(struct socket *sock, struct sockaddr *saddr,
3375 		    int peer)
3376 {
3377 	return -EOPNOTSUPP;
3378 }
3379 EXPORT_SYMBOL(sock_no_getname);
3380 
3381 int sock_no_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
3382 {
3383 	return -EOPNOTSUPP;
3384 }
3385 EXPORT_SYMBOL(sock_no_ioctl);
3386 
3387 int sock_no_listen(struct socket *sock, int backlog)
3388 {
3389 	return -EOPNOTSUPP;
3390 }
3391 EXPORT_SYMBOL(sock_no_listen);
3392 
3393 int sock_no_shutdown(struct socket *sock, int how)
3394 {
3395 	return -EOPNOTSUPP;
3396 }
3397 EXPORT_SYMBOL(sock_no_shutdown);
3398 
3399 int sock_no_sendmsg(struct socket *sock, struct msghdr *m, size_t len)
3400 {
3401 	return -EOPNOTSUPP;
3402 }
3403 EXPORT_SYMBOL(sock_no_sendmsg);
3404 
3405 int sock_no_sendmsg_locked(struct sock *sk, struct msghdr *m, size_t len)
3406 {
3407 	return -EOPNOTSUPP;
3408 }
3409 EXPORT_SYMBOL(sock_no_sendmsg_locked);
3410 
3411 int sock_no_recvmsg(struct socket *sock, struct msghdr *m, size_t len,
3412 		    int flags)
3413 {
3414 	return -EOPNOTSUPP;
3415 }
3416 EXPORT_SYMBOL(sock_no_recvmsg);
3417 
3418 int sock_no_mmap(struct file *file, struct socket *sock, struct vm_area_struct *vma)
3419 {
3420 	/* Mirror missing mmap method error code */
3421 	return -ENODEV;
3422 }
3423 EXPORT_SYMBOL(sock_no_mmap);
3424 
3425 /*
3426  * When a file is received (via SCM_RIGHTS, etc), we must bump the
3427  * various sock-based usage counts.
3428  */
3429 void __receive_sock(struct file *file)
3430 {
3431 	struct socket *sock;
3432 
3433 	sock = sock_from_file(file);
3434 	if (sock) {
3435 		sock_update_netprioidx(&sock->sk->sk_cgrp_data);
3436 		sock_update_classid(&sock->sk->sk_cgrp_data);
3437 	}
3438 }
3439 
3440 /*
3441  *	Default Socket Callbacks
3442  */
3443 
3444 static void sock_def_wakeup(struct sock *sk)
3445 {
3446 	struct socket_wq *wq;
3447 
3448 	rcu_read_lock();
3449 	wq = rcu_dereference(sk->sk_wq);
3450 	if (skwq_has_sleeper(wq))
3451 		wake_up_interruptible_all(&wq->wait);
3452 	rcu_read_unlock();
3453 }
3454 
3455 static void sock_def_error_report(struct sock *sk)
3456 {
3457 	struct socket_wq *wq;
3458 
3459 	rcu_read_lock();
3460 	wq = rcu_dereference(sk->sk_wq);
3461 	if (skwq_has_sleeper(wq))
3462 		wake_up_interruptible_poll(&wq->wait, EPOLLERR);
3463 	sk_wake_async_rcu(sk, SOCK_WAKE_IO, POLL_ERR);
3464 	rcu_read_unlock();
3465 }
3466 
3467 void sock_def_readable(struct sock *sk)
3468 {
3469 	struct socket_wq *wq;
3470 
3471 	trace_sk_data_ready(sk);
3472 
3473 	rcu_read_lock();
3474 	wq = rcu_dereference(sk->sk_wq);
3475 	if (skwq_has_sleeper(wq))
3476 		wake_up_interruptible_sync_poll(&wq->wait, EPOLLIN | EPOLLPRI |
3477 						EPOLLRDNORM | EPOLLRDBAND);
3478 	sk_wake_async_rcu(sk, SOCK_WAKE_WAITD, POLL_IN);
3479 	rcu_read_unlock();
3480 }
3481 
3482 static void sock_def_write_space(struct sock *sk)
3483 {
3484 	struct socket_wq *wq;
3485 
3486 	rcu_read_lock();
3487 
3488 	/* Do not wake up a writer until he can make "significant"
3489 	 * progress.  --DaveM
3490 	 */
3491 	if (sock_writeable(sk)) {
3492 		wq = rcu_dereference(sk->sk_wq);
3493 		if (skwq_has_sleeper(wq))
3494 			wake_up_interruptible_sync_poll(&wq->wait, EPOLLOUT |
3495 						EPOLLWRNORM | EPOLLWRBAND);
3496 
3497 		/* Should agree with poll, otherwise some programs break */
3498 		sk_wake_async_rcu(sk, SOCK_WAKE_SPACE, POLL_OUT);
3499 	}
3500 
3501 	rcu_read_unlock();
3502 }
3503 
3504 /* An optimised version of sock_def_write_space(), should only be called
3505  * for SOCK_RCU_FREE sockets under RCU read section and after putting
3506  * ->sk_wmem_alloc.
3507  */
3508 static void sock_def_write_space_wfree(struct sock *sk)
3509 {
3510 	/* Do not wake up a writer until he can make "significant"
3511 	 * progress.  --DaveM
3512 	 */
3513 	if (sock_writeable(sk)) {
3514 		struct socket_wq *wq = rcu_dereference(sk->sk_wq);
3515 
3516 		/* rely on refcount_sub from sock_wfree() */
3517 		smp_mb__after_atomic();
3518 		if (wq && waitqueue_active(&wq->wait))
3519 			wake_up_interruptible_sync_poll(&wq->wait, EPOLLOUT |
3520 						EPOLLWRNORM | EPOLLWRBAND);
3521 
3522 		/* Should agree with poll, otherwise some programs break */
3523 		sk_wake_async_rcu(sk, SOCK_WAKE_SPACE, POLL_OUT);
3524 	}
3525 }
3526 
3527 static void sock_def_destruct(struct sock *sk)
3528 {
3529 }
3530 
3531 void sk_send_sigurg(struct sock *sk)
3532 {
3533 	if (sk->sk_socket && sk->sk_socket->file)
3534 		if (send_sigurg(sk->sk_socket->file))
3535 			sk_wake_async(sk, SOCK_WAKE_URG, POLL_PRI);
3536 }
3537 EXPORT_SYMBOL(sk_send_sigurg);
3538 
3539 void sk_reset_timer(struct sock *sk, struct timer_list* timer,
3540 		    unsigned long expires)
3541 {
3542 	if (!mod_timer(timer, expires))
3543 		sock_hold(sk);
3544 }
3545 EXPORT_SYMBOL(sk_reset_timer);
3546 
3547 void sk_stop_timer(struct sock *sk, struct timer_list* timer)
3548 {
3549 	if (del_timer(timer))
3550 		__sock_put(sk);
3551 }
3552 EXPORT_SYMBOL(sk_stop_timer);
3553 
3554 void sk_stop_timer_sync(struct sock *sk, struct timer_list *timer)
3555 {
3556 	if (del_timer_sync(timer))
3557 		__sock_put(sk);
3558 }
3559 EXPORT_SYMBOL(sk_stop_timer_sync);
3560 
3561 void sock_init_data_uid(struct socket *sock, struct sock *sk, kuid_t uid)
3562 {
3563 	sk_init_common(sk);
3564 	sk->sk_send_head	=	NULL;
3565 
3566 	timer_setup(&sk->sk_timer, NULL, 0);
3567 
3568 	sk->sk_allocation	=	GFP_KERNEL;
3569 	sk->sk_rcvbuf		=	READ_ONCE(sysctl_rmem_default);
3570 	sk->sk_sndbuf		=	READ_ONCE(sysctl_wmem_default);
3571 	sk->sk_state		=	TCP_CLOSE;
3572 	sk->sk_use_task_frag	=	true;
3573 	sk_set_socket(sk, sock);
3574 
3575 	sock_set_flag(sk, SOCK_ZAPPED);
3576 
3577 	if (sock) {
3578 		sk->sk_type	=	sock->type;
3579 		RCU_INIT_POINTER(sk->sk_wq, &sock->wq);
3580 		sock->sk	=	sk;
3581 	} else {
3582 		RCU_INIT_POINTER(sk->sk_wq, NULL);
3583 	}
3584 	sk->sk_uid	=	uid;
3585 
3586 	sk->sk_state_change	=	sock_def_wakeup;
3587 	sk->sk_data_ready	=	sock_def_readable;
3588 	sk->sk_write_space	=	sock_def_write_space;
3589 	sk->sk_error_report	=	sock_def_error_report;
3590 	sk->sk_destruct		=	sock_def_destruct;
3591 
3592 	sk->sk_frag.page	=	NULL;
3593 	sk->sk_frag.offset	=	0;
3594 	sk->sk_peek_off		=	-1;
3595 
3596 	sk->sk_peer_pid 	=	NULL;
3597 	sk->sk_peer_cred	=	NULL;
3598 	spin_lock_init(&sk->sk_peer_lock);
3599 
3600 	sk->sk_write_pending	=	0;
3601 	sk->sk_rcvlowat		=	1;
3602 	sk->sk_rcvtimeo		=	MAX_SCHEDULE_TIMEOUT;
3603 	sk->sk_sndtimeo		=	MAX_SCHEDULE_TIMEOUT;
3604 
3605 	sk->sk_stamp = SK_DEFAULT_STAMP;
3606 #if BITS_PER_LONG==32
3607 	seqlock_init(&sk->sk_stamp_seq);
3608 #endif
3609 	atomic_set(&sk->sk_zckey, 0);
3610 
3611 #ifdef CONFIG_NET_RX_BUSY_POLL
3612 	sk->sk_napi_id		=	0;
3613 	sk->sk_ll_usec		=	READ_ONCE(sysctl_net_busy_read);
3614 #endif
3615 
3616 	sk->sk_max_pacing_rate = ~0UL;
3617 	sk->sk_pacing_rate = ~0UL;
3618 	WRITE_ONCE(sk->sk_pacing_shift, 10);
3619 	sk->sk_incoming_cpu = -1;
3620 
3621 	sk_rx_queue_clear(sk);
3622 	/*
3623 	 * Before updating sk_refcnt, we must commit prior changes to memory
3624 	 * (Documentation/RCU/rculist_nulls.rst for details)
3625 	 */
3626 	smp_wmb();
3627 	refcount_set(&sk->sk_refcnt, 1);
3628 	atomic_set(&sk->sk_drops, 0);
3629 }
3630 EXPORT_SYMBOL(sock_init_data_uid);
3631 
3632 void sock_init_data(struct socket *sock, struct sock *sk)
3633 {
3634 	kuid_t uid = sock ?
3635 		SOCK_INODE(sock)->i_uid :
3636 		make_kuid(sock_net(sk)->user_ns, 0);
3637 
3638 	sock_init_data_uid(sock, sk, uid);
3639 }
3640 EXPORT_SYMBOL(sock_init_data);
3641 
3642 void lock_sock_nested(struct sock *sk, int subclass)
3643 {
3644 	/* The sk_lock has mutex_lock() semantics here. */
3645 	mutex_acquire(&sk->sk_lock.dep_map, subclass, 0, _RET_IP_);
3646 
3647 	might_sleep();
3648 	spin_lock_bh(&sk->sk_lock.slock);
3649 	if (sock_owned_by_user_nocheck(sk))
3650 		__lock_sock(sk);
3651 	sk->sk_lock.owned = 1;
3652 	spin_unlock_bh(&sk->sk_lock.slock);
3653 }
3654 EXPORT_SYMBOL(lock_sock_nested);
3655 
3656 void release_sock(struct sock *sk)
3657 {
3658 	spin_lock_bh(&sk->sk_lock.slock);
3659 	if (sk->sk_backlog.tail)
3660 		__release_sock(sk);
3661 
3662 	if (sk->sk_prot->release_cb)
3663 		INDIRECT_CALL_INET_1(sk->sk_prot->release_cb,
3664 				     tcp_release_cb, sk);
3665 
3666 	sock_release_ownership(sk);
3667 	if (waitqueue_active(&sk->sk_lock.wq))
3668 		wake_up(&sk->sk_lock.wq);
3669 	spin_unlock_bh(&sk->sk_lock.slock);
3670 }
3671 EXPORT_SYMBOL(release_sock);
3672 
3673 bool __lock_sock_fast(struct sock *sk) __acquires(&sk->sk_lock.slock)
3674 {
3675 	might_sleep();
3676 	spin_lock_bh(&sk->sk_lock.slock);
3677 
3678 	if (!sock_owned_by_user_nocheck(sk)) {
3679 		/*
3680 		 * Fast path return with bottom halves disabled and
3681 		 * sock::sk_lock.slock held.
3682 		 *
3683 		 * The 'mutex' is not contended and holding
3684 		 * sock::sk_lock.slock prevents all other lockers to
3685 		 * proceed so the corresponding unlock_sock_fast() can
3686 		 * avoid the slow path of release_sock() completely and
3687 		 * just release slock.
3688 		 *
3689 		 * From a semantical POV this is equivalent to 'acquiring'
3690 		 * the 'mutex', hence the corresponding lockdep
3691 		 * mutex_release() has to happen in the fast path of
3692 		 * unlock_sock_fast().
3693 		 */
3694 		return false;
3695 	}
3696 
3697 	__lock_sock(sk);
3698 	sk->sk_lock.owned = 1;
3699 	__acquire(&sk->sk_lock.slock);
3700 	spin_unlock_bh(&sk->sk_lock.slock);
3701 	return true;
3702 }
3703 EXPORT_SYMBOL(__lock_sock_fast);
3704 
3705 int sock_gettstamp(struct socket *sock, void __user *userstamp,
3706 		   bool timeval, bool time32)
3707 {
3708 	struct sock *sk = sock->sk;
3709 	struct timespec64 ts;
3710 
3711 	sock_enable_timestamp(sk, SOCK_TIMESTAMP);
3712 	ts = ktime_to_timespec64(sock_read_timestamp(sk));
3713 	if (ts.tv_sec == -1)
3714 		return -ENOENT;
3715 	if (ts.tv_sec == 0) {
3716 		ktime_t kt = ktime_get_real();
3717 		sock_write_timestamp(sk, kt);
3718 		ts = ktime_to_timespec64(kt);
3719 	}
3720 
3721 	if (timeval)
3722 		ts.tv_nsec /= 1000;
3723 
3724 #ifdef CONFIG_COMPAT_32BIT_TIME
3725 	if (time32)
3726 		return put_old_timespec32(&ts, userstamp);
3727 #endif
3728 #ifdef CONFIG_SPARC64
3729 	/* beware of padding in sparc64 timeval */
3730 	if (timeval && !in_compat_syscall()) {
3731 		struct __kernel_old_timeval __user tv = {
3732 			.tv_sec = ts.tv_sec,
3733 			.tv_usec = ts.tv_nsec,
3734 		};
3735 		if (copy_to_user(userstamp, &tv, sizeof(tv)))
3736 			return -EFAULT;
3737 		return 0;
3738 	}
3739 #endif
3740 	return put_timespec64(&ts, userstamp);
3741 }
3742 EXPORT_SYMBOL(sock_gettstamp);
3743 
3744 void sock_enable_timestamp(struct sock *sk, enum sock_flags flag)
3745 {
3746 	if (!sock_flag(sk, flag)) {
3747 		unsigned long previous_flags = sk->sk_flags;
3748 
3749 		sock_set_flag(sk, flag);
3750 		/*
3751 		 * we just set one of the two flags which require net
3752 		 * time stamping, but time stamping might have been on
3753 		 * already because of the other one
3754 		 */
3755 		if (sock_needs_netstamp(sk) &&
3756 		    !(previous_flags & SK_FLAGS_TIMESTAMP))
3757 			net_enable_timestamp();
3758 	}
3759 }
3760 
3761 int sock_recv_errqueue(struct sock *sk, struct msghdr *msg, int len,
3762 		       int level, int type)
3763 {
3764 	struct sock_exterr_skb *serr;
3765 	struct sk_buff *skb;
3766 	int copied, err;
3767 
3768 	err = -EAGAIN;
3769 	skb = sock_dequeue_err_skb(sk);
3770 	if (skb == NULL)
3771 		goto out;
3772 
3773 	copied = skb->len;
3774 	if (copied > len) {
3775 		msg->msg_flags |= MSG_TRUNC;
3776 		copied = len;
3777 	}
3778 	err = skb_copy_datagram_msg(skb, 0, msg, copied);
3779 	if (err)
3780 		goto out_free_skb;
3781 
3782 	sock_recv_timestamp(msg, sk, skb);
3783 
3784 	serr = SKB_EXT_ERR(skb);
3785 	put_cmsg(msg, level, type, sizeof(serr->ee), &serr->ee);
3786 
3787 	msg->msg_flags |= MSG_ERRQUEUE;
3788 	err = copied;
3789 
3790 out_free_skb:
3791 	kfree_skb(skb);
3792 out:
3793 	return err;
3794 }
3795 EXPORT_SYMBOL(sock_recv_errqueue);
3796 
3797 /*
3798  *	Get a socket option on an socket.
3799  *
3800  *	FIX: POSIX 1003.1g is very ambiguous here. It states that
3801  *	asynchronous errors should be reported by getsockopt. We assume
3802  *	this means if you specify SO_ERROR (otherwise what is the point of it).
3803  */
3804 int sock_common_getsockopt(struct socket *sock, int level, int optname,
3805 			   char __user *optval, int __user *optlen)
3806 {
3807 	struct sock *sk = sock->sk;
3808 
3809 	/* IPV6_ADDRFORM can change sk->sk_prot under us. */
3810 	return READ_ONCE(sk->sk_prot)->getsockopt(sk, level, optname, optval, optlen);
3811 }
3812 EXPORT_SYMBOL(sock_common_getsockopt);
3813 
3814 int sock_common_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
3815 			int flags)
3816 {
3817 	struct sock *sk = sock->sk;
3818 	int addr_len = 0;
3819 	int err;
3820 
3821 	err = sk->sk_prot->recvmsg(sk, msg, size, flags, &addr_len);
3822 	if (err >= 0)
3823 		msg->msg_namelen = addr_len;
3824 	return err;
3825 }
3826 EXPORT_SYMBOL(sock_common_recvmsg);
3827 
3828 /*
3829  *	Set socket options on an inet socket.
3830  */
3831 int sock_common_setsockopt(struct socket *sock, int level, int optname,
3832 			   sockptr_t optval, unsigned int optlen)
3833 {
3834 	struct sock *sk = sock->sk;
3835 
3836 	/* IPV6_ADDRFORM can change sk->sk_prot under us. */
3837 	return READ_ONCE(sk->sk_prot)->setsockopt(sk, level, optname, optval, optlen);
3838 }
3839 EXPORT_SYMBOL(sock_common_setsockopt);
3840 
3841 void sk_common_release(struct sock *sk)
3842 {
3843 	if (sk->sk_prot->destroy)
3844 		sk->sk_prot->destroy(sk);
3845 
3846 	/*
3847 	 * Observation: when sk_common_release is called, processes have
3848 	 * no access to socket. But net still has.
3849 	 * Step one, detach it from networking:
3850 	 *
3851 	 * A. Remove from hash tables.
3852 	 */
3853 
3854 	sk->sk_prot->unhash(sk);
3855 
3856 	/*
3857 	 * In this point socket cannot receive new packets, but it is possible
3858 	 * that some packets are in flight because some CPU runs receiver and
3859 	 * did hash table lookup before we unhashed socket. They will achieve
3860 	 * receive queue and will be purged by socket destructor.
3861 	 *
3862 	 * Also we still have packets pending on receive queue and probably,
3863 	 * our own packets waiting in device queues. sock_destroy will drain
3864 	 * receive queue, but transmitted packets will delay socket destruction
3865 	 * until the last reference will be released.
3866 	 */
3867 
3868 	sock_orphan(sk);
3869 
3870 	xfrm_sk_free_policy(sk);
3871 
3872 	sock_put(sk);
3873 }
3874 EXPORT_SYMBOL(sk_common_release);
3875 
3876 void sk_get_meminfo(const struct sock *sk, u32 *mem)
3877 {
3878 	memset(mem, 0, sizeof(*mem) * SK_MEMINFO_VARS);
3879 
3880 	mem[SK_MEMINFO_RMEM_ALLOC] = sk_rmem_alloc_get(sk);
3881 	mem[SK_MEMINFO_RCVBUF] = READ_ONCE(sk->sk_rcvbuf);
3882 	mem[SK_MEMINFO_WMEM_ALLOC] = sk_wmem_alloc_get(sk);
3883 	mem[SK_MEMINFO_SNDBUF] = READ_ONCE(sk->sk_sndbuf);
3884 	mem[SK_MEMINFO_FWD_ALLOC] = sk_forward_alloc_get(sk);
3885 	mem[SK_MEMINFO_WMEM_QUEUED] = READ_ONCE(sk->sk_wmem_queued);
3886 	mem[SK_MEMINFO_OPTMEM] = atomic_read(&sk->sk_omem_alloc);
3887 	mem[SK_MEMINFO_BACKLOG] = READ_ONCE(sk->sk_backlog.len);
3888 	mem[SK_MEMINFO_DROPS] = atomic_read(&sk->sk_drops);
3889 }
3890 
3891 #ifdef CONFIG_PROC_FS
3892 static DECLARE_BITMAP(proto_inuse_idx, PROTO_INUSE_NR);
3893 
3894 int sock_prot_inuse_get(struct net *net, struct proto *prot)
3895 {
3896 	int cpu, idx = prot->inuse_idx;
3897 	int res = 0;
3898 
3899 	for_each_possible_cpu(cpu)
3900 		res += per_cpu_ptr(net->core.prot_inuse, cpu)->val[idx];
3901 
3902 	return res >= 0 ? res : 0;
3903 }
3904 EXPORT_SYMBOL_GPL(sock_prot_inuse_get);
3905 
3906 int sock_inuse_get(struct net *net)
3907 {
3908 	int cpu, res = 0;
3909 
3910 	for_each_possible_cpu(cpu)
3911 		res += per_cpu_ptr(net->core.prot_inuse, cpu)->all;
3912 
3913 	return res;
3914 }
3915 
3916 EXPORT_SYMBOL_GPL(sock_inuse_get);
3917 
3918 static int __net_init sock_inuse_init_net(struct net *net)
3919 {
3920 	net->core.prot_inuse = alloc_percpu(struct prot_inuse);
3921 	if (net->core.prot_inuse == NULL)
3922 		return -ENOMEM;
3923 	return 0;
3924 }
3925 
3926 static void __net_exit sock_inuse_exit_net(struct net *net)
3927 {
3928 	free_percpu(net->core.prot_inuse);
3929 }
3930 
3931 static struct pernet_operations net_inuse_ops = {
3932 	.init = sock_inuse_init_net,
3933 	.exit = sock_inuse_exit_net,
3934 };
3935 
3936 static __init int net_inuse_init(void)
3937 {
3938 	if (register_pernet_subsys(&net_inuse_ops))
3939 		panic("Cannot initialize net inuse counters");
3940 
3941 	return 0;
3942 }
3943 
3944 core_initcall(net_inuse_init);
3945 
3946 static int assign_proto_idx(struct proto *prot)
3947 {
3948 	prot->inuse_idx = find_first_zero_bit(proto_inuse_idx, PROTO_INUSE_NR);
3949 
3950 	if (unlikely(prot->inuse_idx == PROTO_INUSE_NR - 1)) {
3951 		pr_err("PROTO_INUSE_NR exhausted\n");
3952 		return -ENOSPC;
3953 	}
3954 
3955 	set_bit(prot->inuse_idx, proto_inuse_idx);
3956 	return 0;
3957 }
3958 
3959 static void release_proto_idx(struct proto *prot)
3960 {
3961 	if (prot->inuse_idx != PROTO_INUSE_NR - 1)
3962 		clear_bit(prot->inuse_idx, proto_inuse_idx);
3963 }
3964 #else
3965 static inline int assign_proto_idx(struct proto *prot)
3966 {
3967 	return 0;
3968 }
3969 
3970 static inline void release_proto_idx(struct proto *prot)
3971 {
3972 }
3973 
3974 #endif
3975 
3976 static void tw_prot_cleanup(struct timewait_sock_ops *twsk_prot)
3977 {
3978 	if (!twsk_prot)
3979 		return;
3980 	kfree(twsk_prot->twsk_slab_name);
3981 	twsk_prot->twsk_slab_name = NULL;
3982 	kmem_cache_destroy(twsk_prot->twsk_slab);
3983 	twsk_prot->twsk_slab = NULL;
3984 }
3985 
3986 static int tw_prot_init(const struct proto *prot)
3987 {
3988 	struct timewait_sock_ops *twsk_prot = prot->twsk_prot;
3989 
3990 	if (!twsk_prot)
3991 		return 0;
3992 
3993 	twsk_prot->twsk_slab_name = kasprintf(GFP_KERNEL, "tw_sock_%s",
3994 					      prot->name);
3995 	if (!twsk_prot->twsk_slab_name)
3996 		return -ENOMEM;
3997 
3998 	twsk_prot->twsk_slab =
3999 		kmem_cache_create(twsk_prot->twsk_slab_name,
4000 				  twsk_prot->twsk_obj_size, 0,
4001 				  SLAB_ACCOUNT | prot->slab_flags,
4002 				  NULL);
4003 	if (!twsk_prot->twsk_slab) {
4004 		pr_crit("%s: Can't create timewait sock SLAB cache!\n",
4005 			prot->name);
4006 		return -ENOMEM;
4007 	}
4008 
4009 	return 0;
4010 }
4011 
4012 static void req_prot_cleanup(struct request_sock_ops *rsk_prot)
4013 {
4014 	if (!rsk_prot)
4015 		return;
4016 	kfree(rsk_prot->slab_name);
4017 	rsk_prot->slab_name = NULL;
4018 	kmem_cache_destroy(rsk_prot->slab);
4019 	rsk_prot->slab = NULL;
4020 }
4021 
4022 static int req_prot_init(const struct proto *prot)
4023 {
4024 	struct request_sock_ops *rsk_prot = prot->rsk_prot;
4025 
4026 	if (!rsk_prot)
4027 		return 0;
4028 
4029 	rsk_prot->slab_name = kasprintf(GFP_KERNEL, "request_sock_%s",
4030 					prot->name);
4031 	if (!rsk_prot->slab_name)
4032 		return -ENOMEM;
4033 
4034 	rsk_prot->slab = kmem_cache_create(rsk_prot->slab_name,
4035 					   rsk_prot->obj_size, 0,
4036 					   SLAB_ACCOUNT | prot->slab_flags,
4037 					   NULL);
4038 
4039 	if (!rsk_prot->slab) {
4040 		pr_crit("%s: Can't create request sock SLAB cache!\n",
4041 			prot->name);
4042 		return -ENOMEM;
4043 	}
4044 	return 0;
4045 }
4046 
4047 int proto_register(struct proto *prot, int alloc_slab)
4048 {
4049 	int ret = -ENOBUFS;
4050 
4051 	if (prot->memory_allocated && !prot->sysctl_mem) {
4052 		pr_err("%s: missing sysctl_mem\n", prot->name);
4053 		return -EINVAL;
4054 	}
4055 	if (prot->memory_allocated && !prot->per_cpu_fw_alloc) {
4056 		pr_err("%s: missing per_cpu_fw_alloc\n", prot->name);
4057 		return -EINVAL;
4058 	}
4059 	if (alloc_slab) {
4060 		prot->slab = kmem_cache_create_usercopy(prot->name,
4061 					prot->obj_size, 0,
4062 					SLAB_HWCACHE_ALIGN | SLAB_ACCOUNT |
4063 					prot->slab_flags,
4064 					prot->useroffset, prot->usersize,
4065 					NULL);
4066 
4067 		if (prot->slab == NULL) {
4068 			pr_crit("%s: Can't create sock SLAB cache!\n",
4069 				prot->name);
4070 			goto out;
4071 		}
4072 
4073 		if (req_prot_init(prot))
4074 			goto out_free_request_sock_slab;
4075 
4076 		if (tw_prot_init(prot))
4077 			goto out_free_timewait_sock_slab;
4078 	}
4079 
4080 	mutex_lock(&proto_list_mutex);
4081 	ret = assign_proto_idx(prot);
4082 	if (ret) {
4083 		mutex_unlock(&proto_list_mutex);
4084 		goto out_free_timewait_sock_slab;
4085 	}
4086 	list_add(&prot->node, &proto_list);
4087 	mutex_unlock(&proto_list_mutex);
4088 	return ret;
4089 
4090 out_free_timewait_sock_slab:
4091 	if (alloc_slab)
4092 		tw_prot_cleanup(prot->twsk_prot);
4093 out_free_request_sock_slab:
4094 	if (alloc_slab) {
4095 		req_prot_cleanup(prot->rsk_prot);
4096 
4097 		kmem_cache_destroy(prot->slab);
4098 		prot->slab = NULL;
4099 	}
4100 out:
4101 	return ret;
4102 }
4103 EXPORT_SYMBOL(proto_register);
4104 
4105 void proto_unregister(struct proto *prot)
4106 {
4107 	mutex_lock(&proto_list_mutex);
4108 	release_proto_idx(prot);
4109 	list_del(&prot->node);
4110 	mutex_unlock(&proto_list_mutex);
4111 
4112 	kmem_cache_destroy(prot->slab);
4113 	prot->slab = NULL;
4114 
4115 	req_prot_cleanup(prot->rsk_prot);
4116 	tw_prot_cleanup(prot->twsk_prot);
4117 }
4118 EXPORT_SYMBOL(proto_unregister);
4119 
4120 int sock_load_diag_module(int family, int protocol)
4121 {
4122 	if (!protocol) {
4123 		if (!sock_is_registered(family))
4124 			return -ENOENT;
4125 
4126 		return request_module("net-pf-%d-proto-%d-type-%d", PF_NETLINK,
4127 				      NETLINK_SOCK_DIAG, family);
4128 	}
4129 
4130 #ifdef CONFIG_INET
4131 	if (family == AF_INET &&
4132 	    protocol != IPPROTO_RAW &&
4133 	    protocol < MAX_INET_PROTOS &&
4134 	    !rcu_access_pointer(inet_protos[protocol]))
4135 		return -ENOENT;
4136 #endif
4137 
4138 	return request_module("net-pf-%d-proto-%d-type-%d-%d", PF_NETLINK,
4139 			      NETLINK_SOCK_DIAG, family, protocol);
4140 }
4141 EXPORT_SYMBOL(sock_load_diag_module);
4142 
4143 #ifdef CONFIG_PROC_FS
4144 static void *proto_seq_start(struct seq_file *seq, loff_t *pos)
4145 	__acquires(proto_list_mutex)
4146 {
4147 	mutex_lock(&proto_list_mutex);
4148 	return seq_list_start_head(&proto_list, *pos);
4149 }
4150 
4151 static void *proto_seq_next(struct seq_file *seq, void *v, loff_t *pos)
4152 {
4153 	return seq_list_next(v, &proto_list, pos);
4154 }
4155 
4156 static void proto_seq_stop(struct seq_file *seq, void *v)
4157 	__releases(proto_list_mutex)
4158 {
4159 	mutex_unlock(&proto_list_mutex);
4160 }
4161 
4162 static char proto_method_implemented(const void *method)
4163 {
4164 	return method == NULL ? 'n' : 'y';
4165 }
4166 static long sock_prot_memory_allocated(struct proto *proto)
4167 {
4168 	return proto->memory_allocated != NULL ? proto_memory_allocated(proto) : -1L;
4169 }
4170 
4171 static const char *sock_prot_memory_pressure(struct proto *proto)
4172 {
4173 	return proto->memory_pressure != NULL ?
4174 	proto_memory_pressure(proto) ? "yes" : "no" : "NI";
4175 }
4176 
4177 static void proto_seq_printf(struct seq_file *seq, struct proto *proto)
4178 {
4179 
4180 	seq_printf(seq, "%-9s %4u %6d  %6ld   %-3s %6u   %-3s  %-10s "
4181 			"%2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c\n",
4182 		   proto->name,
4183 		   proto->obj_size,
4184 		   sock_prot_inuse_get(seq_file_net(seq), proto),
4185 		   sock_prot_memory_allocated(proto),
4186 		   sock_prot_memory_pressure(proto),
4187 		   proto->max_header,
4188 		   proto->slab == NULL ? "no" : "yes",
4189 		   module_name(proto->owner),
4190 		   proto_method_implemented(proto->close),
4191 		   proto_method_implemented(proto->connect),
4192 		   proto_method_implemented(proto->disconnect),
4193 		   proto_method_implemented(proto->accept),
4194 		   proto_method_implemented(proto->ioctl),
4195 		   proto_method_implemented(proto->init),
4196 		   proto_method_implemented(proto->destroy),
4197 		   proto_method_implemented(proto->shutdown),
4198 		   proto_method_implemented(proto->setsockopt),
4199 		   proto_method_implemented(proto->getsockopt),
4200 		   proto_method_implemented(proto->sendmsg),
4201 		   proto_method_implemented(proto->recvmsg),
4202 		   proto_method_implemented(proto->bind),
4203 		   proto_method_implemented(proto->backlog_rcv),
4204 		   proto_method_implemented(proto->hash),
4205 		   proto_method_implemented(proto->unhash),
4206 		   proto_method_implemented(proto->get_port),
4207 		   proto_method_implemented(proto->enter_memory_pressure));
4208 }
4209 
4210 static int proto_seq_show(struct seq_file *seq, void *v)
4211 {
4212 	if (v == &proto_list)
4213 		seq_printf(seq, "%-9s %-4s %-8s %-6s %-5s %-7s %-4s %-10s %s",
4214 			   "protocol",
4215 			   "size",
4216 			   "sockets",
4217 			   "memory",
4218 			   "press",
4219 			   "maxhdr",
4220 			   "slab",
4221 			   "module",
4222 			   "cl co di ac io in de sh ss gs se re bi br ha uh gp em\n");
4223 	else
4224 		proto_seq_printf(seq, list_entry(v, struct proto, node));
4225 	return 0;
4226 }
4227 
4228 static const struct seq_operations proto_seq_ops = {
4229 	.start  = proto_seq_start,
4230 	.next   = proto_seq_next,
4231 	.stop   = proto_seq_stop,
4232 	.show   = proto_seq_show,
4233 };
4234 
4235 static __net_init int proto_init_net(struct net *net)
4236 {
4237 	if (!proc_create_net("protocols", 0444, net->proc_net, &proto_seq_ops,
4238 			sizeof(struct seq_net_private)))
4239 		return -ENOMEM;
4240 
4241 	return 0;
4242 }
4243 
4244 static __net_exit void proto_exit_net(struct net *net)
4245 {
4246 	remove_proc_entry("protocols", net->proc_net);
4247 }
4248 
4249 
4250 static __net_initdata struct pernet_operations proto_net_ops = {
4251 	.init = proto_init_net,
4252 	.exit = proto_exit_net,
4253 };
4254 
4255 static int __init proto_init(void)
4256 {
4257 	return register_pernet_subsys(&proto_net_ops);
4258 }
4259 
4260 subsys_initcall(proto_init);
4261 
4262 #endif /* PROC_FS */
4263 
4264 #ifdef CONFIG_NET_RX_BUSY_POLL
4265 bool sk_busy_loop_end(void *p, unsigned long start_time)
4266 {
4267 	struct sock *sk = p;
4268 
4269 	if (!skb_queue_empty_lockless(&sk->sk_receive_queue))
4270 		return true;
4271 
4272 	if (sk_is_udp(sk) &&
4273 	    !skb_queue_empty_lockless(&udp_sk(sk)->reader_queue))
4274 		return true;
4275 
4276 	return sk_busy_loop_timeout(sk, start_time);
4277 }
4278 EXPORT_SYMBOL(sk_busy_loop_end);
4279 #endif /* CONFIG_NET_RX_BUSY_POLL */
4280 
4281 int sock_bind_add(struct sock *sk, struct sockaddr *addr, int addr_len)
4282 {
4283 	if (!sk->sk_prot->bind_add)
4284 		return -EOPNOTSUPP;
4285 	return sk->sk_prot->bind_add(sk, addr, addr_len);
4286 }
4287 EXPORT_SYMBOL(sock_bind_add);
4288 
4289 /* Copy 'size' bytes from userspace and return `size` back to userspace */
4290 int sock_ioctl_inout(struct sock *sk, unsigned int cmd,
4291 		     void __user *arg, void *karg, size_t size)
4292 {
4293 	int ret;
4294 
4295 	if (copy_from_user(karg, arg, size))
4296 		return -EFAULT;
4297 
4298 	ret = READ_ONCE(sk->sk_prot)->ioctl(sk, cmd, karg);
4299 	if (ret)
4300 		return ret;
4301 
4302 	if (copy_to_user(arg, karg, size))
4303 		return -EFAULT;
4304 
4305 	return 0;
4306 }
4307 EXPORT_SYMBOL(sock_ioctl_inout);
4308 
4309 /* This is the most common ioctl prep function, where the result (4 bytes) is
4310  * copied back to userspace if the ioctl() returns successfully. No input is
4311  * copied from userspace as input argument.
4312  */
4313 static int sock_ioctl_out(struct sock *sk, unsigned int cmd, void __user *arg)
4314 {
4315 	int ret, karg = 0;
4316 
4317 	ret = READ_ONCE(sk->sk_prot)->ioctl(sk, cmd, &karg);
4318 	if (ret)
4319 		return ret;
4320 
4321 	return put_user(karg, (int __user *)arg);
4322 }
4323 
4324 /* A wrapper around sock ioctls, which copies the data from userspace
4325  * (depending on the protocol/ioctl), and copies back the result to userspace.
4326  * The main motivation for this function is to pass kernel memory to the
4327  * protocol ioctl callbacks, instead of userspace memory.
4328  */
4329 int sk_ioctl(struct sock *sk, unsigned int cmd, void __user *arg)
4330 {
4331 	int rc = 1;
4332 
4333 	if (sk->sk_type == SOCK_RAW && sk->sk_family == AF_INET)
4334 		rc = ipmr_sk_ioctl(sk, cmd, arg);
4335 	else if (sk->sk_type == SOCK_RAW && sk->sk_family == AF_INET6)
4336 		rc = ip6mr_sk_ioctl(sk, cmd, arg);
4337 	else if (sk_is_phonet(sk))
4338 		rc = phonet_sk_ioctl(sk, cmd, arg);
4339 
4340 	/* If ioctl was processed, returns its value */
4341 	if (rc <= 0)
4342 		return rc;
4343 
4344 	/* Otherwise call the default handler */
4345 	return sock_ioctl_out(sk, cmd, arg);
4346 }
4347 EXPORT_SYMBOL(sk_ioctl);
4348 
4349 static int __init sock_struct_check(void)
4350 {
4351 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_rx, sk_drops);
4352 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_rx, sk_peek_off);
4353 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_rx, sk_error_queue);
4354 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_rx, sk_receive_queue);
4355 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_rx, sk_backlog);
4356 
4357 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_rx, sk_rx_dst);
4358 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_rx, sk_rx_dst_ifindex);
4359 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_rx, sk_rx_dst_cookie);
4360 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_rx, sk_rcvbuf);
4361 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_rx, sk_filter);
4362 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_rx, sk_wq);
4363 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_rx, sk_data_ready);
4364 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_rx, sk_rcvtimeo);
4365 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_rx, sk_rcvlowat);
4366 
4367 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_rxtx, sk_err);
4368 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_rxtx, sk_socket);
4369 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_rxtx, sk_memcg);
4370 
4371 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_rxtx, sk_lock);
4372 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_rxtx, sk_reserved_mem);
4373 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_rxtx, sk_forward_alloc);
4374 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_rxtx, sk_tsflags);
4375 
4376 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_omem_alloc);
4377 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_omem_alloc);
4378 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_sndbuf);
4379 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_wmem_queued);
4380 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_wmem_alloc);
4381 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_tsq_flags);
4382 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_send_head);
4383 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_write_queue);
4384 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_write_pending);
4385 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_dst_pending_confirm);
4386 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_pacing_status);
4387 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_frag);
4388 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_timer);
4389 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_pacing_rate);
4390 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_zckey);
4391 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_tskey);
4392 
4393 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_max_pacing_rate);
4394 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_sndtimeo);
4395 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_priority);
4396 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_mark);
4397 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_dst_cache);
4398 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_route_caps);
4399 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_gso_type);
4400 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_gso_max_size);
4401 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_allocation);
4402 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_txhash);
4403 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_gso_max_segs);
4404 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_pacing_shift);
4405 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_use_task_frag);
4406 	return 0;
4407 }
4408 
4409 core_initcall(sock_struct_check);
4410