xref: /linux/net/core/sock.c (revision 07fdad3a93756b872da7b53647715c48d0f4a2d0)
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 <uapi/linux/pidfd.h>
152 
153 #include "dev.h"
154 
155 static DEFINE_MUTEX(proto_list_mutex);
156 static LIST_HEAD(proto_list);
157 
158 static void sock_def_write_space_wfree(struct sock *sk);
159 static void sock_def_write_space(struct sock *sk);
160 
161 /**
162  * sk_ns_capable - General socket capability test
163  * @sk: Socket to use a capability on or through
164  * @user_ns: The user namespace of the capability to use
165  * @cap: The capability to use
166  *
167  * Test to see if the opener of the socket had when the socket was
168  * created and the current process has the capability @cap in the user
169  * namespace @user_ns.
170  */
171 bool sk_ns_capable(const struct sock *sk,
172 		   struct user_namespace *user_ns, int cap)
173 {
174 	return file_ns_capable(sk->sk_socket->file, user_ns, cap) &&
175 		ns_capable(user_ns, cap);
176 }
177 EXPORT_SYMBOL(sk_ns_capable);
178 
179 /**
180  * sk_capable - Socket global capability test
181  * @sk: Socket to use a capability on or through
182  * @cap: The global capability to use
183  *
184  * Test to see if the opener of the socket had when the socket was
185  * created and the current process has the capability @cap in all user
186  * namespaces.
187  */
188 bool sk_capable(const struct sock *sk, int cap)
189 {
190 	return sk_ns_capable(sk, &init_user_ns, cap);
191 }
192 EXPORT_SYMBOL(sk_capable);
193 
194 /**
195  * sk_net_capable - Network namespace socket capability test
196  * @sk: Socket to use a capability on or through
197  * @cap: The capability to use
198  *
199  * Test to see if the opener of the socket had when the socket was created
200  * and the current process has the capability @cap over the network namespace
201  * the socket is a member of.
202  */
203 bool sk_net_capable(const struct sock *sk, int cap)
204 {
205 	return sk_ns_capable(sk, sock_net(sk)->user_ns, cap);
206 }
207 EXPORT_SYMBOL(sk_net_capable);
208 
209 /*
210  * Each address family might have different locking rules, so we have
211  * one slock key per address family and separate keys for internal and
212  * userspace sockets.
213  */
214 static struct lock_class_key af_family_keys[AF_MAX];
215 static struct lock_class_key af_family_kern_keys[AF_MAX];
216 static struct lock_class_key af_family_slock_keys[AF_MAX];
217 static struct lock_class_key af_family_kern_slock_keys[AF_MAX];
218 
219 /*
220  * Make lock validator output more readable. (we pre-construct these
221  * strings build-time, so that runtime initialization of socket
222  * locks is fast):
223  */
224 
225 #define _sock_locks(x)						  \
226   x "AF_UNSPEC",	x "AF_UNIX"     ,	x "AF_INET"     , \
227   x "AF_AX25"  ,	x "AF_IPX"      ,	x "AF_APPLETALK", \
228   x "AF_NETROM",	x "AF_BRIDGE"   ,	x "AF_ATMPVC"   , \
229   x "AF_X25"   ,	x "AF_INET6"    ,	x "AF_ROSE"     , \
230   x "AF_DECnet",	x "AF_NETBEUI"  ,	x "AF_SECURITY" , \
231   x "AF_KEY"   ,	x "AF_NETLINK"  ,	x "AF_PACKET"   , \
232   x "AF_ASH"   ,	x "AF_ECONET"   ,	x "AF_ATMSVC"   , \
233   x "AF_RDS"   ,	x "AF_SNA"      ,	x "AF_IRDA"     , \
234   x "AF_PPPOX" ,	x "AF_WANPIPE"  ,	x "AF_LLC"      , \
235   x "27"       ,	x "28"          ,	x "AF_CAN"      , \
236   x "AF_TIPC"  ,	x "AF_BLUETOOTH",	x "IUCV"        , \
237   x "AF_RXRPC" ,	x "AF_ISDN"     ,	x "AF_PHONET"   , \
238   x "AF_IEEE802154",	x "AF_CAIF"	,	x "AF_ALG"      , \
239   x "AF_NFC"   ,	x "AF_VSOCK"    ,	x "AF_KCM"      , \
240   x "AF_QIPCRTR",	x "AF_SMC"	,	x "AF_XDP"	, \
241   x "AF_MCTP"  , \
242   x "AF_MAX"
243 
244 static const char *const af_family_key_strings[AF_MAX+1] = {
245 	_sock_locks("sk_lock-")
246 };
247 static const char *const af_family_slock_key_strings[AF_MAX+1] = {
248 	_sock_locks("slock-")
249 };
250 static const char *const af_family_clock_key_strings[AF_MAX+1] = {
251 	_sock_locks("clock-")
252 };
253 
254 static const char *const af_family_kern_key_strings[AF_MAX+1] = {
255 	_sock_locks("k-sk_lock-")
256 };
257 static const char *const af_family_kern_slock_key_strings[AF_MAX+1] = {
258 	_sock_locks("k-slock-")
259 };
260 static const char *const af_family_kern_clock_key_strings[AF_MAX+1] = {
261 	_sock_locks("k-clock-")
262 };
263 static const char *const af_family_rlock_key_strings[AF_MAX+1] = {
264 	_sock_locks("rlock-")
265 };
266 static const char *const af_family_wlock_key_strings[AF_MAX+1] = {
267 	_sock_locks("wlock-")
268 };
269 static const char *const af_family_elock_key_strings[AF_MAX+1] = {
270 	_sock_locks("elock-")
271 };
272 
273 /*
274  * sk_callback_lock and sk queues locking rules are per-address-family,
275  * so split the lock classes by using a per-AF key:
276  */
277 static struct lock_class_key af_callback_keys[AF_MAX];
278 static struct lock_class_key af_rlock_keys[AF_MAX];
279 static struct lock_class_key af_wlock_keys[AF_MAX];
280 static struct lock_class_key af_elock_keys[AF_MAX];
281 static struct lock_class_key af_kern_callback_keys[AF_MAX];
282 
283 /* Run time adjustable parameters. */
284 __u32 sysctl_wmem_max __read_mostly = 4 << 20;
285 EXPORT_SYMBOL(sysctl_wmem_max);
286 __u32 sysctl_rmem_max __read_mostly = 4 << 20;
287 EXPORT_SYMBOL(sysctl_rmem_max);
288 __u32 sysctl_wmem_default __read_mostly = SK_WMEM_DEFAULT;
289 __u32 sysctl_rmem_default __read_mostly = SK_RMEM_DEFAULT;
290 
291 DEFINE_STATIC_KEY_FALSE(memalloc_socks_key);
292 EXPORT_SYMBOL_GPL(memalloc_socks_key);
293 
294 /**
295  * sk_set_memalloc - sets %SOCK_MEMALLOC
296  * @sk: socket to set it on
297  *
298  * Set %SOCK_MEMALLOC on a socket for access to emergency reserves.
299  * It's the responsibility of the admin to adjust min_free_kbytes
300  * to meet the requirements
301  */
302 void sk_set_memalloc(struct sock *sk)
303 {
304 	sock_set_flag(sk, SOCK_MEMALLOC);
305 	sk->sk_allocation |= __GFP_MEMALLOC;
306 	static_branch_inc(&memalloc_socks_key);
307 }
308 EXPORT_SYMBOL_GPL(sk_set_memalloc);
309 
310 void sk_clear_memalloc(struct sock *sk)
311 {
312 	sock_reset_flag(sk, SOCK_MEMALLOC);
313 	sk->sk_allocation &= ~__GFP_MEMALLOC;
314 	static_branch_dec(&memalloc_socks_key);
315 
316 	/*
317 	 * SOCK_MEMALLOC is allowed to ignore rmem limits to ensure forward
318 	 * progress of swapping. SOCK_MEMALLOC may be cleared while
319 	 * it has rmem allocations due to the last swapfile being deactivated
320 	 * but there is a risk that the socket is unusable due to exceeding
321 	 * the rmem limits. Reclaim the reserves and obey rmem limits again.
322 	 */
323 	sk_mem_reclaim(sk);
324 }
325 EXPORT_SYMBOL_GPL(sk_clear_memalloc);
326 
327 int __sk_backlog_rcv(struct sock *sk, struct sk_buff *skb)
328 {
329 	int ret;
330 	unsigned int noreclaim_flag;
331 
332 	/* these should have been dropped before queueing */
333 	BUG_ON(!sock_flag(sk, SOCK_MEMALLOC));
334 
335 	noreclaim_flag = memalloc_noreclaim_save();
336 	ret = INDIRECT_CALL_INET(sk->sk_backlog_rcv,
337 				 tcp_v6_do_rcv,
338 				 tcp_v4_do_rcv,
339 				 sk, skb);
340 	memalloc_noreclaim_restore(noreclaim_flag);
341 
342 	return ret;
343 }
344 EXPORT_SYMBOL(__sk_backlog_rcv);
345 
346 void sk_error_report(struct sock *sk)
347 {
348 	sk->sk_error_report(sk);
349 
350 	switch (sk->sk_family) {
351 	case AF_INET:
352 		fallthrough;
353 	case AF_INET6:
354 		trace_inet_sk_error_report(sk);
355 		break;
356 	default:
357 		break;
358 	}
359 }
360 EXPORT_SYMBOL(sk_error_report);
361 
362 int sock_get_timeout(long timeo, void *optval, bool old_timeval)
363 {
364 	struct __kernel_sock_timeval tv;
365 
366 	if (timeo == MAX_SCHEDULE_TIMEOUT) {
367 		tv.tv_sec = 0;
368 		tv.tv_usec = 0;
369 	} else {
370 		tv.tv_sec = timeo / HZ;
371 		tv.tv_usec = ((timeo % HZ) * USEC_PER_SEC) / HZ;
372 	}
373 
374 	if (old_timeval && in_compat_syscall() && !COMPAT_USE_64BIT_TIME) {
375 		struct old_timeval32 tv32 = { tv.tv_sec, tv.tv_usec };
376 		*(struct old_timeval32 *)optval = tv32;
377 		return sizeof(tv32);
378 	}
379 
380 	if (old_timeval) {
381 		struct __kernel_old_timeval old_tv;
382 		old_tv.tv_sec = tv.tv_sec;
383 		old_tv.tv_usec = tv.tv_usec;
384 		*(struct __kernel_old_timeval *)optval = old_tv;
385 		return sizeof(old_tv);
386 	}
387 
388 	*(struct __kernel_sock_timeval *)optval = tv;
389 	return sizeof(tv);
390 }
391 EXPORT_SYMBOL(sock_get_timeout);
392 
393 int sock_copy_user_timeval(struct __kernel_sock_timeval *tv,
394 			   sockptr_t optval, int optlen, bool old_timeval)
395 {
396 	if (old_timeval && in_compat_syscall() && !COMPAT_USE_64BIT_TIME) {
397 		struct old_timeval32 tv32;
398 
399 		if (optlen < sizeof(tv32))
400 			return -EINVAL;
401 
402 		if (copy_from_sockptr(&tv32, optval, sizeof(tv32)))
403 			return -EFAULT;
404 		tv->tv_sec = tv32.tv_sec;
405 		tv->tv_usec = tv32.tv_usec;
406 	} else if (old_timeval) {
407 		struct __kernel_old_timeval old_tv;
408 
409 		if (optlen < sizeof(old_tv))
410 			return -EINVAL;
411 		if (copy_from_sockptr(&old_tv, optval, sizeof(old_tv)))
412 			return -EFAULT;
413 		tv->tv_sec = old_tv.tv_sec;
414 		tv->tv_usec = old_tv.tv_usec;
415 	} else {
416 		if (optlen < sizeof(*tv))
417 			return -EINVAL;
418 		if (copy_from_sockptr(tv, optval, sizeof(*tv)))
419 			return -EFAULT;
420 	}
421 
422 	return 0;
423 }
424 EXPORT_SYMBOL(sock_copy_user_timeval);
425 
426 static int sock_set_timeout(long *timeo_p, sockptr_t optval, int optlen,
427 			    bool old_timeval)
428 {
429 	struct __kernel_sock_timeval tv;
430 	int err = sock_copy_user_timeval(&tv, optval, optlen, old_timeval);
431 	long val;
432 
433 	if (err)
434 		return err;
435 
436 	if (tv.tv_usec < 0 || tv.tv_usec >= USEC_PER_SEC)
437 		return -EDOM;
438 
439 	if (tv.tv_sec < 0) {
440 		static int warned __read_mostly;
441 
442 		WRITE_ONCE(*timeo_p, 0);
443 		if (warned < 10 && net_ratelimit()) {
444 			warned++;
445 			pr_info("%s: `%s' (pid %d) tries to set negative timeout\n",
446 				__func__, current->comm, task_pid_nr(current));
447 		}
448 		return 0;
449 	}
450 	val = MAX_SCHEDULE_TIMEOUT;
451 	if ((tv.tv_sec || tv.tv_usec) &&
452 	    (tv.tv_sec < (MAX_SCHEDULE_TIMEOUT / HZ - 1)))
453 		val = tv.tv_sec * HZ + DIV_ROUND_UP((unsigned long)tv.tv_usec,
454 						    USEC_PER_SEC / HZ);
455 	WRITE_ONCE(*timeo_p, val);
456 	return 0;
457 }
458 
459 static bool sk_set_prio_allowed(const struct sock *sk, int val)
460 {
461 	return ((val >= TC_PRIO_BESTEFFORT && val <= TC_PRIO_INTERACTIVE) ||
462 		sockopt_ns_capable(sock_net(sk)->user_ns, CAP_NET_RAW) ||
463 		sockopt_ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN));
464 }
465 
466 static bool sock_needs_netstamp(const struct sock *sk)
467 {
468 	switch (sk->sk_family) {
469 	case AF_UNSPEC:
470 	case AF_UNIX:
471 		return false;
472 	default:
473 		return true;
474 	}
475 }
476 
477 static void sock_disable_timestamp(struct sock *sk, unsigned long flags)
478 {
479 	if (sk->sk_flags & flags) {
480 		sk->sk_flags &= ~flags;
481 		if (sock_needs_netstamp(sk) &&
482 		    !(sk->sk_flags & SK_FLAGS_TIMESTAMP))
483 			net_disable_timestamp();
484 	}
485 }
486 
487 
488 int __sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
489 {
490 	unsigned long flags;
491 	struct sk_buff_head *list = &sk->sk_receive_queue;
492 
493 	if (atomic_read(&sk->sk_rmem_alloc) >= READ_ONCE(sk->sk_rcvbuf)) {
494 		sk_drops_inc(sk);
495 		trace_sock_rcvqueue_full(sk, skb);
496 		return -ENOMEM;
497 	}
498 
499 	if (!sk_rmem_schedule(sk, skb, skb->truesize)) {
500 		sk_drops_inc(sk);
501 		return -ENOBUFS;
502 	}
503 
504 	skb->dev = NULL;
505 	skb_set_owner_r(skb, sk);
506 
507 	/* we escape from rcu protected region, make sure we dont leak
508 	 * a norefcounted dst
509 	 */
510 	skb_dst_force(skb);
511 
512 	spin_lock_irqsave(&list->lock, flags);
513 	sock_skb_set_dropcount(sk, skb);
514 	__skb_queue_tail(list, skb);
515 	spin_unlock_irqrestore(&list->lock, flags);
516 
517 	if (!sock_flag(sk, SOCK_DEAD))
518 		sk->sk_data_ready(sk);
519 	return 0;
520 }
521 EXPORT_SYMBOL(__sock_queue_rcv_skb);
522 
523 int sock_queue_rcv_skb_reason(struct sock *sk, struct sk_buff *skb,
524 			      enum skb_drop_reason *reason)
525 {
526 	enum skb_drop_reason drop_reason;
527 	int err;
528 
529 	err = sk_filter_reason(sk, skb, &drop_reason);
530 	if (err)
531 		goto out;
532 
533 	err = __sock_queue_rcv_skb(sk, skb);
534 	switch (err) {
535 	case -ENOMEM:
536 		drop_reason = SKB_DROP_REASON_SOCKET_RCVBUFF;
537 		break;
538 	case -ENOBUFS:
539 		drop_reason = SKB_DROP_REASON_PROTO_MEM;
540 		break;
541 	default:
542 		drop_reason = SKB_NOT_DROPPED_YET;
543 		break;
544 	}
545 out:
546 	if (reason)
547 		*reason = drop_reason;
548 	return err;
549 }
550 EXPORT_SYMBOL(sock_queue_rcv_skb_reason);
551 
552 int __sk_receive_skb(struct sock *sk, struct sk_buff *skb,
553 		     const int nested, unsigned int trim_cap, bool refcounted)
554 {
555 	enum skb_drop_reason reason = SKB_DROP_REASON_NOT_SPECIFIED;
556 	int rc = NET_RX_SUCCESS;
557 	int err;
558 
559 	if (sk_filter_trim_cap(sk, skb, trim_cap, &reason))
560 		goto discard_and_relse;
561 
562 	skb->dev = NULL;
563 
564 	if (sk_rcvqueues_full(sk, READ_ONCE(sk->sk_rcvbuf))) {
565 		sk_drops_inc(sk);
566 		reason = SKB_DROP_REASON_SOCKET_RCVBUFF;
567 		goto discard_and_relse;
568 	}
569 	if (nested)
570 		bh_lock_sock_nested(sk);
571 	else
572 		bh_lock_sock(sk);
573 	if (!sock_owned_by_user(sk)) {
574 		/*
575 		 * trylock + unlock semantics:
576 		 */
577 		mutex_acquire(&sk->sk_lock.dep_map, 0, 1, _RET_IP_);
578 
579 		rc = sk_backlog_rcv(sk, skb);
580 
581 		mutex_release(&sk->sk_lock.dep_map, _RET_IP_);
582 	} else if ((err = sk_add_backlog(sk, skb, READ_ONCE(sk->sk_rcvbuf)))) {
583 		bh_unlock_sock(sk);
584 		if (err == -ENOMEM)
585 			reason = SKB_DROP_REASON_PFMEMALLOC;
586 		if (err == -ENOBUFS)
587 			reason = SKB_DROP_REASON_SOCKET_BACKLOG;
588 		sk_drops_inc(sk);
589 		goto discard_and_relse;
590 	}
591 
592 	bh_unlock_sock(sk);
593 out:
594 	if (refcounted)
595 		sock_put(sk);
596 	return rc;
597 discard_and_relse:
598 	sk_skb_reason_drop(sk, skb, reason);
599 	goto out;
600 }
601 EXPORT_SYMBOL(__sk_receive_skb);
602 
603 INDIRECT_CALLABLE_DECLARE(struct dst_entry *ip6_dst_check(struct dst_entry *,
604 							  u32));
605 INDIRECT_CALLABLE_DECLARE(struct dst_entry *ipv4_dst_check(struct dst_entry *,
606 							   u32));
607 struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie)
608 {
609 	struct dst_entry *dst = __sk_dst_get(sk);
610 
611 	if (dst && READ_ONCE(dst->obsolete) &&
612 	    INDIRECT_CALL_INET(dst->ops->check, ip6_dst_check, ipv4_dst_check,
613 			       dst, cookie) == NULL) {
614 		sk_tx_queue_clear(sk);
615 		WRITE_ONCE(sk->sk_dst_pending_confirm, 0);
616 		RCU_INIT_POINTER(sk->sk_dst_cache, NULL);
617 		dst_release(dst);
618 		return NULL;
619 	}
620 
621 	return dst;
622 }
623 EXPORT_SYMBOL(__sk_dst_check);
624 
625 struct dst_entry *sk_dst_check(struct sock *sk, u32 cookie)
626 {
627 	struct dst_entry *dst = sk_dst_get(sk);
628 
629 	if (dst && READ_ONCE(dst->obsolete) &&
630 	    INDIRECT_CALL_INET(dst->ops->check, ip6_dst_check, ipv4_dst_check,
631 			       dst, cookie) == NULL) {
632 		sk_dst_reset(sk);
633 		dst_release(dst);
634 		return NULL;
635 	}
636 
637 	return dst;
638 }
639 EXPORT_SYMBOL(sk_dst_check);
640 
641 static int sock_bindtoindex_locked(struct sock *sk, int ifindex)
642 {
643 	int ret = -ENOPROTOOPT;
644 #ifdef CONFIG_NETDEVICES
645 	struct net *net = sock_net(sk);
646 
647 	/* Sorry... */
648 	ret = -EPERM;
649 	if (sk->sk_bound_dev_if && !ns_capable(net->user_ns, CAP_NET_RAW))
650 		goto out;
651 
652 	ret = -EINVAL;
653 	if (ifindex < 0)
654 		goto out;
655 
656 	/* Paired with all READ_ONCE() done locklessly. */
657 	WRITE_ONCE(sk->sk_bound_dev_if, ifindex);
658 
659 	if (sk->sk_prot->rehash)
660 		sk->sk_prot->rehash(sk);
661 	sk_dst_reset(sk);
662 
663 	ret = 0;
664 
665 out:
666 #endif
667 
668 	return ret;
669 }
670 
671 int sock_bindtoindex(struct sock *sk, int ifindex, bool lock_sk)
672 {
673 	int ret;
674 
675 	if (lock_sk)
676 		lock_sock(sk);
677 	ret = sock_bindtoindex_locked(sk, ifindex);
678 	if (lock_sk)
679 		release_sock(sk);
680 
681 	return ret;
682 }
683 EXPORT_SYMBOL(sock_bindtoindex);
684 
685 static int sock_setbindtodevice(struct sock *sk, sockptr_t optval, int optlen)
686 {
687 	int ret = -ENOPROTOOPT;
688 #ifdef CONFIG_NETDEVICES
689 	struct net *net = sock_net(sk);
690 	char devname[IFNAMSIZ];
691 	int index;
692 
693 	ret = -EINVAL;
694 	if (optlen < 0)
695 		goto out;
696 
697 	/* Bind this socket to a particular device like "eth0",
698 	 * as specified in the passed interface name. If the
699 	 * name is "" or the option length is zero the socket
700 	 * is not bound.
701 	 */
702 	if (optlen > IFNAMSIZ - 1)
703 		optlen = IFNAMSIZ - 1;
704 	memset(devname, 0, sizeof(devname));
705 
706 	ret = -EFAULT;
707 	if (copy_from_sockptr(devname, optval, optlen))
708 		goto out;
709 
710 	index = 0;
711 	if (devname[0] != '\0') {
712 		struct net_device *dev;
713 
714 		rcu_read_lock();
715 		dev = dev_get_by_name_rcu(net, devname);
716 		if (dev)
717 			index = dev->ifindex;
718 		rcu_read_unlock();
719 		ret = -ENODEV;
720 		if (!dev)
721 			goto out;
722 	}
723 
724 	sockopt_lock_sock(sk);
725 	ret = sock_bindtoindex_locked(sk, index);
726 	sockopt_release_sock(sk);
727 out:
728 #endif
729 
730 	return ret;
731 }
732 
733 static int sock_getbindtodevice(struct sock *sk, sockptr_t optval,
734 				sockptr_t optlen, int len)
735 {
736 	int ret = -ENOPROTOOPT;
737 #ifdef CONFIG_NETDEVICES
738 	int bound_dev_if = READ_ONCE(sk->sk_bound_dev_if);
739 	struct net *net = sock_net(sk);
740 	char devname[IFNAMSIZ];
741 
742 	if (bound_dev_if == 0) {
743 		len = 0;
744 		goto zero;
745 	}
746 
747 	ret = -EINVAL;
748 	if (len < IFNAMSIZ)
749 		goto out;
750 
751 	ret = netdev_get_name(net, devname, bound_dev_if);
752 	if (ret)
753 		goto out;
754 
755 	len = strlen(devname) + 1;
756 
757 	ret = -EFAULT;
758 	if (copy_to_sockptr(optval, devname, len))
759 		goto out;
760 
761 zero:
762 	ret = -EFAULT;
763 	if (copy_to_sockptr(optlen, &len, sizeof(int)))
764 		goto out;
765 
766 	ret = 0;
767 
768 out:
769 #endif
770 
771 	return ret;
772 }
773 
774 bool sk_mc_loop(const struct sock *sk)
775 {
776 	if (dev_recursion_level())
777 		return false;
778 	if (!sk)
779 		return true;
780 	/* IPV6_ADDRFORM can change sk->sk_family under us. */
781 	switch (READ_ONCE(sk->sk_family)) {
782 	case AF_INET:
783 		return inet_test_bit(MC_LOOP, sk);
784 #if IS_ENABLED(CONFIG_IPV6)
785 	case AF_INET6:
786 		return inet6_test_bit(MC6_LOOP, sk);
787 #endif
788 	}
789 	WARN_ON_ONCE(1);
790 	return true;
791 }
792 EXPORT_SYMBOL(sk_mc_loop);
793 
794 void sock_set_reuseaddr(struct sock *sk)
795 {
796 	lock_sock(sk);
797 	sk->sk_reuse = SK_CAN_REUSE;
798 	release_sock(sk);
799 }
800 EXPORT_SYMBOL(sock_set_reuseaddr);
801 
802 void sock_set_reuseport(struct sock *sk)
803 {
804 	lock_sock(sk);
805 	sk->sk_reuseport = true;
806 	release_sock(sk);
807 }
808 EXPORT_SYMBOL(sock_set_reuseport);
809 
810 void sock_no_linger(struct sock *sk)
811 {
812 	lock_sock(sk);
813 	WRITE_ONCE(sk->sk_lingertime, 0);
814 	sock_set_flag(sk, SOCK_LINGER);
815 	release_sock(sk);
816 }
817 EXPORT_SYMBOL(sock_no_linger);
818 
819 void sock_set_priority(struct sock *sk, u32 priority)
820 {
821 	WRITE_ONCE(sk->sk_priority, priority);
822 }
823 EXPORT_SYMBOL(sock_set_priority);
824 
825 void sock_set_sndtimeo(struct sock *sk, s64 secs)
826 {
827 	if (secs && secs < MAX_SCHEDULE_TIMEOUT / HZ - 1)
828 		WRITE_ONCE(sk->sk_sndtimeo, secs * HZ);
829 	else
830 		WRITE_ONCE(sk->sk_sndtimeo, MAX_SCHEDULE_TIMEOUT);
831 }
832 EXPORT_SYMBOL(sock_set_sndtimeo);
833 
834 static void __sock_set_timestamps(struct sock *sk, bool val, bool new, bool ns)
835 {
836 	sock_valbool_flag(sk, SOCK_RCVTSTAMP, val);
837 	sock_valbool_flag(sk, SOCK_RCVTSTAMPNS, val && ns);
838 	if (val)  {
839 		sock_valbool_flag(sk, SOCK_TSTAMP_NEW, new);
840 		sock_enable_timestamp(sk, SOCK_TIMESTAMP);
841 	}
842 }
843 
844 void sock_set_timestamp(struct sock *sk, int optname, bool valbool)
845 {
846 	switch (optname) {
847 	case SO_TIMESTAMP_OLD:
848 		__sock_set_timestamps(sk, valbool, false, false);
849 		break;
850 	case SO_TIMESTAMP_NEW:
851 		__sock_set_timestamps(sk, valbool, true, false);
852 		break;
853 	case SO_TIMESTAMPNS_OLD:
854 		__sock_set_timestamps(sk, valbool, false, true);
855 		break;
856 	case SO_TIMESTAMPNS_NEW:
857 		__sock_set_timestamps(sk, valbool, true, true);
858 		break;
859 	}
860 }
861 
862 static int sock_timestamping_bind_phc(struct sock *sk, int phc_index)
863 {
864 	struct net *net = sock_net(sk);
865 	struct net_device *dev = NULL;
866 	bool match = false;
867 	int *vclock_index;
868 	int i, num;
869 
870 	if (sk->sk_bound_dev_if)
871 		dev = dev_get_by_index(net, sk->sk_bound_dev_if);
872 
873 	if (!dev) {
874 		pr_err("%s: sock not bind to device\n", __func__);
875 		return -EOPNOTSUPP;
876 	}
877 
878 	num = ethtool_get_phc_vclocks(dev, &vclock_index);
879 	dev_put(dev);
880 
881 	for (i = 0; i < num; i++) {
882 		if (*(vclock_index + i) == phc_index) {
883 			match = true;
884 			break;
885 		}
886 	}
887 
888 	if (num > 0)
889 		kfree(vclock_index);
890 
891 	if (!match)
892 		return -EINVAL;
893 
894 	WRITE_ONCE(sk->sk_bind_phc, phc_index);
895 
896 	return 0;
897 }
898 
899 int sock_set_timestamping(struct sock *sk, int optname,
900 			  struct so_timestamping timestamping)
901 {
902 	int val = timestamping.flags;
903 	int ret;
904 
905 	if (val & ~SOF_TIMESTAMPING_MASK)
906 		return -EINVAL;
907 
908 	if (val & SOF_TIMESTAMPING_OPT_ID_TCP &&
909 	    !(val & SOF_TIMESTAMPING_OPT_ID))
910 		return -EINVAL;
911 
912 	if (val & SOF_TIMESTAMPING_OPT_ID &&
913 	    !(sk->sk_tsflags & SOF_TIMESTAMPING_OPT_ID)) {
914 		if (sk_is_tcp(sk)) {
915 			if ((1 << sk->sk_state) &
916 			    (TCPF_CLOSE | TCPF_LISTEN))
917 				return -EINVAL;
918 			if (val & SOF_TIMESTAMPING_OPT_ID_TCP)
919 				atomic_set(&sk->sk_tskey, tcp_sk(sk)->write_seq);
920 			else
921 				atomic_set(&sk->sk_tskey, tcp_sk(sk)->snd_una);
922 		} else {
923 			atomic_set(&sk->sk_tskey, 0);
924 		}
925 	}
926 
927 	if (val & SOF_TIMESTAMPING_OPT_STATS &&
928 	    !(val & SOF_TIMESTAMPING_OPT_TSONLY))
929 		return -EINVAL;
930 
931 	if (val & SOF_TIMESTAMPING_BIND_PHC) {
932 		ret = sock_timestamping_bind_phc(sk, timestamping.bind_phc);
933 		if (ret)
934 			return ret;
935 	}
936 
937 	WRITE_ONCE(sk->sk_tsflags, val);
938 	sock_valbool_flag(sk, SOCK_TSTAMP_NEW, optname == SO_TIMESTAMPING_NEW);
939 	sock_valbool_flag(sk, SOCK_TIMESTAMPING_ANY, !!(val & TSFLAGS_ANY));
940 
941 	if (val & SOF_TIMESTAMPING_RX_SOFTWARE)
942 		sock_enable_timestamp(sk,
943 				      SOCK_TIMESTAMPING_RX_SOFTWARE);
944 	else
945 		sock_disable_timestamp(sk,
946 				       (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE));
947 	return 0;
948 }
949 
950 #if defined(CONFIG_CGROUP_BPF)
951 void bpf_skops_tx_timestamping(struct sock *sk, struct sk_buff *skb, int op)
952 {
953 	struct bpf_sock_ops_kern sock_ops;
954 
955 	memset(&sock_ops, 0, offsetof(struct bpf_sock_ops_kern, temp));
956 	sock_ops.op = op;
957 	sock_ops.is_fullsock = 1;
958 	sock_ops.sk = sk;
959 	bpf_skops_init_skb(&sock_ops, skb, 0);
960 	__cgroup_bpf_run_filter_sock_ops(sk, &sock_ops, CGROUP_SOCK_OPS);
961 }
962 #endif
963 
964 void sock_set_keepalive(struct sock *sk)
965 {
966 	lock_sock(sk);
967 	if (sk->sk_prot->keepalive)
968 		sk->sk_prot->keepalive(sk, true);
969 	sock_valbool_flag(sk, SOCK_KEEPOPEN, true);
970 	release_sock(sk);
971 }
972 EXPORT_SYMBOL(sock_set_keepalive);
973 
974 static void __sock_set_rcvbuf(struct sock *sk, int val)
975 {
976 	/* Ensure val * 2 fits into an int, to prevent max_t() from treating it
977 	 * as a negative value.
978 	 */
979 	val = min_t(int, val, INT_MAX / 2);
980 	sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
981 
982 	/* We double it on the way in to account for "struct sk_buff" etc.
983 	 * overhead.   Applications assume that the SO_RCVBUF setting they make
984 	 * will allow that much actual data to be received on that socket.
985 	 *
986 	 * Applications are unaware that "struct sk_buff" and other overheads
987 	 * allocate from the receive buffer during socket buffer allocation.
988 	 *
989 	 * And after considering the possible alternatives, returning the value
990 	 * we actually used in getsockopt is the most desirable behavior.
991 	 */
992 	WRITE_ONCE(sk->sk_rcvbuf, max_t(int, val * 2, SOCK_MIN_RCVBUF));
993 }
994 
995 void sock_set_rcvbuf(struct sock *sk, int val)
996 {
997 	lock_sock(sk);
998 	__sock_set_rcvbuf(sk, val);
999 	release_sock(sk);
1000 }
1001 EXPORT_SYMBOL(sock_set_rcvbuf);
1002 
1003 static void __sock_set_mark(struct sock *sk, u32 val)
1004 {
1005 	if (val != sk->sk_mark) {
1006 		WRITE_ONCE(sk->sk_mark, val);
1007 		sk_dst_reset(sk);
1008 	}
1009 }
1010 
1011 void sock_set_mark(struct sock *sk, u32 val)
1012 {
1013 	lock_sock(sk);
1014 	__sock_set_mark(sk, val);
1015 	release_sock(sk);
1016 }
1017 EXPORT_SYMBOL(sock_set_mark);
1018 
1019 static void sock_release_reserved_memory(struct sock *sk, int bytes)
1020 {
1021 	/* Round down bytes to multiple of pages */
1022 	bytes = round_down(bytes, PAGE_SIZE);
1023 
1024 	WARN_ON(bytes > sk->sk_reserved_mem);
1025 	WRITE_ONCE(sk->sk_reserved_mem, sk->sk_reserved_mem - bytes);
1026 	sk_mem_reclaim(sk);
1027 }
1028 
1029 static int sock_reserve_memory(struct sock *sk, int bytes)
1030 {
1031 	long allocated;
1032 	bool charged;
1033 	int pages;
1034 
1035 	if (!mem_cgroup_sk_enabled(sk) || !sk_has_account(sk))
1036 		return -EOPNOTSUPP;
1037 
1038 	if (!bytes)
1039 		return 0;
1040 
1041 	pages = sk_mem_pages(bytes);
1042 
1043 	/* pre-charge to memcg */
1044 	charged = mem_cgroup_sk_charge(sk, pages,
1045 				       GFP_KERNEL | __GFP_RETRY_MAYFAIL);
1046 	if (!charged)
1047 		return -ENOMEM;
1048 
1049 	/* pre-charge to forward_alloc */
1050 	sk_memory_allocated_add(sk, pages);
1051 	allocated = sk_memory_allocated(sk);
1052 	/* If the system goes into memory pressure with this
1053 	 * precharge, give up and return error.
1054 	 */
1055 	if (allocated > sk_prot_mem_limits(sk, 1)) {
1056 		sk_memory_allocated_sub(sk, pages);
1057 		mem_cgroup_sk_uncharge(sk, pages);
1058 		return -ENOMEM;
1059 	}
1060 	sk_forward_alloc_add(sk, pages << PAGE_SHIFT);
1061 
1062 	WRITE_ONCE(sk->sk_reserved_mem,
1063 		   sk->sk_reserved_mem + (pages << PAGE_SHIFT));
1064 
1065 	return 0;
1066 }
1067 
1068 #ifdef CONFIG_PAGE_POOL
1069 
1070 /* This is the number of tokens and frags that the user can SO_DEVMEM_DONTNEED
1071  * in 1 syscall. The limit exists to limit the amount of memory the kernel
1072  * allocates to copy these tokens, and to prevent looping over the frags for
1073  * too long.
1074  */
1075 #define MAX_DONTNEED_TOKENS 128
1076 #define MAX_DONTNEED_FRAGS 1024
1077 
1078 static noinline_for_stack int
1079 sock_devmem_dontneed(struct sock *sk, sockptr_t optval, unsigned int optlen)
1080 {
1081 	unsigned int num_tokens, i, j, k, netmem_num = 0;
1082 	struct dmabuf_token *tokens;
1083 	int ret = 0, num_frags = 0;
1084 	netmem_ref netmems[16];
1085 
1086 	if (!sk_is_tcp(sk))
1087 		return -EBADF;
1088 
1089 	if (optlen % sizeof(*tokens) ||
1090 	    optlen > sizeof(*tokens) * MAX_DONTNEED_TOKENS)
1091 		return -EINVAL;
1092 
1093 	num_tokens = optlen / sizeof(*tokens);
1094 	tokens = kvmalloc_array(num_tokens, sizeof(*tokens), GFP_KERNEL);
1095 	if (!tokens)
1096 		return -ENOMEM;
1097 
1098 	if (copy_from_sockptr(tokens, optval, optlen)) {
1099 		kvfree(tokens);
1100 		return -EFAULT;
1101 	}
1102 
1103 	xa_lock_bh(&sk->sk_user_frags);
1104 	for (i = 0; i < num_tokens; i++) {
1105 		for (j = 0; j < tokens[i].token_count; j++) {
1106 			if (++num_frags > MAX_DONTNEED_FRAGS)
1107 				goto frag_limit_reached;
1108 
1109 			netmem_ref netmem = (__force netmem_ref)__xa_erase(
1110 				&sk->sk_user_frags, tokens[i].token_start + j);
1111 
1112 			if (!netmem || WARN_ON_ONCE(!netmem_is_net_iov(netmem)))
1113 				continue;
1114 
1115 			netmems[netmem_num++] = netmem;
1116 			if (netmem_num == ARRAY_SIZE(netmems)) {
1117 				xa_unlock_bh(&sk->sk_user_frags);
1118 				for (k = 0; k < netmem_num; k++)
1119 					WARN_ON_ONCE(!napi_pp_put_page(netmems[k]));
1120 				netmem_num = 0;
1121 				xa_lock_bh(&sk->sk_user_frags);
1122 			}
1123 			ret++;
1124 		}
1125 	}
1126 
1127 frag_limit_reached:
1128 	xa_unlock_bh(&sk->sk_user_frags);
1129 	for (k = 0; k < netmem_num; k++)
1130 		WARN_ON_ONCE(!napi_pp_put_page(netmems[k]));
1131 
1132 	kvfree(tokens);
1133 	return ret;
1134 }
1135 #endif
1136 
1137 void sockopt_lock_sock(struct sock *sk)
1138 {
1139 	/* When current->bpf_ctx is set, the setsockopt is called from
1140 	 * a bpf prog.  bpf has ensured the sk lock has been
1141 	 * acquired before calling setsockopt().
1142 	 */
1143 	if (has_current_bpf_ctx())
1144 		return;
1145 
1146 	lock_sock(sk);
1147 }
1148 EXPORT_SYMBOL(sockopt_lock_sock);
1149 
1150 void sockopt_release_sock(struct sock *sk)
1151 {
1152 	if (has_current_bpf_ctx())
1153 		return;
1154 
1155 	release_sock(sk);
1156 }
1157 EXPORT_SYMBOL(sockopt_release_sock);
1158 
1159 bool sockopt_ns_capable(struct user_namespace *ns, int cap)
1160 {
1161 	return has_current_bpf_ctx() || ns_capable(ns, cap);
1162 }
1163 EXPORT_SYMBOL(sockopt_ns_capable);
1164 
1165 bool sockopt_capable(int cap)
1166 {
1167 	return has_current_bpf_ctx() || capable(cap);
1168 }
1169 EXPORT_SYMBOL(sockopt_capable);
1170 
1171 static int sockopt_validate_clockid(__kernel_clockid_t value)
1172 {
1173 	switch (value) {
1174 	case CLOCK_REALTIME:
1175 	case CLOCK_MONOTONIC:
1176 	case CLOCK_TAI:
1177 		return 0;
1178 	}
1179 	return -EINVAL;
1180 }
1181 
1182 /*
1183  *	This is meant for all protocols to use and covers goings on
1184  *	at the socket level. Everything here is generic.
1185  */
1186 
1187 int sk_setsockopt(struct sock *sk, int level, int optname,
1188 		  sockptr_t optval, unsigned int optlen)
1189 {
1190 	struct so_timestamping timestamping;
1191 	struct socket *sock = sk->sk_socket;
1192 	struct sock_txtime sk_txtime;
1193 	int val;
1194 	int valbool;
1195 	struct linger ling;
1196 	int ret = 0;
1197 
1198 	/*
1199 	 *	Options without arguments
1200 	 */
1201 
1202 	if (optname == SO_BINDTODEVICE)
1203 		return sock_setbindtodevice(sk, optval, optlen);
1204 
1205 	if (optlen < sizeof(int))
1206 		return -EINVAL;
1207 
1208 	if (copy_from_sockptr(&val, optval, sizeof(val)))
1209 		return -EFAULT;
1210 
1211 	valbool = val ? 1 : 0;
1212 
1213 	/* handle options which do not require locking the socket. */
1214 	switch (optname) {
1215 	case SO_PRIORITY:
1216 		if (sk_set_prio_allowed(sk, val)) {
1217 			sock_set_priority(sk, val);
1218 			return 0;
1219 		}
1220 		return -EPERM;
1221 	case SO_TYPE:
1222 	case SO_PROTOCOL:
1223 	case SO_DOMAIN:
1224 	case SO_ERROR:
1225 		return -ENOPROTOOPT;
1226 #ifdef CONFIG_NET_RX_BUSY_POLL
1227 	case SO_BUSY_POLL:
1228 		if (val < 0)
1229 			return -EINVAL;
1230 		WRITE_ONCE(sk->sk_ll_usec, val);
1231 		return 0;
1232 	case SO_PREFER_BUSY_POLL:
1233 		if (valbool && !sockopt_capable(CAP_NET_ADMIN))
1234 			return -EPERM;
1235 		WRITE_ONCE(sk->sk_prefer_busy_poll, valbool);
1236 		return 0;
1237 	case SO_BUSY_POLL_BUDGET:
1238 		if (val > READ_ONCE(sk->sk_busy_poll_budget) &&
1239 		    !sockopt_capable(CAP_NET_ADMIN))
1240 			return -EPERM;
1241 		if (val < 0 || val > U16_MAX)
1242 			return -EINVAL;
1243 		WRITE_ONCE(sk->sk_busy_poll_budget, val);
1244 		return 0;
1245 #endif
1246 	case SO_MAX_PACING_RATE:
1247 		{
1248 		unsigned long ulval = (val == ~0U) ? ~0UL : (unsigned int)val;
1249 		unsigned long pacing_rate;
1250 
1251 		if (sizeof(ulval) != sizeof(val) &&
1252 		    optlen >= sizeof(ulval) &&
1253 		    copy_from_sockptr(&ulval, optval, sizeof(ulval))) {
1254 			return -EFAULT;
1255 		}
1256 		if (ulval != ~0UL)
1257 			cmpxchg(&sk->sk_pacing_status,
1258 				SK_PACING_NONE,
1259 				SK_PACING_NEEDED);
1260 		/* Pairs with READ_ONCE() from sk_getsockopt() */
1261 		WRITE_ONCE(sk->sk_max_pacing_rate, ulval);
1262 		pacing_rate = READ_ONCE(sk->sk_pacing_rate);
1263 		if (ulval < pacing_rate)
1264 			WRITE_ONCE(sk->sk_pacing_rate, ulval);
1265 		return 0;
1266 		}
1267 	case SO_TXREHASH:
1268 		if (!sk_is_tcp(sk))
1269 			return -EOPNOTSUPP;
1270 		if (val < -1 || val > 1)
1271 			return -EINVAL;
1272 		if ((u8)val == SOCK_TXREHASH_DEFAULT)
1273 			val = READ_ONCE(sock_net(sk)->core.sysctl_txrehash);
1274 		/* Paired with READ_ONCE() in tcp_rtx_synack()
1275 		 * and sk_getsockopt().
1276 		 */
1277 		WRITE_ONCE(sk->sk_txrehash, (u8)val);
1278 		return 0;
1279 	case SO_PEEK_OFF:
1280 		{
1281 		int (*set_peek_off)(struct sock *sk, int val);
1282 
1283 		set_peek_off = READ_ONCE(sock->ops)->set_peek_off;
1284 		if (set_peek_off)
1285 			ret = set_peek_off(sk, val);
1286 		else
1287 			ret = -EOPNOTSUPP;
1288 		return ret;
1289 		}
1290 #ifdef CONFIG_PAGE_POOL
1291 	case SO_DEVMEM_DONTNEED:
1292 		return sock_devmem_dontneed(sk, optval, optlen);
1293 #endif
1294 	case SO_SNDTIMEO_OLD:
1295 	case SO_SNDTIMEO_NEW:
1296 		return sock_set_timeout(&sk->sk_sndtimeo, optval,
1297 					optlen, optname == SO_SNDTIMEO_OLD);
1298 	case SO_RCVTIMEO_OLD:
1299 	case SO_RCVTIMEO_NEW:
1300 		return sock_set_timeout(&sk->sk_rcvtimeo, optval,
1301 					optlen, optname == SO_RCVTIMEO_OLD);
1302 	}
1303 
1304 	sockopt_lock_sock(sk);
1305 
1306 	switch (optname) {
1307 	case SO_DEBUG:
1308 		if (val && !sockopt_capable(CAP_NET_ADMIN))
1309 			ret = -EACCES;
1310 		else
1311 			sock_valbool_flag(sk, SOCK_DBG, valbool);
1312 		break;
1313 	case SO_REUSEADDR:
1314 		sk->sk_reuse = (valbool ? SK_CAN_REUSE : SK_NO_REUSE);
1315 		break;
1316 	case SO_REUSEPORT:
1317 		if (valbool && !sk_is_inet(sk))
1318 			ret = -EOPNOTSUPP;
1319 		else
1320 			sk->sk_reuseport = valbool;
1321 		break;
1322 	case SO_DONTROUTE:
1323 		sock_valbool_flag(sk, SOCK_LOCALROUTE, valbool);
1324 		sk_dst_reset(sk);
1325 		break;
1326 	case SO_BROADCAST:
1327 		sock_valbool_flag(sk, SOCK_BROADCAST, valbool);
1328 		break;
1329 	case SO_SNDBUF:
1330 		/* Don't error on this BSD doesn't and if you think
1331 		 * about it this is right. Otherwise apps have to
1332 		 * play 'guess the biggest size' games. RCVBUF/SNDBUF
1333 		 * are treated in BSD as hints
1334 		 */
1335 		val = min_t(u32, val, READ_ONCE(sysctl_wmem_max));
1336 set_sndbuf:
1337 		/* Ensure val * 2 fits into an int, to prevent max_t()
1338 		 * from treating it as a negative value.
1339 		 */
1340 		val = min_t(int, val, INT_MAX / 2);
1341 		sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
1342 		WRITE_ONCE(sk->sk_sndbuf,
1343 			   max_t(int, val * 2, SOCK_MIN_SNDBUF));
1344 		/* Wake up sending tasks if we upped the value. */
1345 		sk->sk_write_space(sk);
1346 		break;
1347 
1348 	case SO_SNDBUFFORCE:
1349 		if (!sockopt_capable(CAP_NET_ADMIN)) {
1350 			ret = -EPERM;
1351 			break;
1352 		}
1353 
1354 		/* No negative values (to prevent underflow, as val will be
1355 		 * multiplied by 2).
1356 		 */
1357 		if (val < 0)
1358 			val = 0;
1359 		goto set_sndbuf;
1360 
1361 	case SO_RCVBUF:
1362 		/* Don't error on this BSD doesn't and if you think
1363 		 * about it this is right. Otherwise apps have to
1364 		 * play 'guess the biggest size' games. RCVBUF/SNDBUF
1365 		 * are treated in BSD as hints
1366 		 */
1367 		__sock_set_rcvbuf(sk, min_t(u32, val, READ_ONCE(sysctl_rmem_max)));
1368 		break;
1369 
1370 	case SO_RCVBUFFORCE:
1371 		if (!sockopt_capable(CAP_NET_ADMIN)) {
1372 			ret = -EPERM;
1373 			break;
1374 		}
1375 
1376 		/* No negative values (to prevent underflow, as val will be
1377 		 * multiplied by 2).
1378 		 */
1379 		__sock_set_rcvbuf(sk, max(val, 0));
1380 		break;
1381 
1382 	case SO_KEEPALIVE:
1383 		if (sk->sk_prot->keepalive)
1384 			sk->sk_prot->keepalive(sk, valbool);
1385 		sock_valbool_flag(sk, SOCK_KEEPOPEN, valbool);
1386 		break;
1387 
1388 	case SO_OOBINLINE:
1389 		sock_valbool_flag(sk, SOCK_URGINLINE, valbool);
1390 		break;
1391 
1392 	case SO_NO_CHECK:
1393 		sk->sk_no_check_tx = valbool;
1394 		break;
1395 
1396 	case SO_LINGER:
1397 		if (optlen < sizeof(ling)) {
1398 			ret = -EINVAL;	/* 1003.1g */
1399 			break;
1400 		}
1401 		if (copy_from_sockptr(&ling, optval, sizeof(ling))) {
1402 			ret = -EFAULT;
1403 			break;
1404 		}
1405 		if (!ling.l_onoff) {
1406 			sock_reset_flag(sk, SOCK_LINGER);
1407 		} else {
1408 			unsigned long t_sec = ling.l_linger;
1409 
1410 			if (t_sec >= MAX_SCHEDULE_TIMEOUT / HZ)
1411 				WRITE_ONCE(sk->sk_lingertime, MAX_SCHEDULE_TIMEOUT);
1412 			else
1413 				WRITE_ONCE(sk->sk_lingertime, t_sec * HZ);
1414 			sock_set_flag(sk, SOCK_LINGER);
1415 		}
1416 		break;
1417 
1418 	case SO_BSDCOMPAT:
1419 		break;
1420 
1421 	case SO_TIMESTAMP_OLD:
1422 	case SO_TIMESTAMP_NEW:
1423 	case SO_TIMESTAMPNS_OLD:
1424 	case SO_TIMESTAMPNS_NEW:
1425 		sock_set_timestamp(sk, optname, valbool);
1426 		break;
1427 
1428 	case SO_TIMESTAMPING_NEW:
1429 	case SO_TIMESTAMPING_OLD:
1430 		if (optlen == sizeof(timestamping)) {
1431 			if (copy_from_sockptr(&timestamping, optval,
1432 					      sizeof(timestamping))) {
1433 				ret = -EFAULT;
1434 				break;
1435 			}
1436 		} else {
1437 			memset(&timestamping, 0, sizeof(timestamping));
1438 			timestamping.flags = val;
1439 		}
1440 		ret = sock_set_timestamping(sk, optname, timestamping);
1441 		break;
1442 
1443 	case SO_RCVLOWAT:
1444 		{
1445 		int (*set_rcvlowat)(struct sock *sk, int val) = NULL;
1446 
1447 		if (val < 0)
1448 			val = INT_MAX;
1449 		if (sock)
1450 			set_rcvlowat = READ_ONCE(sock->ops)->set_rcvlowat;
1451 		if (set_rcvlowat)
1452 			ret = set_rcvlowat(sk, val);
1453 		else
1454 			WRITE_ONCE(sk->sk_rcvlowat, val ? : 1);
1455 		break;
1456 		}
1457 	case SO_ATTACH_FILTER: {
1458 		struct sock_fprog fprog;
1459 
1460 		ret = copy_bpf_fprog_from_user(&fprog, optval, optlen);
1461 		if (!ret)
1462 			ret = sk_attach_filter(&fprog, sk);
1463 		break;
1464 	}
1465 	case SO_ATTACH_BPF:
1466 		ret = -EINVAL;
1467 		if (optlen == sizeof(u32)) {
1468 			u32 ufd;
1469 
1470 			ret = -EFAULT;
1471 			if (copy_from_sockptr(&ufd, optval, sizeof(ufd)))
1472 				break;
1473 
1474 			ret = sk_attach_bpf(ufd, sk);
1475 		}
1476 		break;
1477 
1478 	case SO_ATTACH_REUSEPORT_CBPF: {
1479 		struct sock_fprog fprog;
1480 
1481 		ret = copy_bpf_fprog_from_user(&fprog, optval, optlen);
1482 		if (!ret)
1483 			ret = sk_reuseport_attach_filter(&fprog, sk);
1484 		break;
1485 	}
1486 	case SO_ATTACH_REUSEPORT_EBPF:
1487 		ret = -EINVAL;
1488 		if (optlen == sizeof(u32)) {
1489 			u32 ufd;
1490 
1491 			ret = -EFAULT;
1492 			if (copy_from_sockptr(&ufd, optval, sizeof(ufd)))
1493 				break;
1494 
1495 			ret = sk_reuseport_attach_bpf(ufd, sk);
1496 		}
1497 		break;
1498 
1499 	case SO_DETACH_REUSEPORT_BPF:
1500 		ret = reuseport_detach_prog(sk);
1501 		break;
1502 
1503 	case SO_DETACH_FILTER:
1504 		ret = sk_detach_filter(sk);
1505 		break;
1506 
1507 	case SO_LOCK_FILTER:
1508 		if (sock_flag(sk, SOCK_FILTER_LOCKED) && !valbool)
1509 			ret = -EPERM;
1510 		else
1511 			sock_valbool_flag(sk, SOCK_FILTER_LOCKED, valbool);
1512 		break;
1513 
1514 	case SO_MARK:
1515 		if (!sockopt_ns_capable(sock_net(sk)->user_ns, CAP_NET_RAW) &&
1516 		    !sockopt_ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) {
1517 			ret = -EPERM;
1518 			break;
1519 		}
1520 
1521 		__sock_set_mark(sk, val);
1522 		break;
1523 	case SO_RCVMARK:
1524 		sock_valbool_flag(sk, SOCK_RCVMARK, valbool);
1525 		break;
1526 
1527 	case SO_RCVPRIORITY:
1528 		sock_valbool_flag(sk, SOCK_RCVPRIORITY, valbool);
1529 		break;
1530 
1531 	case SO_RXQ_OVFL:
1532 		sock_valbool_flag(sk, SOCK_RXQ_OVFL, valbool);
1533 		break;
1534 
1535 	case SO_WIFI_STATUS:
1536 		sock_valbool_flag(sk, SOCK_WIFI_STATUS, valbool);
1537 		break;
1538 
1539 	case SO_NOFCS:
1540 		sock_valbool_flag(sk, SOCK_NOFCS, valbool);
1541 		break;
1542 
1543 	case SO_SELECT_ERR_QUEUE:
1544 		sock_valbool_flag(sk, SOCK_SELECT_ERR_QUEUE, valbool);
1545 		break;
1546 
1547 	case SO_PASSCRED:
1548 		if (sk_may_scm_recv(sk))
1549 			sk->sk_scm_credentials = valbool;
1550 		else
1551 			ret = -EOPNOTSUPP;
1552 		break;
1553 
1554 	case SO_PASSSEC:
1555 		if (IS_ENABLED(CONFIG_SECURITY_NETWORK) && sk_may_scm_recv(sk))
1556 			sk->sk_scm_security = valbool;
1557 		else
1558 			ret = -EOPNOTSUPP;
1559 		break;
1560 
1561 	case SO_PASSPIDFD:
1562 		if (sk_is_unix(sk))
1563 			sk->sk_scm_pidfd = valbool;
1564 		else
1565 			ret = -EOPNOTSUPP;
1566 		break;
1567 
1568 	case SO_PASSRIGHTS:
1569 		if (sk_is_unix(sk))
1570 			sk->sk_scm_rights = valbool;
1571 		else
1572 			ret = -EOPNOTSUPP;
1573 		break;
1574 
1575 	case SO_INCOMING_CPU:
1576 		reuseport_update_incoming_cpu(sk, val);
1577 		break;
1578 
1579 	case SO_CNX_ADVICE:
1580 		if (val == 1)
1581 			dst_negative_advice(sk);
1582 		break;
1583 
1584 	case SO_ZEROCOPY:
1585 		if (sk->sk_family == PF_INET || sk->sk_family == PF_INET6) {
1586 			if (!(sk_is_tcp(sk) ||
1587 			      (sk->sk_type == SOCK_DGRAM &&
1588 			       sk->sk_protocol == IPPROTO_UDP)))
1589 				ret = -EOPNOTSUPP;
1590 		} else if (sk->sk_family != PF_RDS) {
1591 			ret = -EOPNOTSUPP;
1592 		}
1593 		if (!ret) {
1594 			if (val < 0 || val > 1)
1595 				ret = -EINVAL;
1596 			else
1597 				sock_valbool_flag(sk, SOCK_ZEROCOPY, valbool);
1598 		}
1599 		break;
1600 
1601 	case SO_TXTIME:
1602 		if (optlen != sizeof(struct sock_txtime)) {
1603 			ret = -EINVAL;
1604 			break;
1605 		} else if (copy_from_sockptr(&sk_txtime, optval,
1606 			   sizeof(struct sock_txtime))) {
1607 			ret = -EFAULT;
1608 			break;
1609 		} else if (sk_txtime.flags & ~SOF_TXTIME_FLAGS_MASK) {
1610 			ret = -EINVAL;
1611 			break;
1612 		}
1613 		/* CLOCK_MONOTONIC is only used by sch_fq, and this packet
1614 		 * scheduler has enough safe guards.
1615 		 */
1616 		if (sk_txtime.clockid != CLOCK_MONOTONIC &&
1617 		    !sockopt_ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) {
1618 			ret = -EPERM;
1619 			break;
1620 		}
1621 
1622 		ret = sockopt_validate_clockid(sk_txtime.clockid);
1623 		if (ret)
1624 			break;
1625 
1626 		sock_valbool_flag(sk, SOCK_TXTIME, true);
1627 		sk->sk_clockid = sk_txtime.clockid;
1628 		sk->sk_txtime_deadline_mode =
1629 			!!(sk_txtime.flags & SOF_TXTIME_DEADLINE_MODE);
1630 		sk->sk_txtime_report_errors =
1631 			!!(sk_txtime.flags & SOF_TXTIME_REPORT_ERRORS);
1632 		break;
1633 
1634 	case SO_BINDTOIFINDEX:
1635 		ret = sock_bindtoindex_locked(sk, val);
1636 		break;
1637 
1638 	case SO_BUF_LOCK:
1639 		if (val & ~SOCK_BUF_LOCK_MASK) {
1640 			ret = -EINVAL;
1641 			break;
1642 		}
1643 		sk->sk_userlocks = val | (sk->sk_userlocks &
1644 					  ~SOCK_BUF_LOCK_MASK);
1645 		break;
1646 
1647 	case SO_RESERVE_MEM:
1648 	{
1649 		int delta;
1650 
1651 		if (val < 0) {
1652 			ret = -EINVAL;
1653 			break;
1654 		}
1655 
1656 		delta = val - sk->sk_reserved_mem;
1657 		if (delta < 0)
1658 			sock_release_reserved_memory(sk, -delta);
1659 		else
1660 			ret = sock_reserve_memory(sk, delta);
1661 		break;
1662 	}
1663 
1664 	default:
1665 		ret = -ENOPROTOOPT;
1666 		break;
1667 	}
1668 	sockopt_release_sock(sk);
1669 	return ret;
1670 }
1671 
1672 int sock_setsockopt(struct socket *sock, int level, int optname,
1673 		    sockptr_t optval, unsigned int optlen)
1674 {
1675 	return sk_setsockopt(sock->sk, level, optname,
1676 			     optval, optlen);
1677 }
1678 EXPORT_SYMBOL(sock_setsockopt);
1679 
1680 static const struct cred *sk_get_peer_cred(struct sock *sk)
1681 {
1682 	const struct cred *cred;
1683 
1684 	spin_lock(&sk->sk_peer_lock);
1685 	cred = get_cred(sk->sk_peer_cred);
1686 	spin_unlock(&sk->sk_peer_lock);
1687 
1688 	return cred;
1689 }
1690 
1691 static void cred_to_ucred(struct pid *pid, const struct cred *cred,
1692 			  struct ucred *ucred)
1693 {
1694 	ucred->pid = pid_vnr(pid);
1695 	ucred->uid = ucred->gid = -1;
1696 	if (cred) {
1697 		struct user_namespace *current_ns = current_user_ns();
1698 
1699 		ucred->uid = from_kuid_munged(current_ns, cred->euid);
1700 		ucred->gid = from_kgid_munged(current_ns, cred->egid);
1701 	}
1702 }
1703 
1704 static int groups_to_user(sockptr_t dst, const struct group_info *src)
1705 {
1706 	struct user_namespace *user_ns = current_user_ns();
1707 	int i;
1708 
1709 	for (i = 0; i < src->ngroups; i++) {
1710 		gid_t gid = from_kgid_munged(user_ns, src->gid[i]);
1711 
1712 		if (copy_to_sockptr_offset(dst, i * sizeof(gid), &gid, sizeof(gid)))
1713 			return -EFAULT;
1714 	}
1715 
1716 	return 0;
1717 }
1718 
1719 int sk_getsockopt(struct sock *sk, int level, int optname,
1720 		  sockptr_t optval, sockptr_t optlen)
1721 {
1722 	struct socket *sock = sk->sk_socket;
1723 
1724 	union {
1725 		int val;
1726 		u64 val64;
1727 		unsigned long ulval;
1728 		struct linger ling;
1729 		struct old_timeval32 tm32;
1730 		struct __kernel_old_timeval tm;
1731 		struct  __kernel_sock_timeval stm;
1732 		struct sock_txtime txtime;
1733 		struct so_timestamping timestamping;
1734 	} v;
1735 
1736 	int lv = sizeof(int);
1737 	int len;
1738 
1739 	if (copy_from_sockptr(&len, optlen, sizeof(int)))
1740 		return -EFAULT;
1741 	if (len < 0)
1742 		return -EINVAL;
1743 
1744 	memset(&v, 0, sizeof(v));
1745 
1746 	switch (optname) {
1747 	case SO_DEBUG:
1748 		v.val = sock_flag(sk, SOCK_DBG);
1749 		break;
1750 
1751 	case SO_DONTROUTE:
1752 		v.val = sock_flag(sk, SOCK_LOCALROUTE);
1753 		break;
1754 
1755 	case SO_BROADCAST:
1756 		v.val = sock_flag(sk, SOCK_BROADCAST);
1757 		break;
1758 
1759 	case SO_SNDBUF:
1760 		v.val = READ_ONCE(sk->sk_sndbuf);
1761 		break;
1762 
1763 	case SO_RCVBUF:
1764 		v.val = READ_ONCE(sk->sk_rcvbuf);
1765 		break;
1766 
1767 	case SO_REUSEADDR:
1768 		v.val = sk->sk_reuse;
1769 		break;
1770 
1771 	case SO_REUSEPORT:
1772 		v.val = sk->sk_reuseport;
1773 		break;
1774 
1775 	case SO_KEEPALIVE:
1776 		v.val = sock_flag(sk, SOCK_KEEPOPEN);
1777 		break;
1778 
1779 	case SO_TYPE:
1780 		v.val = sk->sk_type;
1781 		break;
1782 
1783 	case SO_PROTOCOL:
1784 		v.val = sk->sk_protocol;
1785 		break;
1786 
1787 	case SO_DOMAIN:
1788 		v.val = sk->sk_family;
1789 		break;
1790 
1791 	case SO_ERROR:
1792 		v.val = -sock_error(sk);
1793 		if (v.val == 0)
1794 			v.val = xchg(&sk->sk_err_soft, 0);
1795 		break;
1796 
1797 	case SO_OOBINLINE:
1798 		v.val = sock_flag(sk, SOCK_URGINLINE);
1799 		break;
1800 
1801 	case SO_NO_CHECK:
1802 		v.val = sk->sk_no_check_tx;
1803 		break;
1804 
1805 	case SO_PRIORITY:
1806 		v.val = READ_ONCE(sk->sk_priority);
1807 		break;
1808 
1809 	case SO_LINGER:
1810 		lv		= sizeof(v.ling);
1811 		v.ling.l_onoff	= sock_flag(sk, SOCK_LINGER);
1812 		v.ling.l_linger	= READ_ONCE(sk->sk_lingertime) / HZ;
1813 		break;
1814 
1815 	case SO_BSDCOMPAT:
1816 		break;
1817 
1818 	case SO_TIMESTAMP_OLD:
1819 		v.val = sock_flag(sk, SOCK_RCVTSTAMP) &&
1820 				!sock_flag(sk, SOCK_TSTAMP_NEW) &&
1821 				!sock_flag(sk, SOCK_RCVTSTAMPNS);
1822 		break;
1823 
1824 	case SO_TIMESTAMPNS_OLD:
1825 		v.val = sock_flag(sk, SOCK_RCVTSTAMPNS) && !sock_flag(sk, SOCK_TSTAMP_NEW);
1826 		break;
1827 
1828 	case SO_TIMESTAMP_NEW:
1829 		v.val = sock_flag(sk, SOCK_RCVTSTAMP) && sock_flag(sk, SOCK_TSTAMP_NEW);
1830 		break;
1831 
1832 	case SO_TIMESTAMPNS_NEW:
1833 		v.val = sock_flag(sk, SOCK_RCVTSTAMPNS) && sock_flag(sk, SOCK_TSTAMP_NEW);
1834 		break;
1835 
1836 	case SO_TIMESTAMPING_OLD:
1837 	case SO_TIMESTAMPING_NEW:
1838 		lv = sizeof(v.timestamping);
1839 		/* For the later-added case SO_TIMESTAMPING_NEW: Be strict about only
1840 		 * returning the flags when they were set through the same option.
1841 		 * Don't change the beviour for the old case SO_TIMESTAMPING_OLD.
1842 		 */
1843 		if (optname == SO_TIMESTAMPING_OLD || sock_flag(sk, SOCK_TSTAMP_NEW)) {
1844 			v.timestamping.flags = READ_ONCE(sk->sk_tsflags);
1845 			v.timestamping.bind_phc = READ_ONCE(sk->sk_bind_phc);
1846 		}
1847 		break;
1848 
1849 	case SO_RCVTIMEO_OLD:
1850 	case SO_RCVTIMEO_NEW:
1851 		lv = sock_get_timeout(READ_ONCE(sk->sk_rcvtimeo), &v,
1852 				      SO_RCVTIMEO_OLD == optname);
1853 		break;
1854 
1855 	case SO_SNDTIMEO_OLD:
1856 	case SO_SNDTIMEO_NEW:
1857 		lv = sock_get_timeout(READ_ONCE(sk->sk_sndtimeo), &v,
1858 				      SO_SNDTIMEO_OLD == optname);
1859 		break;
1860 
1861 	case SO_RCVLOWAT:
1862 		v.val = READ_ONCE(sk->sk_rcvlowat);
1863 		break;
1864 
1865 	case SO_SNDLOWAT:
1866 		v.val = 1;
1867 		break;
1868 
1869 	case SO_PASSCRED:
1870 		if (!sk_may_scm_recv(sk))
1871 			return -EOPNOTSUPP;
1872 
1873 		v.val = sk->sk_scm_credentials;
1874 		break;
1875 
1876 	case SO_PASSPIDFD:
1877 		if (!sk_is_unix(sk))
1878 			return -EOPNOTSUPP;
1879 
1880 		v.val = sk->sk_scm_pidfd;
1881 		break;
1882 
1883 	case SO_PASSRIGHTS:
1884 		if (!sk_is_unix(sk))
1885 			return -EOPNOTSUPP;
1886 
1887 		v.val = sk->sk_scm_rights;
1888 		break;
1889 
1890 	case SO_PEERCRED:
1891 	{
1892 		struct ucred peercred;
1893 		if (len > sizeof(peercred))
1894 			len = sizeof(peercred);
1895 
1896 		spin_lock(&sk->sk_peer_lock);
1897 		cred_to_ucred(sk->sk_peer_pid, sk->sk_peer_cred, &peercred);
1898 		spin_unlock(&sk->sk_peer_lock);
1899 
1900 		if (copy_to_sockptr(optval, &peercred, len))
1901 			return -EFAULT;
1902 		goto lenout;
1903 	}
1904 
1905 	case SO_PEERPIDFD:
1906 	{
1907 		struct pid *peer_pid;
1908 		struct file *pidfd_file = NULL;
1909 		unsigned int flags = 0;
1910 		int pidfd;
1911 
1912 		if (len > sizeof(pidfd))
1913 			len = sizeof(pidfd);
1914 
1915 		spin_lock(&sk->sk_peer_lock);
1916 		peer_pid = get_pid(sk->sk_peer_pid);
1917 		spin_unlock(&sk->sk_peer_lock);
1918 
1919 		if (!peer_pid)
1920 			return -ENODATA;
1921 
1922 		/* The use of PIDFD_STALE requires stashing of struct pid
1923 		 * on pidfs with pidfs_register_pid() and only AF_UNIX
1924 		 * were prepared for this.
1925 		 */
1926 		if (sk->sk_family == AF_UNIX)
1927 			flags = PIDFD_STALE;
1928 
1929 		pidfd = pidfd_prepare(peer_pid, flags, &pidfd_file);
1930 		put_pid(peer_pid);
1931 		if (pidfd < 0)
1932 			return pidfd;
1933 
1934 		if (copy_to_sockptr(optval, &pidfd, len) ||
1935 		    copy_to_sockptr(optlen, &len, sizeof(int))) {
1936 			put_unused_fd(pidfd);
1937 			fput(pidfd_file);
1938 
1939 			return -EFAULT;
1940 		}
1941 
1942 		fd_install(pidfd, pidfd_file);
1943 		return 0;
1944 	}
1945 
1946 	case SO_PEERGROUPS:
1947 	{
1948 		const struct cred *cred;
1949 		int ret, n;
1950 
1951 		cred = sk_get_peer_cred(sk);
1952 		if (!cred)
1953 			return -ENODATA;
1954 
1955 		n = cred->group_info->ngroups;
1956 		if (len < n * sizeof(gid_t)) {
1957 			len = n * sizeof(gid_t);
1958 			put_cred(cred);
1959 			return copy_to_sockptr(optlen, &len, sizeof(int)) ? -EFAULT : -ERANGE;
1960 		}
1961 		len = n * sizeof(gid_t);
1962 
1963 		ret = groups_to_user(optval, cred->group_info);
1964 		put_cred(cred);
1965 		if (ret)
1966 			return ret;
1967 		goto lenout;
1968 	}
1969 
1970 	case SO_PEERNAME:
1971 	{
1972 		struct sockaddr_storage address;
1973 
1974 		lv = READ_ONCE(sock->ops)->getname(sock, (struct sockaddr *)&address, 2);
1975 		if (lv < 0)
1976 			return -ENOTCONN;
1977 		if (lv < len)
1978 			return -EINVAL;
1979 		if (copy_to_sockptr(optval, &address, len))
1980 			return -EFAULT;
1981 		goto lenout;
1982 	}
1983 
1984 	/* Dubious BSD thing... Probably nobody even uses it, but
1985 	 * the UNIX standard wants it for whatever reason... -DaveM
1986 	 */
1987 	case SO_ACCEPTCONN:
1988 		v.val = sk->sk_state == TCP_LISTEN;
1989 		break;
1990 
1991 	case SO_PASSSEC:
1992 		if (!IS_ENABLED(CONFIG_SECURITY_NETWORK) || !sk_may_scm_recv(sk))
1993 			return -EOPNOTSUPP;
1994 
1995 		v.val = sk->sk_scm_security;
1996 		break;
1997 
1998 	case SO_PEERSEC:
1999 		return security_socket_getpeersec_stream(sock,
2000 							 optval, optlen, len);
2001 
2002 	case SO_MARK:
2003 		v.val = READ_ONCE(sk->sk_mark);
2004 		break;
2005 
2006 	case SO_RCVMARK:
2007 		v.val = sock_flag(sk, SOCK_RCVMARK);
2008 		break;
2009 
2010 	case SO_RCVPRIORITY:
2011 		v.val = sock_flag(sk, SOCK_RCVPRIORITY);
2012 		break;
2013 
2014 	case SO_RXQ_OVFL:
2015 		v.val = sock_flag(sk, SOCK_RXQ_OVFL);
2016 		break;
2017 
2018 	case SO_WIFI_STATUS:
2019 		v.val = sock_flag(sk, SOCK_WIFI_STATUS);
2020 		break;
2021 
2022 	case SO_PEEK_OFF:
2023 		if (!READ_ONCE(sock->ops)->set_peek_off)
2024 			return -EOPNOTSUPP;
2025 
2026 		v.val = READ_ONCE(sk->sk_peek_off);
2027 		break;
2028 	case SO_NOFCS:
2029 		v.val = sock_flag(sk, SOCK_NOFCS);
2030 		break;
2031 
2032 	case SO_BINDTODEVICE:
2033 		return sock_getbindtodevice(sk, optval, optlen, len);
2034 
2035 	case SO_GET_FILTER:
2036 		len = sk_get_filter(sk, optval, len);
2037 		if (len < 0)
2038 			return len;
2039 
2040 		goto lenout;
2041 
2042 	case SO_LOCK_FILTER:
2043 		v.val = sock_flag(sk, SOCK_FILTER_LOCKED);
2044 		break;
2045 
2046 	case SO_BPF_EXTENSIONS:
2047 		v.val = bpf_tell_extensions();
2048 		break;
2049 
2050 	case SO_SELECT_ERR_QUEUE:
2051 		v.val = sock_flag(sk, SOCK_SELECT_ERR_QUEUE);
2052 		break;
2053 
2054 #ifdef CONFIG_NET_RX_BUSY_POLL
2055 	case SO_BUSY_POLL:
2056 		v.val = READ_ONCE(sk->sk_ll_usec);
2057 		break;
2058 	case SO_PREFER_BUSY_POLL:
2059 		v.val = READ_ONCE(sk->sk_prefer_busy_poll);
2060 		break;
2061 #endif
2062 
2063 	case SO_MAX_PACING_RATE:
2064 		/* The READ_ONCE() pair with the WRITE_ONCE() in sk_setsockopt() */
2065 		if (sizeof(v.ulval) != sizeof(v.val) && len >= sizeof(v.ulval)) {
2066 			lv = sizeof(v.ulval);
2067 			v.ulval = READ_ONCE(sk->sk_max_pacing_rate);
2068 		} else {
2069 			/* 32bit version */
2070 			v.val = min_t(unsigned long, ~0U,
2071 				      READ_ONCE(sk->sk_max_pacing_rate));
2072 		}
2073 		break;
2074 
2075 	case SO_INCOMING_CPU:
2076 		v.val = READ_ONCE(sk->sk_incoming_cpu);
2077 		break;
2078 
2079 	case SO_MEMINFO:
2080 	{
2081 		u32 meminfo[SK_MEMINFO_VARS];
2082 
2083 		sk_get_meminfo(sk, meminfo);
2084 
2085 		len = min_t(unsigned int, len, sizeof(meminfo));
2086 		if (copy_to_sockptr(optval, &meminfo, len))
2087 			return -EFAULT;
2088 
2089 		goto lenout;
2090 	}
2091 
2092 #ifdef CONFIG_NET_RX_BUSY_POLL
2093 	case SO_INCOMING_NAPI_ID:
2094 		v.val = READ_ONCE(sk->sk_napi_id);
2095 
2096 		/* aggregate non-NAPI IDs down to 0 */
2097 		if (!napi_id_valid(v.val))
2098 			v.val = 0;
2099 
2100 		break;
2101 #endif
2102 
2103 	case SO_COOKIE:
2104 		lv = sizeof(u64);
2105 		if (len < lv)
2106 			return -EINVAL;
2107 		v.val64 = sock_gen_cookie(sk);
2108 		break;
2109 
2110 	case SO_ZEROCOPY:
2111 		v.val = sock_flag(sk, SOCK_ZEROCOPY);
2112 		break;
2113 
2114 	case SO_TXTIME:
2115 		lv = sizeof(v.txtime);
2116 		v.txtime.clockid = sk->sk_clockid;
2117 		v.txtime.flags |= sk->sk_txtime_deadline_mode ?
2118 				  SOF_TXTIME_DEADLINE_MODE : 0;
2119 		v.txtime.flags |= sk->sk_txtime_report_errors ?
2120 				  SOF_TXTIME_REPORT_ERRORS : 0;
2121 		break;
2122 
2123 	case SO_BINDTOIFINDEX:
2124 		v.val = READ_ONCE(sk->sk_bound_dev_if);
2125 		break;
2126 
2127 	case SO_NETNS_COOKIE:
2128 		lv = sizeof(u64);
2129 		if (len != lv)
2130 			return -EINVAL;
2131 		v.val64 = sock_net(sk)->net_cookie;
2132 		break;
2133 
2134 	case SO_BUF_LOCK:
2135 		v.val = sk->sk_userlocks & SOCK_BUF_LOCK_MASK;
2136 		break;
2137 
2138 	case SO_RESERVE_MEM:
2139 		v.val = READ_ONCE(sk->sk_reserved_mem);
2140 		break;
2141 
2142 	case SO_TXREHASH:
2143 		if (!sk_is_tcp(sk))
2144 			return -EOPNOTSUPP;
2145 
2146 		/* Paired with WRITE_ONCE() in sk_setsockopt() */
2147 		v.val = READ_ONCE(sk->sk_txrehash);
2148 		break;
2149 
2150 	default:
2151 		/* We implement the SO_SNDLOWAT etc to not be settable
2152 		 * (1003.1g 7).
2153 		 */
2154 		return -ENOPROTOOPT;
2155 	}
2156 
2157 	if (len > lv)
2158 		len = lv;
2159 	if (copy_to_sockptr(optval, &v, len))
2160 		return -EFAULT;
2161 lenout:
2162 	if (copy_to_sockptr(optlen, &len, sizeof(int)))
2163 		return -EFAULT;
2164 	return 0;
2165 }
2166 
2167 /*
2168  * Initialize an sk_lock.
2169  *
2170  * (We also register the sk_lock with the lock validator.)
2171  */
2172 static inline void sock_lock_init(struct sock *sk)
2173 {
2174 	sk_owner_clear(sk);
2175 
2176 	if (sk->sk_kern_sock)
2177 		sock_lock_init_class_and_name(
2178 			sk,
2179 			af_family_kern_slock_key_strings[sk->sk_family],
2180 			af_family_kern_slock_keys + sk->sk_family,
2181 			af_family_kern_key_strings[sk->sk_family],
2182 			af_family_kern_keys + sk->sk_family);
2183 	else
2184 		sock_lock_init_class_and_name(
2185 			sk,
2186 			af_family_slock_key_strings[sk->sk_family],
2187 			af_family_slock_keys + sk->sk_family,
2188 			af_family_key_strings[sk->sk_family],
2189 			af_family_keys + sk->sk_family);
2190 }
2191 
2192 /*
2193  * Copy all fields from osk to nsk but nsk->sk_refcnt must not change yet,
2194  * even temporarily, because of RCU lookups. sk_node should also be left as is.
2195  * We must not copy fields between sk_dontcopy_begin and sk_dontcopy_end
2196  */
2197 static void sock_copy(struct sock *nsk, const struct sock *osk)
2198 {
2199 	const struct proto *prot = READ_ONCE(osk->sk_prot);
2200 #ifdef CONFIG_SECURITY_NETWORK
2201 	void *sptr = nsk->sk_security;
2202 #endif
2203 
2204 	/* If we move sk_tx_queue_mapping out of the private section,
2205 	 * we must check if sk_tx_queue_clear() is called after
2206 	 * sock_copy() in sk_clone_lock().
2207 	 */
2208 	BUILD_BUG_ON(offsetof(struct sock, sk_tx_queue_mapping) <
2209 		     offsetof(struct sock, sk_dontcopy_begin) ||
2210 		     offsetof(struct sock, sk_tx_queue_mapping) >=
2211 		     offsetof(struct sock, sk_dontcopy_end));
2212 
2213 	memcpy(nsk, osk, offsetof(struct sock, sk_dontcopy_begin));
2214 
2215 	unsafe_memcpy(&nsk->sk_dontcopy_end, &osk->sk_dontcopy_end,
2216 		      prot->obj_size - offsetof(struct sock, sk_dontcopy_end),
2217 		      /* alloc is larger than struct, see sk_prot_alloc() */);
2218 
2219 #ifdef CONFIG_SECURITY_NETWORK
2220 	nsk->sk_security = sptr;
2221 	security_sk_clone(osk, nsk);
2222 #endif
2223 }
2224 
2225 static struct sock *sk_prot_alloc(struct proto *prot, gfp_t priority,
2226 		int family)
2227 {
2228 	struct sock *sk;
2229 	struct kmem_cache *slab;
2230 
2231 	slab = prot->slab;
2232 	if (slab != NULL) {
2233 		sk = kmem_cache_alloc(slab, priority & ~__GFP_ZERO);
2234 		if (!sk)
2235 			return sk;
2236 		if (want_init_on_alloc(priority))
2237 			sk_prot_clear_nulls(sk, prot->obj_size);
2238 	} else
2239 		sk = kmalloc(prot->obj_size, priority);
2240 
2241 	if (sk != NULL) {
2242 		if (security_sk_alloc(sk, family, priority))
2243 			goto out_free;
2244 
2245 		if (!try_module_get(prot->owner))
2246 			goto out_free_sec;
2247 	}
2248 
2249 	return sk;
2250 
2251 out_free_sec:
2252 	security_sk_free(sk);
2253 out_free:
2254 	if (slab != NULL)
2255 		kmem_cache_free(slab, sk);
2256 	else
2257 		kfree(sk);
2258 	return NULL;
2259 }
2260 
2261 static void sk_prot_free(struct proto *prot, struct sock *sk)
2262 {
2263 	struct kmem_cache *slab;
2264 	struct module *owner;
2265 
2266 	owner = prot->owner;
2267 	slab = prot->slab;
2268 
2269 	cgroup_sk_free(&sk->sk_cgrp_data);
2270 	mem_cgroup_sk_free(sk);
2271 	security_sk_free(sk);
2272 
2273 	sk_owner_put(sk);
2274 
2275 	if (slab != NULL)
2276 		kmem_cache_free(slab, sk);
2277 	else
2278 		kfree(sk);
2279 	module_put(owner);
2280 }
2281 
2282 /**
2283  *	sk_alloc - All socket objects are allocated here
2284  *	@net: the applicable net namespace
2285  *	@family: protocol family
2286  *	@priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
2287  *	@prot: struct proto associated with this new sock instance
2288  *	@kern: is this to be a kernel socket?
2289  */
2290 struct sock *sk_alloc(struct net *net, int family, gfp_t priority,
2291 		      struct proto *prot, int kern)
2292 {
2293 	struct sock *sk;
2294 
2295 	sk = sk_prot_alloc(prot, priority | __GFP_ZERO, family);
2296 	if (sk) {
2297 		sk->sk_family = family;
2298 		/*
2299 		 * See comment in struct sock definition to understand
2300 		 * why we need sk_prot_creator -acme
2301 		 */
2302 		sk->sk_prot = sk->sk_prot_creator = prot;
2303 		sk->sk_kern_sock = kern;
2304 		sock_lock_init(sk);
2305 		sk->sk_net_refcnt = kern ? 0 : 1;
2306 		if (likely(sk->sk_net_refcnt)) {
2307 			get_net_track(net, &sk->ns_tracker, priority);
2308 			sock_inuse_add(net, 1);
2309 		} else {
2310 			net_passive_inc(net);
2311 			__netns_tracker_alloc(net, &sk->ns_tracker,
2312 					      false, priority);
2313 		}
2314 
2315 		sock_net_set(sk, net);
2316 		refcount_set(&sk->sk_wmem_alloc, 1);
2317 
2318 		mem_cgroup_sk_alloc(sk);
2319 		cgroup_sk_alloc(&sk->sk_cgrp_data);
2320 		sock_update_classid(&sk->sk_cgrp_data);
2321 		sock_update_netprioidx(&sk->sk_cgrp_data);
2322 		sk_tx_queue_clear(sk);
2323 	}
2324 
2325 	return sk;
2326 }
2327 EXPORT_SYMBOL(sk_alloc);
2328 
2329 /* Sockets having SOCK_RCU_FREE will call this function after one RCU
2330  * grace period. This is the case for UDP sockets and TCP listeners.
2331  */
2332 static void __sk_destruct(struct rcu_head *head)
2333 {
2334 	struct sock *sk = container_of(head, struct sock, sk_rcu);
2335 	struct net *net = sock_net(sk);
2336 	struct sk_filter *filter;
2337 
2338 	if (sk->sk_destruct)
2339 		sk->sk_destruct(sk);
2340 
2341 	filter = rcu_dereference_check(sk->sk_filter,
2342 				       refcount_read(&sk->sk_wmem_alloc) == 0);
2343 	if (filter) {
2344 		sk_filter_uncharge(sk, filter);
2345 		RCU_INIT_POINTER(sk->sk_filter, NULL);
2346 	}
2347 
2348 	sock_disable_timestamp(sk, SK_FLAGS_TIMESTAMP);
2349 
2350 #ifdef CONFIG_BPF_SYSCALL
2351 	bpf_sk_storage_free(sk);
2352 #endif
2353 
2354 	if (atomic_read(&sk->sk_omem_alloc))
2355 		pr_debug("%s: optmem leakage (%d bytes) detected\n",
2356 			 __func__, atomic_read(&sk->sk_omem_alloc));
2357 
2358 	if (sk->sk_frag.page) {
2359 		put_page(sk->sk_frag.page);
2360 		sk->sk_frag.page = NULL;
2361 	}
2362 
2363 	/* We do not need to acquire sk->sk_peer_lock, we are the last user. */
2364 	put_cred(sk->sk_peer_cred);
2365 	put_pid(sk->sk_peer_pid);
2366 
2367 	if (likely(sk->sk_net_refcnt)) {
2368 		put_net_track(net, &sk->ns_tracker);
2369 	} else {
2370 		__netns_tracker_free(net, &sk->ns_tracker, false);
2371 		net_passive_dec(net);
2372 	}
2373 	sk_prot_free(sk->sk_prot_creator, sk);
2374 }
2375 
2376 void sk_net_refcnt_upgrade(struct sock *sk)
2377 {
2378 	struct net *net = sock_net(sk);
2379 
2380 	WARN_ON_ONCE(sk->sk_net_refcnt);
2381 	__netns_tracker_free(net, &sk->ns_tracker, false);
2382 	net_passive_dec(net);
2383 	sk->sk_net_refcnt = 1;
2384 	get_net_track(net, &sk->ns_tracker, GFP_KERNEL);
2385 	sock_inuse_add(net, 1);
2386 }
2387 EXPORT_SYMBOL_GPL(sk_net_refcnt_upgrade);
2388 
2389 void sk_destruct(struct sock *sk)
2390 {
2391 	bool use_call_rcu = sock_flag(sk, SOCK_RCU_FREE);
2392 
2393 	if (rcu_access_pointer(sk->sk_reuseport_cb)) {
2394 		reuseport_detach_sock(sk);
2395 		use_call_rcu = true;
2396 	}
2397 
2398 	if (use_call_rcu)
2399 		call_rcu(&sk->sk_rcu, __sk_destruct);
2400 	else
2401 		__sk_destruct(&sk->sk_rcu);
2402 }
2403 
2404 static void __sk_free(struct sock *sk)
2405 {
2406 	if (likely(sk->sk_net_refcnt))
2407 		sock_inuse_add(sock_net(sk), -1);
2408 
2409 	if (unlikely(sk->sk_net_refcnt && sock_diag_has_destroy_listeners(sk)))
2410 		sock_diag_broadcast_destroy(sk);
2411 	else
2412 		sk_destruct(sk);
2413 }
2414 
2415 void sk_free(struct sock *sk)
2416 {
2417 	/*
2418 	 * We subtract one from sk_wmem_alloc and can know if
2419 	 * some packets are still in some tx queue.
2420 	 * If not null, sock_wfree() will call __sk_free(sk) later
2421 	 */
2422 	if (refcount_dec_and_test(&sk->sk_wmem_alloc))
2423 		__sk_free(sk);
2424 }
2425 EXPORT_SYMBOL(sk_free);
2426 
2427 static void sk_init_common(struct sock *sk)
2428 {
2429 	skb_queue_head_init(&sk->sk_receive_queue);
2430 	skb_queue_head_init(&sk->sk_write_queue);
2431 	skb_queue_head_init(&sk->sk_error_queue);
2432 
2433 	rwlock_init(&sk->sk_callback_lock);
2434 	lockdep_set_class_and_name(&sk->sk_receive_queue.lock,
2435 			af_rlock_keys + sk->sk_family,
2436 			af_family_rlock_key_strings[sk->sk_family]);
2437 	lockdep_set_class_and_name(&sk->sk_write_queue.lock,
2438 			af_wlock_keys + sk->sk_family,
2439 			af_family_wlock_key_strings[sk->sk_family]);
2440 	lockdep_set_class_and_name(&sk->sk_error_queue.lock,
2441 			af_elock_keys + sk->sk_family,
2442 			af_family_elock_key_strings[sk->sk_family]);
2443 	if (sk->sk_kern_sock)
2444 		lockdep_set_class_and_name(&sk->sk_callback_lock,
2445 			af_kern_callback_keys + sk->sk_family,
2446 			af_family_kern_clock_key_strings[sk->sk_family]);
2447 	else
2448 		lockdep_set_class_and_name(&sk->sk_callback_lock,
2449 			af_callback_keys + sk->sk_family,
2450 			af_family_clock_key_strings[sk->sk_family]);
2451 }
2452 
2453 /**
2454  *	sk_clone_lock - clone a socket, and lock its clone
2455  *	@sk: the socket to clone
2456  *	@priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
2457  *
2458  *	Caller must unlock socket even in error path (bh_unlock_sock(newsk))
2459  */
2460 struct sock *sk_clone_lock(const struct sock *sk, const gfp_t priority)
2461 {
2462 	struct proto *prot = READ_ONCE(sk->sk_prot);
2463 	struct sk_filter *filter;
2464 	bool is_charged = true;
2465 	struct sock *newsk;
2466 
2467 	newsk = sk_prot_alloc(prot, priority, sk->sk_family);
2468 	if (!newsk)
2469 		goto out;
2470 
2471 	sock_copy(newsk, sk);
2472 
2473 	newsk->sk_prot_creator = prot;
2474 
2475 	/* SANITY */
2476 	if (likely(newsk->sk_net_refcnt)) {
2477 		get_net_track(sock_net(newsk), &newsk->ns_tracker, priority);
2478 		sock_inuse_add(sock_net(newsk), 1);
2479 	} else {
2480 		/* Kernel sockets are not elevating the struct net refcount.
2481 		 * Instead, use a tracker to more easily detect if a layer
2482 		 * is not properly dismantling its kernel sockets at netns
2483 		 * destroy time.
2484 		 */
2485 		net_passive_inc(sock_net(newsk));
2486 		__netns_tracker_alloc(sock_net(newsk), &newsk->ns_tracker,
2487 				      false, priority);
2488 	}
2489 	sk_node_init(&newsk->sk_node);
2490 	sock_lock_init(newsk);
2491 	bh_lock_sock(newsk);
2492 	newsk->sk_backlog.head	= newsk->sk_backlog.tail = NULL;
2493 	newsk->sk_backlog.len = 0;
2494 
2495 	atomic_set(&newsk->sk_rmem_alloc, 0);
2496 
2497 	/* sk_wmem_alloc set to one (see sk_free() and sock_wfree()) */
2498 	refcount_set(&newsk->sk_wmem_alloc, 1);
2499 
2500 	atomic_set(&newsk->sk_omem_alloc, 0);
2501 	sk_init_common(newsk);
2502 
2503 	newsk->sk_dst_cache	= NULL;
2504 	newsk->sk_dst_pending_confirm = 0;
2505 	newsk->sk_wmem_queued	= 0;
2506 	newsk->sk_forward_alloc = 0;
2507 	newsk->sk_reserved_mem  = 0;
2508 	DEBUG_NET_WARN_ON_ONCE(newsk->sk_drop_counters);
2509 	sk_drops_reset(newsk);
2510 	newsk->sk_send_head	= NULL;
2511 	newsk->sk_userlocks	= sk->sk_userlocks & ~SOCK_BINDPORT_LOCK;
2512 	atomic_set(&newsk->sk_zckey, 0);
2513 
2514 	sock_reset_flag(newsk, SOCK_DONE);
2515 
2516 #ifdef CONFIG_MEMCG
2517 	/* sk->sk_memcg will be populated at accept() time */
2518 	newsk->sk_memcg = NULL;
2519 #endif
2520 
2521 	cgroup_sk_clone(&newsk->sk_cgrp_data);
2522 
2523 	rcu_read_lock();
2524 	filter = rcu_dereference(sk->sk_filter);
2525 	if (filter != NULL)
2526 		/* though it's an empty new sock, the charging may fail
2527 		 * if sysctl_optmem_max was changed between creation of
2528 		 * original socket and cloning
2529 		 */
2530 		is_charged = sk_filter_charge(newsk, filter);
2531 	RCU_INIT_POINTER(newsk->sk_filter, filter);
2532 	rcu_read_unlock();
2533 
2534 	if (unlikely(!is_charged || xfrm_sk_clone_policy(newsk, sk))) {
2535 		/* We need to make sure that we don't uncharge the new
2536 		 * socket if we couldn't charge it in the first place
2537 		 * as otherwise we uncharge the parent's filter.
2538 		 */
2539 		if (!is_charged)
2540 			RCU_INIT_POINTER(newsk->sk_filter, NULL);
2541 
2542 		goto free;
2543 	}
2544 
2545 	RCU_INIT_POINTER(newsk->sk_reuseport_cb, NULL);
2546 
2547 	if (bpf_sk_storage_clone(sk, newsk))
2548 		goto free;
2549 
2550 	/* Clear sk_user_data if parent had the pointer tagged
2551 	 * as not suitable for copying when cloning.
2552 	 */
2553 	if (sk_user_data_is_nocopy(newsk))
2554 		newsk->sk_user_data = NULL;
2555 
2556 	newsk->sk_err	   = 0;
2557 	newsk->sk_err_soft = 0;
2558 	newsk->sk_priority = 0;
2559 	newsk->sk_incoming_cpu = raw_smp_processor_id();
2560 
2561 	/* Before updating sk_refcnt, we must commit prior changes to memory
2562 	 * (Documentation/RCU/rculist_nulls.rst for details)
2563 	 */
2564 	smp_wmb();
2565 	refcount_set(&newsk->sk_refcnt, 2);
2566 
2567 	sk_set_socket(newsk, NULL);
2568 	sk_tx_queue_clear(newsk);
2569 	RCU_INIT_POINTER(newsk->sk_wq, NULL);
2570 
2571 	if (newsk->sk_prot->sockets_allocated)
2572 		sk_sockets_allocated_inc(newsk);
2573 
2574 	if (sock_needs_netstamp(sk) && newsk->sk_flags & SK_FLAGS_TIMESTAMP)
2575 		net_enable_timestamp();
2576 out:
2577 	return newsk;
2578 free:
2579 	/* It is still raw copy of parent, so invalidate
2580 	 * destructor and make plain sk_free()
2581 	 */
2582 	newsk->sk_destruct = NULL;
2583 	bh_unlock_sock(newsk);
2584 	sk_free(newsk);
2585 	newsk = NULL;
2586 	goto out;
2587 }
2588 EXPORT_SYMBOL_GPL(sk_clone_lock);
2589 
2590 static u32 sk_dst_gso_max_size(struct sock *sk, const struct net_device *dev)
2591 {
2592 	bool is_ipv6 = false;
2593 	u32 max_size;
2594 
2595 #if IS_ENABLED(CONFIG_IPV6)
2596 	is_ipv6 = (sk->sk_family == AF_INET6 &&
2597 		   !ipv6_addr_v4mapped(&sk->sk_v6_rcv_saddr));
2598 #endif
2599 	/* pairs with the WRITE_ONCE() in netif_set_gso(_ipv4)_max_size() */
2600 	max_size = is_ipv6 ? READ_ONCE(dev->gso_max_size) :
2601 			READ_ONCE(dev->gso_ipv4_max_size);
2602 	if (max_size > GSO_LEGACY_MAX_SIZE && !sk_is_tcp(sk))
2603 		max_size = GSO_LEGACY_MAX_SIZE;
2604 
2605 	return max_size - (MAX_TCP_HEADER + 1);
2606 }
2607 
2608 void sk_setup_caps(struct sock *sk, struct dst_entry *dst)
2609 {
2610 	const struct net_device *dev;
2611 	u32 max_segs = 1;
2612 
2613 	rcu_read_lock();
2614 	dev = dst_dev_rcu(dst);
2615 	sk->sk_route_caps = dev->features;
2616 	if (sk_is_tcp(sk)) {
2617 		struct inet_connection_sock *icsk = inet_csk(sk);
2618 
2619 		sk->sk_route_caps |= NETIF_F_GSO;
2620 		icsk->icsk_ack.dst_quick_ack = dst_metric(dst, RTAX_QUICKACK);
2621 	}
2622 	if (sk->sk_route_caps & NETIF_F_GSO)
2623 		sk->sk_route_caps |= NETIF_F_GSO_SOFTWARE;
2624 	if (unlikely(sk->sk_gso_disabled))
2625 		sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
2626 	if (sk_can_gso(sk)) {
2627 		if (dst->header_len && !xfrm_dst_offload_ok(dst)) {
2628 			sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
2629 		} else {
2630 			sk->sk_route_caps |= NETIF_F_SG | NETIF_F_HW_CSUM;
2631 			sk->sk_gso_max_size = sk_dst_gso_max_size(sk, dev);
2632 			/* pairs with the WRITE_ONCE() in netif_set_gso_max_segs() */
2633 			max_segs = max_t(u32, READ_ONCE(dev->gso_max_segs), 1);
2634 		}
2635 	}
2636 	sk->sk_gso_max_segs = max_segs;
2637 	sk_dst_set(sk, dst);
2638 	rcu_read_unlock();
2639 }
2640 EXPORT_SYMBOL_GPL(sk_setup_caps);
2641 
2642 /*
2643  *	Simple resource managers for sockets.
2644  */
2645 
2646 
2647 /*
2648  * Write buffer destructor automatically called from kfree_skb.
2649  */
2650 void sock_wfree(struct sk_buff *skb)
2651 {
2652 	struct sock *sk = skb->sk;
2653 	unsigned int len = skb->truesize;
2654 	bool free;
2655 
2656 	if (!sock_flag(sk, SOCK_USE_WRITE_QUEUE)) {
2657 		if (sock_flag(sk, SOCK_RCU_FREE) &&
2658 		    sk->sk_write_space == sock_def_write_space) {
2659 			rcu_read_lock();
2660 			free = refcount_sub_and_test(len, &sk->sk_wmem_alloc);
2661 			sock_def_write_space_wfree(sk);
2662 			rcu_read_unlock();
2663 			if (unlikely(free))
2664 				__sk_free(sk);
2665 			return;
2666 		}
2667 
2668 		/*
2669 		 * Keep a reference on sk_wmem_alloc, this will be released
2670 		 * after sk_write_space() call
2671 		 */
2672 		WARN_ON(refcount_sub_and_test(len - 1, &sk->sk_wmem_alloc));
2673 		sk->sk_write_space(sk);
2674 		len = 1;
2675 	}
2676 	/*
2677 	 * if sk_wmem_alloc reaches 0, we must finish what sk_free()
2678 	 * could not do because of in-flight packets
2679 	 */
2680 	if (refcount_sub_and_test(len, &sk->sk_wmem_alloc))
2681 		__sk_free(sk);
2682 }
2683 EXPORT_SYMBOL(sock_wfree);
2684 
2685 /* This variant of sock_wfree() is used by TCP,
2686  * since it sets SOCK_USE_WRITE_QUEUE.
2687  */
2688 void __sock_wfree(struct sk_buff *skb)
2689 {
2690 	struct sock *sk = skb->sk;
2691 
2692 	if (refcount_sub_and_test(skb->truesize, &sk->sk_wmem_alloc))
2693 		__sk_free(sk);
2694 }
2695 
2696 void skb_set_owner_w(struct sk_buff *skb, struct sock *sk)
2697 {
2698 	skb_orphan(skb);
2699 #ifdef CONFIG_INET
2700 	if (unlikely(!sk_fullsock(sk)))
2701 		return skb_set_owner_edemux(skb, sk);
2702 #endif
2703 	skb->sk = sk;
2704 	skb->destructor = sock_wfree;
2705 	skb_set_hash_from_sk(skb, sk);
2706 	/*
2707 	 * We used to take a refcount on sk, but following operation
2708 	 * is enough to guarantee sk_free() won't free this sock until
2709 	 * all in-flight packets are completed
2710 	 */
2711 	refcount_add(skb->truesize, &sk->sk_wmem_alloc);
2712 }
2713 EXPORT_SYMBOL(skb_set_owner_w);
2714 
2715 static bool can_skb_orphan_partial(const struct sk_buff *skb)
2716 {
2717 	/* Drivers depend on in-order delivery for crypto offload,
2718 	 * partial orphan breaks out-of-order-OK logic.
2719 	 */
2720 	if (skb_is_decrypted(skb))
2721 		return false;
2722 
2723 	return (skb->destructor == sock_wfree ||
2724 		(IS_ENABLED(CONFIG_INET) && skb->destructor == tcp_wfree));
2725 }
2726 
2727 /* This helper is used by netem, as it can hold packets in its
2728  * delay queue. We want to allow the owner socket to send more
2729  * packets, as if they were already TX completed by a typical driver.
2730  * But we also want to keep skb->sk set because some packet schedulers
2731  * rely on it (sch_fq for example).
2732  */
2733 void skb_orphan_partial(struct sk_buff *skb)
2734 {
2735 	if (skb_is_tcp_pure_ack(skb))
2736 		return;
2737 
2738 	if (can_skb_orphan_partial(skb) && skb_set_owner_sk_safe(skb, skb->sk))
2739 		return;
2740 
2741 	skb_orphan(skb);
2742 }
2743 EXPORT_SYMBOL(skb_orphan_partial);
2744 
2745 /*
2746  * Read buffer destructor automatically called from kfree_skb.
2747  */
2748 void sock_rfree(struct sk_buff *skb)
2749 {
2750 	struct sock *sk = skb->sk;
2751 	unsigned int len = skb->truesize;
2752 
2753 	atomic_sub(len, &sk->sk_rmem_alloc);
2754 	sk_mem_uncharge(sk, len);
2755 }
2756 EXPORT_SYMBOL(sock_rfree);
2757 
2758 /*
2759  * Buffer destructor for skbs that are not used directly in read or write
2760  * path, e.g. for error handler skbs. Automatically called from kfree_skb.
2761  */
2762 void sock_efree(struct sk_buff *skb)
2763 {
2764 	sock_put(skb->sk);
2765 }
2766 EXPORT_SYMBOL(sock_efree);
2767 
2768 /* Buffer destructor for prefetch/receive path where reference count may
2769  * not be held, e.g. for listen sockets.
2770  */
2771 #ifdef CONFIG_INET
2772 void sock_pfree(struct sk_buff *skb)
2773 {
2774 	struct sock *sk = skb->sk;
2775 
2776 	if (!sk_is_refcounted(sk))
2777 		return;
2778 
2779 	if (sk->sk_state == TCP_NEW_SYN_RECV && inet_reqsk(sk)->syncookie) {
2780 		inet_reqsk(sk)->rsk_listener = NULL;
2781 		reqsk_free(inet_reqsk(sk));
2782 		return;
2783 	}
2784 
2785 	sock_gen_put(sk);
2786 }
2787 EXPORT_SYMBOL(sock_pfree);
2788 #endif /* CONFIG_INET */
2789 
2790 /*
2791  * Allocate a skb from the socket's send buffer.
2792  */
2793 struct sk_buff *sock_wmalloc(struct sock *sk, unsigned long size, int force,
2794 			     gfp_t priority)
2795 {
2796 	if (force ||
2797 	    refcount_read(&sk->sk_wmem_alloc) < READ_ONCE(sk->sk_sndbuf)) {
2798 		struct sk_buff *skb = alloc_skb(size, priority);
2799 
2800 		if (skb) {
2801 			skb_set_owner_w(skb, sk);
2802 			return skb;
2803 		}
2804 	}
2805 	return NULL;
2806 }
2807 EXPORT_SYMBOL(sock_wmalloc);
2808 
2809 static void sock_ofree(struct sk_buff *skb)
2810 {
2811 	struct sock *sk = skb->sk;
2812 
2813 	atomic_sub(skb->truesize, &sk->sk_omem_alloc);
2814 }
2815 
2816 struct sk_buff *sock_omalloc(struct sock *sk, unsigned long size,
2817 			     gfp_t priority)
2818 {
2819 	struct sk_buff *skb;
2820 
2821 	/* small safe race: SKB_TRUESIZE may differ from final skb->truesize */
2822 	if (atomic_read(&sk->sk_omem_alloc) + SKB_TRUESIZE(size) >
2823 	    READ_ONCE(sock_net(sk)->core.sysctl_optmem_max))
2824 		return NULL;
2825 
2826 	skb = alloc_skb(size, priority);
2827 	if (!skb)
2828 		return NULL;
2829 
2830 	atomic_add(skb->truesize, &sk->sk_omem_alloc);
2831 	skb->sk = sk;
2832 	skb->destructor = sock_ofree;
2833 	return skb;
2834 }
2835 
2836 /*
2837  * Allocate a memory block from the socket's option memory buffer.
2838  */
2839 void *sock_kmalloc(struct sock *sk, int size, gfp_t priority)
2840 {
2841 	int optmem_max = READ_ONCE(sock_net(sk)->core.sysctl_optmem_max);
2842 
2843 	if ((unsigned int)size <= optmem_max &&
2844 	    atomic_read(&sk->sk_omem_alloc) + size < optmem_max) {
2845 		void *mem;
2846 		/* First do the add, to avoid the race if kmalloc
2847 		 * might sleep.
2848 		 */
2849 		atomic_add(size, &sk->sk_omem_alloc);
2850 		mem = kmalloc(size, priority);
2851 		if (mem)
2852 			return mem;
2853 		atomic_sub(size, &sk->sk_omem_alloc);
2854 	}
2855 	return NULL;
2856 }
2857 EXPORT_SYMBOL(sock_kmalloc);
2858 
2859 /*
2860  * Duplicate the input "src" memory block using the socket's
2861  * option memory buffer.
2862  */
2863 void *sock_kmemdup(struct sock *sk, const void *src,
2864 		   int size, gfp_t priority)
2865 {
2866 	void *mem;
2867 
2868 	mem = sock_kmalloc(sk, size, priority);
2869 	if (mem)
2870 		memcpy(mem, src, size);
2871 	return mem;
2872 }
2873 EXPORT_SYMBOL(sock_kmemdup);
2874 
2875 /* Free an option memory block. Note, we actually want the inline
2876  * here as this allows gcc to detect the nullify and fold away the
2877  * condition entirely.
2878  */
2879 static inline void __sock_kfree_s(struct sock *sk, void *mem, int size,
2880 				  const bool nullify)
2881 {
2882 	if (WARN_ON_ONCE(!mem))
2883 		return;
2884 	if (nullify)
2885 		kfree_sensitive(mem);
2886 	else
2887 		kfree(mem);
2888 	atomic_sub(size, &sk->sk_omem_alloc);
2889 }
2890 
2891 void sock_kfree_s(struct sock *sk, void *mem, int size)
2892 {
2893 	__sock_kfree_s(sk, mem, size, false);
2894 }
2895 EXPORT_SYMBOL(sock_kfree_s);
2896 
2897 void sock_kzfree_s(struct sock *sk, void *mem, int size)
2898 {
2899 	__sock_kfree_s(sk, mem, size, true);
2900 }
2901 EXPORT_SYMBOL(sock_kzfree_s);
2902 
2903 /* It is almost wait_for_tcp_memory minus release_sock/lock_sock.
2904    I think, these locks should be removed for datagram sockets.
2905  */
2906 static long sock_wait_for_wmem(struct sock *sk, long timeo)
2907 {
2908 	DEFINE_WAIT(wait);
2909 
2910 	sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
2911 	for (;;) {
2912 		if (!timeo)
2913 			break;
2914 		if (signal_pending(current))
2915 			break;
2916 		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
2917 		prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
2918 		if (refcount_read(&sk->sk_wmem_alloc) < READ_ONCE(sk->sk_sndbuf))
2919 			break;
2920 		if (READ_ONCE(sk->sk_shutdown) & SEND_SHUTDOWN)
2921 			break;
2922 		if (READ_ONCE(sk->sk_err))
2923 			break;
2924 		timeo = schedule_timeout(timeo);
2925 	}
2926 	finish_wait(sk_sleep(sk), &wait);
2927 	return timeo;
2928 }
2929 
2930 
2931 /*
2932  *	Generic send/receive buffer handlers
2933  */
2934 
2935 struct sk_buff *sock_alloc_send_pskb(struct sock *sk, unsigned long header_len,
2936 				     unsigned long data_len, int noblock,
2937 				     int *errcode, int max_page_order)
2938 {
2939 	struct sk_buff *skb;
2940 	long timeo;
2941 	int err;
2942 
2943 	timeo = sock_sndtimeo(sk, noblock);
2944 	for (;;) {
2945 		err = sock_error(sk);
2946 		if (err != 0)
2947 			goto failure;
2948 
2949 		err = -EPIPE;
2950 		if (READ_ONCE(sk->sk_shutdown) & SEND_SHUTDOWN)
2951 			goto failure;
2952 
2953 		if (sk_wmem_alloc_get(sk) < READ_ONCE(sk->sk_sndbuf))
2954 			break;
2955 
2956 		sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
2957 		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
2958 		err = -EAGAIN;
2959 		if (!timeo)
2960 			goto failure;
2961 		if (signal_pending(current))
2962 			goto interrupted;
2963 		timeo = sock_wait_for_wmem(sk, timeo);
2964 	}
2965 	skb = alloc_skb_with_frags(header_len, data_len, max_page_order,
2966 				   errcode, sk->sk_allocation);
2967 	if (skb)
2968 		skb_set_owner_w(skb, sk);
2969 	return skb;
2970 
2971 interrupted:
2972 	err = sock_intr_errno(timeo);
2973 failure:
2974 	*errcode = err;
2975 	return NULL;
2976 }
2977 EXPORT_SYMBOL(sock_alloc_send_pskb);
2978 
2979 int __sock_cmsg_send(struct sock *sk, struct cmsghdr *cmsg,
2980 		     struct sockcm_cookie *sockc)
2981 {
2982 	u32 tsflags;
2983 
2984 	BUILD_BUG_ON(SOF_TIMESTAMPING_LAST == (1 << 31));
2985 
2986 	switch (cmsg->cmsg_type) {
2987 	case SO_MARK:
2988 		if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_RAW) &&
2989 		    !ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
2990 			return -EPERM;
2991 		if (cmsg->cmsg_len != CMSG_LEN(sizeof(u32)))
2992 			return -EINVAL;
2993 		sockc->mark = *(u32 *)CMSG_DATA(cmsg);
2994 		break;
2995 	case SO_TIMESTAMPING_OLD:
2996 	case SO_TIMESTAMPING_NEW:
2997 		if (cmsg->cmsg_len != CMSG_LEN(sizeof(u32)))
2998 			return -EINVAL;
2999 
3000 		tsflags = *(u32 *)CMSG_DATA(cmsg);
3001 		if (tsflags & ~SOF_TIMESTAMPING_TX_RECORD_MASK)
3002 			return -EINVAL;
3003 
3004 		sockc->tsflags &= ~SOF_TIMESTAMPING_TX_RECORD_MASK;
3005 		sockc->tsflags |= tsflags;
3006 		break;
3007 	case SCM_TXTIME:
3008 		if (!sock_flag(sk, SOCK_TXTIME))
3009 			return -EINVAL;
3010 		if (cmsg->cmsg_len != CMSG_LEN(sizeof(u64)))
3011 			return -EINVAL;
3012 		sockc->transmit_time = get_unaligned((u64 *)CMSG_DATA(cmsg));
3013 		break;
3014 	case SCM_TS_OPT_ID:
3015 		if (sk_is_tcp(sk))
3016 			return -EINVAL;
3017 		tsflags = READ_ONCE(sk->sk_tsflags);
3018 		if (!(tsflags & SOF_TIMESTAMPING_OPT_ID))
3019 			return -EINVAL;
3020 		if (cmsg->cmsg_len != CMSG_LEN(sizeof(u32)))
3021 			return -EINVAL;
3022 		sockc->ts_opt_id = *(u32 *)CMSG_DATA(cmsg);
3023 		sockc->tsflags |= SOCKCM_FLAG_TS_OPT_ID;
3024 		break;
3025 	/* SCM_RIGHTS and SCM_CREDENTIALS are semantically in SOL_UNIX. */
3026 	case SCM_RIGHTS:
3027 	case SCM_CREDENTIALS:
3028 		break;
3029 	case SO_PRIORITY:
3030 		if (cmsg->cmsg_len != CMSG_LEN(sizeof(u32)))
3031 			return -EINVAL;
3032 		if (!sk_set_prio_allowed(sk, *(u32 *)CMSG_DATA(cmsg)))
3033 			return -EPERM;
3034 		sockc->priority = *(u32 *)CMSG_DATA(cmsg);
3035 		break;
3036 	case SCM_DEVMEM_DMABUF:
3037 		if (cmsg->cmsg_len != CMSG_LEN(sizeof(u32)))
3038 			return -EINVAL;
3039 		sockc->dmabuf_id = *(u32 *)CMSG_DATA(cmsg);
3040 		break;
3041 	default:
3042 		return -EINVAL;
3043 	}
3044 	return 0;
3045 }
3046 EXPORT_SYMBOL(__sock_cmsg_send);
3047 
3048 int sock_cmsg_send(struct sock *sk, struct msghdr *msg,
3049 		   struct sockcm_cookie *sockc)
3050 {
3051 	struct cmsghdr *cmsg;
3052 	int ret;
3053 
3054 	for_each_cmsghdr(cmsg, msg) {
3055 		if (!CMSG_OK(msg, cmsg))
3056 			return -EINVAL;
3057 		if (cmsg->cmsg_level != SOL_SOCKET)
3058 			continue;
3059 		ret = __sock_cmsg_send(sk, cmsg, sockc);
3060 		if (ret)
3061 			return ret;
3062 	}
3063 	return 0;
3064 }
3065 EXPORT_SYMBOL(sock_cmsg_send);
3066 
3067 static void sk_enter_memory_pressure(struct sock *sk)
3068 {
3069 	if (!sk->sk_prot->enter_memory_pressure)
3070 		return;
3071 
3072 	sk->sk_prot->enter_memory_pressure(sk);
3073 }
3074 
3075 static void sk_leave_memory_pressure(struct sock *sk)
3076 {
3077 	if (sk->sk_prot->leave_memory_pressure) {
3078 		INDIRECT_CALL_INET_1(sk->sk_prot->leave_memory_pressure,
3079 				     tcp_leave_memory_pressure, sk);
3080 	} else {
3081 		unsigned long *memory_pressure = sk->sk_prot->memory_pressure;
3082 
3083 		if (memory_pressure && READ_ONCE(*memory_pressure))
3084 			WRITE_ONCE(*memory_pressure, 0);
3085 	}
3086 }
3087 
3088 DEFINE_STATIC_KEY_FALSE(net_high_order_alloc_disable_key);
3089 
3090 /**
3091  * skb_page_frag_refill - check that a page_frag contains enough room
3092  * @sz: minimum size of the fragment we want to get
3093  * @pfrag: pointer to page_frag
3094  * @gfp: priority for memory allocation
3095  *
3096  * Note: While this allocator tries to use high order pages, there is
3097  * no guarantee that allocations succeed. Therefore, @sz MUST be
3098  * less or equal than PAGE_SIZE.
3099  */
3100 bool skb_page_frag_refill(unsigned int sz, struct page_frag *pfrag, gfp_t gfp)
3101 {
3102 	if (pfrag->page) {
3103 		if (page_ref_count(pfrag->page) == 1) {
3104 			pfrag->offset = 0;
3105 			return true;
3106 		}
3107 		if (pfrag->offset + sz <= pfrag->size)
3108 			return true;
3109 		put_page(pfrag->page);
3110 	}
3111 
3112 	pfrag->offset = 0;
3113 	if (SKB_FRAG_PAGE_ORDER &&
3114 	    !static_branch_unlikely(&net_high_order_alloc_disable_key)) {
3115 		/* Avoid direct reclaim but allow kswapd to wake */
3116 		pfrag->page = alloc_pages((gfp & ~__GFP_DIRECT_RECLAIM) |
3117 					  __GFP_COMP | __GFP_NOWARN |
3118 					  __GFP_NORETRY,
3119 					  SKB_FRAG_PAGE_ORDER);
3120 		if (likely(pfrag->page)) {
3121 			pfrag->size = PAGE_SIZE << SKB_FRAG_PAGE_ORDER;
3122 			return true;
3123 		}
3124 	}
3125 	pfrag->page = alloc_page(gfp);
3126 	if (likely(pfrag->page)) {
3127 		pfrag->size = PAGE_SIZE;
3128 		return true;
3129 	}
3130 	return false;
3131 }
3132 EXPORT_SYMBOL(skb_page_frag_refill);
3133 
3134 bool sk_page_frag_refill(struct sock *sk, struct page_frag *pfrag)
3135 {
3136 	if (likely(skb_page_frag_refill(32U, pfrag, sk->sk_allocation)))
3137 		return true;
3138 
3139 	sk_enter_memory_pressure(sk);
3140 	sk_stream_moderate_sndbuf(sk);
3141 	return false;
3142 }
3143 EXPORT_SYMBOL(sk_page_frag_refill);
3144 
3145 void __lock_sock(struct sock *sk)
3146 	__releases(&sk->sk_lock.slock)
3147 	__acquires(&sk->sk_lock.slock)
3148 {
3149 	DEFINE_WAIT(wait);
3150 
3151 	for (;;) {
3152 		prepare_to_wait_exclusive(&sk->sk_lock.wq, &wait,
3153 					TASK_UNINTERRUPTIBLE);
3154 		spin_unlock_bh(&sk->sk_lock.slock);
3155 		schedule();
3156 		spin_lock_bh(&sk->sk_lock.slock);
3157 		if (!sock_owned_by_user(sk))
3158 			break;
3159 	}
3160 	finish_wait(&sk->sk_lock.wq, &wait);
3161 }
3162 
3163 void __release_sock(struct sock *sk)
3164 	__releases(&sk->sk_lock.slock)
3165 	__acquires(&sk->sk_lock.slock)
3166 {
3167 	struct sk_buff *skb, *next;
3168 	int nb = 0;
3169 
3170 	while ((skb = sk->sk_backlog.head) != NULL) {
3171 		sk->sk_backlog.head = sk->sk_backlog.tail = NULL;
3172 
3173 		spin_unlock_bh(&sk->sk_lock.slock);
3174 
3175 		while (1) {
3176 			next = skb->next;
3177 			prefetch(next);
3178 			DEBUG_NET_WARN_ON_ONCE(skb_dst_is_noref(skb));
3179 			skb_mark_not_on_list(skb);
3180 			sk_backlog_rcv(sk, skb);
3181 
3182 			skb = next;
3183 			if (!skb)
3184 				break;
3185 
3186 			if (!(++nb & 15))
3187 				cond_resched();
3188 		}
3189 
3190 		spin_lock_bh(&sk->sk_lock.slock);
3191 	}
3192 
3193 	/*
3194 	 * Doing the zeroing here guarantee we can not loop forever
3195 	 * while a wild producer attempts to flood us.
3196 	 */
3197 	sk->sk_backlog.len = 0;
3198 }
3199 
3200 void __sk_flush_backlog(struct sock *sk)
3201 {
3202 	spin_lock_bh(&sk->sk_lock.slock);
3203 	__release_sock(sk);
3204 
3205 	if (sk->sk_prot->release_cb)
3206 		INDIRECT_CALL_INET_1(sk->sk_prot->release_cb,
3207 				     tcp_release_cb, sk);
3208 
3209 	spin_unlock_bh(&sk->sk_lock.slock);
3210 }
3211 EXPORT_SYMBOL_GPL(__sk_flush_backlog);
3212 
3213 /**
3214  * sk_wait_data - wait for data to arrive at sk_receive_queue
3215  * @sk:    sock to wait on
3216  * @timeo: for how long
3217  * @skb:   last skb seen on sk_receive_queue
3218  *
3219  * Now socket state including sk->sk_err is changed only under lock,
3220  * hence we may omit checks after joining wait queue.
3221  * We check receive queue before schedule() only as optimization;
3222  * it is very likely that release_sock() added new data.
3223  */
3224 int sk_wait_data(struct sock *sk, long *timeo, const struct sk_buff *skb)
3225 {
3226 	DEFINE_WAIT_FUNC(wait, woken_wake_function);
3227 	int rc;
3228 
3229 	add_wait_queue(sk_sleep(sk), &wait);
3230 	sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
3231 	rc = sk_wait_event(sk, timeo, skb_peek_tail(&sk->sk_receive_queue) != skb, &wait);
3232 	sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
3233 	remove_wait_queue(sk_sleep(sk), &wait);
3234 	return rc;
3235 }
3236 EXPORT_SYMBOL(sk_wait_data);
3237 
3238 /**
3239  *	__sk_mem_raise_allocated - increase memory_allocated
3240  *	@sk: socket
3241  *	@size: memory size to allocate
3242  *	@amt: pages to allocate
3243  *	@kind: allocation type
3244  *
3245  *	Similar to __sk_mem_schedule(), but does not update sk_forward_alloc.
3246  *
3247  *	Unlike the globally shared limits among the sockets under same protocol,
3248  *	consuming the budget of a memcg won't have direct effect on other ones.
3249  *	So be optimistic about memcg's tolerance, and leave the callers to decide
3250  *	whether or not to raise allocated through sk_under_memory_pressure() or
3251  *	its variants.
3252  */
3253 int __sk_mem_raise_allocated(struct sock *sk, int size, int amt, int kind)
3254 {
3255 	bool memcg_enabled = false, charged = false;
3256 	struct proto *prot = sk->sk_prot;
3257 	long allocated;
3258 
3259 	sk_memory_allocated_add(sk, amt);
3260 	allocated = sk_memory_allocated(sk);
3261 
3262 	if (mem_cgroup_sk_enabled(sk)) {
3263 		memcg_enabled = true;
3264 		charged = mem_cgroup_sk_charge(sk, amt, gfp_memcg_charge());
3265 		if (!charged)
3266 			goto suppress_allocation;
3267 	}
3268 
3269 	/* Under limit. */
3270 	if (allocated <= sk_prot_mem_limits(sk, 0)) {
3271 		sk_leave_memory_pressure(sk);
3272 		return 1;
3273 	}
3274 
3275 	/* Under pressure. */
3276 	if (allocated > sk_prot_mem_limits(sk, 1))
3277 		sk_enter_memory_pressure(sk);
3278 
3279 	/* Over hard limit. */
3280 	if (allocated > sk_prot_mem_limits(sk, 2))
3281 		goto suppress_allocation;
3282 
3283 	/* Guarantee minimum buffer size under pressure (either global
3284 	 * or memcg) to make sure features described in RFC 7323 (TCP
3285 	 * Extensions for High Performance) work properly.
3286 	 *
3287 	 * This rule does NOT stand when exceeds global or memcg's hard
3288 	 * limit, or else a DoS attack can be taken place by spawning
3289 	 * lots of sockets whose usage are under minimum buffer size.
3290 	 */
3291 	if (kind == SK_MEM_RECV) {
3292 		if (atomic_read(&sk->sk_rmem_alloc) < sk_get_rmem0(sk, prot))
3293 			return 1;
3294 
3295 	} else { /* SK_MEM_SEND */
3296 		int wmem0 = sk_get_wmem0(sk, prot);
3297 
3298 		if (sk->sk_type == SOCK_STREAM) {
3299 			if (sk->sk_wmem_queued < wmem0)
3300 				return 1;
3301 		} else if (refcount_read(&sk->sk_wmem_alloc) < wmem0) {
3302 				return 1;
3303 		}
3304 	}
3305 
3306 	if (sk_has_memory_pressure(sk)) {
3307 		u64 alloc;
3308 
3309 		/* The following 'average' heuristic is within the
3310 		 * scope of global accounting, so it only makes
3311 		 * sense for global memory pressure.
3312 		 */
3313 		if (!sk_under_global_memory_pressure(sk))
3314 			return 1;
3315 
3316 		/* Try to be fair among all the sockets under global
3317 		 * pressure by allowing the ones that below average
3318 		 * usage to raise.
3319 		 */
3320 		alloc = sk_sockets_allocated_read_positive(sk);
3321 		if (sk_prot_mem_limits(sk, 2) > alloc *
3322 		    sk_mem_pages(sk->sk_wmem_queued +
3323 				 atomic_read(&sk->sk_rmem_alloc) +
3324 				 sk->sk_forward_alloc))
3325 			return 1;
3326 	}
3327 
3328 suppress_allocation:
3329 
3330 	if (kind == SK_MEM_SEND && sk->sk_type == SOCK_STREAM) {
3331 		sk_stream_moderate_sndbuf(sk);
3332 
3333 		/* Fail only if socket is _under_ its sndbuf.
3334 		 * In this case we cannot block, so that we have to fail.
3335 		 */
3336 		if (sk->sk_wmem_queued + size >= sk->sk_sndbuf) {
3337 			/* Force charge with __GFP_NOFAIL */
3338 			if (memcg_enabled && !charged)
3339 				mem_cgroup_sk_charge(sk, amt,
3340 						     gfp_memcg_charge() | __GFP_NOFAIL);
3341 			return 1;
3342 		}
3343 	}
3344 
3345 	trace_sock_exceed_buf_limit(sk, prot, allocated, kind);
3346 
3347 	sk_memory_allocated_sub(sk, amt);
3348 
3349 	if (charged)
3350 		mem_cgroup_sk_uncharge(sk, amt);
3351 
3352 	return 0;
3353 }
3354 
3355 /**
3356  *	__sk_mem_schedule - increase sk_forward_alloc and memory_allocated
3357  *	@sk: socket
3358  *	@size: memory size to allocate
3359  *	@kind: allocation type
3360  *
3361  *	If kind is SK_MEM_SEND, it means wmem allocation. Otherwise it means
3362  *	rmem allocation. This function assumes that protocols which have
3363  *	memory_pressure use sk_wmem_queued as write buffer accounting.
3364  */
3365 int __sk_mem_schedule(struct sock *sk, int size, int kind)
3366 {
3367 	int ret, amt = sk_mem_pages(size);
3368 
3369 	sk_forward_alloc_add(sk, amt << PAGE_SHIFT);
3370 	ret = __sk_mem_raise_allocated(sk, size, amt, kind);
3371 	if (!ret)
3372 		sk_forward_alloc_add(sk, -(amt << PAGE_SHIFT));
3373 	return ret;
3374 }
3375 EXPORT_SYMBOL(__sk_mem_schedule);
3376 
3377 /**
3378  *	__sk_mem_reduce_allocated - reclaim memory_allocated
3379  *	@sk: socket
3380  *	@amount: number of quanta
3381  *
3382  *	Similar to __sk_mem_reclaim(), but does not update sk_forward_alloc
3383  */
3384 void __sk_mem_reduce_allocated(struct sock *sk, int amount)
3385 {
3386 	sk_memory_allocated_sub(sk, amount);
3387 
3388 	if (mem_cgroup_sk_enabled(sk))
3389 		mem_cgroup_sk_uncharge(sk, amount);
3390 
3391 	if (sk_under_global_memory_pressure(sk) &&
3392 	    (sk_memory_allocated(sk) < sk_prot_mem_limits(sk, 0)))
3393 		sk_leave_memory_pressure(sk);
3394 }
3395 
3396 /**
3397  *	__sk_mem_reclaim - reclaim sk_forward_alloc and memory_allocated
3398  *	@sk: socket
3399  *	@amount: number of bytes (rounded down to a PAGE_SIZE multiple)
3400  */
3401 void __sk_mem_reclaim(struct sock *sk, int amount)
3402 {
3403 	amount >>= PAGE_SHIFT;
3404 	sk_forward_alloc_add(sk, -(amount << PAGE_SHIFT));
3405 	__sk_mem_reduce_allocated(sk, amount);
3406 }
3407 EXPORT_SYMBOL(__sk_mem_reclaim);
3408 
3409 int sk_set_peek_off(struct sock *sk, int val)
3410 {
3411 	WRITE_ONCE(sk->sk_peek_off, val);
3412 	return 0;
3413 }
3414 EXPORT_SYMBOL_GPL(sk_set_peek_off);
3415 
3416 /*
3417  * Set of default routines for initialising struct proto_ops when
3418  * the protocol does not support a particular function. In certain
3419  * cases where it makes no sense for a protocol to have a "do nothing"
3420  * function, some default processing is provided.
3421  */
3422 
3423 int sock_no_bind(struct socket *sock, struct sockaddr *saddr, int len)
3424 {
3425 	return -EOPNOTSUPP;
3426 }
3427 EXPORT_SYMBOL(sock_no_bind);
3428 
3429 int sock_no_connect(struct socket *sock, struct sockaddr *saddr,
3430 		    int len, int flags)
3431 {
3432 	return -EOPNOTSUPP;
3433 }
3434 EXPORT_SYMBOL(sock_no_connect);
3435 
3436 int sock_no_socketpair(struct socket *sock1, struct socket *sock2)
3437 {
3438 	return -EOPNOTSUPP;
3439 }
3440 EXPORT_SYMBOL(sock_no_socketpair);
3441 
3442 int sock_no_accept(struct socket *sock, struct socket *newsock,
3443 		   struct proto_accept_arg *arg)
3444 {
3445 	return -EOPNOTSUPP;
3446 }
3447 EXPORT_SYMBOL(sock_no_accept);
3448 
3449 int sock_no_getname(struct socket *sock, struct sockaddr *saddr,
3450 		    int peer)
3451 {
3452 	return -EOPNOTSUPP;
3453 }
3454 EXPORT_SYMBOL(sock_no_getname);
3455 
3456 int sock_no_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
3457 {
3458 	return -EOPNOTSUPP;
3459 }
3460 EXPORT_SYMBOL(sock_no_ioctl);
3461 
3462 int sock_no_listen(struct socket *sock, int backlog)
3463 {
3464 	return -EOPNOTSUPP;
3465 }
3466 EXPORT_SYMBOL(sock_no_listen);
3467 
3468 int sock_no_shutdown(struct socket *sock, int how)
3469 {
3470 	return -EOPNOTSUPP;
3471 }
3472 EXPORT_SYMBOL(sock_no_shutdown);
3473 
3474 int sock_no_sendmsg(struct socket *sock, struct msghdr *m, size_t len)
3475 {
3476 	return -EOPNOTSUPP;
3477 }
3478 EXPORT_SYMBOL(sock_no_sendmsg);
3479 
3480 int sock_no_sendmsg_locked(struct sock *sk, struct msghdr *m, size_t len)
3481 {
3482 	return -EOPNOTSUPP;
3483 }
3484 EXPORT_SYMBOL(sock_no_sendmsg_locked);
3485 
3486 int sock_no_recvmsg(struct socket *sock, struct msghdr *m, size_t len,
3487 		    int flags)
3488 {
3489 	return -EOPNOTSUPP;
3490 }
3491 EXPORT_SYMBOL(sock_no_recvmsg);
3492 
3493 int sock_no_mmap(struct file *file, struct socket *sock, struct vm_area_struct *vma)
3494 {
3495 	/* Mirror missing mmap method error code */
3496 	return -ENODEV;
3497 }
3498 EXPORT_SYMBOL(sock_no_mmap);
3499 
3500 /*
3501  * When a file is received (via SCM_RIGHTS, etc), we must bump the
3502  * various sock-based usage counts.
3503  */
3504 void __receive_sock(struct file *file)
3505 {
3506 	struct socket *sock;
3507 
3508 	sock = sock_from_file(file);
3509 	if (sock) {
3510 		sock_update_netprioidx(&sock->sk->sk_cgrp_data);
3511 		sock_update_classid(&sock->sk->sk_cgrp_data);
3512 	}
3513 }
3514 
3515 /*
3516  *	Default Socket Callbacks
3517  */
3518 
3519 static void sock_def_wakeup(struct sock *sk)
3520 {
3521 	struct socket_wq *wq;
3522 
3523 	rcu_read_lock();
3524 	wq = rcu_dereference(sk->sk_wq);
3525 	if (skwq_has_sleeper(wq))
3526 		wake_up_interruptible_all(&wq->wait);
3527 	rcu_read_unlock();
3528 }
3529 
3530 static void sock_def_error_report(struct sock *sk)
3531 {
3532 	struct socket_wq *wq;
3533 
3534 	rcu_read_lock();
3535 	wq = rcu_dereference(sk->sk_wq);
3536 	if (skwq_has_sleeper(wq))
3537 		wake_up_interruptible_poll(&wq->wait, EPOLLERR);
3538 	sk_wake_async_rcu(sk, SOCK_WAKE_IO, POLL_ERR);
3539 	rcu_read_unlock();
3540 }
3541 
3542 void sock_def_readable(struct sock *sk)
3543 {
3544 	struct socket_wq *wq;
3545 
3546 	trace_sk_data_ready(sk);
3547 
3548 	rcu_read_lock();
3549 	wq = rcu_dereference(sk->sk_wq);
3550 	if (skwq_has_sleeper(wq))
3551 		wake_up_interruptible_sync_poll(&wq->wait, EPOLLIN | EPOLLPRI |
3552 						EPOLLRDNORM | EPOLLRDBAND);
3553 	sk_wake_async_rcu(sk, SOCK_WAKE_WAITD, POLL_IN);
3554 	rcu_read_unlock();
3555 }
3556 
3557 static void sock_def_write_space(struct sock *sk)
3558 {
3559 	struct socket_wq *wq;
3560 
3561 	rcu_read_lock();
3562 
3563 	/* Do not wake up a writer until he can make "significant"
3564 	 * progress.  --DaveM
3565 	 */
3566 	if (sock_writeable(sk)) {
3567 		wq = rcu_dereference(sk->sk_wq);
3568 		if (skwq_has_sleeper(wq))
3569 			wake_up_interruptible_sync_poll(&wq->wait, EPOLLOUT |
3570 						EPOLLWRNORM | EPOLLWRBAND);
3571 
3572 		/* Should agree with poll, otherwise some programs break */
3573 		sk_wake_async_rcu(sk, SOCK_WAKE_SPACE, POLL_OUT);
3574 	}
3575 
3576 	rcu_read_unlock();
3577 }
3578 
3579 /* An optimised version of sock_def_write_space(), should only be called
3580  * for SOCK_RCU_FREE sockets under RCU read section and after putting
3581  * ->sk_wmem_alloc.
3582  */
3583 static void sock_def_write_space_wfree(struct sock *sk)
3584 {
3585 	/* Do not wake up a writer until he can make "significant"
3586 	 * progress.  --DaveM
3587 	 */
3588 	if (sock_writeable(sk)) {
3589 		struct socket_wq *wq = rcu_dereference(sk->sk_wq);
3590 
3591 		/* rely on refcount_sub from sock_wfree() */
3592 		smp_mb__after_atomic();
3593 		if (wq && waitqueue_active(&wq->wait))
3594 			wake_up_interruptible_sync_poll(&wq->wait, EPOLLOUT |
3595 						EPOLLWRNORM | EPOLLWRBAND);
3596 
3597 		/* Should agree with poll, otherwise some programs break */
3598 		sk_wake_async_rcu(sk, SOCK_WAKE_SPACE, POLL_OUT);
3599 	}
3600 }
3601 
3602 static void sock_def_destruct(struct sock *sk)
3603 {
3604 }
3605 
3606 void sk_send_sigurg(struct sock *sk)
3607 {
3608 	if (sk->sk_socket && sk->sk_socket->file)
3609 		if (send_sigurg(sk->sk_socket->file))
3610 			sk_wake_async(sk, SOCK_WAKE_URG, POLL_PRI);
3611 }
3612 EXPORT_SYMBOL(sk_send_sigurg);
3613 
3614 void sk_reset_timer(struct sock *sk, struct timer_list* timer,
3615 		    unsigned long expires)
3616 {
3617 	if (!mod_timer(timer, expires))
3618 		sock_hold(sk);
3619 }
3620 EXPORT_SYMBOL(sk_reset_timer);
3621 
3622 void sk_stop_timer(struct sock *sk, struct timer_list* timer)
3623 {
3624 	if (timer_delete(timer))
3625 		__sock_put(sk);
3626 }
3627 EXPORT_SYMBOL(sk_stop_timer);
3628 
3629 void sk_stop_timer_sync(struct sock *sk, struct timer_list *timer)
3630 {
3631 	if (timer_delete_sync(timer))
3632 		__sock_put(sk);
3633 }
3634 EXPORT_SYMBOL(sk_stop_timer_sync);
3635 
3636 void sock_init_data_uid(struct socket *sock, struct sock *sk, kuid_t uid)
3637 {
3638 	sk_init_common(sk);
3639 	sk->sk_send_head	=	NULL;
3640 
3641 	timer_setup(&sk->sk_timer, NULL, 0);
3642 
3643 	sk->sk_allocation	=	GFP_KERNEL;
3644 	sk->sk_rcvbuf		=	READ_ONCE(sysctl_rmem_default);
3645 	sk->sk_sndbuf		=	READ_ONCE(sysctl_wmem_default);
3646 	sk->sk_state		=	TCP_CLOSE;
3647 	sk->sk_use_task_frag	=	true;
3648 	sk_set_socket(sk, sock);
3649 
3650 	sock_set_flag(sk, SOCK_ZAPPED);
3651 
3652 	if (sock) {
3653 		sk->sk_type	=	sock->type;
3654 		RCU_INIT_POINTER(sk->sk_wq, &sock->wq);
3655 		sock->sk	=	sk;
3656 	} else {
3657 		RCU_INIT_POINTER(sk->sk_wq, NULL);
3658 	}
3659 	sk->sk_uid	=	uid;
3660 
3661 	sk->sk_state_change	=	sock_def_wakeup;
3662 	sk->sk_data_ready	=	sock_def_readable;
3663 	sk->sk_write_space	=	sock_def_write_space;
3664 	sk->sk_error_report	=	sock_def_error_report;
3665 	sk->sk_destruct		=	sock_def_destruct;
3666 
3667 	sk->sk_frag.page	=	NULL;
3668 	sk->sk_frag.offset	=	0;
3669 	sk->sk_peek_off		=	-1;
3670 
3671 	sk->sk_peer_pid 	=	NULL;
3672 	sk->sk_peer_cred	=	NULL;
3673 	spin_lock_init(&sk->sk_peer_lock);
3674 
3675 	sk->sk_write_pending	=	0;
3676 	sk->sk_rcvlowat		=	1;
3677 	sk->sk_rcvtimeo		=	MAX_SCHEDULE_TIMEOUT;
3678 	sk->sk_sndtimeo		=	MAX_SCHEDULE_TIMEOUT;
3679 
3680 	sk->sk_stamp = SK_DEFAULT_STAMP;
3681 #if BITS_PER_LONG==32
3682 	seqlock_init(&sk->sk_stamp_seq);
3683 #endif
3684 	atomic_set(&sk->sk_zckey, 0);
3685 
3686 #ifdef CONFIG_NET_RX_BUSY_POLL
3687 	sk->sk_napi_id		=	0;
3688 	sk->sk_ll_usec		=	READ_ONCE(sysctl_net_busy_read);
3689 #endif
3690 
3691 	sk->sk_max_pacing_rate = ~0UL;
3692 	sk->sk_pacing_rate = ~0UL;
3693 	WRITE_ONCE(sk->sk_pacing_shift, 10);
3694 	sk->sk_incoming_cpu = -1;
3695 
3696 	sk_rx_queue_clear(sk);
3697 	/*
3698 	 * Before updating sk_refcnt, we must commit prior changes to memory
3699 	 * (Documentation/RCU/rculist_nulls.rst for details)
3700 	 */
3701 	smp_wmb();
3702 	refcount_set(&sk->sk_refcnt, 1);
3703 	sk_drops_reset(sk);
3704 }
3705 EXPORT_SYMBOL(sock_init_data_uid);
3706 
3707 void sock_init_data(struct socket *sock, struct sock *sk)
3708 {
3709 	kuid_t uid = sock ?
3710 		SOCK_INODE(sock)->i_uid :
3711 		make_kuid(sock_net(sk)->user_ns, 0);
3712 
3713 	sock_init_data_uid(sock, sk, uid);
3714 }
3715 EXPORT_SYMBOL(sock_init_data);
3716 
3717 void lock_sock_nested(struct sock *sk, int subclass)
3718 {
3719 	/* The sk_lock has mutex_lock() semantics here. */
3720 	mutex_acquire(&sk->sk_lock.dep_map, subclass, 0, _RET_IP_);
3721 
3722 	might_sleep();
3723 	spin_lock_bh(&sk->sk_lock.slock);
3724 	if (sock_owned_by_user_nocheck(sk))
3725 		__lock_sock(sk);
3726 	sk->sk_lock.owned = 1;
3727 	spin_unlock_bh(&sk->sk_lock.slock);
3728 }
3729 EXPORT_SYMBOL(lock_sock_nested);
3730 
3731 void release_sock(struct sock *sk)
3732 {
3733 	spin_lock_bh(&sk->sk_lock.slock);
3734 	if (sk->sk_backlog.tail)
3735 		__release_sock(sk);
3736 
3737 	if (sk->sk_prot->release_cb)
3738 		INDIRECT_CALL_INET_1(sk->sk_prot->release_cb,
3739 				     tcp_release_cb, sk);
3740 
3741 	sock_release_ownership(sk);
3742 	if (waitqueue_active(&sk->sk_lock.wq))
3743 		wake_up(&sk->sk_lock.wq);
3744 	spin_unlock_bh(&sk->sk_lock.slock);
3745 }
3746 EXPORT_SYMBOL(release_sock);
3747 
3748 bool __lock_sock_fast(struct sock *sk) __acquires(&sk->sk_lock.slock)
3749 {
3750 	might_sleep();
3751 	spin_lock_bh(&sk->sk_lock.slock);
3752 
3753 	if (!sock_owned_by_user_nocheck(sk)) {
3754 		/*
3755 		 * Fast path return with bottom halves disabled and
3756 		 * sock::sk_lock.slock held.
3757 		 *
3758 		 * The 'mutex' is not contended and holding
3759 		 * sock::sk_lock.slock prevents all other lockers to
3760 		 * proceed so the corresponding unlock_sock_fast() can
3761 		 * avoid the slow path of release_sock() completely and
3762 		 * just release slock.
3763 		 *
3764 		 * From a semantical POV this is equivalent to 'acquiring'
3765 		 * the 'mutex', hence the corresponding lockdep
3766 		 * mutex_release() has to happen in the fast path of
3767 		 * unlock_sock_fast().
3768 		 */
3769 		return false;
3770 	}
3771 
3772 	__lock_sock(sk);
3773 	sk->sk_lock.owned = 1;
3774 	__acquire(&sk->sk_lock.slock);
3775 	spin_unlock_bh(&sk->sk_lock.slock);
3776 	return true;
3777 }
3778 EXPORT_SYMBOL(__lock_sock_fast);
3779 
3780 int sock_gettstamp(struct socket *sock, void __user *userstamp,
3781 		   bool timeval, bool time32)
3782 {
3783 	struct sock *sk = sock->sk;
3784 	struct timespec64 ts;
3785 
3786 	sock_enable_timestamp(sk, SOCK_TIMESTAMP);
3787 	ts = ktime_to_timespec64(sock_read_timestamp(sk));
3788 	if (ts.tv_sec == -1)
3789 		return -ENOENT;
3790 	if (ts.tv_sec == 0) {
3791 		ktime_t kt = ktime_get_real();
3792 		sock_write_timestamp(sk, kt);
3793 		ts = ktime_to_timespec64(kt);
3794 	}
3795 
3796 	if (timeval)
3797 		ts.tv_nsec /= 1000;
3798 
3799 #ifdef CONFIG_COMPAT_32BIT_TIME
3800 	if (time32)
3801 		return put_old_timespec32(&ts, userstamp);
3802 #endif
3803 #ifdef CONFIG_SPARC64
3804 	/* beware of padding in sparc64 timeval */
3805 	if (timeval && !in_compat_syscall()) {
3806 		struct __kernel_old_timeval __user tv = {
3807 			.tv_sec = ts.tv_sec,
3808 			.tv_usec = ts.tv_nsec,
3809 		};
3810 		if (copy_to_user(userstamp, &tv, sizeof(tv)))
3811 			return -EFAULT;
3812 		return 0;
3813 	}
3814 #endif
3815 	return put_timespec64(&ts, userstamp);
3816 }
3817 EXPORT_SYMBOL(sock_gettstamp);
3818 
3819 void sock_enable_timestamp(struct sock *sk, enum sock_flags flag)
3820 {
3821 	if (!sock_flag(sk, flag)) {
3822 		unsigned long previous_flags = sk->sk_flags;
3823 
3824 		sock_set_flag(sk, flag);
3825 		/*
3826 		 * we just set one of the two flags which require net
3827 		 * time stamping, but time stamping might have been on
3828 		 * already because of the other one
3829 		 */
3830 		if (sock_needs_netstamp(sk) &&
3831 		    !(previous_flags & SK_FLAGS_TIMESTAMP))
3832 			net_enable_timestamp();
3833 	}
3834 }
3835 
3836 int sock_recv_errqueue(struct sock *sk, struct msghdr *msg, int len,
3837 		       int level, int type)
3838 {
3839 	struct sock_exterr_skb *serr;
3840 	struct sk_buff *skb;
3841 	int copied, err;
3842 
3843 	err = -EAGAIN;
3844 	skb = sock_dequeue_err_skb(sk);
3845 	if (skb == NULL)
3846 		goto out;
3847 
3848 	copied = skb->len;
3849 	if (copied > len) {
3850 		msg->msg_flags |= MSG_TRUNC;
3851 		copied = len;
3852 	}
3853 	err = skb_copy_datagram_msg(skb, 0, msg, copied);
3854 	if (err)
3855 		goto out_free_skb;
3856 
3857 	sock_recv_timestamp(msg, sk, skb);
3858 
3859 	serr = SKB_EXT_ERR(skb);
3860 	put_cmsg(msg, level, type, sizeof(serr->ee), &serr->ee);
3861 
3862 	msg->msg_flags |= MSG_ERRQUEUE;
3863 	err = copied;
3864 
3865 out_free_skb:
3866 	kfree_skb(skb);
3867 out:
3868 	return err;
3869 }
3870 EXPORT_SYMBOL(sock_recv_errqueue);
3871 
3872 /*
3873  *	Get a socket option on an socket.
3874  *
3875  *	FIX: POSIX 1003.1g is very ambiguous here. It states that
3876  *	asynchronous errors should be reported by getsockopt. We assume
3877  *	this means if you specify SO_ERROR (otherwise what is the point of it).
3878  */
3879 int sock_common_getsockopt(struct socket *sock, int level, int optname,
3880 			   char __user *optval, int __user *optlen)
3881 {
3882 	struct sock *sk = sock->sk;
3883 
3884 	/* IPV6_ADDRFORM can change sk->sk_prot under us. */
3885 	return READ_ONCE(sk->sk_prot)->getsockopt(sk, level, optname, optval, optlen);
3886 }
3887 EXPORT_SYMBOL(sock_common_getsockopt);
3888 
3889 int sock_common_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
3890 			int flags)
3891 {
3892 	struct sock *sk = sock->sk;
3893 	int addr_len = 0;
3894 	int err;
3895 
3896 	err = sk->sk_prot->recvmsg(sk, msg, size, flags, &addr_len);
3897 	if (err >= 0)
3898 		msg->msg_namelen = addr_len;
3899 	return err;
3900 }
3901 EXPORT_SYMBOL(sock_common_recvmsg);
3902 
3903 /*
3904  *	Set socket options on an inet socket.
3905  */
3906 int sock_common_setsockopt(struct socket *sock, int level, int optname,
3907 			   sockptr_t optval, unsigned int optlen)
3908 {
3909 	struct sock *sk = sock->sk;
3910 
3911 	/* IPV6_ADDRFORM can change sk->sk_prot under us. */
3912 	return READ_ONCE(sk->sk_prot)->setsockopt(sk, level, optname, optval, optlen);
3913 }
3914 EXPORT_SYMBOL(sock_common_setsockopt);
3915 
3916 void sk_common_release(struct sock *sk)
3917 {
3918 	if (sk->sk_prot->destroy)
3919 		sk->sk_prot->destroy(sk);
3920 
3921 	/*
3922 	 * Observation: when sk_common_release is called, processes have
3923 	 * no access to socket. But net still has.
3924 	 * Step one, detach it from networking:
3925 	 *
3926 	 * A. Remove from hash tables.
3927 	 */
3928 
3929 	sk->sk_prot->unhash(sk);
3930 
3931 	/*
3932 	 * In this point socket cannot receive new packets, but it is possible
3933 	 * that some packets are in flight because some CPU runs receiver and
3934 	 * did hash table lookup before we unhashed socket. They will achieve
3935 	 * receive queue and will be purged by socket destructor.
3936 	 *
3937 	 * Also we still have packets pending on receive queue and probably,
3938 	 * our own packets waiting in device queues. sock_destroy will drain
3939 	 * receive queue, but transmitted packets will delay socket destruction
3940 	 * until the last reference will be released.
3941 	 */
3942 
3943 	sock_orphan(sk);
3944 
3945 	xfrm_sk_free_policy(sk);
3946 
3947 	sock_put(sk);
3948 }
3949 EXPORT_SYMBOL(sk_common_release);
3950 
3951 void sk_get_meminfo(const struct sock *sk, u32 *mem)
3952 {
3953 	memset(mem, 0, sizeof(*mem) * SK_MEMINFO_VARS);
3954 
3955 	mem[SK_MEMINFO_RMEM_ALLOC] = sk_rmem_alloc_get(sk);
3956 	mem[SK_MEMINFO_RCVBUF] = READ_ONCE(sk->sk_rcvbuf);
3957 	mem[SK_MEMINFO_WMEM_ALLOC] = sk_wmem_alloc_get(sk);
3958 	mem[SK_MEMINFO_SNDBUF] = READ_ONCE(sk->sk_sndbuf);
3959 	mem[SK_MEMINFO_FWD_ALLOC] = READ_ONCE(sk->sk_forward_alloc);
3960 	mem[SK_MEMINFO_WMEM_QUEUED] = READ_ONCE(sk->sk_wmem_queued);
3961 	mem[SK_MEMINFO_OPTMEM] = atomic_read(&sk->sk_omem_alloc);
3962 	mem[SK_MEMINFO_BACKLOG] = READ_ONCE(sk->sk_backlog.len);
3963 	mem[SK_MEMINFO_DROPS] = sk_drops_read(sk);
3964 }
3965 
3966 #ifdef CONFIG_PROC_FS
3967 static DECLARE_BITMAP(proto_inuse_idx, PROTO_INUSE_NR);
3968 
3969 int sock_prot_inuse_get(struct net *net, struct proto *prot)
3970 {
3971 	int cpu, idx = prot->inuse_idx;
3972 	int res = 0;
3973 
3974 	for_each_possible_cpu(cpu)
3975 		res += per_cpu_ptr(net->core.prot_inuse, cpu)->val[idx];
3976 
3977 	return res >= 0 ? res : 0;
3978 }
3979 EXPORT_SYMBOL_GPL(sock_prot_inuse_get);
3980 
3981 int sock_inuse_get(struct net *net)
3982 {
3983 	int cpu, res = 0;
3984 
3985 	for_each_possible_cpu(cpu)
3986 		res += per_cpu_ptr(net->core.prot_inuse, cpu)->all;
3987 
3988 	return res;
3989 }
3990 
3991 EXPORT_SYMBOL_GPL(sock_inuse_get);
3992 
3993 static int __net_init sock_inuse_init_net(struct net *net)
3994 {
3995 	net->core.prot_inuse = alloc_percpu(struct prot_inuse);
3996 	if (net->core.prot_inuse == NULL)
3997 		return -ENOMEM;
3998 	return 0;
3999 }
4000 
4001 static void __net_exit sock_inuse_exit_net(struct net *net)
4002 {
4003 	free_percpu(net->core.prot_inuse);
4004 }
4005 
4006 static struct pernet_operations net_inuse_ops = {
4007 	.init = sock_inuse_init_net,
4008 	.exit = sock_inuse_exit_net,
4009 };
4010 
4011 static __init int net_inuse_init(void)
4012 {
4013 	if (register_pernet_subsys(&net_inuse_ops))
4014 		panic("Cannot initialize net inuse counters");
4015 
4016 	return 0;
4017 }
4018 
4019 core_initcall(net_inuse_init);
4020 
4021 static int assign_proto_idx(struct proto *prot)
4022 {
4023 	prot->inuse_idx = find_first_zero_bit(proto_inuse_idx, PROTO_INUSE_NR);
4024 
4025 	if (unlikely(prot->inuse_idx == PROTO_INUSE_NR)) {
4026 		pr_err("PROTO_INUSE_NR exhausted\n");
4027 		return -ENOSPC;
4028 	}
4029 
4030 	set_bit(prot->inuse_idx, proto_inuse_idx);
4031 	return 0;
4032 }
4033 
4034 static void release_proto_idx(struct proto *prot)
4035 {
4036 	if (prot->inuse_idx != PROTO_INUSE_NR)
4037 		clear_bit(prot->inuse_idx, proto_inuse_idx);
4038 }
4039 #else
4040 static inline int assign_proto_idx(struct proto *prot)
4041 {
4042 	return 0;
4043 }
4044 
4045 static inline void release_proto_idx(struct proto *prot)
4046 {
4047 }
4048 
4049 #endif
4050 
4051 static void tw_prot_cleanup(struct timewait_sock_ops *twsk_prot)
4052 {
4053 	if (!twsk_prot)
4054 		return;
4055 	kfree(twsk_prot->twsk_slab_name);
4056 	twsk_prot->twsk_slab_name = NULL;
4057 	kmem_cache_destroy(twsk_prot->twsk_slab);
4058 	twsk_prot->twsk_slab = NULL;
4059 }
4060 
4061 static int tw_prot_init(const struct proto *prot)
4062 {
4063 	struct timewait_sock_ops *twsk_prot = prot->twsk_prot;
4064 
4065 	if (!twsk_prot)
4066 		return 0;
4067 
4068 	twsk_prot->twsk_slab_name = kasprintf(GFP_KERNEL, "tw_sock_%s",
4069 					      prot->name);
4070 	if (!twsk_prot->twsk_slab_name)
4071 		return -ENOMEM;
4072 
4073 	twsk_prot->twsk_slab =
4074 		kmem_cache_create(twsk_prot->twsk_slab_name,
4075 				  twsk_prot->twsk_obj_size, 0,
4076 				  SLAB_ACCOUNT | prot->slab_flags,
4077 				  NULL);
4078 	if (!twsk_prot->twsk_slab) {
4079 		pr_crit("%s: Can't create timewait sock SLAB cache!\n",
4080 			prot->name);
4081 		return -ENOMEM;
4082 	}
4083 
4084 	return 0;
4085 }
4086 
4087 static void req_prot_cleanup(struct request_sock_ops *rsk_prot)
4088 {
4089 	if (!rsk_prot)
4090 		return;
4091 	kfree(rsk_prot->slab_name);
4092 	rsk_prot->slab_name = NULL;
4093 	kmem_cache_destroy(rsk_prot->slab);
4094 	rsk_prot->slab = NULL;
4095 }
4096 
4097 static int req_prot_init(const struct proto *prot)
4098 {
4099 	struct request_sock_ops *rsk_prot = prot->rsk_prot;
4100 
4101 	if (!rsk_prot)
4102 		return 0;
4103 
4104 	rsk_prot->slab_name = kasprintf(GFP_KERNEL, "request_sock_%s",
4105 					prot->name);
4106 	if (!rsk_prot->slab_name)
4107 		return -ENOMEM;
4108 
4109 	rsk_prot->slab = kmem_cache_create(rsk_prot->slab_name,
4110 					   rsk_prot->obj_size, 0,
4111 					   SLAB_ACCOUNT | prot->slab_flags,
4112 					   NULL);
4113 
4114 	if (!rsk_prot->slab) {
4115 		pr_crit("%s: Can't create request sock SLAB cache!\n",
4116 			prot->name);
4117 		return -ENOMEM;
4118 	}
4119 	return 0;
4120 }
4121 
4122 int proto_register(struct proto *prot, int alloc_slab)
4123 {
4124 	int ret = -ENOBUFS;
4125 
4126 	if (prot->memory_allocated && !prot->sysctl_mem) {
4127 		pr_err("%s: missing sysctl_mem\n", prot->name);
4128 		return -EINVAL;
4129 	}
4130 	if (prot->memory_allocated && !prot->per_cpu_fw_alloc) {
4131 		pr_err("%s: missing per_cpu_fw_alloc\n", prot->name);
4132 		return -EINVAL;
4133 	}
4134 	if (alloc_slab) {
4135 		prot->slab = kmem_cache_create_usercopy(prot->name,
4136 					prot->obj_size, 0,
4137 					SLAB_HWCACHE_ALIGN | SLAB_ACCOUNT |
4138 					prot->slab_flags,
4139 					prot->useroffset, prot->usersize,
4140 					NULL);
4141 
4142 		if (prot->slab == NULL) {
4143 			pr_crit("%s: Can't create sock SLAB cache!\n",
4144 				prot->name);
4145 			goto out;
4146 		}
4147 
4148 		if (req_prot_init(prot))
4149 			goto out_free_request_sock_slab;
4150 
4151 		if (tw_prot_init(prot))
4152 			goto out_free_timewait_sock_slab;
4153 	}
4154 
4155 	mutex_lock(&proto_list_mutex);
4156 	ret = assign_proto_idx(prot);
4157 	if (ret) {
4158 		mutex_unlock(&proto_list_mutex);
4159 		goto out_free_timewait_sock_slab;
4160 	}
4161 	list_add(&prot->node, &proto_list);
4162 	mutex_unlock(&proto_list_mutex);
4163 	return ret;
4164 
4165 out_free_timewait_sock_slab:
4166 	if (alloc_slab)
4167 		tw_prot_cleanup(prot->twsk_prot);
4168 out_free_request_sock_slab:
4169 	if (alloc_slab) {
4170 		req_prot_cleanup(prot->rsk_prot);
4171 
4172 		kmem_cache_destroy(prot->slab);
4173 		prot->slab = NULL;
4174 	}
4175 out:
4176 	return ret;
4177 }
4178 EXPORT_SYMBOL(proto_register);
4179 
4180 void proto_unregister(struct proto *prot)
4181 {
4182 	mutex_lock(&proto_list_mutex);
4183 	release_proto_idx(prot);
4184 	list_del(&prot->node);
4185 	mutex_unlock(&proto_list_mutex);
4186 
4187 	kmem_cache_destroy(prot->slab);
4188 	prot->slab = NULL;
4189 
4190 	req_prot_cleanup(prot->rsk_prot);
4191 	tw_prot_cleanup(prot->twsk_prot);
4192 }
4193 EXPORT_SYMBOL(proto_unregister);
4194 
4195 int sock_load_diag_module(int family, int protocol)
4196 {
4197 	if (!protocol) {
4198 		if (!sock_is_registered(family))
4199 			return -ENOENT;
4200 
4201 		return request_module("net-pf-%d-proto-%d-type-%d", PF_NETLINK,
4202 				      NETLINK_SOCK_DIAG, family);
4203 	}
4204 
4205 #ifdef CONFIG_INET
4206 	if (family == AF_INET &&
4207 	    protocol != IPPROTO_RAW &&
4208 	    protocol < MAX_INET_PROTOS &&
4209 	    !rcu_access_pointer(inet_protos[protocol]))
4210 		return -ENOENT;
4211 #endif
4212 
4213 	return request_module("net-pf-%d-proto-%d-type-%d-%d", PF_NETLINK,
4214 			      NETLINK_SOCK_DIAG, family, protocol);
4215 }
4216 EXPORT_SYMBOL(sock_load_diag_module);
4217 
4218 #ifdef CONFIG_PROC_FS
4219 static void *proto_seq_start(struct seq_file *seq, loff_t *pos)
4220 	__acquires(proto_list_mutex)
4221 {
4222 	mutex_lock(&proto_list_mutex);
4223 	return seq_list_start_head(&proto_list, *pos);
4224 }
4225 
4226 static void *proto_seq_next(struct seq_file *seq, void *v, loff_t *pos)
4227 {
4228 	return seq_list_next(v, &proto_list, pos);
4229 }
4230 
4231 static void proto_seq_stop(struct seq_file *seq, void *v)
4232 	__releases(proto_list_mutex)
4233 {
4234 	mutex_unlock(&proto_list_mutex);
4235 }
4236 
4237 static char proto_method_implemented(const void *method)
4238 {
4239 	return method == NULL ? 'n' : 'y';
4240 }
4241 static long sock_prot_memory_allocated(struct proto *proto)
4242 {
4243 	return proto->memory_allocated != NULL ? proto_memory_allocated(proto) : -1L;
4244 }
4245 
4246 static const char *sock_prot_memory_pressure(struct proto *proto)
4247 {
4248 	return proto->memory_pressure != NULL ?
4249 	proto_memory_pressure(proto) ? "yes" : "no" : "NI";
4250 }
4251 
4252 static void proto_seq_printf(struct seq_file *seq, struct proto *proto)
4253 {
4254 
4255 	seq_printf(seq, "%-9s %4u %6d  %6ld   %-3s %6u   %-3s  %-10s "
4256 			"%2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c\n",
4257 		   proto->name,
4258 		   proto->obj_size,
4259 		   sock_prot_inuse_get(seq_file_net(seq), proto),
4260 		   sock_prot_memory_allocated(proto),
4261 		   sock_prot_memory_pressure(proto),
4262 		   proto->max_header,
4263 		   proto->slab == NULL ? "no" : "yes",
4264 		   module_name(proto->owner),
4265 		   proto_method_implemented(proto->close),
4266 		   proto_method_implemented(proto->connect),
4267 		   proto_method_implemented(proto->disconnect),
4268 		   proto_method_implemented(proto->accept),
4269 		   proto_method_implemented(proto->ioctl),
4270 		   proto_method_implemented(proto->init),
4271 		   proto_method_implemented(proto->destroy),
4272 		   proto_method_implemented(proto->shutdown),
4273 		   proto_method_implemented(proto->setsockopt),
4274 		   proto_method_implemented(proto->getsockopt),
4275 		   proto_method_implemented(proto->sendmsg),
4276 		   proto_method_implemented(proto->recvmsg),
4277 		   proto_method_implemented(proto->bind),
4278 		   proto_method_implemented(proto->backlog_rcv),
4279 		   proto_method_implemented(proto->hash),
4280 		   proto_method_implemented(proto->unhash),
4281 		   proto_method_implemented(proto->get_port),
4282 		   proto_method_implemented(proto->enter_memory_pressure));
4283 }
4284 
4285 static int proto_seq_show(struct seq_file *seq, void *v)
4286 {
4287 	if (v == &proto_list)
4288 		seq_printf(seq, "%-9s %-4s %-8s %-6s %-5s %-7s %-4s %-10s %s",
4289 			   "protocol",
4290 			   "size",
4291 			   "sockets",
4292 			   "memory",
4293 			   "press",
4294 			   "maxhdr",
4295 			   "slab",
4296 			   "module",
4297 			   "cl co di ac io in de sh ss gs se re bi br ha uh gp em\n");
4298 	else
4299 		proto_seq_printf(seq, list_entry(v, struct proto, node));
4300 	return 0;
4301 }
4302 
4303 static const struct seq_operations proto_seq_ops = {
4304 	.start  = proto_seq_start,
4305 	.next   = proto_seq_next,
4306 	.stop   = proto_seq_stop,
4307 	.show   = proto_seq_show,
4308 };
4309 
4310 static __net_init int proto_init_net(struct net *net)
4311 {
4312 	if (!proc_create_net("protocols", 0444, net->proc_net, &proto_seq_ops,
4313 			sizeof(struct seq_net_private)))
4314 		return -ENOMEM;
4315 
4316 	return 0;
4317 }
4318 
4319 static __net_exit void proto_exit_net(struct net *net)
4320 {
4321 	remove_proc_entry("protocols", net->proc_net);
4322 }
4323 
4324 
4325 static __net_initdata struct pernet_operations proto_net_ops = {
4326 	.init = proto_init_net,
4327 	.exit = proto_exit_net,
4328 };
4329 
4330 static int __init proto_init(void)
4331 {
4332 	return register_pernet_subsys(&proto_net_ops);
4333 }
4334 
4335 subsys_initcall(proto_init);
4336 
4337 #endif /* PROC_FS */
4338 
4339 #ifdef CONFIG_NET_RX_BUSY_POLL
4340 bool sk_busy_loop_end(void *p, unsigned long start_time)
4341 {
4342 	struct sock *sk = p;
4343 
4344 	if (!skb_queue_empty_lockless(&sk->sk_receive_queue))
4345 		return true;
4346 
4347 	if (sk_is_udp(sk) &&
4348 	    !skb_queue_empty_lockless(&udp_sk(sk)->reader_queue))
4349 		return true;
4350 
4351 	return sk_busy_loop_timeout(sk, start_time);
4352 }
4353 EXPORT_SYMBOL(sk_busy_loop_end);
4354 #endif /* CONFIG_NET_RX_BUSY_POLL */
4355 
4356 int sock_bind_add(struct sock *sk, struct sockaddr *addr, int addr_len)
4357 {
4358 	if (!sk->sk_prot->bind_add)
4359 		return -EOPNOTSUPP;
4360 	return sk->sk_prot->bind_add(sk, addr, addr_len);
4361 }
4362 EXPORT_SYMBOL(sock_bind_add);
4363 
4364 /* Copy 'size' bytes from userspace and return `size` back to userspace */
4365 int sock_ioctl_inout(struct sock *sk, unsigned int cmd,
4366 		     void __user *arg, void *karg, size_t size)
4367 {
4368 	int ret;
4369 
4370 	if (copy_from_user(karg, arg, size))
4371 		return -EFAULT;
4372 
4373 	ret = READ_ONCE(sk->sk_prot)->ioctl(sk, cmd, karg);
4374 	if (ret)
4375 		return ret;
4376 
4377 	if (copy_to_user(arg, karg, size))
4378 		return -EFAULT;
4379 
4380 	return 0;
4381 }
4382 EXPORT_SYMBOL(sock_ioctl_inout);
4383 
4384 /* This is the most common ioctl prep function, where the result (4 bytes) is
4385  * copied back to userspace if the ioctl() returns successfully. No input is
4386  * copied from userspace as input argument.
4387  */
4388 static int sock_ioctl_out(struct sock *sk, unsigned int cmd, void __user *arg)
4389 {
4390 	int ret, karg = 0;
4391 
4392 	ret = READ_ONCE(sk->sk_prot)->ioctl(sk, cmd, &karg);
4393 	if (ret)
4394 		return ret;
4395 
4396 	return put_user(karg, (int __user *)arg);
4397 }
4398 
4399 /* A wrapper around sock ioctls, which copies the data from userspace
4400  * (depending on the protocol/ioctl), and copies back the result to userspace.
4401  * The main motivation for this function is to pass kernel memory to the
4402  * protocol ioctl callbacks, instead of userspace memory.
4403  */
4404 int sk_ioctl(struct sock *sk, unsigned int cmd, void __user *arg)
4405 {
4406 	int rc = 1;
4407 
4408 	if (sk->sk_type == SOCK_RAW && sk->sk_family == AF_INET)
4409 		rc = ipmr_sk_ioctl(sk, cmd, arg);
4410 	else if (sk->sk_type == SOCK_RAW && sk->sk_family == AF_INET6)
4411 		rc = ip6mr_sk_ioctl(sk, cmd, arg);
4412 	else if (sk_is_phonet(sk))
4413 		rc = phonet_sk_ioctl(sk, cmd, arg);
4414 
4415 	/* If ioctl was processed, returns its value */
4416 	if (rc <= 0)
4417 		return rc;
4418 
4419 	/* Otherwise call the default handler */
4420 	return sock_ioctl_out(sk, cmd, arg);
4421 }
4422 EXPORT_SYMBOL(sk_ioctl);
4423 
4424 static int __init sock_struct_check(void)
4425 {
4426 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_rx, sk_drops);
4427 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_rx, sk_peek_off);
4428 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_rx, sk_error_queue);
4429 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_rx, sk_receive_queue);
4430 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_rx, sk_backlog);
4431 
4432 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_rx, sk_rx_dst);
4433 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_rx, sk_rx_dst_ifindex);
4434 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_rx, sk_rx_dst_cookie);
4435 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_rx, sk_rcvbuf);
4436 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_rx, sk_filter);
4437 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_rx, sk_wq);
4438 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_rx, sk_data_ready);
4439 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_rx, sk_rcvtimeo);
4440 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_rx, sk_rcvlowat);
4441 
4442 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_rxtx, sk_err);
4443 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_rxtx, sk_socket);
4444 #ifdef CONFIG_MEMCG
4445 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_rxtx, sk_memcg);
4446 #endif
4447 
4448 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_rxtx, sk_lock);
4449 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_rxtx, sk_reserved_mem);
4450 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_rxtx, sk_forward_alloc);
4451 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_rxtx, sk_tsflags);
4452 
4453 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_omem_alloc);
4454 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_omem_alloc);
4455 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_err_soft);
4456 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_wmem_queued);
4457 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_wmem_alloc);
4458 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_tsq_flags);
4459 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_send_head);
4460 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_write_queue);
4461 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_write_pending);
4462 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_dst_pending_confirm);
4463 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_pacing_status);
4464 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_frag);
4465 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_timer);
4466 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_pacing_rate);
4467 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_zckey);
4468 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_tskey);
4469 
4470 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_max_pacing_rate);
4471 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_sndtimeo);
4472 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_priority);
4473 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_mark);
4474 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_uid);
4475 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_protocol);
4476 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_dst_cache);
4477 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_route_caps);
4478 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_gso_type);
4479 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_gso_max_size);
4480 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_allocation);
4481 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_txhash);
4482 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_sndbuf);
4483 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_gso_max_segs);
4484 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_pacing_shift);
4485 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_use_task_frag);
4486 	return 0;
4487 }
4488 
4489 core_initcall(sock_struct_check);
4490