xref: /linux/net/core/sock.c (revision 7a7c52645ce62314cdd69815e9d8fcb33e0042d5)
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, struct dst_entry *dst)
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(dst_dev(dst)->gso_max_size) :
2601 			READ_ONCE(dst_dev(dst)->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 	u32 max_segs = 1;
2611 
2612 	sk->sk_route_caps = dst_dev(dst)->features;
2613 	if (sk_is_tcp(sk)) {
2614 		struct inet_connection_sock *icsk = inet_csk(sk);
2615 
2616 		sk->sk_route_caps |= NETIF_F_GSO;
2617 		icsk->icsk_ack.dst_quick_ack = dst_metric(dst, RTAX_QUICKACK);
2618 	}
2619 	if (sk->sk_route_caps & NETIF_F_GSO)
2620 		sk->sk_route_caps |= NETIF_F_GSO_SOFTWARE;
2621 	if (unlikely(sk->sk_gso_disabled))
2622 		sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
2623 	if (sk_can_gso(sk)) {
2624 		if (dst->header_len && !xfrm_dst_offload_ok(dst)) {
2625 			sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
2626 		} else {
2627 			sk->sk_route_caps |= NETIF_F_SG | NETIF_F_HW_CSUM;
2628 			sk->sk_gso_max_size = sk_dst_gso_max_size(sk, dst);
2629 			/* pairs with the WRITE_ONCE() in netif_set_gso_max_segs() */
2630 			max_segs = max_t(u32, READ_ONCE(dst_dev(dst)->gso_max_segs), 1);
2631 		}
2632 	}
2633 	sk->sk_gso_max_segs = max_segs;
2634 	sk_dst_set(sk, dst);
2635 }
2636 EXPORT_SYMBOL_GPL(sk_setup_caps);
2637 
2638 /*
2639  *	Simple resource managers for sockets.
2640  */
2641 
2642 
2643 /*
2644  * Write buffer destructor automatically called from kfree_skb.
2645  */
2646 void sock_wfree(struct sk_buff *skb)
2647 {
2648 	struct sock *sk = skb->sk;
2649 	unsigned int len = skb->truesize;
2650 	bool free;
2651 
2652 	if (!sock_flag(sk, SOCK_USE_WRITE_QUEUE)) {
2653 		if (sock_flag(sk, SOCK_RCU_FREE) &&
2654 		    sk->sk_write_space == sock_def_write_space) {
2655 			rcu_read_lock();
2656 			free = refcount_sub_and_test(len, &sk->sk_wmem_alloc);
2657 			sock_def_write_space_wfree(sk);
2658 			rcu_read_unlock();
2659 			if (unlikely(free))
2660 				__sk_free(sk);
2661 			return;
2662 		}
2663 
2664 		/*
2665 		 * Keep a reference on sk_wmem_alloc, this will be released
2666 		 * after sk_write_space() call
2667 		 */
2668 		WARN_ON(refcount_sub_and_test(len - 1, &sk->sk_wmem_alloc));
2669 		sk->sk_write_space(sk);
2670 		len = 1;
2671 	}
2672 	/*
2673 	 * if sk_wmem_alloc reaches 0, we must finish what sk_free()
2674 	 * could not do because of in-flight packets
2675 	 */
2676 	if (refcount_sub_and_test(len, &sk->sk_wmem_alloc))
2677 		__sk_free(sk);
2678 }
2679 EXPORT_SYMBOL(sock_wfree);
2680 
2681 /* This variant of sock_wfree() is used by TCP,
2682  * since it sets SOCK_USE_WRITE_QUEUE.
2683  */
2684 void __sock_wfree(struct sk_buff *skb)
2685 {
2686 	struct sock *sk = skb->sk;
2687 
2688 	if (refcount_sub_and_test(skb->truesize, &sk->sk_wmem_alloc))
2689 		__sk_free(sk);
2690 }
2691 
2692 void skb_set_owner_w(struct sk_buff *skb, struct sock *sk)
2693 {
2694 	skb_orphan(skb);
2695 #ifdef CONFIG_INET
2696 	if (unlikely(!sk_fullsock(sk)))
2697 		return skb_set_owner_edemux(skb, sk);
2698 #endif
2699 	skb->sk = sk;
2700 	skb->destructor = sock_wfree;
2701 	skb_set_hash_from_sk(skb, sk);
2702 	/*
2703 	 * We used to take a refcount on sk, but following operation
2704 	 * is enough to guarantee sk_free() won't free this sock until
2705 	 * all in-flight packets are completed
2706 	 */
2707 	refcount_add(skb->truesize, &sk->sk_wmem_alloc);
2708 }
2709 EXPORT_SYMBOL(skb_set_owner_w);
2710 
2711 static bool can_skb_orphan_partial(const struct sk_buff *skb)
2712 {
2713 	/* Drivers depend on in-order delivery for crypto offload,
2714 	 * partial orphan breaks out-of-order-OK logic.
2715 	 */
2716 	if (skb_is_decrypted(skb))
2717 		return false;
2718 
2719 	return (skb->destructor == sock_wfree ||
2720 		(IS_ENABLED(CONFIG_INET) && skb->destructor == tcp_wfree));
2721 }
2722 
2723 /* This helper is used by netem, as it can hold packets in its
2724  * delay queue. We want to allow the owner socket to send more
2725  * packets, as if they were already TX completed by a typical driver.
2726  * But we also want to keep skb->sk set because some packet schedulers
2727  * rely on it (sch_fq for example).
2728  */
2729 void skb_orphan_partial(struct sk_buff *skb)
2730 {
2731 	if (skb_is_tcp_pure_ack(skb))
2732 		return;
2733 
2734 	if (can_skb_orphan_partial(skb) && skb_set_owner_sk_safe(skb, skb->sk))
2735 		return;
2736 
2737 	skb_orphan(skb);
2738 }
2739 EXPORT_SYMBOL(skb_orphan_partial);
2740 
2741 /*
2742  * Read buffer destructor automatically called from kfree_skb.
2743  */
2744 void sock_rfree(struct sk_buff *skb)
2745 {
2746 	struct sock *sk = skb->sk;
2747 	unsigned int len = skb->truesize;
2748 
2749 	atomic_sub(len, &sk->sk_rmem_alloc);
2750 	sk_mem_uncharge(sk, len);
2751 }
2752 EXPORT_SYMBOL(sock_rfree);
2753 
2754 /*
2755  * Buffer destructor for skbs that are not used directly in read or write
2756  * path, e.g. for error handler skbs. Automatically called from kfree_skb.
2757  */
2758 void sock_efree(struct sk_buff *skb)
2759 {
2760 	sock_put(skb->sk);
2761 }
2762 EXPORT_SYMBOL(sock_efree);
2763 
2764 /* Buffer destructor for prefetch/receive path where reference count may
2765  * not be held, e.g. for listen sockets.
2766  */
2767 #ifdef CONFIG_INET
2768 void sock_pfree(struct sk_buff *skb)
2769 {
2770 	struct sock *sk = skb->sk;
2771 
2772 	if (!sk_is_refcounted(sk))
2773 		return;
2774 
2775 	if (sk->sk_state == TCP_NEW_SYN_RECV && inet_reqsk(sk)->syncookie) {
2776 		inet_reqsk(sk)->rsk_listener = NULL;
2777 		reqsk_free(inet_reqsk(sk));
2778 		return;
2779 	}
2780 
2781 	sock_gen_put(sk);
2782 }
2783 EXPORT_SYMBOL(sock_pfree);
2784 #endif /* CONFIG_INET */
2785 
2786 unsigned long __sock_i_ino(struct sock *sk)
2787 {
2788 	unsigned long ino;
2789 
2790 	read_lock(&sk->sk_callback_lock);
2791 	ino = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_ino : 0;
2792 	read_unlock(&sk->sk_callback_lock);
2793 	return ino;
2794 }
2795 EXPORT_SYMBOL(__sock_i_ino);
2796 
2797 unsigned long sock_i_ino(struct sock *sk)
2798 {
2799 	unsigned long ino;
2800 
2801 	local_bh_disable();
2802 	ino = __sock_i_ino(sk);
2803 	local_bh_enable();
2804 	return ino;
2805 }
2806 EXPORT_SYMBOL(sock_i_ino);
2807 
2808 /*
2809  * Allocate a skb from the socket's send buffer.
2810  */
2811 struct sk_buff *sock_wmalloc(struct sock *sk, unsigned long size, int force,
2812 			     gfp_t priority)
2813 {
2814 	if (force ||
2815 	    refcount_read(&sk->sk_wmem_alloc) < READ_ONCE(sk->sk_sndbuf)) {
2816 		struct sk_buff *skb = alloc_skb(size, priority);
2817 
2818 		if (skb) {
2819 			skb_set_owner_w(skb, sk);
2820 			return skb;
2821 		}
2822 	}
2823 	return NULL;
2824 }
2825 EXPORT_SYMBOL(sock_wmalloc);
2826 
2827 static void sock_ofree(struct sk_buff *skb)
2828 {
2829 	struct sock *sk = skb->sk;
2830 
2831 	atomic_sub(skb->truesize, &sk->sk_omem_alloc);
2832 }
2833 
2834 struct sk_buff *sock_omalloc(struct sock *sk, unsigned long size,
2835 			     gfp_t priority)
2836 {
2837 	struct sk_buff *skb;
2838 
2839 	/* small safe race: SKB_TRUESIZE may differ from final skb->truesize */
2840 	if (atomic_read(&sk->sk_omem_alloc) + SKB_TRUESIZE(size) >
2841 	    READ_ONCE(sock_net(sk)->core.sysctl_optmem_max))
2842 		return NULL;
2843 
2844 	skb = alloc_skb(size, priority);
2845 	if (!skb)
2846 		return NULL;
2847 
2848 	atomic_add(skb->truesize, &sk->sk_omem_alloc);
2849 	skb->sk = sk;
2850 	skb->destructor = sock_ofree;
2851 	return skb;
2852 }
2853 
2854 /*
2855  * Allocate a memory block from the socket's option memory buffer.
2856  */
2857 void *sock_kmalloc(struct sock *sk, int size, gfp_t priority)
2858 {
2859 	int optmem_max = READ_ONCE(sock_net(sk)->core.sysctl_optmem_max);
2860 
2861 	if ((unsigned int)size <= optmem_max &&
2862 	    atomic_read(&sk->sk_omem_alloc) + size < optmem_max) {
2863 		void *mem;
2864 		/* First do the add, to avoid the race if kmalloc
2865 		 * might sleep.
2866 		 */
2867 		atomic_add(size, &sk->sk_omem_alloc);
2868 		mem = kmalloc(size, priority);
2869 		if (mem)
2870 			return mem;
2871 		atomic_sub(size, &sk->sk_omem_alloc);
2872 	}
2873 	return NULL;
2874 }
2875 EXPORT_SYMBOL(sock_kmalloc);
2876 
2877 /*
2878  * Duplicate the input "src" memory block using the socket's
2879  * option memory buffer.
2880  */
2881 void *sock_kmemdup(struct sock *sk, const void *src,
2882 		   int size, gfp_t priority)
2883 {
2884 	void *mem;
2885 
2886 	mem = sock_kmalloc(sk, size, priority);
2887 	if (mem)
2888 		memcpy(mem, src, size);
2889 	return mem;
2890 }
2891 EXPORT_SYMBOL(sock_kmemdup);
2892 
2893 /* Free an option memory block. Note, we actually want the inline
2894  * here as this allows gcc to detect the nullify and fold away the
2895  * condition entirely.
2896  */
2897 static inline void __sock_kfree_s(struct sock *sk, void *mem, int size,
2898 				  const bool nullify)
2899 {
2900 	if (WARN_ON_ONCE(!mem))
2901 		return;
2902 	if (nullify)
2903 		kfree_sensitive(mem);
2904 	else
2905 		kfree(mem);
2906 	atomic_sub(size, &sk->sk_omem_alloc);
2907 }
2908 
2909 void sock_kfree_s(struct sock *sk, void *mem, int size)
2910 {
2911 	__sock_kfree_s(sk, mem, size, false);
2912 }
2913 EXPORT_SYMBOL(sock_kfree_s);
2914 
2915 void sock_kzfree_s(struct sock *sk, void *mem, int size)
2916 {
2917 	__sock_kfree_s(sk, mem, size, true);
2918 }
2919 EXPORT_SYMBOL(sock_kzfree_s);
2920 
2921 /* It is almost wait_for_tcp_memory minus release_sock/lock_sock.
2922    I think, these locks should be removed for datagram sockets.
2923  */
2924 static long sock_wait_for_wmem(struct sock *sk, long timeo)
2925 {
2926 	DEFINE_WAIT(wait);
2927 
2928 	sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
2929 	for (;;) {
2930 		if (!timeo)
2931 			break;
2932 		if (signal_pending(current))
2933 			break;
2934 		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
2935 		prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
2936 		if (refcount_read(&sk->sk_wmem_alloc) < READ_ONCE(sk->sk_sndbuf))
2937 			break;
2938 		if (READ_ONCE(sk->sk_shutdown) & SEND_SHUTDOWN)
2939 			break;
2940 		if (READ_ONCE(sk->sk_err))
2941 			break;
2942 		timeo = schedule_timeout(timeo);
2943 	}
2944 	finish_wait(sk_sleep(sk), &wait);
2945 	return timeo;
2946 }
2947 
2948 
2949 /*
2950  *	Generic send/receive buffer handlers
2951  */
2952 
2953 struct sk_buff *sock_alloc_send_pskb(struct sock *sk, unsigned long header_len,
2954 				     unsigned long data_len, int noblock,
2955 				     int *errcode, int max_page_order)
2956 {
2957 	struct sk_buff *skb;
2958 	long timeo;
2959 	int err;
2960 
2961 	timeo = sock_sndtimeo(sk, noblock);
2962 	for (;;) {
2963 		err = sock_error(sk);
2964 		if (err != 0)
2965 			goto failure;
2966 
2967 		err = -EPIPE;
2968 		if (READ_ONCE(sk->sk_shutdown) & SEND_SHUTDOWN)
2969 			goto failure;
2970 
2971 		if (sk_wmem_alloc_get(sk) < READ_ONCE(sk->sk_sndbuf))
2972 			break;
2973 
2974 		sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
2975 		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
2976 		err = -EAGAIN;
2977 		if (!timeo)
2978 			goto failure;
2979 		if (signal_pending(current))
2980 			goto interrupted;
2981 		timeo = sock_wait_for_wmem(sk, timeo);
2982 	}
2983 	skb = alloc_skb_with_frags(header_len, data_len, max_page_order,
2984 				   errcode, sk->sk_allocation);
2985 	if (skb)
2986 		skb_set_owner_w(skb, sk);
2987 	return skb;
2988 
2989 interrupted:
2990 	err = sock_intr_errno(timeo);
2991 failure:
2992 	*errcode = err;
2993 	return NULL;
2994 }
2995 EXPORT_SYMBOL(sock_alloc_send_pskb);
2996 
2997 int __sock_cmsg_send(struct sock *sk, struct cmsghdr *cmsg,
2998 		     struct sockcm_cookie *sockc)
2999 {
3000 	u32 tsflags;
3001 
3002 	BUILD_BUG_ON(SOF_TIMESTAMPING_LAST == (1 << 31));
3003 
3004 	switch (cmsg->cmsg_type) {
3005 	case SO_MARK:
3006 		if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_RAW) &&
3007 		    !ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
3008 			return -EPERM;
3009 		if (cmsg->cmsg_len != CMSG_LEN(sizeof(u32)))
3010 			return -EINVAL;
3011 		sockc->mark = *(u32 *)CMSG_DATA(cmsg);
3012 		break;
3013 	case SO_TIMESTAMPING_OLD:
3014 	case SO_TIMESTAMPING_NEW:
3015 		if (cmsg->cmsg_len != CMSG_LEN(sizeof(u32)))
3016 			return -EINVAL;
3017 
3018 		tsflags = *(u32 *)CMSG_DATA(cmsg);
3019 		if (tsflags & ~SOF_TIMESTAMPING_TX_RECORD_MASK)
3020 			return -EINVAL;
3021 
3022 		sockc->tsflags &= ~SOF_TIMESTAMPING_TX_RECORD_MASK;
3023 		sockc->tsflags |= tsflags;
3024 		break;
3025 	case SCM_TXTIME:
3026 		if (!sock_flag(sk, SOCK_TXTIME))
3027 			return -EINVAL;
3028 		if (cmsg->cmsg_len != CMSG_LEN(sizeof(u64)))
3029 			return -EINVAL;
3030 		sockc->transmit_time = get_unaligned((u64 *)CMSG_DATA(cmsg));
3031 		break;
3032 	case SCM_TS_OPT_ID:
3033 		if (sk_is_tcp(sk))
3034 			return -EINVAL;
3035 		tsflags = READ_ONCE(sk->sk_tsflags);
3036 		if (!(tsflags & SOF_TIMESTAMPING_OPT_ID))
3037 			return -EINVAL;
3038 		if (cmsg->cmsg_len != CMSG_LEN(sizeof(u32)))
3039 			return -EINVAL;
3040 		sockc->ts_opt_id = *(u32 *)CMSG_DATA(cmsg);
3041 		sockc->tsflags |= SOCKCM_FLAG_TS_OPT_ID;
3042 		break;
3043 	/* SCM_RIGHTS and SCM_CREDENTIALS are semantically in SOL_UNIX. */
3044 	case SCM_RIGHTS:
3045 	case SCM_CREDENTIALS:
3046 		break;
3047 	case SO_PRIORITY:
3048 		if (cmsg->cmsg_len != CMSG_LEN(sizeof(u32)))
3049 			return -EINVAL;
3050 		if (!sk_set_prio_allowed(sk, *(u32 *)CMSG_DATA(cmsg)))
3051 			return -EPERM;
3052 		sockc->priority = *(u32 *)CMSG_DATA(cmsg);
3053 		break;
3054 	case SCM_DEVMEM_DMABUF:
3055 		if (cmsg->cmsg_len != CMSG_LEN(sizeof(u32)))
3056 			return -EINVAL;
3057 		sockc->dmabuf_id = *(u32 *)CMSG_DATA(cmsg);
3058 		break;
3059 	default:
3060 		return -EINVAL;
3061 	}
3062 	return 0;
3063 }
3064 EXPORT_SYMBOL(__sock_cmsg_send);
3065 
3066 int sock_cmsg_send(struct sock *sk, struct msghdr *msg,
3067 		   struct sockcm_cookie *sockc)
3068 {
3069 	struct cmsghdr *cmsg;
3070 	int ret;
3071 
3072 	for_each_cmsghdr(cmsg, msg) {
3073 		if (!CMSG_OK(msg, cmsg))
3074 			return -EINVAL;
3075 		if (cmsg->cmsg_level != SOL_SOCKET)
3076 			continue;
3077 		ret = __sock_cmsg_send(sk, cmsg, sockc);
3078 		if (ret)
3079 			return ret;
3080 	}
3081 	return 0;
3082 }
3083 EXPORT_SYMBOL(sock_cmsg_send);
3084 
3085 static void sk_enter_memory_pressure(struct sock *sk)
3086 {
3087 	if (!sk->sk_prot->enter_memory_pressure)
3088 		return;
3089 
3090 	sk->sk_prot->enter_memory_pressure(sk);
3091 }
3092 
3093 static void sk_leave_memory_pressure(struct sock *sk)
3094 {
3095 	if (sk->sk_prot->leave_memory_pressure) {
3096 		INDIRECT_CALL_INET_1(sk->sk_prot->leave_memory_pressure,
3097 				     tcp_leave_memory_pressure, sk);
3098 	} else {
3099 		unsigned long *memory_pressure = sk->sk_prot->memory_pressure;
3100 
3101 		if (memory_pressure && READ_ONCE(*memory_pressure))
3102 			WRITE_ONCE(*memory_pressure, 0);
3103 	}
3104 }
3105 
3106 DEFINE_STATIC_KEY_FALSE(net_high_order_alloc_disable_key);
3107 
3108 /**
3109  * skb_page_frag_refill - check that a page_frag contains enough room
3110  * @sz: minimum size of the fragment we want to get
3111  * @pfrag: pointer to page_frag
3112  * @gfp: priority for memory allocation
3113  *
3114  * Note: While this allocator tries to use high order pages, there is
3115  * no guarantee that allocations succeed. Therefore, @sz MUST be
3116  * less or equal than PAGE_SIZE.
3117  */
3118 bool skb_page_frag_refill(unsigned int sz, struct page_frag *pfrag, gfp_t gfp)
3119 {
3120 	if (pfrag->page) {
3121 		if (page_ref_count(pfrag->page) == 1) {
3122 			pfrag->offset = 0;
3123 			return true;
3124 		}
3125 		if (pfrag->offset + sz <= pfrag->size)
3126 			return true;
3127 		put_page(pfrag->page);
3128 	}
3129 
3130 	pfrag->offset = 0;
3131 	if (SKB_FRAG_PAGE_ORDER &&
3132 	    !static_branch_unlikely(&net_high_order_alloc_disable_key)) {
3133 		/* Avoid direct reclaim but allow kswapd to wake */
3134 		pfrag->page = alloc_pages((gfp & ~__GFP_DIRECT_RECLAIM) |
3135 					  __GFP_COMP | __GFP_NOWARN |
3136 					  __GFP_NORETRY,
3137 					  SKB_FRAG_PAGE_ORDER);
3138 		if (likely(pfrag->page)) {
3139 			pfrag->size = PAGE_SIZE << SKB_FRAG_PAGE_ORDER;
3140 			return true;
3141 		}
3142 	}
3143 	pfrag->page = alloc_page(gfp);
3144 	if (likely(pfrag->page)) {
3145 		pfrag->size = PAGE_SIZE;
3146 		return true;
3147 	}
3148 	return false;
3149 }
3150 EXPORT_SYMBOL(skb_page_frag_refill);
3151 
3152 bool sk_page_frag_refill(struct sock *sk, struct page_frag *pfrag)
3153 {
3154 	if (likely(skb_page_frag_refill(32U, pfrag, sk->sk_allocation)))
3155 		return true;
3156 
3157 	sk_enter_memory_pressure(sk);
3158 	sk_stream_moderate_sndbuf(sk);
3159 	return false;
3160 }
3161 EXPORT_SYMBOL(sk_page_frag_refill);
3162 
3163 void __lock_sock(struct sock *sk)
3164 	__releases(&sk->sk_lock.slock)
3165 	__acquires(&sk->sk_lock.slock)
3166 {
3167 	DEFINE_WAIT(wait);
3168 
3169 	for (;;) {
3170 		prepare_to_wait_exclusive(&sk->sk_lock.wq, &wait,
3171 					TASK_UNINTERRUPTIBLE);
3172 		spin_unlock_bh(&sk->sk_lock.slock);
3173 		schedule();
3174 		spin_lock_bh(&sk->sk_lock.slock);
3175 		if (!sock_owned_by_user(sk))
3176 			break;
3177 	}
3178 	finish_wait(&sk->sk_lock.wq, &wait);
3179 }
3180 
3181 void __release_sock(struct sock *sk)
3182 	__releases(&sk->sk_lock.slock)
3183 	__acquires(&sk->sk_lock.slock)
3184 {
3185 	struct sk_buff *skb, *next;
3186 
3187 	while ((skb = sk->sk_backlog.head) != NULL) {
3188 		sk->sk_backlog.head = sk->sk_backlog.tail = NULL;
3189 
3190 		spin_unlock_bh(&sk->sk_lock.slock);
3191 
3192 		do {
3193 			next = skb->next;
3194 			prefetch(next);
3195 			DEBUG_NET_WARN_ON_ONCE(skb_dst_is_noref(skb));
3196 			skb_mark_not_on_list(skb);
3197 			sk_backlog_rcv(sk, skb);
3198 
3199 			cond_resched();
3200 
3201 			skb = next;
3202 		} while (skb != NULL);
3203 
3204 		spin_lock_bh(&sk->sk_lock.slock);
3205 	}
3206 
3207 	/*
3208 	 * Doing the zeroing here guarantee we can not loop forever
3209 	 * while a wild producer attempts to flood us.
3210 	 */
3211 	sk->sk_backlog.len = 0;
3212 }
3213 
3214 void __sk_flush_backlog(struct sock *sk)
3215 {
3216 	spin_lock_bh(&sk->sk_lock.slock);
3217 	__release_sock(sk);
3218 
3219 	if (sk->sk_prot->release_cb)
3220 		INDIRECT_CALL_INET_1(sk->sk_prot->release_cb,
3221 				     tcp_release_cb, sk);
3222 
3223 	spin_unlock_bh(&sk->sk_lock.slock);
3224 }
3225 EXPORT_SYMBOL_GPL(__sk_flush_backlog);
3226 
3227 /**
3228  * sk_wait_data - wait for data to arrive at sk_receive_queue
3229  * @sk:    sock to wait on
3230  * @timeo: for how long
3231  * @skb:   last skb seen on sk_receive_queue
3232  *
3233  * Now socket state including sk->sk_err is changed only under lock,
3234  * hence we may omit checks after joining wait queue.
3235  * We check receive queue before schedule() only as optimization;
3236  * it is very likely that release_sock() added new data.
3237  */
3238 int sk_wait_data(struct sock *sk, long *timeo, const struct sk_buff *skb)
3239 {
3240 	DEFINE_WAIT_FUNC(wait, woken_wake_function);
3241 	int rc;
3242 
3243 	add_wait_queue(sk_sleep(sk), &wait);
3244 	sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
3245 	rc = sk_wait_event(sk, timeo, skb_peek_tail(&sk->sk_receive_queue) != skb, &wait);
3246 	sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
3247 	remove_wait_queue(sk_sleep(sk), &wait);
3248 	return rc;
3249 }
3250 EXPORT_SYMBOL(sk_wait_data);
3251 
3252 /**
3253  *	__sk_mem_raise_allocated - increase memory_allocated
3254  *	@sk: socket
3255  *	@size: memory size to allocate
3256  *	@amt: pages to allocate
3257  *	@kind: allocation type
3258  *
3259  *	Similar to __sk_mem_schedule(), but does not update sk_forward_alloc.
3260  *
3261  *	Unlike the globally shared limits among the sockets under same protocol,
3262  *	consuming the budget of a memcg won't have direct effect on other ones.
3263  *	So be optimistic about memcg's tolerance, and leave the callers to decide
3264  *	whether or not to raise allocated through sk_under_memory_pressure() or
3265  *	its variants.
3266  */
3267 int __sk_mem_raise_allocated(struct sock *sk, int size, int amt, int kind)
3268 {
3269 	bool memcg_enabled = false, charged = false;
3270 	struct proto *prot = sk->sk_prot;
3271 	long allocated;
3272 
3273 	sk_memory_allocated_add(sk, amt);
3274 	allocated = sk_memory_allocated(sk);
3275 
3276 	if (mem_cgroup_sk_enabled(sk)) {
3277 		memcg_enabled = true;
3278 		charged = mem_cgroup_sk_charge(sk, amt, gfp_memcg_charge());
3279 		if (!charged)
3280 			goto suppress_allocation;
3281 	}
3282 
3283 	/* Under limit. */
3284 	if (allocated <= sk_prot_mem_limits(sk, 0)) {
3285 		sk_leave_memory_pressure(sk);
3286 		return 1;
3287 	}
3288 
3289 	/* Under pressure. */
3290 	if (allocated > sk_prot_mem_limits(sk, 1))
3291 		sk_enter_memory_pressure(sk);
3292 
3293 	/* Over hard limit. */
3294 	if (allocated > sk_prot_mem_limits(sk, 2))
3295 		goto suppress_allocation;
3296 
3297 	/* Guarantee minimum buffer size under pressure (either global
3298 	 * or memcg) to make sure features described in RFC 7323 (TCP
3299 	 * Extensions for High Performance) work properly.
3300 	 *
3301 	 * This rule does NOT stand when exceeds global or memcg's hard
3302 	 * limit, or else a DoS attack can be taken place by spawning
3303 	 * lots of sockets whose usage are under minimum buffer size.
3304 	 */
3305 	if (kind == SK_MEM_RECV) {
3306 		if (atomic_read(&sk->sk_rmem_alloc) < sk_get_rmem0(sk, prot))
3307 			return 1;
3308 
3309 	} else { /* SK_MEM_SEND */
3310 		int wmem0 = sk_get_wmem0(sk, prot);
3311 
3312 		if (sk->sk_type == SOCK_STREAM) {
3313 			if (sk->sk_wmem_queued < wmem0)
3314 				return 1;
3315 		} else if (refcount_read(&sk->sk_wmem_alloc) < wmem0) {
3316 				return 1;
3317 		}
3318 	}
3319 
3320 	if (sk_has_memory_pressure(sk)) {
3321 		u64 alloc;
3322 
3323 		/* The following 'average' heuristic is within the
3324 		 * scope of global accounting, so it only makes
3325 		 * sense for global memory pressure.
3326 		 */
3327 		if (!sk_under_global_memory_pressure(sk))
3328 			return 1;
3329 
3330 		/* Try to be fair among all the sockets under global
3331 		 * pressure by allowing the ones that below average
3332 		 * usage to raise.
3333 		 */
3334 		alloc = sk_sockets_allocated_read_positive(sk);
3335 		if (sk_prot_mem_limits(sk, 2) > alloc *
3336 		    sk_mem_pages(sk->sk_wmem_queued +
3337 				 atomic_read(&sk->sk_rmem_alloc) +
3338 				 sk->sk_forward_alloc))
3339 			return 1;
3340 	}
3341 
3342 suppress_allocation:
3343 
3344 	if (kind == SK_MEM_SEND && sk->sk_type == SOCK_STREAM) {
3345 		sk_stream_moderate_sndbuf(sk);
3346 
3347 		/* Fail only if socket is _under_ its sndbuf.
3348 		 * In this case we cannot block, so that we have to fail.
3349 		 */
3350 		if (sk->sk_wmem_queued + size >= sk->sk_sndbuf) {
3351 			/* Force charge with __GFP_NOFAIL */
3352 			if (memcg_enabled && !charged)
3353 				mem_cgroup_sk_charge(sk, amt,
3354 						     gfp_memcg_charge() | __GFP_NOFAIL);
3355 			return 1;
3356 		}
3357 	}
3358 
3359 	trace_sock_exceed_buf_limit(sk, prot, allocated, kind);
3360 
3361 	sk_memory_allocated_sub(sk, amt);
3362 
3363 	if (charged)
3364 		mem_cgroup_sk_uncharge(sk, amt);
3365 
3366 	return 0;
3367 }
3368 
3369 /**
3370  *	__sk_mem_schedule - increase sk_forward_alloc and memory_allocated
3371  *	@sk: socket
3372  *	@size: memory size to allocate
3373  *	@kind: allocation type
3374  *
3375  *	If kind is SK_MEM_SEND, it means wmem allocation. Otherwise it means
3376  *	rmem allocation. This function assumes that protocols which have
3377  *	memory_pressure use sk_wmem_queued as write buffer accounting.
3378  */
3379 int __sk_mem_schedule(struct sock *sk, int size, int kind)
3380 {
3381 	int ret, amt = sk_mem_pages(size);
3382 
3383 	sk_forward_alloc_add(sk, amt << PAGE_SHIFT);
3384 	ret = __sk_mem_raise_allocated(sk, size, amt, kind);
3385 	if (!ret)
3386 		sk_forward_alloc_add(sk, -(amt << PAGE_SHIFT));
3387 	return ret;
3388 }
3389 EXPORT_SYMBOL(__sk_mem_schedule);
3390 
3391 /**
3392  *	__sk_mem_reduce_allocated - reclaim memory_allocated
3393  *	@sk: socket
3394  *	@amount: number of quanta
3395  *
3396  *	Similar to __sk_mem_reclaim(), but does not update sk_forward_alloc
3397  */
3398 void __sk_mem_reduce_allocated(struct sock *sk, int amount)
3399 {
3400 	sk_memory_allocated_sub(sk, amount);
3401 
3402 	if (mem_cgroup_sk_enabled(sk))
3403 		mem_cgroup_sk_uncharge(sk, amount);
3404 
3405 	if (sk_under_global_memory_pressure(sk) &&
3406 	    (sk_memory_allocated(sk) < sk_prot_mem_limits(sk, 0)))
3407 		sk_leave_memory_pressure(sk);
3408 }
3409 
3410 /**
3411  *	__sk_mem_reclaim - reclaim sk_forward_alloc and memory_allocated
3412  *	@sk: socket
3413  *	@amount: number of bytes (rounded down to a PAGE_SIZE multiple)
3414  */
3415 void __sk_mem_reclaim(struct sock *sk, int amount)
3416 {
3417 	amount >>= PAGE_SHIFT;
3418 	sk_forward_alloc_add(sk, -(amount << PAGE_SHIFT));
3419 	__sk_mem_reduce_allocated(sk, amount);
3420 }
3421 EXPORT_SYMBOL(__sk_mem_reclaim);
3422 
3423 int sk_set_peek_off(struct sock *sk, int val)
3424 {
3425 	WRITE_ONCE(sk->sk_peek_off, val);
3426 	return 0;
3427 }
3428 EXPORT_SYMBOL_GPL(sk_set_peek_off);
3429 
3430 /*
3431  * Set of default routines for initialising struct proto_ops when
3432  * the protocol does not support a particular function. In certain
3433  * cases where it makes no sense for a protocol to have a "do nothing"
3434  * function, some default processing is provided.
3435  */
3436 
3437 int sock_no_bind(struct socket *sock, struct sockaddr *saddr, int len)
3438 {
3439 	return -EOPNOTSUPP;
3440 }
3441 EXPORT_SYMBOL(sock_no_bind);
3442 
3443 int sock_no_connect(struct socket *sock, struct sockaddr *saddr,
3444 		    int len, int flags)
3445 {
3446 	return -EOPNOTSUPP;
3447 }
3448 EXPORT_SYMBOL(sock_no_connect);
3449 
3450 int sock_no_socketpair(struct socket *sock1, struct socket *sock2)
3451 {
3452 	return -EOPNOTSUPP;
3453 }
3454 EXPORT_SYMBOL(sock_no_socketpair);
3455 
3456 int sock_no_accept(struct socket *sock, struct socket *newsock,
3457 		   struct proto_accept_arg *arg)
3458 {
3459 	return -EOPNOTSUPP;
3460 }
3461 EXPORT_SYMBOL(sock_no_accept);
3462 
3463 int sock_no_getname(struct socket *sock, struct sockaddr *saddr,
3464 		    int peer)
3465 {
3466 	return -EOPNOTSUPP;
3467 }
3468 EXPORT_SYMBOL(sock_no_getname);
3469 
3470 int sock_no_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
3471 {
3472 	return -EOPNOTSUPP;
3473 }
3474 EXPORT_SYMBOL(sock_no_ioctl);
3475 
3476 int sock_no_listen(struct socket *sock, int backlog)
3477 {
3478 	return -EOPNOTSUPP;
3479 }
3480 EXPORT_SYMBOL(sock_no_listen);
3481 
3482 int sock_no_shutdown(struct socket *sock, int how)
3483 {
3484 	return -EOPNOTSUPP;
3485 }
3486 EXPORT_SYMBOL(sock_no_shutdown);
3487 
3488 int sock_no_sendmsg(struct socket *sock, struct msghdr *m, size_t len)
3489 {
3490 	return -EOPNOTSUPP;
3491 }
3492 EXPORT_SYMBOL(sock_no_sendmsg);
3493 
3494 int sock_no_sendmsg_locked(struct sock *sk, struct msghdr *m, size_t len)
3495 {
3496 	return -EOPNOTSUPP;
3497 }
3498 EXPORT_SYMBOL(sock_no_sendmsg_locked);
3499 
3500 int sock_no_recvmsg(struct socket *sock, struct msghdr *m, size_t len,
3501 		    int flags)
3502 {
3503 	return -EOPNOTSUPP;
3504 }
3505 EXPORT_SYMBOL(sock_no_recvmsg);
3506 
3507 int sock_no_mmap(struct file *file, struct socket *sock, struct vm_area_struct *vma)
3508 {
3509 	/* Mirror missing mmap method error code */
3510 	return -ENODEV;
3511 }
3512 EXPORT_SYMBOL(sock_no_mmap);
3513 
3514 /*
3515  * When a file is received (via SCM_RIGHTS, etc), we must bump the
3516  * various sock-based usage counts.
3517  */
3518 void __receive_sock(struct file *file)
3519 {
3520 	struct socket *sock;
3521 
3522 	sock = sock_from_file(file);
3523 	if (sock) {
3524 		sock_update_netprioidx(&sock->sk->sk_cgrp_data);
3525 		sock_update_classid(&sock->sk->sk_cgrp_data);
3526 	}
3527 }
3528 
3529 /*
3530  *	Default Socket Callbacks
3531  */
3532 
3533 static void sock_def_wakeup(struct sock *sk)
3534 {
3535 	struct socket_wq *wq;
3536 
3537 	rcu_read_lock();
3538 	wq = rcu_dereference(sk->sk_wq);
3539 	if (skwq_has_sleeper(wq))
3540 		wake_up_interruptible_all(&wq->wait);
3541 	rcu_read_unlock();
3542 }
3543 
3544 static void sock_def_error_report(struct sock *sk)
3545 {
3546 	struct socket_wq *wq;
3547 
3548 	rcu_read_lock();
3549 	wq = rcu_dereference(sk->sk_wq);
3550 	if (skwq_has_sleeper(wq))
3551 		wake_up_interruptible_poll(&wq->wait, EPOLLERR);
3552 	sk_wake_async_rcu(sk, SOCK_WAKE_IO, POLL_ERR);
3553 	rcu_read_unlock();
3554 }
3555 
3556 void sock_def_readable(struct sock *sk)
3557 {
3558 	struct socket_wq *wq;
3559 
3560 	trace_sk_data_ready(sk);
3561 
3562 	rcu_read_lock();
3563 	wq = rcu_dereference(sk->sk_wq);
3564 	if (skwq_has_sleeper(wq))
3565 		wake_up_interruptible_sync_poll(&wq->wait, EPOLLIN | EPOLLPRI |
3566 						EPOLLRDNORM | EPOLLRDBAND);
3567 	sk_wake_async_rcu(sk, SOCK_WAKE_WAITD, POLL_IN);
3568 	rcu_read_unlock();
3569 }
3570 
3571 static void sock_def_write_space(struct sock *sk)
3572 {
3573 	struct socket_wq *wq;
3574 
3575 	rcu_read_lock();
3576 
3577 	/* Do not wake up a writer until he can make "significant"
3578 	 * progress.  --DaveM
3579 	 */
3580 	if (sock_writeable(sk)) {
3581 		wq = rcu_dereference(sk->sk_wq);
3582 		if (skwq_has_sleeper(wq))
3583 			wake_up_interruptible_sync_poll(&wq->wait, EPOLLOUT |
3584 						EPOLLWRNORM | EPOLLWRBAND);
3585 
3586 		/* Should agree with poll, otherwise some programs break */
3587 		sk_wake_async_rcu(sk, SOCK_WAKE_SPACE, POLL_OUT);
3588 	}
3589 
3590 	rcu_read_unlock();
3591 }
3592 
3593 /* An optimised version of sock_def_write_space(), should only be called
3594  * for SOCK_RCU_FREE sockets under RCU read section and after putting
3595  * ->sk_wmem_alloc.
3596  */
3597 static void sock_def_write_space_wfree(struct sock *sk)
3598 {
3599 	/* Do not wake up a writer until he can make "significant"
3600 	 * progress.  --DaveM
3601 	 */
3602 	if (sock_writeable(sk)) {
3603 		struct socket_wq *wq = rcu_dereference(sk->sk_wq);
3604 
3605 		/* rely on refcount_sub from sock_wfree() */
3606 		smp_mb__after_atomic();
3607 		if (wq && waitqueue_active(&wq->wait))
3608 			wake_up_interruptible_sync_poll(&wq->wait, EPOLLOUT |
3609 						EPOLLWRNORM | EPOLLWRBAND);
3610 
3611 		/* Should agree with poll, otherwise some programs break */
3612 		sk_wake_async_rcu(sk, SOCK_WAKE_SPACE, POLL_OUT);
3613 	}
3614 }
3615 
3616 static void sock_def_destruct(struct sock *sk)
3617 {
3618 }
3619 
3620 void sk_send_sigurg(struct sock *sk)
3621 {
3622 	if (sk->sk_socket && sk->sk_socket->file)
3623 		if (send_sigurg(sk->sk_socket->file))
3624 			sk_wake_async(sk, SOCK_WAKE_URG, POLL_PRI);
3625 }
3626 EXPORT_SYMBOL(sk_send_sigurg);
3627 
3628 void sk_reset_timer(struct sock *sk, struct timer_list* timer,
3629 		    unsigned long expires)
3630 {
3631 	if (!mod_timer(timer, expires))
3632 		sock_hold(sk);
3633 }
3634 EXPORT_SYMBOL(sk_reset_timer);
3635 
3636 void sk_stop_timer(struct sock *sk, struct timer_list* timer)
3637 {
3638 	if (timer_delete(timer))
3639 		__sock_put(sk);
3640 }
3641 EXPORT_SYMBOL(sk_stop_timer);
3642 
3643 void sk_stop_timer_sync(struct sock *sk, struct timer_list *timer)
3644 {
3645 	if (timer_delete_sync(timer))
3646 		__sock_put(sk);
3647 }
3648 EXPORT_SYMBOL(sk_stop_timer_sync);
3649 
3650 void sock_init_data_uid(struct socket *sock, struct sock *sk, kuid_t uid)
3651 {
3652 	sk_init_common(sk);
3653 	sk->sk_send_head	=	NULL;
3654 
3655 	timer_setup(&sk->sk_timer, NULL, 0);
3656 
3657 	sk->sk_allocation	=	GFP_KERNEL;
3658 	sk->sk_rcvbuf		=	READ_ONCE(sysctl_rmem_default);
3659 	sk->sk_sndbuf		=	READ_ONCE(sysctl_wmem_default);
3660 	sk->sk_state		=	TCP_CLOSE;
3661 	sk->sk_use_task_frag	=	true;
3662 	sk_set_socket(sk, sock);
3663 
3664 	sock_set_flag(sk, SOCK_ZAPPED);
3665 
3666 	if (sock) {
3667 		sk->sk_type	=	sock->type;
3668 		RCU_INIT_POINTER(sk->sk_wq, &sock->wq);
3669 		sock->sk	=	sk;
3670 	} else {
3671 		RCU_INIT_POINTER(sk->sk_wq, NULL);
3672 	}
3673 	sk->sk_uid	=	uid;
3674 
3675 	sk->sk_state_change	=	sock_def_wakeup;
3676 	sk->sk_data_ready	=	sock_def_readable;
3677 	sk->sk_write_space	=	sock_def_write_space;
3678 	sk->sk_error_report	=	sock_def_error_report;
3679 	sk->sk_destruct		=	sock_def_destruct;
3680 
3681 	sk->sk_frag.page	=	NULL;
3682 	sk->sk_frag.offset	=	0;
3683 	sk->sk_peek_off		=	-1;
3684 
3685 	sk->sk_peer_pid 	=	NULL;
3686 	sk->sk_peer_cred	=	NULL;
3687 	spin_lock_init(&sk->sk_peer_lock);
3688 
3689 	sk->sk_write_pending	=	0;
3690 	sk->sk_rcvlowat		=	1;
3691 	sk->sk_rcvtimeo		=	MAX_SCHEDULE_TIMEOUT;
3692 	sk->sk_sndtimeo		=	MAX_SCHEDULE_TIMEOUT;
3693 
3694 	sk->sk_stamp = SK_DEFAULT_STAMP;
3695 #if BITS_PER_LONG==32
3696 	seqlock_init(&sk->sk_stamp_seq);
3697 #endif
3698 	atomic_set(&sk->sk_zckey, 0);
3699 
3700 #ifdef CONFIG_NET_RX_BUSY_POLL
3701 	sk->sk_napi_id		=	0;
3702 	sk->sk_ll_usec		=	READ_ONCE(sysctl_net_busy_read);
3703 #endif
3704 
3705 	sk->sk_max_pacing_rate = ~0UL;
3706 	sk->sk_pacing_rate = ~0UL;
3707 	WRITE_ONCE(sk->sk_pacing_shift, 10);
3708 	sk->sk_incoming_cpu = -1;
3709 
3710 	sk_rx_queue_clear(sk);
3711 	/*
3712 	 * Before updating sk_refcnt, we must commit prior changes to memory
3713 	 * (Documentation/RCU/rculist_nulls.rst for details)
3714 	 */
3715 	smp_wmb();
3716 	refcount_set(&sk->sk_refcnt, 1);
3717 	sk_drops_reset(sk);
3718 }
3719 EXPORT_SYMBOL(sock_init_data_uid);
3720 
3721 void sock_init_data(struct socket *sock, struct sock *sk)
3722 {
3723 	kuid_t uid = sock ?
3724 		SOCK_INODE(sock)->i_uid :
3725 		make_kuid(sock_net(sk)->user_ns, 0);
3726 
3727 	sock_init_data_uid(sock, sk, uid);
3728 }
3729 EXPORT_SYMBOL(sock_init_data);
3730 
3731 void lock_sock_nested(struct sock *sk, int subclass)
3732 {
3733 	/* The sk_lock has mutex_lock() semantics here. */
3734 	mutex_acquire(&sk->sk_lock.dep_map, subclass, 0, _RET_IP_);
3735 
3736 	might_sleep();
3737 	spin_lock_bh(&sk->sk_lock.slock);
3738 	if (sock_owned_by_user_nocheck(sk))
3739 		__lock_sock(sk);
3740 	sk->sk_lock.owned = 1;
3741 	spin_unlock_bh(&sk->sk_lock.slock);
3742 }
3743 EXPORT_SYMBOL(lock_sock_nested);
3744 
3745 void release_sock(struct sock *sk)
3746 {
3747 	spin_lock_bh(&sk->sk_lock.slock);
3748 	if (sk->sk_backlog.tail)
3749 		__release_sock(sk);
3750 
3751 	if (sk->sk_prot->release_cb)
3752 		INDIRECT_CALL_INET_1(sk->sk_prot->release_cb,
3753 				     tcp_release_cb, sk);
3754 
3755 	sock_release_ownership(sk);
3756 	if (waitqueue_active(&sk->sk_lock.wq))
3757 		wake_up(&sk->sk_lock.wq);
3758 	spin_unlock_bh(&sk->sk_lock.slock);
3759 }
3760 EXPORT_SYMBOL(release_sock);
3761 
3762 bool __lock_sock_fast(struct sock *sk) __acquires(&sk->sk_lock.slock)
3763 {
3764 	might_sleep();
3765 	spin_lock_bh(&sk->sk_lock.slock);
3766 
3767 	if (!sock_owned_by_user_nocheck(sk)) {
3768 		/*
3769 		 * Fast path return with bottom halves disabled and
3770 		 * sock::sk_lock.slock held.
3771 		 *
3772 		 * The 'mutex' is not contended and holding
3773 		 * sock::sk_lock.slock prevents all other lockers to
3774 		 * proceed so the corresponding unlock_sock_fast() can
3775 		 * avoid the slow path of release_sock() completely and
3776 		 * just release slock.
3777 		 *
3778 		 * From a semantical POV this is equivalent to 'acquiring'
3779 		 * the 'mutex', hence the corresponding lockdep
3780 		 * mutex_release() has to happen in the fast path of
3781 		 * unlock_sock_fast().
3782 		 */
3783 		return false;
3784 	}
3785 
3786 	__lock_sock(sk);
3787 	sk->sk_lock.owned = 1;
3788 	__acquire(&sk->sk_lock.slock);
3789 	spin_unlock_bh(&sk->sk_lock.slock);
3790 	return true;
3791 }
3792 EXPORT_SYMBOL(__lock_sock_fast);
3793 
3794 int sock_gettstamp(struct socket *sock, void __user *userstamp,
3795 		   bool timeval, bool time32)
3796 {
3797 	struct sock *sk = sock->sk;
3798 	struct timespec64 ts;
3799 
3800 	sock_enable_timestamp(sk, SOCK_TIMESTAMP);
3801 	ts = ktime_to_timespec64(sock_read_timestamp(sk));
3802 	if (ts.tv_sec == -1)
3803 		return -ENOENT;
3804 	if (ts.tv_sec == 0) {
3805 		ktime_t kt = ktime_get_real();
3806 		sock_write_timestamp(sk, kt);
3807 		ts = ktime_to_timespec64(kt);
3808 	}
3809 
3810 	if (timeval)
3811 		ts.tv_nsec /= 1000;
3812 
3813 #ifdef CONFIG_COMPAT_32BIT_TIME
3814 	if (time32)
3815 		return put_old_timespec32(&ts, userstamp);
3816 #endif
3817 #ifdef CONFIG_SPARC64
3818 	/* beware of padding in sparc64 timeval */
3819 	if (timeval && !in_compat_syscall()) {
3820 		struct __kernel_old_timeval __user tv = {
3821 			.tv_sec = ts.tv_sec,
3822 			.tv_usec = ts.tv_nsec,
3823 		};
3824 		if (copy_to_user(userstamp, &tv, sizeof(tv)))
3825 			return -EFAULT;
3826 		return 0;
3827 	}
3828 #endif
3829 	return put_timespec64(&ts, userstamp);
3830 }
3831 EXPORT_SYMBOL(sock_gettstamp);
3832 
3833 void sock_enable_timestamp(struct sock *sk, enum sock_flags flag)
3834 {
3835 	if (!sock_flag(sk, flag)) {
3836 		unsigned long previous_flags = sk->sk_flags;
3837 
3838 		sock_set_flag(sk, flag);
3839 		/*
3840 		 * we just set one of the two flags which require net
3841 		 * time stamping, but time stamping might have been on
3842 		 * already because of the other one
3843 		 */
3844 		if (sock_needs_netstamp(sk) &&
3845 		    !(previous_flags & SK_FLAGS_TIMESTAMP))
3846 			net_enable_timestamp();
3847 	}
3848 }
3849 
3850 int sock_recv_errqueue(struct sock *sk, struct msghdr *msg, int len,
3851 		       int level, int type)
3852 {
3853 	struct sock_exterr_skb *serr;
3854 	struct sk_buff *skb;
3855 	int copied, err;
3856 
3857 	err = -EAGAIN;
3858 	skb = sock_dequeue_err_skb(sk);
3859 	if (skb == NULL)
3860 		goto out;
3861 
3862 	copied = skb->len;
3863 	if (copied > len) {
3864 		msg->msg_flags |= MSG_TRUNC;
3865 		copied = len;
3866 	}
3867 	err = skb_copy_datagram_msg(skb, 0, msg, copied);
3868 	if (err)
3869 		goto out_free_skb;
3870 
3871 	sock_recv_timestamp(msg, sk, skb);
3872 
3873 	serr = SKB_EXT_ERR(skb);
3874 	put_cmsg(msg, level, type, sizeof(serr->ee), &serr->ee);
3875 
3876 	msg->msg_flags |= MSG_ERRQUEUE;
3877 	err = copied;
3878 
3879 out_free_skb:
3880 	kfree_skb(skb);
3881 out:
3882 	return err;
3883 }
3884 EXPORT_SYMBOL(sock_recv_errqueue);
3885 
3886 /*
3887  *	Get a socket option on an socket.
3888  *
3889  *	FIX: POSIX 1003.1g is very ambiguous here. It states that
3890  *	asynchronous errors should be reported by getsockopt. We assume
3891  *	this means if you specify SO_ERROR (otherwise what is the point of it).
3892  */
3893 int sock_common_getsockopt(struct socket *sock, int level, int optname,
3894 			   char __user *optval, int __user *optlen)
3895 {
3896 	struct sock *sk = sock->sk;
3897 
3898 	/* IPV6_ADDRFORM can change sk->sk_prot under us. */
3899 	return READ_ONCE(sk->sk_prot)->getsockopt(sk, level, optname, optval, optlen);
3900 }
3901 EXPORT_SYMBOL(sock_common_getsockopt);
3902 
3903 int sock_common_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
3904 			int flags)
3905 {
3906 	struct sock *sk = sock->sk;
3907 	int addr_len = 0;
3908 	int err;
3909 
3910 	err = sk->sk_prot->recvmsg(sk, msg, size, flags, &addr_len);
3911 	if (err >= 0)
3912 		msg->msg_namelen = addr_len;
3913 	return err;
3914 }
3915 EXPORT_SYMBOL(sock_common_recvmsg);
3916 
3917 /*
3918  *	Set socket options on an inet socket.
3919  */
3920 int sock_common_setsockopt(struct socket *sock, int level, int optname,
3921 			   sockptr_t optval, unsigned int optlen)
3922 {
3923 	struct sock *sk = sock->sk;
3924 
3925 	/* IPV6_ADDRFORM can change sk->sk_prot under us. */
3926 	return READ_ONCE(sk->sk_prot)->setsockopt(sk, level, optname, optval, optlen);
3927 }
3928 EXPORT_SYMBOL(sock_common_setsockopt);
3929 
3930 void sk_common_release(struct sock *sk)
3931 {
3932 	if (sk->sk_prot->destroy)
3933 		sk->sk_prot->destroy(sk);
3934 
3935 	/*
3936 	 * Observation: when sk_common_release is called, processes have
3937 	 * no access to socket. But net still has.
3938 	 * Step one, detach it from networking:
3939 	 *
3940 	 * A. Remove from hash tables.
3941 	 */
3942 
3943 	sk->sk_prot->unhash(sk);
3944 
3945 	/*
3946 	 * In this point socket cannot receive new packets, but it is possible
3947 	 * that some packets are in flight because some CPU runs receiver and
3948 	 * did hash table lookup before we unhashed socket. They will achieve
3949 	 * receive queue and will be purged by socket destructor.
3950 	 *
3951 	 * Also we still have packets pending on receive queue and probably,
3952 	 * our own packets waiting in device queues. sock_destroy will drain
3953 	 * receive queue, but transmitted packets will delay socket destruction
3954 	 * until the last reference will be released.
3955 	 */
3956 
3957 	sock_orphan(sk);
3958 
3959 	xfrm_sk_free_policy(sk);
3960 
3961 	sock_put(sk);
3962 }
3963 EXPORT_SYMBOL(sk_common_release);
3964 
3965 void sk_get_meminfo(const struct sock *sk, u32 *mem)
3966 {
3967 	memset(mem, 0, sizeof(*mem) * SK_MEMINFO_VARS);
3968 
3969 	mem[SK_MEMINFO_RMEM_ALLOC] = sk_rmem_alloc_get(sk);
3970 	mem[SK_MEMINFO_RCVBUF] = READ_ONCE(sk->sk_rcvbuf);
3971 	mem[SK_MEMINFO_WMEM_ALLOC] = sk_wmem_alloc_get(sk);
3972 	mem[SK_MEMINFO_SNDBUF] = READ_ONCE(sk->sk_sndbuf);
3973 	mem[SK_MEMINFO_FWD_ALLOC] = READ_ONCE(sk->sk_forward_alloc);
3974 	mem[SK_MEMINFO_WMEM_QUEUED] = READ_ONCE(sk->sk_wmem_queued);
3975 	mem[SK_MEMINFO_OPTMEM] = atomic_read(&sk->sk_omem_alloc);
3976 	mem[SK_MEMINFO_BACKLOG] = READ_ONCE(sk->sk_backlog.len);
3977 	mem[SK_MEMINFO_DROPS] = sk_drops_read(sk);
3978 }
3979 
3980 #ifdef CONFIG_PROC_FS
3981 static DECLARE_BITMAP(proto_inuse_idx, PROTO_INUSE_NR);
3982 
3983 int sock_prot_inuse_get(struct net *net, struct proto *prot)
3984 {
3985 	int cpu, idx = prot->inuse_idx;
3986 	int res = 0;
3987 
3988 	for_each_possible_cpu(cpu)
3989 		res += per_cpu_ptr(net->core.prot_inuse, cpu)->val[idx];
3990 
3991 	return res >= 0 ? res : 0;
3992 }
3993 EXPORT_SYMBOL_GPL(sock_prot_inuse_get);
3994 
3995 int sock_inuse_get(struct net *net)
3996 {
3997 	int cpu, res = 0;
3998 
3999 	for_each_possible_cpu(cpu)
4000 		res += per_cpu_ptr(net->core.prot_inuse, cpu)->all;
4001 
4002 	return res;
4003 }
4004 
4005 EXPORT_SYMBOL_GPL(sock_inuse_get);
4006 
4007 static int __net_init sock_inuse_init_net(struct net *net)
4008 {
4009 	net->core.prot_inuse = alloc_percpu(struct prot_inuse);
4010 	if (net->core.prot_inuse == NULL)
4011 		return -ENOMEM;
4012 	return 0;
4013 }
4014 
4015 static void __net_exit sock_inuse_exit_net(struct net *net)
4016 {
4017 	free_percpu(net->core.prot_inuse);
4018 }
4019 
4020 static struct pernet_operations net_inuse_ops = {
4021 	.init = sock_inuse_init_net,
4022 	.exit = sock_inuse_exit_net,
4023 };
4024 
4025 static __init int net_inuse_init(void)
4026 {
4027 	if (register_pernet_subsys(&net_inuse_ops))
4028 		panic("Cannot initialize net inuse counters");
4029 
4030 	return 0;
4031 }
4032 
4033 core_initcall(net_inuse_init);
4034 
4035 static int assign_proto_idx(struct proto *prot)
4036 {
4037 	prot->inuse_idx = find_first_zero_bit(proto_inuse_idx, PROTO_INUSE_NR);
4038 
4039 	if (unlikely(prot->inuse_idx == PROTO_INUSE_NR)) {
4040 		pr_err("PROTO_INUSE_NR exhausted\n");
4041 		return -ENOSPC;
4042 	}
4043 
4044 	set_bit(prot->inuse_idx, proto_inuse_idx);
4045 	return 0;
4046 }
4047 
4048 static void release_proto_idx(struct proto *prot)
4049 {
4050 	if (prot->inuse_idx != PROTO_INUSE_NR)
4051 		clear_bit(prot->inuse_idx, proto_inuse_idx);
4052 }
4053 #else
4054 static inline int assign_proto_idx(struct proto *prot)
4055 {
4056 	return 0;
4057 }
4058 
4059 static inline void release_proto_idx(struct proto *prot)
4060 {
4061 }
4062 
4063 #endif
4064 
4065 static void tw_prot_cleanup(struct timewait_sock_ops *twsk_prot)
4066 {
4067 	if (!twsk_prot)
4068 		return;
4069 	kfree(twsk_prot->twsk_slab_name);
4070 	twsk_prot->twsk_slab_name = NULL;
4071 	kmem_cache_destroy(twsk_prot->twsk_slab);
4072 	twsk_prot->twsk_slab = NULL;
4073 }
4074 
4075 static int tw_prot_init(const struct proto *prot)
4076 {
4077 	struct timewait_sock_ops *twsk_prot = prot->twsk_prot;
4078 
4079 	if (!twsk_prot)
4080 		return 0;
4081 
4082 	twsk_prot->twsk_slab_name = kasprintf(GFP_KERNEL, "tw_sock_%s",
4083 					      prot->name);
4084 	if (!twsk_prot->twsk_slab_name)
4085 		return -ENOMEM;
4086 
4087 	twsk_prot->twsk_slab =
4088 		kmem_cache_create(twsk_prot->twsk_slab_name,
4089 				  twsk_prot->twsk_obj_size, 0,
4090 				  SLAB_ACCOUNT | prot->slab_flags,
4091 				  NULL);
4092 	if (!twsk_prot->twsk_slab) {
4093 		pr_crit("%s: Can't create timewait sock SLAB cache!\n",
4094 			prot->name);
4095 		return -ENOMEM;
4096 	}
4097 
4098 	return 0;
4099 }
4100 
4101 static void req_prot_cleanup(struct request_sock_ops *rsk_prot)
4102 {
4103 	if (!rsk_prot)
4104 		return;
4105 	kfree(rsk_prot->slab_name);
4106 	rsk_prot->slab_name = NULL;
4107 	kmem_cache_destroy(rsk_prot->slab);
4108 	rsk_prot->slab = NULL;
4109 }
4110 
4111 static int req_prot_init(const struct proto *prot)
4112 {
4113 	struct request_sock_ops *rsk_prot = prot->rsk_prot;
4114 
4115 	if (!rsk_prot)
4116 		return 0;
4117 
4118 	rsk_prot->slab_name = kasprintf(GFP_KERNEL, "request_sock_%s",
4119 					prot->name);
4120 	if (!rsk_prot->slab_name)
4121 		return -ENOMEM;
4122 
4123 	rsk_prot->slab = kmem_cache_create(rsk_prot->slab_name,
4124 					   rsk_prot->obj_size, 0,
4125 					   SLAB_ACCOUNT | prot->slab_flags,
4126 					   NULL);
4127 
4128 	if (!rsk_prot->slab) {
4129 		pr_crit("%s: Can't create request sock SLAB cache!\n",
4130 			prot->name);
4131 		return -ENOMEM;
4132 	}
4133 	return 0;
4134 }
4135 
4136 int proto_register(struct proto *prot, int alloc_slab)
4137 {
4138 	int ret = -ENOBUFS;
4139 
4140 	if (prot->memory_allocated && !prot->sysctl_mem) {
4141 		pr_err("%s: missing sysctl_mem\n", prot->name);
4142 		return -EINVAL;
4143 	}
4144 	if (prot->memory_allocated && !prot->per_cpu_fw_alloc) {
4145 		pr_err("%s: missing per_cpu_fw_alloc\n", prot->name);
4146 		return -EINVAL;
4147 	}
4148 	if (alloc_slab) {
4149 		prot->slab = kmem_cache_create_usercopy(prot->name,
4150 					prot->obj_size, 0,
4151 					SLAB_HWCACHE_ALIGN | SLAB_ACCOUNT |
4152 					prot->slab_flags,
4153 					prot->useroffset, prot->usersize,
4154 					NULL);
4155 
4156 		if (prot->slab == NULL) {
4157 			pr_crit("%s: Can't create sock SLAB cache!\n",
4158 				prot->name);
4159 			goto out;
4160 		}
4161 
4162 		if (req_prot_init(prot))
4163 			goto out_free_request_sock_slab;
4164 
4165 		if (tw_prot_init(prot))
4166 			goto out_free_timewait_sock_slab;
4167 	}
4168 
4169 	mutex_lock(&proto_list_mutex);
4170 	ret = assign_proto_idx(prot);
4171 	if (ret) {
4172 		mutex_unlock(&proto_list_mutex);
4173 		goto out_free_timewait_sock_slab;
4174 	}
4175 	list_add(&prot->node, &proto_list);
4176 	mutex_unlock(&proto_list_mutex);
4177 	return ret;
4178 
4179 out_free_timewait_sock_slab:
4180 	if (alloc_slab)
4181 		tw_prot_cleanup(prot->twsk_prot);
4182 out_free_request_sock_slab:
4183 	if (alloc_slab) {
4184 		req_prot_cleanup(prot->rsk_prot);
4185 
4186 		kmem_cache_destroy(prot->slab);
4187 		prot->slab = NULL;
4188 	}
4189 out:
4190 	return ret;
4191 }
4192 EXPORT_SYMBOL(proto_register);
4193 
4194 void proto_unregister(struct proto *prot)
4195 {
4196 	mutex_lock(&proto_list_mutex);
4197 	release_proto_idx(prot);
4198 	list_del(&prot->node);
4199 	mutex_unlock(&proto_list_mutex);
4200 
4201 	kmem_cache_destroy(prot->slab);
4202 	prot->slab = NULL;
4203 
4204 	req_prot_cleanup(prot->rsk_prot);
4205 	tw_prot_cleanup(prot->twsk_prot);
4206 }
4207 EXPORT_SYMBOL(proto_unregister);
4208 
4209 int sock_load_diag_module(int family, int protocol)
4210 {
4211 	if (!protocol) {
4212 		if (!sock_is_registered(family))
4213 			return -ENOENT;
4214 
4215 		return request_module("net-pf-%d-proto-%d-type-%d", PF_NETLINK,
4216 				      NETLINK_SOCK_DIAG, family);
4217 	}
4218 
4219 #ifdef CONFIG_INET
4220 	if (family == AF_INET &&
4221 	    protocol != IPPROTO_RAW &&
4222 	    protocol < MAX_INET_PROTOS &&
4223 	    !rcu_access_pointer(inet_protos[protocol]))
4224 		return -ENOENT;
4225 #endif
4226 
4227 	return request_module("net-pf-%d-proto-%d-type-%d-%d", PF_NETLINK,
4228 			      NETLINK_SOCK_DIAG, family, protocol);
4229 }
4230 EXPORT_SYMBOL(sock_load_diag_module);
4231 
4232 #ifdef CONFIG_PROC_FS
4233 static void *proto_seq_start(struct seq_file *seq, loff_t *pos)
4234 	__acquires(proto_list_mutex)
4235 {
4236 	mutex_lock(&proto_list_mutex);
4237 	return seq_list_start_head(&proto_list, *pos);
4238 }
4239 
4240 static void *proto_seq_next(struct seq_file *seq, void *v, loff_t *pos)
4241 {
4242 	return seq_list_next(v, &proto_list, pos);
4243 }
4244 
4245 static void proto_seq_stop(struct seq_file *seq, void *v)
4246 	__releases(proto_list_mutex)
4247 {
4248 	mutex_unlock(&proto_list_mutex);
4249 }
4250 
4251 static char proto_method_implemented(const void *method)
4252 {
4253 	return method == NULL ? 'n' : 'y';
4254 }
4255 static long sock_prot_memory_allocated(struct proto *proto)
4256 {
4257 	return proto->memory_allocated != NULL ? proto_memory_allocated(proto) : -1L;
4258 }
4259 
4260 static const char *sock_prot_memory_pressure(struct proto *proto)
4261 {
4262 	return proto->memory_pressure != NULL ?
4263 	proto_memory_pressure(proto) ? "yes" : "no" : "NI";
4264 }
4265 
4266 static void proto_seq_printf(struct seq_file *seq, struct proto *proto)
4267 {
4268 
4269 	seq_printf(seq, "%-9s %4u %6d  %6ld   %-3s %6u   %-3s  %-10s "
4270 			"%2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c\n",
4271 		   proto->name,
4272 		   proto->obj_size,
4273 		   sock_prot_inuse_get(seq_file_net(seq), proto),
4274 		   sock_prot_memory_allocated(proto),
4275 		   sock_prot_memory_pressure(proto),
4276 		   proto->max_header,
4277 		   proto->slab == NULL ? "no" : "yes",
4278 		   module_name(proto->owner),
4279 		   proto_method_implemented(proto->close),
4280 		   proto_method_implemented(proto->connect),
4281 		   proto_method_implemented(proto->disconnect),
4282 		   proto_method_implemented(proto->accept),
4283 		   proto_method_implemented(proto->ioctl),
4284 		   proto_method_implemented(proto->init),
4285 		   proto_method_implemented(proto->destroy),
4286 		   proto_method_implemented(proto->shutdown),
4287 		   proto_method_implemented(proto->setsockopt),
4288 		   proto_method_implemented(proto->getsockopt),
4289 		   proto_method_implemented(proto->sendmsg),
4290 		   proto_method_implemented(proto->recvmsg),
4291 		   proto_method_implemented(proto->bind),
4292 		   proto_method_implemented(proto->backlog_rcv),
4293 		   proto_method_implemented(proto->hash),
4294 		   proto_method_implemented(proto->unhash),
4295 		   proto_method_implemented(proto->get_port),
4296 		   proto_method_implemented(proto->enter_memory_pressure));
4297 }
4298 
4299 static int proto_seq_show(struct seq_file *seq, void *v)
4300 {
4301 	if (v == &proto_list)
4302 		seq_printf(seq, "%-9s %-4s %-8s %-6s %-5s %-7s %-4s %-10s %s",
4303 			   "protocol",
4304 			   "size",
4305 			   "sockets",
4306 			   "memory",
4307 			   "press",
4308 			   "maxhdr",
4309 			   "slab",
4310 			   "module",
4311 			   "cl co di ac io in de sh ss gs se re bi br ha uh gp em\n");
4312 	else
4313 		proto_seq_printf(seq, list_entry(v, struct proto, node));
4314 	return 0;
4315 }
4316 
4317 static const struct seq_operations proto_seq_ops = {
4318 	.start  = proto_seq_start,
4319 	.next   = proto_seq_next,
4320 	.stop   = proto_seq_stop,
4321 	.show   = proto_seq_show,
4322 };
4323 
4324 static __net_init int proto_init_net(struct net *net)
4325 {
4326 	if (!proc_create_net("protocols", 0444, net->proc_net, &proto_seq_ops,
4327 			sizeof(struct seq_net_private)))
4328 		return -ENOMEM;
4329 
4330 	return 0;
4331 }
4332 
4333 static __net_exit void proto_exit_net(struct net *net)
4334 {
4335 	remove_proc_entry("protocols", net->proc_net);
4336 }
4337 
4338 
4339 static __net_initdata struct pernet_operations proto_net_ops = {
4340 	.init = proto_init_net,
4341 	.exit = proto_exit_net,
4342 };
4343 
4344 static int __init proto_init(void)
4345 {
4346 	return register_pernet_subsys(&proto_net_ops);
4347 }
4348 
4349 subsys_initcall(proto_init);
4350 
4351 #endif /* PROC_FS */
4352 
4353 #ifdef CONFIG_NET_RX_BUSY_POLL
4354 bool sk_busy_loop_end(void *p, unsigned long start_time)
4355 {
4356 	struct sock *sk = p;
4357 
4358 	if (!skb_queue_empty_lockless(&sk->sk_receive_queue))
4359 		return true;
4360 
4361 	if (sk_is_udp(sk) &&
4362 	    !skb_queue_empty_lockless(&udp_sk(sk)->reader_queue))
4363 		return true;
4364 
4365 	return sk_busy_loop_timeout(sk, start_time);
4366 }
4367 EXPORT_SYMBOL(sk_busy_loop_end);
4368 #endif /* CONFIG_NET_RX_BUSY_POLL */
4369 
4370 int sock_bind_add(struct sock *sk, struct sockaddr *addr, int addr_len)
4371 {
4372 	if (!sk->sk_prot->bind_add)
4373 		return -EOPNOTSUPP;
4374 	return sk->sk_prot->bind_add(sk, addr, addr_len);
4375 }
4376 EXPORT_SYMBOL(sock_bind_add);
4377 
4378 /* Copy 'size' bytes from userspace and return `size` back to userspace */
4379 int sock_ioctl_inout(struct sock *sk, unsigned int cmd,
4380 		     void __user *arg, void *karg, size_t size)
4381 {
4382 	int ret;
4383 
4384 	if (copy_from_user(karg, arg, size))
4385 		return -EFAULT;
4386 
4387 	ret = READ_ONCE(sk->sk_prot)->ioctl(sk, cmd, karg);
4388 	if (ret)
4389 		return ret;
4390 
4391 	if (copy_to_user(arg, karg, size))
4392 		return -EFAULT;
4393 
4394 	return 0;
4395 }
4396 EXPORT_SYMBOL(sock_ioctl_inout);
4397 
4398 /* This is the most common ioctl prep function, where the result (4 bytes) is
4399  * copied back to userspace if the ioctl() returns successfully. No input is
4400  * copied from userspace as input argument.
4401  */
4402 static int sock_ioctl_out(struct sock *sk, unsigned int cmd, void __user *arg)
4403 {
4404 	int ret, karg = 0;
4405 
4406 	ret = READ_ONCE(sk->sk_prot)->ioctl(sk, cmd, &karg);
4407 	if (ret)
4408 		return ret;
4409 
4410 	return put_user(karg, (int __user *)arg);
4411 }
4412 
4413 /* A wrapper around sock ioctls, which copies the data from userspace
4414  * (depending on the protocol/ioctl), and copies back the result to userspace.
4415  * The main motivation for this function is to pass kernel memory to the
4416  * protocol ioctl callbacks, instead of userspace memory.
4417  */
4418 int sk_ioctl(struct sock *sk, unsigned int cmd, void __user *arg)
4419 {
4420 	int rc = 1;
4421 
4422 	if (sk->sk_type == SOCK_RAW && sk->sk_family == AF_INET)
4423 		rc = ipmr_sk_ioctl(sk, cmd, arg);
4424 	else if (sk->sk_type == SOCK_RAW && sk->sk_family == AF_INET6)
4425 		rc = ip6mr_sk_ioctl(sk, cmd, arg);
4426 	else if (sk_is_phonet(sk))
4427 		rc = phonet_sk_ioctl(sk, cmd, arg);
4428 
4429 	/* If ioctl was processed, returns its value */
4430 	if (rc <= 0)
4431 		return rc;
4432 
4433 	/* Otherwise call the default handler */
4434 	return sock_ioctl_out(sk, cmd, arg);
4435 }
4436 EXPORT_SYMBOL(sk_ioctl);
4437 
4438 static int __init sock_struct_check(void)
4439 {
4440 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_rx, sk_drops);
4441 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_rx, sk_peek_off);
4442 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_rx, sk_error_queue);
4443 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_rx, sk_receive_queue);
4444 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_rx, sk_backlog);
4445 
4446 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_rx, sk_rx_dst);
4447 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_rx, sk_rx_dst_ifindex);
4448 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_rx, sk_rx_dst_cookie);
4449 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_rx, sk_rcvbuf);
4450 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_rx, sk_filter);
4451 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_rx, sk_wq);
4452 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_rx, sk_data_ready);
4453 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_rx, sk_rcvtimeo);
4454 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_rx, sk_rcvlowat);
4455 
4456 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_rxtx, sk_err);
4457 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_rxtx, sk_socket);
4458 #ifdef CONFIG_MEMCG
4459 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_rxtx, sk_memcg);
4460 #endif
4461 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_rxtx, sk_drop_counters);
4462 
4463 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_rxtx, sk_lock);
4464 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_rxtx, sk_reserved_mem);
4465 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_rxtx, sk_forward_alloc);
4466 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_rxtx, sk_tsflags);
4467 
4468 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_omem_alloc);
4469 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_omem_alloc);
4470 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_sndbuf);
4471 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_wmem_queued);
4472 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_wmem_alloc);
4473 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_tsq_flags);
4474 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_send_head);
4475 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_write_queue);
4476 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_write_pending);
4477 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_dst_pending_confirm);
4478 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_pacing_status);
4479 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_frag);
4480 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_timer);
4481 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_pacing_rate);
4482 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_zckey);
4483 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_tskey);
4484 
4485 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_max_pacing_rate);
4486 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_sndtimeo);
4487 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_priority);
4488 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_mark);
4489 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_dst_cache);
4490 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_route_caps);
4491 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_gso_type);
4492 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_gso_max_size);
4493 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_allocation);
4494 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_txhash);
4495 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_gso_max_segs);
4496 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_pacing_shift);
4497 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_use_task_frag);
4498 	return 0;
4499 }
4500 
4501 core_initcall(sock_struct_check);
4502