xref: /linux/net/core/sock.c (revision fefe5dc4afeafe896c90d5b20b605f2759343c3b)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * INET		An implementation of the TCP/IP protocol suite for the LINUX
4  *		operating system.  INET is implemented using the  BSD Socket
5  *		interface as the means of communication with the user level.
6  *
7  *		Generic socket support routines. Memory allocators, socket lock/release
8  *		handler for protocols to use and generic option handler.
9  *
10  * Authors:	Ross Biro
11  *		Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
12  *		Florian La Roche, <flla@stud.uni-sb.de>
13  *		Alan Cox, <A.Cox@swansea.ac.uk>
14  *
15  * Fixes:
16  *		Alan Cox	: 	Numerous verify_area() problems
17  *		Alan Cox	:	Connecting on a connecting socket
18  *					now returns an error for tcp.
19  *		Alan Cox	:	sock->protocol is set correctly.
20  *					and is not sometimes left as 0.
21  *		Alan Cox	:	connect handles icmp errors on a
22  *					connect properly. Unfortunately there
23  *					is a restart syscall nasty there. I
24  *					can't match BSD without hacking the C
25  *					library. Ideas urgently sought!
26  *		Alan Cox	:	Disallow bind() to addresses that are
27  *					not ours - especially broadcast ones!!
28  *		Alan Cox	:	Socket 1024 _IS_ ok for users. (fencepost)
29  *		Alan Cox	:	sock_wfree/sock_rfree don't destroy sockets,
30  *					instead they leave that for the DESTROY timer.
31  *		Alan Cox	:	Clean up error flag in accept
32  *		Alan Cox	:	TCP ack handling is buggy, the DESTROY timer
33  *					was buggy. Put a remove_sock() in the handler
34  *					for memory when we hit 0. Also altered the timer
35  *					code. The ACK stuff can wait and needs major
36  *					TCP layer surgery.
37  *		Alan Cox	:	Fixed TCP ack bug, removed remove sock
38  *					and fixed timer/inet_bh race.
39  *		Alan Cox	:	Added zapped flag for TCP
40  *		Alan Cox	:	Move kfree_skb into skbuff.c and tidied up surplus code
41  *		Alan Cox	:	for new sk_buff allocations wmalloc/rmalloc now call alloc_skb
42  *		Alan Cox	:	kfree_s calls now are kfree_skbmem so we can track skb resources
43  *		Alan Cox	:	Supports socket option broadcast now as does udp. Packet and raw need fixing.
44  *		Alan Cox	:	Added RCVBUF,SNDBUF size setting. It suddenly occurred to me how easy it was so...
45  *		Rick Sladkey	:	Relaxed UDP rules for matching packets.
46  *		C.E.Hawkins	:	IFF_PROMISC/SIOCGHWADDR support
47  *	Pauline Middelink	:	identd support
48  *		Alan Cox	:	Fixed connect() taking signals I think.
49  *		Alan Cox	:	SO_LINGER supported
50  *		Alan Cox	:	Error reporting fixes
51  *		Anonymous	:	inet_create tidied up (sk->reuse setting)
52  *		Alan Cox	:	inet sockets don't set sk->type!
53  *		Alan Cox	:	Split socket option code
54  *		Alan Cox	:	Callbacks
55  *		Alan Cox	:	Nagle flag for Charles & Johannes stuff
56  *		Alex		:	Removed restriction on inet fioctl
57  *		Alan Cox	:	Splitting INET from NET core
58  *		Alan Cox	:	Fixed bogus SO_TYPE handling in getsockopt()
59  *		Adam Caldwell	:	Missing return in SO_DONTROUTE/SO_DEBUG code
60  *		Alan Cox	:	Split IP from generic code
61  *		Alan Cox	:	New kfree_skbmem()
62  *		Alan Cox	:	Make SO_DEBUG superuser only.
63  *		Alan Cox	:	Allow anyone to clear SO_DEBUG
64  *					(compatibility fix)
65  *		Alan Cox	:	Added optimistic memory grabbing for AF_UNIX throughput.
66  *		Alan Cox	:	Allocator for a socket is settable.
67  *		Alan Cox	:	SO_ERROR includes soft errors.
68  *		Alan Cox	:	Allow NULL arguments on some SO_ opts
69  *		Alan Cox	: 	Generic socket allocation to make hooks
70  *					easier (suggested by Craig Metz).
71  *		Michael Pall	:	SO_ERROR returns positive errno again
72  *              Steve Whitehouse:       Added default destructor to free
73  *                                      protocol private data.
74  *              Steve Whitehouse:       Added various other default routines
75  *                                      common to several socket families.
76  *              Chris Evans     :       Call suser() check last on F_SETOWN
77  *		Jay Schulist	:	Added SO_ATTACH_FILTER and SO_DETACH_FILTER.
78  *		Andi Kleen	:	Add sock_kmalloc()/sock_kfree_s()
79  *		Andi Kleen	:	Fix write_space callback
80  *		Chris Evans	:	Security fixes - signedness again
81  *		Arnaldo C. Melo :       cleanups, use skb_queue_purge
82  *
83  * To Fix:
84  */
85 
86 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
87 
88 #include <asm/unaligned.h>
89 #include <linux/capability.h>
90 #include <linux/errno.h>
91 #include <linux/errqueue.h>
92 #include <linux/types.h>
93 #include <linux/socket.h>
94 #include <linux/in.h>
95 #include <linux/kernel.h>
96 #include <linux/module.h>
97 #include <linux/proc_fs.h>
98 #include <linux/seq_file.h>
99 #include <linux/sched.h>
100 #include <linux/sched/mm.h>
101 #include <linux/timer.h>
102 #include <linux/string.h>
103 #include <linux/sockios.h>
104 #include <linux/net.h>
105 #include <linux/mm.h>
106 #include <linux/slab.h>
107 #include <linux/interrupt.h>
108 #include <linux/poll.h>
109 #include <linux/tcp.h>
110 #include <linux/init.h>
111 #include <linux/highmem.h>
112 #include <linux/user_namespace.h>
113 #include <linux/static_key.h>
114 #include <linux/memcontrol.h>
115 #include <linux/prefetch.h>
116 #include <linux/compat.h>
117 #include <linux/mroute.h>
118 #include <linux/mroute6.h>
119 #include <linux/icmpv6.h>
120 
121 #include <linux/uaccess.h>
122 
123 #include <linux/netdevice.h>
124 #include <net/protocol.h>
125 #include <linux/skbuff.h>
126 #include <net/net_namespace.h>
127 #include <net/request_sock.h>
128 #include <net/sock.h>
129 #include <linux/net_tstamp.h>
130 #include <net/xfrm.h>
131 #include <linux/ipsec.h>
132 #include <net/cls_cgroup.h>
133 #include <net/netprio_cgroup.h>
134 #include <linux/sock_diag.h>
135 
136 #include <linux/filter.h>
137 #include <net/sock_reuseport.h>
138 #include <net/bpf_sk_storage.h>
139 
140 #include <trace/events/sock.h>
141 
142 #include <net/tcp.h>
143 #include <net/busy_poll.h>
144 #include <net/phonet/phonet.h>
145 
146 #include <linux/ethtool.h>
147 
148 #include "dev.h"
149 
150 static DEFINE_MUTEX(proto_list_mutex);
151 static LIST_HEAD(proto_list);
152 
153 static void sock_def_write_space_wfree(struct sock *sk);
154 static void sock_def_write_space(struct sock *sk);
155 
156 /**
157  * sk_ns_capable - General socket capability test
158  * @sk: Socket to use a capability on or through
159  * @user_ns: The user namespace of the capability to use
160  * @cap: The capability to use
161  *
162  * Test to see if the opener of the socket had when the socket was
163  * created and the current process has the capability @cap in the user
164  * namespace @user_ns.
165  */
166 bool sk_ns_capable(const struct sock *sk,
167 		   struct user_namespace *user_ns, int cap)
168 {
169 	return file_ns_capable(sk->sk_socket->file, user_ns, cap) &&
170 		ns_capable(user_ns, cap);
171 }
172 EXPORT_SYMBOL(sk_ns_capable);
173 
174 /**
175  * sk_capable - Socket global capability test
176  * @sk: Socket to use a capability on or through
177  * @cap: The global capability to use
178  *
179  * Test to see if the opener of the socket had when the socket was
180  * created and the current process has the capability @cap in all user
181  * namespaces.
182  */
183 bool sk_capable(const struct sock *sk, int cap)
184 {
185 	return sk_ns_capable(sk, &init_user_ns, cap);
186 }
187 EXPORT_SYMBOL(sk_capable);
188 
189 /**
190  * sk_net_capable - Network namespace socket capability test
191  * @sk: Socket to use a capability on or through
192  * @cap: The capability to use
193  *
194  * Test to see if the opener of the socket had when the socket was created
195  * and the current process has the capability @cap over the network namespace
196  * the socket is a member of.
197  */
198 bool sk_net_capable(const struct sock *sk, int cap)
199 {
200 	return sk_ns_capable(sk, sock_net(sk)->user_ns, cap);
201 }
202 EXPORT_SYMBOL(sk_net_capable);
203 
204 /*
205  * Each address family might have different locking rules, so we have
206  * one slock key per address family and separate keys for internal and
207  * userspace sockets.
208  */
209 static struct lock_class_key af_family_keys[AF_MAX];
210 static struct lock_class_key af_family_kern_keys[AF_MAX];
211 static struct lock_class_key af_family_slock_keys[AF_MAX];
212 static struct lock_class_key af_family_kern_slock_keys[AF_MAX];
213 
214 /*
215  * Make lock validator output more readable. (we pre-construct these
216  * strings build-time, so that runtime initialization of socket
217  * locks is fast):
218  */
219 
220 #define _sock_locks(x)						  \
221   x "AF_UNSPEC",	x "AF_UNIX"     ,	x "AF_INET"     , \
222   x "AF_AX25"  ,	x "AF_IPX"      ,	x "AF_APPLETALK", \
223   x "AF_NETROM",	x "AF_BRIDGE"   ,	x "AF_ATMPVC"   , \
224   x "AF_X25"   ,	x "AF_INET6"    ,	x "AF_ROSE"     , \
225   x "AF_DECnet",	x "AF_NETBEUI"  ,	x "AF_SECURITY" , \
226   x "AF_KEY"   ,	x "AF_NETLINK"  ,	x "AF_PACKET"   , \
227   x "AF_ASH"   ,	x "AF_ECONET"   ,	x "AF_ATMSVC"   , \
228   x "AF_RDS"   ,	x "AF_SNA"      ,	x "AF_IRDA"     , \
229   x "AF_PPPOX" ,	x "AF_WANPIPE"  ,	x "AF_LLC"      , \
230   x "27"       ,	x "28"          ,	x "AF_CAN"      , \
231   x "AF_TIPC"  ,	x "AF_BLUETOOTH",	x "IUCV"        , \
232   x "AF_RXRPC" ,	x "AF_ISDN"     ,	x "AF_PHONET"   , \
233   x "AF_IEEE802154",	x "AF_CAIF"	,	x "AF_ALG"      , \
234   x "AF_NFC"   ,	x "AF_VSOCK"    ,	x "AF_KCM"      , \
235   x "AF_QIPCRTR",	x "AF_SMC"	,	x "AF_XDP"	, \
236   x "AF_MCTP"  , \
237   x "AF_MAX"
238 
239 static const char *const af_family_key_strings[AF_MAX+1] = {
240 	_sock_locks("sk_lock-")
241 };
242 static const char *const af_family_slock_key_strings[AF_MAX+1] = {
243 	_sock_locks("slock-")
244 };
245 static const char *const af_family_clock_key_strings[AF_MAX+1] = {
246 	_sock_locks("clock-")
247 };
248 
249 static const char *const af_family_kern_key_strings[AF_MAX+1] = {
250 	_sock_locks("k-sk_lock-")
251 };
252 static const char *const af_family_kern_slock_key_strings[AF_MAX+1] = {
253 	_sock_locks("k-slock-")
254 };
255 static const char *const af_family_kern_clock_key_strings[AF_MAX+1] = {
256 	_sock_locks("k-clock-")
257 };
258 static const char *const af_family_rlock_key_strings[AF_MAX+1] = {
259 	_sock_locks("rlock-")
260 };
261 static const char *const af_family_wlock_key_strings[AF_MAX+1] = {
262 	_sock_locks("wlock-")
263 };
264 static const char *const af_family_elock_key_strings[AF_MAX+1] = {
265 	_sock_locks("elock-")
266 };
267 
268 /*
269  * sk_callback_lock and sk queues locking rules are per-address-family,
270  * so split the lock classes by using a per-AF key:
271  */
272 static struct lock_class_key af_callback_keys[AF_MAX];
273 static struct lock_class_key af_rlock_keys[AF_MAX];
274 static struct lock_class_key af_wlock_keys[AF_MAX];
275 static struct lock_class_key af_elock_keys[AF_MAX];
276 static struct lock_class_key af_kern_callback_keys[AF_MAX];
277 
278 /* Run time adjustable parameters. */
279 __u32 sysctl_wmem_max __read_mostly = SK_WMEM_MAX;
280 EXPORT_SYMBOL(sysctl_wmem_max);
281 __u32 sysctl_rmem_max __read_mostly = SK_RMEM_MAX;
282 EXPORT_SYMBOL(sysctl_rmem_max);
283 __u32 sysctl_wmem_default __read_mostly = SK_WMEM_MAX;
284 __u32 sysctl_rmem_default __read_mostly = SK_RMEM_MAX;
285 
286 /* Maximal space eaten by iovec or ancillary data plus some space */
287 int sysctl_optmem_max __read_mostly = sizeof(unsigned long)*(2*UIO_MAXIOV+512);
288 EXPORT_SYMBOL(sysctl_optmem_max);
289 
290 int sysctl_tstamp_allow_data __read_mostly = 1;
291 
292 DEFINE_STATIC_KEY_FALSE(memalloc_socks_key);
293 EXPORT_SYMBOL_GPL(memalloc_socks_key);
294 
295 /**
296  * sk_set_memalloc - sets %SOCK_MEMALLOC
297  * @sk: socket to set it on
298  *
299  * Set %SOCK_MEMALLOC on a socket for access to emergency reserves.
300  * It's the responsibility of the admin to adjust min_free_kbytes
301  * to meet the requirements
302  */
303 void sk_set_memalloc(struct sock *sk)
304 {
305 	sock_set_flag(sk, SOCK_MEMALLOC);
306 	sk->sk_allocation |= __GFP_MEMALLOC;
307 	static_branch_inc(&memalloc_socks_key);
308 }
309 EXPORT_SYMBOL_GPL(sk_set_memalloc);
310 
311 void sk_clear_memalloc(struct sock *sk)
312 {
313 	sock_reset_flag(sk, SOCK_MEMALLOC);
314 	sk->sk_allocation &= ~__GFP_MEMALLOC;
315 	static_branch_dec(&memalloc_socks_key);
316 
317 	/*
318 	 * SOCK_MEMALLOC is allowed to ignore rmem limits to ensure forward
319 	 * progress of swapping. SOCK_MEMALLOC may be cleared while
320 	 * it has rmem allocations due to the last swapfile being deactivated
321 	 * but there is a risk that the socket is unusable due to exceeding
322 	 * the rmem limits. Reclaim the reserves and obey rmem limits again.
323 	 */
324 	sk_mem_reclaim(sk);
325 }
326 EXPORT_SYMBOL_GPL(sk_clear_memalloc);
327 
328 int __sk_backlog_rcv(struct sock *sk, struct sk_buff *skb)
329 {
330 	int ret;
331 	unsigned int noreclaim_flag;
332 
333 	/* these should have been dropped before queueing */
334 	BUG_ON(!sock_flag(sk, SOCK_MEMALLOC));
335 
336 	noreclaim_flag = memalloc_noreclaim_save();
337 	ret = INDIRECT_CALL_INET(sk->sk_backlog_rcv,
338 				 tcp_v6_do_rcv,
339 				 tcp_v4_do_rcv,
340 				 sk, skb);
341 	memalloc_noreclaim_restore(noreclaim_flag);
342 
343 	return ret;
344 }
345 EXPORT_SYMBOL(__sk_backlog_rcv);
346 
347 void sk_error_report(struct sock *sk)
348 {
349 	sk->sk_error_report(sk);
350 
351 	switch (sk->sk_family) {
352 	case AF_INET:
353 		fallthrough;
354 	case AF_INET6:
355 		trace_inet_sk_error_report(sk);
356 		break;
357 	default:
358 		break;
359 	}
360 }
361 EXPORT_SYMBOL(sk_error_report);
362 
363 int sock_get_timeout(long timeo, void *optval, bool old_timeval)
364 {
365 	struct __kernel_sock_timeval tv;
366 
367 	if (timeo == MAX_SCHEDULE_TIMEOUT) {
368 		tv.tv_sec = 0;
369 		tv.tv_usec = 0;
370 	} else {
371 		tv.tv_sec = timeo / HZ;
372 		tv.tv_usec = ((timeo % HZ) * USEC_PER_SEC) / HZ;
373 	}
374 
375 	if (old_timeval && in_compat_syscall() && !COMPAT_USE_64BIT_TIME) {
376 		struct old_timeval32 tv32 = { tv.tv_sec, tv.tv_usec };
377 		*(struct old_timeval32 *)optval = tv32;
378 		return sizeof(tv32);
379 	}
380 
381 	if (old_timeval) {
382 		struct __kernel_old_timeval old_tv;
383 		old_tv.tv_sec = tv.tv_sec;
384 		old_tv.tv_usec = tv.tv_usec;
385 		*(struct __kernel_old_timeval *)optval = old_tv;
386 		return sizeof(old_tv);
387 	}
388 
389 	*(struct __kernel_sock_timeval *)optval = tv;
390 	return sizeof(tv);
391 }
392 EXPORT_SYMBOL(sock_get_timeout);
393 
394 int sock_copy_user_timeval(struct __kernel_sock_timeval *tv,
395 			   sockptr_t optval, int optlen, bool old_timeval)
396 {
397 	if (old_timeval && in_compat_syscall() && !COMPAT_USE_64BIT_TIME) {
398 		struct old_timeval32 tv32;
399 
400 		if (optlen < sizeof(tv32))
401 			return -EINVAL;
402 
403 		if (copy_from_sockptr(&tv32, optval, sizeof(tv32)))
404 			return -EFAULT;
405 		tv->tv_sec = tv32.tv_sec;
406 		tv->tv_usec = tv32.tv_usec;
407 	} else if (old_timeval) {
408 		struct __kernel_old_timeval old_tv;
409 
410 		if (optlen < sizeof(old_tv))
411 			return -EINVAL;
412 		if (copy_from_sockptr(&old_tv, optval, sizeof(old_tv)))
413 			return -EFAULT;
414 		tv->tv_sec = old_tv.tv_sec;
415 		tv->tv_usec = old_tv.tv_usec;
416 	} else {
417 		if (optlen < sizeof(*tv))
418 			return -EINVAL;
419 		if (copy_from_sockptr(tv, optval, sizeof(*tv)))
420 			return -EFAULT;
421 	}
422 
423 	return 0;
424 }
425 EXPORT_SYMBOL(sock_copy_user_timeval);
426 
427 static int sock_set_timeout(long *timeo_p, sockptr_t optval, int optlen,
428 			    bool old_timeval)
429 {
430 	struct __kernel_sock_timeval tv;
431 	int err = sock_copy_user_timeval(&tv, optval, optlen, old_timeval);
432 	long val;
433 
434 	if (err)
435 		return err;
436 
437 	if (tv.tv_usec < 0 || tv.tv_usec >= USEC_PER_SEC)
438 		return -EDOM;
439 
440 	if (tv.tv_sec < 0) {
441 		static int warned __read_mostly;
442 
443 		WRITE_ONCE(*timeo_p, 0);
444 		if (warned < 10 && net_ratelimit()) {
445 			warned++;
446 			pr_info("%s: `%s' (pid %d) tries to set negative timeout\n",
447 				__func__, current->comm, task_pid_nr(current));
448 		}
449 		return 0;
450 	}
451 	val = MAX_SCHEDULE_TIMEOUT;
452 	if ((tv.tv_sec || tv.tv_usec) &&
453 	    (tv.tv_sec < (MAX_SCHEDULE_TIMEOUT / HZ - 1)))
454 		val = tv.tv_sec * HZ + DIV_ROUND_UP((unsigned long)tv.tv_usec,
455 						    USEC_PER_SEC / HZ);
456 	WRITE_ONCE(*timeo_p, val);
457 	return 0;
458 }
459 
460 static bool sock_needs_netstamp(const struct sock *sk)
461 {
462 	switch (sk->sk_family) {
463 	case AF_UNSPEC:
464 	case AF_UNIX:
465 		return false;
466 	default:
467 		return true;
468 	}
469 }
470 
471 static void sock_disable_timestamp(struct sock *sk, unsigned long flags)
472 {
473 	if (sk->sk_flags & flags) {
474 		sk->sk_flags &= ~flags;
475 		if (sock_needs_netstamp(sk) &&
476 		    !(sk->sk_flags & SK_FLAGS_TIMESTAMP))
477 			net_disable_timestamp();
478 	}
479 }
480 
481 
482 int __sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
483 {
484 	unsigned long flags;
485 	struct sk_buff_head *list = &sk->sk_receive_queue;
486 
487 	if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf) {
488 		atomic_inc(&sk->sk_drops);
489 		trace_sock_rcvqueue_full(sk, skb);
490 		return -ENOMEM;
491 	}
492 
493 	if (!sk_rmem_schedule(sk, skb, skb->truesize)) {
494 		atomic_inc(&sk->sk_drops);
495 		return -ENOBUFS;
496 	}
497 
498 	skb->dev = NULL;
499 	skb_set_owner_r(skb, sk);
500 
501 	/* we escape from rcu protected region, make sure we dont leak
502 	 * a norefcounted dst
503 	 */
504 	skb_dst_force(skb);
505 
506 	spin_lock_irqsave(&list->lock, flags);
507 	sock_skb_set_dropcount(sk, skb);
508 	__skb_queue_tail(list, skb);
509 	spin_unlock_irqrestore(&list->lock, flags);
510 
511 	if (!sock_flag(sk, SOCK_DEAD))
512 		sk->sk_data_ready(sk);
513 	return 0;
514 }
515 EXPORT_SYMBOL(__sock_queue_rcv_skb);
516 
517 int sock_queue_rcv_skb_reason(struct sock *sk, struct sk_buff *skb,
518 			      enum skb_drop_reason *reason)
519 {
520 	enum skb_drop_reason drop_reason;
521 	int err;
522 
523 	err = sk_filter(sk, skb);
524 	if (err) {
525 		drop_reason = SKB_DROP_REASON_SOCKET_FILTER;
526 		goto out;
527 	}
528 	err = __sock_queue_rcv_skb(sk, skb);
529 	switch (err) {
530 	case -ENOMEM:
531 		drop_reason = SKB_DROP_REASON_SOCKET_RCVBUFF;
532 		break;
533 	case -ENOBUFS:
534 		drop_reason = SKB_DROP_REASON_PROTO_MEM;
535 		break;
536 	default:
537 		drop_reason = SKB_NOT_DROPPED_YET;
538 		break;
539 	}
540 out:
541 	if (reason)
542 		*reason = drop_reason;
543 	return err;
544 }
545 EXPORT_SYMBOL(sock_queue_rcv_skb_reason);
546 
547 int __sk_receive_skb(struct sock *sk, struct sk_buff *skb,
548 		     const int nested, unsigned int trim_cap, bool refcounted)
549 {
550 	int rc = NET_RX_SUCCESS;
551 
552 	if (sk_filter_trim_cap(sk, skb, trim_cap))
553 		goto discard_and_relse;
554 
555 	skb->dev = NULL;
556 
557 	if (sk_rcvqueues_full(sk, sk->sk_rcvbuf)) {
558 		atomic_inc(&sk->sk_drops);
559 		goto discard_and_relse;
560 	}
561 	if (nested)
562 		bh_lock_sock_nested(sk);
563 	else
564 		bh_lock_sock(sk);
565 	if (!sock_owned_by_user(sk)) {
566 		/*
567 		 * trylock + unlock semantics:
568 		 */
569 		mutex_acquire(&sk->sk_lock.dep_map, 0, 1, _RET_IP_);
570 
571 		rc = sk_backlog_rcv(sk, skb);
572 
573 		mutex_release(&sk->sk_lock.dep_map, _RET_IP_);
574 	} else if (sk_add_backlog(sk, skb, READ_ONCE(sk->sk_rcvbuf))) {
575 		bh_unlock_sock(sk);
576 		atomic_inc(&sk->sk_drops);
577 		goto discard_and_relse;
578 	}
579 
580 	bh_unlock_sock(sk);
581 out:
582 	if (refcounted)
583 		sock_put(sk);
584 	return rc;
585 discard_and_relse:
586 	kfree_skb(skb);
587 	goto out;
588 }
589 EXPORT_SYMBOL(__sk_receive_skb);
590 
591 INDIRECT_CALLABLE_DECLARE(struct dst_entry *ip6_dst_check(struct dst_entry *,
592 							  u32));
593 INDIRECT_CALLABLE_DECLARE(struct dst_entry *ipv4_dst_check(struct dst_entry *,
594 							   u32));
595 struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie)
596 {
597 	struct dst_entry *dst = __sk_dst_get(sk);
598 
599 	if (dst && dst->obsolete &&
600 	    INDIRECT_CALL_INET(dst->ops->check, ip6_dst_check, ipv4_dst_check,
601 			       dst, cookie) == NULL) {
602 		sk_tx_queue_clear(sk);
603 		WRITE_ONCE(sk->sk_dst_pending_confirm, 0);
604 		RCU_INIT_POINTER(sk->sk_dst_cache, NULL);
605 		dst_release(dst);
606 		return NULL;
607 	}
608 
609 	return dst;
610 }
611 EXPORT_SYMBOL(__sk_dst_check);
612 
613 struct dst_entry *sk_dst_check(struct sock *sk, u32 cookie)
614 {
615 	struct dst_entry *dst = sk_dst_get(sk);
616 
617 	if (dst && dst->obsolete &&
618 	    INDIRECT_CALL_INET(dst->ops->check, ip6_dst_check, ipv4_dst_check,
619 			       dst, cookie) == NULL) {
620 		sk_dst_reset(sk);
621 		dst_release(dst);
622 		return NULL;
623 	}
624 
625 	return dst;
626 }
627 EXPORT_SYMBOL(sk_dst_check);
628 
629 static int sock_bindtoindex_locked(struct sock *sk, int ifindex)
630 {
631 	int ret = -ENOPROTOOPT;
632 #ifdef CONFIG_NETDEVICES
633 	struct net *net = sock_net(sk);
634 
635 	/* Sorry... */
636 	ret = -EPERM;
637 	if (sk->sk_bound_dev_if && !ns_capable(net->user_ns, CAP_NET_RAW))
638 		goto out;
639 
640 	ret = -EINVAL;
641 	if (ifindex < 0)
642 		goto out;
643 
644 	/* Paired with all READ_ONCE() done locklessly. */
645 	WRITE_ONCE(sk->sk_bound_dev_if, ifindex);
646 
647 	if (sk->sk_prot->rehash)
648 		sk->sk_prot->rehash(sk);
649 	sk_dst_reset(sk);
650 
651 	ret = 0;
652 
653 out:
654 #endif
655 
656 	return ret;
657 }
658 
659 int sock_bindtoindex(struct sock *sk, int ifindex, bool lock_sk)
660 {
661 	int ret;
662 
663 	if (lock_sk)
664 		lock_sock(sk);
665 	ret = sock_bindtoindex_locked(sk, ifindex);
666 	if (lock_sk)
667 		release_sock(sk);
668 
669 	return ret;
670 }
671 EXPORT_SYMBOL(sock_bindtoindex);
672 
673 static int sock_setbindtodevice(struct sock *sk, sockptr_t optval, int optlen)
674 {
675 	int ret = -ENOPROTOOPT;
676 #ifdef CONFIG_NETDEVICES
677 	struct net *net = sock_net(sk);
678 	char devname[IFNAMSIZ];
679 	int index;
680 
681 	ret = -EINVAL;
682 	if (optlen < 0)
683 		goto out;
684 
685 	/* Bind this socket to a particular device like "eth0",
686 	 * as specified in the passed interface name. If the
687 	 * name is "" or the option length is zero the socket
688 	 * is not bound.
689 	 */
690 	if (optlen > IFNAMSIZ - 1)
691 		optlen = IFNAMSIZ - 1;
692 	memset(devname, 0, sizeof(devname));
693 
694 	ret = -EFAULT;
695 	if (copy_from_sockptr(devname, optval, optlen))
696 		goto out;
697 
698 	index = 0;
699 	if (devname[0] != '\0') {
700 		struct net_device *dev;
701 
702 		rcu_read_lock();
703 		dev = dev_get_by_name_rcu(net, devname);
704 		if (dev)
705 			index = dev->ifindex;
706 		rcu_read_unlock();
707 		ret = -ENODEV;
708 		if (!dev)
709 			goto out;
710 	}
711 
712 	sockopt_lock_sock(sk);
713 	ret = sock_bindtoindex_locked(sk, index);
714 	sockopt_release_sock(sk);
715 out:
716 #endif
717 
718 	return ret;
719 }
720 
721 static int sock_getbindtodevice(struct sock *sk, sockptr_t optval,
722 				sockptr_t optlen, int len)
723 {
724 	int ret = -ENOPROTOOPT;
725 #ifdef CONFIG_NETDEVICES
726 	int bound_dev_if = READ_ONCE(sk->sk_bound_dev_if);
727 	struct net *net = sock_net(sk);
728 	char devname[IFNAMSIZ];
729 
730 	if (bound_dev_if == 0) {
731 		len = 0;
732 		goto zero;
733 	}
734 
735 	ret = -EINVAL;
736 	if (len < IFNAMSIZ)
737 		goto out;
738 
739 	ret = netdev_get_name(net, devname, bound_dev_if);
740 	if (ret)
741 		goto out;
742 
743 	len = strlen(devname) + 1;
744 
745 	ret = -EFAULT;
746 	if (copy_to_sockptr(optval, devname, len))
747 		goto out;
748 
749 zero:
750 	ret = -EFAULT;
751 	if (copy_to_sockptr(optlen, &len, sizeof(int)))
752 		goto out;
753 
754 	ret = 0;
755 
756 out:
757 #endif
758 
759 	return ret;
760 }
761 
762 bool sk_mc_loop(const struct sock *sk)
763 {
764 	if (dev_recursion_level())
765 		return false;
766 	if (!sk)
767 		return true;
768 	/* IPV6_ADDRFORM can change sk->sk_family under us. */
769 	switch (READ_ONCE(sk->sk_family)) {
770 	case AF_INET:
771 		return inet_test_bit(MC_LOOP, sk);
772 #if IS_ENABLED(CONFIG_IPV6)
773 	case AF_INET6:
774 		return inet6_test_bit(MC6_LOOP, sk);
775 #endif
776 	}
777 	WARN_ON_ONCE(1);
778 	return true;
779 }
780 EXPORT_SYMBOL(sk_mc_loop);
781 
782 void sock_set_reuseaddr(struct sock *sk)
783 {
784 	lock_sock(sk);
785 	sk->sk_reuse = SK_CAN_REUSE;
786 	release_sock(sk);
787 }
788 EXPORT_SYMBOL(sock_set_reuseaddr);
789 
790 void sock_set_reuseport(struct sock *sk)
791 {
792 	lock_sock(sk);
793 	sk->sk_reuseport = true;
794 	release_sock(sk);
795 }
796 EXPORT_SYMBOL(sock_set_reuseport);
797 
798 void sock_no_linger(struct sock *sk)
799 {
800 	lock_sock(sk);
801 	WRITE_ONCE(sk->sk_lingertime, 0);
802 	sock_set_flag(sk, SOCK_LINGER);
803 	release_sock(sk);
804 }
805 EXPORT_SYMBOL(sock_no_linger);
806 
807 void sock_set_priority(struct sock *sk, u32 priority)
808 {
809 	WRITE_ONCE(sk->sk_priority, priority);
810 }
811 EXPORT_SYMBOL(sock_set_priority);
812 
813 void sock_set_sndtimeo(struct sock *sk, s64 secs)
814 {
815 	lock_sock(sk);
816 	if (secs && secs < MAX_SCHEDULE_TIMEOUT / HZ - 1)
817 		WRITE_ONCE(sk->sk_sndtimeo, secs * HZ);
818 	else
819 		WRITE_ONCE(sk->sk_sndtimeo, MAX_SCHEDULE_TIMEOUT);
820 	release_sock(sk);
821 }
822 EXPORT_SYMBOL(sock_set_sndtimeo);
823 
824 static void __sock_set_timestamps(struct sock *sk, bool val, bool new, bool ns)
825 {
826 	if (val)  {
827 		sock_valbool_flag(sk, SOCK_TSTAMP_NEW, new);
828 		sock_valbool_flag(sk, SOCK_RCVTSTAMPNS, ns);
829 		sock_set_flag(sk, SOCK_RCVTSTAMP);
830 		sock_enable_timestamp(sk, SOCK_TIMESTAMP);
831 	} else {
832 		sock_reset_flag(sk, SOCK_RCVTSTAMP);
833 		sock_reset_flag(sk, SOCK_RCVTSTAMPNS);
834 	}
835 }
836 
837 void sock_enable_timestamps(struct sock *sk)
838 {
839 	lock_sock(sk);
840 	__sock_set_timestamps(sk, true, false, true);
841 	release_sock(sk);
842 }
843 EXPORT_SYMBOL(sock_enable_timestamps);
844 
845 void sock_set_timestamp(struct sock *sk, int optname, bool valbool)
846 {
847 	switch (optname) {
848 	case SO_TIMESTAMP_OLD:
849 		__sock_set_timestamps(sk, valbool, false, false);
850 		break;
851 	case SO_TIMESTAMP_NEW:
852 		__sock_set_timestamps(sk, valbool, true, false);
853 		break;
854 	case SO_TIMESTAMPNS_OLD:
855 		__sock_set_timestamps(sk, valbool, false, true);
856 		break;
857 	case SO_TIMESTAMPNS_NEW:
858 		__sock_set_timestamps(sk, valbool, true, true);
859 		break;
860 	}
861 }
862 
863 static int sock_timestamping_bind_phc(struct sock *sk, int phc_index)
864 {
865 	struct net *net = sock_net(sk);
866 	struct net_device *dev = NULL;
867 	bool match = false;
868 	int *vclock_index;
869 	int i, num;
870 
871 	if (sk->sk_bound_dev_if)
872 		dev = dev_get_by_index(net, sk->sk_bound_dev_if);
873 
874 	if (!dev) {
875 		pr_err("%s: sock not bind to device\n", __func__);
876 		return -EOPNOTSUPP;
877 	}
878 
879 	num = ethtool_get_phc_vclocks(dev, &vclock_index);
880 	dev_put(dev);
881 
882 	for (i = 0; i < num; i++) {
883 		if (*(vclock_index + i) == phc_index) {
884 			match = true;
885 			break;
886 		}
887 	}
888 
889 	if (num > 0)
890 		kfree(vclock_index);
891 
892 	if (!match)
893 		return -EINVAL;
894 
895 	WRITE_ONCE(sk->sk_bind_phc, phc_index);
896 
897 	return 0;
898 }
899 
900 int sock_set_timestamping(struct sock *sk, int optname,
901 			  struct so_timestamping timestamping)
902 {
903 	int val = timestamping.flags;
904 	int ret;
905 
906 	if (val & ~SOF_TIMESTAMPING_MASK)
907 		return -EINVAL;
908 
909 	if (val & SOF_TIMESTAMPING_OPT_ID_TCP &&
910 	    !(val & SOF_TIMESTAMPING_OPT_ID))
911 		return -EINVAL;
912 
913 	if (val & SOF_TIMESTAMPING_OPT_ID &&
914 	    !(sk->sk_tsflags & SOF_TIMESTAMPING_OPT_ID)) {
915 		if (sk_is_tcp(sk)) {
916 			if ((1 << sk->sk_state) &
917 			    (TCPF_CLOSE | TCPF_LISTEN))
918 				return -EINVAL;
919 			if (val & SOF_TIMESTAMPING_OPT_ID_TCP)
920 				atomic_set(&sk->sk_tskey, tcp_sk(sk)->write_seq);
921 			else
922 				atomic_set(&sk->sk_tskey, tcp_sk(sk)->snd_una);
923 		} else {
924 			atomic_set(&sk->sk_tskey, 0);
925 		}
926 	}
927 
928 	if (val & SOF_TIMESTAMPING_OPT_STATS &&
929 	    !(val & SOF_TIMESTAMPING_OPT_TSONLY))
930 		return -EINVAL;
931 
932 	if (val & SOF_TIMESTAMPING_BIND_PHC) {
933 		ret = sock_timestamping_bind_phc(sk, timestamping.bind_phc);
934 		if (ret)
935 			return ret;
936 	}
937 
938 	WRITE_ONCE(sk->sk_tsflags, val);
939 	sock_valbool_flag(sk, SOCK_TSTAMP_NEW, optname == SO_TIMESTAMPING_NEW);
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 void sock_set_keepalive(struct sock *sk)
951 {
952 	lock_sock(sk);
953 	if (sk->sk_prot->keepalive)
954 		sk->sk_prot->keepalive(sk, true);
955 	sock_valbool_flag(sk, SOCK_KEEPOPEN, true);
956 	release_sock(sk);
957 }
958 EXPORT_SYMBOL(sock_set_keepalive);
959 
960 static void __sock_set_rcvbuf(struct sock *sk, int val)
961 {
962 	/* Ensure val * 2 fits into an int, to prevent max_t() from treating it
963 	 * as a negative value.
964 	 */
965 	val = min_t(int, val, INT_MAX / 2);
966 	sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
967 
968 	/* We double it on the way in to account for "struct sk_buff" etc.
969 	 * overhead.   Applications assume that the SO_RCVBUF setting they make
970 	 * will allow that much actual data to be received on that socket.
971 	 *
972 	 * Applications are unaware that "struct sk_buff" and other overheads
973 	 * allocate from the receive buffer during socket buffer allocation.
974 	 *
975 	 * And after considering the possible alternatives, returning the value
976 	 * we actually used in getsockopt is the most desirable behavior.
977 	 */
978 	WRITE_ONCE(sk->sk_rcvbuf, max_t(int, val * 2, SOCK_MIN_RCVBUF));
979 }
980 
981 void sock_set_rcvbuf(struct sock *sk, int val)
982 {
983 	lock_sock(sk);
984 	__sock_set_rcvbuf(sk, val);
985 	release_sock(sk);
986 }
987 EXPORT_SYMBOL(sock_set_rcvbuf);
988 
989 static void __sock_set_mark(struct sock *sk, u32 val)
990 {
991 	if (val != sk->sk_mark) {
992 		WRITE_ONCE(sk->sk_mark, val);
993 		sk_dst_reset(sk);
994 	}
995 }
996 
997 void sock_set_mark(struct sock *sk, u32 val)
998 {
999 	lock_sock(sk);
1000 	__sock_set_mark(sk, val);
1001 	release_sock(sk);
1002 }
1003 EXPORT_SYMBOL(sock_set_mark);
1004 
1005 static void sock_release_reserved_memory(struct sock *sk, int bytes)
1006 {
1007 	/* Round down bytes to multiple of pages */
1008 	bytes = round_down(bytes, PAGE_SIZE);
1009 
1010 	WARN_ON(bytes > sk->sk_reserved_mem);
1011 	WRITE_ONCE(sk->sk_reserved_mem, sk->sk_reserved_mem - bytes);
1012 	sk_mem_reclaim(sk);
1013 }
1014 
1015 static int sock_reserve_memory(struct sock *sk, int bytes)
1016 {
1017 	long allocated;
1018 	bool charged;
1019 	int pages;
1020 
1021 	if (!mem_cgroup_sockets_enabled || !sk->sk_memcg || !sk_has_account(sk))
1022 		return -EOPNOTSUPP;
1023 
1024 	if (!bytes)
1025 		return 0;
1026 
1027 	pages = sk_mem_pages(bytes);
1028 
1029 	/* pre-charge to memcg */
1030 	charged = mem_cgroup_charge_skmem(sk->sk_memcg, pages,
1031 					  GFP_KERNEL | __GFP_RETRY_MAYFAIL);
1032 	if (!charged)
1033 		return -ENOMEM;
1034 
1035 	/* pre-charge to forward_alloc */
1036 	sk_memory_allocated_add(sk, pages);
1037 	allocated = sk_memory_allocated(sk);
1038 	/* If the system goes into memory pressure with this
1039 	 * precharge, give up and return error.
1040 	 */
1041 	if (allocated > sk_prot_mem_limits(sk, 1)) {
1042 		sk_memory_allocated_sub(sk, pages);
1043 		mem_cgroup_uncharge_skmem(sk->sk_memcg, pages);
1044 		return -ENOMEM;
1045 	}
1046 	sk_forward_alloc_add(sk, pages << PAGE_SHIFT);
1047 
1048 	WRITE_ONCE(sk->sk_reserved_mem,
1049 		   sk->sk_reserved_mem + (pages << PAGE_SHIFT));
1050 
1051 	return 0;
1052 }
1053 
1054 void sockopt_lock_sock(struct sock *sk)
1055 {
1056 	/* When current->bpf_ctx is set, the setsockopt is called from
1057 	 * a bpf prog.  bpf has ensured the sk lock has been
1058 	 * acquired before calling setsockopt().
1059 	 */
1060 	if (has_current_bpf_ctx())
1061 		return;
1062 
1063 	lock_sock(sk);
1064 }
1065 EXPORT_SYMBOL(sockopt_lock_sock);
1066 
1067 void sockopt_release_sock(struct sock *sk)
1068 {
1069 	if (has_current_bpf_ctx())
1070 		return;
1071 
1072 	release_sock(sk);
1073 }
1074 EXPORT_SYMBOL(sockopt_release_sock);
1075 
1076 bool sockopt_ns_capable(struct user_namespace *ns, int cap)
1077 {
1078 	return has_current_bpf_ctx() || ns_capable(ns, cap);
1079 }
1080 EXPORT_SYMBOL(sockopt_ns_capable);
1081 
1082 bool sockopt_capable(int cap)
1083 {
1084 	return has_current_bpf_ctx() || capable(cap);
1085 }
1086 EXPORT_SYMBOL(sockopt_capable);
1087 
1088 /*
1089  *	This is meant for all protocols to use and covers goings on
1090  *	at the socket level. Everything here is generic.
1091  */
1092 
1093 int sk_setsockopt(struct sock *sk, int level, int optname,
1094 		  sockptr_t optval, unsigned int optlen)
1095 {
1096 	struct so_timestamping timestamping;
1097 	struct socket *sock = sk->sk_socket;
1098 	struct sock_txtime sk_txtime;
1099 	int val;
1100 	int valbool;
1101 	struct linger ling;
1102 	int ret = 0;
1103 
1104 	/*
1105 	 *	Options without arguments
1106 	 */
1107 
1108 	if (optname == SO_BINDTODEVICE)
1109 		return sock_setbindtodevice(sk, optval, optlen);
1110 
1111 	if (optlen < sizeof(int))
1112 		return -EINVAL;
1113 
1114 	if (copy_from_sockptr(&val, optval, sizeof(val)))
1115 		return -EFAULT;
1116 
1117 	valbool = val ? 1 : 0;
1118 
1119 	/* handle options which do not require locking the socket. */
1120 	switch (optname) {
1121 	case SO_PRIORITY:
1122 		if ((val >= 0 && val <= 6) ||
1123 		    sockopt_ns_capable(sock_net(sk)->user_ns, CAP_NET_RAW) ||
1124 		    sockopt_ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) {
1125 			sock_set_priority(sk, val);
1126 			return 0;
1127 		}
1128 		return -EPERM;
1129 	case SO_PASSSEC:
1130 		assign_bit(SOCK_PASSSEC, &sock->flags, valbool);
1131 		return 0;
1132 	case SO_PASSCRED:
1133 		assign_bit(SOCK_PASSCRED, &sock->flags, valbool);
1134 		return 0;
1135 	case SO_PASSPIDFD:
1136 		assign_bit(SOCK_PASSPIDFD, &sock->flags, valbool);
1137 		return 0;
1138 	case SO_TYPE:
1139 	case SO_PROTOCOL:
1140 	case SO_DOMAIN:
1141 	case SO_ERROR:
1142 		return -ENOPROTOOPT;
1143 #ifdef CONFIG_NET_RX_BUSY_POLL
1144 	case SO_BUSY_POLL:
1145 		if (val < 0)
1146 			return -EINVAL;
1147 		WRITE_ONCE(sk->sk_ll_usec, val);
1148 		return 0;
1149 	case SO_PREFER_BUSY_POLL:
1150 		if (valbool && !sockopt_capable(CAP_NET_ADMIN))
1151 			return -EPERM;
1152 		WRITE_ONCE(sk->sk_prefer_busy_poll, valbool);
1153 		return 0;
1154 	case SO_BUSY_POLL_BUDGET:
1155 		if (val > READ_ONCE(sk->sk_busy_poll_budget) &&
1156 		    !sockopt_capable(CAP_NET_ADMIN))
1157 			return -EPERM;
1158 		if (val < 0 || val > U16_MAX)
1159 			return -EINVAL;
1160 		WRITE_ONCE(sk->sk_busy_poll_budget, val);
1161 		return 0;
1162 #endif
1163 	case SO_MAX_PACING_RATE:
1164 		{
1165 		unsigned long ulval = (val == ~0U) ? ~0UL : (unsigned int)val;
1166 		unsigned long pacing_rate;
1167 
1168 		if (sizeof(ulval) != sizeof(val) &&
1169 		    optlen >= sizeof(ulval) &&
1170 		    copy_from_sockptr(&ulval, optval, sizeof(ulval))) {
1171 			return -EFAULT;
1172 		}
1173 		if (ulval != ~0UL)
1174 			cmpxchg(&sk->sk_pacing_status,
1175 				SK_PACING_NONE,
1176 				SK_PACING_NEEDED);
1177 		/* Pairs with READ_ONCE() from sk_getsockopt() */
1178 		WRITE_ONCE(sk->sk_max_pacing_rate, ulval);
1179 		pacing_rate = READ_ONCE(sk->sk_pacing_rate);
1180 		if (ulval < pacing_rate)
1181 			WRITE_ONCE(sk->sk_pacing_rate, ulval);
1182 		return 0;
1183 		}
1184 	case SO_TXREHASH:
1185 		if (val < -1 || val > 1)
1186 			return -EINVAL;
1187 		if ((u8)val == SOCK_TXREHASH_DEFAULT)
1188 			val = READ_ONCE(sock_net(sk)->core.sysctl_txrehash);
1189 		/* Paired with READ_ONCE() in tcp_rtx_synack()
1190 		 * and sk_getsockopt().
1191 		 */
1192 		WRITE_ONCE(sk->sk_txrehash, (u8)val);
1193 		return 0;
1194 	}
1195 
1196 	sockopt_lock_sock(sk);
1197 
1198 	switch (optname) {
1199 	case SO_DEBUG:
1200 		if (val && !sockopt_capable(CAP_NET_ADMIN))
1201 			ret = -EACCES;
1202 		else
1203 			sock_valbool_flag(sk, SOCK_DBG, valbool);
1204 		break;
1205 	case SO_REUSEADDR:
1206 		sk->sk_reuse = (valbool ? SK_CAN_REUSE : SK_NO_REUSE);
1207 		break;
1208 	case SO_REUSEPORT:
1209 		sk->sk_reuseport = valbool;
1210 		break;
1211 	case SO_DONTROUTE:
1212 		sock_valbool_flag(sk, SOCK_LOCALROUTE, valbool);
1213 		sk_dst_reset(sk);
1214 		break;
1215 	case SO_BROADCAST:
1216 		sock_valbool_flag(sk, SOCK_BROADCAST, valbool);
1217 		break;
1218 	case SO_SNDBUF:
1219 		/* Don't error on this BSD doesn't and if you think
1220 		 * about it this is right. Otherwise apps have to
1221 		 * play 'guess the biggest size' games. RCVBUF/SNDBUF
1222 		 * are treated in BSD as hints
1223 		 */
1224 		val = min_t(u32, val, READ_ONCE(sysctl_wmem_max));
1225 set_sndbuf:
1226 		/* Ensure val * 2 fits into an int, to prevent max_t()
1227 		 * from treating it as a negative value.
1228 		 */
1229 		val = min_t(int, val, INT_MAX / 2);
1230 		sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
1231 		WRITE_ONCE(sk->sk_sndbuf,
1232 			   max_t(int, val * 2, SOCK_MIN_SNDBUF));
1233 		/* Wake up sending tasks if we upped the value. */
1234 		sk->sk_write_space(sk);
1235 		break;
1236 
1237 	case SO_SNDBUFFORCE:
1238 		if (!sockopt_capable(CAP_NET_ADMIN)) {
1239 			ret = -EPERM;
1240 			break;
1241 		}
1242 
1243 		/* No negative values (to prevent underflow, as val will be
1244 		 * multiplied by 2).
1245 		 */
1246 		if (val < 0)
1247 			val = 0;
1248 		goto set_sndbuf;
1249 
1250 	case SO_RCVBUF:
1251 		/* Don't error on this BSD doesn't and if you think
1252 		 * about it this is right. Otherwise apps have to
1253 		 * play 'guess the biggest size' games. RCVBUF/SNDBUF
1254 		 * are treated in BSD as hints
1255 		 */
1256 		__sock_set_rcvbuf(sk, min_t(u32, val, READ_ONCE(sysctl_rmem_max)));
1257 		break;
1258 
1259 	case SO_RCVBUFFORCE:
1260 		if (!sockopt_capable(CAP_NET_ADMIN)) {
1261 			ret = -EPERM;
1262 			break;
1263 		}
1264 
1265 		/* No negative values (to prevent underflow, as val will be
1266 		 * multiplied by 2).
1267 		 */
1268 		__sock_set_rcvbuf(sk, max(val, 0));
1269 		break;
1270 
1271 	case SO_KEEPALIVE:
1272 		if (sk->sk_prot->keepalive)
1273 			sk->sk_prot->keepalive(sk, valbool);
1274 		sock_valbool_flag(sk, SOCK_KEEPOPEN, valbool);
1275 		break;
1276 
1277 	case SO_OOBINLINE:
1278 		sock_valbool_flag(sk, SOCK_URGINLINE, valbool);
1279 		break;
1280 
1281 	case SO_NO_CHECK:
1282 		sk->sk_no_check_tx = valbool;
1283 		break;
1284 
1285 	case SO_LINGER:
1286 		if (optlen < sizeof(ling)) {
1287 			ret = -EINVAL;	/* 1003.1g */
1288 			break;
1289 		}
1290 		if (copy_from_sockptr(&ling, optval, sizeof(ling))) {
1291 			ret = -EFAULT;
1292 			break;
1293 		}
1294 		if (!ling.l_onoff) {
1295 			sock_reset_flag(sk, SOCK_LINGER);
1296 		} else {
1297 			unsigned long t_sec = ling.l_linger;
1298 
1299 			if (t_sec >= MAX_SCHEDULE_TIMEOUT / HZ)
1300 				WRITE_ONCE(sk->sk_lingertime, MAX_SCHEDULE_TIMEOUT);
1301 			else
1302 				WRITE_ONCE(sk->sk_lingertime, t_sec * HZ);
1303 			sock_set_flag(sk, SOCK_LINGER);
1304 		}
1305 		break;
1306 
1307 	case SO_BSDCOMPAT:
1308 		break;
1309 
1310 	case SO_TIMESTAMP_OLD:
1311 	case SO_TIMESTAMP_NEW:
1312 	case SO_TIMESTAMPNS_OLD:
1313 	case SO_TIMESTAMPNS_NEW:
1314 		sock_set_timestamp(sk, optname, valbool);
1315 		break;
1316 
1317 	case SO_TIMESTAMPING_NEW:
1318 	case SO_TIMESTAMPING_OLD:
1319 		if (optlen == sizeof(timestamping)) {
1320 			if (copy_from_sockptr(&timestamping, optval,
1321 					      sizeof(timestamping))) {
1322 				ret = -EFAULT;
1323 				break;
1324 			}
1325 		} else {
1326 			memset(&timestamping, 0, sizeof(timestamping));
1327 			timestamping.flags = val;
1328 		}
1329 		ret = sock_set_timestamping(sk, optname, timestamping);
1330 		break;
1331 
1332 	case SO_RCVLOWAT:
1333 		{
1334 		int (*set_rcvlowat)(struct sock *sk, int val) = NULL;
1335 
1336 		if (val < 0)
1337 			val = INT_MAX;
1338 		if (sock)
1339 			set_rcvlowat = READ_ONCE(sock->ops)->set_rcvlowat;
1340 		if (set_rcvlowat)
1341 			ret = set_rcvlowat(sk, val);
1342 		else
1343 			WRITE_ONCE(sk->sk_rcvlowat, val ? : 1);
1344 		break;
1345 		}
1346 	case SO_RCVTIMEO_OLD:
1347 	case SO_RCVTIMEO_NEW:
1348 		ret = sock_set_timeout(&sk->sk_rcvtimeo, optval,
1349 				       optlen, optname == SO_RCVTIMEO_OLD);
1350 		break;
1351 
1352 	case SO_SNDTIMEO_OLD:
1353 	case SO_SNDTIMEO_NEW:
1354 		ret = sock_set_timeout(&sk->sk_sndtimeo, optval,
1355 				       optlen, optname == SO_SNDTIMEO_OLD);
1356 		break;
1357 
1358 	case SO_ATTACH_FILTER: {
1359 		struct sock_fprog fprog;
1360 
1361 		ret = copy_bpf_fprog_from_user(&fprog, optval, optlen);
1362 		if (!ret)
1363 			ret = sk_attach_filter(&fprog, sk);
1364 		break;
1365 	}
1366 	case SO_ATTACH_BPF:
1367 		ret = -EINVAL;
1368 		if (optlen == sizeof(u32)) {
1369 			u32 ufd;
1370 
1371 			ret = -EFAULT;
1372 			if (copy_from_sockptr(&ufd, optval, sizeof(ufd)))
1373 				break;
1374 
1375 			ret = sk_attach_bpf(ufd, sk);
1376 		}
1377 		break;
1378 
1379 	case SO_ATTACH_REUSEPORT_CBPF: {
1380 		struct sock_fprog fprog;
1381 
1382 		ret = copy_bpf_fprog_from_user(&fprog, optval, optlen);
1383 		if (!ret)
1384 			ret = sk_reuseport_attach_filter(&fprog, sk);
1385 		break;
1386 	}
1387 	case SO_ATTACH_REUSEPORT_EBPF:
1388 		ret = -EINVAL;
1389 		if (optlen == sizeof(u32)) {
1390 			u32 ufd;
1391 
1392 			ret = -EFAULT;
1393 			if (copy_from_sockptr(&ufd, optval, sizeof(ufd)))
1394 				break;
1395 
1396 			ret = sk_reuseport_attach_bpf(ufd, sk);
1397 		}
1398 		break;
1399 
1400 	case SO_DETACH_REUSEPORT_BPF:
1401 		ret = reuseport_detach_prog(sk);
1402 		break;
1403 
1404 	case SO_DETACH_FILTER:
1405 		ret = sk_detach_filter(sk);
1406 		break;
1407 
1408 	case SO_LOCK_FILTER:
1409 		if (sock_flag(sk, SOCK_FILTER_LOCKED) && !valbool)
1410 			ret = -EPERM;
1411 		else
1412 			sock_valbool_flag(sk, SOCK_FILTER_LOCKED, valbool);
1413 		break;
1414 
1415 	case SO_MARK:
1416 		if (!sockopt_ns_capable(sock_net(sk)->user_ns, CAP_NET_RAW) &&
1417 		    !sockopt_ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) {
1418 			ret = -EPERM;
1419 			break;
1420 		}
1421 
1422 		__sock_set_mark(sk, val);
1423 		break;
1424 	case SO_RCVMARK:
1425 		sock_valbool_flag(sk, SOCK_RCVMARK, valbool);
1426 		break;
1427 
1428 	case SO_RXQ_OVFL:
1429 		sock_valbool_flag(sk, SOCK_RXQ_OVFL, valbool);
1430 		break;
1431 
1432 	case SO_WIFI_STATUS:
1433 		sock_valbool_flag(sk, SOCK_WIFI_STATUS, valbool);
1434 		break;
1435 
1436 	case SO_PEEK_OFF:
1437 		{
1438 		int (*set_peek_off)(struct sock *sk, int val);
1439 
1440 		set_peek_off = READ_ONCE(sock->ops)->set_peek_off;
1441 		if (set_peek_off)
1442 			ret = set_peek_off(sk, val);
1443 		else
1444 			ret = -EOPNOTSUPP;
1445 		break;
1446 		}
1447 
1448 	case SO_NOFCS:
1449 		sock_valbool_flag(sk, SOCK_NOFCS, valbool);
1450 		break;
1451 
1452 	case SO_SELECT_ERR_QUEUE:
1453 		sock_valbool_flag(sk, SOCK_SELECT_ERR_QUEUE, valbool);
1454 		break;
1455 
1456 
1457 	case SO_INCOMING_CPU:
1458 		reuseport_update_incoming_cpu(sk, val);
1459 		break;
1460 
1461 	case SO_CNX_ADVICE:
1462 		if (val == 1)
1463 			dst_negative_advice(sk);
1464 		break;
1465 
1466 	case SO_ZEROCOPY:
1467 		if (sk->sk_family == PF_INET || sk->sk_family == PF_INET6) {
1468 			if (!(sk_is_tcp(sk) ||
1469 			      (sk->sk_type == SOCK_DGRAM &&
1470 			       sk->sk_protocol == IPPROTO_UDP)))
1471 				ret = -EOPNOTSUPP;
1472 		} else if (sk->sk_family != PF_RDS) {
1473 			ret = -EOPNOTSUPP;
1474 		}
1475 		if (!ret) {
1476 			if (val < 0 || val > 1)
1477 				ret = -EINVAL;
1478 			else
1479 				sock_valbool_flag(sk, SOCK_ZEROCOPY, valbool);
1480 		}
1481 		break;
1482 
1483 	case SO_TXTIME:
1484 		if (optlen != sizeof(struct sock_txtime)) {
1485 			ret = -EINVAL;
1486 			break;
1487 		} else if (copy_from_sockptr(&sk_txtime, optval,
1488 			   sizeof(struct sock_txtime))) {
1489 			ret = -EFAULT;
1490 			break;
1491 		} else if (sk_txtime.flags & ~SOF_TXTIME_FLAGS_MASK) {
1492 			ret = -EINVAL;
1493 			break;
1494 		}
1495 		/* CLOCK_MONOTONIC is only used by sch_fq, and this packet
1496 		 * scheduler has enough safe guards.
1497 		 */
1498 		if (sk_txtime.clockid != CLOCK_MONOTONIC &&
1499 		    !sockopt_ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) {
1500 			ret = -EPERM;
1501 			break;
1502 		}
1503 		sock_valbool_flag(sk, SOCK_TXTIME, true);
1504 		sk->sk_clockid = sk_txtime.clockid;
1505 		sk->sk_txtime_deadline_mode =
1506 			!!(sk_txtime.flags & SOF_TXTIME_DEADLINE_MODE);
1507 		sk->sk_txtime_report_errors =
1508 			!!(sk_txtime.flags & SOF_TXTIME_REPORT_ERRORS);
1509 		break;
1510 
1511 	case SO_BINDTOIFINDEX:
1512 		ret = sock_bindtoindex_locked(sk, val);
1513 		break;
1514 
1515 	case SO_BUF_LOCK:
1516 		if (val & ~SOCK_BUF_LOCK_MASK) {
1517 			ret = -EINVAL;
1518 			break;
1519 		}
1520 		sk->sk_userlocks = val | (sk->sk_userlocks &
1521 					  ~SOCK_BUF_LOCK_MASK);
1522 		break;
1523 
1524 	case SO_RESERVE_MEM:
1525 	{
1526 		int delta;
1527 
1528 		if (val < 0) {
1529 			ret = -EINVAL;
1530 			break;
1531 		}
1532 
1533 		delta = val - sk->sk_reserved_mem;
1534 		if (delta < 0)
1535 			sock_release_reserved_memory(sk, -delta);
1536 		else
1537 			ret = sock_reserve_memory(sk, delta);
1538 		break;
1539 	}
1540 
1541 	default:
1542 		ret = -ENOPROTOOPT;
1543 		break;
1544 	}
1545 	sockopt_release_sock(sk);
1546 	return ret;
1547 }
1548 
1549 int sock_setsockopt(struct socket *sock, int level, int optname,
1550 		    sockptr_t optval, unsigned int optlen)
1551 {
1552 	return sk_setsockopt(sock->sk, level, optname,
1553 			     optval, optlen);
1554 }
1555 EXPORT_SYMBOL(sock_setsockopt);
1556 
1557 static const struct cred *sk_get_peer_cred(struct sock *sk)
1558 {
1559 	const struct cred *cred;
1560 
1561 	spin_lock(&sk->sk_peer_lock);
1562 	cred = get_cred(sk->sk_peer_cred);
1563 	spin_unlock(&sk->sk_peer_lock);
1564 
1565 	return cred;
1566 }
1567 
1568 static void cred_to_ucred(struct pid *pid, const struct cred *cred,
1569 			  struct ucred *ucred)
1570 {
1571 	ucred->pid = pid_vnr(pid);
1572 	ucred->uid = ucred->gid = -1;
1573 	if (cred) {
1574 		struct user_namespace *current_ns = current_user_ns();
1575 
1576 		ucred->uid = from_kuid_munged(current_ns, cred->euid);
1577 		ucred->gid = from_kgid_munged(current_ns, cred->egid);
1578 	}
1579 }
1580 
1581 static int groups_to_user(sockptr_t dst, const struct group_info *src)
1582 {
1583 	struct user_namespace *user_ns = current_user_ns();
1584 	int i;
1585 
1586 	for (i = 0; i < src->ngroups; i++) {
1587 		gid_t gid = from_kgid_munged(user_ns, src->gid[i]);
1588 
1589 		if (copy_to_sockptr_offset(dst, i * sizeof(gid), &gid, sizeof(gid)))
1590 			return -EFAULT;
1591 	}
1592 
1593 	return 0;
1594 }
1595 
1596 int sk_getsockopt(struct sock *sk, int level, int optname,
1597 		  sockptr_t optval, sockptr_t optlen)
1598 {
1599 	struct socket *sock = sk->sk_socket;
1600 
1601 	union {
1602 		int val;
1603 		u64 val64;
1604 		unsigned long ulval;
1605 		struct linger ling;
1606 		struct old_timeval32 tm32;
1607 		struct __kernel_old_timeval tm;
1608 		struct  __kernel_sock_timeval stm;
1609 		struct sock_txtime txtime;
1610 		struct so_timestamping timestamping;
1611 	} v;
1612 
1613 	int lv = sizeof(int);
1614 	int len;
1615 
1616 	if (copy_from_sockptr(&len, optlen, sizeof(int)))
1617 		return -EFAULT;
1618 	if (len < 0)
1619 		return -EINVAL;
1620 
1621 	memset(&v, 0, sizeof(v));
1622 
1623 	switch (optname) {
1624 	case SO_DEBUG:
1625 		v.val = sock_flag(sk, SOCK_DBG);
1626 		break;
1627 
1628 	case SO_DONTROUTE:
1629 		v.val = sock_flag(sk, SOCK_LOCALROUTE);
1630 		break;
1631 
1632 	case SO_BROADCAST:
1633 		v.val = sock_flag(sk, SOCK_BROADCAST);
1634 		break;
1635 
1636 	case SO_SNDBUF:
1637 		v.val = READ_ONCE(sk->sk_sndbuf);
1638 		break;
1639 
1640 	case SO_RCVBUF:
1641 		v.val = READ_ONCE(sk->sk_rcvbuf);
1642 		break;
1643 
1644 	case SO_REUSEADDR:
1645 		v.val = sk->sk_reuse;
1646 		break;
1647 
1648 	case SO_REUSEPORT:
1649 		v.val = sk->sk_reuseport;
1650 		break;
1651 
1652 	case SO_KEEPALIVE:
1653 		v.val = sock_flag(sk, SOCK_KEEPOPEN);
1654 		break;
1655 
1656 	case SO_TYPE:
1657 		v.val = sk->sk_type;
1658 		break;
1659 
1660 	case SO_PROTOCOL:
1661 		v.val = sk->sk_protocol;
1662 		break;
1663 
1664 	case SO_DOMAIN:
1665 		v.val = sk->sk_family;
1666 		break;
1667 
1668 	case SO_ERROR:
1669 		v.val = -sock_error(sk);
1670 		if (v.val == 0)
1671 			v.val = xchg(&sk->sk_err_soft, 0);
1672 		break;
1673 
1674 	case SO_OOBINLINE:
1675 		v.val = sock_flag(sk, SOCK_URGINLINE);
1676 		break;
1677 
1678 	case SO_NO_CHECK:
1679 		v.val = sk->sk_no_check_tx;
1680 		break;
1681 
1682 	case SO_PRIORITY:
1683 		v.val = READ_ONCE(sk->sk_priority);
1684 		break;
1685 
1686 	case SO_LINGER:
1687 		lv		= sizeof(v.ling);
1688 		v.ling.l_onoff	= sock_flag(sk, SOCK_LINGER);
1689 		v.ling.l_linger	= READ_ONCE(sk->sk_lingertime) / HZ;
1690 		break;
1691 
1692 	case SO_BSDCOMPAT:
1693 		break;
1694 
1695 	case SO_TIMESTAMP_OLD:
1696 		v.val = sock_flag(sk, SOCK_RCVTSTAMP) &&
1697 				!sock_flag(sk, SOCK_TSTAMP_NEW) &&
1698 				!sock_flag(sk, SOCK_RCVTSTAMPNS);
1699 		break;
1700 
1701 	case SO_TIMESTAMPNS_OLD:
1702 		v.val = sock_flag(sk, SOCK_RCVTSTAMPNS) && !sock_flag(sk, SOCK_TSTAMP_NEW);
1703 		break;
1704 
1705 	case SO_TIMESTAMP_NEW:
1706 		v.val = sock_flag(sk, SOCK_RCVTSTAMP) && sock_flag(sk, SOCK_TSTAMP_NEW);
1707 		break;
1708 
1709 	case SO_TIMESTAMPNS_NEW:
1710 		v.val = sock_flag(sk, SOCK_RCVTSTAMPNS) && sock_flag(sk, SOCK_TSTAMP_NEW);
1711 		break;
1712 
1713 	case SO_TIMESTAMPING_OLD:
1714 		lv = sizeof(v.timestamping);
1715 		v.timestamping.flags = READ_ONCE(sk->sk_tsflags);
1716 		v.timestamping.bind_phc = READ_ONCE(sk->sk_bind_phc);
1717 		break;
1718 
1719 	case SO_RCVTIMEO_OLD:
1720 	case SO_RCVTIMEO_NEW:
1721 		lv = sock_get_timeout(READ_ONCE(sk->sk_rcvtimeo), &v,
1722 				      SO_RCVTIMEO_OLD == optname);
1723 		break;
1724 
1725 	case SO_SNDTIMEO_OLD:
1726 	case SO_SNDTIMEO_NEW:
1727 		lv = sock_get_timeout(READ_ONCE(sk->sk_sndtimeo), &v,
1728 				      SO_SNDTIMEO_OLD == optname);
1729 		break;
1730 
1731 	case SO_RCVLOWAT:
1732 		v.val = READ_ONCE(sk->sk_rcvlowat);
1733 		break;
1734 
1735 	case SO_SNDLOWAT:
1736 		v.val = 1;
1737 		break;
1738 
1739 	case SO_PASSCRED:
1740 		v.val = !!test_bit(SOCK_PASSCRED, &sock->flags);
1741 		break;
1742 
1743 	case SO_PASSPIDFD:
1744 		v.val = !!test_bit(SOCK_PASSPIDFD, &sock->flags);
1745 		break;
1746 
1747 	case SO_PEERCRED:
1748 	{
1749 		struct ucred peercred;
1750 		if (len > sizeof(peercred))
1751 			len = sizeof(peercred);
1752 
1753 		spin_lock(&sk->sk_peer_lock);
1754 		cred_to_ucred(sk->sk_peer_pid, sk->sk_peer_cred, &peercred);
1755 		spin_unlock(&sk->sk_peer_lock);
1756 
1757 		if (copy_to_sockptr(optval, &peercred, len))
1758 			return -EFAULT;
1759 		goto lenout;
1760 	}
1761 
1762 	case SO_PEERPIDFD:
1763 	{
1764 		struct pid *peer_pid;
1765 		struct file *pidfd_file = NULL;
1766 		int pidfd;
1767 
1768 		if (len > sizeof(pidfd))
1769 			len = sizeof(pidfd);
1770 
1771 		spin_lock(&sk->sk_peer_lock);
1772 		peer_pid = get_pid(sk->sk_peer_pid);
1773 		spin_unlock(&sk->sk_peer_lock);
1774 
1775 		if (!peer_pid)
1776 			return -ENODATA;
1777 
1778 		pidfd = pidfd_prepare(peer_pid, 0, &pidfd_file);
1779 		put_pid(peer_pid);
1780 		if (pidfd < 0)
1781 			return pidfd;
1782 
1783 		if (copy_to_sockptr(optval, &pidfd, len) ||
1784 		    copy_to_sockptr(optlen, &len, sizeof(int))) {
1785 			put_unused_fd(pidfd);
1786 			fput(pidfd_file);
1787 
1788 			return -EFAULT;
1789 		}
1790 
1791 		fd_install(pidfd, pidfd_file);
1792 		return 0;
1793 	}
1794 
1795 	case SO_PEERGROUPS:
1796 	{
1797 		const struct cred *cred;
1798 		int ret, n;
1799 
1800 		cred = sk_get_peer_cred(sk);
1801 		if (!cred)
1802 			return -ENODATA;
1803 
1804 		n = cred->group_info->ngroups;
1805 		if (len < n * sizeof(gid_t)) {
1806 			len = n * sizeof(gid_t);
1807 			put_cred(cred);
1808 			return copy_to_sockptr(optlen, &len, sizeof(int)) ? -EFAULT : -ERANGE;
1809 		}
1810 		len = n * sizeof(gid_t);
1811 
1812 		ret = groups_to_user(optval, cred->group_info);
1813 		put_cred(cred);
1814 		if (ret)
1815 			return ret;
1816 		goto lenout;
1817 	}
1818 
1819 	case SO_PEERNAME:
1820 	{
1821 		struct sockaddr_storage address;
1822 
1823 		lv = READ_ONCE(sock->ops)->getname(sock, (struct sockaddr *)&address, 2);
1824 		if (lv < 0)
1825 			return -ENOTCONN;
1826 		if (lv < len)
1827 			return -EINVAL;
1828 		if (copy_to_sockptr(optval, &address, len))
1829 			return -EFAULT;
1830 		goto lenout;
1831 	}
1832 
1833 	/* Dubious BSD thing... Probably nobody even uses it, but
1834 	 * the UNIX standard wants it for whatever reason... -DaveM
1835 	 */
1836 	case SO_ACCEPTCONN:
1837 		v.val = sk->sk_state == TCP_LISTEN;
1838 		break;
1839 
1840 	case SO_PASSSEC:
1841 		v.val = !!test_bit(SOCK_PASSSEC, &sock->flags);
1842 		break;
1843 
1844 	case SO_PEERSEC:
1845 		return security_socket_getpeersec_stream(sock,
1846 							 optval, optlen, len);
1847 
1848 	case SO_MARK:
1849 		v.val = READ_ONCE(sk->sk_mark);
1850 		break;
1851 
1852 	case SO_RCVMARK:
1853 		v.val = sock_flag(sk, SOCK_RCVMARK);
1854 		break;
1855 
1856 	case SO_RXQ_OVFL:
1857 		v.val = sock_flag(sk, SOCK_RXQ_OVFL);
1858 		break;
1859 
1860 	case SO_WIFI_STATUS:
1861 		v.val = sock_flag(sk, SOCK_WIFI_STATUS);
1862 		break;
1863 
1864 	case SO_PEEK_OFF:
1865 		if (!READ_ONCE(sock->ops)->set_peek_off)
1866 			return -EOPNOTSUPP;
1867 
1868 		v.val = READ_ONCE(sk->sk_peek_off);
1869 		break;
1870 	case SO_NOFCS:
1871 		v.val = sock_flag(sk, SOCK_NOFCS);
1872 		break;
1873 
1874 	case SO_BINDTODEVICE:
1875 		return sock_getbindtodevice(sk, optval, optlen, len);
1876 
1877 	case SO_GET_FILTER:
1878 		len = sk_get_filter(sk, optval, len);
1879 		if (len < 0)
1880 			return len;
1881 
1882 		goto lenout;
1883 
1884 	case SO_LOCK_FILTER:
1885 		v.val = sock_flag(sk, SOCK_FILTER_LOCKED);
1886 		break;
1887 
1888 	case SO_BPF_EXTENSIONS:
1889 		v.val = bpf_tell_extensions();
1890 		break;
1891 
1892 	case SO_SELECT_ERR_QUEUE:
1893 		v.val = sock_flag(sk, SOCK_SELECT_ERR_QUEUE);
1894 		break;
1895 
1896 #ifdef CONFIG_NET_RX_BUSY_POLL
1897 	case SO_BUSY_POLL:
1898 		v.val = READ_ONCE(sk->sk_ll_usec);
1899 		break;
1900 	case SO_PREFER_BUSY_POLL:
1901 		v.val = READ_ONCE(sk->sk_prefer_busy_poll);
1902 		break;
1903 #endif
1904 
1905 	case SO_MAX_PACING_RATE:
1906 		/* The READ_ONCE() pair with the WRITE_ONCE() in sk_setsockopt() */
1907 		if (sizeof(v.ulval) != sizeof(v.val) && len >= sizeof(v.ulval)) {
1908 			lv = sizeof(v.ulval);
1909 			v.ulval = READ_ONCE(sk->sk_max_pacing_rate);
1910 		} else {
1911 			/* 32bit version */
1912 			v.val = min_t(unsigned long, ~0U,
1913 				      READ_ONCE(sk->sk_max_pacing_rate));
1914 		}
1915 		break;
1916 
1917 	case SO_INCOMING_CPU:
1918 		v.val = READ_ONCE(sk->sk_incoming_cpu);
1919 		break;
1920 
1921 	case SO_MEMINFO:
1922 	{
1923 		u32 meminfo[SK_MEMINFO_VARS];
1924 
1925 		sk_get_meminfo(sk, meminfo);
1926 
1927 		len = min_t(unsigned int, len, sizeof(meminfo));
1928 		if (copy_to_sockptr(optval, &meminfo, len))
1929 			return -EFAULT;
1930 
1931 		goto lenout;
1932 	}
1933 
1934 #ifdef CONFIG_NET_RX_BUSY_POLL
1935 	case SO_INCOMING_NAPI_ID:
1936 		v.val = READ_ONCE(sk->sk_napi_id);
1937 
1938 		/* aggregate non-NAPI IDs down to 0 */
1939 		if (v.val < MIN_NAPI_ID)
1940 			v.val = 0;
1941 
1942 		break;
1943 #endif
1944 
1945 	case SO_COOKIE:
1946 		lv = sizeof(u64);
1947 		if (len < lv)
1948 			return -EINVAL;
1949 		v.val64 = sock_gen_cookie(sk);
1950 		break;
1951 
1952 	case SO_ZEROCOPY:
1953 		v.val = sock_flag(sk, SOCK_ZEROCOPY);
1954 		break;
1955 
1956 	case SO_TXTIME:
1957 		lv = sizeof(v.txtime);
1958 		v.txtime.clockid = sk->sk_clockid;
1959 		v.txtime.flags |= sk->sk_txtime_deadline_mode ?
1960 				  SOF_TXTIME_DEADLINE_MODE : 0;
1961 		v.txtime.flags |= sk->sk_txtime_report_errors ?
1962 				  SOF_TXTIME_REPORT_ERRORS : 0;
1963 		break;
1964 
1965 	case SO_BINDTOIFINDEX:
1966 		v.val = READ_ONCE(sk->sk_bound_dev_if);
1967 		break;
1968 
1969 	case SO_NETNS_COOKIE:
1970 		lv = sizeof(u64);
1971 		if (len != lv)
1972 			return -EINVAL;
1973 		v.val64 = sock_net(sk)->net_cookie;
1974 		break;
1975 
1976 	case SO_BUF_LOCK:
1977 		v.val = sk->sk_userlocks & SOCK_BUF_LOCK_MASK;
1978 		break;
1979 
1980 	case SO_RESERVE_MEM:
1981 		v.val = READ_ONCE(sk->sk_reserved_mem);
1982 		break;
1983 
1984 	case SO_TXREHASH:
1985 		/* Paired with WRITE_ONCE() in sk_setsockopt() */
1986 		v.val = READ_ONCE(sk->sk_txrehash);
1987 		break;
1988 
1989 	default:
1990 		/* We implement the SO_SNDLOWAT etc to not be settable
1991 		 * (1003.1g 7).
1992 		 */
1993 		return -ENOPROTOOPT;
1994 	}
1995 
1996 	if (len > lv)
1997 		len = lv;
1998 	if (copy_to_sockptr(optval, &v, len))
1999 		return -EFAULT;
2000 lenout:
2001 	if (copy_to_sockptr(optlen, &len, sizeof(int)))
2002 		return -EFAULT;
2003 	return 0;
2004 }
2005 
2006 int sock_getsockopt(struct socket *sock, int level, int optname,
2007 		    char __user *optval, int __user *optlen)
2008 {
2009 	return sk_getsockopt(sock->sk, level, optname,
2010 			     USER_SOCKPTR(optval),
2011 			     USER_SOCKPTR(optlen));
2012 }
2013 
2014 /*
2015  * Initialize an sk_lock.
2016  *
2017  * (We also register the sk_lock with the lock validator.)
2018  */
2019 static inline void sock_lock_init(struct sock *sk)
2020 {
2021 	if (sk->sk_kern_sock)
2022 		sock_lock_init_class_and_name(
2023 			sk,
2024 			af_family_kern_slock_key_strings[sk->sk_family],
2025 			af_family_kern_slock_keys + sk->sk_family,
2026 			af_family_kern_key_strings[sk->sk_family],
2027 			af_family_kern_keys + sk->sk_family);
2028 	else
2029 		sock_lock_init_class_and_name(
2030 			sk,
2031 			af_family_slock_key_strings[sk->sk_family],
2032 			af_family_slock_keys + sk->sk_family,
2033 			af_family_key_strings[sk->sk_family],
2034 			af_family_keys + sk->sk_family);
2035 }
2036 
2037 /*
2038  * Copy all fields from osk to nsk but nsk->sk_refcnt must not change yet,
2039  * even temporarly, because of RCU lookups. sk_node should also be left as is.
2040  * We must not copy fields between sk_dontcopy_begin and sk_dontcopy_end
2041  */
2042 static void sock_copy(struct sock *nsk, const struct sock *osk)
2043 {
2044 	const struct proto *prot = READ_ONCE(osk->sk_prot);
2045 #ifdef CONFIG_SECURITY_NETWORK
2046 	void *sptr = nsk->sk_security;
2047 #endif
2048 
2049 	/* If we move sk_tx_queue_mapping out of the private section,
2050 	 * we must check if sk_tx_queue_clear() is called after
2051 	 * sock_copy() in sk_clone_lock().
2052 	 */
2053 	BUILD_BUG_ON(offsetof(struct sock, sk_tx_queue_mapping) <
2054 		     offsetof(struct sock, sk_dontcopy_begin) ||
2055 		     offsetof(struct sock, sk_tx_queue_mapping) >=
2056 		     offsetof(struct sock, sk_dontcopy_end));
2057 
2058 	memcpy(nsk, osk, offsetof(struct sock, sk_dontcopy_begin));
2059 
2060 	memcpy(&nsk->sk_dontcopy_end, &osk->sk_dontcopy_end,
2061 	       prot->obj_size - offsetof(struct sock, sk_dontcopy_end));
2062 
2063 #ifdef CONFIG_SECURITY_NETWORK
2064 	nsk->sk_security = sptr;
2065 	security_sk_clone(osk, nsk);
2066 #endif
2067 }
2068 
2069 static struct sock *sk_prot_alloc(struct proto *prot, gfp_t priority,
2070 		int family)
2071 {
2072 	struct sock *sk;
2073 	struct kmem_cache *slab;
2074 
2075 	slab = prot->slab;
2076 	if (slab != NULL) {
2077 		sk = kmem_cache_alloc(slab, priority & ~__GFP_ZERO);
2078 		if (!sk)
2079 			return sk;
2080 		if (want_init_on_alloc(priority))
2081 			sk_prot_clear_nulls(sk, prot->obj_size);
2082 	} else
2083 		sk = kmalloc(prot->obj_size, priority);
2084 
2085 	if (sk != NULL) {
2086 		if (security_sk_alloc(sk, family, priority))
2087 			goto out_free;
2088 
2089 		if (!try_module_get(prot->owner))
2090 			goto out_free_sec;
2091 	}
2092 
2093 	return sk;
2094 
2095 out_free_sec:
2096 	security_sk_free(sk);
2097 out_free:
2098 	if (slab != NULL)
2099 		kmem_cache_free(slab, sk);
2100 	else
2101 		kfree(sk);
2102 	return NULL;
2103 }
2104 
2105 static void sk_prot_free(struct proto *prot, struct sock *sk)
2106 {
2107 	struct kmem_cache *slab;
2108 	struct module *owner;
2109 
2110 	owner = prot->owner;
2111 	slab = prot->slab;
2112 
2113 	cgroup_sk_free(&sk->sk_cgrp_data);
2114 	mem_cgroup_sk_free(sk);
2115 	security_sk_free(sk);
2116 	if (slab != NULL)
2117 		kmem_cache_free(slab, sk);
2118 	else
2119 		kfree(sk);
2120 	module_put(owner);
2121 }
2122 
2123 /**
2124  *	sk_alloc - All socket objects are allocated here
2125  *	@net: the applicable net namespace
2126  *	@family: protocol family
2127  *	@priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
2128  *	@prot: struct proto associated with this new sock instance
2129  *	@kern: is this to be a kernel socket?
2130  */
2131 struct sock *sk_alloc(struct net *net, int family, gfp_t priority,
2132 		      struct proto *prot, int kern)
2133 {
2134 	struct sock *sk;
2135 
2136 	sk = sk_prot_alloc(prot, priority | __GFP_ZERO, family);
2137 	if (sk) {
2138 		sk->sk_family = family;
2139 		/*
2140 		 * See comment in struct sock definition to understand
2141 		 * why we need sk_prot_creator -acme
2142 		 */
2143 		sk->sk_prot = sk->sk_prot_creator = prot;
2144 		sk->sk_kern_sock = kern;
2145 		sock_lock_init(sk);
2146 		sk->sk_net_refcnt = kern ? 0 : 1;
2147 		if (likely(sk->sk_net_refcnt)) {
2148 			get_net_track(net, &sk->ns_tracker, priority);
2149 			sock_inuse_add(net, 1);
2150 		} else {
2151 			__netns_tracker_alloc(net, &sk->ns_tracker,
2152 					      false, priority);
2153 		}
2154 
2155 		sock_net_set(sk, net);
2156 		refcount_set(&sk->sk_wmem_alloc, 1);
2157 
2158 		mem_cgroup_sk_alloc(sk);
2159 		cgroup_sk_alloc(&sk->sk_cgrp_data);
2160 		sock_update_classid(&sk->sk_cgrp_data);
2161 		sock_update_netprioidx(&sk->sk_cgrp_data);
2162 		sk_tx_queue_clear(sk);
2163 	}
2164 
2165 	return sk;
2166 }
2167 EXPORT_SYMBOL(sk_alloc);
2168 
2169 /* Sockets having SOCK_RCU_FREE will call this function after one RCU
2170  * grace period. This is the case for UDP sockets and TCP listeners.
2171  */
2172 static void __sk_destruct(struct rcu_head *head)
2173 {
2174 	struct sock *sk = container_of(head, struct sock, sk_rcu);
2175 	struct sk_filter *filter;
2176 
2177 	if (sk->sk_destruct)
2178 		sk->sk_destruct(sk);
2179 
2180 	filter = rcu_dereference_check(sk->sk_filter,
2181 				       refcount_read(&sk->sk_wmem_alloc) == 0);
2182 	if (filter) {
2183 		sk_filter_uncharge(sk, filter);
2184 		RCU_INIT_POINTER(sk->sk_filter, NULL);
2185 	}
2186 
2187 	sock_disable_timestamp(sk, SK_FLAGS_TIMESTAMP);
2188 
2189 #ifdef CONFIG_BPF_SYSCALL
2190 	bpf_sk_storage_free(sk);
2191 #endif
2192 
2193 	if (atomic_read(&sk->sk_omem_alloc))
2194 		pr_debug("%s: optmem leakage (%d bytes) detected\n",
2195 			 __func__, atomic_read(&sk->sk_omem_alloc));
2196 
2197 	if (sk->sk_frag.page) {
2198 		put_page(sk->sk_frag.page);
2199 		sk->sk_frag.page = NULL;
2200 	}
2201 
2202 	/* We do not need to acquire sk->sk_peer_lock, we are the last user. */
2203 	put_cred(sk->sk_peer_cred);
2204 	put_pid(sk->sk_peer_pid);
2205 
2206 	if (likely(sk->sk_net_refcnt))
2207 		put_net_track(sock_net(sk), &sk->ns_tracker);
2208 	else
2209 		__netns_tracker_free(sock_net(sk), &sk->ns_tracker, false);
2210 
2211 	sk_prot_free(sk->sk_prot_creator, sk);
2212 }
2213 
2214 void sk_destruct(struct sock *sk)
2215 {
2216 	bool use_call_rcu = sock_flag(sk, SOCK_RCU_FREE);
2217 
2218 	if (rcu_access_pointer(sk->sk_reuseport_cb)) {
2219 		reuseport_detach_sock(sk);
2220 		use_call_rcu = true;
2221 	}
2222 
2223 	if (use_call_rcu)
2224 		call_rcu(&sk->sk_rcu, __sk_destruct);
2225 	else
2226 		__sk_destruct(&sk->sk_rcu);
2227 }
2228 
2229 static void __sk_free(struct sock *sk)
2230 {
2231 	if (likely(sk->sk_net_refcnt))
2232 		sock_inuse_add(sock_net(sk), -1);
2233 
2234 	if (unlikely(sk->sk_net_refcnt && sock_diag_has_destroy_listeners(sk)))
2235 		sock_diag_broadcast_destroy(sk);
2236 	else
2237 		sk_destruct(sk);
2238 }
2239 
2240 void sk_free(struct sock *sk)
2241 {
2242 	/*
2243 	 * We subtract one from sk_wmem_alloc and can know if
2244 	 * some packets are still in some tx queue.
2245 	 * If not null, sock_wfree() will call __sk_free(sk) later
2246 	 */
2247 	if (refcount_dec_and_test(&sk->sk_wmem_alloc))
2248 		__sk_free(sk);
2249 }
2250 EXPORT_SYMBOL(sk_free);
2251 
2252 static void sk_init_common(struct sock *sk)
2253 {
2254 	skb_queue_head_init(&sk->sk_receive_queue);
2255 	skb_queue_head_init(&sk->sk_write_queue);
2256 	skb_queue_head_init(&sk->sk_error_queue);
2257 
2258 	rwlock_init(&sk->sk_callback_lock);
2259 	lockdep_set_class_and_name(&sk->sk_receive_queue.lock,
2260 			af_rlock_keys + sk->sk_family,
2261 			af_family_rlock_key_strings[sk->sk_family]);
2262 	lockdep_set_class_and_name(&sk->sk_write_queue.lock,
2263 			af_wlock_keys + sk->sk_family,
2264 			af_family_wlock_key_strings[sk->sk_family]);
2265 	lockdep_set_class_and_name(&sk->sk_error_queue.lock,
2266 			af_elock_keys + sk->sk_family,
2267 			af_family_elock_key_strings[sk->sk_family]);
2268 	lockdep_set_class_and_name(&sk->sk_callback_lock,
2269 			af_callback_keys + sk->sk_family,
2270 			af_family_clock_key_strings[sk->sk_family]);
2271 }
2272 
2273 /**
2274  *	sk_clone_lock - clone a socket, and lock its clone
2275  *	@sk: the socket to clone
2276  *	@priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
2277  *
2278  *	Caller must unlock socket even in error path (bh_unlock_sock(newsk))
2279  */
2280 struct sock *sk_clone_lock(const struct sock *sk, const gfp_t priority)
2281 {
2282 	struct proto *prot = READ_ONCE(sk->sk_prot);
2283 	struct sk_filter *filter;
2284 	bool is_charged = true;
2285 	struct sock *newsk;
2286 
2287 	newsk = sk_prot_alloc(prot, priority, sk->sk_family);
2288 	if (!newsk)
2289 		goto out;
2290 
2291 	sock_copy(newsk, sk);
2292 
2293 	newsk->sk_prot_creator = prot;
2294 
2295 	/* SANITY */
2296 	if (likely(newsk->sk_net_refcnt)) {
2297 		get_net_track(sock_net(newsk), &newsk->ns_tracker, priority);
2298 		sock_inuse_add(sock_net(newsk), 1);
2299 	} else {
2300 		/* Kernel sockets are not elevating the struct net refcount.
2301 		 * Instead, use a tracker to more easily detect if a layer
2302 		 * is not properly dismantling its kernel sockets at netns
2303 		 * destroy time.
2304 		 */
2305 		__netns_tracker_alloc(sock_net(newsk), &newsk->ns_tracker,
2306 				      false, priority);
2307 	}
2308 	sk_node_init(&newsk->sk_node);
2309 	sock_lock_init(newsk);
2310 	bh_lock_sock(newsk);
2311 	newsk->sk_backlog.head	= newsk->sk_backlog.tail = NULL;
2312 	newsk->sk_backlog.len = 0;
2313 
2314 	atomic_set(&newsk->sk_rmem_alloc, 0);
2315 
2316 	/* sk_wmem_alloc set to one (see sk_free() and sock_wfree()) */
2317 	refcount_set(&newsk->sk_wmem_alloc, 1);
2318 
2319 	atomic_set(&newsk->sk_omem_alloc, 0);
2320 	sk_init_common(newsk);
2321 
2322 	newsk->sk_dst_cache	= NULL;
2323 	newsk->sk_dst_pending_confirm = 0;
2324 	newsk->sk_wmem_queued	= 0;
2325 	newsk->sk_forward_alloc = 0;
2326 	newsk->sk_reserved_mem  = 0;
2327 	atomic_set(&newsk->sk_drops, 0);
2328 	newsk->sk_send_head	= NULL;
2329 	newsk->sk_userlocks	= sk->sk_userlocks & ~SOCK_BINDPORT_LOCK;
2330 	atomic_set(&newsk->sk_zckey, 0);
2331 
2332 	sock_reset_flag(newsk, SOCK_DONE);
2333 
2334 	/* sk->sk_memcg will be populated at accept() time */
2335 	newsk->sk_memcg = NULL;
2336 
2337 	cgroup_sk_clone(&newsk->sk_cgrp_data);
2338 
2339 	rcu_read_lock();
2340 	filter = rcu_dereference(sk->sk_filter);
2341 	if (filter != NULL)
2342 		/* though it's an empty new sock, the charging may fail
2343 		 * if sysctl_optmem_max was changed between creation of
2344 		 * original socket and cloning
2345 		 */
2346 		is_charged = sk_filter_charge(newsk, filter);
2347 	RCU_INIT_POINTER(newsk->sk_filter, filter);
2348 	rcu_read_unlock();
2349 
2350 	if (unlikely(!is_charged || xfrm_sk_clone_policy(newsk, sk))) {
2351 		/* We need to make sure that we don't uncharge the new
2352 		 * socket if we couldn't charge it in the first place
2353 		 * as otherwise we uncharge the parent's filter.
2354 		 */
2355 		if (!is_charged)
2356 			RCU_INIT_POINTER(newsk->sk_filter, NULL);
2357 		sk_free_unlock_clone(newsk);
2358 		newsk = NULL;
2359 		goto out;
2360 	}
2361 	RCU_INIT_POINTER(newsk->sk_reuseport_cb, NULL);
2362 
2363 	if (bpf_sk_storage_clone(sk, newsk)) {
2364 		sk_free_unlock_clone(newsk);
2365 		newsk = NULL;
2366 		goto out;
2367 	}
2368 
2369 	/* Clear sk_user_data if parent had the pointer tagged
2370 	 * as not suitable for copying when cloning.
2371 	 */
2372 	if (sk_user_data_is_nocopy(newsk))
2373 		newsk->sk_user_data = NULL;
2374 
2375 	newsk->sk_err	   = 0;
2376 	newsk->sk_err_soft = 0;
2377 	newsk->sk_priority = 0;
2378 	newsk->sk_incoming_cpu = raw_smp_processor_id();
2379 
2380 	/* Before updating sk_refcnt, we must commit prior changes to memory
2381 	 * (Documentation/RCU/rculist_nulls.rst for details)
2382 	 */
2383 	smp_wmb();
2384 	refcount_set(&newsk->sk_refcnt, 2);
2385 
2386 	sk_set_socket(newsk, NULL);
2387 	sk_tx_queue_clear(newsk);
2388 	RCU_INIT_POINTER(newsk->sk_wq, NULL);
2389 
2390 	if (newsk->sk_prot->sockets_allocated)
2391 		sk_sockets_allocated_inc(newsk);
2392 
2393 	if (sock_needs_netstamp(sk) && newsk->sk_flags & SK_FLAGS_TIMESTAMP)
2394 		net_enable_timestamp();
2395 out:
2396 	return newsk;
2397 }
2398 EXPORT_SYMBOL_GPL(sk_clone_lock);
2399 
2400 void sk_free_unlock_clone(struct sock *sk)
2401 {
2402 	/* It is still raw copy of parent, so invalidate
2403 	 * destructor and make plain sk_free() */
2404 	sk->sk_destruct = NULL;
2405 	bh_unlock_sock(sk);
2406 	sk_free(sk);
2407 }
2408 EXPORT_SYMBOL_GPL(sk_free_unlock_clone);
2409 
2410 static u32 sk_dst_gso_max_size(struct sock *sk, struct dst_entry *dst)
2411 {
2412 	bool is_ipv6 = false;
2413 	u32 max_size;
2414 
2415 #if IS_ENABLED(CONFIG_IPV6)
2416 	is_ipv6 = (sk->sk_family == AF_INET6 &&
2417 		   !ipv6_addr_v4mapped(&sk->sk_v6_rcv_saddr));
2418 #endif
2419 	/* pairs with the WRITE_ONCE() in netif_set_gso(_ipv4)_max_size() */
2420 	max_size = is_ipv6 ? READ_ONCE(dst->dev->gso_max_size) :
2421 			READ_ONCE(dst->dev->gso_ipv4_max_size);
2422 	if (max_size > GSO_LEGACY_MAX_SIZE && !sk_is_tcp(sk))
2423 		max_size = GSO_LEGACY_MAX_SIZE;
2424 
2425 	return max_size - (MAX_TCP_HEADER + 1);
2426 }
2427 
2428 void sk_setup_caps(struct sock *sk, struct dst_entry *dst)
2429 {
2430 	u32 max_segs = 1;
2431 
2432 	sk->sk_route_caps = dst->dev->features;
2433 	if (sk_is_tcp(sk))
2434 		sk->sk_route_caps |= NETIF_F_GSO;
2435 	if (sk->sk_route_caps & NETIF_F_GSO)
2436 		sk->sk_route_caps |= NETIF_F_GSO_SOFTWARE;
2437 	if (unlikely(sk->sk_gso_disabled))
2438 		sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
2439 	if (sk_can_gso(sk)) {
2440 		if (dst->header_len && !xfrm_dst_offload_ok(dst)) {
2441 			sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
2442 		} else {
2443 			sk->sk_route_caps |= NETIF_F_SG | NETIF_F_HW_CSUM;
2444 			sk->sk_gso_max_size = sk_dst_gso_max_size(sk, dst);
2445 			/* pairs with the WRITE_ONCE() in netif_set_gso_max_segs() */
2446 			max_segs = max_t(u32, READ_ONCE(dst->dev->gso_max_segs), 1);
2447 		}
2448 	}
2449 	sk->sk_gso_max_segs = max_segs;
2450 	sk_dst_set(sk, dst);
2451 }
2452 EXPORT_SYMBOL_GPL(sk_setup_caps);
2453 
2454 /*
2455  *	Simple resource managers for sockets.
2456  */
2457 
2458 
2459 /*
2460  * Write buffer destructor automatically called from kfree_skb.
2461  */
2462 void sock_wfree(struct sk_buff *skb)
2463 {
2464 	struct sock *sk = skb->sk;
2465 	unsigned int len = skb->truesize;
2466 	bool free;
2467 
2468 	if (!sock_flag(sk, SOCK_USE_WRITE_QUEUE)) {
2469 		if (sock_flag(sk, SOCK_RCU_FREE) &&
2470 		    sk->sk_write_space == sock_def_write_space) {
2471 			rcu_read_lock();
2472 			free = refcount_sub_and_test(len, &sk->sk_wmem_alloc);
2473 			sock_def_write_space_wfree(sk);
2474 			rcu_read_unlock();
2475 			if (unlikely(free))
2476 				__sk_free(sk);
2477 			return;
2478 		}
2479 
2480 		/*
2481 		 * Keep a reference on sk_wmem_alloc, this will be released
2482 		 * after sk_write_space() call
2483 		 */
2484 		WARN_ON(refcount_sub_and_test(len - 1, &sk->sk_wmem_alloc));
2485 		sk->sk_write_space(sk);
2486 		len = 1;
2487 	}
2488 	/*
2489 	 * if sk_wmem_alloc reaches 0, we must finish what sk_free()
2490 	 * could not do because of in-flight packets
2491 	 */
2492 	if (refcount_sub_and_test(len, &sk->sk_wmem_alloc))
2493 		__sk_free(sk);
2494 }
2495 EXPORT_SYMBOL(sock_wfree);
2496 
2497 /* This variant of sock_wfree() is used by TCP,
2498  * since it sets SOCK_USE_WRITE_QUEUE.
2499  */
2500 void __sock_wfree(struct sk_buff *skb)
2501 {
2502 	struct sock *sk = skb->sk;
2503 
2504 	if (refcount_sub_and_test(skb->truesize, &sk->sk_wmem_alloc))
2505 		__sk_free(sk);
2506 }
2507 
2508 void skb_set_owner_w(struct sk_buff *skb, struct sock *sk)
2509 {
2510 	skb_orphan(skb);
2511 	skb->sk = sk;
2512 #ifdef CONFIG_INET
2513 	if (unlikely(!sk_fullsock(sk))) {
2514 		skb->destructor = sock_edemux;
2515 		sock_hold(sk);
2516 		return;
2517 	}
2518 #endif
2519 	skb->destructor = sock_wfree;
2520 	skb_set_hash_from_sk(skb, sk);
2521 	/*
2522 	 * We used to take a refcount on sk, but following operation
2523 	 * is enough to guarantee sk_free() wont free this sock until
2524 	 * all in-flight packets are completed
2525 	 */
2526 	refcount_add(skb->truesize, &sk->sk_wmem_alloc);
2527 }
2528 EXPORT_SYMBOL(skb_set_owner_w);
2529 
2530 static bool can_skb_orphan_partial(const struct sk_buff *skb)
2531 {
2532 #ifdef CONFIG_TLS_DEVICE
2533 	/* Drivers depend on in-order delivery for crypto offload,
2534 	 * partial orphan breaks out-of-order-OK logic.
2535 	 */
2536 	if (skb->decrypted)
2537 		return false;
2538 #endif
2539 	return (skb->destructor == sock_wfree ||
2540 		(IS_ENABLED(CONFIG_INET) && skb->destructor == tcp_wfree));
2541 }
2542 
2543 /* This helper is used by netem, as it can hold packets in its
2544  * delay queue. We want to allow the owner socket to send more
2545  * packets, as if they were already TX completed by a typical driver.
2546  * But we also want to keep skb->sk set because some packet schedulers
2547  * rely on it (sch_fq for example).
2548  */
2549 void skb_orphan_partial(struct sk_buff *skb)
2550 {
2551 	if (skb_is_tcp_pure_ack(skb))
2552 		return;
2553 
2554 	if (can_skb_orphan_partial(skb) && skb_set_owner_sk_safe(skb, skb->sk))
2555 		return;
2556 
2557 	skb_orphan(skb);
2558 }
2559 EXPORT_SYMBOL(skb_orphan_partial);
2560 
2561 /*
2562  * Read buffer destructor automatically called from kfree_skb.
2563  */
2564 void sock_rfree(struct sk_buff *skb)
2565 {
2566 	struct sock *sk = skb->sk;
2567 	unsigned int len = skb->truesize;
2568 
2569 	atomic_sub(len, &sk->sk_rmem_alloc);
2570 	sk_mem_uncharge(sk, len);
2571 }
2572 EXPORT_SYMBOL(sock_rfree);
2573 
2574 /*
2575  * Buffer destructor for skbs that are not used directly in read or write
2576  * path, e.g. for error handler skbs. Automatically called from kfree_skb.
2577  */
2578 void sock_efree(struct sk_buff *skb)
2579 {
2580 	sock_put(skb->sk);
2581 }
2582 EXPORT_SYMBOL(sock_efree);
2583 
2584 /* Buffer destructor for prefetch/receive path where reference count may
2585  * not be held, e.g. for listen sockets.
2586  */
2587 #ifdef CONFIG_INET
2588 void sock_pfree(struct sk_buff *skb)
2589 {
2590 	if (sk_is_refcounted(skb->sk))
2591 		sock_gen_put(skb->sk);
2592 }
2593 EXPORT_SYMBOL(sock_pfree);
2594 #endif /* CONFIG_INET */
2595 
2596 kuid_t sock_i_uid(struct sock *sk)
2597 {
2598 	kuid_t uid;
2599 
2600 	read_lock_bh(&sk->sk_callback_lock);
2601 	uid = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_uid : GLOBAL_ROOT_UID;
2602 	read_unlock_bh(&sk->sk_callback_lock);
2603 	return uid;
2604 }
2605 EXPORT_SYMBOL(sock_i_uid);
2606 
2607 unsigned long __sock_i_ino(struct sock *sk)
2608 {
2609 	unsigned long ino;
2610 
2611 	read_lock(&sk->sk_callback_lock);
2612 	ino = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_ino : 0;
2613 	read_unlock(&sk->sk_callback_lock);
2614 	return ino;
2615 }
2616 EXPORT_SYMBOL(__sock_i_ino);
2617 
2618 unsigned long sock_i_ino(struct sock *sk)
2619 {
2620 	unsigned long ino;
2621 
2622 	local_bh_disable();
2623 	ino = __sock_i_ino(sk);
2624 	local_bh_enable();
2625 	return ino;
2626 }
2627 EXPORT_SYMBOL(sock_i_ino);
2628 
2629 /*
2630  * Allocate a skb from the socket's send buffer.
2631  */
2632 struct sk_buff *sock_wmalloc(struct sock *sk, unsigned long size, int force,
2633 			     gfp_t priority)
2634 {
2635 	if (force ||
2636 	    refcount_read(&sk->sk_wmem_alloc) < READ_ONCE(sk->sk_sndbuf)) {
2637 		struct sk_buff *skb = alloc_skb(size, priority);
2638 
2639 		if (skb) {
2640 			skb_set_owner_w(skb, sk);
2641 			return skb;
2642 		}
2643 	}
2644 	return NULL;
2645 }
2646 EXPORT_SYMBOL(sock_wmalloc);
2647 
2648 static void sock_ofree(struct sk_buff *skb)
2649 {
2650 	struct sock *sk = skb->sk;
2651 
2652 	atomic_sub(skb->truesize, &sk->sk_omem_alloc);
2653 }
2654 
2655 struct sk_buff *sock_omalloc(struct sock *sk, unsigned long size,
2656 			     gfp_t priority)
2657 {
2658 	struct sk_buff *skb;
2659 
2660 	/* small safe race: SKB_TRUESIZE may differ from final skb->truesize */
2661 	if (atomic_read(&sk->sk_omem_alloc) + SKB_TRUESIZE(size) >
2662 	    READ_ONCE(sysctl_optmem_max))
2663 		return NULL;
2664 
2665 	skb = alloc_skb(size, priority);
2666 	if (!skb)
2667 		return NULL;
2668 
2669 	atomic_add(skb->truesize, &sk->sk_omem_alloc);
2670 	skb->sk = sk;
2671 	skb->destructor = sock_ofree;
2672 	return skb;
2673 }
2674 
2675 /*
2676  * Allocate a memory block from the socket's option memory buffer.
2677  */
2678 void *sock_kmalloc(struct sock *sk, int size, gfp_t priority)
2679 {
2680 	int optmem_max = READ_ONCE(sysctl_optmem_max);
2681 
2682 	if ((unsigned int)size <= optmem_max &&
2683 	    atomic_read(&sk->sk_omem_alloc) + size < optmem_max) {
2684 		void *mem;
2685 		/* First do the add, to avoid the race if kmalloc
2686 		 * might sleep.
2687 		 */
2688 		atomic_add(size, &sk->sk_omem_alloc);
2689 		mem = kmalloc(size, priority);
2690 		if (mem)
2691 			return mem;
2692 		atomic_sub(size, &sk->sk_omem_alloc);
2693 	}
2694 	return NULL;
2695 }
2696 EXPORT_SYMBOL(sock_kmalloc);
2697 
2698 /* Free an option memory block. Note, we actually want the inline
2699  * here as this allows gcc to detect the nullify and fold away the
2700  * condition entirely.
2701  */
2702 static inline void __sock_kfree_s(struct sock *sk, void *mem, int size,
2703 				  const bool nullify)
2704 {
2705 	if (WARN_ON_ONCE(!mem))
2706 		return;
2707 	if (nullify)
2708 		kfree_sensitive(mem);
2709 	else
2710 		kfree(mem);
2711 	atomic_sub(size, &sk->sk_omem_alloc);
2712 }
2713 
2714 void sock_kfree_s(struct sock *sk, void *mem, int size)
2715 {
2716 	__sock_kfree_s(sk, mem, size, false);
2717 }
2718 EXPORT_SYMBOL(sock_kfree_s);
2719 
2720 void sock_kzfree_s(struct sock *sk, void *mem, int size)
2721 {
2722 	__sock_kfree_s(sk, mem, size, true);
2723 }
2724 EXPORT_SYMBOL(sock_kzfree_s);
2725 
2726 /* It is almost wait_for_tcp_memory minus release_sock/lock_sock.
2727    I think, these locks should be removed for datagram sockets.
2728  */
2729 static long sock_wait_for_wmem(struct sock *sk, long timeo)
2730 {
2731 	DEFINE_WAIT(wait);
2732 
2733 	sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
2734 	for (;;) {
2735 		if (!timeo)
2736 			break;
2737 		if (signal_pending(current))
2738 			break;
2739 		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
2740 		prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
2741 		if (refcount_read(&sk->sk_wmem_alloc) < READ_ONCE(sk->sk_sndbuf))
2742 			break;
2743 		if (READ_ONCE(sk->sk_shutdown) & SEND_SHUTDOWN)
2744 			break;
2745 		if (READ_ONCE(sk->sk_err))
2746 			break;
2747 		timeo = schedule_timeout(timeo);
2748 	}
2749 	finish_wait(sk_sleep(sk), &wait);
2750 	return timeo;
2751 }
2752 
2753 
2754 /*
2755  *	Generic send/receive buffer handlers
2756  */
2757 
2758 struct sk_buff *sock_alloc_send_pskb(struct sock *sk, unsigned long header_len,
2759 				     unsigned long data_len, int noblock,
2760 				     int *errcode, int max_page_order)
2761 {
2762 	struct sk_buff *skb;
2763 	long timeo;
2764 	int err;
2765 
2766 	timeo = sock_sndtimeo(sk, noblock);
2767 	for (;;) {
2768 		err = sock_error(sk);
2769 		if (err != 0)
2770 			goto failure;
2771 
2772 		err = -EPIPE;
2773 		if (READ_ONCE(sk->sk_shutdown) & SEND_SHUTDOWN)
2774 			goto failure;
2775 
2776 		if (sk_wmem_alloc_get(sk) < READ_ONCE(sk->sk_sndbuf))
2777 			break;
2778 
2779 		sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
2780 		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
2781 		err = -EAGAIN;
2782 		if (!timeo)
2783 			goto failure;
2784 		if (signal_pending(current))
2785 			goto interrupted;
2786 		timeo = sock_wait_for_wmem(sk, timeo);
2787 	}
2788 	skb = alloc_skb_with_frags(header_len, data_len, max_page_order,
2789 				   errcode, sk->sk_allocation);
2790 	if (skb)
2791 		skb_set_owner_w(skb, sk);
2792 	return skb;
2793 
2794 interrupted:
2795 	err = sock_intr_errno(timeo);
2796 failure:
2797 	*errcode = err;
2798 	return NULL;
2799 }
2800 EXPORT_SYMBOL(sock_alloc_send_pskb);
2801 
2802 int __sock_cmsg_send(struct sock *sk, struct cmsghdr *cmsg,
2803 		     struct sockcm_cookie *sockc)
2804 {
2805 	u32 tsflags;
2806 
2807 	switch (cmsg->cmsg_type) {
2808 	case SO_MARK:
2809 		if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_RAW) &&
2810 		    !ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
2811 			return -EPERM;
2812 		if (cmsg->cmsg_len != CMSG_LEN(sizeof(u32)))
2813 			return -EINVAL;
2814 		sockc->mark = *(u32 *)CMSG_DATA(cmsg);
2815 		break;
2816 	case SO_TIMESTAMPING_OLD:
2817 		if (cmsg->cmsg_len != CMSG_LEN(sizeof(u32)))
2818 			return -EINVAL;
2819 
2820 		tsflags = *(u32 *)CMSG_DATA(cmsg);
2821 		if (tsflags & ~SOF_TIMESTAMPING_TX_RECORD_MASK)
2822 			return -EINVAL;
2823 
2824 		sockc->tsflags &= ~SOF_TIMESTAMPING_TX_RECORD_MASK;
2825 		sockc->tsflags |= tsflags;
2826 		break;
2827 	case SCM_TXTIME:
2828 		if (!sock_flag(sk, SOCK_TXTIME))
2829 			return -EINVAL;
2830 		if (cmsg->cmsg_len != CMSG_LEN(sizeof(u64)))
2831 			return -EINVAL;
2832 		sockc->transmit_time = get_unaligned((u64 *)CMSG_DATA(cmsg));
2833 		break;
2834 	/* SCM_RIGHTS and SCM_CREDENTIALS are semantically in SOL_UNIX. */
2835 	case SCM_RIGHTS:
2836 	case SCM_CREDENTIALS:
2837 		break;
2838 	default:
2839 		return -EINVAL;
2840 	}
2841 	return 0;
2842 }
2843 EXPORT_SYMBOL(__sock_cmsg_send);
2844 
2845 int sock_cmsg_send(struct sock *sk, struct msghdr *msg,
2846 		   struct sockcm_cookie *sockc)
2847 {
2848 	struct cmsghdr *cmsg;
2849 	int ret;
2850 
2851 	for_each_cmsghdr(cmsg, msg) {
2852 		if (!CMSG_OK(msg, cmsg))
2853 			return -EINVAL;
2854 		if (cmsg->cmsg_level != SOL_SOCKET)
2855 			continue;
2856 		ret = __sock_cmsg_send(sk, cmsg, sockc);
2857 		if (ret)
2858 			return ret;
2859 	}
2860 	return 0;
2861 }
2862 EXPORT_SYMBOL(sock_cmsg_send);
2863 
2864 static void sk_enter_memory_pressure(struct sock *sk)
2865 {
2866 	if (!sk->sk_prot->enter_memory_pressure)
2867 		return;
2868 
2869 	sk->sk_prot->enter_memory_pressure(sk);
2870 }
2871 
2872 static void sk_leave_memory_pressure(struct sock *sk)
2873 {
2874 	if (sk->sk_prot->leave_memory_pressure) {
2875 		INDIRECT_CALL_INET_1(sk->sk_prot->leave_memory_pressure,
2876 				     tcp_leave_memory_pressure, sk);
2877 	} else {
2878 		unsigned long *memory_pressure = sk->sk_prot->memory_pressure;
2879 
2880 		if (memory_pressure && READ_ONCE(*memory_pressure))
2881 			WRITE_ONCE(*memory_pressure, 0);
2882 	}
2883 }
2884 
2885 DEFINE_STATIC_KEY_FALSE(net_high_order_alloc_disable_key);
2886 
2887 /**
2888  * skb_page_frag_refill - check that a page_frag contains enough room
2889  * @sz: minimum size of the fragment we want to get
2890  * @pfrag: pointer to page_frag
2891  * @gfp: priority for memory allocation
2892  *
2893  * Note: While this allocator tries to use high order pages, there is
2894  * no guarantee that allocations succeed. Therefore, @sz MUST be
2895  * less or equal than PAGE_SIZE.
2896  */
2897 bool skb_page_frag_refill(unsigned int sz, struct page_frag *pfrag, gfp_t gfp)
2898 {
2899 	if (pfrag->page) {
2900 		if (page_ref_count(pfrag->page) == 1) {
2901 			pfrag->offset = 0;
2902 			return true;
2903 		}
2904 		if (pfrag->offset + sz <= pfrag->size)
2905 			return true;
2906 		put_page(pfrag->page);
2907 	}
2908 
2909 	pfrag->offset = 0;
2910 	if (SKB_FRAG_PAGE_ORDER &&
2911 	    !static_branch_unlikely(&net_high_order_alloc_disable_key)) {
2912 		/* Avoid direct reclaim but allow kswapd to wake */
2913 		pfrag->page = alloc_pages((gfp & ~__GFP_DIRECT_RECLAIM) |
2914 					  __GFP_COMP | __GFP_NOWARN |
2915 					  __GFP_NORETRY,
2916 					  SKB_FRAG_PAGE_ORDER);
2917 		if (likely(pfrag->page)) {
2918 			pfrag->size = PAGE_SIZE << SKB_FRAG_PAGE_ORDER;
2919 			return true;
2920 		}
2921 	}
2922 	pfrag->page = alloc_page(gfp);
2923 	if (likely(pfrag->page)) {
2924 		pfrag->size = PAGE_SIZE;
2925 		return true;
2926 	}
2927 	return false;
2928 }
2929 EXPORT_SYMBOL(skb_page_frag_refill);
2930 
2931 bool sk_page_frag_refill(struct sock *sk, struct page_frag *pfrag)
2932 {
2933 	if (likely(skb_page_frag_refill(32U, pfrag, sk->sk_allocation)))
2934 		return true;
2935 
2936 	sk_enter_memory_pressure(sk);
2937 	sk_stream_moderate_sndbuf(sk);
2938 	return false;
2939 }
2940 EXPORT_SYMBOL(sk_page_frag_refill);
2941 
2942 void __lock_sock(struct sock *sk)
2943 	__releases(&sk->sk_lock.slock)
2944 	__acquires(&sk->sk_lock.slock)
2945 {
2946 	DEFINE_WAIT(wait);
2947 
2948 	for (;;) {
2949 		prepare_to_wait_exclusive(&sk->sk_lock.wq, &wait,
2950 					TASK_UNINTERRUPTIBLE);
2951 		spin_unlock_bh(&sk->sk_lock.slock);
2952 		schedule();
2953 		spin_lock_bh(&sk->sk_lock.slock);
2954 		if (!sock_owned_by_user(sk))
2955 			break;
2956 	}
2957 	finish_wait(&sk->sk_lock.wq, &wait);
2958 }
2959 
2960 void __release_sock(struct sock *sk)
2961 	__releases(&sk->sk_lock.slock)
2962 	__acquires(&sk->sk_lock.slock)
2963 {
2964 	struct sk_buff *skb, *next;
2965 
2966 	while ((skb = sk->sk_backlog.head) != NULL) {
2967 		sk->sk_backlog.head = sk->sk_backlog.tail = NULL;
2968 
2969 		spin_unlock_bh(&sk->sk_lock.slock);
2970 
2971 		do {
2972 			next = skb->next;
2973 			prefetch(next);
2974 			DEBUG_NET_WARN_ON_ONCE(skb_dst_is_noref(skb));
2975 			skb_mark_not_on_list(skb);
2976 			sk_backlog_rcv(sk, skb);
2977 
2978 			cond_resched();
2979 
2980 			skb = next;
2981 		} while (skb != NULL);
2982 
2983 		spin_lock_bh(&sk->sk_lock.slock);
2984 	}
2985 
2986 	/*
2987 	 * Doing the zeroing here guarantee we can not loop forever
2988 	 * while a wild producer attempts to flood us.
2989 	 */
2990 	sk->sk_backlog.len = 0;
2991 }
2992 
2993 void __sk_flush_backlog(struct sock *sk)
2994 {
2995 	spin_lock_bh(&sk->sk_lock.slock);
2996 	__release_sock(sk);
2997 
2998 	if (sk->sk_prot->release_cb)
2999 		INDIRECT_CALL_INET_1(sk->sk_prot->release_cb,
3000 				     tcp_release_cb, sk);
3001 
3002 	spin_unlock_bh(&sk->sk_lock.slock);
3003 }
3004 EXPORT_SYMBOL_GPL(__sk_flush_backlog);
3005 
3006 /**
3007  * sk_wait_data - wait for data to arrive at sk_receive_queue
3008  * @sk:    sock to wait on
3009  * @timeo: for how long
3010  * @skb:   last skb seen on sk_receive_queue
3011  *
3012  * Now socket state including sk->sk_err is changed only under lock,
3013  * hence we may omit checks after joining wait queue.
3014  * We check receive queue before schedule() only as optimization;
3015  * it is very likely that release_sock() added new data.
3016  */
3017 int sk_wait_data(struct sock *sk, long *timeo, const struct sk_buff *skb)
3018 {
3019 	DEFINE_WAIT_FUNC(wait, woken_wake_function);
3020 	int rc;
3021 
3022 	add_wait_queue(sk_sleep(sk), &wait);
3023 	sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
3024 	rc = sk_wait_event(sk, timeo, skb_peek_tail(&sk->sk_receive_queue) != skb, &wait);
3025 	sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
3026 	remove_wait_queue(sk_sleep(sk), &wait);
3027 	return rc;
3028 }
3029 EXPORT_SYMBOL(sk_wait_data);
3030 
3031 /**
3032  *	__sk_mem_raise_allocated - increase memory_allocated
3033  *	@sk: socket
3034  *	@size: memory size to allocate
3035  *	@amt: pages to allocate
3036  *	@kind: allocation type
3037  *
3038  *	Similar to __sk_mem_schedule(), but does not update sk_forward_alloc
3039  */
3040 int __sk_mem_raise_allocated(struct sock *sk, int size, int amt, int kind)
3041 {
3042 	bool memcg_charge = mem_cgroup_sockets_enabled && sk->sk_memcg;
3043 	struct proto *prot = sk->sk_prot;
3044 	bool charged = true;
3045 	long allocated;
3046 
3047 	sk_memory_allocated_add(sk, amt);
3048 	allocated = sk_memory_allocated(sk);
3049 	if (memcg_charge &&
3050 	    !(charged = mem_cgroup_charge_skmem(sk->sk_memcg, amt,
3051 						gfp_memcg_charge())))
3052 		goto suppress_allocation;
3053 
3054 	/* Under limit. */
3055 	if (allocated <= sk_prot_mem_limits(sk, 0)) {
3056 		sk_leave_memory_pressure(sk);
3057 		return 1;
3058 	}
3059 
3060 	/* Under pressure. */
3061 	if (allocated > sk_prot_mem_limits(sk, 1))
3062 		sk_enter_memory_pressure(sk);
3063 
3064 	/* Over hard limit. */
3065 	if (allocated > sk_prot_mem_limits(sk, 2))
3066 		goto suppress_allocation;
3067 
3068 	/* guarantee minimum buffer size under pressure */
3069 	if (kind == SK_MEM_RECV) {
3070 		if (atomic_read(&sk->sk_rmem_alloc) < sk_get_rmem0(sk, prot))
3071 			return 1;
3072 
3073 	} else { /* SK_MEM_SEND */
3074 		int wmem0 = sk_get_wmem0(sk, prot);
3075 
3076 		if (sk->sk_type == SOCK_STREAM) {
3077 			if (sk->sk_wmem_queued < wmem0)
3078 				return 1;
3079 		} else if (refcount_read(&sk->sk_wmem_alloc) < wmem0) {
3080 				return 1;
3081 		}
3082 	}
3083 
3084 	if (sk_has_memory_pressure(sk)) {
3085 		u64 alloc;
3086 
3087 		if (!sk_under_memory_pressure(sk))
3088 			return 1;
3089 		alloc = sk_sockets_allocated_read_positive(sk);
3090 		if (sk_prot_mem_limits(sk, 2) > alloc *
3091 		    sk_mem_pages(sk->sk_wmem_queued +
3092 				 atomic_read(&sk->sk_rmem_alloc) +
3093 				 sk->sk_forward_alloc))
3094 			return 1;
3095 	}
3096 
3097 suppress_allocation:
3098 
3099 	if (kind == SK_MEM_SEND && sk->sk_type == SOCK_STREAM) {
3100 		sk_stream_moderate_sndbuf(sk);
3101 
3102 		/* Fail only if socket is _under_ its sndbuf.
3103 		 * In this case we cannot block, so that we have to fail.
3104 		 */
3105 		if (sk->sk_wmem_queued + size >= sk->sk_sndbuf) {
3106 			/* Force charge with __GFP_NOFAIL */
3107 			if (memcg_charge && !charged) {
3108 				mem_cgroup_charge_skmem(sk->sk_memcg, amt,
3109 					gfp_memcg_charge() | __GFP_NOFAIL);
3110 			}
3111 			return 1;
3112 		}
3113 	}
3114 
3115 	if (kind == SK_MEM_SEND || (kind == SK_MEM_RECV && charged))
3116 		trace_sock_exceed_buf_limit(sk, prot, allocated, kind);
3117 
3118 	sk_memory_allocated_sub(sk, amt);
3119 
3120 	if (memcg_charge && charged)
3121 		mem_cgroup_uncharge_skmem(sk->sk_memcg, amt);
3122 
3123 	return 0;
3124 }
3125 
3126 /**
3127  *	__sk_mem_schedule - increase sk_forward_alloc and memory_allocated
3128  *	@sk: socket
3129  *	@size: memory size to allocate
3130  *	@kind: allocation type
3131  *
3132  *	If kind is SK_MEM_SEND, it means wmem allocation. Otherwise it means
3133  *	rmem allocation. This function assumes that protocols which have
3134  *	memory_pressure use sk_wmem_queued as write buffer accounting.
3135  */
3136 int __sk_mem_schedule(struct sock *sk, int size, int kind)
3137 {
3138 	int ret, amt = sk_mem_pages(size);
3139 
3140 	sk_forward_alloc_add(sk, amt << PAGE_SHIFT);
3141 	ret = __sk_mem_raise_allocated(sk, size, amt, kind);
3142 	if (!ret)
3143 		sk_forward_alloc_add(sk, -(amt << PAGE_SHIFT));
3144 	return ret;
3145 }
3146 EXPORT_SYMBOL(__sk_mem_schedule);
3147 
3148 /**
3149  *	__sk_mem_reduce_allocated - reclaim memory_allocated
3150  *	@sk: socket
3151  *	@amount: number of quanta
3152  *
3153  *	Similar to __sk_mem_reclaim(), but does not update sk_forward_alloc
3154  */
3155 void __sk_mem_reduce_allocated(struct sock *sk, int amount)
3156 {
3157 	sk_memory_allocated_sub(sk, amount);
3158 
3159 	if (mem_cgroup_sockets_enabled && sk->sk_memcg)
3160 		mem_cgroup_uncharge_skmem(sk->sk_memcg, amount);
3161 
3162 	if (sk_under_global_memory_pressure(sk) &&
3163 	    (sk_memory_allocated(sk) < sk_prot_mem_limits(sk, 0)))
3164 		sk_leave_memory_pressure(sk);
3165 }
3166 
3167 /**
3168  *	__sk_mem_reclaim - reclaim sk_forward_alloc and memory_allocated
3169  *	@sk: socket
3170  *	@amount: number of bytes (rounded down to a PAGE_SIZE multiple)
3171  */
3172 void __sk_mem_reclaim(struct sock *sk, int amount)
3173 {
3174 	amount >>= PAGE_SHIFT;
3175 	sk_forward_alloc_add(sk, -(amount << PAGE_SHIFT));
3176 	__sk_mem_reduce_allocated(sk, amount);
3177 }
3178 EXPORT_SYMBOL(__sk_mem_reclaim);
3179 
3180 int sk_set_peek_off(struct sock *sk, int val)
3181 {
3182 	WRITE_ONCE(sk->sk_peek_off, val);
3183 	return 0;
3184 }
3185 EXPORT_SYMBOL_GPL(sk_set_peek_off);
3186 
3187 /*
3188  * Set of default routines for initialising struct proto_ops when
3189  * the protocol does not support a particular function. In certain
3190  * cases where it makes no sense for a protocol to have a "do nothing"
3191  * function, some default processing is provided.
3192  */
3193 
3194 int sock_no_bind(struct socket *sock, struct sockaddr *saddr, int len)
3195 {
3196 	return -EOPNOTSUPP;
3197 }
3198 EXPORT_SYMBOL(sock_no_bind);
3199 
3200 int sock_no_connect(struct socket *sock, struct sockaddr *saddr,
3201 		    int len, int flags)
3202 {
3203 	return -EOPNOTSUPP;
3204 }
3205 EXPORT_SYMBOL(sock_no_connect);
3206 
3207 int sock_no_socketpair(struct socket *sock1, struct socket *sock2)
3208 {
3209 	return -EOPNOTSUPP;
3210 }
3211 EXPORT_SYMBOL(sock_no_socketpair);
3212 
3213 int sock_no_accept(struct socket *sock, struct socket *newsock, int flags,
3214 		   bool kern)
3215 {
3216 	return -EOPNOTSUPP;
3217 }
3218 EXPORT_SYMBOL(sock_no_accept);
3219 
3220 int sock_no_getname(struct socket *sock, struct sockaddr *saddr,
3221 		    int peer)
3222 {
3223 	return -EOPNOTSUPP;
3224 }
3225 EXPORT_SYMBOL(sock_no_getname);
3226 
3227 int sock_no_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
3228 {
3229 	return -EOPNOTSUPP;
3230 }
3231 EXPORT_SYMBOL(sock_no_ioctl);
3232 
3233 int sock_no_listen(struct socket *sock, int backlog)
3234 {
3235 	return -EOPNOTSUPP;
3236 }
3237 EXPORT_SYMBOL(sock_no_listen);
3238 
3239 int sock_no_shutdown(struct socket *sock, int how)
3240 {
3241 	return -EOPNOTSUPP;
3242 }
3243 EXPORT_SYMBOL(sock_no_shutdown);
3244 
3245 int sock_no_sendmsg(struct socket *sock, struct msghdr *m, size_t len)
3246 {
3247 	return -EOPNOTSUPP;
3248 }
3249 EXPORT_SYMBOL(sock_no_sendmsg);
3250 
3251 int sock_no_sendmsg_locked(struct sock *sk, struct msghdr *m, size_t len)
3252 {
3253 	return -EOPNOTSUPP;
3254 }
3255 EXPORT_SYMBOL(sock_no_sendmsg_locked);
3256 
3257 int sock_no_recvmsg(struct socket *sock, struct msghdr *m, size_t len,
3258 		    int flags)
3259 {
3260 	return -EOPNOTSUPP;
3261 }
3262 EXPORT_SYMBOL(sock_no_recvmsg);
3263 
3264 int sock_no_mmap(struct file *file, struct socket *sock, struct vm_area_struct *vma)
3265 {
3266 	/* Mirror missing mmap method error code */
3267 	return -ENODEV;
3268 }
3269 EXPORT_SYMBOL(sock_no_mmap);
3270 
3271 /*
3272  * When a file is received (via SCM_RIGHTS, etc), we must bump the
3273  * various sock-based usage counts.
3274  */
3275 void __receive_sock(struct file *file)
3276 {
3277 	struct socket *sock;
3278 
3279 	sock = sock_from_file(file);
3280 	if (sock) {
3281 		sock_update_netprioidx(&sock->sk->sk_cgrp_data);
3282 		sock_update_classid(&sock->sk->sk_cgrp_data);
3283 	}
3284 }
3285 
3286 /*
3287  *	Default Socket Callbacks
3288  */
3289 
3290 static void sock_def_wakeup(struct sock *sk)
3291 {
3292 	struct socket_wq *wq;
3293 
3294 	rcu_read_lock();
3295 	wq = rcu_dereference(sk->sk_wq);
3296 	if (skwq_has_sleeper(wq))
3297 		wake_up_interruptible_all(&wq->wait);
3298 	rcu_read_unlock();
3299 }
3300 
3301 static void sock_def_error_report(struct sock *sk)
3302 {
3303 	struct socket_wq *wq;
3304 
3305 	rcu_read_lock();
3306 	wq = rcu_dereference(sk->sk_wq);
3307 	if (skwq_has_sleeper(wq))
3308 		wake_up_interruptible_poll(&wq->wait, EPOLLERR);
3309 	sk_wake_async(sk, SOCK_WAKE_IO, POLL_ERR);
3310 	rcu_read_unlock();
3311 }
3312 
3313 void sock_def_readable(struct sock *sk)
3314 {
3315 	struct socket_wq *wq;
3316 
3317 	trace_sk_data_ready(sk);
3318 
3319 	rcu_read_lock();
3320 	wq = rcu_dereference(sk->sk_wq);
3321 	if (skwq_has_sleeper(wq))
3322 		wake_up_interruptible_sync_poll(&wq->wait, EPOLLIN | EPOLLPRI |
3323 						EPOLLRDNORM | EPOLLRDBAND);
3324 	sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
3325 	rcu_read_unlock();
3326 }
3327 
3328 static void sock_def_write_space(struct sock *sk)
3329 {
3330 	struct socket_wq *wq;
3331 
3332 	rcu_read_lock();
3333 
3334 	/* Do not wake up a writer until he can make "significant"
3335 	 * progress.  --DaveM
3336 	 */
3337 	if (sock_writeable(sk)) {
3338 		wq = rcu_dereference(sk->sk_wq);
3339 		if (skwq_has_sleeper(wq))
3340 			wake_up_interruptible_sync_poll(&wq->wait, EPOLLOUT |
3341 						EPOLLWRNORM | EPOLLWRBAND);
3342 
3343 		/* Should agree with poll, otherwise some programs break */
3344 		sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
3345 	}
3346 
3347 	rcu_read_unlock();
3348 }
3349 
3350 /* An optimised version of sock_def_write_space(), should only be called
3351  * for SOCK_RCU_FREE sockets under RCU read section and after putting
3352  * ->sk_wmem_alloc.
3353  */
3354 static void sock_def_write_space_wfree(struct sock *sk)
3355 {
3356 	/* Do not wake up a writer until he can make "significant"
3357 	 * progress.  --DaveM
3358 	 */
3359 	if (sock_writeable(sk)) {
3360 		struct socket_wq *wq = rcu_dereference(sk->sk_wq);
3361 
3362 		/* rely on refcount_sub from sock_wfree() */
3363 		smp_mb__after_atomic();
3364 		if (wq && waitqueue_active(&wq->wait))
3365 			wake_up_interruptible_sync_poll(&wq->wait, EPOLLOUT |
3366 						EPOLLWRNORM | EPOLLWRBAND);
3367 
3368 		/* Should agree with poll, otherwise some programs break */
3369 		sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
3370 	}
3371 }
3372 
3373 static void sock_def_destruct(struct sock *sk)
3374 {
3375 }
3376 
3377 void sk_send_sigurg(struct sock *sk)
3378 {
3379 	if (sk->sk_socket && sk->sk_socket->file)
3380 		if (send_sigurg(&sk->sk_socket->file->f_owner))
3381 			sk_wake_async(sk, SOCK_WAKE_URG, POLL_PRI);
3382 }
3383 EXPORT_SYMBOL(sk_send_sigurg);
3384 
3385 void sk_reset_timer(struct sock *sk, struct timer_list* timer,
3386 		    unsigned long expires)
3387 {
3388 	if (!mod_timer(timer, expires))
3389 		sock_hold(sk);
3390 }
3391 EXPORT_SYMBOL(sk_reset_timer);
3392 
3393 void sk_stop_timer(struct sock *sk, struct timer_list* timer)
3394 {
3395 	if (del_timer(timer))
3396 		__sock_put(sk);
3397 }
3398 EXPORT_SYMBOL(sk_stop_timer);
3399 
3400 void sk_stop_timer_sync(struct sock *sk, struct timer_list *timer)
3401 {
3402 	if (del_timer_sync(timer))
3403 		__sock_put(sk);
3404 }
3405 EXPORT_SYMBOL(sk_stop_timer_sync);
3406 
3407 void sock_init_data_uid(struct socket *sock, struct sock *sk, kuid_t uid)
3408 {
3409 	sk_init_common(sk);
3410 	sk->sk_send_head	=	NULL;
3411 
3412 	timer_setup(&sk->sk_timer, NULL, 0);
3413 
3414 	sk->sk_allocation	=	GFP_KERNEL;
3415 	sk->sk_rcvbuf		=	READ_ONCE(sysctl_rmem_default);
3416 	sk->sk_sndbuf		=	READ_ONCE(sysctl_wmem_default);
3417 	sk->sk_state		=	TCP_CLOSE;
3418 	sk->sk_use_task_frag	=	true;
3419 	sk_set_socket(sk, sock);
3420 
3421 	sock_set_flag(sk, SOCK_ZAPPED);
3422 
3423 	if (sock) {
3424 		sk->sk_type	=	sock->type;
3425 		RCU_INIT_POINTER(sk->sk_wq, &sock->wq);
3426 		sock->sk	=	sk;
3427 	} else {
3428 		RCU_INIT_POINTER(sk->sk_wq, NULL);
3429 	}
3430 	sk->sk_uid	=	uid;
3431 
3432 	rwlock_init(&sk->sk_callback_lock);
3433 	if (sk->sk_kern_sock)
3434 		lockdep_set_class_and_name(
3435 			&sk->sk_callback_lock,
3436 			af_kern_callback_keys + sk->sk_family,
3437 			af_family_kern_clock_key_strings[sk->sk_family]);
3438 	else
3439 		lockdep_set_class_and_name(
3440 			&sk->sk_callback_lock,
3441 			af_callback_keys + sk->sk_family,
3442 			af_family_clock_key_strings[sk->sk_family]);
3443 
3444 	sk->sk_state_change	=	sock_def_wakeup;
3445 	sk->sk_data_ready	=	sock_def_readable;
3446 	sk->sk_write_space	=	sock_def_write_space;
3447 	sk->sk_error_report	=	sock_def_error_report;
3448 	sk->sk_destruct		=	sock_def_destruct;
3449 
3450 	sk->sk_frag.page	=	NULL;
3451 	sk->sk_frag.offset	=	0;
3452 	sk->sk_peek_off		=	-1;
3453 
3454 	sk->sk_peer_pid 	=	NULL;
3455 	sk->sk_peer_cred	=	NULL;
3456 	spin_lock_init(&sk->sk_peer_lock);
3457 
3458 	sk->sk_write_pending	=	0;
3459 	sk->sk_rcvlowat		=	1;
3460 	sk->sk_rcvtimeo		=	MAX_SCHEDULE_TIMEOUT;
3461 	sk->sk_sndtimeo		=	MAX_SCHEDULE_TIMEOUT;
3462 
3463 	sk->sk_stamp = SK_DEFAULT_STAMP;
3464 #if BITS_PER_LONG==32
3465 	seqlock_init(&sk->sk_stamp_seq);
3466 #endif
3467 	atomic_set(&sk->sk_zckey, 0);
3468 
3469 #ifdef CONFIG_NET_RX_BUSY_POLL
3470 	sk->sk_napi_id		=	0;
3471 	sk->sk_ll_usec		=	READ_ONCE(sysctl_net_busy_read);
3472 #endif
3473 
3474 	sk->sk_max_pacing_rate = ~0UL;
3475 	sk->sk_pacing_rate = ~0UL;
3476 	WRITE_ONCE(sk->sk_pacing_shift, 10);
3477 	sk->sk_incoming_cpu = -1;
3478 
3479 	sk_rx_queue_clear(sk);
3480 	/*
3481 	 * Before updating sk_refcnt, we must commit prior changes to memory
3482 	 * (Documentation/RCU/rculist_nulls.rst for details)
3483 	 */
3484 	smp_wmb();
3485 	refcount_set(&sk->sk_refcnt, 1);
3486 	atomic_set(&sk->sk_drops, 0);
3487 }
3488 EXPORT_SYMBOL(sock_init_data_uid);
3489 
3490 void sock_init_data(struct socket *sock, struct sock *sk)
3491 {
3492 	kuid_t uid = sock ?
3493 		SOCK_INODE(sock)->i_uid :
3494 		make_kuid(sock_net(sk)->user_ns, 0);
3495 
3496 	sock_init_data_uid(sock, sk, uid);
3497 }
3498 EXPORT_SYMBOL(sock_init_data);
3499 
3500 void lock_sock_nested(struct sock *sk, int subclass)
3501 {
3502 	/* The sk_lock has mutex_lock() semantics here. */
3503 	mutex_acquire(&sk->sk_lock.dep_map, subclass, 0, _RET_IP_);
3504 
3505 	might_sleep();
3506 	spin_lock_bh(&sk->sk_lock.slock);
3507 	if (sock_owned_by_user_nocheck(sk))
3508 		__lock_sock(sk);
3509 	sk->sk_lock.owned = 1;
3510 	spin_unlock_bh(&sk->sk_lock.slock);
3511 }
3512 EXPORT_SYMBOL(lock_sock_nested);
3513 
3514 void release_sock(struct sock *sk)
3515 {
3516 	spin_lock_bh(&sk->sk_lock.slock);
3517 	if (sk->sk_backlog.tail)
3518 		__release_sock(sk);
3519 
3520 	if (sk->sk_prot->release_cb)
3521 		INDIRECT_CALL_INET_1(sk->sk_prot->release_cb,
3522 				     tcp_release_cb, sk);
3523 
3524 	sock_release_ownership(sk);
3525 	if (waitqueue_active(&sk->sk_lock.wq))
3526 		wake_up(&sk->sk_lock.wq);
3527 	spin_unlock_bh(&sk->sk_lock.slock);
3528 }
3529 EXPORT_SYMBOL(release_sock);
3530 
3531 bool __lock_sock_fast(struct sock *sk) __acquires(&sk->sk_lock.slock)
3532 {
3533 	might_sleep();
3534 	spin_lock_bh(&sk->sk_lock.slock);
3535 
3536 	if (!sock_owned_by_user_nocheck(sk)) {
3537 		/*
3538 		 * Fast path return with bottom halves disabled and
3539 		 * sock::sk_lock.slock held.
3540 		 *
3541 		 * The 'mutex' is not contended and holding
3542 		 * sock::sk_lock.slock prevents all other lockers to
3543 		 * proceed so the corresponding unlock_sock_fast() can
3544 		 * avoid the slow path of release_sock() completely and
3545 		 * just release slock.
3546 		 *
3547 		 * From a semantical POV this is equivalent to 'acquiring'
3548 		 * the 'mutex', hence the corresponding lockdep
3549 		 * mutex_release() has to happen in the fast path of
3550 		 * unlock_sock_fast().
3551 		 */
3552 		return false;
3553 	}
3554 
3555 	__lock_sock(sk);
3556 	sk->sk_lock.owned = 1;
3557 	__acquire(&sk->sk_lock.slock);
3558 	spin_unlock_bh(&sk->sk_lock.slock);
3559 	return true;
3560 }
3561 EXPORT_SYMBOL(__lock_sock_fast);
3562 
3563 int sock_gettstamp(struct socket *sock, void __user *userstamp,
3564 		   bool timeval, bool time32)
3565 {
3566 	struct sock *sk = sock->sk;
3567 	struct timespec64 ts;
3568 
3569 	sock_enable_timestamp(sk, SOCK_TIMESTAMP);
3570 	ts = ktime_to_timespec64(sock_read_timestamp(sk));
3571 	if (ts.tv_sec == -1)
3572 		return -ENOENT;
3573 	if (ts.tv_sec == 0) {
3574 		ktime_t kt = ktime_get_real();
3575 		sock_write_timestamp(sk, kt);
3576 		ts = ktime_to_timespec64(kt);
3577 	}
3578 
3579 	if (timeval)
3580 		ts.tv_nsec /= 1000;
3581 
3582 #ifdef CONFIG_COMPAT_32BIT_TIME
3583 	if (time32)
3584 		return put_old_timespec32(&ts, userstamp);
3585 #endif
3586 #ifdef CONFIG_SPARC64
3587 	/* beware of padding in sparc64 timeval */
3588 	if (timeval && !in_compat_syscall()) {
3589 		struct __kernel_old_timeval __user tv = {
3590 			.tv_sec = ts.tv_sec,
3591 			.tv_usec = ts.tv_nsec,
3592 		};
3593 		if (copy_to_user(userstamp, &tv, sizeof(tv)))
3594 			return -EFAULT;
3595 		return 0;
3596 	}
3597 #endif
3598 	return put_timespec64(&ts, userstamp);
3599 }
3600 EXPORT_SYMBOL(sock_gettstamp);
3601 
3602 void sock_enable_timestamp(struct sock *sk, enum sock_flags flag)
3603 {
3604 	if (!sock_flag(sk, flag)) {
3605 		unsigned long previous_flags = sk->sk_flags;
3606 
3607 		sock_set_flag(sk, flag);
3608 		/*
3609 		 * we just set one of the two flags which require net
3610 		 * time stamping, but time stamping might have been on
3611 		 * already because of the other one
3612 		 */
3613 		if (sock_needs_netstamp(sk) &&
3614 		    !(previous_flags & SK_FLAGS_TIMESTAMP))
3615 			net_enable_timestamp();
3616 	}
3617 }
3618 
3619 int sock_recv_errqueue(struct sock *sk, struct msghdr *msg, int len,
3620 		       int level, int type)
3621 {
3622 	struct sock_exterr_skb *serr;
3623 	struct sk_buff *skb;
3624 	int copied, err;
3625 
3626 	err = -EAGAIN;
3627 	skb = sock_dequeue_err_skb(sk);
3628 	if (skb == NULL)
3629 		goto out;
3630 
3631 	copied = skb->len;
3632 	if (copied > len) {
3633 		msg->msg_flags |= MSG_TRUNC;
3634 		copied = len;
3635 	}
3636 	err = skb_copy_datagram_msg(skb, 0, msg, copied);
3637 	if (err)
3638 		goto out_free_skb;
3639 
3640 	sock_recv_timestamp(msg, sk, skb);
3641 
3642 	serr = SKB_EXT_ERR(skb);
3643 	put_cmsg(msg, level, type, sizeof(serr->ee), &serr->ee);
3644 
3645 	msg->msg_flags |= MSG_ERRQUEUE;
3646 	err = copied;
3647 
3648 out_free_skb:
3649 	kfree_skb(skb);
3650 out:
3651 	return err;
3652 }
3653 EXPORT_SYMBOL(sock_recv_errqueue);
3654 
3655 /*
3656  *	Get a socket option on an socket.
3657  *
3658  *	FIX: POSIX 1003.1g is very ambiguous here. It states that
3659  *	asynchronous errors should be reported by getsockopt. We assume
3660  *	this means if you specify SO_ERROR (otherwise whats the point of it).
3661  */
3662 int sock_common_getsockopt(struct socket *sock, int level, int optname,
3663 			   char __user *optval, int __user *optlen)
3664 {
3665 	struct sock *sk = sock->sk;
3666 
3667 	/* IPV6_ADDRFORM can change sk->sk_prot under us. */
3668 	return READ_ONCE(sk->sk_prot)->getsockopt(sk, level, optname, optval, optlen);
3669 }
3670 EXPORT_SYMBOL(sock_common_getsockopt);
3671 
3672 int sock_common_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
3673 			int flags)
3674 {
3675 	struct sock *sk = sock->sk;
3676 	int addr_len = 0;
3677 	int err;
3678 
3679 	err = sk->sk_prot->recvmsg(sk, msg, size, flags, &addr_len);
3680 	if (err >= 0)
3681 		msg->msg_namelen = addr_len;
3682 	return err;
3683 }
3684 EXPORT_SYMBOL(sock_common_recvmsg);
3685 
3686 /*
3687  *	Set socket options on an inet socket.
3688  */
3689 int sock_common_setsockopt(struct socket *sock, int level, int optname,
3690 			   sockptr_t optval, unsigned int optlen)
3691 {
3692 	struct sock *sk = sock->sk;
3693 
3694 	/* IPV6_ADDRFORM can change sk->sk_prot under us. */
3695 	return READ_ONCE(sk->sk_prot)->setsockopt(sk, level, optname, optval, optlen);
3696 }
3697 EXPORT_SYMBOL(sock_common_setsockopt);
3698 
3699 void sk_common_release(struct sock *sk)
3700 {
3701 	if (sk->sk_prot->destroy)
3702 		sk->sk_prot->destroy(sk);
3703 
3704 	/*
3705 	 * Observation: when sk_common_release is called, processes have
3706 	 * no access to socket. But net still has.
3707 	 * Step one, detach it from networking:
3708 	 *
3709 	 * A. Remove from hash tables.
3710 	 */
3711 
3712 	sk->sk_prot->unhash(sk);
3713 
3714 	/*
3715 	 * In this point socket cannot receive new packets, but it is possible
3716 	 * that some packets are in flight because some CPU runs receiver and
3717 	 * did hash table lookup before we unhashed socket. They will achieve
3718 	 * receive queue and will be purged by socket destructor.
3719 	 *
3720 	 * Also we still have packets pending on receive queue and probably,
3721 	 * our own packets waiting in device queues. sock_destroy will drain
3722 	 * receive queue, but transmitted packets will delay socket destruction
3723 	 * until the last reference will be released.
3724 	 */
3725 
3726 	sock_orphan(sk);
3727 
3728 	xfrm_sk_free_policy(sk);
3729 
3730 	sock_put(sk);
3731 }
3732 EXPORT_SYMBOL(sk_common_release);
3733 
3734 void sk_get_meminfo(const struct sock *sk, u32 *mem)
3735 {
3736 	memset(mem, 0, sizeof(*mem) * SK_MEMINFO_VARS);
3737 
3738 	mem[SK_MEMINFO_RMEM_ALLOC] = sk_rmem_alloc_get(sk);
3739 	mem[SK_MEMINFO_RCVBUF] = READ_ONCE(sk->sk_rcvbuf);
3740 	mem[SK_MEMINFO_WMEM_ALLOC] = sk_wmem_alloc_get(sk);
3741 	mem[SK_MEMINFO_SNDBUF] = READ_ONCE(sk->sk_sndbuf);
3742 	mem[SK_MEMINFO_FWD_ALLOC] = sk_forward_alloc_get(sk);
3743 	mem[SK_MEMINFO_WMEM_QUEUED] = READ_ONCE(sk->sk_wmem_queued);
3744 	mem[SK_MEMINFO_OPTMEM] = atomic_read(&sk->sk_omem_alloc);
3745 	mem[SK_MEMINFO_BACKLOG] = READ_ONCE(sk->sk_backlog.len);
3746 	mem[SK_MEMINFO_DROPS] = atomic_read(&sk->sk_drops);
3747 }
3748 
3749 #ifdef CONFIG_PROC_FS
3750 static DECLARE_BITMAP(proto_inuse_idx, PROTO_INUSE_NR);
3751 
3752 int sock_prot_inuse_get(struct net *net, struct proto *prot)
3753 {
3754 	int cpu, idx = prot->inuse_idx;
3755 	int res = 0;
3756 
3757 	for_each_possible_cpu(cpu)
3758 		res += per_cpu_ptr(net->core.prot_inuse, cpu)->val[idx];
3759 
3760 	return res >= 0 ? res : 0;
3761 }
3762 EXPORT_SYMBOL_GPL(sock_prot_inuse_get);
3763 
3764 int sock_inuse_get(struct net *net)
3765 {
3766 	int cpu, res = 0;
3767 
3768 	for_each_possible_cpu(cpu)
3769 		res += per_cpu_ptr(net->core.prot_inuse, cpu)->all;
3770 
3771 	return res;
3772 }
3773 
3774 EXPORT_SYMBOL_GPL(sock_inuse_get);
3775 
3776 static int __net_init sock_inuse_init_net(struct net *net)
3777 {
3778 	net->core.prot_inuse = alloc_percpu(struct prot_inuse);
3779 	if (net->core.prot_inuse == NULL)
3780 		return -ENOMEM;
3781 	return 0;
3782 }
3783 
3784 static void __net_exit sock_inuse_exit_net(struct net *net)
3785 {
3786 	free_percpu(net->core.prot_inuse);
3787 }
3788 
3789 static struct pernet_operations net_inuse_ops = {
3790 	.init = sock_inuse_init_net,
3791 	.exit = sock_inuse_exit_net,
3792 };
3793 
3794 static __init int net_inuse_init(void)
3795 {
3796 	if (register_pernet_subsys(&net_inuse_ops))
3797 		panic("Cannot initialize net inuse counters");
3798 
3799 	return 0;
3800 }
3801 
3802 core_initcall(net_inuse_init);
3803 
3804 static int assign_proto_idx(struct proto *prot)
3805 {
3806 	prot->inuse_idx = find_first_zero_bit(proto_inuse_idx, PROTO_INUSE_NR);
3807 
3808 	if (unlikely(prot->inuse_idx == PROTO_INUSE_NR - 1)) {
3809 		pr_err("PROTO_INUSE_NR exhausted\n");
3810 		return -ENOSPC;
3811 	}
3812 
3813 	set_bit(prot->inuse_idx, proto_inuse_idx);
3814 	return 0;
3815 }
3816 
3817 static void release_proto_idx(struct proto *prot)
3818 {
3819 	if (prot->inuse_idx != PROTO_INUSE_NR - 1)
3820 		clear_bit(prot->inuse_idx, proto_inuse_idx);
3821 }
3822 #else
3823 static inline int assign_proto_idx(struct proto *prot)
3824 {
3825 	return 0;
3826 }
3827 
3828 static inline void release_proto_idx(struct proto *prot)
3829 {
3830 }
3831 
3832 #endif
3833 
3834 static void tw_prot_cleanup(struct timewait_sock_ops *twsk_prot)
3835 {
3836 	if (!twsk_prot)
3837 		return;
3838 	kfree(twsk_prot->twsk_slab_name);
3839 	twsk_prot->twsk_slab_name = NULL;
3840 	kmem_cache_destroy(twsk_prot->twsk_slab);
3841 	twsk_prot->twsk_slab = NULL;
3842 }
3843 
3844 static int tw_prot_init(const struct proto *prot)
3845 {
3846 	struct timewait_sock_ops *twsk_prot = prot->twsk_prot;
3847 
3848 	if (!twsk_prot)
3849 		return 0;
3850 
3851 	twsk_prot->twsk_slab_name = kasprintf(GFP_KERNEL, "tw_sock_%s",
3852 					      prot->name);
3853 	if (!twsk_prot->twsk_slab_name)
3854 		return -ENOMEM;
3855 
3856 	twsk_prot->twsk_slab =
3857 		kmem_cache_create(twsk_prot->twsk_slab_name,
3858 				  twsk_prot->twsk_obj_size, 0,
3859 				  SLAB_ACCOUNT | prot->slab_flags,
3860 				  NULL);
3861 	if (!twsk_prot->twsk_slab) {
3862 		pr_crit("%s: Can't create timewait sock SLAB cache!\n",
3863 			prot->name);
3864 		return -ENOMEM;
3865 	}
3866 
3867 	return 0;
3868 }
3869 
3870 static void req_prot_cleanup(struct request_sock_ops *rsk_prot)
3871 {
3872 	if (!rsk_prot)
3873 		return;
3874 	kfree(rsk_prot->slab_name);
3875 	rsk_prot->slab_name = NULL;
3876 	kmem_cache_destroy(rsk_prot->slab);
3877 	rsk_prot->slab = NULL;
3878 }
3879 
3880 static int req_prot_init(const struct proto *prot)
3881 {
3882 	struct request_sock_ops *rsk_prot = prot->rsk_prot;
3883 
3884 	if (!rsk_prot)
3885 		return 0;
3886 
3887 	rsk_prot->slab_name = kasprintf(GFP_KERNEL, "request_sock_%s",
3888 					prot->name);
3889 	if (!rsk_prot->slab_name)
3890 		return -ENOMEM;
3891 
3892 	rsk_prot->slab = kmem_cache_create(rsk_prot->slab_name,
3893 					   rsk_prot->obj_size, 0,
3894 					   SLAB_ACCOUNT | prot->slab_flags,
3895 					   NULL);
3896 
3897 	if (!rsk_prot->slab) {
3898 		pr_crit("%s: Can't create request sock SLAB cache!\n",
3899 			prot->name);
3900 		return -ENOMEM;
3901 	}
3902 	return 0;
3903 }
3904 
3905 int proto_register(struct proto *prot, int alloc_slab)
3906 {
3907 	int ret = -ENOBUFS;
3908 
3909 	if (prot->memory_allocated && !prot->sysctl_mem) {
3910 		pr_err("%s: missing sysctl_mem\n", prot->name);
3911 		return -EINVAL;
3912 	}
3913 	if (prot->memory_allocated && !prot->per_cpu_fw_alloc) {
3914 		pr_err("%s: missing per_cpu_fw_alloc\n", prot->name);
3915 		return -EINVAL;
3916 	}
3917 	if (alloc_slab) {
3918 		prot->slab = kmem_cache_create_usercopy(prot->name,
3919 					prot->obj_size, 0,
3920 					SLAB_HWCACHE_ALIGN | SLAB_ACCOUNT |
3921 					prot->slab_flags,
3922 					prot->useroffset, prot->usersize,
3923 					NULL);
3924 
3925 		if (prot->slab == NULL) {
3926 			pr_crit("%s: Can't create sock SLAB cache!\n",
3927 				prot->name);
3928 			goto out;
3929 		}
3930 
3931 		if (req_prot_init(prot))
3932 			goto out_free_request_sock_slab;
3933 
3934 		if (tw_prot_init(prot))
3935 			goto out_free_timewait_sock_slab;
3936 	}
3937 
3938 	mutex_lock(&proto_list_mutex);
3939 	ret = assign_proto_idx(prot);
3940 	if (ret) {
3941 		mutex_unlock(&proto_list_mutex);
3942 		goto out_free_timewait_sock_slab;
3943 	}
3944 	list_add(&prot->node, &proto_list);
3945 	mutex_unlock(&proto_list_mutex);
3946 	return ret;
3947 
3948 out_free_timewait_sock_slab:
3949 	if (alloc_slab)
3950 		tw_prot_cleanup(prot->twsk_prot);
3951 out_free_request_sock_slab:
3952 	if (alloc_slab) {
3953 		req_prot_cleanup(prot->rsk_prot);
3954 
3955 		kmem_cache_destroy(prot->slab);
3956 		prot->slab = NULL;
3957 	}
3958 out:
3959 	return ret;
3960 }
3961 EXPORT_SYMBOL(proto_register);
3962 
3963 void proto_unregister(struct proto *prot)
3964 {
3965 	mutex_lock(&proto_list_mutex);
3966 	release_proto_idx(prot);
3967 	list_del(&prot->node);
3968 	mutex_unlock(&proto_list_mutex);
3969 
3970 	kmem_cache_destroy(prot->slab);
3971 	prot->slab = NULL;
3972 
3973 	req_prot_cleanup(prot->rsk_prot);
3974 	tw_prot_cleanup(prot->twsk_prot);
3975 }
3976 EXPORT_SYMBOL(proto_unregister);
3977 
3978 int sock_load_diag_module(int family, int protocol)
3979 {
3980 	if (!protocol) {
3981 		if (!sock_is_registered(family))
3982 			return -ENOENT;
3983 
3984 		return request_module("net-pf-%d-proto-%d-type-%d", PF_NETLINK,
3985 				      NETLINK_SOCK_DIAG, family);
3986 	}
3987 
3988 #ifdef CONFIG_INET
3989 	if (family == AF_INET &&
3990 	    protocol != IPPROTO_RAW &&
3991 	    protocol < MAX_INET_PROTOS &&
3992 	    !rcu_access_pointer(inet_protos[protocol]))
3993 		return -ENOENT;
3994 #endif
3995 
3996 	return request_module("net-pf-%d-proto-%d-type-%d-%d", PF_NETLINK,
3997 			      NETLINK_SOCK_DIAG, family, protocol);
3998 }
3999 EXPORT_SYMBOL(sock_load_diag_module);
4000 
4001 #ifdef CONFIG_PROC_FS
4002 static void *proto_seq_start(struct seq_file *seq, loff_t *pos)
4003 	__acquires(proto_list_mutex)
4004 {
4005 	mutex_lock(&proto_list_mutex);
4006 	return seq_list_start_head(&proto_list, *pos);
4007 }
4008 
4009 static void *proto_seq_next(struct seq_file *seq, void *v, loff_t *pos)
4010 {
4011 	return seq_list_next(v, &proto_list, pos);
4012 }
4013 
4014 static void proto_seq_stop(struct seq_file *seq, void *v)
4015 	__releases(proto_list_mutex)
4016 {
4017 	mutex_unlock(&proto_list_mutex);
4018 }
4019 
4020 static char proto_method_implemented(const void *method)
4021 {
4022 	return method == NULL ? 'n' : 'y';
4023 }
4024 static long sock_prot_memory_allocated(struct proto *proto)
4025 {
4026 	return proto->memory_allocated != NULL ? proto_memory_allocated(proto) : -1L;
4027 }
4028 
4029 static const char *sock_prot_memory_pressure(struct proto *proto)
4030 {
4031 	return proto->memory_pressure != NULL ?
4032 	proto_memory_pressure(proto) ? "yes" : "no" : "NI";
4033 }
4034 
4035 static void proto_seq_printf(struct seq_file *seq, struct proto *proto)
4036 {
4037 
4038 	seq_printf(seq, "%-9s %4u %6d  %6ld   %-3s %6u   %-3s  %-10s "
4039 			"%2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c\n",
4040 		   proto->name,
4041 		   proto->obj_size,
4042 		   sock_prot_inuse_get(seq_file_net(seq), proto),
4043 		   sock_prot_memory_allocated(proto),
4044 		   sock_prot_memory_pressure(proto),
4045 		   proto->max_header,
4046 		   proto->slab == NULL ? "no" : "yes",
4047 		   module_name(proto->owner),
4048 		   proto_method_implemented(proto->close),
4049 		   proto_method_implemented(proto->connect),
4050 		   proto_method_implemented(proto->disconnect),
4051 		   proto_method_implemented(proto->accept),
4052 		   proto_method_implemented(proto->ioctl),
4053 		   proto_method_implemented(proto->init),
4054 		   proto_method_implemented(proto->destroy),
4055 		   proto_method_implemented(proto->shutdown),
4056 		   proto_method_implemented(proto->setsockopt),
4057 		   proto_method_implemented(proto->getsockopt),
4058 		   proto_method_implemented(proto->sendmsg),
4059 		   proto_method_implemented(proto->recvmsg),
4060 		   proto_method_implemented(proto->bind),
4061 		   proto_method_implemented(proto->backlog_rcv),
4062 		   proto_method_implemented(proto->hash),
4063 		   proto_method_implemented(proto->unhash),
4064 		   proto_method_implemented(proto->get_port),
4065 		   proto_method_implemented(proto->enter_memory_pressure));
4066 }
4067 
4068 static int proto_seq_show(struct seq_file *seq, void *v)
4069 {
4070 	if (v == &proto_list)
4071 		seq_printf(seq, "%-9s %-4s %-8s %-6s %-5s %-7s %-4s %-10s %s",
4072 			   "protocol",
4073 			   "size",
4074 			   "sockets",
4075 			   "memory",
4076 			   "press",
4077 			   "maxhdr",
4078 			   "slab",
4079 			   "module",
4080 			   "cl co di ac io in de sh ss gs se re bi br ha uh gp em\n");
4081 	else
4082 		proto_seq_printf(seq, list_entry(v, struct proto, node));
4083 	return 0;
4084 }
4085 
4086 static const struct seq_operations proto_seq_ops = {
4087 	.start  = proto_seq_start,
4088 	.next   = proto_seq_next,
4089 	.stop   = proto_seq_stop,
4090 	.show   = proto_seq_show,
4091 };
4092 
4093 static __net_init int proto_init_net(struct net *net)
4094 {
4095 	if (!proc_create_net("protocols", 0444, net->proc_net, &proto_seq_ops,
4096 			sizeof(struct seq_net_private)))
4097 		return -ENOMEM;
4098 
4099 	return 0;
4100 }
4101 
4102 static __net_exit void proto_exit_net(struct net *net)
4103 {
4104 	remove_proc_entry("protocols", net->proc_net);
4105 }
4106 
4107 
4108 static __net_initdata struct pernet_operations proto_net_ops = {
4109 	.init = proto_init_net,
4110 	.exit = proto_exit_net,
4111 };
4112 
4113 static int __init proto_init(void)
4114 {
4115 	return register_pernet_subsys(&proto_net_ops);
4116 }
4117 
4118 subsys_initcall(proto_init);
4119 
4120 #endif /* PROC_FS */
4121 
4122 #ifdef CONFIG_NET_RX_BUSY_POLL
4123 bool sk_busy_loop_end(void *p, unsigned long start_time)
4124 {
4125 	struct sock *sk = p;
4126 
4127 	return !skb_queue_empty_lockless(&sk->sk_receive_queue) ||
4128 	       sk_busy_loop_timeout(sk, start_time);
4129 }
4130 EXPORT_SYMBOL(sk_busy_loop_end);
4131 #endif /* CONFIG_NET_RX_BUSY_POLL */
4132 
4133 int sock_bind_add(struct sock *sk, struct sockaddr *addr, int addr_len)
4134 {
4135 	if (!sk->sk_prot->bind_add)
4136 		return -EOPNOTSUPP;
4137 	return sk->sk_prot->bind_add(sk, addr, addr_len);
4138 }
4139 EXPORT_SYMBOL(sock_bind_add);
4140 
4141 /* Copy 'size' bytes from userspace and return `size` back to userspace */
4142 int sock_ioctl_inout(struct sock *sk, unsigned int cmd,
4143 		     void __user *arg, void *karg, size_t size)
4144 {
4145 	int ret;
4146 
4147 	if (copy_from_user(karg, arg, size))
4148 		return -EFAULT;
4149 
4150 	ret = READ_ONCE(sk->sk_prot)->ioctl(sk, cmd, karg);
4151 	if (ret)
4152 		return ret;
4153 
4154 	if (copy_to_user(arg, karg, size))
4155 		return -EFAULT;
4156 
4157 	return 0;
4158 }
4159 EXPORT_SYMBOL(sock_ioctl_inout);
4160 
4161 /* This is the most common ioctl prep function, where the result (4 bytes) is
4162  * copied back to userspace if the ioctl() returns successfully. No input is
4163  * copied from userspace as input argument.
4164  */
4165 static int sock_ioctl_out(struct sock *sk, unsigned int cmd, void __user *arg)
4166 {
4167 	int ret, karg = 0;
4168 
4169 	ret = READ_ONCE(sk->sk_prot)->ioctl(sk, cmd, &karg);
4170 	if (ret)
4171 		return ret;
4172 
4173 	return put_user(karg, (int __user *)arg);
4174 }
4175 
4176 /* A wrapper around sock ioctls, which copies the data from userspace
4177  * (depending on the protocol/ioctl), and copies back the result to userspace.
4178  * The main motivation for this function is to pass kernel memory to the
4179  * protocol ioctl callbacks, instead of userspace memory.
4180  */
4181 int sk_ioctl(struct sock *sk, unsigned int cmd, void __user *arg)
4182 {
4183 	int rc = 1;
4184 
4185 	if (sk->sk_type == SOCK_RAW && sk->sk_family == AF_INET)
4186 		rc = ipmr_sk_ioctl(sk, cmd, arg);
4187 	else if (sk->sk_type == SOCK_RAW && sk->sk_family == AF_INET6)
4188 		rc = ip6mr_sk_ioctl(sk, cmd, arg);
4189 	else if (sk_is_phonet(sk))
4190 		rc = phonet_sk_ioctl(sk, cmd, arg);
4191 
4192 	/* If ioctl was processed, returns its value */
4193 	if (rc <= 0)
4194 		return rc;
4195 
4196 	/* Otherwise call the default handler */
4197 	return sock_ioctl_out(sk, cmd, arg);
4198 }
4199 EXPORT_SYMBOL(sk_ioctl);
4200