xref: /linux/net/core/sock.c (revision cbe0e415089636170aa6eb540ca4af5dc9842a60)
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 /*
2007  * Initialize an sk_lock.
2008  *
2009  * (We also register the sk_lock with the lock validator.)
2010  */
2011 static inline void sock_lock_init(struct sock *sk)
2012 {
2013 	if (sk->sk_kern_sock)
2014 		sock_lock_init_class_and_name(
2015 			sk,
2016 			af_family_kern_slock_key_strings[sk->sk_family],
2017 			af_family_kern_slock_keys + sk->sk_family,
2018 			af_family_kern_key_strings[sk->sk_family],
2019 			af_family_kern_keys + sk->sk_family);
2020 	else
2021 		sock_lock_init_class_and_name(
2022 			sk,
2023 			af_family_slock_key_strings[sk->sk_family],
2024 			af_family_slock_keys + sk->sk_family,
2025 			af_family_key_strings[sk->sk_family],
2026 			af_family_keys + sk->sk_family);
2027 }
2028 
2029 /*
2030  * Copy all fields from osk to nsk but nsk->sk_refcnt must not change yet,
2031  * even temporarly, because of RCU lookups. sk_node should also be left as is.
2032  * We must not copy fields between sk_dontcopy_begin and sk_dontcopy_end
2033  */
2034 static void sock_copy(struct sock *nsk, const struct sock *osk)
2035 {
2036 	const struct proto *prot = READ_ONCE(osk->sk_prot);
2037 #ifdef CONFIG_SECURITY_NETWORK
2038 	void *sptr = nsk->sk_security;
2039 #endif
2040 
2041 	/* If we move sk_tx_queue_mapping out of the private section,
2042 	 * we must check if sk_tx_queue_clear() is called after
2043 	 * sock_copy() in sk_clone_lock().
2044 	 */
2045 	BUILD_BUG_ON(offsetof(struct sock, sk_tx_queue_mapping) <
2046 		     offsetof(struct sock, sk_dontcopy_begin) ||
2047 		     offsetof(struct sock, sk_tx_queue_mapping) >=
2048 		     offsetof(struct sock, sk_dontcopy_end));
2049 
2050 	memcpy(nsk, osk, offsetof(struct sock, sk_dontcopy_begin));
2051 
2052 	memcpy(&nsk->sk_dontcopy_end, &osk->sk_dontcopy_end,
2053 	       prot->obj_size - offsetof(struct sock, sk_dontcopy_end));
2054 
2055 #ifdef CONFIG_SECURITY_NETWORK
2056 	nsk->sk_security = sptr;
2057 	security_sk_clone(osk, nsk);
2058 #endif
2059 }
2060 
2061 static struct sock *sk_prot_alloc(struct proto *prot, gfp_t priority,
2062 		int family)
2063 {
2064 	struct sock *sk;
2065 	struct kmem_cache *slab;
2066 
2067 	slab = prot->slab;
2068 	if (slab != NULL) {
2069 		sk = kmem_cache_alloc(slab, priority & ~__GFP_ZERO);
2070 		if (!sk)
2071 			return sk;
2072 		if (want_init_on_alloc(priority))
2073 			sk_prot_clear_nulls(sk, prot->obj_size);
2074 	} else
2075 		sk = kmalloc(prot->obj_size, priority);
2076 
2077 	if (sk != NULL) {
2078 		if (security_sk_alloc(sk, family, priority))
2079 			goto out_free;
2080 
2081 		if (!try_module_get(prot->owner))
2082 			goto out_free_sec;
2083 	}
2084 
2085 	return sk;
2086 
2087 out_free_sec:
2088 	security_sk_free(sk);
2089 out_free:
2090 	if (slab != NULL)
2091 		kmem_cache_free(slab, sk);
2092 	else
2093 		kfree(sk);
2094 	return NULL;
2095 }
2096 
2097 static void sk_prot_free(struct proto *prot, struct sock *sk)
2098 {
2099 	struct kmem_cache *slab;
2100 	struct module *owner;
2101 
2102 	owner = prot->owner;
2103 	slab = prot->slab;
2104 
2105 	cgroup_sk_free(&sk->sk_cgrp_data);
2106 	mem_cgroup_sk_free(sk);
2107 	security_sk_free(sk);
2108 	if (slab != NULL)
2109 		kmem_cache_free(slab, sk);
2110 	else
2111 		kfree(sk);
2112 	module_put(owner);
2113 }
2114 
2115 /**
2116  *	sk_alloc - All socket objects are allocated here
2117  *	@net: the applicable net namespace
2118  *	@family: protocol family
2119  *	@priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
2120  *	@prot: struct proto associated with this new sock instance
2121  *	@kern: is this to be a kernel socket?
2122  */
2123 struct sock *sk_alloc(struct net *net, int family, gfp_t priority,
2124 		      struct proto *prot, int kern)
2125 {
2126 	struct sock *sk;
2127 
2128 	sk = sk_prot_alloc(prot, priority | __GFP_ZERO, family);
2129 	if (sk) {
2130 		sk->sk_family = family;
2131 		/*
2132 		 * See comment in struct sock definition to understand
2133 		 * why we need sk_prot_creator -acme
2134 		 */
2135 		sk->sk_prot = sk->sk_prot_creator = prot;
2136 		sk->sk_kern_sock = kern;
2137 		sock_lock_init(sk);
2138 		sk->sk_net_refcnt = kern ? 0 : 1;
2139 		if (likely(sk->sk_net_refcnt)) {
2140 			get_net_track(net, &sk->ns_tracker, priority);
2141 			sock_inuse_add(net, 1);
2142 		} else {
2143 			__netns_tracker_alloc(net, &sk->ns_tracker,
2144 					      false, priority);
2145 		}
2146 
2147 		sock_net_set(sk, net);
2148 		refcount_set(&sk->sk_wmem_alloc, 1);
2149 
2150 		mem_cgroup_sk_alloc(sk);
2151 		cgroup_sk_alloc(&sk->sk_cgrp_data);
2152 		sock_update_classid(&sk->sk_cgrp_data);
2153 		sock_update_netprioidx(&sk->sk_cgrp_data);
2154 		sk_tx_queue_clear(sk);
2155 	}
2156 
2157 	return sk;
2158 }
2159 EXPORT_SYMBOL(sk_alloc);
2160 
2161 /* Sockets having SOCK_RCU_FREE will call this function after one RCU
2162  * grace period. This is the case for UDP sockets and TCP listeners.
2163  */
2164 static void __sk_destruct(struct rcu_head *head)
2165 {
2166 	struct sock *sk = container_of(head, struct sock, sk_rcu);
2167 	struct sk_filter *filter;
2168 
2169 	if (sk->sk_destruct)
2170 		sk->sk_destruct(sk);
2171 
2172 	filter = rcu_dereference_check(sk->sk_filter,
2173 				       refcount_read(&sk->sk_wmem_alloc) == 0);
2174 	if (filter) {
2175 		sk_filter_uncharge(sk, filter);
2176 		RCU_INIT_POINTER(sk->sk_filter, NULL);
2177 	}
2178 
2179 	sock_disable_timestamp(sk, SK_FLAGS_TIMESTAMP);
2180 
2181 #ifdef CONFIG_BPF_SYSCALL
2182 	bpf_sk_storage_free(sk);
2183 #endif
2184 
2185 	if (atomic_read(&sk->sk_omem_alloc))
2186 		pr_debug("%s: optmem leakage (%d bytes) detected\n",
2187 			 __func__, atomic_read(&sk->sk_omem_alloc));
2188 
2189 	if (sk->sk_frag.page) {
2190 		put_page(sk->sk_frag.page);
2191 		sk->sk_frag.page = NULL;
2192 	}
2193 
2194 	/* We do not need to acquire sk->sk_peer_lock, we are the last user. */
2195 	put_cred(sk->sk_peer_cred);
2196 	put_pid(sk->sk_peer_pid);
2197 
2198 	if (likely(sk->sk_net_refcnt))
2199 		put_net_track(sock_net(sk), &sk->ns_tracker);
2200 	else
2201 		__netns_tracker_free(sock_net(sk), &sk->ns_tracker, false);
2202 
2203 	sk_prot_free(sk->sk_prot_creator, sk);
2204 }
2205 
2206 void sk_destruct(struct sock *sk)
2207 {
2208 	bool use_call_rcu = sock_flag(sk, SOCK_RCU_FREE);
2209 
2210 	if (rcu_access_pointer(sk->sk_reuseport_cb)) {
2211 		reuseport_detach_sock(sk);
2212 		use_call_rcu = true;
2213 	}
2214 
2215 	if (use_call_rcu)
2216 		call_rcu(&sk->sk_rcu, __sk_destruct);
2217 	else
2218 		__sk_destruct(&sk->sk_rcu);
2219 }
2220 
2221 static void __sk_free(struct sock *sk)
2222 {
2223 	if (likely(sk->sk_net_refcnt))
2224 		sock_inuse_add(sock_net(sk), -1);
2225 
2226 	if (unlikely(sk->sk_net_refcnt && sock_diag_has_destroy_listeners(sk)))
2227 		sock_diag_broadcast_destroy(sk);
2228 	else
2229 		sk_destruct(sk);
2230 }
2231 
2232 void sk_free(struct sock *sk)
2233 {
2234 	/*
2235 	 * We subtract one from sk_wmem_alloc and can know if
2236 	 * some packets are still in some tx queue.
2237 	 * If not null, sock_wfree() will call __sk_free(sk) later
2238 	 */
2239 	if (refcount_dec_and_test(&sk->sk_wmem_alloc))
2240 		__sk_free(sk);
2241 }
2242 EXPORT_SYMBOL(sk_free);
2243 
2244 static void sk_init_common(struct sock *sk)
2245 {
2246 	skb_queue_head_init(&sk->sk_receive_queue);
2247 	skb_queue_head_init(&sk->sk_write_queue);
2248 	skb_queue_head_init(&sk->sk_error_queue);
2249 
2250 	rwlock_init(&sk->sk_callback_lock);
2251 	lockdep_set_class_and_name(&sk->sk_receive_queue.lock,
2252 			af_rlock_keys + sk->sk_family,
2253 			af_family_rlock_key_strings[sk->sk_family]);
2254 	lockdep_set_class_and_name(&sk->sk_write_queue.lock,
2255 			af_wlock_keys + sk->sk_family,
2256 			af_family_wlock_key_strings[sk->sk_family]);
2257 	lockdep_set_class_and_name(&sk->sk_error_queue.lock,
2258 			af_elock_keys + sk->sk_family,
2259 			af_family_elock_key_strings[sk->sk_family]);
2260 	lockdep_set_class_and_name(&sk->sk_callback_lock,
2261 			af_callback_keys + sk->sk_family,
2262 			af_family_clock_key_strings[sk->sk_family]);
2263 }
2264 
2265 /**
2266  *	sk_clone_lock - clone a socket, and lock its clone
2267  *	@sk: the socket to clone
2268  *	@priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
2269  *
2270  *	Caller must unlock socket even in error path (bh_unlock_sock(newsk))
2271  */
2272 struct sock *sk_clone_lock(const struct sock *sk, const gfp_t priority)
2273 {
2274 	struct proto *prot = READ_ONCE(sk->sk_prot);
2275 	struct sk_filter *filter;
2276 	bool is_charged = true;
2277 	struct sock *newsk;
2278 
2279 	newsk = sk_prot_alloc(prot, priority, sk->sk_family);
2280 	if (!newsk)
2281 		goto out;
2282 
2283 	sock_copy(newsk, sk);
2284 
2285 	newsk->sk_prot_creator = prot;
2286 
2287 	/* SANITY */
2288 	if (likely(newsk->sk_net_refcnt)) {
2289 		get_net_track(sock_net(newsk), &newsk->ns_tracker, priority);
2290 		sock_inuse_add(sock_net(newsk), 1);
2291 	} else {
2292 		/* Kernel sockets are not elevating the struct net refcount.
2293 		 * Instead, use a tracker to more easily detect if a layer
2294 		 * is not properly dismantling its kernel sockets at netns
2295 		 * destroy time.
2296 		 */
2297 		__netns_tracker_alloc(sock_net(newsk), &newsk->ns_tracker,
2298 				      false, priority);
2299 	}
2300 	sk_node_init(&newsk->sk_node);
2301 	sock_lock_init(newsk);
2302 	bh_lock_sock(newsk);
2303 	newsk->sk_backlog.head	= newsk->sk_backlog.tail = NULL;
2304 	newsk->sk_backlog.len = 0;
2305 
2306 	atomic_set(&newsk->sk_rmem_alloc, 0);
2307 
2308 	/* sk_wmem_alloc set to one (see sk_free() and sock_wfree()) */
2309 	refcount_set(&newsk->sk_wmem_alloc, 1);
2310 
2311 	atomic_set(&newsk->sk_omem_alloc, 0);
2312 	sk_init_common(newsk);
2313 
2314 	newsk->sk_dst_cache	= NULL;
2315 	newsk->sk_dst_pending_confirm = 0;
2316 	newsk->sk_wmem_queued	= 0;
2317 	newsk->sk_forward_alloc = 0;
2318 	newsk->sk_reserved_mem  = 0;
2319 	atomic_set(&newsk->sk_drops, 0);
2320 	newsk->sk_send_head	= NULL;
2321 	newsk->sk_userlocks	= sk->sk_userlocks & ~SOCK_BINDPORT_LOCK;
2322 	atomic_set(&newsk->sk_zckey, 0);
2323 
2324 	sock_reset_flag(newsk, SOCK_DONE);
2325 
2326 	/* sk->sk_memcg will be populated at accept() time */
2327 	newsk->sk_memcg = NULL;
2328 
2329 	cgroup_sk_clone(&newsk->sk_cgrp_data);
2330 
2331 	rcu_read_lock();
2332 	filter = rcu_dereference(sk->sk_filter);
2333 	if (filter != NULL)
2334 		/* though it's an empty new sock, the charging may fail
2335 		 * if sysctl_optmem_max was changed between creation of
2336 		 * original socket and cloning
2337 		 */
2338 		is_charged = sk_filter_charge(newsk, filter);
2339 	RCU_INIT_POINTER(newsk->sk_filter, filter);
2340 	rcu_read_unlock();
2341 
2342 	if (unlikely(!is_charged || xfrm_sk_clone_policy(newsk, sk))) {
2343 		/* We need to make sure that we don't uncharge the new
2344 		 * socket if we couldn't charge it in the first place
2345 		 * as otherwise we uncharge the parent's filter.
2346 		 */
2347 		if (!is_charged)
2348 			RCU_INIT_POINTER(newsk->sk_filter, NULL);
2349 		sk_free_unlock_clone(newsk);
2350 		newsk = NULL;
2351 		goto out;
2352 	}
2353 	RCU_INIT_POINTER(newsk->sk_reuseport_cb, NULL);
2354 
2355 	if (bpf_sk_storage_clone(sk, newsk)) {
2356 		sk_free_unlock_clone(newsk);
2357 		newsk = NULL;
2358 		goto out;
2359 	}
2360 
2361 	/* Clear sk_user_data if parent had the pointer tagged
2362 	 * as not suitable for copying when cloning.
2363 	 */
2364 	if (sk_user_data_is_nocopy(newsk))
2365 		newsk->sk_user_data = NULL;
2366 
2367 	newsk->sk_err	   = 0;
2368 	newsk->sk_err_soft = 0;
2369 	newsk->sk_priority = 0;
2370 	newsk->sk_incoming_cpu = raw_smp_processor_id();
2371 
2372 	/* Before updating sk_refcnt, we must commit prior changes to memory
2373 	 * (Documentation/RCU/rculist_nulls.rst for details)
2374 	 */
2375 	smp_wmb();
2376 	refcount_set(&newsk->sk_refcnt, 2);
2377 
2378 	sk_set_socket(newsk, NULL);
2379 	sk_tx_queue_clear(newsk);
2380 	RCU_INIT_POINTER(newsk->sk_wq, NULL);
2381 
2382 	if (newsk->sk_prot->sockets_allocated)
2383 		sk_sockets_allocated_inc(newsk);
2384 
2385 	if (sock_needs_netstamp(sk) && newsk->sk_flags & SK_FLAGS_TIMESTAMP)
2386 		net_enable_timestamp();
2387 out:
2388 	return newsk;
2389 }
2390 EXPORT_SYMBOL_GPL(sk_clone_lock);
2391 
2392 void sk_free_unlock_clone(struct sock *sk)
2393 {
2394 	/* It is still raw copy of parent, so invalidate
2395 	 * destructor and make plain sk_free() */
2396 	sk->sk_destruct = NULL;
2397 	bh_unlock_sock(sk);
2398 	sk_free(sk);
2399 }
2400 EXPORT_SYMBOL_GPL(sk_free_unlock_clone);
2401 
2402 static u32 sk_dst_gso_max_size(struct sock *sk, struct dst_entry *dst)
2403 {
2404 	bool is_ipv6 = false;
2405 	u32 max_size;
2406 
2407 #if IS_ENABLED(CONFIG_IPV6)
2408 	is_ipv6 = (sk->sk_family == AF_INET6 &&
2409 		   !ipv6_addr_v4mapped(&sk->sk_v6_rcv_saddr));
2410 #endif
2411 	/* pairs with the WRITE_ONCE() in netif_set_gso(_ipv4)_max_size() */
2412 	max_size = is_ipv6 ? READ_ONCE(dst->dev->gso_max_size) :
2413 			READ_ONCE(dst->dev->gso_ipv4_max_size);
2414 	if (max_size > GSO_LEGACY_MAX_SIZE && !sk_is_tcp(sk))
2415 		max_size = GSO_LEGACY_MAX_SIZE;
2416 
2417 	return max_size - (MAX_TCP_HEADER + 1);
2418 }
2419 
2420 void sk_setup_caps(struct sock *sk, struct dst_entry *dst)
2421 {
2422 	u32 max_segs = 1;
2423 
2424 	sk->sk_route_caps = dst->dev->features;
2425 	if (sk_is_tcp(sk))
2426 		sk->sk_route_caps |= NETIF_F_GSO;
2427 	if (sk->sk_route_caps & NETIF_F_GSO)
2428 		sk->sk_route_caps |= NETIF_F_GSO_SOFTWARE;
2429 	if (unlikely(sk->sk_gso_disabled))
2430 		sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
2431 	if (sk_can_gso(sk)) {
2432 		if (dst->header_len && !xfrm_dst_offload_ok(dst)) {
2433 			sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
2434 		} else {
2435 			sk->sk_route_caps |= NETIF_F_SG | NETIF_F_HW_CSUM;
2436 			sk->sk_gso_max_size = sk_dst_gso_max_size(sk, dst);
2437 			/* pairs with the WRITE_ONCE() in netif_set_gso_max_segs() */
2438 			max_segs = max_t(u32, READ_ONCE(dst->dev->gso_max_segs), 1);
2439 		}
2440 	}
2441 	sk->sk_gso_max_segs = max_segs;
2442 	sk_dst_set(sk, dst);
2443 }
2444 EXPORT_SYMBOL_GPL(sk_setup_caps);
2445 
2446 /*
2447  *	Simple resource managers for sockets.
2448  */
2449 
2450 
2451 /*
2452  * Write buffer destructor automatically called from kfree_skb.
2453  */
2454 void sock_wfree(struct sk_buff *skb)
2455 {
2456 	struct sock *sk = skb->sk;
2457 	unsigned int len = skb->truesize;
2458 	bool free;
2459 
2460 	if (!sock_flag(sk, SOCK_USE_WRITE_QUEUE)) {
2461 		if (sock_flag(sk, SOCK_RCU_FREE) &&
2462 		    sk->sk_write_space == sock_def_write_space) {
2463 			rcu_read_lock();
2464 			free = refcount_sub_and_test(len, &sk->sk_wmem_alloc);
2465 			sock_def_write_space_wfree(sk);
2466 			rcu_read_unlock();
2467 			if (unlikely(free))
2468 				__sk_free(sk);
2469 			return;
2470 		}
2471 
2472 		/*
2473 		 * Keep a reference on sk_wmem_alloc, this will be released
2474 		 * after sk_write_space() call
2475 		 */
2476 		WARN_ON(refcount_sub_and_test(len - 1, &sk->sk_wmem_alloc));
2477 		sk->sk_write_space(sk);
2478 		len = 1;
2479 	}
2480 	/*
2481 	 * if sk_wmem_alloc reaches 0, we must finish what sk_free()
2482 	 * could not do because of in-flight packets
2483 	 */
2484 	if (refcount_sub_and_test(len, &sk->sk_wmem_alloc))
2485 		__sk_free(sk);
2486 }
2487 EXPORT_SYMBOL(sock_wfree);
2488 
2489 /* This variant of sock_wfree() is used by TCP,
2490  * since it sets SOCK_USE_WRITE_QUEUE.
2491  */
2492 void __sock_wfree(struct sk_buff *skb)
2493 {
2494 	struct sock *sk = skb->sk;
2495 
2496 	if (refcount_sub_and_test(skb->truesize, &sk->sk_wmem_alloc))
2497 		__sk_free(sk);
2498 }
2499 
2500 void skb_set_owner_w(struct sk_buff *skb, struct sock *sk)
2501 {
2502 	skb_orphan(skb);
2503 	skb->sk = sk;
2504 #ifdef CONFIG_INET
2505 	if (unlikely(!sk_fullsock(sk))) {
2506 		skb->destructor = sock_edemux;
2507 		sock_hold(sk);
2508 		return;
2509 	}
2510 #endif
2511 	skb->destructor = sock_wfree;
2512 	skb_set_hash_from_sk(skb, sk);
2513 	/*
2514 	 * We used to take a refcount on sk, but following operation
2515 	 * is enough to guarantee sk_free() wont free this sock until
2516 	 * all in-flight packets are completed
2517 	 */
2518 	refcount_add(skb->truesize, &sk->sk_wmem_alloc);
2519 }
2520 EXPORT_SYMBOL(skb_set_owner_w);
2521 
2522 static bool can_skb_orphan_partial(const struct sk_buff *skb)
2523 {
2524 #ifdef CONFIG_TLS_DEVICE
2525 	/* Drivers depend on in-order delivery for crypto offload,
2526 	 * partial orphan breaks out-of-order-OK logic.
2527 	 */
2528 	if (skb->decrypted)
2529 		return false;
2530 #endif
2531 	return (skb->destructor == sock_wfree ||
2532 		(IS_ENABLED(CONFIG_INET) && skb->destructor == tcp_wfree));
2533 }
2534 
2535 /* This helper is used by netem, as it can hold packets in its
2536  * delay queue. We want to allow the owner socket to send more
2537  * packets, as if they were already TX completed by a typical driver.
2538  * But we also want to keep skb->sk set because some packet schedulers
2539  * rely on it (sch_fq for example).
2540  */
2541 void skb_orphan_partial(struct sk_buff *skb)
2542 {
2543 	if (skb_is_tcp_pure_ack(skb))
2544 		return;
2545 
2546 	if (can_skb_orphan_partial(skb) && skb_set_owner_sk_safe(skb, skb->sk))
2547 		return;
2548 
2549 	skb_orphan(skb);
2550 }
2551 EXPORT_SYMBOL(skb_orphan_partial);
2552 
2553 /*
2554  * Read buffer destructor automatically called from kfree_skb.
2555  */
2556 void sock_rfree(struct sk_buff *skb)
2557 {
2558 	struct sock *sk = skb->sk;
2559 	unsigned int len = skb->truesize;
2560 
2561 	atomic_sub(len, &sk->sk_rmem_alloc);
2562 	sk_mem_uncharge(sk, len);
2563 }
2564 EXPORT_SYMBOL(sock_rfree);
2565 
2566 /*
2567  * Buffer destructor for skbs that are not used directly in read or write
2568  * path, e.g. for error handler skbs. Automatically called from kfree_skb.
2569  */
2570 void sock_efree(struct sk_buff *skb)
2571 {
2572 	sock_put(skb->sk);
2573 }
2574 EXPORT_SYMBOL(sock_efree);
2575 
2576 /* Buffer destructor for prefetch/receive path where reference count may
2577  * not be held, e.g. for listen sockets.
2578  */
2579 #ifdef CONFIG_INET
2580 void sock_pfree(struct sk_buff *skb)
2581 {
2582 	if (sk_is_refcounted(skb->sk))
2583 		sock_gen_put(skb->sk);
2584 }
2585 EXPORT_SYMBOL(sock_pfree);
2586 #endif /* CONFIG_INET */
2587 
2588 kuid_t sock_i_uid(struct sock *sk)
2589 {
2590 	kuid_t uid;
2591 
2592 	read_lock_bh(&sk->sk_callback_lock);
2593 	uid = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_uid : GLOBAL_ROOT_UID;
2594 	read_unlock_bh(&sk->sk_callback_lock);
2595 	return uid;
2596 }
2597 EXPORT_SYMBOL(sock_i_uid);
2598 
2599 unsigned long __sock_i_ino(struct sock *sk)
2600 {
2601 	unsigned long ino;
2602 
2603 	read_lock(&sk->sk_callback_lock);
2604 	ino = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_ino : 0;
2605 	read_unlock(&sk->sk_callback_lock);
2606 	return ino;
2607 }
2608 EXPORT_SYMBOL(__sock_i_ino);
2609 
2610 unsigned long sock_i_ino(struct sock *sk)
2611 {
2612 	unsigned long ino;
2613 
2614 	local_bh_disable();
2615 	ino = __sock_i_ino(sk);
2616 	local_bh_enable();
2617 	return ino;
2618 }
2619 EXPORT_SYMBOL(sock_i_ino);
2620 
2621 /*
2622  * Allocate a skb from the socket's send buffer.
2623  */
2624 struct sk_buff *sock_wmalloc(struct sock *sk, unsigned long size, int force,
2625 			     gfp_t priority)
2626 {
2627 	if (force ||
2628 	    refcount_read(&sk->sk_wmem_alloc) < READ_ONCE(sk->sk_sndbuf)) {
2629 		struct sk_buff *skb = alloc_skb(size, priority);
2630 
2631 		if (skb) {
2632 			skb_set_owner_w(skb, sk);
2633 			return skb;
2634 		}
2635 	}
2636 	return NULL;
2637 }
2638 EXPORT_SYMBOL(sock_wmalloc);
2639 
2640 static void sock_ofree(struct sk_buff *skb)
2641 {
2642 	struct sock *sk = skb->sk;
2643 
2644 	atomic_sub(skb->truesize, &sk->sk_omem_alloc);
2645 }
2646 
2647 struct sk_buff *sock_omalloc(struct sock *sk, unsigned long size,
2648 			     gfp_t priority)
2649 {
2650 	struct sk_buff *skb;
2651 
2652 	/* small safe race: SKB_TRUESIZE may differ from final skb->truesize */
2653 	if (atomic_read(&sk->sk_omem_alloc) + SKB_TRUESIZE(size) >
2654 	    READ_ONCE(sysctl_optmem_max))
2655 		return NULL;
2656 
2657 	skb = alloc_skb(size, priority);
2658 	if (!skb)
2659 		return NULL;
2660 
2661 	atomic_add(skb->truesize, &sk->sk_omem_alloc);
2662 	skb->sk = sk;
2663 	skb->destructor = sock_ofree;
2664 	return skb;
2665 }
2666 
2667 /*
2668  * Allocate a memory block from the socket's option memory buffer.
2669  */
2670 void *sock_kmalloc(struct sock *sk, int size, gfp_t priority)
2671 {
2672 	int optmem_max = READ_ONCE(sysctl_optmem_max);
2673 
2674 	if ((unsigned int)size <= optmem_max &&
2675 	    atomic_read(&sk->sk_omem_alloc) + size < optmem_max) {
2676 		void *mem;
2677 		/* First do the add, to avoid the race if kmalloc
2678 		 * might sleep.
2679 		 */
2680 		atomic_add(size, &sk->sk_omem_alloc);
2681 		mem = kmalloc(size, priority);
2682 		if (mem)
2683 			return mem;
2684 		atomic_sub(size, &sk->sk_omem_alloc);
2685 	}
2686 	return NULL;
2687 }
2688 EXPORT_SYMBOL(sock_kmalloc);
2689 
2690 /* Free an option memory block. Note, we actually want the inline
2691  * here as this allows gcc to detect the nullify and fold away the
2692  * condition entirely.
2693  */
2694 static inline void __sock_kfree_s(struct sock *sk, void *mem, int size,
2695 				  const bool nullify)
2696 {
2697 	if (WARN_ON_ONCE(!mem))
2698 		return;
2699 	if (nullify)
2700 		kfree_sensitive(mem);
2701 	else
2702 		kfree(mem);
2703 	atomic_sub(size, &sk->sk_omem_alloc);
2704 }
2705 
2706 void sock_kfree_s(struct sock *sk, void *mem, int size)
2707 {
2708 	__sock_kfree_s(sk, mem, size, false);
2709 }
2710 EXPORT_SYMBOL(sock_kfree_s);
2711 
2712 void sock_kzfree_s(struct sock *sk, void *mem, int size)
2713 {
2714 	__sock_kfree_s(sk, mem, size, true);
2715 }
2716 EXPORT_SYMBOL(sock_kzfree_s);
2717 
2718 /* It is almost wait_for_tcp_memory minus release_sock/lock_sock.
2719    I think, these locks should be removed for datagram sockets.
2720  */
2721 static long sock_wait_for_wmem(struct sock *sk, long timeo)
2722 {
2723 	DEFINE_WAIT(wait);
2724 
2725 	sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
2726 	for (;;) {
2727 		if (!timeo)
2728 			break;
2729 		if (signal_pending(current))
2730 			break;
2731 		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
2732 		prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
2733 		if (refcount_read(&sk->sk_wmem_alloc) < READ_ONCE(sk->sk_sndbuf))
2734 			break;
2735 		if (READ_ONCE(sk->sk_shutdown) & SEND_SHUTDOWN)
2736 			break;
2737 		if (READ_ONCE(sk->sk_err))
2738 			break;
2739 		timeo = schedule_timeout(timeo);
2740 	}
2741 	finish_wait(sk_sleep(sk), &wait);
2742 	return timeo;
2743 }
2744 
2745 
2746 /*
2747  *	Generic send/receive buffer handlers
2748  */
2749 
2750 struct sk_buff *sock_alloc_send_pskb(struct sock *sk, unsigned long header_len,
2751 				     unsigned long data_len, int noblock,
2752 				     int *errcode, int max_page_order)
2753 {
2754 	struct sk_buff *skb;
2755 	long timeo;
2756 	int err;
2757 
2758 	timeo = sock_sndtimeo(sk, noblock);
2759 	for (;;) {
2760 		err = sock_error(sk);
2761 		if (err != 0)
2762 			goto failure;
2763 
2764 		err = -EPIPE;
2765 		if (READ_ONCE(sk->sk_shutdown) & SEND_SHUTDOWN)
2766 			goto failure;
2767 
2768 		if (sk_wmem_alloc_get(sk) < READ_ONCE(sk->sk_sndbuf))
2769 			break;
2770 
2771 		sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
2772 		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
2773 		err = -EAGAIN;
2774 		if (!timeo)
2775 			goto failure;
2776 		if (signal_pending(current))
2777 			goto interrupted;
2778 		timeo = sock_wait_for_wmem(sk, timeo);
2779 	}
2780 	skb = alloc_skb_with_frags(header_len, data_len, max_page_order,
2781 				   errcode, sk->sk_allocation);
2782 	if (skb)
2783 		skb_set_owner_w(skb, sk);
2784 	return skb;
2785 
2786 interrupted:
2787 	err = sock_intr_errno(timeo);
2788 failure:
2789 	*errcode = err;
2790 	return NULL;
2791 }
2792 EXPORT_SYMBOL(sock_alloc_send_pskb);
2793 
2794 int __sock_cmsg_send(struct sock *sk, struct cmsghdr *cmsg,
2795 		     struct sockcm_cookie *sockc)
2796 {
2797 	u32 tsflags;
2798 
2799 	switch (cmsg->cmsg_type) {
2800 	case SO_MARK:
2801 		if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_RAW) &&
2802 		    !ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
2803 			return -EPERM;
2804 		if (cmsg->cmsg_len != CMSG_LEN(sizeof(u32)))
2805 			return -EINVAL;
2806 		sockc->mark = *(u32 *)CMSG_DATA(cmsg);
2807 		break;
2808 	case SO_TIMESTAMPING_OLD:
2809 		if (cmsg->cmsg_len != CMSG_LEN(sizeof(u32)))
2810 			return -EINVAL;
2811 
2812 		tsflags = *(u32 *)CMSG_DATA(cmsg);
2813 		if (tsflags & ~SOF_TIMESTAMPING_TX_RECORD_MASK)
2814 			return -EINVAL;
2815 
2816 		sockc->tsflags &= ~SOF_TIMESTAMPING_TX_RECORD_MASK;
2817 		sockc->tsflags |= tsflags;
2818 		break;
2819 	case SCM_TXTIME:
2820 		if (!sock_flag(sk, SOCK_TXTIME))
2821 			return -EINVAL;
2822 		if (cmsg->cmsg_len != CMSG_LEN(sizeof(u64)))
2823 			return -EINVAL;
2824 		sockc->transmit_time = get_unaligned((u64 *)CMSG_DATA(cmsg));
2825 		break;
2826 	/* SCM_RIGHTS and SCM_CREDENTIALS are semantically in SOL_UNIX. */
2827 	case SCM_RIGHTS:
2828 	case SCM_CREDENTIALS:
2829 		break;
2830 	default:
2831 		return -EINVAL;
2832 	}
2833 	return 0;
2834 }
2835 EXPORT_SYMBOL(__sock_cmsg_send);
2836 
2837 int sock_cmsg_send(struct sock *sk, struct msghdr *msg,
2838 		   struct sockcm_cookie *sockc)
2839 {
2840 	struct cmsghdr *cmsg;
2841 	int ret;
2842 
2843 	for_each_cmsghdr(cmsg, msg) {
2844 		if (!CMSG_OK(msg, cmsg))
2845 			return -EINVAL;
2846 		if (cmsg->cmsg_level != SOL_SOCKET)
2847 			continue;
2848 		ret = __sock_cmsg_send(sk, cmsg, sockc);
2849 		if (ret)
2850 			return ret;
2851 	}
2852 	return 0;
2853 }
2854 EXPORT_SYMBOL(sock_cmsg_send);
2855 
2856 static void sk_enter_memory_pressure(struct sock *sk)
2857 {
2858 	if (!sk->sk_prot->enter_memory_pressure)
2859 		return;
2860 
2861 	sk->sk_prot->enter_memory_pressure(sk);
2862 }
2863 
2864 static void sk_leave_memory_pressure(struct sock *sk)
2865 {
2866 	if (sk->sk_prot->leave_memory_pressure) {
2867 		INDIRECT_CALL_INET_1(sk->sk_prot->leave_memory_pressure,
2868 				     tcp_leave_memory_pressure, sk);
2869 	} else {
2870 		unsigned long *memory_pressure = sk->sk_prot->memory_pressure;
2871 
2872 		if (memory_pressure && READ_ONCE(*memory_pressure))
2873 			WRITE_ONCE(*memory_pressure, 0);
2874 	}
2875 }
2876 
2877 DEFINE_STATIC_KEY_FALSE(net_high_order_alloc_disable_key);
2878 
2879 /**
2880  * skb_page_frag_refill - check that a page_frag contains enough room
2881  * @sz: minimum size of the fragment we want to get
2882  * @pfrag: pointer to page_frag
2883  * @gfp: priority for memory allocation
2884  *
2885  * Note: While this allocator tries to use high order pages, there is
2886  * no guarantee that allocations succeed. Therefore, @sz MUST be
2887  * less or equal than PAGE_SIZE.
2888  */
2889 bool skb_page_frag_refill(unsigned int sz, struct page_frag *pfrag, gfp_t gfp)
2890 {
2891 	if (pfrag->page) {
2892 		if (page_ref_count(pfrag->page) == 1) {
2893 			pfrag->offset = 0;
2894 			return true;
2895 		}
2896 		if (pfrag->offset + sz <= pfrag->size)
2897 			return true;
2898 		put_page(pfrag->page);
2899 	}
2900 
2901 	pfrag->offset = 0;
2902 	if (SKB_FRAG_PAGE_ORDER &&
2903 	    !static_branch_unlikely(&net_high_order_alloc_disable_key)) {
2904 		/* Avoid direct reclaim but allow kswapd to wake */
2905 		pfrag->page = alloc_pages((gfp & ~__GFP_DIRECT_RECLAIM) |
2906 					  __GFP_COMP | __GFP_NOWARN |
2907 					  __GFP_NORETRY,
2908 					  SKB_FRAG_PAGE_ORDER);
2909 		if (likely(pfrag->page)) {
2910 			pfrag->size = PAGE_SIZE << SKB_FRAG_PAGE_ORDER;
2911 			return true;
2912 		}
2913 	}
2914 	pfrag->page = alloc_page(gfp);
2915 	if (likely(pfrag->page)) {
2916 		pfrag->size = PAGE_SIZE;
2917 		return true;
2918 	}
2919 	return false;
2920 }
2921 EXPORT_SYMBOL(skb_page_frag_refill);
2922 
2923 bool sk_page_frag_refill(struct sock *sk, struct page_frag *pfrag)
2924 {
2925 	if (likely(skb_page_frag_refill(32U, pfrag, sk->sk_allocation)))
2926 		return true;
2927 
2928 	sk_enter_memory_pressure(sk);
2929 	sk_stream_moderate_sndbuf(sk);
2930 	return false;
2931 }
2932 EXPORT_SYMBOL(sk_page_frag_refill);
2933 
2934 void __lock_sock(struct sock *sk)
2935 	__releases(&sk->sk_lock.slock)
2936 	__acquires(&sk->sk_lock.slock)
2937 {
2938 	DEFINE_WAIT(wait);
2939 
2940 	for (;;) {
2941 		prepare_to_wait_exclusive(&sk->sk_lock.wq, &wait,
2942 					TASK_UNINTERRUPTIBLE);
2943 		spin_unlock_bh(&sk->sk_lock.slock);
2944 		schedule();
2945 		spin_lock_bh(&sk->sk_lock.slock);
2946 		if (!sock_owned_by_user(sk))
2947 			break;
2948 	}
2949 	finish_wait(&sk->sk_lock.wq, &wait);
2950 }
2951 
2952 void __release_sock(struct sock *sk)
2953 	__releases(&sk->sk_lock.slock)
2954 	__acquires(&sk->sk_lock.slock)
2955 {
2956 	struct sk_buff *skb, *next;
2957 
2958 	while ((skb = sk->sk_backlog.head) != NULL) {
2959 		sk->sk_backlog.head = sk->sk_backlog.tail = NULL;
2960 
2961 		spin_unlock_bh(&sk->sk_lock.slock);
2962 
2963 		do {
2964 			next = skb->next;
2965 			prefetch(next);
2966 			DEBUG_NET_WARN_ON_ONCE(skb_dst_is_noref(skb));
2967 			skb_mark_not_on_list(skb);
2968 			sk_backlog_rcv(sk, skb);
2969 
2970 			cond_resched();
2971 
2972 			skb = next;
2973 		} while (skb != NULL);
2974 
2975 		spin_lock_bh(&sk->sk_lock.slock);
2976 	}
2977 
2978 	/*
2979 	 * Doing the zeroing here guarantee we can not loop forever
2980 	 * while a wild producer attempts to flood us.
2981 	 */
2982 	sk->sk_backlog.len = 0;
2983 }
2984 
2985 void __sk_flush_backlog(struct sock *sk)
2986 {
2987 	spin_lock_bh(&sk->sk_lock.slock);
2988 	__release_sock(sk);
2989 
2990 	if (sk->sk_prot->release_cb)
2991 		INDIRECT_CALL_INET_1(sk->sk_prot->release_cb,
2992 				     tcp_release_cb, sk);
2993 
2994 	spin_unlock_bh(&sk->sk_lock.slock);
2995 }
2996 EXPORT_SYMBOL_GPL(__sk_flush_backlog);
2997 
2998 /**
2999  * sk_wait_data - wait for data to arrive at sk_receive_queue
3000  * @sk:    sock to wait on
3001  * @timeo: for how long
3002  * @skb:   last skb seen on sk_receive_queue
3003  *
3004  * Now socket state including sk->sk_err is changed only under lock,
3005  * hence we may omit checks after joining wait queue.
3006  * We check receive queue before schedule() only as optimization;
3007  * it is very likely that release_sock() added new data.
3008  */
3009 int sk_wait_data(struct sock *sk, long *timeo, const struct sk_buff *skb)
3010 {
3011 	DEFINE_WAIT_FUNC(wait, woken_wake_function);
3012 	int rc;
3013 
3014 	add_wait_queue(sk_sleep(sk), &wait);
3015 	sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
3016 	rc = sk_wait_event(sk, timeo, skb_peek_tail(&sk->sk_receive_queue) != skb, &wait);
3017 	sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
3018 	remove_wait_queue(sk_sleep(sk), &wait);
3019 	return rc;
3020 }
3021 EXPORT_SYMBOL(sk_wait_data);
3022 
3023 /**
3024  *	__sk_mem_raise_allocated - increase memory_allocated
3025  *	@sk: socket
3026  *	@size: memory size to allocate
3027  *	@amt: pages to allocate
3028  *	@kind: allocation type
3029  *
3030  *	Similar to __sk_mem_schedule(), but does not update sk_forward_alloc.
3031  *
3032  *	Unlike the globally shared limits among the sockets under same protocol,
3033  *	consuming the budget of a memcg won't have direct effect on other ones.
3034  *	So be optimistic about memcg's tolerance, and leave the callers to decide
3035  *	whether or not to raise allocated through sk_under_memory_pressure() or
3036  *	its variants.
3037  */
3038 int __sk_mem_raise_allocated(struct sock *sk, int size, int amt, int kind)
3039 {
3040 	struct mem_cgroup *memcg = mem_cgroup_sockets_enabled ? sk->sk_memcg : NULL;
3041 	struct proto *prot = sk->sk_prot;
3042 	bool charged = false;
3043 	long allocated;
3044 
3045 	sk_memory_allocated_add(sk, amt);
3046 	allocated = sk_memory_allocated(sk);
3047 
3048 	if (memcg) {
3049 		if (!mem_cgroup_charge_skmem(memcg, amt, gfp_memcg_charge()))
3050 			goto suppress_allocation;
3051 		charged = true;
3052 	}
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 (either global
3069 	 * or memcg) to make sure features described in RFC 7323 (TCP
3070 	 * Extensions for High Performance) work properly.
3071 	 *
3072 	 * This rule does NOT stand when exceeds global or memcg's hard
3073 	 * limit, or else a DoS attack can be taken place by spawning
3074 	 * lots of sockets whose usage are under minimum buffer size.
3075 	 */
3076 	if (kind == SK_MEM_RECV) {
3077 		if (atomic_read(&sk->sk_rmem_alloc) < sk_get_rmem0(sk, prot))
3078 			return 1;
3079 
3080 	} else { /* SK_MEM_SEND */
3081 		int wmem0 = sk_get_wmem0(sk, prot);
3082 
3083 		if (sk->sk_type == SOCK_STREAM) {
3084 			if (sk->sk_wmem_queued < wmem0)
3085 				return 1;
3086 		} else if (refcount_read(&sk->sk_wmem_alloc) < wmem0) {
3087 				return 1;
3088 		}
3089 	}
3090 
3091 	if (sk_has_memory_pressure(sk)) {
3092 		u64 alloc;
3093 
3094 		/* The following 'average' heuristic is within the
3095 		 * scope of global accounting, so it only makes
3096 		 * sense for global memory pressure.
3097 		 */
3098 		if (!sk_under_global_memory_pressure(sk))
3099 			return 1;
3100 
3101 		/* Try to be fair among all the sockets under global
3102 		 * pressure by allowing the ones that below average
3103 		 * usage to raise.
3104 		 */
3105 		alloc = sk_sockets_allocated_read_positive(sk);
3106 		if (sk_prot_mem_limits(sk, 2) > alloc *
3107 		    sk_mem_pages(sk->sk_wmem_queued +
3108 				 atomic_read(&sk->sk_rmem_alloc) +
3109 				 sk->sk_forward_alloc))
3110 			return 1;
3111 	}
3112 
3113 suppress_allocation:
3114 
3115 	if (kind == SK_MEM_SEND && sk->sk_type == SOCK_STREAM) {
3116 		sk_stream_moderate_sndbuf(sk);
3117 
3118 		/* Fail only if socket is _under_ its sndbuf.
3119 		 * In this case we cannot block, so that we have to fail.
3120 		 */
3121 		if (sk->sk_wmem_queued + size >= sk->sk_sndbuf) {
3122 			/* Force charge with __GFP_NOFAIL */
3123 			if (memcg && !charged) {
3124 				mem_cgroup_charge_skmem(memcg, amt,
3125 					gfp_memcg_charge() | __GFP_NOFAIL);
3126 			}
3127 			return 1;
3128 		}
3129 	}
3130 
3131 	if (kind == SK_MEM_SEND || (kind == SK_MEM_RECV && charged))
3132 		trace_sock_exceed_buf_limit(sk, prot, allocated, kind);
3133 
3134 	sk_memory_allocated_sub(sk, amt);
3135 
3136 	if (charged)
3137 		mem_cgroup_uncharge_skmem(memcg, amt);
3138 
3139 	return 0;
3140 }
3141 
3142 /**
3143  *	__sk_mem_schedule - increase sk_forward_alloc and memory_allocated
3144  *	@sk: socket
3145  *	@size: memory size to allocate
3146  *	@kind: allocation type
3147  *
3148  *	If kind is SK_MEM_SEND, it means wmem allocation. Otherwise it means
3149  *	rmem allocation. This function assumes that protocols which have
3150  *	memory_pressure use sk_wmem_queued as write buffer accounting.
3151  */
3152 int __sk_mem_schedule(struct sock *sk, int size, int kind)
3153 {
3154 	int ret, amt = sk_mem_pages(size);
3155 
3156 	sk_forward_alloc_add(sk, amt << PAGE_SHIFT);
3157 	ret = __sk_mem_raise_allocated(sk, size, amt, kind);
3158 	if (!ret)
3159 		sk_forward_alloc_add(sk, -(amt << PAGE_SHIFT));
3160 	return ret;
3161 }
3162 EXPORT_SYMBOL(__sk_mem_schedule);
3163 
3164 /**
3165  *	__sk_mem_reduce_allocated - reclaim memory_allocated
3166  *	@sk: socket
3167  *	@amount: number of quanta
3168  *
3169  *	Similar to __sk_mem_reclaim(), but does not update sk_forward_alloc
3170  */
3171 void __sk_mem_reduce_allocated(struct sock *sk, int amount)
3172 {
3173 	sk_memory_allocated_sub(sk, amount);
3174 
3175 	if (mem_cgroup_sockets_enabled && sk->sk_memcg)
3176 		mem_cgroup_uncharge_skmem(sk->sk_memcg, amount);
3177 
3178 	if (sk_under_global_memory_pressure(sk) &&
3179 	    (sk_memory_allocated(sk) < sk_prot_mem_limits(sk, 0)))
3180 		sk_leave_memory_pressure(sk);
3181 }
3182 
3183 /**
3184  *	__sk_mem_reclaim - reclaim sk_forward_alloc and memory_allocated
3185  *	@sk: socket
3186  *	@amount: number of bytes (rounded down to a PAGE_SIZE multiple)
3187  */
3188 void __sk_mem_reclaim(struct sock *sk, int amount)
3189 {
3190 	amount >>= PAGE_SHIFT;
3191 	sk_forward_alloc_add(sk, -(amount << PAGE_SHIFT));
3192 	__sk_mem_reduce_allocated(sk, amount);
3193 }
3194 EXPORT_SYMBOL(__sk_mem_reclaim);
3195 
3196 int sk_set_peek_off(struct sock *sk, int val)
3197 {
3198 	WRITE_ONCE(sk->sk_peek_off, val);
3199 	return 0;
3200 }
3201 EXPORT_SYMBOL_GPL(sk_set_peek_off);
3202 
3203 /*
3204  * Set of default routines for initialising struct proto_ops when
3205  * the protocol does not support a particular function. In certain
3206  * cases where it makes no sense for a protocol to have a "do nothing"
3207  * function, some default processing is provided.
3208  */
3209 
3210 int sock_no_bind(struct socket *sock, struct sockaddr *saddr, int len)
3211 {
3212 	return -EOPNOTSUPP;
3213 }
3214 EXPORT_SYMBOL(sock_no_bind);
3215 
3216 int sock_no_connect(struct socket *sock, struct sockaddr *saddr,
3217 		    int len, int flags)
3218 {
3219 	return -EOPNOTSUPP;
3220 }
3221 EXPORT_SYMBOL(sock_no_connect);
3222 
3223 int sock_no_socketpair(struct socket *sock1, struct socket *sock2)
3224 {
3225 	return -EOPNOTSUPP;
3226 }
3227 EXPORT_SYMBOL(sock_no_socketpair);
3228 
3229 int sock_no_accept(struct socket *sock, struct socket *newsock, int flags,
3230 		   bool kern)
3231 {
3232 	return -EOPNOTSUPP;
3233 }
3234 EXPORT_SYMBOL(sock_no_accept);
3235 
3236 int sock_no_getname(struct socket *sock, struct sockaddr *saddr,
3237 		    int peer)
3238 {
3239 	return -EOPNOTSUPP;
3240 }
3241 EXPORT_SYMBOL(sock_no_getname);
3242 
3243 int sock_no_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
3244 {
3245 	return -EOPNOTSUPP;
3246 }
3247 EXPORT_SYMBOL(sock_no_ioctl);
3248 
3249 int sock_no_listen(struct socket *sock, int backlog)
3250 {
3251 	return -EOPNOTSUPP;
3252 }
3253 EXPORT_SYMBOL(sock_no_listen);
3254 
3255 int sock_no_shutdown(struct socket *sock, int how)
3256 {
3257 	return -EOPNOTSUPP;
3258 }
3259 EXPORT_SYMBOL(sock_no_shutdown);
3260 
3261 int sock_no_sendmsg(struct socket *sock, struct msghdr *m, size_t len)
3262 {
3263 	return -EOPNOTSUPP;
3264 }
3265 EXPORT_SYMBOL(sock_no_sendmsg);
3266 
3267 int sock_no_sendmsg_locked(struct sock *sk, struct msghdr *m, size_t len)
3268 {
3269 	return -EOPNOTSUPP;
3270 }
3271 EXPORT_SYMBOL(sock_no_sendmsg_locked);
3272 
3273 int sock_no_recvmsg(struct socket *sock, struct msghdr *m, size_t len,
3274 		    int flags)
3275 {
3276 	return -EOPNOTSUPP;
3277 }
3278 EXPORT_SYMBOL(sock_no_recvmsg);
3279 
3280 int sock_no_mmap(struct file *file, struct socket *sock, struct vm_area_struct *vma)
3281 {
3282 	/* Mirror missing mmap method error code */
3283 	return -ENODEV;
3284 }
3285 EXPORT_SYMBOL(sock_no_mmap);
3286 
3287 /*
3288  * When a file is received (via SCM_RIGHTS, etc), we must bump the
3289  * various sock-based usage counts.
3290  */
3291 void __receive_sock(struct file *file)
3292 {
3293 	struct socket *sock;
3294 
3295 	sock = sock_from_file(file);
3296 	if (sock) {
3297 		sock_update_netprioidx(&sock->sk->sk_cgrp_data);
3298 		sock_update_classid(&sock->sk->sk_cgrp_data);
3299 	}
3300 }
3301 
3302 /*
3303  *	Default Socket Callbacks
3304  */
3305 
3306 static void sock_def_wakeup(struct sock *sk)
3307 {
3308 	struct socket_wq *wq;
3309 
3310 	rcu_read_lock();
3311 	wq = rcu_dereference(sk->sk_wq);
3312 	if (skwq_has_sleeper(wq))
3313 		wake_up_interruptible_all(&wq->wait);
3314 	rcu_read_unlock();
3315 }
3316 
3317 static void sock_def_error_report(struct sock *sk)
3318 {
3319 	struct socket_wq *wq;
3320 
3321 	rcu_read_lock();
3322 	wq = rcu_dereference(sk->sk_wq);
3323 	if (skwq_has_sleeper(wq))
3324 		wake_up_interruptible_poll(&wq->wait, EPOLLERR);
3325 	sk_wake_async(sk, SOCK_WAKE_IO, POLL_ERR);
3326 	rcu_read_unlock();
3327 }
3328 
3329 void sock_def_readable(struct sock *sk)
3330 {
3331 	struct socket_wq *wq;
3332 
3333 	trace_sk_data_ready(sk);
3334 
3335 	rcu_read_lock();
3336 	wq = rcu_dereference(sk->sk_wq);
3337 	if (skwq_has_sleeper(wq))
3338 		wake_up_interruptible_sync_poll(&wq->wait, EPOLLIN | EPOLLPRI |
3339 						EPOLLRDNORM | EPOLLRDBAND);
3340 	sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
3341 	rcu_read_unlock();
3342 }
3343 
3344 static void sock_def_write_space(struct sock *sk)
3345 {
3346 	struct socket_wq *wq;
3347 
3348 	rcu_read_lock();
3349 
3350 	/* Do not wake up a writer until he can make "significant"
3351 	 * progress.  --DaveM
3352 	 */
3353 	if (sock_writeable(sk)) {
3354 		wq = rcu_dereference(sk->sk_wq);
3355 		if (skwq_has_sleeper(wq))
3356 			wake_up_interruptible_sync_poll(&wq->wait, EPOLLOUT |
3357 						EPOLLWRNORM | EPOLLWRBAND);
3358 
3359 		/* Should agree with poll, otherwise some programs break */
3360 		sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
3361 	}
3362 
3363 	rcu_read_unlock();
3364 }
3365 
3366 /* An optimised version of sock_def_write_space(), should only be called
3367  * for SOCK_RCU_FREE sockets under RCU read section and after putting
3368  * ->sk_wmem_alloc.
3369  */
3370 static void sock_def_write_space_wfree(struct sock *sk)
3371 {
3372 	/* Do not wake up a writer until he can make "significant"
3373 	 * progress.  --DaveM
3374 	 */
3375 	if (sock_writeable(sk)) {
3376 		struct socket_wq *wq = rcu_dereference(sk->sk_wq);
3377 
3378 		/* rely on refcount_sub from sock_wfree() */
3379 		smp_mb__after_atomic();
3380 		if (wq && waitqueue_active(&wq->wait))
3381 			wake_up_interruptible_sync_poll(&wq->wait, EPOLLOUT |
3382 						EPOLLWRNORM | EPOLLWRBAND);
3383 
3384 		/* Should agree with poll, otherwise some programs break */
3385 		sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
3386 	}
3387 }
3388 
3389 static void sock_def_destruct(struct sock *sk)
3390 {
3391 }
3392 
3393 void sk_send_sigurg(struct sock *sk)
3394 {
3395 	if (sk->sk_socket && sk->sk_socket->file)
3396 		if (send_sigurg(&sk->sk_socket->file->f_owner))
3397 			sk_wake_async(sk, SOCK_WAKE_URG, POLL_PRI);
3398 }
3399 EXPORT_SYMBOL(sk_send_sigurg);
3400 
3401 void sk_reset_timer(struct sock *sk, struct timer_list* timer,
3402 		    unsigned long expires)
3403 {
3404 	if (!mod_timer(timer, expires))
3405 		sock_hold(sk);
3406 }
3407 EXPORT_SYMBOL(sk_reset_timer);
3408 
3409 void sk_stop_timer(struct sock *sk, struct timer_list* timer)
3410 {
3411 	if (del_timer(timer))
3412 		__sock_put(sk);
3413 }
3414 EXPORT_SYMBOL(sk_stop_timer);
3415 
3416 void sk_stop_timer_sync(struct sock *sk, struct timer_list *timer)
3417 {
3418 	if (del_timer_sync(timer))
3419 		__sock_put(sk);
3420 }
3421 EXPORT_SYMBOL(sk_stop_timer_sync);
3422 
3423 void sock_init_data_uid(struct socket *sock, struct sock *sk, kuid_t uid)
3424 {
3425 	sk_init_common(sk);
3426 	sk->sk_send_head	=	NULL;
3427 
3428 	timer_setup(&sk->sk_timer, NULL, 0);
3429 
3430 	sk->sk_allocation	=	GFP_KERNEL;
3431 	sk->sk_rcvbuf		=	READ_ONCE(sysctl_rmem_default);
3432 	sk->sk_sndbuf		=	READ_ONCE(sysctl_wmem_default);
3433 	sk->sk_state		=	TCP_CLOSE;
3434 	sk->sk_use_task_frag	=	true;
3435 	sk_set_socket(sk, sock);
3436 
3437 	sock_set_flag(sk, SOCK_ZAPPED);
3438 
3439 	if (sock) {
3440 		sk->sk_type	=	sock->type;
3441 		RCU_INIT_POINTER(sk->sk_wq, &sock->wq);
3442 		sock->sk	=	sk;
3443 	} else {
3444 		RCU_INIT_POINTER(sk->sk_wq, NULL);
3445 	}
3446 	sk->sk_uid	=	uid;
3447 
3448 	rwlock_init(&sk->sk_callback_lock);
3449 	if (sk->sk_kern_sock)
3450 		lockdep_set_class_and_name(
3451 			&sk->sk_callback_lock,
3452 			af_kern_callback_keys + sk->sk_family,
3453 			af_family_kern_clock_key_strings[sk->sk_family]);
3454 	else
3455 		lockdep_set_class_and_name(
3456 			&sk->sk_callback_lock,
3457 			af_callback_keys + sk->sk_family,
3458 			af_family_clock_key_strings[sk->sk_family]);
3459 
3460 	sk->sk_state_change	=	sock_def_wakeup;
3461 	sk->sk_data_ready	=	sock_def_readable;
3462 	sk->sk_write_space	=	sock_def_write_space;
3463 	sk->sk_error_report	=	sock_def_error_report;
3464 	sk->sk_destruct		=	sock_def_destruct;
3465 
3466 	sk->sk_frag.page	=	NULL;
3467 	sk->sk_frag.offset	=	0;
3468 	sk->sk_peek_off		=	-1;
3469 
3470 	sk->sk_peer_pid 	=	NULL;
3471 	sk->sk_peer_cred	=	NULL;
3472 	spin_lock_init(&sk->sk_peer_lock);
3473 
3474 	sk->sk_write_pending	=	0;
3475 	sk->sk_rcvlowat		=	1;
3476 	sk->sk_rcvtimeo		=	MAX_SCHEDULE_TIMEOUT;
3477 	sk->sk_sndtimeo		=	MAX_SCHEDULE_TIMEOUT;
3478 
3479 	sk->sk_stamp = SK_DEFAULT_STAMP;
3480 #if BITS_PER_LONG==32
3481 	seqlock_init(&sk->sk_stamp_seq);
3482 #endif
3483 	atomic_set(&sk->sk_zckey, 0);
3484 
3485 #ifdef CONFIG_NET_RX_BUSY_POLL
3486 	sk->sk_napi_id		=	0;
3487 	sk->sk_ll_usec		=	READ_ONCE(sysctl_net_busy_read);
3488 #endif
3489 
3490 	sk->sk_max_pacing_rate = ~0UL;
3491 	sk->sk_pacing_rate = ~0UL;
3492 	WRITE_ONCE(sk->sk_pacing_shift, 10);
3493 	sk->sk_incoming_cpu = -1;
3494 
3495 	sk_rx_queue_clear(sk);
3496 	/*
3497 	 * Before updating sk_refcnt, we must commit prior changes to memory
3498 	 * (Documentation/RCU/rculist_nulls.rst for details)
3499 	 */
3500 	smp_wmb();
3501 	refcount_set(&sk->sk_refcnt, 1);
3502 	atomic_set(&sk->sk_drops, 0);
3503 }
3504 EXPORT_SYMBOL(sock_init_data_uid);
3505 
3506 void sock_init_data(struct socket *sock, struct sock *sk)
3507 {
3508 	kuid_t uid = sock ?
3509 		SOCK_INODE(sock)->i_uid :
3510 		make_kuid(sock_net(sk)->user_ns, 0);
3511 
3512 	sock_init_data_uid(sock, sk, uid);
3513 }
3514 EXPORT_SYMBOL(sock_init_data);
3515 
3516 void lock_sock_nested(struct sock *sk, int subclass)
3517 {
3518 	/* The sk_lock has mutex_lock() semantics here. */
3519 	mutex_acquire(&sk->sk_lock.dep_map, subclass, 0, _RET_IP_);
3520 
3521 	might_sleep();
3522 	spin_lock_bh(&sk->sk_lock.slock);
3523 	if (sock_owned_by_user_nocheck(sk))
3524 		__lock_sock(sk);
3525 	sk->sk_lock.owned = 1;
3526 	spin_unlock_bh(&sk->sk_lock.slock);
3527 }
3528 EXPORT_SYMBOL(lock_sock_nested);
3529 
3530 void release_sock(struct sock *sk)
3531 {
3532 	spin_lock_bh(&sk->sk_lock.slock);
3533 	if (sk->sk_backlog.tail)
3534 		__release_sock(sk);
3535 
3536 	if (sk->sk_prot->release_cb)
3537 		INDIRECT_CALL_INET_1(sk->sk_prot->release_cb,
3538 				     tcp_release_cb, sk);
3539 
3540 	sock_release_ownership(sk);
3541 	if (waitqueue_active(&sk->sk_lock.wq))
3542 		wake_up(&sk->sk_lock.wq);
3543 	spin_unlock_bh(&sk->sk_lock.slock);
3544 }
3545 EXPORT_SYMBOL(release_sock);
3546 
3547 bool __lock_sock_fast(struct sock *sk) __acquires(&sk->sk_lock.slock)
3548 {
3549 	might_sleep();
3550 	spin_lock_bh(&sk->sk_lock.slock);
3551 
3552 	if (!sock_owned_by_user_nocheck(sk)) {
3553 		/*
3554 		 * Fast path return with bottom halves disabled and
3555 		 * sock::sk_lock.slock held.
3556 		 *
3557 		 * The 'mutex' is not contended and holding
3558 		 * sock::sk_lock.slock prevents all other lockers to
3559 		 * proceed so the corresponding unlock_sock_fast() can
3560 		 * avoid the slow path of release_sock() completely and
3561 		 * just release slock.
3562 		 *
3563 		 * From a semantical POV this is equivalent to 'acquiring'
3564 		 * the 'mutex', hence the corresponding lockdep
3565 		 * mutex_release() has to happen in the fast path of
3566 		 * unlock_sock_fast().
3567 		 */
3568 		return false;
3569 	}
3570 
3571 	__lock_sock(sk);
3572 	sk->sk_lock.owned = 1;
3573 	__acquire(&sk->sk_lock.slock);
3574 	spin_unlock_bh(&sk->sk_lock.slock);
3575 	return true;
3576 }
3577 EXPORT_SYMBOL(__lock_sock_fast);
3578 
3579 int sock_gettstamp(struct socket *sock, void __user *userstamp,
3580 		   bool timeval, bool time32)
3581 {
3582 	struct sock *sk = sock->sk;
3583 	struct timespec64 ts;
3584 
3585 	sock_enable_timestamp(sk, SOCK_TIMESTAMP);
3586 	ts = ktime_to_timespec64(sock_read_timestamp(sk));
3587 	if (ts.tv_sec == -1)
3588 		return -ENOENT;
3589 	if (ts.tv_sec == 0) {
3590 		ktime_t kt = ktime_get_real();
3591 		sock_write_timestamp(sk, kt);
3592 		ts = ktime_to_timespec64(kt);
3593 	}
3594 
3595 	if (timeval)
3596 		ts.tv_nsec /= 1000;
3597 
3598 #ifdef CONFIG_COMPAT_32BIT_TIME
3599 	if (time32)
3600 		return put_old_timespec32(&ts, userstamp);
3601 #endif
3602 #ifdef CONFIG_SPARC64
3603 	/* beware of padding in sparc64 timeval */
3604 	if (timeval && !in_compat_syscall()) {
3605 		struct __kernel_old_timeval __user tv = {
3606 			.tv_sec = ts.tv_sec,
3607 			.tv_usec = ts.tv_nsec,
3608 		};
3609 		if (copy_to_user(userstamp, &tv, sizeof(tv)))
3610 			return -EFAULT;
3611 		return 0;
3612 	}
3613 #endif
3614 	return put_timespec64(&ts, userstamp);
3615 }
3616 EXPORT_SYMBOL(sock_gettstamp);
3617 
3618 void sock_enable_timestamp(struct sock *sk, enum sock_flags flag)
3619 {
3620 	if (!sock_flag(sk, flag)) {
3621 		unsigned long previous_flags = sk->sk_flags;
3622 
3623 		sock_set_flag(sk, flag);
3624 		/*
3625 		 * we just set one of the two flags which require net
3626 		 * time stamping, but time stamping might have been on
3627 		 * already because of the other one
3628 		 */
3629 		if (sock_needs_netstamp(sk) &&
3630 		    !(previous_flags & SK_FLAGS_TIMESTAMP))
3631 			net_enable_timestamp();
3632 	}
3633 }
3634 
3635 int sock_recv_errqueue(struct sock *sk, struct msghdr *msg, int len,
3636 		       int level, int type)
3637 {
3638 	struct sock_exterr_skb *serr;
3639 	struct sk_buff *skb;
3640 	int copied, err;
3641 
3642 	err = -EAGAIN;
3643 	skb = sock_dequeue_err_skb(sk);
3644 	if (skb == NULL)
3645 		goto out;
3646 
3647 	copied = skb->len;
3648 	if (copied > len) {
3649 		msg->msg_flags |= MSG_TRUNC;
3650 		copied = len;
3651 	}
3652 	err = skb_copy_datagram_msg(skb, 0, msg, copied);
3653 	if (err)
3654 		goto out_free_skb;
3655 
3656 	sock_recv_timestamp(msg, sk, skb);
3657 
3658 	serr = SKB_EXT_ERR(skb);
3659 	put_cmsg(msg, level, type, sizeof(serr->ee), &serr->ee);
3660 
3661 	msg->msg_flags |= MSG_ERRQUEUE;
3662 	err = copied;
3663 
3664 out_free_skb:
3665 	kfree_skb(skb);
3666 out:
3667 	return err;
3668 }
3669 EXPORT_SYMBOL(sock_recv_errqueue);
3670 
3671 /*
3672  *	Get a socket option on an socket.
3673  *
3674  *	FIX: POSIX 1003.1g is very ambiguous here. It states that
3675  *	asynchronous errors should be reported by getsockopt. We assume
3676  *	this means if you specify SO_ERROR (otherwise whats the point of it).
3677  */
3678 int sock_common_getsockopt(struct socket *sock, int level, int optname,
3679 			   char __user *optval, int __user *optlen)
3680 {
3681 	struct sock *sk = sock->sk;
3682 
3683 	/* IPV6_ADDRFORM can change sk->sk_prot under us. */
3684 	return READ_ONCE(sk->sk_prot)->getsockopt(sk, level, optname, optval, optlen);
3685 }
3686 EXPORT_SYMBOL(sock_common_getsockopt);
3687 
3688 int sock_common_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
3689 			int flags)
3690 {
3691 	struct sock *sk = sock->sk;
3692 	int addr_len = 0;
3693 	int err;
3694 
3695 	err = sk->sk_prot->recvmsg(sk, msg, size, flags, &addr_len);
3696 	if (err >= 0)
3697 		msg->msg_namelen = addr_len;
3698 	return err;
3699 }
3700 EXPORT_SYMBOL(sock_common_recvmsg);
3701 
3702 /*
3703  *	Set socket options on an inet socket.
3704  */
3705 int sock_common_setsockopt(struct socket *sock, int level, int optname,
3706 			   sockptr_t optval, unsigned int optlen)
3707 {
3708 	struct sock *sk = sock->sk;
3709 
3710 	/* IPV6_ADDRFORM can change sk->sk_prot under us. */
3711 	return READ_ONCE(sk->sk_prot)->setsockopt(sk, level, optname, optval, optlen);
3712 }
3713 EXPORT_SYMBOL(sock_common_setsockopt);
3714 
3715 void sk_common_release(struct sock *sk)
3716 {
3717 	if (sk->sk_prot->destroy)
3718 		sk->sk_prot->destroy(sk);
3719 
3720 	/*
3721 	 * Observation: when sk_common_release is called, processes have
3722 	 * no access to socket. But net still has.
3723 	 * Step one, detach it from networking:
3724 	 *
3725 	 * A. Remove from hash tables.
3726 	 */
3727 
3728 	sk->sk_prot->unhash(sk);
3729 
3730 	/*
3731 	 * In this point socket cannot receive new packets, but it is possible
3732 	 * that some packets are in flight because some CPU runs receiver and
3733 	 * did hash table lookup before we unhashed socket. They will achieve
3734 	 * receive queue and will be purged by socket destructor.
3735 	 *
3736 	 * Also we still have packets pending on receive queue and probably,
3737 	 * our own packets waiting in device queues. sock_destroy will drain
3738 	 * receive queue, but transmitted packets will delay socket destruction
3739 	 * until the last reference will be released.
3740 	 */
3741 
3742 	sock_orphan(sk);
3743 
3744 	xfrm_sk_free_policy(sk);
3745 
3746 	sock_put(sk);
3747 }
3748 EXPORT_SYMBOL(sk_common_release);
3749 
3750 void sk_get_meminfo(const struct sock *sk, u32 *mem)
3751 {
3752 	memset(mem, 0, sizeof(*mem) * SK_MEMINFO_VARS);
3753 
3754 	mem[SK_MEMINFO_RMEM_ALLOC] = sk_rmem_alloc_get(sk);
3755 	mem[SK_MEMINFO_RCVBUF] = READ_ONCE(sk->sk_rcvbuf);
3756 	mem[SK_MEMINFO_WMEM_ALLOC] = sk_wmem_alloc_get(sk);
3757 	mem[SK_MEMINFO_SNDBUF] = READ_ONCE(sk->sk_sndbuf);
3758 	mem[SK_MEMINFO_FWD_ALLOC] = sk_forward_alloc_get(sk);
3759 	mem[SK_MEMINFO_WMEM_QUEUED] = READ_ONCE(sk->sk_wmem_queued);
3760 	mem[SK_MEMINFO_OPTMEM] = atomic_read(&sk->sk_omem_alloc);
3761 	mem[SK_MEMINFO_BACKLOG] = READ_ONCE(sk->sk_backlog.len);
3762 	mem[SK_MEMINFO_DROPS] = atomic_read(&sk->sk_drops);
3763 }
3764 
3765 #ifdef CONFIG_PROC_FS
3766 static DECLARE_BITMAP(proto_inuse_idx, PROTO_INUSE_NR);
3767 
3768 int sock_prot_inuse_get(struct net *net, struct proto *prot)
3769 {
3770 	int cpu, idx = prot->inuse_idx;
3771 	int res = 0;
3772 
3773 	for_each_possible_cpu(cpu)
3774 		res += per_cpu_ptr(net->core.prot_inuse, cpu)->val[idx];
3775 
3776 	return res >= 0 ? res : 0;
3777 }
3778 EXPORT_SYMBOL_GPL(sock_prot_inuse_get);
3779 
3780 int sock_inuse_get(struct net *net)
3781 {
3782 	int cpu, res = 0;
3783 
3784 	for_each_possible_cpu(cpu)
3785 		res += per_cpu_ptr(net->core.prot_inuse, cpu)->all;
3786 
3787 	return res;
3788 }
3789 
3790 EXPORT_SYMBOL_GPL(sock_inuse_get);
3791 
3792 static int __net_init sock_inuse_init_net(struct net *net)
3793 {
3794 	net->core.prot_inuse = alloc_percpu(struct prot_inuse);
3795 	if (net->core.prot_inuse == NULL)
3796 		return -ENOMEM;
3797 	return 0;
3798 }
3799 
3800 static void __net_exit sock_inuse_exit_net(struct net *net)
3801 {
3802 	free_percpu(net->core.prot_inuse);
3803 }
3804 
3805 static struct pernet_operations net_inuse_ops = {
3806 	.init = sock_inuse_init_net,
3807 	.exit = sock_inuse_exit_net,
3808 };
3809 
3810 static __init int net_inuse_init(void)
3811 {
3812 	if (register_pernet_subsys(&net_inuse_ops))
3813 		panic("Cannot initialize net inuse counters");
3814 
3815 	return 0;
3816 }
3817 
3818 core_initcall(net_inuse_init);
3819 
3820 static int assign_proto_idx(struct proto *prot)
3821 {
3822 	prot->inuse_idx = find_first_zero_bit(proto_inuse_idx, PROTO_INUSE_NR);
3823 
3824 	if (unlikely(prot->inuse_idx == PROTO_INUSE_NR - 1)) {
3825 		pr_err("PROTO_INUSE_NR exhausted\n");
3826 		return -ENOSPC;
3827 	}
3828 
3829 	set_bit(prot->inuse_idx, proto_inuse_idx);
3830 	return 0;
3831 }
3832 
3833 static void release_proto_idx(struct proto *prot)
3834 {
3835 	if (prot->inuse_idx != PROTO_INUSE_NR - 1)
3836 		clear_bit(prot->inuse_idx, proto_inuse_idx);
3837 }
3838 #else
3839 static inline int assign_proto_idx(struct proto *prot)
3840 {
3841 	return 0;
3842 }
3843 
3844 static inline void release_proto_idx(struct proto *prot)
3845 {
3846 }
3847 
3848 #endif
3849 
3850 static void tw_prot_cleanup(struct timewait_sock_ops *twsk_prot)
3851 {
3852 	if (!twsk_prot)
3853 		return;
3854 	kfree(twsk_prot->twsk_slab_name);
3855 	twsk_prot->twsk_slab_name = NULL;
3856 	kmem_cache_destroy(twsk_prot->twsk_slab);
3857 	twsk_prot->twsk_slab = NULL;
3858 }
3859 
3860 static int tw_prot_init(const struct proto *prot)
3861 {
3862 	struct timewait_sock_ops *twsk_prot = prot->twsk_prot;
3863 
3864 	if (!twsk_prot)
3865 		return 0;
3866 
3867 	twsk_prot->twsk_slab_name = kasprintf(GFP_KERNEL, "tw_sock_%s",
3868 					      prot->name);
3869 	if (!twsk_prot->twsk_slab_name)
3870 		return -ENOMEM;
3871 
3872 	twsk_prot->twsk_slab =
3873 		kmem_cache_create(twsk_prot->twsk_slab_name,
3874 				  twsk_prot->twsk_obj_size, 0,
3875 				  SLAB_ACCOUNT | prot->slab_flags,
3876 				  NULL);
3877 	if (!twsk_prot->twsk_slab) {
3878 		pr_crit("%s: Can't create timewait sock SLAB cache!\n",
3879 			prot->name);
3880 		return -ENOMEM;
3881 	}
3882 
3883 	return 0;
3884 }
3885 
3886 static void req_prot_cleanup(struct request_sock_ops *rsk_prot)
3887 {
3888 	if (!rsk_prot)
3889 		return;
3890 	kfree(rsk_prot->slab_name);
3891 	rsk_prot->slab_name = NULL;
3892 	kmem_cache_destroy(rsk_prot->slab);
3893 	rsk_prot->slab = NULL;
3894 }
3895 
3896 static int req_prot_init(const struct proto *prot)
3897 {
3898 	struct request_sock_ops *rsk_prot = prot->rsk_prot;
3899 
3900 	if (!rsk_prot)
3901 		return 0;
3902 
3903 	rsk_prot->slab_name = kasprintf(GFP_KERNEL, "request_sock_%s",
3904 					prot->name);
3905 	if (!rsk_prot->slab_name)
3906 		return -ENOMEM;
3907 
3908 	rsk_prot->slab = kmem_cache_create(rsk_prot->slab_name,
3909 					   rsk_prot->obj_size, 0,
3910 					   SLAB_ACCOUNT | prot->slab_flags,
3911 					   NULL);
3912 
3913 	if (!rsk_prot->slab) {
3914 		pr_crit("%s: Can't create request sock SLAB cache!\n",
3915 			prot->name);
3916 		return -ENOMEM;
3917 	}
3918 	return 0;
3919 }
3920 
3921 int proto_register(struct proto *prot, int alloc_slab)
3922 {
3923 	int ret = -ENOBUFS;
3924 
3925 	if (prot->memory_allocated && !prot->sysctl_mem) {
3926 		pr_err("%s: missing sysctl_mem\n", prot->name);
3927 		return -EINVAL;
3928 	}
3929 	if (prot->memory_allocated && !prot->per_cpu_fw_alloc) {
3930 		pr_err("%s: missing per_cpu_fw_alloc\n", prot->name);
3931 		return -EINVAL;
3932 	}
3933 	if (alloc_slab) {
3934 		prot->slab = kmem_cache_create_usercopy(prot->name,
3935 					prot->obj_size, 0,
3936 					SLAB_HWCACHE_ALIGN | SLAB_ACCOUNT |
3937 					prot->slab_flags,
3938 					prot->useroffset, prot->usersize,
3939 					NULL);
3940 
3941 		if (prot->slab == NULL) {
3942 			pr_crit("%s: Can't create sock SLAB cache!\n",
3943 				prot->name);
3944 			goto out;
3945 		}
3946 
3947 		if (req_prot_init(prot))
3948 			goto out_free_request_sock_slab;
3949 
3950 		if (tw_prot_init(prot))
3951 			goto out_free_timewait_sock_slab;
3952 	}
3953 
3954 	mutex_lock(&proto_list_mutex);
3955 	ret = assign_proto_idx(prot);
3956 	if (ret) {
3957 		mutex_unlock(&proto_list_mutex);
3958 		goto out_free_timewait_sock_slab;
3959 	}
3960 	list_add(&prot->node, &proto_list);
3961 	mutex_unlock(&proto_list_mutex);
3962 	return ret;
3963 
3964 out_free_timewait_sock_slab:
3965 	if (alloc_slab)
3966 		tw_prot_cleanup(prot->twsk_prot);
3967 out_free_request_sock_slab:
3968 	if (alloc_slab) {
3969 		req_prot_cleanup(prot->rsk_prot);
3970 
3971 		kmem_cache_destroy(prot->slab);
3972 		prot->slab = NULL;
3973 	}
3974 out:
3975 	return ret;
3976 }
3977 EXPORT_SYMBOL(proto_register);
3978 
3979 void proto_unregister(struct proto *prot)
3980 {
3981 	mutex_lock(&proto_list_mutex);
3982 	release_proto_idx(prot);
3983 	list_del(&prot->node);
3984 	mutex_unlock(&proto_list_mutex);
3985 
3986 	kmem_cache_destroy(prot->slab);
3987 	prot->slab = NULL;
3988 
3989 	req_prot_cleanup(prot->rsk_prot);
3990 	tw_prot_cleanup(prot->twsk_prot);
3991 }
3992 EXPORT_SYMBOL(proto_unregister);
3993 
3994 int sock_load_diag_module(int family, int protocol)
3995 {
3996 	if (!protocol) {
3997 		if (!sock_is_registered(family))
3998 			return -ENOENT;
3999 
4000 		return request_module("net-pf-%d-proto-%d-type-%d", PF_NETLINK,
4001 				      NETLINK_SOCK_DIAG, family);
4002 	}
4003 
4004 #ifdef CONFIG_INET
4005 	if (family == AF_INET &&
4006 	    protocol != IPPROTO_RAW &&
4007 	    protocol < MAX_INET_PROTOS &&
4008 	    !rcu_access_pointer(inet_protos[protocol]))
4009 		return -ENOENT;
4010 #endif
4011 
4012 	return request_module("net-pf-%d-proto-%d-type-%d-%d", PF_NETLINK,
4013 			      NETLINK_SOCK_DIAG, family, protocol);
4014 }
4015 EXPORT_SYMBOL(sock_load_diag_module);
4016 
4017 #ifdef CONFIG_PROC_FS
4018 static void *proto_seq_start(struct seq_file *seq, loff_t *pos)
4019 	__acquires(proto_list_mutex)
4020 {
4021 	mutex_lock(&proto_list_mutex);
4022 	return seq_list_start_head(&proto_list, *pos);
4023 }
4024 
4025 static void *proto_seq_next(struct seq_file *seq, void *v, loff_t *pos)
4026 {
4027 	return seq_list_next(v, &proto_list, pos);
4028 }
4029 
4030 static void proto_seq_stop(struct seq_file *seq, void *v)
4031 	__releases(proto_list_mutex)
4032 {
4033 	mutex_unlock(&proto_list_mutex);
4034 }
4035 
4036 static char proto_method_implemented(const void *method)
4037 {
4038 	return method == NULL ? 'n' : 'y';
4039 }
4040 static long sock_prot_memory_allocated(struct proto *proto)
4041 {
4042 	return proto->memory_allocated != NULL ? proto_memory_allocated(proto) : -1L;
4043 }
4044 
4045 static const char *sock_prot_memory_pressure(struct proto *proto)
4046 {
4047 	return proto->memory_pressure != NULL ?
4048 	proto_memory_pressure(proto) ? "yes" : "no" : "NI";
4049 }
4050 
4051 static void proto_seq_printf(struct seq_file *seq, struct proto *proto)
4052 {
4053 
4054 	seq_printf(seq, "%-9s %4u %6d  %6ld   %-3s %6u   %-3s  %-10s "
4055 			"%2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c\n",
4056 		   proto->name,
4057 		   proto->obj_size,
4058 		   sock_prot_inuse_get(seq_file_net(seq), proto),
4059 		   sock_prot_memory_allocated(proto),
4060 		   sock_prot_memory_pressure(proto),
4061 		   proto->max_header,
4062 		   proto->slab == NULL ? "no" : "yes",
4063 		   module_name(proto->owner),
4064 		   proto_method_implemented(proto->close),
4065 		   proto_method_implemented(proto->connect),
4066 		   proto_method_implemented(proto->disconnect),
4067 		   proto_method_implemented(proto->accept),
4068 		   proto_method_implemented(proto->ioctl),
4069 		   proto_method_implemented(proto->init),
4070 		   proto_method_implemented(proto->destroy),
4071 		   proto_method_implemented(proto->shutdown),
4072 		   proto_method_implemented(proto->setsockopt),
4073 		   proto_method_implemented(proto->getsockopt),
4074 		   proto_method_implemented(proto->sendmsg),
4075 		   proto_method_implemented(proto->recvmsg),
4076 		   proto_method_implemented(proto->bind),
4077 		   proto_method_implemented(proto->backlog_rcv),
4078 		   proto_method_implemented(proto->hash),
4079 		   proto_method_implemented(proto->unhash),
4080 		   proto_method_implemented(proto->get_port),
4081 		   proto_method_implemented(proto->enter_memory_pressure));
4082 }
4083 
4084 static int proto_seq_show(struct seq_file *seq, void *v)
4085 {
4086 	if (v == &proto_list)
4087 		seq_printf(seq, "%-9s %-4s %-8s %-6s %-5s %-7s %-4s %-10s %s",
4088 			   "protocol",
4089 			   "size",
4090 			   "sockets",
4091 			   "memory",
4092 			   "press",
4093 			   "maxhdr",
4094 			   "slab",
4095 			   "module",
4096 			   "cl co di ac io in de sh ss gs se re bi br ha uh gp em\n");
4097 	else
4098 		proto_seq_printf(seq, list_entry(v, struct proto, node));
4099 	return 0;
4100 }
4101 
4102 static const struct seq_operations proto_seq_ops = {
4103 	.start  = proto_seq_start,
4104 	.next   = proto_seq_next,
4105 	.stop   = proto_seq_stop,
4106 	.show   = proto_seq_show,
4107 };
4108 
4109 static __net_init int proto_init_net(struct net *net)
4110 {
4111 	if (!proc_create_net("protocols", 0444, net->proc_net, &proto_seq_ops,
4112 			sizeof(struct seq_net_private)))
4113 		return -ENOMEM;
4114 
4115 	return 0;
4116 }
4117 
4118 static __net_exit void proto_exit_net(struct net *net)
4119 {
4120 	remove_proc_entry("protocols", net->proc_net);
4121 }
4122 
4123 
4124 static __net_initdata struct pernet_operations proto_net_ops = {
4125 	.init = proto_init_net,
4126 	.exit = proto_exit_net,
4127 };
4128 
4129 static int __init proto_init(void)
4130 {
4131 	return register_pernet_subsys(&proto_net_ops);
4132 }
4133 
4134 subsys_initcall(proto_init);
4135 
4136 #endif /* PROC_FS */
4137 
4138 #ifdef CONFIG_NET_RX_BUSY_POLL
4139 bool sk_busy_loop_end(void *p, unsigned long start_time)
4140 {
4141 	struct sock *sk = p;
4142 
4143 	return !skb_queue_empty_lockless(&sk->sk_receive_queue) ||
4144 	       sk_busy_loop_timeout(sk, start_time);
4145 }
4146 EXPORT_SYMBOL(sk_busy_loop_end);
4147 #endif /* CONFIG_NET_RX_BUSY_POLL */
4148 
4149 int sock_bind_add(struct sock *sk, struct sockaddr *addr, int addr_len)
4150 {
4151 	if (!sk->sk_prot->bind_add)
4152 		return -EOPNOTSUPP;
4153 	return sk->sk_prot->bind_add(sk, addr, addr_len);
4154 }
4155 EXPORT_SYMBOL(sock_bind_add);
4156 
4157 /* Copy 'size' bytes from userspace and return `size` back to userspace */
4158 int sock_ioctl_inout(struct sock *sk, unsigned int cmd,
4159 		     void __user *arg, void *karg, size_t size)
4160 {
4161 	int ret;
4162 
4163 	if (copy_from_user(karg, arg, size))
4164 		return -EFAULT;
4165 
4166 	ret = READ_ONCE(sk->sk_prot)->ioctl(sk, cmd, karg);
4167 	if (ret)
4168 		return ret;
4169 
4170 	if (copy_to_user(arg, karg, size))
4171 		return -EFAULT;
4172 
4173 	return 0;
4174 }
4175 EXPORT_SYMBOL(sock_ioctl_inout);
4176 
4177 /* This is the most common ioctl prep function, where the result (4 bytes) is
4178  * copied back to userspace if the ioctl() returns successfully. No input is
4179  * copied from userspace as input argument.
4180  */
4181 static int sock_ioctl_out(struct sock *sk, unsigned int cmd, void __user *arg)
4182 {
4183 	int ret, karg = 0;
4184 
4185 	ret = READ_ONCE(sk->sk_prot)->ioctl(sk, cmd, &karg);
4186 	if (ret)
4187 		return ret;
4188 
4189 	return put_user(karg, (int __user *)arg);
4190 }
4191 
4192 /* A wrapper around sock ioctls, which copies the data from userspace
4193  * (depending on the protocol/ioctl), and copies back the result to userspace.
4194  * The main motivation for this function is to pass kernel memory to the
4195  * protocol ioctl callbacks, instead of userspace memory.
4196  */
4197 int sk_ioctl(struct sock *sk, unsigned int cmd, void __user *arg)
4198 {
4199 	int rc = 1;
4200 
4201 	if (sk->sk_type == SOCK_RAW && sk->sk_family == AF_INET)
4202 		rc = ipmr_sk_ioctl(sk, cmd, arg);
4203 	else if (sk->sk_type == SOCK_RAW && sk->sk_family == AF_INET6)
4204 		rc = ip6mr_sk_ioctl(sk, cmd, arg);
4205 	else if (sk_is_phonet(sk))
4206 		rc = phonet_sk_ioctl(sk, cmd, arg);
4207 
4208 	/* If ioctl was processed, returns its value */
4209 	if (rc <= 0)
4210 		return rc;
4211 
4212 	/* Otherwise call the default handler */
4213 	return sock_ioctl_out(sk, cmd, arg);
4214 }
4215 EXPORT_SYMBOL(sk_ioctl);
4216