xref: /linux/net/core/sock.c (revision b1a54551dd9ed5ef1763b97b35a0999ca002b95c)
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 int sysctl_tstamp_allow_data __read_mostly = 1;
287 
288 DEFINE_STATIC_KEY_FALSE(memalloc_socks_key);
289 EXPORT_SYMBOL_GPL(memalloc_socks_key);
290 
291 /**
292  * sk_set_memalloc - sets %SOCK_MEMALLOC
293  * @sk: socket to set it on
294  *
295  * Set %SOCK_MEMALLOC on a socket for access to emergency reserves.
296  * It's the responsibility of the admin to adjust min_free_kbytes
297  * to meet the requirements
298  */
299 void sk_set_memalloc(struct sock *sk)
300 {
301 	sock_set_flag(sk, SOCK_MEMALLOC);
302 	sk->sk_allocation |= __GFP_MEMALLOC;
303 	static_branch_inc(&memalloc_socks_key);
304 }
305 EXPORT_SYMBOL_GPL(sk_set_memalloc);
306 
307 void sk_clear_memalloc(struct sock *sk)
308 {
309 	sock_reset_flag(sk, SOCK_MEMALLOC);
310 	sk->sk_allocation &= ~__GFP_MEMALLOC;
311 	static_branch_dec(&memalloc_socks_key);
312 
313 	/*
314 	 * SOCK_MEMALLOC is allowed to ignore rmem limits to ensure forward
315 	 * progress of swapping. SOCK_MEMALLOC may be cleared while
316 	 * it has rmem allocations due to the last swapfile being deactivated
317 	 * but there is a risk that the socket is unusable due to exceeding
318 	 * the rmem limits. Reclaim the reserves and obey rmem limits again.
319 	 */
320 	sk_mem_reclaim(sk);
321 }
322 EXPORT_SYMBOL_GPL(sk_clear_memalloc);
323 
324 int __sk_backlog_rcv(struct sock *sk, struct sk_buff *skb)
325 {
326 	int ret;
327 	unsigned int noreclaim_flag;
328 
329 	/* these should have been dropped before queueing */
330 	BUG_ON(!sock_flag(sk, SOCK_MEMALLOC));
331 
332 	noreclaim_flag = memalloc_noreclaim_save();
333 	ret = INDIRECT_CALL_INET(sk->sk_backlog_rcv,
334 				 tcp_v6_do_rcv,
335 				 tcp_v4_do_rcv,
336 				 sk, skb);
337 	memalloc_noreclaim_restore(noreclaim_flag);
338 
339 	return ret;
340 }
341 EXPORT_SYMBOL(__sk_backlog_rcv);
342 
343 void sk_error_report(struct sock *sk)
344 {
345 	sk->sk_error_report(sk);
346 
347 	switch (sk->sk_family) {
348 	case AF_INET:
349 		fallthrough;
350 	case AF_INET6:
351 		trace_inet_sk_error_report(sk);
352 		break;
353 	default:
354 		break;
355 	}
356 }
357 EXPORT_SYMBOL(sk_error_report);
358 
359 int sock_get_timeout(long timeo, void *optval, bool old_timeval)
360 {
361 	struct __kernel_sock_timeval tv;
362 
363 	if (timeo == MAX_SCHEDULE_TIMEOUT) {
364 		tv.tv_sec = 0;
365 		tv.tv_usec = 0;
366 	} else {
367 		tv.tv_sec = timeo / HZ;
368 		tv.tv_usec = ((timeo % HZ) * USEC_PER_SEC) / HZ;
369 	}
370 
371 	if (old_timeval && in_compat_syscall() && !COMPAT_USE_64BIT_TIME) {
372 		struct old_timeval32 tv32 = { tv.tv_sec, tv.tv_usec };
373 		*(struct old_timeval32 *)optval = tv32;
374 		return sizeof(tv32);
375 	}
376 
377 	if (old_timeval) {
378 		struct __kernel_old_timeval old_tv;
379 		old_tv.tv_sec = tv.tv_sec;
380 		old_tv.tv_usec = tv.tv_usec;
381 		*(struct __kernel_old_timeval *)optval = old_tv;
382 		return sizeof(old_tv);
383 	}
384 
385 	*(struct __kernel_sock_timeval *)optval = tv;
386 	return sizeof(tv);
387 }
388 EXPORT_SYMBOL(sock_get_timeout);
389 
390 int sock_copy_user_timeval(struct __kernel_sock_timeval *tv,
391 			   sockptr_t optval, int optlen, bool old_timeval)
392 {
393 	if (old_timeval && in_compat_syscall() && !COMPAT_USE_64BIT_TIME) {
394 		struct old_timeval32 tv32;
395 
396 		if (optlen < sizeof(tv32))
397 			return -EINVAL;
398 
399 		if (copy_from_sockptr(&tv32, optval, sizeof(tv32)))
400 			return -EFAULT;
401 		tv->tv_sec = tv32.tv_sec;
402 		tv->tv_usec = tv32.tv_usec;
403 	} else if (old_timeval) {
404 		struct __kernel_old_timeval old_tv;
405 
406 		if (optlen < sizeof(old_tv))
407 			return -EINVAL;
408 		if (copy_from_sockptr(&old_tv, optval, sizeof(old_tv)))
409 			return -EFAULT;
410 		tv->tv_sec = old_tv.tv_sec;
411 		tv->tv_usec = old_tv.tv_usec;
412 	} else {
413 		if (optlen < sizeof(*tv))
414 			return -EINVAL;
415 		if (copy_from_sockptr(tv, optval, sizeof(*tv)))
416 			return -EFAULT;
417 	}
418 
419 	return 0;
420 }
421 EXPORT_SYMBOL(sock_copy_user_timeval);
422 
423 static int sock_set_timeout(long *timeo_p, sockptr_t optval, int optlen,
424 			    bool old_timeval)
425 {
426 	struct __kernel_sock_timeval tv;
427 	int err = sock_copy_user_timeval(&tv, optval, optlen, old_timeval);
428 	long val;
429 
430 	if (err)
431 		return err;
432 
433 	if (tv.tv_usec < 0 || tv.tv_usec >= USEC_PER_SEC)
434 		return -EDOM;
435 
436 	if (tv.tv_sec < 0) {
437 		static int warned __read_mostly;
438 
439 		WRITE_ONCE(*timeo_p, 0);
440 		if (warned < 10 && net_ratelimit()) {
441 			warned++;
442 			pr_info("%s: `%s' (pid %d) tries to set negative timeout\n",
443 				__func__, current->comm, task_pid_nr(current));
444 		}
445 		return 0;
446 	}
447 	val = MAX_SCHEDULE_TIMEOUT;
448 	if ((tv.tv_sec || tv.tv_usec) &&
449 	    (tv.tv_sec < (MAX_SCHEDULE_TIMEOUT / HZ - 1)))
450 		val = tv.tv_sec * HZ + DIV_ROUND_UP((unsigned long)tv.tv_usec,
451 						    USEC_PER_SEC / HZ);
452 	WRITE_ONCE(*timeo_p, val);
453 	return 0;
454 }
455 
456 static bool sock_needs_netstamp(const struct sock *sk)
457 {
458 	switch (sk->sk_family) {
459 	case AF_UNSPEC:
460 	case AF_UNIX:
461 		return false;
462 	default:
463 		return true;
464 	}
465 }
466 
467 static void sock_disable_timestamp(struct sock *sk, unsigned long flags)
468 {
469 	if (sk->sk_flags & flags) {
470 		sk->sk_flags &= ~flags;
471 		if (sock_needs_netstamp(sk) &&
472 		    !(sk->sk_flags & SK_FLAGS_TIMESTAMP))
473 			net_disable_timestamp();
474 	}
475 }
476 
477 
478 int __sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
479 {
480 	unsigned long flags;
481 	struct sk_buff_head *list = &sk->sk_receive_queue;
482 
483 	if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf) {
484 		atomic_inc(&sk->sk_drops);
485 		trace_sock_rcvqueue_full(sk, skb);
486 		return -ENOMEM;
487 	}
488 
489 	if (!sk_rmem_schedule(sk, skb, skb->truesize)) {
490 		atomic_inc(&sk->sk_drops);
491 		return -ENOBUFS;
492 	}
493 
494 	skb->dev = NULL;
495 	skb_set_owner_r(skb, sk);
496 
497 	/* we escape from rcu protected region, make sure we dont leak
498 	 * a norefcounted dst
499 	 */
500 	skb_dst_force(skb);
501 
502 	spin_lock_irqsave(&list->lock, flags);
503 	sock_skb_set_dropcount(sk, skb);
504 	__skb_queue_tail(list, skb);
505 	spin_unlock_irqrestore(&list->lock, flags);
506 
507 	if (!sock_flag(sk, SOCK_DEAD))
508 		sk->sk_data_ready(sk);
509 	return 0;
510 }
511 EXPORT_SYMBOL(__sock_queue_rcv_skb);
512 
513 int sock_queue_rcv_skb_reason(struct sock *sk, struct sk_buff *skb,
514 			      enum skb_drop_reason *reason)
515 {
516 	enum skb_drop_reason drop_reason;
517 	int err;
518 
519 	err = sk_filter(sk, skb);
520 	if (err) {
521 		drop_reason = SKB_DROP_REASON_SOCKET_FILTER;
522 		goto out;
523 	}
524 	err = __sock_queue_rcv_skb(sk, skb);
525 	switch (err) {
526 	case -ENOMEM:
527 		drop_reason = SKB_DROP_REASON_SOCKET_RCVBUFF;
528 		break;
529 	case -ENOBUFS:
530 		drop_reason = SKB_DROP_REASON_PROTO_MEM;
531 		break;
532 	default:
533 		drop_reason = SKB_NOT_DROPPED_YET;
534 		break;
535 	}
536 out:
537 	if (reason)
538 		*reason = drop_reason;
539 	return err;
540 }
541 EXPORT_SYMBOL(sock_queue_rcv_skb_reason);
542 
543 int __sk_receive_skb(struct sock *sk, struct sk_buff *skb,
544 		     const int nested, unsigned int trim_cap, bool refcounted)
545 {
546 	int rc = NET_RX_SUCCESS;
547 
548 	if (sk_filter_trim_cap(sk, skb, trim_cap))
549 		goto discard_and_relse;
550 
551 	skb->dev = NULL;
552 
553 	if (sk_rcvqueues_full(sk, sk->sk_rcvbuf)) {
554 		atomic_inc(&sk->sk_drops);
555 		goto discard_and_relse;
556 	}
557 	if (nested)
558 		bh_lock_sock_nested(sk);
559 	else
560 		bh_lock_sock(sk);
561 	if (!sock_owned_by_user(sk)) {
562 		/*
563 		 * trylock + unlock semantics:
564 		 */
565 		mutex_acquire(&sk->sk_lock.dep_map, 0, 1, _RET_IP_);
566 
567 		rc = sk_backlog_rcv(sk, skb);
568 
569 		mutex_release(&sk->sk_lock.dep_map, _RET_IP_);
570 	} else if (sk_add_backlog(sk, skb, READ_ONCE(sk->sk_rcvbuf))) {
571 		bh_unlock_sock(sk);
572 		atomic_inc(&sk->sk_drops);
573 		goto discard_and_relse;
574 	}
575 
576 	bh_unlock_sock(sk);
577 out:
578 	if (refcounted)
579 		sock_put(sk);
580 	return rc;
581 discard_and_relse:
582 	kfree_skb(skb);
583 	goto out;
584 }
585 EXPORT_SYMBOL(__sk_receive_skb);
586 
587 INDIRECT_CALLABLE_DECLARE(struct dst_entry *ip6_dst_check(struct dst_entry *,
588 							  u32));
589 INDIRECT_CALLABLE_DECLARE(struct dst_entry *ipv4_dst_check(struct dst_entry *,
590 							   u32));
591 struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie)
592 {
593 	struct dst_entry *dst = __sk_dst_get(sk);
594 
595 	if (dst && dst->obsolete &&
596 	    INDIRECT_CALL_INET(dst->ops->check, ip6_dst_check, ipv4_dst_check,
597 			       dst, cookie) == NULL) {
598 		sk_tx_queue_clear(sk);
599 		WRITE_ONCE(sk->sk_dst_pending_confirm, 0);
600 		RCU_INIT_POINTER(sk->sk_dst_cache, NULL);
601 		dst_release(dst);
602 		return NULL;
603 	}
604 
605 	return dst;
606 }
607 EXPORT_SYMBOL(__sk_dst_check);
608 
609 struct dst_entry *sk_dst_check(struct sock *sk, u32 cookie)
610 {
611 	struct dst_entry *dst = sk_dst_get(sk);
612 
613 	if (dst && dst->obsolete &&
614 	    INDIRECT_CALL_INET(dst->ops->check, ip6_dst_check, ipv4_dst_check,
615 			       dst, cookie) == NULL) {
616 		sk_dst_reset(sk);
617 		dst_release(dst);
618 		return NULL;
619 	}
620 
621 	return dst;
622 }
623 EXPORT_SYMBOL(sk_dst_check);
624 
625 static int sock_bindtoindex_locked(struct sock *sk, int ifindex)
626 {
627 	int ret = -ENOPROTOOPT;
628 #ifdef CONFIG_NETDEVICES
629 	struct net *net = sock_net(sk);
630 
631 	/* Sorry... */
632 	ret = -EPERM;
633 	if (sk->sk_bound_dev_if && !ns_capable(net->user_ns, CAP_NET_RAW))
634 		goto out;
635 
636 	ret = -EINVAL;
637 	if (ifindex < 0)
638 		goto out;
639 
640 	/* Paired with all READ_ONCE() done locklessly. */
641 	WRITE_ONCE(sk->sk_bound_dev_if, ifindex);
642 
643 	if (sk->sk_prot->rehash)
644 		sk->sk_prot->rehash(sk);
645 	sk_dst_reset(sk);
646 
647 	ret = 0;
648 
649 out:
650 #endif
651 
652 	return ret;
653 }
654 
655 int sock_bindtoindex(struct sock *sk, int ifindex, bool lock_sk)
656 {
657 	int ret;
658 
659 	if (lock_sk)
660 		lock_sock(sk);
661 	ret = sock_bindtoindex_locked(sk, ifindex);
662 	if (lock_sk)
663 		release_sock(sk);
664 
665 	return ret;
666 }
667 EXPORT_SYMBOL(sock_bindtoindex);
668 
669 static int sock_setbindtodevice(struct sock *sk, sockptr_t optval, int optlen)
670 {
671 	int ret = -ENOPROTOOPT;
672 #ifdef CONFIG_NETDEVICES
673 	struct net *net = sock_net(sk);
674 	char devname[IFNAMSIZ];
675 	int index;
676 
677 	ret = -EINVAL;
678 	if (optlen < 0)
679 		goto out;
680 
681 	/* Bind this socket to a particular device like "eth0",
682 	 * as specified in the passed interface name. If the
683 	 * name is "" or the option length is zero the socket
684 	 * is not bound.
685 	 */
686 	if (optlen > IFNAMSIZ - 1)
687 		optlen = IFNAMSIZ - 1;
688 	memset(devname, 0, sizeof(devname));
689 
690 	ret = -EFAULT;
691 	if (copy_from_sockptr(devname, optval, optlen))
692 		goto out;
693 
694 	index = 0;
695 	if (devname[0] != '\0') {
696 		struct net_device *dev;
697 
698 		rcu_read_lock();
699 		dev = dev_get_by_name_rcu(net, devname);
700 		if (dev)
701 			index = dev->ifindex;
702 		rcu_read_unlock();
703 		ret = -ENODEV;
704 		if (!dev)
705 			goto out;
706 	}
707 
708 	sockopt_lock_sock(sk);
709 	ret = sock_bindtoindex_locked(sk, index);
710 	sockopt_release_sock(sk);
711 out:
712 #endif
713 
714 	return ret;
715 }
716 
717 static int sock_getbindtodevice(struct sock *sk, sockptr_t optval,
718 				sockptr_t optlen, int len)
719 {
720 	int ret = -ENOPROTOOPT;
721 #ifdef CONFIG_NETDEVICES
722 	int bound_dev_if = READ_ONCE(sk->sk_bound_dev_if);
723 	struct net *net = sock_net(sk);
724 	char devname[IFNAMSIZ];
725 
726 	if (bound_dev_if == 0) {
727 		len = 0;
728 		goto zero;
729 	}
730 
731 	ret = -EINVAL;
732 	if (len < IFNAMSIZ)
733 		goto out;
734 
735 	ret = netdev_get_name(net, devname, bound_dev_if);
736 	if (ret)
737 		goto out;
738 
739 	len = strlen(devname) + 1;
740 
741 	ret = -EFAULT;
742 	if (copy_to_sockptr(optval, devname, len))
743 		goto out;
744 
745 zero:
746 	ret = -EFAULT;
747 	if (copy_to_sockptr(optlen, &len, sizeof(int)))
748 		goto out;
749 
750 	ret = 0;
751 
752 out:
753 #endif
754 
755 	return ret;
756 }
757 
758 bool sk_mc_loop(const struct sock *sk)
759 {
760 	if (dev_recursion_level())
761 		return false;
762 	if (!sk)
763 		return true;
764 	/* IPV6_ADDRFORM can change sk->sk_family under us. */
765 	switch (READ_ONCE(sk->sk_family)) {
766 	case AF_INET:
767 		return inet_test_bit(MC_LOOP, sk);
768 #if IS_ENABLED(CONFIG_IPV6)
769 	case AF_INET6:
770 		return inet6_test_bit(MC6_LOOP, sk);
771 #endif
772 	}
773 	WARN_ON_ONCE(1);
774 	return true;
775 }
776 EXPORT_SYMBOL(sk_mc_loop);
777 
778 void sock_set_reuseaddr(struct sock *sk)
779 {
780 	lock_sock(sk);
781 	sk->sk_reuse = SK_CAN_REUSE;
782 	release_sock(sk);
783 }
784 EXPORT_SYMBOL(sock_set_reuseaddr);
785 
786 void sock_set_reuseport(struct sock *sk)
787 {
788 	lock_sock(sk);
789 	sk->sk_reuseport = true;
790 	release_sock(sk);
791 }
792 EXPORT_SYMBOL(sock_set_reuseport);
793 
794 void sock_no_linger(struct sock *sk)
795 {
796 	lock_sock(sk);
797 	WRITE_ONCE(sk->sk_lingertime, 0);
798 	sock_set_flag(sk, SOCK_LINGER);
799 	release_sock(sk);
800 }
801 EXPORT_SYMBOL(sock_no_linger);
802 
803 void sock_set_priority(struct sock *sk, u32 priority)
804 {
805 	WRITE_ONCE(sk->sk_priority, priority);
806 }
807 EXPORT_SYMBOL(sock_set_priority);
808 
809 void sock_set_sndtimeo(struct sock *sk, s64 secs)
810 {
811 	lock_sock(sk);
812 	if (secs && secs < MAX_SCHEDULE_TIMEOUT / HZ - 1)
813 		WRITE_ONCE(sk->sk_sndtimeo, secs * HZ);
814 	else
815 		WRITE_ONCE(sk->sk_sndtimeo, MAX_SCHEDULE_TIMEOUT);
816 	release_sock(sk);
817 }
818 EXPORT_SYMBOL(sock_set_sndtimeo);
819 
820 static void __sock_set_timestamps(struct sock *sk, bool val, bool new, bool ns)
821 {
822 	if (val)  {
823 		sock_valbool_flag(sk, SOCK_TSTAMP_NEW, new);
824 		sock_valbool_flag(sk, SOCK_RCVTSTAMPNS, ns);
825 		sock_set_flag(sk, SOCK_RCVTSTAMP);
826 		sock_enable_timestamp(sk, SOCK_TIMESTAMP);
827 	} else {
828 		sock_reset_flag(sk, SOCK_RCVTSTAMP);
829 		sock_reset_flag(sk, SOCK_RCVTSTAMPNS);
830 	}
831 }
832 
833 void sock_enable_timestamps(struct sock *sk)
834 {
835 	lock_sock(sk);
836 	__sock_set_timestamps(sk, true, false, true);
837 	release_sock(sk);
838 }
839 EXPORT_SYMBOL(sock_enable_timestamps);
840 
841 void sock_set_timestamp(struct sock *sk, int optname, bool valbool)
842 {
843 	switch (optname) {
844 	case SO_TIMESTAMP_OLD:
845 		__sock_set_timestamps(sk, valbool, false, false);
846 		break;
847 	case SO_TIMESTAMP_NEW:
848 		__sock_set_timestamps(sk, valbool, true, false);
849 		break;
850 	case SO_TIMESTAMPNS_OLD:
851 		__sock_set_timestamps(sk, valbool, false, true);
852 		break;
853 	case SO_TIMESTAMPNS_NEW:
854 		__sock_set_timestamps(sk, valbool, true, true);
855 		break;
856 	}
857 }
858 
859 static int sock_timestamping_bind_phc(struct sock *sk, int phc_index)
860 {
861 	struct net *net = sock_net(sk);
862 	struct net_device *dev = NULL;
863 	bool match = false;
864 	int *vclock_index;
865 	int i, num;
866 
867 	if (sk->sk_bound_dev_if)
868 		dev = dev_get_by_index(net, sk->sk_bound_dev_if);
869 
870 	if (!dev) {
871 		pr_err("%s: sock not bind to device\n", __func__);
872 		return -EOPNOTSUPP;
873 	}
874 
875 	num = ethtool_get_phc_vclocks(dev, &vclock_index);
876 	dev_put(dev);
877 
878 	for (i = 0; i < num; i++) {
879 		if (*(vclock_index + i) == phc_index) {
880 			match = true;
881 			break;
882 		}
883 	}
884 
885 	if (num > 0)
886 		kfree(vclock_index);
887 
888 	if (!match)
889 		return -EINVAL;
890 
891 	WRITE_ONCE(sk->sk_bind_phc, phc_index);
892 
893 	return 0;
894 }
895 
896 int sock_set_timestamping(struct sock *sk, int optname,
897 			  struct so_timestamping timestamping)
898 {
899 	int val = timestamping.flags;
900 	int ret;
901 
902 	if (val & ~SOF_TIMESTAMPING_MASK)
903 		return -EINVAL;
904 
905 	if (val & SOF_TIMESTAMPING_OPT_ID_TCP &&
906 	    !(val & SOF_TIMESTAMPING_OPT_ID))
907 		return -EINVAL;
908 
909 	if (val & SOF_TIMESTAMPING_OPT_ID &&
910 	    !(sk->sk_tsflags & SOF_TIMESTAMPING_OPT_ID)) {
911 		if (sk_is_tcp(sk)) {
912 			if ((1 << sk->sk_state) &
913 			    (TCPF_CLOSE | TCPF_LISTEN))
914 				return -EINVAL;
915 			if (val & SOF_TIMESTAMPING_OPT_ID_TCP)
916 				atomic_set(&sk->sk_tskey, tcp_sk(sk)->write_seq);
917 			else
918 				atomic_set(&sk->sk_tskey, tcp_sk(sk)->snd_una);
919 		} else {
920 			atomic_set(&sk->sk_tskey, 0);
921 		}
922 	}
923 
924 	if (val & SOF_TIMESTAMPING_OPT_STATS &&
925 	    !(val & SOF_TIMESTAMPING_OPT_TSONLY))
926 		return -EINVAL;
927 
928 	if (val & SOF_TIMESTAMPING_BIND_PHC) {
929 		ret = sock_timestamping_bind_phc(sk, timestamping.bind_phc);
930 		if (ret)
931 			return ret;
932 	}
933 
934 	WRITE_ONCE(sk->sk_tsflags, val);
935 	sock_valbool_flag(sk, SOCK_TSTAMP_NEW, optname == SO_TIMESTAMPING_NEW);
936 
937 	if (val & SOF_TIMESTAMPING_RX_SOFTWARE)
938 		sock_enable_timestamp(sk,
939 				      SOCK_TIMESTAMPING_RX_SOFTWARE);
940 	else
941 		sock_disable_timestamp(sk,
942 				       (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE));
943 	return 0;
944 }
945 
946 void sock_set_keepalive(struct sock *sk)
947 {
948 	lock_sock(sk);
949 	if (sk->sk_prot->keepalive)
950 		sk->sk_prot->keepalive(sk, true);
951 	sock_valbool_flag(sk, SOCK_KEEPOPEN, true);
952 	release_sock(sk);
953 }
954 EXPORT_SYMBOL(sock_set_keepalive);
955 
956 static void __sock_set_rcvbuf(struct sock *sk, int val)
957 {
958 	/* Ensure val * 2 fits into an int, to prevent max_t() from treating it
959 	 * as a negative value.
960 	 */
961 	val = min_t(int, val, INT_MAX / 2);
962 	sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
963 
964 	/* We double it on the way in to account for "struct sk_buff" etc.
965 	 * overhead.   Applications assume that the SO_RCVBUF setting they make
966 	 * will allow that much actual data to be received on that socket.
967 	 *
968 	 * Applications are unaware that "struct sk_buff" and other overheads
969 	 * allocate from the receive buffer during socket buffer allocation.
970 	 *
971 	 * And after considering the possible alternatives, returning the value
972 	 * we actually used in getsockopt is the most desirable behavior.
973 	 */
974 	WRITE_ONCE(sk->sk_rcvbuf, max_t(int, val * 2, SOCK_MIN_RCVBUF));
975 }
976 
977 void sock_set_rcvbuf(struct sock *sk, int val)
978 {
979 	lock_sock(sk);
980 	__sock_set_rcvbuf(sk, val);
981 	release_sock(sk);
982 }
983 EXPORT_SYMBOL(sock_set_rcvbuf);
984 
985 static void __sock_set_mark(struct sock *sk, u32 val)
986 {
987 	if (val != sk->sk_mark) {
988 		WRITE_ONCE(sk->sk_mark, val);
989 		sk_dst_reset(sk);
990 	}
991 }
992 
993 void sock_set_mark(struct sock *sk, u32 val)
994 {
995 	lock_sock(sk);
996 	__sock_set_mark(sk, val);
997 	release_sock(sk);
998 }
999 EXPORT_SYMBOL(sock_set_mark);
1000 
1001 static void sock_release_reserved_memory(struct sock *sk, int bytes)
1002 {
1003 	/* Round down bytes to multiple of pages */
1004 	bytes = round_down(bytes, PAGE_SIZE);
1005 
1006 	WARN_ON(bytes > sk->sk_reserved_mem);
1007 	WRITE_ONCE(sk->sk_reserved_mem, sk->sk_reserved_mem - bytes);
1008 	sk_mem_reclaim(sk);
1009 }
1010 
1011 static int sock_reserve_memory(struct sock *sk, int bytes)
1012 {
1013 	long allocated;
1014 	bool charged;
1015 	int pages;
1016 
1017 	if (!mem_cgroup_sockets_enabled || !sk->sk_memcg || !sk_has_account(sk))
1018 		return -EOPNOTSUPP;
1019 
1020 	if (!bytes)
1021 		return 0;
1022 
1023 	pages = sk_mem_pages(bytes);
1024 
1025 	/* pre-charge to memcg */
1026 	charged = mem_cgroup_charge_skmem(sk->sk_memcg, pages,
1027 					  GFP_KERNEL | __GFP_RETRY_MAYFAIL);
1028 	if (!charged)
1029 		return -ENOMEM;
1030 
1031 	/* pre-charge to forward_alloc */
1032 	sk_memory_allocated_add(sk, pages);
1033 	allocated = sk_memory_allocated(sk);
1034 	/* If the system goes into memory pressure with this
1035 	 * precharge, give up and return error.
1036 	 */
1037 	if (allocated > sk_prot_mem_limits(sk, 1)) {
1038 		sk_memory_allocated_sub(sk, pages);
1039 		mem_cgroup_uncharge_skmem(sk->sk_memcg, pages);
1040 		return -ENOMEM;
1041 	}
1042 	sk_forward_alloc_add(sk, pages << PAGE_SHIFT);
1043 
1044 	WRITE_ONCE(sk->sk_reserved_mem,
1045 		   sk->sk_reserved_mem + (pages << PAGE_SHIFT));
1046 
1047 	return 0;
1048 }
1049 
1050 void sockopt_lock_sock(struct sock *sk)
1051 {
1052 	/* When current->bpf_ctx is set, the setsockopt is called from
1053 	 * a bpf prog.  bpf has ensured the sk lock has been
1054 	 * acquired before calling setsockopt().
1055 	 */
1056 	if (has_current_bpf_ctx())
1057 		return;
1058 
1059 	lock_sock(sk);
1060 }
1061 EXPORT_SYMBOL(sockopt_lock_sock);
1062 
1063 void sockopt_release_sock(struct sock *sk)
1064 {
1065 	if (has_current_bpf_ctx())
1066 		return;
1067 
1068 	release_sock(sk);
1069 }
1070 EXPORT_SYMBOL(sockopt_release_sock);
1071 
1072 bool sockopt_ns_capable(struct user_namespace *ns, int cap)
1073 {
1074 	return has_current_bpf_ctx() || ns_capable(ns, cap);
1075 }
1076 EXPORT_SYMBOL(sockopt_ns_capable);
1077 
1078 bool sockopt_capable(int cap)
1079 {
1080 	return has_current_bpf_ctx() || capable(cap);
1081 }
1082 EXPORT_SYMBOL(sockopt_capable);
1083 
1084 /*
1085  *	This is meant for all protocols to use and covers goings on
1086  *	at the socket level. Everything here is generic.
1087  */
1088 
1089 int sk_setsockopt(struct sock *sk, int level, int optname,
1090 		  sockptr_t optval, unsigned int optlen)
1091 {
1092 	struct so_timestamping timestamping;
1093 	struct socket *sock = sk->sk_socket;
1094 	struct sock_txtime sk_txtime;
1095 	int val;
1096 	int valbool;
1097 	struct linger ling;
1098 	int ret = 0;
1099 
1100 	/*
1101 	 *	Options without arguments
1102 	 */
1103 
1104 	if (optname == SO_BINDTODEVICE)
1105 		return sock_setbindtodevice(sk, optval, optlen);
1106 
1107 	if (optlen < sizeof(int))
1108 		return -EINVAL;
1109 
1110 	if (copy_from_sockptr(&val, optval, sizeof(val)))
1111 		return -EFAULT;
1112 
1113 	valbool = val ? 1 : 0;
1114 
1115 	/* handle options which do not require locking the socket. */
1116 	switch (optname) {
1117 	case SO_PRIORITY:
1118 		if ((val >= 0 && val <= 6) ||
1119 		    sockopt_ns_capable(sock_net(sk)->user_ns, CAP_NET_RAW) ||
1120 		    sockopt_ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) {
1121 			sock_set_priority(sk, val);
1122 			return 0;
1123 		}
1124 		return -EPERM;
1125 	case SO_PASSSEC:
1126 		assign_bit(SOCK_PASSSEC, &sock->flags, valbool);
1127 		return 0;
1128 	case SO_PASSCRED:
1129 		assign_bit(SOCK_PASSCRED, &sock->flags, valbool);
1130 		return 0;
1131 	case SO_PASSPIDFD:
1132 		assign_bit(SOCK_PASSPIDFD, &sock->flags, valbool);
1133 		return 0;
1134 	case SO_TYPE:
1135 	case SO_PROTOCOL:
1136 	case SO_DOMAIN:
1137 	case SO_ERROR:
1138 		return -ENOPROTOOPT;
1139 #ifdef CONFIG_NET_RX_BUSY_POLL
1140 	case SO_BUSY_POLL:
1141 		if (val < 0)
1142 			return -EINVAL;
1143 		WRITE_ONCE(sk->sk_ll_usec, val);
1144 		return 0;
1145 	case SO_PREFER_BUSY_POLL:
1146 		if (valbool && !sockopt_capable(CAP_NET_ADMIN))
1147 			return -EPERM;
1148 		WRITE_ONCE(sk->sk_prefer_busy_poll, valbool);
1149 		return 0;
1150 	case SO_BUSY_POLL_BUDGET:
1151 		if (val > READ_ONCE(sk->sk_busy_poll_budget) &&
1152 		    !sockopt_capable(CAP_NET_ADMIN))
1153 			return -EPERM;
1154 		if (val < 0 || val > U16_MAX)
1155 			return -EINVAL;
1156 		WRITE_ONCE(sk->sk_busy_poll_budget, val);
1157 		return 0;
1158 #endif
1159 	case SO_MAX_PACING_RATE:
1160 		{
1161 		unsigned long ulval = (val == ~0U) ? ~0UL : (unsigned int)val;
1162 		unsigned long pacing_rate;
1163 
1164 		if (sizeof(ulval) != sizeof(val) &&
1165 		    optlen >= sizeof(ulval) &&
1166 		    copy_from_sockptr(&ulval, optval, sizeof(ulval))) {
1167 			return -EFAULT;
1168 		}
1169 		if (ulval != ~0UL)
1170 			cmpxchg(&sk->sk_pacing_status,
1171 				SK_PACING_NONE,
1172 				SK_PACING_NEEDED);
1173 		/* Pairs with READ_ONCE() from sk_getsockopt() */
1174 		WRITE_ONCE(sk->sk_max_pacing_rate, ulval);
1175 		pacing_rate = READ_ONCE(sk->sk_pacing_rate);
1176 		if (ulval < pacing_rate)
1177 			WRITE_ONCE(sk->sk_pacing_rate, ulval);
1178 		return 0;
1179 		}
1180 	case SO_TXREHASH:
1181 		if (val < -1 || val > 1)
1182 			return -EINVAL;
1183 		if ((u8)val == SOCK_TXREHASH_DEFAULT)
1184 			val = READ_ONCE(sock_net(sk)->core.sysctl_txrehash);
1185 		/* Paired with READ_ONCE() in tcp_rtx_synack()
1186 		 * and sk_getsockopt().
1187 		 */
1188 		WRITE_ONCE(sk->sk_txrehash, (u8)val);
1189 		return 0;
1190 	}
1191 
1192 	sockopt_lock_sock(sk);
1193 
1194 	switch (optname) {
1195 	case SO_DEBUG:
1196 		if (val && !sockopt_capable(CAP_NET_ADMIN))
1197 			ret = -EACCES;
1198 		else
1199 			sock_valbool_flag(sk, SOCK_DBG, valbool);
1200 		break;
1201 	case SO_REUSEADDR:
1202 		sk->sk_reuse = (valbool ? SK_CAN_REUSE : SK_NO_REUSE);
1203 		break;
1204 	case SO_REUSEPORT:
1205 		sk->sk_reuseport = valbool;
1206 		break;
1207 	case SO_DONTROUTE:
1208 		sock_valbool_flag(sk, SOCK_LOCALROUTE, valbool);
1209 		sk_dst_reset(sk);
1210 		break;
1211 	case SO_BROADCAST:
1212 		sock_valbool_flag(sk, SOCK_BROADCAST, valbool);
1213 		break;
1214 	case SO_SNDBUF:
1215 		/* Don't error on this BSD doesn't and if you think
1216 		 * about it this is right. Otherwise apps have to
1217 		 * play 'guess the biggest size' games. RCVBUF/SNDBUF
1218 		 * are treated in BSD as hints
1219 		 */
1220 		val = min_t(u32, val, READ_ONCE(sysctl_wmem_max));
1221 set_sndbuf:
1222 		/* Ensure val * 2 fits into an int, to prevent max_t()
1223 		 * from treating it as a negative value.
1224 		 */
1225 		val = min_t(int, val, INT_MAX / 2);
1226 		sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
1227 		WRITE_ONCE(sk->sk_sndbuf,
1228 			   max_t(int, val * 2, SOCK_MIN_SNDBUF));
1229 		/* Wake up sending tasks if we upped the value. */
1230 		sk->sk_write_space(sk);
1231 		break;
1232 
1233 	case SO_SNDBUFFORCE:
1234 		if (!sockopt_capable(CAP_NET_ADMIN)) {
1235 			ret = -EPERM;
1236 			break;
1237 		}
1238 
1239 		/* No negative values (to prevent underflow, as val will be
1240 		 * multiplied by 2).
1241 		 */
1242 		if (val < 0)
1243 			val = 0;
1244 		goto set_sndbuf;
1245 
1246 	case SO_RCVBUF:
1247 		/* Don't error on this BSD doesn't and if you think
1248 		 * about it this is right. Otherwise apps have to
1249 		 * play 'guess the biggest size' games. RCVBUF/SNDBUF
1250 		 * are treated in BSD as hints
1251 		 */
1252 		__sock_set_rcvbuf(sk, min_t(u32, val, READ_ONCE(sysctl_rmem_max)));
1253 		break;
1254 
1255 	case SO_RCVBUFFORCE:
1256 		if (!sockopt_capable(CAP_NET_ADMIN)) {
1257 			ret = -EPERM;
1258 			break;
1259 		}
1260 
1261 		/* No negative values (to prevent underflow, as val will be
1262 		 * multiplied by 2).
1263 		 */
1264 		__sock_set_rcvbuf(sk, max(val, 0));
1265 		break;
1266 
1267 	case SO_KEEPALIVE:
1268 		if (sk->sk_prot->keepalive)
1269 			sk->sk_prot->keepalive(sk, valbool);
1270 		sock_valbool_flag(sk, SOCK_KEEPOPEN, valbool);
1271 		break;
1272 
1273 	case SO_OOBINLINE:
1274 		sock_valbool_flag(sk, SOCK_URGINLINE, valbool);
1275 		break;
1276 
1277 	case SO_NO_CHECK:
1278 		sk->sk_no_check_tx = valbool;
1279 		break;
1280 
1281 	case SO_LINGER:
1282 		if (optlen < sizeof(ling)) {
1283 			ret = -EINVAL;	/* 1003.1g */
1284 			break;
1285 		}
1286 		if (copy_from_sockptr(&ling, optval, sizeof(ling))) {
1287 			ret = -EFAULT;
1288 			break;
1289 		}
1290 		if (!ling.l_onoff) {
1291 			sock_reset_flag(sk, SOCK_LINGER);
1292 		} else {
1293 			unsigned long t_sec = ling.l_linger;
1294 
1295 			if (t_sec >= MAX_SCHEDULE_TIMEOUT / HZ)
1296 				WRITE_ONCE(sk->sk_lingertime, MAX_SCHEDULE_TIMEOUT);
1297 			else
1298 				WRITE_ONCE(sk->sk_lingertime, t_sec * HZ);
1299 			sock_set_flag(sk, SOCK_LINGER);
1300 		}
1301 		break;
1302 
1303 	case SO_BSDCOMPAT:
1304 		break;
1305 
1306 	case SO_TIMESTAMP_OLD:
1307 	case SO_TIMESTAMP_NEW:
1308 	case SO_TIMESTAMPNS_OLD:
1309 	case SO_TIMESTAMPNS_NEW:
1310 		sock_set_timestamp(sk, optname, valbool);
1311 		break;
1312 
1313 	case SO_TIMESTAMPING_NEW:
1314 	case SO_TIMESTAMPING_OLD:
1315 		if (optlen == sizeof(timestamping)) {
1316 			if (copy_from_sockptr(&timestamping, optval,
1317 					      sizeof(timestamping))) {
1318 				ret = -EFAULT;
1319 				break;
1320 			}
1321 		} else {
1322 			memset(&timestamping, 0, sizeof(timestamping));
1323 			timestamping.flags = val;
1324 		}
1325 		ret = sock_set_timestamping(sk, optname, timestamping);
1326 		break;
1327 
1328 	case SO_RCVLOWAT:
1329 		{
1330 		int (*set_rcvlowat)(struct sock *sk, int val) = NULL;
1331 
1332 		if (val < 0)
1333 			val = INT_MAX;
1334 		if (sock)
1335 			set_rcvlowat = READ_ONCE(sock->ops)->set_rcvlowat;
1336 		if (set_rcvlowat)
1337 			ret = set_rcvlowat(sk, val);
1338 		else
1339 			WRITE_ONCE(sk->sk_rcvlowat, val ? : 1);
1340 		break;
1341 		}
1342 	case SO_RCVTIMEO_OLD:
1343 	case SO_RCVTIMEO_NEW:
1344 		ret = sock_set_timeout(&sk->sk_rcvtimeo, optval,
1345 				       optlen, optname == SO_RCVTIMEO_OLD);
1346 		break;
1347 
1348 	case SO_SNDTIMEO_OLD:
1349 	case SO_SNDTIMEO_NEW:
1350 		ret = sock_set_timeout(&sk->sk_sndtimeo, optval,
1351 				       optlen, optname == SO_SNDTIMEO_OLD);
1352 		break;
1353 
1354 	case SO_ATTACH_FILTER: {
1355 		struct sock_fprog fprog;
1356 
1357 		ret = copy_bpf_fprog_from_user(&fprog, optval, optlen);
1358 		if (!ret)
1359 			ret = sk_attach_filter(&fprog, sk);
1360 		break;
1361 	}
1362 	case SO_ATTACH_BPF:
1363 		ret = -EINVAL;
1364 		if (optlen == sizeof(u32)) {
1365 			u32 ufd;
1366 
1367 			ret = -EFAULT;
1368 			if (copy_from_sockptr(&ufd, optval, sizeof(ufd)))
1369 				break;
1370 
1371 			ret = sk_attach_bpf(ufd, sk);
1372 		}
1373 		break;
1374 
1375 	case SO_ATTACH_REUSEPORT_CBPF: {
1376 		struct sock_fprog fprog;
1377 
1378 		ret = copy_bpf_fprog_from_user(&fprog, optval, optlen);
1379 		if (!ret)
1380 			ret = sk_reuseport_attach_filter(&fprog, sk);
1381 		break;
1382 	}
1383 	case SO_ATTACH_REUSEPORT_EBPF:
1384 		ret = -EINVAL;
1385 		if (optlen == sizeof(u32)) {
1386 			u32 ufd;
1387 
1388 			ret = -EFAULT;
1389 			if (copy_from_sockptr(&ufd, optval, sizeof(ufd)))
1390 				break;
1391 
1392 			ret = sk_reuseport_attach_bpf(ufd, sk);
1393 		}
1394 		break;
1395 
1396 	case SO_DETACH_REUSEPORT_BPF:
1397 		ret = reuseport_detach_prog(sk);
1398 		break;
1399 
1400 	case SO_DETACH_FILTER:
1401 		ret = sk_detach_filter(sk);
1402 		break;
1403 
1404 	case SO_LOCK_FILTER:
1405 		if (sock_flag(sk, SOCK_FILTER_LOCKED) && !valbool)
1406 			ret = -EPERM;
1407 		else
1408 			sock_valbool_flag(sk, SOCK_FILTER_LOCKED, valbool);
1409 		break;
1410 
1411 	case SO_MARK:
1412 		if (!sockopt_ns_capable(sock_net(sk)->user_ns, CAP_NET_RAW) &&
1413 		    !sockopt_ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) {
1414 			ret = -EPERM;
1415 			break;
1416 		}
1417 
1418 		__sock_set_mark(sk, val);
1419 		break;
1420 	case SO_RCVMARK:
1421 		sock_valbool_flag(sk, SOCK_RCVMARK, valbool);
1422 		break;
1423 
1424 	case SO_RXQ_OVFL:
1425 		sock_valbool_flag(sk, SOCK_RXQ_OVFL, valbool);
1426 		break;
1427 
1428 	case SO_WIFI_STATUS:
1429 		sock_valbool_flag(sk, SOCK_WIFI_STATUS, valbool);
1430 		break;
1431 
1432 	case SO_PEEK_OFF:
1433 		{
1434 		int (*set_peek_off)(struct sock *sk, int val);
1435 
1436 		set_peek_off = READ_ONCE(sock->ops)->set_peek_off;
1437 		if (set_peek_off)
1438 			ret = set_peek_off(sk, val);
1439 		else
1440 			ret = -EOPNOTSUPP;
1441 		break;
1442 		}
1443 
1444 	case SO_NOFCS:
1445 		sock_valbool_flag(sk, SOCK_NOFCS, valbool);
1446 		break;
1447 
1448 	case SO_SELECT_ERR_QUEUE:
1449 		sock_valbool_flag(sk, SOCK_SELECT_ERR_QUEUE, valbool);
1450 		break;
1451 
1452 
1453 	case SO_INCOMING_CPU:
1454 		reuseport_update_incoming_cpu(sk, val);
1455 		break;
1456 
1457 	case SO_CNX_ADVICE:
1458 		if (val == 1)
1459 			dst_negative_advice(sk);
1460 		break;
1461 
1462 	case SO_ZEROCOPY:
1463 		if (sk->sk_family == PF_INET || sk->sk_family == PF_INET6) {
1464 			if (!(sk_is_tcp(sk) ||
1465 			      (sk->sk_type == SOCK_DGRAM &&
1466 			       sk->sk_protocol == IPPROTO_UDP)))
1467 				ret = -EOPNOTSUPP;
1468 		} else if (sk->sk_family != PF_RDS) {
1469 			ret = -EOPNOTSUPP;
1470 		}
1471 		if (!ret) {
1472 			if (val < 0 || val > 1)
1473 				ret = -EINVAL;
1474 			else
1475 				sock_valbool_flag(sk, SOCK_ZEROCOPY, valbool);
1476 		}
1477 		break;
1478 
1479 	case SO_TXTIME:
1480 		if (optlen != sizeof(struct sock_txtime)) {
1481 			ret = -EINVAL;
1482 			break;
1483 		} else if (copy_from_sockptr(&sk_txtime, optval,
1484 			   sizeof(struct sock_txtime))) {
1485 			ret = -EFAULT;
1486 			break;
1487 		} else if (sk_txtime.flags & ~SOF_TXTIME_FLAGS_MASK) {
1488 			ret = -EINVAL;
1489 			break;
1490 		}
1491 		/* CLOCK_MONOTONIC is only used by sch_fq, and this packet
1492 		 * scheduler has enough safe guards.
1493 		 */
1494 		if (sk_txtime.clockid != CLOCK_MONOTONIC &&
1495 		    !sockopt_ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) {
1496 			ret = -EPERM;
1497 			break;
1498 		}
1499 		sock_valbool_flag(sk, SOCK_TXTIME, true);
1500 		sk->sk_clockid = sk_txtime.clockid;
1501 		sk->sk_txtime_deadline_mode =
1502 			!!(sk_txtime.flags & SOF_TXTIME_DEADLINE_MODE);
1503 		sk->sk_txtime_report_errors =
1504 			!!(sk_txtime.flags & SOF_TXTIME_REPORT_ERRORS);
1505 		break;
1506 
1507 	case SO_BINDTOIFINDEX:
1508 		ret = sock_bindtoindex_locked(sk, val);
1509 		break;
1510 
1511 	case SO_BUF_LOCK:
1512 		if (val & ~SOCK_BUF_LOCK_MASK) {
1513 			ret = -EINVAL;
1514 			break;
1515 		}
1516 		sk->sk_userlocks = val | (sk->sk_userlocks &
1517 					  ~SOCK_BUF_LOCK_MASK);
1518 		break;
1519 
1520 	case SO_RESERVE_MEM:
1521 	{
1522 		int delta;
1523 
1524 		if (val < 0) {
1525 			ret = -EINVAL;
1526 			break;
1527 		}
1528 
1529 		delta = val - sk->sk_reserved_mem;
1530 		if (delta < 0)
1531 			sock_release_reserved_memory(sk, -delta);
1532 		else
1533 			ret = sock_reserve_memory(sk, delta);
1534 		break;
1535 	}
1536 
1537 	default:
1538 		ret = -ENOPROTOOPT;
1539 		break;
1540 	}
1541 	sockopt_release_sock(sk);
1542 	return ret;
1543 }
1544 
1545 int sock_setsockopt(struct socket *sock, int level, int optname,
1546 		    sockptr_t optval, unsigned int optlen)
1547 {
1548 	return sk_setsockopt(sock->sk, level, optname,
1549 			     optval, optlen);
1550 }
1551 EXPORT_SYMBOL(sock_setsockopt);
1552 
1553 static const struct cred *sk_get_peer_cred(struct sock *sk)
1554 {
1555 	const struct cred *cred;
1556 
1557 	spin_lock(&sk->sk_peer_lock);
1558 	cred = get_cred(sk->sk_peer_cred);
1559 	spin_unlock(&sk->sk_peer_lock);
1560 
1561 	return cred;
1562 }
1563 
1564 static void cred_to_ucred(struct pid *pid, const struct cred *cred,
1565 			  struct ucred *ucred)
1566 {
1567 	ucred->pid = pid_vnr(pid);
1568 	ucred->uid = ucred->gid = -1;
1569 	if (cred) {
1570 		struct user_namespace *current_ns = current_user_ns();
1571 
1572 		ucred->uid = from_kuid_munged(current_ns, cred->euid);
1573 		ucred->gid = from_kgid_munged(current_ns, cred->egid);
1574 	}
1575 }
1576 
1577 static int groups_to_user(sockptr_t dst, const struct group_info *src)
1578 {
1579 	struct user_namespace *user_ns = current_user_ns();
1580 	int i;
1581 
1582 	for (i = 0; i < src->ngroups; i++) {
1583 		gid_t gid = from_kgid_munged(user_ns, src->gid[i]);
1584 
1585 		if (copy_to_sockptr_offset(dst, i * sizeof(gid), &gid, sizeof(gid)))
1586 			return -EFAULT;
1587 	}
1588 
1589 	return 0;
1590 }
1591 
1592 int sk_getsockopt(struct sock *sk, int level, int optname,
1593 		  sockptr_t optval, sockptr_t optlen)
1594 {
1595 	struct socket *sock = sk->sk_socket;
1596 
1597 	union {
1598 		int val;
1599 		u64 val64;
1600 		unsigned long ulval;
1601 		struct linger ling;
1602 		struct old_timeval32 tm32;
1603 		struct __kernel_old_timeval tm;
1604 		struct  __kernel_sock_timeval stm;
1605 		struct sock_txtime txtime;
1606 		struct so_timestamping timestamping;
1607 	} v;
1608 
1609 	int lv = sizeof(int);
1610 	int len;
1611 
1612 	if (copy_from_sockptr(&len, optlen, sizeof(int)))
1613 		return -EFAULT;
1614 	if (len < 0)
1615 		return -EINVAL;
1616 
1617 	memset(&v, 0, sizeof(v));
1618 
1619 	switch (optname) {
1620 	case SO_DEBUG:
1621 		v.val = sock_flag(sk, SOCK_DBG);
1622 		break;
1623 
1624 	case SO_DONTROUTE:
1625 		v.val = sock_flag(sk, SOCK_LOCALROUTE);
1626 		break;
1627 
1628 	case SO_BROADCAST:
1629 		v.val = sock_flag(sk, SOCK_BROADCAST);
1630 		break;
1631 
1632 	case SO_SNDBUF:
1633 		v.val = READ_ONCE(sk->sk_sndbuf);
1634 		break;
1635 
1636 	case SO_RCVBUF:
1637 		v.val = READ_ONCE(sk->sk_rcvbuf);
1638 		break;
1639 
1640 	case SO_REUSEADDR:
1641 		v.val = sk->sk_reuse;
1642 		break;
1643 
1644 	case SO_REUSEPORT:
1645 		v.val = sk->sk_reuseport;
1646 		break;
1647 
1648 	case SO_KEEPALIVE:
1649 		v.val = sock_flag(sk, SOCK_KEEPOPEN);
1650 		break;
1651 
1652 	case SO_TYPE:
1653 		v.val = sk->sk_type;
1654 		break;
1655 
1656 	case SO_PROTOCOL:
1657 		v.val = sk->sk_protocol;
1658 		break;
1659 
1660 	case SO_DOMAIN:
1661 		v.val = sk->sk_family;
1662 		break;
1663 
1664 	case SO_ERROR:
1665 		v.val = -sock_error(sk);
1666 		if (v.val == 0)
1667 			v.val = xchg(&sk->sk_err_soft, 0);
1668 		break;
1669 
1670 	case SO_OOBINLINE:
1671 		v.val = sock_flag(sk, SOCK_URGINLINE);
1672 		break;
1673 
1674 	case SO_NO_CHECK:
1675 		v.val = sk->sk_no_check_tx;
1676 		break;
1677 
1678 	case SO_PRIORITY:
1679 		v.val = READ_ONCE(sk->sk_priority);
1680 		break;
1681 
1682 	case SO_LINGER:
1683 		lv		= sizeof(v.ling);
1684 		v.ling.l_onoff	= sock_flag(sk, SOCK_LINGER);
1685 		v.ling.l_linger	= READ_ONCE(sk->sk_lingertime) / HZ;
1686 		break;
1687 
1688 	case SO_BSDCOMPAT:
1689 		break;
1690 
1691 	case SO_TIMESTAMP_OLD:
1692 		v.val = sock_flag(sk, SOCK_RCVTSTAMP) &&
1693 				!sock_flag(sk, SOCK_TSTAMP_NEW) &&
1694 				!sock_flag(sk, SOCK_RCVTSTAMPNS);
1695 		break;
1696 
1697 	case SO_TIMESTAMPNS_OLD:
1698 		v.val = sock_flag(sk, SOCK_RCVTSTAMPNS) && !sock_flag(sk, SOCK_TSTAMP_NEW);
1699 		break;
1700 
1701 	case SO_TIMESTAMP_NEW:
1702 		v.val = sock_flag(sk, SOCK_RCVTSTAMP) && sock_flag(sk, SOCK_TSTAMP_NEW);
1703 		break;
1704 
1705 	case SO_TIMESTAMPNS_NEW:
1706 		v.val = sock_flag(sk, SOCK_RCVTSTAMPNS) && sock_flag(sk, SOCK_TSTAMP_NEW);
1707 		break;
1708 
1709 	case SO_TIMESTAMPING_OLD:
1710 	case SO_TIMESTAMPING_NEW:
1711 		lv = sizeof(v.timestamping);
1712 		/* For the later-added case SO_TIMESTAMPING_NEW: Be strict about only
1713 		 * returning the flags when they were set through the same option.
1714 		 * Don't change the beviour for the old case SO_TIMESTAMPING_OLD.
1715 		 */
1716 		if (optname == SO_TIMESTAMPING_OLD || sock_flag(sk, SOCK_TSTAMP_NEW)) {
1717 			v.timestamping.flags = READ_ONCE(sk->sk_tsflags);
1718 			v.timestamping.bind_phc = READ_ONCE(sk->sk_bind_phc);
1719 		}
1720 		break;
1721 
1722 	case SO_RCVTIMEO_OLD:
1723 	case SO_RCVTIMEO_NEW:
1724 		lv = sock_get_timeout(READ_ONCE(sk->sk_rcvtimeo), &v,
1725 				      SO_RCVTIMEO_OLD == optname);
1726 		break;
1727 
1728 	case SO_SNDTIMEO_OLD:
1729 	case SO_SNDTIMEO_NEW:
1730 		lv = sock_get_timeout(READ_ONCE(sk->sk_sndtimeo), &v,
1731 				      SO_SNDTIMEO_OLD == optname);
1732 		break;
1733 
1734 	case SO_RCVLOWAT:
1735 		v.val = READ_ONCE(sk->sk_rcvlowat);
1736 		break;
1737 
1738 	case SO_SNDLOWAT:
1739 		v.val = 1;
1740 		break;
1741 
1742 	case SO_PASSCRED:
1743 		v.val = !!test_bit(SOCK_PASSCRED, &sock->flags);
1744 		break;
1745 
1746 	case SO_PASSPIDFD:
1747 		v.val = !!test_bit(SOCK_PASSPIDFD, &sock->flags);
1748 		break;
1749 
1750 	case SO_PEERCRED:
1751 	{
1752 		struct ucred peercred;
1753 		if (len > sizeof(peercred))
1754 			len = sizeof(peercred);
1755 
1756 		spin_lock(&sk->sk_peer_lock);
1757 		cred_to_ucred(sk->sk_peer_pid, sk->sk_peer_cred, &peercred);
1758 		spin_unlock(&sk->sk_peer_lock);
1759 
1760 		if (copy_to_sockptr(optval, &peercred, len))
1761 			return -EFAULT;
1762 		goto lenout;
1763 	}
1764 
1765 	case SO_PEERPIDFD:
1766 	{
1767 		struct pid *peer_pid;
1768 		struct file *pidfd_file = NULL;
1769 		int pidfd;
1770 
1771 		if (len > sizeof(pidfd))
1772 			len = sizeof(pidfd);
1773 
1774 		spin_lock(&sk->sk_peer_lock);
1775 		peer_pid = get_pid(sk->sk_peer_pid);
1776 		spin_unlock(&sk->sk_peer_lock);
1777 
1778 		if (!peer_pid)
1779 			return -ENODATA;
1780 
1781 		pidfd = pidfd_prepare(peer_pid, 0, &pidfd_file);
1782 		put_pid(peer_pid);
1783 		if (pidfd < 0)
1784 			return pidfd;
1785 
1786 		if (copy_to_sockptr(optval, &pidfd, len) ||
1787 		    copy_to_sockptr(optlen, &len, sizeof(int))) {
1788 			put_unused_fd(pidfd);
1789 			fput(pidfd_file);
1790 
1791 			return -EFAULT;
1792 		}
1793 
1794 		fd_install(pidfd, pidfd_file);
1795 		return 0;
1796 	}
1797 
1798 	case SO_PEERGROUPS:
1799 	{
1800 		const struct cred *cred;
1801 		int ret, n;
1802 
1803 		cred = sk_get_peer_cred(sk);
1804 		if (!cred)
1805 			return -ENODATA;
1806 
1807 		n = cred->group_info->ngroups;
1808 		if (len < n * sizeof(gid_t)) {
1809 			len = n * sizeof(gid_t);
1810 			put_cred(cred);
1811 			return copy_to_sockptr(optlen, &len, sizeof(int)) ? -EFAULT : -ERANGE;
1812 		}
1813 		len = n * sizeof(gid_t);
1814 
1815 		ret = groups_to_user(optval, cred->group_info);
1816 		put_cred(cred);
1817 		if (ret)
1818 			return ret;
1819 		goto lenout;
1820 	}
1821 
1822 	case SO_PEERNAME:
1823 	{
1824 		struct sockaddr_storage address;
1825 
1826 		lv = READ_ONCE(sock->ops)->getname(sock, (struct sockaddr *)&address, 2);
1827 		if (lv < 0)
1828 			return -ENOTCONN;
1829 		if (lv < len)
1830 			return -EINVAL;
1831 		if (copy_to_sockptr(optval, &address, len))
1832 			return -EFAULT;
1833 		goto lenout;
1834 	}
1835 
1836 	/* Dubious BSD thing... Probably nobody even uses it, but
1837 	 * the UNIX standard wants it for whatever reason... -DaveM
1838 	 */
1839 	case SO_ACCEPTCONN:
1840 		v.val = sk->sk_state == TCP_LISTEN;
1841 		break;
1842 
1843 	case SO_PASSSEC:
1844 		v.val = !!test_bit(SOCK_PASSSEC, &sock->flags);
1845 		break;
1846 
1847 	case SO_PEERSEC:
1848 		return security_socket_getpeersec_stream(sock,
1849 							 optval, optlen, len);
1850 
1851 	case SO_MARK:
1852 		v.val = READ_ONCE(sk->sk_mark);
1853 		break;
1854 
1855 	case SO_RCVMARK:
1856 		v.val = sock_flag(sk, SOCK_RCVMARK);
1857 		break;
1858 
1859 	case SO_RXQ_OVFL:
1860 		v.val = sock_flag(sk, SOCK_RXQ_OVFL);
1861 		break;
1862 
1863 	case SO_WIFI_STATUS:
1864 		v.val = sock_flag(sk, SOCK_WIFI_STATUS);
1865 		break;
1866 
1867 	case SO_PEEK_OFF:
1868 		if (!READ_ONCE(sock->ops)->set_peek_off)
1869 			return -EOPNOTSUPP;
1870 
1871 		v.val = READ_ONCE(sk->sk_peek_off);
1872 		break;
1873 	case SO_NOFCS:
1874 		v.val = sock_flag(sk, SOCK_NOFCS);
1875 		break;
1876 
1877 	case SO_BINDTODEVICE:
1878 		return sock_getbindtodevice(sk, optval, optlen, len);
1879 
1880 	case SO_GET_FILTER:
1881 		len = sk_get_filter(sk, optval, len);
1882 		if (len < 0)
1883 			return len;
1884 
1885 		goto lenout;
1886 
1887 	case SO_LOCK_FILTER:
1888 		v.val = sock_flag(sk, SOCK_FILTER_LOCKED);
1889 		break;
1890 
1891 	case SO_BPF_EXTENSIONS:
1892 		v.val = bpf_tell_extensions();
1893 		break;
1894 
1895 	case SO_SELECT_ERR_QUEUE:
1896 		v.val = sock_flag(sk, SOCK_SELECT_ERR_QUEUE);
1897 		break;
1898 
1899 #ifdef CONFIG_NET_RX_BUSY_POLL
1900 	case SO_BUSY_POLL:
1901 		v.val = READ_ONCE(sk->sk_ll_usec);
1902 		break;
1903 	case SO_PREFER_BUSY_POLL:
1904 		v.val = READ_ONCE(sk->sk_prefer_busy_poll);
1905 		break;
1906 #endif
1907 
1908 	case SO_MAX_PACING_RATE:
1909 		/* The READ_ONCE() pair with the WRITE_ONCE() in sk_setsockopt() */
1910 		if (sizeof(v.ulval) != sizeof(v.val) && len >= sizeof(v.ulval)) {
1911 			lv = sizeof(v.ulval);
1912 			v.ulval = READ_ONCE(sk->sk_max_pacing_rate);
1913 		} else {
1914 			/* 32bit version */
1915 			v.val = min_t(unsigned long, ~0U,
1916 				      READ_ONCE(sk->sk_max_pacing_rate));
1917 		}
1918 		break;
1919 
1920 	case SO_INCOMING_CPU:
1921 		v.val = READ_ONCE(sk->sk_incoming_cpu);
1922 		break;
1923 
1924 	case SO_MEMINFO:
1925 	{
1926 		u32 meminfo[SK_MEMINFO_VARS];
1927 
1928 		sk_get_meminfo(sk, meminfo);
1929 
1930 		len = min_t(unsigned int, len, sizeof(meminfo));
1931 		if (copy_to_sockptr(optval, &meminfo, len))
1932 			return -EFAULT;
1933 
1934 		goto lenout;
1935 	}
1936 
1937 #ifdef CONFIG_NET_RX_BUSY_POLL
1938 	case SO_INCOMING_NAPI_ID:
1939 		v.val = READ_ONCE(sk->sk_napi_id);
1940 
1941 		/* aggregate non-NAPI IDs down to 0 */
1942 		if (v.val < MIN_NAPI_ID)
1943 			v.val = 0;
1944 
1945 		break;
1946 #endif
1947 
1948 	case SO_COOKIE:
1949 		lv = sizeof(u64);
1950 		if (len < lv)
1951 			return -EINVAL;
1952 		v.val64 = sock_gen_cookie(sk);
1953 		break;
1954 
1955 	case SO_ZEROCOPY:
1956 		v.val = sock_flag(sk, SOCK_ZEROCOPY);
1957 		break;
1958 
1959 	case SO_TXTIME:
1960 		lv = sizeof(v.txtime);
1961 		v.txtime.clockid = sk->sk_clockid;
1962 		v.txtime.flags |= sk->sk_txtime_deadline_mode ?
1963 				  SOF_TXTIME_DEADLINE_MODE : 0;
1964 		v.txtime.flags |= sk->sk_txtime_report_errors ?
1965 				  SOF_TXTIME_REPORT_ERRORS : 0;
1966 		break;
1967 
1968 	case SO_BINDTOIFINDEX:
1969 		v.val = READ_ONCE(sk->sk_bound_dev_if);
1970 		break;
1971 
1972 	case SO_NETNS_COOKIE:
1973 		lv = sizeof(u64);
1974 		if (len != lv)
1975 			return -EINVAL;
1976 		v.val64 = sock_net(sk)->net_cookie;
1977 		break;
1978 
1979 	case SO_BUF_LOCK:
1980 		v.val = sk->sk_userlocks & SOCK_BUF_LOCK_MASK;
1981 		break;
1982 
1983 	case SO_RESERVE_MEM:
1984 		v.val = READ_ONCE(sk->sk_reserved_mem);
1985 		break;
1986 
1987 	case SO_TXREHASH:
1988 		/* Paired with WRITE_ONCE() in sk_setsockopt() */
1989 		v.val = READ_ONCE(sk->sk_txrehash);
1990 		break;
1991 
1992 	default:
1993 		/* We implement the SO_SNDLOWAT etc to not be settable
1994 		 * (1003.1g 7).
1995 		 */
1996 		return -ENOPROTOOPT;
1997 	}
1998 
1999 	if (len > lv)
2000 		len = lv;
2001 	if (copy_to_sockptr(optval, &v, len))
2002 		return -EFAULT;
2003 lenout:
2004 	if (copy_to_sockptr(optlen, &len, sizeof(int)))
2005 		return -EFAULT;
2006 	return 0;
2007 }
2008 
2009 /*
2010  * Initialize an sk_lock.
2011  *
2012  * (We also register the sk_lock with the lock validator.)
2013  */
2014 static inline void sock_lock_init(struct sock *sk)
2015 {
2016 	if (sk->sk_kern_sock)
2017 		sock_lock_init_class_and_name(
2018 			sk,
2019 			af_family_kern_slock_key_strings[sk->sk_family],
2020 			af_family_kern_slock_keys + sk->sk_family,
2021 			af_family_kern_key_strings[sk->sk_family],
2022 			af_family_kern_keys + sk->sk_family);
2023 	else
2024 		sock_lock_init_class_and_name(
2025 			sk,
2026 			af_family_slock_key_strings[sk->sk_family],
2027 			af_family_slock_keys + sk->sk_family,
2028 			af_family_key_strings[sk->sk_family],
2029 			af_family_keys + sk->sk_family);
2030 }
2031 
2032 /*
2033  * Copy all fields from osk to nsk but nsk->sk_refcnt must not change yet,
2034  * even temporarly, because of RCU lookups. sk_node should also be left as is.
2035  * We must not copy fields between sk_dontcopy_begin and sk_dontcopy_end
2036  */
2037 static void sock_copy(struct sock *nsk, const struct sock *osk)
2038 {
2039 	const struct proto *prot = READ_ONCE(osk->sk_prot);
2040 #ifdef CONFIG_SECURITY_NETWORK
2041 	void *sptr = nsk->sk_security;
2042 #endif
2043 
2044 	/* If we move sk_tx_queue_mapping out of the private section,
2045 	 * we must check if sk_tx_queue_clear() is called after
2046 	 * sock_copy() in sk_clone_lock().
2047 	 */
2048 	BUILD_BUG_ON(offsetof(struct sock, sk_tx_queue_mapping) <
2049 		     offsetof(struct sock, sk_dontcopy_begin) ||
2050 		     offsetof(struct sock, sk_tx_queue_mapping) >=
2051 		     offsetof(struct sock, sk_dontcopy_end));
2052 
2053 	memcpy(nsk, osk, offsetof(struct sock, sk_dontcopy_begin));
2054 
2055 	memcpy(&nsk->sk_dontcopy_end, &osk->sk_dontcopy_end,
2056 	       prot->obj_size - offsetof(struct sock, sk_dontcopy_end));
2057 
2058 #ifdef CONFIG_SECURITY_NETWORK
2059 	nsk->sk_security = sptr;
2060 	security_sk_clone(osk, nsk);
2061 #endif
2062 }
2063 
2064 static struct sock *sk_prot_alloc(struct proto *prot, gfp_t priority,
2065 		int family)
2066 {
2067 	struct sock *sk;
2068 	struct kmem_cache *slab;
2069 
2070 	slab = prot->slab;
2071 	if (slab != NULL) {
2072 		sk = kmem_cache_alloc(slab, priority & ~__GFP_ZERO);
2073 		if (!sk)
2074 			return sk;
2075 		if (want_init_on_alloc(priority))
2076 			sk_prot_clear_nulls(sk, prot->obj_size);
2077 	} else
2078 		sk = kmalloc(prot->obj_size, priority);
2079 
2080 	if (sk != NULL) {
2081 		if (security_sk_alloc(sk, family, priority))
2082 			goto out_free;
2083 
2084 		if (!try_module_get(prot->owner))
2085 			goto out_free_sec;
2086 	}
2087 
2088 	return sk;
2089 
2090 out_free_sec:
2091 	security_sk_free(sk);
2092 out_free:
2093 	if (slab != NULL)
2094 		kmem_cache_free(slab, sk);
2095 	else
2096 		kfree(sk);
2097 	return NULL;
2098 }
2099 
2100 static void sk_prot_free(struct proto *prot, struct sock *sk)
2101 {
2102 	struct kmem_cache *slab;
2103 	struct module *owner;
2104 
2105 	owner = prot->owner;
2106 	slab = prot->slab;
2107 
2108 	cgroup_sk_free(&sk->sk_cgrp_data);
2109 	mem_cgroup_sk_free(sk);
2110 	security_sk_free(sk);
2111 	if (slab != NULL)
2112 		kmem_cache_free(slab, sk);
2113 	else
2114 		kfree(sk);
2115 	module_put(owner);
2116 }
2117 
2118 /**
2119  *	sk_alloc - All socket objects are allocated here
2120  *	@net: the applicable net namespace
2121  *	@family: protocol family
2122  *	@priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
2123  *	@prot: struct proto associated with this new sock instance
2124  *	@kern: is this to be a kernel socket?
2125  */
2126 struct sock *sk_alloc(struct net *net, int family, gfp_t priority,
2127 		      struct proto *prot, int kern)
2128 {
2129 	struct sock *sk;
2130 
2131 	sk = sk_prot_alloc(prot, priority | __GFP_ZERO, family);
2132 	if (sk) {
2133 		sk->sk_family = family;
2134 		/*
2135 		 * See comment in struct sock definition to understand
2136 		 * why we need sk_prot_creator -acme
2137 		 */
2138 		sk->sk_prot = sk->sk_prot_creator = prot;
2139 		sk->sk_kern_sock = kern;
2140 		sock_lock_init(sk);
2141 		sk->sk_net_refcnt = kern ? 0 : 1;
2142 		if (likely(sk->sk_net_refcnt)) {
2143 			get_net_track(net, &sk->ns_tracker, priority);
2144 			sock_inuse_add(net, 1);
2145 		} else {
2146 			__netns_tracker_alloc(net, &sk->ns_tracker,
2147 					      false, priority);
2148 		}
2149 
2150 		sock_net_set(sk, net);
2151 		refcount_set(&sk->sk_wmem_alloc, 1);
2152 
2153 		mem_cgroup_sk_alloc(sk);
2154 		cgroup_sk_alloc(&sk->sk_cgrp_data);
2155 		sock_update_classid(&sk->sk_cgrp_data);
2156 		sock_update_netprioidx(&sk->sk_cgrp_data);
2157 		sk_tx_queue_clear(sk);
2158 	}
2159 
2160 	return sk;
2161 }
2162 EXPORT_SYMBOL(sk_alloc);
2163 
2164 /* Sockets having SOCK_RCU_FREE will call this function after one RCU
2165  * grace period. This is the case for UDP sockets and TCP listeners.
2166  */
2167 static void __sk_destruct(struct rcu_head *head)
2168 {
2169 	struct sock *sk = container_of(head, struct sock, sk_rcu);
2170 	struct sk_filter *filter;
2171 
2172 	if (sk->sk_destruct)
2173 		sk->sk_destruct(sk);
2174 
2175 	filter = rcu_dereference_check(sk->sk_filter,
2176 				       refcount_read(&sk->sk_wmem_alloc) == 0);
2177 	if (filter) {
2178 		sk_filter_uncharge(sk, filter);
2179 		RCU_INIT_POINTER(sk->sk_filter, NULL);
2180 	}
2181 
2182 	sock_disable_timestamp(sk, SK_FLAGS_TIMESTAMP);
2183 
2184 #ifdef CONFIG_BPF_SYSCALL
2185 	bpf_sk_storage_free(sk);
2186 #endif
2187 
2188 	if (atomic_read(&sk->sk_omem_alloc))
2189 		pr_debug("%s: optmem leakage (%d bytes) detected\n",
2190 			 __func__, atomic_read(&sk->sk_omem_alloc));
2191 
2192 	if (sk->sk_frag.page) {
2193 		put_page(sk->sk_frag.page);
2194 		sk->sk_frag.page = NULL;
2195 	}
2196 
2197 	/* We do not need to acquire sk->sk_peer_lock, we are the last user. */
2198 	put_cred(sk->sk_peer_cred);
2199 	put_pid(sk->sk_peer_pid);
2200 
2201 	if (likely(sk->sk_net_refcnt))
2202 		put_net_track(sock_net(sk), &sk->ns_tracker);
2203 	else
2204 		__netns_tracker_free(sock_net(sk), &sk->ns_tracker, false);
2205 
2206 	sk_prot_free(sk->sk_prot_creator, sk);
2207 }
2208 
2209 void sk_destruct(struct sock *sk)
2210 {
2211 	bool use_call_rcu = sock_flag(sk, SOCK_RCU_FREE);
2212 
2213 	if (rcu_access_pointer(sk->sk_reuseport_cb)) {
2214 		reuseport_detach_sock(sk);
2215 		use_call_rcu = true;
2216 	}
2217 
2218 	if (use_call_rcu)
2219 		call_rcu(&sk->sk_rcu, __sk_destruct);
2220 	else
2221 		__sk_destruct(&sk->sk_rcu);
2222 }
2223 
2224 static void __sk_free(struct sock *sk)
2225 {
2226 	if (likely(sk->sk_net_refcnt))
2227 		sock_inuse_add(sock_net(sk), -1);
2228 
2229 	if (unlikely(sk->sk_net_refcnt && sock_diag_has_destroy_listeners(sk)))
2230 		sock_diag_broadcast_destroy(sk);
2231 	else
2232 		sk_destruct(sk);
2233 }
2234 
2235 void sk_free(struct sock *sk)
2236 {
2237 	/*
2238 	 * We subtract one from sk_wmem_alloc and can know if
2239 	 * some packets are still in some tx queue.
2240 	 * If not null, sock_wfree() will call __sk_free(sk) later
2241 	 */
2242 	if (refcount_dec_and_test(&sk->sk_wmem_alloc))
2243 		__sk_free(sk);
2244 }
2245 EXPORT_SYMBOL(sk_free);
2246 
2247 static void sk_init_common(struct sock *sk)
2248 {
2249 	skb_queue_head_init(&sk->sk_receive_queue);
2250 	skb_queue_head_init(&sk->sk_write_queue);
2251 	skb_queue_head_init(&sk->sk_error_queue);
2252 
2253 	rwlock_init(&sk->sk_callback_lock);
2254 	lockdep_set_class_and_name(&sk->sk_receive_queue.lock,
2255 			af_rlock_keys + sk->sk_family,
2256 			af_family_rlock_key_strings[sk->sk_family]);
2257 	lockdep_set_class_and_name(&sk->sk_write_queue.lock,
2258 			af_wlock_keys + sk->sk_family,
2259 			af_family_wlock_key_strings[sk->sk_family]);
2260 	lockdep_set_class_and_name(&sk->sk_error_queue.lock,
2261 			af_elock_keys + sk->sk_family,
2262 			af_family_elock_key_strings[sk->sk_family]);
2263 	lockdep_set_class_and_name(&sk->sk_callback_lock,
2264 			af_callback_keys + sk->sk_family,
2265 			af_family_clock_key_strings[sk->sk_family]);
2266 }
2267 
2268 /**
2269  *	sk_clone_lock - clone a socket, and lock its clone
2270  *	@sk: the socket to clone
2271  *	@priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
2272  *
2273  *	Caller must unlock socket even in error path (bh_unlock_sock(newsk))
2274  */
2275 struct sock *sk_clone_lock(const struct sock *sk, const gfp_t priority)
2276 {
2277 	struct proto *prot = READ_ONCE(sk->sk_prot);
2278 	struct sk_filter *filter;
2279 	bool is_charged = true;
2280 	struct sock *newsk;
2281 
2282 	newsk = sk_prot_alloc(prot, priority, sk->sk_family);
2283 	if (!newsk)
2284 		goto out;
2285 
2286 	sock_copy(newsk, sk);
2287 
2288 	newsk->sk_prot_creator = prot;
2289 
2290 	/* SANITY */
2291 	if (likely(newsk->sk_net_refcnt)) {
2292 		get_net_track(sock_net(newsk), &newsk->ns_tracker, priority);
2293 		sock_inuse_add(sock_net(newsk), 1);
2294 	} else {
2295 		/* Kernel sockets are not elevating the struct net refcount.
2296 		 * Instead, use a tracker to more easily detect if a layer
2297 		 * is not properly dismantling its kernel sockets at netns
2298 		 * destroy time.
2299 		 */
2300 		__netns_tracker_alloc(sock_net(newsk), &newsk->ns_tracker,
2301 				      false, priority);
2302 	}
2303 	sk_node_init(&newsk->sk_node);
2304 	sock_lock_init(newsk);
2305 	bh_lock_sock(newsk);
2306 	newsk->sk_backlog.head	= newsk->sk_backlog.tail = NULL;
2307 	newsk->sk_backlog.len = 0;
2308 
2309 	atomic_set(&newsk->sk_rmem_alloc, 0);
2310 
2311 	/* sk_wmem_alloc set to one (see sk_free() and sock_wfree()) */
2312 	refcount_set(&newsk->sk_wmem_alloc, 1);
2313 
2314 	atomic_set(&newsk->sk_omem_alloc, 0);
2315 	sk_init_common(newsk);
2316 
2317 	newsk->sk_dst_cache	= NULL;
2318 	newsk->sk_dst_pending_confirm = 0;
2319 	newsk->sk_wmem_queued	= 0;
2320 	newsk->sk_forward_alloc = 0;
2321 	newsk->sk_reserved_mem  = 0;
2322 	atomic_set(&newsk->sk_drops, 0);
2323 	newsk->sk_send_head	= NULL;
2324 	newsk->sk_userlocks	= sk->sk_userlocks & ~SOCK_BINDPORT_LOCK;
2325 	atomic_set(&newsk->sk_zckey, 0);
2326 
2327 	sock_reset_flag(newsk, SOCK_DONE);
2328 
2329 	/* sk->sk_memcg will be populated at accept() time */
2330 	newsk->sk_memcg = NULL;
2331 
2332 	cgroup_sk_clone(&newsk->sk_cgrp_data);
2333 
2334 	rcu_read_lock();
2335 	filter = rcu_dereference(sk->sk_filter);
2336 	if (filter != NULL)
2337 		/* though it's an empty new sock, the charging may fail
2338 		 * if sysctl_optmem_max was changed between creation of
2339 		 * original socket and cloning
2340 		 */
2341 		is_charged = sk_filter_charge(newsk, filter);
2342 	RCU_INIT_POINTER(newsk->sk_filter, filter);
2343 	rcu_read_unlock();
2344 
2345 	if (unlikely(!is_charged || xfrm_sk_clone_policy(newsk, sk))) {
2346 		/* We need to make sure that we don't uncharge the new
2347 		 * socket if we couldn't charge it in the first place
2348 		 * as otherwise we uncharge the parent's filter.
2349 		 */
2350 		if (!is_charged)
2351 			RCU_INIT_POINTER(newsk->sk_filter, NULL);
2352 		sk_free_unlock_clone(newsk);
2353 		newsk = NULL;
2354 		goto out;
2355 	}
2356 	RCU_INIT_POINTER(newsk->sk_reuseport_cb, NULL);
2357 
2358 	if (bpf_sk_storage_clone(sk, newsk)) {
2359 		sk_free_unlock_clone(newsk);
2360 		newsk = NULL;
2361 		goto out;
2362 	}
2363 
2364 	/* Clear sk_user_data if parent had the pointer tagged
2365 	 * as not suitable for copying when cloning.
2366 	 */
2367 	if (sk_user_data_is_nocopy(newsk))
2368 		newsk->sk_user_data = NULL;
2369 
2370 	newsk->sk_err	   = 0;
2371 	newsk->sk_err_soft = 0;
2372 	newsk->sk_priority = 0;
2373 	newsk->sk_incoming_cpu = raw_smp_processor_id();
2374 
2375 	/* Before updating sk_refcnt, we must commit prior changes to memory
2376 	 * (Documentation/RCU/rculist_nulls.rst for details)
2377 	 */
2378 	smp_wmb();
2379 	refcount_set(&newsk->sk_refcnt, 2);
2380 
2381 	sk_set_socket(newsk, NULL);
2382 	sk_tx_queue_clear(newsk);
2383 	RCU_INIT_POINTER(newsk->sk_wq, NULL);
2384 
2385 	if (newsk->sk_prot->sockets_allocated)
2386 		sk_sockets_allocated_inc(newsk);
2387 
2388 	if (sock_needs_netstamp(sk) && newsk->sk_flags & SK_FLAGS_TIMESTAMP)
2389 		net_enable_timestamp();
2390 out:
2391 	return newsk;
2392 }
2393 EXPORT_SYMBOL_GPL(sk_clone_lock);
2394 
2395 void sk_free_unlock_clone(struct sock *sk)
2396 {
2397 	/* It is still raw copy of parent, so invalidate
2398 	 * destructor and make plain sk_free() */
2399 	sk->sk_destruct = NULL;
2400 	bh_unlock_sock(sk);
2401 	sk_free(sk);
2402 }
2403 EXPORT_SYMBOL_GPL(sk_free_unlock_clone);
2404 
2405 static u32 sk_dst_gso_max_size(struct sock *sk, struct dst_entry *dst)
2406 {
2407 	bool is_ipv6 = false;
2408 	u32 max_size;
2409 
2410 #if IS_ENABLED(CONFIG_IPV6)
2411 	is_ipv6 = (sk->sk_family == AF_INET6 &&
2412 		   !ipv6_addr_v4mapped(&sk->sk_v6_rcv_saddr));
2413 #endif
2414 	/* pairs with the WRITE_ONCE() in netif_set_gso(_ipv4)_max_size() */
2415 	max_size = is_ipv6 ? READ_ONCE(dst->dev->gso_max_size) :
2416 			READ_ONCE(dst->dev->gso_ipv4_max_size);
2417 	if (max_size > GSO_LEGACY_MAX_SIZE && !sk_is_tcp(sk))
2418 		max_size = GSO_LEGACY_MAX_SIZE;
2419 
2420 	return max_size - (MAX_TCP_HEADER + 1);
2421 }
2422 
2423 void sk_setup_caps(struct sock *sk, struct dst_entry *dst)
2424 {
2425 	u32 max_segs = 1;
2426 
2427 	sk->sk_route_caps = dst->dev->features;
2428 	if (sk_is_tcp(sk))
2429 		sk->sk_route_caps |= NETIF_F_GSO;
2430 	if (sk->sk_route_caps & NETIF_F_GSO)
2431 		sk->sk_route_caps |= NETIF_F_GSO_SOFTWARE;
2432 	if (unlikely(sk->sk_gso_disabled))
2433 		sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
2434 	if (sk_can_gso(sk)) {
2435 		if (dst->header_len && !xfrm_dst_offload_ok(dst)) {
2436 			sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
2437 		} else {
2438 			sk->sk_route_caps |= NETIF_F_SG | NETIF_F_HW_CSUM;
2439 			sk->sk_gso_max_size = sk_dst_gso_max_size(sk, dst);
2440 			/* pairs with the WRITE_ONCE() in netif_set_gso_max_segs() */
2441 			max_segs = max_t(u32, READ_ONCE(dst->dev->gso_max_segs), 1);
2442 		}
2443 	}
2444 	sk->sk_gso_max_segs = max_segs;
2445 	sk_dst_set(sk, dst);
2446 }
2447 EXPORT_SYMBOL_GPL(sk_setup_caps);
2448 
2449 /*
2450  *	Simple resource managers for sockets.
2451  */
2452 
2453 
2454 /*
2455  * Write buffer destructor automatically called from kfree_skb.
2456  */
2457 void sock_wfree(struct sk_buff *skb)
2458 {
2459 	struct sock *sk = skb->sk;
2460 	unsigned int len = skb->truesize;
2461 	bool free;
2462 
2463 	if (!sock_flag(sk, SOCK_USE_WRITE_QUEUE)) {
2464 		if (sock_flag(sk, SOCK_RCU_FREE) &&
2465 		    sk->sk_write_space == sock_def_write_space) {
2466 			rcu_read_lock();
2467 			free = refcount_sub_and_test(len, &sk->sk_wmem_alloc);
2468 			sock_def_write_space_wfree(sk);
2469 			rcu_read_unlock();
2470 			if (unlikely(free))
2471 				__sk_free(sk);
2472 			return;
2473 		}
2474 
2475 		/*
2476 		 * Keep a reference on sk_wmem_alloc, this will be released
2477 		 * after sk_write_space() call
2478 		 */
2479 		WARN_ON(refcount_sub_and_test(len - 1, &sk->sk_wmem_alloc));
2480 		sk->sk_write_space(sk);
2481 		len = 1;
2482 	}
2483 	/*
2484 	 * if sk_wmem_alloc reaches 0, we must finish what sk_free()
2485 	 * could not do because of in-flight packets
2486 	 */
2487 	if (refcount_sub_and_test(len, &sk->sk_wmem_alloc))
2488 		__sk_free(sk);
2489 }
2490 EXPORT_SYMBOL(sock_wfree);
2491 
2492 /* This variant of sock_wfree() is used by TCP,
2493  * since it sets SOCK_USE_WRITE_QUEUE.
2494  */
2495 void __sock_wfree(struct sk_buff *skb)
2496 {
2497 	struct sock *sk = skb->sk;
2498 
2499 	if (refcount_sub_and_test(skb->truesize, &sk->sk_wmem_alloc))
2500 		__sk_free(sk);
2501 }
2502 
2503 void skb_set_owner_w(struct sk_buff *skb, struct sock *sk)
2504 {
2505 	skb_orphan(skb);
2506 	skb->sk = sk;
2507 #ifdef CONFIG_INET
2508 	if (unlikely(!sk_fullsock(sk))) {
2509 		skb->destructor = sock_edemux;
2510 		sock_hold(sk);
2511 		return;
2512 	}
2513 #endif
2514 	skb->destructor = sock_wfree;
2515 	skb_set_hash_from_sk(skb, sk);
2516 	/*
2517 	 * We used to take a refcount on sk, but following operation
2518 	 * is enough to guarantee sk_free() wont free this sock until
2519 	 * all in-flight packets are completed
2520 	 */
2521 	refcount_add(skb->truesize, &sk->sk_wmem_alloc);
2522 }
2523 EXPORT_SYMBOL(skb_set_owner_w);
2524 
2525 static bool can_skb_orphan_partial(const struct sk_buff *skb)
2526 {
2527 #ifdef CONFIG_TLS_DEVICE
2528 	/* Drivers depend on in-order delivery for crypto offload,
2529 	 * partial orphan breaks out-of-order-OK logic.
2530 	 */
2531 	if (skb->decrypted)
2532 		return false;
2533 #endif
2534 	return (skb->destructor == sock_wfree ||
2535 		(IS_ENABLED(CONFIG_INET) && skb->destructor == tcp_wfree));
2536 }
2537 
2538 /* This helper is used by netem, as it can hold packets in its
2539  * delay queue. We want to allow the owner socket to send more
2540  * packets, as if they were already TX completed by a typical driver.
2541  * But we also want to keep skb->sk set because some packet schedulers
2542  * rely on it (sch_fq for example).
2543  */
2544 void skb_orphan_partial(struct sk_buff *skb)
2545 {
2546 	if (skb_is_tcp_pure_ack(skb))
2547 		return;
2548 
2549 	if (can_skb_orphan_partial(skb) && skb_set_owner_sk_safe(skb, skb->sk))
2550 		return;
2551 
2552 	skb_orphan(skb);
2553 }
2554 EXPORT_SYMBOL(skb_orphan_partial);
2555 
2556 /*
2557  * Read buffer destructor automatically called from kfree_skb.
2558  */
2559 void sock_rfree(struct sk_buff *skb)
2560 {
2561 	struct sock *sk = skb->sk;
2562 	unsigned int len = skb->truesize;
2563 
2564 	atomic_sub(len, &sk->sk_rmem_alloc);
2565 	sk_mem_uncharge(sk, len);
2566 }
2567 EXPORT_SYMBOL(sock_rfree);
2568 
2569 /*
2570  * Buffer destructor for skbs that are not used directly in read or write
2571  * path, e.g. for error handler skbs. Automatically called from kfree_skb.
2572  */
2573 void sock_efree(struct sk_buff *skb)
2574 {
2575 	sock_put(skb->sk);
2576 }
2577 EXPORT_SYMBOL(sock_efree);
2578 
2579 /* Buffer destructor for prefetch/receive path where reference count may
2580  * not be held, e.g. for listen sockets.
2581  */
2582 #ifdef CONFIG_INET
2583 void sock_pfree(struct sk_buff *skb)
2584 {
2585 	if (sk_is_refcounted(skb->sk))
2586 		sock_gen_put(skb->sk);
2587 }
2588 EXPORT_SYMBOL(sock_pfree);
2589 #endif /* CONFIG_INET */
2590 
2591 kuid_t sock_i_uid(struct sock *sk)
2592 {
2593 	kuid_t uid;
2594 
2595 	read_lock_bh(&sk->sk_callback_lock);
2596 	uid = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_uid : GLOBAL_ROOT_UID;
2597 	read_unlock_bh(&sk->sk_callback_lock);
2598 	return uid;
2599 }
2600 EXPORT_SYMBOL(sock_i_uid);
2601 
2602 unsigned long __sock_i_ino(struct sock *sk)
2603 {
2604 	unsigned long ino;
2605 
2606 	read_lock(&sk->sk_callback_lock);
2607 	ino = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_ino : 0;
2608 	read_unlock(&sk->sk_callback_lock);
2609 	return ino;
2610 }
2611 EXPORT_SYMBOL(__sock_i_ino);
2612 
2613 unsigned long sock_i_ino(struct sock *sk)
2614 {
2615 	unsigned long ino;
2616 
2617 	local_bh_disable();
2618 	ino = __sock_i_ino(sk);
2619 	local_bh_enable();
2620 	return ino;
2621 }
2622 EXPORT_SYMBOL(sock_i_ino);
2623 
2624 /*
2625  * Allocate a skb from the socket's send buffer.
2626  */
2627 struct sk_buff *sock_wmalloc(struct sock *sk, unsigned long size, int force,
2628 			     gfp_t priority)
2629 {
2630 	if (force ||
2631 	    refcount_read(&sk->sk_wmem_alloc) < READ_ONCE(sk->sk_sndbuf)) {
2632 		struct sk_buff *skb = alloc_skb(size, priority);
2633 
2634 		if (skb) {
2635 			skb_set_owner_w(skb, sk);
2636 			return skb;
2637 		}
2638 	}
2639 	return NULL;
2640 }
2641 EXPORT_SYMBOL(sock_wmalloc);
2642 
2643 static void sock_ofree(struct sk_buff *skb)
2644 {
2645 	struct sock *sk = skb->sk;
2646 
2647 	atomic_sub(skb->truesize, &sk->sk_omem_alloc);
2648 }
2649 
2650 struct sk_buff *sock_omalloc(struct sock *sk, unsigned long size,
2651 			     gfp_t priority)
2652 {
2653 	struct sk_buff *skb;
2654 
2655 	/* small safe race: SKB_TRUESIZE may differ from final skb->truesize */
2656 	if (atomic_read(&sk->sk_omem_alloc) + SKB_TRUESIZE(size) >
2657 	    READ_ONCE(sock_net(sk)->core.sysctl_optmem_max))
2658 		return NULL;
2659 
2660 	skb = alloc_skb(size, priority);
2661 	if (!skb)
2662 		return NULL;
2663 
2664 	atomic_add(skb->truesize, &sk->sk_omem_alloc);
2665 	skb->sk = sk;
2666 	skb->destructor = sock_ofree;
2667 	return skb;
2668 }
2669 
2670 /*
2671  * Allocate a memory block from the socket's option memory buffer.
2672  */
2673 void *sock_kmalloc(struct sock *sk, int size, gfp_t priority)
2674 {
2675 	int optmem_max = READ_ONCE(sock_net(sk)->core.sysctl_optmem_max);
2676 
2677 	if ((unsigned int)size <= optmem_max &&
2678 	    atomic_read(&sk->sk_omem_alloc) + size < optmem_max) {
2679 		void *mem;
2680 		/* First do the add, to avoid the race if kmalloc
2681 		 * might sleep.
2682 		 */
2683 		atomic_add(size, &sk->sk_omem_alloc);
2684 		mem = kmalloc(size, priority);
2685 		if (mem)
2686 			return mem;
2687 		atomic_sub(size, &sk->sk_omem_alloc);
2688 	}
2689 	return NULL;
2690 }
2691 EXPORT_SYMBOL(sock_kmalloc);
2692 
2693 /* Free an option memory block. Note, we actually want the inline
2694  * here as this allows gcc to detect the nullify and fold away the
2695  * condition entirely.
2696  */
2697 static inline void __sock_kfree_s(struct sock *sk, void *mem, int size,
2698 				  const bool nullify)
2699 {
2700 	if (WARN_ON_ONCE(!mem))
2701 		return;
2702 	if (nullify)
2703 		kfree_sensitive(mem);
2704 	else
2705 		kfree(mem);
2706 	atomic_sub(size, &sk->sk_omem_alloc);
2707 }
2708 
2709 void sock_kfree_s(struct sock *sk, void *mem, int size)
2710 {
2711 	__sock_kfree_s(sk, mem, size, false);
2712 }
2713 EXPORT_SYMBOL(sock_kfree_s);
2714 
2715 void sock_kzfree_s(struct sock *sk, void *mem, int size)
2716 {
2717 	__sock_kfree_s(sk, mem, size, true);
2718 }
2719 EXPORT_SYMBOL(sock_kzfree_s);
2720 
2721 /* It is almost wait_for_tcp_memory minus release_sock/lock_sock.
2722    I think, these locks should be removed for datagram sockets.
2723  */
2724 static long sock_wait_for_wmem(struct sock *sk, long timeo)
2725 {
2726 	DEFINE_WAIT(wait);
2727 
2728 	sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
2729 	for (;;) {
2730 		if (!timeo)
2731 			break;
2732 		if (signal_pending(current))
2733 			break;
2734 		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
2735 		prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
2736 		if (refcount_read(&sk->sk_wmem_alloc) < READ_ONCE(sk->sk_sndbuf))
2737 			break;
2738 		if (READ_ONCE(sk->sk_shutdown) & SEND_SHUTDOWN)
2739 			break;
2740 		if (READ_ONCE(sk->sk_err))
2741 			break;
2742 		timeo = schedule_timeout(timeo);
2743 	}
2744 	finish_wait(sk_sleep(sk), &wait);
2745 	return timeo;
2746 }
2747 
2748 
2749 /*
2750  *	Generic send/receive buffer handlers
2751  */
2752 
2753 struct sk_buff *sock_alloc_send_pskb(struct sock *sk, unsigned long header_len,
2754 				     unsigned long data_len, int noblock,
2755 				     int *errcode, int max_page_order)
2756 {
2757 	struct sk_buff *skb;
2758 	long timeo;
2759 	int err;
2760 
2761 	timeo = sock_sndtimeo(sk, noblock);
2762 	for (;;) {
2763 		err = sock_error(sk);
2764 		if (err != 0)
2765 			goto failure;
2766 
2767 		err = -EPIPE;
2768 		if (READ_ONCE(sk->sk_shutdown) & SEND_SHUTDOWN)
2769 			goto failure;
2770 
2771 		if (sk_wmem_alloc_get(sk) < READ_ONCE(sk->sk_sndbuf))
2772 			break;
2773 
2774 		sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
2775 		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
2776 		err = -EAGAIN;
2777 		if (!timeo)
2778 			goto failure;
2779 		if (signal_pending(current))
2780 			goto interrupted;
2781 		timeo = sock_wait_for_wmem(sk, timeo);
2782 	}
2783 	skb = alloc_skb_with_frags(header_len, data_len, max_page_order,
2784 				   errcode, sk->sk_allocation);
2785 	if (skb)
2786 		skb_set_owner_w(skb, sk);
2787 	return skb;
2788 
2789 interrupted:
2790 	err = sock_intr_errno(timeo);
2791 failure:
2792 	*errcode = err;
2793 	return NULL;
2794 }
2795 EXPORT_SYMBOL(sock_alloc_send_pskb);
2796 
2797 int __sock_cmsg_send(struct sock *sk, struct cmsghdr *cmsg,
2798 		     struct sockcm_cookie *sockc)
2799 {
2800 	u32 tsflags;
2801 
2802 	switch (cmsg->cmsg_type) {
2803 	case SO_MARK:
2804 		if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_RAW) &&
2805 		    !ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
2806 			return -EPERM;
2807 		if (cmsg->cmsg_len != CMSG_LEN(sizeof(u32)))
2808 			return -EINVAL;
2809 		sockc->mark = *(u32 *)CMSG_DATA(cmsg);
2810 		break;
2811 	case SO_TIMESTAMPING_OLD:
2812 	case SO_TIMESTAMPING_NEW:
2813 		if (cmsg->cmsg_len != CMSG_LEN(sizeof(u32)))
2814 			return -EINVAL;
2815 
2816 		tsflags = *(u32 *)CMSG_DATA(cmsg);
2817 		if (tsflags & ~SOF_TIMESTAMPING_TX_RECORD_MASK)
2818 			return -EINVAL;
2819 
2820 		sockc->tsflags &= ~SOF_TIMESTAMPING_TX_RECORD_MASK;
2821 		sockc->tsflags |= tsflags;
2822 		break;
2823 	case SCM_TXTIME:
2824 		if (!sock_flag(sk, SOCK_TXTIME))
2825 			return -EINVAL;
2826 		if (cmsg->cmsg_len != CMSG_LEN(sizeof(u64)))
2827 			return -EINVAL;
2828 		sockc->transmit_time = get_unaligned((u64 *)CMSG_DATA(cmsg));
2829 		break;
2830 	/* SCM_RIGHTS and SCM_CREDENTIALS are semantically in SOL_UNIX. */
2831 	case SCM_RIGHTS:
2832 	case SCM_CREDENTIALS:
2833 		break;
2834 	default:
2835 		return -EINVAL;
2836 	}
2837 	return 0;
2838 }
2839 EXPORT_SYMBOL(__sock_cmsg_send);
2840 
2841 int sock_cmsg_send(struct sock *sk, struct msghdr *msg,
2842 		   struct sockcm_cookie *sockc)
2843 {
2844 	struct cmsghdr *cmsg;
2845 	int ret;
2846 
2847 	for_each_cmsghdr(cmsg, msg) {
2848 		if (!CMSG_OK(msg, cmsg))
2849 			return -EINVAL;
2850 		if (cmsg->cmsg_level != SOL_SOCKET)
2851 			continue;
2852 		ret = __sock_cmsg_send(sk, cmsg, sockc);
2853 		if (ret)
2854 			return ret;
2855 	}
2856 	return 0;
2857 }
2858 EXPORT_SYMBOL(sock_cmsg_send);
2859 
2860 static void sk_enter_memory_pressure(struct sock *sk)
2861 {
2862 	if (!sk->sk_prot->enter_memory_pressure)
2863 		return;
2864 
2865 	sk->sk_prot->enter_memory_pressure(sk);
2866 }
2867 
2868 static void sk_leave_memory_pressure(struct sock *sk)
2869 {
2870 	if (sk->sk_prot->leave_memory_pressure) {
2871 		INDIRECT_CALL_INET_1(sk->sk_prot->leave_memory_pressure,
2872 				     tcp_leave_memory_pressure, sk);
2873 	} else {
2874 		unsigned long *memory_pressure = sk->sk_prot->memory_pressure;
2875 
2876 		if (memory_pressure && READ_ONCE(*memory_pressure))
2877 			WRITE_ONCE(*memory_pressure, 0);
2878 	}
2879 }
2880 
2881 DEFINE_STATIC_KEY_FALSE(net_high_order_alloc_disable_key);
2882 
2883 /**
2884  * skb_page_frag_refill - check that a page_frag contains enough room
2885  * @sz: minimum size of the fragment we want to get
2886  * @pfrag: pointer to page_frag
2887  * @gfp: priority for memory allocation
2888  *
2889  * Note: While this allocator tries to use high order pages, there is
2890  * no guarantee that allocations succeed. Therefore, @sz MUST be
2891  * less or equal than PAGE_SIZE.
2892  */
2893 bool skb_page_frag_refill(unsigned int sz, struct page_frag *pfrag, gfp_t gfp)
2894 {
2895 	if (pfrag->page) {
2896 		if (page_ref_count(pfrag->page) == 1) {
2897 			pfrag->offset = 0;
2898 			return true;
2899 		}
2900 		if (pfrag->offset + sz <= pfrag->size)
2901 			return true;
2902 		put_page(pfrag->page);
2903 	}
2904 
2905 	pfrag->offset = 0;
2906 	if (SKB_FRAG_PAGE_ORDER &&
2907 	    !static_branch_unlikely(&net_high_order_alloc_disable_key)) {
2908 		/* Avoid direct reclaim but allow kswapd to wake */
2909 		pfrag->page = alloc_pages((gfp & ~__GFP_DIRECT_RECLAIM) |
2910 					  __GFP_COMP | __GFP_NOWARN |
2911 					  __GFP_NORETRY,
2912 					  SKB_FRAG_PAGE_ORDER);
2913 		if (likely(pfrag->page)) {
2914 			pfrag->size = PAGE_SIZE << SKB_FRAG_PAGE_ORDER;
2915 			return true;
2916 		}
2917 	}
2918 	pfrag->page = alloc_page(gfp);
2919 	if (likely(pfrag->page)) {
2920 		pfrag->size = PAGE_SIZE;
2921 		return true;
2922 	}
2923 	return false;
2924 }
2925 EXPORT_SYMBOL(skb_page_frag_refill);
2926 
2927 bool sk_page_frag_refill(struct sock *sk, struct page_frag *pfrag)
2928 {
2929 	if (likely(skb_page_frag_refill(32U, pfrag, sk->sk_allocation)))
2930 		return true;
2931 
2932 	sk_enter_memory_pressure(sk);
2933 	sk_stream_moderate_sndbuf(sk);
2934 	return false;
2935 }
2936 EXPORT_SYMBOL(sk_page_frag_refill);
2937 
2938 void __lock_sock(struct sock *sk)
2939 	__releases(&sk->sk_lock.slock)
2940 	__acquires(&sk->sk_lock.slock)
2941 {
2942 	DEFINE_WAIT(wait);
2943 
2944 	for (;;) {
2945 		prepare_to_wait_exclusive(&sk->sk_lock.wq, &wait,
2946 					TASK_UNINTERRUPTIBLE);
2947 		spin_unlock_bh(&sk->sk_lock.slock);
2948 		schedule();
2949 		spin_lock_bh(&sk->sk_lock.slock);
2950 		if (!sock_owned_by_user(sk))
2951 			break;
2952 	}
2953 	finish_wait(&sk->sk_lock.wq, &wait);
2954 }
2955 
2956 void __release_sock(struct sock *sk)
2957 	__releases(&sk->sk_lock.slock)
2958 	__acquires(&sk->sk_lock.slock)
2959 {
2960 	struct sk_buff *skb, *next;
2961 
2962 	while ((skb = sk->sk_backlog.head) != NULL) {
2963 		sk->sk_backlog.head = sk->sk_backlog.tail = NULL;
2964 
2965 		spin_unlock_bh(&sk->sk_lock.slock);
2966 
2967 		do {
2968 			next = skb->next;
2969 			prefetch(next);
2970 			DEBUG_NET_WARN_ON_ONCE(skb_dst_is_noref(skb));
2971 			skb_mark_not_on_list(skb);
2972 			sk_backlog_rcv(sk, skb);
2973 
2974 			cond_resched();
2975 
2976 			skb = next;
2977 		} while (skb != NULL);
2978 
2979 		spin_lock_bh(&sk->sk_lock.slock);
2980 	}
2981 
2982 	/*
2983 	 * Doing the zeroing here guarantee we can not loop forever
2984 	 * while a wild producer attempts to flood us.
2985 	 */
2986 	sk->sk_backlog.len = 0;
2987 }
2988 
2989 void __sk_flush_backlog(struct sock *sk)
2990 {
2991 	spin_lock_bh(&sk->sk_lock.slock);
2992 	__release_sock(sk);
2993 
2994 	if (sk->sk_prot->release_cb)
2995 		INDIRECT_CALL_INET_1(sk->sk_prot->release_cb,
2996 				     tcp_release_cb, sk);
2997 
2998 	spin_unlock_bh(&sk->sk_lock.slock);
2999 }
3000 EXPORT_SYMBOL_GPL(__sk_flush_backlog);
3001 
3002 /**
3003  * sk_wait_data - wait for data to arrive at sk_receive_queue
3004  * @sk:    sock to wait on
3005  * @timeo: for how long
3006  * @skb:   last skb seen on sk_receive_queue
3007  *
3008  * Now socket state including sk->sk_err is changed only under lock,
3009  * hence we may omit checks after joining wait queue.
3010  * We check receive queue before schedule() only as optimization;
3011  * it is very likely that release_sock() added new data.
3012  */
3013 int sk_wait_data(struct sock *sk, long *timeo, const struct sk_buff *skb)
3014 {
3015 	DEFINE_WAIT_FUNC(wait, woken_wake_function);
3016 	int rc;
3017 
3018 	add_wait_queue(sk_sleep(sk), &wait);
3019 	sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
3020 	rc = sk_wait_event(sk, timeo, skb_peek_tail(&sk->sk_receive_queue) != skb, &wait);
3021 	sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
3022 	remove_wait_queue(sk_sleep(sk), &wait);
3023 	return rc;
3024 }
3025 EXPORT_SYMBOL(sk_wait_data);
3026 
3027 /**
3028  *	__sk_mem_raise_allocated - increase memory_allocated
3029  *	@sk: socket
3030  *	@size: memory size to allocate
3031  *	@amt: pages to allocate
3032  *	@kind: allocation type
3033  *
3034  *	Similar to __sk_mem_schedule(), but does not update sk_forward_alloc.
3035  *
3036  *	Unlike the globally shared limits among the sockets under same protocol,
3037  *	consuming the budget of a memcg won't have direct effect on other ones.
3038  *	So be optimistic about memcg's tolerance, and leave the callers to decide
3039  *	whether or not to raise allocated through sk_under_memory_pressure() or
3040  *	its variants.
3041  */
3042 int __sk_mem_raise_allocated(struct sock *sk, int size, int amt, int kind)
3043 {
3044 	struct mem_cgroup *memcg = mem_cgroup_sockets_enabled ? sk->sk_memcg : NULL;
3045 	struct proto *prot = sk->sk_prot;
3046 	bool charged = false;
3047 	long allocated;
3048 
3049 	sk_memory_allocated_add(sk, amt);
3050 	allocated = sk_memory_allocated(sk);
3051 
3052 	if (memcg) {
3053 		if (!mem_cgroup_charge_skmem(memcg, amt, gfp_memcg_charge()))
3054 			goto suppress_allocation;
3055 		charged = true;
3056 	}
3057 
3058 	/* Under limit. */
3059 	if (allocated <= sk_prot_mem_limits(sk, 0)) {
3060 		sk_leave_memory_pressure(sk);
3061 		return 1;
3062 	}
3063 
3064 	/* Under pressure. */
3065 	if (allocated > sk_prot_mem_limits(sk, 1))
3066 		sk_enter_memory_pressure(sk);
3067 
3068 	/* Over hard limit. */
3069 	if (allocated > sk_prot_mem_limits(sk, 2))
3070 		goto suppress_allocation;
3071 
3072 	/* Guarantee minimum buffer size under pressure (either global
3073 	 * or memcg) to make sure features described in RFC 7323 (TCP
3074 	 * Extensions for High Performance) work properly.
3075 	 *
3076 	 * This rule does NOT stand when exceeds global or memcg's hard
3077 	 * limit, or else a DoS attack can be taken place by spawning
3078 	 * lots of sockets whose usage are under minimum buffer size.
3079 	 */
3080 	if (kind == SK_MEM_RECV) {
3081 		if (atomic_read(&sk->sk_rmem_alloc) < sk_get_rmem0(sk, prot))
3082 			return 1;
3083 
3084 	} else { /* SK_MEM_SEND */
3085 		int wmem0 = sk_get_wmem0(sk, prot);
3086 
3087 		if (sk->sk_type == SOCK_STREAM) {
3088 			if (sk->sk_wmem_queued < wmem0)
3089 				return 1;
3090 		} else if (refcount_read(&sk->sk_wmem_alloc) < wmem0) {
3091 				return 1;
3092 		}
3093 	}
3094 
3095 	if (sk_has_memory_pressure(sk)) {
3096 		u64 alloc;
3097 
3098 		/* The following 'average' heuristic is within the
3099 		 * scope of global accounting, so it only makes
3100 		 * sense for global memory pressure.
3101 		 */
3102 		if (!sk_under_global_memory_pressure(sk))
3103 			return 1;
3104 
3105 		/* Try to be fair among all the sockets under global
3106 		 * pressure by allowing the ones that below average
3107 		 * usage to raise.
3108 		 */
3109 		alloc = sk_sockets_allocated_read_positive(sk);
3110 		if (sk_prot_mem_limits(sk, 2) > alloc *
3111 		    sk_mem_pages(sk->sk_wmem_queued +
3112 				 atomic_read(&sk->sk_rmem_alloc) +
3113 				 sk->sk_forward_alloc))
3114 			return 1;
3115 	}
3116 
3117 suppress_allocation:
3118 
3119 	if (kind == SK_MEM_SEND && sk->sk_type == SOCK_STREAM) {
3120 		sk_stream_moderate_sndbuf(sk);
3121 
3122 		/* Fail only if socket is _under_ its sndbuf.
3123 		 * In this case we cannot block, so that we have to fail.
3124 		 */
3125 		if (sk->sk_wmem_queued + size >= sk->sk_sndbuf) {
3126 			/* Force charge with __GFP_NOFAIL */
3127 			if (memcg && !charged) {
3128 				mem_cgroup_charge_skmem(memcg, amt,
3129 					gfp_memcg_charge() | __GFP_NOFAIL);
3130 			}
3131 			return 1;
3132 		}
3133 	}
3134 
3135 	if (kind == SK_MEM_SEND || (kind == SK_MEM_RECV && charged))
3136 		trace_sock_exceed_buf_limit(sk, prot, allocated, kind);
3137 
3138 	sk_memory_allocated_sub(sk, amt);
3139 
3140 	if (charged)
3141 		mem_cgroup_uncharge_skmem(memcg, amt);
3142 
3143 	return 0;
3144 }
3145 
3146 /**
3147  *	__sk_mem_schedule - increase sk_forward_alloc and memory_allocated
3148  *	@sk: socket
3149  *	@size: memory size to allocate
3150  *	@kind: allocation type
3151  *
3152  *	If kind is SK_MEM_SEND, it means wmem allocation. Otherwise it means
3153  *	rmem allocation. This function assumes that protocols which have
3154  *	memory_pressure use sk_wmem_queued as write buffer accounting.
3155  */
3156 int __sk_mem_schedule(struct sock *sk, int size, int kind)
3157 {
3158 	int ret, amt = sk_mem_pages(size);
3159 
3160 	sk_forward_alloc_add(sk, amt << PAGE_SHIFT);
3161 	ret = __sk_mem_raise_allocated(sk, size, amt, kind);
3162 	if (!ret)
3163 		sk_forward_alloc_add(sk, -(amt << PAGE_SHIFT));
3164 	return ret;
3165 }
3166 EXPORT_SYMBOL(__sk_mem_schedule);
3167 
3168 /**
3169  *	__sk_mem_reduce_allocated - reclaim memory_allocated
3170  *	@sk: socket
3171  *	@amount: number of quanta
3172  *
3173  *	Similar to __sk_mem_reclaim(), but does not update sk_forward_alloc
3174  */
3175 void __sk_mem_reduce_allocated(struct sock *sk, int amount)
3176 {
3177 	sk_memory_allocated_sub(sk, amount);
3178 
3179 	if (mem_cgroup_sockets_enabled && sk->sk_memcg)
3180 		mem_cgroup_uncharge_skmem(sk->sk_memcg, amount);
3181 
3182 	if (sk_under_global_memory_pressure(sk) &&
3183 	    (sk_memory_allocated(sk) < sk_prot_mem_limits(sk, 0)))
3184 		sk_leave_memory_pressure(sk);
3185 }
3186 
3187 /**
3188  *	__sk_mem_reclaim - reclaim sk_forward_alloc and memory_allocated
3189  *	@sk: socket
3190  *	@amount: number of bytes (rounded down to a PAGE_SIZE multiple)
3191  */
3192 void __sk_mem_reclaim(struct sock *sk, int amount)
3193 {
3194 	amount >>= PAGE_SHIFT;
3195 	sk_forward_alloc_add(sk, -(amount << PAGE_SHIFT));
3196 	__sk_mem_reduce_allocated(sk, amount);
3197 }
3198 EXPORT_SYMBOL(__sk_mem_reclaim);
3199 
3200 int sk_set_peek_off(struct sock *sk, int val)
3201 {
3202 	WRITE_ONCE(sk->sk_peek_off, val);
3203 	return 0;
3204 }
3205 EXPORT_SYMBOL_GPL(sk_set_peek_off);
3206 
3207 /*
3208  * Set of default routines for initialising struct proto_ops when
3209  * the protocol does not support a particular function. In certain
3210  * cases where it makes no sense for a protocol to have a "do nothing"
3211  * function, some default processing is provided.
3212  */
3213 
3214 int sock_no_bind(struct socket *sock, struct sockaddr *saddr, int len)
3215 {
3216 	return -EOPNOTSUPP;
3217 }
3218 EXPORT_SYMBOL(sock_no_bind);
3219 
3220 int sock_no_connect(struct socket *sock, struct sockaddr *saddr,
3221 		    int len, int flags)
3222 {
3223 	return -EOPNOTSUPP;
3224 }
3225 EXPORT_SYMBOL(sock_no_connect);
3226 
3227 int sock_no_socketpair(struct socket *sock1, struct socket *sock2)
3228 {
3229 	return -EOPNOTSUPP;
3230 }
3231 EXPORT_SYMBOL(sock_no_socketpair);
3232 
3233 int sock_no_accept(struct socket *sock, struct socket *newsock, int flags,
3234 		   bool kern)
3235 {
3236 	return -EOPNOTSUPP;
3237 }
3238 EXPORT_SYMBOL(sock_no_accept);
3239 
3240 int sock_no_getname(struct socket *sock, struct sockaddr *saddr,
3241 		    int peer)
3242 {
3243 	return -EOPNOTSUPP;
3244 }
3245 EXPORT_SYMBOL(sock_no_getname);
3246 
3247 int sock_no_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
3248 {
3249 	return -EOPNOTSUPP;
3250 }
3251 EXPORT_SYMBOL(sock_no_ioctl);
3252 
3253 int sock_no_listen(struct socket *sock, int backlog)
3254 {
3255 	return -EOPNOTSUPP;
3256 }
3257 EXPORT_SYMBOL(sock_no_listen);
3258 
3259 int sock_no_shutdown(struct socket *sock, int how)
3260 {
3261 	return -EOPNOTSUPP;
3262 }
3263 EXPORT_SYMBOL(sock_no_shutdown);
3264 
3265 int sock_no_sendmsg(struct socket *sock, struct msghdr *m, size_t len)
3266 {
3267 	return -EOPNOTSUPP;
3268 }
3269 EXPORT_SYMBOL(sock_no_sendmsg);
3270 
3271 int sock_no_sendmsg_locked(struct sock *sk, struct msghdr *m, size_t len)
3272 {
3273 	return -EOPNOTSUPP;
3274 }
3275 EXPORT_SYMBOL(sock_no_sendmsg_locked);
3276 
3277 int sock_no_recvmsg(struct socket *sock, struct msghdr *m, size_t len,
3278 		    int flags)
3279 {
3280 	return -EOPNOTSUPP;
3281 }
3282 EXPORT_SYMBOL(sock_no_recvmsg);
3283 
3284 int sock_no_mmap(struct file *file, struct socket *sock, struct vm_area_struct *vma)
3285 {
3286 	/* Mirror missing mmap method error code */
3287 	return -ENODEV;
3288 }
3289 EXPORT_SYMBOL(sock_no_mmap);
3290 
3291 /*
3292  * When a file is received (via SCM_RIGHTS, etc), we must bump the
3293  * various sock-based usage counts.
3294  */
3295 void __receive_sock(struct file *file)
3296 {
3297 	struct socket *sock;
3298 
3299 	sock = sock_from_file(file);
3300 	if (sock) {
3301 		sock_update_netprioidx(&sock->sk->sk_cgrp_data);
3302 		sock_update_classid(&sock->sk->sk_cgrp_data);
3303 	}
3304 }
3305 
3306 /*
3307  *	Default Socket Callbacks
3308  */
3309 
3310 static void sock_def_wakeup(struct sock *sk)
3311 {
3312 	struct socket_wq *wq;
3313 
3314 	rcu_read_lock();
3315 	wq = rcu_dereference(sk->sk_wq);
3316 	if (skwq_has_sleeper(wq))
3317 		wake_up_interruptible_all(&wq->wait);
3318 	rcu_read_unlock();
3319 }
3320 
3321 static void sock_def_error_report(struct sock *sk)
3322 {
3323 	struct socket_wq *wq;
3324 
3325 	rcu_read_lock();
3326 	wq = rcu_dereference(sk->sk_wq);
3327 	if (skwq_has_sleeper(wq))
3328 		wake_up_interruptible_poll(&wq->wait, EPOLLERR);
3329 	sk_wake_async(sk, SOCK_WAKE_IO, POLL_ERR);
3330 	rcu_read_unlock();
3331 }
3332 
3333 void sock_def_readable(struct sock *sk)
3334 {
3335 	struct socket_wq *wq;
3336 
3337 	trace_sk_data_ready(sk);
3338 
3339 	rcu_read_lock();
3340 	wq = rcu_dereference(sk->sk_wq);
3341 	if (skwq_has_sleeper(wq))
3342 		wake_up_interruptible_sync_poll(&wq->wait, EPOLLIN | EPOLLPRI |
3343 						EPOLLRDNORM | EPOLLRDBAND);
3344 	sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
3345 	rcu_read_unlock();
3346 }
3347 
3348 static void sock_def_write_space(struct sock *sk)
3349 {
3350 	struct socket_wq *wq;
3351 
3352 	rcu_read_lock();
3353 
3354 	/* Do not wake up a writer until he can make "significant"
3355 	 * progress.  --DaveM
3356 	 */
3357 	if (sock_writeable(sk)) {
3358 		wq = rcu_dereference(sk->sk_wq);
3359 		if (skwq_has_sleeper(wq))
3360 			wake_up_interruptible_sync_poll(&wq->wait, EPOLLOUT |
3361 						EPOLLWRNORM | EPOLLWRBAND);
3362 
3363 		/* Should agree with poll, otherwise some programs break */
3364 		sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
3365 	}
3366 
3367 	rcu_read_unlock();
3368 }
3369 
3370 /* An optimised version of sock_def_write_space(), should only be called
3371  * for SOCK_RCU_FREE sockets under RCU read section and after putting
3372  * ->sk_wmem_alloc.
3373  */
3374 static void sock_def_write_space_wfree(struct sock *sk)
3375 {
3376 	/* Do not wake up a writer until he can make "significant"
3377 	 * progress.  --DaveM
3378 	 */
3379 	if (sock_writeable(sk)) {
3380 		struct socket_wq *wq = rcu_dereference(sk->sk_wq);
3381 
3382 		/* rely on refcount_sub from sock_wfree() */
3383 		smp_mb__after_atomic();
3384 		if (wq && waitqueue_active(&wq->wait))
3385 			wake_up_interruptible_sync_poll(&wq->wait, EPOLLOUT |
3386 						EPOLLWRNORM | EPOLLWRBAND);
3387 
3388 		/* Should agree with poll, otherwise some programs break */
3389 		sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
3390 	}
3391 }
3392 
3393 static void sock_def_destruct(struct sock *sk)
3394 {
3395 }
3396 
3397 void sk_send_sigurg(struct sock *sk)
3398 {
3399 	if (sk->sk_socket && sk->sk_socket->file)
3400 		if (send_sigurg(&sk->sk_socket->file->f_owner))
3401 			sk_wake_async(sk, SOCK_WAKE_URG, POLL_PRI);
3402 }
3403 EXPORT_SYMBOL(sk_send_sigurg);
3404 
3405 void sk_reset_timer(struct sock *sk, struct timer_list* timer,
3406 		    unsigned long expires)
3407 {
3408 	if (!mod_timer(timer, expires))
3409 		sock_hold(sk);
3410 }
3411 EXPORT_SYMBOL(sk_reset_timer);
3412 
3413 void sk_stop_timer(struct sock *sk, struct timer_list* timer)
3414 {
3415 	if (del_timer(timer))
3416 		__sock_put(sk);
3417 }
3418 EXPORT_SYMBOL(sk_stop_timer);
3419 
3420 void sk_stop_timer_sync(struct sock *sk, struct timer_list *timer)
3421 {
3422 	if (del_timer_sync(timer))
3423 		__sock_put(sk);
3424 }
3425 EXPORT_SYMBOL(sk_stop_timer_sync);
3426 
3427 void sock_init_data_uid(struct socket *sock, struct sock *sk, kuid_t uid)
3428 {
3429 	sk_init_common(sk);
3430 	sk->sk_send_head	=	NULL;
3431 
3432 	timer_setup(&sk->sk_timer, NULL, 0);
3433 
3434 	sk->sk_allocation	=	GFP_KERNEL;
3435 	sk->sk_rcvbuf		=	READ_ONCE(sysctl_rmem_default);
3436 	sk->sk_sndbuf		=	READ_ONCE(sysctl_wmem_default);
3437 	sk->sk_state		=	TCP_CLOSE;
3438 	sk->sk_use_task_frag	=	true;
3439 	sk_set_socket(sk, sock);
3440 
3441 	sock_set_flag(sk, SOCK_ZAPPED);
3442 
3443 	if (sock) {
3444 		sk->sk_type	=	sock->type;
3445 		RCU_INIT_POINTER(sk->sk_wq, &sock->wq);
3446 		sock->sk	=	sk;
3447 	} else {
3448 		RCU_INIT_POINTER(sk->sk_wq, NULL);
3449 	}
3450 	sk->sk_uid	=	uid;
3451 
3452 	rwlock_init(&sk->sk_callback_lock);
3453 	if (sk->sk_kern_sock)
3454 		lockdep_set_class_and_name(
3455 			&sk->sk_callback_lock,
3456 			af_kern_callback_keys + sk->sk_family,
3457 			af_family_kern_clock_key_strings[sk->sk_family]);
3458 	else
3459 		lockdep_set_class_and_name(
3460 			&sk->sk_callback_lock,
3461 			af_callback_keys + sk->sk_family,
3462 			af_family_clock_key_strings[sk->sk_family]);
3463 
3464 	sk->sk_state_change	=	sock_def_wakeup;
3465 	sk->sk_data_ready	=	sock_def_readable;
3466 	sk->sk_write_space	=	sock_def_write_space;
3467 	sk->sk_error_report	=	sock_def_error_report;
3468 	sk->sk_destruct		=	sock_def_destruct;
3469 
3470 	sk->sk_frag.page	=	NULL;
3471 	sk->sk_frag.offset	=	0;
3472 	sk->sk_peek_off		=	-1;
3473 
3474 	sk->sk_peer_pid 	=	NULL;
3475 	sk->sk_peer_cred	=	NULL;
3476 	spin_lock_init(&sk->sk_peer_lock);
3477 
3478 	sk->sk_write_pending	=	0;
3479 	sk->sk_rcvlowat		=	1;
3480 	sk->sk_rcvtimeo		=	MAX_SCHEDULE_TIMEOUT;
3481 	sk->sk_sndtimeo		=	MAX_SCHEDULE_TIMEOUT;
3482 
3483 	sk->sk_stamp = SK_DEFAULT_STAMP;
3484 #if BITS_PER_LONG==32
3485 	seqlock_init(&sk->sk_stamp_seq);
3486 #endif
3487 	atomic_set(&sk->sk_zckey, 0);
3488 
3489 #ifdef CONFIG_NET_RX_BUSY_POLL
3490 	sk->sk_napi_id		=	0;
3491 	sk->sk_ll_usec		=	READ_ONCE(sysctl_net_busy_read);
3492 #endif
3493 
3494 	sk->sk_max_pacing_rate = ~0UL;
3495 	sk->sk_pacing_rate = ~0UL;
3496 	WRITE_ONCE(sk->sk_pacing_shift, 10);
3497 	sk->sk_incoming_cpu = -1;
3498 
3499 	sk_rx_queue_clear(sk);
3500 	/*
3501 	 * Before updating sk_refcnt, we must commit prior changes to memory
3502 	 * (Documentation/RCU/rculist_nulls.rst for details)
3503 	 */
3504 	smp_wmb();
3505 	refcount_set(&sk->sk_refcnt, 1);
3506 	atomic_set(&sk->sk_drops, 0);
3507 }
3508 EXPORT_SYMBOL(sock_init_data_uid);
3509 
3510 void sock_init_data(struct socket *sock, struct sock *sk)
3511 {
3512 	kuid_t uid = sock ?
3513 		SOCK_INODE(sock)->i_uid :
3514 		make_kuid(sock_net(sk)->user_ns, 0);
3515 
3516 	sock_init_data_uid(sock, sk, uid);
3517 }
3518 EXPORT_SYMBOL(sock_init_data);
3519 
3520 void lock_sock_nested(struct sock *sk, int subclass)
3521 {
3522 	/* The sk_lock has mutex_lock() semantics here. */
3523 	mutex_acquire(&sk->sk_lock.dep_map, subclass, 0, _RET_IP_);
3524 
3525 	might_sleep();
3526 	spin_lock_bh(&sk->sk_lock.slock);
3527 	if (sock_owned_by_user_nocheck(sk))
3528 		__lock_sock(sk);
3529 	sk->sk_lock.owned = 1;
3530 	spin_unlock_bh(&sk->sk_lock.slock);
3531 }
3532 EXPORT_SYMBOL(lock_sock_nested);
3533 
3534 void release_sock(struct sock *sk)
3535 {
3536 	spin_lock_bh(&sk->sk_lock.slock);
3537 	if (sk->sk_backlog.tail)
3538 		__release_sock(sk);
3539 
3540 	if (sk->sk_prot->release_cb)
3541 		INDIRECT_CALL_INET_1(sk->sk_prot->release_cb,
3542 				     tcp_release_cb, sk);
3543 
3544 	sock_release_ownership(sk);
3545 	if (waitqueue_active(&sk->sk_lock.wq))
3546 		wake_up(&sk->sk_lock.wq);
3547 	spin_unlock_bh(&sk->sk_lock.slock);
3548 }
3549 EXPORT_SYMBOL(release_sock);
3550 
3551 bool __lock_sock_fast(struct sock *sk) __acquires(&sk->sk_lock.slock)
3552 {
3553 	might_sleep();
3554 	spin_lock_bh(&sk->sk_lock.slock);
3555 
3556 	if (!sock_owned_by_user_nocheck(sk)) {
3557 		/*
3558 		 * Fast path return with bottom halves disabled and
3559 		 * sock::sk_lock.slock held.
3560 		 *
3561 		 * The 'mutex' is not contended and holding
3562 		 * sock::sk_lock.slock prevents all other lockers to
3563 		 * proceed so the corresponding unlock_sock_fast() can
3564 		 * avoid the slow path of release_sock() completely and
3565 		 * just release slock.
3566 		 *
3567 		 * From a semantical POV this is equivalent to 'acquiring'
3568 		 * the 'mutex', hence the corresponding lockdep
3569 		 * mutex_release() has to happen in the fast path of
3570 		 * unlock_sock_fast().
3571 		 */
3572 		return false;
3573 	}
3574 
3575 	__lock_sock(sk);
3576 	sk->sk_lock.owned = 1;
3577 	__acquire(&sk->sk_lock.slock);
3578 	spin_unlock_bh(&sk->sk_lock.slock);
3579 	return true;
3580 }
3581 EXPORT_SYMBOL(__lock_sock_fast);
3582 
3583 int sock_gettstamp(struct socket *sock, void __user *userstamp,
3584 		   bool timeval, bool time32)
3585 {
3586 	struct sock *sk = sock->sk;
3587 	struct timespec64 ts;
3588 
3589 	sock_enable_timestamp(sk, SOCK_TIMESTAMP);
3590 	ts = ktime_to_timespec64(sock_read_timestamp(sk));
3591 	if (ts.tv_sec == -1)
3592 		return -ENOENT;
3593 	if (ts.tv_sec == 0) {
3594 		ktime_t kt = ktime_get_real();
3595 		sock_write_timestamp(sk, kt);
3596 		ts = ktime_to_timespec64(kt);
3597 	}
3598 
3599 	if (timeval)
3600 		ts.tv_nsec /= 1000;
3601 
3602 #ifdef CONFIG_COMPAT_32BIT_TIME
3603 	if (time32)
3604 		return put_old_timespec32(&ts, userstamp);
3605 #endif
3606 #ifdef CONFIG_SPARC64
3607 	/* beware of padding in sparc64 timeval */
3608 	if (timeval && !in_compat_syscall()) {
3609 		struct __kernel_old_timeval __user tv = {
3610 			.tv_sec = ts.tv_sec,
3611 			.tv_usec = ts.tv_nsec,
3612 		};
3613 		if (copy_to_user(userstamp, &tv, sizeof(tv)))
3614 			return -EFAULT;
3615 		return 0;
3616 	}
3617 #endif
3618 	return put_timespec64(&ts, userstamp);
3619 }
3620 EXPORT_SYMBOL(sock_gettstamp);
3621 
3622 void sock_enable_timestamp(struct sock *sk, enum sock_flags flag)
3623 {
3624 	if (!sock_flag(sk, flag)) {
3625 		unsigned long previous_flags = sk->sk_flags;
3626 
3627 		sock_set_flag(sk, flag);
3628 		/*
3629 		 * we just set one of the two flags which require net
3630 		 * time stamping, but time stamping might have been on
3631 		 * already because of the other one
3632 		 */
3633 		if (sock_needs_netstamp(sk) &&
3634 		    !(previous_flags & SK_FLAGS_TIMESTAMP))
3635 			net_enable_timestamp();
3636 	}
3637 }
3638 
3639 int sock_recv_errqueue(struct sock *sk, struct msghdr *msg, int len,
3640 		       int level, int type)
3641 {
3642 	struct sock_exterr_skb *serr;
3643 	struct sk_buff *skb;
3644 	int copied, err;
3645 
3646 	err = -EAGAIN;
3647 	skb = sock_dequeue_err_skb(sk);
3648 	if (skb == NULL)
3649 		goto out;
3650 
3651 	copied = skb->len;
3652 	if (copied > len) {
3653 		msg->msg_flags |= MSG_TRUNC;
3654 		copied = len;
3655 	}
3656 	err = skb_copy_datagram_msg(skb, 0, msg, copied);
3657 	if (err)
3658 		goto out_free_skb;
3659 
3660 	sock_recv_timestamp(msg, sk, skb);
3661 
3662 	serr = SKB_EXT_ERR(skb);
3663 	put_cmsg(msg, level, type, sizeof(serr->ee), &serr->ee);
3664 
3665 	msg->msg_flags |= MSG_ERRQUEUE;
3666 	err = copied;
3667 
3668 out_free_skb:
3669 	kfree_skb(skb);
3670 out:
3671 	return err;
3672 }
3673 EXPORT_SYMBOL(sock_recv_errqueue);
3674 
3675 /*
3676  *	Get a socket option on an socket.
3677  *
3678  *	FIX: POSIX 1003.1g is very ambiguous here. It states that
3679  *	asynchronous errors should be reported by getsockopt. We assume
3680  *	this means if you specify SO_ERROR (otherwise whats the point of it).
3681  */
3682 int sock_common_getsockopt(struct socket *sock, int level, int optname,
3683 			   char __user *optval, int __user *optlen)
3684 {
3685 	struct sock *sk = sock->sk;
3686 
3687 	/* IPV6_ADDRFORM can change sk->sk_prot under us. */
3688 	return READ_ONCE(sk->sk_prot)->getsockopt(sk, level, optname, optval, optlen);
3689 }
3690 EXPORT_SYMBOL(sock_common_getsockopt);
3691 
3692 int sock_common_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
3693 			int flags)
3694 {
3695 	struct sock *sk = sock->sk;
3696 	int addr_len = 0;
3697 	int err;
3698 
3699 	err = sk->sk_prot->recvmsg(sk, msg, size, flags, &addr_len);
3700 	if (err >= 0)
3701 		msg->msg_namelen = addr_len;
3702 	return err;
3703 }
3704 EXPORT_SYMBOL(sock_common_recvmsg);
3705 
3706 /*
3707  *	Set socket options on an inet socket.
3708  */
3709 int sock_common_setsockopt(struct socket *sock, int level, int optname,
3710 			   sockptr_t optval, unsigned int optlen)
3711 {
3712 	struct sock *sk = sock->sk;
3713 
3714 	/* IPV6_ADDRFORM can change sk->sk_prot under us. */
3715 	return READ_ONCE(sk->sk_prot)->setsockopt(sk, level, optname, optval, optlen);
3716 }
3717 EXPORT_SYMBOL(sock_common_setsockopt);
3718 
3719 void sk_common_release(struct sock *sk)
3720 {
3721 	if (sk->sk_prot->destroy)
3722 		sk->sk_prot->destroy(sk);
3723 
3724 	/*
3725 	 * Observation: when sk_common_release is called, processes have
3726 	 * no access to socket. But net still has.
3727 	 * Step one, detach it from networking:
3728 	 *
3729 	 * A. Remove from hash tables.
3730 	 */
3731 
3732 	sk->sk_prot->unhash(sk);
3733 
3734 	/*
3735 	 * In this point socket cannot receive new packets, but it is possible
3736 	 * that some packets are in flight because some CPU runs receiver and
3737 	 * did hash table lookup before we unhashed socket. They will achieve
3738 	 * receive queue and will be purged by socket destructor.
3739 	 *
3740 	 * Also we still have packets pending on receive queue and probably,
3741 	 * our own packets waiting in device queues. sock_destroy will drain
3742 	 * receive queue, but transmitted packets will delay socket destruction
3743 	 * until the last reference will be released.
3744 	 */
3745 
3746 	sock_orphan(sk);
3747 
3748 	xfrm_sk_free_policy(sk);
3749 
3750 	sock_put(sk);
3751 }
3752 EXPORT_SYMBOL(sk_common_release);
3753 
3754 void sk_get_meminfo(const struct sock *sk, u32 *mem)
3755 {
3756 	memset(mem, 0, sizeof(*mem) * SK_MEMINFO_VARS);
3757 
3758 	mem[SK_MEMINFO_RMEM_ALLOC] = sk_rmem_alloc_get(sk);
3759 	mem[SK_MEMINFO_RCVBUF] = READ_ONCE(sk->sk_rcvbuf);
3760 	mem[SK_MEMINFO_WMEM_ALLOC] = sk_wmem_alloc_get(sk);
3761 	mem[SK_MEMINFO_SNDBUF] = READ_ONCE(sk->sk_sndbuf);
3762 	mem[SK_MEMINFO_FWD_ALLOC] = sk_forward_alloc_get(sk);
3763 	mem[SK_MEMINFO_WMEM_QUEUED] = READ_ONCE(sk->sk_wmem_queued);
3764 	mem[SK_MEMINFO_OPTMEM] = atomic_read(&sk->sk_omem_alloc);
3765 	mem[SK_MEMINFO_BACKLOG] = READ_ONCE(sk->sk_backlog.len);
3766 	mem[SK_MEMINFO_DROPS] = atomic_read(&sk->sk_drops);
3767 }
3768 
3769 #ifdef CONFIG_PROC_FS
3770 static DECLARE_BITMAP(proto_inuse_idx, PROTO_INUSE_NR);
3771 
3772 int sock_prot_inuse_get(struct net *net, struct proto *prot)
3773 {
3774 	int cpu, idx = prot->inuse_idx;
3775 	int res = 0;
3776 
3777 	for_each_possible_cpu(cpu)
3778 		res += per_cpu_ptr(net->core.prot_inuse, cpu)->val[idx];
3779 
3780 	return res >= 0 ? res : 0;
3781 }
3782 EXPORT_SYMBOL_GPL(sock_prot_inuse_get);
3783 
3784 int sock_inuse_get(struct net *net)
3785 {
3786 	int cpu, res = 0;
3787 
3788 	for_each_possible_cpu(cpu)
3789 		res += per_cpu_ptr(net->core.prot_inuse, cpu)->all;
3790 
3791 	return res;
3792 }
3793 
3794 EXPORT_SYMBOL_GPL(sock_inuse_get);
3795 
3796 static int __net_init sock_inuse_init_net(struct net *net)
3797 {
3798 	net->core.prot_inuse = alloc_percpu(struct prot_inuse);
3799 	if (net->core.prot_inuse == NULL)
3800 		return -ENOMEM;
3801 	return 0;
3802 }
3803 
3804 static void __net_exit sock_inuse_exit_net(struct net *net)
3805 {
3806 	free_percpu(net->core.prot_inuse);
3807 }
3808 
3809 static struct pernet_operations net_inuse_ops = {
3810 	.init = sock_inuse_init_net,
3811 	.exit = sock_inuse_exit_net,
3812 };
3813 
3814 static __init int net_inuse_init(void)
3815 {
3816 	if (register_pernet_subsys(&net_inuse_ops))
3817 		panic("Cannot initialize net inuse counters");
3818 
3819 	return 0;
3820 }
3821 
3822 core_initcall(net_inuse_init);
3823 
3824 static int assign_proto_idx(struct proto *prot)
3825 {
3826 	prot->inuse_idx = find_first_zero_bit(proto_inuse_idx, PROTO_INUSE_NR);
3827 
3828 	if (unlikely(prot->inuse_idx == PROTO_INUSE_NR - 1)) {
3829 		pr_err("PROTO_INUSE_NR exhausted\n");
3830 		return -ENOSPC;
3831 	}
3832 
3833 	set_bit(prot->inuse_idx, proto_inuse_idx);
3834 	return 0;
3835 }
3836 
3837 static void release_proto_idx(struct proto *prot)
3838 {
3839 	if (prot->inuse_idx != PROTO_INUSE_NR - 1)
3840 		clear_bit(prot->inuse_idx, proto_inuse_idx);
3841 }
3842 #else
3843 static inline int assign_proto_idx(struct proto *prot)
3844 {
3845 	return 0;
3846 }
3847 
3848 static inline void release_proto_idx(struct proto *prot)
3849 {
3850 }
3851 
3852 #endif
3853 
3854 static void tw_prot_cleanup(struct timewait_sock_ops *twsk_prot)
3855 {
3856 	if (!twsk_prot)
3857 		return;
3858 	kfree(twsk_prot->twsk_slab_name);
3859 	twsk_prot->twsk_slab_name = NULL;
3860 	kmem_cache_destroy(twsk_prot->twsk_slab);
3861 	twsk_prot->twsk_slab = NULL;
3862 }
3863 
3864 static int tw_prot_init(const struct proto *prot)
3865 {
3866 	struct timewait_sock_ops *twsk_prot = prot->twsk_prot;
3867 
3868 	if (!twsk_prot)
3869 		return 0;
3870 
3871 	twsk_prot->twsk_slab_name = kasprintf(GFP_KERNEL, "tw_sock_%s",
3872 					      prot->name);
3873 	if (!twsk_prot->twsk_slab_name)
3874 		return -ENOMEM;
3875 
3876 	twsk_prot->twsk_slab =
3877 		kmem_cache_create(twsk_prot->twsk_slab_name,
3878 				  twsk_prot->twsk_obj_size, 0,
3879 				  SLAB_ACCOUNT | prot->slab_flags,
3880 				  NULL);
3881 	if (!twsk_prot->twsk_slab) {
3882 		pr_crit("%s: Can't create timewait sock SLAB cache!\n",
3883 			prot->name);
3884 		return -ENOMEM;
3885 	}
3886 
3887 	return 0;
3888 }
3889 
3890 static void req_prot_cleanup(struct request_sock_ops *rsk_prot)
3891 {
3892 	if (!rsk_prot)
3893 		return;
3894 	kfree(rsk_prot->slab_name);
3895 	rsk_prot->slab_name = NULL;
3896 	kmem_cache_destroy(rsk_prot->slab);
3897 	rsk_prot->slab = NULL;
3898 }
3899 
3900 static int req_prot_init(const struct proto *prot)
3901 {
3902 	struct request_sock_ops *rsk_prot = prot->rsk_prot;
3903 
3904 	if (!rsk_prot)
3905 		return 0;
3906 
3907 	rsk_prot->slab_name = kasprintf(GFP_KERNEL, "request_sock_%s",
3908 					prot->name);
3909 	if (!rsk_prot->slab_name)
3910 		return -ENOMEM;
3911 
3912 	rsk_prot->slab = kmem_cache_create(rsk_prot->slab_name,
3913 					   rsk_prot->obj_size, 0,
3914 					   SLAB_ACCOUNT | prot->slab_flags,
3915 					   NULL);
3916 
3917 	if (!rsk_prot->slab) {
3918 		pr_crit("%s: Can't create request sock SLAB cache!\n",
3919 			prot->name);
3920 		return -ENOMEM;
3921 	}
3922 	return 0;
3923 }
3924 
3925 int proto_register(struct proto *prot, int alloc_slab)
3926 {
3927 	int ret = -ENOBUFS;
3928 
3929 	if (prot->memory_allocated && !prot->sysctl_mem) {
3930 		pr_err("%s: missing sysctl_mem\n", prot->name);
3931 		return -EINVAL;
3932 	}
3933 	if (prot->memory_allocated && !prot->per_cpu_fw_alloc) {
3934 		pr_err("%s: missing per_cpu_fw_alloc\n", prot->name);
3935 		return -EINVAL;
3936 	}
3937 	if (alloc_slab) {
3938 		prot->slab = kmem_cache_create_usercopy(prot->name,
3939 					prot->obj_size, 0,
3940 					SLAB_HWCACHE_ALIGN | SLAB_ACCOUNT |
3941 					prot->slab_flags,
3942 					prot->useroffset, prot->usersize,
3943 					NULL);
3944 
3945 		if (prot->slab == NULL) {
3946 			pr_crit("%s: Can't create sock SLAB cache!\n",
3947 				prot->name);
3948 			goto out;
3949 		}
3950 
3951 		if (req_prot_init(prot))
3952 			goto out_free_request_sock_slab;
3953 
3954 		if (tw_prot_init(prot))
3955 			goto out_free_timewait_sock_slab;
3956 	}
3957 
3958 	mutex_lock(&proto_list_mutex);
3959 	ret = assign_proto_idx(prot);
3960 	if (ret) {
3961 		mutex_unlock(&proto_list_mutex);
3962 		goto out_free_timewait_sock_slab;
3963 	}
3964 	list_add(&prot->node, &proto_list);
3965 	mutex_unlock(&proto_list_mutex);
3966 	return ret;
3967 
3968 out_free_timewait_sock_slab:
3969 	if (alloc_slab)
3970 		tw_prot_cleanup(prot->twsk_prot);
3971 out_free_request_sock_slab:
3972 	if (alloc_slab) {
3973 		req_prot_cleanup(prot->rsk_prot);
3974 
3975 		kmem_cache_destroy(prot->slab);
3976 		prot->slab = NULL;
3977 	}
3978 out:
3979 	return ret;
3980 }
3981 EXPORT_SYMBOL(proto_register);
3982 
3983 void proto_unregister(struct proto *prot)
3984 {
3985 	mutex_lock(&proto_list_mutex);
3986 	release_proto_idx(prot);
3987 	list_del(&prot->node);
3988 	mutex_unlock(&proto_list_mutex);
3989 
3990 	kmem_cache_destroy(prot->slab);
3991 	prot->slab = NULL;
3992 
3993 	req_prot_cleanup(prot->rsk_prot);
3994 	tw_prot_cleanup(prot->twsk_prot);
3995 }
3996 EXPORT_SYMBOL(proto_unregister);
3997 
3998 int sock_load_diag_module(int family, int protocol)
3999 {
4000 	if (!protocol) {
4001 		if (!sock_is_registered(family))
4002 			return -ENOENT;
4003 
4004 		return request_module("net-pf-%d-proto-%d-type-%d", PF_NETLINK,
4005 				      NETLINK_SOCK_DIAG, family);
4006 	}
4007 
4008 #ifdef CONFIG_INET
4009 	if (family == AF_INET &&
4010 	    protocol != IPPROTO_RAW &&
4011 	    protocol < MAX_INET_PROTOS &&
4012 	    !rcu_access_pointer(inet_protos[protocol]))
4013 		return -ENOENT;
4014 #endif
4015 
4016 	return request_module("net-pf-%d-proto-%d-type-%d-%d", PF_NETLINK,
4017 			      NETLINK_SOCK_DIAG, family, protocol);
4018 }
4019 EXPORT_SYMBOL(sock_load_diag_module);
4020 
4021 #ifdef CONFIG_PROC_FS
4022 static void *proto_seq_start(struct seq_file *seq, loff_t *pos)
4023 	__acquires(proto_list_mutex)
4024 {
4025 	mutex_lock(&proto_list_mutex);
4026 	return seq_list_start_head(&proto_list, *pos);
4027 }
4028 
4029 static void *proto_seq_next(struct seq_file *seq, void *v, loff_t *pos)
4030 {
4031 	return seq_list_next(v, &proto_list, pos);
4032 }
4033 
4034 static void proto_seq_stop(struct seq_file *seq, void *v)
4035 	__releases(proto_list_mutex)
4036 {
4037 	mutex_unlock(&proto_list_mutex);
4038 }
4039 
4040 static char proto_method_implemented(const void *method)
4041 {
4042 	return method == NULL ? 'n' : 'y';
4043 }
4044 static long sock_prot_memory_allocated(struct proto *proto)
4045 {
4046 	return proto->memory_allocated != NULL ? proto_memory_allocated(proto) : -1L;
4047 }
4048 
4049 static const char *sock_prot_memory_pressure(struct proto *proto)
4050 {
4051 	return proto->memory_pressure != NULL ?
4052 	proto_memory_pressure(proto) ? "yes" : "no" : "NI";
4053 }
4054 
4055 static void proto_seq_printf(struct seq_file *seq, struct proto *proto)
4056 {
4057 
4058 	seq_printf(seq, "%-9s %4u %6d  %6ld   %-3s %6u   %-3s  %-10s "
4059 			"%2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c\n",
4060 		   proto->name,
4061 		   proto->obj_size,
4062 		   sock_prot_inuse_get(seq_file_net(seq), proto),
4063 		   sock_prot_memory_allocated(proto),
4064 		   sock_prot_memory_pressure(proto),
4065 		   proto->max_header,
4066 		   proto->slab == NULL ? "no" : "yes",
4067 		   module_name(proto->owner),
4068 		   proto_method_implemented(proto->close),
4069 		   proto_method_implemented(proto->connect),
4070 		   proto_method_implemented(proto->disconnect),
4071 		   proto_method_implemented(proto->accept),
4072 		   proto_method_implemented(proto->ioctl),
4073 		   proto_method_implemented(proto->init),
4074 		   proto_method_implemented(proto->destroy),
4075 		   proto_method_implemented(proto->shutdown),
4076 		   proto_method_implemented(proto->setsockopt),
4077 		   proto_method_implemented(proto->getsockopt),
4078 		   proto_method_implemented(proto->sendmsg),
4079 		   proto_method_implemented(proto->recvmsg),
4080 		   proto_method_implemented(proto->bind),
4081 		   proto_method_implemented(proto->backlog_rcv),
4082 		   proto_method_implemented(proto->hash),
4083 		   proto_method_implemented(proto->unhash),
4084 		   proto_method_implemented(proto->get_port),
4085 		   proto_method_implemented(proto->enter_memory_pressure));
4086 }
4087 
4088 static int proto_seq_show(struct seq_file *seq, void *v)
4089 {
4090 	if (v == &proto_list)
4091 		seq_printf(seq, "%-9s %-4s %-8s %-6s %-5s %-7s %-4s %-10s %s",
4092 			   "protocol",
4093 			   "size",
4094 			   "sockets",
4095 			   "memory",
4096 			   "press",
4097 			   "maxhdr",
4098 			   "slab",
4099 			   "module",
4100 			   "cl co di ac io in de sh ss gs se re bi br ha uh gp em\n");
4101 	else
4102 		proto_seq_printf(seq, list_entry(v, struct proto, node));
4103 	return 0;
4104 }
4105 
4106 static const struct seq_operations proto_seq_ops = {
4107 	.start  = proto_seq_start,
4108 	.next   = proto_seq_next,
4109 	.stop   = proto_seq_stop,
4110 	.show   = proto_seq_show,
4111 };
4112 
4113 static __net_init int proto_init_net(struct net *net)
4114 {
4115 	if (!proc_create_net("protocols", 0444, net->proc_net, &proto_seq_ops,
4116 			sizeof(struct seq_net_private)))
4117 		return -ENOMEM;
4118 
4119 	return 0;
4120 }
4121 
4122 static __net_exit void proto_exit_net(struct net *net)
4123 {
4124 	remove_proc_entry("protocols", net->proc_net);
4125 }
4126 
4127 
4128 static __net_initdata struct pernet_operations proto_net_ops = {
4129 	.init = proto_init_net,
4130 	.exit = proto_exit_net,
4131 };
4132 
4133 static int __init proto_init(void)
4134 {
4135 	return register_pernet_subsys(&proto_net_ops);
4136 }
4137 
4138 subsys_initcall(proto_init);
4139 
4140 #endif /* PROC_FS */
4141 
4142 #ifdef CONFIG_NET_RX_BUSY_POLL
4143 bool sk_busy_loop_end(void *p, unsigned long start_time)
4144 {
4145 	struct sock *sk = p;
4146 
4147 	return !skb_queue_empty_lockless(&sk->sk_receive_queue) ||
4148 	       sk_busy_loop_timeout(sk, start_time);
4149 }
4150 EXPORT_SYMBOL(sk_busy_loop_end);
4151 #endif /* CONFIG_NET_RX_BUSY_POLL */
4152 
4153 int sock_bind_add(struct sock *sk, struct sockaddr *addr, int addr_len)
4154 {
4155 	if (!sk->sk_prot->bind_add)
4156 		return -EOPNOTSUPP;
4157 	return sk->sk_prot->bind_add(sk, addr, addr_len);
4158 }
4159 EXPORT_SYMBOL(sock_bind_add);
4160 
4161 /* Copy 'size' bytes from userspace and return `size` back to userspace */
4162 int sock_ioctl_inout(struct sock *sk, unsigned int cmd,
4163 		     void __user *arg, void *karg, size_t size)
4164 {
4165 	int ret;
4166 
4167 	if (copy_from_user(karg, arg, size))
4168 		return -EFAULT;
4169 
4170 	ret = READ_ONCE(sk->sk_prot)->ioctl(sk, cmd, karg);
4171 	if (ret)
4172 		return ret;
4173 
4174 	if (copy_to_user(arg, karg, size))
4175 		return -EFAULT;
4176 
4177 	return 0;
4178 }
4179 EXPORT_SYMBOL(sock_ioctl_inout);
4180 
4181 /* This is the most common ioctl prep function, where the result (4 bytes) is
4182  * copied back to userspace if the ioctl() returns successfully. No input is
4183  * copied from userspace as input argument.
4184  */
4185 static int sock_ioctl_out(struct sock *sk, unsigned int cmd, void __user *arg)
4186 {
4187 	int ret, karg = 0;
4188 
4189 	ret = READ_ONCE(sk->sk_prot)->ioctl(sk, cmd, &karg);
4190 	if (ret)
4191 		return ret;
4192 
4193 	return put_user(karg, (int __user *)arg);
4194 }
4195 
4196 /* A wrapper around sock ioctls, which copies the data from userspace
4197  * (depending on the protocol/ioctl), and copies back the result to userspace.
4198  * The main motivation for this function is to pass kernel memory to the
4199  * protocol ioctl callbacks, instead of userspace memory.
4200  */
4201 int sk_ioctl(struct sock *sk, unsigned int cmd, void __user *arg)
4202 {
4203 	int rc = 1;
4204 
4205 	if (sk->sk_type == SOCK_RAW && sk->sk_family == AF_INET)
4206 		rc = ipmr_sk_ioctl(sk, cmd, arg);
4207 	else if (sk->sk_type == SOCK_RAW && sk->sk_family == AF_INET6)
4208 		rc = ip6mr_sk_ioctl(sk, cmd, arg);
4209 	else if (sk_is_phonet(sk))
4210 		rc = phonet_sk_ioctl(sk, cmd, arg);
4211 
4212 	/* If ioctl was processed, returns its value */
4213 	if (rc <= 0)
4214 		return rc;
4215 
4216 	/* Otherwise call the default handler */
4217 	return sock_ioctl_out(sk, cmd, arg);
4218 }
4219 EXPORT_SYMBOL(sk_ioctl);
4220