xref: /openbmc/linux/net/core/sock.c (revision 3a35093a)
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 
118 #include <linux/uaccess.h>
119 
120 #include <linux/netdevice.h>
121 #include <net/protocol.h>
122 #include <linux/skbuff.h>
123 #include <net/net_namespace.h>
124 #include <net/request_sock.h>
125 #include <net/sock.h>
126 #include <linux/net_tstamp.h>
127 #include <net/xfrm.h>
128 #include <linux/ipsec.h>
129 #include <net/cls_cgroup.h>
130 #include <net/netprio_cgroup.h>
131 #include <linux/sock_diag.h>
132 
133 #include <linux/filter.h>
134 #include <net/sock_reuseport.h>
135 #include <net/bpf_sk_storage.h>
136 
137 #include <trace/events/sock.h>
138 
139 #include <net/tcp.h>
140 #include <net/busy_poll.h>
141 
142 static DEFINE_MUTEX(proto_list_mutex);
143 static LIST_HEAD(proto_list);
144 
145 static void sock_inuse_add(struct net *net, int val);
146 
147 /**
148  * sk_ns_capable - General socket capability test
149  * @sk: Socket to use a capability on or through
150  * @user_ns: The user namespace of the capability to use
151  * @cap: The capability to use
152  *
153  * Test to see if the opener of the socket had when the socket was
154  * created and the current process has the capability @cap in the user
155  * namespace @user_ns.
156  */
157 bool sk_ns_capable(const struct sock *sk,
158 		   struct user_namespace *user_ns, int cap)
159 {
160 	return file_ns_capable(sk->sk_socket->file, user_ns, cap) &&
161 		ns_capable(user_ns, cap);
162 }
163 EXPORT_SYMBOL(sk_ns_capable);
164 
165 /**
166  * sk_capable - Socket global capability test
167  * @sk: Socket to use a capability on or through
168  * @cap: The global capability to use
169  *
170  * Test to see if the opener of the socket had when the socket was
171  * created and the current process has the capability @cap in all user
172  * namespaces.
173  */
174 bool sk_capable(const struct sock *sk, int cap)
175 {
176 	return sk_ns_capable(sk, &init_user_ns, cap);
177 }
178 EXPORT_SYMBOL(sk_capable);
179 
180 /**
181  * sk_net_capable - Network namespace socket capability test
182  * @sk: Socket to use a capability on or through
183  * @cap: The capability to use
184  *
185  * Test to see if the opener of the socket had when the socket was created
186  * and the current process has the capability @cap over the network namespace
187  * the socket is a member of.
188  */
189 bool sk_net_capable(const struct sock *sk, int cap)
190 {
191 	return sk_ns_capable(sk, sock_net(sk)->user_ns, cap);
192 }
193 EXPORT_SYMBOL(sk_net_capable);
194 
195 /*
196  * Each address family might have different locking rules, so we have
197  * one slock key per address family and separate keys for internal and
198  * userspace sockets.
199  */
200 static struct lock_class_key af_family_keys[AF_MAX];
201 static struct lock_class_key af_family_kern_keys[AF_MAX];
202 static struct lock_class_key af_family_slock_keys[AF_MAX];
203 static struct lock_class_key af_family_kern_slock_keys[AF_MAX];
204 
205 /*
206  * Make lock validator output more readable. (we pre-construct these
207  * strings build-time, so that runtime initialization of socket
208  * locks is fast):
209  */
210 
211 #define _sock_locks(x)						  \
212   x "AF_UNSPEC",	x "AF_UNIX"     ,	x "AF_INET"     , \
213   x "AF_AX25"  ,	x "AF_IPX"      ,	x "AF_APPLETALK", \
214   x "AF_NETROM",	x "AF_BRIDGE"   ,	x "AF_ATMPVC"   , \
215   x "AF_X25"   ,	x "AF_INET6"    ,	x "AF_ROSE"     , \
216   x "AF_DECnet",	x "AF_NETBEUI"  ,	x "AF_SECURITY" , \
217   x "AF_KEY"   ,	x "AF_NETLINK"  ,	x "AF_PACKET"   , \
218   x "AF_ASH"   ,	x "AF_ECONET"   ,	x "AF_ATMSVC"   , \
219   x "AF_RDS"   ,	x "AF_SNA"      ,	x "AF_IRDA"     , \
220   x "AF_PPPOX" ,	x "AF_WANPIPE"  ,	x "AF_LLC"      , \
221   x "27"       ,	x "28"          ,	x "AF_CAN"      , \
222   x "AF_TIPC"  ,	x "AF_BLUETOOTH",	x "IUCV"        , \
223   x "AF_RXRPC" ,	x "AF_ISDN"     ,	x "AF_PHONET"   , \
224   x "AF_IEEE802154",	x "AF_CAIF"	,	x "AF_ALG"      , \
225   x "AF_NFC"   ,	x "AF_VSOCK"    ,	x "AF_KCM"      , \
226   x "AF_QIPCRTR",	x "AF_SMC"	,	x "AF_XDP"	, \
227   x "AF_MAX"
228 
229 static const char *const af_family_key_strings[AF_MAX+1] = {
230 	_sock_locks("sk_lock-")
231 };
232 static const char *const af_family_slock_key_strings[AF_MAX+1] = {
233 	_sock_locks("slock-")
234 };
235 static const char *const af_family_clock_key_strings[AF_MAX+1] = {
236 	_sock_locks("clock-")
237 };
238 
239 static const char *const af_family_kern_key_strings[AF_MAX+1] = {
240 	_sock_locks("k-sk_lock-")
241 };
242 static const char *const af_family_kern_slock_key_strings[AF_MAX+1] = {
243 	_sock_locks("k-slock-")
244 };
245 static const char *const af_family_kern_clock_key_strings[AF_MAX+1] = {
246 	_sock_locks("k-clock-")
247 };
248 static const char *const af_family_rlock_key_strings[AF_MAX+1] = {
249 	_sock_locks("rlock-")
250 };
251 static const char *const af_family_wlock_key_strings[AF_MAX+1] = {
252 	_sock_locks("wlock-")
253 };
254 static const char *const af_family_elock_key_strings[AF_MAX+1] = {
255 	_sock_locks("elock-")
256 };
257 
258 /*
259  * sk_callback_lock and sk queues locking rules are per-address-family,
260  * so split the lock classes by using a per-AF key:
261  */
262 static struct lock_class_key af_callback_keys[AF_MAX];
263 static struct lock_class_key af_rlock_keys[AF_MAX];
264 static struct lock_class_key af_wlock_keys[AF_MAX];
265 static struct lock_class_key af_elock_keys[AF_MAX];
266 static struct lock_class_key af_kern_callback_keys[AF_MAX];
267 
268 /* Run time adjustable parameters. */
269 __u32 sysctl_wmem_max __read_mostly = SK_WMEM_MAX;
270 EXPORT_SYMBOL(sysctl_wmem_max);
271 __u32 sysctl_rmem_max __read_mostly = SK_RMEM_MAX;
272 EXPORT_SYMBOL(sysctl_rmem_max);
273 __u32 sysctl_wmem_default __read_mostly = SK_WMEM_MAX;
274 __u32 sysctl_rmem_default __read_mostly = SK_RMEM_MAX;
275 
276 /* Maximal space eaten by iovec or ancillary data plus some space */
277 int sysctl_optmem_max __read_mostly = sizeof(unsigned long)*(2*UIO_MAXIOV+512);
278 EXPORT_SYMBOL(sysctl_optmem_max);
279 
280 int sysctl_tstamp_allow_data __read_mostly = 1;
281 
282 DEFINE_STATIC_KEY_FALSE(memalloc_socks_key);
283 EXPORT_SYMBOL_GPL(memalloc_socks_key);
284 
285 /**
286  * sk_set_memalloc - sets %SOCK_MEMALLOC
287  * @sk: socket to set it on
288  *
289  * Set %SOCK_MEMALLOC on a socket for access to emergency reserves.
290  * It's the responsibility of the admin to adjust min_free_kbytes
291  * to meet the requirements
292  */
293 void sk_set_memalloc(struct sock *sk)
294 {
295 	sock_set_flag(sk, SOCK_MEMALLOC);
296 	sk->sk_allocation |= __GFP_MEMALLOC;
297 	static_branch_inc(&memalloc_socks_key);
298 }
299 EXPORT_SYMBOL_GPL(sk_set_memalloc);
300 
301 void sk_clear_memalloc(struct sock *sk)
302 {
303 	sock_reset_flag(sk, SOCK_MEMALLOC);
304 	sk->sk_allocation &= ~__GFP_MEMALLOC;
305 	static_branch_dec(&memalloc_socks_key);
306 
307 	/*
308 	 * SOCK_MEMALLOC is allowed to ignore rmem limits to ensure forward
309 	 * progress of swapping. SOCK_MEMALLOC may be cleared while
310 	 * it has rmem allocations due to the last swapfile being deactivated
311 	 * but there is a risk that the socket is unusable due to exceeding
312 	 * the rmem limits. Reclaim the reserves and obey rmem limits again.
313 	 */
314 	sk_mem_reclaim(sk);
315 }
316 EXPORT_SYMBOL_GPL(sk_clear_memalloc);
317 
318 int __sk_backlog_rcv(struct sock *sk, struct sk_buff *skb)
319 {
320 	int ret;
321 	unsigned int noreclaim_flag;
322 
323 	/* these should have been dropped before queueing */
324 	BUG_ON(!sock_flag(sk, SOCK_MEMALLOC));
325 
326 	noreclaim_flag = memalloc_noreclaim_save();
327 	ret = sk->sk_backlog_rcv(sk, skb);
328 	memalloc_noreclaim_restore(noreclaim_flag);
329 
330 	return ret;
331 }
332 EXPORT_SYMBOL(__sk_backlog_rcv);
333 
334 static int sock_get_timeout(long timeo, void *optval, bool old_timeval)
335 {
336 	struct __kernel_sock_timeval tv;
337 
338 	if (timeo == MAX_SCHEDULE_TIMEOUT) {
339 		tv.tv_sec = 0;
340 		tv.tv_usec = 0;
341 	} else {
342 		tv.tv_sec = timeo / HZ;
343 		tv.tv_usec = ((timeo % HZ) * USEC_PER_SEC) / HZ;
344 	}
345 
346 	if (old_timeval && in_compat_syscall() && !COMPAT_USE_64BIT_TIME) {
347 		struct old_timeval32 tv32 = { tv.tv_sec, tv.tv_usec };
348 		*(struct old_timeval32 *)optval = tv32;
349 		return sizeof(tv32);
350 	}
351 
352 	if (old_timeval) {
353 		struct __kernel_old_timeval old_tv;
354 		old_tv.tv_sec = tv.tv_sec;
355 		old_tv.tv_usec = tv.tv_usec;
356 		*(struct __kernel_old_timeval *)optval = old_tv;
357 		return sizeof(old_tv);
358 	}
359 
360 	*(struct __kernel_sock_timeval *)optval = tv;
361 	return sizeof(tv);
362 }
363 
364 static int sock_set_timeout(long *timeo_p, sockptr_t optval, int optlen,
365 			    bool old_timeval)
366 {
367 	struct __kernel_sock_timeval tv;
368 
369 	if (old_timeval && in_compat_syscall() && !COMPAT_USE_64BIT_TIME) {
370 		struct old_timeval32 tv32;
371 
372 		if (optlen < sizeof(tv32))
373 			return -EINVAL;
374 
375 		if (copy_from_sockptr(&tv32, optval, sizeof(tv32)))
376 			return -EFAULT;
377 		tv.tv_sec = tv32.tv_sec;
378 		tv.tv_usec = tv32.tv_usec;
379 	} else if (old_timeval) {
380 		struct __kernel_old_timeval old_tv;
381 
382 		if (optlen < sizeof(old_tv))
383 			return -EINVAL;
384 		if (copy_from_sockptr(&old_tv, optval, sizeof(old_tv)))
385 			return -EFAULT;
386 		tv.tv_sec = old_tv.tv_sec;
387 		tv.tv_usec = old_tv.tv_usec;
388 	} else {
389 		if (optlen < sizeof(tv))
390 			return -EINVAL;
391 		if (copy_from_sockptr(&tv, optval, sizeof(tv)))
392 			return -EFAULT;
393 	}
394 	if (tv.tv_usec < 0 || tv.tv_usec >= USEC_PER_SEC)
395 		return -EDOM;
396 
397 	if (tv.tv_sec < 0) {
398 		static int warned __read_mostly;
399 
400 		*timeo_p = 0;
401 		if (warned < 10 && net_ratelimit()) {
402 			warned++;
403 			pr_info("%s: `%s' (pid %d) tries to set negative timeout\n",
404 				__func__, current->comm, task_pid_nr(current));
405 		}
406 		return 0;
407 	}
408 	*timeo_p = MAX_SCHEDULE_TIMEOUT;
409 	if (tv.tv_sec == 0 && tv.tv_usec == 0)
410 		return 0;
411 	if (tv.tv_sec < (MAX_SCHEDULE_TIMEOUT / HZ - 1))
412 		*timeo_p = tv.tv_sec * HZ + DIV_ROUND_UP((unsigned long)tv.tv_usec, USEC_PER_SEC / HZ);
413 	return 0;
414 }
415 
416 static bool sock_needs_netstamp(const struct sock *sk)
417 {
418 	switch (sk->sk_family) {
419 	case AF_UNSPEC:
420 	case AF_UNIX:
421 		return false;
422 	default:
423 		return true;
424 	}
425 }
426 
427 static void sock_disable_timestamp(struct sock *sk, unsigned long flags)
428 {
429 	if (sk->sk_flags & flags) {
430 		sk->sk_flags &= ~flags;
431 		if (sock_needs_netstamp(sk) &&
432 		    !(sk->sk_flags & SK_FLAGS_TIMESTAMP))
433 			net_disable_timestamp();
434 	}
435 }
436 
437 
438 int __sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
439 {
440 	unsigned long flags;
441 	struct sk_buff_head *list = &sk->sk_receive_queue;
442 
443 	if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf) {
444 		atomic_inc(&sk->sk_drops);
445 		trace_sock_rcvqueue_full(sk, skb);
446 		return -ENOMEM;
447 	}
448 
449 	if (!sk_rmem_schedule(sk, skb, skb->truesize)) {
450 		atomic_inc(&sk->sk_drops);
451 		return -ENOBUFS;
452 	}
453 
454 	skb->dev = NULL;
455 	skb_set_owner_r(skb, sk);
456 
457 	/* we escape from rcu protected region, make sure we dont leak
458 	 * a norefcounted dst
459 	 */
460 	skb_dst_force(skb);
461 
462 	spin_lock_irqsave(&list->lock, flags);
463 	sock_skb_set_dropcount(sk, skb);
464 	__skb_queue_tail(list, skb);
465 	spin_unlock_irqrestore(&list->lock, flags);
466 
467 	if (!sock_flag(sk, SOCK_DEAD))
468 		sk->sk_data_ready(sk);
469 	return 0;
470 }
471 EXPORT_SYMBOL(__sock_queue_rcv_skb);
472 
473 int sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
474 {
475 	int err;
476 
477 	err = sk_filter(sk, skb);
478 	if (err)
479 		return err;
480 
481 	return __sock_queue_rcv_skb(sk, skb);
482 }
483 EXPORT_SYMBOL(sock_queue_rcv_skb);
484 
485 int __sk_receive_skb(struct sock *sk, struct sk_buff *skb,
486 		     const int nested, unsigned int trim_cap, bool refcounted)
487 {
488 	int rc = NET_RX_SUCCESS;
489 
490 	if (sk_filter_trim_cap(sk, skb, trim_cap))
491 		goto discard_and_relse;
492 
493 	skb->dev = NULL;
494 
495 	if (sk_rcvqueues_full(sk, sk->sk_rcvbuf)) {
496 		atomic_inc(&sk->sk_drops);
497 		goto discard_and_relse;
498 	}
499 	if (nested)
500 		bh_lock_sock_nested(sk);
501 	else
502 		bh_lock_sock(sk);
503 	if (!sock_owned_by_user(sk)) {
504 		/*
505 		 * trylock + unlock semantics:
506 		 */
507 		mutex_acquire(&sk->sk_lock.dep_map, 0, 1, _RET_IP_);
508 
509 		rc = sk_backlog_rcv(sk, skb);
510 
511 		mutex_release(&sk->sk_lock.dep_map, _RET_IP_);
512 	} else if (sk_add_backlog(sk, skb, READ_ONCE(sk->sk_rcvbuf))) {
513 		bh_unlock_sock(sk);
514 		atomic_inc(&sk->sk_drops);
515 		goto discard_and_relse;
516 	}
517 
518 	bh_unlock_sock(sk);
519 out:
520 	if (refcounted)
521 		sock_put(sk);
522 	return rc;
523 discard_and_relse:
524 	kfree_skb(skb);
525 	goto out;
526 }
527 EXPORT_SYMBOL(__sk_receive_skb);
528 
529 struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie)
530 {
531 	struct dst_entry *dst = __sk_dst_get(sk);
532 
533 	if (dst && dst->obsolete && dst->ops->check(dst, cookie) == NULL) {
534 		sk_tx_queue_clear(sk);
535 		sk->sk_dst_pending_confirm = 0;
536 		RCU_INIT_POINTER(sk->sk_dst_cache, NULL);
537 		dst_release(dst);
538 		return NULL;
539 	}
540 
541 	return dst;
542 }
543 EXPORT_SYMBOL(__sk_dst_check);
544 
545 struct dst_entry *sk_dst_check(struct sock *sk, u32 cookie)
546 {
547 	struct dst_entry *dst = sk_dst_get(sk);
548 
549 	if (dst && dst->obsolete && dst->ops->check(dst, cookie) == NULL) {
550 		sk_dst_reset(sk);
551 		dst_release(dst);
552 		return NULL;
553 	}
554 
555 	return dst;
556 }
557 EXPORT_SYMBOL(sk_dst_check);
558 
559 static int sock_bindtoindex_locked(struct sock *sk, int ifindex)
560 {
561 	int ret = -ENOPROTOOPT;
562 #ifdef CONFIG_NETDEVICES
563 	struct net *net = sock_net(sk);
564 
565 	/* Sorry... */
566 	ret = -EPERM;
567 	if (sk->sk_bound_dev_if && !ns_capable(net->user_ns, CAP_NET_RAW))
568 		goto out;
569 
570 	ret = -EINVAL;
571 	if (ifindex < 0)
572 		goto out;
573 
574 	sk->sk_bound_dev_if = ifindex;
575 	if (sk->sk_prot->rehash)
576 		sk->sk_prot->rehash(sk);
577 	sk_dst_reset(sk);
578 
579 	ret = 0;
580 
581 out:
582 #endif
583 
584 	return ret;
585 }
586 
587 int sock_bindtoindex(struct sock *sk, int ifindex, bool lock_sk)
588 {
589 	int ret;
590 
591 	if (lock_sk)
592 		lock_sock(sk);
593 	ret = sock_bindtoindex_locked(sk, ifindex);
594 	if (lock_sk)
595 		release_sock(sk);
596 
597 	return ret;
598 }
599 EXPORT_SYMBOL(sock_bindtoindex);
600 
601 static int sock_setbindtodevice(struct sock *sk, sockptr_t optval, int optlen)
602 {
603 	int ret = -ENOPROTOOPT;
604 #ifdef CONFIG_NETDEVICES
605 	struct net *net = sock_net(sk);
606 	char devname[IFNAMSIZ];
607 	int index;
608 
609 	ret = -EINVAL;
610 	if (optlen < 0)
611 		goto out;
612 
613 	/* Bind this socket to a particular device like "eth0",
614 	 * as specified in the passed interface name. If the
615 	 * name is "" or the option length is zero the socket
616 	 * is not bound.
617 	 */
618 	if (optlen > IFNAMSIZ - 1)
619 		optlen = IFNAMSIZ - 1;
620 	memset(devname, 0, sizeof(devname));
621 
622 	ret = -EFAULT;
623 	if (copy_from_sockptr(devname, optval, optlen))
624 		goto out;
625 
626 	index = 0;
627 	if (devname[0] != '\0') {
628 		struct net_device *dev;
629 
630 		rcu_read_lock();
631 		dev = dev_get_by_name_rcu(net, devname);
632 		if (dev)
633 			index = dev->ifindex;
634 		rcu_read_unlock();
635 		ret = -ENODEV;
636 		if (!dev)
637 			goto out;
638 	}
639 
640 	return sock_bindtoindex(sk, index, true);
641 out:
642 #endif
643 
644 	return ret;
645 }
646 
647 static int sock_getbindtodevice(struct sock *sk, char __user *optval,
648 				int __user *optlen, int len)
649 {
650 	int ret = -ENOPROTOOPT;
651 #ifdef CONFIG_NETDEVICES
652 	struct net *net = sock_net(sk);
653 	char devname[IFNAMSIZ];
654 
655 	if (sk->sk_bound_dev_if == 0) {
656 		len = 0;
657 		goto zero;
658 	}
659 
660 	ret = -EINVAL;
661 	if (len < IFNAMSIZ)
662 		goto out;
663 
664 	ret = netdev_get_name(net, devname, sk->sk_bound_dev_if);
665 	if (ret)
666 		goto out;
667 
668 	len = strlen(devname) + 1;
669 
670 	ret = -EFAULT;
671 	if (copy_to_user(optval, devname, len))
672 		goto out;
673 
674 zero:
675 	ret = -EFAULT;
676 	if (put_user(len, optlen))
677 		goto out;
678 
679 	ret = 0;
680 
681 out:
682 #endif
683 
684 	return ret;
685 }
686 
687 bool sk_mc_loop(struct sock *sk)
688 {
689 	if (dev_recursion_level())
690 		return false;
691 	if (!sk)
692 		return true;
693 	switch (sk->sk_family) {
694 	case AF_INET:
695 		return inet_sk(sk)->mc_loop;
696 #if IS_ENABLED(CONFIG_IPV6)
697 	case AF_INET6:
698 		return inet6_sk(sk)->mc_loop;
699 #endif
700 	}
701 	WARN_ON_ONCE(1);
702 	return true;
703 }
704 EXPORT_SYMBOL(sk_mc_loop);
705 
706 void sock_set_reuseaddr(struct sock *sk)
707 {
708 	lock_sock(sk);
709 	sk->sk_reuse = SK_CAN_REUSE;
710 	release_sock(sk);
711 }
712 EXPORT_SYMBOL(sock_set_reuseaddr);
713 
714 void sock_set_reuseport(struct sock *sk)
715 {
716 	lock_sock(sk);
717 	sk->sk_reuseport = true;
718 	release_sock(sk);
719 }
720 EXPORT_SYMBOL(sock_set_reuseport);
721 
722 void sock_no_linger(struct sock *sk)
723 {
724 	lock_sock(sk);
725 	sk->sk_lingertime = 0;
726 	sock_set_flag(sk, SOCK_LINGER);
727 	release_sock(sk);
728 }
729 EXPORT_SYMBOL(sock_no_linger);
730 
731 void sock_set_priority(struct sock *sk, u32 priority)
732 {
733 	lock_sock(sk);
734 	sk->sk_priority = priority;
735 	release_sock(sk);
736 }
737 EXPORT_SYMBOL(sock_set_priority);
738 
739 void sock_set_sndtimeo(struct sock *sk, s64 secs)
740 {
741 	lock_sock(sk);
742 	if (secs && secs < MAX_SCHEDULE_TIMEOUT / HZ - 1)
743 		sk->sk_sndtimeo = secs * HZ;
744 	else
745 		sk->sk_sndtimeo = MAX_SCHEDULE_TIMEOUT;
746 	release_sock(sk);
747 }
748 EXPORT_SYMBOL(sock_set_sndtimeo);
749 
750 static void __sock_set_timestamps(struct sock *sk, bool val, bool new, bool ns)
751 {
752 	if (val)  {
753 		sock_valbool_flag(sk, SOCK_TSTAMP_NEW, new);
754 		sock_valbool_flag(sk, SOCK_RCVTSTAMPNS, ns);
755 		sock_set_flag(sk, SOCK_RCVTSTAMP);
756 		sock_enable_timestamp(sk, SOCK_TIMESTAMP);
757 	} else {
758 		sock_reset_flag(sk, SOCK_RCVTSTAMP);
759 		sock_reset_flag(sk, SOCK_RCVTSTAMPNS);
760 	}
761 }
762 
763 void sock_enable_timestamps(struct sock *sk)
764 {
765 	lock_sock(sk);
766 	__sock_set_timestamps(sk, true, false, true);
767 	release_sock(sk);
768 }
769 EXPORT_SYMBOL(sock_enable_timestamps);
770 
771 void sock_set_keepalive(struct sock *sk)
772 {
773 	lock_sock(sk);
774 	if (sk->sk_prot->keepalive)
775 		sk->sk_prot->keepalive(sk, true);
776 	sock_valbool_flag(sk, SOCK_KEEPOPEN, true);
777 	release_sock(sk);
778 }
779 EXPORT_SYMBOL(sock_set_keepalive);
780 
781 static void __sock_set_rcvbuf(struct sock *sk, int val)
782 {
783 	/* Ensure val * 2 fits into an int, to prevent max_t() from treating it
784 	 * as a negative value.
785 	 */
786 	val = min_t(int, val, INT_MAX / 2);
787 	sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
788 
789 	/* We double it on the way in to account for "struct sk_buff" etc.
790 	 * overhead.   Applications assume that the SO_RCVBUF setting they make
791 	 * will allow that much actual data to be received on that socket.
792 	 *
793 	 * Applications are unaware that "struct sk_buff" and other overheads
794 	 * allocate from the receive buffer during socket buffer allocation.
795 	 *
796 	 * And after considering the possible alternatives, returning the value
797 	 * we actually used in getsockopt is the most desirable behavior.
798 	 */
799 	WRITE_ONCE(sk->sk_rcvbuf, max_t(int, val * 2, SOCK_MIN_RCVBUF));
800 }
801 
802 void sock_set_rcvbuf(struct sock *sk, int val)
803 {
804 	lock_sock(sk);
805 	__sock_set_rcvbuf(sk, val);
806 	release_sock(sk);
807 }
808 EXPORT_SYMBOL(sock_set_rcvbuf);
809 
810 void sock_set_mark(struct sock *sk, u32 val)
811 {
812 	lock_sock(sk);
813 	sk->sk_mark = val;
814 	release_sock(sk);
815 }
816 EXPORT_SYMBOL(sock_set_mark);
817 
818 /*
819  *	This is meant for all protocols to use and covers goings on
820  *	at the socket level. Everything here is generic.
821  */
822 
823 int sock_setsockopt(struct socket *sock, int level, int optname,
824 		    sockptr_t optval, unsigned int optlen)
825 {
826 	struct sock_txtime sk_txtime;
827 	struct sock *sk = sock->sk;
828 	int val;
829 	int valbool;
830 	struct linger ling;
831 	int ret = 0;
832 
833 	/*
834 	 *	Options without arguments
835 	 */
836 
837 	if (optname == SO_BINDTODEVICE)
838 		return sock_setbindtodevice(sk, optval, optlen);
839 
840 	if (optlen < sizeof(int))
841 		return -EINVAL;
842 
843 	if (copy_from_sockptr(&val, optval, sizeof(val)))
844 		return -EFAULT;
845 
846 	valbool = val ? 1 : 0;
847 
848 	lock_sock(sk);
849 
850 	switch (optname) {
851 	case SO_DEBUG:
852 		if (val && !capable(CAP_NET_ADMIN))
853 			ret = -EACCES;
854 		else
855 			sock_valbool_flag(sk, SOCK_DBG, valbool);
856 		break;
857 	case SO_REUSEADDR:
858 		sk->sk_reuse = (valbool ? SK_CAN_REUSE : SK_NO_REUSE);
859 		break;
860 	case SO_REUSEPORT:
861 		sk->sk_reuseport = valbool;
862 		break;
863 	case SO_TYPE:
864 	case SO_PROTOCOL:
865 	case SO_DOMAIN:
866 	case SO_ERROR:
867 		ret = -ENOPROTOOPT;
868 		break;
869 	case SO_DONTROUTE:
870 		sock_valbool_flag(sk, SOCK_LOCALROUTE, valbool);
871 		sk_dst_reset(sk);
872 		break;
873 	case SO_BROADCAST:
874 		sock_valbool_flag(sk, SOCK_BROADCAST, valbool);
875 		break;
876 	case SO_SNDBUF:
877 		/* Don't error on this BSD doesn't and if you think
878 		 * about it this is right. Otherwise apps have to
879 		 * play 'guess the biggest size' games. RCVBUF/SNDBUF
880 		 * are treated in BSD as hints
881 		 */
882 		val = min_t(u32, val, sysctl_wmem_max);
883 set_sndbuf:
884 		/* Ensure val * 2 fits into an int, to prevent max_t()
885 		 * from treating it as a negative value.
886 		 */
887 		val = min_t(int, val, INT_MAX / 2);
888 		sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
889 		WRITE_ONCE(sk->sk_sndbuf,
890 			   max_t(int, val * 2, SOCK_MIN_SNDBUF));
891 		/* Wake up sending tasks if we upped the value. */
892 		sk->sk_write_space(sk);
893 		break;
894 
895 	case SO_SNDBUFFORCE:
896 		if (!capable(CAP_NET_ADMIN)) {
897 			ret = -EPERM;
898 			break;
899 		}
900 
901 		/* No negative values (to prevent underflow, as val will be
902 		 * multiplied by 2).
903 		 */
904 		if (val < 0)
905 			val = 0;
906 		goto set_sndbuf;
907 
908 	case SO_RCVBUF:
909 		/* Don't error on this BSD doesn't and if you think
910 		 * about it this is right. Otherwise apps have to
911 		 * play 'guess the biggest size' games. RCVBUF/SNDBUF
912 		 * are treated in BSD as hints
913 		 */
914 		__sock_set_rcvbuf(sk, min_t(u32, val, sysctl_rmem_max));
915 		break;
916 
917 	case SO_RCVBUFFORCE:
918 		if (!capable(CAP_NET_ADMIN)) {
919 			ret = -EPERM;
920 			break;
921 		}
922 
923 		/* No negative values (to prevent underflow, as val will be
924 		 * multiplied by 2).
925 		 */
926 		__sock_set_rcvbuf(sk, max(val, 0));
927 		break;
928 
929 	case SO_KEEPALIVE:
930 		if (sk->sk_prot->keepalive)
931 			sk->sk_prot->keepalive(sk, valbool);
932 		sock_valbool_flag(sk, SOCK_KEEPOPEN, valbool);
933 		break;
934 
935 	case SO_OOBINLINE:
936 		sock_valbool_flag(sk, SOCK_URGINLINE, valbool);
937 		break;
938 
939 	case SO_NO_CHECK:
940 		sk->sk_no_check_tx = valbool;
941 		break;
942 
943 	case SO_PRIORITY:
944 		if ((val >= 0 && val <= 6) ||
945 		    ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
946 			sk->sk_priority = val;
947 		else
948 			ret = -EPERM;
949 		break;
950 
951 	case SO_LINGER:
952 		if (optlen < sizeof(ling)) {
953 			ret = -EINVAL;	/* 1003.1g */
954 			break;
955 		}
956 		if (copy_from_sockptr(&ling, optval, sizeof(ling))) {
957 			ret = -EFAULT;
958 			break;
959 		}
960 		if (!ling.l_onoff)
961 			sock_reset_flag(sk, SOCK_LINGER);
962 		else {
963 #if (BITS_PER_LONG == 32)
964 			if ((unsigned int)ling.l_linger >= MAX_SCHEDULE_TIMEOUT/HZ)
965 				sk->sk_lingertime = MAX_SCHEDULE_TIMEOUT;
966 			else
967 #endif
968 				sk->sk_lingertime = (unsigned int)ling.l_linger * HZ;
969 			sock_set_flag(sk, SOCK_LINGER);
970 		}
971 		break;
972 
973 	case SO_BSDCOMPAT:
974 		break;
975 
976 	case SO_PASSCRED:
977 		if (valbool)
978 			set_bit(SOCK_PASSCRED, &sock->flags);
979 		else
980 			clear_bit(SOCK_PASSCRED, &sock->flags);
981 		break;
982 
983 	case SO_TIMESTAMP_OLD:
984 		__sock_set_timestamps(sk, valbool, false, false);
985 		break;
986 	case SO_TIMESTAMP_NEW:
987 		__sock_set_timestamps(sk, valbool, true, false);
988 		break;
989 	case SO_TIMESTAMPNS_OLD:
990 		__sock_set_timestamps(sk, valbool, false, true);
991 		break;
992 	case SO_TIMESTAMPNS_NEW:
993 		__sock_set_timestamps(sk, valbool, true, true);
994 		break;
995 	case SO_TIMESTAMPING_NEW:
996 	case SO_TIMESTAMPING_OLD:
997 		if (val & ~SOF_TIMESTAMPING_MASK) {
998 			ret = -EINVAL;
999 			break;
1000 		}
1001 
1002 		if (val & SOF_TIMESTAMPING_OPT_ID &&
1003 		    !(sk->sk_tsflags & SOF_TIMESTAMPING_OPT_ID)) {
1004 			if (sk->sk_protocol == IPPROTO_TCP &&
1005 			    sk->sk_type == SOCK_STREAM) {
1006 				if ((1 << sk->sk_state) &
1007 				    (TCPF_CLOSE | TCPF_LISTEN)) {
1008 					ret = -EINVAL;
1009 					break;
1010 				}
1011 				sk->sk_tskey = tcp_sk(sk)->snd_una;
1012 			} else {
1013 				sk->sk_tskey = 0;
1014 			}
1015 		}
1016 
1017 		if (val & SOF_TIMESTAMPING_OPT_STATS &&
1018 		    !(val & SOF_TIMESTAMPING_OPT_TSONLY)) {
1019 			ret = -EINVAL;
1020 			break;
1021 		}
1022 
1023 		sk->sk_tsflags = val;
1024 		sock_valbool_flag(sk, SOCK_TSTAMP_NEW, optname == SO_TIMESTAMPING_NEW);
1025 
1026 		if (val & SOF_TIMESTAMPING_RX_SOFTWARE)
1027 			sock_enable_timestamp(sk,
1028 					      SOCK_TIMESTAMPING_RX_SOFTWARE);
1029 		else
1030 			sock_disable_timestamp(sk,
1031 					       (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE));
1032 		break;
1033 
1034 	case SO_RCVLOWAT:
1035 		if (val < 0)
1036 			val = INT_MAX;
1037 		if (sock->ops->set_rcvlowat)
1038 			ret = sock->ops->set_rcvlowat(sk, val);
1039 		else
1040 			WRITE_ONCE(sk->sk_rcvlowat, val ? : 1);
1041 		break;
1042 
1043 	case SO_RCVTIMEO_OLD:
1044 	case SO_RCVTIMEO_NEW:
1045 		ret = sock_set_timeout(&sk->sk_rcvtimeo, optval,
1046 				       optlen, optname == SO_RCVTIMEO_OLD);
1047 		break;
1048 
1049 	case SO_SNDTIMEO_OLD:
1050 	case SO_SNDTIMEO_NEW:
1051 		ret = sock_set_timeout(&sk->sk_sndtimeo, optval,
1052 				       optlen, optname == SO_SNDTIMEO_OLD);
1053 		break;
1054 
1055 	case SO_ATTACH_FILTER: {
1056 		struct sock_fprog fprog;
1057 
1058 		ret = copy_bpf_fprog_from_user(&fprog, optval, optlen);
1059 		if (!ret)
1060 			ret = sk_attach_filter(&fprog, sk);
1061 		break;
1062 	}
1063 	case SO_ATTACH_BPF:
1064 		ret = -EINVAL;
1065 		if (optlen == sizeof(u32)) {
1066 			u32 ufd;
1067 
1068 			ret = -EFAULT;
1069 			if (copy_from_sockptr(&ufd, optval, sizeof(ufd)))
1070 				break;
1071 
1072 			ret = sk_attach_bpf(ufd, sk);
1073 		}
1074 		break;
1075 
1076 	case SO_ATTACH_REUSEPORT_CBPF: {
1077 		struct sock_fprog fprog;
1078 
1079 		ret = copy_bpf_fprog_from_user(&fprog, optval, optlen);
1080 		if (!ret)
1081 			ret = sk_reuseport_attach_filter(&fprog, sk);
1082 		break;
1083 	}
1084 	case SO_ATTACH_REUSEPORT_EBPF:
1085 		ret = -EINVAL;
1086 		if (optlen == sizeof(u32)) {
1087 			u32 ufd;
1088 
1089 			ret = -EFAULT;
1090 			if (copy_from_sockptr(&ufd, optval, sizeof(ufd)))
1091 				break;
1092 
1093 			ret = sk_reuseport_attach_bpf(ufd, sk);
1094 		}
1095 		break;
1096 
1097 	case SO_DETACH_REUSEPORT_BPF:
1098 		ret = reuseport_detach_prog(sk);
1099 		break;
1100 
1101 	case SO_DETACH_FILTER:
1102 		ret = sk_detach_filter(sk);
1103 		break;
1104 
1105 	case SO_LOCK_FILTER:
1106 		if (sock_flag(sk, SOCK_FILTER_LOCKED) && !valbool)
1107 			ret = -EPERM;
1108 		else
1109 			sock_valbool_flag(sk, SOCK_FILTER_LOCKED, valbool);
1110 		break;
1111 
1112 	case SO_PASSSEC:
1113 		if (valbool)
1114 			set_bit(SOCK_PASSSEC, &sock->flags);
1115 		else
1116 			clear_bit(SOCK_PASSSEC, &sock->flags);
1117 		break;
1118 	case SO_MARK:
1119 		if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) {
1120 			ret = -EPERM;
1121 		} else if (val != sk->sk_mark) {
1122 			sk->sk_mark = val;
1123 			sk_dst_reset(sk);
1124 		}
1125 		break;
1126 
1127 	case SO_RXQ_OVFL:
1128 		sock_valbool_flag(sk, SOCK_RXQ_OVFL, valbool);
1129 		break;
1130 
1131 	case SO_WIFI_STATUS:
1132 		sock_valbool_flag(sk, SOCK_WIFI_STATUS, valbool);
1133 		break;
1134 
1135 	case SO_PEEK_OFF:
1136 		if (sock->ops->set_peek_off)
1137 			ret = sock->ops->set_peek_off(sk, val);
1138 		else
1139 			ret = -EOPNOTSUPP;
1140 		break;
1141 
1142 	case SO_NOFCS:
1143 		sock_valbool_flag(sk, SOCK_NOFCS, valbool);
1144 		break;
1145 
1146 	case SO_SELECT_ERR_QUEUE:
1147 		sock_valbool_flag(sk, SOCK_SELECT_ERR_QUEUE, valbool);
1148 		break;
1149 
1150 #ifdef CONFIG_NET_RX_BUSY_POLL
1151 	case SO_BUSY_POLL:
1152 		/* allow unprivileged users to decrease the value */
1153 		if ((val > sk->sk_ll_usec) && !capable(CAP_NET_ADMIN))
1154 			ret = -EPERM;
1155 		else {
1156 			if (val < 0)
1157 				ret = -EINVAL;
1158 			else
1159 				sk->sk_ll_usec = val;
1160 		}
1161 		break;
1162 	case SO_PREFER_BUSY_POLL:
1163 		if (valbool && !capable(CAP_NET_ADMIN))
1164 			ret = -EPERM;
1165 		else
1166 			WRITE_ONCE(sk->sk_prefer_busy_poll, valbool);
1167 		break;
1168 	case SO_BUSY_POLL_BUDGET:
1169 		if (val > READ_ONCE(sk->sk_busy_poll_budget) && !capable(CAP_NET_ADMIN)) {
1170 			ret = -EPERM;
1171 		} else {
1172 			if (val < 0 || val > U16_MAX)
1173 				ret = -EINVAL;
1174 			else
1175 				WRITE_ONCE(sk->sk_busy_poll_budget, val);
1176 		}
1177 		break;
1178 #endif
1179 
1180 	case SO_MAX_PACING_RATE:
1181 		{
1182 		unsigned long ulval = (val == ~0U) ? ~0UL : (unsigned int)val;
1183 
1184 		if (sizeof(ulval) != sizeof(val) &&
1185 		    optlen >= sizeof(ulval) &&
1186 		    copy_from_sockptr(&ulval, optval, sizeof(ulval))) {
1187 			ret = -EFAULT;
1188 			break;
1189 		}
1190 		if (ulval != ~0UL)
1191 			cmpxchg(&sk->sk_pacing_status,
1192 				SK_PACING_NONE,
1193 				SK_PACING_NEEDED);
1194 		sk->sk_max_pacing_rate = ulval;
1195 		sk->sk_pacing_rate = min(sk->sk_pacing_rate, ulval);
1196 		break;
1197 		}
1198 	case SO_INCOMING_CPU:
1199 		WRITE_ONCE(sk->sk_incoming_cpu, val);
1200 		break;
1201 
1202 	case SO_CNX_ADVICE:
1203 		if (val == 1)
1204 			dst_negative_advice(sk);
1205 		break;
1206 
1207 	case SO_ZEROCOPY:
1208 		if (sk->sk_family == PF_INET || sk->sk_family == PF_INET6) {
1209 			if (!((sk->sk_type == SOCK_STREAM &&
1210 			       sk->sk_protocol == IPPROTO_TCP) ||
1211 			      (sk->sk_type == SOCK_DGRAM &&
1212 			       sk->sk_protocol == IPPROTO_UDP)))
1213 				ret = -ENOTSUPP;
1214 		} else if (sk->sk_family != PF_RDS) {
1215 			ret = -ENOTSUPP;
1216 		}
1217 		if (!ret) {
1218 			if (val < 0 || val > 1)
1219 				ret = -EINVAL;
1220 			else
1221 				sock_valbool_flag(sk, SOCK_ZEROCOPY, valbool);
1222 		}
1223 		break;
1224 
1225 	case SO_TXTIME:
1226 		if (optlen != sizeof(struct sock_txtime)) {
1227 			ret = -EINVAL;
1228 			break;
1229 		} else if (copy_from_sockptr(&sk_txtime, optval,
1230 			   sizeof(struct sock_txtime))) {
1231 			ret = -EFAULT;
1232 			break;
1233 		} else if (sk_txtime.flags & ~SOF_TXTIME_FLAGS_MASK) {
1234 			ret = -EINVAL;
1235 			break;
1236 		}
1237 		/* CLOCK_MONOTONIC is only used by sch_fq, and this packet
1238 		 * scheduler has enough safe guards.
1239 		 */
1240 		if (sk_txtime.clockid != CLOCK_MONOTONIC &&
1241 		    !ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) {
1242 			ret = -EPERM;
1243 			break;
1244 		}
1245 		sock_valbool_flag(sk, SOCK_TXTIME, true);
1246 		sk->sk_clockid = sk_txtime.clockid;
1247 		sk->sk_txtime_deadline_mode =
1248 			!!(sk_txtime.flags & SOF_TXTIME_DEADLINE_MODE);
1249 		sk->sk_txtime_report_errors =
1250 			!!(sk_txtime.flags & SOF_TXTIME_REPORT_ERRORS);
1251 		break;
1252 
1253 	case SO_BINDTOIFINDEX:
1254 		ret = sock_bindtoindex_locked(sk, val);
1255 		break;
1256 
1257 	default:
1258 		ret = -ENOPROTOOPT;
1259 		break;
1260 	}
1261 	release_sock(sk);
1262 	return ret;
1263 }
1264 EXPORT_SYMBOL(sock_setsockopt);
1265 
1266 
1267 static void cred_to_ucred(struct pid *pid, const struct cred *cred,
1268 			  struct ucred *ucred)
1269 {
1270 	ucred->pid = pid_vnr(pid);
1271 	ucred->uid = ucred->gid = -1;
1272 	if (cred) {
1273 		struct user_namespace *current_ns = current_user_ns();
1274 
1275 		ucred->uid = from_kuid_munged(current_ns, cred->euid);
1276 		ucred->gid = from_kgid_munged(current_ns, cred->egid);
1277 	}
1278 }
1279 
1280 static int groups_to_user(gid_t __user *dst, const struct group_info *src)
1281 {
1282 	struct user_namespace *user_ns = current_user_ns();
1283 	int i;
1284 
1285 	for (i = 0; i < src->ngroups; i++)
1286 		if (put_user(from_kgid_munged(user_ns, src->gid[i]), dst + i))
1287 			return -EFAULT;
1288 
1289 	return 0;
1290 }
1291 
1292 int sock_getsockopt(struct socket *sock, int level, int optname,
1293 		    char __user *optval, int __user *optlen)
1294 {
1295 	struct sock *sk = sock->sk;
1296 
1297 	union {
1298 		int val;
1299 		u64 val64;
1300 		unsigned long ulval;
1301 		struct linger ling;
1302 		struct old_timeval32 tm32;
1303 		struct __kernel_old_timeval tm;
1304 		struct  __kernel_sock_timeval stm;
1305 		struct sock_txtime txtime;
1306 	} v;
1307 
1308 	int lv = sizeof(int);
1309 	int len;
1310 
1311 	if (get_user(len, optlen))
1312 		return -EFAULT;
1313 	if (len < 0)
1314 		return -EINVAL;
1315 
1316 	memset(&v, 0, sizeof(v));
1317 
1318 	switch (optname) {
1319 	case SO_DEBUG:
1320 		v.val = sock_flag(sk, SOCK_DBG);
1321 		break;
1322 
1323 	case SO_DONTROUTE:
1324 		v.val = sock_flag(sk, SOCK_LOCALROUTE);
1325 		break;
1326 
1327 	case SO_BROADCAST:
1328 		v.val = sock_flag(sk, SOCK_BROADCAST);
1329 		break;
1330 
1331 	case SO_SNDBUF:
1332 		v.val = sk->sk_sndbuf;
1333 		break;
1334 
1335 	case SO_RCVBUF:
1336 		v.val = sk->sk_rcvbuf;
1337 		break;
1338 
1339 	case SO_REUSEADDR:
1340 		v.val = sk->sk_reuse;
1341 		break;
1342 
1343 	case SO_REUSEPORT:
1344 		v.val = sk->sk_reuseport;
1345 		break;
1346 
1347 	case SO_KEEPALIVE:
1348 		v.val = sock_flag(sk, SOCK_KEEPOPEN);
1349 		break;
1350 
1351 	case SO_TYPE:
1352 		v.val = sk->sk_type;
1353 		break;
1354 
1355 	case SO_PROTOCOL:
1356 		v.val = sk->sk_protocol;
1357 		break;
1358 
1359 	case SO_DOMAIN:
1360 		v.val = sk->sk_family;
1361 		break;
1362 
1363 	case SO_ERROR:
1364 		v.val = -sock_error(sk);
1365 		if (v.val == 0)
1366 			v.val = xchg(&sk->sk_err_soft, 0);
1367 		break;
1368 
1369 	case SO_OOBINLINE:
1370 		v.val = sock_flag(sk, SOCK_URGINLINE);
1371 		break;
1372 
1373 	case SO_NO_CHECK:
1374 		v.val = sk->sk_no_check_tx;
1375 		break;
1376 
1377 	case SO_PRIORITY:
1378 		v.val = sk->sk_priority;
1379 		break;
1380 
1381 	case SO_LINGER:
1382 		lv		= sizeof(v.ling);
1383 		v.ling.l_onoff	= sock_flag(sk, SOCK_LINGER);
1384 		v.ling.l_linger	= sk->sk_lingertime / HZ;
1385 		break;
1386 
1387 	case SO_BSDCOMPAT:
1388 		break;
1389 
1390 	case SO_TIMESTAMP_OLD:
1391 		v.val = sock_flag(sk, SOCK_RCVTSTAMP) &&
1392 				!sock_flag(sk, SOCK_TSTAMP_NEW) &&
1393 				!sock_flag(sk, SOCK_RCVTSTAMPNS);
1394 		break;
1395 
1396 	case SO_TIMESTAMPNS_OLD:
1397 		v.val = sock_flag(sk, SOCK_RCVTSTAMPNS) && !sock_flag(sk, SOCK_TSTAMP_NEW);
1398 		break;
1399 
1400 	case SO_TIMESTAMP_NEW:
1401 		v.val = sock_flag(sk, SOCK_RCVTSTAMP) && sock_flag(sk, SOCK_TSTAMP_NEW);
1402 		break;
1403 
1404 	case SO_TIMESTAMPNS_NEW:
1405 		v.val = sock_flag(sk, SOCK_RCVTSTAMPNS) && sock_flag(sk, SOCK_TSTAMP_NEW);
1406 		break;
1407 
1408 	case SO_TIMESTAMPING_OLD:
1409 		v.val = sk->sk_tsflags;
1410 		break;
1411 
1412 	case SO_RCVTIMEO_OLD:
1413 	case SO_RCVTIMEO_NEW:
1414 		lv = sock_get_timeout(sk->sk_rcvtimeo, &v, SO_RCVTIMEO_OLD == optname);
1415 		break;
1416 
1417 	case SO_SNDTIMEO_OLD:
1418 	case SO_SNDTIMEO_NEW:
1419 		lv = sock_get_timeout(sk->sk_sndtimeo, &v, SO_SNDTIMEO_OLD == optname);
1420 		break;
1421 
1422 	case SO_RCVLOWAT:
1423 		v.val = sk->sk_rcvlowat;
1424 		break;
1425 
1426 	case SO_SNDLOWAT:
1427 		v.val = 1;
1428 		break;
1429 
1430 	case SO_PASSCRED:
1431 		v.val = !!test_bit(SOCK_PASSCRED, &sock->flags);
1432 		break;
1433 
1434 	case SO_PEERCRED:
1435 	{
1436 		struct ucred peercred;
1437 		if (len > sizeof(peercred))
1438 			len = sizeof(peercred);
1439 		cred_to_ucred(sk->sk_peer_pid, sk->sk_peer_cred, &peercred);
1440 		if (copy_to_user(optval, &peercred, len))
1441 			return -EFAULT;
1442 		goto lenout;
1443 	}
1444 
1445 	case SO_PEERGROUPS:
1446 	{
1447 		int ret, n;
1448 
1449 		if (!sk->sk_peer_cred)
1450 			return -ENODATA;
1451 
1452 		n = sk->sk_peer_cred->group_info->ngroups;
1453 		if (len < n * sizeof(gid_t)) {
1454 			len = n * sizeof(gid_t);
1455 			return put_user(len, optlen) ? -EFAULT : -ERANGE;
1456 		}
1457 		len = n * sizeof(gid_t);
1458 
1459 		ret = groups_to_user((gid_t __user *)optval,
1460 				     sk->sk_peer_cred->group_info);
1461 		if (ret)
1462 			return ret;
1463 		goto lenout;
1464 	}
1465 
1466 	case SO_PEERNAME:
1467 	{
1468 		char address[128];
1469 
1470 		lv = sock->ops->getname(sock, (struct sockaddr *)address, 2);
1471 		if (lv < 0)
1472 			return -ENOTCONN;
1473 		if (lv < len)
1474 			return -EINVAL;
1475 		if (copy_to_user(optval, address, len))
1476 			return -EFAULT;
1477 		goto lenout;
1478 	}
1479 
1480 	/* Dubious BSD thing... Probably nobody even uses it, but
1481 	 * the UNIX standard wants it for whatever reason... -DaveM
1482 	 */
1483 	case SO_ACCEPTCONN:
1484 		v.val = sk->sk_state == TCP_LISTEN;
1485 		break;
1486 
1487 	case SO_PASSSEC:
1488 		v.val = !!test_bit(SOCK_PASSSEC, &sock->flags);
1489 		break;
1490 
1491 	case SO_PEERSEC:
1492 		return security_socket_getpeersec_stream(sock, optval, optlen, len);
1493 
1494 	case SO_MARK:
1495 		v.val = sk->sk_mark;
1496 		break;
1497 
1498 	case SO_RXQ_OVFL:
1499 		v.val = sock_flag(sk, SOCK_RXQ_OVFL);
1500 		break;
1501 
1502 	case SO_WIFI_STATUS:
1503 		v.val = sock_flag(sk, SOCK_WIFI_STATUS);
1504 		break;
1505 
1506 	case SO_PEEK_OFF:
1507 		if (!sock->ops->set_peek_off)
1508 			return -EOPNOTSUPP;
1509 
1510 		v.val = sk->sk_peek_off;
1511 		break;
1512 	case SO_NOFCS:
1513 		v.val = sock_flag(sk, SOCK_NOFCS);
1514 		break;
1515 
1516 	case SO_BINDTODEVICE:
1517 		return sock_getbindtodevice(sk, optval, optlen, len);
1518 
1519 	case SO_GET_FILTER:
1520 		len = sk_get_filter(sk, (struct sock_filter __user *)optval, len);
1521 		if (len < 0)
1522 			return len;
1523 
1524 		goto lenout;
1525 
1526 	case SO_LOCK_FILTER:
1527 		v.val = sock_flag(sk, SOCK_FILTER_LOCKED);
1528 		break;
1529 
1530 	case SO_BPF_EXTENSIONS:
1531 		v.val = bpf_tell_extensions();
1532 		break;
1533 
1534 	case SO_SELECT_ERR_QUEUE:
1535 		v.val = sock_flag(sk, SOCK_SELECT_ERR_QUEUE);
1536 		break;
1537 
1538 #ifdef CONFIG_NET_RX_BUSY_POLL
1539 	case SO_BUSY_POLL:
1540 		v.val = sk->sk_ll_usec;
1541 		break;
1542 	case SO_PREFER_BUSY_POLL:
1543 		v.val = READ_ONCE(sk->sk_prefer_busy_poll);
1544 		break;
1545 #endif
1546 
1547 	case SO_MAX_PACING_RATE:
1548 		if (sizeof(v.ulval) != sizeof(v.val) && len >= sizeof(v.ulval)) {
1549 			lv = sizeof(v.ulval);
1550 			v.ulval = sk->sk_max_pacing_rate;
1551 		} else {
1552 			/* 32bit version */
1553 			v.val = min_t(unsigned long, sk->sk_max_pacing_rate, ~0U);
1554 		}
1555 		break;
1556 
1557 	case SO_INCOMING_CPU:
1558 		v.val = READ_ONCE(sk->sk_incoming_cpu);
1559 		break;
1560 
1561 	case SO_MEMINFO:
1562 	{
1563 		u32 meminfo[SK_MEMINFO_VARS];
1564 
1565 		sk_get_meminfo(sk, meminfo);
1566 
1567 		len = min_t(unsigned int, len, sizeof(meminfo));
1568 		if (copy_to_user(optval, &meminfo, len))
1569 			return -EFAULT;
1570 
1571 		goto lenout;
1572 	}
1573 
1574 #ifdef CONFIG_NET_RX_BUSY_POLL
1575 	case SO_INCOMING_NAPI_ID:
1576 		v.val = READ_ONCE(sk->sk_napi_id);
1577 
1578 		/* aggregate non-NAPI IDs down to 0 */
1579 		if (v.val < MIN_NAPI_ID)
1580 			v.val = 0;
1581 
1582 		break;
1583 #endif
1584 
1585 	case SO_COOKIE:
1586 		lv = sizeof(u64);
1587 		if (len < lv)
1588 			return -EINVAL;
1589 		v.val64 = sock_gen_cookie(sk);
1590 		break;
1591 
1592 	case SO_ZEROCOPY:
1593 		v.val = sock_flag(sk, SOCK_ZEROCOPY);
1594 		break;
1595 
1596 	case SO_TXTIME:
1597 		lv = sizeof(v.txtime);
1598 		v.txtime.clockid = sk->sk_clockid;
1599 		v.txtime.flags |= sk->sk_txtime_deadline_mode ?
1600 				  SOF_TXTIME_DEADLINE_MODE : 0;
1601 		v.txtime.flags |= sk->sk_txtime_report_errors ?
1602 				  SOF_TXTIME_REPORT_ERRORS : 0;
1603 		break;
1604 
1605 	case SO_BINDTOIFINDEX:
1606 		v.val = sk->sk_bound_dev_if;
1607 		break;
1608 
1609 	default:
1610 		/* We implement the SO_SNDLOWAT etc to not be settable
1611 		 * (1003.1g 7).
1612 		 */
1613 		return -ENOPROTOOPT;
1614 	}
1615 
1616 	if (len > lv)
1617 		len = lv;
1618 	if (copy_to_user(optval, &v, len))
1619 		return -EFAULT;
1620 lenout:
1621 	if (put_user(len, optlen))
1622 		return -EFAULT;
1623 	return 0;
1624 }
1625 
1626 /*
1627  * Initialize an sk_lock.
1628  *
1629  * (We also register the sk_lock with the lock validator.)
1630  */
1631 static inline void sock_lock_init(struct sock *sk)
1632 {
1633 	if (sk->sk_kern_sock)
1634 		sock_lock_init_class_and_name(
1635 			sk,
1636 			af_family_kern_slock_key_strings[sk->sk_family],
1637 			af_family_kern_slock_keys + sk->sk_family,
1638 			af_family_kern_key_strings[sk->sk_family],
1639 			af_family_kern_keys + sk->sk_family);
1640 	else
1641 		sock_lock_init_class_and_name(
1642 			sk,
1643 			af_family_slock_key_strings[sk->sk_family],
1644 			af_family_slock_keys + sk->sk_family,
1645 			af_family_key_strings[sk->sk_family],
1646 			af_family_keys + sk->sk_family);
1647 }
1648 
1649 /*
1650  * Copy all fields from osk to nsk but nsk->sk_refcnt must not change yet,
1651  * even temporarly, because of RCU lookups. sk_node should also be left as is.
1652  * We must not copy fields between sk_dontcopy_begin and sk_dontcopy_end
1653  */
1654 static void sock_copy(struct sock *nsk, const struct sock *osk)
1655 {
1656 	const struct proto *prot = READ_ONCE(osk->sk_prot);
1657 #ifdef CONFIG_SECURITY_NETWORK
1658 	void *sptr = nsk->sk_security;
1659 #endif
1660 	memcpy(nsk, osk, offsetof(struct sock, sk_dontcopy_begin));
1661 
1662 	memcpy(&nsk->sk_dontcopy_end, &osk->sk_dontcopy_end,
1663 	       prot->obj_size - offsetof(struct sock, sk_dontcopy_end));
1664 
1665 #ifdef CONFIG_SECURITY_NETWORK
1666 	nsk->sk_security = sptr;
1667 	security_sk_clone(osk, nsk);
1668 #endif
1669 }
1670 
1671 static struct sock *sk_prot_alloc(struct proto *prot, gfp_t priority,
1672 		int family)
1673 {
1674 	struct sock *sk;
1675 	struct kmem_cache *slab;
1676 
1677 	slab = prot->slab;
1678 	if (slab != NULL) {
1679 		sk = kmem_cache_alloc(slab, priority & ~__GFP_ZERO);
1680 		if (!sk)
1681 			return sk;
1682 		if (want_init_on_alloc(priority))
1683 			sk_prot_clear_nulls(sk, prot->obj_size);
1684 	} else
1685 		sk = kmalloc(prot->obj_size, priority);
1686 
1687 	if (sk != NULL) {
1688 		if (security_sk_alloc(sk, family, priority))
1689 			goto out_free;
1690 
1691 		if (!try_module_get(prot->owner))
1692 			goto out_free_sec;
1693 		sk_tx_queue_clear(sk);
1694 	}
1695 
1696 	return sk;
1697 
1698 out_free_sec:
1699 	security_sk_free(sk);
1700 out_free:
1701 	if (slab != NULL)
1702 		kmem_cache_free(slab, sk);
1703 	else
1704 		kfree(sk);
1705 	return NULL;
1706 }
1707 
1708 static void sk_prot_free(struct proto *prot, struct sock *sk)
1709 {
1710 	struct kmem_cache *slab;
1711 	struct module *owner;
1712 
1713 	owner = prot->owner;
1714 	slab = prot->slab;
1715 
1716 	cgroup_sk_free(&sk->sk_cgrp_data);
1717 	mem_cgroup_sk_free(sk);
1718 	security_sk_free(sk);
1719 	if (slab != NULL)
1720 		kmem_cache_free(slab, sk);
1721 	else
1722 		kfree(sk);
1723 	module_put(owner);
1724 }
1725 
1726 /**
1727  *	sk_alloc - All socket objects are allocated here
1728  *	@net: the applicable net namespace
1729  *	@family: protocol family
1730  *	@priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
1731  *	@prot: struct proto associated with this new sock instance
1732  *	@kern: is this to be a kernel socket?
1733  */
1734 struct sock *sk_alloc(struct net *net, int family, gfp_t priority,
1735 		      struct proto *prot, int kern)
1736 {
1737 	struct sock *sk;
1738 
1739 	sk = sk_prot_alloc(prot, priority | __GFP_ZERO, family);
1740 	if (sk) {
1741 		sk->sk_family = family;
1742 		/*
1743 		 * See comment in struct sock definition to understand
1744 		 * why we need sk_prot_creator -acme
1745 		 */
1746 		sk->sk_prot = sk->sk_prot_creator = prot;
1747 		sk->sk_kern_sock = kern;
1748 		sock_lock_init(sk);
1749 		sk->sk_net_refcnt = kern ? 0 : 1;
1750 		if (likely(sk->sk_net_refcnt)) {
1751 			get_net(net);
1752 			sock_inuse_add(net, 1);
1753 		}
1754 
1755 		sock_net_set(sk, net);
1756 		refcount_set(&sk->sk_wmem_alloc, 1);
1757 
1758 		mem_cgroup_sk_alloc(sk);
1759 		cgroup_sk_alloc(&sk->sk_cgrp_data);
1760 		sock_update_classid(&sk->sk_cgrp_data);
1761 		sock_update_netprioidx(&sk->sk_cgrp_data);
1762 		sk_tx_queue_clear(sk);
1763 	}
1764 
1765 	return sk;
1766 }
1767 EXPORT_SYMBOL(sk_alloc);
1768 
1769 /* Sockets having SOCK_RCU_FREE will call this function after one RCU
1770  * grace period. This is the case for UDP sockets and TCP listeners.
1771  */
1772 static void __sk_destruct(struct rcu_head *head)
1773 {
1774 	struct sock *sk = container_of(head, struct sock, sk_rcu);
1775 	struct sk_filter *filter;
1776 
1777 	if (sk->sk_destruct)
1778 		sk->sk_destruct(sk);
1779 
1780 	filter = rcu_dereference_check(sk->sk_filter,
1781 				       refcount_read(&sk->sk_wmem_alloc) == 0);
1782 	if (filter) {
1783 		sk_filter_uncharge(sk, filter);
1784 		RCU_INIT_POINTER(sk->sk_filter, NULL);
1785 	}
1786 
1787 	sock_disable_timestamp(sk, SK_FLAGS_TIMESTAMP);
1788 
1789 #ifdef CONFIG_BPF_SYSCALL
1790 	bpf_sk_storage_free(sk);
1791 #endif
1792 
1793 	if (atomic_read(&sk->sk_omem_alloc))
1794 		pr_debug("%s: optmem leakage (%d bytes) detected\n",
1795 			 __func__, atomic_read(&sk->sk_omem_alloc));
1796 
1797 	if (sk->sk_frag.page) {
1798 		put_page(sk->sk_frag.page);
1799 		sk->sk_frag.page = NULL;
1800 	}
1801 
1802 	if (sk->sk_peer_cred)
1803 		put_cred(sk->sk_peer_cred);
1804 	put_pid(sk->sk_peer_pid);
1805 	if (likely(sk->sk_net_refcnt))
1806 		put_net(sock_net(sk));
1807 	sk_prot_free(sk->sk_prot_creator, sk);
1808 }
1809 
1810 void sk_destruct(struct sock *sk)
1811 {
1812 	bool use_call_rcu = sock_flag(sk, SOCK_RCU_FREE);
1813 
1814 	if (rcu_access_pointer(sk->sk_reuseport_cb)) {
1815 		reuseport_detach_sock(sk);
1816 		use_call_rcu = true;
1817 	}
1818 
1819 	if (use_call_rcu)
1820 		call_rcu(&sk->sk_rcu, __sk_destruct);
1821 	else
1822 		__sk_destruct(&sk->sk_rcu);
1823 }
1824 
1825 static void __sk_free(struct sock *sk)
1826 {
1827 	if (likely(sk->sk_net_refcnt))
1828 		sock_inuse_add(sock_net(sk), -1);
1829 
1830 	if (unlikely(sk->sk_net_refcnt && sock_diag_has_destroy_listeners(sk)))
1831 		sock_diag_broadcast_destroy(sk);
1832 	else
1833 		sk_destruct(sk);
1834 }
1835 
1836 void sk_free(struct sock *sk)
1837 {
1838 	/*
1839 	 * We subtract one from sk_wmem_alloc and can know if
1840 	 * some packets are still in some tx queue.
1841 	 * If not null, sock_wfree() will call __sk_free(sk) later
1842 	 */
1843 	if (refcount_dec_and_test(&sk->sk_wmem_alloc))
1844 		__sk_free(sk);
1845 }
1846 EXPORT_SYMBOL(sk_free);
1847 
1848 static void sk_init_common(struct sock *sk)
1849 {
1850 	skb_queue_head_init(&sk->sk_receive_queue);
1851 	skb_queue_head_init(&sk->sk_write_queue);
1852 	skb_queue_head_init(&sk->sk_error_queue);
1853 
1854 	rwlock_init(&sk->sk_callback_lock);
1855 	lockdep_set_class_and_name(&sk->sk_receive_queue.lock,
1856 			af_rlock_keys + sk->sk_family,
1857 			af_family_rlock_key_strings[sk->sk_family]);
1858 	lockdep_set_class_and_name(&sk->sk_write_queue.lock,
1859 			af_wlock_keys + sk->sk_family,
1860 			af_family_wlock_key_strings[sk->sk_family]);
1861 	lockdep_set_class_and_name(&sk->sk_error_queue.lock,
1862 			af_elock_keys + sk->sk_family,
1863 			af_family_elock_key_strings[sk->sk_family]);
1864 	lockdep_set_class_and_name(&sk->sk_callback_lock,
1865 			af_callback_keys + sk->sk_family,
1866 			af_family_clock_key_strings[sk->sk_family]);
1867 }
1868 
1869 /**
1870  *	sk_clone_lock - clone a socket, and lock its clone
1871  *	@sk: the socket to clone
1872  *	@priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
1873  *
1874  *	Caller must unlock socket even in error path (bh_unlock_sock(newsk))
1875  */
1876 struct sock *sk_clone_lock(const struct sock *sk, const gfp_t priority)
1877 {
1878 	struct proto *prot = READ_ONCE(sk->sk_prot);
1879 	struct sock *newsk;
1880 	bool is_charged = true;
1881 
1882 	newsk = sk_prot_alloc(prot, priority, sk->sk_family);
1883 	if (newsk != NULL) {
1884 		struct sk_filter *filter;
1885 
1886 		sock_copy(newsk, sk);
1887 
1888 		newsk->sk_prot_creator = prot;
1889 
1890 		/* SANITY */
1891 		if (likely(newsk->sk_net_refcnt))
1892 			get_net(sock_net(newsk));
1893 		sk_node_init(&newsk->sk_node);
1894 		sock_lock_init(newsk);
1895 		bh_lock_sock(newsk);
1896 		newsk->sk_backlog.head	= newsk->sk_backlog.tail = NULL;
1897 		newsk->sk_backlog.len = 0;
1898 
1899 		atomic_set(&newsk->sk_rmem_alloc, 0);
1900 		/*
1901 		 * sk_wmem_alloc set to one (see sk_free() and sock_wfree())
1902 		 */
1903 		refcount_set(&newsk->sk_wmem_alloc, 1);
1904 		atomic_set(&newsk->sk_omem_alloc, 0);
1905 		sk_init_common(newsk);
1906 
1907 		newsk->sk_dst_cache	= NULL;
1908 		newsk->sk_dst_pending_confirm = 0;
1909 		newsk->sk_wmem_queued	= 0;
1910 		newsk->sk_forward_alloc = 0;
1911 		atomic_set(&newsk->sk_drops, 0);
1912 		newsk->sk_send_head	= NULL;
1913 		newsk->sk_userlocks	= sk->sk_userlocks & ~SOCK_BINDPORT_LOCK;
1914 		atomic_set(&newsk->sk_zckey, 0);
1915 
1916 		sock_reset_flag(newsk, SOCK_DONE);
1917 
1918 		/* sk->sk_memcg will be populated at accept() time */
1919 		newsk->sk_memcg = NULL;
1920 
1921 		cgroup_sk_clone(&newsk->sk_cgrp_data);
1922 
1923 		rcu_read_lock();
1924 		filter = rcu_dereference(sk->sk_filter);
1925 		if (filter != NULL)
1926 			/* though it's an empty new sock, the charging may fail
1927 			 * if sysctl_optmem_max was changed between creation of
1928 			 * original socket and cloning
1929 			 */
1930 			is_charged = sk_filter_charge(newsk, filter);
1931 		RCU_INIT_POINTER(newsk->sk_filter, filter);
1932 		rcu_read_unlock();
1933 
1934 		if (unlikely(!is_charged || xfrm_sk_clone_policy(newsk, sk))) {
1935 			/* We need to make sure that we don't uncharge the new
1936 			 * socket if we couldn't charge it in the first place
1937 			 * as otherwise we uncharge the parent's filter.
1938 			 */
1939 			if (!is_charged)
1940 				RCU_INIT_POINTER(newsk->sk_filter, NULL);
1941 			sk_free_unlock_clone(newsk);
1942 			newsk = NULL;
1943 			goto out;
1944 		}
1945 		RCU_INIT_POINTER(newsk->sk_reuseport_cb, NULL);
1946 
1947 		if (bpf_sk_storage_clone(sk, newsk)) {
1948 			sk_free_unlock_clone(newsk);
1949 			newsk = NULL;
1950 			goto out;
1951 		}
1952 
1953 		/* Clear sk_user_data if parent had the pointer tagged
1954 		 * as not suitable for copying when cloning.
1955 		 */
1956 		if (sk_user_data_is_nocopy(newsk))
1957 			newsk->sk_user_data = NULL;
1958 
1959 		newsk->sk_err	   = 0;
1960 		newsk->sk_err_soft = 0;
1961 		newsk->sk_priority = 0;
1962 		newsk->sk_incoming_cpu = raw_smp_processor_id();
1963 		if (likely(newsk->sk_net_refcnt))
1964 			sock_inuse_add(sock_net(newsk), 1);
1965 
1966 		/*
1967 		 * Before updating sk_refcnt, we must commit prior changes to memory
1968 		 * (Documentation/RCU/rculist_nulls.rst for details)
1969 		 */
1970 		smp_wmb();
1971 		refcount_set(&newsk->sk_refcnt, 2);
1972 
1973 		/*
1974 		 * Increment the counter in the same struct proto as the master
1975 		 * sock (sk_refcnt_debug_inc uses newsk->sk_prot->socks, that
1976 		 * is the same as sk->sk_prot->socks, as this field was copied
1977 		 * with memcpy).
1978 		 *
1979 		 * This _changes_ the previous behaviour, where
1980 		 * tcp_create_openreq_child always was incrementing the
1981 		 * equivalent to tcp_prot->socks (inet_sock_nr), so this have
1982 		 * to be taken into account in all callers. -acme
1983 		 */
1984 		sk_refcnt_debug_inc(newsk);
1985 		sk_set_socket(newsk, NULL);
1986 		sk_tx_queue_clear(newsk);
1987 		RCU_INIT_POINTER(newsk->sk_wq, NULL);
1988 
1989 		if (newsk->sk_prot->sockets_allocated)
1990 			sk_sockets_allocated_inc(newsk);
1991 
1992 		if (sock_needs_netstamp(sk) &&
1993 		    newsk->sk_flags & SK_FLAGS_TIMESTAMP)
1994 			net_enable_timestamp();
1995 	}
1996 out:
1997 	return newsk;
1998 }
1999 EXPORT_SYMBOL_GPL(sk_clone_lock);
2000 
2001 void sk_free_unlock_clone(struct sock *sk)
2002 {
2003 	/* It is still raw copy of parent, so invalidate
2004 	 * destructor and make plain sk_free() */
2005 	sk->sk_destruct = NULL;
2006 	bh_unlock_sock(sk);
2007 	sk_free(sk);
2008 }
2009 EXPORT_SYMBOL_GPL(sk_free_unlock_clone);
2010 
2011 void sk_setup_caps(struct sock *sk, struct dst_entry *dst)
2012 {
2013 	u32 max_segs = 1;
2014 
2015 	sk_dst_set(sk, dst);
2016 	sk->sk_route_caps = dst->dev->features | sk->sk_route_forced_caps;
2017 	if (sk->sk_route_caps & NETIF_F_GSO)
2018 		sk->sk_route_caps |= NETIF_F_GSO_SOFTWARE;
2019 	sk->sk_route_caps &= ~sk->sk_route_nocaps;
2020 	if (sk_can_gso(sk)) {
2021 		if (dst->header_len && !xfrm_dst_offload_ok(dst)) {
2022 			sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
2023 		} else {
2024 			sk->sk_route_caps |= NETIF_F_SG | NETIF_F_HW_CSUM;
2025 			sk->sk_gso_max_size = dst->dev->gso_max_size;
2026 			max_segs = max_t(u32, dst->dev->gso_max_segs, 1);
2027 		}
2028 	}
2029 	sk->sk_gso_max_segs = max_segs;
2030 }
2031 EXPORT_SYMBOL_GPL(sk_setup_caps);
2032 
2033 /*
2034  *	Simple resource managers for sockets.
2035  */
2036 
2037 
2038 /*
2039  * Write buffer destructor automatically called from kfree_skb.
2040  */
2041 void sock_wfree(struct sk_buff *skb)
2042 {
2043 	struct sock *sk = skb->sk;
2044 	unsigned int len = skb->truesize;
2045 
2046 	if (!sock_flag(sk, SOCK_USE_WRITE_QUEUE)) {
2047 		/*
2048 		 * Keep a reference on sk_wmem_alloc, this will be released
2049 		 * after sk_write_space() call
2050 		 */
2051 		WARN_ON(refcount_sub_and_test(len - 1, &sk->sk_wmem_alloc));
2052 		sk->sk_write_space(sk);
2053 		len = 1;
2054 	}
2055 	/*
2056 	 * if sk_wmem_alloc reaches 0, we must finish what sk_free()
2057 	 * could not do because of in-flight packets
2058 	 */
2059 	if (refcount_sub_and_test(len, &sk->sk_wmem_alloc))
2060 		__sk_free(sk);
2061 }
2062 EXPORT_SYMBOL(sock_wfree);
2063 
2064 /* This variant of sock_wfree() is used by TCP,
2065  * since it sets SOCK_USE_WRITE_QUEUE.
2066  */
2067 void __sock_wfree(struct sk_buff *skb)
2068 {
2069 	struct sock *sk = skb->sk;
2070 
2071 	if (refcount_sub_and_test(skb->truesize, &sk->sk_wmem_alloc))
2072 		__sk_free(sk);
2073 }
2074 
2075 void skb_set_owner_w(struct sk_buff *skb, struct sock *sk)
2076 {
2077 	skb_orphan(skb);
2078 	skb->sk = sk;
2079 #ifdef CONFIG_INET
2080 	if (unlikely(!sk_fullsock(sk))) {
2081 		skb->destructor = sock_edemux;
2082 		sock_hold(sk);
2083 		return;
2084 	}
2085 #endif
2086 	skb->destructor = sock_wfree;
2087 	skb_set_hash_from_sk(skb, sk);
2088 	/*
2089 	 * We used to take a refcount on sk, but following operation
2090 	 * is enough to guarantee sk_free() wont free this sock until
2091 	 * all in-flight packets are completed
2092 	 */
2093 	refcount_add(skb->truesize, &sk->sk_wmem_alloc);
2094 }
2095 EXPORT_SYMBOL(skb_set_owner_w);
2096 
2097 static bool can_skb_orphan_partial(const struct sk_buff *skb)
2098 {
2099 #ifdef CONFIG_TLS_DEVICE
2100 	/* Drivers depend on in-order delivery for crypto offload,
2101 	 * partial orphan breaks out-of-order-OK logic.
2102 	 */
2103 	if (skb->decrypted)
2104 		return false;
2105 #endif
2106 	return (skb->destructor == sock_wfree ||
2107 		(IS_ENABLED(CONFIG_INET) && skb->destructor == tcp_wfree));
2108 }
2109 
2110 /* This helper is used by netem, as it can hold packets in its
2111  * delay queue. We want to allow the owner socket to send more
2112  * packets, as if they were already TX completed by a typical driver.
2113  * But we also want to keep skb->sk set because some packet schedulers
2114  * rely on it (sch_fq for example).
2115  */
2116 void skb_orphan_partial(struct sk_buff *skb)
2117 {
2118 	if (skb_is_tcp_pure_ack(skb))
2119 		return;
2120 
2121 	if (can_skb_orphan_partial(skb)) {
2122 		struct sock *sk = skb->sk;
2123 
2124 		if (refcount_inc_not_zero(&sk->sk_refcnt)) {
2125 			WARN_ON(refcount_sub_and_test(skb->truesize, &sk->sk_wmem_alloc));
2126 			skb->destructor = sock_efree;
2127 		}
2128 	} else {
2129 		skb_orphan(skb);
2130 	}
2131 }
2132 EXPORT_SYMBOL(skb_orphan_partial);
2133 
2134 /*
2135  * Read buffer destructor automatically called from kfree_skb.
2136  */
2137 void sock_rfree(struct sk_buff *skb)
2138 {
2139 	struct sock *sk = skb->sk;
2140 	unsigned int len = skb->truesize;
2141 
2142 	atomic_sub(len, &sk->sk_rmem_alloc);
2143 	sk_mem_uncharge(sk, len);
2144 }
2145 EXPORT_SYMBOL(sock_rfree);
2146 
2147 /*
2148  * Buffer destructor for skbs that are not used directly in read or write
2149  * path, e.g. for error handler skbs. Automatically called from kfree_skb.
2150  */
2151 void sock_efree(struct sk_buff *skb)
2152 {
2153 	sock_put(skb->sk);
2154 }
2155 EXPORT_SYMBOL(sock_efree);
2156 
2157 /* Buffer destructor for prefetch/receive path where reference count may
2158  * not be held, e.g. for listen sockets.
2159  */
2160 #ifdef CONFIG_INET
2161 void sock_pfree(struct sk_buff *skb)
2162 {
2163 	if (sk_is_refcounted(skb->sk))
2164 		sock_gen_put(skb->sk);
2165 }
2166 EXPORT_SYMBOL(sock_pfree);
2167 #endif /* CONFIG_INET */
2168 
2169 kuid_t sock_i_uid(struct sock *sk)
2170 {
2171 	kuid_t uid;
2172 
2173 	read_lock_bh(&sk->sk_callback_lock);
2174 	uid = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_uid : GLOBAL_ROOT_UID;
2175 	read_unlock_bh(&sk->sk_callback_lock);
2176 	return uid;
2177 }
2178 EXPORT_SYMBOL(sock_i_uid);
2179 
2180 unsigned long sock_i_ino(struct sock *sk)
2181 {
2182 	unsigned long ino;
2183 
2184 	read_lock_bh(&sk->sk_callback_lock);
2185 	ino = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_ino : 0;
2186 	read_unlock_bh(&sk->sk_callback_lock);
2187 	return ino;
2188 }
2189 EXPORT_SYMBOL(sock_i_ino);
2190 
2191 /*
2192  * Allocate a skb from the socket's send buffer.
2193  */
2194 struct sk_buff *sock_wmalloc(struct sock *sk, unsigned long size, int force,
2195 			     gfp_t priority)
2196 {
2197 	if (force ||
2198 	    refcount_read(&sk->sk_wmem_alloc) < READ_ONCE(sk->sk_sndbuf)) {
2199 		struct sk_buff *skb = alloc_skb(size, priority);
2200 
2201 		if (skb) {
2202 			skb_set_owner_w(skb, sk);
2203 			return skb;
2204 		}
2205 	}
2206 	return NULL;
2207 }
2208 EXPORT_SYMBOL(sock_wmalloc);
2209 
2210 static void sock_ofree(struct sk_buff *skb)
2211 {
2212 	struct sock *sk = skb->sk;
2213 
2214 	atomic_sub(skb->truesize, &sk->sk_omem_alloc);
2215 }
2216 
2217 struct sk_buff *sock_omalloc(struct sock *sk, unsigned long size,
2218 			     gfp_t priority)
2219 {
2220 	struct sk_buff *skb;
2221 
2222 	/* small safe race: SKB_TRUESIZE may differ from final skb->truesize */
2223 	if (atomic_read(&sk->sk_omem_alloc) + SKB_TRUESIZE(size) >
2224 	    sysctl_optmem_max)
2225 		return NULL;
2226 
2227 	skb = alloc_skb(size, priority);
2228 	if (!skb)
2229 		return NULL;
2230 
2231 	atomic_add(skb->truesize, &sk->sk_omem_alloc);
2232 	skb->sk = sk;
2233 	skb->destructor = sock_ofree;
2234 	return skb;
2235 }
2236 
2237 /*
2238  * Allocate a memory block from the socket's option memory buffer.
2239  */
2240 void *sock_kmalloc(struct sock *sk, int size, gfp_t priority)
2241 {
2242 	if ((unsigned int)size <= sysctl_optmem_max &&
2243 	    atomic_read(&sk->sk_omem_alloc) + size < sysctl_optmem_max) {
2244 		void *mem;
2245 		/* First do the add, to avoid the race if kmalloc
2246 		 * might sleep.
2247 		 */
2248 		atomic_add(size, &sk->sk_omem_alloc);
2249 		mem = kmalloc(size, priority);
2250 		if (mem)
2251 			return mem;
2252 		atomic_sub(size, &sk->sk_omem_alloc);
2253 	}
2254 	return NULL;
2255 }
2256 EXPORT_SYMBOL(sock_kmalloc);
2257 
2258 /* Free an option memory block. Note, we actually want the inline
2259  * here as this allows gcc to detect the nullify and fold away the
2260  * condition entirely.
2261  */
2262 static inline void __sock_kfree_s(struct sock *sk, void *mem, int size,
2263 				  const bool nullify)
2264 {
2265 	if (WARN_ON_ONCE(!mem))
2266 		return;
2267 	if (nullify)
2268 		kfree_sensitive(mem);
2269 	else
2270 		kfree(mem);
2271 	atomic_sub(size, &sk->sk_omem_alloc);
2272 }
2273 
2274 void sock_kfree_s(struct sock *sk, void *mem, int size)
2275 {
2276 	__sock_kfree_s(sk, mem, size, false);
2277 }
2278 EXPORT_SYMBOL(sock_kfree_s);
2279 
2280 void sock_kzfree_s(struct sock *sk, void *mem, int size)
2281 {
2282 	__sock_kfree_s(sk, mem, size, true);
2283 }
2284 EXPORT_SYMBOL(sock_kzfree_s);
2285 
2286 /* It is almost wait_for_tcp_memory minus release_sock/lock_sock.
2287    I think, these locks should be removed for datagram sockets.
2288  */
2289 static long sock_wait_for_wmem(struct sock *sk, long timeo)
2290 {
2291 	DEFINE_WAIT(wait);
2292 
2293 	sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
2294 	for (;;) {
2295 		if (!timeo)
2296 			break;
2297 		if (signal_pending(current))
2298 			break;
2299 		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
2300 		prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
2301 		if (refcount_read(&sk->sk_wmem_alloc) < READ_ONCE(sk->sk_sndbuf))
2302 			break;
2303 		if (sk->sk_shutdown & SEND_SHUTDOWN)
2304 			break;
2305 		if (sk->sk_err)
2306 			break;
2307 		timeo = schedule_timeout(timeo);
2308 	}
2309 	finish_wait(sk_sleep(sk), &wait);
2310 	return timeo;
2311 }
2312 
2313 
2314 /*
2315  *	Generic send/receive buffer handlers
2316  */
2317 
2318 struct sk_buff *sock_alloc_send_pskb(struct sock *sk, unsigned long header_len,
2319 				     unsigned long data_len, int noblock,
2320 				     int *errcode, int max_page_order)
2321 {
2322 	struct sk_buff *skb;
2323 	long timeo;
2324 	int err;
2325 
2326 	timeo = sock_sndtimeo(sk, noblock);
2327 	for (;;) {
2328 		err = sock_error(sk);
2329 		if (err != 0)
2330 			goto failure;
2331 
2332 		err = -EPIPE;
2333 		if (sk->sk_shutdown & SEND_SHUTDOWN)
2334 			goto failure;
2335 
2336 		if (sk_wmem_alloc_get(sk) < READ_ONCE(sk->sk_sndbuf))
2337 			break;
2338 
2339 		sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
2340 		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
2341 		err = -EAGAIN;
2342 		if (!timeo)
2343 			goto failure;
2344 		if (signal_pending(current))
2345 			goto interrupted;
2346 		timeo = sock_wait_for_wmem(sk, timeo);
2347 	}
2348 	skb = alloc_skb_with_frags(header_len, data_len, max_page_order,
2349 				   errcode, sk->sk_allocation);
2350 	if (skb)
2351 		skb_set_owner_w(skb, sk);
2352 	return skb;
2353 
2354 interrupted:
2355 	err = sock_intr_errno(timeo);
2356 failure:
2357 	*errcode = err;
2358 	return NULL;
2359 }
2360 EXPORT_SYMBOL(sock_alloc_send_pskb);
2361 
2362 struct sk_buff *sock_alloc_send_skb(struct sock *sk, unsigned long size,
2363 				    int noblock, int *errcode)
2364 {
2365 	return sock_alloc_send_pskb(sk, size, 0, noblock, errcode, 0);
2366 }
2367 EXPORT_SYMBOL(sock_alloc_send_skb);
2368 
2369 int __sock_cmsg_send(struct sock *sk, struct msghdr *msg, struct cmsghdr *cmsg,
2370 		     struct sockcm_cookie *sockc)
2371 {
2372 	u32 tsflags;
2373 
2374 	switch (cmsg->cmsg_type) {
2375 	case SO_MARK:
2376 		if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
2377 			return -EPERM;
2378 		if (cmsg->cmsg_len != CMSG_LEN(sizeof(u32)))
2379 			return -EINVAL;
2380 		sockc->mark = *(u32 *)CMSG_DATA(cmsg);
2381 		break;
2382 	case SO_TIMESTAMPING_OLD:
2383 		if (cmsg->cmsg_len != CMSG_LEN(sizeof(u32)))
2384 			return -EINVAL;
2385 
2386 		tsflags = *(u32 *)CMSG_DATA(cmsg);
2387 		if (tsflags & ~SOF_TIMESTAMPING_TX_RECORD_MASK)
2388 			return -EINVAL;
2389 
2390 		sockc->tsflags &= ~SOF_TIMESTAMPING_TX_RECORD_MASK;
2391 		sockc->tsflags |= tsflags;
2392 		break;
2393 	case SCM_TXTIME:
2394 		if (!sock_flag(sk, SOCK_TXTIME))
2395 			return -EINVAL;
2396 		if (cmsg->cmsg_len != CMSG_LEN(sizeof(u64)))
2397 			return -EINVAL;
2398 		sockc->transmit_time = get_unaligned((u64 *)CMSG_DATA(cmsg));
2399 		break;
2400 	/* SCM_RIGHTS and SCM_CREDENTIALS are semantically in SOL_UNIX. */
2401 	case SCM_RIGHTS:
2402 	case SCM_CREDENTIALS:
2403 		break;
2404 	default:
2405 		return -EINVAL;
2406 	}
2407 	return 0;
2408 }
2409 EXPORT_SYMBOL(__sock_cmsg_send);
2410 
2411 int sock_cmsg_send(struct sock *sk, struct msghdr *msg,
2412 		   struct sockcm_cookie *sockc)
2413 {
2414 	struct cmsghdr *cmsg;
2415 	int ret;
2416 
2417 	for_each_cmsghdr(cmsg, msg) {
2418 		if (!CMSG_OK(msg, cmsg))
2419 			return -EINVAL;
2420 		if (cmsg->cmsg_level != SOL_SOCKET)
2421 			continue;
2422 		ret = __sock_cmsg_send(sk, msg, cmsg, sockc);
2423 		if (ret)
2424 			return ret;
2425 	}
2426 	return 0;
2427 }
2428 EXPORT_SYMBOL(sock_cmsg_send);
2429 
2430 static void sk_enter_memory_pressure(struct sock *sk)
2431 {
2432 	if (!sk->sk_prot->enter_memory_pressure)
2433 		return;
2434 
2435 	sk->sk_prot->enter_memory_pressure(sk);
2436 }
2437 
2438 static void sk_leave_memory_pressure(struct sock *sk)
2439 {
2440 	if (sk->sk_prot->leave_memory_pressure) {
2441 		sk->sk_prot->leave_memory_pressure(sk);
2442 	} else {
2443 		unsigned long *memory_pressure = sk->sk_prot->memory_pressure;
2444 
2445 		if (memory_pressure && READ_ONCE(*memory_pressure))
2446 			WRITE_ONCE(*memory_pressure, 0);
2447 	}
2448 }
2449 
2450 #define SKB_FRAG_PAGE_ORDER	get_order(32768)
2451 DEFINE_STATIC_KEY_FALSE(net_high_order_alloc_disable_key);
2452 
2453 /**
2454  * skb_page_frag_refill - check that a page_frag contains enough room
2455  * @sz: minimum size of the fragment we want to get
2456  * @pfrag: pointer to page_frag
2457  * @gfp: priority for memory allocation
2458  *
2459  * Note: While this allocator tries to use high order pages, there is
2460  * no guarantee that allocations succeed. Therefore, @sz MUST be
2461  * less or equal than PAGE_SIZE.
2462  */
2463 bool skb_page_frag_refill(unsigned int sz, struct page_frag *pfrag, gfp_t gfp)
2464 {
2465 	if (pfrag->page) {
2466 		if (page_ref_count(pfrag->page) == 1) {
2467 			pfrag->offset = 0;
2468 			return true;
2469 		}
2470 		if (pfrag->offset + sz <= pfrag->size)
2471 			return true;
2472 		put_page(pfrag->page);
2473 	}
2474 
2475 	pfrag->offset = 0;
2476 	if (SKB_FRAG_PAGE_ORDER &&
2477 	    !static_branch_unlikely(&net_high_order_alloc_disable_key)) {
2478 		/* Avoid direct reclaim but allow kswapd to wake */
2479 		pfrag->page = alloc_pages((gfp & ~__GFP_DIRECT_RECLAIM) |
2480 					  __GFP_COMP | __GFP_NOWARN |
2481 					  __GFP_NORETRY,
2482 					  SKB_FRAG_PAGE_ORDER);
2483 		if (likely(pfrag->page)) {
2484 			pfrag->size = PAGE_SIZE << SKB_FRAG_PAGE_ORDER;
2485 			return true;
2486 		}
2487 	}
2488 	pfrag->page = alloc_page(gfp);
2489 	if (likely(pfrag->page)) {
2490 		pfrag->size = PAGE_SIZE;
2491 		return true;
2492 	}
2493 	return false;
2494 }
2495 EXPORT_SYMBOL(skb_page_frag_refill);
2496 
2497 bool sk_page_frag_refill(struct sock *sk, struct page_frag *pfrag)
2498 {
2499 	if (likely(skb_page_frag_refill(32U, pfrag, sk->sk_allocation)))
2500 		return true;
2501 
2502 	sk_enter_memory_pressure(sk);
2503 	sk_stream_moderate_sndbuf(sk);
2504 	return false;
2505 }
2506 EXPORT_SYMBOL(sk_page_frag_refill);
2507 
2508 void __lock_sock(struct sock *sk)
2509 	__releases(&sk->sk_lock.slock)
2510 	__acquires(&sk->sk_lock.slock)
2511 {
2512 	DEFINE_WAIT(wait);
2513 
2514 	for (;;) {
2515 		prepare_to_wait_exclusive(&sk->sk_lock.wq, &wait,
2516 					TASK_UNINTERRUPTIBLE);
2517 		spin_unlock_bh(&sk->sk_lock.slock);
2518 		schedule();
2519 		spin_lock_bh(&sk->sk_lock.slock);
2520 		if (!sock_owned_by_user(sk))
2521 			break;
2522 	}
2523 	finish_wait(&sk->sk_lock.wq, &wait);
2524 }
2525 
2526 void __release_sock(struct sock *sk)
2527 	__releases(&sk->sk_lock.slock)
2528 	__acquires(&sk->sk_lock.slock)
2529 {
2530 	struct sk_buff *skb, *next;
2531 
2532 	while ((skb = sk->sk_backlog.head) != NULL) {
2533 		sk->sk_backlog.head = sk->sk_backlog.tail = NULL;
2534 
2535 		spin_unlock_bh(&sk->sk_lock.slock);
2536 
2537 		do {
2538 			next = skb->next;
2539 			prefetch(next);
2540 			WARN_ON_ONCE(skb_dst_is_noref(skb));
2541 			skb_mark_not_on_list(skb);
2542 			sk_backlog_rcv(sk, skb);
2543 
2544 			cond_resched();
2545 
2546 			skb = next;
2547 		} while (skb != NULL);
2548 
2549 		spin_lock_bh(&sk->sk_lock.slock);
2550 	}
2551 
2552 	/*
2553 	 * Doing the zeroing here guarantee we can not loop forever
2554 	 * while a wild producer attempts to flood us.
2555 	 */
2556 	sk->sk_backlog.len = 0;
2557 }
2558 
2559 void __sk_flush_backlog(struct sock *sk)
2560 {
2561 	spin_lock_bh(&sk->sk_lock.slock);
2562 	__release_sock(sk);
2563 	spin_unlock_bh(&sk->sk_lock.slock);
2564 }
2565 
2566 /**
2567  * sk_wait_data - wait for data to arrive at sk_receive_queue
2568  * @sk:    sock to wait on
2569  * @timeo: for how long
2570  * @skb:   last skb seen on sk_receive_queue
2571  *
2572  * Now socket state including sk->sk_err is changed only under lock,
2573  * hence we may omit checks after joining wait queue.
2574  * We check receive queue before schedule() only as optimization;
2575  * it is very likely that release_sock() added new data.
2576  */
2577 int sk_wait_data(struct sock *sk, long *timeo, const struct sk_buff *skb)
2578 {
2579 	DEFINE_WAIT_FUNC(wait, woken_wake_function);
2580 	int rc;
2581 
2582 	add_wait_queue(sk_sleep(sk), &wait);
2583 	sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
2584 	rc = sk_wait_event(sk, timeo, skb_peek_tail(&sk->sk_receive_queue) != skb, &wait);
2585 	sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
2586 	remove_wait_queue(sk_sleep(sk), &wait);
2587 	return rc;
2588 }
2589 EXPORT_SYMBOL(sk_wait_data);
2590 
2591 /**
2592  *	__sk_mem_raise_allocated - increase memory_allocated
2593  *	@sk: socket
2594  *	@size: memory size to allocate
2595  *	@amt: pages to allocate
2596  *	@kind: allocation type
2597  *
2598  *	Similar to __sk_mem_schedule(), but does not update sk_forward_alloc
2599  */
2600 int __sk_mem_raise_allocated(struct sock *sk, int size, int amt, int kind)
2601 {
2602 	struct proto *prot = sk->sk_prot;
2603 	long allocated = sk_memory_allocated_add(sk, amt);
2604 	bool charged = true;
2605 
2606 	if (mem_cgroup_sockets_enabled && sk->sk_memcg &&
2607 	    !(charged = mem_cgroup_charge_skmem(sk->sk_memcg, amt)))
2608 		goto suppress_allocation;
2609 
2610 	/* Under limit. */
2611 	if (allocated <= sk_prot_mem_limits(sk, 0)) {
2612 		sk_leave_memory_pressure(sk);
2613 		return 1;
2614 	}
2615 
2616 	/* Under pressure. */
2617 	if (allocated > sk_prot_mem_limits(sk, 1))
2618 		sk_enter_memory_pressure(sk);
2619 
2620 	/* Over hard limit. */
2621 	if (allocated > sk_prot_mem_limits(sk, 2))
2622 		goto suppress_allocation;
2623 
2624 	/* guarantee minimum buffer size under pressure */
2625 	if (kind == SK_MEM_RECV) {
2626 		if (atomic_read(&sk->sk_rmem_alloc) < sk_get_rmem0(sk, prot))
2627 			return 1;
2628 
2629 	} else { /* SK_MEM_SEND */
2630 		int wmem0 = sk_get_wmem0(sk, prot);
2631 
2632 		if (sk->sk_type == SOCK_STREAM) {
2633 			if (sk->sk_wmem_queued < wmem0)
2634 				return 1;
2635 		} else if (refcount_read(&sk->sk_wmem_alloc) < wmem0) {
2636 				return 1;
2637 		}
2638 	}
2639 
2640 	if (sk_has_memory_pressure(sk)) {
2641 		u64 alloc;
2642 
2643 		if (!sk_under_memory_pressure(sk))
2644 			return 1;
2645 		alloc = sk_sockets_allocated_read_positive(sk);
2646 		if (sk_prot_mem_limits(sk, 2) > alloc *
2647 		    sk_mem_pages(sk->sk_wmem_queued +
2648 				 atomic_read(&sk->sk_rmem_alloc) +
2649 				 sk->sk_forward_alloc))
2650 			return 1;
2651 	}
2652 
2653 suppress_allocation:
2654 
2655 	if (kind == SK_MEM_SEND && sk->sk_type == SOCK_STREAM) {
2656 		sk_stream_moderate_sndbuf(sk);
2657 
2658 		/* Fail only if socket is _under_ its sndbuf.
2659 		 * In this case we cannot block, so that we have to fail.
2660 		 */
2661 		if (sk->sk_wmem_queued + size >= sk->sk_sndbuf)
2662 			return 1;
2663 	}
2664 
2665 	if (kind == SK_MEM_SEND || (kind == SK_MEM_RECV && charged))
2666 		trace_sock_exceed_buf_limit(sk, prot, allocated, kind);
2667 
2668 	sk_memory_allocated_sub(sk, amt);
2669 
2670 	if (mem_cgroup_sockets_enabled && sk->sk_memcg)
2671 		mem_cgroup_uncharge_skmem(sk->sk_memcg, amt);
2672 
2673 	return 0;
2674 }
2675 EXPORT_SYMBOL(__sk_mem_raise_allocated);
2676 
2677 /**
2678  *	__sk_mem_schedule - increase sk_forward_alloc and memory_allocated
2679  *	@sk: socket
2680  *	@size: memory size to allocate
2681  *	@kind: allocation type
2682  *
2683  *	If kind is SK_MEM_SEND, it means wmem allocation. Otherwise it means
2684  *	rmem allocation. This function assumes that protocols which have
2685  *	memory_pressure use sk_wmem_queued as write buffer accounting.
2686  */
2687 int __sk_mem_schedule(struct sock *sk, int size, int kind)
2688 {
2689 	int ret, amt = sk_mem_pages(size);
2690 
2691 	sk->sk_forward_alloc += amt << SK_MEM_QUANTUM_SHIFT;
2692 	ret = __sk_mem_raise_allocated(sk, size, amt, kind);
2693 	if (!ret)
2694 		sk->sk_forward_alloc -= amt << SK_MEM_QUANTUM_SHIFT;
2695 	return ret;
2696 }
2697 EXPORT_SYMBOL(__sk_mem_schedule);
2698 
2699 /**
2700  *	__sk_mem_reduce_allocated - reclaim memory_allocated
2701  *	@sk: socket
2702  *	@amount: number of quanta
2703  *
2704  *	Similar to __sk_mem_reclaim(), but does not update sk_forward_alloc
2705  */
2706 void __sk_mem_reduce_allocated(struct sock *sk, int amount)
2707 {
2708 	sk_memory_allocated_sub(sk, amount);
2709 
2710 	if (mem_cgroup_sockets_enabled && sk->sk_memcg)
2711 		mem_cgroup_uncharge_skmem(sk->sk_memcg, amount);
2712 
2713 	if (sk_under_memory_pressure(sk) &&
2714 	    (sk_memory_allocated(sk) < sk_prot_mem_limits(sk, 0)))
2715 		sk_leave_memory_pressure(sk);
2716 }
2717 EXPORT_SYMBOL(__sk_mem_reduce_allocated);
2718 
2719 /**
2720  *	__sk_mem_reclaim - reclaim sk_forward_alloc and memory_allocated
2721  *	@sk: socket
2722  *	@amount: number of bytes (rounded down to a SK_MEM_QUANTUM multiple)
2723  */
2724 void __sk_mem_reclaim(struct sock *sk, int amount)
2725 {
2726 	amount >>= SK_MEM_QUANTUM_SHIFT;
2727 	sk->sk_forward_alloc -= amount << SK_MEM_QUANTUM_SHIFT;
2728 	__sk_mem_reduce_allocated(sk, amount);
2729 }
2730 EXPORT_SYMBOL(__sk_mem_reclaim);
2731 
2732 int sk_set_peek_off(struct sock *sk, int val)
2733 {
2734 	sk->sk_peek_off = val;
2735 	return 0;
2736 }
2737 EXPORT_SYMBOL_GPL(sk_set_peek_off);
2738 
2739 /*
2740  * Set of default routines for initialising struct proto_ops when
2741  * the protocol does not support a particular function. In certain
2742  * cases where it makes no sense for a protocol to have a "do nothing"
2743  * function, some default processing is provided.
2744  */
2745 
2746 int sock_no_bind(struct socket *sock, struct sockaddr *saddr, int len)
2747 {
2748 	return -EOPNOTSUPP;
2749 }
2750 EXPORT_SYMBOL(sock_no_bind);
2751 
2752 int sock_no_connect(struct socket *sock, struct sockaddr *saddr,
2753 		    int len, int flags)
2754 {
2755 	return -EOPNOTSUPP;
2756 }
2757 EXPORT_SYMBOL(sock_no_connect);
2758 
2759 int sock_no_socketpair(struct socket *sock1, struct socket *sock2)
2760 {
2761 	return -EOPNOTSUPP;
2762 }
2763 EXPORT_SYMBOL(sock_no_socketpair);
2764 
2765 int sock_no_accept(struct socket *sock, struct socket *newsock, int flags,
2766 		   bool kern)
2767 {
2768 	return -EOPNOTSUPP;
2769 }
2770 EXPORT_SYMBOL(sock_no_accept);
2771 
2772 int sock_no_getname(struct socket *sock, struct sockaddr *saddr,
2773 		    int peer)
2774 {
2775 	return -EOPNOTSUPP;
2776 }
2777 EXPORT_SYMBOL(sock_no_getname);
2778 
2779 int sock_no_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
2780 {
2781 	return -EOPNOTSUPP;
2782 }
2783 EXPORT_SYMBOL(sock_no_ioctl);
2784 
2785 int sock_no_listen(struct socket *sock, int backlog)
2786 {
2787 	return -EOPNOTSUPP;
2788 }
2789 EXPORT_SYMBOL(sock_no_listen);
2790 
2791 int sock_no_shutdown(struct socket *sock, int how)
2792 {
2793 	return -EOPNOTSUPP;
2794 }
2795 EXPORT_SYMBOL(sock_no_shutdown);
2796 
2797 int sock_no_sendmsg(struct socket *sock, struct msghdr *m, size_t len)
2798 {
2799 	return -EOPNOTSUPP;
2800 }
2801 EXPORT_SYMBOL(sock_no_sendmsg);
2802 
2803 int sock_no_sendmsg_locked(struct sock *sk, struct msghdr *m, size_t len)
2804 {
2805 	return -EOPNOTSUPP;
2806 }
2807 EXPORT_SYMBOL(sock_no_sendmsg_locked);
2808 
2809 int sock_no_recvmsg(struct socket *sock, struct msghdr *m, size_t len,
2810 		    int flags)
2811 {
2812 	return -EOPNOTSUPP;
2813 }
2814 EXPORT_SYMBOL(sock_no_recvmsg);
2815 
2816 int sock_no_mmap(struct file *file, struct socket *sock, struct vm_area_struct *vma)
2817 {
2818 	/* Mirror missing mmap method error code */
2819 	return -ENODEV;
2820 }
2821 EXPORT_SYMBOL(sock_no_mmap);
2822 
2823 /*
2824  * When a file is received (via SCM_RIGHTS, etc), we must bump the
2825  * various sock-based usage counts.
2826  */
2827 void __receive_sock(struct file *file)
2828 {
2829 	struct socket *sock;
2830 
2831 	sock = sock_from_file(file);
2832 	if (sock) {
2833 		sock_update_netprioidx(&sock->sk->sk_cgrp_data);
2834 		sock_update_classid(&sock->sk->sk_cgrp_data);
2835 	}
2836 }
2837 
2838 ssize_t sock_no_sendpage(struct socket *sock, struct page *page, int offset, size_t size, int flags)
2839 {
2840 	ssize_t res;
2841 	struct msghdr msg = {.msg_flags = flags};
2842 	struct kvec iov;
2843 	char *kaddr = kmap(page);
2844 	iov.iov_base = kaddr + offset;
2845 	iov.iov_len = size;
2846 	res = kernel_sendmsg(sock, &msg, &iov, 1, size);
2847 	kunmap(page);
2848 	return res;
2849 }
2850 EXPORT_SYMBOL(sock_no_sendpage);
2851 
2852 ssize_t sock_no_sendpage_locked(struct sock *sk, struct page *page,
2853 				int offset, size_t size, int flags)
2854 {
2855 	ssize_t res;
2856 	struct msghdr msg = {.msg_flags = flags};
2857 	struct kvec iov;
2858 	char *kaddr = kmap(page);
2859 
2860 	iov.iov_base = kaddr + offset;
2861 	iov.iov_len = size;
2862 	res = kernel_sendmsg_locked(sk, &msg, &iov, 1, size);
2863 	kunmap(page);
2864 	return res;
2865 }
2866 EXPORT_SYMBOL(sock_no_sendpage_locked);
2867 
2868 /*
2869  *	Default Socket Callbacks
2870  */
2871 
2872 static void sock_def_wakeup(struct sock *sk)
2873 {
2874 	struct socket_wq *wq;
2875 
2876 	rcu_read_lock();
2877 	wq = rcu_dereference(sk->sk_wq);
2878 	if (skwq_has_sleeper(wq))
2879 		wake_up_interruptible_all(&wq->wait);
2880 	rcu_read_unlock();
2881 }
2882 
2883 static void sock_def_error_report(struct sock *sk)
2884 {
2885 	struct socket_wq *wq;
2886 
2887 	rcu_read_lock();
2888 	wq = rcu_dereference(sk->sk_wq);
2889 	if (skwq_has_sleeper(wq))
2890 		wake_up_interruptible_poll(&wq->wait, EPOLLERR);
2891 	sk_wake_async(sk, SOCK_WAKE_IO, POLL_ERR);
2892 	rcu_read_unlock();
2893 }
2894 
2895 void sock_def_readable(struct sock *sk)
2896 {
2897 	struct socket_wq *wq;
2898 
2899 	rcu_read_lock();
2900 	wq = rcu_dereference(sk->sk_wq);
2901 	if (skwq_has_sleeper(wq))
2902 		wake_up_interruptible_sync_poll(&wq->wait, EPOLLIN | EPOLLPRI |
2903 						EPOLLRDNORM | EPOLLRDBAND);
2904 	sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
2905 	rcu_read_unlock();
2906 }
2907 
2908 static void sock_def_write_space(struct sock *sk)
2909 {
2910 	struct socket_wq *wq;
2911 
2912 	rcu_read_lock();
2913 
2914 	/* Do not wake up a writer until he can make "significant"
2915 	 * progress.  --DaveM
2916 	 */
2917 	if ((refcount_read(&sk->sk_wmem_alloc) << 1) <= READ_ONCE(sk->sk_sndbuf)) {
2918 		wq = rcu_dereference(sk->sk_wq);
2919 		if (skwq_has_sleeper(wq))
2920 			wake_up_interruptible_sync_poll(&wq->wait, EPOLLOUT |
2921 						EPOLLWRNORM | EPOLLWRBAND);
2922 
2923 		/* Should agree with poll, otherwise some programs break */
2924 		if (sock_writeable(sk))
2925 			sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
2926 	}
2927 
2928 	rcu_read_unlock();
2929 }
2930 
2931 static void sock_def_destruct(struct sock *sk)
2932 {
2933 }
2934 
2935 void sk_send_sigurg(struct sock *sk)
2936 {
2937 	if (sk->sk_socket && sk->sk_socket->file)
2938 		if (send_sigurg(&sk->sk_socket->file->f_owner))
2939 			sk_wake_async(sk, SOCK_WAKE_URG, POLL_PRI);
2940 }
2941 EXPORT_SYMBOL(sk_send_sigurg);
2942 
2943 void sk_reset_timer(struct sock *sk, struct timer_list* timer,
2944 		    unsigned long expires)
2945 {
2946 	if (!mod_timer(timer, expires))
2947 		sock_hold(sk);
2948 }
2949 EXPORT_SYMBOL(sk_reset_timer);
2950 
2951 void sk_stop_timer(struct sock *sk, struct timer_list* timer)
2952 {
2953 	if (del_timer(timer))
2954 		__sock_put(sk);
2955 }
2956 EXPORT_SYMBOL(sk_stop_timer);
2957 
2958 void sk_stop_timer_sync(struct sock *sk, struct timer_list *timer)
2959 {
2960 	if (del_timer_sync(timer))
2961 		__sock_put(sk);
2962 }
2963 EXPORT_SYMBOL(sk_stop_timer_sync);
2964 
2965 void sock_init_data(struct socket *sock, struct sock *sk)
2966 {
2967 	sk_init_common(sk);
2968 	sk->sk_send_head	=	NULL;
2969 
2970 	timer_setup(&sk->sk_timer, NULL, 0);
2971 
2972 	sk->sk_allocation	=	GFP_KERNEL;
2973 	sk->sk_rcvbuf		=	sysctl_rmem_default;
2974 	sk->sk_sndbuf		=	sysctl_wmem_default;
2975 	sk->sk_state		=	TCP_CLOSE;
2976 	sk_set_socket(sk, sock);
2977 
2978 	sock_set_flag(sk, SOCK_ZAPPED);
2979 
2980 	if (sock) {
2981 		sk->sk_type	=	sock->type;
2982 		RCU_INIT_POINTER(sk->sk_wq, &sock->wq);
2983 		sock->sk	=	sk;
2984 		sk->sk_uid	=	SOCK_INODE(sock)->i_uid;
2985 	} else {
2986 		RCU_INIT_POINTER(sk->sk_wq, NULL);
2987 		sk->sk_uid	=	make_kuid(sock_net(sk)->user_ns, 0);
2988 	}
2989 
2990 	rwlock_init(&sk->sk_callback_lock);
2991 	if (sk->sk_kern_sock)
2992 		lockdep_set_class_and_name(
2993 			&sk->sk_callback_lock,
2994 			af_kern_callback_keys + sk->sk_family,
2995 			af_family_kern_clock_key_strings[sk->sk_family]);
2996 	else
2997 		lockdep_set_class_and_name(
2998 			&sk->sk_callback_lock,
2999 			af_callback_keys + sk->sk_family,
3000 			af_family_clock_key_strings[sk->sk_family]);
3001 
3002 	sk->sk_state_change	=	sock_def_wakeup;
3003 	sk->sk_data_ready	=	sock_def_readable;
3004 	sk->sk_write_space	=	sock_def_write_space;
3005 	sk->sk_error_report	=	sock_def_error_report;
3006 	sk->sk_destruct		=	sock_def_destruct;
3007 
3008 	sk->sk_frag.page	=	NULL;
3009 	sk->sk_frag.offset	=	0;
3010 	sk->sk_peek_off		=	-1;
3011 
3012 	sk->sk_peer_pid 	=	NULL;
3013 	sk->sk_peer_cred	=	NULL;
3014 	sk->sk_write_pending	=	0;
3015 	sk->sk_rcvlowat		=	1;
3016 	sk->sk_rcvtimeo		=	MAX_SCHEDULE_TIMEOUT;
3017 	sk->sk_sndtimeo		=	MAX_SCHEDULE_TIMEOUT;
3018 
3019 	sk->sk_stamp = SK_DEFAULT_STAMP;
3020 #if BITS_PER_LONG==32
3021 	seqlock_init(&sk->sk_stamp_seq);
3022 #endif
3023 	atomic_set(&sk->sk_zckey, 0);
3024 
3025 #ifdef CONFIG_NET_RX_BUSY_POLL
3026 	sk->sk_napi_id		=	0;
3027 	sk->sk_ll_usec		=	sysctl_net_busy_read;
3028 #endif
3029 
3030 	sk->sk_max_pacing_rate = ~0UL;
3031 	sk->sk_pacing_rate = ~0UL;
3032 	WRITE_ONCE(sk->sk_pacing_shift, 10);
3033 	sk->sk_incoming_cpu = -1;
3034 
3035 	sk_rx_queue_clear(sk);
3036 	/*
3037 	 * Before updating sk_refcnt, we must commit prior changes to memory
3038 	 * (Documentation/RCU/rculist_nulls.rst for details)
3039 	 */
3040 	smp_wmb();
3041 	refcount_set(&sk->sk_refcnt, 1);
3042 	atomic_set(&sk->sk_drops, 0);
3043 }
3044 EXPORT_SYMBOL(sock_init_data);
3045 
3046 void lock_sock_nested(struct sock *sk, int subclass)
3047 {
3048 	might_sleep();
3049 	spin_lock_bh(&sk->sk_lock.slock);
3050 	if (sk->sk_lock.owned)
3051 		__lock_sock(sk);
3052 	sk->sk_lock.owned = 1;
3053 	spin_unlock(&sk->sk_lock.slock);
3054 	/*
3055 	 * The sk_lock has mutex_lock() semantics here:
3056 	 */
3057 	mutex_acquire(&sk->sk_lock.dep_map, subclass, 0, _RET_IP_);
3058 	local_bh_enable();
3059 }
3060 EXPORT_SYMBOL(lock_sock_nested);
3061 
3062 void release_sock(struct sock *sk)
3063 {
3064 	spin_lock_bh(&sk->sk_lock.slock);
3065 	if (sk->sk_backlog.tail)
3066 		__release_sock(sk);
3067 
3068 	/* Warning : release_cb() might need to release sk ownership,
3069 	 * ie call sock_release_ownership(sk) before us.
3070 	 */
3071 	if (sk->sk_prot->release_cb)
3072 		sk->sk_prot->release_cb(sk);
3073 
3074 	sock_release_ownership(sk);
3075 	if (waitqueue_active(&sk->sk_lock.wq))
3076 		wake_up(&sk->sk_lock.wq);
3077 	spin_unlock_bh(&sk->sk_lock.slock);
3078 }
3079 EXPORT_SYMBOL(release_sock);
3080 
3081 /**
3082  * lock_sock_fast - fast version of lock_sock
3083  * @sk: socket
3084  *
3085  * This version should be used for very small section, where process wont block
3086  * return false if fast path is taken:
3087  *
3088  *   sk_lock.slock locked, owned = 0, BH disabled
3089  *
3090  * return true if slow path is taken:
3091  *
3092  *   sk_lock.slock unlocked, owned = 1, BH enabled
3093  */
3094 bool lock_sock_fast(struct sock *sk) __acquires(&sk->sk_lock.slock)
3095 {
3096 	might_sleep();
3097 	spin_lock_bh(&sk->sk_lock.slock);
3098 
3099 	if (!sk->sk_lock.owned)
3100 		/*
3101 		 * Note : We must disable BH
3102 		 */
3103 		return false;
3104 
3105 	__lock_sock(sk);
3106 	sk->sk_lock.owned = 1;
3107 	spin_unlock(&sk->sk_lock.slock);
3108 	/*
3109 	 * The sk_lock has mutex_lock() semantics here:
3110 	 */
3111 	mutex_acquire(&sk->sk_lock.dep_map, 0, 0, _RET_IP_);
3112 	__acquire(&sk->sk_lock.slock);
3113 	local_bh_enable();
3114 	return true;
3115 }
3116 EXPORT_SYMBOL(lock_sock_fast);
3117 
3118 int sock_gettstamp(struct socket *sock, void __user *userstamp,
3119 		   bool timeval, bool time32)
3120 {
3121 	struct sock *sk = sock->sk;
3122 	struct timespec64 ts;
3123 
3124 	sock_enable_timestamp(sk, SOCK_TIMESTAMP);
3125 	ts = ktime_to_timespec64(sock_read_timestamp(sk));
3126 	if (ts.tv_sec == -1)
3127 		return -ENOENT;
3128 	if (ts.tv_sec == 0) {
3129 		ktime_t kt = ktime_get_real();
3130 		sock_write_timestamp(sk, kt);
3131 		ts = ktime_to_timespec64(kt);
3132 	}
3133 
3134 	if (timeval)
3135 		ts.tv_nsec /= 1000;
3136 
3137 #ifdef CONFIG_COMPAT_32BIT_TIME
3138 	if (time32)
3139 		return put_old_timespec32(&ts, userstamp);
3140 #endif
3141 #ifdef CONFIG_SPARC64
3142 	/* beware of padding in sparc64 timeval */
3143 	if (timeval && !in_compat_syscall()) {
3144 		struct __kernel_old_timeval __user tv = {
3145 			.tv_sec = ts.tv_sec,
3146 			.tv_usec = ts.tv_nsec,
3147 		};
3148 		if (copy_to_user(userstamp, &tv, sizeof(tv)))
3149 			return -EFAULT;
3150 		return 0;
3151 	}
3152 #endif
3153 	return put_timespec64(&ts, userstamp);
3154 }
3155 EXPORT_SYMBOL(sock_gettstamp);
3156 
3157 void sock_enable_timestamp(struct sock *sk, enum sock_flags flag)
3158 {
3159 	if (!sock_flag(sk, flag)) {
3160 		unsigned long previous_flags = sk->sk_flags;
3161 
3162 		sock_set_flag(sk, flag);
3163 		/*
3164 		 * we just set one of the two flags which require net
3165 		 * time stamping, but time stamping might have been on
3166 		 * already because of the other one
3167 		 */
3168 		if (sock_needs_netstamp(sk) &&
3169 		    !(previous_flags & SK_FLAGS_TIMESTAMP))
3170 			net_enable_timestamp();
3171 	}
3172 }
3173 
3174 int sock_recv_errqueue(struct sock *sk, struct msghdr *msg, int len,
3175 		       int level, int type)
3176 {
3177 	struct sock_exterr_skb *serr;
3178 	struct sk_buff *skb;
3179 	int copied, err;
3180 
3181 	err = -EAGAIN;
3182 	skb = sock_dequeue_err_skb(sk);
3183 	if (skb == NULL)
3184 		goto out;
3185 
3186 	copied = skb->len;
3187 	if (copied > len) {
3188 		msg->msg_flags |= MSG_TRUNC;
3189 		copied = len;
3190 	}
3191 	err = skb_copy_datagram_msg(skb, 0, msg, copied);
3192 	if (err)
3193 		goto out_free_skb;
3194 
3195 	sock_recv_timestamp(msg, sk, skb);
3196 
3197 	serr = SKB_EXT_ERR(skb);
3198 	put_cmsg(msg, level, type, sizeof(serr->ee), &serr->ee);
3199 
3200 	msg->msg_flags |= MSG_ERRQUEUE;
3201 	err = copied;
3202 
3203 out_free_skb:
3204 	kfree_skb(skb);
3205 out:
3206 	return err;
3207 }
3208 EXPORT_SYMBOL(sock_recv_errqueue);
3209 
3210 /*
3211  *	Get a socket option on an socket.
3212  *
3213  *	FIX: POSIX 1003.1g is very ambiguous here. It states that
3214  *	asynchronous errors should be reported by getsockopt. We assume
3215  *	this means if you specify SO_ERROR (otherwise whats the point of it).
3216  */
3217 int sock_common_getsockopt(struct socket *sock, int level, int optname,
3218 			   char __user *optval, int __user *optlen)
3219 {
3220 	struct sock *sk = sock->sk;
3221 
3222 	return sk->sk_prot->getsockopt(sk, level, optname, optval, optlen);
3223 }
3224 EXPORT_SYMBOL(sock_common_getsockopt);
3225 
3226 int sock_common_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
3227 			int flags)
3228 {
3229 	struct sock *sk = sock->sk;
3230 	int addr_len = 0;
3231 	int err;
3232 
3233 	err = sk->sk_prot->recvmsg(sk, msg, size, flags & MSG_DONTWAIT,
3234 				   flags & ~MSG_DONTWAIT, &addr_len);
3235 	if (err >= 0)
3236 		msg->msg_namelen = addr_len;
3237 	return err;
3238 }
3239 EXPORT_SYMBOL(sock_common_recvmsg);
3240 
3241 /*
3242  *	Set socket options on an inet socket.
3243  */
3244 int sock_common_setsockopt(struct socket *sock, int level, int optname,
3245 			   sockptr_t optval, unsigned int optlen)
3246 {
3247 	struct sock *sk = sock->sk;
3248 
3249 	return sk->sk_prot->setsockopt(sk, level, optname, optval, optlen);
3250 }
3251 EXPORT_SYMBOL(sock_common_setsockopt);
3252 
3253 void sk_common_release(struct sock *sk)
3254 {
3255 	if (sk->sk_prot->destroy)
3256 		sk->sk_prot->destroy(sk);
3257 
3258 	/*
3259 	 * Observation: when sk_common_release is called, processes have
3260 	 * no access to socket. But net still has.
3261 	 * Step one, detach it from networking:
3262 	 *
3263 	 * A. Remove from hash tables.
3264 	 */
3265 
3266 	sk->sk_prot->unhash(sk);
3267 
3268 	/*
3269 	 * In this point socket cannot receive new packets, but it is possible
3270 	 * that some packets are in flight because some CPU runs receiver and
3271 	 * did hash table lookup before we unhashed socket. They will achieve
3272 	 * receive queue and will be purged by socket destructor.
3273 	 *
3274 	 * Also we still have packets pending on receive queue and probably,
3275 	 * our own packets waiting in device queues. sock_destroy will drain
3276 	 * receive queue, but transmitted packets will delay socket destruction
3277 	 * until the last reference will be released.
3278 	 */
3279 
3280 	sock_orphan(sk);
3281 
3282 	xfrm_sk_free_policy(sk);
3283 
3284 	sk_refcnt_debug_release(sk);
3285 
3286 	sock_put(sk);
3287 }
3288 EXPORT_SYMBOL(sk_common_release);
3289 
3290 void sk_get_meminfo(const struct sock *sk, u32 *mem)
3291 {
3292 	memset(mem, 0, sizeof(*mem) * SK_MEMINFO_VARS);
3293 
3294 	mem[SK_MEMINFO_RMEM_ALLOC] = sk_rmem_alloc_get(sk);
3295 	mem[SK_MEMINFO_RCVBUF] = READ_ONCE(sk->sk_rcvbuf);
3296 	mem[SK_MEMINFO_WMEM_ALLOC] = sk_wmem_alloc_get(sk);
3297 	mem[SK_MEMINFO_SNDBUF] = READ_ONCE(sk->sk_sndbuf);
3298 	mem[SK_MEMINFO_FWD_ALLOC] = sk->sk_forward_alloc;
3299 	mem[SK_MEMINFO_WMEM_QUEUED] = READ_ONCE(sk->sk_wmem_queued);
3300 	mem[SK_MEMINFO_OPTMEM] = atomic_read(&sk->sk_omem_alloc);
3301 	mem[SK_MEMINFO_BACKLOG] = READ_ONCE(sk->sk_backlog.len);
3302 	mem[SK_MEMINFO_DROPS] = atomic_read(&sk->sk_drops);
3303 }
3304 
3305 #ifdef CONFIG_PROC_FS
3306 #define PROTO_INUSE_NR	64	/* should be enough for the first time */
3307 struct prot_inuse {
3308 	int val[PROTO_INUSE_NR];
3309 };
3310 
3311 static DECLARE_BITMAP(proto_inuse_idx, PROTO_INUSE_NR);
3312 
3313 void sock_prot_inuse_add(struct net *net, struct proto *prot, int val)
3314 {
3315 	__this_cpu_add(net->core.prot_inuse->val[prot->inuse_idx], val);
3316 }
3317 EXPORT_SYMBOL_GPL(sock_prot_inuse_add);
3318 
3319 int sock_prot_inuse_get(struct net *net, struct proto *prot)
3320 {
3321 	int cpu, idx = prot->inuse_idx;
3322 	int res = 0;
3323 
3324 	for_each_possible_cpu(cpu)
3325 		res += per_cpu_ptr(net->core.prot_inuse, cpu)->val[idx];
3326 
3327 	return res >= 0 ? res : 0;
3328 }
3329 EXPORT_SYMBOL_GPL(sock_prot_inuse_get);
3330 
3331 static void sock_inuse_add(struct net *net, int val)
3332 {
3333 	this_cpu_add(*net->core.sock_inuse, val);
3334 }
3335 
3336 int sock_inuse_get(struct net *net)
3337 {
3338 	int cpu, res = 0;
3339 
3340 	for_each_possible_cpu(cpu)
3341 		res += *per_cpu_ptr(net->core.sock_inuse, cpu);
3342 
3343 	return res;
3344 }
3345 
3346 EXPORT_SYMBOL_GPL(sock_inuse_get);
3347 
3348 static int __net_init sock_inuse_init_net(struct net *net)
3349 {
3350 	net->core.prot_inuse = alloc_percpu(struct prot_inuse);
3351 	if (net->core.prot_inuse == NULL)
3352 		return -ENOMEM;
3353 
3354 	net->core.sock_inuse = alloc_percpu(int);
3355 	if (net->core.sock_inuse == NULL)
3356 		goto out;
3357 
3358 	return 0;
3359 
3360 out:
3361 	free_percpu(net->core.prot_inuse);
3362 	return -ENOMEM;
3363 }
3364 
3365 static void __net_exit sock_inuse_exit_net(struct net *net)
3366 {
3367 	free_percpu(net->core.prot_inuse);
3368 	free_percpu(net->core.sock_inuse);
3369 }
3370 
3371 static struct pernet_operations net_inuse_ops = {
3372 	.init = sock_inuse_init_net,
3373 	.exit = sock_inuse_exit_net,
3374 };
3375 
3376 static __init int net_inuse_init(void)
3377 {
3378 	if (register_pernet_subsys(&net_inuse_ops))
3379 		panic("Cannot initialize net inuse counters");
3380 
3381 	return 0;
3382 }
3383 
3384 core_initcall(net_inuse_init);
3385 
3386 static int assign_proto_idx(struct proto *prot)
3387 {
3388 	prot->inuse_idx = find_first_zero_bit(proto_inuse_idx, PROTO_INUSE_NR);
3389 
3390 	if (unlikely(prot->inuse_idx == PROTO_INUSE_NR - 1)) {
3391 		pr_err("PROTO_INUSE_NR exhausted\n");
3392 		return -ENOSPC;
3393 	}
3394 
3395 	set_bit(prot->inuse_idx, proto_inuse_idx);
3396 	return 0;
3397 }
3398 
3399 static void release_proto_idx(struct proto *prot)
3400 {
3401 	if (prot->inuse_idx != PROTO_INUSE_NR - 1)
3402 		clear_bit(prot->inuse_idx, proto_inuse_idx);
3403 }
3404 #else
3405 static inline int assign_proto_idx(struct proto *prot)
3406 {
3407 	return 0;
3408 }
3409 
3410 static inline void release_proto_idx(struct proto *prot)
3411 {
3412 }
3413 
3414 static void sock_inuse_add(struct net *net, int val)
3415 {
3416 }
3417 #endif
3418 
3419 static void tw_prot_cleanup(struct timewait_sock_ops *twsk_prot)
3420 {
3421 	if (!twsk_prot)
3422 		return;
3423 	kfree(twsk_prot->twsk_slab_name);
3424 	twsk_prot->twsk_slab_name = NULL;
3425 	kmem_cache_destroy(twsk_prot->twsk_slab);
3426 	twsk_prot->twsk_slab = NULL;
3427 }
3428 
3429 static void req_prot_cleanup(struct request_sock_ops *rsk_prot)
3430 {
3431 	if (!rsk_prot)
3432 		return;
3433 	kfree(rsk_prot->slab_name);
3434 	rsk_prot->slab_name = NULL;
3435 	kmem_cache_destroy(rsk_prot->slab);
3436 	rsk_prot->slab = NULL;
3437 }
3438 
3439 static int req_prot_init(const struct proto *prot)
3440 {
3441 	struct request_sock_ops *rsk_prot = prot->rsk_prot;
3442 
3443 	if (!rsk_prot)
3444 		return 0;
3445 
3446 	rsk_prot->slab_name = kasprintf(GFP_KERNEL, "request_sock_%s",
3447 					prot->name);
3448 	if (!rsk_prot->slab_name)
3449 		return -ENOMEM;
3450 
3451 	rsk_prot->slab = kmem_cache_create(rsk_prot->slab_name,
3452 					   rsk_prot->obj_size, 0,
3453 					   SLAB_ACCOUNT | prot->slab_flags,
3454 					   NULL);
3455 
3456 	if (!rsk_prot->slab) {
3457 		pr_crit("%s: Can't create request sock SLAB cache!\n",
3458 			prot->name);
3459 		return -ENOMEM;
3460 	}
3461 	return 0;
3462 }
3463 
3464 int proto_register(struct proto *prot, int alloc_slab)
3465 {
3466 	int ret = -ENOBUFS;
3467 
3468 	if (alloc_slab) {
3469 		prot->slab = kmem_cache_create_usercopy(prot->name,
3470 					prot->obj_size, 0,
3471 					SLAB_HWCACHE_ALIGN | SLAB_ACCOUNT |
3472 					prot->slab_flags,
3473 					prot->useroffset, prot->usersize,
3474 					NULL);
3475 
3476 		if (prot->slab == NULL) {
3477 			pr_crit("%s: Can't create sock SLAB cache!\n",
3478 				prot->name);
3479 			goto out;
3480 		}
3481 
3482 		if (req_prot_init(prot))
3483 			goto out_free_request_sock_slab;
3484 
3485 		if (prot->twsk_prot != NULL) {
3486 			prot->twsk_prot->twsk_slab_name = kasprintf(GFP_KERNEL, "tw_sock_%s", prot->name);
3487 
3488 			if (prot->twsk_prot->twsk_slab_name == NULL)
3489 				goto out_free_request_sock_slab;
3490 
3491 			prot->twsk_prot->twsk_slab =
3492 				kmem_cache_create(prot->twsk_prot->twsk_slab_name,
3493 						  prot->twsk_prot->twsk_obj_size,
3494 						  0,
3495 						  SLAB_ACCOUNT |
3496 						  prot->slab_flags,
3497 						  NULL);
3498 			if (prot->twsk_prot->twsk_slab == NULL)
3499 				goto out_free_timewait_sock_slab;
3500 		}
3501 	}
3502 
3503 	mutex_lock(&proto_list_mutex);
3504 	ret = assign_proto_idx(prot);
3505 	if (ret) {
3506 		mutex_unlock(&proto_list_mutex);
3507 		goto out_free_timewait_sock_slab;
3508 	}
3509 	list_add(&prot->node, &proto_list);
3510 	mutex_unlock(&proto_list_mutex);
3511 	return ret;
3512 
3513 out_free_timewait_sock_slab:
3514 	if (alloc_slab && prot->twsk_prot)
3515 		tw_prot_cleanup(prot->twsk_prot);
3516 out_free_request_sock_slab:
3517 	if (alloc_slab) {
3518 		req_prot_cleanup(prot->rsk_prot);
3519 
3520 		kmem_cache_destroy(prot->slab);
3521 		prot->slab = NULL;
3522 	}
3523 out:
3524 	return ret;
3525 }
3526 EXPORT_SYMBOL(proto_register);
3527 
3528 void proto_unregister(struct proto *prot)
3529 {
3530 	mutex_lock(&proto_list_mutex);
3531 	release_proto_idx(prot);
3532 	list_del(&prot->node);
3533 	mutex_unlock(&proto_list_mutex);
3534 
3535 	kmem_cache_destroy(prot->slab);
3536 	prot->slab = NULL;
3537 
3538 	req_prot_cleanup(prot->rsk_prot);
3539 	tw_prot_cleanup(prot->twsk_prot);
3540 }
3541 EXPORT_SYMBOL(proto_unregister);
3542 
3543 int sock_load_diag_module(int family, int protocol)
3544 {
3545 	if (!protocol) {
3546 		if (!sock_is_registered(family))
3547 			return -ENOENT;
3548 
3549 		return request_module("net-pf-%d-proto-%d-type-%d", PF_NETLINK,
3550 				      NETLINK_SOCK_DIAG, family);
3551 	}
3552 
3553 #ifdef CONFIG_INET
3554 	if (family == AF_INET &&
3555 	    protocol != IPPROTO_RAW &&
3556 	    protocol < MAX_INET_PROTOS &&
3557 	    !rcu_access_pointer(inet_protos[protocol]))
3558 		return -ENOENT;
3559 #endif
3560 
3561 	return request_module("net-pf-%d-proto-%d-type-%d-%d", PF_NETLINK,
3562 			      NETLINK_SOCK_DIAG, family, protocol);
3563 }
3564 EXPORT_SYMBOL(sock_load_diag_module);
3565 
3566 #ifdef CONFIG_PROC_FS
3567 static void *proto_seq_start(struct seq_file *seq, loff_t *pos)
3568 	__acquires(proto_list_mutex)
3569 {
3570 	mutex_lock(&proto_list_mutex);
3571 	return seq_list_start_head(&proto_list, *pos);
3572 }
3573 
3574 static void *proto_seq_next(struct seq_file *seq, void *v, loff_t *pos)
3575 {
3576 	return seq_list_next(v, &proto_list, pos);
3577 }
3578 
3579 static void proto_seq_stop(struct seq_file *seq, void *v)
3580 	__releases(proto_list_mutex)
3581 {
3582 	mutex_unlock(&proto_list_mutex);
3583 }
3584 
3585 static char proto_method_implemented(const void *method)
3586 {
3587 	return method == NULL ? 'n' : 'y';
3588 }
3589 static long sock_prot_memory_allocated(struct proto *proto)
3590 {
3591 	return proto->memory_allocated != NULL ? proto_memory_allocated(proto) : -1L;
3592 }
3593 
3594 static const char *sock_prot_memory_pressure(struct proto *proto)
3595 {
3596 	return proto->memory_pressure != NULL ?
3597 	proto_memory_pressure(proto) ? "yes" : "no" : "NI";
3598 }
3599 
3600 static void proto_seq_printf(struct seq_file *seq, struct proto *proto)
3601 {
3602 
3603 	seq_printf(seq, "%-9s %4u %6d  %6ld   %-3s %6u   %-3s  %-10s "
3604 			"%2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c\n",
3605 		   proto->name,
3606 		   proto->obj_size,
3607 		   sock_prot_inuse_get(seq_file_net(seq), proto),
3608 		   sock_prot_memory_allocated(proto),
3609 		   sock_prot_memory_pressure(proto),
3610 		   proto->max_header,
3611 		   proto->slab == NULL ? "no" : "yes",
3612 		   module_name(proto->owner),
3613 		   proto_method_implemented(proto->close),
3614 		   proto_method_implemented(proto->connect),
3615 		   proto_method_implemented(proto->disconnect),
3616 		   proto_method_implemented(proto->accept),
3617 		   proto_method_implemented(proto->ioctl),
3618 		   proto_method_implemented(proto->init),
3619 		   proto_method_implemented(proto->destroy),
3620 		   proto_method_implemented(proto->shutdown),
3621 		   proto_method_implemented(proto->setsockopt),
3622 		   proto_method_implemented(proto->getsockopt),
3623 		   proto_method_implemented(proto->sendmsg),
3624 		   proto_method_implemented(proto->recvmsg),
3625 		   proto_method_implemented(proto->sendpage),
3626 		   proto_method_implemented(proto->bind),
3627 		   proto_method_implemented(proto->backlog_rcv),
3628 		   proto_method_implemented(proto->hash),
3629 		   proto_method_implemented(proto->unhash),
3630 		   proto_method_implemented(proto->get_port),
3631 		   proto_method_implemented(proto->enter_memory_pressure));
3632 }
3633 
3634 static int proto_seq_show(struct seq_file *seq, void *v)
3635 {
3636 	if (v == &proto_list)
3637 		seq_printf(seq, "%-9s %-4s %-8s %-6s %-5s %-7s %-4s %-10s %s",
3638 			   "protocol",
3639 			   "size",
3640 			   "sockets",
3641 			   "memory",
3642 			   "press",
3643 			   "maxhdr",
3644 			   "slab",
3645 			   "module",
3646 			   "cl co di ac io in de sh ss gs se re sp bi br ha uh gp em\n");
3647 	else
3648 		proto_seq_printf(seq, list_entry(v, struct proto, node));
3649 	return 0;
3650 }
3651 
3652 static const struct seq_operations proto_seq_ops = {
3653 	.start  = proto_seq_start,
3654 	.next   = proto_seq_next,
3655 	.stop   = proto_seq_stop,
3656 	.show   = proto_seq_show,
3657 };
3658 
3659 static __net_init int proto_init_net(struct net *net)
3660 {
3661 	if (!proc_create_net("protocols", 0444, net->proc_net, &proto_seq_ops,
3662 			sizeof(struct seq_net_private)))
3663 		return -ENOMEM;
3664 
3665 	return 0;
3666 }
3667 
3668 static __net_exit void proto_exit_net(struct net *net)
3669 {
3670 	remove_proc_entry("protocols", net->proc_net);
3671 }
3672 
3673 
3674 static __net_initdata struct pernet_operations proto_net_ops = {
3675 	.init = proto_init_net,
3676 	.exit = proto_exit_net,
3677 };
3678 
3679 static int __init proto_init(void)
3680 {
3681 	return register_pernet_subsys(&proto_net_ops);
3682 }
3683 
3684 subsys_initcall(proto_init);
3685 
3686 #endif /* PROC_FS */
3687 
3688 #ifdef CONFIG_NET_RX_BUSY_POLL
3689 bool sk_busy_loop_end(void *p, unsigned long start_time)
3690 {
3691 	struct sock *sk = p;
3692 
3693 	return !skb_queue_empty_lockless(&sk->sk_receive_queue) ||
3694 	       sk_busy_loop_timeout(sk, start_time);
3695 }
3696 EXPORT_SYMBOL(sk_busy_loop_end);
3697 #endif /* CONFIG_NET_RX_BUSY_POLL */
3698 
3699 int sock_bind_add(struct sock *sk, struct sockaddr *addr, int addr_len)
3700 {
3701 	if (!sk->sk_prot->bind_add)
3702 		return -EOPNOTSUPP;
3703 	return sk->sk_prot->bind_add(sk, addr, addr_len);
3704 }
3705 EXPORT_SYMBOL(sock_bind_add);
3706