xref: /linux/net/core/sock.c (revision 58b3bafff8257c6946df5d6aeb215b8ac839ed2a)
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 
117 #include <linux/uaccess.h>
118 
119 #include <linux/netdevice.h>
120 #include <net/protocol.h>
121 #include <linux/skbuff.h>
122 #include <net/net_namespace.h>
123 #include <net/request_sock.h>
124 #include <net/sock.h>
125 #include <linux/net_tstamp.h>
126 #include <net/xfrm.h>
127 #include <linux/ipsec.h>
128 #include <net/cls_cgroup.h>
129 #include <net/netprio_cgroup.h>
130 #include <linux/sock_diag.h>
131 
132 #include <linux/filter.h>
133 #include <net/sock_reuseport.h>
134 #include <net/bpf_sk_storage.h>
135 
136 #include <trace/events/sock.h>
137 
138 #include <net/tcp.h>
139 #include <net/busy_poll.h>
140 
141 static DEFINE_MUTEX(proto_list_mutex);
142 static LIST_HEAD(proto_list);
143 
144 static void sock_inuse_add(struct net *net, int val);
145 
146 /**
147  * sk_ns_capable - General socket capability test
148  * @sk: Socket to use a capability on or through
149  * @user_ns: The user namespace of the capability to use
150  * @cap: The capability to use
151  *
152  * Test to see if the opener of the socket had when the socket was
153  * created and the current process has the capability @cap in the user
154  * namespace @user_ns.
155  */
156 bool sk_ns_capable(const struct sock *sk,
157 		   struct user_namespace *user_ns, int cap)
158 {
159 	return file_ns_capable(sk->sk_socket->file, user_ns, cap) &&
160 		ns_capable(user_ns, cap);
161 }
162 EXPORT_SYMBOL(sk_ns_capable);
163 
164 /**
165  * sk_capable - Socket global capability test
166  * @sk: Socket to use a capability on or through
167  * @cap: The global capability to use
168  *
169  * Test to see if the opener of the socket had when the socket was
170  * created and the current process has the capability @cap in all user
171  * namespaces.
172  */
173 bool sk_capable(const struct sock *sk, int cap)
174 {
175 	return sk_ns_capable(sk, &init_user_ns, cap);
176 }
177 EXPORT_SYMBOL(sk_capable);
178 
179 /**
180  * sk_net_capable - Network namespace socket capability test
181  * @sk: Socket to use a capability on or through
182  * @cap: The capability to use
183  *
184  * Test to see if the opener of the socket had when the socket was created
185  * and the current process has the capability @cap over the network namespace
186  * the socket is a member of.
187  */
188 bool sk_net_capable(const struct sock *sk, int cap)
189 {
190 	return sk_ns_capable(sk, sock_net(sk)->user_ns, cap);
191 }
192 EXPORT_SYMBOL(sk_net_capable);
193 
194 /*
195  * Each address family might have different locking rules, so we have
196  * one slock key per address family and separate keys for internal and
197  * userspace sockets.
198  */
199 static struct lock_class_key af_family_keys[AF_MAX];
200 static struct lock_class_key af_family_kern_keys[AF_MAX];
201 static struct lock_class_key af_family_slock_keys[AF_MAX];
202 static struct lock_class_key af_family_kern_slock_keys[AF_MAX];
203 
204 /*
205  * Make lock validator output more readable. (we pre-construct these
206  * strings build-time, so that runtime initialization of socket
207  * locks is fast):
208  */
209 
210 #define _sock_locks(x)						  \
211   x "AF_UNSPEC",	x "AF_UNIX"     ,	x "AF_INET"     , \
212   x "AF_AX25"  ,	x "AF_IPX"      ,	x "AF_APPLETALK", \
213   x "AF_NETROM",	x "AF_BRIDGE"   ,	x "AF_ATMPVC"   , \
214   x "AF_X25"   ,	x "AF_INET6"    ,	x "AF_ROSE"     , \
215   x "AF_DECnet",	x "AF_NETBEUI"  ,	x "AF_SECURITY" , \
216   x "AF_KEY"   ,	x "AF_NETLINK"  ,	x "AF_PACKET"   , \
217   x "AF_ASH"   ,	x "AF_ECONET"   ,	x "AF_ATMSVC"   , \
218   x "AF_RDS"   ,	x "AF_SNA"      ,	x "AF_IRDA"     , \
219   x "AF_PPPOX" ,	x "AF_WANPIPE"  ,	x "AF_LLC"      , \
220   x "27"       ,	x "28"          ,	x "AF_CAN"      , \
221   x "AF_TIPC"  ,	x "AF_BLUETOOTH",	x "IUCV"        , \
222   x "AF_RXRPC" ,	x "AF_ISDN"     ,	x "AF_PHONET"   , \
223   x "AF_IEEE802154",	x "AF_CAIF"	,	x "AF_ALG"      , \
224   x "AF_NFC"   ,	x "AF_VSOCK"    ,	x "AF_KCM"      , \
225   x "AF_QIPCRTR",	x "AF_SMC"	,	x "AF_XDP"	, \
226   x "AF_MAX"
227 
228 static const char *const af_family_key_strings[AF_MAX+1] = {
229 	_sock_locks("sk_lock-")
230 };
231 static const char *const af_family_slock_key_strings[AF_MAX+1] = {
232 	_sock_locks("slock-")
233 };
234 static const char *const af_family_clock_key_strings[AF_MAX+1] = {
235 	_sock_locks("clock-")
236 };
237 
238 static const char *const af_family_kern_key_strings[AF_MAX+1] = {
239 	_sock_locks("k-sk_lock-")
240 };
241 static const char *const af_family_kern_slock_key_strings[AF_MAX+1] = {
242 	_sock_locks("k-slock-")
243 };
244 static const char *const af_family_kern_clock_key_strings[AF_MAX+1] = {
245 	_sock_locks("k-clock-")
246 };
247 static const char *const af_family_rlock_key_strings[AF_MAX+1] = {
248 	_sock_locks("rlock-")
249 };
250 static const char *const af_family_wlock_key_strings[AF_MAX+1] = {
251 	_sock_locks("wlock-")
252 };
253 static const char *const af_family_elock_key_strings[AF_MAX+1] = {
254 	_sock_locks("elock-")
255 };
256 
257 /*
258  * sk_callback_lock and sk queues locking rules are per-address-family,
259  * so split the lock classes by using a per-AF key:
260  */
261 static struct lock_class_key af_callback_keys[AF_MAX];
262 static struct lock_class_key af_rlock_keys[AF_MAX];
263 static struct lock_class_key af_wlock_keys[AF_MAX];
264 static struct lock_class_key af_elock_keys[AF_MAX];
265 static struct lock_class_key af_kern_callback_keys[AF_MAX];
266 
267 /* Run time adjustable parameters. */
268 __u32 sysctl_wmem_max __read_mostly = SK_WMEM_MAX;
269 EXPORT_SYMBOL(sysctl_wmem_max);
270 __u32 sysctl_rmem_max __read_mostly = SK_RMEM_MAX;
271 EXPORT_SYMBOL(sysctl_rmem_max);
272 __u32 sysctl_wmem_default __read_mostly = SK_WMEM_MAX;
273 __u32 sysctl_rmem_default __read_mostly = SK_RMEM_MAX;
274 
275 /* Maximal space eaten by iovec or ancillary data plus some space */
276 int sysctl_optmem_max __read_mostly = sizeof(unsigned long)*(2*UIO_MAXIOV+512);
277 EXPORT_SYMBOL(sysctl_optmem_max);
278 
279 int sysctl_tstamp_allow_data __read_mostly = 1;
280 
281 DEFINE_STATIC_KEY_FALSE(memalloc_socks_key);
282 EXPORT_SYMBOL_GPL(memalloc_socks_key);
283 
284 /**
285  * sk_set_memalloc - sets %SOCK_MEMALLOC
286  * @sk: socket to set it on
287  *
288  * Set %SOCK_MEMALLOC on a socket for access to emergency reserves.
289  * It's the responsibility of the admin to adjust min_free_kbytes
290  * to meet the requirements
291  */
292 void sk_set_memalloc(struct sock *sk)
293 {
294 	sock_set_flag(sk, SOCK_MEMALLOC);
295 	sk->sk_allocation |= __GFP_MEMALLOC;
296 	static_branch_inc(&memalloc_socks_key);
297 }
298 EXPORT_SYMBOL_GPL(sk_set_memalloc);
299 
300 void sk_clear_memalloc(struct sock *sk)
301 {
302 	sock_reset_flag(sk, SOCK_MEMALLOC);
303 	sk->sk_allocation &= ~__GFP_MEMALLOC;
304 	static_branch_dec(&memalloc_socks_key);
305 
306 	/*
307 	 * SOCK_MEMALLOC is allowed to ignore rmem limits to ensure forward
308 	 * progress of swapping. SOCK_MEMALLOC may be cleared while
309 	 * it has rmem allocations due to the last swapfile being deactivated
310 	 * but there is a risk that the socket is unusable due to exceeding
311 	 * the rmem limits. Reclaim the reserves and obey rmem limits again.
312 	 */
313 	sk_mem_reclaim(sk);
314 }
315 EXPORT_SYMBOL_GPL(sk_clear_memalloc);
316 
317 int __sk_backlog_rcv(struct sock *sk, struct sk_buff *skb)
318 {
319 	int ret;
320 	unsigned int noreclaim_flag;
321 
322 	/* these should have been dropped before queueing */
323 	BUG_ON(!sock_flag(sk, SOCK_MEMALLOC));
324 
325 	noreclaim_flag = memalloc_noreclaim_save();
326 	ret = sk->sk_backlog_rcv(sk, skb);
327 	memalloc_noreclaim_restore(noreclaim_flag);
328 
329 	return ret;
330 }
331 EXPORT_SYMBOL(__sk_backlog_rcv);
332 
333 static int sock_get_timeout(long timeo, void *optval, bool old_timeval)
334 {
335 	struct __kernel_sock_timeval tv;
336 
337 	if (timeo == MAX_SCHEDULE_TIMEOUT) {
338 		tv.tv_sec = 0;
339 		tv.tv_usec = 0;
340 	} else {
341 		tv.tv_sec = timeo / HZ;
342 		tv.tv_usec = ((timeo % HZ) * USEC_PER_SEC) / HZ;
343 	}
344 
345 	if (old_timeval && in_compat_syscall() && !COMPAT_USE_64BIT_TIME) {
346 		struct old_timeval32 tv32 = { tv.tv_sec, tv.tv_usec };
347 		*(struct old_timeval32 *)optval = tv32;
348 		return sizeof(tv32);
349 	}
350 
351 	if (old_timeval) {
352 		struct __kernel_old_timeval old_tv;
353 		old_tv.tv_sec = tv.tv_sec;
354 		old_tv.tv_usec = tv.tv_usec;
355 		*(struct __kernel_old_timeval *)optval = old_tv;
356 		return sizeof(old_tv);
357 	}
358 
359 	*(struct __kernel_sock_timeval *)optval = tv;
360 	return sizeof(tv);
361 }
362 
363 static int sock_set_timeout(long *timeo_p, char __user *optval, int optlen, bool old_timeval)
364 {
365 	struct __kernel_sock_timeval tv;
366 
367 	if (old_timeval && in_compat_syscall() && !COMPAT_USE_64BIT_TIME) {
368 		struct old_timeval32 tv32;
369 
370 		if (optlen < sizeof(tv32))
371 			return -EINVAL;
372 
373 		if (copy_from_user(&tv32, optval, sizeof(tv32)))
374 			return -EFAULT;
375 		tv.tv_sec = tv32.tv_sec;
376 		tv.tv_usec = tv32.tv_usec;
377 	} else if (old_timeval) {
378 		struct __kernel_old_timeval old_tv;
379 
380 		if (optlen < sizeof(old_tv))
381 			return -EINVAL;
382 		if (copy_from_user(&old_tv, optval, sizeof(old_tv)))
383 			return -EFAULT;
384 		tv.tv_sec = old_tv.tv_sec;
385 		tv.tv_usec = old_tv.tv_usec;
386 	} else {
387 		if (optlen < sizeof(tv))
388 			return -EINVAL;
389 		if (copy_from_user(&tv, optval, sizeof(tv)))
390 			return -EFAULT;
391 	}
392 	if (tv.tv_usec < 0 || tv.tv_usec >= USEC_PER_SEC)
393 		return -EDOM;
394 
395 	if (tv.tv_sec < 0) {
396 		static int warned __read_mostly;
397 
398 		*timeo_p = 0;
399 		if (warned < 10 && net_ratelimit()) {
400 			warned++;
401 			pr_info("%s: `%s' (pid %d) tries to set negative timeout\n",
402 				__func__, current->comm, task_pid_nr(current));
403 		}
404 		return 0;
405 	}
406 	*timeo_p = MAX_SCHEDULE_TIMEOUT;
407 	if (tv.tv_sec == 0 && tv.tv_usec == 0)
408 		return 0;
409 	if (tv.tv_sec < (MAX_SCHEDULE_TIMEOUT / HZ - 1))
410 		*timeo_p = tv.tv_sec * HZ + DIV_ROUND_UP((unsigned long)tv.tv_usec, USEC_PER_SEC / HZ);
411 	return 0;
412 }
413 
414 static void sock_warn_obsolete_bsdism(const char *name)
415 {
416 	static int warned;
417 	static char warncomm[TASK_COMM_LEN];
418 	if (strcmp(warncomm, current->comm) && warned < 5) {
419 		strcpy(warncomm,  current->comm);
420 		pr_warn("process `%s' is using obsolete %s SO_BSDCOMPAT\n",
421 			warncomm, name);
422 		warned++;
423 	}
424 }
425 
426 static bool sock_needs_netstamp(const struct sock *sk)
427 {
428 	switch (sk->sk_family) {
429 	case AF_UNSPEC:
430 	case AF_UNIX:
431 		return false;
432 	default:
433 		return true;
434 	}
435 }
436 
437 static void sock_disable_timestamp(struct sock *sk, unsigned long flags)
438 {
439 	if (sk->sk_flags & flags) {
440 		sk->sk_flags &= ~flags;
441 		if (sock_needs_netstamp(sk) &&
442 		    !(sk->sk_flags & SK_FLAGS_TIMESTAMP))
443 			net_disable_timestamp();
444 	}
445 }
446 
447 
448 int __sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
449 {
450 	unsigned long flags;
451 	struct sk_buff_head *list = &sk->sk_receive_queue;
452 
453 	if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf) {
454 		atomic_inc(&sk->sk_drops);
455 		trace_sock_rcvqueue_full(sk, skb);
456 		return -ENOMEM;
457 	}
458 
459 	if (!sk_rmem_schedule(sk, skb, skb->truesize)) {
460 		atomic_inc(&sk->sk_drops);
461 		return -ENOBUFS;
462 	}
463 
464 	skb->dev = NULL;
465 	skb_set_owner_r(skb, sk);
466 
467 	/* we escape from rcu protected region, make sure we dont leak
468 	 * a norefcounted dst
469 	 */
470 	skb_dst_force(skb);
471 
472 	spin_lock_irqsave(&list->lock, flags);
473 	sock_skb_set_dropcount(sk, skb);
474 	__skb_queue_tail(list, skb);
475 	spin_unlock_irqrestore(&list->lock, flags);
476 
477 	if (!sock_flag(sk, SOCK_DEAD))
478 		sk->sk_data_ready(sk);
479 	return 0;
480 }
481 EXPORT_SYMBOL(__sock_queue_rcv_skb);
482 
483 int sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
484 {
485 	int err;
486 
487 	err = sk_filter(sk, skb);
488 	if (err)
489 		return err;
490 
491 	return __sock_queue_rcv_skb(sk, skb);
492 }
493 EXPORT_SYMBOL(sock_queue_rcv_skb);
494 
495 int __sk_receive_skb(struct sock *sk, struct sk_buff *skb,
496 		     const int nested, unsigned int trim_cap, bool refcounted)
497 {
498 	int rc = NET_RX_SUCCESS;
499 
500 	if (sk_filter_trim_cap(sk, skb, trim_cap))
501 		goto discard_and_relse;
502 
503 	skb->dev = NULL;
504 
505 	if (sk_rcvqueues_full(sk, sk->sk_rcvbuf)) {
506 		atomic_inc(&sk->sk_drops);
507 		goto discard_and_relse;
508 	}
509 	if (nested)
510 		bh_lock_sock_nested(sk);
511 	else
512 		bh_lock_sock(sk);
513 	if (!sock_owned_by_user(sk)) {
514 		/*
515 		 * trylock + unlock semantics:
516 		 */
517 		mutex_acquire(&sk->sk_lock.dep_map, 0, 1, _RET_IP_);
518 
519 		rc = sk_backlog_rcv(sk, skb);
520 
521 		mutex_release(&sk->sk_lock.dep_map, _RET_IP_);
522 	} else if (sk_add_backlog(sk, skb, READ_ONCE(sk->sk_rcvbuf))) {
523 		bh_unlock_sock(sk);
524 		atomic_inc(&sk->sk_drops);
525 		goto discard_and_relse;
526 	}
527 
528 	bh_unlock_sock(sk);
529 out:
530 	if (refcounted)
531 		sock_put(sk);
532 	return rc;
533 discard_and_relse:
534 	kfree_skb(skb);
535 	goto out;
536 }
537 EXPORT_SYMBOL(__sk_receive_skb);
538 
539 struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie)
540 {
541 	struct dst_entry *dst = __sk_dst_get(sk);
542 
543 	if (dst && dst->obsolete && dst->ops->check(dst, cookie) == NULL) {
544 		sk_tx_queue_clear(sk);
545 		sk->sk_dst_pending_confirm = 0;
546 		RCU_INIT_POINTER(sk->sk_dst_cache, NULL);
547 		dst_release(dst);
548 		return NULL;
549 	}
550 
551 	return dst;
552 }
553 EXPORT_SYMBOL(__sk_dst_check);
554 
555 struct dst_entry *sk_dst_check(struct sock *sk, u32 cookie)
556 {
557 	struct dst_entry *dst = sk_dst_get(sk);
558 
559 	if (dst && dst->obsolete && dst->ops->check(dst, cookie) == NULL) {
560 		sk_dst_reset(sk);
561 		dst_release(dst);
562 		return NULL;
563 	}
564 
565 	return dst;
566 }
567 EXPORT_SYMBOL(sk_dst_check);
568 
569 static int sock_setbindtodevice_locked(struct sock *sk, int ifindex)
570 {
571 	int ret = -ENOPROTOOPT;
572 #ifdef CONFIG_NETDEVICES
573 	struct net *net = sock_net(sk);
574 
575 	/* Sorry... */
576 	ret = -EPERM;
577 	if (!ns_capable(net->user_ns, CAP_NET_RAW))
578 		goto out;
579 
580 	ret = -EINVAL;
581 	if (ifindex < 0)
582 		goto out;
583 
584 	sk->sk_bound_dev_if = ifindex;
585 	if (sk->sk_prot->rehash)
586 		sk->sk_prot->rehash(sk);
587 	sk_dst_reset(sk);
588 
589 	ret = 0;
590 
591 out:
592 #endif
593 
594 	return ret;
595 }
596 
597 static int sock_setbindtodevice(struct sock *sk, char __user *optval,
598 				int optlen)
599 {
600 	int ret = -ENOPROTOOPT;
601 #ifdef CONFIG_NETDEVICES
602 	struct net *net = sock_net(sk);
603 	char devname[IFNAMSIZ];
604 	int index;
605 
606 	ret = -EINVAL;
607 	if (optlen < 0)
608 		goto out;
609 
610 	/* Bind this socket to a particular device like "eth0",
611 	 * as specified in the passed interface name. If the
612 	 * name is "" or the option length is zero the socket
613 	 * is not bound.
614 	 */
615 	if (optlen > IFNAMSIZ - 1)
616 		optlen = IFNAMSIZ - 1;
617 	memset(devname, 0, sizeof(devname));
618 
619 	ret = -EFAULT;
620 	if (copy_from_user(devname, optval, optlen))
621 		goto out;
622 
623 	index = 0;
624 	if (devname[0] != '\0') {
625 		struct net_device *dev;
626 
627 		rcu_read_lock();
628 		dev = dev_get_by_name_rcu(net, devname);
629 		if (dev)
630 			index = dev->ifindex;
631 		rcu_read_unlock();
632 		ret = -ENODEV;
633 		if (!dev)
634 			goto out;
635 	}
636 
637 	lock_sock(sk);
638 	ret = sock_setbindtodevice_locked(sk, index);
639 	release_sock(sk);
640 
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 static inline void sock_valbool_flag(struct sock *sk, enum sock_flags bit,
688 				     int valbool)
689 {
690 	if (valbool)
691 		sock_set_flag(sk, bit);
692 	else
693 		sock_reset_flag(sk, bit);
694 }
695 
696 bool sk_mc_loop(struct sock *sk)
697 {
698 	if (dev_recursion_level())
699 		return false;
700 	if (!sk)
701 		return true;
702 	switch (sk->sk_family) {
703 	case AF_INET:
704 		return inet_sk(sk)->mc_loop;
705 #if IS_ENABLED(CONFIG_IPV6)
706 	case AF_INET6:
707 		return inet6_sk(sk)->mc_loop;
708 #endif
709 	}
710 	WARN_ON(1);
711 	return true;
712 }
713 EXPORT_SYMBOL(sk_mc_loop);
714 
715 /*
716  *	This is meant for all protocols to use and covers goings on
717  *	at the socket level. Everything here is generic.
718  */
719 
720 int sock_setsockopt(struct socket *sock, int level, int optname,
721 		    char __user *optval, unsigned int optlen)
722 {
723 	struct sock_txtime sk_txtime;
724 	struct sock *sk = sock->sk;
725 	int val;
726 	int valbool;
727 	struct linger ling;
728 	int ret = 0;
729 
730 	/*
731 	 *	Options without arguments
732 	 */
733 
734 	if (optname == SO_BINDTODEVICE)
735 		return sock_setbindtodevice(sk, optval, optlen);
736 
737 	if (optlen < sizeof(int))
738 		return -EINVAL;
739 
740 	if (get_user(val, (int __user *)optval))
741 		return -EFAULT;
742 
743 	valbool = val ? 1 : 0;
744 
745 	lock_sock(sk);
746 
747 	switch (optname) {
748 	case SO_DEBUG:
749 		if (val && !capable(CAP_NET_ADMIN))
750 			ret = -EACCES;
751 		else
752 			sock_valbool_flag(sk, SOCK_DBG, valbool);
753 		break;
754 	case SO_REUSEADDR:
755 		sk->sk_reuse = (valbool ? SK_CAN_REUSE : SK_NO_REUSE);
756 		break;
757 	case SO_REUSEPORT:
758 		sk->sk_reuseport = valbool;
759 		break;
760 	case SO_TYPE:
761 	case SO_PROTOCOL:
762 	case SO_DOMAIN:
763 	case SO_ERROR:
764 		ret = -ENOPROTOOPT;
765 		break;
766 	case SO_DONTROUTE:
767 		sock_valbool_flag(sk, SOCK_LOCALROUTE, valbool);
768 		sk_dst_reset(sk);
769 		break;
770 	case SO_BROADCAST:
771 		sock_valbool_flag(sk, SOCK_BROADCAST, valbool);
772 		break;
773 	case SO_SNDBUF:
774 		/* Don't error on this BSD doesn't and if you think
775 		 * about it this is right. Otherwise apps have to
776 		 * play 'guess the biggest size' games. RCVBUF/SNDBUF
777 		 * are treated in BSD as hints
778 		 */
779 		val = min_t(u32, val, sysctl_wmem_max);
780 set_sndbuf:
781 		/* Ensure val * 2 fits into an int, to prevent max_t()
782 		 * from treating it as a negative value.
783 		 */
784 		val = min_t(int, val, INT_MAX / 2);
785 		sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
786 		WRITE_ONCE(sk->sk_sndbuf,
787 			   max_t(int, val * 2, SOCK_MIN_SNDBUF));
788 		/* Wake up sending tasks if we upped the value. */
789 		sk->sk_write_space(sk);
790 		break;
791 
792 	case SO_SNDBUFFORCE:
793 		if (!capable(CAP_NET_ADMIN)) {
794 			ret = -EPERM;
795 			break;
796 		}
797 
798 		/* No negative values (to prevent underflow, as val will be
799 		 * multiplied by 2).
800 		 */
801 		if (val < 0)
802 			val = 0;
803 		goto set_sndbuf;
804 
805 	case SO_RCVBUF:
806 		/* Don't error on this BSD doesn't and if you think
807 		 * about it this is right. Otherwise apps have to
808 		 * play 'guess the biggest size' games. RCVBUF/SNDBUF
809 		 * are treated in BSD as hints
810 		 */
811 		val = min_t(u32, val, sysctl_rmem_max);
812 set_rcvbuf:
813 		/* Ensure val * 2 fits into an int, to prevent max_t()
814 		 * from treating it as a negative value.
815 		 */
816 		val = min_t(int, val, INT_MAX / 2);
817 		sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
818 		/*
819 		 * We double it on the way in to account for
820 		 * "struct sk_buff" etc. overhead.   Applications
821 		 * assume that the SO_RCVBUF setting they make will
822 		 * allow that much actual data to be received on that
823 		 * socket.
824 		 *
825 		 * Applications are unaware that "struct sk_buff" and
826 		 * other overheads allocate from the receive buffer
827 		 * during socket buffer allocation.
828 		 *
829 		 * And after considering the possible alternatives,
830 		 * returning the value we actually used in getsockopt
831 		 * is the most desirable behavior.
832 		 */
833 		WRITE_ONCE(sk->sk_rcvbuf,
834 			   max_t(int, val * 2, SOCK_MIN_RCVBUF));
835 		break;
836 
837 	case SO_RCVBUFFORCE:
838 		if (!capable(CAP_NET_ADMIN)) {
839 			ret = -EPERM;
840 			break;
841 		}
842 
843 		/* No negative values (to prevent underflow, as val will be
844 		 * multiplied by 2).
845 		 */
846 		if (val < 0)
847 			val = 0;
848 		goto set_rcvbuf;
849 
850 	case SO_KEEPALIVE:
851 		if (sk->sk_prot->keepalive)
852 			sk->sk_prot->keepalive(sk, valbool);
853 		sock_valbool_flag(sk, SOCK_KEEPOPEN, valbool);
854 		break;
855 
856 	case SO_OOBINLINE:
857 		sock_valbool_flag(sk, SOCK_URGINLINE, valbool);
858 		break;
859 
860 	case SO_NO_CHECK:
861 		sk->sk_no_check_tx = valbool;
862 		break;
863 
864 	case SO_PRIORITY:
865 		if ((val >= 0 && val <= 6) ||
866 		    ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
867 			sk->sk_priority = val;
868 		else
869 			ret = -EPERM;
870 		break;
871 
872 	case SO_LINGER:
873 		if (optlen < sizeof(ling)) {
874 			ret = -EINVAL;	/* 1003.1g */
875 			break;
876 		}
877 		if (copy_from_user(&ling, optval, sizeof(ling))) {
878 			ret = -EFAULT;
879 			break;
880 		}
881 		if (!ling.l_onoff)
882 			sock_reset_flag(sk, SOCK_LINGER);
883 		else {
884 #if (BITS_PER_LONG == 32)
885 			if ((unsigned int)ling.l_linger >= MAX_SCHEDULE_TIMEOUT/HZ)
886 				sk->sk_lingertime = MAX_SCHEDULE_TIMEOUT;
887 			else
888 #endif
889 				sk->sk_lingertime = (unsigned int)ling.l_linger * HZ;
890 			sock_set_flag(sk, SOCK_LINGER);
891 		}
892 		break;
893 
894 	case SO_BSDCOMPAT:
895 		sock_warn_obsolete_bsdism("setsockopt");
896 		break;
897 
898 	case SO_PASSCRED:
899 		if (valbool)
900 			set_bit(SOCK_PASSCRED, &sock->flags);
901 		else
902 			clear_bit(SOCK_PASSCRED, &sock->flags);
903 		break;
904 
905 	case SO_TIMESTAMP_OLD:
906 	case SO_TIMESTAMP_NEW:
907 	case SO_TIMESTAMPNS_OLD:
908 	case SO_TIMESTAMPNS_NEW:
909 		if (valbool)  {
910 			if (optname == SO_TIMESTAMP_NEW || optname == SO_TIMESTAMPNS_NEW)
911 				sock_set_flag(sk, SOCK_TSTAMP_NEW);
912 			else
913 				sock_reset_flag(sk, SOCK_TSTAMP_NEW);
914 
915 			if (optname == SO_TIMESTAMP_OLD || optname == SO_TIMESTAMP_NEW)
916 				sock_reset_flag(sk, SOCK_RCVTSTAMPNS);
917 			else
918 				sock_set_flag(sk, SOCK_RCVTSTAMPNS);
919 			sock_set_flag(sk, SOCK_RCVTSTAMP);
920 			sock_enable_timestamp(sk, SOCK_TIMESTAMP);
921 		} else {
922 			sock_reset_flag(sk, SOCK_RCVTSTAMP);
923 			sock_reset_flag(sk, SOCK_RCVTSTAMPNS);
924 			sock_reset_flag(sk, SOCK_TSTAMP_NEW);
925 		}
926 		break;
927 
928 	case SO_TIMESTAMPING_NEW:
929 		sock_set_flag(sk, SOCK_TSTAMP_NEW);
930 		/* fall through */
931 	case SO_TIMESTAMPING_OLD:
932 		if (val & ~SOF_TIMESTAMPING_MASK) {
933 			ret = -EINVAL;
934 			break;
935 		}
936 
937 		if (val & SOF_TIMESTAMPING_OPT_ID &&
938 		    !(sk->sk_tsflags & SOF_TIMESTAMPING_OPT_ID)) {
939 			if (sk->sk_protocol == IPPROTO_TCP &&
940 			    sk->sk_type == SOCK_STREAM) {
941 				if ((1 << sk->sk_state) &
942 				    (TCPF_CLOSE | TCPF_LISTEN)) {
943 					ret = -EINVAL;
944 					break;
945 				}
946 				sk->sk_tskey = tcp_sk(sk)->snd_una;
947 			} else {
948 				sk->sk_tskey = 0;
949 			}
950 		}
951 
952 		if (val & SOF_TIMESTAMPING_OPT_STATS &&
953 		    !(val & SOF_TIMESTAMPING_OPT_TSONLY)) {
954 			ret = -EINVAL;
955 			break;
956 		}
957 
958 		sk->sk_tsflags = val;
959 		if (val & SOF_TIMESTAMPING_RX_SOFTWARE)
960 			sock_enable_timestamp(sk,
961 					      SOCK_TIMESTAMPING_RX_SOFTWARE);
962 		else {
963 			if (optname == SO_TIMESTAMPING_NEW)
964 				sock_reset_flag(sk, SOCK_TSTAMP_NEW);
965 
966 			sock_disable_timestamp(sk,
967 					       (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE));
968 		}
969 		break;
970 
971 	case SO_RCVLOWAT:
972 		if (val < 0)
973 			val = INT_MAX;
974 		if (sock->ops->set_rcvlowat)
975 			ret = sock->ops->set_rcvlowat(sk, val);
976 		else
977 			WRITE_ONCE(sk->sk_rcvlowat, val ? : 1);
978 		break;
979 
980 	case SO_RCVTIMEO_OLD:
981 	case SO_RCVTIMEO_NEW:
982 		ret = sock_set_timeout(&sk->sk_rcvtimeo, optval, optlen, optname == SO_RCVTIMEO_OLD);
983 		break;
984 
985 	case SO_SNDTIMEO_OLD:
986 	case SO_SNDTIMEO_NEW:
987 		ret = sock_set_timeout(&sk->sk_sndtimeo, optval, optlen, optname == SO_SNDTIMEO_OLD);
988 		break;
989 
990 	case SO_ATTACH_FILTER:
991 		ret = -EINVAL;
992 		if (optlen == sizeof(struct sock_fprog)) {
993 			struct sock_fprog fprog;
994 
995 			ret = -EFAULT;
996 			if (copy_from_user(&fprog, optval, sizeof(fprog)))
997 				break;
998 
999 			ret = sk_attach_filter(&fprog, sk);
1000 		}
1001 		break;
1002 
1003 	case SO_ATTACH_BPF:
1004 		ret = -EINVAL;
1005 		if (optlen == sizeof(u32)) {
1006 			u32 ufd;
1007 
1008 			ret = -EFAULT;
1009 			if (copy_from_user(&ufd, optval, sizeof(ufd)))
1010 				break;
1011 
1012 			ret = sk_attach_bpf(ufd, sk);
1013 		}
1014 		break;
1015 
1016 	case SO_ATTACH_REUSEPORT_CBPF:
1017 		ret = -EINVAL;
1018 		if (optlen == sizeof(struct sock_fprog)) {
1019 			struct sock_fprog fprog;
1020 
1021 			ret = -EFAULT;
1022 			if (copy_from_user(&fprog, optval, sizeof(fprog)))
1023 				break;
1024 
1025 			ret = sk_reuseport_attach_filter(&fprog, sk);
1026 		}
1027 		break;
1028 
1029 	case SO_ATTACH_REUSEPORT_EBPF:
1030 		ret = -EINVAL;
1031 		if (optlen == sizeof(u32)) {
1032 			u32 ufd;
1033 
1034 			ret = -EFAULT;
1035 			if (copy_from_user(&ufd, optval, sizeof(ufd)))
1036 				break;
1037 
1038 			ret = sk_reuseport_attach_bpf(ufd, sk);
1039 		}
1040 		break;
1041 
1042 	case SO_DETACH_REUSEPORT_BPF:
1043 		ret = reuseport_detach_prog(sk);
1044 		break;
1045 
1046 	case SO_DETACH_FILTER:
1047 		ret = sk_detach_filter(sk);
1048 		break;
1049 
1050 	case SO_LOCK_FILTER:
1051 		if (sock_flag(sk, SOCK_FILTER_LOCKED) && !valbool)
1052 			ret = -EPERM;
1053 		else
1054 			sock_valbool_flag(sk, SOCK_FILTER_LOCKED, valbool);
1055 		break;
1056 
1057 	case SO_PASSSEC:
1058 		if (valbool)
1059 			set_bit(SOCK_PASSSEC, &sock->flags);
1060 		else
1061 			clear_bit(SOCK_PASSSEC, &sock->flags);
1062 		break;
1063 	case SO_MARK:
1064 		if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) {
1065 			ret = -EPERM;
1066 		} else if (val != sk->sk_mark) {
1067 			sk->sk_mark = val;
1068 			sk_dst_reset(sk);
1069 		}
1070 		break;
1071 
1072 	case SO_RXQ_OVFL:
1073 		sock_valbool_flag(sk, SOCK_RXQ_OVFL, valbool);
1074 		break;
1075 
1076 	case SO_WIFI_STATUS:
1077 		sock_valbool_flag(sk, SOCK_WIFI_STATUS, valbool);
1078 		break;
1079 
1080 	case SO_PEEK_OFF:
1081 		if (sock->ops->set_peek_off)
1082 			ret = sock->ops->set_peek_off(sk, val);
1083 		else
1084 			ret = -EOPNOTSUPP;
1085 		break;
1086 
1087 	case SO_NOFCS:
1088 		sock_valbool_flag(sk, SOCK_NOFCS, valbool);
1089 		break;
1090 
1091 	case SO_SELECT_ERR_QUEUE:
1092 		sock_valbool_flag(sk, SOCK_SELECT_ERR_QUEUE, valbool);
1093 		break;
1094 
1095 #ifdef CONFIG_NET_RX_BUSY_POLL
1096 	case SO_BUSY_POLL:
1097 		/* allow unprivileged users to decrease the value */
1098 		if ((val > sk->sk_ll_usec) && !capable(CAP_NET_ADMIN))
1099 			ret = -EPERM;
1100 		else {
1101 			if (val < 0)
1102 				ret = -EINVAL;
1103 			else
1104 				sk->sk_ll_usec = val;
1105 		}
1106 		break;
1107 #endif
1108 
1109 	case SO_MAX_PACING_RATE:
1110 		{
1111 		unsigned long ulval = (val == ~0U) ? ~0UL : val;
1112 
1113 		if (sizeof(ulval) != sizeof(val) &&
1114 		    optlen >= sizeof(ulval) &&
1115 		    get_user(ulval, (unsigned long __user *)optval)) {
1116 			ret = -EFAULT;
1117 			break;
1118 		}
1119 		if (ulval != ~0UL)
1120 			cmpxchg(&sk->sk_pacing_status,
1121 				SK_PACING_NONE,
1122 				SK_PACING_NEEDED);
1123 		sk->sk_max_pacing_rate = ulval;
1124 		sk->sk_pacing_rate = min(sk->sk_pacing_rate, ulval);
1125 		break;
1126 		}
1127 	case SO_INCOMING_CPU:
1128 		WRITE_ONCE(sk->sk_incoming_cpu, val);
1129 		break;
1130 
1131 	case SO_CNX_ADVICE:
1132 		if (val == 1)
1133 			dst_negative_advice(sk);
1134 		break;
1135 
1136 	case SO_ZEROCOPY:
1137 		if (sk->sk_family == PF_INET || sk->sk_family == PF_INET6) {
1138 			if (!((sk->sk_type == SOCK_STREAM &&
1139 			       sk->sk_protocol == IPPROTO_TCP) ||
1140 			      (sk->sk_type == SOCK_DGRAM &&
1141 			       sk->sk_protocol == IPPROTO_UDP)))
1142 				ret = -ENOTSUPP;
1143 		} else if (sk->sk_family != PF_RDS) {
1144 			ret = -ENOTSUPP;
1145 		}
1146 		if (!ret) {
1147 			if (val < 0 || val > 1)
1148 				ret = -EINVAL;
1149 			else
1150 				sock_valbool_flag(sk, SOCK_ZEROCOPY, valbool);
1151 		}
1152 		break;
1153 
1154 	case SO_TXTIME:
1155 		if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) {
1156 			ret = -EPERM;
1157 		} else if (optlen != sizeof(struct sock_txtime)) {
1158 			ret = -EINVAL;
1159 		} else if (copy_from_user(&sk_txtime, optval,
1160 			   sizeof(struct sock_txtime))) {
1161 			ret = -EFAULT;
1162 		} else if (sk_txtime.flags & ~SOF_TXTIME_FLAGS_MASK) {
1163 			ret = -EINVAL;
1164 		} else {
1165 			sock_valbool_flag(sk, SOCK_TXTIME, true);
1166 			sk->sk_clockid = sk_txtime.clockid;
1167 			sk->sk_txtime_deadline_mode =
1168 				!!(sk_txtime.flags & SOF_TXTIME_DEADLINE_MODE);
1169 			sk->sk_txtime_report_errors =
1170 				!!(sk_txtime.flags & SOF_TXTIME_REPORT_ERRORS);
1171 		}
1172 		break;
1173 
1174 	case SO_BINDTOIFINDEX:
1175 		ret = sock_setbindtodevice_locked(sk, val);
1176 		break;
1177 
1178 	default:
1179 		ret = -ENOPROTOOPT;
1180 		break;
1181 	}
1182 	release_sock(sk);
1183 	return ret;
1184 }
1185 EXPORT_SYMBOL(sock_setsockopt);
1186 
1187 
1188 static void cred_to_ucred(struct pid *pid, const struct cred *cred,
1189 			  struct ucred *ucred)
1190 {
1191 	ucred->pid = pid_vnr(pid);
1192 	ucred->uid = ucred->gid = -1;
1193 	if (cred) {
1194 		struct user_namespace *current_ns = current_user_ns();
1195 
1196 		ucred->uid = from_kuid_munged(current_ns, cred->euid);
1197 		ucred->gid = from_kgid_munged(current_ns, cred->egid);
1198 	}
1199 }
1200 
1201 static int groups_to_user(gid_t __user *dst, const struct group_info *src)
1202 {
1203 	struct user_namespace *user_ns = current_user_ns();
1204 	int i;
1205 
1206 	for (i = 0; i < src->ngroups; i++)
1207 		if (put_user(from_kgid_munged(user_ns, src->gid[i]), dst + i))
1208 			return -EFAULT;
1209 
1210 	return 0;
1211 }
1212 
1213 int sock_getsockopt(struct socket *sock, int level, int optname,
1214 		    char __user *optval, int __user *optlen)
1215 {
1216 	struct sock *sk = sock->sk;
1217 
1218 	union {
1219 		int val;
1220 		u64 val64;
1221 		unsigned long ulval;
1222 		struct linger ling;
1223 		struct old_timeval32 tm32;
1224 		struct __kernel_old_timeval tm;
1225 		struct  __kernel_sock_timeval stm;
1226 		struct sock_txtime txtime;
1227 	} v;
1228 
1229 	int lv = sizeof(int);
1230 	int len;
1231 
1232 	if (get_user(len, optlen))
1233 		return -EFAULT;
1234 	if (len < 0)
1235 		return -EINVAL;
1236 
1237 	memset(&v, 0, sizeof(v));
1238 
1239 	switch (optname) {
1240 	case SO_DEBUG:
1241 		v.val = sock_flag(sk, SOCK_DBG);
1242 		break;
1243 
1244 	case SO_DONTROUTE:
1245 		v.val = sock_flag(sk, SOCK_LOCALROUTE);
1246 		break;
1247 
1248 	case SO_BROADCAST:
1249 		v.val = sock_flag(sk, SOCK_BROADCAST);
1250 		break;
1251 
1252 	case SO_SNDBUF:
1253 		v.val = sk->sk_sndbuf;
1254 		break;
1255 
1256 	case SO_RCVBUF:
1257 		v.val = sk->sk_rcvbuf;
1258 		break;
1259 
1260 	case SO_REUSEADDR:
1261 		v.val = sk->sk_reuse;
1262 		break;
1263 
1264 	case SO_REUSEPORT:
1265 		v.val = sk->sk_reuseport;
1266 		break;
1267 
1268 	case SO_KEEPALIVE:
1269 		v.val = sock_flag(sk, SOCK_KEEPOPEN);
1270 		break;
1271 
1272 	case SO_TYPE:
1273 		v.val = sk->sk_type;
1274 		break;
1275 
1276 	case SO_PROTOCOL:
1277 		v.val = sk->sk_protocol;
1278 		break;
1279 
1280 	case SO_DOMAIN:
1281 		v.val = sk->sk_family;
1282 		break;
1283 
1284 	case SO_ERROR:
1285 		v.val = -sock_error(sk);
1286 		if (v.val == 0)
1287 			v.val = xchg(&sk->sk_err_soft, 0);
1288 		break;
1289 
1290 	case SO_OOBINLINE:
1291 		v.val = sock_flag(sk, SOCK_URGINLINE);
1292 		break;
1293 
1294 	case SO_NO_CHECK:
1295 		v.val = sk->sk_no_check_tx;
1296 		break;
1297 
1298 	case SO_PRIORITY:
1299 		v.val = sk->sk_priority;
1300 		break;
1301 
1302 	case SO_LINGER:
1303 		lv		= sizeof(v.ling);
1304 		v.ling.l_onoff	= sock_flag(sk, SOCK_LINGER);
1305 		v.ling.l_linger	= sk->sk_lingertime / HZ;
1306 		break;
1307 
1308 	case SO_BSDCOMPAT:
1309 		sock_warn_obsolete_bsdism("getsockopt");
1310 		break;
1311 
1312 	case SO_TIMESTAMP_OLD:
1313 		v.val = sock_flag(sk, SOCK_RCVTSTAMP) &&
1314 				!sock_flag(sk, SOCK_TSTAMP_NEW) &&
1315 				!sock_flag(sk, SOCK_RCVTSTAMPNS);
1316 		break;
1317 
1318 	case SO_TIMESTAMPNS_OLD:
1319 		v.val = sock_flag(sk, SOCK_RCVTSTAMPNS) && !sock_flag(sk, SOCK_TSTAMP_NEW);
1320 		break;
1321 
1322 	case SO_TIMESTAMP_NEW:
1323 		v.val = sock_flag(sk, SOCK_RCVTSTAMP) && sock_flag(sk, SOCK_TSTAMP_NEW);
1324 		break;
1325 
1326 	case SO_TIMESTAMPNS_NEW:
1327 		v.val = sock_flag(sk, SOCK_RCVTSTAMPNS) && sock_flag(sk, SOCK_TSTAMP_NEW);
1328 		break;
1329 
1330 	case SO_TIMESTAMPING_OLD:
1331 		v.val = sk->sk_tsflags;
1332 		break;
1333 
1334 	case SO_RCVTIMEO_OLD:
1335 	case SO_RCVTIMEO_NEW:
1336 		lv = sock_get_timeout(sk->sk_rcvtimeo, &v, SO_RCVTIMEO_OLD == optname);
1337 		break;
1338 
1339 	case SO_SNDTIMEO_OLD:
1340 	case SO_SNDTIMEO_NEW:
1341 		lv = sock_get_timeout(sk->sk_sndtimeo, &v, SO_SNDTIMEO_OLD == optname);
1342 		break;
1343 
1344 	case SO_RCVLOWAT:
1345 		v.val = sk->sk_rcvlowat;
1346 		break;
1347 
1348 	case SO_SNDLOWAT:
1349 		v.val = 1;
1350 		break;
1351 
1352 	case SO_PASSCRED:
1353 		v.val = !!test_bit(SOCK_PASSCRED, &sock->flags);
1354 		break;
1355 
1356 	case SO_PEERCRED:
1357 	{
1358 		struct ucred peercred;
1359 		if (len > sizeof(peercred))
1360 			len = sizeof(peercred);
1361 		cred_to_ucred(sk->sk_peer_pid, sk->sk_peer_cred, &peercred);
1362 		if (copy_to_user(optval, &peercred, len))
1363 			return -EFAULT;
1364 		goto lenout;
1365 	}
1366 
1367 	case SO_PEERGROUPS:
1368 	{
1369 		int ret, n;
1370 
1371 		if (!sk->sk_peer_cred)
1372 			return -ENODATA;
1373 
1374 		n = sk->sk_peer_cred->group_info->ngroups;
1375 		if (len < n * sizeof(gid_t)) {
1376 			len = n * sizeof(gid_t);
1377 			return put_user(len, optlen) ? -EFAULT : -ERANGE;
1378 		}
1379 		len = n * sizeof(gid_t);
1380 
1381 		ret = groups_to_user((gid_t __user *)optval,
1382 				     sk->sk_peer_cred->group_info);
1383 		if (ret)
1384 			return ret;
1385 		goto lenout;
1386 	}
1387 
1388 	case SO_PEERNAME:
1389 	{
1390 		char address[128];
1391 
1392 		lv = sock->ops->getname(sock, (struct sockaddr *)address, 2);
1393 		if (lv < 0)
1394 			return -ENOTCONN;
1395 		if (lv < len)
1396 			return -EINVAL;
1397 		if (copy_to_user(optval, address, len))
1398 			return -EFAULT;
1399 		goto lenout;
1400 	}
1401 
1402 	/* Dubious BSD thing... Probably nobody even uses it, but
1403 	 * the UNIX standard wants it for whatever reason... -DaveM
1404 	 */
1405 	case SO_ACCEPTCONN:
1406 		v.val = sk->sk_state == TCP_LISTEN;
1407 		break;
1408 
1409 	case SO_PASSSEC:
1410 		v.val = !!test_bit(SOCK_PASSSEC, &sock->flags);
1411 		break;
1412 
1413 	case SO_PEERSEC:
1414 		return security_socket_getpeersec_stream(sock, optval, optlen, len);
1415 
1416 	case SO_MARK:
1417 		v.val = sk->sk_mark;
1418 		break;
1419 
1420 	case SO_RXQ_OVFL:
1421 		v.val = sock_flag(sk, SOCK_RXQ_OVFL);
1422 		break;
1423 
1424 	case SO_WIFI_STATUS:
1425 		v.val = sock_flag(sk, SOCK_WIFI_STATUS);
1426 		break;
1427 
1428 	case SO_PEEK_OFF:
1429 		if (!sock->ops->set_peek_off)
1430 			return -EOPNOTSUPP;
1431 
1432 		v.val = sk->sk_peek_off;
1433 		break;
1434 	case SO_NOFCS:
1435 		v.val = sock_flag(sk, SOCK_NOFCS);
1436 		break;
1437 
1438 	case SO_BINDTODEVICE:
1439 		return sock_getbindtodevice(sk, optval, optlen, len);
1440 
1441 	case SO_GET_FILTER:
1442 		len = sk_get_filter(sk, (struct sock_filter __user *)optval, len);
1443 		if (len < 0)
1444 			return len;
1445 
1446 		goto lenout;
1447 
1448 	case SO_LOCK_FILTER:
1449 		v.val = sock_flag(sk, SOCK_FILTER_LOCKED);
1450 		break;
1451 
1452 	case SO_BPF_EXTENSIONS:
1453 		v.val = bpf_tell_extensions();
1454 		break;
1455 
1456 	case SO_SELECT_ERR_QUEUE:
1457 		v.val = sock_flag(sk, SOCK_SELECT_ERR_QUEUE);
1458 		break;
1459 
1460 #ifdef CONFIG_NET_RX_BUSY_POLL
1461 	case SO_BUSY_POLL:
1462 		v.val = sk->sk_ll_usec;
1463 		break;
1464 #endif
1465 
1466 	case SO_MAX_PACING_RATE:
1467 		if (sizeof(v.ulval) != sizeof(v.val) && len >= sizeof(v.ulval)) {
1468 			lv = sizeof(v.ulval);
1469 			v.ulval = sk->sk_max_pacing_rate;
1470 		} else {
1471 			/* 32bit version */
1472 			v.val = min_t(unsigned long, sk->sk_max_pacing_rate, ~0U);
1473 		}
1474 		break;
1475 
1476 	case SO_INCOMING_CPU:
1477 		v.val = READ_ONCE(sk->sk_incoming_cpu);
1478 		break;
1479 
1480 	case SO_MEMINFO:
1481 	{
1482 		u32 meminfo[SK_MEMINFO_VARS];
1483 
1484 		sk_get_meminfo(sk, meminfo);
1485 
1486 		len = min_t(unsigned int, len, sizeof(meminfo));
1487 		if (copy_to_user(optval, &meminfo, len))
1488 			return -EFAULT;
1489 
1490 		goto lenout;
1491 	}
1492 
1493 #ifdef CONFIG_NET_RX_BUSY_POLL
1494 	case SO_INCOMING_NAPI_ID:
1495 		v.val = READ_ONCE(sk->sk_napi_id);
1496 
1497 		/* aggregate non-NAPI IDs down to 0 */
1498 		if (v.val < MIN_NAPI_ID)
1499 			v.val = 0;
1500 
1501 		break;
1502 #endif
1503 
1504 	case SO_COOKIE:
1505 		lv = sizeof(u64);
1506 		if (len < lv)
1507 			return -EINVAL;
1508 		v.val64 = sock_gen_cookie(sk);
1509 		break;
1510 
1511 	case SO_ZEROCOPY:
1512 		v.val = sock_flag(sk, SOCK_ZEROCOPY);
1513 		break;
1514 
1515 	case SO_TXTIME:
1516 		lv = sizeof(v.txtime);
1517 		v.txtime.clockid = sk->sk_clockid;
1518 		v.txtime.flags |= sk->sk_txtime_deadline_mode ?
1519 				  SOF_TXTIME_DEADLINE_MODE : 0;
1520 		v.txtime.flags |= sk->sk_txtime_report_errors ?
1521 				  SOF_TXTIME_REPORT_ERRORS : 0;
1522 		break;
1523 
1524 	case SO_BINDTOIFINDEX:
1525 		v.val = sk->sk_bound_dev_if;
1526 		break;
1527 
1528 	default:
1529 		/* We implement the SO_SNDLOWAT etc to not be settable
1530 		 * (1003.1g 7).
1531 		 */
1532 		return -ENOPROTOOPT;
1533 	}
1534 
1535 	if (len > lv)
1536 		len = lv;
1537 	if (copy_to_user(optval, &v, len))
1538 		return -EFAULT;
1539 lenout:
1540 	if (put_user(len, optlen))
1541 		return -EFAULT;
1542 	return 0;
1543 }
1544 
1545 /*
1546  * Initialize an sk_lock.
1547  *
1548  * (We also register the sk_lock with the lock validator.)
1549  */
1550 static inline void sock_lock_init(struct sock *sk)
1551 {
1552 	if (sk->sk_kern_sock)
1553 		sock_lock_init_class_and_name(
1554 			sk,
1555 			af_family_kern_slock_key_strings[sk->sk_family],
1556 			af_family_kern_slock_keys + sk->sk_family,
1557 			af_family_kern_key_strings[sk->sk_family],
1558 			af_family_kern_keys + sk->sk_family);
1559 	else
1560 		sock_lock_init_class_and_name(
1561 			sk,
1562 			af_family_slock_key_strings[sk->sk_family],
1563 			af_family_slock_keys + sk->sk_family,
1564 			af_family_key_strings[sk->sk_family],
1565 			af_family_keys + sk->sk_family);
1566 }
1567 
1568 /*
1569  * Copy all fields from osk to nsk but nsk->sk_refcnt must not change yet,
1570  * even temporarly, because of RCU lookups. sk_node should also be left as is.
1571  * We must not copy fields between sk_dontcopy_begin and sk_dontcopy_end
1572  */
1573 static void sock_copy(struct sock *nsk, const struct sock *osk)
1574 {
1575 #ifdef CONFIG_SECURITY_NETWORK
1576 	void *sptr = nsk->sk_security;
1577 #endif
1578 	memcpy(nsk, osk, offsetof(struct sock, sk_dontcopy_begin));
1579 
1580 	memcpy(&nsk->sk_dontcopy_end, &osk->sk_dontcopy_end,
1581 	       osk->sk_prot->obj_size - offsetof(struct sock, sk_dontcopy_end));
1582 
1583 #ifdef CONFIG_SECURITY_NETWORK
1584 	nsk->sk_security = sptr;
1585 	security_sk_clone(osk, nsk);
1586 #endif
1587 }
1588 
1589 static struct sock *sk_prot_alloc(struct proto *prot, gfp_t priority,
1590 		int family)
1591 {
1592 	struct sock *sk;
1593 	struct kmem_cache *slab;
1594 
1595 	slab = prot->slab;
1596 	if (slab != NULL) {
1597 		sk = kmem_cache_alloc(slab, priority & ~__GFP_ZERO);
1598 		if (!sk)
1599 			return sk;
1600 		if (want_init_on_alloc(priority))
1601 			sk_prot_clear_nulls(sk, prot->obj_size);
1602 	} else
1603 		sk = kmalloc(prot->obj_size, priority);
1604 
1605 	if (sk != NULL) {
1606 		if (security_sk_alloc(sk, family, priority))
1607 			goto out_free;
1608 
1609 		if (!try_module_get(prot->owner))
1610 			goto out_free_sec;
1611 		sk_tx_queue_clear(sk);
1612 	}
1613 
1614 	return sk;
1615 
1616 out_free_sec:
1617 	security_sk_free(sk);
1618 out_free:
1619 	if (slab != NULL)
1620 		kmem_cache_free(slab, sk);
1621 	else
1622 		kfree(sk);
1623 	return NULL;
1624 }
1625 
1626 static void sk_prot_free(struct proto *prot, struct sock *sk)
1627 {
1628 	struct kmem_cache *slab;
1629 	struct module *owner;
1630 
1631 	owner = prot->owner;
1632 	slab = prot->slab;
1633 
1634 	cgroup_sk_free(&sk->sk_cgrp_data);
1635 	mem_cgroup_sk_free(sk);
1636 	security_sk_free(sk);
1637 	if (slab != NULL)
1638 		kmem_cache_free(slab, sk);
1639 	else
1640 		kfree(sk);
1641 	module_put(owner);
1642 }
1643 
1644 /**
1645  *	sk_alloc - All socket objects are allocated here
1646  *	@net: the applicable net namespace
1647  *	@family: protocol family
1648  *	@priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
1649  *	@prot: struct proto associated with this new sock instance
1650  *	@kern: is this to be a kernel socket?
1651  */
1652 struct sock *sk_alloc(struct net *net, int family, gfp_t priority,
1653 		      struct proto *prot, int kern)
1654 {
1655 	struct sock *sk;
1656 
1657 	sk = sk_prot_alloc(prot, priority | __GFP_ZERO, family);
1658 	if (sk) {
1659 		sk->sk_family = family;
1660 		/*
1661 		 * See comment in struct sock definition to understand
1662 		 * why we need sk_prot_creator -acme
1663 		 */
1664 		sk->sk_prot = sk->sk_prot_creator = prot;
1665 		sk->sk_kern_sock = kern;
1666 		sock_lock_init(sk);
1667 		sk->sk_net_refcnt = kern ? 0 : 1;
1668 		if (likely(sk->sk_net_refcnt)) {
1669 			get_net(net);
1670 			sock_inuse_add(net, 1);
1671 		}
1672 
1673 		sock_net_set(sk, net);
1674 		refcount_set(&sk->sk_wmem_alloc, 1);
1675 
1676 		mem_cgroup_sk_alloc(sk);
1677 		cgroup_sk_alloc(&sk->sk_cgrp_data);
1678 		sock_update_classid(&sk->sk_cgrp_data);
1679 		sock_update_netprioidx(&sk->sk_cgrp_data);
1680 	}
1681 
1682 	return sk;
1683 }
1684 EXPORT_SYMBOL(sk_alloc);
1685 
1686 /* Sockets having SOCK_RCU_FREE will call this function after one RCU
1687  * grace period. This is the case for UDP sockets and TCP listeners.
1688  */
1689 static void __sk_destruct(struct rcu_head *head)
1690 {
1691 	struct sock *sk = container_of(head, struct sock, sk_rcu);
1692 	struct sk_filter *filter;
1693 
1694 	if (sk->sk_destruct)
1695 		sk->sk_destruct(sk);
1696 
1697 	filter = rcu_dereference_check(sk->sk_filter,
1698 				       refcount_read(&sk->sk_wmem_alloc) == 0);
1699 	if (filter) {
1700 		sk_filter_uncharge(sk, filter);
1701 		RCU_INIT_POINTER(sk->sk_filter, NULL);
1702 	}
1703 
1704 	sock_disable_timestamp(sk, SK_FLAGS_TIMESTAMP);
1705 
1706 #ifdef CONFIG_BPF_SYSCALL
1707 	bpf_sk_storage_free(sk);
1708 #endif
1709 
1710 	if (atomic_read(&sk->sk_omem_alloc))
1711 		pr_debug("%s: optmem leakage (%d bytes) detected\n",
1712 			 __func__, atomic_read(&sk->sk_omem_alloc));
1713 
1714 	if (sk->sk_frag.page) {
1715 		put_page(sk->sk_frag.page);
1716 		sk->sk_frag.page = NULL;
1717 	}
1718 
1719 	if (sk->sk_peer_cred)
1720 		put_cred(sk->sk_peer_cred);
1721 	put_pid(sk->sk_peer_pid);
1722 	if (likely(sk->sk_net_refcnt))
1723 		put_net(sock_net(sk));
1724 	sk_prot_free(sk->sk_prot_creator, sk);
1725 }
1726 
1727 void sk_destruct(struct sock *sk)
1728 {
1729 	bool use_call_rcu = sock_flag(sk, SOCK_RCU_FREE);
1730 
1731 	if (rcu_access_pointer(sk->sk_reuseport_cb)) {
1732 		reuseport_detach_sock(sk);
1733 		use_call_rcu = true;
1734 	}
1735 
1736 	if (use_call_rcu)
1737 		call_rcu(&sk->sk_rcu, __sk_destruct);
1738 	else
1739 		__sk_destruct(&sk->sk_rcu);
1740 }
1741 
1742 static void __sk_free(struct sock *sk)
1743 {
1744 	if (likely(sk->sk_net_refcnt))
1745 		sock_inuse_add(sock_net(sk), -1);
1746 
1747 	if (unlikely(sk->sk_net_refcnt && sock_diag_has_destroy_listeners(sk)))
1748 		sock_diag_broadcast_destroy(sk);
1749 	else
1750 		sk_destruct(sk);
1751 }
1752 
1753 void sk_free(struct sock *sk)
1754 {
1755 	/*
1756 	 * We subtract one from sk_wmem_alloc and can know if
1757 	 * some packets are still in some tx queue.
1758 	 * If not null, sock_wfree() will call __sk_free(sk) later
1759 	 */
1760 	if (refcount_dec_and_test(&sk->sk_wmem_alloc))
1761 		__sk_free(sk);
1762 }
1763 EXPORT_SYMBOL(sk_free);
1764 
1765 static void sk_init_common(struct sock *sk)
1766 {
1767 	skb_queue_head_init(&sk->sk_receive_queue);
1768 	skb_queue_head_init(&sk->sk_write_queue);
1769 	skb_queue_head_init(&sk->sk_error_queue);
1770 
1771 	rwlock_init(&sk->sk_callback_lock);
1772 	lockdep_set_class_and_name(&sk->sk_receive_queue.lock,
1773 			af_rlock_keys + sk->sk_family,
1774 			af_family_rlock_key_strings[sk->sk_family]);
1775 	lockdep_set_class_and_name(&sk->sk_write_queue.lock,
1776 			af_wlock_keys + sk->sk_family,
1777 			af_family_wlock_key_strings[sk->sk_family]);
1778 	lockdep_set_class_and_name(&sk->sk_error_queue.lock,
1779 			af_elock_keys + sk->sk_family,
1780 			af_family_elock_key_strings[sk->sk_family]);
1781 	lockdep_set_class_and_name(&sk->sk_callback_lock,
1782 			af_callback_keys + sk->sk_family,
1783 			af_family_clock_key_strings[sk->sk_family]);
1784 }
1785 
1786 /**
1787  *	sk_clone_lock - clone a socket, and lock its clone
1788  *	@sk: the socket to clone
1789  *	@priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
1790  *
1791  *	Caller must unlock socket even in error path (bh_unlock_sock(newsk))
1792  */
1793 struct sock *sk_clone_lock(const struct sock *sk, const gfp_t priority)
1794 {
1795 	struct sock *newsk;
1796 	bool is_charged = true;
1797 
1798 	newsk = sk_prot_alloc(sk->sk_prot, priority, sk->sk_family);
1799 	if (newsk != NULL) {
1800 		struct sk_filter *filter;
1801 
1802 		sock_copy(newsk, sk);
1803 
1804 		newsk->sk_prot_creator = sk->sk_prot;
1805 
1806 		/* SANITY */
1807 		if (likely(newsk->sk_net_refcnt))
1808 			get_net(sock_net(newsk));
1809 		sk_node_init(&newsk->sk_node);
1810 		sock_lock_init(newsk);
1811 		bh_lock_sock(newsk);
1812 		newsk->sk_backlog.head	= newsk->sk_backlog.tail = NULL;
1813 		newsk->sk_backlog.len = 0;
1814 
1815 		atomic_set(&newsk->sk_rmem_alloc, 0);
1816 		/*
1817 		 * sk_wmem_alloc set to one (see sk_free() and sock_wfree())
1818 		 */
1819 		refcount_set(&newsk->sk_wmem_alloc, 1);
1820 		atomic_set(&newsk->sk_omem_alloc, 0);
1821 		sk_init_common(newsk);
1822 
1823 		newsk->sk_dst_cache	= NULL;
1824 		newsk->sk_dst_pending_confirm = 0;
1825 		newsk->sk_wmem_queued	= 0;
1826 		newsk->sk_forward_alloc = 0;
1827 		atomic_set(&newsk->sk_drops, 0);
1828 		newsk->sk_send_head	= NULL;
1829 		newsk->sk_userlocks	= sk->sk_userlocks & ~SOCK_BINDPORT_LOCK;
1830 		atomic_set(&newsk->sk_zckey, 0);
1831 
1832 		sock_reset_flag(newsk, SOCK_DONE);
1833 		mem_cgroup_sk_alloc(newsk);
1834 		cgroup_sk_alloc(&newsk->sk_cgrp_data);
1835 
1836 		rcu_read_lock();
1837 		filter = rcu_dereference(sk->sk_filter);
1838 		if (filter != NULL)
1839 			/* though it's an empty new sock, the charging may fail
1840 			 * if sysctl_optmem_max was changed between creation of
1841 			 * original socket and cloning
1842 			 */
1843 			is_charged = sk_filter_charge(newsk, filter);
1844 		RCU_INIT_POINTER(newsk->sk_filter, filter);
1845 		rcu_read_unlock();
1846 
1847 		if (unlikely(!is_charged || xfrm_sk_clone_policy(newsk, sk))) {
1848 			/* We need to make sure that we don't uncharge the new
1849 			 * socket if we couldn't charge it in the first place
1850 			 * as otherwise we uncharge the parent's filter.
1851 			 */
1852 			if (!is_charged)
1853 				RCU_INIT_POINTER(newsk->sk_filter, NULL);
1854 			sk_free_unlock_clone(newsk);
1855 			newsk = NULL;
1856 			goto out;
1857 		}
1858 		RCU_INIT_POINTER(newsk->sk_reuseport_cb, NULL);
1859 
1860 		if (bpf_sk_storage_clone(sk, newsk)) {
1861 			sk_free_unlock_clone(newsk);
1862 			newsk = NULL;
1863 			goto out;
1864 		}
1865 
1866 		newsk->sk_err	   = 0;
1867 		newsk->sk_err_soft = 0;
1868 		newsk->sk_priority = 0;
1869 		newsk->sk_incoming_cpu = raw_smp_processor_id();
1870 		if (likely(newsk->sk_net_refcnt))
1871 			sock_inuse_add(sock_net(newsk), 1);
1872 
1873 		/*
1874 		 * Before updating sk_refcnt, we must commit prior changes to memory
1875 		 * (Documentation/RCU/rculist_nulls.txt for details)
1876 		 */
1877 		smp_wmb();
1878 		refcount_set(&newsk->sk_refcnt, 2);
1879 
1880 		/*
1881 		 * Increment the counter in the same struct proto as the master
1882 		 * sock (sk_refcnt_debug_inc uses newsk->sk_prot->socks, that
1883 		 * is the same as sk->sk_prot->socks, as this field was copied
1884 		 * with memcpy).
1885 		 *
1886 		 * This _changes_ the previous behaviour, where
1887 		 * tcp_create_openreq_child always was incrementing the
1888 		 * equivalent to tcp_prot->socks (inet_sock_nr), so this have
1889 		 * to be taken into account in all callers. -acme
1890 		 */
1891 		sk_refcnt_debug_inc(newsk);
1892 		sk_set_socket(newsk, NULL);
1893 		RCU_INIT_POINTER(newsk->sk_wq, NULL);
1894 
1895 		if (newsk->sk_prot->sockets_allocated)
1896 			sk_sockets_allocated_inc(newsk);
1897 
1898 		if (sock_needs_netstamp(sk) &&
1899 		    newsk->sk_flags & SK_FLAGS_TIMESTAMP)
1900 			net_enable_timestamp();
1901 	}
1902 out:
1903 	return newsk;
1904 }
1905 EXPORT_SYMBOL_GPL(sk_clone_lock);
1906 
1907 void sk_free_unlock_clone(struct sock *sk)
1908 {
1909 	/* It is still raw copy of parent, so invalidate
1910 	 * destructor and make plain sk_free() */
1911 	sk->sk_destruct = NULL;
1912 	bh_unlock_sock(sk);
1913 	sk_free(sk);
1914 }
1915 EXPORT_SYMBOL_GPL(sk_free_unlock_clone);
1916 
1917 void sk_setup_caps(struct sock *sk, struct dst_entry *dst)
1918 {
1919 	u32 max_segs = 1;
1920 
1921 	sk_dst_set(sk, dst);
1922 	sk->sk_route_caps = dst->dev->features | sk->sk_route_forced_caps;
1923 	if (sk->sk_route_caps & NETIF_F_GSO)
1924 		sk->sk_route_caps |= NETIF_F_GSO_SOFTWARE;
1925 	sk->sk_route_caps &= ~sk->sk_route_nocaps;
1926 	if (sk_can_gso(sk)) {
1927 		if (dst->header_len && !xfrm_dst_offload_ok(dst)) {
1928 			sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
1929 		} else {
1930 			sk->sk_route_caps |= NETIF_F_SG | NETIF_F_HW_CSUM;
1931 			sk->sk_gso_max_size = dst->dev->gso_max_size;
1932 			max_segs = max_t(u32, dst->dev->gso_max_segs, 1);
1933 		}
1934 	}
1935 	sk->sk_gso_max_segs = max_segs;
1936 }
1937 EXPORT_SYMBOL_GPL(sk_setup_caps);
1938 
1939 /*
1940  *	Simple resource managers for sockets.
1941  */
1942 
1943 
1944 /*
1945  * Write buffer destructor automatically called from kfree_skb.
1946  */
1947 void sock_wfree(struct sk_buff *skb)
1948 {
1949 	struct sock *sk = skb->sk;
1950 	unsigned int len = skb->truesize;
1951 
1952 	if (!sock_flag(sk, SOCK_USE_WRITE_QUEUE)) {
1953 		/*
1954 		 * Keep a reference on sk_wmem_alloc, this will be released
1955 		 * after sk_write_space() call
1956 		 */
1957 		WARN_ON(refcount_sub_and_test(len - 1, &sk->sk_wmem_alloc));
1958 		sk->sk_write_space(sk);
1959 		len = 1;
1960 	}
1961 	/*
1962 	 * if sk_wmem_alloc reaches 0, we must finish what sk_free()
1963 	 * could not do because of in-flight packets
1964 	 */
1965 	if (refcount_sub_and_test(len, &sk->sk_wmem_alloc))
1966 		__sk_free(sk);
1967 }
1968 EXPORT_SYMBOL(sock_wfree);
1969 
1970 /* This variant of sock_wfree() is used by TCP,
1971  * since it sets SOCK_USE_WRITE_QUEUE.
1972  */
1973 void __sock_wfree(struct sk_buff *skb)
1974 {
1975 	struct sock *sk = skb->sk;
1976 
1977 	if (refcount_sub_and_test(skb->truesize, &sk->sk_wmem_alloc))
1978 		__sk_free(sk);
1979 }
1980 
1981 void skb_set_owner_w(struct sk_buff *skb, struct sock *sk)
1982 {
1983 	skb_orphan(skb);
1984 	skb->sk = sk;
1985 #ifdef CONFIG_INET
1986 	if (unlikely(!sk_fullsock(sk))) {
1987 		skb->destructor = sock_edemux;
1988 		sock_hold(sk);
1989 		return;
1990 	}
1991 #endif
1992 	skb->destructor = sock_wfree;
1993 	skb_set_hash_from_sk(skb, sk);
1994 	/*
1995 	 * We used to take a refcount on sk, but following operation
1996 	 * is enough to guarantee sk_free() wont free this sock until
1997 	 * all in-flight packets are completed
1998 	 */
1999 	refcount_add(skb->truesize, &sk->sk_wmem_alloc);
2000 }
2001 EXPORT_SYMBOL(skb_set_owner_w);
2002 
2003 static bool can_skb_orphan_partial(const struct sk_buff *skb)
2004 {
2005 #ifdef CONFIG_TLS_DEVICE
2006 	/* Drivers depend on in-order delivery for crypto offload,
2007 	 * partial orphan breaks out-of-order-OK logic.
2008 	 */
2009 	if (skb->decrypted)
2010 		return false;
2011 #endif
2012 	return (skb->destructor == sock_wfree ||
2013 		(IS_ENABLED(CONFIG_INET) && skb->destructor == tcp_wfree));
2014 }
2015 
2016 /* This helper is used by netem, as it can hold packets in its
2017  * delay queue. We want to allow the owner socket to send more
2018  * packets, as if they were already TX completed by a typical driver.
2019  * But we also want to keep skb->sk set because some packet schedulers
2020  * rely on it (sch_fq for example).
2021  */
2022 void skb_orphan_partial(struct sk_buff *skb)
2023 {
2024 	if (skb_is_tcp_pure_ack(skb))
2025 		return;
2026 
2027 	if (can_skb_orphan_partial(skb)) {
2028 		struct sock *sk = skb->sk;
2029 
2030 		if (refcount_inc_not_zero(&sk->sk_refcnt)) {
2031 			WARN_ON(refcount_sub_and_test(skb->truesize, &sk->sk_wmem_alloc));
2032 			skb->destructor = sock_efree;
2033 		}
2034 	} else {
2035 		skb_orphan(skb);
2036 	}
2037 }
2038 EXPORT_SYMBOL(skb_orphan_partial);
2039 
2040 /*
2041  * Read buffer destructor automatically called from kfree_skb.
2042  */
2043 void sock_rfree(struct sk_buff *skb)
2044 {
2045 	struct sock *sk = skb->sk;
2046 	unsigned int len = skb->truesize;
2047 
2048 	atomic_sub(len, &sk->sk_rmem_alloc);
2049 	sk_mem_uncharge(sk, len);
2050 }
2051 EXPORT_SYMBOL(sock_rfree);
2052 
2053 /*
2054  * Buffer destructor for skbs that are not used directly in read or write
2055  * path, e.g. for error handler skbs. Automatically called from kfree_skb.
2056  */
2057 void sock_efree(struct sk_buff *skb)
2058 {
2059 	sock_put(skb->sk);
2060 }
2061 EXPORT_SYMBOL(sock_efree);
2062 
2063 kuid_t sock_i_uid(struct sock *sk)
2064 {
2065 	kuid_t uid;
2066 
2067 	read_lock_bh(&sk->sk_callback_lock);
2068 	uid = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_uid : GLOBAL_ROOT_UID;
2069 	read_unlock_bh(&sk->sk_callback_lock);
2070 	return uid;
2071 }
2072 EXPORT_SYMBOL(sock_i_uid);
2073 
2074 unsigned long sock_i_ino(struct sock *sk)
2075 {
2076 	unsigned long ino;
2077 
2078 	read_lock_bh(&sk->sk_callback_lock);
2079 	ino = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_ino : 0;
2080 	read_unlock_bh(&sk->sk_callback_lock);
2081 	return ino;
2082 }
2083 EXPORT_SYMBOL(sock_i_ino);
2084 
2085 /*
2086  * Allocate a skb from the socket's send buffer.
2087  */
2088 struct sk_buff *sock_wmalloc(struct sock *sk, unsigned long size, int force,
2089 			     gfp_t priority)
2090 {
2091 	if (force ||
2092 	    refcount_read(&sk->sk_wmem_alloc) < READ_ONCE(sk->sk_sndbuf)) {
2093 		struct sk_buff *skb = alloc_skb(size, priority);
2094 
2095 		if (skb) {
2096 			skb_set_owner_w(skb, sk);
2097 			return skb;
2098 		}
2099 	}
2100 	return NULL;
2101 }
2102 EXPORT_SYMBOL(sock_wmalloc);
2103 
2104 static void sock_ofree(struct sk_buff *skb)
2105 {
2106 	struct sock *sk = skb->sk;
2107 
2108 	atomic_sub(skb->truesize, &sk->sk_omem_alloc);
2109 }
2110 
2111 struct sk_buff *sock_omalloc(struct sock *sk, unsigned long size,
2112 			     gfp_t priority)
2113 {
2114 	struct sk_buff *skb;
2115 
2116 	/* small safe race: SKB_TRUESIZE may differ from final skb->truesize */
2117 	if (atomic_read(&sk->sk_omem_alloc) + SKB_TRUESIZE(size) >
2118 	    sysctl_optmem_max)
2119 		return NULL;
2120 
2121 	skb = alloc_skb(size, priority);
2122 	if (!skb)
2123 		return NULL;
2124 
2125 	atomic_add(skb->truesize, &sk->sk_omem_alloc);
2126 	skb->sk = sk;
2127 	skb->destructor = sock_ofree;
2128 	return skb;
2129 }
2130 
2131 /*
2132  * Allocate a memory block from the socket's option memory buffer.
2133  */
2134 void *sock_kmalloc(struct sock *sk, int size, gfp_t priority)
2135 {
2136 	if ((unsigned int)size <= sysctl_optmem_max &&
2137 	    atomic_read(&sk->sk_omem_alloc) + size < sysctl_optmem_max) {
2138 		void *mem;
2139 		/* First do the add, to avoid the race if kmalloc
2140 		 * might sleep.
2141 		 */
2142 		atomic_add(size, &sk->sk_omem_alloc);
2143 		mem = kmalloc(size, priority);
2144 		if (mem)
2145 			return mem;
2146 		atomic_sub(size, &sk->sk_omem_alloc);
2147 	}
2148 	return NULL;
2149 }
2150 EXPORT_SYMBOL(sock_kmalloc);
2151 
2152 /* Free an option memory block. Note, we actually want the inline
2153  * here as this allows gcc to detect the nullify and fold away the
2154  * condition entirely.
2155  */
2156 static inline void __sock_kfree_s(struct sock *sk, void *mem, int size,
2157 				  const bool nullify)
2158 {
2159 	if (WARN_ON_ONCE(!mem))
2160 		return;
2161 	if (nullify)
2162 		kzfree(mem);
2163 	else
2164 		kfree(mem);
2165 	atomic_sub(size, &sk->sk_omem_alloc);
2166 }
2167 
2168 void sock_kfree_s(struct sock *sk, void *mem, int size)
2169 {
2170 	__sock_kfree_s(sk, mem, size, false);
2171 }
2172 EXPORT_SYMBOL(sock_kfree_s);
2173 
2174 void sock_kzfree_s(struct sock *sk, void *mem, int size)
2175 {
2176 	__sock_kfree_s(sk, mem, size, true);
2177 }
2178 EXPORT_SYMBOL(sock_kzfree_s);
2179 
2180 /* It is almost wait_for_tcp_memory minus release_sock/lock_sock.
2181    I think, these locks should be removed for datagram sockets.
2182  */
2183 static long sock_wait_for_wmem(struct sock *sk, long timeo)
2184 {
2185 	DEFINE_WAIT(wait);
2186 
2187 	sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
2188 	for (;;) {
2189 		if (!timeo)
2190 			break;
2191 		if (signal_pending(current))
2192 			break;
2193 		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
2194 		prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
2195 		if (refcount_read(&sk->sk_wmem_alloc) < READ_ONCE(sk->sk_sndbuf))
2196 			break;
2197 		if (sk->sk_shutdown & SEND_SHUTDOWN)
2198 			break;
2199 		if (sk->sk_err)
2200 			break;
2201 		timeo = schedule_timeout(timeo);
2202 	}
2203 	finish_wait(sk_sleep(sk), &wait);
2204 	return timeo;
2205 }
2206 
2207 
2208 /*
2209  *	Generic send/receive buffer handlers
2210  */
2211 
2212 struct sk_buff *sock_alloc_send_pskb(struct sock *sk, unsigned long header_len,
2213 				     unsigned long data_len, int noblock,
2214 				     int *errcode, int max_page_order)
2215 {
2216 	struct sk_buff *skb;
2217 	long timeo;
2218 	int err;
2219 
2220 	timeo = sock_sndtimeo(sk, noblock);
2221 	for (;;) {
2222 		err = sock_error(sk);
2223 		if (err != 0)
2224 			goto failure;
2225 
2226 		err = -EPIPE;
2227 		if (sk->sk_shutdown & SEND_SHUTDOWN)
2228 			goto failure;
2229 
2230 		if (sk_wmem_alloc_get(sk) < READ_ONCE(sk->sk_sndbuf))
2231 			break;
2232 
2233 		sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
2234 		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
2235 		err = -EAGAIN;
2236 		if (!timeo)
2237 			goto failure;
2238 		if (signal_pending(current))
2239 			goto interrupted;
2240 		timeo = sock_wait_for_wmem(sk, timeo);
2241 	}
2242 	skb = alloc_skb_with_frags(header_len, data_len, max_page_order,
2243 				   errcode, sk->sk_allocation);
2244 	if (skb)
2245 		skb_set_owner_w(skb, sk);
2246 	return skb;
2247 
2248 interrupted:
2249 	err = sock_intr_errno(timeo);
2250 failure:
2251 	*errcode = err;
2252 	return NULL;
2253 }
2254 EXPORT_SYMBOL(sock_alloc_send_pskb);
2255 
2256 struct sk_buff *sock_alloc_send_skb(struct sock *sk, unsigned long size,
2257 				    int noblock, int *errcode)
2258 {
2259 	return sock_alloc_send_pskb(sk, size, 0, noblock, errcode, 0);
2260 }
2261 EXPORT_SYMBOL(sock_alloc_send_skb);
2262 
2263 int __sock_cmsg_send(struct sock *sk, struct msghdr *msg, struct cmsghdr *cmsg,
2264 		     struct sockcm_cookie *sockc)
2265 {
2266 	u32 tsflags;
2267 
2268 	switch (cmsg->cmsg_type) {
2269 	case SO_MARK:
2270 		if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
2271 			return -EPERM;
2272 		if (cmsg->cmsg_len != CMSG_LEN(sizeof(u32)))
2273 			return -EINVAL;
2274 		sockc->mark = *(u32 *)CMSG_DATA(cmsg);
2275 		break;
2276 	case SO_TIMESTAMPING_OLD:
2277 		if (cmsg->cmsg_len != CMSG_LEN(sizeof(u32)))
2278 			return -EINVAL;
2279 
2280 		tsflags = *(u32 *)CMSG_DATA(cmsg);
2281 		if (tsflags & ~SOF_TIMESTAMPING_TX_RECORD_MASK)
2282 			return -EINVAL;
2283 
2284 		sockc->tsflags &= ~SOF_TIMESTAMPING_TX_RECORD_MASK;
2285 		sockc->tsflags |= tsflags;
2286 		break;
2287 	case SCM_TXTIME:
2288 		if (!sock_flag(sk, SOCK_TXTIME))
2289 			return -EINVAL;
2290 		if (cmsg->cmsg_len != CMSG_LEN(sizeof(u64)))
2291 			return -EINVAL;
2292 		sockc->transmit_time = get_unaligned((u64 *)CMSG_DATA(cmsg));
2293 		break;
2294 	/* SCM_RIGHTS and SCM_CREDENTIALS are semantically in SOL_UNIX. */
2295 	case SCM_RIGHTS:
2296 	case SCM_CREDENTIALS:
2297 		break;
2298 	default:
2299 		return -EINVAL;
2300 	}
2301 	return 0;
2302 }
2303 EXPORT_SYMBOL(__sock_cmsg_send);
2304 
2305 int sock_cmsg_send(struct sock *sk, struct msghdr *msg,
2306 		   struct sockcm_cookie *sockc)
2307 {
2308 	struct cmsghdr *cmsg;
2309 	int ret;
2310 
2311 	for_each_cmsghdr(cmsg, msg) {
2312 		if (!CMSG_OK(msg, cmsg))
2313 			return -EINVAL;
2314 		if (cmsg->cmsg_level != SOL_SOCKET)
2315 			continue;
2316 		ret = __sock_cmsg_send(sk, msg, cmsg, sockc);
2317 		if (ret)
2318 			return ret;
2319 	}
2320 	return 0;
2321 }
2322 EXPORT_SYMBOL(sock_cmsg_send);
2323 
2324 static void sk_enter_memory_pressure(struct sock *sk)
2325 {
2326 	if (!sk->sk_prot->enter_memory_pressure)
2327 		return;
2328 
2329 	sk->sk_prot->enter_memory_pressure(sk);
2330 }
2331 
2332 static void sk_leave_memory_pressure(struct sock *sk)
2333 {
2334 	if (sk->sk_prot->leave_memory_pressure) {
2335 		sk->sk_prot->leave_memory_pressure(sk);
2336 	} else {
2337 		unsigned long *memory_pressure = sk->sk_prot->memory_pressure;
2338 
2339 		if (memory_pressure && READ_ONCE(*memory_pressure))
2340 			WRITE_ONCE(*memory_pressure, 0);
2341 	}
2342 }
2343 
2344 /* On 32bit arches, an skb frag is limited to 2^15 */
2345 #define SKB_FRAG_PAGE_ORDER	get_order(32768)
2346 DEFINE_STATIC_KEY_FALSE(net_high_order_alloc_disable_key);
2347 
2348 /**
2349  * skb_page_frag_refill - check that a page_frag contains enough room
2350  * @sz: minimum size of the fragment we want to get
2351  * @pfrag: pointer to page_frag
2352  * @gfp: priority for memory allocation
2353  *
2354  * Note: While this allocator tries to use high order pages, there is
2355  * no guarantee that allocations succeed. Therefore, @sz MUST be
2356  * less or equal than PAGE_SIZE.
2357  */
2358 bool skb_page_frag_refill(unsigned int sz, struct page_frag *pfrag, gfp_t gfp)
2359 {
2360 	if (pfrag->page) {
2361 		if (page_ref_count(pfrag->page) == 1) {
2362 			pfrag->offset = 0;
2363 			return true;
2364 		}
2365 		if (pfrag->offset + sz <= pfrag->size)
2366 			return true;
2367 		put_page(pfrag->page);
2368 	}
2369 
2370 	pfrag->offset = 0;
2371 	if (SKB_FRAG_PAGE_ORDER &&
2372 	    !static_branch_unlikely(&net_high_order_alloc_disable_key)) {
2373 		/* Avoid direct reclaim but allow kswapd to wake */
2374 		pfrag->page = alloc_pages((gfp & ~__GFP_DIRECT_RECLAIM) |
2375 					  __GFP_COMP | __GFP_NOWARN |
2376 					  __GFP_NORETRY,
2377 					  SKB_FRAG_PAGE_ORDER);
2378 		if (likely(pfrag->page)) {
2379 			pfrag->size = PAGE_SIZE << SKB_FRAG_PAGE_ORDER;
2380 			return true;
2381 		}
2382 	}
2383 	pfrag->page = alloc_page(gfp);
2384 	if (likely(pfrag->page)) {
2385 		pfrag->size = PAGE_SIZE;
2386 		return true;
2387 	}
2388 	return false;
2389 }
2390 EXPORT_SYMBOL(skb_page_frag_refill);
2391 
2392 bool sk_page_frag_refill(struct sock *sk, struct page_frag *pfrag)
2393 {
2394 	if (likely(skb_page_frag_refill(32U, pfrag, sk->sk_allocation)))
2395 		return true;
2396 
2397 	sk_enter_memory_pressure(sk);
2398 	sk_stream_moderate_sndbuf(sk);
2399 	return false;
2400 }
2401 EXPORT_SYMBOL(sk_page_frag_refill);
2402 
2403 static void __lock_sock(struct sock *sk)
2404 	__releases(&sk->sk_lock.slock)
2405 	__acquires(&sk->sk_lock.slock)
2406 {
2407 	DEFINE_WAIT(wait);
2408 
2409 	for (;;) {
2410 		prepare_to_wait_exclusive(&sk->sk_lock.wq, &wait,
2411 					TASK_UNINTERRUPTIBLE);
2412 		spin_unlock_bh(&sk->sk_lock.slock);
2413 		schedule();
2414 		spin_lock_bh(&sk->sk_lock.slock);
2415 		if (!sock_owned_by_user(sk))
2416 			break;
2417 	}
2418 	finish_wait(&sk->sk_lock.wq, &wait);
2419 }
2420 
2421 void __release_sock(struct sock *sk)
2422 	__releases(&sk->sk_lock.slock)
2423 	__acquires(&sk->sk_lock.slock)
2424 {
2425 	struct sk_buff *skb, *next;
2426 
2427 	while ((skb = sk->sk_backlog.head) != NULL) {
2428 		sk->sk_backlog.head = sk->sk_backlog.tail = NULL;
2429 
2430 		spin_unlock_bh(&sk->sk_lock.slock);
2431 
2432 		do {
2433 			next = skb->next;
2434 			prefetch(next);
2435 			WARN_ON_ONCE(skb_dst_is_noref(skb));
2436 			skb_mark_not_on_list(skb);
2437 			sk_backlog_rcv(sk, skb);
2438 
2439 			cond_resched();
2440 
2441 			skb = next;
2442 		} while (skb != NULL);
2443 
2444 		spin_lock_bh(&sk->sk_lock.slock);
2445 	}
2446 
2447 	/*
2448 	 * Doing the zeroing here guarantee we can not loop forever
2449 	 * while a wild producer attempts to flood us.
2450 	 */
2451 	sk->sk_backlog.len = 0;
2452 }
2453 
2454 void __sk_flush_backlog(struct sock *sk)
2455 {
2456 	spin_lock_bh(&sk->sk_lock.slock);
2457 	__release_sock(sk);
2458 	spin_unlock_bh(&sk->sk_lock.slock);
2459 }
2460 
2461 /**
2462  * sk_wait_data - wait for data to arrive at sk_receive_queue
2463  * @sk:    sock to wait on
2464  * @timeo: for how long
2465  * @skb:   last skb seen on sk_receive_queue
2466  *
2467  * Now socket state including sk->sk_err is changed only under lock,
2468  * hence we may omit checks after joining wait queue.
2469  * We check receive queue before schedule() only as optimization;
2470  * it is very likely that release_sock() added new data.
2471  */
2472 int sk_wait_data(struct sock *sk, long *timeo, const struct sk_buff *skb)
2473 {
2474 	DEFINE_WAIT_FUNC(wait, woken_wake_function);
2475 	int rc;
2476 
2477 	add_wait_queue(sk_sleep(sk), &wait);
2478 	sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
2479 	rc = sk_wait_event(sk, timeo, skb_peek_tail(&sk->sk_receive_queue) != skb, &wait);
2480 	sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
2481 	remove_wait_queue(sk_sleep(sk), &wait);
2482 	return rc;
2483 }
2484 EXPORT_SYMBOL(sk_wait_data);
2485 
2486 /**
2487  *	__sk_mem_raise_allocated - increase memory_allocated
2488  *	@sk: socket
2489  *	@size: memory size to allocate
2490  *	@amt: pages to allocate
2491  *	@kind: allocation type
2492  *
2493  *	Similar to __sk_mem_schedule(), but does not update sk_forward_alloc
2494  */
2495 int __sk_mem_raise_allocated(struct sock *sk, int size, int amt, int kind)
2496 {
2497 	struct proto *prot = sk->sk_prot;
2498 	long allocated = sk_memory_allocated_add(sk, amt);
2499 	bool charged = true;
2500 
2501 	if (mem_cgroup_sockets_enabled && sk->sk_memcg &&
2502 	    !(charged = mem_cgroup_charge_skmem(sk->sk_memcg, amt)))
2503 		goto suppress_allocation;
2504 
2505 	/* Under limit. */
2506 	if (allocated <= sk_prot_mem_limits(sk, 0)) {
2507 		sk_leave_memory_pressure(sk);
2508 		return 1;
2509 	}
2510 
2511 	/* Under pressure. */
2512 	if (allocated > sk_prot_mem_limits(sk, 1))
2513 		sk_enter_memory_pressure(sk);
2514 
2515 	/* Over hard limit. */
2516 	if (allocated > sk_prot_mem_limits(sk, 2))
2517 		goto suppress_allocation;
2518 
2519 	/* guarantee minimum buffer size under pressure */
2520 	if (kind == SK_MEM_RECV) {
2521 		if (atomic_read(&sk->sk_rmem_alloc) < sk_get_rmem0(sk, prot))
2522 			return 1;
2523 
2524 	} else { /* SK_MEM_SEND */
2525 		int wmem0 = sk_get_wmem0(sk, prot);
2526 
2527 		if (sk->sk_type == SOCK_STREAM) {
2528 			if (sk->sk_wmem_queued < wmem0)
2529 				return 1;
2530 		} else if (refcount_read(&sk->sk_wmem_alloc) < wmem0) {
2531 				return 1;
2532 		}
2533 	}
2534 
2535 	if (sk_has_memory_pressure(sk)) {
2536 		u64 alloc;
2537 
2538 		if (!sk_under_memory_pressure(sk))
2539 			return 1;
2540 		alloc = sk_sockets_allocated_read_positive(sk);
2541 		if (sk_prot_mem_limits(sk, 2) > alloc *
2542 		    sk_mem_pages(sk->sk_wmem_queued +
2543 				 atomic_read(&sk->sk_rmem_alloc) +
2544 				 sk->sk_forward_alloc))
2545 			return 1;
2546 	}
2547 
2548 suppress_allocation:
2549 
2550 	if (kind == SK_MEM_SEND && sk->sk_type == SOCK_STREAM) {
2551 		sk_stream_moderate_sndbuf(sk);
2552 
2553 		/* Fail only if socket is _under_ its sndbuf.
2554 		 * In this case we cannot block, so that we have to fail.
2555 		 */
2556 		if (sk->sk_wmem_queued + size >= sk->sk_sndbuf)
2557 			return 1;
2558 	}
2559 
2560 	if (kind == SK_MEM_SEND || (kind == SK_MEM_RECV && charged))
2561 		trace_sock_exceed_buf_limit(sk, prot, allocated, kind);
2562 
2563 	sk_memory_allocated_sub(sk, amt);
2564 
2565 	if (mem_cgroup_sockets_enabled && sk->sk_memcg)
2566 		mem_cgroup_uncharge_skmem(sk->sk_memcg, amt);
2567 
2568 	return 0;
2569 }
2570 EXPORT_SYMBOL(__sk_mem_raise_allocated);
2571 
2572 /**
2573  *	__sk_mem_schedule - increase sk_forward_alloc and memory_allocated
2574  *	@sk: socket
2575  *	@size: memory size to allocate
2576  *	@kind: allocation type
2577  *
2578  *	If kind is SK_MEM_SEND, it means wmem allocation. Otherwise it means
2579  *	rmem allocation. This function assumes that protocols which have
2580  *	memory_pressure use sk_wmem_queued as write buffer accounting.
2581  */
2582 int __sk_mem_schedule(struct sock *sk, int size, int kind)
2583 {
2584 	int ret, amt = sk_mem_pages(size);
2585 
2586 	sk->sk_forward_alloc += amt << SK_MEM_QUANTUM_SHIFT;
2587 	ret = __sk_mem_raise_allocated(sk, size, amt, kind);
2588 	if (!ret)
2589 		sk->sk_forward_alloc -= amt << SK_MEM_QUANTUM_SHIFT;
2590 	return ret;
2591 }
2592 EXPORT_SYMBOL(__sk_mem_schedule);
2593 
2594 /**
2595  *	__sk_mem_reduce_allocated - reclaim memory_allocated
2596  *	@sk: socket
2597  *	@amount: number of quanta
2598  *
2599  *	Similar to __sk_mem_reclaim(), but does not update sk_forward_alloc
2600  */
2601 void __sk_mem_reduce_allocated(struct sock *sk, int amount)
2602 {
2603 	sk_memory_allocated_sub(sk, amount);
2604 
2605 	if (mem_cgroup_sockets_enabled && sk->sk_memcg)
2606 		mem_cgroup_uncharge_skmem(sk->sk_memcg, amount);
2607 
2608 	if (sk_under_memory_pressure(sk) &&
2609 	    (sk_memory_allocated(sk) < sk_prot_mem_limits(sk, 0)))
2610 		sk_leave_memory_pressure(sk);
2611 }
2612 EXPORT_SYMBOL(__sk_mem_reduce_allocated);
2613 
2614 /**
2615  *	__sk_mem_reclaim - reclaim sk_forward_alloc and memory_allocated
2616  *	@sk: socket
2617  *	@amount: number of bytes (rounded down to a SK_MEM_QUANTUM multiple)
2618  */
2619 void __sk_mem_reclaim(struct sock *sk, int amount)
2620 {
2621 	amount >>= SK_MEM_QUANTUM_SHIFT;
2622 	sk->sk_forward_alloc -= amount << SK_MEM_QUANTUM_SHIFT;
2623 	__sk_mem_reduce_allocated(sk, amount);
2624 }
2625 EXPORT_SYMBOL(__sk_mem_reclaim);
2626 
2627 int sk_set_peek_off(struct sock *sk, int val)
2628 {
2629 	sk->sk_peek_off = val;
2630 	return 0;
2631 }
2632 EXPORT_SYMBOL_GPL(sk_set_peek_off);
2633 
2634 /*
2635  * Set of default routines for initialising struct proto_ops when
2636  * the protocol does not support a particular function. In certain
2637  * cases where it makes no sense for a protocol to have a "do nothing"
2638  * function, some default processing is provided.
2639  */
2640 
2641 int sock_no_bind(struct socket *sock, struct sockaddr *saddr, int len)
2642 {
2643 	return -EOPNOTSUPP;
2644 }
2645 EXPORT_SYMBOL(sock_no_bind);
2646 
2647 int sock_no_connect(struct socket *sock, struct sockaddr *saddr,
2648 		    int len, int flags)
2649 {
2650 	return -EOPNOTSUPP;
2651 }
2652 EXPORT_SYMBOL(sock_no_connect);
2653 
2654 int sock_no_socketpair(struct socket *sock1, struct socket *sock2)
2655 {
2656 	return -EOPNOTSUPP;
2657 }
2658 EXPORT_SYMBOL(sock_no_socketpair);
2659 
2660 int sock_no_accept(struct socket *sock, struct socket *newsock, int flags,
2661 		   bool kern)
2662 {
2663 	return -EOPNOTSUPP;
2664 }
2665 EXPORT_SYMBOL(sock_no_accept);
2666 
2667 int sock_no_getname(struct socket *sock, struct sockaddr *saddr,
2668 		    int peer)
2669 {
2670 	return -EOPNOTSUPP;
2671 }
2672 EXPORT_SYMBOL(sock_no_getname);
2673 
2674 int sock_no_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
2675 {
2676 	return -EOPNOTSUPP;
2677 }
2678 EXPORT_SYMBOL(sock_no_ioctl);
2679 
2680 int sock_no_listen(struct socket *sock, int backlog)
2681 {
2682 	return -EOPNOTSUPP;
2683 }
2684 EXPORT_SYMBOL(sock_no_listen);
2685 
2686 int sock_no_shutdown(struct socket *sock, int how)
2687 {
2688 	return -EOPNOTSUPP;
2689 }
2690 EXPORT_SYMBOL(sock_no_shutdown);
2691 
2692 int sock_no_setsockopt(struct socket *sock, int level, int optname,
2693 		    char __user *optval, unsigned int optlen)
2694 {
2695 	return -EOPNOTSUPP;
2696 }
2697 EXPORT_SYMBOL(sock_no_setsockopt);
2698 
2699 int sock_no_getsockopt(struct socket *sock, int level, int optname,
2700 		    char __user *optval, int __user *optlen)
2701 {
2702 	return -EOPNOTSUPP;
2703 }
2704 EXPORT_SYMBOL(sock_no_getsockopt);
2705 
2706 int sock_no_sendmsg(struct socket *sock, struct msghdr *m, size_t len)
2707 {
2708 	return -EOPNOTSUPP;
2709 }
2710 EXPORT_SYMBOL(sock_no_sendmsg);
2711 
2712 int sock_no_sendmsg_locked(struct sock *sk, struct msghdr *m, size_t len)
2713 {
2714 	return -EOPNOTSUPP;
2715 }
2716 EXPORT_SYMBOL(sock_no_sendmsg_locked);
2717 
2718 int sock_no_recvmsg(struct socket *sock, struct msghdr *m, size_t len,
2719 		    int flags)
2720 {
2721 	return -EOPNOTSUPP;
2722 }
2723 EXPORT_SYMBOL(sock_no_recvmsg);
2724 
2725 int sock_no_mmap(struct file *file, struct socket *sock, struct vm_area_struct *vma)
2726 {
2727 	/* Mirror missing mmap method error code */
2728 	return -ENODEV;
2729 }
2730 EXPORT_SYMBOL(sock_no_mmap);
2731 
2732 ssize_t sock_no_sendpage(struct socket *sock, struct page *page, int offset, size_t size, int flags)
2733 {
2734 	ssize_t res;
2735 	struct msghdr msg = {.msg_flags = flags};
2736 	struct kvec iov;
2737 	char *kaddr = kmap(page);
2738 	iov.iov_base = kaddr + offset;
2739 	iov.iov_len = size;
2740 	res = kernel_sendmsg(sock, &msg, &iov, 1, size);
2741 	kunmap(page);
2742 	return res;
2743 }
2744 EXPORT_SYMBOL(sock_no_sendpage);
2745 
2746 ssize_t sock_no_sendpage_locked(struct sock *sk, struct page *page,
2747 				int offset, size_t size, int flags)
2748 {
2749 	ssize_t res;
2750 	struct msghdr msg = {.msg_flags = flags};
2751 	struct kvec iov;
2752 	char *kaddr = kmap(page);
2753 
2754 	iov.iov_base = kaddr + offset;
2755 	iov.iov_len = size;
2756 	res = kernel_sendmsg_locked(sk, &msg, &iov, 1, size);
2757 	kunmap(page);
2758 	return res;
2759 }
2760 EXPORT_SYMBOL(sock_no_sendpage_locked);
2761 
2762 /*
2763  *	Default Socket Callbacks
2764  */
2765 
2766 static void sock_def_wakeup(struct sock *sk)
2767 {
2768 	struct socket_wq *wq;
2769 
2770 	rcu_read_lock();
2771 	wq = rcu_dereference(sk->sk_wq);
2772 	if (skwq_has_sleeper(wq))
2773 		wake_up_interruptible_all(&wq->wait);
2774 	rcu_read_unlock();
2775 }
2776 
2777 static void sock_def_error_report(struct sock *sk)
2778 {
2779 	struct socket_wq *wq;
2780 
2781 	rcu_read_lock();
2782 	wq = rcu_dereference(sk->sk_wq);
2783 	if (skwq_has_sleeper(wq))
2784 		wake_up_interruptible_poll(&wq->wait, EPOLLERR);
2785 	sk_wake_async(sk, SOCK_WAKE_IO, POLL_ERR);
2786 	rcu_read_unlock();
2787 }
2788 
2789 static void sock_def_readable(struct sock *sk)
2790 {
2791 	struct socket_wq *wq;
2792 
2793 	rcu_read_lock();
2794 	wq = rcu_dereference(sk->sk_wq);
2795 	if (skwq_has_sleeper(wq))
2796 		wake_up_interruptible_sync_poll(&wq->wait, EPOLLIN | EPOLLPRI |
2797 						EPOLLRDNORM | EPOLLRDBAND);
2798 	sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
2799 	rcu_read_unlock();
2800 }
2801 
2802 static void sock_def_write_space(struct sock *sk)
2803 {
2804 	struct socket_wq *wq;
2805 
2806 	rcu_read_lock();
2807 
2808 	/* Do not wake up a writer until he can make "significant"
2809 	 * progress.  --DaveM
2810 	 */
2811 	if ((refcount_read(&sk->sk_wmem_alloc) << 1) <= READ_ONCE(sk->sk_sndbuf)) {
2812 		wq = rcu_dereference(sk->sk_wq);
2813 		if (skwq_has_sleeper(wq))
2814 			wake_up_interruptible_sync_poll(&wq->wait, EPOLLOUT |
2815 						EPOLLWRNORM | EPOLLWRBAND);
2816 
2817 		/* Should agree with poll, otherwise some programs break */
2818 		if (sock_writeable(sk))
2819 			sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
2820 	}
2821 
2822 	rcu_read_unlock();
2823 }
2824 
2825 static void sock_def_destruct(struct sock *sk)
2826 {
2827 }
2828 
2829 void sk_send_sigurg(struct sock *sk)
2830 {
2831 	if (sk->sk_socket && sk->sk_socket->file)
2832 		if (send_sigurg(&sk->sk_socket->file->f_owner))
2833 			sk_wake_async(sk, SOCK_WAKE_URG, POLL_PRI);
2834 }
2835 EXPORT_SYMBOL(sk_send_sigurg);
2836 
2837 void sk_reset_timer(struct sock *sk, struct timer_list* timer,
2838 		    unsigned long expires)
2839 {
2840 	if (!mod_timer(timer, expires))
2841 		sock_hold(sk);
2842 }
2843 EXPORT_SYMBOL(sk_reset_timer);
2844 
2845 void sk_stop_timer(struct sock *sk, struct timer_list* timer)
2846 {
2847 	if (del_timer(timer))
2848 		__sock_put(sk);
2849 }
2850 EXPORT_SYMBOL(sk_stop_timer);
2851 
2852 void sock_init_data(struct socket *sock, struct sock *sk)
2853 {
2854 	sk_init_common(sk);
2855 	sk->sk_send_head	=	NULL;
2856 
2857 	timer_setup(&sk->sk_timer, NULL, 0);
2858 
2859 	sk->sk_allocation	=	GFP_KERNEL;
2860 	sk->sk_rcvbuf		=	sysctl_rmem_default;
2861 	sk->sk_sndbuf		=	sysctl_wmem_default;
2862 	sk->sk_state		=	TCP_CLOSE;
2863 	sk_set_socket(sk, sock);
2864 
2865 	sock_set_flag(sk, SOCK_ZAPPED);
2866 
2867 	if (sock) {
2868 		sk->sk_type	=	sock->type;
2869 		RCU_INIT_POINTER(sk->sk_wq, &sock->wq);
2870 		sock->sk	=	sk;
2871 		sk->sk_uid	=	SOCK_INODE(sock)->i_uid;
2872 	} else {
2873 		RCU_INIT_POINTER(sk->sk_wq, NULL);
2874 		sk->sk_uid	=	make_kuid(sock_net(sk)->user_ns, 0);
2875 	}
2876 
2877 	rwlock_init(&sk->sk_callback_lock);
2878 	if (sk->sk_kern_sock)
2879 		lockdep_set_class_and_name(
2880 			&sk->sk_callback_lock,
2881 			af_kern_callback_keys + sk->sk_family,
2882 			af_family_kern_clock_key_strings[sk->sk_family]);
2883 	else
2884 		lockdep_set_class_and_name(
2885 			&sk->sk_callback_lock,
2886 			af_callback_keys + sk->sk_family,
2887 			af_family_clock_key_strings[sk->sk_family]);
2888 
2889 	sk->sk_state_change	=	sock_def_wakeup;
2890 	sk->sk_data_ready	=	sock_def_readable;
2891 	sk->sk_write_space	=	sock_def_write_space;
2892 	sk->sk_error_report	=	sock_def_error_report;
2893 	sk->sk_destruct		=	sock_def_destruct;
2894 
2895 	sk->sk_frag.page	=	NULL;
2896 	sk->sk_frag.offset	=	0;
2897 	sk->sk_peek_off		=	-1;
2898 
2899 	sk->sk_peer_pid 	=	NULL;
2900 	sk->sk_peer_cred	=	NULL;
2901 	sk->sk_write_pending	=	0;
2902 	sk->sk_rcvlowat		=	1;
2903 	sk->sk_rcvtimeo		=	MAX_SCHEDULE_TIMEOUT;
2904 	sk->sk_sndtimeo		=	MAX_SCHEDULE_TIMEOUT;
2905 
2906 	sk->sk_stamp = SK_DEFAULT_STAMP;
2907 #if BITS_PER_LONG==32
2908 	seqlock_init(&sk->sk_stamp_seq);
2909 #endif
2910 	atomic_set(&sk->sk_zckey, 0);
2911 
2912 #ifdef CONFIG_NET_RX_BUSY_POLL
2913 	sk->sk_napi_id		=	0;
2914 	sk->sk_ll_usec		=	sysctl_net_busy_read;
2915 #endif
2916 
2917 	sk->sk_max_pacing_rate = ~0UL;
2918 	sk->sk_pacing_rate = ~0UL;
2919 	sk->sk_pacing_shift = 10;
2920 	sk->sk_incoming_cpu = -1;
2921 
2922 	sk_rx_queue_clear(sk);
2923 	/*
2924 	 * Before updating sk_refcnt, we must commit prior changes to memory
2925 	 * (Documentation/RCU/rculist_nulls.txt for details)
2926 	 */
2927 	smp_wmb();
2928 	refcount_set(&sk->sk_refcnt, 1);
2929 	atomic_set(&sk->sk_drops, 0);
2930 }
2931 EXPORT_SYMBOL(sock_init_data);
2932 
2933 void lock_sock_nested(struct sock *sk, int subclass)
2934 {
2935 	might_sleep();
2936 	spin_lock_bh(&sk->sk_lock.slock);
2937 	if (sk->sk_lock.owned)
2938 		__lock_sock(sk);
2939 	sk->sk_lock.owned = 1;
2940 	spin_unlock(&sk->sk_lock.slock);
2941 	/*
2942 	 * The sk_lock has mutex_lock() semantics here:
2943 	 */
2944 	mutex_acquire(&sk->sk_lock.dep_map, subclass, 0, _RET_IP_);
2945 	local_bh_enable();
2946 }
2947 EXPORT_SYMBOL(lock_sock_nested);
2948 
2949 void release_sock(struct sock *sk)
2950 {
2951 	spin_lock_bh(&sk->sk_lock.slock);
2952 	if (sk->sk_backlog.tail)
2953 		__release_sock(sk);
2954 
2955 	/* Warning : release_cb() might need to release sk ownership,
2956 	 * ie call sock_release_ownership(sk) before us.
2957 	 */
2958 	if (sk->sk_prot->release_cb)
2959 		sk->sk_prot->release_cb(sk);
2960 
2961 	sock_release_ownership(sk);
2962 	if (waitqueue_active(&sk->sk_lock.wq))
2963 		wake_up(&sk->sk_lock.wq);
2964 	spin_unlock_bh(&sk->sk_lock.slock);
2965 }
2966 EXPORT_SYMBOL(release_sock);
2967 
2968 /**
2969  * lock_sock_fast - fast version of lock_sock
2970  * @sk: socket
2971  *
2972  * This version should be used for very small section, where process wont block
2973  * return false if fast path is taken:
2974  *
2975  *   sk_lock.slock locked, owned = 0, BH disabled
2976  *
2977  * return true if slow path is taken:
2978  *
2979  *   sk_lock.slock unlocked, owned = 1, BH enabled
2980  */
2981 bool lock_sock_fast(struct sock *sk)
2982 {
2983 	might_sleep();
2984 	spin_lock_bh(&sk->sk_lock.slock);
2985 
2986 	if (!sk->sk_lock.owned)
2987 		/*
2988 		 * Note : We must disable BH
2989 		 */
2990 		return false;
2991 
2992 	__lock_sock(sk);
2993 	sk->sk_lock.owned = 1;
2994 	spin_unlock(&sk->sk_lock.slock);
2995 	/*
2996 	 * The sk_lock has mutex_lock() semantics here:
2997 	 */
2998 	mutex_acquire(&sk->sk_lock.dep_map, 0, 0, _RET_IP_);
2999 	local_bh_enable();
3000 	return true;
3001 }
3002 EXPORT_SYMBOL(lock_sock_fast);
3003 
3004 int sock_gettstamp(struct socket *sock, void __user *userstamp,
3005 		   bool timeval, bool time32)
3006 {
3007 	struct sock *sk = sock->sk;
3008 	struct timespec64 ts;
3009 
3010 	sock_enable_timestamp(sk, SOCK_TIMESTAMP);
3011 	ts = ktime_to_timespec64(sock_read_timestamp(sk));
3012 	if (ts.tv_sec == -1)
3013 		return -ENOENT;
3014 	if (ts.tv_sec == 0) {
3015 		ktime_t kt = ktime_get_real();
3016 		sock_write_timestamp(sk, kt);
3017 		ts = ktime_to_timespec64(kt);
3018 	}
3019 
3020 	if (timeval)
3021 		ts.tv_nsec /= 1000;
3022 
3023 #ifdef CONFIG_COMPAT_32BIT_TIME
3024 	if (time32)
3025 		return put_old_timespec32(&ts, userstamp);
3026 #endif
3027 #ifdef CONFIG_SPARC64
3028 	/* beware of padding in sparc64 timeval */
3029 	if (timeval && !in_compat_syscall()) {
3030 		struct __kernel_old_timeval __user tv = {
3031 			.tv_sec = ts.tv_sec,
3032 			.tv_usec = ts.tv_nsec,
3033 		};
3034 		if (copy_to_user(userstamp, &tv, sizeof(tv)))
3035 			return -EFAULT;
3036 		return 0;
3037 	}
3038 #endif
3039 	return put_timespec64(&ts, userstamp);
3040 }
3041 EXPORT_SYMBOL(sock_gettstamp);
3042 
3043 void sock_enable_timestamp(struct sock *sk, enum sock_flags flag)
3044 {
3045 	if (!sock_flag(sk, flag)) {
3046 		unsigned long previous_flags = sk->sk_flags;
3047 
3048 		sock_set_flag(sk, flag);
3049 		/*
3050 		 * we just set one of the two flags which require net
3051 		 * time stamping, but time stamping might have been on
3052 		 * already because of the other one
3053 		 */
3054 		if (sock_needs_netstamp(sk) &&
3055 		    !(previous_flags & SK_FLAGS_TIMESTAMP))
3056 			net_enable_timestamp();
3057 	}
3058 }
3059 
3060 int sock_recv_errqueue(struct sock *sk, struct msghdr *msg, int len,
3061 		       int level, int type)
3062 {
3063 	struct sock_exterr_skb *serr;
3064 	struct sk_buff *skb;
3065 	int copied, err;
3066 
3067 	err = -EAGAIN;
3068 	skb = sock_dequeue_err_skb(sk);
3069 	if (skb == NULL)
3070 		goto out;
3071 
3072 	copied = skb->len;
3073 	if (copied > len) {
3074 		msg->msg_flags |= MSG_TRUNC;
3075 		copied = len;
3076 	}
3077 	err = skb_copy_datagram_msg(skb, 0, msg, copied);
3078 	if (err)
3079 		goto out_free_skb;
3080 
3081 	sock_recv_timestamp(msg, sk, skb);
3082 
3083 	serr = SKB_EXT_ERR(skb);
3084 	put_cmsg(msg, level, type, sizeof(serr->ee), &serr->ee);
3085 
3086 	msg->msg_flags |= MSG_ERRQUEUE;
3087 	err = copied;
3088 
3089 out_free_skb:
3090 	kfree_skb(skb);
3091 out:
3092 	return err;
3093 }
3094 EXPORT_SYMBOL(sock_recv_errqueue);
3095 
3096 /*
3097  *	Get a socket option on an socket.
3098  *
3099  *	FIX: POSIX 1003.1g is very ambiguous here. It states that
3100  *	asynchronous errors should be reported by getsockopt. We assume
3101  *	this means if you specify SO_ERROR (otherwise whats the point of it).
3102  */
3103 int sock_common_getsockopt(struct socket *sock, int level, int optname,
3104 			   char __user *optval, int __user *optlen)
3105 {
3106 	struct sock *sk = sock->sk;
3107 
3108 	return sk->sk_prot->getsockopt(sk, level, optname, optval, optlen);
3109 }
3110 EXPORT_SYMBOL(sock_common_getsockopt);
3111 
3112 #ifdef CONFIG_COMPAT
3113 int compat_sock_common_getsockopt(struct socket *sock, int level, int optname,
3114 				  char __user *optval, int __user *optlen)
3115 {
3116 	struct sock *sk = sock->sk;
3117 
3118 	if (sk->sk_prot->compat_getsockopt != NULL)
3119 		return sk->sk_prot->compat_getsockopt(sk, level, optname,
3120 						      optval, optlen);
3121 	return sk->sk_prot->getsockopt(sk, level, optname, optval, optlen);
3122 }
3123 EXPORT_SYMBOL(compat_sock_common_getsockopt);
3124 #endif
3125 
3126 int sock_common_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
3127 			int flags)
3128 {
3129 	struct sock *sk = sock->sk;
3130 	int addr_len = 0;
3131 	int err;
3132 
3133 	err = sk->sk_prot->recvmsg(sk, msg, size, flags & MSG_DONTWAIT,
3134 				   flags & ~MSG_DONTWAIT, &addr_len);
3135 	if (err >= 0)
3136 		msg->msg_namelen = addr_len;
3137 	return err;
3138 }
3139 EXPORT_SYMBOL(sock_common_recvmsg);
3140 
3141 /*
3142  *	Set socket options on an inet socket.
3143  */
3144 int sock_common_setsockopt(struct socket *sock, int level, int optname,
3145 			   char __user *optval, unsigned int optlen)
3146 {
3147 	struct sock *sk = sock->sk;
3148 
3149 	return sk->sk_prot->setsockopt(sk, level, optname, optval, optlen);
3150 }
3151 EXPORT_SYMBOL(sock_common_setsockopt);
3152 
3153 #ifdef CONFIG_COMPAT
3154 int compat_sock_common_setsockopt(struct socket *sock, int level, int optname,
3155 				  char __user *optval, unsigned int optlen)
3156 {
3157 	struct sock *sk = sock->sk;
3158 
3159 	if (sk->sk_prot->compat_setsockopt != NULL)
3160 		return sk->sk_prot->compat_setsockopt(sk, level, optname,
3161 						      optval, optlen);
3162 	return sk->sk_prot->setsockopt(sk, level, optname, optval, optlen);
3163 }
3164 EXPORT_SYMBOL(compat_sock_common_setsockopt);
3165 #endif
3166 
3167 void sk_common_release(struct sock *sk)
3168 {
3169 	if (sk->sk_prot->destroy)
3170 		sk->sk_prot->destroy(sk);
3171 
3172 	/*
3173 	 * Observation: when sock_common_release is called, processes have
3174 	 * no access to socket. But net still has.
3175 	 * Step one, detach it from networking:
3176 	 *
3177 	 * A. Remove from hash tables.
3178 	 */
3179 
3180 	sk->sk_prot->unhash(sk);
3181 
3182 	/*
3183 	 * In this point socket cannot receive new packets, but it is possible
3184 	 * that some packets are in flight because some CPU runs receiver and
3185 	 * did hash table lookup before we unhashed socket. They will achieve
3186 	 * receive queue and will be purged by socket destructor.
3187 	 *
3188 	 * Also we still have packets pending on receive queue and probably,
3189 	 * our own packets waiting in device queues. sock_destroy will drain
3190 	 * receive queue, but transmitted packets will delay socket destruction
3191 	 * until the last reference will be released.
3192 	 */
3193 
3194 	sock_orphan(sk);
3195 
3196 	xfrm_sk_free_policy(sk);
3197 
3198 	sk_refcnt_debug_release(sk);
3199 
3200 	sock_put(sk);
3201 }
3202 EXPORT_SYMBOL(sk_common_release);
3203 
3204 void sk_get_meminfo(const struct sock *sk, u32 *mem)
3205 {
3206 	memset(mem, 0, sizeof(*mem) * SK_MEMINFO_VARS);
3207 
3208 	mem[SK_MEMINFO_RMEM_ALLOC] = sk_rmem_alloc_get(sk);
3209 	mem[SK_MEMINFO_RCVBUF] = READ_ONCE(sk->sk_rcvbuf);
3210 	mem[SK_MEMINFO_WMEM_ALLOC] = sk_wmem_alloc_get(sk);
3211 	mem[SK_MEMINFO_SNDBUF] = READ_ONCE(sk->sk_sndbuf);
3212 	mem[SK_MEMINFO_FWD_ALLOC] = sk->sk_forward_alloc;
3213 	mem[SK_MEMINFO_WMEM_QUEUED] = READ_ONCE(sk->sk_wmem_queued);
3214 	mem[SK_MEMINFO_OPTMEM] = atomic_read(&sk->sk_omem_alloc);
3215 	mem[SK_MEMINFO_BACKLOG] = READ_ONCE(sk->sk_backlog.len);
3216 	mem[SK_MEMINFO_DROPS] = atomic_read(&sk->sk_drops);
3217 }
3218 
3219 #ifdef CONFIG_PROC_FS
3220 #define PROTO_INUSE_NR	64	/* should be enough for the first time */
3221 struct prot_inuse {
3222 	int val[PROTO_INUSE_NR];
3223 };
3224 
3225 static DECLARE_BITMAP(proto_inuse_idx, PROTO_INUSE_NR);
3226 
3227 void sock_prot_inuse_add(struct net *net, struct proto *prot, int val)
3228 {
3229 	__this_cpu_add(net->core.prot_inuse->val[prot->inuse_idx], val);
3230 }
3231 EXPORT_SYMBOL_GPL(sock_prot_inuse_add);
3232 
3233 int sock_prot_inuse_get(struct net *net, struct proto *prot)
3234 {
3235 	int cpu, idx = prot->inuse_idx;
3236 	int res = 0;
3237 
3238 	for_each_possible_cpu(cpu)
3239 		res += per_cpu_ptr(net->core.prot_inuse, cpu)->val[idx];
3240 
3241 	return res >= 0 ? res : 0;
3242 }
3243 EXPORT_SYMBOL_GPL(sock_prot_inuse_get);
3244 
3245 static void sock_inuse_add(struct net *net, int val)
3246 {
3247 	this_cpu_add(*net->core.sock_inuse, val);
3248 }
3249 
3250 int sock_inuse_get(struct net *net)
3251 {
3252 	int cpu, res = 0;
3253 
3254 	for_each_possible_cpu(cpu)
3255 		res += *per_cpu_ptr(net->core.sock_inuse, cpu);
3256 
3257 	return res;
3258 }
3259 
3260 EXPORT_SYMBOL_GPL(sock_inuse_get);
3261 
3262 static int __net_init sock_inuse_init_net(struct net *net)
3263 {
3264 	net->core.prot_inuse = alloc_percpu(struct prot_inuse);
3265 	if (net->core.prot_inuse == NULL)
3266 		return -ENOMEM;
3267 
3268 	net->core.sock_inuse = alloc_percpu(int);
3269 	if (net->core.sock_inuse == NULL)
3270 		goto out;
3271 
3272 	return 0;
3273 
3274 out:
3275 	free_percpu(net->core.prot_inuse);
3276 	return -ENOMEM;
3277 }
3278 
3279 static void __net_exit sock_inuse_exit_net(struct net *net)
3280 {
3281 	free_percpu(net->core.prot_inuse);
3282 	free_percpu(net->core.sock_inuse);
3283 }
3284 
3285 static struct pernet_operations net_inuse_ops = {
3286 	.init = sock_inuse_init_net,
3287 	.exit = sock_inuse_exit_net,
3288 };
3289 
3290 static __init int net_inuse_init(void)
3291 {
3292 	if (register_pernet_subsys(&net_inuse_ops))
3293 		panic("Cannot initialize net inuse counters");
3294 
3295 	return 0;
3296 }
3297 
3298 core_initcall(net_inuse_init);
3299 
3300 static int assign_proto_idx(struct proto *prot)
3301 {
3302 	prot->inuse_idx = find_first_zero_bit(proto_inuse_idx, PROTO_INUSE_NR);
3303 
3304 	if (unlikely(prot->inuse_idx == PROTO_INUSE_NR - 1)) {
3305 		pr_err("PROTO_INUSE_NR exhausted\n");
3306 		return -ENOSPC;
3307 	}
3308 
3309 	set_bit(prot->inuse_idx, proto_inuse_idx);
3310 	return 0;
3311 }
3312 
3313 static void release_proto_idx(struct proto *prot)
3314 {
3315 	if (prot->inuse_idx != PROTO_INUSE_NR - 1)
3316 		clear_bit(prot->inuse_idx, proto_inuse_idx);
3317 }
3318 #else
3319 static inline int assign_proto_idx(struct proto *prot)
3320 {
3321 	return 0;
3322 }
3323 
3324 static inline void release_proto_idx(struct proto *prot)
3325 {
3326 }
3327 
3328 static void sock_inuse_add(struct net *net, int val)
3329 {
3330 }
3331 #endif
3332 
3333 static void req_prot_cleanup(struct request_sock_ops *rsk_prot)
3334 {
3335 	if (!rsk_prot)
3336 		return;
3337 	kfree(rsk_prot->slab_name);
3338 	rsk_prot->slab_name = NULL;
3339 	kmem_cache_destroy(rsk_prot->slab);
3340 	rsk_prot->slab = NULL;
3341 }
3342 
3343 static int req_prot_init(const struct proto *prot)
3344 {
3345 	struct request_sock_ops *rsk_prot = prot->rsk_prot;
3346 
3347 	if (!rsk_prot)
3348 		return 0;
3349 
3350 	rsk_prot->slab_name = kasprintf(GFP_KERNEL, "request_sock_%s",
3351 					prot->name);
3352 	if (!rsk_prot->slab_name)
3353 		return -ENOMEM;
3354 
3355 	rsk_prot->slab = kmem_cache_create(rsk_prot->slab_name,
3356 					   rsk_prot->obj_size, 0,
3357 					   SLAB_ACCOUNT | prot->slab_flags,
3358 					   NULL);
3359 
3360 	if (!rsk_prot->slab) {
3361 		pr_crit("%s: Can't create request sock SLAB cache!\n",
3362 			prot->name);
3363 		return -ENOMEM;
3364 	}
3365 	return 0;
3366 }
3367 
3368 int proto_register(struct proto *prot, int alloc_slab)
3369 {
3370 	int ret = -ENOBUFS;
3371 
3372 	if (alloc_slab) {
3373 		prot->slab = kmem_cache_create_usercopy(prot->name,
3374 					prot->obj_size, 0,
3375 					SLAB_HWCACHE_ALIGN | SLAB_ACCOUNT |
3376 					prot->slab_flags,
3377 					prot->useroffset, prot->usersize,
3378 					NULL);
3379 
3380 		if (prot->slab == NULL) {
3381 			pr_crit("%s: Can't create sock SLAB cache!\n",
3382 				prot->name);
3383 			goto out;
3384 		}
3385 
3386 		if (req_prot_init(prot))
3387 			goto out_free_request_sock_slab;
3388 
3389 		if (prot->twsk_prot != NULL) {
3390 			prot->twsk_prot->twsk_slab_name = kasprintf(GFP_KERNEL, "tw_sock_%s", prot->name);
3391 
3392 			if (prot->twsk_prot->twsk_slab_name == NULL)
3393 				goto out_free_request_sock_slab;
3394 
3395 			prot->twsk_prot->twsk_slab =
3396 				kmem_cache_create(prot->twsk_prot->twsk_slab_name,
3397 						  prot->twsk_prot->twsk_obj_size,
3398 						  0,
3399 						  SLAB_ACCOUNT |
3400 						  prot->slab_flags,
3401 						  NULL);
3402 			if (prot->twsk_prot->twsk_slab == NULL)
3403 				goto out_free_timewait_sock_slab_name;
3404 		}
3405 	}
3406 
3407 	mutex_lock(&proto_list_mutex);
3408 	ret = assign_proto_idx(prot);
3409 	if (ret) {
3410 		mutex_unlock(&proto_list_mutex);
3411 		goto out_free_timewait_sock_slab_name;
3412 	}
3413 	list_add(&prot->node, &proto_list);
3414 	mutex_unlock(&proto_list_mutex);
3415 	return ret;
3416 
3417 out_free_timewait_sock_slab_name:
3418 	if (alloc_slab && prot->twsk_prot)
3419 		kfree(prot->twsk_prot->twsk_slab_name);
3420 out_free_request_sock_slab:
3421 	if (alloc_slab) {
3422 		req_prot_cleanup(prot->rsk_prot);
3423 
3424 		kmem_cache_destroy(prot->slab);
3425 		prot->slab = NULL;
3426 	}
3427 out:
3428 	return ret;
3429 }
3430 EXPORT_SYMBOL(proto_register);
3431 
3432 void proto_unregister(struct proto *prot)
3433 {
3434 	mutex_lock(&proto_list_mutex);
3435 	release_proto_idx(prot);
3436 	list_del(&prot->node);
3437 	mutex_unlock(&proto_list_mutex);
3438 
3439 	kmem_cache_destroy(prot->slab);
3440 	prot->slab = NULL;
3441 
3442 	req_prot_cleanup(prot->rsk_prot);
3443 
3444 	if (prot->twsk_prot != NULL && prot->twsk_prot->twsk_slab != NULL) {
3445 		kmem_cache_destroy(prot->twsk_prot->twsk_slab);
3446 		kfree(prot->twsk_prot->twsk_slab_name);
3447 		prot->twsk_prot->twsk_slab = NULL;
3448 	}
3449 }
3450 EXPORT_SYMBOL(proto_unregister);
3451 
3452 int sock_load_diag_module(int family, int protocol)
3453 {
3454 	if (!protocol) {
3455 		if (!sock_is_registered(family))
3456 			return -ENOENT;
3457 
3458 		return request_module("net-pf-%d-proto-%d-type-%d", PF_NETLINK,
3459 				      NETLINK_SOCK_DIAG, family);
3460 	}
3461 
3462 #ifdef CONFIG_INET
3463 	if (family == AF_INET &&
3464 	    protocol != IPPROTO_RAW &&
3465 	    !rcu_access_pointer(inet_protos[protocol]))
3466 		return -ENOENT;
3467 #endif
3468 
3469 	return request_module("net-pf-%d-proto-%d-type-%d-%d", PF_NETLINK,
3470 			      NETLINK_SOCK_DIAG, family, protocol);
3471 }
3472 EXPORT_SYMBOL(sock_load_diag_module);
3473 
3474 #ifdef CONFIG_PROC_FS
3475 static void *proto_seq_start(struct seq_file *seq, loff_t *pos)
3476 	__acquires(proto_list_mutex)
3477 {
3478 	mutex_lock(&proto_list_mutex);
3479 	return seq_list_start_head(&proto_list, *pos);
3480 }
3481 
3482 static void *proto_seq_next(struct seq_file *seq, void *v, loff_t *pos)
3483 {
3484 	return seq_list_next(v, &proto_list, pos);
3485 }
3486 
3487 static void proto_seq_stop(struct seq_file *seq, void *v)
3488 	__releases(proto_list_mutex)
3489 {
3490 	mutex_unlock(&proto_list_mutex);
3491 }
3492 
3493 static char proto_method_implemented(const void *method)
3494 {
3495 	return method == NULL ? 'n' : 'y';
3496 }
3497 static long sock_prot_memory_allocated(struct proto *proto)
3498 {
3499 	return proto->memory_allocated != NULL ? proto_memory_allocated(proto) : -1L;
3500 }
3501 
3502 static const char *sock_prot_memory_pressure(struct proto *proto)
3503 {
3504 	return proto->memory_pressure != NULL ?
3505 	proto_memory_pressure(proto) ? "yes" : "no" : "NI";
3506 }
3507 
3508 static void proto_seq_printf(struct seq_file *seq, struct proto *proto)
3509 {
3510 
3511 	seq_printf(seq, "%-9s %4u %6d  %6ld   %-3s %6u   %-3s  %-10s "
3512 			"%2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c\n",
3513 		   proto->name,
3514 		   proto->obj_size,
3515 		   sock_prot_inuse_get(seq_file_net(seq), proto),
3516 		   sock_prot_memory_allocated(proto),
3517 		   sock_prot_memory_pressure(proto),
3518 		   proto->max_header,
3519 		   proto->slab == NULL ? "no" : "yes",
3520 		   module_name(proto->owner),
3521 		   proto_method_implemented(proto->close),
3522 		   proto_method_implemented(proto->connect),
3523 		   proto_method_implemented(proto->disconnect),
3524 		   proto_method_implemented(proto->accept),
3525 		   proto_method_implemented(proto->ioctl),
3526 		   proto_method_implemented(proto->init),
3527 		   proto_method_implemented(proto->destroy),
3528 		   proto_method_implemented(proto->shutdown),
3529 		   proto_method_implemented(proto->setsockopt),
3530 		   proto_method_implemented(proto->getsockopt),
3531 		   proto_method_implemented(proto->sendmsg),
3532 		   proto_method_implemented(proto->recvmsg),
3533 		   proto_method_implemented(proto->sendpage),
3534 		   proto_method_implemented(proto->bind),
3535 		   proto_method_implemented(proto->backlog_rcv),
3536 		   proto_method_implemented(proto->hash),
3537 		   proto_method_implemented(proto->unhash),
3538 		   proto_method_implemented(proto->get_port),
3539 		   proto_method_implemented(proto->enter_memory_pressure));
3540 }
3541 
3542 static int proto_seq_show(struct seq_file *seq, void *v)
3543 {
3544 	if (v == &proto_list)
3545 		seq_printf(seq, "%-9s %-4s %-8s %-6s %-5s %-7s %-4s %-10s %s",
3546 			   "protocol",
3547 			   "size",
3548 			   "sockets",
3549 			   "memory",
3550 			   "press",
3551 			   "maxhdr",
3552 			   "slab",
3553 			   "module",
3554 			   "cl co di ac io in de sh ss gs se re sp bi br ha uh gp em\n");
3555 	else
3556 		proto_seq_printf(seq, list_entry(v, struct proto, node));
3557 	return 0;
3558 }
3559 
3560 static const struct seq_operations proto_seq_ops = {
3561 	.start  = proto_seq_start,
3562 	.next   = proto_seq_next,
3563 	.stop   = proto_seq_stop,
3564 	.show   = proto_seq_show,
3565 };
3566 
3567 static __net_init int proto_init_net(struct net *net)
3568 {
3569 	if (!proc_create_net("protocols", 0444, net->proc_net, &proto_seq_ops,
3570 			sizeof(struct seq_net_private)))
3571 		return -ENOMEM;
3572 
3573 	return 0;
3574 }
3575 
3576 static __net_exit void proto_exit_net(struct net *net)
3577 {
3578 	remove_proc_entry("protocols", net->proc_net);
3579 }
3580 
3581 
3582 static __net_initdata struct pernet_operations proto_net_ops = {
3583 	.init = proto_init_net,
3584 	.exit = proto_exit_net,
3585 };
3586 
3587 static int __init proto_init(void)
3588 {
3589 	return register_pernet_subsys(&proto_net_ops);
3590 }
3591 
3592 subsys_initcall(proto_init);
3593 
3594 #endif /* PROC_FS */
3595 
3596 #ifdef CONFIG_NET_RX_BUSY_POLL
3597 bool sk_busy_loop_end(void *p, unsigned long start_time)
3598 {
3599 	struct sock *sk = p;
3600 
3601 	return !skb_queue_empty_lockless(&sk->sk_receive_queue) ||
3602 	       sk_busy_loop_timeout(sk, start_time);
3603 }
3604 EXPORT_SYMBOL(sk_busy_loop_end);
3605 #endif /* CONFIG_NET_RX_BUSY_POLL */
3606