xref: /linux/net/core/sock.c (revision 65c93628599dff4cd7cfb70130d1f6a2203731ea)
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 	const struct proto *prot = READ_ONCE(osk->sk_prot);
1576 #ifdef CONFIG_SECURITY_NETWORK
1577 	void *sptr = nsk->sk_security;
1578 #endif
1579 	memcpy(nsk, osk, offsetof(struct sock, sk_dontcopy_begin));
1580 
1581 	memcpy(&nsk->sk_dontcopy_end, &osk->sk_dontcopy_end,
1582 	       prot->obj_size - offsetof(struct sock, sk_dontcopy_end));
1583 
1584 #ifdef CONFIG_SECURITY_NETWORK
1585 	nsk->sk_security = sptr;
1586 	security_sk_clone(osk, nsk);
1587 #endif
1588 }
1589 
1590 static struct sock *sk_prot_alloc(struct proto *prot, gfp_t priority,
1591 		int family)
1592 {
1593 	struct sock *sk;
1594 	struct kmem_cache *slab;
1595 
1596 	slab = prot->slab;
1597 	if (slab != NULL) {
1598 		sk = kmem_cache_alloc(slab, priority & ~__GFP_ZERO);
1599 		if (!sk)
1600 			return sk;
1601 		if (want_init_on_alloc(priority))
1602 			sk_prot_clear_nulls(sk, prot->obj_size);
1603 	} else
1604 		sk = kmalloc(prot->obj_size, priority);
1605 
1606 	if (sk != NULL) {
1607 		if (security_sk_alloc(sk, family, priority))
1608 			goto out_free;
1609 
1610 		if (!try_module_get(prot->owner))
1611 			goto out_free_sec;
1612 		sk_tx_queue_clear(sk);
1613 	}
1614 
1615 	return sk;
1616 
1617 out_free_sec:
1618 	security_sk_free(sk);
1619 out_free:
1620 	if (slab != NULL)
1621 		kmem_cache_free(slab, sk);
1622 	else
1623 		kfree(sk);
1624 	return NULL;
1625 }
1626 
1627 static void sk_prot_free(struct proto *prot, struct sock *sk)
1628 {
1629 	struct kmem_cache *slab;
1630 	struct module *owner;
1631 
1632 	owner = prot->owner;
1633 	slab = prot->slab;
1634 
1635 	cgroup_sk_free(&sk->sk_cgrp_data);
1636 	mem_cgroup_sk_free(sk);
1637 	security_sk_free(sk);
1638 	if (slab != NULL)
1639 		kmem_cache_free(slab, sk);
1640 	else
1641 		kfree(sk);
1642 	module_put(owner);
1643 }
1644 
1645 /**
1646  *	sk_alloc - All socket objects are allocated here
1647  *	@net: the applicable net namespace
1648  *	@family: protocol family
1649  *	@priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
1650  *	@prot: struct proto associated with this new sock instance
1651  *	@kern: is this to be a kernel socket?
1652  */
1653 struct sock *sk_alloc(struct net *net, int family, gfp_t priority,
1654 		      struct proto *prot, int kern)
1655 {
1656 	struct sock *sk;
1657 
1658 	sk = sk_prot_alloc(prot, priority | __GFP_ZERO, family);
1659 	if (sk) {
1660 		sk->sk_family = family;
1661 		/*
1662 		 * See comment in struct sock definition to understand
1663 		 * why we need sk_prot_creator -acme
1664 		 */
1665 		sk->sk_prot = sk->sk_prot_creator = prot;
1666 		sk->sk_kern_sock = kern;
1667 		sock_lock_init(sk);
1668 		sk->sk_net_refcnt = kern ? 0 : 1;
1669 		if (likely(sk->sk_net_refcnt)) {
1670 			get_net(net);
1671 			sock_inuse_add(net, 1);
1672 		}
1673 
1674 		sock_net_set(sk, net);
1675 		refcount_set(&sk->sk_wmem_alloc, 1);
1676 
1677 		mem_cgroup_sk_alloc(sk);
1678 		cgroup_sk_alloc(&sk->sk_cgrp_data);
1679 		sock_update_classid(&sk->sk_cgrp_data);
1680 		sock_update_netprioidx(&sk->sk_cgrp_data);
1681 	}
1682 
1683 	return sk;
1684 }
1685 EXPORT_SYMBOL(sk_alloc);
1686 
1687 /* Sockets having SOCK_RCU_FREE will call this function after one RCU
1688  * grace period. This is the case for UDP sockets and TCP listeners.
1689  */
1690 static void __sk_destruct(struct rcu_head *head)
1691 {
1692 	struct sock *sk = container_of(head, struct sock, sk_rcu);
1693 	struct sk_filter *filter;
1694 
1695 	if (sk->sk_destruct)
1696 		sk->sk_destruct(sk);
1697 
1698 	filter = rcu_dereference_check(sk->sk_filter,
1699 				       refcount_read(&sk->sk_wmem_alloc) == 0);
1700 	if (filter) {
1701 		sk_filter_uncharge(sk, filter);
1702 		RCU_INIT_POINTER(sk->sk_filter, NULL);
1703 	}
1704 
1705 	sock_disable_timestamp(sk, SK_FLAGS_TIMESTAMP);
1706 
1707 #ifdef CONFIG_BPF_SYSCALL
1708 	bpf_sk_storage_free(sk);
1709 #endif
1710 
1711 	if (atomic_read(&sk->sk_omem_alloc))
1712 		pr_debug("%s: optmem leakage (%d bytes) detected\n",
1713 			 __func__, atomic_read(&sk->sk_omem_alloc));
1714 
1715 	if (sk->sk_frag.page) {
1716 		put_page(sk->sk_frag.page);
1717 		sk->sk_frag.page = NULL;
1718 	}
1719 
1720 	if (sk->sk_peer_cred)
1721 		put_cred(sk->sk_peer_cred);
1722 	put_pid(sk->sk_peer_pid);
1723 	if (likely(sk->sk_net_refcnt))
1724 		put_net(sock_net(sk));
1725 	sk_prot_free(sk->sk_prot_creator, sk);
1726 }
1727 
1728 void sk_destruct(struct sock *sk)
1729 {
1730 	bool use_call_rcu = sock_flag(sk, SOCK_RCU_FREE);
1731 
1732 	if (rcu_access_pointer(sk->sk_reuseport_cb)) {
1733 		reuseport_detach_sock(sk);
1734 		use_call_rcu = true;
1735 	}
1736 
1737 	if (use_call_rcu)
1738 		call_rcu(&sk->sk_rcu, __sk_destruct);
1739 	else
1740 		__sk_destruct(&sk->sk_rcu);
1741 }
1742 
1743 static void __sk_free(struct sock *sk)
1744 {
1745 	if (likely(sk->sk_net_refcnt))
1746 		sock_inuse_add(sock_net(sk), -1);
1747 
1748 	if (unlikely(sk->sk_net_refcnt && sock_diag_has_destroy_listeners(sk)))
1749 		sock_diag_broadcast_destroy(sk);
1750 	else
1751 		sk_destruct(sk);
1752 }
1753 
1754 void sk_free(struct sock *sk)
1755 {
1756 	/*
1757 	 * We subtract one from sk_wmem_alloc and can know if
1758 	 * some packets are still in some tx queue.
1759 	 * If not null, sock_wfree() will call __sk_free(sk) later
1760 	 */
1761 	if (refcount_dec_and_test(&sk->sk_wmem_alloc))
1762 		__sk_free(sk);
1763 }
1764 EXPORT_SYMBOL(sk_free);
1765 
1766 static void sk_init_common(struct sock *sk)
1767 {
1768 	skb_queue_head_init(&sk->sk_receive_queue);
1769 	skb_queue_head_init(&sk->sk_write_queue);
1770 	skb_queue_head_init(&sk->sk_error_queue);
1771 
1772 	rwlock_init(&sk->sk_callback_lock);
1773 	lockdep_set_class_and_name(&sk->sk_receive_queue.lock,
1774 			af_rlock_keys + sk->sk_family,
1775 			af_family_rlock_key_strings[sk->sk_family]);
1776 	lockdep_set_class_and_name(&sk->sk_write_queue.lock,
1777 			af_wlock_keys + sk->sk_family,
1778 			af_family_wlock_key_strings[sk->sk_family]);
1779 	lockdep_set_class_and_name(&sk->sk_error_queue.lock,
1780 			af_elock_keys + sk->sk_family,
1781 			af_family_elock_key_strings[sk->sk_family]);
1782 	lockdep_set_class_and_name(&sk->sk_callback_lock,
1783 			af_callback_keys + sk->sk_family,
1784 			af_family_clock_key_strings[sk->sk_family]);
1785 }
1786 
1787 /**
1788  *	sk_clone_lock - clone a socket, and lock its clone
1789  *	@sk: the socket to clone
1790  *	@priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
1791  *
1792  *	Caller must unlock socket even in error path (bh_unlock_sock(newsk))
1793  */
1794 struct sock *sk_clone_lock(const struct sock *sk, const gfp_t priority)
1795 {
1796 	struct proto *prot = READ_ONCE(sk->sk_prot);
1797 	struct sock *newsk;
1798 	bool is_charged = true;
1799 
1800 	newsk = sk_prot_alloc(prot, priority, sk->sk_family);
1801 	if (newsk != NULL) {
1802 		struct sk_filter *filter;
1803 
1804 		sock_copy(newsk, sk);
1805 
1806 		newsk->sk_prot_creator = prot;
1807 
1808 		/* SANITY */
1809 		if (likely(newsk->sk_net_refcnt))
1810 			get_net(sock_net(newsk));
1811 		sk_node_init(&newsk->sk_node);
1812 		sock_lock_init(newsk);
1813 		bh_lock_sock(newsk);
1814 		newsk->sk_backlog.head	= newsk->sk_backlog.tail = NULL;
1815 		newsk->sk_backlog.len = 0;
1816 
1817 		atomic_set(&newsk->sk_rmem_alloc, 0);
1818 		/*
1819 		 * sk_wmem_alloc set to one (see sk_free() and sock_wfree())
1820 		 */
1821 		refcount_set(&newsk->sk_wmem_alloc, 1);
1822 		atomic_set(&newsk->sk_omem_alloc, 0);
1823 		sk_init_common(newsk);
1824 
1825 		newsk->sk_dst_cache	= NULL;
1826 		newsk->sk_dst_pending_confirm = 0;
1827 		newsk->sk_wmem_queued	= 0;
1828 		newsk->sk_forward_alloc = 0;
1829 		atomic_set(&newsk->sk_drops, 0);
1830 		newsk->sk_send_head	= NULL;
1831 		newsk->sk_userlocks	= sk->sk_userlocks & ~SOCK_BINDPORT_LOCK;
1832 		atomic_set(&newsk->sk_zckey, 0);
1833 
1834 		sock_reset_flag(newsk, SOCK_DONE);
1835 
1836 		/* sk->sk_memcg will be populated at accept() time */
1837 		newsk->sk_memcg = NULL;
1838 
1839 		cgroup_sk_alloc(&newsk->sk_cgrp_data);
1840 
1841 		rcu_read_lock();
1842 		filter = rcu_dereference(sk->sk_filter);
1843 		if (filter != NULL)
1844 			/* though it's an empty new sock, the charging may fail
1845 			 * if sysctl_optmem_max was changed between creation of
1846 			 * original socket and cloning
1847 			 */
1848 			is_charged = sk_filter_charge(newsk, filter);
1849 		RCU_INIT_POINTER(newsk->sk_filter, filter);
1850 		rcu_read_unlock();
1851 
1852 		if (unlikely(!is_charged || xfrm_sk_clone_policy(newsk, sk))) {
1853 			/* We need to make sure that we don't uncharge the new
1854 			 * socket if we couldn't charge it in the first place
1855 			 * as otherwise we uncharge the parent's filter.
1856 			 */
1857 			if (!is_charged)
1858 				RCU_INIT_POINTER(newsk->sk_filter, NULL);
1859 			sk_free_unlock_clone(newsk);
1860 			newsk = NULL;
1861 			goto out;
1862 		}
1863 		RCU_INIT_POINTER(newsk->sk_reuseport_cb, NULL);
1864 
1865 		if (bpf_sk_storage_clone(sk, newsk)) {
1866 			sk_free_unlock_clone(newsk);
1867 			newsk = NULL;
1868 			goto out;
1869 		}
1870 
1871 		/* Clear sk_user_data if parent had the pointer tagged
1872 		 * as not suitable for copying when cloning.
1873 		 */
1874 		if (sk_user_data_is_nocopy(newsk))
1875 			RCU_INIT_POINTER(newsk->sk_user_data, NULL);
1876 
1877 		newsk->sk_err	   = 0;
1878 		newsk->sk_err_soft = 0;
1879 		newsk->sk_priority = 0;
1880 		newsk->sk_incoming_cpu = raw_smp_processor_id();
1881 		if (likely(newsk->sk_net_refcnt))
1882 			sock_inuse_add(sock_net(newsk), 1);
1883 
1884 		/*
1885 		 * Before updating sk_refcnt, we must commit prior changes to memory
1886 		 * (Documentation/RCU/rculist_nulls.txt for details)
1887 		 */
1888 		smp_wmb();
1889 		refcount_set(&newsk->sk_refcnt, 2);
1890 
1891 		/*
1892 		 * Increment the counter in the same struct proto as the master
1893 		 * sock (sk_refcnt_debug_inc uses newsk->sk_prot->socks, that
1894 		 * is the same as sk->sk_prot->socks, as this field was copied
1895 		 * with memcpy).
1896 		 *
1897 		 * This _changes_ the previous behaviour, where
1898 		 * tcp_create_openreq_child always was incrementing the
1899 		 * equivalent to tcp_prot->socks (inet_sock_nr), so this have
1900 		 * to be taken into account in all callers. -acme
1901 		 */
1902 		sk_refcnt_debug_inc(newsk);
1903 		sk_set_socket(newsk, NULL);
1904 		RCU_INIT_POINTER(newsk->sk_wq, NULL);
1905 
1906 		if (newsk->sk_prot->sockets_allocated)
1907 			sk_sockets_allocated_inc(newsk);
1908 
1909 		if (sock_needs_netstamp(sk) &&
1910 		    newsk->sk_flags & SK_FLAGS_TIMESTAMP)
1911 			net_enable_timestamp();
1912 	}
1913 out:
1914 	return newsk;
1915 }
1916 EXPORT_SYMBOL_GPL(sk_clone_lock);
1917 
1918 void sk_free_unlock_clone(struct sock *sk)
1919 {
1920 	/* It is still raw copy of parent, so invalidate
1921 	 * destructor and make plain sk_free() */
1922 	sk->sk_destruct = NULL;
1923 	bh_unlock_sock(sk);
1924 	sk_free(sk);
1925 }
1926 EXPORT_SYMBOL_GPL(sk_free_unlock_clone);
1927 
1928 void sk_setup_caps(struct sock *sk, struct dst_entry *dst)
1929 {
1930 	u32 max_segs = 1;
1931 
1932 	sk_dst_set(sk, dst);
1933 	sk->sk_route_caps = dst->dev->features | sk->sk_route_forced_caps;
1934 	if (sk->sk_route_caps & NETIF_F_GSO)
1935 		sk->sk_route_caps |= NETIF_F_GSO_SOFTWARE;
1936 	sk->sk_route_caps &= ~sk->sk_route_nocaps;
1937 	if (sk_can_gso(sk)) {
1938 		if (dst->header_len && !xfrm_dst_offload_ok(dst)) {
1939 			sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
1940 		} else {
1941 			sk->sk_route_caps |= NETIF_F_SG | NETIF_F_HW_CSUM;
1942 			sk->sk_gso_max_size = dst->dev->gso_max_size;
1943 			max_segs = max_t(u32, dst->dev->gso_max_segs, 1);
1944 		}
1945 	}
1946 	sk->sk_gso_max_segs = max_segs;
1947 }
1948 EXPORT_SYMBOL_GPL(sk_setup_caps);
1949 
1950 /*
1951  *	Simple resource managers for sockets.
1952  */
1953 
1954 
1955 /*
1956  * Write buffer destructor automatically called from kfree_skb.
1957  */
1958 void sock_wfree(struct sk_buff *skb)
1959 {
1960 	struct sock *sk = skb->sk;
1961 	unsigned int len = skb->truesize;
1962 
1963 	if (!sock_flag(sk, SOCK_USE_WRITE_QUEUE)) {
1964 		/*
1965 		 * Keep a reference on sk_wmem_alloc, this will be released
1966 		 * after sk_write_space() call
1967 		 */
1968 		WARN_ON(refcount_sub_and_test(len - 1, &sk->sk_wmem_alloc));
1969 		sk->sk_write_space(sk);
1970 		len = 1;
1971 	}
1972 	/*
1973 	 * if sk_wmem_alloc reaches 0, we must finish what sk_free()
1974 	 * could not do because of in-flight packets
1975 	 */
1976 	if (refcount_sub_and_test(len, &sk->sk_wmem_alloc))
1977 		__sk_free(sk);
1978 }
1979 EXPORT_SYMBOL(sock_wfree);
1980 
1981 /* This variant of sock_wfree() is used by TCP,
1982  * since it sets SOCK_USE_WRITE_QUEUE.
1983  */
1984 void __sock_wfree(struct sk_buff *skb)
1985 {
1986 	struct sock *sk = skb->sk;
1987 
1988 	if (refcount_sub_and_test(skb->truesize, &sk->sk_wmem_alloc))
1989 		__sk_free(sk);
1990 }
1991 
1992 void skb_set_owner_w(struct sk_buff *skb, struct sock *sk)
1993 {
1994 	skb_orphan(skb);
1995 	skb->sk = sk;
1996 #ifdef CONFIG_INET
1997 	if (unlikely(!sk_fullsock(sk))) {
1998 		skb->destructor = sock_edemux;
1999 		sock_hold(sk);
2000 		return;
2001 	}
2002 #endif
2003 	skb->destructor = sock_wfree;
2004 	skb_set_hash_from_sk(skb, sk);
2005 	/*
2006 	 * We used to take a refcount on sk, but following operation
2007 	 * is enough to guarantee sk_free() wont free this sock until
2008 	 * all in-flight packets are completed
2009 	 */
2010 	refcount_add(skb->truesize, &sk->sk_wmem_alloc);
2011 }
2012 EXPORT_SYMBOL(skb_set_owner_w);
2013 
2014 static bool can_skb_orphan_partial(const struct sk_buff *skb)
2015 {
2016 #ifdef CONFIG_TLS_DEVICE
2017 	/* Drivers depend on in-order delivery for crypto offload,
2018 	 * partial orphan breaks out-of-order-OK logic.
2019 	 */
2020 	if (skb->decrypted)
2021 		return false;
2022 #endif
2023 	return (skb->destructor == sock_wfree ||
2024 		(IS_ENABLED(CONFIG_INET) && skb->destructor == tcp_wfree));
2025 }
2026 
2027 /* This helper is used by netem, as it can hold packets in its
2028  * delay queue. We want to allow the owner socket to send more
2029  * packets, as if they were already TX completed by a typical driver.
2030  * But we also want to keep skb->sk set because some packet schedulers
2031  * rely on it (sch_fq for example).
2032  */
2033 void skb_orphan_partial(struct sk_buff *skb)
2034 {
2035 	if (skb_is_tcp_pure_ack(skb))
2036 		return;
2037 
2038 	if (can_skb_orphan_partial(skb)) {
2039 		struct sock *sk = skb->sk;
2040 
2041 		if (refcount_inc_not_zero(&sk->sk_refcnt)) {
2042 			WARN_ON(refcount_sub_and_test(skb->truesize, &sk->sk_wmem_alloc));
2043 			skb->destructor = sock_efree;
2044 		}
2045 	} else {
2046 		skb_orphan(skb);
2047 	}
2048 }
2049 EXPORT_SYMBOL(skb_orphan_partial);
2050 
2051 /*
2052  * Read buffer destructor automatically called from kfree_skb.
2053  */
2054 void sock_rfree(struct sk_buff *skb)
2055 {
2056 	struct sock *sk = skb->sk;
2057 	unsigned int len = skb->truesize;
2058 
2059 	atomic_sub(len, &sk->sk_rmem_alloc);
2060 	sk_mem_uncharge(sk, len);
2061 }
2062 EXPORT_SYMBOL(sock_rfree);
2063 
2064 /*
2065  * Buffer destructor for skbs that are not used directly in read or write
2066  * path, e.g. for error handler skbs. Automatically called from kfree_skb.
2067  */
2068 void sock_efree(struct sk_buff *skb)
2069 {
2070 	sock_put(skb->sk);
2071 }
2072 EXPORT_SYMBOL(sock_efree);
2073 
2074 kuid_t sock_i_uid(struct sock *sk)
2075 {
2076 	kuid_t uid;
2077 
2078 	read_lock_bh(&sk->sk_callback_lock);
2079 	uid = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_uid : GLOBAL_ROOT_UID;
2080 	read_unlock_bh(&sk->sk_callback_lock);
2081 	return uid;
2082 }
2083 EXPORT_SYMBOL(sock_i_uid);
2084 
2085 unsigned long sock_i_ino(struct sock *sk)
2086 {
2087 	unsigned long ino;
2088 
2089 	read_lock_bh(&sk->sk_callback_lock);
2090 	ino = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_ino : 0;
2091 	read_unlock_bh(&sk->sk_callback_lock);
2092 	return ino;
2093 }
2094 EXPORT_SYMBOL(sock_i_ino);
2095 
2096 /*
2097  * Allocate a skb from the socket's send buffer.
2098  */
2099 struct sk_buff *sock_wmalloc(struct sock *sk, unsigned long size, int force,
2100 			     gfp_t priority)
2101 {
2102 	if (force ||
2103 	    refcount_read(&sk->sk_wmem_alloc) < READ_ONCE(sk->sk_sndbuf)) {
2104 		struct sk_buff *skb = alloc_skb(size, priority);
2105 
2106 		if (skb) {
2107 			skb_set_owner_w(skb, sk);
2108 			return skb;
2109 		}
2110 	}
2111 	return NULL;
2112 }
2113 EXPORT_SYMBOL(sock_wmalloc);
2114 
2115 static void sock_ofree(struct sk_buff *skb)
2116 {
2117 	struct sock *sk = skb->sk;
2118 
2119 	atomic_sub(skb->truesize, &sk->sk_omem_alloc);
2120 }
2121 
2122 struct sk_buff *sock_omalloc(struct sock *sk, unsigned long size,
2123 			     gfp_t priority)
2124 {
2125 	struct sk_buff *skb;
2126 
2127 	/* small safe race: SKB_TRUESIZE may differ from final skb->truesize */
2128 	if (atomic_read(&sk->sk_omem_alloc) + SKB_TRUESIZE(size) >
2129 	    sysctl_optmem_max)
2130 		return NULL;
2131 
2132 	skb = alloc_skb(size, priority);
2133 	if (!skb)
2134 		return NULL;
2135 
2136 	atomic_add(skb->truesize, &sk->sk_omem_alloc);
2137 	skb->sk = sk;
2138 	skb->destructor = sock_ofree;
2139 	return skb;
2140 }
2141 
2142 /*
2143  * Allocate a memory block from the socket's option memory buffer.
2144  */
2145 void *sock_kmalloc(struct sock *sk, int size, gfp_t priority)
2146 {
2147 	if ((unsigned int)size <= sysctl_optmem_max &&
2148 	    atomic_read(&sk->sk_omem_alloc) + size < sysctl_optmem_max) {
2149 		void *mem;
2150 		/* First do the add, to avoid the race if kmalloc
2151 		 * might sleep.
2152 		 */
2153 		atomic_add(size, &sk->sk_omem_alloc);
2154 		mem = kmalloc(size, priority);
2155 		if (mem)
2156 			return mem;
2157 		atomic_sub(size, &sk->sk_omem_alloc);
2158 	}
2159 	return NULL;
2160 }
2161 EXPORT_SYMBOL(sock_kmalloc);
2162 
2163 /* Free an option memory block. Note, we actually want the inline
2164  * here as this allows gcc to detect the nullify and fold away the
2165  * condition entirely.
2166  */
2167 static inline void __sock_kfree_s(struct sock *sk, void *mem, int size,
2168 				  const bool nullify)
2169 {
2170 	if (WARN_ON_ONCE(!mem))
2171 		return;
2172 	if (nullify)
2173 		kzfree(mem);
2174 	else
2175 		kfree(mem);
2176 	atomic_sub(size, &sk->sk_omem_alloc);
2177 }
2178 
2179 void sock_kfree_s(struct sock *sk, void *mem, int size)
2180 {
2181 	__sock_kfree_s(sk, mem, size, false);
2182 }
2183 EXPORT_SYMBOL(sock_kfree_s);
2184 
2185 void sock_kzfree_s(struct sock *sk, void *mem, int size)
2186 {
2187 	__sock_kfree_s(sk, mem, size, true);
2188 }
2189 EXPORT_SYMBOL(sock_kzfree_s);
2190 
2191 /* It is almost wait_for_tcp_memory minus release_sock/lock_sock.
2192    I think, these locks should be removed for datagram sockets.
2193  */
2194 static long sock_wait_for_wmem(struct sock *sk, long timeo)
2195 {
2196 	DEFINE_WAIT(wait);
2197 
2198 	sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
2199 	for (;;) {
2200 		if (!timeo)
2201 			break;
2202 		if (signal_pending(current))
2203 			break;
2204 		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
2205 		prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
2206 		if (refcount_read(&sk->sk_wmem_alloc) < READ_ONCE(sk->sk_sndbuf))
2207 			break;
2208 		if (sk->sk_shutdown & SEND_SHUTDOWN)
2209 			break;
2210 		if (sk->sk_err)
2211 			break;
2212 		timeo = schedule_timeout(timeo);
2213 	}
2214 	finish_wait(sk_sleep(sk), &wait);
2215 	return timeo;
2216 }
2217 
2218 
2219 /*
2220  *	Generic send/receive buffer handlers
2221  */
2222 
2223 struct sk_buff *sock_alloc_send_pskb(struct sock *sk, unsigned long header_len,
2224 				     unsigned long data_len, int noblock,
2225 				     int *errcode, int max_page_order)
2226 {
2227 	struct sk_buff *skb;
2228 	long timeo;
2229 	int err;
2230 
2231 	timeo = sock_sndtimeo(sk, noblock);
2232 	for (;;) {
2233 		err = sock_error(sk);
2234 		if (err != 0)
2235 			goto failure;
2236 
2237 		err = -EPIPE;
2238 		if (sk->sk_shutdown & SEND_SHUTDOWN)
2239 			goto failure;
2240 
2241 		if (sk_wmem_alloc_get(sk) < READ_ONCE(sk->sk_sndbuf))
2242 			break;
2243 
2244 		sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
2245 		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
2246 		err = -EAGAIN;
2247 		if (!timeo)
2248 			goto failure;
2249 		if (signal_pending(current))
2250 			goto interrupted;
2251 		timeo = sock_wait_for_wmem(sk, timeo);
2252 	}
2253 	skb = alloc_skb_with_frags(header_len, data_len, max_page_order,
2254 				   errcode, sk->sk_allocation);
2255 	if (skb)
2256 		skb_set_owner_w(skb, sk);
2257 	return skb;
2258 
2259 interrupted:
2260 	err = sock_intr_errno(timeo);
2261 failure:
2262 	*errcode = err;
2263 	return NULL;
2264 }
2265 EXPORT_SYMBOL(sock_alloc_send_pskb);
2266 
2267 struct sk_buff *sock_alloc_send_skb(struct sock *sk, unsigned long size,
2268 				    int noblock, int *errcode)
2269 {
2270 	return sock_alloc_send_pskb(sk, size, 0, noblock, errcode, 0);
2271 }
2272 EXPORT_SYMBOL(sock_alloc_send_skb);
2273 
2274 int __sock_cmsg_send(struct sock *sk, struct msghdr *msg, struct cmsghdr *cmsg,
2275 		     struct sockcm_cookie *sockc)
2276 {
2277 	u32 tsflags;
2278 
2279 	switch (cmsg->cmsg_type) {
2280 	case SO_MARK:
2281 		if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
2282 			return -EPERM;
2283 		if (cmsg->cmsg_len != CMSG_LEN(sizeof(u32)))
2284 			return -EINVAL;
2285 		sockc->mark = *(u32 *)CMSG_DATA(cmsg);
2286 		break;
2287 	case SO_TIMESTAMPING_OLD:
2288 		if (cmsg->cmsg_len != CMSG_LEN(sizeof(u32)))
2289 			return -EINVAL;
2290 
2291 		tsflags = *(u32 *)CMSG_DATA(cmsg);
2292 		if (tsflags & ~SOF_TIMESTAMPING_TX_RECORD_MASK)
2293 			return -EINVAL;
2294 
2295 		sockc->tsflags &= ~SOF_TIMESTAMPING_TX_RECORD_MASK;
2296 		sockc->tsflags |= tsflags;
2297 		break;
2298 	case SCM_TXTIME:
2299 		if (!sock_flag(sk, SOCK_TXTIME))
2300 			return -EINVAL;
2301 		if (cmsg->cmsg_len != CMSG_LEN(sizeof(u64)))
2302 			return -EINVAL;
2303 		sockc->transmit_time = get_unaligned((u64 *)CMSG_DATA(cmsg));
2304 		break;
2305 	/* SCM_RIGHTS and SCM_CREDENTIALS are semantically in SOL_UNIX. */
2306 	case SCM_RIGHTS:
2307 	case SCM_CREDENTIALS:
2308 		break;
2309 	default:
2310 		return -EINVAL;
2311 	}
2312 	return 0;
2313 }
2314 EXPORT_SYMBOL(__sock_cmsg_send);
2315 
2316 int sock_cmsg_send(struct sock *sk, struct msghdr *msg,
2317 		   struct sockcm_cookie *sockc)
2318 {
2319 	struct cmsghdr *cmsg;
2320 	int ret;
2321 
2322 	for_each_cmsghdr(cmsg, msg) {
2323 		if (!CMSG_OK(msg, cmsg))
2324 			return -EINVAL;
2325 		if (cmsg->cmsg_level != SOL_SOCKET)
2326 			continue;
2327 		ret = __sock_cmsg_send(sk, msg, cmsg, sockc);
2328 		if (ret)
2329 			return ret;
2330 	}
2331 	return 0;
2332 }
2333 EXPORT_SYMBOL(sock_cmsg_send);
2334 
2335 static void sk_enter_memory_pressure(struct sock *sk)
2336 {
2337 	if (!sk->sk_prot->enter_memory_pressure)
2338 		return;
2339 
2340 	sk->sk_prot->enter_memory_pressure(sk);
2341 }
2342 
2343 static void sk_leave_memory_pressure(struct sock *sk)
2344 {
2345 	if (sk->sk_prot->leave_memory_pressure) {
2346 		sk->sk_prot->leave_memory_pressure(sk);
2347 	} else {
2348 		unsigned long *memory_pressure = sk->sk_prot->memory_pressure;
2349 
2350 		if (memory_pressure && READ_ONCE(*memory_pressure))
2351 			WRITE_ONCE(*memory_pressure, 0);
2352 	}
2353 }
2354 
2355 /* On 32bit arches, an skb frag is limited to 2^15 */
2356 #define SKB_FRAG_PAGE_ORDER	get_order(32768)
2357 DEFINE_STATIC_KEY_FALSE(net_high_order_alloc_disable_key);
2358 
2359 /**
2360  * skb_page_frag_refill - check that a page_frag contains enough room
2361  * @sz: minimum size of the fragment we want to get
2362  * @pfrag: pointer to page_frag
2363  * @gfp: priority for memory allocation
2364  *
2365  * Note: While this allocator tries to use high order pages, there is
2366  * no guarantee that allocations succeed. Therefore, @sz MUST be
2367  * less or equal than PAGE_SIZE.
2368  */
2369 bool skb_page_frag_refill(unsigned int sz, struct page_frag *pfrag, gfp_t gfp)
2370 {
2371 	if (pfrag->page) {
2372 		if (page_ref_count(pfrag->page) == 1) {
2373 			pfrag->offset = 0;
2374 			return true;
2375 		}
2376 		if (pfrag->offset + sz <= pfrag->size)
2377 			return true;
2378 		put_page(pfrag->page);
2379 	}
2380 
2381 	pfrag->offset = 0;
2382 	if (SKB_FRAG_PAGE_ORDER &&
2383 	    !static_branch_unlikely(&net_high_order_alloc_disable_key)) {
2384 		/* Avoid direct reclaim but allow kswapd to wake */
2385 		pfrag->page = alloc_pages((gfp & ~__GFP_DIRECT_RECLAIM) |
2386 					  __GFP_COMP | __GFP_NOWARN |
2387 					  __GFP_NORETRY,
2388 					  SKB_FRAG_PAGE_ORDER);
2389 		if (likely(pfrag->page)) {
2390 			pfrag->size = PAGE_SIZE << SKB_FRAG_PAGE_ORDER;
2391 			return true;
2392 		}
2393 	}
2394 	pfrag->page = alloc_page(gfp);
2395 	if (likely(pfrag->page)) {
2396 		pfrag->size = PAGE_SIZE;
2397 		return true;
2398 	}
2399 	return false;
2400 }
2401 EXPORT_SYMBOL(skb_page_frag_refill);
2402 
2403 bool sk_page_frag_refill(struct sock *sk, struct page_frag *pfrag)
2404 {
2405 	if (likely(skb_page_frag_refill(32U, pfrag, sk->sk_allocation)))
2406 		return true;
2407 
2408 	sk_enter_memory_pressure(sk);
2409 	sk_stream_moderate_sndbuf(sk);
2410 	return false;
2411 }
2412 EXPORT_SYMBOL(sk_page_frag_refill);
2413 
2414 static void __lock_sock(struct sock *sk)
2415 	__releases(&sk->sk_lock.slock)
2416 	__acquires(&sk->sk_lock.slock)
2417 {
2418 	DEFINE_WAIT(wait);
2419 
2420 	for (;;) {
2421 		prepare_to_wait_exclusive(&sk->sk_lock.wq, &wait,
2422 					TASK_UNINTERRUPTIBLE);
2423 		spin_unlock_bh(&sk->sk_lock.slock);
2424 		schedule();
2425 		spin_lock_bh(&sk->sk_lock.slock);
2426 		if (!sock_owned_by_user(sk))
2427 			break;
2428 	}
2429 	finish_wait(&sk->sk_lock.wq, &wait);
2430 }
2431 
2432 void __release_sock(struct sock *sk)
2433 	__releases(&sk->sk_lock.slock)
2434 	__acquires(&sk->sk_lock.slock)
2435 {
2436 	struct sk_buff *skb, *next;
2437 
2438 	while ((skb = sk->sk_backlog.head) != NULL) {
2439 		sk->sk_backlog.head = sk->sk_backlog.tail = NULL;
2440 
2441 		spin_unlock_bh(&sk->sk_lock.slock);
2442 
2443 		do {
2444 			next = skb->next;
2445 			prefetch(next);
2446 			WARN_ON_ONCE(skb_dst_is_noref(skb));
2447 			skb_mark_not_on_list(skb);
2448 			sk_backlog_rcv(sk, skb);
2449 
2450 			cond_resched();
2451 
2452 			skb = next;
2453 		} while (skb != NULL);
2454 
2455 		spin_lock_bh(&sk->sk_lock.slock);
2456 	}
2457 
2458 	/*
2459 	 * Doing the zeroing here guarantee we can not loop forever
2460 	 * while a wild producer attempts to flood us.
2461 	 */
2462 	sk->sk_backlog.len = 0;
2463 }
2464 
2465 void __sk_flush_backlog(struct sock *sk)
2466 {
2467 	spin_lock_bh(&sk->sk_lock.slock);
2468 	__release_sock(sk);
2469 	spin_unlock_bh(&sk->sk_lock.slock);
2470 }
2471 
2472 /**
2473  * sk_wait_data - wait for data to arrive at sk_receive_queue
2474  * @sk:    sock to wait on
2475  * @timeo: for how long
2476  * @skb:   last skb seen on sk_receive_queue
2477  *
2478  * Now socket state including sk->sk_err is changed only under lock,
2479  * hence we may omit checks after joining wait queue.
2480  * We check receive queue before schedule() only as optimization;
2481  * it is very likely that release_sock() added new data.
2482  */
2483 int sk_wait_data(struct sock *sk, long *timeo, const struct sk_buff *skb)
2484 {
2485 	DEFINE_WAIT_FUNC(wait, woken_wake_function);
2486 	int rc;
2487 
2488 	add_wait_queue(sk_sleep(sk), &wait);
2489 	sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
2490 	rc = sk_wait_event(sk, timeo, skb_peek_tail(&sk->sk_receive_queue) != skb, &wait);
2491 	sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
2492 	remove_wait_queue(sk_sleep(sk), &wait);
2493 	return rc;
2494 }
2495 EXPORT_SYMBOL(sk_wait_data);
2496 
2497 /**
2498  *	__sk_mem_raise_allocated - increase memory_allocated
2499  *	@sk: socket
2500  *	@size: memory size to allocate
2501  *	@amt: pages to allocate
2502  *	@kind: allocation type
2503  *
2504  *	Similar to __sk_mem_schedule(), but does not update sk_forward_alloc
2505  */
2506 int __sk_mem_raise_allocated(struct sock *sk, int size, int amt, int kind)
2507 {
2508 	struct proto *prot = sk->sk_prot;
2509 	long allocated = sk_memory_allocated_add(sk, amt);
2510 	bool charged = true;
2511 
2512 	if (mem_cgroup_sockets_enabled && sk->sk_memcg &&
2513 	    !(charged = mem_cgroup_charge_skmem(sk->sk_memcg, amt)))
2514 		goto suppress_allocation;
2515 
2516 	/* Under limit. */
2517 	if (allocated <= sk_prot_mem_limits(sk, 0)) {
2518 		sk_leave_memory_pressure(sk);
2519 		return 1;
2520 	}
2521 
2522 	/* Under pressure. */
2523 	if (allocated > sk_prot_mem_limits(sk, 1))
2524 		sk_enter_memory_pressure(sk);
2525 
2526 	/* Over hard limit. */
2527 	if (allocated > sk_prot_mem_limits(sk, 2))
2528 		goto suppress_allocation;
2529 
2530 	/* guarantee minimum buffer size under pressure */
2531 	if (kind == SK_MEM_RECV) {
2532 		if (atomic_read(&sk->sk_rmem_alloc) < sk_get_rmem0(sk, prot))
2533 			return 1;
2534 
2535 	} else { /* SK_MEM_SEND */
2536 		int wmem0 = sk_get_wmem0(sk, prot);
2537 
2538 		if (sk->sk_type == SOCK_STREAM) {
2539 			if (sk->sk_wmem_queued < wmem0)
2540 				return 1;
2541 		} else if (refcount_read(&sk->sk_wmem_alloc) < wmem0) {
2542 				return 1;
2543 		}
2544 	}
2545 
2546 	if (sk_has_memory_pressure(sk)) {
2547 		u64 alloc;
2548 
2549 		if (!sk_under_memory_pressure(sk))
2550 			return 1;
2551 		alloc = sk_sockets_allocated_read_positive(sk);
2552 		if (sk_prot_mem_limits(sk, 2) > alloc *
2553 		    sk_mem_pages(sk->sk_wmem_queued +
2554 				 atomic_read(&sk->sk_rmem_alloc) +
2555 				 sk->sk_forward_alloc))
2556 			return 1;
2557 	}
2558 
2559 suppress_allocation:
2560 
2561 	if (kind == SK_MEM_SEND && sk->sk_type == SOCK_STREAM) {
2562 		sk_stream_moderate_sndbuf(sk);
2563 
2564 		/* Fail only if socket is _under_ its sndbuf.
2565 		 * In this case we cannot block, so that we have to fail.
2566 		 */
2567 		if (sk->sk_wmem_queued + size >= sk->sk_sndbuf)
2568 			return 1;
2569 	}
2570 
2571 	if (kind == SK_MEM_SEND || (kind == SK_MEM_RECV && charged))
2572 		trace_sock_exceed_buf_limit(sk, prot, allocated, kind);
2573 
2574 	sk_memory_allocated_sub(sk, amt);
2575 
2576 	if (mem_cgroup_sockets_enabled && sk->sk_memcg)
2577 		mem_cgroup_uncharge_skmem(sk->sk_memcg, amt);
2578 
2579 	return 0;
2580 }
2581 EXPORT_SYMBOL(__sk_mem_raise_allocated);
2582 
2583 /**
2584  *	__sk_mem_schedule - increase sk_forward_alloc and memory_allocated
2585  *	@sk: socket
2586  *	@size: memory size to allocate
2587  *	@kind: allocation type
2588  *
2589  *	If kind is SK_MEM_SEND, it means wmem allocation. Otherwise it means
2590  *	rmem allocation. This function assumes that protocols which have
2591  *	memory_pressure use sk_wmem_queued as write buffer accounting.
2592  */
2593 int __sk_mem_schedule(struct sock *sk, int size, int kind)
2594 {
2595 	int ret, amt = sk_mem_pages(size);
2596 
2597 	sk->sk_forward_alloc += amt << SK_MEM_QUANTUM_SHIFT;
2598 	ret = __sk_mem_raise_allocated(sk, size, amt, kind);
2599 	if (!ret)
2600 		sk->sk_forward_alloc -= amt << SK_MEM_QUANTUM_SHIFT;
2601 	return ret;
2602 }
2603 EXPORT_SYMBOL(__sk_mem_schedule);
2604 
2605 /**
2606  *	__sk_mem_reduce_allocated - reclaim memory_allocated
2607  *	@sk: socket
2608  *	@amount: number of quanta
2609  *
2610  *	Similar to __sk_mem_reclaim(), but does not update sk_forward_alloc
2611  */
2612 void __sk_mem_reduce_allocated(struct sock *sk, int amount)
2613 {
2614 	sk_memory_allocated_sub(sk, amount);
2615 
2616 	if (mem_cgroup_sockets_enabled && sk->sk_memcg)
2617 		mem_cgroup_uncharge_skmem(sk->sk_memcg, amount);
2618 
2619 	if (sk_under_memory_pressure(sk) &&
2620 	    (sk_memory_allocated(sk) < sk_prot_mem_limits(sk, 0)))
2621 		sk_leave_memory_pressure(sk);
2622 }
2623 EXPORT_SYMBOL(__sk_mem_reduce_allocated);
2624 
2625 /**
2626  *	__sk_mem_reclaim - reclaim sk_forward_alloc and memory_allocated
2627  *	@sk: socket
2628  *	@amount: number of bytes (rounded down to a SK_MEM_QUANTUM multiple)
2629  */
2630 void __sk_mem_reclaim(struct sock *sk, int amount)
2631 {
2632 	amount >>= SK_MEM_QUANTUM_SHIFT;
2633 	sk->sk_forward_alloc -= amount << SK_MEM_QUANTUM_SHIFT;
2634 	__sk_mem_reduce_allocated(sk, amount);
2635 }
2636 EXPORT_SYMBOL(__sk_mem_reclaim);
2637 
2638 int sk_set_peek_off(struct sock *sk, int val)
2639 {
2640 	sk->sk_peek_off = val;
2641 	return 0;
2642 }
2643 EXPORT_SYMBOL_GPL(sk_set_peek_off);
2644 
2645 /*
2646  * Set of default routines for initialising struct proto_ops when
2647  * the protocol does not support a particular function. In certain
2648  * cases where it makes no sense for a protocol to have a "do nothing"
2649  * function, some default processing is provided.
2650  */
2651 
2652 int sock_no_bind(struct socket *sock, struct sockaddr *saddr, int len)
2653 {
2654 	return -EOPNOTSUPP;
2655 }
2656 EXPORT_SYMBOL(sock_no_bind);
2657 
2658 int sock_no_connect(struct socket *sock, struct sockaddr *saddr,
2659 		    int len, int flags)
2660 {
2661 	return -EOPNOTSUPP;
2662 }
2663 EXPORT_SYMBOL(sock_no_connect);
2664 
2665 int sock_no_socketpair(struct socket *sock1, struct socket *sock2)
2666 {
2667 	return -EOPNOTSUPP;
2668 }
2669 EXPORT_SYMBOL(sock_no_socketpair);
2670 
2671 int sock_no_accept(struct socket *sock, struct socket *newsock, int flags,
2672 		   bool kern)
2673 {
2674 	return -EOPNOTSUPP;
2675 }
2676 EXPORT_SYMBOL(sock_no_accept);
2677 
2678 int sock_no_getname(struct socket *sock, struct sockaddr *saddr,
2679 		    int peer)
2680 {
2681 	return -EOPNOTSUPP;
2682 }
2683 EXPORT_SYMBOL(sock_no_getname);
2684 
2685 int sock_no_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
2686 {
2687 	return -EOPNOTSUPP;
2688 }
2689 EXPORT_SYMBOL(sock_no_ioctl);
2690 
2691 int sock_no_listen(struct socket *sock, int backlog)
2692 {
2693 	return -EOPNOTSUPP;
2694 }
2695 EXPORT_SYMBOL(sock_no_listen);
2696 
2697 int sock_no_shutdown(struct socket *sock, int how)
2698 {
2699 	return -EOPNOTSUPP;
2700 }
2701 EXPORT_SYMBOL(sock_no_shutdown);
2702 
2703 int sock_no_setsockopt(struct socket *sock, int level, int optname,
2704 		    char __user *optval, unsigned int optlen)
2705 {
2706 	return -EOPNOTSUPP;
2707 }
2708 EXPORT_SYMBOL(sock_no_setsockopt);
2709 
2710 int sock_no_getsockopt(struct socket *sock, int level, int optname,
2711 		    char __user *optval, int __user *optlen)
2712 {
2713 	return -EOPNOTSUPP;
2714 }
2715 EXPORT_SYMBOL(sock_no_getsockopt);
2716 
2717 int sock_no_sendmsg(struct socket *sock, struct msghdr *m, size_t len)
2718 {
2719 	return -EOPNOTSUPP;
2720 }
2721 EXPORT_SYMBOL(sock_no_sendmsg);
2722 
2723 int sock_no_sendmsg_locked(struct sock *sk, struct msghdr *m, size_t len)
2724 {
2725 	return -EOPNOTSUPP;
2726 }
2727 EXPORT_SYMBOL(sock_no_sendmsg_locked);
2728 
2729 int sock_no_recvmsg(struct socket *sock, struct msghdr *m, size_t len,
2730 		    int flags)
2731 {
2732 	return -EOPNOTSUPP;
2733 }
2734 EXPORT_SYMBOL(sock_no_recvmsg);
2735 
2736 int sock_no_mmap(struct file *file, struct socket *sock, struct vm_area_struct *vma)
2737 {
2738 	/* Mirror missing mmap method error code */
2739 	return -ENODEV;
2740 }
2741 EXPORT_SYMBOL(sock_no_mmap);
2742 
2743 ssize_t sock_no_sendpage(struct socket *sock, struct page *page, int offset, size_t size, int flags)
2744 {
2745 	ssize_t res;
2746 	struct msghdr msg = {.msg_flags = flags};
2747 	struct kvec iov;
2748 	char *kaddr = kmap(page);
2749 	iov.iov_base = kaddr + offset;
2750 	iov.iov_len = size;
2751 	res = kernel_sendmsg(sock, &msg, &iov, 1, size);
2752 	kunmap(page);
2753 	return res;
2754 }
2755 EXPORT_SYMBOL(sock_no_sendpage);
2756 
2757 ssize_t sock_no_sendpage_locked(struct sock *sk, struct page *page,
2758 				int offset, size_t size, int flags)
2759 {
2760 	ssize_t res;
2761 	struct msghdr msg = {.msg_flags = flags};
2762 	struct kvec iov;
2763 	char *kaddr = kmap(page);
2764 
2765 	iov.iov_base = kaddr + offset;
2766 	iov.iov_len = size;
2767 	res = kernel_sendmsg_locked(sk, &msg, &iov, 1, size);
2768 	kunmap(page);
2769 	return res;
2770 }
2771 EXPORT_SYMBOL(sock_no_sendpage_locked);
2772 
2773 /*
2774  *	Default Socket Callbacks
2775  */
2776 
2777 static void sock_def_wakeup(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_all(&wq->wait);
2785 	rcu_read_unlock();
2786 }
2787 
2788 static void sock_def_error_report(struct sock *sk)
2789 {
2790 	struct socket_wq *wq;
2791 
2792 	rcu_read_lock();
2793 	wq = rcu_dereference(sk->sk_wq);
2794 	if (skwq_has_sleeper(wq))
2795 		wake_up_interruptible_poll(&wq->wait, EPOLLERR);
2796 	sk_wake_async(sk, SOCK_WAKE_IO, POLL_ERR);
2797 	rcu_read_unlock();
2798 }
2799 
2800 void sock_def_readable(struct sock *sk)
2801 {
2802 	struct socket_wq *wq;
2803 
2804 	rcu_read_lock();
2805 	wq = rcu_dereference(sk->sk_wq);
2806 	if (skwq_has_sleeper(wq))
2807 		wake_up_interruptible_sync_poll(&wq->wait, EPOLLIN | EPOLLPRI |
2808 						EPOLLRDNORM | EPOLLRDBAND);
2809 	sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
2810 	rcu_read_unlock();
2811 }
2812 
2813 static void sock_def_write_space(struct sock *sk)
2814 {
2815 	struct socket_wq *wq;
2816 
2817 	rcu_read_lock();
2818 
2819 	/* Do not wake up a writer until he can make "significant"
2820 	 * progress.  --DaveM
2821 	 */
2822 	if ((refcount_read(&sk->sk_wmem_alloc) << 1) <= READ_ONCE(sk->sk_sndbuf)) {
2823 		wq = rcu_dereference(sk->sk_wq);
2824 		if (skwq_has_sleeper(wq))
2825 			wake_up_interruptible_sync_poll(&wq->wait, EPOLLOUT |
2826 						EPOLLWRNORM | EPOLLWRBAND);
2827 
2828 		/* Should agree with poll, otherwise some programs break */
2829 		if (sock_writeable(sk))
2830 			sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
2831 	}
2832 
2833 	rcu_read_unlock();
2834 }
2835 
2836 static void sock_def_destruct(struct sock *sk)
2837 {
2838 }
2839 
2840 void sk_send_sigurg(struct sock *sk)
2841 {
2842 	if (sk->sk_socket && sk->sk_socket->file)
2843 		if (send_sigurg(&sk->sk_socket->file->f_owner))
2844 			sk_wake_async(sk, SOCK_WAKE_URG, POLL_PRI);
2845 }
2846 EXPORT_SYMBOL(sk_send_sigurg);
2847 
2848 void sk_reset_timer(struct sock *sk, struct timer_list* timer,
2849 		    unsigned long expires)
2850 {
2851 	if (!mod_timer(timer, expires))
2852 		sock_hold(sk);
2853 }
2854 EXPORT_SYMBOL(sk_reset_timer);
2855 
2856 void sk_stop_timer(struct sock *sk, struct timer_list* timer)
2857 {
2858 	if (del_timer(timer))
2859 		__sock_put(sk);
2860 }
2861 EXPORT_SYMBOL(sk_stop_timer);
2862 
2863 void sock_init_data(struct socket *sock, struct sock *sk)
2864 {
2865 	sk_init_common(sk);
2866 	sk->sk_send_head	=	NULL;
2867 
2868 	timer_setup(&sk->sk_timer, NULL, 0);
2869 
2870 	sk->sk_allocation	=	GFP_KERNEL;
2871 	sk->sk_rcvbuf		=	sysctl_rmem_default;
2872 	sk->sk_sndbuf		=	sysctl_wmem_default;
2873 	sk->sk_state		=	TCP_CLOSE;
2874 	sk_set_socket(sk, sock);
2875 
2876 	sock_set_flag(sk, SOCK_ZAPPED);
2877 
2878 	if (sock) {
2879 		sk->sk_type	=	sock->type;
2880 		RCU_INIT_POINTER(sk->sk_wq, &sock->wq);
2881 		sock->sk	=	sk;
2882 		sk->sk_uid	=	SOCK_INODE(sock)->i_uid;
2883 	} else {
2884 		RCU_INIT_POINTER(sk->sk_wq, NULL);
2885 		sk->sk_uid	=	make_kuid(sock_net(sk)->user_ns, 0);
2886 	}
2887 
2888 	rwlock_init(&sk->sk_callback_lock);
2889 	if (sk->sk_kern_sock)
2890 		lockdep_set_class_and_name(
2891 			&sk->sk_callback_lock,
2892 			af_kern_callback_keys + sk->sk_family,
2893 			af_family_kern_clock_key_strings[sk->sk_family]);
2894 	else
2895 		lockdep_set_class_and_name(
2896 			&sk->sk_callback_lock,
2897 			af_callback_keys + sk->sk_family,
2898 			af_family_clock_key_strings[sk->sk_family]);
2899 
2900 	sk->sk_state_change	=	sock_def_wakeup;
2901 	sk->sk_data_ready	=	sock_def_readable;
2902 	sk->sk_write_space	=	sock_def_write_space;
2903 	sk->sk_error_report	=	sock_def_error_report;
2904 	sk->sk_destruct		=	sock_def_destruct;
2905 
2906 	sk->sk_frag.page	=	NULL;
2907 	sk->sk_frag.offset	=	0;
2908 	sk->sk_peek_off		=	-1;
2909 
2910 	sk->sk_peer_pid 	=	NULL;
2911 	sk->sk_peer_cred	=	NULL;
2912 	sk->sk_write_pending	=	0;
2913 	sk->sk_rcvlowat		=	1;
2914 	sk->sk_rcvtimeo		=	MAX_SCHEDULE_TIMEOUT;
2915 	sk->sk_sndtimeo		=	MAX_SCHEDULE_TIMEOUT;
2916 
2917 	sk->sk_stamp = SK_DEFAULT_STAMP;
2918 #if BITS_PER_LONG==32
2919 	seqlock_init(&sk->sk_stamp_seq);
2920 #endif
2921 	atomic_set(&sk->sk_zckey, 0);
2922 
2923 #ifdef CONFIG_NET_RX_BUSY_POLL
2924 	sk->sk_napi_id		=	0;
2925 	sk->sk_ll_usec		=	sysctl_net_busy_read;
2926 #endif
2927 
2928 	sk->sk_max_pacing_rate = ~0UL;
2929 	sk->sk_pacing_rate = ~0UL;
2930 	WRITE_ONCE(sk->sk_pacing_shift, 10);
2931 	sk->sk_incoming_cpu = -1;
2932 
2933 	sk_rx_queue_clear(sk);
2934 	/*
2935 	 * Before updating sk_refcnt, we must commit prior changes to memory
2936 	 * (Documentation/RCU/rculist_nulls.txt for details)
2937 	 */
2938 	smp_wmb();
2939 	refcount_set(&sk->sk_refcnt, 1);
2940 	atomic_set(&sk->sk_drops, 0);
2941 }
2942 EXPORT_SYMBOL(sock_init_data);
2943 
2944 void lock_sock_nested(struct sock *sk, int subclass)
2945 {
2946 	might_sleep();
2947 	spin_lock_bh(&sk->sk_lock.slock);
2948 	if (sk->sk_lock.owned)
2949 		__lock_sock(sk);
2950 	sk->sk_lock.owned = 1;
2951 	spin_unlock(&sk->sk_lock.slock);
2952 	/*
2953 	 * The sk_lock has mutex_lock() semantics here:
2954 	 */
2955 	mutex_acquire(&sk->sk_lock.dep_map, subclass, 0, _RET_IP_);
2956 	local_bh_enable();
2957 }
2958 EXPORT_SYMBOL(lock_sock_nested);
2959 
2960 void release_sock(struct sock *sk)
2961 {
2962 	spin_lock_bh(&sk->sk_lock.slock);
2963 	if (sk->sk_backlog.tail)
2964 		__release_sock(sk);
2965 
2966 	/* Warning : release_cb() might need to release sk ownership,
2967 	 * ie call sock_release_ownership(sk) before us.
2968 	 */
2969 	if (sk->sk_prot->release_cb)
2970 		sk->sk_prot->release_cb(sk);
2971 
2972 	sock_release_ownership(sk);
2973 	if (waitqueue_active(&sk->sk_lock.wq))
2974 		wake_up(&sk->sk_lock.wq);
2975 	spin_unlock_bh(&sk->sk_lock.slock);
2976 }
2977 EXPORT_SYMBOL(release_sock);
2978 
2979 /**
2980  * lock_sock_fast - fast version of lock_sock
2981  * @sk: socket
2982  *
2983  * This version should be used for very small section, where process wont block
2984  * return false if fast path is taken:
2985  *
2986  *   sk_lock.slock locked, owned = 0, BH disabled
2987  *
2988  * return true if slow path is taken:
2989  *
2990  *   sk_lock.slock unlocked, owned = 1, BH enabled
2991  */
2992 bool lock_sock_fast(struct sock *sk)
2993 {
2994 	might_sleep();
2995 	spin_lock_bh(&sk->sk_lock.slock);
2996 
2997 	if (!sk->sk_lock.owned)
2998 		/*
2999 		 * Note : We must disable BH
3000 		 */
3001 		return false;
3002 
3003 	__lock_sock(sk);
3004 	sk->sk_lock.owned = 1;
3005 	spin_unlock(&sk->sk_lock.slock);
3006 	/*
3007 	 * The sk_lock has mutex_lock() semantics here:
3008 	 */
3009 	mutex_acquire(&sk->sk_lock.dep_map, 0, 0, _RET_IP_);
3010 	local_bh_enable();
3011 	return true;
3012 }
3013 EXPORT_SYMBOL(lock_sock_fast);
3014 
3015 int sock_gettstamp(struct socket *sock, void __user *userstamp,
3016 		   bool timeval, bool time32)
3017 {
3018 	struct sock *sk = sock->sk;
3019 	struct timespec64 ts;
3020 
3021 	sock_enable_timestamp(sk, SOCK_TIMESTAMP);
3022 	ts = ktime_to_timespec64(sock_read_timestamp(sk));
3023 	if (ts.tv_sec == -1)
3024 		return -ENOENT;
3025 	if (ts.tv_sec == 0) {
3026 		ktime_t kt = ktime_get_real();
3027 		sock_write_timestamp(sk, kt);
3028 		ts = ktime_to_timespec64(kt);
3029 	}
3030 
3031 	if (timeval)
3032 		ts.tv_nsec /= 1000;
3033 
3034 #ifdef CONFIG_COMPAT_32BIT_TIME
3035 	if (time32)
3036 		return put_old_timespec32(&ts, userstamp);
3037 #endif
3038 #ifdef CONFIG_SPARC64
3039 	/* beware of padding in sparc64 timeval */
3040 	if (timeval && !in_compat_syscall()) {
3041 		struct __kernel_old_timeval __user tv = {
3042 			.tv_sec = ts.tv_sec,
3043 			.tv_usec = ts.tv_nsec,
3044 		};
3045 		if (copy_to_user(userstamp, &tv, sizeof(tv)))
3046 			return -EFAULT;
3047 		return 0;
3048 	}
3049 #endif
3050 	return put_timespec64(&ts, userstamp);
3051 }
3052 EXPORT_SYMBOL(sock_gettstamp);
3053 
3054 void sock_enable_timestamp(struct sock *sk, enum sock_flags flag)
3055 {
3056 	if (!sock_flag(sk, flag)) {
3057 		unsigned long previous_flags = sk->sk_flags;
3058 
3059 		sock_set_flag(sk, flag);
3060 		/*
3061 		 * we just set one of the two flags which require net
3062 		 * time stamping, but time stamping might have been on
3063 		 * already because of the other one
3064 		 */
3065 		if (sock_needs_netstamp(sk) &&
3066 		    !(previous_flags & SK_FLAGS_TIMESTAMP))
3067 			net_enable_timestamp();
3068 	}
3069 }
3070 
3071 int sock_recv_errqueue(struct sock *sk, struct msghdr *msg, int len,
3072 		       int level, int type)
3073 {
3074 	struct sock_exterr_skb *serr;
3075 	struct sk_buff *skb;
3076 	int copied, err;
3077 
3078 	err = -EAGAIN;
3079 	skb = sock_dequeue_err_skb(sk);
3080 	if (skb == NULL)
3081 		goto out;
3082 
3083 	copied = skb->len;
3084 	if (copied > len) {
3085 		msg->msg_flags |= MSG_TRUNC;
3086 		copied = len;
3087 	}
3088 	err = skb_copy_datagram_msg(skb, 0, msg, copied);
3089 	if (err)
3090 		goto out_free_skb;
3091 
3092 	sock_recv_timestamp(msg, sk, skb);
3093 
3094 	serr = SKB_EXT_ERR(skb);
3095 	put_cmsg(msg, level, type, sizeof(serr->ee), &serr->ee);
3096 
3097 	msg->msg_flags |= MSG_ERRQUEUE;
3098 	err = copied;
3099 
3100 out_free_skb:
3101 	kfree_skb(skb);
3102 out:
3103 	return err;
3104 }
3105 EXPORT_SYMBOL(sock_recv_errqueue);
3106 
3107 /*
3108  *	Get a socket option on an socket.
3109  *
3110  *	FIX: POSIX 1003.1g is very ambiguous here. It states that
3111  *	asynchronous errors should be reported by getsockopt. We assume
3112  *	this means if you specify SO_ERROR (otherwise whats the point of it).
3113  */
3114 int sock_common_getsockopt(struct socket *sock, int level, int optname,
3115 			   char __user *optval, int __user *optlen)
3116 {
3117 	struct sock *sk = sock->sk;
3118 
3119 	return sk->sk_prot->getsockopt(sk, level, optname, optval, optlen);
3120 }
3121 EXPORT_SYMBOL(sock_common_getsockopt);
3122 
3123 #ifdef CONFIG_COMPAT
3124 int compat_sock_common_getsockopt(struct socket *sock, int level, int optname,
3125 				  char __user *optval, int __user *optlen)
3126 {
3127 	struct sock *sk = sock->sk;
3128 
3129 	if (sk->sk_prot->compat_getsockopt != NULL)
3130 		return sk->sk_prot->compat_getsockopt(sk, level, optname,
3131 						      optval, optlen);
3132 	return sk->sk_prot->getsockopt(sk, level, optname, optval, optlen);
3133 }
3134 EXPORT_SYMBOL(compat_sock_common_getsockopt);
3135 #endif
3136 
3137 int sock_common_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
3138 			int flags)
3139 {
3140 	struct sock *sk = sock->sk;
3141 	int addr_len = 0;
3142 	int err;
3143 
3144 	err = sk->sk_prot->recvmsg(sk, msg, size, flags & MSG_DONTWAIT,
3145 				   flags & ~MSG_DONTWAIT, &addr_len);
3146 	if (err >= 0)
3147 		msg->msg_namelen = addr_len;
3148 	return err;
3149 }
3150 EXPORT_SYMBOL(sock_common_recvmsg);
3151 
3152 /*
3153  *	Set socket options on an inet socket.
3154  */
3155 int sock_common_setsockopt(struct socket *sock, int level, int optname,
3156 			   char __user *optval, unsigned int optlen)
3157 {
3158 	struct sock *sk = sock->sk;
3159 
3160 	return sk->sk_prot->setsockopt(sk, level, optname, optval, optlen);
3161 }
3162 EXPORT_SYMBOL(sock_common_setsockopt);
3163 
3164 #ifdef CONFIG_COMPAT
3165 int compat_sock_common_setsockopt(struct socket *sock, int level, int optname,
3166 				  char __user *optval, unsigned int optlen)
3167 {
3168 	struct sock *sk = sock->sk;
3169 
3170 	if (sk->sk_prot->compat_setsockopt != NULL)
3171 		return sk->sk_prot->compat_setsockopt(sk, level, optname,
3172 						      optval, optlen);
3173 	return sk->sk_prot->setsockopt(sk, level, optname, optval, optlen);
3174 }
3175 EXPORT_SYMBOL(compat_sock_common_setsockopt);
3176 #endif
3177 
3178 void sk_common_release(struct sock *sk)
3179 {
3180 	if (sk->sk_prot->destroy)
3181 		sk->sk_prot->destroy(sk);
3182 
3183 	/*
3184 	 * Observation: when sock_common_release is called, processes have
3185 	 * no access to socket. But net still has.
3186 	 * Step one, detach it from networking:
3187 	 *
3188 	 * A. Remove from hash tables.
3189 	 */
3190 
3191 	sk->sk_prot->unhash(sk);
3192 
3193 	/*
3194 	 * In this point socket cannot receive new packets, but it is possible
3195 	 * that some packets are in flight because some CPU runs receiver and
3196 	 * did hash table lookup before we unhashed socket. They will achieve
3197 	 * receive queue and will be purged by socket destructor.
3198 	 *
3199 	 * Also we still have packets pending on receive queue and probably,
3200 	 * our own packets waiting in device queues. sock_destroy will drain
3201 	 * receive queue, but transmitted packets will delay socket destruction
3202 	 * until the last reference will be released.
3203 	 */
3204 
3205 	sock_orphan(sk);
3206 
3207 	xfrm_sk_free_policy(sk);
3208 
3209 	sk_refcnt_debug_release(sk);
3210 
3211 	sock_put(sk);
3212 }
3213 EXPORT_SYMBOL(sk_common_release);
3214 
3215 void sk_get_meminfo(const struct sock *sk, u32 *mem)
3216 {
3217 	memset(mem, 0, sizeof(*mem) * SK_MEMINFO_VARS);
3218 
3219 	mem[SK_MEMINFO_RMEM_ALLOC] = sk_rmem_alloc_get(sk);
3220 	mem[SK_MEMINFO_RCVBUF] = READ_ONCE(sk->sk_rcvbuf);
3221 	mem[SK_MEMINFO_WMEM_ALLOC] = sk_wmem_alloc_get(sk);
3222 	mem[SK_MEMINFO_SNDBUF] = READ_ONCE(sk->sk_sndbuf);
3223 	mem[SK_MEMINFO_FWD_ALLOC] = sk->sk_forward_alloc;
3224 	mem[SK_MEMINFO_WMEM_QUEUED] = READ_ONCE(sk->sk_wmem_queued);
3225 	mem[SK_MEMINFO_OPTMEM] = atomic_read(&sk->sk_omem_alloc);
3226 	mem[SK_MEMINFO_BACKLOG] = READ_ONCE(sk->sk_backlog.len);
3227 	mem[SK_MEMINFO_DROPS] = atomic_read(&sk->sk_drops);
3228 }
3229 
3230 #ifdef CONFIG_PROC_FS
3231 #define PROTO_INUSE_NR	64	/* should be enough for the first time */
3232 struct prot_inuse {
3233 	int val[PROTO_INUSE_NR];
3234 };
3235 
3236 static DECLARE_BITMAP(proto_inuse_idx, PROTO_INUSE_NR);
3237 
3238 void sock_prot_inuse_add(struct net *net, struct proto *prot, int val)
3239 {
3240 	__this_cpu_add(net->core.prot_inuse->val[prot->inuse_idx], val);
3241 }
3242 EXPORT_SYMBOL_GPL(sock_prot_inuse_add);
3243 
3244 int sock_prot_inuse_get(struct net *net, struct proto *prot)
3245 {
3246 	int cpu, idx = prot->inuse_idx;
3247 	int res = 0;
3248 
3249 	for_each_possible_cpu(cpu)
3250 		res += per_cpu_ptr(net->core.prot_inuse, cpu)->val[idx];
3251 
3252 	return res >= 0 ? res : 0;
3253 }
3254 EXPORT_SYMBOL_GPL(sock_prot_inuse_get);
3255 
3256 static void sock_inuse_add(struct net *net, int val)
3257 {
3258 	this_cpu_add(*net->core.sock_inuse, val);
3259 }
3260 
3261 int sock_inuse_get(struct net *net)
3262 {
3263 	int cpu, res = 0;
3264 
3265 	for_each_possible_cpu(cpu)
3266 		res += *per_cpu_ptr(net->core.sock_inuse, cpu);
3267 
3268 	return res;
3269 }
3270 
3271 EXPORT_SYMBOL_GPL(sock_inuse_get);
3272 
3273 static int __net_init sock_inuse_init_net(struct net *net)
3274 {
3275 	net->core.prot_inuse = alloc_percpu(struct prot_inuse);
3276 	if (net->core.prot_inuse == NULL)
3277 		return -ENOMEM;
3278 
3279 	net->core.sock_inuse = alloc_percpu(int);
3280 	if (net->core.sock_inuse == NULL)
3281 		goto out;
3282 
3283 	return 0;
3284 
3285 out:
3286 	free_percpu(net->core.prot_inuse);
3287 	return -ENOMEM;
3288 }
3289 
3290 static void __net_exit sock_inuse_exit_net(struct net *net)
3291 {
3292 	free_percpu(net->core.prot_inuse);
3293 	free_percpu(net->core.sock_inuse);
3294 }
3295 
3296 static struct pernet_operations net_inuse_ops = {
3297 	.init = sock_inuse_init_net,
3298 	.exit = sock_inuse_exit_net,
3299 };
3300 
3301 static __init int net_inuse_init(void)
3302 {
3303 	if (register_pernet_subsys(&net_inuse_ops))
3304 		panic("Cannot initialize net inuse counters");
3305 
3306 	return 0;
3307 }
3308 
3309 core_initcall(net_inuse_init);
3310 
3311 static int assign_proto_idx(struct proto *prot)
3312 {
3313 	prot->inuse_idx = find_first_zero_bit(proto_inuse_idx, PROTO_INUSE_NR);
3314 
3315 	if (unlikely(prot->inuse_idx == PROTO_INUSE_NR - 1)) {
3316 		pr_err("PROTO_INUSE_NR exhausted\n");
3317 		return -ENOSPC;
3318 	}
3319 
3320 	set_bit(prot->inuse_idx, proto_inuse_idx);
3321 	return 0;
3322 }
3323 
3324 static void release_proto_idx(struct proto *prot)
3325 {
3326 	if (prot->inuse_idx != PROTO_INUSE_NR - 1)
3327 		clear_bit(prot->inuse_idx, proto_inuse_idx);
3328 }
3329 #else
3330 static inline int assign_proto_idx(struct proto *prot)
3331 {
3332 	return 0;
3333 }
3334 
3335 static inline void release_proto_idx(struct proto *prot)
3336 {
3337 }
3338 
3339 static void sock_inuse_add(struct net *net, int val)
3340 {
3341 }
3342 #endif
3343 
3344 static void req_prot_cleanup(struct request_sock_ops *rsk_prot)
3345 {
3346 	if (!rsk_prot)
3347 		return;
3348 	kfree(rsk_prot->slab_name);
3349 	rsk_prot->slab_name = NULL;
3350 	kmem_cache_destroy(rsk_prot->slab);
3351 	rsk_prot->slab = NULL;
3352 }
3353 
3354 static int req_prot_init(const struct proto *prot)
3355 {
3356 	struct request_sock_ops *rsk_prot = prot->rsk_prot;
3357 
3358 	if (!rsk_prot)
3359 		return 0;
3360 
3361 	rsk_prot->slab_name = kasprintf(GFP_KERNEL, "request_sock_%s",
3362 					prot->name);
3363 	if (!rsk_prot->slab_name)
3364 		return -ENOMEM;
3365 
3366 	rsk_prot->slab = kmem_cache_create(rsk_prot->slab_name,
3367 					   rsk_prot->obj_size, 0,
3368 					   SLAB_ACCOUNT | prot->slab_flags,
3369 					   NULL);
3370 
3371 	if (!rsk_prot->slab) {
3372 		pr_crit("%s: Can't create request sock SLAB cache!\n",
3373 			prot->name);
3374 		return -ENOMEM;
3375 	}
3376 	return 0;
3377 }
3378 
3379 int proto_register(struct proto *prot, int alloc_slab)
3380 {
3381 	int ret = -ENOBUFS;
3382 
3383 	if (alloc_slab) {
3384 		prot->slab = kmem_cache_create_usercopy(prot->name,
3385 					prot->obj_size, 0,
3386 					SLAB_HWCACHE_ALIGN | SLAB_ACCOUNT |
3387 					prot->slab_flags,
3388 					prot->useroffset, prot->usersize,
3389 					NULL);
3390 
3391 		if (prot->slab == NULL) {
3392 			pr_crit("%s: Can't create sock SLAB cache!\n",
3393 				prot->name);
3394 			goto out;
3395 		}
3396 
3397 		if (req_prot_init(prot))
3398 			goto out_free_request_sock_slab;
3399 
3400 		if (prot->twsk_prot != NULL) {
3401 			prot->twsk_prot->twsk_slab_name = kasprintf(GFP_KERNEL, "tw_sock_%s", prot->name);
3402 
3403 			if (prot->twsk_prot->twsk_slab_name == NULL)
3404 				goto out_free_request_sock_slab;
3405 
3406 			prot->twsk_prot->twsk_slab =
3407 				kmem_cache_create(prot->twsk_prot->twsk_slab_name,
3408 						  prot->twsk_prot->twsk_obj_size,
3409 						  0,
3410 						  SLAB_ACCOUNT |
3411 						  prot->slab_flags,
3412 						  NULL);
3413 			if (prot->twsk_prot->twsk_slab == NULL)
3414 				goto out_free_timewait_sock_slab_name;
3415 		}
3416 	}
3417 
3418 	mutex_lock(&proto_list_mutex);
3419 	ret = assign_proto_idx(prot);
3420 	if (ret) {
3421 		mutex_unlock(&proto_list_mutex);
3422 		goto out_free_timewait_sock_slab_name;
3423 	}
3424 	list_add(&prot->node, &proto_list);
3425 	mutex_unlock(&proto_list_mutex);
3426 	return ret;
3427 
3428 out_free_timewait_sock_slab_name:
3429 	if (alloc_slab && prot->twsk_prot)
3430 		kfree(prot->twsk_prot->twsk_slab_name);
3431 out_free_request_sock_slab:
3432 	if (alloc_slab) {
3433 		req_prot_cleanup(prot->rsk_prot);
3434 
3435 		kmem_cache_destroy(prot->slab);
3436 		prot->slab = NULL;
3437 	}
3438 out:
3439 	return ret;
3440 }
3441 EXPORT_SYMBOL(proto_register);
3442 
3443 void proto_unregister(struct proto *prot)
3444 {
3445 	mutex_lock(&proto_list_mutex);
3446 	release_proto_idx(prot);
3447 	list_del(&prot->node);
3448 	mutex_unlock(&proto_list_mutex);
3449 
3450 	kmem_cache_destroy(prot->slab);
3451 	prot->slab = NULL;
3452 
3453 	req_prot_cleanup(prot->rsk_prot);
3454 
3455 	if (prot->twsk_prot != NULL && prot->twsk_prot->twsk_slab != NULL) {
3456 		kmem_cache_destroy(prot->twsk_prot->twsk_slab);
3457 		kfree(prot->twsk_prot->twsk_slab_name);
3458 		prot->twsk_prot->twsk_slab = NULL;
3459 	}
3460 }
3461 EXPORT_SYMBOL(proto_unregister);
3462 
3463 int sock_load_diag_module(int family, int protocol)
3464 {
3465 	if (!protocol) {
3466 		if (!sock_is_registered(family))
3467 			return -ENOENT;
3468 
3469 		return request_module("net-pf-%d-proto-%d-type-%d", PF_NETLINK,
3470 				      NETLINK_SOCK_DIAG, family);
3471 	}
3472 
3473 #ifdef CONFIG_INET
3474 	if (family == AF_INET &&
3475 	    protocol != IPPROTO_RAW &&
3476 	    !rcu_access_pointer(inet_protos[protocol]))
3477 		return -ENOENT;
3478 #endif
3479 
3480 	return request_module("net-pf-%d-proto-%d-type-%d-%d", PF_NETLINK,
3481 			      NETLINK_SOCK_DIAG, family, protocol);
3482 }
3483 EXPORT_SYMBOL(sock_load_diag_module);
3484 
3485 #ifdef CONFIG_PROC_FS
3486 static void *proto_seq_start(struct seq_file *seq, loff_t *pos)
3487 	__acquires(proto_list_mutex)
3488 {
3489 	mutex_lock(&proto_list_mutex);
3490 	return seq_list_start_head(&proto_list, *pos);
3491 }
3492 
3493 static void *proto_seq_next(struct seq_file *seq, void *v, loff_t *pos)
3494 {
3495 	return seq_list_next(v, &proto_list, pos);
3496 }
3497 
3498 static void proto_seq_stop(struct seq_file *seq, void *v)
3499 	__releases(proto_list_mutex)
3500 {
3501 	mutex_unlock(&proto_list_mutex);
3502 }
3503 
3504 static char proto_method_implemented(const void *method)
3505 {
3506 	return method == NULL ? 'n' : 'y';
3507 }
3508 static long sock_prot_memory_allocated(struct proto *proto)
3509 {
3510 	return proto->memory_allocated != NULL ? proto_memory_allocated(proto) : -1L;
3511 }
3512 
3513 static const char *sock_prot_memory_pressure(struct proto *proto)
3514 {
3515 	return proto->memory_pressure != NULL ?
3516 	proto_memory_pressure(proto) ? "yes" : "no" : "NI";
3517 }
3518 
3519 static void proto_seq_printf(struct seq_file *seq, struct proto *proto)
3520 {
3521 
3522 	seq_printf(seq, "%-9s %4u %6d  %6ld   %-3s %6u   %-3s  %-10s "
3523 			"%2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c\n",
3524 		   proto->name,
3525 		   proto->obj_size,
3526 		   sock_prot_inuse_get(seq_file_net(seq), proto),
3527 		   sock_prot_memory_allocated(proto),
3528 		   sock_prot_memory_pressure(proto),
3529 		   proto->max_header,
3530 		   proto->slab == NULL ? "no" : "yes",
3531 		   module_name(proto->owner),
3532 		   proto_method_implemented(proto->close),
3533 		   proto_method_implemented(proto->connect),
3534 		   proto_method_implemented(proto->disconnect),
3535 		   proto_method_implemented(proto->accept),
3536 		   proto_method_implemented(proto->ioctl),
3537 		   proto_method_implemented(proto->init),
3538 		   proto_method_implemented(proto->destroy),
3539 		   proto_method_implemented(proto->shutdown),
3540 		   proto_method_implemented(proto->setsockopt),
3541 		   proto_method_implemented(proto->getsockopt),
3542 		   proto_method_implemented(proto->sendmsg),
3543 		   proto_method_implemented(proto->recvmsg),
3544 		   proto_method_implemented(proto->sendpage),
3545 		   proto_method_implemented(proto->bind),
3546 		   proto_method_implemented(proto->backlog_rcv),
3547 		   proto_method_implemented(proto->hash),
3548 		   proto_method_implemented(proto->unhash),
3549 		   proto_method_implemented(proto->get_port),
3550 		   proto_method_implemented(proto->enter_memory_pressure));
3551 }
3552 
3553 static int proto_seq_show(struct seq_file *seq, void *v)
3554 {
3555 	if (v == &proto_list)
3556 		seq_printf(seq, "%-9s %-4s %-8s %-6s %-5s %-7s %-4s %-10s %s",
3557 			   "protocol",
3558 			   "size",
3559 			   "sockets",
3560 			   "memory",
3561 			   "press",
3562 			   "maxhdr",
3563 			   "slab",
3564 			   "module",
3565 			   "cl co di ac io in de sh ss gs se re sp bi br ha uh gp em\n");
3566 	else
3567 		proto_seq_printf(seq, list_entry(v, struct proto, node));
3568 	return 0;
3569 }
3570 
3571 static const struct seq_operations proto_seq_ops = {
3572 	.start  = proto_seq_start,
3573 	.next   = proto_seq_next,
3574 	.stop   = proto_seq_stop,
3575 	.show   = proto_seq_show,
3576 };
3577 
3578 static __net_init int proto_init_net(struct net *net)
3579 {
3580 	if (!proc_create_net("protocols", 0444, net->proc_net, &proto_seq_ops,
3581 			sizeof(struct seq_net_private)))
3582 		return -ENOMEM;
3583 
3584 	return 0;
3585 }
3586 
3587 static __net_exit void proto_exit_net(struct net *net)
3588 {
3589 	remove_proc_entry("protocols", net->proc_net);
3590 }
3591 
3592 
3593 static __net_initdata struct pernet_operations proto_net_ops = {
3594 	.init = proto_init_net,
3595 	.exit = proto_exit_net,
3596 };
3597 
3598 static int __init proto_init(void)
3599 {
3600 	return register_pernet_subsys(&proto_net_ops);
3601 }
3602 
3603 subsys_initcall(proto_init);
3604 
3605 #endif /* PROC_FS */
3606 
3607 #ifdef CONFIG_NET_RX_BUSY_POLL
3608 bool sk_busy_loop_end(void *p, unsigned long start_time)
3609 {
3610 	struct sock *sk = p;
3611 
3612 	return !skb_queue_empty_lockless(&sk->sk_receive_queue) ||
3613 	       sk_busy_loop_timeout(sk, start_time);
3614 }
3615 EXPORT_SYMBOL(sk_busy_loop_end);
3616 #endif /* CONFIG_NET_RX_BUSY_POLL */
3617