xref: /openbmc/linux/net/core/sock.c (revision 19758688)
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/udp.h>
111 #include <linux/init.h>
112 #include <linux/highmem.h>
113 #include <linux/user_namespace.h>
114 #include <linux/static_key.h>
115 #include <linux/memcontrol.h>
116 #include <linux/prefetch.h>
117 #include <linux/compat.h>
118 #include <linux/mroute.h>
119 #include <linux/mroute6.h>
120 #include <linux/icmpv6.h>
121 
122 #include <linux/uaccess.h>
123 
124 #include <linux/netdevice.h>
125 #include <net/protocol.h>
126 #include <linux/skbuff.h>
127 #include <net/net_namespace.h>
128 #include <net/request_sock.h>
129 #include <net/sock.h>
130 #include <linux/net_tstamp.h>
131 #include <net/xfrm.h>
132 #include <linux/ipsec.h>
133 #include <net/cls_cgroup.h>
134 #include <net/netprio_cgroup.h>
135 #include <linux/sock_diag.h>
136 
137 #include <linux/filter.h>
138 #include <net/sock_reuseport.h>
139 #include <net/bpf_sk_storage.h>
140 
141 #include <trace/events/sock.h>
142 
143 #include <net/tcp.h>
144 #include <net/busy_poll.h>
145 #include <net/phonet/phonet.h>
146 
147 #include <linux/ethtool.h>
148 
149 #include "dev.h"
150 
151 static DEFINE_MUTEX(proto_list_mutex);
152 static LIST_HEAD(proto_list);
153 
154 static void sock_def_write_space_wfree(struct sock *sk);
155 static void sock_def_write_space(struct sock *sk);
156 
157 /**
158  * sk_ns_capable - General socket capability test
159  * @sk: Socket to use a capability on or through
160  * @user_ns: The user namespace of the capability to use
161  * @cap: The capability to use
162  *
163  * Test to see if the opener of the socket had when the socket was
164  * created and the current process has the capability @cap in the user
165  * namespace @user_ns.
166  */
167 bool sk_ns_capable(const struct sock *sk,
168 		   struct user_namespace *user_ns, int cap)
169 {
170 	return file_ns_capable(sk->sk_socket->file, user_ns, cap) &&
171 		ns_capable(user_ns, cap);
172 }
173 EXPORT_SYMBOL(sk_ns_capable);
174 
175 /**
176  * sk_capable - Socket global capability test
177  * @sk: Socket to use a capability on or through
178  * @cap: The global capability to use
179  *
180  * Test to see if the opener of the socket had when the socket was
181  * created and the current process has the capability @cap in all user
182  * namespaces.
183  */
184 bool sk_capable(const struct sock *sk, int cap)
185 {
186 	return sk_ns_capable(sk, &init_user_ns, cap);
187 }
188 EXPORT_SYMBOL(sk_capable);
189 
190 /**
191  * sk_net_capable - Network namespace socket capability test
192  * @sk: Socket to use a capability on or through
193  * @cap: The capability to use
194  *
195  * Test to see if the opener of the socket had when the socket was created
196  * and the current process has the capability @cap over the network namespace
197  * the socket is a member of.
198  */
199 bool sk_net_capable(const struct sock *sk, int cap)
200 {
201 	return sk_ns_capable(sk, sock_net(sk)->user_ns, cap);
202 }
203 EXPORT_SYMBOL(sk_net_capable);
204 
205 /*
206  * Each address family might have different locking rules, so we have
207  * one slock key per address family and separate keys for internal and
208  * userspace sockets.
209  */
210 static struct lock_class_key af_family_keys[AF_MAX];
211 static struct lock_class_key af_family_kern_keys[AF_MAX];
212 static struct lock_class_key af_family_slock_keys[AF_MAX];
213 static struct lock_class_key af_family_kern_slock_keys[AF_MAX];
214 
215 /*
216  * Make lock validator output more readable. (we pre-construct these
217  * strings build-time, so that runtime initialization of socket
218  * locks is fast):
219  */
220 
221 #define _sock_locks(x)						  \
222   x "AF_UNSPEC",	x "AF_UNIX"     ,	x "AF_INET"     , \
223   x "AF_AX25"  ,	x "AF_IPX"      ,	x "AF_APPLETALK", \
224   x "AF_NETROM",	x "AF_BRIDGE"   ,	x "AF_ATMPVC"   , \
225   x "AF_X25"   ,	x "AF_INET6"    ,	x "AF_ROSE"     , \
226   x "AF_DECnet",	x "AF_NETBEUI"  ,	x "AF_SECURITY" , \
227   x "AF_KEY"   ,	x "AF_NETLINK"  ,	x "AF_PACKET"   , \
228   x "AF_ASH"   ,	x "AF_ECONET"   ,	x "AF_ATMSVC"   , \
229   x "AF_RDS"   ,	x "AF_SNA"      ,	x "AF_IRDA"     , \
230   x "AF_PPPOX" ,	x "AF_WANPIPE"  ,	x "AF_LLC"      , \
231   x "27"       ,	x "28"          ,	x "AF_CAN"      , \
232   x "AF_TIPC"  ,	x "AF_BLUETOOTH",	x "IUCV"        , \
233   x "AF_RXRPC" ,	x "AF_ISDN"     ,	x "AF_PHONET"   , \
234   x "AF_IEEE802154",	x "AF_CAIF"	,	x "AF_ALG"      , \
235   x "AF_NFC"   ,	x "AF_VSOCK"    ,	x "AF_KCM"      , \
236   x "AF_QIPCRTR",	x "AF_SMC"	,	x "AF_XDP"	, \
237   x "AF_MCTP"  , \
238   x "AF_MAX"
239 
240 static const char *const af_family_key_strings[AF_MAX+1] = {
241 	_sock_locks("sk_lock-")
242 };
243 static const char *const af_family_slock_key_strings[AF_MAX+1] = {
244 	_sock_locks("slock-")
245 };
246 static const char *const af_family_clock_key_strings[AF_MAX+1] = {
247 	_sock_locks("clock-")
248 };
249 
250 static const char *const af_family_kern_key_strings[AF_MAX+1] = {
251 	_sock_locks("k-sk_lock-")
252 };
253 static const char *const af_family_kern_slock_key_strings[AF_MAX+1] = {
254 	_sock_locks("k-slock-")
255 };
256 static const char *const af_family_kern_clock_key_strings[AF_MAX+1] = {
257 	_sock_locks("k-clock-")
258 };
259 static const char *const af_family_rlock_key_strings[AF_MAX+1] = {
260 	_sock_locks("rlock-")
261 };
262 static const char *const af_family_wlock_key_strings[AF_MAX+1] = {
263 	_sock_locks("wlock-")
264 };
265 static const char *const af_family_elock_key_strings[AF_MAX+1] = {
266 	_sock_locks("elock-")
267 };
268 
269 /*
270  * sk_callback_lock and sk queues locking rules are per-address-family,
271  * so split the lock classes by using a per-AF key:
272  */
273 static struct lock_class_key af_callback_keys[AF_MAX];
274 static struct lock_class_key af_rlock_keys[AF_MAX];
275 static struct lock_class_key af_wlock_keys[AF_MAX];
276 static struct lock_class_key af_elock_keys[AF_MAX];
277 static struct lock_class_key af_kern_callback_keys[AF_MAX];
278 
279 /* Run time adjustable parameters. */
280 __u32 sysctl_wmem_max __read_mostly = SK_WMEM_MAX;
281 EXPORT_SYMBOL(sysctl_wmem_max);
282 __u32 sysctl_rmem_max __read_mostly = SK_RMEM_MAX;
283 EXPORT_SYMBOL(sysctl_rmem_max);
284 __u32 sysctl_wmem_default __read_mostly = SK_WMEM_MAX;
285 __u32 sysctl_rmem_default __read_mostly = SK_RMEM_MAX;
286 
287 /* Maximal space eaten by iovec or ancillary data plus some space */
288 int sysctl_optmem_max __read_mostly = sizeof(unsigned long)*(2*UIO_MAXIOV+512);
289 EXPORT_SYMBOL(sysctl_optmem_max);
290 
291 int sysctl_tstamp_allow_data __read_mostly = 1;
292 
293 DEFINE_STATIC_KEY_FALSE(memalloc_socks_key);
294 EXPORT_SYMBOL_GPL(memalloc_socks_key);
295 
296 /**
297  * sk_set_memalloc - sets %SOCK_MEMALLOC
298  * @sk: socket to set it on
299  *
300  * Set %SOCK_MEMALLOC on a socket for access to emergency reserves.
301  * It's the responsibility of the admin to adjust min_free_kbytes
302  * to meet the requirements
303  */
304 void sk_set_memalloc(struct sock *sk)
305 {
306 	sock_set_flag(sk, SOCK_MEMALLOC);
307 	sk->sk_allocation |= __GFP_MEMALLOC;
308 	static_branch_inc(&memalloc_socks_key);
309 }
310 EXPORT_SYMBOL_GPL(sk_set_memalloc);
311 
312 void sk_clear_memalloc(struct sock *sk)
313 {
314 	sock_reset_flag(sk, SOCK_MEMALLOC);
315 	sk->sk_allocation &= ~__GFP_MEMALLOC;
316 	static_branch_dec(&memalloc_socks_key);
317 
318 	/*
319 	 * SOCK_MEMALLOC is allowed to ignore rmem limits to ensure forward
320 	 * progress of swapping. SOCK_MEMALLOC may be cleared while
321 	 * it has rmem allocations due to the last swapfile being deactivated
322 	 * but there is a risk that the socket is unusable due to exceeding
323 	 * the rmem limits. Reclaim the reserves and obey rmem limits again.
324 	 */
325 	sk_mem_reclaim(sk);
326 }
327 EXPORT_SYMBOL_GPL(sk_clear_memalloc);
328 
329 int __sk_backlog_rcv(struct sock *sk, struct sk_buff *skb)
330 {
331 	int ret;
332 	unsigned int noreclaim_flag;
333 
334 	/* these should have been dropped before queueing */
335 	BUG_ON(!sock_flag(sk, SOCK_MEMALLOC));
336 
337 	noreclaim_flag = memalloc_noreclaim_save();
338 	ret = INDIRECT_CALL_INET(sk->sk_backlog_rcv,
339 				 tcp_v6_do_rcv,
340 				 tcp_v4_do_rcv,
341 				 sk, skb);
342 	memalloc_noreclaim_restore(noreclaim_flag);
343 
344 	return ret;
345 }
346 EXPORT_SYMBOL(__sk_backlog_rcv);
347 
348 void sk_error_report(struct sock *sk)
349 {
350 	sk->sk_error_report(sk);
351 
352 	switch (sk->sk_family) {
353 	case AF_INET:
354 		fallthrough;
355 	case AF_INET6:
356 		trace_inet_sk_error_report(sk);
357 		break;
358 	default:
359 		break;
360 	}
361 }
362 EXPORT_SYMBOL(sk_error_report);
363 
364 int sock_get_timeout(long timeo, void *optval, bool old_timeval)
365 {
366 	struct __kernel_sock_timeval tv;
367 
368 	if (timeo == MAX_SCHEDULE_TIMEOUT) {
369 		tv.tv_sec = 0;
370 		tv.tv_usec = 0;
371 	} else {
372 		tv.tv_sec = timeo / HZ;
373 		tv.tv_usec = ((timeo % HZ) * USEC_PER_SEC) / HZ;
374 	}
375 
376 	if (old_timeval && in_compat_syscall() && !COMPAT_USE_64BIT_TIME) {
377 		struct old_timeval32 tv32 = { tv.tv_sec, tv.tv_usec };
378 		*(struct old_timeval32 *)optval = tv32;
379 		return sizeof(tv32);
380 	}
381 
382 	if (old_timeval) {
383 		struct __kernel_old_timeval old_tv;
384 		old_tv.tv_sec = tv.tv_sec;
385 		old_tv.tv_usec = tv.tv_usec;
386 		*(struct __kernel_old_timeval *)optval = old_tv;
387 		return sizeof(old_tv);
388 	}
389 
390 	*(struct __kernel_sock_timeval *)optval = tv;
391 	return sizeof(tv);
392 }
393 EXPORT_SYMBOL(sock_get_timeout);
394 
395 int sock_copy_user_timeval(struct __kernel_sock_timeval *tv,
396 			   sockptr_t optval, int optlen, bool old_timeval)
397 {
398 	if (old_timeval && in_compat_syscall() && !COMPAT_USE_64BIT_TIME) {
399 		struct old_timeval32 tv32;
400 
401 		if (optlen < sizeof(tv32))
402 			return -EINVAL;
403 
404 		if (copy_from_sockptr(&tv32, optval, sizeof(tv32)))
405 			return -EFAULT;
406 		tv->tv_sec = tv32.tv_sec;
407 		tv->tv_usec = tv32.tv_usec;
408 	} else if (old_timeval) {
409 		struct __kernel_old_timeval old_tv;
410 
411 		if (optlen < sizeof(old_tv))
412 			return -EINVAL;
413 		if (copy_from_sockptr(&old_tv, optval, sizeof(old_tv)))
414 			return -EFAULT;
415 		tv->tv_sec = old_tv.tv_sec;
416 		tv->tv_usec = old_tv.tv_usec;
417 	} else {
418 		if (optlen < sizeof(*tv))
419 			return -EINVAL;
420 		if (copy_from_sockptr(tv, optval, sizeof(*tv)))
421 			return -EFAULT;
422 	}
423 
424 	return 0;
425 }
426 EXPORT_SYMBOL(sock_copy_user_timeval);
427 
428 static int sock_set_timeout(long *timeo_p, sockptr_t optval, int optlen,
429 			    bool old_timeval)
430 {
431 	struct __kernel_sock_timeval tv;
432 	int err = sock_copy_user_timeval(&tv, optval, optlen, old_timeval);
433 	long val;
434 
435 	if (err)
436 		return err;
437 
438 	if (tv.tv_usec < 0 || tv.tv_usec >= USEC_PER_SEC)
439 		return -EDOM;
440 
441 	if (tv.tv_sec < 0) {
442 		static int warned __read_mostly;
443 
444 		WRITE_ONCE(*timeo_p, 0);
445 		if (warned < 10 && net_ratelimit()) {
446 			warned++;
447 			pr_info("%s: `%s' (pid %d) tries to set negative timeout\n",
448 				__func__, current->comm, task_pid_nr(current));
449 		}
450 		return 0;
451 	}
452 	val = MAX_SCHEDULE_TIMEOUT;
453 	if ((tv.tv_sec || tv.tv_usec) &&
454 	    (tv.tv_sec < (MAX_SCHEDULE_TIMEOUT / HZ - 1)))
455 		val = tv.tv_sec * HZ + DIV_ROUND_UP((unsigned long)tv.tv_usec,
456 						    USEC_PER_SEC / HZ);
457 	WRITE_ONCE(*timeo_p, val);
458 	return 0;
459 }
460 
461 static bool sock_needs_netstamp(const struct sock *sk)
462 {
463 	switch (sk->sk_family) {
464 	case AF_UNSPEC:
465 	case AF_UNIX:
466 		return false;
467 	default:
468 		return true;
469 	}
470 }
471 
472 static void sock_disable_timestamp(struct sock *sk, unsigned long flags)
473 {
474 	if (sk->sk_flags & flags) {
475 		sk->sk_flags &= ~flags;
476 		if (sock_needs_netstamp(sk) &&
477 		    !(sk->sk_flags & SK_FLAGS_TIMESTAMP))
478 			net_disable_timestamp();
479 	}
480 }
481 
482 
483 int __sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
484 {
485 	unsigned long flags;
486 	struct sk_buff_head *list = &sk->sk_receive_queue;
487 
488 	if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf) {
489 		atomic_inc(&sk->sk_drops);
490 		trace_sock_rcvqueue_full(sk, skb);
491 		return -ENOMEM;
492 	}
493 
494 	if (!sk_rmem_schedule(sk, skb, skb->truesize)) {
495 		atomic_inc(&sk->sk_drops);
496 		return -ENOBUFS;
497 	}
498 
499 	skb->dev = NULL;
500 	skb_set_owner_r(skb, sk);
501 
502 	/* we escape from rcu protected region, make sure we dont leak
503 	 * a norefcounted dst
504 	 */
505 	skb_dst_force(skb);
506 
507 	spin_lock_irqsave(&list->lock, flags);
508 	sock_skb_set_dropcount(sk, skb);
509 	__skb_queue_tail(list, skb);
510 	spin_unlock_irqrestore(&list->lock, flags);
511 
512 	if (!sock_flag(sk, SOCK_DEAD))
513 		sk->sk_data_ready(sk);
514 	return 0;
515 }
516 EXPORT_SYMBOL(__sock_queue_rcv_skb);
517 
518 int sock_queue_rcv_skb_reason(struct sock *sk, struct sk_buff *skb,
519 			      enum skb_drop_reason *reason)
520 {
521 	enum skb_drop_reason drop_reason;
522 	int err;
523 
524 	err = sk_filter(sk, skb);
525 	if (err) {
526 		drop_reason = SKB_DROP_REASON_SOCKET_FILTER;
527 		goto out;
528 	}
529 	err = __sock_queue_rcv_skb(sk, skb);
530 	switch (err) {
531 	case -ENOMEM:
532 		drop_reason = SKB_DROP_REASON_SOCKET_RCVBUFF;
533 		break;
534 	case -ENOBUFS:
535 		drop_reason = SKB_DROP_REASON_PROTO_MEM;
536 		break;
537 	default:
538 		drop_reason = SKB_NOT_DROPPED_YET;
539 		break;
540 	}
541 out:
542 	if (reason)
543 		*reason = drop_reason;
544 	return err;
545 }
546 EXPORT_SYMBOL(sock_queue_rcv_skb_reason);
547 
548 int __sk_receive_skb(struct sock *sk, struct sk_buff *skb,
549 		     const int nested, unsigned int trim_cap, bool refcounted)
550 {
551 	int rc = NET_RX_SUCCESS;
552 
553 	if (sk_filter_trim_cap(sk, skb, trim_cap))
554 		goto discard_and_relse;
555 
556 	skb->dev = NULL;
557 
558 	if (sk_rcvqueues_full(sk, sk->sk_rcvbuf)) {
559 		atomic_inc(&sk->sk_drops);
560 		goto discard_and_relse;
561 	}
562 	if (nested)
563 		bh_lock_sock_nested(sk);
564 	else
565 		bh_lock_sock(sk);
566 	if (!sock_owned_by_user(sk)) {
567 		/*
568 		 * trylock + unlock semantics:
569 		 */
570 		mutex_acquire(&sk->sk_lock.dep_map, 0, 1, _RET_IP_);
571 
572 		rc = sk_backlog_rcv(sk, skb);
573 
574 		mutex_release(&sk->sk_lock.dep_map, _RET_IP_);
575 	} else if (sk_add_backlog(sk, skb, READ_ONCE(sk->sk_rcvbuf))) {
576 		bh_unlock_sock(sk);
577 		atomic_inc(&sk->sk_drops);
578 		goto discard_and_relse;
579 	}
580 
581 	bh_unlock_sock(sk);
582 out:
583 	if (refcounted)
584 		sock_put(sk);
585 	return rc;
586 discard_and_relse:
587 	kfree_skb(skb);
588 	goto out;
589 }
590 EXPORT_SYMBOL(__sk_receive_skb);
591 
592 INDIRECT_CALLABLE_DECLARE(struct dst_entry *ip6_dst_check(struct dst_entry *,
593 							  u32));
594 INDIRECT_CALLABLE_DECLARE(struct dst_entry *ipv4_dst_check(struct dst_entry *,
595 							   u32));
596 struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie)
597 {
598 	struct dst_entry *dst = __sk_dst_get(sk);
599 
600 	if (dst && dst->obsolete &&
601 	    INDIRECT_CALL_INET(dst->ops->check, ip6_dst_check, ipv4_dst_check,
602 			       dst, cookie) == NULL) {
603 		sk_tx_queue_clear(sk);
604 		WRITE_ONCE(sk->sk_dst_pending_confirm, 0);
605 		RCU_INIT_POINTER(sk->sk_dst_cache, NULL);
606 		dst_release(dst);
607 		return NULL;
608 	}
609 
610 	return dst;
611 }
612 EXPORT_SYMBOL(__sk_dst_check);
613 
614 struct dst_entry *sk_dst_check(struct sock *sk, u32 cookie)
615 {
616 	struct dst_entry *dst = sk_dst_get(sk);
617 
618 	if (dst && dst->obsolete &&
619 	    INDIRECT_CALL_INET(dst->ops->check, ip6_dst_check, ipv4_dst_check,
620 			       dst, cookie) == NULL) {
621 		sk_dst_reset(sk);
622 		dst_release(dst);
623 		return NULL;
624 	}
625 
626 	return dst;
627 }
628 EXPORT_SYMBOL(sk_dst_check);
629 
630 static int sock_bindtoindex_locked(struct sock *sk, int ifindex)
631 {
632 	int ret = -ENOPROTOOPT;
633 #ifdef CONFIG_NETDEVICES
634 	struct net *net = sock_net(sk);
635 
636 	/* Sorry... */
637 	ret = -EPERM;
638 	if (sk->sk_bound_dev_if && !ns_capable(net->user_ns, CAP_NET_RAW))
639 		goto out;
640 
641 	ret = -EINVAL;
642 	if (ifindex < 0)
643 		goto out;
644 
645 	/* Paired with all READ_ONCE() done locklessly. */
646 	WRITE_ONCE(sk->sk_bound_dev_if, ifindex);
647 
648 	if (sk->sk_prot->rehash)
649 		sk->sk_prot->rehash(sk);
650 	sk_dst_reset(sk);
651 
652 	ret = 0;
653 
654 out:
655 #endif
656 
657 	return ret;
658 }
659 
660 int sock_bindtoindex(struct sock *sk, int ifindex, bool lock_sk)
661 {
662 	int ret;
663 
664 	if (lock_sk)
665 		lock_sock(sk);
666 	ret = sock_bindtoindex_locked(sk, ifindex);
667 	if (lock_sk)
668 		release_sock(sk);
669 
670 	return ret;
671 }
672 EXPORT_SYMBOL(sock_bindtoindex);
673 
674 static int sock_setbindtodevice(struct sock *sk, sockptr_t optval, int optlen)
675 {
676 	int ret = -ENOPROTOOPT;
677 #ifdef CONFIG_NETDEVICES
678 	struct net *net = sock_net(sk);
679 	char devname[IFNAMSIZ];
680 	int index;
681 
682 	ret = -EINVAL;
683 	if (optlen < 0)
684 		goto out;
685 
686 	/* Bind this socket to a particular device like "eth0",
687 	 * as specified in the passed interface name. If the
688 	 * name is "" or the option length is zero the socket
689 	 * is not bound.
690 	 */
691 	if (optlen > IFNAMSIZ - 1)
692 		optlen = IFNAMSIZ - 1;
693 	memset(devname, 0, sizeof(devname));
694 
695 	ret = -EFAULT;
696 	if (copy_from_sockptr(devname, optval, optlen))
697 		goto out;
698 
699 	index = 0;
700 	if (devname[0] != '\0') {
701 		struct net_device *dev;
702 
703 		rcu_read_lock();
704 		dev = dev_get_by_name_rcu(net, devname);
705 		if (dev)
706 			index = dev->ifindex;
707 		rcu_read_unlock();
708 		ret = -ENODEV;
709 		if (!dev)
710 			goto out;
711 	}
712 
713 	sockopt_lock_sock(sk);
714 	ret = sock_bindtoindex_locked(sk, index);
715 	sockopt_release_sock(sk);
716 out:
717 #endif
718 
719 	return ret;
720 }
721 
722 static int sock_getbindtodevice(struct sock *sk, sockptr_t optval,
723 				sockptr_t optlen, int len)
724 {
725 	int ret = -ENOPROTOOPT;
726 #ifdef CONFIG_NETDEVICES
727 	int bound_dev_if = READ_ONCE(sk->sk_bound_dev_if);
728 	struct net *net = sock_net(sk);
729 	char devname[IFNAMSIZ];
730 
731 	if (bound_dev_if == 0) {
732 		len = 0;
733 		goto zero;
734 	}
735 
736 	ret = -EINVAL;
737 	if (len < IFNAMSIZ)
738 		goto out;
739 
740 	ret = netdev_get_name(net, devname, bound_dev_if);
741 	if (ret)
742 		goto out;
743 
744 	len = strlen(devname) + 1;
745 
746 	ret = -EFAULT;
747 	if (copy_to_sockptr(optval, devname, len))
748 		goto out;
749 
750 zero:
751 	ret = -EFAULT;
752 	if (copy_to_sockptr(optlen, &len, sizeof(int)))
753 		goto out;
754 
755 	ret = 0;
756 
757 out:
758 #endif
759 
760 	return ret;
761 }
762 
763 bool sk_mc_loop(struct sock *sk)
764 {
765 	if (dev_recursion_level())
766 		return false;
767 	if (!sk)
768 		return true;
769 	/* IPV6_ADDRFORM can change sk->sk_family under us. */
770 	switch (READ_ONCE(sk->sk_family)) {
771 	case AF_INET:
772 		return inet_test_bit(MC_LOOP, sk);
773 #if IS_ENABLED(CONFIG_IPV6)
774 	case AF_INET6:
775 		return inet6_sk(sk)->mc_loop;
776 #endif
777 	}
778 	WARN_ON_ONCE(1);
779 	return true;
780 }
781 EXPORT_SYMBOL(sk_mc_loop);
782 
783 void sock_set_reuseaddr(struct sock *sk)
784 {
785 	lock_sock(sk);
786 	sk->sk_reuse = SK_CAN_REUSE;
787 	release_sock(sk);
788 }
789 EXPORT_SYMBOL(sock_set_reuseaddr);
790 
791 void sock_set_reuseport(struct sock *sk)
792 {
793 	lock_sock(sk);
794 	sk->sk_reuseport = true;
795 	release_sock(sk);
796 }
797 EXPORT_SYMBOL(sock_set_reuseport);
798 
799 void sock_no_linger(struct sock *sk)
800 {
801 	lock_sock(sk);
802 	WRITE_ONCE(sk->sk_lingertime, 0);
803 	sock_set_flag(sk, SOCK_LINGER);
804 	release_sock(sk);
805 }
806 EXPORT_SYMBOL(sock_no_linger);
807 
808 void sock_set_priority(struct sock *sk, u32 priority)
809 {
810 	lock_sock(sk);
811 	WRITE_ONCE(sk->sk_priority, priority);
812 	release_sock(sk);
813 }
814 EXPORT_SYMBOL(sock_set_priority);
815 
816 void sock_set_sndtimeo(struct sock *sk, s64 secs)
817 {
818 	lock_sock(sk);
819 	if (secs && secs < MAX_SCHEDULE_TIMEOUT / HZ - 1)
820 		WRITE_ONCE(sk->sk_sndtimeo, secs * HZ);
821 	else
822 		WRITE_ONCE(sk->sk_sndtimeo, MAX_SCHEDULE_TIMEOUT);
823 	release_sock(sk);
824 }
825 EXPORT_SYMBOL(sock_set_sndtimeo);
826 
827 static void __sock_set_timestamps(struct sock *sk, bool val, bool new, bool ns)
828 {
829 	if (val)  {
830 		sock_valbool_flag(sk, SOCK_TSTAMP_NEW, new);
831 		sock_valbool_flag(sk, SOCK_RCVTSTAMPNS, ns);
832 		sock_set_flag(sk, SOCK_RCVTSTAMP);
833 		sock_enable_timestamp(sk, SOCK_TIMESTAMP);
834 	} else {
835 		sock_reset_flag(sk, SOCK_RCVTSTAMP);
836 		sock_reset_flag(sk, SOCK_RCVTSTAMPNS);
837 	}
838 }
839 
840 void sock_enable_timestamps(struct sock *sk)
841 {
842 	lock_sock(sk);
843 	__sock_set_timestamps(sk, true, false, true);
844 	release_sock(sk);
845 }
846 EXPORT_SYMBOL(sock_enable_timestamps);
847 
848 void sock_set_timestamp(struct sock *sk, int optname, bool valbool)
849 {
850 	switch (optname) {
851 	case SO_TIMESTAMP_OLD:
852 		__sock_set_timestamps(sk, valbool, false, false);
853 		break;
854 	case SO_TIMESTAMP_NEW:
855 		__sock_set_timestamps(sk, valbool, true, false);
856 		break;
857 	case SO_TIMESTAMPNS_OLD:
858 		__sock_set_timestamps(sk, valbool, false, true);
859 		break;
860 	case SO_TIMESTAMPNS_NEW:
861 		__sock_set_timestamps(sk, valbool, true, true);
862 		break;
863 	}
864 }
865 
866 static int sock_timestamping_bind_phc(struct sock *sk, int phc_index)
867 {
868 	struct net *net = sock_net(sk);
869 	struct net_device *dev = NULL;
870 	bool match = false;
871 	int *vclock_index;
872 	int i, num;
873 
874 	if (sk->sk_bound_dev_if)
875 		dev = dev_get_by_index(net, sk->sk_bound_dev_if);
876 
877 	if (!dev) {
878 		pr_err("%s: sock not bind to device\n", __func__);
879 		return -EOPNOTSUPP;
880 	}
881 
882 	num = ethtool_get_phc_vclocks(dev, &vclock_index);
883 	dev_put(dev);
884 
885 	for (i = 0; i < num; i++) {
886 		if (*(vclock_index + i) == phc_index) {
887 			match = true;
888 			break;
889 		}
890 	}
891 
892 	if (num > 0)
893 		kfree(vclock_index);
894 
895 	if (!match)
896 		return -EINVAL;
897 
898 	WRITE_ONCE(sk->sk_bind_phc, phc_index);
899 
900 	return 0;
901 }
902 
903 int sock_set_timestamping(struct sock *sk, int optname,
904 			  struct so_timestamping timestamping)
905 {
906 	int val = timestamping.flags;
907 	int ret;
908 
909 	if (val & ~SOF_TIMESTAMPING_MASK)
910 		return -EINVAL;
911 
912 	if (val & SOF_TIMESTAMPING_OPT_ID_TCP &&
913 	    !(val & SOF_TIMESTAMPING_OPT_ID))
914 		return -EINVAL;
915 
916 	if (val & SOF_TIMESTAMPING_OPT_ID &&
917 	    !(sk->sk_tsflags & SOF_TIMESTAMPING_OPT_ID)) {
918 		if (sk_is_tcp(sk)) {
919 			if ((1 << sk->sk_state) &
920 			    (TCPF_CLOSE | TCPF_LISTEN))
921 				return -EINVAL;
922 			if (val & SOF_TIMESTAMPING_OPT_ID_TCP)
923 				atomic_set(&sk->sk_tskey, tcp_sk(sk)->write_seq);
924 			else
925 				atomic_set(&sk->sk_tskey, tcp_sk(sk)->snd_una);
926 		} else {
927 			atomic_set(&sk->sk_tskey, 0);
928 		}
929 	}
930 
931 	if (val & SOF_TIMESTAMPING_OPT_STATS &&
932 	    !(val & SOF_TIMESTAMPING_OPT_TSONLY))
933 		return -EINVAL;
934 
935 	if (val & SOF_TIMESTAMPING_BIND_PHC) {
936 		ret = sock_timestamping_bind_phc(sk, timestamping.bind_phc);
937 		if (ret)
938 			return ret;
939 	}
940 
941 	WRITE_ONCE(sk->sk_tsflags, val);
942 	sock_valbool_flag(sk, SOCK_TSTAMP_NEW, optname == SO_TIMESTAMPING_NEW);
943 
944 	if (val & SOF_TIMESTAMPING_RX_SOFTWARE)
945 		sock_enable_timestamp(sk,
946 				      SOCK_TIMESTAMPING_RX_SOFTWARE);
947 	else
948 		sock_disable_timestamp(sk,
949 				       (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE));
950 	return 0;
951 }
952 
953 void sock_set_keepalive(struct sock *sk)
954 {
955 	lock_sock(sk);
956 	if (sk->sk_prot->keepalive)
957 		sk->sk_prot->keepalive(sk, true);
958 	sock_valbool_flag(sk, SOCK_KEEPOPEN, true);
959 	release_sock(sk);
960 }
961 EXPORT_SYMBOL(sock_set_keepalive);
962 
963 static void __sock_set_rcvbuf(struct sock *sk, int val)
964 {
965 	/* Ensure val * 2 fits into an int, to prevent max_t() from treating it
966 	 * as a negative value.
967 	 */
968 	val = min_t(int, val, INT_MAX / 2);
969 	sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
970 
971 	/* We double it on the way in to account for "struct sk_buff" etc.
972 	 * overhead.   Applications assume that the SO_RCVBUF setting they make
973 	 * will allow that much actual data to be received on that socket.
974 	 *
975 	 * Applications are unaware that "struct sk_buff" and other overheads
976 	 * allocate from the receive buffer during socket buffer allocation.
977 	 *
978 	 * And after considering the possible alternatives, returning the value
979 	 * we actually used in getsockopt is the most desirable behavior.
980 	 */
981 	WRITE_ONCE(sk->sk_rcvbuf, max_t(int, val * 2, SOCK_MIN_RCVBUF));
982 }
983 
984 void sock_set_rcvbuf(struct sock *sk, int val)
985 {
986 	lock_sock(sk);
987 	__sock_set_rcvbuf(sk, val);
988 	release_sock(sk);
989 }
990 EXPORT_SYMBOL(sock_set_rcvbuf);
991 
992 static void __sock_set_mark(struct sock *sk, u32 val)
993 {
994 	if (val != sk->sk_mark) {
995 		WRITE_ONCE(sk->sk_mark, val);
996 		sk_dst_reset(sk);
997 	}
998 }
999 
1000 void sock_set_mark(struct sock *sk, u32 val)
1001 {
1002 	lock_sock(sk);
1003 	__sock_set_mark(sk, val);
1004 	release_sock(sk);
1005 }
1006 EXPORT_SYMBOL(sock_set_mark);
1007 
1008 static void sock_release_reserved_memory(struct sock *sk, int bytes)
1009 {
1010 	/* Round down bytes to multiple of pages */
1011 	bytes = round_down(bytes, PAGE_SIZE);
1012 
1013 	WARN_ON(bytes > sk->sk_reserved_mem);
1014 	WRITE_ONCE(sk->sk_reserved_mem, sk->sk_reserved_mem - bytes);
1015 	sk_mem_reclaim(sk);
1016 }
1017 
1018 static int sock_reserve_memory(struct sock *sk, int bytes)
1019 {
1020 	long allocated;
1021 	bool charged;
1022 	int pages;
1023 
1024 	if (!mem_cgroup_sockets_enabled || !sk->sk_memcg || !sk_has_account(sk))
1025 		return -EOPNOTSUPP;
1026 
1027 	if (!bytes)
1028 		return 0;
1029 
1030 	pages = sk_mem_pages(bytes);
1031 
1032 	/* pre-charge to memcg */
1033 	charged = mem_cgroup_charge_skmem(sk->sk_memcg, pages,
1034 					  GFP_KERNEL | __GFP_RETRY_MAYFAIL);
1035 	if (!charged)
1036 		return -ENOMEM;
1037 
1038 	/* pre-charge to forward_alloc */
1039 	sk_memory_allocated_add(sk, pages);
1040 	allocated = sk_memory_allocated(sk);
1041 	/* If the system goes into memory pressure with this
1042 	 * precharge, give up and return error.
1043 	 */
1044 	if (allocated > sk_prot_mem_limits(sk, 1)) {
1045 		sk_memory_allocated_sub(sk, pages);
1046 		mem_cgroup_uncharge_skmem(sk->sk_memcg, pages);
1047 		return -ENOMEM;
1048 	}
1049 	sk_forward_alloc_add(sk, pages << PAGE_SHIFT);
1050 
1051 	WRITE_ONCE(sk->sk_reserved_mem,
1052 		   sk->sk_reserved_mem + (pages << PAGE_SHIFT));
1053 
1054 	return 0;
1055 }
1056 
1057 void sockopt_lock_sock(struct sock *sk)
1058 {
1059 	/* When current->bpf_ctx is set, the setsockopt is called from
1060 	 * a bpf prog.  bpf has ensured the sk lock has been
1061 	 * acquired before calling setsockopt().
1062 	 */
1063 	if (has_current_bpf_ctx())
1064 		return;
1065 
1066 	lock_sock(sk);
1067 }
1068 EXPORT_SYMBOL(sockopt_lock_sock);
1069 
1070 void sockopt_release_sock(struct sock *sk)
1071 {
1072 	if (has_current_bpf_ctx())
1073 		return;
1074 
1075 	release_sock(sk);
1076 }
1077 EXPORT_SYMBOL(sockopt_release_sock);
1078 
1079 bool sockopt_ns_capable(struct user_namespace *ns, int cap)
1080 {
1081 	return has_current_bpf_ctx() || ns_capable(ns, cap);
1082 }
1083 EXPORT_SYMBOL(sockopt_ns_capable);
1084 
1085 bool sockopt_capable(int cap)
1086 {
1087 	return has_current_bpf_ctx() || capable(cap);
1088 }
1089 EXPORT_SYMBOL(sockopt_capable);
1090 
1091 /*
1092  *	This is meant for all protocols to use and covers goings on
1093  *	at the socket level. Everything here is generic.
1094  */
1095 
1096 int sk_setsockopt(struct sock *sk, int level, int optname,
1097 		  sockptr_t optval, unsigned int optlen)
1098 {
1099 	struct so_timestamping timestamping;
1100 	struct socket *sock = sk->sk_socket;
1101 	struct sock_txtime sk_txtime;
1102 	int val;
1103 	int valbool;
1104 	struct linger ling;
1105 	int ret = 0;
1106 
1107 	/*
1108 	 *	Options without arguments
1109 	 */
1110 
1111 	if (optname == SO_BINDTODEVICE)
1112 		return sock_setbindtodevice(sk, optval, optlen);
1113 
1114 	if (optlen < sizeof(int))
1115 		return -EINVAL;
1116 
1117 	if (copy_from_sockptr(&val, optval, sizeof(val)))
1118 		return -EFAULT;
1119 
1120 	valbool = val ? 1 : 0;
1121 
1122 	sockopt_lock_sock(sk);
1123 
1124 	switch (optname) {
1125 	case SO_DEBUG:
1126 		if (val && !sockopt_capable(CAP_NET_ADMIN))
1127 			ret = -EACCES;
1128 		else
1129 			sock_valbool_flag(sk, SOCK_DBG, valbool);
1130 		break;
1131 	case SO_REUSEADDR:
1132 		sk->sk_reuse = (valbool ? SK_CAN_REUSE : SK_NO_REUSE);
1133 		break;
1134 	case SO_REUSEPORT:
1135 		sk->sk_reuseport = valbool;
1136 		break;
1137 	case SO_TYPE:
1138 	case SO_PROTOCOL:
1139 	case SO_DOMAIN:
1140 	case SO_ERROR:
1141 		ret = -ENOPROTOOPT;
1142 		break;
1143 	case SO_DONTROUTE:
1144 		sock_valbool_flag(sk, SOCK_LOCALROUTE, valbool);
1145 		sk_dst_reset(sk);
1146 		break;
1147 	case SO_BROADCAST:
1148 		sock_valbool_flag(sk, SOCK_BROADCAST, valbool);
1149 		break;
1150 	case SO_SNDBUF:
1151 		/* Don't error on this BSD doesn't and if you think
1152 		 * about it this is right. Otherwise apps have to
1153 		 * play 'guess the biggest size' games. RCVBUF/SNDBUF
1154 		 * are treated in BSD as hints
1155 		 */
1156 		val = min_t(u32, val, READ_ONCE(sysctl_wmem_max));
1157 set_sndbuf:
1158 		/* Ensure val * 2 fits into an int, to prevent max_t()
1159 		 * from treating it as a negative value.
1160 		 */
1161 		val = min_t(int, val, INT_MAX / 2);
1162 		sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
1163 		WRITE_ONCE(sk->sk_sndbuf,
1164 			   max_t(int, val * 2, SOCK_MIN_SNDBUF));
1165 		/* Wake up sending tasks if we upped the value. */
1166 		sk->sk_write_space(sk);
1167 		break;
1168 
1169 	case SO_SNDBUFFORCE:
1170 		if (!sockopt_capable(CAP_NET_ADMIN)) {
1171 			ret = -EPERM;
1172 			break;
1173 		}
1174 
1175 		/* No negative values (to prevent underflow, as val will be
1176 		 * multiplied by 2).
1177 		 */
1178 		if (val < 0)
1179 			val = 0;
1180 		goto set_sndbuf;
1181 
1182 	case SO_RCVBUF:
1183 		/* Don't error on this BSD doesn't and if you think
1184 		 * about it this is right. Otherwise apps have to
1185 		 * play 'guess the biggest size' games. RCVBUF/SNDBUF
1186 		 * are treated in BSD as hints
1187 		 */
1188 		__sock_set_rcvbuf(sk, min_t(u32, val, READ_ONCE(sysctl_rmem_max)));
1189 		break;
1190 
1191 	case SO_RCVBUFFORCE:
1192 		if (!sockopt_capable(CAP_NET_ADMIN)) {
1193 			ret = -EPERM;
1194 			break;
1195 		}
1196 
1197 		/* No negative values (to prevent underflow, as val will be
1198 		 * multiplied by 2).
1199 		 */
1200 		__sock_set_rcvbuf(sk, max(val, 0));
1201 		break;
1202 
1203 	case SO_KEEPALIVE:
1204 		if (sk->sk_prot->keepalive)
1205 			sk->sk_prot->keepalive(sk, valbool);
1206 		sock_valbool_flag(sk, SOCK_KEEPOPEN, valbool);
1207 		break;
1208 
1209 	case SO_OOBINLINE:
1210 		sock_valbool_flag(sk, SOCK_URGINLINE, valbool);
1211 		break;
1212 
1213 	case SO_NO_CHECK:
1214 		sk->sk_no_check_tx = valbool;
1215 		break;
1216 
1217 	case SO_PRIORITY:
1218 		if ((val >= 0 && val <= 6) ||
1219 		    sockopt_ns_capable(sock_net(sk)->user_ns, CAP_NET_RAW) ||
1220 		    sockopt_ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
1221 			WRITE_ONCE(sk->sk_priority, val);
1222 		else
1223 			ret = -EPERM;
1224 		break;
1225 
1226 	case SO_LINGER:
1227 		if (optlen < sizeof(ling)) {
1228 			ret = -EINVAL;	/* 1003.1g */
1229 			break;
1230 		}
1231 		if (copy_from_sockptr(&ling, optval, sizeof(ling))) {
1232 			ret = -EFAULT;
1233 			break;
1234 		}
1235 		if (!ling.l_onoff) {
1236 			sock_reset_flag(sk, SOCK_LINGER);
1237 		} else {
1238 			unsigned long t_sec = ling.l_linger;
1239 
1240 			if (t_sec >= MAX_SCHEDULE_TIMEOUT / HZ)
1241 				WRITE_ONCE(sk->sk_lingertime, MAX_SCHEDULE_TIMEOUT);
1242 			else
1243 				WRITE_ONCE(sk->sk_lingertime, t_sec * HZ);
1244 			sock_set_flag(sk, SOCK_LINGER);
1245 		}
1246 		break;
1247 
1248 	case SO_BSDCOMPAT:
1249 		break;
1250 
1251 	case SO_PASSCRED:
1252 		assign_bit(SOCK_PASSCRED, &sock->flags, valbool);
1253 		break;
1254 
1255 	case SO_PASSPIDFD:
1256 		assign_bit(SOCK_PASSPIDFD, &sock->flags, valbool);
1257 		break;
1258 
1259 	case SO_TIMESTAMP_OLD:
1260 	case SO_TIMESTAMP_NEW:
1261 	case SO_TIMESTAMPNS_OLD:
1262 	case SO_TIMESTAMPNS_NEW:
1263 		sock_set_timestamp(sk, optname, valbool);
1264 		break;
1265 
1266 	case SO_TIMESTAMPING_NEW:
1267 	case SO_TIMESTAMPING_OLD:
1268 		if (optlen == sizeof(timestamping)) {
1269 			if (copy_from_sockptr(&timestamping, optval,
1270 					      sizeof(timestamping))) {
1271 				ret = -EFAULT;
1272 				break;
1273 			}
1274 		} else {
1275 			memset(&timestamping, 0, sizeof(timestamping));
1276 			timestamping.flags = val;
1277 		}
1278 		ret = sock_set_timestamping(sk, optname, timestamping);
1279 		break;
1280 
1281 	case SO_RCVLOWAT:
1282 		{
1283 		int (*set_rcvlowat)(struct sock *sk, int val) = NULL;
1284 
1285 		if (val < 0)
1286 			val = INT_MAX;
1287 		if (sock)
1288 			set_rcvlowat = READ_ONCE(sock->ops)->set_rcvlowat;
1289 		if (set_rcvlowat)
1290 			ret = set_rcvlowat(sk, val);
1291 		else
1292 			WRITE_ONCE(sk->sk_rcvlowat, val ? : 1);
1293 		break;
1294 		}
1295 	case SO_RCVTIMEO_OLD:
1296 	case SO_RCVTIMEO_NEW:
1297 		ret = sock_set_timeout(&sk->sk_rcvtimeo, optval,
1298 				       optlen, optname == SO_RCVTIMEO_OLD);
1299 		break;
1300 
1301 	case SO_SNDTIMEO_OLD:
1302 	case SO_SNDTIMEO_NEW:
1303 		ret = sock_set_timeout(&sk->sk_sndtimeo, optval,
1304 				       optlen, optname == SO_SNDTIMEO_OLD);
1305 		break;
1306 
1307 	case SO_ATTACH_FILTER: {
1308 		struct sock_fprog fprog;
1309 
1310 		ret = copy_bpf_fprog_from_user(&fprog, optval, optlen);
1311 		if (!ret)
1312 			ret = sk_attach_filter(&fprog, sk);
1313 		break;
1314 	}
1315 	case SO_ATTACH_BPF:
1316 		ret = -EINVAL;
1317 		if (optlen == sizeof(u32)) {
1318 			u32 ufd;
1319 
1320 			ret = -EFAULT;
1321 			if (copy_from_sockptr(&ufd, optval, sizeof(ufd)))
1322 				break;
1323 
1324 			ret = sk_attach_bpf(ufd, sk);
1325 		}
1326 		break;
1327 
1328 	case SO_ATTACH_REUSEPORT_CBPF: {
1329 		struct sock_fprog fprog;
1330 
1331 		ret = copy_bpf_fprog_from_user(&fprog, optval, optlen);
1332 		if (!ret)
1333 			ret = sk_reuseport_attach_filter(&fprog, sk);
1334 		break;
1335 	}
1336 	case SO_ATTACH_REUSEPORT_EBPF:
1337 		ret = -EINVAL;
1338 		if (optlen == sizeof(u32)) {
1339 			u32 ufd;
1340 
1341 			ret = -EFAULT;
1342 			if (copy_from_sockptr(&ufd, optval, sizeof(ufd)))
1343 				break;
1344 
1345 			ret = sk_reuseport_attach_bpf(ufd, sk);
1346 		}
1347 		break;
1348 
1349 	case SO_DETACH_REUSEPORT_BPF:
1350 		ret = reuseport_detach_prog(sk);
1351 		break;
1352 
1353 	case SO_DETACH_FILTER:
1354 		ret = sk_detach_filter(sk);
1355 		break;
1356 
1357 	case SO_LOCK_FILTER:
1358 		if (sock_flag(sk, SOCK_FILTER_LOCKED) && !valbool)
1359 			ret = -EPERM;
1360 		else
1361 			sock_valbool_flag(sk, SOCK_FILTER_LOCKED, valbool);
1362 		break;
1363 
1364 	case SO_PASSSEC:
1365 		assign_bit(SOCK_PASSSEC, &sock->flags, valbool);
1366 		break;
1367 	case SO_MARK:
1368 		if (!sockopt_ns_capable(sock_net(sk)->user_ns, CAP_NET_RAW) &&
1369 		    !sockopt_ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) {
1370 			ret = -EPERM;
1371 			break;
1372 		}
1373 
1374 		__sock_set_mark(sk, val);
1375 		break;
1376 	case SO_RCVMARK:
1377 		sock_valbool_flag(sk, SOCK_RCVMARK, valbool);
1378 		break;
1379 
1380 	case SO_RXQ_OVFL:
1381 		sock_valbool_flag(sk, SOCK_RXQ_OVFL, valbool);
1382 		break;
1383 
1384 	case SO_WIFI_STATUS:
1385 		sock_valbool_flag(sk, SOCK_WIFI_STATUS, valbool);
1386 		break;
1387 
1388 	case SO_PEEK_OFF:
1389 		{
1390 		int (*set_peek_off)(struct sock *sk, int val);
1391 
1392 		set_peek_off = READ_ONCE(sock->ops)->set_peek_off;
1393 		if (set_peek_off)
1394 			ret = set_peek_off(sk, val);
1395 		else
1396 			ret = -EOPNOTSUPP;
1397 		break;
1398 		}
1399 
1400 	case SO_NOFCS:
1401 		sock_valbool_flag(sk, SOCK_NOFCS, valbool);
1402 		break;
1403 
1404 	case SO_SELECT_ERR_QUEUE:
1405 		sock_valbool_flag(sk, SOCK_SELECT_ERR_QUEUE, valbool);
1406 		break;
1407 
1408 #ifdef CONFIG_NET_RX_BUSY_POLL
1409 	case SO_BUSY_POLL:
1410 		if (val < 0)
1411 			ret = -EINVAL;
1412 		else
1413 			WRITE_ONCE(sk->sk_ll_usec, val);
1414 		break;
1415 	case SO_PREFER_BUSY_POLL:
1416 		if (valbool && !sockopt_capable(CAP_NET_ADMIN))
1417 			ret = -EPERM;
1418 		else
1419 			WRITE_ONCE(sk->sk_prefer_busy_poll, valbool);
1420 		break;
1421 	case SO_BUSY_POLL_BUDGET:
1422 		if (val > READ_ONCE(sk->sk_busy_poll_budget) && !sockopt_capable(CAP_NET_ADMIN)) {
1423 			ret = -EPERM;
1424 		} else {
1425 			if (val < 0 || val > U16_MAX)
1426 				ret = -EINVAL;
1427 			else
1428 				WRITE_ONCE(sk->sk_busy_poll_budget, val);
1429 		}
1430 		break;
1431 #endif
1432 
1433 	case SO_MAX_PACING_RATE:
1434 		{
1435 		unsigned long ulval = (val == ~0U) ? ~0UL : (unsigned int)val;
1436 
1437 		if (sizeof(ulval) != sizeof(val) &&
1438 		    optlen >= sizeof(ulval) &&
1439 		    copy_from_sockptr(&ulval, optval, sizeof(ulval))) {
1440 			ret = -EFAULT;
1441 			break;
1442 		}
1443 		if (ulval != ~0UL)
1444 			cmpxchg(&sk->sk_pacing_status,
1445 				SK_PACING_NONE,
1446 				SK_PACING_NEEDED);
1447 		/* Pairs with READ_ONCE() from sk_getsockopt() */
1448 		WRITE_ONCE(sk->sk_max_pacing_rate, ulval);
1449 		sk->sk_pacing_rate = min(sk->sk_pacing_rate, ulval);
1450 		break;
1451 		}
1452 	case SO_INCOMING_CPU:
1453 		reuseport_update_incoming_cpu(sk, val);
1454 		break;
1455 
1456 	case SO_CNX_ADVICE:
1457 		if (val == 1)
1458 			dst_negative_advice(sk);
1459 		break;
1460 
1461 	case SO_ZEROCOPY:
1462 		if (sk->sk_family == PF_INET || sk->sk_family == PF_INET6) {
1463 			if (!(sk_is_tcp(sk) ||
1464 			      (sk->sk_type == SOCK_DGRAM &&
1465 			       sk->sk_protocol == IPPROTO_UDP)))
1466 				ret = -EOPNOTSUPP;
1467 		} else if (sk->sk_family != PF_RDS) {
1468 			ret = -EOPNOTSUPP;
1469 		}
1470 		if (!ret) {
1471 			if (val < 0 || val > 1)
1472 				ret = -EINVAL;
1473 			else
1474 				sock_valbool_flag(sk, SOCK_ZEROCOPY, valbool);
1475 		}
1476 		break;
1477 
1478 	case SO_TXTIME:
1479 		if (optlen != sizeof(struct sock_txtime)) {
1480 			ret = -EINVAL;
1481 			break;
1482 		} else if (copy_from_sockptr(&sk_txtime, optval,
1483 			   sizeof(struct sock_txtime))) {
1484 			ret = -EFAULT;
1485 			break;
1486 		} else if (sk_txtime.flags & ~SOF_TXTIME_FLAGS_MASK) {
1487 			ret = -EINVAL;
1488 			break;
1489 		}
1490 		/* CLOCK_MONOTONIC is only used by sch_fq, and this packet
1491 		 * scheduler has enough safe guards.
1492 		 */
1493 		if (sk_txtime.clockid != CLOCK_MONOTONIC &&
1494 		    !sockopt_ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) {
1495 			ret = -EPERM;
1496 			break;
1497 		}
1498 		sock_valbool_flag(sk, SOCK_TXTIME, true);
1499 		sk->sk_clockid = sk_txtime.clockid;
1500 		sk->sk_txtime_deadline_mode =
1501 			!!(sk_txtime.flags & SOF_TXTIME_DEADLINE_MODE);
1502 		sk->sk_txtime_report_errors =
1503 			!!(sk_txtime.flags & SOF_TXTIME_REPORT_ERRORS);
1504 		break;
1505 
1506 	case SO_BINDTOIFINDEX:
1507 		ret = sock_bindtoindex_locked(sk, val);
1508 		break;
1509 
1510 	case SO_BUF_LOCK:
1511 		if (val & ~SOCK_BUF_LOCK_MASK) {
1512 			ret = -EINVAL;
1513 			break;
1514 		}
1515 		sk->sk_userlocks = val | (sk->sk_userlocks &
1516 					  ~SOCK_BUF_LOCK_MASK);
1517 		break;
1518 
1519 	case SO_RESERVE_MEM:
1520 	{
1521 		int delta;
1522 
1523 		if (val < 0) {
1524 			ret = -EINVAL;
1525 			break;
1526 		}
1527 
1528 		delta = val - sk->sk_reserved_mem;
1529 		if (delta < 0)
1530 			sock_release_reserved_memory(sk, -delta);
1531 		else
1532 			ret = sock_reserve_memory(sk, delta);
1533 		break;
1534 	}
1535 
1536 	case SO_TXREHASH:
1537 		if (val < -1 || val > 1) {
1538 			ret = -EINVAL;
1539 			break;
1540 		}
1541 		if ((u8)val == SOCK_TXREHASH_DEFAULT)
1542 			val = READ_ONCE(sock_net(sk)->core.sysctl_txrehash);
1543 		/* Paired with READ_ONCE() in tcp_rtx_synack()
1544 		 * and sk_getsockopt().
1545 		 */
1546 		WRITE_ONCE(sk->sk_txrehash, (u8)val);
1547 		break;
1548 
1549 	default:
1550 		ret = -ENOPROTOOPT;
1551 		break;
1552 	}
1553 	sockopt_release_sock(sk);
1554 	return ret;
1555 }
1556 
1557 int sock_setsockopt(struct socket *sock, int level, int optname,
1558 		    sockptr_t optval, unsigned int optlen)
1559 {
1560 	return sk_setsockopt(sock->sk, level, optname,
1561 			     optval, optlen);
1562 }
1563 EXPORT_SYMBOL(sock_setsockopt);
1564 
1565 static const struct cred *sk_get_peer_cred(struct sock *sk)
1566 {
1567 	const struct cred *cred;
1568 
1569 	spin_lock(&sk->sk_peer_lock);
1570 	cred = get_cred(sk->sk_peer_cred);
1571 	spin_unlock(&sk->sk_peer_lock);
1572 
1573 	return cred;
1574 }
1575 
1576 static void cred_to_ucred(struct pid *pid, const struct cred *cred,
1577 			  struct ucred *ucred)
1578 {
1579 	ucred->pid = pid_vnr(pid);
1580 	ucred->uid = ucred->gid = -1;
1581 	if (cred) {
1582 		struct user_namespace *current_ns = current_user_ns();
1583 
1584 		ucred->uid = from_kuid_munged(current_ns, cred->euid);
1585 		ucred->gid = from_kgid_munged(current_ns, cred->egid);
1586 	}
1587 }
1588 
1589 static int groups_to_user(sockptr_t dst, const struct group_info *src)
1590 {
1591 	struct user_namespace *user_ns = current_user_ns();
1592 	int i;
1593 
1594 	for (i = 0; i < src->ngroups; i++) {
1595 		gid_t gid = from_kgid_munged(user_ns, src->gid[i]);
1596 
1597 		if (copy_to_sockptr_offset(dst, i * sizeof(gid), &gid, sizeof(gid)))
1598 			return -EFAULT;
1599 	}
1600 
1601 	return 0;
1602 }
1603 
1604 int sk_getsockopt(struct sock *sk, int level, int optname,
1605 		  sockptr_t optval, sockptr_t optlen)
1606 {
1607 	struct socket *sock = sk->sk_socket;
1608 
1609 	union {
1610 		int val;
1611 		u64 val64;
1612 		unsigned long ulval;
1613 		struct linger ling;
1614 		struct old_timeval32 tm32;
1615 		struct __kernel_old_timeval tm;
1616 		struct  __kernel_sock_timeval stm;
1617 		struct sock_txtime txtime;
1618 		struct so_timestamping timestamping;
1619 	} v;
1620 
1621 	int lv = sizeof(int);
1622 	int len;
1623 
1624 	if (copy_from_sockptr(&len, optlen, sizeof(int)))
1625 		return -EFAULT;
1626 	if (len < 0)
1627 		return -EINVAL;
1628 
1629 	memset(&v, 0, sizeof(v));
1630 
1631 	switch (optname) {
1632 	case SO_DEBUG:
1633 		v.val = sock_flag(sk, SOCK_DBG);
1634 		break;
1635 
1636 	case SO_DONTROUTE:
1637 		v.val = sock_flag(sk, SOCK_LOCALROUTE);
1638 		break;
1639 
1640 	case SO_BROADCAST:
1641 		v.val = sock_flag(sk, SOCK_BROADCAST);
1642 		break;
1643 
1644 	case SO_SNDBUF:
1645 		v.val = READ_ONCE(sk->sk_sndbuf);
1646 		break;
1647 
1648 	case SO_RCVBUF:
1649 		v.val = READ_ONCE(sk->sk_rcvbuf);
1650 		break;
1651 
1652 	case SO_REUSEADDR:
1653 		v.val = sk->sk_reuse;
1654 		break;
1655 
1656 	case SO_REUSEPORT:
1657 		v.val = sk->sk_reuseport;
1658 		break;
1659 
1660 	case SO_KEEPALIVE:
1661 		v.val = sock_flag(sk, SOCK_KEEPOPEN);
1662 		break;
1663 
1664 	case SO_TYPE:
1665 		v.val = sk->sk_type;
1666 		break;
1667 
1668 	case SO_PROTOCOL:
1669 		v.val = sk->sk_protocol;
1670 		break;
1671 
1672 	case SO_DOMAIN:
1673 		v.val = sk->sk_family;
1674 		break;
1675 
1676 	case SO_ERROR:
1677 		v.val = -sock_error(sk);
1678 		if (v.val == 0)
1679 			v.val = xchg(&sk->sk_err_soft, 0);
1680 		break;
1681 
1682 	case SO_OOBINLINE:
1683 		v.val = sock_flag(sk, SOCK_URGINLINE);
1684 		break;
1685 
1686 	case SO_NO_CHECK:
1687 		v.val = sk->sk_no_check_tx;
1688 		break;
1689 
1690 	case SO_PRIORITY:
1691 		v.val = READ_ONCE(sk->sk_priority);
1692 		break;
1693 
1694 	case SO_LINGER:
1695 		lv		= sizeof(v.ling);
1696 		v.ling.l_onoff	= sock_flag(sk, SOCK_LINGER);
1697 		v.ling.l_linger	= READ_ONCE(sk->sk_lingertime) / HZ;
1698 		break;
1699 
1700 	case SO_BSDCOMPAT:
1701 		break;
1702 
1703 	case SO_TIMESTAMP_OLD:
1704 		v.val = sock_flag(sk, SOCK_RCVTSTAMP) &&
1705 				!sock_flag(sk, SOCK_TSTAMP_NEW) &&
1706 				!sock_flag(sk, SOCK_RCVTSTAMPNS);
1707 		break;
1708 
1709 	case SO_TIMESTAMPNS_OLD:
1710 		v.val = sock_flag(sk, SOCK_RCVTSTAMPNS) && !sock_flag(sk, SOCK_TSTAMP_NEW);
1711 		break;
1712 
1713 	case SO_TIMESTAMP_NEW:
1714 		v.val = sock_flag(sk, SOCK_RCVTSTAMP) && sock_flag(sk, SOCK_TSTAMP_NEW);
1715 		break;
1716 
1717 	case SO_TIMESTAMPNS_NEW:
1718 		v.val = sock_flag(sk, SOCK_RCVTSTAMPNS) && sock_flag(sk, SOCK_TSTAMP_NEW);
1719 		break;
1720 
1721 	case SO_TIMESTAMPING_OLD:
1722 	case SO_TIMESTAMPING_NEW:
1723 		lv = sizeof(v.timestamping);
1724 		/* For the later-added case SO_TIMESTAMPING_NEW: Be strict about only
1725 		 * returning the flags when they were set through the same option.
1726 		 * Don't change the beviour for the old case SO_TIMESTAMPING_OLD.
1727 		 */
1728 		if (optname == SO_TIMESTAMPING_OLD || sock_flag(sk, SOCK_TSTAMP_NEW)) {
1729 			v.timestamping.flags = READ_ONCE(sk->sk_tsflags);
1730 			v.timestamping.bind_phc = READ_ONCE(sk->sk_bind_phc);
1731 		}
1732 		break;
1733 
1734 	case SO_RCVTIMEO_OLD:
1735 	case SO_RCVTIMEO_NEW:
1736 		lv = sock_get_timeout(READ_ONCE(sk->sk_rcvtimeo), &v,
1737 				      SO_RCVTIMEO_OLD == optname);
1738 		break;
1739 
1740 	case SO_SNDTIMEO_OLD:
1741 	case SO_SNDTIMEO_NEW:
1742 		lv = sock_get_timeout(READ_ONCE(sk->sk_sndtimeo), &v,
1743 				      SO_SNDTIMEO_OLD == optname);
1744 		break;
1745 
1746 	case SO_RCVLOWAT:
1747 		v.val = READ_ONCE(sk->sk_rcvlowat);
1748 		break;
1749 
1750 	case SO_SNDLOWAT:
1751 		v.val = 1;
1752 		break;
1753 
1754 	case SO_PASSCRED:
1755 		v.val = !!test_bit(SOCK_PASSCRED, &sock->flags);
1756 		break;
1757 
1758 	case SO_PASSPIDFD:
1759 		v.val = !!test_bit(SOCK_PASSPIDFD, &sock->flags);
1760 		break;
1761 
1762 	case SO_PEERCRED:
1763 	{
1764 		struct ucred peercred;
1765 		if (len > sizeof(peercred))
1766 			len = sizeof(peercred);
1767 
1768 		spin_lock(&sk->sk_peer_lock);
1769 		cred_to_ucred(sk->sk_peer_pid, sk->sk_peer_cred, &peercred);
1770 		spin_unlock(&sk->sk_peer_lock);
1771 
1772 		if (copy_to_sockptr(optval, &peercred, len))
1773 			return -EFAULT;
1774 		goto lenout;
1775 	}
1776 
1777 	case SO_PEERPIDFD:
1778 	{
1779 		struct pid *peer_pid;
1780 		struct file *pidfd_file = NULL;
1781 		int pidfd;
1782 
1783 		if (len > sizeof(pidfd))
1784 			len = sizeof(pidfd);
1785 
1786 		spin_lock(&sk->sk_peer_lock);
1787 		peer_pid = get_pid(sk->sk_peer_pid);
1788 		spin_unlock(&sk->sk_peer_lock);
1789 
1790 		if (!peer_pid)
1791 			return -ENODATA;
1792 
1793 		pidfd = pidfd_prepare(peer_pid, 0, &pidfd_file);
1794 		put_pid(peer_pid);
1795 		if (pidfd < 0)
1796 			return pidfd;
1797 
1798 		if (copy_to_sockptr(optval, &pidfd, len) ||
1799 		    copy_to_sockptr(optlen, &len, sizeof(int))) {
1800 			put_unused_fd(pidfd);
1801 			fput(pidfd_file);
1802 
1803 			return -EFAULT;
1804 		}
1805 
1806 		fd_install(pidfd, pidfd_file);
1807 		return 0;
1808 	}
1809 
1810 	case SO_PEERGROUPS:
1811 	{
1812 		const struct cred *cred;
1813 		int ret, n;
1814 
1815 		cred = sk_get_peer_cred(sk);
1816 		if (!cred)
1817 			return -ENODATA;
1818 
1819 		n = cred->group_info->ngroups;
1820 		if (len < n * sizeof(gid_t)) {
1821 			len = n * sizeof(gid_t);
1822 			put_cred(cred);
1823 			return copy_to_sockptr(optlen, &len, sizeof(int)) ? -EFAULT : -ERANGE;
1824 		}
1825 		len = n * sizeof(gid_t);
1826 
1827 		ret = groups_to_user(optval, cred->group_info);
1828 		put_cred(cred);
1829 		if (ret)
1830 			return ret;
1831 		goto lenout;
1832 	}
1833 
1834 	case SO_PEERNAME:
1835 	{
1836 		struct sockaddr_storage address;
1837 
1838 		lv = READ_ONCE(sock->ops)->getname(sock, (struct sockaddr *)&address, 2);
1839 		if (lv < 0)
1840 			return -ENOTCONN;
1841 		if (lv < len)
1842 			return -EINVAL;
1843 		if (copy_to_sockptr(optval, &address, len))
1844 			return -EFAULT;
1845 		goto lenout;
1846 	}
1847 
1848 	/* Dubious BSD thing... Probably nobody even uses it, but
1849 	 * the UNIX standard wants it for whatever reason... -DaveM
1850 	 */
1851 	case SO_ACCEPTCONN:
1852 		v.val = sk->sk_state == TCP_LISTEN;
1853 		break;
1854 
1855 	case SO_PASSSEC:
1856 		v.val = !!test_bit(SOCK_PASSSEC, &sock->flags);
1857 		break;
1858 
1859 	case SO_PEERSEC:
1860 		return security_socket_getpeersec_stream(sock,
1861 							 optval, optlen, len);
1862 
1863 	case SO_MARK:
1864 		v.val = READ_ONCE(sk->sk_mark);
1865 		break;
1866 
1867 	case SO_RCVMARK:
1868 		v.val = sock_flag(sk, SOCK_RCVMARK);
1869 		break;
1870 
1871 	case SO_RXQ_OVFL:
1872 		v.val = sock_flag(sk, SOCK_RXQ_OVFL);
1873 		break;
1874 
1875 	case SO_WIFI_STATUS:
1876 		v.val = sock_flag(sk, SOCK_WIFI_STATUS);
1877 		break;
1878 
1879 	case SO_PEEK_OFF:
1880 		if (!READ_ONCE(sock->ops)->set_peek_off)
1881 			return -EOPNOTSUPP;
1882 
1883 		v.val = READ_ONCE(sk->sk_peek_off);
1884 		break;
1885 	case SO_NOFCS:
1886 		v.val = sock_flag(sk, SOCK_NOFCS);
1887 		break;
1888 
1889 	case SO_BINDTODEVICE:
1890 		return sock_getbindtodevice(sk, optval, optlen, len);
1891 
1892 	case SO_GET_FILTER:
1893 		len = sk_get_filter(sk, optval, len);
1894 		if (len < 0)
1895 			return len;
1896 
1897 		goto lenout;
1898 
1899 	case SO_LOCK_FILTER:
1900 		v.val = sock_flag(sk, SOCK_FILTER_LOCKED);
1901 		break;
1902 
1903 	case SO_BPF_EXTENSIONS:
1904 		v.val = bpf_tell_extensions();
1905 		break;
1906 
1907 	case SO_SELECT_ERR_QUEUE:
1908 		v.val = sock_flag(sk, SOCK_SELECT_ERR_QUEUE);
1909 		break;
1910 
1911 #ifdef CONFIG_NET_RX_BUSY_POLL
1912 	case SO_BUSY_POLL:
1913 		v.val = READ_ONCE(sk->sk_ll_usec);
1914 		break;
1915 	case SO_PREFER_BUSY_POLL:
1916 		v.val = READ_ONCE(sk->sk_prefer_busy_poll);
1917 		break;
1918 #endif
1919 
1920 	case SO_MAX_PACING_RATE:
1921 		/* The READ_ONCE() pair with the WRITE_ONCE() in sk_setsockopt() */
1922 		if (sizeof(v.ulval) != sizeof(v.val) && len >= sizeof(v.ulval)) {
1923 			lv = sizeof(v.ulval);
1924 			v.ulval = READ_ONCE(sk->sk_max_pacing_rate);
1925 		} else {
1926 			/* 32bit version */
1927 			v.val = min_t(unsigned long, ~0U,
1928 				      READ_ONCE(sk->sk_max_pacing_rate));
1929 		}
1930 		break;
1931 
1932 	case SO_INCOMING_CPU:
1933 		v.val = READ_ONCE(sk->sk_incoming_cpu);
1934 		break;
1935 
1936 	case SO_MEMINFO:
1937 	{
1938 		u32 meminfo[SK_MEMINFO_VARS];
1939 
1940 		sk_get_meminfo(sk, meminfo);
1941 
1942 		len = min_t(unsigned int, len, sizeof(meminfo));
1943 		if (copy_to_sockptr(optval, &meminfo, len))
1944 			return -EFAULT;
1945 
1946 		goto lenout;
1947 	}
1948 
1949 #ifdef CONFIG_NET_RX_BUSY_POLL
1950 	case SO_INCOMING_NAPI_ID:
1951 		v.val = READ_ONCE(sk->sk_napi_id);
1952 
1953 		/* aggregate non-NAPI IDs down to 0 */
1954 		if (v.val < MIN_NAPI_ID)
1955 			v.val = 0;
1956 
1957 		break;
1958 #endif
1959 
1960 	case SO_COOKIE:
1961 		lv = sizeof(u64);
1962 		if (len < lv)
1963 			return -EINVAL;
1964 		v.val64 = sock_gen_cookie(sk);
1965 		break;
1966 
1967 	case SO_ZEROCOPY:
1968 		v.val = sock_flag(sk, SOCK_ZEROCOPY);
1969 		break;
1970 
1971 	case SO_TXTIME:
1972 		lv = sizeof(v.txtime);
1973 		v.txtime.clockid = sk->sk_clockid;
1974 		v.txtime.flags |= sk->sk_txtime_deadline_mode ?
1975 				  SOF_TXTIME_DEADLINE_MODE : 0;
1976 		v.txtime.flags |= sk->sk_txtime_report_errors ?
1977 				  SOF_TXTIME_REPORT_ERRORS : 0;
1978 		break;
1979 
1980 	case SO_BINDTOIFINDEX:
1981 		v.val = READ_ONCE(sk->sk_bound_dev_if);
1982 		break;
1983 
1984 	case SO_NETNS_COOKIE:
1985 		lv = sizeof(u64);
1986 		if (len != lv)
1987 			return -EINVAL;
1988 		v.val64 = sock_net(sk)->net_cookie;
1989 		break;
1990 
1991 	case SO_BUF_LOCK:
1992 		v.val = sk->sk_userlocks & SOCK_BUF_LOCK_MASK;
1993 		break;
1994 
1995 	case SO_RESERVE_MEM:
1996 		v.val = READ_ONCE(sk->sk_reserved_mem);
1997 		break;
1998 
1999 	case SO_TXREHASH:
2000 		/* Paired with WRITE_ONCE() in sk_setsockopt() */
2001 		v.val = READ_ONCE(sk->sk_txrehash);
2002 		break;
2003 
2004 	default:
2005 		/* We implement the SO_SNDLOWAT etc to not be settable
2006 		 * (1003.1g 7).
2007 		 */
2008 		return -ENOPROTOOPT;
2009 	}
2010 
2011 	if (len > lv)
2012 		len = lv;
2013 	if (copy_to_sockptr(optval, &v, len))
2014 		return -EFAULT;
2015 lenout:
2016 	if (copy_to_sockptr(optlen, &len, sizeof(int)))
2017 		return -EFAULT;
2018 	return 0;
2019 }
2020 
2021 int sock_getsockopt(struct socket *sock, int level, int optname,
2022 		    char __user *optval, int __user *optlen)
2023 {
2024 	return sk_getsockopt(sock->sk, level, optname,
2025 			     USER_SOCKPTR(optval),
2026 			     USER_SOCKPTR(optlen));
2027 }
2028 
2029 /*
2030  * Initialize an sk_lock.
2031  *
2032  * (We also register the sk_lock with the lock validator.)
2033  */
2034 static inline void sock_lock_init(struct sock *sk)
2035 {
2036 	if (sk->sk_kern_sock)
2037 		sock_lock_init_class_and_name(
2038 			sk,
2039 			af_family_kern_slock_key_strings[sk->sk_family],
2040 			af_family_kern_slock_keys + sk->sk_family,
2041 			af_family_kern_key_strings[sk->sk_family],
2042 			af_family_kern_keys + sk->sk_family);
2043 	else
2044 		sock_lock_init_class_and_name(
2045 			sk,
2046 			af_family_slock_key_strings[sk->sk_family],
2047 			af_family_slock_keys + sk->sk_family,
2048 			af_family_key_strings[sk->sk_family],
2049 			af_family_keys + sk->sk_family);
2050 }
2051 
2052 /*
2053  * Copy all fields from osk to nsk but nsk->sk_refcnt must not change yet,
2054  * even temporarly, because of RCU lookups. sk_node should also be left as is.
2055  * We must not copy fields between sk_dontcopy_begin and sk_dontcopy_end
2056  */
2057 static void sock_copy(struct sock *nsk, const struct sock *osk)
2058 {
2059 	const struct proto *prot = READ_ONCE(osk->sk_prot);
2060 #ifdef CONFIG_SECURITY_NETWORK
2061 	void *sptr = nsk->sk_security;
2062 #endif
2063 
2064 	/* If we move sk_tx_queue_mapping out of the private section,
2065 	 * we must check if sk_tx_queue_clear() is called after
2066 	 * sock_copy() in sk_clone_lock().
2067 	 */
2068 	BUILD_BUG_ON(offsetof(struct sock, sk_tx_queue_mapping) <
2069 		     offsetof(struct sock, sk_dontcopy_begin) ||
2070 		     offsetof(struct sock, sk_tx_queue_mapping) >=
2071 		     offsetof(struct sock, sk_dontcopy_end));
2072 
2073 	memcpy(nsk, osk, offsetof(struct sock, sk_dontcopy_begin));
2074 
2075 	memcpy(&nsk->sk_dontcopy_end, &osk->sk_dontcopy_end,
2076 	       prot->obj_size - offsetof(struct sock, sk_dontcopy_end));
2077 
2078 #ifdef CONFIG_SECURITY_NETWORK
2079 	nsk->sk_security = sptr;
2080 	security_sk_clone(osk, nsk);
2081 #endif
2082 }
2083 
2084 static struct sock *sk_prot_alloc(struct proto *prot, gfp_t priority,
2085 		int family)
2086 {
2087 	struct sock *sk;
2088 	struct kmem_cache *slab;
2089 
2090 	slab = prot->slab;
2091 	if (slab != NULL) {
2092 		sk = kmem_cache_alloc(slab, priority & ~__GFP_ZERO);
2093 		if (!sk)
2094 			return sk;
2095 		if (want_init_on_alloc(priority))
2096 			sk_prot_clear_nulls(sk, prot->obj_size);
2097 	} else
2098 		sk = kmalloc(prot->obj_size, priority);
2099 
2100 	if (sk != NULL) {
2101 		if (security_sk_alloc(sk, family, priority))
2102 			goto out_free;
2103 
2104 		if (!try_module_get(prot->owner))
2105 			goto out_free_sec;
2106 	}
2107 
2108 	return sk;
2109 
2110 out_free_sec:
2111 	security_sk_free(sk);
2112 out_free:
2113 	if (slab != NULL)
2114 		kmem_cache_free(slab, sk);
2115 	else
2116 		kfree(sk);
2117 	return NULL;
2118 }
2119 
2120 static void sk_prot_free(struct proto *prot, struct sock *sk)
2121 {
2122 	struct kmem_cache *slab;
2123 	struct module *owner;
2124 
2125 	owner = prot->owner;
2126 	slab = prot->slab;
2127 
2128 	cgroup_sk_free(&sk->sk_cgrp_data);
2129 	mem_cgroup_sk_free(sk);
2130 	security_sk_free(sk);
2131 	if (slab != NULL)
2132 		kmem_cache_free(slab, sk);
2133 	else
2134 		kfree(sk);
2135 	module_put(owner);
2136 }
2137 
2138 /**
2139  *	sk_alloc - All socket objects are allocated here
2140  *	@net: the applicable net namespace
2141  *	@family: protocol family
2142  *	@priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
2143  *	@prot: struct proto associated with this new sock instance
2144  *	@kern: is this to be a kernel socket?
2145  */
2146 struct sock *sk_alloc(struct net *net, int family, gfp_t priority,
2147 		      struct proto *prot, int kern)
2148 {
2149 	struct sock *sk;
2150 
2151 	sk = sk_prot_alloc(prot, priority | __GFP_ZERO, family);
2152 	if (sk) {
2153 		sk->sk_family = family;
2154 		/*
2155 		 * See comment in struct sock definition to understand
2156 		 * why we need sk_prot_creator -acme
2157 		 */
2158 		sk->sk_prot = sk->sk_prot_creator = prot;
2159 		sk->sk_kern_sock = kern;
2160 		sock_lock_init(sk);
2161 		sk->sk_net_refcnt = kern ? 0 : 1;
2162 		if (likely(sk->sk_net_refcnt)) {
2163 			get_net_track(net, &sk->ns_tracker, priority);
2164 			sock_inuse_add(net, 1);
2165 		} else {
2166 			__netns_tracker_alloc(net, &sk->ns_tracker,
2167 					      false, priority);
2168 		}
2169 
2170 		sock_net_set(sk, net);
2171 		refcount_set(&sk->sk_wmem_alloc, 1);
2172 
2173 		mem_cgroup_sk_alloc(sk);
2174 		cgroup_sk_alloc(&sk->sk_cgrp_data);
2175 		sock_update_classid(&sk->sk_cgrp_data);
2176 		sock_update_netprioidx(&sk->sk_cgrp_data);
2177 		sk_tx_queue_clear(sk);
2178 	}
2179 
2180 	return sk;
2181 }
2182 EXPORT_SYMBOL(sk_alloc);
2183 
2184 /* Sockets having SOCK_RCU_FREE will call this function after one RCU
2185  * grace period. This is the case for UDP sockets and TCP listeners.
2186  */
2187 static void __sk_destruct(struct rcu_head *head)
2188 {
2189 	struct sock *sk = container_of(head, struct sock, sk_rcu);
2190 	struct sk_filter *filter;
2191 
2192 	if (sk->sk_destruct)
2193 		sk->sk_destruct(sk);
2194 
2195 	filter = rcu_dereference_check(sk->sk_filter,
2196 				       refcount_read(&sk->sk_wmem_alloc) == 0);
2197 	if (filter) {
2198 		sk_filter_uncharge(sk, filter);
2199 		RCU_INIT_POINTER(sk->sk_filter, NULL);
2200 	}
2201 
2202 	sock_disable_timestamp(sk, SK_FLAGS_TIMESTAMP);
2203 
2204 #ifdef CONFIG_BPF_SYSCALL
2205 	bpf_sk_storage_free(sk);
2206 #endif
2207 
2208 	if (atomic_read(&sk->sk_omem_alloc))
2209 		pr_debug("%s: optmem leakage (%d bytes) detected\n",
2210 			 __func__, atomic_read(&sk->sk_omem_alloc));
2211 
2212 	if (sk->sk_frag.page) {
2213 		put_page(sk->sk_frag.page);
2214 		sk->sk_frag.page = NULL;
2215 	}
2216 
2217 	/* We do not need to acquire sk->sk_peer_lock, we are the last user. */
2218 	put_cred(sk->sk_peer_cred);
2219 	put_pid(sk->sk_peer_pid);
2220 
2221 	if (likely(sk->sk_net_refcnt))
2222 		put_net_track(sock_net(sk), &sk->ns_tracker);
2223 	else
2224 		__netns_tracker_free(sock_net(sk), &sk->ns_tracker, false);
2225 
2226 	sk_prot_free(sk->sk_prot_creator, sk);
2227 }
2228 
2229 void sk_destruct(struct sock *sk)
2230 {
2231 	bool use_call_rcu = sock_flag(sk, SOCK_RCU_FREE);
2232 
2233 	if (rcu_access_pointer(sk->sk_reuseport_cb)) {
2234 		reuseport_detach_sock(sk);
2235 		use_call_rcu = true;
2236 	}
2237 
2238 	if (use_call_rcu)
2239 		call_rcu(&sk->sk_rcu, __sk_destruct);
2240 	else
2241 		__sk_destruct(&sk->sk_rcu);
2242 }
2243 
2244 static void __sk_free(struct sock *sk)
2245 {
2246 	if (likely(sk->sk_net_refcnt))
2247 		sock_inuse_add(sock_net(sk), -1);
2248 
2249 	if (unlikely(sk->sk_net_refcnt && sock_diag_has_destroy_listeners(sk)))
2250 		sock_diag_broadcast_destroy(sk);
2251 	else
2252 		sk_destruct(sk);
2253 }
2254 
2255 void sk_free(struct sock *sk)
2256 {
2257 	/*
2258 	 * We subtract one from sk_wmem_alloc and can know if
2259 	 * some packets are still in some tx queue.
2260 	 * If not null, sock_wfree() will call __sk_free(sk) later
2261 	 */
2262 	if (refcount_dec_and_test(&sk->sk_wmem_alloc))
2263 		__sk_free(sk);
2264 }
2265 EXPORT_SYMBOL(sk_free);
2266 
2267 static void sk_init_common(struct sock *sk)
2268 {
2269 	skb_queue_head_init(&sk->sk_receive_queue);
2270 	skb_queue_head_init(&sk->sk_write_queue);
2271 	skb_queue_head_init(&sk->sk_error_queue);
2272 
2273 	rwlock_init(&sk->sk_callback_lock);
2274 	lockdep_set_class_and_name(&sk->sk_receive_queue.lock,
2275 			af_rlock_keys + sk->sk_family,
2276 			af_family_rlock_key_strings[sk->sk_family]);
2277 	lockdep_set_class_and_name(&sk->sk_write_queue.lock,
2278 			af_wlock_keys + sk->sk_family,
2279 			af_family_wlock_key_strings[sk->sk_family]);
2280 	lockdep_set_class_and_name(&sk->sk_error_queue.lock,
2281 			af_elock_keys + sk->sk_family,
2282 			af_family_elock_key_strings[sk->sk_family]);
2283 	lockdep_set_class_and_name(&sk->sk_callback_lock,
2284 			af_callback_keys + sk->sk_family,
2285 			af_family_clock_key_strings[sk->sk_family]);
2286 }
2287 
2288 /**
2289  *	sk_clone_lock - clone a socket, and lock its clone
2290  *	@sk: the socket to clone
2291  *	@priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
2292  *
2293  *	Caller must unlock socket even in error path (bh_unlock_sock(newsk))
2294  */
2295 struct sock *sk_clone_lock(const struct sock *sk, const gfp_t priority)
2296 {
2297 	struct proto *prot = READ_ONCE(sk->sk_prot);
2298 	struct sk_filter *filter;
2299 	bool is_charged = true;
2300 	struct sock *newsk;
2301 
2302 	newsk = sk_prot_alloc(prot, priority, sk->sk_family);
2303 	if (!newsk)
2304 		goto out;
2305 
2306 	sock_copy(newsk, sk);
2307 
2308 	newsk->sk_prot_creator = prot;
2309 
2310 	/* SANITY */
2311 	if (likely(newsk->sk_net_refcnt)) {
2312 		get_net_track(sock_net(newsk), &newsk->ns_tracker, priority);
2313 		sock_inuse_add(sock_net(newsk), 1);
2314 	} else {
2315 		/* Kernel sockets are not elevating the struct net refcount.
2316 		 * Instead, use a tracker to more easily detect if a layer
2317 		 * is not properly dismantling its kernel sockets at netns
2318 		 * destroy time.
2319 		 */
2320 		__netns_tracker_alloc(sock_net(newsk), &newsk->ns_tracker,
2321 				      false, priority);
2322 	}
2323 	sk_node_init(&newsk->sk_node);
2324 	sock_lock_init(newsk);
2325 	bh_lock_sock(newsk);
2326 	newsk->sk_backlog.head	= newsk->sk_backlog.tail = NULL;
2327 	newsk->sk_backlog.len = 0;
2328 
2329 	atomic_set(&newsk->sk_rmem_alloc, 0);
2330 
2331 	/* sk_wmem_alloc set to one (see sk_free() and sock_wfree()) */
2332 	refcount_set(&newsk->sk_wmem_alloc, 1);
2333 
2334 	atomic_set(&newsk->sk_omem_alloc, 0);
2335 	sk_init_common(newsk);
2336 
2337 	newsk->sk_dst_cache	= NULL;
2338 	newsk->sk_dst_pending_confirm = 0;
2339 	newsk->sk_wmem_queued	= 0;
2340 	newsk->sk_forward_alloc = 0;
2341 	newsk->sk_reserved_mem  = 0;
2342 	atomic_set(&newsk->sk_drops, 0);
2343 	newsk->sk_send_head	= NULL;
2344 	newsk->sk_userlocks	= sk->sk_userlocks & ~SOCK_BINDPORT_LOCK;
2345 	atomic_set(&newsk->sk_zckey, 0);
2346 
2347 	sock_reset_flag(newsk, SOCK_DONE);
2348 
2349 	/* sk->sk_memcg will be populated at accept() time */
2350 	newsk->sk_memcg = NULL;
2351 
2352 	cgroup_sk_clone(&newsk->sk_cgrp_data);
2353 
2354 	rcu_read_lock();
2355 	filter = rcu_dereference(sk->sk_filter);
2356 	if (filter != NULL)
2357 		/* though it's an empty new sock, the charging may fail
2358 		 * if sysctl_optmem_max was changed between creation of
2359 		 * original socket and cloning
2360 		 */
2361 		is_charged = sk_filter_charge(newsk, filter);
2362 	RCU_INIT_POINTER(newsk->sk_filter, filter);
2363 	rcu_read_unlock();
2364 
2365 	if (unlikely(!is_charged || xfrm_sk_clone_policy(newsk, sk))) {
2366 		/* We need to make sure that we don't uncharge the new
2367 		 * socket if we couldn't charge it in the first place
2368 		 * as otherwise we uncharge the parent's filter.
2369 		 */
2370 		if (!is_charged)
2371 			RCU_INIT_POINTER(newsk->sk_filter, NULL);
2372 		sk_free_unlock_clone(newsk);
2373 		newsk = NULL;
2374 		goto out;
2375 	}
2376 	RCU_INIT_POINTER(newsk->sk_reuseport_cb, NULL);
2377 
2378 	if (bpf_sk_storage_clone(sk, newsk)) {
2379 		sk_free_unlock_clone(newsk);
2380 		newsk = NULL;
2381 		goto out;
2382 	}
2383 
2384 	/* Clear sk_user_data if parent had the pointer tagged
2385 	 * as not suitable for copying when cloning.
2386 	 */
2387 	if (sk_user_data_is_nocopy(newsk))
2388 		newsk->sk_user_data = NULL;
2389 
2390 	newsk->sk_err	   = 0;
2391 	newsk->sk_err_soft = 0;
2392 	newsk->sk_priority = 0;
2393 	newsk->sk_incoming_cpu = raw_smp_processor_id();
2394 
2395 	/* Before updating sk_refcnt, we must commit prior changes to memory
2396 	 * (Documentation/RCU/rculist_nulls.rst for details)
2397 	 */
2398 	smp_wmb();
2399 	refcount_set(&newsk->sk_refcnt, 2);
2400 
2401 	sk_set_socket(newsk, NULL);
2402 	sk_tx_queue_clear(newsk);
2403 	RCU_INIT_POINTER(newsk->sk_wq, NULL);
2404 
2405 	if (newsk->sk_prot->sockets_allocated)
2406 		sk_sockets_allocated_inc(newsk);
2407 
2408 	if (sock_needs_netstamp(sk) && newsk->sk_flags & SK_FLAGS_TIMESTAMP)
2409 		net_enable_timestamp();
2410 out:
2411 	return newsk;
2412 }
2413 EXPORT_SYMBOL_GPL(sk_clone_lock);
2414 
2415 void sk_free_unlock_clone(struct sock *sk)
2416 {
2417 	/* It is still raw copy of parent, so invalidate
2418 	 * destructor and make plain sk_free() */
2419 	sk->sk_destruct = NULL;
2420 	bh_unlock_sock(sk);
2421 	sk_free(sk);
2422 }
2423 EXPORT_SYMBOL_GPL(sk_free_unlock_clone);
2424 
2425 static u32 sk_dst_gso_max_size(struct sock *sk, struct dst_entry *dst)
2426 {
2427 	bool is_ipv6 = false;
2428 	u32 max_size;
2429 
2430 #if IS_ENABLED(CONFIG_IPV6)
2431 	is_ipv6 = (sk->sk_family == AF_INET6 &&
2432 		   !ipv6_addr_v4mapped(&sk->sk_v6_rcv_saddr));
2433 #endif
2434 	/* pairs with the WRITE_ONCE() in netif_set_gso(_ipv4)_max_size() */
2435 	max_size = is_ipv6 ? READ_ONCE(dst->dev->gso_max_size) :
2436 			READ_ONCE(dst->dev->gso_ipv4_max_size);
2437 	if (max_size > GSO_LEGACY_MAX_SIZE && !sk_is_tcp(sk))
2438 		max_size = GSO_LEGACY_MAX_SIZE;
2439 
2440 	return max_size - (MAX_TCP_HEADER + 1);
2441 }
2442 
2443 void sk_setup_caps(struct sock *sk, struct dst_entry *dst)
2444 {
2445 	u32 max_segs = 1;
2446 
2447 	sk->sk_route_caps = dst->dev->features;
2448 	if (sk_is_tcp(sk))
2449 		sk->sk_route_caps |= NETIF_F_GSO;
2450 	if (sk->sk_route_caps & NETIF_F_GSO)
2451 		sk->sk_route_caps |= NETIF_F_GSO_SOFTWARE;
2452 	if (unlikely(sk->sk_gso_disabled))
2453 		sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
2454 	if (sk_can_gso(sk)) {
2455 		if (dst->header_len && !xfrm_dst_offload_ok(dst)) {
2456 			sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
2457 		} else {
2458 			sk->sk_route_caps |= NETIF_F_SG | NETIF_F_HW_CSUM;
2459 			sk->sk_gso_max_size = sk_dst_gso_max_size(sk, dst);
2460 			/* pairs with the WRITE_ONCE() in netif_set_gso_max_segs() */
2461 			max_segs = max_t(u32, READ_ONCE(dst->dev->gso_max_segs), 1);
2462 		}
2463 	}
2464 	sk->sk_gso_max_segs = max_segs;
2465 	sk_dst_set(sk, dst);
2466 }
2467 EXPORT_SYMBOL_GPL(sk_setup_caps);
2468 
2469 /*
2470  *	Simple resource managers for sockets.
2471  */
2472 
2473 
2474 /*
2475  * Write buffer destructor automatically called from kfree_skb.
2476  */
2477 void sock_wfree(struct sk_buff *skb)
2478 {
2479 	struct sock *sk = skb->sk;
2480 	unsigned int len = skb->truesize;
2481 	bool free;
2482 
2483 	if (!sock_flag(sk, SOCK_USE_WRITE_QUEUE)) {
2484 		if (sock_flag(sk, SOCK_RCU_FREE) &&
2485 		    sk->sk_write_space == sock_def_write_space) {
2486 			rcu_read_lock();
2487 			free = refcount_sub_and_test(len, &sk->sk_wmem_alloc);
2488 			sock_def_write_space_wfree(sk);
2489 			rcu_read_unlock();
2490 			if (unlikely(free))
2491 				__sk_free(sk);
2492 			return;
2493 		}
2494 
2495 		/*
2496 		 * Keep a reference on sk_wmem_alloc, this will be released
2497 		 * after sk_write_space() call
2498 		 */
2499 		WARN_ON(refcount_sub_and_test(len - 1, &sk->sk_wmem_alloc));
2500 		sk->sk_write_space(sk);
2501 		len = 1;
2502 	}
2503 	/*
2504 	 * if sk_wmem_alloc reaches 0, we must finish what sk_free()
2505 	 * could not do because of in-flight packets
2506 	 */
2507 	if (refcount_sub_and_test(len, &sk->sk_wmem_alloc))
2508 		__sk_free(sk);
2509 }
2510 EXPORT_SYMBOL(sock_wfree);
2511 
2512 /* This variant of sock_wfree() is used by TCP,
2513  * since it sets SOCK_USE_WRITE_QUEUE.
2514  */
2515 void __sock_wfree(struct sk_buff *skb)
2516 {
2517 	struct sock *sk = skb->sk;
2518 
2519 	if (refcount_sub_and_test(skb->truesize, &sk->sk_wmem_alloc))
2520 		__sk_free(sk);
2521 }
2522 
2523 void skb_set_owner_w(struct sk_buff *skb, struct sock *sk)
2524 {
2525 	skb_orphan(skb);
2526 	skb->sk = sk;
2527 #ifdef CONFIG_INET
2528 	if (unlikely(!sk_fullsock(sk))) {
2529 		skb->destructor = sock_edemux;
2530 		sock_hold(sk);
2531 		return;
2532 	}
2533 #endif
2534 	skb->destructor = sock_wfree;
2535 	skb_set_hash_from_sk(skb, sk);
2536 	/*
2537 	 * We used to take a refcount on sk, but following operation
2538 	 * is enough to guarantee sk_free() wont free this sock until
2539 	 * all in-flight packets are completed
2540 	 */
2541 	refcount_add(skb->truesize, &sk->sk_wmem_alloc);
2542 }
2543 EXPORT_SYMBOL(skb_set_owner_w);
2544 
2545 static bool can_skb_orphan_partial(const struct sk_buff *skb)
2546 {
2547 #ifdef CONFIG_TLS_DEVICE
2548 	/* Drivers depend on in-order delivery for crypto offload,
2549 	 * partial orphan breaks out-of-order-OK logic.
2550 	 */
2551 	if (skb->decrypted)
2552 		return false;
2553 #endif
2554 	return (skb->destructor == sock_wfree ||
2555 		(IS_ENABLED(CONFIG_INET) && skb->destructor == tcp_wfree));
2556 }
2557 
2558 /* This helper is used by netem, as it can hold packets in its
2559  * delay queue. We want to allow the owner socket to send more
2560  * packets, as if they were already TX completed by a typical driver.
2561  * But we also want to keep skb->sk set because some packet schedulers
2562  * rely on it (sch_fq for example).
2563  */
2564 void skb_orphan_partial(struct sk_buff *skb)
2565 {
2566 	if (skb_is_tcp_pure_ack(skb))
2567 		return;
2568 
2569 	if (can_skb_orphan_partial(skb) && skb_set_owner_sk_safe(skb, skb->sk))
2570 		return;
2571 
2572 	skb_orphan(skb);
2573 }
2574 EXPORT_SYMBOL(skb_orphan_partial);
2575 
2576 /*
2577  * Read buffer destructor automatically called from kfree_skb.
2578  */
2579 void sock_rfree(struct sk_buff *skb)
2580 {
2581 	struct sock *sk = skb->sk;
2582 	unsigned int len = skb->truesize;
2583 
2584 	atomic_sub(len, &sk->sk_rmem_alloc);
2585 	sk_mem_uncharge(sk, len);
2586 }
2587 EXPORT_SYMBOL(sock_rfree);
2588 
2589 /*
2590  * Buffer destructor for skbs that are not used directly in read or write
2591  * path, e.g. for error handler skbs. Automatically called from kfree_skb.
2592  */
2593 void sock_efree(struct sk_buff *skb)
2594 {
2595 	sock_put(skb->sk);
2596 }
2597 EXPORT_SYMBOL(sock_efree);
2598 
2599 /* Buffer destructor for prefetch/receive path where reference count may
2600  * not be held, e.g. for listen sockets.
2601  */
2602 #ifdef CONFIG_INET
2603 void sock_pfree(struct sk_buff *skb)
2604 {
2605 	if (sk_is_refcounted(skb->sk))
2606 		sock_gen_put(skb->sk);
2607 }
2608 EXPORT_SYMBOL(sock_pfree);
2609 #endif /* CONFIG_INET */
2610 
2611 kuid_t sock_i_uid(struct sock *sk)
2612 {
2613 	kuid_t uid;
2614 
2615 	read_lock_bh(&sk->sk_callback_lock);
2616 	uid = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_uid : GLOBAL_ROOT_UID;
2617 	read_unlock_bh(&sk->sk_callback_lock);
2618 	return uid;
2619 }
2620 EXPORT_SYMBOL(sock_i_uid);
2621 
2622 unsigned long __sock_i_ino(struct sock *sk)
2623 {
2624 	unsigned long ino;
2625 
2626 	read_lock(&sk->sk_callback_lock);
2627 	ino = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_ino : 0;
2628 	read_unlock(&sk->sk_callback_lock);
2629 	return ino;
2630 }
2631 EXPORT_SYMBOL(__sock_i_ino);
2632 
2633 unsigned long sock_i_ino(struct sock *sk)
2634 {
2635 	unsigned long ino;
2636 
2637 	local_bh_disable();
2638 	ino = __sock_i_ino(sk);
2639 	local_bh_enable();
2640 	return ino;
2641 }
2642 EXPORT_SYMBOL(sock_i_ino);
2643 
2644 /*
2645  * Allocate a skb from the socket's send buffer.
2646  */
2647 struct sk_buff *sock_wmalloc(struct sock *sk, unsigned long size, int force,
2648 			     gfp_t priority)
2649 {
2650 	if (force ||
2651 	    refcount_read(&sk->sk_wmem_alloc) < READ_ONCE(sk->sk_sndbuf)) {
2652 		struct sk_buff *skb = alloc_skb(size, priority);
2653 
2654 		if (skb) {
2655 			skb_set_owner_w(skb, sk);
2656 			return skb;
2657 		}
2658 	}
2659 	return NULL;
2660 }
2661 EXPORT_SYMBOL(sock_wmalloc);
2662 
2663 static void sock_ofree(struct sk_buff *skb)
2664 {
2665 	struct sock *sk = skb->sk;
2666 
2667 	atomic_sub(skb->truesize, &sk->sk_omem_alloc);
2668 }
2669 
2670 struct sk_buff *sock_omalloc(struct sock *sk, unsigned long size,
2671 			     gfp_t priority)
2672 {
2673 	struct sk_buff *skb;
2674 
2675 	/* small safe race: SKB_TRUESIZE may differ from final skb->truesize */
2676 	if (atomic_read(&sk->sk_omem_alloc) + SKB_TRUESIZE(size) >
2677 	    READ_ONCE(sysctl_optmem_max))
2678 		return NULL;
2679 
2680 	skb = alloc_skb(size, priority);
2681 	if (!skb)
2682 		return NULL;
2683 
2684 	atomic_add(skb->truesize, &sk->sk_omem_alloc);
2685 	skb->sk = sk;
2686 	skb->destructor = sock_ofree;
2687 	return skb;
2688 }
2689 
2690 /*
2691  * Allocate a memory block from the socket's option memory buffer.
2692  */
2693 void *sock_kmalloc(struct sock *sk, int size, gfp_t priority)
2694 {
2695 	int optmem_max = READ_ONCE(sysctl_optmem_max);
2696 
2697 	if ((unsigned int)size <= optmem_max &&
2698 	    atomic_read(&sk->sk_omem_alloc) + size < optmem_max) {
2699 		void *mem;
2700 		/* First do the add, to avoid the race if kmalloc
2701 		 * might sleep.
2702 		 */
2703 		atomic_add(size, &sk->sk_omem_alloc);
2704 		mem = kmalloc(size, priority);
2705 		if (mem)
2706 			return mem;
2707 		atomic_sub(size, &sk->sk_omem_alloc);
2708 	}
2709 	return NULL;
2710 }
2711 EXPORT_SYMBOL(sock_kmalloc);
2712 
2713 /* Free an option memory block. Note, we actually want the inline
2714  * here as this allows gcc to detect the nullify and fold away the
2715  * condition entirely.
2716  */
2717 static inline void __sock_kfree_s(struct sock *sk, void *mem, int size,
2718 				  const bool nullify)
2719 {
2720 	if (WARN_ON_ONCE(!mem))
2721 		return;
2722 	if (nullify)
2723 		kfree_sensitive(mem);
2724 	else
2725 		kfree(mem);
2726 	atomic_sub(size, &sk->sk_omem_alloc);
2727 }
2728 
2729 void sock_kfree_s(struct sock *sk, void *mem, int size)
2730 {
2731 	__sock_kfree_s(sk, mem, size, false);
2732 }
2733 EXPORT_SYMBOL(sock_kfree_s);
2734 
2735 void sock_kzfree_s(struct sock *sk, void *mem, int size)
2736 {
2737 	__sock_kfree_s(sk, mem, size, true);
2738 }
2739 EXPORT_SYMBOL(sock_kzfree_s);
2740 
2741 /* It is almost wait_for_tcp_memory minus release_sock/lock_sock.
2742    I think, these locks should be removed for datagram sockets.
2743  */
2744 static long sock_wait_for_wmem(struct sock *sk, long timeo)
2745 {
2746 	DEFINE_WAIT(wait);
2747 
2748 	sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
2749 	for (;;) {
2750 		if (!timeo)
2751 			break;
2752 		if (signal_pending(current))
2753 			break;
2754 		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
2755 		prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
2756 		if (refcount_read(&sk->sk_wmem_alloc) < READ_ONCE(sk->sk_sndbuf))
2757 			break;
2758 		if (READ_ONCE(sk->sk_shutdown) & SEND_SHUTDOWN)
2759 			break;
2760 		if (READ_ONCE(sk->sk_err))
2761 			break;
2762 		timeo = schedule_timeout(timeo);
2763 	}
2764 	finish_wait(sk_sleep(sk), &wait);
2765 	return timeo;
2766 }
2767 
2768 
2769 /*
2770  *	Generic send/receive buffer handlers
2771  */
2772 
2773 struct sk_buff *sock_alloc_send_pskb(struct sock *sk, unsigned long header_len,
2774 				     unsigned long data_len, int noblock,
2775 				     int *errcode, int max_page_order)
2776 {
2777 	struct sk_buff *skb;
2778 	long timeo;
2779 	int err;
2780 
2781 	timeo = sock_sndtimeo(sk, noblock);
2782 	for (;;) {
2783 		err = sock_error(sk);
2784 		if (err != 0)
2785 			goto failure;
2786 
2787 		err = -EPIPE;
2788 		if (READ_ONCE(sk->sk_shutdown) & SEND_SHUTDOWN)
2789 			goto failure;
2790 
2791 		if (sk_wmem_alloc_get(sk) < READ_ONCE(sk->sk_sndbuf))
2792 			break;
2793 
2794 		sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
2795 		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
2796 		err = -EAGAIN;
2797 		if (!timeo)
2798 			goto failure;
2799 		if (signal_pending(current))
2800 			goto interrupted;
2801 		timeo = sock_wait_for_wmem(sk, timeo);
2802 	}
2803 	skb = alloc_skb_with_frags(header_len, data_len, max_page_order,
2804 				   errcode, sk->sk_allocation);
2805 	if (skb)
2806 		skb_set_owner_w(skb, sk);
2807 	return skb;
2808 
2809 interrupted:
2810 	err = sock_intr_errno(timeo);
2811 failure:
2812 	*errcode = err;
2813 	return NULL;
2814 }
2815 EXPORT_SYMBOL(sock_alloc_send_pskb);
2816 
2817 int __sock_cmsg_send(struct sock *sk, struct cmsghdr *cmsg,
2818 		     struct sockcm_cookie *sockc)
2819 {
2820 	u32 tsflags;
2821 
2822 	switch (cmsg->cmsg_type) {
2823 	case SO_MARK:
2824 		if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_RAW) &&
2825 		    !ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
2826 			return -EPERM;
2827 		if (cmsg->cmsg_len != CMSG_LEN(sizeof(u32)))
2828 			return -EINVAL;
2829 		sockc->mark = *(u32 *)CMSG_DATA(cmsg);
2830 		break;
2831 	case SO_TIMESTAMPING_OLD:
2832 	case SO_TIMESTAMPING_NEW:
2833 		if (cmsg->cmsg_len != CMSG_LEN(sizeof(u32)))
2834 			return -EINVAL;
2835 
2836 		tsflags = *(u32 *)CMSG_DATA(cmsg);
2837 		if (tsflags & ~SOF_TIMESTAMPING_TX_RECORD_MASK)
2838 			return -EINVAL;
2839 
2840 		sockc->tsflags &= ~SOF_TIMESTAMPING_TX_RECORD_MASK;
2841 		sockc->tsflags |= tsflags;
2842 		break;
2843 	case SCM_TXTIME:
2844 		if (!sock_flag(sk, SOCK_TXTIME))
2845 			return -EINVAL;
2846 		if (cmsg->cmsg_len != CMSG_LEN(sizeof(u64)))
2847 			return -EINVAL;
2848 		sockc->transmit_time = get_unaligned((u64 *)CMSG_DATA(cmsg));
2849 		break;
2850 	/* SCM_RIGHTS and SCM_CREDENTIALS are semantically in SOL_UNIX. */
2851 	case SCM_RIGHTS:
2852 	case SCM_CREDENTIALS:
2853 		break;
2854 	default:
2855 		return -EINVAL;
2856 	}
2857 	return 0;
2858 }
2859 EXPORT_SYMBOL(__sock_cmsg_send);
2860 
2861 int sock_cmsg_send(struct sock *sk, struct msghdr *msg,
2862 		   struct sockcm_cookie *sockc)
2863 {
2864 	struct cmsghdr *cmsg;
2865 	int ret;
2866 
2867 	for_each_cmsghdr(cmsg, msg) {
2868 		if (!CMSG_OK(msg, cmsg))
2869 			return -EINVAL;
2870 		if (cmsg->cmsg_level != SOL_SOCKET)
2871 			continue;
2872 		ret = __sock_cmsg_send(sk, cmsg, sockc);
2873 		if (ret)
2874 			return ret;
2875 	}
2876 	return 0;
2877 }
2878 EXPORT_SYMBOL(sock_cmsg_send);
2879 
2880 static void sk_enter_memory_pressure(struct sock *sk)
2881 {
2882 	if (!sk->sk_prot->enter_memory_pressure)
2883 		return;
2884 
2885 	sk->sk_prot->enter_memory_pressure(sk);
2886 }
2887 
2888 static void sk_leave_memory_pressure(struct sock *sk)
2889 {
2890 	if (sk->sk_prot->leave_memory_pressure) {
2891 		INDIRECT_CALL_INET_1(sk->sk_prot->leave_memory_pressure,
2892 				     tcp_leave_memory_pressure, sk);
2893 	} else {
2894 		unsigned long *memory_pressure = sk->sk_prot->memory_pressure;
2895 
2896 		if (memory_pressure && READ_ONCE(*memory_pressure))
2897 			WRITE_ONCE(*memory_pressure, 0);
2898 	}
2899 }
2900 
2901 DEFINE_STATIC_KEY_FALSE(net_high_order_alloc_disable_key);
2902 
2903 /**
2904  * skb_page_frag_refill - check that a page_frag contains enough room
2905  * @sz: minimum size of the fragment we want to get
2906  * @pfrag: pointer to page_frag
2907  * @gfp: priority for memory allocation
2908  *
2909  * Note: While this allocator tries to use high order pages, there is
2910  * no guarantee that allocations succeed. Therefore, @sz MUST be
2911  * less or equal than PAGE_SIZE.
2912  */
2913 bool skb_page_frag_refill(unsigned int sz, struct page_frag *pfrag, gfp_t gfp)
2914 {
2915 	if (pfrag->page) {
2916 		if (page_ref_count(pfrag->page) == 1) {
2917 			pfrag->offset = 0;
2918 			return true;
2919 		}
2920 		if (pfrag->offset + sz <= pfrag->size)
2921 			return true;
2922 		put_page(pfrag->page);
2923 	}
2924 
2925 	pfrag->offset = 0;
2926 	if (SKB_FRAG_PAGE_ORDER &&
2927 	    !static_branch_unlikely(&net_high_order_alloc_disable_key)) {
2928 		/* Avoid direct reclaim but allow kswapd to wake */
2929 		pfrag->page = alloc_pages((gfp & ~__GFP_DIRECT_RECLAIM) |
2930 					  __GFP_COMP | __GFP_NOWARN |
2931 					  __GFP_NORETRY,
2932 					  SKB_FRAG_PAGE_ORDER);
2933 		if (likely(pfrag->page)) {
2934 			pfrag->size = PAGE_SIZE << SKB_FRAG_PAGE_ORDER;
2935 			return true;
2936 		}
2937 	}
2938 	pfrag->page = alloc_page(gfp);
2939 	if (likely(pfrag->page)) {
2940 		pfrag->size = PAGE_SIZE;
2941 		return true;
2942 	}
2943 	return false;
2944 }
2945 EXPORT_SYMBOL(skb_page_frag_refill);
2946 
2947 bool sk_page_frag_refill(struct sock *sk, struct page_frag *pfrag)
2948 {
2949 	if (likely(skb_page_frag_refill(32U, pfrag, sk->sk_allocation)))
2950 		return true;
2951 
2952 	sk_enter_memory_pressure(sk);
2953 	sk_stream_moderate_sndbuf(sk);
2954 	return false;
2955 }
2956 EXPORT_SYMBOL(sk_page_frag_refill);
2957 
2958 void __lock_sock(struct sock *sk)
2959 	__releases(&sk->sk_lock.slock)
2960 	__acquires(&sk->sk_lock.slock)
2961 {
2962 	DEFINE_WAIT(wait);
2963 
2964 	for (;;) {
2965 		prepare_to_wait_exclusive(&sk->sk_lock.wq, &wait,
2966 					TASK_UNINTERRUPTIBLE);
2967 		spin_unlock_bh(&sk->sk_lock.slock);
2968 		schedule();
2969 		spin_lock_bh(&sk->sk_lock.slock);
2970 		if (!sock_owned_by_user(sk))
2971 			break;
2972 	}
2973 	finish_wait(&sk->sk_lock.wq, &wait);
2974 }
2975 
2976 void __release_sock(struct sock *sk)
2977 	__releases(&sk->sk_lock.slock)
2978 	__acquires(&sk->sk_lock.slock)
2979 {
2980 	struct sk_buff *skb, *next;
2981 
2982 	while ((skb = sk->sk_backlog.head) != NULL) {
2983 		sk->sk_backlog.head = sk->sk_backlog.tail = NULL;
2984 
2985 		spin_unlock_bh(&sk->sk_lock.slock);
2986 
2987 		do {
2988 			next = skb->next;
2989 			prefetch(next);
2990 			DEBUG_NET_WARN_ON_ONCE(skb_dst_is_noref(skb));
2991 			skb_mark_not_on_list(skb);
2992 			sk_backlog_rcv(sk, skb);
2993 
2994 			cond_resched();
2995 
2996 			skb = next;
2997 		} while (skb != NULL);
2998 
2999 		spin_lock_bh(&sk->sk_lock.slock);
3000 	}
3001 
3002 	/*
3003 	 * Doing the zeroing here guarantee we can not loop forever
3004 	 * while a wild producer attempts to flood us.
3005 	 */
3006 	sk->sk_backlog.len = 0;
3007 }
3008 
3009 void __sk_flush_backlog(struct sock *sk)
3010 {
3011 	spin_lock_bh(&sk->sk_lock.slock);
3012 	__release_sock(sk);
3013 	spin_unlock_bh(&sk->sk_lock.slock);
3014 }
3015 EXPORT_SYMBOL_GPL(__sk_flush_backlog);
3016 
3017 /**
3018  * sk_wait_data - wait for data to arrive at sk_receive_queue
3019  * @sk:    sock to wait on
3020  * @timeo: for how long
3021  * @skb:   last skb seen on sk_receive_queue
3022  *
3023  * Now socket state including sk->sk_err is changed only under lock,
3024  * hence we may omit checks after joining wait queue.
3025  * We check receive queue before schedule() only as optimization;
3026  * it is very likely that release_sock() added new data.
3027  */
3028 int sk_wait_data(struct sock *sk, long *timeo, const struct sk_buff *skb)
3029 {
3030 	DEFINE_WAIT_FUNC(wait, woken_wake_function);
3031 	int rc;
3032 
3033 	add_wait_queue(sk_sleep(sk), &wait);
3034 	sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
3035 	rc = sk_wait_event(sk, timeo, skb_peek_tail(&sk->sk_receive_queue) != skb, &wait);
3036 	sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
3037 	remove_wait_queue(sk_sleep(sk), &wait);
3038 	return rc;
3039 }
3040 EXPORT_SYMBOL(sk_wait_data);
3041 
3042 /**
3043  *	__sk_mem_raise_allocated - increase memory_allocated
3044  *	@sk: socket
3045  *	@size: memory size to allocate
3046  *	@amt: pages to allocate
3047  *	@kind: allocation type
3048  *
3049  *	Similar to __sk_mem_schedule(), but does not update sk_forward_alloc
3050  */
3051 int __sk_mem_raise_allocated(struct sock *sk, int size, int amt, int kind)
3052 {
3053 	bool memcg_charge = mem_cgroup_sockets_enabled && sk->sk_memcg;
3054 	struct proto *prot = sk->sk_prot;
3055 	bool charged = true;
3056 	long allocated;
3057 
3058 	sk_memory_allocated_add(sk, amt);
3059 	allocated = sk_memory_allocated(sk);
3060 	if (memcg_charge &&
3061 	    !(charged = mem_cgroup_charge_skmem(sk->sk_memcg, amt,
3062 						gfp_memcg_charge())))
3063 		goto suppress_allocation;
3064 
3065 	/* Under limit. */
3066 	if (allocated <= sk_prot_mem_limits(sk, 0)) {
3067 		sk_leave_memory_pressure(sk);
3068 		return 1;
3069 	}
3070 
3071 	/* Under pressure. */
3072 	if (allocated > sk_prot_mem_limits(sk, 1))
3073 		sk_enter_memory_pressure(sk);
3074 
3075 	/* Over hard limit. */
3076 	if (allocated > sk_prot_mem_limits(sk, 2))
3077 		goto suppress_allocation;
3078 
3079 	/* guarantee minimum buffer size under pressure */
3080 	if (kind == SK_MEM_RECV) {
3081 		if (atomic_read(&sk->sk_rmem_alloc) < sk_get_rmem0(sk, prot))
3082 			return 1;
3083 
3084 	} else { /* SK_MEM_SEND */
3085 		int wmem0 = sk_get_wmem0(sk, prot);
3086 
3087 		if (sk->sk_type == SOCK_STREAM) {
3088 			if (sk->sk_wmem_queued < wmem0)
3089 				return 1;
3090 		} else if (refcount_read(&sk->sk_wmem_alloc) < wmem0) {
3091 				return 1;
3092 		}
3093 	}
3094 
3095 	if (sk_has_memory_pressure(sk)) {
3096 		u64 alloc;
3097 
3098 		if (!sk_under_memory_pressure(sk))
3099 			return 1;
3100 		alloc = sk_sockets_allocated_read_positive(sk);
3101 		if (sk_prot_mem_limits(sk, 2) > alloc *
3102 		    sk_mem_pages(sk->sk_wmem_queued +
3103 				 atomic_read(&sk->sk_rmem_alloc) +
3104 				 sk->sk_forward_alloc))
3105 			return 1;
3106 	}
3107 
3108 suppress_allocation:
3109 
3110 	if (kind == SK_MEM_SEND && sk->sk_type == SOCK_STREAM) {
3111 		sk_stream_moderate_sndbuf(sk);
3112 
3113 		/* Fail only if socket is _under_ its sndbuf.
3114 		 * In this case we cannot block, so that we have to fail.
3115 		 */
3116 		if (sk->sk_wmem_queued + size >= sk->sk_sndbuf) {
3117 			/* Force charge with __GFP_NOFAIL */
3118 			if (memcg_charge && !charged) {
3119 				mem_cgroup_charge_skmem(sk->sk_memcg, amt,
3120 					gfp_memcg_charge() | __GFP_NOFAIL);
3121 			}
3122 			return 1;
3123 		}
3124 	}
3125 
3126 	if (kind == SK_MEM_SEND || (kind == SK_MEM_RECV && charged))
3127 		trace_sock_exceed_buf_limit(sk, prot, allocated, kind);
3128 
3129 	sk_memory_allocated_sub(sk, amt);
3130 
3131 	if (memcg_charge && charged)
3132 		mem_cgroup_uncharge_skmem(sk->sk_memcg, amt);
3133 
3134 	return 0;
3135 }
3136 
3137 /**
3138  *	__sk_mem_schedule - increase sk_forward_alloc and memory_allocated
3139  *	@sk: socket
3140  *	@size: memory size to allocate
3141  *	@kind: allocation type
3142  *
3143  *	If kind is SK_MEM_SEND, it means wmem allocation. Otherwise it means
3144  *	rmem allocation. This function assumes that protocols which have
3145  *	memory_pressure use sk_wmem_queued as write buffer accounting.
3146  */
3147 int __sk_mem_schedule(struct sock *sk, int size, int kind)
3148 {
3149 	int ret, amt = sk_mem_pages(size);
3150 
3151 	sk_forward_alloc_add(sk, amt << PAGE_SHIFT);
3152 	ret = __sk_mem_raise_allocated(sk, size, amt, kind);
3153 	if (!ret)
3154 		sk_forward_alloc_add(sk, -(amt << PAGE_SHIFT));
3155 	return ret;
3156 }
3157 EXPORT_SYMBOL(__sk_mem_schedule);
3158 
3159 /**
3160  *	__sk_mem_reduce_allocated - reclaim memory_allocated
3161  *	@sk: socket
3162  *	@amount: number of quanta
3163  *
3164  *	Similar to __sk_mem_reclaim(), but does not update sk_forward_alloc
3165  */
3166 void __sk_mem_reduce_allocated(struct sock *sk, int amount)
3167 {
3168 	sk_memory_allocated_sub(sk, amount);
3169 
3170 	if (mem_cgroup_sockets_enabled && sk->sk_memcg)
3171 		mem_cgroup_uncharge_skmem(sk->sk_memcg, amount);
3172 
3173 	if (sk_under_global_memory_pressure(sk) &&
3174 	    (sk_memory_allocated(sk) < sk_prot_mem_limits(sk, 0)))
3175 		sk_leave_memory_pressure(sk);
3176 }
3177 
3178 /**
3179  *	__sk_mem_reclaim - reclaim sk_forward_alloc and memory_allocated
3180  *	@sk: socket
3181  *	@amount: number of bytes (rounded down to a PAGE_SIZE multiple)
3182  */
3183 void __sk_mem_reclaim(struct sock *sk, int amount)
3184 {
3185 	amount >>= PAGE_SHIFT;
3186 	sk_forward_alloc_add(sk, -(amount << PAGE_SHIFT));
3187 	__sk_mem_reduce_allocated(sk, amount);
3188 }
3189 EXPORT_SYMBOL(__sk_mem_reclaim);
3190 
3191 int sk_set_peek_off(struct sock *sk, int val)
3192 {
3193 	WRITE_ONCE(sk->sk_peek_off, val);
3194 	return 0;
3195 }
3196 EXPORT_SYMBOL_GPL(sk_set_peek_off);
3197 
3198 /*
3199  * Set of default routines for initialising struct proto_ops when
3200  * the protocol does not support a particular function. In certain
3201  * cases where it makes no sense for a protocol to have a "do nothing"
3202  * function, some default processing is provided.
3203  */
3204 
3205 int sock_no_bind(struct socket *sock, struct sockaddr *saddr, int len)
3206 {
3207 	return -EOPNOTSUPP;
3208 }
3209 EXPORT_SYMBOL(sock_no_bind);
3210 
3211 int sock_no_connect(struct socket *sock, struct sockaddr *saddr,
3212 		    int len, int flags)
3213 {
3214 	return -EOPNOTSUPP;
3215 }
3216 EXPORT_SYMBOL(sock_no_connect);
3217 
3218 int sock_no_socketpair(struct socket *sock1, struct socket *sock2)
3219 {
3220 	return -EOPNOTSUPP;
3221 }
3222 EXPORT_SYMBOL(sock_no_socketpair);
3223 
3224 int sock_no_accept(struct socket *sock, struct socket *newsock, int flags,
3225 		   bool kern)
3226 {
3227 	return -EOPNOTSUPP;
3228 }
3229 EXPORT_SYMBOL(sock_no_accept);
3230 
3231 int sock_no_getname(struct socket *sock, struct sockaddr *saddr,
3232 		    int peer)
3233 {
3234 	return -EOPNOTSUPP;
3235 }
3236 EXPORT_SYMBOL(sock_no_getname);
3237 
3238 int sock_no_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
3239 {
3240 	return -EOPNOTSUPP;
3241 }
3242 EXPORT_SYMBOL(sock_no_ioctl);
3243 
3244 int sock_no_listen(struct socket *sock, int backlog)
3245 {
3246 	return -EOPNOTSUPP;
3247 }
3248 EXPORT_SYMBOL(sock_no_listen);
3249 
3250 int sock_no_shutdown(struct socket *sock, int how)
3251 {
3252 	return -EOPNOTSUPP;
3253 }
3254 EXPORT_SYMBOL(sock_no_shutdown);
3255 
3256 int sock_no_sendmsg(struct socket *sock, struct msghdr *m, size_t len)
3257 {
3258 	return -EOPNOTSUPP;
3259 }
3260 EXPORT_SYMBOL(sock_no_sendmsg);
3261 
3262 int sock_no_sendmsg_locked(struct sock *sk, struct msghdr *m, size_t len)
3263 {
3264 	return -EOPNOTSUPP;
3265 }
3266 EXPORT_SYMBOL(sock_no_sendmsg_locked);
3267 
3268 int sock_no_recvmsg(struct socket *sock, struct msghdr *m, size_t len,
3269 		    int flags)
3270 {
3271 	return -EOPNOTSUPP;
3272 }
3273 EXPORT_SYMBOL(sock_no_recvmsg);
3274 
3275 int sock_no_mmap(struct file *file, struct socket *sock, struct vm_area_struct *vma)
3276 {
3277 	/* Mirror missing mmap method error code */
3278 	return -ENODEV;
3279 }
3280 EXPORT_SYMBOL(sock_no_mmap);
3281 
3282 /*
3283  * When a file is received (via SCM_RIGHTS, etc), we must bump the
3284  * various sock-based usage counts.
3285  */
3286 void __receive_sock(struct file *file)
3287 {
3288 	struct socket *sock;
3289 
3290 	sock = sock_from_file(file);
3291 	if (sock) {
3292 		sock_update_netprioidx(&sock->sk->sk_cgrp_data);
3293 		sock_update_classid(&sock->sk->sk_cgrp_data);
3294 	}
3295 }
3296 
3297 /*
3298  *	Default Socket Callbacks
3299  */
3300 
3301 static void sock_def_wakeup(struct sock *sk)
3302 {
3303 	struct socket_wq *wq;
3304 
3305 	rcu_read_lock();
3306 	wq = rcu_dereference(sk->sk_wq);
3307 	if (skwq_has_sleeper(wq))
3308 		wake_up_interruptible_all(&wq->wait);
3309 	rcu_read_unlock();
3310 }
3311 
3312 static void sock_def_error_report(struct sock *sk)
3313 {
3314 	struct socket_wq *wq;
3315 
3316 	rcu_read_lock();
3317 	wq = rcu_dereference(sk->sk_wq);
3318 	if (skwq_has_sleeper(wq))
3319 		wake_up_interruptible_poll(&wq->wait, EPOLLERR);
3320 	sk_wake_async(sk, SOCK_WAKE_IO, POLL_ERR);
3321 	rcu_read_unlock();
3322 }
3323 
3324 void sock_def_readable(struct sock *sk)
3325 {
3326 	struct socket_wq *wq;
3327 
3328 	trace_sk_data_ready(sk);
3329 
3330 	rcu_read_lock();
3331 	wq = rcu_dereference(sk->sk_wq);
3332 	if (skwq_has_sleeper(wq))
3333 		wake_up_interruptible_sync_poll(&wq->wait, EPOLLIN | EPOLLPRI |
3334 						EPOLLRDNORM | EPOLLRDBAND);
3335 	sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
3336 	rcu_read_unlock();
3337 }
3338 
3339 static void sock_def_write_space(struct sock *sk)
3340 {
3341 	struct socket_wq *wq;
3342 
3343 	rcu_read_lock();
3344 
3345 	/* Do not wake up a writer until he can make "significant"
3346 	 * progress.  --DaveM
3347 	 */
3348 	if (sock_writeable(sk)) {
3349 		wq = rcu_dereference(sk->sk_wq);
3350 		if (skwq_has_sleeper(wq))
3351 			wake_up_interruptible_sync_poll(&wq->wait, EPOLLOUT |
3352 						EPOLLWRNORM | EPOLLWRBAND);
3353 
3354 		/* Should agree with poll, otherwise some programs break */
3355 		sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
3356 	}
3357 
3358 	rcu_read_unlock();
3359 }
3360 
3361 /* An optimised version of sock_def_write_space(), should only be called
3362  * for SOCK_RCU_FREE sockets under RCU read section and after putting
3363  * ->sk_wmem_alloc.
3364  */
3365 static void sock_def_write_space_wfree(struct sock *sk)
3366 {
3367 	/* Do not wake up a writer until he can make "significant"
3368 	 * progress.  --DaveM
3369 	 */
3370 	if (sock_writeable(sk)) {
3371 		struct socket_wq *wq = rcu_dereference(sk->sk_wq);
3372 
3373 		/* rely on refcount_sub from sock_wfree() */
3374 		smp_mb__after_atomic();
3375 		if (wq && waitqueue_active(&wq->wait))
3376 			wake_up_interruptible_sync_poll(&wq->wait, EPOLLOUT |
3377 						EPOLLWRNORM | EPOLLWRBAND);
3378 
3379 		/* Should agree with poll, otherwise some programs break */
3380 		sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
3381 	}
3382 }
3383 
3384 static void sock_def_destruct(struct sock *sk)
3385 {
3386 }
3387 
3388 void sk_send_sigurg(struct sock *sk)
3389 {
3390 	if (sk->sk_socket && sk->sk_socket->file)
3391 		if (send_sigurg(&sk->sk_socket->file->f_owner))
3392 			sk_wake_async(sk, SOCK_WAKE_URG, POLL_PRI);
3393 }
3394 EXPORT_SYMBOL(sk_send_sigurg);
3395 
3396 void sk_reset_timer(struct sock *sk, struct timer_list* timer,
3397 		    unsigned long expires)
3398 {
3399 	if (!mod_timer(timer, expires))
3400 		sock_hold(sk);
3401 }
3402 EXPORT_SYMBOL(sk_reset_timer);
3403 
3404 void sk_stop_timer(struct sock *sk, struct timer_list* timer)
3405 {
3406 	if (del_timer(timer))
3407 		__sock_put(sk);
3408 }
3409 EXPORT_SYMBOL(sk_stop_timer);
3410 
3411 void sk_stop_timer_sync(struct sock *sk, struct timer_list *timer)
3412 {
3413 	if (del_timer_sync(timer))
3414 		__sock_put(sk);
3415 }
3416 EXPORT_SYMBOL(sk_stop_timer_sync);
3417 
3418 void sock_init_data_uid(struct socket *sock, struct sock *sk, kuid_t uid)
3419 {
3420 	sk_init_common(sk);
3421 	sk->sk_send_head	=	NULL;
3422 
3423 	timer_setup(&sk->sk_timer, NULL, 0);
3424 
3425 	sk->sk_allocation	=	GFP_KERNEL;
3426 	sk->sk_rcvbuf		=	READ_ONCE(sysctl_rmem_default);
3427 	sk->sk_sndbuf		=	READ_ONCE(sysctl_wmem_default);
3428 	sk->sk_state		=	TCP_CLOSE;
3429 	sk->sk_use_task_frag	=	true;
3430 	sk_set_socket(sk, sock);
3431 
3432 	sock_set_flag(sk, SOCK_ZAPPED);
3433 
3434 	if (sock) {
3435 		sk->sk_type	=	sock->type;
3436 		RCU_INIT_POINTER(sk->sk_wq, &sock->wq);
3437 		sock->sk	=	sk;
3438 	} else {
3439 		RCU_INIT_POINTER(sk->sk_wq, NULL);
3440 	}
3441 	sk->sk_uid	=	uid;
3442 
3443 	rwlock_init(&sk->sk_callback_lock);
3444 	if (sk->sk_kern_sock)
3445 		lockdep_set_class_and_name(
3446 			&sk->sk_callback_lock,
3447 			af_kern_callback_keys + sk->sk_family,
3448 			af_family_kern_clock_key_strings[sk->sk_family]);
3449 	else
3450 		lockdep_set_class_and_name(
3451 			&sk->sk_callback_lock,
3452 			af_callback_keys + sk->sk_family,
3453 			af_family_clock_key_strings[sk->sk_family]);
3454 
3455 	sk->sk_state_change	=	sock_def_wakeup;
3456 	sk->sk_data_ready	=	sock_def_readable;
3457 	sk->sk_write_space	=	sock_def_write_space;
3458 	sk->sk_error_report	=	sock_def_error_report;
3459 	sk->sk_destruct		=	sock_def_destruct;
3460 
3461 	sk->sk_frag.page	=	NULL;
3462 	sk->sk_frag.offset	=	0;
3463 	sk->sk_peek_off		=	-1;
3464 
3465 	sk->sk_peer_pid 	=	NULL;
3466 	sk->sk_peer_cred	=	NULL;
3467 	spin_lock_init(&sk->sk_peer_lock);
3468 
3469 	sk->sk_write_pending	=	0;
3470 	sk->sk_rcvlowat		=	1;
3471 	sk->sk_rcvtimeo		=	MAX_SCHEDULE_TIMEOUT;
3472 	sk->sk_sndtimeo		=	MAX_SCHEDULE_TIMEOUT;
3473 
3474 	sk->sk_stamp = SK_DEFAULT_STAMP;
3475 #if BITS_PER_LONG==32
3476 	seqlock_init(&sk->sk_stamp_seq);
3477 #endif
3478 	atomic_set(&sk->sk_zckey, 0);
3479 
3480 #ifdef CONFIG_NET_RX_BUSY_POLL
3481 	sk->sk_napi_id		=	0;
3482 	sk->sk_ll_usec		=	READ_ONCE(sysctl_net_busy_read);
3483 #endif
3484 
3485 	sk->sk_max_pacing_rate = ~0UL;
3486 	sk->sk_pacing_rate = ~0UL;
3487 	WRITE_ONCE(sk->sk_pacing_shift, 10);
3488 	sk->sk_incoming_cpu = -1;
3489 
3490 	sk_rx_queue_clear(sk);
3491 	/*
3492 	 * Before updating sk_refcnt, we must commit prior changes to memory
3493 	 * (Documentation/RCU/rculist_nulls.rst for details)
3494 	 */
3495 	smp_wmb();
3496 	refcount_set(&sk->sk_refcnt, 1);
3497 	atomic_set(&sk->sk_drops, 0);
3498 }
3499 EXPORT_SYMBOL(sock_init_data_uid);
3500 
3501 void sock_init_data(struct socket *sock, struct sock *sk)
3502 {
3503 	kuid_t uid = sock ?
3504 		SOCK_INODE(sock)->i_uid :
3505 		make_kuid(sock_net(sk)->user_ns, 0);
3506 
3507 	sock_init_data_uid(sock, sk, uid);
3508 }
3509 EXPORT_SYMBOL(sock_init_data);
3510 
3511 void lock_sock_nested(struct sock *sk, int subclass)
3512 {
3513 	/* The sk_lock has mutex_lock() semantics here. */
3514 	mutex_acquire(&sk->sk_lock.dep_map, subclass, 0, _RET_IP_);
3515 
3516 	might_sleep();
3517 	spin_lock_bh(&sk->sk_lock.slock);
3518 	if (sock_owned_by_user_nocheck(sk))
3519 		__lock_sock(sk);
3520 	sk->sk_lock.owned = 1;
3521 	spin_unlock_bh(&sk->sk_lock.slock);
3522 }
3523 EXPORT_SYMBOL(lock_sock_nested);
3524 
3525 void release_sock(struct sock *sk)
3526 {
3527 	spin_lock_bh(&sk->sk_lock.slock);
3528 	if (sk->sk_backlog.tail)
3529 		__release_sock(sk);
3530 
3531 	/* Warning : release_cb() might need to release sk ownership,
3532 	 * ie call sock_release_ownership(sk) before us.
3533 	 */
3534 	if (sk->sk_prot->release_cb)
3535 		sk->sk_prot->release_cb(sk);
3536 
3537 	sock_release_ownership(sk);
3538 	if (waitqueue_active(&sk->sk_lock.wq))
3539 		wake_up(&sk->sk_lock.wq);
3540 	spin_unlock_bh(&sk->sk_lock.slock);
3541 }
3542 EXPORT_SYMBOL(release_sock);
3543 
3544 bool __lock_sock_fast(struct sock *sk) __acquires(&sk->sk_lock.slock)
3545 {
3546 	might_sleep();
3547 	spin_lock_bh(&sk->sk_lock.slock);
3548 
3549 	if (!sock_owned_by_user_nocheck(sk)) {
3550 		/*
3551 		 * Fast path return with bottom halves disabled and
3552 		 * sock::sk_lock.slock held.
3553 		 *
3554 		 * The 'mutex' is not contended and holding
3555 		 * sock::sk_lock.slock prevents all other lockers to
3556 		 * proceed so the corresponding unlock_sock_fast() can
3557 		 * avoid the slow path of release_sock() completely and
3558 		 * just release slock.
3559 		 *
3560 		 * From a semantical POV this is equivalent to 'acquiring'
3561 		 * the 'mutex', hence the corresponding lockdep
3562 		 * mutex_release() has to happen in the fast path of
3563 		 * unlock_sock_fast().
3564 		 */
3565 		return false;
3566 	}
3567 
3568 	__lock_sock(sk);
3569 	sk->sk_lock.owned = 1;
3570 	__acquire(&sk->sk_lock.slock);
3571 	spin_unlock_bh(&sk->sk_lock.slock);
3572 	return true;
3573 }
3574 EXPORT_SYMBOL(__lock_sock_fast);
3575 
3576 int sock_gettstamp(struct socket *sock, void __user *userstamp,
3577 		   bool timeval, bool time32)
3578 {
3579 	struct sock *sk = sock->sk;
3580 	struct timespec64 ts;
3581 
3582 	sock_enable_timestamp(sk, SOCK_TIMESTAMP);
3583 	ts = ktime_to_timespec64(sock_read_timestamp(sk));
3584 	if (ts.tv_sec == -1)
3585 		return -ENOENT;
3586 	if (ts.tv_sec == 0) {
3587 		ktime_t kt = ktime_get_real();
3588 		sock_write_timestamp(sk, kt);
3589 		ts = ktime_to_timespec64(kt);
3590 	}
3591 
3592 	if (timeval)
3593 		ts.tv_nsec /= 1000;
3594 
3595 #ifdef CONFIG_COMPAT_32BIT_TIME
3596 	if (time32)
3597 		return put_old_timespec32(&ts, userstamp);
3598 #endif
3599 #ifdef CONFIG_SPARC64
3600 	/* beware of padding in sparc64 timeval */
3601 	if (timeval && !in_compat_syscall()) {
3602 		struct __kernel_old_timeval __user tv = {
3603 			.tv_sec = ts.tv_sec,
3604 			.tv_usec = ts.tv_nsec,
3605 		};
3606 		if (copy_to_user(userstamp, &tv, sizeof(tv)))
3607 			return -EFAULT;
3608 		return 0;
3609 	}
3610 #endif
3611 	return put_timespec64(&ts, userstamp);
3612 }
3613 EXPORT_SYMBOL(sock_gettstamp);
3614 
3615 void sock_enable_timestamp(struct sock *sk, enum sock_flags flag)
3616 {
3617 	if (!sock_flag(sk, flag)) {
3618 		unsigned long previous_flags = sk->sk_flags;
3619 
3620 		sock_set_flag(sk, flag);
3621 		/*
3622 		 * we just set one of the two flags which require net
3623 		 * time stamping, but time stamping might have been on
3624 		 * already because of the other one
3625 		 */
3626 		if (sock_needs_netstamp(sk) &&
3627 		    !(previous_flags & SK_FLAGS_TIMESTAMP))
3628 			net_enable_timestamp();
3629 	}
3630 }
3631 
3632 int sock_recv_errqueue(struct sock *sk, struct msghdr *msg, int len,
3633 		       int level, int type)
3634 {
3635 	struct sock_exterr_skb *serr;
3636 	struct sk_buff *skb;
3637 	int copied, err;
3638 
3639 	err = -EAGAIN;
3640 	skb = sock_dequeue_err_skb(sk);
3641 	if (skb == NULL)
3642 		goto out;
3643 
3644 	copied = skb->len;
3645 	if (copied > len) {
3646 		msg->msg_flags |= MSG_TRUNC;
3647 		copied = len;
3648 	}
3649 	err = skb_copy_datagram_msg(skb, 0, msg, copied);
3650 	if (err)
3651 		goto out_free_skb;
3652 
3653 	sock_recv_timestamp(msg, sk, skb);
3654 
3655 	serr = SKB_EXT_ERR(skb);
3656 	put_cmsg(msg, level, type, sizeof(serr->ee), &serr->ee);
3657 
3658 	msg->msg_flags |= MSG_ERRQUEUE;
3659 	err = copied;
3660 
3661 out_free_skb:
3662 	kfree_skb(skb);
3663 out:
3664 	return err;
3665 }
3666 EXPORT_SYMBOL(sock_recv_errqueue);
3667 
3668 /*
3669  *	Get a socket option on an socket.
3670  *
3671  *	FIX: POSIX 1003.1g is very ambiguous here. It states that
3672  *	asynchronous errors should be reported by getsockopt. We assume
3673  *	this means if you specify SO_ERROR (otherwise whats the point of it).
3674  */
3675 int sock_common_getsockopt(struct socket *sock, int level, int optname,
3676 			   char __user *optval, int __user *optlen)
3677 {
3678 	struct sock *sk = sock->sk;
3679 
3680 	/* IPV6_ADDRFORM can change sk->sk_prot under us. */
3681 	return READ_ONCE(sk->sk_prot)->getsockopt(sk, level, optname, optval, optlen);
3682 }
3683 EXPORT_SYMBOL(sock_common_getsockopt);
3684 
3685 int sock_common_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
3686 			int flags)
3687 {
3688 	struct sock *sk = sock->sk;
3689 	int addr_len = 0;
3690 	int err;
3691 
3692 	err = sk->sk_prot->recvmsg(sk, msg, size, flags, &addr_len);
3693 	if (err >= 0)
3694 		msg->msg_namelen = addr_len;
3695 	return err;
3696 }
3697 EXPORT_SYMBOL(sock_common_recvmsg);
3698 
3699 /*
3700  *	Set socket options on an inet socket.
3701  */
3702 int sock_common_setsockopt(struct socket *sock, int level, int optname,
3703 			   sockptr_t optval, unsigned int optlen)
3704 {
3705 	struct sock *sk = sock->sk;
3706 
3707 	/* IPV6_ADDRFORM can change sk->sk_prot under us. */
3708 	return READ_ONCE(sk->sk_prot)->setsockopt(sk, level, optname, optval, optlen);
3709 }
3710 EXPORT_SYMBOL(sock_common_setsockopt);
3711 
3712 void sk_common_release(struct sock *sk)
3713 {
3714 	if (sk->sk_prot->destroy)
3715 		sk->sk_prot->destroy(sk);
3716 
3717 	/*
3718 	 * Observation: when sk_common_release is called, processes have
3719 	 * no access to socket. But net still has.
3720 	 * Step one, detach it from networking:
3721 	 *
3722 	 * A. Remove from hash tables.
3723 	 */
3724 
3725 	sk->sk_prot->unhash(sk);
3726 
3727 	/*
3728 	 * In this point socket cannot receive new packets, but it is possible
3729 	 * that some packets are in flight because some CPU runs receiver and
3730 	 * did hash table lookup before we unhashed socket. They will achieve
3731 	 * receive queue and will be purged by socket destructor.
3732 	 *
3733 	 * Also we still have packets pending on receive queue and probably,
3734 	 * our own packets waiting in device queues. sock_destroy will drain
3735 	 * receive queue, but transmitted packets will delay socket destruction
3736 	 * until the last reference will be released.
3737 	 */
3738 
3739 	sock_orphan(sk);
3740 
3741 	xfrm_sk_free_policy(sk);
3742 
3743 	sock_put(sk);
3744 }
3745 EXPORT_SYMBOL(sk_common_release);
3746 
3747 void sk_get_meminfo(const struct sock *sk, u32 *mem)
3748 {
3749 	memset(mem, 0, sizeof(*mem) * SK_MEMINFO_VARS);
3750 
3751 	mem[SK_MEMINFO_RMEM_ALLOC] = sk_rmem_alloc_get(sk);
3752 	mem[SK_MEMINFO_RCVBUF] = READ_ONCE(sk->sk_rcvbuf);
3753 	mem[SK_MEMINFO_WMEM_ALLOC] = sk_wmem_alloc_get(sk);
3754 	mem[SK_MEMINFO_SNDBUF] = READ_ONCE(sk->sk_sndbuf);
3755 	mem[SK_MEMINFO_FWD_ALLOC] = sk_forward_alloc_get(sk);
3756 	mem[SK_MEMINFO_WMEM_QUEUED] = READ_ONCE(sk->sk_wmem_queued);
3757 	mem[SK_MEMINFO_OPTMEM] = atomic_read(&sk->sk_omem_alloc);
3758 	mem[SK_MEMINFO_BACKLOG] = READ_ONCE(sk->sk_backlog.len);
3759 	mem[SK_MEMINFO_DROPS] = atomic_read(&sk->sk_drops);
3760 }
3761 
3762 #ifdef CONFIG_PROC_FS
3763 static DECLARE_BITMAP(proto_inuse_idx, PROTO_INUSE_NR);
3764 
3765 int sock_prot_inuse_get(struct net *net, struct proto *prot)
3766 {
3767 	int cpu, idx = prot->inuse_idx;
3768 	int res = 0;
3769 
3770 	for_each_possible_cpu(cpu)
3771 		res += per_cpu_ptr(net->core.prot_inuse, cpu)->val[idx];
3772 
3773 	return res >= 0 ? res : 0;
3774 }
3775 EXPORT_SYMBOL_GPL(sock_prot_inuse_get);
3776 
3777 int sock_inuse_get(struct net *net)
3778 {
3779 	int cpu, res = 0;
3780 
3781 	for_each_possible_cpu(cpu)
3782 		res += per_cpu_ptr(net->core.prot_inuse, cpu)->all;
3783 
3784 	return res;
3785 }
3786 
3787 EXPORT_SYMBOL_GPL(sock_inuse_get);
3788 
3789 static int __net_init sock_inuse_init_net(struct net *net)
3790 {
3791 	net->core.prot_inuse = alloc_percpu(struct prot_inuse);
3792 	if (net->core.prot_inuse == NULL)
3793 		return -ENOMEM;
3794 	return 0;
3795 }
3796 
3797 static void __net_exit sock_inuse_exit_net(struct net *net)
3798 {
3799 	free_percpu(net->core.prot_inuse);
3800 }
3801 
3802 static struct pernet_operations net_inuse_ops = {
3803 	.init = sock_inuse_init_net,
3804 	.exit = sock_inuse_exit_net,
3805 };
3806 
3807 static __init int net_inuse_init(void)
3808 {
3809 	if (register_pernet_subsys(&net_inuse_ops))
3810 		panic("Cannot initialize net inuse counters");
3811 
3812 	return 0;
3813 }
3814 
3815 core_initcall(net_inuse_init);
3816 
3817 static int assign_proto_idx(struct proto *prot)
3818 {
3819 	prot->inuse_idx = find_first_zero_bit(proto_inuse_idx, PROTO_INUSE_NR);
3820 
3821 	if (unlikely(prot->inuse_idx == PROTO_INUSE_NR - 1)) {
3822 		pr_err("PROTO_INUSE_NR exhausted\n");
3823 		return -ENOSPC;
3824 	}
3825 
3826 	set_bit(prot->inuse_idx, proto_inuse_idx);
3827 	return 0;
3828 }
3829 
3830 static void release_proto_idx(struct proto *prot)
3831 {
3832 	if (prot->inuse_idx != PROTO_INUSE_NR - 1)
3833 		clear_bit(prot->inuse_idx, proto_inuse_idx);
3834 }
3835 #else
3836 static inline int assign_proto_idx(struct proto *prot)
3837 {
3838 	return 0;
3839 }
3840 
3841 static inline void release_proto_idx(struct proto *prot)
3842 {
3843 }
3844 
3845 #endif
3846 
3847 static void tw_prot_cleanup(struct timewait_sock_ops *twsk_prot)
3848 {
3849 	if (!twsk_prot)
3850 		return;
3851 	kfree(twsk_prot->twsk_slab_name);
3852 	twsk_prot->twsk_slab_name = NULL;
3853 	kmem_cache_destroy(twsk_prot->twsk_slab);
3854 	twsk_prot->twsk_slab = NULL;
3855 }
3856 
3857 static int tw_prot_init(const struct proto *prot)
3858 {
3859 	struct timewait_sock_ops *twsk_prot = prot->twsk_prot;
3860 
3861 	if (!twsk_prot)
3862 		return 0;
3863 
3864 	twsk_prot->twsk_slab_name = kasprintf(GFP_KERNEL, "tw_sock_%s",
3865 					      prot->name);
3866 	if (!twsk_prot->twsk_slab_name)
3867 		return -ENOMEM;
3868 
3869 	twsk_prot->twsk_slab =
3870 		kmem_cache_create(twsk_prot->twsk_slab_name,
3871 				  twsk_prot->twsk_obj_size, 0,
3872 				  SLAB_ACCOUNT | prot->slab_flags,
3873 				  NULL);
3874 	if (!twsk_prot->twsk_slab) {
3875 		pr_crit("%s: Can't create timewait sock SLAB cache!\n",
3876 			prot->name);
3877 		return -ENOMEM;
3878 	}
3879 
3880 	return 0;
3881 }
3882 
3883 static void req_prot_cleanup(struct request_sock_ops *rsk_prot)
3884 {
3885 	if (!rsk_prot)
3886 		return;
3887 	kfree(rsk_prot->slab_name);
3888 	rsk_prot->slab_name = NULL;
3889 	kmem_cache_destroy(rsk_prot->slab);
3890 	rsk_prot->slab = NULL;
3891 }
3892 
3893 static int req_prot_init(const struct proto *prot)
3894 {
3895 	struct request_sock_ops *rsk_prot = prot->rsk_prot;
3896 
3897 	if (!rsk_prot)
3898 		return 0;
3899 
3900 	rsk_prot->slab_name = kasprintf(GFP_KERNEL, "request_sock_%s",
3901 					prot->name);
3902 	if (!rsk_prot->slab_name)
3903 		return -ENOMEM;
3904 
3905 	rsk_prot->slab = kmem_cache_create(rsk_prot->slab_name,
3906 					   rsk_prot->obj_size, 0,
3907 					   SLAB_ACCOUNT | prot->slab_flags,
3908 					   NULL);
3909 
3910 	if (!rsk_prot->slab) {
3911 		pr_crit("%s: Can't create request sock SLAB cache!\n",
3912 			prot->name);
3913 		return -ENOMEM;
3914 	}
3915 	return 0;
3916 }
3917 
3918 int proto_register(struct proto *prot, int alloc_slab)
3919 {
3920 	int ret = -ENOBUFS;
3921 
3922 	if (prot->memory_allocated && !prot->sysctl_mem) {
3923 		pr_err("%s: missing sysctl_mem\n", prot->name);
3924 		return -EINVAL;
3925 	}
3926 	if (prot->memory_allocated && !prot->per_cpu_fw_alloc) {
3927 		pr_err("%s: missing per_cpu_fw_alloc\n", prot->name);
3928 		return -EINVAL;
3929 	}
3930 	if (alloc_slab) {
3931 		prot->slab = kmem_cache_create_usercopy(prot->name,
3932 					prot->obj_size, 0,
3933 					SLAB_HWCACHE_ALIGN | SLAB_ACCOUNT |
3934 					prot->slab_flags,
3935 					prot->useroffset, prot->usersize,
3936 					NULL);
3937 
3938 		if (prot->slab == NULL) {
3939 			pr_crit("%s: Can't create sock SLAB cache!\n",
3940 				prot->name);
3941 			goto out;
3942 		}
3943 
3944 		if (req_prot_init(prot))
3945 			goto out_free_request_sock_slab;
3946 
3947 		if (tw_prot_init(prot))
3948 			goto out_free_timewait_sock_slab;
3949 	}
3950 
3951 	mutex_lock(&proto_list_mutex);
3952 	ret = assign_proto_idx(prot);
3953 	if (ret) {
3954 		mutex_unlock(&proto_list_mutex);
3955 		goto out_free_timewait_sock_slab;
3956 	}
3957 	list_add(&prot->node, &proto_list);
3958 	mutex_unlock(&proto_list_mutex);
3959 	return ret;
3960 
3961 out_free_timewait_sock_slab:
3962 	if (alloc_slab)
3963 		tw_prot_cleanup(prot->twsk_prot);
3964 out_free_request_sock_slab:
3965 	if (alloc_slab) {
3966 		req_prot_cleanup(prot->rsk_prot);
3967 
3968 		kmem_cache_destroy(prot->slab);
3969 		prot->slab = NULL;
3970 	}
3971 out:
3972 	return ret;
3973 }
3974 EXPORT_SYMBOL(proto_register);
3975 
3976 void proto_unregister(struct proto *prot)
3977 {
3978 	mutex_lock(&proto_list_mutex);
3979 	release_proto_idx(prot);
3980 	list_del(&prot->node);
3981 	mutex_unlock(&proto_list_mutex);
3982 
3983 	kmem_cache_destroy(prot->slab);
3984 	prot->slab = NULL;
3985 
3986 	req_prot_cleanup(prot->rsk_prot);
3987 	tw_prot_cleanup(prot->twsk_prot);
3988 }
3989 EXPORT_SYMBOL(proto_unregister);
3990 
3991 int sock_load_diag_module(int family, int protocol)
3992 {
3993 	if (!protocol) {
3994 		if (!sock_is_registered(family))
3995 			return -ENOENT;
3996 
3997 		return request_module("net-pf-%d-proto-%d-type-%d", PF_NETLINK,
3998 				      NETLINK_SOCK_DIAG, family);
3999 	}
4000 
4001 #ifdef CONFIG_INET
4002 	if (family == AF_INET &&
4003 	    protocol != IPPROTO_RAW &&
4004 	    protocol < MAX_INET_PROTOS &&
4005 	    !rcu_access_pointer(inet_protos[protocol]))
4006 		return -ENOENT;
4007 #endif
4008 
4009 	return request_module("net-pf-%d-proto-%d-type-%d-%d", PF_NETLINK,
4010 			      NETLINK_SOCK_DIAG, family, protocol);
4011 }
4012 EXPORT_SYMBOL(sock_load_diag_module);
4013 
4014 #ifdef CONFIG_PROC_FS
4015 static void *proto_seq_start(struct seq_file *seq, loff_t *pos)
4016 	__acquires(proto_list_mutex)
4017 {
4018 	mutex_lock(&proto_list_mutex);
4019 	return seq_list_start_head(&proto_list, *pos);
4020 }
4021 
4022 static void *proto_seq_next(struct seq_file *seq, void *v, loff_t *pos)
4023 {
4024 	return seq_list_next(v, &proto_list, pos);
4025 }
4026 
4027 static void proto_seq_stop(struct seq_file *seq, void *v)
4028 	__releases(proto_list_mutex)
4029 {
4030 	mutex_unlock(&proto_list_mutex);
4031 }
4032 
4033 static char proto_method_implemented(const void *method)
4034 {
4035 	return method == NULL ? 'n' : 'y';
4036 }
4037 static long sock_prot_memory_allocated(struct proto *proto)
4038 {
4039 	return proto->memory_allocated != NULL ? proto_memory_allocated(proto) : -1L;
4040 }
4041 
4042 static const char *sock_prot_memory_pressure(struct proto *proto)
4043 {
4044 	return proto->memory_pressure != NULL ?
4045 	proto_memory_pressure(proto) ? "yes" : "no" : "NI";
4046 }
4047 
4048 static void proto_seq_printf(struct seq_file *seq, struct proto *proto)
4049 {
4050 
4051 	seq_printf(seq, "%-9s %4u %6d  %6ld   %-3s %6u   %-3s  %-10s "
4052 			"%2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c\n",
4053 		   proto->name,
4054 		   proto->obj_size,
4055 		   sock_prot_inuse_get(seq_file_net(seq), proto),
4056 		   sock_prot_memory_allocated(proto),
4057 		   sock_prot_memory_pressure(proto),
4058 		   proto->max_header,
4059 		   proto->slab == NULL ? "no" : "yes",
4060 		   module_name(proto->owner),
4061 		   proto_method_implemented(proto->close),
4062 		   proto_method_implemented(proto->connect),
4063 		   proto_method_implemented(proto->disconnect),
4064 		   proto_method_implemented(proto->accept),
4065 		   proto_method_implemented(proto->ioctl),
4066 		   proto_method_implemented(proto->init),
4067 		   proto_method_implemented(proto->destroy),
4068 		   proto_method_implemented(proto->shutdown),
4069 		   proto_method_implemented(proto->setsockopt),
4070 		   proto_method_implemented(proto->getsockopt),
4071 		   proto_method_implemented(proto->sendmsg),
4072 		   proto_method_implemented(proto->recvmsg),
4073 		   proto_method_implemented(proto->bind),
4074 		   proto_method_implemented(proto->backlog_rcv),
4075 		   proto_method_implemented(proto->hash),
4076 		   proto_method_implemented(proto->unhash),
4077 		   proto_method_implemented(proto->get_port),
4078 		   proto_method_implemented(proto->enter_memory_pressure));
4079 }
4080 
4081 static int proto_seq_show(struct seq_file *seq, void *v)
4082 {
4083 	if (v == &proto_list)
4084 		seq_printf(seq, "%-9s %-4s %-8s %-6s %-5s %-7s %-4s %-10s %s",
4085 			   "protocol",
4086 			   "size",
4087 			   "sockets",
4088 			   "memory",
4089 			   "press",
4090 			   "maxhdr",
4091 			   "slab",
4092 			   "module",
4093 			   "cl co di ac io in de sh ss gs se re bi br ha uh gp em\n");
4094 	else
4095 		proto_seq_printf(seq, list_entry(v, struct proto, node));
4096 	return 0;
4097 }
4098 
4099 static const struct seq_operations proto_seq_ops = {
4100 	.start  = proto_seq_start,
4101 	.next   = proto_seq_next,
4102 	.stop   = proto_seq_stop,
4103 	.show   = proto_seq_show,
4104 };
4105 
4106 static __net_init int proto_init_net(struct net *net)
4107 {
4108 	if (!proc_create_net("protocols", 0444, net->proc_net, &proto_seq_ops,
4109 			sizeof(struct seq_net_private)))
4110 		return -ENOMEM;
4111 
4112 	return 0;
4113 }
4114 
4115 static __net_exit void proto_exit_net(struct net *net)
4116 {
4117 	remove_proc_entry("protocols", net->proc_net);
4118 }
4119 
4120 
4121 static __net_initdata struct pernet_operations proto_net_ops = {
4122 	.init = proto_init_net,
4123 	.exit = proto_exit_net,
4124 };
4125 
4126 static int __init proto_init(void)
4127 {
4128 	return register_pernet_subsys(&proto_net_ops);
4129 }
4130 
4131 subsys_initcall(proto_init);
4132 
4133 #endif /* PROC_FS */
4134 
4135 #ifdef CONFIG_NET_RX_BUSY_POLL
4136 bool sk_busy_loop_end(void *p, unsigned long start_time)
4137 {
4138 	struct sock *sk = p;
4139 
4140 	if (!skb_queue_empty_lockless(&sk->sk_receive_queue))
4141 		return true;
4142 
4143 	if (sk_is_udp(sk) &&
4144 	    !skb_queue_empty_lockless(&udp_sk(sk)->reader_queue))
4145 		return true;
4146 
4147 	return sk_busy_loop_timeout(sk, start_time);
4148 }
4149 EXPORT_SYMBOL(sk_busy_loop_end);
4150 #endif /* CONFIG_NET_RX_BUSY_POLL */
4151 
4152 int sock_bind_add(struct sock *sk, struct sockaddr *addr, int addr_len)
4153 {
4154 	if (!sk->sk_prot->bind_add)
4155 		return -EOPNOTSUPP;
4156 	return sk->sk_prot->bind_add(sk, addr, addr_len);
4157 }
4158 EXPORT_SYMBOL(sock_bind_add);
4159 
4160 /* Copy 'size' bytes from userspace and return `size` back to userspace */
4161 int sock_ioctl_inout(struct sock *sk, unsigned int cmd,
4162 		     void __user *arg, void *karg, size_t size)
4163 {
4164 	int ret;
4165 
4166 	if (copy_from_user(karg, arg, size))
4167 		return -EFAULT;
4168 
4169 	ret = READ_ONCE(sk->sk_prot)->ioctl(sk, cmd, karg);
4170 	if (ret)
4171 		return ret;
4172 
4173 	if (copy_to_user(arg, karg, size))
4174 		return -EFAULT;
4175 
4176 	return 0;
4177 }
4178 EXPORT_SYMBOL(sock_ioctl_inout);
4179 
4180 /* This is the most common ioctl prep function, where the result (4 bytes) is
4181  * copied back to userspace if the ioctl() returns successfully. No input is
4182  * copied from userspace as input argument.
4183  */
4184 static int sock_ioctl_out(struct sock *sk, unsigned int cmd, void __user *arg)
4185 {
4186 	int ret, karg = 0;
4187 
4188 	ret = READ_ONCE(sk->sk_prot)->ioctl(sk, cmd, &karg);
4189 	if (ret)
4190 		return ret;
4191 
4192 	return put_user(karg, (int __user *)arg);
4193 }
4194 
4195 /* A wrapper around sock ioctls, which copies the data from userspace
4196  * (depending on the protocol/ioctl), and copies back the result to userspace.
4197  * The main motivation for this function is to pass kernel memory to the
4198  * protocol ioctl callbacks, instead of userspace memory.
4199  */
4200 int sk_ioctl(struct sock *sk, unsigned int cmd, void __user *arg)
4201 {
4202 	int rc = 1;
4203 
4204 	if (sk->sk_type == SOCK_RAW && sk->sk_family == AF_INET)
4205 		rc = ipmr_sk_ioctl(sk, cmd, arg);
4206 	else if (sk->sk_type == SOCK_RAW && sk->sk_family == AF_INET6)
4207 		rc = ip6mr_sk_ioctl(sk, cmd, arg);
4208 	else if (sk_is_phonet(sk))
4209 		rc = phonet_sk_ioctl(sk, cmd, arg);
4210 
4211 	/* If ioctl was processed, returns its value */
4212 	if (rc <= 0)
4213 		return rc;
4214 
4215 	/* Otherwise call the default handler */
4216 	return sock_ioctl_out(sk, cmd, arg);
4217 }
4218 EXPORT_SYMBOL(sk_ioctl);
4219