xref: /openbmc/linux/net/core/sock.c (revision 586b4106)
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 int sysctl_mem_pcpu_rsv __read_mostly = SK_MEMORY_PCPU_RESERVE;
287 
288 /* Maximal space eaten by iovec or ancillary data plus some space */
289 int sysctl_optmem_max __read_mostly = sizeof(unsigned long)*(2*UIO_MAXIOV+512);
290 EXPORT_SYMBOL(sysctl_optmem_max);
291 
292 int sysctl_tstamp_allow_data __read_mostly = 1;
293 
294 DEFINE_STATIC_KEY_FALSE(memalloc_socks_key);
295 EXPORT_SYMBOL_GPL(memalloc_socks_key);
296 
297 /**
298  * sk_set_memalloc - sets %SOCK_MEMALLOC
299  * @sk: socket to set it on
300  *
301  * Set %SOCK_MEMALLOC on a socket for access to emergency reserves.
302  * It's the responsibility of the admin to adjust min_free_kbytes
303  * to meet the requirements
304  */
305 void sk_set_memalloc(struct sock *sk)
306 {
307 	sock_set_flag(sk, SOCK_MEMALLOC);
308 	sk->sk_allocation |= __GFP_MEMALLOC;
309 	static_branch_inc(&memalloc_socks_key);
310 }
311 EXPORT_SYMBOL_GPL(sk_set_memalloc);
312 
313 void sk_clear_memalloc(struct sock *sk)
314 {
315 	sock_reset_flag(sk, SOCK_MEMALLOC);
316 	sk->sk_allocation &= ~__GFP_MEMALLOC;
317 	static_branch_dec(&memalloc_socks_key);
318 
319 	/*
320 	 * SOCK_MEMALLOC is allowed to ignore rmem limits to ensure forward
321 	 * progress of swapping. SOCK_MEMALLOC may be cleared while
322 	 * it has rmem allocations due to the last swapfile being deactivated
323 	 * but there is a risk that the socket is unusable due to exceeding
324 	 * the rmem limits. Reclaim the reserves and obey rmem limits again.
325 	 */
326 	sk_mem_reclaim(sk);
327 }
328 EXPORT_SYMBOL_GPL(sk_clear_memalloc);
329 
330 int __sk_backlog_rcv(struct sock *sk, struct sk_buff *skb)
331 {
332 	int ret;
333 	unsigned int noreclaim_flag;
334 
335 	/* these should have been dropped before queueing */
336 	BUG_ON(!sock_flag(sk, SOCK_MEMALLOC));
337 
338 	noreclaim_flag = memalloc_noreclaim_save();
339 	ret = INDIRECT_CALL_INET(sk->sk_backlog_rcv,
340 				 tcp_v6_do_rcv,
341 				 tcp_v4_do_rcv,
342 				 sk, skb);
343 	memalloc_noreclaim_restore(noreclaim_flag);
344 
345 	return ret;
346 }
347 EXPORT_SYMBOL(__sk_backlog_rcv);
348 
349 void sk_error_report(struct sock *sk)
350 {
351 	sk->sk_error_report(sk);
352 
353 	switch (sk->sk_family) {
354 	case AF_INET:
355 		fallthrough;
356 	case AF_INET6:
357 		trace_inet_sk_error_report(sk);
358 		break;
359 	default:
360 		break;
361 	}
362 }
363 EXPORT_SYMBOL(sk_error_report);
364 
365 int sock_get_timeout(long timeo, void *optval, bool old_timeval)
366 {
367 	struct __kernel_sock_timeval tv;
368 
369 	if (timeo == MAX_SCHEDULE_TIMEOUT) {
370 		tv.tv_sec = 0;
371 		tv.tv_usec = 0;
372 	} else {
373 		tv.tv_sec = timeo / HZ;
374 		tv.tv_usec = ((timeo % HZ) * USEC_PER_SEC) / HZ;
375 	}
376 
377 	if (old_timeval && in_compat_syscall() && !COMPAT_USE_64BIT_TIME) {
378 		struct old_timeval32 tv32 = { tv.tv_sec, tv.tv_usec };
379 		*(struct old_timeval32 *)optval = tv32;
380 		return sizeof(tv32);
381 	}
382 
383 	if (old_timeval) {
384 		struct __kernel_old_timeval old_tv;
385 		old_tv.tv_sec = tv.tv_sec;
386 		old_tv.tv_usec = tv.tv_usec;
387 		*(struct __kernel_old_timeval *)optval = old_tv;
388 		return sizeof(old_tv);
389 	}
390 
391 	*(struct __kernel_sock_timeval *)optval = tv;
392 	return sizeof(tv);
393 }
394 EXPORT_SYMBOL(sock_get_timeout);
395 
396 int sock_copy_user_timeval(struct __kernel_sock_timeval *tv,
397 			   sockptr_t optval, int optlen, bool old_timeval)
398 {
399 	if (old_timeval && in_compat_syscall() && !COMPAT_USE_64BIT_TIME) {
400 		struct old_timeval32 tv32;
401 
402 		if (optlen < sizeof(tv32))
403 			return -EINVAL;
404 
405 		if (copy_from_sockptr(&tv32, optval, sizeof(tv32)))
406 			return -EFAULT;
407 		tv->tv_sec = tv32.tv_sec;
408 		tv->tv_usec = tv32.tv_usec;
409 	} else if (old_timeval) {
410 		struct __kernel_old_timeval old_tv;
411 
412 		if (optlen < sizeof(old_tv))
413 			return -EINVAL;
414 		if (copy_from_sockptr(&old_tv, optval, sizeof(old_tv)))
415 			return -EFAULT;
416 		tv->tv_sec = old_tv.tv_sec;
417 		tv->tv_usec = old_tv.tv_usec;
418 	} else {
419 		if (optlen < sizeof(*tv))
420 			return -EINVAL;
421 		if (copy_from_sockptr(tv, optval, sizeof(*tv)))
422 			return -EFAULT;
423 	}
424 
425 	return 0;
426 }
427 EXPORT_SYMBOL(sock_copy_user_timeval);
428 
429 static int sock_set_timeout(long *timeo_p, sockptr_t optval, int optlen,
430 			    bool old_timeval)
431 {
432 	struct __kernel_sock_timeval tv;
433 	int err = sock_copy_user_timeval(&tv, optval, optlen, old_timeval);
434 	long val;
435 
436 	if (err)
437 		return err;
438 
439 	if (tv.tv_usec < 0 || tv.tv_usec >= USEC_PER_SEC)
440 		return -EDOM;
441 
442 	if (tv.tv_sec < 0) {
443 		static int warned __read_mostly;
444 
445 		WRITE_ONCE(*timeo_p, 0);
446 		if (warned < 10 && net_ratelimit()) {
447 			warned++;
448 			pr_info("%s: `%s' (pid %d) tries to set negative timeout\n",
449 				__func__, current->comm, task_pid_nr(current));
450 		}
451 		return 0;
452 	}
453 	val = MAX_SCHEDULE_TIMEOUT;
454 	if ((tv.tv_sec || tv.tv_usec) &&
455 	    (tv.tv_sec < (MAX_SCHEDULE_TIMEOUT / HZ - 1)))
456 		val = tv.tv_sec * HZ + DIV_ROUND_UP((unsigned long)tv.tv_usec,
457 						    USEC_PER_SEC / HZ);
458 	WRITE_ONCE(*timeo_p, val);
459 	return 0;
460 }
461 
462 static bool sock_needs_netstamp(const struct sock *sk)
463 {
464 	switch (sk->sk_family) {
465 	case AF_UNSPEC:
466 	case AF_UNIX:
467 		return false;
468 	default:
469 		return true;
470 	}
471 }
472 
473 static void sock_disable_timestamp(struct sock *sk, unsigned long flags)
474 {
475 	if (sk->sk_flags & flags) {
476 		sk->sk_flags &= ~flags;
477 		if (sock_needs_netstamp(sk) &&
478 		    !(sk->sk_flags & SK_FLAGS_TIMESTAMP))
479 			net_disable_timestamp();
480 	}
481 }
482 
483 
484 int __sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
485 {
486 	unsigned long flags;
487 	struct sk_buff_head *list = &sk->sk_receive_queue;
488 
489 	if (atomic_read(&sk->sk_rmem_alloc) >= READ_ONCE(sk->sk_rcvbuf)) {
490 		atomic_inc(&sk->sk_drops);
491 		trace_sock_rcvqueue_full(sk, skb);
492 		return -ENOMEM;
493 	}
494 
495 	if (!sk_rmem_schedule(sk, skb, skb->truesize)) {
496 		atomic_inc(&sk->sk_drops);
497 		return -ENOBUFS;
498 	}
499 
500 	skb->dev = NULL;
501 	skb_set_owner_r(skb, sk);
502 
503 	/* we escape from rcu protected region, make sure we dont leak
504 	 * a norefcounted dst
505 	 */
506 	skb_dst_force(skb);
507 
508 	spin_lock_irqsave(&list->lock, flags);
509 	sock_skb_set_dropcount(sk, skb);
510 	__skb_queue_tail(list, skb);
511 	spin_unlock_irqrestore(&list->lock, flags);
512 
513 	if (!sock_flag(sk, SOCK_DEAD))
514 		sk->sk_data_ready(sk);
515 	return 0;
516 }
517 EXPORT_SYMBOL(__sock_queue_rcv_skb);
518 
519 int sock_queue_rcv_skb_reason(struct sock *sk, struct sk_buff *skb,
520 			      enum skb_drop_reason *reason)
521 {
522 	enum skb_drop_reason drop_reason;
523 	int err;
524 
525 	err = sk_filter(sk, skb);
526 	if (err) {
527 		drop_reason = SKB_DROP_REASON_SOCKET_FILTER;
528 		goto out;
529 	}
530 	err = __sock_queue_rcv_skb(sk, skb);
531 	switch (err) {
532 	case -ENOMEM:
533 		drop_reason = SKB_DROP_REASON_SOCKET_RCVBUFF;
534 		break;
535 	case -ENOBUFS:
536 		drop_reason = SKB_DROP_REASON_PROTO_MEM;
537 		break;
538 	default:
539 		drop_reason = SKB_NOT_DROPPED_YET;
540 		break;
541 	}
542 out:
543 	if (reason)
544 		*reason = drop_reason;
545 	return err;
546 }
547 EXPORT_SYMBOL(sock_queue_rcv_skb_reason);
548 
549 int __sk_receive_skb(struct sock *sk, struct sk_buff *skb,
550 		     const int nested, unsigned int trim_cap, bool refcounted)
551 {
552 	int rc = NET_RX_SUCCESS;
553 
554 	if (sk_filter_trim_cap(sk, skb, trim_cap))
555 		goto discard_and_relse;
556 
557 	skb->dev = NULL;
558 
559 	if (sk_rcvqueues_full(sk, READ_ONCE(sk->sk_rcvbuf))) {
560 		atomic_inc(&sk->sk_drops);
561 		goto discard_and_relse;
562 	}
563 	if (nested)
564 		bh_lock_sock_nested(sk);
565 	else
566 		bh_lock_sock(sk);
567 	if (!sock_owned_by_user(sk)) {
568 		/*
569 		 * trylock + unlock semantics:
570 		 */
571 		mutex_acquire(&sk->sk_lock.dep_map, 0, 1, _RET_IP_);
572 
573 		rc = sk_backlog_rcv(sk, skb);
574 
575 		mutex_release(&sk->sk_lock.dep_map, _RET_IP_);
576 	} else if (sk_add_backlog(sk, skb, READ_ONCE(sk->sk_rcvbuf))) {
577 		bh_unlock_sock(sk);
578 		atomic_inc(&sk->sk_drops);
579 		goto discard_and_relse;
580 	}
581 
582 	bh_unlock_sock(sk);
583 out:
584 	if (refcounted)
585 		sock_put(sk);
586 	return rc;
587 discard_and_relse:
588 	kfree_skb(skb);
589 	goto out;
590 }
591 EXPORT_SYMBOL(__sk_receive_skb);
592 
593 INDIRECT_CALLABLE_DECLARE(struct dst_entry *ip6_dst_check(struct dst_entry *,
594 							  u32));
595 INDIRECT_CALLABLE_DECLARE(struct dst_entry *ipv4_dst_check(struct dst_entry *,
596 							   u32));
597 struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie)
598 {
599 	struct dst_entry *dst = __sk_dst_get(sk);
600 
601 	if (dst && dst->obsolete &&
602 	    INDIRECT_CALL_INET(dst->ops->check, ip6_dst_check, ipv4_dst_check,
603 			       dst, cookie) == NULL) {
604 		sk_tx_queue_clear(sk);
605 		WRITE_ONCE(sk->sk_dst_pending_confirm, 0);
606 		RCU_INIT_POINTER(sk->sk_dst_cache, NULL);
607 		dst_release(dst);
608 		return NULL;
609 	}
610 
611 	return dst;
612 }
613 EXPORT_SYMBOL(__sk_dst_check);
614 
615 struct dst_entry *sk_dst_check(struct sock *sk, u32 cookie)
616 {
617 	struct dst_entry *dst = sk_dst_get(sk);
618 
619 	if (dst && dst->obsolete &&
620 	    INDIRECT_CALL_INET(dst->ops->check, ip6_dst_check, ipv4_dst_check,
621 			       dst, cookie) == NULL) {
622 		sk_dst_reset(sk);
623 		dst_release(dst);
624 		return NULL;
625 	}
626 
627 	return dst;
628 }
629 EXPORT_SYMBOL(sk_dst_check);
630 
631 static int sock_bindtoindex_locked(struct sock *sk, int ifindex)
632 {
633 	int ret = -ENOPROTOOPT;
634 #ifdef CONFIG_NETDEVICES
635 	struct net *net = sock_net(sk);
636 
637 	/* Sorry... */
638 	ret = -EPERM;
639 	if (sk->sk_bound_dev_if && !ns_capable(net->user_ns, CAP_NET_RAW))
640 		goto out;
641 
642 	ret = -EINVAL;
643 	if (ifindex < 0)
644 		goto out;
645 
646 	/* Paired with all READ_ONCE() done locklessly. */
647 	WRITE_ONCE(sk->sk_bound_dev_if, ifindex);
648 
649 	if (sk->sk_prot->rehash)
650 		sk->sk_prot->rehash(sk);
651 	sk_dst_reset(sk);
652 
653 	ret = 0;
654 
655 out:
656 #endif
657 
658 	return ret;
659 }
660 
661 int sock_bindtoindex(struct sock *sk, int ifindex, bool lock_sk)
662 {
663 	int ret;
664 
665 	if (lock_sk)
666 		lock_sock(sk);
667 	ret = sock_bindtoindex_locked(sk, ifindex);
668 	if (lock_sk)
669 		release_sock(sk);
670 
671 	return ret;
672 }
673 EXPORT_SYMBOL(sock_bindtoindex);
674 
675 static int sock_setbindtodevice(struct sock *sk, sockptr_t optval, int optlen)
676 {
677 	int ret = -ENOPROTOOPT;
678 #ifdef CONFIG_NETDEVICES
679 	struct net *net = sock_net(sk);
680 	char devname[IFNAMSIZ];
681 	int index;
682 
683 	ret = -EINVAL;
684 	if (optlen < 0)
685 		goto out;
686 
687 	/* Bind this socket to a particular device like "eth0",
688 	 * as specified in the passed interface name. If the
689 	 * name is "" or the option length is zero the socket
690 	 * is not bound.
691 	 */
692 	if (optlen > IFNAMSIZ - 1)
693 		optlen = IFNAMSIZ - 1;
694 	memset(devname, 0, sizeof(devname));
695 
696 	ret = -EFAULT;
697 	if (copy_from_sockptr(devname, optval, optlen))
698 		goto out;
699 
700 	index = 0;
701 	if (devname[0] != '\0') {
702 		struct net_device *dev;
703 
704 		rcu_read_lock();
705 		dev = dev_get_by_name_rcu(net, devname);
706 		if (dev)
707 			index = dev->ifindex;
708 		rcu_read_unlock();
709 		ret = -ENODEV;
710 		if (!dev)
711 			goto out;
712 	}
713 
714 	sockopt_lock_sock(sk);
715 	ret = sock_bindtoindex_locked(sk, index);
716 	sockopt_release_sock(sk);
717 out:
718 #endif
719 
720 	return ret;
721 }
722 
723 static int sock_getbindtodevice(struct sock *sk, sockptr_t optval,
724 				sockptr_t optlen, int len)
725 {
726 	int ret = -ENOPROTOOPT;
727 #ifdef CONFIG_NETDEVICES
728 	int bound_dev_if = READ_ONCE(sk->sk_bound_dev_if);
729 	struct net *net = sock_net(sk);
730 	char devname[IFNAMSIZ];
731 
732 	if (bound_dev_if == 0) {
733 		len = 0;
734 		goto zero;
735 	}
736 
737 	ret = -EINVAL;
738 	if (len < IFNAMSIZ)
739 		goto out;
740 
741 	ret = netdev_get_name(net, devname, bound_dev_if);
742 	if (ret)
743 		goto out;
744 
745 	len = strlen(devname) + 1;
746 
747 	ret = -EFAULT;
748 	if (copy_to_sockptr(optval, devname, len))
749 		goto out;
750 
751 zero:
752 	ret = -EFAULT;
753 	if (copy_to_sockptr(optlen, &len, sizeof(int)))
754 		goto out;
755 
756 	ret = 0;
757 
758 out:
759 #endif
760 
761 	return ret;
762 }
763 
764 bool sk_mc_loop(struct sock *sk)
765 {
766 	if (dev_recursion_level())
767 		return false;
768 	if (!sk)
769 		return true;
770 	/* IPV6_ADDRFORM can change sk->sk_family under us. */
771 	switch (READ_ONCE(sk->sk_family)) {
772 	case AF_INET:
773 		return inet_test_bit(MC_LOOP, sk);
774 #if IS_ENABLED(CONFIG_IPV6)
775 	case AF_INET6:
776 		return inet6_sk(sk)->mc_loop;
777 #endif
778 	}
779 	WARN_ON_ONCE(1);
780 	return true;
781 }
782 EXPORT_SYMBOL(sk_mc_loop);
783 
784 void sock_set_reuseaddr(struct sock *sk)
785 {
786 	lock_sock(sk);
787 	sk->sk_reuse = SK_CAN_REUSE;
788 	release_sock(sk);
789 }
790 EXPORT_SYMBOL(sock_set_reuseaddr);
791 
792 void sock_set_reuseport(struct sock *sk)
793 {
794 	lock_sock(sk);
795 	sk->sk_reuseport = true;
796 	release_sock(sk);
797 }
798 EXPORT_SYMBOL(sock_set_reuseport);
799 
800 void sock_no_linger(struct sock *sk)
801 {
802 	lock_sock(sk);
803 	WRITE_ONCE(sk->sk_lingertime, 0);
804 	sock_set_flag(sk, SOCK_LINGER);
805 	release_sock(sk);
806 }
807 EXPORT_SYMBOL(sock_no_linger);
808 
809 void sock_set_priority(struct sock *sk, u32 priority)
810 {
811 	lock_sock(sk);
812 	WRITE_ONCE(sk->sk_priority, priority);
813 	release_sock(sk);
814 }
815 EXPORT_SYMBOL(sock_set_priority);
816 
817 void sock_set_sndtimeo(struct sock *sk, s64 secs)
818 {
819 	lock_sock(sk);
820 	if (secs && secs < MAX_SCHEDULE_TIMEOUT / HZ - 1)
821 		WRITE_ONCE(sk->sk_sndtimeo, secs * HZ);
822 	else
823 		WRITE_ONCE(sk->sk_sndtimeo, MAX_SCHEDULE_TIMEOUT);
824 	release_sock(sk);
825 }
826 EXPORT_SYMBOL(sock_set_sndtimeo);
827 
828 static void __sock_set_timestamps(struct sock *sk, bool val, bool new, bool ns)
829 {
830 	if (val)  {
831 		sock_valbool_flag(sk, SOCK_TSTAMP_NEW, new);
832 		sock_valbool_flag(sk, SOCK_RCVTSTAMPNS, ns);
833 		sock_set_flag(sk, SOCK_RCVTSTAMP);
834 		sock_enable_timestamp(sk, SOCK_TIMESTAMP);
835 	} else {
836 		sock_reset_flag(sk, SOCK_RCVTSTAMP);
837 		sock_reset_flag(sk, SOCK_RCVTSTAMPNS);
838 	}
839 }
840 
841 void sock_enable_timestamps(struct sock *sk)
842 {
843 	lock_sock(sk);
844 	__sock_set_timestamps(sk, true, false, true);
845 	release_sock(sk);
846 }
847 EXPORT_SYMBOL(sock_enable_timestamps);
848 
849 void sock_set_timestamp(struct sock *sk, int optname, bool valbool)
850 {
851 	switch (optname) {
852 	case SO_TIMESTAMP_OLD:
853 		__sock_set_timestamps(sk, valbool, false, false);
854 		break;
855 	case SO_TIMESTAMP_NEW:
856 		__sock_set_timestamps(sk, valbool, true, false);
857 		break;
858 	case SO_TIMESTAMPNS_OLD:
859 		__sock_set_timestamps(sk, valbool, false, true);
860 		break;
861 	case SO_TIMESTAMPNS_NEW:
862 		__sock_set_timestamps(sk, valbool, true, true);
863 		break;
864 	}
865 }
866 
867 static int sock_timestamping_bind_phc(struct sock *sk, int phc_index)
868 {
869 	struct net *net = sock_net(sk);
870 	struct net_device *dev = NULL;
871 	bool match = false;
872 	int *vclock_index;
873 	int i, num;
874 
875 	if (sk->sk_bound_dev_if)
876 		dev = dev_get_by_index(net, sk->sk_bound_dev_if);
877 
878 	if (!dev) {
879 		pr_err("%s: sock not bind to device\n", __func__);
880 		return -EOPNOTSUPP;
881 	}
882 
883 	num = ethtool_get_phc_vclocks(dev, &vclock_index);
884 	dev_put(dev);
885 
886 	for (i = 0; i < num; i++) {
887 		if (*(vclock_index + i) == phc_index) {
888 			match = true;
889 			break;
890 		}
891 	}
892 
893 	if (num > 0)
894 		kfree(vclock_index);
895 
896 	if (!match)
897 		return -EINVAL;
898 
899 	WRITE_ONCE(sk->sk_bind_phc, phc_index);
900 
901 	return 0;
902 }
903 
904 int sock_set_timestamping(struct sock *sk, int optname,
905 			  struct so_timestamping timestamping)
906 {
907 	int val = timestamping.flags;
908 	int ret;
909 
910 	if (val & ~SOF_TIMESTAMPING_MASK)
911 		return -EINVAL;
912 
913 	if (val & SOF_TIMESTAMPING_OPT_ID_TCP &&
914 	    !(val & SOF_TIMESTAMPING_OPT_ID))
915 		return -EINVAL;
916 
917 	if (val & SOF_TIMESTAMPING_OPT_ID &&
918 	    !(sk->sk_tsflags & SOF_TIMESTAMPING_OPT_ID)) {
919 		if (sk_is_tcp(sk)) {
920 			if ((1 << sk->sk_state) &
921 			    (TCPF_CLOSE | TCPF_LISTEN))
922 				return -EINVAL;
923 			if (val & SOF_TIMESTAMPING_OPT_ID_TCP)
924 				atomic_set(&sk->sk_tskey, tcp_sk(sk)->write_seq);
925 			else
926 				atomic_set(&sk->sk_tskey, tcp_sk(sk)->snd_una);
927 		} else {
928 			atomic_set(&sk->sk_tskey, 0);
929 		}
930 	}
931 
932 	if (val & SOF_TIMESTAMPING_OPT_STATS &&
933 	    !(val & SOF_TIMESTAMPING_OPT_TSONLY))
934 		return -EINVAL;
935 
936 	if (val & SOF_TIMESTAMPING_BIND_PHC) {
937 		ret = sock_timestamping_bind_phc(sk, timestamping.bind_phc);
938 		if (ret)
939 			return ret;
940 	}
941 
942 	WRITE_ONCE(sk->sk_tsflags, val);
943 	sock_valbool_flag(sk, SOCK_TSTAMP_NEW, optname == SO_TIMESTAMPING_NEW);
944 
945 	if (val & SOF_TIMESTAMPING_RX_SOFTWARE)
946 		sock_enable_timestamp(sk,
947 				      SOCK_TIMESTAMPING_RX_SOFTWARE);
948 	else
949 		sock_disable_timestamp(sk,
950 				       (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE));
951 	return 0;
952 }
953 
954 void sock_set_keepalive(struct sock *sk)
955 {
956 	lock_sock(sk);
957 	if (sk->sk_prot->keepalive)
958 		sk->sk_prot->keepalive(sk, true);
959 	sock_valbool_flag(sk, SOCK_KEEPOPEN, true);
960 	release_sock(sk);
961 }
962 EXPORT_SYMBOL(sock_set_keepalive);
963 
964 static void __sock_set_rcvbuf(struct sock *sk, int val)
965 {
966 	/* Ensure val * 2 fits into an int, to prevent max_t() from treating it
967 	 * as a negative value.
968 	 */
969 	val = min_t(int, val, INT_MAX / 2);
970 	sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
971 
972 	/* We double it on the way in to account for "struct sk_buff" etc.
973 	 * overhead.   Applications assume that the SO_RCVBUF setting they make
974 	 * will allow that much actual data to be received on that socket.
975 	 *
976 	 * Applications are unaware that "struct sk_buff" and other overheads
977 	 * allocate from the receive buffer during socket buffer allocation.
978 	 *
979 	 * And after considering the possible alternatives, returning the value
980 	 * we actually used in getsockopt is the most desirable behavior.
981 	 */
982 	WRITE_ONCE(sk->sk_rcvbuf, max_t(int, val * 2, SOCK_MIN_RCVBUF));
983 }
984 
985 void sock_set_rcvbuf(struct sock *sk, int val)
986 {
987 	lock_sock(sk);
988 	__sock_set_rcvbuf(sk, val);
989 	release_sock(sk);
990 }
991 EXPORT_SYMBOL(sock_set_rcvbuf);
992 
993 static void __sock_set_mark(struct sock *sk, u32 val)
994 {
995 	if (val != sk->sk_mark) {
996 		WRITE_ONCE(sk->sk_mark, val);
997 		sk_dst_reset(sk);
998 	}
999 }
1000 
1001 void sock_set_mark(struct sock *sk, u32 val)
1002 {
1003 	lock_sock(sk);
1004 	__sock_set_mark(sk, val);
1005 	release_sock(sk);
1006 }
1007 EXPORT_SYMBOL(sock_set_mark);
1008 
1009 static void sock_release_reserved_memory(struct sock *sk, int bytes)
1010 {
1011 	/* Round down bytes to multiple of pages */
1012 	bytes = round_down(bytes, PAGE_SIZE);
1013 
1014 	WARN_ON(bytes > sk->sk_reserved_mem);
1015 	WRITE_ONCE(sk->sk_reserved_mem, sk->sk_reserved_mem - bytes);
1016 	sk_mem_reclaim(sk);
1017 }
1018 
1019 static int sock_reserve_memory(struct sock *sk, int bytes)
1020 {
1021 	long allocated;
1022 	bool charged;
1023 	int pages;
1024 
1025 	if (!mem_cgroup_sockets_enabled || !sk->sk_memcg || !sk_has_account(sk))
1026 		return -EOPNOTSUPP;
1027 
1028 	if (!bytes)
1029 		return 0;
1030 
1031 	pages = sk_mem_pages(bytes);
1032 
1033 	/* pre-charge to memcg */
1034 	charged = mem_cgroup_charge_skmem(sk->sk_memcg, pages,
1035 					  GFP_KERNEL | __GFP_RETRY_MAYFAIL);
1036 	if (!charged)
1037 		return -ENOMEM;
1038 
1039 	/* pre-charge to forward_alloc */
1040 	sk_memory_allocated_add(sk, pages);
1041 	allocated = sk_memory_allocated(sk);
1042 	/* If the system goes into memory pressure with this
1043 	 * precharge, give up and return error.
1044 	 */
1045 	if (allocated > sk_prot_mem_limits(sk, 1)) {
1046 		sk_memory_allocated_sub(sk, pages);
1047 		mem_cgroup_uncharge_skmem(sk->sk_memcg, pages);
1048 		return -ENOMEM;
1049 	}
1050 	sk_forward_alloc_add(sk, pages << PAGE_SHIFT);
1051 
1052 	WRITE_ONCE(sk->sk_reserved_mem,
1053 		   sk->sk_reserved_mem + (pages << PAGE_SHIFT));
1054 
1055 	return 0;
1056 }
1057 
1058 void sockopt_lock_sock(struct sock *sk)
1059 {
1060 	/* When current->bpf_ctx is set, the setsockopt is called from
1061 	 * a bpf prog.  bpf has ensured the sk lock has been
1062 	 * acquired before calling setsockopt().
1063 	 */
1064 	if (has_current_bpf_ctx())
1065 		return;
1066 
1067 	lock_sock(sk);
1068 }
1069 EXPORT_SYMBOL(sockopt_lock_sock);
1070 
1071 void sockopt_release_sock(struct sock *sk)
1072 {
1073 	if (has_current_bpf_ctx())
1074 		return;
1075 
1076 	release_sock(sk);
1077 }
1078 EXPORT_SYMBOL(sockopt_release_sock);
1079 
1080 bool sockopt_ns_capable(struct user_namespace *ns, int cap)
1081 {
1082 	return has_current_bpf_ctx() || ns_capable(ns, cap);
1083 }
1084 EXPORT_SYMBOL(sockopt_ns_capable);
1085 
1086 bool sockopt_capable(int cap)
1087 {
1088 	return has_current_bpf_ctx() || capable(cap);
1089 }
1090 EXPORT_SYMBOL(sockopt_capable);
1091 
1092 /*
1093  *	This is meant for all protocols to use and covers goings on
1094  *	at the socket level. Everything here is generic.
1095  */
1096 
1097 int sk_setsockopt(struct sock *sk, int level, int optname,
1098 		  sockptr_t optval, unsigned int optlen)
1099 {
1100 	struct so_timestamping timestamping;
1101 	struct socket *sock = sk->sk_socket;
1102 	struct sock_txtime sk_txtime;
1103 	int val;
1104 	int valbool;
1105 	struct linger ling;
1106 	int ret = 0;
1107 
1108 	/*
1109 	 *	Options without arguments
1110 	 */
1111 
1112 	if (optname == SO_BINDTODEVICE)
1113 		return sock_setbindtodevice(sk, optval, optlen);
1114 
1115 	if (optlen < sizeof(int))
1116 		return -EINVAL;
1117 
1118 	if (copy_from_sockptr(&val, optval, sizeof(val)))
1119 		return -EFAULT;
1120 
1121 	valbool = val ? 1 : 0;
1122 
1123 	sockopt_lock_sock(sk);
1124 
1125 	switch (optname) {
1126 	case SO_DEBUG:
1127 		if (val && !sockopt_capable(CAP_NET_ADMIN))
1128 			ret = -EACCES;
1129 		else
1130 			sock_valbool_flag(sk, SOCK_DBG, valbool);
1131 		break;
1132 	case SO_REUSEADDR:
1133 		sk->sk_reuse = (valbool ? SK_CAN_REUSE : SK_NO_REUSE);
1134 		break;
1135 	case SO_REUSEPORT:
1136 		sk->sk_reuseport = valbool;
1137 		break;
1138 	case SO_TYPE:
1139 	case SO_PROTOCOL:
1140 	case SO_DOMAIN:
1141 	case SO_ERROR:
1142 		ret = -ENOPROTOOPT;
1143 		break;
1144 	case SO_DONTROUTE:
1145 		sock_valbool_flag(sk, SOCK_LOCALROUTE, valbool);
1146 		sk_dst_reset(sk);
1147 		break;
1148 	case SO_BROADCAST:
1149 		sock_valbool_flag(sk, SOCK_BROADCAST, valbool);
1150 		break;
1151 	case SO_SNDBUF:
1152 		/* Don't error on this BSD doesn't and if you think
1153 		 * about it this is right. Otherwise apps have to
1154 		 * play 'guess the biggest size' games. RCVBUF/SNDBUF
1155 		 * are treated in BSD as hints
1156 		 */
1157 		val = min_t(u32, val, READ_ONCE(sysctl_wmem_max));
1158 set_sndbuf:
1159 		/* Ensure val * 2 fits into an int, to prevent max_t()
1160 		 * from treating it as a negative value.
1161 		 */
1162 		val = min_t(int, val, INT_MAX / 2);
1163 		sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
1164 		WRITE_ONCE(sk->sk_sndbuf,
1165 			   max_t(int, val * 2, SOCK_MIN_SNDBUF));
1166 		/* Wake up sending tasks if we upped the value. */
1167 		sk->sk_write_space(sk);
1168 		break;
1169 
1170 	case SO_SNDBUFFORCE:
1171 		if (!sockopt_capable(CAP_NET_ADMIN)) {
1172 			ret = -EPERM;
1173 			break;
1174 		}
1175 
1176 		/* No negative values (to prevent underflow, as val will be
1177 		 * multiplied by 2).
1178 		 */
1179 		if (val < 0)
1180 			val = 0;
1181 		goto set_sndbuf;
1182 
1183 	case SO_RCVBUF:
1184 		/* Don't error on this BSD doesn't and if you think
1185 		 * about it this is right. Otherwise apps have to
1186 		 * play 'guess the biggest size' games. RCVBUF/SNDBUF
1187 		 * are treated in BSD as hints
1188 		 */
1189 		__sock_set_rcvbuf(sk, min_t(u32, val, READ_ONCE(sysctl_rmem_max)));
1190 		break;
1191 
1192 	case SO_RCVBUFFORCE:
1193 		if (!sockopt_capable(CAP_NET_ADMIN)) {
1194 			ret = -EPERM;
1195 			break;
1196 		}
1197 
1198 		/* No negative values (to prevent underflow, as val will be
1199 		 * multiplied by 2).
1200 		 */
1201 		__sock_set_rcvbuf(sk, max(val, 0));
1202 		break;
1203 
1204 	case SO_KEEPALIVE:
1205 		if (sk->sk_prot->keepalive)
1206 			sk->sk_prot->keepalive(sk, valbool);
1207 		sock_valbool_flag(sk, SOCK_KEEPOPEN, valbool);
1208 		break;
1209 
1210 	case SO_OOBINLINE:
1211 		sock_valbool_flag(sk, SOCK_URGINLINE, valbool);
1212 		break;
1213 
1214 	case SO_NO_CHECK:
1215 		sk->sk_no_check_tx = valbool;
1216 		break;
1217 
1218 	case SO_PRIORITY:
1219 		if ((val >= 0 && val <= 6) ||
1220 		    sockopt_ns_capable(sock_net(sk)->user_ns, CAP_NET_RAW) ||
1221 		    sockopt_ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
1222 			WRITE_ONCE(sk->sk_priority, val);
1223 		else
1224 			ret = -EPERM;
1225 		break;
1226 
1227 	case SO_LINGER:
1228 		if (optlen < sizeof(ling)) {
1229 			ret = -EINVAL;	/* 1003.1g */
1230 			break;
1231 		}
1232 		if (copy_from_sockptr(&ling, optval, sizeof(ling))) {
1233 			ret = -EFAULT;
1234 			break;
1235 		}
1236 		if (!ling.l_onoff) {
1237 			sock_reset_flag(sk, SOCK_LINGER);
1238 		} else {
1239 			unsigned long t_sec = ling.l_linger;
1240 
1241 			if (t_sec >= MAX_SCHEDULE_TIMEOUT / HZ)
1242 				WRITE_ONCE(sk->sk_lingertime, MAX_SCHEDULE_TIMEOUT);
1243 			else
1244 				WRITE_ONCE(sk->sk_lingertime, t_sec * HZ);
1245 			sock_set_flag(sk, SOCK_LINGER);
1246 		}
1247 		break;
1248 
1249 	case SO_BSDCOMPAT:
1250 		break;
1251 
1252 	case SO_PASSCRED:
1253 		assign_bit(SOCK_PASSCRED, &sock->flags, valbool);
1254 		break;
1255 
1256 	case SO_PASSPIDFD:
1257 		assign_bit(SOCK_PASSPIDFD, &sock->flags, valbool);
1258 		break;
1259 
1260 	case SO_TIMESTAMP_OLD:
1261 	case SO_TIMESTAMP_NEW:
1262 	case SO_TIMESTAMPNS_OLD:
1263 	case SO_TIMESTAMPNS_NEW:
1264 		sock_set_timestamp(sk, optname, valbool);
1265 		break;
1266 
1267 	case SO_TIMESTAMPING_NEW:
1268 	case SO_TIMESTAMPING_OLD:
1269 		if (optlen == sizeof(timestamping)) {
1270 			if (copy_from_sockptr(&timestamping, optval,
1271 					      sizeof(timestamping))) {
1272 				ret = -EFAULT;
1273 				break;
1274 			}
1275 		} else {
1276 			memset(&timestamping, 0, sizeof(timestamping));
1277 			timestamping.flags = val;
1278 		}
1279 		ret = sock_set_timestamping(sk, optname, timestamping);
1280 		break;
1281 
1282 	case SO_RCVLOWAT:
1283 		{
1284 		int (*set_rcvlowat)(struct sock *sk, int val) = NULL;
1285 
1286 		if (val < 0)
1287 			val = INT_MAX;
1288 		if (sock)
1289 			set_rcvlowat = READ_ONCE(sock->ops)->set_rcvlowat;
1290 		if (set_rcvlowat)
1291 			ret = set_rcvlowat(sk, val);
1292 		else
1293 			WRITE_ONCE(sk->sk_rcvlowat, val ? : 1);
1294 		break;
1295 		}
1296 	case SO_RCVTIMEO_OLD:
1297 	case SO_RCVTIMEO_NEW:
1298 		ret = sock_set_timeout(&sk->sk_rcvtimeo, optval,
1299 				       optlen, optname == SO_RCVTIMEO_OLD);
1300 		break;
1301 
1302 	case SO_SNDTIMEO_OLD:
1303 	case SO_SNDTIMEO_NEW:
1304 		ret = sock_set_timeout(&sk->sk_sndtimeo, optval,
1305 				       optlen, optname == SO_SNDTIMEO_OLD);
1306 		break;
1307 
1308 	case SO_ATTACH_FILTER: {
1309 		struct sock_fprog fprog;
1310 
1311 		ret = copy_bpf_fprog_from_user(&fprog, optval, optlen);
1312 		if (!ret)
1313 			ret = sk_attach_filter(&fprog, sk);
1314 		break;
1315 	}
1316 	case SO_ATTACH_BPF:
1317 		ret = -EINVAL;
1318 		if (optlen == sizeof(u32)) {
1319 			u32 ufd;
1320 
1321 			ret = -EFAULT;
1322 			if (copy_from_sockptr(&ufd, optval, sizeof(ufd)))
1323 				break;
1324 
1325 			ret = sk_attach_bpf(ufd, sk);
1326 		}
1327 		break;
1328 
1329 	case SO_ATTACH_REUSEPORT_CBPF: {
1330 		struct sock_fprog fprog;
1331 
1332 		ret = copy_bpf_fprog_from_user(&fprog, optval, optlen);
1333 		if (!ret)
1334 			ret = sk_reuseport_attach_filter(&fprog, sk);
1335 		break;
1336 	}
1337 	case SO_ATTACH_REUSEPORT_EBPF:
1338 		ret = -EINVAL;
1339 		if (optlen == sizeof(u32)) {
1340 			u32 ufd;
1341 
1342 			ret = -EFAULT;
1343 			if (copy_from_sockptr(&ufd, optval, sizeof(ufd)))
1344 				break;
1345 
1346 			ret = sk_reuseport_attach_bpf(ufd, sk);
1347 		}
1348 		break;
1349 
1350 	case SO_DETACH_REUSEPORT_BPF:
1351 		ret = reuseport_detach_prog(sk);
1352 		break;
1353 
1354 	case SO_DETACH_FILTER:
1355 		ret = sk_detach_filter(sk);
1356 		break;
1357 
1358 	case SO_LOCK_FILTER:
1359 		if (sock_flag(sk, SOCK_FILTER_LOCKED) && !valbool)
1360 			ret = -EPERM;
1361 		else
1362 			sock_valbool_flag(sk, SOCK_FILTER_LOCKED, valbool);
1363 		break;
1364 
1365 	case SO_PASSSEC:
1366 		assign_bit(SOCK_PASSSEC, &sock->flags, valbool);
1367 		break;
1368 	case SO_MARK:
1369 		if (!sockopt_ns_capable(sock_net(sk)->user_ns, CAP_NET_RAW) &&
1370 		    !sockopt_ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) {
1371 			ret = -EPERM;
1372 			break;
1373 		}
1374 
1375 		__sock_set_mark(sk, val);
1376 		break;
1377 	case SO_RCVMARK:
1378 		sock_valbool_flag(sk, SOCK_RCVMARK, valbool);
1379 		break;
1380 
1381 	case SO_RXQ_OVFL:
1382 		sock_valbool_flag(sk, SOCK_RXQ_OVFL, valbool);
1383 		break;
1384 
1385 	case SO_WIFI_STATUS:
1386 		sock_valbool_flag(sk, SOCK_WIFI_STATUS, valbool);
1387 		break;
1388 
1389 	case SO_PEEK_OFF:
1390 		{
1391 		int (*set_peek_off)(struct sock *sk, int val);
1392 
1393 		set_peek_off = READ_ONCE(sock->ops)->set_peek_off;
1394 		if (set_peek_off)
1395 			ret = set_peek_off(sk, val);
1396 		else
1397 			ret = -EOPNOTSUPP;
1398 		break;
1399 		}
1400 
1401 	case SO_NOFCS:
1402 		sock_valbool_flag(sk, SOCK_NOFCS, valbool);
1403 		break;
1404 
1405 	case SO_SELECT_ERR_QUEUE:
1406 		sock_valbool_flag(sk, SOCK_SELECT_ERR_QUEUE, valbool);
1407 		break;
1408 
1409 #ifdef CONFIG_NET_RX_BUSY_POLL
1410 	case SO_BUSY_POLL:
1411 		if (val < 0)
1412 			ret = -EINVAL;
1413 		else
1414 			WRITE_ONCE(sk->sk_ll_usec, val);
1415 		break;
1416 	case SO_PREFER_BUSY_POLL:
1417 		if (valbool && !sockopt_capable(CAP_NET_ADMIN))
1418 			ret = -EPERM;
1419 		else
1420 			WRITE_ONCE(sk->sk_prefer_busy_poll, valbool);
1421 		break;
1422 	case SO_BUSY_POLL_BUDGET:
1423 		if (val > READ_ONCE(sk->sk_busy_poll_budget) && !sockopt_capable(CAP_NET_ADMIN)) {
1424 			ret = -EPERM;
1425 		} else {
1426 			if (val < 0 || val > U16_MAX)
1427 				ret = -EINVAL;
1428 			else
1429 				WRITE_ONCE(sk->sk_busy_poll_budget, val);
1430 		}
1431 		break;
1432 #endif
1433 
1434 	case SO_MAX_PACING_RATE:
1435 		{
1436 		unsigned long ulval = (val == ~0U) ? ~0UL : (unsigned int)val;
1437 
1438 		if (sizeof(ulval) != sizeof(val) &&
1439 		    optlen >= sizeof(ulval) &&
1440 		    copy_from_sockptr(&ulval, optval, sizeof(ulval))) {
1441 			ret = -EFAULT;
1442 			break;
1443 		}
1444 		if (ulval != ~0UL)
1445 			cmpxchg(&sk->sk_pacing_status,
1446 				SK_PACING_NONE,
1447 				SK_PACING_NEEDED);
1448 		/* Pairs with READ_ONCE() from sk_getsockopt() */
1449 		WRITE_ONCE(sk->sk_max_pacing_rate, ulval);
1450 		sk->sk_pacing_rate = min(sk->sk_pacing_rate, ulval);
1451 		break;
1452 		}
1453 	case SO_INCOMING_CPU:
1454 		reuseport_update_incoming_cpu(sk, val);
1455 		break;
1456 
1457 	case SO_CNX_ADVICE:
1458 		if (val == 1)
1459 			dst_negative_advice(sk);
1460 		break;
1461 
1462 	case SO_ZEROCOPY:
1463 		if (sk->sk_family == PF_INET || sk->sk_family == PF_INET6) {
1464 			if (!(sk_is_tcp(sk) ||
1465 			      (sk->sk_type == SOCK_DGRAM &&
1466 			       sk->sk_protocol == IPPROTO_UDP)))
1467 				ret = -EOPNOTSUPP;
1468 		} else if (sk->sk_family != PF_RDS) {
1469 			ret = -EOPNOTSUPP;
1470 		}
1471 		if (!ret) {
1472 			if (val < 0 || val > 1)
1473 				ret = -EINVAL;
1474 			else
1475 				sock_valbool_flag(sk, SOCK_ZEROCOPY, valbool);
1476 		}
1477 		break;
1478 
1479 	case SO_TXTIME:
1480 		if (optlen != sizeof(struct sock_txtime)) {
1481 			ret = -EINVAL;
1482 			break;
1483 		} else if (copy_from_sockptr(&sk_txtime, optval,
1484 			   sizeof(struct sock_txtime))) {
1485 			ret = -EFAULT;
1486 			break;
1487 		} else if (sk_txtime.flags & ~SOF_TXTIME_FLAGS_MASK) {
1488 			ret = -EINVAL;
1489 			break;
1490 		}
1491 		/* CLOCK_MONOTONIC is only used by sch_fq, and this packet
1492 		 * scheduler has enough safe guards.
1493 		 */
1494 		if (sk_txtime.clockid != CLOCK_MONOTONIC &&
1495 		    !sockopt_ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) {
1496 			ret = -EPERM;
1497 			break;
1498 		}
1499 		sock_valbool_flag(sk, SOCK_TXTIME, true);
1500 		sk->sk_clockid = sk_txtime.clockid;
1501 		sk->sk_txtime_deadline_mode =
1502 			!!(sk_txtime.flags & SOF_TXTIME_DEADLINE_MODE);
1503 		sk->sk_txtime_report_errors =
1504 			!!(sk_txtime.flags & SOF_TXTIME_REPORT_ERRORS);
1505 		break;
1506 
1507 	case SO_BINDTOIFINDEX:
1508 		ret = sock_bindtoindex_locked(sk, val);
1509 		break;
1510 
1511 	case SO_BUF_LOCK:
1512 		if (val & ~SOCK_BUF_LOCK_MASK) {
1513 			ret = -EINVAL;
1514 			break;
1515 		}
1516 		sk->sk_userlocks = val | (sk->sk_userlocks &
1517 					  ~SOCK_BUF_LOCK_MASK);
1518 		break;
1519 
1520 	case SO_RESERVE_MEM:
1521 	{
1522 		int delta;
1523 
1524 		if (val < 0) {
1525 			ret = -EINVAL;
1526 			break;
1527 		}
1528 
1529 		delta = val - sk->sk_reserved_mem;
1530 		if (delta < 0)
1531 			sock_release_reserved_memory(sk, -delta);
1532 		else
1533 			ret = sock_reserve_memory(sk, delta);
1534 		break;
1535 	}
1536 
1537 	case SO_TXREHASH:
1538 		if (val < -1 || val > 1) {
1539 			ret = -EINVAL;
1540 			break;
1541 		}
1542 		if ((u8)val == SOCK_TXREHASH_DEFAULT)
1543 			val = READ_ONCE(sock_net(sk)->core.sysctl_txrehash);
1544 		/* Paired with READ_ONCE() in tcp_rtx_synack()
1545 		 * and sk_getsockopt().
1546 		 */
1547 		WRITE_ONCE(sk->sk_txrehash, (u8)val);
1548 		break;
1549 
1550 	default:
1551 		ret = -ENOPROTOOPT;
1552 		break;
1553 	}
1554 	sockopt_release_sock(sk);
1555 	return ret;
1556 }
1557 
1558 int sock_setsockopt(struct socket *sock, int level, int optname,
1559 		    sockptr_t optval, unsigned int optlen)
1560 {
1561 	return sk_setsockopt(sock->sk, level, optname,
1562 			     optval, optlen);
1563 }
1564 EXPORT_SYMBOL(sock_setsockopt);
1565 
1566 static const struct cred *sk_get_peer_cred(struct sock *sk)
1567 {
1568 	const struct cred *cred;
1569 
1570 	spin_lock(&sk->sk_peer_lock);
1571 	cred = get_cred(sk->sk_peer_cred);
1572 	spin_unlock(&sk->sk_peer_lock);
1573 
1574 	return cred;
1575 }
1576 
1577 static void cred_to_ucred(struct pid *pid, const struct cred *cred,
1578 			  struct ucred *ucred)
1579 {
1580 	ucred->pid = pid_vnr(pid);
1581 	ucred->uid = ucred->gid = -1;
1582 	if (cred) {
1583 		struct user_namespace *current_ns = current_user_ns();
1584 
1585 		ucred->uid = from_kuid_munged(current_ns, cred->euid);
1586 		ucred->gid = from_kgid_munged(current_ns, cred->egid);
1587 	}
1588 }
1589 
1590 static int groups_to_user(sockptr_t dst, const struct group_info *src)
1591 {
1592 	struct user_namespace *user_ns = current_user_ns();
1593 	int i;
1594 
1595 	for (i = 0; i < src->ngroups; i++) {
1596 		gid_t gid = from_kgid_munged(user_ns, src->gid[i]);
1597 
1598 		if (copy_to_sockptr_offset(dst, i * sizeof(gid), &gid, sizeof(gid)))
1599 			return -EFAULT;
1600 	}
1601 
1602 	return 0;
1603 }
1604 
1605 int sk_getsockopt(struct sock *sk, int level, int optname,
1606 		  sockptr_t optval, sockptr_t optlen)
1607 {
1608 	struct socket *sock = sk->sk_socket;
1609 
1610 	union {
1611 		int val;
1612 		u64 val64;
1613 		unsigned long ulval;
1614 		struct linger ling;
1615 		struct old_timeval32 tm32;
1616 		struct __kernel_old_timeval tm;
1617 		struct  __kernel_sock_timeval stm;
1618 		struct sock_txtime txtime;
1619 		struct so_timestamping timestamping;
1620 	} v;
1621 
1622 	int lv = sizeof(int);
1623 	int len;
1624 
1625 	if (copy_from_sockptr(&len, optlen, sizeof(int)))
1626 		return -EFAULT;
1627 	if (len < 0)
1628 		return -EINVAL;
1629 
1630 	memset(&v, 0, sizeof(v));
1631 
1632 	switch (optname) {
1633 	case SO_DEBUG:
1634 		v.val = sock_flag(sk, SOCK_DBG);
1635 		break;
1636 
1637 	case SO_DONTROUTE:
1638 		v.val = sock_flag(sk, SOCK_LOCALROUTE);
1639 		break;
1640 
1641 	case SO_BROADCAST:
1642 		v.val = sock_flag(sk, SOCK_BROADCAST);
1643 		break;
1644 
1645 	case SO_SNDBUF:
1646 		v.val = READ_ONCE(sk->sk_sndbuf);
1647 		break;
1648 
1649 	case SO_RCVBUF:
1650 		v.val = READ_ONCE(sk->sk_rcvbuf);
1651 		break;
1652 
1653 	case SO_REUSEADDR:
1654 		v.val = sk->sk_reuse;
1655 		break;
1656 
1657 	case SO_REUSEPORT:
1658 		v.val = sk->sk_reuseport;
1659 		break;
1660 
1661 	case SO_KEEPALIVE:
1662 		v.val = sock_flag(sk, SOCK_KEEPOPEN);
1663 		break;
1664 
1665 	case SO_TYPE:
1666 		v.val = sk->sk_type;
1667 		break;
1668 
1669 	case SO_PROTOCOL:
1670 		v.val = sk->sk_protocol;
1671 		break;
1672 
1673 	case SO_DOMAIN:
1674 		v.val = sk->sk_family;
1675 		break;
1676 
1677 	case SO_ERROR:
1678 		v.val = -sock_error(sk);
1679 		if (v.val == 0)
1680 			v.val = xchg(&sk->sk_err_soft, 0);
1681 		break;
1682 
1683 	case SO_OOBINLINE:
1684 		v.val = sock_flag(sk, SOCK_URGINLINE);
1685 		break;
1686 
1687 	case SO_NO_CHECK:
1688 		v.val = sk->sk_no_check_tx;
1689 		break;
1690 
1691 	case SO_PRIORITY:
1692 		v.val = READ_ONCE(sk->sk_priority);
1693 		break;
1694 
1695 	case SO_LINGER:
1696 		lv		= sizeof(v.ling);
1697 		v.ling.l_onoff	= sock_flag(sk, SOCK_LINGER);
1698 		v.ling.l_linger	= READ_ONCE(sk->sk_lingertime) / HZ;
1699 		break;
1700 
1701 	case SO_BSDCOMPAT:
1702 		break;
1703 
1704 	case SO_TIMESTAMP_OLD:
1705 		v.val = sock_flag(sk, SOCK_RCVTSTAMP) &&
1706 				!sock_flag(sk, SOCK_TSTAMP_NEW) &&
1707 				!sock_flag(sk, SOCK_RCVTSTAMPNS);
1708 		break;
1709 
1710 	case SO_TIMESTAMPNS_OLD:
1711 		v.val = sock_flag(sk, SOCK_RCVTSTAMPNS) && !sock_flag(sk, SOCK_TSTAMP_NEW);
1712 		break;
1713 
1714 	case SO_TIMESTAMP_NEW:
1715 		v.val = sock_flag(sk, SOCK_RCVTSTAMP) && sock_flag(sk, SOCK_TSTAMP_NEW);
1716 		break;
1717 
1718 	case SO_TIMESTAMPNS_NEW:
1719 		v.val = sock_flag(sk, SOCK_RCVTSTAMPNS) && sock_flag(sk, SOCK_TSTAMP_NEW);
1720 		break;
1721 
1722 	case SO_TIMESTAMPING_OLD:
1723 	case SO_TIMESTAMPING_NEW:
1724 		lv = sizeof(v.timestamping);
1725 		/* For the later-added case SO_TIMESTAMPING_NEW: Be strict about only
1726 		 * returning the flags when they were set through the same option.
1727 		 * Don't change the beviour for the old case SO_TIMESTAMPING_OLD.
1728 		 */
1729 		if (optname == SO_TIMESTAMPING_OLD || sock_flag(sk, SOCK_TSTAMP_NEW)) {
1730 			v.timestamping.flags = READ_ONCE(sk->sk_tsflags);
1731 			v.timestamping.bind_phc = READ_ONCE(sk->sk_bind_phc);
1732 		}
1733 		break;
1734 
1735 	case SO_RCVTIMEO_OLD:
1736 	case SO_RCVTIMEO_NEW:
1737 		lv = sock_get_timeout(READ_ONCE(sk->sk_rcvtimeo), &v,
1738 				      SO_RCVTIMEO_OLD == optname);
1739 		break;
1740 
1741 	case SO_SNDTIMEO_OLD:
1742 	case SO_SNDTIMEO_NEW:
1743 		lv = sock_get_timeout(READ_ONCE(sk->sk_sndtimeo), &v,
1744 				      SO_SNDTIMEO_OLD == optname);
1745 		break;
1746 
1747 	case SO_RCVLOWAT:
1748 		v.val = READ_ONCE(sk->sk_rcvlowat);
1749 		break;
1750 
1751 	case SO_SNDLOWAT:
1752 		v.val = 1;
1753 		break;
1754 
1755 	case SO_PASSCRED:
1756 		v.val = !!test_bit(SOCK_PASSCRED, &sock->flags);
1757 		break;
1758 
1759 	case SO_PASSPIDFD:
1760 		v.val = !!test_bit(SOCK_PASSPIDFD, &sock->flags);
1761 		break;
1762 
1763 	case SO_PEERCRED:
1764 	{
1765 		struct ucred peercred;
1766 		if (len > sizeof(peercred))
1767 			len = sizeof(peercred);
1768 
1769 		spin_lock(&sk->sk_peer_lock);
1770 		cred_to_ucred(sk->sk_peer_pid, sk->sk_peer_cred, &peercred);
1771 		spin_unlock(&sk->sk_peer_lock);
1772 
1773 		if (copy_to_sockptr(optval, &peercred, len))
1774 			return -EFAULT;
1775 		goto lenout;
1776 	}
1777 
1778 	case SO_PEERPIDFD:
1779 	{
1780 		struct pid *peer_pid;
1781 		struct file *pidfd_file = NULL;
1782 		int pidfd;
1783 
1784 		if (len > sizeof(pidfd))
1785 			len = sizeof(pidfd);
1786 
1787 		spin_lock(&sk->sk_peer_lock);
1788 		peer_pid = get_pid(sk->sk_peer_pid);
1789 		spin_unlock(&sk->sk_peer_lock);
1790 
1791 		if (!peer_pid)
1792 			return -ENODATA;
1793 
1794 		pidfd = pidfd_prepare(peer_pid, 0, &pidfd_file);
1795 		put_pid(peer_pid);
1796 		if (pidfd < 0)
1797 			return pidfd;
1798 
1799 		if (copy_to_sockptr(optval, &pidfd, len) ||
1800 		    copy_to_sockptr(optlen, &len, sizeof(int))) {
1801 			put_unused_fd(pidfd);
1802 			fput(pidfd_file);
1803 
1804 			return -EFAULT;
1805 		}
1806 
1807 		fd_install(pidfd, pidfd_file);
1808 		return 0;
1809 	}
1810 
1811 	case SO_PEERGROUPS:
1812 	{
1813 		const struct cred *cred;
1814 		int ret, n;
1815 
1816 		cred = sk_get_peer_cred(sk);
1817 		if (!cred)
1818 			return -ENODATA;
1819 
1820 		n = cred->group_info->ngroups;
1821 		if (len < n * sizeof(gid_t)) {
1822 			len = n * sizeof(gid_t);
1823 			put_cred(cred);
1824 			return copy_to_sockptr(optlen, &len, sizeof(int)) ? -EFAULT : -ERANGE;
1825 		}
1826 		len = n * sizeof(gid_t);
1827 
1828 		ret = groups_to_user(optval, cred->group_info);
1829 		put_cred(cred);
1830 		if (ret)
1831 			return ret;
1832 		goto lenout;
1833 	}
1834 
1835 	case SO_PEERNAME:
1836 	{
1837 		struct sockaddr_storage address;
1838 
1839 		lv = READ_ONCE(sock->ops)->getname(sock, (struct sockaddr *)&address, 2);
1840 		if (lv < 0)
1841 			return -ENOTCONN;
1842 		if (lv < len)
1843 			return -EINVAL;
1844 		if (copy_to_sockptr(optval, &address, len))
1845 			return -EFAULT;
1846 		goto lenout;
1847 	}
1848 
1849 	/* Dubious BSD thing... Probably nobody even uses it, but
1850 	 * the UNIX standard wants it for whatever reason... -DaveM
1851 	 */
1852 	case SO_ACCEPTCONN:
1853 		v.val = sk->sk_state == TCP_LISTEN;
1854 		break;
1855 
1856 	case SO_PASSSEC:
1857 		v.val = !!test_bit(SOCK_PASSSEC, &sock->flags);
1858 		break;
1859 
1860 	case SO_PEERSEC:
1861 		return security_socket_getpeersec_stream(sock,
1862 							 optval, optlen, len);
1863 
1864 	case SO_MARK:
1865 		v.val = READ_ONCE(sk->sk_mark);
1866 		break;
1867 
1868 	case SO_RCVMARK:
1869 		v.val = sock_flag(sk, SOCK_RCVMARK);
1870 		break;
1871 
1872 	case SO_RXQ_OVFL:
1873 		v.val = sock_flag(sk, SOCK_RXQ_OVFL);
1874 		break;
1875 
1876 	case SO_WIFI_STATUS:
1877 		v.val = sock_flag(sk, SOCK_WIFI_STATUS);
1878 		break;
1879 
1880 	case SO_PEEK_OFF:
1881 		if (!READ_ONCE(sock->ops)->set_peek_off)
1882 			return -EOPNOTSUPP;
1883 
1884 		v.val = READ_ONCE(sk->sk_peek_off);
1885 		break;
1886 	case SO_NOFCS:
1887 		v.val = sock_flag(sk, SOCK_NOFCS);
1888 		break;
1889 
1890 	case SO_BINDTODEVICE:
1891 		return sock_getbindtodevice(sk, optval, optlen, len);
1892 
1893 	case SO_GET_FILTER:
1894 		len = sk_get_filter(sk, optval, len);
1895 		if (len < 0)
1896 			return len;
1897 
1898 		goto lenout;
1899 
1900 	case SO_LOCK_FILTER:
1901 		v.val = sock_flag(sk, SOCK_FILTER_LOCKED);
1902 		break;
1903 
1904 	case SO_BPF_EXTENSIONS:
1905 		v.val = bpf_tell_extensions();
1906 		break;
1907 
1908 	case SO_SELECT_ERR_QUEUE:
1909 		v.val = sock_flag(sk, SOCK_SELECT_ERR_QUEUE);
1910 		break;
1911 
1912 #ifdef CONFIG_NET_RX_BUSY_POLL
1913 	case SO_BUSY_POLL:
1914 		v.val = READ_ONCE(sk->sk_ll_usec);
1915 		break;
1916 	case SO_PREFER_BUSY_POLL:
1917 		v.val = READ_ONCE(sk->sk_prefer_busy_poll);
1918 		break;
1919 #endif
1920 
1921 	case SO_MAX_PACING_RATE:
1922 		/* The READ_ONCE() pair with the WRITE_ONCE() in sk_setsockopt() */
1923 		if (sizeof(v.ulval) != sizeof(v.val) && len >= sizeof(v.ulval)) {
1924 			lv = sizeof(v.ulval);
1925 			v.ulval = READ_ONCE(sk->sk_max_pacing_rate);
1926 		} else {
1927 			/* 32bit version */
1928 			v.val = min_t(unsigned long, ~0U,
1929 				      READ_ONCE(sk->sk_max_pacing_rate));
1930 		}
1931 		break;
1932 
1933 	case SO_INCOMING_CPU:
1934 		v.val = READ_ONCE(sk->sk_incoming_cpu);
1935 		break;
1936 
1937 	case SO_MEMINFO:
1938 	{
1939 		u32 meminfo[SK_MEMINFO_VARS];
1940 
1941 		sk_get_meminfo(sk, meminfo);
1942 
1943 		len = min_t(unsigned int, len, sizeof(meminfo));
1944 		if (copy_to_sockptr(optval, &meminfo, len))
1945 			return -EFAULT;
1946 
1947 		goto lenout;
1948 	}
1949 
1950 #ifdef CONFIG_NET_RX_BUSY_POLL
1951 	case SO_INCOMING_NAPI_ID:
1952 		v.val = READ_ONCE(sk->sk_napi_id);
1953 
1954 		/* aggregate non-NAPI IDs down to 0 */
1955 		if (v.val < MIN_NAPI_ID)
1956 			v.val = 0;
1957 
1958 		break;
1959 #endif
1960 
1961 	case SO_COOKIE:
1962 		lv = sizeof(u64);
1963 		if (len < lv)
1964 			return -EINVAL;
1965 		v.val64 = sock_gen_cookie(sk);
1966 		break;
1967 
1968 	case SO_ZEROCOPY:
1969 		v.val = sock_flag(sk, SOCK_ZEROCOPY);
1970 		break;
1971 
1972 	case SO_TXTIME:
1973 		lv = sizeof(v.txtime);
1974 		v.txtime.clockid = sk->sk_clockid;
1975 		v.txtime.flags |= sk->sk_txtime_deadline_mode ?
1976 				  SOF_TXTIME_DEADLINE_MODE : 0;
1977 		v.txtime.flags |= sk->sk_txtime_report_errors ?
1978 				  SOF_TXTIME_REPORT_ERRORS : 0;
1979 		break;
1980 
1981 	case SO_BINDTOIFINDEX:
1982 		v.val = READ_ONCE(sk->sk_bound_dev_if);
1983 		break;
1984 
1985 	case SO_NETNS_COOKIE:
1986 		lv = sizeof(u64);
1987 		if (len != lv)
1988 			return -EINVAL;
1989 		v.val64 = sock_net(sk)->net_cookie;
1990 		break;
1991 
1992 	case SO_BUF_LOCK:
1993 		v.val = sk->sk_userlocks & SOCK_BUF_LOCK_MASK;
1994 		break;
1995 
1996 	case SO_RESERVE_MEM:
1997 		v.val = READ_ONCE(sk->sk_reserved_mem);
1998 		break;
1999 
2000 	case SO_TXREHASH:
2001 		/* Paired with WRITE_ONCE() in sk_setsockopt() */
2002 		v.val = READ_ONCE(sk->sk_txrehash);
2003 		break;
2004 
2005 	default:
2006 		/* We implement the SO_SNDLOWAT etc to not be settable
2007 		 * (1003.1g 7).
2008 		 */
2009 		return -ENOPROTOOPT;
2010 	}
2011 
2012 	if (len > lv)
2013 		len = lv;
2014 	if (copy_to_sockptr(optval, &v, len))
2015 		return -EFAULT;
2016 lenout:
2017 	if (copy_to_sockptr(optlen, &len, sizeof(int)))
2018 		return -EFAULT;
2019 	return 0;
2020 }
2021 
2022 int sock_getsockopt(struct socket *sock, int level, int optname,
2023 		    char __user *optval, int __user *optlen)
2024 {
2025 	return sk_getsockopt(sock->sk, level, optname,
2026 			     USER_SOCKPTR(optval),
2027 			     USER_SOCKPTR(optlen));
2028 }
2029 
2030 /*
2031  * Initialize an sk_lock.
2032  *
2033  * (We also register the sk_lock with the lock validator.)
2034  */
2035 static inline void sock_lock_init(struct sock *sk)
2036 {
2037 	if (sk->sk_kern_sock)
2038 		sock_lock_init_class_and_name(
2039 			sk,
2040 			af_family_kern_slock_key_strings[sk->sk_family],
2041 			af_family_kern_slock_keys + sk->sk_family,
2042 			af_family_kern_key_strings[sk->sk_family],
2043 			af_family_kern_keys + sk->sk_family);
2044 	else
2045 		sock_lock_init_class_and_name(
2046 			sk,
2047 			af_family_slock_key_strings[sk->sk_family],
2048 			af_family_slock_keys + sk->sk_family,
2049 			af_family_key_strings[sk->sk_family],
2050 			af_family_keys + sk->sk_family);
2051 }
2052 
2053 /*
2054  * Copy all fields from osk to nsk but nsk->sk_refcnt must not change yet,
2055  * even temporarly, because of RCU lookups. sk_node should also be left as is.
2056  * We must not copy fields between sk_dontcopy_begin and sk_dontcopy_end
2057  */
2058 static void sock_copy(struct sock *nsk, const struct sock *osk)
2059 {
2060 	const struct proto *prot = READ_ONCE(osk->sk_prot);
2061 #ifdef CONFIG_SECURITY_NETWORK
2062 	void *sptr = nsk->sk_security;
2063 #endif
2064 
2065 	/* If we move sk_tx_queue_mapping out of the private section,
2066 	 * we must check if sk_tx_queue_clear() is called after
2067 	 * sock_copy() in sk_clone_lock().
2068 	 */
2069 	BUILD_BUG_ON(offsetof(struct sock, sk_tx_queue_mapping) <
2070 		     offsetof(struct sock, sk_dontcopy_begin) ||
2071 		     offsetof(struct sock, sk_tx_queue_mapping) >=
2072 		     offsetof(struct sock, sk_dontcopy_end));
2073 
2074 	memcpy(nsk, osk, offsetof(struct sock, sk_dontcopy_begin));
2075 
2076 	memcpy(&nsk->sk_dontcopy_end, &osk->sk_dontcopy_end,
2077 	       prot->obj_size - offsetof(struct sock, sk_dontcopy_end));
2078 
2079 #ifdef CONFIG_SECURITY_NETWORK
2080 	nsk->sk_security = sptr;
2081 	security_sk_clone(osk, nsk);
2082 #endif
2083 }
2084 
2085 static struct sock *sk_prot_alloc(struct proto *prot, gfp_t priority,
2086 		int family)
2087 {
2088 	struct sock *sk;
2089 	struct kmem_cache *slab;
2090 
2091 	slab = prot->slab;
2092 	if (slab != NULL) {
2093 		sk = kmem_cache_alloc(slab, priority & ~__GFP_ZERO);
2094 		if (!sk)
2095 			return sk;
2096 		if (want_init_on_alloc(priority))
2097 			sk_prot_clear_nulls(sk, prot->obj_size);
2098 	} else
2099 		sk = kmalloc(prot->obj_size, priority);
2100 
2101 	if (sk != NULL) {
2102 		if (security_sk_alloc(sk, family, priority))
2103 			goto out_free;
2104 
2105 		if (!try_module_get(prot->owner))
2106 			goto out_free_sec;
2107 	}
2108 
2109 	return sk;
2110 
2111 out_free_sec:
2112 	security_sk_free(sk);
2113 out_free:
2114 	if (slab != NULL)
2115 		kmem_cache_free(slab, sk);
2116 	else
2117 		kfree(sk);
2118 	return NULL;
2119 }
2120 
2121 static void sk_prot_free(struct proto *prot, struct sock *sk)
2122 {
2123 	struct kmem_cache *slab;
2124 	struct module *owner;
2125 
2126 	owner = prot->owner;
2127 	slab = prot->slab;
2128 
2129 	cgroup_sk_free(&sk->sk_cgrp_data);
2130 	mem_cgroup_sk_free(sk);
2131 	security_sk_free(sk);
2132 	if (slab != NULL)
2133 		kmem_cache_free(slab, sk);
2134 	else
2135 		kfree(sk);
2136 	module_put(owner);
2137 }
2138 
2139 /**
2140  *	sk_alloc - All socket objects are allocated here
2141  *	@net: the applicable net namespace
2142  *	@family: protocol family
2143  *	@priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
2144  *	@prot: struct proto associated with this new sock instance
2145  *	@kern: is this to be a kernel socket?
2146  */
2147 struct sock *sk_alloc(struct net *net, int family, gfp_t priority,
2148 		      struct proto *prot, int kern)
2149 {
2150 	struct sock *sk;
2151 
2152 	sk = sk_prot_alloc(prot, priority | __GFP_ZERO, family);
2153 	if (sk) {
2154 		sk->sk_family = family;
2155 		/*
2156 		 * See comment in struct sock definition to understand
2157 		 * why we need sk_prot_creator -acme
2158 		 */
2159 		sk->sk_prot = sk->sk_prot_creator = prot;
2160 		sk->sk_kern_sock = kern;
2161 		sock_lock_init(sk);
2162 		sk->sk_net_refcnt = kern ? 0 : 1;
2163 		if (likely(sk->sk_net_refcnt)) {
2164 			get_net_track(net, &sk->ns_tracker, priority);
2165 			sock_inuse_add(net, 1);
2166 		} else {
2167 			__netns_tracker_alloc(net, &sk->ns_tracker,
2168 					      false, priority);
2169 		}
2170 
2171 		sock_net_set(sk, net);
2172 		refcount_set(&sk->sk_wmem_alloc, 1);
2173 
2174 		mem_cgroup_sk_alloc(sk);
2175 		cgroup_sk_alloc(&sk->sk_cgrp_data);
2176 		sock_update_classid(&sk->sk_cgrp_data);
2177 		sock_update_netprioidx(&sk->sk_cgrp_data);
2178 		sk_tx_queue_clear(sk);
2179 	}
2180 
2181 	return sk;
2182 }
2183 EXPORT_SYMBOL(sk_alloc);
2184 
2185 /* Sockets having SOCK_RCU_FREE will call this function after one RCU
2186  * grace period. This is the case for UDP sockets and TCP listeners.
2187  */
2188 static void __sk_destruct(struct rcu_head *head)
2189 {
2190 	struct sock *sk = container_of(head, struct sock, sk_rcu);
2191 	struct sk_filter *filter;
2192 
2193 	if (sk->sk_destruct)
2194 		sk->sk_destruct(sk);
2195 
2196 	filter = rcu_dereference_check(sk->sk_filter,
2197 				       refcount_read(&sk->sk_wmem_alloc) == 0);
2198 	if (filter) {
2199 		sk_filter_uncharge(sk, filter);
2200 		RCU_INIT_POINTER(sk->sk_filter, NULL);
2201 	}
2202 
2203 	sock_disable_timestamp(sk, SK_FLAGS_TIMESTAMP);
2204 
2205 #ifdef CONFIG_BPF_SYSCALL
2206 	bpf_sk_storage_free(sk);
2207 #endif
2208 
2209 	if (atomic_read(&sk->sk_omem_alloc))
2210 		pr_debug("%s: optmem leakage (%d bytes) detected\n",
2211 			 __func__, atomic_read(&sk->sk_omem_alloc));
2212 
2213 	if (sk->sk_frag.page) {
2214 		put_page(sk->sk_frag.page);
2215 		sk->sk_frag.page = NULL;
2216 	}
2217 
2218 	/* We do not need to acquire sk->sk_peer_lock, we are the last user. */
2219 	put_cred(sk->sk_peer_cred);
2220 	put_pid(sk->sk_peer_pid);
2221 
2222 	if (likely(sk->sk_net_refcnt))
2223 		put_net_track(sock_net(sk), &sk->ns_tracker);
2224 	else
2225 		__netns_tracker_free(sock_net(sk), &sk->ns_tracker, false);
2226 
2227 	sk_prot_free(sk->sk_prot_creator, sk);
2228 }
2229 
2230 void sk_destruct(struct sock *sk)
2231 {
2232 	bool use_call_rcu = sock_flag(sk, SOCK_RCU_FREE);
2233 
2234 	if (rcu_access_pointer(sk->sk_reuseport_cb)) {
2235 		reuseport_detach_sock(sk);
2236 		use_call_rcu = true;
2237 	}
2238 
2239 	if (use_call_rcu)
2240 		call_rcu(&sk->sk_rcu, __sk_destruct);
2241 	else
2242 		__sk_destruct(&sk->sk_rcu);
2243 }
2244 
2245 static void __sk_free(struct sock *sk)
2246 {
2247 	if (likely(sk->sk_net_refcnt))
2248 		sock_inuse_add(sock_net(sk), -1);
2249 
2250 	if (unlikely(sk->sk_net_refcnt && sock_diag_has_destroy_listeners(sk)))
2251 		sock_diag_broadcast_destroy(sk);
2252 	else
2253 		sk_destruct(sk);
2254 }
2255 
2256 void sk_free(struct sock *sk)
2257 {
2258 	/*
2259 	 * We subtract one from sk_wmem_alloc and can know if
2260 	 * some packets are still in some tx queue.
2261 	 * If not null, sock_wfree() will call __sk_free(sk) later
2262 	 */
2263 	if (refcount_dec_and_test(&sk->sk_wmem_alloc))
2264 		__sk_free(sk);
2265 }
2266 EXPORT_SYMBOL(sk_free);
2267 
2268 static void sk_init_common(struct sock *sk)
2269 {
2270 	skb_queue_head_init(&sk->sk_receive_queue);
2271 	skb_queue_head_init(&sk->sk_write_queue);
2272 	skb_queue_head_init(&sk->sk_error_queue);
2273 
2274 	rwlock_init(&sk->sk_callback_lock);
2275 	lockdep_set_class_and_name(&sk->sk_receive_queue.lock,
2276 			af_rlock_keys + sk->sk_family,
2277 			af_family_rlock_key_strings[sk->sk_family]);
2278 	lockdep_set_class_and_name(&sk->sk_write_queue.lock,
2279 			af_wlock_keys + sk->sk_family,
2280 			af_family_wlock_key_strings[sk->sk_family]);
2281 	lockdep_set_class_and_name(&sk->sk_error_queue.lock,
2282 			af_elock_keys + sk->sk_family,
2283 			af_family_elock_key_strings[sk->sk_family]);
2284 	lockdep_set_class_and_name(&sk->sk_callback_lock,
2285 			af_callback_keys + sk->sk_family,
2286 			af_family_clock_key_strings[sk->sk_family]);
2287 }
2288 
2289 /**
2290  *	sk_clone_lock - clone a socket, and lock its clone
2291  *	@sk: the socket to clone
2292  *	@priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
2293  *
2294  *	Caller must unlock socket even in error path (bh_unlock_sock(newsk))
2295  */
2296 struct sock *sk_clone_lock(const struct sock *sk, const gfp_t priority)
2297 {
2298 	struct proto *prot = READ_ONCE(sk->sk_prot);
2299 	struct sk_filter *filter;
2300 	bool is_charged = true;
2301 	struct sock *newsk;
2302 
2303 	newsk = sk_prot_alloc(prot, priority, sk->sk_family);
2304 	if (!newsk)
2305 		goto out;
2306 
2307 	sock_copy(newsk, sk);
2308 
2309 	newsk->sk_prot_creator = prot;
2310 
2311 	/* SANITY */
2312 	if (likely(newsk->sk_net_refcnt)) {
2313 		get_net_track(sock_net(newsk), &newsk->ns_tracker, priority);
2314 		sock_inuse_add(sock_net(newsk), 1);
2315 	} else {
2316 		/* Kernel sockets are not elevating the struct net refcount.
2317 		 * Instead, use a tracker to more easily detect if a layer
2318 		 * is not properly dismantling its kernel sockets at netns
2319 		 * destroy time.
2320 		 */
2321 		__netns_tracker_alloc(sock_net(newsk), &newsk->ns_tracker,
2322 				      false, priority);
2323 	}
2324 	sk_node_init(&newsk->sk_node);
2325 	sock_lock_init(newsk);
2326 	bh_lock_sock(newsk);
2327 	newsk->sk_backlog.head	= newsk->sk_backlog.tail = NULL;
2328 	newsk->sk_backlog.len = 0;
2329 
2330 	atomic_set(&newsk->sk_rmem_alloc, 0);
2331 
2332 	/* sk_wmem_alloc set to one (see sk_free() and sock_wfree()) */
2333 	refcount_set(&newsk->sk_wmem_alloc, 1);
2334 
2335 	atomic_set(&newsk->sk_omem_alloc, 0);
2336 	sk_init_common(newsk);
2337 
2338 	newsk->sk_dst_cache	= NULL;
2339 	newsk->sk_dst_pending_confirm = 0;
2340 	newsk->sk_wmem_queued	= 0;
2341 	newsk->sk_forward_alloc = 0;
2342 	newsk->sk_reserved_mem  = 0;
2343 	atomic_set(&newsk->sk_drops, 0);
2344 	newsk->sk_send_head	= NULL;
2345 	newsk->sk_userlocks	= sk->sk_userlocks & ~SOCK_BINDPORT_LOCK;
2346 	atomic_set(&newsk->sk_zckey, 0);
2347 
2348 	sock_reset_flag(newsk, SOCK_DONE);
2349 
2350 	/* sk->sk_memcg will be populated at accept() time */
2351 	newsk->sk_memcg = NULL;
2352 
2353 	cgroup_sk_clone(&newsk->sk_cgrp_data);
2354 
2355 	rcu_read_lock();
2356 	filter = rcu_dereference(sk->sk_filter);
2357 	if (filter != NULL)
2358 		/* though it's an empty new sock, the charging may fail
2359 		 * if sysctl_optmem_max was changed between creation of
2360 		 * original socket and cloning
2361 		 */
2362 		is_charged = sk_filter_charge(newsk, filter);
2363 	RCU_INIT_POINTER(newsk->sk_filter, filter);
2364 	rcu_read_unlock();
2365 
2366 	if (unlikely(!is_charged || xfrm_sk_clone_policy(newsk, sk))) {
2367 		/* We need to make sure that we don't uncharge the new
2368 		 * socket if we couldn't charge it in the first place
2369 		 * as otherwise we uncharge the parent's filter.
2370 		 */
2371 		if (!is_charged)
2372 			RCU_INIT_POINTER(newsk->sk_filter, NULL);
2373 		sk_free_unlock_clone(newsk);
2374 		newsk = NULL;
2375 		goto out;
2376 	}
2377 	RCU_INIT_POINTER(newsk->sk_reuseport_cb, NULL);
2378 
2379 	if (bpf_sk_storage_clone(sk, newsk)) {
2380 		sk_free_unlock_clone(newsk);
2381 		newsk = NULL;
2382 		goto out;
2383 	}
2384 
2385 	/* Clear sk_user_data if parent had the pointer tagged
2386 	 * as not suitable for copying when cloning.
2387 	 */
2388 	if (sk_user_data_is_nocopy(newsk))
2389 		newsk->sk_user_data = NULL;
2390 
2391 	newsk->sk_err	   = 0;
2392 	newsk->sk_err_soft = 0;
2393 	newsk->sk_priority = 0;
2394 	newsk->sk_incoming_cpu = raw_smp_processor_id();
2395 
2396 	/* Before updating sk_refcnt, we must commit prior changes to memory
2397 	 * (Documentation/RCU/rculist_nulls.rst for details)
2398 	 */
2399 	smp_wmb();
2400 	refcount_set(&newsk->sk_refcnt, 2);
2401 
2402 	sk_set_socket(newsk, NULL);
2403 	sk_tx_queue_clear(newsk);
2404 	RCU_INIT_POINTER(newsk->sk_wq, NULL);
2405 
2406 	if (newsk->sk_prot->sockets_allocated)
2407 		sk_sockets_allocated_inc(newsk);
2408 
2409 	if (sock_needs_netstamp(sk) && newsk->sk_flags & SK_FLAGS_TIMESTAMP)
2410 		net_enable_timestamp();
2411 out:
2412 	return newsk;
2413 }
2414 EXPORT_SYMBOL_GPL(sk_clone_lock);
2415 
2416 void sk_free_unlock_clone(struct sock *sk)
2417 {
2418 	/* It is still raw copy of parent, so invalidate
2419 	 * destructor and make plain sk_free() */
2420 	sk->sk_destruct = NULL;
2421 	bh_unlock_sock(sk);
2422 	sk_free(sk);
2423 }
2424 EXPORT_SYMBOL_GPL(sk_free_unlock_clone);
2425 
2426 static u32 sk_dst_gso_max_size(struct sock *sk, struct dst_entry *dst)
2427 {
2428 	bool is_ipv6 = false;
2429 	u32 max_size;
2430 
2431 #if IS_ENABLED(CONFIG_IPV6)
2432 	is_ipv6 = (sk->sk_family == AF_INET6 &&
2433 		   !ipv6_addr_v4mapped(&sk->sk_v6_rcv_saddr));
2434 #endif
2435 	/* pairs with the WRITE_ONCE() in netif_set_gso(_ipv4)_max_size() */
2436 	max_size = is_ipv6 ? READ_ONCE(dst->dev->gso_max_size) :
2437 			READ_ONCE(dst->dev->gso_ipv4_max_size);
2438 	if (max_size > GSO_LEGACY_MAX_SIZE && !sk_is_tcp(sk))
2439 		max_size = GSO_LEGACY_MAX_SIZE;
2440 
2441 	return max_size - (MAX_TCP_HEADER + 1);
2442 }
2443 
2444 void sk_setup_caps(struct sock *sk, struct dst_entry *dst)
2445 {
2446 	u32 max_segs = 1;
2447 
2448 	sk->sk_route_caps = dst->dev->features;
2449 	if (sk_is_tcp(sk))
2450 		sk->sk_route_caps |= NETIF_F_GSO;
2451 	if (sk->sk_route_caps & NETIF_F_GSO)
2452 		sk->sk_route_caps |= NETIF_F_GSO_SOFTWARE;
2453 	if (unlikely(sk->sk_gso_disabled))
2454 		sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
2455 	if (sk_can_gso(sk)) {
2456 		if (dst->header_len && !xfrm_dst_offload_ok(dst)) {
2457 			sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
2458 		} else {
2459 			sk->sk_route_caps |= NETIF_F_SG | NETIF_F_HW_CSUM;
2460 			sk->sk_gso_max_size = sk_dst_gso_max_size(sk, dst);
2461 			/* pairs with the WRITE_ONCE() in netif_set_gso_max_segs() */
2462 			max_segs = max_t(u32, READ_ONCE(dst->dev->gso_max_segs), 1);
2463 		}
2464 	}
2465 	sk->sk_gso_max_segs = max_segs;
2466 	sk_dst_set(sk, dst);
2467 }
2468 EXPORT_SYMBOL_GPL(sk_setup_caps);
2469 
2470 /*
2471  *	Simple resource managers for sockets.
2472  */
2473 
2474 
2475 /*
2476  * Write buffer destructor automatically called from kfree_skb.
2477  */
2478 void sock_wfree(struct sk_buff *skb)
2479 {
2480 	struct sock *sk = skb->sk;
2481 	unsigned int len = skb->truesize;
2482 	bool free;
2483 
2484 	if (!sock_flag(sk, SOCK_USE_WRITE_QUEUE)) {
2485 		if (sock_flag(sk, SOCK_RCU_FREE) &&
2486 		    sk->sk_write_space == sock_def_write_space) {
2487 			rcu_read_lock();
2488 			free = refcount_sub_and_test(len, &sk->sk_wmem_alloc);
2489 			sock_def_write_space_wfree(sk);
2490 			rcu_read_unlock();
2491 			if (unlikely(free))
2492 				__sk_free(sk);
2493 			return;
2494 		}
2495 
2496 		/*
2497 		 * Keep a reference on sk_wmem_alloc, this will be released
2498 		 * after sk_write_space() call
2499 		 */
2500 		WARN_ON(refcount_sub_and_test(len - 1, &sk->sk_wmem_alloc));
2501 		sk->sk_write_space(sk);
2502 		len = 1;
2503 	}
2504 	/*
2505 	 * if sk_wmem_alloc reaches 0, we must finish what sk_free()
2506 	 * could not do because of in-flight packets
2507 	 */
2508 	if (refcount_sub_and_test(len, &sk->sk_wmem_alloc))
2509 		__sk_free(sk);
2510 }
2511 EXPORT_SYMBOL(sock_wfree);
2512 
2513 /* This variant of sock_wfree() is used by TCP,
2514  * since it sets SOCK_USE_WRITE_QUEUE.
2515  */
2516 void __sock_wfree(struct sk_buff *skb)
2517 {
2518 	struct sock *sk = skb->sk;
2519 
2520 	if (refcount_sub_and_test(skb->truesize, &sk->sk_wmem_alloc))
2521 		__sk_free(sk);
2522 }
2523 
2524 void skb_set_owner_w(struct sk_buff *skb, struct sock *sk)
2525 {
2526 	skb_orphan(skb);
2527 	skb->sk = sk;
2528 #ifdef CONFIG_INET
2529 	if (unlikely(!sk_fullsock(sk))) {
2530 		skb->destructor = sock_edemux;
2531 		sock_hold(sk);
2532 		return;
2533 	}
2534 #endif
2535 	skb->destructor = sock_wfree;
2536 	skb_set_hash_from_sk(skb, sk);
2537 	/*
2538 	 * We used to take a refcount on sk, but following operation
2539 	 * is enough to guarantee sk_free() wont free this sock until
2540 	 * all in-flight packets are completed
2541 	 */
2542 	refcount_add(skb->truesize, &sk->sk_wmem_alloc);
2543 }
2544 EXPORT_SYMBOL(skb_set_owner_w);
2545 
2546 static bool can_skb_orphan_partial(const struct sk_buff *skb)
2547 {
2548 #ifdef CONFIG_TLS_DEVICE
2549 	/* Drivers depend on in-order delivery for crypto offload,
2550 	 * partial orphan breaks out-of-order-OK logic.
2551 	 */
2552 	if (skb->decrypted)
2553 		return false;
2554 #endif
2555 	return (skb->destructor == sock_wfree ||
2556 		(IS_ENABLED(CONFIG_INET) && skb->destructor == tcp_wfree));
2557 }
2558 
2559 /* This helper is used by netem, as it can hold packets in its
2560  * delay queue. We want to allow the owner socket to send more
2561  * packets, as if they were already TX completed by a typical driver.
2562  * But we also want to keep skb->sk set because some packet schedulers
2563  * rely on it (sch_fq for example).
2564  */
2565 void skb_orphan_partial(struct sk_buff *skb)
2566 {
2567 	if (skb_is_tcp_pure_ack(skb))
2568 		return;
2569 
2570 	if (can_skb_orphan_partial(skb) && skb_set_owner_sk_safe(skb, skb->sk))
2571 		return;
2572 
2573 	skb_orphan(skb);
2574 }
2575 EXPORT_SYMBOL(skb_orphan_partial);
2576 
2577 /*
2578  * Read buffer destructor automatically called from kfree_skb.
2579  */
2580 void sock_rfree(struct sk_buff *skb)
2581 {
2582 	struct sock *sk = skb->sk;
2583 	unsigned int len = skb->truesize;
2584 
2585 	atomic_sub(len, &sk->sk_rmem_alloc);
2586 	sk_mem_uncharge(sk, len);
2587 }
2588 EXPORT_SYMBOL(sock_rfree);
2589 
2590 /*
2591  * Buffer destructor for skbs that are not used directly in read or write
2592  * path, e.g. for error handler skbs. Automatically called from kfree_skb.
2593  */
2594 void sock_efree(struct sk_buff *skb)
2595 {
2596 	sock_put(skb->sk);
2597 }
2598 EXPORT_SYMBOL(sock_efree);
2599 
2600 /* Buffer destructor for prefetch/receive path where reference count may
2601  * not be held, e.g. for listen sockets.
2602  */
2603 #ifdef CONFIG_INET
2604 void sock_pfree(struct sk_buff *skb)
2605 {
2606 	if (sk_is_refcounted(skb->sk))
2607 		sock_gen_put(skb->sk);
2608 }
2609 EXPORT_SYMBOL(sock_pfree);
2610 #endif /* CONFIG_INET */
2611 
2612 kuid_t sock_i_uid(struct sock *sk)
2613 {
2614 	kuid_t uid;
2615 
2616 	read_lock_bh(&sk->sk_callback_lock);
2617 	uid = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_uid : GLOBAL_ROOT_UID;
2618 	read_unlock_bh(&sk->sk_callback_lock);
2619 	return uid;
2620 }
2621 EXPORT_SYMBOL(sock_i_uid);
2622 
2623 unsigned long __sock_i_ino(struct sock *sk)
2624 {
2625 	unsigned long ino;
2626 
2627 	read_lock(&sk->sk_callback_lock);
2628 	ino = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_ino : 0;
2629 	read_unlock(&sk->sk_callback_lock);
2630 	return ino;
2631 }
2632 EXPORT_SYMBOL(__sock_i_ino);
2633 
2634 unsigned long sock_i_ino(struct sock *sk)
2635 {
2636 	unsigned long ino;
2637 
2638 	local_bh_disable();
2639 	ino = __sock_i_ino(sk);
2640 	local_bh_enable();
2641 	return ino;
2642 }
2643 EXPORT_SYMBOL(sock_i_ino);
2644 
2645 /*
2646  * Allocate a skb from the socket's send buffer.
2647  */
2648 struct sk_buff *sock_wmalloc(struct sock *sk, unsigned long size, int force,
2649 			     gfp_t priority)
2650 {
2651 	if (force ||
2652 	    refcount_read(&sk->sk_wmem_alloc) < READ_ONCE(sk->sk_sndbuf)) {
2653 		struct sk_buff *skb = alloc_skb(size, priority);
2654 
2655 		if (skb) {
2656 			skb_set_owner_w(skb, sk);
2657 			return skb;
2658 		}
2659 	}
2660 	return NULL;
2661 }
2662 EXPORT_SYMBOL(sock_wmalloc);
2663 
2664 static void sock_ofree(struct sk_buff *skb)
2665 {
2666 	struct sock *sk = skb->sk;
2667 
2668 	atomic_sub(skb->truesize, &sk->sk_omem_alloc);
2669 }
2670 
2671 struct sk_buff *sock_omalloc(struct sock *sk, unsigned long size,
2672 			     gfp_t priority)
2673 {
2674 	struct sk_buff *skb;
2675 
2676 	/* small safe race: SKB_TRUESIZE may differ from final skb->truesize */
2677 	if (atomic_read(&sk->sk_omem_alloc) + SKB_TRUESIZE(size) >
2678 	    READ_ONCE(sysctl_optmem_max))
2679 		return NULL;
2680 
2681 	skb = alloc_skb(size, priority);
2682 	if (!skb)
2683 		return NULL;
2684 
2685 	atomic_add(skb->truesize, &sk->sk_omem_alloc);
2686 	skb->sk = sk;
2687 	skb->destructor = sock_ofree;
2688 	return skb;
2689 }
2690 
2691 /*
2692  * Allocate a memory block from the socket's option memory buffer.
2693  */
2694 void *sock_kmalloc(struct sock *sk, int size, gfp_t priority)
2695 {
2696 	int optmem_max = READ_ONCE(sysctl_optmem_max);
2697 
2698 	if ((unsigned int)size <= optmem_max &&
2699 	    atomic_read(&sk->sk_omem_alloc) + size < optmem_max) {
2700 		void *mem;
2701 		/* First do the add, to avoid the race if kmalloc
2702 		 * might sleep.
2703 		 */
2704 		atomic_add(size, &sk->sk_omem_alloc);
2705 		mem = kmalloc(size, priority);
2706 		if (mem)
2707 			return mem;
2708 		atomic_sub(size, &sk->sk_omem_alloc);
2709 	}
2710 	return NULL;
2711 }
2712 EXPORT_SYMBOL(sock_kmalloc);
2713 
2714 /* Free an option memory block. Note, we actually want the inline
2715  * here as this allows gcc to detect the nullify and fold away the
2716  * condition entirely.
2717  */
2718 static inline void __sock_kfree_s(struct sock *sk, void *mem, int size,
2719 				  const bool nullify)
2720 {
2721 	if (WARN_ON_ONCE(!mem))
2722 		return;
2723 	if (nullify)
2724 		kfree_sensitive(mem);
2725 	else
2726 		kfree(mem);
2727 	atomic_sub(size, &sk->sk_omem_alloc);
2728 }
2729 
2730 void sock_kfree_s(struct sock *sk, void *mem, int size)
2731 {
2732 	__sock_kfree_s(sk, mem, size, false);
2733 }
2734 EXPORT_SYMBOL(sock_kfree_s);
2735 
2736 void sock_kzfree_s(struct sock *sk, void *mem, int size)
2737 {
2738 	__sock_kfree_s(sk, mem, size, true);
2739 }
2740 EXPORT_SYMBOL(sock_kzfree_s);
2741 
2742 /* It is almost wait_for_tcp_memory minus release_sock/lock_sock.
2743    I think, these locks should be removed for datagram sockets.
2744  */
2745 static long sock_wait_for_wmem(struct sock *sk, long timeo)
2746 {
2747 	DEFINE_WAIT(wait);
2748 
2749 	sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
2750 	for (;;) {
2751 		if (!timeo)
2752 			break;
2753 		if (signal_pending(current))
2754 			break;
2755 		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
2756 		prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
2757 		if (refcount_read(&sk->sk_wmem_alloc) < READ_ONCE(sk->sk_sndbuf))
2758 			break;
2759 		if (READ_ONCE(sk->sk_shutdown) & SEND_SHUTDOWN)
2760 			break;
2761 		if (READ_ONCE(sk->sk_err))
2762 			break;
2763 		timeo = schedule_timeout(timeo);
2764 	}
2765 	finish_wait(sk_sleep(sk), &wait);
2766 	return timeo;
2767 }
2768 
2769 
2770 /*
2771  *	Generic send/receive buffer handlers
2772  */
2773 
2774 struct sk_buff *sock_alloc_send_pskb(struct sock *sk, unsigned long header_len,
2775 				     unsigned long data_len, int noblock,
2776 				     int *errcode, int max_page_order)
2777 {
2778 	struct sk_buff *skb;
2779 	long timeo;
2780 	int err;
2781 
2782 	timeo = sock_sndtimeo(sk, noblock);
2783 	for (;;) {
2784 		err = sock_error(sk);
2785 		if (err != 0)
2786 			goto failure;
2787 
2788 		err = -EPIPE;
2789 		if (READ_ONCE(sk->sk_shutdown) & SEND_SHUTDOWN)
2790 			goto failure;
2791 
2792 		if (sk_wmem_alloc_get(sk) < READ_ONCE(sk->sk_sndbuf))
2793 			break;
2794 
2795 		sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
2796 		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
2797 		err = -EAGAIN;
2798 		if (!timeo)
2799 			goto failure;
2800 		if (signal_pending(current))
2801 			goto interrupted;
2802 		timeo = sock_wait_for_wmem(sk, timeo);
2803 	}
2804 	skb = alloc_skb_with_frags(header_len, data_len, max_page_order,
2805 				   errcode, sk->sk_allocation);
2806 	if (skb)
2807 		skb_set_owner_w(skb, sk);
2808 	return skb;
2809 
2810 interrupted:
2811 	err = sock_intr_errno(timeo);
2812 failure:
2813 	*errcode = err;
2814 	return NULL;
2815 }
2816 EXPORT_SYMBOL(sock_alloc_send_pskb);
2817 
2818 int __sock_cmsg_send(struct sock *sk, struct cmsghdr *cmsg,
2819 		     struct sockcm_cookie *sockc)
2820 {
2821 	u32 tsflags;
2822 
2823 	switch (cmsg->cmsg_type) {
2824 	case SO_MARK:
2825 		if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_RAW) &&
2826 		    !ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
2827 			return -EPERM;
2828 		if (cmsg->cmsg_len != CMSG_LEN(sizeof(u32)))
2829 			return -EINVAL;
2830 		sockc->mark = *(u32 *)CMSG_DATA(cmsg);
2831 		break;
2832 	case SO_TIMESTAMPING_OLD:
2833 	case SO_TIMESTAMPING_NEW:
2834 		if (cmsg->cmsg_len != CMSG_LEN(sizeof(u32)))
2835 			return -EINVAL;
2836 
2837 		tsflags = *(u32 *)CMSG_DATA(cmsg);
2838 		if (tsflags & ~SOF_TIMESTAMPING_TX_RECORD_MASK)
2839 			return -EINVAL;
2840 
2841 		sockc->tsflags &= ~SOF_TIMESTAMPING_TX_RECORD_MASK;
2842 		sockc->tsflags |= tsflags;
2843 		break;
2844 	case SCM_TXTIME:
2845 		if (!sock_flag(sk, SOCK_TXTIME))
2846 			return -EINVAL;
2847 		if (cmsg->cmsg_len != CMSG_LEN(sizeof(u64)))
2848 			return -EINVAL;
2849 		sockc->transmit_time = get_unaligned((u64 *)CMSG_DATA(cmsg));
2850 		break;
2851 	/* SCM_RIGHTS and SCM_CREDENTIALS are semantically in SOL_UNIX. */
2852 	case SCM_RIGHTS:
2853 	case SCM_CREDENTIALS:
2854 		break;
2855 	default:
2856 		return -EINVAL;
2857 	}
2858 	return 0;
2859 }
2860 EXPORT_SYMBOL(__sock_cmsg_send);
2861 
2862 int sock_cmsg_send(struct sock *sk, struct msghdr *msg,
2863 		   struct sockcm_cookie *sockc)
2864 {
2865 	struct cmsghdr *cmsg;
2866 	int ret;
2867 
2868 	for_each_cmsghdr(cmsg, msg) {
2869 		if (!CMSG_OK(msg, cmsg))
2870 			return -EINVAL;
2871 		if (cmsg->cmsg_level != SOL_SOCKET)
2872 			continue;
2873 		ret = __sock_cmsg_send(sk, cmsg, sockc);
2874 		if (ret)
2875 			return ret;
2876 	}
2877 	return 0;
2878 }
2879 EXPORT_SYMBOL(sock_cmsg_send);
2880 
2881 static void sk_enter_memory_pressure(struct sock *sk)
2882 {
2883 	if (!sk->sk_prot->enter_memory_pressure)
2884 		return;
2885 
2886 	sk->sk_prot->enter_memory_pressure(sk);
2887 }
2888 
2889 static void sk_leave_memory_pressure(struct sock *sk)
2890 {
2891 	if (sk->sk_prot->leave_memory_pressure) {
2892 		INDIRECT_CALL_INET_1(sk->sk_prot->leave_memory_pressure,
2893 				     tcp_leave_memory_pressure, sk);
2894 	} else {
2895 		unsigned long *memory_pressure = sk->sk_prot->memory_pressure;
2896 
2897 		if (memory_pressure && READ_ONCE(*memory_pressure))
2898 			WRITE_ONCE(*memory_pressure, 0);
2899 	}
2900 }
2901 
2902 DEFINE_STATIC_KEY_FALSE(net_high_order_alloc_disable_key);
2903 
2904 /**
2905  * skb_page_frag_refill - check that a page_frag contains enough room
2906  * @sz: minimum size of the fragment we want to get
2907  * @pfrag: pointer to page_frag
2908  * @gfp: priority for memory allocation
2909  *
2910  * Note: While this allocator tries to use high order pages, there is
2911  * no guarantee that allocations succeed. Therefore, @sz MUST be
2912  * less or equal than PAGE_SIZE.
2913  */
2914 bool skb_page_frag_refill(unsigned int sz, struct page_frag *pfrag, gfp_t gfp)
2915 {
2916 	if (pfrag->page) {
2917 		if (page_ref_count(pfrag->page) == 1) {
2918 			pfrag->offset = 0;
2919 			return true;
2920 		}
2921 		if (pfrag->offset + sz <= pfrag->size)
2922 			return true;
2923 		put_page(pfrag->page);
2924 	}
2925 
2926 	pfrag->offset = 0;
2927 	if (SKB_FRAG_PAGE_ORDER &&
2928 	    !static_branch_unlikely(&net_high_order_alloc_disable_key)) {
2929 		/* Avoid direct reclaim but allow kswapd to wake */
2930 		pfrag->page = alloc_pages((gfp & ~__GFP_DIRECT_RECLAIM) |
2931 					  __GFP_COMP | __GFP_NOWARN |
2932 					  __GFP_NORETRY,
2933 					  SKB_FRAG_PAGE_ORDER);
2934 		if (likely(pfrag->page)) {
2935 			pfrag->size = PAGE_SIZE << SKB_FRAG_PAGE_ORDER;
2936 			return true;
2937 		}
2938 	}
2939 	pfrag->page = alloc_page(gfp);
2940 	if (likely(pfrag->page)) {
2941 		pfrag->size = PAGE_SIZE;
2942 		return true;
2943 	}
2944 	return false;
2945 }
2946 EXPORT_SYMBOL(skb_page_frag_refill);
2947 
2948 bool sk_page_frag_refill(struct sock *sk, struct page_frag *pfrag)
2949 {
2950 	if (likely(skb_page_frag_refill(32U, pfrag, sk->sk_allocation)))
2951 		return true;
2952 
2953 	sk_enter_memory_pressure(sk);
2954 	sk_stream_moderate_sndbuf(sk);
2955 	return false;
2956 }
2957 EXPORT_SYMBOL(sk_page_frag_refill);
2958 
2959 void __lock_sock(struct sock *sk)
2960 	__releases(&sk->sk_lock.slock)
2961 	__acquires(&sk->sk_lock.slock)
2962 {
2963 	DEFINE_WAIT(wait);
2964 
2965 	for (;;) {
2966 		prepare_to_wait_exclusive(&sk->sk_lock.wq, &wait,
2967 					TASK_UNINTERRUPTIBLE);
2968 		spin_unlock_bh(&sk->sk_lock.slock);
2969 		schedule();
2970 		spin_lock_bh(&sk->sk_lock.slock);
2971 		if (!sock_owned_by_user(sk))
2972 			break;
2973 	}
2974 	finish_wait(&sk->sk_lock.wq, &wait);
2975 }
2976 
2977 void __release_sock(struct sock *sk)
2978 	__releases(&sk->sk_lock.slock)
2979 	__acquires(&sk->sk_lock.slock)
2980 {
2981 	struct sk_buff *skb, *next;
2982 
2983 	while ((skb = sk->sk_backlog.head) != NULL) {
2984 		sk->sk_backlog.head = sk->sk_backlog.tail = NULL;
2985 
2986 		spin_unlock_bh(&sk->sk_lock.slock);
2987 
2988 		do {
2989 			next = skb->next;
2990 			prefetch(next);
2991 			DEBUG_NET_WARN_ON_ONCE(skb_dst_is_noref(skb));
2992 			skb_mark_not_on_list(skb);
2993 			sk_backlog_rcv(sk, skb);
2994 
2995 			cond_resched();
2996 
2997 			skb = next;
2998 		} while (skb != NULL);
2999 
3000 		spin_lock_bh(&sk->sk_lock.slock);
3001 	}
3002 
3003 	/*
3004 	 * Doing the zeroing here guarantee we can not loop forever
3005 	 * while a wild producer attempts to flood us.
3006 	 */
3007 	sk->sk_backlog.len = 0;
3008 }
3009 
3010 void __sk_flush_backlog(struct sock *sk)
3011 {
3012 	spin_lock_bh(&sk->sk_lock.slock);
3013 	__release_sock(sk);
3014 	spin_unlock_bh(&sk->sk_lock.slock);
3015 }
3016 EXPORT_SYMBOL_GPL(__sk_flush_backlog);
3017 
3018 /**
3019  * sk_wait_data - wait for data to arrive at sk_receive_queue
3020  * @sk:    sock to wait on
3021  * @timeo: for how long
3022  * @skb:   last skb seen on sk_receive_queue
3023  *
3024  * Now socket state including sk->sk_err is changed only under lock,
3025  * hence we may omit checks after joining wait queue.
3026  * We check receive queue before schedule() only as optimization;
3027  * it is very likely that release_sock() added new data.
3028  */
3029 int sk_wait_data(struct sock *sk, long *timeo, const struct sk_buff *skb)
3030 {
3031 	DEFINE_WAIT_FUNC(wait, woken_wake_function);
3032 	int rc;
3033 
3034 	add_wait_queue(sk_sleep(sk), &wait);
3035 	sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
3036 	rc = sk_wait_event(sk, timeo, skb_peek_tail(&sk->sk_receive_queue) != skb, &wait);
3037 	sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
3038 	remove_wait_queue(sk_sleep(sk), &wait);
3039 	return rc;
3040 }
3041 EXPORT_SYMBOL(sk_wait_data);
3042 
3043 /**
3044  *	__sk_mem_raise_allocated - increase memory_allocated
3045  *	@sk: socket
3046  *	@size: memory size to allocate
3047  *	@amt: pages to allocate
3048  *	@kind: allocation type
3049  *
3050  *	Similar to __sk_mem_schedule(), but does not update sk_forward_alloc
3051  */
3052 int __sk_mem_raise_allocated(struct sock *sk, int size, int amt, int kind)
3053 {
3054 	bool memcg_charge = mem_cgroup_sockets_enabled && sk->sk_memcg;
3055 	struct proto *prot = sk->sk_prot;
3056 	bool charged = true;
3057 	long allocated;
3058 
3059 	sk_memory_allocated_add(sk, amt);
3060 	allocated = sk_memory_allocated(sk);
3061 	if (memcg_charge &&
3062 	    !(charged = mem_cgroup_charge_skmem(sk->sk_memcg, amt,
3063 						gfp_memcg_charge())))
3064 		goto suppress_allocation;
3065 
3066 	/* Under limit. */
3067 	if (allocated <= sk_prot_mem_limits(sk, 0)) {
3068 		sk_leave_memory_pressure(sk);
3069 		return 1;
3070 	}
3071 
3072 	/* Under pressure. */
3073 	if (allocated > sk_prot_mem_limits(sk, 1))
3074 		sk_enter_memory_pressure(sk);
3075 
3076 	/* Over hard limit. */
3077 	if (allocated > sk_prot_mem_limits(sk, 2))
3078 		goto suppress_allocation;
3079 
3080 	/* guarantee minimum buffer size under pressure */
3081 	if (kind == SK_MEM_RECV) {
3082 		if (atomic_read(&sk->sk_rmem_alloc) < sk_get_rmem0(sk, prot))
3083 			return 1;
3084 
3085 	} else { /* SK_MEM_SEND */
3086 		int wmem0 = sk_get_wmem0(sk, prot);
3087 
3088 		if (sk->sk_type == SOCK_STREAM) {
3089 			if (sk->sk_wmem_queued < wmem0)
3090 				return 1;
3091 		} else if (refcount_read(&sk->sk_wmem_alloc) < wmem0) {
3092 				return 1;
3093 		}
3094 	}
3095 
3096 	if (sk_has_memory_pressure(sk)) {
3097 		u64 alloc;
3098 
3099 		if (!sk_under_memory_pressure(sk))
3100 			return 1;
3101 		alloc = sk_sockets_allocated_read_positive(sk);
3102 		if (sk_prot_mem_limits(sk, 2) > alloc *
3103 		    sk_mem_pages(sk->sk_wmem_queued +
3104 				 atomic_read(&sk->sk_rmem_alloc) +
3105 				 sk->sk_forward_alloc))
3106 			return 1;
3107 	}
3108 
3109 suppress_allocation:
3110 
3111 	if (kind == SK_MEM_SEND && sk->sk_type == SOCK_STREAM) {
3112 		sk_stream_moderate_sndbuf(sk);
3113 
3114 		/* Fail only if socket is _under_ its sndbuf.
3115 		 * In this case we cannot block, so that we have to fail.
3116 		 */
3117 		if (sk->sk_wmem_queued + size >= sk->sk_sndbuf) {
3118 			/* Force charge with __GFP_NOFAIL */
3119 			if (memcg_charge && !charged) {
3120 				mem_cgroup_charge_skmem(sk->sk_memcg, amt,
3121 					gfp_memcg_charge() | __GFP_NOFAIL);
3122 			}
3123 			return 1;
3124 		}
3125 	}
3126 
3127 	if (kind == SK_MEM_SEND || (kind == SK_MEM_RECV && charged))
3128 		trace_sock_exceed_buf_limit(sk, prot, allocated, kind);
3129 
3130 	sk_memory_allocated_sub(sk, amt);
3131 
3132 	if (memcg_charge && charged)
3133 		mem_cgroup_uncharge_skmem(sk->sk_memcg, amt);
3134 
3135 	return 0;
3136 }
3137 
3138 /**
3139  *	__sk_mem_schedule - increase sk_forward_alloc and memory_allocated
3140  *	@sk: socket
3141  *	@size: memory size to allocate
3142  *	@kind: allocation type
3143  *
3144  *	If kind is SK_MEM_SEND, it means wmem allocation. Otherwise it means
3145  *	rmem allocation. This function assumes that protocols which have
3146  *	memory_pressure use sk_wmem_queued as write buffer accounting.
3147  */
3148 int __sk_mem_schedule(struct sock *sk, int size, int kind)
3149 {
3150 	int ret, amt = sk_mem_pages(size);
3151 
3152 	sk_forward_alloc_add(sk, amt << PAGE_SHIFT);
3153 	ret = __sk_mem_raise_allocated(sk, size, amt, kind);
3154 	if (!ret)
3155 		sk_forward_alloc_add(sk, -(amt << PAGE_SHIFT));
3156 	return ret;
3157 }
3158 EXPORT_SYMBOL(__sk_mem_schedule);
3159 
3160 /**
3161  *	__sk_mem_reduce_allocated - reclaim memory_allocated
3162  *	@sk: socket
3163  *	@amount: number of quanta
3164  *
3165  *	Similar to __sk_mem_reclaim(), but does not update sk_forward_alloc
3166  */
3167 void __sk_mem_reduce_allocated(struct sock *sk, int amount)
3168 {
3169 	sk_memory_allocated_sub(sk, amount);
3170 
3171 	if (mem_cgroup_sockets_enabled && sk->sk_memcg)
3172 		mem_cgroup_uncharge_skmem(sk->sk_memcg, amount);
3173 
3174 	if (sk_under_global_memory_pressure(sk) &&
3175 	    (sk_memory_allocated(sk) < sk_prot_mem_limits(sk, 0)))
3176 		sk_leave_memory_pressure(sk);
3177 }
3178 
3179 /**
3180  *	__sk_mem_reclaim - reclaim sk_forward_alloc and memory_allocated
3181  *	@sk: socket
3182  *	@amount: number of bytes (rounded down to a PAGE_SIZE multiple)
3183  */
3184 void __sk_mem_reclaim(struct sock *sk, int amount)
3185 {
3186 	amount >>= PAGE_SHIFT;
3187 	sk_forward_alloc_add(sk, -(amount << PAGE_SHIFT));
3188 	__sk_mem_reduce_allocated(sk, amount);
3189 }
3190 EXPORT_SYMBOL(__sk_mem_reclaim);
3191 
3192 int sk_set_peek_off(struct sock *sk, int val)
3193 {
3194 	WRITE_ONCE(sk->sk_peek_off, val);
3195 	return 0;
3196 }
3197 EXPORT_SYMBOL_GPL(sk_set_peek_off);
3198 
3199 /*
3200  * Set of default routines for initialising struct proto_ops when
3201  * the protocol does not support a particular function. In certain
3202  * cases where it makes no sense for a protocol to have a "do nothing"
3203  * function, some default processing is provided.
3204  */
3205 
3206 int sock_no_bind(struct socket *sock, struct sockaddr *saddr, int len)
3207 {
3208 	return -EOPNOTSUPP;
3209 }
3210 EXPORT_SYMBOL(sock_no_bind);
3211 
3212 int sock_no_connect(struct socket *sock, struct sockaddr *saddr,
3213 		    int len, int flags)
3214 {
3215 	return -EOPNOTSUPP;
3216 }
3217 EXPORT_SYMBOL(sock_no_connect);
3218 
3219 int sock_no_socketpair(struct socket *sock1, struct socket *sock2)
3220 {
3221 	return -EOPNOTSUPP;
3222 }
3223 EXPORT_SYMBOL(sock_no_socketpair);
3224 
3225 int sock_no_accept(struct socket *sock, struct socket *newsock, int flags,
3226 		   bool kern)
3227 {
3228 	return -EOPNOTSUPP;
3229 }
3230 EXPORT_SYMBOL(sock_no_accept);
3231 
3232 int sock_no_getname(struct socket *sock, struct sockaddr *saddr,
3233 		    int peer)
3234 {
3235 	return -EOPNOTSUPP;
3236 }
3237 EXPORT_SYMBOL(sock_no_getname);
3238 
3239 int sock_no_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
3240 {
3241 	return -EOPNOTSUPP;
3242 }
3243 EXPORT_SYMBOL(sock_no_ioctl);
3244 
3245 int sock_no_listen(struct socket *sock, int backlog)
3246 {
3247 	return -EOPNOTSUPP;
3248 }
3249 EXPORT_SYMBOL(sock_no_listen);
3250 
3251 int sock_no_shutdown(struct socket *sock, int how)
3252 {
3253 	return -EOPNOTSUPP;
3254 }
3255 EXPORT_SYMBOL(sock_no_shutdown);
3256 
3257 int sock_no_sendmsg(struct socket *sock, struct msghdr *m, size_t len)
3258 {
3259 	return -EOPNOTSUPP;
3260 }
3261 EXPORT_SYMBOL(sock_no_sendmsg);
3262 
3263 int sock_no_sendmsg_locked(struct sock *sk, struct msghdr *m, size_t len)
3264 {
3265 	return -EOPNOTSUPP;
3266 }
3267 EXPORT_SYMBOL(sock_no_sendmsg_locked);
3268 
3269 int sock_no_recvmsg(struct socket *sock, struct msghdr *m, size_t len,
3270 		    int flags)
3271 {
3272 	return -EOPNOTSUPP;
3273 }
3274 EXPORT_SYMBOL(sock_no_recvmsg);
3275 
3276 int sock_no_mmap(struct file *file, struct socket *sock, struct vm_area_struct *vma)
3277 {
3278 	/* Mirror missing mmap method error code */
3279 	return -ENODEV;
3280 }
3281 EXPORT_SYMBOL(sock_no_mmap);
3282 
3283 /*
3284  * When a file is received (via SCM_RIGHTS, etc), we must bump the
3285  * various sock-based usage counts.
3286  */
3287 void __receive_sock(struct file *file)
3288 {
3289 	struct socket *sock;
3290 
3291 	sock = sock_from_file(file);
3292 	if (sock) {
3293 		sock_update_netprioidx(&sock->sk->sk_cgrp_data);
3294 		sock_update_classid(&sock->sk->sk_cgrp_data);
3295 	}
3296 }
3297 
3298 /*
3299  *	Default Socket Callbacks
3300  */
3301 
3302 static void sock_def_wakeup(struct sock *sk)
3303 {
3304 	struct socket_wq *wq;
3305 
3306 	rcu_read_lock();
3307 	wq = rcu_dereference(sk->sk_wq);
3308 	if (skwq_has_sleeper(wq))
3309 		wake_up_interruptible_all(&wq->wait);
3310 	rcu_read_unlock();
3311 }
3312 
3313 static void sock_def_error_report(struct sock *sk)
3314 {
3315 	struct socket_wq *wq;
3316 
3317 	rcu_read_lock();
3318 	wq = rcu_dereference(sk->sk_wq);
3319 	if (skwq_has_sleeper(wq))
3320 		wake_up_interruptible_poll(&wq->wait, EPOLLERR);
3321 	sk_wake_async(sk, SOCK_WAKE_IO, POLL_ERR);
3322 	rcu_read_unlock();
3323 }
3324 
3325 void sock_def_readable(struct sock *sk)
3326 {
3327 	struct socket_wq *wq;
3328 
3329 	trace_sk_data_ready(sk);
3330 
3331 	rcu_read_lock();
3332 	wq = rcu_dereference(sk->sk_wq);
3333 	if (skwq_has_sleeper(wq))
3334 		wake_up_interruptible_sync_poll(&wq->wait, EPOLLIN | EPOLLPRI |
3335 						EPOLLRDNORM | EPOLLRDBAND);
3336 	sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
3337 	rcu_read_unlock();
3338 }
3339 
3340 static void sock_def_write_space(struct sock *sk)
3341 {
3342 	struct socket_wq *wq;
3343 
3344 	rcu_read_lock();
3345 
3346 	/* Do not wake up a writer until he can make "significant"
3347 	 * progress.  --DaveM
3348 	 */
3349 	if (sock_writeable(sk)) {
3350 		wq = rcu_dereference(sk->sk_wq);
3351 		if (skwq_has_sleeper(wq))
3352 			wake_up_interruptible_sync_poll(&wq->wait, EPOLLOUT |
3353 						EPOLLWRNORM | EPOLLWRBAND);
3354 
3355 		/* Should agree with poll, otherwise some programs break */
3356 		sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
3357 	}
3358 
3359 	rcu_read_unlock();
3360 }
3361 
3362 /* An optimised version of sock_def_write_space(), should only be called
3363  * for SOCK_RCU_FREE sockets under RCU read section and after putting
3364  * ->sk_wmem_alloc.
3365  */
3366 static void sock_def_write_space_wfree(struct sock *sk)
3367 {
3368 	/* Do not wake up a writer until he can make "significant"
3369 	 * progress.  --DaveM
3370 	 */
3371 	if (sock_writeable(sk)) {
3372 		struct socket_wq *wq = rcu_dereference(sk->sk_wq);
3373 
3374 		/* rely on refcount_sub from sock_wfree() */
3375 		smp_mb__after_atomic();
3376 		if (wq && waitqueue_active(&wq->wait))
3377 			wake_up_interruptible_sync_poll(&wq->wait, EPOLLOUT |
3378 						EPOLLWRNORM | EPOLLWRBAND);
3379 
3380 		/* Should agree with poll, otherwise some programs break */
3381 		sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
3382 	}
3383 }
3384 
3385 static void sock_def_destruct(struct sock *sk)
3386 {
3387 }
3388 
3389 void sk_send_sigurg(struct sock *sk)
3390 {
3391 	if (sk->sk_socket && sk->sk_socket->file)
3392 		if (send_sigurg(&sk->sk_socket->file->f_owner))
3393 			sk_wake_async(sk, SOCK_WAKE_URG, POLL_PRI);
3394 }
3395 EXPORT_SYMBOL(sk_send_sigurg);
3396 
3397 void sk_reset_timer(struct sock *sk, struct timer_list* timer,
3398 		    unsigned long expires)
3399 {
3400 	if (!mod_timer(timer, expires))
3401 		sock_hold(sk);
3402 }
3403 EXPORT_SYMBOL(sk_reset_timer);
3404 
3405 void sk_stop_timer(struct sock *sk, struct timer_list* timer)
3406 {
3407 	if (del_timer(timer))
3408 		__sock_put(sk);
3409 }
3410 EXPORT_SYMBOL(sk_stop_timer);
3411 
3412 void sk_stop_timer_sync(struct sock *sk, struct timer_list *timer)
3413 {
3414 	if (del_timer_sync(timer))
3415 		__sock_put(sk);
3416 }
3417 EXPORT_SYMBOL(sk_stop_timer_sync);
3418 
3419 void sock_init_data_uid(struct socket *sock, struct sock *sk, kuid_t uid)
3420 {
3421 	sk_init_common(sk);
3422 	sk->sk_send_head	=	NULL;
3423 
3424 	timer_setup(&sk->sk_timer, NULL, 0);
3425 
3426 	sk->sk_allocation	=	GFP_KERNEL;
3427 	sk->sk_rcvbuf		=	READ_ONCE(sysctl_rmem_default);
3428 	sk->sk_sndbuf		=	READ_ONCE(sysctl_wmem_default);
3429 	sk->sk_state		=	TCP_CLOSE;
3430 	sk->sk_use_task_frag	=	true;
3431 	sk_set_socket(sk, sock);
3432 
3433 	sock_set_flag(sk, SOCK_ZAPPED);
3434 
3435 	if (sock) {
3436 		sk->sk_type	=	sock->type;
3437 		RCU_INIT_POINTER(sk->sk_wq, &sock->wq);
3438 		sock->sk	=	sk;
3439 	} else {
3440 		RCU_INIT_POINTER(sk->sk_wq, NULL);
3441 	}
3442 	sk->sk_uid	=	uid;
3443 
3444 	rwlock_init(&sk->sk_callback_lock);
3445 	if (sk->sk_kern_sock)
3446 		lockdep_set_class_and_name(
3447 			&sk->sk_callback_lock,
3448 			af_kern_callback_keys + sk->sk_family,
3449 			af_family_kern_clock_key_strings[sk->sk_family]);
3450 	else
3451 		lockdep_set_class_and_name(
3452 			&sk->sk_callback_lock,
3453 			af_callback_keys + sk->sk_family,
3454 			af_family_clock_key_strings[sk->sk_family]);
3455 
3456 	sk->sk_state_change	=	sock_def_wakeup;
3457 	sk->sk_data_ready	=	sock_def_readable;
3458 	sk->sk_write_space	=	sock_def_write_space;
3459 	sk->sk_error_report	=	sock_def_error_report;
3460 	sk->sk_destruct		=	sock_def_destruct;
3461 
3462 	sk->sk_frag.page	=	NULL;
3463 	sk->sk_frag.offset	=	0;
3464 	sk->sk_peek_off		=	-1;
3465 
3466 	sk->sk_peer_pid 	=	NULL;
3467 	sk->sk_peer_cred	=	NULL;
3468 	spin_lock_init(&sk->sk_peer_lock);
3469 
3470 	sk->sk_write_pending	=	0;
3471 	sk->sk_rcvlowat		=	1;
3472 	sk->sk_rcvtimeo		=	MAX_SCHEDULE_TIMEOUT;
3473 	sk->sk_sndtimeo		=	MAX_SCHEDULE_TIMEOUT;
3474 
3475 	sk->sk_stamp = SK_DEFAULT_STAMP;
3476 #if BITS_PER_LONG==32
3477 	seqlock_init(&sk->sk_stamp_seq);
3478 #endif
3479 	atomic_set(&sk->sk_zckey, 0);
3480 
3481 #ifdef CONFIG_NET_RX_BUSY_POLL
3482 	sk->sk_napi_id		=	0;
3483 	sk->sk_ll_usec		=	READ_ONCE(sysctl_net_busy_read);
3484 #endif
3485 
3486 	sk->sk_max_pacing_rate = ~0UL;
3487 	sk->sk_pacing_rate = ~0UL;
3488 	WRITE_ONCE(sk->sk_pacing_shift, 10);
3489 	sk->sk_incoming_cpu = -1;
3490 
3491 	sk_rx_queue_clear(sk);
3492 	/*
3493 	 * Before updating sk_refcnt, we must commit prior changes to memory
3494 	 * (Documentation/RCU/rculist_nulls.rst for details)
3495 	 */
3496 	smp_wmb();
3497 	refcount_set(&sk->sk_refcnt, 1);
3498 	atomic_set(&sk->sk_drops, 0);
3499 }
3500 EXPORT_SYMBOL(sock_init_data_uid);
3501 
3502 void sock_init_data(struct socket *sock, struct sock *sk)
3503 {
3504 	kuid_t uid = sock ?
3505 		SOCK_INODE(sock)->i_uid :
3506 		make_kuid(sock_net(sk)->user_ns, 0);
3507 
3508 	sock_init_data_uid(sock, sk, uid);
3509 }
3510 EXPORT_SYMBOL(sock_init_data);
3511 
3512 void lock_sock_nested(struct sock *sk, int subclass)
3513 {
3514 	/* The sk_lock has mutex_lock() semantics here. */
3515 	mutex_acquire(&sk->sk_lock.dep_map, subclass, 0, _RET_IP_);
3516 
3517 	might_sleep();
3518 	spin_lock_bh(&sk->sk_lock.slock);
3519 	if (sock_owned_by_user_nocheck(sk))
3520 		__lock_sock(sk);
3521 	sk->sk_lock.owned = 1;
3522 	spin_unlock_bh(&sk->sk_lock.slock);
3523 }
3524 EXPORT_SYMBOL(lock_sock_nested);
3525 
3526 void release_sock(struct sock *sk)
3527 {
3528 	spin_lock_bh(&sk->sk_lock.slock);
3529 	if (sk->sk_backlog.tail)
3530 		__release_sock(sk);
3531 
3532 	/* Warning : release_cb() might need to release sk ownership,
3533 	 * ie call sock_release_ownership(sk) before us.
3534 	 */
3535 	if (sk->sk_prot->release_cb)
3536 		sk->sk_prot->release_cb(sk);
3537 
3538 	sock_release_ownership(sk);
3539 	if (waitqueue_active(&sk->sk_lock.wq))
3540 		wake_up(&sk->sk_lock.wq);
3541 	spin_unlock_bh(&sk->sk_lock.slock);
3542 }
3543 EXPORT_SYMBOL(release_sock);
3544 
3545 bool __lock_sock_fast(struct sock *sk) __acquires(&sk->sk_lock.slock)
3546 {
3547 	might_sleep();
3548 	spin_lock_bh(&sk->sk_lock.slock);
3549 
3550 	if (!sock_owned_by_user_nocheck(sk)) {
3551 		/*
3552 		 * Fast path return with bottom halves disabled and
3553 		 * sock::sk_lock.slock held.
3554 		 *
3555 		 * The 'mutex' is not contended and holding
3556 		 * sock::sk_lock.slock prevents all other lockers to
3557 		 * proceed so the corresponding unlock_sock_fast() can
3558 		 * avoid the slow path of release_sock() completely and
3559 		 * just release slock.
3560 		 *
3561 		 * From a semantical POV this is equivalent to 'acquiring'
3562 		 * the 'mutex', hence the corresponding lockdep
3563 		 * mutex_release() has to happen in the fast path of
3564 		 * unlock_sock_fast().
3565 		 */
3566 		return false;
3567 	}
3568 
3569 	__lock_sock(sk);
3570 	sk->sk_lock.owned = 1;
3571 	__acquire(&sk->sk_lock.slock);
3572 	spin_unlock_bh(&sk->sk_lock.slock);
3573 	return true;
3574 }
3575 EXPORT_SYMBOL(__lock_sock_fast);
3576 
3577 int sock_gettstamp(struct socket *sock, void __user *userstamp,
3578 		   bool timeval, bool time32)
3579 {
3580 	struct sock *sk = sock->sk;
3581 	struct timespec64 ts;
3582 
3583 	sock_enable_timestamp(sk, SOCK_TIMESTAMP);
3584 	ts = ktime_to_timespec64(sock_read_timestamp(sk));
3585 	if (ts.tv_sec == -1)
3586 		return -ENOENT;
3587 	if (ts.tv_sec == 0) {
3588 		ktime_t kt = ktime_get_real();
3589 		sock_write_timestamp(sk, kt);
3590 		ts = ktime_to_timespec64(kt);
3591 	}
3592 
3593 	if (timeval)
3594 		ts.tv_nsec /= 1000;
3595 
3596 #ifdef CONFIG_COMPAT_32BIT_TIME
3597 	if (time32)
3598 		return put_old_timespec32(&ts, userstamp);
3599 #endif
3600 #ifdef CONFIG_SPARC64
3601 	/* beware of padding in sparc64 timeval */
3602 	if (timeval && !in_compat_syscall()) {
3603 		struct __kernel_old_timeval __user tv = {
3604 			.tv_sec = ts.tv_sec,
3605 			.tv_usec = ts.tv_nsec,
3606 		};
3607 		if (copy_to_user(userstamp, &tv, sizeof(tv)))
3608 			return -EFAULT;
3609 		return 0;
3610 	}
3611 #endif
3612 	return put_timespec64(&ts, userstamp);
3613 }
3614 EXPORT_SYMBOL(sock_gettstamp);
3615 
3616 void sock_enable_timestamp(struct sock *sk, enum sock_flags flag)
3617 {
3618 	if (!sock_flag(sk, flag)) {
3619 		unsigned long previous_flags = sk->sk_flags;
3620 
3621 		sock_set_flag(sk, flag);
3622 		/*
3623 		 * we just set one of the two flags which require net
3624 		 * time stamping, but time stamping might have been on
3625 		 * already because of the other one
3626 		 */
3627 		if (sock_needs_netstamp(sk) &&
3628 		    !(previous_flags & SK_FLAGS_TIMESTAMP))
3629 			net_enable_timestamp();
3630 	}
3631 }
3632 
3633 int sock_recv_errqueue(struct sock *sk, struct msghdr *msg, int len,
3634 		       int level, int type)
3635 {
3636 	struct sock_exterr_skb *serr;
3637 	struct sk_buff *skb;
3638 	int copied, err;
3639 
3640 	err = -EAGAIN;
3641 	skb = sock_dequeue_err_skb(sk);
3642 	if (skb == NULL)
3643 		goto out;
3644 
3645 	copied = skb->len;
3646 	if (copied > len) {
3647 		msg->msg_flags |= MSG_TRUNC;
3648 		copied = len;
3649 	}
3650 	err = skb_copy_datagram_msg(skb, 0, msg, copied);
3651 	if (err)
3652 		goto out_free_skb;
3653 
3654 	sock_recv_timestamp(msg, sk, skb);
3655 
3656 	serr = SKB_EXT_ERR(skb);
3657 	put_cmsg(msg, level, type, sizeof(serr->ee), &serr->ee);
3658 
3659 	msg->msg_flags |= MSG_ERRQUEUE;
3660 	err = copied;
3661 
3662 out_free_skb:
3663 	kfree_skb(skb);
3664 out:
3665 	return err;
3666 }
3667 EXPORT_SYMBOL(sock_recv_errqueue);
3668 
3669 /*
3670  *	Get a socket option on an socket.
3671  *
3672  *	FIX: POSIX 1003.1g is very ambiguous here. It states that
3673  *	asynchronous errors should be reported by getsockopt. We assume
3674  *	this means if you specify SO_ERROR (otherwise whats the point of it).
3675  */
3676 int sock_common_getsockopt(struct socket *sock, int level, int optname,
3677 			   char __user *optval, int __user *optlen)
3678 {
3679 	struct sock *sk = sock->sk;
3680 
3681 	/* IPV6_ADDRFORM can change sk->sk_prot under us. */
3682 	return READ_ONCE(sk->sk_prot)->getsockopt(sk, level, optname, optval, optlen);
3683 }
3684 EXPORT_SYMBOL(sock_common_getsockopt);
3685 
3686 int sock_common_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
3687 			int flags)
3688 {
3689 	struct sock *sk = sock->sk;
3690 	int addr_len = 0;
3691 	int err;
3692 
3693 	err = sk->sk_prot->recvmsg(sk, msg, size, flags, &addr_len);
3694 	if (err >= 0)
3695 		msg->msg_namelen = addr_len;
3696 	return err;
3697 }
3698 EXPORT_SYMBOL(sock_common_recvmsg);
3699 
3700 /*
3701  *	Set socket options on an inet socket.
3702  */
3703 int sock_common_setsockopt(struct socket *sock, int level, int optname,
3704 			   sockptr_t optval, unsigned int optlen)
3705 {
3706 	struct sock *sk = sock->sk;
3707 
3708 	/* IPV6_ADDRFORM can change sk->sk_prot under us. */
3709 	return READ_ONCE(sk->sk_prot)->setsockopt(sk, level, optname, optval, optlen);
3710 }
3711 EXPORT_SYMBOL(sock_common_setsockopt);
3712 
3713 void sk_common_release(struct sock *sk)
3714 {
3715 	if (sk->sk_prot->destroy)
3716 		sk->sk_prot->destroy(sk);
3717 
3718 	/*
3719 	 * Observation: when sk_common_release is called, processes have
3720 	 * no access to socket. But net still has.
3721 	 * Step one, detach it from networking:
3722 	 *
3723 	 * A. Remove from hash tables.
3724 	 */
3725 
3726 	sk->sk_prot->unhash(sk);
3727 
3728 	if (sk->sk_socket)
3729 		sk->sk_socket->sk = NULL;
3730 
3731 	/*
3732 	 * In this point socket cannot receive new packets, but it is possible
3733 	 * that some packets are in flight because some CPU runs receiver and
3734 	 * did hash table lookup before we unhashed socket. They will achieve
3735 	 * receive queue and will be purged by socket destructor.
3736 	 *
3737 	 * Also we still have packets pending on receive queue and probably,
3738 	 * our own packets waiting in device queues. sock_destroy will drain
3739 	 * receive queue, but transmitted packets will delay socket destruction
3740 	 * until the last reference will be released.
3741 	 */
3742 
3743 	sock_orphan(sk);
3744 
3745 	xfrm_sk_free_policy(sk);
3746 
3747 	sock_put(sk);
3748 }
3749 EXPORT_SYMBOL(sk_common_release);
3750 
3751 void sk_get_meminfo(const struct sock *sk, u32 *mem)
3752 {
3753 	memset(mem, 0, sizeof(*mem) * SK_MEMINFO_VARS);
3754 
3755 	mem[SK_MEMINFO_RMEM_ALLOC] = sk_rmem_alloc_get(sk);
3756 	mem[SK_MEMINFO_RCVBUF] = READ_ONCE(sk->sk_rcvbuf);
3757 	mem[SK_MEMINFO_WMEM_ALLOC] = sk_wmem_alloc_get(sk);
3758 	mem[SK_MEMINFO_SNDBUF] = READ_ONCE(sk->sk_sndbuf);
3759 	mem[SK_MEMINFO_FWD_ALLOC] = sk_forward_alloc_get(sk);
3760 	mem[SK_MEMINFO_WMEM_QUEUED] = READ_ONCE(sk->sk_wmem_queued);
3761 	mem[SK_MEMINFO_OPTMEM] = atomic_read(&sk->sk_omem_alloc);
3762 	mem[SK_MEMINFO_BACKLOG] = READ_ONCE(sk->sk_backlog.len);
3763 	mem[SK_MEMINFO_DROPS] = atomic_read(&sk->sk_drops);
3764 }
3765 
3766 #ifdef CONFIG_PROC_FS
3767 static DECLARE_BITMAP(proto_inuse_idx, PROTO_INUSE_NR);
3768 
3769 int sock_prot_inuse_get(struct net *net, struct proto *prot)
3770 {
3771 	int cpu, idx = prot->inuse_idx;
3772 	int res = 0;
3773 
3774 	for_each_possible_cpu(cpu)
3775 		res += per_cpu_ptr(net->core.prot_inuse, cpu)->val[idx];
3776 
3777 	return res >= 0 ? res : 0;
3778 }
3779 EXPORT_SYMBOL_GPL(sock_prot_inuse_get);
3780 
3781 int sock_inuse_get(struct net *net)
3782 {
3783 	int cpu, res = 0;
3784 
3785 	for_each_possible_cpu(cpu)
3786 		res += per_cpu_ptr(net->core.prot_inuse, cpu)->all;
3787 
3788 	return res;
3789 }
3790 
3791 EXPORT_SYMBOL_GPL(sock_inuse_get);
3792 
3793 static int __net_init sock_inuse_init_net(struct net *net)
3794 {
3795 	net->core.prot_inuse = alloc_percpu(struct prot_inuse);
3796 	if (net->core.prot_inuse == NULL)
3797 		return -ENOMEM;
3798 	return 0;
3799 }
3800 
3801 static void __net_exit sock_inuse_exit_net(struct net *net)
3802 {
3803 	free_percpu(net->core.prot_inuse);
3804 }
3805 
3806 static struct pernet_operations net_inuse_ops = {
3807 	.init = sock_inuse_init_net,
3808 	.exit = sock_inuse_exit_net,
3809 };
3810 
3811 static __init int net_inuse_init(void)
3812 {
3813 	if (register_pernet_subsys(&net_inuse_ops))
3814 		panic("Cannot initialize net inuse counters");
3815 
3816 	return 0;
3817 }
3818 
3819 core_initcall(net_inuse_init);
3820 
3821 static int assign_proto_idx(struct proto *prot)
3822 {
3823 	prot->inuse_idx = find_first_zero_bit(proto_inuse_idx, PROTO_INUSE_NR);
3824 
3825 	if (unlikely(prot->inuse_idx == PROTO_INUSE_NR - 1)) {
3826 		pr_err("PROTO_INUSE_NR exhausted\n");
3827 		return -ENOSPC;
3828 	}
3829 
3830 	set_bit(prot->inuse_idx, proto_inuse_idx);
3831 	return 0;
3832 }
3833 
3834 static void release_proto_idx(struct proto *prot)
3835 {
3836 	if (prot->inuse_idx != PROTO_INUSE_NR - 1)
3837 		clear_bit(prot->inuse_idx, proto_inuse_idx);
3838 }
3839 #else
3840 static inline int assign_proto_idx(struct proto *prot)
3841 {
3842 	return 0;
3843 }
3844 
3845 static inline void release_proto_idx(struct proto *prot)
3846 {
3847 }
3848 
3849 #endif
3850 
3851 static void tw_prot_cleanup(struct timewait_sock_ops *twsk_prot)
3852 {
3853 	if (!twsk_prot)
3854 		return;
3855 	kfree(twsk_prot->twsk_slab_name);
3856 	twsk_prot->twsk_slab_name = NULL;
3857 	kmem_cache_destroy(twsk_prot->twsk_slab);
3858 	twsk_prot->twsk_slab = NULL;
3859 }
3860 
3861 static int tw_prot_init(const struct proto *prot)
3862 {
3863 	struct timewait_sock_ops *twsk_prot = prot->twsk_prot;
3864 
3865 	if (!twsk_prot)
3866 		return 0;
3867 
3868 	twsk_prot->twsk_slab_name = kasprintf(GFP_KERNEL, "tw_sock_%s",
3869 					      prot->name);
3870 	if (!twsk_prot->twsk_slab_name)
3871 		return -ENOMEM;
3872 
3873 	twsk_prot->twsk_slab =
3874 		kmem_cache_create(twsk_prot->twsk_slab_name,
3875 				  twsk_prot->twsk_obj_size, 0,
3876 				  SLAB_ACCOUNT | prot->slab_flags,
3877 				  NULL);
3878 	if (!twsk_prot->twsk_slab) {
3879 		pr_crit("%s: Can't create timewait sock SLAB cache!\n",
3880 			prot->name);
3881 		return -ENOMEM;
3882 	}
3883 
3884 	return 0;
3885 }
3886 
3887 static void req_prot_cleanup(struct request_sock_ops *rsk_prot)
3888 {
3889 	if (!rsk_prot)
3890 		return;
3891 	kfree(rsk_prot->slab_name);
3892 	rsk_prot->slab_name = NULL;
3893 	kmem_cache_destroy(rsk_prot->slab);
3894 	rsk_prot->slab = NULL;
3895 }
3896 
3897 static int req_prot_init(const struct proto *prot)
3898 {
3899 	struct request_sock_ops *rsk_prot = prot->rsk_prot;
3900 
3901 	if (!rsk_prot)
3902 		return 0;
3903 
3904 	rsk_prot->slab_name = kasprintf(GFP_KERNEL, "request_sock_%s",
3905 					prot->name);
3906 	if (!rsk_prot->slab_name)
3907 		return -ENOMEM;
3908 
3909 	rsk_prot->slab = kmem_cache_create(rsk_prot->slab_name,
3910 					   rsk_prot->obj_size, 0,
3911 					   SLAB_ACCOUNT | prot->slab_flags,
3912 					   NULL);
3913 
3914 	if (!rsk_prot->slab) {
3915 		pr_crit("%s: Can't create request sock SLAB cache!\n",
3916 			prot->name);
3917 		return -ENOMEM;
3918 	}
3919 	return 0;
3920 }
3921 
3922 int proto_register(struct proto *prot, int alloc_slab)
3923 {
3924 	int ret = -ENOBUFS;
3925 
3926 	if (prot->memory_allocated && !prot->sysctl_mem) {
3927 		pr_err("%s: missing sysctl_mem\n", prot->name);
3928 		return -EINVAL;
3929 	}
3930 	if (prot->memory_allocated && !prot->per_cpu_fw_alloc) {
3931 		pr_err("%s: missing per_cpu_fw_alloc\n", prot->name);
3932 		return -EINVAL;
3933 	}
3934 	if (alloc_slab) {
3935 		prot->slab = kmem_cache_create_usercopy(prot->name,
3936 					prot->obj_size, 0,
3937 					SLAB_HWCACHE_ALIGN | SLAB_ACCOUNT |
3938 					prot->slab_flags,
3939 					prot->useroffset, prot->usersize,
3940 					NULL);
3941 
3942 		if (prot->slab == NULL) {
3943 			pr_crit("%s: Can't create sock SLAB cache!\n",
3944 				prot->name);
3945 			goto out;
3946 		}
3947 
3948 		if (req_prot_init(prot))
3949 			goto out_free_request_sock_slab;
3950 
3951 		if (tw_prot_init(prot))
3952 			goto out_free_timewait_sock_slab;
3953 	}
3954 
3955 	mutex_lock(&proto_list_mutex);
3956 	ret = assign_proto_idx(prot);
3957 	if (ret) {
3958 		mutex_unlock(&proto_list_mutex);
3959 		goto out_free_timewait_sock_slab;
3960 	}
3961 	list_add(&prot->node, &proto_list);
3962 	mutex_unlock(&proto_list_mutex);
3963 	return ret;
3964 
3965 out_free_timewait_sock_slab:
3966 	if (alloc_slab)
3967 		tw_prot_cleanup(prot->twsk_prot);
3968 out_free_request_sock_slab:
3969 	if (alloc_slab) {
3970 		req_prot_cleanup(prot->rsk_prot);
3971 
3972 		kmem_cache_destroy(prot->slab);
3973 		prot->slab = NULL;
3974 	}
3975 out:
3976 	return ret;
3977 }
3978 EXPORT_SYMBOL(proto_register);
3979 
3980 void proto_unregister(struct proto *prot)
3981 {
3982 	mutex_lock(&proto_list_mutex);
3983 	release_proto_idx(prot);
3984 	list_del(&prot->node);
3985 	mutex_unlock(&proto_list_mutex);
3986 
3987 	kmem_cache_destroy(prot->slab);
3988 	prot->slab = NULL;
3989 
3990 	req_prot_cleanup(prot->rsk_prot);
3991 	tw_prot_cleanup(prot->twsk_prot);
3992 }
3993 EXPORT_SYMBOL(proto_unregister);
3994 
3995 int sock_load_diag_module(int family, int protocol)
3996 {
3997 	if (!protocol) {
3998 		if (!sock_is_registered(family))
3999 			return -ENOENT;
4000 
4001 		return request_module("net-pf-%d-proto-%d-type-%d", PF_NETLINK,
4002 				      NETLINK_SOCK_DIAG, family);
4003 	}
4004 
4005 #ifdef CONFIG_INET
4006 	if (family == AF_INET &&
4007 	    protocol != IPPROTO_RAW &&
4008 	    protocol < MAX_INET_PROTOS &&
4009 	    !rcu_access_pointer(inet_protos[protocol]))
4010 		return -ENOENT;
4011 #endif
4012 
4013 	return request_module("net-pf-%d-proto-%d-type-%d-%d", PF_NETLINK,
4014 			      NETLINK_SOCK_DIAG, family, protocol);
4015 }
4016 EXPORT_SYMBOL(sock_load_diag_module);
4017 
4018 #ifdef CONFIG_PROC_FS
4019 static void *proto_seq_start(struct seq_file *seq, loff_t *pos)
4020 	__acquires(proto_list_mutex)
4021 {
4022 	mutex_lock(&proto_list_mutex);
4023 	return seq_list_start_head(&proto_list, *pos);
4024 }
4025 
4026 static void *proto_seq_next(struct seq_file *seq, void *v, loff_t *pos)
4027 {
4028 	return seq_list_next(v, &proto_list, pos);
4029 }
4030 
4031 static void proto_seq_stop(struct seq_file *seq, void *v)
4032 	__releases(proto_list_mutex)
4033 {
4034 	mutex_unlock(&proto_list_mutex);
4035 }
4036 
4037 static char proto_method_implemented(const void *method)
4038 {
4039 	return method == NULL ? 'n' : 'y';
4040 }
4041 static long sock_prot_memory_allocated(struct proto *proto)
4042 {
4043 	return proto->memory_allocated != NULL ? proto_memory_allocated(proto) : -1L;
4044 }
4045 
4046 static const char *sock_prot_memory_pressure(struct proto *proto)
4047 {
4048 	return proto->memory_pressure != NULL ?
4049 	proto_memory_pressure(proto) ? "yes" : "no" : "NI";
4050 }
4051 
4052 static void proto_seq_printf(struct seq_file *seq, struct proto *proto)
4053 {
4054 
4055 	seq_printf(seq, "%-9s %4u %6d  %6ld   %-3s %6u   %-3s  %-10s "
4056 			"%2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c\n",
4057 		   proto->name,
4058 		   proto->obj_size,
4059 		   sock_prot_inuse_get(seq_file_net(seq), proto),
4060 		   sock_prot_memory_allocated(proto),
4061 		   sock_prot_memory_pressure(proto),
4062 		   proto->max_header,
4063 		   proto->slab == NULL ? "no" : "yes",
4064 		   module_name(proto->owner),
4065 		   proto_method_implemented(proto->close),
4066 		   proto_method_implemented(proto->connect),
4067 		   proto_method_implemented(proto->disconnect),
4068 		   proto_method_implemented(proto->accept),
4069 		   proto_method_implemented(proto->ioctl),
4070 		   proto_method_implemented(proto->init),
4071 		   proto_method_implemented(proto->destroy),
4072 		   proto_method_implemented(proto->shutdown),
4073 		   proto_method_implemented(proto->setsockopt),
4074 		   proto_method_implemented(proto->getsockopt),
4075 		   proto_method_implemented(proto->sendmsg),
4076 		   proto_method_implemented(proto->recvmsg),
4077 		   proto_method_implemented(proto->bind),
4078 		   proto_method_implemented(proto->backlog_rcv),
4079 		   proto_method_implemented(proto->hash),
4080 		   proto_method_implemented(proto->unhash),
4081 		   proto_method_implemented(proto->get_port),
4082 		   proto_method_implemented(proto->enter_memory_pressure));
4083 }
4084 
4085 static int proto_seq_show(struct seq_file *seq, void *v)
4086 {
4087 	if (v == &proto_list)
4088 		seq_printf(seq, "%-9s %-4s %-8s %-6s %-5s %-7s %-4s %-10s %s",
4089 			   "protocol",
4090 			   "size",
4091 			   "sockets",
4092 			   "memory",
4093 			   "press",
4094 			   "maxhdr",
4095 			   "slab",
4096 			   "module",
4097 			   "cl co di ac io in de sh ss gs se re bi br ha uh gp em\n");
4098 	else
4099 		proto_seq_printf(seq, list_entry(v, struct proto, node));
4100 	return 0;
4101 }
4102 
4103 static const struct seq_operations proto_seq_ops = {
4104 	.start  = proto_seq_start,
4105 	.next   = proto_seq_next,
4106 	.stop   = proto_seq_stop,
4107 	.show   = proto_seq_show,
4108 };
4109 
4110 static __net_init int proto_init_net(struct net *net)
4111 {
4112 	if (!proc_create_net("protocols", 0444, net->proc_net, &proto_seq_ops,
4113 			sizeof(struct seq_net_private)))
4114 		return -ENOMEM;
4115 
4116 	return 0;
4117 }
4118 
4119 static __net_exit void proto_exit_net(struct net *net)
4120 {
4121 	remove_proc_entry("protocols", net->proc_net);
4122 }
4123 
4124 
4125 static __net_initdata struct pernet_operations proto_net_ops = {
4126 	.init = proto_init_net,
4127 	.exit = proto_exit_net,
4128 };
4129 
4130 static int __init proto_init(void)
4131 {
4132 	return register_pernet_subsys(&proto_net_ops);
4133 }
4134 
4135 subsys_initcall(proto_init);
4136 
4137 #endif /* PROC_FS */
4138 
4139 #ifdef CONFIG_NET_RX_BUSY_POLL
4140 bool sk_busy_loop_end(void *p, unsigned long start_time)
4141 {
4142 	struct sock *sk = p;
4143 
4144 	if (!skb_queue_empty_lockless(&sk->sk_receive_queue))
4145 		return true;
4146 
4147 	if (sk_is_udp(sk) &&
4148 	    !skb_queue_empty_lockless(&udp_sk(sk)->reader_queue))
4149 		return true;
4150 
4151 	return sk_busy_loop_timeout(sk, start_time);
4152 }
4153 EXPORT_SYMBOL(sk_busy_loop_end);
4154 #endif /* CONFIG_NET_RX_BUSY_POLL */
4155 
4156 int sock_bind_add(struct sock *sk, struct sockaddr *addr, int addr_len)
4157 {
4158 	if (!sk->sk_prot->bind_add)
4159 		return -EOPNOTSUPP;
4160 	return sk->sk_prot->bind_add(sk, addr, addr_len);
4161 }
4162 EXPORT_SYMBOL(sock_bind_add);
4163 
4164 /* Copy 'size' bytes from userspace and return `size` back to userspace */
4165 int sock_ioctl_inout(struct sock *sk, unsigned int cmd,
4166 		     void __user *arg, void *karg, size_t size)
4167 {
4168 	int ret;
4169 
4170 	if (copy_from_user(karg, arg, size))
4171 		return -EFAULT;
4172 
4173 	ret = READ_ONCE(sk->sk_prot)->ioctl(sk, cmd, karg);
4174 	if (ret)
4175 		return ret;
4176 
4177 	if (copy_to_user(arg, karg, size))
4178 		return -EFAULT;
4179 
4180 	return 0;
4181 }
4182 EXPORT_SYMBOL(sock_ioctl_inout);
4183 
4184 /* This is the most common ioctl prep function, where the result (4 bytes) is
4185  * copied back to userspace if the ioctl() returns successfully. No input is
4186  * copied from userspace as input argument.
4187  */
4188 static int sock_ioctl_out(struct sock *sk, unsigned int cmd, void __user *arg)
4189 {
4190 	int ret, karg = 0;
4191 
4192 	ret = READ_ONCE(sk->sk_prot)->ioctl(sk, cmd, &karg);
4193 	if (ret)
4194 		return ret;
4195 
4196 	return put_user(karg, (int __user *)arg);
4197 }
4198 
4199 /* A wrapper around sock ioctls, which copies the data from userspace
4200  * (depending on the protocol/ioctl), and copies back the result to userspace.
4201  * The main motivation for this function is to pass kernel memory to the
4202  * protocol ioctl callbacks, instead of userspace memory.
4203  */
4204 int sk_ioctl(struct sock *sk, unsigned int cmd, void __user *arg)
4205 {
4206 	int rc = 1;
4207 
4208 	if (sk->sk_type == SOCK_RAW && sk->sk_family == AF_INET)
4209 		rc = ipmr_sk_ioctl(sk, cmd, arg);
4210 	else if (sk->sk_type == SOCK_RAW && sk->sk_family == AF_INET6)
4211 		rc = ip6mr_sk_ioctl(sk, cmd, arg);
4212 	else if (sk_is_phonet(sk))
4213 		rc = phonet_sk_ioctl(sk, cmd, arg);
4214 
4215 	/* If ioctl was processed, returns its value */
4216 	if (rc <= 0)
4217 		return rc;
4218 
4219 	/* Otherwise call the default handler */
4220 	return sock_ioctl_out(sk, cmd, arg);
4221 }
4222 EXPORT_SYMBOL(sk_ioctl);
4223