xref: /linux/net/core/sock.c (revision a594533df0f6ca391da003f43d53b336a2d23ffa)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * INET		An implementation of the TCP/IP protocol suite for the LINUX
4  *		operating system.  INET is implemented using the  BSD Socket
5  *		interface as the means of communication with the user level.
6  *
7  *		Generic socket support routines. Memory allocators, socket lock/release
8  *		handler for protocols to use and generic option handler.
9  *
10  * Authors:	Ross Biro
11  *		Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
12  *		Florian La Roche, <flla@stud.uni-sb.de>
13  *		Alan Cox, <A.Cox@swansea.ac.uk>
14  *
15  * Fixes:
16  *		Alan Cox	: 	Numerous verify_area() problems
17  *		Alan Cox	:	Connecting on a connecting socket
18  *					now returns an error for tcp.
19  *		Alan Cox	:	sock->protocol is set correctly.
20  *					and is not sometimes left as 0.
21  *		Alan Cox	:	connect handles icmp errors on a
22  *					connect properly. Unfortunately there
23  *					is a restart syscall nasty there. I
24  *					can't match BSD without hacking the C
25  *					library. Ideas urgently sought!
26  *		Alan Cox	:	Disallow bind() to addresses that are
27  *					not ours - especially broadcast ones!!
28  *		Alan Cox	:	Socket 1024 _IS_ ok for users. (fencepost)
29  *		Alan Cox	:	sock_wfree/sock_rfree don't destroy sockets,
30  *					instead they leave that for the DESTROY timer.
31  *		Alan Cox	:	Clean up error flag in accept
32  *		Alan Cox	:	TCP ack handling is buggy, the DESTROY timer
33  *					was buggy. Put a remove_sock() in the handler
34  *					for memory when we hit 0. Also altered the timer
35  *					code. The ACK stuff can wait and needs major
36  *					TCP layer surgery.
37  *		Alan Cox	:	Fixed TCP ack bug, removed remove sock
38  *					and fixed timer/inet_bh race.
39  *		Alan Cox	:	Added zapped flag for TCP
40  *		Alan Cox	:	Move kfree_skb into skbuff.c and tidied up surplus code
41  *		Alan Cox	:	for new sk_buff allocations wmalloc/rmalloc now call alloc_skb
42  *		Alan Cox	:	kfree_s calls now are kfree_skbmem so we can track skb resources
43  *		Alan Cox	:	Supports socket option broadcast now as does udp. Packet and raw need fixing.
44  *		Alan Cox	:	Added RCVBUF,SNDBUF size setting. It suddenly occurred to me how easy it was so...
45  *		Rick Sladkey	:	Relaxed UDP rules for matching packets.
46  *		C.E.Hawkins	:	IFF_PROMISC/SIOCGHWADDR support
47  *	Pauline Middelink	:	identd support
48  *		Alan Cox	:	Fixed connect() taking signals I think.
49  *		Alan Cox	:	SO_LINGER supported
50  *		Alan Cox	:	Error reporting fixes
51  *		Anonymous	:	inet_create tidied up (sk->reuse setting)
52  *		Alan Cox	:	inet sockets don't set sk->type!
53  *		Alan Cox	:	Split socket option code
54  *		Alan Cox	:	Callbacks
55  *		Alan Cox	:	Nagle flag for Charles & Johannes stuff
56  *		Alex		:	Removed restriction on inet fioctl
57  *		Alan Cox	:	Splitting INET from NET core
58  *		Alan Cox	:	Fixed bogus SO_TYPE handling in getsockopt()
59  *		Adam Caldwell	:	Missing return in SO_DONTROUTE/SO_DEBUG code
60  *		Alan Cox	:	Split IP from generic code
61  *		Alan Cox	:	New kfree_skbmem()
62  *		Alan Cox	:	Make SO_DEBUG superuser only.
63  *		Alan Cox	:	Allow anyone to clear SO_DEBUG
64  *					(compatibility fix)
65  *		Alan Cox	:	Added optimistic memory grabbing for AF_UNIX throughput.
66  *		Alan Cox	:	Allocator for a socket is settable.
67  *		Alan Cox	:	SO_ERROR includes soft errors.
68  *		Alan Cox	:	Allow NULL arguments on some SO_ opts
69  *		Alan Cox	: 	Generic socket allocation to make hooks
70  *					easier (suggested by Craig Metz).
71  *		Michael Pall	:	SO_ERROR returns positive errno again
72  *              Steve Whitehouse:       Added default destructor to free
73  *                                      protocol private data.
74  *              Steve Whitehouse:       Added various other default routines
75  *                                      common to several socket families.
76  *              Chris Evans     :       Call suser() check last on F_SETOWN
77  *		Jay Schulist	:	Added SO_ATTACH_FILTER and SO_DETACH_FILTER.
78  *		Andi Kleen	:	Add sock_kmalloc()/sock_kfree_s()
79  *		Andi Kleen	:	Fix write_space callback
80  *		Chris Evans	:	Security fixes - signedness again
81  *		Arnaldo C. Melo :       cleanups, use skb_queue_purge
82  *
83  * To Fix:
84  */
85 
86 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
87 
88 #include <asm/unaligned.h>
89 #include <linux/capability.h>
90 #include <linux/errno.h>
91 #include <linux/errqueue.h>
92 #include <linux/types.h>
93 #include <linux/socket.h>
94 #include <linux/in.h>
95 #include <linux/kernel.h>
96 #include <linux/module.h>
97 #include <linux/proc_fs.h>
98 #include <linux/seq_file.h>
99 #include <linux/sched.h>
100 #include <linux/sched/mm.h>
101 #include <linux/timer.h>
102 #include <linux/string.h>
103 #include <linux/sockios.h>
104 #include <linux/net.h>
105 #include <linux/mm.h>
106 #include <linux/slab.h>
107 #include <linux/interrupt.h>
108 #include <linux/poll.h>
109 #include <linux/tcp.h>
110 #include <linux/init.h>
111 #include <linux/highmem.h>
112 #include <linux/user_namespace.h>
113 #include <linux/static_key.h>
114 #include <linux/memcontrol.h>
115 #include <linux/prefetch.h>
116 #include <linux/compat.h>
117 
118 #include <linux/uaccess.h>
119 
120 #include <linux/netdevice.h>
121 #include <net/protocol.h>
122 #include <linux/skbuff.h>
123 #include <net/net_namespace.h>
124 #include <net/request_sock.h>
125 #include <net/sock.h>
126 #include <linux/net_tstamp.h>
127 #include <net/xfrm.h>
128 #include <linux/ipsec.h>
129 #include <net/cls_cgroup.h>
130 #include <net/netprio_cgroup.h>
131 #include <linux/sock_diag.h>
132 
133 #include <linux/filter.h>
134 #include <net/sock_reuseport.h>
135 #include <net/bpf_sk_storage.h>
136 
137 #include <trace/events/sock.h>
138 
139 #include <net/tcp.h>
140 #include <net/busy_poll.h>
141 
142 #include <linux/ethtool.h>
143 
144 #include "dev.h"
145 
146 static DEFINE_MUTEX(proto_list_mutex);
147 static LIST_HEAD(proto_list);
148 
149 static void sock_def_write_space_wfree(struct sock *sk);
150 static void sock_def_write_space(struct sock *sk);
151 
152 /**
153  * sk_ns_capable - General socket capability test
154  * @sk: Socket to use a capability on or through
155  * @user_ns: The user namespace of the capability to use
156  * @cap: The capability to use
157  *
158  * Test to see if the opener of the socket had when the socket was
159  * created and the current process has the capability @cap in the user
160  * namespace @user_ns.
161  */
162 bool sk_ns_capable(const struct sock *sk,
163 		   struct user_namespace *user_ns, int cap)
164 {
165 	return file_ns_capable(sk->sk_socket->file, user_ns, cap) &&
166 		ns_capable(user_ns, cap);
167 }
168 EXPORT_SYMBOL(sk_ns_capable);
169 
170 /**
171  * sk_capable - Socket global capability test
172  * @sk: Socket to use a capability on or through
173  * @cap: The global capability to use
174  *
175  * Test to see if the opener of the socket had when the socket was
176  * created and the current process has the capability @cap in all user
177  * namespaces.
178  */
179 bool sk_capable(const struct sock *sk, int cap)
180 {
181 	return sk_ns_capable(sk, &init_user_ns, cap);
182 }
183 EXPORT_SYMBOL(sk_capable);
184 
185 /**
186  * sk_net_capable - Network namespace socket capability test
187  * @sk: Socket to use a capability on or through
188  * @cap: The capability to use
189  *
190  * Test to see if the opener of the socket had when the socket was created
191  * and the current process has the capability @cap over the network namespace
192  * the socket is a member of.
193  */
194 bool sk_net_capable(const struct sock *sk, int cap)
195 {
196 	return sk_ns_capable(sk, sock_net(sk)->user_ns, cap);
197 }
198 EXPORT_SYMBOL(sk_net_capable);
199 
200 /*
201  * Each address family might have different locking rules, so we have
202  * one slock key per address family and separate keys for internal and
203  * userspace sockets.
204  */
205 static struct lock_class_key af_family_keys[AF_MAX];
206 static struct lock_class_key af_family_kern_keys[AF_MAX];
207 static struct lock_class_key af_family_slock_keys[AF_MAX];
208 static struct lock_class_key af_family_kern_slock_keys[AF_MAX];
209 
210 /*
211  * Make lock validator output more readable. (we pre-construct these
212  * strings build-time, so that runtime initialization of socket
213  * locks is fast):
214  */
215 
216 #define _sock_locks(x)						  \
217   x "AF_UNSPEC",	x "AF_UNIX"     ,	x "AF_INET"     , \
218   x "AF_AX25"  ,	x "AF_IPX"      ,	x "AF_APPLETALK", \
219   x "AF_NETROM",	x "AF_BRIDGE"   ,	x "AF_ATMPVC"   , \
220   x "AF_X25"   ,	x "AF_INET6"    ,	x "AF_ROSE"     , \
221   x "AF_DECnet",	x "AF_NETBEUI"  ,	x "AF_SECURITY" , \
222   x "AF_KEY"   ,	x "AF_NETLINK"  ,	x "AF_PACKET"   , \
223   x "AF_ASH"   ,	x "AF_ECONET"   ,	x "AF_ATMSVC"   , \
224   x "AF_RDS"   ,	x "AF_SNA"      ,	x "AF_IRDA"     , \
225   x "AF_PPPOX" ,	x "AF_WANPIPE"  ,	x "AF_LLC"      , \
226   x "27"       ,	x "28"          ,	x "AF_CAN"      , \
227   x "AF_TIPC"  ,	x "AF_BLUETOOTH",	x "IUCV"        , \
228   x "AF_RXRPC" ,	x "AF_ISDN"     ,	x "AF_PHONET"   , \
229   x "AF_IEEE802154",	x "AF_CAIF"	,	x "AF_ALG"      , \
230   x "AF_NFC"   ,	x "AF_VSOCK"    ,	x "AF_KCM"      , \
231   x "AF_QIPCRTR",	x "AF_SMC"	,	x "AF_XDP"	, \
232   x "AF_MCTP"  , \
233   x "AF_MAX"
234 
235 static const char *const af_family_key_strings[AF_MAX+1] = {
236 	_sock_locks("sk_lock-")
237 };
238 static const char *const af_family_slock_key_strings[AF_MAX+1] = {
239 	_sock_locks("slock-")
240 };
241 static const char *const af_family_clock_key_strings[AF_MAX+1] = {
242 	_sock_locks("clock-")
243 };
244 
245 static const char *const af_family_kern_key_strings[AF_MAX+1] = {
246 	_sock_locks("k-sk_lock-")
247 };
248 static const char *const af_family_kern_slock_key_strings[AF_MAX+1] = {
249 	_sock_locks("k-slock-")
250 };
251 static const char *const af_family_kern_clock_key_strings[AF_MAX+1] = {
252 	_sock_locks("k-clock-")
253 };
254 static const char *const af_family_rlock_key_strings[AF_MAX+1] = {
255 	_sock_locks("rlock-")
256 };
257 static const char *const af_family_wlock_key_strings[AF_MAX+1] = {
258 	_sock_locks("wlock-")
259 };
260 static const char *const af_family_elock_key_strings[AF_MAX+1] = {
261 	_sock_locks("elock-")
262 };
263 
264 /*
265  * sk_callback_lock and sk queues locking rules are per-address-family,
266  * so split the lock classes by using a per-AF key:
267  */
268 static struct lock_class_key af_callback_keys[AF_MAX];
269 static struct lock_class_key af_rlock_keys[AF_MAX];
270 static struct lock_class_key af_wlock_keys[AF_MAX];
271 static struct lock_class_key af_elock_keys[AF_MAX];
272 static struct lock_class_key af_kern_callback_keys[AF_MAX];
273 
274 /* Run time adjustable parameters. */
275 __u32 sysctl_wmem_max __read_mostly = SK_WMEM_MAX;
276 EXPORT_SYMBOL(sysctl_wmem_max);
277 __u32 sysctl_rmem_max __read_mostly = SK_RMEM_MAX;
278 EXPORT_SYMBOL(sysctl_rmem_max);
279 __u32 sysctl_wmem_default __read_mostly = SK_WMEM_MAX;
280 __u32 sysctl_rmem_default __read_mostly = SK_RMEM_MAX;
281 
282 /* Maximal space eaten by iovec or ancillary data plus some space */
283 int sysctl_optmem_max __read_mostly = sizeof(unsigned long)*(2*UIO_MAXIOV+512);
284 EXPORT_SYMBOL(sysctl_optmem_max);
285 
286 int sysctl_tstamp_allow_data __read_mostly = 1;
287 
288 DEFINE_STATIC_KEY_FALSE(memalloc_socks_key);
289 EXPORT_SYMBOL_GPL(memalloc_socks_key);
290 
291 /**
292  * sk_set_memalloc - sets %SOCK_MEMALLOC
293  * @sk: socket to set it on
294  *
295  * Set %SOCK_MEMALLOC on a socket for access to emergency reserves.
296  * It's the responsibility of the admin to adjust min_free_kbytes
297  * to meet the requirements
298  */
299 void sk_set_memalloc(struct sock *sk)
300 {
301 	sock_set_flag(sk, SOCK_MEMALLOC);
302 	sk->sk_allocation |= __GFP_MEMALLOC;
303 	static_branch_inc(&memalloc_socks_key);
304 }
305 EXPORT_SYMBOL_GPL(sk_set_memalloc);
306 
307 void sk_clear_memalloc(struct sock *sk)
308 {
309 	sock_reset_flag(sk, SOCK_MEMALLOC);
310 	sk->sk_allocation &= ~__GFP_MEMALLOC;
311 	static_branch_dec(&memalloc_socks_key);
312 
313 	/*
314 	 * SOCK_MEMALLOC is allowed to ignore rmem limits to ensure forward
315 	 * progress of swapping. SOCK_MEMALLOC may be cleared while
316 	 * it has rmem allocations due to the last swapfile being deactivated
317 	 * but there is a risk that the socket is unusable due to exceeding
318 	 * the rmem limits. Reclaim the reserves and obey rmem limits again.
319 	 */
320 	sk_mem_reclaim(sk);
321 }
322 EXPORT_SYMBOL_GPL(sk_clear_memalloc);
323 
324 int __sk_backlog_rcv(struct sock *sk, struct sk_buff *skb)
325 {
326 	int ret;
327 	unsigned int noreclaim_flag;
328 
329 	/* these should have been dropped before queueing */
330 	BUG_ON(!sock_flag(sk, SOCK_MEMALLOC));
331 
332 	noreclaim_flag = memalloc_noreclaim_save();
333 	ret = INDIRECT_CALL_INET(sk->sk_backlog_rcv,
334 				 tcp_v6_do_rcv,
335 				 tcp_v4_do_rcv,
336 				 sk, skb);
337 	memalloc_noreclaim_restore(noreclaim_flag);
338 
339 	return ret;
340 }
341 EXPORT_SYMBOL(__sk_backlog_rcv);
342 
343 void sk_error_report(struct sock *sk)
344 {
345 	sk->sk_error_report(sk);
346 
347 	switch (sk->sk_family) {
348 	case AF_INET:
349 		fallthrough;
350 	case AF_INET6:
351 		trace_inet_sk_error_report(sk);
352 		break;
353 	default:
354 		break;
355 	}
356 }
357 EXPORT_SYMBOL(sk_error_report);
358 
359 int sock_get_timeout(long timeo, void *optval, bool old_timeval)
360 {
361 	struct __kernel_sock_timeval tv;
362 
363 	if (timeo == MAX_SCHEDULE_TIMEOUT) {
364 		tv.tv_sec = 0;
365 		tv.tv_usec = 0;
366 	} else {
367 		tv.tv_sec = timeo / HZ;
368 		tv.tv_usec = ((timeo % HZ) * USEC_PER_SEC) / HZ;
369 	}
370 
371 	if (old_timeval && in_compat_syscall() && !COMPAT_USE_64BIT_TIME) {
372 		struct old_timeval32 tv32 = { tv.tv_sec, tv.tv_usec };
373 		*(struct old_timeval32 *)optval = tv32;
374 		return sizeof(tv32);
375 	}
376 
377 	if (old_timeval) {
378 		struct __kernel_old_timeval old_tv;
379 		old_tv.tv_sec = tv.tv_sec;
380 		old_tv.tv_usec = tv.tv_usec;
381 		*(struct __kernel_old_timeval *)optval = old_tv;
382 		return sizeof(old_tv);
383 	}
384 
385 	*(struct __kernel_sock_timeval *)optval = tv;
386 	return sizeof(tv);
387 }
388 EXPORT_SYMBOL(sock_get_timeout);
389 
390 int sock_copy_user_timeval(struct __kernel_sock_timeval *tv,
391 			   sockptr_t optval, int optlen, bool old_timeval)
392 {
393 	if (old_timeval && in_compat_syscall() && !COMPAT_USE_64BIT_TIME) {
394 		struct old_timeval32 tv32;
395 
396 		if (optlen < sizeof(tv32))
397 			return -EINVAL;
398 
399 		if (copy_from_sockptr(&tv32, optval, sizeof(tv32)))
400 			return -EFAULT;
401 		tv->tv_sec = tv32.tv_sec;
402 		tv->tv_usec = tv32.tv_usec;
403 	} else if (old_timeval) {
404 		struct __kernel_old_timeval old_tv;
405 
406 		if (optlen < sizeof(old_tv))
407 			return -EINVAL;
408 		if (copy_from_sockptr(&old_tv, optval, sizeof(old_tv)))
409 			return -EFAULT;
410 		tv->tv_sec = old_tv.tv_sec;
411 		tv->tv_usec = old_tv.tv_usec;
412 	} else {
413 		if (optlen < sizeof(*tv))
414 			return -EINVAL;
415 		if (copy_from_sockptr(tv, optval, sizeof(*tv)))
416 			return -EFAULT;
417 	}
418 
419 	return 0;
420 }
421 EXPORT_SYMBOL(sock_copy_user_timeval);
422 
423 static int sock_set_timeout(long *timeo_p, sockptr_t optval, int optlen,
424 			    bool old_timeval)
425 {
426 	struct __kernel_sock_timeval tv;
427 	int err = sock_copy_user_timeval(&tv, optval, optlen, old_timeval);
428 
429 	if (err)
430 		return err;
431 
432 	if (tv.tv_usec < 0 || tv.tv_usec >= USEC_PER_SEC)
433 		return -EDOM;
434 
435 	if (tv.tv_sec < 0) {
436 		static int warned __read_mostly;
437 
438 		*timeo_p = 0;
439 		if (warned < 10 && net_ratelimit()) {
440 			warned++;
441 			pr_info("%s: `%s' (pid %d) tries to set negative timeout\n",
442 				__func__, current->comm, task_pid_nr(current));
443 		}
444 		return 0;
445 	}
446 	*timeo_p = MAX_SCHEDULE_TIMEOUT;
447 	if (tv.tv_sec == 0 && tv.tv_usec == 0)
448 		return 0;
449 	if (tv.tv_sec < (MAX_SCHEDULE_TIMEOUT / HZ - 1))
450 		*timeo_p = tv.tv_sec * HZ + DIV_ROUND_UP((unsigned long)tv.tv_usec, USEC_PER_SEC / HZ);
451 	return 0;
452 }
453 
454 static bool sock_needs_netstamp(const struct sock *sk)
455 {
456 	switch (sk->sk_family) {
457 	case AF_UNSPEC:
458 	case AF_UNIX:
459 		return false;
460 	default:
461 		return true;
462 	}
463 }
464 
465 static void sock_disable_timestamp(struct sock *sk, unsigned long flags)
466 {
467 	if (sk->sk_flags & flags) {
468 		sk->sk_flags &= ~flags;
469 		if (sock_needs_netstamp(sk) &&
470 		    !(sk->sk_flags & SK_FLAGS_TIMESTAMP))
471 			net_disable_timestamp();
472 	}
473 }
474 
475 
476 int __sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
477 {
478 	unsigned long flags;
479 	struct sk_buff_head *list = &sk->sk_receive_queue;
480 
481 	if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf) {
482 		atomic_inc(&sk->sk_drops);
483 		trace_sock_rcvqueue_full(sk, skb);
484 		return -ENOMEM;
485 	}
486 
487 	if (!sk_rmem_schedule(sk, skb, skb->truesize)) {
488 		atomic_inc(&sk->sk_drops);
489 		return -ENOBUFS;
490 	}
491 
492 	skb->dev = NULL;
493 	skb_set_owner_r(skb, sk);
494 
495 	/* we escape from rcu protected region, make sure we dont leak
496 	 * a norefcounted dst
497 	 */
498 	skb_dst_force(skb);
499 
500 	spin_lock_irqsave(&list->lock, flags);
501 	sock_skb_set_dropcount(sk, skb);
502 	__skb_queue_tail(list, skb);
503 	spin_unlock_irqrestore(&list->lock, flags);
504 
505 	if (!sock_flag(sk, SOCK_DEAD))
506 		sk->sk_data_ready(sk);
507 	return 0;
508 }
509 EXPORT_SYMBOL(__sock_queue_rcv_skb);
510 
511 int sock_queue_rcv_skb_reason(struct sock *sk, struct sk_buff *skb,
512 			      enum skb_drop_reason *reason)
513 {
514 	enum skb_drop_reason drop_reason;
515 	int err;
516 
517 	err = sk_filter(sk, skb);
518 	if (err) {
519 		drop_reason = SKB_DROP_REASON_SOCKET_FILTER;
520 		goto out;
521 	}
522 	err = __sock_queue_rcv_skb(sk, skb);
523 	switch (err) {
524 	case -ENOMEM:
525 		drop_reason = SKB_DROP_REASON_SOCKET_RCVBUFF;
526 		break;
527 	case -ENOBUFS:
528 		drop_reason = SKB_DROP_REASON_PROTO_MEM;
529 		break;
530 	default:
531 		drop_reason = SKB_NOT_DROPPED_YET;
532 		break;
533 	}
534 out:
535 	if (reason)
536 		*reason = drop_reason;
537 	return err;
538 }
539 EXPORT_SYMBOL(sock_queue_rcv_skb_reason);
540 
541 int __sk_receive_skb(struct sock *sk, struct sk_buff *skb,
542 		     const int nested, unsigned int trim_cap, bool refcounted)
543 {
544 	int rc = NET_RX_SUCCESS;
545 
546 	if (sk_filter_trim_cap(sk, skb, trim_cap))
547 		goto discard_and_relse;
548 
549 	skb->dev = NULL;
550 
551 	if (sk_rcvqueues_full(sk, sk->sk_rcvbuf)) {
552 		atomic_inc(&sk->sk_drops);
553 		goto discard_and_relse;
554 	}
555 	if (nested)
556 		bh_lock_sock_nested(sk);
557 	else
558 		bh_lock_sock(sk);
559 	if (!sock_owned_by_user(sk)) {
560 		/*
561 		 * trylock + unlock semantics:
562 		 */
563 		mutex_acquire(&sk->sk_lock.dep_map, 0, 1, _RET_IP_);
564 
565 		rc = sk_backlog_rcv(sk, skb);
566 
567 		mutex_release(&sk->sk_lock.dep_map, _RET_IP_);
568 	} else if (sk_add_backlog(sk, skb, READ_ONCE(sk->sk_rcvbuf))) {
569 		bh_unlock_sock(sk);
570 		atomic_inc(&sk->sk_drops);
571 		goto discard_and_relse;
572 	}
573 
574 	bh_unlock_sock(sk);
575 out:
576 	if (refcounted)
577 		sock_put(sk);
578 	return rc;
579 discard_and_relse:
580 	kfree_skb(skb);
581 	goto out;
582 }
583 EXPORT_SYMBOL(__sk_receive_skb);
584 
585 INDIRECT_CALLABLE_DECLARE(struct dst_entry *ip6_dst_check(struct dst_entry *,
586 							  u32));
587 INDIRECT_CALLABLE_DECLARE(struct dst_entry *ipv4_dst_check(struct dst_entry *,
588 							   u32));
589 struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie)
590 {
591 	struct dst_entry *dst = __sk_dst_get(sk);
592 
593 	if (dst && dst->obsolete &&
594 	    INDIRECT_CALL_INET(dst->ops->check, ip6_dst_check, ipv4_dst_check,
595 			       dst, cookie) == NULL) {
596 		sk_tx_queue_clear(sk);
597 		sk->sk_dst_pending_confirm = 0;
598 		RCU_INIT_POINTER(sk->sk_dst_cache, NULL);
599 		dst_release(dst);
600 		return NULL;
601 	}
602 
603 	return dst;
604 }
605 EXPORT_SYMBOL(__sk_dst_check);
606 
607 struct dst_entry *sk_dst_check(struct sock *sk, u32 cookie)
608 {
609 	struct dst_entry *dst = sk_dst_get(sk);
610 
611 	if (dst && dst->obsolete &&
612 	    INDIRECT_CALL_INET(dst->ops->check, ip6_dst_check, ipv4_dst_check,
613 			       dst, cookie) == NULL) {
614 		sk_dst_reset(sk);
615 		dst_release(dst);
616 		return NULL;
617 	}
618 
619 	return dst;
620 }
621 EXPORT_SYMBOL(sk_dst_check);
622 
623 static int sock_bindtoindex_locked(struct sock *sk, int ifindex)
624 {
625 	int ret = -ENOPROTOOPT;
626 #ifdef CONFIG_NETDEVICES
627 	struct net *net = sock_net(sk);
628 
629 	/* Sorry... */
630 	ret = -EPERM;
631 	if (sk->sk_bound_dev_if && !ns_capable(net->user_ns, CAP_NET_RAW))
632 		goto out;
633 
634 	ret = -EINVAL;
635 	if (ifindex < 0)
636 		goto out;
637 
638 	/* Paired with all READ_ONCE() done locklessly. */
639 	WRITE_ONCE(sk->sk_bound_dev_if, ifindex);
640 
641 	if (sk->sk_prot->rehash)
642 		sk->sk_prot->rehash(sk);
643 	sk_dst_reset(sk);
644 
645 	ret = 0;
646 
647 out:
648 #endif
649 
650 	return ret;
651 }
652 
653 int sock_bindtoindex(struct sock *sk, int ifindex, bool lock_sk)
654 {
655 	int ret;
656 
657 	if (lock_sk)
658 		lock_sock(sk);
659 	ret = sock_bindtoindex_locked(sk, ifindex);
660 	if (lock_sk)
661 		release_sock(sk);
662 
663 	return ret;
664 }
665 EXPORT_SYMBOL(sock_bindtoindex);
666 
667 static int sock_setbindtodevice(struct sock *sk, sockptr_t optval, int optlen)
668 {
669 	int ret = -ENOPROTOOPT;
670 #ifdef CONFIG_NETDEVICES
671 	struct net *net = sock_net(sk);
672 	char devname[IFNAMSIZ];
673 	int index;
674 
675 	ret = -EINVAL;
676 	if (optlen < 0)
677 		goto out;
678 
679 	/* Bind this socket to a particular device like "eth0",
680 	 * as specified in the passed interface name. If the
681 	 * name is "" or the option length is zero the socket
682 	 * is not bound.
683 	 */
684 	if (optlen > IFNAMSIZ - 1)
685 		optlen = IFNAMSIZ - 1;
686 	memset(devname, 0, sizeof(devname));
687 
688 	ret = -EFAULT;
689 	if (copy_from_sockptr(devname, optval, optlen))
690 		goto out;
691 
692 	index = 0;
693 	if (devname[0] != '\0') {
694 		struct net_device *dev;
695 
696 		rcu_read_lock();
697 		dev = dev_get_by_name_rcu(net, devname);
698 		if (dev)
699 			index = dev->ifindex;
700 		rcu_read_unlock();
701 		ret = -ENODEV;
702 		if (!dev)
703 			goto out;
704 	}
705 
706 	sockopt_lock_sock(sk);
707 	ret = sock_bindtoindex_locked(sk, index);
708 	sockopt_release_sock(sk);
709 out:
710 #endif
711 
712 	return ret;
713 }
714 
715 static int sock_getbindtodevice(struct sock *sk, sockptr_t optval,
716 				sockptr_t optlen, int len)
717 {
718 	int ret = -ENOPROTOOPT;
719 #ifdef CONFIG_NETDEVICES
720 	int bound_dev_if = READ_ONCE(sk->sk_bound_dev_if);
721 	struct net *net = sock_net(sk);
722 	char devname[IFNAMSIZ];
723 
724 	if (bound_dev_if == 0) {
725 		len = 0;
726 		goto zero;
727 	}
728 
729 	ret = -EINVAL;
730 	if (len < IFNAMSIZ)
731 		goto out;
732 
733 	ret = netdev_get_name(net, devname, bound_dev_if);
734 	if (ret)
735 		goto out;
736 
737 	len = strlen(devname) + 1;
738 
739 	ret = -EFAULT;
740 	if (copy_to_sockptr(optval, devname, len))
741 		goto out;
742 
743 zero:
744 	ret = -EFAULT;
745 	if (copy_to_sockptr(optlen, &len, sizeof(int)))
746 		goto out;
747 
748 	ret = 0;
749 
750 out:
751 #endif
752 
753 	return ret;
754 }
755 
756 bool sk_mc_loop(struct sock *sk)
757 {
758 	if (dev_recursion_level())
759 		return false;
760 	if (!sk)
761 		return true;
762 	switch (sk->sk_family) {
763 	case AF_INET:
764 		return inet_sk(sk)->mc_loop;
765 #if IS_ENABLED(CONFIG_IPV6)
766 	case AF_INET6:
767 		return inet6_sk(sk)->mc_loop;
768 #endif
769 	}
770 	WARN_ON_ONCE(1);
771 	return true;
772 }
773 EXPORT_SYMBOL(sk_mc_loop);
774 
775 void sock_set_reuseaddr(struct sock *sk)
776 {
777 	lock_sock(sk);
778 	sk->sk_reuse = SK_CAN_REUSE;
779 	release_sock(sk);
780 }
781 EXPORT_SYMBOL(sock_set_reuseaddr);
782 
783 void sock_set_reuseport(struct sock *sk)
784 {
785 	lock_sock(sk);
786 	sk->sk_reuseport = true;
787 	release_sock(sk);
788 }
789 EXPORT_SYMBOL(sock_set_reuseport);
790 
791 void sock_no_linger(struct sock *sk)
792 {
793 	lock_sock(sk);
794 	sk->sk_lingertime = 0;
795 	sock_set_flag(sk, SOCK_LINGER);
796 	release_sock(sk);
797 }
798 EXPORT_SYMBOL(sock_no_linger);
799 
800 void sock_set_priority(struct sock *sk, u32 priority)
801 {
802 	lock_sock(sk);
803 	sk->sk_priority = priority;
804 	release_sock(sk);
805 }
806 EXPORT_SYMBOL(sock_set_priority);
807 
808 void sock_set_sndtimeo(struct sock *sk, s64 secs)
809 {
810 	lock_sock(sk);
811 	if (secs && secs < MAX_SCHEDULE_TIMEOUT / HZ - 1)
812 		sk->sk_sndtimeo = secs * HZ;
813 	else
814 		sk->sk_sndtimeo = MAX_SCHEDULE_TIMEOUT;
815 	release_sock(sk);
816 }
817 EXPORT_SYMBOL(sock_set_sndtimeo);
818 
819 static void __sock_set_timestamps(struct sock *sk, bool val, bool new, bool ns)
820 {
821 	if (val)  {
822 		sock_valbool_flag(sk, SOCK_TSTAMP_NEW, new);
823 		sock_valbool_flag(sk, SOCK_RCVTSTAMPNS, ns);
824 		sock_set_flag(sk, SOCK_RCVTSTAMP);
825 		sock_enable_timestamp(sk, SOCK_TIMESTAMP);
826 	} else {
827 		sock_reset_flag(sk, SOCK_RCVTSTAMP);
828 		sock_reset_flag(sk, SOCK_RCVTSTAMPNS);
829 	}
830 }
831 
832 void sock_enable_timestamps(struct sock *sk)
833 {
834 	lock_sock(sk);
835 	__sock_set_timestamps(sk, true, false, true);
836 	release_sock(sk);
837 }
838 EXPORT_SYMBOL(sock_enable_timestamps);
839 
840 void sock_set_timestamp(struct sock *sk, int optname, bool valbool)
841 {
842 	switch (optname) {
843 	case SO_TIMESTAMP_OLD:
844 		__sock_set_timestamps(sk, valbool, false, false);
845 		break;
846 	case SO_TIMESTAMP_NEW:
847 		__sock_set_timestamps(sk, valbool, true, false);
848 		break;
849 	case SO_TIMESTAMPNS_OLD:
850 		__sock_set_timestamps(sk, valbool, false, true);
851 		break;
852 	case SO_TIMESTAMPNS_NEW:
853 		__sock_set_timestamps(sk, valbool, true, true);
854 		break;
855 	}
856 }
857 
858 static int sock_timestamping_bind_phc(struct sock *sk, int phc_index)
859 {
860 	struct net *net = sock_net(sk);
861 	struct net_device *dev = NULL;
862 	bool match = false;
863 	int *vclock_index;
864 	int i, num;
865 
866 	if (sk->sk_bound_dev_if)
867 		dev = dev_get_by_index(net, sk->sk_bound_dev_if);
868 
869 	if (!dev) {
870 		pr_err("%s: sock not bind to device\n", __func__);
871 		return -EOPNOTSUPP;
872 	}
873 
874 	num = ethtool_get_phc_vclocks(dev, &vclock_index);
875 	dev_put(dev);
876 
877 	for (i = 0; i < num; i++) {
878 		if (*(vclock_index + i) == phc_index) {
879 			match = true;
880 			break;
881 		}
882 	}
883 
884 	if (num > 0)
885 		kfree(vclock_index);
886 
887 	if (!match)
888 		return -EINVAL;
889 
890 	sk->sk_bind_phc = phc_index;
891 
892 	return 0;
893 }
894 
895 int sock_set_timestamping(struct sock *sk, int optname,
896 			  struct so_timestamping timestamping)
897 {
898 	int val = timestamping.flags;
899 	int ret;
900 
901 	if (val & ~SOF_TIMESTAMPING_MASK)
902 		return -EINVAL;
903 
904 	if (val & SOF_TIMESTAMPING_OPT_ID &&
905 	    !(sk->sk_tsflags & SOF_TIMESTAMPING_OPT_ID)) {
906 		if (sk_is_tcp(sk)) {
907 			if ((1 << sk->sk_state) &
908 			    (TCPF_CLOSE | TCPF_LISTEN))
909 				return -EINVAL;
910 			atomic_set(&sk->sk_tskey, tcp_sk(sk)->snd_una);
911 		} else {
912 			atomic_set(&sk->sk_tskey, 0);
913 		}
914 	}
915 
916 	if (val & SOF_TIMESTAMPING_OPT_STATS &&
917 	    !(val & SOF_TIMESTAMPING_OPT_TSONLY))
918 		return -EINVAL;
919 
920 	if (val & SOF_TIMESTAMPING_BIND_PHC) {
921 		ret = sock_timestamping_bind_phc(sk, timestamping.bind_phc);
922 		if (ret)
923 			return ret;
924 	}
925 
926 	sk->sk_tsflags = val;
927 	sock_valbool_flag(sk, SOCK_TSTAMP_NEW, optname == SO_TIMESTAMPING_NEW);
928 
929 	if (val & SOF_TIMESTAMPING_RX_SOFTWARE)
930 		sock_enable_timestamp(sk,
931 				      SOCK_TIMESTAMPING_RX_SOFTWARE);
932 	else
933 		sock_disable_timestamp(sk,
934 				       (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE));
935 	return 0;
936 }
937 
938 void sock_set_keepalive(struct sock *sk)
939 {
940 	lock_sock(sk);
941 	if (sk->sk_prot->keepalive)
942 		sk->sk_prot->keepalive(sk, true);
943 	sock_valbool_flag(sk, SOCK_KEEPOPEN, true);
944 	release_sock(sk);
945 }
946 EXPORT_SYMBOL(sock_set_keepalive);
947 
948 static void __sock_set_rcvbuf(struct sock *sk, int val)
949 {
950 	/* Ensure val * 2 fits into an int, to prevent max_t() from treating it
951 	 * as a negative value.
952 	 */
953 	val = min_t(int, val, INT_MAX / 2);
954 	sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
955 
956 	/* We double it on the way in to account for "struct sk_buff" etc.
957 	 * overhead.   Applications assume that the SO_RCVBUF setting they make
958 	 * will allow that much actual data to be received on that socket.
959 	 *
960 	 * Applications are unaware that "struct sk_buff" and other overheads
961 	 * allocate from the receive buffer during socket buffer allocation.
962 	 *
963 	 * And after considering the possible alternatives, returning the value
964 	 * we actually used in getsockopt is the most desirable behavior.
965 	 */
966 	WRITE_ONCE(sk->sk_rcvbuf, max_t(int, val * 2, SOCK_MIN_RCVBUF));
967 }
968 
969 void sock_set_rcvbuf(struct sock *sk, int val)
970 {
971 	lock_sock(sk);
972 	__sock_set_rcvbuf(sk, val);
973 	release_sock(sk);
974 }
975 EXPORT_SYMBOL(sock_set_rcvbuf);
976 
977 static void __sock_set_mark(struct sock *sk, u32 val)
978 {
979 	if (val != sk->sk_mark) {
980 		sk->sk_mark = val;
981 		sk_dst_reset(sk);
982 	}
983 }
984 
985 void sock_set_mark(struct sock *sk, u32 val)
986 {
987 	lock_sock(sk);
988 	__sock_set_mark(sk, val);
989 	release_sock(sk);
990 }
991 EXPORT_SYMBOL(sock_set_mark);
992 
993 static void sock_release_reserved_memory(struct sock *sk, int bytes)
994 {
995 	/* Round down bytes to multiple of pages */
996 	bytes = round_down(bytes, PAGE_SIZE);
997 
998 	WARN_ON(bytes > sk->sk_reserved_mem);
999 	sk->sk_reserved_mem -= bytes;
1000 	sk_mem_reclaim(sk);
1001 }
1002 
1003 static int sock_reserve_memory(struct sock *sk, int bytes)
1004 {
1005 	long allocated;
1006 	bool charged;
1007 	int pages;
1008 
1009 	if (!mem_cgroup_sockets_enabled || !sk->sk_memcg || !sk_has_account(sk))
1010 		return -EOPNOTSUPP;
1011 
1012 	if (!bytes)
1013 		return 0;
1014 
1015 	pages = sk_mem_pages(bytes);
1016 
1017 	/* pre-charge to memcg */
1018 	charged = mem_cgroup_charge_skmem(sk->sk_memcg, pages,
1019 					  GFP_KERNEL | __GFP_RETRY_MAYFAIL);
1020 	if (!charged)
1021 		return -ENOMEM;
1022 
1023 	/* pre-charge to forward_alloc */
1024 	sk_memory_allocated_add(sk, pages);
1025 	allocated = sk_memory_allocated(sk);
1026 	/* If the system goes into memory pressure with this
1027 	 * precharge, give up and return error.
1028 	 */
1029 	if (allocated > sk_prot_mem_limits(sk, 1)) {
1030 		sk_memory_allocated_sub(sk, pages);
1031 		mem_cgroup_uncharge_skmem(sk->sk_memcg, pages);
1032 		return -ENOMEM;
1033 	}
1034 	sk->sk_forward_alloc += pages << PAGE_SHIFT;
1035 
1036 	sk->sk_reserved_mem += pages << PAGE_SHIFT;
1037 
1038 	return 0;
1039 }
1040 
1041 void sockopt_lock_sock(struct sock *sk)
1042 {
1043 	/* When current->bpf_ctx is set, the setsockopt is called from
1044 	 * a bpf prog.  bpf has ensured the sk lock has been
1045 	 * acquired before calling setsockopt().
1046 	 */
1047 	if (has_current_bpf_ctx())
1048 		return;
1049 
1050 	lock_sock(sk);
1051 }
1052 EXPORT_SYMBOL(sockopt_lock_sock);
1053 
1054 void sockopt_release_sock(struct sock *sk)
1055 {
1056 	if (has_current_bpf_ctx())
1057 		return;
1058 
1059 	release_sock(sk);
1060 }
1061 EXPORT_SYMBOL(sockopt_release_sock);
1062 
1063 bool sockopt_ns_capable(struct user_namespace *ns, int cap)
1064 {
1065 	return has_current_bpf_ctx() || ns_capable(ns, cap);
1066 }
1067 EXPORT_SYMBOL(sockopt_ns_capable);
1068 
1069 bool sockopt_capable(int cap)
1070 {
1071 	return has_current_bpf_ctx() || capable(cap);
1072 }
1073 EXPORT_SYMBOL(sockopt_capable);
1074 
1075 /*
1076  *	This is meant for all protocols to use and covers goings on
1077  *	at the socket level. Everything here is generic.
1078  */
1079 
1080 int sk_setsockopt(struct sock *sk, int level, int optname,
1081 		  sockptr_t optval, unsigned int optlen)
1082 {
1083 	struct so_timestamping timestamping;
1084 	struct socket *sock = sk->sk_socket;
1085 	struct sock_txtime sk_txtime;
1086 	int val;
1087 	int valbool;
1088 	struct linger ling;
1089 	int ret = 0;
1090 
1091 	/*
1092 	 *	Options without arguments
1093 	 */
1094 
1095 	if (optname == SO_BINDTODEVICE)
1096 		return sock_setbindtodevice(sk, optval, optlen);
1097 
1098 	if (optlen < sizeof(int))
1099 		return -EINVAL;
1100 
1101 	if (copy_from_sockptr(&val, optval, sizeof(val)))
1102 		return -EFAULT;
1103 
1104 	valbool = val ? 1 : 0;
1105 
1106 	sockopt_lock_sock(sk);
1107 
1108 	switch (optname) {
1109 	case SO_DEBUG:
1110 		if (val && !sockopt_capable(CAP_NET_ADMIN))
1111 			ret = -EACCES;
1112 		else
1113 			sock_valbool_flag(sk, SOCK_DBG, valbool);
1114 		break;
1115 	case SO_REUSEADDR:
1116 		sk->sk_reuse = (valbool ? SK_CAN_REUSE : SK_NO_REUSE);
1117 		break;
1118 	case SO_REUSEPORT:
1119 		sk->sk_reuseport = valbool;
1120 		break;
1121 	case SO_TYPE:
1122 	case SO_PROTOCOL:
1123 	case SO_DOMAIN:
1124 	case SO_ERROR:
1125 		ret = -ENOPROTOOPT;
1126 		break;
1127 	case SO_DONTROUTE:
1128 		sock_valbool_flag(sk, SOCK_LOCALROUTE, valbool);
1129 		sk_dst_reset(sk);
1130 		break;
1131 	case SO_BROADCAST:
1132 		sock_valbool_flag(sk, SOCK_BROADCAST, valbool);
1133 		break;
1134 	case SO_SNDBUF:
1135 		/* Don't error on this BSD doesn't and if you think
1136 		 * about it this is right. Otherwise apps have to
1137 		 * play 'guess the biggest size' games. RCVBUF/SNDBUF
1138 		 * are treated in BSD as hints
1139 		 */
1140 		val = min_t(u32, val, READ_ONCE(sysctl_wmem_max));
1141 set_sndbuf:
1142 		/* Ensure val * 2 fits into an int, to prevent max_t()
1143 		 * from treating it as a negative value.
1144 		 */
1145 		val = min_t(int, val, INT_MAX / 2);
1146 		sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
1147 		WRITE_ONCE(sk->sk_sndbuf,
1148 			   max_t(int, val * 2, SOCK_MIN_SNDBUF));
1149 		/* Wake up sending tasks if we upped the value. */
1150 		sk->sk_write_space(sk);
1151 		break;
1152 
1153 	case SO_SNDBUFFORCE:
1154 		if (!sockopt_capable(CAP_NET_ADMIN)) {
1155 			ret = -EPERM;
1156 			break;
1157 		}
1158 
1159 		/* No negative values (to prevent underflow, as val will be
1160 		 * multiplied by 2).
1161 		 */
1162 		if (val < 0)
1163 			val = 0;
1164 		goto set_sndbuf;
1165 
1166 	case SO_RCVBUF:
1167 		/* Don't error on this BSD doesn't and if you think
1168 		 * about it this is right. Otherwise apps have to
1169 		 * play 'guess the biggest size' games. RCVBUF/SNDBUF
1170 		 * are treated in BSD as hints
1171 		 */
1172 		__sock_set_rcvbuf(sk, min_t(u32, val, READ_ONCE(sysctl_rmem_max)));
1173 		break;
1174 
1175 	case SO_RCVBUFFORCE:
1176 		if (!sockopt_capable(CAP_NET_ADMIN)) {
1177 			ret = -EPERM;
1178 			break;
1179 		}
1180 
1181 		/* No negative values (to prevent underflow, as val will be
1182 		 * multiplied by 2).
1183 		 */
1184 		__sock_set_rcvbuf(sk, max(val, 0));
1185 		break;
1186 
1187 	case SO_KEEPALIVE:
1188 		if (sk->sk_prot->keepalive)
1189 			sk->sk_prot->keepalive(sk, valbool);
1190 		sock_valbool_flag(sk, SOCK_KEEPOPEN, valbool);
1191 		break;
1192 
1193 	case SO_OOBINLINE:
1194 		sock_valbool_flag(sk, SOCK_URGINLINE, valbool);
1195 		break;
1196 
1197 	case SO_NO_CHECK:
1198 		sk->sk_no_check_tx = valbool;
1199 		break;
1200 
1201 	case SO_PRIORITY:
1202 		if ((val >= 0 && val <= 6) ||
1203 		    sockopt_ns_capable(sock_net(sk)->user_ns, CAP_NET_RAW) ||
1204 		    sockopt_ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
1205 			sk->sk_priority = val;
1206 		else
1207 			ret = -EPERM;
1208 		break;
1209 
1210 	case SO_LINGER:
1211 		if (optlen < sizeof(ling)) {
1212 			ret = -EINVAL;	/* 1003.1g */
1213 			break;
1214 		}
1215 		if (copy_from_sockptr(&ling, optval, sizeof(ling))) {
1216 			ret = -EFAULT;
1217 			break;
1218 		}
1219 		if (!ling.l_onoff)
1220 			sock_reset_flag(sk, SOCK_LINGER);
1221 		else {
1222 #if (BITS_PER_LONG == 32)
1223 			if ((unsigned int)ling.l_linger >= MAX_SCHEDULE_TIMEOUT/HZ)
1224 				sk->sk_lingertime = MAX_SCHEDULE_TIMEOUT;
1225 			else
1226 #endif
1227 				sk->sk_lingertime = (unsigned int)ling.l_linger * HZ;
1228 			sock_set_flag(sk, SOCK_LINGER);
1229 		}
1230 		break;
1231 
1232 	case SO_BSDCOMPAT:
1233 		break;
1234 
1235 	case SO_PASSCRED:
1236 		if (valbool)
1237 			set_bit(SOCK_PASSCRED, &sock->flags);
1238 		else
1239 			clear_bit(SOCK_PASSCRED, &sock->flags);
1240 		break;
1241 
1242 	case SO_TIMESTAMP_OLD:
1243 	case SO_TIMESTAMP_NEW:
1244 	case SO_TIMESTAMPNS_OLD:
1245 	case SO_TIMESTAMPNS_NEW:
1246 		sock_set_timestamp(sk, optname, valbool);
1247 		break;
1248 
1249 	case SO_TIMESTAMPING_NEW:
1250 	case SO_TIMESTAMPING_OLD:
1251 		if (optlen == sizeof(timestamping)) {
1252 			if (copy_from_sockptr(&timestamping, optval,
1253 					      sizeof(timestamping))) {
1254 				ret = -EFAULT;
1255 				break;
1256 			}
1257 		} else {
1258 			memset(&timestamping, 0, sizeof(timestamping));
1259 			timestamping.flags = val;
1260 		}
1261 		ret = sock_set_timestamping(sk, optname, timestamping);
1262 		break;
1263 
1264 	case SO_RCVLOWAT:
1265 		if (val < 0)
1266 			val = INT_MAX;
1267 		if (sock && sock->ops->set_rcvlowat)
1268 			ret = sock->ops->set_rcvlowat(sk, val);
1269 		else
1270 			WRITE_ONCE(sk->sk_rcvlowat, val ? : 1);
1271 		break;
1272 
1273 	case SO_RCVTIMEO_OLD:
1274 	case SO_RCVTIMEO_NEW:
1275 		ret = sock_set_timeout(&sk->sk_rcvtimeo, optval,
1276 				       optlen, optname == SO_RCVTIMEO_OLD);
1277 		break;
1278 
1279 	case SO_SNDTIMEO_OLD:
1280 	case SO_SNDTIMEO_NEW:
1281 		ret = sock_set_timeout(&sk->sk_sndtimeo, optval,
1282 				       optlen, optname == SO_SNDTIMEO_OLD);
1283 		break;
1284 
1285 	case SO_ATTACH_FILTER: {
1286 		struct sock_fprog fprog;
1287 
1288 		ret = copy_bpf_fprog_from_user(&fprog, optval, optlen);
1289 		if (!ret)
1290 			ret = sk_attach_filter(&fprog, sk);
1291 		break;
1292 	}
1293 	case SO_ATTACH_BPF:
1294 		ret = -EINVAL;
1295 		if (optlen == sizeof(u32)) {
1296 			u32 ufd;
1297 
1298 			ret = -EFAULT;
1299 			if (copy_from_sockptr(&ufd, optval, sizeof(ufd)))
1300 				break;
1301 
1302 			ret = sk_attach_bpf(ufd, sk);
1303 		}
1304 		break;
1305 
1306 	case SO_ATTACH_REUSEPORT_CBPF: {
1307 		struct sock_fprog fprog;
1308 
1309 		ret = copy_bpf_fprog_from_user(&fprog, optval, optlen);
1310 		if (!ret)
1311 			ret = sk_reuseport_attach_filter(&fprog, sk);
1312 		break;
1313 	}
1314 	case SO_ATTACH_REUSEPORT_EBPF:
1315 		ret = -EINVAL;
1316 		if (optlen == sizeof(u32)) {
1317 			u32 ufd;
1318 
1319 			ret = -EFAULT;
1320 			if (copy_from_sockptr(&ufd, optval, sizeof(ufd)))
1321 				break;
1322 
1323 			ret = sk_reuseport_attach_bpf(ufd, sk);
1324 		}
1325 		break;
1326 
1327 	case SO_DETACH_REUSEPORT_BPF:
1328 		ret = reuseport_detach_prog(sk);
1329 		break;
1330 
1331 	case SO_DETACH_FILTER:
1332 		ret = sk_detach_filter(sk);
1333 		break;
1334 
1335 	case SO_LOCK_FILTER:
1336 		if (sock_flag(sk, SOCK_FILTER_LOCKED) && !valbool)
1337 			ret = -EPERM;
1338 		else
1339 			sock_valbool_flag(sk, SOCK_FILTER_LOCKED, valbool);
1340 		break;
1341 
1342 	case SO_PASSSEC:
1343 		if (valbool)
1344 			set_bit(SOCK_PASSSEC, &sock->flags);
1345 		else
1346 			clear_bit(SOCK_PASSSEC, &sock->flags);
1347 		break;
1348 	case SO_MARK:
1349 		if (!sockopt_ns_capable(sock_net(sk)->user_ns, CAP_NET_RAW) &&
1350 		    !sockopt_ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) {
1351 			ret = -EPERM;
1352 			break;
1353 		}
1354 
1355 		__sock_set_mark(sk, val);
1356 		break;
1357 	case SO_RCVMARK:
1358 		if (!sockopt_ns_capable(sock_net(sk)->user_ns, CAP_NET_RAW) &&
1359 		    !sockopt_ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) {
1360 			ret = -EPERM;
1361 			break;
1362 		}
1363 
1364 		sock_valbool_flag(sk, SOCK_RCVMARK, valbool);
1365 		break;
1366 
1367 	case SO_RXQ_OVFL:
1368 		sock_valbool_flag(sk, SOCK_RXQ_OVFL, valbool);
1369 		break;
1370 
1371 	case SO_WIFI_STATUS:
1372 		sock_valbool_flag(sk, SOCK_WIFI_STATUS, valbool);
1373 		break;
1374 
1375 	case SO_PEEK_OFF:
1376 		if (sock->ops->set_peek_off)
1377 			ret = sock->ops->set_peek_off(sk, val);
1378 		else
1379 			ret = -EOPNOTSUPP;
1380 		break;
1381 
1382 	case SO_NOFCS:
1383 		sock_valbool_flag(sk, SOCK_NOFCS, valbool);
1384 		break;
1385 
1386 	case SO_SELECT_ERR_QUEUE:
1387 		sock_valbool_flag(sk, SOCK_SELECT_ERR_QUEUE, valbool);
1388 		break;
1389 
1390 #ifdef CONFIG_NET_RX_BUSY_POLL
1391 	case SO_BUSY_POLL:
1392 		/* allow unprivileged users to decrease the value */
1393 		if ((val > sk->sk_ll_usec) && !sockopt_capable(CAP_NET_ADMIN))
1394 			ret = -EPERM;
1395 		else {
1396 			if (val < 0)
1397 				ret = -EINVAL;
1398 			else
1399 				WRITE_ONCE(sk->sk_ll_usec, val);
1400 		}
1401 		break;
1402 	case SO_PREFER_BUSY_POLL:
1403 		if (valbool && !sockopt_capable(CAP_NET_ADMIN))
1404 			ret = -EPERM;
1405 		else
1406 			WRITE_ONCE(sk->sk_prefer_busy_poll, valbool);
1407 		break;
1408 	case SO_BUSY_POLL_BUDGET:
1409 		if (val > READ_ONCE(sk->sk_busy_poll_budget) && !sockopt_capable(CAP_NET_ADMIN)) {
1410 			ret = -EPERM;
1411 		} else {
1412 			if (val < 0 || val > U16_MAX)
1413 				ret = -EINVAL;
1414 			else
1415 				WRITE_ONCE(sk->sk_busy_poll_budget, val);
1416 		}
1417 		break;
1418 #endif
1419 
1420 	case SO_MAX_PACING_RATE:
1421 		{
1422 		unsigned long ulval = (val == ~0U) ? ~0UL : (unsigned int)val;
1423 
1424 		if (sizeof(ulval) != sizeof(val) &&
1425 		    optlen >= sizeof(ulval) &&
1426 		    copy_from_sockptr(&ulval, optval, sizeof(ulval))) {
1427 			ret = -EFAULT;
1428 			break;
1429 		}
1430 		if (ulval != ~0UL)
1431 			cmpxchg(&sk->sk_pacing_status,
1432 				SK_PACING_NONE,
1433 				SK_PACING_NEEDED);
1434 		sk->sk_max_pacing_rate = ulval;
1435 		sk->sk_pacing_rate = min(sk->sk_pacing_rate, ulval);
1436 		break;
1437 		}
1438 	case SO_INCOMING_CPU:
1439 		WRITE_ONCE(sk->sk_incoming_cpu, val);
1440 		break;
1441 
1442 	case SO_CNX_ADVICE:
1443 		if (val == 1)
1444 			dst_negative_advice(sk);
1445 		break;
1446 
1447 	case SO_ZEROCOPY:
1448 		if (sk->sk_family == PF_INET || sk->sk_family == PF_INET6) {
1449 			if (!(sk_is_tcp(sk) ||
1450 			      (sk->sk_type == SOCK_DGRAM &&
1451 			       sk->sk_protocol == IPPROTO_UDP)))
1452 				ret = -EOPNOTSUPP;
1453 		} else if (sk->sk_family != PF_RDS) {
1454 			ret = -EOPNOTSUPP;
1455 		}
1456 		if (!ret) {
1457 			if (val < 0 || val > 1)
1458 				ret = -EINVAL;
1459 			else
1460 				sock_valbool_flag(sk, SOCK_ZEROCOPY, valbool);
1461 		}
1462 		break;
1463 
1464 	case SO_TXTIME:
1465 		if (optlen != sizeof(struct sock_txtime)) {
1466 			ret = -EINVAL;
1467 			break;
1468 		} else if (copy_from_sockptr(&sk_txtime, optval,
1469 			   sizeof(struct sock_txtime))) {
1470 			ret = -EFAULT;
1471 			break;
1472 		} else if (sk_txtime.flags & ~SOF_TXTIME_FLAGS_MASK) {
1473 			ret = -EINVAL;
1474 			break;
1475 		}
1476 		/* CLOCK_MONOTONIC is only used by sch_fq, and this packet
1477 		 * scheduler has enough safe guards.
1478 		 */
1479 		if (sk_txtime.clockid != CLOCK_MONOTONIC &&
1480 		    !sockopt_ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) {
1481 			ret = -EPERM;
1482 			break;
1483 		}
1484 		sock_valbool_flag(sk, SOCK_TXTIME, true);
1485 		sk->sk_clockid = sk_txtime.clockid;
1486 		sk->sk_txtime_deadline_mode =
1487 			!!(sk_txtime.flags & SOF_TXTIME_DEADLINE_MODE);
1488 		sk->sk_txtime_report_errors =
1489 			!!(sk_txtime.flags & SOF_TXTIME_REPORT_ERRORS);
1490 		break;
1491 
1492 	case SO_BINDTOIFINDEX:
1493 		ret = sock_bindtoindex_locked(sk, val);
1494 		break;
1495 
1496 	case SO_BUF_LOCK:
1497 		if (val & ~SOCK_BUF_LOCK_MASK) {
1498 			ret = -EINVAL;
1499 			break;
1500 		}
1501 		sk->sk_userlocks = val | (sk->sk_userlocks &
1502 					  ~SOCK_BUF_LOCK_MASK);
1503 		break;
1504 
1505 	case SO_RESERVE_MEM:
1506 	{
1507 		int delta;
1508 
1509 		if (val < 0) {
1510 			ret = -EINVAL;
1511 			break;
1512 		}
1513 
1514 		delta = val - sk->sk_reserved_mem;
1515 		if (delta < 0)
1516 			sock_release_reserved_memory(sk, -delta);
1517 		else
1518 			ret = sock_reserve_memory(sk, delta);
1519 		break;
1520 	}
1521 
1522 	case SO_TXREHASH:
1523 		if (val < -1 || val > 1) {
1524 			ret = -EINVAL;
1525 			break;
1526 		}
1527 		/* Paired with READ_ONCE() in tcp_rtx_synack() */
1528 		WRITE_ONCE(sk->sk_txrehash, (u8)val);
1529 		break;
1530 
1531 	default:
1532 		ret = -ENOPROTOOPT;
1533 		break;
1534 	}
1535 	sockopt_release_sock(sk);
1536 	return ret;
1537 }
1538 
1539 int sock_setsockopt(struct socket *sock, int level, int optname,
1540 		    sockptr_t optval, unsigned int optlen)
1541 {
1542 	return sk_setsockopt(sock->sk, level, optname,
1543 			     optval, optlen);
1544 }
1545 EXPORT_SYMBOL(sock_setsockopt);
1546 
1547 static const struct cred *sk_get_peer_cred(struct sock *sk)
1548 {
1549 	const struct cred *cred;
1550 
1551 	spin_lock(&sk->sk_peer_lock);
1552 	cred = get_cred(sk->sk_peer_cred);
1553 	spin_unlock(&sk->sk_peer_lock);
1554 
1555 	return cred;
1556 }
1557 
1558 static void cred_to_ucred(struct pid *pid, const struct cred *cred,
1559 			  struct ucred *ucred)
1560 {
1561 	ucred->pid = pid_vnr(pid);
1562 	ucred->uid = ucred->gid = -1;
1563 	if (cred) {
1564 		struct user_namespace *current_ns = current_user_ns();
1565 
1566 		ucred->uid = from_kuid_munged(current_ns, cred->euid);
1567 		ucred->gid = from_kgid_munged(current_ns, cred->egid);
1568 	}
1569 }
1570 
1571 static int groups_to_user(sockptr_t dst, const struct group_info *src)
1572 {
1573 	struct user_namespace *user_ns = current_user_ns();
1574 	int i;
1575 
1576 	for (i = 0; i < src->ngroups; i++) {
1577 		gid_t gid = from_kgid_munged(user_ns, src->gid[i]);
1578 
1579 		if (copy_to_sockptr_offset(dst, i * sizeof(gid), &gid, sizeof(gid)))
1580 			return -EFAULT;
1581 	}
1582 
1583 	return 0;
1584 }
1585 
1586 int sk_getsockopt(struct sock *sk, int level, int optname,
1587 		  sockptr_t optval, sockptr_t optlen)
1588 {
1589 	struct socket *sock = sk->sk_socket;
1590 
1591 	union {
1592 		int val;
1593 		u64 val64;
1594 		unsigned long ulval;
1595 		struct linger ling;
1596 		struct old_timeval32 tm32;
1597 		struct __kernel_old_timeval tm;
1598 		struct  __kernel_sock_timeval stm;
1599 		struct sock_txtime txtime;
1600 		struct so_timestamping timestamping;
1601 	} v;
1602 
1603 	int lv = sizeof(int);
1604 	int len;
1605 
1606 	if (copy_from_sockptr(&len, optlen, sizeof(int)))
1607 		return -EFAULT;
1608 	if (len < 0)
1609 		return -EINVAL;
1610 
1611 	memset(&v, 0, sizeof(v));
1612 
1613 	switch (optname) {
1614 	case SO_DEBUG:
1615 		v.val = sock_flag(sk, SOCK_DBG);
1616 		break;
1617 
1618 	case SO_DONTROUTE:
1619 		v.val = sock_flag(sk, SOCK_LOCALROUTE);
1620 		break;
1621 
1622 	case SO_BROADCAST:
1623 		v.val = sock_flag(sk, SOCK_BROADCAST);
1624 		break;
1625 
1626 	case SO_SNDBUF:
1627 		v.val = sk->sk_sndbuf;
1628 		break;
1629 
1630 	case SO_RCVBUF:
1631 		v.val = sk->sk_rcvbuf;
1632 		break;
1633 
1634 	case SO_REUSEADDR:
1635 		v.val = sk->sk_reuse;
1636 		break;
1637 
1638 	case SO_REUSEPORT:
1639 		v.val = sk->sk_reuseport;
1640 		break;
1641 
1642 	case SO_KEEPALIVE:
1643 		v.val = sock_flag(sk, SOCK_KEEPOPEN);
1644 		break;
1645 
1646 	case SO_TYPE:
1647 		v.val = sk->sk_type;
1648 		break;
1649 
1650 	case SO_PROTOCOL:
1651 		v.val = sk->sk_protocol;
1652 		break;
1653 
1654 	case SO_DOMAIN:
1655 		v.val = sk->sk_family;
1656 		break;
1657 
1658 	case SO_ERROR:
1659 		v.val = -sock_error(sk);
1660 		if (v.val == 0)
1661 			v.val = xchg(&sk->sk_err_soft, 0);
1662 		break;
1663 
1664 	case SO_OOBINLINE:
1665 		v.val = sock_flag(sk, SOCK_URGINLINE);
1666 		break;
1667 
1668 	case SO_NO_CHECK:
1669 		v.val = sk->sk_no_check_tx;
1670 		break;
1671 
1672 	case SO_PRIORITY:
1673 		v.val = sk->sk_priority;
1674 		break;
1675 
1676 	case SO_LINGER:
1677 		lv		= sizeof(v.ling);
1678 		v.ling.l_onoff	= sock_flag(sk, SOCK_LINGER);
1679 		v.ling.l_linger	= sk->sk_lingertime / HZ;
1680 		break;
1681 
1682 	case SO_BSDCOMPAT:
1683 		break;
1684 
1685 	case SO_TIMESTAMP_OLD:
1686 		v.val = sock_flag(sk, SOCK_RCVTSTAMP) &&
1687 				!sock_flag(sk, SOCK_TSTAMP_NEW) &&
1688 				!sock_flag(sk, SOCK_RCVTSTAMPNS);
1689 		break;
1690 
1691 	case SO_TIMESTAMPNS_OLD:
1692 		v.val = sock_flag(sk, SOCK_RCVTSTAMPNS) && !sock_flag(sk, SOCK_TSTAMP_NEW);
1693 		break;
1694 
1695 	case SO_TIMESTAMP_NEW:
1696 		v.val = sock_flag(sk, SOCK_RCVTSTAMP) && sock_flag(sk, SOCK_TSTAMP_NEW);
1697 		break;
1698 
1699 	case SO_TIMESTAMPNS_NEW:
1700 		v.val = sock_flag(sk, SOCK_RCVTSTAMPNS) && sock_flag(sk, SOCK_TSTAMP_NEW);
1701 		break;
1702 
1703 	case SO_TIMESTAMPING_OLD:
1704 		lv = sizeof(v.timestamping);
1705 		v.timestamping.flags = sk->sk_tsflags;
1706 		v.timestamping.bind_phc = sk->sk_bind_phc;
1707 		break;
1708 
1709 	case SO_RCVTIMEO_OLD:
1710 	case SO_RCVTIMEO_NEW:
1711 		lv = sock_get_timeout(sk->sk_rcvtimeo, &v, SO_RCVTIMEO_OLD == optname);
1712 		break;
1713 
1714 	case SO_SNDTIMEO_OLD:
1715 	case SO_SNDTIMEO_NEW:
1716 		lv = sock_get_timeout(sk->sk_sndtimeo, &v, SO_SNDTIMEO_OLD == optname);
1717 		break;
1718 
1719 	case SO_RCVLOWAT:
1720 		v.val = sk->sk_rcvlowat;
1721 		break;
1722 
1723 	case SO_SNDLOWAT:
1724 		v.val = 1;
1725 		break;
1726 
1727 	case SO_PASSCRED:
1728 		v.val = !!test_bit(SOCK_PASSCRED, &sock->flags);
1729 		break;
1730 
1731 	case SO_PEERCRED:
1732 	{
1733 		struct ucred peercred;
1734 		if (len > sizeof(peercred))
1735 			len = sizeof(peercred);
1736 
1737 		spin_lock(&sk->sk_peer_lock);
1738 		cred_to_ucred(sk->sk_peer_pid, sk->sk_peer_cred, &peercred);
1739 		spin_unlock(&sk->sk_peer_lock);
1740 
1741 		if (copy_to_sockptr(optval, &peercred, len))
1742 			return -EFAULT;
1743 		goto lenout;
1744 	}
1745 
1746 	case SO_PEERGROUPS:
1747 	{
1748 		const struct cred *cred;
1749 		int ret, n;
1750 
1751 		cred = sk_get_peer_cred(sk);
1752 		if (!cred)
1753 			return -ENODATA;
1754 
1755 		n = cred->group_info->ngroups;
1756 		if (len < n * sizeof(gid_t)) {
1757 			len = n * sizeof(gid_t);
1758 			put_cred(cred);
1759 			return copy_to_sockptr(optlen, &len, sizeof(int)) ? -EFAULT : -ERANGE;
1760 		}
1761 		len = n * sizeof(gid_t);
1762 
1763 		ret = groups_to_user(optval, cred->group_info);
1764 		put_cred(cred);
1765 		if (ret)
1766 			return ret;
1767 		goto lenout;
1768 	}
1769 
1770 	case SO_PEERNAME:
1771 	{
1772 		char address[128];
1773 
1774 		lv = sock->ops->getname(sock, (struct sockaddr *)address, 2);
1775 		if (lv < 0)
1776 			return -ENOTCONN;
1777 		if (lv < len)
1778 			return -EINVAL;
1779 		if (copy_to_sockptr(optval, address, len))
1780 			return -EFAULT;
1781 		goto lenout;
1782 	}
1783 
1784 	/* Dubious BSD thing... Probably nobody even uses it, but
1785 	 * the UNIX standard wants it for whatever reason... -DaveM
1786 	 */
1787 	case SO_ACCEPTCONN:
1788 		v.val = sk->sk_state == TCP_LISTEN;
1789 		break;
1790 
1791 	case SO_PASSSEC:
1792 		v.val = !!test_bit(SOCK_PASSSEC, &sock->flags);
1793 		break;
1794 
1795 	case SO_PEERSEC:
1796 		return security_socket_getpeersec_stream(sock,
1797 							 optval, optlen, len);
1798 
1799 	case SO_MARK:
1800 		v.val = sk->sk_mark;
1801 		break;
1802 
1803 	case SO_RCVMARK:
1804 		v.val = sock_flag(sk, SOCK_RCVMARK);
1805 		break;
1806 
1807 	case SO_RXQ_OVFL:
1808 		v.val = sock_flag(sk, SOCK_RXQ_OVFL);
1809 		break;
1810 
1811 	case SO_WIFI_STATUS:
1812 		v.val = sock_flag(sk, SOCK_WIFI_STATUS);
1813 		break;
1814 
1815 	case SO_PEEK_OFF:
1816 		if (!sock->ops->set_peek_off)
1817 			return -EOPNOTSUPP;
1818 
1819 		v.val = sk->sk_peek_off;
1820 		break;
1821 	case SO_NOFCS:
1822 		v.val = sock_flag(sk, SOCK_NOFCS);
1823 		break;
1824 
1825 	case SO_BINDTODEVICE:
1826 		return sock_getbindtodevice(sk, optval, optlen, len);
1827 
1828 	case SO_GET_FILTER:
1829 		len = sk_get_filter(sk, optval, len);
1830 		if (len < 0)
1831 			return len;
1832 
1833 		goto lenout;
1834 
1835 	case SO_LOCK_FILTER:
1836 		v.val = sock_flag(sk, SOCK_FILTER_LOCKED);
1837 		break;
1838 
1839 	case SO_BPF_EXTENSIONS:
1840 		v.val = bpf_tell_extensions();
1841 		break;
1842 
1843 	case SO_SELECT_ERR_QUEUE:
1844 		v.val = sock_flag(sk, SOCK_SELECT_ERR_QUEUE);
1845 		break;
1846 
1847 #ifdef CONFIG_NET_RX_BUSY_POLL
1848 	case SO_BUSY_POLL:
1849 		v.val = sk->sk_ll_usec;
1850 		break;
1851 	case SO_PREFER_BUSY_POLL:
1852 		v.val = READ_ONCE(sk->sk_prefer_busy_poll);
1853 		break;
1854 #endif
1855 
1856 	case SO_MAX_PACING_RATE:
1857 		if (sizeof(v.ulval) != sizeof(v.val) && len >= sizeof(v.ulval)) {
1858 			lv = sizeof(v.ulval);
1859 			v.ulval = sk->sk_max_pacing_rate;
1860 		} else {
1861 			/* 32bit version */
1862 			v.val = min_t(unsigned long, sk->sk_max_pacing_rate, ~0U);
1863 		}
1864 		break;
1865 
1866 	case SO_INCOMING_CPU:
1867 		v.val = READ_ONCE(sk->sk_incoming_cpu);
1868 		break;
1869 
1870 	case SO_MEMINFO:
1871 	{
1872 		u32 meminfo[SK_MEMINFO_VARS];
1873 
1874 		sk_get_meminfo(sk, meminfo);
1875 
1876 		len = min_t(unsigned int, len, sizeof(meminfo));
1877 		if (copy_to_sockptr(optval, &meminfo, len))
1878 			return -EFAULT;
1879 
1880 		goto lenout;
1881 	}
1882 
1883 #ifdef CONFIG_NET_RX_BUSY_POLL
1884 	case SO_INCOMING_NAPI_ID:
1885 		v.val = READ_ONCE(sk->sk_napi_id);
1886 
1887 		/* aggregate non-NAPI IDs down to 0 */
1888 		if (v.val < MIN_NAPI_ID)
1889 			v.val = 0;
1890 
1891 		break;
1892 #endif
1893 
1894 	case SO_COOKIE:
1895 		lv = sizeof(u64);
1896 		if (len < lv)
1897 			return -EINVAL;
1898 		v.val64 = sock_gen_cookie(sk);
1899 		break;
1900 
1901 	case SO_ZEROCOPY:
1902 		v.val = sock_flag(sk, SOCK_ZEROCOPY);
1903 		break;
1904 
1905 	case SO_TXTIME:
1906 		lv = sizeof(v.txtime);
1907 		v.txtime.clockid = sk->sk_clockid;
1908 		v.txtime.flags |= sk->sk_txtime_deadline_mode ?
1909 				  SOF_TXTIME_DEADLINE_MODE : 0;
1910 		v.txtime.flags |= sk->sk_txtime_report_errors ?
1911 				  SOF_TXTIME_REPORT_ERRORS : 0;
1912 		break;
1913 
1914 	case SO_BINDTOIFINDEX:
1915 		v.val = READ_ONCE(sk->sk_bound_dev_if);
1916 		break;
1917 
1918 	case SO_NETNS_COOKIE:
1919 		lv = sizeof(u64);
1920 		if (len != lv)
1921 			return -EINVAL;
1922 		v.val64 = sock_net(sk)->net_cookie;
1923 		break;
1924 
1925 	case SO_BUF_LOCK:
1926 		v.val = sk->sk_userlocks & SOCK_BUF_LOCK_MASK;
1927 		break;
1928 
1929 	case SO_RESERVE_MEM:
1930 		v.val = sk->sk_reserved_mem;
1931 		break;
1932 
1933 	case SO_TXREHASH:
1934 		v.val = sk->sk_txrehash;
1935 		break;
1936 
1937 	default:
1938 		/* We implement the SO_SNDLOWAT etc to not be settable
1939 		 * (1003.1g 7).
1940 		 */
1941 		return -ENOPROTOOPT;
1942 	}
1943 
1944 	if (len > lv)
1945 		len = lv;
1946 	if (copy_to_sockptr(optval, &v, len))
1947 		return -EFAULT;
1948 lenout:
1949 	if (copy_to_sockptr(optlen, &len, sizeof(int)))
1950 		return -EFAULT;
1951 	return 0;
1952 }
1953 
1954 int sock_getsockopt(struct socket *sock, int level, int optname,
1955 		    char __user *optval, int __user *optlen)
1956 {
1957 	return sk_getsockopt(sock->sk, level, optname,
1958 			     USER_SOCKPTR(optval),
1959 			     USER_SOCKPTR(optlen));
1960 }
1961 
1962 /*
1963  * Initialize an sk_lock.
1964  *
1965  * (We also register the sk_lock with the lock validator.)
1966  */
1967 static inline void sock_lock_init(struct sock *sk)
1968 {
1969 	if (sk->sk_kern_sock)
1970 		sock_lock_init_class_and_name(
1971 			sk,
1972 			af_family_kern_slock_key_strings[sk->sk_family],
1973 			af_family_kern_slock_keys + sk->sk_family,
1974 			af_family_kern_key_strings[sk->sk_family],
1975 			af_family_kern_keys + sk->sk_family);
1976 	else
1977 		sock_lock_init_class_and_name(
1978 			sk,
1979 			af_family_slock_key_strings[sk->sk_family],
1980 			af_family_slock_keys + sk->sk_family,
1981 			af_family_key_strings[sk->sk_family],
1982 			af_family_keys + sk->sk_family);
1983 }
1984 
1985 /*
1986  * Copy all fields from osk to nsk but nsk->sk_refcnt must not change yet,
1987  * even temporarly, because of RCU lookups. sk_node should also be left as is.
1988  * We must not copy fields between sk_dontcopy_begin and sk_dontcopy_end
1989  */
1990 static void sock_copy(struct sock *nsk, const struct sock *osk)
1991 {
1992 	const struct proto *prot = READ_ONCE(osk->sk_prot);
1993 #ifdef CONFIG_SECURITY_NETWORK
1994 	void *sptr = nsk->sk_security;
1995 #endif
1996 
1997 	/* If we move sk_tx_queue_mapping out of the private section,
1998 	 * we must check if sk_tx_queue_clear() is called after
1999 	 * sock_copy() in sk_clone_lock().
2000 	 */
2001 	BUILD_BUG_ON(offsetof(struct sock, sk_tx_queue_mapping) <
2002 		     offsetof(struct sock, sk_dontcopy_begin) ||
2003 		     offsetof(struct sock, sk_tx_queue_mapping) >=
2004 		     offsetof(struct sock, sk_dontcopy_end));
2005 
2006 	memcpy(nsk, osk, offsetof(struct sock, sk_dontcopy_begin));
2007 
2008 	memcpy(&nsk->sk_dontcopy_end, &osk->sk_dontcopy_end,
2009 	       prot->obj_size - offsetof(struct sock, sk_dontcopy_end));
2010 
2011 #ifdef CONFIG_SECURITY_NETWORK
2012 	nsk->sk_security = sptr;
2013 	security_sk_clone(osk, nsk);
2014 #endif
2015 }
2016 
2017 static struct sock *sk_prot_alloc(struct proto *prot, gfp_t priority,
2018 		int family)
2019 {
2020 	struct sock *sk;
2021 	struct kmem_cache *slab;
2022 
2023 	slab = prot->slab;
2024 	if (slab != NULL) {
2025 		sk = kmem_cache_alloc(slab, priority & ~__GFP_ZERO);
2026 		if (!sk)
2027 			return sk;
2028 		if (want_init_on_alloc(priority))
2029 			sk_prot_clear_nulls(sk, prot->obj_size);
2030 	} else
2031 		sk = kmalloc(prot->obj_size, priority);
2032 
2033 	if (sk != NULL) {
2034 		if (security_sk_alloc(sk, family, priority))
2035 			goto out_free;
2036 
2037 		if (!try_module_get(prot->owner))
2038 			goto out_free_sec;
2039 	}
2040 
2041 	return sk;
2042 
2043 out_free_sec:
2044 	security_sk_free(sk);
2045 out_free:
2046 	if (slab != NULL)
2047 		kmem_cache_free(slab, sk);
2048 	else
2049 		kfree(sk);
2050 	return NULL;
2051 }
2052 
2053 static void sk_prot_free(struct proto *prot, struct sock *sk)
2054 {
2055 	struct kmem_cache *slab;
2056 	struct module *owner;
2057 
2058 	owner = prot->owner;
2059 	slab = prot->slab;
2060 
2061 	cgroup_sk_free(&sk->sk_cgrp_data);
2062 	mem_cgroup_sk_free(sk);
2063 	security_sk_free(sk);
2064 	if (slab != NULL)
2065 		kmem_cache_free(slab, sk);
2066 	else
2067 		kfree(sk);
2068 	module_put(owner);
2069 }
2070 
2071 /**
2072  *	sk_alloc - All socket objects are allocated here
2073  *	@net: the applicable net namespace
2074  *	@family: protocol family
2075  *	@priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
2076  *	@prot: struct proto associated with this new sock instance
2077  *	@kern: is this to be a kernel socket?
2078  */
2079 struct sock *sk_alloc(struct net *net, int family, gfp_t priority,
2080 		      struct proto *prot, int kern)
2081 {
2082 	struct sock *sk;
2083 
2084 	sk = sk_prot_alloc(prot, priority | __GFP_ZERO, family);
2085 	if (sk) {
2086 		sk->sk_family = family;
2087 		/*
2088 		 * See comment in struct sock definition to understand
2089 		 * why we need sk_prot_creator -acme
2090 		 */
2091 		sk->sk_prot = sk->sk_prot_creator = prot;
2092 		sk->sk_kern_sock = kern;
2093 		sock_lock_init(sk);
2094 		sk->sk_net_refcnt = kern ? 0 : 1;
2095 		if (likely(sk->sk_net_refcnt)) {
2096 			get_net_track(net, &sk->ns_tracker, priority);
2097 			sock_inuse_add(net, 1);
2098 		}
2099 
2100 		sock_net_set(sk, net);
2101 		refcount_set(&sk->sk_wmem_alloc, 1);
2102 
2103 		mem_cgroup_sk_alloc(sk);
2104 		cgroup_sk_alloc(&sk->sk_cgrp_data);
2105 		sock_update_classid(&sk->sk_cgrp_data);
2106 		sock_update_netprioidx(&sk->sk_cgrp_data);
2107 		sk_tx_queue_clear(sk);
2108 	}
2109 
2110 	return sk;
2111 }
2112 EXPORT_SYMBOL(sk_alloc);
2113 
2114 /* Sockets having SOCK_RCU_FREE will call this function after one RCU
2115  * grace period. This is the case for UDP sockets and TCP listeners.
2116  */
2117 static void __sk_destruct(struct rcu_head *head)
2118 {
2119 	struct sock *sk = container_of(head, struct sock, sk_rcu);
2120 	struct sk_filter *filter;
2121 
2122 	if (sk->sk_destruct)
2123 		sk->sk_destruct(sk);
2124 
2125 	filter = rcu_dereference_check(sk->sk_filter,
2126 				       refcount_read(&sk->sk_wmem_alloc) == 0);
2127 	if (filter) {
2128 		sk_filter_uncharge(sk, filter);
2129 		RCU_INIT_POINTER(sk->sk_filter, NULL);
2130 	}
2131 
2132 	sock_disable_timestamp(sk, SK_FLAGS_TIMESTAMP);
2133 
2134 #ifdef CONFIG_BPF_SYSCALL
2135 	bpf_sk_storage_free(sk);
2136 #endif
2137 
2138 	if (atomic_read(&sk->sk_omem_alloc))
2139 		pr_debug("%s: optmem leakage (%d bytes) detected\n",
2140 			 __func__, atomic_read(&sk->sk_omem_alloc));
2141 
2142 	if (sk->sk_frag.page) {
2143 		put_page(sk->sk_frag.page);
2144 		sk->sk_frag.page = NULL;
2145 	}
2146 
2147 	/* We do not need to acquire sk->sk_peer_lock, we are the last user. */
2148 	put_cred(sk->sk_peer_cred);
2149 	put_pid(sk->sk_peer_pid);
2150 
2151 	if (likely(sk->sk_net_refcnt))
2152 		put_net_track(sock_net(sk), &sk->ns_tracker);
2153 	sk_prot_free(sk->sk_prot_creator, sk);
2154 }
2155 
2156 void sk_destruct(struct sock *sk)
2157 {
2158 	bool use_call_rcu = sock_flag(sk, SOCK_RCU_FREE);
2159 
2160 	if (rcu_access_pointer(sk->sk_reuseport_cb)) {
2161 		reuseport_detach_sock(sk);
2162 		use_call_rcu = true;
2163 	}
2164 
2165 	if (use_call_rcu)
2166 		call_rcu(&sk->sk_rcu, __sk_destruct);
2167 	else
2168 		__sk_destruct(&sk->sk_rcu);
2169 }
2170 
2171 static void __sk_free(struct sock *sk)
2172 {
2173 	if (likely(sk->sk_net_refcnt))
2174 		sock_inuse_add(sock_net(sk), -1);
2175 
2176 	if (unlikely(sk->sk_net_refcnt && sock_diag_has_destroy_listeners(sk)))
2177 		sock_diag_broadcast_destroy(sk);
2178 	else
2179 		sk_destruct(sk);
2180 }
2181 
2182 void sk_free(struct sock *sk)
2183 {
2184 	/*
2185 	 * We subtract one from sk_wmem_alloc and can know if
2186 	 * some packets are still in some tx queue.
2187 	 * If not null, sock_wfree() will call __sk_free(sk) later
2188 	 */
2189 	if (refcount_dec_and_test(&sk->sk_wmem_alloc))
2190 		__sk_free(sk);
2191 }
2192 EXPORT_SYMBOL(sk_free);
2193 
2194 static void sk_init_common(struct sock *sk)
2195 {
2196 	skb_queue_head_init(&sk->sk_receive_queue);
2197 	skb_queue_head_init(&sk->sk_write_queue);
2198 	skb_queue_head_init(&sk->sk_error_queue);
2199 
2200 	rwlock_init(&sk->sk_callback_lock);
2201 	lockdep_set_class_and_name(&sk->sk_receive_queue.lock,
2202 			af_rlock_keys + sk->sk_family,
2203 			af_family_rlock_key_strings[sk->sk_family]);
2204 	lockdep_set_class_and_name(&sk->sk_write_queue.lock,
2205 			af_wlock_keys + sk->sk_family,
2206 			af_family_wlock_key_strings[sk->sk_family]);
2207 	lockdep_set_class_and_name(&sk->sk_error_queue.lock,
2208 			af_elock_keys + sk->sk_family,
2209 			af_family_elock_key_strings[sk->sk_family]);
2210 	lockdep_set_class_and_name(&sk->sk_callback_lock,
2211 			af_callback_keys + sk->sk_family,
2212 			af_family_clock_key_strings[sk->sk_family]);
2213 }
2214 
2215 /**
2216  *	sk_clone_lock - clone a socket, and lock its clone
2217  *	@sk: the socket to clone
2218  *	@priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
2219  *
2220  *	Caller must unlock socket even in error path (bh_unlock_sock(newsk))
2221  */
2222 struct sock *sk_clone_lock(const struct sock *sk, const gfp_t priority)
2223 {
2224 	struct proto *prot = READ_ONCE(sk->sk_prot);
2225 	struct sk_filter *filter;
2226 	bool is_charged = true;
2227 	struct sock *newsk;
2228 
2229 	newsk = sk_prot_alloc(prot, priority, sk->sk_family);
2230 	if (!newsk)
2231 		goto out;
2232 
2233 	sock_copy(newsk, sk);
2234 
2235 	newsk->sk_prot_creator = prot;
2236 
2237 	/* SANITY */
2238 	if (likely(newsk->sk_net_refcnt)) {
2239 		get_net_track(sock_net(newsk), &newsk->ns_tracker, priority);
2240 		sock_inuse_add(sock_net(newsk), 1);
2241 	}
2242 	sk_node_init(&newsk->sk_node);
2243 	sock_lock_init(newsk);
2244 	bh_lock_sock(newsk);
2245 	newsk->sk_backlog.head	= newsk->sk_backlog.tail = NULL;
2246 	newsk->sk_backlog.len = 0;
2247 
2248 	atomic_set(&newsk->sk_rmem_alloc, 0);
2249 
2250 	/* sk_wmem_alloc set to one (see sk_free() and sock_wfree()) */
2251 	refcount_set(&newsk->sk_wmem_alloc, 1);
2252 
2253 	atomic_set(&newsk->sk_omem_alloc, 0);
2254 	sk_init_common(newsk);
2255 
2256 	newsk->sk_dst_cache	= NULL;
2257 	newsk->sk_dst_pending_confirm = 0;
2258 	newsk->sk_wmem_queued	= 0;
2259 	newsk->sk_forward_alloc = 0;
2260 	newsk->sk_reserved_mem  = 0;
2261 	atomic_set(&newsk->sk_drops, 0);
2262 	newsk->sk_send_head	= NULL;
2263 	newsk->sk_userlocks	= sk->sk_userlocks & ~SOCK_BINDPORT_LOCK;
2264 	atomic_set(&newsk->sk_zckey, 0);
2265 
2266 	sock_reset_flag(newsk, SOCK_DONE);
2267 
2268 	/* sk->sk_memcg will be populated at accept() time */
2269 	newsk->sk_memcg = NULL;
2270 
2271 	cgroup_sk_clone(&newsk->sk_cgrp_data);
2272 
2273 	rcu_read_lock();
2274 	filter = rcu_dereference(sk->sk_filter);
2275 	if (filter != NULL)
2276 		/* though it's an empty new sock, the charging may fail
2277 		 * if sysctl_optmem_max was changed between creation of
2278 		 * original socket and cloning
2279 		 */
2280 		is_charged = sk_filter_charge(newsk, filter);
2281 	RCU_INIT_POINTER(newsk->sk_filter, filter);
2282 	rcu_read_unlock();
2283 
2284 	if (unlikely(!is_charged || xfrm_sk_clone_policy(newsk, sk))) {
2285 		/* We need to make sure that we don't uncharge the new
2286 		 * socket if we couldn't charge it in the first place
2287 		 * as otherwise we uncharge the parent's filter.
2288 		 */
2289 		if (!is_charged)
2290 			RCU_INIT_POINTER(newsk->sk_filter, NULL);
2291 		sk_free_unlock_clone(newsk);
2292 		newsk = NULL;
2293 		goto out;
2294 	}
2295 	RCU_INIT_POINTER(newsk->sk_reuseport_cb, NULL);
2296 
2297 	if (bpf_sk_storage_clone(sk, newsk)) {
2298 		sk_free_unlock_clone(newsk);
2299 		newsk = NULL;
2300 		goto out;
2301 	}
2302 
2303 	/* Clear sk_user_data if parent had the pointer tagged
2304 	 * as not suitable for copying when cloning.
2305 	 */
2306 	if (sk_user_data_is_nocopy(newsk))
2307 		newsk->sk_user_data = NULL;
2308 
2309 	newsk->sk_err	   = 0;
2310 	newsk->sk_err_soft = 0;
2311 	newsk->sk_priority = 0;
2312 	newsk->sk_incoming_cpu = raw_smp_processor_id();
2313 
2314 	/* Before updating sk_refcnt, we must commit prior changes to memory
2315 	 * (Documentation/RCU/rculist_nulls.rst for details)
2316 	 */
2317 	smp_wmb();
2318 	refcount_set(&newsk->sk_refcnt, 2);
2319 
2320 	/* Increment the counter in the same struct proto as the master
2321 	 * sock (sk_refcnt_debug_inc uses newsk->sk_prot->socks, that
2322 	 * is the same as sk->sk_prot->socks, as this field was copied
2323 	 * with memcpy).
2324 	 *
2325 	 * This _changes_ the previous behaviour, where
2326 	 * tcp_create_openreq_child always was incrementing the
2327 	 * equivalent to tcp_prot->socks (inet_sock_nr), so this have
2328 	 * to be taken into account in all callers. -acme
2329 	 */
2330 	sk_refcnt_debug_inc(newsk);
2331 	sk_set_socket(newsk, NULL);
2332 	sk_tx_queue_clear(newsk);
2333 	RCU_INIT_POINTER(newsk->sk_wq, NULL);
2334 
2335 	if (newsk->sk_prot->sockets_allocated)
2336 		sk_sockets_allocated_inc(newsk);
2337 
2338 	if (sock_needs_netstamp(sk) && newsk->sk_flags & SK_FLAGS_TIMESTAMP)
2339 		net_enable_timestamp();
2340 out:
2341 	return newsk;
2342 }
2343 EXPORT_SYMBOL_GPL(sk_clone_lock);
2344 
2345 void sk_free_unlock_clone(struct sock *sk)
2346 {
2347 	/* It is still raw copy of parent, so invalidate
2348 	 * destructor and make plain sk_free() */
2349 	sk->sk_destruct = NULL;
2350 	bh_unlock_sock(sk);
2351 	sk_free(sk);
2352 }
2353 EXPORT_SYMBOL_GPL(sk_free_unlock_clone);
2354 
2355 static void sk_trim_gso_size(struct sock *sk)
2356 {
2357 	if (sk->sk_gso_max_size <= GSO_LEGACY_MAX_SIZE)
2358 		return;
2359 #if IS_ENABLED(CONFIG_IPV6)
2360 	if (sk->sk_family == AF_INET6 &&
2361 	    sk_is_tcp(sk) &&
2362 	    !ipv6_addr_v4mapped(&sk->sk_v6_rcv_saddr))
2363 		return;
2364 #endif
2365 	sk->sk_gso_max_size = GSO_LEGACY_MAX_SIZE;
2366 }
2367 
2368 void sk_setup_caps(struct sock *sk, struct dst_entry *dst)
2369 {
2370 	u32 max_segs = 1;
2371 
2372 	sk_dst_set(sk, dst);
2373 	sk->sk_route_caps = dst->dev->features;
2374 	if (sk_is_tcp(sk))
2375 		sk->sk_route_caps |= NETIF_F_GSO;
2376 	if (sk->sk_route_caps & NETIF_F_GSO)
2377 		sk->sk_route_caps |= NETIF_F_GSO_SOFTWARE;
2378 	if (unlikely(sk->sk_gso_disabled))
2379 		sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
2380 	if (sk_can_gso(sk)) {
2381 		if (dst->header_len && !xfrm_dst_offload_ok(dst)) {
2382 			sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
2383 		} else {
2384 			sk->sk_route_caps |= NETIF_F_SG | NETIF_F_HW_CSUM;
2385 			/* pairs with the WRITE_ONCE() in netif_set_gso_max_size() */
2386 			sk->sk_gso_max_size = READ_ONCE(dst->dev->gso_max_size);
2387 			sk_trim_gso_size(sk);
2388 			sk->sk_gso_max_size -= (MAX_TCP_HEADER + 1);
2389 			/* pairs with the WRITE_ONCE() in netif_set_gso_max_segs() */
2390 			max_segs = max_t(u32, READ_ONCE(dst->dev->gso_max_segs), 1);
2391 		}
2392 	}
2393 	sk->sk_gso_max_segs = max_segs;
2394 }
2395 EXPORT_SYMBOL_GPL(sk_setup_caps);
2396 
2397 /*
2398  *	Simple resource managers for sockets.
2399  */
2400 
2401 
2402 /*
2403  * Write buffer destructor automatically called from kfree_skb.
2404  */
2405 void sock_wfree(struct sk_buff *skb)
2406 {
2407 	struct sock *sk = skb->sk;
2408 	unsigned int len = skb->truesize;
2409 	bool free;
2410 
2411 	if (!sock_flag(sk, SOCK_USE_WRITE_QUEUE)) {
2412 		if (sock_flag(sk, SOCK_RCU_FREE) &&
2413 		    sk->sk_write_space == sock_def_write_space) {
2414 			rcu_read_lock();
2415 			free = refcount_sub_and_test(len, &sk->sk_wmem_alloc);
2416 			sock_def_write_space_wfree(sk);
2417 			rcu_read_unlock();
2418 			if (unlikely(free))
2419 				__sk_free(sk);
2420 			return;
2421 		}
2422 
2423 		/*
2424 		 * Keep a reference on sk_wmem_alloc, this will be released
2425 		 * after sk_write_space() call
2426 		 */
2427 		WARN_ON(refcount_sub_and_test(len - 1, &sk->sk_wmem_alloc));
2428 		sk->sk_write_space(sk);
2429 		len = 1;
2430 	}
2431 	/*
2432 	 * if sk_wmem_alloc reaches 0, we must finish what sk_free()
2433 	 * could not do because of in-flight packets
2434 	 */
2435 	if (refcount_sub_and_test(len, &sk->sk_wmem_alloc))
2436 		__sk_free(sk);
2437 }
2438 EXPORT_SYMBOL(sock_wfree);
2439 
2440 /* This variant of sock_wfree() is used by TCP,
2441  * since it sets SOCK_USE_WRITE_QUEUE.
2442  */
2443 void __sock_wfree(struct sk_buff *skb)
2444 {
2445 	struct sock *sk = skb->sk;
2446 
2447 	if (refcount_sub_and_test(skb->truesize, &sk->sk_wmem_alloc))
2448 		__sk_free(sk);
2449 }
2450 
2451 void skb_set_owner_w(struct sk_buff *skb, struct sock *sk)
2452 {
2453 	skb_orphan(skb);
2454 	skb->sk = sk;
2455 #ifdef CONFIG_INET
2456 	if (unlikely(!sk_fullsock(sk))) {
2457 		skb->destructor = sock_edemux;
2458 		sock_hold(sk);
2459 		return;
2460 	}
2461 #endif
2462 	skb->destructor = sock_wfree;
2463 	skb_set_hash_from_sk(skb, sk);
2464 	/*
2465 	 * We used to take a refcount on sk, but following operation
2466 	 * is enough to guarantee sk_free() wont free this sock until
2467 	 * all in-flight packets are completed
2468 	 */
2469 	refcount_add(skb->truesize, &sk->sk_wmem_alloc);
2470 }
2471 EXPORT_SYMBOL(skb_set_owner_w);
2472 
2473 static bool can_skb_orphan_partial(const struct sk_buff *skb)
2474 {
2475 #ifdef CONFIG_TLS_DEVICE
2476 	/* Drivers depend on in-order delivery for crypto offload,
2477 	 * partial orphan breaks out-of-order-OK logic.
2478 	 */
2479 	if (skb->decrypted)
2480 		return false;
2481 #endif
2482 	return (skb->destructor == sock_wfree ||
2483 		(IS_ENABLED(CONFIG_INET) && skb->destructor == tcp_wfree));
2484 }
2485 
2486 /* This helper is used by netem, as it can hold packets in its
2487  * delay queue. We want to allow the owner socket to send more
2488  * packets, as if they were already TX completed by a typical driver.
2489  * But we also want to keep skb->sk set because some packet schedulers
2490  * rely on it (sch_fq for example).
2491  */
2492 void skb_orphan_partial(struct sk_buff *skb)
2493 {
2494 	if (skb_is_tcp_pure_ack(skb))
2495 		return;
2496 
2497 	if (can_skb_orphan_partial(skb) && skb_set_owner_sk_safe(skb, skb->sk))
2498 		return;
2499 
2500 	skb_orphan(skb);
2501 }
2502 EXPORT_SYMBOL(skb_orphan_partial);
2503 
2504 /*
2505  * Read buffer destructor automatically called from kfree_skb.
2506  */
2507 void sock_rfree(struct sk_buff *skb)
2508 {
2509 	struct sock *sk = skb->sk;
2510 	unsigned int len = skb->truesize;
2511 
2512 	atomic_sub(len, &sk->sk_rmem_alloc);
2513 	sk_mem_uncharge(sk, len);
2514 }
2515 EXPORT_SYMBOL(sock_rfree);
2516 
2517 /*
2518  * Buffer destructor for skbs that are not used directly in read or write
2519  * path, e.g. for error handler skbs. Automatically called from kfree_skb.
2520  */
2521 void sock_efree(struct sk_buff *skb)
2522 {
2523 	sock_put(skb->sk);
2524 }
2525 EXPORT_SYMBOL(sock_efree);
2526 
2527 /* Buffer destructor for prefetch/receive path where reference count may
2528  * not be held, e.g. for listen sockets.
2529  */
2530 #ifdef CONFIG_INET
2531 void sock_pfree(struct sk_buff *skb)
2532 {
2533 	if (sk_is_refcounted(skb->sk))
2534 		sock_gen_put(skb->sk);
2535 }
2536 EXPORT_SYMBOL(sock_pfree);
2537 #endif /* CONFIG_INET */
2538 
2539 kuid_t sock_i_uid(struct sock *sk)
2540 {
2541 	kuid_t uid;
2542 
2543 	read_lock_bh(&sk->sk_callback_lock);
2544 	uid = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_uid : GLOBAL_ROOT_UID;
2545 	read_unlock_bh(&sk->sk_callback_lock);
2546 	return uid;
2547 }
2548 EXPORT_SYMBOL(sock_i_uid);
2549 
2550 unsigned long sock_i_ino(struct sock *sk)
2551 {
2552 	unsigned long ino;
2553 
2554 	read_lock_bh(&sk->sk_callback_lock);
2555 	ino = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_ino : 0;
2556 	read_unlock_bh(&sk->sk_callback_lock);
2557 	return ino;
2558 }
2559 EXPORT_SYMBOL(sock_i_ino);
2560 
2561 /*
2562  * Allocate a skb from the socket's send buffer.
2563  */
2564 struct sk_buff *sock_wmalloc(struct sock *sk, unsigned long size, int force,
2565 			     gfp_t priority)
2566 {
2567 	if (force ||
2568 	    refcount_read(&sk->sk_wmem_alloc) < READ_ONCE(sk->sk_sndbuf)) {
2569 		struct sk_buff *skb = alloc_skb(size, priority);
2570 
2571 		if (skb) {
2572 			skb_set_owner_w(skb, sk);
2573 			return skb;
2574 		}
2575 	}
2576 	return NULL;
2577 }
2578 EXPORT_SYMBOL(sock_wmalloc);
2579 
2580 static void sock_ofree(struct sk_buff *skb)
2581 {
2582 	struct sock *sk = skb->sk;
2583 
2584 	atomic_sub(skb->truesize, &sk->sk_omem_alloc);
2585 }
2586 
2587 struct sk_buff *sock_omalloc(struct sock *sk, unsigned long size,
2588 			     gfp_t priority)
2589 {
2590 	struct sk_buff *skb;
2591 
2592 	/* small safe race: SKB_TRUESIZE may differ from final skb->truesize */
2593 	if (atomic_read(&sk->sk_omem_alloc) + SKB_TRUESIZE(size) >
2594 	    READ_ONCE(sysctl_optmem_max))
2595 		return NULL;
2596 
2597 	skb = alloc_skb(size, priority);
2598 	if (!skb)
2599 		return NULL;
2600 
2601 	atomic_add(skb->truesize, &sk->sk_omem_alloc);
2602 	skb->sk = sk;
2603 	skb->destructor = sock_ofree;
2604 	return skb;
2605 }
2606 
2607 /*
2608  * Allocate a memory block from the socket's option memory buffer.
2609  */
2610 void *sock_kmalloc(struct sock *sk, int size, gfp_t priority)
2611 {
2612 	int optmem_max = READ_ONCE(sysctl_optmem_max);
2613 
2614 	if ((unsigned int)size <= optmem_max &&
2615 	    atomic_read(&sk->sk_omem_alloc) + size < optmem_max) {
2616 		void *mem;
2617 		/* First do the add, to avoid the race if kmalloc
2618 		 * might sleep.
2619 		 */
2620 		atomic_add(size, &sk->sk_omem_alloc);
2621 		mem = kmalloc(size, priority);
2622 		if (mem)
2623 			return mem;
2624 		atomic_sub(size, &sk->sk_omem_alloc);
2625 	}
2626 	return NULL;
2627 }
2628 EXPORT_SYMBOL(sock_kmalloc);
2629 
2630 /* Free an option memory block. Note, we actually want the inline
2631  * here as this allows gcc to detect the nullify and fold away the
2632  * condition entirely.
2633  */
2634 static inline void __sock_kfree_s(struct sock *sk, void *mem, int size,
2635 				  const bool nullify)
2636 {
2637 	if (WARN_ON_ONCE(!mem))
2638 		return;
2639 	if (nullify)
2640 		kfree_sensitive(mem);
2641 	else
2642 		kfree(mem);
2643 	atomic_sub(size, &sk->sk_omem_alloc);
2644 }
2645 
2646 void sock_kfree_s(struct sock *sk, void *mem, int size)
2647 {
2648 	__sock_kfree_s(sk, mem, size, false);
2649 }
2650 EXPORT_SYMBOL(sock_kfree_s);
2651 
2652 void sock_kzfree_s(struct sock *sk, void *mem, int size)
2653 {
2654 	__sock_kfree_s(sk, mem, size, true);
2655 }
2656 EXPORT_SYMBOL(sock_kzfree_s);
2657 
2658 /* It is almost wait_for_tcp_memory minus release_sock/lock_sock.
2659    I think, these locks should be removed for datagram sockets.
2660  */
2661 static long sock_wait_for_wmem(struct sock *sk, long timeo)
2662 {
2663 	DEFINE_WAIT(wait);
2664 
2665 	sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
2666 	for (;;) {
2667 		if (!timeo)
2668 			break;
2669 		if (signal_pending(current))
2670 			break;
2671 		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
2672 		prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
2673 		if (refcount_read(&sk->sk_wmem_alloc) < READ_ONCE(sk->sk_sndbuf))
2674 			break;
2675 		if (sk->sk_shutdown & SEND_SHUTDOWN)
2676 			break;
2677 		if (sk->sk_err)
2678 			break;
2679 		timeo = schedule_timeout(timeo);
2680 	}
2681 	finish_wait(sk_sleep(sk), &wait);
2682 	return timeo;
2683 }
2684 
2685 
2686 /*
2687  *	Generic send/receive buffer handlers
2688  */
2689 
2690 struct sk_buff *sock_alloc_send_pskb(struct sock *sk, unsigned long header_len,
2691 				     unsigned long data_len, int noblock,
2692 				     int *errcode, int max_page_order)
2693 {
2694 	struct sk_buff *skb;
2695 	long timeo;
2696 	int err;
2697 
2698 	timeo = sock_sndtimeo(sk, noblock);
2699 	for (;;) {
2700 		err = sock_error(sk);
2701 		if (err != 0)
2702 			goto failure;
2703 
2704 		err = -EPIPE;
2705 		if (sk->sk_shutdown & SEND_SHUTDOWN)
2706 			goto failure;
2707 
2708 		if (sk_wmem_alloc_get(sk) < READ_ONCE(sk->sk_sndbuf))
2709 			break;
2710 
2711 		sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
2712 		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
2713 		err = -EAGAIN;
2714 		if (!timeo)
2715 			goto failure;
2716 		if (signal_pending(current))
2717 			goto interrupted;
2718 		timeo = sock_wait_for_wmem(sk, timeo);
2719 	}
2720 	skb = alloc_skb_with_frags(header_len, data_len, max_page_order,
2721 				   errcode, sk->sk_allocation);
2722 	if (skb)
2723 		skb_set_owner_w(skb, sk);
2724 	return skb;
2725 
2726 interrupted:
2727 	err = sock_intr_errno(timeo);
2728 failure:
2729 	*errcode = err;
2730 	return NULL;
2731 }
2732 EXPORT_SYMBOL(sock_alloc_send_pskb);
2733 
2734 int __sock_cmsg_send(struct sock *sk, struct msghdr *msg, struct cmsghdr *cmsg,
2735 		     struct sockcm_cookie *sockc)
2736 {
2737 	u32 tsflags;
2738 
2739 	switch (cmsg->cmsg_type) {
2740 	case SO_MARK:
2741 		if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_RAW) &&
2742 		    !ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
2743 			return -EPERM;
2744 		if (cmsg->cmsg_len != CMSG_LEN(sizeof(u32)))
2745 			return -EINVAL;
2746 		sockc->mark = *(u32 *)CMSG_DATA(cmsg);
2747 		break;
2748 	case SO_TIMESTAMPING_OLD:
2749 		if (cmsg->cmsg_len != CMSG_LEN(sizeof(u32)))
2750 			return -EINVAL;
2751 
2752 		tsflags = *(u32 *)CMSG_DATA(cmsg);
2753 		if (tsflags & ~SOF_TIMESTAMPING_TX_RECORD_MASK)
2754 			return -EINVAL;
2755 
2756 		sockc->tsflags &= ~SOF_TIMESTAMPING_TX_RECORD_MASK;
2757 		sockc->tsflags |= tsflags;
2758 		break;
2759 	case SCM_TXTIME:
2760 		if (!sock_flag(sk, SOCK_TXTIME))
2761 			return -EINVAL;
2762 		if (cmsg->cmsg_len != CMSG_LEN(sizeof(u64)))
2763 			return -EINVAL;
2764 		sockc->transmit_time = get_unaligned((u64 *)CMSG_DATA(cmsg));
2765 		break;
2766 	/* SCM_RIGHTS and SCM_CREDENTIALS are semantically in SOL_UNIX. */
2767 	case SCM_RIGHTS:
2768 	case SCM_CREDENTIALS:
2769 		break;
2770 	default:
2771 		return -EINVAL;
2772 	}
2773 	return 0;
2774 }
2775 EXPORT_SYMBOL(__sock_cmsg_send);
2776 
2777 int sock_cmsg_send(struct sock *sk, struct msghdr *msg,
2778 		   struct sockcm_cookie *sockc)
2779 {
2780 	struct cmsghdr *cmsg;
2781 	int ret;
2782 
2783 	for_each_cmsghdr(cmsg, msg) {
2784 		if (!CMSG_OK(msg, cmsg))
2785 			return -EINVAL;
2786 		if (cmsg->cmsg_level != SOL_SOCKET)
2787 			continue;
2788 		ret = __sock_cmsg_send(sk, msg, cmsg, sockc);
2789 		if (ret)
2790 			return ret;
2791 	}
2792 	return 0;
2793 }
2794 EXPORT_SYMBOL(sock_cmsg_send);
2795 
2796 static void sk_enter_memory_pressure(struct sock *sk)
2797 {
2798 	if (!sk->sk_prot->enter_memory_pressure)
2799 		return;
2800 
2801 	sk->sk_prot->enter_memory_pressure(sk);
2802 }
2803 
2804 static void sk_leave_memory_pressure(struct sock *sk)
2805 {
2806 	if (sk->sk_prot->leave_memory_pressure) {
2807 		sk->sk_prot->leave_memory_pressure(sk);
2808 	} else {
2809 		unsigned long *memory_pressure = sk->sk_prot->memory_pressure;
2810 
2811 		if (memory_pressure && READ_ONCE(*memory_pressure))
2812 			WRITE_ONCE(*memory_pressure, 0);
2813 	}
2814 }
2815 
2816 DEFINE_STATIC_KEY_FALSE(net_high_order_alloc_disable_key);
2817 
2818 /**
2819  * skb_page_frag_refill - check that a page_frag contains enough room
2820  * @sz: minimum size of the fragment we want to get
2821  * @pfrag: pointer to page_frag
2822  * @gfp: priority for memory allocation
2823  *
2824  * Note: While this allocator tries to use high order pages, there is
2825  * no guarantee that allocations succeed. Therefore, @sz MUST be
2826  * less or equal than PAGE_SIZE.
2827  */
2828 bool skb_page_frag_refill(unsigned int sz, struct page_frag *pfrag, gfp_t gfp)
2829 {
2830 	if (pfrag->page) {
2831 		if (page_ref_count(pfrag->page) == 1) {
2832 			pfrag->offset = 0;
2833 			return true;
2834 		}
2835 		if (pfrag->offset + sz <= pfrag->size)
2836 			return true;
2837 		put_page(pfrag->page);
2838 	}
2839 
2840 	pfrag->offset = 0;
2841 	if (SKB_FRAG_PAGE_ORDER &&
2842 	    !static_branch_unlikely(&net_high_order_alloc_disable_key)) {
2843 		/* Avoid direct reclaim but allow kswapd to wake */
2844 		pfrag->page = alloc_pages((gfp & ~__GFP_DIRECT_RECLAIM) |
2845 					  __GFP_COMP | __GFP_NOWARN |
2846 					  __GFP_NORETRY,
2847 					  SKB_FRAG_PAGE_ORDER);
2848 		if (likely(pfrag->page)) {
2849 			pfrag->size = PAGE_SIZE << SKB_FRAG_PAGE_ORDER;
2850 			return true;
2851 		}
2852 	}
2853 	pfrag->page = alloc_page(gfp);
2854 	if (likely(pfrag->page)) {
2855 		pfrag->size = PAGE_SIZE;
2856 		return true;
2857 	}
2858 	return false;
2859 }
2860 EXPORT_SYMBOL(skb_page_frag_refill);
2861 
2862 bool sk_page_frag_refill(struct sock *sk, struct page_frag *pfrag)
2863 {
2864 	if (likely(skb_page_frag_refill(32U, pfrag, sk->sk_allocation)))
2865 		return true;
2866 
2867 	sk_enter_memory_pressure(sk);
2868 	sk_stream_moderate_sndbuf(sk);
2869 	return false;
2870 }
2871 EXPORT_SYMBOL(sk_page_frag_refill);
2872 
2873 void __lock_sock(struct sock *sk)
2874 	__releases(&sk->sk_lock.slock)
2875 	__acquires(&sk->sk_lock.slock)
2876 {
2877 	DEFINE_WAIT(wait);
2878 
2879 	for (;;) {
2880 		prepare_to_wait_exclusive(&sk->sk_lock.wq, &wait,
2881 					TASK_UNINTERRUPTIBLE);
2882 		spin_unlock_bh(&sk->sk_lock.slock);
2883 		schedule();
2884 		spin_lock_bh(&sk->sk_lock.slock);
2885 		if (!sock_owned_by_user(sk))
2886 			break;
2887 	}
2888 	finish_wait(&sk->sk_lock.wq, &wait);
2889 }
2890 
2891 void __release_sock(struct sock *sk)
2892 	__releases(&sk->sk_lock.slock)
2893 	__acquires(&sk->sk_lock.slock)
2894 {
2895 	struct sk_buff *skb, *next;
2896 
2897 	while ((skb = sk->sk_backlog.head) != NULL) {
2898 		sk->sk_backlog.head = sk->sk_backlog.tail = NULL;
2899 
2900 		spin_unlock_bh(&sk->sk_lock.slock);
2901 
2902 		do {
2903 			next = skb->next;
2904 			prefetch(next);
2905 			DEBUG_NET_WARN_ON_ONCE(skb_dst_is_noref(skb));
2906 			skb_mark_not_on_list(skb);
2907 			sk_backlog_rcv(sk, skb);
2908 
2909 			cond_resched();
2910 
2911 			skb = next;
2912 		} while (skb != NULL);
2913 
2914 		spin_lock_bh(&sk->sk_lock.slock);
2915 	}
2916 
2917 	/*
2918 	 * Doing the zeroing here guarantee we can not loop forever
2919 	 * while a wild producer attempts to flood us.
2920 	 */
2921 	sk->sk_backlog.len = 0;
2922 }
2923 
2924 void __sk_flush_backlog(struct sock *sk)
2925 {
2926 	spin_lock_bh(&sk->sk_lock.slock);
2927 	__release_sock(sk);
2928 	spin_unlock_bh(&sk->sk_lock.slock);
2929 }
2930 EXPORT_SYMBOL_GPL(__sk_flush_backlog);
2931 
2932 /**
2933  * sk_wait_data - wait for data to arrive at sk_receive_queue
2934  * @sk:    sock to wait on
2935  * @timeo: for how long
2936  * @skb:   last skb seen on sk_receive_queue
2937  *
2938  * Now socket state including sk->sk_err is changed only under lock,
2939  * hence we may omit checks after joining wait queue.
2940  * We check receive queue before schedule() only as optimization;
2941  * it is very likely that release_sock() added new data.
2942  */
2943 int sk_wait_data(struct sock *sk, long *timeo, const struct sk_buff *skb)
2944 {
2945 	DEFINE_WAIT_FUNC(wait, woken_wake_function);
2946 	int rc;
2947 
2948 	add_wait_queue(sk_sleep(sk), &wait);
2949 	sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
2950 	rc = sk_wait_event(sk, timeo, skb_peek_tail(&sk->sk_receive_queue) != skb, &wait);
2951 	sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
2952 	remove_wait_queue(sk_sleep(sk), &wait);
2953 	return rc;
2954 }
2955 EXPORT_SYMBOL(sk_wait_data);
2956 
2957 /**
2958  *	__sk_mem_raise_allocated - increase memory_allocated
2959  *	@sk: socket
2960  *	@size: memory size to allocate
2961  *	@amt: pages to allocate
2962  *	@kind: allocation type
2963  *
2964  *	Similar to __sk_mem_schedule(), but does not update sk_forward_alloc
2965  */
2966 int __sk_mem_raise_allocated(struct sock *sk, int size, int amt, int kind)
2967 {
2968 	bool memcg_charge = mem_cgroup_sockets_enabled && sk->sk_memcg;
2969 	struct proto *prot = sk->sk_prot;
2970 	bool charged = true;
2971 	long allocated;
2972 
2973 	sk_memory_allocated_add(sk, amt);
2974 	allocated = sk_memory_allocated(sk);
2975 	if (memcg_charge &&
2976 	    !(charged = mem_cgroup_charge_skmem(sk->sk_memcg, amt,
2977 						gfp_memcg_charge())))
2978 		goto suppress_allocation;
2979 
2980 	/* Under limit. */
2981 	if (allocated <= sk_prot_mem_limits(sk, 0)) {
2982 		sk_leave_memory_pressure(sk);
2983 		return 1;
2984 	}
2985 
2986 	/* Under pressure. */
2987 	if (allocated > sk_prot_mem_limits(sk, 1))
2988 		sk_enter_memory_pressure(sk);
2989 
2990 	/* Over hard limit. */
2991 	if (allocated > sk_prot_mem_limits(sk, 2))
2992 		goto suppress_allocation;
2993 
2994 	/* guarantee minimum buffer size under pressure */
2995 	if (kind == SK_MEM_RECV) {
2996 		if (atomic_read(&sk->sk_rmem_alloc) < sk_get_rmem0(sk, prot))
2997 			return 1;
2998 
2999 	} else { /* SK_MEM_SEND */
3000 		int wmem0 = sk_get_wmem0(sk, prot);
3001 
3002 		if (sk->sk_type == SOCK_STREAM) {
3003 			if (sk->sk_wmem_queued < wmem0)
3004 				return 1;
3005 		} else if (refcount_read(&sk->sk_wmem_alloc) < wmem0) {
3006 				return 1;
3007 		}
3008 	}
3009 
3010 	if (sk_has_memory_pressure(sk)) {
3011 		u64 alloc;
3012 
3013 		if (!sk_under_memory_pressure(sk))
3014 			return 1;
3015 		alloc = sk_sockets_allocated_read_positive(sk);
3016 		if (sk_prot_mem_limits(sk, 2) > alloc *
3017 		    sk_mem_pages(sk->sk_wmem_queued +
3018 				 atomic_read(&sk->sk_rmem_alloc) +
3019 				 sk->sk_forward_alloc))
3020 			return 1;
3021 	}
3022 
3023 suppress_allocation:
3024 
3025 	if (kind == SK_MEM_SEND && sk->sk_type == SOCK_STREAM) {
3026 		sk_stream_moderate_sndbuf(sk);
3027 
3028 		/* Fail only if socket is _under_ its sndbuf.
3029 		 * In this case we cannot block, so that we have to fail.
3030 		 */
3031 		if (sk->sk_wmem_queued + size >= sk->sk_sndbuf) {
3032 			/* Force charge with __GFP_NOFAIL */
3033 			if (memcg_charge && !charged) {
3034 				mem_cgroup_charge_skmem(sk->sk_memcg, amt,
3035 					gfp_memcg_charge() | __GFP_NOFAIL);
3036 			}
3037 			return 1;
3038 		}
3039 	}
3040 
3041 	if (kind == SK_MEM_SEND || (kind == SK_MEM_RECV && charged))
3042 		trace_sock_exceed_buf_limit(sk, prot, allocated, kind);
3043 
3044 	sk_memory_allocated_sub(sk, amt);
3045 
3046 	if (memcg_charge && charged)
3047 		mem_cgroup_uncharge_skmem(sk->sk_memcg, amt);
3048 
3049 	return 0;
3050 }
3051 
3052 /**
3053  *	__sk_mem_schedule - increase sk_forward_alloc and memory_allocated
3054  *	@sk: socket
3055  *	@size: memory size to allocate
3056  *	@kind: allocation type
3057  *
3058  *	If kind is SK_MEM_SEND, it means wmem allocation. Otherwise it means
3059  *	rmem allocation. This function assumes that protocols which have
3060  *	memory_pressure use sk_wmem_queued as write buffer accounting.
3061  */
3062 int __sk_mem_schedule(struct sock *sk, int size, int kind)
3063 {
3064 	int ret, amt = sk_mem_pages(size);
3065 
3066 	sk->sk_forward_alloc += amt << PAGE_SHIFT;
3067 	ret = __sk_mem_raise_allocated(sk, size, amt, kind);
3068 	if (!ret)
3069 		sk->sk_forward_alloc -= amt << PAGE_SHIFT;
3070 	return ret;
3071 }
3072 EXPORT_SYMBOL(__sk_mem_schedule);
3073 
3074 /**
3075  *	__sk_mem_reduce_allocated - reclaim memory_allocated
3076  *	@sk: socket
3077  *	@amount: number of quanta
3078  *
3079  *	Similar to __sk_mem_reclaim(), but does not update sk_forward_alloc
3080  */
3081 void __sk_mem_reduce_allocated(struct sock *sk, int amount)
3082 {
3083 	sk_memory_allocated_sub(sk, amount);
3084 
3085 	if (mem_cgroup_sockets_enabled && sk->sk_memcg)
3086 		mem_cgroup_uncharge_skmem(sk->sk_memcg, amount);
3087 
3088 	if (sk_under_memory_pressure(sk) &&
3089 	    (sk_memory_allocated(sk) < sk_prot_mem_limits(sk, 0)))
3090 		sk_leave_memory_pressure(sk);
3091 }
3092 
3093 /**
3094  *	__sk_mem_reclaim - reclaim sk_forward_alloc and memory_allocated
3095  *	@sk: socket
3096  *	@amount: number of bytes (rounded down to a PAGE_SIZE multiple)
3097  */
3098 void __sk_mem_reclaim(struct sock *sk, int amount)
3099 {
3100 	amount >>= PAGE_SHIFT;
3101 	sk->sk_forward_alloc -= amount << PAGE_SHIFT;
3102 	__sk_mem_reduce_allocated(sk, amount);
3103 }
3104 EXPORT_SYMBOL(__sk_mem_reclaim);
3105 
3106 int sk_set_peek_off(struct sock *sk, int val)
3107 {
3108 	sk->sk_peek_off = val;
3109 	return 0;
3110 }
3111 EXPORT_SYMBOL_GPL(sk_set_peek_off);
3112 
3113 /*
3114  * Set of default routines for initialising struct proto_ops when
3115  * the protocol does not support a particular function. In certain
3116  * cases where it makes no sense for a protocol to have a "do nothing"
3117  * function, some default processing is provided.
3118  */
3119 
3120 int sock_no_bind(struct socket *sock, struct sockaddr *saddr, int len)
3121 {
3122 	return -EOPNOTSUPP;
3123 }
3124 EXPORT_SYMBOL(sock_no_bind);
3125 
3126 int sock_no_connect(struct socket *sock, struct sockaddr *saddr,
3127 		    int len, int flags)
3128 {
3129 	return -EOPNOTSUPP;
3130 }
3131 EXPORT_SYMBOL(sock_no_connect);
3132 
3133 int sock_no_socketpair(struct socket *sock1, struct socket *sock2)
3134 {
3135 	return -EOPNOTSUPP;
3136 }
3137 EXPORT_SYMBOL(sock_no_socketpair);
3138 
3139 int sock_no_accept(struct socket *sock, struct socket *newsock, int flags,
3140 		   bool kern)
3141 {
3142 	return -EOPNOTSUPP;
3143 }
3144 EXPORT_SYMBOL(sock_no_accept);
3145 
3146 int sock_no_getname(struct socket *sock, struct sockaddr *saddr,
3147 		    int peer)
3148 {
3149 	return -EOPNOTSUPP;
3150 }
3151 EXPORT_SYMBOL(sock_no_getname);
3152 
3153 int sock_no_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
3154 {
3155 	return -EOPNOTSUPP;
3156 }
3157 EXPORT_SYMBOL(sock_no_ioctl);
3158 
3159 int sock_no_listen(struct socket *sock, int backlog)
3160 {
3161 	return -EOPNOTSUPP;
3162 }
3163 EXPORT_SYMBOL(sock_no_listen);
3164 
3165 int sock_no_shutdown(struct socket *sock, int how)
3166 {
3167 	return -EOPNOTSUPP;
3168 }
3169 EXPORT_SYMBOL(sock_no_shutdown);
3170 
3171 int sock_no_sendmsg(struct socket *sock, struct msghdr *m, size_t len)
3172 {
3173 	return -EOPNOTSUPP;
3174 }
3175 EXPORT_SYMBOL(sock_no_sendmsg);
3176 
3177 int sock_no_sendmsg_locked(struct sock *sk, struct msghdr *m, size_t len)
3178 {
3179 	return -EOPNOTSUPP;
3180 }
3181 EXPORT_SYMBOL(sock_no_sendmsg_locked);
3182 
3183 int sock_no_recvmsg(struct socket *sock, struct msghdr *m, size_t len,
3184 		    int flags)
3185 {
3186 	return -EOPNOTSUPP;
3187 }
3188 EXPORT_SYMBOL(sock_no_recvmsg);
3189 
3190 int sock_no_mmap(struct file *file, struct socket *sock, struct vm_area_struct *vma)
3191 {
3192 	/* Mirror missing mmap method error code */
3193 	return -ENODEV;
3194 }
3195 EXPORT_SYMBOL(sock_no_mmap);
3196 
3197 /*
3198  * When a file is received (via SCM_RIGHTS, etc), we must bump the
3199  * various sock-based usage counts.
3200  */
3201 void __receive_sock(struct file *file)
3202 {
3203 	struct socket *sock;
3204 
3205 	sock = sock_from_file(file);
3206 	if (sock) {
3207 		sock_update_netprioidx(&sock->sk->sk_cgrp_data);
3208 		sock_update_classid(&sock->sk->sk_cgrp_data);
3209 	}
3210 }
3211 
3212 ssize_t sock_no_sendpage(struct socket *sock, struct page *page, int offset, size_t size, int flags)
3213 {
3214 	ssize_t res;
3215 	struct msghdr msg = {.msg_flags = flags};
3216 	struct kvec iov;
3217 	char *kaddr = kmap(page);
3218 	iov.iov_base = kaddr + offset;
3219 	iov.iov_len = size;
3220 	res = kernel_sendmsg(sock, &msg, &iov, 1, size);
3221 	kunmap(page);
3222 	return res;
3223 }
3224 EXPORT_SYMBOL(sock_no_sendpage);
3225 
3226 ssize_t sock_no_sendpage_locked(struct sock *sk, struct page *page,
3227 				int offset, size_t size, int flags)
3228 {
3229 	ssize_t res;
3230 	struct msghdr msg = {.msg_flags = flags};
3231 	struct kvec iov;
3232 	char *kaddr = kmap(page);
3233 
3234 	iov.iov_base = kaddr + offset;
3235 	iov.iov_len = size;
3236 	res = kernel_sendmsg_locked(sk, &msg, &iov, 1, size);
3237 	kunmap(page);
3238 	return res;
3239 }
3240 EXPORT_SYMBOL(sock_no_sendpage_locked);
3241 
3242 /*
3243  *	Default Socket Callbacks
3244  */
3245 
3246 static void sock_def_wakeup(struct sock *sk)
3247 {
3248 	struct socket_wq *wq;
3249 
3250 	rcu_read_lock();
3251 	wq = rcu_dereference(sk->sk_wq);
3252 	if (skwq_has_sleeper(wq))
3253 		wake_up_interruptible_all(&wq->wait);
3254 	rcu_read_unlock();
3255 }
3256 
3257 static void sock_def_error_report(struct sock *sk)
3258 {
3259 	struct socket_wq *wq;
3260 
3261 	rcu_read_lock();
3262 	wq = rcu_dereference(sk->sk_wq);
3263 	if (skwq_has_sleeper(wq))
3264 		wake_up_interruptible_poll(&wq->wait, EPOLLERR);
3265 	sk_wake_async(sk, SOCK_WAKE_IO, POLL_ERR);
3266 	rcu_read_unlock();
3267 }
3268 
3269 void sock_def_readable(struct sock *sk)
3270 {
3271 	struct socket_wq *wq;
3272 
3273 	rcu_read_lock();
3274 	wq = rcu_dereference(sk->sk_wq);
3275 	if (skwq_has_sleeper(wq))
3276 		wake_up_interruptible_sync_poll(&wq->wait, EPOLLIN | EPOLLPRI |
3277 						EPOLLRDNORM | EPOLLRDBAND);
3278 	sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
3279 	rcu_read_unlock();
3280 }
3281 
3282 static void sock_def_write_space(struct sock *sk)
3283 {
3284 	struct socket_wq *wq;
3285 
3286 	rcu_read_lock();
3287 
3288 	/* Do not wake up a writer until he can make "significant"
3289 	 * progress.  --DaveM
3290 	 */
3291 	if (sock_writeable(sk)) {
3292 		wq = rcu_dereference(sk->sk_wq);
3293 		if (skwq_has_sleeper(wq))
3294 			wake_up_interruptible_sync_poll(&wq->wait, EPOLLOUT |
3295 						EPOLLWRNORM | EPOLLWRBAND);
3296 
3297 		/* Should agree with poll, otherwise some programs break */
3298 		sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
3299 	}
3300 
3301 	rcu_read_unlock();
3302 }
3303 
3304 /* An optimised version of sock_def_write_space(), should only be called
3305  * for SOCK_RCU_FREE sockets under RCU read section and after putting
3306  * ->sk_wmem_alloc.
3307  */
3308 static void sock_def_write_space_wfree(struct sock *sk)
3309 {
3310 	/* Do not wake up a writer until he can make "significant"
3311 	 * progress.  --DaveM
3312 	 */
3313 	if (sock_writeable(sk)) {
3314 		struct socket_wq *wq = rcu_dereference(sk->sk_wq);
3315 
3316 		/* rely on refcount_sub from sock_wfree() */
3317 		smp_mb__after_atomic();
3318 		if (wq && waitqueue_active(&wq->wait))
3319 			wake_up_interruptible_sync_poll(&wq->wait, EPOLLOUT |
3320 						EPOLLWRNORM | EPOLLWRBAND);
3321 
3322 		/* Should agree with poll, otherwise some programs break */
3323 		sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
3324 	}
3325 }
3326 
3327 static void sock_def_destruct(struct sock *sk)
3328 {
3329 }
3330 
3331 void sk_send_sigurg(struct sock *sk)
3332 {
3333 	if (sk->sk_socket && sk->sk_socket->file)
3334 		if (send_sigurg(&sk->sk_socket->file->f_owner))
3335 			sk_wake_async(sk, SOCK_WAKE_URG, POLL_PRI);
3336 }
3337 EXPORT_SYMBOL(sk_send_sigurg);
3338 
3339 void sk_reset_timer(struct sock *sk, struct timer_list* timer,
3340 		    unsigned long expires)
3341 {
3342 	if (!mod_timer(timer, expires))
3343 		sock_hold(sk);
3344 }
3345 EXPORT_SYMBOL(sk_reset_timer);
3346 
3347 void sk_stop_timer(struct sock *sk, struct timer_list* timer)
3348 {
3349 	if (del_timer(timer))
3350 		__sock_put(sk);
3351 }
3352 EXPORT_SYMBOL(sk_stop_timer);
3353 
3354 void sk_stop_timer_sync(struct sock *sk, struct timer_list *timer)
3355 {
3356 	if (del_timer_sync(timer))
3357 		__sock_put(sk);
3358 }
3359 EXPORT_SYMBOL(sk_stop_timer_sync);
3360 
3361 void sock_init_data(struct socket *sock, struct sock *sk)
3362 {
3363 	sk_init_common(sk);
3364 	sk->sk_send_head	=	NULL;
3365 
3366 	timer_setup(&sk->sk_timer, NULL, 0);
3367 
3368 	sk->sk_allocation	=	GFP_KERNEL;
3369 	sk->sk_rcvbuf		=	READ_ONCE(sysctl_rmem_default);
3370 	sk->sk_sndbuf		=	READ_ONCE(sysctl_wmem_default);
3371 	sk->sk_state		=	TCP_CLOSE;
3372 	sk_set_socket(sk, sock);
3373 
3374 	sock_set_flag(sk, SOCK_ZAPPED);
3375 
3376 	if (sock) {
3377 		sk->sk_type	=	sock->type;
3378 		RCU_INIT_POINTER(sk->sk_wq, &sock->wq);
3379 		sock->sk	=	sk;
3380 		sk->sk_uid	=	SOCK_INODE(sock)->i_uid;
3381 	} else {
3382 		RCU_INIT_POINTER(sk->sk_wq, NULL);
3383 		sk->sk_uid	=	make_kuid(sock_net(sk)->user_ns, 0);
3384 	}
3385 
3386 	rwlock_init(&sk->sk_callback_lock);
3387 	if (sk->sk_kern_sock)
3388 		lockdep_set_class_and_name(
3389 			&sk->sk_callback_lock,
3390 			af_kern_callback_keys + sk->sk_family,
3391 			af_family_kern_clock_key_strings[sk->sk_family]);
3392 	else
3393 		lockdep_set_class_and_name(
3394 			&sk->sk_callback_lock,
3395 			af_callback_keys + sk->sk_family,
3396 			af_family_clock_key_strings[sk->sk_family]);
3397 
3398 	sk->sk_state_change	=	sock_def_wakeup;
3399 	sk->sk_data_ready	=	sock_def_readable;
3400 	sk->sk_write_space	=	sock_def_write_space;
3401 	sk->sk_error_report	=	sock_def_error_report;
3402 	sk->sk_destruct		=	sock_def_destruct;
3403 
3404 	sk->sk_frag.page	=	NULL;
3405 	sk->sk_frag.offset	=	0;
3406 	sk->sk_peek_off		=	-1;
3407 
3408 	sk->sk_peer_pid 	=	NULL;
3409 	sk->sk_peer_cred	=	NULL;
3410 	spin_lock_init(&sk->sk_peer_lock);
3411 
3412 	sk->sk_write_pending	=	0;
3413 	sk->sk_rcvlowat		=	1;
3414 	sk->sk_rcvtimeo		=	MAX_SCHEDULE_TIMEOUT;
3415 	sk->sk_sndtimeo		=	MAX_SCHEDULE_TIMEOUT;
3416 
3417 	sk->sk_stamp = SK_DEFAULT_STAMP;
3418 #if BITS_PER_LONG==32
3419 	seqlock_init(&sk->sk_stamp_seq);
3420 #endif
3421 	atomic_set(&sk->sk_zckey, 0);
3422 
3423 #ifdef CONFIG_NET_RX_BUSY_POLL
3424 	sk->sk_napi_id		=	0;
3425 	sk->sk_ll_usec		=	READ_ONCE(sysctl_net_busy_read);
3426 #endif
3427 
3428 	sk->sk_max_pacing_rate = ~0UL;
3429 	sk->sk_pacing_rate = ~0UL;
3430 	WRITE_ONCE(sk->sk_pacing_shift, 10);
3431 	sk->sk_incoming_cpu = -1;
3432 	sk->sk_txrehash = SOCK_TXREHASH_DEFAULT;
3433 
3434 	sk_rx_queue_clear(sk);
3435 	/*
3436 	 * Before updating sk_refcnt, we must commit prior changes to memory
3437 	 * (Documentation/RCU/rculist_nulls.rst for details)
3438 	 */
3439 	smp_wmb();
3440 	refcount_set(&sk->sk_refcnt, 1);
3441 	atomic_set(&sk->sk_drops, 0);
3442 }
3443 EXPORT_SYMBOL(sock_init_data);
3444 
3445 void lock_sock_nested(struct sock *sk, int subclass)
3446 {
3447 	/* The sk_lock has mutex_lock() semantics here. */
3448 	mutex_acquire(&sk->sk_lock.dep_map, subclass, 0, _RET_IP_);
3449 
3450 	might_sleep();
3451 	spin_lock_bh(&sk->sk_lock.slock);
3452 	if (sock_owned_by_user_nocheck(sk))
3453 		__lock_sock(sk);
3454 	sk->sk_lock.owned = 1;
3455 	spin_unlock_bh(&sk->sk_lock.slock);
3456 }
3457 EXPORT_SYMBOL(lock_sock_nested);
3458 
3459 void release_sock(struct sock *sk)
3460 {
3461 	spin_lock_bh(&sk->sk_lock.slock);
3462 	if (sk->sk_backlog.tail)
3463 		__release_sock(sk);
3464 
3465 	/* Warning : release_cb() might need to release sk ownership,
3466 	 * ie call sock_release_ownership(sk) before us.
3467 	 */
3468 	if (sk->sk_prot->release_cb)
3469 		sk->sk_prot->release_cb(sk);
3470 
3471 	sock_release_ownership(sk);
3472 	if (waitqueue_active(&sk->sk_lock.wq))
3473 		wake_up(&sk->sk_lock.wq);
3474 	spin_unlock_bh(&sk->sk_lock.slock);
3475 }
3476 EXPORT_SYMBOL(release_sock);
3477 
3478 bool __lock_sock_fast(struct sock *sk) __acquires(&sk->sk_lock.slock)
3479 {
3480 	might_sleep();
3481 	spin_lock_bh(&sk->sk_lock.slock);
3482 
3483 	if (!sock_owned_by_user_nocheck(sk)) {
3484 		/*
3485 		 * Fast path return with bottom halves disabled and
3486 		 * sock::sk_lock.slock held.
3487 		 *
3488 		 * The 'mutex' is not contended and holding
3489 		 * sock::sk_lock.slock prevents all other lockers to
3490 		 * proceed so the corresponding unlock_sock_fast() can
3491 		 * avoid the slow path of release_sock() completely and
3492 		 * just release slock.
3493 		 *
3494 		 * From a semantical POV this is equivalent to 'acquiring'
3495 		 * the 'mutex', hence the corresponding lockdep
3496 		 * mutex_release() has to happen in the fast path of
3497 		 * unlock_sock_fast().
3498 		 */
3499 		return false;
3500 	}
3501 
3502 	__lock_sock(sk);
3503 	sk->sk_lock.owned = 1;
3504 	__acquire(&sk->sk_lock.slock);
3505 	spin_unlock_bh(&sk->sk_lock.slock);
3506 	return true;
3507 }
3508 EXPORT_SYMBOL(__lock_sock_fast);
3509 
3510 int sock_gettstamp(struct socket *sock, void __user *userstamp,
3511 		   bool timeval, bool time32)
3512 {
3513 	struct sock *sk = sock->sk;
3514 	struct timespec64 ts;
3515 
3516 	sock_enable_timestamp(sk, SOCK_TIMESTAMP);
3517 	ts = ktime_to_timespec64(sock_read_timestamp(sk));
3518 	if (ts.tv_sec == -1)
3519 		return -ENOENT;
3520 	if (ts.tv_sec == 0) {
3521 		ktime_t kt = ktime_get_real();
3522 		sock_write_timestamp(sk, kt);
3523 		ts = ktime_to_timespec64(kt);
3524 	}
3525 
3526 	if (timeval)
3527 		ts.tv_nsec /= 1000;
3528 
3529 #ifdef CONFIG_COMPAT_32BIT_TIME
3530 	if (time32)
3531 		return put_old_timespec32(&ts, userstamp);
3532 #endif
3533 #ifdef CONFIG_SPARC64
3534 	/* beware of padding in sparc64 timeval */
3535 	if (timeval && !in_compat_syscall()) {
3536 		struct __kernel_old_timeval __user tv = {
3537 			.tv_sec = ts.tv_sec,
3538 			.tv_usec = ts.tv_nsec,
3539 		};
3540 		if (copy_to_user(userstamp, &tv, sizeof(tv)))
3541 			return -EFAULT;
3542 		return 0;
3543 	}
3544 #endif
3545 	return put_timespec64(&ts, userstamp);
3546 }
3547 EXPORT_SYMBOL(sock_gettstamp);
3548 
3549 void sock_enable_timestamp(struct sock *sk, enum sock_flags flag)
3550 {
3551 	if (!sock_flag(sk, flag)) {
3552 		unsigned long previous_flags = sk->sk_flags;
3553 
3554 		sock_set_flag(sk, flag);
3555 		/*
3556 		 * we just set one of the two flags which require net
3557 		 * time stamping, but time stamping might have been on
3558 		 * already because of the other one
3559 		 */
3560 		if (sock_needs_netstamp(sk) &&
3561 		    !(previous_flags & SK_FLAGS_TIMESTAMP))
3562 			net_enable_timestamp();
3563 	}
3564 }
3565 
3566 int sock_recv_errqueue(struct sock *sk, struct msghdr *msg, int len,
3567 		       int level, int type)
3568 {
3569 	struct sock_exterr_skb *serr;
3570 	struct sk_buff *skb;
3571 	int copied, err;
3572 
3573 	err = -EAGAIN;
3574 	skb = sock_dequeue_err_skb(sk);
3575 	if (skb == NULL)
3576 		goto out;
3577 
3578 	copied = skb->len;
3579 	if (copied > len) {
3580 		msg->msg_flags |= MSG_TRUNC;
3581 		copied = len;
3582 	}
3583 	err = skb_copy_datagram_msg(skb, 0, msg, copied);
3584 	if (err)
3585 		goto out_free_skb;
3586 
3587 	sock_recv_timestamp(msg, sk, skb);
3588 
3589 	serr = SKB_EXT_ERR(skb);
3590 	put_cmsg(msg, level, type, sizeof(serr->ee), &serr->ee);
3591 
3592 	msg->msg_flags |= MSG_ERRQUEUE;
3593 	err = copied;
3594 
3595 out_free_skb:
3596 	kfree_skb(skb);
3597 out:
3598 	return err;
3599 }
3600 EXPORT_SYMBOL(sock_recv_errqueue);
3601 
3602 /*
3603  *	Get a socket option on an socket.
3604  *
3605  *	FIX: POSIX 1003.1g is very ambiguous here. It states that
3606  *	asynchronous errors should be reported by getsockopt. We assume
3607  *	this means if you specify SO_ERROR (otherwise whats the point of it).
3608  */
3609 int sock_common_getsockopt(struct socket *sock, int level, int optname,
3610 			   char __user *optval, int __user *optlen)
3611 {
3612 	struct sock *sk = sock->sk;
3613 
3614 	/* IPV6_ADDRFORM can change sk->sk_prot under us. */
3615 	return READ_ONCE(sk->sk_prot)->getsockopt(sk, level, optname, optval, optlen);
3616 }
3617 EXPORT_SYMBOL(sock_common_getsockopt);
3618 
3619 int sock_common_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
3620 			int flags)
3621 {
3622 	struct sock *sk = sock->sk;
3623 	int addr_len = 0;
3624 	int err;
3625 
3626 	err = sk->sk_prot->recvmsg(sk, msg, size, flags, &addr_len);
3627 	if (err >= 0)
3628 		msg->msg_namelen = addr_len;
3629 	return err;
3630 }
3631 EXPORT_SYMBOL(sock_common_recvmsg);
3632 
3633 /*
3634  *	Set socket options on an inet socket.
3635  */
3636 int sock_common_setsockopt(struct socket *sock, int level, int optname,
3637 			   sockptr_t optval, unsigned int optlen)
3638 {
3639 	struct sock *sk = sock->sk;
3640 
3641 	/* IPV6_ADDRFORM can change sk->sk_prot under us. */
3642 	return READ_ONCE(sk->sk_prot)->setsockopt(sk, level, optname, optval, optlen);
3643 }
3644 EXPORT_SYMBOL(sock_common_setsockopt);
3645 
3646 void sk_common_release(struct sock *sk)
3647 {
3648 	if (sk->sk_prot->destroy)
3649 		sk->sk_prot->destroy(sk);
3650 
3651 	/*
3652 	 * Observation: when sk_common_release is called, processes have
3653 	 * no access to socket. But net still has.
3654 	 * Step one, detach it from networking:
3655 	 *
3656 	 * A. Remove from hash tables.
3657 	 */
3658 
3659 	sk->sk_prot->unhash(sk);
3660 
3661 	/*
3662 	 * In this point socket cannot receive new packets, but it is possible
3663 	 * that some packets are in flight because some CPU runs receiver and
3664 	 * did hash table lookup before we unhashed socket. They will achieve
3665 	 * receive queue and will be purged by socket destructor.
3666 	 *
3667 	 * Also we still have packets pending on receive queue and probably,
3668 	 * our own packets waiting in device queues. sock_destroy will drain
3669 	 * receive queue, but transmitted packets will delay socket destruction
3670 	 * until the last reference will be released.
3671 	 */
3672 
3673 	sock_orphan(sk);
3674 
3675 	xfrm_sk_free_policy(sk);
3676 
3677 	sk_refcnt_debug_release(sk);
3678 
3679 	sock_put(sk);
3680 }
3681 EXPORT_SYMBOL(sk_common_release);
3682 
3683 void sk_get_meminfo(const struct sock *sk, u32 *mem)
3684 {
3685 	memset(mem, 0, sizeof(*mem) * SK_MEMINFO_VARS);
3686 
3687 	mem[SK_MEMINFO_RMEM_ALLOC] = sk_rmem_alloc_get(sk);
3688 	mem[SK_MEMINFO_RCVBUF] = READ_ONCE(sk->sk_rcvbuf);
3689 	mem[SK_MEMINFO_WMEM_ALLOC] = sk_wmem_alloc_get(sk);
3690 	mem[SK_MEMINFO_SNDBUF] = READ_ONCE(sk->sk_sndbuf);
3691 	mem[SK_MEMINFO_FWD_ALLOC] = sk->sk_forward_alloc;
3692 	mem[SK_MEMINFO_WMEM_QUEUED] = READ_ONCE(sk->sk_wmem_queued);
3693 	mem[SK_MEMINFO_OPTMEM] = atomic_read(&sk->sk_omem_alloc);
3694 	mem[SK_MEMINFO_BACKLOG] = READ_ONCE(sk->sk_backlog.len);
3695 	mem[SK_MEMINFO_DROPS] = atomic_read(&sk->sk_drops);
3696 }
3697 
3698 #ifdef CONFIG_PROC_FS
3699 static DECLARE_BITMAP(proto_inuse_idx, PROTO_INUSE_NR);
3700 
3701 int sock_prot_inuse_get(struct net *net, struct proto *prot)
3702 {
3703 	int cpu, idx = prot->inuse_idx;
3704 	int res = 0;
3705 
3706 	for_each_possible_cpu(cpu)
3707 		res += per_cpu_ptr(net->core.prot_inuse, cpu)->val[idx];
3708 
3709 	return res >= 0 ? res : 0;
3710 }
3711 EXPORT_SYMBOL_GPL(sock_prot_inuse_get);
3712 
3713 int sock_inuse_get(struct net *net)
3714 {
3715 	int cpu, res = 0;
3716 
3717 	for_each_possible_cpu(cpu)
3718 		res += per_cpu_ptr(net->core.prot_inuse, cpu)->all;
3719 
3720 	return res;
3721 }
3722 
3723 EXPORT_SYMBOL_GPL(sock_inuse_get);
3724 
3725 static int __net_init sock_inuse_init_net(struct net *net)
3726 {
3727 	net->core.prot_inuse = alloc_percpu(struct prot_inuse);
3728 	if (net->core.prot_inuse == NULL)
3729 		return -ENOMEM;
3730 	return 0;
3731 }
3732 
3733 static void __net_exit sock_inuse_exit_net(struct net *net)
3734 {
3735 	free_percpu(net->core.prot_inuse);
3736 }
3737 
3738 static struct pernet_operations net_inuse_ops = {
3739 	.init = sock_inuse_init_net,
3740 	.exit = sock_inuse_exit_net,
3741 };
3742 
3743 static __init int net_inuse_init(void)
3744 {
3745 	if (register_pernet_subsys(&net_inuse_ops))
3746 		panic("Cannot initialize net inuse counters");
3747 
3748 	return 0;
3749 }
3750 
3751 core_initcall(net_inuse_init);
3752 
3753 static int assign_proto_idx(struct proto *prot)
3754 {
3755 	prot->inuse_idx = find_first_zero_bit(proto_inuse_idx, PROTO_INUSE_NR);
3756 
3757 	if (unlikely(prot->inuse_idx == PROTO_INUSE_NR - 1)) {
3758 		pr_err("PROTO_INUSE_NR exhausted\n");
3759 		return -ENOSPC;
3760 	}
3761 
3762 	set_bit(prot->inuse_idx, proto_inuse_idx);
3763 	return 0;
3764 }
3765 
3766 static void release_proto_idx(struct proto *prot)
3767 {
3768 	if (prot->inuse_idx != PROTO_INUSE_NR - 1)
3769 		clear_bit(prot->inuse_idx, proto_inuse_idx);
3770 }
3771 #else
3772 static inline int assign_proto_idx(struct proto *prot)
3773 {
3774 	return 0;
3775 }
3776 
3777 static inline void release_proto_idx(struct proto *prot)
3778 {
3779 }
3780 
3781 #endif
3782 
3783 static void tw_prot_cleanup(struct timewait_sock_ops *twsk_prot)
3784 {
3785 	if (!twsk_prot)
3786 		return;
3787 	kfree(twsk_prot->twsk_slab_name);
3788 	twsk_prot->twsk_slab_name = NULL;
3789 	kmem_cache_destroy(twsk_prot->twsk_slab);
3790 	twsk_prot->twsk_slab = NULL;
3791 }
3792 
3793 static int tw_prot_init(const struct proto *prot)
3794 {
3795 	struct timewait_sock_ops *twsk_prot = prot->twsk_prot;
3796 
3797 	if (!twsk_prot)
3798 		return 0;
3799 
3800 	twsk_prot->twsk_slab_name = kasprintf(GFP_KERNEL, "tw_sock_%s",
3801 					      prot->name);
3802 	if (!twsk_prot->twsk_slab_name)
3803 		return -ENOMEM;
3804 
3805 	twsk_prot->twsk_slab =
3806 		kmem_cache_create(twsk_prot->twsk_slab_name,
3807 				  twsk_prot->twsk_obj_size, 0,
3808 				  SLAB_ACCOUNT | prot->slab_flags,
3809 				  NULL);
3810 	if (!twsk_prot->twsk_slab) {
3811 		pr_crit("%s: Can't create timewait sock SLAB cache!\n",
3812 			prot->name);
3813 		return -ENOMEM;
3814 	}
3815 
3816 	return 0;
3817 }
3818 
3819 static void req_prot_cleanup(struct request_sock_ops *rsk_prot)
3820 {
3821 	if (!rsk_prot)
3822 		return;
3823 	kfree(rsk_prot->slab_name);
3824 	rsk_prot->slab_name = NULL;
3825 	kmem_cache_destroy(rsk_prot->slab);
3826 	rsk_prot->slab = NULL;
3827 }
3828 
3829 static int req_prot_init(const struct proto *prot)
3830 {
3831 	struct request_sock_ops *rsk_prot = prot->rsk_prot;
3832 
3833 	if (!rsk_prot)
3834 		return 0;
3835 
3836 	rsk_prot->slab_name = kasprintf(GFP_KERNEL, "request_sock_%s",
3837 					prot->name);
3838 	if (!rsk_prot->slab_name)
3839 		return -ENOMEM;
3840 
3841 	rsk_prot->slab = kmem_cache_create(rsk_prot->slab_name,
3842 					   rsk_prot->obj_size, 0,
3843 					   SLAB_ACCOUNT | prot->slab_flags,
3844 					   NULL);
3845 
3846 	if (!rsk_prot->slab) {
3847 		pr_crit("%s: Can't create request sock SLAB cache!\n",
3848 			prot->name);
3849 		return -ENOMEM;
3850 	}
3851 	return 0;
3852 }
3853 
3854 int proto_register(struct proto *prot, int alloc_slab)
3855 {
3856 	int ret = -ENOBUFS;
3857 
3858 	if (prot->memory_allocated && !prot->sysctl_mem) {
3859 		pr_err("%s: missing sysctl_mem\n", prot->name);
3860 		return -EINVAL;
3861 	}
3862 	if (prot->memory_allocated && !prot->per_cpu_fw_alloc) {
3863 		pr_err("%s: missing per_cpu_fw_alloc\n", prot->name);
3864 		return -EINVAL;
3865 	}
3866 	if (alloc_slab) {
3867 		prot->slab = kmem_cache_create_usercopy(prot->name,
3868 					prot->obj_size, 0,
3869 					SLAB_HWCACHE_ALIGN | SLAB_ACCOUNT |
3870 					prot->slab_flags,
3871 					prot->useroffset, prot->usersize,
3872 					NULL);
3873 
3874 		if (prot->slab == NULL) {
3875 			pr_crit("%s: Can't create sock SLAB cache!\n",
3876 				prot->name);
3877 			goto out;
3878 		}
3879 
3880 		if (req_prot_init(prot))
3881 			goto out_free_request_sock_slab;
3882 
3883 		if (tw_prot_init(prot))
3884 			goto out_free_timewait_sock_slab;
3885 	}
3886 
3887 	mutex_lock(&proto_list_mutex);
3888 	ret = assign_proto_idx(prot);
3889 	if (ret) {
3890 		mutex_unlock(&proto_list_mutex);
3891 		goto out_free_timewait_sock_slab;
3892 	}
3893 	list_add(&prot->node, &proto_list);
3894 	mutex_unlock(&proto_list_mutex);
3895 	return ret;
3896 
3897 out_free_timewait_sock_slab:
3898 	if (alloc_slab)
3899 		tw_prot_cleanup(prot->twsk_prot);
3900 out_free_request_sock_slab:
3901 	if (alloc_slab) {
3902 		req_prot_cleanup(prot->rsk_prot);
3903 
3904 		kmem_cache_destroy(prot->slab);
3905 		prot->slab = NULL;
3906 	}
3907 out:
3908 	return ret;
3909 }
3910 EXPORT_SYMBOL(proto_register);
3911 
3912 void proto_unregister(struct proto *prot)
3913 {
3914 	mutex_lock(&proto_list_mutex);
3915 	release_proto_idx(prot);
3916 	list_del(&prot->node);
3917 	mutex_unlock(&proto_list_mutex);
3918 
3919 	kmem_cache_destroy(prot->slab);
3920 	prot->slab = NULL;
3921 
3922 	req_prot_cleanup(prot->rsk_prot);
3923 	tw_prot_cleanup(prot->twsk_prot);
3924 }
3925 EXPORT_SYMBOL(proto_unregister);
3926 
3927 int sock_load_diag_module(int family, int protocol)
3928 {
3929 	if (!protocol) {
3930 		if (!sock_is_registered(family))
3931 			return -ENOENT;
3932 
3933 		return request_module("net-pf-%d-proto-%d-type-%d", PF_NETLINK,
3934 				      NETLINK_SOCK_DIAG, family);
3935 	}
3936 
3937 #ifdef CONFIG_INET
3938 	if (family == AF_INET &&
3939 	    protocol != IPPROTO_RAW &&
3940 	    protocol < MAX_INET_PROTOS &&
3941 	    !rcu_access_pointer(inet_protos[protocol]))
3942 		return -ENOENT;
3943 #endif
3944 
3945 	return request_module("net-pf-%d-proto-%d-type-%d-%d", PF_NETLINK,
3946 			      NETLINK_SOCK_DIAG, family, protocol);
3947 }
3948 EXPORT_SYMBOL(sock_load_diag_module);
3949 
3950 #ifdef CONFIG_PROC_FS
3951 static void *proto_seq_start(struct seq_file *seq, loff_t *pos)
3952 	__acquires(proto_list_mutex)
3953 {
3954 	mutex_lock(&proto_list_mutex);
3955 	return seq_list_start_head(&proto_list, *pos);
3956 }
3957 
3958 static void *proto_seq_next(struct seq_file *seq, void *v, loff_t *pos)
3959 {
3960 	return seq_list_next(v, &proto_list, pos);
3961 }
3962 
3963 static void proto_seq_stop(struct seq_file *seq, void *v)
3964 	__releases(proto_list_mutex)
3965 {
3966 	mutex_unlock(&proto_list_mutex);
3967 }
3968 
3969 static char proto_method_implemented(const void *method)
3970 {
3971 	return method == NULL ? 'n' : 'y';
3972 }
3973 static long sock_prot_memory_allocated(struct proto *proto)
3974 {
3975 	return proto->memory_allocated != NULL ? proto_memory_allocated(proto) : -1L;
3976 }
3977 
3978 static const char *sock_prot_memory_pressure(struct proto *proto)
3979 {
3980 	return proto->memory_pressure != NULL ?
3981 	proto_memory_pressure(proto) ? "yes" : "no" : "NI";
3982 }
3983 
3984 static void proto_seq_printf(struct seq_file *seq, struct proto *proto)
3985 {
3986 
3987 	seq_printf(seq, "%-9s %4u %6d  %6ld   %-3s %6u   %-3s  %-10s "
3988 			"%2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c\n",
3989 		   proto->name,
3990 		   proto->obj_size,
3991 		   sock_prot_inuse_get(seq_file_net(seq), proto),
3992 		   sock_prot_memory_allocated(proto),
3993 		   sock_prot_memory_pressure(proto),
3994 		   proto->max_header,
3995 		   proto->slab == NULL ? "no" : "yes",
3996 		   module_name(proto->owner),
3997 		   proto_method_implemented(proto->close),
3998 		   proto_method_implemented(proto->connect),
3999 		   proto_method_implemented(proto->disconnect),
4000 		   proto_method_implemented(proto->accept),
4001 		   proto_method_implemented(proto->ioctl),
4002 		   proto_method_implemented(proto->init),
4003 		   proto_method_implemented(proto->destroy),
4004 		   proto_method_implemented(proto->shutdown),
4005 		   proto_method_implemented(proto->setsockopt),
4006 		   proto_method_implemented(proto->getsockopt),
4007 		   proto_method_implemented(proto->sendmsg),
4008 		   proto_method_implemented(proto->recvmsg),
4009 		   proto_method_implemented(proto->sendpage),
4010 		   proto_method_implemented(proto->bind),
4011 		   proto_method_implemented(proto->backlog_rcv),
4012 		   proto_method_implemented(proto->hash),
4013 		   proto_method_implemented(proto->unhash),
4014 		   proto_method_implemented(proto->get_port),
4015 		   proto_method_implemented(proto->enter_memory_pressure));
4016 }
4017 
4018 static int proto_seq_show(struct seq_file *seq, void *v)
4019 {
4020 	if (v == &proto_list)
4021 		seq_printf(seq, "%-9s %-4s %-8s %-6s %-5s %-7s %-4s %-10s %s",
4022 			   "protocol",
4023 			   "size",
4024 			   "sockets",
4025 			   "memory",
4026 			   "press",
4027 			   "maxhdr",
4028 			   "slab",
4029 			   "module",
4030 			   "cl co di ac io in de sh ss gs se re sp bi br ha uh gp em\n");
4031 	else
4032 		proto_seq_printf(seq, list_entry(v, struct proto, node));
4033 	return 0;
4034 }
4035 
4036 static const struct seq_operations proto_seq_ops = {
4037 	.start  = proto_seq_start,
4038 	.next   = proto_seq_next,
4039 	.stop   = proto_seq_stop,
4040 	.show   = proto_seq_show,
4041 };
4042 
4043 static __net_init int proto_init_net(struct net *net)
4044 {
4045 	if (!proc_create_net("protocols", 0444, net->proc_net, &proto_seq_ops,
4046 			sizeof(struct seq_net_private)))
4047 		return -ENOMEM;
4048 
4049 	return 0;
4050 }
4051 
4052 static __net_exit void proto_exit_net(struct net *net)
4053 {
4054 	remove_proc_entry("protocols", net->proc_net);
4055 }
4056 
4057 
4058 static __net_initdata struct pernet_operations proto_net_ops = {
4059 	.init = proto_init_net,
4060 	.exit = proto_exit_net,
4061 };
4062 
4063 static int __init proto_init(void)
4064 {
4065 	return register_pernet_subsys(&proto_net_ops);
4066 }
4067 
4068 subsys_initcall(proto_init);
4069 
4070 #endif /* PROC_FS */
4071 
4072 #ifdef CONFIG_NET_RX_BUSY_POLL
4073 bool sk_busy_loop_end(void *p, unsigned long start_time)
4074 {
4075 	struct sock *sk = p;
4076 
4077 	return !skb_queue_empty_lockless(&sk->sk_receive_queue) ||
4078 	       sk_busy_loop_timeout(sk, start_time);
4079 }
4080 EXPORT_SYMBOL(sk_busy_loop_end);
4081 #endif /* CONFIG_NET_RX_BUSY_POLL */
4082 
4083 int sock_bind_add(struct sock *sk, struct sockaddr *addr, int addr_len)
4084 {
4085 	if (!sk->sk_prot->bind_add)
4086 		return -EOPNOTSUPP;
4087 	return sk->sk_prot->bind_add(sk, addr, addr_len);
4088 }
4089 EXPORT_SYMBOL(sock_bind_add);
4090