xref: /linux/net/core/sock.c (revision 6e94dbc7a4e49a028b81302d755bba1a518f973b)
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 static DEFINE_MUTEX(proto_list_mutex);
143 static LIST_HEAD(proto_list);
144 
145 static void sock_inuse_add(struct net *net, int val);
146 
147 /**
148  * sk_ns_capable - General socket capability test
149  * @sk: Socket to use a capability on or through
150  * @user_ns: The user namespace of the capability to use
151  * @cap: The capability to use
152  *
153  * Test to see if the opener of the socket had when the socket was
154  * created and the current process has the capability @cap in the user
155  * namespace @user_ns.
156  */
157 bool sk_ns_capable(const struct sock *sk,
158 		   struct user_namespace *user_ns, int cap)
159 {
160 	return file_ns_capable(sk->sk_socket->file, user_ns, cap) &&
161 		ns_capable(user_ns, cap);
162 }
163 EXPORT_SYMBOL(sk_ns_capable);
164 
165 /**
166  * sk_capable - Socket global capability test
167  * @sk: Socket to use a capability on or through
168  * @cap: The global capability to use
169  *
170  * Test to see if the opener of the socket had when the socket was
171  * created and the current process has the capability @cap in all user
172  * namespaces.
173  */
174 bool sk_capable(const struct sock *sk, int cap)
175 {
176 	return sk_ns_capable(sk, &init_user_ns, cap);
177 }
178 EXPORT_SYMBOL(sk_capable);
179 
180 /**
181  * sk_net_capable - Network namespace socket capability test
182  * @sk: Socket to use a capability on or through
183  * @cap: The capability to use
184  *
185  * Test to see if the opener of the socket had when the socket was created
186  * and the current process has the capability @cap over the network namespace
187  * the socket is a member of.
188  */
189 bool sk_net_capable(const struct sock *sk, int cap)
190 {
191 	return sk_ns_capable(sk, sock_net(sk)->user_ns, cap);
192 }
193 EXPORT_SYMBOL(sk_net_capable);
194 
195 /*
196  * Each address family might have different locking rules, so we have
197  * one slock key per address family and separate keys for internal and
198  * userspace sockets.
199  */
200 static struct lock_class_key af_family_keys[AF_MAX];
201 static struct lock_class_key af_family_kern_keys[AF_MAX];
202 static struct lock_class_key af_family_slock_keys[AF_MAX];
203 static struct lock_class_key af_family_kern_slock_keys[AF_MAX];
204 
205 /*
206  * Make lock validator output more readable. (we pre-construct these
207  * strings build-time, so that runtime initialization of socket
208  * locks is fast):
209  */
210 
211 #define _sock_locks(x)						  \
212   x "AF_UNSPEC",	x "AF_UNIX"     ,	x "AF_INET"     , \
213   x "AF_AX25"  ,	x "AF_IPX"      ,	x "AF_APPLETALK", \
214   x "AF_NETROM",	x "AF_BRIDGE"   ,	x "AF_ATMPVC"   , \
215   x "AF_X25"   ,	x "AF_INET6"    ,	x "AF_ROSE"     , \
216   x "AF_DECnet",	x "AF_NETBEUI"  ,	x "AF_SECURITY" , \
217   x "AF_KEY"   ,	x "AF_NETLINK"  ,	x "AF_PACKET"   , \
218   x "AF_ASH"   ,	x "AF_ECONET"   ,	x "AF_ATMSVC"   , \
219   x "AF_RDS"   ,	x "AF_SNA"      ,	x "AF_IRDA"     , \
220   x "AF_PPPOX" ,	x "AF_WANPIPE"  ,	x "AF_LLC"      , \
221   x "27"       ,	x "28"          ,	x "AF_CAN"      , \
222   x "AF_TIPC"  ,	x "AF_BLUETOOTH",	x "IUCV"        , \
223   x "AF_RXRPC" ,	x "AF_ISDN"     ,	x "AF_PHONET"   , \
224   x "AF_IEEE802154",	x "AF_CAIF"	,	x "AF_ALG"      , \
225   x "AF_NFC"   ,	x "AF_VSOCK"    ,	x "AF_KCM"      , \
226   x "AF_QIPCRTR",	x "AF_SMC"	,	x "AF_XDP"	, \
227   x "AF_MAX"
228 
229 static const char *const af_family_key_strings[AF_MAX+1] = {
230 	_sock_locks("sk_lock-")
231 };
232 static const char *const af_family_slock_key_strings[AF_MAX+1] = {
233 	_sock_locks("slock-")
234 };
235 static const char *const af_family_clock_key_strings[AF_MAX+1] = {
236 	_sock_locks("clock-")
237 };
238 
239 static const char *const af_family_kern_key_strings[AF_MAX+1] = {
240 	_sock_locks("k-sk_lock-")
241 };
242 static const char *const af_family_kern_slock_key_strings[AF_MAX+1] = {
243 	_sock_locks("k-slock-")
244 };
245 static const char *const af_family_kern_clock_key_strings[AF_MAX+1] = {
246 	_sock_locks("k-clock-")
247 };
248 static const char *const af_family_rlock_key_strings[AF_MAX+1] = {
249 	_sock_locks("rlock-")
250 };
251 static const char *const af_family_wlock_key_strings[AF_MAX+1] = {
252 	_sock_locks("wlock-")
253 };
254 static const char *const af_family_elock_key_strings[AF_MAX+1] = {
255 	_sock_locks("elock-")
256 };
257 
258 /*
259  * sk_callback_lock and sk queues locking rules are per-address-family,
260  * so split the lock classes by using a per-AF key:
261  */
262 static struct lock_class_key af_callback_keys[AF_MAX];
263 static struct lock_class_key af_rlock_keys[AF_MAX];
264 static struct lock_class_key af_wlock_keys[AF_MAX];
265 static struct lock_class_key af_elock_keys[AF_MAX];
266 static struct lock_class_key af_kern_callback_keys[AF_MAX];
267 
268 /* Run time adjustable parameters. */
269 __u32 sysctl_wmem_max __read_mostly = SK_WMEM_MAX;
270 EXPORT_SYMBOL(sysctl_wmem_max);
271 __u32 sysctl_rmem_max __read_mostly = SK_RMEM_MAX;
272 EXPORT_SYMBOL(sysctl_rmem_max);
273 __u32 sysctl_wmem_default __read_mostly = SK_WMEM_MAX;
274 __u32 sysctl_rmem_default __read_mostly = SK_RMEM_MAX;
275 
276 /* Maximal space eaten by iovec or ancillary data plus some space */
277 int sysctl_optmem_max __read_mostly = sizeof(unsigned long)*(2*UIO_MAXIOV+512);
278 EXPORT_SYMBOL(sysctl_optmem_max);
279 
280 int sysctl_tstamp_allow_data __read_mostly = 1;
281 
282 DEFINE_STATIC_KEY_FALSE(memalloc_socks_key);
283 EXPORT_SYMBOL_GPL(memalloc_socks_key);
284 
285 /**
286  * sk_set_memalloc - sets %SOCK_MEMALLOC
287  * @sk: socket to set it on
288  *
289  * Set %SOCK_MEMALLOC on a socket for access to emergency reserves.
290  * It's the responsibility of the admin to adjust min_free_kbytes
291  * to meet the requirements
292  */
293 void sk_set_memalloc(struct sock *sk)
294 {
295 	sock_set_flag(sk, SOCK_MEMALLOC);
296 	sk->sk_allocation |= __GFP_MEMALLOC;
297 	static_branch_inc(&memalloc_socks_key);
298 }
299 EXPORT_SYMBOL_GPL(sk_set_memalloc);
300 
301 void sk_clear_memalloc(struct sock *sk)
302 {
303 	sock_reset_flag(sk, SOCK_MEMALLOC);
304 	sk->sk_allocation &= ~__GFP_MEMALLOC;
305 	static_branch_dec(&memalloc_socks_key);
306 
307 	/*
308 	 * SOCK_MEMALLOC is allowed to ignore rmem limits to ensure forward
309 	 * progress of swapping. SOCK_MEMALLOC may be cleared while
310 	 * it has rmem allocations due to the last swapfile being deactivated
311 	 * but there is a risk that the socket is unusable due to exceeding
312 	 * the rmem limits. Reclaim the reserves and obey rmem limits again.
313 	 */
314 	sk_mem_reclaim(sk);
315 }
316 EXPORT_SYMBOL_GPL(sk_clear_memalloc);
317 
318 int __sk_backlog_rcv(struct sock *sk, struct sk_buff *skb)
319 {
320 	int ret;
321 	unsigned int noreclaim_flag;
322 
323 	/* these should have been dropped before queueing */
324 	BUG_ON(!sock_flag(sk, SOCK_MEMALLOC));
325 
326 	noreclaim_flag = memalloc_noreclaim_save();
327 	ret = sk->sk_backlog_rcv(sk, skb);
328 	memalloc_noreclaim_restore(noreclaim_flag);
329 
330 	return ret;
331 }
332 EXPORT_SYMBOL(__sk_backlog_rcv);
333 
334 static int sock_get_timeout(long timeo, void *optval, bool old_timeval)
335 {
336 	struct __kernel_sock_timeval tv;
337 
338 	if (timeo == MAX_SCHEDULE_TIMEOUT) {
339 		tv.tv_sec = 0;
340 		tv.tv_usec = 0;
341 	} else {
342 		tv.tv_sec = timeo / HZ;
343 		tv.tv_usec = ((timeo % HZ) * USEC_PER_SEC) / HZ;
344 	}
345 
346 	if (old_timeval && in_compat_syscall() && !COMPAT_USE_64BIT_TIME) {
347 		struct old_timeval32 tv32 = { tv.tv_sec, tv.tv_usec };
348 		*(struct old_timeval32 *)optval = tv32;
349 		return sizeof(tv32);
350 	}
351 
352 	if (old_timeval) {
353 		struct __kernel_old_timeval old_tv;
354 		old_tv.tv_sec = tv.tv_sec;
355 		old_tv.tv_usec = tv.tv_usec;
356 		*(struct __kernel_old_timeval *)optval = old_tv;
357 		return sizeof(old_tv);
358 	}
359 
360 	*(struct __kernel_sock_timeval *)optval = tv;
361 	return sizeof(tv);
362 }
363 
364 static int sock_set_timeout(long *timeo_p, sockptr_t optval, int optlen,
365 			    bool old_timeval)
366 {
367 	struct __kernel_sock_timeval tv;
368 
369 	if (old_timeval && in_compat_syscall() && !COMPAT_USE_64BIT_TIME) {
370 		struct old_timeval32 tv32;
371 
372 		if (optlen < sizeof(tv32))
373 			return -EINVAL;
374 
375 		if (copy_from_sockptr(&tv32, optval, sizeof(tv32)))
376 			return -EFAULT;
377 		tv.tv_sec = tv32.tv_sec;
378 		tv.tv_usec = tv32.tv_usec;
379 	} else if (old_timeval) {
380 		struct __kernel_old_timeval old_tv;
381 
382 		if (optlen < sizeof(old_tv))
383 			return -EINVAL;
384 		if (copy_from_sockptr(&old_tv, optval, sizeof(old_tv)))
385 			return -EFAULT;
386 		tv.tv_sec = old_tv.tv_sec;
387 		tv.tv_usec = old_tv.tv_usec;
388 	} else {
389 		if (optlen < sizeof(tv))
390 			return -EINVAL;
391 		if (copy_from_sockptr(&tv, optval, sizeof(tv)))
392 			return -EFAULT;
393 	}
394 	if (tv.tv_usec < 0 || tv.tv_usec >= USEC_PER_SEC)
395 		return -EDOM;
396 
397 	if (tv.tv_sec < 0) {
398 		static int warned __read_mostly;
399 
400 		*timeo_p = 0;
401 		if (warned < 10 && net_ratelimit()) {
402 			warned++;
403 			pr_info("%s: `%s' (pid %d) tries to set negative timeout\n",
404 				__func__, current->comm, task_pid_nr(current));
405 		}
406 		return 0;
407 	}
408 	*timeo_p = MAX_SCHEDULE_TIMEOUT;
409 	if (tv.tv_sec == 0 && tv.tv_usec == 0)
410 		return 0;
411 	if (tv.tv_sec < (MAX_SCHEDULE_TIMEOUT / HZ - 1))
412 		*timeo_p = tv.tv_sec * HZ + DIV_ROUND_UP((unsigned long)tv.tv_usec, USEC_PER_SEC / HZ);
413 	return 0;
414 }
415 
416 static bool sock_needs_netstamp(const struct sock *sk)
417 {
418 	switch (sk->sk_family) {
419 	case AF_UNSPEC:
420 	case AF_UNIX:
421 		return false;
422 	default:
423 		return true;
424 	}
425 }
426 
427 static void sock_disable_timestamp(struct sock *sk, unsigned long flags)
428 {
429 	if (sk->sk_flags & flags) {
430 		sk->sk_flags &= ~flags;
431 		if (sock_needs_netstamp(sk) &&
432 		    !(sk->sk_flags & SK_FLAGS_TIMESTAMP))
433 			net_disable_timestamp();
434 	}
435 }
436 
437 
438 int __sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
439 {
440 	unsigned long flags;
441 	struct sk_buff_head *list = &sk->sk_receive_queue;
442 
443 	if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf) {
444 		atomic_inc(&sk->sk_drops);
445 		trace_sock_rcvqueue_full(sk, skb);
446 		return -ENOMEM;
447 	}
448 
449 	if (!sk_rmem_schedule(sk, skb, skb->truesize)) {
450 		atomic_inc(&sk->sk_drops);
451 		return -ENOBUFS;
452 	}
453 
454 	skb->dev = NULL;
455 	skb_set_owner_r(skb, sk);
456 
457 	/* we escape from rcu protected region, make sure we dont leak
458 	 * a norefcounted dst
459 	 */
460 	skb_dst_force(skb);
461 
462 	spin_lock_irqsave(&list->lock, flags);
463 	sock_skb_set_dropcount(sk, skb);
464 	__skb_queue_tail(list, skb);
465 	spin_unlock_irqrestore(&list->lock, flags);
466 
467 	if (!sock_flag(sk, SOCK_DEAD))
468 		sk->sk_data_ready(sk);
469 	return 0;
470 }
471 EXPORT_SYMBOL(__sock_queue_rcv_skb);
472 
473 int sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
474 {
475 	int err;
476 
477 	err = sk_filter(sk, skb);
478 	if (err)
479 		return err;
480 
481 	return __sock_queue_rcv_skb(sk, skb);
482 }
483 EXPORT_SYMBOL(sock_queue_rcv_skb);
484 
485 int __sk_receive_skb(struct sock *sk, struct sk_buff *skb,
486 		     const int nested, unsigned int trim_cap, bool refcounted)
487 {
488 	int rc = NET_RX_SUCCESS;
489 
490 	if (sk_filter_trim_cap(sk, skb, trim_cap))
491 		goto discard_and_relse;
492 
493 	skb->dev = NULL;
494 
495 	if (sk_rcvqueues_full(sk, sk->sk_rcvbuf)) {
496 		atomic_inc(&sk->sk_drops);
497 		goto discard_and_relse;
498 	}
499 	if (nested)
500 		bh_lock_sock_nested(sk);
501 	else
502 		bh_lock_sock(sk);
503 	if (!sock_owned_by_user(sk)) {
504 		/*
505 		 * trylock + unlock semantics:
506 		 */
507 		mutex_acquire(&sk->sk_lock.dep_map, 0, 1, _RET_IP_);
508 
509 		rc = sk_backlog_rcv(sk, skb);
510 
511 		mutex_release(&sk->sk_lock.dep_map, _RET_IP_);
512 	} else if (sk_add_backlog(sk, skb, READ_ONCE(sk->sk_rcvbuf))) {
513 		bh_unlock_sock(sk);
514 		atomic_inc(&sk->sk_drops);
515 		goto discard_and_relse;
516 	}
517 
518 	bh_unlock_sock(sk);
519 out:
520 	if (refcounted)
521 		sock_put(sk);
522 	return rc;
523 discard_and_relse:
524 	kfree_skb(skb);
525 	goto out;
526 }
527 EXPORT_SYMBOL(__sk_receive_skb);
528 
529 INDIRECT_CALLABLE_DECLARE(struct dst_entry *ip6_dst_check(struct dst_entry *,
530 							  u32));
531 INDIRECT_CALLABLE_DECLARE(struct dst_entry *ipv4_dst_check(struct dst_entry *,
532 							   u32));
533 struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie)
534 {
535 	struct dst_entry *dst = __sk_dst_get(sk);
536 
537 	if (dst && dst->obsolete &&
538 	    INDIRECT_CALL_INET(dst->ops->check, ip6_dst_check, ipv4_dst_check,
539 			       dst, cookie) == NULL) {
540 		sk_tx_queue_clear(sk);
541 		sk->sk_dst_pending_confirm = 0;
542 		RCU_INIT_POINTER(sk->sk_dst_cache, NULL);
543 		dst_release(dst);
544 		return NULL;
545 	}
546 
547 	return dst;
548 }
549 EXPORT_SYMBOL(__sk_dst_check);
550 
551 struct dst_entry *sk_dst_check(struct sock *sk, u32 cookie)
552 {
553 	struct dst_entry *dst = sk_dst_get(sk);
554 
555 	if (dst && dst->obsolete &&
556 	    INDIRECT_CALL_INET(dst->ops->check, ip6_dst_check, ipv4_dst_check,
557 			       dst, cookie) == NULL) {
558 		sk_dst_reset(sk);
559 		dst_release(dst);
560 		return NULL;
561 	}
562 
563 	return dst;
564 }
565 EXPORT_SYMBOL(sk_dst_check);
566 
567 static int sock_bindtoindex_locked(struct sock *sk, int ifindex)
568 {
569 	int ret = -ENOPROTOOPT;
570 #ifdef CONFIG_NETDEVICES
571 	struct net *net = sock_net(sk);
572 
573 	/* Sorry... */
574 	ret = -EPERM;
575 	if (sk->sk_bound_dev_if && !ns_capable(net->user_ns, CAP_NET_RAW))
576 		goto out;
577 
578 	ret = -EINVAL;
579 	if (ifindex < 0)
580 		goto out;
581 
582 	sk->sk_bound_dev_if = ifindex;
583 	if (sk->sk_prot->rehash)
584 		sk->sk_prot->rehash(sk);
585 	sk_dst_reset(sk);
586 
587 	ret = 0;
588 
589 out:
590 #endif
591 
592 	return ret;
593 }
594 
595 int sock_bindtoindex(struct sock *sk, int ifindex, bool lock_sk)
596 {
597 	int ret;
598 
599 	if (lock_sk)
600 		lock_sock(sk);
601 	ret = sock_bindtoindex_locked(sk, ifindex);
602 	if (lock_sk)
603 		release_sock(sk);
604 
605 	return ret;
606 }
607 EXPORT_SYMBOL(sock_bindtoindex);
608 
609 static int sock_setbindtodevice(struct sock *sk, sockptr_t optval, int optlen)
610 {
611 	int ret = -ENOPROTOOPT;
612 #ifdef CONFIG_NETDEVICES
613 	struct net *net = sock_net(sk);
614 	char devname[IFNAMSIZ];
615 	int index;
616 
617 	ret = -EINVAL;
618 	if (optlen < 0)
619 		goto out;
620 
621 	/* Bind this socket to a particular device like "eth0",
622 	 * as specified in the passed interface name. If the
623 	 * name is "" or the option length is zero the socket
624 	 * is not bound.
625 	 */
626 	if (optlen > IFNAMSIZ - 1)
627 		optlen = IFNAMSIZ - 1;
628 	memset(devname, 0, sizeof(devname));
629 
630 	ret = -EFAULT;
631 	if (copy_from_sockptr(devname, optval, optlen))
632 		goto out;
633 
634 	index = 0;
635 	if (devname[0] != '\0') {
636 		struct net_device *dev;
637 
638 		rcu_read_lock();
639 		dev = dev_get_by_name_rcu(net, devname);
640 		if (dev)
641 			index = dev->ifindex;
642 		rcu_read_unlock();
643 		ret = -ENODEV;
644 		if (!dev)
645 			goto out;
646 	}
647 
648 	return sock_bindtoindex(sk, index, true);
649 out:
650 #endif
651 
652 	return ret;
653 }
654 
655 static int sock_getbindtodevice(struct sock *sk, char __user *optval,
656 				int __user *optlen, int len)
657 {
658 	int ret = -ENOPROTOOPT;
659 #ifdef CONFIG_NETDEVICES
660 	struct net *net = sock_net(sk);
661 	char devname[IFNAMSIZ];
662 
663 	if (sk->sk_bound_dev_if == 0) {
664 		len = 0;
665 		goto zero;
666 	}
667 
668 	ret = -EINVAL;
669 	if (len < IFNAMSIZ)
670 		goto out;
671 
672 	ret = netdev_get_name(net, devname, sk->sk_bound_dev_if);
673 	if (ret)
674 		goto out;
675 
676 	len = strlen(devname) + 1;
677 
678 	ret = -EFAULT;
679 	if (copy_to_user(optval, devname, len))
680 		goto out;
681 
682 zero:
683 	ret = -EFAULT;
684 	if (put_user(len, optlen))
685 		goto out;
686 
687 	ret = 0;
688 
689 out:
690 #endif
691 
692 	return ret;
693 }
694 
695 bool sk_mc_loop(struct sock *sk)
696 {
697 	if (dev_recursion_level())
698 		return false;
699 	if (!sk)
700 		return true;
701 	switch (sk->sk_family) {
702 	case AF_INET:
703 		return inet_sk(sk)->mc_loop;
704 #if IS_ENABLED(CONFIG_IPV6)
705 	case AF_INET6:
706 		return inet6_sk(sk)->mc_loop;
707 #endif
708 	}
709 	WARN_ON_ONCE(1);
710 	return true;
711 }
712 EXPORT_SYMBOL(sk_mc_loop);
713 
714 void sock_set_reuseaddr(struct sock *sk)
715 {
716 	lock_sock(sk);
717 	sk->sk_reuse = SK_CAN_REUSE;
718 	release_sock(sk);
719 }
720 EXPORT_SYMBOL(sock_set_reuseaddr);
721 
722 void sock_set_reuseport(struct sock *sk)
723 {
724 	lock_sock(sk);
725 	sk->sk_reuseport = true;
726 	release_sock(sk);
727 }
728 EXPORT_SYMBOL(sock_set_reuseport);
729 
730 void sock_no_linger(struct sock *sk)
731 {
732 	lock_sock(sk);
733 	sk->sk_lingertime = 0;
734 	sock_set_flag(sk, SOCK_LINGER);
735 	release_sock(sk);
736 }
737 EXPORT_SYMBOL(sock_no_linger);
738 
739 void sock_set_priority(struct sock *sk, u32 priority)
740 {
741 	lock_sock(sk);
742 	sk->sk_priority = priority;
743 	release_sock(sk);
744 }
745 EXPORT_SYMBOL(sock_set_priority);
746 
747 void sock_set_sndtimeo(struct sock *sk, s64 secs)
748 {
749 	lock_sock(sk);
750 	if (secs && secs < MAX_SCHEDULE_TIMEOUT / HZ - 1)
751 		sk->sk_sndtimeo = secs * HZ;
752 	else
753 		sk->sk_sndtimeo = MAX_SCHEDULE_TIMEOUT;
754 	release_sock(sk);
755 }
756 EXPORT_SYMBOL(sock_set_sndtimeo);
757 
758 static void __sock_set_timestamps(struct sock *sk, bool val, bool new, bool ns)
759 {
760 	if (val)  {
761 		sock_valbool_flag(sk, SOCK_TSTAMP_NEW, new);
762 		sock_valbool_flag(sk, SOCK_RCVTSTAMPNS, ns);
763 		sock_set_flag(sk, SOCK_RCVTSTAMP);
764 		sock_enable_timestamp(sk, SOCK_TIMESTAMP);
765 	} else {
766 		sock_reset_flag(sk, SOCK_RCVTSTAMP);
767 		sock_reset_flag(sk, SOCK_RCVTSTAMPNS);
768 	}
769 }
770 
771 void sock_enable_timestamps(struct sock *sk)
772 {
773 	lock_sock(sk);
774 	__sock_set_timestamps(sk, true, false, true);
775 	release_sock(sk);
776 }
777 EXPORT_SYMBOL(sock_enable_timestamps);
778 
779 void sock_set_keepalive(struct sock *sk)
780 {
781 	lock_sock(sk);
782 	if (sk->sk_prot->keepalive)
783 		sk->sk_prot->keepalive(sk, true);
784 	sock_valbool_flag(sk, SOCK_KEEPOPEN, true);
785 	release_sock(sk);
786 }
787 EXPORT_SYMBOL(sock_set_keepalive);
788 
789 static void __sock_set_rcvbuf(struct sock *sk, int val)
790 {
791 	/* Ensure val * 2 fits into an int, to prevent max_t() from treating it
792 	 * as a negative value.
793 	 */
794 	val = min_t(int, val, INT_MAX / 2);
795 	sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
796 
797 	/* We double it on the way in to account for "struct sk_buff" etc.
798 	 * overhead.   Applications assume that the SO_RCVBUF setting they make
799 	 * will allow that much actual data to be received on that socket.
800 	 *
801 	 * Applications are unaware that "struct sk_buff" and other overheads
802 	 * allocate from the receive buffer during socket buffer allocation.
803 	 *
804 	 * And after considering the possible alternatives, returning the value
805 	 * we actually used in getsockopt is the most desirable behavior.
806 	 */
807 	WRITE_ONCE(sk->sk_rcvbuf, max_t(int, val * 2, SOCK_MIN_RCVBUF));
808 }
809 
810 void sock_set_rcvbuf(struct sock *sk, int val)
811 {
812 	lock_sock(sk);
813 	__sock_set_rcvbuf(sk, val);
814 	release_sock(sk);
815 }
816 EXPORT_SYMBOL(sock_set_rcvbuf);
817 
818 void sock_set_mark(struct sock *sk, u32 val)
819 {
820 	lock_sock(sk);
821 	sk->sk_mark = val;
822 	release_sock(sk);
823 }
824 EXPORT_SYMBOL(sock_set_mark);
825 
826 /*
827  *	This is meant for all protocols to use and covers goings on
828  *	at the socket level. Everything here is generic.
829  */
830 
831 int sock_setsockopt(struct socket *sock, int level, int optname,
832 		    sockptr_t optval, unsigned int optlen)
833 {
834 	struct sock_txtime sk_txtime;
835 	struct sock *sk = sock->sk;
836 	int val;
837 	int valbool;
838 	struct linger ling;
839 	int ret = 0;
840 
841 	/*
842 	 *	Options without arguments
843 	 */
844 
845 	if (optname == SO_BINDTODEVICE)
846 		return sock_setbindtodevice(sk, optval, optlen);
847 
848 	if (optlen < sizeof(int))
849 		return -EINVAL;
850 
851 	if (copy_from_sockptr(&val, optval, sizeof(val)))
852 		return -EFAULT;
853 
854 	valbool = val ? 1 : 0;
855 
856 	lock_sock(sk);
857 
858 	switch (optname) {
859 	case SO_DEBUG:
860 		if (val && !capable(CAP_NET_ADMIN))
861 			ret = -EACCES;
862 		else
863 			sock_valbool_flag(sk, SOCK_DBG, valbool);
864 		break;
865 	case SO_REUSEADDR:
866 		sk->sk_reuse = (valbool ? SK_CAN_REUSE : SK_NO_REUSE);
867 		break;
868 	case SO_REUSEPORT:
869 		sk->sk_reuseport = valbool;
870 		break;
871 	case SO_TYPE:
872 	case SO_PROTOCOL:
873 	case SO_DOMAIN:
874 	case SO_ERROR:
875 		ret = -ENOPROTOOPT;
876 		break;
877 	case SO_DONTROUTE:
878 		sock_valbool_flag(sk, SOCK_LOCALROUTE, valbool);
879 		sk_dst_reset(sk);
880 		break;
881 	case SO_BROADCAST:
882 		sock_valbool_flag(sk, SOCK_BROADCAST, valbool);
883 		break;
884 	case SO_SNDBUF:
885 		/* Don't error on this BSD doesn't and if you think
886 		 * about it this is right. Otherwise apps have to
887 		 * play 'guess the biggest size' games. RCVBUF/SNDBUF
888 		 * are treated in BSD as hints
889 		 */
890 		val = min_t(u32, val, sysctl_wmem_max);
891 set_sndbuf:
892 		/* Ensure val * 2 fits into an int, to prevent max_t()
893 		 * from treating it as a negative value.
894 		 */
895 		val = min_t(int, val, INT_MAX / 2);
896 		sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
897 		WRITE_ONCE(sk->sk_sndbuf,
898 			   max_t(int, val * 2, SOCK_MIN_SNDBUF));
899 		/* Wake up sending tasks if we upped the value. */
900 		sk->sk_write_space(sk);
901 		break;
902 
903 	case SO_SNDBUFFORCE:
904 		if (!capable(CAP_NET_ADMIN)) {
905 			ret = -EPERM;
906 			break;
907 		}
908 
909 		/* No negative values (to prevent underflow, as val will be
910 		 * multiplied by 2).
911 		 */
912 		if (val < 0)
913 			val = 0;
914 		goto set_sndbuf;
915 
916 	case SO_RCVBUF:
917 		/* Don't error on this BSD doesn't and if you think
918 		 * about it this is right. Otherwise apps have to
919 		 * play 'guess the biggest size' games. RCVBUF/SNDBUF
920 		 * are treated in BSD as hints
921 		 */
922 		__sock_set_rcvbuf(sk, min_t(u32, val, sysctl_rmem_max));
923 		break;
924 
925 	case SO_RCVBUFFORCE:
926 		if (!capable(CAP_NET_ADMIN)) {
927 			ret = -EPERM;
928 			break;
929 		}
930 
931 		/* No negative values (to prevent underflow, as val will be
932 		 * multiplied by 2).
933 		 */
934 		__sock_set_rcvbuf(sk, max(val, 0));
935 		break;
936 
937 	case SO_KEEPALIVE:
938 		if (sk->sk_prot->keepalive)
939 			sk->sk_prot->keepalive(sk, valbool);
940 		sock_valbool_flag(sk, SOCK_KEEPOPEN, valbool);
941 		break;
942 
943 	case SO_OOBINLINE:
944 		sock_valbool_flag(sk, SOCK_URGINLINE, valbool);
945 		break;
946 
947 	case SO_NO_CHECK:
948 		sk->sk_no_check_tx = valbool;
949 		break;
950 
951 	case SO_PRIORITY:
952 		if ((val >= 0 && val <= 6) ||
953 		    ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
954 			sk->sk_priority = val;
955 		else
956 			ret = -EPERM;
957 		break;
958 
959 	case SO_LINGER:
960 		if (optlen < sizeof(ling)) {
961 			ret = -EINVAL;	/* 1003.1g */
962 			break;
963 		}
964 		if (copy_from_sockptr(&ling, optval, sizeof(ling))) {
965 			ret = -EFAULT;
966 			break;
967 		}
968 		if (!ling.l_onoff)
969 			sock_reset_flag(sk, SOCK_LINGER);
970 		else {
971 #if (BITS_PER_LONG == 32)
972 			if ((unsigned int)ling.l_linger >= MAX_SCHEDULE_TIMEOUT/HZ)
973 				sk->sk_lingertime = MAX_SCHEDULE_TIMEOUT;
974 			else
975 #endif
976 				sk->sk_lingertime = (unsigned int)ling.l_linger * HZ;
977 			sock_set_flag(sk, SOCK_LINGER);
978 		}
979 		break;
980 
981 	case SO_BSDCOMPAT:
982 		break;
983 
984 	case SO_PASSCRED:
985 		if (valbool)
986 			set_bit(SOCK_PASSCRED, &sock->flags);
987 		else
988 			clear_bit(SOCK_PASSCRED, &sock->flags);
989 		break;
990 
991 	case SO_TIMESTAMP_OLD:
992 		__sock_set_timestamps(sk, valbool, false, false);
993 		break;
994 	case SO_TIMESTAMP_NEW:
995 		__sock_set_timestamps(sk, valbool, true, false);
996 		break;
997 	case SO_TIMESTAMPNS_OLD:
998 		__sock_set_timestamps(sk, valbool, false, true);
999 		break;
1000 	case SO_TIMESTAMPNS_NEW:
1001 		__sock_set_timestamps(sk, valbool, true, true);
1002 		break;
1003 	case SO_TIMESTAMPING_NEW:
1004 	case SO_TIMESTAMPING_OLD:
1005 		if (val & ~SOF_TIMESTAMPING_MASK) {
1006 			ret = -EINVAL;
1007 			break;
1008 		}
1009 
1010 		if (val & SOF_TIMESTAMPING_OPT_ID &&
1011 		    !(sk->sk_tsflags & SOF_TIMESTAMPING_OPT_ID)) {
1012 			if (sk->sk_protocol == IPPROTO_TCP &&
1013 			    sk->sk_type == SOCK_STREAM) {
1014 				if ((1 << sk->sk_state) &
1015 				    (TCPF_CLOSE | TCPF_LISTEN)) {
1016 					ret = -EINVAL;
1017 					break;
1018 				}
1019 				sk->sk_tskey = tcp_sk(sk)->snd_una;
1020 			} else {
1021 				sk->sk_tskey = 0;
1022 			}
1023 		}
1024 
1025 		if (val & SOF_TIMESTAMPING_OPT_STATS &&
1026 		    !(val & SOF_TIMESTAMPING_OPT_TSONLY)) {
1027 			ret = -EINVAL;
1028 			break;
1029 		}
1030 
1031 		sk->sk_tsflags = val;
1032 		sock_valbool_flag(sk, SOCK_TSTAMP_NEW, optname == SO_TIMESTAMPING_NEW);
1033 
1034 		if (val & SOF_TIMESTAMPING_RX_SOFTWARE)
1035 			sock_enable_timestamp(sk,
1036 					      SOCK_TIMESTAMPING_RX_SOFTWARE);
1037 		else
1038 			sock_disable_timestamp(sk,
1039 					       (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE));
1040 		break;
1041 
1042 	case SO_RCVLOWAT:
1043 		if (val < 0)
1044 			val = INT_MAX;
1045 		if (sock->ops->set_rcvlowat)
1046 			ret = sock->ops->set_rcvlowat(sk, val);
1047 		else
1048 			WRITE_ONCE(sk->sk_rcvlowat, val ? : 1);
1049 		break;
1050 
1051 	case SO_RCVTIMEO_OLD:
1052 	case SO_RCVTIMEO_NEW:
1053 		ret = sock_set_timeout(&sk->sk_rcvtimeo, optval,
1054 				       optlen, optname == SO_RCVTIMEO_OLD);
1055 		break;
1056 
1057 	case SO_SNDTIMEO_OLD:
1058 	case SO_SNDTIMEO_NEW:
1059 		ret = sock_set_timeout(&sk->sk_sndtimeo, optval,
1060 				       optlen, optname == SO_SNDTIMEO_OLD);
1061 		break;
1062 
1063 	case SO_ATTACH_FILTER: {
1064 		struct sock_fprog fprog;
1065 
1066 		ret = copy_bpf_fprog_from_user(&fprog, optval, optlen);
1067 		if (!ret)
1068 			ret = sk_attach_filter(&fprog, sk);
1069 		break;
1070 	}
1071 	case SO_ATTACH_BPF:
1072 		ret = -EINVAL;
1073 		if (optlen == sizeof(u32)) {
1074 			u32 ufd;
1075 
1076 			ret = -EFAULT;
1077 			if (copy_from_sockptr(&ufd, optval, sizeof(ufd)))
1078 				break;
1079 
1080 			ret = sk_attach_bpf(ufd, sk);
1081 		}
1082 		break;
1083 
1084 	case SO_ATTACH_REUSEPORT_CBPF: {
1085 		struct sock_fprog fprog;
1086 
1087 		ret = copy_bpf_fprog_from_user(&fprog, optval, optlen);
1088 		if (!ret)
1089 			ret = sk_reuseport_attach_filter(&fprog, sk);
1090 		break;
1091 	}
1092 	case SO_ATTACH_REUSEPORT_EBPF:
1093 		ret = -EINVAL;
1094 		if (optlen == sizeof(u32)) {
1095 			u32 ufd;
1096 
1097 			ret = -EFAULT;
1098 			if (copy_from_sockptr(&ufd, optval, sizeof(ufd)))
1099 				break;
1100 
1101 			ret = sk_reuseport_attach_bpf(ufd, sk);
1102 		}
1103 		break;
1104 
1105 	case SO_DETACH_REUSEPORT_BPF:
1106 		ret = reuseport_detach_prog(sk);
1107 		break;
1108 
1109 	case SO_DETACH_FILTER:
1110 		ret = sk_detach_filter(sk);
1111 		break;
1112 
1113 	case SO_LOCK_FILTER:
1114 		if (sock_flag(sk, SOCK_FILTER_LOCKED) && !valbool)
1115 			ret = -EPERM;
1116 		else
1117 			sock_valbool_flag(sk, SOCK_FILTER_LOCKED, valbool);
1118 		break;
1119 
1120 	case SO_PASSSEC:
1121 		if (valbool)
1122 			set_bit(SOCK_PASSSEC, &sock->flags);
1123 		else
1124 			clear_bit(SOCK_PASSSEC, &sock->flags);
1125 		break;
1126 	case SO_MARK:
1127 		if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) {
1128 			ret = -EPERM;
1129 		} else if (val != sk->sk_mark) {
1130 			sk->sk_mark = val;
1131 			sk_dst_reset(sk);
1132 		}
1133 		break;
1134 
1135 	case SO_RXQ_OVFL:
1136 		sock_valbool_flag(sk, SOCK_RXQ_OVFL, valbool);
1137 		break;
1138 
1139 	case SO_WIFI_STATUS:
1140 		sock_valbool_flag(sk, SOCK_WIFI_STATUS, valbool);
1141 		break;
1142 
1143 	case SO_PEEK_OFF:
1144 		if (sock->ops->set_peek_off)
1145 			ret = sock->ops->set_peek_off(sk, val);
1146 		else
1147 			ret = -EOPNOTSUPP;
1148 		break;
1149 
1150 	case SO_NOFCS:
1151 		sock_valbool_flag(sk, SOCK_NOFCS, valbool);
1152 		break;
1153 
1154 	case SO_SELECT_ERR_QUEUE:
1155 		sock_valbool_flag(sk, SOCK_SELECT_ERR_QUEUE, valbool);
1156 		break;
1157 
1158 #ifdef CONFIG_NET_RX_BUSY_POLL
1159 	case SO_BUSY_POLL:
1160 		/* allow unprivileged users to decrease the value */
1161 		if ((val > sk->sk_ll_usec) && !capable(CAP_NET_ADMIN))
1162 			ret = -EPERM;
1163 		else {
1164 			if (val < 0)
1165 				ret = -EINVAL;
1166 			else
1167 				sk->sk_ll_usec = val;
1168 		}
1169 		break;
1170 	case SO_PREFER_BUSY_POLL:
1171 		if (valbool && !capable(CAP_NET_ADMIN))
1172 			ret = -EPERM;
1173 		else
1174 			WRITE_ONCE(sk->sk_prefer_busy_poll, valbool);
1175 		break;
1176 	case SO_BUSY_POLL_BUDGET:
1177 		if (val > READ_ONCE(sk->sk_busy_poll_budget) && !capable(CAP_NET_ADMIN)) {
1178 			ret = -EPERM;
1179 		} else {
1180 			if (val < 0 || val > U16_MAX)
1181 				ret = -EINVAL;
1182 			else
1183 				WRITE_ONCE(sk->sk_busy_poll_budget, val);
1184 		}
1185 		break;
1186 #endif
1187 
1188 	case SO_MAX_PACING_RATE:
1189 		{
1190 		unsigned long ulval = (val == ~0U) ? ~0UL : (unsigned int)val;
1191 
1192 		if (sizeof(ulval) != sizeof(val) &&
1193 		    optlen >= sizeof(ulval) &&
1194 		    copy_from_sockptr(&ulval, optval, sizeof(ulval))) {
1195 			ret = -EFAULT;
1196 			break;
1197 		}
1198 		if (ulval != ~0UL)
1199 			cmpxchg(&sk->sk_pacing_status,
1200 				SK_PACING_NONE,
1201 				SK_PACING_NEEDED);
1202 		sk->sk_max_pacing_rate = ulval;
1203 		sk->sk_pacing_rate = min(sk->sk_pacing_rate, ulval);
1204 		break;
1205 		}
1206 	case SO_INCOMING_CPU:
1207 		WRITE_ONCE(sk->sk_incoming_cpu, val);
1208 		break;
1209 
1210 	case SO_CNX_ADVICE:
1211 		if (val == 1)
1212 			dst_negative_advice(sk);
1213 		break;
1214 
1215 	case SO_ZEROCOPY:
1216 		if (sk->sk_family == PF_INET || sk->sk_family == PF_INET6) {
1217 			if (!((sk->sk_type == SOCK_STREAM &&
1218 			       sk->sk_protocol == IPPROTO_TCP) ||
1219 			      (sk->sk_type == SOCK_DGRAM &&
1220 			       sk->sk_protocol == IPPROTO_UDP)))
1221 				ret = -ENOTSUPP;
1222 		} else if (sk->sk_family != PF_RDS) {
1223 			ret = -ENOTSUPP;
1224 		}
1225 		if (!ret) {
1226 			if (val < 0 || val > 1)
1227 				ret = -EINVAL;
1228 			else
1229 				sock_valbool_flag(sk, SOCK_ZEROCOPY, valbool);
1230 		}
1231 		break;
1232 
1233 	case SO_TXTIME:
1234 		if (optlen != sizeof(struct sock_txtime)) {
1235 			ret = -EINVAL;
1236 			break;
1237 		} else if (copy_from_sockptr(&sk_txtime, optval,
1238 			   sizeof(struct sock_txtime))) {
1239 			ret = -EFAULT;
1240 			break;
1241 		} else if (sk_txtime.flags & ~SOF_TXTIME_FLAGS_MASK) {
1242 			ret = -EINVAL;
1243 			break;
1244 		}
1245 		/* CLOCK_MONOTONIC is only used by sch_fq, and this packet
1246 		 * scheduler has enough safe guards.
1247 		 */
1248 		if (sk_txtime.clockid != CLOCK_MONOTONIC &&
1249 		    !ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) {
1250 			ret = -EPERM;
1251 			break;
1252 		}
1253 		sock_valbool_flag(sk, SOCK_TXTIME, true);
1254 		sk->sk_clockid = sk_txtime.clockid;
1255 		sk->sk_txtime_deadline_mode =
1256 			!!(sk_txtime.flags & SOF_TXTIME_DEADLINE_MODE);
1257 		sk->sk_txtime_report_errors =
1258 			!!(sk_txtime.flags & SOF_TXTIME_REPORT_ERRORS);
1259 		break;
1260 
1261 	case SO_BINDTOIFINDEX:
1262 		ret = sock_bindtoindex_locked(sk, val);
1263 		break;
1264 
1265 	default:
1266 		ret = -ENOPROTOOPT;
1267 		break;
1268 	}
1269 	release_sock(sk);
1270 	return ret;
1271 }
1272 EXPORT_SYMBOL(sock_setsockopt);
1273 
1274 
1275 static void cred_to_ucred(struct pid *pid, const struct cred *cred,
1276 			  struct ucred *ucred)
1277 {
1278 	ucred->pid = pid_vnr(pid);
1279 	ucred->uid = ucred->gid = -1;
1280 	if (cred) {
1281 		struct user_namespace *current_ns = current_user_ns();
1282 
1283 		ucred->uid = from_kuid_munged(current_ns, cred->euid);
1284 		ucred->gid = from_kgid_munged(current_ns, cred->egid);
1285 	}
1286 }
1287 
1288 static int groups_to_user(gid_t __user *dst, const struct group_info *src)
1289 {
1290 	struct user_namespace *user_ns = current_user_ns();
1291 	int i;
1292 
1293 	for (i = 0; i < src->ngroups; i++)
1294 		if (put_user(from_kgid_munged(user_ns, src->gid[i]), dst + i))
1295 			return -EFAULT;
1296 
1297 	return 0;
1298 }
1299 
1300 int sock_getsockopt(struct socket *sock, int level, int optname,
1301 		    char __user *optval, int __user *optlen)
1302 {
1303 	struct sock *sk = sock->sk;
1304 
1305 	union {
1306 		int val;
1307 		u64 val64;
1308 		unsigned long ulval;
1309 		struct linger ling;
1310 		struct old_timeval32 tm32;
1311 		struct __kernel_old_timeval tm;
1312 		struct  __kernel_sock_timeval stm;
1313 		struct sock_txtime txtime;
1314 	} v;
1315 
1316 	int lv = sizeof(int);
1317 	int len;
1318 
1319 	if (get_user(len, optlen))
1320 		return -EFAULT;
1321 	if (len < 0)
1322 		return -EINVAL;
1323 
1324 	memset(&v, 0, sizeof(v));
1325 
1326 	switch (optname) {
1327 	case SO_DEBUG:
1328 		v.val = sock_flag(sk, SOCK_DBG);
1329 		break;
1330 
1331 	case SO_DONTROUTE:
1332 		v.val = sock_flag(sk, SOCK_LOCALROUTE);
1333 		break;
1334 
1335 	case SO_BROADCAST:
1336 		v.val = sock_flag(sk, SOCK_BROADCAST);
1337 		break;
1338 
1339 	case SO_SNDBUF:
1340 		v.val = sk->sk_sndbuf;
1341 		break;
1342 
1343 	case SO_RCVBUF:
1344 		v.val = sk->sk_rcvbuf;
1345 		break;
1346 
1347 	case SO_REUSEADDR:
1348 		v.val = sk->sk_reuse;
1349 		break;
1350 
1351 	case SO_REUSEPORT:
1352 		v.val = sk->sk_reuseport;
1353 		break;
1354 
1355 	case SO_KEEPALIVE:
1356 		v.val = sock_flag(sk, SOCK_KEEPOPEN);
1357 		break;
1358 
1359 	case SO_TYPE:
1360 		v.val = sk->sk_type;
1361 		break;
1362 
1363 	case SO_PROTOCOL:
1364 		v.val = sk->sk_protocol;
1365 		break;
1366 
1367 	case SO_DOMAIN:
1368 		v.val = sk->sk_family;
1369 		break;
1370 
1371 	case SO_ERROR:
1372 		v.val = -sock_error(sk);
1373 		if (v.val == 0)
1374 			v.val = xchg(&sk->sk_err_soft, 0);
1375 		break;
1376 
1377 	case SO_OOBINLINE:
1378 		v.val = sock_flag(sk, SOCK_URGINLINE);
1379 		break;
1380 
1381 	case SO_NO_CHECK:
1382 		v.val = sk->sk_no_check_tx;
1383 		break;
1384 
1385 	case SO_PRIORITY:
1386 		v.val = sk->sk_priority;
1387 		break;
1388 
1389 	case SO_LINGER:
1390 		lv		= sizeof(v.ling);
1391 		v.ling.l_onoff	= sock_flag(sk, SOCK_LINGER);
1392 		v.ling.l_linger	= sk->sk_lingertime / HZ;
1393 		break;
1394 
1395 	case SO_BSDCOMPAT:
1396 		break;
1397 
1398 	case SO_TIMESTAMP_OLD:
1399 		v.val = sock_flag(sk, SOCK_RCVTSTAMP) &&
1400 				!sock_flag(sk, SOCK_TSTAMP_NEW) &&
1401 				!sock_flag(sk, SOCK_RCVTSTAMPNS);
1402 		break;
1403 
1404 	case SO_TIMESTAMPNS_OLD:
1405 		v.val = sock_flag(sk, SOCK_RCVTSTAMPNS) && !sock_flag(sk, SOCK_TSTAMP_NEW);
1406 		break;
1407 
1408 	case SO_TIMESTAMP_NEW:
1409 		v.val = sock_flag(sk, SOCK_RCVTSTAMP) && sock_flag(sk, SOCK_TSTAMP_NEW);
1410 		break;
1411 
1412 	case SO_TIMESTAMPNS_NEW:
1413 		v.val = sock_flag(sk, SOCK_RCVTSTAMPNS) && sock_flag(sk, SOCK_TSTAMP_NEW);
1414 		break;
1415 
1416 	case SO_TIMESTAMPING_OLD:
1417 		v.val = sk->sk_tsflags;
1418 		break;
1419 
1420 	case SO_RCVTIMEO_OLD:
1421 	case SO_RCVTIMEO_NEW:
1422 		lv = sock_get_timeout(sk->sk_rcvtimeo, &v, SO_RCVTIMEO_OLD == optname);
1423 		break;
1424 
1425 	case SO_SNDTIMEO_OLD:
1426 	case SO_SNDTIMEO_NEW:
1427 		lv = sock_get_timeout(sk->sk_sndtimeo, &v, SO_SNDTIMEO_OLD == optname);
1428 		break;
1429 
1430 	case SO_RCVLOWAT:
1431 		v.val = sk->sk_rcvlowat;
1432 		break;
1433 
1434 	case SO_SNDLOWAT:
1435 		v.val = 1;
1436 		break;
1437 
1438 	case SO_PASSCRED:
1439 		v.val = !!test_bit(SOCK_PASSCRED, &sock->flags);
1440 		break;
1441 
1442 	case SO_PEERCRED:
1443 	{
1444 		struct ucred peercred;
1445 		if (len > sizeof(peercred))
1446 			len = sizeof(peercred);
1447 		cred_to_ucred(sk->sk_peer_pid, sk->sk_peer_cred, &peercred);
1448 		if (copy_to_user(optval, &peercred, len))
1449 			return -EFAULT;
1450 		goto lenout;
1451 	}
1452 
1453 	case SO_PEERGROUPS:
1454 	{
1455 		int ret, n;
1456 
1457 		if (!sk->sk_peer_cred)
1458 			return -ENODATA;
1459 
1460 		n = sk->sk_peer_cred->group_info->ngroups;
1461 		if (len < n * sizeof(gid_t)) {
1462 			len = n * sizeof(gid_t);
1463 			return put_user(len, optlen) ? -EFAULT : -ERANGE;
1464 		}
1465 		len = n * sizeof(gid_t);
1466 
1467 		ret = groups_to_user((gid_t __user *)optval,
1468 				     sk->sk_peer_cred->group_info);
1469 		if (ret)
1470 			return ret;
1471 		goto lenout;
1472 	}
1473 
1474 	case SO_PEERNAME:
1475 	{
1476 		char address[128];
1477 
1478 		lv = sock->ops->getname(sock, (struct sockaddr *)address, 2);
1479 		if (lv < 0)
1480 			return -ENOTCONN;
1481 		if (lv < len)
1482 			return -EINVAL;
1483 		if (copy_to_user(optval, address, len))
1484 			return -EFAULT;
1485 		goto lenout;
1486 	}
1487 
1488 	/* Dubious BSD thing... Probably nobody even uses it, but
1489 	 * the UNIX standard wants it for whatever reason... -DaveM
1490 	 */
1491 	case SO_ACCEPTCONN:
1492 		v.val = sk->sk_state == TCP_LISTEN;
1493 		break;
1494 
1495 	case SO_PASSSEC:
1496 		v.val = !!test_bit(SOCK_PASSSEC, &sock->flags);
1497 		break;
1498 
1499 	case SO_PEERSEC:
1500 		return security_socket_getpeersec_stream(sock, optval, optlen, len);
1501 
1502 	case SO_MARK:
1503 		v.val = sk->sk_mark;
1504 		break;
1505 
1506 	case SO_RXQ_OVFL:
1507 		v.val = sock_flag(sk, SOCK_RXQ_OVFL);
1508 		break;
1509 
1510 	case SO_WIFI_STATUS:
1511 		v.val = sock_flag(sk, SOCK_WIFI_STATUS);
1512 		break;
1513 
1514 	case SO_PEEK_OFF:
1515 		if (!sock->ops->set_peek_off)
1516 			return -EOPNOTSUPP;
1517 
1518 		v.val = sk->sk_peek_off;
1519 		break;
1520 	case SO_NOFCS:
1521 		v.val = sock_flag(sk, SOCK_NOFCS);
1522 		break;
1523 
1524 	case SO_BINDTODEVICE:
1525 		return sock_getbindtodevice(sk, optval, optlen, len);
1526 
1527 	case SO_GET_FILTER:
1528 		len = sk_get_filter(sk, (struct sock_filter __user *)optval, len);
1529 		if (len < 0)
1530 			return len;
1531 
1532 		goto lenout;
1533 
1534 	case SO_LOCK_FILTER:
1535 		v.val = sock_flag(sk, SOCK_FILTER_LOCKED);
1536 		break;
1537 
1538 	case SO_BPF_EXTENSIONS:
1539 		v.val = bpf_tell_extensions();
1540 		break;
1541 
1542 	case SO_SELECT_ERR_QUEUE:
1543 		v.val = sock_flag(sk, SOCK_SELECT_ERR_QUEUE);
1544 		break;
1545 
1546 #ifdef CONFIG_NET_RX_BUSY_POLL
1547 	case SO_BUSY_POLL:
1548 		v.val = sk->sk_ll_usec;
1549 		break;
1550 	case SO_PREFER_BUSY_POLL:
1551 		v.val = READ_ONCE(sk->sk_prefer_busy_poll);
1552 		break;
1553 #endif
1554 
1555 	case SO_MAX_PACING_RATE:
1556 		if (sizeof(v.ulval) != sizeof(v.val) && len >= sizeof(v.ulval)) {
1557 			lv = sizeof(v.ulval);
1558 			v.ulval = sk->sk_max_pacing_rate;
1559 		} else {
1560 			/* 32bit version */
1561 			v.val = min_t(unsigned long, sk->sk_max_pacing_rate, ~0U);
1562 		}
1563 		break;
1564 
1565 	case SO_INCOMING_CPU:
1566 		v.val = READ_ONCE(sk->sk_incoming_cpu);
1567 		break;
1568 
1569 	case SO_MEMINFO:
1570 	{
1571 		u32 meminfo[SK_MEMINFO_VARS];
1572 
1573 		sk_get_meminfo(sk, meminfo);
1574 
1575 		len = min_t(unsigned int, len, sizeof(meminfo));
1576 		if (copy_to_user(optval, &meminfo, len))
1577 			return -EFAULT;
1578 
1579 		goto lenout;
1580 	}
1581 
1582 #ifdef CONFIG_NET_RX_BUSY_POLL
1583 	case SO_INCOMING_NAPI_ID:
1584 		v.val = READ_ONCE(sk->sk_napi_id);
1585 
1586 		/* aggregate non-NAPI IDs down to 0 */
1587 		if (v.val < MIN_NAPI_ID)
1588 			v.val = 0;
1589 
1590 		break;
1591 #endif
1592 
1593 	case SO_COOKIE:
1594 		lv = sizeof(u64);
1595 		if (len < lv)
1596 			return -EINVAL;
1597 		v.val64 = sock_gen_cookie(sk);
1598 		break;
1599 
1600 	case SO_ZEROCOPY:
1601 		v.val = sock_flag(sk, SOCK_ZEROCOPY);
1602 		break;
1603 
1604 	case SO_TXTIME:
1605 		lv = sizeof(v.txtime);
1606 		v.txtime.clockid = sk->sk_clockid;
1607 		v.txtime.flags |= sk->sk_txtime_deadline_mode ?
1608 				  SOF_TXTIME_DEADLINE_MODE : 0;
1609 		v.txtime.flags |= sk->sk_txtime_report_errors ?
1610 				  SOF_TXTIME_REPORT_ERRORS : 0;
1611 		break;
1612 
1613 	case SO_BINDTOIFINDEX:
1614 		v.val = sk->sk_bound_dev_if;
1615 		break;
1616 
1617 	default:
1618 		/* We implement the SO_SNDLOWAT etc to not be settable
1619 		 * (1003.1g 7).
1620 		 */
1621 		return -ENOPROTOOPT;
1622 	}
1623 
1624 	if (len > lv)
1625 		len = lv;
1626 	if (copy_to_user(optval, &v, len))
1627 		return -EFAULT;
1628 lenout:
1629 	if (put_user(len, optlen))
1630 		return -EFAULT;
1631 	return 0;
1632 }
1633 
1634 /*
1635  * Initialize an sk_lock.
1636  *
1637  * (We also register the sk_lock with the lock validator.)
1638  */
1639 static inline void sock_lock_init(struct sock *sk)
1640 {
1641 	if (sk->sk_kern_sock)
1642 		sock_lock_init_class_and_name(
1643 			sk,
1644 			af_family_kern_slock_key_strings[sk->sk_family],
1645 			af_family_kern_slock_keys + sk->sk_family,
1646 			af_family_kern_key_strings[sk->sk_family],
1647 			af_family_kern_keys + sk->sk_family);
1648 	else
1649 		sock_lock_init_class_and_name(
1650 			sk,
1651 			af_family_slock_key_strings[sk->sk_family],
1652 			af_family_slock_keys + sk->sk_family,
1653 			af_family_key_strings[sk->sk_family],
1654 			af_family_keys + sk->sk_family);
1655 }
1656 
1657 /*
1658  * Copy all fields from osk to nsk but nsk->sk_refcnt must not change yet,
1659  * even temporarly, because of RCU lookups. sk_node should also be left as is.
1660  * We must not copy fields between sk_dontcopy_begin and sk_dontcopy_end
1661  */
1662 static void sock_copy(struct sock *nsk, const struct sock *osk)
1663 {
1664 	const struct proto *prot = READ_ONCE(osk->sk_prot);
1665 #ifdef CONFIG_SECURITY_NETWORK
1666 	void *sptr = nsk->sk_security;
1667 #endif
1668 
1669 	/* If we move sk_tx_queue_mapping out of the private section,
1670 	 * we must check if sk_tx_queue_clear() is called after
1671 	 * sock_copy() in sk_clone_lock().
1672 	 */
1673 	BUILD_BUG_ON(offsetof(struct sock, sk_tx_queue_mapping) <
1674 		     offsetof(struct sock, sk_dontcopy_begin) ||
1675 		     offsetof(struct sock, sk_tx_queue_mapping) >=
1676 		     offsetof(struct sock, sk_dontcopy_end));
1677 
1678 	memcpy(nsk, osk, offsetof(struct sock, sk_dontcopy_begin));
1679 
1680 	memcpy(&nsk->sk_dontcopy_end, &osk->sk_dontcopy_end,
1681 	       prot->obj_size - offsetof(struct sock, sk_dontcopy_end));
1682 
1683 #ifdef CONFIG_SECURITY_NETWORK
1684 	nsk->sk_security = sptr;
1685 	security_sk_clone(osk, nsk);
1686 #endif
1687 }
1688 
1689 static struct sock *sk_prot_alloc(struct proto *prot, gfp_t priority,
1690 		int family)
1691 {
1692 	struct sock *sk;
1693 	struct kmem_cache *slab;
1694 
1695 	slab = prot->slab;
1696 	if (slab != NULL) {
1697 		sk = kmem_cache_alloc(slab, priority & ~__GFP_ZERO);
1698 		if (!sk)
1699 			return sk;
1700 		if (want_init_on_alloc(priority))
1701 			sk_prot_clear_nulls(sk, prot->obj_size);
1702 	} else
1703 		sk = kmalloc(prot->obj_size, priority);
1704 
1705 	if (sk != NULL) {
1706 		if (security_sk_alloc(sk, family, priority))
1707 			goto out_free;
1708 
1709 		if (!try_module_get(prot->owner))
1710 			goto out_free_sec;
1711 	}
1712 
1713 	return sk;
1714 
1715 out_free_sec:
1716 	security_sk_free(sk);
1717 out_free:
1718 	if (slab != NULL)
1719 		kmem_cache_free(slab, sk);
1720 	else
1721 		kfree(sk);
1722 	return NULL;
1723 }
1724 
1725 static void sk_prot_free(struct proto *prot, struct sock *sk)
1726 {
1727 	struct kmem_cache *slab;
1728 	struct module *owner;
1729 
1730 	owner = prot->owner;
1731 	slab = prot->slab;
1732 
1733 	cgroup_sk_free(&sk->sk_cgrp_data);
1734 	mem_cgroup_sk_free(sk);
1735 	security_sk_free(sk);
1736 	if (slab != NULL)
1737 		kmem_cache_free(slab, sk);
1738 	else
1739 		kfree(sk);
1740 	module_put(owner);
1741 }
1742 
1743 /**
1744  *	sk_alloc - All socket objects are allocated here
1745  *	@net: the applicable net namespace
1746  *	@family: protocol family
1747  *	@priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
1748  *	@prot: struct proto associated with this new sock instance
1749  *	@kern: is this to be a kernel socket?
1750  */
1751 struct sock *sk_alloc(struct net *net, int family, gfp_t priority,
1752 		      struct proto *prot, int kern)
1753 {
1754 	struct sock *sk;
1755 
1756 	sk = sk_prot_alloc(prot, priority | __GFP_ZERO, family);
1757 	if (sk) {
1758 		sk->sk_family = family;
1759 		/*
1760 		 * See comment in struct sock definition to understand
1761 		 * why we need sk_prot_creator -acme
1762 		 */
1763 		sk->sk_prot = sk->sk_prot_creator = prot;
1764 		sk->sk_kern_sock = kern;
1765 		sock_lock_init(sk);
1766 		sk->sk_net_refcnt = kern ? 0 : 1;
1767 		if (likely(sk->sk_net_refcnt)) {
1768 			get_net(net);
1769 			sock_inuse_add(net, 1);
1770 		}
1771 
1772 		sock_net_set(sk, net);
1773 		refcount_set(&sk->sk_wmem_alloc, 1);
1774 
1775 		mem_cgroup_sk_alloc(sk);
1776 		cgroup_sk_alloc(&sk->sk_cgrp_data);
1777 		sock_update_classid(&sk->sk_cgrp_data);
1778 		sock_update_netprioidx(&sk->sk_cgrp_data);
1779 		sk_tx_queue_clear(sk);
1780 	}
1781 
1782 	return sk;
1783 }
1784 EXPORT_SYMBOL(sk_alloc);
1785 
1786 /* Sockets having SOCK_RCU_FREE will call this function after one RCU
1787  * grace period. This is the case for UDP sockets and TCP listeners.
1788  */
1789 static void __sk_destruct(struct rcu_head *head)
1790 {
1791 	struct sock *sk = container_of(head, struct sock, sk_rcu);
1792 	struct sk_filter *filter;
1793 
1794 	if (sk->sk_destruct)
1795 		sk->sk_destruct(sk);
1796 
1797 	filter = rcu_dereference_check(sk->sk_filter,
1798 				       refcount_read(&sk->sk_wmem_alloc) == 0);
1799 	if (filter) {
1800 		sk_filter_uncharge(sk, filter);
1801 		RCU_INIT_POINTER(sk->sk_filter, NULL);
1802 	}
1803 
1804 	sock_disable_timestamp(sk, SK_FLAGS_TIMESTAMP);
1805 
1806 #ifdef CONFIG_BPF_SYSCALL
1807 	bpf_sk_storage_free(sk);
1808 #endif
1809 
1810 	if (atomic_read(&sk->sk_omem_alloc))
1811 		pr_debug("%s: optmem leakage (%d bytes) detected\n",
1812 			 __func__, atomic_read(&sk->sk_omem_alloc));
1813 
1814 	if (sk->sk_frag.page) {
1815 		put_page(sk->sk_frag.page);
1816 		sk->sk_frag.page = NULL;
1817 	}
1818 
1819 	if (sk->sk_peer_cred)
1820 		put_cred(sk->sk_peer_cred);
1821 	put_pid(sk->sk_peer_pid);
1822 	if (likely(sk->sk_net_refcnt))
1823 		put_net(sock_net(sk));
1824 	sk_prot_free(sk->sk_prot_creator, sk);
1825 }
1826 
1827 void sk_destruct(struct sock *sk)
1828 {
1829 	bool use_call_rcu = sock_flag(sk, SOCK_RCU_FREE);
1830 
1831 	if (rcu_access_pointer(sk->sk_reuseport_cb)) {
1832 		reuseport_detach_sock(sk);
1833 		use_call_rcu = true;
1834 	}
1835 
1836 	if (use_call_rcu)
1837 		call_rcu(&sk->sk_rcu, __sk_destruct);
1838 	else
1839 		__sk_destruct(&sk->sk_rcu);
1840 }
1841 
1842 static void __sk_free(struct sock *sk)
1843 {
1844 	if (likely(sk->sk_net_refcnt))
1845 		sock_inuse_add(sock_net(sk), -1);
1846 
1847 	if (unlikely(sk->sk_net_refcnt && sock_diag_has_destroy_listeners(sk)))
1848 		sock_diag_broadcast_destroy(sk);
1849 	else
1850 		sk_destruct(sk);
1851 }
1852 
1853 void sk_free(struct sock *sk)
1854 {
1855 	/*
1856 	 * We subtract one from sk_wmem_alloc and can know if
1857 	 * some packets are still in some tx queue.
1858 	 * If not null, sock_wfree() will call __sk_free(sk) later
1859 	 */
1860 	if (refcount_dec_and_test(&sk->sk_wmem_alloc))
1861 		__sk_free(sk);
1862 }
1863 EXPORT_SYMBOL(sk_free);
1864 
1865 static void sk_init_common(struct sock *sk)
1866 {
1867 	skb_queue_head_init(&sk->sk_receive_queue);
1868 	skb_queue_head_init(&sk->sk_write_queue);
1869 	skb_queue_head_init(&sk->sk_error_queue);
1870 
1871 	rwlock_init(&sk->sk_callback_lock);
1872 	lockdep_set_class_and_name(&sk->sk_receive_queue.lock,
1873 			af_rlock_keys + sk->sk_family,
1874 			af_family_rlock_key_strings[sk->sk_family]);
1875 	lockdep_set_class_and_name(&sk->sk_write_queue.lock,
1876 			af_wlock_keys + sk->sk_family,
1877 			af_family_wlock_key_strings[sk->sk_family]);
1878 	lockdep_set_class_and_name(&sk->sk_error_queue.lock,
1879 			af_elock_keys + sk->sk_family,
1880 			af_family_elock_key_strings[sk->sk_family]);
1881 	lockdep_set_class_and_name(&sk->sk_callback_lock,
1882 			af_callback_keys + sk->sk_family,
1883 			af_family_clock_key_strings[sk->sk_family]);
1884 }
1885 
1886 /**
1887  *	sk_clone_lock - clone a socket, and lock its clone
1888  *	@sk: the socket to clone
1889  *	@priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
1890  *
1891  *	Caller must unlock socket even in error path (bh_unlock_sock(newsk))
1892  */
1893 struct sock *sk_clone_lock(const struct sock *sk, const gfp_t priority)
1894 {
1895 	struct proto *prot = READ_ONCE(sk->sk_prot);
1896 	struct sk_filter *filter;
1897 	bool is_charged = true;
1898 	struct sock *newsk;
1899 
1900 	newsk = sk_prot_alloc(prot, priority, sk->sk_family);
1901 	if (!newsk)
1902 		goto out;
1903 
1904 	sock_copy(newsk, sk);
1905 
1906 	newsk->sk_prot_creator = prot;
1907 
1908 	/* SANITY */
1909 	if (likely(newsk->sk_net_refcnt))
1910 		get_net(sock_net(newsk));
1911 	sk_node_init(&newsk->sk_node);
1912 	sock_lock_init(newsk);
1913 	bh_lock_sock(newsk);
1914 	newsk->sk_backlog.head	= newsk->sk_backlog.tail = NULL;
1915 	newsk->sk_backlog.len = 0;
1916 
1917 	atomic_set(&newsk->sk_rmem_alloc, 0);
1918 
1919 	/* sk_wmem_alloc set to one (see sk_free() and sock_wfree()) */
1920 	refcount_set(&newsk->sk_wmem_alloc, 1);
1921 
1922 	atomic_set(&newsk->sk_omem_alloc, 0);
1923 	sk_init_common(newsk);
1924 
1925 	newsk->sk_dst_cache	= NULL;
1926 	newsk->sk_dst_pending_confirm = 0;
1927 	newsk->sk_wmem_queued	= 0;
1928 	newsk->sk_forward_alloc = 0;
1929 	atomic_set(&newsk->sk_drops, 0);
1930 	newsk->sk_send_head	= NULL;
1931 	newsk->sk_userlocks	= sk->sk_userlocks & ~SOCK_BINDPORT_LOCK;
1932 	atomic_set(&newsk->sk_zckey, 0);
1933 
1934 	sock_reset_flag(newsk, SOCK_DONE);
1935 
1936 	/* sk->sk_memcg will be populated at accept() time */
1937 	newsk->sk_memcg = NULL;
1938 
1939 	cgroup_sk_clone(&newsk->sk_cgrp_data);
1940 
1941 	rcu_read_lock();
1942 	filter = rcu_dereference(sk->sk_filter);
1943 	if (filter != NULL)
1944 		/* though it's an empty new sock, the charging may fail
1945 		 * if sysctl_optmem_max was changed between creation of
1946 		 * original socket and cloning
1947 		 */
1948 		is_charged = sk_filter_charge(newsk, filter);
1949 	RCU_INIT_POINTER(newsk->sk_filter, filter);
1950 	rcu_read_unlock();
1951 
1952 	if (unlikely(!is_charged || xfrm_sk_clone_policy(newsk, sk))) {
1953 		/* We need to make sure that we don't uncharge the new
1954 		 * socket if we couldn't charge it in the first place
1955 		 * as otherwise we uncharge the parent's filter.
1956 		 */
1957 		if (!is_charged)
1958 			RCU_INIT_POINTER(newsk->sk_filter, NULL);
1959 		sk_free_unlock_clone(newsk);
1960 		newsk = NULL;
1961 		goto out;
1962 	}
1963 	RCU_INIT_POINTER(newsk->sk_reuseport_cb, NULL);
1964 
1965 	if (bpf_sk_storage_clone(sk, newsk)) {
1966 		sk_free_unlock_clone(newsk);
1967 		newsk = NULL;
1968 		goto out;
1969 	}
1970 
1971 	/* Clear sk_user_data if parent had the pointer tagged
1972 	 * as not suitable for copying when cloning.
1973 	 */
1974 	if (sk_user_data_is_nocopy(newsk))
1975 		newsk->sk_user_data = NULL;
1976 
1977 	newsk->sk_err	   = 0;
1978 	newsk->sk_err_soft = 0;
1979 	newsk->sk_priority = 0;
1980 	newsk->sk_incoming_cpu = raw_smp_processor_id();
1981 	if (likely(newsk->sk_net_refcnt))
1982 		sock_inuse_add(sock_net(newsk), 1);
1983 
1984 	/* Before updating sk_refcnt, we must commit prior changes to memory
1985 	 * (Documentation/RCU/rculist_nulls.rst for details)
1986 	 */
1987 	smp_wmb();
1988 	refcount_set(&newsk->sk_refcnt, 2);
1989 
1990 	/* Increment the counter in the same struct proto as the master
1991 	 * sock (sk_refcnt_debug_inc uses newsk->sk_prot->socks, that
1992 	 * is the same as sk->sk_prot->socks, as this field was copied
1993 	 * with memcpy).
1994 	 *
1995 	 * This _changes_ the previous behaviour, where
1996 	 * tcp_create_openreq_child always was incrementing the
1997 	 * equivalent to tcp_prot->socks (inet_sock_nr), so this have
1998 	 * to be taken into account in all callers. -acme
1999 	 */
2000 	sk_refcnt_debug_inc(newsk);
2001 	sk_set_socket(newsk, NULL);
2002 	sk_tx_queue_clear(newsk);
2003 	RCU_INIT_POINTER(newsk->sk_wq, NULL);
2004 
2005 	if (newsk->sk_prot->sockets_allocated)
2006 		sk_sockets_allocated_inc(newsk);
2007 
2008 	if (sock_needs_netstamp(sk) && newsk->sk_flags & SK_FLAGS_TIMESTAMP)
2009 		net_enable_timestamp();
2010 out:
2011 	return newsk;
2012 }
2013 EXPORT_SYMBOL_GPL(sk_clone_lock);
2014 
2015 void sk_free_unlock_clone(struct sock *sk)
2016 {
2017 	/* It is still raw copy of parent, so invalidate
2018 	 * destructor and make plain sk_free() */
2019 	sk->sk_destruct = NULL;
2020 	bh_unlock_sock(sk);
2021 	sk_free(sk);
2022 }
2023 EXPORT_SYMBOL_GPL(sk_free_unlock_clone);
2024 
2025 void sk_setup_caps(struct sock *sk, struct dst_entry *dst)
2026 {
2027 	u32 max_segs = 1;
2028 
2029 	sk_dst_set(sk, dst);
2030 	sk->sk_route_caps = dst->dev->features | sk->sk_route_forced_caps;
2031 	if (sk->sk_route_caps & NETIF_F_GSO)
2032 		sk->sk_route_caps |= NETIF_F_GSO_SOFTWARE;
2033 	sk->sk_route_caps &= ~sk->sk_route_nocaps;
2034 	if (sk_can_gso(sk)) {
2035 		if (dst->header_len && !xfrm_dst_offload_ok(dst)) {
2036 			sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
2037 		} else {
2038 			sk->sk_route_caps |= NETIF_F_SG | NETIF_F_HW_CSUM;
2039 			sk->sk_gso_max_size = dst->dev->gso_max_size;
2040 			max_segs = max_t(u32, dst->dev->gso_max_segs, 1);
2041 		}
2042 	}
2043 	sk->sk_gso_max_segs = max_segs;
2044 }
2045 EXPORT_SYMBOL_GPL(sk_setup_caps);
2046 
2047 /*
2048  *	Simple resource managers for sockets.
2049  */
2050 
2051 
2052 /*
2053  * Write buffer destructor automatically called from kfree_skb.
2054  */
2055 void sock_wfree(struct sk_buff *skb)
2056 {
2057 	struct sock *sk = skb->sk;
2058 	unsigned int len = skb->truesize;
2059 
2060 	if (!sock_flag(sk, SOCK_USE_WRITE_QUEUE)) {
2061 		/*
2062 		 * Keep a reference on sk_wmem_alloc, this will be released
2063 		 * after sk_write_space() call
2064 		 */
2065 		WARN_ON(refcount_sub_and_test(len - 1, &sk->sk_wmem_alloc));
2066 		sk->sk_write_space(sk);
2067 		len = 1;
2068 	}
2069 	/*
2070 	 * if sk_wmem_alloc reaches 0, we must finish what sk_free()
2071 	 * could not do because of in-flight packets
2072 	 */
2073 	if (refcount_sub_and_test(len, &sk->sk_wmem_alloc))
2074 		__sk_free(sk);
2075 }
2076 EXPORT_SYMBOL(sock_wfree);
2077 
2078 /* This variant of sock_wfree() is used by TCP,
2079  * since it sets SOCK_USE_WRITE_QUEUE.
2080  */
2081 void __sock_wfree(struct sk_buff *skb)
2082 {
2083 	struct sock *sk = skb->sk;
2084 
2085 	if (refcount_sub_and_test(skb->truesize, &sk->sk_wmem_alloc))
2086 		__sk_free(sk);
2087 }
2088 
2089 void skb_set_owner_w(struct sk_buff *skb, struct sock *sk)
2090 {
2091 	skb_orphan(skb);
2092 	skb->sk = sk;
2093 #ifdef CONFIG_INET
2094 	if (unlikely(!sk_fullsock(sk))) {
2095 		skb->destructor = sock_edemux;
2096 		sock_hold(sk);
2097 		return;
2098 	}
2099 #endif
2100 	skb->destructor = sock_wfree;
2101 	skb_set_hash_from_sk(skb, sk);
2102 	/*
2103 	 * We used to take a refcount on sk, but following operation
2104 	 * is enough to guarantee sk_free() wont free this sock until
2105 	 * all in-flight packets are completed
2106 	 */
2107 	refcount_add(skb->truesize, &sk->sk_wmem_alloc);
2108 }
2109 EXPORT_SYMBOL(skb_set_owner_w);
2110 
2111 static bool can_skb_orphan_partial(const struct sk_buff *skb)
2112 {
2113 #ifdef CONFIG_TLS_DEVICE
2114 	/* Drivers depend on in-order delivery for crypto offload,
2115 	 * partial orphan breaks out-of-order-OK logic.
2116 	 */
2117 	if (skb->decrypted)
2118 		return false;
2119 #endif
2120 	return (skb->destructor == sock_wfree ||
2121 		(IS_ENABLED(CONFIG_INET) && skb->destructor == tcp_wfree));
2122 }
2123 
2124 /* This helper is used by netem, as it can hold packets in its
2125  * delay queue. We want to allow the owner socket to send more
2126  * packets, as if they were already TX completed by a typical driver.
2127  * But we also want to keep skb->sk set because some packet schedulers
2128  * rely on it (sch_fq for example).
2129  */
2130 void skb_orphan_partial(struct sk_buff *skb)
2131 {
2132 	if (skb_is_tcp_pure_ack(skb))
2133 		return;
2134 
2135 	if (can_skb_orphan_partial(skb))
2136 		skb_set_owner_sk_safe(skb, skb->sk);
2137 	else
2138 		skb_orphan(skb);
2139 }
2140 EXPORT_SYMBOL(skb_orphan_partial);
2141 
2142 /*
2143  * Read buffer destructor automatically called from kfree_skb.
2144  */
2145 void sock_rfree(struct sk_buff *skb)
2146 {
2147 	struct sock *sk = skb->sk;
2148 	unsigned int len = skb->truesize;
2149 
2150 	atomic_sub(len, &sk->sk_rmem_alloc);
2151 	sk_mem_uncharge(sk, len);
2152 }
2153 EXPORT_SYMBOL(sock_rfree);
2154 
2155 /*
2156  * Buffer destructor for skbs that are not used directly in read or write
2157  * path, e.g. for error handler skbs. Automatically called from kfree_skb.
2158  */
2159 void sock_efree(struct sk_buff *skb)
2160 {
2161 	sock_put(skb->sk);
2162 }
2163 EXPORT_SYMBOL(sock_efree);
2164 
2165 /* Buffer destructor for prefetch/receive path where reference count may
2166  * not be held, e.g. for listen sockets.
2167  */
2168 #ifdef CONFIG_INET
2169 void sock_pfree(struct sk_buff *skb)
2170 {
2171 	if (sk_is_refcounted(skb->sk))
2172 		sock_gen_put(skb->sk);
2173 }
2174 EXPORT_SYMBOL(sock_pfree);
2175 #endif /* CONFIG_INET */
2176 
2177 kuid_t sock_i_uid(struct sock *sk)
2178 {
2179 	kuid_t uid;
2180 
2181 	read_lock_bh(&sk->sk_callback_lock);
2182 	uid = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_uid : GLOBAL_ROOT_UID;
2183 	read_unlock_bh(&sk->sk_callback_lock);
2184 	return uid;
2185 }
2186 EXPORT_SYMBOL(sock_i_uid);
2187 
2188 unsigned long sock_i_ino(struct sock *sk)
2189 {
2190 	unsigned long ino;
2191 
2192 	read_lock_bh(&sk->sk_callback_lock);
2193 	ino = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_ino : 0;
2194 	read_unlock_bh(&sk->sk_callback_lock);
2195 	return ino;
2196 }
2197 EXPORT_SYMBOL(sock_i_ino);
2198 
2199 /*
2200  * Allocate a skb from the socket's send buffer.
2201  */
2202 struct sk_buff *sock_wmalloc(struct sock *sk, unsigned long size, int force,
2203 			     gfp_t priority)
2204 {
2205 	if (force ||
2206 	    refcount_read(&sk->sk_wmem_alloc) < READ_ONCE(sk->sk_sndbuf)) {
2207 		struct sk_buff *skb = alloc_skb(size, priority);
2208 
2209 		if (skb) {
2210 			skb_set_owner_w(skb, sk);
2211 			return skb;
2212 		}
2213 	}
2214 	return NULL;
2215 }
2216 EXPORT_SYMBOL(sock_wmalloc);
2217 
2218 static void sock_ofree(struct sk_buff *skb)
2219 {
2220 	struct sock *sk = skb->sk;
2221 
2222 	atomic_sub(skb->truesize, &sk->sk_omem_alloc);
2223 }
2224 
2225 struct sk_buff *sock_omalloc(struct sock *sk, unsigned long size,
2226 			     gfp_t priority)
2227 {
2228 	struct sk_buff *skb;
2229 
2230 	/* small safe race: SKB_TRUESIZE may differ from final skb->truesize */
2231 	if (atomic_read(&sk->sk_omem_alloc) + SKB_TRUESIZE(size) >
2232 	    sysctl_optmem_max)
2233 		return NULL;
2234 
2235 	skb = alloc_skb(size, priority);
2236 	if (!skb)
2237 		return NULL;
2238 
2239 	atomic_add(skb->truesize, &sk->sk_omem_alloc);
2240 	skb->sk = sk;
2241 	skb->destructor = sock_ofree;
2242 	return skb;
2243 }
2244 
2245 /*
2246  * Allocate a memory block from the socket's option memory buffer.
2247  */
2248 void *sock_kmalloc(struct sock *sk, int size, gfp_t priority)
2249 {
2250 	if ((unsigned int)size <= sysctl_optmem_max &&
2251 	    atomic_read(&sk->sk_omem_alloc) + size < sysctl_optmem_max) {
2252 		void *mem;
2253 		/* First do the add, to avoid the race if kmalloc
2254 		 * might sleep.
2255 		 */
2256 		atomic_add(size, &sk->sk_omem_alloc);
2257 		mem = kmalloc(size, priority);
2258 		if (mem)
2259 			return mem;
2260 		atomic_sub(size, &sk->sk_omem_alloc);
2261 	}
2262 	return NULL;
2263 }
2264 EXPORT_SYMBOL(sock_kmalloc);
2265 
2266 /* Free an option memory block. Note, we actually want the inline
2267  * here as this allows gcc to detect the nullify and fold away the
2268  * condition entirely.
2269  */
2270 static inline void __sock_kfree_s(struct sock *sk, void *mem, int size,
2271 				  const bool nullify)
2272 {
2273 	if (WARN_ON_ONCE(!mem))
2274 		return;
2275 	if (nullify)
2276 		kfree_sensitive(mem);
2277 	else
2278 		kfree(mem);
2279 	atomic_sub(size, &sk->sk_omem_alloc);
2280 }
2281 
2282 void sock_kfree_s(struct sock *sk, void *mem, int size)
2283 {
2284 	__sock_kfree_s(sk, mem, size, false);
2285 }
2286 EXPORT_SYMBOL(sock_kfree_s);
2287 
2288 void sock_kzfree_s(struct sock *sk, void *mem, int size)
2289 {
2290 	__sock_kfree_s(sk, mem, size, true);
2291 }
2292 EXPORT_SYMBOL(sock_kzfree_s);
2293 
2294 /* It is almost wait_for_tcp_memory minus release_sock/lock_sock.
2295    I think, these locks should be removed for datagram sockets.
2296  */
2297 static long sock_wait_for_wmem(struct sock *sk, long timeo)
2298 {
2299 	DEFINE_WAIT(wait);
2300 
2301 	sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
2302 	for (;;) {
2303 		if (!timeo)
2304 			break;
2305 		if (signal_pending(current))
2306 			break;
2307 		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
2308 		prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
2309 		if (refcount_read(&sk->sk_wmem_alloc) < READ_ONCE(sk->sk_sndbuf))
2310 			break;
2311 		if (sk->sk_shutdown & SEND_SHUTDOWN)
2312 			break;
2313 		if (sk->sk_err)
2314 			break;
2315 		timeo = schedule_timeout(timeo);
2316 	}
2317 	finish_wait(sk_sleep(sk), &wait);
2318 	return timeo;
2319 }
2320 
2321 
2322 /*
2323  *	Generic send/receive buffer handlers
2324  */
2325 
2326 struct sk_buff *sock_alloc_send_pskb(struct sock *sk, unsigned long header_len,
2327 				     unsigned long data_len, int noblock,
2328 				     int *errcode, int max_page_order)
2329 {
2330 	struct sk_buff *skb;
2331 	long timeo;
2332 	int err;
2333 
2334 	timeo = sock_sndtimeo(sk, noblock);
2335 	for (;;) {
2336 		err = sock_error(sk);
2337 		if (err != 0)
2338 			goto failure;
2339 
2340 		err = -EPIPE;
2341 		if (sk->sk_shutdown & SEND_SHUTDOWN)
2342 			goto failure;
2343 
2344 		if (sk_wmem_alloc_get(sk) < READ_ONCE(sk->sk_sndbuf))
2345 			break;
2346 
2347 		sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
2348 		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
2349 		err = -EAGAIN;
2350 		if (!timeo)
2351 			goto failure;
2352 		if (signal_pending(current))
2353 			goto interrupted;
2354 		timeo = sock_wait_for_wmem(sk, timeo);
2355 	}
2356 	skb = alloc_skb_with_frags(header_len, data_len, max_page_order,
2357 				   errcode, sk->sk_allocation);
2358 	if (skb)
2359 		skb_set_owner_w(skb, sk);
2360 	return skb;
2361 
2362 interrupted:
2363 	err = sock_intr_errno(timeo);
2364 failure:
2365 	*errcode = err;
2366 	return NULL;
2367 }
2368 EXPORT_SYMBOL(sock_alloc_send_pskb);
2369 
2370 struct sk_buff *sock_alloc_send_skb(struct sock *sk, unsigned long size,
2371 				    int noblock, int *errcode)
2372 {
2373 	return sock_alloc_send_pskb(sk, size, 0, noblock, errcode, 0);
2374 }
2375 EXPORT_SYMBOL(sock_alloc_send_skb);
2376 
2377 int __sock_cmsg_send(struct sock *sk, struct msghdr *msg, struct cmsghdr *cmsg,
2378 		     struct sockcm_cookie *sockc)
2379 {
2380 	u32 tsflags;
2381 
2382 	switch (cmsg->cmsg_type) {
2383 	case SO_MARK:
2384 		if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
2385 			return -EPERM;
2386 		if (cmsg->cmsg_len != CMSG_LEN(sizeof(u32)))
2387 			return -EINVAL;
2388 		sockc->mark = *(u32 *)CMSG_DATA(cmsg);
2389 		break;
2390 	case SO_TIMESTAMPING_OLD:
2391 		if (cmsg->cmsg_len != CMSG_LEN(sizeof(u32)))
2392 			return -EINVAL;
2393 
2394 		tsflags = *(u32 *)CMSG_DATA(cmsg);
2395 		if (tsflags & ~SOF_TIMESTAMPING_TX_RECORD_MASK)
2396 			return -EINVAL;
2397 
2398 		sockc->tsflags &= ~SOF_TIMESTAMPING_TX_RECORD_MASK;
2399 		sockc->tsflags |= tsflags;
2400 		break;
2401 	case SCM_TXTIME:
2402 		if (!sock_flag(sk, SOCK_TXTIME))
2403 			return -EINVAL;
2404 		if (cmsg->cmsg_len != CMSG_LEN(sizeof(u64)))
2405 			return -EINVAL;
2406 		sockc->transmit_time = get_unaligned((u64 *)CMSG_DATA(cmsg));
2407 		break;
2408 	/* SCM_RIGHTS and SCM_CREDENTIALS are semantically in SOL_UNIX. */
2409 	case SCM_RIGHTS:
2410 	case SCM_CREDENTIALS:
2411 		break;
2412 	default:
2413 		return -EINVAL;
2414 	}
2415 	return 0;
2416 }
2417 EXPORT_SYMBOL(__sock_cmsg_send);
2418 
2419 int sock_cmsg_send(struct sock *sk, struct msghdr *msg,
2420 		   struct sockcm_cookie *sockc)
2421 {
2422 	struct cmsghdr *cmsg;
2423 	int ret;
2424 
2425 	for_each_cmsghdr(cmsg, msg) {
2426 		if (!CMSG_OK(msg, cmsg))
2427 			return -EINVAL;
2428 		if (cmsg->cmsg_level != SOL_SOCKET)
2429 			continue;
2430 		ret = __sock_cmsg_send(sk, msg, cmsg, sockc);
2431 		if (ret)
2432 			return ret;
2433 	}
2434 	return 0;
2435 }
2436 EXPORT_SYMBOL(sock_cmsg_send);
2437 
2438 static void sk_enter_memory_pressure(struct sock *sk)
2439 {
2440 	if (!sk->sk_prot->enter_memory_pressure)
2441 		return;
2442 
2443 	sk->sk_prot->enter_memory_pressure(sk);
2444 }
2445 
2446 static void sk_leave_memory_pressure(struct sock *sk)
2447 {
2448 	if (sk->sk_prot->leave_memory_pressure) {
2449 		sk->sk_prot->leave_memory_pressure(sk);
2450 	} else {
2451 		unsigned long *memory_pressure = sk->sk_prot->memory_pressure;
2452 
2453 		if (memory_pressure && READ_ONCE(*memory_pressure))
2454 			WRITE_ONCE(*memory_pressure, 0);
2455 	}
2456 }
2457 
2458 #define SKB_FRAG_PAGE_ORDER	get_order(32768)
2459 DEFINE_STATIC_KEY_FALSE(net_high_order_alloc_disable_key);
2460 
2461 /**
2462  * skb_page_frag_refill - check that a page_frag contains enough room
2463  * @sz: minimum size of the fragment we want to get
2464  * @pfrag: pointer to page_frag
2465  * @gfp: priority for memory allocation
2466  *
2467  * Note: While this allocator tries to use high order pages, there is
2468  * no guarantee that allocations succeed. Therefore, @sz MUST be
2469  * less or equal than PAGE_SIZE.
2470  */
2471 bool skb_page_frag_refill(unsigned int sz, struct page_frag *pfrag, gfp_t gfp)
2472 {
2473 	if (pfrag->page) {
2474 		if (page_ref_count(pfrag->page) == 1) {
2475 			pfrag->offset = 0;
2476 			return true;
2477 		}
2478 		if (pfrag->offset + sz <= pfrag->size)
2479 			return true;
2480 		put_page(pfrag->page);
2481 	}
2482 
2483 	pfrag->offset = 0;
2484 	if (SKB_FRAG_PAGE_ORDER &&
2485 	    !static_branch_unlikely(&net_high_order_alloc_disable_key)) {
2486 		/* Avoid direct reclaim but allow kswapd to wake */
2487 		pfrag->page = alloc_pages((gfp & ~__GFP_DIRECT_RECLAIM) |
2488 					  __GFP_COMP | __GFP_NOWARN |
2489 					  __GFP_NORETRY,
2490 					  SKB_FRAG_PAGE_ORDER);
2491 		if (likely(pfrag->page)) {
2492 			pfrag->size = PAGE_SIZE << SKB_FRAG_PAGE_ORDER;
2493 			return true;
2494 		}
2495 	}
2496 	pfrag->page = alloc_page(gfp);
2497 	if (likely(pfrag->page)) {
2498 		pfrag->size = PAGE_SIZE;
2499 		return true;
2500 	}
2501 	return false;
2502 }
2503 EXPORT_SYMBOL(skb_page_frag_refill);
2504 
2505 bool sk_page_frag_refill(struct sock *sk, struct page_frag *pfrag)
2506 {
2507 	if (likely(skb_page_frag_refill(32U, pfrag, sk->sk_allocation)))
2508 		return true;
2509 
2510 	sk_enter_memory_pressure(sk);
2511 	sk_stream_moderate_sndbuf(sk);
2512 	return false;
2513 }
2514 EXPORT_SYMBOL(sk_page_frag_refill);
2515 
2516 void __lock_sock(struct sock *sk)
2517 	__releases(&sk->sk_lock.slock)
2518 	__acquires(&sk->sk_lock.slock)
2519 {
2520 	DEFINE_WAIT(wait);
2521 
2522 	for (;;) {
2523 		prepare_to_wait_exclusive(&sk->sk_lock.wq, &wait,
2524 					TASK_UNINTERRUPTIBLE);
2525 		spin_unlock_bh(&sk->sk_lock.slock);
2526 		schedule();
2527 		spin_lock_bh(&sk->sk_lock.slock);
2528 		if (!sock_owned_by_user(sk))
2529 			break;
2530 	}
2531 	finish_wait(&sk->sk_lock.wq, &wait);
2532 }
2533 
2534 void __release_sock(struct sock *sk)
2535 	__releases(&sk->sk_lock.slock)
2536 	__acquires(&sk->sk_lock.slock)
2537 {
2538 	struct sk_buff *skb, *next;
2539 
2540 	while ((skb = sk->sk_backlog.head) != NULL) {
2541 		sk->sk_backlog.head = sk->sk_backlog.tail = NULL;
2542 
2543 		spin_unlock_bh(&sk->sk_lock.slock);
2544 
2545 		do {
2546 			next = skb->next;
2547 			prefetch(next);
2548 			WARN_ON_ONCE(skb_dst_is_noref(skb));
2549 			skb_mark_not_on_list(skb);
2550 			sk_backlog_rcv(sk, skb);
2551 
2552 			cond_resched();
2553 
2554 			skb = next;
2555 		} while (skb != NULL);
2556 
2557 		spin_lock_bh(&sk->sk_lock.slock);
2558 	}
2559 
2560 	/*
2561 	 * Doing the zeroing here guarantee we can not loop forever
2562 	 * while a wild producer attempts to flood us.
2563 	 */
2564 	sk->sk_backlog.len = 0;
2565 }
2566 
2567 void __sk_flush_backlog(struct sock *sk)
2568 {
2569 	spin_lock_bh(&sk->sk_lock.slock);
2570 	__release_sock(sk);
2571 	spin_unlock_bh(&sk->sk_lock.slock);
2572 }
2573 
2574 /**
2575  * sk_wait_data - wait for data to arrive at sk_receive_queue
2576  * @sk:    sock to wait on
2577  * @timeo: for how long
2578  * @skb:   last skb seen on sk_receive_queue
2579  *
2580  * Now socket state including sk->sk_err is changed only under lock,
2581  * hence we may omit checks after joining wait queue.
2582  * We check receive queue before schedule() only as optimization;
2583  * it is very likely that release_sock() added new data.
2584  */
2585 int sk_wait_data(struct sock *sk, long *timeo, const struct sk_buff *skb)
2586 {
2587 	DEFINE_WAIT_FUNC(wait, woken_wake_function);
2588 	int rc;
2589 
2590 	add_wait_queue(sk_sleep(sk), &wait);
2591 	sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
2592 	rc = sk_wait_event(sk, timeo, skb_peek_tail(&sk->sk_receive_queue) != skb, &wait);
2593 	sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
2594 	remove_wait_queue(sk_sleep(sk), &wait);
2595 	return rc;
2596 }
2597 EXPORT_SYMBOL(sk_wait_data);
2598 
2599 /**
2600  *	__sk_mem_raise_allocated - increase memory_allocated
2601  *	@sk: socket
2602  *	@size: memory size to allocate
2603  *	@amt: pages to allocate
2604  *	@kind: allocation type
2605  *
2606  *	Similar to __sk_mem_schedule(), but does not update sk_forward_alloc
2607  */
2608 int __sk_mem_raise_allocated(struct sock *sk, int size, int amt, int kind)
2609 {
2610 	struct proto *prot = sk->sk_prot;
2611 	long allocated = sk_memory_allocated_add(sk, amt);
2612 	bool charged = true;
2613 
2614 	if (mem_cgroup_sockets_enabled && sk->sk_memcg &&
2615 	    !(charged = mem_cgroup_charge_skmem(sk->sk_memcg, amt)))
2616 		goto suppress_allocation;
2617 
2618 	/* Under limit. */
2619 	if (allocated <= sk_prot_mem_limits(sk, 0)) {
2620 		sk_leave_memory_pressure(sk);
2621 		return 1;
2622 	}
2623 
2624 	/* Under pressure. */
2625 	if (allocated > sk_prot_mem_limits(sk, 1))
2626 		sk_enter_memory_pressure(sk);
2627 
2628 	/* Over hard limit. */
2629 	if (allocated > sk_prot_mem_limits(sk, 2))
2630 		goto suppress_allocation;
2631 
2632 	/* guarantee minimum buffer size under pressure */
2633 	if (kind == SK_MEM_RECV) {
2634 		if (atomic_read(&sk->sk_rmem_alloc) < sk_get_rmem0(sk, prot))
2635 			return 1;
2636 
2637 	} else { /* SK_MEM_SEND */
2638 		int wmem0 = sk_get_wmem0(sk, prot);
2639 
2640 		if (sk->sk_type == SOCK_STREAM) {
2641 			if (sk->sk_wmem_queued < wmem0)
2642 				return 1;
2643 		} else if (refcount_read(&sk->sk_wmem_alloc) < wmem0) {
2644 				return 1;
2645 		}
2646 	}
2647 
2648 	if (sk_has_memory_pressure(sk)) {
2649 		u64 alloc;
2650 
2651 		if (!sk_under_memory_pressure(sk))
2652 			return 1;
2653 		alloc = sk_sockets_allocated_read_positive(sk);
2654 		if (sk_prot_mem_limits(sk, 2) > alloc *
2655 		    sk_mem_pages(sk->sk_wmem_queued +
2656 				 atomic_read(&sk->sk_rmem_alloc) +
2657 				 sk->sk_forward_alloc))
2658 			return 1;
2659 	}
2660 
2661 suppress_allocation:
2662 
2663 	if (kind == SK_MEM_SEND && sk->sk_type == SOCK_STREAM) {
2664 		sk_stream_moderate_sndbuf(sk);
2665 
2666 		/* Fail only if socket is _under_ its sndbuf.
2667 		 * In this case we cannot block, so that we have to fail.
2668 		 */
2669 		if (sk->sk_wmem_queued + size >= sk->sk_sndbuf)
2670 			return 1;
2671 	}
2672 
2673 	if (kind == SK_MEM_SEND || (kind == SK_MEM_RECV && charged))
2674 		trace_sock_exceed_buf_limit(sk, prot, allocated, kind);
2675 
2676 	sk_memory_allocated_sub(sk, amt);
2677 
2678 	if (mem_cgroup_sockets_enabled && sk->sk_memcg)
2679 		mem_cgroup_uncharge_skmem(sk->sk_memcg, amt);
2680 
2681 	return 0;
2682 }
2683 EXPORT_SYMBOL(__sk_mem_raise_allocated);
2684 
2685 /**
2686  *	__sk_mem_schedule - increase sk_forward_alloc and memory_allocated
2687  *	@sk: socket
2688  *	@size: memory size to allocate
2689  *	@kind: allocation type
2690  *
2691  *	If kind is SK_MEM_SEND, it means wmem allocation. Otherwise it means
2692  *	rmem allocation. This function assumes that protocols which have
2693  *	memory_pressure use sk_wmem_queued as write buffer accounting.
2694  */
2695 int __sk_mem_schedule(struct sock *sk, int size, int kind)
2696 {
2697 	int ret, amt = sk_mem_pages(size);
2698 
2699 	sk->sk_forward_alloc += amt << SK_MEM_QUANTUM_SHIFT;
2700 	ret = __sk_mem_raise_allocated(sk, size, amt, kind);
2701 	if (!ret)
2702 		sk->sk_forward_alloc -= amt << SK_MEM_QUANTUM_SHIFT;
2703 	return ret;
2704 }
2705 EXPORT_SYMBOL(__sk_mem_schedule);
2706 
2707 /**
2708  *	__sk_mem_reduce_allocated - reclaim memory_allocated
2709  *	@sk: socket
2710  *	@amount: number of quanta
2711  *
2712  *	Similar to __sk_mem_reclaim(), but does not update sk_forward_alloc
2713  */
2714 void __sk_mem_reduce_allocated(struct sock *sk, int amount)
2715 {
2716 	sk_memory_allocated_sub(sk, amount);
2717 
2718 	if (mem_cgroup_sockets_enabled && sk->sk_memcg)
2719 		mem_cgroup_uncharge_skmem(sk->sk_memcg, amount);
2720 
2721 	if (sk_under_memory_pressure(sk) &&
2722 	    (sk_memory_allocated(sk) < sk_prot_mem_limits(sk, 0)))
2723 		sk_leave_memory_pressure(sk);
2724 }
2725 EXPORT_SYMBOL(__sk_mem_reduce_allocated);
2726 
2727 /**
2728  *	__sk_mem_reclaim - reclaim sk_forward_alloc and memory_allocated
2729  *	@sk: socket
2730  *	@amount: number of bytes (rounded down to a SK_MEM_QUANTUM multiple)
2731  */
2732 void __sk_mem_reclaim(struct sock *sk, int amount)
2733 {
2734 	amount >>= SK_MEM_QUANTUM_SHIFT;
2735 	sk->sk_forward_alloc -= amount << SK_MEM_QUANTUM_SHIFT;
2736 	__sk_mem_reduce_allocated(sk, amount);
2737 }
2738 EXPORT_SYMBOL(__sk_mem_reclaim);
2739 
2740 int sk_set_peek_off(struct sock *sk, int val)
2741 {
2742 	sk->sk_peek_off = val;
2743 	return 0;
2744 }
2745 EXPORT_SYMBOL_GPL(sk_set_peek_off);
2746 
2747 /*
2748  * Set of default routines for initialising struct proto_ops when
2749  * the protocol does not support a particular function. In certain
2750  * cases where it makes no sense for a protocol to have a "do nothing"
2751  * function, some default processing is provided.
2752  */
2753 
2754 int sock_no_bind(struct socket *sock, struct sockaddr *saddr, int len)
2755 {
2756 	return -EOPNOTSUPP;
2757 }
2758 EXPORT_SYMBOL(sock_no_bind);
2759 
2760 int sock_no_connect(struct socket *sock, struct sockaddr *saddr,
2761 		    int len, int flags)
2762 {
2763 	return -EOPNOTSUPP;
2764 }
2765 EXPORT_SYMBOL(sock_no_connect);
2766 
2767 int sock_no_socketpair(struct socket *sock1, struct socket *sock2)
2768 {
2769 	return -EOPNOTSUPP;
2770 }
2771 EXPORT_SYMBOL(sock_no_socketpair);
2772 
2773 int sock_no_accept(struct socket *sock, struct socket *newsock, int flags,
2774 		   bool kern)
2775 {
2776 	return -EOPNOTSUPP;
2777 }
2778 EXPORT_SYMBOL(sock_no_accept);
2779 
2780 int sock_no_getname(struct socket *sock, struct sockaddr *saddr,
2781 		    int peer)
2782 {
2783 	return -EOPNOTSUPP;
2784 }
2785 EXPORT_SYMBOL(sock_no_getname);
2786 
2787 int sock_no_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
2788 {
2789 	return -EOPNOTSUPP;
2790 }
2791 EXPORT_SYMBOL(sock_no_ioctl);
2792 
2793 int sock_no_listen(struct socket *sock, int backlog)
2794 {
2795 	return -EOPNOTSUPP;
2796 }
2797 EXPORT_SYMBOL(sock_no_listen);
2798 
2799 int sock_no_shutdown(struct socket *sock, int how)
2800 {
2801 	return -EOPNOTSUPP;
2802 }
2803 EXPORT_SYMBOL(sock_no_shutdown);
2804 
2805 int sock_no_sendmsg(struct socket *sock, struct msghdr *m, size_t len)
2806 {
2807 	return -EOPNOTSUPP;
2808 }
2809 EXPORT_SYMBOL(sock_no_sendmsg);
2810 
2811 int sock_no_sendmsg_locked(struct sock *sk, struct msghdr *m, size_t len)
2812 {
2813 	return -EOPNOTSUPP;
2814 }
2815 EXPORT_SYMBOL(sock_no_sendmsg_locked);
2816 
2817 int sock_no_recvmsg(struct socket *sock, struct msghdr *m, size_t len,
2818 		    int flags)
2819 {
2820 	return -EOPNOTSUPP;
2821 }
2822 EXPORT_SYMBOL(sock_no_recvmsg);
2823 
2824 int sock_no_mmap(struct file *file, struct socket *sock, struct vm_area_struct *vma)
2825 {
2826 	/* Mirror missing mmap method error code */
2827 	return -ENODEV;
2828 }
2829 EXPORT_SYMBOL(sock_no_mmap);
2830 
2831 /*
2832  * When a file is received (via SCM_RIGHTS, etc), we must bump the
2833  * various sock-based usage counts.
2834  */
2835 void __receive_sock(struct file *file)
2836 {
2837 	struct socket *sock;
2838 
2839 	sock = sock_from_file(file);
2840 	if (sock) {
2841 		sock_update_netprioidx(&sock->sk->sk_cgrp_data);
2842 		sock_update_classid(&sock->sk->sk_cgrp_data);
2843 	}
2844 }
2845 
2846 ssize_t sock_no_sendpage(struct socket *sock, struct page *page, int offset, size_t size, int flags)
2847 {
2848 	ssize_t res;
2849 	struct msghdr msg = {.msg_flags = flags};
2850 	struct kvec iov;
2851 	char *kaddr = kmap(page);
2852 	iov.iov_base = kaddr + offset;
2853 	iov.iov_len = size;
2854 	res = kernel_sendmsg(sock, &msg, &iov, 1, size);
2855 	kunmap(page);
2856 	return res;
2857 }
2858 EXPORT_SYMBOL(sock_no_sendpage);
2859 
2860 ssize_t sock_no_sendpage_locked(struct sock *sk, struct page *page,
2861 				int offset, size_t size, int flags)
2862 {
2863 	ssize_t res;
2864 	struct msghdr msg = {.msg_flags = flags};
2865 	struct kvec iov;
2866 	char *kaddr = kmap(page);
2867 
2868 	iov.iov_base = kaddr + offset;
2869 	iov.iov_len = size;
2870 	res = kernel_sendmsg_locked(sk, &msg, &iov, 1, size);
2871 	kunmap(page);
2872 	return res;
2873 }
2874 EXPORT_SYMBOL(sock_no_sendpage_locked);
2875 
2876 /*
2877  *	Default Socket Callbacks
2878  */
2879 
2880 static void sock_def_wakeup(struct sock *sk)
2881 {
2882 	struct socket_wq *wq;
2883 
2884 	rcu_read_lock();
2885 	wq = rcu_dereference(sk->sk_wq);
2886 	if (skwq_has_sleeper(wq))
2887 		wake_up_interruptible_all(&wq->wait);
2888 	rcu_read_unlock();
2889 }
2890 
2891 static void sock_def_error_report(struct sock *sk)
2892 {
2893 	struct socket_wq *wq;
2894 
2895 	rcu_read_lock();
2896 	wq = rcu_dereference(sk->sk_wq);
2897 	if (skwq_has_sleeper(wq))
2898 		wake_up_interruptible_poll(&wq->wait, EPOLLERR);
2899 	sk_wake_async(sk, SOCK_WAKE_IO, POLL_ERR);
2900 	rcu_read_unlock();
2901 }
2902 
2903 void sock_def_readable(struct sock *sk)
2904 {
2905 	struct socket_wq *wq;
2906 
2907 	rcu_read_lock();
2908 	wq = rcu_dereference(sk->sk_wq);
2909 	if (skwq_has_sleeper(wq))
2910 		wake_up_interruptible_sync_poll(&wq->wait, EPOLLIN | EPOLLPRI |
2911 						EPOLLRDNORM | EPOLLRDBAND);
2912 	sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
2913 	rcu_read_unlock();
2914 }
2915 
2916 static void sock_def_write_space(struct sock *sk)
2917 {
2918 	struct socket_wq *wq;
2919 
2920 	rcu_read_lock();
2921 
2922 	/* Do not wake up a writer until he can make "significant"
2923 	 * progress.  --DaveM
2924 	 */
2925 	if ((refcount_read(&sk->sk_wmem_alloc) << 1) <= READ_ONCE(sk->sk_sndbuf)) {
2926 		wq = rcu_dereference(sk->sk_wq);
2927 		if (skwq_has_sleeper(wq))
2928 			wake_up_interruptible_sync_poll(&wq->wait, EPOLLOUT |
2929 						EPOLLWRNORM | EPOLLWRBAND);
2930 
2931 		/* Should agree with poll, otherwise some programs break */
2932 		if (sock_writeable(sk))
2933 			sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
2934 	}
2935 
2936 	rcu_read_unlock();
2937 }
2938 
2939 static void sock_def_destruct(struct sock *sk)
2940 {
2941 }
2942 
2943 void sk_send_sigurg(struct sock *sk)
2944 {
2945 	if (sk->sk_socket && sk->sk_socket->file)
2946 		if (send_sigurg(&sk->sk_socket->file->f_owner))
2947 			sk_wake_async(sk, SOCK_WAKE_URG, POLL_PRI);
2948 }
2949 EXPORT_SYMBOL(sk_send_sigurg);
2950 
2951 void sk_reset_timer(struct sock *sk, struct timer_list* timer,
2952 		    unsigned long expires)
2953 {
2954 	if (!mod_timer(timer, expires))
2955 		sock_hold(sk);
2956 }
2957 EXPORT_SYMBOL(sk_reset_timer);
2958 
2959 void sk_stop_timer(struct sock *sk, struct timer_list* timer)
2960 {
2961 	if (del_timer(timer))
2962 		__sock_put(sk);
2963 }
2964 EXPORT_SYMBOL(sk_stop_timer);
2965 
2966 void sk_stop_timer_sync(struct sock *sk, struct timer_list *timer)
2967 {
2968 	if (del_timer_sync(timer))
2969 		__sock_put(sk);
2970 }
2971 EXPORT_SYMBOL(sk_stop_timer_sync);
2972 
2973 void sock_init_data(struct socket *sock, struct sock *sk)
2974 {
2975 	sk_init_common(sk);
2976 	sk->sk_send_head	=	NULL;
2977 
2978 	timer_setup(&sk->sk_timer, NULL, 0);
2979 
2980 	sk->sk_allocation	=	GFP_KERNEL;
2981 	sk->sk_rcvbuf		=	sysctl_rmem_default;
2982 	sk->sk_sndbuf		=	sysctl_wmem_default;
2983 	sk->sk_state		=	TCP_CLOSE;
2984 	sk_set_socket(sk, sock);
2985 
2986 	sock_set_flag(sk, SOCK_ZAPPED);
2987 
2988 	if (sock) {
2989 		sk->sk_type	=	sock->type;
2990 		RCU_INIT_POINTER(sk->sk_wq, &sock->wq);
2991 		sock->sk	=	sk;
2992 		sk->sk_uid	=	SOCK_INODE(sock)->i_uid;
2993 	} else {
2994 		RCU_INIT_POINTER(sk->sk_wq, NULL);
2995 		sk->sk_uid	=	make_kuid(sock_net(sk)->user_ns, 0);
2996 	}
2997 
2998 	rwlock_init(&sk->sk_callback_lock);
2999 	if (sk->sk_kern_sock)
3000 		lockdep_set_class_and_name(
3001 			&sk->sk_callback_lock,
3002 			af_kern_callback_keys + sk->sk_family,
3003 			af_family_kern_clock_key_strings[sk->sk_family]);
3004 	else
3005 		lockdep_set_class_and_name(
3006 			&sk->sk_callback_lock,
3007 			af_callback_keys + sk->sk_family,
3008 			af_family_clock_key_strings[sk->sk_family]);
3009 
3010 	sk->sk_state_change	=	sock_def_wakeup;
3011 	sk->sk_data_ready	=	sock_def_readable;
3012 	sk->sk_write_space	=	sock_def_write_space;
3013 	sk->sk_error_report	=	sock_def_error_report;
3014 	sk->sk_destruct		=	sock_def_destruct;
3015 
3016 	sk->sk_frag.page	=	NULL;
3017 	sk->sk_frag.offset	=	0;
3018 	sk->sk_peek_off		=	-1;
3019 
3020 	sk->sk_peer_pid 	=	NULL;
3021 	sk->sk_peer_cred	=	NULL;
3022 	sk->sk_write_pending	=	0;
3023 	sk->sk_rcvlowat		=	1;
3024 	sk->sk_rcvtimeo		=	MAX_SCHEDULE_TIMEOUT;
3025 	sk->sk_sndtimeo		=	MAX_SCHEDULE_TIMEOUT;
3026 
3027 	sk->sk_stamp = SK_DEFAULT_STAMP;
3028 #if BITS_PER_LONG==32
3029 	seqlock_init(&sk->sk_stamp_seq);
3030 #endif
3031 	atomic_set(&sk->sk_zckey, 0);
3032 
3033 #ifdef CONFIG_NET_RX_BUSY_POLL
3034 	sk->sk_napi_id		=	0;
3035 	sk->sk_ll_usec		=	sysctl_net_busy_read;
3036 #endif
3037 
3038 	sk->sk_max_pacing_rate = ~0UL;
3039 	sk->sk_pacing_rate = ~0UL;
3040 	WRITE_ONCE(sk->sk_pacing_shift, 10);
3041 	sk->sk_incoming_cpu = -1;
3042 
3043 	sk_rx_queue_clear(sk);
3044 	/*
3045 	 * Before updating sk_refcnt, we must commit prior changes to memory
3046 	 * (Documentation/RCU/rculist_nulls.rst for details)
3047 	 */
3048 	smp_wmb();
3049 	refcount_set(&sk->sk_refcnt, 1);
3050 	atomic_set(&sk->sk_drops, 0);
3051 }
3052 EXPORT_SYMBOL(sock_init_data);
3053 
3054 void lock_sock_nested(struct sock *sk, int subclass)
3055 {
3056 	might_sleep();
3057 	spin_lock_bh(&sk->sk_lock.slock);
3058 	if (sk->sk_lock.owned)
3059 		__lock_sock(sk);
3060 	sk->sk_lock.owned = 1;
3061 	spin_unlock(&sk->sk_lock.slock);
3062 	/*
3063 	 * The sk_lock has mutex_lock() semantics here:
3064 	 */
3065 	mutex_acquire(&sk->sk_lock.dep_map, subclass, 0, _RET_IP_);
3066 	local_bh_enable();
3067 }
3068 EXPORT_SYMBOL(lock_sock_nested);
3069 
3070 void release_sock(struct sock *sk)
3071 {
3072 	spin_lock_bh(&sk->sk_lock.slock);
3073 	if (sk->sk_backlog.tail)
3074 		__release_sock(sk);
3075 
3076 	/* Warning : release_cb() might need to release sk ownership,
3077 	 * ie call sock_release_ownership(sk) before us.
3078 	 */
3079 	if (sk->sk_prot->release_cb)
3080 		sk->sk_prot->release_cb(sk);
3081 
3082 	sock_release_ownership(sk);
3083 	if (waitqueue_active(&sk->sk_lock.wq))
3084 		wake_up(&sk->sk_lock.wq);
3085 	spin_unlock_bh(&sk->sk_lock.slock);
3086 }
3087 EXPORT_SYMBOL(release_sock);
3088 
3089 /**
3090  * lock_sock_fast - fast version of lock_sock
3091  * @sk: socket
3092  *
3093  * This version should be used for very small section, where process wont block
3094  * return false if fast path is taken:
3095  *
3096  *   sk_lock.slock locked, owned = 0, BH disabled
3097  *
3098  * return true if slow path is taken:
3099  *
3100  *   sk_lock.slock unlocked, owned = 1, BH enabled
3101  */
3102 bool lock_sock_fast(struct sock *sk) __acquires(&sk->sk_lock.slock)
3103 {
3104 	might_sleep();
3105 	spin_lock_bh(&sk->sk_lock.slock);
3106 
3107 	if (!sk->sk_lock.owned)
3108 		/*
3109 		 * Note : We must disable BH
3110 		 */
3111 		return false;
3112 
3113 	__lock_sock(sk);
3114 	sk->sk_lock.owned = 1;
3115 	spin_unlock(&sk->sk_lock.slock);
3116 	/*
3117 	 * The sk_lock has mutex_lock() semantics here:
3118 	 */
3119 	mutex_acquire(&sk->sk_lock.dep_map, 0, 0, _RET_IP_);
3120 	__acquire(&sk->sk_lock.slock);
3121 	local_bh_enable();
3122 	return true;
3123 }
3124 EXPORT_SYMBOL(lock_sock_fast);
3125 
3126 int sock_gettstamp(struct socket *sock, void __user *userstamp,
3127 		   bool timeval, bool time32)
3128 {
3129 	struct sock *sk = sock->sk;
3130 	struct timespec64 ts;
3131 
3132 	sock_enable_timestamp(sk, SOCK_TIMESTAMP);
3133 	ts = ktime_to_timespec64(sock_read_timestamp(sk));
3134 	if (ts.tv_sec == -1)
3135 		return -ENOENT;
3136 	if (ts.tv_sec == 0) {
3137 		ktime_t kt = ktime_get_real();
3138 		sock_write_timestamp(sk, kt);
3139 		ts = ktime_to_timespec64(kt);
3140 	}
3141 
3142 	if (timeval)
3143 		ts.tv_nsec /= 1000;
3144 
3145 #ifdef CONFIG_COMPAT_32BIT_TIME
3146 	if (time32)
3147 		return put_old_timespec32(&ts, userstamp);
3148 #endif
3149 #ifdef CONFIG_SPARC64
3150 	/* beware of padding in sparc64 timeval */
3151 	if (timeval && !in_compat_syscall()) {
3152 		struct __kernel_old_timeval __user tv = {
3153 			.tv_sec = ts.tv_sec,
3154 			.tv_usec = ts.tv_nsec,
3155 		};
3156 		if (copy_to_user(userstamp, &tv, sizeof(tv)))
3157 			return -EFAULT;
3158 		return 0;
3159 	}
3160 #endif
3161 	return put_timespec64(&ts, userstamp);
3162 }
3163 EXPORT_SYMBOL(sock_gettstamp);
3164 
3165 void sock_enable_timestamp(struct sock *sk, enum sock_flags flag)
3166 {
3167 	if (!sock_flag(sk, flag)) {
3168 		unsigned long previous_flags = sk->sk_flags;
3169 
3170 		sock_set_flag(sk, flag);
3171 		/*
3172 		 * we just set one of the two flags which require net
3173 		 * time stamping, but time stamping might have been on
3174 		 * already because of the other one
3175 		 */
3176 		if (sock_needs_netstamp(sk) &&
3177 		    !(previous_flags & SK_FLAGS_TIMESTAMP))
3178 			net_enable_timestamp();
3179 	}
3180 }
3181 
3182 int sock_recv_errqueue(struct sock *sk, struct msghdr *msg, int len,
3183 		       int level, int type)
3184 {
3185 	struct sock_exterr_skb *serr;
3186 	struct sk_buff *skb;
3187 	int copied, err;
3188 
3189 	err = -EAGAIN;
3190 	skb = sock_dequeue_err_skb(sk);
3191 	if (skb == NULL)
3192 		goto out;
3193 
3194 	copied = skb->len;
3195 	if (copied > len) {
3196 		msg->msg_flags |= MSG_TRUNC;
3197 		copied = len;
3198 	}
3199 	err = skb_copy_datagram_msg(skb, 0, msg, copied);
3200 	if (err)
3201 		goto out_free_skb;
3202 
3203 	sock_recv_timestamp(msg, sk, skb);
3204 
3205 	serr = SKB_EXT_ERR(skb);
3206 	put_cmsg(msg, level, type, sizeof(serr->ee), &serr->ee);
3207 
3208 	msg->msg_flags |= MSG_ERRQUEUE;
3209 	err = copied;
3210 
3211 out_free_skb:
3212 	kfree_skb(skb);
3213 out:
3214 	return err;
3215 }
3216 EXPORT_SYMBOL(sock_recv_errqueue);
3217 
3218 /*
3219  *	Get a socket option on an socket.
3220  *
3221  *	FIX: POSIX 1003.1g is very ambiguous here. It states that
3222  *	asynchronous errors should be reported by getsockopt. We assume
3223  *	this means if you specify SO_ERROR (otherwise whats the point of it).
3224  */
3225 int sock_common_getsockopt(struct socket *sock, int level, int optname,
3226 			   char __user *optval, int __user *optlen)
3227 {
3228 	struct sock *sk = sock->sk;
3229 
3230 	return sk->sk_prot->getsockopt(sk, level, optname, optval, optlen);
3231 }
3232 EXPORT_SYMBOL(sock_common_getsockopt);
3233 
3234 int sock_common_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
3235 			int flags)
3236 {
3237 	struct sock *sk = sock->sk;
3238 	int addr_len = 0;
3239 	int err;
3240 
3241 	err = sk->sk_prot->recvmsg(sk, msg, size, flags & MSG_DONTWAIT,
3242 				   flags & ~MSG_DONTWAIT, &addr_len);
3243 	if (err >= 0)
3244 		msg->msg_namelen = addr_len;
3245 	return err;
3246 }
3247 EXPORT_SYMBOL(sock_common_recvmsg);
3248 
3249 /*
3250  *	Set socket options on an inet socket.
3251  */
3252 int sock_common_setsockopt(struct socket *sock, int level, int optname,
3253 			   sockptr_t optval, unsigned int optlen)
3254 {
3255 	struct sock *sk = sock->sk;
3256 
3257 	return sk->sk_prot->setsockopt(sk, level, optname, optval, optlen);
3258 }
3259 EXPORT_SYMBOL(sock_common_setsockopt);
3260 
3261 void sk_common_release(struct sock *sk)
3262 {
3263 	if (sk->sk_prot->destroy)
3264 		sk->sk_prot->destroy(sk);
3265 
3266 	/*
3267 	 * Observation: when sk_common_release is called, processes have
3268 	 * no access to socket. But net still has.
3269 	 * Step one, detach it from networking:
3270 	 *
3271 	 * A. Remove from hash tables.
3272 	 */
3273 
3274 	sk->sk_prot->unhash(sk);
3275 
3276 	/*
3277 	 * In this point socket cannot receive new packets, but it is possible
3278 	 * that some packets are in flight because some CPU runs receiver and
3279 	 * did hash table lookup before we unhashed socket. They will achieve
3280 	 * receive queue and will be purged by socket destructor.
3281 	 *
3282 	 * Also we still have packets pending on receive queue and probably,
3283 	 * our own packets waiting in device queues. sock_destroy will drain
3284 	 * receive queue, but transmitted packets will delay socket destruction
3285 	 * until the last reference will be released.
3286 	 */
3287 
3288 	sock_orphan(sk);
3289 
3290 	xfrm_sk_free_policy(sk);
3291 
3292 	sk_refcnt_debug_release(sk);
3293 
3294 	sock_put(sk);
3295 }
3296 EXPORT_SYMBOL(sk_common_release);
3297 
3298 void sk_get_meminfo(const struct sock *sk, u32 *mem)
3299 {
3300 	memset(mem, 0, sizeof(*mem) * SK_MEMINFO_VARS);
3301 
3302 	mem[SK_MEMINFO_RMEM_ALLOC] = sk_rmem_alloc_get(sk);
3303 	mem[SK_MEMINFO_RCVBUF] = READ_ONCE(sk->sk_rcvbuf);
3304 	mem[SK_MEMINFO_WMEM_ALLOC] = sk_wmem_alloc_get(sk);
3305 	mem[SK_MEMINFO_SNDBUF] = READ_ONCE(sk->sk_sndbuf);
3306 	mem[SK_MEMINFO_FWD_ALLOC] = sk->sk_forward_alloc;
3307 	mem[SK_MEMINFO_WMEM_QUEUED] = READ_ONCE(sk->sk_wmem_queued);
3308 	mem[SK_MEMINFO_OPTMEM] = atomic_read(&sk->sk_omem_alloc);
3309 	mem[SK_MEMINFO_BACKLOG] = READ_ONCE(sk->sk_backlog.len);
3310 	mem[SK_MEMINFO_DROPS] = atomic_read(&sk->sk_drops);
3311 }
3312 
3313 #ifdef CONFIG_PROC_FS
3314 #define PROTO_INUSE_NR	64	/* should be enough for the first time */
3315 struct prot_inuse {
3316 	int val[PROTO_INUSE_NR];
3317 };
3318 
3319 static DECLARE_BITMAP(proto_inuse_idx, PROTO_INUSE_NR);
3320 
3321 void sock_prot_inuse_add(struct net *net, struct proto *prot, int val)
3322 {
3323 	__this_cpu_add(net->core.prot_inuse->val[prot->inuse_idx], val);
3324 }
3325 EXPORT_SYMBOL_GPL(sock_prot_inuse_add);
3326 
3327 int sock_prot_inuse_get(struct net *net, struct proto *prot)
3328 {
3329 	int cpu, idx = prot->inuse_idx;
3330 	int res = 0;
3331 
3332 	for_each_possible_cpu(cpu)
3333 		res += per_cpu_ptr(net->core.prot_inuse, cpu)->val[idx];
3334 
3335 	return res >= 0 ? res : 0;
3336 }
3337 EXPORT_SYMBOL_GPL(sock_prot_inuse_get);
3338 
3339 static void sock_inuse_add(struct net *net, int val)
3340 {
3341 	this_cpu_add(*net->core.sock_inuse, val);
3342 }
3343 
3344 int sock_inuse_get(struct net *net)
3345 {
3346 	int cpu, res = 0;
3347 
3348 	for_each_possible_cpu(cpu)
3349 		res += *per_cpu_ptr(net->core.sock_inuse, cpu);
3350 
3351 	return res;
3352 }
3353 
3354 EXPORT_SYMBOL_GPL(sock_inuse_get);
3355 
3356 static int __net_init sock_inuse_init_net(struct net *net)
3357 {
3358 	net->core.prot_inuse = alloc_percpu(struct prot_inuse);
3359 	if (net->core.prot_inuse == NULL)
3360 		return -ENOMEM;
3361 
3362 	net->core.sock_inuse = alloc_percpu(int);
3363 	if (net->core.sock_inuse == NULL)
3364 		goto out;
3365 
3366 	return 0;
3367 
3368 out:
3369 	free_percpu(net->core.prot_inuse);
3370 	return -ENOMEM;
3371 }
3372 
3373 static void __net_exit sock_inuse_exit_net(struct net *net)
3374 {
3375 	free_percpu(net->core.prot_inuse);
3376 	free_percpu(net->core.sock_inuse);
3377 }
3378 
3379 static struct pernet_operations net_inuse_ops = {
3380 	.init = sock_inuse_init_net,
3381 	.exit = sock_inuse_exit_net,
3382 };
3383 
3384 static __init int net_inuse_init(void)
3385 {
3386 	if (register_pernet_subsys(&net_inuse_ops))
3387 		panic("Cannot initialize net inuse counters");
3388 
3389 	return 0;
3390 }
3391 
3392 core_initcall(net_inuse_init);
3393 
3394 static int assign_proto_idx(struct proto *prot)
3395 {
3396 	prot->inuse_idx = find_first_zero_bit(proto_inuse_idx, PROTO_INUSE_NR);
3397 
3398 	if (unlikely(prot->inuse_idx == PROTO_INUSE_NR - 1)) {
3399 		pr_err("PROTO_INUSE_NR exhausted\n");
3400 		return -ENOSPC;
3401 	}
3402 
3403 	set_bit(prot->inuse_idx, proto_inuse_idx);
3404 	return 0;
3405 }
3406 
3407 static void release_proto_idx(struct proto *prot)
3408 {
3409 	if (prot->inuse_idx != PROTO_INUSE_NR - 1)
3410 		clear_bit(prot->inuse_idx, proto_inuse_idx);
3411 }
3412 #else
3413 static inline int assign_proto_idx(struct proto *prot)
3414 {
3415 	return 0;
3416 }
3417 
3418 static inline void release_proto_idx(struct proto *prot)
3419 {
3420 }
3421 
3422 static void sock_inuse_add(struct net *net, int val)
3423 {
3424 }
3425 #endif
3426 
3427 static void tw_prot_cleanup(struct timewait_sock_ops *twsk_prot)
3428 {
3429 	if (!twsk_prot)
3430 		return;
3431 	kfree(twsk_prot->twsk_slab_name);
3432 	twsk_prot->twsk_slab_name = NULL;
3433 	kmem_cache_destroy(twsk_prot->twsk_slab);
3434 	twsk_prot->twsk_slab = NULL;
3435 }
3436 
3437 static int tw_prot_init(const struct proto *prot)
3438 {
3439 	struct timewait_sock_ops *twsk_prot = prot->twsk_prot;
3440 
3441 	if (!twsk_prot)
3442 		return 0;
3443 
3444 	twsk_prot->twsk_slab_name = kasprintf(GFP_KERNEL, "tw_sock_%s",
3445 					      prot->name);
3446 	if (!twsk_prot->twsk_slab_name)
3447 		return -ENOMEM;
3448 
3449 	twsk_prot->twsk_slab =
3450 		kmem_cache_create(twsk_prot->twsk_slab_name,
3451 				  twsk_prot->twsk_obj_size, 0,
3452 				  SLAB_ACCOUNT | prot->slab_flags,
3453 				  NULL);
3454 	if (!twsk_prot->twsk_slab) {
3455 		pr_crit("%s: Can't create timewait sock SLAB cache!\n",
3456 			prot->name);
3457 		return -ENOMEM;
3458 	}
3459 
3460 	return 0;
3461 }
3462 
3463 static void req_prot_cleanup(struct request_sock_ops *rsk_prot)
3464 {
3465 	if (!rsk_prot)
3466 		return;
3467 	kfree(rsk_prot->slab_name);
3468 	rsk_prot->slab_name = NULL;
3469 	kmem_cache_destroy(rsk_prot->slab);
3470 	rsk_prot->slab = NULL;
3471 }
3472 
3473 static int req_prot_init(const struct proto *prot)
3474 {
3475 	struct request_sock_ops *rsk_prot = prot->rsk_prot;
3476 
3477 	if (!rsk_prot)
3478 		return 0;
3479 
3480 	rsk_prot->slab_name = kasprintf(GFP_KERNEL, "request_sock_%s",
3481 					prot->name);
3482 	if (!rsk_prot->slab_name)
3483 		return -ENOMEM;
3484 
3485 	rsk_prot->slab = kmem_cache_create(rsk_prot->slab_name,
3486 					   rsk_prot->obj_size, 0,
3487 					   SLAB_ACCOUNT | prot->slab_flags,
3488 					   NULL);
3489 
3490 	if (!rsk_prot->slab) {
3491 		pr_crit("%s: Can't create request sock SLAB cache!\n",
3492 			prot->name);
3493 		return -ENOMEM;
3494 	}
3495 	return 0;
3496 }
3497 
3498 int proto_register(struct proto *prot, int alloc_slab)
3499 {
3500 	int ret = -ENOBUFS;
3501 
3502 	if (alloc_slab) {
3503 		prot->slab = kmem_cache_create_usercopy(prot->name,
3504 					prot->obj_size, 0,
3505 					SLAB_HWCACHE_ALIGN | SLAB_ACCOUNT |
3506 					prot->slab_flags,
3507 					prot->useroffset, prot->usersize,
3508 					NULL);
3509 
3510 		if (prot->slab == NULL) {
3511 			pr_crit("%s: Can't create sock SLAB cache!\n",
3512 				prot->name);
3513 			goto out;
3514 		}
3515 
3516 		if (req_prot_init(prot))
3517 			goto out_free_request_sock_slab;
3518 
3519 		if (tw_prot_init(prot))
3520 			goto out_free_timewait_sock_slab;
3521 	}
3522 
3523 	mutex_lock(&proto_list_mutex);
3524 	ret = assign_proto_idx(prot);
3525 	if (ret) {
3526 		mutex_unlock(&proto_list_mutex);
3527 		goto out_free_timewait_sock_slab;
3528 	}
3529 	list_add(&prot->node, &proto_list);
3530 	mutex_unlock(&proto_list_mutex);
3531 	return ret;
3532 
3533 out_free_timewait_sock_slab:
3534 	if (alloc_slab)
3535 		tw_prot_cleanup(prot->twsk_prot);
3536 out_free_request_sock_slab:
3537 	if (alloc_slab) {
3538 		req_prot_cleanup(prot->rsk_prot);
3539 
3540 		kmem_cache_destroy(prot->slab);
3541 		prot->slab = NULL;
3542 	}
3543 out:
3544 	return ret;
3545 }
3546 EXPORT_SYMBOL(proto_register);
3547 
3548 void proto_unregister(struct proto *prot)
3549 {
3550 	mutex_lock(&proto_list_mutex);
3551 	release_proto_idx(prot);
3552 	list_del(&prot->node);
3553 	mutex_unlock(&proto_list_mutex);
3554 
3555 	kmem_cache_destroy(prot->slab);
3556 	prot->slab = NULL;
3557 
3558 	req_prot_cleanup(prot->rsk_prot);
3559 	tw_prot_cleanup(prot->twsk_prot);
3560 }
3561 EXPORT_SYMBOL(proto_unregister);
3562 
3563 int sock_load_diag_module(int family, int protocol)
3564 {
3565 	if (!protocol) {
3566 		if (!sock_is_registered(family))
3567 			return -ENOENT;
3568 
3569 		return request_module("net-pf-%d-proto-%d-type-%d", PF_NETLINK,
3570 				      NETLINK_SOCK_DIAG, family);
3571 	}
3572 
3573 #ifdef CONFIG_INET
3574 	if (family == AF_INET &&
3575 	    protocol != IPPROTO_RAW &&
3576 	    protocol < MAX_INET_PROTOS &&
3577 	    !rcu_access_pointer(inet_protos[protocol]))
3578 		return -ENOENT;
3579 #endif
3580 
3581 	return request_module("net-pf-%d-proto-%d-type-%d-%d", PF_NETLINK,
3582 			      NETLINK_SOCK_DIAG, family, protocol);
3583 }
3584 EXPORT_SYMBOL(sock_load_diag_module);
3585 
3586 #ifdef CONFIG_PROC_FS
3587 static void *proto_seq_start(struct seq_file *seq, loff_t *pos)
3588 	__acquires(proto_list_mutex)
3589 {
3590 	mutex_lock(&proto_list_mutex);
3591 	return seq_list_start_head(&proto_list, *pos);
3592 }
3593 
3594 static void *proto_seq_next(struct seq_file *seq, void *v, loff_t *pos)
3595 {
3596 	return seq_list_next(v, &proto_list, pos);
3597 }
3598 
3599 static void proto_seq_stop(struct seq_file *seq, void *v)
3600 	__releases(proto_list_mutex)
3601 {
3602 	mutex_unlock(&proto_list_mutex);
3603 }
3604 
3605 static char proto_method_implemented(const void *method)
3606 {
3607 	return method == NULL ? 'n' : 'y';
3608 }
3609 static long sock_prot_memory_allocated(struct proto *proto)
3610 {
3611 	return proto->memory_allocated != NULL ? proto_memory_allocated(proto) : -1L;
3612 }
3613 
3614 static const char *sock_prot_memory_pressure(struct proto *proto)
3615 {
3616 	return proto->memory_pressure != NULL ?
3617 	proto_memory_pressure(proto) ? "yes" : "no" : "NI";
3618 }
3619 
3620 static void proto_seq_printf(struct seq_file *seq, struct proto *proto)
3621 {
3622 
3623 	seq_printf(seq, "%-9s %4u %6d  %6ld   %-3s %6u   %-3s  %-10s "
3624 			"%2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c\n",
3625 		   proto->name,
3626 		   proto->obj_size,
3627 		   sock_prot_inuse_get(seq_file_net(seq), proto),
3628 		   sock_prot_memory_allocated(proto),
3629 		   sock_prot_memory_pressure(proto),
3630 		   proto->max_header,
3631 		   proto->slab == NULL ? "no" : "yes",
3632 		   module_name(proto->owner),
3633 		   proto_method_implemented(proto->close),
3634 		   proto_method_implemented(proto->connect),
3635 		   proto_method_implemented(proto->disconnect),
3636 		   proto_method_implemented(proto->accept),
3637 		   proto_method_implemented(proto->ioctl),
3638 		   proto_method_implemented(proto->init),
3639 		   proto_method_implemented(proto->destroy),
3640 		   proto_method_implemented(proto->shutdown),
3641 		   proto_method_implemented(proto->setsockopt),
3642 		   proto_method_implemented(proto->getsockopt),
3643 		   proto_method_implemented(proto->sendmsg),
3644 		   proto_method_implemented(proto->recvmsg),
3645 		   proto_method_implemented(proto->sendpage),
3646 		   proto_method_implemented(proto->bind),
3647 		   proto_method_implemented(proto->backlog_rcv),
3648 		   proto_method_implemented(proto->hash),
3649 		   proto_method_implemented(proto->unhash),
3650 		   proto_method_implemented(proto->get_port),
3651 		   proto_method_implemented(proto->enter_memory_pressure));
3652 }
3653 
3654 static int proto_seq_show(struct seq_file *seq, void *v)
3655 {
3656 	if (v == &proto_list)
3657 		seq_printf(seq, "%-9s %-4s %-8s %-6s %-5s %-7s %-4s %-10s %s",
3658 			   "protocol",
3659 			   "size",
3660 			   "sockets",
3661 			   "memory",
3662 			   "press",
3663 			   "maxhdr",
3664 			   "slab",
3665 			   "module",
3666 			   "cl co di ac io in de sh ss gs se re sp bi br ha uh gp em\n");
3667 	else
3668 		proto_seq_printf(seq, list_entry(v, struct proto, node));
3669 	return 0;
3670 }
3671 
3672 static const struct seq_operations proto_seq_ops = {
3673 	.start  = proto_seq_start,
3674 	.next   = proto_seq_next,
3675 	.stop   = proto_seq_stop,
3676 	.show   = proto_seq_show,
3677 };
3678 
3679 static __net_init int proto_init_net(struct net *net)
3680 {
3681 	if (!proc_create_net("protocols", 0444, net->proc_net, &proto_seq_ops,
3682 			sizeof(struct seq_net_private)))
3683 		return -ENOMEM;
3684 
3685 	return 0;
3686 }
3687 
3688 static __net_exit void proto_exit_net(struct net *net)
3689 {
3690 	remove_proc_entry("protocols", net->proc_net);
3691 }
3692 
3693 
3694 static __net_initdata struct pernet_operations proto_net_ops = {
3695 	.init = proto_init_net,
3696 	.exit = proto_exit_net,
3697 };
3698 
3699 static int __init proto_init(void)
3700 {
3701 	return register_pernet_subsys(&proto_net_ops);
3702 }
3703 
3704 subsys_initcall(proto_init);
3705 
3706 #endif /* PROC_FS */
3707 
3708 #ifdef CONFIG_NET_RX_BUSY_POLL
3709 bool sk_busy_loop_end(void *p, unsigned long start_time)
3710 {
3711 	struct sock *sk = p;
3712 
3713 	return !skb_queue_empty_lockless(&sk->sk_receive_queue) ||
3714 	       sk_busy_loop_timeout(sk, start_time);
3715 }
3716 EXPORT_SYMBOL(sk_busy_loop_end);
3717 #endif /* CONFIG_NET_RX_BUSY_POLL */
3718 
3719 int sock_bind_add(struct sock *sk, struct sockaddr *addr, int addr_len)
3720 {
3721 	if (!sk->sk_prot->bind_add)
3722 		return -EOPNOTSUPP;
3723 	return sk->sk_prot->bind_add(sk, addr, addr_len);
3724 }
3725 EXPORT_SYMBOL(sock_bind_add);
3726