xref: /openbmc/linux/net/core/sock.c (revision b03afaa8)
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 void sock_warn_obsolete_bsdism(const char *name)
417 {
418 	static int warned;
419 	static char warncomm[TASK_COMM_LEN];
420 	if (strcmp(warncomm, current->comm) && warned < 5) {
421 		strcpy(warncomm,  current->comm);
422 		pr_warn("process `%s' is using obsolete %s SO_BSDCOMPAT\n",
423 			warncomm, name);
424 		warned++;
425 	}
426 }
427 
428 static bool sock_needs_netstamp(const struct sock *sk)
429 {
430 	switch (sk->sk_family) {
431 	case AF_UNSPEC:
432 	case AF_UNIX:
433 		return false;
434 	default:
435 		return true;
436 	}
437 }
438 
439 static void sock_disable_timestamp(struct sock *sk, unsigned long flags)
440 {
441 	if (sk->sk_flags & flags) {
442 		sk->sk_flags &= ~flags;
443 		if (sock_needs_netstamp(sk) &&
444 		    !(sk->sk_flags & SK_FLAGS_TIMESTAMP))
445 			net_disable_timestamp();
446 	}
447 }
448 
449 
450 int __sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
451 {
452 	unsigned long flags;
453 	struct sk_buff_head *list = &sk->sk_receive_queue;
454 
455 	if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf) {
456 		atomic_inc(&sk->sk_drops);
457 		trace_sock_rcvqueue_full(sk, skb);
458 		return -ENOMEM;
459 	}
460 
461 	if (!sk_rmem_schedule(sk, skb, skb->truesize)) {
462 		atomic_inc(&sk->sk_drops);
463 		return -ENOBUFS;
464 	}
465 
466 	skb->dev = NULL;
467 	skb_set_owner_r(skb, sk);
468 
469 	/* we escape from rcu protected region, make sure we dont leak
470 	 * a norefcounted dst
471 	 */
472 	skb_dst_force(skb);
473 
474 	spin_lock_irqsave(&list->lock, flags);
475 	sock_skb_set_dropcount(sk, skb);
476 	__skb_queue_tail(list, skb);
477 	spin_unlock_irqrestore(&list->lock, flags);
478 
479 	if (!sock_flag(sk, SOCK_DEAD))
480 		sk->sk_data_ready(sk);
481 	return 0;
482 }
483 EXPORT_SYMBOL(__sock_queue_rcv_skb);
484 
485 int sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
486 {
487 	int err;
488 
489 	err = sk_filter(sk, skb);
490 	if (err)
491 		return err;
492 
493 	return __sock_queue_rcv_skb(sk, skb);
494 }
495 EXPORT_SYMBOL(sock_queue_rcv_skb);
496 
497 int __sk_receive_skb(struct sock *sk, struct sk_buff *skb,
498 		     const int nested, unsigned int trim_cap, bool refcounted)
499 {
500 	int rc = NET_RX_SUCCESS;
501 
502 	if (sk_filter_trim_cap(sk, skb, trim_cap))
503 		goto discard_and_relse;
504 
505 	skb->dev = NULL;
506 
507 	if (sk_rcvqueues_full(sk, sk->sk_rcvbuf)) {
508 		atomic_inc(&sk->sk_drops);
509 		goto discard_and_relse;
510 	}
511 	if (nested)
512 		bh_lock_sock_nested(sk);
513 	else
514 		bh_lock_sock(sk);
515 	if (!sock_owned_by_user(sk)) {
516 		/*
517 		 * trylock + unlock semantics:
518 		 */
519 		mutex_acquire(&sk->sk_lock.dep_map, 0, 1, _RET_IP_);
520 
521 		rc = sk_backlog_rcv(sk, skb);
522 
523 		mutex_release(&sk->sk_lock.dep_map, _RET_IP_);
524 	} else if (sk_add_backlog(sk, skb, READ_ONCE(sk->sk_rcvbuf))) {
525 		bh_unlock_sock(sk);
526 		atomic_inc(&sk->sk_drops);
527 		goto discard_and_relse;
528 	}
529 
530 	bh_unlock_sock(sk);
531 out:
532 	if (refcounted)
533 		sock_put(sk);
534 	return rc;
535 discard_and_relse:
536 	kfree_skb(skb);
537 	goto out;
538 }
539 EXPORT_SYMBOL(__sk_receive_skb);
540 
541 struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie)
542 {
543 	struct dst_entry *dst = __sk_dst_get(sk);
544 
545 	if (dst && dst->obsolete && dst->ops->check(dst, cookie) == NULL) {
546 		sk_tx_queue_clear(sk);
547 		sk->sk_dst_pending_confirm = 0;
548 		RCU_INIT_POINTER(sk->sk_dst_cache, NULL);
549 		dst_release(dst);
550 		return NULL;
551 	}
552 
553 	return dst;
554 }
555 EXPORT_SYMBOL(__sk_dst_check);
556 
557 struct dst_entry *sk_dst_check(struct sock *sk, u32 cookie)
558 {
559 	struct dst_entry *dst = sk_dst_get(sk);
560 
561 	if (dst && dst->obsolete && dst->ops->check(dst, cookie) == NULL) {
562 		sk_dst_reset(sk);
563 		dst_release(dst);
564 		return NULL;
565 	}
566 
567 	return dst;
568 }
569 EXPORT_SYMBOL(sk_dst_check);
570 
571 static int sock_bindtoindex_locked(struct sock *sk, int ifindex)
572 {
573 	int ret = -ENOPROTOOPT;
574 #ifdef CONFIG_NETDEVICES
575 	struct net *net = sock_net(sk);
576 
577 	/* Sorry... */
578 	ret = -EPERM;
579 	if (sk->sk_bound_dev_if && !ns_capable(net->user_ns, CAP_NET_RAW))
580 		goto out;
581 
582 	ret = -EINVAL;
583 	if (ifindex < 0)
584 		goto out;
585 
586 	sk->sk_bound_dev_if = ifindex;
587 	if (sk->sk_prot->rehash)
588 		sk->sk_prot->rehash(sk);
589 	sk_dst_reset(sk);
590 
591 	ret = 0;
592 
593 out:
594 #endif
595 
596 	return ret;
597 }
598 
599 int sock_bindtoindex(struct sock *sk, int ifindex, bool lock_sk)
600 {
601 	int ret;
602 
603 	if (lock_sk)
604 		lock_sock(sk);
605 	ret = sock_bindtoindex_locked(sk, ifindex);
606 	if (lock_sk)
607 		release_sock(sk);
608 
609 	return ret;
610 }
611 EXPORT_SYMBOL(sock_bindtoindex);
612 
613 static int sock_setbindtodevice(struct sock *sk, sockptr_t optval, int optlen)
614 {
615 	int ret = -ENOPROTOOPT;
616 #ifdef CONFIG_NETDEVICES
617 	struct net *net = sock_net(sk);
618 	char devname[IFNAMSIZ];
619 	int index;
620 
621 	ret = -EINVAL;
622 	if (optlen < 0)
623 		goto out;
624 
625 	/* Bind this socket to a particular device like "eth0",
626 	 * as specified in the passed interface name. If the
627 	 * name is "" or the option length is zero the socket
628 	 * is not bound.
629 	 */
630 	if (optlen > IFNAMSIZ - 1)
631 		optlen = IFNAMSIZ - 1;
632 	memset(devname, 0, sizeof(devname));
633 
634 	ret = -EFAULT;
635 	if (copy_from_sockptr(devname, optval, optlen))
636 		goto out;
637 
638 	index = 0;
639 	if (devname[0] != '\0') {
640 		struct net_device *dev;
641 
642 		rcu_read_lock();
643 		dev = dev_get_by_name_rcu(net, devname);
644 		if (dev)
645 			index = dev->ifindex;
646 		rcu_read_unlock();
647 		ret = -ENODEV;
648 		if (!dev)
649 			goto out;
650 	}
651 
652 	return sock_bindtoindex(sk, index, true);
653 out:
654 #endif
655 
656 	return ret;
657 }
658 
659 static int sock_getbindtodevice(struct sock *sk, char __user *optval,
660 				int __user *optlen, int len)
661 {
662 	int ret = -ENOPROTOOPT;
663 #ifdef CONFIG_NETDEVICES
664 	struct net *net = sock_net(sk);
665 	char devname[IFNAMSIZ];
666 
667 	if (sk->sk_bound_dev_if == 0) {
668 		len = 0;
669 		goto zero;
670 	}
671 
672 	ret = -EINVAL;
673 	if (len < IFNAMSIZ)
674 		goto out;
675 
676 	ret = netdev_get_name(net, devname, sk->sk_bound_dev_if);
677 	if (ret)
678 		goto out;
679 
680 	len = strlen(devname) + 1;
681 
682 	ret = -EFAULT;
683 	if (copy_to_user(optval, devname, len))
684 		goto out;
685 
686 zero:
687 	ret = -EFAULT;
688 	if (put_user(len, optlen))
689 		goto out;
690 
691 	ret = 0;
692 
693 out:
694 #endif
695 
696 	return ret;
697 }
698 
699 bool sk_mc_loop(struct sock *sk)
700 {
701 	if (dev_recursion_level())
702 		return false;
703 	if (!sk)
704 		return true;
705 	switch (sk->sk_family) {
706 	case AF_INET:
707 		return inet_sk(sk)->mc_loop;
708 #if IS_ENABLED(CONFIG_IPV6)
709 	case AF_INET6:
710 		return inet6_sk(sk)->mc_loop;
711 #endif
712 	}
713 	WARN_ON_ONCE(1);
714 	return true;
715 }
716 EXPORT_SYMBOL(sk_mc_loop);
717 
718 void sock_set_reuseaddr(struct sock *sk)
719 {
720 	lock_sock(sk);
721 	sk->sk_reuse = SK_CAN_REUSE;
722 	release_sock(sk);
723 }
724 EXPORT_SYMBOL(sock_set_reuseaddr);
725 
726 void sock_set_reuseport(struct sock *sk)
727 {
728 	lock_sock(sk);
729 	sk->sk_reuseport = true;
730 	release_sock(sk);
731 }
732 EXPORT_SYMBOL(sock_set_reuseport);
733 
734 void sock_no_linger(struct sock *sk)
735 {
736 	lock_sock(sk);
737 	sk->sk_lingertime = 0;
738 	sock_set_flag(sk, SOCK_LINGER);
739 	release_sock(sk);
740 }
741 EXPORT_SYMBOL(sock_no_linger);
742 
743 void sock_set_priority(struct sock *sk, u32 priority)
744 {
745 	lock_sock(sk);
746 	sk->sk_priority = priority;
747 	release_sock(sk);
748 }
749 EXPORT_SYMBOL(sock_set_priority);
750 
751 void sock_set_sndtimeo(struct sock *sk, s64 secs)
752 {
753 	lock_sock(sk);
754 	if (secs && secs < MAX_SCHEDULE_TIMEOUT / HZ - 1)
755 		sk->sk_sndtimeo = secs * HZ;
756 	else
757 		sk->sk_sndtimeo = MAX_SCHEDULE_TIMEOUT;
758 	release_sock(sk);
759 }
760 EXPORT_SYMBOL(sock_set_sndtimeo);
761 
762 static void __sock_set_timestamps(struct sock *sk, bool val, bool new, bool ns)
763 {
764 	if (val)  {
765 		sock_valbool_flag(sk, SOCK_TSTAMP_NEW, new);
766 		sock_valbool_flag(sk, SOCK_RCVTSTAMPNS, ns);
767 		sock_set_flag(sk, SOCK_RCVTSTAMP);
768 		sock_enable_timestamp(sk, SOCK_TIMESTAMP);
769 	} else {
770 		sock_reset_flag(sk, SOCK_RCVTSTAMP);
771 		sock_reset_flag(sk, SOCK_RCVTSTAMPNS);
772 		sock_reset_flag(sk, SOCK_TSTAMP_NEW);
773 	}
774 }
775 
776 void sock_enable_timestamps(struct sock *sk)
777 {
778 	lock_sock(sk);
779 	__sock_set_timestamps(sk, true, false, true);
780 	release_sock(sk);
781 }
782 EXPORT_SYMBOL(sock_enable_timestamps);
783 
784 void sock_set_keepalive(struct sock *sk)
785 {
786 	lock_sock(sk);
787 	if (sk->sk_prot->keepalive)
788 		sk->sk_prot->keepalive(sk, true);
789 	sock_valbool_flag(sk, SOCK_KEEPOPEN, true);
790 	release_sock(sk);
791 }
792 EXPORT_SYMBOL(sock_set_keepalive);
793 
794 static void __sock_set_rcvbuf(struct sock *sk, int val)
795 {
796 	/* Ensure val * 2 fits into an int, to prevent max_t() from treating it
797 	 * as a negative value.
798 	 */
799 	val = min_t(int, val, INT_MAX / 2);
800 	sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
801 
802 	/* We double it on the way in to account for "struct sk_buff" etc.
803 	 * overhead.   Applications assume that the SO_RCVBUF setting they make
804 	 * will allow that much actual data to be received on that socket.
805 	 *
806 	 * Applications are unaware that "struct sk_buff" and other overheads
807 	 * allocate from the receive buffer during socket buffer allocation.
808 	 *
809 	 * And after considering the possible alternatives, returning the value
810 	 * we actually used in getsockopt is the most desirable behavior.
811 	 */
812 	WRITE_ONCE(sk->sk_rcvbuf, max_t(int, val * 2, SOCK_MIN_RCVBUF));
813 }
814 
815 void sock_set_rcvbuf(struct sock *sk, int val)
816 {
817 	lock_sock(sk);
818 	__sock_set_rcvbuf(sk, val);
819 	release_sock(sk);
820 }
821 EXPORT_SYMBOL(sock_set_rcvbuf);
822 
823 /*
824  *	This is meant for all protocols to use and covers goings on
825  *	at the socket level. Everything here is generic.
826  */
827 
828 int sock_setsockopt(struct socket *sock, int level, int optname,
829 		    sockptr_t optval, unsigned int optlen)
830 {
831 	struct sock_txtime sk_txtime;
832 	struct sock *sk = sock->sk;
833 	int val;
834 	int valbool;
835 	struct linger ling;
836 	int ret = 0;
837 
838 	/*
839 	 *	Options without arguments
840 	 */
841 
842 	if (optname == SO_BINDTODEVICE)
843 		return sock_setbindtodevice(sk, optval, optlen);
844 
845 	if (optlen < sizeof(int))
846 		return -EINVAL;
847 
848 	if (copy_from_sockptr(&val, optval, sizeof(val)))
849 		return -EFAULT;
850 
851 	valbool = val ? 1 : 0;
852 
853 	lock_sock(sk);
854 
855 	switch (optname) {
856 	case SO_DEBUG:
857 		if (val && !capable(CAP_NET_ADMIN))
858 			ret = -EACCES;
859 		else
860 			sock_valbool_flag(sk, SOCK_DBG, valbool);
861 		break;
862 	case SO_REUSEADDR:
863 		sk->sk_reuse = (valbool ? SK_CAN_REUSE : SK_NO_REUSE);
864 		break;
865 	case SO_REUSEPORT:
866 		sk->sk_reuseport = valbool;
867 		break;
868 	case SO_TYPE:
869 	case SO_PROTOCOL:
870 	case SO_DOMAIN:
871 	case SO_ERROR:
872 		ret = -ENOPROTOOPT;
873 		break;
874 	case SO_DONTROUTE:
875 		sock_valbool_flag(sk, SOCK_LOCALROUTE, valbool);
876 		sk_dst_reset(sk);
877 		break;
878 	case SO_BROADCAST:
879 		sock_valbool_flag(sk, SOCK_BROADCAST, valbool);
880 		break;
881 	case SO_SNDBUF:
882 		/* Don't error on this BSD doesn't and if you think
883 		 * about it this is right. Otherwise apps have to
884 		 * play 'guess the biggest size' games. RCVBUF/SNDBUF
885 		 * are treated in BSD as hints
886 		 */
887 		val = min_t(u32, val, sysctl_wmem_max);
888 set_sndbuf:
889 		/* Ensure val * 2 fits into an int, to prevent max_t()
890 		 * from treating it as a negative value.
891 		 */
892 		val = min_t(int, val, INT_MAX / 2);
893 		sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
894 		WRITE_ONCE(sk->sk_sndbuf,
895 			   max_t(int, val * 2, SOCK_MIN_SNDBUF));
896 		/* Wake up sending tasks if we upped the value. */
897 		sk->sk_write_space(sk);
898 		break;
899 
900 	case SO_SNDBUFFORCE:
901 		if (!capable(CAP_NET_ADMIN)) {
902 			ret = -EPERM;
903 			break;
904 		}
905 
906 		/* No negative values (to prevent underflow, as val will be
907 		 * multiplied by 2).
908 		 */
909 		if (val < 0)
910 			val = 0;
911 		goto set_sndbuf;
912 
913 	case SO_RCVBUF:
914 		/* Don't error on this BSD doesn't and if you think
915 		 * about it this is right. Otherwise apps have to
916 		 * play 'guess the biggest size' games. RCVBUF/SNDBUF
917 		 * are treated in BSD as hints
918 		 */
919 		__sock_set_rcvbuf(sk, min_t(u32, val, sysctl_rmem_max));
920 		break;
921 
922 	case SO_RCVBUFFORCE:
923 		if (!capable(CAP_NET_ADMIN)) {
924 			ret = -EPERM;
925 			break;
926 		}
927 
928 		/* No negative values (to prevent underflow, as val will be
929 		 * multiplied by 2).
930 		 */
931 		__sock_set_rcvbuf(sk, max(val, 0));
932 		break;
933 
934 	case SO_KEEPALIVE:
935 		if (sk->sk_prot->keepalive)
936 			sk->sk_prot->keepalive(sk, valbool);
937 		sock_valbool_flag(sk, SOCK_KEEPOPEN, valbool);
938 		break;
939 
940 	case SO_OOBINLINE:
941 		sock_valbool_flag(sk, SOCK_URGINLINE, valbool);
942 		break;
943 
944 	case SO_NO_CHECK:
945 		sk->sk_no_check_tx = valbool;
946 		break;
947 
948 	case SO_PRIORITY:
949 		if ((val >= 0 && val <= 6) ||
950 		    ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
951 			sk->sk_priority = val;
952 		else
953 			ret = -EPERM;
954 		break;
955 
956 	case SO_LINGER:
957 		if (optlen < sizeof(ling)) {
958 			ret = -EINVAL;	/* 1003.1g */
959 			break;
960 		}
961 		if (copy_from_sockptr(&ling, optval, sizeof(ling))) {
962 			ret = -EFAULT;
963 			break;
964 		}
965 		if (!ling.l_onoff)
966 			sock_reset_flag(sk, SOCK_LINGER);
967 		else {
968 #if (BITS_PER_LONG == 32)
969 			if ((unsigned int)ling.l_linger >= MAX_SCHEDULE_TIMEOUT/HZ)
970 				sk->sk_lingertime = MAX_SCHEDULE_TIMEOUT;
971 			else
972 #endif
973 				sk->sk_lingertime = (unsigned int)ling.l_linger * HZ;
974 			sock_set_flag(sk, SOCK_LINGER);
975 		}
976 		break;
977 
978 	case SO_BSDCOMPAT:
979 		sock_warn_obsolete_bsdism("setsockopt");
980 		break;
981 
982 	case SO_PASSCRED:
983 		if (valbool)
984 			set_bit(SOCK_PASSCRED, &sock->flags);
985 		else
986 			clear_bit(SOCK_PASSCRED, &sock->flags);
987 		break;
988 
989 	case SO_TIMESTAMP_OLD:
990 		__sock_set_timestamps(sk, valbool, false, false);
991 		break;
992 	case SO_TIMESTAMP_NEW:
993 		__sock_set_timestamps(sk, valbool, true, false);
994 		break;
995 	case SO_TIMESTAMPNS_OLD:
996 		__sock_set_timestamps(sk, valbool, false, true);
997 		break;
998 	case SO_TIMESTAMPNS_NEW:
999 		__sock_set_timestamps(sk, valbool, true, true);
1000 		break;
1001 	case SO_TIMESTAMPING_NEW:
1002 		sock_set_flag(sk, SOCK_TSTAMP_NEW);
1003 		/* fall through */
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 		if (val & SOF_TIMESTAMPING_RX_SOFTWARE)
1033 			sock_enable_timestamp(sk,
1034 					      SOCK_TIMESTAMPING_RX_SOFTWARE);
1035 		else {
1036 			if (optname == SO_TIMESTAMPING_NEW)
1037 				sock_reset_flag(sk, SOCK_TSTAMP_NEW);
1038 
1039 			sock_disable_timestamp(sk,
1040 					       (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE));
1041 		}
1042 		break;
1043 
1044 	case SO_RCVLOWAT:
1045 		if (val < 0)
1046 			val = INT_MAX;
1047 		if (sock->ops->set_rcvlowat)
1048 			ret = sock->ops->set_rcvlowat(sk, val);
1049 		else
1050 			WRITE_ONCE(sk->sk_rcvlowat, val ? : 1);
1051 		break;
1052 
1053 	case SO_RCVTIMEO_OLD:
1054 	case SO_RCVTIMEO_NEW:
1055 		ret = sock_set_timeout(&sk->sk_rcvtimeo, optval,
1056 				       optlen, optname == SO_RCVTIMEO_OLD);
1057 		break;
1058 
1059 	case SO_SNDTIMEO_OLD:
1060 	case SO_SNDTIMEO_NEW:
1061 		ret = sock_set_timeout(&sk->sk_sndtimeo, optval,
1062 				       optlen, optname == SO_SNDTIMEO_OLD);
1063 		break;
1064 
1065 	case SO_ATTACH_FILTER: {
1066 		struct sock_fprog fprog;
1067 
1068 		ret = copy_bpf_fprog_from_user(&fprog, optval, optlen);
1069 		if (!ret)
1070 			ret = sk_attach_filter(&fprog, sk);
1071 		break;
1072 	}
1073 	case SO_ATTACH_BPF:
1074 		ret = -EINVAL;
1075 		if (optlen == sizeof(u32)) {
1076 			u32 ufd;
1077 
1078 			ret = -EFAULT;
1079 			if (copy_from_sockptr(&ufd, optval, sizeof(ufd)))
1080 				break;
1081 
1082 			ret = sk_attach_bpf(ufd, sk);
1083 		}
1084 		break;
1085 
1086 	case SO_ATTACH_REUSEPORT_CBPF: {
1087 		struct sock_fprog fprog;
1088 
1089 		ret = copy_bpf_fprog_from_user(&fprog, optval, optlen);
1090 		if (!ret)
1091 			ret = sk_reuseport_attach_filter(&fprog, sk);
1092 		break;
1093 	}
1094 	case SO_ATTACH_REUSEPORT_EBPF:
1095 		ret = -EINVAL;
1096 		if (optlen == sizeof(u32)) {
1097 			u32 ufd;
1098 
1099 			ret = -EFAULT;
1100 			if (copy_from_sockptr(&ufd, optval, sizeof(ufd)))
1101 				break;
1102 
1103 			ret = sk_reuseport_attach_bpf(ufd, sk);
1104 		}
1105 		break;
1106 
1107 	case SO_DETACH_REUSEPORT_BPF:
1108 		ret = reuseport_detach_prog(sk);
1109 		break;
1110 
1111 	case SO_DETACH_FILTER:
1112 		ret = sk_detach_filter(sk);
1113 		break;
1114 
1115 	case SO_LOCK_FILTER:
1116 		if (sock_flag(sk, SOCK_FILTER_LOCKED) && !valbool)
1117 			ret = -EPERM;
1118 		else
1119 			sock_valbool_flag(sk, SOCK_FILTER_LOCKED, valbool);
1120 		break;
1121 
1122 	case SO_PASSSEC:
1123 		if (valbool)
1124 			set_bit(SOCK_PASSSEC, &sock->flags);
1125 		else
1126 			clear_bit(SOCK_PASSSEC, &sock->flags);
1127 		break;
1128 	case SO_MARK:
1129 		if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) {
1130 			ret = -EPERM;
1131 		} else if (val != sk->sk_mark) {
1132 			sk->sk_mark = val;
1133 			sk_dst_reset(sk);
1134 		}
1135 		break;
1136 
1137 	case SO_RXQ_OVFL:
1138 		sock_valbool_flag(sk, SOCK_RXQ_OVFL, valbool);
1139 		break;
1140 
1141 	case SO_WIFI_STATUS:
1142 		sock_valbool_flag(sk, SOCK_WIFI_STATUS, valbool);
1143 		break;
1144 
1145 	case SO_PEEK_OFF:
1146 		if (sock->ops->set_peek_off)
1147 			ret = sock->ops->set_peek_off(sk, val);
1148 		else
1149 			ret = -EOPNOTSUPP;
1150 		break;
1151 
1152 	case SO_NOFCS:
1153 		sock_valbool_flag(sk, SOCK_NOFCS, valbool);
1154 		break;
1155 
1156 	case SO_SELECT_ERR_QUEUE:
1157 		sock_valbool_flag(sk, SOCK_SELECT_ERR_QUEUE, valbool);
1158 		break;
1159 
1160 #ifdef CONFIG_NET_RX_BUSY_POLL
1161 	case SO_BUSY_POLL:
1162 		/* allow unprivileged users to decrease the value */
1163 		if ((val > sk->sk_ll_usec) && !capable(CAP_NET_ADMIN))
1164 			ret = -EPERM;
1165 		else {
1166 			if (val < 0)
1167 				ret = -EINVAL;
1168 			else
1169 				sk->sk_ll_usec = val;
1170 		}
1171 		break;
1172 #endif
1173 
1174 	case SO_MAX_PACING_RATE:
1175 		{
1176 		unsigned long ulval = (val == ~0U) ? ~0UL : val;
1177 
1178 		if (sizeof(ulval) != sizeof(val) &&
1179 		    optlen >= sizeof(ulval) &&
1180 		    copy_from_sockptr(&ulval, optval, sizeof(ulval))) {
1181 			ret = -EFAULT;
1182 			break;
1183 		}
1184 		if (ulval != ~0UL)
1185 			cmpxchg(&sk->sk_pacing_status,
1186 				SK_PACING_NONE,
1187 				SK_PACING_NEEDED);
1188 		sk->sk_max_pacing_rate = ulval;
1189 		sk->sk_pacing_rate = min(sk->sk_pacing_rate, ulval);
1190 		break;
1191 		}
1192 	case SO_INCOMING_CPU:
1193 		WRITE_ONCE(sk->sk_incoming_cpu, val);
1194 		break;
1195 
1196 	case SO_CNX_ADVICE:
1197 		if (val == 1)
1198 			dst_negative_advice(sk);
1199 		break;
1200 
1201 	case SO_ZEROCOPY:
1202 		if (sk->sk_family == PF_INET || sk->sk_family == PF_INET6) {
1203 			if (!((sk->sk_type == SOCK_STREAM &&
1204 			       sk->sk_protocol == IPPROTO_TCP) ||
1205 			      (sk->sk_type == SOCK_DGRAM &&
1206 			       sk->sk_protocol == IPPROTO_UDP)))
1207 				ret = -ENOTSUPP;
1208 		} else if (sk->sk_family != PF_RDS) {
1209 			ret = -ENOTSUPP;
1210 		}
1211 		if (!ret) {
1212 			if (val < 0 || val > 1)
1213 				ret = -EINVAL;
1214 			else
1215 				sock_valbool_flag(sk, SOCK_ZEROCOPY, valbool);
1216 		}
1217 		break;
1218 
1219 	case SO_TXTIME:
1220 		if (optlen != sizeof(struct sock_txtime)) {
1221 			ret = -EINVAL;
1222 			break;
1223 		} else if (copy_from_sockptr(&sk_txtime, optval,
1224 			   sizeof(struct sock_txtime))) {
1225 			ret = -EFAULT;
1226 			break;
1227 		} else if (sk_txtime.flags & ~SOF_TXTIME_FLAGS_MASK) {
1228 			ret = -EINVAL;
1229 			break;
1230 		}
1231 		/* CLOCK_MONOTONIC is only used by sch_fq, and this packet
1232 		 * scheduler has enough safe guards.
1233 		 */
1234 		if (sk_txtime.clockid != CLOCK_MONOTONIC &&
1235 		    !ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) {
1236 			ret = -EPERM;
1237 			break;
1238 		}
1239 		sock_valbool_flag(sk, SOCK_TXTIME, true);
1240 		sk->sk_clockid = sk_txtime.clockid;
1241 		sk->sk_txtime_deadline_mode =
1242 			!!(sk_txtime.flags & SOF_TXTIME_DEADLINE_MODE);
1243 		sk->sk_txtime_report_errors =
1244 			!!(sk_txtime.flags & SOF_TXTIME_REPORT_ERRORS);
1245 		break;
1246 
1247 	case SO_BINDTOIFINDEX:
1248 		ret = sock_bindtoindex_locked(sk, val);
1249 		break;
1250 
1251 	default:
1252 		ret = -ENOPROTOOPT;
1253 		break;
1254 	}
1255 	release_sock(sk);
1256 	return ret;
1257 }
1258 EXPORT_SYMBOL(sock_setsockopt);
1259 
1260 
1261 static void cred_to_ucred(struct pid *pid, const struct cred *cred,
1262 			  struct ucred *ucred)
1263 {
1264 	ucred->pid = pid_vnr(pid);
1265 	ucred->uid = ucred->gid = -1;
1266 	if (cred) {
1267 		struct user_namespace *current_ns = current_user_ns();
1268 
1269 		ucred->uid = from_kuid_munged(current_ns, cred->euid);
1270 		ucred->gid = from_kgid_munged(current_ns, cred->egid);
1271 	}
1272 }
1273 
1274 static int groups_to_user(gid_t __user *dst, const struct group_info *src)
1275 {
1276 	struct user_namespace *user_ns = current_user_ns();
1277 	int i;
1278 
1279 	for (i = 0; i < src->ngroups; i++)
1280 		if (put_user(from_kgid_munged(user_ns, src->gid[i]), dst + i))
1281 			return -EFAULT;
1282 
1283 	return 0;
1284 }
1285 
1286 int sock_getsockopt(struct socket *sock, int level, int optname,
1287 		    char __user *optval, int __user *optlen)
1288 {
1289 	struct sock *sk = sock->sk;
1290 
1291 	union {
1292 		int val;
1293 		u64 val64;
1294 		unsigned long ulval;
1295 		struct linger ling;
1296 		struct old_timeval32 tm32;
1297 		struct __kernel_old_timeval tm;
1298 		struct  __kernel_sock_timeval stm;
1299 		struct sock_txtime txtime;
1300 	} v;
1301 
1302 	int lv = sizeof(int);
1303 	int len;
1304 
1305 	if (get_user(len, optlen))
1306 		return -EFAULT;
1307 	if (len < 0)
1308 		return -EINVAL;
1309 
1310 	memset(&v, 0, sizeof(v));
1311 
1312 	switch (optname) {
1313 	case SO_DEBUG:
1314 		v.val = sock_flag(sk, SOCK_DBG);
1315 		break;
1316 
1317 	case SO_DONTROUTE:
1318 		v.val = sock_flag(sk, SOCK_LOCALROUTE);
1319 		break;
1320 
1321 	case SO_BROADCAST:
1322 		v.val = sock_flag(sk, SOCK_BROADCAST);
1323 		break;
1324 
1325 	case SO_SNDBUF:
1326 		v.val = sk->sk_sndbuf;
1327 		break;
1328 
1329 	case SO_RCVBUF:
1330 		v.val = sk->sk_rcvbuf;
1331 		break;
1332 
1333 	case SO_REUSEADDR:
1334 		v.val = sk->sk_reuse;
1335 		break;
1336 
1337 	case SO_REUSEPORT:
1338 		v.val = sk->sk_reuseport;
1339 		break;
1340 
1341 	case SO_KEEPALIVE:
1342 		v.val = sock_flag(sk, SOCK_KEEPOPEN);
1343 		break;
1344 
1345 	case SO_TYPE:
1346 		v.val = sk->sk_type;
1347 		break;
1348 
1349 	case SO_PROTOCOL:
1350 		v.val = sk->sk_protocol;
1351 		break;
1352 
1353 	case SO_DOMAIN:
1354 		v.val = sk->sk_family;
1355 		break;
1356 
1357 	case SO_ERROR:
1358 		v.val = -sock_error(sk);
1359 		if (v.val == 0)
1360 			v.val = xchg(&sk->sk_err_soft, 0);
1361 		break;
1362 
1363 	case SO_OOBINLINE:
1364 		v.val = sock_flag(sk, SOCK_URGINLINE);
1365 		break;
1366 
1367 	case SO_NO_CHECK:
1368 		v.val = sk->sk_no_check_tx;
1369 		break;
1370 
1371 	case SO_PRIORITY:
1372 		v.val = sk->sk_priority;
1373 		break;
1374 
1375 	case SO_LINGER:
1376 		lv		= sizeof(v.ling);
1377 		v.ling.l_onoff	= sock_flag(sk, SOCK_LINGER);
1378 		v.ling.l_linger	= sk->sk_lingertime / HZ;
1379 		break;
1380 
1381 	case SO_BSDCOMPAT:
1382 		sock_warn_obsolete_bsdism("getsockopt");
1383 		break;
1384 
1385 	case SO_TIMESTAMP_OLD:
1386 		v.val = sock_flag(sk, SOCK_RCVTSTAMP) &&
1387 				!sock_flag(sk, SOCK_TSTAMP_NEW) &&
1388 				!sock_flag(sk, SOCK_RCVTSTAMPNS);
1389 		break;
1390 
1391 	case SO_TIMESTAMPNS_OLD:
1392 		v.val = sock_flag(sk, SOCK_RCVTSTAMPNS) && !sock_flag(sk, SOCK_TSTAMP_NEW);
1393 		break;
1394 
1395 	case SO_TIMESTAMP_NEW:
1396 		v.val = sock_flag(sk, SOCK_RCVTSTAMP) && sock_flag(sk, SOCK_TSTAMP_NEW);
1397 		break;
1398 
1399 	case SO_TIMESTAMPNS_NEW:
1400 		v.val = sock_flag(sk, SOCK_RCVTSTAMPNS) && sock_flag(sk, SOCK_TSTAMP_NEW);
1401 		break;
1402 
1403 	case SO_TIMESTAMPING_OLD:
1404 		v.val = sk->sk_tsflags;
1405 		break;
1406 
1407 	case SO_RCVTIMEO_OLD:
1408 	case SO_RCVTIMEO_NEW:
1409 		lv = sock_get_timeout(sk->sk_rcvtimeo, &v, SO_RCVTIMEO_OLD == optname);
1410 		break;
1411 
1412 	case SO_SNDTIMEO_OLD:
1413 	case SO_SNDTIMEO_NEW:
1414 		lv = sock_get_timeout(sk->sk_sndtimeo, &v, SO_SNDTIMEO_OLD == optname);
1415 		break;
1416 
1417 	case SO_RCVLOWAT:
1418 		v.val = sk->sk_rcvlowat;
1419 		break;
1420 
1421 	case SO_SNDLOWAT:
1422 		v.val = 1;
1423 		break;
1424 
1425 	case SO_PASSCRED:
1426 		v.val = !!test_bit(SOCK_PASSCRED, &sock->flags);
1427 		break;
1428 
1429 	case SO_PEERCRED:
1430 	{
1431 		struct ucred peercred;
1432 		if (len > sizeof(peercred))
1433 			len = sizeof(peercred);
1434 		cred_to_ucred(sk->sk_peer_pid, sk->sk_peer_cred, &peercred);
1435 		if (copy_to_user(optval, &peercred, len))
1436 			return -EFAULT;
1437 		goto lenout;
1438 	}
1439 
1440 	case SO_PEERGROUPS:
1441 	{
1442 		int ret, n;
1443 
1444 		if (!sk->sk_peer_cred)
1445 			return -ENODATA;
1446 
1447 		n = sk->sk_peer_cred->group_info->ngroups;
1448 		if (len < n * sizeof(gid_t)) {
1449 			len = n * sizeof(gid_t);
1450 			return put_user(len, optlen) ? -EFAULT : -ERANGE;
1451 		}
1452 		len = n * sizeof(gid_t);
1453 
1454 		ret = groups_to_user((gid_t __user *)optval,
1455 				     sk->sk_peer_cred->group_info);
1456 		if (ret)
1457 			return ret;
1458 		goto lenout;
1459 	}
1460 
1461 	case SO_PEERNAME:
1462 	{
1463 		char address[128];
1464 
1465 		lv = sock->ops->getname(sock, (struct sockaddr *)address, 2);
1466 		if (lv < 0)
1467 			return -ENOTCONN;
1468 		if (lv < len)
1469 			return -EINVAL;
1470 		if (copy_to_user(optval, address, len))
1471 			return -EFAULT;
1472 		goto lenout;
1473 	}
1474 
1475 	/* Dubious BSD thing... Probably nobody even uses it, but
1476 	 * the UNIX standard wants it for whatever reason... -DaveM
1477 	 */
1478 	case SO_ACCEPTCONN:
1479 		v.val = sk->sk_state == TCP_LISTEN;
1480 		break;
1481 
1482 	case SO_PASSSEC:
1483 		v.val = !!test_bit(SOCK_PASSSEC, &sock->flags);
1484 		break;
1485 
1486 	case SO_PEERSEC:
1487 		return security_socket_getpeersec_stream(sock, optval, optlen, len);
1488 
1489 	case SO_MARK:
1490 		v.val = sk->sk_mark;
1491 		break;
1492 
1493 	case SO_RXQ_OVFL:
1494 		v.val = sock_flag(sk, SOCK_RXQ_OVFL);
1495 		break;
1496 
1497 	case SO_WIFI_STATUS:
1498 		v.val = sock_flag(sk, SOCK_WIFI_STATUS);
1499 		break;
1500 
1501 	case SO_PEEK_OFF:
1502 		if (!sock->ops->set_peek_off)
1503 			return -EOPNOTSUPP;
1504 
1505 		v.val = sk->sk_peek_off;
1506 		break;
1507 	case SO_NOFCS:
1508 		v.val = sock_flag(sk, SOCK_NOFCS);
1509 		break;
1510 
1511 	case SO_BINDTODEVICE:
1512 		return sock_getbindtodevice(sk, optval, optlen, len);
1513 
1514 	case SO_GET_FILTER:
1515 		len = sk_get_filter(sk, (struct sock_filter __user *)optval, len);
1516 		if (len < 0)
1517 			return len;
1518 
1519 		goto lenout;
1520 
1521 	case SO_LOCK_FILTER:
1522 		v.val = sock_flag(sk, SOCK_FILTER_LOCKED);
1523 		break;
1524 
1525 	case SO_BPF_EXTENSIONS:
1526 		v.val = bpf_tell_extensions();
1527 		break;
1528 
1529 	case SO_SELECT_ERR_QUEUE:
1530 		v.val = sock_flag(sk, SOCK_SELECT_ERR_QUEUE);
1531 		break;
1532 
1533 #ifdef CONFIG_NET_RX_BUSY_POLL
1534 	case SO_BUSY_POLL:
1535 		v.val = sk->sk_ll_usec;
1536 		break;
1537 #endif
1538 
1539 	case SO_MAX_PACING_RATE:
1540 		if (sizeof(v.ulval) != sizeof(v.val) && len >= sizeof(v.ulval)) {
1541 			lv = sizeof(v.ulval);
1542 			v.ulval = sk->sk_max_pacing_rate;
1543 		} else {
1544 			/* 32bit version */
1545 			v.val = min_t(unsigned long, sk->sk_max_pacing_rate, ~0U);
1546 		}
1547 		break;
1548 
1549 	case SO_INCOMING_CPU:
1550 		v.val = READ_ONCE(sk->sk_incoming_cpu);
1551 		break;
1552 
1553 	case SO_MEMINFO:
1554 	{
1555 		u32 meminfo[SK_MEMINFO_VARS];
1556 
1557 		sk_get_meminfo(sk, meminfo);
1558 
1559 		len = min_t(unsigned int, len, sizeof(meminfo));
1560 		if (copy_to_user(optval, &meminfo, len))
1561 			return -EFAULT;
1562 
1563 		goto lenout;
1564 	}
1565 
1566 #ifdef CONFIG_NET_RX_BUSY_POLL
1567 	case SO_INCOMING_NAPI_ID:
1568 		v.val = READ_ONCE(sk->sk_napi_id);
1569 
1570 		/* aggregate non-NAPI IDs down to 0 */
1571 		if (v.val < MIN_NAPI_ID)
1572 			v.val = 0;
1573 
1574 		break;
1575 #endif
1576 
1577 	case SO_COOKIE:
1578 		lv = sizeof(u64);
1579 		if (len < lv)
1580 			return -EINVAL;
1581 		v.val64 = sock_gen_cookie(sk);
1582 		break;
1583 
1584 	case SO_ZEROCOPY:
1585 		v.val = sock_flag(sk, SOCK_ZEROCOPY);
1586 		break;
1587 
1588 	case SO_TXTIME:
1589 		lv = sizeof(v.txtime);
1590 		v.txtime.clockid = sk->sk_clockid;
1591 		v.txtime.flags |= sk->sk_txtime_deadline_mode ?
1592 				  SOF_TXTIME_DEADLINE_MODE : 0;
1593 		v.txtime.flags |= sk->sk_txtime_report_errors ?
1594 				  SOF_TXTIME_REPORT_ERRORS : 0;
1595 		break;
1596 
1597 	case SO_BINDTOIFINDEX:
1598 		v.val = sk->sk_bound_dev_if;
1599 		break;
1600 
1601 	default:
1602 		/* We implement the SO_SNDLOWAT etc to not be settable
1603 		 * (1003.1g 7).
1604 		 */
1605 		return -ENOPROTOOPT;
1606 	}
1607 
1608 	if (len > lv)
1609 		len = lv;
1610 	if (copy_to_user(optval, &v, len))
1611 		return -EFAULT;
1612 lenout:
1613 	if (put_user(len, optlen))
1614 		return -EFAULT;
1615 	return 0;
1616 }
1617 
1618 /*
1619  * Initialize an sk_lock.
1620  *
1621  * (We also register the sk_lock with the lock validator.)
1622  */
1623 static inline void sock_lock_init(struct sock *sk)
1624 {
1625 	if (sk->sk_kern_sock)
1626 		sock_lock_init_class_and_name(
1627 			sk,
1628 			af_family_kern_slock_key_strings[sk->sk_family],
1629 			af_family_kern_slock_keys + sk->sk_family,
1630 			af_family_kern_key_strings[sk->sk_family],
1631 			af_family_kern_keys + sk->sk_family);
1632 	else
1633 		sock_lock_init_class_and_name(
1634 			sk,
1635 			af_family_slock_key_strings[sk->sk_family],
1636 			af_family_slock_keys + sk->sk_family,
1637 			af_family_key_strings[sk->sk_family],
1638 			af_family_keys + sk->sk_family);
1639 }
1640 
1641 /*
1642  * Copy all fields from osk to nsk but nsk->sk_refcnt must not change yet,
1643  * even temporarly, because of RCU lookups. sk_node should also be left as is.
1644  * We must not copy fields between sk_dontcopy_begin and sk_dontcopy_end
1645  */
1646 static void sock_copy(struct sock *nsk, const struct sock *osk)
1647 {
1648 	const struct proto *prot = READ_ONCE(osk->sk_prot);
1649 #ifdef CONFIG_SECURITY_NETWORK
1650 	void *sptr = nsk->sk_security;
1651 #endif
1652 	memcpy(nsk, osk, offsetof(struct sock, sk_dontcopy_begin));
1653 
1654 	memcpy(&nsk->sk_dontcopy_end, &osk->sk_dontcopy_end,
1655 	       prot->obj_size - offsetof(struct sock, sk_dontcopy_end));
1656 
1657 #ifdef CONFIG_SECURITY_NETWORK
1658 	nsk->sk_security = sptr;
1659 	security_sk_clone(osk, nsk);
1660 #endif
1661 }
1662 
1663 static struct sock *sk_prot_alloc(struct proto *prot, gfp_t priority,
1664 		int family)
1665 {
1666 	struct sock *sk;
1667 	struct kmem_cache *slab;
1668 
1669 	slab = prot->slab;
1670 	if (slab != NULL) {
1671 		sk = kmem_cache_alloc(slab, priority & ~__GFP_ZERO);
1672 		if (!sk)
1673 			return sk;
1674 		if (want_init_on_alloc(priority))
1675 			sk_prot_clear_nulls(sk, prot->obj_size);
1676 	} else
1677 		sk = kmalloc(prot->obj_size, priority);
1678 
1679 	if (sk != NULL) {
1680 		if (security_sk_alloc(sk, family, priority))
1681 			goto out_free;
1682 
1683 		if (!try_module_get(prot->owner))
1684 			goto out_free_sec;
1685 		sk_tx_queue_clear(sk);
1686 	}
1687 
1688 	return sk;
1689 
1690 out_free_sec:
1691 	security_sk_free(sk);
1692 out_free:
1693 	if (slab != NULL)
1694 		kmem_cache_free(slab, sk);
1695 	else
1696 		kfree(sk);
1697 	return NULL;
1698 }
1699 
1700 static void sk_prot_free(struct proto *prot, struct sock *sk)
1701 {
1702 	struct kmem_cache *slab;
1703 	struct module *owner;
1704 
1705 	owner = prot->owner;
1706 	slab = prot->slab;
1707 
1708 	cgroup_sk_free(&sk->sk_cgrp_data);
1709 	mem_cgroup_sk_free(sk);
1710 	security_sk_free(sk);
1711 	if (slab != NULL)
1712 		kmem_cache_free(slab, sk);
1713 	else
1714 		kfree(sk);
1715 	module_put(owner);
1716 }
1717 
1718 /**
1719  *	sk_alloc - All socket objects are allocated here
1720  *	@net: the applicable net namespace
1721  *	@family: protocol family
1722  *	@priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
1723  *	@prot: struct proto associated with this new sock instance
1724  *	@kern: is this to be a kernel socket?
1725  */
1726 struct sock *sk_alloc(struct net *net, int family, gfp_t priority,
1727 		      struct proto *prot, int kern)
1728 {
1729 	struct sock *sk;
1730 
1731 	sk = sk_prot_alloc(prot, priority | __GFP_ZERO, family);
1732 	if (sk) {
1733 		sk->sk_family = family;
1734 		/*
1735 		 * See comment in struct sock definition to understand
1736 		 * why we need sk_prot_creator -acme
1737 		 */
1738 		sk->sk_prot = sk->sk_prot_creator = prot;
1739 		sk->sk_kern_sock = kern;
1740 		sock_lock_init(sk);
1741 		sk->sk_net_refcnt = kern ? 0 : 1;
1742 		if (likely(sk->sk_net_refcnt)) {
1743 			get_net(net);
1744 			sock_inuse_add(net, 1);
1745 		}
1746 
1747 		sock_net_set(sk, net);
1748 		refcount_set(&sk->sk_wmem_alloc, 1);
1749 
1750 		mem_cgroup_sk_alloc(sk);
1751 		cgroup_sk_alloc(&sk->sk_cgrp_data);
1752 		sock_update_classid(&sk->sk_cgrp_data);
1753 		sock_update_netprioidx(&sk->sk_cgrp_data);
1754 		sk_tx_queue_clear(sk);
1755 	}
1756 
1757 	return sk;
1758 }
1759 EXPORT_SYMBOL(sk_alloc);
1760 
1761 /* Sockets having SOCK_RCU_FREE will call this function after one RCU
1762  * grace period. This is the case for UDP sockets and TCP listeners.
1763  */
1764 static void __sk_destruct(struct rcu_head *head)
1765 {
1766 	struct sock *sk = container_of(head, struct sock, sk_rcu);
1767 	struct sk_filter *filter;
1768 
1769 	if (sk->sk_destruct)
1770 		sk->sk_destruct(sk);
1771 
1772 	filter = rcu_dereference_check(sk->sk_filter,
1773 				       refcount_read(&sk->sk_wmem_alloc) == 0);
1774 	if (filter) {
1775 		sk_filter_uncharge(sk, filter);
1776 		RCU_INIT_POINTER(sk->sk_filter, NULL);
1777 	}
1778 
1779 	sock_disable_timestamp(sk, SK_FLAGS_TIMESTAMP);
1780 
1781 #ifdef CONFIG_BPF_SYSCALL
1782 	bpf_sk_storage_free(sk);
1783 #endif
1784 
1785 	if (atomic_read(&sk->sk_omem_alloc))
1786 		pr_debug("%s: optmem leakage (%d bytes) detected\n",
1787 			 __func__, atomic_read(&sk->sk_omem_alloc));
1788 
1789 	if (sk->sk_frag.page) {
1790 		put_page(sk->sk_frag.page);
1791 		sk->sk_frag.page = NULL;
1792 	}
1793 
1794 	if (sk->sk_peer_cred)
1795 		put_cred(sk->sk_peer_cred);
1796 	put_pid(sk->sk_peer_pid);
1797 	if (likely(sk->sk_net_refcnt))
1798 		put_net(sock_net(sk));
1799 	sk_prot_free(sk->sk_prot_creator, sk);
1800 }
1801 
1802 void sk_destruct(struct sock *sk)
1803 {
1804 	bool use_call_rcu = sock_flag(sk, SOCK_RCU_FREE);
1805 
1806 	if (rcu_access_pointer(sk->sk_reuseport_cb)) {
1807 		reuseport_detach_sock(sk);
1808 		use_call_rcu = true;
1809 	}
1810 
1811 	if (use_call_rcu)
1812 		call_rcu(&sk->sk_rcu, __sk_destruct);
1813 	else
1814 		__sk_destruct(&sk->sk_rcu);
1815 }
1816 
1817 static void __sk_free(struct sock *sk)
1818 {
1819 	if (likely(sk->sk_net_refcnt))
1820 		sock_inuse_add(sock_net(sk), -1);
1821 
1822 	if (unlikely(sk->sk_net_refcnt && sock_diag_has_destroy_listeners(sk)))
1823 		sock_diag_broadcast_destroy(sk);
1824 	else
1825 		sk_destruct(sk);
1826 }
1827 
1828 void sk_free(struct sock *sk)
1829 {
1830 	/*
1831 	 * We subtract one from sk_wmem_alloc and can know if
1832 	 * some packets are still in some tx queue.
1833 	 * If not null, sock_wfree() will call __sk_free(sk) later
1834 	 */
1835 	if (refcount_dec_and_test(&sk->sk_wmem_alloc))
1836 		__sk_free(sk);
1837 }
1838 EXPORT_SYMBOL(sk_free);
1839 
1840 static void sk_init_common(struct sock *sk)
1841 {
1842 	skb_queue_head_init(&sk->sk_receive_queue);
1843 	skb_queue_head_init(&sk->sk_write_queue);
1844 	skb_queue_head_init(&sk->sk_error_queue);
1845 
1846 	rwlock_init(&sk->sk_callback_lock);
1847 	lockdep_set_class_and_name(&sk->sk_receive_queue.lock,
1848 			af_rlock_keys + sk->sk_family,
1849 			af_family_rlock_key_strings[sk->sk_family]);
1850 	lockdep_set_class_and_name(&sk->sk_write_queue.lock,
1851 			af_wlock_keys + sk->sk_family,
1852 			af_family_wlock_key_strings[sk->sk_family]);
1853 	lockdep_set_class_and_name(&sk->sk_error_queue.lock,
1854 			af_elock_keys + sk->sk_family,
1855 			af_family_elock_key_strings[sk->sk_family]);
1856 	lockdep_set_class_and_name(&sk->sk_callback_lock,
1857 			af_callback_keys + sk->sk_family,
1858 			af_family_clock_key_strings[sk->sk_family]);
1859 }
1860 
1861 /**
1862  *	sk_clone_lock - clone a socket, and lock its clone
1863  *	@sk: the socket to clone
1864  *	@priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
1865  *
1866  *	Caller must unlock socket even in error path (bh_unlock_sock(newsk))
1867  */
1868 struct sock *sk_clone_lock(const struct sock *sk, const gfp_t priority)
1869 {
1870 	struct proto *prot = READ_ONCE(sk->sk_prot);
1871 	struct sock *newsk;
1872 	bool is_charged = true;
1873 
1874 	newsk = sk_prot_alloc(prot, priority, sk->sk_family);
1875 	if (newsk != NULL) {
1876 		struct sk_filter *filter;
1877 
1878 		sock_copy(newsk, sk);
1879 
1880 		newsk->sk_prot_creator = prot;
1881 
1882 		/* SANITY */
1883 		if (likely(newsk->sk_net_refcnt))
1884 			get_net(sock_net(newsk));
1885 		sk_node_init(&newsk->sk_node);
1886 		sock_lock_init(newsk);
1887 		bh_lock_sock(newsk);
1888 		newsk->sk_backlog.head	= newsk->sk_backlog.tail = NULL;
1889 		newsk->sk_backlog.len = 0;
1890 
1891 		atomic_set(&newsk->sk_rmem_alloc, 0);
1892 		/*
1893 		 * sk_wmem_alloc set to one (see sk_free() and sock_wfree())
1894 		 */
1895 		refcount_set(&newsk->sk_wmem_alloc, 1);
1896 		atomic_set(&newsk->sk_omem_alloc, 0);
1897 		sk_init_common(newsk);
1898 
1899 		newsk->sk_dst_cache	= NULL;
1900 		newsk->sk_dst_pending_confirm = 0;
1901 		newsk->sk_wmem_queued	= 0;
1902 		newsk->sk_forward_alloc = 0;
1903 		atomic_set(&newsk->sk_drops, 0);
1904 		newsk->sk_send_head	= NULL;
1905 		newsk->sk_userlocks	= sk->sk_userlocks & ~SOCK_BINDPORT_LOCK;
1906 		atomic_set(&newsk->sk_zckey, 0);
1907 
1908 		sock_reset_flag(newsk, SOCK_DONE);
1909 
1910 		/* sk->sk_memcg will be populated at accept() time */
1911 		newsk->sk_memcg = NULL;
1912 
1913 		cgroup_sk_clone(&newsk->sk_cgrp_data);
1914 
1915 		rcu_read_lock();
1916 		filter = rcu_dereference(sk->sk_filter);
1917 		if (filter != NULL)
1918 			/* though it's an empty new sock, the charging may fail
1919 			 * if sysctl_optmem_max was changed between creation of
1920 			 * original socket and cloning
1921 			 */
1922 			is_charged = sk_filter_charge(newsk, filter);
1923 		RCU_INIT_POINTER(newsk->sk_filter, filter);
1924 		rcu_read_unlock();
1925 
1926 		if (unlikely(!is_charged || xfrm_sk_clone_policy(newsk, sk))) {
1927 			/* We need to make sure that we don't uncharge the new
1928 			 * socket if we couldn't charge it in the first place
1929 			 * as otherwise we uncharge the parent's filter.
1930 			 */
1931 			if (!is_charged)
1932 				RCU_INIT_POINTER(newsk->sk_filter, NULL);
1933 			sk_free_unlock_clone(newsk);
1934 			newsk = NULL;
1935 			goto out;
1936 		}
1937 		RCU_INIT_POINTER(newsk->sk_reuseport_cb, NULL);
1938 
1939 		if (bpf_sk_storage_clone(sk, newsk)) {
1940 			sk_free_unlock_clone(newsk);
1941 			newsk = NULL;
1942 			goto out;
1943 		}
1944 
1945 		/* Clear sk_user_data if parent had the pointer tagged
1946 		 * as not suitable for copying when cloning.
1947 		 */
1948 		if (sk_user_data_is_nocopy(newsk))
1949 			newsk->sk_user_data = NULL;
1950 
1951 		newsk->sk_err	   = 0;
1952 		newsk->sk_err_soft = 0;
1953 		newsk->sk_priority = 0;
1954 		newsk->sk_incoming_cpu = raw_smp_processor_id();
1955 		if (likely(newsk->sk_net_refcnt))
1956 			sock_inuse_add(sock_net(newsk), 1);
1957 
1958 		/*
1959 		 * Before updating sk_refcnt, we must commit prior changes to memory
1960 		 * (Documentation/RCU/rculist_nulls.txt for details)
1961 		 */
1962 		smp_wmb();
1963 		refcount_set(&newsk->sk_refcnt, 2);
1964 
1965 		/*
1966 		 * Increment the counter in the same struct proto as the master
1967 		 * sock (sk_refcnt_debug_inc uses newsk->sk_prot->socks, that
1968 		 * is the same as sk->sk_prot->socks, as this field was copied
1969 		 * with memcpy).
1970 		 *
1971 		 * This _changes_ the previous behaviour, where
1972 		 * tcp_create_openreq_child always was incrementing the
1973 		 * equivalent to tcp_prot->socks (inet_sock_nr), so this have
1974 		 * to be taken into account in all callers. -acme
1975 		 */
1976 		sk_refcnt_debug_inc(newsk);
1977 		sk_set_socket(newsk, NULL);
1978 		sk_tx_queue_clear(newsk);
1979 		RCU_INIT_POINTER(newsk->sk_wq, NULL);
1980 
1981 		if (newsk->sk_prot->sockets_allocated)
1982 			sk_sockets_allocated_inc(newsk);
1983 
1984 		if (sock_needs_netstamp(sk) &&
1985 		    newsk->sk_flags & SK_FLAGS_TIMESTAMP)
1986 			net_enable_timestamp();
1987 	}
1988 out:
1989 	return newsk;
1990 }
1991 EXPORT_SYMBOL_GPL(sk_clone_lock);
1992 
1993 void sk_free_unlock_clone(struct sock *sk)
1994 {
1995 	/* It is still raw copy of parent, so invalidate
1996 	 * destructor and make plain sk_free() */
1997 	sk->sk_destruct = NULL;
1998 	bh_unlock_sock(sk);
1999 	sk_free(sk);
2000 }
2001 EXPORT_SYMBOL_GPL(sk_free_unlock_clone);
2002 
2003 void sk_setup_caps(struct sock *sk, struct dst_entry *dst)
2004 {
2005 	u32 max_segs = 1;
2006 
2007 	sk_dst_set(sk, dst);
2008 	sk->sk_route_caps = dst->dev->features | sk->sk_route_forced_caps;
2009 	if (sk->sk_route_caps & NETIF_F_GSO)
2010 		sk->sk_route_caps |= NETIF_F_GSO_SOFTWARE;
2011 	sk->sk_route_caps &= ~sk->sk_route_nocaps;
2012 	if (sk_can_gso(sk)) {
2013 		if (dst->header_len && !xfrm_dst_offload_ok(dst)) {
2014 			sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
2015 		} else {
2016 			sk->sk_route_caps |= NETIF_F_SG | NETIF_F_HW_CSUM;
2017 			sk->sk_gso_max_size = dst->dev->gso_max_size;
2018 			max_segs = max_t(u32, dst->dev->gso_max_segs, 1);
2019 		}
2020 	}
2021 	sk->sk_gso_max_segs = max_segs;
2022 }
2023 EXPORT_SYMBOL_GPL(sk_setup_caps);
2024 
2025 /*
2026  *	Simple resource managers for sockets.
2027  */
2028 
2029 
2030 /*
2031  * Write buffer destructor automatically called from kfree_skb.
2032  */
2033 void sock_wfree(struct sk_buff *skb)
2034 {
2035 	struct sock *sk = skb->sk;
2036 	unsigned int len = skb->truesize;
2037 
2038 	if (!sock_flag(sk, SOCK_USE_WRITE_QUEUE)) {
2039 		/*
2040 		 * Keep a reference on sk_wmem_alloc, this will be released
2041 		 * after sk_write_space() call
2042 		 */
2043 		WARN_ON(refcount_sub_and_test(len - 1, &sk->sk_wmem_alloc));
2044 		sk->sk_write_space(sk);
2045 		len = 1;
2046 	}
2047 	/*
2048 	 * if sk_wmem_alloc reaches 0, we must finish what sk_free()
2049 	 * could not do because of in-flight packets
2050 	 */
2051 	if (refcount_sub_and_test(len, &sk->sk_wmem_alloc))
2052 		__sk_free(sk);
2053 }
2054 EXPORT_SYMBOL(sock_wfree);
2055 
2056 /* This variant of sock_wfree() is used by TCP,
2057  * since it sets SOCK_USE_WRITE_QUEUE.
2058  */
2059 void __sock_wfree(struct sk_buff *skb)
2060 {
2061 	struct sock *sk = skb->sk;
2062 
2063 	if (refcount_sub_and_test(skb->truesize, &sk->sk_wmem_alloc))
2064 		__sk_free(sk);
2065 }
2066 
2067 void skb_set_owner_w(struct sk_buff *skb, struct sock *sk)
2068 {
2069 	skb_orphan(skb);
2070 	skb->sk = sk;
2071 #ifdef CONFIG_INET
2072 	if (unlikely(!sk_fullsock(sk))) {
2073 		skb->destructor = sock_edemux;
2074 		sock_hold(sk);
2075 		return;
2076 	}
2077 #endif
2078 	skb->destructor = sock_wfree;
2079 	skb_set_hash_from_sk(skb, sk);
2080 	/*
2081 	 * We used to take a refcount on sk, but following operation
2082 	 * is enough to guarantee sk_free() wont free this sock until
2083 	 * all in-flight packets are completed
2084 	 */
2085 	refcount_add(skb->truesize, &sk->sk_wmem_alloc);
2086 }
2087 EXPORT_SYMBOL(skb_set_owner_w);
2088 
2089 static bool can_skb_orphan_partial(const struct sk_buff *skb)
2090 {
2091 #ifdef CONFIG_TLS_DEVICE
2092 	/* Drivers depend on in-order delivery for crypto offload,
2093 	 * partial orphan breaks out-of-order-OK logic.
2094 	 */
2095 	if (skb->decrypted)
2096 		return false;
2097 #endif
2098 	return (skb->destructor == sock_wfree ||
2099 		(IS_ENABLED(CONFIG_INET) && skb->destructor == tcp_wfree));
2100 }
2101 
2102 /* This helper is used by netem, as it can hold packets in its
2103  * delay queue. We want to allow the owner socket to send more
2104  * packets, as if they were already TX completed by a typical driver.
2105  * But we also want to keep skb->sk set because some packet schedulers
2106  * rely on it (sch_fq for example).
2107  */
2108 void skb_orphan_partial(struct sk_buff *skb)
2109 {
2110 	if (skb_is_tcp_pure_ack(skb))
2111 		return;
2112 
2113 	if (can_skb_orphan_partial(skb)) {
2114 		struct sock *sk = skb->sk;
2115 
2116 		if (refcount_inc_not_zero(&sk->sk_refcnt)) {
2117 			WARN_ON(refcount_sub_and_test(skb->truesize, &sk->sk_wmem_alloc));
2118 			skb->destructor = sock_efree;
2119 		}
2120 	} else {
2121 		skb_orphan(skb);
2122 	}
2123 }
2124 EXPORT_SYMBOL(skb_orphan_partial);
2125 
2126 /*
2127  * Read buffer destructor automatically called from kfree_skb.
2128  */
2129 void sock_rfree(struct sk_buff *skb)
2130 {
2131 	struct sock *sk = skb->sk;
2132 	unsigned int len = skb->truesize;
2133 
2134 	atomic_sub(len, &sk->sk_rmem_alloc);
2135 	sk_mem_uncharge(sk, len);
2136 }
2137 EXPORT_SYMBOL(sock_rfree);
2138 
2139 /*
2140  * Buffer destructor for skbs that are not used directly in read or write
2141  * path, e.g. for error handler skbs. Automatically called from kfree_skb.
2142  */
2143 void sock_efree(struct sk_buff *skb)
2144 {
2145 	sock_put(skb->sk);
2146 }
2147 EXPORT_SYMBOL(sock_efree);
2148 
2149 /* Buffer destructor for prefetch/receive path where reference count may
2150  * not be held, e.g. for listen sockets.
2151  */
2152 #ifdef CONFIG_INET
2153 void sock_pfree(struct sk_buff *skb)
2154 {
2155 	if (sk_is_refcounted(skb->sk))
2156 		sock_gen_put(skb->sk);
2157 }
2158 EXPORT_SYMBOL(sock_pfree);
2159 #endif /* CONFIG_INET */
2160 
2161 kuid_t sock_i_uid(struct sock *sk)
2162 {
2163 	kuid_t uid;
2164 
2165 	read_lock_bh(&sk->sk_callback_lock);
2166 	uid = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_uid : GLOBAL_ROOT_UID;
2167 	read_unlock_bh(&sk->sk_callback_lock);
2168 	return uid;
2169 }
2170 EXPORT_SYMBOL(sock_i_uid);
2171 
2172 unsigned long sock_i_ino(struct sock *sk)
2173 {
2174 	unsigned long ino;
2175 
2176 	read_lock_bh(&sk->sk_callback_lock);
2177 	ino = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_ino : 0;
2178 	read_unlock_bh(&sk->sk_callback_lock);
2179 	return ino;
2180 }
2181 EXPORT_SYMBOL(sock_i_ino);
2182 
2183 /*
2184  * Allocate a skb from the socket's send buffer.
2185  */
2186 struct sk_buff *sock_wmalloc(struct sock *sk, unsigned long size, int force,
2187 			     gfp_t priority)
2188 {
2189 	if (force ||
2190 	    refcount_read(&sk->sk_wmem_alloc) < READ_ONCE(sk->sk_sndbuf)) {
2191 		struct sk_buff *skb = alloc_skb(size, priority);
2192 
2193 		if (skb) {
2194 			skb_set_owner_w(skb, sk);
2195 			return skb;
2196 		}
2197 	}
2198 	return NULL;
2199 }
2200 EXPORT_SYMBOL(sock_wmalloc);
2201 
2202 static void sock_ofree(struct sk_buff *skb)
2203 {
2204 	struct sock *sk = skb->sk;
2205 
2206 	atomic_sub(skb->truesize, &sk->sk_omem_alloc);
2207 }
2208 
2209 struct sk_buff *sock_omalloc(struct sock *sk, unsigned long size,
2210 			     gfp_t priority)
2211 {
2212 	struct sk_buff *skb;
2213 
2214 	/* small safe race: SKB_TRUESIZE may differ from final skb->truesize */
2215 	if (atomic_read(&sk->sk_omem_alloc) + SKB_TRUESIZE(size) >
2216 	    sysctl_optmem_max)
2217 		return NULL;
2218 
2219 	skb = alloc_skb(size, priority);
2220 	if (!skb)
2221 		return NULL;
2222 
2223 	atomic_add(skb->truesize, &sk->sk_omem_alloc);
2224 	skb->sk = sk;
2225 	skb->destructor = sock_ofree;
2226 	return skb;
2227 }
2228 
2229 /*
2230  * Allocate a memory block from the socket's option memory buffer.
2231  */
2232 void *sock_kmalloc(struct sock *sk, int size, gfp_t priority)
2233 {
2234 	if ((unsigned int)size <= sysctl_optmem_max &&
2235 	    atomic_read(&sk->sk_omem_alloc) + size < sysctl_optmem_max) {
2236 		void *mem;
2237 		/* First do the add, to avoid the race if kmalloc
2238 		 * might sleep.
2239 		 */
2240 		atomic_add(size, &sk->sk_omem_alloc);
2241 		mem = kmalloc(size, priority);
2242 		if (mem)
2243 			return mem;
2244 		atomic_sub(size, &sk->sk_omem_alloc);
2245 	}
2246 	return NULL;
2247 }
2248 EXPORT_SYMBOL(sock_kmalloc);
2249 
2250 /* Free an option memory block. Note, we actually want the inline
2251  * here as this allows gcc to detect the nullify and fold away the
2252  * condition entirely.
2253  */
2254 static inline void __sock_kfree_s(struct sock *sk, void *mem, int size,
2255 				  const bool nullify)
2256 {
2257 	if (WARN_ON_ONCE(!mem))
2258 		return;
2259 	if (nullify)
2260 		kzfree(mem);
2261 	else
2262 		kfree(mem);
2263 	atomic_sub(size, &sk->sk_omem_alloc);
2264 }
2265 
2266 void sock_kfree_s(struct sock *sk, void *mem, int size)
2267 {
2268 	__sock_kfree_s(sk, mem, size, false);
2269 }
2270 EXPORT_SYMBOL(sock_kfree_s);
2271 
2272 void sock_kzfree_s(struct sock *sk, void *mem, int size)
2273 {
2274 	__sock_kfree_s(sk, mem, size, true);
2275 }
2276 EXPORT_SYMBOL(sock_kzfree_s);
2277 
2278 /* It is almost wait_for_tcp_memory minus release_sock/lock_sock.
2279    I think, these locks should be removed for datagram sockets.
2280  */
2281 static long sock_wait_for_wmem(struct sock *sk, long timeo)
2282 {
2283 	DEFINE_WAIT(wait);
2284 
2285 	sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
2286 	for (;;) {
2287 		if (!timeo)
2288 			break;
2289 		if (signal_pending(current))
2290 			break;
2291 		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
2292 		prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
2293 		if (refcount_read(&sk->sk_wmem_alloc) < READ_ONCE(sk->sk_sndbuf))
2294 			break;
2295 		if (sk->sk_shutdown & SEND_SHUTDOWN)
2296 			break;
2297 		if (sk->sk_err)
2298 			break;
2299 		timeo = schedule_timeout(timeo);
2300 	}
2301 	finish_wait(sk_sleep(sk), &wait);
2302 	return timeo;
2303 }
2304 
2305 
2306 /*
2307  *	Generic send/receive buffer handlers
2308  */
2309 
2310 struct sk_buff *sock_alloc_send_pskb(struct sock *sk, unsigned long header_len,
2311 				     unsigned long data_len, int noblock,
2312 				     int *errcode, int max_page_order)
2313 {
2314 	struct sk_buff *skb;
2315 	long timeo;
2316 	int err;
2317 
2318 	timeo = sock_sndtimeo(sk, noblock);
2319 	for (;;) {
2320 		err = sock_error(sk);
2321 		if (err != 0)
2322 			goto failure;
2323 
2324 		err = -EPIPE;
2325 		if (sk->sk_shutdown & SEND_SHUTDOWN)
2326 			goto failure;
2327 
2328 		if (sk_wmem_alloc_get(sk) < READ_ONCE(sk->sk_sndbuf))
2329 			break;
2330 
2331 		sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
2332 		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
2333 		err = -EAGAIN;
2334 		if (!timeo)
2335 			goto failure;
2336 		if (signal_pending(current))
2337 			goto interrupted;
2338 		timeo = sock_wait_for_wmem(sk, timeo);
2339 	}
2340 	skb = alloc_skb_with_frags(header_len, data_len, max_page_order,
2341 				   errcode, sk->sk_allocation);
2342 	if (skb)
2343 		skb_set_owner_w(skb, sk);
2344 	return skb;
2345 
2346 interrupted:
2347 	err = sock_intr_errno(timeo);
2348 failure:
2349 	*errcode = err;
2350 	return NULL;
2351 }
2352 EXPORT_SYMBOL(sock_alloc_send_pskb);
2353 
2354 struct sk_buff *sock_alloc_send_skb(struct sock *sk, unsigned long size,
2355 				    int noblock, int *errcode)
2356 {
2357 	return sock_alloc_send_pskb(sk, size, 0, noblock, errcode, 0);
2358 }
2359 EXPORT_SYMBOL(sock_alloc_send_skb);
2360 
2361 int __sock_cmsg_send(struct sock *sk, struct msghdr *msg, struct cmsghdr *cmsg,
2362 		     struct sockcm_cookie *sockc)
2363 {
2364 	u32 tsflags;
2365 
2366 	switch (cmsg->cmsg_type) {
2367 	case SO_MARK:
2368 		if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
2369 			return -EPERM;
2370 		if (cmsg->cmsg_len != CMSG_LEN(sizeof(u32)))
2371 			return -EINVAL;
2372 		sockc->mark = *(u32 *)CMSG_DATA(cmsg);
2373 		break;
2374 	case SO_TIMESTAMPING_OLD:
2375 		if (cmsg->cmsg_len != CMSG_LEN(sizeof(u32)))
2376 			return -EINVAL;
2377 
2378 		tsflags = *(u32 *)CMSG_DATA(cmsg);
2379 		if (tsflags & ~SOF_TIMESTAMPING_TX_RECORD_MASK)
2380 			return -EINVAL;
2381 
2382 		sockc->tsflags &= ~SOF_TIMESTAMPING_TX_RECORD_MASK;
2383 		sockc->tsflags |= tsflags;
2384 		break;
2385 	case SCM_TXTIME:
2386 		if (!sock_flag(sk, SOCK_TXTIME))
2387 			return -EINVAL;
2388 		if (cmsg->cmsg_len != CMSG_LEN(sizeof(u64)))
2389 			return -EINVAL;
2390 		sockc->transmit_time = get_unaligned((u64 *)CMSG_DATA(cmsg));
2391 		break;
2392 	/* SCM_RIGHTS and SCM_CREDENTIALS are semantically in SOL_UNIX. */
2393 	case SCM_RIGHTS:
2394 	case SCM_CREDENTIALS:
2395 		break;
2396 	default:
2397 		return -EINVAL;
2398 	}
2399 	return 0;
2400 }
2401 EXPORT_SYMBOL(__sock_cmsg_send);
2402 
2403 int sock_cmsg_send(struct sock *sk, struct msghdr *msg,
2404 		   struct sockcm_cookie *sockc)
2405 {
2406 	struct cmsghdr *cmsg;
2407 	int ret;
2408 
2409 	for_each_cmsghdr(cmsg, msg) {
2410 		if (!CMSG_OK(msg, cmsg))
2411 			return -EINVAL;
2412 		if (cmsg->cmsg_level != SOL_SOCKET)
2413 			continue;
2414 		ret = __sock_cmsg_send(sk, msg, cmsg, sockc);
2415 		if (ret)
2416 			return ret;
2417 	}
2418 	return 0;
2419 }
2420 EXPORT_SYMBOL(sock_cmsg_send);
2421 
2422 static void sk_enter_memory_pressure(struct sock *sk)
2423 {
2424 	if (!sk->sk_prot->enter_memory_pressure)
2425 		return;
2426 
2427 	sk->sk_prot->enter_memory_pressure(sk);
2428 }
2429 
2430 static void sk_leave_memory_pressure(struct sock *sk)
2431 {
2432 	if (sk->sk_prot->leave_memory_pressure) {
2433 		sk->sk_prot->leave_memory_pressure(sk);
2434 	} else {
2435 		unsigned long *memory_pressure = sk->sk_prot->memory_pressure;
2436 
2437 		if (memory_pressure && READ_ONCE(*memory_pressure))
2438 			WRITE_ONCE(*memory_pressure, 0);
2439 	}
2440 }
2441 
2442 #define SKB_FRAG_PAGE_ORDER	get_order(32768)
2443 DEFINE_STATIC_KEY_FALSE(net_high_order_alloc_disable_key);
2444 
2445 /**
2446  * skb_page_frag_refill - check that a page_frag contains enough room
2447  * @sz: minimum size of the fragment we want to get
2448  * @pfrag: pointer to page_frag
2449  * @gfp: priority for memory allocation
2450  *
2451  * Note: While this allocator tries to use high order pages, there is
2452  * no guarantee that allocations succeed. Therefore, @sz MUST be
2453  * less or equal than PAGE_SIZE.
2454  */
2455 bool skb_page_frag_refill(unsigned int sz, struct page_frag *pfrag, gfp_t gfp)
2456 {
2457 	if (pfrag->page) {
2458 		if (page_ref_count(pfrag->page) == 1) {
2459 			pfrag->offset = 0;
2460 			return true;
2461 		}
2462 		if (pfrag->offset + sz <= pfrag->size)
2463 			return true;
2464 		put_page(pfrag->page);
2465 	}
2466 
2467 	pfrag->offset = 0;
2468 	if (SKB_FRAG_PAGE_ORDER &&
2469 	    !static_branch_unlikely(&net_high_order_alloc_disable_key)) {
2470 		/* Avoid direct reclaim but allow kswapd to wake */
2471 		pfrag->page = alloc_pages((gfp & ~__GFP_DIRECT_RECLAIM) |
2472 					  __GFP_COMP | __GFP_NOWARN |
2473 					  __GFP_NORETRY,
2474 					  SKB_FRAG_PAGE_ORDER);
2475 		if (likely(pfrag->page)) {
2476 			pfrag->size = PAGE_SIZE << SKB_FRAG_PAGE_ORDER;
2477 			return true;
2478 		}
2479 	}
2480 	pfrag->page = alloc_page(gfp);
2481 	if (likely(pfrag->page)) {
2482 		pfrag->size = PAGE_SIZE;
2483 		return true;
2484 	}
2485 	return false;
2486 }
2487 EXPORT_SYMBOL(skb_page_frag_refill);
2488 
2489 bool sk_page_frag_refill(struct sock *sk, struct page_frag *pfrag)
2490 {
2491 	if (likely(skb_page_frag_refill(32U, pfrag, sk->sk_allocation)))
2492 		return true;
2493 
2494 	sk_enter_memory_pressure(sk);
2495 	sk_stream_moderate_sndbuf(sk);
2496 	return false;
2497 }
2498 EXPORT_SYMBOL(sk_page_frag_refill);
2499 
2500 static void __lock_sock(struct sock *sk)
2501 	__releases(&sk->sk_lock.slock)
2502 	__acquires(&sk->sk_lock.slock)
2503 {
2504 	DEFINE_WAIT(wait);
2505 
2506 	for (;;) {
2507 		prepare_to_wait_exclusive(&sk->sk_lock.wq, &wait,
2508 					TASK_UNINTERRUPTIBLE);
2509 		spin_unlock_bh(&sk->sk_lock.slock);
2510 		schedule();
2511 		spin_lock_bh(&sk->sk_lock.slock);
2512 		if (!sock_owned_by_user(sk))
2513 			break;
2514 	}
2515 	finish_wait(&sk->sk_lock.wq, &wait);
2516 }
2517 
2518 void __release_sock(struct sock *sk)
2519 	__releases(&sk->sk_lock.slock)
2520 	__acquires(&sk->sk_lock.slock)
2521 {
2522 	struct sk_buff *skb, *next;
2523 
2524 	while ((skb = sk->sk_backlog.head) != NULL) {
2525 		sk->sk_backlog.head = sk->sk_backlog.tail = NULL;
2526 
2527 		spin_unlock_bh(&sk->sk_lock.slock);
2528 
2529 		do {
2530 			next = skb->next;
2531 			prefetch(next);
2532 			WARN_ON_ONCE(skb_dst_is_noref(skb));
2533 			skb_mark_not_on_list(skb);
2534 			sk_backlog_rcv(sk, skb);
2535 
2536 			cond_resched();
2537 
2538 			skb = next;
2539 		} while (skb != NULL);
2540 
2541 		spin_lock_bh(&sk->sk_lock.slock);
2542 	}
2543 
2544 	/*
2545 	 * Doing the zeroing here guarantee we can not loop forever
2546 	 * while a wild producer attempts to flood us.
2547 	 */
2548 	sk->sk_backlog.len = 0;
2549 }
2550 
2551 void __sk_flush_backlog(struct sock *sk)
2552 {
2553 	spin_lock_bh(&sk->sk_lock.slock);
2554 	__release_sock(sk);
2555 	spin_unlock_bh(&sk->sk_lock.slock);
2556 }
2557 
2558 /**
2559  * sk_wait_data - wait for data to arrive at sk_receive_queue
2560  * @sk:    sock to wait on
2561  * @timeo: for how long
2562  * @skb:   last skb seen on sk_receive_queue
2563  *
2564  * Now socket state including sk->sk_err is changed only under lock,
2565  * hence we may omit checks after joining wait queue.
2566  * We check receive queue before schedule() only as optimization;
2567  * it is very likely that release_sock() added new data.
2568  */
2569 int sk_wait_data(struct sock *sk, long *timeo, const struct sk_buff *skb)
2570 {
2571 	DEFINE_WAIT_FUNC(wait, woken_wake_function);
2572 	int rc;
2573 
2574 	add_wait_queue(sk_sleep(sk), &wait);
2575 	sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
2576 	rc = sk_wait_event(sk, timeo, skb_peek_tail(&sk->sk_receive_queue) != skb, &wait);
2577 	sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
2578 	remove_wait_queue(sk_sleep(sk), &wait);
2579 	return rc;
2580 }
2581 EXPORT_SYMBOL(sk_wait_data);
2582 
2583 /**
2584  *	__sk_mem_raise_allocated - increase memory_allocated
2585  *	@sk: socket
2586  *	@size: memory size to allocate
2587  *	@amt: pages to allocate
2588  *	@kind: allocation type
2589  *
2590  *	Similar to __sk_mem_schedule(), but does not update sk_forward_alloc
2591  */
2592 int __sk_mem_raise_allocated(struct sock *sk, int size, int amt, int kind)
2593 {
2594 	struct proto *prot = sk->sk_prot;
2595 	long allocated = sk_memory_allocated_add(sk, amt);
2596 	bool charged = true;
2597 
2598 	if (mem_cgroup_sockets_enabled && sk->sk_memcg &&
2599 	    !(charged = mem_cgroup_charge_skmem(sk->sk_memcg, amt)))
2600 		goto suppress_allocation;
2601 
2602 	/* Under limit. */
2603 	if (allocated <= sk_prot_mem_limits(sk, 0)) {
2604 		sk_leave_memory_pressure(sk);
2605 		return 1;
2606 	}
2607 
2608 	/* Under pressure. */
2609 	if (allocated > sk_prot_mem_limits(sk, 1))
2610 		sk_enter_memory_pressure(sk);
2611 
2612 	/* Over hard limit. */
2613 	if (allocated > sk_prot_mem_limits(sk, 2))
2614 		goto suppress_allocation;
2615 
2616 	/* guarantee minimum buffer size under pressure */
2617 	if (kind == SK_MEM_RECV) {
2618 		if (atomic_read(&sk->sk_rmem_alloc) < sk_get_rmem0(sk, prot))
2619 			return 1;
2620 
2621 	} else { /* SK_MEM_SEND */
2622 		int wmem0 = sk_get_wmem0(sk, prot);
2623 
2624 		if (sk->sk_type == SOCK_STREAM) {
2625 			if (sk->sk_wmem_queued < wmem0)
2626 				return 1;
2627 		} else if (refcount_read(&sk->sk_wmem_alloc) < wmem0) {
2628 				return 1;
2629 		}
2630 	}
2631 
2632 	if (sk_has_memory_pressure(sk)) {
2633 		u64 alloc;
2634 
2635 		if (!sk_under_memory_pressure(sk))
2636 			return 1;
2637 		alloc = sk_sockets_allocated_read_positive(sk);
2638 		if (sk_prot_mem_limits(sk, 2) > alloc *
2639 		    sk_mem_pages(sk->sk_wmem_queued +
2640 				 atomic_read(&sk->sk_rmem_alloc) +
2641 				 sk->sk_forward_alloc))
2642 			return 1;
2643 	}
2644 
2645 suppress_allocation:
2646 
2647 	if (kind == SK_MEM_SEND && sk->sk_type == SOCK_STREAM) {
2648 		sk_stream_moderate_sndbuf(sk);
2649 
2650 		/* Fail only if socket is _under_ its sndbuf.
2651 		 * In this case we cannot block, so that we have to fail.
2652 		 */
2653 		if (sk->sk_wmem_queued + size >= sk->sk_sndbuf)
2654 			return 1;
2655 	}
2656 
2657 	if (kind == SK_MEM_SEND || (kind == SK_MEM_RECV && charged))
2658 		trace_sock_exceed_buf_limit(sk, prot, allocated, kind);
2659 
2660 	sk_memory_allocated_sub(sk, amt);
2661 
2662 	if (mem_cgroup_sockets_enabled && sk->sk_memcg)
2663 		mem_cgroup_uncharge_skmem(sk->sk_memcg, amt);
2664 
2665 	return 0;
2666 }
2667 EXPORT_SYMBOL(__sk_mem_raise_allocated);
2668 
2669 /**
2670  *	__sk_mem_schedule - increase sk_forward_alloc and memory_allocated
2671  *	@sk: socket
2672  *	@size: memory size to allocate
2673  *	@kind: allocation type
2674  *
2675  *	If kind is SK_MEM_SEND, it means wmem allocation. Otherwise it means
2676  *	rmem allocation. This function assumes that protocols which have
2677  *	memory_pressure use sk_wmem_queued as write buffer accounting.
2678  */
2679 int __sk_mem_schedule(struct sock *sk, int size, int kind)
2680 {
2681 	int ret, amt = sk_mem_pages(size);
2682 
2683 	sk->sk_forward_alloc += amt << SK_MEM_QUANTUM_SHIFT;
2684 	ret = __sk_mem_raise_allocated(sk, size, amt, kind);
2685 	if (!ret)
2686 		sk->sk_forward_alloc -= amt << SK_MEM_QUANTUM_SHIFT;
2687 	return ret;
2688 }
2689 EXPORT_SYMBOL(__sk_mem_schedule);
2690 
2691 /**
2692  *	__sk_mem_reduce_allocated - reclaim memory_allocated
2693  *	@sk: socket
2694  *	@amount: number of quanta
2695  *
2696  *	Similar to __sk_mem_reclaim(), but does not update sk_forward_alloc
2697  */
2698 void __sk_mem_reduce_allocated(struct sock *sk, int amount)
2699 {
2700 	sk_memory_allocated_sub(sk, amount);
2701 
2702 	if (mem_cgroup_sockets_enabled && sk->sk_memcg)
2703 		mem_cgroup_uncharge_skmem(sk->sk_memcg, amount);
2704 
2705 	if (sk_under_memory_pressure(sk) &&
2706 	    (sk_memory_allocated(sk) < sk_prot_mem_limits(sk, 0)))
2707 		sk_leave_memory_pressure(sk);
2708 }
2709 EXPORT_SYMBOL(__sk_mem_reduce_allocated);
2710 
2711 /**
2712  *	__sk_mem_reclaim - reclaim sk_forward_alloc and memory_allocated
2713  *	@sk: socket
2714  *	@amount: number of bytes (rounded down to a SK_MEM_QUANTUM multiple)
2715  */
2716 void __sk_mem_reclaim(struct sock *sk, int amount)
2717 {
2718 	amount >>= SK_MEM_QUANTUM_SHIFT;
2719 	sk->sk_forward_alloc -= amount << SK_MEM_QUANTUM_SHIFT;
2720 	__sk_mem_reduce_allocated(sk, amount);
2721 }
2722 EXPORT_SYMBOL(__sk_mem_reclaim);
2723 
2724 int sk_set_peek_off(struct sock *sk, int val)
2725 {
2726 	sk->sk_peek_off = val;
2727 	return 0;
2728 }
2729 EXPORT_SYMBOL_GPL(sk_set_peek_off);
2730 
2731 /*
2732  * Set of default routines for initialising struct proto_ops when
2733  * the protocol does not support a particular function. In certain
2734  * cases where it makes no sense for a protocol to have a "do nothing"
2735  * function, some default processing is provided.
2736  */
2737 
2738 int sock_no_bind(struct socket *sock, struct sockaddr *saddr, int len)
2739 {
2740 	return -EOPNOTSUPP;
2741 }
2742 EXPORT_SYMBOL(sock_no_bind);
2743 
2744 int sock_no_connect(struct socket *sock, struct sockaddr *saddr,
2745 		    int len, int flags)
2746 {
2747 	return -EOPNOTSUPP;
2748 }
2749 EXPORT_SYMBOL(sock_no_connect);
2750 
2751 int sock_no_socketpair(struct socket *sock1, struct socket *sock2)
2752 {
2753 	return -EOPNOTSUPP;
2754 }
2755 EXPORT_SYMBOL(sock_no_socketpair);
2756 
2757 int sock_no_accept(struct socket *sock, struct socket *newsock, int flags,
2758 		   bool kern)
2759 {
2760 	return -EOPNOTSUPP;
2761 }
2762 EXPORT_SYMBOL(sock_no_accept);
2763 
2764 int sock_no_getname(struct socket *sock, struct sockaddr *saddr,
2765 		    int peer)
2766 {
2767 	return -EOPNOTSUPP;
2768 }
2769 EXPORT_SYMBOL(sock_no_getname);
2770 
2771 int sock_no_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
2772 {
2773 	return -EOPNOTSUPP;
2774 }
2775 EXPORT_SYMBOL(sock_no_ioctl);
2776 
2777 int sock_no_listen(struct socket *sock, int backlog)
2778 {
2779 	return -EOPNOTSUPP;
2780 }
2781 EXPORT_SYMBOL(sock_no_listen);
2782 
2783 int sock_no_shutdown(struct socket *sock, int how)
2784 {
2785 	return -EOPNOTSUPP;
2786 }
2787 EXPORT_SYMBOL(sock_no_shutdown);
2788 
2789 int sock_no_sendmsg(struct socket *sock, struct msghdr *m, size_t len)
2790 {
2791 	return -EOPNOTSUPP;
2792 }
2793 EXPORT_SYMBOL(sock_no_sendmsg);
2794 
2795 int sock_no_sendmsg_locked(struct sock *sk, struct msghdr *m, size_t len)
2796 {
2797 	return -EOPNOTSUPP;
2798 }
2799 EXPORT_SYMBOL(sock_no_sendmsg_locked);
2800 
2801 int sock_no_recvmsg(struct socket *sock, struct msghdr *m, size_t len,
2802 		    int flags)
2803 {
2804 	return -EOPNOTSUPP;
2805 }
2806 EXPORT_SYMBOL(sock_no_recvmsg);
2807 
2808 int sock_no_mmap(struct file *file, struct socket *sock, struct vm_area_struct *vma)
2809 {
2810 	/* Mirror missing mmap method error code */
2811 	return -ENODEV;
2812 }
2813 EXPORT_SYMBOL(sock_no_mmap);
2814 
2815 ssize_t sock_no_sendpage(struct socket *sock, struct page *page, int offset, size_t size, int flags)
2816 {
2817 	ssize_t res;
2818 	struct msghdr msg = {.msg_flags = flags};
2819 	struct kvec iov;
2820 	char *kaddr = kmap(page);
2821 	iov.iov_base = kaddr + offset;
2822 	iov.iov_len = size;
2823 	res = kernel_sendmsg(sock, &msg, &iov, 1, size);
2824 	kunmap(page);
2825 	return res;
2826 }
2827 EXPORT_SYMBOL(sock_no_sendpage);
2828 
2829 ssize_t sock_no_sendpage_locked(struct sock *sk, struct page *page,
2830 				int offset, size_t size, int flags)
2831 {
2832 	ssize_t res;
2833 	struct msghdr msg = {.msg_flags = flags};
2834 	struct kvec iov;
2835 	char *kaddr = kmap(page);
2836 
2837 	iov.iov_base = kaddr + offset;
2838 	iov.iov_len = size;
2839 	res = kernel_sendmsg_locked(sk, &msg, &iov, 1, size);
2840 	kunmap(page);
2841 	return res;
2842 }
2843 EXPORT_SYMBOL(sock_no_sendpage_locked);
2844 
2845 /*
2846  *	Default Socket Callbacks
2847  */
2848 
2849 static void sock_def_wakeup(struct sock *sk)
2850 {
2851 	struct socket_wq *wq;
2852 
2853 	rcu_read_lock();
2854 	wq = rcu_dereference(sk->sk_wq);
2855 	if (skwq_has_sleeper(wq))
2856 		wake_up_interruptible_all(&wq->wait);
2857 	rcu_read_unlock();
2858 }
2859 
2860 static void sock_def_error_report(struct sock *sk)
2861 {
2862 	struct socket_wq *wq;
2863 
2864 	rcu_read_lock();
2865 	wq = rcu_dereference(sk->sk_wq);
2866 	if (skwq_has_sleeper(wq))
2867 		wake_up_interruptible_poll(&wq->wait, EPOLLERR);
2868 	sk_wake_async(sk, SOCK_WAKE_IO, POLL_ERR);
2869 	rcu_read_unlock();
2870 }
2871 
2872 void sock_def_readable(struct sock *sk)
2873 {
2874 	struct socket_wq *wq;
2875 
2876 	rcu_read_lock();
2877 	wq = rcu_dereference(sk->sk_wq);
2878 	if (skwq_has_sleeper(wq))
2879 		wake_up_interruptible_sync_poll(&wq->wait, EPOLLIN | EPOLLPRI |
2880 						EPOLLRDNORM | EPOLLRDBAND);
2881 	sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
2882 	rcu_read_unlock();
2883 }
2884 
2885 static void sock_def_write_space(struct sock *sk)
2886 {
2887 	struct socket_wq *wq;
2888 
2889 	rcu_read_lock();
2890 
2891 	/* Do not wake up a writer until he can make "significant"
2892 	 * progress.  --DaveM
2893 	 */
2894 	if ((refcount_read(&sk->sk_wmem_alloc) << 1) <= READ_ONCE(sk->sk_sndbuf)) {
2895 		wq = rcu_dereference(sk->sk_wq);
2896 		if (skwq_has_sleeper(wq))
2897 			wake_up_interruptible_sync_poll(&wq->wait, EPOLLOUT |
2898 						EPOLLWRNORM | EPOLLWRBAND);
2899 
2900 		/* Should agree with poll, otherwise some programs break */
2901 		if (sock_writeable(sk))
2902 			sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
2903 	}
2904 
2905 	rcu_read_unlock();
2906 }
2907 
2908 static void sock_def_destruct(struct sock *sk)
2909 {
2910 }
2911 
2912 void sk_send_sigurg(struct sock *sk)
2913 {
2914 	if (sk->sk_socket && sk->sk_socket->file)
2915 		if (send_sigurg(&sk->sk_socket->file->f_owner))
2916 			sk_wake_async(sk, SOCK_WAKE_URG, POLL_PRI);
2917 }
2918 EXPORT_SYMBOL(sk_send_sigurg);
2919 
2920 void sk_reset_timer(struct sock *sk, struct timer_list* timer,
2921 		    unsigned long expires)
2922 {
2923 	if (!mod_timer(timer, expires))
2924 		sock_hold(sk);
2925 }
2926 EXPORT_SYMBOL(sk_reset_timer);
2927 
2928 void sk_stop_timer(struct sock *sk, struct timer_list* timer)
2929 {
2930 	if (del_timer(timer))
2931 		__sock_put(sk);
2932 }
2933 EXPORT_SYMBOL(sk_stop_timer);
2934 
2935 void sock_init_data(struct socket *sock, struct sock *sk)
2936 {
2937 	sk_init_common(sk);
2938 	sk->sk_send_head	=	NULL;
2939 
2940 	timer_setup(&sk->sk_timer, NULL, 0);
2941 
2942 	sk->sk_allocation	=	GFP_KERNEL;
2943 	sk->sk_rcvbuf		=	sysctl_rmem_default;
2944 	sk->sk_sndbuf		=	sysctl_wmem_default;
2945 	sk->sk_state		=	TCP_CLOSE;
2946 	sk_set_socket(sk, sock);
2947 
2948 	sock_set_flag(sk, SOCK_ZAPPED);
2949 
2950 	if (sock) {
2951 		sk->sk_type	=	sock->type;
2952 		RCU_INIT_POINTER(sk->sk_wq, &sock->wq);
2953 		sock->sk	=	sk;
2954 		sk->sk_uid	=	SOCK_INODE(sock)->i_uid;
2955 	} else {
2956 		RCU_INIT_POINTER(sk->sk_wq, NULL);
2957 		sk->sk_uid	=	make_kuid(sock_net(sk)->user_ns, 0);
2958 	}
2959 
2960 	rwlock_init(&sk->sk_callback_lock);
2961 	if (sk->sk_kern_sock)
2962 		lockdep_set_class_and_name(
2963 			&sk->sk_callback_lock,
2964 			af_kern_callback_keys + sk->sk_family,
2965 			af_family_kern_clock_key_strings[sk->sk_family]);
2966 	else
2967 		lockdep_set_class_and_name(
2968 			&sk->sk_callback_lock,
2969 			af_callback_keys + sk->sk_family,
2970 			af_family_clock_key_strings[sk->sk_family]);
2971 
2972 	sk->sk_state_change	=	sock_def_wakeup;
2973 	sk->sk_data_ready	=	sock_def_readable;
2974 	sk->sk_write_space	=	sock_def_write_space;
2975 	sk->sk_error_report	=	sock_def_error_report;
2976 	sk->sk_destruct		=	sock_def_destruct;
2977 
2978 	sk->sk_frag.page	=	NULL;
2979 	sk->sk_frag.offset	=	0;
2980 	sk->sk_peek_off		=	-1;
2981 
2982 	sk->sk_peer_pid 	=	NULL;
2983 	sk->sk_peer_cred	=	NULL;
2984 	sk->sk_write_pending	=	0;
2985 	sk->sk_rcvlowat		=	1;
2986 	sk->sk_rcvtimeo		=	MAX_SCHEDULE_TIMEOUT;
2987 	sk->sk_sndtimeo		=	MAX_SCHEDULE_TIMEOUT;
2988 
2989 	sk->sk_stamp = SK_DEFAULT_STAMP;
2990 #if BITS_PER_LONG==32
2991 	seqlock_init(&sk->sk_stamp_seq);
2992 #endif
2993 	atomic_set(&sk->sk_zckey, 0);
2994 
2995 #ifdef CONFIG_NET_RX_BUSY_POLL
2996 	sk->sk_napi_id		=	0;
2997 	sk->sk_ll_usec		=	sysctl_net_busy_read;
2998 #endif
2999 
3000 	sk->sk_max_pacing_rate = ~0UL;
3001 	sk->sk_pacing_rate = ~0UL;
3002 	WRITE_ONCE(sk->sk_pacing_shift, 10);
3003 	sk->sk_incoming_cpu = -1;
3004 
3005 	sk_rx_queue_clear(sk);
3006 	/*
3007 	 * Before updating sk_refcnt, we must commit prior changes to memory
3008 	 * (Documentation/RCU/rculist_nulls.txt for details)
3009 	 */
3010 	smp_wmb();
3011 	refcount_set(&sk->sk_refcnt, 1);
3012 	atomic_set(&sk->sk_drops, 0);
3013 }
3014 EXPORT_SYMBOL(sock_init_data);
3015 
3016 void lock_sock_nested(struct sock *sk, int subclass)
3017 {
3018 	might_sleep();
3019 	spin_lock_bh(&sk->sk_lock.slock);
3020 	if (sk->sk_lock.owned)
3021 		__lock_sock(sk);
3022 	sk->sk_lock.owned = 1;
3023 	spin_unlock(&sk->sk_lock.slock);
3024 	/*
3025 	 * The sk_lock has mutex_lock() semantics here:
3026 	 */
3027 	mutex_acquire(&sk->sk_lock.dep_map, subclass, 0, _RET_IP_);
3028 	local_bh_enable();
3029 }
3030 EXPORT_SYMBOL(lock_sock_nested);
3031 
3032 void release_sock(struct sock *sk)
3033 {
3034 	spin_lock_bh(&sk->sk_lock.slock);
3035 	if (sk->sk_backlog.tail)
3036 		__release_sock(sk);
3037 
3038 	/* Warning : release_cb() might need to release sk ownership,
3039 	 * ie call sock_release_ownership(sk) before us.
3040 	 */
3041 	if (sk->sk_prot->release_cb)
3042 		sk->sk_prot->release_cb(sk);
3043 
3044 	sock_release_ownership(sk);
3045 	if (waitqueue_active(&sk->sk_lock.wq))
3046 		wake_up(&sk->sk_lock.wq);
3047 	spin_unlock_bh(&sk->sk_lock.slock);
3048 }
3049 EXPORT_SYMBOL(release_sock);
3050 
3051 /**
3052  * lock_sock_fast - fast version of lock_sock
3053  * @sk: socket
3054  *
3055  * This version should be used for very small section, where process wont block
3056  * return false if fast path is taken:
3057  *
3058  *   sk_lock.slock locked, owned = 0, BH disabled
3059  *
3060  * return true if slow path is taken:
3061  *
3062  *   sk_lock.slock unlocked, owned = 1, BH enabled
3063  */
3064 bool lock_sock_fast(struct sock *sk)
3065 {
3066 	might_sleep();
3067 	spin_lock_bh(&sk->sk_lock.slock);
3068 
3069 	if (!sk->sk_lock.owned)
3070 		/*
3071 		 * Note : We must disable BH
3072 		 */
3073 		return false;
3074 
3075 	__lock_sock(sk);
3076 	sk->sk_lock.owned = 1;
3077 	spin_unlock(&sk->sk_lock.slock);
3078 	/*
3079 	 * The sk_lock has mutex_lock() semantics here:
3080 	 */
3081 	mutex_acquire(&sk->sk_lock.dep_map, 0, 0, _RET_IP_);
3082 	local_bh_enable();
3083 	return true;
3084 }
3085 EXPORT_SYMBOL(lock_sock_fast);
3086 
3087 int sock_gettstamp(struct socket *sock, void __user *userstamp,
3088 		   bool timeval, bool time32)
3089 {
3090 	struct sock *sk = sock->sk;
3091 	struct timespec64 ts;
3092 
3093 	sock_enable_timestamp(sk, SOCK_TIMESTAMP);
3094 	ts = ktime_to_timespec64(sock_read_timestamp(sk));
3095 	if (ts.tv_sec == -1)
3096 		return -ENOENT;
3097 	if (ts.tv_sec == 0) {
3098 		ktime_t kt = ktime_get_real();
3099 		sock_write_timestamp(sk, kt);
3100 		ts = ktime_to_timespec64(kt);
3101 	}
3102 
3103 	if (timeval)
3104 		ts.tv_nsec /= 1000;
3105 
3106 #ifdef CONFIG_COMPAT_32BIT_TIME
3107 	if (time32)
3108 		return put_old_timespec32(&ts, userstamp);
3109 #endif
3110 #ifdef CONFIG_SPARC64
3111 	/* beware of padding in sparc64 timeval */
3112 	if (timeval && !in_compat_syscall()) {
3113 		struct __kernel_old_timeval __user tv = {
3114 			.tv_sec = ts.tv_sec,
3115 			.tv_usec = ts.tv_nsec,
3116 		};
3117 		if (copy_to_user(userstamp, &tv, sizeof(tv)))
3118 			return -EFAULT;
3119 		return 0;
3120 	}
3121 #endif
3122 	return put_timespec64(&ts, userstamp);
3123 }
3124 EXPORT_SYMBOL(sock_gettstamp);
3125 
3126 void sock_enable_timestamp(struct sock *sk, enum sock_flags flag)
3127 {
3128 	if (!sock_flag(sk, flag)) {
3129 		unsigned long previous_flags = sk->sk_flags;
3130 
3131 		sock_set_flag(sk, flag);
3132 		/*
3133 		 * we just set one of the two flags which require net
3134 		 * time stamping, but time stamping might have been on
3135 		 * already because of the other one
3136 		 */
3137 		if (sock_needs_netstamp(sk) &&
3138 		    !(previous_flags & SK_FLAGS_TIMESTAMP))
3139 			net_enable_timestamp();
3140 	}
3141 }
3142 
3143 int sock_recv_errqueue(struct sock *sk, struct msghdr *msg, int len,
3144 		       int level, int type)
3145 {
3146 	struct sock_exterr_skb *serr;
3147 	struct sk_buff *skb;
3148 	int copied, err;
3149 
3150 	err = -EAGAIN;
3151 	skb = sock_dequeue_err_skb(sk);
3152 	if (skb == NULL)
3153 		goto out;
3154 
3155 	copied = skb->len;
3156 	if (copied > len) {
3157 		msg->msg_flags |= MSG_TRUNC;
3158 		copied = len;
3159 	}
3160 	err = skb_copy_datagram_msg(skb, 0, msg, copied);
3161 	if (err)
3162 		goto out_free_skb;
3163 
3164 	sock_recv_timestamp(msg, sk, skb);
3165 
3166 	serr = SKB_EXT_ERR(skb);
3167 	put_cmsg(msg, level, type, sizeof(serr->ee), &serr->ee);
3168 
3169 	msg->msg_flags |= MSG_ERRQUEUE;
3170 	err = copied;
3171 
3172 out_free_skb:
3173 	kfree_skb(skb);
3174 out:
3175 	return err;
3176 }
3177 EXPORT_SYMBOL(sock_recv_errqueue);
3178 
3179 /*
3180  *	Get a socket option on an socket.
3181  *
3182  *	FIX: POSIX 1003.1g is very ambiguous here. It states that
3183  *	asynchronous errors should be reported by getsockopt. We assume
3184  *	this means if you specify SO_ERROR (otherwise whats the point of it).
3185  */
3186 int sock_common_getsockopt(struct socket *sock, int level, int optname,
3187 			   char __user *optval, int __user *optlen)
3188 {
3189 	struct sock *sk = sock->sk;
3190 
3191 	return sk->sk_prot->getsockopt(sk, level, optname, optval, optlen);
3192 }
3193 EXPORT_SYMBOL(sock_common_getsockopt);
3194 
3195 int sock_common_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
3196 			int flags)
3197 {
3198 	struct sock *sk = sock->sk;
3199 	int addr_len = 0;
3200 	int err;
3201 
3202 	err = sk->sk_prot->recvmsg(sk, msg, size, flags & MSG_DONTWAIT,
3203 				   flags & ~MSG_DONTWAIT, &addr_len);
3204 	if (err >= 0)
3205 		msg->msg_namelen = addr_len;
3206 	return err;
3207 }
3208 EXPORT_SYMBOL(sock_common_recvmsg);
3209 
3210 /*
3211  *	Set socket options on an inet socket.
3212  */
3213 int sock_common_setsockopt(struct socket *sock, int level, int optname,
3214 			   char __user *optval, unsigned int optlen)
3215 {
3216 	struct sock *sk = sock->sk;
3217 
3218 	return sk->sk_prot->setsockopt(sk, level, optname, optval, optlen);
3219 }
3220 EXPORT_SYMBOL(sock_common_setsockopt);
3221 
3222 void sk_common_release(struct sock *sk)
3223 {
3224 	if (sk->sk_prot->destroy)
3225 		sk->sk_prot->destroy(sk);
3226 
3227 	/*
3228 	 * Observation: when sock_common_release is called, processes have
3229 	 * no access to socket. But net still has.
3230 	 * Step one, detach it from networking:
3231 	 *
3232 	 * A. Remove from hash tables.
3233 	 */
3234 
3235 	sk->sk_prot->unhash(sk);
3236 
3237 	/*
3238 	 * In this point socket cannot receive new packets, but it is possible
3239 	 * that some packets are in flight because some CPU runs receiver and
3240 	 * did hash table lookup before we unhashed socket. They will achieve
3241 	 * receive queue and will be purged by socket destructor.
3242 	 *
3243 	 * Also we still have packets pending on receive queue and probably,
3244 	 * our own packets waiting in device queues. sock_destroy will drain
3245 	 * receive queue, but transmitted packets will delay socket destruction
3246 	 * until the last reference will be released.
3247 	 */
3248 
3249 	sock_orphan(sk);
3250 
3251 	xfrm_sk_free_policy(sk);
3252 
3253 	sk_refcnt_debug_release(sk);
3254 
3255 	sock_put(sk);
3256 }
3257 EXPORT_SYMBOL(sk_common_release);
3258 
3259 void sk_get_meminfo(const struct sock *sk, u32 *mem)
3260 {
3261 	memset(mem, 0, sizeof(*mem) * SK_MEMINFO_VARS);
3262 
3263 	mem[SK_MEMINFO_RMEM_ALLOC] = sk_rmem_alloc_get(sk);
3264 	mem[SK_MEMINFO_RCVBUF] = READ_ONCE(sk->sk_rcvbuf);
3265 	mem[SK_MEMINFO_WMEM_ALLOC] = sk_wmem_alloc_get(sk);
3266 	mem[SK_MEMINFO_SNDBUF] = READ_ONCE(sk->sk_sndbuf);
3267 	mem[SK_MEMINFO_FWD_ALLOC] = sk->sk_forward_alloc;
3268 	mem[SK_MEMINFO_WMEM_QUEUED] = READ_ONCE(sk->sk_wmem_queued);
3269 	mem[SK_MEMINFO_OPTMEM] = atomic_read(&sk->sk_omem_alloc);
3270 	mem[SK_MEMINFO_BACKLOG] = READ_ONCE(sk->sk_backlog.len);
3271 	mem[SK_MEMINFO_DROPS] = atomic_read(&sk->sk_drops);
3272 }
3273 
3274 #ifdef CONFIG_PROC_FS
3275 #define PROTO_INUSE_NR	64	/* should be enough for the first time */
3276 struct prot_inuse {
3277 	int val[PROTO_INUSE_NR];
3278 };
3279 
3280 static DECLARE_BITMAP(proto_inuse_idx, PROTO_INUSE_NR);
3281 
3282 void sock_prot_inuse_add(struct net *net, struct proto *prot, int val)
3283 {
3284 	__this_cpu_add(net->core.prot_inuse->val[prot->inuse_idx], val);
3285 }
3286 EXPORT_SYMBOL_GPL(sock_prot_inuse_add);
3287 
3288 int sock_prot_inuse_get(struct net *net, struct proto *prot)
3289 {
3290 	int cpu, idx = prot->inuse_idx;
3291 	int res = 0;
3292 
3293 	for_each_possible_cpu(cpu)
3294 		res += per_cpu_ptr(net->core.prot_inuse, cpu)->val[idx];
3295 
3296 	return res >= 0 ? res : 0;
3297 }
3298 EXPORT_SYMBOL_GPL(sock_prot_inuse_get);
3299 
3300 static void sock_inuse_add(struct net *net, int val)
3301 {
3302 	this_cpu_add(*net->core.sock_inuse, val);
3303 }
3304 
3305 int sock_inuse_get(struct net *net)
3306 {
3307 	int cpu, res = 0;
3308 
3309 	for_each_possible_cpu(cpu)
3310 		res += *per_cpu_ptr(net->core.sock_inuse, cpu);
3311 
3312 	return res;
3313 }
3314 
3315 EXPORT_SYMBOL_GPL(sock_inuse_get);
3316 
3317 static int __net_init sock_inuse_init_net(struct net *net)
3318 {
3319 	net->core.prot_inuse = alloc_percpu(struct prot_inuse);
3320 	if (net->core.prot_inuse == NULL)
3321 		return -ENOMEM;
3322 
3323 	net->core.sock_inuse = alloc_percpu(int);
3324 	if (net->core.sock_inuse == NULL)
3325 		goto out;
3326 
3327 	return 0;
3328 
3329 out:
3330 	free_percpu(net->core.prot_inuse);
3331 	return -ENOMEM;
3332 }
3333 
3334 static void __net_exit sock_inuse_exit_net(struct net *net)
3335 {
3336 	free_percpu(net->core.prot_inuse);
3337 	free_percpu(net->core.sock_inuse);
3338 }
3339 
3340 static struct pernet_operations net_inuse_ops = {
3341 	.init = sock_inuse_init_net,
3342 	.exit = sock_inuse_exit_net,
3343 };
3344 
3345 static __init int net_inuse_init(void)
3346 {
3347 	if (register_pernet_subsys(&net_inuse_ops))
3348 		panic("Cannot initialize net inuse counters");
3349 
3350 	return 0;
3351 }
3352 
3353 core_initcall(net_inuse_init);
3354 
3355 static int assign_proto_idx(struct proto *prot)
3356 {
3357 	prot->inuse_idx = find_first_zero_bit(proto_inuse_idx, PROTO_INUSE_NR);
3358 
3359 	if (unlikely(prot->inuse_idx == PROTO_INUSE_NR - 1)) {
3360 		pr_err("PROTO_INUSE_NR exhausted\n");
3361 		return -ENOSPC;
3362 	}
3363 
3364 	set_bit(prot->inuse_idx, proto_inuse_idx);
3365 	return 0;
3366 }
3367 
3368 static void release_proto_idx(struct proto *prot)
3369 {
3370 	if (prot->inuse_idx != PROTO_INUSE_NR - 1)
3371 		clear_bit(prot->inuse_idx, proto_inuse_idx);
3372 }
3373 #else
3374 static inline int assign_proto_idx(struct proto *prot)
3375 {
3376 	return 0;
3377 }
3378 
3379 static inline void release_proto_idx(struct proto *prot)
3380 {
3381 }
3382 
3383 static void sock_inuse_add(struct net *net, int val)
3384 {
3385 }
3386 #endif
3387 
3388 static void req_prot_cleanup(struct request_sock_ops *rsk_prot)
3389 {
3390 	if (!rsk_prot)
3391 		return;
3392 	kfree(rsk_prot->slab_name);
3393 	rsk_prot->slab_name = NULL;
3394 	kmem_cache_destroy(rsk_prot->slab);
3395 	rsk_prot->slab = NULL;
3396 }
3397 
3398 static int req_prot_init(const struct proto *prot)
3399 {
3400 	struct request_sock_ops *rsk_prot = prot->rsk_prot;
3401 
3402 	if (!rsk_prot)
3403 		return 0;
3404 
3405 	rsk_prot->slab_name = kasprintf(GFP_KERNEL, "request_sock_%s",
3406 					prot->name);
3407 	if (!rsk_prot->slab_name)
3408 		return -ENOMEM;
3409 
3410 	rsk_prot->slab = kmem_cache_create(rsk_prot->slab_name,
3411 					   rsk_prot->obj_size, 0,
3412 					   SLAB_ACCOUNT | prot->slab_flags,
3413 					   NULL);
3414 
3415 	if (!rsk_prot->slab) {
3416 		pr_crit("%s: Can't create request sock SLAB cache!\n",
3417 			prot->name);
3418 		return -ENOMEM;
3419 	}
3420 	return 0;
3421 }
3422 
3423 int proto_register(struct proto *prot, int alloc_slab)
3424 {
3425 	int ret = -ENOBUFS;
3426 
3427 	if (alloc_slab) {
3428 		prot->slab = kmem_cache_create_usercopy(prot->name,
3429 					prot->obj_size, 0,
3430 					SLAB_HWCACHE_ALIGN | SLAB_ACCOUNT |
3431 					prot->slab_flags,
3432 					prot->useroffset, prot->usersize,
3433 					NULL);
3434 
3435 		if (prot->slab == NULL) {
3436 			pr_crit("%s: Can't create sock SLAB cache!\n",
3437 				prot->name);
3438 			goto out;
3439 		}
3440 
3441 		if (req_prot_init(prot))
3442 			goto out_free_request_sock_slab;
3443 
3444 		if (prot->twsk_prot != NULL) {
3445 			prot->twsk_prot->twsk_slab_name = kasprintf(GFP_KERNEL, "tw_sock_%s", prot->name);
3446 
3447 			if (prot->twsk_prot->twsk_slab_name == NULL)
3448 				goto out_free_request_sock_slab;
3449 
3450 			prot->twsk_prot->twsk_slab =
3451 				kmem_cache_create(prot->twsk_prot->twsk_slab_name,
3452 						  prot->twsk_prot->twsk_obj_size,
3453 						  0,
3454 						  SLAB_ACCOUNT |
3455 						  prot->slab_flags,
3456 						  NULL);
3457 			if (prot->twsk_prot->twsk_slab == NULL)
3458 				goto out_free_timewait_sock_slab_name;
3459 		}
3460 	}
3461 
3462 	mutex_lock(&proto_list_mutex);
3463 	ret = assign_proto_idx(prot);
3464 	if (ret) {
3465 		mutex_unlock(&proto_list_mutex);
3466 		goto out_free_timewait_sock_slab_name;
3467 	}
3468 	list_add(&prot->node, &proto_list);
3469 	mutex_unlock(&proto_list_mutex);
3470 	return ret;
3471 
3472 out_free_timewait_sock_slab_name:
3473 	if (alloc_slab && prot->twsk_prot)
3474 		kfree(prot->twsk_prot->twsk_slab_name);
3475 out_free_request_sock_slab:
3476 	if (alloc_slab) {
3477 		req_prot_cleanup(prot->rsk_prot);
3478 
3479 		kmem_cache_destroy(prot->slab);
3480 		prot->slab = NULL;
3481 	}
3482 out:
3483 	return ret;
3484 }
3485 EXPORT_SYMBOL(proto_register);
3486 
3487 void proto_unregister(struct proto *prot)
3488 {
3489 	mutex_lock(&proto_list_mutex);
3490 	release_proto_idx(prot);
3491 	list_del(&prot->node);
3492 	mutex_unlock(&proto_list_mutex);
3493 
3494 	kmem_cache_destroy(prot->slab);
3495 	prot->slab = NULL;
3496 
3497 	req_prot_cleanup(prot->rsk_prot);
3498 
3499 	if (prot->twsk_prot != NULL && prot->twsk_prot->twsk_slab != NULL) {
3500 		kmem_cache_destroy(prot->twsk_prot->twsk_slab);
3501 		kfree(prot->twsk_prot->twsk_slab_name);
3502 		prot->twsk_prot->twsk_slab = NULL;
3503 	}
3504 }
3505 EXPORT_SYMBOL(proto_unregister);
3506 
3507 int sock_load_diag_module(int family, int protocol)
3508 {
3509 	if (!protocol) {
3510 		if (!sock_is_registered(family))
3511 			return -ENOENT;
3512 
3513 		return request_module("net-pf-%d-proto-%d-type-%d", PF_NETLINK,
3514 				      NETLINK_SOCK_DIAG, family);
3515 	}
3516 
3517 #ifdef CONFIG_INET
3518 	if (family == AF_INET &&
3519 	    protocol != IPPROTO_RAW &&
3520 	    protocol < MAX_INET_PROTOS &&
3521 	    !rcu_access_pointer(inet_protos[protocol]))
3522 		return -ENOENT;
3523 #endif
3524 
3525 	return request_module("net-pf-%d-proto-%d-type-%d-%d", PF_NETLINK,
3526 			      NETLINK_SOCK_DIAG, family, protocol);
3527 }
3528 EXPORT_SYMBOL(sock_load_diag_module);
3529 
3530 #ifdef CONFIG_PROC_FS
3531 static void *proto_seq_start(struct seq_file *seq, loff_t *pos)
3532 	__acquires(proto_list_mutex)
3533 {
3534 	mutex_lock(&proto_list_mutex);
3535 	return seq_list_start_head(&proto_list, *pos);
3536 }
3537 
3538 static void *proto_seq_next(struct seq_file *seq, void *v, loff_t *pos)
3539 {
3540 	return seq_list_next(v, &proto_list, pos);
3541 }
3542 
3543 static void proto_seq_stop(struct seq_file *seq, void *v)
3544 	__releases(proto_list_mutex)
3545 {
3546 	mutex_unlock(&proto_list_mutex);
3547 }
3548 
3549 static char proto_method_implemented(const void *method)
3550 {
3551 	return method == NULL ? 'n' : 'y';
3552 }
3553 static long sock_prot_memory_allocated(struct proto *proto)
3554 {
3555 	return proto->memory_allocated != NULL ? proto_memory_allocated(proto) : -1L;
3556 }
3557 
3558 static const char *sock_prot_memory_pressure(struct proto *proto)
3559 {
3560 	return proto->memory_pressure != NULL ?
3561 	proto_memory_pressure(proto) ? "yes" : "no" : "NI";
3562 }
3563 
3564 static void proto_seq_printf(struct seq_file *seq, struct proto *proto)
3565 {
3566 
3567 	seq_printf(seq, "%-9s %4u %6d  %6ld   %-3s %6u   %-3s  %-10s "
3568 			"%2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c\n",
3569 		   proto->name,
3570 		   proto->obj_size,
3571 		   sock_prot_inuse_get(seq_file_net(seq), proto),
3572 		   sock_prot_memory_allocated(proto),
3573 		   sock_prot_memory_pressure(proto),
3574 		   proto->max_header,
3575 		   proto->slab == NULL ? "no" : "yes",
3576 		   module_name(proto->owner),
3577 		   proto_method_implemented(proto->close),
3578 		   proto_method_implemented(proto->connect),
3579 		   proto_method_implemented(proto->disconnect),
3580 		   proto_method_implemented(proto->accept),
3581 		   proto_method_implemented(proto->ioctl),
3582 		   proto_method_implemented(proto->init),
3583 		   proto_method_implemented(proto->destroy),
3584 		   proto_method_implemented(proto->shutdown),
3585 		   proto_method_implemented(proto->setsockopt),
3586 		   proto_method_implemented(proto->getsockopt),
3587 		   proto_method_implemented(proto->sendmsg),
3588 		   proto_method_implemented(proto->recvmsg),
3589 		   proto_method_implemented(proto->sendpage),
3590 		   proto_method_implemented(proto->bind),
3591 		   proto_method_implemented(proto->backlog_rcv),
3592 		   proto_method_implemented(proto->hash),
3593 		   proto_method_implemented(proto->unhash),
3594 		   proto_method_implemented(proto->get_port),
3595 		   proto_method_implemented(proto->enter_memory_pressure));
3596 }
3597 
3598 static int proto_seq_show(struct seq_file *seq, void *v)
3599 {
3600 	if (v == &proto_list)
3601 		seq_printf(seq, "%-9s %-4s %-8s %-6s %-5s %-7s %-4s %-10s %s",
3602 			   "protocol",
3603 			   "size",
3604 			   "sockets",
3605 			   "memory",
3606 			   "press",
3607 			   "maxhdr",
3608 			   "slab",
3609 			   "module",
3610 			   "cl co di ac io in de sh ss gs se re sp bi br ha uh gp em\n");
3611 	else
3612 		proto_seq_printf(seq, list_entry(v, struct proto, node));
3613 	return 0;
3614 }
3615 
3616 static const struct seq_operations proto_seq_ops = {
3617 	.start  = proto_seq_start,
3618 	.next   = proto_seq_next,
3619 	.stop   = proto_seq_stop,
3620 	.show   = proto_seq_show,
3621 };
3622 
3623 static __net_init int proto_init_net(struct net *net)
3624 {
3625 	if (!proc_create_net("protocols", 0444, net->proc_net, &proto_seq_ops,
3626 			sizeof(struct seq_net_private)))
3627 		return -ENOMEM;
3628 
3629 	return 0;
3630 }
3631 
3632 static __net_exit void proto_exit_net(struct net *net)
3633 {
3634 	remove_proc_entry("protocols", net->proc_net);
3635 }
3636 
3637 
3638 static __net_initdata struct pernet_operations proto_net_ops = {
3639 	.init = proto_init_net,
3640 	.exit = proto_exit_net,
3641 };
3642 
3643 static int __init proto_init(void)
3644 {
3645 	return register_pernet_subsys(&proto_net_ops);
3646 }
3647 
3648 subsys_initcall(proto_init);
3649 
3650 #endif /* PROC_FS */
3651 
3652 #ifdef CONFIG_NET_RX_BUSY_POLL
3653 bool sk_busy_loop_end(void *p, unsigned long start_time)
3654 {
3655 	struct sock *sk = p;
3656 
3657 	return !skb_queue_empty_lockless(&sk->sk_receive_queue) ||
3658 	       sk_busy_loop_timeout(sk, start_time);
3659 }
3660 EXPORT_SYMBOL(sk_busy_loop_end);
3661 #endif /* CONFIG_NET_RX_BUSY_POLL */
3662 
3663 int sock_bind_add(struct sock *sk, struct sockaddr *addr, int addr_len)
3664 {
3665 	if (!sk->sk_prot->bind_add)
3666 		return -EOPNOTSUPP;
3667 	return sk->sk_prot->bind_add(sk, addr, addr_len);
3668 }
3669 EXPORT_SYMBOL(sock_bind_add);
3670