xref: /linux/net/core/sock.c (revision 962fad301c33dec69324dc2d9320fd84a119a24c)
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 void sock_set_mark(struct sock *sk, u32 val)
824 {
825 	lock_sock(sk);
826 	sk->sk_mark = val;
827 	release_sock(sk);
828 }
829 EXPORT_SYMBOL(sock_set_mark);
830 
831 /*
832  *	This is meant for all protocols to use and covers goings on
833  *	at the socket level. Everything here is generic.
834  */
835 
836 int sock_setsockopt(struct socket *sock, int level, int optname,
837 		    sockptr_t optval, unsigned int optlen)
838 {
839 	struct sock_txtime sk_txtime;
840 	struct sock *sk = sock->sk;
841 	int val;
842 	int valbool;
843 	struct linger ling;
844 	int ret = 0;
845 
846 	/*
847 	 *	Options without arguments
848 	 */
849 
850 	if (optname == SO_BINDTODEVICE)
851 		return sock_setbindtodevice(sk, optval, optlen);
852 
853 	if (optlen < sizeof(int))
854 		return -EINVAL;
855 
856 	if (copy_from_sockptr(&val, optval, sizeof(val)))
857 		return -EFAULT;
858 
859 	valbool = val ? 1 : 0;
860 
861 	lock_sock(sk);
862 
863 	switch (optname) {
864 	case SO_DEBUG:
865 		if (val && !capable(CAP_NET_ADMIN))
866 			ret = -EACCES;
867 		else
868 			sock_valbool_flag(sk, SOCK_DBG, valbool);
869 		break;
870 	case SO_REUSEADDR:
871 		sk->sk_reuse = (valbool ? SK_CAN_REUSE : SK_NO_REUSE);
872 		break;
873 	case SO_REUSEPORT:
874 		sk->sk_reuseport = valbool;
875 		break;
876 	case SO_TYPE:
877 	case SO_PROTOCOL:
878 	case SO_DOMAIN:
879 	case SO_ERROR:
880 		ret = -ENOPROTOOPT;
881 		break;
882 	case SO_DONTROUTE:
883 		sock_valbool_flag(sk, SOCK_LOCALROUTE, valbool);
884 		sk_dst_reset(sk);
885 		break;
886 	case SO_BROADCAST:
887 		sock_valbool_flag(sk, SOCK_BROADCAST, valbool);
888 		break;
889 	case SO_SNDBUF:
890 		/* Don't error on this BSD doesn't and if you think
891 		 * about it this is right. Otherwise apps have to
892 		 * play 'guess the biggest size' games. RCVBUF/SNDBUF
893 		 * are treated in BSD as hints
894 		 */
895 		val = min_t(u32, val, sysctl_wmem_max);
896 set_sndbuf:
897 		/* Ensure val * 2 fits into an int, to prevent max_t()
898 		 * from treating it as a negative value.
899 		 */
900 		val = min_t(int, val, INT_MAX / 2);
901 		sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
902 		WRITE_ONCE(sk->sk_sndbuf,
903 			   max_t(int, val * 2, SOCK_MIN_SNDBUF));
904 		/* Wake up sending tasks if we upped the value. */
905 		sk->sk_write_space(sk);
906 		break;
907 
908 	case SO_SNDBUFFORCE:
909 		if (!capable(CAP_NET_ADMIN)) {
910 			ret = -EPERM;
911 			break;
912 		}
913 
914 		/* No negative values (to prevent underflow, as val will be
915 		 * multiplied by 2).
916 		 */
917 		if (val < 0)
918 			val = 0;
919 		goto set_sndbuf;
920 
921 	case SO_RCVBUF:
922 		/* Don't error on this BSD doesn't and if you think
923 		 * about it this is right. Otherwise apps have to
924 		 * play 'guess the biggest size' games. RCVBUF/SNDBUF
925 		 * are treated in BSD as hints
926 		 */
927 		__sock_set_rcvbuf(sk, min_t(u32, val, sysctl_rmem_max));
928 		break;
929 
930 	case SO_RCVBUFFORCE:
931 		if (!capable(CAP_NET_ADMIN)) {
932 			ret = -EPERM;
933 			break;
934 		}
935 
936 		/* No negative values (to prevent underflow, as val will be
937 		 * multiplied by 2).
938 		 */
939 		__sock_set_rcvbuf(sk, max(val, 0));
940 		break;
941 
942 	case SO_KEEPALIVE:
943 		if (sk->sk_prot->keepalive)
944 			sk->sk_prot->keepalive(sk, valbool);
945 		sock_valbool_flag(sk, SOCK_KEEPOPEN, valbool);
946 		break;
947 
948 	case SO_OOBINLINE:
949 		sock_valbool_flag(sk, SOCK_URGINLINE, valbool);
950 		break;
951 
952 	case SO_NO_CHECK:
953 		sk->sk_no_check_tx = valbool;
954 		break;
955 
956 	case SO_PRIORITY:
957 		if ((val >= 0 && val <= 6) ||
958 		    ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
959 			sk->sk_priority = val;
960 		else
961 			ret = -EPERM;
962 		break;
963 
964 	case SO_LINGER:
965 		if (optlen < sizeof(ling)) {
966 			ret = -EINVAL;	/* 1003.1g */
967 			break;
968 		}
969 		if (copy_from_sockptr(&ling, optval, sizeof(ling))) {
970 			ret = -EFAULT;
971 			break;
972 		}
973 		if (!ling.l_onoff)
974 			sock_reset_flag(sk, SOCK_LINGER);
975 		else {
976 #if (BITS_PER_LONG == 32)
977 			if ((unsigned int)ling.l_linger >= MAX_SCHEDULE_TIMEOUT/HZ)
978 				sk->sk_lingertime = MAX_SCHEDULE_TIMEOUT;
979 			else
980 #endif
981 				sk->sk_lingertime = (unsigned int)ling.l_linger * HZ;
982 			sock_set_flag(sk, SOCK_LINGER);
983 		}
984 		break;
985 
986 	case SO_BSDCOMPAT:
987 		sock_warn_obsolete_bsdism("setsockopt");
988 		break;
989 
990 	case SO_PASSCRED:
991 		if (valbool)
992 			set_bit(SOCK_PASSCRED, &sock->flags);
993 		else
994 			clear_bit(SOCK_PASSCRED, &sock->flags);
995 		break;
996 
997 	case SO_TIMESTAMP_OLD:
998 		__sock_set_timestamps(sk, valbool, false, false);
999 		break;
1000 	case SO_TIMESTAMP_NEW:
1001 		__sock_set_timestamps(sk, valbool, true, false);
1002 		break;
1003 	case SO_TIMESTAMPNS_OLD:
1004 		__sock_set_timestamps(sk, valbool, false, true);
1005 		break;
1006 	case SO_TIMESTAMPNS_NEW:
1007 		__sock_set_timestamps(sk, valbool, true, true);
1008 		break;
1009 	case SO_TIMESTAMPING_NEW:
1010 		sock_set_flag(sk, SOCK_TSTAMP_NEW);
1011 		/* fall through */
1012 	case SO_TIMESTAMPING_OLD:
1013 		if (val & ~SOF_TIMESTAMPING_MASK) {
1014 			ret = -EINVAL;
1015 			break;
1016 		}
1017 
1018 		if (val & SOF_TIMESTAMPING_OPT_ID &&
1019 		    !(sk->sk_tsflags & SOF_TIMESTAMPING_OPT_ID)) {
1020 			if (sk->sk_protocol == IPPROTO_TCP &&
1021 			    sk->sk_type == SOCK_STREAM) {
1022 				if ((1 << sk->sk_state) &
1023 				    (TCPF_CLOSE | TCPF_LISTEN)) {
1024 					ret = -EINVAL;
1025 					break;
1026 				}
1027 				sk->sk_tskey = tcp_sk(sk)->snd_una;
1028 			} else {
1029 				sk->sk_tskey = 0;
1030 			}
1031 		}
1032 
1033 		if (val & SOF_TIMESTAMPING_OPT_STATS &&
1034 		    !(val & SOF_TIMESTAMPING_OPT_TSONLY)) {
1035 			ret = -EINVAL;
1036 			break;
1037 		}
1038 
1039 		sk->sk_tsflags = val;
1040 		if (val & SOF_TIMESTAMPING_RX_SOFTWARE)
1041 			sock_enable_timestamp(sk,
1042 					      SOCK_TIMESTAMPING_RX_SOFTWARE);
1043 		else {
1044 			if (optname == SO_TIMESTAMPING_NEW)
1045 				sock_reset_flag(sk, SOCK_TSTAMP_NEW);
1046 
1047 			sock_disable_timestamp(sk,
1048 					       (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE));
1049 		}
1050 		break;
1051 
1052 	case SO_RCVLOWAT:
1053 		if (val < 0)
1054 			val = INT_MAX;
1055 		if (sock->ops->set_rcvlowat)
1056 			ret = sock->ops->set_rcvlowat(sk, val);
1057 		else
1058 			WRITE_ONCE(sk->sk_rcvlowat, val ? : 1);
1059 		break;
1060 
1061 	case SO_RCVTIMEO_OLD:
1062 	case SO_RCVTIMEO_NEW:
1063 		ret = sock_set_timeout(&sk->sk_rcvtimeo, optval,
1064 				       optlen, optname == SO_RCVTIMEO_OLD);
1065 		break;
1066 
1067 	case SO_SNDTIMEO_OLD:
1068 	case SO_SNDTIMEO_NEW:
1069 		ret = sock_set_timeout(&sk->sk_sndtimeo, optval,
1070 				       optlen, optname == SO_SNDTIMEO_OLD);
1071 		break;
1072 
1073 	case SO_ATTACH_FILTER: {
1074 		struct sock_fprog fprog;
1075 
1076 		ret = copy_bpf_fprog_from_user(&fprog, optval, optlen);
1077 		if (!ret)
1078 			ret = sk_attach_filter(&fprog, sk);
1079 		break;
1080 	}
1081 	case SO_ATTACH_BPF:
1082 		ret = -EINVAL;
1083 		if (optlen == sizeof(u32)) {
1084 			u32 ufd;
1085 
1086 			ret = -EFAULT;
1087 			if (copy_from_sockptr(&ufd, optval, sizeof(ufd)))
1088 				break;
1089 
1090 			ret = sk_attach_bpf(ufd, sk);
1091 		}
1092 		break;
1093 
1094 	case SO_ATTACH_REUSEPORT_CBPF: {
1095 		struct sock_fprog fprog;
1096 
1097 		ret = copy_bpf_fprog_from_user(&fprog, optval, optlen);
1098 		if (!ret)
1099 			ret = sk_reuseport_attach_filter(&fprog, sk);
1100 		break;
1101 	}
1102 	case SO_ATTACH_REUSEPORT_EBPF:
1103 		ret = -EINVAL;
1104 		if (optlen == sizeof(u32)) {
1105 			u32 ufd;
1106 
1107 			ret = -EFAULT;
1108 			if (copy_from_sockptr(&ufd, optval, sizeof(ufd)))
1109 				break;
1110 
1111 			ret = sk_reuseport_attach_bpf(ufd, sk);
1112 		}
1113 		break;
1114 
1115 	case SO_DETACH_REUSEPORT_BPF:
1116 		ret = reuseport_detach_prog(sk);
1117 		break;
1118 
1119 	case SO_DETACH_FILTER:
1120 		ret = sk_detach_filter(sk);
1121 		break;
1122 
1123 	case SO_LOCK_FILTER:
1124 		if (sock_flag(sk, SOCK_FILTER_LOCKED) && !valbool)
1125 			ret = -EPERM;
1126 		else
1127 			sock_valbool_flag(sk, SOCK_FILTER_LOCKED, valbool);
1128 		break;
1129 
1130 	case SO_PASSSEC:
1131 		if (valbool)
1132 			set_bit(SOCK_PASSSEC, &sock->flags);
1133 		else
1134 			clear_bit(SOCK_PASSSEC, &sock->flags);
1135 		break;
1136 	case SO_MARK:
1137 		if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) {
1138 			ret = -EPERM;
1139 		} else if (val != sk->sk_mark) {
1140 			sk->sk_mark = val;
1141 			sk_dst_reset(sk);
1142 		}
1143 		break;
1144 
1145 	case SO_RXQ_OVFL:
1146 		sock_valbool_flag(sk, SOCK_RXQ_OVFL, valbool);
1147 		break;
1148 
1149 	case SO_WIFI_STATUS:
1150 		sock_valbool_flag(sk, SOCK_WIFI_STATUS, valbool);
1151 		break;
1152 
1153 	case SO_PEEK_OFF:
1154 		if (sock->ops->set_peek_off)
1155 			ret = sock->ops->set_peek_off(sk, val);
1156 		else
1157 			ret = -EOPNOTSUPP;
1158 		break;
1159 
1160 	case SO_NOFCS:
1161 		sock_valbool_flag(sk, SOCK_NOFCS, valbool);
1162 		break;
1163 
1164 	case SO_SELECT_ERR_QUEUE:
1165 		sock_valbool_flag(sk, SOCK_SELECT_ERR_QUEUE, valbool);
1166 		break;
1167 
1168 #ifdef CONFIG_NET_RX_BUSY_POLL
1169 	case SO_BUSY_POLL:
1170 		/* allow unprivileged users to decrease the value */
1171 		if ((val > sk->sk_ll_usec) && !capable(CAP_NET_ADMIN))
1172 			ret = -EPERM;
1173 		else {
1174 			if (val < 0)
1175 				ret = -EINVAL;
1176 			else
1177 				sk->sk_ll_usec = val;
1178 		}
1179 		break;
1180 #endif
1181 
1182 	case SO_MAX_PACING_RATE:
1183 		{
1184 		unsigned long ulval = (val == ~0U) ? ~0UL : val;
1185 
1186 		if (sizeof(ulval) != sizeof(val) &&
1187 		    optlen >= sizeof(ulval) &&
1188 		    copy_from_sockptr(&ulval, optval, sizeof(ulval))) {
1189 			ret = -EFAULT;
1190 			break;
1191 		}
1192 		if (ulval != ~0UL)
1193 			cmpxchg(&sk->sk_pacing_status,
1194 				SK_PACING_NONE,
1195 				SK_PACING_NEEDED);
1196 		sk->sk_max_pacing_rate = ulval;
1197 		sk->sk_pacing_rate = min(sk->sk_pacing_rate, ulval);
1198 		break;
1199 		}
1200 	case SO_INCOMING_CPU:
1201 		WRITE_ONCE(sk->sk_incoming_cpu, val);
1202 		break;
1203 
1204 	case SO_CNX_ADVICE:
1205 		if (val == 1)
1206 			dst_negative_advice(sk);
1207 		break;
1208 
1209 	case SO_ZEROCOPY:
1210 		if (sk->sk_family == PF_INET || sk->sk_family == PF_INET6) {
1211 			if (!((sk->sk_type == SOCK_STREAM &&
1212 			       sk->sk_protocol == IPPROTO_TCP) ||
1213 			      (sk->sk_type == SOCK_DGRAM &&
1214 			       sk->sk_protocol == IPPROTO_UDP)))
1215 				ret = -ENOTSUPP;
1216 		} else if (sk->sk_family != PF_RDS) {
1217 			ret = -ENOTSUPP;
1218 		}
1219 		if (!ret) {
1220 			if (val < 0 || val > 1)
1221 				ret = -EINVAL;
1222 			else
1223 				sock_valbool_flag(sk, SOCK_ZEROCOPY, valbool);
1224 		}
1225 		break;
1226 
1227 	case SO_TXTIME:
1228 		if (optlen != sizeof(struct sock_txtime)) {
1229 			ret = -EINVAL;
1230 			break;
1231 		} else if (copy_from_sockptr(&sk_txtime, optval,
1232 			   sizeof(struct sock_txtime))) {
1233 			ret = -EFAULT;
1234 			break;
1235 		} else if (sk_txtime.flags & ~SOF_TXTIME_FLAGS_MASK) {
1236 			ret = -EINVAL;
1237 			break;
1238 		}
1239 		/* CLOCK_MONOTONIC is only used by sch_fq, and this packet
1240 		 * scheduler has enough safe guards.
1241 		 */
1242 		if (sk_txtime.clockid != CLOCK_MONOTONIC &&
1243 		    !ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) {
1244 			ret = -EPERM;
1245 			break;
1246 		}
1247 		sock_valbool_flag(sk, SOCK_TXTIME, true);
1248 		sk->sk_clockid = sk_txtime.clockid;
1249 		sk->sk_txtime_deadline_mode =
1250 			!!(sk_txtime.flags & SOF_TXTIME_DEADLINE_MODE);
1251 		sk->sk_txtime_report_errors =
1252 			!!(sk_txtime.flags & SOF_TXTIME_REPORT_ERRORS);
1253 		break;
1254 
1255 	case SO_BINDTOIFINDEX:
1256 		ret = sock_bindtoindex_locked(sk, val);
1257 		break;
1258 
1259 	default:
1260 		ret = -ENOPROTOOPT;
1261 		break;
1262 	}
1263 	release_sock(sk);
1264 	return ret;
1265 }
1266 EXPORT_SYMBOL(sock_setsockopt);
1267 
1268 
1269 static void cred_to_ucred(struct pid *pid, const struct cred *cred,
1270 			  struct ucred *ucred)
1271 {
1272 	ucred->pid = pid_vnr(pid);
1273 	ucred->uid = ucred->gid = -1;
1274 	if (cred) {
1275 		struct user_namespace *current_ns = current_user_ns();
1276 
1277 		ucred->uid = from_kuid_munged(current_ns, cred->euid);
1278 		ucred->gid = from_kgid_munged(current_ns, cred->egid);
1279 	}
1280 }
1281 
1282 static int groups_to_user(gid_t __user *dst, const struct group_info *src)
1283 {
1284 	struct user_namespace *user_ns = current_user_ns();
1285 	int i;
1286 
1287 	for (i = 0; i < src->ngroups; i++)
1288 		if (put_user(from_kgid_munged(user_ns, src->gid[i]), dst + i))
1289 			return -EFAULT;
1290 
1291 	return 0;
1292 }
1293 
1294 int sock_getsockopt(struct socket *sock, int level, int optname,
1295 		    char __user *optval, int __user *optlen)
1296 {
1297 	struct sock *sk = sock->sk;
1298 
1299 	union {
1300 		int val;
1301 		u64 val64;
1302 		unsigned long ulval;
1303 		struct linger ling;
1304 		struct old_timeval32 tm32;
1305 		struct __kernel_old_timeval tm;
1306 		struct  __kernel_sock_timeval stm;
1307 		struct sock_txtime txtime;
1308 	} v;
1309 
1310 	int lv = sizeof(int);
1311 	int len;
1312 
1313 	if (get_user(len, optlen))
1314 		return -EFAULT;
1315 	if (len < 0)
1316 		return -EINVAL;
1317 
1318 	memset(&v, 0, sizeof(v));
1319 
1320 	switch (optname) {
1321 	case SO_DEBUG:
1322 		v.val = sock_flag(sk, SOCK_DBG);
1323 		break;
1324 
1325 	case SO_DONTROUTE:
1326 		v.val = sock_flag(sk, SOCK_LOCALROUTE);
1327 		break;
1328 
1329 	case SO_BROADCAST:
1330 		v.val = sock_flag(sk, SOCK_BROADCAST);
1331 		break;
1332 
1333 	case SO_SNDBUF:
1334 		v.val = sk->sk_sndbuf;
1335 		break;
1336 
1337 	case SO_RCVBUF:
1338 		v.val = sk->sk_rcvbuf;
1339 		break;
1340 
1341 	case SO_REUSEADDR:
1342 		v.val = sk->sk_reuse;
1343 		break;
1344 
1345 	case SO_REUSEPORT:
1346 		v.val = sk->sk_reuseport;
1347 		break;
1348 
1349 	case SO_KEEPALIVE:
1350 		v.val = sock_flag(sk, SOCK_KEEPOPEN);
1351 		break;
1352 
1353 	case SO_TYPE:
1354 		v.val = sk->sk_type;
1355 		break;
1356 
1357 	case SO_PROTOCOL:
1358 		v.val = sk->sk_protocol;
1359 		break;
1360 
1361 	case SO_DOMAIN:
1362 		v.val = sk->sk_family;
1363 		break;
1364 
1365 	case SO_ERROR:
1366 		v.val = -sock_error(sk);
1367 		if (v.val == 0)
1368 			v.val = xchg(&sk->sk_err_soft, 0);
1369 		break;
1370 
1371 	case SO_OOBINLINE:
1372 		v.val = sock_flag(sk, SOCK_URGINLINE);
1373 		break;
1374 
1375 	case SO_NO_CHECK:
1376 		v.val = sk->sk_no_check_tx;
1377 		break;
1378 
1379 	case SO_PRIORITY:
1380 		v.val = sk->sk_priority;
1381 		break;
1382 
1383 	case SO_LINGER:
1384 		lv		= sizeof(v.ling);
1385 		v.ling.l_onoff	= sock_flag(sk, SOCK_LINGER);
1386 		v.ling.l_linger	= sk->sk_lingertime / HZ;
1387 		break;
1388 
1389 	case SO_BSDCOMPAT:
1390 		sock_warn_obsolete_bsdism("getsockopt");
1391 		break;
1392 
1393 	case SO_TIMESTAMP_OLD:
1394 		v.val = sock_flag(sk, SOCK_RCVTSTAMP) &&
1395 				!sock_flag(sk, SOCK_TSTAMP_NEW) &&
1396 				!sock_flag(sk, SOCK_RCVTSTAMPNS);
1397 		break;
1398 
1399 	case SO_TIMESTAMPNS_OLD:
1400 		v.val = sock_flag(sk, SOCK_RCVTSTAMPNS) && !sock_flag(sk, SOCK_TSTAMP_NEW);
1401 		break;
1402 
1403 	case SO_TIMESTAMP_NEW:
1404 		v.val = sock_flag(sk, SOCK_RCVTSTAMP) && sock_flag(sk, SOCK_TSTAMP_NEW);
1405 		break;
1406 
1407 	case SO_TIMESTAMPNS_NEW:
1408 		v.val = sock_flag(sk, SOCK_RCVTSTAMPNS) && sock_flag(sk, SOCK_TSTAMP_NEW);
1409 		break;
1410 
1411 	case SO_TIMESTAMPING_OLD:
1412 		v.val = sk->sk_tsflags;
1413 		break;
1414 
1415 	case SO_RCVTIMEO_OLD:
1416 	case SO_RCVTIMEO_NEW:
1417 		lv = sock_get_timeout(sk->sk_rcvtimeo, &v, SO_RCVTIMEO_OLD == optname);
1418 		break;
1419 
1420 	case SO_SNDTIMEO_OLD:
1421 	case SO_SNDTIMEO_NEW:
1422 		lv = sock_get_timeout(sk->sk_sndtimeo, &v, SO_SNDTIMEO_OLD == optname);
1423 		break;
1424 
1425 	case SO_RCVLOWAT:
1426 		v.val = sk->sk_rcvlowat;
1427 		break;
1428 
1429 	case SO_SNDLOWAT:
1430 		v.val = 1;
1431 		break;
1432 
1433 	case SO_PASSCRED:
1434 		v.val = !!test_bit(SOCK_PASSCRED, &sock->flags);
1435 		break;
1436 
1437 	case SO_PEERCRED:
1438 	{
1439 		struct ucred peercred;
1440 		if (len > sizeof(peercred))
1441 			len = sizeof(peercred);
1442 		cred_to_ucred(sk->sk_peer_pid, sk->sk_peer_cred, &peercred);
1443 		if (copy_to_user(optval, &peercred, len))
1444 			return -EFAULT;
1445 		goto lenout;
1446 	}
1447 
1448 	case SO_PEERGROUPS:
1449 	{
1450 		int ret, n;
1451 
1452 		if (!sk->sk_peer_cred)
1453 			return -ENODATA;
1454 
1455 		n = sk->sk_peer_cred->group_info->ngroups;
1456 		if (len < n * sizeof(gid_t)) {
1457 			len = n * sizeof(gid_t);
1458 			return put_user(len, optlen) ? -EFAULT : -ERANGE;
1459 		}
1460 		len = n * sizeof(gid_t);
1461 
1462 		ret = groups_to_user((gid_t __user *)optval,
1463 				     sk->sk_peer_cred->group_info);
1464 		if (ret)
1465 			return ret;
1466 		goto lenout;
1467 	}
1468 
1469 	case SO_PEERNAME:
1470 	{
1471 		char address[128];
1472 
1473 		lv = sock->ops->getname(sock, (struct sockaddr *)address, 2);
1474 		if (lv < 0)
1475 			return -ENOTCONN;
1476 		if (lv < len)
1477 			return -EINVAL;
1478 		if (copy_to_user(optval, address, len))
1479 			return -EFAULT;
1480 		goto lenout;
1481 	}
1482 
1483 	/* Dubious BSD thing... Probably nobody even uses it, but
1484 	 * the UNIX standard wants it for whatever reason... -DaveM
1485 	 */
1486 	case SO_ACCEPTCONN:
1487 		v.val = sk->sk_state == TCP_LISTEN;
1488 		break;
1489 
1490 	case SO_PASSSEC:
1491 		v.val = !!test_bit(SOCK_PASSSEC, &sock->flags);
1492 		break;
1493 
1494 	case SO_PEERSEC:
1495 		return security_socket_getpeersec_stream(sock, optval, optlen, len);
1496 
1497 	case SO_MARK:
1498 		v.val = sk->sk_mark;
1499 		break;
1500 
1501 	case SO_RXQ_OVFL:
1502 		v.val = sock_flag(sk, SOCK_RXQ_OVFL);
1503 		break;
1504 
1505 	case SO_WIFI_STATUS:
1506 		v.val = sock_flag(sk, SOCK_WIFI_STATUS);
1507 		break;
1508 
1509 	case SO_PEEK_OFF:
1510 		if (!sock->ops->set_peek_off)
1511 			return -EOPNOTSUPP;
1512 
1513 		v.val = sk->sk_peek_off;
1514 		break;
1515 	case SO_NOFCS:
1516 		v.val = sock_flag(sk, SOCK_NOFCS);
1517 		break;
1518 
1519 	case SO_BINDTODEVICE:
1520 		return sock_getbindtodevice(sk, optval, optlen, len);
1521 
1522 	case SO_GET_FILTER:
1523 		len = sk_get_filter(sk, (struct sock_filter __user *)optval, len);
1524 		if (len < 0)
1525 			return len;
1526 
1527 		goto lenout;
1528 
1529 	case SO_LOCK_FILTER:
1530 		v.val = sock_flag(sk, SOCK_FILTER_LOCKED);
1531 		break;
1532 
1533 	case SO_BPF_EXTENSIONS:
1534 		v.val = bpf_tell_extensions();
1535 		break;
1536 
1537 	case SO_SELECT_ERR_QUEUE:
1538 		v.val = sock_flag(sk, SOCK_SELECT_ERR_QUEUE);
1539 		break;
1540 
1541 #ifdef CONFIG_NET_RX_BUSY_POLL
1542 	case SO_BUSY_POLL:
1543 		v.val = sk->sk_ll_usec;
1544 		break;
1545 #endif
1546 
1547 	case SO_MAX_PACING_RATE:
1548 		if (sizeof(v.ulval) != sizeof(v.val) && len >= sizeof(v.ulval)) {
1549 			lv = sizeof(v.ulval);
1550 			v.ulval = sk->sk_max_pacing_rate;
1551 		} else {
1552 			/* 32bit version */
1553 			v.val = min_t(unsigned long, sk->sk_max_pacing_rate, ~0U);
1554 		}
1555 		break;
1556 
1557 	case SO_INCOMING_CPU:
1558 		v.val = READ_ONCE(sk->sk_incoming_cpu);
1559 		break;
1560 
1561 	case SO_MEMINFO:
1562 	{
1563 		u32 meminfo[SK_MEMINFO_VARS];
1564 
1565 		sk_get_meminfo(sk, meminfo);
1566 
1567 		len = min_t(unsigned int, len, sizeof(meminfo));
1568 		if (copy_to_user(optval, &meminfo, len))
1569 			return -EFAULT;
1570 
1571 		goto lenout;
1572 	}
1573 
1574 #ifdef CONFIG_NET_RX_BUSY_POLL
1575 	case SO_INCOMING_NAPI_ID:
1576 		v.val = READ_ONCE(sk->sk_napi_id);
1577 
1578 		/* aggregate non-NAPI IDs down to 0 */
1579 		if (v.val < MIN_NAPI_ID)
1580 			v.val = 0;
1581 
1582 		break;
1583 #endif
1584 
1585 	case SO_COOKIE:
1586 		lv = sizeof(u64);
1587 		if (len < lv)
1588 			return -EINVAL;
1589 		v.val64 = sock_gen_cookie(sk);
1590 		break;
1591 
1592 	case SO_ZEROCOPY:
1593 		v.val = sock_flag(sk, SOCK_ZEROCOPY);
1594 		break;
1595 
1596 	case SO_TXTIME:
1597 		lv = sizeof(v.txtime);
1598 		v.txtime.clockid = sk->sk_clockid;
1599 		v.txtime.flags |= sk->sk_txtime_deadline_mode ?
1600 				  SOF_TXTIME_DEADLINE_MODE : 0;
1601 		v.txtime.flags |= sk->sk_txtime_report_errors ?
1602 				  SOF_TXTIME_REPORT_ERRORS : 0;
1603 		break;
1604 
1605 	case SO_BINDTOIFINDEX:
1606 		v.val = sk->sk_bound_dev_if;
1607 		break;
1608 
1609 	default:
1610 		/* We implement the SO_SNDLOWAT etc to not be settable
1611 		 * (1003.1g 7).
1612 		 */
1613 		return -ENOPROTOOPT;
1614 	}
1615 
1616 	if (len > lv)
1617 		len = lv;
1618 	if (copy_to_user(optval, &v, len))
1619 		return -EFAULT;
1620 lenout:
1621 	if (put_user(len, optlen))
1622 		return -EFAULT;
1623 	return 0;
1624 }
1625 
1626 /*
1627  * Initialize an sk_lock.
1628  *
1629  * (We also register the sk_lock with the lock validator.)
1630  */
1631 static inline void sock_lock_init(struct sock *sk)
1632 {
1633 	if (sk->sk_kern_sock)
1634 		sock_lock_init_class_and_name(
1635 			sk,
1636 			af_family_kern_slock_key_strings[sk->sk_family],
1637 			af_family_kern_slock_keys + sk->sk_family,
1638 			af_family_kern_key_strings[sk->sk_family],
1639 			af_family_kern_keys + sk->sk_family);
1640 	else
1641 		sock_lock_init_class_and_name(
1642 			sk,
1643 			af_family_slock_key_strings[sk->sk_family],
1644 			af_family_slock_keys + sk->sk_family,
1645 			af_family_key_strings[sk->sk_family],
1646 			af_family_keys + sk->sk_family);
1647 }
1648 
1649 /*
1650  * Copy all fields from osk to nsk but nsk->sk_refcnt must not change yet,
1651  * even temporarly, because of RCU lookups. sk_node should also be left as is.
1652  * We must not copy fields between sk_dontcopy_begin and sk_dontcopy_end
1653  */
1654 static void sock_copy(struct sock *nsk, const struct sock *osk)
1655 {
1656 	const struct proto *prot = READ_ONCE(osk->sk_prot);
1657 #ifdef CONFIG_SECURITY_NETWORK
1658 	void *sptr = nsk->sk_security;
1659 #endif
1660 	memcpy(nsk, osk, offsetof(struct sock, sk_dontcopy_begin));
1661 
1662 	memcpy(&nsk->sk_dontcopy_end, &osk->sk_dontcopy_end,
1663 	       prot->obj_size - offsetof(struct sock, sk_dontcopy_end));
1664 
1665 #ifdef CONFIG_SECURITY_NETWORK
1666 	nsk->sk_security = sptr;
1667 	security_sk_clone(osk, nsk);
1668 #endif
1669 }
1670 
1671 static struct sock *sk_prot_alloc(struct proto *prot, gfp_t priority,
1672 		int family)
1673 {
1674 	struct sock *sk;
1675 	struct kmem_cache *slab;
1676 
1677 	slab = prot->slab;
1678 	if (slab != NULL) {
1679 		sk = kmem_cache_alloc(slab, priority & ~__GFP_ZERO);
1680 		if (!sk)
1681 			return sk;
1682 		if (want_init_on_alloc(priority))
1683 			sk_prot_clear_nulls(sk, prot->obj_size);
1684 	} else
1685 		sk = kmalloc(prot->obj_size, priority);
1686 
1687 	if (sk != NULL) {
1688 		if (security_sk_alloc(sk, family, priority))
1689 			goto out_free;
1690 
1691 		if (!try_module_get(prot->owner))
1692 			goto out_free_sec;
1693 		sk_tx_queue_clear(sk);
1694 	}
1695 
1696 	return sk;
1697 
1698 out_free_sec:
1699 	security_sk_free(sk);
1700 out_free:
1701 	if (slab != NULL)
1702 		kmem_cache_free(slab, sk);
1703 	else
1704 		kfree(sk);
1705 	return NULL;
1706 }
1707 
1708 static void sk_prot_free(struct proto *prot, struct sock *sk)
1709 {
1710 	struct kmem_cache *slab;
1711 	struct module *owner;
1712 
1713 	owner = prot->owner;
1714 	slab = prot->slab;
1715 
1716 	cgroup_sk_free(&sk->sk_cgrp_data);
1717 	mem_cgroup_sk_free(sk);
1718 	security_sk_free(sk);
1719 	if (slab != NULL)
1720 		kmem_cache_free(slab, sk);
1721 	else
1722 		kfree(sk);
1723 	module_put(owner);
1724 }
1725 
1726 /**
1727  *	sk_alloc - All socket objects are allocated here
1728  *	@net: the applicable net namespace
1729  *	@family: protocol family
1730  *	@priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
1731  *	@prot: struct proto associated with this new sock instance
1732  *	@kern: is this to be a kernel socket?
1733  */
1734 struct sock *sk_alloc(struct net *net, int family, gfp_t priority,
1735 		      struct proto *prot, int kern)
1736 {
1737 	struct sock *sk;
1738 
1739 	sk = sk_prot_alloc(prot, priority | __GFP_ZERO, family);
1740 	if (sk) {
1741 		sk->sk_family = family;
1742 		/*
1743 		 * See comment in struct sock definition to understand
1744 		 * why we need sk_prot_creator -acme
1745 		 */
1746 		sk->sk_prot = sk->sk_prot_creator = prot;
1747 		sk->sk_kern_sock = kern;
1748 		sock_lock_init(sk);
1749 		sk->sk_net_refcnt = kern ? 0 : 1;
1750 		if (likely(sk->sk_net_refcnt)) {
1751 			get_net(net);
1752 			sock_inuse_add(net, 1);
1753 		}
1754 
1755 		sock_net_set(sk, net);
1756 		refcount_set(&sk->sk_wmem_alloc, 1);
1757 
1758 		mem_cgroup_sk_alloc(sk);
1759 		cgroup_sk_alloc(&sk->sk_cgrp_data);
1760 		sock_update_classid(&sk->sk_cgrp_data);
1761 		sock_update_netprioidx(&sk->sk_cgrp_data);
1762 		sk_tx_queue_clear(sk);
1763 	}
1764 
1765 	return sk;
1766 }
1767 EXPORT_SYMBOL(sk_alloc);
1768 
1769 /* Sockets having SOCK_RCU_FREE will call this function after one RCU
1770  * grace period. This is the case for UDP sockets and TCP listeners.
1771  */
1772 static void __sk_destruct(struct rcu_head *head)
1773 {
1774 	struct sock *sk = container_of(head, struct sock, sk_rcu);
1775 	struct sk_filter *filter;
1776 
1777 	if (sk->sk_destruct)
1778 		sk->sk_destruct(sk);
1779 
1780 	filter = rcu_dereference_check(sk->sk_filter,
1781 				       refcount_read(&sk->sk_wmem_alloc) == 0);
1782 	if (filter) {
1783 		sk_filter_uncharge(sk, filter);
1784 		RCU_INIT_POINTER(sk->sk_filter, NULL);
1785 	}
1786 
1787 	sock_disable_timestamp(sk, SK_FLAGS_TIMESTAMP);
1788 
1789 #ifdef CONFIG_BPF_SYSCALL
1790 	bpf_sk_storage_free(sk);
1791 #endif
1792 
1793 	if (atomic_read(&sk->sk_omem_alloc))
1794 		pr_debug("%s: optmem leakage (%d bytes) detected\n",
1795 			 __func__, atomic_read(&sk->sk_omem_alloc));
1796 
1797 	if (sk->sk_frag.page) {
1798 		put_page(sk->sk_frag.page);
1799 		sk->sk_frag.page = NULL;
1800 	}
1801 
1802 	if (sk->sk_peer_cred)
1803 		put_cred(sk->sk_peer_cred);
1804 	put_pid(sk->sk_peer_pid);
1805 	if (likely(sk->sk_net_refcnt))
1806 		put_net(sock_net(sk));
1807 	sk_prot_free(sk->sk_prot_creator, sk);
1808 }
1809 
1810 void sk_destruct(struct sock *sk)
1811 {
1812 	bool use_call_rcu = sock_flag(sk, SOCK_RCU_FREE);
1813 
1814 	if (rcu_access_pointer(sk->sk_reuseport_cb)) {
1815 		reuseport_detach_sock(sk);
1816 		use_call_rcu = true;
1817 	}
1818 
1819 	if (use_call_rcu)
1820 		call_rcu(&sk->sk_rcu, __sk_destruct);
1821 	else
1822 		__sk_destruct(&sk->sk_rcu);
1823 }
1824 
1825 static void __sk_free(struct sock *sk)
1826 {
1827 	if (likely(sk->sk_net_refcnt))
1828 		sock_inuse_add(sock_net(sk), -1);
1829 
1830 	if (unlikely(sk->sk_net_refcnt && sock_diag_has_destroy_listeners(sk)))
1831 		sock_diag_broadcast_destroy(sk);
1832 	else
1833 		sk_destruct(sk);
1834 }
1835 
1836 void sk_free(struct sock *sk)
1837 {
1838 	/*
1839 	 * We subtract one from sk_wmem_alloc and can know if
1840 	 * some packets are still in some tx queue.
1841 	 * If not null, sock_wfree() will call __sk_free(sk) later
1842 	 */
1843 	if (refcount_dec_and_test(&sk->sk_wmem_alloc))
1844 		__sk_free(sk);
1845 }
1846 EXPORT_SYMBOL(sk_free);
1847 
1848 static void sk_init_common(struct sock *sk)
1849 {
1850 	skb_queue_head_init(&sk->sk_receive_queue);
1851 	skb_queue_head_init(&sk->sk_write_queue);
1852 	skb_queue_head_init(&sk->sk_error_queue);
1853 
1854 	rwlock_init(&sk->sk_callback_lock);
1855 	lockdep_set_class_and_name(&sk->sk_receive_queue.lock,
1856 			af_rlock_keys + sk->sk_family,
1857 			af_family_rlock_key_strings[sk->sk_family]);
1858 	lockdep_set_class_and_name(&sk->sk_write_queue.lock,
1859 			af_wlock_keys + sk->sk_family,
1860 			af_family_wlock_key_strings[sk->sk_family]);
1861 	lockdep_set_class_and_name(&sk->sk_error_queue.lock,
1862 			af_elock_keys + sk->sk_family,
1863 			af_family_elock_key_strings[sk->sk_family]);
1864 	lockdep_set_class_and_name(&sk->sk_callback_lock,
1865 			af_callback_keys + sk->sk_family,
1866 			af_family_clock_key_strings[sk->sk_family]);
1867 }
1868 
1869 /**
1870  *	sk_clone_lock - clone a socket, and lock its clone
1871  *	@sk: the socket to clone
1872  *	@priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
1873  *
1874  *	Caller must unlock socket even in error path (bh_unlock_sock(newsk))
1875  */
1876 struct sock *sk_clone_lock(const struct sock *sk, const gfp_t priority)
1877 {
1878 	struct proto *prot = READ_ONCE(sk->sk_prot);
1879 	struct sock *newsk;
1880 	bool is_charged = true;
1881 
1882 	newsk = sk_prot_alloc(prot, priority, sk->sk_family);
1883 	if (newsk != NULL) {
1884 		struct sk_filter *filter;
1885 
1886 		sock_copy(newsk, sk);
1887 
1888 		newsk->sk_prot_creator = prot;
1889 
1890 		/* SANITY */
1891 		if (likely(newsk->sk_net_refcnt))
1892 			get_net(sock_net(newsk));
1893 		sk_node_init(&newsk->sk_node);
1894 		sock_lock_init(newsk);
1895 		bh_lock_sock(newsk);
1896 		newsk->sk_backlog.head	= newsk->sk_backlog.tail = NULL;
1897 		newsk->sk_backlog.len = 0;
1898 
1899 		atomic_set(&newsk->sk_rmem_alloc, 0);
1900 		/*
1901 		 * sk_wmem_alloc set to one (see sk_free() and sock_wfree())
1902 		 */
1903 		refcount_set(&newsk->sk_wmem_alloc, 1);
1904 		atomic_set(&newsk->sk_omem_alloc, 0);
1905 		sk_init_common(newsk);
1906 
1907 		newsk->sk_dst_cache	= NULL;
1908 		newsk->sk_dst_pending_confirm = 0;
1909 		newsk->sk_wmem_queued	= 0;
1910 		newsk->sk_forward_alloc = 0;
1911 		atomic_set(&newsk->sk_drops, 0);
1912 		newsk->sk_send_head	= NULL;
1913 		newsk->sk_userlocks	= sk->sk_userlocks & ~SOCK_BINDPORT_LOCK;
1914 		atomic_set(&newsk->sk_zckey, 0);
1915 
1916 		sock_reset_flag(newsk, SOCK_DONE);
1917 
1918 		/* sk->sk_memcg will be populated at accept() time */
1919 		newsk->sk_memcg = NULL;
1920 
1921 		cgroup_sk_clone(&newsk->sk_cgrp_data);
1922 
1923 		rcu_read_lock();
1924 		filter = rcu_dereference(sk->sk_filter);
1925 		if (filter != NULL)
1926 			/* though it's an empty new sock, the charging may fail
1927 			 * if sysctl_optmem_max was changed between creation of
1928 			 * original socket and cloning
1929 			 */
1930 			is_charged = sk_filter_charge(newsk, filter);
1931 		RCU_INIT_POINTER(newsk->sk_filter, filter);
1932 		rcu_read_unlock();
1933 
1934 		if (unlikely(!is_charged || xfrm_sk_clone_policy(newsk, sk))) {
1935 			/* We need to make sure that we don't uncharge the new
1936 			 * socket if we couldn't charge it in the first place
1937 			 * as otherwise we uncharge the parent's filter.
1938 			 */
1939 			if (!is_charged)
1940 				RCU_INIT_POINTER(newsk->sk_filter, NULL);
1941 			sk_free_unlock_clone(newsk);
1942 			newsk = NULL;
1943 			goto out;
1944 		}
1945 		RCU_INIT_POINTER(newsk->sk_reuseport_cb, NULL);
1946 
1947 		if (bpf_sk_storage_clone(sk, newsk)) {
1948 			sk_free_unlock_clone(newsk);
1949 			newsk = NULL;
1950 			goto out;
1951 		}
1952 
1953 		/* Clear sk_user_data if parent had the pointer tagged
1954 		 * as not suitable for copying when cloning.
1955 		 */
1956 		if (sk_user_data_is_nocopy(newsk))
1957 			newsk->sk_user_data = NULL;
1958 
1959 		newsk->sk_err	   = 0;
1960 		newsk->sk_err_soft = 0;
1961 		newsk->sk_priority = 0;
1962 		newsk->sk_incoming_cpu = raw_smp_processor_id();
1963 		if (likely(newsk->sk_net_refcnt))
1964 			sock_inuse_add(sock_net(newsk), 1);
1965 
1966 		/*
1967 		 * Before updating sk_refcnt, we must commit prior changes to memory
1968 		 * (Documentation/RCU/rculist_nulls.rst for details)
1969 		 */
1970 		smp_wmb();
1971 		refcount_set(&newsk->sk_refcnt, 2);
1972 
1973 		/*
1974 		 * Increment the counter in the same struct proto as the master
1975 		 * sock (sk_refcnt_debug_inc uses newsk->sk_prot->socks, that
1976 		 * is the same as sk->sk_prot->socks, as this field was copied
1977 		 * with memcpy).
1978 		 *
1979 		 * This _changes_ the previous behaviour, where
1980 		 * tcp_create_openreq_child always was incrementing the
1981 		 * equivalent to tcp_prot->socks (inet_sock_nr), so this have
1982 		 * to be taken into account in all callers. -acme
1983 		 */
1984 		sk_refcnt_debug_inc(newsk);
1985 		sk_set_socket(newsk, NULL);
1986 		sk_tx_queue_clear(newsk);
1987 		RCU_INIT_POINTER(newsk->sk_wq, NULL);
1988 
1989 		if (newsk->sk_prot->sockets_allocated)
1990 			sk_sockets_allocated_inc(newsk);
1991 
1992 		if (sock_needs_netstamp(sk) &&
1993 		    newsk->sk_flags & SK_FLAGS_TIMESTAMP)
1994 			net_enable_timestamp();
1995 	}
1996 out:
1997 	return newsk;
1998 }
1999 EXPORT_SYMBOL_GPL(sk_clone_lock);
2000 
2001 void sk_free_unlock_clone(struct sock *sk)
2002 {
2003 	/* It is still raw copy of parent, so invalidate
2004 	 * destructor and make plain sk_free() */
2005 	sk->sk_destruct = NULL;
2006 	bh_unlock_sock(sk);
2007 	sk_free(sk);
2008 }
2009 EXPORT_SYMBOL_GPL(sk_free_unlock_clone);
2010 
2011 void sk_setup_caps(struct sock *sk, struct dst_entry *dst)
2012 {
2013 	u32 max_segs = 1;
2014 
2015 	sk_dst_set(sk, dst);
2016 	sk->sk_route_caps = dst->dev->features | sk->sk_route_forced_caps;
2017 	if (sk->sk_route_caps & NETIF_F_GSO)
2018 		sk->sk_route_caps |= NETIF_F_GSO_SOFTWARE;
2019 	sk->sk_route_caps &= ~sk->sk_route_nocaps;
2020 	if (sk_can_gso(sk)) {
2021 		if (dst->header_len && !xfrm_dst_offload_ok(dst)) {
2022 			sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
2023 		} else {
2024 			sk->sk_route_caps |= NETIF_F_SG | NETIF_F_HW_CSUM;
2025 			sk->sk_gso_max_size = dst->dev->gso_max_size;
2026 			max_segs = max_t(u32, dst->dev->gso_max_segs, 1);
2027 		}
2028 	}
2029 	sk->sk_gso_max_segs = max_segs;
2030 }
2031 EXPORT_SYMBOL_GPL(sk_setup_caps);
2032 
2033 /*
2034  *	Simple resource managers for sockets.
2035  */
2036 
2037 
2038 /*
2039  * Write buffer destructor automatically called from kfree_skb.
2040  */
2041 void sock_wfree(struct sk_buff *skb)
2042 {
2043 	struct sock *sk = skb->sk;
2044 	unsigned int len = skb->truesize;
2045 
2046 	if (!sock_flag(sk, SOCK_USE_WRITE_QUEUE)) {
2047 		/*
2048 		 * Keep a reference on sk_wmem_alloc, this will be released
2049 		 * after sk_write_space() call
2050 		 */
2051 		WARN_ON(refcount_sub_and_test(len - 1, &sk->sk_wmem_alloc));
2052 		sk->sk_write_space(sk);
2053 		len = 1;
2054 	}
2055 	/*
2056 	 * if sk_wmem_alloc reaches 0, we must finish what sk_free()
2057 	 * could not do because of in-flight packets
2058 	 */
2059 	if (refcount_sub_and_test(len, &sk->sk_wmem_alloc))
2060 		__sk_free(sk);
2061 }
2062 EXPORT_SYMBOL(sock_wfree);
2063 
2064 /* This variant of sock_wfree() is used by TCP,
2065  * since it sets SOCK_USE_WRITE_QUEUE.
2066  */
2067 void __sock_wfree(struct sk_buff *skb)
2068 {
2069 	struct sock *sk = skb->sk;
2070 
2071 	if (refcount_sub_and_test(skb->truesize, &sk->sk_wmem_alloc))
2072 		__sk_free(sk);
2073 }
2074 
2075 void skb_set_owner_w(struct sk_buff *skb, struct sock *sk)
2076 {
2077 	skb_orphan(skb);
2078 	skb->sk = sk;
2079 #ifdef CONFIG_INET
2080 	if (unlikely(!sk_fullsock(sk))) {
2081 		skb->destructor = sock_edemux;
2082 		sock_hold(sk);
2083 		return;
2084 	}
2085 #endif
2086 	skb->destructor = sock_wfree;
2087 	skb_set_hash_from_sk(skb, sk);
2088 	/*
2089 	 * We used to take a refcount on sk, but following operation
2090 	 * is enough to guarantee sk_free() wont free this sock until
2091 	 * all in-flight packets are completed
2092 	 */
2093 	refcount_add(skb->truesize, &sk->sk_wmem_alloc);
2094 }
2095 EXPORT_SYMBOL(skb_set_owner_w);
2096 
2097 static bool can_skb_orphan_partial(const struct sk_buff *skb)
2098 {
2099 #ifdef CONFIG_TLS_DEVICE
2100 	/* Drivers depend on in-order delivery for crypto offload,
2101 	 * partial orphan breaks out-of-order-OK logic.
2102 	 */
2103 	if (skb->decrypted)
2104 		return false;
2105 #endif
2106 	return (skb->destructor == sock_wfree ||
2107 		(IS_ENABLED(CONFIG_INET) && skb->destructor == tcp_wfree));
2108 }
2109 
2110 /* This helper is used by netem, as it can hold packets in its
2111  * delay queue. We want to allow the owner socket to send more
2112  * packets, as if they were already TX completed by a typical driver.
2113  * But we also want to keep skb->sk set because some packet schedulers
2114  * rely on it (sch_fq for example).
2115  */
2116 void skb_orphan_partial(struct sk_buff *skb)
2117 {
2118 	if (skb_is_tcp_pure_ack(skb))
2119 		return;
2120 
2121 	if (can_skb_orphan_partial(skb)) {
2122 		struct sock *sk = skb->sk;
2123 
2124 		if (refcount_inc_not_zero(&sk->sk_refcnt)) {
2125 			WARN_ON(refcount_sub_and_test(skb->truesize, &sk->sk_wmem_alloc));
2126 			skb->destructor = sock_efree;
2127 		}
2128 	} else {
2129 		skb_orphan(skb);
2130 	}
2131 }
2132 EXPORT_SYMBOL(skb_orphan_partial);
2133 
2134 /*
2135  * Read buffer destructor automatically called from kfree_skb.
2136  */
2137 void sock_rfree(struct sk_buff *skb)
2138 {
2139 	struct sock *sk = skb->sk;
2140 	unsigned int len = skb->truesize;
2141 
2142 	atomic_sub(len, &sk->sk_rmem_alloc);
2143 	sk_mem_uncharge(sk, len);
2144 }
2145 EXPORT_SYMBOL(sock_rfree);
2146 
2147 /*
2148  * Buffer destructor for skbs that are not used directly in read or write
2149  * path, e.g. for error handler skbs. Automatically called from kfree_skb.
2150  */
2151 void sock_efree(struct sk_buff *skb)
2152 {
2153 	sock_put(skb->sk);
2154 }
2155 EXPORT_SYMBOL(sock_efree);
2156 
2157 /* Buffer destructor for prefetch/receive path where reference count may
2158  * not be held, e.g. for listen sockets.
2159  */
2160 #ifdef CONFIG_INET
2161 void sock_pfree(struct sk_buff *skb)
2162 {
2163 	if (sk_is_refcounted(skb->sk))
2164 		sock_gen_put(skb->sk);
2165 }
2166 EXPORT_SYMBOL(sock_pfree);
2167 #endif /* CONFIG_INET */
2168 
2169 kuid_t sock_i_uid(struct sock *sk)
2170 {
2171 	kuid_t uid;
2172 
2173 	read_lock_bh(&sk->sk_callback_lock);
2174 	uid = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_uid : GLOBAL_ROOT_UID;
2175 	read_unlock_bh(&sk->sk_callback_lock);
2176 	return uid;
2177 }
2178 EXPORT_SYMBOL(sock_i_uid);
2179 
2180 unsigned long sock_i_ino(struct sock *sk)
2181 {
2182 	unsigned long ino;
2183 
2184 	read_lock_bh(&sk->sk_callback_lock);
2185 	ino = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_ino : 0;
2186 	read_unlock_bh(&sk->sk_callback_lock);
2187 	return ino;
2188 }
2189 EXPORT_SYMBOL(sock_i_ino);
2190 
2191 /*
2192  * Allocate a skb from the socket's send buffer.
2193  */
2194 struct sk_buff *sock_wmalloc(struct sock *sk, unsigned long size, int force,
2195 			     gfp_t priority)
2196 {
2197 	if (force ||
2198 	    refcount_read(&sk->sk_wmem_alloc) < READ_ONCE(sk->sk_sndbuf)) {
2199 		struct sk_buff *skb = alloc_skb(size, priority);
2200 
2201 		if (skb) {
2202 			skb_set_owner_w(skb, sk);
2203 			return skb;
2204 		}
2205 	}
2206 	return NULL;
2207 }
2208 EXPORT_SYMBOL(sock_wmalloc);
2209 
2210 static void sock_ofree(struct sk_buff *skb)
2211 {
2212 	struct sock *sk = skb->sk;
2213 
2214 	atomic_sub(skb->truesize, &sk->sk_omem_alloc);
2215 }
2216 
2217 struct sk_buff *sock_omalloc(struct sock *sk, unsigned long size,
2218 			     gfp_t priority)
2219 {
2220 	struct sk_buff *skb;
2221 
2222 	/* small safe race: SKB_TRUESIZE may differ from final skb->truesize */
2223 	if (atomic_read(&sk->sk_omem_alloc) + SKB_TRUESIZE(size) >
2224 	    sysctl_optmem_max)
2225 		return NULL;
2226 
2227 	skb = alloc_skb(size, priority);
2228 	if (!skb)
2229 		return NULL;
2230 
2231 	atomic_add(skb->truesize, &sk->sk_omem_alloc);
2232 	skb->sk = sk;
2233 	skb->destructor = sock_ofree;
2234 	return skb;
2235 }
2236 
2237 /*
2238  * Allocate a memory block from the socket's option memory buffer.
2239  */
2240 void *sock_kmalloc(struct sock *sk, int size, gfp_t priority)
2241 {
2242 	if ((unsigned int)size <= sysctl_optmem_max &&
2243 	    atomic_read(&sk->sk_omem_alloc) + size < sysctl_optmem_max) {
2244 		void *mem;
2245 		/* First do the add, to avoid the race if kmalloc
2246 		 * might sleep.
2247 		 */
2248 		atomic_add(size, &sk->sk_omem_alloc);
2249 		mem = kmalloc(size, priority);
2250 		if (mem)
2251 			return mem;
2252 		atomic_sub(size, &sk->sk_omem_alloc);
2253 	}
2254 	return NULL;
2255 }
2256 EXPORT_SYMBOL(sock_kmalloc);
2257 
2258 /* Free an option memory block. Note, we actually want the inline
2259  * here as this allows gcc to detect the nullify and fold away the
2260  * condition entirely.
2261  */
2262 static inline void __sock_kfree_s(struct sock *sk, void *mem, int size,
2263 				  const bool nullify)
2264 {
2265 	if (WARN_ON_ONCE(!mem))
2266 		return;
2267 	if (nullify)
2268 		kfree_sensitive(mem);
2269 	else
2270 		kfree(mem);
2271 	atomic_sub(size, &sk->sk_omem_alloc);
2272 }
2273 
2274 void sock_kfree_s(struct sock *sk, void *mem, int size)
2275 {
2276 	__sock_kfree_s(sk, mem, size, false);
2277 }
2278 EXPORT_SYMBOL(sock_kfree_s);
2279 
2280 void sock_kzfree_s(struct sock *sk, void *mem, int size)
2281 {
2282 	__sock_kfree_s(sk, mem, size, true);
2283 }
2284 EXPORT_SYMBOL(sock_kzfree_s);
2285 
2286 /* It is almost wait_for_tcp_memory minus release_sock/lock_sock.
2287    I think, these locks should be removed for datagram sockets.
2288  */
2289 static long sock_wait_for_wmem(struct sock *sk, long timeo)
2290 {
2291 	DEFINE_WAIT(wait);
2292 
2293 	sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
2294 	for (;;) {
2295 		if (!timeo)
2296 			break;
2297 		if (signal_pending(current))
2298 			break;
2299 		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
2300 		prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
2301 		if (refcount_read(&sk->sk_wmem_alloc) < READ_ONCE(sk->sk_sndbuf))
2302 			break;
2303 		if (sk->sk_shutdown & SEND_SHUTDOWN)
2304 			break;
2305 		if (sk->sk_err)
2306 			break;
2307 		timeo = schedule_timeout(timeo);
2308 	}
2309 	finish_wait(sk_sleep(sk), &wait);
2310 	return timeo;
2311 }
2312 
2313 
2314 /*
2315  *	Generic send/receive buffer handlers
2316  */
2317 
2318 struct sk_buff *sock_alloc_send_pskb(struct sock *sk, unsigned long header_len,
2319 				     unsigned long data_len, int noblock,
2320 				     int *errcode, int max_page_order)
2321 {
2322 	struct sk_buff *skb;
2323 	long timeo;
2324 	int err;
2325 
2326 	timeo = sock_sndtimeo(sk, noblock);
2327 	for (;;) {
2328 		err = sock_error(sk);
2329 		if (err != 0)
2330 			goto failure;
2331 
2332 		err = -EPIPE;
2333 		if (sk->sk_shutdown & SEND_SHUTDOWN)
2334 			goto failure;
2335 
2336 		if (sk_wmem_alloc_get(sk) < READ_ONCE(sk->sk_sndbuf))
2337 			break;
2338 
2339 		sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
2340 		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
2341 		err = -EAGAIN;
2342 		if (!timeo)
2343 			goto failure;
2344 		if (signal_pending(current))
2345 			goto interrupted;
2346 		timeo = sock_wait_for_wmem(sk, timeo);
2347 	}
2348 	skb = alloc_skb_with_frags(header_len, data_len, max_page_order,
2349 				   errcode, sk->sk_allocation);
2350 	if (skb)
2351 		skb_set_owner_w(skb, sk);
2352 	return skb;
2353 
2354 interrupted:
2355 	err = sock_intr_errno(timeo);
2356 failure:
2357 	*errcode = err;
2358 	return NULL;
2359 }
2360 EXPORT_SYMBOL(sock_alloc_send_pskb);
2361 
2362 struct sk_buff *sock_alloc_send_skb(struct sock *sk, unsigned long size,
2363 				    int noblock, int *errcode)
2364 {
2365 	return sock_alloc_send_pskb(sk, size, 0, noblock, errcode, 0);
2366 }
2367 EXPORT_SYMBOL(sock_alloc_send_skb);
2368 
2369 int __sock_cmsg_send(struct sock *sk, struct msghdr *msg, struct cmsghdr *cmsg,
2370 		     struct sockcm_cookie *sockc)
2371 {
2372 	u32 tsflags;
2373 
2374 	switch (cmsg->cmsg_type) {
2375 	case SO_MARK:
2376 		if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
2377 			return -EPERM;
2378 		if (cmsg->cmsg_len != CMSG_LEN(sizeof(u32)))
2379 			return -EINVAL;
2380 		sockc->mark = *(u32 *)CMSG_DATA(cmsg);
2381 		break;
2382 	case SO_TIMESTAMPING_OLD:
2383 		if (cmsg->cmsg_len != CMSG_LEN(sizeof(u32)))
2384 			return -EINVAL;
2385 
2386 		tsflags = *(u32 *)CMSG_DATA(cmsg);
2387 		if (tsflags & ~SOF_TIMESTAMPING_TX_RECORD_MASK)
2388 			return -EINVAL;
2389 
2390 		sockc->tsflags &= ~SOF_TIMESTAMPING_TX_RECORD_MASK;
2391 		sockc->tsflags |= tsflags;
2392 		break;
2393 	case SCM_TXTIME:
2394 		if (!sock_flag(sk, SOCK_TXTIME))
2395 			return -EINVAL;
2396 		if (cmsg->cmsg_len != CMSG_LEN(sizeof(u64)))
2397 			return -EINVAL;
2398 		sockc->transmit_time = get_unaligned((u64 *)CMSG_DATA(cmsg));
2399 		break;
2400 	/* SCM_RIGHTS and SCM_CREDENTIALS are semantically in SOL_UNIX. */
2401 	case SCM_RIGHTS:
2402 	case SCM_CREDENTIALS:
2403 		break;
2404 	default:
2405 		return -EINVAL;
2406 	}
2407 	return 0;
2408 }
2409 EXPORT_SYMBOL(__sock_cmsg_send);
2410 
2411 int sock_cmsg_send(struct sock *sk, struct msghdr *msg,
2412 		   struct sockcm_cookie *sockc)
2413 {
2414 	struct cmsghdr *cmsg;
2415 	int ret;
2416 
2417 	for_each_cmsghdr(cmsg, msg) {
2418 		if (!CMSG_OK(msg, cmsg))
2419 			return -EINVAL;
2420 		if (cmsg->cmsg_level != SOL_SOCKET)
2421 			continue;
2422 		ret = __sock_cmsg_send(sk, msg, cmsg, sockc);
2423 		if (ret)
2424 			return ret;
2425 	}
2426 	return 0;
2427 }
2428 EXPORT_SYMBOL(sock_cmsg_send);
2429 
2430 static void sk_enter_memory_pressure(struct sock *sk)
2431 {
2432 	if (!sk->sk_prot->enter_memory_pressure)
2433 		return;
2434 
2435 	sk->sk_prot->enter_memory_pressure(sk);
2436 }
2437 
2438 static void sk_leave_memory_pressure(struct sock *sk)
2439 {
2440 	if (sk->sk_prot->leave_memory_pressure) {
2441 		sk->sk_prot->leave_memory_pressure(sk);
2442 	} else {
2443 		unsigned long *memory_pressure = sk->sk_prot->memory_pressure;
2444 
2445 		if (memory_pressure && READ_ONCE(*memory_pressure))
2446 			WRITE_ONCE(*memory_pressure, 0);
2447 	}
2448 }
2449 
2450 #define SKB_FRAG_PAGE_ORDER	get_order(32768)
2451 DEFINE_STATIC_KEY_FALSE(net_high_order_alloc_disable_key);
2452 
2453 /**
2454  * skb_page_frag_refill - check that a page_frag contains enough room
2455  * @sz: minimum size of the fragment we want to get
2456  * @pfrag: pointer to page_frag
2457  * @gfp: priority for memory allocation
2458  *
2459  * Note: While this allocator tries to use high order pages, there is
2460  * no guarantee that allocations succeed. Therefore, @sz MUST be
2461  * less or equal than PAGE_SIZE.
2462  */
2463 bool skb_page_frag_refill(unsigned int sz, struct page_frag *pfrag, gfp_t gfp)
2464 {
2465 	if (pfrag->page) {
2466 		if (page_ref_count(pfrag->page) == 1) {
2467 			pfrag->offset = 0;
2468 			return true;
2469 		}
2470 		if (pfrag->offset + sz <= pfrag->size)
2471 			return true;
2472 		put_page(pfrag->page);
2473 	}
2474 
2475 	pfrag->offset = 0;
2476 	if (SKB_FRAG_PAGE_ORDER &&
2477 	    !static_branch_unlikely(&net_high_order_alloc_disable_key)) {
2478 		/* Avoid direct reclaim but allow kswapd to wake */
2479 		pfrag->page = alloc_pages((gfp & ~__GFP_DIRECT_RECLAIM) |
2480 					  __GFP_COMP | __GFP_NOWARN |
2481 					  __GFP_NORETRY,
2482 					  SKB_FRAG_PAGE_ORDER);
2483 		if (likely(pfrag->page)) {
2484 			pfrag->size = PAGE_SIZE << SKB_FRAG_PAGE_ORDER;
2485 			return true;
2486 		}
2487 	}
2488 	pfrag->page = alloc_page(gfp);
2489 	if (likely(pfrag->page)) {
2490 		pfrag->size = PAGE_SIZE;
2491 		return true;
2492 	}
2493 	return false;
2494 }
2495 EXPORT_SYMBOL(skb_page_frag_refill);
2496 
2497 bool sk_page_frag_refill(struct sock *sk, struct page_frag *pfrag)
2498 {
2499 	if (likely(skb_page_frag_refill(32U, pfrag, sk->sk_allocation)))
2500 		return true;
2501 
2502 	sk_enter_memory_pressure(sk);
2503 	sk_stream_moderate_sndbuf(sk);
2504 	return false;
2505 }
2506 EXPORT_SYMBOL(sk_page_frag_refill);
2507 
2508 static void __lock_sock(struct sock *sk)
2509 	__releases(&sk->sk_lock.slock)
2510 	__acquires(&sk->sk_lock.slock)
2511 {
2512 	DEFINE_WAIT(wait);
2513 
2514 	for (;;) {
2515 		prepare_to_wait_exclusive(&sk->sk_lock.wq, &wait,
2516 					TASK_UNINTERRUPTIBLE);
2517 		spin_unlock_bh(&sk->sk_lock.slock);
2518 		schedule();
2519 		spin_lock_bh(&sk->sk_lock.slock);
2520 		if (!sock_owned_by_user(sk))
2521 			break;
2522 	}
2523 	finish_wait(&sk->sk_lock.wq, &wait);
2524 }
2525 
2526 void __release_sock(struct sock *sk)
2527 	__releases(&sk->sk_lock.slock)
2528 	__acquires(&sk->sk_lock.slock)
2529 {
2530 	struct sk_buff *skb, *next;
2531 
2532 	while ((skb = sk->sk_backlog.head) != NULL) {
2533 		sk->sk_backlog.head = sk->sk_backlog.tail = NULL;
2534 
2535 		spin_unlock_bh(&sk->sk_lock.slock);
2536 
2537 		do {
2538 			next = skb->next;
2539 			prefetch(next);
2540 			WARN_ON_ONCE(skb_dst_is_noref(skb));
2541 			skb_mark_not_on_list(skb);
2542 			sk_backlog_rcv(sk, skb);
2543 
2544 			cond_resched();
2545 
2546 			skb = next;
2547 		} while (skb != NULL);
2548 
2549 		spin_lock_bh(&sk->sk_lock.slock);
2550 	}
2551 
2552 	/*
2553 	 * Doing the zeroing here guarantee we can not loop forever
2554 	 * while a wild producer attempts to flood us.
2555 	 */
2556 	sk->sk_backlog.len = 0;
2557 }
2558 
2559 void __sk_flush_backlog(struct sock *sk)
2560 {
2561 	spin_lock_bh(&sk->sk_lock.slock);
2562 	__release_sock(sk);
2563 	spin_unlock_bh(&sk->sk_lock.slock);
2564 }
2565 
2566 /**
2567  * sk_wait_data - wait for data to arrive at sk_receive_queue
2568  * @sk:    sock to wait on
2569  * @timeo: for how long
2570  * @skb:   last skb seen on sk_receive_queue
2571  *
2572  * Now socket state including sk->sk_err is changed only under lock,
2573  * hence we may omit checks after joining wait queue.
2574  * We check receive queue before schedule() only as optimization;
2575  * it is very likely that release_sock() added new data.
2576  */
2577 int sk_wait_data(struct sock *sk, long *timeo, const struct sk_buff *skb)
2578 {
2579 	DEFINE_WAIT_FUNC(wait, woken_wake_function);
2580 	int rc;
2581 
2582 	add_wait_queue(sk_sleep(sk), &wait);
2583 	sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
2584 	rc = sk_wait_event(sk, timeo, skb_peek_tail(&sk->sk_receive_queue) != skb, &wait);
2585 	sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
2586 	remove_wait_queue(sk_sleep(sk), &wait);
2587 	return rc;
2588 }
2589 EXPORT_SYMBOL(sk_wait_data);
2590 
2591 /**
2592  *	__sk_mem_raise_allocated - increase memory_allocated
2593  *	@sk: socket
2594  *	@size: memory size to allocate
2595  *	@amt: pages to allocate
2596  *	@kind: allocation type
2597  *
2598  *	Similar to __sk_mem_schedule(), but does not update sk_forward_alloc
2599  */
2600 int __sk_mem_raise_allocated(struct sock *sk, int size, int amt, int kind)
2601 {
2602 	struct proto *prot = sk->sk_prot;
2603 	long allocated = sk_memory_allocated_add(sk, amt);
2604 	bool charged = true;
2605 
2606 	if (mem_cgroup_sockets_enabled && sk->sk_memcg &&
2607 	    !(charged = mem_cgroup_charge_skmem(sk->sk_memcg, amt)))
2608 		goto suppress_allocation;
2609 
2610 	/* Under limit. */
2611 	if (allocated <= sk_prot_mem_limits(sk, 0)) {
2612 		sk_leave_memory_pressure(sk);
2613 		return 1;
2614 	}
2615 
2616 	/* Under pressure. */
2617 	if (allocated > sk_prot_mem_limits(sk, 1))
2618 		sk_enter_memory_pressure(sk);
2619 
2620 	/* Over hard limit. */
2621 	if (allocated > sk_prot_mem_limits(sk, 2))
2622 		goto suppress_allocation;
2623 
2624 	/* guarantee minimum buffer size under pressure */
2625 	if (kind == SK_MEM_RECV) {
2626 		if (atomic_read(&sk->sk_rmem_alloc) < sk_get_rmem0(sk, prot))
2627 			return 1;
2628 
2629 	} else { /* SK_MEM_SEND */
2630 		int wmem0 = sk_get_wmem0(sk, prot);
2631 
2632 		if (sk->sk_type == SOCK_STREAM) {
2633 			if (sk->sk_wmem_queued < wmem0)
2634 				return 1;
2635 		} else if (refcount_read(&sk->sk_wmem_alloc) < wmem0) {
2636 				return 1;
2637 		}
2638 	}
2639 
2640 	if (sk_has_memory_pressure(sk)) {
2641 		u64 alloc;
2642 
2643 		if (!sk_under_memory_pressure(sk))
2644 			return 1;
2645 		alloc = sk_sockets_allocated_read_positive(sk);
2646 		if (sk_prot_mem_limits(sk, 2) > alloc *
2647 		    sk_mem_pages(sk->sk_wmem_queued +
2648 				 atomic_read(&sk->sk_rmem_alloc) +
2649 				 sk->sk_forward_alloc))
2650 			return 1;
2651 	}
2652 
2653 suppress_allocation:
2654 
2655 	if (kind == SK_MEM_SEND && sk->sk_type == SOCK_STREAM) {
2656 		sk_stream_moderate_sndbuf(sk);
2657 
2658 		/* Fail only if socket is _under_ its sndbuf.
2659 		 * In this case we cannot block, so that we have to fail.
2660 		 */
2661 		if (sk->sk_wmem_queued + size >= sk->sk_sndbuf)
2662 			return 1;
2663 	}
2664 
2665 	if (kind == SK_MEM_SEND || (kind == SK_MEM_RECV && charged))
2666 		trace_sock_exceed_buf_limit(sk, prot, allocated, kind);
2667 
2668 	sk_memory_allocated_sub(sk, amt);
2669 
2670 	if (mem_cgroup_sockets_enabled && sk->sk_memcg)
2671 		mem_cgroup_uncharge_skmem(sk->sk_memcg, amt);
2672 
2673 	return 0;
2674 }
2675 EXPORT_SYMBOL(__sk_mem_raise_allocated);
2676 
2677 /**
2678  *	__sk_mem_schedule - increase sk_forward_alloc and memory_allocated
2679  *	@sk: socket
2680  *	@size: memory size to allocate
2681  *	@kind: allocation type
2682  *
2683  *	If kind is SK_MEM_SEND, it means wmem allocation. Otherwise it means
2684  *	rmem allocation. This function assumes that protocols which have
2685  *	memory_pressure use sk_wmem_queued as write buffer accounting.
2686  */
2687 int __sk_mem_schedule(struct sock *sk, int size, int kind)
2688 {
2689 	int ret, amt = sk_mem_pages(size);
2690 
2691 	sk->sk_forward_alloc += amt << SK_MEM_QUANTUM_SHIFT;
2692 	ret = __sk_mem_raise_allocated(sk, size, amt, kind);
2693 	if (!ret)
2694 		sk->sk_forward_alloc -= amt << SK_MEM_QUANTUM_SHIFT;
2695 	return ret;
2696 }
2697 EXPORT_SYMBOL(__sk_mem_schedule);
2698 
2699 /**
2700  *	__sk_mem_reduce_allocated - reclaim memory_allocated
2701  *	@sk: socket
2702  *	@amount: number of quanta
2703  *
2704  *	Similar to __sk_mem_reclaim(), but does not update sk_forward_alloc
2705  */
2706 void __sk_mem_reduce_allocated(struct sock *sk, int amount)
2707 {
2708 	sk_memory_allocated_sub(sk, amount);
2709 
2710 	if (mem_cgroup_sockets_enabled && sk->sk_memcg)
2711 		mem_cgroup_uncharge_skmem(sk->sk_memcg, amount);
2712 
2713 	if (sk_under_memory_pressure(sk) &&
2714 	    (sk_memory_allocated(sk) < sk_prot_mem_limits(sk, 0)))
2715 		sk_leave_memory_pressure(sk);
2716 }
2717 EXPORT_SYMBOL(__sk_mem_reduce_allocated);
2718 
2719 /**
2720  *	__sk_mem_reclaim - reclaim sk_forward_alloc and memory_allocated
2721  *	@sk: socket
2722  *	@amount: number of bytes (rounded down to a SK_MEM_QUANTUM multiple)
2723  */
2724 void __sk_mem_reclaim(struct sock *sk, int amount)
2725 {
2726 	amount >>= SK_MEM_QUANTUM_SHIFT;
2727 	sk->sk_forward_alloc -= amount << SK_MEM_QUANTUM_SHIFT;
2728 	__sk_mem_reduce_allocated(sk, amount);
2729 }
2730 EXPORT_SYMBOL(__sk_mem_reclaim);
2731 
2732 int sk_set_peek_off(struct sock *sk, int val)
2733 {
2734 	sk->sk_peek_off = val;
2735 	return 0;
2736 }
2737 EXPORT_SYMBOL_GPL(sk_set_peek_off);
2738 
2739 /*
2740  * Set of default routines for initialising struct proto_ops when
2741  * the protocol does not support a particular function. In certain
2742  * cases where it makes no sense for a protocol to have a "do nothing"
2743  * function, some default processing is provided.
2744  */
2745 
2746 int sock_no_bind(struct socket *sock, struct sockaddr *saddr, int len)
2747 {
2748 	return -EOPNOTSUPP;
2749 }
2750 EXPORT_SYMBOL(sock_no_bind);
2751 
2752 int sock_no_connect(struct socket *sock, struct sockaddr *saddr,
2753 		    int len, int flags)
2754 {
2755 	return -EOPNOTSUPP;
2756 }
2757 EXPORT_SYMBOL(sock_no_connect);
2758 
2759 int sock_no_socketpair(struct socket *sock1, struct socket *sock2)
2760 {
2761 	return -EOPNOTSUPP;
2762 }
2763 EXPORT_SYMBOL(sock_no_socketpair);
2764 
2765 int sock_no_accept(struct socket *sock, struct socket *newsock, int flags,
2766 		   bool kern)
2767 {
2768 	return -EOPNOTSUPP;
2769 }
2770 EXPORT_SYMBOL(sock_no_accept);
2771 
2772 int sock_no_getname(struct socket *sock, struct sockaddr *saddr,
2773 		    int peer)
2774 {
2775 	return -EOPNOTSUPP;
2776 }
2777 EXPORT_SYMBOL(sock_no_getname);
2778 
2779 int sock_no_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
2780 {
2781 	return -EOPNOTSUPP;
2782 }
2783 EXPORT_SYMBOL(sock_no_ioctl);
2784 
2785 int sock_no_listen(struct socket *sock, int backlog)
2786 {
2787 	return -EOPNOTSUPP;
2788 }
2789 EXPORT_SYMBOL(sock_no_listen);
2790 
2791 int sock_no_shutdown(struct socket *sock, int how)
2792 {
2793 	return -EOPNOTSUPP;
2794 }
2795 EXPORT_SYMBOL(sock_no_shutdown);
2796 
2797 int sock_no_sendmsg(struct socket *sock, struct msghdr *m, size_t len)
2798 {
2799 	return -EOPNOTSUPP;
2800 }
2801 EXPORT_SYMBOL(sock_no_sendmsg);
2802 
2803 int sock_no_sendmsg_locked(struct sock *sk, struct msghdr *m, size_t len)
2804 {
2805 	return -EOPNOTSUPP;
2806 }
2807 EXPORT_SYMBOL(sock_no_sendmsg_locked);
2808 
2809 int sock_no_recvmsg(struct socket *sock, struct msghdr *m, size_t len,
2810 		    int flags)
2811 {
2812 	return -EOPNOTSUPP;
2813 }
2814 EXPORT_SYMBOL(sock_no_recvmsg);
2815 
2816 int sock_no_mmap(struct file *file, struct socket *sock, struct vm_area_struct *vma)
2817 {
2818 	/* Mirror missing mmap method error code */
2819 	return -ENODEV;
2820 }
2821 EXPORT_SYMBOL(sock_no_mmap);
2822 
2823 /*
2824  * When a file is received (via SCM_RIGHTS, etc), we must bump the
2825  * various sock-based usage counts.
2826  */
2827 void __receive_sock(struct file *file)
2828 {
2829 	struct socket *sock;
2830 	int error;
2831 
2832 	/*
2833 	 * The resulting value of "error" is ignored here since we only
2834 	 * need to take action when the file is a socket and testing
2835 	 * "sock" for NULL is sufficient.
2836 	 */
2837 	sock = sock_from_file(file, &error);
2838 	if (sock) {
2839 		sock_update_netprioidx(&sock->sk->sk_cgrp_data);
2840 		sock_update_classid(&sock->sk->sk_cgrp_data);
2841 	}
2842 }
2843 
2844 ssize_t sock_no_sendpage(struct socket *sock, struct page *page, int offset, size_t size, int flags)
2845 {
2846 	ssize_t res;
2847 	struct msghdr msg = {.msg_flags = flags};
2848 	struct kvec iov;
2849 	char *kaddr = kmap(page);
2850 	iov.iov_base = kaddr + offset;
2851 	iov.iov_len = size;
2852 	res = kernel_sendmsg(sock, &msg, &iov, 1, size);
2853 	kunmap(page);
2854 	return res;
2855 }
2856 EXPORT_SYMBOL(sock_no_sendpage);
2857 
2858 ssize_t sock_no_sendpage_locked(struct sock *sk, struct page *page,
2859 				int offset, size_t size, int flags)
2860 {
2861 	ssize_t res;
2862 	struct msghdr msg = {.msg_flags = flags};
2863 	struct kvec iov;
2864 	char *kaddr = kmap(page);
2865 
2866 	iov.iov_base = kaddr + offset;
2867 	iov.iov_len = size;
2868 	res = kernel_sendmsg_locked(sk, &msg, &iov, 1, size);
2869 	kunmap(page);
2870 	return res;
2871 }
2872 EXPORT_SYMBOL(sock_no_sendpage_locked);
2873 
2874 /*
2875  *	Default Socket Callbacks
2876  */
2877 
2878 static void sock_def_wakeup(struct sock *sk)
2879 {
2880 	struct socket_wq *wq;
2881 
2882 	rcu_read_lock();
2883 	wq = rcu_dereference(sk->sk_wq);
2884 	if (skwq_has_sleeper(wq))
2885 		wake_up_interruptible_all(&wq->wait);
2886 	rcu_read_unlock();
2887 }
2888 
2889 static void sock_def_error_report(struct sock *sk)
2890 {
2891 	struct socket_wq *wq;
2892 
2893 	rcu_read_lock();
2894 	wq = rcu_dereference(sk->sk_wq);
2895 	if (skwq_has_sleeper(wq))
2896 		wake_up_interruptible_poll(&wq->wait, EPOLLERR);
2897 	sk_wake_async(sk, SOCK_WAKE_IO, POLL_ERR);
2898 	rcu_read_unlock();
2899 }
2900 
2901 void sock_def_readable(struct sock *sk)
2902 {
2903 	struct socket_wq *wq;
2904 
2905 	rcu_read_lock();
2906 	wq = rcu_dereference(sk->sk_wq);
2907 	if (skwq_has_sleeper(wq))
2908 		wake_up_interruptible_sync_poll(&wq->wait, EPOLLIN | EPOLLPRI |
2909 						EPOLLRDNORM | EPOLLRDBAND);
2910 	sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
2911 	rcu_read_unlock();
2912 }
2913 
2914 static void sock_def_write_space(struct sock *sk)
2915 {
2916 	struct socket_wq *wq;
2917 
2918 	rcu_read_lock();
2919 
2920 	/* Do not wake up a writer until he can make "significant"
2921 	 * progress.  --DaveM
2922 	 */
2923 	if ((refcount_read(&sk->sk_wmem_alloc) << 1) <= READ_ONCE(sk->sk_sndbuf)) {
2924 		wq = rcu_dereference(sk->sk_wq);
2925 		if (skwq_has_sleeper(wq))
2926 			wake_up_interruptible_sync_poll(&wq->wait, EPOLLOUT |
2927 						EPOLLWRNORM | EPOLLWRBAND);
2928 
2929 		/* Should agree with poll, otherwise some programs break */
2930 		if (sock_writeable(sk))
2931 			sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
2932 	}
2933 
2934 	rcu_read_unlock();
2935 }
2936 
2937 static void sock_def_destruct(struct sock *sk)
2938 {
2939 }
2940 
2941 void sk_send_sigurg(struct sock *sk)
2942 {
2943 	if (sk->sk_socket && sk->sk_socket->file)
2944 		if (send_sigurg(&sk->sk_socket->file->f_owner))
2945 			sk_wake_async(sk, SOCK_WAKE_URG, POLL_PRI);
2946 }
2947 EXPORT_SYMBOL(sk_send_sigurg);
2948 
2949 void sk_reset_timer(struct sock *sk, struct timer_list* timer,
2950 		    unsigned long expires)
2951 {
2952 	if (!mod_timer(timer, expires))
2953 		sock_hold(sk);
2954 }
2955 EXPORT_SYMBOL(sk_reset_timer);
2956 
2957 void sk_stop_timer(struct sock *sk, struct timer_list* timer)
2958 {
2959 	if (del_timer(timer))
2960 		__sock_put(sk);
2961 }
2962 EXPORT_SYMBOL(sk_stop_timer);
2963 
2964 void sock_init_data(struct socket *sock, struct sock *sk)
2965 {
2966 	sk_init_common(sk);
2967 	sk->sk_send_head	=	NULL;
2968 
2969 	timer_setup(&sk->sk_timer, NULL, 0);
2970 
2971 	sk->sk_allocation	=	GFP_KERNEL;
2972 	sk->sk_rcvbuf		=	sysctl_rmem_default;
2973 	sk->sk_sndbuf		=	sysctl_wmem_default;
2974 	sk->sk_state		=	TCP_CLOSE;
2975 	sk_set_socket(sk, sock);
2976 
2977 	sock_set_flag(sk, SOCK_ZAPPED);
2978 
2979 	if (sock) {
2980 		sk->sk_type	=	sock->type;
2981 		RCU_INIT_POINTER(sk->sk_wq, &sock->wq);
2982 		sock->sk	=	sk;
2983 		sk->sk_uid	=	SOCK_INODE(sock)->i_uid;
2984 	} else {
2985 		RCU_INIT_POINTER(sk->sk_wq, NULL);
2986 		sk->sk_uid	=	make_kuid(sock_net(sk)->user_ns, 0);
2987 	}
2988 
2989 	rwlock_init(&sk->sk_callback_lock);
2990 	if (sk->sk_kern_sock)
2991 		lockdep_set_class_and_name(
2992 			&sk->sk_callback_lock,
2993 			af_kern_callback_keys + sk->sk_family,
2994 			af_family_kern_clock_key_strings[sk->sk_family]);
2995 	else
2996 		lockdep_set_class_and_name(
2997 			&sk->sk_callback_lock,
2998 			af_callback_keys + sk->sk_family,
2999 			af_family_clock_key_strings[sk->sk_family]);
3000 
3001 	sk->sk_state_change	=	sock_def_wakeup;
3002 	sk->sk_data_ready	=	sock_def_readable;
3003 	sk->sk_write_space	=	sock_def_write_space;
3004 	sk->sk_error_report	=	sock_def_error_report;
3005 	sk->sk_destruct		=	sock_def_destruct;
3006 
3007 	sk->sk_frag.page	=	NULL;
3008 	sk->sk_frag.offset	=	0;
3009 	sk->sk_peek_off		=	-1;
3010 
3011 	sk->sk_peer_pid 	=	NULL;
3012 	sk->sk_peer_cred	=	NULL;
3013 	sk->sk_write_pending	=	0;
3014 	sk->sk_rcvlowat		=	1;
3015 	sk->sk_rcvtimeo		=	MAX_SCHEDULE_TIMEOUT;
3016 	sk->sk_sndtimeo		=	MAX_SCHEDULE_TIMEOUT;
3017 
3018 	sk->sk_stamp = SK_DEFAULT_STAMP;
3019 #if BITS_PER_LONG==32
3020 	seqlock_init(&sk->sk_stamp_seq);
3021 #endif
3022 	atomic_set(&sk->sk_zckey, 0);
3023 
3024 #ifdef CONFIG_NET_RX_BUSY_POLL
3025 	sk->sk_napi_id		=	0;
3026 	sk->sk_ll_usec		=	sysctl_net_busy_read;
3027 #endif
3028 
3029 	sk->sk_max_pacing_rate = ~0UL;
3030 	sk->sk_pacing_rate = ~0UL;
3031 	WRITE_ONCE(sk->sk_pacing_shift, 10);
3032 	sk->sk_incoming_cpu = -1;
3033 
3034 	sk_rx_queue_clear(sk);
3035 	/*
3036 	 * Before updating sk_refcnt, we must commit prior changes to memory
3037 	 * (Documentation/RCU/rculist_nulls.rst for details)
3038 	 */
3039 	smp_wmb();
3040 	refcount_set(&sk->sk_refcnt, 1);
3041 	atomic_set(&sk->sk_drops, 0);
3042 }
3043 EXPORT_SYMBOL(sock_init_data);
3044 
3045 void lock_sock_nested(struct sock *sk, int subclass)
3046 {
3047 	might_sleep();
3048 	spin_lock_bh(&sk->sk_lock.slock);
3049 	if (sk->sk_lock.owned)
3050 		__lock_sock(sk);
3051 	sk->sk_lock.owned = 1;
3052 	spin_unlock(&sk->sk_lock.slock);
3053 	/*
3054 	 * The sk_lock has mutex_lock() semantics here:
3055 	 */
3056 	mutex_acquire(&sk->sk_lock.dep_map, subclass, 0, _RET_IP_);
3057 	local_bh_enable();
3058 }
3059 EXPORT_SYMBOL(lock_sock_nested);
3060 
3061 void release_sock(struct sock *sk)
3062 {
3063 	spin_lock_bh(&sk->sk_lock.slock);
3064 	if (sk->sk_backlog.tail)
3065 		__release_sock(sk);
3066 
3067 	/* Warning : release_cb() might need to release sk ownership,
3068 	 * ie call sock_release_ownership(sk) before us.
3069 	 */
3070 	if (sk->sk_prot->release_cb)
3071 		sk->sk_prot->release_cb(sk);
3072 
3073 	sock_release_ownership(sk);
3074 	if (waitqueue_active(&sk->sk_lock.wq))
3075 		wake_up(&sk->sk_lock.wq);
3076 	spin_unlock_bh(&sk->sk_lock.slock);
3077 }
3078 EXPORT_SYMBOL(release_sock);
3079 
3080 /**
3081  * lock_sock_fast - fast version of lock_sock
3082  * @sk: socket
3083  *
3084  * This version should be used for very small section, where process wont block
3085  * return false if fast path is taken:
3086  *
3087  *   sk_lock.slock locked, owned = 0, BH disabled
3088  *
3089  * return true if slow path is taken:
3090  *
3091  *   sk_lock.slock unlocked, owned = 1, BH enabled
3092  */
3093 bool lock_sock_fast(struct sock *sk)
3094 {
3095 	might_sleep();
3096 	spin_lock_bh(&sk->sk_lock.slock);
3097 
3098 	if (!sk->sk_lock.owned)
3099 		/*
3100 		 * Note : We must disable BH
3101 		 */
3102 		return false;
3103 
3104 	__lock_sock(sk);
3105 	sk->sk_lock.owned = 1;
3106 	spin_unlock(&sk->sk_lock.slock);
3107 	/*
3108 	 * The sk_lock has mutex_lock() semantics here:
3109 	 */
3110 	mutex_acquire(&sk->sk_lock.dep_map, 0, 0, _RET_IP_);
3111 	local_bh_enable();
3112 	return true;
3113 }
3114 EXPORT_SYMBOL(lock_sock_fast);
3115 
3116 int sock_gettstamp(struct socket *sock, void __user *userstamp,
3117 		   bool timeval, bool time32)
3118 {
3119 	struct sock *sk = sock->sk;
3120 	struct timespec64 ts;
3121 
3122 	sock_enable_timestamp(sk, SOCK_TIMESTAMP);
3123 	ts = ktime_to_timespec64(sock_read_timestamp(sk));
3124 	if (ts.tv_sec == -1)
3125 		return -ENOENT;
3126 	if (ts.tv_sec == 0) {
3127 		ktime_t kt = ktime_get_real();
3128 		sock_write_timestamp(sk, kt);
3129 		ts = ktime_to_timespec64(kt);
3130 	}
3131 
3132 	if (timeval)
3133 		ts.tv_nsec /= 1000;
3134 
3135 #ifdef CONFIG_COMPAT_32BIT_TIME
3136 	if (time32)
3137 		return put_old_timespec32(&ts, userstamp);
3138 #endif
3139 #ifdef CONFIG_SPARC64
3140 	/* beware of padding in sparc64 timeval */
3141 	if (timeval && !in_compat_syscall()) {
3142 		struct __kernel_old_timeval __user tv = {
3143 			.tv_sec = ts.tv_sec,
3144 			.tv_usec = ts.tv_nsec,
3145 		};
3146 		if (copy_to_user(userstamp, &tv, sizeof(tv)))
3147 			return -EFAULT;
3148 		return 0;
3149 	}
3150 #endif
3151 	return put_timespec64(&ts, userstamp);
3152 }
3153 EXPORT_SYMBOL(sock_gettstamp);
3154 
3155 void sock_enable_timestamp(struct sock *sk, enum sock_flags flag)
3156 {
3157 	if (!sock_flag(sk, flag)) {
3158 		unsigned long previous_flags = sk->sk_flags;
3159 
3160 		sock_set_flag(sk, flag);
3161 		/*
3162 		 * we just set one of the two flags which require net
3163 		 * time stamping, but time stamping might have been on
3164 		 * already because of the other one
3165 		 */
3166 		if (sock_needs_netstamp(sk) &&
3167 		    !(previous_flags & SK_FLAGS_TIMESTAMP))
3168 			net_enable_timestamp();
3169 	}
3170 }
3171 
3172 int sock_recv_errqueue(struct sock *sk, struct msghdr *msg, int len,
3173 		       int level, int type)
3174 {
3175 	struct sock_exterr_skb *serr;
3176 	struct sk_buff *skb;
3177 	int copied, err;
3178 
3179 	err = -EAGAIN;
3180 	skb = sock_dequeue_err_skb(sk);
3181 	if (skb == NULL)
3182 		goto out;
3183 
3184 	copied = skb->len;
3185 	if (copied > len) {
3186 		msg->msg_flags |= MSG_TRUNC;
3187 		copied = len;
3188 	}
3189 	err = skb_copy_datagram_msg(skb, 0, msg, copied);
3190 	if (err)
3191 		goto out_free_skb;
3192 
3193 	sock_recv_timestamp(msg, sk, skb);
3194 
3195 	serr = SKB_EXT_ERR(skb);
3196 	put_cmsg(msg, level, type, sizeof(serr->ee), &serr->ee);
3197 
3198 	msg->msg_flags |= MSG_ERRQUEUE;
3199 	err = copied;
3200 
3201 out_free_skb:
3202 	kfree_skb(skb);
3203 out:
3204 	return err;
3205 }
3206 EXPORT_SYMBOL(sock_recv_errqueue);
3207 
3208 /*
3209  *	Get a socket option on an socket.
3210  *
3211  *	FIX: POSIX 1003.1g is very ambiguous here. It states that
3212  *	asynchronous errors should be reported by getsockopt. We assume
3213  *	this means if you specify SO_ERROR (otherwise whats the point of it).
3214  */
3215 int sock_common_getsockopt(struct socket *sock, int level, int optname,
3216 			   char __user *optval, int __user *optlen)
3217 {
3218 	struct sock *sk = sock->sk;
3219 
3220 	return sk->sk_prot->getsockopt(sk, level, optname, optval, optlen);
3221 }
3222 EXPORT_SYMBOL(sock_common_getsockopt);
3223 
3224 int sock_common_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
3225 			int flags)
3226 {
3227 	struct sock *sk = sock->sk;
3228 	int addr_len = 0;
3229 	int err;
3230 
3231 	err = sk->sk_prot->recvmsg(sk, msg, size, flags & MSG_DONTWAIT,
3232 				   flags & ~MSG_DONTWAIT, &addr_len);
3233 	if (err >= 0)
3234 		msg->msg_namelen = addr_len;
3235 	return err;
3236 }
3237 EXPORT_SYMBOL(sock_common_recvmsg);
3238 
3239 /*
3240  *	Set socket options on an inet socket.
3241  */
3242 int sock_common_setsockopt(struct socket *sock, int level, int optname,
3243 			   sockptr_t optval, unsigned int optlen)
3244 {
3245 	struct sock *sk = sock->sk;
3246 
3247 	return sk->sk_prot->setsockopt(sk, level, optname, optval, optlen);
3248 }
3249 EXPORT_SYMBOL(sock_common_setsockopt);
3250 
3251 void sk_common_release(struct sock *sk)
3252 {
3253 	if (sk->sk_prot->destroy)
3254 		sk->sk_prot->destroy(sk);
3255 
3256 	/*
3257 	 * Observation: when sock_common_release is called, processes have
3258 	 * no access to socket. But net still has.
3259 	 * Step one, detach it from networking:
3260 	 *
3261 	 * A. Remove from hash tables.
3262 	 */
3263 
3264 	sk->sk_prot->unhash(sk);
3265 
3266 	/*
3267 	 * In this point socket cannot receive new packets, but it is possible
3268 	 * that some packets are in flight because some CPU runs receiver and
3269 	 * did hash table lookup before we unhashed socket. They will achieve
3270 	 * receive queue and will be purged by socket destructor.
3271 	 *
3272 	 * Also we still have packets pending on receive queue and probably,
3273 	 * our own packets waiting in device queues. sock_destroy will drain
3274 	 * receive queue, but transmitted packets will delay socket destruction
3275 	 * until the last reference will be released.
3276 	 */
3277 
3278 	sock_orphan(sk);
3279 
3280 	xfrm_sk_free_policy(sk);
3281 
3282 	sk_refcnt_debug_release(sk);
3283 
3284 	sock_put(sk);
3285 }
3286 EXPORT_SYMBOL(sk_common_release);
3287 
3288 void sk_get_meminfo(const struct sock *sk, u32 *mem)
3289 {
3290 	memset(mem, 0, sizeof(*mem) * SK_MEMINFO_VARS);
3291 
3292 	mem[SK_MEMINFO_RMEM_ALLOC] = sk_rmem_alloc_get(sk);
3293 	mem[SK_MEMINFO_RCVBUF] = READ_ONCE(sk->sk_rcvbuf);
3294 	mem[SK_MEMINFO_WMEM_ALLOC] = sk_wmem_alloc_get(sk);
3295 	mem[SK_MEMINFO_SNDBUF] = READ_ONCE(sk->sk_sndbuf);
3296 	mem[SK_MEMINFO_FWD_ALLOC] = sk->sk_forward_alloc;
3297 	mem[SK_MEMINFO_WMEM_QUEUED] = READ_ONCE(sk->sk_wmem_queued);
3298 	mem[SK_MEMINFO_OPTMEM] = atomic_read(&sk->sk_omem_alloc);
3299 	mem[SK_MEMINFO_BACKLOG] = READ_ONCE(sk->sk_backlog.len);
3300 	mem[SK_MEMINFO_DROPS] = atomic_read(&sk->sk_drops);
3301 }
3302 
3303 #ifdef CONFIG_PROC_FS
3304 #define PROTO_INUSE_NR	64	/* should be enough for the first time */
3305 struct prot_inuse {
3306 	int val[PROTO_INUSE_NR];
3307 };
3308 
3309 static DECLARE_BITMAP(proto_inuse_idx, PROTO_INUSE_NR);
3310 
3311 void sock_prot_inuse_add(struct net *net, struct proto *prot, int val)
3312 {
3313 	__this_cpu_add(net->core.prot_inuse->val[prot->inuse_idx], val);
3314 }
3315 EXPORT_SYMBOL_GPL(sock_prot_inuse_add);
3316 
3317 int sock_prot_inuse_get(struct net *net, struct proto *prot)
3318 {
3319 	int cpu, idx = prot->inuse_idx;
3320 	int res = 0;
3321 
3322 	for_each_possible_cpu(cpu)
3323 		res += per_cpu_ptr(net->core.prot_inuse, cpu)->val[idx];
3324 
3325 	return res >= 0 ? res : 0;
3326 }
3327 EXPORT_SYMBOL_GPL(sock_prot_inuse_get);
3328 
3329 static void sock_inuse_add(struct net *net, int val)
3330 {
3331 	this_cpu_add(*net->core.sock_inuse, val);
3332 }
3333 
3334 int sock_inuse_get(struct net *net)
3335 {
3336 	int cpu, res = 0;
3337 
3338 	for_each_possible_cpu(cpu)
3339 		res += *per_cpu_ptr(net->core.sock_inuse, cpu);
3340 
3341 	return res;
3342 }
3343 
3344 EXPORT_SYMBOL_GPL(sock_inuse_get);
3345 
3346 static int __net_init sock_inuse_init_net(struct net *net)
3347 {
3348 	net->core.prot_inuse = alloc_percpu(struct prot_inuse);
3349 	if (net->core.prot_inuse == NULL)
3350 		return -ENOMEM;
3351 
3352 	net->core.sock_inuse = alloc_percpu(int);
3353 	if (net->core.sock_inuse == NULL)
3354 		goto out;
3355 
3356 	return 0;
3357 
3358 out:
3359 	free_percpu(net->core.prot_inuse);
3360 	return -ENOMEM;
3361 }
3362 
3363 static void __net_exit sock_inuse_exit_net(struct net *net)
3364 {
3365 	free_percpu(net->core.prot_inuse);
3366 	free_percpu(net->core.sock_inuse);
3367 }
3368 
3369 static struct pernet_operations net_inuse_ops = {
3370 	.init = sock_inuse_init_net,
3371 	.exit = sock_inuse_exit_net,
3372 };
3373 
3374 static __init int net_inuse_init(void)
3375 {
3376 	if (register_pernet_subsys(&net_inuse_ops))
3377 		panic("Cannot initialize net inuse counters");
3378 
3379 	return 0;
3380 }
3381 
3382 core_initcall(net_inuse_init);
3383 
3384 static int assign_proto_idx(struct proto *prot)
3385 {
3386 	prot->inuse_idx = find_first_zero_bit(proto_inuse_idx, PROTO_INUSE_NR);
3387 
3388 	if (unlikely(prot->inuse_idx == PROTO_INUSE_NR - 1)) {
3389 		pr_err("PROTO_INUSE_NR exhausted\n");
3390 		return -ENOSPC;
3391 	}
3392 
3393 	set_bit(prot->inuse_idx, proto_inuse_idx);
3394 	return 0;
3395 }
3396 
3397 static void release_proto_idx(struct proto *prot)
3398 {
3399 	if (prot->inuse_idx != PROTO_INUSE_NR - 1)
3400 		clear_bit(prot->inuse_idx, proto_inuse_idx);
3401 }
3402 #else
3403 static inline int assign_proto_idx(struct proto *prot)
3404 {
3405 	return 0;
3406 }
3407 
3408 static inline void release_proto_idx(struct proto *prot)
3409 {
3410 }
3411 
3412 static void sock_inuse_add(struct net *net, int val)
3413 {
3414 }
3415 #endif
3416 
3417 static void tw_prot_cleanup(struct timewait_sock_ops *twsk_prot)
3418 {
3419 	if (!twsk_prot)
3420 		return;
3421 	kfree(twsk_prot->twsk_slab_name);
3422 	twsk_prot->twsk_slab_name = NULL;
3423 	kmem_cache_destroy(twsk_prot->twsk_slab);
3424 	twsk_prot->twsk_slab = NULL;
3425 }
3426 
3427 static void req_prot_cleanup(struct request_sock_ops *rsk_prot)
3428 {
3429 	if (!rsk_prot)
3430 		return;
3431 	kfree(rsk_prot->slab_name);
3432 	rsk_prot->slab_name = NULL;
3433 	kmem_cache_destroy(rsk_prot->slab);
3434 	rsk_prot->slab = NULL;
3435 }
3436 
3437 static int req_prot_init(const struct proto *prot)
3438 {
3439 	struct request_sock_ops *rsk_prot = prot->rsk_prot;
3440 
3441 	if (!rsk_prot)
3442 		return 0;
3443 
3444 	rsk_prot->slab_name = kasprintf(GFP_KERNEL, "request_sock_%s",
3445 					prot->name);
3446 	if (!rsk_prot->slab_name)
3447 		return -ENOMEM;
3448 
3449 	rsk_prot->slab = kmem_cache_create(rsk_prot->slab_name,
3450 					   rsk_prot->obj_size, 0,
3451 					   SLAB_ACCOUNT | prot->slab_flags,
3452 					   NULL);
3453 
3454 	if (!rsk_prot->slab) {
3455 		pr_crit("%s: Can't create request sock SLAB cache!\n",
3456 			prot->name);
3457 		return -ENOMEM;
3458 	}
3459 	return 0;
3460 }
3461 
3462 int proto_register(struct proto *prot, int alloc_slab)
3463 {
3464 	int ret = -ENOBUFS;
3465 
3466 	if (alloc_slab) {
3467 		prot->slab = kmem_cache_create_usercopy(prot->name,
3468 					prot->obj_size, 0,
3469 					SLAB_HWCACHE_ALIGN | SLAB_ACCOUNT |
3470 					prot->slab_flags,
3471 					prot->useroffset, prot->usersize,
3472 					NULL);
3473 
3474 		if (prot->slab == NULL) {
3475 			pr_crit("%s: Can't create sock SLAB cache!\n",
3476 				prot->name);
3477 			goto out;
3478 		}
3479 
3480 		if (req_prot_init(prot))
3481 			goto out_free_request_sock_slab;
3482 
3483 		if (prot->twsk_prot != NULL) {
3484 			prot->twsk_prot->twsk_slab_name = kasprintf(GFP_KERNEL, "tw_sock_%s", prot->name);
3485 
3486 			if (prot->twsk_prot->twsk_slab_name == NULL)
3487 				goto out_free_request_sock_slab;
3488 
3489 			prot->twsk_prot->twsk_slab =
3490 				kmem_cache_create(prot->twsk_prot->twsk_slab_name,
3491 						  prot->twsk_prot->twsk_obj_size,
3492 						  0,
3493 						  SLAB_ACCOUNT |
3494 						  prot->slab_flags,
3495 						  NULL);
3496 			if (prot->twsk_prot->twsk_slab == NULL)
3497 				goto out_free_timewait_sock_slab;
3498 		}
3499 	}
3500 
3501 	mutex_lock(&proto_list_mutex);
3502 	ret = assign_proto_idx(prot);
3503 	if (ret) {
3504 		mutex_unlock(&proto_list_mutex);
3505 		goto out_free_timewait_sock_slab;
3506 	}
3507 	list_add(&prot->node, &proto_list);
3508 	mutex_unlock(&proto_list_mutex);
3509 	return ret;
3510 
3511 out_free_timewait_sock_slab:
3512 	if (alloc_slab && prot->twsk_prot)
3513 		tw_prot_cleanup(prot->twsk_prot);
3514 out_free_request_sock_slab:
3515 	if (alloc_slab) {
3516 		req_prot_cleanup(prot->rsk_prot);
3517 
3518 		kmem_cache_destroy(prot->slab);
3519 		prot->slab = NULL;
3520 	}
3521 out:
3522 	return ret;
3523 }
3524 EXPORT_SYMBOL(proto_register);
3525 
3526 void proto_unregister(struct proto *prot)
3527 {
3528 	mutex_lock(&proto_list_mutex);
3529 	release_proto_idx(prot);
3530 	list_del(&prot->node);
3531 	mutex_unlock(&proto_list_mutex);
3532 
3533 	kmem_cache_destroy(prot->slab);
3534 	prot->slab = NULL;
3535 
3536 	req_prot_cleanup(prot->rsk_prot);
3537 	tw_prot_cleanup(prot->twsk_prot);
3538 }
3539 EXPORT_SYMBOL(proto_unregister);
3540 
3541 int sock_load_diag_module(int family, int protocol)
3542 {
3543 	if (!protocol) {
3544 		if (!sock_is_registered(family))
3545 			return -ENOENT;
3546 
3547 		return request_module("net-pf-%d-proto-%d-type-%d", PF_NETLINK,
3548 				      NETLINK_SOCK_DIAG, family);
3549 	}
3550 
3551 #ifdef CONFIG_INET
3552 	if (family == AF_INET &&
3553 	    protocol != IPPROTO_RAW &&
3554 	    protocol < MAX_INET_PROTOS &&
3555 	    !rcu_access_pointer(inet_protos[protocol]))
3556 		return -ENOENT;
3557 #endif
3558 
3559 	return request_module("net-pf-%d-proto-%d-type-%d-%d", PF_NETLINK,
3560 			      NETLINK_SOCK_DIAG, family, protocol);
3561 }
3562 EXPORT_SYMBOL(sock_load_diag_module);
3563 
3564 #ifdef CONFIG_PROC_FS
3565 static void *proto_seq_start(struct seq_file *seq, loff_t *pos)
3566 	__acquires(proto_list_mutex)
3567 {
3568 	mutex_lock(&proto_list_mutex);
3569 	return seq_list_start_head(&proto_list, *pos);
3570 }
3571 
3572 static void *proto_seq_next(struct seq_file *seq, void *v, loff_t *pos)
3573 {
3574 	return seq_list_next(v, &proto_list, pos);
3575 }
3576 
3577 static void proto_seq_stop(struct seq_file *seq, void *v)
3578 	__releases(proto_list_mutex)
3579 {
3580 	mutex_unlock(&proto_list_mutex);
3581 }
3582 
3583 static char proto_method_implemented(const void *method)
3584 {
3585 	return method == NULL ? 'n' : 'y';
3586 }
3587 static long sock_prot_memory_allocated(struct proto *proto)
3588 {
3589 	return proto->memory_allocated != NULL ? proto_memory_allocated(proto) : -1L;
3590 }
3591 
3592 static const char *sock_prot_memory_pressure(struct proto *proto)
3593 {
3594 	return proto->memory_pressure != NULL ?
3595 	proto_memory_pressure(proto) ? "yes" : "no" : "NI";
3596 }
3597 
3598 static void proto_seq_printf(struct seq_file *seq, struct proto *proto)
3599 {
3600 
3601 	seq_printf(seq, "%-9s %4u %6d  %6ld   %-3s %6u   %-3s  %-10s "
3602 			"%2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c\n",
3603 		   proto->name,
3604 		   proto->obj_size,
3605 		   sock_prot_inuse_get(seq_file_net(seq), proto),
3606 		   sock_prot_memory_allocated(proto),
3607 		   sock_prot_memory_pressure(proto),
3608 		   proto->max_header,
3609 		   proto->slab == NULL ? "no" : "yes",
3610 		   module_name(proto->owner),
3611 		   proto_method_implemented(proto->close),
3612 		   proto_method_implemented(proto->connect),
3613 		   proto_method_implemented(proto->disconnect),
3614 		   proto_method_implemented(proto->accept),
3615 		   proto_method_implemented(proto->ioctl),
3616 		   proto_method_implemented(proto->init),
3617 		   proto_method_implemented(proto->destroy),
3618 		   proto_method_implemented(proto->shutdown),
3619 		   proto_method_implemented(proto->setsockopt),
3620 		   proto_method_implemented(proto->getsockopt),
3621 		   proto_method_implemented(proto->sendmsg),
3622 		   proto_method_implemented(proto->recvmsg),
3623 		   proto_method_implemented(proto->sendpage),
3624 		   proto_method_implemented(proto->bind),
3625 		   proto_method_implemented(proto->backlog_rcv),
3626 		   proto_method_implemented(proto->hash),
3627 		   proto_method_implemented(proto->unhash),
3628 		   proto_method_implemented(proto->get_port),
3629 		   proto_method_implemented(proto->enter_memory_pressure));
3630 }
3631 
3632 static int proto_seq_show(struct seq_file *seq, void *v)
3633 {
3634 	if (v == &proto_list)
3635 		seq_printf(seq, "%-9s %-4s %-8s %-6s %-5s %-7s %-4s %-10s %s",
3636 			   "protocol",
3637 			   "size",
3638 			   "sockets",
3639 			   "memory",
3640 			   "press",
3641 			   "maxhdr",
3642 			   "slab",
3643 			   "module",
3644 			   "cl co di ac io in de sh ss gs se re sp bi br ha uh gp em\n");
3645 	else
3646 		proto_seq_printf(seq, list_entry(v, struct proto, node));
3647 	return 0;
3648 }
3649 
3650 static const struct seq_operations proto_seq_ops = {
3651 	.start  = proto_seq_start,
3652 	.next   = proto_seq_next,
3653 	.stop   = proto_seq_stop,
3654 	.show   = proto_seq_show,
3655 };
3656 
3657 static __net_init int proto_init_net(struct net *net)
3658 {
3659 	if (!proc_create_net("protocols", 0444, net->proc_net, &proto_seq_ops,
3660 			sizeof(struct seq_net_private)))
3661 		return -ENOMEM;
3662 
3663 	return 0;
3664 }
3665 
3666 static __net_exit void proto_exit_net(struct net *net)
3667 {
3668 	remove_proc_entry("protocols", net->proc_net);
3669 }
3670 
3671 
3672 static __net_initdata struct pernet_operations proto_net_ops = {
3673 	.init = proto_init_net,
3674 	.exit = proto_exit_net,
3675 };
3676 
3677 static int __init proto_init(void)
3678 {
3679 	return register_pernet_subsys(&proto_net_ops);
3680 }
3681 
3682 subsys_initcall(proto_init);
3683 
3684 #endif /* PROC_FS */
3685 
3686 #ifdef CONFIG_NET_RX_BUSY_POLL
3687 bool sk_busy_loop_end(void *p, unsigned long start_time)
3688 {
3689 	struct sock *sk = p;
3690 
3691 	return !skb_queue_empty_lockless(&sk->sk_receive_queue) ||
3692 	       sk_busy_loop_timeout(sk, start_time);
3693 }
3694 EXPORT_SYMBOL(sk_busy_loop_end);
3695 #endif /* CONFIG_NET_RX_BUSY_POLL */
3696 
3697 int sock_bind_add(struct sock *sk, struct sockaddr *addr, int addr_len)
3698 {
3699 	if (!sk->sk_prot->bind_add)
3700 		return -EOPNOTSUPP;
3701 	return sk->sk_prot->bind_add(sk, addr, addr_len);
3702 }
3703 EXPORT_SYMBOL(sock_bind_add);
3704