xref: /linux/net/core/sock.c (revision 2993c9b04e616df0848b655d7202a707a70fc876)
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 
117 #include <linux/uaccess.h>
118 
119 #include <linux/netdevice.h>
120 #include <net/protocol.h>
121 #include <linux/skbuff.h>
122 #include <net/net_namespace.h>
123 #include <net/request_sock.h>
124 #include <net/sock.h>
125 #include <linux/net_tstamp.h>
126 #include <net/xfrm.h>
127 #include <linux/ipsec.h>
128 #include <net/cls_cgroup.h>
129 #include <net/netprio_cgroup.h>
130 #include <linux/sock_diag.h>
131 
132 #include <linux/filter.h>
133 #include <net/sock_reuseport.h>
134 #include <net/bpf_sk_storage.h>
135 
136 #include <trace/events/sock.h>
137 
138 #include <net/tcp.h>
139 #include <net/busy_poll.h>
140 
141 static DEFINE_MUTEX(proto_list_mutex);
142 static LIST_HEAD(proto_list);
143 
144 static void sock_inuse_add(struct net *net, int val);
145 
146 /**
147  * sk_ns_capable - General socket capability test
148  * @sk: Socket to use a capability on or through
149  * @user_ns: The user namespace of the capability to use
150  * @cap: The capability to use
151  *
152  * Test to see if the opener of the socket had when the socket was
153  * created and the current process has the capability @cap in the user
154  * namespace @user_ns.
155  */
156 bool sk_ns_capable(const struct sock *sk,
157 		   struct user_namespace *user_ns, int cap)
158 {
159 	return file_ns_capable(sk->sk_socket->file, user_ns, cap) &&
160 		ns_capable(user_ns, cap);
161 }
162 EXPORT_SYMBOL(sk_ns_capable);
163 
164 /**
165  * sk_capable - Socket global capability test
166  * @sk: Socket to use a capability on or through
167  * @cap: The global capability to use
168  *
169  * Test to see if the opener of the socket had when the socket was
170  * created and the current process has the capability @cap in all user
171  * namespaces.
172  */
173 bool sk_capable(const struct sock *sk, int cap)
174 {
175 	return sk_ns_capable(sk, &init_user_ns, cap);
176 }
177 EXPORT_SYMBOL(sk_capable);
178 
179 /**
180  * sk_net_capable - Network namespace socket capability test
181  * @sk: Socket to use a capability on or through
182  * @cap: The capability to use
183  *
184  * Test to see if the opener of the socket had when the socket was created
185  * and the current process has the capability @cap over the network namespace
186  * the socket is a member of.
187  */
188 bool sk_net_capable(const struct sock *sk, int cap)
189 {
190 	return sk_ns_capable(sk, sock_net(sk)->user_ns, cap);
191 }
192 EXPORT_SYMBOL(sk_net_capable);
193 
194 /*
195  * Each address family might have different locking rules, so we have
196  * one slock key per address family and separate keys for internal and
197  * userspace sockets.
198  */
199 static struct lock_class_key af_family_keys[AF_MAX];
200 static struct lock_class_key af_family_kern_keys[AF_MAX];
201 static struct lock_class_key af_family_slock_keys[AF_MAX];
202 static struct lock_class_key af_family_kern_slock_keys[AF_MAX];
203 
204 /*
205  * Make lock validator output more readable. (we pre-construct these
206  * strings build-time, so that runtime initialization of socket
207  * locks is fast):
208  */
209 
210 #define _sock_locks(x)						  \
211   x "AF_UNSPEC",	x "AF_UNIX"     ,	x "AF_INET"     , \
212   x "AF_AX25"  ,	x "AF_IPX"      ,	x "AF_APPLETALK", \
213   x "AF_NETROM",	x "AF_BRIDGE"   ,	x "AF_ATMPVC"   , \
214   x "AF_X25"   ,	x "AF_INET6"    ,	x "AF_ROSE"     , \
215   x "AF_DECnet",	x "AF_NETBEUI"  ,	x "AF_SECURITY" , \
216   x "AF_KEY"   ,	x "AF_NETLINK"  ,	x "AF_PACKET"   , \
217   x "AF_ASH"   ,	x "AF_ECONET"   ,	x "AF_ATMSVC"   , \
218   x "AF_RDS"   ,	x "AF_SNA"      ,	x "AF_IRDA"     , \
219   x "AF_PPPOX" ,	x "AF_WANPIPE"  ,	x "AF_LLC"      , \
220   x "27"       ,	x "28"          ,	x "AF_CAN"      , \
221   x "AF_TIPC"  ,	x "AF_BLUETOOTH",	x "IUCV"        , \
222   x "AF_RXRPC" ,	x "AF_ISDN"     ,	x "AF_PHONET"   , \
223   x "AF_IEEE802154",	x "AF_CAIF"	,	x "AF_ALG"      , \
224   x "AF_NFC"   ,	x "AF_VSOCK"    ,	x "AF_KCM"      , \
225   x "AF_QIPCRTR",	x "AF_SMC"	,	x "AF_XDP"	, \
226   x "AF_MAX"
227 
228 static const char *const af_family_key_strings[AF_MAX+1] = {
229 	_sock_locks("sk_lock-")
230 };
231 static const char *const af_family_slock_key_strings[AF_MAX+1] = {
232 	_sock_locks("slock-")
233 };
234 static const char *const af_family_clock_key_strings[AF_MAX+1] = {
235 	_sock_locks("clock-")
236 };
237 
238 static const char *const af_family_kern_key_strings[AF_MAX+1] = {
239 	_sock_locks("k-sk_lock-")
240 };
241 static const char *const af_family_kern_slock_key_strings[AF_MAX+1] = {
242 	_sock_locks("k-slock-")
243 };
244 static const char *const af_family_kern_clock_key_strings[AF_MAX+1] = {
245 	_sock_locks("k-clock-")
246 };
247 static const char *const af_family_rlock_key_strings[AF_MAX+1] = {
248 	_sock_locks("rlock-")
249 };
250 static const char *const af_family_wlock_key_strings[AF_MAX+1] = {
251 	_sock_locks("wlock-")
252 };
253 static const char *const af_family_elock_key_strings[AF_MAX+1] = {
254 	_sock_locks("elock-")
255 };
256 
257 /*
258  * sk_callback_lock and sk queues locking rules are per-address-family,
259  * so split the lock classes by using a per-AF key:
260  */
261 static struct lock_class_key af_callback_keys[AF_MAX];
262 static struct lock_class_key af_rlock_keys[AF_MAX];
263 static struct lock_class_key af_wlock_keys[AF_MAX];
264 static struct lock_class_key af_elock_keys[AF_MAX];
265 static struct lock_class_key af_kern_callback_keys[AF_MAX];
266 
267 /* Run time adjustable parameters. */
268 __u32 sysctl_wmem_max __read_mostly = SK_WMEM_MAX;
269 EXPORT_SYMBOL(sysctl_wmem_max);
270 __u32 sysctl_rmem_max __read_mostly = SK_RMEM_MAX;
271 EXPORT_SYMBOL(sysctl_rmem_max);
272 __u32 sysctl_wmem_default __read_mostly = SK_WMEM_MAX;
273 __u32 sysctl_rmem_default __read_mostly = SK_RMEM_MAX;
274 
275 /* Maximal space eaten by iovec or ancillary data plus some space */
276 int sysctl_optmem_max __read_mostly = sizeof(unsigned long)*(2*UIO_MAXIOV+512);
277 EXPORT_SYMBOL(sysctl_optmem_max);
278 
279 int sysctl_tstamp_allow_data __read_mostly = 1;
280 
281 DEFINE_STATIC_KEY_FALSE(memalloc_socks_key);
282 EXPORT_SYMBOL_GPL(memalloc_socks_key);
283 
284 /**
285  * sk_set_memalloc - sets %SOCK_MEMALLOC
286  * @sk: socket to set it on
287  *
288  * Set %SOCK_MEMALLOC on a socket for access to emergency reserves.
289  * It's the responsibility of the admin to adjust min_free_kbytes
290  * to meet the requirements
291  */
292 void sk_set_memalloc(struct sock *sk)
293 {
294 	sock_set_flag(sk, SOCK_MEMALLOC);
295 	sk->sk_allocation |= __GFP_MEMALLOC;
296 	static_branch_inc(&memalloc_socks_key);
297 }
298 EXPORT_SYMBOL_GPL(sk_set_memalloc);
299 
300 void sk_clear_memalloc(struct sock *sk)
301 {
302 	sock_reset_flag(sk, SOCK_MEMALLOC);
303 	sk->sk_allocation &= ~__GFP_MEMALLOC;
304 	static_branch_dec(&memalloc_socks_key);
305 
306 	/*
307 	 * SOCK_MEMALLOC is allowed to ignore rmem limits to ensure forward
308 	 * progress of swapping. SOCK_MEMALLOC may be cleared while
309 	 * it has rmem allocations due to the last swapfile being deactivated
310 	 * but there is a risk that the socket is unusable due to exceeding
311 	 * the rmem limits. Reclaim the reserves and obey rmem limits again.
312 	 */
313 	sk_mem_reclaim(sk);
314 }
315 EXPORT_SYMBOL_GPL(sk_clear_memalloc);
316 
317 int __sk_backlog_rcv(struct sock *sk, struct sk_buff *skb)
318 {
319 	int ret;
320 	unsigned int noreclaim_flag;
321 
322 	/* these should have been dropped before queueing */
323 	BUG_ON(!sock_flag(sk, SOCK_MEMALLOC));
324 
325 	noreclaim_flag = memalloc_noreclaim_save();
326 	ret = sk->sk_backlog_rcv(sk, skb);
327 	memalloc_noreclaim_restore(noreclaim_flag);
328 
329 	return ret;
330 }
331 EXPORT_SYMBOL(__sk_backlog_rcv);
332 
333 static int sock_get_timeout(long timeo, void *optval, bool old_timeval)
334 {
335 	struct __kernel_sock_timeval tv;
336 	int size;
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 		size = sizeof(old_tv);
358 	} else {
359 		*(struct __kernel_sock_timeval *)optval = tv;
360 		size = sizeof(tv);
361 	}
362 
363 	return size;
364 }
365 
366 static int sock_set_timeout(long *timeo_p, char __user *optval, int optlen, bool old_timeval)
367 {
368 	struct __kernel_sock_timeval tv;
369 
370 	if (old_timeval && in_compat_syscall() && !COMPAT_USE_64BIT_TIME) {
371 		struct old_timeval32 tv32;
372 
373 		if (optlen < sizeof(tv32))
374 			return -EINVAL;
375 
376 		if (copy_from_user(&tv32, optval, sizeof(tv32)))
377 			return -EFAULT;
378 		tv.tv_sec = tv32.tv_sec;
379 		tv.tv_usec = tv32.tv_usec;
380 	} else if (old_timeval) {
381 		struct __kernel_old_timeval old_tv;
382 
383 		if (optlen < sizeof(old_tv))
384 			return -EINVAL;
385 		if (copy_from_user(&old_tv, optval, sizeof(old_tv)))
386 			return -EFAULT;
387 		tv.tv_sec = old_tv.tv_sec;
388 		tv.tv_usec = old_tv.tv_usec;
389 	} else {
390 		if (optlen < sizeof(tv))
391 			return -EINVAL;
392 		if (copy_from_user(&tv, optval, sizeof(tv)))
393 			return -EFAULT;
394 	}
395 	if (tv.tv_usec < 0 || tv.tv_usec >= USEC_PER_SEC)
396 		return -EDOM;
397 
398 	if (tv.tv_sec < 0) {
399 		static int warned __read_mostly;
400 
401 		*timeo_p = 0;
402 		if (warned < 10 && net_ratelimit()) {
403 			warned++;
404 			pr_info("%s: `%s' (pid %d) tries to set negative timeout\n",
405 				__func__, current->comm, task_pid_nr(current));
406 		}
407 		return 0;
408 	}
409 	*timeo_p = MAX_SCHEDULE_TIMEOUT;
410 	if (tv.tv_sec == 0 && tv.tv_usec == 0)
411 		return 0;
412 	if (tv.tv_sec < (MAX_SCHEDULE_TIMEOUT / HZ - 1))
413 		*timeo_p = tv.tv_sec * HZ + DIV_ROUND_UP((unsigned long)tv.tv_usec, USEC_PER_SEC / HZ);
414 	return 0;
415 }
416 
417 static void sock_warn_obsolete_bsdism(const char *name)
418 {
419 	static int warned;
420 	static char warncomm[TASK_COMM_LEN];
421 	if (strcmp(warncomm, current->comm) && warned < 5) {
422 		strcpy(warncomm,  current->comm);
423 		pr_warn("process `%s' is using obsolete %s SO_BSDCOMPAT\n",
424 			warncomm, name);
425 		warned++;
426 	}
427 }
428 
429 static bool sock_needs_netstamp(const struct sock *sk)
430 {
431 	switch (sk->sk_family) {
432 	case AF_UNSPEC:
433 	case AF_UNIX:
434 		return false;
435 	default:
436 		return true;
437 	}
438 }
439 
440 static void sock_disable_timestamp(struct sock *sk, unsigned long flags)
441 {
442 	if (sk->sk_flags & flags) {
443 		sk->sk_flags &= ~flags;
444 		if (sock_needs_netstamp(sk) &&
445 		    !(sk->sk_flags & SK_FLAGS_TIMESTAMP))
446 			net_disable_timestamp();
447 	}
448 }
449 
450 
451 int __sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
452 {
453 	unsigned long flags;
454 	struct sk_buff_head *list = &sk->sk_receive_queue;
455 
456 	if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf) {
457 		atomic_inc(&sk->sk_drops);
458 		trace_sock_rcvqueue_full(sk, skb);
459 		return -ENOMEM;
460 	}
461 
462 	if (!sk_rmem_schedule(sk, skb, skb->truesize)) {
463 		atomic_inc(&sk->sk_drops);
464 		return -ENOBUFS;
465 	}
466 
467 	skb->dev = NULL;
468 	skb_set_owner_r(skb, sk);
469 
470 	/* we escape from rcu protected region, make sure we dont leak
471 	 * a norefcounted dst
472 	 */
473 	skb_dst_force(skb);
474 
475 	spin_lock_irqsave(&list->lock, flags);
476 	sock_skb_set_dropcount(sk, skb);
477 	__skb_queue_tail(list, skb);
478 	spin_unlock_irqrestore(&list->lock, flags);
479 
480 	if (!sock_flag(sk, SOCK_DEAD))
481 		sk->sk_data_ready(sk);
482 	return 0;
483 }
484 EXPORT_SYMBOL(__sock_queue_rcv_skb);
485 
486 int sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
487 {
488 	int err;
489 
490 	err = sk_filter(sk, skb);
491 	if (err)
492 		return err;
493 
494 	return __sock_queue_rcv_skb(sk, skb);
495 }
496 EXPORT_SYMBOL(sock_queue_rcv_skb);
497 
498 int __sk_receive_skb(struct sock *sk, struct sk_buff *skb,
499 		     const int nested, unsigned int trim_cap, bool refcounted)
500 {
501 	int rc = NET_RX_SUCCESS;
502 
503 	if (sk_filter_trim_cap(sk, skb, trim_cap))
504 		goto discard_and_relse;
505 
506 	skb->dev = NULL;
507 
508 	if (sk_rcvqueues_full(sk, sk->sk_rcvbuf)) {
509 		atomic_inc(&sk->sk_drops);
510 		goto discard_and_relse;
511 	}
512 	if (nested)
513 		bh_lock_sock_nested(sk);
514 	else
515 		bh_lock_sock(sk);
516 	if (!sock_owned_by_user(sk)) {
517 		/*
518 		 * trylock + unlock semantics:
519 		 */
520 		mutex_acquire(&sk->sk_lock.dep_map, 0, 1, _RET_IP_);
521 
522 		rc = sk_backlog_rcv(sk, skb);
523 
524 		mutex_release(&sk->sk_lock.dep_map, 1, _RET_IP_);
525 	} else if (sk_add_backlog(sk, skb, sk->sk_rcvbuf)) {
526 		bh_unlock_sock(sk);
527 		atomic_inc(&sk->sk_drops);
528 		goto discard_and_relse;
529 	}
530 
531 	bh_unlock_sock(sk);
532 out:
533 	if (refcounted)
534 		sock_put(sk);
535 	return rc;
536 discard_and_relse:
537 	kfree_skb(skb);
538 	goto out;
539 }
540 EXPORT_SYMBOL(__sk_receive_skb);
541 
542 struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie)
543 {
544 	struct dst_entry *dst = __sk_dst_get(sk);
545 
546 	if (dst && dst->obsolete && dst->ops->check(dst, cookie) == NULL) {
547 		sk_tx_queue_clear(sk);
548 		sk->sk_dst_pending_confirm = 0;
549 		RCU_INIT_POINTER(sk->sk_dst_cache, NULL);
550 		dst_release(dst);
551 		return NULL;
552 	}
553 
554 	return dst;
555 }
556 EXPORT_SYMBOL(__sk_dst_check);
557 
558 struct dst_entry *sk_dst_check(struct sock *sk, u32 cookie)
559 {
560 	struct dst_entry *dst = sk_dst_get(sk);
561 
562 	if (dst && dst->obsolete && dst->ops->check(dst, cookie) == NULL) {
563 		sk_dst_reset(sk);
564 		dst_release(dst);
565 		return NULL;
566 	}
567 
568 	return dst;
569 }
570 EXPORT_SYMBOL(sk_dst_check);
571 
572 static int sock_setbindtodevice_locked(struct sock *sk, int ifindex)
573 {
574 	int ret = -ENOPROTOOPT;
575 #ifdef CONFIG_NETDEVICES
576 	struct net *net = sock_net(sk);
577 
578 	/* Sorry... */
579 	ret = -EPERM;
580 	if (!ns_capable(net->user_ns, CAP_NET_RAW))
581 		goto out;
582 
583 	ret = -EINVAL;
584 	if (ifindex < 0)
585 		goto out;
586 
587 	sk->sk_bound_dev_if = ifindex;
588 	if (sk->sk_prot->rehash)
589 		sk->sk_prot->rehash(sk);
590 	sk_dst_reset(sk);
591 
592 	ret = 0;
593 
594 out:
595 #endif
596 
597 	return ret;
598 }
599 
600 static int sock_setbindtodevice(struct sock *sk, char __user *optval,
601 				int optlen)
602 {
603 	int ret = -ENOPROTOOPT;
604 #ifdef CONFIG_NETDEVICES
605 	struct net *net = sock_net(sk);
606 	char devname[IFNAMSIZ];
607 	int index;
608 
609 	ret = -EINVAL;
610 	if (optlen < 0)
611 		goto out;
612 
613 	/* Bind this socket to a particular device like "eth0",
614 	 * as specified in the passed interface name. If the
615 	 * name is "" or the option length is zero the socket
616 	 * is not bound.
617 	 */
618 	if (optlen > IFNAMSIZ - 1)
619 		optlen = IFNAMSIZ - 1;
620 	memset(devname, 0, sizeof(devname));
621 
622 	ret = -EFAULT;
623 	if (copy_from_user(devname, optval, optlen))
624 		goto out;
625 
626 	index = 0;
627 	if (devname[0] != '\0') {
628 		struct net_device *dev;
629 
630 		rcu_read_lock();
631 		dev = dev_get_by_name_rcu(net, devname);
632 		if (dev)
633 			index = dev->ifindex;
634 		rcu_read_unlock();
635 		ret = -ENODEV;
636 		if (!dev)
637 			goto out;
638 	}
639 
640 	lock_sock(sk);
641 	ret = sock_setbindtodevice_locked(sk, index);
642 	release_sock(sk);
643 
644 out:
645 #endif
646 
647 	return ret;
648 }
649 
650 static int sock_getbindtodevice(struct sock *sk, char __user *optval,
651 				int __user *optlen, int len)
652 {
653 	int ret = -ENOPROTOOPT;
654 #ifdef CONFIG_NETDEVICES
655 	struct net *net = sock_net(sk);
656 	char devname[IFNAMSIZ];
657 
658 	if (sk->sk_bound_dev_if == 0) {
659 		len = 0;
660 		goto zero;
661 	}
662 
663 	ret = -EINVAL;
664 	if (len < IFNAMSIZ)
665 		goto out;
666 
667 	ret = netdev_get_name(net, devname, sk->sk_bound_dev_if);
668 	if (ret)
669 		goto out;
670 
671 	len = strlen(devname) + 1;
672 
673 	ret = -EFAULT;
674 	if (copy_to_user(optval, devname, len))
675 		goto out;
676 
677 zero:
678 	ret = -EFAULT;
679 	if (put_user(len, optlen))
680 		goto out;
681 
682 	ret = 0;
683 
684 out:
685 #endif
686 
687 	return ret;
688 }
689 
690 static inline void sock_valbool_flag(struct sock *sk, int bit, int valbool)
691 {
692 	if (valbool)
693 		sock_set_flag(sk, bit);
694 	else
695 		sock_reset_flag(sk, bit);
696 }
697 
698 bool sk_mc_loop(struct sock *sk)
699 {
700 	if (dev_recursion_level())
701 		return false;
702 	if (!sk)
703 		return true;
704 	switch (sk->sk_family) {
705 	case AF_INET:
706 		return inet_sk(sk)->mc_loop;
707 #if IS_ENABLED(CONFIG_IPV6)
708 	case AF_INET6:
709 		return inet6_sk(sk)->mc_loop;
710 #endif
711 	}
712 	WARN_ON(1);
713 	return true;
714 }
715 EXPORT_SYMBOL(sk_mc_loop);
716 
717 /*
718  *	This is meant for all protocols to use and covers goings on
719  *	at the socket level. Everything here is generic.
720  */
721 
722 int sock_setsockopt(struct socket *sock, int level, int optname,
723 		    char __user *optval, unsigned int optlen)
724 {
725 	struct sock_txtime sk_txtime;
726 	struct sock *sk = sock->sk;
727 	int val;
728 	int valbool;
729 	struct linger ling;
730 	int ret = 0;
731 
732 	/*
733 	 *	Options without arguments
734 	 */
735 
736 	if (optname == SO_BINDTODEVICE)
737 		return sock_setbindtodevice(sk, optval, optlen);
738 
739 	if (optlen < sizeof(int))
740 		return -EINVAL;
741 
742 	if (get_user(val, (int __user *)optval))
743 		return -EFAULT;
744 
745 	valbool = val ? 1 : 0;
746 
747 	lock_sock(sk);
748 
749 	switch (optname) {
750 	case SO_DEBUG:
751 		if (val && !capable(CAP_NET_ADMIN))
752 			ret = -EACCES;
753 		else
754 			sock_valbool_flag(sk, SOCK_DBG, valbool);
755 		break;
756 	case SO_REUSEADDR:
757 		sk->sk_reuse = (valbool ? SK_CAN_REUSE : SK_NO_REUSE);
758 		break;
759 	case SO_REUSEPORT:
760 		sk->sk_reuseport = valbool;
761 		break;
762 	case SO_TYPE:
763 	case SO_PROTOCOL:
764 	case SO_DOMAIN:
765 	case SO_ERROR:
766 		ret = -ENOPROTOOPT;
767 		break;
768 	case SO_DONTROUTE:
769 		sock_valbool_flag(sk, SOCK_LOCALROUTE, valbool);
770 		sk_dst_reset(sk);
771 		break;
772 	case SO_BROADCAST:
773 		sock_valbool_flag(sk, SOCK_BROADCAST, valbool);
774 		break;
775 	case SO_SNDBUF:
776 		/* Don't error on this BSD doesn't and if you think
777 		 * about it this is right. Otherwise apps have to
778 		 * play 'guess the biggest size' games. RCVBUF/SNDBUF
779 		 * are treated in BSD as hints
780 		 */
781 		val = min_t(u32, val, sysctl_wmem_max);
782 set_sndbuf:
783 		/* Ensure val * 2 fits into an int, to prevent max_t()
784 		 * from treating it as a negative value.
785 		 */
786 		val = min_t(int, val, INT_MAX / 2);
787 		sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
788 		sk->sk_sndbuf = max_t(int, val * 2, SOCK_MIN_SNDBUF);
789 		/* Wake up sending tasks if we upped the value. */
790 		sk->sk_write_space(sk);
791 		break;
792 
793 	case SO_SNDBUFFORCE:
794 		if (!capable(CAP_NET_ADMIN)) {
795 			ret = -EPERM;
796 			break;
797 		}
798 
799 		/* No negative values (to prevent underflow, as val will be
800 		 * multiplied by 2).
801 		 */
802 		if (val < 0)
803 			val = 0;
804 		goto set_sndbuf;
805 
806 	case SO_RCVBUF:
807 		/* Don't error on this BSD doesn't and if you think
808 		 * about it this is right. Otherwise apps have to
809 		 * play 'guess the biggest size' games. RCVBUF/SNDBUF
810 		 * are treated in BSD as hints
811 		 */
812 		val = min_t(u32, val, sysctl_rmem_max);
813 set_rcvbuf:
814 		/* Ensure val * 2 fits into an int, to prevent max_t()
815 		 * from treating it as a negative value.
816 		 */
817 		val = min_t(int, val, INT_MAX / 2);
818 		sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
819 		/*
820 		 * We double it on the way in to account for
821 		 * "struct sk_buff" etc. overhead.   Applications
822 		 * assume that the SO_RCVBUF setting they make will
823 		 * allow that much actual data to be received on that
824 		 * socket.
825 		 *
826 		 * Applications are unaware that "struct sk_buff" and
827 		 * other overheads allocate from the receive buffer
828 		 * during socket buffer allocation.
829 		 *
830 		 * And after considering the possible alternatives,
831 		 * returning the value we actually used in getsockopt
832 		 * is the most desirable behavior.
833 		 */
834 		sk->sk_rcvbuf = max_t(int, val * 2, SOCK_MIN_RCVBUF);
835 		break;
836 
837 	case SO_RCVBUFFORCE:
838 		if (!capable(CAP_NET_ADMIN)) {
839 			ret = -EPERM;
840 			break;
841 		}
842 
843 		/* No negative values (to prevent underflow, as val will be
844 		 * multiplied by 2).
845 		 */
846 		if (val < 0)
847 			val = 0;
848 		goto set_rcvbuf;
849 
850 	case SO_KEEPALIVE:
851 		if (sk->sk_prot->keepalive)
852 			sk->sk_prot->keepalive(sk, valbool);
853 		sock_valbool_flag(sk, SOCK_KEEPOPEN, valbool);
854 		break;
855 
856 	case SO_OOBINLINE:
857 		sock_valbool_flag(sk, SOCK_URGINLINE, valbool);
858 		break;
859 
860 	case SO_NO_CHECK:
861 		sk->sk_no_check_tx = valbool;
862 		break;
863 
864 	case SO_PRIORITY:
865 		if ((val >= 0 && val <= 6) ||
866 		    ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
867 			sk->sk_priority = val;
868 		else
869 			ret = -EPERM;
870 		break;
871 
872 	case SO_LINGER:
873 		if (optlen < sizeof(ling)) {
874 			ret = -EINVAL;	/* 1003.1g */
875 			break;
876 		}
877 		if (copy_from_user(&ling, optval, sizeof(ling))) {
878 			ret = -EFAULT;
879 			break;
880 		}
881 		if (!ling.l_onoff)
882 			sock_reset_flag(sk, SOCK_LINGER);
883 		else {
884 #if (BITS_PER_LONG == 32)
885 			if ((unsigned int)ling.l_linger >= MAX_SCHEDULE_TIMEOUT/HZ)
886 				sk->sk_lingertime = MAX_SCHEDULE_TIMEOUT;
887 			else
888 #endif
889 				sk->sk_lingertime = (unsigned int)ling.l_linger * HZ;
890 			sock_set_flag(sk, SOCK_LINGER);
891 		}
892 		break;
893 
894 	case SO_BSDCOMPAT:
895 		sock_warn_obsolete_bsdism("setsockopt");
896 		break;
897 
898 	case SO_PASSCRED:
899 		if (valbool)
900 			set_bit(SOCK_PASSCRED, &sock->flags);
901 		else
902 			clear_bit(SOCK_PASSCRED, &sock->flags);
903 		break;
904 
905 	case SO_TIMESTAMP_OLD:
906 	case SO_TIMESTAMP_NEW:
907 	case SO_TIMESTAMPNS_OLD:
908 	case SO_TIMESTAMPNS_NEW:
909 		if (valbool)  {
910 			if (optname == SO_TIMESTAMP_NEW || optname == SO_TIMESTAMPNS_NEW)
911 				sock_set_flag(sk, SOCK_TSTAMP_NEW);
912 			else
913 				sock_reset_flag(sk, SOCK_TSTAMP_NEW);
914 
915 			if (optname == SO_TIMESTAMP_OLD || optname == SO_TIMESTAMP_NEW)
916 				sock_reset_flag(sk, SOCK_RCVTSTAMPNS);
917 			else
918 				sock_set_flag(sk, SOCK_RCVTSTAMPNS);
919 			sock_set_flag(sk, SOCK_RCVTSTAMP);
920 			sock_enable_timestamp(sk, SOCK_TIMESTAMP);
921 		} else {
922 			sock_reset_flag(sk, SOCK_RCVTSTAMP);
923 			sock_reset_flag(sk, SOCK_RCVTSTAMPNS);
924 			sock_reset_flag(sk, SOCK_TSTAMP_NEW);
925 		}
926 		break;
927 
928 	case SO_TIMESTAMPING_NEW:
929 		sock_set_flag(sk, SOCK_TSTAMP_NEW);
930 		/* fall through */
931 	case SO_TIMESTAMPING_OLD:
932 		if (val & ~SOF_TIMESTAMPING_MASK) {
933 			ret = -EINVAL;
934 			break;
935 		}
936 
937 		if (val & SOF_TIMESTAMPING_OPT_ID &&
938 		    !(sk->sk_tsflags & SOF_TIMESTAMPING_OPT_ID)) {
939 			if (sk->sk_protocol == IPPROTO_TCP &&
940 			    sk->sk_type == SOCK_STREAM) {
941 				if ((1 << sk->sk_state) &
942 				    (TCPF_CLOSE | TCPF_LISTEN)) {
943 					ret = -EINVAL;
944 					break;
945 				}
946 				sk->sk_tskey = tcp_sk(sk)->snd_una;
947 			} else {
948 				sk->sk_tskey = 0;
949 			}
950 		}
951 
952 		if (val & SOF_TIMESTAMPING_OPT_STATS &&
953 		    !(val & SOF_TIMESTAMPING_OPT_TSONLY)) {
954 			ret = -EINVAL;
955 			break;
956 		}
957 
958 		sk->sk_tsflags = val;
959 		if (val & SOF_TIMESTAMPING_RX_SOFTWARE)
960 			sock_enable_timestamp(sk,
961 					      SOCK_TIMESTAMPING_RX_SOFTWARE);
962 		else {
963 			if (optname == SO_TIMESTAMPING_NEW)
964 				sock_reset_flag(sk, SOCK_TSTAMP_NEW);
965 
966 			sock_disable_timestamp(sk,
967 					       (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE));
968 		}
969 		break;
970 
971 	case SO_RCVLOWAT:
972 		if (val < 0)
973 			val = INT_MAX;
974 		if (sock->ops->set_rcvlowat)
975 			ret = sock->ops->set_rcvlowat(sk, val);
976 		else
977 			sk->sk_rcvlowat = val ? : 1;
978 		break;
979 
980 	case SO_RCVTIMEO_OLD:
981 	case SO_RCVTIMEO_NEW:
982 		ret = sock_set_timeout(&sk->sk_rcvtimeo, optval, optlen, optname == SO_RCVTIMEO_OLD);
983 		break;
984 
985 	case SO_SNDTIMEO_OLD:
986 	case SO_SNDTIMEO_NEW:
987 		ret = sock_set_timeout(&sk->sk_sndtimeo, optval, optlen, optname == SO_SNDTIMEO_OLD);
988 		break;
989 
990 	case SO_ATTACH_FILTER:
991 		ret = -EINVAL;
992 		if (optlen == sizeof(struct sock_fprog)) {
993 			struct sock_fprog fprog;
994 
995 			ret = -EFAULT;
996 			if (copy_from_user(&fprog, optval, sizeof(fprog)))
997 				break;
998 
999 			ret = sk_attach_filter(&fprog, sk);
1000 		}
1001 		break;
1002 
1003 	case SO_ATTACH_BPF:
1004 		ret = -EINVAL;
1005 		if (optlen == sizeof(u32)) {
1006 			u32 ufd;
1007 
1008 			ret = -EFAULT;
1009 			if (copy_from_user(&ufd, optval, sizeof(ufd)))
1010 				break;
1011 
1012 			ret = sk_attach_bpf(ufd, sk);
1013 		}
1014 		break;
1015 
1016 	case SO_ATTACH_REUSEPORT_CBPF:
1017 		ret = -EINVAL;
1018 		if (optlen == sizeof(struct sock_fprog)) {
1019 			struct sock_fprog fprog;
1020 
1021 			ret = -EFAULT;
1022 			if (copy_from_user(&fprog, optval, sizeof(fprog)))
1023 				break;
1024 
1025 			ret = sk_reuseport_attach_filter(&fprog, sk);
1026 		}
1027 		break;
1028 
1029 	case SO_ATTACH_REUSEPORT_EBPF:
1030 		ret = -EINVAL;
1031 		if (optlen == sizeof(u32)) {
1032 			u32 ufd;
1033 
1034 			ret = -EFAULT;
1035 			if (copy_from_user(&ufd, optval, sizeof(ufd)))
1036 				break;
1037 
1038 			ret = sk_reuseport_attach_bpf(ufd, sk);
1039 		}
1040 		break;
1041 
1042 	case SO_DETACH_REUSEPORT_BPF:
1043 		ret = reuseport_detach_prog(sk);
1044 		break;
1045 
1046 	case SO_DETACH_FILTER:
1047 		ret = sk_detach_filter(sk);
1048 		break;
1049 
1050 	case SO_LOCK_FILTER:
1051 		if (sock_flag(sk, SOCK_FILTER_LOCKED) && !valbool)
1052 			ret = -EPERM;
1053 		else
1054 			sock_valbool_flag(sk, SOCK_FILTER_LOCKED, valbool);
1055 		break;
1056 
1057 	case SO_PASSSEC:
1058 		if (valbool)
1059 			set_bit(SOCK_PASSSEC, &sock->flags);
1060 		else
1061 			clear_bit(SOCK_PASSSEC, &sock->flags);
1062 		break;
1063 	case SO_MARK:
1064 		if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) {
1065 			ret = -EPERM;
1066 		} else if (val != sk->sk_mark) {
1067 			sk->sk_mark = val;
1068 			sk_dst_reset(sk);
1069 		}
1070 		break;
1071 
1072 	case SO_RXQ_OVFL:
1073 		sock_valbool_flag(sk, SOCK_RXQ_OVFL, valbool);
1074 		break;
1075 
1076 	case SO_WIFI_STATUS:
1077 		sock_valbool_flag(sk, SOCK_WIFI_STATUS, valbool);
1078 		break;
1079 
1080 	case SO_PEEK_OFF:
1081 		if (sock->ops->set_peek_off)
1082 			ret = sock->ops->set_peek_off(sk, val);
1083 		else
1084 			ret = -EOPNOTSUPP;
1085 		break;
1086 
1087 	case SO_NOFCS:
1088 		sock_valbool_flag(sk, SOCK_NOFCS, valbool);
1089 		break;
1090 
1091 	case SO_SELECT_ERR_QUEUE:
1092 		sock_valbool_flag(sk, SOCK_SELECT_ERR_QUEUE, valbool);
1093 		break;
1094 
1095 #ifdef CONFIG_NET_RX_BUSY_POLL
1096 	case SO_BUSY_POLL:
1097 		/* allow unprivileged users to decrease the value */
1098 		if ((val > sk->sk_ll_usec) && !capable(CAP_NET_ADMIN))
1099 			ret = -EPERM;
1100 		else {
1101 			if (val < 0)
1102 				ret = -EINVAL;
1103 			else
1104 				sk->sk_ll_usec = val;
1105 		}
1106 		break;
1107 #endif
1108 
1109 	case SO_MAX_PACING_RATE:
1110 		{
1111 		unsigned long ulval = (val == ~0U) ? ~0UL : val;
1112 
1113 		if (sizeof(ulval) != sizeof(val) &&
1114 		    optlen >= sizeof(ulval) &&
1115 		    get_user(ulval, (unsigned long __user *)optval)) {
1116 			ret = -EFAULT;
1117 			break;
1118 		}
1119 		if (ulval != ~0UL)
1120 			cmpxchg(&sk->sk_pacing_status,
1121 				SK_PACING_NONE,
1122 				SK_PACING_NEEDED);
1123 		sk->sk_max_pacing_rate = ulval;
1124 		sk->sk_pacing_rate = min(sk->sk_pacing_rate, ulval);
1125 		break;
1126 		}
1127 	case SO_INCOMING_CPU:
1128 		sk->sk_incoming_cpu = val;
1129 		break;
1130 
1131 	case SO_CNX_ADVICE:
1132 		if (val == 1)
1133 			dst_negative_advice(sk);
1134 		break;
1135 
1136 	case SO_ZEROCOPY:
1137 		if (sk->sk_family == PF_INET || sk->sk_family == PF_INET6) {
1138 			if (!((sk->sk_type == SOCK_STREAM &&
1139 			       sk->sk_protocol == IPPROTO_TCP) ||
1140 			      (sk->sk_type == SOCK_DGRAM &&
1141 			       sk->sk_protocol == IPPROTO_UDP)))
1142 				ret = -ENOTSUPP;
1143 		} else if (sk->sk_family != PF_RDS) {
1144 			ret = -ENOTSUPP;
1145 		}
1146 		if (!ret) {
1147 			if (val < 0 || val > 1)
1148 				ret = -EINVAL;
1149 			else
1150 				sock_valbool_flag(sk, SOCK_ZEROCOPY, valbool);
1151 		}
1152 		break;
1153 
1154 	case SO_TXTIME:
1155 		if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) {
1156 			ret = -EPERM;
1157 		} else if (optlen != sizeof(struct sock_txtime)) {
1158 			ret = -EINVAL;
1159 		} else if (copy_from_user(&sk_txtime, optval,
1160 			   sizeof(struct sock_txtime))) {
1161 			ret = -EFAULT;
1162 		} else if (sk_txtime.flags & ~SOF_TXTIME_FLAGS_MASK) {
1163 			ret = -EINVAL;
1164 		} else {
1165 			sock_valbool_flag(sk, SOCK_TXTIME, true);
1166 			sk->sk_clockid = sk_txtime.clockid;
1167 			sk->sk_txtime_deadline_mode =
1168 				!!(sk_txtime.flags & SOF_TXTIME_DEADLINE_MODE);
1169 			sk->sk_txtime_report_errors =
1170 				!!(sk_txtime.flags & SOF_TXTIME_REPORT_ERRORS);
1171 		}
1172 		break;
1173 
1174 	case SO_BINDTOIFINDEX:
1175 		ret = sock_setbindtodevice_locked(sk, val);
1176 		break;
1177 
1178 	default:
1179 		ret = -ENOPROTOOPT;
1180 		break;
1181 	}
1182 	release_sock(sk);
1183 	return ret;
1184 }
1185 EXPORT_SYMBOL(sock_setsockopt);
1186 
1187 
1188 static void cred_to_ucred(struct pid *pid, const struct cred *cred,
1189 			  struct ucred *ucred)
1190 {
1191 	ucred->pid = pid_vnr(pid);
1192 	ucred->uid = ucred->gid = -1;
1193 	if (cred) {
1194 		struct user_namespace *current_ns = current_user_ns();
1195 
1196 		ucred->uid = from_kuid_munged(current_ns, cred->euid);
1197 		ucred->gid = from_kgid_munged(current_ns, cred->egid);
1198 	}
1199 }
1200 
1201 static int groups_to_user(gid_t __user *dst, const struct group_info *src)
1202 {
1203 	struct user_namespace *user_ns = current_user_ns();
1204 	int i;
1205 
1206 	for (i = 0; i < src->ngroups; i++)
1207 		if (put_user(from_kgid_munged(user_ns, src->gid[i]), dst + i))
1208 			return -EFAULT;
1209 
1210 	return 0;
1211 }
1212 
1213 int sock_getsockopt(struct socket *sock, int level, int optname,
1214 		    char __user *optval, int __user *optlen)
1215 {
1216 	struct sock *sk = sock->sk;
1217 
1218 	union {
1219 		int val;
1220 		u64 val64;
1221 		unsigned long ulval;
1222 		struct linger ling;
1223 		struct old_timeval32 tm32;
1224 		struct __kernel_old_timeval tm;
1225 		struct  __kernel_sock_timeval stm;
1226 		struct sock_txtime txtime;
1227 	} v;
1228 
1229 	int lv = sizeof(int);
1230 	int len;
1231 
1232 	if (get_user(len, optlen))
1233 		return -EFAULT;
1234 	if (len < 0)
1235 		return -EINVAL;
1236 
1237 	memset(&v, 0, sizeof(v));
1238 
1239 	switch (optname) {
1240 	case SO_DEBUG:
1241 		v.val = sock_flag(sk, SOCK_DBG);
1242 		break;
1243 
1244 	case SO_DONTROUTE:
1245 		v.val = sock_flag(sk, SOCK_LOCALROUTE);
1246 		break;
1247 
1248 	case SO_BROADCAST:
1249 		v.val = sock_flag(sk, SOCK_BROADCAST);
1250 		break;
1251 
1252 	case SO_SNDBUF:
1253 		v.val = sk->sk_sndbuf;
1254 		break;
1255 
1256 	case SO_RCVBUF:
1257 		v.val = sk->sk_rcvbuf;
1258 		break;
1259 
1260 	case SO_REUSEADDR:
1261 		v.val = sk->sk_reuse;
1262 		break;
1263 
1264 	case SO_REUSEPORT:
1265 		v.val = sk->sk_reuseport;
1266 		break;
1267 
1268 	case SO_KEEPALIVE:
1269 		v.val = sock_flag(sk, SOCK_KEEPOPEN);
1270 		break;
1271 
1272 	case SO_TYPE:
1273 		v.val = sk->sk_type;
1274 		break;
1275 
1276 	case SO_PROTOCOL:
1277 		v.val = sk->sk_protocol;
1278 		break;
1279 
1280 	case SO_DOMAIN:
1281 		v.val = sk->sk_family;
1282 		break;
1283 
1284 	case SO_ERROR:
1285 		v.val = -sock_error(sk);
1286 		if (v.val == 0)
1287 			v.val = xchg(&sk->sk_err_soft, 0);
1288 		break;
1289 
1290 	case SO_OOBINLINE:
1291 		v.val = sock_flag(sk, SOCK_URGINLINE);
1292 		break;
1293 
1294 	case SO_NO_CHECK:
1295 		v.val = sk->sk_no_check_tx;
1296 		break;
1297 
1298 	case SO_PRIORITY:
1299 		v.val = sk->sk_priority;
1300 		break;
1301 
1302 	case SO_LINGER:
1303 		lv		= sizeof(v.ling);
1304 		v.ling.l_onoff	= sock_flag(sk, SOCK_LINGER);
1305 		v.ling.l_linger	= sk->sk_lingertime / HZ;
1306 		break;
1307 
1308 	case SO_BSDCOMPAT:
1309 		sock_warn_obsolete_bsdism("getsockopt");
1310 		break;
1311 
1312 	case SO_TIMESTAMP_OLD:
1313 		v.val = sock_flag(sk, SOCK_RCVTSTAMP) &&
1314 				!sock_flag(sk, SOCK_TSTAMP_NEW) &&
1315 				!sock_flag(sk, SOCK_RCVTSTAMPNS);
1316 		break;
1317 
1318 	case SO_TIMESTAMPNS_OLD:
1319 		v.val = sock_flag(sk, SOCK_RCVTSTAMPNS) && !sock_flag(sk, SOCK_TSTAMP_NEW);
1320 		break;
1321 
1322 	case SO_TIMESTAMP_NEW:
1323 		v.val = sock_flag(sk, SOCK_RCVTSTAMP) && sock_flag(sk, SOCK_TSTAMP_NEW);
1324 		break;
1325 
1326 	case SO_TIMESTAMPNS_NEW:
1327 		v.val = sock_flag(sk, SOCK_RCVTSTAMPNS) && sock_flag(sk, SOCK_TSTAMP_NEW);
1328 		break;
1329 
1330 	case SO_TIMESTAMPING_OLD:
1331 		v.val = sk->sk_tsflags;
1332 		break;
1333 
1334 	case SO_RCVTIMEO_OLD:
1335 	case SO_RCVTIMEO_NEW:
1336 		lv = sock_get_timeout(sk->sk_rcvtimeo, &v, SO_RCVTIMEO_OLD == optname);
1337 		break;
1338 
1339 	case SO_SNDTIMEO_OLD:
1340 	case SO_SNDTIMEO_NEW:
1341 		lv = sock_get_timeout(sk->sk_sndtimeo, &v, SO_SNDTIMEO_OLD == optname);
1342 		break;
1343 
1344 	case SO_RCVLOWAT:
1345 		v.val = sk->sk_rcvlowat;
1346 		break;
1347 
1348 	case SO_SNDLOWAT:
1349 		v.val = 1;
1350 		break;
1351 
1352 	case SO_PASSCRED:
1353 		v.val = !!test_bit(SOCK_PASSCRED, &sock->flags);
1354 		break;
1355 
1356 	case SO_PEERCRED:
1357 	{
1358 		struct ucred peercred;
1359 		if (len > sizeof(peercred))
1360 			len = sizeof(peercred);
1361 		cred_to_ucred(sk->sk_peer_pid, sk->sk_peer_cred, &peercred);
1362 		if (copy_to_user(optval, &peercred, len))
1363 			return -EFAULT;
1364 		goto lenout;
1365 	}
1366 
1367 	case SO_PEERGROUPS:
1368 	{
1369 		int ret, n;
1370 
1371 		if (!sk->sk_peer_cred)
1372 			return -ENODATA;
1373 
1374 		n = sk->sk_peer_cred->group_info->ngroups;
1375 		if (len < n * sizeof(gid_t)) {
1376 			len = n * sizeof(gid_t);
1377 			return put_user(len, optlen) ? -EFAULT : -ERANGE;
1378 		}
1379 		len = n * sizeof(gid_t);
1380 
1381 		ret = groups_to_user((gid_t __user *)optval,
1382 				     sk->sk_peer_cred->group_info);
1383 		if (ret)
1384 			return ret;
1385 		goto lenout;
1386 	}
1387 
1388 	case SO_PEERNAME:
1389 	{
1390 		char address[128];
1391 
1392 		lv = sock->ops->getname(sock, (struct sockaddr *)address, 2);
1393 		if (lv < 0)
1394 			return -ENOTCONN;
1395 		if (lv < len)
1396 			return -EINVAL;
1397 		if (copy_to_user(optval, address, len))
1398 			return -EFAULT;
1399 		goto lenout;
1400 	}
1401 
1402 	/* Dubious BSD thing... Probably nobody even uses it, but
1403 	 * the UNIX standard wants it for whatever reason... -DaveM
1404 	 */
1405 	case SO_ACCEPTCONN:
1406 		v.val = sk->sk_state == TCP_LISTEN;
1407 		break;
1408 
1409 	case SO_PASSSEC:
1410 		v.val = !!test_bit(SOCK_PASSSEC, &sock->flags);
1411 		break;
1412 
1413 	case SO_PEERSEC:
1414 		return security_socket_getpeersec_stream(sock, optval, optlen, len);
1415 
1416 	case SO_MARK:
1417 		v.val = sk->sk_mark;
1418 		break;
1419 
1420 	case SO_RXQ_OVFL:
1421 		v.val = sock_flag(sk, SOCK_RXQ_OVFL);
1422 		break;
1423 
1424 	case SO_WIFI_STATUS:
1425 		v.val = sock_flag(sk, SOCK_WIFI_STATUS);
1426 		break;
1427 
1428 	case SO_PEEK_OFF:
1429 		if (!sock->ops->set_peek_off)
1430 			return -EOPNOTSUPP;
1431 
1432 		v.val = sk->sk_peek_off;
1433 		break;
1434 	case SO_NOFCS:
1435 		v.val = sock_flag(sk, SOCK_NOFCS);
1436 		break;
1437 
1438 	case SO_BINDTODEVICE:
1439 		return sock_getbindtodevice(sk, optval, optlen, len);
1440 
1441 	case SO_GET_FILTER:
1442 		len = sk_get_filter(sk, (struct sock_filter __user *)optval, len);
1443 		if (len < 0)
1444 			return len;
1445 
1446 		goto lenout;
1447 
1448 	case SO_LOCK_FILTER:
1449 		v.val = sock_flag(sk, SOCK_FILTER_LOCKED);
1450 		break;
1451 
1452 	case SO_BPF_EXTENSIONS:
1453 		v.val = bpf_tell_extensions();
1454 		break;
1455 
1456 	case SO_SELECT_ERR_QUEUE:
1457 		v.val = sock_flag(sk, SOCK_SELECT_ERR_QUEUE);
1458 		break;
1459 
1460 #ifdef CONFIG_NET_RX_BUSY_POLL
1461 	case SO_BUSY_POLL:
1462 		v.val = sk->sk_ll_usec;
1463 		break;
1464 #endif
1465 
1466 	case SO_MAX_PACING_RATE:
1467 		if (sizeof(v.ulval) != sizeof(v.val) && len >= sizeof(v.ulval)) {
1468 			lv = sizeof(v.ulval);
1469 			v.ulval = sk->sk_max_pacing_rate;
1470 		} else {
1471 			/* 32bit version */
1472 			v.val = min_t(unsigned long, sk->sk_max_pacing_rate, ~0U);
1473 		}
1474 		break;
1475 
1476 	case SO_INCOMING_CPU:
1477 		v.val = sk->sk_incoming_cpu;
1478 		break;
1479 
1480 	case SO_MEMINFO:
1481 	{
1482 		u32 meminfo[SK_MEMINFO_VARS];
1483 
1484 		sk_get_meminfo(sk, meminfo);
1485 
1486 		len = min_t(unsigned int, len, sizeof(meminfo));
1487 		if (copy_to_user(optval, &meminfo, len))
1488 			return -EFAULT;
1489 
1490 		goto lenout;
1491 	}
1492 
1493 #ifdef CONFIG_NET_RX_BUSY_POLL
1494 	case SO_INCOMING_NAPI_ID:
1495 		v.val = READ_ONCE(sk->sk_napi_id);
1496 
1497 		/* aggregate non-NAPI IDs down to 0 */
1498 		if (v.val < MIN_NAPI_ID)
1499 			v.val = 0;
1500 
1501 		break;
1502 #endif
1503 
1504 	case SO_COOKIE:
1505 		lv = sizeof(u64);
1506 		if (len < lv)
1507 			return -EINVAL;
1508 		v.val64 = sock_gen_cookie(sk);
1509 		break;
1510 
1511 	case SO_ZEROCOPY:
1512 		v.val = sock_flag(sk, SOCK_ZEROCOPY);
1513 		break;
1514 
1515 	case SO_TXTIME:
1516 		lv = sizeof(v.txtime);
1517 		v.txtime.clockid = sk->sk_clockid;
1518 		v.txtime.flags |= sk->sk_txtime_deadline_mode ?
1519 				  SOF_TXTIME_DEADLINE_MODE : 0;
1520 		v.txtime.flags |= sk->sk_txtime_report_errors ?
1521 				  SOF_TXTIME_REPORT_ERRORS : 0;
1522 		break;
1523 
1524 	case SO_BINDTOIFINDEX:
1525 		v.val = sk->sk_bound_dev_if;
1526 		break;
1527 
1528 	default:
1529 		/* We implement the SO_SNDLOWAT etc to not be settable
1530 		 * (1003.1g 7).
1531 		 */
1532 		return -ENOPROTOOPT;
1533 	}
1534 
1535 	if (len > lv)
1536 		len = lv;
1537 	if (copy_to_user(optval, &v, len))
1538 		return -EFAULT;
1539 lenout:
1540 	if (put_user(len, optlen))
1541 		return -EFAULT;
1542 	return 0;
1543 }
1544 
1545 /*
1546  * Initialize an sk_lock.
1547  *
1548  * (We also register the sk_lock with the lock validator.)
1549  */
1550 static inline void sock_lock_init(struct sock *sk)
1551 {
1552 	if (sk->sk_kern_sock)
1553 		sock_lock_init_class_and_name(
1554 			sk,
1555 			af_family_kern_slock_key_strings[sk->sk_family],
1556 			af_family_kern_slock_keys + sk->sk_family,
1557 			af_family_kern_key_strings[sk->sk_family],
1558 			af_family_kern_keys + sk->sk_family);
1559 	else
1560 		sock_lock_init_class_and_name(
1561 			sk,
1562 			af_family_slock_key_strings[sk->sk_family],
1563 			af_family_slock_keys + sk->sk_family,
1564 			af_family_key_strings[sk->sk_family],
1565 			af_family_keys + sk->sk_family);
1566 }
1567 
1568 /*
1569  * Copy all fields from osk to nsk but nsk->sk_refcnt must not change yet,
1570  * even temporarly, because of RCU lookups. sk_node should also be left as is.
1571  * We must not copy fields between sk_dontcopy_begin and sk_dontcopy_end
1572  */
1573 static void sock_copy(struct sock *nsk, const struct sock *osk)
1574 {
1575 #ifdef CONFIG_SECURITY_NETWORK
1576 	void *sptr = nsk->sk_security;
1577 #endif
1578 	memcpy(nsk, osk, offsetof(struct sock, sk_dontcopy_begin));
1579 
1580 	memcpy(&nsk->sk_dontcopy_end, &osk->sk_dontcopy_end,
1581 	       osk->sk_prot->obj_size - offsetof(struct sock, sk_dontcopy_end));
1582 
1583 #ifdef CONFIG_SECURITY_NETWORK
1584 	nsk->sk_security = sptr;
1585 	security_sk_clone(osk, nsk);
1586 #endif
1587 }
1588 
1589 static struct sock *sk_prot_alloc(struct proto *prot, gfp_t priority,
1590 		int family)
1591 {
1592 	struct sock *sk;
1593 	struct kmem_cache *slab;
1594 
1595 	slab = prot->slab;
1596 	if (slab != NULL) {
1597 		sk = kmem_cache_alloc(slab, priority & ~__GFP_ZERO);
1598 		if (!sk)
1599 			return sk;
1600 		if (want_init_on_alloc(priority))
1601 			sk_prot_clear_nulls(sk, prot->obj_size);
1602 	} else
1603 		sk = kmalloc(prot->obj_size, priority);
1604 
1605 	if (sk != NULL) {
1606 		if (security_sk_alloc(sk, family, priority))
1607 			goto out_free;
1608 
1609 		if (!try_module_get(prot->owner))
1610 			goto out_free_sec;
1611 		sk_tx_queue_clear(sk);
1612 	}
1613 
1614 	return sk;
1615 
1616 out_free_sec:
1617 	security_sk_free(sk);
1618 out_free:
1619 	if (slab != NULL)
1620 		kmem_cache_free(slab, sk);
1621 	else
1622 		kfree(sk);
1623 	return NULL;
1624 }
1625 
1626 static void sk_prot_free(struct proto *prot, struct sock *sk)
1627 {
1628 	struct kmem_cache *slab;
1629 	struct module *owner;
1630 
1631 	owner = prot->owner;
1632 	slab = prot->slab;
1633 
1634 	cgroup_sk_free(&sk->sk_cgrp_data);
1635 	mem_cgroup_sk_free(sk);
1636 	security_sk_free(sk);
1637 	if (slab != NULL)
1638 		kmem_cache_free(slab, sk);
1639 	else
1640 		kfree(sk);
1641 	module_put(owner);
1642 }
1643 
1644 /**
1645  *	sk_alloc - All socket objects are allocated here
1646  *	@net: the applicable net namespace
1647  *	@family: protocol family
1648  *	@priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
1649  *	@prot: struct proto associated with this new sock instance
1650  *	@kern: is this to be a kernel socket?
1651  */
1652 struct sock *sk_alloc(struct net *net, int family, gfp_t priority,
1653 		      struct proto *prot, int kern)
1654 {
1655 	struct sock *sk;
1656 
1657 	sk = sk_prot_alloc(prot, priority | __GFP_ZERO, family);
1658 	if (sk) {
1659 		sk->sk_family = family;
1660 		/*
1661 		 * See comment in struct sock definition to understand
1662 		 * why we need sk_prot_creator -acme
1663 		 */
1664 		sk->sk_prot = sk->sk_prot_creator = prot;
1665 		sk->sk_kern_sock = kern;
1666 		sock_lock_init(sk);
1667 		sk->sk_net_refcnt = kern ? 0 : 1;
1668 		if (likely(sk->sk_net_refcnt)) {
1669 			get_net(net);
1670 			sock_inuse_add(net, 1);
1671 		}
1672 
1673 		sock_net_set(sk, net);
1674 		refcount_set(&sk->sk_wmem_alloc, 1);
1675 
1676 		mem_cgroup_sk_alloc(sk);
1677 		cgroup_sk_alloc(&sk->sk_cgrp_data);
1678 		sock_update_classid(&sk->sk_cgrp_data);
1679 		sock_update_netprioidx(&sk->sk_cgrp_data);
1680 	}
1681 
1682 	return sk;
1683 }
1684 EXPORT_SYMBOL(sk_alloc);
1685 
1686 /* Sockets having SOCK_RCU_FREE will call this function after one RCU
1687  * grace period. This is the case for UDP sockets and TCP listeners.
1688  */
1689 static void __sk_destruct(struct rcu_head *head)
1690 {
1691 	struct sock *sk = container_of(head, struct sock, sk_rcu);
1692 	struct sk_filter *filter;
1693 
1694 	if (sk->sk_destruct)
1695 		sk->sk_destruct(sk);
1696 
1697 	filter = rcu_dereference_check(sk->sk_filter,
1698 				       refcount_read(&sk->sk_wmem_alloc) == 0);
1699 	if (filter) {
1700 		sk_filter_uncharge(sk, filter);
1701 		RCU_INIT_POINTER(sk->sk_filter, NULL);
1702 	}
1703 
1704 	sock_disable_timestamp(sk, SK_FLAGS_TIMESTAMP);
1705 
1706 #ifdef CONFIG_BPF_SYSCALL
1707 	bpf_sk_storage_free(sk);
1708 #endif
1709 
1710 	if (atomic_read(&sk->sk_omem_alloc))
1711 		pr_debug("%s: optmem leakage (%d bytes) detected\n",
1712 			 __func__, atomic_read(&sk->sk_omem_alloc));
1713 
1714 	if (sk->sk_frag.page) {
1715 		put_page(sk->sk_frag.page);
1716 		sk->sk_frag.page = NULL;
1717 	}
1718 
1719 	if (sk->sk_peer_cred)
1720 		put_cred(sk->sk_peer_cred);
1721 	put_pid(sk->sk_peer_pid);
1722 	if (likely(sk->sk_net_refcnt))
1723 		put_net(sock_net(sk));
1724 	sk_prot_free(sk->sk_prot_creator, sk);
1725 }
1726 
1727 void sk_destruct(struct sock *sk)
1728 {
1729 	bool use_call_rcu = sock_flag(sk, SOCK_RCU_FREE);
1730 
1731 	if (rcu_access_pointer(sk->sk_reuseport_cb)) {
1732 		reuseport_detach_sock(sk);
1733 		use_call_rcu = true;
1734 	}
1735 
1736 	if (use_call_rcu)
1737 		call_rcu(&sk->sk_rcu, __sk_destruct);
1738 	else
1739 		__sk_destruct(&sk->sk_rcu);
1740 }
1741 
1742 static void __sk_free(struct sock *sk)
1743 {
1744 	if (likely(sk->sk_net_refcnt))
1745 		sock_inuse_add(sock_net(sk), -1);
1746 
1747 	if (unlikely(sk->sk_net_refcnt && sock_diag_has_destroy_listeners(sk)))
1748 		sock_diag_broadcast_destroy(sk);
1749 	else
1750 		sk_destruct(sk);
1751 }
1752 
1753 void sk_free(struct sock *sk)
1754 {
1755 	/*
1756 	 * We subtract one from sk_wmem_alloc and can know if
1757 	 * some packets are still in some tx queue.
1758 	 * If not null, sock_wfree() will call __sk_free(sk) later
1759 	 */
1760 	if (refcount_dec_and_test(&sk->sk_wmem_alloc))
1761 		__sk_free(sk);
1762 }
1763 EXPORT_SYMBOL(sk_free);
1764 
1765 static void sk_init_common(struct sock *sk)
1766 {
1767 	skb_queue_head_init(&sk->sk_receive_queue);
1768 	skb_queue_head_init(&sk->sk_write_queue);
1769 	skb_queue_head_init(&sk->sk_error_queue);
1770 
1771 	rwlock_init(&sk->sk_callback_lock);
1772 	lockdep_set_class_and_name(&sk->sk_receive_queue.lock,
1773 			af_rlock_keys + sk->sk_family,
1774 			af_family_rlock_key_strings[sk->sk_family]);
1775 	lockdep_set_class_and_name(&sk->sk_write_queue.lock,
1776 			af_wlock_keys + sk->sk_family,
1777 			af_family_wlock_key_strings[sk->sk_family]);
1778 	lockdep_set_class_and_name(&sk->sk_error_queue.lock,
1779 			af_elock_keys + sk->sk_family,
1780 			af_family_elock_key_strings[sk->sk_family]);
1781 	lockdep_set_class_and_name(&sk->sk_callback_lock,
1782 			af_callback_keys + sk->sk_family,
1783 			af_family_clock_key_strings[sk->sk_family]);
1784 }
1785 
1786 /**
1787  *	sk_clone_lock - clone a socket, and lock its clone
1788  *	@sk: the socket to clone
1789  *	@priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
1790  *
1791  *	Caller must unlock socket even in error path (bh_unlock_sock(newsk))
1792  */
1793 struct sock *sk_clone_lock(const struct sock *sk, const gfp_t priority)
1794 {
1795 	struct sock *newsk;
1796 	bool is_charged = true;
1797 
1798 	newsk = sk_prot_alloc(sk->sk_prot, priority, sk->sk_family);
1799 	if (newsk != NULL) {
1800 		struct sk_filter *filter;
1801 
1802 		sock_copy(newsk, sk);
1803 
1804 		newsk->sk_prot_creator = sk->sk_prot;
1805 
1806 		/* SANITY */
1807 		if (likely(newsk->sk_net_refcnt))
1808 			get_net(sock_net(newsk));
1809 		sk_node_init(&newsk->sk_node);
1810 		sock_lock_init(newsk);
1811 		bh_lock_sock(newsk);
1812 		newsk->sk_backlog.head	= newsk->sk_backlog.tail = NULL;
1813 		newsk->sk_backlog.len = 0;
1814 
1815 		atomic_set(&newsk->sk_rmem_alloc, 0);
1816 		/*
1817 		 * sk_wmem_alloc set to one (see sk_free() and sock_wfree())
1818 		 */
1819 		refcount_set(&newsk->sk_wmem_alloc, 1);
1820 		atomic_set(&newsk->sk_omem_alloc, 0);
1821 		sk_init_common(newsk);
1822 
1823 		newsk->sk_dst_cache	= NULL;
1824 		newsk->sk_dst_pending_confirm = 0;
1825 		newsk->sk_wmem_queued	= 0;
1826 		newsk->sk_forward_alloc = 0;
1827 		atomic_set(&newsk->sk_drops, 0);
1828 		newsk->sk_send_head	= NULL;
1829 		newsk->sk_userlocks	= sk->sk_userlocks & ~SOCK_BINDPORT_LOCK;
1830 		atomic_set(&newsk->sk_zckey, 0);
1831 
1832 		sock_reset_flag(newsk, SOCK_DONE);
1833 		mem_cgroup_sk_alloc(newsk);
1834 		cgroup_sk_alloc(&newsk->sk_cgrp_data);
1835 
1836 		rcu_read_lock();
1837 		filter = rcu_dereference(sk->sk_filter);
1838 		if (filter != NULL)
1839 			/* though it's an empty new sock, the charging may fail
1840 			 * if sysctl_optmem_max was changed between creation of
1841 			 * original socket and cloning
1842 			 */
1843 			is_charged = sk_filter_charge(newsk, filter);
1844 		RCU_INIT_POINTER(newsk->sk_filter, filter);
1845 		rcu_read_unlock();
1846 
1847 		if (unlikely(!is_charged || xfrm_sk_clone_policy(newsk, sk))) {
1848 			/* We need to make sure that we don't uncharge the new
1849 			 * socket if we couldn't charge it in the first place
1850 			 * as otherwise we uncharge the parent's filter.
1851 			 */
1852 			if (!is_charged)
1853 				RCU_INIT_POINTER(newsk->sk_filter, NULL);
1854 			sk_free_unlock_clone(newsk);
1855 			newsk = NULL;
1856 			goto out;
1857 		}
1858 		RCU_INIT_POINTER(newsk->sk_reuseport_cb, NULL);
1859 
1860 		if (bpf_sk_storage_clone(sk, newsk)) {
1861 			sk_free_unlock_clone(newsk);
1862 			newsk = NULL;
1863 			goto out;
1864 		}
1865 
1866 		newsk->sk_err	   = 0;
1867 		newsk->sk_err_soft = 0;
1868 		newsk->sk_priority = 0;
1869 		newsk->sk_incoming_cpu = raw_smp_processor_id();
1870 		if (likely(newsk->sk_net_refcnt))
1871 			sock_inuse_add(sock_net(newsk), 1);
1872 
1873 		/*
1874 		 * Before updating sk_refcnt, we must commit prior changes to memory
1875 		 * (Documentation/RCU/rculist_nulls.txt for details)
1876 		 */
1877 		smp_wmb();
1878 		refcount_set(&newsk->sk_refcnt, 2);
1879 
1880 		/*
1881 		 * Increment the counter in the same struct proto as the master
1882 		 * sock (sk_refcnt_debug_inc uses newsk->sk_prot->socks, that
1883 		 * is the same as sk->sk_prot->socks, as this field was copied
1884 		 * with memcpy).
1885 		 *
1886 		 * This _changes_ the previous behaviour, where
1887 		 * tcp_create_openreq_child always was incrementing the
1888 		 * equivalent to tcp_prot->socks (inet_sock_nr), so this have
1889 		 * to be taken into account in all callers. -acme
1890 		 */
1891 		sk_refcnt_debug_inc(newsk);
1892 		sk_set_socket(newsk, NULL);
1893 		RCU_INIT_POINTER(newsk->sk_wq, NULL);
1894 
1895 		if (newsk->sk_prot->sockets_allocated)
1896 			sk_sockets_allocated_inc(newsk);
1897 
1898 		if (sock_needs_netstamp(sk) &&
1899 		    newsk->sk_flags & SK_FLAGS_TIMESTAMP)
1900 			net_enable_timestamp();
1901 	}
1902 out:
1903 	return newsk;
1904 }
1905 EXPORT_SYMBOL_GPL(sk_clone_lock);
1906 
1907 void sk_free_unlock_clone(struct sock *sk)
1908 {
1909 	/* It is still raw copy of parent, so invalidate
1910 	 * destructor and make plain sk_free() */
1911 	sk->sk_destruct = NULL;
1912 	bh_unlock_sock(sk);
1913 	sk_free(sk);
1914 }
1915 EXPORT_SYMBOL_GPL(sk_free_unlock_clone);
1916 
1917 void sk_setup_caps(struct sock *sk, struct dst_entry *dst)
1918 {
1919 	u32 max_segs = 1;
1920 
1921 	sk_dst_set(sk, dst);
1922 	sk->sk_route_caps = dst->dev->features | sk->sk_route_forced_caps;
1923 	if (sk->sk_route_caps & NETIF_F_GSO)
1924 		sk->sk_route_caps |= NETIF_F_GSO_SOFTWARE;
1925 	sk->sk_route_caps &= ~sk->sk_route_nocaps;
1926 	if (sk_can_gso(sk)) {
1927 		if (dst->header_len && !xfrm_dst_offload_ok(dst)) {
1928 			sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
1929 		} else {
1930 			sk->sk_route_caps |= NETIF_F_SG | NETIF_F_HW_CSUM;
1931 			sk->sk_gso_max_size = dst->dev->gso_max_size;
1932 			max_segs = max_t(u32, dst->dev->gso_max_segs, 1);
1933 		}
1934 	}
1935 	sk->sk_gso_max_segs = max_segs;
1936 }
1937 EXPORT_SYMBOL_GPL(sk_setup_caps);
1938 
1939 /*
1940  *	Simple resource managers for sockets.
1941  */
1942 
1943 
1944 /*
1945  * Write buffer destructor automatically called from kfree_skb.
1946  */
1947 void sock_wfree(struct sk_buff *skb)
1948 {
1949 	struct sock *sk = skb->sk;
1950 	unsigned int len = skb->truesize;
1951 
1952 	if (!sock_flag(sk, SOCK_USE_WRITE_QUEUE)) {
1953 		/*
1954 		 * Keep a reference on sk_wmem_alloc, this will be released
1955 		 * after sk_write_space() call
1956 		 */
1957 		WARN_ON(refcount_sub_and_test(len - 1, &sk->sk_wmem_alloc));
1958 		sk->sk_write_space(sk);
1959 		len = 1;
1960 	}
1961 	/*
1962 	 * if sk_wmem_alloc reaches 0, we must finish what sk_free()
1963 	 * could not do because of in-flight packets
1964 	 */
1965 	if (refcount_sub_and_test(len, &sk->sk_wmem_alloc))
1966 		__sk_free(sk);
1967 }
1968 EXPORT_SYMBOL(sock_wfree);
1969 
1970 /* This variant of sock_wfree() is used by TCP,
1971  * since it sets SOCK_USE_WRITE_QUEUE.
1972  */
1973 void __sock_wfree(struct sk_buff *skb)
1974 {
1975 	struct sock *sk = skb->sk;
1976 
1977 	if (refcount_sub_and_test(skb->truesize, &sk->sk_wmem_alloc))
1978 		__sk_free(sk);
1979 }
1980 
1981 void skb_set_owner_w(struct sk_buff *skb, struct sock *sk)
1982 {
1983 	skb_orphan(skb);
1984 	skb->sk = sk;
1985 #ifdef CONFIG_INET
1986 	if (unlikely(!sk_fullsock(sk))) {
1987 		skb->destructor = sock_edemux;
1988 		sock_hold(sk);
1989 		return;
1990 	}
1991 #endif
1992 	skb->destructor = sock_wfree;
1993 	skb_set_hash_from_sk(skb, sk);
1994 	/*
1995 	 * We used to take a refcount on sk, but following operation
1996 	 * is enough to guarantee sk_free() wont free this sock until
1997 	 * all in-flight packets are completed
1998 	 */
1999 	refcount_add(skb->truesize, &sk->sk_wmem_alloc);
2000 }
2001 EXPORT_SYMBOL(skb_set_owner_w);
2002 
2003 static bool can_skb_orphan_partial(const struct sk_buff *skb)
2004 {
2005 #ifdef CONFIG_TLS_DEVICE
2006 	/* Drivers depend on in-order delivery for crypto offload,
2007 	 * partial orphan breaks out-of-order-OK logic.
2008 	 */
2009 	if (skb->decrypted)
2010 		return false;
2011 #endif
2012 	return (skb->destructor == sock_wfree ||
2013 		(IS_ENABLED(CONFIG_INET) && skb->destructor == tcp_wfree));
2014 }
2015 
2016 /* This helper is used by netem, as it can hold packets in its
2017  * delay queue. We want to allow the owner socket to send more
2018  * packets, as if they were already TX completed by a typical driver.
2019  * But we also want to keep skb->sk set because some packet schedulers
2020  * rely on it (sch_fq for example).
2021  */
2022 void skb_orphan_partial(struct sk_buff *skb)
2023 {
2024 	if (skb_is_tcp_pure_ack(skb))
2025 		return;
2026 
2027 	if (can_skb_orphan_partial(skb)) {
2028 		struct sock *sk = skb->sk;
2029 
2030 		if (refcount_inc_not_zero(&sk->sk_refcnt)) {
2031 			WARN_ON(refcount_sub_and_test(skb->truesize, &sk->sk_wmem_alloc));
2032 			skb->destructor = sock_efree;
2033 		}
2034 	} else {
2035 		skb_orphan(skb);
2036 	}
2037 }
2038 EXPORT_SYMBOL(skb_orphan_partial);
2039 
2040 /*
2041  * Read buffer destructor automatically called from kfree_skb.
2042  */
2043 void sock_rfree(struct sk_buff *skb)
2044 {
2045 	struct sock *sk = skb->sk;
2046 	unsigned int len = skb->truesize;
2047 
2048 	atomic_sub(len, &sk->sk_rmem_alloc);
2049 	sk_mem_uncharge(sk, len);
2050 }
2051 EXPORT_SYMBOL(sock_rfree);
2052 
2053 /*
2054  * Buffer destructor for skbs that are not used directly in read or write
2055  * path, e.g. for error handler skbs. Automatically called from kfree_skb.
2056  */
2057 void sock_efree(struct sk_buff *skb)
2058 {
2059 	sock_put(skb->sk);
2060 }
2061 EXPORT_SYMBOL(sock_efree);
2062 
2063 kuid_t sock_i_uid(struct sock *sk)
2064 {
2065 	kuid_t uid;
2066 
2067 	read_lock_bh(&sk->sk_callback_lock);
2068 	uid = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_uid : GLOBAL_ROOT_UID;
2069 	read_unlock_bh(&sk->sk_callback_lock);
2070 	return uid;
2071 }
2072 EXPORT_SYMBOL(sock_i_uid);
2073 
2074 unsigned long sock_i_ino(struct sock *sk)
2075 {
2076 	unsigned long ino;
2077 
2078 	read_lock_bh(&sk->sk_callback_lock);
2079 	ino = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_ino : 0;
2080 	read_unlock_bh(&sk->sk_callback_lock);
2081 	return ino;
2082 }
2083 EXPORT_SYMBOL(sock_i_ino);
2084 
2085 /*
2086  * Allocate a skb from the socket's send buffer.
2087  */
2088 struct sk_buff *sock_wmalloc(struct sock *sk, unsigned long size, int force,
2089 			     gfp_t priority)
2090 {
2091 	if (force || refcount_read(&sk->sk_wmem_alloc) < sk->sk_sndbuf) {
2092 		struct sk_buff *skb = alloc_skb(size, priority);
2093 		if (skb) {
2094 			skb_set_owner_w(skb, sk);
2095 			return skb;
2096 		}
2097 	}
2098 	return NULL;
2099 }
2100 EXPORT_SYMBOL(sock_wmalloc);
2101 
2102 static void sock_ofree(struct sk_buff *skb)
2103 {
2104 	struct sock *sk = skb->sk;
2105 
2106 	atomic_sub(skb->truesize, &sk->sk_omem_alloc);
2107 }
2108 
2109 struct sk_buff *sock_omalloc(struct sock *sk, unsigned long size,
2110 			     gfp_t priority)
2111 {
2112 	struct sk_buff *skb;
2113 
2114 	/* small safe race: SKB_TRUESIZE may differ from final skb->truesize */
2115 	if (atomic_read(&sk->sk_omem_alloc) + SKB_TRUESIZE(size) >
2116 	    sysctl_optmem_max)
2117 		return NULL;
2118 
2119 	skb = alloc_skb(size, priority);
2120 	if (!skb)
2121 		return NULL;
2122 
2123 	atomic_add(skb->truesize, &sk->sk_omem_alloc);
2124 	skb->sk = sk;
2125 	skb->destructor = sock_ofree;
2126 	return skb;
2127 }
2128 
2129 /*
2130  * Allocate a memory block from the socket's option memory buffer.
2131  */
2132 void *sock_kmalloc(struct sock *sk, int size, gfp_t priority)
2133 {
2134 	if ((unsigned int)size <= sysctl_optmem_max &&
2135 	    atomic_read(&sk->sk_omem_alloc) + size < sysctl_optmem_max) {
2136 		void *mem;
2137 		/* First do the add, to avoid the race if kmalloc
2138 		 * might sleep.
2139 		 */
2140 		atomic_add(size, &sk->sk_omem_alloc);
2141 		mem = kmalloc(size, priority);
2142 		if (mem)
2143 			return mem;
2144 		atomic_sub(size, &sk->sk_omem_alloc);
2145 	}
2146 	return NULL;
2147 }
2148 EXPORT_SYMBOL(sock_kmalloc);
2149 
2150 /* Free an option memory block. Note, we actually want the inline
2151  * here as this allows gcc to detect the nullify and fold away the
2152  * condition entirely.
2153  */
2154 static inline void __sock_kfree_s(struct sock *sk, void *mem, int size,
2155 				  const bool nullify)
2156 {
2157 	if (WARN_ON_ONCE(!mem))
2158 		return;
2159 	if (nullify)
2160 		kzfree(mem);
2161 	else
2162 		kfree(mem);
2163 	atomic_sub(size, &sk->sk_omem_alloc);
2164 }
2165 
2166 void sock_kfree_s(struct sock *sk, void *mem, int size)
2167 {
2168 	__sock_kfree_s(sk, mem, size, false);
2169 }
2170 EXPORT_SYMBOL(sock_kfree_s);
2171 
2172 void sock_kzfree_s(struct sock *sk, void *mem, int size)
2173 {
2174 	__sock_kfree_s(sk, mem, size, true);
2175 }
2176 EXPORT_SYMBOL(sock_kzfree_s);
2177 
2178 /* It is almost wait_for_tcp_memory minus release_sock/lock_sock.
2179    I think, these locks should be removed for datagram sockets.
2180  */
2181 static long sock_wait_for_wmem(struct sock *sk, long timeo)
2182 {
2183 	DEFINE_WAIT(wait);
2184 
2185 	sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
2186 	for (;;) {
2187 		if (!timeo)
2188 			break;
2189 		if (signal_pending(current))
2190 			break;
2191 		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
2192 		prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
2193 		if (refcount_read(&sk->sk_wmem_alloc) < sk->sk_sndbuf)
2194 			break;
2195 		if (sk->sk_shutdown & SEND_SHUTDOWN)
2196 			break;
2197 		if (sk->sk_err)
2198 			break;
2199 		timeo = schedule_timeout(timeo);
2200 	}
2201 	finish_wait(sk_sleep(sk), &wait);
2202 	return timeo;
2203 }
2204 
2205 
2206 /*
2207  *	Generic send/receive buffer handlers
2208  */
2209 
2210 struct sk_buff *sock_alloc_send_pskb(struct sock *sk, unsigned long header_len,
2211 				     unsigned long data_len, int noblock,
2212 				     int *errcode, int max_page_order)
2213 {
2214 	struct sk_buff *skb;
2215 	long timeo;
2216 	int err;
2217 
2218 	timeo = sock_sndtimeo(sk, noblock);
2219 	for (;;) {
2220 		err = sock_error(sk);
2221 		if (err != 0)
2222 			goto failure;
2223 
2224 		err = -EPIPE;
2225 		if (sk->sk_shutdown & SEND_SHUTDOWN)
2226 			goto failure;
2227 
2228 		if (sk_wmem_alloc_get(sk) < sk->sk_sndbuf)
2229 			break;
2230 
2231 		sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
2232 		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
2233 		err = -EAGAIN;
2234 		if (!timeo)
2235 			goto failure;
2236 		if (signal_pending(current))
2237 			goto interrupted;
2238 		timeo = sock_wait_for_wmem(sk, timeo);
2239 	}
2240 	skb = alloc_skb_with_frags(header_len, data_len, max_page_order,
2241 				   errcode, sk->sk_allocation);
2242 	if (skb)
2243 		skb_set_owner_w(skb, sk);
2244 	return skb;
2245 
2246 interrupted:
2247 	err = sock_intr_errno(timeo);
2248 failure:
2249 	*errcode = err;
2250 	return NULL;
2251 }
2252 EXPORT_SYMBOL(sock_alloc_send_pskb);
2253 
2254 struct sk_buff *sock_alloc_send_skb(struct sock *sk, unsigned long size,
2255 				    int noblock, int *errcode)
2256 {
2257 	return sock_alloc_send_pskb(sk, size, 0, noblock, errcode, 0);
2258 }
2259 EXPORT_SYMBOL(sock_alloc_send_skb);
2260 
2261 int __sock_cmsg_send(struct sock *sk, struct msghdr *msg, struct cmsghdr *cmsg,
2262 		     struct sockcm_cookie *sockc)
2263 {
2264 	u32 tsflags;
2265 
2266 	switch (cmsg->cmsg_type) {
2267 	case SO_MARK:
2268 		if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
2269 			return -EPERM;
2270 		if (cmsg->cmsg_len != CMSG_LEN(sizeof(u32)))
2271 			return -EINVAL;
2272 		sockc->mark = *(u32 *)CMSG_DATA(cmsg);
2273 		break;
2274 	case SO_TIMESTAMPING_OLD:
2275 		if (cmsg->cmsg_len != CMSG_LEN(sizeof(u32)))
2276 			return -EINVAL;
2277 
2278 		tsflags = *(u32 *)CMSG_DATA(cmsg);
2279 		if (tsflags & ~SOF_TIMESTAMPING_TX_RECORD_MASK)
2280 			return -EINVAL;
2281 
2282 		sockc->tsflags &= ~SOF_TIMESTAMPING_TX_RECORD_MASK;
2283 		sockc->tsflags |= tsflags;
2284 		break;
2285 	case SCM_TXTIME:
2286 		if (!sock_flag(sk, SOCK_TXTIME))
2287 			return -EINVAL;
2288 		if (cmsg->cmsg_len != CMSG_LEN(sizeof(u64)))
2289 			return -EINVAL;
2290 		sockc->transmit_time = get_unaligned((u64 *)CMSG_DATA(cmsg));
2291 		break;
2292 	/* SCM_RIGHTS and SCM_CREDENTIALS are semantically in SOL_UNIX. */
2293 	case SCM_RIGHTS:
2294 	case SCM_CREDENTIALS:
2295 		break;
2296 	default:
2297 		return -EINVAL;
2298 	}
2299 	return 0;
2300 }
2301 EXPORT_SYMBOL(__sock_cmsg_send);
2302 
2303 int sock_cmsg_send(struct sock *sk, struct msghdr *msg,
2304 		   struct sockcm_cookie *sockc)
2305 {
2306 	struct cmsghdr *cmsg;
2307 	int ret;
2308 
2309 	for_each_cmsghdr(cmsg, msg) {
2310 		if (!CMSG_OK(msg, cmsg))
2311 			return -EINVAL;
2312 		if (cmsg->cmsg_level != SOL_SOCKET)
2313 			continue;
2314 		ret = __sock_cmsg_send(sk, msg, cmsg, sockc);
2315 		if (ret)
2316 			return ret;
2317 	}
2318 	return 0;
2319 }
2320 EXPORT_SYMBOL(sock_cmsg_send);
2321 
2322 static void sk_enter_memory_pressure(struct sock *sk)
2323 {
2324 	if (!sk->sk_prot->enter_memory_pressure)
2325 		return;
2326 
2327 	sk->sk_prot->enter_memory_pressure(sk);
2328 }
2329 
2330 static void sk_leave_memory_pressure(struct sock *sk)
2331 {
2332 	if (sk->sk_prot->leave_memory_pressure) {
2333 		sk->sk_prot->leave_memory_pressure(sk);
2334 	} else {
2335 		unsigned long *memory_pressure = sk->sk_prot->memory_pressure;
2336 
2337 		if (memory_pressure && *memory_pressure)
2338 			*memory_pressure = 0;
2339 	}
2340 }
2341 
2342 /* On 32bit arches, an skb frag is limited to 2^15 */
2343 #define SKB_FRAG_PAGE_ORDER	get_order(32768)
2344 DEFINE_STATIC_KEY_FALSE(net_high_order_alloc_disable_key);
2345 
2346 /**
2347  * skb_page_frag_refill - check that a page_frag contains enough room
2348  * @sz: minimum size of the fragment we want to get
2349  * @pfrag: pointer to page_frag
2350  * @gfp: priority for memory allocation
2351  *
2352  * Note: While this allocator tries to use high order pages, there is
2353  * no guarantee that allocations succeed. Therefore, @sz MUST be
2354  * less or equal than PAGE_SIZE.
2355  */
2356 bool skb_page_frag_refill(unsigned int sz, struct page_frag *pfrag, gfp_t gfp)
2357 {
2358 	if (pfrag->page) {
2359 		if (page_ref_count(pfrag->page) == 1) {
2360 			pfrag->offset = 0;
2361 			return true;
2362 		}
2363 		if (pfrag->offset + sz <= pfrag->size)
2364 			return true;
2365 		put_page(pfrag->page);
2366 	}
2367 
2368 	pfrag->offset = 0;
2369 	if (SKB_FRAG_PAGE_ORDER &&
2370 	    !static_branch_unlikely(&net_high_order_alloc_disable_key)) {
2371 		/* Avoid direct reclaim but allow kswapd to wake */
2372 		pfrag->page = alloc_pages((gfp & ~__GFP_DIRECT_RECLAIM) |
2373 					  __GFP_COMP | __GFP_NOWARN |
2374 					  __GFP_NORETRY,
2375 					  SKB_FRAG_PAGE_ORDER);
2376 		if (likely(pfrag->page)) {
2377 			pfrag->size = PAGE_SIZE << SKB_FRAG_PAGE_ORDER;
2378 			return true;
2379 		}
2380 	}
2381 	pfrag->page = alloc_page(gfp);
2382 	if (likely(pfrag->page)) {
2383 		pfrag->size = PAGE_SIZE;
2384 		return true;
2385 	}
2386 	return false;
2387 }
2388 EXPORT_SYMBOL(skb_page_frag_refill);
2389 
2390 bool sk_page_frag_refill(struct sock *sk, struct page_frag *pfrag)
2391 {
2392 	if (likely(skb_page_frag_refill(32U, pfrag, sk->sk_allocation)))
2393 		return true;
2394 
2395 	sk_enter_memory_pressure(sk);
2396 	sk_stream_moderate_sndbuf(sk);
2397 	return false;
2398 }
2399 EXPORT_SYMBOL(sk_page_frag_refill);
2400 
2401 static void __lock_sock(struct sock *sk)
2402 	__releases(&sk->sk_lock.slock)
2403 	__acquires(&sk->sk_lock.slock)
2404 {
2405 	DEFINE_WAIT(wait);
2406 
2407 	for (;;) {
2408 		prepare_to_wait_exclusive(&sk->sk_lock.wq, &wait,
2409 					TASK_UNINTERRUPTIBLE);
2410 		spin_unlock_bh(&sk->sk_lock.slock);
2411 		schedule();
2412 		spin_lock_bh(&sk->sk_lock.slock);
2413 		if (!sock_owned_by_user(sk))
2414 			break;
2415 	}
2416 	finish_wait(&sk->sk_lock.wq, &wait);
2417 }
2418 
2419 void __release_sock(struct sock *sk)
2420 	__releases(&sk->sk_lock.slock)
2421 	__acquires(&sk->sk_lock.slock)
2422 {
2423 	struct sk_buff *skb, *next;
2424 
2425 	while ((skb = sk->sk_backlog.head) != NULL) {
2426 		sk->sk_backlog.head = sk->sk_backlog.tail = NULL;
2427 
2428 		spin_unlock_bh(&sk->sk_lock.slock);
2429 
2430 		do {
2431 			next = skb->next;
2432 			prefetch(next);
2433 			WARN_ON_ONCE(skb_dst_is_noref(skb));
2434 			skb_mark_not_on_list(skb);
2435 			sk_backlog_rcv(sk, skb);
2436 
2437 			cond_resched();
2438 
2439 			skb = next;
2440 		} while (skb != NULL);
2441 
2442 		spin_lock_bh(&sk->sk_lock.slock);
2443 	}
2444 
2445 	/*
2446 	 * Doing the zeroing here guarantee we can not loop forever
2447 	 * while a wild producer attempts to flood us.
2448 	 */
2449 	sk->sk_backlog.len = 0;
2450 }
2451 
2452 void __sk_flush_backlog(struct sock *sk)
2453 {
2454 	spin_lock_bh(&sk->sk_lock.slock);
2455 	__release_sock(sk);
2456 	spin_unlock_bh(&sk->sk_lock.slock);
2457 }
2458 
2459 /**
2460  * sk_wait_data - wait for data to arrive at sk_receive_queue
2461  * @sk:    sock to wait on
2462  * @timeo: for how long
2463  * @skb:   last skb seen on sk_receive_queue
2464  *
2465  * Now socket state including sk->sk_err is changed only under lock,
2466  * hence we may omit checks after joining wait queue.
2467  * We check receive queue before schedule() only as optimization;
2468  * it is very likely that release_sock() added new data.
2469  */
2470 int sk_wait_data(struct sock *sk, long *timeo, const struct sk_buff *skb)
2471 {
2472 	DEFINE_WAIT_FUNC(wait, woken_wake_function);
2473 	int rc;
2474 
2475 	add_wait_queue(sk_sleep(sk), &wait);
2476 	sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
2477 	rc = sk_wait_event(sk, timeo, skb_peek_tail(&sk->sk_receive_queue) != skb, &wait);
2478 	sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
2479 	remove_wait_queue(sk_sleep(sk), &wait);
2480 	return rc;
2481 }
2482 EXPORT_SYMBOL(sk_wait_data);
2483 
2484 /**
2485  *	__sk_mem_raise_allocated - increase memory_allocated
2486  *	@sk: socket
2487  *	@size: memory size to allocate
2488  *	@amt: pages to allocate
2489  *	@kind: allocation type
2490  *
2491  *	Similar to __sk_mem_schedule(), but does not update sk_forward_alloc
2492  */
2493 int __sk_mem_raise_allocated(struct sock *sk, int size, int amt, int kind)
2494 {
2495 	struct proto *prot = sk->sk_prot;
2496 	long allocated = sk_memory_allocated_add(sk, amt);
2497 	bool charged = true;
2498 
2499 	if (mem_cgroup_sockets_enabled && sk->sk_memcg &&
2500 	    !(charged = mem_cgroup_charge_skmem(sk->sk_memcg, amt)))
2501 		goto suppress_allocation;
2502 
2503 	/* Under limit. */
2504 	if (allocated <= sk_prot_mem_limits(sk, 0)) {
2505 		sk_leave_memory_pressure(sk);
2506 		return 1;
2507 	}
2508 
2509 	/* Under pressure. */
2510 	if (allocated > sk_prot_mem_limits(sk, 1))
2511 		sk_enter_memory_pressure(sk);
2512 
2513 	/* Over hard limit. */
2514 	if (allocated > sk_prot_mem_limits(sk, 2))
2515 		goto suppress_allocation;
2516 
2517 	/* guarantee minimum buffer size under pressure */
2518 	if (kind == SK_MEM_RECV) {
2519 		if (atomic_read(&sk->sk_rmem_alloc) < sk_get_rmem0(sk, prot))
2520 			return 1;
2521 
2522 	} else { /* SK_MEM_SEND */
2523 		int wmem0 = sk_get_wmem0(sk, prot);
2524 
2525 		if (sk->sk_type == SOCK_STREAM) {
2526 			if (sk->sk_wmem_queued < wmem0)
2527 				return 1;
2528 		} else if (refcount_read(&sk->sk_wmem_alloc) < wmem0) {
2529 				return 1;
2530 		}
2531 	}
2532 
2533 	if (sk_has_memory_pressure(sk)) {
2534 		u64 alloc;
2535 
2536 		if (!sk_under_memory_pressure(sk))
2537 			return 1;
2538 		alloc = sk_sockets_allocated_read_positive(sk);
2539 		if (sk_prot_mem_limits(sk, 2) > alloc *
2540 		    sk_mem_pages(sk->sk_wmem_queued +
2541 				 atomic_read(&sk->sk_rmem_alloc) +
2542 				 sk->sk_forward_alloc))
2543 			return 1;
2544 	}
2545 
2546 suppress_allocation:
2547 
2548 	if (kind == SK_MEM_SEND && sk->sk_type == SOCK_STREAM) {
2549 		sk_stream_moderate_sndbuf(sk);
2550 
2551 		/* Fail only if socket is _under_ its sndbuf.
2552 		 * In this case we cannot block, so that we have to fail.
2553 		 */
2554 		if (sk->sk_wmem_queued + size >= sk->sk_sndbuf)
2555 			return 1;
2556 	}
2557 
2558 	if (kind == SK_MEM_SEND || (kind == SK_MEM_RECV && charged))
2559 		trace_sock_exceed_buf_limit(sk, prot, allocated, kind);
2560 
2561 	sk_memory_allocated_sub(sk, amt);
2562 
2563 	if (mem_cgroup_sockets_enabled && sk->sk_memcg)
2564 		mem_cgroup_uncharge_skmem(sk->sk_memcg, amt);
2565 
2566 	return 0;
2567 }
2568 EXPORT_SYMBOL(__sk_mem_raise_allocated);
2569 
2570 /**
2571  *	__sk_mem_schedule - increase sk_forward_alloc and memory_allocated
2572  *	@sk: socket
2573  *	@size: memory size to allocate
2574  *	@kind: allocation type
2575  *
2576  *	If kind is SK_MEM_SEND, it means wmem allocation. Otherwise it means
2577  *	rmem allocation. This function assumes that protocols which have
2578  *	memory_pressure use sk_wmem_queued as write buffer accounting.
2579  */
2580 int __sk_mem_schedule(struct sock *sk, int size, int kind)
2581 {
2582 	int ret, amt = sk_mem_pages(size);
2583 
2584 	sk->sk_forward_alloc += amt << SK_MEM_QUANTUM_SHIFT;
2585 	ret = __sk_mem_raise_allocated(sk, size, amt, kind);
2586 	if (!ret)
2587 		sk->sk_forward_alloc -= amt << SK_MEM_QUANTUM_SHIFT;
2588 	return ret;
2589 }
2590 EXPORT_SYMBOL(__sk_mem_schedule);
2591 
2592 /**
2593  *	__sk_mem_reduce_allocated - reclaim memory_allocated
2594  *	@sk: socket
2595  *	@amount: number of quanta
2596  *
2597  *	Similar to __sk_mem_reclaim(), but does not update sk_forward_alloc
2598  */
2599 void __sk_mem_reduce_allocated(struct sock *sk, int amount)
2600 {
2601 	sk_memory_allocated_sub(sk, amount);
2602 
2603 	if (mem_cgroup_sockets_enabled && sk->sk_memcg)
2604 		mem_cgroup_uncharge_skmem(sk->sk_memcg, amount);
2605 
2606 	if (sk_under_memory_pressure(sk) &&
2607 	    (sk_memory_allocated(sk) < sk_prot_mem_limits(sk, 0)))
2608 		sk_leave_memory_pressure(sk);
2609 }
2610 EXPORT_SYMBOL(__sk_mem_reduce_allocated);
2611 
2612 /**
2613  *	__sk_mem_reclaim - reclaim sk_forward_alloc and memory_allocated
2614  *	@sk: socket
2615  *	@amount: number of bytes (rounded down to a SK_MEM_QUANTUM multiple)
2616  */
2617 void __sk_mem_reclaim(struct sock *sk, int amount)
2618 {
2619 	amount >>= SK_MEM_QUANTUM_SHIFT;
2620 	sk->sk_forward_alloc -= amount << SK_MEM_QUANTUM_SHIFT;
2621 	__sk_mem_reduce_allocated(sk, amount);
2622 }
2623 EXPORT_SYMBOL(__sk_mem_reclaim);
2624 
2625 int sk_set_peek_off(struct sock *sk, int val)
2626 {
2627 	sk->sk_peek_off = val;
2628 	return 0;
2629 }
2630 EXPORT_SYMBOL_GPL(sk_set_peek_off);
2631 
2632 /*
2633  * Set of default routines for initialising struct proto_ops when
2634  * the protocol does not support a particular function. In certain
2635  * cases where it makes no sense for a protocol to have a "do nothing"
2636  * function, some default processing is provided.
2637  */
2638 
2639 int sock_no_bind(struct socket *sock, struct sockaddr *saddr, int len)
2640 {
2641 	return -EOPNOTSUPP;
2642 }
2643 EXPORT_SYMBOL(sock_no_bind);
2644 
2645 int sock_no_connect(struct socket *sock, struct sockaddr *saddr,
2646 		    int len, int flags)
2647 {
2648 	return -EOPNOTSUPP;
2649 }
2650 EXPORT_SYMBOL(sock_no_connect);
2651 
2652 int sock_no_socketpair(struct socket *sock1, struct socket *sock2)
2653 {
2654 	return -EOPNOTSUPP;
2655 }
2656 EXPORT_SYMBOL(sock_no_socketpair);
2657 
2658 int sock_no_accept(struct socket *sock, struct socket *newsock, int flags,
2659 		   bool kern)
2660 {
2661 	return -EOPNOTSUPP;
2662 }
2663 EXPORT_SYMBOL(sock_no_accept);
2664 
2665 int sock_no_getname(struct socket *sock, struct sockaddr *saddr,
2666 		    int peer)
2667 {
2668 	return -EOPNOTSUPP;
2669 }
2670 EXPORT_SYMBOL(sock_no_getname);
2671 
2672 int sock_no_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
2673 {
2674 	return -EOPNOTSUPP;
2675 }
2676 EXPORT_SYMBOL(sock_no_ioctl);
2677 
2678 int sock_no_listen(struct socket *sock, int backlog)
2679 {
2680 	return -EOPNOTSUPP;
2681 }
2682 EXPORT_SYMBOL(sock_no_listen);
2683 
2684 int sock_no_shutdown(struct socket *sock, int how)
2685 {
2686 	return -EOPNOTSUPP;
2687 }
2688 EXPORT_SYMBOL(sock_no_shutdown);
2689 
2690 int sock_no_setsockopt(struct socket *sock, int level, int optname,
2691 		    char __user *optval, unsigned int optlen)
2692 {
2693 	return -EOPNOTSUPP;
2694 }
2695 EXPORT_SYMBOL(sock_no_setsockopt);
2696 
2697 int sock_no_getsockopt(struct socket *sock, int level, int optname,
2698 		    char __user *optval, int __user *optlen)
2699 {
2700 	return -EOPNOTSUPP;
2701 }
2702 EXPORT_SYMBOL(sock_no_getsockopt);
2703 
2704 int sock_no_sendmsg(struct socket *sock, struct msghdr *m, size_t len)
2705 {
2706 	return -EOPNOTSUPP;
2707 }
2708 EXPORT_SYMBOL(sock_no_sendmsg);
2709 
2710 int sock_no_sendmsg_locked(struct sock *sk, struct msghdr *m, size_t len)
2711 {
2712 	return -EOPNOTSUPP;
2713 }
2714 EXPORT_SYMBOL(sock_no_sendmsg_locked);
2715 
2716 int sock_no_recvmsg(struct socket *sock, struct msghdr *m, size_t len,
2717 		    int flags)
2718 {
2719 	return -EOPNOTSUPP;
2720 }
2721 EXPORT_SYMBOL(sock_no_recvmsg);
2722 
2723 int sock_no_mmap(struct file *file, struct socket *sock, struct vm_area_struct *vma)
2724 {
2725 	/* Mirror missing mmap method error code */
2726 	return -ENODEV;
2727 }
2728 EXPORT_SYMBOL(sock_no_mmap);
2729 
2730 ssize_t sock_no_sendpage(struct socket *sock, struct page *page, int offset, size_t size, int flags)
2731 {
2732 	ssize_t res;
2733 	struct msghdr msg = {.msg_flags = flags};
2734 	struct kvec iov;
2735 	char *kaddr = kmap(page);
2736 	iov.iov_base = kaddr + offset;
2737 	iov.iov_len = size;
2738 	res = kernel_sendmsg(sock, &msg, &iov, 1, size);
2739 	kunmap(page);
2740 	return res;
2741 }
2742 EXPORT_SYMBOL(sock_no_sendpage);
2743 
2744 ssize_t sock_no_sendpage_locked(struct sock *sk, struct page *page,
2745 				int offset, size_t size, int flags)
2746 {
2747 	ssize_t res;
2748 	struct msghdr msg = {.msg_flags = flags};
2749 	struct kvec iov;
2750 	char *kaddr = kmap(page);
2751 
2752 	iov.iov_base = kaddr + offset;
2753 	iov.iov_len = size;
2754 	res = kernel_sendmsg_locked(sk, &msg, &iov, 1, size);
2755 	kunmap(page);
2756 	return res;
2757 }
2758 EXPORT_SYMBOL(sock_no_sendpage_locked);
2759 
2760 /*
2761  *	Default Socket Callbacks
2762  */
2763 
2764 static void sock_def_wakeup(struct sock *sk)
2765 {
2766 	struct socket_wq *wq;
2767 
2768 	rcu_read_lock();
2769 	wq = rcu_dereference(sk->sk_wq);
2770 	if (skwq_has_sleeper(wq))
2771 		wake_up_interruptible_all(&wq->wait);
2772 	rcu_read_unlock();
2773 }
2774 
2775 static void sock_def_error_report(struct sock *sk)
2776 {
2777 	struct socket_wq *wq;
2778 
2779 	rcu_read_lock();
2780 	wq = rcu_dereference(sk->sk_wq);
2781 	if (skwq_has_sleeper(wq))
2782 		wake_up_interruptible_poll(&wq->wait, EPOLLERR);
2783 	sk_wake_async(sk, SOCK_WAKE_IO, POLL_ERR);
2784 	rcu_read_unlock();
2785 }
2786 
2787 static void sock_def_readable(struct sock *sk)
2788 {
2789 	struct socket_wq *wq;
2790 
2791 	rcu_read_lock();
2792 	wq = rcu_dereference(sk->sk_wq);
2793 	if (skwq_has_sleeper(wq))
2794 		wake_up_interruptible_sync_poll(&wq->wait, EPOLLIN | EPOLLPRI |
2795 						EPOLLRDNORM | EPOLLRDBAND);
2796 	sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
2797 	rcu_read_unlock();
2798 }
2799 
2800 static void sock_def_write_space(struct sock *sk)
2801 {
2802 	struct socket_wq *wq;
2803 
2804 	rcu_read_lock();
2805 
2806 	/* Do not wake up a writer until he can make "significant"
2807 	 * progress.  --DaveM
2808 	 */
2809 	if ((refcount_read(&sk->sk_wmem_alloc) << 1) <= sk->sk_sndbuf) {
2810 		wq = rcu_dereference(sk->sk_wq);
2811 		if (skwq_has_sleeper(wq))
2812 			wake_up_interruptible_sync_poll(&wq->wait, EPOLLOUT |
2813 						EPOLLWRNORM | EPOLLWRBAND);
2814 
2815 		/* Should agree with poll, otherwise some programs break */
2816 		if (sock_writeable(sk))
2817 			sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
2818 	}
2819 
2820 	rcu_read_unlock();
2821 }
2822 
2823 static void sock_def_destruct(struct sock *sk)
2824 {
2825 }
2826 
2827 void sk_send_sigurg(struct sock *sk)
2828 {
2829 	if (sk->sk_socket && sk->sk_socket->file)
2830 		if (send_sigurg(&sk->sk_socket->file->f_owner))
2831 			sk_wake_async(sk, SOCK_WAKE_URG, POLL_PRI);
2832 }
2833 EXPORT_SYMBOL(sk_send_sigurg);
2834 
2835 void sk_reset_timer(struct sock *sk, struct timer_list* timer,
2836 		    unsigned long expires)
2837 {
2838 	if (!mod_timer(timer, expires))
2839 		sock_hold(sk);
2840 }
2841 EXPORT_SYMBOL(sk_reset_timer);
2842 
2843 void sk_stop_timer(struct sock *sk, struct timer_list* timer)
2844 {
2845 	if (del_timer(timer))
2846 		__sock_put(sk);
2847 }
2848 EXPORT_SYMBOL(sk_stop_timer);
2849 
2850 void sock_init_data(struct socket *sock, struct sock *sk)
2851 {
2852 	sk_init_common(sk);
2853 	sk->sk_send_head	=	NULL;
2854 
2855 	timer_setup(&sk->sk_timer, NULL, 0);
2856 
2857 	sk->sk_allocation	=	GFP_KERNEL;
2858 	sk->sk_rcvbuf		=	sysctl_rmem_default;
2859 	sk->sk_sndbuf		=	sysctl_wmem_default;
2860 	sk->sk_state		=	TCP_CLOSE;
2861 	sk_set_socket(sk, sock);
2862 
2863 	sock_set_flag(sk, SOCK_ZAPPED);
2864 
2865 	if (sock) {
2866 		sk->sk_type	=	sock->type;
2867 		RCU_INIT_POINTER(sk->sk_wq, &sock->wq);
2868 		sock->sk	=	sk;
2869 		sk->sk_uid	=	SOCK_INODE(sock)->i_uid;
2870 	} else {
2871 		RCU_INIT_POINTER(sk->sk_wq, NULL);
2872 		sk->sk_uid	=	make_kuid(sock_net(sk)->user_ns, 0);
2873 	}
2874 
2875 	rwlock_init(&sk->sk_callback_lock);
2876 	if (sk->sk_kern_sock)
2877 		lockdep_set_class_and_name(
2878 			&sk->sk_callback_lock,
2879 			af_kern_callback_keys + sk->sk_family,
2880 			af_family_kern_clock_key_strings[sk->sk_family]);
2881 	else
2882 		lockdep_set_class_and_name(
2883 			&sk->sk_callback_lock,
2884 			af_callback_keys + sk->sk_family,
2885 			af_family_clock_key_strings[sk->sk_family]);
2886 
2887 	sk->sk_state_change	=	sock_def_wakeup;
2888 	sk->sk_data_ready	=	sock_def_readable;
2889 	sk->sk_write_space	=	sock_def_write_space;
2890 	sk->sk_error_report	=	sock_def_error_report;
2891 	sk->sk_destruct		=	sock_def_destruct;
2892 
2893 	sk->sk_frag.page	=	NULL;
2894 	sk->sk_frag.offset	=	0;
2895 	sk->sk_peek_off		=	-1;
2896 
2897 	sk->sk_peer_pid 	=	NULL;
2898 	sk->sk_peer_cred	=	NULL;
2899 	sk->sk_write_pending	=	0;
2900 	sk->sk_rcvlowat		=	1;
2901 	sk->sk_rcvtimeo		=	MAX_SCHEDULE_TIMEOUT;
2902 	sk->sk_sndtimeo		=	MAX_SCHEDULE_TIMEOUT;
2903 
2904 	sk->sk_stamp = SK_DEFAULT_STAMP;
2905 #if BITS_PER_LONG==32
2906 	seqlock_init(&sk->sk_stamp_seq);
2907 #endif
2908 	atomic_set(&sk->sk_zckey, 0);
2909 
2910 #ifdef CONFIG_NET_RX_BUSY_POLL
2911 	sk->sk_napi_id		=	0;
2912 	sk->sk_ll_usec		=	sysctl_net_busy_read;
2913 #endif
2914 
2915 	sk->sk_max_pacing_rate = ~0UL;
2916 	sk->sk_pacing_rate = ~0UL;
2917 	sk->sk_pacing_shift = 10;
2918 	sk->sk_incoming_cpu = -1;
2919 
2920 	sk_rx_queue_clear(sk);
2921 	/*
2922 	 * Before updating sk_refcnt, we must commit prior changes to memory
2923 	 * (Documentation/RCU/rculist_nulls.txt for details)
2924 	 */
2925 	smp_wmb();
2926 	refcount_set(&sk->sk_refcnt, 1);
2927 	atomic_set(&sk->sk_drops, 0);
2928 }
2929 EXPORT_SYMBOL(sock_init_data);
2930 
2931 void lock_sock_nested(struct sock *sk, int subclass)
2932 {
2933 	might_sleep();
2934 	spin_lock_bh(&sk->sk_lock.slock);
2935 	if (sk->sk_lock.owned)
2936 		__lock_sock(sk);
2937 	sk->sk_lock.owned = 1;
2938 	spin_unlock(&sk->sk_lock.slock);
2939 	/*
2940 	 * The sk_lock has mutex_lock() semantics here:
2941 	 */
2942 	mutex_acquire(&sk->sk_lock.dep_map, subclass, 0, _RET_IP_);
2943 	local_bh_enable();
2944 }
2945 EXPORT_SYMBOL(lock_sock_nested);
2946 
2947 void release_sock(struct sock *sk)
2948 {
2949 	spin_lock_bh(&sk->sk_lock.slock);
2950 	if (sk->sk_backlog.tail)
2951 		__release_sock(sk);
2952 
2953 	/* Warning : release_cb() might need to release sk ownership,
2954 	 * ie call sock_release_ownership(sk) before us.
2955 	 */
2956 	if (sk->sk_prot->release_cb)
2957 		sk->sk_prot->release_cb(sk);
2958 
2959 	sock_release_ownership(sk);
2960 	if (waitqueue_active(&sk->sk_lock.wq))
2961 		wake_up(&sk->sk_lock.wq);
2962 	spin_unlock_bh(&sk->sk_lock.slock);
2963 }
2964 EXPORT_SYMBOL(release_sock);
2965 
2966 /**
2967  * lock_sock_fast - fast version of lock_sock
2968  * @sk: socket
2969  *
2970  * This version should be used for very small section, where process wont block
2971  * return false if fast path is taken:
2972  *
2973  *   sk_lock.slock locked, owned = 0, BH disabled
2974  *
2975  * return true if slow path is taken:
2976  *
2977  *   sk_lock.slock unlocked, owned = 1, BH enabled
2978  */
2979 bool lock_sock_fast(struct sock *sk)
2980 {
2981 	might_sleep();
2982 	spin_lock_bh(&sk->sk_lock.slock);
2983 
2984 	if (!sk->sk_lock.owned)
2985 		/*
2986 		 * Note : We must disable BH
2987 		 */
2988 		return false;
2989 
2990 	__lock_sock(sk);
2991 	sk->sk_lock.owned = 1;
2992 	spin_unlock(&sk->sk_lock.slock);
2993 	/*
2994 	 * The sk_lock has mutex_lock() semantics here:
2995 	 */
2996 	mutex_acquire(&sk->sk_lock.dep_map, 0, 0, _RET_IP_);
2997 	local_bh_enable();
2998 	return true;
2999 }
3000 EXPORT_SYMBOL(lock_sock_fast);
3001 
3002 int sock_gettstamp(struct socket *sock, void __user *userstamp,
3003 		   bool timeval, bool time32)
3004 {
3005 	struct sock *sk = sock->sk;
3006 	struct timespec64 ts;
3007 
3008 	sock_enable_timestamp(sk, SOCK_TIMESTAMP);
3009 	ts = ktime_to_timespec64(sock_read_timestamp(sk));
3010 	if (ts.tv_sec == -1)
3011 		return -ENOENT;
3012 	if (ts.tv_sec == 0) {
3013 		ktime_t kt = ktime_get_real();
3014 		sock_write_timestamp(sk, kt);;
3015 		ts = ktime_to_timespec64(kt);
3016 	}
3017 
3018 	if (timeval)
3019 		ts.tv_nsec /= 1000;
3020 
3021 #ifdef CONFIG_COMPAT_32BIT_TIME
3022 	if (time32)
3023 		return put_old_timespec32(&ts, userstamp);
3024 #endif
3025 #ifdef CONFIG_SPARC64
3026 	/* beware of padding in sparc64 timeval */
3027 	if (timeval && !in_compat_syscall()) {
3028 		struct __kernel_old_timeval __user tv = {
3029 			.tv_sec = ts.tv_sec,
3030 			.tv_usec = ts.tv_nsec,
3031 		};
3032 		if (copy_to_user(userstamp, &tv, sizeof(tv)))
3033 			return -EFAULT;
3034 		return 0;
3035 	}
3036 #endif
3037 	return put_timespec64(&ts, userstamp);
3038 }
3039 EXPORT_SYMBOL(sock_gettstamp);
3040 
3041 void sock_enable_timestamp(struct sock *sk, int flag)
3042 {
3043 	if (!sock_flag(sk, flag)) {
3044 		unsigned long previous_flags = sk->sk_flags;
3045 
3046 		sock_set_flag(sk, flag);
3047 		/*
3048 		 * we just set one of the two flags which require net
3049 		 * time stamping, but time stamping might have been on
3050 		 * already because of the other one
3051 		 */
3052 		if (sock_needs_netstamp(sk) &&
3053 		    !(previous_flags & SK_FLAGS_TIMESTAMP))
3054 			net_enable_timestamp();
3055 	}
3056 }
3057 
3058 int sock_recv_errqueue(struct sock *sk, struct msghdr *msg, int len,
3059 		       int level, int type)
3060 {
3061 	struct sock_exterr_skb *serr;
3062 	struct sk_buff *skb;
3063 	int copied, err;
3064 
3065 	err = -EAGAIN;
3066 	skb = sock_dequeue_err_skb(sk);
3067 	if (skb == NULL)
3068 		goto out;
3069 
3070 	copied = skb->len;
3071 	if (copied > len) {
3072 		msg->msg_flags |= MSG_TRUNC;
3073 		copied = len;
3074 	}
3075 	err = skb_copy_datagram_msg(skb, 0, msg, copied);
3076 	if (err)
3077 		goto out_free_skb;
3078 
3079 	sock_recv_timestamp(msg, sk, skb);
3080 
3081 	serr = SKB_EXT_ERR(skb);
3082 	put_cmsg(msg, level, type, sizeof(serr->ee), &serr->ee);
3083 
3084 	msg->msg_flags |= MSG_ERRQUEUE;
3085 	err = copied;
3086 
3087 out_free_skb:
3088 	kfree_skb(skb);
3089 out:
3090 	return err;
3091 }
3092 EXPORT_SYMBOL(sock_recv_errqueue);
3093 
3094 /*
3095  *	Get a socket option on an socket.
3096  *
3097  *	FIX: POSIX 1003.1g is very ambiguous here. It states that
3098  *	asynchronous errors should be reported by getsockopt. We assume
3099  *	this means if you specify SO_ERROR (otherwise whats the point of it).
3100  */
3101 int sock_common_getsockopt(struct socket *sock, int level, int optname,
3102 			   char __user *optval, int __user *optlen)
3103 {
3104 	struct sock *sk = sock->sk;
3105 
3106 	return sk->sk_prot->getsockopt(sk, level, optname, optval, optlen);
3107 }
3108 EXPORT_SYMBOL(sock_common_getsockopt);
3109 
3110 #ifdef CONFIG_COMPAT
3111 int compat_sock_common_getsockopt(struct socket *sock, int level, int optname,
3112 				  char __user *optval, int __user *optlen)
3113 {
3114 	struct sock *sk = sock->sk;
3115 
3116 	if (sk->sk_prot->compat_getsockopt != NULL)
3117 		return sk->sk_prot->compat_getsockopt(sk, level, optname,
3118 						      optval, optlen);
3119 	return sk->sk_prot->getsockopt(sk, level, optname, optval, optlen);
3120 }
3121 EXPORT_SYMBOL(compat_sock_common_getsockopt);
3122 #endif
3123 
3124 int sock_common_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
3125 			int flags)
3126 {
3127 	struct sock *sk = sock->sk;
3128 	int addr_len = 0;
3129 	int err;
3130 
3131 	err = sk->sk_prot->recvmsg(sk, msg, size, flags & MSG_DONTWAIT,
3132 				   flags & ~MSG_DONTWAIT, &addr_len);
3133 	if (err >= 0)
3134 		msg->msg_namelen = addr_len;
3135 	return err;
3136 }
3137 EXPORT_SYMBOL(sock_common_recvmsg);
3138 
3139 /*
3140  *	Set socket options on an inet socket.
3141  */
3142 int sock_common_setsockopt(struct socket *sock, int level, int optname,
3143 			   char __user *optval, unsigned int optlen)
3144 {
3145 	struct sock *sk = sock->sk;
3146 
3147 	return sk->sk_prot->setsockopt(sk, level, optname, optval, optlen);
3148 }
3149 EXPORT_SYMBOL(sock_common_setsockopt);
3150 
3151 #ifdef CONFIG_COMPAT
3152 int compat_sock_common_setsockopt(struct socket *sock, int level, int optname,
3153 				  char __user *optval, unsigned int optlen)
3154 {
3155 	struct sock *sk = sock->sk;
3156 
3157 	if (sk->sk_prot->compat_setsockopt != NULL)
3158 		return sk->sk_prot->compat_setsockopt(sk, level, optname,
3159 						      optval, optlen);
3160 	return sk->sk_prot->setsockopt(sk, level, optname, optval, optlen);
3161 }
3162 EXPORT_SYMBOL(compat_sock_common_setsockopt);
3163 #endif
3164 
3165 void sk_common_release(struct sock *sk)
3166 {
3167 	if (sk->sk_prot->destroy)
3168 		sk->sk_prot->destroy(sk);
3169 
3170 	/*
3171 	 * Observation: when sock_common_release is called, processes have
3172 	 * no access to socket. But net still has.
3173 	 * Step one, detach it from networking:
3174 	 *
3175 	 * A. Remove from hash tables.
3176 	 */
3177 
3178 	sk->sk_prot->unhash(sk);
3179 
3180 	/*
3181 	 * In this point socket cannot receive new packets, but it is possible
3182 	 * that some packets are in flight because some CPU runs receiver and
3183 	 * did hash table lookup before we unhashed socket. They will achieve
3184 	 * receive queue and will be purged by socket destructor.
3185 	 *
3186 	 * Also we still have packets pending on receive queue and probably,
3187 	 * our own packets waiting in device queues. sock_destroy will drain
3188 	 * receive queue, but transmitted packets will delay socket destruction
3189 	 * until the last reference will be released.
3190 	 */
3191 
3192 	sock_orphan(sk);
3193 
3194 	xfrm_sk_free_policy(sk);
3195 
3196 	sk_refcnt_debug_release(sk);
3197 
3198 	sock_put(sk);
3199 }
3200 EXPORT_SYMBOL(sk_common_release);
3201 
3202 void sk_get_meminfo(const struct sock *sk, u32 *mem)
3203 {
3204 	memset(mem, 0, sizeof(*mem) * SK_MEMINFO_VARS);
3205 
3206 	mem[SK_MEMINFO_RMEM_ALLOC] = sk_rmem_alloc_get(sk);
3207 	mem[SK_MEMINFO_RCVBUF] = sk->sk_rcvbuf;
3208 	mem[SK_MEMINFO_WMEM_ALLOC] = sk_wmem_alloc_get(sk);
3209 	mem[SK_MEMINFO_SNDBUF] = sk->sk_sndbuf;
3210 	mem[SK_MEMINFO_FWD_ALLOC] = sk->sk_forward_alloc;
3211 	mem[SK_MEMINFO_WMEM_QUEUED] = sk->sk_wmem_queued;
3212 	mem[SK_MEMINFO_OPTMEM] = atomic_read(&sk->sk_omem_alloc);
3213 	mem[SK_MEMINFO_BACKLOG] = sk->sk_backlog.len;
3214 	mem[SK_MEMINFO_DROPS] = atomic_read(&sk->sk_drops);
3215 }
3216 
3217 #ifdef CONFIG_PROC_FS
3218 #define PROTO_INUSE_NR	64	/* should be enough for the first time */
3219 struct prot_inuse {
3220 	int val[PROTO_INUSE_NR];
3221 };
3222 
3223 static DECLARE_BITMAP(proto_inuse_idx, PROTO_INUSE_NR);
3224 
3225 void sock_prot_inuse_add(struct net *net, struct proto *prot, int val)
3226 {
3227 	__this_cpu_add(net->core.prot_inuse->val[prot->inuse_idx], val);
3228 }
3229 EXPORT_SYMBOL_GPL(sock_prot_inuse_add);
3230 
3231 int sock_prot_inuse_get(struct net *net, struct proto *prot)
3232 {
3233 	int cpu, idx = prot->inuse_idx;
3234 	int res = 0;
3235 
3236 	for_each_possible_cpu(cpu)
3237 		res += per_cpu_ptr(net->core.prot_inuse, cpu)->val[idx];
3238 
3239 	return res >= 0 ? res : 0;
3240 }
3241 EXPORT_SYMBOL_GPL(sock_prot_inuse_get);
3242 
3243 static void sock_inuse_add(struct net *net, int val)
3244 {
3245 	this_cpu_add(*net->core.sock_inuse, val);
3246 }
3247 
3248 int sock_inuse_get(struct net *net)
3249 {
3250 	int cpu, res = 0;
3251 
3252 	for_each_possible_cpu(cpu)
3253 		res += *per_cpu_ptr(net->core.sock_inuse, cpu);
3254 
3255 	return res;
3256 }
3257 
3258 EXPORT_SYMBOL_GPL(sock_inuse_get);
3259 
3260 static int __net_init sock_inuse_init_net(struct net *net)
3261 {
3262 	net->core.prot_inuse = alloc_percpu(struct prot_inuse);
3263 	if (net->core.prot_inuse == NULL)
3264 		return -ENOMEM;
3265 
3266 	net->core.sock_inuse = alloc_percpu(int);
3267 	if (net->core.sock_inuse == NULL)
3268 		goto out;
3269 
3270 	return 0;
3271 
3272 out:
3273 	free_percpu(net->core.prot_inuse);
3274 	return -ENOMEM;
3275 }
3276 
3277 static void __net_exit sock_inuse_exit_net(struct net *net)
3278 {
3279 	free_percpu(net->core.prot_inuse);
3280 	free_percpu(net->core.sock_inuse);
3281 }
3282 
3283 static struct pernet_operations net_inuse_ops = {
3284 	.init = sock_inuse_init_net,
3285 	.exit = sock_inuse_exit_net,
3286 };
3287 
3288 static __init int net_inuse_init(void)
3289 {
3290 	if (register_pernet_subsys(&net_inuse_ops))
3291 		panic("Cannot initialize net inuse counters");
3292 
3293 	return 0;
3294 }
3295 
3296 core_initcall(net_inuse_init);
3297 
3298 static int assign_proto_idx(struct proto *prot)
3299 {
3300 	prot->inuse_idx = find_first_zero_bit(proto_inuse_idx, PROTO_INUSE_NR);
3301 
3302 	if (unlikely(prot->inuse_idx == PROTO_INUSE_NR - 1)) {
3303 		pr_err("PROTO_INUSE_NR exhausted\n");
3304 		return -ENOSPC;
3305 	}
3306 
3307 	set_bit(prot->inuse_idx, proto_inuse_idx);
3308 	return 0;
3309 }
3310 
3311 static void release_proto_idx(struct proto *prot)
3312 {
3313 	if (prot->inuse_idx != PROTO_INUSE_NR - 1)
3314 		clear_bit(prot->inuse_idx, proto_inuse_idx);
3315 }
3316 #else
3317 static inline int assign_proto_idx(struct proto *prot)
3318 {
3319 	return 0;
3320 }
3321 
3322 static inline void release_proto_idx(struct proto *prot)
3323 {
3324 }
3325 
3326 static void sock_inuse_add(struct net *net, int val)
3327 {
3328 }
3329 #endif
3330 
3331 static void req_prot_cleanup(struct request_sock_ops *rsk_prot)
3332 {
3333 	if (!rsk_prot)
3334 		return;
3335 	kfree(rsk_prot->slab_name);
3336 	rsk_prot->slab_name = NULL;
3337 	kmem_cache_destroy(rsk_prot->slab);
3338 	rsk_prot->slab = NULL;
3339 }
3340 
3341 static int req_prot_init(const struct proto *prot)
3342 {
3343 	struct request_sock_ops *rsk_prot = prot->rsk_prot;
3344 
3345 	if (!rsk_prot)
3346 		return 0;
3347 
3348 	rsk_prot->slab_name = kasprintf(GFP_KERNEL, "request_sock_%s",
3349 					prot->name);
3350 	if (!rsk_prot->slab_name)
3351 		return -ENOMEM;
3352 
3353 	rsk_prot->slab = kmem_cache_create(rsk_prot->slab_name,
3354 					   rsk_prot->obj_size, 0,
3355 					   SLAB_ACCOUNT | prot->slab_flags,
3356 					   NULL);
3357 
3358 	if (!rsk_prot->slab) {
3359 		pr_crit("%s: Can't create request sock SLAB cache!\n",
3360 			prot->name);
3361 		return -ENOMEM;
3362 	}
3363 	return 0;
3364 }
3365 
3366 int proto_register(struct proto *prot, int alloc_slab)
3367 {
3368 	int ret = -ENOBUFS;
3369 
3370 	if (alloc_slab) {
3371 		prot->slab = kmem_cache_create_usercopy(prot->name,
3372 					prot->obj_size, 0,
3373 					SLAB_HWCACHE_ALIGN | SLAB_ACCOUNT |
3374 					prot->slab_flags,
3375 					prot->useroffset, prot->usersize,
3376 					NULL);
3377 
3378 		if (prot->slab == NULL) {
3379 			pr_crit("%s: Can't create sock SLAB cache!\n",
3380 				prot->name);
3381 			goto out;
3382 		}
3383 
3384 		if (req_prot_init(prot))
3385 			goto out_free_request_sock_slab;
3386 
3387 		if (prot->twsk_prot != NULL) {
3388 			prot->twsk_prot->twsk_slab_name = kasprintf(GFP_KERNEL, "tw_sock_%s", prot->name);
3389 
3390 			if (prot->twsk_prot->twsk_slab_name == NULL)
3391 				goto out_free_request_sock_slab;
3392 
3393 			prot->twsk_prot->twsk_slab =
3394 				kmem_cache_create(prot->twsk_prot->twsk_slab_name,
3395 						  prot->twsk_prot->twsk_obj_size,
3396 						  0,
3397 						  SLAB_ACCOUNT |
3398 						  prot->slab_flags,
3399 						  NULL);
3400 			if (prot->twsk_prot->twsk_slab == NULL)
3401 				goto out_free_timewait_sock_slab_name;
3402 		}
3403 	}
3404 
3405 	mutex_lock(&proto_list_mutex);
3406 	ret = assign_proto_idx(prot);
3407 	if (ret) {
3408 		mutex_unlock(&proto_list_mutex);
3409 		goto out_free_timewait_sock_slab_name;
3410 	}
3411 	list_add(&prot->node, &proto_list);
3412 	mutex_unlock(&proto_list_mutex);
3413 	return ret;
3414 
3415 out_free_timewait_sock_slab_name:
3416 	if (alloc_slab && prot->twsk_prot)
3417 		kfree(prot->twsk_prot->twsk_slab_name);
3418 out_free_request_sock_slab:
3419 	if (alloc_slab) {
3420 		req_prot_cleanup(prot->rsk_prot);
3421 
3422 		kmem_cache_destroy(prot->slab);
3423 		prot->slab = NULL;
3424 	}
3425 out:
3426 	return ret;
3427 }
3428 EXPORT_SYMBOL(proto_register);
3429 
3430 void proto_unregister(struct proto *prot)
3431 {
3432 	mutex_lock(&proto_list_mutex);
3433 	release_proto_idx(prot);
3434 	list_del(&prot->node);
3435 	mutex_unlock(&proto_list_mutex);
3436 
3437 	kmem_cache_destroy(prot->slab);
3438 	prot->slab = NULL;
3439 
3440 	req_prot_cleanup(prot->rsk_prot);
3441 
3442 	if (prot->twsk_prot != NULL && prot->twsk_prot->twsk_slab != NULL) {
3443 		kmem_cache_destroy(prot->twsk_prot->twsk_slab);
3444 		kfree(prot->twsk_prot->twsk_slab_name);
3445 		prot->twsk_prot->twsk_slab = NULL;
3446 	}
3447 }
3448 EXPORT_SYMBOL(proto_unregister);
3449 
3450 int sock_load_diag_module(int family, int protocol)
3451 {
3452 	if (!protocol) {
3453 		if (!sock_is_registered(family))
3454 			return -ENOENT;
3455 
3456 		return request_module("net-pf-%d-proto-%d-type-%d", PF_NETLINK,
3457 				      NETLINK_SOCK_DIAG, family);
3458 	}
3459 
3460 #ifdef CONFIG_INET
3461 	if (family == AF_INET &&
3462 	    protocol != IPPROTO_RAW &&
3463 	    !rcu_access_pointer(inet_protos[protocol]))
3464 		return -ENOENT;
3465 #endif
3466 
3467 	return request_module("net-pf-%d-proto-%d-type-%d-%d", PF_NETLINK,
3468 			      NETLINK_SOCK_DIAG, family, protocol);
3469 }
3470 EXPORT_SYMBOL(sock_load_diag_module);
3471 
3472 #ifdef CONFIG_PROC_FS
3473 static void *proto_seq_start(struct seq_file *seq, loff_t *pos)
3474 	__acquires(proto_list_mutex)
3475 {
3476 	mutex_lock(&proto_list_mutex);
3477 	return seq_list_start_head(&proto_list, *pos);
3478 }
3479 
3480 static void *proto_seq_next(struct seq_file *seq, void *v, loff_t *pos)
3481 {
3482 	return seq_list_next(v, &proto_list, pos);
3483 }
3484 
3485 static void proto_seq_stop(struct seq_file *seq, void *v)
3486 	__releases(proto_list_mutex)
3487 {
3488 	mutex_unlock(&proto_list_mutex);
3489 }
3490 
3491 static char proto_method_implemented(const void *method)
3492 {
3493 	return method == NULL ? 'n' : 'y';
3494 }
3495 static long sock_prot_memory_allocated(struct proto *proto)
3496 {
3497 	return proto->memory_allocated != NULL ? proto_memory_allocated(proto) : -1L;
3498 }
3499 
3500 static const char *sock_prot_memory_pressure(struct proto *proto)
3501 {
3502 	return proto->memory_pressure != NULL ?
3503 	proto_memory_pressure(proto) ? "yes" : "no" : "NI";
3504 }
3505 
3506 static void proto_seq_printf(struct seq_file *seq, struct proto *proto)
3507 {
3508 
3509 	seq_printf(seq, "%-9s %4u %6d  %6ld   %-3s %6u   %-3s  %-10s "
3510 			"%2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c\n",
3511 		   proto->name,
3512 		   proto->obj_size,
3513 		   sock_prot_inuse_get(seq_file_net(seq), proto),
3514 		   sock_prot_memory_allocated(proto),
3515 		   sock_prot_memory_pressure(proto),
3516 		   proto->max_header,
3517 		   proto->slab == NULL ? "no" : "yes",
3518 		   module_name(proto->owner),
3519 		   proto_method_implemented(proto->close),
3520 		   proto_method_implemented(proto->connect),
3521 		   proto_method_implemented(proto->disconnect),
3522 		   proto_method_implemented(proto->accept),
3523 		   proto_method_implemented(proto->ioctl),
3524 		   proto_method_implemented(proto->init),
3525 		   proto_method_implemented(proto->destroy),
3526 		   proto_method_implemented(proto->shutdown),
3527 		   proto_method_implemented(proto->setsockopt),
3528 		   proto_method_implemented(proto->getsockopt),
3529 		   proto_method_implemented(proto->sendmsg),
3530 		   proto_method_implemented(proto->recvmsg),
3531 		   proto_method_implemented(proto->sendpage),
3532 		   proto_method_implemented(proto->bind),
3533 		   proto_method_implemented(proto->backlog_rcv),
3534 		   proto_method_implemented(proto->hash),
3535 		   proto_method_implemented(proto->unhash),
3536 		   proto_method_implemented(proto->get_port),
3537 		   proto_method_implemented(proto->enter_memory_pressure));
3538 }
3539 
3540 static int proto_seq_show(struct seq_file *seq, void *v)
3541 {
3542 	if (v == &proto_list)
3543 		seq_printf(seq, "%-9s %-4s %-8s %-6s %-5s %-7s %-4s %-10s %s",
3544 			   "protocol",
3545 			   "size",
3546 			   "sockets",
3547 			   "memory",
3548 			   "press",
3549 			   "maxhdr",
3550 			   "slab",
3551 			   "module",
3552 			   "cl co di ac io in de sh ss gs se re sp bi br ha uh gp em\n");
3553 	else
3554 		proto_seq_printf(seq, list_entry(v, struct proto, node));
3555 	return 0;
3556 }
3557 
3558 static const struct seq_operations proto_seq_ops = {
3559 	.start  = proto_seq_start,
3560 	.next   = proto_seq_next,
3561 	.stop   = proto_seq_stop,
3562 	.show   = proto_seq_show,
3563 };
3564 
3565 static __net_init int proto_init_net(struct net *net)
3566 {
3567 	if (!proc_create_net("protocols", 0444, net->proc_net, &proto_seq_ops,
3568 			sizeof(struct seq_net_private)))
3569 		return -ENOMEM;
3570 
3571 	return 0;
3572 }
3573 
3574 static __net_exit void proto_exit_net(struct net *net)
3575 {
3576 	remove_proc_entry("protocols", net->proc_net);
3577 }
3578 
3579 
3580 static __net_initdata struct pernet_operations proto_net_ops = {
3581 	.init = proto_init_net,
3582 	.exit = proto_exit_net,
3583 };
3584 
3585 static int __init proto_init(void)
3586 {
3587 	return register_pernet_subsys(&proto_net_ops);
3588 }
3589 
3590 subsys_initcall(proto_init);
3591 
3592 #endif /* PROC_FS */
3593 
3594 #ifdef CONFIG_NET_RX_BUSY_POLL
3595 bool sk_busy_loop_end(void *p, unsigned long start_time)
3596 {
3597 	struct sock *sk = p;
3598 
3599 	return !skb_queue_empty(&sk->sk_receive_queue) ||
3600 	       sk_busy_loop_timeout(sk, start_time);
3601 }
3602 EXPORT_SYMBOL(sk_busy_loop_end);
3603 #endif /* CONFIG_NET_RX_BUSY_POLL */
3604