xref: /openbmc/linux/net/core/sock.c (revision 8622a0e5)
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 
337 	if (timeo == MAX_SCHEDULE_TIMEOUT) {
338 		tv.tv_sec = 0;
339 		tv.tv_usec = 0;
340 	} else {
341 		tv.tv_sec = timeo / HZ;
342 		tv.tv_usec = ((timeo % HZ) * USEC_PER_SEC) / HZ;
343 	}
344 
345 	if (old_timeval && in_compat_syscall() && !COMPAT_USE_64BIT_TIME) {
346 		struct old_timeval32 tv32 = { tv.tv_sec, tv.tv_usec };
347 		*(struct old_timeval32 *)optval = tv32;
348 		return sizeof(tv32);
349 	}
350 
351 	if (old_timeval) {
352 		struct __kernel_old_timeval old_tv;
353 		old_tv.tv_sec = tv.tv_sec;
354 		old_tv.tv_usec = tv.tv_usec;
355 		*(struct __kernel_old_timeval *)optval = old_tv;
356 		return sizeof(old_tv);
357 	}
358 
359 	*(struct __kernel_sock_timeval *)optval = tv;
360 	return sizeof(tv);
361 }
362 
363 static int sock_set_timeout(long *timeo_p, char __user *optval, int optlen, bool old_timeval)
364 {
365 	struct __kernel_sock_timeval tv;
366 
367 	if (old_timeval && in_compat_syscall() && !COMPAT_USE_64BIT_TIME) {
368 		struct old_timeval32 tv32;
369 
370 		if (optlen < sizeof(tv32))
371 			return -EINVAL;
372 
373 		if (copy_from_user(&tv32, optval, sizeof(tv32)))
374 			return -EFAULT;
375 		tv.tv_sec = tv32.tv_sec;
376 		tv.tv_usec = tv32.tv_usec;
377 	} else if (old_timeval) {
378 		struct __kernel_old_timeval old_tv;
379 
380 		if (optlen < sizeof(old_tv))
381 			return -EINVAL;
382 		if (copy_from_user(&old_tv, optval, sizeof(old_tv)))
383 			return -EFAULT;
384 		tv.tv_sec = old_tv.tv_sec;
385 		tv.tv_usec = old_tv.tv_usec;
386 	} else {
387 		if (optlen < sizeof(tv))
388 			return -EINVAL;
389 		if (copy_from_user(&tv, optval, sizeof(tv)))
390 			return -EFAULT;
391 	}
392 	if (tv.tv_usec < 0 || tv.tv_usec >= USEC_PER_SEC)
393 		return -EDOM;
394 
395 	if (tv.tv_sec < 0) {
396 		static int warned __read_mostly;
397 
398 		*timeo_p = 0;
399 		if (warned < 10 && net_ratelimit()) {
400 			warned++;
401 			pr_info("%s: `%s' (pid %d) tries to set negative timeout\n",
402 				__func__, current->comm, task_pid_nr(current));
403 		}
404 		return 0;
405 	}
406 	*timeo_p = MAX_SCHEDULE_TIMEOUT;
407 	if (tv.tv_sec == 0 && tv.tv_usec == 0)
408 		return 0;
409 	if (tv.tv_sec < (MAX_SCHEDULE_TIMEOUT / HZ - 1))
410 		*timeo_p = tv.tv_sec * HZ + DIV_ROUND_UP((unsigned long)tv.tv_usec, USEC_PER_SEC / HZ);
411 	return 0;
412 }
413 
414 static void sock_warn_obsolete_bsdism(const char *name)
415 {
416 	static int warned;
417 	static char warncomm[TASK_COMM_LEN];
418 	if (strcmp(warncomm, current->comm) && warned < 5) {
419 		strcpy(warncomm,  current->comm);
420 		pr_warn("process `%s' is using obsolete %s SO_BSDCOMPAT\n",
421 			warncomm, name);
422 		warned++;
423 	}
424 }
425 
426 static bool sock_needs_netstamp(const struct sock *sk)
427 {
428 	switch (sk->sk_family) {
429 	case AF_UNSPEC:
430 	case AF_UNIX:
431 		return false;
432 	default:
433 		return true;
434 	}
435 }
436 
437 static void sock_disable_timestamp(struct sock *sk, unsigned long flags)
438 {
439 	if (sk->sk_flags & flags) {
440 		sk->sk_flags &= ~flags;
441 		if (sock_needs_netstamp(sk) &&
442 		    !(sk->sk_flags & SK_FLAGS_TIMESTAMP))
443 			net_disable_timestamp();
444 	}
445 }
446 
447 
448 int __sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
449 {
450 	unsigned long flags;
451 	struct sk_buff_head *list = &sk->sk_receive_queue;
452 
453 	if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf) {
454 		atomic_inc(&sk->sk_drops);
455 		trace_sock_rcvqueue_full(sk, skb);
456 		return -ENOMEM;
457 	}
458 
459 	if (!sk_rmem_schedule(sk, skb, skb->truesize)) {
460 		atomic_inc(&sk->sk_drops);
461 		return -ENOBUFS;
462 	}
463 
464 	skb->dev = NULL;
465 	skb_set_owner_r(skb, sk);
466 
467 	/* we escape from rcu protected region, make sure we dont leak
468 	 * a norefcounted dst
469 	 */
470 	skb_dst_force(skb);
471 
472 	spin_lock_irqsave(&list->lock, flags);
473 	sock_skb_set_dropcount(sk, skb);
474 	__skb_queue_tail(list, skb);
475 	spin_unlock_irqrestore(&list->lock, flags);
476 
477 	if (!sock_flag(sk, SOCK_DEAD))
478 		sk->sk_data_ready(sk);
479 	return 0;
480 }
481 EXPORT_SYMBOL(__sock_queue_rcv_skb);
482 
483 int sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
484 {
485 	int err;
486 
487 	err = sk_filter(sk, skb);
488 	if (err)
489 		return err;
490 
491 	return __sock_queue_rcv_skb(sk, skb);
492 }
493 EXPORT_SYMBOL(sock_queue_rcv_skb);
494 
495 int __sk_receive_skb(struct sock *sk, struct sk_buff *skb,
496 		     const int nested, unsigned int trim_cap, bool refcounted)
497 {
498 	int rc = NET_RX_SUCCESS;
499 
500 	if (sk_filter_trim_cap(sk, skb, trim_cap))
501 		goto discard_and_relse;
502 
503 	skb->dev = NULL;
504 
505 	if (sk_rcvqueues_full(sk, sk->sk_rcvbuf)) {
506 		atomic_inc(&sk->sk_drops);
507 		goto discard_and_relse;
508 	}
509 	if (nested)
510 		bh_lock_sock_nested(sk);
511 	else
512 		bh_lock_sock(sk);
513 	if (!sock_owned_by_user(sk)) {
514 		/*
515 		 * trylock + unlock semantics:
516 		 */
517 		mutex_acquire(&sk->sk_lock.dep_map, 0, 1, _RET_IP_);
518 
519 		rc = sk_backlog_rcv(sk, skb);
520 
521 		mutex_release(&sk->sk_lock.dep_map, _RET_IP_);
522 	} else if (sk_add_backlog(sk, skb, READ_ONCE(sk->sk_rcvbuf))) {
523 		bh_unlock_sock(sk);
524 		atomic_inc(&sk->sk_drops);
525 		goto discard_and_relse;
526 	}
527 
528 	bh_unlock_sock(sk);
529 out:
530 	if (refcounted)
531 		sock_put(sk);
532 	return rc;
533 discard_and_relse:
534 	kfree_skb(skb);
535 	goto out;
536 }
537 EXPORT_SYMBOL(__sk_receive_skb);
538 
539 struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie)
540 {
541 	struct dst_entry *dst = __sk_dst_get(sk);
542 
543 	if (dst && dst->obsolete && dst->ops->check(dst, cookie) == NULL) {
544 		sk_tx_queue_clear(sk);
545 		sk->sk_dst_pending_confirm = 0;
546 		RCU_INIT_POINTER(sk->sk_dst_cache, NULL);
547 		dst_release(dst);
548 		return NULL;
549 	}
550 
551 	return dst;
552 }
553 EXPORT_SYMBOL(__sk_dst_check);
554 
555 struct dst_entry *sk_dst_check(struct sock *sk, u32 cookie)
556 {
557 	struct dst_entry *dst = sk_dst_get(sk);
558 
559 	if (dst && dst->obsolete && dst->ops->check(dst, cookie) == NULL) {
560 		sk_dst_reset(sk);
561 		dst_release(dst);
562 		return NULL;
563 	}
564 
565 	return dst;
566 }
567 EXPORT_SYMBOL(sk_dst_check);
568 
569 static int sock_setbindtodevice_locked(struct sock *sk, int ifindex)
570 {
571 	int ret = -ENOPROTOOPT;
572 #ifdef CONFIG_NETDEVICES
573 	struct net *net = sock_net(sk);
574 
575 	/* Sorry... */
576 	ret = -EPERM;
577 	if (!ns_capable(net->user_ns, CAP_NET_RAW))
578 		goto out;
579 
580 	ret = -EINVAL;
581 	if (ifindex < 0)
582 		goto out;
583 
584 	sk->sk_bound_dev_if = ifindex;
585 	if (sk->sk_prot->rehash)
586 		sk->sk_prot->rehash(sk);
587 	sk_dst_reset(sk);
588 
589 	ret = 0;
590 
591 out:
592 #endif
593 
594 	return ret;
595 }
596 
597 static int sock_setbindtodevice(struct sock *sk, char __user *optval,
598 				int optlen)
599 {
600 	int ret = -ENOPROTOOPT;
601 #ifdef CONFIG_NETDEVICES
602 	struct net *net = sock_net(sk);
603 	char devname[IFNAMSIZ];
604 	int index;
605 
606 	ret = -EINVAL;
607 	if (optlen < 0)
608 		goto out;
609 
610 	/* Bind this socket to a particular device like "eth0",
611 	 * as specified in the passed interface name. If the
612 	 * name is "" or the option length is zero the socket
613 	 * is not bound.
614 	 */
615 	if (optlen > IFNAMSIZ - 1)
616 		optlen = IFNAMSIZ - 1;
617 	memset(devname, 0, sizeof(devname));
618 
619 	ret = -EFAULT;
620 	if (copy_from_user(devname, optval, optlen))
621 		goto out;
622 
623 	index = 0;
624 	if (devname[0] != '\0') {
625 		struct net_device *dev;
626 
627 		rcu_read_lock();
628 		dev = dev_get_by_name_rcu(net, devname);
629 		if (dev)
630 			index = dev->ifindex;
631 		rcu_read_unlock();
632 		ret = -ENODEV;
633 		if (!dev)
634 			goto out;
635 	}
636 
637 	lock_sock(sk);
638 	ret = sock_setbindtodevice_locked(sk, index);
639 	release_sock(sk);
640 
641 out:
642 #endif
643 
644 	return ret;
645 }
646 
647 static int sock_getbindtodevice(struct sock *sk, char __user *optval,
648 				int __user *optlen, int len)
649 {
650 	int ret = -ENOPROTOOPT;
651 #ifdef CONFIG_NETDEVICES
652 	struct net *net = sock_net(sk);
653 	char devname[IFNAMSIZ];
654 
655 	if (sk->sk_bound_dev_if == 0) {
656 		len = 0;
657 		goto zero;
658 	}
659 
660 	ret = -EINVAL;
661 	if (len < IFNAMSIZ)
662 		goto out;
663 
664 	ret = netdev_get_name(net, devname, sk->sk_bound_dev_if);
665 	if (ret)
666 		goto out;
667 
668 	len = strlen(devname) + 1;
669 
670 	ret = -EFAULT;
671 	if (copy_to_user(optval, devname, len))
672 		goto out;
673 
674 zero:
675 	ret = -EFAULT;
676 	if (put_user(len, optlen))
677 		goto out;
678 
679 	ret = 0;
680 
681 out:
682 #endif
683 
684 	return ret;
685 }
686 
687 static inline void sock_valbool_flag(struct sock *sk, enum sock_flags bit,
688 				     int valbool)
689 {
690 	if (valbool)
691 		sock_set_flag(sk, bit);
692 	else
693 		sock_reset_flag(sk, bit);
694 }
695 
696 bool sk_mc_loop(struct sock *sk)
697 {
698 	if (dev_recursion_level())
699 		return false;
700 	if (!sk)
701 		return true;
702 	switch (sk->sk_family) {
703 	case AF_INET:
704 		return inet_sk(sk)->mc_loop;
705 #if IS_ENABLED(CONFIG_IPV6)
706 	case AF_INET6:
707 		return inet6_sk(sk)->mc_loop;
708 #endif
709 	}
710 	WARN_ON(1);
711 	return true;
712 }
713 EXPORT_SYMBOL(sk_mc_loop);
714 
715 /*
716  *	This is meant for all protocols to use and covers goings on
717  *	at the socket level. Everything here is generic.
718  */
719 
720 int sock_setsockopt(struct socket *sock, int level, int optname,
721 		    char __user *optval, unsigned int optlen)
722 {
723 	struct sock_txtime sk_txtime;
724 	struct sock *sk = sock->sk;
725 	int val;
726 	int valbool;
727 	struct linger ling;
728 	int ret = 0;
729 
730 	/*
731 	 *	Options without arguments
732 	 */
733 
734 	if (optname == SO_BINDTODEVICE)
735 		return sock_setbindtodevice(sk, optval, optlen);
736 
737 	if (optlen < sizeof(int))
738 		return -EINVAL;
739 
740 	if (get_user(val, (int __user *)optval))
741 		return -EFAULT;
742 
743 	valbool = val ? 1 : 0;
744 
745 	lock_sock(sk);
746 
747 	switch (optname) {
748 	case SO_DEBUG:
749 		if (val && !capable(CAP_NET_ADMIN))
750 			ret = -EACCES;
751 		else
752 			sock_valbool_flag(sk, SOCK_DBG, valbool);
753 		break;
754 	case SO_REUSEADDR:
755 		sk->sk_reuse = (valbool ? SK_CAN_REUSE : SK_NO_REUSE);
756 		break;
757 	case SO_REUSEPORT:
758 		sk->sk_reuseport = valbool;
759 		break;
760 	case SO_TYPE:
761 	case SO_PROTOCOL:
762 	case SO_DOMAIN:
763 	case SO_ERROR:
764 		ret = -ENOPROTOOPT;
765 		break;
766 	case SO_DONTROUTE:
767 		sock_valbool_flag(sk, SOCK_LOCALROUTE, valbool);
768 		sk_dst_reset(sk);
769 		break;
770 	case SO_BROADCAST:
771 		sock_valbool_flag(sk, SOCK_BROADCAST, valbool);
772 		break;
773 	case SO_SNDBUF:
774 		/* Don't error on this BSD doesn't and if you think
775 		 * about it this is right. Otherwise apps have to
776 		 * play 'guess the biggest size' games. RCVBUF/SNDBUF
777 		 * are treated in BSD as hints
778 		 */
779 		val = min_t(u32, val, sysctl_wmem_max);
780 set_sndbuf:
781 		/* Ensure val * 2 fits into an int, to prevent max_t()
782 		 * from treating it as a negative value.
783 		 */
784 		val = min_t(int, val, INT_MAX / 2);
785 		sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
786 		WRITE_ONCE(sk->sk_sndbuf,
787 			   max_t(int, val * 2, SOCK_MIN_SNDBUF));
788 		/* Wake up sending tasks if we upped the value. */
789 		sk->sk_write_space(sk);
790 		break;
791 
792 	case SO_SNDBUFFORCE:
793 		if (!capable(CAP_NET_ADMIN)) {
794 			ret = -EPERM;
795 			break;
796 		}
797 
798 		/* No negative values (to prevent underflow, as val will be
799 		 * multiplied by 2).
800 		 */
801 		if (val < 0)
802 			val = 0;
803 		goto set_sndbuf;
804 
805 	case SO_RCVBUF:
806 		/* Don't error on this BSD doesn't and if you think
807 		 * about it this is right. Otherwise apps have to
808 		 * play 'guess the biggest size' games. RCVBUF/SNDBUF
809 		 * are treated in BSD as hints
810 		 */
811 		val = min_t(u32, val, sysctl_rmem_max);
812 set_rcvbuf:
813 		/* Ensure val * 2 fits into an int, to prevent max_t()
814 		 * from treating it as a negative value.
815 		 */
816 		val = min_t(int, val, INT_MAX / 2);
817 		sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
818 		/*
819 		 * We double it on the way in to account for
820 		 * "struct sk_buff" etc. overhead.   Applications
821 		 * assume that the SO_RCVBUF setting they make will
822 		 * allow that much actual data to be received on that
823 		 * socket.
824 		 *
825 		 * Applications are unaware that "struct sk_buff" and
826 		 * other overheads allocate from the receive buffer
827 		 * during socket buffer allocation.
828 		 *
829 		 * And after considering the possible alternatives,
830 		 * returning the value we actually used in getsockopt
831 		 * is the most desirable behavior.
832 		 */
833 		WRITE_ONCE(sk->sk_rcvbuf,
834 			   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 			WRITE_ONCE(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 		WRITE_ONCE(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 = READ_ONCE(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 	const struct proto *prot = READ_ONCE(osk->sk_prot);
1576 #ifdef CONFIG_SECURITY_NETWORK
1577 	void *sptr = nsk->sk_security;
1578 #endif
1579 	memcpy(nsk, osk, offsetof(struct sock, sk_dontcopy_begin));
1580 
1581 	memcpy(&nsk->sk_dontcopy_end, &osk->sk_dontcopy_end,
1582 	       prot->obj_size - offsetof(struct sock, sk_dontcopy_end));
1583 
1584 #ifdef CONFIG_SECURITY_NETWORK
1585 	nsk->sk_security = sptr;
1586 	security_sk_clone(osk, nsk);
1587 #endif
1588 }
1589 
1590 static struct sock *sk_prot_alloc(struct proto *prot, gfp_t priority,
1591 		int family)
1592 {
1593 	struct sock *sk;
1594 	struct kmem_cache *slab;
1595 
1596 	slab = prot->slab;
1597 	if (slab != NULL) {
1598 		sk = kmem_cache_alloc(slab, priority & ~__GFP_ZERO);
1599 		if (!sk)
1600 			return sk;
1601 		if (want_init_on_alloc(priority))
1602 			sk_prot_clear_nulls(sk, prot->obj_size);
1603 	} else
1604 		sk = kmalloc(prot->obj_size, priority);
1605 
1606 	if (sk != NULL) {
1607 		if (security_sk_alloc(sk, family, priority))
1608 			goto out_free;
1609 
1610 		if (!try_module_get(prot->owner))
1611 			goto out_free_sec;
1612 		sk_tx_queue_clear(sk);
1613 	}
1614 
1615 	return sk;
1616 
1617 out_free_sec:
1618 	security_sk_free(sk);
1619 out_free:
1620 	if (slab != NULL)
1621 		kmem_cache_free(slab, sk);
1622 	else
1623 		kfree(sk);
1624 	return NULL;
1625 }
1626 
1627 static void sk_prot_free(struct proto *prot, struct sock *sk)
1628 {
1629 	struct kmem_cache *slab;
1630 	struct module *owner;
1631 
1632 	owner = prot->owner;
1633 	slab = prot->slab;
1634 
1635 	cgroup_sk_free(&sk->sk_cgrp_data);
1636 	mem_cgroup_sk_free(sk);
1637 	security_sk_free(sk);
1638 	if (slab != NULL)
1639 		kmem_cache_free(slab, sk);
1640 	else
1641 		kfree(sk);
1642 	module_put(owner);
1643 }
1644 
1645 /**
1646  *	sk_alloc - All socket objects are allocated here
1647  *	@net: the applicable net namespace
1648  *	@family: protocol family
1649  *	@priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
1650  *	@prot: struct proto associated with this new sock instance
1651  *	@kern: is this to be a kernel socket?
1652  */
1653 struct sock *sk_alloc(struct net *net, int family, gfp_t priority,
1654 		      struct proto *prot, int kern)
1655 {
1656 	struct sock *sk;
1657 
1658 	sk = sk_prot_alloc(prot, priority | __GFP_ZERO, family);
1659 	if (sk) {
1660 		sk->sk_family = family;
1661 		/*
1662 		 * See comment in struct sock definition to understand
1663 		 * why we need sk_prot_creator -acme
1664 		 */
1665 		sk->sk_prot = sk->sk_prot_creator = prot;
1666 		sk->sk_kern_sock = kern;
1667 		sock_lock_init(sk);
1668 		sk->sk_net_refcnt = kern ? 0 : 1;
1669 		if (likely(sk->sk_net_refcnt)) {
1670 			get_net(net);
1671 			sock_inuse_add(net, 1);
1672 		}
1673 
1674 		sock_net_set(sk, net);
1675 		refcount_set(&sk->sk_wmem_alloc, 1);
1676 
1677 		mem_cgroup_sk_alloc(sk);
1678 		cgroup_sk_alloc(&sk->sk_cgrp_data);
1679 		sock_update_classid(&sk->sk_cgrp_data);
1680 		sock_update_netprioidx(&sk->sk_cgrp_data);
1681 	}
1682 
1683 	return sk;
1684 }
1685 EXPORT_SYMBOL(sk_alloc);
1686 
1687 /* Sockets having SOCK_RCU_FREE will call this function after one RCU
1688  * grace period. This is the case for UDP sockets and TCP listeners.
1689  */
1690 static void __sk_destruct(struct rcu_head *head)
1691 {
1692 	struct sock *sk = container_of(head, struct sock, sk_rcu);
1693 	struct sk_filter *filter;
1694 
1695 	if (sk->sk_destruct)
1696 		sk->sk_destruct(sk);
1697 
1698 	filter = rcu_dereference_check(sk->sk_filter,
1699 				       refcount_read(&sk->sk_wmem_alloc) == 0);
1700 	if (filter) {
1701 		sk_filter_uncharge(sk, filter);
1702 		RCU_INIT_POINTER(sk->sk_filter, NULL);
1703 	}
1704 
1705 	sock_disable_timestamp(sk, SK_FLAGS_TIMESTAMP);
1706 
1707 #ifdef CONFIG_BPF_SYSCALL
1708 	bpf_sk_storage_free(sk);
1709 #endif
1710 
1711 	if (atomic_read(&sk->sk_omem_alloc))
1712 		pr_debug("%s: optmem leakage (%d bytes) detected\n",
1713 			 __func__, atomic_read(&sk->sk_omem_alloc));
1714 
1715 	if (sk->sk_frag.page) {
1716 		put_page(sk->sk_frag.page);
1717 		sk->sk_frag.page = NULL;
1718 	}
1719 
1720 	if (sk->sk_peer_cred)
1721 		put_cred(sk->sk_peer_cred);
1722 	put_pid(sk->sk_peer_pid);
1723 	if (likely(sk->sk_net_refcnt))
1724 		put_net(sock_net(sk));
1725 	sk_prot_free(sk->sk_prot_creator, sk);
1726 }
1727 
1728 void sk_destruct(struct sock *sk)
1729 {
1730 	bool use_call_rcu = sock_flag(sk, SOCK_RCU_FREE);
1731 
1732 	if (rcu_access_pointer(sk->sk_reuseport_cb)) {
1733 		reuseport_detach_sock(sk);
1734 		use_call_rcu = true;
1735 	}
1736 
1737 	if (use_call_rcu)
1738 		call_rcu(&sk->sk_rcu, __sk_destruct);
1739 	else
1740 		__sk_destruct(&sk->sk_rcu);
1741 }
1742 
1743 static void __sk_free(struct sock *sk)
1744 {
1745 	if (likely(sk->sk_net_refcnt))
1746 		sock_inuse_add(sock_net(sk), -1);
1747 
1748 	if (unlikely(sk->sk_net_refcnt && sock_diag_has_destroy_listeners(sk)))
1749 		sock_diag_broadcast_destroy(sk);
1750 	else
1751 		sk_destruct(sk);
1752 }
1753 
1754 void sk_free(struct sock *sk)
1755 {
1756 	/*
1757 	 * We subtract one from sk_wmem_alloc and can know if
1758 	 * some packets are still in some tx queue.
1759 	 * If not null, sock_wfree() will call __sk_free(sk) later
1760 	 */
1761 	if (refcount_dec_and_test(&sk->sk_wmem_alloc))
1762 		__sk_free(sk);
1763 }
1764 EXPORT_SYMBOL(sk_free);
1765 
1766 static void sk_init_common(struct sock *sk)
1767 {
1768 	skb_queue_head_init(&sk->sk_receive_queue);
1769 	skb_queue_head_init(&sk->sk_write_queue);
1770 	skb_queue_head_init(&sk->sk_error_queue);
1771 
1772 	rwlock_init(&sk->sk_callback_lock);
1773 	lockdep_set_class_and_name(&sk->sk_receive_queue.lock,
1774 			af_rlock_keys + sk->sk_family,
1775 			af_family_rlock_key_strings[sk->sk_family]);
1776 	lockdep_set_class_and_name(&sk->sk_write_queue.lock,
1777 			af_wlock_keys + sk->sk_family,
1778 			af_family_wlock_key_strings[sk->sk_family]);
1779 	lockdep_set_class_and_name(&sk->sk_error_queue.lock,
1780 			af_elock_keys + sk->sk_family,
1781 			af_family_elock_key_strings[sk->sk_family]);
1782 	lockdep_set_class_and_name(&sk->sk_callback_lock,
1783 			af_callback_keys + sk->sk_family,
1784 			af_family_clock_key_strings[sk->sk_family]);
1785 }
1786 
1787 /**
1788  *	sk_clone_lock - clone a socket, and lock its clone
1789  *	@sk: the socket to clone
1790  *	@priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
1791  *
1792  *	Caller must unlock socket even in error path (bh_unlock_sock(newsk))
1793  */
1794 struct sock *sk_clone_lock(const struct sock *sk, const gfp_t priority)
1795 {
1796 	struct proto *prot = READ_ONCE(sk->sk_prot);
1797 	struct sock *newsk;
1798 	bool is_charged = true;
1799 
1800 	newsk = sk_prot_alloc(prot, priority, sk->sk_family);
1801 	if (newsk != NULL) {
1802 		struct sk_filter *filter;
1803 
1804 		sock_copy(newsk, sk);
1805 
1806 		newsk->sk_prot_creator = prot;
1807 
1808 		/* SANITY */
1809 		if (likely(newsk->sk_net_refcnt))
1810 			get_net(sock_net(newsk));
1811 		sk_node_init(&newsk->sk_node);
1812 		sock_lock_init(newsk);
1813 		bh_lock_sock(newsk);
1814 		newsk->sk_backlog.head	= newsk->sk_backlog.tail = NULL;
1815 		newsk->sk_backlog.len = 0;
1816 
1817 		atomic_set(&newsk->sk_rmem_alloc, 0);
1818 		/*
1819 		 * sk_wmem_alloc set to one (see sk_free() and sock_wfree())
1820 		 */
1821 		refcount_set(&newsk->sk_wmem_alloc, 1);
1822 		atomic_set(&newsk->sk_omem_alloc, 0);
1823 		sk_init_common(newsk);
1824 
1825 		newsk->sk_dst_cache	= NULL;
1826 		newsk->sk_dst_pending_confirm = 0;
1827 		newsk->sk_wmem_queued	= 0;
1828 		newsk->sk_forward_alloc = 0;
1829 		atomic_set(&newsk->sk_drops, 0);
1830 		newsk->sk_send_head	= NULL;
1831 		newsk->sk_userlocks	= sk->sk_userlocks & ~SOCK_BINDPORT_LOCK;
1832 		atomic_set(&newsk->sk_zckey, 0);
1833 
1834 		sock_reset_flag(newsk, SOCK_DONE);
1835 		mem_cgroup_sk_alloc(newsk);
1836 		cgroup_sk_alloc(&newsk->sk_cgrp_data);
1837 
1838 		rcu_read_lock();
1839 		filter = rcu_dereference(sk->sk_filter);
1840 		if (filter != NULL)
1841 			/* though it's an empty new sock, the charging may fail
1842 			 * if sysctl_optmem_max was changed between creation of
1843 			 * original socket and cloning
1844 			 */
1845 			is_charged = sk_filter_charge(newsk, filter);
1846 		RCU_INIT_POINTER(newsk->sk_filter, filter);
1847 		rcu_read_unlock();
1848 
1849 		if (unlikely(!is_charged || xfrm_sk_clone_policy(newsk, sk))) {
1850 			/* We need to make sure that we don't uncharge the new
1851 			 * socket if we couldn't charge it in the first place
1852 			 * as otherwise we uncharge the parent's filter.
1853 			 */
1854 			if (!is_charged)
1855 				RCU_INIT_POINTER(newsk->sk_filter, NULL);
1856 			sk_free_unlock_clone(newsk);
1857 			newsk = NULL;
1858 			goto out;
1859 		}
1860 		RCU_INIT_POINTER(newsk->sk_reuseport_cb, NULL);
1861 
1862 		if (bpf_sk_storage_clone(sk, newsk)) {
1863 			sk_free_unlock_clone(newsk);
1864 			newsk = NULL;
1865 			goto out;
1866 		}
1867 
1868 		/* Clear sk_user_data if parent had the pointer tagged
1869 		 * as not suitable for copying when cloning.
1870 		 */
1871 		if (sk_user_data_is_nocopy(newsk))
1872 			RCU_INIT_POINTER(newsk->sk_user_data, NULL);
1873 
1874 		newsk->sk_err	   = 0;
1875 		newsk->sk_err_soft = 0;
1876 		newsk->sk_priority = 0;
1877 		newsk->sk_incoming_cpu = raw_smp_processor_id();
1878 		if (likely(newsk->sk_net_refcnt))
1879 			sock_inuse_add(sock_net(newsk), 1);
1880 
1881 		/*
1882 		 * Before updating sk_refcnt, we must commit prior changes to memory
1883 		 * (Documentation/RCU/rculist_nulls.txt for details)
1884 		 */
1885 		smp_wmb();
1886 		refcount_set(&newsk->sk_refcnt, 2);
1887 
1888 		/*
1889 		 * Increment the counter in the same struct proto as the master
1890 		 * sock (sk_refcnt_debug_inc uses newsk->sk_prot->socks, that
1891 		 * is the same as sk->sk_prot->socks, as this field was copied
1892 		 * with memcpy).
1893 		 *
1894 		 * This _changes_ the previous behaviour, where
1895 		 * tcp_create_openreq_child always was incrementing the
1896 		 * equivalent to tcp_prot->socks (inet_sock_nr), so this have
1897 		 * to be taken into account in all callers. -acme
1898 		 */
1899 		sk_refcnt_debug_inc(newsk);
1900 		sk_set_socket(newsk, NULL);
1901 		RCU_INIT_POINTER(newsk->sk_wq, NULL);
1902 
1903 		if (newsk->sk_prot->sockets_allocated)
1904 			sk_sockets_allocated_inc(newsk);
1905 
1906 		if (sock_needs_netstamp(sk) &&
1907 		    newsk->sk_flags & SK_FLAGS_TIMESTAMP)
1908 			net_enable_timestamp();
1909 	}
1910 out:
1911 	return newsk;
1912 }
1913 EXPORT_SYMBOL_GPL(sk_clone_lock);
1914 
1915 void sk_free_unlock_clone(struct sock *sk)
1916 {
1917 	/* It is still raw copy of parent, so invalidate
1918 	 * destructor and make plain sk_free() */
1919 	sk->sk_destruct = NULL;
1920 	bh_unlock_sock(sk);
1921 	sk_free(sk);
1922 }
1923 EXPORT_SYMBOL_GPL(sk_free_unlock_clone);
1924 
1925 void sk_setup_caps(struct sock *sk, struct dst_entry *dst)
1926 {
1927 	u32 max_segs = 1;
1928 
1929 	sk_dst_set(sk, dst);
1930 	sk->sk_route_caps = dst->dev->features | sk->sk_route_forced_caps;
1931 	if (sk->sk_route_caps & NETIF_F_GSO)
1932 		sk->sk_route_caps |= NETIF_F_GSO_SOFTWARE;
1933 	sk->sk_route_caps &= ~sk->sk_route_nocaps;
1934 	if (sk_can_gso(sk)) {
1935 		if (dst->header_len && !xfrm_dst_offload_ok(dst)) {
1936 			sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
1937 		} else {
1938 			sk->sk_route_caps |= NETIF_F_SG | NETIF_F_HW_CSUM;
1939 			sk->sk_gso_max_size = dst->dev->gso_max_size;
1940 			max_segs = max_t(u32, dst->dev->gso_max_segs, 1);
1941 		}
1942 	}
1943 	sk->sk_gso_max_segs = max_segs;
1944 }
1945 EXPORT_SYMBOL_GPL(sk_setup_caps);
1946 
1947 /*
1948  *	Simple resource managers for sockets.
1949  */
1950 
1951 
1952 /*
1953  * Write buffer destructor automatically called from kfree_skb.
1954  */
1955 void sock_wfree(struct sk_buff *skb)
1956 {
1957 	struct sock *sk = skb->sk;
1958 	unsigned int len = skb->truesize;
1959 
1960 	if (!sock_flag(sk, SOCK_USE_WRITE_QUEUE)) {
1961 		/*
1962 		 * Keep a reference on sk_wmem_alloc, this will be released
1963 		 * after sk_write_space() call
1964 		 */
1965 		WARN_ON(refcount_sub_and_test(len - 1, &sk->sk_wmem_alloc));
1966 		sk->sk_write_space(sk);
1967 		len = 1;
1968 	}
1969 	/*
1970 	 * if sk_wmem_alloc reaches 0, we must finish what sk_free()
1971 	 * could not do because of in-flight packets
1972 	 */
1973 	if (refcount_sub_and_test(len, &sk->sk_wmem_alloc))
1974 		__sk_free(sk);
1975 }
1976 EXPORT_SYMBOL(sock_wfree);
1977 
1978 /* This variant of sock_wfree() is used by TCP,
1979  * since it sets SOCK_USE_WRITE_QUEUE.
1980  */
1981 void __sock_wfree(struct sk_buff *skb)
1982 {
1983 	struct sock *sk = skb->sk;
1984 
1985 	if (refcount_sub_and_test(skb->truesize, &sk->sk_wmem_alloc))
1986 		__sk_free(sk);
1987 }
1988 
1989 void skb_set_owner_w(struct sk_buff *skb, struct sock *sk)
1990 {
1991 	skb_orphan(skb);
1992 	skb->sk = sk;
1993 #ifdef CONFIG_INET
1994 	if (unlikely(!sk_fullsock(sk))) {
1995 		skb->destructor = sock_edemux;
1996 		sock_hold(sk);
1997 		return;
1998 	}
1999 #endif
2000 	skb->destructor = sock_wfree;
2001 	skb_set_hash_from_sk(skb, sk);
2002 	/*
2003 	 * We used to take a refcount on sk, but following operation
2004 	 * is enough to guarantee sk_free() wont free this sock until
2005 	 * all in-flight packets are completed
2006 	 */
2007 	refcount_add(skb->truesize, &sk->sk_wmem_alloc);
2008 }
2009 EXPORT_SYMBOL(skb_set_owner_w);
2010 
2011 static bool can_skb_orphan_partial(const struct sk_buff *skb)
2012 {
2013 #ifdef CONFIG_TLS_DEVICE
2014 	/* Drivers depend on in-order delivery for crypto offload,
2015 	 * partial orphan breaks out-of-order-OK logic.
2016 	 */
2017 	if (skb->decrypted)
2018 		return false;
2019 #endif
2020 	return (skb->destructor == sock_wfree ||
2021 		(IS_ENABLED(CONFIG_INET) && skb->destructor == tcp_wfree));
2022 }
2023 
2024 /* This helper is used by netem, as it can hold packets in its
2025  * delay queue. We want to allow the owner socket to send more
2026  * packets, as if they were already TX completed by a typical driver.
2027  * But we also want to keep skb->sk set because some packet schedulers
2028  * rely on it (sch_fq for example).
2029  */
2030 void skb_orphan_partial(struct sk_buff *skb)
2031 {
2032 	if (skb_is_tcp_pure_ack(skb))
2033 		return;
2034 
2035 	if (can_skb_orphan_partial(skb)) {
2036 		struct sock *sk = skb->sk;
2037 
2038 		if (refcount_inc_not_zero(&sk->sk_refcnt)) {
2039 			WARN_ON(refcount_sub_and_test(skb->truesize, &sk->sk_wmem_alloc));
2040 			skb->destructor = sock_efree;
2041 		}
2042 	} else {
2043 		skb_orphan(skb);
2044 	}
2045 }
2046 EXPORT_SYMBOL(skb_orphan_partial);
2047 
2048 /*
2049  * Read buffer destructor automatically called from kfree_skb.
2050  */
2051 void sock_rfree(struct sk_buff *skb)
2052 {
2053 	struct sock *sk = skb->sk;
2054 	unsigned int len = skb->truesize;
2055 
2056 	atomic_sub(len, &sk->sk_rmem_alloc);
2057 	sk_mem_uncharge(sk, len);
2058 }
2059 EXPORT_SYMBOL(sock_rfree);
2060 
2061 /*
2062  * Buffer destructor for skbs that are not used directly in read or write
2063  * path, e.g. for error handler skbs. Automatically called from kfree_skb.
2064  */
2065 void sock_efree(struct sk_buff *skb)
2066 {
2067 	sock_put(skb->sk);
2068 }
2069 EXPORT_SYMBOL(sock_efree);
2070 
2071 kuid_t sock_i_uid(struct sock *sk)
2072 {
2073 	kuid_t uid;
2074 
2075 	read_lock_bh(&sk->sk_callback_lock);
2076 	uid = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_uid : GLOBAL_ROOT_UID;
2077 	read_unlock_bh(&sk->sk_callback_lock);
2078 	return uid;
2079 }
2080 EXPORT_SYMBOL(sock_i_uid);
2081 
2082 unsigned long sock_i_ino(struct sock *sk)
2083 {
2084 	unsigned long ino;
2085 
2086 	read_lock_bh(&sk->sk_callback_lock);
2087 	ino = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_ino : 0;
2088 	read_unlock_bh(&sk->sk_callback_lock);
2089 	return ino;
2090 }
2091 EXPORT_SYMBOL(sock_i_ino);
2092 
2093 /*
2094  * Allocate a skb from the socket's send buffer.
2095  */
2096 struct sk_buff *sock_wmalloc(struct sock *sk, unsigned long size, int force,
2097 			     gfp_t priority)
2098 {
2099 	if (force ||
2100 	    refcount_read(&sk->sk_wmem_alloc) < READ_ONCE(sk->sk_sndbuf)) {
2101 		struct sk_buff *skb = alloc_skb(size, priority);
2102 
2103 		if (skb) {
2104 			skb_set_owner_w(skb, sk);
2105 			return skb;
2106 		}
2107 	}
2108 	return NULL;
2109 }
2110 EXPORT_SYMBOL(sock_wmalloc);
2111 
2112 static void sock_ofree(struct sk_buff *skb)
2113 {
2114 	struct sock *sk = skb->sk;
2115 
2116 	atomic_sub(skb->truesize, &sk->sk_omem_alloc);
2117 }
2118 
2119 struct sk_buff *sock_omalloc(struct sock *sk, unsigned long size,
2120 			     gfp_t priority)
2121 {
2122 	struct sk_buff *skb;
2123 
2124 	/* small safe race: SKB_TRUESIZE may differ from final skb->truesize */
2125 	if (atomic_read(&sk->sk_omem_alloc) + SKB_TRUESIZE(size) >
2126 	    sysctl_optmem_max)
2127 		return NULL;
2128 
2129 	skb = alloc_skb(size, priority);
2130 	if (!skb)
2131 		return NULL;
2132 
2133 	atomic_add(skb->truesize, &sk->sk_omem_alloc);
2134 	skb->sk = sk;
2135 	skb->destructor = sock_ofree;
2136 	return skb;
2137 }
2138 
2139 /*
2140  * Allocate a memory block from the socket's option memory buffer.
2141  */
2142 void *sock_kmalloc(struct sock *sk, int size, gfp_t priority)
2143 {
2144 	if ((unsigned int)size <= sysctl_optmem_max &&
2145 	    atomic_read(&sk->sk_omem_alloc) + size < sysctl_optmem_max) {
2146 		void *mem;
2147 		/* First do the add, to avoid the race if kmalloc
2148 		 * might sleep.
2149 		 */
2150 		atomic_add(size, &sk->sk_omem_alloc);
2151 		mem = kmalloc(size, priority);
2152 		if (mem)
2153 			return mem;
2154 		atomic_sub(size, &sk->sk_omem_alloc);
2155 	}
2156 	return NULL;
2157 }
2158 EXPORT_SYMBOL(sock_kmalloc);
2159 
2160 /* Free an option memory block. Note, we actually want the inline
2161  * here as this allows gcc to detect the nullify and fold away the
2162  * condition entirely.
2163  */
2164 static inline void __sock_kfree_s(struct sock *sk, void *mem, int size,
2165 				  const bool nullify)
2166 {
2167 	if (WARN_ON_ONCE(!mem))
2168 		return;
2169 	if (nullify)
2170 		kzfree(mem);
2171 	else
2172 		kfree(mem);
2173 	atomic_sub(size, &sk->sk_omem_alloc);
2174 }
2175 
2176 void sock_kfree_s(struct sock *sk, void *mem, int size)
2177 {
2178 	__sock_kfree_s(sk, mem, size, false);
2179 }
2180 EXPORT_SYMBOL(sock_kfree_s);
2181 
2182 void sock_kzfree_s(struct sock *sk, void *mem, int size)
2183 {
2184 	__sock_kfree_s(sk, mem, size, true);
2185 }
2186 EXPORT_SYMBOL(sock_kzfree_s);
2187 
2188 /* It is almost wait_for_tcp_memory minus release_sock/lock_sock.
2189    I think, these locks should be removed for datagram sockets.
2190  */
2191 static long sock_wait_for_wmem(struct sock *sk, long timeo)
2192 {
2193 	DEFINE_WAIT(wait);
2194 
2195 	sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
2196 	for (;;) {
2197 		if (!timeo)
2198 			break;
2199 		if (signal_pending(current))
2200 			break;
2201 		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
2202 		prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
2203 		if (refcount_read(&sk->sk_wmem_alloc) < READ_ONCE(sk->sk_sndbuf))
2204 			break;
2205 		if (sk->sk_shutdown & SEND_SHUTDOWN)
2206 			break;
2207 		if (sk->sk_err)
2208 			break;
2209 		timeo = schedule_timeout(timeo);
2210 	}
2211 	finish_wait(sk_sleep(sk), &wait);
2212 	return timeo;
2213 }
2214 
2215 
2216 /*
2217  *	Generic send/receive buffer handlers
2218  */
2219 
2220 struct sk_buff *sock_alloc_send_pskb(struct sock *sk, unsigned long header_len,
2221 				     unsigned long data_len, int noblock,
2222 				     int *errcode, int max_page_order)
2223 {
2224 	struct sk_buff *skb;
2225 	long timeo;
2226 	int err;
2227 
2228 	timeo = sock_sndtimeo(sk, noblock);
2229 	for (;;) {
2230 		err = sock_error(sk);
2231 		if (err != 0)
2232 			goto failure;
2233 
2234 		err = -EPIPE;
2235 		if (sk->sk_shutdown & SEND_SHUTDOWN)
2236 			goto failure;
2237 
2238 		if (sk_wmem_alloc_get(sk) < READ_ONCE(sk->sk_sndbuf))
2239 			break;
2240 
2241 		sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
2242 		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
2243 		err = -EAGAIN;
2244 		if (!timeo)
2245 			goto failure;
2246 		if (signal_pending(current))
2247 			goto interrupted;
2248 		timeo = sock_wait_for_wmem(sk, timeo);
2249 	}
2250 	skb = alloc_skb_with_frags(header_len, data_len, max_page_order,
2251 				   errcode, sk->sk_allocation);
2252 	if (skb)
2253 		skb_set_owner_w(skb, sk);
2254 	return skb;
2255 
2256 interrupted:
2257 	err = sock_intr_errno(timeo);
2258 failure:
2259 	*errcode = err;
2260 	return NULL;
2261 }
2262 EXPORT_SYMBOL(sock_alloc_send_pskb);
2263 
2264 struct sk_buff *sock_alloc_send_skb(struct sock *sk, unsigned long size,
2265 				    int noblock, int *errcode)
2266 {
2267 	return sock_alloc_send_pskb(sk, size, 0, noblock, errcode, 0);
2268 }
2269 EXPORT_SYMBOL(sock_alloc_send_skb);
2270 
2271 int __sock_cmsg_send(struct sock *sk, struct msghdr *msg, struct cmsghdr *cmsg,
2272 		     struct sockcm_cookie *sockc)
2273 {
2274 	u32 tsflags;
2275 
2276 	switch (cmsg->cmsg_type) {
2277 	case SO_MARK:
2278 		if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
2279 			return -EPERM;
2280 		if (cmsg->cmsg_len != CMSG_LEN(sizeof(u32)))
2281 			return -EINVAL;
2282 		sockc->mark = *(u32 *)CMSG_DATA(cmsg);
2283 		break;
2284 	case SO_TIMESTAMPING_OLD:
2285 		if (cmsg->cmsg_len != CMSG_LEN(sizeof(u32)))
2286 			return -EINVAL;
2287 
2288 		tsflags = *(u32 *)CMSG_DATA(cmsg);
2289 		if (tsflags & ~SOF_TIMESTAMPING_TX_RECORD_MASK)
2290 			return -EINVAL;
2291 
2292 		sockc->tsflags &= ~SOF_TIMESTAMPING_TX_RECORD_MASK;
2293 		sockc->tsflags |= tsflags;
2294 		break;
2295 	case SCM_TXTIME:
2296 		if (!sock_flag(sk, SOCK_TXTIME))
2297 			return -EINVAL;
2298 		if (cmsg->cmsg_len != CMSG_LEN(sizeof(u64)))
2299 			return -EINVAL;
2300 		sockc->transmit_time = get_unaligned((u64 *)CMSG_DATA(cmsg));
2301 		break;
2302 	/* SCM_RIGHTS and SCM_CREDENTIALS are semantically in SOL_UNIX. */
2303 	case SCM_RIGHTS:
2304 	case SCM_CREDENTIALS:
2305 		break;
2306 	default:
2307 		return -EINVAL;
2308 	}
2309 	return 0;
2310 }
2311 EXPORT_SYMBOL(__sock_cmsg_send);
2312 
2313 int sock_cmsg_send(struct sock *sk, struct msghdr *msg,
2314 		   struct sockcm_cookie *sockc)
2315 {
2316 	struct cmsghdr *cmsg;
2317 	int ret;
2318 
2319 	for_each_cmsghdr(cmsg, msg) {
2320 		if (!CMSG_OK(msg, cmsg))
2321 			return -EINVAL;
2322 		if (cmsg->cmsg_level != SOL_SOCKET)
2323 			continue;
2324 		ret = __sock_cmsg_send(sk, msg, cmsg, sockc);
2325 		if (ret)
2326 			return ret;
2327 	}
2328 	return 0;
2329 }
2330 EXPORT_SYMBOL(sock_cmsg_send);
2331 
2332 static void sk_enter_memory_pressure(struct sock *sk)
2333 {
2334 	if (!sk->sk_prot->enter_memory_pressure)
2335 		return;
2336 
2337 	sk->sk_prot->enter_memory_pressure(sk);
2338 }
2339 
2340 static void sk_leave_memory_pressure(struct sock *sk)
2341 {
2342 	if (sk->sk_prot->leave_memory_pressure) {
2343 		sk->sk_prot->leave_memory_pressure(sk);
2344 	} else {
2345 		unsigned long *memory_pressure = sk->sk_prot->memory_pressure;
2346 
2347 		if (memory_pressure && READ_ONCE(*memory_pressure))
2348 			WRITE_ONCE(*memory_pressure, 0);
2349 	}
2350 }
2351 
2352 /* On 32bit arches, an skb frag is limited to 2^15 */
2353 #define SKB_FRAG_PAGE_ORDER	get_order(32768)
2354 DEFINE_STATIC_KEY_FALSE(net_high_order_alloc_disable_key);
2355 
2356 /**
2357  * skb_page_frag_refill - check that a page_frag contains enough room
2358  * @sz: minimum size of the fragment we want to get
2359  * @pfrag: pointer to page_frag
2360  * @gfp: priority for memory allocation
2361  *
2362  * Note: While this allocator tries to use high order pages, there is
2363  * no guarantee that allocations succeed. Therefore, @sz MUST be
2364  * less or equal than PAGE_SIZE.
2365  */
2366 bool skb_page_frag_refill(unsigned int sz, struct page_frag *pfrag, gfp_t gfp)
2367 {
2368 	if (pfrag->page) {
2369 		if (page_ref_count(pfrag->page) == 1) {
2370 			pfrag->offset = 0;
2371 			return true;
2372 		}
2373 		if (pfrag->offset + sz <= pfrag->size)
2374 			return true;
2375 		put_page(pfrag->page);
2376 	}
2377 
2378 	pfrag->offset = 0;
2379 	if (SKB_FRAG_PAGE_ORDER &&
2380 	    !static_branch_unlikely(&net_high_order_alloc_disable_key)) {
2381 		/* Avoid direct reclaim but allow kswapd to wake */
2382 		pfrag->page = alloc_pages((gfp & ~__GFP_DIRECT_RECLAIM) |
2383 					  __GFP_COMP | __GFP_NOWARN |
2384 					  __GFP_NORETRY,
2385 					  SKB_FRAG_PAGE_ORDER);
2386 		if (likely(pfrag->page)) {
2387 			pfrag->size = PAGE_SIZE << SKB_FRAG_PAGE_ORDER;
2388 			return true;
2389 		}
2390 	}
2391 	pfrag->page = alloc_page(gfp);
2392 	if (likely(pfrag->page)) {
2393 		pfrag->size = PAGE_SIZE;
2394 		return true;
2395 	}
2396 	return false;
2397 }
2398 EXPORT_SYMBOL(skb_page_frag_refill);
2399 
2400 bool sk_page_frag_refill(struct sock *sk, struct page_frag *pfrag)
2401 {
2402 	if (likely(skb_page_frag_refill(32U, pfrag, sk->sk_allocation)))
2403 		return true;
2404 
2405 	sk_enter_memory_pressure(sk);
2406 	sk_stream_moderate_sndbuf(sk);
2407 	return false;
2408 }
2409 EXPORT_SYMBOL(sk_page_frag_refill);
2410 
2411 static void __lock_sock(struct sock *sk)
2412 	__releases(&sk->sk_lock.slock)
2413 	__acquires(&sk->sk_lock.slock)
2414 {
2415 	DEFINE_WAIT(wait);
2416 
2417 	for (;;) {
2418 		prepare_to_wait_exclusive(&sk->sk_lock.wq, &wait,
2419 					TASK_UNINTERRUPTIBLE);
2420 		spin_unlock_bh(&sk->sk_lock.slock);
2421 		schedule();
2422 		spin_lock_bh(&sk->sk_lock.slock);
2423 		if (!sock_owned_by_user(sk))
2424 			break;
2425 	}
2426 	finish_wait(&sk->sk_lock.wq, &wait);
2427 }
2428 
2429 void __release_sock(struct sock *sk)
2430 	__releases(&sk->sk_lock.slock)
2431 	__acquires(&sk->sk_lock.slock)
2432 {
2433 	struct sk_buff *skb, *next;
2434 
2435 	while ((skb = sk->sk_backlog.head) != NULL) {
2436 		sk->sk_backlog.head = sk->sk_backlog.tail = NULL;
2437 
2438 		spin_unlock_bh(&sk->sk_lock.slock);
2439 
2440 		do {
2441 			next = skb->next;
2442 			prefetch(next);
2443 			WARN_ON_ONCE(skb_dst_is_noref(skb));
2444 			skb_mark_not_on_list(skb);
2445 			sk_backlog_rcv(sk, skb);
2446 
2447 			cond_resched();
2448 
2449 			skb = next;
2450 		} while (skb != NULL);
2451 
2452 		spin_lock_bh(&sk->sk_lock.slock);
2453 	}
2454 
2455 	/*
2456 	 * Doing the zeroing here guarantee we can not loop forever
2457 	 * while a wild producer attempts to flood us.
2458 	 */
2459 	sk->sk_backlog.len = 0;
2460 }
2461 
2462 void __sk_flush_backlog(struct sock *sk)
2463 {
2464 	spin_lock_bh(&sk->sk_lock.slock);
2465 	__release_sock(sk);
2466 	spin_unlock_bh(&sk->sk_lock.slock);
2467 }
2468 
2469 /**
2470  * sk_wait_data - wait for data to arrive at sk_receive_queue
2471  * @sk:    sock to wait on
2472  * @timeo: for how long
2473  * @skb:   last skb seen on sk_receive_queue
2474  *
2475  * Now socket state including sk->sk_err is changed only under lock,
2476  * hence we may omit checks after joining wait queue.
2477  * We check receive queue before schedule() only as optimization;
2478  * it is very likely that release_sock() added new data.
2479  */
2480 int sk_wait_data(struct sock *sk, long *timeo, const struct sk_buff *skb)
2481 {
2482 	DEFINE_WAIT_FUNC(wait, woken_wake_function);
2483 	int rc;
2484 
2485 	add_wait_queue(sk_sleep(sk), &wait);
2486 	sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
2487 	rc = sk_wait_event(sk, timeo, skb_peek_tail(&sk->sk_receive_queue) != skb, &wait);
2488 	sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
2489 	remove_wait_queue(sk_sleep(sk), &wait);
2490 	return rc;
2491 }
2492 EXPORT_SYMBOL(sk_wait_data);
2493 
2494 /**
2495  *	__sk_mem_raise_allocated - increase memory_allocated
2496  *	@sk: socket
2497  *	@size: memory size to allocate
2498  *	@amt: pages to allocate
2499  *	@kind: allocation type
2500  *
2501  *	Similar to __sk_mem_schedule(), but does not update sk_forward_alloc
2502  */
2503 int __sk_mem_raise_allocated(struct sock *sk, int size, int amt, int kind)
2504 {
2505 	struct proto *prot = sk->sk_prot;
2506 	long allocated = sk_memory_allocated_add(sk, amt);
2507 	bool charged = true;
2508 
2509 	if (mem_cgroup_sockets_enabled && sk->sk_memcg &&
2510 	    !(charged = mem_cgroup_charge_skmem(sk->sk_memcg, amt)))
2511 		goto suppress_allocation;
2512 
2513 	/* Under limit. */
2514 	if (allocated <= sk_prot_mem_limits(sk, 0)) {
2515 		sk_leave_memory_pressure(sk);
2516 		return 1;
2517 	}
2518 
2519 	/* Under pressure. */
2520 	if (allocated > sk_prot_mem_limits(sk, 1))
2521 		sk_enter_memory_pressure(sk);
2522 
2523 	/* Over hard limit. */
2524 	if (allocated > sk_prot_mem_limits(sk, 2))
2525 		goto suppress_allocation;
2526 
2527 	/* guarantee minimum buffer size under pressure */
2528 	if (kind == SK_MEM_RECV) {
2529 		if (atomic_read(&sk->sk_rmem_alloc) < sk_get_rmem0(sk, prot))
2530 			return 1;
2531 
2532 	} else { /* SK_MEM_SEND */
2533 		int wmem0 = sk_get_wmem0(sk, prot);
2534 
2535 		if (sk->sk_type == SOCK_STREAM) {
2536 			if (sk->sk_wmem_queued < wmem0)
2537 				return 1;
2538 		} else if (refcount_read(&sk->sk_wmem_alloc) < wmem0) {
2539 				return 1;
2540 		}
2541 	}
2542 
2543 	if (sk_has_memory_pressure(sk)) {
2544 		u64 alloc;
2545 
2546 		if (!sk_under_memory_pressure(sk))
2547 			return 1;
2548 		alloc = sk_sockets_allocated_read_positive(sk);
2549 		if (sk_prot_mem_limits(sk, 2) > alloc *
2550 		    sk_mem_pages(sk->sk_wmem_queued +
2551 				 atomic_read(&sk->sk_rmem_alloc) +
2552 				 sk->sk_forward_alloc))
2553 			return 1;
2554 	}
2555 
2556 suppress_allocation:
2557 
2558 	if (kind == SK_MEM_SEND && sk->sk_type == SOCK_STREAM) {
2559 		sk_stream_moderate_sndbuf(sk);
2560 
2561 		/* Fail only if socket is _under_ its sndbuf.
2562 		 * In this case we cannot block, so that we have to fail.
2563 		 */
2564 		if (sk->sk_wmem_queued + size >= sk->sk_sndbuf)
2565 			return 1;
2566 	}
2567 
2568 	if (kind == SK_MEM_SEND || (kind == SK_MEM_RECV && charged))
2569 		trace_sock_exceed_buf_limit(sk, prot, allocated, kind);
2570 
2571 	sk_memory_allocated_sub(sk, amt);
2572 
2573 	if (mem_cgroup_sockets_enabled && sk->sk_memcg)
2574 		mem_cgroup_uncharge_skmem(sk->sk_memcg, amt);
2575 
2576 	return 0;
2577 }
2578 EXPORT_SYMBOL(__sk_mem_raise_allocated);
2579 
2580 /**
2581  *	__sk_mem_schedule - increase sk_forward_alloc and memory_allocated
2582  *	@sk: socket
2583  *	@size: memory size to allocate
2584  *	@kind: allocation type
2585  *
2586  *	If kind is SK_MEM_SEND, it means wmem allocation. Otherwise it means
2587  *	rmem allocation. This function assumes that protocols which have
2588  *	memory_pressure use sk_wmem_queued as write buffer accounting.
2589  */
2590 int __sk_mem_schedule(struct sock *sk, int size, int kind)
2591 {
2592 	int ret, amt = sk_mem_pages(size);
2593 
2594 	sk->sk_forward_alloc += amt << SK_MEM_QUANTUM_SHIFT;
2595 	ret = __sk_mem_raise_allocated(sk, size, amt, kind);
2596 	if (!ret)
2597 		sk->sk_forward_alloc -= amt << SK_MEM_QUANTUM_SHIFT;
2598 	return ret;
2599 }
2600 EXPORT_SYMBOL(__sk_mem_schedule);
2601 
2602 /**
2603  *	__sk_mem_reduce_allocated - reclaim memory_allocated
2604  *	@sk: socket
2605  *	@amount: number of quanta
2606  *
2607  *	Similar to __sk_mem_reclaim(), but does not update sk_forward_alloc
2608  */
2609 void __sk_mem_reduce_allocated(struct sock *sk, int amount)
2610 {
2611 	sk_memory_allocated_sub(sk, amount);
2612 
2613 	if (mem_cgroup_sockets_enabled && sk->sk_memcg)
2614 		mem_cgroup_uncharge_skmem(sk->sk_memcg, amount);
2615 
2616 	if (sk_under_memory_pressure(sk) &&
2617 	    (sk_memory_allocated(sk) < sk_prot_mem_limits(sk, 0)))
2618 		sk_leave_memory_pressure(sk);
2619 }
2620 EXPORT_SYMBOL(__sk_mem_reduce_allocated);
2621 
2622 /**
2623  *	__sk_mem_reclaim - reclaim sk_forward_alloc and memory_allocated
2624  *	@sk: socket
2625  *	@amount: number of bytes (rounded down to a SK_MEM_QUANTUM multiple)
2626  */
2627 void __sk_mem_reclaim(struct sock *sk, int amount)
2628 {
2629 	amount >>= SK_MEM_QUANTUM_SHIFT;
2630 	sk->sk_forward_alloc -= amount << SK_MEM_QUANTUM_SHIFT;
2631 	__sk_mem_reduce_allocated(sk, amount);
2632 }
2633 EXPORT_SYMBOL(__sk_mem_reclaim);
2634 
2635 int sk_set_peek_off(struct sock *sk, int val)
2636 {
2637 	sk->sk_peek_off = val;
2638 	return 0;
2639 }
2640 EXPORT_SYMBOL_GPL(sk_set_peek_off);
2641 
2642 /*
2643  * Set of default routines for initialising struct proto_ops when
2644  * the protocol does not support a particular function. In certain
2645  * cases where it makes no sense for a protocol to have a "do nothing"
2646  * function, some default processing is provided.
2647  */
2648 
2649 int sock_no_bind(struct socket *sock, struct sockaddr *saddr, int len)
2650 {
2651 	return -EOPNOTSUPP;
2652 }
2653 EXPORT_SYMBOL(sock_no_bind);
2654 
2655 int sock_no_connect(struct socket *sock, struct sockaddr *saddr,
2656 		    int len, int flags)
2657 {
2658 	return -EOPNOTSUPP;
2659 }
2660 EXPORT_SYMBOL(sock_no_connect);
2661 
2662 int sock_no_socketpair(struct socket *sock1, struct socket *sock2)
2663 {
2664 	return -EOPNOTSUPP;
2665 }
2666 EXPORT_SYMBOL(sock_no_socketpair);
2667 
2668 int sock_no_accept(struct socket *sock, struct socket *newsock, int flags,
2669 		   bool kern)
2670 {
2671 	return -EOPNOTSUPP;
2672 }
2673 EXPORT_SYMBOL(sock_no_accept);
2674 
2675 int sock_no_getname(struct socket *sock, struct sockaddr *saddr,
2676 		    int peer)
2677 {
2678 	return -EOPNOTSUPP;
2679 }
2680 EXPORT_SYMBOL(sock_no_getname);
2681 
2682 int sock_no_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
2683 {
2684 	return -EOPNOTSUPP;
2685 }
2686 EXPORT_SYMBOL(sock_no_ioctl);
2687 
2688 int sock_no_listen(struct socket *sock, int backlog)
2689 {
2690 	return -EOPNOTSUPP;
2691 }
2692 EXPORT_SYMBOL(sock_no_listen);
2693 
2694 int sock_no_shutdown(struct socket *sock, int how)
2695 {
2696 	return -EOPNOTSUPP;
2697 }
2698 EXPORT_SYMBOL(sock_no_shutdown);
2699 
2700 int sock_no_setsockopt(struct socket *sock, int level, int optname,
2701 		    char __user *optval, unsigned int optlen)
2702 {
2703 	return -EOPNOTSUPP;
2704 }
2705 EXPORT_SYMBOL(sock_no_setsockopt);
2706 
2707 int sock_no_getsockopt(struct socket *sock, int level, int optname,
2708 		    char __user *optval, int __user *optlen)
2709 {
2710 	return -EOPNOTSUPP;
2711 }
2712 EXPORT_SYMBOL(sock_no_getsockopt);
2713 
2714 int sock_no_sendmsg(struct socket *sock, struct msghdr *m, size_t len)
2715 {
2716 	return -EOPNOTSUPP;
2717 }
2718 EXPORT_SYMBOL(sock_no_sendmsg);
2719 
2720 int sock_no_sendmsg_locked(struct sock *sk, struct msghdr *m, size_t len)
2721 {
2722 	return -EOPNOTSUPP;
2723 }
2724 EXPORT_SYMBOL(sock_no_sendmsg_locked);
2725 
2726 int sock_no_recvmsg(struct socket *sock, struct msghdr *m, size_t len,
2727 		    int flags)
2728 {
2729 	return -EOPNOTSUPP;
2730 }
2731 EXPORT_SYMBOL(sock_no_recvmsg);
2732 
2733 int sock_no_mmap(struct file *file, struct socket *sock, struct vm_area_struct *vma)
2734 {
2735 	/* Mirror missing mmap method error code */
2736 	return -ENODEV;
2737 }
2738 EXPORT_SYMBOL(sock_no_mmap);
2739 
2740 ssize_t sock_no_sendpage(struct socket *sock, struct page *page, int offset, size_t size, int flags)
2741 {
2742 	ssize_t res;
2743 	struct msghdr msg = {.msg_flags = flags};
2744 	struct kvec iov;
2745 	char *kaddr = kmap(page);
2746 	iov.iov_base = kaddr + offset;
2747 	iov.iov_len = size;
2748 	res = kernel_sendmsg(sock, &msg, &iov, 1, size);
2749 	kunmap(page);
2750 	return res;
2751 }
2752 EXPORT_SYMBOL(sock_no_sendpage);
2753 
2754 ssize_t sock_no_sendpage_locked(struct sock *sk, struct page *page,
2755 				int offset, size_t size, int flags)
2756 {
2757 	ssize_t res;
2758 	struct msghdr msg = {.msg_flags = flags};
2759 	struct kvec iov;
2760 	char *kaddr = kmap(page);
2761 
2762 	iov.iov_base = kaddr + offset;
2763 	iov.iov_len = size;
2764 	res = kernel_sendmsg_locked(sk, &msg, &iov, 1, size);
2765 	kunmap(page);
2766 	return res;
2767 }
2768 EXPORT_SYMBOL(sock_no_sendpage_locked);
2769 
2770 /*
2771  *	Default Socket Callbacks
2772  */
2773 
2774 static void sock_def_wakeup(struct sock *sk)
2775 {
2776 	struct socket_wq *wq;
2777 
2778 	rcu_read_lock();
2779 	wq = rcu_dereference(sk->sk_wq);
2780 	if (skwq_has_sleeper(wq))
2781 		wake_up_interruptible_all(&wq->wait);
2782 	rcu_read_unlock();
2783 }
2784 
2785 static void sock_def_error_report(struct sock *sk)
2786 {
2787 	struct socket_wq *wq;
2788 
2789 	rcu_read_lock();
2790 	wq = rcu_dereference(sk->sk_wq);
2791 	if (skwq_has_sleeper(wq))
2792 		wake_up_interruptible_poll(&wq->wait, EPOLLERR);
2793 	sk_wake_async(sk, SOCK_WAKE_IO, POLL_ERR);
2794 	rcu_read_unlock();
2795 }
2796 
2797 void sock_def_readable(struct sock *sk)
2798 {
2799 	struct socket_wq *wq;
2800 
2801 	rcu_read_lock();
2802 	wq = rcu_dereference(sk->sk_wq);
2803 	if (skwq_has_sleeper(wq))
2804 		wake_up_interruptible_sync_poll(&wq->wait, EPOLLIN | EPOLLPRI |
2805 						EPOLLRDNORM | EPOLLRDBAND);
2806 	sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
2807 	rcu_read_unlock();
2808 }
2809 
2810 static void sock_def_write_space(struct sock *sk)
2811 {
2812 	struct socket_wq *wq;
2813 
2814 	rcu_read_lock();
2815 
2816 	/* Do not wake up a writer until he can make "significant"
2817 	 * progress.  --DaveM
2818 	 */
2819 	if ((refcount_read(&sk->sk_wmem_alloc) << 1) <= READ_ONCE(sk->sk_sndbuf)) {
2820 		wq = rcu_dereference(sk->sk_wq);
2821 		if (skwq_has_sleeper(wq))
2822 			wake_up_interruptible_sync_poll(&wq->wait, EPOLLOUT |
2823 						EPOLLWRNORM | EPOLLWRBAND);
2824 
2825 		/* Should agree with poll, otherwise some programs break */
2826 		if (sock_writeable(sk))
2827 			sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
2828 	}
2829 
2830 	rcu_read_unlock();
2831 }
2832 
2833 static void sock_def_destruct(struct sock *sk)
2834 {
2835 }
2836 
2837 void sk_send_sigurg(struct sock *sk)
2838 {
2839 	if (sk->sk_socket && sk->sk_socket->file)
2840 		if (send_sigurg(&sk->sk_socket->file->f_owner))
2841 			sk_wake_async(sk, SOCK_WAKE_URG, POLL_PRI);
2842 }
2843 EXPORT_SYMBOL(sk_send_sigurg);
2844 
2845 void sk_reset_timer(struct sock *sk, struct timer_list* timer,
2846 		    unsigned long expires)
2847 {
2848 	if (!mod_timer(timer, expires))
2849 		sock_hold(sk);
2850 }
2851 EXPORT_SYMBOL(sk_reset_timer);
2852 
2853 void sk_stop_timer(struct sock *sk, struct timer_list* timer)
2854 {
2855 	if (del_timer(timer))
2856 		__sock_put(sk);
2857 }
2858 EXPORT_SYMBOL(sk_stop_timer);
2859 
2860 void sock_init_data(struct socket *sock, struct sock *sk)
2861 {
2862 	sk_init_common(sk);
2863 	sk->sk_send_head	=	NULL;
2864 
2865 	timer_setup(&sk->sk_timer, NULL, 0);
2866 
2867 	sk->sk_allocation	=	GFP_KERNEL;
2868 	sk->sk_rcvbuf		=	sysctl_rmem_default;
2869 	sk->sk_sndbuf		=	sysctl_wmem_default;
2870 	sk->sk_state		=	TCP_CLOSE;
2871 	sk_set_socket(sk, sock);
2872 
2873 	sock_set_flag(sk, SOCK_ZAPPED);
2874 
2875 	if (sock) {
2876 		sk->sk_type	=	sock->type;
2877 		RCU_INIT_POINTER(sk->sk_wq, &sock->wq);
2878 		sock->sk	=	sk;
2879 		sk->sk_uid	=	SOCK_INODE(sock)->i_uid;
2880 	} else {
2881 		RCU_INIT_POINTER(sk->sk_wq, NULL);
2882 		sk->sk_uid	=	make_kuid(sock_net(sk)->user_ns, 0);
2883 	}
2884 
2885 	rwlock_init(&sk->sk_callback_lock);
2886 	if (sk->sk_kern_sock)
2887 		lockdep_set_class_and_name(
2888 			&sk->sk_callback_lock,
2889 			af_kern_callback_keys + sk->sk_family,
2890 			af_family_kern_clock_key_strings[sk->sk_family]);
2891 	else
2892 		lockdep_set_class_and_name(
2893 			&sk->sk_callback_lock,
2894 			af_callback_keys + sk->sk_family,
2895 			af_family_clock_key_strings[sk->sk_family]);
2896 
2897 	sk->sk_state_change	=	sock_def_wakeup;
2898 	sk->sk_data_ready	=	sock_def_readable;
2899 	sk->sk_write_space	=	sock_def_write_space;
2900 	sk->sk_error_report	=	sock_def_error_report;
2901 	sk->sk_destruct		=	sock_def_destruct;
2902 
2903 	sk->sk_frag.page	=	NULL;
2904 	sk->sk_frag.offset	=	0;
2905 	sk->sk_peek_off		=	-1;
2906 
2907 	sk->sk_peer_pid 	=	NULL;
2908 	sk->sk_peer_cred	=	NULL;
2909 	sk->sk_write_pending	=	0;
2910 	sk->sk_rcvlowat		=	1;
2911 	sk->sk_rcvtimeo		=	MAX_SCHEDULE_TIMEOUT;
2912 	sk->sk_sndtimeo		=	MAX_SCHEDULE_TIMEOUT;
2913 
2914 	sk->sk_stamp = SK_DEFAULT_STAMP;
2915 #if BITS_PER_LONG==32
2916 	seqlock_init(&sk->sk_stamp_seq);
2917 #endif
2918 	atomic_set(&sk->sk_zckey, 0);
2919 
2920 #ifdef CONFIG_NET_RX_BUSY_POLL
2921 	sk->sk_napi_id		=	0;
2922 	sk->sk_ll_usec		=	sysctl_net_busy_read;
2923 #endif
2924 
2925 	sk->sk_max_pacing_rate = ~0UL;
2926 	sk->sk_pacing_rate = ~0UL;
2927 	WRITE_ONCE(sk->sk_pacing_shift, 10);
2928 	sk->sk_incoming_cpu = -1;
2929 
2930 	sk_rx_queue_clear(sk);
2931 	/*
2932 	 * Before updating sk_refcnt, we must commit prior changes to memory
2933 	 * (Documentation/RCU/rculist_nulls.txt for details)
2934 	 */
2935 	smp_wmb();
2936 	refcount_set(&sk->sk_refcnt, 1);
2937 	atomic_set(&sk->sk_drops, 0);
2938 }
2939 EXPORT_SYMBOL(sock_init_data);
2940 
2941 void lock_sock_nested(struct sock *sk, int subclass)
2942 {
2943 	might_sleep();
2944 	spin_lock_bh(&sk->sk_lock.slock);
2945 	if (sk->sk_lock.owned)
2946 		__lock_sock(sk);
2947 	sk->sk_lock.owned = 1;
2948 	spin_unlock(&sk->sk_lock.slock);
2949 	/*
2950 	 * The sk_lock has mutex_lock() semantics here:
2951 	 */
2952 	mutex_acquire(&sk->sk_lock.dep_map, subclass, 0, _RET_IP_);
2953 	local_bh_enable();
2954 }
2955 EXPORT_SYMBOL(lock_sock_nested);
2956 
2957 void release_sock(struct sock *sk)
2958 {
2959 	spin_lock_bh(&sk->sk_lock.slock);
2960 	if (sk->sk_backlog.tail)
2961 		__release_sock(sk);
2962 
2963 	/* Warning : release_cb() might need to release sk ownership,
2964 	 * ie call sock_release_ownership(sk) before us.
2965 	 */
2966 	if (sk->sk_prot->release_cb)
2967 		sk->sk_prot->release_cb(sk);
2968 
2969 	sock_release_ownership(sk);
2970 	if (waitqueue_active(&sk->sk_lock.wq))
2971 		wake_up(&sk->sk_lock.wq);
2972 	spin_unlock_bh(&sk->sk_lock.slock);
2973 }
2974 EXPORT_SYMBOL(release_sock);
2975 
2976 /**
2977  * lock_sock_fast - fast version of lock_sock
2978  * @sk: socket
2979  *
2980  * This version should be used for very small section, where process wont block
2981  * return false if fast path is taken:
2982  *
2983  *   sk_lock.slock locked, owned = 0, BH disabled
2984  *
2985  * return true if slow path is taken:
2986  *
2987  *   sk_lock.slock unlocked, owned = 1, BH enabled
2988  */
2989 bool lock_sock_fast(struct sock *sk)
2990 {
2991 	might_sleep();
2992 	spin_lock_bh(&sk->sk_lock.slock);
2993 
2994 	if (!sk->sk_lock.owned)
2995 		/*
2996 		 * Note : We must disable BH
2997 		 */
2998 		return false;
2999 
3000 	__lock_sock(sk);
3001 	sk->sk_lock.owned = 1;
3002 	spin_unlock(&sk->sk_lock.slock);
3003 	/*
3004 	 * The sk_lock has mutex_lock() semantics here:
3005 	 */
3006 	mutex_acquire(&sk->sk_lock.dep_map, 0, 0, _RET_IP_);
3007 	local_bh_enable();
3008 	return true;
3009 }
3010 EXPORT_SYMBOL(lock_sock_fast);
3011 
3012 int sock_gettstamp(struct socket *sock, void __user *userstamp,
3013 		   bool timeval, bool time32)
3014 {
3015 	struct sock *sk = sock->sk;
3016 	struct timespec64 ts;
3017 
3018 	sock_enable_timestamp(sk, SOCK_TIMESTAMP);
3019 	ts = ktime_to_timespec64(sock_read_timestamp(sk));
3020 	if (ts.tv_sec == -1)
3021 		return -ENOENT;
3022 	if (ts.tv_sec == 0) {
3023 		ktime_t kt = ktime_get_real();
3024 		sock_write_timestamp(sk, kt);
3025 		ts = ktime_to_timespec64(kt);
3026 	}
3027 
3028 	if (timeval)
3029 		ts.tv_nsec /= 1000;
3030 
3031 #ifdef CONFIG_COMPAT_32BIT_TIME
3032 	if (time32)
3033 		return put_old_timespec32(&ts, userstamp);
3034 #endif
3035 #ifdef CONFIG_SPARC64
3036 	/* beware of padding in sparc64 timeval */
3037 	if (timeval && !in_compat_syscall()) {
3038 		struct __kernel_old_timeval __user tv = {
3039 			.tv_sec = ts.tv_sec,
3040 			.tv_usec = ts.tv_nsec,
3041 		};
3042 		if (copy_to_user(userstamp, &tv, sizeof(tv)))
3043 			return -EFAULT;
3044 		return 0;
3045 	}
3046 #endif
3047 	return put_timespec64(&ts, userstamp);
3048 }
3049 EXPORT_SYMBOL(sock_gettstamp);
3050 
3051 void sock_enable_timestamp(struct sock *sk, enum sock_flags flag)
3052 {
3053 	if (!sock_flag(sk, flag)) {
3054 		unsigned long previous_flags = sk->sk_flags;
3055 
3056 		sock_set_flag(sk, flag);
3057 		/*
3058 		 * we just set one of the two flags which require net
3059 		 * time stamping, but time stamping might have been on
3060 		 * already because of the other one
3061 		 */
3062 		if (sock_needs_netstamp(sk) &&
3063 		    !(previous_flags & SK_FLAGS_TIMESTAMP))
3064 			net_enable_timestamp();
3065 	}
3066 }
3067 
3068 int sock_recv_errqueue(struct sock *sk, struct msghdr *msg, int len,
3069 		       int level, int type)
3070 {
3071 	struct sock_exterr_skb *serr;
3072 	struct sk_buff *skb;
3073 	int copied, err;
3074 
3075 	err = -EAGAIN;
3076 	skb = sock_dequeue_err_skb(sk);
3077 	if (skb == NULL)
3078 		goto out;
3079 
3080 	copied = skb->len;
3081 	if (copied > len) {
3082 		msg->msg_flags |= MSG_TRUNC;
3083 		copied = len;
3084 	}
3085 	err = skb_copy_datagram_msg(skb, 0, msg, copied);
3086 	if (err)
3087 		goto out_free_skb;
3088 
3089 	sock_recv_timestamp(msg, sk, skb);
3090 
3091 	serr = SKB_EXT_ERR(skb);
3092 	put_cmsg(msg, level, type, sizeof(serr->ee), &serr->ee);
3093 
3094 	msg->msg_flags |= MSG_ERRQUEUE;
3095 	err = copied;
3096 
3097 out_free_skb:
3098 	kfree_skb(skb);
3099 out:
3100 	return err;
3101 }
3102 EXPORT_SYMBOL(sock_recv_errqueue);
3103 
3104 /*
3105  *	Get a socket option on an socket.
3106  *
3107  *	FIX: POSIX 1003.1g is very ambiguous here. It states that
3108  *	asynchronous errors should be reported by getsockopt. We assume
3109  *	this means if you specify SO_ERROR (otherwise whats the point of it).
3110  */
3111 int 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 	return sk->sk_prot->getsockopt(sk, level, optname, optval, optlen);
3117 }
3118 EXPORT_SYMBOL(sock_common_getsockopt);
3119 
3120 #ifdef CONFIG_COMPAT
3121 int compat_sock_common_getsockopt(struct socket *sock, int level, int optname,
3122 				  char __user *optval, int __user *optlen)
3123 {
3124 	struct sock *sk = sock->sk;
3125 
3126 	if (sk->sk_prot->compat_getsockopt != NULL)
3127 		return sk->sk_prot->compat_getsockopt(sk, level, optname,
3128 						      optval, optlen);
3129 	return sk->sk_prot->getsockopt(sk, level, optname, optval, optlen);
3130 }
3131 EXPORT_SYMBOL(compat_sock_common_getsockopt);
3132 #endif
3133 
3134 int sock_common_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
3135 			int flags)
3136 {
3137 	struct sock *sk = sock->sk;
3138 	int addr_len = 0;
3139 	int err;
3140 
3141 	err = sk->sk_prot->recvmsg(sk, msg, size, flags & MSG_DONTWAIT,
3142 				   flags & ~MSG_DONTWAIT, &addr_len);
3143 	if (err >= 0)
3144 		msg->msg_namelen = addr_len;
3145 	return err;
3146 }
3147 EXPORT_SYMBOL(sock_common_recvmsg);
3148 
3149 /*
3150  *	Set socket options on an inet socket.
3151  */
3152 int 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 	return sk->sk_prot->setsockopt(sk, level, optname, optval, optlen);
3158 }
3159 EXPORT_SYMBOL(sock_common_setsockopt);
3160 
3161 #ifdef CONFIG_COMPAT
3162 int compat_sock_common_setsockopt(struct socket *sock, int level, int optname,
3163 				  char __user *optval, unsigned int optlen)
3164 {
3165 	struct sock *sk = sock->sk;
3166 
3167 	if (sk->sk_prot->compat_setsockopt != NULL)
3168 		return sk->sk_prot->compat_setsockopt(sk, level, optname,
3169 						      optval, optlen);
3170 	return sk->sk_prot->setsockopt(sk, level, optname, optval, optlen);
3171 }
3172 EXPORT_SYMBOL(compat_sock_common_setsockopt);
3173 #endif
3174 
3175 void sk_common_release(struct sock *sk)
3176 {
3177 	if (sk->sk_prot->destroy)
3178 		sk->sk_prot->destroy(sk);
3179 
3180 	/*
3181 	 * Observation: when sock_common_release is called, processes have
3182 	 * no access to socket. But net still has.
3183 	 * Step one, detach it from networking:
3184 	 *
3185 	 * A. Remove from hash tables.
3186 	 */
3187 
3188 	sk->sk_prot->unhash(sk);
3189 
3190 	/*
3191 	 * In this point socket cannot receive new packets, but it is possible
3192 	 * that some packets are in flight because some CPU runs receiver and
3193 	 * did hash table lookup before we unhashed socket. They will achieve
3194 	 * receive queue and will be purged by socket destructor.
3195 	 *
3196 	 * Also we still have packets pending on receive queue and probably,
3197 	 * our own packets waiting in device queues. sock_destroy will drain
3198 	 * receive queue, but transmitted packets will delay socket destruction
3199 	 * until the last reference will be released.
3200 	 */
3201 
3202 	sock_orphan(sk);
3203 
3204 	xfrm_sk_free_policy(sk);
3205 
3206 	sk_refcnt_debug_release(sk);
3207 
3208 	sock_put(sk);
3209 }
3210 EXPORT_SYMBOL(sk_common_release);
3211 
3212 void sk_get_meminfo(const struct sock *sk, u32 *mem)
3213 {
3214 	memset(mem, 0, sizeof(*mem) * SK_MEMINFO_VARS);
3215 
3216 	mem[SK_MEMINFO_RMEM_ALLOC] = sk_rmem_alloc_get(sk);
3217 	mem[SK_MEMINFO_RCVBUF] = READ_ONCE(sk->sk_rcvbuf);
3218 	mem[SK_MEMINFO_WMEM_ALLOC] = sk_wmem_alloc_get(sk);
3219 	mem[SK_MEMINFO_SNDBUF] = READ_ONCE(sk->sk_sndbuf);
3220 	mem[SK_MEMINFO_FWD_ALLOC] = sk->sk_forward_alloc;
3221 	mem[SK_MEMINFO_WMEM_QUEUED] = READ_ONCE(sk->sk_wmem_queued);
3222 	mem[SK_MEMINFO_OPTMEM] = atomic_read(&sk->sk_omem_alloc);
3223 	mem[SK_MEMINFO_BACKLOG] = READ_ONCE(sk->sk_backlog.len);
3224 	mem[SK_MEMINFO_DROPS] = atomic_read(&sk->sk_drops);
3225 }
3226 
3227 #ifdef CONFIG_PROC_FS
3228 #define PROTO_INUSE_NR	64	/* should be enough for the first time */
3229 struct prot_inuse {
3230 	int val[PROTO_INUSE_NR];
3231 };
3232 
3233 static DECLARE_BITMAP(proto_inuse_idx, PROTO_INUSE_NR);
3234 
3235 void sock_prot_inuse_add(struct net *net, struct proto *prot, int val)
3236 {
3237 	__this_cpu_add(net->core.prot_inuse->val[prot->inuse_idx], val);
3238 }
3239 EXPORT_SYMBOL_GPL(sock_prot_inuse_add);
3240 
3241 int sock_prot_inuse_get(struct net *net, struct proto *prot)
3242 {
3243 	int cpu, idx = prot->inuse_idx;
3244 	int res = 0;
3245 
3246 	for_each_possible_cpu(cpu)
3247 		res += per_cpu_ptr(net->core.prot_inuse, cpu)->val[idx];
3248 
3249 	return res >= 0 ? res : 0;
3250 }
3251 EXPORT_SYMBOL_GPL(sock_prot_inuse_get);
3252 
3253 static void sock_inuse_add(struct net *net, int val)
3254 {
3255 	this_cpu_add(*net->core.sock_inuse, val);
3256 }
3257 
3258 int sock_inuse_get(struct net *net)
3259 {
3260 	int cpu, res = 0;
3261 
3262 	for_each_possible_cpu(cpu)
3263 		res += *per_cpu_ptr(net->core.sock_inuse, cpu);
3264 
3265 	return res;
3266 }
3267 
3268 EXPORT_SYMBOL_GPL(sock_inuse_get);
3269 
3270 static int __net_init sock_inuse_init_net(struct net *net)
3271 {
3272 	net->core.prot_inuse = alloc_percpu(struct prot_inuse);
3273 	if (net->core.prot_inuse == NULL)
3274 		return -ENOMEM;
3275 
3276 	net->core.sock_inuse = alloc_percpu(int);
3277 	if (net->core.sock_inuse == NULL)
3278 		goto out;
3279 
3280 	return 0;
3281 
3282 out:
3283 	free_percpu(net->core.prot_inuse);
3284 	return -ENOMEM;
3285 }
3286 
3287 static void __net_exit sock_inuse_exit_net(struct net *net)
3288 {
3289 	free_percpu(net->core.prot_inuse);
3290 	free_percpu(net->core.sock_inuse);
3291 }
3292 
3293 static struct pernet_operations net_inuse_ops = {
3294 	.init = sock_inuse_init_net,
3295 	.exit = sock_inuse_exit_net,
3296 };
3297 
3298 static __init int net_inuse_init(void)
3299 {
3300 	if (register_pernet_subsys(&net_inuse_ops))
3301 		panic("Cannot initialize net inuse counters");
3302 
3303 	return 0;
3304 }
3305 
3306 core_initcall(net_inuse_init);
3307 
3308 static int assign_proto_idx(struct proto *prot)
3309 {
3310 	prot->inuse_idx = find_first_zero_bit(proto_inuse_idx, PROTO_INUSE_NR);
3311 
3312 	if (unlikely(prot->inuse_idx == PROTO_INUSE_NR - 1)) {
3313 		pr_err("PROTO_INUSE_NR exhausted\n");
3314 		return -ENOSPC;
3315 	}
3316 
3317 	set_bit(prot->inuse_idx, proto_inuse_idx);
3318 	return 0;
3319 }
3320 
3321 static void release_proto_idx(struct proto *prot)
3322 {
3323 	if (prot->inuse_idx != PROTO_INUSE_NR - 1)
3324 		clear_bit(prot->inuse_idx, proto_inuse_idx);
3325 }
3326 #else
3327 static inline int assign_proto_idx(struct proto *prot)
3328 {
3329 	return 0;
3330 }
3331 
3332 static inline void release_proto_idx(struct proto *prot)
3333 {
3334 }
3335 
3336 static void sock_inuse_add(struct net *net, int val)
3337 {
3338 }
3339 #endif
3340 
3341 static void req_prot_cleanup(struct request_sock_ops *rsk_prot)
3342 {
3343 	if (!rsk_prot)
3344 		return;
3345 	kfree(rsk_prot->slab_name);
3346 	rsk_prot->slab_name = NULL;
3347 	kmem_cache_destroy(rsk_prot->slab);
3348 	rsk_prot->slab = NULL;
3349 }
3350 
3351 static int req_prot_init(const struct proto *prot)
3352 {
3353 	struct request_sock_ops *rsk_prot = prot->rsk_prot;
3354 
3355 	if (!rsk_prot)
3356 		return 0;
3357 
3358 	rsk_prot->slab_name = kasprintf(GFP_KERNEL, "request_sock_%s",
3359 					prot->name);
3360 	if (!rsk_prot->slab_name)
3361 		return -ENOMEM;
3362 
3363 	rsk_prot->slab = kmem_cache_create(rsk_prot->slab_name,
3364 					   rsk_prot->obj_size, 0,
3365 					   SLAB_ACCOUNT | prot->slab_flags,
3366 					   NULL);
3367 
3368 	if (!rsk_prot->slab) {
3369 		pr_crit("%s: Can't create request sock SLAB cache!\n",
3370 			prot->name);
3371 		return -ENOMEM;
3372 	}
3373 	return 0;
3374 }
3375 
3376 int proto_register(struct proto *prot, int alloc_slab)
3377 {
3378 	int ret = -ENOBUFS;
3379 
3380 	if (alloc_slab) {
3381 		prot->slab = kmem_cache_create_usercopy(prot->name,
3382 					prot->obj_size, 0,
3383 					SLAB_HWCACHE_ALIGN | SLAB_ACCOUNT |
3384 					prot->slab_flags,
3385 					prot->useroffset, prot->usersize,
3386 					NULL);
3387 
3388 		if (prot->slab == NULL) {
3389 			pr_crit("%s: Can't create sock SLAB cache!\n",
3390 				prot->name);
3391 			goto out;
3392 		}
3393 
3394 		if (req_prot_init(prot))
3395 			goto out_free_request_sock_slab;
3396 
3397 		if (prot->twsk_prot != NULL) {
3398 			prot->twsk_prot->twsk_slab_name = kasprintf(GFP_KERNEL, "tw_sock_%s", prot->name);
3399 
3400 			if (prot->twsk_prot->twsk_slab_name == NULL)
3401 				goto out_free_request_sock_slab;
3402 
3403 			prot->twsk_prot->twsk_slab =
3404 				kmem_cache_create(prot->twsk_prot->twsk_slab_name,
3405 						  prot->twsk_prot->twsk_obj_size,
3406 						  0,
3407 						  SLAB_ACCOUNT |
3408 						  prot->slab_flags,
3409 						  NULL);
3410 			if (prot->twsk_prot->twsk_slab == NULL)
3411 				goto out_free_timewait_sock_slab_name;
3412 		}
3413 	}
3414 
3415 	mutex_lock(&proto_list_mutex);
3416 	ret = assign_proto_idx(prot);
3417 	if (ret) {
3418 		mutex_unlock(&proto_list_mutex);
3419 		goto out_free_timewait_sock_slab_name;
3420 	}
3421 	list_add(&prot->node, &proto_list);
3422 	mutex_unlock(&proto_list_mutex);
3423 	return ret;
3424 
3425 out_free_timewait_sock_slab_name:
3426 	if (alloc_slab && prot->twsk_prot)
3427 		kfree(prot->twsk_prot->twsk_slab_name);
3428 out_free_request_sock_slab:
3429 	if (alloc_slab) {
3430 		req_prot_cleanup(prot->rsk_prot);
3431 
3432 		kmem_cache_destroy(prot->slab);
3433 		prot->slab = NULL;
3434 	}
3435 out:
3436 	return ret;
3437 }
3438 EXPORT_SYMBOL(proto_register);
3439 
3440 void proto_unregister(struct proto *prot)
3441 {
3442 	mutex_lock(&proto_list_mutex);
3443 	release_proto_idx(prot);
3444 	list_del(&prot->node);
3445 	mutex_unlock(&proto_list_mutex);
3446 
3447 	kmem_cache_destroy(prot->slab);
3448 	prot->slab = NULL;
3449 
3450 	req_prot_cleanup(prot->rsk_prot);
3451 
3452 	if (prot->twsk_prot != NULL && prot->twsk_prot->twsk_slab != NULL) {
3453 		kmem_cache_destroy(prot->twsk_prot->twsk_slab);
3454 		kfree(prot->twsk_prot->twsk_slab_name);
3455 		prot->twsk_prot->twsk_slab = NULL;
3456 	}
3457 }
3458 EXPORT_SYMBOL(proto_unregister);
3459 
3460 int sock_load_diag_module(int family, int protocol)
3461 {
3462 	if (!protocol) {
3463 		if (!sock_is_registered(family))
3464 			return -ENOENT;
3465 
3466 		return request_module("net-pf-%d-proto-%d-type-%d", PF_NETLINK,
3467 				      NETLINK_SOCK_DIAG, family);
3468 	}
3469 
3470 #ifdef CONFIG_INET
3471 	if (family == AF_INET &&
3472 	    protocol != IPPROTO_RAW &&
3473 	    !rcu_access_pointer(inet_protos[protocol]))
3474 		return -ENOENT;
3475 #endif
3476 
3477 	return request_module("net-pf-%d-proto-%d-type-%d-%d", PF_NETLINK,
3478 			      NETLINK_SOCK_DIAG, family, protocol);
3479 }
3480 EXPORT_SYMBOL(sock_load_diag_module);
3481 
3482 #ifdef CONFIG_PROC_FS
3483 static void *proto_seq_start(struct seq_file *seq, loff_t *pos)
3484 	__acquires(proto_list_mutex)
3485 {
3486 	mutex_lock(&proto_list_mutex);
3487 	return seq_list_start_head(&proto_list, *pos);
3488 }
3489 
3490 static void *proto_seq_next(struct seq_file *seq, void *v, loff_t *pos)
3491 {
3492 	return seq_list_next(v, &proto_list, pos);
3493 }
3494 
3495 static void proto_seq_stop(struct seq_file *seq, void *v)
3496 	__releases(proto_list_mutex)
3497 {
3498 	mutex_unlock(&proto_list_mutex);
3499 }
3500 
3501 static char proto_method_implemented(const void *method)
3502 {
3503 	return method == NULL ? 'n' : 'y';
3504 }
3505 static long sock_prot_memory_allocated(struct proto *proto)
3506 {
3507 	return proto->memory_allocated != NULL ? proto_memory_allocated(proto) : -1L;
3508 }
3509 
3510 static const char *sock_prot_memory_pressure(struct proto *proto)
3511 {
3512 	return proto->memory_pressure != NULL ?
3513 	proto_memory_pressure(proto) ? "yes" : "no" : "NI";
3514 }
3515 
3516 static void proto_seq_printf(struct seq_file *seq, struct proto *proto)
3517 {
3518 
3519 	seq_printf(seq, "%-9s %4u %6d  %6ld   %-3s %6u   %-3s  %-10s "
3520 			"%2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c\n",
3521 		   proto->name,
3522 		   proto->obj_size,
3523 		   sock_prot_inuse_get(seq_file_net(seq), proto),
3524 		   sock_prot_memory_allocated(proto),
3525 		   sock_prot_memory_pressure(proto),
3526 		   proto->max_header,
3527 		   proto->slab == NULL ? "no" : "yes",
3528 		   module_name(proto->owner),
3529 		   proto_method_implemented(proto->close),
3530 		   proto_method_implemented(proto->connect),
3531 		   proto_method_implemented(proto->disconnect),
3532 		   proto_method_implemented(proto->accept),
3533 		   proto_method_implemented(proto->ioctl),
3534 		   proto_method_implemented(proto->init),
3535 		   proto_method_implemented(proto->destroy),
3536 		   proto_method_implemented(proto->shutdown),
3537 		   proto_method_implemented(proto->setsockopt),
3538 		   proto_method_implemented(proto->getsockopt),
3539 		   proto_method_implemented(proto->sendmsg),
3540 		   proto_method_implemented(proto->recvmsg),
3541 		   proto_method_implemented(proto->sendpage),
3542 		   proto_method_implemented(proto->bind),
3543 		   proto_method_implemented(proto->backlog_rcv),
3544 		   proto_method_implemented(proto->hash),
3545 		   proto_method_implemented(proto->unhash),
3546 		   proto_method_implemented(proto->get_port),
3547 		   proto_method_implemented(proto->enter_memory_pressure));
3548 }
3549 
3550 static int proto_seq_show(struct seq_file *seq, void *v)
3551 {
3552 	if (v == &proto_list)
3553 		seq_printf(seq, "%-9s %-4s %-8s %-6s %-5s %-7s %-4s %-10s %s",
3554 			   "protocol",
3555 			   "size",
3556 			   "sockets",
3557 			   "memory",
3558 			   "press",
3559 			   "maxhdr",
3560 			   "slab",
3561 			   "module",
3562 			   "cl co di ac io in de sh ss gs se re sp bi br ha uh gp em\n");
3563 	else
3564 		proto_seq_printf(seq, list_entry(v, struct proto, node));
3565 	return 0;
3566 }
3567 
3568 static const struct seq_operations proto_seq_ops = {
3569 	.start  = proto_seq_start,
3570 	.next   = proto_seq_next,
3571 	.stop   = proto_seq_stop,
3572 	.show   = proto_seq_show,
3573 };
3574 
3575 static __net_init int proto_init_net(struct net *net)
3576 {
3577 	if (!proc_create_net("protocols", 0444, net->proc_net, &proto_seq_ops,
3578 			sizeof(struct seq_net_private)))
3579 		return -ENOMEM;
3580 
3581 	return 0;
3582 }
3583 
3584 static __net_exit void proto_exit_net(struct net *net)
3585 {
3586 	remove_proc_entry("protocols", net->proc_net);
3587 }
3588 
3589 
3590 static __net_initdata struct pernet_operations proto_net_ops = {
3591 	.init = proto_init_net,
3592 	.exit = proto_exit_net,
3593 };
3594 
3595 static int __init proto_init(void)
3596 {
3597 	return register_pernet_subsys(&proto_net_ops);
3598 }
3599 
3600 subsys_initcall(proto_init);
3601 
3602 #endif /* PROC_FS */
3603 
3604 #ifdef CONFIG_NET_RX_BUSY_POLL
3605 bool sk_busy_loop_end(void *p, unsigned long start_time)
3606 {
3607 	struct sock *sk = p;
3608 
3609 	return !skb_queue_empty_lockless(&sk->sk_receive_queue) ||
3610 	       sk_busy_loop_timeout(sk, start_time);
3611 }
3612 EXPORT_SYMBOL(sk_busy_loop_end);
3613 #endif /* CONFIG_NET_RX_BUSY_POLL */
3614