xref: /openbmc/linux/net/core/sock.c (revision 76a9ebe811fb3d0605cb084f1ae6be5610541865)
1 /*
2  * INET		An implementation of the TCP/IP protocol suite for the LINUX
3  *		operating system.  INET is implemented using the  BSD Socket
4  *		interface as the means of communication with the user level.
5  *
6  *		Generic socket support routines. Memory allocators, socket lock/release
7  *		handler for protocols to use and generic option handler.
8  *
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  *		This program is free software; you can redistribute it and/or
87  *		modify it under the terms of the GNU General Public License
88  *		as published by the Free Software Foundation; either version
89  *		2 of the License, or (at your option) any later version.
90  */
91 
92 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
93 
94 #include <asm/unaligned.h>
95 #include <linux/capability.h>
96 #include <linux/errno.h>
97 #include <linux/errqueue.h>
98 #include <linux/types.h>
99 #include <linux/socket.h>
100 #include <linux/in.h>
101 #include <linux/kernel.h>
102 #include <linux/module.h>
103 #include <linux/proc_fs.h>
104 #include <linux/seq_file.h>
105 #include <linux/sched.h>
106 #include <linux/sched/mm.h>
107 #include <linux/timer.h>
108 #include <linux/string.h>
109 #include <linux/sockios.h>
110 #include <linux/net.h>
111 #include <linux/mm.h>
112 #include <linux/slab.h>
113 #include <linux/interrupt.h>
114 #include <linux/poll.h>
115 #include <linux/tcp.h>
116 #include <linux/init.h>
117 #include <linux/highmem.h>
118 #include <linux/user_namespace.h>
119 #include <linux/static_key.h>
120 #include <linux/memcontrol.h>
121 #include <linux/prefetch.h>
122 
123 #include <linux/uaccess.h>
124 
125 #include <linux/netdevice.h>
126 #include <net/protocol.h>
127 #include <linux/skbuff.h>
128 #include <net/net_namespace.h>
129 #include <net/request_sock.h>
130 #include <net/sock.h>
131 #include <linux/net_tstamp.h>
132 #include <net/xfrm.h>
133 #include <linux/ipsec.h>
134 #include <net/cls_cgroup.h>
135 #include <net/netprio_cgroup.h>
136 #include <linux/sock_diag.h>
137 
138 #include <linux/filter.h>
139 #include <net/sock_reuseport.h>
140 
141 #include <trace/events/sock.h>
142 
143 #include <net/tcp.h>
144 #include <net/busy_poll.h>
145 
146 static DEFINE_MUTEX(proto_list_mutex);
147 static LIST_HEAD(proto_list);
148 
149 static void sock_inuse_add(struct net *net, int val);
150 
151 /**
152  * sk_ns_capable - General socket capability test
153  * @sk: Socket to use a capability on or through
154  * @user_ns: The user namespace of the capability to use
155  * @cap: The capability to use
156  *
157  * Test to see if the opener of the socket had when the socket was
158  * created and the current process has the capability @cap in the user
159  * namespace @user_ns.
160  */
161 bool sk_ns_capable(const struct sock *sk,
162 		   struct user_namespace *user_ns, int cap)
163 {
164 	return file_ns_capable(sk->sk_socket->file, user_ns, cap) &&
165 		ns_capable(user_ns, cap);
166 }
167 EXPORT_SYMBOL(sk_ns_capable);
168 
169 /**
170  * sk_capable - Socket global capability test
171  * @sk: Socket to use a capability on or through
172  * @cap: The global capability to use
173  *
174  * Test to see if the opener of the socket had when the socket was
175  * created and the current process has the capability @cap in all user
176  * namespaces.
177  */
178 bool sk_capable(const struct sock *sk, int cap)
179 {
180 	return sk_ns_capable(sk, &init_user_ns, cap);
181 }
182 EXPORT_SYMBOL(sk_capable);
183 
184 /**
185  * sk_net_capable - Network namespace socket capability test
186  * @sk: Socket to use a capability on or through
187  * @cap: The capability to use
188  *
189  * Test to see if the opener of the socket had when the socket was created
190  * and the current process has the capability @cap over the network namespace
191  * the socket is a member of.
192  */
193 bool sk_net_capable(const struct sock *sk, int cap)
194 {
195 	return sk_ns_capable(sk, sock_net(sk)->user_ns, cap);
196 }
197 EXPORT_SYMBOL(sk_net_capable);
198 
199 /*
200  * Each address family might have different locking rules, so we have
201  * one slock key per address family and separate keys for internal and
202  * userspace sockets.
203  */
204 static struct lock_class_key af_family_keys[AF_MAX];
205 static struct lock_class_key af_family_kern_keys[AF_MAX];
206 static struct lock_class_key af_family_slock_keys[AF_MAX];
207 static struct lock_class_key af_family_kern_slock_keys[AF_MAX];
208 
209 /*
210  * Make lock validator output more readable. (we pre-construct these
211  * strings build-time, so that runtime initialization of socket
212  * locks is fast):
213  */
214 
215 #define _sock_locks(x)						  \
216   x "AF_UNSPEC",	x "AF_UNIX"     ,	x "AF_INET"     , \
217   x "AF_AX25"  ,	x "AF_IPX"      ,	x "AF_APPLETALK", \
218   x "AF_NETROM",	x "AF_BRIDGE"   ,	x "AF_ATMPVC"   , \
219   x "AF_X25"   ,	x "AF_INET6"    ,	x "AF_ROSE"     , \
220   x "AF_DECnet",	x "AF_NETBEUI"  ,	x "AF_SECURITY" , \
221   x "AF_KEY"   ,	x "AF_NETLINK"  ,	x "AF_PACKET"   , \
222   x "AF_ASH"   ,	x "AF_ECONET"   ,	x "AF_ATMSVC"   , \
223   x "AF_RDS"   ,	x "AF_SNA"      ,	x "AF_IRDA"     , \
224   x "AF_PPPOX" ,	x "AF_WANPIPE"  ,	x "AF_LLC"      , \
225   x "27"       ,	x "28"          ,	x "AF_CAN"      , \
226   x "AF_TIPC"  ,	x "AF_BLUETOOTH",	x "IUCV"        , \
227   x "AF_RXRPC" ,	x "AF_ISDN"     ,	x "AF_PHONET"   , \
228   x "AF_IEEE802154",	x "AF_CAIF"	,	x "AF_ALG"      , \
229   x "AF_NFC"   ,	x "AF_VSOCK"    ,	x "AF_KCM"      , \
230   x "AF_QIPCRTR",	x "AF_SMC"	,	x "AF_XDP"	, \
231   x "AF_MAX"
232 
233 static const char *const af_family_key_strings[AF_MAX+1] = {
234 	_sock_locks("sk_lock-")
235 };
236 static const char *const af_family_slock_key_strings[AF_MAX+1] = {
237 	_sock_locks("slock-")
238 };
239 static const char *const af_family_clock_key_strings[AF_MAX+1] = {
240 	_sock_locks("clock-")
241 };
242 
243 static const char *const af_family_kern_key_strings[AF_MAX+1] = {
244 	_sock_locks("k-sk_lock-")
245 };
246 static const char *const af_family_kern_slock_key_strings[AF_MAX+1] = {
247 	_sock_locks("k-slock-")
248 };
249 static const char *const af_family_kern_clock_key_strings[AF_MAX+1] = {
250 	_sock_locks("k-clock-")
251 };
252 static const char *const af_family_rlock_key_strings[AF_MAX+1] = {
253 	_sock_locks("rlock-")
254 };
255 static const char *const af_family_wlock_key_strings[AF_MAX+1] = {
256 	_sock_locks("wlock-")
257 };
258 static const char *const af_family_elock_key_strings[AF_MAX+1] = {
259 	_sock_locks("elock-")
260 };
261 
262 /*
263  * sk_callback_lock and sk queues locking rules are per-address-family,
264  * so split the lock classes by using a per-AF key:
265  */
266 static struct lock_class_key af_callback_keys[AF_MAX];
267 static struct lock_class_key af_rlock_keys[AF_MAX];
268 static struct lock_class_key af_wlock_keys[AF_MAX];
269 static struct lock_class_key af_elock_keys[AF_MAX];
270 static struct lock_class_key af_kern_callback_keys[AF_MAX];
271 
272 /* Run time adjustable parameters. */
273 __u32 sysctl_wmem_max __read_mostly = SK_WMEM_MAX;
274 EXPORT_SYMBOL(sysctl_wmem_max);
275 __u32 sysctl_rmem_max __read_mostly = SK_RMEM_MAX;
276 EXPORT_SYMBOL(sysctl_rmem_max);
277 __u32 sysctl_wmem_default __read_mostly = SK_WMEM_MAX;
278 __u32 sysctl_rmem_default __read_mostly = SK_RMEM_MAX;
279 
280 /* Maximal space eaten by iovec or ancillary data plus some space */
281 int sysctl_optmem_max __read_mostly = sizeof(unsigned long)*(2*UIO_MAXIOV+512);
282 EXPORT_SYMBOL(sysctl_optmem_max);
283 
284 int sysctl_tstamp_allow_data __read_mostly = 1;
285 
286 DEFINE_STATIC_KEY_FALSE(memalloc_socks_key);
287 EXPORT_SYMBOL_GPL(memalloc_socks_key);
288 
289 /**
290  * sk_set_memalloc - sets %SOCK_MEMALLOC
291  * @sk: socket to set it on
292  *
293  * Set %SOCK_MEMALLOC on a socket for access to emergency reserves.
294  * It's the responsibility of the admin to adjust min_free_kbytes
295  * to meet the requirements
296  */
297 void sk_set_memalloc(struct sock *sk)
298 {
299 	sock_set_flag(sk, SOCK_MEMALLOC);
300 	sk->sk_allocation |= __GFP_MEMALLOC;
301 	static_branch_inc(&memalloc_socks_key);
302 }
303 EXPORT_SYMBOL_GPL(sk_set_memalloc);
304 
305 void sk_clear_memalloc(struct sock *sk)
306 {
307 	sock_reset_flag(sk, SOCK_MEMALLOC);
308 	sk->sk_allocation &= ~__GFP_MEMALLOC;
309 	static_branch_dec(&memalloc_socks_key);
310 
311 	/*
312 	 * SOCK_MEMALLOC is allowed to ignore rmem limits to ensure forward
313 	 * progress of swapping. SOCK_MEMALLOC may be cleared while
314 	 * it has rmem allocations due to the last swapfile being deactivated
315 	 * but there is a risk that the socket is unusable due to exceeding
316 	 * the rmem limits. Reclaim the reserves and obey rmem limits again.
317 	 */
318 	sk_mem_reclaim(sk);
319 }
320 EXPORT_SYMBOL_GPL(sk_clear_memalloc);
321 
322 int __sk_backlog_rcv(struct sock *sk, struct sk_buff *skb)
323 {
324 	int ret;
325 	unsigned int noreclaim_flag;
326 
327 	/* these should have been dropped before queueing */
328 	BUG_ON(!sock_flag(sk, SOCK_MEMALLOC));
329 
330 	noreclaim_flag = memalloc_noreclaim_save();
331 	ret = sk->sk_backlog_rcv(sk, skb);
332 	memalloc_noreclaim_restore(noreclaim_flag);
333 
334 	return ret;
335 }
336 EXPORT_SYMBOL(__sk_backlog_rcv);
337 
338 static int sock_set_timeout(long *timeo_p, char __user *optval, int optlen)
339 {
340 	struct timeval tv;
341 
342 	if (optlen < sizeof(tv))
343 		return -EINVAL;
344 	if (copy_from_user(&tv, optval, sizeof(tv)))
345 		return -EFAULT;
346 	if (tv.tv_usec < 0 || tv.tv_usec >= USEC_PER_SEC)
347 		return -EDOM;
348 
349 	if (tv.tv_sec < 0) {
350 		static int warned __read_mostly;
351 
352 		*timeo_p = 0;
353 		if (warned < 10 && net_ratelimit()) {
354 			warned++;
355 			pr_info("%s: `%s' (pid %d) tries to set negative timeout\n",
356 				__func__, current->comm, task_pid_nr(current));
357 		}
358 		return 0;
359 	}
360 	*timeo_p = MAX_SCHEDULE_TIMEOUT;
361 	if (tv.tv_sec == 0 && tv.tv_usec == 0)
362 		return 0;
363 	if (tv.tv_sec < (MAX_SCHEDULE_TIMEOUT/HZ - 1))
364 		*timeo_p = tv.tv_sec * HZ + DIV_ROUND_UP(tv.tv_usec, USEC_PER_SEC / HZ);
365 	return 0;
366 }
367 
368 static void sock_warn_obsolete_bsdism(const char *name)
369 {
370 	static int warned;
371 	static char warncomm[TASK_COMM_LEN];
372 	if (strcmp(warncomm, current->comm) && warned < 5) {
373 		strcpy(warncomm,  current->comm);
374 		pr_warn("process `%s' is using obsolete %s SO_BSDCOMPAT\n",
375 			warncomm, name);
376 		warned++;
377 	}
378 }
379 
380 static bool sock_needs_netstamp(const struct sock *sk)
381 {
382 	switch (sk->sk_family) {
383 	case AF_UNSPEC:
384 	case AF_UNIX:
385 		return false;
386 	default:
387 		return true;
388 	}
389 }
390 
391 static void sock_disable_timestamp(struct sock *sk, unsigned long flags)
392 {
393 	if (sk->sk_flags & flags) {
394 		sk->sk_flags &= ~flags;
395 		if (sock_needs_netstamp(sk) &&
396 		    !(sk->sk_flags & SK_FLAGS_TIMESTAMP))
397 			net_disable_timestamp();
398 	}
399 }
400 
401 
402 int __sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
403 {
404 	unsigned long flags;
405 	struct sk_buff_head *list = &sk->sk_receive_queue;
406 
407 	if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf) {
408 		atomic_inc(&sk->sk_drops);
409 		trace_sock_rcvqueue_full(sk, skb);
410 		return -ENOMEM;
411 	}
412 
413 	if (!sk_rmem_schedule(sk, skb, skb->truesize)) {
414 		atomic_inc(&sk->sk_drops);
415 		return -ENOBUFS;
416 	}
417 
418 	skb->dev = NULL;
419 	skb_set_owner_r(skb, sk);
420 
421 	/* we escape from rcu protected region, make sure we dont leak
422 	 * a norefcounted dst
423 	 */
424 	skb_dst_force(skb);
425 
426 	spin_lock_irqsave(&list->lock, flags);
427 	sock_skb_set_dropcount(sk, skb);
428 	__skb_queue_tail(list, skb);
429 	spin_unlock_irqrestore(&list->lock, flags);
430 
431 	if (!sock_flag(sk, SOCK_DEAD))
432 		sk->sk_data_ready(sk);
433 	return 0;
434 }
435 EXPORT_SYMBOL(__sock_queue_rcv_skb);
436 
437 int sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
438 {
439 	int err;
440 
441 	err = sk_filter(sk, skb);
442 	if (err)
443 		return err;
444 
445 	return __sock_queue_rcv_skb(sk, skb);
446 }
447 EXPORT_SYMBOL(sock_queue_rcv_skb);
448 
449 int __sk_receive_skb(struct sock *sk, struct sk_buff *skb,
450 		     const int nested, unsigned int trim_cap, bool refcounted)
451 {
452 	int rc = NET_RX_SUCCESS;
453 
454 	if (sk_filter_trim_cap(sk, skb, trim_cap))
455 		goto discard_and_relse;
456 
457 	skb->dev = NULL;
458 
459 	if (sk_rcvqueues_full(sk, sk->sk_rcvbuf)) {
460 		atomic_inc(&sk->sk_drops);
461 		goto discard_and_relse;
462 	}
463 	if (nested)
464 		bh_lock_sock_nested(sk);
465 	else
466 		bh_lock_sock(sk);
467 	if (!sock_owned_by_user(sk)) {
468 		/*
469 		 * trylock + unlock semantics:
470 		 */
471 		mutex_acquire(&sk->sk_lock.dep_map, 0, 1, _RET_IP_);
472 
473 		rc = sk_backlog_rcv(sk, skb);
474 
475 		mutex_release(&sk->sk_lock.dep_map, 1, _RET_IP_);
476 	} else if (sk_add_backlog(sk, skb, sk->sk_rcvbuf)) {
477 		bh_unlock_sock(sk);
478 		atomic_inc(&sk->sk_drops);
479 		goto discard_and_relse;
480 	}
481 
482 	bh_unlock_sock(sk);
483 out:
484 	if (refcounted)
485 		sock_put(sk);
486 	return rc;
487 discard_and_relse:
488 	kfree_skb(skb);
489 	goto out;
490 }
491 EXPORT_SYMBOL(__sk_receive_skb);
492 
493 struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie)
494 {
495 	struct dst_entry *dst = __sk_dst_get(sk);
496 
497 	if (dst && dst->obsolete && dst->ops->check(dst, cookie) == NULL) {
498 		sk_tx_queue_clear(sk);
499 		sk->sk_dst_pending_confirm = 0;
500 		RCU_INIT_POINTER(sk->sk_dst_cache, NULL);
501 		dst_release(dst);
502 		return NULL;
503 	}
504 
505 	return dst;
506 }
507 EXPORT_SYMBOL(__sk_dst_check);
508 
509 struct dst_entry *sk_dst_check(struct sock *sk, u32 cookie)
510 {
511 	struct dst_entry *dst = sk_dst_get(sk);
512 
513 	if (dst && dst->obsolete && dst->ops->check(dst, cookie) == NULL) {
514 		sk_dst_reset(sk);
515 		dst_release(dst);
516 		return NULL;
517 	}
518 
519 	return dst;
520 }
521 EXPORT_SYMBOL(sk_dst_check);
522 
523 static int sock_setbindtodevice(struct sock *sk, char __user *optval,
524 				int optlen)
525 {
526 	int ret = -ENOPROTOOPT;
527 #ifdef CONFIG_NETDEVICES
528 	struct net *net = sock_net(sk);
529 	char devname[IFNAMSIZ];
530 	int index;
531 
532 	/* Sorry... */
533 	ret = -EPERM;
534 	if (!ns_capable(net->user_ns, CAP_NET_RAW))
535 		goto out;
536 
537 	ret = -EINVAL;
538 	if (optlen < 0)
539 		goto out;
540 
541 	/* Bind this socket to a particular device like "eth0",
542 	 * as specified in the passed interface name. If the
543 	 * name is "" or the option length is zero the socket
544 	 * is not bound.
545 	 */
546 	if (optlen > IFNAMSIZ - 1)
547 		optlen = IFNAMSIZ - 1;
548 	memset(devname, 0, sizeof(devname));
549 
550 	ret = -EFAULT;
551 	if (copy_from_user(devname, optval, optlen))
552 		goto out;
553 
554 	index = 0;
555 	if (devname[0] != '\0') {
556 		struct net_device *dev;
557 
558 		rcu_read_lock();
559 		dev = dev_get_by_name_rcu(net, devname);
560 		if (dev)
561 			index = dev->ifindex;
562 		rcu_read_unlock();
563 		ret = -ENODEV;
564 		if (!dev)
565 			goto out;
566 	}
567 
568 	lock_sock(sk);
569 	sk->sk_bound_dev_if = index;
570 	sk_dst_reset(sk);
571 	release_sock(sk);
572 
573 	ret = 0;
574 
575 out:
576 #endif
577 
578 	return ret;
579 }
580 
581 static int sock_getbindtodevice(struct sock *sk, char __user *optval,
582 				int __user *optlen, int len)
583 {
584 	int ret = -ENOPROTOOPT;
585 #ifdef CONFIG_NETDEVICES
586 	struct net *net = sock_net(sk);
587 	char devname[IFNAMSIZ];
588 
589 	if (sk->sk_bound_dev_if == 0) {
590 		len = 0;
591 		goto zero;
592 	}
593 
594 	ret = -EINVAL;
595 	if (len < IFNAMSIZ)
596 		goto out;
597 
598 	ret = netdev_get_name(net, devname, sk->sk_bound_dev_if);
599 	if (ret)
600 		goto out;
601 
602 	len = strlen(devname) + 1;
603 
604 	ret = -EFAULT;
605 	if (copy_to_user(optval, devname, len))
606 		goto out;
607 
608 zero:
609 	ret = -EFAULT;
610 	if (put_user(len, optlen))
611 		goto out;
612 
613 	ret = 0;
614 
615 out:
616 #endif
617 
618 	return ret;
619 }
620 
621 static inline void sock_valbool_flag(struct sock *sk, int bit, int valbool)
622 {
623 	if (valbool)
624 		sock_set_flag(sk, bit);
625 	else
626 		sock_reset_flag(sk, bit);
627 }
628 
629 bool sk_mc_loop(struct sock *sk)
630 {
631 	if (dev_recursion_level())
632 		return false;
633 	if (!sk)
634 		return true;
635 	switch (sk->sk_family) {
636 	case AF_INET:
637 		return inet_sk(sk)->mc_loop;
638 #if IS_ENABLED(CONFIG_IPV6)
639 	case AF_INET6:
640 		return inet6_sk(sk)->mc_loop;
641 #endif
642 	}
643 	WARN_ON(1);
644 	return true;
645 }
646 EXPORT_SYMBOL(sk_mc_loop);
647 
648 /*
649  *	This is meant for all protocols to use and covers goings on
650  *	at the socket level. Everything here is generic.
651  */
652 
653 int sock_setsockopt(struct socket *sock, int level, int optname,
654 		    char __user *optval, unsigned int optlen)
655 {
656 	struct sock_txtime sk_txtime;
657 	struct sock *sk = sock->sk;
658 	int val;
659 	int valbool;
660 	struct linger ling;
661 	int ret = 0;
662 
663 	/*
664 	 *	Options without arguments
665 	 */
666 
667 	if (optname == SO_BINDTODEVICE)
668 		return sock_setbindtodevice(sk, optval, optlen);
669 
670 	if (optlen < sizeof(int))
671 		return -EINVAL;
672 
673 	if (get_user(val, (int __user *)optval))
674 		return -EFAULT;
675 
676 	valbool = val ? 1 : 0;
677 
678 	lock_sock(sk);
679 
680 	switch (optname) {
681 	case SO_DEBUG:
682 		if (val && !capable(CAP_NET_ADMIN))
683 			ret = -EACCES;
684 		else
685 			sock_valbool_flag(sk, SOCK_DBG, valbool);
686 		break;
687 	case SO_REUSEADDR:
688 		sk->sk_reuse = (valbool ? SK_CAN_REUSE : SK_NO_REUSE);
689 		break;
690 	case SO_REUSEPORT:
691 		sk->sk_reuseport = valbool;
692 		break;
693 	case SO_TYPE:
694 	case SO_PROTOCOL:
695 	case SO_DOMAIN:
696 	case SO_ERROR:
697 		ret = -ENOPROTOOPT;
698 		break;
699 	case SO_DONTROUTE:
700 		sock_valbool_flag(sk, SOCK_LOCALROUTE, valbool);
701 		break;
702 	case SO_BROADCAST:
703 		sock_valbool_flag(sk, SOCK_BROADCAST, valbool);
704 		break;
705 	case SO_SNDBUF:
706 		/* Don't error on this BSD doesn't and if you think
707 		 * about it this is right. Otherwise apps have to
708 		 * play 'guess the biggest size' games. RCVBUF/SNDBUF
709 		 * are treated in BSD as hints
710 		 */
711 		val = min_t(u32, val, sysctl_wmem_max);
712 set_sndbuf:
713 		sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
714 		sk->sk_sndbuf = max_t(int, val * 2, SOCK_MIN_SNDBUF);
715 		/* Wake up sending tasks if we upped the value. */
716 		sk->sk_write_space(sk);
717 		break;
718 
719 	case SO_SNDBUFFORCE:
720 		if (!capable(CAP_NET_ADMIN)) {
721 			ret = -EPERM;
722 			break;
723 		}
724 		goto set_sndbuf;
725 
726 	case SO_RCVBUF:
727 		/* Don't error on this BSD doesn't and if you think
728 		 * about it this is right. Otherwise apps have to
729 		 * play 'guess the biggest size' games. RCVBUF/SNDBUF
730 		 * are treated in BSD as hints
731 		 */
732 		val = min_t(u32, val, sysctl_rmem_max);
733 set_rcvbuf:
734 		sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
735 		/*
736 		 * We double it on the way in to account for
737 		 * "struct sk_buff" etc. overhead.   Applications
738 		 * assume that the SO_RCVBUF setting they make will
739 		 * allow that much actual data to be received on that
740 		 * socket.
741 		 *
742 		 * Applications are unaware that "struct sk_buff" and
743 		 * other overheads allocate from the receive buffer
744 		 * during socket buffer allocation.
745 		 *
746 		 * And after considering the possible alternatives,
747 		 * returning the value we actually used in getsockopt
748 		 * is the most desirable behavior.
749 		 */
750 		sk->sk_rcvbuf = max_t(int, val * 2, SOCK_MIN_RCVBUF);
751 		break;
752 
753 	case SO_RCVBUFFORCE:
754 		if (!capable(CAP_NET_ADMIN)) {
755 			ret = -EPERM;
756 			break;
757 		}
758 		goto set_rcvbuf;
759 
760 	case SO_KEEPALIVE:
761 		if (sk->sk_prot->keepalive)
762 			sk->sk_prot->keepalive(sk, valbool);
763 		sock_valbool_flag(sk, SOCK_KEEPOPEN, valbool);
764 		break;
765 
766 	case SO_OOBINLINE:
767 		sock_valbool_flag(sk, SOCK_URGINLINE, valbool);
768 		break;
769 
770 	case SO_NO_CHECK:
771 		sk->sk_no_check_tx = valbool;
772 		break;
773 
774 	case SO_PRIORITY:
775 		if ((val >= 0 && val <= 6) ||
776 		    ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
777 			sk->sk_priority = val;
778 		else
779 			ret = -EPERM;
780 		break;
781 
782 	case SO_LINGER:
783 		if (optlen < sizeof(ling)) {
784 			ret = -EINVAL;	/* 1003.1g */
785 			break;
786 		}
787 		if (copy_from_user(&ling, optval, sizeof(ling))) {
788 			ret = -EFAULT;
789 			break;
790 		}
791 		if (!ling.l_onoff)
792 			sock_reset_flag(sk, SOCK_LINGER);
793 		else {
794 #if (BITS_PER_LONG == 32)
795 			if ((unsigned int)ling.l_linger >= MAX_SCHEDULE_TIMEOUT/HZ)
796 				sk->sk_lingertime = MAX_SCHEDULE_TIMEOUT;
797 			else
798 #endif
799 				sk->sk_lingertime = (unsigned int)ling.l_linger * HZ;
800 			sock_set_flag(sk, SOCK_LINGER);
801 		}
802 		break;
803 
804 	case SO_BSDCOMPAT:
805 		sock_warn_obsolete_bsdism("setsockopt");
806 		break;
807 
808 	case SO_PASSCRED:
809 		if (valbool)
810 			set_bit(SOCK_PASSCRED, &sock->flags);
811 		else
812 			clear_bit(SOCK_PASSCRED, &sock->flags);
813 		break;
814 
815 	case SO_TIMESTAMP:
816 	case SO_TIMESTAMPNS:
817 		if (valbool)  {
818 			if (optname == SO_TIMESTAMP)
819 				sock_reset_flag(sk, SOCK_RCVTSTAMPNS);
820 			else
821 				sock_set_flag(sk, SOCK_RCVTSTAMPNS);
822 			sock_set_flag(sk, SOCK_RCVTSTAMP);
823 			sock_enable_timestamp(sk, SOCK_TIMESTAMP);
824 		} else {
825 			sock_reset_flag(sk, SOCK_RCVTSTAMP);
826 			sock_reset_flag(sk, SOCK_RCVTSTAMPNS);
827 		}
828 		break;
829 
830 	case SO_TIMESTAMPING:
831 		if (val & ~SOF_TIMESTAMPING_MASK) {
832 			ret = -EINVAL;
833 			break;
834 		}
835 
836 		if (val & SOF_TIMESTAMPING_OPT_ID &&
837 		    !(sk->sk_tsflags & SOF_TIMESTAMPING_OPT_ID)) {
838 			if (sk->sk_protocol == IPPROTO_TCP &&
839 			    sk->sk_type == SOCK_STREAM) {
840 				if ((1 << sk->sk_state) &
841 				    (TCPF_CLOSE | TCPF_LISTEN)) {
842 					ret = -EINVAL;
843 					break;
844 				}
845 				sk->sk_tskey = tcp_sk(sk)->snd_una;
846 			} else {
847 				sk->sk_tskey = 0;
848 			}
849 		}
850 
851 		if (val & SOF_TIMESTAMPING_OPT_STATS &&
852 		    !(val & SOF_TIMESTAMPING_OPT_TSONLY)) {
853 			ret = -EINVAL;
854 			break;
855 		}
856 
857 		sk->sk_tsflags = val;
858 		if (val & SOF_TIMESTAMPING_RX_SOFTWARE)
859 			sock_enable_timestamp(sk,
860 					      SOCK_TIMESTAMPING_RX_SOFTWARE);
861 		else
862 			sock_disable_timestamp(sk,
863 					       (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE));
864 		break;
865 
866 	case SO_RCVLOWAT:
867 		if (val < 0)
868 			val = INT_MAX;
869 		if (sock->ops->set_rcvlowat)
870 			ret = sock->ops->set_rcvlowat(sk, val);
871 		else
872 			sk->sk_rcvlowat = val ? : 1;
873 		break;
874 
875 	case SO_RCVTIMEO:
876 		ret = sock_set_timeout(&sk->sk_rcvtimeo, optval, optlen);
877 		break;
878 
879 	case SO_SNDTIMEO:
880 		ret = sock_set_timeout(&sk->sk_sndtimeo, optval, optlen);
881 		break;
882 
883 	case SO_ATTACH_FILTER:
884 		ret = -EINVAL;
885 		if (optlen == sizeof(struct sock_fprog)) {
886 			struct sock_fprog fprog;
887 
888 			ret = -EFAULT;
889 			if (copy_from_user(&fprog, optval, sizeof(fprog)))
890 				break;
891 
892 			ret = sk_attach_filter(&fprog, sk);
893 		}
894 		break;
895 
896 	case SO_ATTACH_BPF:
897 		ret = -EINVAL;
898 		if (optlen == sizeof(u32)) {
899 			u32 ufd;
900 
901 			ret = -EFAULT;
902 			if (copy_from_user(&ufd, optval, sizeof(ufd)))
903 				break;
904 
905 			ret = sk_attach_bpf(ufd, sk);
906 		}
907 		break;
908 
909 	case SO_ATTACH_REUSEPORT_CBPF:
910 		ret = -EINVAL;
911 		if (optlen == sizeof(struct sock_fprog)) {
912 			struct sock_fprog fprog;
913 
914 			ret = -EFAULT;
915 			if (copy_from_user(&fprog, optval, sizeof(fprog)))
916 				break;
917 
918 			ret = sk_reuseport_attach_filter(&fprog, sk);
919 		}
920 		break;
921 
922 	case SO_ATTACH_REUSEPORT_EBPF:
923 		ret = -EINVAL;
924 		if (optlen == sizeof(u32)) {
925 			u32 ufd;
926 
927 			ret = -EFAULT;
928 			if (copy_from_user(&ufd, optval, sizeof(ufd)))
929 				break;
930 
931 			ret = sk_reuseport_attach_bpf(ufd, sk);
932 		}
933 		break;
934 
935 	case SO_DETACH_FILTER:
936 		ret = sk_detach_filter(sk);
937 		break;
938 
939 	case SO_LOCK_FILTER:
940 		if (sock_flag(sk, SOCK_FILTER_LOCKED) && !valbool)
941 			ret = -EPERM;
942 		else
943 			sock_valbool_flag(sk, SOCK_FILTER_LOCKED, valbool);
944 		break;
945 
946 	case SO_PASSSEC:
947 		if (valbool)
948 			set_bit(SOCK_PASSSEC, &sock->flags);
949 		else
950 			clear_bit(SOCK_PASSSEC, &sock->flags);
951 		break;
952 	case SO_MARK:
953 		if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
954 			ret = -EPERM;
955 		else
956 			sk->sk_mark = val;
957 		break;
958 
959 	case SO_RXQ_OVFL:
960 		sock_valbool_flag(sk, SOCK_RXQ_OVFL, valbool);
961 		break;
962 
963 	case SO_WIFI_STATUS:
964 		sock_valbool_flag(sk, SOCK_WIFI_STATUS, valbool);
965 		break;
966 
967 	case SO_PEEK_OFF:
968 		if (sock->ops->set_peek_off)
969 			ret = sock->ops->set_peek_off(sk, val);
970 		else
971 			ret = -EOPNOTSUPP;
972 		break;
973 
974 	case SO_NOFCS:
975 		sock_valbool_flag(sk, SOCK_NOFCS, valbool);
976 		break;
977 
978 	case SO_SELECT_ERR_QUEUE:
979 		sock_valbool_flag(sk, SOCK_SELECT_ERR_QUEUE, valbool);
980 		break;
981 
982 #ifdef CONFIG_NET_RX_BUSY_POLL
983 	case SO_BUSY_POLL:
984 		/* allow unprivileged users to decrease the value */
985 		if ((val > sk->sk_ll_usec) && !capable(CAP_NET_ADMIN))
986 			ret = -EPERM;
987 		else {
988 			if (val < 0)
989 				ret = -EINVAL;
990 			else
991 				sk->sk_ll_usec = val;
992 		}
993 		break;
994 #endif
995 
996 	case SO_MAX_PACING_RATE:
997 		if (val != ~0U)
998 			cmpxchg(&sk->sk_pacing_status,
999 				SK_PACING_NONE,
1000 				SK_PACING_NEEDED);
1001 		sk->sk_max_pacing_rate = (val == ~0U) ? ~0UL : val;
1002 		sk->sk_pacing_rate = min(sk->sk_pacing_rate,
1003 					 sk->sk_max_pacing_rate);
1004 		break;
1005 
1006 	case SO_INCOMING_CPU:
1007 		sk->sk_incoming_cpu = val;
1008 		break;
1009 
1010 	case SO_CNX_ADVICE:
1011 		if (val == 1)
1012 			dst_negative_advice(sk);
1013 		break;
1014 
1015 	case SO_ZEROCOPY:
1016 		if (sk->sk_family == PF_INET || sk->sk_family == PF_INET6) {
1017 			if (sk->sk_protocol != IPPROTO_TCP)
1018 				ret = -ENOTSUPP;
1019 		} else if (sk->sk_family != PF_RDS) {
1020 			ret = -ENOTSUPP;
1021 		}
1022 		if (!ret) {
1023 			if (val < 0 || val > 1)
1024 				ret = -EINVAL;
1025 			else
1026 				sock_valbool_flag(sk, SOCK_ZEROCOPY, valbool);
1027 		}
1028 		break;
1029 
1030 	case SO_TXTIME:
1031 		if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) {
1032 			ret = -EPERM;
1033 		} else if (optlen != sizeof(struct sock_txtime)) {
1034 			ret = -EINVAL;
1035 		} else if (copy_from_user(&sk_txtime, optval,
1036 			   sizeof(struct sock_txtime))) {
1037 			ret = -EFAULT;
1038 		} else if (sk_txtime.flags & ~SOF_TXTIME_FLAGS_MASK) {
1039 			ret = -EINVAL;
1040 		} else {
1041 			sock_valbool_flag(sk, SOCK_TXTIME, true);
1042 			sk->sk_clockid = sk_txtime.clockid;
1043 			sk->sk_txtime_deadline_mode =
1044 				!!(sk_txtime.flags & SOF_TXTIME_DEADLINE_MODE);
1045 			sk->sk_txtime_report_errors =
1046 				!!(sk_txtime.flags & SOF_TXTIME_REPORT_ERRORS);
1047 		}
1048 		break;
1049 
1050 	default:
1051 		ret = -ENOPROTOOPT;
1052 		break;
1053 	}
1054 	release_sock(sk);
1055 	return ret;
1056 }
1057 EXPORT_SYMBOL(sock_setsockopt);
1058 
1059 
1060 static void cred_to_ucred(struct pid *pid, const struct cred *cred,
1061 			  struct ucred *ucred)
1062 {
1063 	ucred->pid = pid_vnr(pid);
1064 	ucred->uid = ucred->gid = -1;
1065 	if (cred) {
1066 		struct user_namespace *current_ns = current_user_ns();
1067 
1068 		ucred->uid = from_kuid_munged(current_ns, cred->euid);
1069 		ucred->gid = from_kgid_munged(current_ns, cred->egid);
1070 	}
1071 }
1072 
1073 static int groups_to_user(gid_t __user *dst, const struct group_info *src)
1074 {
1075 	struct user_namespace *user_ns = current_user_ns();
1076 	int i;
1077 
1078 	for (i = 0; i < src->ngroups; i++)
1079 		if (put_user(from_kgid_munged(user_ns, src->gid[i]), dst + i))
1080 			return -EFAULT;
1081 
1082 	return 0;
1083 }
1084 
1085 int sock_getsockopt(struct socket *sock, int level, int optname,
1086 		    char __user *optval, int __user *optlen)
1087 {
1088 	struct sock *sk = sock->sk;
1089 
1090 	union {
1091 		int val;
1092 		u64 val64;
1093 		struct linger ling;
1094 		struct timeval tm;
1095 		struct sock_txtime txtime;
1096 	} v;
1097 
1098 	int lv = sizeof(int);
1099 	int len;
1100 
1101 	if (get_user(len, optlen))
1102 		return -EFAULT;
1103 	if (len < 0)
1104 		return -EINVAL;
1105 
1106 	memset(&v, 0, sizeof(v));
1107 
1108 	switch (optname) {
1109 	case SO_DEBUG:
1110 		v.val = sock_flag(sk, SOCK_DBG);
1111 		break;
1112 
1113 	case SO_DONTROUTE:
1114 		v.val = sock_flag(sk, SOCK_LOCALROUTE);
1115 		break;
1116 
1117 	case SO_BROADCAST:
1118 		v.val = sock_flag(sk, SOCK_BROADCAST);
1119 		break;
1120 
1121 	case SO_SNDBUF:
1122 		v.val = sk->sk_sndbuf;
1123 		break;
1124 
1125 	case SO_RCVBUF:
1126 		v.val = sk->sk_rcvbuf;
1127 		break;
1128 
1129 	case SO_REUSEADDR:
1130 		v.val = sk->sk_reuse;
1131 		break;
1132 
1133 	case SO_REUSEPORT:
1134 		v.val = sk->sk_reuseport;
1135 		break;
1136 
1137 	case SO_KEEPALIVE:
1138 		v.val = sock_flag(sk, SOCK_KEEPOPEN);
1139 		break;
1140 
1141 	case SO_TYPE:
1142 		v.val = sk->sk_type;
1143 		break;
1144 
1145 	case SO_PROTOCOL:
1146 		v.val = sk->sk_protocol;
1147 		break;
1148 
1149 	case SO_DOMAIN:
1150 		v.val = sk->sk_family;
1151 		break;
1152 
1153 	case SO_ERROR:
1154 		v.val = -sock_error(sk);
1155 		if (v.val == 0)
1156 			v.val = xchg(&sk->sk_err_soft, 0);
1157 		break;
1158 
1159 	case SO_OOBINLINE:
1160 		v.val = sock_flag(sk, SOCK_URGINLINE);
1161 		break;
1162 
1163 	case SO_NO_CHECK:
1164 		v.val = sk->sk_no_check_tx;
1165 		break;
1166 
1167 	case SO_PRIORITY:
1168 		v.val = sk->sk_priority;
1169 		break;
1170 
1171 	case SO_LINGER:
1172 		lv		= sizeof(v.ling);
1173 		v.ling.l_onoff	= sock_flag(sk, SOCK_LINGER);
1174 		v.ling.l_linger	= sk->sk_lingertime / HZ;
1175 		break;
1176 
1177 	case SO_BSDCOMPAT:
1178 		sock_warn_obsolete_bsdism("getsockopt");
1179 		break;
1180 
1181 	case SO_TIMESTAMP:
1182 		v.val = sock_flag(sk, SOCK_RCVTSTAMP) &&
1183 				!sock_flag(sk, SOCK_RCVTSTAMPNS);
1184 		break;
1185 
1186 	case SO_TIMESTAMPNS:
1187 		v.val = sock_flag(sk, SOCK_RCVTSTAMPNS);
1188 		break;
1189 
1190 	case SO_TIMESTAMPING:
1191 		v.val = sk->sk_tsflags;
1192 		break;
1193 
1194 	case SO_RCVTIMEO:
1195 		lv = sizeof(struct timeval);
1196 		if (sk->sk_rcvtimeo == MAX_SCHEDULE_TIMEOUT) {
1197 			v.tm.tv_sec = 0;
1198 			v.tm.tv_usec = 0;
1199 		} else {
1200 			v.tm.tv_sec = sk->sk_rcvtimeo / HZ;
1201 			v.tm.tv_usec = ((sk->sk_rcvtimeo % HZ) * USEC_PER_SEC) / HZ;
1202 		}
1203 		break;
1204 
1205 	case SO_SNDTIMEO:
1206 		lv = sizeof(struct timeval);
1207 		if (sk->sk_sndtimeo == MAX_SCHEDULE_TIMEOUT) {
1208 			v.tm.tv_sec = 0;
1209 			v.tm.tv_usec = 0;
1210 		} else {
1211 			v.tm.tv_sec = sk->sk_sndtimeo / HZ;
1212 			v.tm.tv_usec = ((sk->sk_sndtimeo % HZ) * USEC_PER_SEC) / HZ;
1213 		}
1214 		break;
1215 
1216 	case SO_RCVLOWAT:
1217 		v.val = sk->sk_rcvlowat;
1218 		break;
1219 
1220 	case SO_SNDLOWAT:
1221 		v.val = 1;
1222 		break;
1223 
1224 	case SO_PASSCRED:
1225 		v.val = !!test_bit(SOCK_PASSCRED, &sock->flags);
1226 		break;
1227 
1228 	case SO_PEERCRED:
1229 	{
1230 		struct ucred peercred;
1231 		if (len > sizeof(peercred))
1232 			len = sizeof(peercred);
1233 		cred_to_ucred(sk->sk_peer_pid, sk->sk_peer_cred, &peercred);
1234 		if (copy_to_user(optval, &peercred, len))
1235 			return -EFAULT;
1236 		goto lenout;
1237 	}
1238 
1239 	case SO_PEERGROUPS:
1240 	{
1241 		int ret, n;
1242 
1243 		if (!sk->sk_peer_cred)
1244 			return -ENODATA;
1245 
1246 		n = sk->sk_peer_cred->group_info->ngroups;
1247 		if (len < n * sizeof(gid_t)) {
1248 			len = n * sizeof(gid_t);
1249 			return put_user(len, optlen) ? -EFAULT : -ERANGE;
1250 		}
1251 		len = n * sizeof(gid_t);
1252 
1253 		ret = groups_to_user((gid_t __user *)optval,
1254 				     sk->sk_peer_cred->group_info);
1255 		if (ret)
1256 			return ret;
1257 		goto lenout;
1258 	}
1259 
1260 	case SO_PEERNAME:
1261 	{
1262 		char address[128];
1263 
1264 		lv = sock->ops->getname(sock, (struct sockaddr *)address, 2);
1265 		if (lv < 0)
1266 			return -ENOTCONN;
1267 		if (lv < len)
1268 			return -EINVAL;
1269 		if (copy_to_user(optval, address, len))
1270 			return -EFAULT;
1271 		goto lenout;
1272 	}
1273 
1274 	/* Dubious BSD thing... Probably nobody even uses it, but
1275 	 * the UNIX standard wants it for whatever reason... -DaveM
1276 	 */
1277 	case SO_ACCEPTCONN:
1278 		v.val = sk->sk_state == TCP_LISTEN;
1279 		break;
1280 
1281 	case SO_PASSSEC:
1282 		v.val = !!test_bit(SOCK_PASSSEC, &sock->flags);
1283 		break;
1284 
1285 	case SO_PEERSEC:
1286 		return security_socket_getpeersec_stream(sock, optval, optlen, len);
1287 
1288 	case SO_MARK:
1289 		v.val = sk->sk_mark;
1290 		break;
1291 
1292 	case SO_RXQ_OVFL:
1293 		v.val = sock_flag(sk, SOCK_RXQ_OVFL);
1294 		break;
1295 
1296 	case SO_WIFI_STATUS:
1297 		v.val = sock_flag(sk, SOCK_WIFI_STATUS);
1298 		break;
1299 
1300 	case SO_PEEK_OFF:
1301 		if (!sock->ops->set_peek_off)
1302 			return -EOPNOTSUPP;
1303 
1304 		v.val = sk->sk_peek_off;
1305 		break;
1306 	case SO_NOFCS:
1307 		v.val = sock_flag(sk, SOCK_NOFCS);
1308 		break;
1309 
1310 	case SO_BINDTODEVICE:
1311 		return sock_getbindtodevice(sk, optval, optlen, len);
1312 
1313 	case SO_GET_FILTER:
1314 		len = sk_get_filter(sk, (struct sock_filter __user *)optval, len);
1315 		if (len < 0)
1316 			return len;
1317 
1318 		goto lenout;
1319 
1320 	case SO_LOCK_FILTER:
1321 		v.val = sock_flag(sk, SOCK_FILTER_LOCKED);
1322 		break;
1323 
1324 	case SO_BPF_EXTENSIONS:
1325 		v.val = bpf_tell_extensions();
1326 		break;
1327 
1328 	case SO_SELECT_ERR_QUEUE:
1329 		v.val = sock_flag(sk, SOCK_SELECT_ERR_QUEUE);
1330 		break;
1331 
1332 #ifdef CONFIG_NET_RX_BUSY_POLL
1333 	case SO_BUSY_POLL:
1334 		v.val = sk->sk_ll_usec;
1335 		break;
1336 #endif
1337 
1338 	case SO_MAX_PACING_RATE:
1339 		/* 32bit version */
1340 		v.val = min_t(unsigned long, sk->sk_max_pacing_rate, ~0U);
1341 		break;
1342 
1343 	case SO_INCOMING_CPU:
1344 		v.val = sk->sk_incoming_cpu;
1345 		break;
1346 
1347 	case SO_MEMINFO:
1348 	{
1349 		u32 meminfo[SK_MEMINFO_VARS];
1350 
1351 		if (get_user(len, optlen))
1352 			return -EFAULT;
1353 
1354 		sk_get_meminfo(sk, meminfo);
1355 
1356 		len = min_t(unsigned int, len, sizeof(meminfo));
1357 		if (copy_to_user(optval, &meminfo, len))
1358 			return -EFAULT;
1359 
1360 		goto lenout;
1361 	}
1362 
1363 #ifdef CONFIG_NET_RX_BUSY_POLL
1364 	case SO_INCOMING_NAPI_ID:
1365 		v.val = READ_ONCE(sk->sk_napi_id);
1366 
1367 		/* aggregate non-NAPI IDs down to 0 */
1368 		if (v.val < MIN_NAPI_ID)
1369 			v.val = 0;
1370 
1371 		break;
1372 #endif
1373 
1374 	case SO_COOKIE:
1375 		lv = sizeof(u64);
1376 		if (len < lv)
1377 			return -EINVAL;
1378 		v.val64 = sock_gen_cookie(sk);
1379 		break;
1380 
1381 	case SO_ZEROCOPY:
1382 		v.val = sock_flag(sk, SOCK_ZEROCOPY);
1383 		break;
1384 
1385 	case SO_TXTIME:
1386 		lv = sizeof(v.txtime);
1387 		v.txtime.clockid = sk->sk_clockid;
1388 		v.txtime.flags |= sk->sk_txtime_deadline_mode ?
1389 				  SOF_TXTIME_DEADLINE_MODE : 0;
1390 		v.txtime.flags |= sk->sk_txtime_report_errors ?
1391 				  SOF_TXTIME_REPORT_ERRORS : 0;
1392 		break;
1393 
1394 	default:
1395 		/* We implement the SO_SNDLOWAT etc to not be settable
1396 		 * (1003.1g 7).
1397 		 */
1398 		return -ENOPROTOOPT;
1399 	}
1400 
1401 	if (len > lv)
1402 		len = lv;
1403 	if (copy_to_user(optval, &v, len))
1404 		return -EFAULT;
1405 lenout:
1406 	if (put_user(len, optlen))
1407 		return -EFAULT;
1408 	return 0;
1409 }
1410 
1411 /*
1412  * Initialize an sk_lock.
1413  *
1414  * (We also register the sk_lock with the lock validator.)
1415  */
1416 static inline void sock_lock_init(struct sock *sk)
1417 {
1418 	if (sk->sk_kern_sock)
1419 		sock_lock_init_class_and_name(
1420 			sk,
1421 			af_family_kern_slock_key_strings[sk->sk_family],
1422 			af_family_kern_slock_keys + sk->sk_family,
1423 			af_family_kern_key_strings[sk->sk_family],
1424 			af_family_kern_keys + sk->sk_family);
1425 	else
1426 		sock_lock_init_class_and_name(
1427 			sk,
1428 			af_family_slock_key_strings[sk->sk_family],
1429 			af_family_slock_keys + sk->sk_family,
1430 			af_family_key_strings[sk->sk_family],
1431 			af_family_keys + sk->sk_family);
1432 }
1433 
1434 /*
1435  * Copy all fields from osk to nsk but nsk->sk_refcnt must not change yet,
1436  * even temporarly, because of RCU lookups. sk_node should also be left as is.
1437  * We must not copy fields between sk_dontcopy_begin and sk_dontcopy_end
1438  */
1439 static void sock_copy(struct sock *nsk, const struct sock *osk)
1440 {
1441 #ifdef CONFIG_SECURITY_NETWORK
1442 	void *sptr = nsk->sk_security;
1443 #endif
1444 	memcpy(nsk, osk, offsetof(struct sock, sk_dontcopy_begin));
1445 
1446 	memcpy(&nsk->sk_dontcopy_end, &osk->sk_dontcopy_end,
1447 	       osk->sk_prot->obj_size - offsetof(struct sock, sk_dontcopy_end));
1448 
1449 #ifdef CONFIG_SECURITY_NETWORK
1450 	nsk->sk_security = sptr;
1451 	security_sk_clone(osk, nsk);
1452 #endif
1453 }
1454 
1455 static struct sock *sk_prot_alloc(struct proto *prot, gfp_t priority,
1456 		int family)
1457 {
1458 	struct sock *sk;
1459 	struct kmem_cache *slab;
1460 
1461 	slab = prot->slab;
1462 	if (slab != NULL) {
1463 		sk = kmem_cache_alloc(slab, priority & ~__GFP_ZERO);
1464 		if (!sk)
1465 			return sk;
1466 		if (priority & __GFP_ZERO)
1467 			sk_prot_clear_nulls(sk, prot->obj_size);
1468 	} else
1469 		sk = kmalloc(prot->obj_size, priority);
1470 
1471 	if (sk != NULL) {
1472 		if (security_sk_alloc(sk, family, priority))
1473 			goto out_free;
1474 
1475 		if (!try_module_get(prot->owner))
1476 			goto out_free_sec;
1477 		sk_tx_queue_clear(sk);
1478 	}
1479 
1480 	return sk;
1481 
1482 out_free_sec:
1483 	security_sk_free(sk);
1484 out_free:
1485 	if (slab != NULL)
1486 		kmem_cache_free(slab, sk);
1487 	else
1488 		kfree(sk);
1489 	return NULL;
1490 }
1491 
1492 static void sk_prot_free(struct proto *prot, struct sock *sk)
1493 {
1494 	struct kmem_cache *slab;
1495 	struct module *owner;
1496 
1497 	owner = prot->owner;
1498 	slab = prot->slab;
1499 
1500 	cgroup_sk_free(&sk->sk_cgrp_data);
1501 	mem_cgroup_sk_free(sk);
1502 	security_sk_free(sk);
1503 	if (slab != NULL)
1504 		kmem_cache_free(slab, sk);
1505 	else
1506 		kfree(sk);
1507 	module_put(owner);
1508 }
1509 
1510 /**
1511  *	sk_alloc - All socket objects are allocated here
1512  *	@net: the applicable net namespace
1513  *	@family: protocol family
1514  *	@priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
1515  *	@prot: struct proto associated with this new sock instance
1516  *	@kern: is this to be a kernel socket?
1517  */
1518 struct sock *sk_alloc(struct net *net, int family, gfp_t priority,
1519 		      struct proto *prot, int kern)
1520 {
1521 	struct sock *sk;
1522 
1523 	sk = sk_prot_alloc(prot, priority | __GFP_ZERO, family);
1524 	if (sk) {
1525 		sk->sk_family = family;
1526 		/*
1527 		 * See comment in struct sock definition to understand
1528 		 * why we need sk_prot_creator -acme
1529 		 */
1530 		sk->sk_prot = sk->sk_prot_creator = prot;
1531 		sk->sk_kern_sock = kern;
1532 		sock_lock_init(sk);
1533 		sk->sk_net_refcnt = kern ? 0 : 1;
1534 		if (likely(sk->sk_net_refcnt)) {
1535 			get_net(net);
1536 			sock_inuse_add(net, 1);
1537 		}
1538 
1539 		sock_net_set(sk, net);
1540 		refcount_set(&sk->sk_wmem_alloc, 1);
1541 
1542 		mem_cgroup_sk_alloc(sk);
1543 		cgroup_sk_alloc(&sk->sk_cgrp_data);
1544 		sock_update_classid(&sk->sk_cgrp_data);
1545 		sock_update_netprioidx(&sk->sk_cgrp_data);
1546 	}
1547 
1548 	return sk;
1549 }
1550 EXPORT_SYMBOL(sk_alloc);
1551 
1552 /* Sockets having SOCK_RCU_FREE will call this function after one RCU
1553  * grace period. This is the case for UDP sockets and TCP listeners.
1554  */
1555 static void __sk_destruct(struct rcu_head *head)
1556 {
1557 	struct sock *sk = container_of(head, struct sock, sk_rcu);
1558 	struct sk_filter *filter;
1559 
1560 	if (sk->sk_destruct)
1561 		sk->sk_destruct(sk);
1562 
1563 	filter = rcu_dereference_check(sk->sk_filter,
1564 				       refcount_read(&sk->sk_wmem_alloc) == 0);
1565 	if (filter) {
1566 		sk_filter_uncharge(sk, filter);
1567 		RCU_INIT_POINTER(sk->sk_filter, NULL);
1568 	}
1569 	if (rcu_access_pointer(sk->sk_reuseport_cb))
1570 		reuseport_detach_sock(sk);
1571 
1572 	sock_disable_timestamp(sk, SK_FLAGS_TIMESTAMP);
1573 
1574 	if (atomic_read(&sk->sk_omem_alloc))
1575 		pr_debug("%s: optmem leakage (%d bytes) detected\n",
1576 			 __func__, atomic_read(&sk->sk_omem_alloc));
1577 
1578 	if (sk->sk_frag.page) {
1579 		put_page(sk->sk_frag.page);
1580 		sk->sk_frag.page = NULL;
1581 	}
1582 
1583 	if (sk->sk_peer_cred)
1584 		put_cred(sk->sk_peer_cred);
1585 	put_pid(sk->sk_peer_pid);
1586 	if (likely(sk->sk_net_refcnt))
1587 		put_net(sock_net(sk));
1588 	sk_prot_free(sk->sk_prot_creator, sk);
1589 }
1590 
1591 void sk_destruct(struct sock *sk)
1592 {
1593 	if (sock_flag(sk, SOCK_RCU_FREE))
1594 		call_rcu(&sk->sk_rcu, __sk_destruct);
1595 	else
1596 		__sk_destruct(&sk->sk_rcu);
1597 }
1598 
1599 static void __sk_free(struct sock *sk)
1600 {
1601 	if (likely(sk->sk_net_refcnt))
1602 		sock_inuse_add(sock_net(sk), -1);
1603 
1604 	if (unlikely(sk->sk_net_refcnt && sock_diag_has_destroy_listeners(sk)))
1605 		sock_diag_broadcast_destroy(sk);
1606 	else
1607 		sk_destruct(sk);
1608 }
1609 
1610 void sk_free(struct sock *sk)
1611 {
1612 	/*
1613 	 * We subtract one from sk_wmem_alloc and can know if
1614 	 * some packets are still in some tx queue.
1615 	 * If not null, sock_wfree() will call __sk_free(sk) later
1616 	 */
1617 	if (refcount_dec_and_test(&sk->sk_wmem_alloc))
1618 		__sk_free(sk);
1619 }
1620 EXPORT_SYMBOL(sk_free);
1621 
1622 static void sk_init_common(struct sock *sk)
1623 {
1624 	skb_queue_head_init(&sk->sk_receive_queue);
1625 	skb_queue_head_init(&sk->sk_write_queue);
1626 	skb_queue_head_init(&sk->sk_error_queue);
1627 
1628 	rwlock_init(&sk->sk_callback_lock);
1629 	lockdep_set_class_and_name(&sk->sk_receive_queue.lock,
1630 			af_rlock_keys + sk->sk_family,
1631 			af_family_rlock_key_strings[sk->sk_family]);
1632 	lockdep_set_class_and_name(&sk->sk_write_queue.lock,
1633 			af_wlock_keys + sk->sk_family,
1634 			af_family_wlock_key_strings[sk->sk_family]);
1635 	lockdep_set_class_and_name(&sk->sk_error_queue.lock,
1636 			af_elock_keys + sk->sk_family,
1637 			af_family_elock_key_strings[sk->sk_family]);
1638 	lockdep_set_class_and_name(&sk->sk_callback_lock,
1639 			af_callback_keys + sk->sk_family,
1640 			af_family_clock_key_strings[sk->sk_family]);
1641 }
1642 
1643 /**
1644  *	sk_clone_lock - clone a socket, and lock its clone
1645  *	@sk: the socket to clone
1646  *	@priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
1647  *
1648  *	Caller must unlock socket even in error path (bh_unlock_sock(newsk))
1649  */
1650 struct sock *sk_clone_lock(const struct sock *sk, const gfp_t priority)
1651 {
1652 	struct sock *newsk;
1653 	bool is_charged = true;
1654 
1655 	newsk = sk_prot_alloc(sk->sk_prot, priority, sk->sk_family);
1656 	if (newsk != NULL) {
1657 		struct sk_filter *filter;
1658 
1659 		sock_copy(newsk, sk);
1660 
1661 		newsk->sk_prot_creator = sk->sk_prot;
1662 
1663 		/* SANITY */
1664 		if (likely(newsk->sk_net_refcnt))
1665 			get_net(sock_net(newsk));
1666 		sk_node_init(&newsk->sk_node);
1667 		sock_lock_init(newsk);
1668 		bh_lock_sock(newsk);
1669 		newsk->sk_backlog.head	= newsk->sk_backlog.tail = NULL;
1670 		newsk->sk_backlog.len = 0;
1671 
1672 		atomic_set(&newsk->sk_rmem_alloc, 0);
1673 		/*
1674 		 * sk_wmem_alloc set to one (see sk_free() and sock_wfree())
1675 		 */
1676 		refcount_set(&newsk->sk_wmem_alloc, 1);
1677 		atomic_set(&newsk->sk_omem_alloc, 0);
1678 		sk_init_common(newsk);
1679 
1680 		newsk->sk_dst_cache	= NULL;
1681 		newsk->sk_dst_pending_confirm = 0;
1682 		newsk->sk_wmem_queued	= 0;
1683 		newsk->sk_forward_alloc = 0;
1684 		atomic_set(&newsk->sk_drops, 0);
1685 		newsk->sk_send_head	= NULL;
1686 		newsk->sk_userlocks	= sk->sk_userlocks & ~SOCK_BINDPORT_LOCK;
1687 		atomic_set(&newsk->sk_zckey, 0);
1688 
1689 		sock_reset_flag(newsk, SOCK_DONE);
1690 		mem_cgroup_sk_alloc(newsk);
1691 		cgroup_sk_alloc(&newsk->sk_cgrp_data);
1692 
1693 		rcu_read_lock();
1694 		filter = rcu_dereference(sk->sk_filter);
1695 		if (filter != NULL)
1696 			/* though it's an empty new sock, the charging may fail
1697 			 * if sysctl_optmem_max was changed between creation of
1698 			 * original socket and cloning
1699 			 */
1700 			is_charged = sk_filter_charge(newsk, filter);
1701 		RCU_INIT_POINTER(newsk->sk_filter, filter);
1702 		rcu_read_unlock();
1703 
1704 		if (unlikely(!is_charged || xfrm_sk_clone_policy(newsk, sk))) {
1705 			/* We need to make sure that we don't uncharge the new
1706 			 * socket if we couldn't charge it in the first place
1707 			 * as otherwise we uncharge the parent's filter.
1708 			 */
1709 			if (!is_charged)
1710 				RCU_INIT_POINTER(newsk->sk_filter, NULL);
1711 			sk_free_unlock_clone(newsk);
1712 			newsk = NULL;
1713 			goto out;
1714 		}
1715 		RCU_INIT_POINTER(newsk->sk_reuseport_cb, NULL);
1716 
1717 		newsk->sk_err	   = 0;
1718 		newsk->sk_err_soft = 0;
1719 		newsk->sk_priority = 0;
1720 		newsk->sk_incoming_cpu = raw_smp_processor_id();
1721 		atomic64_set(&newsk->sk_cookie, 0);
1722 		if (likely(newsk->sk_net_refcnt))
1723 			sock_inuse_add(sock_net(newsk), 1);
1724 
1725 		/*
1726 		 * Before updating sk_refcnt, we must commit prior changes to memory
1727 		 * (Documentation/RCU/rculist_nulls.txt for details)
1728 		 */
1729 		smp_wmb();
1730 		refcount_set(&newsk->sk_refcnt, 2);
1731 
1732 		/*
1733 		 * Increment the counter in the same struct proto as the master
1734 		 * sock (sk_refcnt_debug_inc uses newsk->sk_prot->socks, that
1735 		 * is the same as sk->sk_prot->socks, as this field was copied
1736 		 * with memcpy).
1737 		 *
1738 		 * This _changes_ the previous behaviour, where
1739 		 * tcp_create_openreq_child always was incrementing the
1740 		 * equivalent to tcp_prot->socks (inet_sock_nr), so this have
1741 		 * to be taken into account in all callers. -acme
1742 		 */
1743 		sk_refcnt_debug_inc(newsk);
1744 		sk_set_socket(newsk, NULL);
1745 		newsk->sk_wq = NULL;
1746 
1747 		if (newsk->sk_prot->sockets_allocated)
1748 			sk_sockets_allocated_inc(newsk);
1749 
1750 		if (sock_needs_netstamp(sk) &&
1751 		    newsk->sk_flags & SK_FLAGS_TIMESTAMP)
1752 			net_enable_timestamp();
1753 	}
1754 out:
1755 	return newsk;
1756 }
1757 EXPORT_SYMBOL_GPL(sk_clone_lock);
1758 
1759 void sk_free_unlock_clone(struct sock *sk)
1760 {
1761 	/* It is still raw copy of parent, so invalidate
1762 	 * destructor and make plain sk_free() */
1763 	sk->sk_destruct = NULL;
1764 	bh_unlock_sock(sk);
1765 	sk_free(sk);
1766 }
1767 EXPORT_SYMBOL_GPL(sk_free_unlock_clone);
1768 
1769 void sk_setup_caps(struct sock *sk, struct dst_entry *dst)
1770 {
1771 	u32 max_segs = 1;
1772 
1773 	sk_dst_set(sk, dst);
1774 	sk->sk_route_caps = dst->dev->features | sk->sk_route_forced_caps;
1775 	if (sk->sk_route_caps & NETIF_F_GSO)
1776 		sk->sk_route_caps |= NETIF_F_GSO_SOFTWARE;
1777 	sk->sk_route_caps &= ~sk->sk_route_nocaps;
1778 	if (sk_can_gso(sk)) {
1779 		if (dst->header_len && !xfrm_dst_offload_ok(dst)) {
1780 			sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
1781 		} else {
1782 			sk->sk_route_caps |= NETIF_F_SG | NETIF_F_HW_CSUM;
1783 			sk->sk_gso_max_size = dst->dev->gso_max_size;
1784 			max_segs = max_t(u32, dst->dev->gso_max_segs, 1);
1785 		}
1786 	}
1787 	sk->sk_gso_max_segs = max_segs;
1788 }
1789 EXPORT_SYMBOL_GPL(sk_setup_caps);
1790 
1791 /*
1792  *	Simple resource managers for sockets.
1793  */
1794 
1795 
1796 /*
1797  * Write buffer destructor automatically called from kfree_skb.
1798  */
1799 void sock_wfree(struct sk_buff *skb)
1800 {
1801 	struct sock *sk = skb->sk;
1802 	unsigned int len = skb->truesize;
1803 
1804 	if (!sock_flag(sk, SOCK_USE_WRITE_QUEUE)) {
1805 		/*
1806 		 * Keep a reference on sk_wmem_alloc, this will be released
1807 		 * after sk_write_space() call
1808 		 */
1809 		WARN_ON(refcount_sub_and_test(len - 1, &sk->sk_wmem_alloc));
1810 		sk->sk_write_space(sk);
1811 		len = 1;
1812 	}
1813 	/*
1814 	 * if sk_wmem_alloc reaches 0, we must finish what sk_free()
1815 	 * could not do because of in-flight packets
1816 	 */
1817 	if (refcount_sub_and_test(len, &sk->sk_wmem_alloc))
1818 		__sk_free(sk);
1819 }
1820 EXPORT_SYMBOL(sock_wfree);
1821 
1822 /* This variant of sock_wfree() is used by TCP,
1823  * since it sets SOCK_USE_WRITE_QUEUE.
1824  */
1825 void __sock_wfree(struct sk_buff *skb)
1826 {
1827 	struct sock *sk = skb->sk;
1828 
1829 	if (refcount_sub_and_test(skb->truesize, &sk->sk_wmem_alloc))
1830 		__sk_free(sk);
1831 }
1832 
1833 void skb_set_owner_w(struct sk_buff *skb, struct sock *sk)
1834 {
1835 	skb_orphan(skb);
1836 	skb->sk = sk;
1837 #ifdef CONFIG_INET
1838 	if (unlikely(!sk_fullsock(sk))) {
1839 		skb->destructor = sock_edemux;
1840 		sock_hold(sk);
1841 		return;
1842 	}
1843 #endif
1844 	skb->destructor = sock_wfree;
1845 	skb_set_hash_from_sk(skb, sk);
1846 	/*
1847 	 * We used to take a refcount on sk, but following operation
1848 	 * is enough to guarantee sk_free() wont free this sock until
1849 	 * all in-flight packets are completed
1850 	 */
1851 	refcount_add(skb->truesize, &sk->sk_wmem_alloc);
1852 }
1853 EXPORT_SYMBOL(skb_set_owner_w);
1854 
1855 /* This helper is used by netem, as it can hold packets in its
1856  * delay queue. We want to allow the owner socket to send more
1857  * packets, as if they were already TX completed by a typical driver.
1858  * But we also want to keep skb->sk set because some packet schedulers
1859  * rely on it (sch_fq for example).
1860  */
1861 void skb_orphan_partial(struct sk_buff *skb)
1862 {
1863 	if (skb_is_tcp_pure_ack(skb))
1864 		return;
1865 
1866 	if (skb->destructor == sock_wfree
1867 #ifdef CONFIG_INET
1868 	    || skb->destructor == tcp_wfree
1869 #endif
1870 		) {
1871 		struct sock *sk = skb->sk;
1872 
1873 		if (refcount_inc_not_zero(&sk->sk_refcnt)) {
1874 			WARN_ON(refcount_sub_and_test(skb->truesize, &sk->sk_wmem_alloc));
1875 			skb->destructor = sock_efree;
1876 		}
1877 	} else {
1878 		skb_orphan(skb);
1879 	}
1880 }
1881 EXPORT_SYMBOL(skb_orphan_partial);
1882 
1883 /*
1884  * Read buffer destructor automatically called from kfree_skb.
1885  */
1886 void sock_rfree(struct sk_buff *skb)
1887 {
1888 	struct sock *sk = skb->sk;
1889 	unsigned int len = skb->truesize;
1890 
1891 	atomic_sub(len, &sk->sk_rmem_alloc);
1892 	sk_mem_uncharge(sk, len);
1893 }
1894 EXPORT_SYMBOL(sock_rfree);
1895 
1896 /*
1897  * Buffer destructor for skbs that are not used directly in read or write
1898  * path, e.g. for error handler skbs. Automatically called from kfree_skb.
1899  */
1900 void sock_efree(struct sk_buff *skb)
1901 {
1902 	sock_put(skb->sk);
1903 }
1904 EXPORT_SYMBOL(sock_efree);
1905 
1906 kuid_t sock_i_uid(struct sock *sk)
1907 {
1908 	kuid_t uid;
1909 
1910 	read_lock_bh(&sk->sk_callback_lock);
1911 	uid = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_uid : GLOBAL_ROOT_UID;
1912 	read_unlock_bh(&sk->sk_callback_lock);
1913 	return uid;
1914 }
1915 EXPORT_SYMBOL(sock_i_uid);
1916 
1917 unsigned long sock_i_ino(struct sock *sk)
1918 {
1919 	unsigned long ino;
1920 
1921 	read_lock_bh(&sk->sk_callback_lock);
1922 	ino = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_ino : 0;
1923 	read_unlock_bh(&sk->sk_callback_lock);
1924 	return ino;
1925 }
1926 EXPORT_SYMBOL(sock_i_ino);
1927 
1928 /*
1929  * Allocate a skb from the socket's send buffer.
1930  */
1931 struct sk_buff *sock_wmalloc(struct sock *sk, unsigned long size, int force,
1932 			     gfp_t priority)
1933 {
1934 	if (force || refcount_read(&sk->sk_wmem_alloc) < sk->sk_sndbuf) {
1935 		struct sk_buff *skb = alloc_skb(size, priority);
1936 		if (skb) {
1937 			skb_set_owner_w(skb, sk);
1938 			return skb;
1939 		}
1940 	}
1941 	return NULL;
1942 }
1943 EXPORT_SYMBOL(sock_wmalloc);
1944 
1945 static void sock_ofree(struct sk_buff *skb)
1946 {
1947 	struct sock *sk = skb->sk;
1948 
1949 	atomic_sub(skb->truesize, &sk->sk_omem_alloc);
1950 }
1951 
1952 struct sk_buff *sock_omalloc(struct sock *sk, unsigned long size,
1953 			     gfp_t priority)
1954 {
1955 	struct sk_buff *skb;
1956 
1957 	/* small safe race: SKB_TRUESIZE may differ from final skb->truesize */
1958 	if (atomic_read(&sk->sk_omem_alloc) + SKB_TRUESIZE(size) >
1959 	    sysctl_optmem_max)
1960 		return NULL;
1961 
1962 	skb = alloc_skb(size, priority);
1963 	if (!skb)
1964 		return NULL;
1965 
1966 	atomic_add(skb->truesize, &sk->sk_omem_alloc);
1967 	skb->sk = sk;
1968 	skb->destructor = sock_ofree;
1969 	return skb;
1970 }
1971 
1972 /*
1973  * Allocate a memory block from the socket's option memory buffer.
1974  */
1975 void *sock_kmalloc(struct sock *sk, int size, gfp_t priority)
1976 {
1977 	if ((unsigned int)size <= sysctl_optmem_max &&
1978 	    atomic_read(&sk->sk_omem_alloc) + size < sysctl_optmem_max) {
1979 		void *mem;
1980 		/* First do the add, to avoid the race if kmalloc
1981 		 * might sleep.
1982 		 */
1983 		atomic_add(size, &sk->sk_omem_alloc);
1984 		mem = kmalloc(size, priority);
1985 		if (mem)
1986 			return mem;
1987 		atomic_sub(size, &sk->sk_omem_alloc);
1988 	}
1989 	return NULL;
1990 }
1991 EXPORT_SYMBOL(sock_kmalloc);
1992 
1993 /* Free an option memory block. Note, we actually want the inline
1994  * here as this allows gcc to detect the nullify and fold away the
1995  * condition entirely.
1996  */
1997 static inline void __sock_kfree_s(struct sock *sk, void *mem, int size,
1998 				  const bool nullify)
1999 {
2000 	if (WARN_ON_ONCE(!mem))
2001 		return;
2002 	if (nullify)
2003 		kzfree(mem);
2004 	else
2005 		kfree(mem);
2006 	atomic_sub(size, &sk->sk_omem_alloc);
2007 }
2008 
2009 void sock_kfree_s(struct sock *sk, void *mem, int size)
2010 {
2011 	__sock_kfree_s(sk, mem, size, false);
2012 }
2013 EXPORT_SYMBOL(sock_kfree_s);
2014 
2015 void sock_kzfree_s(struct sock *sk, void *mem, int size)
2016 {
2017 	__sock_kfree_s(sk, mem, size, true);
2018 }
2019 EXPORT_SYMBOL(sock_kzfree_s);
2020 
2021 /* It is almost wait_for_tcp_memory minus release_sock/lock_sock.
2022    I think, these locks should be removed for datagram sockets.
2023  */
2024 static long sock_wait_for_wmem(struct sock *sk, long timeo)
2025 {
2026 	DEFINE_WAIT(wait);
2027 
2028 	sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
2029 	for (;;) {
2030 		if (!timeo)
2031 			break;
2032 		if (signal_pending(current))
2033 			break;
2034 		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
2035 		prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
2036 		if (refcount_read(&sk->sk_wmem_alloc) < sk->sk_sndbuf)
2037 			break;
2038 		if (sk->sk_shutdown & SEND_SHUTDOWN)
2039 			break;
2040 		if (sk->sk_err)
2041 			break;
2042 		timeo = schedule_timeout(timeo);
2043 	}
2044 	finish_wait(sk_sleep(sk), &wait);
2045 	return timeo;
2046 }
2047 
2048 
2049 /*
2050  *	Generic send/receive buffer handlers
2051  */
2052 
2053 struct sk_buff *sock_alloc_send_pskb(struct sock *sk, unsigned long header_len,
2054 				     unsigned long data_len, int noblock,
2055 				     int *errcode, int max_page_order)
2056 {
2057 	struct sk_buff *skb;
2058 	long timeo;
2059 	int err;
2060 
2061 	timeo = sock_sndtimeo(sk, noblock);
2062 	for (;;) {
2063 		err = sock_error(sk);
2064 		if (err != 0)
2065 			goto failure;
2066 
2067 		err = -EPIPE;
2068 		if (sk->sk_shutdown & SEND_SHUTDOWN)
2069 			goto failure;
2070 
2071 		if (sk_wmem_alloc_get(sk) < sk->sk_sndbuf)
2072 			break;
2073 
2074 		sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
2075 		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
2076 		err = -EAGAIN;
2077 		if (!timeo)
2078 			goto failure;
2079 		if (signal_pending(current))
2080 			goto interrupted;
2081 		timeo = sock_wait_for_wmem(sk, timeo);
2082 	}
2083 	skb = alloc_skb_with_frags(header_len, data_len, max_page_order,
2084 				   errcode, sk->sk_allocation);
2085 	if (skb)
2086 		skb_set_owner_w(skb, sk);
2087 	return skb;
2088 
2089 interrupted:
2090 	err = sock_intr_errno(timeo);
2091 failure:
2092 	*errcode = err;
2093 	return NULL;
2094 }
2095 EXPORT_SYMBOL(sock_alloc_send_pskb);
2096 
2097 struct sk_buff *sock_alloc_send_skb(struct sock *sk, unsigned long size,
2098 				    int noblock, int *errcode)
2099 {
2100 	return sock_alloc_send_pskb(sk, size, 0, noblock, errcode, 0);
2101 }
2102 EXPORT_SYMBOL(sock_alloc_send_skb);
2103 
2104 int __sock_cmsg_send(struct sock *sk, struct msghdr *msg, struct cmsghdr *cmsg,
2105 		     struct sockcm_cookie *sockc)
2106 {
2107 	u32 tsflags;
2108 
2109 	switch (cmsg->cmsg_type) {
2110 	case SO_MARK:
2111 		if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
2112 			return -EPERM;
2113 		if (cmsg->cmsg_len != CMSG_LEN(sizeof(u32)))
2114 			return -EINVAL;
2115 		sockc->mark = *(u32 *)CMSG_DATA(cmsg);
2116 		break;
2117 	case SO_TIMESTAMPING:
2118 		if (cmsg->cmsg_len != CMSG_LEN(sizeof(u32)))
2119 			return -EINVAL;
2120 
2121 		tsflags = *(u32 *)CMSG_DATA(cmsg);
2122 		if (tsflags & ~SOF_TIMESTAMPING_TX_RECORD_MASK)
2123 			return -EINVAL;
2124 
2125 		sockc->tsflags &= ~SOF_TIMESTAMPING_TX_RECORD_MASK;
2126 		sockc->tsflags |= tsflags;
2127 		break;
2128 	case SCM_TXTIME:
2129 		if (!sock_flag(sk, SOCK_TXTIME))
2130 			return -EINVAL;
2131 		if (cmsg->cmsg_len != CMSG_LEN(sizeof(u64)))
2132 			return -EINVAL;
2133 		sockc->transmit_time = get_unaligned((u64 *)CMSG_DATA(cmsg));
2134 		break;
2135 	/* SCM_RIGHTS and SCM_CREDENTIALS are semantically in SOL_UNIX. */
2136 	case SCM_RIGHTS:
2137 	case SCM_CREDENTIALS:
2138 		break;
2139 	default:
2140 		return -EINVAL;
2141 	}
2142 	return 0;
2143 }
2144 EXPORT_SYMBOL(__sock_cmsg_send);
2145 
2146 int sock_cmsg_send(struct sock *sk, struct msghdr *msg,
2147 		   struct sockcm_cookie *sockc)
2148 {
2149 	struct cmsghdr *cmsg;
2150 	int ret;
2151 
2152 	for_each_cmsghdr(cmsg, msg) {
2153 		if (!CMSG_OK(msg, cmsg))
2154 			return -EINVAL;
2155 		if (cmsg->cmsg_level != SOL_SOCKET)
2156 			continue;
2157 		ret = __sock_cmsg_send(sk, msg, cmsg, sockc);
2158 		if (ret)
2159 			return ret;
2160 	}
2161 	return 0;
2162 }
2163 EXPORT_SYMBOL(sock_cmsg_send);
2164 
2165 static void sk_enter_memory_pressure(struct sock *sk)
2166 {
2167 	if (!sk->sk_prot->enter_memory_pressure)
2168 		return;
2169 
2170 	sk->sk_prot->enter_memory_pressure(sk);
2171 }
2172 
2173 static void sk_leave_memory_pressure(struct sock *sk)
2174 {
2175 	if (sk->sk_prot->leave_memory_pressure) {
2176 		sk->sk_prot->leave_memory_pressure(sk);
2177 	} else {
2178 		unsigned long *memory_pressure = sk->sk_prot->memory_pressure;
2179 
2180 		if (memory_pressure && *memory_pressure)
2181 			*memory_pressure = 0;
2182 	}
2183 }
2184 
2185 /* On 32bit arches, an skb frag is limited to 2^15 */
2186 #define SKB_FRAG_PAGE_ORDER	get_order(32768)
2187 
2188 /**
2189  * skb_page_frag_refill - check that a page_frag contains enough room
2190  * @sz: minimum size of the fragment we want to get
2191  * @pfrag: pointer to page_frag
2192  * @gfp: priority for memory allocation
2193  *
2194  * Note: While this allocator tries to use high order pages, there is
2195  * no guarantee that allocations succeed. Therefore, @sz MUST be
2196  * less or equal than PAGE_SIZE.
2197  */
2198 bool skb_page_frag_refill(unsigned int sz, struct page_frag *pfrag, gfp_t gfp)
2199 {
2200 	if (pfrag->page) {
2201 		if (page_ref_count(pfrag->page) == 1) {
2202 			pfrag->offset = 0;
2203 			return true;
2204 		}
2205 		if (pfrag->offset + sz <= pfrag->size)
2206 			return true;
2207 		put_page(pfrag->page);
2208 	}
2209 
2210 	pfrag->offset = 0;
2211 	if (SKB_FRAG_PAGE_ORDER) {
2212 		/* Avoid direct reclaim but allow kswapd to wake */
2213 		pfrag->page = alloc_pages((gfp & ~__GFP_DIRECT_RECLAIM) |
2214 					  __GFP_COMP | __GFP_NOWARN |
2215 					  __GFP_NORETRY,
2216 					  SKB_FRAG_PAGE_ORDER);
2217 		if (likely(pfrag->page)) {
2218 			pfrag->size = PAGE_SIZE << SKB_FRAG_PAGE_ORDER;
2219 			return true;
2220 		}
2221 	}
2222 	pfrag->page = alloc_page(gfp);
2223 	if (likely(pfrag->page)) {
2224 		pfrag->size = PAGE_SIZE;
2225 		return true;
2226 	}
2227 	return false;
2228 }
2229 EXPORT_SYMBOL(skb_page_frag_refill);
2230 
2231 bool sk_page_frag_refill(struct sock *sk, struct page_frag *pfrag)
2232 {
2233 	if (likely(skb_page_frag_refill(32U, pfrag, sk->sk_allocation)))
2234 		return true;
2235 
2236 	sk_enter_memory_pressure(sk);
2237 	sk_stream_moderate_sndbuf(sk);
2238 	return false;
2239 }
2240 EXPORT_SYMBOL(sk_page_frag_refill);
2241 
2242 int sk_alloc_sg(struct sock *sk, int len, struct scatterlist *sg,
2243 		int sg_start, int *sg_curr_index, unsigned int *sg_curr_size,
2244 		int first_coalesce)
2245 {
2246 	int sg_curr = *sg_curr_index, use = 0, rc = 0;
2247 	unsigned int size = *sg_curr_size;
2248 	struct page_frag *pfrag;
2249 	struct scatterlist *sge;
2250 
2251 	len -= size;
2252 	pfrag = sk_page_frag(sk);
2253 
2254 	while (len > 0) {
2255 		unsigned int orig_offset;
2256 
2257 		if (!sk_page_frag_refill(sk, pfrag)) {
2258 			rc = -ENOMEM;
2259 			goto out;
2260 		}
2261 
2262 		use = min_t(int, len, pfrag->size - pfrag->offset);
2263 
2264 		if (!sk_wmem_schedule(sk, use)) {
2265 			rc = -ENOMEM;
2266 			goto out;
2267 		}
2268 
2269 		sk_mem_charge(sk, use);
2270 		size += use;
2271 		orig_offset = pfrag->offset;
2272 		pfrag->offset += use;
2273 
2274 		sge = sg + sg_curr - 1;
2275 		if (sg_curr > first_coalesce && sg_page(sge) == pfrag->page &&
2276 		    sge->offset + sge->length == orig_offset) {
2277 			sge->length += use;
2278 		} else {
2279 			sge = sg + sg_curr;
2280 			sg_unmark_end(sge);
2281 			sg_set_page(sge, pfrag->page, use, orig_offset);
2282 			get_page(pfrag->page);
2283 			sg_curr++;
2284 
2285 			if (sg_curr == MAX_SKB_FRAGS)
2286 				sg_curr = 0;
2287 
2288 			if (sg_curr == sg_start) {
2289 				rc = -ENOSPC;
2290 				break;
2291 			}
2292 		}
2293 
2294 		len -= use;
2295 	}
2296 out:
2297 	*sg_curr_size = size;
2298 	*sg_curr_index = sg_curr;
2299 	return rc;
2300 }
2301 EXPORT_SYMBOL(sk_alloc_sg);
2302 
2303 static void __lock_sock(struct sock *sk)
2304 	__releases(&sk->sk_lock.slock)
2305 	__acquires(&sk->sk_lock.slock)
2306 {
2307 	DEFINE_WAIT(wait);
2308 
2309 	for (;;) {
2310 		prepare_to_wait_exclusive(&sk->sk_lock.wq, &wait,
2311 					TASK_UNINTERRUPTIBLE);
2312 		spin_unlock_bh(&sk->sk_lock.slock);
2313 		schedule();
2314 		spin_lock_bh(&sk->sk_lock.slock);
2315 		if (!sock_owned_by_user(sk))
2316 			break;
2317 	}
2318 	finish_wait(&sk->sk_lock.wq, &wait);
2319 }
2320 
2321 void __release_sock(struct sock *sk)
2322 	__releases(&sk->sk_lock.slock)
2323 	__acquires(&sk->sk_lock.slock)
2324 {
2325 	struct sk_buff *skb, *next;
2326 
2327 	while ((skb = sk->sk_backlog.head) != NULL) {
2328 		sk->sk_backlog.head = sk->sk_backlog.tail = NULL;
2329 
2330 		spin_unlock_bh(&sk->sk_lock.slock);
2331 
2332 		do {
2333 			next = skb->next;
2334 			prefetch(next);
2335 			WARN_ON_ONCE(skb_dst_is_noref(skb));
2336 			skb_mark_not_on_list(skb);
2337 			sk_backlog_rcv(sk, skb);
2338 
2339 			cond_resched();
2340 
2341 			skb = next;
2342 		} while (skb != NULL);
2343 
2344 		spin_lock_bh(&sk->sk_lock.slock);
2345 	}
2346 
2347 	/*
2348 	 * Doing the zeroing here guarantee we can not loop forever
2349 	 * while a wild producer attempts to flood us.
2350 	 */
2351 	sk->sk_backlog.len = 0;
2352 }
2353 
2354 void __sk_flush_backlog(struct sock *sk)
2355 {
2356 	spin_lock_bh(&sk->sk_lock.slock);
2357 	__release_sock(sk);
2358 	spin_unlock_bh(&sk->sk_lock.slock);
2359 }
2360 
2361 /**
2362  * sk_wait_data - wait for data to arrive at sk_receive_queue
2363  * @sk:    sock to wait on
2364  * @timeo: for how long
2365  * @skb:   last skb seen on sk_receive_queue
2366  *
2367  * Now socket state including sk->sk_err is changed only under lock,
2368  * hence we may omit checks after joining wait queue.
2369  * We check receive queue before schedule() only as optimization;
2370  * it is very likely that release_sock() added new data.
2371  */
2372 int sk_wait_data(struct sock *sk, long *timeo, const struct sk_buff *skb)
2373 {
2374 	DEFINE_WAIT_FUNC(wait, woken_wake_function);
2375 	int rc;
2376 
2377 	add_wait_queue(sk_sleep(sk), &wait);
2378 	sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
2379 	rc = sk_wait_event(sk, timeo, skb_peek_tail(&sk->sk_receive_queue) != skb, &wait);
2380 	sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
2381 	remove_wait_queue(sk_sleep(sk), &wait);
2382 	return rc;
2383 }
2384 EXPORT_SYMBOL(sk_wait_data);
2385 
2386 /**
2387  *	__sk_mem_raise_allocated - increase memory_allocated
2388  *	@sk: socket
2389  *	@size: memory size to allocate
2390  *	@amt: pages to allocate
2391  *	@kind: allocation type
2392  *
2393  *	Similar to __sk_mem_schedule(), but does not update sk_forward_alloc
2394  */
2395 int __sk_mem_raise_allocated(struct sock *sk, int size, int amt, int kind)
2396 {
2397 	struct proto *prot = sk->sk_prot;
2398 	long allocated = sk_memory_allocated_add(sk, amt);
2399 	bool charged = true;
2400 
2401 	if (mem_cgroup_sockets_enabled && sk->sk_memcg &&
2402 	    !(charged = mem_cgroup_charge_skmem(sk->sk_memcg, amt)))
2403 		goto suppress_allocation;
2404 
2405 	/* Under limit. */
2406 	if (allocated <= sk_prot_mem_limits(sk, 0)) {
2407 		sk_leave_memory_pressure(sk);
2408 		return 1;
2409 	}
2410 
2411 	/* Under pressure. */
2412 	if (allocated > sk_prot_mem_limits(sk, 1))
2413 		sk_enter_memory_pressure(sk);
2414 
2415 	/* Over hard limit. */
2416 	if (allocated > sk_prot_mem_limits(sk, 2))
2417 		goto suppress_allocation;
2418 
2419 	/* guarantee minimum buffer size under pressure */
2420 	if (kind == SK_MEM_RECV) {
2421 		if (atomic_read(&sk->sk_rmem_alloc) < sk_get_rmem0(sk, prot))
2422 			return 1;
2423 
2424 	} else { /* SK_MEM_SEND */
2425 		int wmem0 = sk_get_wmem0(sk, prot);
2426 
2427 		if (sk->sk_type == SOCK_STREAM) {
2428 			if (sk->sk_wmem_queued < wmem0)
2429 				return 1;
2430 		} else if (refcount_read(&sk->sk_wmem_alloc) < wmem0) {
2431 				return 1;
2432 		}
2433 	}
2434 
2435 	if (sk_has_memory_pressure(sk)) {
2436 		int alloc;
2437 
2438 		if (!sk_under_memory_pressure(sk))
2439 			return 1;
2440 		alloc = sk_sockets_allocated_read_positive(sk);
2441 		if (sk_prot_mem_limits(sk, 2) > alloc *
2442 		    sk_mem_pages(sk->sk_wmem_queued +
2443 				 atomic_read(&sk->sk_rmem_alloc) +
2444 				 sk->sk_forward_alloc))
2445 			return 1;
2446 	}
2447 
2448 suppress_allocation:
2449 
2450 	if (kind == SK_MEM_SEND && sk->sk_type == SOCK_STREAM) {
2451 		sk_stream_moderate_sndbuf(sk);
2452 
2453 		/* Fail only if socket is _under_ its sndbuf.
2454 		 * In this case we cannot block, so that we have to fail.
2455 		 */
2456 		if (sk->sk_wmem_queued + size >= sk->sk_sndbuf)
2457 			return 1;
2458 	}
2459 
2460 	if (kind == SK_MEM_SEND || (kind == SK_MEM_RECV && charged))
2461 		trace_sock_exceed_buf_limit(sk, prot, allocated, kind);
2462 
2463 	sk_memory_allocated_sub(sk, amt);
2464 
2465 	if (mem_cgroup_sockets_enabled && sk->sk_memcg)
2466 		mem_cgroup_uncharge_skmem(sk->sk_memcg, amt);
2467 
2468 	return 0;
2469 }
2470 EXPORT_SYMBOL(__sk_mem_raise_allocated);
2471 
2472 /**
2473  *	__sk_mem_schedule - increase sk_forward_alloc and memory_allocated
2474  *	@sk: socket
2475  *	@size: memory size to allocate
2476  *	@kind: allocation type
2477  *
2478  *	If kind is SK_MEM_SEND, it means wmem allocation. Otherwise it means
2479  *	rmem allocation. This function assumes that protocols which have
2480  *	memory_pressure use sk_wmem_queued as write buffer accounting.
2481  */
2482 int __sk_mem_schedule(struct sock *sk, int size, int kind)
2483 {
2484 	int ret, amt = sk_mem_pages(size);
2485 
2486 	sk->sk_forward_alloc += amt << SK_MEM_QUANTUM_SHIFT;
2487 	ret = __sk_mem_raise_allocated(sk, size, amt, kind);
2488 	if (!ret)
2489 		sk->sk_forward_alloc -= amt << SK_MEM_QUANTUM_SHIFT;
2490 	return ret;
2491 }
2492 EXPORT_SYMBOL(__sk_mem_schedule);
2493 
2494 /**
2495  *	__sk_mem_reduce_allocated - reclaim memory_allocated
2496  *	@sk: socket
2497  *	@amount: number of quanta
2498  *
2499  *	Similar to __sk_mem_reclaim(), but does not update sk_forward_alloc
2500  */
2501 void __sk_mem_reduce_allocated(struct sock *sk, int amount)
2502 {
2503 	sk_memory_allocated_sub(sk, amount);
2504 
2505 	if (mem_cgroup_sockets_enabled && sk->sk_memcg)
2506 		mem_cgroup_uncharge_skmem(sk->sk_memcg, amount);
2507 
2508 	if (sk_under_memory_pressure(sk) &&
2509 	    (sk_memory_allocated(sk) < sk_prot_mem_limits(sk, 0)))
2510 		sk_leave_memory_pressure(sk);
2511 }
2512 EXPORT_SYMBOL(__sk_mem_reduce_allocated);
2513 
2514 /**
2515  *	__sk_mem_reclaim - reclaim sk_forward_alloc and memory_allocated
2516  *	@sk: socket
2517  *	@amount: number of bytes (rounded down to a SK_MEM_QUANTUM multiple)
2518  */
2519 void __sk_mem_reclaim(struct sock *sk, int amount)
2520 {
2521 	amount >>= SK_MEM_QUANTUM_SHIFT;
2522 	sk->sk_forward_alloc -= amount << SK_MEM_QUANTUM_SHIFT;
2523 	__sk_mem_reduce_allocated(sk, amount);
2524 }
2525 EXPORT_SYMBOL(__sk_mem_reclaim);
2526 
2527 int sk_set_peek_off(struct sock *sk, int val)
2528 {
2529 	sk->sk_peek_off = val;
2530 	return 0;
2531 }
2532 EXPORT_SYMBOL_GPL(sk_set_peek_off);
2533 
2534 /*
2535  * Set of default routines for initialising struct proto_ops when
2536  * the protocol does not support a particular function. In certain
2537  * cases where it makes no sense for a protocol to have a "do nothing"
2538  * function, some default processing is provided.
2539  */
2540 
2541 int sock_no_bind(struct socket *sock, struct sockaddr *saddr, int len)
2542 {
2543 	return -EOPNOTSUPP;
2544 }
2545 EXPORT_SYMBOL(sock_no_bind);
2546 
2547 int sock_no_connect(struct socket *sock, struct sockaddr *saddr,
2548 		    int len, int flags)
2549 {
2550 	return -EOPNOTSUPP;
2551 }
2552 EXPORT_SYMBOL(sock_no_connect);
2553 
2554 int sock_no_socketpair(struct socket *sock1, struct socket *sock2)
2555 {
2556 	return -EOPNOTSUPP;
2557 }
2558 EXPORT_SYMBOL(sock_no_socketpair);
2559 
2560 int sock_no_accept(struct socket *sock, struct socket *newsock, int flags,
2561 		   bool kern)
2562 {
2563 	return -EOPNOTSUPP;
2564 }
2565 EXPORT_SYMBOL(sock_no_accept);
2566 
2567 int sock_no_getname(struct socket *sock, struct sockaddr *saddr,
2568 		    int peer)
2569 {
2570 	return -EOPNOTSUPP;
2571 }
2572 EXPORT_SYMBOL(sock_no_getname);
2573 
2574 int sock_no_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
2575 {
2576 	return -EOPNOTSUPP;
2577 }
2578 EXPORT_SYMBOL(sock_no_ioctl);
2579 
2580 int sock_no_listen(struct socket *sock, int backlog)
2581 {
2582 	return -EOPNOTSUPP;
2583 }
2584 EXPORT_SYMBOL(sock_no_listen);
2585 
2586 int sock_no_shutdown(struct socket *sock, int how)
2587 {
2588 	return -EOPNOTSUPP;
2589 }
2590 EXPORT_SYMBOL(sock_no_shutdown);
2591 
2592 int sock_no_setsockopt(struct socket *sock, int level, int optname,
2593 		    char __user *optval, unsigned int optlen)
2594 {
2595 	return -EOPNOTSUPP;
2596 }
2597 EXPORT_SYMBOL(sock_no_setsockopt);
2598 
2599 int sock_no_getsockopt(struct socket *sock, int level, int optname,
2600 		    char __user *optval, int __user *optlen)
2601 {
2602 	return -EOPNOTSUPP;
2603 }
2604 EXPORT_SYMBOL(sock_no_getsockopt);
2605 
2606 int sock_no_sendmsg(struct socket *sock, struct msghdr *m, size_t len)
2607 {
2608 	return -EOPNOTSUPP;
2609 }
2610 EXPORT_SYMBOL(sock_no_sendmsg);
2611 
2612 int sock_no_sendmsg_locked(struct sock *sk, struct msghdr *m, size_t len)
2613 {
2614 	return -EOPNOTSUPP;
2615 }
2616 EXPORT_SYMBOL(sock_no_sendmsg_locked);
2617 
2618 int sock_no_recvmsg(struct socket *sock, struct msghdr *m, size_t len,
2619 		    int flags)
2620 {
2621 	return -EOPNOTSUPP;
2622 }
2623 EXPORT_SYMBOL(sock_no_recvmsg);
2624 
2625 int sock_no_mmap(struct file *file, struct socket *sock, struct vm_area_struct *vma)
2626 {
2627 	/* Mirror missing mmap method error code */
2628 	return -ENODEV;
2629 }
2630 EXPORT_SYMBOL(sock_no_mmap);
2631 
2632 ssize_t sock_no_sendpage(struct socket *sock, struct page *page, int offset, size_t size, int flags)
2633 {
2634 	ssize_t res;
2635 	struct msghdr msg = {.msg_flags = flags};
2636 	struct kvec iov;
2637 	char *kaddr = kmap(page);
2638 	iov.iov_base = kaddr + offset;
2639 	iov.iov_len = size;
2640 	res = kernel_sendmsg(sock, &msg, &iov, 1, size);
2641 	kunmap(page);
2642 	return res;
2643 }
2644 EXPORT_SYMBOL(sock_no_sendpage);
2645 
2646 ssize_t sock_no_sendpage_locked(struct sock *sk, struct page *page,
2647 				int offset, size_t size, int flags)
2648 {
2649 	ssize_t res;
2650 	struct msghdr msg = {.msg_flags = flags};
2651 	struct kvec iov;
2652 	char *kaddr = kmap(page);
2653 
2654 	iov.iov_base = kaddr + offset;
2655 	iov.iov_len = size;
2656 	res = kernel_sendmsg_locked(sk, &msg, &iov, 1, size);
2657 	kunmap(page);
2658 	return res;
2659 }
2660 EXPORT_SYMBOL(sock_no_sendpage_locked);
2661 
2662 /*
2663  *	Default Socket Callbacks
2664  */
2665 
2666 static void sock_def_wakeup(struct sock *sk)
2667 {
2668 	struct socket_wq *wq;
2669 
2670 	rcu_read_lock();
2671 	wq = rcu_dereference(sk->sk_wq);
2672 	if (skwq_has_sleeper(wq))
2673 		wake_up_interruptible_all(&wq->wait);
2674 	rcu_read_unlock();
2675 }
2676 
2677 static void sock_def_error_report(struct sock *sk)
2678 {
2679 	struct socket_wq *wq;
2680 
2681 	rcu_read_lock();
2682 	wq = rcu_dereference(sk->sk_wq);
2683 	if (skwq_has_sleeper(wq))
2684 		wake_up_interruptible_poll(&wq->wait, EPOLLERR);
2685 	sk_wake_async(sk, SOCK_WAKE_IO, POLL_ERR);
2686 	rcu_read_unlock();
2687 }
2688 
2689 static void sock_def_readable(struct sock *sk)
2690 {
2691 	struct socket_wq *wq;
2692 
2693 	rcu_read_lock();
2694 	wq = rcu_dereference(sk->sk_wq);
2695 	if (skwq_has_sleeper(wq))
2696 		wake_up_interruptible_sync_poll(&wq->wait, EPOLLIN | EPOLLPRI |
2697 						EPOLLRDNORM | EPOLLRDBAND);
2698 	sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
2699 	rcu_read_unlock();
2700 }
2701 
2702 static void sock_def_write_space(struct sock *sk)
2703 {
2704 	struct socket_wq *wq;
2705 
2706 	rcu_read_lock();
2707 
2708 	/* Do not wake up a writer until he can make "significant"
2709 	 * progress.  --DaveM
2710 	 */
2711 	if ((refcount_read(&sk->sk_wmem_alloc) << 1) <= sk->sk_sndbuf) {
2712 		wq = rcu_dereference(sk->sk_wq);
2713 		if (skwq_has_sleeper(wq))
2714 			wake_up_interruptible_sync_poll(&wq->wait, EPOLLOUT |
2715 						EPOLLWRNORM | EPOLLWRBAND);
2716 
2717 		/* Should agree with poll, otherwise some programs break */
2718 		if (sock_writeable(sk))
2719 			sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
2720 	}
2721 
2722 	rcu_read_unlock();
2723 }
2724 
2725 static void sock_def_destruct(struct sock *sk)
2726 {
2727 }
2728 
2729 void sk_send_sigurg(struct sock *sk)
2730 {
2731 	if (sk->sk_socket && sk->sk_socket->file)
2732 		if (send_sigurg(&sk->sk_socket->file->f_owner))
2733 			sk_wake_async(sk, SOCK_WAKE_URG, POLL_PRI);
2734 }
2735 EXPORT_SYMBOL(sk_send_sigurg);
2736 
2737 void sk_reset_timer(struct sock *sk, struct timer_list* timer,
2738 		    unsigned long expires)
2739 {
2740 	if (!mod_timer(timer, expires))
2741 		sock_hold(sk);
2742 }
2743 EXPORT_SYMBOL(sk_reset_timer);
2744 
2745 void sk_stop_timer(struct sock *sk, struct timer_list* timer)
2746 {
2747 	if (del_timer(timer))
2748 		__sock_put(sk);
2749 }
2750 EXPORT_SYMBOL(sk_stop_timer);
2751 
2752 void sock_init_data(struct socket *sock, struct sock *sk)
2753 {
2754 	sk_init_common(sk);
2755 	sk->sk_send_head	=	NULL;
2756 
2757 	timer_setup(&sk->sk_timer, NULL, 0);
2758 
2759 	sk->sk_allocation	=	GFP_KERNEL;
2760 	sk->sk_rcvbuf		=	sysctl_rmem_default;
2761 	sk->sk_sndbuf		=	sysctl_wmem_default;
2762 	sk->sk_state		=	TCP_CLOSE;
2763 	sk_set_socket(sk, sock);
2764 
2765 	sock_set_flag(sk, SOCK_ZAPPED);
2766 
2767 	if (sock) {
2768 		sk->sk_type	=	sock->type;
2769 		sk->sk_wq	=	sock->wq;
2770 		sock->sk	=	sk;
2771 		sk->sk_uid	=	SOCK_INODE(sock)->i_uid;
2772 	} else {
2773 		sk->sk_wq	=	NULL;
2774 		sk->sk_uid	=	make_kuid(sock_net(sk)->user_ns, 0);
2775 	}
2776 
2777 	rwlock_init(&sk->sk_callback_lock);
2778 	if (sk->sk_kern_sock)
2779 		lockdep_set_class_and_name(
2780 			&sk->sk_callback_lock,
2781 			af_kern_callback_keys + sk->sk_family,
2782 			af_family_kern_clock_key_strings[sk->sk_family]);
2783 	else
2784 		lockdep_set_class_and_name(
2785 			&sk->sk_callback_lock,
2786 			af_callback_keys + sk->sk_family,
2787 			af_family_clock_key_strings[sk->sk_family]);
2788 
2789 	sk->sk_state_change	=	sock_def_wakeup;
2790 	sk->sk_data_ready	=	sock_def_readable;
2791 	sk->sk_write_space	=	sock_def_write_space;
2792 	sk->sk_error_report	=	sock_def_error_report;
2793 	sk->sk_destruct		=	sock_def_destruct;
2794 
2795 	sk->sk_frag.page	=	NULL;
2796 	sk->sk_frag.offset	=	0;
2797 	sk->sk_peek_off		=	-1;
2798 
2799 	sk->sk_peer_pid 	=	NULL;
2800 	sk->sk_peer_cred	=	NULL;
2801 	sk->sk_write_pending	=	0;
2802 	sk->sk_rcvlowat		=	1;
2803 	sk->sk_rcvtimeo		=	MAX_SCHEDULE_TIMEOUT;
2804 	sk->sk_sndtimeo		=	MAX_SCHEDULE_TIMEOUT;
2805 
2806 	sk->sk_stamp = SK_DEFAULT_STAMP;
2807 	atomic_set(&sk->sk_zckey, 0);
2808 
2809 #ifdef CONFIG_NET_RX_BUSY_POLL
2810 	sk->sk_napi_id		=	0;
2811 	sk->sk_ll_usec		=	sysctl_net_busy_read;
2812 #endif
2813 
2814 	sk->sk_max_pacing_rate = ~0UL;
2815 	sk->sk_pacing_rate = ~0UL;
2816 	sk->sk_pacing_shift = 10;
2817 	sk->sk_incoming_cpu = -1;
2818 
2819 	sk_rx_queue_clear(sk);
2820 	/*
2821 	 * Before updating sk_refcnt, we must commit prior changes to memory
2822 	 * (Documentation/RCU/rculist_nulls.txt for details)
2823 	 */
2824 	smp_wmb();
2825 	refcount_set(&sk->sk_refcnt, 1);
2826 	atomic_set(&sk->sk_drops, 0);
2827 }
2828 EXPORT_SYMBOL(sock_init_data);
2829 
2830 void lock_sock_nested(struct sock *sk, int subclass)
2831 {
2832 	might_sleep();
2833 	spin_lock_bh(&sk->sk_lock.slock);
2834 	if (sk->sk_lock.owned)
2835 		__lock_sock(sk);
2836 	sk->sk_lock.owned = 1;
2837 	spin_unlock(&sk->sk_lock.slock);
2838 	/*
2839 	 * The sk_lock has mutex_lock() semantics here:
2840 	 */
2841 	mutex_acquire(&sk->sk_lock.dep_map, subclass, 0, _RET_IP_);
2842 	local_bh_enable();
2843 }
2844 EXPORT_SYMBOL(lock_sock_nested);
2845 
2846 void release_sock(struct sock *sk)
2847 {
2848 	spin_lock_bh(&sk->sk_lock.slock);
2849 	if (sk->sk_backlog.tail)
2850 		__release_sock(sk);
2851 
2852 	/* Warning : release_cb() might need to release sk ownership,
2853 	 * ie call sock_release_ownership(sk) before us.
2854 	 */
2855 	if (sk->sk_prot->release_cb)
2856 		sk->sk_prot->release_cb(sk);
2857 
2858 	sock_release_ownership(sk);
2859 	if (waitqueue_active(&sk->sk_lock.wq))
2860 		wake_up(&sk->sk_lock.wq);
2861 	spin_unlock_bh(&sk->sk_lock.slock);
2862 }
2863 EXPORT_SYMBOL(release_sock);
2864 
2865 /**
2866  * lock_sock_fast - fast version of lock_sock
2867  * @sk: socket
2868  *
2869  * This version should be used for very small section, where process wont block
2870  * return false if fast path is taken:
2871  *
2872  *   sk_lock.slock locked, owned = 0, BH disabled
2873  *
2874  * return true if slow path is taken:
2875  *
2876  *   sk_lock.slock unlocked, owned = 1, BH enabled
2877  */
2878 bool lock_sock_fast(struct sock *sk)
2879 {
2880 	might_sleep();
2881 	spin_lock_bh(&sk->sk_lock.slock);
2882 
2883 	if (!sk->sk_lock.owned)
2884 		/*
2885 		 * Note : We must disable BH
2886 		 */
2887 		return false;
2888 
2889 	__lock_sock(sk);
2890 	sk->sk_lock.owned = 1;
2891 	spin_unlock(&sk->sk_lock.slock);
2892 	/*
2893 	 * The sk_lock has mutex_lock() semantics here:
2894 	 */
2895 	mutex_acquire(&sk->sk_lock.dep_map, 0, 0, _RET_IP_);
2896 	local_bh_enable();
2897 	return true;
2898 }
2899 EXPORT_SYMBOL(lock_sock_fast);
2900 
2901 int sock_get_timestamp(struct sock *sk, struct timeval __user *userstamp)
2902 {
2903 	struct timeval tv;
2904 
2905 	sock_enable_timestamp(sk, SOCK_TIMESTAMP);
2906 	tv = ktime_to_timeval(sk->sk_stamp);
2907 	if (tv.tv_sec == -1)
2908 		return -ENOENT;
2909 	if (tv.tv_sec == 0) {
2910 		sk->sk_stamp = ktime_get_real();
2911 		tv = ktime_to_timeval(sk->sk_stamp);
2912 	}
2913 	return copy_to_user(userstamp, &tv, sizeof(tv)) ? -EFAULT : 0;
2914 }
2915 EXPORT_SYMBOL(sock_get_timestamp);
2916 
2917 int sock_get_timestampns(struct sock *sk, struct timespec __user *userstamp)
2918 {
2919 	struct timespec ts;
2920 
2921 	sock_enable_timestamp(sk, SOCK_TIMESTAMP);
2922 	ts = ktime_to_timespec(sk->sk_stamp);
2923 	if (ts.tv_sec == -1)
2924 		return -ENOENT;
2925 	if (ts.tv_sec == 0) {
2926 		sk->sk_stamp = ktime_get_real();
2927 		ts = ktime_to_timespec(sk->sk_stamp);
2928 	}
2929 	return copy_to_user(userstamp, &ts, sizeof(ts)) ? -EFAULT : 0;
2930 }
2931 EXPORT_SYMBOL(sock_get_timestampns);
2932 
2933 void sock_enable_timestamp(struct sock *sk, int flag)
2934 {
2935 	if (!sock_flag(sk, flag)) {
2936 		unsigned long previous_flags = sk->sk_flags;
2937 
2938 		sock_set_flag(sk, flag);
2939 		/*
2940 		 * we just set one of the two flags which require net
2941 		 * time stamping, but time stamping might have been on
2942 		 * already because of the other one
2943 		 */
2944 		if (sock_needs_netstamp(sk) &&
2945 		    !(previous_flags & SK_FLAGS_TIMESTAMP))
2946 			net_enable_timestamp();
2947 	}
2948 }
2949 
2950 int sock_recv_errqueue(struct sock *sk, struct msghdr *msg, int len,
2951 		       int level, int type)
2952 {
2953 	struct sock_exterr_skb *serr;
2954 	struct sk_buff *skb;
2955 	int copied, err;
2956 
2957 	err = -EAGAIN;
2958 	skb = sock_dequeue_err_skb(sk);
2959 	if (skb == NULL)
2960 		goto out;
2961 
2962 	copied = skb->len;
2963 	if (copied > len) {
2964 		msg->msg_flags |= MSG_TRUNC;
2965 		copied = len;
2966 	}
2967 	err = skb_copy_datagram_msg(skb, 0, msg, copied);
2968 	if (err)
2969 		goto out_free_skb;
2970 
2971 	sock_recv_timestamp(msg, sk, skb);
2972 
2973 	serr = SKB_EXT_ERR(skb);
2974 	put_cmsg(msg, level, type, sizeof(serr->ee), &serr->ee);
2975 
2976 	msg->msg_flags |= MSG_ERRQUEUE;
2977 	err = copied;
2978 
2979 out_free_skb:
2980 	kfree_skb(skb);
2981 out:
2982 	return err;
2983 }
2984 EXPORT_SYMBOL(sock_recv_errqueue);
2985 
2986 /*
2987  *	Get a socket option on an socket.
2988  *
2989  *	FIX: POSIX 1003.1g is very ambiguous here. It states that
2990  *	asynchronous errors should be reported by getsockopt. We assume
2991  *	this means if you specify SO_ERROR (otherwise whats the point of it).
2992  */
2993 int sock_common_getsockopt(struct socket *sock, int level, int optname,
2994 			   char __user *optval, int __user *optlen)
2995 {
2996 	struct sock *sk = sock->sk;
2997 
2998 	return sk->sk_prot->getsockopt(sk, level, optname, optval, optlen);
2999 }
3000 EXPORT_SYMBOL(sock_common_getsockopt);
3001 
3002 #ifdef CONFIG_COMPAT
3003 int compat_sock_common_getsockopt(struct socket *sock, int level, int optname,
3004 				  char __user *optval, int __user *optlen)
3005 {
3006 	struct sock *sk = sock->sk;
3007 
3008 	if (sk->sk_prot->compat_getsockopt != NULL)
3009 		return sk->sk_prot->compat_getsockopt(sk, level, optname,
3010 						      optval, optlen);
3011 	return sk->sk_prot->getsockopt(sk, level, optname, optval, optlen);
3012 }
3013 EXPORT_SYMBOL(compat_sock_common_getsockopt);
3014 #endif
3015 
3016 int sock_common_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
3017 			int flags)
3018 {
3019 	struct sock *sk = sock->sk;
3020 	int addr_len = 0;
3021 	int err;
3022 
3023 	err = sk->sk_prot->recvmsg(sk, msg, size, flags & MSG_DONTWAIT,
3024 				   flags & ~MSG_DONTWAIT, &addr_len);
3025 	if (err >= 0)
3026 		msg->msg_namelen = addr_len;
3027 	return err;
3028 }
3029 EXPORT_SYMBOL(sock_common_recvmsg);
3030 
3031 /*
3032  *	Set socket options on an inet socket.
3033  */
3034 int sock_common_setsockopt(struct socket *sock, int level, int optname,
3035 			   char __user *optval, unsigned int optlen)
3036 {
3037 	struct sock *sk = sock->sk;
3038 
3039 	return sk->sk_prot->setsockopt(sk, level, optname, optval, optlen);
3040 }
3041 EXPORT_SYMBOL(sock_common_setsockopt);
3042 
3043 #ifdef CONFIG_COMPAT
3044 int compat_sock_common_setsockopt(struct socket *sock, int level, int optname,
3045 				  char __user *optval, unsigned int optlen)
3046 {
3047 	struct sock *sk = sock->sk;
3048 
3049 	if (sk->sk_prot->compat_setsockopt != NULL)
3050 		return sk->sk_prot->compat_setsockopt(sk, level, optname,
3051 						      optval, optlen);
3052 	return sk->sk_prot->setsockopt(sk, level, optname, optval, optlen);
3053 }
3054 EXPORT_SYMBOL(compat_sock_common_setsockopt);
3055 #endif
3056 
3057 void sk_common_release(struct sock *sk)
3058 {
3059 	if (sk->sk_prot->destroy)
3060 		sk->sk_prot->destroy(sk);
3061 
3062 	/*
3063 	 * Observation: when sock_common_release is called, processes have
3064 	 * no access to socket. But net still has.
3065 	 * Step one, detach it from networking:
3066 	 *
3067 	 * A. Remove from hash tables.
3068 	 */
3069 
3070 	sk->sk_prot->unhash(sk);
3071 
3072 	/*
3073 	 * In this point socket cannot receive new packets, but it is possible
3074 	 * that some packets are in flight because some CPU runs receiver and
3075 	 * did hash table lookup before we unhashed socket. They will achieve
3076 	 * receive queue and will be purged by socket destructor.
3077 	 *
3078 	 * Also we still have packets pending on receive queue and probably,
3079 	 * our own packets waiting in device queues. sock_destroy will drain
3080 	 * receive queue, but transmitted packets will delay socket destruction
3081 	 * until the last reference will be released.
3082 	 */
3083 
3084 	sock_orphan(sk);
3085 
3086 	xfrm_sk_free_policy(sk);
3087 
3088 	sk_refcnt_debug_release(sk);
3089 
3090 	sock_put(sk);
3091 }
3092 EXPORT_SYMBOL(sk_common_release);
3093 
3094 void sk_get_meminfo(const struct sock *sk, u32 *mem)
3095 {
3096 	memset(mem, 0, sizeof(*mem) * SK_MEMINFO_VARS);
3097 
3098 	mem[SK_MEMINFO_RMEM_ALLOC] = sk_rmem_alloc_get(sk);
3099 	mem[SK_MEMINFO_RCVBUF] = sk->sk_rcvbuf;
3100 	mem[SK_MEMINFO_WMEM_ALLOC] = sk_wmem_alloc_get(sk);
3101 	mem[SK_MEMINFO_SNDBUF] = sk->sk_sndbuf;
3102 	mem[SK_MEMINFO_FWD_ALLOC] = sk->sk_forward_alloc;
3103 	mem[SK_MEMINFO_WMEM_QUEUED] = sk->sk_wmem_queued;
3104 	mem[SK_MEMINFO_OPTMEM] = atomic_read(&sk->sk_omem_alloc);
3105 	mem[SK_MEMINFO_BACKLOG] = sk->sk_backlog.len;
3106 	mem[SK_MEMINFO_DROPS] = atomic_read(&sk->sk_drops);
3107 }
3108 
3109 #ifdef CONFIG_PROC_FS
3110 #define PROTO_INUSE_NR	64	/* should be enough for the first time */
3111 struct prot_inuse {
3112 	int val[PROTO_INUSE_NR];
3113 };
3114 
3115 static DECLARE_BITMAP(proto_inuse_idx, PROTO_INUSE_NR);
3116 
3117 void sock_prot_inuse_add(struct net *net, struct proto *prot, int val)
3118 {
3119 	__this_cpu_add(net->core.prot_inuse->val[prot->inuse_idx], val);
3120 }
3121 EXPORT_SYMBOL_GPL(sock_prot_inuse_add);
3122 
3123 int sock_prot_inuse_get(struct net *net, struct proto *prot)
3124 {
3125 	int cpu, idx = prot->inuse_idx;
3126 	int res = 0;
3127 
3128 	for_each_possible_cpu(cpu)
3129 		res += per_cpu_ptr(net->core.prot_inuse, cpu)->val[idx];
3130 
3131 	return res >= 0 ? res : 0;
3132 }
3133 EXPORT_SYMBOL_GPL(sock_prot_inuse_get);
3134 
3135 static void sock_inuse_add(struct net *net, int val)
3136 {
3137 	this_cpu_add(*net->core.sock_inuse, val);
3138 }
3139 
3140 int sock_inuse_get(struct net *net)
3141 {
3142 	int cpu, res = 0;
3143 
3144 	for_each_possible_cpu(cpu)
3145 		res += *per_cpu_ptr(net->core.sock_inuse, cpu);
3146 
3147 	return res;
3148 }
3149 
3150 EXPORT_SYMBOL_GPL(sock_inuse_get);
3151 
3152 static int __net_init sock_inuse_init_net(struct net *net)
3153 {
3154 	net->core.prot_inuse = alloc_percpu(struct prot_inuse);
3155 	if (net->core.prot_inuse == NULL)
3156 		return -ENOMEM;
3157 
3158 	net->core.sock_inuse = alloc_percpu(int);
3159 	if (net->core.sock_inuse == NULL)
3160 		goto out;
3161 
3162 	return 0;
3163 
3164 out:
3165 	free_percpu(net->core.prot_inuse);
3166 	return -ENOMEM;
3167 }
3168 
3169 static void __net_exit sock_inuse_exit_net(struct net *net)
3170 {
3171 	free_percpu(net->core.prot_inuse);
3172 	free_percpu(net->core.sock_inuse);
3173 }
3174 
3175 static struct pernet_operations net_inuse_ops = {
3176 	.init = sock_inuse_init_net,
3177 	.exit = sock_inuse_exit_net,
3178 };
3179 
3180 static __init int net_inuse_init(void)
3181 {
3182 	if (register_pernet_subsys(&net_inuse_ops))
3183 		panic("Cannot initialize net inuse counters");
3184 
3185 	return 0;
3186 }
3187 
3188 core_initcall(net_inuse_init);
3189 
3190 static void assign_proto_idx(struct proto *prot)
3191 {
3192 	prot->inuse_idx = find_first_zero_bit(proto_inuse_idx, PROTO_INUSE_NR);
3193 
3194 	if (unlikely(prot->inuse_idx == PROTO_INUSE_NR - 1)) {
3195 		pr_err("PROTO_INUSE_NR exhausted\n");
3196 		return;
3197 	}
3198 
3199 	set_bit(prot->inuse_idx, proto_inuse_idx);
3200 }
3201 
3202 static void release_proto_idx(struct proto *prot)
3203 {
3204 	if (prot->inuse_idx != PROTO_INUSE_NR - 1)
3205 		clear_bit(prot->inuse_idx, proto_inuse_idx);
3206 }
3207 #else
3208 static inline void assign_proto_idx(struct proto *prot)
3209 {
3210 }
3211 
3212 static inline void release_proto_idx(struct proto *prot)
3213 {
3214 }
3215 
3216 static void sock_inuse_add(struct net *net, int val)
3217 {
3218 }
3219 #endif
3220 
3221 static void req_prot_cleanup(struct request_sock_ops *rsk_prot)
3222 {
3223 	if (!rsk_prot)
3224 		return;
3225 	kfree(rsk_prot->slab_name);
3226 	rsk_prot->slab_name = NULL;
3227 	kmem_cache_destroy(rsk_prot->slab);
3228 	rsk_prot->slab = NULL;
3229 }
3230 
3231 static int req_prot_init(const struct proto *prot)
3232 {
3233 	struct request_sock_ops *rsk_prot = prot->rsk_prot;
3234 
3235 	if (!rsk_prot)
3236 		return 0;
3237 
3238 	rsk_prot->slab_name = kasprintf(GFP_KERNEL, "request_sock_%s",
3239 					prot->name);
3240 	if (!rsk_prot->slab_name)
3241 		return -ENOMEM;
3242 
3243 	rsk_prot->slab = kmem_cache_create(rsk_prot->slab_name,
3244 					   rsk_prot->obj_size, 0,
3245 					   SLAB_ACCOUNT | prot->slab_flags,
3246 					   NULL);
3247 
3248 	if (!rsk_prot->slab) {
3249 		pr_crit("%s: Can't create request sock SLAB cache!\n",
3250 			prot->name);
3251 		return -ENOMEM;
3252 	}
3253 	return 0;
3254 }
3255 
3256 int proto_register(struct proto *prot, int alloc_slab)
3257 {
3258 	if (alloc_slab) {
3259 		prot->slab = kmem_cache_create_usercopy(prot->name,
3260 					prot->obj_size, 0,
3261 					SLAB_HWCACHE_ALIGN | SLAB_ACCOUNT |
3262 					prot->slab_flags,
3263 					prot->useroffset, prot->usersize,
3264 					NULL);
3265 
3266 		if (prot->slab == NULL) {
3267 			pr_crit("%s: Can't create sock SLAB cache!\n",
3268 				prot->name);
3269 			goto out;
3270 		}
3271 
3272 		if (req_prot_init(prot))
3273 			goto out_free_request_sock_slab;
3274 
3275 		if (prot->twsk_prot != NULL) {
3276 			prot->twsk_prot->twsk_slab_name = kasprintf(GFP_KERNEL, "tw_sock_%s", prot->name);
3277 
3278 			if (prot->twsk_prot->twsk_slab_name == NULL)
3279 				goto out_free_request_sock_slab;
3280 
3281 			prot->twsk_prot->twsk_slab =
3282 				kmem_cache_create(prot->twsk_prot->twsk_slab_name,
3283 						  prot->twsk_prot->twsk_obj_size,
3284 						  0,
3285 						  SLAB_ACCOUNT |
3286 						  prot->slab_flags,
3287 						  NULL);
3288 			if (prot->twsk_prot->twsk_slab == NULL)
3289 				goto out_free_timewait_sock_slab_name;
3290 		}
3291 	}
3292 
3293 	mutex_lock(&proto_list_mutex);
3294 	list_add(&prot->node, &proto_list);
3295 	assign_proto_idx(prot);
3296 	mutex_unlock(&proto_list_mutex);
3297 	return 0;
3298 
3299 out_free_timewait_sock_slab_name:
3300 	kfree(prot->twsk_prot->twsk_slab_name);
3301 out_free_request_sock_slab:
3302 	req_prot_cleanup(prot->rsk_prot);
3303 
3304 	kmem_cache_destroy(prot->slab);
3305 	prot->slab = NULL;
3306 out:
3307 	return -ENOBUFS;
3308 }
3309 EXPORT_SYMBOL(proto_register);
3310 
3311 void proto_unregister(struct proto *prot)
3312 {
3313 	mutex_lock(&proto_list_mutex);
3314 	release_proto_idx(prot);
3315 	list_del(&prot->node);
3316 	mutex_unlock(&proto_list_mutex);
3317 
3318 	kmem_cache_destroy(prot->slab);
3319 	prot->slab = NULL;
3320 
3321 	req_prot_cleanup(prot->rsk_prot);
3322 
3323 	if (prot->twsk_prot != NULL && prot->twsk_prot->twsk_slab != NULL) {
3324 		kmem_cache_destroy(prot->twsk_prot->twsk_slab);
3325 		kfree(prot->twsk_prot->twsk_slab_name);
3326 		prot->twsk_prot->twsk_slab = NULL;
3327 	}
3328 }
3329 EXPORT_SYMBOL(proto_unregister);
3330 
3331 int sock_load_diag_module(int family, int protocol)
3332 {
3333 	if (!protocol) {
3334 		if (!sock_is_registered(family))
3335 			return -ENOENT;
3336 
3337 		return request_module("net-pf-%d-proto-%d-type-%d", PF_NETLINK,
3338 				      NETLINK_SOCK_DIAG, family);
3339 	}
3340 
3341 #ifdef CONFIG_INET
3342 	if (family == AF_INET &&
3343 	    !rcu_access_pointer(inet_protos[protocol]))
3344 		return -ENOENT;
3345 #endif
3346 
3347 	return request_module("net-pf-%d-proto-%d-type-%d-%d", PF_NETLINK,
3348 			      NETLINK_SOCK_DIAG, family, protocol);
3349 }
3350 EXPORT_SYMBOL(sock_load_diag_module);
3351 
3352 #ifdef CONFIG_PROC_FS
3353 static void *proto_seq_start(struct seq_file *seq, loff_t *pos)
3354 	__acquires(proto_list_mutex)
3355 {
3356 	mutex_lock(&proto_list_mutex);
3357 	return seq_list_start_head(&proto_list, *pos);
3358 }
3359 
3360 static void *proto_seq_next(struct seq_file *seq, void *v, loff_t *pos)
3361 {
3362 	return seq_list_next(v, &proto_list, pos);
3363 }
3364 
3365 static void proto_seq_stop(struct seq_file *seq, void *v)
3366 	__releases(proto_list_mutex)
3367 {
3368 	mutex_unlock(&proto_list_mutex);
3369 }
3370 
3371 static char proto_method_implemented(const void *method)
3372 {
3373 	return method == NULL ? 'n' : 'y';
3374 }
3375 static long sock_prot_memory_allocated(struct proto *proto)
3376 {
3377 	return proto->memory_allocated != NULL ? proto_memory_allocated(proto) : -1L;
3378 }
3379 
3380 static char *sock_prot_memory_pressure(struct proto *proto)
3381 {
3382 	return proto->memory_pressure != NULL ?
3383 	proto_memory_pressure(proto) ? "yes" : "no" : "NI";
3384 }
3385 
3386 static void proto_seq_printf(struct seq_file *seq, struct proto *proto)
3387 {
3388 
3389 	seq_printf(seq, "%-9s %4u %6d  %6ld   %-3s %6u   %-3s  %-10s "
3390 			"%2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c\n",
3391 		   proto->name,
3392 		   proto->obj_size,
3393 		   sock_prot_inuse_get(seq_file_net(seq), proto),
3394 		   sock_prot_memory_allocated(proto),
3395 		   sock_prot_memory_pressure(proto),
3396 		   proto->max_header,
3397 		   proto->slab == NULL ? "no" : "yes",
3398 		   module_name(proto->owner),
3399 		   proto_method_implemented(proto->close),
3400 		   proto_method_implemented(proto->connect),
3401 		   proto_method_implemented(proto->disconnect),
3402 		   proto_method_implemented(proto->accept),
3403 		   proto_method_implemented(proto->ioctl),
3404 		   proto_method_implemented(proto->init),
3405 		   proto_method_implemented(proto->destroy),
3406 		   proto_method_implemented(proto->shutdown),
3407 		   proto_method_implemented(proto->setsockopt),
3408 		   proto_method_implemented(proto->getsockopt),
3409 		   proto_method_implemented(proto->sendmsg),
3410 		   proto_method_implemented(proto->recvmsg),
3411 		   proto_method_implemented(proto->sendpage),
3412 		   proto_method_implemented(proto->bind),
3413 		   proto_method_implemented(proto->backlog_rcv),
3414 		   proto_method_implemented(proto->hash),
3415 		   proto_method_implemented(proto->unhash),
3416 		   proto_method_implemented(proto->get_port),
3417 		   proto_method_implemented(proto->enter_memory_pressure));
3418 }
3419 
3420 static int proto_seq_show(struct seq_file *seq, void *v)
3421 {
3422 	if (v == &proto_list)
3423 		seq_printf(seq, "%-9s %-4s %-8s %-6s %-5s %-7s %-4s %-10s %s",
3424 			   "protocol",
3425 			   "size",
3426 			   "sockets",
3427 			   "memory",
3428 			   "press",
3429 			   "maxhdr",
3430 			   "slab",
3431 			   "module",
3432 			   "cl co di ac io in de sh ss gs se re sp bi br ha uh gp em\n");
3433 	else
3434 		proto_seq_printf(seq, list_entry(v, struct proto, node));
3435 	return 0;
3436 }
3437 
3438 static const struct seq_operations proto_seq_ops = {
3439 	.start  = proto_seq_start,
3440 	.next   = proto_seq_next,
3441 	.stop   = proto_seq_stop,
3442 	.show   = proto_seq_show,
3443 };
3444 
3445 static __net_init int proto_init_net(struct net *net)
3446 {
3447 	if (!proc_create_net("protocols", 0444, net->proc_net, &proto_seq_ops,
3448 			sizeof(struct seq_net_private)))
3449 		return -ENOMEM;
3450 
3451 	return 0;
3452 }
3453 
3454 static __net_exit void proto_exit_net(struct net *net)
3455 {
3456 	remove_proc_entry("protocols", net->proc_net);
3457 }
3458 
3459 
3460 static __net_initdata struct pernet_operations proto_net_ops = {
3461 	.init = proto_init_net,
3462 	.exit = proto_exit_net,
3463 };
3464 
3465 static int __init proto_init(void)
3466 {
3467 	return register_pernet_subsys(&proto_net_ops);
3468 }
3469 
3470 subsys_initcall(proto_init);
3471 
3472 #endif /* PROC_FS */
3473 
3474 #ifdef CONFIG_NET_RX_BUSY_POLL
3475 bool sk_busy_loop_end(void *p, unsigned long start_time)
3476 {
3477 	struct sock *sk = p;
3478 
3479 	return !skb_queue_empty(&sk->sk_receive_queue) ||
3480 	       sk_busy_loop_timeout(sk, start_time);
3481 }
3482 EXPORT_SYMBOL(sk_busy_loop_end);
3483 #endif /* CONFIG_NET_RX_BUSY_POLL */
3484