xref: /linux/net/core/sock.c (revision 95f28190aa012b18eab14799b905b6db3cf31529)
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 <linux/capability.h>
95 #include <linux/errno.h>
96 #include <linux/errqueue.h>
97 #include <linux/types.h>
98 #include <linux/socket.h>
99 #include <linux/in.h>
100 #include <linux/kernel.h>
101 #include <linux/module.h>
102 #include <linux/proc_fs.h>
103 #include <linux/seq_file.h>
104 #include <linux/sched.h>
105 #include <linux/sched/mm.h>
106 #include <linux/timer.h>
107 #include <linux/string.h>
108 #include <linux/sockios.h>
109 #include <linux/net.h>
110 #include <linux/mm.h>
111 #include <linux/slab.h>
112 #include <linux/interrupt.h>
113 #include <linux/poll.h>
114 #include <linux/tcp.h>
115 #include <linux/init.h>
116 #include <linux/highmem.h>
117 #include <linux/user_namespace.h>
118 #include <linux/static_key.h>
119 #include <linux/memcontrol.h>
120 #include <linux/prefetch.h>
121 
122 #include <linux/uaccess.h>
123 
124 #include <linux/netdevice.h>
125 #include <net/protocol.h>
126 #include <linux/skbuff.h>
127 #include <net/net_namespace.h>
128 #include <net/request_sock.h>
129 #include <net/sock.h>
130 #include <linux/net_tstamp.h>
131 #include <net/xfrm.h>
132 #include <linux/ipsec.h>
133 #include <net/cls_cgroup.h>
134 #include <net/netprio_cgroup.h>
135 #include <linux/sock_diag.h>
136 
137 #include <linux/filter.h>
138 #include <net/sock_reuseport.h>
139 
140 #include <trace/events/sock.h>
141 
142 #include <net/tcp.h>
143 #include <net/busy_poll.h>
144 
145 static DEFINE_MUTEX(proto_list_mutex);
146 static LIST_HEAD(proto_list);
147 
148 /**
149  * sk_ns_capable - General socket capability test
150  * @sk: Socket to use a capability on or through
151  * @user_ns: The user namespace of the capability to use
152  * @cap: The capability to use
153  *
154  * Test to see if the opener of the socket had when the socket was
155  * created and the current process has the capability @cap in the user
156  * namespace @user_ns.
157  */
158 bool sk_ns_capable(const struct sock *sk,
159 		   struct user_namespace *user_ns, int cap)
160 {
161 	return file_ns_capable(sk->sk_socket->file, user_ns, cap) &&
162 		ns_capable(user_ns, cap);
163 }
164 EXPORT_SYMBOL(sk_ns_capable);
165 
166 /**
167  * sk_capable - Socket global capability test
168  * @sk: Socket to use a capability on or through
169  * @cap: The global capability to use
170  *
171  * Test to see if the opener of the socket had when the socket was
172  * created and the current process has the capability @cap in all user
173  * namespaces.
174  */
175 bool sk_capable(const struct sock *sk, int cap)
176 {
177 	return sk_ns_capable(sk, &init_user_ns, cap);
178 }
179 EXPORT_SYMBOL(sk_capable);
180 
181 /**
182  * sk_net_capable - Network namespace socket capability test
183  * @sk: Socket to use a capability on or through
184  * @cap: The capability to use
185  *
186  * Test to see if the opener of the socket had when the socket was created
187  * and the current process has the capability @cap over the network namespace
188  * the socket is a member of.
189  */
190 bool sk_net_capable(const struct sock *sk, int cap)
191 {
192 	return sk_ns_capable(sk, sock_net(sk)->user_ns, cap);
193 }
194 EXPORT_SYMBOL(sk_net_capable);
195 
196 /*
197  * Each address family might have different locking rules, so we have
198  * one slock key per address family and separate keys for internal and
199  * userspace sockets.
200  */
201 static struct lock_class_key af_family_keys[AF_MAX];
202 static struct lock_class_key af_family_kern_keys[AF_MAX];
203 static struct lock_class_key af_family_slock_keys[AF_MAX];
204 static struct lock_class_key af_family_kern_slock_keys[AF_MAX];
205 
206 /*
207  * Make lock validator output more readable. (we pre-construct these
208  * strings build-time, so that runtime initialization of socket
209  * locks is fast):
210  */
211 
212 #define _sock_locks(x)						  \
213   x "AF_UNSPEC",	x "AF_UNIX"     ,	x "AF_INET"     , \
214   x "AF_AX25"  ,	x "AF_IPX"      ,	x "AF_APPLETALK", \
215   x "AF_NETROM",	x "AF_BRIDGE"   ,	x "AF_ATMPVC"   , \
216   x "AF_X25"   ,	x "AF_INET6"    ,	x "AF_ROSE"     , \
217   x "AF_DECnet",	x "AF_NETBEUI"  ,	x "AF_SECURITY" , \
218   x "AF_KEY"   ,	x "AF_NETLINK"  ,	x "AF_PACKET"   , \
219   x "AF_ASH"   ,	x "AF_ECONET"   ,	x "AF_ATMSVC"   , \
220   x "AF_RDS"   ,	x "AF_SNA"      ,	x "AF_IRDA"     , \
221   x "AF_PPPOX" ,	x "AF_WANPIPE"  ,	x "AF_LLC"      , \
222   x "27"       ,	x "28"          ,	x "AF_CAN"      , \
223   x "AF_TIPC"  ,	x "AF_BLUETOOTH",	x "IUCV"        , \
224   x "AF_RXRPC" ,	x "AF_ISDN"     ,	x "AF_PHONET"   , \
225   x "AF_IEEE802154",	x "AF_CAIF"	,	x "AF_ALG"      , \
226   x "AF_NFC"   ,	x "AF_VSOCK"    ,	x "AF_KCM"      , \
227   x "AF_QIPCRTR",	x "AF_SMC"	,	x "AF_MAX"
228 
229 static const char *const af_family_key_strings[AF_MAX+1] = {
230 	_sock_locks("sk_lock-")
231 };
232 static const char *const af_family_slock_key_strings[AF_MAX+1] = {
233 	_sock_locks("slock-")
234 };
235 static const char *const af_family_clock_key_strings[AF_MAX+1] = {
236 	_sock_locks("clock-")
237 };
238 
239 static const char *const af_family_kern_key_strings[AF_MAX+1] = {
240 	_sock_locks("k-sk_lock-")
241 };
242 static const char *const af_family_kern_slock_key_strings[AF_MAX+1] = {
243 	_sock_locks("k-slock-")
244 };
245 static const char *const af_family_kern_clock_key_strings[AF_MAX+1] = {
246 	_sock_locks("k-clock-")
247 };
248 static const char *const af_family_rlock_key_strings[AF_MAX+1] = {
249   "rlock-AF_UNSPEC", "rlock-AF_UNIX"     , "rlock-AF_INET"     ,
250   "rlock-AF_AX25"  , "rlock-AF_IPX"      , "rlock-AF_APPLETALK",
251   "rlock-AF_NETROM", "rlock-AF_BRIDGE"   , "rlock-AF_ATMPVC"   ,
252   "rlock-AF_X25"   , "rlock-AF_INET6"    , "rlock-AF_ROSE"     ,
253   "rlock-AF_DECnet", "rlock-AF_NETBEUI"  , "rlock-AF_SECURITY" ,
254   "rlock-AF_KEY"   , "rlock-AF_NETLINK"  , "rlock-AF_PACKET"   ,
255   "rlock-AF_ASH"   , "rlock-AF_ECONET"   , "rlock-AF_ATMSVC"   ,
256   "rlock-AF_RDS"   , "rlock-AF_SNA"      , "rlock-AF_IRDA"     ,
257   "rlock-AF_PPPOX" , "rlock-AF_WANPIPE"  , "rlock-AF_LLC"      ,
258   "rlock-27"       , "rlock-28"          , "rlock-AF_CAN"      ,
259   "rlock-AF_TIPC"  , "rlock-AF_BLUETOOTH", "rlock-AF_IUCV"     ,
260   "rlock-AF_RXRPC" , "rlock-AF_ISDN"     , "rlock-AF_PHONET"   ,
261   "rlock-AF_IEEE802154", "rlock-AF_CAIF" , "rlock-AF_ALG"      ,
262   "rlock-AF_NFC"   , "rlock-AF_VSOCK"    , "rlock-AF_KCM"      ,
263   "rlock-AF_QIPCRTR", "rlock-AF_SMC"     , "rlock-AF_MAX"
264 };
265 static const char *const af_family_wlock_key_strings[AF_MAX+1] = {
266   "wlock-AF_UNSPEC", "wlock-AF_UNIX"     , "wlock-AF_INET"     ,
267   "wlock-AF_AX25"  , "wlock-AF_IPX"      , "wlock-AF_APPLETALK",
268   "wlock-AF_NETROM", "wlock-AF_BRIDGE"   , "wlock-AF_ATMPVC"   ,
269   "wlock-AF_X25"   , "wlock-AF_INET6"    , "wlock-AF_ROSE"     ,
270   "wlock-AF_DECnet", "wlock-AF_NETBEUI"  , "wlock-AF_SECURITY" ,
271   "wlock-AF_KEY"   , "wlock-AF_NETLINK"  , "wlock-AF_PACKET"   ,
272   "wlock-AF_ASH"   , "wlock-AF_ECONET"   , "wlock-AF_ATMSVC"   ,
273   "wlock-AF_RDS"   , "wlock-AF_SNA"      , "wlock-AF_IRDA"     ,
274   "wlock-AF_PPPOX" , "wlock-AF_WANPIPE"  , "wlock-AF_LLC"      ,
275   "wlock-27"       , "wlock-28"          , "wlock-AF_CAN"      ,
276   "wlock-AF_TIPC"  , "wlock-AF_BLUETOOTH", "wlock-AF_IUCV"     ,
277   "wlock-AF_RXRPC" , "wlock-AF_ISDN"     , "wlock-AF_PHONET"   ,
278   "wlock-AF_IEEE802154", "wlock-AF_CAIF" , "wlock-AF_ALG"      ,
279   "wlock-AF_NFC"   , "wlock-AF_VSOCK"    , "wlock-AF_KCM"      ,
280   "wlock-AF_QIPCRTR", "wlock-AF_SMC"     , "wlock-AF_MAX"
281 };
282 static const char *const af_family_elock_key_strings[AF_MAX+1] = {
283   "elock-AF_UNSPEC", "elock-AF_UNIX"     , "elock-AF_INET"     ,
284   "elock-AF_AX25"  , "elock-AF_IPX"      , "elock-AF_APPLETALK",
285   "elock-AF_NETROM", "elock-AF_BRIDGE"   , "elock-AF_ATMPVC"   ,
286   "elock-AF_X25"   , "elock-AF_INET6"    , "elock-AF_ROSE"     ,
287   "elock-AF_DECnet", "elock-AF_NETBEUI"  , "elock-AF_SECURITY" ,
288   "elock-AF_KEY"   , "elock-AF_NETLINK"  , "elock-AF_PACKET"   ,
289   "elock-AF_ASH"   , "elock-AF_ECONET"   , "elock-AF_ATMSVC"   ,
290   "elock-AF_RDS"   , "elock-AF_SNA"      , "elock-AF_IRDA"     ,
291   "elock-AF_PPPOX" , "elock-AF_WANPIPE"  , "elock-AF_LLC"      ,
292   "elock-27"       , "elock-28"          , "elock-AF_CAN"      ,
293   "elock-AF_TIPC"  , "elock-AF_BLUETOOTH", "elock-AF_IUCV"     ,
294   "elock-AF_RXRPC" , "elock-AF_ISDN"     , "elock-AF_PHONET"   ,
295   "elock-AF_IEEE802154", "elock-AF_CAIF" , "elock-AF_ALG"      ,
296   "elock-AF_NFC"   , "elock-AF_VSOCK"    , "elock-AF_KCM"      ,
297   "elock-AF_QIPCRTR", "elock-AF_SMC"     , "elock-AF_MAX"
298 };
299 
300 /*
301  * sk_callback_lock and sk queues locking rules are per-address-family,
302  * so split the lock classes by using a per-AF key:
303  */
304 static struct lock_class_key af_callback_keys[AF_MAX];
305 static struct lock_class_key af_rlock_keys[AF_MAX];
306 static struct lock_class_key af_wlock_keys[AF_MAX];
307 static struct lock_class_key af_elock_keys[AF_MAX];
308 static struct lock_class_key af_kern_callback_keys[AF_MAX];
309 
310 /* Run time adjustable parameters. */
311 __u32 sysctl_wmem_max __read_mostly = SK_WMEM_MAX;
312 EXPORT_SYMBOL(sysctl_wmem_max);
313 __u32 sysctl_rmem_max __read_mostly = SK_RMEM_MAX;
314 EXPORT_SYMBOL(sysctl_rmem_max);
315 __u32 sysctl_wmem_default __read_mostly = SK_WMEM_MAX;
316 __u32 sysctl_rmem_default __read_mostly = SK_RMEM_MAX;
317 
318 /* Maximal space eaten by iovec or ancillary data plus some space */
319 int sysctl_optmem_max __read_mostly = sizeof(unsigned long)*(2*UIO_MAXIOV+512);
320 EXPORT_SYMBOL(sysctl_optmem_max);
321 
322 int sysctl_tstamp_allow_data __read_mostly = 1;
323 
324 struct static_key memalloc_socks = STATIC_KEY_INIT_FALSE;
325 EXPORT_SYMBOL_GPL(memalloc_socks);
326 
327 /**
328  * sk_set_memalloc - sets %SOCK_MEMALLOC
329  * @sk: socket to set it on
330  *
331  * Set %SOCK_MEMALLOC on a socket for access to emergency reserves.
332  * It's the responsibility of the admin to adjust min_free_kbytes
333  * to meet the requirements
334  */
335 void sk_set_memalloc(struct sock *sk)
336 {
337 	sock_set_flag(sk, SOCK_MEMALLOC);
338 	sk->sk_allocation |= __GFP_MEMALLOC;
339 	static_key_slow_inc(&memalloc_socks);
340 }
341 EXPORT_SYMBOL_GPL(sk_set_memalloc);
342 
343 void sk_clear_memalloc(struct sock *sk)
344 {
345 	sock_reset_flag(sk, SOCK_MEMALLOC);
346 	sk->sk_allocation &= ~__GFP_MEMALLOC;
347 	static_key_slow_dec(&memalloc_socks);
348 
349 	/*
350 	 * SOCK_MEMALLOC is allowed to ignore rmem limits to ensure forward
351 	 * progress of swapping. SOCK_MEMALLOC may be cleared while
352 	 * it has rmem allocations due to the last swapfile being deactivated
353 	 * but there is a risk that the socket is unusable due to exceeding
354 	 * the rmem limits. Reclaim the reserves and obey rmem limits again.
355 	 */
356 	sk_mem_reclaim(sk);
357 }
358 EXPORT_SYMBOL_GPL(sk_clear_memalloc);
359 
360 int __sk_backlog_rcv(struct sock *sk, struct sk_buff *skb)
361 {
362 	int ret;
363 	unsigned int noreclaim_flag;
364 
365 	/* these should have been dropped before queueing */
366 	BUG_ON(!sock_flag(sk, SOCK_MEMALLOC));
367 
368 	noreclaim_flag = memalloc_noreclaim_save();
369 	ret = sk->sk_backlog_rcv(sk, skb);
370 	memalloc_noreclaim_restore(noreclaim_flag);
371 
372 	return ret;
373 }
374 EXPORT_SYMBOL(__sk_backlog_rcv);
375 
376 static int sock_set_timeout(long *timeo_p, char __user *optval, int optlen)
377 {
378 	struct timeval tv;
379 
380 	if (optlen < sizeof(tv))
381 		return -EINVAL;
382 	if (copy_from_user(&tv, optval, sizeof(tv)))
383 		return -EFAULT;
384 	if (tv.tv_usec < 0 || tv.tv_usec >= USEC_PER_SEC)
385 		return -EDOM;
386 
387 	if (tv.tv_sec < 0) {
388 		static int warned __read_mostly;
389 
390 		*timeo_p = 0;
391 		if (warned < 10 && net_ratelimit()) {
392 			warned++;
393 			pr_info("%s: `%s' (pid %d) tries to set negative timeout\n",
394 				__func__, current->comm, task_pid_nr(current));
395 		}
396 		return 0;
397 	}
398 	*timeo_p = MAX_SCHEDULE_TIMEOUT;
399 	if (tv.tv_sec == 0 && tv.tv_usec == 0)
400 		return 0;
401 	if (tv.tv_sec < (MAX_SCHEDULE_TIMEOUT/HZ - 1))
402 		*timeo_p = tv.tv_sec * HZ + DIV_ROUND_UP(tv.tv_usec, USEC_PER_SEC / HZ);
403 	return 0;
404 }
405 
406 static void sock_warn_obsolete_bsdism(const char *name)
407 {
408 	static int warned;
409 	static char warncomm[TASK_COMM_LEN];
410 	if (strcmp(warncomm, current->comm) && warned < 5) {
411 		strcpy(warncomm,  current->comm);
412 		pr_warn("process `%s' is using obsolete %s SO_BSDCOMPAT\n",
413 			warncomm, name);
414 		warned++;
415 	}
416 }
417 
418 static bool sock_needs_netstamp(const struct sock *sk)
419 {
420 	switch (sk->sk_family) {
421 	case AF_UNSPEC:
422 	case AF_UNIX:
423 		return false;
424 	default:
425 		return true;
426 	}
427 }
428 
429 static void sock_disable_timestamp(struct sock *sk, unsigned long flags)
430 {
431 	if (sk->sk_flags & flags) {
432 		sk->sk_flags &= ~flags;
433 		if (sock_needs_netstamp(sk) &&
434 		    !(sk->sk_flags & SK_FLAGS_TIMESTAMP))
435 			net_disable_timestamp();
436 	}
437 }
438 
439 
440 int __sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
441 {
442 	unsigned long flags;
443 	struct sk_buff_head *list = &sk->sk_receive_queue;
444 
445 	if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf) {
446 		atomic_inc(&sk->sk_drops);
447 		trace_sock_rcvqueue_full(sk, skb);
448 		return -ENOMEM;
449 	}
450 
451 	if (!sk_rmem_schedule(sk, skb, skb->truesize)) {
452 		atomic_inc(&sk->sk_drops);
453 		return -ENOBUFS;
454 	}
455 
456 	skb->dev = NULL;
457 	skb_set_owner_r(skb, sk);
458 
459 	/* we escape from rcu protected region, make sure we dont leak
460 	 * a norefcounted dst
461 	 */
462 	skb_dst_force(skb);
463 
464 	spin_lock_irqsave(&list->lock, flags);
465 	sock_skb_set_dropcount(sk, skb);
466 	__skb_queue_tail(list, skb);
467 	spin_unlock_irqrestore(&list->lock, flags);
468 
469 	if (!sock_flag(sk, SOCK_DEAD))
470 		sk->sk_data_ready(sk);
471 	return 0;
472 }
473 EXPORT_SYMBOL(__sock_queue_rcv_skb);
474 
475 int sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
476 {
477 	int err;
478 
479 	err = sk_filter(sk, skb);
480 	if (err)
481 		return err;
482 
483 	return __sock_queue_rcv_skb(sk, skb);
484 }
485 EXPORT_SYMBOL(sock_queue_rcv_skb);
486 
487 int __sk_receive_skb(struct sock *sk, struct sk_buff *skb,
488 		     const int nested, unsigned int trim_cap, bool refcounted)
489 {
490 	int rc = NET_RX_SUCCESS;
491 
492 	if (sk_filter_trim_cap(sk, skb, trim_cap))
493 		goto discard_and_relse;
494 
495 	skb->dev = NULL;
496 
497 	if (sk_rcvqueues_full(sk, sk->sk_rcvbuf)) {
498 		atomic_inc(&sk->sk_drops);
499 		goto discard_and_relse;
500 	}
501 	if (nested)
502 		bh_lock_sock_nested(sk);
503 	else
504 		bh_lock_sock(sk);
505 	if (!sock_owned_by_user(sk)) {
506 		/*
507 		 * trylock + unlock semantics:
508 		 */
509 		mutex_acquire(&sk->sk_lock.dep_map, 0, 1, _RET_IP_);
510 
511 		rc = sk_backlog_rcv(sk, skb);
512 
513 		mutex_release(&sk->sk_lock.dep_map, 1, _RET_IP_);
514 	} else if (sk_add_backlog(sk, skb, sk->sk_rcvbuf)) {
515 		bh_unlock_sock(sk);
516 		atomic_inc(&sk->sk_drops);
517 		goto discard_and_relse;
518 	}
519 
520 	bh_unlock_sock(sk);
521 out:
522 	if (refcounted)
523 		sock_put(sk);
524 	return rc;
525 discard_and_relse:
526 	kfree_skb(skb);
527 	goto out;
528 }
529 EXPORT_SYMBOL(__sk_receive_skb);
530 
531 struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie)
532 {
533 	struct dst_entry *dst = __sk_dst_get(sk);
534 
535 	if (dst && dst->obsolete && dst->ops->check(dst, cookie) == NULL) {
536 		sk_tx_queue_clear(sk);
537 		sk->sk_dst_pending_confirm = 0;
538 		RCU_INIT_POINTER(sk->sk_dst_cache, NULL);
539 		dst_release(dst);
540 		return NULL;
541 	}
542 
543 	return dst;
544 }
545 EXPORT_SYMBOL(__sk_dst_check);
546 
547 struct dst_entry *sk_dst_check(struct sock *sk, u32 cookie)
548 {
549 	struct dst_entry *dst = sk_dst_get(sk);
550 
551 	if (dst && dst->obsolete && dst->ops->check(dst, cookie) == NULL) {
552 		sk_dst_reset(sk);
553 		dst_release(dst);
554 		return NULL;
555 	}
556 
557 	return dst;
558 }
559 EXPORT_SYMBOL(sk_dst_check);
560 
561 static int sock_setbindtodevice(struct sock *sk, char __user *optval,
562 				int optlen)
563 {
564 	int ret = -ENOPROTOOPT;
565 #ifdef CONFIG_NETDEVICES
566 	struct net *net = sock_net(sk);
567 	char devname[IFNAMSIZ];
568 	int index;
569 
570 	/* Sorry... */
571 	ret = -EPERM;
572 	if (!ns_capable(net->user_ns, CAP_NET_RAW))
573 		goto out;
574 
575 	ret = -EINVAL;
576 	if (optlen < 0)
577 		goto out;
578 
579 	/* Bind this socket to a particular device like "eth0",
580 	 * as specified in the passed interface name. If the
581 	 * name is "" or the option length is zero the socket
582 	 * is not bound.
583 	 */
584 	if (optlen > IFNAMSIZ - 1)
585 		optlen = IFNAMSIZ - 1;
586 	memset(devname, 0, sizeof(devname));
587 
588 	ret = -EFAULT;
589 	if (copy_from_user(devname, optval, optlen))
590 		goto out;
591 
592 	index = 0;
593 	if (devname[0] != '\0') {
594 		struct net_device *dev;
595 
596 		rcu_read_lock();
597 		dev = dev_get_by_name_rcu(net, devname);
598 		if (dev)
599 			index = dev->ifindex;
600 		rcu_read_unlock();
601 		ret = -ENODEV;
602 		if (!dev)
603 			goto out;
604 	}
605 
606 	lock_sock(sk);
607 	sk->sk_bound_dev_if = index;
608 	sk_dst_reset(sk);
609 	release_sock(sk);
610 
611 	ret = 0;
612 
613 out:
614 #endif
615 
616 	return ret;
617 }
618 
619 static int sock_getbindtodevice(struct sock *sk, char __user *optval,
620 				int __user *optlen, int len)
621 {
622 	int ret = -ENOPROTOOPT;
623 #ifdef CONFIG_NETDEVICES
624 	struct net *net = sock_net(sk);
625 	char devname[IFNAMSIZ];
626 
627 	if (sk->sk_bound_dev_if == 0) {
628 		len = 0;
629 		goto zero;
630 	}
631 
632 	ret = -EINVAL;
633 	if (len < IFNAMSIZ)
634 		goto out;
635 
636 	ret = netdev_get_name(net, devname, sk->sk_bound_dev_if);
637 	if (ret)
638 		goto out;
639 
640 	len = strlen(devname) + 1;
641 
642 	ret = -EFAULT;
643 	if (copy_to_user(optval, devname, len))
644 		goto out;
645 
646 zero:
647 	ret = -EFAULT;
648 	if (put_user(len, optlen))
649 		goto out;
650 
651 	ret = 0;
652 
653 out:
654 #endif
655 
656 	return ret;
657 }
658 
659 static inline void sock_valbool_flag(struct sock *sk, int bit, int valbool)
660 {
661 	if (valbool)
662 		sock_set_flag(sk, bit);
663 	else
664 		sock_reset_flag(sk, bit);
665 }
666 
667 bool sk_mc_loop(struct sock *sk)
668 {
669 	if (dev_recursion_level())
670 		return false;
671 	if (!sk)
672 		return true;
673 	switch (sk->sk_family) {
674 	case AF_INET:
675 		return inet_sk(sk)->mc_loop;
676 #if IS_ENABLED(CONFIG_IPV6)
677 	case AF_INET6:
678 		return inet6_sk(sk)->mc_loop;
679 #endif
680 	}
681 	WARN_ON(1);
682 	return true;
683 }
684 EXPORT_SYMBOL(sk_mc_loop);
685 
686 /*
687  *	This is meant for all protocols to use and covers goings on
688  *	at the socket level. Everything here is generic.
689  */
690 
691 int sock_setsockopt(struct socket *sock, int level, int optname,
692 		    char __user *optval, unsigned int optlen)
693 {
694 	struct sock *sk = sock->sk;
695 	int val;
696 	int valbool;
697 	struct linger ling;
698 	int ret = 0;
699 
700 	/*
701 	 *	Options without arguments
702 	 */
703 
704 	if (optname == SO_BINDTODEVICE)
705 		return sock_setbindtodevice(sk, optval, optlen);
706 
707 	if (optlen < sizeof(int))
708 		return -EINVAL;
709 
710 	if (get_user(val, (int __user *)optval))
711 		return -EFAULT;
712 
713 	valbool = val ? 1 : 0;
714 
715 	lock_sock(sk);
716 
717 	switch (optname) {
718 	case SO_DEBUG:
719 		if (val && !capable(CAP_NET_ADMIN))
720 			ret = -EACCES;
721 		else
722 			sock_valbool_flag(sk, SOCK_DBG, valbool);
723 		break;
724 	case SO_REUSEADDR:
725 		sk->sk_reuse = (valbool ? SK_CAN_REUSE : SK_NO_REUSE);
726 		break;
727 	case SO_REUSEPORT:
728 		sk->sk_reuseport = valbool;
729 		break;
730 	case SO_TYPE:
731 	case SO_PROTOCOL:
732 	case SO_DOMAIN:
733 	case SO_ERROR:
734 		ret = -ENOPROTOOPT;
735 		break;
736 	case SO_DONTROUTE:
737 		sock_valbool_flag(sk, SOCK_LOCALROUTE, valbool);
738 		break;
739 	case SO_BROADCAST:
740 		sock_valbool_flag(sk, SOCK_BROADCAST, valbool);
741 		break;
742 	case SO_SNDBUF:
743 		/* Don't error on this BSD doesn't and if you think
744 		 * about it this is right. Otherwise apps have to
745 		 * play 'guess the biggest size' games. RCVBUF/SNDBUF
746 		 * are treated in BSD as hints
747 		 */
748 		val = min_t(u32, val, sysctl_wmem_max);
749 set_sndbuf:
750 		sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
751 		sk->sk_sndbuf = max_t(int, val * 2, SOCK_MIN_SNDBUF);
752 		/* Wake up sending tasks if we upped the value. */
753 		sk->sk_write_space(sk);
754 		break;
755 
756 	case SO_SNDBUFFORCE:
757 		if (!capable(CAP_NET_ADMIN)) {
758 			ret = -EPERM;
759 			break;
760 		}
761 		goto set_sndbuf;
762 
763 	case SO_RCVBUF:
764 		/* Don't error on this BSD doesn't and if you think
765 		 * about it this is right. Otherwise apps have to
766 		 * play 'guess the biggest size' games. RCVBUF/SNDBUF
767 		 * are treated in BSD as hints
768 		 */
769 		val = min_t(u32, val, sysctl_rmem_max);
770 set_rcvbuf:
771 		sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
772 		/*
773 		 * We double it on the way in to account for
774 		 * "struct sk_buff" etc. overhead.   Applications
775 		 * assume that the SO_RCVBUF setting they make will
776 		 * allow that much actual data to be received on that
777 		 * socket.
778 		 *
779 		 * Applications are unaware that "struct sk_buff" and
780 		 * other overheads allocate from the receive buffer
781 		 * during socket buffer allocation.
782 		 *
783 		 * And after considering the possible alternatives,
784 		 * returning the value we actually used in getsockopt
785 		 * is the most desirable behavior.
786 		 */
787 		sk->sk_rcvbuf = max_t(int, val * 2, SOCK_MIN_RCVBUF);
788 		break;
789 
790 	case SO_RCVBUFFORCE:
791 		if (!capable(CAP_NET_ADMIN)) {
792 			ret = -EPERM;
793 			break;
794 		}
795 		goto set_rcvbuf;
796 
797 	case SO_KEEPALIVE:
798 		if (sk->sk_prot->keepalive)
799 			sk->sk_prot->keepalive(sk, valbool);
800 		sock_valbool_flag(sk, SOCK_KEEPOPEN, valbool);
801 		break;
802 
803 	case SO_OOBINLINE:
804 		sock_valbool_flag(sk, SOCK_URGINLINE, valbool);
805 		break;
806 
807 	case SO_NO_CHECK:
808 		sk->sk_no_check_tx = valbool;
809 		break;
810 
811 	case SO_PRIORITY:
812 		if ((val >= 0 && val <= 6) ||
813 		    ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
814 			sk->sk_priority = val;
815 		else
816 			ret = -EPERM;
817 		break;
818 
819 	case SO_LINGER:
820 		if (optlen < sizeof(ling)) {
821 			ret = -EINVAL;	/* 1003.1g */
822 			break;
823 		}
824 		if (copy_from_user(&ling, optval, sizeof(ling))) {
825 			ret = -EFAULT;
826 			break;
827 		}
828 		if (!ling.l_onoff)
829 			sock_reset_flag(sk, SOCK_LINGER);
830 		else {
831 #if (BITS_PER_LONG == 32)
832 			if ((unsigned int)ling.l_linger >= MAX_SCHEDULE_TIMEOUT/HZ)
833 				sk->sk_lingertime = MAX_SCHEDULE_TIMEOUT;
834 			else
835 #endif
836 				sk->sk_lingertime = (unsigned int)ling.l_linger * HZ;
837 			sock_set_flag(sk, SOCK_LINGER);
838 		}
839 		break;
840 
841 	case SO_BSDCOMPAT:
842 		sock_warn_obsolete_bsdism("setsockopt");
843 		break;
844 
845 	case SO_PASSCRED:
846 		if (valbool)
847 			set_bit(SOCK_PASSCRED, &sock->flags);
848 		else
849 			clear_bit(SOCK_PASSCRED, &sock->flags);
850 		break;
851 
852 	case SO_TIMESTAMP:
853 	case SO_TIMESTAMPNS:
854 		if (valbool)  {
855 			if (optname == SO_TIMESTAMP)
856 				sock_reset_flag(sk, SOCK_RCVTSTAMPNS);
857 			else
858 				sock_set_flag(sk, SOCK_RCVTSTAMPNS);
859 			sock_set_flag(sk, SOCK_RCVTSTAMP);
860 			sock_enable_timestamp(sk, SOCK_TIMESTAMP);
861 		} else {
862 			sock_reset_flag(sk, SOCK_RCVTSTAMP);
863 			sock_reset_flag(sk, SOCK_RCVTSTAMPNS);
864 		}
865 		break;
866 
867 	case SO_TIMESTAMPING:
868 		if (val & ~SOF_TIMESTAMPING_MASK) {
869 			ret = -EINVAL;
870 			break;
871 		}
872 
873 		if (val & SOF_TIMESTAMPING_OPT_ID &&
874 		    !(sk->sk_tsflags & SOF_TIMESTAMPING_OPT_ID)) {
875 			if (sk->sk_protocol == IPPROTO_TCP &&
876 			    sk->sk_type == SOCK_STREAM) {
877 				if ((1 << sk->sk_state) &
878 				    (TCPF_CLOSE | TCPF_LISTEN)) {
879 					ret = -EINVAL;
880 					break;
881 				}
882 				sk->sk_tskey = tcp_sk(sk)->snd_una;
883 			} else {
884 				sk->sk_tskey = 0;
885 			}
886 		}
887 
888 		if (val & SOF_TIMESTAMPING_OPT_STATS &&
889 		    !(val & SOF_TIMESTAMPING_OPT_TSONLY)) {
890 			ret = -EINVAL;
891 			break;
892 		}
893 
894 		sk->sk_tsflags = val;
895 		if (val & SOF_TIMESTAMPING_RX_SOFTWARE)
896 			sock_enable_timestamp(sk,
897 					      SOCK_TIMESTAMPING_RX_SOFTWARE);
898 		else
899 			sock_disable_timestamp(sk,
900 					       (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE));
901 		break;
902 
903 	case SO_RCVLOWAT:
904 		if (val < 0)
905 			val = INT_MAX;
906 		sk->sk_rcvlowat = val ? : 1;
907 		break;
908 
909 	case SO_RCVTIMEO:
910 		ret = sock_set_timeout(&sk->sk_rcvtimeo, optval, optlen);
911 		break;
912 
913 	case SO_SNDTIMEO:
914 		ret = sock_set_timeout(&sk->sk_sndtimeo, optval, optlen);
915 		break;
916 
917 	case SO_ATTACH_FILTER:
918 		ret = -EINVAL;
919 		if (optlen == sizeof(struct sock_fprog)) {
920 			struct sock_fprog fprog;
921 
922 			ret = -EFAULT;
923 			if (copy_from_user(&fprog, optval, sizeof(fprog)))
924 				break;
925 
926 			ret = sk_attach_filter(&fprog, sk);
927 		}
928 		break;
929 
930 	case SO_ATTACH_BPF:
931 		ret = -EINVAL;
932 		if (optlen == sizeof(u32)) {
933 			u32 ufd;
934 
935 			ret = -EFAULT;
936 			if (copy_from_user(&ufd, optval, sizeof(ufd)))
937 				break;
938 
939 			ret = sk_attach_bpf(ufd, sk);
940 		}
941 		break;
942 
943 	case SO_ATTACH_REUSEPORT_CBPF:
944 		ret = -EINVAL;
945 		if (optlen == sizeof(struct sock_fprog)) {
946 			struct sock_fprog fprog;
947 
948 			ret = -EFAULT;
949 			if (copy_from_user(&fprog, optval, sizeof(fprog)))
950 				break;
951 
952 			ret = sk_reuseport_attach_filter(&fprog, sk);
953 		}
954 		break;
955 
956 	case SO_ATTACH_REUSEPORT_EBPF:
957 		ret = -EINVAL;
958 		if (optlen == sizeof(u32)) {
959 			u32 ufd;
960 
961 			ret = -EFAULT;
962 			if (copy_from_user(&ufd, optval, sizeof(ufd)))
963 				break;
964 
965 			ret = sk_reuseport_attach_bpf(ufd, sk);
966 		}
967 		break;
968 
969 	case SO_DETACH_FILTER:
970 		ret = sk_detach_filter(sk);
971 		break;
972 
973 	case SO_LOCK_FILTER:
974 		if (sock_flag(sk, SOCK_FILTER_LOCKED) && !valbool)
975 			ret = -EPERM;
976 		else
977 			sock_valbool_flag(sk, SOCK_FILTER_LOCKED, valbool);
978 		break;
979 
980 	case SO_PASSSEC:
981 		if (valbool)
982 			set_bit(SOCK_PASSSEC, &sock->flags);
983 		else
984 			clear_bit(SOCK_PASSSEC, &sock->flags);
985 		break;
986 	case SO_MARK:
987 		if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
988 			ret = -EPERM;
989 		else
990 			sk->sk_mark = val;
991 		break;
992 
993 	case SO_RXQ_OVFL:
994 		sock_valbool_flag(sk, SOCK_RXQ_OVFL, valbool);
995 		break;
996 
997 	case SO_WIFI_STATUS:
998 		sock_valbool_flag(sk, SOCK_WIFI_STATUS, valbool);
999 		break;
1000 
1001 	case SO_PEEK_OFF:
1002 		if (sock->ops->set_peek_off)
1003 			ret = sock->ops->set_peek_off(sk, val);
1004 		else
1005 			ret = -EOPNOTSUPP;
1006 		break;
1007 
1008 	case SO_NOFCS:
1009 		sock_valbool_flag(sk, SOCK_NOFCS, valbool);
1010 		break;
1011 
1012 	case SO_SELECT_ERR_QUEUE:
1013 		sock_valbool_flag(sk, SOCK_SELECT_ERR_QUEUE, valbool);
1014 		break;
1015 
1016 #ifdef CONFIG_NET_RX_BUSY_POLL
1017 	case SO_BUSY_POLL:
1018 		/* allow unprivileged users to decrease the value */
1019 		if ((val > sk->sk_ll_usec) && !capable(CAP_NET_ADMIN))
1020 			ret = -EPERM;
1021 		else {
1022 			if (val < 0)
1023 				ret = -EINVAL;
1024 			else
1025 				sk->sk_ll_usec = val;
1026 		}
1027 		break;
1028 #endif
1029 
1030 	case SO_MAX_PACING_RATE:
1031 		if (val != ~0U)
1032 			cmpxchg(&sk->sk_pacing_status,
1033 				SK_PACING_NONE,
1034 				SK_PACING_NEEDED);
1035 		sk->sk_max_pacing_rate = val;
1036 		sk->sk_pacing_rate = min(sk->sk_pacing_rate,
1037 					 sk->sk_max_pacing_rate);
1038 		break;
1039 
1040 	case SO_INCOMING_CPU:
1041 		sk->sk_incoming_cpu = val;
1042 		break;
1043 
1044 	case SO_CNX_ADVICE:
1045 		if (val == 1)
1046 			dst_negative_advice(sk);
1047 		break;
1048 
1049 	case SO_ZEROCOPY:
1050 		if (sk->sk_family != PF_INET && sk->sk_family != PF_INET6)
1051 			ret = -ENOTSUPP;
1052 		else if (sk->sk_protocol != IPPROTO_TCP)
1053 			ret = -ENOTSUPP;
1054 		else if (sk->sk_state != TCP_CLOSE)
1055 			ret = -EBUSY;
1056 		else if (val < 0 || val > 1)
1057 			ret = -EINVAL;
1058 		else
1059 			sock_valbool_flag(sk, SOCK_ZEROCOPY, valbool);
1060 		break;
1061 
1062 	default:
1063 		ret = -ENOPROTOOPT;
1064 		break;
1065 	}
1066 	release_sock(sk);
1067 	return ret;
1068 }
1069 EXPORT_SYMBOL(sock_setsockopt);
1070 
1071 
1072 static void cred_to_ucred(struct pid *pid, const struct cred *cred,
1073 			  struct ucred *ucred)
1074 {
1075 	ucred->pid = pid_vnr(pid);
1076 	ucred->uid = ucred->gid = -1;
1077 	if (cred) {
1078 		struct user_namespace *current_ns = current_user_ns();
1079 
1080 		ucred->uid = from_kuid_munged(current_ns, cred->euid);
1081 		ucred->gid = from_kgid_munged(current_ns, cred->egid);
1082 	}
1083 }
1084 
1085 static int groups_to_user(gid_t __user *dst, const struct group_info *src)
1086 {
1087 	struct user_namespace *user_ns = current_user_ns();
1088 	int i;
1089 
1090 	for (i = 0; i < src->ngroups; i++)
1091 		if (put_user(from_kgid_munged(user_ns, src->gid[i]), dst + i))
1092 			return -EFAULT;
1093 
1094 	return 0;
1095 }
1096 
1097 int sock_getsockopt(struct socket *sock, int level, int optname,
1098 		    char __user *optval, int __user *optlen)
1099 {
1100 	struct sock *sk = sock->sk;
1101 
1102 	union {
1103 		int val;
1104 		u64 val64;
1105 		struct linger ling;
1106 		struct timeval tm;
1107 	} v;
1108 
1109 	int lv = sizeof(int);
1110 	int len;
1111 
1112 	if (get_user(len, optlen))
1113 		return -EFAULT;
1114 	if (len < 0)
1115 		return -EINVAL;
1116 
1117 	memset(&v, 0, sizeof(v));
1118 
1119 	switch (optname) {
1120 	case SO_DEBUG:
1121 		v.val = sock_flag(sk, SOCK_DBG);
1122 		break;
1123 
1124 	case SO_DONTROUTE:
1125 		v.val = sock_flag(sk, SOCK_LOCALROUTE);
1126 		break;
1127 
1128 	case SO_BROADCAST:
1129 		v.val = sock_flag(sk, SOCK_BROADCAST);
1130 		break;
1131 
1132 	case SO_SNDBUF:
1133 		v.val = sk->sk_sndbuf;
1134 		break;
1135 
1136 	case SO_RCVBUF:
1137 		v.val = sk->sk_rcvbuf;
1138 		break;
1139 
1140 	case SO_REUSEADDR:
1141 		v.val = sk->sk_reuse;
1142 		break;
1143 
1144 	case SO_REUSEPORT:
1145 		v.val = sk->sk_reuseport;
1146 		break;
1147 
1148 	case SO_KEEPALIVE:
1149 		v.val = sock_flag(sk, SOCK_KEEPOPEN);
1150 		break;
1151 
1152 	case SO_TYPE:
1153 		v.val = sk->sk_type;
1154 		break;
1155 
1156 	case SO_PROTOCOL:
1157 		v.val = sk->sk_protocol;
1158 		break;
1159 
1160 	case SO_DOMAIN:
1161 		v.val = sk->sk_family;
1162 		break;
1163 
1164 	case SO_ERROR:
1165 		v.val = -sock_error(sk);
1166 		if (v.val == 0)
1167 			v.val = xchg(&sk->sk_err_soft, 0);
1168 		break;
1169 
1170 	case SO_OOBINLINE:
1171 		v.val = sock_flag(sk, SOCK_URGINLINE);
1172 		break;
1173 
1174 	case SO_NO_CHECK:
1175 		v.val = sk->sk_no_check_tx;
1176 		break;
1177 
1178 	case SO_PRIORITY:
1179 		v.val = sk->sk_priority;
1180 		break;
1181 
1182 	case SO_LINGER:
1183 		lv		= sizeof(v.ling);
1184 		v.ling.l_onoff	= sock_flag(sk, SOCK_LINGER);
1185 		v.ling.l_linger	= sk->sk_lingertime / HZ;
1186 		break;
1187 
1188 	case SO_BSDCOMPAT:
1189 		sock_warn_obsolete_bsdism("getsockopt");
1190 		break;
1191 
1192 	case SO_TIMESTAMP:
1193 		v.val = sock_flag(sk, SOCK_RCVTSTAMP) &&
1194 				!sock_flag(sk, SOCK_RCVTSTAMPNS);
1195 		break;
1196 
1197 	case SO_TIMESTAMPNS:
1198 		v.val = sock_flag(sk, SOCK_RCVTSTAMPNS);
1199 		break;
1200 
1201 	case SO_TIMESTAMPING:
1202 		v.val = sk->sk_tsflags;
1203 		break;
1204 
1205 	case SO_RCVTIMEO:
1206 		lv = sizeof(struct timeval);
1207 		if (sk->sk_rcvtimeo == MAX_SCHEDULE_TIMEOUT) {
1208 			v.tm.tv_sec = 0;
1209 			v.tm.tv_usec = 0;
1210 		} else {
1211 			v.tm.tv_sec = sk->sk_rcvtimeo / HZ;
1212 			v.tm.tv_usec = ((sk->sk_rcvtimeo % HZ) * USEC_PER_SEC) / HZ;
1213 		}
1214 		break;
1215 
1216 	case SO_SNDTIMEO:
1217 		lv = sizeof(struct timeval);
1218 		if (sk->sk_sndtimeo == MAX_SCHEDULE_TIMEOUT) {
1219 			v.tm.tv_sec = 0;
1220 			v.tm.tv_usec = 0;
1221 		} else {
1222 			v.tm.tv_sec = sk->sk_sndtimeo / HZ;
1223 			v.tm.tv_usec = ((sk->sk_sndtimeo % HZ) * USEC_PER_SEC) / HZ;
1224 		}
1225 		break;
1226 
1227 	case SO_RCVLOWAT:
1228 		v.val = sk->sk_rcvlowat;
1229 		break;
1230 
1231 	case SO_SNDLOWAT:
1232 		v.val = 1;
1233 		break;
1234 
1235 	case SO_PASSCRED:
1236 		v.val = !!test_bit(SOCK_PASSCRED, &sock->flags);
1237 		break;
1238 
1239 	case SO_PEERCRED:
1240 	{
1241 		struct ucred peercred;
1242 		if (len > sizeof(peercred))
1243 			len = sizeof(peercred);
1244 		cred_to_ucred(sk->sk_peer_pid, sk->sk_peer_cred, &peercred);
1245 		if (copy_to_user(optval, &peercred, len))
1246 			return -EFAULT;
1247 		goto lenout;
1248 	}
1249 
1250 	case SO_PEERGROUPS:
1251 	{
1252 		int ret, n;
1253 
1254 		if (!sk->sk_peer_cred)
1255 			return -ENODATA;
1256 
1257 		n = sk->sk_peer_cred->group_info->ngroups;
1258 		if (len < n * sizeof(gid_t)) {
1259 			len = n * sizeof(gid_t);
1260 			return put_user(len, optlen) ? -EFAULT : -ERANGE;
1261 		}
1262 		len = n * sizeof(gid_t);
1263 
1264 		ret = groups_to_user((gid_t __user *)optval,
1265 				     sk->sk_peer_cred->group_info);
1266 		if (ret)
1267 			return ret;
1268 		goto lenout;
1269 	}
1270 
1271 	case SO_PEERNAME:
1272 	{
1273 		char address[128];
1274 
1275 		if (sock->ops->getname(sock, (struct sockaddr *)address, &lv, 2))
1276 			return -ENOTCONN;
1277 		if (lv < len)
1278 			return -EINVAL;
1279 		if (copy_to_user(optval, address, len))
1280 			return -EFAULT;
1281 		goto lenout;
1282 	}
1283 
1284 	/* Dubious BSD thing... Probably nobody even uses it, but
1285 	 * the UNIX standard wants it for whatever reason... -DaveM
1286 	 */
1287 	case SO_ACCEPTCONN:
1288 		v.val = sk->sk_state == TCP_LISTEN;
1289 		break;
1290 
1291 	case SO_PASSSEC:
1292 		v.val = !!test_bit(SOCK_PASSSEC, &sock->flags);
1293 		break;
1294 
1295 	case SO_PEERSEC:
1296 		return security_socket_getpeersec_stream(sock, optval, optlen, len);
1297 
1298 	case SO_MARK:
1299 		v.val = sk->sk_mark;
1300 		break;
1301 
1302 	case SO_RXQ_OVFL:
1303 		v.val = sock_flag(sk, SOCK_RXQ_OVFL);
1304 		break;
1305 
1306 	case SO_WIFI_STATUS:
1307 		v.val = sock_flag(sk, SOCK_WIFI_STATUS);
1308 		break;
1309 
1310 	case SO_PEEK_OFF:
1311 		if (!sock->ops->set_peek_off)
1312 			return -EOPNOTSUPP;
1313 
1314 		v.val = sk->sk_peek_off;
1315 		break;
1316 	case SO_NOFCS:
1317 		v.val = sock_flag(sk, SOCK_NOFCS);
1318 		break;
1319 
1320 	case SO_BINDTODEVICE:
1321 		return sock_getbindtodevice(sk, optval, optlen, len);
1322 
1323 	case SO_GET_FILTER:
1324 		len = sk_get_filter(sk, (struct sock_filter __user *)optval, len);
1325 		if (len < 0)
1326 			return len;
1327 
1328 		goto lenout;
1329 
1330 	case SO_LOCK_FILTER:
1331 		v.val = sock_flag(sk, SOCK_FILTER_LOCKED);
1332 		break;
1333 
1334 	case SO_BPF_EXTENSIONS:
1335 		v.val = bpf_tell_extensions();
1336 		break;
1337 
1338 	case SO_SELECT_ERR_QUEUE:
1339 		v.val = sock_flag(sk, SOCK_SELECT_ERR_QUEUE);
1340 		break;
1341 
1342 #ifdef CONFIG_NET_RX_BUSY_POLL
1343 	case SO_BUSY_POLL:
1344 		v.val = sk->sk_ll_usec;
1345 		break;
1346 #endif
1347 
1348 	case SO_MAX_PACING_RATE:
1349 		v.val = sk->sk_max_pacing_rate;
1350 		break;
1351 
1352 	case SO_INCOMING_CPU:
1353 		v.val = sk->sk_incoming_cpu;
1354 		break;
1355 
1356 	case SO_MEMINFO:
1357 	{
1358 		u32 meminfo[SK_MEMINFO_VARS];
1359 
1360 		if (get_user(len, optlen))
1361 			return -EFAULT;
1362 
1363 		sk_get_meminfo(sk, meminfo);
1364 
1365 		len = min_t(unsigned int, len, sizeof(meminfo));
1366 		if (copy_to_user(optval, &meminfo, len))
1367 			return -EFAULT;
1368 
1369 		goto lenout;
1370 	}
1371 
1372 #ifdef CONFIG_NET_RX_BUSY_POLL
1373 	case SO_INCOMING_NAPI_ID:
1374 		v.val = READ_ONCE(sk->sk_napi_id);
1375 
1376 		/* aggregate non-NAPI IDs down to 0 */
1377 		if (v.val < MIN_NAPI_ID)
1378 			v.val = 0;
1379 
1380 		break;
1381 #endif
1382 
1383 	case SO_COOKIE:
1384 		lv = sizeof(u64);
1385 		if (len < lv)
1386 			return -EINVAL;
1387 		v.val64 = sock_gen_cookie(sk);
1388 		break;
1389 
1390 	case SO_ZEROCOPY:
1391 		v.val = sock_flag(sk, SOCK_ZEROCOPY);
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_net_set(sk, net);
1537 		refcount_set(&sk->sk_wmem_alloc, 1);
1538 
1539 		mem_cgroup_sk_alloc(sk);
1540 		cgroup_sk_alloc(&sk->sk_cgrp_data);
1541 		sock_update_classid(&sk->sk_cgrp_data);
1542 		sock_update_netprioidx(&sk->sk_cgrp_data);
1543 	}
1544 
1545 	return sk;
1546 }
1547 EXPORT_SYMBOL(sk_alloc);
1548 
1549 /* Sockets having SOCK_RCU_FREE will call this function after one RCU
1550  * grace period. This is the case for UDP sockets and TCP listeners.
1551  */
1552 static void __sk_destruct(struct rcu_head *head)
1553 {
1554 	struct sock *sk = container_of(head, struct sock, sk_rcu);
1555 	struct sk_filter *filter;
1556 
1557 	if (sk->sk_destruct)
1558 		sk->sk_destruct(sk);
1559 
1560 	filter = rcu_dereference_check(sk->sk_filter,
1561 				       refcount_read(&sk->sk_wmem_alloc) == 0);
1562 	if (filter) {
1563 		sk_filter_uncharge(sk, filter);
1564 		RCU_INIT_POINTER(sk->sk_filter, NULL);
1565 	}
1566 	if (rcu_access_pointer(sk->sk_reuseport_cb))
1567 		reuseport_detach_sock(sk);
1568 
1569 	sock_disable_timestamp(sk, SK_FLAGS_TIMESTAMP);
1570 
1571 	if (atomic_read(&sk->sk_omem_alloc))
1572 		pr_debug("%s: optmem leakage (%d bytes) detected\n",
1573 			 __func__, atomic_read(&sk->sk_omem_alloc));
1574 
1575 	if (sk->sk_frag.page) {
1576 		put_page(sk->sk_frag.page);
1577 		sk->sk_frag.page = NULL;
1578 	}
1579 
1580 	if (sk->sk_peer_cred)
1581 		put_cred(sk->sk_peer_cred);
1582 	put_pid(sk->sk_peer_pid);
1583 	if (likely(sk->sk_net_refcnt))
1584 		put_net(sock_net(sk));
1585 	sk_prot_free(sk->sk_prot_creator, sk);
1586 }
1587 
1588 void sk_destruct(struct sock *sk)
1589 {
1590 	if (sock_flag(sk, SOCK_RCU_FREE))
1591 		call_rcu(&sk->sk_rcu, __sk_destruct);
1592 	else
1593 		__sk_destruct(&sk->sk_rcu);
1594 }
1595 
1596 static void __sk_free(struct sock *sk)
1597 {
1598 	if (unlikely(sock_diag_has_destroy_listeners(sk) && sk->sk_net_refcnt))
1599 		sock_diag_broadcast_destroy(sk);
1600 	else
1601 		sk_destruct(sk);
1602 }
1603 
1604 void sk_free(struct sock *sk)
1605 {
1606 	/*
1607 	 * We subtract one from sk_wmem_alloc and can know if
1608 	 * some packets are still in some tx queue.
1609 	 * If not null, sock_wfree() will call __sk_free(sk) later
1610 	 */
1611 	if (refcount_dec_and_test(&sk->sk_wmem_alloc))
1612 		__sk_free(sk);
1613 }
1614 EXPORT_SYMBOL(sk_free);
1615 
1616 static void sk_init_common(struct sock *sk)
1617 {
1618 	skb_queue_head_init(&sk->sk_receive_queue);
1619 	skb_queue_head_init(&sk->sk_write_queue);
1620 	skb_queue_head_init(&sk->sk_error_queue);
1621 
1622 	rwlock_init(&sk->sk_callback_lock);
1623 	lockdep_set_class_and_name(&sk->sk_receive_queue.lock,
1624 			af_rlock_keys + sk->sk_family,
1625 			af_family_rlock_key_strings[sk->sk_family]);
1626 	lockdep_set_class_and_name(&sk->sk_write_queue.lock,
1627 			af_wlock_keys + sk->sk_family,
1628 			af_family_wlock_key_strings[sk->sk_family]);
1629 	lockdep_set_class_and_name(&sk->sk_error_queue.lock,
1630 			af_elock_keys + sk->sk_family,
1631 			af_family_elock_key_strings[sk->sk_family]);
1632 	lockdep_set_class_and_name(&sk->sk_callback_lock,
1633 			af_callback_keys + sk->sk_family,
1634 			af_family_clock_key_strings[sk->sk_family]);
1635 }
1636 
1637 /**
1638  *	sk_clone_lock - clone a socket, and lock its clone
1639  *	@sk: the socket to clone
1640  *	@priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
1641  *
1642  *	Caller must unlock socket even in error path (bh_unlock_sock(newsk))
1643  */
1644 struct sock *sk_clone_lock(const struct sock *sk, const gfp_t priority)
1645 {
1646 	struct sock *newsk;
1647 	bool is_charged = true;
1648 
1649 	newsk = sk_prot_alloc(sk->sk_prot, priority, sk->sk_family);
1650 	if (newsk != NULL) {
1651 		struct sk_filter *filter;
1652 
1653 		sock_copy(newsk, sk);
1654 
1655 		newsk->sk_prot_creator = sk->sk_prot;
1656 
1657 		/* SANITY */
1658 		if (likely(newsk->sk_net_refcnt))
1659 			get_net(sock_net(newsk));
1660 		sk_node_init(&newsk->sk_node);
1661 		sock_lock_init(newsk);
1662 		bh_lock_sock(newsk);
1663 		newsk->sk_backlog.head	= newsk->sk_backlog.tail = NULL;
1664 		newsk->sk_backlog.len = 0;
1665 
1666 		atomic_set(&newsk->sk_rmem_alloc, 0);
1667 		/*
1668 		 * sk_wmem_alloc set to one (see sk_free() and sock_wfree())
1669 		 */
1670 		refcount_set(&newsk->sk_wmem_alloc, 1);
1671 		atomic_set(&newsk->sk_omem_alloc, 0);
1672 		sk_init_common(newsk);
1673 
1674 		newsk->sk_dst_cache	= NULL;
1675 		newsk->sk_dst_pending_confirm = 0;
1676 		newsk->sk_wmem_queued	= 0;
1677 		newsk->sk_forward_alloc = 0;
1678 
1679 		/* sk->sk_memcg will be populated at accept() time */
1680 		newsk->sk_memcg = NULL;
1681 
1682 		atomic_set(&newsk->sk_drops, 0);
1683 		newsk->sk_send_head	= NULL;
1684 		newsk->sk_userlocks	= sk->sk_userlocks & ~SOCK_BINDPORT_LOCK;
1685 		atomic_set(&newsk->sk_zckey, 0);
1686 
1687 		sock_reset_flag(newsk, SOCK_DONE);
1688 		cgroup_sk_alloc(&newsk->sk_cgrp_data);
1689 
1690 		rcu_read_lock();
1691 		filter = rcu_dereference(sk->sk_filter);
1692 		if (filter != NULL)
1693 			/* though it's an empty new sock, the charging may fail
1694 			 * if sysctl_optmem_max was changed between creation of
1695 			 * original socket and cloning
1696 			 */
1697 			is_charged = sk_filter_charge(newsk, filter);
1698 		RCU_INIT_POINTER(newsk->sk_filter, filter);
1699 		rcu_read_unlock();
1700 
1701 		if (unlikely(!is_charged || xfrm_sk_clone_policy(newsk, sk))) {
1702 			/* We need to make sure that we don't uncharge the new
1703 			 * socket if we couldn't charge it in the first place
1704 			 * as otherwise we uncharge the parent's filter.
1705 			 */
1706 			if (!is_charged)
1707 				RCU_INIT_POINTER(newsk->sk_filter, NULL);
1708 			sk_free_unlock_clone(newsk);
1709 			newsk = NULL;
1710 			goto out;
1711 		}
1712 		RCU_INIT_POINTER(newsk->sk_reuseport_cb, NULL);
1713 
1714 		newsk->sk_err	   = 0;
1715 		newsk->sk_err_soft = 0;
1716 		newsk->sk_priority = 0;
1717 		newsk->sk_incoming_cpu = raw_smp_processor_id();
1718 		atomic64_set(&newsk->sk_cookie, 0);
1719 
1720 		/*
1721 		 * Before updating sk_refcnt, we must commit prior changes to memory
1722 		 * (Documentation/RCU/rculist_nulls.txt for details)
1723 		 */
1724 		smp_wmb();
1725 		refcount_set(&newsk->sk_refcnt, 2);
1726 
1727 		/*
1728 		 * Increment the counter in the same struct proto as the master
1729 		 * sock (sk_refcnt_debug_inc uses newsk->sk_prot->socks, that
1730 		 * is the same as sk->sk_prot->socks, as this field was copied
1731 		 * with memcpy).
1732 		 *
1733 		 * This _changes_ the previous behaviour, where
1734 		 * tcp_create_openreq_child always was incrementing the
1735 		 * equivalent to tcp_prot->socks (inet_sock_nr), so this have
1736 		 * to be taken into account in all callers. -acme
1737 		 */
1738 		sk_refcnt_debug_inc(newsk);
1739 		sk_set_socket(newsk, NULL);
1740 		newsk->sk_wq = NULL;
1741 
1742 		if (newsk->sk_prot->sockets_allocated)
1743 			sk_sockets_allocated_inc(newsk);
1744 
1745 		if (sock_needs_netstamp(sk) &&
1746 		    newsk->sk_flags & SK_FLAGS_TIMESTAMP)
1747 			net_enable_timestamp();
1748 	}
1749 out:
1750 	return newsk;
1751 }
1752 EXPORT_SYMBOL_GPL(sk_clone_lock);
1753 
1754 void sk_free_unlock_clone(struct sock *sk)
1755 {
1756 	/* It is still raw copy of parent, so invalidate
1757 	 * destructor and make plain sk_free() */
1758 	sk->sk_destruct = NULL;
1759 	bh_unlock_sock(sk);
1760 	sk_free(sk);
1761 }
1762 EXPORT_SYMBOL_GPL(sk_free_unlock_clone);
1763 
1764 void sk_setup_caps(struct sock *sk, struct dst_entry *dst)
1765 {
1766 	u32 max_segs = 1;
1767 
1768 	sk_dst_set(sk, dst);
1769 	sk->sk_route_caps = dst->dev->features;
1770 	if (sk->sk_route_caps & NETIF_F_GSO)
1771 		sk->sk_route_caps |= NETIF_F_GSO_SOFTWARE;
1772 	sk->sk_route_caps &= ~sk->sk_route_nocaps;
1773 	if (sk_can_gso(sk)) {
1774 		if (dst->header_len && !xfrm_dst_offload_ok(dst)) {
1775 			sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
1776 		} else {
1777 			sk->sk_route_caps |= NETIF_F_SG | NETIF_F_HW_CSUM;
1778 			sk->sk_gso_max_size = dst->dev->gso_max_size;
1779 			max_segs = max_t(u32, dst->dev->gso_max_segs, 1);
1780 		}
1781 	}
1782 	sk->sk_gso_max_segs = max_segs;
1783 }
1784 EXPORT_SYMBOL_GPL(sk_setup_caps);
1785 
1786 /*
1787  *	Simple resource managers for sockets.
1788  */
1789 
1790 
1791 /*
1792  * Write buffer destructor automatically called from kfree_skb.
1793  */
1794 void sock_wfree(struct sk_buff *skb)
1795 {
1796 	struct sock *sk = skb->sk;
1797 	unsigned int len = skb->truesize;
1798 
1799 	if (!sock_flag(sk, SOCK_USE_WRITE_QUEUE)) {
1800 		/*
1801 		 * Keep a reference on sk_wmem_alloc, this will be released
1802 		 * after sk_write_space() call
1803 		 */
1804 		WARN_ON(refcount_sub_and_test(len - 1, &sk->sk_wmem_alloc));
1805 		sk->sk_write_space(sk);
1806 		len = 1;
1807 	}
1808 	/*
1809 	 * if sk_wmem_alloc reaches 0, we must finish what sk_free()
1810 	 * could not do because of in-flight packets
1811 	 */
1812 	if (refcount_sub_and_test(len, &sk->sk_wmem_alloc))
1813 		__sk_free(sk);
1814 }
1815 EXPORT_SYMBOL(sock_wfree);
1816 
1817 /* This variant of sock_wfree() is used by TCP,
1818  * since it sets SOCK_USE_WRITE_QUEUE.
1819  */
1820 void __sock_wfree(struct sk_buff *skb)
1821 {
1822 	struct sock *sk = skb->sk;
1823 
1824 	if (refcount_sub_and_test(skb->truesize, &sk->sk_wmem_alloc))
1825 		__sk_free(sk);
1826 }
1827 
1828 void skb_set_owner_w(struct sk_buff *skb, struct sock *sk)
1829 {
1830 	skb_orphan(skb);
1831 	skb->sk = sk;
1832 #ifdef CONFIG_INET
1833 	if (unlikely(!sk_fullsock(sk))) {
1834 		skb->destructor = sock_edemux;
1835 		sock_hold(sk);
1836 		return;
1837 	}
1838 #endif
1839 	skb->destructor = sock_wfree;
1840 	skb_set_hash_from_sk(skb, sk);
1841 	/*
1842 	 * We used to take a refcount on sk, but following operation
1843 	 * is enough to guarantee sk_free() wont free this sock until
1844 	 * all in-flight packets are completed
1845 	 */
1846 	refcount_add(skb->truesize, &sk->sk_wmem_alloc);
1847 }
1848 EXPORT_SYMBOL(skb_set_owner_w);
1849 
1850 /* This helper is used by netem, as it can hold packets in its
1851  * delay queue. We want to allow the owner socket to send more
1852  * packets, as if they were already TX completed by a typical driver.
1853  * But we also want to keep skb->sk set because some packet schedulers
1854  * rely on it (sch_fq for example).
1855  */
1856 void skb_orphan_partial(struct sk_buff *skb)
1857 {
1858 	if (skb_is_tcp_pure_ack(skb))
1859 		return;
1860 
1861 	if (skb->destructor == sock_wfree
1862 #ifdef CONFIG_INET
1863 	    || skb->destructor == tcp_wfree
1864 #endif
1865 		) {
1866 		struct sock *sk = skb->sk;
1867 
1868 		if (refcount_inc_not_zero(&sk->sk_refcnt)) {
1869 			WARN_ON(refcount_sub_and_test(skb->truesize, &sk->sk_wmem_alloc));
1870 			skb->destructor = sock_efree;
1871 		}
1872 	} else {
1873 		skb_orphan(skb);
1874 	}
1875 }
1876 EXPORT_SYMBOL(skb_orphan_partial);
1877 
1878 /*
1879  * Read buffer destructor automatically called from kfree_skb.
1880  */
1881 void sock_rfree(struct sk_buff *skb)
1882 {
1883 	struct sock *sk = skb->sk;
1884 	unsigned int len = skb->truesize;
1885 
1886 	atomic_sub(len, &sk->sk_rmem_alloc);
1887 	sk_mem_uncharge(sk, len);
1888 }
1889 EXPORT_SYMBOL(sock_rfree);
1890 
1891 /*
1892  * Buffer destructor for skbs that are not used directly in read or write
1893  * path, e.g. for error handler skbs. Automatically called from kfree_skb.
1894  */
1895 void sock_efree(struct sk_buff *skb)
1896 {
1897 	sock_put(skb->sk);
1898 }
1899 EXPORT_SYMBOL(sock_efree);
1900 
1901 kuid_t sock_i_uid(struct sock *sk)
1902 {
1903 	kuid_t uid;
1904 
1905 	read_lock_bh(&sk->sk_callback_lock);
1906 	uid = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_uid : GLOBAL_ROOT_UID;
1907 	read_unlock_bh(&sk->sk_callback_lock);
1908 	return uid;
1909 }
1910 EXPORT_SYMBOL(sock_i_uid);
1911 
1912 unsigned long sock_i_ino(struct sock *sk)
1913 {
1914 	unsigned long ino;
1915 
1916 	read_lock_bh(&sk->sk_callback_lock);
1917 	ino = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_ino : 0;
1918 	read_unlock_bh(&sk->sk_callback_lock);
1919 	return ino;
1920 }
1921 EXPORT_SYMBOL(sock_i_ino);
1922 
1923 /*
1924  * Allocate a skb from the socket's send buffer.
1925  */
1926 struct sk_buff *sock_wmalloc(struct sock *sk, unsigned long size, int force,
1927 			     gfp_t priority)
1928 {
1929 	if (force || refcount_read(&sk->sk_wmem_alloc) < sk->sk_sndbuf) {
1930 		struct sk_buff *skb = alloc_skb(size, priority);
1931 		if (skb) {
1932 			skb_set_owner_w(skb, sk);
1933 			return skb;
1934 		}
1935 	}
1936 	return NULL;
1937 }
1938 EXPORT_SYMBOL(sock_wmalloc);
1939 
1940 static void sock_ofree(struct sk_buff *skb)
1941 {
1942 	struct sock *sk = skb->sk;
1943 
1944 	atomic_sub(skb->truesize, &sk->sk_omem_alloc);
1945 }
1946 
1947 struct sk_buff *sock_omalloc(struct sock *sk, unsigned long size,
1948 			     gfp_t priority)
1949 {
1950 	struct sk_buff *skb;
1951 
1952 	/* small safe race: SKB_TRUESIZE may differ from final skb->truesize */
1953 	if (atomic_read(&sk->sk_omem_alloc) + SKB_TRUESIZE(size) >
1954 	    sysctl_optmem_max)
1955 		return NULL;
1956 
1957 	skb = alloc_skb(size, priority);
1958 	if (!skb)
1959 		return NULL;
1960 
1961 	atomic_add(skb->truesize, &sk->sk_omem_alloc);
1962 	skb->sk = sk;
1963 	skb->destructor = sock_ofree;
1964 	return skb;
1965 }
1966 
1967 /*
1968  * Allocate a memory block from the socket's option memory buffer.
1969  */
1970 void *sock_kmalloc(struct sock *sk, int size, gfp_t priority)
1971 {
1972 	if ((unsigned int)size <= sysctl_optmem_max &&
1973 	    atomic_read(&sk->sk_omem_alloc) + size < sysctl_optmem_max) {
1974 		void *mem;
1975 		/* First do the add, to avoid the race if kmalloc
1976 		 * might sleep.
1977 		 */
1978 		atomic_add(size, &sk->sk_omem_alloc);
1979 		mem = kmalloc(size, priority);
1980 		if (mem)
1981 			return mem;
1982 		atomic_sub(size, &sk->sk_omem_alloc);
1983 	}
1984 	return NULL;
1985 }
1986 EXPORT_SYMBOL(sock_kmalloc);
1987 
1988 /* Free an option memory block. Note, we actually want the inline
1989  * here as this allows gcc to detect the nullify and fold away the
1990  * condition entirely.
1991  */
1992 static inline void __sock_kfree_s(struct sock *sk, void *mem, int size,
1993 				  const bool nullify)
1994 {
1995 	if (WARN_ON_ONCE(!mem))
1996 		return;
1997 	if (nullify)
1998 		kzfree(mem);
1999 	else
2000 		kfree(mem);
2001 	atomic_sub(size, &sk->sk_omem_alloc);
2002 }
2003 
2004 void sock_kfree_s(struct sock *sk, void *mem, int size)
2005 {
2006 	__sock_kfree_s(sk, mem, size, false);
2007 }
2008 EXPORT_SYMBOL(sock_kfree_s);
2009 
2010 void sock_kzfree_s(struct sock *sk, void *mem, int size)
2011 {
2012 	__sock_kfree_s(sk, mem, size, true);
2013 }
2014 EXPORT_SYMBOL(sock_kzfree_s);
2015 
2016 /* It is almost wait_for_tcp_memory minus release_sock/lock_sock.
2017    I think, these locks should be removed for datagram sockets.
2018  */
2019 static long sock_wait_for_wmem(struct sock *sk, long timeo)
2020 {
2021 	DEFINE_WAIT(wait);
2022 
2023 	sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
2024 	for (;;) {
2025 		if (!timeo)
2026 			break;
2027 		if (signal_pending(current))
2028 			break;
2029 		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
2030 		prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
2031 		if (refcount_read(&sk->sk_wmem_alloc) < sk->sk_sndbuf)
2032 			break;
2033 		if (sk->sk_shutdown & SEND_SHUTDOWN)
2034 			break;
2035 		if (sk->sk_err)
2036 			break;
2037 		timeo = schedule_timeout(timeo);
2038 	}
2039 	finish_wait(sk_sleep(sk), &wait);
2040 	return timeo;
2041 }
2042 
2043 
2044 /*
2045  *	Generic send/receive buffer handlers
2046  */
2047 
2048 struct sk_buff *sock_alloc_send_pskb(struct sock *sk, unsigned long header_len,
2049 				     unsigned long data_len, int noblock,
2050 				     int *errcode, int max_page_order)
2051 {
2052 	struct sk_buff *skb;
2053 	long timeo;
2054 	int err;
2055 
2056 	timeo = sock_sndtimeo(sk, noblock);
2057 	for (;;) {
2058 		err = sock_error(sk);
2059 		if (err != 0)
2060 			goto failure;
2061 
2062 		err = -EPIPE;
2063 		if (sk->sk_shutdown & SEND_SHUTDOWN)
2064 			goto failure;
2065 
2066 		if (sk_wmem_alloc_get(sk) < sk->sk_sndbuf)
2067 			break;
2068 
2069 		sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
2070 		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
2071 		err = -EAGAIN;
2072 		if (!timeo)
2073 			goto failure;
2074 		if (signal_pending(current))
2075 			goto interrupted;
2076 		timeo = sock_wait_for_wmem(sk, timeo);
2077 	}
2078 	skb = alloc_skb_with_frags(header_len, data_len, max_page_order,
2079 				   errcode, sk->sk_allocation);
2080 	if (skb)
2081 		skb_set_owner_w(skb, sk);
2082 	return skb;
2083 
2084 interrupted:
2085 	err = sock_intr_errno(timeo);
2086 failure:
2087 	*errcode = err;
2088 	return NULL;
2089 }
2090 EXPORT_SYMBOL(sock_alloc_send_pskb);
2091 
2092 struct sk_buff *sock_alloc_send_skb(struct sock *sk, unsigned long size,
2093 				    int noblock, int *errcode)
2094 {
2095 	return sock_alloc_send_pskb(sk, size, 0, noblock, errcode, 0);
2096 }
2097 EXPORT_SYMBOL(sock_alloc_send_skb);
2098 
2099 int __sock_cmsg_send(struct sock *sk, struct msghdr *msg, struct cmsghdr *cmsg,
2100 		     struct sockcm_cookie *sockc)
2101 {
2102 	u32 tsflags;
2103 
2104 	switch (cmsg->cmsg_type) {
2105 	case SO_MARK:
2106 		if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
2107 			return -EPERM;
2108 		if (cmsg->cmsg_len != CMSG_LEN(sizeof(u32)))
2109 			return -EINVAL;
2110 		sockc->mark = *(u32 *)CMSG_DATA(cmsg);
2111 		break;
2112 	case SO_TIMESTAMPING:
2113 		if (cmsg->cmsg_len != CMSG_LEN(sizeof(u32)))
2114 			return -EINVAL;
2115 
2116 		tsflags = *(u32 *)CMSG_DATA(cmsg);
2117 		if (tsflags & ~SOF_TIMESTAMPING_TX_RECORD_MASK)
2118 			return -EINVAL;
2119 
2120 		sockc->tsflags &= ~SOF_TIMESTAMPING_TX_RECORD_MASK;
2121 		sockc->tsflags |= tsflags;
2122 		break;
2123 	/* SCM_RIGHTS and SCM_CREDENTIALS are semantically in SOL_UNIX. */
2124 	case SCM_RIGHTS:
2125 	case SCM_CREDENTIALS:
2126 		break;
2127 	default:
2128 		return -EINVAL;
2129 	}
2130 	return 0;
2131 }
2132 EXPORT_SYMBOL(__sock_cmsg_send);
2133 
2134 int sock_cmsg_send(struct sock *sk, struct msghdr *msg,
2135 		   struct sockcm_cookie *sockc)
2136 {
2137 	struct cmsghdr *cmsg;
2138 	int ret;
2139 
2140 	for_each_cmsghdr(cmsg, msg) {
2141 		if (!CMSG_OK(msg, cmsg))
2142 			return -EINVAL;
2143 		if (cmsg->cmsg_level != SOL_SOCKET)
2144 			continue;
2145 		ret = __sock_cmsg_send(sk, msg, cmsg, sockc);
2146 		if (ret)
2147 			return ret;
2148 	}
2149 	return 0;
2150 }
2151 EXPORT_SYMBOL(sock_cmsg_send);
2152 
2153 static void sk_enter_memory_pressure(struct sock *sk)
2154 {
2155 	if (!sk->sk_prot->enter_memory_pressure)
2156 		return;
2157 
2158 	sk->sk_prot->enter_memory_pressure(sk);
2159 }
2160 
2161 static void sk_leave_memory_pressure(struct sock *sk)
2162 {
2163 	if (sk->sk_prot->leave_memory_pressure) {
2164 		sk->sk_prot->leave_memory_pressure(sk);
2165 	} else {
2166 		unsigned long *memory_pressure = sk->sk_prot->memory_pressure;
2167 
2168 		if (memory_pressure && *memory_pressure)
2169 			*memory_pressure = 0;
2170 	}
2171 }
2172 
2173 /* On 32bit arches, an skb frag is limited to 2^15 */
2174 #define SKB_FRAG_PAGE_ORDER	get_order(32768)
2175 
2176 /**
2177  * skb_page_frag_refill - check that a page_frag contains enough room
2178  * @sz: minimum size of the fragment we want to get
2179  * @pfrag: pointer to page_frag
2180  * @gfp: priority for memory allocation
2181  *
2182  * Note: While this allocator tries to use high order pages, there is
2183  * no guarantee that allocations succeed. Therefore, @sz MUST be
2184  * less or equal than PAGE_SIZE.
2185  */
2186 bool skb_page_frag_refill(unsigned int sz, struct page_frag *pfrag, gfp_t gfp)
2187 {
2188 	if (pfrag->page) {
2189 		if (page_ref_count(pfrag->page) == 1) {
2190 			pfrag->offset = 0;
2191 			return true;
2192 		}
2193 		if (pfrag->offset + sz <= pfrag->size)
2194 			return true;
2195 		put_page(pfrag->page);
2196 	}
2197 
2198 	pfrag->offset = 0;
2199 	if (SKB_FRAG_PAGE_ORDER) {
2200 		/* Avoid direct reclaim but allow kswapd to wake */
2201 		pfrag->page = alloc_pages((gfp & ~__GFP_DIRECT_RECLAIM) |
2202 					  __GFP_COMP | __GFP_NOWARN |
2203 					  __GFP_NORETRY,
2204 					  SKB_FRAG_PAGE_ORDER);
2205 		if (likely(pfrag->page)) {
2206 			pfrag->size = PAGE_SIZE << SKB_FRAG_PAGE_ORDER;
2207 			return true;
2208 		}
2209 	}
2210 	pfrag->page = alloc_page(gfp);
2211 	if (likely(pfrag->page)) {
2212 		pfrag->size = PAGE_SIZE;
2213 		return true;
2214 	}
2215 	return false;
2216 }
2217 EXPORT_SYMBOL(skb_page_frag_refill);
2218 
2219 bool sk_page_frag_refill(struct sock *sk, struct page_frag *pfrag)
2220 {
2221 	if (likely(skb_page_frag_refill(32U, pfrag, sk->sk_allocation)))
2222 		return true;
2223 
2224 	sk_enter_memory_pressure(sk);
2225 	sk_stream_moderate_sndbuf(sk);
2226 	return false;
2227 }
2228 EXPORT_SYMBOL(sk_page_frag_refill);
2229 
2230 static void __lock_sock(struct sock *sk)
2231 	__releases(&sk->sk_lock.slock)
2232 	__acquires(&sk->sk_lock.slock)
2233 {
2234 	DEFINE_WAIT(wait);
2235 
2236 	for (;;) {
2237 		prepare_to_wait_exclusive(&sk->sk_lock.wq, &wait,
2238 					TASK_UNINTERRUPTIBLE);
2239 		spin_unlock_bh(&sk->sk_lock.slock);
2240 		schedule();
2241 		spin_lock_bh(&sk->sk_lock.slock);
2242 		if (!sock_owned_by_user(sk))
2243 			break;
2244 	}
2245 	finish_wait(&sk->sk_lock.wq, &wait);
2246 }
2247 
2248 static void __release_sock(struct sock *sk)
2249 	__releases(&sk->sk_lock.slock)
2250 	__acquires(&sk->sk_lock.slock)
2251 {
2252 	struct sk_buff *skb, *next;
2253 
2254 	while ((skb = sk->sk_backlog.head) != NULL) {
2255 		sk->sk_backlog.head = sk->sk_backlog.tail = NULL;
2256 
2257 		spin_unlock_bh(&sk->sk_lock.slock);
2258 
2259 		do {
2260 			next = skb->next;
2261 			prefetch(next);
2262 			WARN_ON_ONCE(skb_dst_is_noref(skb));
2263 			skb->next = NULL;
2264 			sk_backlog_rcv(sk, skb);
2265 
2266 			cond_resched();
2267 
2268 			skb = next;
2269 		} while (skb != NULL);
2270 
2271 		spin_lock_bh(&sk->sk_lock.slock);
2272 	}
2273 
2274 	/*
2275 	 * Doing the zeroing here guarantee we can not loop forever
2276 	 * while a wild producer attempts to flood us.
2277 	 */
2278 	sk->sk_backlog.len = 0;
2279 }
2280 
2281 void __sk_flush_backlog(struct sock *sk)
2282 {
2283 	spin_lock_bh(&sk->sk_lock.slock);
2284 	__release_sock(sk);
2285 	spin_unlock_bh(&sk->sk_lock.slock);
2286 }
2287 
2288 /**
2289  * sk_wait_data - wait for data to arrive at sk_receive_queue
2290  * @sk:    sock to wait on
2291  * @timeo: for how long
2292  * @skb:   last skb seen on sk_receive_queue
2293  *
2294  * Now socket state including sk->sk_err is changed only under lock,
2295  * hence we may omit checks after joining wait queue.
2296  * We check receive queue before schedule() only as optimization;
2297  * it is very likely that release_sock() added new data.
2298  */
2299 int sk_wait_data(struct sock *sk, long *timeo, const struct sk_buff *skb)
2300 {
2301 	DEFINE_WAIT_FUNC(wait, woken_wake_function);
2302 	int rc;
2303 
2304 	add_wait_queue(sk_sleep(sk), &wait);
2305 	sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
2306 	rc = sk_wait_event(sk, timeo, skb_peek_tail(&sk->sk_receive_queue) != skb, &wait);
2307 	sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
2308 	remove_wait_queue(sk_sleep(sk), &wait);
2309 	return rc;
2310 }
2311 EXPORT_SYMBOL(sk_wait_data);
2312 
2313 /**
2314  *	__sk_mem_raise_allocated - increase memory_allocated
2315  *	@sk: socket
2316  *	@size: memory size to allocate
2317  *	@amt: pages to allocate
2318  *	@kind: allocation type
2319  *
2320  *	Similar to __sk_mem_schedule(), but does not update sk_forward_alloc
2321  */
2322 int __sk_mem_raise_allocated(struct sock *sk, int size, int amt, int kind)
2323 {
2324 	struct proto *prot = sk->sk_prot;
2325 	long allocated = sk_memory_allocated_add(sk, amt);
2326 
2327 	if (mem_cgroup_sockets_enabled && sk->sk_memcg &&
2328 	    !mem_cgroup_charge_skmem(sk->sk_memcg, amt))
2329 		goto suppress_allocation;
2330 
2331 	/* Under limit. */
2332 	if (allocated <= sk_prot_mem_limits(sk, 0)) {
2333 		sk_leave_memory_pressure(sk);
2334 		return 1;
2335 	}
2336 
2337 	/* Under pressure. */
2338 	if (allocated > sk_prot_mem_limits(sk, 1))
2339 		sk_enter_memory_pressure(sk);
2340 
2341 	/* Over hard limit. */
2342 	if (allocated > sk_prot_mem_limits(sk, 2))
2343 		goto suppress_allocation;
2344 
2345 	/* guarantee minimum buffer size under pressure */
2346 	if (kind == SK_MEM_RECV) {
2347 		if (atomic_read(&sk->sk_rmem_alloc) < sk_get_rmem0(sk, prot))
2348 			return 1;
2349 
2350 	} else { /* SK_MEM_SEND */
2351 		int wmem0 = sk_get_wmem0(sk, prot);
2352 
2353 		if (sk->sk_type == SOCK_STREAM) {
2354 			if (sk->sk_wmem_queued < wmem0)
2355 				return 1;
2356 		} else if (refcount_read(&sk->sk_wmem_alloc) < wmem0) {
2357 				return 1;
2358 		}
2359 	}
2360 
2361 	if (sk_has_memory_pressure(sk)) {
2362 		int alloc;
2363 
2364 		if (!sk_under_memory_pressure(sk))
2365 			return 1;
2366 		alloc = sk_sockets_allocated_read_positive(sk);
2367 		if (sk_prot_mem_limits(sk, 2) > alloc *
2368 		    sk_mem_pages(sk->sk_wmem_queued +
2369 				 atomic_read(&sk->sk_rmem_alloc) +
2370 				 sk->sk_forward_alloc))
2371 			return 1;
2372 	}
2373 
2374 suppress_allocation:
2375 
2376 	if (kind == SK_MEM_SEND && sk->sk_type == SOCK_STREAM) {
2377 		sk_stream_moderate_sndbuf(sk);
2378 
2379 		/* Fail only if socket is _under_ its sndbuf.
2380 		 * In this case we cannot block, so that we have to fail.
2381 		 */
2382 		if (sk->sk_wmem_queued + size >= sk->sk_sndbuf)
2383 			return 1;
2384 	}
2385 
2386 	trace_sock_exceed_buf_limit(sk, prot, allocated);
2387 
2388 	sk_memory_allocated_sub(sk, amt);
2389 
2390 	if (mem_cgroup_sockets_enabled && sk->sk_memcg)
2391 		mem_cgroup_uncharge_skmem(sk->sk_memcg, amt);
2392 
2393 	return 0;
2394 }
2395 EXPORT_SYMBOL(__sk_mem_raise_allocated);
2396 
2397 /**
2398  *	__sk_mem_schedule - increase sk_forward_alloc and memory_allocated
2399  *	@sk: socket
2400  *	@size: memory size to allocate
2401  *	@kind: allocation type
2402  *
2403  *	If kind is SK_MEM_SEND, it means wmem allocation. Otherwise it means
2404  *	rmem allocation. This function assumes that protocols which have
2405  *	memory_pressure use sk_wmem_queued as write buffer accounting.
2406  */
2407 int __sk_mem_schedule(struct sock *sk, int size, int kind)
2408 {
2409 	int ret, amt = sk_mem_pages(size);
2410 
2411 	sk->sk_forward_alloc += amt << SK_MEM_QUANTUM_SHIFT;
2412 	ret = __sk_mem_raise_allocated(sk, size, amt, kind);
2413 	if (!ret)
2414 		sk->sk_forward_alloc -= amt << SK_MEM_QUANTUM_SHIFT;
2415 	return ret;
2416 }
2417 EXPORT_SYMBOL(__sk_mem_schedule);
2418 
2419 /**
2420  *	__sk_mem_reduce_allocated - reclaim memory_allocated
2421  *	@sk: socket
2422  *	@amount: number of quanta
2423  *
2424  *	Similar to __sk_mem_reclaim(), but does not update sk_forward_alloc
2425  */
2426 void __sk_mem_reduce_allocated(struct sock *sk, int amount)
2427 {
2428 	sk_memory_allocated_sub(sk, amount);
2429 
2430 	if (mem_cgroup_sockets_enabled && sk->sk_memcg)
2431 		mem_cgroup_uncharge_skmem(sk->sk_memcg, amount);
2432 
2433 	if (sk_under_memory_pressure(sk) &&
2434 	    (sk_memory_allocated(sk) < sk_prot_mem_limits(sk, 0)))
2435 		sk_leave_memory_pressure(sk);
2436 }
2437 EXPORT_SYMBOL(__sk_mem_reduce_allocated);
2438 
2439 /**
2440  *	__sk_mem_reclaim - reclaim sk_forward_alloc and memory_allocated
2441  *	@sk: socket
2442  *	@amount: number of bytes (rounded down to a SK_MEM_QUANTUM multiple)
2443  */
2444 void __sk_mem_reclaim(struct sock *sk, int amount)
2445 {
2446 	amount >>= SK_MEM_QUANTUM_SHIFT;
2447 	sk->sk_forward_alloc -= amount << SK_MEM_QUANTUM_SHIFT;
2448 	__sk_mem_reduce_allocated(sk, amount);
2449 }
2450 EXPORT_SYMBOL(__sk_mem_reclaim);
2451 
2452 int sk_set_peek_off(struct sock *sk, int val)
2453 {
2454 	sk->sk_peek_off = val;
2455 	return 0;
2456 }
2457 EXPORT_SYMBOL_GPL(sk_set_peek_off);
2458 
2459 /*
2460  * Set of default routines for initialising struct proto_ops when
2461  * the protocol does not support a particular function. In certain
2462  * cases where it makes no sense for a protocol to have a "do nothing"
2463  * function, some default processing is provided.
2464  */
2465 
2466 int sock_no_bind(struct socket *sock, struct sockaddr *saddr, int len)
2467 {
2468 	return -EOPNOTSUPP;
2469 }
2470 EXPORT_SYMBOL(sock_no_bind);
2471 
2472 int sock_no_connect(struct socket *sock, struct sockaddr *saddr,
2473 		    int len, int flags)
2474 {
2475 	return -EOPNOTSUPP;
2476 }
2477 EXPORT_SYMBOL(sock_no_connect);
2478 
2479 int sock_no_socketpair(struct socket *sock1, struct socket *sock2)
2480 {
2481 	return -EOPNOTSUPP;
2482 }
2483 EXPORT_SYMBOL(sock_no_socketpair);
2484 
2485 int sock_no_accept(struct socket *sock, struct socket *newsock, int flags,
2486 		   bool kern)
2487 {
2488 	return -EOPNOTSUPP;
2489 }
2490 EXPORT_SYMBOL(sock_no_accept);
2491 
2492 int sock_no_getname(struct socket *sock, struct sockaddr *saddr,
2493 		    int *len, int peer)
2494 {
2495 	return -EOPNOTSUPP;
2496 }
2497 EXPORT_SYMBOL(sock_no_getname);
2498 
2499 unsigned int sock_no_poll(struct file *file, struct socket *sock, poll_table *pt)
2500 {
2501 	return 0;
2502 }
2503 EXPORT_SYMBOL(sock_no_poll);
2504 
2505 int sock_no_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
2506 {
2507 	return -EOPNOTSUPP;
2508 }
2509 EXPORT_SYMBOL(sock_no_ioctl);
2510 
2511 int sock_no_listen(struct socket *sock, int backlog)
2512 {
2513 	return -EOPNOTSUPP;
2514 }
2515 EXPORT_SYMBOL(sock_no_listen);
2516 
2517 int sock_no_shutdown(struct socket *sock, int how)
2518 {
2519 	return -EOPNOTSUPP;
2520 }
2521 EXPORT_SYMBOL(sock_no_shutdown);
2522 
2523 int sock_no_setsockopt(struct socket *sock, int level, int optname,
2524 		    char __user *optval, unsigned int optlen)
2525 {
2526 	return -EOPNOTSUPP;
2527 }
2528 EXPORT_SYMBOL(sock_no_setsockopt);
2529 
2530 int sock_no_getsockopt(struct socket *sock, int level, int optname,
2531 		    char __user *optval, int __user *optlen)
2532 {
2533 	return -EOPNOTSUPP;
2534 }
2535 EXPORT_SYMBOL(sock_no_getsockopt);
2536 
2537 int sock_no_sendmsg(struct socket *sock, struct msghdr *m, size_t len)
2538 {
2539 	return -EOPNOTSUPP;
2540 }
2541 EXPORT_SYMBOL(sock_no_sendmsg);
2542 
2543 int sock_no_sendmsg_locked(struct sock *sk, struct msghdr *m, size_t len)
2544 {
2545 	return -EOPNOTSUPP;
2546 }
2547 EXPORT_SYMBOL(sock_no_sendmsg_locked);
2548 
2549 int sock_no_recvmsg(struct socket *sock, struct msghdr *m, size_t len,
2550 		    int flags)
2551 {
2552 	return -EOPNOTSUPP;
2553 }
2554 EXPORT_SYMBOL(sock_no_recvmsg);
2555 
2556 int sock_no_mmap(struct file *file, struct socket *sock, struct vm_area_struct *vma)
2557 {
2558 	/* Mirror missing mmap method error code */
2559 	return -ENODEV;
2560 }
2561 EXPORT_SYMBOL(sock_no_mmap);
2562 
2563 ssize_t sock_no_sendpage(struct socket *sock, struct page *page, int offset, size_t size, int flags)
2564 {
2565 	ssize_t res;
2566 	struct msghdr msg = {.msg_flags = flags};
2567 	struct kvec iov;
2568 	char *kaddr = kmap(page);
2569 	iov.iov_base = kaddr + offset;
2570 	iov.iov_len = size;
2571 	res = kernel_sendmsg(sock, &msg, &iov, 1, size);
2572 	kunmap(page);
2573 	return res;
2574 }
2575 EXPORT_SYMBOL(sock_no_sendpage);
2576 
2577 ssize_t sock_no_sendpage_locked(struct sock *sk, struct page *page,
2578 				int offset, size_t size, int flags)
2579 {
2580 	ssize_t res;
2581 	struct msghdr msg = {.msg_flags = flags};
2582 	struct kvec iov;
2583 	char *kaddr = kmap(page);
2584 
2585 	iov.iov_base = kaddr + offset;
2586 	iov.iov_len = size;
2587 	res = kernel_sendmsg_locked(sk, &msg, &iov, 1, size);
2588 	kunmap(page);
2589 	return res;
2590 }
2591 EXPORT_SYMBOL(sock_no_sendpage_locked);
2592 
2593 /*
2594  *	Default Socket Callbacks
2595  */
2596 
2597 static void sock_def_wakeup(struct sock *sk)
2598 {
2599 	struct socket_wq *wq;
2600 
2601 	rcu_read_lock();
2602 	wq = rcu_dereference(sk->sk_wq);
2603 	if (skwq_has_sleeper(wq))
2604 		wake_up_interruptible_all(&wq->wait);
2605 	rcu_read_unlock();
2606 }
2607 
2608 static void sock_def_error_report(struct sock *sk)
2609 {
2610 	struct socket_wq *wq;
2611 
2612 	rcu_read_lock();
2613 	wq = rcu_dereference(sk->sk_wq);
2614 	if (skwq_has_sleeper(wq))
2615 		wake_up_interruptible_poll(&wq->wait, POLLERR);
2616 	sk_wake_async(sk, SOCK_WAKE_IO, POLL_ERR);
2617 	rcu_read_unlock();
2618 }
2619 
2620 static void sock_def_readable(struct sock *sk)
2621 {
2622 	struct socket_wq *wq;
2623 
2624 	rcu_read_lock();
2625 	wq = rcu_dereference(sk->sk_wq);
2626 	if (skwq_has_sleeper(wq))
2627 		wake_up_interruptible_sync_poll(&wq->wait, POLLIN | POLLPRI |
2628 						POLLRDNORM | POLLRDBAND);
2629 	sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
2630 	rcu_read_unlock();
2631 }
2632 
2633 static void sock_def_write_space(struct sock *sk)
2634 {
2635 	struct socket_wq *wq;
2636 
2637 	rcu_read_lock();
2638 
2639 	/* Do not wake up a writer until he can make "significant"
2640 	 * progress.  --DaveM
2641 	 */
2642 	if ((refcount_read(&sk->sk_wmem_alloc) << 1) <= sk->sk_sndbuf) {
2643 		wq = rcu_dereference(sk->sk_wq);
2644 		if (skwq_has_sleeper(wq))
2645 			wake_up_interruptible_sync_poll(&wq->wait, POLLOUT |
2646 						POLLWRNORM | POLLWRBAND);
2647 
2648 		/* Should agree with poll, otherwise some programs break */
2649 		if (sock_writeable(sk))
2650 			sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
2651 	}
2652 
2653 	rcu_read_unlock();
2654 }
2655 
2656 static void sock_def_destruct(struct sock *sk)
2657 {
2658 }
2659 
2660 void sk_send_sigurg(struct sock *sk)
2661 {
2662 	if (sk->sk_socket && sk->sk_socket->file)
2663 		if (send_sigurg(&sk->sk_socket->file->f_owner))
2664 			sk_wake_async(sk, SOCK_WAKE_URG, POLL_PRI);
2665 }
2666 EXPORT_SYMBOL(sk_send_sigurg);
2667 
2668 void sk_reset_timer(struct sock *sk, struct timer_list* timer,
2669 		    unsigned long expires)
2670 {
2671 	if (!mod_timer(timer, expires))
2672 		sock_hold(sk);
2673 }
2674 EXPORT_SYMBOL(sk_reset_timer);
2675 
2676 void sk_stop_timer(struct sock *sk, struct timer_list* timer)
2677 {
2678 	if (del_timer(timer))
2679 		__sock_put(sk);
2680 }
2681 EXPORT_SYMBOL(sk_stop_timer);
2682 
2683 void sock_init_data(struct socket *sock, struct sock *sk)
2684 {
2685 	sk_init_common(sk);
2686 	sk->sk_send_head	=	NULL;
2687 
2688 	timer_setup(&sk->sk_timer, NULL, 0);
2689 
2690 	sk->sk_allocation	=	GFP_KERNEL;
2691 	sk->sk_rcvbuf		=	sysctl_rmem_default;
2692 	sk->sk_sndbuf		=	sysctl_wmem_default;
2693 	sk->sk_state		=	TCP_CLOSE;
2694 	sk_set_socket(sk, sock);
2695 
2696 	sock_set_flag(sk, SOCK_ZAPPED);
2697 
2698 	if (sock) {
2699 		sk->sk_type	=	sock->type;
2700 		sk->sk_wq	=	sock->wq;
2701 		sock->sk	=	sk;
2702 		sk->sk_uid	=	SOCK_INODE(sock)->i_uid;
2703 	} else {
2704 		sk->sk_wq	=	NULL;
2705 		sk->sk_uid	=	make_kuid(sock_net(sk)->user_ns, 0);
2706 	}
2707 
2708 	rwlock_init(&sk->sk_callback_lock);
2709 	if (sk->sk_kern_sock)
2710 		lockdep_set_class_and_name(
2711 			&sk->sk_callback_lock,
2712 			af_kern_callback_keys + sk->sk_family,
2713 			af_family_kern_clock_key_strings[sk->sk_family]);
2714 	else
2715 		lockdep_set_class_and_name(
2716 			&sk->sk_callback_lock,
2717 			af_callback_keys + sk->sk_family,
2718 			af_family_clock_key_strings[sk->sk_family]);
2719 
2720 	sk->sk_state_change	=	sock_def_wakeup;
2721 	sk->sk_data_ready	=	sock_def_readable;
2722 	sk->sk_write_space	=	sock_def_write_space;
2723 	sk->sk_error_report	=	sock_def_error_report;
2724 	sk->sk_destruct		=	sock_def_destruct;
2725 
2726 	sk->sk_frag.page	=	NULL;
2727 	sk->sk_frag.offset	=	0;
2728 	sk->sk_peek_off		=	-1;
2729 
2730 	sk->sk_peer_pid 	=	NULL;
2731 	sk->sk_peer_cred	=	NULL;
2732 	sk->sk_write_pending	=	0;
2733 	sk->sk_rcvlowat		=	1;
2734 	sk->sk_rcvtimeo		=	MAX_SCHEDULE_TIMEOUT;
2735 	sk->sk_sndtimeo		=	MAX_SCHEDULE_TIMEOUT;
2736 
2737 	sk->sk_stamp = SK_DEFAULT_STAMP;
2738 	atomic_set(&sk->sk_zckey, 0);
2739 
2740 #ifdef CONFIG_NET_RX_BUSY_POLL
2741 	sk->sk_napi_id		=	0;
2742 	sk->sk_ll_usec		=	sysctl_net_busy_read;
2743 #endif
2744 
2745 	sk->sk_max_pacing_rate = ~0U;
2746 	sk->sk_pacing_rate = ~0U;
2747 	sk->sk_pacing_shift = 10;
2748 	sk->sk_incoming_cpu = -1;
2749 	/*
2750 	 * Before updating sk_refcnt, we must commit prior changes to memory
2751 	 * (Documentation/RCU/rculist_nulls.txt for details)
2752 	 */
2753 	smp_wmb();
2754 	refcount_set(&sk->sk_refcnt, 1);
2755 	atomic_set(&sk->sk_drops, 0);
2756 }
2757 EXPORT_SYMBOL(sock_init_data);
2758 
2759 void lock_sock_nested(struct sock *sk, int subclass)
2760 {
2761 	might_sleep();
2762 	spin_lock_bh(&sk->sk_lock.slock);
2763 	if (sk->sk_lock.owned)
2764 		__lock_sock(sk);
2765 	sk->sk_lock.owned = 1;
2766 	spin_unlock(&sk->sk_lock.slock);
2767 	/*
2768 	 * The sk_lock has mutex_lock() semantics here:
2769 	 */
2770 	mutex_acquire(&sk->sk_lock.dep_map, subclass, 0, _RET_IP_);
2771 	local_bh_enable();
2772 }
2773 EXPORT_SYMBOL(lock_sock_nested);
2774 
2775 void release_sock(struct sock *sk)
2776 {
2777 	spin_lock_bh(&sk->sk_lock.slock);
2778 	if (sk->sk_backlog.tail)
2779 		__release_sock(sk);
2780 
2781 	/* Warning : release_cb() might need to release sk ownership,
2782 	 * ie call sock_release_ownership(sk) before us.
2783 	 */
2784 	if (sk->sk_prot->release_cb)
2785 		sk->sk_prot->release_cb(sk);
2786 
2787 	sock_release_ownership(sk);
2788 	if (waitqueue_active(&sk->sk_lock.wq))
2789 		wake_up(&sk->sk_lock.wq);
2790 	spin_unlock_bh(&sk->sk_lock.slock);
2791 }
2792 EXPORT_SYMBOL(release_sock);
2793 
2794 /**
2795  * lock_sock_fast - fast version of lock_sock
2796  * @sk: socket
2797  *
2798  * This version should be used for very small section, where process wont block
2799  * return false if fast path is taken:
2800  *
2801  *   sk_lock.slock locked, owned = 0, BH disabled
2802  *
2803  * return true if slow path is taken:
2804  *
2805  *   sk_lock.slock unlocked, owned = 1, BH enabled
2806  */
2807 bool lock_sock_fast(struct sock *sk)
2808 {
2809 	might_sleep();
2810 	spin_lock_bh(&sk->sk_lock.slock);
2811 
2812 	if (!sk->sk_lock.owned)
2813 		/*
2814 		 * Note : We must disable BH
2815 		 */
2816 		return false;
2817 
2818 	__lock_sock(sk);
2819 	sk->sk_lock.owned = 1;
2820 	spin_unlock(&sk->sk_lock.slock);
2821 	/*
2822 	 * The sk_lock has mutex_lock() semantics here:
2823 	 */
2824 	mutex_acquire(&sk->sk_lock.dep_map, 0, 0, _RET_IP_);
2825 	local_bh_enable();
2826 	return true;
2827 }
2828 EXPORT_SYMBOL(lock_sock_fast);
2829 
2830 int sock_get_timestamp(struct sock *sk, struct timeval __user *userstamp)
2831 {
2832 	struct timeval tv;
2833 	if (!sock_flag(sk, SOCK_TIMESTAMP))
2834 		sock_enable_timestamp(sk, SOCK_TIMESTAMP);
2835 	tv = ktime_to_timeval(sk->sk_stamp);
2836 	if (tv.tv_sec == -1)
2837 		return -ENOENT;
2838 	if (tv.tv_sec == 0) {
2839 		sk->sk_stamp = ktime_get_real();
2840 		tv = ktime_to_timeval(sk->sk_stamp);
2841 	}
2842 	return copy_to_user(userstamp, &tv, sizeof(tv)) ? -EFAULT : 0;
2843 }
2844 EXPORT_SYMBOL(sock_get_timestamp);
2845 
2846 int sock_get_timestampns(struct sock *sk, struct timespec __user *userstamp)
2847 {
2848 	struct timespec ts;
2849 	if (!sock_flag(sk, SOCK_TIMESTAMP))
2850 		sock_enable_timestamp(sk, SOCK_TIMESTAMP);
2851 	ts = ktime_to_timespec(sk->sk_stamp);
2852 	if (ts.tv_sec == -1)
2853 		return -ENOENT;
2854 	if (ts.tv_sec == 0) {
2855 		sk->sk_stamp = ktime_get_real();
2856 		ts = ktime_to_timespec(sk->sk_stamp);
2857 	}
2858 	return copy_to_user(userstamp, &ts, sizeof(ts)) ? -EFAULT : 0;
2859 }
2860 EXPORT_SYMBOL(sock_get_timestampns);
2861 
2862 void sock_enable_timestamp(struct sock *sk, int flag)
2863 {
2864 	if (!sock_flag(sk, flag)) {
2865 		unsigned long previous_flags = sk->sk_flags;
2866 
2867 		sock_set_flag(sk, flag);
2868 		/*
2869 		 * we just set one of the two flags which require net
2870 		 * time stamping, but time stamping might have been on
2871 		 * already because of the other one
2872 		 */
2873 		if (sock_needs_netstamp(sk) &&
2874 		    !(previous_flags & SK_FLAGS_TIMESTAMP))
2875 			net_enable_timestamp();
2876 	}
2877 }
2878 
2879 int sock_recv_errqueue(struct sock *sk, struct msghdr *msg, int len,
2880 		       int level, int type)
2881 {
2882 	struct sock_exterr_skb *serr;
2883 	struct sk_buff *skb;
2884 	int copied, err;
2885 
2886 	err = -EAGAIN;
2887 	skb = sock_dequeue_err_skb(sk);
2888 	if (skb == NULL)
2889 		goto out;
2890 
2891 	copied = skb->len;
2892 	if (copied > len) {
2893 		msg->msg_flags |= MSG_TRUNC;
2894 		copied = len;
2895 	}
2896 	err = skb_copy_datagram_msg(skb, 0, msg, copied);
2897 	if (err)
2898 		goto out_free_skb;
2899 
2900 	sock_recv_timestamp(msg, sk, skb);
2901 
2902 	serr = SKB_EXT_ERR(skb);
2903 	put_cmsg(msg, level, type, sizeof(serr->ee), &serr->ee);
2904 
2905 	msg->msg_flags |= MSG_ERRQUEUE;
2906 	err = copied;
2907 
2908 out_free_skb:
2909 	kfree_skb(skb);
2910 out:
2911 	return err;
2912 }
2913 EXPORT_SYMBOL(sock_recv_errqueue);
2914 
2915 /*
2916  *	Get a socket option on an socket.
2917  *
2918  *	FIX: POSIX 1003.1g is very ambiguous here. It states that
2919  *	asynchronous errors should be reported by getsockopt. We assume
2920  *	this means if you specify SO_ERROR (otherwise whats the point of it).
2921  */
2922 int sock_common_getsockopt(struct socket *sock, int level, int optname,
2923 			   char __user *optval, int __user *optlen)
2924 {
2925 	struct sock *sk = sock->sk;
2926 
2927 	return sk->sk_prot->getsockopt(sk, level, optname, optval, optlen);
2928 }
2929 EXPORT_SYMBOL(sock_common_getsockopt);
2930 
2931 #ifdef CONFIG_COMPAT
2932 int compat_sock_common_getsockopt(struct socket *sock, int level, int optname,
2933 				  char __user *optval, int __user *optlen)
2934 {
2935 	struct sock *sk = sock->sk;
2936 
2937 	if (sk->sk_prot->compat_getsockopt != NULL)
2938 		return sk->sk_prot->compat_getsockopt(sk, level, optname,
2939 						      optval, optlen);
2940 	return sk->sk_prot->getsockopt(sk, level, optname, optval, optlen);
2941 }
2942 EXPORT_SYMBOL(compat_sock_common_getsockopt);
2943 #endif
2944 
2945 int sock_common_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
2946 			int flags)
2947 {
2948 	struct sock *sk = sock->sk;
2949 	int addr_len = 0;
2950 	int err;
2951 
2952 	err = sk->sk_prot->recvmsg(sk, msg, size, flags & MSG_DONTWAIT,
2953 				   flags & ~MSG_DONTWAIT, &addr_len);
2954 	if (err >= 0)
2955 		msg->msg_namelen = addr_len;
2956 	return err;
2957 }
2958 EXPORT_SYMBOL(sock_common_recvmsg);
2959 
2960 /*
2961  *	Set socket options on an inet socket.
2962  */
2963 int sock_common_setsockopt(struct socket *sock, int level, int optname,
2964 			   char __user *optval, unsigned int optlen)
2965 {
2966 	struct sock *sk = sock->sk;
2967 
2968 	return sk->sk_prot->setsockopt(sk, level, optname, optval, optlen);
2969 }
2970 EXPORT_SYMBOL(sock_common_setsockopt);
2971 
2972 #ifdef CONFIG_COMPAT
2973 int compat_sock_common_setsockopt(struct socket *sock, int level, int optname,
2974 				  char __user *optval, unsigned int optlen)
2975 {
2976 	struct sock *sk = sock->sk;
2977 
2978 	if (sk->sk_prot->compat_setsockopt != NULL)
2979 		return sk->sk_prot->compat_setsockopt(sk, level, optname,
2980 						      optval, optlen);
2981 	return sk->sk_prot->setsockopt(sk, level, optname, optval, optlen);
2982 }
2983 EXPORT_SYMBOL(compat_sock_common_setsockopt);
2984 #endif
2985 
2986 void sk_common_release(struct sock *sk)
2987 {
2988 	if (sk->sk_prot->destroy)
2989 		sk->sk_prot->destroy(sk);
2990 
2991 	/*
2992 	 * Observation: when sock_common_release is called, processes have
2993 	 * no access to socket. But net still has.
2994 	 * Step one, detach it from networking:
2995 	 *
2996 	 * A. Remove from hash tables.
2997 	 */
2998 
2999 	sk->sk_prot->unhash(sk);
3000 
3001 	/*
3002 	 * In this point socket cannot receive new packets, but it is possible
3003 	 * that some packets are in flight because some CPU runs receiver and
3004 	 * did hash table lookup before we unhashed socket. They will achieve
3005 	 * receive queue and will be purged by socket destructor.
3006 	 *
3007 	 * Also we still have packets pending on receive queue and probably,
3008 	 * our own packets waiting in device queues. sock_destroy will drain
3009 	 * receive queue, but transmitted packets will delay socket destruction
3010 	 * until the last reference will be released.
3011 	 */
3012 
3013 	sock_orphan(sk);
3014 
3015 	xfrm_sk_free_policy(sk);
3016 
3017 	sk_refcnt_debug_release(sk);
3018 
3019 	sock_put(sk);
3020 }
3021 EXPORT_SYMBOL(sk_common_release);
3022 
3023 void sk_get_meminfo(const struct sock *sk, u32 *mem)
3024 {
3025 	memset(mem, 0, sizeof(*mem) * SK_MEMINFO_VARS);
3026 
3027 	mem[SK_MEMINFO_RMEM_ALLOC] = sk_rmem_alloc_get(sk);
3028 	mem[SK_MEMINFO_RCVBUF] = sk->sk_rcvbuf;
3029 	mem[SK_MEMINFO_WMEM_ALLOC] = sk_wmem_alloc_get(sk);
3030 	mem[SK_MEMINFO_SNDBUF] = sk->sk_sndbuf;
3031 	mem[SK_MEMINFO_FWD_ALLOC] = sk->sk_forward_alloc;
3032 	mem[SK_MEMINFO_WMEM_QUEUED] = sk->sk_wmem_queued;
3033 	mem[SK_MEMINFO_OPTMEM] = atomic_read(&sk->sk_omem_alloc);
3034 	mem[SK_MEMINFO_BACKLOG] = sk->sk_backlog.len;
3035 	mem[SK_MEMINFO_DROPS] = atomic_read(&sk->sk_drops);
3036 }
3037 
3038 #ifdef CONFIG_PROC_FS
3039 #define PROTO_INUSE_NR	64	/* should be enough for the first time */
3040 struct prot_inuse {
3041 	int val[PROTO_INUSE_NR];
3042 };
3043 
3044 static DECLARE_BITMAP(proto_inuse_idx, PROTO_INUSE_NR);
3045 
3046 void sock_prot_inuse_add(struct net *net, struct proto *prot, int val)
3047 {
3048 	__this_cpu_add(net->core.inuse->val[prot->inuse_idx], val);
3049 }
3050 EXPORT_SYMBOL_GPL(sock_prot_inuse_add);
3051 
3052 int sock_prot_inuse_get(struct net *net, struct proto *prot)
3053 {
3054 	int cpu, idx = prot->inuse_idx;
3055 	int res = 0;
3056 
3057 	for_each_possible_cpu(cpu)
3058 		res += per_cpu_ptr(net->core.inuse, cpu)->val[idx];
3059 
3060 	return res >= 0 ? res : 0;
3061 }
3062 EXPORT_SYMBOL_GPL(sock_prot_inuse_get);
3063 
3064 static int __net_init sock_inuse_init_net(struct net *net)
3065 {
3066 	net->core.inuse = alloc_percpu(struct prot_inuse);
3067 	return net->core.inuse ? 0 : -ENOMEM;
3068 }
3069 
3070 static void __net_exit sock_inuse_exit_net(struct net *net)
3071 {
3072 	free_percpu(net->core.inuse);
3073 }
3074 
3075 static struct pernet_operations net_inuse_ops = {
3076 	.init = sock_inuse_init_net,
3077 	.exit = sock_inuse_exit_net,
3078 };
3079 
3080 static __init int net_inuse_init(void)
3081 {
3082 	if (register_pernet_subsys(&net_inuse_ops))
3083 		panic("Cannot initialize net inuse counters");
3084 
3085 	return 0;
3086 }
3087 
3088 core_initcall(net_inuse_init);
3089 
3090 static void assign_proto_idx(struct proto *prot)
3091 {
3092 	prot->inuse_idx = find_first_zero_bit(proto_inuse_idx, PROTO_INUSE_NR);
3093 
3094 	if (unlikely(prot->inuse_idx == PROTO_INUSE_NR - 1)) {
3095 		pr_err("PROTO_INUSE_NR exhausted\n");
3096 		return;
3097 	}
3098 
3099 	set_bit(prot->inuse_idx, proto_inuse_idx);
3100 }
3101 
3102 static void release_proto_idx(struct proto *prot)
3103 {
3104 	if (prot->inuse_idx != PROTO_INUSE_NR - 1)
3105 		clear_bit(prot->inuse_idx, proto_inuse_idx);
3106 }
3107 #else
3108 static inline void assign_proto_idx(struct proto *prot)
3109 {
3110 }
3111 
3112 static inline void release_proto_idx(struct proto *prot)
3113 {
3114 }
3115 #endif
3116 
3117 static void req_prot_cleanup(struct request_sock_ops *rsk_prot)
3118 {
3119 	if (!rsk_prot)
3120 		return;
3121 	kfree(rsk_prot->slab_name);
3122 	rsk_prot->slab_name = NULL;
3123 	kmem_cache_destroy(rsk_prot->slab);
3124 	rsk_prot->slab = NULL;
3125 }
3126 
3127 static int req_prot_init(const struct proto *prot)
3128 {
3129 	struct request_sock_ops *rsk_prot = prot->rsk_prot;
3130 
3131 	if (!rsk_prot)
3132 		return 0;
3133 
3134 	rsk_prot->slab_name = kasprintf(GFP_KERNEL, "request_sock_%s",
3135 					prot->name);
3136 	if (!rsk_prot->slab_name)
3137 		return -ENOMEM;
3138 
3139 	rsk_prot->slab = kmem_cache_create(rsk_prot->slab_name,
3140 					   rsk_prot->obj_size, 0,
3141 					   prot->slab_flags, NULL);
3142 
3143 	if (!rsk_prot->slab) {
3144 		pr_crit("%s: Can't create request sock SLAB cache!\n",
3145 			prot->name);
3146 		return -ENOMEM;
3147 	}
3148 	return 0;
3149 }
3150 
3151 int proto_register(struct proto *prot, int alloc_slab)
3152 {
3153 	if (alloc_slab) {
3154 		prot->slab = kmem_cache_create(prot->name, prot->obj_size, 0,
3155 					SLAB_HWCACHE_ALIGN | prot->slab_flags,
3156 					NULL);
3157 
3158 		if (prot->slab == NULL) {
3159 			pr_crit("%s: Can't create sock SLAB cache!\n",
3160 				prot->name);
3161 			goto out;
3162 		}
3163 
3164 		if (req_prot_init(prot))
3165 			goto out_free_request_sock_slab;
3166 
3167 		if (prot->twsk_prot != NULL) {
3168 			prot->twsk_prot->twsk_slab_name = kasprintf(GFP_KERNEL, "tw_sock_%s", prot->name);
3169 
3170 			if (prot->twsk_prot->twsk_slab_name == NULL)
3171 				goto out_free_request_sock_slab;
3172 
3173 			prot->twsk_prot->twsk_slab =
3174 				kmem_cache_create(prot->twsk_prot->twsk_slab_name,
3175 						  prot->twsk_prot->twsk_obj_size,
3176 						  0,
3177 						  prot->slab_flags,
3178 						  NULL);
3179 			if (prot->twsk_prot->twsk_slab == NULL)
3180 				goto out_free_timewait_sock_slab_name;
3181 		}
3182 	}
3183 
3184 	mutex_lock(&proto_list_mutex);
3185 	list_add(&prot->node, &proto_list);
3186 	assign_proto_idx(prot);
3187 	mutex_unlock(&proto_list_mutex);
3188 	return 0;
3189 
3190 out_free_timewait_sock_slab_name:
3191 	kfree(prot->twsk_prot->twsk_slab_name);
3192 out_free_request_sock_slab:
3193 	req_prot_cleanup(prot->rsk_prot);
3194 
3195 	kmem_cache_destroy(prot->slab);
3196 	prot->slab = NULL;
3197 out:
3198 	return -ENOBUFS;
3199 }
3200 EXPORT_SYMBOL(proto_register);
3201 
3202 void proto_unregister(struct proto *prot)
3203 {
3204 	mutex_lock(&proto_list_mutex);
3205 	release_proto_idx(prot);
3206 	list_del(&prot->node);
3207 	mutex_unlock(&proto_list_mutex);
3208 
3209 	kmem_cache_destroy(prot->slab);
3210 	prot->slab = NULL;
3211 
3212 	req_prot_cleanup(prot->rsk_prot);
3213 
3214 	if (prot->twsk_prot != NULL && prot->twsk_prot->twsk_slab != NULL) {
3215 		kmem_cache_destroy(prot->twsk_prot->twsk_slab);
3216 		kfree(prot->twsk_prot->twsk_slab_name);
3217 		prot->twsk_prot->twsk_slab = NULL;
3218 	}
3219 }
3220 EXPORT_SYMBOL(proto_unregister);
3221 
3222 #ifdef CONFIG_PROC_FS
3223 static void *proto_seq_start(struct seq_file *seq, loff_t *pos)
3224 	__acquires(proto_list_mutex)
3225 {
3226 	mutex_lock(&proto_list_mutex);
3227 	return seq_list_start_head(&proto_list, *pos);
3228 }
3229 
3230 static void *proto_seq_next(struct seq_file *seq, void *v, loff_t *pos)
3231 {
3232 	return seq_list_next(v, &proto_list, pos);
3233 }
3234 
3235 static void proto_seq_stop(struct seq_file *seq, void *v)
3236 	__releases(proto_list_mutex)
3237 {
3238 	mutex_unlock(&proto_list_mutex);
3239 }
3240 
3241 static char proto_method_implemented(const void *method)
3242 {
3243 	return method == NULL ? 'n' : 'y';
3244 }
3245 static long sock_prot_memory_allocated(struct proto *proto)
3246 {
3247 	return proto->memory_allocated != NULL ? proto_memory_allocated(proto) : -1L;
3248 }
3249 
3250 static char *sock_prot_memory_pressure(struct proto *proto)
3251 {
3252 	return proto->memory_pressure != NULL ?
3253 	proto_memory_pressure(proto) ? "yes" : "no" : "NI";
3254 }
3255 
3256 static void proto_seq_printf(struct seq_file *seq, struct proto *proto)
3257 {
3258 
3259 	seq_printf(seq, "%-9s %4u %6d  %6ld   %-3s %6u   %-3s  %-10s "
3260 			"%2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c\n",
3261 		   proto->name,
3262 		   proto->obj_size,
3263 		   sock_prot_inuse_get(seq_file_net(seq), proto),
3264 		   sock_prot_memory_allocated(proto),
3265 		   sock_prot_memory_pressure(proto),
3266 		   proto->max_header,
3267 		   proto->slab == NULL ? "no" : "yes",
3268 		   module_name(proto->owner),
3269 		   proto_method_implemented(proto->close),
3270 		   proto_method_implemented(proto->connect),
3271 		   proto_method_implemented(proto->disconnect),
3272 		   proto_method_implemented(proto->accept),
3273 		   proto_method_implemented(proto->ioctl),
3274 		   proto_method_implemented(proto->init),
3275 		   proto_method_implemented(proto->destroy),
3276 		   proto_method_implemented(proto->shutdown),
3277 		   proto_method_implemented(proto->setsockopt),
3278 		   proto_method_implemented(proto->getsockopt),
3279 		   proto_method_implemented(proto->sendmsg),
3280 		   proto_method_implemented(proto->recvmsg),
3281 		   proto_method_implemented(proto->sendpage),
3282 		   proto_method_implemented(proto->bind),
3283 		   proto_method_implemented(proto->backlog_rcv),
3284 		   proto_method_implemented(proto->hash),
3285 		   proto_method_implemented(proto->unhash),
3286 		   proto_method_implemented(proto->get_port),
3287 		   proto_method_implemented(proto->enter_memory_pressure));
3288 }
3289 
3290 static int proto_seq_show(struct seq_file *seq, void *v)
3291 {
3292 	if (v == &proto_list)
3293 		seq_printf(seq, "%-9s %-4s %-8s %-6s %-5s %-7s %-4s %-10s %s",
3294 			   "protocol",
3295 			   "size",
3296 			   "sockets",
3297 			   "memory",
3298 			   "press",
3299 			   "maxhdr",
3300 			   "slab",
3301 			   "module",
3302 			   "cl co di ac io in de sh ss gs se re sp bi br ha uh gp em\n");
3303 	else
3304 		proto_seq_printf(seq, list_entry(v, struct proto, node));
3305 	return 0;
3306 }
3307 
3308 static const struct seq_operations proto_seq_ops = {
3309 	.start  = proto_seq_start,
3310 	.next   = proto_seq_next,
3311 	.stop   = proto_seq_stop,
3312 	.show   = proto_seq_show,
3313 };
3314 
3315 static int proto_seq_open(struct inode *inode, struct file *file)
3316 {
3317 	return seq_open_net(inode, file, &proto_seq_ops,
3318 			    sizeof(struct seq_net_private));
3319 }
3320 
3321 static const struct file_operations proto_seq_fops = {
3322 	.owner		= THIS_MODULE,
3323 	.open		= proto_seq_open,
3324 	.read		= seq_read,
3325 	.llseek		= seq_lseek,
3326 	.release	= seq_release_net,
3327 };
3328 
3329 static __net_init int proto_init_net(struct net *net)
3330 {
3331 	if (!proc_create("protocols", S_IRUGO, net->proc_net, &proto_seq_fops))
3332 		return -ENOMEM;
3333 
3334 	return 0;
3335 }
3336 
3337 static __net_exit void proto_exit_net(struct net *net)
3338 {
3339 	remove_proc_entry("protocols", net->proc_net);
3340 }
3341 
3342 
3343 static __net_initdata struct pernet_operations proto_net_ops = {
3344 	.init = proto_init_net,
3345 	.exit = proto_exit_net,
3346 };
3347 
3348 static int __init proto_init(void)
3349 {
3350 	return register_pernet_subsys(&proto_net_ops);
3351 }
3352 
3353 subsys_initcall(proto_init);
3354 
3355 #endif /* PROC_FS */
3356 
3357 #ifdef CONFIG_NET_RX_BUSY_POLL
3358 bool sk_busy_loop_end(void *p, unsigned long start_time)
3359 {
3360 	struct sock *sk = p;
3361 
3362 	return !skb_queue_empty(&sk->sk_receive_queue) ||
3363 	       sk_busy_loop_timeout(sk, start_time);
3364 }
3365 EXPORT_SYMBOL(sk_busy_loop_end);
3366 #endif /* CONFIG_NET_RX_BUSY_POLL */
3367