xref: /linux/net/core/sock.c (revision 74ce1896c6c65b2f8cccbf59162d542988835835)
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 		kmemcheck_annotate_bitfield(sk, flags);
1473 
1474 		if (security_sk_alloc(sk, family, priority))
1475 			goto out_free;
1476 
1477 		if (!try_module_get(prot->owner))
1478 			goto out_free_sec;
1479 		sk_tx_queue_clear(sk);
1480 	}
1481 
1482 	return sk;
1483 
1484 out_free_sec:
1485 	security_sk_free(sk);
1486 out_free:
1487 	if (slab != NULL)
1488 		kmem_cache_free(slab, sk);
1489 	else
1490 		kfree(sk);
1491 	return NULL;
1492 }
1493 
1494 static void sk_prot_free(struct proto *prot, struct sock *sk)
1495 {
1496 	struct kmem_cache *slab;
1497 	struct module *owner;
1498 
1499 	owner = prot->owner;
1500 	slab = prot->slab;
1501 
1502 	cgroup_sk_free(&sk->sk_cgrp_data);
1503 	mem_cgroup_sk_free(sk);
1504 	security_sk_free(sk);
1505 	if (slab != NULL)
1506 		kmem_cache_free(slab, sk);
1507 	else
1508 		kfree(sk);
1509 	module_put(owner);
1510 }
1511 
1512 /**
1513  *	sk_alloc - All socket objects are allocated here
1514  *	@net: the applicable net namespace
1515  *	@family: protocol family
1516  *	@priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
1517  *	@prot: struct proto associated with this new sock instance
1518  *	@kern: is this to be a kernel socket?
1519  */
1520 struct sock *sk_alloc(struct net *net, int family, gfp_t priority,
1521 		      struct proto *prot, int kern)
1522 {
1523 	struct sock *sk;
1524 
1525 	sk = sk_prot_alloc(prot, priority | __GFP_ZERO, family);
1526 	if (sk) {
1527 		sk->sk_family = family;
1528 		/*
1529 		 * See comment in struct sock definition to understand
1530 		 * why we need sk_prot_creator -acme
1531 		 */
1532 		sk->sk_prot = sk->sk_prot_creator = prot;
1533 		sk->sk_kern_sock = kern;
1534 		sock_lock_init(sk);
1535 		sk->sk_net_refcnt = kern ? 0 : 1;
1536 		if (likely(sk->sk_net_refcnt))
1537 			get_net(net);
1538 		sock_net_set(sk, net);
1539 		refcount_set(&sk->sk_wmem_alloc, 1);
1540 
1541 		mem_cgroup_sk_alloc(sk);
1542 		cgroup_sk_alloc(&sk->sk_cgrp_data);
1543 		sock_update_classid(&sk->sk_cgrp_data);
1544 		sock_update_netprioidx(&sk->sk_cgrp_data);
1545 	}
1546 
1547 	return sk;
1548 }
1549 EXPORT_SYMBOL(sk_alloc);
1550 
1551 /* Sockets having SOCK_RCU_FREE will call this function after one RCU
1552  * grace period. This is the case for UDP sockets and TCP listeners.
1553  */
1554 static void __sk_destruct(struct rcu_head *head)
1555 {
1556 	struct sock *sk = container_of(head, struct sock, sk_rcu);
1557 	struct sk_filter *filter;
1558 
1559 	if (sk->sk_destruct)
1560 		sk->sk_destruct(sk);
1561 
1562 	filter = rcu_dereference_check(sk->sk_filter,
1563 				       refcount_read(&sk->sk_wmem_alloc) == 0);
1564 	if (filter) {
1565 		sk_filter_uncharge(sk, filter);
1566 		RCU_INIT_POINTER(sk->sk_filter, NULL);
1567 	}
1568 	if (rcu_access_pointer(sk->sk_reuseport_cb))
1569 		reuseport_detach_sock(sk);
1570 
1571 	sock_disable_timestamp(sk, SK_FLAGS_TIMESTAMP);
1572 
1573 	if (atomic_read(&sk->sk_omem_alloc))
1574 		pr_debug("%s: optmem leakage (%d bytes) detected\n",
1575 			 __func__, atomic_read(&sk->sk_omem_alloc));
1576 
1577 	if (sk->sk_frag.page) {
1578 		put_page(sk->sk_frag.page);
1579 		sk->sk_frag.page = NULL;
1580 	}
1581 
1582 	if (sk->sk_peer_cred)
1583 		put_cred(sk->sk_peer_cred);
1584 	put_pid(sk->sk_peer_pid);
1585 	if (likely(sk->sk_net_refcnt))
1586 		put_net(sock_net(sk));
1587 	sk_prot_free(sk->sk_prot_creator, sk);
1588 }
1589 
1590 void sk_destruct(struct sock *sk)
1591 {
1592 	if (sock_flag(sk, SOCK_RCU_FREE))
1593 		call_rcu(&sk->sk_rcu, __sk_destruct);
1594 	else
1595 		__sk_destruct(&sk->sk_rcu);
1596 }
1597 
1598 static void __sk_free(struct sock *sk)
1599 {
1600 	if (unlikely(sock_diag_has_destroy_listeners(sk) && sk->sk_net_refcnt))
1601 		sock_diag_broadcast_destroy(sk);
1602 	else
1603 		sk_destruct(sk);
1604 }
1605 
1606 void sk_free(struct sock *sk)
1607 {
1608 	/*
1609 	 * We subtract one from sk_wmem_alloc and can know if
1610 	 * some packets are still in some tx queue.
1611 	 * If not null, sock_wfree() will call __sk_free(sk) later
1612 	 */
1613 	if (refcount_dec_and_test(&sk->sk_wmem_alloc))
1614 		__sk_free(sk);
1615 }
1616 EXPORT_SYMBOL(sk_free);
1617 
1618 static void sk_init_common(struct sock *sk)
1619 {
1620 	skb_queue_head_init(&sk->sk_receive_queue);
1621 	skb_queue_head_init(&sk->sk_write_queue);
1622 	skb_queue_head_init(&sk->sk_error_queue);
1623 
1624 	rwlock_init(&sk->sk_callback_lock);
1625 	lockdep_set_class_and_name(&sk->sk_receive_queue.lock,
1626 			af_rlock_keys + sk->sk_family,
1627 			af_family_rlock_key_strings[sk->sk_family]);
1628 	lockdep_set_class_and_name(&sk->sk_write_queue.lock,
1629 			af_wlock_keys + sk->sk_family,
1630 			af_family_wlock_key_strings[sk->sk_family]);
1631 	lockdep_set_class_and_name(&sk->sk_error_queue.lock,
1632 			af_elock_keys + sk->sk_family,
1633 			af_family_elock_key_strings[sk->sk_family]);
1634 	lockdep_set_class_and_name(&sk->sk_callback_lock,
1635 			af_callback_keys + sk->sk_family,
1636 			af_family_clock_key_strings[sk->sk_family]);
1637 }
1638 
1639 /**
1640  *	sk_clone_lock - clone a socket, and lock its clone
1641  *	@sk: the socket to clone
1642  *	@priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
1643  *
1644  *	Caller must unlock socket even in error path (bh_unlock_sock(newsk))
1645  */
1646 struct sock *sk_clone_lock(const struct sock *sk, const gfp_t priority)
1647 {
1648 	struct sock *newsk;
1649 	bool is_charged = true;
1650 
1651 	newsk = sk_prot_alloc(sk->sk_prot, priority, sk->sk_family);
1652 	if (newsk != NULL) {
1653 		struct sk_filter *filter;
1654 
1655 		sock_copy(newsk, sk);
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 		atomic_set(&newsk->sk_drops, 0);
1679 		newsk->sk_send_head	= NULL;
1680 		newsk->sk_userlocks	= sk->sk_userlocks & ~SOCK_BINDPORT_LOCK;
1681 		atomic_set(&newsk->sk_zckey, 0);
1682 
1683 		sock_reset_flag(newsk, SOCK_DONE);
1684 
1685 		filter = rcu_dereference_protected(newsk->sk_filter, 1);
1686 		if (filter != NULL)
1687 			/* though it's an empty new sock, the charging may fail
1688 			 * if sysctl_optmem_max was changed between creation of
1689 			 * original socket and cloning
1690 			 */
1691 			is_charged = sk_filter_charge(newsk, filter);
1692 
1693 		if (unlikely(!is_charged || xfrm_sk_clone_policy(newsk, sk))) {
1694 			/* We need to make sure that we don't uncharge the new
1695 			 * socket if we couldn't charge it in the first place
1696 			 * as otherwise we uncharge the parent's filter.
1697 			 */
1698 			if (!is_charged)
1699 				RCU_INIT_POINTER(newsk->sk_filter, NULL);
1700 			sk_free_unlock_clone(newsk);
1701 			newsk = NULL;
1702 			goto out;
1703 		}
1704 		RCU_INIT_POINTER(newsk->sk_reuseport_cb, NULL);
1705 
1706 		newsk->sk_err	   = 0;
1707 		newsk->sk_err_soft = 0;
1708 		newsk->sk_priority = 0;
1709 		newsk->sk_incoming_cpu = raw_smp_processor_id();
1710 		atomic64_set(&newsk->sk_cookie, 0);
1711 
1712 		mem_cgroup_sk_alloc(newsk);
1713 		cgroup_sk_alloc(&newsk->sk_cgrp_data);
1714 
1715 		/*
1716 		 * Before updating sk_refcnt, we must commit prior changes to memory
1717 		 * (Documentation/RCU/rculist_nulls.txt for details)
1718 		 */
1719 		smp_wmb();
1720 		refcount_set(&newsk->sk_refcnt, 2);
1721 
1722 		/*
1723 		 * Increment the counter in the same struct proto as the master
1724 		 * sock (sk_refcnt_debug_inc uses newsk->sk_prot->socks, that
1725 		 * is the same as sk->sk_prot->socks, as this field was copied
1726 		 * with memcpy).
1727 		 *
1728 		 * This _changes_ the previous behaviour, where
1729 		 * tcp_create_openreq_child always was incrementing the
1730 		 * equivalent to tcp_prot->socks (inet_sock_nr), so this have
1731 		 * to be taken into account in all callers. -acme
1732 		 */
1733 		sk_refcnt_debug_inc(newsk);
1734 		sk_set_socket(newsk, NULL);
1735 		newsk->sk_wq = NULL;
1736 
1737 		if (newsk->sk_prot->sockets_allocated)
1738 			sk_sockets_allocated_inc(newsk);
1739 
1740 		if (sock_needs_netstamp(sk) &&
1741 		    newsk->sk_flags & SK_FLAGS_TIMESTAMP)
1742 			net_enable_timestamp();
1743 	}
1744 out:
1745 	return newsk;
1746 }
1747 EXPORT_SYMBOL_GPL(sk_clone_lock);
1748 
1749 void sk_free_unlock_clone(struct sock *sk)
1750 {
1751 	/* It is still raw copy of parent, so invalidate
1752 	 * destructor and make plain sk_free() */
1753 	sk->sk_destruct = NULL;
1754 	bh_unlock_sock(sk);
1755 	sk_free(sk);
1756 }
1757 EXPORT_SYMBOL_GPL(sk_free_unlock_clone);
1758 
1759 void sk_setup_caps(struct sock *sk, struct dst_entry *dst)
1760 {
1761 	u32 max_segs = 1;
1762 
1763 	sk_dst_set(sk, dst);
1764 	sk->sk_route_caps = dst->dev->features;
1765 	if (sk->sk_route_caps & NETIF_F_GSO)
1766 		sk->sk_route_caps |= NETIF_F_GSO_SOFTWARE;
1767 	sk->sk_route_caps &= ~sk->sk_route_nocaps;
1768 	if (sk_can_gso(sk)) {
1769 		if (dst->header_len && !xfrm_dst_offload_ok(dst)) {
1770 			sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
1771 		} else {
1772 			sk->sk_route_caps |= NETIF_F_SG | NETIF_F_HW_CSUM;
1773 			sk->sk_gso_max_size = dst->dev->gso_max_size;
1774 			max_segs = max_t(u32, dst->dev->gso_max_segs, 1);
1775 		}
1776 	}
1777 	sk->sk_gso_max_segs = max_segs;
1778 }
1779 EXPORT_SYMBOL_GPL(sk_setup_caps);
1780 
1781 /*
1782  *	Simple resource managers for sockets.
1783  */
1784 
1785 
1786 /*
1787  * Write buffer destructor automatically called from kfree_skb.
1788  */
1789 void sock_wfree(struct sk_buff *skb)
1790 {
1791 	struct sock *sk = skb->sk;
1792 	unsigned int len = skb->truesize;
1793 
1794 	if (!sock_flag(sk, SOCK_USE_WRITE_QUEUE)) {
1795 		/*
1796 		 * Keep a reference on sk_wmem_alloc, this will be released
1797 		 * after sk_write_space() call
1798 		 */
1799 		WARN_ON(refcount_sub_and_test(len - 1, &sk->sk_wmem_alloc));
1800 		sk->sk_write_space(sk);
1801 		len = 1;
1802 	}
1803 	/*
1804 	 * if sk_wmem_alloc reaches 0, we must finish what sk_free()
1805 	 * could not do because of in-flight packets
1806 	 */
1807 	if (refcount_sub_and_test(len, &sk->sk_wmem_alloc))
1808 		__sk_free(sk);
1809 }
1810 EXPORT_SYMBOL(sock_wfree);
1811 
1812 /* This variant of sock_wfree() is used by TCP,
1813  * since it sets SOCK_USE_WRITE_QUEUE.
1814  */
1815 void __sock_wfree(struct sk_buff *skb)
1816 {
1817 	struct sock *sk = skb->sk;
1818 
1819 	if (refcount_sub_and_test(skb->truesize, &sk->sk_wmem_alloc))
1820 		__sk_free(sk);
1821 }
1822 
1823 void skb_set_owner_w(struct sk_buff *skb, struct sock *sk)
1824 {
1825 	skb_orphan(skb);
1826 	skb->sk = sk;
1827 #ifdef CONFIG_INET
1828 	if (unlikely(!sk_fullsock(sk))) {
1829 		skb->destructor = sock_edemux;
1830 		sock_hold(sk);
1831 		return;
1832 	}
1833 #endif
1834 	skb->destructor = sock_wfree;
1835 	skb_set_hash_from_sk(skb, sk);
1836 	/*
1837 	 * We used to take a refcount on sk, but following operation
1838 	 * is enough to guarantee sk_free() wont free this sock until
1839 	 * all in-flight packets are completed
1840 	 */
1841 	refcount_add(skb->truesize, &sk->sk_wmem_alloc);
1842 }
1843 EXPORT_SYMBOL(skb_set_owner_w);
1844 
1845 /* This helper is used by netem, as it can hold packets in its
1846  * delay queue. We want to allow the owner socket to send more
1847  * packets, as if they were already TX completed by a typical driver.
1848  * But we also want to keep skb->sk set because some packet schedulers
1849  * rely on it (sch_fq for example).
1850  */
1851 void skb_orphan_partial(struct sk_buff *skb)
1852 {
1853 	if (skb_is_tcp_pure_ack(skb))
1854 		return;
1855 
1856 	if (skb->destructor == sock_wfree
1857 #ifdef CONFIG_INET
1858 	    || skb->destructor == tcp_wfree
1859 #endif
1860 		) {
1861 		struct sock *sk = skb->sk;
1862 
1863 		if (refcount_inc_not_zero(&sk->sk_refcnt)) {
1864 			WARN_ON(refcount_sub_and_test(skb->truesize, &sk->sk_wmem_alloc));
1865 			skb->destructor = sock_efree;
1866 		}
1867 	} else {
1868 		skb_orphan(skb);
1869 	}
1870 }
1871 EXPORT_SYMBOL(skb_orphan_partial);
1872 
1873 /*
1874  * Read buffer destructor automatically called from kfree_skb.
1875  */
1876 void sock_rfree(struct sk_buff *skb)
1877 {
1878 	struct sock *sk = skb->sk;
1879 	unsigned int len = skb->truesize;
1880 
1881 	atomic_sub(len, &sk->sk_rmem_alloc);
1882 	sk_mem_uncharge(sk, len);
1883 }
1884 EXPORT_SYMBOL(sock_rfree);
1885 
1886 /*
1887  * Buffer destructor for skbs that are not used directly in read or write
1888  * path, e.g. for error handler skbs. Automatically called from kfree_skb.
1889  */
1890 void sock_efree(struct sk_buff *skb)
1891 {
1892 	sock_put(skb->sk);
1893 }
1894 EXPORT_SYMBOL(sock_efree);
1895 
1896 kuid_t sock_i_uid(struct sock *sk)
1897 {
1898 	kuid_t uid;
1899 
1900 	read_lock_bh(&sk->sk_callback_lock);
1901 	uid = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_uid : GLOBAL_ROOT_UID;
1902 	read_unlock_bh(&sk->sk_callback_lock);
1903 	return uid;
1904 }
1905 EXPORT_SYMBOL(sock_i_uid);
1906 
1907 unsigned long sock_i_ino(struct sock *sk)
1908 {
1909 	unsigned long ino;
1910 
1911 	read_lock_bh(&sk->sk_callback_lock);
1912 	ino = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_ino : 0;
1913 	read_unlock_bh(&sk->sk_callback_lock);
1914 	return ino;
1915 }
1916 EXPORT_SYMBOL(sock_i_ino);
1917 
1918 /*
1919  * Allocate a skb from the socket's send buffer.
1920  */
1921 struct sk_buff *sock_wmalloc(struct sock *sk, unsigned long size, int force,
1922 			     gfp_t priority)
1923 {
1924 	if (force || refcount_read(&sk->sk_wmem_alloc) < sk->sk_sndbuf) {
1925 		struct sk_buff *skb = alloc_skb(size, priority);
1926 		if (skb) {
1927 			skb_set_owner_w(skb, sk);
1928 			return skb;
1929 		}
1930 	}
1931 	return NULL;
1932 }
1933 EXPORT_SYMBOL(sock_wmalloc);
1934 
1935 static void sock_ofree(struct sk_buff *skb)
1936 {
1937 	struct sock *sk = skb->sk;
1938 
1939 	atomic_sub(skb->truesize, &sk->sk_omem_alloc);
1940 }
1941 
1942 struct sk_buff *sock_omalloc(struct sock *sk, unsigned long size,
1943 			     gfp_t priority)
1944 {
1945 	struct sk_buff *skb;
1946 
1947 	/* small safe race: SKB_TRUESIZE may differ from final skb->truesize */
1948 	if (atomic_read(&sk->sk_omem_alloc) + SKB_TRUESIZE(size) >
1949 	    sysctl_optmem_max)
1950 		return NULL;
1951 
1952 	skb = alloc_skb(size, priority);
1953 	if (!skb)
1954 		return NULL;
1955 
1956 	atomic_add(skb->truesize, &sk->sk_omem_alloc);
1957 	skb->sk = sk;
1958 	skb->destructor = sock_ofree;
1959 	return skb;
1960 }
1961 
1962 /*
1963  * Allocate a memory block from the socket's option memory buffer.
1964  */
1965 void *sock_kmalloc(struct sock *sk, int size, gfp_t priority)
1966 {
1967 	if ((unsigned int)size <= sysctl_optmem_max &&
1968 	    atomic_read(&sk->sk_omem_alloc) + size < sysctl_optmem_max) {
1969 		void *mem;
1970 		/* First do the add, to avoid the race if kmalloc
1971 		 * might sleep.
1972 		 */
1973 		atomic_add(size, &sk->sk_omem_alloc);
1974 		mem = kmalloc(size, priority);
1975 		if (mem)
1976 			return mem;
1977 		atomic_sub(size, &sk->sk_omem_alloc);
1978 	}
1979 	return NULL;
1980 }
1981 EXPORT_SYMBOL(sock_kmalloc);
1982 
1983 /* Free an option memory block. Note, we actually want the inline
1984  * here as this allows gcc to detect the nullify and fold away the
1985  * condition entirely.
1986  */
1987 static inline void __sock_kfree_s(struct sock *sk, void *mem, int size,
1988 				  const bool nullify)
1989 {
1990 	if (WARN_ON_ONCE(!mem))
1991 		return;
1992 	if (nullify)
1993 		kzfree(mem);
1994 	else
1995 		kfree(mem);
1996 	atomic_sub(size, &sk->sk_omem_alloc);
1997 }
1998 
1999 void sock_kfree_s(struct sock *sk, void *mem, int size)
2000 {
2001 	__sock_kfree_s(sk, mem, size, false);
2002 }
2003 EXPORT_SYMBOL(sock_kfree_s);
2004 
2005 void sock_kzfree_s(struct sock *sk, void *mem, int size)
2006 {
2007 	__sock_kfree_s(sk, mem, size, true);
2008 }
2009 EXPORT_SYMBOL(sock_kzfree_s);
2010 
2011 /* It is almost wait_for_tcp_memory minus release_sock/lock_sock.
2012    I think, these locks should be removed for datagram sockets.
2013  */
2014 static long sock_wait_for_wmem(struct sock *sk, long timeo)
2015 {
2016 	DEFINE_WAIT(wait);
2017 
2018 	sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
2019 	for (;;) {
2020 		if (!timeo)
2021 			break;
2022 		if (signal_pending(current))
2023 			break;
2024 		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
2025 		prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
2026 		if (refcount_read(&sk->sk_wmem_alloc) < sk->sk_sndbuf)
2027 			break;
2028 		if (sk->sk_shutdown & SEND_SHUTDOWN)
2029 			break;
2030 		if (sk->sk_err)
2031 			break;
2032 		timeo = schedule_timeout(timeo);
2033 	}
2034 	finish_wait(sk_sleep(sk), &wait);
2035 	return timeo;
2036 }
2037 
2038 
2039 /*
2040  *	Generic send/receive buffer handlers
2041  */
2042 
2043 struct sk_buff *sock_alloc_send_pskb(struct sock *sk, unsigned long header_len,
2044 				     unsigned long data_len, int noblock,
2045 				     int *errcode, int max_page_order)
2046 {
2047 	struct sk_buff *skb;
2048 	long timeo;
2049 	int err;
2050 
2051 	timeo = sock_sndtimeo(sk, noblock);
2052 	for (;;) {
2053 		err = sock_error(sk);
2054 		if (err != 0)
2055 			goto failure;
2056 
2057 		err = -EPIPE;
2058 		if (sk->sk_shutdown & SEND_SHUTDOWN)
2059 			goto failure;
2060 
2061 		if (sk_wmem_alloc_get(sk) < sk->sk_sndbuf)
2062 			break;
2063 
2064 		sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
2065 		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
2066 		err = -EAGAIN;
2067 		if (!timeo)
2068 			goto failure;
2069 		if (signal_pending(current))
2070 			goto interrupted;
2071 		timeo = sock_wait_for_wmem(sk, timeo);
2072 	}
2073 	skb = alloc_skb_with_frags(header_len, data_len, max_page_order,
2074 				   errcode, sk->sk_allocation);
2075 	if (skb)
2076 		skb_set_owner_w(skb, sk);
2077 	return skb;
2078 
2079 interrupted:
2080 	err = sock_intr_errno(timeo);
2081 failure:
2082 	*errcode = err;
2083 	return NULL;
2084 }
2085 EXPORT_SYMBOL(sock_alloc_send_pskb);
2086 
2087 struct sk_buff *sock_alloc_send_skb(struct sock *sk, unsigned long size,
2088 				    int noblock, int *errcode)
2089 {
2090 	return sock_alloc_send_pskb(sk, size, 0, noblock, errcode, 0);
2091 }
2092 EXPORT_SYMBOL(sock_alloc_send_skb);
2093 
2094 int __sock_cmsg_send(struct sock *sk, struct msghdr *msg, struct cmsghdr *cmsg,
2095 		     struct sockcm_cookie *sockc)
2096 {
2097 	u32 tsflags;
2098 
2099 	switch (cmsg->cmsg_type) {
2100 	case SO_MARK:
2101 		if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
2102 			return -EPERM;
2103 		if (cmsg->cmsg_len != CMSG_LEN(sizeof(u32)))
2104 			return -EINVAL;
2105 		sockc->mark = *(u32 *)CMSG_DATA(cmsg);
2106 		break;
2107 	case SO_TIMESTAMPING:
2108 		if (cmsg->cmsg_len != CMSG_LEN(sizeof(u32)))
2109 			return -EINVAL;
2110 
2111 		tsflags = *(u32 *)CMSG_DATA(cmsg);
2112 		if (tsflags & ~SOF_TIMESTAMPING_TX_RECORD_MASK)
2113 			return -EINVAL;
2114 
2115 		sockc->tsflags &= ~SOF_TIMESTAMPING_TX_RECORD_MASK;
2116 		sockc->tsflags |= tsflags;
2117 		break;
2118 	/* SCM_RIGHTS and SCM_CREDENTIALS are semantically in SOL_UNIX. */
2119 	case SCM_RIGHTS:
2120 	case SCM_CREDENTIALS:
2121 		break;
2122 	default:
2123 		return -EINVAL;
2124 	}
2125 	return 0;
2126 }
2127 EXPORT_SYMBOL(__sock_cmsg_send);
2128 
2129 int sock_cmsg_send(struct sock *sk, struct msghdr *msg,
2130 		   struct sockcm_cookie *sockc)
2131 {
2132 	struct cmsghdr *cmsg;
2133 	int ret;
2134 
2135 	for_each_cmsghdr(cmsg, msg) {
2136 		if (!CMSG_OK(msg, cmsg))
2137 			return -EINVAL;
2138 		if (cmsg->cmsg_level != SOL_SOCKET)
2139 			continue;
2140 		ret = __sock_cmsg_send(sk, msg, cmsg, sockc);
2141 		if (ret)
2142 			return ret;
2143 	}
2144 	return 0;
2145 }
2146 EXPORT_SYMBOL(sock_cmsg_send);
2147 
2148 static void sk_enter_memory_pressure(struct sock *sk)
2149 {
2150 	if (!sk->sk_prot->enter_memory_pressure)
2151 		return;
2152 
2153 	sk->sk_prot->enter_memory_pressure(sk);
2154 }
2155 
2156 static void sk_leave_memory_pressure(struct sock *sk)
2157 {
2158 	if (sk->sk_prot->leave_memory_pressure) {
2159 		sk->sk_prot->leave_memory_pressure(sk);
2160 	} else {
2161 		unsigned long *memory_pressure = sk->sk_prot->memory_pressure;
2162 
2163 		if (memory_pressure && *memory_pressure)
2164 			*memory_pressure = 0;
2165 	}
2166 }
2167 
2168 /* On 32bit arches, an skb frag is limited to 2^15 */
2169 #define SKB_FRAG_PAGE_ORDER	get_order(32768)
2170 
2171 /**
2172  * skb_page_frag_refill - check that a page_frag contains enough room
2173  * @sz: minimum size of the fragment we want to get
2174  * @pfrag: pointer to page_frag
2175  * @gfp: priority for memory allocation
2176  *
2177  * Note: While this allocator tries to use high order pages, there is
2178  * no guarantee that allocations succeed. Therefore, @sz MUST be
2179  * less or equal than PAGE_SIZE.
2180  */
2181 bool skb_page_frag_refill(unsigned int sz, struct page_frag *pfrag, gfp_t gfp)
2182 {
2183 	if (pfrag->page) {
2184 		if (page_ref_count(pfrag->page) == 1) {
2185 			pfrag->offset = 0;
2186 			return true;
2187 		}
2188 		if (pfrag->offset + sz <= pfrag->size)
2189 			return true;
2190 		put_page(pfrag->page);
2191 	}
2192 
2193 	pfrag->offset = 0;
2194 	if (SKB_FRAG_PAGE_ORDER) {
2195 		/* Avoid direct reclaim but allow kswapd to wake */
2196 		pfrag->page = alloc_pages((gfp & ~__GFP_DIRECT_RECLAIM) |
2197 					  __GFP_COMP | __GFP_NOWARN |
2198 					  __GFP_NORETRY,
2199 					  SKB_FRAG_PAGE_ORDER);
2200 		if (likely(pfrag->page)) {
2201 			pfrag->size = PAGE_SIZE << SKB_FRAG_PAGE_ORDER;
2202 			return true;
2203 		}
2204 	}
2205 	pfrag->page = alloc_page(gfp);
2206 	if (likely(pfrag->page)) {
2207 		pfrag->size = PAGE_SIZE;
2208 		return true;
2209 	}
2210 	return false;
2211 }
2212 EXPORT_SYMBOL(skb_page_frag_refill);
2213 
2214 bool sk_page_frag_refill(struct sock *sk, struct page_frag *pfrag)
2215 {
2216 	if (likely(skb_page_frag_refill(32U, pfrag, sk->sk_allocation)))
2217 		return true;
2218 
2219 	sk_enter_memory_pressure(sk);
2220 	sk_stream_moderate_sndbuf(sk);
2221 	return false;
2222 }
2223 EXPORT_SYMBOL(sk_page_frag_refill);
2224 
2225 static void __lock_sock(struct sock *sk)
2226 	__releases(&sk->sk_lock.slock)
2227 	__acquires(&sk->sk_lock.slock)
2228 {
2229 	DEFINE_WAIT(wait);
2230 
2231 	for (;;) {
2232 		prepare_to_wait_exclusive(&sk->sk_lock.wq, &wait,
2233 					TASK_UNINTERRUPTIBLE);
2234 		spin_unlock_bh(&sk->sk_lock.slock);
2235 		schedule();
2236 		spin_lock_bh(&sk->sk_lock.slock);
2237 		if (!sock_owned_by_user(sk))
2238 			break;
2239 	}
2240 	finish_wait(&sk->sk_lock.wq, &wait);
2241 }
2242 
2243 static void __release_sock(struct sock *sk)
2244 	__releases(&sk->sk_lock.slock)
2245 	__acquires(&sk->sk_lock.slock)
2246 {
2247 	struct sk_buff *skb, *next;
2248 
2249 	while ((skb = sk->sk_backlog.head) != NULL) {
2250 		sk->sk_backlog.head = sk->sk_backlog.tail = NULL;
2251 
2252 		spin_unlock_bh(&sk->sk_lock.slock);
2253 
2254 		do {
2255 			next = skb->next;
2256 			prefetch(next);
2257 			WARN_ON_ONCE(skb_dst_is_noref(skb));
2258 			skb->next = NULL;
2259 			sk_backlog_rcv(sk, skb);
2260 
2261 			cond_resched();
2262 
2263 			skb = next;
2264 		} while (skb != NULL);
2265 
2266 		spin_lock_bh(&sk->sk_lock.slock);
2267 	}
2268 
2269 	/*
2270 	 * Doing the zeroing here guarantee we can not loop forever
2271 	 * while a wild producer attempts to flood us.
2272 	 */
2273 	sk->sk_backlog.len = 0;
2274 }
2275 
2276 void __sk_flush_backlog(struct sock *sk)
2277 {
2278 	spin_lock_bh(&sk->sk_lock.slock);
2279 	__release_sock(sk);
2280 	spin_unlock_bh(&sk->sk_lock.slock);
2281 }
2282 
2283 /**
2284  * sk_wait_data - wait for data to arrive at sk_receive_queue
2285  * @sk:    sock to wait on
2286  * @timeo: for how long
2287  * @skb:   last skb seen on sk_receive_queue
2288  *
2289  * Now socket state including sk->sk_err is changed only under lock,
2290  * hence we may omit checks after joining wait queue.
2291  * We check receive queue before schedule() only as optimization;
2292  * it is very likely that release_sock() added new data.
2293  */
2294 int sk_wait_data(struct sock *sk, long *timeo, const struct sk_buff *skb)
2295 {
2296 	DEFINE_WAIT_FUNC(wait, woken_wake_function);
2297 	int rc;
2298 
2299 	add_wait_queue(sk_sleep(sk), &wait);
2300 	sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
2301 	rc = sk_wait_event(sk, timeo, skb_peek_tail(&sk->sk_receive_queue) != skb, &wait);
2302 	sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
2303 	remove_wait_queue(sk_sleep(sk), &wait);
2304 	return rc;
2305 }
2306 EXPORT_SYMBOL(sk_wait_data);
2307 
2308 /**
2309  *	__sk_mem_raise_allocated - increase memory_allocated
2310  *	@sk: socket
2311  *	@size: memory size to allocate
2312  *	@amt: pages to allocate
2313  *	@kind: allocation type
2314  *
2315  *	Similar to __sk_mem_schedule(), but does not update sk_forward_alloc
2316  */
2317 int __sk_mem_raise_allocated(struct sock *sk, int size, int amt, int kind)
2318 {
2319 	struct proto *prot = sk->sk_prot;
2320 	long allocated = sk_memory_allocated_add(sk, amt);
2321 
2322 	if (mem_cgroup_sockets_enabled && sk->sk_memcg &&
2323 	    !mem_cgroup_charge_skmem(sk->sk_memcg, amt))
2324 		goto suppress_allocation;
2325 
2326 	/* Under limit. */
2327 	if (allocated <= sk_prot_mem_limits(sk, 0)) {
2328 		sk_leave_memory_pressure(sk);
2329 		return 1;
2330 	}
2331 
2332 	/* Under pressure. */
2333 	if (allocated > sk_prot_mem_limits(sk, 1))
2334 		sk_enter_memory_pressure(sk);
2335 
2336 	/* Over hard limit. */
2337 	if (allocated > sk_prot_mem_limits(sk, 2))
2338 		goto suppress_allocation;
2339 
2340 	/* guarantee minimum buffer size under pressure */
2341 	if (kind == SK_MEM_RECV) {
2342 		if (atomic_read(&sk->sk_rmem_alloc) < prot->sysctl_rmem[0])
2343 			return 1;
2344 
2345 	} else { /* SK_MEM_SEND */
2346 		if (sk->sk_type == SOCK_STREAM) {
2347 			if (sk->sk_wmem_queued < prot->sysctl_wmem[0])
2348 				return 1;
2349 		} else if (refcount_read(&sk->sk_wmem_alloc) <
2350 			   prot->sysctl_wmem[0])
2351 				return 1;
2352 	}
2353 
2354 	if (sk_has_memory_pressure(sk)) {
2355 		int alloc;
2356 
2357 		if (!sk_under_memory_pressure(sk))
2358 			return 1;
2359 		alloc = sk_sockets_allocated_read_positive(sk);
2360 		if (sk_prot_mem_limits(sk, 2) > alloc *
2361 		    sk_mem_pages(sk->sk_wmem_queued +
2362 				 atomic_read(&sk->sk_rmem_alloc) +
2363 				 sk->sk_forward_alloc))
2364 			return 1;
2365 	}
2366 
2367 suppress_allocation:
2368 
2369 	if (kind == SK_MEM_SEND && sk->sk_type == SOCK_STREAM) {
2370 		sk_stream_moderate_sndbuf(sk);
2371 
2372 		/* Fail only if socket is _under_ its sndbuf.
2373 		 * In this case we cannot block, so that we have to fail.
2374 		 */
2375 		if (sk->sk_wmem_queued + size >= sk->sk_sndbuf)
2376 			return 1;
2377 	}
2378 
2379 	trace_sock_exceed_buf_limit(sk, prot, allocated);
2380 
2381 	sk_memory_allocated_sub(sk, amt);
2382 
2383 	if (mem_cgroup_sockets_enabled && sk->sk_memcg)
2384 		mem_cgroup_uncharge_skmem(sk->sk_memcg, amt);
2385 
2386 	return 0;
2387 }
2388 EXPORT_SYMBOL(__sk_mem_raise_allocated);
2389 
2390 /**
2391  *	__sk_mem_schedule - increase sk_forward_alloc and memory_allocated
2392  *	@sk: socket
2393  *	@size: memory size to allocate
2394  *	@kind: allocation type
2395  *
2396  *	If kind is SK_MEM_SEND, it means wmem allocation. Otherwise it means
2397  *	rmem allocation. This function assumes that protocols which have
2398  *	memory_pressure use sk_wmem_queued as write buffer accounting.
2399  */
2400 int __sk_mem_schedule(struct sock *sk, int size, int kind)
2401 {
2402 	int ret, amt = sk_mem_pages(size);
2403 
2404 	sk->sk_forward_alloc += amt << SK_MEM_QUANTUM_SHIFT;
2405 	ret = __sk_mem_raise_allocated(sk, size, amt, kind);
2406 	if (!ret)
2407 		sk->sk_forward_alloc -= amt << SK_MEM_QUANTUM_SHIFT;
2408 	return ret;
2409 }
2410 EXPORT_SYMBOL(__sk_mem_schedule);
2411 
2412 /**
2413  *	__sk_mem_reduce_allocated - reclaim memory_allocated
2414  *	@sk: socket
2415  *	@amount: number of quanta
2416  *
2417  *	Similar to __sk_mem_reclaim(), but does not update sk_forward_alloc
2418  */
2419 void __sk_mem_reduce_allocated(struct sock *sk, int amount)
2420 {
2421 	sk_memory_allocated_sub(sk, amount);
2422 
2423 	if (mem_cgroup_sockets_enabled && sk->sk_memcg)
2424 		mem_cgroup_uncharge_skmem(sk->sk_memcg, amount);
2425 
2426 	if (sk_under_memory_pressure(sk) &&
2427 	    (sk_memory_allocated(sk) < sk_prot_mem_limits(sk, 0)))
2428 		sk_leave_memory_pressure(sk);
2429 }
2430 EXPORT_SYMBOL(__sk_mem_reduce_allocated);
2431 
2432 /**
2433  *	__sk_mem_reclaim - reclaim sk_forward_alloc and memory_allocated
2434  *	@sk: socket
2435  *	@amount: number of bytes (rounded down to a SK_MEM_QUANTUM multiple)
2436  */
2437 void __sk_mem_reclaim(struct sock *sk, int amount)
2438 {
2439 	amount >>= SK_MEM_QUANTUM_SHIFT;
2440 	sk->sk_forward_alloc -= amount << SK_MEM_QUANTUM_SHIFT;
2441 	__sk_mem_reduce_allocated(sk, amount);
2442 }
2443 EXPORT_SYMBOL(__sk_mem_reclaim);
2444 
2445 int sk_set_peek_off(struct sock *sk, int val)
2446 {
2447 	sk->sk_peek_off = val;
2448 	return 0;
2449 }
2450 EXPORT_SYMBOL_GPL(sk_set_peek_off);
2451 
2452 /*
2453  * Set of default routines for initialising struct proto_ops when
2454  * the protocol does not support a particular function. In certain
2455  * cases where it makes no sense for a protocol to have a "do nothing"
2456  * function, some default processing is provided.
2457  */
2458 
2459 int sock_no_bind(struct socket *sock, struct sockaddr *saddr, int len)
2460 {
2461 	return -EOPNOTSUPP;
2462 }
2463 EXPORT_SYMBOL(sock_no_bind);
2464 
2465 int sock_no_connect(struct socket *sock, struct sockaddr *saddr,
2466 		    int len, int flags)
2467 {
2468 	return -EOPNOTSUPP;
2469 }
2470 EXPORT_SYMBOL(sock_no_connect);
2471 
2472 int sock_no_socketpair(struct socket *sock1, struct socket *sock2)
2473 {
2474 	return -EOPNOTSUPP;
2475 }
2476 EXPORT_SYMBOL(sock_no_socketpair);
2477 
2478 int sock_no_accept(struct socket *sock, struct socket *newsock, int flags,
2479 		   bool kern)
2480 {
2481 	return -EOPNOTSUPP;
2482 }
2483 EXPORT_SYMBOL(sock_no_accept);
2484 
2485 int sock_no_getname(struct socket *sock, struct sockaddr *saddr,
2486 		    int *len, int peer)
2487 {
2488 	return -EOPNOTSUPP;
2489 }
2490 EXPORT_SYMBOL(sock_no_getname);
2491 
2492 unsigned int sock_no_poll(struct file *file, struct socket *sock, poll_table *pt)
2493 {
2494 	return 0;
2495 }
2496 EXPORT_SYMBOL(sock_no_poll);
2497 
2498 int sock_no_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
2499 {
2500 	return -EOPNOTSUPP;
2501 }
2502 EXPORT_SYMBOL(sock_no_ioctl);
2503 
2504 int sock_no_listen(struct socket *sock, int backlog)
2505 {
2506 	return -EOPNOTSUPP;
2507 }
2508 EXPORT_SYMBOL(sock_no_listen);
2509 
2510 int sock_no_shutdown(struct socket *sock, int how)
2511 {
2512 	return -EOPNOTSUPP;
2513 }
2514 EXPORT_SYMBOL(sock_no_shutdown);
2515 
2516 int sock_no_setsockopt(struct socket *sock, int level, int optname,
2517 		    char __user *optval, unsigned int optlen)
2518 {
2519 	return -EOPNOTSUPP;
2520 }
2521 EXPORT_SYMBOL(sock_no_setsockopt);
2522 
2523 int sock_no_getsockopt(struct socket *sock, int level, int optname,
2524 		    char __user *optval, int __user *optlen)
2525 {
2526 	return -EOPNOTSUPP;
2527 }
2528 EXPORT_SYMBOL(sock_no_getsockopt);
2529 
2530 int sock_no_sendmsg(struct socket *sock, struct msghdr *m, size_t len)
2531 {
2532 	return -EOPNOTSUPP;
2533 }
2534 EXPORT_SYMBOL(sock_no_sendmsg);
2535 
2536 int sock_no_sendmsg_locked(struct sock *sk, struct msghdr *m, size_t len)
2537 {
2538 	return -EOPNOTSUPP;
2539 }
2540 EXPORT_SYMBOL(sock_no_sendmsg_locked);
2541 
2542 int sock_no_recvmsg(struct socket *sock, struct msghdr *m, size_t len,
2543 		    int flags)
2544 {
2545 	return -EOPNOTSUPP;
2546 }
2547 EXPORT_SYMBOL(sock_no_recvmsg);
2548 
2549 int sock_no_mmap(struct file *file, struct socket *sock, struct vm_area_struct *vma)
2550 {
2551 	/* Mirror missing mmap method error code */
2552 	return -ENODEV;
2553 }
2554 EXPORT_SYMBOL(sock_no_mmap);
2555 
2556 ssize_t sock_no_sendpage(struct socket *sock, struct page *page, int offset, size_t size, int flags)
2557 {
2558 	ssize_t res;
2559 	struct msghdr msg = {.msg_flags = flags};
2560 	struct kvec iov;
2561 	char *kaddr = kmap(page);
2562 	iov.iov_base = kaddr + offset;
2563 	iov.iov_len = size;
2564 	res = kernel_sendmsg(sock, &msg, &iov, 1, size);
2565 	kunmap(page);
2566 	return res;
2567 }
2568 EXPORT_SYMBOL(sock_no_sendpage);
2569 
2570 ssize_t sock_no_sendpage_locked(struct sock *sk, struct page *page,
2571 				int offset, size_t size, int flags)
2572 {
2573 	ssize_t res;
2574 	struct msghdr msg = {.msg_flags = flags};
2575 	struct kvec iov;
2576 	char *kaddr = kmap(page);
2577 
2578 	iov.iov_base = kaddr + offset;
2579 	iov.iov_len = size;
2580 	res = kernel_sendmsg_locked(sk, &msg, &iov, 1, size);
2581 	kunmap(page);
2582 	return res;
2583 }
2584 EXPORT_SYMBOL(sock_no_sendpage_locked);
2585 
2586 /*
2587  *	Default Socket Callbacks
2588  */
2589 
2590 static void sock_def_wakeup(struct sock *sk)
2591 {
2592 	struct socket_wq *wq;
2593 
2594 	rcu_read_lock();
2595 	wq = rcu_dereference(sk->sk_wq);
2596 	if (skwq_has_sleeper(wq))
2597 		wake_up_interruptible_all(&wq->wait);
2598 	rcu_read_unlock();
2599 }
2600 
2601 static void sock_def_error_report(struct sock *sk)
2602 {
2603 	struct socket_wq *wq;
2604 
2605 	rcu_read_lock();
2606 	wq = rcu_dereference(sk->sk_wq);
2607 	if (skwq_has_sleeper(wq))
2608 		wake_up_interruptible_poll(&wq->wait, POLLERR);
2609 	sk_wake_async(sk, SOCK_WAKE_IO, POLL_ERR);
2610 	rcu_read_unlock();
2611 }
2612 
2613 static void sock_def_readable(struct sock *sk)
2614 {
2615 	struct socket_wq *wq;
2616 
2617 	rcu_read_lock();
2618 	wq = rcu_dereference(sk->sk_wq);
2619 	if (skwq_has_sleeper(wq))
2620 		wake_up_interruptible_sync_poll(&wq->wait, POLLIN | POLLPRI |
2621 						POLLRDNORM | POLLRDBAND);
2622 	sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
2623 	rcu_read_unlock();
2624 }
2625 
2626 static void sock_def_write_space(struct sock *sk)
2627 {
2628 	struct socket_wq *wq;
2629 
2630 	rcu_read_lock();
2631 
2632 	/* Do not wake up a writer until he can make "significant"
2633 	 * progress.  --DaveM
2634 	 */
2635 	if ((refcount_read(&sk->sk_wmem_alloc) << 1) <= sk->sk_sndbuf) {
2636 		wq = rcu_dereference(sk->sk_wq);
2637 		if (skwq_has_sleeper(wq))
2638 			wake_up_interruptible_sync_poll(&wq->wait, POLLOUT |
2639 						POLLWRNORM | POLLWRBAND);
2640 
2641 		/* Should agree with poll, otherwise some programs break */
2642 		if (sock_writeable(sk))
2643 			sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
2644 	}
2645 
2646 	rcu_read_unlock();
2647 }
2648 
2649 static void sock_def_destruct(struct sock *sk)
2650 {
2651 }
2652 
2653 void sk_send_sigurg(struct sock *sk)
2654 {
2655 	if (sk->sk_socket && sk->sk_socket->file)
2656 		if (send_sigurg(&sk->sk_socket->file->f_owner))
2657 			sk_wake_async(sk, SOCK_WAKE_URG, POLL_PRI);
2658 }
2659 EXPORT_SYMBOL(sk_send_sigurg);
2660 
2661 void sk_reset_timer(struct sock *sk, struct timer_list* timer,
2662 		    unsigned long expires)
2663 {
2664 	if (!mod_timer(timer, expires))
2665 		sock_hold(sk);
2666 }
2667 EXPORT_SYMBOL(sk_reset_timer);
2668 
2669 void sk_stop_timer(struct sock *sk, struct timer_list* timer)
2670 {
2671 	if (del_timer(timer))
2672 		__sock_put(sk);
2673 }
2674 EXPORT_SYMBOL(sk_stop_timer);
2675 
2676 void sock_init_data(struct socket *sock, struct sock *sk)
2677 {
2678 	sk_init_common(sk);
2679 	sk->sk_send_head	=	NULL;
2680 
2681 	init_timer(&sk->sk_timer);
2682 
2683 	sk->sk_allocation	=	GFP_KERNEL;
2684 	sk->sk_rcvbuf		=	sysctl_rmem_default;
2685 	sk->sk_sndbuf		=	sysctl_wmem_default;
2686 	sk->sk_state		=	TCP_CLOSE;
2687 	sk_set_socket(sk, sock);
2688 
2689 	sock_set_flag(sk, SOCK_ZAPPED);
2690 
2691 	if (sock) {
2692 		sk->sk_type	=	sock->type;
2693 		sk->sk_wq	=	sock->wq;
2694 		sock->sk	=	sk;
2695 		sk->sk_uid	=	SOCK_INODE(sock)->i_uid;
2696 	} else {
2697 		sk->sk_wq	=	NULL;
2698 		sk->sk_uid	=	make_kuid(sock_net(sk)->user_ns, 0);
2699 	}
2700 
2701 	rwlock_init(&sk->sk_callback_lock);
2702 	if (sk->sk_kern_sock)
2703 		lockdep_set_class_and_name(
2704 			&sk->sk_callback_lock,
2705 			af_kern_callback_keys + sk->sk_family,
2706 			af_family_kern_clock_key_strings[sk->sk_family]);
2707 	else
2708 		lockdep_set_class_and_name(
2709 			&sk->sk_callback_lock,
2710 			af_callback_keys + sk->sk_family,
2711 			af_family_clock_key_strings[sk->sk_family]);
2712 
2713 	sk->sk_state_change	=	sock_def_wakeup;
2714 	sk->sk_data_ready	=	sock_def_readable;
2715 	sk->sk_write_space	=	sock_def_write_space;
2716 	sk->sk_error_report	=	sock_def_error_report;
2717 	sk->sk_destruct		=	sock_def_destruct;
2718 
2719 	sk->sk_frag.page	=	NULL;
2720 	sk->sk_frag.offset	=	0;
2721 	sk->sk_peek_off		=	-1;
2722 
2723 	sk->sk_peer_pid 	=	NULL;
2724 	sk->sk_peer_cred	=	NULL;
2725 	sk->sk_write_pending	=	0;
2726 	sk->sk_rcvlowat		=	1;
2727 	sk->sk_rcvtimeo		=	MAX_SCHEDULE_TIMEOUT;
2728 	sk->sk_sndtimeo		=	MAX_SCHEDULE_TIMEOUT;
2729 
2730 	sk->sk_stamp = SK_DEFAULT_STAMP;
2731 	atomic_set(&sk->sk_zckey, 0);
2732 
2733 #ifdef CONFIG_NET_RX_BUSY_POLL
2734 	sk->sk_napi_id		=	0;
2735 	sk->sk_ll_usec		=	sysctl_net_busy_read;
2736 #endif
2737 
2738 	sk->sk_max_pacing_rate = ~0U;
2739 	sk->sk_pacing_rate = ~0U;
2740 	sk->sk_incoming_cpu = -1;
2741 	/*
2742 	 * Before updating sk_refcnt, we must commit prior changes to memory
2743 	 * (Documentation/RCU/rculist_nulls.txt for details)
2744 	 */
2745 	smp_wmb();
2746 	refcount_set(&sk->sk_refcnt, 1);
2747 	atomic_set(&sk->sk_drops, 0);
2748 }
2749 EXPORT_SYMBOL(sock_init_data);
2750 
2751 void lock_sock_nested(struct sock *sk, int subclass)
2752 {
2753 	might_sleep();
2754 	spin_lock_bh(&sk->sk_lock.slock);
2755 	if (sk->sk_lock.owned)
2756 		__lock_sock(sk);
2757 	sk->sk_lock.owned = 1;
2758 	spin_unlock(&sk->sk_lock.slock);
2759 	/*
2760 	 * The sk_lock has mutex_lock() semantics here:
2761 	 */
2762 	mutex_acquire(&sk->sk_lock.dep_map, subclass, 0, _RET_IP_);
2763 	local_bh_enable();
2764 }
2765 EXPORT_SYMBOL(lock_sock_nested);
2766 
2767 void release_sock(struct sock *sk)
2768 {
2769 	spin_lock_bh(&sk->sk_lock.slock);
2770 	if (sk->sk_backlog.tail)
2771 		__release_sock(sk);
2772 
2773 	/* Warning : release_cb() might need to release sk ownership,
2774 	 * ie call sock_release_ownership(sk) before us.
2775 	 */
2776 	if (sk->sk_prot->release_cb)
2777 		sk->sk_prot->release_cb(sk);
2778 
2779 	sock_release_ownership(sk);
2780 	if (waitqueue_active(&sk->sk_lock.wq))
2781 		wake_up(&sk->sk_lock.wq);
2782 	spin_unlock_bh(&sk->sk_lock.slock);
2783 }
2784 EXPORT_SYMBOL(release_sock);
2785 
2786 /**
2787  * lock_sock_fast - fast version of lock_sock
2788  * @sk: socket
2789  *
2790  * This version should be used for very small section, where process wont block
2791  * return false if fast path is taken:
2792  *
2793  *   sk_lock.slock locked, owned = 0, BH disabled
2794  *
2795  * return true if slow path is taken:
2796  *
2797  *   sk_lock.slock unlocked, owned = 1, BH enabled
2798  */
2799 bool lock_sock_fast(struct sock *sk)
2800 {
2801 	might_sleep();
2802 	spin_lock_bh(&sk->sk_lock.slock);
2803 
2804 	if (!sk->sk_lock.owned)
2805 		/*
2806 		 * Note : We must disable BH
2807 		 */
2808 		return false;
2809 
2810 	__lock_sock(sk);
2811 	sk->sk_lock.owned = 1;
2812 	spin_unlock(&sk->sk_lock.slock);
2813 	/*
2814 	 * The sk_lock has mutex_lock() semantics here:
2815 	 */
2816 	mutex_acquire(&sk->sk_lock.dep_map, 0, 0, _RET_IP_);
2817 	local_bh_enable();
2818 	return true;
2819 }
2820 EXPORT_SYMBOL(lock_sock_fast);
2821 
2822 int sock_get_timestamp(struct sock *sk, struct timeval __user *userstamp)
2823 {
2824 	struct timeval tv;
2825 	if (!sock_flag(sk, SOCK_TIMESTAMP))
2826 		sock_enable_timestamp(sk, SOCK_TIMESTAMP);
2827 	tv = ktime_to_timeval(sk->sk_stamp);
2828 	if (tv.tv_sec == -1)
2829 		return -ENOENT;
2830 	if (tv.tv_sec == 0) {
2831 		sk->sk_stamp = ktime_get_real();
2832 		tv = ktime_to_timeval(sk->sk_stamp);
2833 	}
2834 	return copy_to_user(userstamp, &tv, sizeof(tv)) ? -EFAULT : 0;
2835 }
2836 EXPORT_SYMBOL(sock_get_timestamp);
2837 
2838 int sock_get_timestampns(struct sock *sk, struct timespec __user *userstamp)
2839 {
2840 	struct timespec ts;
2841 	if (!sock_flag(sk, SOCK_TIMESTAMP))
2842 		sock_enable_timestamp(sk, SOCK_TIMESTAMP);
2843 	ts = ktime_to_timespec(sk->sk_stamp);
2844 	if (ts.tv_sec == -1)
2845 		return -ENOENT;
2846 	if (ts.tv_sec == 0) {
2847 		sk->sk_stamp = ktime_get_real();
2848 		ts = ktime_to_timespec(sk->sk_stamp);
2849 	}
2850 	return copy_to_user(userstamp, &ts, sizeof(ts)) ? -EFAULT : 0;
2851 }
2852 EXPORT_SYMBOL(sock_get_timestampns);
2853 
2854 void sock_enable_timestamp(struct sock *sk, int flag)
2855 {
2856 	if (!sock_flag(sk, flag)) {
2857 		unsigned long previous_flags = sk->sk_flags;
2858 
2859 		sock_set_flag(sk, flag);
2860 		/*
2861 		 * we just set one of the two flags which require net
2862 		 * time stamping, but time stamping might have been on
2863 		 * already because of the other one
2864 		 */
2865 		if (sock_needs_netstamp(sk) &&
2866 		    !(previous_flags & SK_FLAGS_TIMESTAMP))
2867 			net_enable_timestamp();
2868 	}
2869 }
2870 
2871 int sock_recv_errqueue(struct sock *sk, struct msghdr *msg, int len,
2872 		       int level, int type)
2873 {
2874 	struct sock_exterr_skb *serr;
2875 	struct sk_buff *skb;
2876 	int copied, err;
2877 
2878 	err = -EAGAIN;
2879 	skb = sock_dequeue_err_skb(sk);
2880 	if (skb == NULL)
2881 		goto out;
2882 
2883 	copied = skb->len;
2884 	if (copied > len) {
2885 		msg->msg_flags |= MSG_TRUNC;
2886 		copied = len;
2887 	}
2888 	err = skb_copy_datagram_msg(skb, 0, msg, copied);
2889 	if (err)
2890 		goto out_free_skb;
2891 
2892 	sock_recv_timestamp(msg, sk, skb);
2893 
2894 	serr = SKB_EXT_ERR(skb);
2895 	put_cmsg(msg, level, type, sizeof(serr->ee), &serr->ee);
2896 
2897 	msg->msg_flags |= MSG_ERRQUEUE;
2898 	err = copied;
2899 
2900 out_free_skb:
2901 	kfree_skb(skb);
2902 out:
2903 	return err;
2904 }
2905 EXPORT_SYMBOL(sock_recv_errqueue);
2906 
2907 /*
2908  *	Get a socket option on an socket.
2909  *
2910  *	FIX: POSIX 1003.1g is very ambiguous here. It states that
2911  *	asynchronous errors should be reported by getsockopt. We assume
2912  *	this means if you specify SO_ERROR (otherwise whats the point of it).
2913  */
2914 int sock_common_getsockopt(struct socket *sock, int level, int optname,
2915 			   char __user *optval, int __user *optlen)
2916 {
2917 	struct sock *sk = sock->sk;
2918 
2919 	return sk->sk_prot->getsockopt(sk, level, optname, optval, optlen);
2920 }
2921 EXPORT_SYMBOL(sock_common_getsockopt);
2922 
2923 #ifdef CONFIG_COMPAT
2924 int compat_sock_common_getsockopt(struct socket *sock, int level, int optname,
2925 				  char __user *optval, int __user *optlen)
2926 {
2927 	struct sock *sk = sock->sk;
2928 
2929 	if (sk->sk_prot->compat_getsockopt != NULL)
2930 		return sk->sk_prot->compat_getsockopt(sk, level, optname,
2931 						      optval, optlen);
2932 	return sk->sk_prot->getsockopt(sk, level, optname, optval, optlen);
2933 }
2934 EXPORT_SYMBOL(compat_sock_common_getsockopt);
2935 #endif
2936 
2937 int sock_common_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
2938 			int flags)
2939 {
2940 	struct sock *sk = sock->sk;
2941 	int addr_len = 0;
2942 	int err;
2943 
2944 	err = sk->sk_prot->recvmsg(sk, msg, size, flags & MSG_DONTWAIT,
2945 				   flags & ~MSG_DONTWAIT, &addr_len);
2946 	if (err >= 0)
2947 		msg->msg_namelen = addr_len;
2948 	return err;
2949 }
2950 EXPORT_SYMBOL(sock_common_recvmsg);
2951 
2952 /*
2953  *	Set socket options on an inet socket.
2954  */
2955 int sock_common_setsockopt(struct socket *sock, int level, int optname,
2956 			   char __user *optval, unsigned int optlen)
2957 {
2958 	struct sock *sk = sock->sk;
2959 
2960 	return sk->sk_prot->setsockopt(sk, level, optname, optval, optlen);
2961 }
2962 EXPORT_SYMBOL(sock_common_setsockopt);
2963 
2964 #ifdef CONFIG_COMPAT
2965 int compat_sock_common_setsockopt(struct socket *sock, int level, int optname,
2966 				  char __user *optval, unsigned int optlen)
2967 {
2968 	struct sock *sk = sock->sk;
2969 
2970 	if (sk->sk_prot->compat_setsockopt != NULL)
2971 		return sk->sk_prot->compat_setsockopt(sk, level, optname,
2972 						      optval, optlen);
2973 	return sk->sk_prot->setsockopt(sk, level, optname, optval, optlen);
2974 }
2975 EXPORT_SYMBOL(compat_sock_common_setsockopt);
2976 #endif
2977 
2978 void sk_common_release(struct sock *sk)
2979 {
2980 	if (sk->sk_prot->destroy)
2981 		sk->sk_prot->destroy(sk);
2982 
2983 	/*
2984 	 * Observation: when sock_common_release is called, processes have
2985 	 * no access to socket. But net still has.
2986 	 * Step one, detach it from networking:
2987 	 *
2988 	 * A. Remove from hash tables.
2989 	 */
2990 
2991 	sk->sk_prot->unhash(sk);
2992 
2993 	/*
2994 	 * In this point socket cannot receive new packets, but it is possible
2995 	 * that some packets are in flight because some CPU runs receiver and
2996 	 * did hash table lookup before we unhashed socket. They will achieve
2997 	 * receive queue and will be purged by socket destructor.
2998 	 *
2999 	 * Also we still have packets pending on receive queue and probably,
3000 	 * our own packets waiting in device queues. sock_destroy will drain
3001 	 * receive queue, but transmitted packets will delay socket destruction
3002 	 * until the last reference will be released.
3003 	 */
3004 
3005 	sock_orphan(sk);
3006 
3007 	xfrm_sk_free_policy(sk);
3008 
3009 	sk_refcnt_debug_release(sk);
3010 
3011 	sock_put(sk);
3012 }
3013 EXPORT_SYMBOL(sk_common_release);
3014 
3015 void sk_get_meminfo(const struct sock *sk, u32 *mem)
3016 {
3017 	memset(mem, 0, sizeof(*mem) * SK_MEMINFO_VARS);
3018 
3019 	mem[SK_MEMINFO_RMEM_ALLOC] = sk_rmem_alloc_get(sk);
3020 	mem[SK_MEMINFO_RCVBUF] = sk->sk_rcvbuf;
3021 	mem[SK_MEMINFO_WMEM_ALLOC] = sk_wmem_alloc_get(sk);
3022 	mem[SK_MEMINFO_SNDBUF] = sk->sk_sndbuf;
3023 	mem[SK_MEMINFO_FWD_ALLOC] = sk->sk_forward_alloc;
3024 	mem[SK_MEMINFO_WMEM_QUEUED] = sk->sk_wmem_queued;
3025 	mem[SK_MEMINFO_OPTMEM] = atomic_read(&sk->sk_omem_alloc);
3026 	mem[SK_MEMINFO_BACKLOG] = sk->sk_backlog.len;
3027 	mem[SK_MEMINFO_DROPS] = atomic_read(&sk->sk_drops);
3028 }
3029 
3030 #ifdef CONFIG_PROC_FS
3031 #define PROTO_INUSE_NR	64	/* should be enough for the first time */
3032 struct prot_inuse {
3033 	int val[PROTO_INUSE_NR];
3034 };
3035 
3036 static DECLARE_BITMAP(proto_inuse_idx, PROTO_INUSE_NR);
3037 
3038 #ifdef CONFIG_NET_NS
3039 void sock_prot_inuse_add(struct net *net, struct proto *prot, int val)
3040 {
3041 	__this_cpu_add(net->core.inuse->val[prot->inuse_idx], val);
3042 }
3043 EXPORT_SYMBOL_GPL(sock_prot_inuse_add);
3044 
3045 int sock_prot_inuse_get(struct net *net, struct proto *prot)
3046 {
3047 	int cpu, idx = prot->inuse_idx;
3048 	int res = 0;
3049 
3050 	for_each_possible_cpu(cpu)
3051 		res += per_cpu_ptr(net->core.inuse, cpu)->val[idx];
3052 
3053 	return res >= 0 ? res : 0;
3054 }
3055 EXPORT_SYMBOL_GPL(sock_prot_inuse_get);
3056 
3057 static int __net_init sock_inuse_init_net(struct net *net)
3058 {
3059 	net->core.inuse = alloc_percpu(struct prot_inuse);
3060 	return net->core.inuse ? 0 : -ENOMEM;
3061 }
3062 
3063 static void __net_exit sock_inuse_exit_net(struct net *net)
3064 {
3065 	free_percpu(net->core.inuse);
3066 }
3067 
3068 static struct pernet_operations net_inuse_ops = {
3069 	.init = sock_inuse_init_net,
3070 	.exit = sock_inuse_exit_net,
3071 };
3072 
3073 static __init int net_inuse_init(void)
3074 {
3075 	if (register_pernet_subsys(&net_inuse_ops))
3076 		panic("Cannot initialize net inuse counters");
3077 
3078 	return 0;
3079 }
3080 
3081 core_initcall(net_inuse_init);
3082 #else
3083 static DEFINE_PER_CPU(struct prot_inuse, prot_inuse);
3084 
3085 void sock_prot_inuse_add(struct net *net, struct proto *prot, int val)
3086 {
3087 	__this_cpu_add(prot_inuse.val[prot->inuse_idx], val);
3088 }
3089 EXPORT_SYMBOL_GPL(sock_prot_inuse_add);
3090 
3091 int sock_prot_inuse_get(struct net *net, struct proto *prot)
3092 {
3093 	int cpu, idx = prot->inuse_idx;
3094 	int res = 0;
3095 
3096 	for_each_possible_cpu(cpu)
3097 		res += per_cpu(prot_inuse, cpu).val[idx];
3098 
3099 	return res >= 0 ? res : 0;
3100 }
3101 EXPORT_SYMBOL_GPL(sock_prot_inuse_get);
3102 #endif
3103 
3104 static void assign_proto_idx(struct proto *prot)
3105 {
3106 	prot->inuse_idx = find_first_zero_bit(proto_inuse_idx, PROTO_INUSE_NR);
3107 
3108 	if (unlikely(prot->inuse_idx == PROTO_INUSE_NR - 1)) {
3109 		pr_err("PROTO_INUSE_NR exhausted\n");
3110 		return;
3111 	}
3112 
3113 	set_bit(prot->inuse_idx, proto_inuse_idx);
3114 }
3115 
3116 static void release_proto_idx(struct proto *prot)
3117 {
3118 	if (prot->inuse_idx != PROTO_INUSE_NR - 1)
3119 		clear_bit(prot->inuse_idx, proto_inuse_idx);
3120 }
3121 #else
3122 static inline void assign_proto_idx(struct proto *prot)
3123 {
3124 }
3125 
3126 static inline void release_proto_idx(struct proto *prot)
3127 {
3128 }
3129 #endif
3130 
3131 static void req_prot_cleanup(struct request_sock_ops *rsk_prot)
3132 {
3133 	if (!rsk_prot)
3134 		return;
3135 	kfree(rsk_prot->slab_name);
3136 	rsk_prot->slab_name = NULL;
3137 	kmem_cache_destroy(rsk_prot->slab);
3138 	rsk_prot->slab = NULL;
3139 }
3140 
3141 static int req_prot_init(const struct proto *prot)
3142 {
3143 	struct request_sock_ops *rsk_prot = prot->rsk_prot;
3144 
3145 	if (!rsk_prot)
3146 		return 0;
3147 
3148 	rsk_prot->slab_name = kasprintf(GFP_KERNEL, "request_sock_%s",
3149 					prot->name);
3150 	if (!rsk_prot->slab_name)
3151 		return -ENOMEM;
3152 
3153 	rsk_prot->slab = kmem_cache_create(rsk_prot->slab_name,
3154 					   rsk_prot->obj_size, 0,
3155 					   prot->slab_flags, NULL);
3156 
3157 	if (!rsk_prot->slab) {
3158 		pr_crit("%s: Can't create request sock SLAB cache!\n",
3159 			prot->name);
3160 		return -ENOMEM;
3161 	}
3162 	return 0;
3163 }
3164 
3165 int proto_register(struct proto *prot, int alloc_slab)
3166 {
3167 	if (alloc_slab) {
3168 		prot->slab = kmem_cache_create(prot->name, prot->obj_size, 0,
3169 					SLAB_HWCACHE_ALIGN | prot->slab_flags,
3170 					NULL);
3171 
3172 		if (prot->slab == NULL) {
3173 			pr_crit("%s: Can't create sock SLAB cache!\n",
3174 				prot->name);
3175 			goto out;
3176 		}
3177 
3178 		if (req_prot_init(prot))
3179 			goto out_free_request_sock_slab;
3180 
3181 		if (prot->twsk_prot != NULL) {
3182 			prot->twsk_prot->twsk_slab_name = kasprintf(GFP_KERNEL, "tw_sock_%s", prot->name);
3183 
3184 			if (prot->twsk_prot->twsk_slab_name == NULL)
3185 				goto out_free_request_sock_slab;
3186 
3187 			prot->twsk_prot->twsk_slab =
3188 				kmem_cache_create(prot->twsk_prot->twsk_slab_name,
3189 						  prot->twsk_prot->twsk_obj_size,
3190 						  0,
3191 						  prot->slab_flags,
3192 						  NULL);
3193 			if (prot->twsk_prot->twsk_slab == NULL)
3194 				goto out_free_timewait_sock_slab_name;
3195 		}
3196 	}
3197 
3198 	mutex_lock(&proto_list_mutex);
3199 	list_add(&prot->node, &proto_list);
3200 	assign_proto_idx(prot);
3201 	mutex_unlock(&proto_list_mutex);
3202 	return 0;
3203 
3204 out_free_timewait_sock_slab_name:
3205 	kfree(prot->twsk_prot->twsk_slab_name);
3206 out_free_request_sock_slab:
3207 	req_prot_cleanup(prot->rsk_prot);
3208 
3209 	kmem_cache_destroy(prot->slab);
3210 	prot->slab = NULL;
3211 out:
3212 	return -ENOBUFS;
3213 }
3214 EXPORT_SYMBOL(proto_register);
3215 
3216 void proto_unregister(struct proto *prot)
3217 {
3218 	mutex_lock(&proto_list_mutex);
3219 	release_proto_idx(prot);
3220 	list_del(&prot->node);
3221 	mutex_unlock(&proto_list_mutex);
3222 
3223 	kmem_cache_destroy(prot->slab);
3224 	prot->slab = NULL;
3225 
3226 	req_prot_cleanup(prot->rsk_prot);
3227 
3228 	if (prot->twsk_prot != NULL && prot->twsk_prot->twsk_slab != NULL) {
3229 		kmem_cache_destroy(prot->twsk_prot->twsk_slab);
3230 		kfree(prot->twsk_prot->twsk_slab_name);
3231 		prot->twsk_prot->twsk_slab = NULL;
3232 	}
3233 }
3234 EXPORT_SYMBOL(proto_unregister);
3235 
3236 #ifdef CONFIG_PROC_FS
3237 static void *proto_seq_start(struct seq_file *seq, loff_t *pos)
3238 	__acquires(proto_list_mutex)
3239 {
3240 	mutex_lock(&proto_list_mutex);
3241 	return seq_list_start_head(&proto_list, *pos);
3242 }
3243 
3244 static void *proto_seq_next(struct seq_file *seq, void *v, loff_t *pos)
3245 {
3246 	return seq_list_next(v, &proto_list, pos);
3247 }
3248 
3249 static void proto_seq_stop(struct seq_file *seq, void *v)
3250 	__releases(proto_list_mutex)
3251 {
3252 	mutex_unlock(&proto_list_mutex);
3253 }
3254 
3255 static char proto_method_implemented(const void *method)
3256 {
3257 	return method == NULL ? 'n' : 'y';
3258 }
3259 static long sock_prot_memory_allocated(struct proto *proto)
3260 {
3261 	return proto->memory_allocated != NULL ? proto_memory_allocated(proto) : -1L;
3262 }
3263 
3264 static char *sock_prot_memory_pressure(struct proto *proto)
3265 {
3266 	return proto->memory_pressure != NULL ?
3267 	proto_memory_pressure(proto) ? "yes" : "no" : "NI";
3268 }
3269 
3270 static void proto_seq_printf(struct seq_file *seq, struct proto *proto)
3271 {
3272 
3273 	seq_printf(seq, "%-9s %4u %6d  %6ld   %-3s %6u   %-3s  %-10s "
3274 			"%2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c\n",
3275 		   proto->name,
3276 		   proto->obj_size,
3277 		   sock_prot_inuse_get(seq_file_net(seq), proto),
3278 		   sock_prot_memory_allocated(proto),
3279 		   sock_prot_memory_pressure(proto),
3280 		   proto->max_header,
3281 		   proto->slab == NULL ? "no" : "yes",
3282 		   module_name(proto->owner),
3283 		   proto_method_implemented(proto->close),
3284 		   proto_method_implemented(proto->connect),
3285 		   proto_method_implemented(proto->disconnect),
3286 		   proto_method_implemented(proto->accept),
3287 		   proto_method_implemented(proto->ioctl),
3288 		   proto_method_implemented(proto->init),
3289 		   proto_method_implemented(proto->destroy),
3290 		   proto_method_implemented(proto->shutdown),
3291 		   proto_method_implemented(proto->setsockopt),
3292 		   proto_method_implemented(proto->getsockopt),
3293 		   proto_method_implemented(proto->sendmsg),
3294 		   proto_method_implemented(proto->recvmsg),
3295 		   proto_method_implemented(proto->sendpage),
3296 		   proto_method_implemented(proto->bind),
3297 		   proto_method_implemented(proto->backlog_rcv),
3298 		   proto_method_implemented(proto->hash),
3299 		   proto_method_implemented(proto->unhash),
3300 		   proto_method_implemented(proto->get_port),
3301 		   proto_method_implemented(proto->enter_memory_pressure));
3302 }
3303 
3304 static int proto_seq_show(struct seq_file *seq, void *v)
3305 {
3306 	if (v == &proto_list)
3307 		seq_printf(seq, "%-9s %-4s %-8s %-6s %-5s %-7s %-4s %-10s %s",
3308 			   "protocol",
3309 			   "size",
3310 			   "sockets",
3311 			   "memory",
3312 			   "press",
3313 			   "maxhdr",
3314 			   "slab",
3315 			   "module",
3316 			   "cl co di ac io in de sh ss gs se re sp bi br ha uh gp em\n");
3317 	else
3318 		proto_seq_printf(seq, list_entry(v, struct proto, node));
3319 	return 0;
3320 }
3321 
3322 static const struct seq_operations proto_seq_ops = {
3323 	.start  = proto_seq_start,
3324 	.next   = proto_seq_next,
3325 	.stop   = proto_seq_stop,
3326 	.show   = proto_seq_show,
3327 };
3328 
3329 static int proto_seq_open(struct inode *inode, struct file *file)
3330 {
3331 	return seq_open_net(inode, file, &proto_seq_ops,
3332 			    sizeof(struct seq_net_private));
3333 }
3334 
3335 static const struct file_operations proto_seq_fops = {
3336 	.owner		= THIS_MODULE,
3337 	.open		= proto_seq_open,
3338 	.read		= seq_read,
3339 	.llseek		= seq_lseek,
3340 	.release	= seq_release_net,
3341 };
3342 
3343 static __net_init int proto_init_net(struct net *net)
3344 {
3345 	if (!proc_create("protocols", S_IRUGO, net->proc_net, &proto_seq_fops))
3346 		return -ENOMEM;
3347 
3348 	return 0;
3349 }
3350 
3351 static __net_exit void proto_exit_net(struct net *net)
3352 {
3353 	remove_proc_entry("protocols", net->proc_net);
3354 }
3355 
3356 
3357 static __net_initdata struct pernet_operations proto_net_ops = {
3358 	.init = proto_init_net,
3359 	.exit = proto_exit_net,
3360 };
3361 
3362 static int __init proto_init(void)
3363 {
3364 	return register_pernet_subsys(&proto_net_ops);
3365 }
3366 
3367 subsys_initcall(proto_init);
3368 
3369 #endif /* PROC_FS */
3370 
3371 #ifdef CONFIG_NET_RX_BUSY_POLL
3372 bool sk_busy_loop_end(void *p, unsigned long start_time)
3373 {
3374 	struct sock *sk = p;
3375 
3376 	return !skb_queue_empty(&sk->sk_receive_queue) ||
3377 	       sk_busy_loop_timeout(sk, start_time);
3378 }
3379 EXPORT_SYMBOL(sk_busy_loop_end);
3380 #endif /* CONFIG_NET_RX_BUSY_POLL */
3381