xref: /openbmc/linux/net/core/sock.c (revision a48c7709)
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 static void sock_inuse_add(struct net *net, int val);
149 
150 /**
151  * sk_ns_capable - General socket capability test
152  * @sk: Socket to use a capability on or through
153  * @user_ns: The user namespace of the capability to use
154  * @cap: The capability to use
155  *
156  * Test to see if the opener of the socket had when the socket was
157  * created and the current process has the capability @cap in the user
158  * namespace @user_ns.
159  */
160 bool sk_ns_capable(const struct sock *sk,
161 		   struct user_namespace *user_ns, int cap)
162 {
163 	return file_ns_capable(sk->sk_socket->file, user_ns, cap) &&
164 		ns_capable(user_ns, cap);
165 }
166 EXPORT_SYMBOL(sk_ns_capable);
167 
168 /**
169  * sk_capable - Socket global capability test
170  * @sk: Socket to use a capability on or through
171  * @cap: The global capability to use
172  *
173  * Test to see if the opener of the socket had when the socket was
174  * created and the current process has the capability @cap in all user
175  * namespaces.
176  */
177 bool sk_capable(const struct sock *sk, int cap)
178 {
179 	return sk_ns_capable(sk, &init_user_ns, cap);
180 }
181 EXPORT_SYMBOL(sk_capable);
182 
183 /**
184  * sk_net_capable - Network namespace socket capability test
185  * @sk: Socket to use a capability on or through
186  * @cap: The capability to use
187  *
188  * Test to see if the opener of the socket had when the socket was created
189  * and the current process has the capability @cap over the network namespace
190  * the socket is a member of.
191  */
192 bool sk_net_capable(const struct sock *sk, int cap)
193 {
194 	return sk_ns_capable(sk, sock_net(sk)->user_ns, cap);
195 }
196 EXPORT_SYMBOL(sk_net_capable);
197 
198 /*
199  * Each address family might have different locking rules, so we have
200  * one slock key per address family and separate keys for internal and
201  * userspace sockets.
202  */
203 static struct lock_class_key af_family_keys[AF_MAX];
204 static struct lock_class_key af_family_kern_keys[AF_MAX];
205 static struct lock_class_key af_family_slock_keys[AF_MAX];
206 static struct lock_class_key af_family_kern_slock_keys[AF_MAX];
207 
208 /*
209  * Make lock validator output more readable. (we pre-construct these
210  * strings build-time, so that runtime initialization of socket
211  * locks is fast):
212  */
213 
214 #define _sock_locks(x)						  \
215   x "AF_UNSPEC",	x "AF_UNIX"     ,	x "AF_INET"     , \
216   x "AF_AX25"  ,	x "AF_IPX"      ,	x "AF_APPLETALK", \
217   x "AF_NETROM",	x "AF_BRIDGE"   ,	x "AF_ATMPVC"   , \
218   x "AF_X25"   ,	x "AF_INET6"    ,	x "AF_ROSE"     , \
219   x "AF_DECnet",	x "AF_NETBEUI"  ,	x "AF_SECURITY" , \
220   x "AF_KEY"   ,	x "AF_NETLINK"  ,	x "AF_PACKET"   , \
221   x "AF_ASH"   ,	x "AF_ECONET"   ,	x "AF_ATMSVC"   , \
222   x "AF_RDS"   ,	x "AF_SNA"      ,	x "AF_IRDA"     , \
223   x "AF_PPPOX" ,	x "AF_WANPIPE"  ,	x "AF_LLC"      , \
224   x "27"       ,	x "28"          ,	x "AF_CAN"      , \
225   x "AF_TIPC"  ,	x "AF_BLUETOOTH",	x "IUCV"        , \
226   x "AF_RXRPC" ,	x "AF_ISDN"     ,	x "AF_PHONET"   , \
227   x "AF_IEEE802154",	x "AF_CAIF"	,	x "AF_ALG"      , \
228   x "AF_NFC"   ,	x "AF_VSOCK"    ,	x "AF_KCM"      , \
229   x "AF_QIPCRTR",	x "AF_SMC"	,	x "AF_MAX"
230 
231 static const char *const af_family_key_strings[AF_MAX+1] = {
232 	_sock_locks("sk_lock-")
233 };
234 static const char *const af_family_slock_key_strings[AF_MAX+1] = {
235 	_sock_locks("slock-")
236 };
237 static const char *const af_family_clock_key_strings[AF_MAX+1] = {
238 	_sock_locks("clock-")
239 };
240 
241 static const char *const af_family_kern_key_strings[AF_MAX+1] = {
242 	_sock_locks("k-sk_lock-")
243 };
244 static const char *const af_family_kern_slock_key_strings[AF_MAX+1] = {
245 	_sock_locks("k-slock-")
246 };
247 static const char *const af_family_kern_clock_key_strings[AF_MAX+1] = {
248 	_sock_locks("k-clock-")
249 };
250 static const char *const af_family_rlock_key_strings[AF_MAX+1] = {
251   "rlock-AF_UNSPEC", "rlock-AF_UNIX"     , "rlock-AF_INET"     ,
252   "rlock-AF_AX25"  , "rlock-AF_IPX"      , "rlock-AF_APPLETALK",
253   "rlock-AF_NETROM", "rlock-AF_BRIDGE"   , "rlock-AF_ATMPVC"   ,
254   "rlock-AF_X25"   , "rlock-AF_INET6"    , "rlock-AF_ROSE"     ,
255   "rlock-AF_DECnet", "rlock-AF_NETBEUI"  , "rlock-AF_SECURITY" ,
256   "rlock-AF_KEY"   , "rlock-AF_NETLINK"  , "rlock-AF_PACKET"   ,
257   "rlock-AF_ASH"   , "rlock-AF_ECONET"   , "rlock-AF_ATMSVC"   ,
258   "rlock-AF_RDS"   , "rlock-AF_SNA"      , "rlock-AF_IRDA"     ,
259   "rlock-AF_PPPOX" , "rlock-AF_WANPIPE"  , "rlock-AF_LLC"      ,
260   "rlock-27"       , "rlock-28"          , "rlock-AF_CAN"      ,
261   "rlock-AF_TIPC"  , "rlock-AF_BLUETOOTH", "rlock-AF_IUCV"     ,
262   "rlock-AF_RXRPC" , "rlock-AF_ISDN"     , "rlock-AF_PHONET"   ,
263   "rlock-AF_IEEE802154", "rlock-AF_CAIF" , "rlock-AF_ALG"      ,
264   "rlock-AF_NFC"   , "rlock-AF_VSOCK"    , "rlock-AF_KCM"      ,
265   "rlock-AF_QIPCRTR", "rlock-AF_SMC"     , "rlock-AF_MAX"
266 };
267 static const char *const af_family_wlock_key_strings[AF_MAX+1] = {
268   "wlock-AF_UNSPEC", "wlock-AF_UNIX"     , "wlock-AF_INET"     ,
269   "wlock-AF_AX25"  , "wlock-AF_IPX"      , "wlock-AF_APPLETALK",
270   "wlock-AF_NETROM", "wlock-AF_BRIDGE"   , "wlock-AF_ATMPVC"   ,
271   "wlock-AF_X25"   , "wlock-AF_INET6"    , "wlock-AF_ROSE"     ,
272   "wlock-AF_DECnet", "wlock-AF_NETBEUI"  , "wlock-AF_SECURITY" ,
273   "wlock-AF_KEY"   , "wlock-AF_NETLINK"  , "wlock-AF_PACKET"   ,
274   "wlock-AF_ASH"   , "wlock-AF_ECONET"   , "wlock-AF_ATMSVC"   ,
275   "wlock-AF_RDS"   , "wlock-AF_SNA"      , "wlock-AF_IRDA"     ,
276   "wlock-AF_PPPOX" , "wlock-AF_WANPIPE"  , "wlock-AF_LLC"      ,
277   "wlock-27"       , "wlock-28"          , "wlock-AF_CAN"      ,
278   "wlock-AF_TIPC"  , "wlock-AF_BLUETOOTH", "wlock-AF_IUCV"     ,
279   "wlock-AF_RXRPC" , "wlock-AF_ISDN"     , "wlock-AF_PHONET"   ,
280   "wlock-AF_IEEE802154", "wlock-AF_CAIF" , "wlock-AF_ALG"      ,
281   "wlock-AF_NFC"   , "wlock-AF_VSOCK"    , "wlock-AF_KCM"      ,
282   "wlock-AF_QIPCRTR", "wlock-AF_SMC"     , "wlock-AF_MAX"
283 };
284 static const char *const af_family_elock_key_strings[AF_MAX+1] = {
285   "elock-AF_UNSPEC", "elock-AF_UNIX"     , "elock-AF_INET"     ,
286   "elock-AF_AX25"  , "elock-AF_IPX"      , "elock-AF_APPLETALK",
287   "elock-AF_NETROM", "elock-AF_BRIDGE"   , "elock-AF_ATMPVC"   ,
288   "elock-AF_X25"   , "elock-AF_INET6"    , "elock-AF_ROSE"     ,
289   "elock-AF_DECnet", "elock-AF_NETBEUI"  , "elock-AF_SECURITY" ,
290   "elock-AF_KEY"   , "elock-AF_NETLINK"  , "elock-AF_PACKET"   ,
291   "elock-AF_ASH"   , "elock-AF_ECONET"   , "elock-AF_ATMSVC"   ,
292   "elock-AF_RDS"   , "elock-AF_SNA"      , "elock-AF_IRDA"     ,
293   "elock-AF_PPPOX" , "elock-AF_WANPIPE"  , "elock-AF_LLC"      ,
294   "elock-27"       , "elock-28"          , "elock-AF_CAN"      ,
295   "elock-AF_TIPC"  , "elock-AF_BLUETOOTH", "elock-AF_IUCV"     ,
296   "elock-AF_RXRPC" , "elock-AF_ISDN"     , "elock-AF_PHONET"   ,
297   "elock-AF_IEEE802154", "elock-AF_CAIF" , "elock-AF_ALG"      ,
298   "elock-AF_NFC"   , "elock-AF_VSOCK"    , "elock-AF_KCM"      ,
299   "elock-AF_QIPCRTR", "elock-AF_SMC"     , "elock-AF_MAX"
300 };
301 
302 /*
303  * sk_callback_lock and sk queues locking rules are per-address-family,
304  * so split the lock classes by using a per-AF key:
305  */
306 static struct lock_class_key af_callback_keys[AF_MAX];
307 static struct lock_class_key af_rlock_keys[AF_MAX];
308 static struct lock_class_key af_wlock_keys[AF_MAX];
309 static struct lock_class_key af_elock_keys[AF_MAX];
310 static struct lock_class_key af_kern_callback_keys[AF_MAX];
311 
312 /* Run time adjustable parameters. */
313 __u32 sysctl_wmem_max __read_mostly = SK_WMEM_MAX;
314 EXPORT_SYMBOL(sysctl_wmem_max);
315 __u32 sysctl_rmem_max __read_mostly = SK_RMEM_MAX;
316 EXPORT_SYMBOL(sysctl_rmem_max);
317 __u32 sysctl_wmem_default __read_mostly = SK_WMEM_MAX;
318 __u32 sysctl_rmem_default __read_mostly = SK_RMEM_MAX;
319 
320 /* Maximal space eaten by iovec or ancillary data plus some space */
321 int sysctl_optmem_max __read_mostly = sizeof(unsigned long)*(2*UIO_MAXIOV+512);
322 EXPORT_SYMBOL(sysctl_optmem_max);
323 
324 int sysctl_tstamp_allow_data __read_mostly = 1;
325 
326 struct static_key memalloc_socks = STATIC_KEY_INIT_FALSE;
327 EXPORT_SYMBOL_GPL(memalloc_socks);
328 
329 /**
330  * sk_set_memalloc - sets %SOCK_MEMALLOC
331  * @sk: socket to set it on
332  *
333  * Set %SOCK_MEMALLOC on a socket for access to emergency reserves.
334  * It's the responsibility of the admin to adjust min_free_kbytes
335  * to meet the requirements
336  */
337 void sk_set_memalloc(struct sock *sk)
338 {
339 	sock_set_flag(sk, SOCK_MEMALLOC);
340 	sk->sk_allocation |= __GFP_MEMALLOC;
341 	static_key_slow_inc(&memalloc_socks);
342 }
343 EXPORT_SYMBOL_GPL(sk_set_memalloc);
344 
345 void sk_clear_memalloc(struct sock *sk)
346 {
347 	sock_reset_flag(sk, SOCK_MEMALLOC);
348 	sk->sk_allocation &= ~__GFP_MEMALLOC;
349 	static_key_slow_dec(&memalloc_socks);
350 
351 	/*
352 	 * SOCK_MEMALLOC is allowed to ignore rmem limits to ensure forward
353 	 * progress of swapping. SOCK_MEMALLOC may be cleared while
354 	 * it has rmem allocations due to the last swapfile being deactivated
355 	 * but there is a risk that the socket is unusable due to exceeding
356 	 * the rmem limits. Reclaim the reserves and obey rmem limits again.
357 	 */
358 	sk_mem_reclaim(sk);
359 }
360 EXPORT_SYMBOL_GPL(sk_clear_memalloc);
361 
362 int __sk_backlog_rcv(struct sock *sk, struct sk_buff *skb)
363 {
364 	int ret;
365 	unsigned int noreclaim_flag;
366 
367 	/* these should have been dropped before queueing */
368 	BUG_ON(!sock_flag(sk, SOCK_MEMALLOC));
369 
370 	noreclaim_flag = memalloc_noreclaim_save();
371 	ret = sk->sk_backlog_rcv(sk, skb);
372 	memalloc_noreclaim_restore(noreclaim_flag);
373 
374 	return ret;
375 }
376 EXPORT_SYMBOL(__sk_backlog_rcv);
377 
378 static int sock_set_timeout(long *timeo_p, char __user *optval, int optlen)
379 {
380 	struct timeval tv;
381 
382 	if (optlen < sizeof(tv))
383 		return -EINVAL;
384 	if (copy_from_user(&tv, optval, sizeof(tv)))
385 		return -EFAULT;
386 	if (tv.tv_usec < 0 || tv.tv_usec >= USEC_PER_SEC)
387 		return -EDOM;
388 
389 	if (tv.tv_sec < 0) {
390 		static int warned __read_mostly;
391 
392 		*timeo_p = 0;
393 		if (warned < 10 && net_ratelimit()) {
394 			warned++;
395 			pr_info("%s: `%s' (pid %d) tries to set negative timeout\n",
396 				__func__, current->comm, task_pid_nr(current));
397 		}
398 		return 0;
399 	}
400 	*timeo_p = MAX_SCHEDULE_TIMEOUT;
401 	if (tv.tv_sec == 0 && tv.tv_usec == 0)
402 		return 0;
403 	if (tv.tv_sec < (MAX_SCHEDULE_TIMEOUT/HZ - 1))
404 		*timeo_p = tv.tv_sec * HZ + DIV_ROUND_UP(tv.tv_usec, USEC_PER_SEC / HZ);
405 	return 0;
406 }
407 
408 static void sock_warn_obsolete_bsdism(const char *name)
409 {
410 	static int warned;
411 	static char warncomm[TASK_COMM_LEN];
412 	if (strcmp(warncomm, current->comm) && warned < 5) {
413 		strcpy(warncomm,  current->comm);
414 		pr_warn("process `%s' is using obsolete %s SO_BSDCOMPAT\n",
415 			warncomm, name);
416 		warned++;
417 	}
418 }
419 
420 static bool sock_needs_netstamp(const struct sock *sk)
421 {
422 	switch (sk->sk_family) {
423 	case AF_UNSPEC:
424 	case AF_UNIX:
425 		return false;
426 	default:
427 		return true;
428 	}
429 }
430 
431 static void sock_disable_timestamp(struct sock *sk, unsigned long flags)
432 {
433 	if (sk->sk_flags & flags) {
434 		sk->sk_flags &= ~flags;
435 		if (sock_needs_netstamp(sk) &&
436 		    !(sk->sk_flags & SK_FLAGS_TIMESTAMP))
437 			net_disable_timestamp();
438 	}
439 }
440 
441 
442 int __sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
443 {
444 	unsigned long flags;
445 	struct sk_buff_head *list = &sk->sk_receive_queue;
446 
447 	if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf) {
448 		atomic_inc(&sk->sk_drops);
449 		trace_sock_rcvqueue_full(sk, skb);
450 		return -ENOMEM;
451 	}
452 
453 	if (!sk_rmem_schedule(sk, skb, skb->truesize)) {
454 		atomic_inc(&sk->sk_drops);
455 		return -ENOBUFS;
456 	}
457 
458 	skb->dev = NULL;
459 	skb_set_owner_r(skb, sk);
460 
461 	/* we escape from rcu protected region, make sure we dont leak
462 	 * a norefcounted dst
463 	 */
464 	skb_dst_force(skb);
465 
466 	spin_lock_irqsave(&list->lock, flags);
467 	sock_skb_set_dropcount(sk, skb);
468 	__skb_queue_tail(list, skb);
469 	spin_unlock_irqrestore(&list->lock, flags);
470 
471 	if (!sock_flag(sk, SOCK_DEAD))
472 		sk->sk_data_ready(sk);
473 	return 0;
474 }
475 EXPORT_SYMBOL(__sock_queue_rcv_skb);
476 
477 int sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
478 {
479 	int err;
480 
481 	err = sk_filter(sk, skb);
482 	if (err)
483 		return err;
484 
485 	return __sock_queue_rcv_skb(sk, skb);
486 }
487 EXPORT_SYMBOL(sock_queue_rcv_skb);
488 
489 int __sk_receive_skb(struct sock *sk, struct sk_buff *skb,
490 		     const int nested, unsigned int trim_cap, bool refcounted)
491 {
492 	int rc = NET_RX_SUCCESS;
493 
494 	if (sk_filter_trim_cap(sk, skb, trim_cap))
495 		goto discard_and_relse;
496 
497 	skb->dev = NULL;
498 
499 	if (sk_rcvqueues_full(sk, sk->sk_rcvbuf)) {
500 		atomic_inc(&sk->sk_drops);
501 		goto discard_and_relse;
502 	}
503 	if (nested)
504 		bh_lock_sock_nested(sk);
505 	else
506 		bh_lock_sock(sk);
507 	if (!sock_owned_by_user(sk)) {
508 		/*
509 		 * trylock + unlock semantics:
510 		 */
511 		mutex_acquire(&sk->sk_lock.dep_map, 0, 1, _RET_IP_);
512 
513 		rc = sk_backlog_rcv(sk, skb);
514 
515 		mutex_release(&sk->sk_lock.dep_map, 1, _RET_IP_);
516 	} else if (sk_add_backlog(sk, skb, sk->sk_rcvbuf)) {
517 		bh_unlock_sock(sk);
518 		atomic_inc(&sk->sk_drops);
519 		goto discard_and_relse;
520 	}
521 
522 	bh_unlock_sock(sk);
523 out:
524 	if (refcounted)
525 		sock_put(sk);
526 	return rc;
527 discard_and_relse:
528 	kfree_skb(skb);
529 	goto out;
530 }
531 EXPORT_SYMBOL(__sk_receive_skb);
532 
533 struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie)
534 {
535 	struct dst_entry *dst = __sk_dst_get(sk);
536 
537 	if (dst && dst->obsolete && dst->ops->check(dst, cookie) == NULL) {
538 		sk_tx_queue_clear(sk);
539 		sk->sk_dst_pending_confirm = 0;
540 		RCU_INIT_POINTER(sk->sk_dst_cache, NULL);
541 		dst_release(dst);
542 		return NULL;
543 	}
544 
545 	return dst;
546 }
547 EXPORT_SYMBOL(__sk_dst_check);
548 
549 struct dst_entry *sk_dst_check(struct sock *sk, u32 cookie)
550 {
551 	struct dst_entry *dst = sk_dst_get(sk);
552 
553 	if (dst && dst->obsolete && dst->ops->check(dst, cookie) == NULL) {
554 		sk_dst_reset(sk);
555 		dst_release(dst);
556 		return NULL;
557 	}
558 
559 	return dst;
560 }
561 EXPORT_SYMBOL(sk_dst_check);
562 
563 static int sock_setbindtodevice(struct sock *sk, char __user *optval,
564 				int optlen)
565 {
566 	int ret = -ENOPROTOOPT;
567 #ifdef CONFIG_NETDEVICES
568 	struct net *net = sock_net(sk);
569 	char devname[IFNAMSIZ];
570 	int index;
571 
572 	/* Sorry... */
573 	ret = -EPERM;
574 	if (!ns_capable(net->user_ns, CAP_NET_RAW))
575 		goto out;
576 
577 	ret = -EINVAL;
578 	if (optlen < 0)
579 		goto out;
580 
581 	/* Bind this socket to a particular device like "eth0",
582 	 * as specified in the passed interface name. If the
583 	 * name is "" or the option length is zero the socket
584 	 * is not bound.
585 	 */
586 	if (optlen > IFNAMSIZ - 1)
587 		optlen = IFNAMSIZ - 1;
588 	memset(devname, 0, sizeof(devname));
589 
590 	ret = -EFAULT;
591 	if (copy_from_user(devname, optval, optlen))
592 		goto out;
593 
594 	index = 0;
595 	if (devname[0] != '\0') {
596 		struct net_device *dev;
597 
598 		rcu_read_lock();
599 		dev = dev_get_by_name_rcu(net, devname);
600 		if (dev)
601 			index = dev->ifindex;
602 		rcu_read_unlock();
603 		ret = -ENODEV;
604 		if (!dev)
605 			goto out;
606 	}
607 
608 	lock_sock(sk);
609 	sk->sk_bound_dev_if = index;
610 	sk_dst_reset(sk);
611 	release_sock(sk);
612 
613 	ret = 0;
614 
615 out:
616 #endif
617 
618 	return ret;
619 }
620 
621 static int sock_getbindtodevice(struct sock *sk, char __user *optval,
622 				int __user *optlen, int len)
623 {
624 	int ret = -ENOPROTOOPT;
625 #ifdef CONFIG_NETDEVICES
626 	struct net *net = sock_net(sk);
627 	char devname[IFNAMSIZ];
628 
629 	if (sk->sk_bound_dev_if == 0) {
630 		len = 0;
631 		goto zero;
632 	}
633 
634 	ret = -EINVAL;
635 	if (len < IFNAMSIZ)
636 		goto out;
637 
638 	ret = netdev_get_name(net, devname, sk->sk_bound_dev_if);
639 	if (ret)
640 		goto out;
641 
642 	len = strlen(devname) + 1;
643 
644 	ret = -EFAULT;
645 	if (copy_to_user(optval, devname, len))
646 		goto out;
647 
648 zero:
649 	ret = -EFAULT;
650 	if (put_user(len, optlen))
651 		goto out;
652 
653 	ret = 0;
654 
655 out:
656 #endif
657 
658 	return ret;
659 }
660 
661 static inline void sock_valbool_flag(struct sock *sk, int bit, int valbool)
662 {
663 	if (valbool)
664 		sock_set_flag(sk, bit);
665 	else
666 		sock_reset_flag(sk, bit);
667 }
668 
669 bool sk_mc_loop(struct sock *sk)
670 {
671 	if (dev_recursion_level())
672 		return false;
673 	if (!sk)
674 		return true;
675 	switch (sk->sk_family) {
676 	case AF_INET:
677 		return inet_sk(sk)->mc_loop;
678 #if IS_ENABLED(CONFIG_IPV6)
679 	case AF_INET6:
680 		return inet6_sk(sk)->mc_loop;
681 #endif
682 	}
683 	WARN_ON(1);
684 	return true;
685 }
686 EXPORT_SYMBOL(sk_mc_loop);
687 
688 /*
689  *	This is meant for all protocols to use and covers goings on
690  *	at the socket level. Everything here is generic.
691  */
692 
693 int sock_setsockopt(struct socket *sock, int level, int optname,
694 		    char __user *optval, unsigned int optlen)
695 {
696 	struct sock *sk = sock->sk;
697 	int val;
698 	int valbool;
699 	struct linger ling;
700 	int ret = 0;
701 
702 	/*
703 	 *	Options without arguments
704 	 */
705 
706 	if (optname == SO_BINDTODEVICE)
707 		return sock_setbindtodevice(sk, optval, optlen);
708 
709 	if (optlen < sizeof(int))
710 		return -EINVAL;
711 
712 	if (get_user(val, (int __user *)optval))
713 		return -EFAULT;
714 
715 	valbool = val ? 1 : 0;
716 
717 	lock_sock(sk);
718 
719 	switch (optname) {
720 	case SO_DEBUG:
721 		if (val && !capable(CAP_NET_ADMIN))
722 			ret = -EACCES;
723 		else
724 			sock_valbool_flag(sk, SOCK_DBG, valbool);
725 		break;
726 	case SO_REUSEADDR:
727 		sk->sk_reuse = (valbool ? SK_CAN_REUSE : SK_NO_REUSE);
728 		break;
729 	case SO_REUSEPORT:
730 		sk->sk_reuseport = valbool;
731 		break;
732 	case SO_TYPE:
733 	case SO_PROTOCOL:
734 	case SO_DOMAIN:
735 	case SO_ERROR:
736 		ret = -ENOPROTOOPT;
737 		break;
738 	case SO_DONTROUTE:
739 		sock_valbool_flag(sk, SOCK_LOCALROUTE, valbool);
740 		break;
741 	case SO_BROADCAST:
742 		sock_valbool_flag(sk, SOCK_BROADCAST, valbool);
743 		break;
744 	case SO_SNDBUF:
745 		/* Don't error on this BSD doesn't and if you think
746 		 * about it this is right. Otherwise apps have to
747 		 * play 'guess the biggest size' games. RCVBUF/SNDBUF
748 		 * are treated in BSD as hints
749 		 */
750 		val = min_t(u32, val, sysctl_wmem_max);
751 set_sndbuf:
752 		sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
753 		sk->sk_sndbuf = max_t(int, val * 2, SOCK_MIN_SNDBUF);
754 		/* Wake up sending tasks if we upped the value. */
755 		sk->sk_write_space(sk);
756 		break;
757 
758 	case SO_SNDBUFFORCE:
759 		if (!capable(CAP_NET_ADMIN)) {
760 			ret = -EPERM;
761 			break;
762 		}
763 		goto set_sndbuf;
764 
765 	case SO_RCVBUF:
766 		/* Don't error on this BSD doesn't and if you think
767 		 * about it this is right. Otherwise apps have to
768 		 * play 'guess the biggest size' games. RCVBUF/SNDBUF
769 		 * are treated in BSD as hints
770 		 */
771 		val = min_t(u32, val, sysctl_rmem_max);
772 set_rcvbuf:
773 		sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
774 		/*
775 		 * We double it on the way in to account for
776 		 * "struct sk_buff" etc. overhead.   Applications
777 		 * assume that the SO_RCVBUF setting they make will
778 		 * allow that much actual data to be received on that
779 		 * socket.
780 		 *
781 		 * Applications are unaware that "struct sk_buff" and
782 		 * other overheads allocate from the receive buffer
783 		 * during socket buffer allocation.
784 		 *
785 		 * And after considering the possible alternatives,
786 		 * returning the value we actually used in getsockopt
787 		 * is the most desirable behavior.
788 		 */
789 		sk->sk_rcvbuf = max_t(int, val * 2, SOCK_MIN_RCVBUF);
790 		break;
791 
792 	case SO_RCVBUFFORCE:
793 		if (!capable(CAP_NET_ADMIN)) {
794 			ret = -EPERM;
795 			break;
796 		}
797 		goto set_rcvbuf;
798 
799 	case SO_KEEPALIVE:
800 		if (sk->sk_prot->keepalive)
801 			sk->sk_prot->keepalive(sk, valbool);
802 		sock_valbool_flag(sk, SOCK_KEEPOPEN, valbool);
803 		break;
804 
805 	case SO_OOBINLINE:
806 		sock_valbool_flag(sk, SOCK_URGINLINE, valbool);
807 		break;
808 
809 	case SO_NO_CHECK:
810 		sk->sk_no_check_tx = valbool;
811 		break;
812 
813 	case SO_PRIORITY:
814 		if ((val >= 0 && val <= 6) ||
815 		    ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
816 			sk->sk_priority = val;
817 		else
818 			ret = -EPERM;
819 		break;
820 
821 	case SO_LINGER:
822 		if (optlen < sizeof(ling)) {
823 			ret = -EINVAL;	/* 1003.1g */
824 			break;
825 		}
826 		if (copy_from_user(&ling, optval, sizeof(ling))) {
827 			ret = -EFAULT;
828 			break;
829 		}
830 		if (!ling.l_onoff)
831 			sock_reset_flag(sk, SOCK_LINGER);
832 		else {
833 #if (BITS_PER_LONG == 32)
834 			if ((unsigned int)ling.l_linger >= MAX_SCHEDULE_TIMEOUT/HZ)
835 				sk->sk_lingertime = MAX_SCHEDULE_TIMEOUT;
836 			else
837 #endif
838 				sk->sk_lingertime = (unsigned int)ling.l_linger * HZ;
839 			sock_set_flag(sk, SOCK_LINGER);
840 		}
841 		break;
842 
843 	case SO_BSDCOMPAT:
844 		sock_warn_obsolete_bsdism("setsockopt");
845 		break;
846 
847 	case SO_PASSCRED:
848 		if (valbool)
849 			set_bit(SOCK_PASSCRED, &sock->flags);
850 		else
851 			clear_bit(SOCK_PASSCRED, &sock->flags);
852 		break;
853 
854 	case SO_TIMESTAMP:
855 	case SO_TIMESTAMPNS:
856 		if (valbool)  {
857 			if (optname == SO_TIMESTAMP)
858 				sock_reset_flag(sk, SOCK_RCVTSTAMPNS);
859 			else
860 				sock_set_flag(sk, SOCK_RCVTSTAMPNS);
861 			sock_set_flag(sk, SOCK_RCVTSTAMP);
862 			sock_enable_timestamp(sk, SOCK_TIMESTAMP);
863 		} else {
864 			sock_reset_flag(sk, SOCK_RCVTSTAMP);
865 			sock_reset_flag(sk, SOCK_RCVTSTAMPNS);
866 		}
867 		break;
868 
869 	case SO_TIMESTAMPING:
870 		if (val & ~SOF_TIMESTAMPING_MASK) {
871 			ret = -EINVAL;
872 			break;
873 		}
874 
875 		if (val & SOF_TIMESTAMPING_OPT_ID &&
876 		    !(sk->sk_tsflags & SOF_TIMESTAMPING_OPT_ID)) {
877 			if (sk->sk_protocol == IPPROTO_TCP &&
878 			    sk->sk_type == SOCK_STREAM) {
879 				if ((1 << sk->sk_state) &
880 				    (TCPF_CLOSE | TCPF_LISTEN)) {
881 					ret = -EINVAL;
882 					break;
883 				}
884 				sk->sk_tskey = tcp_sk(sk)->snd_una;
885 			} else {
886 				sk->sk_tskey = 0;
887 			}
888 		}
889 
890 		if (val & SOF_TIMESTAMPING_OPT_STATS &&
891 		    !(val & SOF_TIMESTAMPING_OPT_TSONLY)) {
892 			ret = -EINVAL;
893 			break;
894 		}
895 
896 		sk->sk_tsflags = val;
897 		if (val & SOF_TIMESTAMPING_RX_SOFTWARE)
898 			sock_enable_timestamp(sk,
899 					      SOCK_TIMESTAMPING_RX_SOFTWARE);
900 		else
901 			sock_disable_timestamp(sk,
902 					       (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE));
903 		break;
904 
905 	case SO_RCVLOWAT:
906 		if (val < 0)
907 			val = INT_MAX;
908 		sk->sk_rcvlowat = val ? : 1;
909 		break;
910 
911 	case SO_RCVTIMEO:
912 		ret = sock_set_timeout(&sk->sk_rcvtimeo, optval, optlen);
913 		break;
914 
915 	case SO_SNDTIMEO:
916 		ret = sock_set_timeout(&sk->sk_sndtimeo, optval, optlen);
917 		break;
918 
919 	case SO_ATTACH_FILTER:
920 		ret = -EINVAL;
921 		if (optlen == sizeof(struct sock_fprog)) {
922 			struct sock_fprog fprog;
923 
924 			ret = -EFAULT;
925 			if (copy_from_user(&fprog, optval, sizeof(fprog)))
926 				break;
927 
928 			ret = sk_attach_filter(&fprog, sk);
929 		}
930 		break;
931 
932 	case SO_ATTACH_BPF:
933 		ret = -EINVAL;
934 		if (optlen == sizeof(u32)) {
935 			u32 ufd;
936 
937 			ret = -EFAULT;
938 			if (copy_from_user(&ufd, optval, sizeof(ufd)))
939 				break;
940 
941 			ret = sk_attach_bpf(ufd, sk);
942 		}
943 		break;
944 
945 	case SO_ATTACH_REUSEPORT_CBPF:
946 		ret = -EINVAL;
947 		if (optlen == sizeof(struct sock_fprog)) {
948 			struct sock_fprog fprog;
949 
950 			ret = -EFAULT;
951 			if (copy_from_user(&fprog, optval, sizeof(fprog)))
952 				break;
953 
954 			ret = sk_reuseport_attach_filter(&fprog, sk);
955 		}
956 		break;
957 
958 	case SO_ATTACH_REUSEPORT_EBPF:
959 		ret = -EINVAL;
960 		if (optlen == sizeof(u32)) {
961 			u32 ufd;
962 
963 			ret = -EFAULT;
964 			if (copy_from_user(&ufd, optval, sizeof(ufd)))
965 				break;
966 
967 			ret = sk_reuseport_attach_bpf(ufd, sk);
968 		}
969 		break;
970 
971 	case SO_DETACH_FILTER:
972 		ret = sk_detach_filter(sk);
973 		break;
974 
975 	case SO_LOCK_FILTER:
976 		if (sock_flag(sk, SOCK_FILTER_LOCKED) && !valbool)
977 			ret = -EPERM;
978 		else
979 			sock_valbool_flag(sk, SOCK_FILTER_LOCKED, valbool);
980 		break;
981 
982 	case SO_PASSSEC:
983 		if (valbool)
984 			set_bit(SOCK_PASSSEC, &sock->flags);
985 		else
986 			clear_bit(SOCK_PASSSEC, &sock->flags);
987 		break;
988 	case SO_MARK:
989 		if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
990 			ret = -EPERM;
991 		else
992 			sk->sk_mark = val;
993 		break;
994 
995 	case SO_RXQ_OVFL:
996 		sock_valbool_flag(sk, SOCK_RXQ_OVFL, valbool);
997 		break;
998 
999 	case SO_WIFI_STATUS:
1000 		sock_valbool_flag(sk, SOCK_WIFI_STATUS, valbool);
1001 		break;
1002 
1003 	case SO_PEEK_OFF:
1004 		if (sock->ops->set_peek_off)
1005 			ret = sock->ops->set_peek_off(sk, val);
1006 		else
1007 			ret = -EOPNOTSUPP;
1008 		break;
1009 
1010 	case SO_NOFCS:
1011 		sock_valbool_flag(sk, SOCK_NOFCS, valbool);
1012 		break;
1013 
1014 	case SO_SELECT_ERR_QUEUE:
1015 		sock_valbool_flag(sk, SOCK_SELECT_ERR_QUEUE, valbool);
1016 		break;
1017 
1018 #ifdef CONFIG_NET_RX_BUSY_POLL
1019 	case SO_BUSY_POLL:
1020 		/* allow unprivileged users to decrease the value */
1021 		if ((val > sk->sk_ll_usec) && !capable(CAP_NET_ADMIN))
1022 			ret = -EPERM;
1023 		else {
1024 			if (val < 0)
1025 				ret = -EINVAL;
1026 			else
1027 				sk->sk_ll_usec = val;
1028 		}
1029 		break;
1030 #endif
1031 
1032 	case SO_MAX_PACING_RATE:
1033 		if (val != ~0U)
1034 			cmpxchg(&sk->sk_pacing_status,
1035 				SK_PACING_NONE,
1036 				SK_PACING_NEEDED);
1037 		sk->sk_max_pacing_rate = val;
1038 		sk->sk_pacing_rate = min(sk->sk_pacing_rate,
1039 					 sk->sk_max_pacing_rate);
1040 		break;
1041 
1042 	case SO_INCOMING_CPU:
1043 		sk->sk_incoming_cpu = val;
1044 		break;
1045 
1046 	case SO_CNX_ADVICE:
1047 		if (val == 1)
1048 			dst_negative_advice(sk);
1049 		break;
1050 
1051 	case SO_ZEROCOPY:
1052 		if (sk->sk_family == PF_INET || sk->sk_family == PF_INET6) {
1053 			if (sk->sk_protocol != IPPROTO_TCP)
1054 				ret = -ENOTSUPP;
1055 		} else if (sk->sk_family != PF_RDS) {
1056 			ret = -ENOTSUPP;
1057 		}
1058 		if (!ret) {
1059 			if (val < 0 || val > 1)
1060 				ret = -EINVAL;
1061 			else
1062 				sock_valbool_flag(sk, SOCK_ZEROCOPY, valbool);
1063 		}
1064 		break;
1065 
1066 	default:
1067 		ret = -ENOPROTOOPT;
1068 		break;
1069 	}
1070 	release_sock(sk);
1071 	return ret;
1072 }
1073 EXPORT_SYMBOL(sock_setsockopt);
1074 
1075 
1076 static void cred_to_ucred(struct pid *pid, const struct cred *cred,
1077 			  struct ucred *ucred)
1078 {
1079 	ucred->pid = pid_vnr(pid);
1080 	ucred->uid = ucred->gid = -1;
1081 	if (cred) {
1082 		struct user_namespace *current_ns = current_user_ns();
1083 
1084 		ucred->uid = from_kuid_munged(current_ns, cred->euid);
1085 		ucred->gid = from_kgid_munged(current_ns, cred->egid);
1086 	}
1087 }
1088 
1089 static int groups_to_user(gid_t __user *dst, const struct group_info *src)
1090 {
1091 	struct user_namespace *user_ns = current_user_ns();
1092 	int i;
1093 
1094 	for (i = 0; i < src->ngroups; i++)
1095 		if (put_user(from_kgid_munged(user_ns, src->gid[i]), dst + i))
1096 			return -EFAULT;
1097 
1098 	return 0;
1099 }
1100 
1101 int sock_getsockopt(struct socket *sock, int level, int optname,
1102 		    char __user *optval, int __user *optlen)
1103 {
1104 	struct sock *sk = sock->sk;
1105 
1106 	union {
1107 		int val;
1108 		u64 val64;
1109 		struct linger ling;
1110 		struct timeval tm;
1111 	} v;
1112 
1113 	int lv = sizeof(int);
1114 	int len;
1115 
1116 	if (get_user(len, optlen))
1117 		return -EFAULT;
1118 	if (len < 0)
1119 		return -EINVAL;
1120 
1121 	memset(&v, 0, sizeof(v));
1122 
1123 	switch (optname) {
1124 	case SO_DEBUG:
1125 		v.val = sock_flag(sk, SOCK_DBG);
1126 		break;
1127 
1128 	case SO_DONTROUTE:
1129 		v.val = sock_flag(sk, SOCK_LOCALROUTE);
1130 		break;
1131 
1132 	case SO_BROADCAST:
1133 		v.val = sock_flag(sk, SOCK_BROADCAST);
1134 		break;
1135 
1136 	case SO_SNDBUF:
1137 		v.val = sk->sk_sndbuf;
1138 		break;
1139 
1140 	case SO_RCVBUF:
1141 		v.val = sk->sk_rcvbuf;
1142 		break;
1143 
1144 	case SO_REUSEADDR:
1145 		v.val = sk->sk_reuse;
1146 		break;
1147 
1148 	case SO_REUSEPORT:
1149 		v.val = sk->sk_reuseport;
1150 		break;
1151 
1152 	case SO_KEEPALIVE:
1153 		v.val = sock_flag(sk, SOCK_KEEPOPEN);
1154 		break;
1155 
1156 	case SO_TYPE:
1157 		v.val = sk->sk_type;
1158 		break;
1159 
1160 	case SO_PROTOCOL:
1161 		v.val = sk->sk_protocol;
1162 		break;
1163 
1164 	case SO_DOMAIN:
1165 		v.val = sk->sk_family;
1166 		break;
1167 
1168 	case SO_ERROR:
1169 		v.val = -sock_error(sk);
1170 		if (v.val == 0)
1171 			v.val = xchg(&sk->sk_err_soft, 0);
1172 		break;
1173 
1174 	case SO_OOBINLINE:
1175 		v.val = sock_flag(sk, SOCK_URGINLINE);
1176 		break;
1177 
1178 	case SO_NO_CHECK:
1179 		v.val = sk->sk_no_check_tx;
1180 		break;
1181 
1182 	case SO_PRIORITY:
1183 		v.val = sk->sk_priority;
1184 		break;
1185 
1186 	case SO_LINGER:
1187 		lv		= sizeof(v.ling);
1188 		v.ling.l_onoff	= sock_flag(sk, SOCK_LINGER);
1189 		v.ling.l_linger	= sk->sk_lingertime / HZ;
1190 		break;
1191 
1192 	case SO_BSDCOMPAT:
1193 		sock_warn_obsolete_bsdism("getsockopt");
1194 		break;
1195 
1196 	case SO_TIMESTAMP:
1197 		v.val = sock_flag(sk, SOCK_RCVTSTAMP) &&
1198 				!sock_flag(sk, SOCK_RCVTSTAMPNS);
1199 		break;
1200 
1201 	case SO_TIMESTAMPNS:
1202 		v.val = sock_flag(sk, SOCK_RCVTSTAMPNS);
1203 		break;
1204 
1205 	case SO_TIMESTAMPING:
1206 		v.val = sk->sk_tsflags;
1207 		break;
1208 
1209 	case SO_RCVTIMEO:
1210 		lv = sizeof(struct timeval);
1211 		if (sk->sk_rcvtimeo == MAX_SCHEDULE_TIMEOUT) {
1212 			v.tm.tv_sec = 0;
1213 			v.tm.tv_usec = 0;
1214 		} else {
1215 			v.tm.tv_sec = sk->sk_rcvtimeo / HZ;
1216 			v.tm.tv_usec = ((sk->sk_rcvtimeo % HZ) * USEC_PER_SEC) / HZ;
1217 		}
1218 		break;
1219 
1220 	case SO_SNDTIMEO:
1221 		lv = sizeof(struct timeval);
1222 		if (sk->sk_sndtimeo == MAX_SCHEDULE_TIMEOUT) {
1223 			v.tm.tv_sec = 0;
1224 			v.tm.tv_usec = 0;
1225 		} else {
1226 			v.tm.tv_sec = sk->sk_sndtimeo / HZ;
1227 			v.tm.tv_usec = ((sk->sk_sndtimeo % HZ) * USEC_PER_SEC) / HZ;
1228 		}
1229 		break;
1230 
1231 	case SO_RCVLOWAT:
1232 		v.val = sk->sk_rcvlowat;
1233 		break;
1234 
1235 	case SO_SNDLOWAT:
1236 		v.val = 1;
1237 		break;
1238 
1239 	case SO_PASSCRED:
1240 		v.val = !!test_bit(SOCK_PASSCRED, &sock->flags);
1241 		break;
1242 
1243 	case SO_PEERCRED:
1244 	{
1245 		struct ucred peercred;
1246 		if (len > sizeof(peercred))
1247 			len = sizeof(peercred);
1248 		cred_to_ucred(sk->sk_peer_pid, sk->sk_peer_cred, &peercred);
1249 		if (copy_to_user(optval, &peercred, len))
1250 			return -EFAULT;
1251 		goto lenout;
1252 	}
1253 
1254 	case SO_PEERGROUPS:
1255 	{
1256 		int ret, n;
1257 
1258 		if (!sk->sk_peer_cred)
1259 			return -ENODATA;
1260 
1261 		n = sk->sk_peer_cred->group_info->ngroups;
1262 		if (len < n * sizeof(gid_t)) {
1263 			len = n * sizeof(gid_t);
1264 			return put_user(len, optlen) ? -EFAULT : -ERANGE;
1265 		}
1266 		len = n * sizeof(gid_t);
1267 
1268 		ret = groups_to_user((gid_t __user *)optval,
1269 				     sk->sk_peer_cred->group_info);
1270 		if (ret)
1271 			return ret;
1272 		goto lenout;
1273 	}
1274 
1275 	case SO_PEERNAME:
1276 	{
1277 		char address[128];
1278 
1279 		lv = sock->ops->getname(sock, (struct sockaddr *)address, 2);
1280 		if (lv < 0)
1281 			return -ENOTCONN;
1282 		if (lv < len)
1283 			return -EINVAL;
1284 		if (copy_to_user(optval, address, len))
1285 			return -EFAULT;
1286 		goto lenout;
1287 	}
1288 
1289 	/* Dubious BSD thing... Probably nobody even uses it, but
1290 	 * the UNIX standard wants it for whatever reason... -DaveM
1291 	 */
1292 	case SO_ACCEPTCONN:
1293 		v.val = sk->sk_state == TCP_LISTEN;
1294 		break;
1295 
1296 	case SO_PASSSEC:
1297 		v.val = !!test_bit(SOCK_PASSSEC, &sock->flags);
1298 		break;
1299 
1300 	case SO_PEERSEC:
1301 		return security_socket_getpeersec_stream(sock, optval, optlen, len);
1302 
1303 	case SO_MARK:
1304 		v.val = sk->sk_mark;
1305 		break;
1306 
1307 	case SO_RXQ_OVFL:
1308 		v.val = sock_flag(sk, SOCK_RXQ_OVFL);
1309 		break;
1310 
1311 	case SO_WIFI_STATUS:
1312 		v.val = sock_flag(sk, SOCK_WIFI_STATUS);
1313 		break;
1314 
1315 	case SO_PEEK_OFF:
1316 		if (!sock->ops->set_peek_off)
1317 			return -EOPNOTSUPP;
1318 
1319 		v.val = sk->sk_peek_off;
1320 		break;
1321 	case SO_NOFCS:
1322 		v.val = sock_flag(sk, SOCK_NOFCS);
1323 		break;
1324 
1325 	case SO_BINDTODEVICE:
1326 		return sock_getbindtodevice(sk, optval, optlen, len);
1327 
1328 	case SO_GET_FILTER:
1329 		len = sk_get_filter(sk, (struct sock_filter __user *)optval, len);
1330 		if (len < 0)
1331 			return len;
1332 
1333 		goto lenout;
1334 
1335 	case SO_LOCK_FILTER:
1336 		v.val = sock_flag(sk, SOCK_FILTER_LOCKED);
1337 		break;
1338 
1339 	case SO_BPF_EXTENSIONS:
1340 		v.val = bpf_tell_extensions();
1341 		break;
1342 
1343 	case SO_SELECT_ERR_QUEUE:
1344 		v.val = sock_flag(sk, SOCK_SELECT_ERR_QUEUE);
1345 		break;
1346 
1347 #ifdef CONFIG_NET_RX_BUSY_POLL
1348 	case SO_BUSY_POLL:
1349 		v.val = sk->sk_ll_usec;
1350 		break;
1351 #endif
1352 
1353 	case SO_MAX_PACING_RATE:
1354 		v.val = sk->sk_max_pacing_rate;
1355 		break;
1356 
1357 	case SO_INCOMING_CPU:
1358 		v.val = sk->sk_incoming_cpu;
1359 		break;
1360 
1361 	case SO_MEMINFO:
1362 	{
1363 		u32 meminfo[SK_MEMINFO_VARS];
1364 
1365 		if (get_user(len, optlen))
1366 			return -EFAULT;
1367 
1368 		sk_get_meminfo(sk, meminfo);
1369 
1370 		len = min_t(unsigned int, len, sizeof(meminfo));
1371 		if (copy_to_user(optval, &meminfo, len))
1372 			return -EFAULT;
1373 
1374 		goto lenout;
1375 	}
1376 
1377 #ifdef CONFIG_NET_RX_BUSY_POLL
1378 	case SO_INCOMING_NAPI_ID:
1379 		v.val = READ_ONCE(sk->sk_napi_id);
1380 
1381 		/* aggregate non-NAPI IDs down to 0 */
1382 		if (v.val < MIN_NAPI_ID)
1383 			v.val = 0;
1384 
1385 		break;
1386 #endif
1387 
1388 	case SO_COOKIE:
1389 		lv = sizeof(u64);
1390 		if (len < lv)
1391 			return -EINVAL;
1392 		v.val64 = sock_gen_cookie(sk);
1393 		break;
1394 
1395 	case SO_ZEROCOPY:
1396 		v.val = sock_flag(sk, SOCK_ZEROCOPY);
1397 		break;
1398 
1399 	default:
1400 		/* We implement the SO_SNDLOWAT etc to not be settable
1401 		 * (1003.1g 7).
1402 		 */
1403 		return -ENOPROTOOPT;
1404 	}
1405 
1406 	if (len > lv)
1407 		len = lv;
1408 	if (copy_to_user(optval, &v, len))
1409 		return -EFAULT;
1410 lenout:
1411 	if (put_user(len, optlen))
1412 		return -EFAULT;
1413 	return 0;
1414 }
1415 
1416 /*
1417  * Initialize an sk_lock.
1418  *
1419  * (We also register the sk_lock with the lock validator.)
1420  */
1421 static inline void sock_lock_init(struct sock *sk)
1422 {
1423 	if (sk->sk_kern_sock)
1424 		sock_lock_init_class_and_name(
1425 			sk,
1426 			af_family_kern_slock_key_strings[sk->sk_family],
1427 			af_family_kern_slock_keys + sk->sk_family,
1428 			af_family_kern_key_strings[sk->sk_family],
1429 			af_family_kern_keys + sk->sk_family);
1430 	else
1431 		sock_lock_init_class_and_name(
1432 			sk,
1433 			af_family_slock_key_strings[sk->sk_family],
1434 			af_family_slock_keys + sk->sk_family,
1435 			af_family_key_strings[sk->sk_family],
1436 			af_family_keys + sk->sk_family);
1437 }
1438 
1439 /*
1440  * Copy all fields from osk to nsk but nsk->sk_refcnt must not change yet,
1441  * even temporarly, because of RCU lookups. sk_node should also be left as is.
1442  * We must not copy fields between sk_dontcopy_begin and sk_dontcopy_end
1443  */
1444 static void sock_copy(struct sock *nsk, const struct sock *osk)
1445 {
1446 #ifdef CONFIG_SECURITY_NETWORK
1447 	void *sptr = nsk->sk_security;
1448 #endif
1449 	memcpy(nsk, osk, offsetof(struct sock, sk_dontcopy_begin));
1450 
1451 	memcpy(&nsk->sk_dontcopy_end, &osk->sk_dontcopy_end,
1452 	       osk->sk_prot->obj_size - offsetof(struct sock, sk_dontcopy_end));
1453 
1454 #ifdef CONFIG_SECURITY_NETWORK
1455 	nsk->sk_security = sptr;
1456 	security_sk_clone(osk, nsk);
1457 #endif
1458 }
1459 
1460 static struct sock *sk_prot_alloc(struct proto *prot, gfp_t priority,
1461 		int family)
1462 {
1463 	struct sock *sk;
1464 	struct kmem_cache *slab;
1465 
1466 	slab = prot->slab;
1467 	if (slab != NULL) {
1468 		sk = kmem_cache_alloc(slab, priority & ~__GFP_ZERO);
1469 		if (!sk)
1470 			return sk;
1471 		if (priority & __GFP_ZERO)
1472 			sk_prot_clear_nulls(sk, prot->obj_size);
1473 	} else
1474 		sk = kmalloc(prot->obj_size, priority);
1475 
1476 	if (sk != NULL) {
1477 		if (security_sk_alloc(sk, family, priority))
1478 			goto out_free;
1479 
1480 		if (!try_module_get(prot->owner))
1481 			goto out_free_sec;
1482 		sk_tx_queue_clear(sk);
1483 	}
1484 
1485 	return sk;
1486 
1487 out_free_sec:
1488 	security_sk_free(sk);
1489 out_free:
1490 	if (slab != NULL)
1491 		kmem_cache_free(slab, sk);
1492 	else
1493 		kfree(sk);
1494 	return NULL;
1495 }
1496 
1497 static void sk_prot_free(struct proto *prot, struct sock *sk)
1498 {
1499 	struct kmem_cache *slab;
1500 	struct module *owner;
1501 
1502 	owner = prot->owner;
1503 	slab = prot->slab;
1504 
1505 	cgroup_sk_free(&sk->sk_cgrp_data);
1506 	mem_cgroup_sk_free(sk);
1507 	security_sk_free(sk);
1508 	if (slab != NULL)
1509 		kmem_cache_free(slab, sk);
1510 	else
1511 		kfree(sk);
1512 	module_put(owner);
1513 }
1514 
1515 /**
1516  *	sk_alloc - All socket objects are allocated here
1517  *	@net: the applicable net namespace
1518  *	@family: protocol family
1519  *	@priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
1520  *	@prot: struct proto associated with this new sock instance
1521  *	@kern: is this to be a kernel socket?
1522  */
1523 struct sock *sk_alloc(struct net *net, int family, gfp_t priority,
1524 		      struct proto *prot, int kern)
1525 {
1526 	struct sock *sk;
1527 
1528 	sk = sk_prot_alloc(prot, priority | __GFP_ZERO, family);
1529 	if (sk) {
1530 		sk->sk_family = family;
1531 		/*
1532 		 * See comment in struct sock definition to understand
1533 		 * why we need sk_prot_creator -acme
1534 		 */
1535 		sk->sk_prot = sk->sk_prot_creator = prot;
1536 		sk->sk_kern_sock = kern;
1537 		sock_lock_init(sk);
1538 		sk->sk_net_refcnt = kern ? 0 : 1;
1539 		if (likely(sk->sk_net_refcnt)) {
1540 			get_net(net);
1541 			sock_inuse_add(net, 1);
1542 		}
1543 
1544 		sock_net_set(sk, net);
1545 		refcount_set(&sk->sk_wmem_alloc, 1);
1546 
1547 		mem_cgroup_sk_alloc(sk);
1548 		cgroup_sk_alloc(&sk->sk_cgrp_data);
1549 		sock_update_classid(&sk->sk_cgrp_data);
1550 		sock_update_netprioidx(&sk->sk_cgrp_data);
1551 	}
1552 
1553 	return sk;
1554 }
1555 EXPORT_SYMBOL(sk_alloc);
1556 
1557 /* Sockets having SOCK_RCU_FREE will call this function after one RCU
1558  * grace period. This is the case for UDP sockets and TCP listeners.
1559  */
1560 static void __sk_destruct(struct rcu_head *head)
1561 {
1562 	struct sock *sk = container_of(head, struct sock, sk_rcu);
1563 	struct sk_filter *filter;
1564 
1565 	if (sk->sk_destruct)
1566 		sk->sk_destruct(sk);
1567 
1568 	filter = rcu_dereference_check(sk->sk_filter,
1569 				       refcount_read(&sk->sk_wmem_alloc) == 0);
1570 	if (filter) {
1571 		sk_filter_uncharge(sk, filter);
1572 		RCU_INIT_POINTER(sk->sk_filter, NULL);
1573 	}
1574 	if (rcu_access_pointer(sk->sk_reuseport_cb))
1575 		reuseport_detach_sock(sk);
1576 
1577 	sock_disable_timestamp(sk, SK_FLAGS_TIMESTAMP);
1578 
1579 	if (atomic_read(&sk->sk_omem_alloc))
1580 		pr_debug("%s: optmem leakage (%d bytes) detected\n",
1581 			 __func__, atomic_read(&sk->sk_omem_alloc));
1582 
1583 	if (sk->sk_frag.page) {
1584 		put_page(sk->sk_frag.page);
1585 		sk->sk_frag.page = NULL;
1586 	}
1587 
1588 	if (sk->sk_peer_cred)
1589 		put_cred(sk->sk_peer_cred);
1590 	put_pid(sk->sk_peer_pid);
1591 	if (likely(sk->sk_net_refcnt))
1592 		put_net(sock_net(sk));
1593 	sk_prot_free(sk->sk_prot_creator, sk);
1594 }
1595 
1596 void sk_destruct(struct sock *sk)
1597 {
1598 	if (sock_flag(sk, SOCK_RCU_FREE))
1599 		call_rcu(&sk->sk_rcu, __sk_destruct);
1600 	else
1601 		__sk_destruct(&sk->sk_rcu);
1602 }
1603 
1604 static void __sk_free(struct sock *sk)
1605 {
1606 	if (likely(sk->sk_net_refcnt))
1607 		sock_inuse_add(sock_net(sk), -1);
1608 
1609 	if (unlikely(sock_diag_has_destroy_listeners(sk) && sk->sk_net_refcnt))
1610 		sock_diag_broadcast_destroy(sk);
1611 	else
1612 		sk_destruct(sk);
1613 }
1614 
1615 void sk_free(struct sock *sk)
1616 {
1617 	/*
1618 	 * We subtract one from sk_wmem_alloc and can know if
1619 	 * some packets are still in some tx queue.
1620 	 * If not null, sock_wfree() will call __sk_free(sk) later
1621 	 */
1622 	if (refcount_dec_and_test(&sk->sk_wmem_alloc))
1623 		__sk_free(sk);
1624 }
1625 EXPORT_SYMBOL(sk_free);
1626 
1627 static void sk_init_common(struct sock *sk)
1628 {
1629 	skb_queue_head_init(&sk->sk_receive_queue);
1630 	skb_queue_head_init(&sk->sk_write_queue);
1631 	skb_queue_head_init(&sk->sk_error_queue);
1632 
1633 	rwlock_init(&sk->sk_callback_lock);
1634 	lockdep_set_class_and_name(&sk->sk_receive_queue.lock,
1635 			af_rlock_keys + sk->sk_family,
1636 			af_family_rlock_key_strings[sk->sk_family]);
1637 	lockdep_set_class_and_name(&sk->sk_write_queue.lock,
1638 			af_wlock_keys + sk->sk_family,
1639 			af_family_wlock_key_strings[sk->sk_family]);
1640 	lockdep_set_class_and_name(&sk->sk_error_queue.lock,
1641 			af_elock_keys + sk->sk_family,
1642 			af_family_elock_key_strings[sk->sk_family]);
1643 	lockdep_set_class_and_name(&sk->sk_callback_lock,
1644 			af_callback_keys + sk->sk_family,
1645 			af_family_clock_key_strings[sk->sk_family]);
1646 }
1647 
1648 /**
1649  *	sk_clone_lock - clone a socket, and lock its clone
1650  *	@sk: the socket to clone
1651  *	@priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
1652  *
1653  *	Caller must unlock socket even in error path (bh_unlock_sock(newsk))
1654  */
1655 struct sock *sk_clone_lock(const struct sock *sk, const gfp_t priority)
1656 {
1657 	struct sock *newsk;
1658 	bool is_charged = true;
1659 
1660 	newsk = sk_prot_alloc(sk->sk_prot, priority, sk->sk_family);
1661 	if (newsk != NULL) {
1662 		struct sk_filter *filter;
1663 
1664 		sock_copy(newsk, sk);
1665 
1666 		newsk->sk_prot_creator = sk->sk_prot;
1667 
1668 		/* SANITY */
1669 		if (likely(newsk->sk_net_refcnt))
1670 			get_net(sock_net(newsk));
1671 		sk_node_init(&newsk->sk_node);
1672 		sock_lock_init(newsk);
1673 		bh_lock_sock(newsk);
1674 		newsk->sk_backlog.head	= newsk->sk_backlog.tail = NULL;
1675 		newsk->sk_backlog.len = 0;
1676 
1677 		atomic_set(&newsk->sk_rmem_alloc, 0);
1678 		/*
1679 		 * sk_wmem_alloc set to one (see sk_free() and sock_wfree())
1680 		 */
1681 		refcount_set(&newsk->sk_wmem_alloc, 1);
1682 		atomic_set(&newsk->sk_omem_alloc, 0);
1683 		sk_init_common(newsk);
1684 
1685 		newsk->sk_dst_cache	= NULL;
1686 		newsk->sk_dst_pending_confirm = 0;
1687 		newsk->sk_wmem_queued	= 0;
1688 		newsk->sk_forward_alloc = 0;
1689 		atomic_set(&newsk->sk_drops, 0);
1690 		newsk->sk_send_head	= NULL;
1691 		newsk->sk_userlocks	= sk->sk_userlocks & ~SOCK_BINDPORT_LOCK;
1692 		atomic_set(&newsk->sk_zckey, 0);
1693 
1694 		sock_reset_flag(newsk, SOCK_DONE);
1695 		mem_cgroup_sk_alloc(newsk);
1696 		cgroup_sk_alloc(&newsk->sk_cgrp_data);
1697 
1698 		rcu_read_lock();
1699 		filter = rcu_dereference(sk->sk_filter);
1700 		if (filter != NULL)
1701 			/* though it's an empty new sock, the charging may fail
1702 			 * if sysctl_optmem_max was changed between creation of
1703 			 * original socket and cloning
1704 			 */
1705 			is_charged = sk_filter_charge(newsk, filter);
1706 		RCU_INIT_POINTER(newsk->sk_filter, filter);
1707 		rcu_read_unlock();
1708 
1709 		if (unlikely(!is_charged || xfrm_sk_clone_policy(newsk, sk))) {
1710 			/* We need to make sure that we don't uncharge the new
1711 			 * socket if we couldn't charge it in the first place
1712 			 * as otherwise we uncharge the parent's filter.
1713 			 */
1714 			if (!is_charged)
1715 				RCU_INIT_POINTER(newsk->sk_filter, NULL);
1716 			sk_free_unlock_clone(newsk);
1717 			newsk = NULL;
1718 			goto out;
1719 		}
1720 		RCU_INIT_POINTER(newsk->sk_reuseport_cb, NULL);
1721 
1722 		newsk->sk_err	   = 0;
1723 		newsk->sk_err_soft = 0;
1724 		newsk->sk_priority = 0;
1725 		newsk->sk_incoming_cpu = raw_smp_processor_id();
1726 		atomic64_set(&newsk->sk_cookie, 0);
1727 		if (likely(newsk->sk_net_refcnt))
1728 			sock_inuse_add(sock_net(newsk), 1);
1729 
1730 		/*
1731 		 * Before updating sk_refcnt, we must commit prior changes to memory
1732 		 * (Documentation/RCU/rculist_nulls.txt for details)
1733 		 */
1734 		smp_wmb();
1735 		refcount_set(&newsk->sk_refcnt, 2);
1736 
1737 		/*
1738 		 * Increment the counter in the same struct proto as the master
1739 		 * sock (sk_refcnt_debug_inc uses newsk->sk_prot->socks, that
1740 		 * is the same as sk->sk_prot->socks, as this field was copied
1741 		 * with memcpy).
1742 		 *
1743 		 * This _changes_ the previous behaviour, where
1744 		 * tcp_create_openreq_child always was incrementing the
1745 		 * equivalent to tcp_prot->socks (inet_sock_nr), so this have
1746 		 * to be taken into account in all callers. -acme
1747 		 */
1748 		sk_refcnt_debug_inc(newsk);
1749 		sk_set_socket(newsk, NULL);
1750 		newsk->sk_wq = NULL;
1751 
1752 		if (newsk->sk_prot->sockets_allocated)
1753 			sk_sockets_allocated_inc(newsk);
1754 
1755 		if (sock_needs_netstamp(sk) &&
1756 		    newsk->sk_flags & SK_FLAGS_TIMESTAMP)
1757 			net_enable_timestamp();
1758 	}
1759 out:
1760 	return newsk;
1761 }
1762 EXPORT_SYMBOL_GPL(sk_clone_lock);
1763 
1764 void sk_free_unlock_clone(struct sock *sk)
1765 {
1766 	/* It is still raw copy of parent, so invalidate
1767 	 * destructor and make plain sk_free() */
1768 	sk->sk_destruct = NULL;
1769 	bh_unlock_sock(sk);
1770 	sk_free(sk);
1771 }
1772 EXPORT_SYMBOL_GPL(sk_free_unlock_clone);
1773 
1774 void sk_setup_caps(struct sock *sk, struct dst_entry *dst)
1775 {
1776 	u32 max_segs = 1;
1777 
1778 	sk_dst_set(sk, dst);
1779 	sk->sk_route_caps = dst->dev->features | sk->sk_route_forced_caps;
1780 	if (sk->sk_route_caps & NETIF_F_GSO)
1781 		sk->sk_route_caps |= NETIF_F_GSO_SOFTWARE;
1782 	sk->sk_route_caps &= ~sk->sk_route_nocaps;
1783 	if (sk_can_gso(sk)) {
1784 		if (dst->header_len && !xfrm_dst_offload_ok(dst)) {
1785 			sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
1786 		} else {
1787 			sk->sk_route_caps |= NETIF_F_SG | NETIF_F_HW_CSUM;
1788 			sk->sk_gso_max_size = dst->dev->gso_max_size;
1789 			max_segs = max_t(u32, dst->dev->gso_max_segs, 1);
1790 		}
1791 	}
1792 	sk->sk_gso_max_segs = max_segs;
1793 }
1794 EXPORT_SYMBOL_GPL(sk_setup_caps);
1795 
1796 /*
1797  *	Simple resource managers for sockets.
1798  */
1799 
1800 
1801 /*
1802  * Write buffer destructor automatically called from kfree_skb.
1803  */
1804 void sock_wfree(struct sk_buff *skb)
1805 {
1806 	struct sock *sk = skb->sk;
1807 	unsigned int len = skb->truesize;
1808 
1809 	if (!sock_flag(sk, SOCK_USE_WRITE_QUEUE)) {
1810 		/*
1811 		 * Keep a reference on sk_wmem_alloc, this will be released
1812 		 * after sk_write_space() call
1813 		 */
1814 		WARN_ON(refcount_sub_and_test(len - 1, &sk->sk_wmem_alloc));
1815 		sk->sk_write_space(sk);
1816 		len = 1;
1817 	}
1818 	/*
1819 	 * if sk_wmem_alloc reaches 0, we must finish what sk_free()
1820 	 * could not do because of in-flight packets
1821 	 */
1822 	if (refcount_sub_and_test(len, &sk->sk_wmem_alloc))
1823 		__sk_free(sk);
1824 }
1825 EXPORT_SYMBOL(sock_wfree);
1826 
1827 /* This variant of sock_wfree() is used by TCP,
1828  * since it sets SOCK_USE_WRITE_QUEUE.
1829  */
1830 void __sock_wfree(struct sk_buff *skb)
1831 {
1832 	struct sock *sk = skb->sk;
1833 
1834 	if (refcount_sub_and_test(skb->truesize, &sk->sk_wmem_alloc))
1835 		__sk_free(sk);
1836 }
1837 
1838 void skb_set_owner_w(struct sk_buff *skb, struct sock *sk)
1839 {
1840 	skb_orphan(skb);
1841 	skb->sk = sk;
1842 #ifdef CONFIG_INET
1843 	if (unlikely(!sk_fullsock(sk))) {
1844 		skb->destructor = sock_edemux;
1845 		sock_hold(sk);
1846 		return;
1847 	}
1848 #endif
1849 	skb->destructor = sock_wfree;
1850 	skb_set_hash_from_sk(skb, sk);
1851 	/*
1852 	 * We used to take a refcount on sk, but following operation
1853 	 * is enough to guarantee sk_free() wont free this sock until
1854 	 * all in-flight packets are completed
1855 	 */
1856 	refcount_add(skb->truesize, &sk->sk_wmem_alloc);
1857 }
1858 EXPORT_SYMBOL(skb_set_owner_w);
1859 
1860 /* This helper is used by netem, as it can hold packets in its
1861  * delay queue. We want to allow the owner socket to send more
1862  * packets, as if they were already TX completed by a typical driver.
1863  * But we also want to keep skb->sk set because some packet schedulers
1864  * rely on it (sch_fq for example).
1865  */
1866 void skb_orphan_partial(struct sk_buff *skb)
1867 {
1868 	if (skb_is_tcp_pure_ack(skb))
1869 		return;
1870 
1871 	if (skb->destructor == sock_wfree
1872 #ifdef CONFIG_INET
1873 	    || skb->destructor == tcp_wfree
1874 #endif
1875 		) {
1876 		struct sock *sk = skb->sk;
1877 
1878 		if (refcount_inc_not_zero(&sk->sk_refcnt)) {
1879 			WARN_ON(refcount_sub_and_test(skb->truesize, &sk->sk_wmem_alloc));
1880 			skb->destructor = sock_efree;
1881 		}
1882 	} else {
1883 		skb_orphan(skb);
1884 	}
1885 }
1886 EXPORT_SYMBOL(skb_orphan_partial);
1887 
1888 /*
1889  * Read buffer destructor automatically called from kfree_skb.
1890  */
1891 void sock_rfree(struct sk_buff *skb)
1892 {
1893 	struct sock *sk = skb->sk;
1894 	unsigned int len = skb->truesize;
1895 
1896 	atomic_sub(len, &sk->sk_rmem_alloc);
1897 	sk_mem_uncharge(sk, len);
1898 }
1899 EXPORT_SYMBOL(sock_rfree);
1900 
1901 /*
1902  * Buffer destructor for skbs that are not used directly in read or write
1903  * path, e.g. for error handler skbs. Automatically called from kfree_skb.
1904  */
1905 void sock_efree(struct sk_buff *skb)
1906 {
1907 	sock_put(skb->sk);
1908 }
1909 EXPORT_SYMBOL(sock_efree);
1910 
1911 kuid_t sock_i_uid(struct sock *sk)
1912 {
1913 	kuid_t uid;
1914 
1915 	read_lock_bh(&sk->sk_callback_lock);
1916 	uid = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_uid : GLOBAL_ROOT_UID;
1917 	read_unlock_bh(&sk->sk_callback_lock);
1918 	return uid;
1919 }
1920 EXPORT_SYMBOL(sock_i_uid);
1921 
1922 unsigned long sock_i_ino(struct sock *sk)
1923 {
1924 	unsigned long ino;
1925 
1926 	read_lock_bh(&sk->sk_callback_lock);
1927 	ino = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_ino : 0;
1928 	read_unlock_bh(&sk->sk_callback_lock);
1929 	return ino;
1930 }
1931 EXPORT_SYMBOL(sock_i_ino);
1932 
1933 /*
1934  * Allocate a skb from the socket's send buffer.
1935  */
1936 struct sk_buff *sock_wmalloc(struct sock *sk, unsigned long size, int force,
1937 			     gfp_t priority)
1938 {
1939 	if (force || refcount_read(&sk->sk_wmem_alloc) < sk->sk_sndbuf) {
1940 		struct sk_buff *skb = alloc_skb(size, priority);
1941 		if (skb) {
1942 			skb_set_owner_w(skb, sk);
1943 			return skb;
1944 		}
1945 	}
1946 	return NULL;
1947 }
1948 EXPORT_SYMBOL(sock_wmalloc);
1949 
1950 static void sock_ofree(struct sk_buff *skb)
1951 {
1952 	struct sock *sk = skb->sk;
1953 
1954 	atomic_sub(skb->truesize, &sk->sk_omem_alloc);
1955 }
1956 
1957 struct sk_buff *sock_omalloc(struct sock *sk, unsigned long size,
1958 			     gfp_t priority)
1959 {
1960 	struct sk_buff *skb;
1961 
1962 	/* small safe race: SKB_TRUESIZE may differ from final skb->truesize */
1963 	if (atomic_read(&sk->sk_omem_alloc) + SKB_TRUESIZE(size) >
1964 	    sysctl_optmem_max)
1965 		return NULL;
1966 
1967 	skb = alloc_skb(size, priority);
1968 	if (!skb)
1969 		return NULL;
1970 
1971 	atomic_add(skb->truesize, &sk->sk_omem_alloc);
1972 	skb->sk = sk;
1973 	skb->destructor = sock_ofree;
1974 	return skb;
1975 }
1976 
1977 /*
1978  * Allocate a memory block from the socket's option memory buffer.
1979  */
1980 void *sock_kmalloc(struct sock *sk, int size, gfp_t priority)
1981 {
1982 	if ((unsigned int)size <= sysctl_optmem_max &&
1983 	    atomic_read(&sk->sk_omem_alloc) + size < sysctl_optmem_max) {
1984 		void *mem;
1985 		/* First do the add, to avoid the race if kmalloc
1986 		 * might sleep.
1987 		 */
1988 		atomic_add(size, &sk->sk_omem_alloc);
1989 		mem = kmalloc(size, priority);
1990 		if (mem)
1991 			return mem;
1992 		atomic_sub(size, &sk->sk_omem_alloc);
1993 	}
1994 	return NULL;
1995 }
1996 EXPORT_SYMBOL(sock_kmalloc);
1997 
1998 /* Free an option memory block. Note, we actually want the inline
1999  * here as this allows gcc to detect the nullify and fold away the
2000  * condition entirely.
2001  */
2002 static inline void __sock_kfree_s(struct sock *sk, void *mem, int size,
2003 				  const bool nullify)
2004 {
2005 	if (WARN_ON_ONCE(!mem))
2006 		return;
2007 	if (nullify)
2008 		kzfree(mem);
2009 	else
2010 		kfree(mem);
2011 	atomic_sub(size, &sk->sk_omem_alloc);
2012 }
2013 
2014 void sock_kfree_s(struct sock *sk, void *mem, int size)
2015 {
2016 	__sock_kfree_s(sk, mem, size, false);
2017 }
2018 EXPORT_SYMBOL(sock_kfree_s);
2019 
2020 void sock_kzfree_s(struct sock *sk, void *mem, int size)
2021 {
2022 	__sock_kfree_s(sk, mem, size, true);
2023 }
2024 EXPORT_SYMBOL(sock_kzfree_s);
2025 
2026 /* It is almost wait_for_tcp_memory minus release_sock/lock_sock.
2027    I think, these locks should be removed for datagram sockets.
2028  */
2029 static long sock_wait_for_wmem(struct sock *sk, long timeo)
2030 {
2031 	DEFINE_WAIT(wait);
2032 
2033 	sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
2034 	for (;;) {
2035 		if (!timeo)
2036 			break;
2037 		if (signal_pending(current))
2038 			break;
2039 		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
2040 		prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
2041 		if (refcount_read(&sk->sk_wmem_alloc) < sk->sk_sndbuf)
2042 			break;
2043 		if (sk->sk_shutdown & SEND_SHUTDOWN)
2044 			break;
2045 		if (sk->sk_err)
2046 			break;
2047 		timeo = schedule_timeout(timeo);
2048 	}
2049 	finish_wait(sk_sleep(sk), &wait);
2050 	return timeo;
2051 }
2052 
2053 
2054 /*
2055  *	Generic send/receive buffer handlers
2056  */
2057 
2058 struct sk_buff *sock_alloc_send_pskb(struct sock *sk, unsigned long header_len,
2059 				     unsigned long data_len, int noblock,
2060 				     int *errcode, int max_page_order)
2061 {
2062 	struct sk_buff *skb;
2063 	long timeo;
2064 	int err;
2065 
2066 	timeo = sock_sndtimeo(sk, noblock);
2067 	for (;;) {
2068 		err = sock_error(sk);
2069 		if (err != 0)
2070 			goto failure;
2071 
2072 		err = -EPIPE;
2073 		if (sk->sk_shutdown & SEND_SHUTDOWN)
2074 			goto failure;
2075 
2076 		if (sk_wmem_alloc_get(sk) < sk->sk_sndbuf)
2077 			break;
2078 
2079 		sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
2080 		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
2081 		err = -EAGAIN;
2082 		if (!timeo)
2083 			goto failure;
2084 		if (signal_pending(current))
2085 			goto interrupted;
2086 		timeo = sock_wait_for_wmem(sk, timeo);
2087 	}
2088 	skb = alloc_skb_with_frags(header_len, data_len, max_page_order,
2089 				   errcode, sk->sk_allocation);
2090 	if (skb)
2091 		skb_set_owner_w(skb, sk);
2092 	return skb;
2093 
2094 interrupted:
2095 	err = sock_intr_errno(timeo);
2096 failure:
2097 	*errcode = err;
2098 	return NULL;
2099 }
2100 EXPORT_SYMBOL(sock_alloc_send_pskb);
2101 
2102 struct sk_buff *sock_alloc_send_skb(struct sock *sk, unsigned long size,
2103 				    int noblock, int *errcode)
2104 {
2105 	return sock_alloc_send_pskb(sk, size, 0, noblock, errcode, 0);
2106 }
2107 EXPORT_SYMBOL(sock_alloc_send_skb);
2108 
2109 int __sock_cmsg_send(struct sock *sk, struct msghdr *msg, struct cmsghdr *cmsg,
2110 		     struct sockcm_cookie *sockc)
2111 {
2112 	u32 tsflags;
2113 
2114 	switch (cmsg->cmsg_type) {
2115 	case SO_MARK:
2116 		if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
2117 			return -EPERM;
2118 		if (cmsg->cmsg_len != CMSG_LEN(sizeof(u32)))
2119 			return -EINVAL;
2120 		sockc->mark = *(u32 *)CMSG_DATA(cmsg);
2121 		break;
2122 	case SO_TIMESTAMPING:
2123 		if (cmsg->cmsg_len != CMSG_LEN(sizeof(u32)))
2124 			return -EINVAL;
2125 
2126 		tsflags = *(u32 *)CMSG_DATA(cmsg);
2127 		if (tsflags & ~SOF_TIMESTAMPING_TX_RECORD_MASK)
2128 			return -EINVAL;
2129 
2130 		sockc->tsflags &= ~SOF_TIMESTAMPING_TX_RECORD_MASK;
2131 		sockc->tsflags |= tsflags;
2132 		break;
2133 	/* SCM_RIGHTS and SCM_CREDENTIALS are semantically in SOL_UNIX. */
2134 	case SCM_RIGHTS:
2135 	case SCM_CREDENTIALS:
2136 		break;
2137 	default:
2138 		return -EINVAL;
2139 	}
2140 	return 0;
2141 }
2142 EXPORT_SYMBOL(__sock_cmsg_send);
2143 
2144 int sock_cmsg_send(struct sock *sk, struct msghdr *msg,
2145 		   struct sockcm_cookie *sockc)
2146 {
2147 	struct cmsghdr *cmsg;
2148 	int ret;
2149 
2150 	for_each_cmsghdr(cmsg, msg) {
2151 		if (!CMSG_OK(msg, cmsg))
2152 			return -EINVAL;
2153 		if (cmsg->cmsg_level != SOL_SOCKET)
2154 			continue;
2155 		ret = __sock_cmsg_send(sk, msg, cmsg, sockc);
2156 		if (ret)
2157 			return ret;
2158 	}
2159 	return 0;
2160 }
2161 EXPORT_SYMBOL(sock_cmsg_send);
2162 
2163 static void sk_enter_memory_pressure(struct sock *sk)
2164 {
2165 	if (!sk->sk_prot->enter_memory_pressure)
2166 		return;
2167 
2168 	sk->sk_prot->enter_memory_pressure(sk);
2169 }
2170 
2171 static void sk_leave_memory_pressure(struct sock *sk)
2172 {
2173 	if (sk->sk_prot->leave_memory_pressure) {
2174 		sk->sk_prot->leave_memory_pressure(sk);
2175 	} else {
2176 		unsigned long *memory_pressure = sk->sk_prot->memory_pressure;
2177 
2178 		if (memory_pressure && *memory_pressure)
2179 			*memory_pressure = 0;
2180 	}
2181 }
2182 
2183 /* On 32bit arches, an skb frag is limited to 2^15 */
2184 #define SKB_FRAG_PAGE_ORDER	get_order(32768)
2185 
2186 /**
2187  * skb_page_frag_refill - check that a page_frag contains enough room
2188  * @sz: minimum size of the fragment we want to get
2189  * @pfrag: pointer to page_frag
2190  * @gfp: priority for memory allocation
2191  *
2192  * Note: While this allocator tries to use high order pages, there is
2193  * no guarantee that allocations succeed. Therefore, @sz MUST be
2194  * less or equal than PAGE_SIZE.
2195  */
2196 bool skb_page_frag_refill(unsigned int sz, struct page_frag *pfrag, gfp_t gfp)
2197 {
2198 	if (pfrag->page) {
2199 		if (page_ref_count(pfrag->page) == 1) {
2200 			pfrag->offset = 0;
2201 			return true;
2202 		}
2203 		if (pfrag->offset + sz <= pfrag->size)
2204 			return true;
2205 		put_page(pfrag->page);
2206 	}
2207 
2208 	pfrag->offset = 0;
2209 	if (SKB_FRAG_PAGE_ORDER) {
2210 		/* Avoid direct reclaim but allow kswapd to wake */
2211 		pfrag->page = alloc_pages((gfp & ~__GFP_DIRECT_RECLAIM) |
2212 					  __GFP_COMP | __GFP_NOWARN |
2213 					  __GFP_NORETRY,
2214 					  SKB_FRAG_PAGE_ORDER);
2215 		if (likely(pfrag->page)) {
2216 			pfrag->size = PAGE_SIZE << SKB_FRAG_PAGE_ORDER;
2217 			return true;
2218 		}
2219 	}
2220 	pfrag->page = alloc_page(gfp);
2221 	if (likely(pfrag->page)) {
2222 		pfrag->size = PAGE_SIZE;
2223 		return true;
2224 	}
2225 	return false;
2226 }
2227 EXPORT_SYMBOL(skb_page_frag_refill);
2228 
2229 bool sk_page_frag_refill(struct sock *sk, struct page_frag *pfrag)
2230 {
2231 	if (likely(skb_page_frag_refill(32U, pfrag, sk->sk_allocation)))
2232 		return true;
2233 
2234 	sk_enter_memory_pressure(sk);
2235 	sk_stream_moderate_sndbuf(sk);
2236 	return false;
2237 }
2238 EXPORT_SYMBOL(sk_page_frag_refill);
2239 
2240 int sk_alloc_sg(struct sock *sk, int len, struct scatterlist *sg,
2241 		int sg_start, int *sg_curr_index, unsigned int *sg_curr_size,
2242 		int first_coalesce)
2243 {
2244 	int sg_curr = *sg_curr_index, use = 0, rc = 0;
2245 	unsigned int size = *sg_curr_size;
2246 	struct page_frag *pfrag;
2247 	struct scatterlist *sge;
2248 
2249 	len -= size;
2250 	pfrag = sk_page_frag(sk);
2251 
2252 	while (len > 0) {
2253 		unsigned int orig_offset;
2254 
2255 		if (!sk_page_frag_refill(sk, pfrag)) {
2256 			rc = -ENOMEM;
2257 			goto out;
2258 		}
2259 
2260 		use = min_t(int, len, pfrag->size - pfrag->offset);
2261 
2262 		if (!sk_wmem_schedule(sk, use)) {
2263 			rc = -ENOMEM;
2264 			goto out;
2265 		}
2266 
2267 		sk_mem_charge(sk, use);
2268 		size += use;
2269 		orig_offset = pfrag->offset;
2270 		pfrag->offset += use;
2271 
2272 		sge = sg + sg_curr - 1;
2273 		if (sg_curr > first_coalesce && sg_page(sg) == pfrag->page &&
2274 		    sg->offset + sg->length == orig_offset) {
2275 			sg->length += use;
2276 		} else {
2277 			sge = sg + sg_curr;
2278 			sg_unmark_end(sge);
2279 			sg_set_page(sge, pfrag->page, use, orig_offset);
2280 			get_page(pfrag->page);
2281 			sg_curr++;
2282 
2283 			if (sg_curr == MAX_SKB_FRAGS)
2284 				sg_curr = 0;
2285 
2286 			if (sg_curr == sg_start) {
2287 				rc = -ENOSPC;
2288 				break;
2289 			}
2290 		}
2291 
2292 		len -= use;
2293 	}
2294 out:
2295 	*sg_curr_size = size;
2296 	*sg_curr_index = sg_curr;
2297 	return rc;
2298 }
2299 EXPORT_SYMBOL(sk_alloc_sg);
2300 
2301 static void __lock_sock(struct sock *sk)
2302 	__releases(&sk->sk_lock.slock)
2303 	__acquires(&sk->sk_lock.slock)
2304 {
2305 	DEFINE_WAIT(wait);
2306 
2307 	for (;;) {
2308 		prepare_to_wait_exclusive(&sk->sk_lock.wq, &wait,
2309 					TASK_UNINTERRUPTIBLE);
2310 		spin_unlock_bh(&sk->sk_lock.slock);
2311 		schedule();
2312 		spin_lock_bh(&sk->sk_lock.slock);
2313 		if (!sock_owned_by_user(sk))
2314 			break;
2315 	}
2316 	finish_wait(&sk->sk_lock.wq, &wait);
2317 }
2318 
2319 static void __release_sock(struct sock *sk)
2320 	__releases(&sk->sk_lock.slock)
2321 	__acquires(&sk->sk_lock.slock)
2322 {
2323 	struct sk_buff *skb, *next;
2324 
2325 	while ((skb = sk->sk_backlog.head) != NULL) {
2326 		sk->sk_backlog.head = sk->sk_backlog.tail = NULL;
2327 
2328 		spin_unlock_bh(&sk->sk_lock.slock);
2329 
2330 		do {
2331 			next = skb->next;
2332 			prefetch(next);
2333 			WARN_ON_ONCE(skb_dst_is_noref(skb));
2334 			skb->next = NULL;
2335 			sk_backlog_rcv(sk, skb);
2336 
2337 			cond_resched();
2338 
2339 			skb = next;
2340 		} while (skb != NULL);
2341 
2342 		spin_lock_bh(&sk->sk_lock.slock);
2343 	}
2344 
2345 	/*
2346 	 * Doing the zeroing here guarantee we can not loop forever
2347 	 * while a wild producer attempts to flood us.
2348 	 */
2349 	sk->sk_backlog.len = 0;
2350 }
2351 
2352 void __sk_flush_backlog(struct sock *sk)
2353 {
2354 	spin_lock_bh(&sk->sk_lock.slock);
2355 	__release_sock(sk);
2356 	spin_unlock_bh(&sk->sk_lock.slock);
2357 }
2358 
2359 /**
2360  * sk_wait_data - wait for data to arrive at sk_receive_queue
2361  * @sk:    sock to wait on
2362  * @timeo: for how long
2363  * @skb:   last skb seen on sk_receive_queue
2364  *
2365  * Now socket state including sk->sk_err is changed only under lock,
2366  * hence we may omit checks after joining wait queue.
2367  * We check receive queue before schedule() only as optimization;
2368  * it is very likely that release_sock() added new data.
2369  */
2370 int sk_wait_data(struct sock *sk, long *timeo, const struct sk_buff *skb)
2371 {
2372 	DEFINE_WAIT_FUNC(wait, woken_wake_function);
2373 	int rc;
2374 
2375 	add_wait_queue(sk_sleep(sk), &wait);
2376 	sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
2377 	rc = sk_wait_event(sk, timeo, skb_peek_tail(&sk->sk_receive_queue) != skb, &wait);
2378 	sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
2379 	remove_wait_queue(sk_sleep(sk), &wait);
2380 	return rc;
2381 }
2382 EXPORT_SYMBOL(sk_wait_data);
2383 
2384 /**
2385  *	__sk_mem_raise_allocated - increase memory_allocated
2386  *	@sk: socket
2387  *	@size: memory size to allocate
2388  *	@amt: pages to allocate
2389  *	@kind: allocation type
2390  *
2391  *	Similar to __sk_mem_schedule(), but does not update sk_forward_alloc
2392  */
2393 int __sk_mem_raise_allocated(struct sock *sk, int size, int amt, int kind)
2394 {
2395 	struct proto *prot = sk->sk_prot;
2396 	long allocated = sk_memory_allocated_add(sk, amt);
2397 
2398 	if (mem_cgroup_sockets_enabled && sk->sk_memcg &&
2399 	    !mem_cgroup_charge_skmem(sk->sk_memcg, amt))
2400 		goto suppress_allocation;
2401 
2402 	/* Under limit. */
2403 	if (allocated <= sk_prot_mem_limits(sk, 0)) {
2404 		sk_leave_memory_pressure(sk);
2405 		return 1;
2406 	}
2407 
2408 	/* Under pressure. */
2409 	if (allocated > sk_prot_mem_limits(sk, 1))
2410 		sk_enter_memory_pressure(sk);
2411 
2412 	/* Over hard limit. */
2413 	if (allocated > sk_prot_mem_limits(sk, 2))
2414 		goto suppress_allocation;
2415 
2416 	/* guarantee minimum buffer size under pressure */
2417 	if (kind == SK_MEM_RECV) {
2418 		if (atomic_read(&sk->sk_rmem_alloc) < sk_get_rmem0(sk, prot))
2419 			return 1;
2420 
2421 	} else { /* SK_MEM_SEND */
2422 		int wmem0 = sk_get_wmem0(sk, prot);
2423 
2424 		if (sk->sk_type == SOCK_STREAM) {
2425 			if (sk->sk_wmem_queued < wmem0)
2426 				return 1;
2427 		} else if (refcount_read(&sk->sk_wmem_alloc) < wmem0) {
2428 				return 1;
2429 		}
2430 	}
2431 
2432 	if (sk_has_memory_pressure(sk)) {
2433 		int alloc;
2434 
2435 		if (!sk_under_memory_pressure(sk))
2436 			return 1;
2437 		alloc = sk_sockets_allocated_read_positive(sk);
2438 		if (sk_prot_mem_limits(sk, 2) > alloc *
2439 		    sk_mem_pages(sk->sk_wmem_queued +
2440 				 atomic_read(&sk->sk_rmem_alloc) +
2441 				 sk->sk_forward_alloc))
2442 			return 1;
2443 	}
2444 
2445 suppress_allocation:
2446 
2447 	if (kind == SK_MEM_SEND && sk->sk_type == SOCK_STREAM) {
2448 		sk_stream_moderate_sndbuf(sk);
2449 
2450 		/* Fail only if socket is _under_ its sndbuf.
2451 		 * In this case we cannot block, so that we have to fail.
2452 		 */
2453 		if (sk->sk_wmem_queued + size >= sk->sk_sndbuf)
2454 			return 1;
2455 	}
2456 
2457 	trace_sock_exceed_buf_limit(sk, prot, allocated);
2458 
2459 	sk_memory_allocated_sub(sk, amt);
2460 
2461 	if (mem_cgroup_sockets_enabled && sk->sk_memcg)
2462 		mem_cgroup_uncharge_skmem(sk->sk_memcg, amt);
2463 
2464 	return 0;
2465 }
2466 EXPORT_SYMBOL(__sk_mem_raise_allocated);
2467 
2468 /**
2469  *	__sk_mem_schedule - increase sk_forward_alloc and memory_allocated
2470  *	@sk: socket
2471  *	@size: memory size to allocate
2472  *	@kind: allocation type
2473  *
2474  *	If kind is SK_MEM_SEND, it means wmem allocation. Otherwise it means
2475  *	rmem allocation. This function assumes that protocols which have
2476  *	memory_pressure use sk_wmem_queued as write buffer accounting.
2477  */
2478 int __sk_mem_schedule(struct sock *sk, int size, int kind)
2479 {
2480 	int ret, amt = sk_mem_pages(size);
2481 
2482 	sk->sk_forward_alloc += amt << SK_MEM_QUANTUM_SHIFT;
2483 	ret = __sk_mem_raise_allocated(sk, size, amt, kind);
2484 	if (!ret)
2485 		sk->sk_forward_alloc -= amt << SK_MEM_QUANTUM_SHIFT;
2486 	return ret;
2487 }
2488 EXPORT_SYMBOL(__sk_mem_schedule);
2489 
2490 /**
2491  *	__sk_mem_reduce_allocated - reclaim memory_allocated
2492  *	@sk: socket
2493  *	@amount: number of quanta
2494  *
2495  *	Similar to __sk_mem_reclaim(), but does not update sk_forward_alloc
2496  */
2497 void __sk_mem_reduce_allocated(struct sock *sk, int amount)
2498 {
2499 	sk_memory_allocated_sub(sk, amount);
2500 
2501 	if (mem_cgroup_sockets_enabled && sk->sk_memcg)
2502 		mem_cgroup_uncharge_skmem(sk->sk_memcg, amount);
2503 
2504 	if (sk_under_memory_pressure(sk) &&
2505 	    (sk_memory_allocated(sk) < sk_prot_mem_limits(sk, 0)))
2506 		sk_leave_memory_pressure(sk);
2507 }
2508 EXPORT_SYMBOL(__sk_mem_reduce_allocated);
2509 
2510 /**
2511  *	__sk_mem_reclaim - reclaim sk_forward_alloc and memory_allocated
2512  *	@sk: socket
2513  *	@amount: number of bytes (rounded down to a SK_MEM_QUANTUM multiple)
2514  */
2515 void __sk_mem_reclaim(struct sock *sk, int amount)
2516 {
2517 	amount >>= SK_MEM_QUANTUM_SHIFT;
2518 	sk->sk_forward_alloc -= amount << SK_MEM_QUANTUM_SHIFT;
2519 	__sk_mem_reduce_allocated(sk, amount);
2520 }
2521 EXPORT_SYMBOL(__sk_mem_reclaim);
2522 
2523 int sk_set_peek_off(struct sock *sk, int val)
2524 {
2525 	sk->sk_peek_off = val;
2526 	return 0;
2527 }
2528 EXPORT_SYMBOL_GPL(sk_set_peek_off);
2529 
2530 /*
2531  * Set of default routines for initialising struct proto_ops when
2532  * the protocol does not support a particular function. In certain
2533  * cases where it makes no sense for a protocol to have a "do nothing"
2534  * function, some default processing is provided.
2535  */
2536 
2537 int sock_no_bind(struct socket *sock, struct sockaddr *saddr, int len)
2538 {
2539 	return -EOPNOTSUPP;
2540 }
2541 EXPORT_SYMBOL(sock_no_bind);
2542 
2543 int sock_no_connect(struct socket *sock, struct sockaddr *saddr,
2544 		    int len, int flags)
2545 {
2546 	return -EOPNOTSUPP;
2547 }
2548 EXPORT_SYMBOL(sock_no_connect);
2549 
2550 int sock_no_socketpair(struct socket *sock1, struct socket *sock2)
2551 {
2552 	return -EOPNOTSUPP;
2553 }
2554 EXPORT_SYMBOL(sock_no_socketpair);
2555 
2556 int sock_no_accept(struct socket *sock, struct socket *newsock, int flags,
2557 		   bool kern)
2558 {
2559 	return -EOPNOTSUPP;
2560 }
2561 EXPORT_SYMBOL(sock_no_accept);
2562 
2563 int sock_no_getname(struct socket *sock, struct sockaddr *saddr,
2564 		    int peer)
2565 {
2566 	return -EOPNOTSUPP;
2567 }
2568 EXPORT_SYMBOL(sock_no_getname);
2569 
2570 __poll_t sock_no_poll(struct file *file, struct socket *sock, poll_table *pt)
2571 {
2572 	return 0;
2573 }
2574 EXPORT_SYMBOL(sock_no_poll);
2575 
2576 int sock_no_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
2577 {
2578 	return -EOPNOTSUPP;
2579 }
2580 EXPORT_SYMBOL(sock_no_ioctl);
2581 
2582 int sock_no_listen(struct socket *sock, int backlog)
2583 {
2584 	return -EOPNOTSUPP;
2585 }
2586 EXPORT_SYMBOL(sock_no_listen);
2587 
2588 int sock_no_shutdown(struct socket *sock, int how)
2589 {
2590 	return -EOPNOTSUPP;
2591 }
2592 EXPORT_SYMBOL(sock_no_shutdown);
2593 
2594 int sock_no_setsockopt(struct socket *sock, int level, int optname,
2595 		    char __user *optval, unsigned int optlen)
2596 {
2597 	return -EOPNOTSUPP;
2598 }
2599 EXPORT_SYMBOL(sock_no_setsockopt);
2600 
2601 int sock_no_getsockopt(struct socket *sock, int level, int optname,
2602 		    char __user *optval, int __user *optlen)
2603 {
2604 	return -EOPNOTSUPP;
2605 }
2606 EXPORT_SYMBOL(sock_no_getsockopt);
2607 
2608 int sock_no_sendmsg(struct socket *sock, struct msghdr *m, size_t len)
2609 {
2610 	return -EOPNOTSUPP;
2611 }
2612 EXPORT_SYMBOL(sock_no_sendmsg);
2613 
2614 int sock_no_sendmsg_locked(struct sock *sk, struct msghdr *m, size_t len)
2615 {
2616 	return -EOPNOTSUPP;
2617 }
2618 EXPORT_SYMBOL(sock_no_sendmsg_locked);
2619 
2620 int sock_no_recvmsg(struct socket *sock, struct msghdr *m, size_t len,
2621 		    int flags)
2622 {
2623 	return -EOPNOTSUPP;
2624 }
2625 EXPORT_SYMBOL(sock_no_recvmsg);
2626 
2627 int sock_no_mmap(struct file *file, struct socket *sock, struct vm_area_struct *vma)
2628 {
2629 	/* Mirror missing mmap method error code */
2630 	return -ENODEV;
2631 }
2632 EXPORT_SYMBOL(sock_no_mmap);
2633 
2634 ssize_t sock_no_sendpage(struct socket *sock, struct page *page, int offset, size_t size, int flags)
2635 {
2636 	ssize_t res;
2637 	struct msghdr msg = {.msg_flags = flags};
2638 	struct kvec iov;
2639 	char *kaddr = kmap(page);
2640 	iov.iov_base = kaddr + offset;
2641 	iov.iov_len = size;
2642 	res = kernel_sendmsg(sock, &msg, &iov, 1, size);
2643 	kunmap(page);
2644 	return res;
2645 }
2646 EXPORT_SYMBOL(sock_no_sendpage);
2647 
2648 ssize_t sock_no_sendpage_locked(struct sock *sk, struct page *page,
2649 				int offset, size_t size, int flags)
2650 {
2651 	ssize_t res;
2652 	struct msghdr msg = {.msg_flags = flags};
2653 	struct kvec iov;
2654 	char *kaddr = kmap(page);
2655 
2656 	iov.iov_base = kaddr + offset;
2657 	iov.iov_len = size;
2658 	res = kernel_sendmsg_locked(sk, &msg, &iov, 1, size);
2659 	kunmap(page);
2660 	return res;
2661 }
2662 EXPORT_SYMBOL(sock_no_sendpage_locked);
2663 
2664 /*
2665  *	Default Socket Callbacks
2666  */
2667 
2668 static void sock_def_wakeup(struct sock *sk)
2669 {
2670 	struct socket_wq *wq;
2671 
2672 	rcu_read_lock();
2673 	wq = rcu_dereference(sk->sk_wq);
2674 	if (skwq_has_sleeper(wq))
2675 		wake_up_interruptible_all(&wq->wait);
2676 	rcu_read_unlock();
2677 }
2678 
2679 static void sock_def_error_report(struct sock *sk)
2680 {
2681 	struct socket_wq *wq;
2682 
2683 	rcu_read_lock();
2684 	wq = rcu_dereference(sk->sk_wq);
2685 	if (skwq_has_sleeper(wq))
2686 		wake_up_interruptible_poll(&wq->wait, EPOLLERR);
2687 	sk_wake_async(sk, SOCK_WAKE_IO, POLL_ERR);
2688 	rcu_read_unlock();
2689 }
2690 
2691 static void sock_def_readable(struct sock *sk)
2692 {
2693 	struct socket_wq *wq;
2694 
2695 	rcu_read_lock();
2696 	wq = rcu_dereference(sk->sk_wq);
2697 	if (skwq_has_sleeper(wq))
2698 		wake_up_interruptible_sync_poll(&wq->wait, EPOLLIN | EPOLLPRI |
2699 						EPOLLRDNORM | EPOLLRDBAND);
2700 	sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
2701 	rcu_read_unlock();
2702 }
2703 
2704 static void sock_def_write_space(struct sock *sk)
2705 {
2706 	struct socket_wq *wq;
2707 
2708 	rcu_read_lock();
2709 
2710 	/* Do not wake up a writer until he can make "significant"
2711 	 * progress.  --DaveM
2712 	 */
2713 	if ((refcount_read(&sk->sk_wmem_alloc) << 1) <= sk->sk_sndbuf) {
2714 		wq = rcu_dereference(sk->sk_wq);
2715 		if (skwq_has_sleeper(wq))
2716 			wake_up_interruptible_sync_poll(&wq->wait, EPOLLOUT |
2717 						EPOLLWRNORM | EPOLLWRBAND);
2718 
2719 		/* Should agree with poll, otherwise some programs break */
2720 		if (sock_writeable(sk))
2721 			sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
2722 	}
2723 
2724 	rcu_read_unlock();
2725 }
2726 
2727 static void sock_def_destruct(struct sock *sk)
2728 {
2729 }
2730 
2731 void sk_send_sigurg(struct sock *sk)
2732 {
2733 	if (sk->sk_socket && sk->sk_socket->file)
2734 		if (send_sigurg(&sk->sk_socket->file->f_owner))
2735 			sk_wake_async(sk, SOCK_WAKE_URG, POLL_PRI);
2736 }
2737 EXPORT_SYMBOL(sk_send_sigurg);
2738 
2739 void sk_reset_timer(struct sock *sk, struct timer_list* timer,
2740 		    unsigned long expires)
2741 {
2742 	if (!mod_timer(timer, expires))
2743 		sock_hold(sk);
2744 }
2745 EXPORT_SYMBOL(sk_reset_timer);
2746 
2747 void sk_stop_timer(struct sock *sk, struct timer_list* timer)
2748 {
2749 	if (del_timer(timer))
2750 		__sock_put(sk);
2751 }
2752 EXPORT_SYMBOL(sk_stop_timer);
2753 
2754 void sock_init_data(struct socket *sock, struct sock *sk)
2755 {
2756 	sk_init_common(sk);
2757 	sk->sk_send_head	=	NULL;
2758 
2759 	timer_setup(&sk->sk_timer, NULL, 0);
2760 
2761 	sk->sk_allocation	=	GFP_KERNEL;
2762 	sk->sk_rcvbuf		=	sysctl_rmem_default;
2763 	sk->sk_sndbuf		=	sysctl_wmem_default;
2764 	sk->sk_state		=	TCP_CLOSE;
2765 	sk_set_socket(sk, sock);
2766 
2767 	sock_set_flag(sk, SOCK_ZAPPED);
2768 
2769 	if (sock) {
2770 		sk->sk_type	=	sock->type;
2771 		sk->sk_wq	=	sock->wq;
2772 		sock->sk	=	sk;
2773 		sk->sk_uid	=	SOCK_INODE(sock)->i_uid;
2774 	} else {
2775 		sk->sk_wq	=	NULL;
2776 		sk->sk_uid	=	make_kuid(sock_net(sk)->user_ns, 0);
2777 	}
2778 
2779 	rwlock_init(&sk->sk_callback_lock);
2780 	if (sk->sk_kern_sock)
2781 		lockdep_set_class_and_name(
2782 			&sk->sk_callback_lock,
2783 			af_kern_callback_keys + sk->sk_family,
2784 			af_family_kern_clock_key_strings[sk->sk_family]);
2785 	else
2786 		lockdep_set_class_and_name(
2787 			&sk->sk_callback_lock,
2788 			af_callback_keys + sk->sk_family,
2789 			af_family_clock_key_strings[sk->sk_family]);
2790 
2791 	sk->sk_state_change	=	sock_def_wakeup;
2792 	sk->sk_data_ready	=	sock_def_readable;
2793 	sk->sk_write_space	=	sock_def_write_space;
2794 	sk->sk_error_report	=	sock_def_error_report;
2795 	sk->sk_destruct		=	sock_def_destruct;
2796 
2797 	sk->sk_frag.page	=	NULL;
2798 	sk->sk_frag.offset	=	0;
2799 	sk->sk_peek_off		=	-1;
2800 
2801 	sk->sk_peer_pid 	=	NULL;
2802 	sk->sk_peer_cred	=	NULL;
2803 	sk->sk_write_pending	=	0;
2804 	sk->sk_rcvlowat		=	1;
2805 	sk->sk_rcvtimeo		=	MAX_SCHEDULE_TIMEOUT;
2806 	sk->sk_sndtimeo		=	MAX_SCHEDULE_TIMEOUT;
2807 
2808 	sk->sk_stamp = SK_DEFAULT_STAMP;
2809 	atomic_set(&sk->sk_zckey, 0);
2810 
2811 #ifdef CONFIG_NET_RX_BUSY_POLL
2812 	sk->sk_napi_id		=	0;
2813 	sk->sk_ll_usec		=	sysctl_net_busy_read;
2814 #endif
2815 
2816 	sk->sk_max_pacing_rate = ~0U;
2817 	sk->sk_pacing_rate = ~0U;
2818 	sk->sk_pacing_shift = 10;
2819 	sk->sk_incoming_cpu = -1;
2820 	/*
2821 	 * Before updating sk_refcnt, we must commit prior changes to memory
2822 	 * (Documentation/RCU/rculist_nulls.txt for details)
2823 	 */
2824 	smp_wmb();
2825 	refcount_set(&sk->sk_refcnt, 1);
2826 	atomic_set(&sk->sk_drops, 0);
2827 }
2828 EXPORT_SYMBOL(sock_init_data);
2829 
2830 void lock_sock_nested(struct sock *sk, int subclass)
2831 {
2832 	might_sleep();
2833 	spin_lock_bh(&sk->sk_lock.slock);
2834 	if (sk->sk_lock.owned)
2835 		__lock_sock(sk);
2836 	sk->sk_lock.owned = 1;
2837 	spin_unlock(&sk->sk_lock.slock);
2838 	/*
2839 	 * The sk_lock has mutex_lock() semantics here:
2840 	 */
2841 	mutex_acquire(&sk->sk_lock.dep_map, subclass, 0, _RET_IP_);
2842 	local_bh_enable();
2843 }
2844 EXPORT_SYMBOL(lock_sock_nested);
2845 
2846 void release_sock(struct sock *sk)
2847 {
2848 	spin_lock_bh(&sk->sk_lock.slock);
2849 	if (sk->sk_backlog.tail)
2850 		__release_sock(sk);
2851 
2852 	/* Warning : release_cb() might need to release sk ownership,
2853 	 * ie call sock_release_ownership(sk) before us.
2854 	 */
2855 	if (sk->sk_prot->release_cb)
2856 		sk->sk_prot->release_cb(sk);
2857 
2858 	sock_release_ownership(sk);
2859 	if (waitqueue_active(&sk->sk_lock.wq))
2860 		wake_up(&sk->sk_lock.wq);
2861 	spin_unlock_bh(&sk->sk_lock.slock);
2862 }
2863 EXPORT_SYMBOL(release_sock);
2864 
2865 /**
2866  * lock_sock_fast - fast version of lock_sock
2867  * @sk: socket
2868  *
2869  * This version should be used for very small section, where process wont block
2870  * return false if fast path is taken:
2871  *
2872  *   sk_lock.slock locked, owned = 0, BH disabled
2873  *
2874  * return true if slow path is taken:
2875  *
2876  *   sk_lock.slock unlocked, owned = 1, BH enabled
2877  */
2878 bool lock_sock_fast(struct sock *sk)
2879 {
2880 	might_sleep();
2881 	spin_lock_bh(&sk->sk_lock.slock);
2882 
2883 	if (!sk->sk_lock.owned)
2884 		/*
2885 		 * Note : We must disable BH
2886 		 */
2887 		return false;
2888 
2889 	__lock_sock(sk);
2890 	sk->sk_lock.owned = 1;
2891 	spin_unlock(&sk->sk_lock.slock);
2892 	/*
2893 	 * The sk_lock has mutex_lock() semantics here:
2894 	 */
2895 	mutex_acquire(&sk->sk_lock.dep_map, 0, 0, _RET_IP_);
2896 	local_bh_enable();
2897 	return true;
2898 }
2899 EXPORT_SYMBOL(lock_sock_fast);
2900 
2901 int sock_get_timestamp(struct sock *sk, struct timeval __user *userstamp)
2902 {
2903 	struct timeval tv;
2904 	if (!sock_flag(sk, SOCK_TIMESTAMP))
2905 		sock_enable_timestamp(sk, SOCK_TIMESTAMP);
2906 	tv = ktime_to_timeval(sk->sk_stamp);
2907 	if (tv.tv_sec == -1)
2908 		return -ENOENT;
2909 	if (tv.tv_sec == 0) {
2910 		sk->sk_stamp = ktime_get_real();
2911 		tv = ktime_to_timeval(sk->sk_stamp);
2912 	}
2913 	return copy_to_user(userstamp, &tv, sizeof(tv)) ? -EFAULT : 0;
2914 }
2915 EXPORT_SYMBOL(sock_get_timestamp);
2916 
2917 int sock_get_timestampns(struct sock *sk, struct timespec __user *userstamp)
2918 {
2919 	struct timespec ts;
2920 	if (!sock_flag(sk, SOCK_TIMESTAMP))
2921 		sock_enable_timestamp(sk, SOCK_TIMESTAMP);
2922 	ts = ktime_to_timespec(sk->sk_stamp);
2923 	if (ts.tv_sec == -1)
2924 		return -ENOENT;
2925 	if (ts.tv_sec == 0) {
2926 		sk->sk_stamp = ktime_get_real();
2927 		ts = ktime_to_timespec(sk->sk_stamp);
2928 	}
2929 	return copy_to_user(userstamp, &ts, sizeof(ts)) ? -EFAULT : 0;
2930 }
2931 EXPORT_SYMBOL(sock_get_timestampns);
2932 
2933 void sock_enable_timestamp(struct sock *sk, int flag)
2934 {
2935 	if (!sock_flag(sk, flag)) {
2936 		unsigned long previous_flags = sk->sk_flags;
2937 
2938 		sock_set_flag(sk, flag);
2939 		/*
2940 		 * we just set one of the two flags which require net
2941 		 * time stamping, but time stamping might have been on
2942 		 * already because of the other one
2943 		 */
2944 		if (sock_needs_netstamp(sk) &&
2945 		    !(previous_flags & SK_FLAGS_TIMESTAMP))
2946 			net_enable_timestamp();
2947 	}
2948 }
2949 
2950 int sock_recv_errqueue(struct sock *sk, struct msghdr *msg, int len,
2951 		       int level, int type)
2952 {
2953 	struct sock_exterr_skb *serr;
2954 	struct sk_buff *skb;
2955 	int copied, err;
2956 
2957 	err = -EAGAIN;
2958 	skb = sock_dequeue_err_skb(sk);
2959 	if (skb == NULL)
2960 		goto out;
2961 
2962 	copied = skb->len;
2963 	if (copied > len) {
2964 		msg->msg_flags |= MSG_TRUNC;
2965 		copied = len;
2966 	}
2967 	err = skb_copy_datagram_msg(skb, 0, msg, copied);
2968 	if (err)
2969 		goto out_free_skb;
2970 
2971 	sock_recv_timestamp(msg, sk, skb);
2972 
2973 	serr = SKB_EXT_ERR(skb);
2974 	put_cmsg(msg, level, type, sizeof(serr->ee), &serr->ee);
2975 
2976 	msg->msg_flags |= MSG_ERRQUEUE;
2977 	err = copied;
2978 
2979 out_free_skb:
2980 	kfree_skb(skb);
2981 out:
2982 	return err;
2983 }
2984 EXPORT_SYMBOL(sock_recv_errqueue);
2985 
2986 /*
2987  *	Get a socket option on an socket.
2988  *
2989  *	FIX: POSIX 1003.1g is very ambiguous here. It states that
2990  *	asynchronous errors should be reported by getsockopt. We assume
2991  *	this means if you specify SO_ERROR (otherwise whats the point of it).
2992  */
2993 int sock_common_getsockopt(struct socket *sock, int level, int optname,
2994 			   char __user *optval, int __user *optlen)
2995 {
2996 	struct sock *sk = sock->sk;
2997 
2998 	return sk->sk_prot->getsockopt(sk, level, optname, optval, optlen);
2999 }
3000 EXPORT_SYMBOL(sock_common_getsockopt);
3001 
3002 #ifdef CONFIG_COMPAT
3003 int compat_sock_common_getsockopt(struct socket *sock, int level, int optname,
3004 				  char __user *optval, int __user *optlen)
3005 {
3006 	struct sock *sk = sock->sk;
3007 
3008 	if (sk->sk_prot->compat_getsockopt != NULL)
3009 		return sk->sk_prot->compat_getsockopt(sk, level, optname,
3010 						      optval, optlen);
3011 	return sk->sk_prot->getsockopt(sk, level, optname, optval, optlen);
3012 }
3013 EXPORT_SYMBOL(compat_sock_common_getsockopt);
3014 #endif
3015 
3016 int sock_common_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
3017 			int flags)
3018 {
3019 	struct sock *sk = sock->sk;
3020 	int addr_len = 0;
3021 	int err;
3022 
3023 	err = sk->sk_prot->recvmsg(sk, msg, size, flags & MSG_DONTWAIT,
3024 				   flags & ~MSG_DONTWAIT, &addr_len);
3025 	if (err >= 0)
3026 		msg->msg_namelen = addr_len;
3027 	return err;
3028 }
3029 EXPORT_SYMBOL(sock_common_recvmsg);
3030 
3031 /*
3032  *	Set socket options on an inet socket.
3033  */
3034 int sock_common_setsockopt(struct socket *sock, int level, int optname,
3035 			   char __user *optval, unsigned int optlen)
3036 {
3037 	struct sock *sk = sock->sk;
3038 
3039 	return sk->sk_prot->setsockopt(sk, level, optname, optval, optlen);
3040 }
3041 EXPORT_SYMBOL(sock_common_setsockopt);
3042 
3043 #ifdef CONFIG_COMPAT
3044 int compat_sock_common_setsockopt(struct socket *sock, int level, int optname,
3045 				  char __user *optval, unsigned int optlen)
3046 {
3047 	struct sock *sk = sock->sk;
3048 
3049 	if (sk->sk_prot->compat_setsockopt != NULL)
3050 		return sk->sk_prot->compat_setsockopt(sk, level, optname,
3051 						      optval, optlen);
3052 	return sk->sk_prot->setsockopt(sk, level, optname, optval, optlen);
3053 }
3054 EXPORT_SYMBOL(compat_sock_common_setsockopt);
3055 #endif
3056 
3057 void sk_common_release(struct sock *sk)
3058 {
3059 	if (sk->sk_prot->destroy)
3060 		sk->sk_prot->destroy(sk);
3061 
3062 	/*
3063 	 * Observation: when sock_common_release is called, processes have
3064 	 * no access to socket. But net still has.
3065 	 * Step one, detach it from networking:
3066 	 *
3067 	 * A. Remove from hash tables.
3068 	 */
3069 
3070 	sk->sk_prot->unhash(sk);
3071 
3072 	/*
3073 	 * In this point socket cannot receive new packets, but it is possible
3074 	 * that some packets are in flight because some CPU runs receiver and
3075 	 * did hash table lookup before we unhashed socket. They will achieve
3076 	 * receive queue and will be purged by socket destructor.
3077 	 *
3078 	 * Also we still have packets pending on receive queue and probably,
3079 	 * our own packets waiting in device queues. sock_destroy will drain
3080 	 * receive queue, but transmitted packets will delay socket destruction
3081 	 * until the last reference will be released.
3082 	 */
3083 
3084 	sock_orphan(sk);
3085 
3086 	xfrm_sk_free_policy(sk);
3087 
3088 	sk_refcnt_debug_release(sk);
3089 
3090 	sock_put(sk);
3091 }
3092 EXPORT_SYMBOL(sk_common_release);
3093 
3094 void sk_get_meminfo(const struct sock *sk, u32 *mem)
3095 {
3096 	memset(mem, 0, sizeof(*mem) * SK_MEMINFO_VARS);
3097 
3098 	mem[SK_MEMINFO_RMEM_ALLOC] = sk_rmem_alloc_get(sk);
3099 	mem[SK_MEMINFO_RCVBUF] = sk->sk_rcvbuf;
3100 	mem[SK_MEMINFO_WMEM_ALLOC] = sk_wmem_alloc_get(sk);
3101 	mem[SK_MEMINFO_SNDBUF] = sk->sk_sndbuf;
3102 	mem[SK_MEMINFO_FWD_ALLOC] = sk->sk_forward_alloc;
3103 	mem[SK_MEMINFO_WMEM_QUEUED] = sk->sk_wmem_queued;
3104 	mem[SK_MEMINFO_OPTMEM] = atomic_read(&sk->sk_omem_alloc);
3105 	mem[SK_MEMINFO_BACKLOG] = sk->sk_backlog.len;
3106 	mem[SK_MEMINFO_DROPS] = atomic_read(&sk->sk_drops);
3107 }
3108 
3109 #ifdef CONFIG_PROC_FS
3110 #define PROTO_INUSE_NR	64	/* should be enough for the first time */
3111 struct prot_inuse {
3112 	int val[PROTO_INUSE_NR];
3113 };
3114 
3115 static DECLARE_BITMAP(proto_inuse_idx, PROTO_INUSE_NR);
3116 
3117 void sock_prot_inuse_add(struct net *net, struct proto *prot, int val)
3118 {
3119 	__this_cpu_add(net->core.prot_inuse->val[prot->inuse_idx], val);
3120 }
3121 EXPORT_SYMBOL_GPL(sock_prot_inuse_add);
3122 
3123 int sock_prot_inuse_get(struct net *net, struct proto *prot)
3124 {
3125 	int cpu, idx = prot->inuse_idx;
3126 	int res = 0;
3127 
3128 	for_each_possible_cpu(cpu)
3129 		res += per_cpu_ptr(net->core.prot_inuse, cpu)->val[idx];
3130 
3131 	return res >= 0 ? res : 0;
3132 }
3133 EXPORT_SYMBOL_GPL(sock_prot_inuse_get);
3134 
3135 static void sock_inuse_add(struct net *net, int val)
3136 {
3137 	this_cpu_add(*net->core.sock_inuse, val);
3138 }
3139 
3140 int sock_inuse_get(struct net *net)
3141 {
3142 	int cpu, res = 0;
3143 
3144 	for_each_possible_cpu(cpu)
3145 		res += *per_cpu_ptr(net->core.sock_inuse, cpu);
3146 
3147 	return res;
3148 }
3149 
3150 EXPORT_SYMBOL_GPL(sock_inuse_get);
3151 
3152 static int __net_init sock_inuse_init_net(struct net *net)
3153 {
3154 	net->core.prot_inuse = alloc_percpu(struct prot_inuse);
3155 	if (net->core.prot_inuse == NULL)
3156 		return -ENOMEM;
3157 
3158 	net->core.sock_inuse = alloc_percpu(int);
3159 	if (net->core.sock_inuse == NULL)
3160 		goto out;
3161 
3162 	return 0;
3163 
3164 out:
3165 	free_percpu(net->core.prot_inuse);
3166 	return -ENOMEM;
3167 }
3168 
3169 static void __net_exit sock_inuse_exit_net(struct net *net)
3170 {
3171 	free_percpu(net->core.prot_inuse);
3172 	free_percpu(net->core.sock_inuse);
3173 }
3174 
3175 static struct pernet_operations net_inuse_ops = {
3176 	.init = sock_inuse_init_net,
3177 	.exit = sock_inuse_exit_net,
3178 };
3179 
3180 static __init int net_inuse_init(void)
3181 {
3182 	if (register_pernet_subsys(&net_inuse_ops))
3183 		panic("Cannot initialize net inuse counters");
3184 
3185 	return 0;
3186 }
3187 
3188 core_initcall(net_inuse_init);
3189 
3190 static void assign_proto_idx(struct proto *prot)
3191 {
3192 	prot->inuse_idx = find_first_zero_bit(proto_inuse_idx, PROTO_INUSE_NR);
3193 
3194 	if (unlikely(prot->inuse_idx == PROTO_INUSE_NR - 1)) {
3195 		pr_err("PROTO_INUSE_NR exhausted\n");
3196 		return;
3197 	}
3198 
3199 	set_bit(prot->inuse_idx, proto_inuse_idx);
3200 }
3201 
3202 static void release_proto_idx(struct proto *prot)
3203 {
3204 	if (prot->inuse_idx != PROTO_INUSE_NR - 1)
3205 		clear_bit(prot->inuse_idx, proto_inuse_idx);
3206 }
3207 #else
3208 static inline void assign_proto_idx(struct proto *prot)
3209 {
3210 }
3211 
3212 static inline void release_proto_idx(struct proto *prot)
3213 {
3214 }
3215 
3216 static void sock_inuse_add(struct net *net, int val)
3217 {
3218 }
3219 #endif
3220 
3221 static void req_prot_cleanup(struct request_sock_ops *rsk_prot)
3222 {
3223 	if (!rsk_prot)
3224 		return;
3225 	kfree(rsk_prot->slab_name);
3226 	rsk_prot->slab_name = NULL;
3227 	kmem_cache_destroy(rsk_prot->slab);
3228 	rsk_prot->slab = NULL;
3229 }
3230 
3231 static int req_prot_init(const struct proto *prot)
3232 {
3233 	struct request_sock_ops *rsk_prot = prot->rsk_prot;
3234 
3235 	if (!rsk_prot)
3236 		return 0;
3237 
3238 	rsk_prot->slab_name = kasprintf(GFP_KERNEL, "request_sock_%s",
3239 					prot->name);
3240 	if (!rsk_prot->slab_name)
3241 		return -ENOMEM;
3242 
3243 	rsk_prot->slab = kmem_cache_create(rsk_prot->slab_name,
3244 					   rsk_prot->obj_size, 0,
3245 					   prot->slab_flags, NULL);
3246 
3247 	if (!rsk_prot->slab) {
3248 		pr_crit("%s: Can't create request sock SLAB cache!\n",
3249 			prot->name);
3250 		return -ENOMEM;
3251 	}
3252 	return 0;
3253 }
3254 
3255 int proto_register(struct proto *prot, int alloc_slab)
3256 {
3257 	if (alloc_slab) {
3258 		prot->slab = kmem_cache_create_usercopy(prot->name,
3259 					prot->obj_size, 0,
3260 					SLAB_HWCACHE_ALIGN | prot->slab_flags,
3261 					prot->useroffset, prot->usersize,
3262 					NULL);
3263 
3264 		if (prot->slab == NULL) {
3265 			pr_crit("%s: Can't create sock SLAB cache!\n",
3266 				prot->name);
3267 			goto out;
3268 		}
3269 
3270 		if (req_prot_init(prot))
3271 			goto out_free_request_sock_slab;
3272 
3273 		if (prot->twsk_prot != NULL) {
3274 			prot->twsk_prot->twsk_slab_name = kasprintf(GFP_KERNEL, "tw_sock_%s", prot->name);
3275 
3276 			if (prot->twsk_prot->twsk_slab_name == NULL)
3277 				goto out_free_request_sock_slab;
3278 
3279 			prot->twsk_prot->twsk_slab =
3280 				kmem_cache_create(prot->twsk_prot->twsk_slab_name,
3281 						  prot->twsk_prot->twsk_obj_size,
3282 						  0,
3283 						  prot->slab_flags,
3284 						  NULL);
3285 			if (prot->twsk_prot->twsk_slab == NULL)
3286 				goto out_free_timewait_sock_slab_name;
3287 		}
3288 	}
3289 
3290 	mutex_lock(&proto_list_mutex);
3291 	list_add(&prot->node, &proto_list);
3292 	assign_proto_idx(prot);
3293 	mutex_unlock(&proto_list_mutex);
3294 	return 0;
3295 
3296 out_free_timewait_sock_slab_name:
3297 	kfree(prot->twsk_prot->twsk_slab_name);
3298 out_free_request_sock_slab:
3299 	req_prot_cleanup(prot->rsk_prot);
3300 
3301 	kmem_cache_destroy(prot->slab);
3302 	prot->slab = NULL;
3303 out:
3304 	return -ENOBUFS;
3305 }
3306 EXPORT_SYMBOL(proto_register);
3307 
3308 void proto_unregister(struct proto *prot)
3309 {
3310 	mutex_lock(&proto_list_mutex);
3311 	release_proto_idx(prot);
3312 	list_del(&prot->node);
3313 	mutex_unlock(&proto_list_mutex);
3314 
3315 	kmem_cache_destroy(prot->slab);
3316 	prot->slab = NULL;
3317 
3318 	req_prot_cleanup(prot->rsk_prot);
3319 
3320 	if (prot->twsk_prot != NULL && prot->twsk_prot->twsk_slab != NULL) {
3321 		kmem_cache_destroy(prot->twsk_prot->twsk_slab);
3322 		kfree(prot->twsk_prot->twsk_slab_name);
3323 		prot->twsk_prot->twsk_slab = NULL;
3324 	}
3325 }
3326 EXPORT_SYMBOL(proto_unregister);
3327 
3328 int sock_load_diag_module(int family, int protocol)
3329 {
3330 	if (!protocol) {
3331 		if (!sock_is_registered(family))
3332 			return -ENOENT;
3333 
3334 		return request_module("net-pf-%d-proto-%d-type-%d", PF_NETLINK,
3335 				      NETLINK_SOCK_DIAG, family);
3336 	}
3337 
3338 #ifdef CONFIG_INET
3339 	if (family == AF_INET &&
3340 	    !rcu_access_pointer(inet_protos[protocol]))
3341 		return -ENOENT;
3342 #endif
3343 
3344 	return request_module("net-pf-%d-proto-%d-type-%d-%d", PF_NETLINK,
3345 			      NETLINK_SOCK_DIAG, family, protocol);
3346 }
3347 EXPORT_SYMBOL(sock_load_diag_module);
3348 
3349 #ifdef CONFIG_PROC_FS
3350 static void *proto_seq_start(struct seq_file *seq, loff_t *pos)
3351 	__acquires(proto_list_mutex)
3352 {
3353 	mutex_lock(&proto_list_mutex);
3354 	return seq_list_start_head(&proto_list, *pos);
3355 }
3356 
3357 static void *proto_seq_next(struct seq_file *seq, void *v, loff_t *pos)
3358 {
3359 	return seq_list_next(v, &proto_list, pos);
3360 }
3361 
3362 static void proto_seq_stop(struct seq_file *seq, void *v)
3363 	__releases(proto_list_mutex)
3364 {
3365 	mutex_unlock(&proto_list_mutex);
3366 }
3367 
3368 static char proto_method_implemented(const void *method)
3369 {
3370 	return method == NULL ? 'n' : 'y';
3371 }
3372 static long sock_prot_memory_allocated(struct proto *proto)
3373 {
3374 	return proto->memory_allocated != NULL ? proto_memory_allocated(proto) : -1L;
3375 }
3376 
3377 static char *sock_prot_memory_pressure(struct proto *proto)
3378 {
3379 	return proto->memory_pressure != NULL ?
3380 	proto_memory_pressure(proto) ? "yes" : "no" : "NI";
3381 }
3382 
3383 static void proto_seq_printf(struct seq_file *seq, struct proto *proto)
3384 {
3385 
3386 	seq_printf(seq, "%-9s %4u %6d  %6ld   %-3s %6u   %-3s  %-10s "
3387 			"%2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c\n",
3388 		   proto->name,
3389 		   proto->obj_size,
3390 		   sock_prot_inuse_get(seq_file_net(seq), proto),
3391 		   sock_prot_memory_allocated(proto),
3392 		   sock_prot_memory_pressure(proto),
3393 		   proto->max_header,
3394 		   proto->slab == NULL ? "no" : "yes",
3395 		   module_name(proto->owner),
3396 		   proto_method_implemented(proto->close),
3397 		   proto_method_implemented(proto->connect),
3398 		   proto_method_implemented(proto->disconnect),
3399 		   proto_method_implemented(proto->accept),
3400 		   proto_method_implemented(proto->ioctl),
3401 		   proto_method_implemented(proto->init),
3402 		   proto_method_implemented(proto->destroy),
3403 		   proto_method_implemented(proto->shutdown),
3404 		   proto_method_implemented(proto->setsockopt),
3405 		   proto_method_implemented(proto->getsockopt),
3406 		   proto_method_implemented(proto->sendmsg),
3407 		   proto_method_implemented(proto->recvmsg),
3408 		   proto_method_implemented(proto->sendpage),
3409 		   proto_method_implemented(proto->bind),
3410 		   proto_method_implemented(proto->backlog_rcv),
3411 		   proto_method_implemented(proto->hash),
3412 		   proto_method_implemented(proto->unhash),
3413 		   proto_method_implemented(proto->get_port),
3414 		   proto_method_implemented(proto->enter_memory_pressure));
3415 }
3416 
3417 static int proto_seq_show(struct seq_file *seq, void *v)
3418 {
3419 	if (v == &proto_list)
3420 		seq_printf(seq, "%-9s %-4s %-8s %-6s %-5s %-7s %-4s %-10s %s",
3421 			   "protocol",
3422 			   "size",
3423 			   "sockets",
3424 			   "memory",
3425 			   "press",
3426 			   "maxhdr",
3427 			   "slab",
3428 			   "module",
3429 			   "cl co di ac io in de sh ss gs se re sp bi br ha uh gp em\n");
3430 	else
3431 		proto_seq_printf(seq, list_entry(v, struct proto, node));
3432 	return 0;
3433 }
3434 
3435 static const struct seq_operations proto_seq_ops = {
3436 	.start  = proto_seq_start,
3437 	.next   = proto_seq_next,
3438 	.stop   = proto_seq_stop,
3439 	.show   = proto_seq_show,
3440 };
3441 
3442 static int proto_seq_open(struct inode *inode, struct file *file)
3443 {
3444 	return seq_open_net(inode, file, &proto_seq_ops,
3445 			    sizeof(struct seq_net_private));
3446 }
3447 
3448 static const struct file_operations proto_seq_fops = {
3449 	.open		= proto_seq_open,
3450 	.read		= seq_read,
3451 	.llseek		= seq_lseek,
3452 	.release	= seq_release_net,
3453 };
3454 
3455 static __net_init int proto_init_net(struct net *net)
3456 {
3457 	if (!proc_create("protocols", 0444, net->proc_net, &proto_seq_fops))
3458 		return -ENOMEM;
3459 
3460 	return 0;
3461 }
3462 
3463 static __net_exit void proto_exit_net(struct net *net)
3464 {
3465 	remove_proc_entry("protocols", net->proc_net);
3466 }
3467 
3468 
3469 static __net_initdata struct pernet_operations proto_net_ops = {
3470 	.init = proto_init_net,
3471 	.exit = proto_exit_net,
3472 };
3473 
3474 static int __init proto_init(void)
3475 {
3476 	return register_pernet_subsys(&proto_net_ops);
3477 }
3478 
3479 subsys_initcall(proto_init);
3480 
3481 #endif /* PROC_FS */
3482 
3483 #ifdef CONFIG_NET_RX_BUSY_POLL
3484 bool sk_busy_loop_end(void *p, unsigned long start_time)
3485 {
3486 	struct sock *sk = p;
3487 
3488 	return !skb_queue_empty(&sk->sk_receive_queue) ||
3489 	       sk_busy_loop_timeout(sk, start_time);
3490 }
3491 EXPORT_SYMBOL(sk_busy_loop_end);
3492 #endif /* CONFIG_NET_RX_BUSY_POLL */
3493