xref: /openbmc/linux/net/core/sock.c (revision 95e9fd10)
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/types.h>
97 #include <linux/socket.h>
98 #include <linux/in.h>
99 #include <linux/kernel.h>
100 #include <linux/module.h>
101 #include <linux/proc_fs.h>
102 #include <linux/seq_file.h>
103 #include <linux/sched.h>
104 #include <linux/timer.h>
105 #include <linux/string.h>
106 #include <linux/sockios.h>
107 #include <linux/net.h>
108 #include <linux/mm.h>
109 #include <linux/slab.h>
110 #include <linux/interrupt.h>
111 #include <linux/poll.h>
112 #include <linux/tcp.h>
113 #include <linux/init.h>
114 #include <linux/highmem.h>
115 #include <linux/user_namespace.h>
116 #include <linux/static_key.h>
117 #include <linux/memcontrol.h>
118 #include <linux/prefetch.h>
119 
120 #include <asm/uaccess.h>
121 
122 #include <linux/netdevice.h>
123 #include <net/protocol.h>
124 #include <linux/skbuff.h>
125 #include <net/net_namespace.h>
126 #include <net/request_sock.h>
127 #include <net/sock.h>
128 #include <linux/net_tstamp.h>
129 #include <net/xfrm.h>
130 #include <linux/ipsec.h>
131 #include <net/cls_cgroup.h>
132 #include <net/netprio_cgroup.h>
133 
134 #include <linux/filter.h>
135 
136 #include <trace/events/sock.h>
137 
138 #ifdef CONFIG_INET
139 #include <net/tcp.h>
140 #endif
141 
142 static DEFINE_MUTEX(proto_list_mutex);
143 static LIST_HEAD(proto_list);
144 
145 #ifdef CONFIG_MEMCG_KMEM
146 int mem_cgroup_sockets_init(struct mem_cgroup *memcg, struct cgroup_subsys *ss)
147 {
148 	struct proto *proto;
149 	int ret = 0;
150 
151 	mutex_lock(&proto_list_mutex);
152 	list_for_each_entry(proto, &proto_list, node) {
153 		if (proto->init_cgroup) {
154 			ret = proto->init_cgroup(memcg, ss);
155 			if (ret)
156 				goto out;
157 		}
158 	}
159 
160 	mutex_unlock(&proto_list_mutex);
161 	return ret;
162 out:
163 	list_for_each_entry_continue_reverse(proto, &proto_list, node)
164 		if (proto->destroy_cgroup)
165 			proto->destroy_cgroup(memcg);
166 	mutex_unlock(&proto_list_mutex);
167 	return ret;
168 }
169 
170 void mem_cgroup_sockets_destroy(struct mem_cgroup *memcg)
171 {
172 	struct proto *proto;
173 
174 	mutex_lock(&proto_list_mutex);
175 	list_for_each_entry_reverse(proto, &proto_list, node)
176 		if (proto->destroy_cgroup)
177 			proto->destroy_cgroup(memcg);
178 	mutex_unlock(&proto_list_mutex);
179 }
180 #endif
181 
182 /*
183  * Each address family might have different locking rules, so we have
184  * one slock key per address family:
185  */
186 static struct lock_class_key af_family_keys[AF_MAX];
187 static struct lock_class_key af_family_slock_keys[AF_MAX];
188 
189 struct static_key memcg_socket_limit_enabled;
190 EXPORT_SYMBOL(memcg_socket_limit_enabled);
191 
192 /*
193  * Make lock validator output more readable. (we pre-construct these
194  * strings build-time, so that runtime initialization of socket
195  * locks is fast):
196  */
197 static const char *const af_family_key_strings[AF_MAX+1] = {
198   "sk_lock-AF_UNSPEC", "sk_lock-AF_UNIX"     , "sk_lock-AF_INET"     ,
199   "sk_lock-AF_AX25"  , "sk_lock-AF_IPX"      , "sk_lock-AF_APPLETALK",
200   "sk_lock-AF_NETROM", "sk_lock-AF_BRIDGE"   , "sk_lock-AF_ATMPVC"   ,
201   "sk_lock-AF_X25"   , "sk_lock-AF_INET6"    , "sk_lock-AF_ROSE"     ,
202   "sk_lock-AF_DECnet", "sk_lock-AF_NETBEUI"  , "sk_lock-AF_SECURITY" ,
203   "sk_lock-AF_KEY"   , "sk_lock-AF_NETLINK"  , "sk_lock-AF_PACKET"   ,
204   "sk_lock-AF_ASH"   , "sk_lock-AF_ECONET"   , "sk_lock-AF_ATMSVC"   ,
205   "sk_lock-AF_RDS"   , "sk_lock-AF_SNA"      , "sk_lock-AF_IRDA"     ,
206   "sk_lock-AF_PPPOX" , "sk_lock-AF_WANPIPE"  , "sk_lock-AF_LLC"      ,
207   "sk_lock-27"       , "sk_lock-28"          , "sk_lock-AF_CAN"      ,
208   "sk_lock-AF_TIPC"  , "sk_lock-AF_BLUETOOTH", "sk_lock-IUCV"        ,
209   "sk_lock-AF_RXRPC" , "sk_lock-AF_ISDN"     , "sk_lock-AF_PHONET"   ,
210   "sk_lock-AF_IEEE802154", "sk_lock-AF_CAIF" , "sk_lock-AF_ALG"      ,
211   "sk_lock-AF_NFC"   , "sk_lock-AF_MAX"
212 };
213 static const char *const af_family_slock_key_strings[AF_MAX+1] = {
214   "slock-AF_UNSPEC", "slock-AF_UNIX"     , "slock-AF_INET"     ,
215   "slock-AF_AX25"  , "slock-AF_IPX"      , "slock-AF_APPLETALK",
216   "slock-AF_NETROM", "slock-AF_BRIDGE"   , "slock-AF_ATMPVC"   ,
217   "slock-AF_X25"   , "slock-AF_INET6"    , "slock-AF_ROSE"     ,
218   "slock-AF_DECnet", "slock-AF_NETBEUI"  , "slock-AF_SECURITY" ,
219   "slock-AF_KEY"   , "slock-AF_NETLINK"  , "slock-AF_PACKET"   ,
220   "slock-AF_ASH"   , "slock-AF_ECONET"   , "slock-AF_ATMSVC"   ,
221   "slock-AF_RDS"   , "slock-AF_SNA"      , "slock-AF_IRDA"     ,
222   "slock-AF_PPPOX" , "slock-AF_WANPIPE"  , "slock-AF_LLC"      ,
223   "slock-27"       , "slock-28"          , "slock-AF_CAN"      ,
224   "slock-AF_TIPC"  , "slock-AF_BLUETOOTH", "slock-AF_IUCV"     ,
225   "slock-AF_RXRPC" , "slock-AF_ISDN"     , "slock-AF_PHONET"   ,
226   "slock-AF_IEEE802154", "slock-AF_CAIF" , "slock-AF_ALG"      ,
227   "slock-AF_NFC"   , "slock-AF_MAX"
228 };
229 static const char *const af_family_clock_key_strings[AF_MAX+1] = {
230   "clock-AF_UNSPEC", "clock-AF_UNIX"     , "clock-AF_INET"     ,
231   "clock-AF_AX25"  , "clock-AF_IPX"      , "clock-AF_APPLETALK",
232   "clock-AF_NETROM", "clock-AF_BRIDGE"   , "clock-AF_ATMPVC"   ,
233   "clock-AF_X25"   , "clock-AF_INET6"    , "clock-AF_ROSE"     ,
234   "clock-AF_DECnet", "clock-AF_NETBEUI"  , "clock-AF_SECURITY" ,
235   "clock-AF_KEY"   , "clock-AF_NETLINK"  , "clock-AF_PACKET"   ,
236   "clock-AF_ASH"   , "clock-AF_ECONET"   , "clock-AF_ATMSVC"   ,
237   "clock-AF_RDS"   , "clock-AF_SNA"      , "clock-AF_IRDA"     ,
238   "clock-AF_PPPOX" , "clock-AF_WANPIPE"  , "clock-AF_LLC"      ,
239   "clock-27"       , "clock-28"          , "clock-AF_CAN"      ,
240   "clock-AF_TIPC"  , "clock-AF_BLUETOOTH", "clock-AF_IUCV"     ,
241   "clock-AF_RXRPC" , "clock-AF_ISDN"     , "clock-AF_PHONET"   ,
242   "clock-AF_IEEE802154", "clock-AF_CAIF" , "clock-AF_ALG"      ,
243   "clock-AF_NFC"   , "clock-AF_MAX"
244 };
245 
246 /*
247  * sk_callback_lock locking rules are per-address-family,
248  * so split the lock classes by using a per-AF key:
249  */
250 static struct lock_class_key af_callback_keys[AF_MAX];
251 
252 /* Take into consideration the size of the struct sk_buff overhead in the
253  * determination of these values, since that is non-constant across
254  * platforms.  This makes socket queueing behavior and performance
255  * not depend upon such differences.
256  */
257 #define _SK_MEM_PACKETS		256
258 #define _SK_MEM_OVERHEAD	SKB_TRUESIZE(256)
259 #define SK_WMEM_MAX		(_SK_MEM_OVERHEAD * _SK_MEM_PACKETS)
260 #define SK_RMEM_MAX		(_SK_MEM_OVERHEAD * _SK_MEM_PACKETS)
261 
262 /* Run time adjustable parameters. */
263 __u32 sysctl_wmem_max __read_mostly = SK_WMEM_MAX;
264 EXPORT_SYMBOL(sysctl_wmem_max);
265 __u32 sysctl_rmem_max __read_mostly = SK_RMEM_MAX;
266 EXPORT_SYMBOL(sysctl_rmem_max);
267 __u32 sysctl_wmem_default __read_mostly = SK_WMEM_MAX;
268 __u32 sysctl_rmem_default __read_mostly = SK_RMEM_MAX;
269 
270 /* Maximal space eaten by iovec or ancillary data plus some space */
271 int sysctl_optmem_max __read_mostly = sizeof(unsigned long)*(2*UIO_MAXIOV+512);
272 EXPORT_SYMBOL(sysctl_optmem_max);
273 
274 struct static_key memalloc_socks = STATIC_KEY_INIT_FALSE;
275 EXPORT_SYMBOL_GPL(memalloc_socks);
276 
277 /**
278  * sk_set_memalloc - sets %SOCK_MEMALLOC
279  * @sk: socket to set it on
280  *
281  * Set %SOCK_MEMALLOC on a socket for access to emergency reserves.
282  * It's the responsibility of the admin to adjust min_free_kbytes
283  * to meet the requirements
284  */
285 void sk_set_memalloc(struct sock *sk)
286 {
287 	sock_set_flag(sk, SOCK_MEMALLOC);
288 	sk->sk_allocation |= __GFP_MEMALLOC;
289 	static_key_slow_inc(&memalloc_socks);
290 }
291 EXPORT_SYMBOL_GPL(sk_set_memalloc);
292 
293 void sk_clear_memalloc(struct sock *sk)
294 {
295 	sock_reset_flag(sk, SOCK_MEMALLOC);
296 	sk->sk_allocation &= ~__GFP_MEMALLOC;
297 	static_key_slow_dec(&memalloc_socks);
298 
299 	/*
300 	 * SOCK_MEMALLOC is allowed to ignore rmem limits to ensure forward
301 	 * progress of swapping. However, if SOCK_MEMALLOC is cleared while
302 	 * it has rmem allocations there is a risk that the user of the
303 	 * socket cannot make forward progress due to exceeding the rmem
304 	 * limits. By rights, sk_clear_memalloc() should only be called
305 	 * on sockets being torn down but warn and reset the accounting if
306 	 * that assumption breaks.
307 	 */
308 	if (WARN_ON(sk->sk_forward_alloc))
309 		sk_mem_reclaim(sk);
310 }
311 EXPORT_SYMBOL_GPL(sk_clear_memalloc);
312 
313 int __sk_backlog_rcv(struct sock *sk, struct sk_buff *skb)
314 {
315 	int ret;
316 	unsigned long pflags = current->flags;
317 
318 	/* these should have been dropped before queueing */
319 	BUG_ON(!sock_flag(sk, SOCK_MEMALLOC));
320 
321 	current->flags |= PF_MEMALLOC;
322 	ret = sk->sk_backlog_rcv(sk, skb);
323 	tsk_restore_flags(current, pflags, PF_MEMALLOC);
324 
325 	return ret;
326 }
327 EXPORT_SYMBOL(__sk_backlog_rcv);
328 
329 #if defined(CONFIG_CGROUPS)
330 #if !defined(CONFIG_NET_CLS_CGROUP)
331 int net_cls_subsys_id = -1;
332 EXPORT_SYMBOL_GPL(net_cls_subsys_id);
333 #endif
334 #if !defined(CONFIG_NETPRIO_CGROUP)
335 int net_prio_subsys_id = -1;
336 EXPORT_SYMBOL_GPL(net_prio_subsys_id);
337 #endif
338 #endif
339 
340 static int sock_set_timeout(long *timeo_p, char __user *optval, int optlen)
341 {
342 	struct timeval tv;
343 
344 	if (optlen < sizeof(tv))
345 		return -EINVAL;
346 	if (copy_from_user(&tv, optval, sizeof(tv)))
347 		return -EFAULT;
348 	if (tv.tv_usec < 0 || tv.tv_usec >= USEC_PER_SEC)
349 		return -EDOM;
350 
351 	if (tv.tv_sec < 0) {
352 		static int warned __read_mostly;
353 
354 		*timeo_p = 0;
355 		if (warned < 10 && net_ratelimit()) {
356 			warned++;
357 			pr_info("%s: `%s' (pid %d) tries to set negative timeout\n",
358 				__func__, current->comm, task_pid_nr(current));
359 		}
360 		return 0;
361 	}
362 	*timeo_p = MAX_SCHEDULE_TIMEOUT;
363 	if (tv.tv_sec == 0 && tv.tv_usec == 0)
364 		return 0;
365 	if (tv.tv_sec < (MAX_SCHEDULE_TIMEOUT/HZ - 1))
366 		*timeo_p = tv.tv_sec*HZ + (tv.tv_usec+(1000000/HZ-1))/(1000000/HZ);
367 	return 0;
368 }
369 
370 static void sock_warn_obsolete_bsdism(const char *name)
371 {
372 	static int warned;
373 	static char warncomm[TASK_COMM_LEN];
374 	if (strcmp(warncomm, current->comm) && warned < 5) {
375 		strcpy(warncomm,  current->comm);
376 		pr_warn("process `%s' is using obsolete %s SO_BSDCOMPAT\n",
377 			warncomm, name);
378 		warned++;
379 	}
380 }
381 
382 #define SK_FLAGS_TIMESTAMP ((1UL << SOCK_TIMESTAMP) | (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE))
383 
384 static void sock_disable_timestamp(struct sock *sk, unsigned long flags)
385 {
386 	if (sk->sk_flags & flags) {
387 		sk->sk_flags &= ~flags;
388 		if (!(sk->sk_flags & SK_FLAGS_TIMESTAMP))
389 			net_disable_timestamp();
390 	}
391 }
392 
393 
394 int sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
395 {
396 	int err;
397 	int skb_len;
398 	unsigned long flags;
399 	struct sk_buff_head *list = &sk->sk_receive_queue;
400 
401 	if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf) {
402 		atomic_inc(&sk->sk_drops);
403 		trace_sock_rcvqueue_full(sk, skb);
404 		return -ENOMEM;
405 	}
406 
407 	err = sk_filter(sk, skb);
408 	if (err)
409 		return err;
410 
411 	if (!sk_rmem_schedule(sk, skb, skb->truesize)) {
412 		atomic_inc(&sk->sk_drops);
413 		return -ENOBUFS;
414 	}
415 
416 	skb->dev = NULL;
417 	skb_set_owner_r(skb, sk);
418 
419 	/* Cache the SKB length before we tack it onto the receive
420 	 * queue.  Once it is added it no longer belongs to us and
421 	 * may be freed by other threads of control pulling packets
422 	 * from the queue.
423 	 */
424 	skb_len = skb->len;
425 
426 	/* we escape from rcu protected region, make sure we dont leak
427 	 * a norefcounted dst
428 	 */
429 	skb_dst_force(skb);
430 
431 	spin_lock_irqsave(&list->lock, flags);
432 	skb->dropcount = atomic_read(&sk->sk_drops);
433 	__skb_queue_tail(list, skb);
434 	spin_unlock_irqrestore(&list->lock, flags);
435 
436 	if (!sock_flag(sk, SOCK_DEAD))
437 		sk->sk_data_ready(sk, skb_len);
438 	return 0;
439 }
440 EXPORT_SYMBOL(sock_queue_rcv_skb);
441 
442 int sk_receive_skb(struct sock *sk, struct sk_buff *skb, const int nested)
443 {
444 	int rc = NET_RX_SUCCESS;
445 
446 	if (sk_filter(sk, skb))
447 		goto discard_and_relse;
448 
449 	skb->dev = NULL;
450 
451 	if (sk_rcvqueues_full(sk, skb, sk->sk_rcvbuf)) {
452 		atomic_inc(&sk->sk_drops);
453 		goto discard_and_relse;
454 	}
455 	if (nested)
456 		bh_lock_sock_nested(sk);
457 	else
458 		bh_lock_sock(sk);
459 	if (!sock_owned_by_user(sk)) {
460 		/*
461 		 * trylock + unlock semantics:
462 		 */
463 		mutex_acquire(&sk->sk_lock.dep_map, 0, 1, _RET_IP_);
464 
465 		rc = sk_backlog_rcv(sk, skb);
466 
467 		mutex_release(&sk->sk_lock.dep_map, 1, _RET_IP_);
468 	} else if (sk_add_backlog(sk, skb, sk->sk_rcvbuf)) {
469 		bh_unlock_sock(sk);
470 		atomic_inc(&sk->sk_drops);
471 		goto discard_and_relse;
472 	}
473 
474 	bh_unlock_sock(sk);
475 out:
476 	sock_put(sk);
477 	return rc;
478 discard_and_relse:
479 	kfree_skb(skb);
480 	goto out;
481 }
482 EXPORT_SYMBOL(sk_receive_skb);
483 
484 void sk_reset_txq(struct sock *sk)
485 {
486 	sk_tx_queue_clear(sk);
487 }
488 EXPORT_SYMBOL(sk_reset_txq);
489 
490 struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie)
491 {
492 	struct dst_entry *dst = __sk_dst_get(sk);
493 
494 	if (dst && dst->obsolete && dst->ops->check(dst, cookie) == NULL) {
495 		sk_tx_queue_clear(sk);
496 		RCU_INIT_POINTER(sk->sk_dst_cache, NULL);
497 		dst_release(dst);
498 		return NULL;
499 	}
500 
501 	return dst;
502 }
503 EXPORT_SYMBOL(__sk_dst_check);
504 
505 struct dst_entry *sk_dst_check(struct sock *sk, u32 cookie)
506 {
507 	struct dst_entry *dst = sk_dst_get(sk);
508 
509 	if (dst && dst->obsolete && dst->ops->check(dst, cookie) == NULL) {
510 		sk_dst_reset(sk);
511 		dst_release(dst);
512 		return NULL;
513 	}
514 
515 	return dst;
516 }
517 EXPORT_SYMBOL(sk_dst_check);
518 
519 static int sock_bindtodevice(struct sock *sk, char __user *optval, int optlen)
520 {
521 	int ret = -ENOPROTOOPT;
522 #ifdef CONFIG_NETDEVICES
523 	struct net *net = sock_net(sk);
524 	char devname[IFNAMSIZ];
525 	int index;
526 
527 	/* Sorry... */
528 	ret = -EPERM;
529 	if (!capable(CAP_NET_RAW))
530 		goto out;
531 
532 	ret = -EINVAL;
533 	if (optlen < 0)
534 		goto out;
535 
536 	/* Bind this socket to a particular device like "eth0",
537 	 * as specified in the passed interface name. If the
538 	 * name is "" or the option length is zero the socket
539 	 * is not bound.
540 	 */
541 	if (optlen > IFNAMSIZ - 1)
542 		optlen = IFNAMSIZ - 1;
543 	memset(devname, 0, sizeof(devname));
544 
545 	ret = -EFAULT;
546 	if (copy_from_user(devname, optval, optlen))
547 		goto out;
548 
549 	index = 0;
550 	if (devname[0] != '\0') {
551 		struct net_device *dev;
552 
553 		rcu_read_lock();
554 		dev = dev_get_by_name_rcu(net, devname);
555 		if (dev)
556 			index = dev->ifindex;
557 		rcu_read_unlock();
558 		ret = -ENODEV;
559 		if (!dev)
560 			goto out;
561 	}
562 
563 	lock_sock(sk);
564 	sk->sk_bound_dev_if = index;
565 	sk_dst_reset(sk);
566 	release_sock(sk);
567 
568 	ret = 0;
569 
570 out:
571 #endif
572 
573 	return ret;
574 }
575 
576 static inline void sock_valbool_flag(struct sock *sk, int bit, int valbool)
577 {
578 	if (valbool)
579 		sock_set_flag(sk, bit);
580 	else
581 		sock_reset_flag(sk, bit);
582 }
583 
584 /*
585  *	This is meant for all protocols to use and covers goings on
586  *	at the socket level. Everything here is generic.
587  */
588 
589 int sock_setsockopt(struct socket *sock, int level, int optname,
590 		    char __user *optval, unsigned int optlen)
591 {
592 	struct sock *sk = sock->sk;
593 	int val;
594 	int valbool;
595 	struct linger ling;
596 	int ret = 0;
597 
598 	/*
599 	 *	Options without arguments
600 	 */
601 
602 	if (optname == SO_BINDTODEVICE)
603 		return sock_bindtodevice(sk, optval, optlen);
604 
605 	if (optlen < sizeof(int))
606 		return -EINVAL;
607 
608 	if (get_user(val, (int __user *)optval))
609 		return -EFAULT;
610 
611 	valbool = val ? 1 : 0;
612 
613 	lock_sock(sk);
614 
615 	switch (optname) {
616 	case SO_DEBUG:
617 		if (val && !capable(CAP_NET_ADMIN))
618 			ret = -EACCES;
619 		else
620 			sock_valbool_flag(sk, SOCK_DBG, valbool);
621 		break;
622 	case SO_REUSEADDR:
623 		sk->sk_reuse = (valbool ? SK_CAN_REUSE : SK_NO_REUSE);
624 		break;
625 	case SO_TYPE:
626 	case SO_PROTOCOL:
627 	case SO_DOMAIN:
628 	case SO_ERROR:
629 		ret = -ENOPROTOOPT;
630 		break;
631 	case SO_DONTROUTE:
632 		sock_valbool_flag(sk, SOCK_LOCALROUTE, valbool);
633 		break;
634 	case SO_BROADCAST:
635 		sock_valbool_flag(sk, SOCK_BROADCAST, valbool);
636 		break;
637 	case SO_SNDBUF:
638 		/* Don't error on this BSD doesn't and if you think
639 		 * about it this is right. Otherwise apps have to
640 		 * play 'guess the biggest size' games. RCVBUF/SNDBUF
641 		 * are treated in BSD as hints
642 		 */
643 		val = min_t(u32, val, sysctl_wmem_max);
644 set_sndbuf:
645 		sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
646 		sk->sk_sndbuf = max_t(u32, val * 2, SOCK_MIN_SNDBUF);
647 		/* Wake up sending tasks if we upped the value. */
648 		sk->sk_write_space(sk);
649 		break;
650 
651 	case SO_SNDBUFFORCE:
652 		if (!capable(CAP_NET_ADMIN)) {
653 			ret = -EPERM;
654 			break;
655 		}
656 		goto set_sndbuf;
657 
658 	case SO_RCVBUF:
659 		/* Don't error on this BSD doesn't and if you think
660 		 * about it this is right. Otherwise apps have to
661 		 * play 'guess the biggest size' games. RCVBUF/SNDBUF
662 		 * are treated in BSD as hints
663 		 */
664 		val = min_t(u32, val, sysctl_rmem_max);
665 set_rcvbuf:
666 		sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
667 		/*
668 		 * We double it on the way in to account for
669 		 * "struct sk_buff" etc. overhead.   Applications
670 		 * assume that the SO_RCVBUF setting they make will
671 		 * allow that much actual data to be received on that
672 		 * socket.
673 		 *
674 		 * Applications are unaware that "struct sk_buff" and
675 		 * other overheads allocate from the receive buffer
676 		 * during socket buffer allocation.
677 		 *
678 		 * And after considering the possible alternatives,
679 		 * returning the value we actually used in getsockopt
680 		 * is the most desirable behavior.
681 		 */
682 		sk->sk_rcvbuf = max_t(u32, val * 2, SOCK_MIN_RCVBUF);
683 		break;
684 
685 	case SO_RCVBUFFORCE:
686 		if (!capable(CAP_NET_ADMIN)) {
687 			ret = -EPERM;
688 			break;
689 		}
690 		goto set_rcvbuf;
691 
692 	case SO_KEEPALIVE:
693 #ifdef CONFIG_INET
694 		if (sk->sk_protocol == IPPROTO_TCP)
695 			tcp_set_keepalive(sk, valbool);
696 #endif
697 		sock_valbool_flag(sk, SOCK_KEEPOPEN, valbool);
698 		break;
699 
700 	case SO_OOBINLINE:
701 		sock_valbool_flag(sk, SOCK_URGINLINE, valbool);
702 		break;
703 
704 	case SO_NO_CHECK:
705 		sk->sk_no_check = valbool;
706 		break;
707 
708 	case SO_PRIORITY:
709 		if ((val >= 0 && val <= 6) || capable(CAP_NET_ADMIN))
710 			sk->sk_priority = val;
711 		else
712 			ret = -EPERM;
713 		break;
714 
715 	case SO_LINGER:
716 		if (optlen < sizeof(ling)) {
717 			ret = -EINVAL;	/* 1003.1g */
718 			break;
719 		}
720 		if (copy_from_user(&ling, optval, sizeof(ling))) {
721 			ret = -EFAULT;
722 			break;
723 		}
724 		if (!ling.l_onoff)
725 			sock_reset_flag(sk, SOCK_LINGER);
726 		else {
727 #if (BITS_PER_LONG == 32)
728 			if ((unsigned int)ling.l_linger >= MAX_SCHEDULE_TIMEOUT/HZ)
729 				sk->sk_lingertime = MAX_SCHEDULE_TIMEOUT;
730 			else
731 #endif
732 				sk->sk_lingertime = (unsigned int)ling.l_linger * HZ;
733 			sock_set_flag(sk, SOCK_LINGER);
734 		}
735 		break;
736 
737 	case SO_BSDCOMPAT:
738 		sock_warn_obsolete_bsdism("setsockopt");
739 		break;
740 
741 	case SO_PASSCRED:
742 		if (valbool)
743 			set_bit(SOCK_PASSCRED, &sock->flags);
744 		else
745 			clear_bit(SOCK_PASSCRED, &sock->flags);
746 		break;
747 
748 	case SO_TIMESTAMP:
749 	case SO_TIMESTAMPNS:
750 		if (valbool)  {
751 			if (optname == SO_TIMESTAMP)
752 				sock_reset_flag(sk, SOCK_RCVTSTAMPNS);
753 			else
754 				sock_set_flag(sk, SOCK_RCVTSTAMPNS);
755 			sock_set_flag(sk, SOCK_RCVTSTAMP);
756 			sock_enable_timestamp(sk, SOCK_TIMESTAMP);
757 		} else {
758 			sock_reset_flag(sk, SOCK_RCVTSTAMP);
759 			sock_reset_flag(sk, SOCK_RCVTSTAMPNS);
760 		}
761 		break;
762 
763 	case SO_TIMESTAMPING:
764 		if (val & ~SOF_TIMESTAMPING_MASK) {
765 			ret = -EINVAL;
766 			break;
767 		}
768 		sock_valbool_flag(sk, SOCK_TIMESTAMPING_TX_HARDWARE,
769 				  val & SOF_TIMESTAMPING_TX_HARDWARE);
770 		sock_valbool_flag(sk, SOCK_TIMESTAMPING_TX_SOFTWARE,
771 				  val & SOF_TIMESTAMPING_TX_SOFTWARE);
772 		sock_valbool_flag(sk, SOCK_TIMESTAMPING_RX_HARDWARE,
773 				  val & SOF_TIMESTAMPING_RX_HARDWARE);
774 		if (val & SOF_TIMESTAMPING_RX_SOFTWARE)
775 			sock_enable_timestamp(sk,
776 					      SOCK_TIMESTAMPING_RX_SOFTWARE);
777 		else
778 			sock_disable_timestamp(sk,
779 					       (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE));
780 		sock_valbool_flag(sk, SOCK_TIMESTAMPING_SOFTWARE,
781 				  val & SOF_TIMESTAMPING_SOFTWARE);
782 		sock_valbool_flag(sk, SOCK_TIMESTAMPING_SYS_HARDWARE,
783 				  val & SOF_TIMESTAMPING_SYS_HARDWARE);
784 		sock_valbool_flag(sk, SOCK_TIMESTAMPING_RAW_HARDWARE,
785 				  val & SOF_TIMESTAMPING_RAW_HARDWARE);
786 		break;
787 
788 	case SO_RCVLOWAT:
789 		if (val < 0)
790 			val = INT_MAX;
791 		sk->sk_rcvlowat = val ? : 1;
792 		break;
793 
794 	case SO_RCVTIMEO:
795 		ret = sock_set_timeout(&sk->sk_rcvtimeo, optval, optlen);
796 		break;
797 
798 	case SO_SNDTIMEO:
799 		ret = sock_set_timeout(&sk->sk_sndtimeo, optval, optlen);
800 		break;
801 
802 	case SO_ATTACH_FILTER:
803 		ret = -EINVAL;
804 		if (optlen == sizeof(struct sock_fprog)) {
805 			struct sock_fprog fprog;
806 
807 			ret = -EFAULT;
808 			if (copy_from_user(&fprog, optval, sizeof(fprog)))
809 				break;
810 
811 			ret = sk_attach_filter(&fprog, sk);
812 		}
813 		break;
814 
815 	case SO_DETACH_FILTER:
816 		ret = sk_detach_filter(sk);
817 		break;
818 
819 	case SO_PASSSEC:
820 		if (valbool)
821 			set_bit(SOCK_PASSSEC, &sock->flags);
822 		else
823 			clear_bit(SOCK_PASSSEC, &sock->flags);
824 		break;
825 	case SO_MARK:
826 		if (!capable(CAP_NET_ADMIN))
827 			ret = -EPERM;
828 		else
829 			sk->sk_mark = val;
830 		break;
831 
832 		/* We implement the SO_SNDLOWAT etc to
833 		   not be settable (1003.1g 5.3) */
834 	case SO_RXQ_OVFL:
835 		sock_valbool_flag(sk, SOCK_RXQ_OVFL, valbool);
836 		break;
837 
838 	case SO_WIFI_STATUS:
839 		sock_valbool_flag(sk, SOCK_WIFI_STATUS, valbool);
840 		break;
841 
842 	case SO_PEEK_OFF:
843 		if (sock->ops->set_peek_off)
844 			sock->ops->set_peek_off(sk, val);
845 		else
846 			ret = -EOPNOTSUPP;
847 		break;
848 
849 	case SO_NOFCS:
850 		sock_valbool_flag(sk, SOCK_NOFCS, valbool);
851 		break;
852 
853 	default:
854 		ret = -ENOPROTOOPT;
855 		break;
856 	}
857 	release_sock(sk);
858 	return ret;
859 }
860 EXPORT_SYMBOL(sock_setsockopt);
861 
862 
863 void cred_to_ucred(struct pid *pid, const struct cred *cred,
864 		   struct ucred *ucred)
865 {
866 	ucred->pid = pid_vnr(pid);
867 	ucred->uid = ucred->gid = -1;
868 	if (cred) {
869 		struct user_namespace *current_ns = current_user_ns();
870 
871 		ucred->uid = from_kuid(current_ns, cred->euid);
872 		ucred->gid = from_kgid(current_ns, cred->egid);
873 	}
874 }
875 EXPORT_SYMBOL_GPL(cred_to_ucred);
876 
877 int sock_getsockopt(struct socket *sock, int level, int optname,
878 		    char __user *optval, int __user *optlen)
879 {
880 	struct sock *sk = sock->sk;
881 
882 	union {
883 		int val;
884 		struct linger ling;
885 		struct timeval tm;
886 	} v;
887 
888 	int lv = sizeof(int);
889 	int len;
890 
891 	if (get_user(len, optlen))
892 		return -EFAULT;
893 	if (len < 0)
894 		return -EINVAL;
895 
896 	memset(&v, 0, sizeof(v));
897 
898 	switch (optname) {
899 	case SO_DEBUG:
900 		v.val = sock_flag(sk, SOCK_DBG);
901 		break;
902 
903 	case SO_DONTROUTE:
904 		v.val = sock_flag(sk, SOCK_LOCALROUTE);
905 		break;
906 
907 	case SO_BROADCAST:
908 		v.val = sock_flag(sk, SOCK_BROADCAST);
909 		break;
910 
911 	case SO_SNDBUF:
912 		v.val = sk->sk_sndbuf;
913 		break;
914 
915 	case SO_RCVBUF:
916 		v.val = sk->sk_rcvbuf;
917 		break;
918 
919 	case SO_REUSEADDR:
920 		v.val = sk->sk_reuse;
921 		break;
922 
923 	case SO_KEEPALIVE:
924 		v.val = sock_flag(sk, SOCK_KEEPOPEN);
925 		break;
926 
927 	case SO_TYPE:
928 		v.val = sk->sk_type;
929 		break;
930 
931 	case SO_PROTOCOL:
932 		v.val = sk->sk_protocol;
933 		break;
934 
935 	case SO_DOMAIN:
936 		v.val = sk->sk_family;
937 		break;
938 
939 	case SO_ERROR:
940 		v.val = -sock_error(sk);
941 		if (v.val == 0)
942 			v.val = xchg(&sk->sk_err_soft, 0);
943 		break;
944 
945 	case SO_OOBINLINE:
946 		v.val = sock_flag(sk, SOCK_URGINLINE);
947 		break;
948 
949 	case SO_NO_CHECK:
950 		v.val = sk->sk_no_check;
951 		break;
952 
953 	case SO_PRIORITY:
954 		v.val = sk->sk_priority;
955 		break;
956 
957 	case SO_LINGER:
958 		lv		= sizeof(v.ling);
959 		v.ling.l_onoff	= sock_flag(sk, SOCK_LINGER);
960 		v.ling.l_linger	= sk->sk_lingertime / HZ;
961 		break;
962 
963 	case SO_BSDCOMPAT:
964 		sock_warn_obsolete_bsdism("getsockopt");
965 		break;
966 
967 	case SO_TIMESTAMP:
968 		v.val = sock_flag(sk, SOCK_RCVTSTAMP) &&
969 				!sock_flag(sk, SOCK_RCVTSTAMPNS);
970 		break;
971 
972 	case SO_TIMESTAMPNS:
973 		v.val = sock_flag(sk, SOCK_RCVTSTAMPNS);
974 		break;
975 
976 	case SO_TIMESTAMPING:
977 		v.val = 0;
978 		if (sock_flag(sk, SOCK_TIMESTAMPING_TX_HARDWARE))
979 			v.val |= SOF_TIMESTAMPING_TX_HARDWARE;
980 		if (sock_flag(sk, SOCK_TIMESTAMPING_TX_SOFTWARE))
981 			v.val |= SOF_TIMESTAMPING_TX_SOFTWARE;
982 		if (sock_flag(sk, SOCK_TIMESTAMPING_RX_HARDWARE))
983 			v.val |= SOF_TIMESTAMPING_RX_HARDWARE;
984 		if (sock_flag(sk, SOCK_TIMESTAMPING_RX_SOFTWARE))
985 			v.val |= SOF_TIMESTAMPING_RX_SOFTWARE;
986 		if (sock_flag(sk, SOCK_TIMESTAMPING_SOFTWARE))
987 			v.val |= SOF_TIMESTAMPING_SOFTWARE;
988 		if (sock_flag(sk, SOCK_TIMESTAMPING_SYS_HARDWARE))
989 			v.val |= SOF_TIMESTAMPING_SYS_HARDWARE;
990 		if (sock_flag(sk, SOCK_TIMESTAMPING_RAW_HARDWARE))
991 			v.val |= SOF_TIMESTAMPING_RAW_HARDWARE;
992 		break;
993 
994 	case SO_RCVTIMEO:
995 		lv = sizeof(struct timeval);
996 		if (sk->sk_rcvtimeo == MAX_SCHEDULE_TIMEOUT) {
997 			v.tm.tv_sec = 0;
998 			v.tm.tv_usec = 0;
999 		} else {
1000 			v.tm.tv_sec = sk->sk_rcvtimeo / HZ;
1001 			v.tm.tv_usec = ((sk->sk_rcvtimeo % HZ) * 1000000) / HZ;
1002 		}
1003 		break;
1004 
1005 	case SO_SNDTIMEO:
1006 		lv = sizeof(struct timeval);
1007 		if (sk->sk_sndtimeo == MAX_SCHEDULE_TIMEOUT) {
1008 			v.tm.tv_sec = 0;
1009 			v.tm.tv_usec = 0;
1010 		} else {
1011 			v.tm.tv_sec = sk->sk_sndtimeo / HZ;
1012 			v.tm.tv_usec = ((sk->sk_sndtimeo % HZ) * 1000000) / HZ;
1013 		}
1014 		break;
1015 
1016 	case SO_RCVLOWAT:
1017 		v.val = sk->sk_rcvlowat;
1018 		break;
1019 
1020 	case SO_SNDLOWAT:
1021 		v.val = 1;
1022 		break;
1023 
1024 	case SO_PASSCRED:
1025 		v.val = !!test_bit(SOCK_PASSCRED, &sock->flags);
1026 		break;
1027 
1028 	case SO_PEERCRED:
1029 	{
1030 		struct ucred peercred;
1031 		if (len > sizeof(peercred))
1032 			len = sizeof(peercred);
1033 		cred_to_ucred(sk->sk_peer_pid, sk->sk_peer_cred, &peercred);
1034 		if (copy_to_user(optval, &peercred, len))
1035 			return -EFAULT;
1036 		goto lenout;
1037 	}
1038 
1039 	case SO_PEERNAME:
1040 	{
1041 		char address[128];
1042 
1043 		if (sock->ops->getname(sock, (struct sockaddr *)address, &lv, 2))
1044 			return -ENOTCONN;
1045 		if (lv < len)
1046 			return -EINVAL;
1047 		if (copy_to_user(optval, address, len))
1048 			return -EFAULT;
1049 		goto lenout;
1050 	}
1051 
1052 	/* Dubious BSD thing... Probably nobody even uses it, but
1053 	 * the UNIX standard wants it for whatever reason... -DaveM
1054 	 */
1055 	case SO_ACCEPTCONN:
1056 		v.val = sk->sk_state == TCP_LISTEN;
1057 		break;
1058 
1059 	case SO_PASSSEC:
1060 		v.val = !!test_bit(SOCK_PASSSEC, &sock->flags);
1061 		break;
1062 
1063 	case SO_PEERSEC:
1064 		return security_socket_getpeersec_stream(sock, optval, optlen, len);
1065 
1066 	case SO_MARK:
1067 		v.val = sk->sk_mark;
1068 		break;
1069 
1070 	case SO_RXQ_OVFL:
1071 		v.val = sock_flag(sk, SOCK_RXQ_OVFL);
1072 		break;
1073 
1074 	case SO_WIFI_STATUS:
1075 		v.val = sock_flag(sk, SOCK_WIFI_STATUS);
1076 		break;
1077 
1078 	case SO_PEEK_OFF:
1079 		if (!sock->ops->set_peek_off)
1080 			return -EOPNOTSUPP;
1081 
1082 		v.val = sk->sk_peek_off;
1083 		break;
1084 	case SO_NOFCS:
1085 		v.val = sock_flag(sk, SOCK_NOFCS);
1086 		break;
1087 	default:
1088 		return -ENOPROTOOPT;
1089 	}
1090 
1091 	if (len > lv)
1092 		len = lv;
1093 	if (copy_to_user(optval, &v, len))
1094 		return -EFAULT;
1095 lenout:
1096 	if (put_user(len, optlen))
1097 		return -EFAULT;
1098 	return 0;
1099 }
1100 
1101 /*
1102  * Initialize an sk_lock.
1103  *
1104  * (We also register the sk_lock with the lock validator.)
1105  */
1106 static inline void sock_lock_init(struct sock *sk)
1107 {
1108 	sock_lock_init_class_and_name(sk,
1109 			af_family_slock_key_strings[sk->sk_family],
1110 			af_family_slock_keys + sk->sk_family,
1111 			af_family_key_strings[sk->sk_family],
1112 			af_family_keys + sk->sk_family);
1113 }
1114 
1115 /*
1116  * Copy all fields from osk to nsk but nsk->sk_refcnt must not change yet,
1117  * even temporarly, because of RCU lookups. sk_node should also be left as is.
1118  * We must not copy fields between sk_dontcopy_begin and sk_dontcopy_end
1119  */
1120 static void sock_copy(struct sock *nsk, const struct sock *osk)
1121 {
1122 #ifdef CONFIG_SECURITY_NETWORK
1123 	void *sptr = nsk->sk_security;
1124 #endif
1125 	memcpy(nsk, osk, offsetof(struct sock, sk_dontcopy_begin));
1126 
1127 	memcpy(&nsk->sk_dontcopy_end, &osk->sk_dontcopy_end,
1128 	       osk->sk_prot->obj_size - offsetof(struct sock, sk_dontcopy_end));
1129 
1130 #ifdef CONFIG_SECURITY_NETWORK
1131 	nsk->sk_security = sptr;
1132 	security_sk_clone(osk, nsk);
1133 #endif
1134 }
1135 
1136 /*
1137  * caches using SLAB_DESTROY_BY_RCU should let .next pointer from nulls nodes
1138  * un-modified. Special care is taken when initializing object to zero.
1139  */
1140 static inline void sk_prot_clear_nulls(struct sock *sk, int size)
1141 {
1142 	if (offsetof(struct sock, sk_node.next) != 0)
1143 		memset(sk, 0, offsetof(struct sock, sk_node.next));
1144 	memset(&sk->sk_node.pprev, 0,
1145 	       size - offsetof(struct sock, sk_node.pprev));
1146 }
1147 
1148 void sk_prot_clear_portaddr_nulls(struct sock *sk, int size)
1149 {
1150 	unsigned long nulls1, nulls2;
1151 
1152 	nulls1 = offsetof(struct sock, __sk_common.skc_node.next);
1153 	nulls2 = offsetof(struct sock, __sk_common.skc_portaddr_node.next);
1154 	if (nulls1 > nulls2)
1155 		swap(nulls1, nulls2);
1156 
1157 	if (nulls1 != 0)
1158 		memset((char *)sk, 0, nulls1);
1159 	memset((char *)sk + nulls1 + sizeof(void *), 0,
1160 	       nulls2 - nulls1 - sizeof(void *));
1161 	memset((char *)sk + nulls2 + sizeof(void *), 0,
1162 	       size - nulls2 - sizeof(void *));
1163 }
1164 EXPORT_SYMBOL(sk_prot_clear_portaddr_nulls);
1165 
1166 static struct sock *sk_prot_alloc(struct proto *prot, gfp_t priority,
1167 		int family)
1168 {
1169 	struct sock *sk;
1170 	struct kmem_cache *slab;
1171 
1172 	slab = prot->slab;
1173 	if (slab != NULL) {
1174 		sk = kmem_cache_alloc(slab, priority & ~__GFP_ZERO);
1175 		if (!sk)
1176 			return sk;
1177 		if (priority & __GFP_ZERO) {
1178 			if (prot->clear_sk)
1179 				prot->clear_sk(sk, prot->obj_size);
1180 			else
1181 				sk_prot_clear_nulls(sk, prot->obj_size);
1182 		}
1183 	} else
1184 		sk = kmalloc(prot->obj_size, priority);
1185 
1186 	if (sk != NULL) {
1187 		kmemcheck_annotate_bitfield(sk, flags);
1188 
1189 		if (security_sk_alloc(sk, family, priority))
1190 			goto out_free;
1191 
1192 		if (!try_module_get(prot->owner))
1193 			goto out_free_sec;
1194 		sk_tx_queue_clear(sk);
1195 	}
1196 
1197 	return sk;
1198 
1199 out_free_sec:
1200 	security_sk_free(sk);
1201 out_free:
1202 	if (slab != NULL)
1203 		kmem_cache_free(slab, sk);
1204 	else
1205 		kfree(sk);
1206 	return NULL;
1207 }
1208 
1209 static void sk_prot_free(struct proto *prot, struct sock *sk)
1210 {
1211 	struct kmem_cache *slab;
1212 	struct module *owner;
1213 
1214 	owner = prot->owner;
1215 	slab = prot->slab;
1216 
1217 	security_sk_free(sk);
1218 	if (slab != NULL)
1219 		kmem_cache_free(slab, sk);
1220 	else
1221 		kfree(sk);
1222 	module_put(owner);
1223 }
1224 
1225 #ifdef CONFIG_CGROUPS
1226 void sock_update_classid(struct sock *sk)
1227 {
1228 	u32 classid;
1229 
1230 	rcu_read_lock();  /* doing current task, which cannot vanish. */
1231 	classid = task_cls_classid(current);
1232 	rcu_read_unlock();
1233 	if (classid && classid != sk->sk_classid)
1234 		sk->sk_classid = classid;
1235 }
1236 EXPORT_SYMBOL(sock_update_classid);
1237 
1238 void sock_update_netprioidx(struct sock *sk, struct task_struct *task)
1239 {
1240 	if (in_interrupt())
1241 		return;
1242 
1243 	sk->sk_cgrp_prioidx = task_netprioidx(task);
1244 }
1245 EXPORT_SYMBOL_GPL(sock_update_netprioidx);
1246 #endif
1247 
1248 /**
1249  *	sk_alloc - All socket objects are allocated here
1250  *	@net: the applicable net namespace
1251  *	@family: protocol family
1252  *	@priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
1253  *	@prot: struct proto associated with this new sock instance
1254  */
1255 struct sock *sk_alloc(struct net *net, int family, gfp_t priority,
1256 		      struct proto *prot)
1257 {
1258 	struct sock *sk;
1259 
1260 	sk = sk_prot_alloc(prot, priority | __GFP_ZERO, family);
1261 	if (sk) {
1262 		sk->sk_family = family;
1263 		/*
1264 		 * See comment in struct sock definition to understand
1265 		 * why we need sk_prot_creator -acme
1266 		 */
1267 		sk->sk_prot = sk->sk_prot_creator = prot;
1268 		sock_lock_init(sk);
1269 		sock_net_set(sk, get_net(net));
1270 		atomic_set(&sk->sk_wmem_alloc, 1);
1271 
1272 		sock_update_classid(sk);
1273 		sock_update_netprioidx(sk, current);
1274 	}
1275 
1276 	return sk;
1277 }
1278 EXPORT_SYMBOL(sk_alloc);
1279 
1280 static void __sk_free(struct sock *sk)
1281 {
1282 	struct sk_filter *filter;
1283 
1284 	if (sk->sk_destruct)
1285 		sk->sk_destruct(sk);
1286 
1287 	filter = rcu_dereference_check(sk->sk_filter,
1288 				       atomic_read(&sk->sk_wmem_alloc) == 0);
1289 	if (filter) {
1290 		sk_filter_uncharge(sk, filter);
1291 		RCU_INIT_POINTER(sk->sk_filter, NULL);
1292 	}
1293 
1294 	sock_disable_timestamp(sk, SK_FLAGS_TIMESTAMP);
1295 
1296 	if (atomic_read(&sk->sk_omem_alloc))
1297 		pr_debug("%s: optmem leakage (%d bytes) detected\n",
1298 			 __func__, atomic_read(&sk->sk_omem_alloc));
1299 
1300 	if (sk->sk_peer_cred)
1301 		put_cred(sk->sk_peer_cred);
1302 	put_pid(sk->sk_peer_pid);
1303 	put_net(sock_net(sk));
1304 	sk_prot_free(sk->sk_prot_creator, sk);
1305 }
1306 
1307 void sk_free(struct sock *sk)
1308 {
1309 	/*
1310 	 * We subtract one from sk_wmem_alloc and can know if
1311 	 * some packets are still in some tx queue.
1312 	 * If not null, sock_wfree() will call __sk_free(sk) later
1313 	 */
1314 	if (atomic_dec_and_test(&sk->sk_wmem_alloc))
1315 		__sk_free(sk);
1316 }
1317 EXPORT_SYMBOL(sk_free);
1318 
1319 /*
1320  * Last sock_put should drop reference to sk->sk_net. It has already
1321  * been dropped in sk_change_net. Taking reference to stopping namespace
1322  * is not an option.
1323  * Take reference to a socket to remove it from hash _alive_ and after that
1324  * destroy it in the context of init_net.
1325  */
1326 void sk_release_kernel(struct sock *sk)
1327 {
1328 	if (sk == NULL || sk->sk_socket == NULL)
1329 		return;
1330 
1331 	sock_hold(sk);
1332 	sock_release(sk->sk_socket);
1333 	release_net(sock_net(sk));
1334 	sock_net_set(sk, get_net(&init_net));
1335 	sock_put(sk);
1336 }
1337 EXPORT_SYMBOL(sk_release_kernel);
1338 
1339 static void sk_update_clone(const struct sock *sk, struct sock *newsk)
1340 {
1341 	if (mem_cgroup_sockets_enabled && sk->sk_cgrp)
1342 		sock_update_memcg(newsk);
1343 }
1344 
1345 /**
1346  *	sk_clone_lock - clone a socket, and lock its clone
1347  *	@sk: the socket to clone
1348  *	@priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
1349  *
1350  *	Caller must unlock socket even in error path (bh_unlock_sock(newsk))
1351  */
1352 struct sock *sk_clone_lock(const struct sock *sk, const gfp_t priority)
1353 {
1354 	struct sock *newsk;
1355 
1356 	newsk = sk_prot_alloc(sk->sk_prot, priority, sk->sk_family);
1357 	if (newsk != NULL) {
1358 		struct sk_filter *filter;
1359 
1360 		sock_copy(newsk, sk);
1361 
1362 		/* SANITY */
1363 		get_net(sock_net(newsk));
1364 		sk_node_init(&newsk->sk_node);
1365 		sock_lock_init(newsk);
1366 		bh_lock_sock(newsk);
1367 		newsk->sk_backlog.head	= newsk->sk_backlog.tail = NULL;
1368 		newsk->sk_backlog.len = 0;
1369 
1370 		atomic_set(&newsk->sk_rmem_alloc, 0);
1371 		/*
1372 		 * sk_wmem_alloc set to one (see sk_free() and sock_wfree())
1373 		 */
1374 		atomic_set(&newsk->sk_wmem_alloc, 1);
1375 		atomic_set(&newsk->sk_omem_alloc, 0);
1376 		skb_queue_head_init(&newsk->sk_receive_queue);
1377 		skb_queue_head_init(&newsk->sk_write_queue);
1378 #ifdef CONFIG_NET_DMA
1379 		skb_queue_head_init(&newsk->sk_async_wait_queue);
1380 #endif
1381 
1382 		spin_lock_init(&newsk->sk_dst_lock);
1383 		rwlock_init(&newsk->sk_callback_lock);
1384 		lockdep_set_class_and_name(&newsk->sk_callback_lock,
1385 				af_callback_keys + newsk->sk_family,
1386 				af_family_clock_key_strings[newsk->sk_family]);
1387 
1388 		newsk->sk_dst_cache	= NULL;
1389 		newsk->sk_wmem_queued	= 0;
1390 		newsk->sk_forward_alloc = 0;
1391 		newsk->sk_send_head	= NULL;
1392 		newsk->sk_userlocks	= sk->sk_userlocks & ~SOCK_BINDPORT_LOCK;
1393 
1394 		sock_reset_flag(newsk, SOCK_DONE);
1395 		skb_queue_head_init(&newsk->sk_error_queue);
1396 
1397 		filter = rcu_dereference_protected(newsk->sk_filter, 1);
1398 		if (filter != NULL)
1399 			sk_filter_charge(newsk, filter);
1400 
1401 		if (unlikely(xfrm_sk_clone_policy(newsk))) {
1402 			/* It is still raw copy of parent, so invalidate
1403 			 * destructor and make plain sk_free() */
1404 			newsk->sk_destruct = NULL;
1405 			bh_unlock_sock(newsk);
1406 			sk_free(newsk);
1407 			newsk = NULL;
1408 			goto out;
1409 		}
1410 
1411 		newsk->sk_err	   = 0;
1412 		newsk->sk_priority = 0;
1413 		/*
1414 		 * Before updating sk_refcnt, we must commit prior changes to memory
1415 		 * (Documentation/RCU/rculist_nulls.txt for details)
1416 		 */
1417 		smp_wmb();
1418 		atomic_set(&newsk->sk_refcnt, 2);
1419 
1420 		/*
1421 		 * Increment the counter in the same struct proto as the master
1422 		 * sock (sk_refcnt_debug_inc uses newsk->sk_prot->socks, that
1423 		 * is the same as sk->sk_prot->socks, as this field was copied
1424 		 * with memcpy).
1425 		 *
1426 		 * This _changes_ the previous behaviour, where
1427 		 * tcp_create_openreq_child always was incrementing the
1428 		 * equivalent to tcp_prot->socks (inet_sock_nr), so this have
1429 		 * to be taken into account in all callers. -acme
1430 		 */
1431 		sk_refcnt_debug_inc(newsk);
1432 		sk_set_socket(newsk, NULL);
1433 		newsk->sk_wq = NULL;
1434 
1435 		sk_update_clone(sk, newsk);
1436 
1437 		if (newsk->sk_prot->sockets_allocated)
1438 			sk_sockets_allocated_inc(newsk);
1439 
1440 		if (newsk->sk_flags & SK_FLAGS_TIMESTAMP)
1441 			net_enable_timestamp();
1442 	}
1443 out:
1444 	return newsk;
1445 }
1446 EXPORT_SYMBOL_GPL(sk_clone_lock);
1447 
1448 void sk_setup_caps(struct sock *sk, struct dst_entry *dst)
1449 {
1450 	__sk_dst_set(sk, dst);
1451 	sk->sk_route_caps = dst->dev->features;
1452 	if (sk->sk_route_caps & NETIF_F_GSO)
1453 		sk->sk_route_caps |= NETIF_F_GSO_SOFTWARE;
1454 	sk->sk_route_caps &= ~sk->sk_route_nocaps;
1455 	if (sk_can_gso(sk)) {
1456 		if (dst->header_len) {
1457 			sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
1458 		} else {
1459 			sk->sk_route_caps |= NETIF_F_SG | NETIF_F_HW_CSUM;
1460 			sk->sk_gso_max_size = dst->dev->gso_max_size;
1461 			sk->sk_gso_max_segs = dst->dev->gso_max_segs;
1462 		}
1463 	}
1464 }
1465 EXPORT_SYMBOL_GPL(sk_setup_caps);
1466 
1467 void __init sk_init(void)
1468 {
1469 	if (totalram_pages <= 4096) {
1470 		sysctl_wmem_max = 32767;
1471 		sysctl_rmem_max = 32767;
1472 		sysctl_wmem_default = 32767;
1473 		sysctl_rmem_default = 32767;
1474 	} else if (totalram_pages >= 131072) {
1475 		sysctl_wmem_max = 131071;
1476 		sysctl_rmem_max = 131071;
1477 	}
1478 }
1479 
1480 /*
1481  *	Simple resource managers for sockets.
1482  */
1483 
1484 
1485 /*
1486  * Write buffer destructor automatically called from kfree_skb.
1487  */
1488 void sock_wfree(struct sk_buff *skb)
1489 {
1490 	struct sock *sk = skb->sk;
1491 	unsigned int len = skb->truesize;
1492 
1493 	if (!sock_flag(sk, SOCK_USE_WRITE_QUEUE)) {
1494 		/*
1495 		 * Keep a reference on sk_wmem_alloc, this will be released
1496 		 * after sk_write_space() call
1497 		 */
1498 		atomic_sub(len - 1, &sk->sk_wmem_alloc);
1499 		sk->sk_write_space(sk);
1500 		len = 1;
1501 	}
1502 	/*
1503 	 * if sk_wmem_alloc reaches 0, we must finish what sk_free()
1504 	 * could not do because of in-flight packets
1505 	 */
1506 	if (atomic_sub_and_test(len, &sk->sk_wmem_alloc))
1507 		__sk_free(sk);
1508 }
1509 EXPORT_SYMBOL(sock_wfree);
1510 
1511 /*
1512  * Read buffer destructor automatically called from kfree_skb.
1513  */
1514 void sock_rfree(struct sk_buff *skb)
1515 {
1516 	struct sock *sk = skb->sk;
1517 	unsigned int len = skb->truesize;
1518 
1519 	atomic_sub(len, &sk->sk_rmem_alloc);
1520 	sk_mem_uncharge(sk, len);
1521 }
1522 EXPORT_SYMBOL(sock_rfree);
1523 
1524 void sock_edemux(struct sk_buff *skb)
1525 {
1526 	sock_put(skb->sk);
1527 }
1528 EXPORT_SYMBOL(sock_edemux);
1529 
1530 int sock_i_uid(struct sock *sk)
1531 {
1532 	int uid;
1533 
1534 	read_lock_bh(&sk->sk_callback_lock);
1535 	uid = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_uid : 0;
1536 	read_unlock_bh(&sk->sk_callback_lock);
1537 	return uid;
1538 }
1539 EXPORT_SYMBOL(sock_i_uid);
1540 
1541 unsigned long sock_i_ino(struct sock *sk)
1542 {
1543 	unsigned long ino;
1544 
1545 	read_lock_bh(&sk->sk_callback_lock);
1546 	ino = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_ino : 0;
1547 	read_unlock_bh(&sk->sk_callback_lock);
1548 	return ino;
1549 }
1550 EXPORT_SYMBOL(sock_i_ino);
1551 
1552 /*
1553  * Allocate a skb from the socket's send buffer.
1554  */
1555 struct sk_buff *sock_wmalloc(struct sock *sk, unsigned long size, int force,
1556 			     gfp_t priority)
1557 {
1558 	if (force || atomic_read(&sk->sk_wmem_alloc) < sk->sk_sndbuf) {
1559 		struct sk_buff *skb = alloc_skb(size, priority);
1560 		if (skb) {
1561 			skb_set_owner_w(skb, sk);
1562 			return skb;
1563 		}
1564 	}
1565 	return NULL;
1566 }
1567 EXPORT_SYMBOL(sock_wmalloc);
1568 
1569 /*
1570  * Allocate a skb from the socket's receive buffer.
1571  */
1572 struct sk_buff *sock_rmalloc(struct sock *sk, unsigned long size, int force,
1573 			     gfp_t priority)
1574 {
1575 	if (force || atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf) {
1576 		struct sk_buff *skb = alloc_skb(size, priority);
1577 		if (skb) {
1578 			skb_set_owner_r(skb, sk);
1579 			return skb;
1580 		}
1581 	}
1582 	return NULL;
1583 }
1584 
1585 /*
1586  * Allocate a memory block from the socket's option memory buffer.
1587  */
1588 void *sock_kmalloc(struct sock *sk, int size, gfp_t priority)
1589 {
1590 	if ((unsigned int)size <= sysctl_optmem_max &&
1591 	    atomic_read(&sk->sk_omem_alloc) + size < sysctl_optmem_max) {
1592 		void *mem;
1593 		/* First do the add, to avoid the race if kmalloc
1594 		 * might sleep.
1595 		 */
1596 		atomic_add(size, &sk->sk_omem_alloc);
1597 		mem = kmalloc(size, priority);
1598 		if (mem)
1599 			return mem;
1600 		atomic_sub(size, &sk->sk_omem_alloc);
1601 	}
1602 	return NULL;
1603 }
1604 EXPORT_SYMBOL(sock_kmalloc);
1605 
1606 /*
1607  * Free an option memory block.
1608  */
1609 void sock_kfree_s(struct sock *sk, void *mem, int size)
1610 {
1611 	kfree(mem);
1612 	atomic_sub(size, &sk->sk_omem_alloc);
1613 }
1614 EXPORT_SYMBOL(sock_kfree_s);
1615 
1616 /* It is almost wait_for_tcp_memory minus release_sock/lock_sock.
1617    I think, these locks should be removed for datagram sockets.
1618  */
1619 static long sock_wait_for_wmem(struct sock *sk, long timeo)
1620 {
1621 	DEFINE_WAIT(wait);
1622 
1623 	clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
1624 	for (;;) {
1625 		if (!timeo)
1626 			break;
1627 		if (signal_pending(current))
1628 			break;
1629 		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1630 		prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
1631 		if (atomic_read(&sk->sk_wmem_alloc) < sk->sk_sndbuf)
1632 			break;
1633 		if (sk->sk_shutdown & SEND_SHUTDOWN)
1634 			break;
1635 		if (sk->sk_err)
1636 			break;
1637 		timeo = schedule_timeout(timeo);
1638 	}
1639 	finish_wait(sk_sleep(sk), &wait);
1640 	return timeo;
1641 }
1642 
1643 
1644 /*
1645  *	Generic send/receive buffer handlers
1646  */
1647 
1648 struct sk_buff *sock_alloc_send_pskb(struct sock *sk, unsigned long header_len,
1649 				     unsigned long data_len, int noblock,
1650 				     int *errcode)
1651 {
1652 	struct sk_buff *skb;
1653 	gfp_t gfp_mask;
1654 	long timeo;
1655 	int err;
1656 	int npages = (data_len + (PAGE_SIZE - 1)) >> PAGE_SHIFT;
1657 
1658 	err = -EMSGSIZE;
1659 	if (npages > MAX_SKB_FRAGS)
1660 		goto failure;
1661 
1662 	gfp_mask = sk->sk_allocation;
1663 	if (gfp_mask & __GFP_WAIT)
1664 		gfp_mask |= __GFP_REPEAT;
1665 
1666 	timeo = sock_sndtimeo(sk, noblock);
1667 	while (1) {
1668 		err = sock_error(sk);
1669 		if (err != 0)
1670 			goto failure;
1671 
1672 		err = -EPIPE;
1673 		if (sk->sk_shutdown & SEND_SHUTDOWN)
1674 			goto failure;
1675 
1676 		if (atomic_read(&sk->sk_wmem_alloc) < sk->sk_sndbuf) {
1677 			skb = alloc_skb(header_len, gfp_mask);
1678 			if (skb) {
1679 				int i;
1680 
1681 				/* No pages, we're done... */
1682 				if (!data_len)
1683 					break;
1684 
1685 				skb->truesize += data_len;
1686 				skb_shinfo(skb)->nr_frags = npages;
1687 				for (i = 0; i < npages; i++) {
1688 					struct page *page;
1689 
1690 					page = alloc_pages(sk->sk_allocation, 0);
1691 					if (!page) {
1692 						err = -ENOBUFS;
1693 						skb_shinfo(skb)->nr_frags = i;
1694 						kfree_skb(skb);
1695 						goto failure;
1696 					}
1697 
1698 					__skb_fill_page_desc(skb, i,
1699 							page, 0,
1700 							(data_len >= PAGE_SIZE ?
1701 							 PAGE_SIZE :
1702 							 data_len));
1703 					data_len -= PAGE_SIZE;
1704 				}
1705 
1706 				/* Full success... */
1707 				break;
1708 			}
1709 			err = -ENOBUFS;
1710 			goto failure;
1711 		}
1712 		set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
1713 		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1714 		err = -EAGAIN;
1715 		if (!timeo)
1716 			goto failure;
1717 		if (signal_pending(current))
1718 			goto interrupted;
1719 		timeo = sock_wait_for_wmem(sk, timeo);
1720 	}
1721 
1722 	skb_set_owner_w(skb, sk);
1723 	return skb;
1724 
1725 interrupted:
1726 	err = sock_intr_errno(timeo);
1727 failure:
1728 	*errcode = err;
1729 	return NULL;
1730 }
1731 EXPORT_SYMBOL(sock_alloc_send_pskb);
1732 
1733 struct sk_buff *sock_alloc_send_skb(struct sock *sk, unsigned long size,
1734 				    int noblock, int *errcode)
1735 {
1736 	return sock_alloc_send_pskb(sk, size, 0, noblock, errcode);
1737 }
1738 EXPORT_SYMBOL(sock_alloc_send_skb);
1739 
1740 static void __lock_sock(struct sock *sk)
1741 	__releases(&sk->sk_lock.slock)
1742 	__acquires(&sk->sk_lock.slock)
1743 {
1744 	DEFINE_WAIT(wait);
1745 
1746 	for (;;) {
1747 		prepare_to_wait_exclusive(&sk->sk_lock.wq, &wait,
1748 					TASK_UNINTERRUPTIBLE);
1749 		spin_unlock_bh(&sk->sk_lock.slock);
1750 		schedule();
1751 		spin_lock_bh(&sk->sk_lock.slock);
1752 		if (!sock_owned_by_user(sk))
1753 			break;
1754 	}
1755 	finish_wait(&sk->sk_lock.wq, &wait);
1756 }
1757 
1758 static void __release_sock(struct sock *sk)
1759 	__releases(&sk->sk_lock.slock)
1760 	__acquires(&sk->sk_lock.slock)
1761 {
1762 	struct sk_buff *skb = sk->sk_backlog.head;
1763 
1764 	do {
1765 		sk->sk_backlog.head = sk->sk_backlog.tail = NULL;
1766 		bh_unlock_sock(sk);
1767 
1768 		do {
1769 			struct sk_buff *next = skb->next;
1770 
1771 			prefetch(next);
1772 			WARN_ON_ONCE(skb_dst_is_noref(skb));
1773 			skb->next = NULL;
1774 			sk_backlog_rcv(sk, skb);
1775 
1776 			/*
1777 			 * We are in process context here with softirqs
1778 			 * disabled, use cond_resched_softirq() to preempt.
1779 			 * This is safe to do because we've taken the backlog
1780 			 * queue private:
1781 			 */
1782 			cond_resched_softirq();
1783 
1784 			skb = next;
1785 		} while (skb != NULL);
1786 
1787 		bh_lock_sock(sk);
1788 	} while ((skb = sk->sk_backlog.head) != NULL);
1789 
1790 	/*
1791 	 * Doing the zeroing here guarantee we can not loop forever
1792 	 * while a wild producer attempts to flood us.
1793 	 */
1794 	sk->sk_backlog.len = 0;
1795 }
1796 
1797 /**
1798  * sk_wait_data - wait for data to arrive at sk_receive_queue
1799  * @sk:    sock to wait on
1800  * @timeo: for how long
1801  *
1802  * Now socket state including sk->sk_err is changed only under lock,
1803  * hence we may omit checks after joining wait queue.
1804  * We check receive queue before schedule() only as optimization;
1805  * it is very likely that release_sock() added new data.
1806  */
1807 int sk_wait_data(struct sock *sk, long *timeo)
1808 {
1809 	int rc;
1810 	DEFINE_WAIT(wait);
1811 
1812 	prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
1813 	set_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
1814 	rc = sk_wait_event(sk, timeo, !skb_queue_empty(&sk->sk_receive_queue));
1815 	clear_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
1816 	finish_wait(sk_sleep(sk), &wait);
1817 	return rc;
1818 }
1819 EXPORT_SYMBOL(sk_wait_data);
1820 
1821 /**
1822  *	__sk_mem_schedule - increase sk_forward_alloc and memory_allocated
1823  *	@sk: socket
1824  *	@size: memory size to allocate
1825  *	@kind: allocation type
1826  *
1827  *	If kind is SK_MEM_SEND, it means wmem allocation. Otherwise it means
1828  *	rmem allocation. This function assumes that protocols which have
1829  *	memory_pressure use sk_wmem_queued as write buffer accounting.
1830  */
1831 int __sk_mem_schedule(struct sock *sk, int size, int kind)
1832 {
1833 	struct proto *prot = sk->sk_prot;
1834 	int amt = sk_mem_pages(size);
1835 	long allocated;
1836 	int parent_status = UNDER_LIMIT;
1837 
1838 	sk->sk_forward_alloc += amt * SK_MEM_QUANTUM;
1839 
1840 	allocated = sk_memory_allocated_add(sk, amt, &parent_status);
1841 
1842 	/* Under limit. */
1843 	if (parent_status == UNDER_LIMIT &&
1844 			allocated <= sk_prot_mem_limits(sk, 0)) {
1845 		sk_leave_memory_pressure(sk);
1846 		return 1;
1847 	}
1848 
1849 	/* Under pressure. (we or our parents) */
1850 	if ((parent_status > SOFT_LIMIT) ||
1851 			allocated > sk_prot_mem_limits(sk, 1))
1852 		sk_enter_memory_pressure(sk);
1853 
1854 	/* Over hard limit (we or our parents) */
1855 	if ((parent_status == OVER_LIMIT) ||
1856 			(allocated > sk_prot_mem_limits(sk, 2)))
1857 		goto suppress_allocation;
1858 
1859 	/* guarantee minimum buffer size under pressure */
1860 	if (kind == SK_MEM_RECV) {
1861 		if (atomic_read(&sk->sk_rmem_alloc) < prot->sysctl_rmem[0])
1862 			return 1;
1863 
1864 	} else { /* SK_MEM_SEND */
1865 		if (sk->sk_type == SOCK_STREAM) {
1866 			if (sk->sk_wmem_queued < prot->sysctl_wmem[0])
1867 				return 1;
1868 		} else if (atomic_read(&sk->sk_wmem_alloc) <
1869 			   prot->sysctl_wmem[0])
1870 				return 1;
1871 	}
1872 
1873 	if (sk_has_memory_pressure(sk)) {
1874 		int alloc;
1875 
1876 		if (!sk_under_memory_pressure(sk))
1877 			return 1;
1878 		alloc = sk_sockets_allocated_read_positive(sk);
1879 		if (sk_prot_mem_limits(sk, 2) > alloc *
1880 		    sk_mem_pages(sk->sk_wmem_queued +
1881 				 atomic_read(&sk->sk_rmem_alloc) +
1882 				 sk->sk_forward_alloc))
1883 			return 1;
1884 	}
1885 
1886 suppress_allocation:
1887 
1888 	if (kind == SK_MEM_SEND && sk->sk_type == SOCK_STREAM) {
1889 		sk_stream_moderate_sndbuf(sk);
1890 
1891 		/* Fail only if socket is _under_ its sndbuf.
1892 		 * In this case we cannot block, so that we have to fail.
1893 		 */
1894 		if (sk->sk_wmem_queued + size >= sk->sk_sndbuf)
1895 			return 1;
1896 	}
1897 
1898 	trace_sock_exceed_buf_limit(sk, prot, allocated);
1899 
1900 	/* Alas. Undo changes. */
1901 	sk->sk_forward_alloc -= amt * SK_MEM_QUANTUM;
1902 
1903 	sk_memory_allocated_sub(sk, amt);
1904 
1905 	return 0;
1906 }
1907 EXPORT_SYMBOL(__sk_mem_schedule);
1908 
1909 /**
1910  *	__sk_reclaim - reclaim memory_allocated
1911  *	@sk: socket
1912  */
1913 void __sk_mem_reclaim(struct sock *sk)
1914 {
1915 	sk_memory_allocated_sub(sk,
1916 				sk->sk_forward_alloc >> SK_MEM_QUANTUM_SHIFT);
1917 	sk->sk_forward_alloc &= SK_MEM_QUANTUM - 1;
1918 
1919 	if (sk_under_memory_pressure(sk) &&
1920 	    (sk_memory_allocated(sk) < sk_prot_mem_limits(sk, 0)))
1921 		sk_leave_memory_pressure(sk);
1922 }
1923 EXPORT_SYMBOL(__sk_mem_reclaim);
1924 
1925 
1926 /*
1927  * Set of default routines for initialising struct proto_ops when
1928  * the protocol does not support a particular function. In certain
1929  * cases where it makes no sense for a protocol to have a "do nothing"
1930  * function, some default processing is provided.
1931  */
1932 
1933 int sock_no_bind(struct socket *sock, struct sockaddr *saddr, int len)
1934 {
1935 	return -EOPNOTSUPP;
1936 }
1937 EXPORT_SYMBOL(sock_no_bind);
1938 
1939 int sock_no_connect(struct socket *sock, struct sockaddr *saddr,
1940 		    int len, int flags)
1941 {
1942 	return -EOPNOTSUPP;
1943 }
1944 EXPORT_SYMBOL(sock_no_connect);
1945 
1946 int sock_no_socketpair(struct socket *sock1, struct socket *sock2)
1947 {
1948 	return -EOPNOTSUPP;
1949 }
1950 EXPORT_SYMBOL(sock_no_socketpair);
1951 
1952 int sock_no_accept(struct socket *sock, struct socket *newsock, int flags)
1953 {
1954 	return -EOPNOTSUPP;
1955 }
1956 EXPORT_SYMBOL(sock_no_accept);
1957 
1958 int sock_no_getname(struct socket *sock, struct sockaddr *saddr,
1959 		    int *len, int peer)
1960 {
1961 	return -EOPNOTSUPP;
1962 }
1963 EXPORT_SYMBOL(sock_no_getname);
1964 
1965 unsigned int sock_no_poll(struct file *file, struct socket *sock, poll_table *pt)
1966 {
1967 	return 0;
1968 }
1969 EXPORT_SYMBOL(sock_no_poll);
1970 
1971 int sock_no_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
1972 {
1973 	return -EOPNOTSUPP;
1974 }
1975 EXPORT_SYMBOL(sock_no_ioctl);
1976 
1977 int sock_no_listen(struct socket *sock, int backlog)
1978 {
1979 	return -EOPNOTSUPP;
1980 }
1981 EXPORT_SYMBOL(sock_no_listen);
1982 
1983 int sock_no_shutdown(struct socket *sock, int how)
1984 {
1985 	return -EOPNOTSUPP;
1986 }
1987 EXPORT_SYMBOL(sock_no_shutdown);
1988 
1989 int sock_no_setsockopt(struct socket *sock, int level, int optname,
1990 		    char __user *optval, unsigned int optlen)
1991 {
1992 	return -EOPNOTSUPP;
1993 }
1994 EXPORT_SYMBOL(sock_no_setsockopt);
1995 
1996 int sock_no_getsockopt(struct socket *sock, int level, int optname,
1997 		    char __user *optval, int __user *optlen)
1998 {
1999 	return -EOPNOTSUPP;
2000 }
2001 EXPORT_SYMBOL(sock_no_getsockopt);
2002 
2003 int sock_no_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *m,
2004 		    size_t len)
2005 {
2006 	return -EOPNOTSUPP;
2007 }
2008 EXPORT_SYMBOL(sock_no_sendmsg);
2009 
2010 int sock_no_recvmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *m,
2011 		    size_t len, int flags)
2012 {
2013 	return -EOPNOTSUPP;
2014 }
2015 EXPORT_SYMBOL(sock_no_recvmsg);
2016 
2017 int sock_no_mmap(struct file *file, struct socket *sock, struct vm_area_struct *vma)
2018 {
2019 	/* Mirror missing mmap method error code */
2020 	return -ENODEV;
2021 }
2022 EXPORT_SYMBOL(sock_no_mmap);
2023 
2024 ssize_t sock_no_sendpage(struct socket *sock, struct page *page, int offset, size_t size, int flags)
2025 {
2026 	ssize_t res;
2027 	struct msghdr msg = {.msg_flags = flags};
2028 	struct kvec iov;
2029 	char *kaddr = kmap(page);
2030 	iov.iov_base = kaddr + offset;
2031 	iov.iov_len = size;
2032 	res = kernel_sendmsg(sock, &msg, &iov, 1, size);
2033 	kunmap(page);
2034 	return res;
2035 }
2036 EXPORT_SYMBOL(sock_no_sendpage);
2037 
2038 /*
2039  *	Default Socket Callbacks
2040  */
2041 
2042 static void sock_def_wakeup(struct sock *sk)
2043 {
2044 	struct socket_wq *wq;
2045 
2046 	rcu_read_lock();
2047 	wq = rcu_dereference(sk->sk_wq);
2048 	if (wq_has_sleeper(wq))
2049 		wake_up_interruptible_all(&wq->wait);
2050 	rcu_read_unlock();
2051 }
2052 
2053 static void sock_def_error_report(struct sock *sk)
2054 {
2055 	struct socket_wq *wq;
2056 
2057 	rcu_read_lock();
2058 	wq = rcu_dereference(sk->sk_wq);
2059 	if (wq_has_sleeper(wq))
2060 		wake_up_interruptible_poll(&wq->wait, POLLERR);
2061 	sk_wake_async(sk, SOCK_WAKE_IO, POLL_ERR);
2062 	rcu_read_unlock();
2063 }
2064 
2065 static void sock_def_readable(struct sock *sk, int len)
2066 {
2067 	struct socket_wq *wq;
2068 
2069 	rcu_read_lock();
2070 	wq = rcu_dereference(sk->sk_wq);
2071 	if (wq_has_sleeper(wq))
2072 		wake_up_interruptible_sync_poll(&wq->wait, POLLIN | POLLPRI |
2073 						POLLRDNORM | POLLRDBAND);
2074 	sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
2075 	rcu_read_unlock();
2076 }
2077 
2078 static void sock_def_write_space(struct sock *sk)
2079 {
2080 	struct socket_wq *wq;
2081 
2082 	rcu_read_lock();
2083 
2084 	/* Do not wake up a writer until he can make "significant"
2085 	 * progress.  --DaveM
2086 	 */
2087 	if ((atomic_read(&sk->sk_wmem_alloc) << 1) <= sk->sk_sndbuf) {
2088 		wq = rcu_dereference(sk->sk_wq);
2089 		if (wq_has_sleeper(wq))
2090 			wake_up_interruptible_sync_poll(&wq->wait, POLLOUT |
2091 						POLLWRNORM | POLLWRBAND);
2092 
2093 		/* Should agree with poll, otherwise some programs break */
2094 		if (sock_writeable(sk))
2095 			sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
2096 	}
2097 
2098 	rcu_read_unlock();
2099 }
2100 
2101 static void sock_def_destruct(struct sock *sk)
2102 {
2103 	kfree(sk->sk_protinfo);
2104 }
2105 
2106 void sk_send_sigurg(struct sock *sk)
2107 {
2108 	if (sk->sk_socket && sk->sk_socket->file)
2109 		if (send_sigurg(&sk->sk_socket->file->f_owner))
2110 			sk_wake_async(sk, SOCK_WAKE_URG, POLL_PRI);
2111 }
2112 EXPORT_SYMBOL(sk_send_sigurg);
2113 
2114 void sk_reset_timer(struct sock *sk, struct timer_list* timer,
2115 		    unsigned long expires)
2116 {
2117 	if (!mod_timer(timer, expires))
2118 		sock_hold(sk);
2119 }
2120 EXPORT_SYMBOL(sk_reset_timer);
2121 
2122 void sk_stop_timer(struct sock *sk, struct timer_list* timer)
2123 {
2124 	if (timer_pending(timer) && del_timer(timer))
2125 		__sock_put(sk);
2126 }
2127 EXPORT_SYMBOL(sk_stop_timer);
2128 
2129 void sock_init_data(struct socket *sock, struct sock *sk)
2130 {
2131 	skb_queue_head_init(&sk->sk_receive_queue);
2132 	skb_queue_head_init(&sk->sk_write_queue);
2133 	skb_queue_head_init(&sk->sk_error_queue);
2134 #ifdef CONFIG_NET_DMA
2135 	skb_queue_head_init(&sk->sk_async_wait_queue);
2136 #endif
2137 
2138 	sk->sk_send_head	=	NULL;
2139 
2140 	init_timer(&sk->sk_timer);
2141 
2142 	sk->sk_allocation	=	GFP_KERNEL;
2143 	sk->sk_rcvbuf		=	sysctl_rmem_default;
2144 	sk->sk_sndbuf		=	sysctl_wmem_default;
2145 	sk->sk_state		=	TCP_CLOSE;
2146 	sk_set_socket(sk, sock);
2147 
2148 	sock_set_flag(sk, SOCK_ZAPPED);
2149 
2150 	if (sock) {
2151 		sk->sk_type	=	sock->type;
2152 		sk->sk_wq	=	sock->wq;
2153 		sock->sk	=	sk;
2154 	} else
2155 		sk->sk_wq	=	NULL;
2156 
2157 	spin_lock_init(&sk->sk_dst_lock);
2158 	rwlock_init(&sk->sk_callback_lock);
2159 	lockdep_set_class_and_name(&sk->sk_callback_lock,
2160 			af_callback_keys + sk->sk_family,
2161 			af_family_clock_key_strings[sk->sk_family]);
2162 
2163 	sk->sk_state_change	=	sock_def_wakeup;
2164 	sk->sk_data_ready	=	sock_def_readable;
2165 	sk->sk_write_space	=	sock_def_write_space;
2166 	sk->sk_error_report	=	sock_def_error_report;
2167 	sk->sk_destruct		=	sock_def_destruct;
2168 
2169 	sk->sk_sndmsg_page	=	NULL;
2170 	sk->sk_sndmsg_off	=	0;
2171 	sk->sk_peek_off		=	-1;
2172 
2173 	sk->sk_peer_pid 	=	NULL;
2174 	sk->sk_peer_cred	=	NULL;
2175 	sk->sk_write_pending	=	0;
2176 	sk->sk_rcvlowat		=	1;
2177 	sk->sk_rcvtimeo		=	MAX_SCHEDULE_TIMEOUT;
2178 	sk->sk_sndtimeo		=	MAX_SCHEDULE_TIMEOUT;
2179 
2180 	sk->sk_stamp = ktime_set(-1L, 0);
2181 
2182 	/*
2183 	 * Before updating sk_refcnt, we must commit prior changes to memory
2184 	 * (Documentation/RCU/rculist_nulls.txt for details)
2185 	 */
2186 	smp_wmb();
2187 	atomic_set(&sk->sk_refcnt, 1);
2188 	atomic_set(&sk->sk_drops, 0);
2189 }
2190 EXPORT_SYMBOL(sock_init_data);
2191 
2192 void lock_sock_nested(struct sock *sk, int subclass)
2193 {
2194 	might_sleep();
2195 	spin_lock_bh(&sk->sk_lock.slock);
2196 	if (sk->sk_lock.owned)
2197 		__lock_sock(sk);
2198 	sk->sk_lock.owned = 1;
2199 	spin_unlock(&sk->sk_lock.slock);
2200 	/*
2201 	 * The sk_lock has mutex_lock() semantics here:
2202 	 */
2203 	mutex_acquire(&sk->sk_lock.dep_map, subclass, 0, _RET_IP_);
2204 	local_bh_enable();
2205 }
2206 EXPORT_SYMBOL(lock_sock_nested);
2207 
2208 void release_sock(struct sock *sk)
2209 {
2210 	/*
2211 	 * The sk_lock has mutex_unlock() semantics:
2212 	 */
2213 	mutex_release(&sk->sk_lock.dep_map, 1, _RET_IP_);
2214 
2215 	spin_lock_bh(&sk->sk_lock.slock);
2216 	if (sk->sk_backlog.tail)
2217 		__release_sock(sk);
2218 
2219 	if (sk->sk_prot->release_cb)
2220 		sk->sk_prot->release_cb(sk);
2221 
2222 	sk->sk_lock.owned = 0;
2223 	if (waitqueue_active(&sk->sk_lock.wq))
2224 		wake_up(&sk->sk_lock.wq);
2225 	spin_unlock_bh(&sk->sk_lock.slock);
2226 }
2227 EXPORT_SYMBOL(release_sock);
2228 
2229 /**
2230  * lock_sock_fast - fast version of lock_sock
2231  * @sk: socket
2232  *
2233  * This version should be used for very small section, where process wont block
2234  * return false if fast path is taken
2235  *   sk_lock.slock locked, owned = 0, BH disabled
2236  * return true if slow path is taken
2237  *   sk_lock.slock unlocked, owned = 1, BH enabled
2238  */
2239 bool lock_sock_fast(struct sock *sk)
2240 {
2241 	might_sleep();
2242 	spin_lock_bh(&sk->sk_lock.slock);
2243 
2244 	if (!sk->sk_lock.owned)
2245 		/*
2246 		 * Note : We must disable BH
2247 		 */
2248 		return false;
2249 
2250 	__lock_sock(sk);
2251 	sk->sk_lock.owned = 1;
2252 	spin_unlock(&sk->sk_lock.slock);
2253 	/*
2254 	 * The sk_lock has mutex_lock() semantics here:
2255 	 */
2256 	mutex_acquire(&sk->sk_lock.dep_map, 0, 0, _RET_IP_);
2257 	local_bh_enable();
2258 	return true;
2259 }
2260 EXPORT_SYMBOL(lock_sock_fast);
2261 
2262 int sock_get_timestamp(struct sock *sk, struct timeval __user *userstamp)
2263 {
2264 	struct timeval tv;
2265 	if (!sock_flag(sk, SOCK_TIMESTAMP))
2266 		sock_enable_timestamp(sk, SOCK_TIMESTAMP);
2267 	tv = ktime_to_timeval(sk->sk_stamp);
2268 	if (tv.tv_sec == -1)
2269 		return -ENOENT;
2270 	if (tv.tv_sec == 0) {
2271 		sk->sk_stamp = ktime_get_real();
2272 		tv = ktime_to_timeval(sk->sk_stamp);
2273 	}
2274 	return copy_to_user(userstamp, &tv, sizeof(tv)) ? -EFAULT : 0;
2275 }
2276 EXPORT_SYMBOL(sock_get_timestamp);
2277 
2278 int sock_get_timestampns(struct sock *sk, struct timespec __user *userstamp)
2279 {
2280 	struct timespec ts;
2281 	if (!sock_flag(sk, SOCK_TIMESTAMP))
2282 		sock_enable_timestamp(sk, SOCK_TIMESTAMP);
2283 	ts = ktime_to_timespec(sk->sk_stamp);
2284 	if (ts.tv_sec == -1)
2285 		return -ENOENT;
2286 	if (ts.tv_sec == 0) {
2287 		sk->sk_stamp = ktime_get_real();
2288 		ts = ktime_to_timespec(sk->sk_stamp);
2289 	}
2290 	return copy_to_user(userstamp, &ts, sizeof(ts)) ? -EFAULT : 0;
2291 }
2292 EXPORT_SYMBOL(sock_get_timestampns);
2293 
2294 void sock_enable_timestamp(struct sock *sk, int flag)
2295 {
2296 	if (!sock_flag(sk, flag)) {
2297 		unsigned long previous_flags = sk->sk_flags;
2298 
2299 		sock_set_flag(sk, flag);
2300 		/*
2301 		 * we just set one of the two flags which require net
2302 		 * time stamping, but time stamping might have been on
2303 		 * already because of the other one
2304 		 */
2305 		if (!(previous_flags & SK_FLAGS_TIMESTAMP))
2306 			net_enable_timestamp();
2307 	}
2308 }
2309 
2310 /*
2311  *	Get a socket option on an socket.
2312  *
2313  *	FIX: POSIX 1003.1g is very ambiguous here. It states that
2314  *	asynchronous errors should be reported by getsockopt. We assume
2315  *	this means if you specify SO_ERROR (otherwise whats the point of it).
2316  */
2317 int sock_common_getsockopt(struct socket *sock, int level, int optname,
2318 			   char __user *optval, int __user *optlen)
2319 {
2320 	struct sock *sk = sock->sk;
2321 
2322 	return sk->sk_prot->getsockopt(sk, level, optname, optval, optlen);
2323 }
2324 EXPORT_SYMBOL(sock_common_getsockopt);
2325 
2326 #ifdef CONFIG_COMPAT
2327 int compat_sock_common_getsockopt(struct socket *sock, int level, int optname,
2328 				  char __user *optval, int __user *optlen)
2329 {
2330 	struct sock *sk = sock->sk;
2331 
2332 	if (sk->sk_prot->compat_getsockopt != NULL)
2333 		return sk->sk_prot->compat_getsockopt(sk, level, optname,
2334 						      optval, optlen);
2335 	return sk->sk_prot->getsockopt(sk, level, optname, optval, optlen);
2336 }
2337 EXPORT_SYMBOL(compat_sock_common_getsockopt);
2338 #endif
2339 
2340 int sock_common_recvmsg(struct kiocb *iocb, struct socket *sock,
2341 			struct msghdr *msg, size_t size, int flags)
2342 {
2343 	struct sock *sk = sock->sk;
2344 	int addr_len = 0;
2345 	int err;
2346 
2347 	err = sk->sk_prot->recvmsg(iocb, sk, msg, size, flags & MSG_DONTWAIT,
2348 				   flags & ~MSG_DONTWAIT, &addr_len);
2349 	if (err >= 0)
2350 		msg->msg_namelen = addr_len;
2351 	return err;
2352 }
2353 EXPORT_SYMBOL(sock_common_recvmsg);
2354 
2355 /*
2356  *	Set socket options on an inet socket.
2357  */
2358 int sock_common_setsockopt(struct socket *sock, int level, int optname,
2359 			   char __user *optval, unsigned int optlen)
2360 {
2361 	struct sock *sk = sock->sk;
2362 
2363 	return sk->sk_prot->setsockopt(sk, level, optname, optval, optlen);
2364 }
2365 EXPORT_SYMBOL(sock_common_setsockopt);
2366 
2367 #ifdef CONFIG_COMPAT
2368 int compat_sock_common_setsockopt(struct socket *sock, int level, int optname,
2369 				  char __user *optval, unsigned int optlen)
2370 {
2371 	struct sock *sk = sock->sk;
2372 
2373 	if (sk->sk_prot->compat_setsockopt != NULL)
2374 		return sk->sk_prot->compat_setsockopt(sk, level, optname,
2375 						      optval, optlen);
2376 	return sk->sk_prot->setsockopt(sk, level, optname, optval, optlen);
2377 }
2378 EXPORT_SYMBOL(compat_sock_common_setsockopt);
2379 #endif
2380 
2381 void sk_common_release(struct sock *sk)
2382 {
2383 	if (sk->sk_prot->destroy)
2384 		sk->sk_prot->destroy(sk);
2385 
2386 	/*
2387 	 * Observation: when sock_common_release is called, processes have
2388 	 * no access to socket. But net still has.
2389 	 * Step one, detach it from networking:
2390 	 *
2391 	 * A. Remove from hash tables.
2392 	 */
2393 
2394 	sk->sk_prot->unhash(sk);
2395 
2396 	/*
2397 	 * In this point socket cannot receive new packets, but it is possible
2398 	 * that some packets are in flight because some CPU runs receiver and
2399 	 * did hash table lookup before we unhashed socket. They will achieve
2400 	 * receive queue and will be purged by socket destructor.
2401 	 *
2402 	 * Also we still have packets pending on receive queue and probably,
2403 	 * our own packets waiting in device queues. sock_destroy will drain
2404 	 * receive queue, but transmitted packets will delay socket destruction
2405 	 * until the last reference will be released.
2406 	 */
2407 
2408 	sock_orphan(sk);
2409 
2410 	xfrm_sk_free_policy(sk);
2411 
2412 	sk_refcnt_debug_release(sk);
2413 	sock_put(sk);
2414 }
2415 EXPORT_SYMBOL(sk_common_release);
2416 
2417 #ifdef CONFIG_PROC_FS
2418 #define PROTO_INUSE_NR	64	/* should be enough for the first time */
2419 struct prot_inuse {
2420 	int val[PROTO_INUSE_NR];
2421 };
2422 
2423 static DECLARE_BITMAP(proto_inuse_idx, PROTO_INUSE_NR);
2424 
2425 #ifdef CONFIG_NET_NS
2426 void sock_prot_inuse_add(struct net *net, struct proto *prot, int val)
2427 {
2428 	__this_cpu_add(net->core.inuse->val[prot->inuse_idx], val);
2429 }
2430 EXPORT_SYMBOL_GPL(sock_prot_inuse_add);
2431 
2432 int sock_prot_inuse_get(struct net *net, struct proto *prot)
2433 {
2434 	int cpu, idx = prot->inuse_idx;
2435 	int res = 0;
2436 
2437 	for_each_possible_cpu(cpu)
2438 		res += per_cpu_ptr(net->core.inuse, cpu)->val[idx];
2439 
2440 	return res >= 0 ? res : 0;
2441 }
2442 EXPORT_SYMBOL_GPL(sock_prot_inuse_get);
2443 
2444 static int __net_init sock_inuse_init_net(struct net *net)
2445 {
2446 	net->core.inuse = alloc_percpu(struct prot_inuse);
2447 	return net->core.inuse ? 0 : -ENOMEM;
2448 }
2449 
2450 static void __net_exit sock_inuse_exit_net(struct net *net)
2451 {
2452 	free_percpu(net->core.inuse);
2453 }
2454 
2455 static struct pernet_operations net_inuse_ops = {
2456 	.init = sock_inuse_init_net,
2457 	.exit = sock_inuse_exit_net,
2458 };
2459 
2460 static __init int net_inuse_init(void)
2461 {
2462 	if (register_pernet_subsys(&net_inuse_ops))
2463 		panic("Cannot initialize net inuse counters");
2464 
2465 	return 0;
2466 }
2467 
2468 core_initcall(net_inuse_init);
2469 #else
2470 static DEFINE_PER_CPU(struct prot_inuse, prot_inuse);
2471 
2472 void sock_prot_inuse_add(struct net *net, struct proto *prot, int val)
2473 {
2474 	__this_cpu_add(prot_inuse.val[prot->inuse_idx], val);
2475 }
2476 EXPORT_SYMBOL_GPL(sock_prot_inuse_add);
2477 
2478 int sock_prot_inuse_get(struct net *net, struct proto *prot)
2479 {
2480 	int cpu, idx = prot->inuse_idx;
2481 	int res = 0;
2482 
2483 	for_each_possible_cpu(cpu)
2484 		res += per_cpu(prot_inuse, cpu).val[idx];
2485 
2486 	return res >= 0 ? res : 0;
2487 }
2488 EXPORT_SYMBOL_GPL(sock_prot_inuse_get);
2489 #endif
2490 
2491 static void assign_proto_idx(struct proto *prot)
2492 {
2493 	prot->inuse_idx = find_first_zero_bit(proto_inuse_idx, PROTO_INUSE_NR);
2494 
2495 	if (unlikely(prot->inuse_idx == PROTO_INUSE_NR - 1)) {
2496 		pr_err("PROTO_INUSE_NR exhausted\n");
2497 		return;
2498 	}
2499 
2500 	set_bit(prot->inuse_idx, proto_inuse_idx);
2501 }
2502 
2503 static void release_proto_idx(struct proto *prot)
2504 {
2505 	if (prot->inuse_idx != PROTO_INUSE_NR - 1)
2506 		clear_bit(prot->inuse_idx, proto_inuse_idx);
2507 }
2508 #else
2509 static inline void assign_proto_idx(struct proto *prot)
2510 {
2511 }
2512 
2513 static inline void release_proto_idx(struct proto *prot)
2514 {
2515 }
2516 #endif
2517 
2518 int proto_register(struct proto *prot, int alloc_slab)
2519 {
2520 	if (alloc_slab) {
2521 		prot->slab = kmem_cache_create(prot->name, prot->obj_size, 0,
2522 					SLAB_HWCACHE_ALIGN | prot->slab_flags,
2523 					NULL);
2524 
2525 		if (prot->slab == NULL) {
2526 			pr_crit("%s: Can't create sock SLAB cache!\n",
2527 				prot->name);
2528 			goto out;
2529 		}
2530 
2531 		if (prot->rsk_prot != NULL) {
2532 			prot->rsk_prot->slab_name = kasprintf(GFP_KERNEL, "request_sock_%s", prot->name);
2533 			if (prot->rsk_prot->slab_name == NULL)
2534 				goto out_free_sock_slab;
2535 
2536 			prot->rsk_prot->slab = kmem_cache_create(prot->rsk_prot->slab_name,
2537 								 prot->rsk_prot->obj_size, 0,
2538 								 SLAB_HWCACHE_ALIGN, NULL);
2539 
2540 			if (prot->rsk_prot->slab == NULL) {
2541 				pr_crit("%s: Can't create request sock SLAB cache!\n",
2542 					prot->name);
2543 				goto out_free_request_sock_slab_name;
2544 			}
2545 		}
2546 
2547 		if (prot->twsk_prot != NULL) {
2548 			prot->twsk_prot->twsk_slab_name = kasprintf(GFP_KERNEL, "tw_sock_%s", prot->name);
2549 
2550 			if (prot->twsk_prot->twsk_slab_name == NULL)
2551 				goto out_free_request_sock_slab;
2552 
2553 			prot->twsk_prot->twsk_slab =
2554 				kmem_cache_create(prot->twsk_prot->twsk_slab_name,
2555 						  prot->twsk_prot->twsk_obj_size,
2556 						  0,
2557 						  SLAB_HWCACHE_ALIGN |
2558 							prot->slab_flags,
2559 						  NULL);
2560 			if (prot->twsk_prot->twsk_slab == NULL)
2561 				goto out_free_timewait_sock_slab_name;
2562 		}
2563 	}
2564 
2565 	mutex_lock(&proto_list_mutex);
2566 	list_add(&prot->node, &proto_list);
2567 	assign_proto_idx(prot);
2568 	mutex_unlock(&proto_list_mutex);
2569 	return 0;
2570 
2571 out_free_timewait_sock_slab_name:
2572 	kfree(prot->twsk_prot->twsk_slab_name);
2573 out_free_request_sock_slab:
2574 	if (prot->rsk_prot && prot->rsk_prot->slab) {
2575 		kmem_cache_destroy(prot->rsk_prot->slab);
2576 		prot->rsk_prot->slab = NULL;
2577 	}
2578 out_free_request_sock_slab_name:
2579 	if (prot->rsk_prot)
2580 		kfree(prot->rsk_prot->slab_name);
2581 out_free_sock_slab:
2582 	kmem_cache_destroy(prot->slab);
2583 	prot->slab = NULL;
2584 out:
2585 	return -ENOBUFS;
2586 }
2587 EXPORT_SYMBOL(proto_register);
2588 
2589 void proto_unregister(struct proto *prot)
2590 {
2591 	mutex_lock(&proto_list_mutex);
2592 	release_proto_idx(prot);
2593 	list_del(&prot->node);
2594 	mutex_unlock(&proto_list_mutex);
2595 
2596 	if (prot->slab != NULL) {
2597 		kmem_cache_destroy(prot->slab);
2598 		prot->slab = NULL;
2599 	}
2600 
2601 	if (prot->rsk_prot != NULL && prot->rsk_prot->slab != NULL) {
2602 		kmem_cache_destroy(prot->rsk_prot->slab);
2603 		kfree(prot->rsk_prot->slab_name);
2604 		prot->rsk_prot->slab = NULL;
2605 	}
2606 
2607 	if (prot->twsk_prot != NULL && prot->twsk_prot->twsk_slab != NULL) {
2608 		kmem_cache_destroy(prot->twsk_prot->twsk_slab);
2609 		kfree(prot->twsk_prot->twsk_slab_name);
2610 		prot->twsk_prot->twsk_slab = NULL;
2611 	}
2612 }
2613 EXPORT_SYMBOL(proto_unregister);
2614 
2615 #ifdef CONFIG_PROC_FS
2616 static void *proto_seq_start(struct seq_file *seq, loff_t *pos)
2617 	__acquires(proto_list_mutex)
2618 {
2619 	mutex_lock(&proto_list_mutex);
2620 	return seq_list_start_head(&proto_list, *pos);
2621 }
2622 
2623 static void *proto_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2624 {
2625 	return seq_list_next(v, &proto_list, pos);
2626 }
2627 
2628 static void proto_seq_stop(struct seq_file *seq, void *v)
2629 	__releases(proto_list_mutex)
2630 {
2631 	mutex_unlock(&proto_list_mutex);
2632 }
2633 
2634 static char proto_method_implemented(const void *method)
2635 {
2636 	return method == NULL ? 'n' : 'y';
2637 }
2638 static long sock_prot_memory_allocated(struct proto *proto)
2639 {
2640 	return proto->memory_allocated != NULL ? proto_memory_allocated(proto) : -1L;
2641 }
2642 
2643 static char *sock_prot_memory_pressure(struct proto *proto)
2644 {
2645 	return proto->memory_pressure != NULL ?
2646 	proto_memory_pressure(proto) ? "yes" : "no" : "NI";
2647 }
2648 
2649 static void proto_seq_printf(struct seq_file *seq, struct proto *proto)
2650 {
2651 
2652 	seq_printf(seq, "%-9s %4u %6d  %6ld   %-3s %6u   %-3s  %-10s "
2653 			"%2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c\n",
2654 		   proto->name,
2655 		   proto->obj_size,
2656 		   sock_prot_inuse_get(seq_file_net(seq), proto),
2657 		   sock_prot_memory_allocated(proto),
2658 		   sock_prot_memory_pressure(proto),
2659 		   proto->max_header,
2660 		   proto->slab == NULL ? "no" : "yes",
2661 		   module_name(proto->owner),
2662 		   proto_method_implemented(proto->close),
2663 		   proto_method_implemented(proto->connect),
2664 		   proto_method_implemented(proto->disconnect),
2665 		   proto_method_implemented(proto->accept),
2666 		   proto_method_implemented(proto->ioctl),
2667 		   proto_method_implemented(proto->init),
2668 		   proto_method_implemented(proto->destroy),
2669 		   proto_method_implemented(proto->shutdown),
2670 		   proto_method_implemented(proto->setsockopt),
2671 		   proto_method_implemented(proto->getsockopt),
2672 		   proto_method_implemented(proto->sendmsg),
2673 		   proto_method_implemented(proto->recvmsg),
2674 		   proto_method_implemented(proto->sendpage),
2675 		   proto_method_implemented(proto->bind),
2676 		   proto_method_implemented(proto->backlog_rcv),
2677 		   proto_method_implemented(proto->hash),
2678 		   proto_method_implemented(proto->unhash),
2679 		   proto_method_implemented(proto->get_port),
2680 		   proto_method_implemented(proto->enter_memory_pressure));
2681 }
2682 
2683 static int proto_seq_show(struct seq_file *seq, void *v)
2684 {
2685 	if (v == &proto_list)
2686 		seq_printf(seq, "%-9s %-4s %-8s %-6s %-5s %-7s %-4s %-10s %s",
2687 			   "protocol",
2688 			   "size",
2689 			   "sockets",
2690 			   "memory",
2691 			   "press",
2692 			   "maxhdr",
2693 			   "slab",
2694 			   "module",
2695 			   "cl co di ac io in de sh ss gs se re sp bi br ha uh gp em\n");
2696 	else
2697 		proto_seq_printf(seq, list_entry(v, struct proto, node));
2698 	return 0;
2699 }
2700 
2701 static const struct seq_operations proto_seq_ops = {
2702 	.start  = proto_seq_start,
2703 	.next   = proto_seq_next,
2704 	.stop   = proto_seq_stop,
2705 	.show   = proto_seq_show,
2706 };
2707 
2708 static int proto_seq_open(struct inode *inode, struct file *file)
2709 {
2710 	return seq_open_net(inode, file, &proto_seq_ops,
2711 			    sizeof(struct seq_net_private));
2712 }
2713 
2714 static const struct file_operations proto_seq_fops = {
2715 	.owner		= THIS_MODULE,
2716 	.open		= proto_seq_open,
2717 	.read		= seq_read,
2718 	.llseek		= seq_lseek,
2719 	.release	= seq_release_net,
2720 };
2721 
2722 static __net_init int proto_init_net(struct net *net)
2723 {
2724 	if (!proc_net_fops_create(net, "protocols", S_IRUGO, &proto_seq_fops))
2725 		return -ENOMEM;
2726 
2727 	return 0;
2728 }
2729 
2730 static __net_exit void proto_exit_net(struct net *net)
2731 {
2732 	proc_net_remove(net, "protocols");
2733 }
2734 
2735 
2736 static __net_initdata struct pernet_operations proto_net_ops = {
2737 	.init = proto_init_net,
2738 	.exit = proto_exit_net,
2739 };
2740 
2741 static int __init proto_init(void)
2742 {
2743 	return register_pernet_subsys(&proto_net_ops);
2744 }
2745 
2746 subsys_initcall(proto_init);
2747 
2748 #endif /* PROC_FS */
2749