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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 #include <linux/capability.h>
93 #include <linux/errno.h>
94 #include <linux/types.h>
95 #include <linux/socket.h>
96 #include <linux/in.h>
97 #include <linux/kernel.h>
98 #include <linux/module.h>
99 #include <linux/proc_fs.h>
100 #include <linux/seq_file.h>
101 #include <linux/sched.h>
102 #include <linux/timer.h>
103 #include <linux/string.h>
104 #include <linux/sockios.h>
105 #include <linux/net.h>
106 #include <linux/mm.h>
107 #include <linux/slab.h>
108 #include <linux/interrupt.h>
109 #include <linux/poll.h>
110 #include <linux/tcp.h>
111 #include <linux/init.h>
112 #include <linux/highmem.h>
113 
114 #include <asm/uaccess.h>
115 #include <asm/system.h>
116 
117 #include <linux/netdevice.h>
118 #include <net/protocol.h>
119 #include <linux/skbuff.h>
120 #include <net/net_namespace.h>
121 #include <net/request_sock.h>
122 #include <net/sock.h>
123 #include <net/xfrm.h>
124 #include <linux/ipsec.h>
125 
126 #include <linux/filter.h>
127 
128 #ifdef CONFIG_INET
129 #include <net/tcp.h>
130 #endif
131 
132 /*
133  * Each address family might have different locking rules, so we have
134  * one slock key per address family:
135  */
136 static struct lock_class_key af_family_keys[AF_MAX];
137 static struct lock_class_key af_family_slock_keys[AF_MAX];
138 
139 /*
140  * Make lock validator output more readable. (we pre-construct these
141  * strings build-time, so that runtime initialization of socket
142  * locks is fast):
143  */
144 static const char *af_family_key_strings[AF_MAX+1] = {
145   "sk_lock-AF_UNSPEC", "sk_lock-AF_UNIX"     , "sk_lock-AF_INET"     ,
146   "sk_lock-AF_AX25"  , "sk_lock-AF_IPX"      , "sk_lock-AF_APPLETALK",
147   "sk_lock-AF_NETROM", "sk_lock-AF_BRIDGE"   , "sk_lock-AF_ATMPVC"   ,
148   "sk_lock-AF_X25"   , "sk_lock-AF_INET6"    , "sk_lock-AF_ROSE"     ,
149   "sk_lock-AF_DECnet", "sk_lock-AF_NETBEUI"  , "sk_lock-AF_SECURITY" ,
150   "sk_lock-AF_KEY"   , "sk_lock-AF_NETLINK"  , "sk_lock-AF_PACKET"   ,
151   "sk_lock-AF_ASH"   , "sk_lock-AF_ECONET"   , "sk_lock-AF_ATMSVC"   ,
152   "sk_lock-21"       , "sk_lock-AF_SNA"      , "sk_lock-AF_IRDA"     ,
153   "sk_lock-AF_PPPOX" , "sk_lock-AF_WANPIPE"  , "sk_lock-AF_LLC"      ,
154   "sk_lock-27"       , "sk_lock-28"          , "sk_lock-AF_CAN"      ,
155   "sk_lock-AF_TIPC"  , "sk_lock-AF_BLUETOOTH", "sk_lock-IUCV"        ,
156   "sk_lock-AF_RXRPC" , "sk_lock-AF_ISDN"     , "sk_lock-AF_PHONET"   ,
157   "sk_lock-AF_MAX"
158 };
159 static const char *af_family_slock_key_strings[AF_MAX+1] = {
160   "slock-AF_UNSPEC", "slock-AF_UNIX"     , "slock-AF_INET"     ,
161   "slock-AF_AX25"  , "slock-AF_IPX"      , "slock-AF_APPLETALK",
162   "slock-AF_NETROM", "slock-AF_BRIDGE"   , "slock-AF_ATMPVC"   ,
163   "slock-AF_X25"   , "slock-AF_INET6"    , "slock-AF_ROSE"     ,
164   "slock-AF_DECnet", "slock-AF_NETBEUI"  , "slock-AF_SECURITY" ,
165   "slock-AF_KEY"   , "slock-AF_NETLINK"  , "slock-AF_PACKET"   ,
166   "slock-AF_ASH"   , "slock-AF_ECONET"   , "slock-AF_ATMSVC"   ,
167   "slock-21"       , "slock-AF_SNA"      , "slock-AF_IRDA"     ,
168   "slock-AF_PPPOX" , "slock-AF_WANPIPE"  , "slock-AF_LLC"      ,
169   "slock-27"       , "slock-28"          , "slock-AF_CAN"      ,
170   "slock-AF_TIPC"  , "slock-AF_BLUETOOTH", "slock-AF_IUCV"     ,
171   "slock-AF_RXRPC" , "slock-AF_ISDN"     , "slock-AF_PHONET"   ,
172   "slock-AF_MAX"
173 };
174 static const char *af_family_clock_key_strings[AF_MAX+1] = {
175   "clock-AF_UNSPEC", "clock-AF_UNIX"     , "clock-AF_INET"     ,
176   "clock-AF_AX25"  , "clock-AF_IPX"      , "clock-AF_APPLETALK",
177   "clock-AF_NETROM", "clock-AF_BRIDGE"   , "clock-AF_ATMPVC"   ,
178   "clock-AF_X25"   , "clock-AF_INET6"    , "clock-AF_ROSE"     ,
179   "clock-AF_DECnet", "clock-AF_NETBEUI"  , "clock-AF_SECURITY" ,
180   "clock-AF_KEY"   , "clock-AF_NETLINK"  , "clock-AF_PACKET"   ,
181   "clock-AF_ASH"   , "clock-AF_ECONET"   , "clock-AF_ATMSVC"   ,
182   "clock-21"       , "clock-AF_SNA"      , "clock-AF_IRDA"     ,
183   "clock-AF_PPPOX" , "clock-AF_WANPIPE"  , "clock-AF_LLC"      ,
184   "clock-27"       , "clock-28"          , "clock-AF_CAN"      ,
185   "clock-AF_TIPC"  , "clock-AF_BLUETOOTH", "clock-AF_IUCV"     ,
186   "clock-AF_RXRPC" , "clock-AF_ISDN"     , "clock-AF_PHONET"   ,
187   "clock-AF_MAX"
188 };
189 
190 /*
191  * sk_callback_lock locking rules are per-address-family,
192  * so split the lock classes by using a per-AF key:
193  */
194 static struct lock_class_key af_callback_keys[AF_MAX];
195 
196 /* Take into consideration the size of the struct sk_buff overhead in the
197  * determination of these values, since that is non-constant across
198  * platforms.  This makes socket queueing behavior and performance
199  * not depend upon such differences.
200  */
201 #define _SK_MEM_PACKETS		256
202 #define _SK_MEM_OVERHEAD	(sizeof(struct sk_buff) + 256)
203 #define SK_WMEM_MAX		(_SK_MEM_OVERHEAD * _SK_MEM_PACKETS)
204 #define SK_RMEM_MAX		(_SK_MEM_OVERHEAD * _SK_MEM_PACKETS)
205 
206 /* Run time adjustable parameters. */
207 __u32 sysctl_wmem_max __read_mostly = SK_WMEM_MAX;
208 __u32 sysctl_rmem_max __read_mostly = SK_RMEM_MAX;
209 __u32 sysctl_wmem_default __read_mostly = SK_WMEM_MAX;
210 __u32 sysctl_rmem_default __read_mostly = SK_RMEM_MAX;
211 
212 /* Maximal space eaten by iovec or ancilliary data plus some space */
213 int sysctl_optmem_max __read_mostly = sizeof(unsigned long)*(2*UIO_MAXIOV+512);
214 
sock_set_timeout(long * timeo_p,char __user * optval,int optlen)215 static int sock_set_timeout(long *timeo_p, char __user *optval, int optlen)
216 {
217 	struct timeval tv;
218 
219 	if (optlen < sizeof(tv))
220 		return -EINVAL;
221 	if (copy_from_user(&tv, optval, sizeof(tv)))
222 		return -EFAULT;
223 	if (tv.tv_usec < 0 || tv.tv_usec >= USEC_PER_SEC)
224 		return -EDOM;
225 
226 	if (tv.tv_sec < 0) {
227 		static int warned __read_mostly;
228 
229 		*timeo_p = 0;
230 		if (warned < 10 && net_ratelimit()) {
231 			warned++;
232 			printk(KERN_INFO "sock_set_timeout: `%s' (pid %d) "
233 			       "tries to set negative timeout\n",
234 				current->comm, task_pid_nr(current));
235 		}
236 		return 0;
237 	}
238 	*timeo_p = MAX_SCHEDULE_TIMEOUT;
239 	if (tv.tv_sec == 0 && tv.tv_usec == 0)
240 		return 0;
241 	if (tv.tv_sec < (MAX_SCHEDULE_TIMEOUT/HZ - 1))
242 		*timeo_p = tv.tv_sec*HZ + (tv.tv_usec+(1000000/HZ-1))/(1000000/HZ);
243 	return 0;
244 }
245 
sock_warn_obsolete_bsdism(const char * name)246 static void sock_warn_obsolete_bsdism(const char *name)
247 {
248 	static int warned;
249 	static char warncomm[TASK_COMM_LEN];
250 	if (strcmp(warncomm, current->comm) && warned < 5) {
251 		strcpy(warncomm,  current->comm);
252 		printk(KERN_WARNING "process `%s' is using obsolete "
253 		       "%s SO_BSDCOMPAT\n", warncomm, name);
254 		warned++;
255 	}
256 }
257 
sock_disable_timestamp(struct sock * sk)258 static void sock_disable_timestamp(struct sock *sk)
259 {
260 	if (sock_flag(sk, SOCK_TIMESTAMP)) {
261 		sock_reset_flag(sk, SOCK_TIMESTAMP);
262 		net_disable_timestamp();
263 	}
264 }
265 
266 
sock_queue_rcv_skb(struct sock * sk,struct sk_buff * skb)267 int sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
268 {
269 	int err = 0;
270 	int skb_len;
271 
272 	/* Cast sk->rcvbuf to unsigned... It's pointless, but reduces
273 	   number of warnings when compiling with -W --ANK
274 	 */
275 	if (atomic_read(&sk->sk_rmem_alloc) + skb->truesize >=
276 	    (unsigned)sk->sk_rcvbuf) {
277 		err = -ENOMEM;
278 		goto out;
279 	}
280 
281 	err = sk_filter(sk, skb);
282 	if (err)
283 		goto out;
284 
285 	if (!sk_rmem_schedule(sk, skb->truesize)) {
286 		err = -ENOBUFS;
287 		goto out;
288 	}
289 
290 	skb->dev = NULL;
291 	skb_set_owner_r(skb, sk);
292 
293 	/* Cache the SKB length before we tack it onto the receive
294 	 * queue.  Once it is added it no longer belongs to us and
295 	 * may be freed by other threads of control pulling packets
296 	 * from the queue.
297 	 */
298 	skb_len = skb->len;
299 
300 	skb_queue_tail(&sk->sk_receive_queue, skb);
301 
302 	if (!sock_flag(sk, SOCK_DEAD))
303 		sk->sk_data_ready(sk, skb_len);
304 out:
305 	return err;
306 }
307 EXPORT_SYMBOL(sock_queue_rcv_skb);
308 
sk_receive_skb(struct sock * sk,struct sk_buff * skb,const int nested)309 int sk_receive_skb(struct sock *sk, struct sk_buff *skb, const int nested)
310 {
311 	int rc = NET_RX_SUCCESS;
312 
313 	if (sk_filter(sk, skb))
314 		goto discard_and_relse;
315 
316 	skb->dev = NULL;
317 
318 	if (nested)
319 		bh_lock_sock_nested(sk);
320 	else
321 		bh_lock_sock(sk);
322 	if (!sock_owned_by_user(sk)) {
323 		/*
324 		 * trylock + unlock semantics:
325 		 */
326 		mutex_acquire(&sk->sk_lock.dep_map, 0, 1, _RET_IP_);
327 
328 		rc = sk_backlog_rcv(sk, skb);
329 
330 		mutex_release(&sk->sk_lock.dep_map, 1, _RET_IP_);
331 	} else
332 		sk_add_backlog(sk, skb);
333 	bh_unlock_sock(sk);
334 out:
335 	sock_put(sk);
336 	return rc;
337 discard_and_relse:
338 	kfree_skb(skb);
339 	goto out;
340 }
341 EXPORT_SYMBOL(sk_receive_skb);
342 
__sk_dst_check(struct sock * sk,u32 cookie)343 struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie)
344 {
345 	struct dst_entry *dst = sk->sk_dst_cache;
346 
347 	if (dst && dst->obsolete && dst->ops->check(dst, cookie) == NULL) {
348 		sk->sk_dst_cache = NULL;
349 		dst_release(dst);
350 		return NULL;
351 	}
352 
353 	return dst;
354 }
355 EXPORT_SYMBOL(__sk_dst_check);
356 
sk_dst_check(struct sock * sk,u32 cookie)357 struct dst_entry *sk_dst_check(struct sock *sk, u32 cookie)
358 {
359 	struct dst_entry *dst = sk_dst_get(sk);
360 
361 	if (dst && dst->obsolete && dst->ops->check(dst, cookie) == NULL) {
362 		sk_dst_reset(sk);
363 		dst_release(dst);
364 		return NULL;
365 	}
366 
367 	return dst;
368 }
369 EXPORT_SYMBOL(sk_dst_check);
370 
sock_bindtodevice(struct sock * sk,char __user * optval,int optlen)371 static int sock_bindtodevice(struct sock *sk, char __user *optval, int optlen)
372 {
373 	int ret = -ENOPROTOOPT;
374 #ifdef CONFIG_NETDEVICES
375 	struct net *net = sock_net(sk);
376 	char devname[IFNAMSIZ];
377 	int index;
378 
379 	/* Sorry... */
380 	ret = -EPERM;
381 	if (!capable(CAP_NET_RAW))
382 		goto out;
383 
384 	ret = -EINVAL;
385 	if (optlen < 0)
386 		goto out;
387 
388 	/* Bind this socket to a particular device like "eth0",
389 	 * as specified in the passed interface name. If the
390 	 * name is "" or the option length is zero the socket
391 	 * is not bound.
392 	 */
393 	if (optlen > IFNAMSIZ - 1)
394 		optlen = IFNAMSIZ - 1;
395 	memset(devname, 0, sizeof(devname));
396 
397 	ret = -EFAULT;
398 	if (copy_from_user(devname, optval, optlen))
399 		goto out;
400 
401 	if (devname[0] == '\0') {
402 		index = 0;
403 	} else {
404 		struct net_device *dev = dev_get_by_name(net, devname);
405 
406 		ret = -ENODEV;
407 		if (!dev)
408 			goto out;
409 
410 		index = dev->ifindex;
411 		dev_put(dev);
412 	}
413 
414 	lock_sock(sk);
415 	sk->sk_bound_dev_if = index;
416 	sk_dst_reset(sk);
417 	release_sock(sk);
418 
419 	ret = 0;
420 
421 out:
422 #endif
423 
424 	return ret;
425 }
426 
sock_valbool_flag(struct sock * sk,int bit,int valbool)427 static inline void sock_valbool_flag(struct sock *sk, int bit, int valbool)
428 {
429 	if (valbool)
430 		sock_set_flag(sk, bit);
431 	else
432 		sock_reset_flag(sk, bit);
433 }
434 
435 /*
436  *	This is meant for all protocols to use and covers goings on
437  *	at the socket level. Everything here is generic.
438  */
439 
sock_setsockopt(struct socket * sock,int level,int optname,char __user * optval,int optlen)440 int sock_setsockopt(struct socket *sock, int level, int optname,
441 		    char __user *optval, int optlen)
442 {
443 	struct sock *sk=sock->sk;
444 	int val;
445 	int valbool;
446 	struct linger ling;
447 	int ret = 0;
448 
449 	/*
450 	 *	Options without arguments
451 	 */
452 
453 	if (optname == SO_BINDTODEVICE)
454 		return sock_bindtodevice(sk, optval, optlen);
455 
456 	if (optlen < sizeof(int))
457 		return -EINVAL;
458 
459 	if (get_user(val, (int __user *)optval))
460 		return -EFAULT;
461 
462 	valbool = val?1:0;
463 
464 	lock_sock(sk);
465 
466 	switch(optname) {
467 	case SO_DEBUG:
468 		if (val && !capable(CAP_NET_ADMIN)) {
469 			ret = -EACCES;
470 		} else
471 			sock_valbool_flag(sk, SOCK_DBG, valbool);
472 		break;
473 	case SO_REUSEADDR:
474 		sk->sk_reuse = valbool;
475 		break;
476 	case SO_TYPE:
477 	case SO_ERROR:
478 		ret = -ENOPROTOOPT;
479 		break;
480 	case SO_DONTROUTE:
481 		sock_valbool_flag(sk, SOCK_LOCALROUTE, valbool);
482 		break;
483 	case SO_BROADCAST:
484 		sock_valbool_flag(sk, SOCK_BROADCAST, valbool);
485 		break;
486 	case SO_SNDBUF:
487 		/* Don't error on this BSD doesn't and if you think
488 		   about it this is right. Otherwise apps have to
489 		   play 'guess the biggest size' games. RCVBUF/SNDBUF
490 		   are treated in BSD as hints */
491 
492 		if (val > sysctl_wmem_max)
493 			val = sysctl_wmem_max;
494 set_sndbuf:
495 		sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
496 		if ((val * 2) < SOCK_MIN_SNDBUF)
497 			sk->sk_sndbuf = SOCK_MIN_SNDBUF;
498 		else
499 			sk->sk_sndbuf = val * 2;
500 
501 		/*
502 		 *	Wake up sending tasks if we
503 		 *	upped the value.
504 		 */
505 		sk->sk_write_space(sk);
506 		break;
507 
508 	case SO_SNDBUFFORCE:
509 		if (!capable(CAP_NET_ADMIN)) {
510 			ret = -EPERM;
511 			break;
512 		}
513 		goto set_sndbuf;
514 
515 	case SO_RCVBUF:
516 		/* Don't error on this BSD doesn't and if you think
517 		   about it this is right. Otherwise apps have to
518 		   play 'guess the biggest size' games. RCVBUF/SNDBUF
519 		   are treated in BSD as hints */
520 
521 		if (val > sysctl_rmem_max)
522 			val = sysctl_rmem_max;
523 set_rcvbuf:
524 		sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
525 		/*
526 		 * We double it on the way in to account for
527 		 * "struct sk_buff" etc. overhead.   Applications
528 		 * assume that the SO_RCVBUF setting they make will
529 		 * allow that much actual data to be received on that
530 		 * socket.
531 		 *
532 		 * Applications are unaware that "struct sk_buff" and
533 		 * other overheads allocate from the receive buffer
534 		 * during socket buffer allocation.
535 		 *
536 		 * And after considering the possible alternatives,
537 		 * returning the value we actually used in getsockopt
538 		 * is the most desirable behavior.
539 		 */
540 		if ((val * 2) < SOCK_MIN_RCVBUF)
541 			sk->sk_rcvbuf = SOCK_MIN_RCVBUF;
542 		else
543 			sk->sk_rcvbuf = val * 2;
544 		break;
545 
546 	case SO_RCVBUFFORCE:
547 		if (!capable(CAP_NET_ADMIN)) {
548 			ret = -EPERM;
549 			break;
550 		}
551 		goto set_rcvbuf;
552 
553 	case SO_KEEPALIVE:
554 #ifdef CONFIG_INET
555 		if (sk->sk_protocol == IPPROTO_TCP)
556 			tcp_set_keepalive(sk, valbool);
557 #endif
558 		sock_valbool_flag(sk, SOCK_KEEPOPEN, valbool);
559 		break;
560 
561 	case SO_OOBINLINE:
562 		sock_valbool_flag(sk, SOCK_URGINLINE, valbool);
563 		break;
564 
565 	case SO_NO_CHECK:
566 		sk->sk_no_check = valbool;
567 		break;
568 
569 	case SO_PRIORITY:
570 		if ((val >= 0 && val <= 6) || capable(CAP_NET_ADMIN))
571 			sk->sk_priority = val;
572 		else
573 			ret = -EPERM;
574 		break;
575 
576 	case SO_LINGER:
577 		if (optlen < sizeof(ling)) {
578 			ret = -EINVAL;	/* 1003.1g */
579 			break;
580 		}
581 		if (copy_from_user(&ling,optval,sizeof(ling))) {
582 			ret = -EFAULT;
583 			break;
584 		}
585 		if (!ling.l_onoff)
586 			sock_reset_flag(sk, SOCK_LINGER);
587 		else {
588 #if (BITS_PER_LONG == 32)
589 			if ((unsigned int)ling.l_linger >= MAX_SCHEDULE_TIMEOUT/HZ)
590 				sk->sk_lingertime = MAX_SCHEDULE_TIMEOUT;
591 			else
592 #endif
593 				sk->sk_lingertime = (unsigned int)ling.l_linger * HZ;
594 			sock_set_flag(sk, SOCK_LINGER);
595 		}
596 		break;
597 
598 	case SO_BSDCOMPAT:
599 		sock_warn_obsolete_bsdism("setsockopt");
600 		break;
601 
602 	case SO_PASSCRED:
603 		if (valbool)
604 			set_bit(SOCK_PASSCRED, &sock->flags);
605 		else
606 			clear_bit(SOCK_PASSCRED, &sock->flags);
607 		break;
608 
609 	case SO_TIMESTAMP:
610 	case SO_TIMESTAMPNS:
611 		if (valbool)  {
612 			if (optname == SO_TIMESTAMP)
613 				sock_reset_flag(sk, SOCK_RCVTSTAMPNS);
614 			else
615 				sock_set_flag(sk, SOCK_RCVTSTAMPNS);
616 			sock_set_flag(sk, SOCK_RCVTSTAMP);
617 			sock_enable_timestamp(sk);
618 		} else {
619 			sock_reset_flag(sk, SOCK_RCVTSTAMP);
620 			sock_reset_flag(sk, SOCK_RCVTSTAMPNS);
621 		}
622 		break;
623 
624 	case SO_RCVLOWAT:
625 		if (val < 0)
626 			val = INT_MAX;
627 		sk->sk_rcvlowat = val ? : 1;
628 		break;
629 
630 	case SO_RCVTIMEO:
631 		ret = sock_set_timeout(&sk->sk_rcvtimeo, optval, optlen);
632 		break;
633 
634 	case SO_SNDTIMEO:
635 		ret = sock_set_timeout(&sk->sk_sndtimeo, optval, optlen);
636 		break;
637 
638 	case SO_ATTACH_FILTER:
639 		ret = -EINVAL;
640 		if (optlen == sizeof(struct sock_fprog)) {
641 			struct sock_fprog fprog;
642 
643 			ret = -EFAULT;
644 			if (copy_from_user(&fprog, optval, sizeof(fprog)))
645 				break;
646 
647 			ret = sk_attach_filter(&fprog, sk);
648 		}
649 		break;
650 
651 	case SO_DETACH_FILTER:
652 		ret = sk_detach_filter(sk);
653 		break;
654 
655 	case SO_PASSSEC:
656 		if (valbool)
657 			set_bit(SOCK_PASSSEC, &sock->flags);
658 		else
659 			clear_bit(SOCK_PASSSEC, &sock->flags);
660 		break;
661 	case SO_MARK:
662 		if (!capable(CAP_NET_ADMIN))
663 			ret = -EPERM;
664 		else {
665 			sk->sk_mark = val;
666 		}
667 		break;
668 
669 		/* We implement the SO_SNDLOWAT etc to
670 		   not be settable (1003.1g 5.3) */
671 	default:
672 		ret = -ENOPROTOOPT;
673 		break;
674 	}
675 	release_sock(sk);
676 	return ret;
677 }
678 
679 
sock_getsockopt(struct socket * sock,int level,int optname,char __user * optval,int __user * optlen)680 int sock_getsockopt(struct socket *sock, int level, int optname,
681 		    char __user *optval, int __user *optlen)
682 {
683 	struct sock *sk = sock->sk;
684 
685 	union {
686 		int val;
687 		struct linger ling;
688 		struct timeval tm;
689 	} v;
690 
691 	unsigned int lv = sizeof(int);
692 	int len;
693 
694 	if (get_user(len, optlen))
695 		return -EFAULT;
696 	if (len < 0)
697 		return -EINVAL;
698 
699 	memset(&v, 0, sizeof(v));
700 
701 	switch(optname) {
702 	case SO_DEBUG:
703 		v.val = sock_flag(sk, SOCK_DBG);
704 		break;
705 
706 	case SO_DONTROUTE:
707 		v.val = sock_flag(sk, SOCK_LOCALROUTE);
708 		break;
709 
710 	case SO_BROADCAST:
711 		v.val = !!sock_flag(sk, SOCK_BROADCAST);
712 		break;
713 
714 	case SO_SNDBUF:
715 		v.val = sk->sk_sndbuf;
716 		break;
717 
718 	case SO_RCVBUF:
719 		v.val = sk->sk_rcvbuf;
720 		break;
721 
722 	case SO_REUSEADDR:
723 		v.val = sk->sk_reuse;
724 		break;
725 
726 	case SO_KEEPALIVE:
727 		v.val = !!sock_flag(sk, SOCK_KEEPOPEN);
728 		break;
729 
730 	case SO_TYPE:
731 		v.val = sk->sk_type;
732 		break;
733 
734 	case SO_ERROR:
735 		v.val = -sock_error(sk);
736 		if (v.val==0)
737 			v.val = xchg(&sk->sk_err_soft, 0);
738 		break;
739 
740 	case SO_OOBINLINE:
741 		v.val = !!sock_flag(sk, SOCK_URGINLINE);
742 		break;
743 
744 	case SO_NO_CHECK:
745 		v.val = sk->sk_no_check;
746 		break;
747 
748 	case SO_PRIORITY:
749 		v.val = sk->sk_priority;
750 		break;
751 
752 	case SO_LINGER:
753 		lv		= sizeof(v.ling);
754 		v.ling.l_onoff	= !!sock_flag(sk, SOCK_LINGER);
755 		v.ling.l_linger	= sk->sk_lingertime / HZ;
756 		break;
757 
758 	case SO_BSDCOMPAT:
759 		sock_warn_obsolete_bsdism("getsockopt");
760 		break;
761 
762 	case SO_TIMESTAMP:
763 		v.val = sock_flag(sk, SOCK_RCVTSTAMP) &&
764 				!sock_flag(sk, SOCK_RCVTSTAMPNS);
765 		break;
766 
767 	case SO_TIMESTAMPNS:
768 		v.val = sock_flag(sk, SOCK_RCVTSTAMPNS);
769 		break;
770 
771 	case SO_RCVTIMEO:
772 		lv=sizeof(struct timeval);
773 		if (sk->sk_rcvtimeo == MAX_SCHEDULE_TIMEOUT) {
774 			v.tm.tv_sec = 0;
775 			v.tm.tv_usec = 0;
776 		} else {
777 			v.tm.tv_sec = sk->sk_rcvtimeo / HZ;
778 			v.tm.tv_usec = ((sk->sk_rcvtimeo % HZ) * 1000000) / HZ;
779 		}
780 		break;
781 
782 	case SO_SNDTIMEO:
783 		lv=sizeof(struct timeval);
784 		if (sk->sk_sndtimeo == MAX_SCHEDULE_TIMEOUT) {
785 			v.tm.tv_sec = 0;
786 			v.tm.tv_usec = 0;
787 		} else {
788 			v.tm.tv_sec = sk->sk_sndtimeo / HZ;
789 			v.tm.tv_usec = ((sk->sk_sndtimeo % HZ) * 1000000) / HZ;
790 		}
791 		break;
792 
793 	case SO_RCVLOWAT:
794 		v.val = sk->sk_rcvlowat;
795 		break;
796 
797 	case SO_SNDLOWAT:
798 		v.val=1;
799 		break;
800 
801 	case SO_PASSCRED:
802 		v.val = test_bit(SOCK_PASSCRED, &sock->flags) ? 1 : 0;
803 		break;
804 
805 	case SO_PEERCRED:
806 		if (len > sizeof(sk->sk_peercred))
807 			len = sizeof(sk->sk_peercred);
808 		if (copy_to_user(optval, &sk->sk_peercred, len))
809 			return -EFAULT;
810 		goto lenout;
811 
812 	case SO_PEERNAME:
813 	{
814 		char address[128];
815 
816 		if (sock->ops->getname(sock, (struct sockaddr *)address, &lv, 2))
817 			return -ENOTCONN;
818 		if (lv < len)
819 			return -EINVAL;
820 		if (copy_to_user(optval, address, len))
821 			return -EFAULT;
822 		goto lenout;
823 	}
824 
825 	/* Dubious BSD thing... Probably nobody even uses it, but
826 	 * the UNIX standard wants it for whatever reason... -DaveM
827 	 */
828 	case SO_ACCEPTCONN:
829 		v.val = sk->sk_state == TCP_LISTEN;
830 		break;
831 
832 	case SO_PASSSEC:
833 		v.val = test_bit(SOCK_PASSSEC, &sock->flags) ? 1 : 0;
834 		break;
835 
836 	case SO_PEERSEC:
837 		return security_socket_getpeersec_stream(sock, optval, optlen, len);
838 
839 	case SO_MARK:
840 		v.val = sk->sk_mark;
841 		break;
842 
843 	default:
844 		return -ENOPROTOOPT;
845 	}
846 
847 	if (len > lv)
848 		len = lv;
849 	if (copy_to_user(optval, &v, len))
850 		return -EFAULT;
851 lenout:
852 	if (put_user(len, optlen))
853 		return -EFAULT;
854 	return 0;
855 }
856 
857 /*
858  * Initialize an sk_lock.
859  *
860  * (We also register the sk_lock with the lock validator.)
861  */
sock_lock_init(struct sock * sk)862 static inline void sock_lock_init(struct sock *sk)
863 {
864 	sock_lock_init_class_and_name(sk,
865 			af_family_slock_key_strings[sk->sk_family],
866 			af_family_slock_keys + sk->sk_family,
867 			af_family_key_strings[sk->sk_family],
868 			af_family_keys + sk->sk_family);
869 }
870 
sock_copy(struct sock * nsk,const struct sock * osk)871 static void sock_copy(struct sock *nsk, const struct sock *osk)
872 {
873 #ifdef CONFIG_SECURITY_NETWORK
874 	void *sptr = nsk->sk_security;
875 #endif
876 
877 	memcpy(nsk, osk, osk->sk_prot->obj_size);
878 #ifdef CONFIG_SECURITY_NETWORK
879 	nsk->sk_security = sptr;
880 	security_sk_clone(osk, nsk);
881 #endif
882 }
883 
sk_prot_alloc(struct proto * prot,gfp_t priority,int family)884 static struct sock *sk_prot_alloc(struct proto *prot, gfp_t priority,
885 		int family)
886 {
887 	struct sock *sk;
888 	struct kmem_cache *slab;
889 
890 	slab = prot->slab;
891 	if (slab != NULL)
892 		sk = kmem_cache_alloc(slab, priority);
893 	else
894 		sk = kmalloc(prot->obj_size, priority);
895 
896 	if (sk != NULL) {
897 		if (security_sk_alloc(sk, family, priority))
898 			goto out_free;
899 
900 		if (!try_module_get(prot->owner))
901 			goto out_free_sec;
902 	}
903 
904 	return sk;
905 
906 out_free_sec:
907 	security_sk_free(sk);
908 out_free:
909 	if (slab != NULL)
910 		kmem_cache_free(slab, sk);
911 	else
912 		kfree(sk);
913 	return NULL;
914 }
915 
sk_prot_free(struct proto * prot,struct sock * sk)916 static void sk_prot_free(struct proto *prot, struct sock *sk)
917 {
918 	struct kmem_cache *slab;
919 	struct module *owner;
920 
921 	owner = prot->owner;
922 	slab = prot->slab;
923 
924 	security_sk_free(sk);
925 	if (slab != NULL)
926 		kmem_cache_free(slab, sk);
927 	else
928 		kfree(sk);
929 	module_put(owner);
930 }
931 
932 /**
933  *	sk_alloc - All socket objects are allocated here
934  *	@net: the applicable net namespace
935  *	@family: protocol family
936  *	@priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
937  *	@prot: struct proto associated with this new sock instance
938  */
sk_alloc(struct net * net,int family,gfp_t priority,struct proto * prot)939 struct sock *sk_alloc(struct net *net, int family, gfp_t priority,
940 		      struct proto *prot)
941 {
942 	struct sock *sk;
943 
944 	sk = sk_prot_alloc(prot, priority | __GFP_ZERO, family);
945 	if (sk) {
946 		sk->sk_family = family;
947 		/*
948 		 * See comment in struct sock definition to understand
949 		 * why we need sk_prot_creator -acme
950 		 */
951 		sk->sk_prot = sk->sk_prot_creator = prot;
952 		sock_lock_init(sk);
953 		sock_net_set(sk, get_net(net));
954 	}
955 
956 	return sk;
957 }
958 
sk_free(struct sock * sk)959 void sk_free(struct sock *sk)
960 {
961 	struct sk_filter *filter;
962 
963 	if (sk->sk_destruct)
964 		sk->sk_destruct(sk);
965 
966 	filter = rcu_dereference(sk->sk_filter);
967 	if (filter) {
968 		sk_filter_uncharge(sk, filter);
969 		rcu_assign_pointer(sk->sk_filter, NULL);
970 	}
971 
972 	sock_disable_timestamp(sk);
973 
974 	if (atomic_read(&sk->sk_omem_alloc))
975 		printk(KERN_DEBUG "%s: optmem leakage (%d bytes) detected.\n",
976 		       __func__, atomic_read(&sk->sk_omem_alloc));
977 
978 	put_net(sock_net(sk));
979 	sk_prot_free(sk->sk_prot_creator, sk);
980 }
981 
982 /*
983  * Last sock_put should drop referrence to sk->sk_net. It has already
984  * been dropped in sk_change_net. Taking referrence to stopping namespace
985  * is not an option.
986  * Take referrence to a socket to remove it from hash _alive_ and after that
987  * destroy it in the context of init_net.
988  */
sk_release_kernel(struct sock * sk)989 void sk_release_kernel(struct sock *sk)
990 {
991 	if (sk == NULL || sk->sk_socket == NULL)
992 		return;
993 
994 	sock_hold(sk);
995 	sock_release(sk->sk_socket);
996 	release_net(sock_net(sk));
997 	sock_net_set(sk, get_net(&init_net));
998 	sock_put(sk);
999 }
1000 EXPORT_SYMBOL(sk_release_kernel);
1001 
sk_clone(const struct sock * sk,const gfp_t priority)1002 struct sock *sk_clone(const struct sock *sk, const gfp_t priority)
1003 {
1004 	struct sock *newsk;
1005 
1006 	newsk = sk_prot_alloc(sk->sk_prot, priority, sk->sk_family);
1007 	if (newsk != NULL) {
1008 		struct sk_filter *filter;
1009 
1010 		sock_copy(newsk, sk);
1011 
1012 		/* SANITY */
1013 		get_net(sock_net(newsk));
1014 		sk_node_init(&newsk->sk_node);
1015 		sock_lock_init(newsk);
1016 		bh_lock_sock(newsk);
1017 		newsk->sk_backlog.head	= newsk->sk_backlog.tail = NULL;
1018 
1019 		atomic_set(&newsk->sk_rmem_alloc, 0);
1020 		atomic_set(&newsk->sk_wmem_alloc, 0);
1021 		atomic_set(&newsk->sk_omem_alloc, 0);
1022 		skb_queue_head_init(&newsk->sk_receive_queue);
1023 		skb_queue_head_init(&newsk->sk_write_queue);
1024 #ifdef CONFIG_NET_DMA
1025 		skb_queue_head_init(&newsk->sk_async_wait_queue);
1026 #endif
1027 
1028 		rwlock_init(&newsk->sk_dst_lock);
1029 		rwlock_init(&newsk->sk_callback_lock);
1030 		lockdep_set_class_and_name(&newsk->sk_callback_lock,
1031 				af_callback_keys + newsk->sk_family,
1032 				af_family_clock_key_strings[newsk->sk_family]);
1033 
1034 		newsk->sk_dst_cache	= NULL;
1035 		newsk->sk_wmem_queued	= 0;
1036 		newsk->sk_forward_alloc = 0;
1037 		newsk->sk_send_head	= NULL;
1038 		newsk->sk_userlocks	= sk->sk_userlocks & ~SOCK_BINDPORT_LOCK;
1039 
1040 		sock_reset_flag(newsk, SOCK_DONE);
1041 		skb_queue_head_init(&newsk->sk_error_queue);
1042 
1043 		filter = newsk->sk_filter;
1044 		if (filter != NULL)
1045 			sk_filter_charge(newsk, filter);
1046 
1047 		if (unlikely(xfrm_sk_clone_policy(newsk))) {
1048 			/* It is still raw copy of parent, so invalidate
1049 			 * destructor and make plain sk_free() */
1050 			newsk->sk_destruct = NULL;
1051 			sk_free(newsk);
1052 			newsk = NULL;
1053 			goto out;
1054 		}
1055 
1056 		newsk->sk_err	   = 0;
1057 		newsk->sk_priority = 0;
1058 		atomic_set(&newsk->sk_refcnt, 2);
1059 
1060 		/*
1061 		 * Increment the counter in the same struct proto as the master
1062 		 * sock (sk_refcnt_debug_inc uses newsk->sk_prot->socks, that
1063 		 * is the same as sk->sk_prot->socks, as this field was copied
1064 		 * with memcpy).
1065 		 *
1066 		 * This _changes_ the previous behaviour, where
1067 		 * tcp_create_openreq_child always was incrementing the
1068 		 * equivalent to tcp_prot->socks (inet_sock_nr), so this have
1069 		 * to be taken into account in all callers. -acme
1070 		 */
1071 		sk_refcnt_debug_inc(newsk);
1072 		sk_set_socket(newsk, NULL);
1073 		newsk->sk_sleep	 = NULL;
1074 
1075 		if (newsk->sk_prot->sockets_allocated)
1076 			percpu_counter_inc(newsk->sk_prot->sockets_allocated);
1077 	}
1078 out:
1079 	return newsk;
1080 }
1081 
1082 EXPORT_SYMBOL_GPL(sk_clone);
1083 
sk_setup_caps(struct sock * sk,struct dst_entry * dst)1084 void sk_setup_caps(struct sock *sk, struct dst_entry *dst)
1085 {
1086 	__sk_dst_set(sk, dst);
1087 	sk->sk_route_caps = dst->dev->features;
1088 	if (sk->sk_route_caps & NETIF_F_GSO)
1089 		sk->sk_route_caps |= NETIF_F_GSO_SOFTWARE;
1090 	if (sk_can_gso(sk)) {
1091 		if (dst->header_len) {
1092 			sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
1093 		} else {
1094 			sk->sk_route_caps |= NETIF_F_SG | NETIF_F_HW_CSUM;
1095 			sk->sk_gso_max_size = dst->dev->gso_max_size;
1096 		}
1097 	}
1098 }
1099 EXPORT_SYMBOL_GPL(sk_setup_caps);
1100 
sk_init(void)1101 void __init sk_init(void)
1102 {
1103 	if (num_physpages <= 4096) {
1104 		sysctl_wmem_max = 32767;
1105 		sysctl_rmem_max = 32767;
1106 		sysctl_wmem_default = 32767;
1107 		sysctl_rmem_default = 32767;
1108 	} else if (num_physpages >= 131072) {
1109 		sysctl_wmem_max = 131071;
1110 		sysctl_rmem_max = 131071;
1111 	}
1112 }
1113 
1114 /*
1115  *	Simple resource managers for sockets.
1116  */
1117 
1118 
1119 /*
1120  * Write buffer destructor automatically called from kfree_skb.
1121  */
sock_wfree(struct sk_buff * skb)1122 void sock_wfree(struct sk_buff *skb)
1123 {
1124 	struct sock *sk = skb->sk;
1125 
1126 	/* In case it might be waiting for more memory. */
1127 	atomic_sub(skb->truesize, &sk->sk_wmem_alloc);
1128 	if (!sock_flag(sk, SOCK_USE_WRITE_QUEUE))
1129 		sk->sk_write_space(sk);
1130 	sock_put(sk);
1131 }
1132 
1133 /*
1134  * Read buffer destructor automatically called from kfree_skb.
1135  */
sock_rfree(struct sk_buff * skb)1136 void sock_rfree(struct sk_buff *skb)
1137 {
1138 	struct sock *sk = skb->sk;
1139 
1140 	atomic_sub(skb->truesize, &sk->sk_rmem_alloc);
1141 	sk_mem_uncharge(skb->sk, skb->truesize);
1142 }
1143 
1144 
sock_i_uid(struct sock * sk)1145 int sock_i_uid(struct sock *sk)
1146 {
1147 	int uid;
1148 
1149 	read_lock(&sk->sk_callback_lock);
1150 	uid = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_uid : 0;
1151 	read_unlock(&sk->sk_callback_lock);
1152 	return uid;
1153 }
1154 
sock_i_ino(struct sock * sk)1155 unsigned long sock_i_ino(struct sock *sk)
1156 {
1157 	unsigned long ino;
1158 
1159 	read_lock(&sk->sk_callback_lock);
1160 	ino = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_ino : 0;
1161 	read_unlock(&sk->sk_callback_lock);
1162 	return ino;
1163 }
1164 
1165 /*
1166  * Allocate a skb from the socket's send buffer.
1167  */
sock_wmalloc(struct sock * sk,unsigned long size,int force,gfp_t priority)1168 struct sk_buff *sock_wmalloc(struct sock *sk, unsigned long size, int force,
1169 			     gfp_t priority)
1170 {
1171 	if (force || atomic_read(&sk->sk_wmem_alloc) < sk->sk_sndbuf) {
1172 		struct sk_buff * skb = alloc_skb(size, priority);
1173 		if (skb) {
1174 			skb_set_owner_w(skb, sk);
1175 			return skb;
1176 		}
1177 	}
1178 	return NULL;
1179 }
1180 
1181 /*
1182  * Allocate a skb from the socket's receive buffer.
1183  */
sock_rmalloc(struct sock * sk,unsigned long size,int force,gfp_t priority)1184 struct sk_buff *sock_rmalloc(struct sock *sk, unsigned long size, int force,
1185 			     gfp_t priority)
1186 {
1187 	if (force || atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf) {
1188 		struct sk_buff *skb = alloc_skb(size, priority);
1189 		if (skb) {
1190 			skb_set_owner_r(skb, sk);
1191 			return skb;
1192 		}
1193 	}
1194 	return NULL;
1195 }
1196 
1197 /*
1198  * Allocate a memory block from the socket's option memory buffer.
1199  */
sock_kmalloc(struct sock * sk,int size,gfp_t priority)1200 void *sock_kmalloc(struct sock *sk, int size, gfp_t priority)
1201 {
1202 	if ((unsigned)size <= sysctl_optmem_max &&
1203 	    atomic_read(&sk->sk_omem_alloc) + size < sysctl_optmem_max) {
1204 		void *mem;
1205 		/* First do the add, to avoid the race if kmalloc
1206 		 * might sleep.
1207 		 */
1208 		atomic_add(size, &sk->sk_omem_alloc);
1209 		mem = kmalloc(size, priority);
1210 		if (mem)
1211 			return mem;
1212 		atomic_sub(size, &sk->sk_omem_alloc);
1213 	}
1214 	return NULL;
1215 }
1216 
1217 /*
1218  * Free an option memory block.
1219  */
sock_kfree_s(struct sock * sk,void * mem,int size)1220 void sock_kfree_s(struct sock *sk, void *mem, int size)
1221 {
1222 	kfree(mem);
1223 	atomic_sub(size, &sk->sk_omem_alloc);
1224 }
1225 
1226 /* It is almost wait_for_tcp_memory minus release_sock/lock_sock.
1227    I think, these locks should be removed for datagram sockets.
1228  */
sock_wait_for_wmem(struct sock * sk,long timeo)1229 static long sock_wait_for_wmem(struct sock * sk, long timeo)
1230 {
1231 	DEFINE_WAIT(wait);
1232 
1233 	clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
1234 	for (;;) {
1235 		if (!timeo)
1236 			break;
1237 		if (signal_pending(current))
1238 			break;
1239 		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1240 		prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE);
1241 		if (atomic_read(&sk->sk_wmem_alloc) < sk->sk_sndbuf)
1242 			break;
1243 		if (sk->sk_shutdown & SEND_SHUTDOWN)
1244 			break;
1245 		if (sk->sk_err)
1246 			break;
1247 		timeo = schedule_timeout(timeo);
1248 	}
1249 	finish_wait(sk->sk_sleep, &wait);
1250 	return timeo;
1251 }
1252 
1253 
1254 /*
1255  *	Generic send/receive buffer handlers
1256  */
1257 
sock_alloc_send_pskb(struct sock * sk,unsigned long header_len,unsigned long data_len,int noblock,int * errcode)1258 static struct sk_buff *sock_alloc_send_pskb(struct sock *sk,
1259 					    unsigned long header_len,
1260 					    unsigned long data_len,
1261 					    int noblock, int *errcode)
1262 {
1263 	struct sk_buff *skb;
1264 	gfp_t gfp_mask;
1265 	long timeo;
1266 	int err;
1267 
1268 	gfp_mask = sk->sk_allocation;
1269 	if (gfp_mask & __GFP_WAIT)
1270 		gfp_mask |= __GFP_REPEAT;
1271 
1272 	timeo = sock_sndtimeo(sk, noblock);
1273 	while (1) {
1274 		err = sock_error(sk);
1275 		if (err != 0)
1276 			goto failure;
1277 
1278 		err = -EPIPE;
1279 		if (sk->sk_shutdown & SEND_SHUTDOWN)
1280 			goto failure;
1281 
1282 		if (atomic_read(&sk->sk_wmem_alloc) < sk->sk_sndbuf) {
1283 			skb = alloc_skb(header_len, gfp_mask);
1284 			if (skb) {
1285 				int npages;
1286 				int i;
1287 
1288 				/* No pages, we're done... */
1289 				if (!data_len)
1290 					break;
1291 
1292 				npages = (data_len + (PAGE_SIZE - 1)) >> PAGE_SHIFT;
1293 				skb->truesize += data_len;
1294 				skb_shinfo(skb)->nr_frags = npages;
1295 				for (i = 0; i < npages; i++) {
1296 					struct page *page;
1297 					skb_frag_t *frag;
1298 
1299 					page = alloc_pages(sk->sk_allocation, 0);
1300 					if (!page) {
1301 						err = -ENOBUFS;
1302 						skb_shinfo(skb)->nr_frags = i;
1303 						kfree_skb(skb);
1304 						goto failure;
1305 					}
1306 
1307 					frag = &skb_shinfo(skb)->frags[i];
1308 					frag->page = page;
1309 					frag->page_offset = 0;
1310 					frag->size = (data_len >= PAGE_SIZE ?
1311 						      PAGE_SIZE :
1312 						      data_len);
1313 					data_len -= PAGE_SIZE;
1314 				}
1315 
1316 				/* Full success... */
1317 				break;
1318 			}
1319 			err = -ENOBUFS;
1320 			goto failure;
1321 		}
1322 		set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
1323 		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1324 		err = -EAGAIN;
1325 		if (!timeo)
1326 			goto failure;
1327 		if (signal_pending(current))
1328 			goto interrupted;
1329 		timeo = sock_wait_for_wmem(sk, timeo);
1330 	}
1331 
1332 	skb_set_owner_w(skb, sk);
1333 	return skb;
1334 
1335 interrupted:
1336 	err = sock_intr_errno(timeo);
1337 failure:
1338 	*errcode = err;
1339 	return NULL;
1340 }
1341 
sock_alloc_send_skb(struct sock * sk,unsigned long size,int noblock,int * errcode)1342 struct sk_buff *sock_alloc_send_skb(struct sock *sk, unsigned long size,
1343 				    int noblock, int *errcode)
1344 {
1345 	return sock_alloc_send_pskb(sk, size, 0, noblock, errcode);
1346 }
1347 
__lock_sock(struct sock * sk)1348 static void __lock_sock(struct sock *sk)
1349 {
1350 	DEFINE_WAIT(wait);
1351 
1352 	for (;;) {
1353 		prepare_to_wait_exclusive(&sk->sk_lock.wq, &wait,
1354 					TASK_UNINTERRUPTIBLE);
1355 		spin_unlock_bh(&sk->sk_lock.slock);
1356 		schedule();
1357 		spin_lock_bh(&sk->sk_lock.slock);
1358 		if (!sock_owned_by_user(sk))
1359 			break;
1360 	}
1361 	finish_wait(&sk->sk_lock.wq, &wait);
1362 }
1363 
__release_sock(struct sock * sk)1364 static void __release_sock(struct sock *sk)
1365 {
1366 	struct sk_buff *skb = sk->sk_backlog.head;
1367 
1368 	do {
1369 		sk->sk_backlog.head = sk->sk_backlog.tail = NULL;
1370 		bh_unlock_sock(sk);
1371 
1372 		do {
1373 			struct sk_buff *next = skb->next;
1374 
1375 			skb->next = NULL;
1376 			sk_backlog_rcv(sk, skb);
1377 
1378 			/*
1379 			 * We are in process context here with softirqs
1380 			 * disabled, use cond_resched_softirq() to preempt.
1381 			 * This is safe to do because we've taken the backlog
1382 			 * queue private:
1383 			 */
1384 			cond_resched_softirq();
1385 
1386 			skb = next;
1387 		} while (skb != NULL);
1388 
1389 		bh_lock_sock(sk);
1390 	} while ((skb = sk->sk_backlog.head) != NULL);
1391 }
1392 
1393 /**
1394  * sk_wait_data - wait for data to arrive at sk_receive_queue
1395  * @sk:    sock to wait on
1396  * @timeo: for how long
1397  *
1398  * Now socket state including sk->sk_err is changed only under lock,
1399  * hence we may omit checks after joining wait queue.
1400  * We check receive queue before schedule() only as optimization;
1401  * it is very likely that release_sock() added new data.
1402  */
sk_wait_data(struct sock * sk,long * timeo)1403 int sk_wait_data(struct sock *sk, long *timeo)
1404 {
1405 	int rc;
1406 	DEFINE_WAIT(wait);
1407 
1408 	prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE);
1409 	set_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
1410 	rc = sk_wait_event(sk, timeo, !skb_queue_empty(&sk->sk_receive_queue));
1411 	clear_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
1412 	finish_wait(sk->sk_sleep, &wait);
1413 	return rc;
1414 }
1415 
1416 EXPORT_SYMBOL(sk_wait_data);
1417 
1418 /**
1419  *	__sk_mem_schedule - increase sk_forward_alloc and memory_allocated
1420  *	@sk: socket
1421  *	@size: memory size to allocate
1422  *	@kind: allocation type
1423  *
1424  *	If kind is SK_MEM_SEND, it means wmem allocation. Otherwise it means
1425  *	rmem allocation. This function assumes that protocols which have
1426  *	memory_pressure use sk_wmem_queued as write buffer accounting.
1427  */
__sk_mem_schedule(struct sock * sk,int size,int kind)1428 int __sk_mem_schedule(struct sock *sk, int size, int kind)
1429 {
1430 	struct proto *prot = sk->sk_prot;
1431 	int amt = sk_mem_pages(size);
1432 	int allocated;
1433 
1434 	sk->sk_forward_alloc += amt * SK_MEM_QUANTUM;
1435 	allocated = atomic_add_return(amt, prot->memory_allocated);
1436 
1437 	/* Under limit. */
1438 	if (allocated <= prot->sysctl_mem[0]) {
1439 		if (prot->memory_pressure && *prot->memory_pressure)
1440 			*prot->memory_pressure = 0;
1441 		return 1;
1442 	}
1443 
1444 	/* Under pressure. */
1445 	if (allocated > prot->sysctl_mem[1])
1446 		if (prot->enter_memory_pressure)
1447 			prot->enter_memory_pressure(sk);
1448 
1449 	/* Over hard limit. */
1450 	if (allocated > prot->sysctl_mem[2])
1451 		goto suppress_allocation;
1452 
1453 	/* guarantee minimum buffer size under pressure */
1454 	if (kind == SK_MEM_RECV) {
1455 		if (atomic_read(&sk->sk_rmem_alloc) < prot->sysctl_rmem[0])
1456 			return 1;
1457 	} else { /* SK_MEM_SEND */
1458 		if (sk->sk_type == SOCK_STREAM) {
1459 			if (sk->sk_wmem_queued < prot->sysctl_wmem[0])
1460 				return 1;
1461 		} else if (atomic_read(&sk->sk_wmem_alloc) <
1462 			   prot->sysctl_wmem[0])
1463 				return 1;
1464 	}
1465 
1466 	if (prot->memory_pressure) {
1467 		int alloc;
1468 
1469 		if (!*prot->memory_pressure)
1470 			return 1;
1471 		alloc = percpu_counter_read_positive(prot->sockets_allocated);
1472 		if (prot->sysctl_mem[2] > alloc *
1473 		    sk_mem_pages(sk->sk_wmem_queued +
1474 				 atomic_read(&sk->sk_rmem_alloc) +
1475 				 sk->sk_forward_alloc))
1476 			return 1;
1477 	}
1478 
1479 suppress_allocation:
1480 
1481 	if (kind == SK_MEM_SEND && sk->sk_type == SOCK_STREAM) {
1482 		sk_stream_moderate_sndbuf(sk);
1483 
1484 		/* Fail only if socket is _under_ its sndbuf.
1485 		 * In this case we cannot block, so that we have to fail.
1486 		 */
1487 		if (sk->sk_wmem_queued + size >= sk->sk_sndbuf)
1488 			return 1;
1489 	}
1490 
1491 	/* Alas. Undo changes. */
1492 	sk->sk_forward_alloc -= amt * SK_MEM_QUANTUM;
1493 	atomic_sub(amt, prot->memory_allocated);
1494 	return 0;
1495 }
1496 
1497 EXPORT_SYMBOL(__sk_mem_schedule);
1498 
1499 /**
1500  *	__sk_reclaim - reclaim memory_allocated
1501  *	@sk: socket
1502  */
__sk_mem_reclaim(struct sock * sk)1503 void __sk_mem_reclaim(struct sock *sk)
1504 {
1505 	struct proto *prot = sk->sk_prot;
1506 
1507 	atomic_sub(sk->sk_forward_alloc >> SK_MEM_QUANTUM_SHIFT,
1508 		   prot->memory_allocated);
1509 	sk->sk_forward_alloc &= SK_MEM_QUANTUM - 1;
1510 
1511 	if (prot->memory_pressure && *prot->memory_pressure &&
1512 	    (atomic_read(prot->memory_allocated) < prot->sysctl_mem[0]))
1513 		*prot->memory_pressure = 0;
1514 }
1515 
1516 EXPORT_SYMBOL(__sk_mem_reclaim);
1517 
1518 
1519 /*
1520  * Set of default routines for initialising struct proto_ops when
1521  * the protocol does not support a particular function. In certain
1522  * cases where it makes no sense for a protocol to have a "do nothing"
1523  * function, some default processing is provided.
1524  */
1525 
sock_no_bind(struct socket * sock,struct sockaddr * saddr,int len)1526 int sock_no_bind(struct socket *sock, struct sockaddr *saddr, int len)
1527 {
1528 	return -EOPNOTSUPP;
1529 }
1530 
sock_no_connect(struct socket * sock,struct sockaddr * saddr,int len,int flags)1531 int sock_no_connect(struct socket *sock, struct sockaddr *saddr,
1532 		    int len, int flags)
1533 {
1534 	return -EOPNOTSUPP;
1535 }
1536 
sock_no_socketpair(struct socket * sock1,struct socket * sock2)1537 int sock_no_socketpair(struct socket *sock1, struct socket *sock2)
1538 {
1539 	return -EOPNOTSUPP;
1540 }
1541 
sock_no_accept(struct socket * sock,struct socket * newsock,int flags)1542 int sock_no_accept(struct socket *sock, struct socket *newsock, int flags)
1543 {
1544 	return -EOPNOTSUPP;
1545 }
1546 
sock_no_getname(struct socket * sock,struct sockaddr * saddr,int * len,int peer)1547 int sock_no_getname(struct socket *sock, struct sockaddr *saddr,
1548 		    int *len, int peer)
1549 {
1550 	return -EOPNOTSUPP;
1551 }
1552 
sock_no_poll(struct file * file,struct socket * sock,poll_table * pt)1553 unsigned int sock_no_poll(struct file * file, struct socket *sock, poll_table *pt)
1554 {
1555 	return 0;
1556 }
1557 
sock_no_ioctl(struct socket * sock,unsigned int cmd,unsigned long arg)1558 int sock_no_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
1559 {
1560 	return -EOPNOTSUPP;
1561 }
1562 
sock_no_listen(struct socket * sock,int backlog)1563 int sock_no_listen(struct socket *sock, int backlog)
1564 {
1565 	return -EOPNOTSUPP;
1566 }
1567 
sock_no_shutdown(struct socket * sock,int how)1568 int sock_no_shutdown(struct socket *sock, int how)
1569 {
1570 	return -EOPNOTSUPP;
1571 }
1572 
sock_no_setsockopt(struct socket * sock,int level,int optname,char __user * optval,int optlen)1573 int sock_no_setsockopt(struct socket *sock, int level, int optname,
1574 		    char __user *optval, int optlen)
1575 {
1576 	return -EOPNOTSUPP;
1577 }
1578 
sock_no_getsockopt(struct socket * sock,int level,int optname,char __user * optval,int __user * optlen)1579 int sock_no_getsockopt(struct socket *sock, int level, int optname,
1580 		    char __user *optval, int __user *optlen)
1581 {
1582 	return -EOPNOTSUPP;
1583 }
1584 
sock_no_sendmsg(struct kiocb * iocb,struct socket * sock,struct msghdr * m,size_t len)1585 int sock_no_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *m,
1586 		    size_t len)
1587 {
1588 	return -EOPNOTSUPP;
1589 }
1590 
sock_no_recvmsg(struct kiocb * iocb,struct socket * sock,struct msghdr * m,size_t len,int flags)1591 int sock_no_recvmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *m,
1592 		    size_t len, int flags)
1593 {
1594 	return -EOPNOTSUPP;
1595 }
1596 
sock_no_mmap(struct file * file,struct socket * sock,struct vm_area_struct * vma)1597 int sock_no_mmap(struct file *file, struct socket *sock, struct vm_area_struct *vma)
1598 {
1599 	/* Mirror missing mmap method error code */
1600 	return -ENODEV;
1601 }
1602 
sock_no_sendpage(struct socket * sock,struct page * page,int offset,size_t size,int flags)1603 ssize_t sock_no_sendpage(struct socket *sock, struct page *page, int offset, size_t size, int flags)
1604 {
1605 	ssize_t res;
1606 	struct msghdr msg = {.msg_flags = flags};
1607 	struct kvec iov;
1608 	char *kaddr = kmap(page);
1609 	iov.iov_base = kaddr + offset;
1610 	iov.iov_len = size;
1611 	res = kernel_sendmsg(sock, &msg, &iov, 1, size);
1612 	kunmap(page);
1613 	return res;
1614 }
1615 
1616 /*
1617  *	Default Socket Callbacks
1618  */
1619 
sock_def_wakeup(struct sock * sk)1620 static void sock_def_wakeup(struct sock *sk)
1621 {
1622 	read_lock(&sk->sk_callback_lock);
1623 	if (sk->sk_sleep && waitqueue_active(sk->sk_sleep))
1624 		wake_up_interruptible_all(sk->sk_sleep);
1625 	read_unlock(&sk->sk_callback_lock);
1626 }
1627 
sock_def_error_report(struct sock * sk)1628 static void sock_def_error_report(struct sock *sk)
1629 {
1630 	read_lock(&sk->sk_callback_lock);
1631 	if (sk->sk_sleep && waitqueue_active(sk->sk_sleep))
1632 		wake_up_interruptible(sk->sk_sleep);
1633 	sk_wake_async(sk, SOCK_WAKE_IO, POLL_ERR);
1634 	read_unlock(&sk->sk_callback_lock);
1635 }
1636 
sock_def_readable(struct sock * sk,int len)1637 static void sock_def_readable(struct sock *sk, int len)
1638 {
1639 	read_lock(&sk->sk_callback_lock);
1640 	if (sk->sk_sleep && waitqueue_active(sk->sk_sleep))
1641 		wake_up_interruptible_sync(sk->sk_sleep);
1642 	sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
1643 	read_unlock(&sk->sk_callback_lock);
1644 }
1645 
sock_def_write_space(struct sock * sk)1646 static void sock_def_write_space(struct sock *sk)
1647 {
1648 	read_lock(&sk->sk_callback_lock);
1649 
1650 	/* Do not wake up a writer until he can make "significant"
1651 	 * progress.  --DaveM
1652 	 */
1653 	if ((atomic_read(&sk->sk_wmem_alloc) << 1) <= sk->sk_sndbuf) {
1654 		if (sk->sk_sleep && waitqueue_active(sk->sk_sleep))
1655 			wake_up_interruptible_sync(sk->sk_sleep);
1656 
1657 		/* Should agree with poll, otherwise some programs break */
1658 		if (sock_writeable(sk))
1659 			sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
1660 	}
1661 
1662 	read_unlock(&sk->sk_callback_lock);
1663 }
1664 
sock_def_destruct(struct sock * sk)1665 static void sock_def_destruct(struct sock *sk)
1666 {
1667 	kfree(sk->sk_protinfo);
1668 }
1669 
sk_send_sigurg(struct sock * sk)1670 void sk_send_sigurg(struct sock *sk)
1671 {
1672 	if (sk->sk_socket && sk->sk_socket->file)
1673 		if (send_sigurg(&sk->sk_socket->file->f_owner))
1674 			sk_wake_async(sk, SOCK_WAKE_URG, POLL_PRI);
1675 }
1676 
sk_reset_timer(struct sock * sk,struct timer_list * timer,unsigned long expires)1677 void sk_reset_timer(struct sock *sk, struct timer_list* timer,
1678 		    unsigned long expires)
1679 {
1680 	if (!mod_timer(timer, expires))
1681 		sock_hold(sk);
1682 }
1683 
1684 EXPORT_SYMBOL(sk_reset_timer);
1685 
sk_stop_timer(struct sock * sk,struct timer_list * timer)1686 void sk_stop_timer(struct sock *sk, struct timer_list* timer)
1687 {
1688 	if (timer_pending(timer) && del_timer(timer))
1689 		__sock_put(sk);
1690 }
1691 
1692 EXPORT_SYMBOL(sk_stop_timer);
1693 
sock_init_data(struct socket * sock,struct sock * sk)1694 void sock_init_data(struct socket *sock, struct sock *sk)
1695 {
1696 	skb_queue_head_init(&sk->sk_receive_queue);
1697 	skb_queue_head_init(&sk->sk_write_queue);
1698 	skb_queue_head_init(&sk->sk_error_queue);
1699 #ifdef CONFIG_NET_DMA
1700 	skb_queue_head_init(&sk->sk_async_wait_queue);
1701 #endif
1702 
1703 	sk->sk_send_head	=	NULL;
1704 
1705 	init_timer(&sk->sk_timer);
1706 
1707 	sk->sk_allocation	=	GFP_KERNEL;
1708 	sk->sk_rcvbuf		=	sysctl_rmem_default;
1709 	sk->sk_sndbuf		=	sysctl_wmem_default;
1710 	sk->sk_state		=	TCP_CLOSE;
1711 	sk_set_socket(sk, sock);
1712 
1713 	sock_set_flag(sk, SOCK_ZAPPED);
1714 
1715 	if (sock) {
1716 		sk->sk_type	=	sock->type;
1717 		sk->sk_sleep	=	&sock->wait;
1718 		sock->sk	=	sk;
1719 	} else
1720 		sk->sk_sleep	=	NULL;
1721 
1722 	rwlock_init(&sk->sk_dst_lock);
1723 	rwlock_init(&sk->sk_callback_lock);
1724 	lockdep_set_class_and_name(&sk->sk_callback_lock,
1725 			af_callback_keys + sk->sk_family,
1726 			af_family_clock_key_strings[sk->sk_family]);
1727 
1728 	sk->sk_state_change	=	sock_def_wakeup;
1729 	sk->sk_data_ready	=	sock_def_readable;
1730 	sk->sk_write_space	=	sock_def_write_space;
1731 	sk->sk_error_report	=	sock_def_error_report;
1732 	sk->sk_destruct		=	sock_def_destruct;
1733 
1734 	sk->sk_sndmsg_page	=	NULL;
1735 	sk->sk_sndmsg_off	=	0;
1736 
1737 	sk->sk_peercred.pid 	=	0;
1738 	sk->sk_peercred.uid	=	-1;
1739 	sk->sk_peercred.gid	=	-1;
1740 	sk->sk_write_pending	=	0;
1741 	sk->sk_rcvlowat		=	1;
1742 	sk->sk_rcvtimeo		=	MAX_SCHEDULE_TIMEOUT;
1743 	sk->sk_sndtimeo		=	MAX_SCHEDULE_TIMEOUT;
1744 
1745 	sk->sk_stamp = ktime_set(-1L, 0);
1746 
1747 	atomic_set(&sk->sk_refcnt, 1);
1748 	atomic_set(&sk->sk_drops, 0);
1749 }
1750 
lock_sock_nested(struct sock * sk,int subclass)1751 void lock_sock_nested(struct sock *sk, int subclass)
1752 {
1753 	might_sleep();
1754 	spin_lock_bh(&sk->sk_lock.slock);
1755 	if (sk->sk_lock.owned)
1756 		__lock_sock(sk);
1757 	sk->sk_lock.owned = 1;
1758 	spin_unlock(&sk->sk_lock.slock);
1759 	/*
1760 	 * The sk_lock has mutex_lock() semantics here:
1761 	 */
1762 	mutex_acquire(&sk->sk_lock.dep_map, subclass, 0, _RET_IP_);
1763 	local_bh_enable();
1764 }
1765 
1766 EXPORT_SYMBOL(lock_sock_nested);
1767 
release_sock(struct sock * sk)1768 void release_sock(struct sock *sk)
1769 {
1770 	/*
1771 	 * The sk_lock has mutex_unlock() semantics:
1772 	 */
1773 	mutex_release(&sk->sk_lock.dep_map, 1, _RET_IP_);
1774 
1775 	spin_lock_bh(&sk->sk_lock.slock);
1776 	if (sk->sk_backlog.tail)
1777 		__release_sock(sk);
1778 	sk->sk_lock.owned = 0;
1779 	if (waitqueue_active(&sk->sk_lock.wq))
1780 		wake_up(&sk->sk_lock.wq);
1781 	spin_unlock_bh(&sk->sk_lock.slock);
1782 }
1783 EXPORT_SYMBOL(release_sock);
1784 
sock_get_timestamp(struct sock * sk,struct timeval __user * userstamp)1785 int sock_get_timestamp(struct sock *sk, struct timeval __user *userstamp)
1786 {
1787 	struct timeval tv;
1788 	if (!sock_flag(sk, SOCK_TIMESTAMP))
1789 		sock_enable_timestamp(sk);
1790 	tv = ktime_to_timeval(sk->sk_stamp);
1791 	if (tv.tv_sec == -1)
1792 		return -ENOENT;
1793 	if (tv.tv_sec == 0) {
1794 		sk->sk_stamp = ktime_get_real();
1795 		tv = ktime_to_timeval(sk->sk_stamp);
1796 	}
1797 	return copy_to_user(userstamp, &tv, sizeof(tv)) ? -EFAULT : 0;
1798 }
1799 EXPORT_SYMBOL(sock_get_timestamp);
1800 
sock_get_timestampns(struct sock * sk,struct timespec __user * userstamp)1801 int sock_get_timestampns(struct sock *sk, struct timespec __user *userstamp)
1802 {
1803 	struct timespec ts;
1804 	if (!sock_flag(sk, SOCK_TIMESTAMP))
1805 		sock_enable_timestamp(sk);
1806 	ts = ktime_to_timespec(sk->sk_stamp);
1807 	if (ts.tv_sec == -1)
1808 		return -ENOENT;
1809 	if (ts.tv_sec == 0) {
1810 		sk->sk_stamp = ktime_get_real();
1811 		ts = ktime_to_timespec(sk->sk_stamp);
1812 	}
1813 	return copy_to_user(userstamp, &ts, sizeof(ts)) ? -EFAULT : 0;
1814 }
1815 EXPORT_SYMBOL(sock_get_timestampns);
1816 
sock_enable_timestamp(struct sock * sk)1817 void sock_enable_timestamp(struct sock *sk)
1818 {
1819 	if (!sock_flag(sk, SOCK_TIMESTAMP)) {
1820 		sock_set_flag(sk, SOCK_TIMESTAMP);
1821 		net_enable_timestamp();
1822 	}
1823 }
1824 
1825 /*
1826  *	Get a socket option on an socket.
1827  *
1828  *	FIX: POSIX 1003.1g is very ambiguous here. It states that
1829  *	asynchronous errors should be reported by getsockopt. We assume
1830  *	this means if you specify SO_ERROR (otherwise whats the point of it).
1831  */
sock_common_getsockopt(struct socket * sock,int level,int optname,char __user * optval,int __user * optlen)1832 int sock_common_getsockopt(struct socket *sock, int level, int optname,
1833 			   char __user *optval, int __user *optlen)
1834 {
1835 	struct sock *sk = sock->sk;
1836 
1837 	return sk->sk_prot->getsockopt(sk, level, optname, optval, optlen);
1838 }
1839 
1840 EXPORT_SYMBOL(sock_common_getsockopt);
1841 
1842 #ifdef CONFIG_COMPAT
compat_sock_common_getsockopt(struct socket * sock,int level,int optname,char __user * optval,int __user * optlen)1843 int compat_sock_common_getsockopt(struct socket *sock, int level, int optname,
1844 				  char __user *optval, int __user *optlen)
1845 {
1846 	struct sock *sk = sock->sk;
1847 
1848 	if (sk->sk_prot->compat_getsockopt != NULL)
1849 		return sk->sk_prot->compat_getsockopt(sk, level, optname,
1850 						      optval, optlen);
1851 	return sk->sk_prot->getsockopt(sk, level, optname, optval, optlen);
1852 }
1853 EXPORT_SYMBOL(compat_sock_common_getsockopt);
1854 #endif
1855 
sock_common_recvmsg(struct kiocb * iocb,struct socket * sock,struct msghdr * msg,size_t size,int flags)1856 int sock_common_recvmsg(struct kiocb *iocb, struct socket *sock,
1857 			struct msghdr *msg, size_t size, int flags)
1858 {
1859 	struct sock *sk = sock->sk;
1860 	int addr_len = 0;
1861 	int err;
1862 
1863 	err = sk->sk_prot->recvmsg(iocb, sk, msg, size, flags & MSG_DONTWAIT,
1864 				   flags & ~MSG_DONTWAIT, &addr_len);
1865 	if (err >= 0)
1866 		msg->msg_namelen = addr_len;
1867 	return err;
1868 }
1869 
1870 EXPORT_SYMBOL(sock_common_recvmsg);
1871 
1872 /*
1873  *	Set socket options on an inet socket.
1874  */
sock_common_setsockopt(struct socket * sock,int level,int optname,char __user * optval,int optlen)1875 int sock_common_setsockopt(struct socket *sock, int level, int optname,
1876 			   char __user *optval, int optlen)
1877 {
1878 	struct sock *sk = sock->sk;
1879 
1880 	return sk->sk_prot->setsockopt(sk, level, optname, optval, optlen);
1881 }
1882 
1883 EXPORT_SYMBOL(sock_common_setsockopt);
1884 
1885 #ifdef CONFIG_COMPAT
compat_sock_common_setsockopt(struct socket * sock,int level,int optname,char __user * optval,int optlen)1886 int compat_sock_common_setsockopt(struct socket *sock, int level, int optname,
1887 				  char __user *optval, int optlen)
1888 {
1889 	struct sock *sk = sock->sk;
1890 
1891 	if (sk->sk_prot->compat_setsockopt != NULL)
1892 		return sk->sk_prot->compat_setsockopt(sk, level, optname,
1893 						      optval, optlen);
1894 	return sk->sk_prot->setsockopt(sk, level, optname, optval, optlen);
1895 }
1896 EXPORT_SYMBOL(compat_sock_common_setsockopt);
1897 #endif
1898 
sk_common_release(struct sock * sk)1899 void sk_common_release(struct sock *sk)
1900 {
1901 	if (sk->sk_prot->destroy)
1902 		sk->sk_prot->destroy(sk);
1903 
1904 	/*
1905 	 * Observation: when sock_common_release is called, processes have
1906 	 * no access to socket. But net still has.
1907 	 * Step one, detach it from networking:
1908 	 *
1909 	 * A. Remove from hash tables.
1910 	 */
1911 
1912 	sk->sk_prot->unhash(sk);
1913 
1914 	/*
1915 	 * In this point socket cannot receive new packets, but it is possible
1916 	 * that some packets are in flight because some CPU runs receiver and
1917 	 * did hash table lookup before we unhashed socket. They will achieve
1918 	 * receive queue and will be purged by socket destructor.
1919 	 *
1920 	 * Also we still have packets pending on receive queue and probably,
1921 	 * our own packets waiting in device queues. sock_destroy will drain
1922 	 * receive queue, but transmitted packets will delay socket destruction
1923 	 * until the last reference will be released.
1924 	 */
1925 
1926 	sock_orphan(sk);
1927 
1928 	xfrm_sk_free_policy(sk);
1929 
1930 	sk_refcnt_debug_release(sk);
1931 	sock_put(sk);
1932 }
1933 
1934 EXPORT_SYMBOL(sk_common_release);
1935 
1936 static DEFINE_RWLOCK(proto_list_lock);
1937 static LIST_HEAD(proto_list);
1938 
1939 #ifdef CONFIG_PROC_FS
1940 #define PROTO_INUSE_NR	64	/* should be enough for the first time */
1941 struct prot_inuse {
1942 	int val[PROTO_INUSE_NR];
1943 };
1944 
1945 static DECLARE_BITMAP(proto_inuse_idx, PROTO_INUSE_NR);
1946 
1947 #ifdef CONFIG_NET_NS
sock_prot_inuse_add(struct net * net,struct proto * prot,int val)1948 void sock_prot_inuse_add(struct net *net, struct proto *prot, int val)
1949 {
1950 	int cpu = smp_processor_id();
1951 	per_cpu_ptr(net->core.inuse, cpu)->val[prot->inuse_idx] += val;
1952 }
1953 EXPORT_SYMBOL_GPL(sock_prot_inuse_add);
1954 
sock_prot_inuse_get(struct net * net,struct proto * prot)1955 int sock_prot_inuse_get(struct net *net, struct proto *prot)
1956 {
1957 	int cpu, idx = prot->inuse_idx;
1958 	int res = 0;
1959 
1960 	for_each_possible_cpu(cpu)
1961 		res += per_cpu_ptr(net->core.inuse, cpu)->val[idx];
1962 
1963 	return res >= 0 ? res : 0;
1964 }
1965 EXPORT_SYMBOL_GPL(sock_prot_inuse_get);
1966 
sock_inuse_init_net(struct net * net)1967 static int sock_inuse_init_net(struct net *net)
1968 {
1969 	net->core.inuse = alloc_percpu(struct prot_inuse);
1970 	return net->core.inuse ? 0 : -ENOMEM;
1971 }
1972 
sock_inuse_exit_net(struct net * net)1973 static void sock_inuse_exit_net(struct net *net)
1974 {
1975 	free_percpu(net->core.inuse);
1976 }
1977 
1978 static struct pernet_operations net_inuse_ops = {
1979 	.init = sock_inuse_init_net,
1980 	.exit = sock_inuse_exit_net,
1981 };
1982 
net_inuse_init(void)1983 static __init int net_inuse_init(void)
1984 {
1985 	if (register_pernet_subsys(&net_inuse_ops))
1986 		panic("Cannot initialize net inuse counters");
1987 
1988 	return 0;
1989 }
1990 
1991 core_initcall(net_inuse_init);
1992 #else
1993 static DEFINE_PER_CPU(struct prot_inuse, prot_inuse);
1994 
sock_prot_inuse_add(struct net * net,struct proto * prot,int val)1995 void sock_prot_inuse_add(struct net *net, struct proto *prot, int val)
1996 {
1997 	__get_cpu_var(prot_inuse).val[prot->inuse_idx] += val;
1998 }
1999 EXPORT_SYMBOL_GPL(sock_prot_inuse_add);
2000 
sock_prot_inuse_get(struct net * net,struct proto * prot)2001 int sock_prot_inuse_get(struct net *net, struct proto *prot)
2002 {
2003 	int cpu, idx = prot->inuse_idx;
2004 	int res = 0;
2005 
2006 	for_each_possible_cpu(cpu)
2007 		res += per_cpu(prot_inuse, cpu).val[idx];
2008 
2009 	return res >= 0 ? res : 0;
2010 }
2011 EXPORT_SYMBOL_GPL(sock_prot_inuse_get);
2012 #endif
2013 
assign_proto_idx(struct proto * prot)2014 static void assign_proto_idx(struct proto *prot)
2015 {
2016 	prot->inuse_idx = find_first_zero_bit(proto_inuse_idx, PROTO_INUSE_NR);
2017 
2018 	if (unlikely(prot->inuse_idx == PROTO_INUSE_NR - 1)) {
2019 		printk(KERN_ERR "PROTO_INUSE_NR exhausted\n");
2020 		return;
2021 	}
2022 
2023 	set_bit(prot->inuse_idx, proto_inuse_idx);
2024 }
2025 
release_proto_idx(struct proto * prot)2026 static void release_proto_idx(struct proto *prot)
2027 {
2028 	if (prot->inuse_idx != PROTO_INUSE_NR - 1)
2029 		clear_bit(prot->inuse_idx, proto_inuse_idx);
2030 }
2031 #else
assign_proto_idx(struct proto * prot)2032 static inline void assign_proto_idx(struct proto *prot)
2033 {
2034 }
2035 
release_proto_idx(struct proto * prot)2036 static inline void release_proto_idx(struct proto *prot)
2037 {
2038 }
2039 #endif
2040 
proto_register(struct proto * prot,int alloc_slab)2041 int proto_register(struct proto *prot, int alloc_slab)
2042 {
2043 	if (alloc_slab) {
2044 		prot->slab = kmem_cache_create(prot->name, prot->obj_size, 0,
2045 					SLAB_HWCACHE_ALIGN | prot->slab_flags,
2046 					NULL);
2047 
2048 		if (prot->slab == NULL) {
2049 			printk(KERN_CRIT "%s: Can't create sock SLAB cache!\n",
2050 			       prot->name);
2051 			goto out;
2052 		}
2053 
2054 		if (prot->rsk_prot != NULL) {
2055 			static const char mask[] = "request_sock_%s";
2056 
2057 			prot->rsk_prot->slab_name = kmalloc(strlen(prot->name) + sizeof(mask) - 1, GFP_KERNEL);
2058 			if (prot->rsk_prot->slab_name == NULL)
2059 				goto out_free_sock_slab;
2060 
2061 			sprintf(prot->rsk_prot->slab_name, mask, prot->name);
2062 			prot->rsk_prot->slab = kmem_cache_create(prot->rsk_prot->slab_name,
2063 								 prot->rsk_prot->obj_size, 0,
2064 								 SLAB_HWCACHE_ALIGN, NULL);
2065 
2066 			if (prot->rsk_prot->slab == NULL) {
2067 				printk(KERN_CRIT "%s: Can't create request sock SLAB cache!\n",
2068 				       prot->name);
2069 				goto out_free_request_sock_slab_name;
2070 			}
2071 		}
2072 
2073 		if (prot->twsk_prot != NULL) {
2074 			static const char mask[] = "tw_sock_%s";
2075 
2076 			prot->twsk_prot->twsk_slab_name = kmalloc(strlen(prot->name) + sizeof(mask) - 1, GFP_KERNEL);
2077 
2078 			if (prot->twsk_prot->twsk_slab_name == NULL)
2079 				goto out_free_request_sock_slab;
2080 
2081 			sprintf(prot->twsk_prot->twsk_slab_name, mask, prot->name);
2082 			prot->twsk_prot->twsk_slab =
2083 				kmem_cache_create(prot->twsk_prot->twsk_slab_name,
2084 						  prot->twsk_prot->twsk_obj_size,
2085 						  0,
2086 						  SLAB_HWCACHE_ALIGN |
2087 							prot->slab_flags,
2088 						  NULL);
2089 			if (prot->twsk_prot->twsk_slab == NULL)
2090 				goto out_free_timewait_sock_slab_name;
2091 		}
2092 	}
2093 
2094 	write_lock(&proto_list_lock);
2095 	list_add(&prot->node, &proto_list);
2096 	assign_proto_idx(prot);
2097 	write_unlock(&proto_list_lock);
2098 	return 0;
2099 
2100 out_free_timewait_sock_slab_name:
2101 	kfree(prot->twsk_prot->twsk_slab_name);
2102 out_free_request_sock_slab:
2103 	if (prot->rsk_prot && prot->rsk_prot->slab) {
2104 		kmem_cache_destroy(prot->rsk_prot->slab);
2105 		prot->rsk_prot->slab = NULL;
2106 	}
2107 out_free_request_sock_slab_name:
2108 	kfree(prot->rsk_prot->slab_name);
2109 out_free_sock_slab:
2110 	kmem_cache_destroy(prot->slab);
2111 	prot->slab = NULL;
2112 out:
2113 	return -ENOBUFS;
2114 }
2115 
2116 EXPORT_SYMBOL(proto_register);
2117 
proto_unregister(struct proto * prot)2118 void proto_unregister(struct proto *prot)
2119 {
2120 	write_lock(&proto_list_lock);
2121 	release_proto_idx(prot);
2122 	list_del(&prot->node);
2123 	write_unlock(&proto_list_lock);
2124 
2125 	if (prot->slab != NULL) {
2126 		kmem_cache_destroy(prot->slab);
2127 		prot->slab = NULL;
2128 	}
2129 
2130 	if (prot->rsk_prot != NULL && prot->rsk_prot->slab != NULL) {
2131 		kmem_cache_destroy(prot->rsk_prot->slab);
2132 		kfree(prot->rsk_prot->slab_name);
2133 		prot->rsk_prot->slab = NULL;
2134 	}
2135 
2136 	if (prot->twsk_prot != NULL && prot->twsk_prot->twsk_slab != NULL) {
2137 		kmem_cache_destroy(prot->twsk_prot->twsk_slab);
2138 		kfree(prot->twsk_prot->twsk_slab_name);
2139 		prot->twsk_prot->twsk_slab = NULL;
2140 	}
2141 }
2142 
2143 EXPORT_SYMBOL(proto_unregister);
2144 
2145 #ifdef CONFIG_PROC_FS
proto_seq_start(struct seq_file * seq,loff_t * pos)2146 static void *proto_seq_start(struct seq_file *seq, loff_t *pos)
2147 	__acquires(proto_list_lock)
2148 {
2149 	read_lock(&proto_list_lock);
2150 	return seq_list_start_head(&proto_list, *pos);
2151 }
2152 
proto_seq_next(struct seq_file * seq,void * v,loff_t * pos)2153 static void *proto_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2154 {
2155 	return seq_list_next(v, &proto_list, pos);
2156 }
2157 
proto_seq_stop(struct seq_file * seq,void * v)2158 static void proto_seq_stop(struct seq_file *seq, void *v)
2159 	__releases(proto_list_lock)
2160 {
2161 	read_unlock(&proto_list_lock);
2162 }
2163 
proto_method_implemented(const void * method)2164 static char proto_method_implemented(const void *method)
2165 {
2166 	return method == NULL ? 'n' : 'y';
2167 }
2168 
proto_seq_printf(struct seq_file * seq,struct proto * proto)2169 static void proto_seq_printf(struct seq_file *seq, struct proto *proto)
2170 {
2171 	seq_printf(seq, "%-9s %4u %6d  %6d   %-3s %6u   %-3s  %-10s "
2172 			"%2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c\n",
2173 		   proto->name,
2174 		   proto->obj_size,
2175 		   sock_prot_inuse_get(seq_file_net(seq), proto),
2176 		   proto->memory_allocated != NULL ? atomic_read(proto->memory_allocated) : -1,
2177 		   proto->memory_pressure != NULL ? *proto->memory_pressure ? "yes" : "no" : "NI",
2178 		   proto->max_header,
2179 		   proto->slab == NULL ? "no" : "yes",
2180 		   module_name(proto->owner),
2181 		   proto_method_implemented(proto->close),
2182 		   proto_method_implemented(proto->connect),
2183 		   proto_method_implemented(proto->disconnect),
2184 		   proto_method_implemented(proto->accept),
2185 		   proto_method_implemented(proto->ioctl),
2186 		   proto_method_implemented(proto->init),
2187 		   proto_method_implemented(proto->destroy),
2188 		   proto_method_implemented(proto->shutdown),
2189 		   proto_method_implemented(proto->setsockopt),
2190 		   proto_method_implemented(proto->getsockopt),
2191 		   proto_method_implemented(proto->sendmsg),
2192 		   proto_method_implemented(proto->recvmsg),
2193 		   proto_method_implemented(proto->sendpage),
2194 		   proto_method_implemented(proto->bind),
2195 		   proto_method_implemented(proto->backlog_rcv),
2196 		   proto_method_implemented(proto->hash),
2197 		   proto_method_implemented(proto->unhash),
2198 		   proto_method_implemented(proto->get_port),
2199 		   proto_method_implemented(proto->enter_memory_pressure));
2200 }
2201 
proto_seq_show(struct seq_file * seq,void * v)2202 static int proto_seq_show(struct seq_file *seq, void *v)
2203 {
2204 	if (v == &proto_list)
2205 		seq_printf(seq, "%-9s %-4s %-8s %-6s %-5s %-7s %-4s %-10s %s",
2206 			   "protocol",
2207 			   "size",
2208 			   "sockets",
2209 			   "memory",
2210 			   "press",
2211 			   "maxhdr",
2212 			   "slab",
2213 			   "module",
2214 			   "cl co di ac io in de sh ss gs se re sp bi br ha uh gp em\n");
2215 	else
2216 		proto_seq_printf(seq, list_entry(v, struct proto, node));
2217 	return 0;
2218 }
2219 
2220 static const struct seq_operations proto_seq_ops = {
2221 	.start  = proto_seq_start,
2222 	.next   = proto_seq_next,
2223 	.stop   = proto_seq_stop,
2224 	.show   = proto_seq_show,
2225 };
2226 
proto_seq_open(struct inode * inode,struct file * file)2227 static int proto_seq_open(struct inode *inode, struct file *file)
2228 {
2229 	return seq_open_net(inode, file, &proto_seq_ops,
2230 			    sizeof(struct seq_net_private));
2231 }
2232 
2233 static const struct file_operations proto_seq_fops = {
2234 	.owner		= THIS_MODULE,
2235 	.open		= proto_seq_open,
2236 	.read		= seq_read,
2237 	.llseek		= seq_lseek,
2238 	.release	= seq_release_net,
2239 };
2240 
proto_init_net(struct net * net)2241 static __net_init int proto_init_net(struct net *net)
2242 {
2243 	if (!proc_net_fops_create(net, "protocols", S_IRUGO, &proto_seq_fops))
2244 		return -ENOMEM;
2245 
2246 	return 0;
2247 }
2248 
proto_exit_net(struct net * net)2249 static __net_exit void proto_exit_net(struct net *net)
2250 {
2251 	proc_net_remove(net, "protocols");
2252 }
2253 
2254 
2255 static __net_initdata struct pernet_operations proto_net_ops = {
2256 	.init = proto_init_net,
2257 	.exit = proto_exit_net,
2258 };
2259 
proto_init(void)2260 static int __init proto_init(void)
2261 {
2262 	return register_pernet_subsys(&proto_net_ops);
2263 }
2264 
2265 subsys_initcall(proto_init);
2266 
2267 #endif /* PROC_FS */
2268 
2269 EXPORT_SYMBOL(sk_alloc);
2270 EXPORT_SYMBOL(sk_free);
2271 EXPORT_SYMBOL(sk_send_sigurg);
2272 EXPORT_SYMBOL(sock_alloc_send_skb);
2273 EXPORT_SYMBOL(sock_init_data);
2274 EXPORT_SYMBOL(sock_kfree_s);
2275 EXPORT_SYMBOL(sock_kmalloc);
2276 EXPORT_SYMBOL(sock_no_accept);
2277 EXPORT_SYMBOL(sock_no_bind);
2278 EXPORT_SYMBOL(sock_no_connect);
2279 EXPORT_SYMBOL(sock_no_getname);
2280 EXPORT_SYMBOL(sock_no_getsockopt);
2281 EXPORT_SYMBOL(sock_no_ioctl);
2282 EXPORT_SYMBOL(sock_no_listen);
2283 EXPORT_SYMBOL(sock_no_mmap);
2284 EXPORT_SYMBOL(sock_no_poll);
2285 EXPORT_SYMBOL(sock_no_recvmsg);
2286 EXPORT_SYMBOL(sock_no_sendmsg);
2287 EXPORT_SYMBOL(sock_no_sendpage);
2288 EXPORT_SYMBOL(sock_no_setsockopt);
2289 EXPORT_SYMBOL(sock_no_shutdown);
2290 EXPORT_SYMBOL(sock_no_socketpair);
2291 EXPORT_SYMBOL(sock_rfree);
2292 EXPORT_SYMBOL(sock_setsockopt);
2293 EXPORT_SYMBOL(sock_wfree);
2294 EXPORT_SYMBOL(sock_wmalloc);
2295 EXPORT_SYMBOL(sock_i_uid);
2296 EXPORT_SYMBOL(sock_i_ino);
2297 EXPORT_SYMBOL(sysctl_optmem_max);
2298