xref: /linux/net/core/sock.c (revision 3fd6c59042dbba50391e30862beac979491145fe)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * INET		An implementation of the TCP/IP protocol suite for the LINUX
4  *		operating system.  INET is implemented using the  BSD Socket
5  *		interface as the means of communication with the user level.
6  *
7  *		Generic socket support routines. Memory allocators, socket lock/release
8  *		handler for protocols to use and generic option handler.
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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
87 
88 #include <linux/unaligned.h>
89 #include <linux/capability.h>
90 #include <linux/errno.h>
91 #include <linux/errqueue.h>
92 #include <linux/types.h>
93 #include <linux/socket.h>
94 #include <linux/in.h>
95 #include <linux/kernel.h>
96 #include <linux/module.h>
97 #include <linux/proc_fs.h>
98 #include <linux/seq_file.h>
99 #include <linux/sched.h>
100 #include <linux/sched/mm.h>
101 #include <linux/timer.h>
102 #include <linux/string.h>
103 #include <linux/sockios.h>
104 #include <linux/net.h>
105 #include <linux/mm.h>
106 #include <linux/slab.h>
107 #include <linux/interrupt.h>
108 #include <linux/poll.h>
109 #include <linux/tcp.h>
110 #include <linux/udp.h>
111 #include <linux/init.h>
112 #include <linux/highmem.h>
113 #include <linux/user_namespace.h>
114 #include <linux/static_key.h>
115 #include <linux/memcontrol.h>
116 #include <linux/prefetch.h>
117 #include <linux/compat.h>
118 #include <linux/mroute.h>
119 #include <linux/mroute6.h>
120 #include <linux/icmpv6.h>
121 
122 #include <linux/uaccess.h>
123 
124 #include <linux/netdevice.h>
125 #include <net/protocol.h>
126 #include <linux/skbuff.h>
127 #include <linux/skbuff_ref.h>
128 #include <net/net_namespace.h>
129 #include <net/request_sock.h>
130 #include <net/sock.h>
131 #include <net/proto_memory.h>
132 #include <linux/net_tstamp.h>
133 #include <net/xfrm.h>
134 #include <linux/ipsec.h>
135 #include <net/cls_cgroup.h>
136 #include <net/netprio_cgroup.h>
137 #include <linux/sock_diag.h>
138 
139 #include <linux/filter.h>
140 #include <net/sock_reuseport.h>
141 #include <net/bpf_sk_storage.h>
142 
143 #include <trace/events/sock.h>
144 
145 #include <net/tcp.h>
146 #include <net/busy_poll.h>
147 #include <net/phonet/phonet.h>
148 
149 #include <linux/ethtool.h>
150 
151 #include "dev.h"
152 
153 static DEFINE_MUTEX(proto_list_mutex);
154 static LIST_HEAD(proto_list);
155 
156 static void sock_def_write_space_wfree(struct sock *sk);
157 static void sock_def_write_space(struct sock *sk);
158 
159 /**
160  * sk_ns_capable - General socket capability test
161  * @sk: Socket to use a capability on or through
162  * @user_ns: The user namespace of the capability to use
163  * @cap: The capability to use
164  *
165  * Test to see if the opener of the socket had when the socket was
166  * created and the current process has the capability @cap in the user
167  * namespace @user_ns.
168  */
sk_ns_capable(const struct sock * sk,struct user_namespace * user_ns,int cap)169 bool sk_ns_capable(const struct sock *sk,
170 		   struct user_namespace *user_ns, int cap)
171 {
172 	return file_ns_capable(sk->sk_socket->file, user_ns, cap) &&
173 		ns_capable(user_ns, cap);
174 }
175 EXPORT_SYMBOL(sk_ns_capable);
176 
177 /**
178  * sk_capable - Socket global capability test
179  * @sk: Socket to use a capability on or through
180  * @cap: The global capability to use
181  *
182  * Test to see if the opener of the socket had when the socket was
183  * created and the current process has the capability @cap in all user
184  * namespaces.
185  */
sk_capable(const struct sock * sk,int cap)186 bool sk_capable(const struct sock *sk, int cap)
187 {
188 	return sk_ns_capable(sk, &init_user_ns, cap);
189 }
190 EXPORT_SYMBOL(sk_capable);
191 
192 /**
193  * sk_net_capable - Network namespace socket capability test
194  * @sk: Socket to use a capability on or through
195  * @cap: The capability to use
196  *
197  * Test to see if the opener of the socket had when the socket was created
198  * and the current process has the capability @cap over the network namespace
199  * the socket is a member of.
200  */
sk_net_capable(const struct sock * sk,int cap)201 bool sk_net_capable(const struct sock *sk, int cap)
202 {
203 	return sk_ns_capable(sk, sock_net(sk)->user_ns, cap);
204 }
205 EXPORT_SYMBOL(sk_net_capable);
206 
207 /*
208  * Each address family might have different locking rules, so we have
209  * one slock key per address family and separate keys for internal and
210  * userspace sockets.
211  */
212 static struct lock_class_key af_family_keys[AF_MAX];
213 static struct lock_class_key af_family_kern_keys[AF_MAX];
214 static struct lock_class_key af_family_slock_keys[AF_MAX];
215 static struct lock_class_key af_family_kern_slock_keys[AF_MAX];
216 
217 /*
218  * Make lock validator output more readable. (we pre-construct these
219  * strings build-time, so that runtime initialization of socket
220  * locks is fast):
221  */
222 
223 #define _sock_locks(x)						  \
224   x "AF_UNSPEC",	x "AF_UNIX"     ,	x "AF_INET"     , \
225   x "AF_AX25"  ,	x "AF_IPX"      ,	x "AF_APPLETALK", \
226   x "AF_NETROM",	x "AF_BRIDGE"   ,	x "AF_ATMPVC"   , \
227   x "AF_X25"   ,	x "AF_INET6"    ,	x "AF_ROSE"     , \
228   x "AF_DECnet",	x "AF_NETBEUI"  ,	x "AF_SECURITY" , \
229   x "AF_KEY"   ,	x "AF_NETLINK"  ,	x "AF_PACKET"   , \
230   x "AF_ASH"   ,	x "AF_ECONET"   ,	x "AF_ATMSVC"   , \
231   x "AF_RDS"   ,	x "AF_SNA"      ,	x "AF_IRDA"     , \
232   x "AF_PPPOX" ,	x "AF_WANPIPE"  ,	x "AF_LLC"      , \
233   x "27"       ,	x "28"          ,	x "AF_CAN"      , \
234   x "AF_TIPC"  ,	x "AF_BLUETOOTH",	x "IUCV"        , \
235   x "AF_RXRPC" ,	x "AF_ISDN"     ,	x "AF_PHONET"   , \
236   x "AF_IEEE802154",	x "AF_CAIF"	,	x "AF_ALG"      , \
237   x "AF_NFC"   ,	x "AF_VSOCK"    ,	x "AF_KCM"      , \
238   x "AF_QIPCRTR",	x "AF_SMC"	,	x "AF_XDP"	, \
239   x "AF_MCTP"  , \
240   x "AF_MAX"
241 
242 static const char *const af_family_key_strings[AF_MAX+1] = {
243 	_sock_locks("sk_lock-")
244 };
245 static const char *const af_family_slock_key_strings[AF_MAX+1] = {
246 	_sock_locks("slock-")
247 };
248 static const char *const af_family_clock_key_strings[AF_MAX+1] = {
249 	_sock_locks("clock-")
250 };
251 
252 static const char *const af_family_kern_key_strings[AF_MAX+1] = {
253 	_sock_locks("k-sk_lock-")
254 };
255 static const char *const af_family_kern_slock_key_strings[AF_MAX+1] = {
256 	_sock_locks("k-slock-")
257 };
258 static const char *const af_family_kern_clock_key_strings[AF_MAX+1] = {
259 	_sock_locks("k-clock-")
260 };
261 static const char *const af_family_rlock_key_strings[AF_MAX+1] = {
262 	_sock_locks("rlock-")
263 };
264 static const char *const af_family_wlock_key_strings[AF_MAX+1] = {
265 	_sock_locks("wlock-")
266 };
267 static const char *const af_family_elock_key_strings[AF_MAX+1] = {
268 	_sock_locks("elock-")
269 };
270 
271 /*
272  * sk_callback_lock and sk queues locking rules are per-address-family,
273  * so split the lock classes by using a per-AF key:
274  */
275 static struct lock_class_key af_callback_keys[AF_MAX];
276 static struct lock_class_key af_rlock_keys[AF_MAX];
277 static struct lock_class_key af_wlock_keys[AF_MAX];
278 static struct lock_class_key af_elock_keys[AF_MAX];
279 static struct lock_class_key af_kern_callback_keys[AF_MAX];
280 
281 /* Run time adjustable parameters. */
282 __u32 sysctl_wmem_max __read_mostly = SK_WMEM_MAX;
283 EXPORT_SYMBOL(sysctl_wmem_max);
284 __u32 sysctl_rmem_max __read_mostly = SK_RMEM_MAX;
285 EXPORT_SYMBOL(sysctl_rmem_max);
286 __u32 sysctl_wmem_default __read_mostly = SK_WMEM_MAX;
287 __u32 sysctl_rmem_default __read_mostly = SK_RMEM_MAX;
288 
289 DEFINE_STATIC_KEY_FALSE(memalloc_socks_key);
290 EXPORT_SYMBOL_GPL(memalloc_socks_key);
291 
292 /**
293  * sk_set_memalloc - sets %SOCK_MEMALLOC
294  * @sk: socket to set it on
295  *
296  * Set %SOCK_MEMALLOC on a socket for access to emergency reserves.
297  * It's the responsibility of the admin to adjust min_free_kbytes
298  * to meet the requirements
299  */
sk_set_memalloc(struct sock * sk)300 void sk_set_memalloc(struct sock *sk)
301 {
302 	sock_set_flag(sk, SOCK_MEMALLOC);
303 	sk->sk_allocation |= __GFP_MEMALLOC;
304 	static_branch_inc(&memalloc_socks_key);
305 }
306 EXPORT_SYMBOL_GPL(sk_set_memalloc);
307 
sk_clear_memalloc(struct sock * sk)308 void sk_clear_memalloc(struct sock *sk)
309 {
310 	sock_reset_flag(sk, SOCK_MEMALLOC);
311 	sk->sk_allocation &= ~__GFP_MEMALLOC;
312 	static_branch_dec(&memalloc_socks_key);
313 
314 	/*
315 	 * SOCK_MEMALLOC is allowed to ignore rmem limits to ensure forward
316 	 * progress of swapping. SOCK_MEMALLOC may be cleared while
317 	 * it has rmem allocations due to the last swapfile being deactivated
318 	 * but there is a risk that the socket is unusable due to exceeding
319 	 * the rmem limits. Reclaim the reserves and obey rmem limits again.
320 	 */
321 	sk_mem_reclaim(sk);
322 }
323 EXPORT_SYMBOL_GPL(sk_clear_memalloc);
324 
__sk_backlog_rcv(struct sock * sk,struct sk_buff * skb)325 int __sk_backlog_rcv(struct sock *sk, struct sk_buff *skb)
326 {
327 	int ret;
328 	unsigned int noreclaim_flag;
329 
330 	/* these should have been dropped before queueing */
331 	BUG_ON(!sock_flag(sk, SOCK_MEMALLOC));
332 
333 	noreclaim_flag = memalloc_noreclaim_save();
334 	ret = INDIRECT_CALL_INET(sk->sk_backlog_rcv,
335 				 tcp_v6_do_rcv,
336 				 tcp_v4_do_rcv,
337 				 sk, skb);
338 	memalloc_noreclaim_restore(noreclaim_flag);
339 
340 	return ret;
341 }
342 EXPORT_SYMBOL(__sk_backlog_rcv);
343 
sk_error_report(struct sock * sk)344 void sk_error_report(struct sock *sk)
345 {
346 	sk->sk_error_report(sk);
347 
348 	switch (sk->sk_family) {
349 	case AF_INET:
350 		fallthrough;
351 	case AF_INET6:
352 		trace_inet_sk_error_report(sk);
353 		break;
354 	default:
355 		break;
356 	}
357 }
358 EXPORT_SYMBOL(sk_error_report);
359 
sock_get_timeout(long timeo,void * optval,bool old_timeval)360 int sock_get_timeout(long timeo, void *optval, bool old_timeval)
361 {
362 	struct __kernel_sock_timeval tv;
363 
364 	if (timeo == MAX_SCHEDULE_TIMEOUT) {
365 		tv.tv_sec = 0;
366 		tv.tv_usec = 0;
367 	} else {
368 		tv.tv_sec = timeo / HZ;
369 		tv.tv_usec = ((timeo % HZ) * USEC_PER_SEC) / HZ;
370 	}
371 
372 	if (old_timeval && in_compat_syscall() && !COMPAT_USE_64BIT_TIME) {
373 		struct old_timeval32 tv32 = { tv.tv_sec, tv.tv_usec };
374 		*(struct old_timeval32 *)optval = tv32;
375 		return sizeof(tv32);
376 	}
377 
378 	if (old_timeval) {
379 		struct __kernel_old_timeval old_tv;
380 		old_tv.tv_sec = tv.tv_sec;
381 		old_tv.tv_usec = tv.tv_usec;
382 		*(struct __kernel_old_timeval *)optval = old_tv;
383 		return sizeof(old_tv);
384 	}
385 
386 	*(struct __kernel_sock_timeval *)optval = tv;
387 	return sizeof(tv);
388 }
389 EXPORT_SYMBOL(sock_get_timeout);
390 
sock_copy_user_timeval(struct __kernel_sock_timeval * tv,sockptr_t optval,int optlen,bool old_timeval)391 int sock_copy_user_timeval(struct __kernel_sock_timeval *tv,
392 			   sockptr_t optval, int optlen, bool old_timeval)
393 {
394 	if (old_timeval && in_compat_syscall() && !COMPAT_USE_64BIT_TIME) {
395 		struct old_timeval32 tv32;
396 
397 		if (optlen < sizeof(tv32))
398 			return -EINVAL;
399 
400 		if (copy_from_sockptr(&tv32, optval, sizeof(tv32)))
401 			return -EFAULT;
402 		tv->tv_sec = tv32.tv_sec;
403 		tv->tv_usec = tv32.tv_usec;
404 	} else if (old_timeval) {
405 		struct __kernel_old_timeval old_tv;
406 
407 		if (optlen < sizeof(old_tv))
408 			return -EINVAL;
409 		if (copy_from_sockptr(&old_tv, optval, sizeof(old_tv)))
410 			return -EFAULT;
411 		tv->tv_sec = old_tv.tv_sec;
412 		tv->tv_usec = old_tv.tv_usec;
413 	} else {
414 		if (optlen < sizeof(*tv))
415 			return -EINVAL;
416 		if (copy_from_sockptr(tv, optval, sizeof(*tv)))
417 			return -EFAULT;
418 	}
419 
420 	return 0;
421 }
422 EXPORT_SYMBOL(sock_copy_user_timeval);
423 
sock_set_timeout(long * timeo_p,sockptr_t optval,int optlen,bool old_timeval)424 static int sock_set_timeout(long *timeo_p, sockptr_t optval, int optlen,
425 			    bool old_timeval)
426 {
427 	struct __kernel_sock_timeval tv;
428 	int err = sock_copy_user_timeval(&tv, optval, optlen, old_timeval);
429 	long val;
430 
431 	if (err)
432 		return err;
433 
434 	if (tv.tv_usec < 0 || tv.tv_usec >= USEC_PER_SEC)
435 		return -EDOM;
436 
437 	if (tv.tv_sec < 0) {
438 		static int warned __read_mostly;
439 
440 		WRITE_ONCE(*timeo_p, 0);
441 		if (warned < 10 && net_ratelimit()) {
442 			warned++;
443 			pr_info("%s: `%s' (pid %d) tries to set negative timeout\n",
444 				__func__, current->comm, task_pid_nr(current));
445 		}
446 		return 0;
447 	}
448 	val = MAX_SCHEDULE_TIMEOUT;
449 	if ((tv.tv_sec || tv.tv_usec) &&
450 	    (tv.tv_sec < (MAX_SCHEDULE_TIMEOUT / HZ - 1)))
451 		val = tv.tv_sec * HZ + DIV_ROUND_UP((unsigned long)tv.tv_usec,
452 						    USEC_PER_SEC / HZ);
453 	WRITE_ONCE(*timeo_p, val);
454 	return 0;
455 }
456 
sock_needs_netstamp(const struct sock * sk)457 static bool sock_needs_netstamp(const struct sock *sk)
458 {
459 	switch (sk->sk_family) {
460 	case AF_UNSPEC:
461 	case AF_UNIX:
462 		return false;
463 	default:
464 		return true;
465 	}
466 }
467 
sock_disable_timestamp(struct sock * sk,unsigned long flags)468 static void sock_disable_timestamp(struct sock *sk, unsigned long flags)
469 {
470 	if (sk->sk_flags & flags) {
471 		sk->sk_flags &= ~flags;
472 		if (sock_needs_netstamp(sk) &&
473 		    !(sk->sk_flags & SK_FLAGS_TIMESTAMP))
474 			net_disable_timestamp();
475 	}
476 }
477 
478 
__sock_queue_rcv_skb(struct sock * sk,struct sk_buff * skb)479 int __sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
480 {
481 	unsigned long flags;
482 	struct sk_buff_head *list = &sk->sk_receive_queue;
483 
484 	if (atomic_read(&sk->sk_rmem_alloc) >= READ_ONCE(sk->sk_rcvbuf)) {
485 		atomic_inc(&sk->sk_drops);
486 		trace_sock_rcvqueue_full(sk, skb);
487 		return -ENOMEM;
488 	}
489 
490 	if (!sk_rmem_schedule(sk, skb, skb->truesize)) {
491 		atomic_inc(&sk->sk_drops);
492 		return -ENOBUFS;
493 	}
494 
495 	skb->dev = NULL;
496 	skb_set_owner_r(skb, sk);
497 
498 	/* we escape from rcu protected region, make sure we dont leak
499 	 * a norefcounted dst
500 	 */
501 	skb_dst_force(skb);
502 
503 	spin_lock_irqsave(&list->lock, flags);
504 	sock_skb_set_dropcount(sk, skb);
505 	__skb_queue_tail(list, skb);
506 	spin_unlock_irqrestore(&list->lock, flags);
507 
508 	if (!sock_flag(sk, SOCK_DEAD))
509 		sk->sk_data_ready(sk);
510 	return 0;
511 }
512 EXPORT_SYMBOL(__sock_queue_rcv_skb);
513 
sock_queue_rcv_skb_reason(struct sock * sk,struct sk_buff * skb,enum skb_drop_reason * reason)514 int sock_queue_rcv_skb_reason(struct sock *sk, struct sk_buff *skb,
515 			      enum skb_drop_reason *reason)
516 {
517 	enum skb_drop_reason drop_reason;
518 	int err;
519 
520 	err = sk_filter(sk, skb);
521 	if (err) {
522 		drop_reason = SKB_DROP_REASON_SOCKET_FILTER;
523 		goto out;
524 	}
525 	err = __sock_queue_rcv_skb(sk, skb);
526 	switch (err) {
527 	case -ENOMEM:
528 		drop_reason = SKB_DROP_REASON_SOCKET_RCVBUFF;
529 		break;
530 	case -ENOBUFS:
531 		drop_reason = SKB_DROP_REASON_PROTO_MEM;
532 		break;
533 	default:
534 		drop_reason = SKB_NOT_DROPPED_YET;
535 		break;
536 	}
537 out:
538 	if (reason)
539 		*reason = drop_reason;
540 	return err;
541 }
542 EXPORT_SYMBOL(sock_queue_rcv_skb_reason);
543 
__sk_receive_skb(struct sock * sk,struct sk_buff * skb,const int nested,unsigned int trim_cap,bool refcounted)544 int __sk_receive_skb(struct sock *sk, struct sk_buff *skb,
545 		     const int nested, unsigned int trim_cap, bool refcounted)
546 {
547 	int rc = NET_RX_SUCCESS;
548 
549 	if (sk_filter_trim_cap(sk, skb, trim_cap))
550 		goto discard_and_relse;
551 
552 	skb->dev = NULL;
553 
554 	if (sk_rcvqueues_full(sk, READ_ONCE(sk->sk_rcvbuf))) {
555 		atomic_inc(&sk->sk_drops);
556 		goto discard_and_relse;
557 	}
558 	if (nested)
559 		bh_lock_sock_nested(sk);
560 	else
561 		bh_lock_sock(sk);
562 	if (!sock_owned_by_user(sk)) {
563 		/*
564 		 * trylock + unlock semantics:
565 		 */
566 		mutex_acquire(&sk->sk_lock.dep_map, 0, 1, _RET_IP_);
567 
568 		rc = sk_backlog_rcv(sk, skb);
569 
570 		mutex_release(&sk->sk_lock.dep_map, _RET_IP_);
571 	} else if (sk_add_backlog(sk, skb, READ_ONCE(sk->sk_rcvbuf))) {
572 		bh_unlock_sock(sk);
573 		atomic_inc(&sk->sk_drops);
574 		goto discard_and_relse;
575 	}
576 
577 	bh_unlock_sock(sk);
578 out:
579 	if (refcounted)
580 		sock_put(sk);
581 	return rc;
582 discard_and_relse:
583 	kfree_skb(skb);
584 	goto out;
585 }
586 EXPORT_SYMBOL(__sk_receive_skb);
587 
588 INDIRECT_CALLABLE_DECLARE(struct dst_entry *ip6_dst_check(struct dst_entry *,
589 							  u32));
590 INDIRECT_CALLABLE_DECLARE(struct dst_entry *ipv4_dst_check(struct dst_entry *,
591 							   u32));
__sk_dst_check(struct sock * sk,u32 cookie)592 struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie)
593 {
594 	struct dst_entry *dst = __sk_dst_get(sk);
595 
596 	if (dst && dst->obsolete &&
597 	    INDIRECT_CALL_INET(dst->ops->check, ip6_dst_check, ipv4_dst_check,
598 			       dst, cookie) == NULL) {
599 		sk_tx_queue_clear(sk);
600 		WRITE_ONCE(sk->sk_dst_pending_confirm, 0);
601 		RCU_INIT_POINTER(sk->sk_dst_cache, NULL);
602 		dst_release(dst);
603 		return NULL;
604 	}
605 
606 	return dst;
607 }
608 EXPORT_SYMBOL(__sk_dst_check);
609 
sk_dst_check(struct sock * sk,u32 cookie)610 struct dst_entry *sk_dst_check(struct sock *sk, u32 cookie)
611 {
612 	struct dst_entry *dst = sk_dst_get(sk);
613 
614 	if (dst && dst->obsolete &&
615 	    INDIRECT_CALL_INET(dst->ops->check, ip6_dst_check, ipv4_dst_check,
616 			       dst, cookie) == NULL) {
617 		sk_dst_reset(sk);
618 		dst_release(dst);
619 		return NULL;
620 	}
621 
622 	return dst;
623 }
624 EXPORT_SYMBOL(sk_dst_check);
625 
sock_bindtoindex_locked(struct sock * sk,int ifindex)626 static int sock_bindtoindex_locked(struct sock *sk, int ifindex)
627 {
628 	int ret = -ENOPROTOOPT;
629 #ifdef CONFIG_NETDEVICES
630 	struct net *net = sock_net(sk);
631 
632 	/* Sorry... */
633 	ret = -EPERM;
634 	if (sk->sk_bound_dev_if && !ns_capable(net->user_ns, CAP_NET_RAW))
635 		goto out;
636 
637 	ret = -EINVAL;
638 	if (ifindex < 0)
639 		goto out;
640 
641 	/* Paired with all READ_ONCE() done locklessly. */
642 	WRITE_ONCE(sk->sk_bound_dev_if, ifindex);
643 
644 	if (sk->sk_prot->rehash)
645 		sk->sk_prot->rehash(sk);
646 	sk_dst_reset(sk);
647 
648 	ret = 0;
649 
650 out:
651 #endif
652 
653 	return ret;
654 }
655 
sock_bindtoindex(struct sock * sk,int ifindex,bool lock_sk)656 int sock_bindtoindex(struct sock *sk, int ifindex, bool lock_sk)
657 {
658 	int ret;
659 
660 	if (lock_sk)
661 		lock_sock(sk);
662 	ret = sock_bindtoindex_locked(sk, ifindex);
663 	if (lock_sk)
664 		release_sock(sk);
665 
666 	return ret;
667 }
668 EXPORT_SYMBOL(sock_bindtoindex);
669 
sock_setbindtodevice(struct sock * sk,sockptr_t optval,int optlen)670 static int sock_setbindtodevice(struct sock *sk, sockptr_t optval, int optlen)
671 {
672 	int ret = -ENOPROTOOPT;
673 #ifdef CONFIG_NETDEVICES
674 	struct net *net = sock_net(sk);
675 	char devname[IFNAMSIZ];
676 	int index;
677 
678 	ret = -EINVAL;
679 	if (optlen < 0)
680 		goto out;
681 
682 	/* Bind this socket to a particular device like "eth0",
683 	 * as specified in the passed interface name. If the
684 	 * name is "" or the option length is zero the socket
685 	 * is not bound.
686 	 */
687 	if (optlen > IFNAMSIZ - 1)
688 		optlen = IFNAMSIZ - 1;
689 	memset(devname, 0, sizeof(devname));
690 
691 	ret = -EFAULT;
692 	if (copy_from_sockptr(devname, optval, optlen))
693 		goto out;
694 
695 	index = 0;
696 	if (devname[0] != '\0') {
697 		struct net_device *dev;
698 
699 		rcu_read_lock();
700 		dev = dev_get_by_name_rcu(net, devname);
701 		if (dev)
702 			index = dev->ifindex;
703 		rcu_read_unlock();
704 		ret = -ENODEV;
705 		if (!dev)
706 			goto out;
707 	}
708 
709 	sockopt_lock_sock(sk);
710 	ret = sock_bindtoindex_locked(sk, index);
711 	sockopt_release_sock(sk);
712 out:
713 #endif
714 
715 	return ret;
716 }
717 
sock_getbindtodevice(struct sock * sk,sockptr_t optval,sockptr_t optlen,int len)718 static int sock_getbindtodevice(struct sock *sk, sockptr_t optval,
719 				sockptr_t optlen, int len)
720 {
721 	int ret = -ENOPROTOOPT;
722 #ifdef CONFIG_NETDEVICES
723 	int bound_dev_if = READ_ONCE(sk->sk_bound_dev_if);
724 	struct net *net = sock_net(sk);
725 	char devname[IFNAMSIZ];
726 
727 	if (bound_dev_if == 0) {
728 		len = 0;
729 		goto zero;
730 	}
731 
732 	ret = -EINVAL;
733 	if (len < IFNAMSIZ)
734 		goto out;
735 
736 	ret = netdev_get_name(net, devname, bound_dev_if);
737 	if (ret)
738 		goto out;
739 
740 	len = strlen(devname) + 1;
741 
742 	ret = -EFAULT;
743 	if (copy_to_sockptr(optval, devname, len))
744 		goto out;
745 
746 zero:
747 	ret = -EFAULT;
748 	if (copy_to_sockptr(optlen, &len, sizeof(int)))
749 		goto out;
750 
751 	ret = 0;
752 
753 out:
754 #endif
755 
756 	return ret;
757 }
758 
sk_mc_loop(const struct sock * sk)759 bool sk_mc_loop(const struct sock *sk)
760 {
761 	if (dev_recursion_level())
762 		return false;
763 	if (!sk)
764 		return true;
765 	/* IPV6_ADDRFORM can change sk->sk_family under us. */
766 	switch (READ_ONCE(sk->sk_family)) {
767 	case AF_INET:
768 		return inet_test_bit(MC_LOOP, sk);
769 #if IS_ENABLED(CONFIG_IPV6)
770 	case AF_INET6:
771 		return inet6_test_bit(MC6_LOOP, sk);
772 #endif
773 	}
774 	WARN_ON_ONCE(1);
775 	return true;
776 }
777 EXPORT_SYMBOL(sk_mc_loop);
778 
sock_set_reuseaddr(struct sock * sk)779 void sock_set_reuseaddr(struct sock *sk)
780 {
781 	lock_sock(sk);
782 	sk->sk_reuse = SK_CAN_REUSE;
783 	release_sock(sk);
784 }
785 EXPORT_SYMBOL(sock_set_reuseaddr);
786 
sock_set_reuseport(struct sock * sk)787 void sock_set_reuseport(struct sock *sk)
788 {
789 	lock_sock(sk);
790 	sk->sk_reuseport = true;
791 	release_sock(sk);
792 }
793 EXPORT_SYMBOL(sock_set_reuseport);
794 
sock_no_linger(struct sock * sk)795 void sock_no_linger(struct sock *sk)
796 {
797 	lock_sock(sk);
798 	WRITE_ONCE(sk->sk_lingertime, 0);
799 	sock_set_flag(sk, SOCK_LINGER);
800 	release_sock(sk);
801 }
802 EXPORT_SYMBOL(sock_no_linger);
803 
sock_set_priority(struct sock * sk,u32 priority)804 void sock_set_priority(struct sock *sk, u32 priority)
805 {
806 	WRITE_ONCE(sk->sk_priority, priority);
807 }
808 EXPORT_SYMBOL(sock_set_priority);
809 
sock_set_sndtimeo(struct sock * sk,s64 secs)810 void sock_set_sndtimeo(struct sock *sk, s64 secs)
811 {
812 	lock_sock(sk);
813 	if (secs && secs < MAX_SCHEDULE_TIMEOUT / HZ - 1)
814 		WRITE_ONCE(sk->sk_sndtimeo, secs * HZ);
815 	else
816 		WRITE_ONCE(sk->sk_sndtimeo, MAX_SCHEDULE_TIMEOUT);
817 	release_sock(sk);
818 }
819 EXPORT_SYMBOL(sock_set_sndtimeo);
820 
__sock_set_timestamps(struct sock * sk,bool val,bool new,bool ns)821 static void __sock_set_timestamps(struct sock *sk, bool val, bool new, bool ns)
822 {
823 	sock_valbool_flag(sk, SOCK_RCVTSTAMP, val);
824 	sock_valbool_flag(sk, SOCK_RCVTSTAMPNS, val && ns);
825 	if (val)  {
826 		sock_valbool_flag(sk, SOCK_TSTAMP_NEW, new);
827 		sock_enable_timestamp(sk, SOCK_TIMESTAMP);
828 	}
829 }
830 
sock_enable_timestamps(struct sock * sk)831 void sock_enable_timestamps(struct sock *sk)
832 {
833 	lock_sock(sk);
834 	__sock_set_timestamps(sk, true, false, true);
835 	release_sock(sk);
836 }
837 EXPORT_SYMBOL(sock_enable_timestamps);
838 
sock_set_timestamp(struct sock * sk,int optname,bool valbool)839 void sock_set_timestamp(struct sock *sk, int optname, bool valbool)
840 {
841 	switch (optname) {
842 	case SO_TIMESTAMP_OLD:
843 		__sock_set_timestamps(sk, valbool, false, false);
844 		break;
845 	case SO_TIMESTAMP_NEW:
846 		__sock_set_timestamps(sk, valbool, true, false);
847 		break;
848 	case SO_TIMESTAMPNS_OLD:
849 		__sock_set_timestamps(sk, valbool, false, true);
850 		break;
851 	case SO_TIMESTAMPNS_NEW:
852 		__sock_set_timestamps(sk, valbool, true, true);
853 		break;
854 	}
855 }
856 
sock_timestamping_bind_phc(struct sock * sk,int phc_index)857 static int sock_timestamping_bind_phc(struct sock *sk, int phc_index)
858 {
859 	struct net *net = sock_net(sk);
860 	struct net_device *dev = NULL;
861 	bool match = false;
862 	int *vclock_index;
863 	int i, num;
864 
865 	if (sk->sk_bound_dev_if)
866 		dev = dev_get_by_index(net, sk->sk_bound_dev_if);
867 
868 	if (!dev) {
869 		pr_err("%s: sock not bind to device\n", __func__);
870 		return -EOPNOTSUPP;
871 	}
872 
873 	num = ethtool_get_phc_vclocks(dev, &vclock_index);
874 	dev_put(dev);
875 
876 	for (i = 0; i < num; i++) {
877 		if (*(vclock_index + i) == phc_index) {
878 			match = true;
879 			break;
880 		}
881 	}
882 
883 	if (num > 0)
884 		kfree(vclock_index);
885 
886 	if (!match)
887 		return -EINVAL;
888 
889 	WRITE_ONCE(sk->sk_bind_phc, phc_index);
890 
891 	return 0;
892 }
893 
sock_set_timestamping(struct sock * sk,int optname,struct so_timestamping timestamping)894 int sock_set_timestamping(struct sock *sk, int optname,
895 			  struct so_timestamping timestamping)
896 {
897 	int val = timestamping.flags;
898 	int ret;
899 
900 	if (val & ~SOF_TIMESTAMPING_MASK)
901 		return -EINVAL;
902 
903 	if (val & SOF_TIMESTAMPING_OPT_ID_TCP &&
904 	    !(val & SOF_TIMESTAMPING_OPT_ID))
905 		return -EINVAL;
906 
907 	if (val & SOF_TIMESTAMPING_OPT_ID &&
908 	    !(sk->sk_tsflags & SOF_TIMESTAMPING_OPT_ID)) {
909 		if (sk_is_tcp(sk)) {
910 			if ((1 << sk->sk_state) &
911 			    (TCPF_CLOSE | TCPF_LISTEN))
912 				return -EINVAL;
913 			if (val & SOF_TIMESTAMPING_OPT_ID_TCP)
914 				atomic_set(&sk->sk_tskey, tcp_sk(sk)->write_seq);
915 			else
916 				atomic_set(&sk->sk_tskey, tcp_sk(sk)->snd_una);
917 		} else {
918 			atomic_set(&sk->sk_tskey, 0);
919 		}
920 	}
921 
922 	if (val & SOF_TIMESTAMPING_OPT_STATS &&
923 	    !(val & SOF_TIMESTAMPING_OPT_TSONLY))
924 		return -EINVAL;
925 
926 	if (val & SOF_TIMESTAMPING_BIND_PHC) {
927 		ret = sock_timestamping_bind_phc(sk, timestamping.bind_phc);
928 		if (ret)
929 			return ret;
930 	}
931 
932 	WRITE_ONCE(sk->sk_tsflags, val);
933 	sock_valbool_flag(sk, SOCK_TSTAMP_NEW, optname == SO_TIMESTAMPING_NEW);
934 
935 	if (val & SOF_TIMESTAMPING_RX_SOFTWARE)
936 		sock_enable_timestamp(sk,
937 				      SOCK_TIMESTAMPING_RX_SOFTWARE);
938 	else
939 		sock_disable_timestamp(sk,
940 				       (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE));
941 	return 0;
942 }
943 
sock_set_keepalive(struct sock * sk)944 void sock_set_keepalive(struct sock *sk)
945 {
946 	lock_sock(sk);
947 	if (sk->sk_prot->keepalive)
948 		sk->sk_prot->keepalive(sk, true);
949 	sock_valbool_flag(sk, SOCK_KEEPOPEN, true);
950 	release_sock(sk);
951 }
952 EXPORT_SYMBOL(sock_set_keepalive);
953 
__sock_set_rcvbuf(struct sock * sk,int val)954 static void __sock_set_rcvbuf(struct sock *sk, int val)
955 {
956 	/* Ensure val * 2 fits into an int, to prevent max_t() from treating it
957 	 * as a negative value.
958 	 */
959 	val = min_t(int, val, INT_MAX / 2);
960 	sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
961 
962 	/* We double it on the way in to account for "struct sk_buff" etc.
963 	 * overhead.   Applications assume that the SO_RCVBUF setting they make
964 	 * will allow that much actual data to be received on that socket.
965 	 *
966 	 * Applications are unaware that "struct sk_buff" and other overheads
967 	 * allocate from the receive buffer during socket buffer allocation.
968 	 *
969 	 * And after considering the possible alternatives, returning the value
970 	 * we actually used in getsockopt is the most desirable behavior.
971 	 */
972 	WRITE_ONCE(sk->sk_rcvbuf, max_t(int, val * 2, SOCK_MIN_RCVBUF));
973 }
974 
sock_set_rcvbuf(struct sock * sk,int val)975 void sock_set_rcvbuf(struct sock *sk, int val)
976 {
977 	lock_sock(sk);
978 	__sock_set_rcvbuf(sk, val);
979 	release_sock(sk);
980 }
981 EXPORT_SYMBOL(sock_set_rcvbuf);
982 
__sock_set_mark(struct sock * sk,u32 val)983 static void __sock_set_mark(struct sock *sk, u32 val)
984 {
985 	if (val != sk->sk_mark) {
986 		WRITE_ONCE(sk->sk_mark, val);
987 		sk_dst_reset(sk);
988 	}
989 }
990 
sock_set_mark(struct sock * sk,u32 val)991 void sock_set_mark(struct sock *sk, u32 val)
992 {
993 	lock_sock(sk);
994 	__sock_set_mark(sk, val);
995 	release_sock(sk);
996 }
997 EXPORT_SYMBOL(sock_set_mark);
998 
sock_release_reserved_memory(struct sock * sk,int bytes)999 static void sock_release_reserved_memory(struct sock *sk, int bytes)
1000 {
1001 	/* Round down bytes to multiple of pages */
1002 	bytes = round_down(bytes, PAGE_SIZE);
1003 
1004 	WARN_ON(bytes > sk->sk_reserved_mem);
1005 	WRITE_ONCE(sk->sk_reserved_mem, sk->sk_reserved_mem - bytes);
1006 	sk_mem_reclaim(sk);
1007 }
1008 
sock_reserve_memory(struct sock * sk,int bytes)1009 static int sock_reserve_memory(struct sock *sk, int bytes)
1010 {
1011 	long allocated;
1012 	bool charged;
1013 	int pages;
1014 
1015 	if (!mem_cgroup_sockets_enabled || !sk->sk_memcg || !sk_has_account(sk))
1016 		return -EOPNOTSUPP;
1017 
1018 	if (!bytes)
1019 		return 0;
1020 
1021 	pages = sk_mem_pages(bytes);
1022 
1023 	/* pre-charge to memcg */
1024 	charged = mem_cgroup_charge_skmem(sk->sk_memcg, pages,
1025 					  GFP_KERNEL | __GFP_RETRY_MAYFAIL);
1026 	if (!charged)
1027 		return -ENOMEM;
1028 
1029 	/* pre-charge to forward_alloc */
1030 	sk_memory_allocated_add(sk, pages);
1031 	allocated = sk_memory_allocated(sk);
1032 	/* If the system goes into memory pressure with this
1033 	 * precharge, give up and return error.
1034 	 */
1035 	if (allocated > sk_prot_mem_limits(sk, 1)) {
1036 		sk_memory_allocated_sub(sk, pages);
1037 		mem_cgroup_uncharge_skmem(sk->sk_memcg, pages);
1038 		return -ENOMEM;
1039 	}
1040 	sk_forward_alloc_add(sk, pages << PAGE_SHIFT);
1041 
1042 	WRITE_ONCE(sk->sk_reserved_mem,
1043 		   sk->sk_reserved_mem + (pages << PAGE_SHIFT));
1044 
1045 	return 0;
1046 }
1047 
1048 #ifdef CONFIG_PAGE_POOL
1049 
1050 /* This is the number of tokens and frags that the user can SO_DEVMEM_DONTNEED
1051  * in 1 syscall. The limit exists to limit the amount of memory the kernel
1052  * allocates to copy these tokens, and to prevent looping over the frags for
1053  * too long.
1054  */
1055 #define MAX_DONTNEED_TOKENS 128
1056 #define MAX_DONTNEED_FRAGS 1024
1057 
1058 static noinline_for_stack int
sock_devmem_dontneed(struct sock * sk,sockptr_t optval,unsigned int optlen)1059 sock_devmem_dontneed(struct sock *sk, sockptr_t optval, unsigned int optlen)
1060 {
1061 	unsigned int num_tokens, i, j, k, netmem_num = 0;
1062 	struct dmabuf_token *tokens;
1063 	int ret = 0, num_frags = 0;
1064 	netmem_ref netmems[16];
1065 
1066 	if (!sk_is_tcp(sk))
1067 		return -EBADF;
1068 
1069 	if (optlen % sizeof(*tokens) ||
1070 	    optlen > sizeof(*tokens) * MAX_DONTNEED_TOKENS)
1071 		return -EINVAL;
1072 
1073 	num_tokens = optlen / sizeof(*tokens);
1074 	tokens = kvmalloc_array(num_tokens, sizeof(*tokens), GFP_KERNEL);
1075 	if (!tokens)
1076 		return -ENOMEM;
1077 
1078 	if (copy_from_sockptr(tokens, optval, optlen)) {
1079 		kvfree(tokens);
1080 		return -EFAULT;
1081 	}
1082 
1083 	xa_lock_bh(&sk->sk_user_frags);
1084 	for (i = 0; i < num_tokens; i++) {
1085 		for (j = 0; j < tokens[i].token_count; j++) {
1086 			if (++num_frags > MAX_DONTNEED_FRAGS)
1087 				goto frag_limit_reached;
1088 
1089 			netmem_ref netmem = (__force netmem_ref)__xa_erase(
1090 				&sk->sk_user_frags, tokens[i].token_start + j);
1091 
1092 			if (!netmem || WARN_ON_ONCE(!netmem_is_net_iov(netmem)))
1093 				continue;
1094 
1095 			netmems[netmem_num++] = netmem;
1096 			if (netmem_num == ARRAY_SIZE(netmems)) {
1097 				xa_unlock_bh(&sk->sk_user_frags);
1098 				for (k = 0; k < netmem_num; k++)
1099 					WARN_ON_ONCE(!napi_pp_put_page(netmems[k]));
1100 				netmem_num = 0;
1101 				xa_lock_bh(&sk->sk_user_frags);
1102 			}
1103 			ret++;
1104 		}
1105 	}
1106 
1107 frag_limit_reached:
1108 	xa_unlock_bh(&sk->sk_user_frags);
1109 	for (k = 0; k < netmem_num; k++)
1110 		WARN_ON_ONCE(!napi_pp_put_page(netmems[k]));
1111 
1112 	kvfree(tokens);
1113 	return ret;
1114 }
1115 #endif
1116 
sockopt_lock_sock(struct sock * sk)1117 void sockopt_lock_sock(struct sock *sk)
1118 {
1119 	/* When current->bpf_ctx is set, the setsockopt is called from
1120 	 * a bpf prog.  bpf has ensured the sk lock has been
1121 	 * acquired before calling setsockopt().
1122 	 */
1123 	if (has_current_bpf_ctx())
1124 		return;
1125 
1126 	lock_sock(sk);
1127 }
1128 EXPORT_SYMBOL(sockopt_lock_sock);
1129 
sockopt_release_sock(struct sock * sk)1130 void sockopt_release_sock(struct sock *sk)
1131 {
1132 	if (has_current_bpf_ctx())
1133 		return;
1134 
1135 	release_sock(sk);
1136 }
1137 EXPORT_SYMBOL(sockopt_release_sock);
1138 
sockopt_ns_capable(struct user_namespace * ns,int cap)1139 bool sockopt_ns_capable(struct user_namespace *ns, int cap)
1140 {
1141 	return has_current_bpf_ctx() || ns_capable(ns, cap);
1142 }
1143 EXPORT_SYMBOL(sockopt_ns_capable);
1144 
sockopt_capable(int cap)1145 bool sockopt_capable(int cap)
1146 {
1147 	return has_current_bpf_ctx() || capable(cap);
1148 }
1149 EXPORT_SYMBOL(sockopt_capable);
1150 
sockopt_validate_clockid(__kernel_clockid_t value)1151 static int sockopt_validate_clockid(__kernel_clockid_t value)
1152 {
1153 	switch (value) {
1154 	case CLOCK_REALTIME:
1155 	case CLOCK_MONOTONIC:
1156 	case CLOCK_TAI:
1157 		return 0;
1158 	}
1159 	return -EINVAL;
1160 }
1161 
1162 /*
1163  *	This is meant for all protocols to use and covers goings on
1164  *	at the socket level. Everything here is generic.
1165  */
1166 
sk_setsockopt(struct sock * sk,int level,int optname,sockptr_t optval,unsigned int optlen)1167 int sk_setsockopt(struct sock *sk, int level, int optname,
1168 		  sockptr_t optval, unsigned int optlen)
1169 {
1170 	struct so_timestamping timestamping;
1171 	struct socket *sock = sk->sk_socket;
1172 	struct sock_txtime sk_txtime;
1173 	int val;
1174 	int valbool;
1175 	struct linger ling;
1176 	int ret = 0;
1177 
1178 	/*
1179 	 *	Options without arguments
1180 	 */
1181 
1182 	if (optname == SO_BINDTODEVICE)
1183 		return sock_setbindtodevice(sk, optval, optlen);
1184 
1185 	if (optlen < sizeof(int))
1186 		return -EINVAL;
1187 
1188 	if (copy_from_sockptr(&val, optval, sizeof(val)))
1189 		return -EFAULT;
1190 
1191 	valbool = val ? 1 : 0;
1192 
1193 	/* handle options which do not require locking the socket. */
1194 	switch (optname) {
1195 	case SO_PRIORITY:
1196 		if ((val >= 0 && val <= 6) ||
1197 		    sockopt_ns_capable(sock_net(sk)->user_ns, CAP_NET_RAW) ||
1198 		    sockopt_ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) {
1199 			sock_set_priority(sk, val);
1200 			return 0;
1201 		}
1202 		return -EPERM;
1203 	case SO_PASSSEC:
1204 		assign_bit(SOCK_PASSSEC, &sock->flags, valbool);
1205 		return 0;
1206 	case SO_PASSCRED:
1207 		assign_bit(SOCK_PASSCRED, &sock->flags, valbool);
1208 		return 0;
1209 	case SO_PASSPIDFD:
1210 		assign_bit(SOCK_PASSPIDFD, &sock->flags, valbool);
1211 		return 0;
1212 	case SO_TYPE:
1213 	case SO_PROTOCOL:
1214 	case SO_DOMAIN:
1215 	case SO_ERROR:
1216 		return -ENOPROTOOPT;
1217 #ifdef CONFIG_NET_RX_BUSY_POLL
1218 	case SO_BUSY_POLL:
1219 		if (val < 0)
1220 			return -EINVAL;
1221 		WRITE_ONCE(sk->sk_ll_usec, val);
1222 		return 0;
1223 	case SO_PREFER_BUSY_POLL:
1224 		if (valbool && !sockopt_capable(CAP_NET_ADMIN))
1225 			return -EPERM;
1226 		WRITE_ONCE(sk->sk_prefer_busy_poll, valbool);
1227 		return 0;
1228 	case SO_BUSY_POLL_BUDGET:
1229 		if (val > READ_ONCE(sk->sk_busy_poll_budget) &&
1230 		    !sockopt_capable(CAP_NET_ADMIN))
1231 			return -EPERM;
1232 		if (val < 0 || val > U16_MAX)
1233 			return -EINVAL;
1234 		WRITE_ONCE(sk->sk_busy_poll_budget, val);
1235 		return 0;
1236 #endif
1237 	case SO_MAX_PACING_RATE:
1238 		{
1239 		unsigned long ulval = (val == ~0U) ? ~0UL : (unsigned int)val;
1240 		unsigned long pacing_rate;
1241 
1242 		if (sizeof(ulval) != sizeof(val) &&
1243 		    optlen >= sizeof(ulval) &&
1244 		    copy_from_sockptr(&ulval, optval, sizeof(ulval))) {
1245 			return -EFAULT;
1246 		}
1247 		if (ulval != ~0UL)
1248 			cmpxchg(&sk->sk_pacing_status,
1249 				SK_PACING_NONE,
1250 				SK_PACING_NEEDED);
1251 		/* Pairs with READ_ONCE() from sk_getsockopt() */
1252 		WRITE_ONCE(sk->sk_max_pacing_rate, ulval);
1253 		pacing_rate = READ_ONCE(sk->sk_pacing_rate);
1254 		if (ulval < pacing_rate)
1255 			WRITE_ONCE(sk->sk_pacing_rate, ulval);
1256 		return 0;
1257 		}
1258 	case SO_TXREHASH:
1259 		if (val < -1 || val > 1)
1260 			return -EINVAL;
1261 		if ((u8)val == SOCK_TXREHASH_DEFAULT)
1262 			val = READ_ONCE(sock_net(sk)->core.sysctl_txrehash);
1263 		/* Paired with READ_ONCE() in tcp_rtx_synack()
1264 		 * and sk_getsockopt().
1265 		 */
1266 		WRITE_ONCE(sk->sk_txrehash, (u8)val);
1267 		return 0;
1268 	case SO_PEEK_OFF:
1269 		{
1270 		int (*set_peek_off)(struct sock *sk, int val);
1271 
1272 		set_peek_off = READ_ONCE(sock->ops)->set_peek_off;
1273 		if (set_peek_off)
1274 			ret = set_peek_off(sk, val);
1275 		else
1276 			ret = -EOPNOTSUPP;
1277 		return ret;
1278 		}
1279 #ifdef CONFIG_PAGE_POOL
1280 	case SO_DEVMEM_DONTNEED:
1281 		return sock_devmem_dontneed(sk, optval, optlen);
1282 #endif
1283 	}
1284 
1285 	sockopt_lock_sock(sk);
1286 
1287 	switch (optname) {
1288 	case SO_DEBUG:
1289 		if (val && !sockopt_capable(CAP_NET_ADMIN))
1290 			ret = -EACCES;
1291 		else
1292 			sock_valbool_flag(sk, SOCK_DBG, valbool);
1293 		break;
1294 	case SO_REUSEADDR:
1295 		sk->sk_reuse = (valbool ? SK_CAN_REUSE : SK_NO_REUSE);
1296 		break;
1297 	case SO_REUSEPORT:
1298 		sk->sk_reuseport = valbool;
1299 		break;
1300 	case SO_DONTROUTE:
1301 		sock_valbool_flag(sk, SOCK_LOCALROUTE, valbool);
1302 		sk_dst_reset(sk);
1303 		break;
1304 	case SO_BROADCAST:
1305 		sock_valbool_flag(sk, SOCK_BROADCAST, valbool);
1306 		break;
1307 	case SO_SNDBUF:
1308 		/* Don't error on this BSD doesn't and if you think
1309 		 * about it this is right. Otherwise apps have to
1310 		 * play 'guess the biggest size' games. RCVBUF/SNDBUF
1311 		 * are treated in BSD as hints
1312 		 */
1313 		val = min_t(u32, val, READ_ONCE(sysctl_wmem_max));
1314 set_sndbuf:
1315 		/* Ensure val * 2 fits into an int, to prevent max_t()
1316 		 * from treating it as a negative value.
1317 		 */
1318 		val = min_t(int, val, INT_MAX / 2);
1319 		sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
1320 		WRITE_ONCE(sk->sk_sndbuf,
1321 			   max_t(int, val * 2, SOCK_MIN_SNDBUF));
1322 		/* Wake up sending tasks if we upped the value. */
1323 		sk->sk_write_space(sk);
1324 		break;
1325 
1326 	case SO_SNDBUFFORCE:
1327 		if (!sockopt_capable(CAP_NET_ADMIN)) {
1328 			ret = -EPERM;
1329 			break;
1330 		}
1331 
1332 		/* No negative values (to prevent underflow, as val will be
1333 		 * multiplied by 2).
1334 		 */
1335 		if (val < 0)
1336 			val = 0;
1337 		goto set_sndbuf;
1338 
1339 	case SO_RCVBUF:
1340 		/* Don't error on this BSD doesn't and if you think
1341 		 * about it this is right. Otherwise apps have to
1342 		 * play 'guess the biggest size' games. RCVBUF/SNDBUF
1343 		 * are treated in BSD as hints
1344 		 */
1345 		__sock_set_rcvbuf(sk, min_t(u32, val, READ_ONCE(sysctl_rmem_max)));
1346 		break;
1347 
1348 	case SO_RCVBUFFORCE:
1349 		if (!sockopt_capable(CAP_NET_ADMIN)) {
1350 			ret = -EPERM;
1351 			break;
1352 		}
1353 
1354 		/* No negative values (to prevent underflow, as val will be
1355 		 * multiplied by 2).
1356 		 */
1357 		__sock_set_rcvbuf(sk, max(val, 0));
1358 		break;
1359 
1360 	case SO_KEEPALIVE:
1361 		if (sk->sk_prot->keepalive)
1362 			sk->sk_prot->keepalive(sk, valbool);
1363 		sock_valbool_flag(sk, SOCK_KEEPOPEN, valbool);
1364 		break;
1365 
1366 	case SO_OOBINLINE:
1367 		sock_valbool_flag(sk, SOCK_URGINLINE, valbool);
1368 		break;
1369 
1370 	case SO_NO_CHECK:
1371 		sk->sk_no_check_tx = valbool;
1372 		break;
1373 
1374 	case SO_LINGER:
1375 		if (optlen < sizeof(ling)) {
1376 			ret = -EINVAL;	/* 1003.1g */
1377 			break;
1378 		}
1379 		if (copy_from_sockptr(&ling, optval, sizeof(ling))) {
1380 			ret = -EFAULT;
1381 			break;
1382 		}
1383 		if (!ling.l_onoff) {
1384 			sock_reset_flag(sk, SOCK_LINGER);
1385 		} else {
1386 			unsigned long t_sec = ling.l_linger;
1387 
1388 			if (t_sec >= MAX_SCHEDULE_TIMEOUT / HZ)
1389 				WRITE_ONCE(sk->sk_lingertime, MAX_SCHEDULE_TIMEOUT);
1390 			else
1391 				WRITE_ONCE(sk->sk_lingertime, t_sec * HZ);
1392 			sock_set_flag(sk, SOCK_LINGER);
1393 		}
1394 		break;
1395 
1396 	case SO_BSDCOMPAT:
1397 		break;
1398 
1399 	case SO_TIMESTAMP_OLD:
1400 	case SO_TIMESTAMP_NEW:
1401 	case SO_TIMESTAMPNS_OLD:
1402 	case SO_TIMESTAMPNS_NEW:
1403 		sock_set_timestamp(sk, optname, valbool);
1404 		break;
1405 
1406 	case SO_TIMESTAMPING_NEW:
1407 	case SO_TIMESTAMPING_OLD:
1408 		if (optlen == sizeof(timestamping)) {
1409 			if (copy_from_sockptr(&timestamping, optval,
1410 					      sizeof(timestamping))) {
1411 				ret = -EFAULT;
1412 				break;
1413 			}
1414 		} else {
1415 			memset(&timestamping, 0, sizeof(timestamping));
1416 			timestamping.flags = val;
1417 		}
1418 		ret = sock_set_timestamping(sk, optname, timestamping);
1419 		break;
1420 
1421 	case SO_RCVLOWAT:
1422 		{
1423 		int (*set_rcvlowat)(struct sock *sk, int val) = NULL;
1424 
1425 		if (val < 0)
1426 			val = INT_MAX;
1427 		if (sock)
1428 			set_rcvlowat = READ_ONCE(sock->ops)->set_rcvlowat;
1429 		if (set_rcvlowat)
1430 			ret = set_rcvlowat(sk, val);
1431 		else
1432 			WRITE_ONCE(sk->sk_rcvlowat, val ? : 1);
1433 		break;
1434 		}
1435 	case SO_RCVTIMEO_OLD:
1436 	case SO_RCVTIMEO_NEW:
1437 		ret = sock_set_timeout(&sk->sk_rcvtimeo, optval,
1438 				       optlen, optname == SO_RCVTIMEO_OLD);
1439 		break;
1440 
1441 	case SO_SNDTIMEO_OLD:
1442 	case SO_SNDTIMEO_NEW:
1443 		ret = sock_set_timeout(&sk->sk_sndtimeo, optval,
1444 				       optlen, optname == SO_SNDTIMEO_OLD);
1445 		break;
1446 
1447 	case SO_ATTACH_FILTER: {
1448 		struct sock_fprog fprog;
1449 
1450 		ret = copy_bpf_fprog_from_user(&fprog, optval, optlen);
1451 		if (!ret)
1452 			ret = sk_attach_filter(&fprog, sk);
1453 		break;
1454 	}
1455 	case SO_ATTACH_BPF:
1456 		ret = -EINVAL;
1457 		if (optlen == sizeof(u32)) {
1458 			u32 ufd;
1459 
1460 			ret = -EFAULT;
1461 			if (copy_from_sockptr(&ufd, optval, sizeof(ufd)))
1462 				break;
1463 
1464 			ret = sk_attach_bpf(ufd, sk);
1465 		}
1466 		break;
1467 
1468 	case SO_ATTACH_REUSEPORT_CBPF: {
1469 		struct sock_fprog fprog;
1470 
1471 		ret = copy_bpf_fprog_from_user(&fprog, optval, optlen);
1472 		if (!ret)
1473 			ret = sk_reuseport_attach_filter(&fprog, sk);
1474 		break;
1475 	}
1476 	case SO_ATTACH_REUSEPORT_EBPF:
1477 		ret = -EINVAL;
1478 		if (optlen == sizeof(u32)) {
1479 			u32 ufd;
1480 
1481 			ret = -EFAULT;
1482 			if (copy_from_sockptr(&ufd, optval, sizeof(ufd)))
1483 				break;
1484 
1485 			ret = sk_reuseport_attach_bpf(ufd, sk);
1486 		}
1487 		break;
1488 
1489 	case SO_DETACH_REUSEPORT_BPF:
1490 		ret = reuseport_detach_prog(sk);
1491 		break;
1492 
1493 	case SO_DETACH_FILTER:
1494 		ret = sk_detach_filter(sk);
1495 		break;
1496 
1497 	case SO_LOCK_FILTER:
1498 		if (sock_flag(sk, SOCK_FILTER_LOCKED) && !valbool)
1499 			ret = -EPERM;
1500 		else
1501 			sock_valbool_flag(sk, SOCK_FILTER_LOCKED, valbool);
1502 		break;
1503 
1504 	case SO_MARK:
1505 		if (!sockopt_ns_capable(sock_net(sk)->user_ns, CAP_NET_RAW) &&
1506 		    !sockopt_ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) {
1507 			ret = -EPERM;
1508 			break;
1509 		}
1510 
1511 		__sock_set_mark(sk, val);
1512 		break;
1513 	case SO_RCVMARK:
1514 		sock_valbool_flag(sk, SOCK_RCVMARK, valbool);
1515 		break;
1516 
1517 	case SO_RXQ_OVFL:
1518 		sock_valbool_flag(sk, SOCK_RXQ_OVFL, valbool);
1519 		break;
1520 
1521 	case SO_WIFI_STATUS:
1522 		sock_valbool_flag(sk, SOCK_WIFI_STATUS, valbool);
1523 		break;
1524 
1525 	case SO_NOFCS:
1526 		sock_valbool_flag(sk, SOCK_NOFCS, valbool);
1527 		break;
1528 
1529 	case SO_SELECT_ERR_QUEUE:
1530 		sock_valbool_flag(sk, SOCK_SELECT_ERR_QUEUE, valbool);
1531 		break;
1532 
1533 
1534 	case SO_INCOMING_CPU:
1535 		reuseport_update_incoming_cpu(sk, val);
1536 		break;
1537 
1538 	case SO_CNX_ADVICE:
1539 		if (val == 1)
1540 			dst_negative_advice(sk);
1541 		break;
1542 
1543 	case SO_ZEROCOPY:
1544 		if (sk->sk_family == PF_INET || sk->sk_family == PF_INET6) {
1545 			if (!(sk_is_tcp(sk) ||
1546 			      (sk->sk_type == SOCK_DGRAM &&
1547 			       sk->sk_protocol == IPPROTO_UDP)))
1548 				ret = -EOPNOTSUPP;
1549 		} else if (sk->sk_family != PF_RDS) {
1550 			ret = -EOPNOTSUPP;
1551 		}
1552 		if (!ret) {
1553 			if (val < 0 || val > 1)
1554 				ret = -EINVAL;
1555 			else
1556 				sock_valbool_flag(sk, SOCK_ZEROCOPY, valbool);
1557 		}
1558 		break;
1559 
1560 	case SO_TXTIME:
1561 		if (optlen != sizeof(struct sock_txtime)) {
1562 			ret = -EINVAL;
1563 			break;
1564 		} else if (copy_from_sockptr(&sk_txtime, optval,
1565 			   sizeof(struct sock_txtime))) {
1566 			ret = -EFAULT;
1567 			break;
1568 		} else if (sk_txtime.flags & ~SOF_TXTIME_FLAGS_MASK) {
1569 			ret = -EINVAL;
1570 			break;
1571 		}
1572 		/* CLOCK_MONOTONIC is only used by sch_fq, and this packet
1573 		 * scheduler has enough safe guards.
1574 		 */
1575 		if (sk_txtime.clockid != CLOCK_MONOTONIC &&
1576 		    !sockopt_ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) {
1577 			ret = -EPERM;
1578 			break;
1579 		}
1580 
1581 		ret = sockopt_validate_clockid(sk_txtime.clockid);
1582 		if (ret)
1583 			break;
1584 
1585 		sock_valbool_flag(sk, SOCK_TXTIME, true);
1586 		sk->sk_clockid = sk_txtime.clockid;
1587 		sk->sk_txtime_deadline_mode =
1588 			!!(sk_txtime.flags & SOF_TXTIME_DEADLINE_MODE);
1589 		sk->sk_txtime_report_errors =
1590 			!!(sk_txtime.flags & SOF_TXTIME_REPORT_ERRORS);
1591 		break;
1592 
1593 	case SO_BINDTOIFINDEX:
1594 		ret = sock_bindtoindex_locked(sk, val);
1595 		break;
1596 
1597 	case SO_BUF_LOCK:
1598 		if (val & ~SOCK_BUF_LOCK_MASK) {
1599 			ret = -EINVAL;
1600 			break;
1601 		}
1602 		sk->sk_userlocks = val | (sk->sk_userlocks &
1603 					  ~SOCK_BUF_LOCK_MASK);
1604 		break;
1605 
1606 	case SO_RESERVE_MEM:
1607 	{
1608 		int delta;
1609 
1610 		if (val < 0) {
1611 			ret = -EINVAL;
1612 			break;
1613 		}
1614 
1615 		delta = val - sk->sk_reserved_mem;
1616 		if (delta < 0)
1617 			sock_release_reserved_memory(sk, -delta);
1618 		else
1619 			ret = sock_reserve_memory(sk, delta);
1620 		break;
1621 	}
1622 
1623 	default:
1624 		ret = -ENOPROTOOPT;
1625 		break;
1626 	}
1627 	sockopt_release_sock(sk);
1628 	return ret;
1629 }
1630 
sock_setsockopt(struct socket * sock,int level,int optname,sockptr_t optval,unsigned int optlen)1631 int sock_setsockopt(struct socket *sock, int level, int optname,
1632 		    sockptr_t optval, unsigned int optlen)
1633 {
1634 	return sk_setsockopt(sock->sk, level, optname,
1635 			     optval, optlen);
1636 }
1637 EXPORT_SYMBOL(sock_setsockopt);
1638 
sk_get_peer_cred(struct sock * sk)1639 static const struct cred *sk_get_peer_cred(struct sock *sk)
1640 {
1641 	const struct cred *cred;
1642 
1643 	spin_lock(&sk->sk_peer_lock);
1644 	cred = get_cred(sk->sk_peer_cred);
1645 	spin_unlock(&sk->sk_peer_lock);
1646 
1647 	return cred;
1648 }
1649 
cred_to_ucred(struct pid * pid,const struct cred * cred,struct ucred * ucred)1650 static void cred_to_ucred(struct pid *pid, const struct cred *cred,
1651 			  struct ucred *ucred)
1652 {
1653 	ucred->pid = pid_vnr(pid);
1654 	ucred->uid = ucred->gid = -1;
1655 	if (cred) {
1656 		struct user_namespace *current_ns = current_user_ns();
1657 
1658 		ucred->uid = from_kuid_munged(current_ns, cred->euid);
1659 		ucred->gid = from_kgid_munged(current_ns, cred->egid);
1660 	}
1661 }
1662 
groups_to_user(sockptr_t dst,const struct group_info * src)1663 static int groups_to_user(sockptr_t dst, const struct group_info *src)
1664 {
1665 	struct user_namespace *user_ns = current_user_ns();
1666 	int i;
1667 
1668 	for (i = 0; i < src->ngroups; i++) {
1669 		gid_t gid = from_kgid_munged(user_ns, src->gid[i]);
1670 
1671 		if (copy_to_sockptr_offset(dst, i * sizeof(gid), &gid, sizeof(gid)))
1672 			return -EFAULT;
1673 	}
1674 
1675 	return 0;
1676 }
1677 
sk_getsockopt(struct sock * sk,int level,int optname,sockptr_t optval,sockptr_t optlen)1678 int sk_getsockopt(struct sock *sk, int level, int optname,
1679 		  sockptr_t optval, sockptr_t optlen)
1680 {
1681 	struct socket *sock = sk->sk_socket;
1682 
1683 	union {
1684 		int val;
1685 		u64 val64;
1686 		unsigned long ulval;
1687 		struct linger ling;
1688 		struct old_timeval32 tm32;
1689 		struct __kernel_old_timeval tm;
1690 		struct  __kernel_sock_timeval stm;
1691 		struct sock_txtime txtime;
1692 		struct so_timestamping timestamping;
1693 	} v;
1694 
1695 	int lv = sizeof(int);
1696 	int len;
1697 
1698 	if (copy_from_sockptr(&len, optlen, sizeof(int)))
1699 		return -EFAULT;
1700 	if (len < 0)
1701 		return -EINVAL;
1702 
1703 	memset(&v, 0, sizeof(v));
1704 
1705 	switch (optname) {
1706 	case SO_DEBUG:
1707 		v.val = sock_flag(sk, SOCK_DBG);
1708 		break;
1709 
1710 	case SO_DONTROUTE:
1711 		v.val = sock_flag(sk, SOCK_LOCALROUTE);
1712 		break;
1713 
1714 	case SO_BROADCAST:
1715 		v.val = sock_flag(sk, SOCK_BROADCAST);
1716 		break;
1717 
1718 	case SO_SNDBUF:
1719 		v.val = READ_ONCE(sk->sk_sndbuf);
1720 		break;
1721 
1722 	case SO_RCVBUF:
1723 		v.val = READ_ONCE(sk->sk_rcvbuf);
1724 		break;
1725 
1726 	case SO_REUSEADDR:
1727 		v.val = sk->sk_reuse;
1728 		break;
1729 
1730 	case SO_REUSEPORT:
1731 		v.val = sk->sk_reuseport;
1732 		break;
1733 
1734 	case SO_KEEPALIVE:
1735 		v.val = sock_flag(sk, SOCK_KEEPOPEN);
1736 		break;
1737 
1738 	case SO_TYPE:
1739 		v.val = sk->sk_type;
1740 		break;
1741 
1742 	case SO_PROTOCOL:
1743 		v.val = sk->sk_protocol;
1744 		break;
1745 
1746 	case SO_DOMAIN:
1747 		v.val = sk->sk_family;
1748 		break;
1749 
1750 	case SO_ERROR:
1751 		v.val = -sock_error(sk);
1752 		if (v.val == 0)
1753 			v.val = xchg(&sk->sk_err_soft, 0);
1754 		break;
1755 
1756 	case SO_OOBINLINE:
1757 		v.val = sock_flag(sk, SOCK_URGINLINE);
1758 		break;
1759 
1760 	case SO_NO_CHECK:
1761 		v.val = sk->sk_no_check_tx;
1762 		break;
1763 
1764 	case SO_PRIORITY:
1765 		v.val = READ_ONCE(sk->sk_priority);
1766 		break;
1767 
1768 	case SO_LINGER:
1769 		lv		= sizeof(v.ling);
1770 		v.ling.l_onoff	= sock_flag(sk, SOCK_LINGER);
1771 		v.ling.l_linger	= READ_ONCE(sk->sk_lingertime) / HZ;
1772 		break;
1773 
1774 	case SO_BSDCOMPAT:
1775 		break;
1776 
1777 	case SO_TIMESTAMP_OLD:
1778 		v.val = sock_flag(sk, SOCK_RCVTSTAMP) &&
1779 				!sock_flag(sk, SOCK_TSTAMP_NEW) &&
1780 				!sock_flag(sk, SOCK_RCVTSTAMPNS);
1781 		break;
1782 
1783 	case SO_TIMESTAMPNS_OLD:
1784 		v.val = sock_flag(sk, SOCK_RCVTSTAMPNS) && !sock_flag(sk, SOCK_TSTAMP_NEW);
1785 		break;
1786 
1787 	case SO_TIMESTAMP_NEW:
1788 		v.val = sock_flag(sk, SOCK_RCVTSTAMP) && sock_flag(sk, SOCK_TSTAMP_NEW);
1789 		break;
1790 
1791 	case SO_TIMESTAMPNS_NEW:
1792 		v.val = sock_flag(sk, SOCK_RCVTSTAMPNS) && sock_flag(sk, SOCK_TSTAMP_NEW);
1793 		break;
1794 
1795 	case SO_TIMESTAMPING_OLD:
1796 	case SO_TIMESTAMPING_NEW:
1797 		lv = sizeof(v.timestamping);
1798 		/* For the later-added case SO_TIMESTAMPING_NEW: Be strict about only
1799 		 * returning the flags when they were set through the same option.
1800 		 * Don't change the beviour for the old case SO_TIMESTAMPING_OLD.
1801 		 */
1802 		if (optname == SO_TIMESTAMPING_OLD || sock_flag(sk, SOCK_TSTAMP_NEW)) {
1803 			v.timestamping.flags = READ_ONCE(sk->sk_tsflags);
1804 			v.timestamping.bind_phc = READ_ONCE(sk->sk_bind_phc);
1805 		}
1806 		break;
1807 
1808 	case SO_RCVTIMEO_OLD:
1809 	case SO_RCVTIMEO_NEW:
1810 		lv = sock_get_timeout(READ_ONCE(sk->sk_rcvtimeo), &v,
1811 				      SO_RCVTIMEO_OLD == optname);
1812 		break;
1813 
1814 	case SO_SNDTIMEO_OLD:
1815 	case SO_SNDTIMEO_NEW:
1816 		lv = sock_get_timeout(READ_ONCE(sk->sk_sndtimeo), &v,
1817 				      SO_SNDTIMEO_OLD == optname);
1818 		break;
1819 
1820 	case SO_RCVLOWAT:
1821 		v.val = READ_ONCE(sk->sk_rcvlowat);
1822 		break;
1823 
1824 	case SO_SNDLOWAT:
1825 		v.val = 1;
1826 		break;
1827 
1828 	case SO_PASSCRED:
1829 		v.val = !!test_bit(SOCK_PASSCRED, &sock->flags);
1830 		break;
1831 
1832 	case SO_PASSPIDFD:
1833 		v.val = !!test_bit(SOCK_PASSPIDFD, &sock->flags);
1834 		break;
1835 
1836 	case SO_PEERCRED:
1837 	{
1838 		struct ucred peercred;
1839 		if (len > sizeof(peercred))
1840 			len = sizeof(peercred);
1841 
1842 		spin_lock(&sk->sk_peer_lock);
1843 		cred_to_ucred(sk->sk_peer_pid, sk->sk_peer_cred, &peercred);
1844 		spin_unlock(&sk->sk_peer_lock);
1845 
1846 		if (copy_to_sockptr(optval, &peercred, len))
1847 			return -EFAULT;
1848 		goto lenout;
1849 	}
1850 
1851 	case SO_PEERPIDFD:
1852 	{
1853 		struct pid *peer_pid;
1854 		struct file *pidfd_file = NULL;
1855 		int pidfd;
1856 
1857 		if (len > sizeof(pidfd))
1858 			len = sizeof(pidfd);
1859 
1860 		spin_lock(&sk->sk_peer_lock);
1861 		peer_pid = get_pid(sk->sk_peer_pid);
1862 		spin_unlock(&sk->sk_peer_lock);
1863 
1864 		if (!peer_pid)
1865 			return -ENODATA;
1866 
1867 		pidfd = pidfd_prepare(peer_pid, 0, &pidfd_file);
1868 		put_pid(peer_pid);
1869 		if (pidfd < 0)
1870 			return pidfd;
1871 
1872 		if (copy_to_sockptr(optval, &pidfd, len) ||
1873 		    copy_to_sockptr(optlen, &len, sizeof(int))) {
1874 			put_unused_fd(pidfd);
1875 			fput(pidfd_file);
1876 
1877 			return -EFAULT;
1878 		}
1879 
1880 		fd_install(pidfd, pidfd_file);
1881 		return 0;
1882 	}
1883 
1884 	case SO_PEERGROUPS:
1885 	{
1886 		const struct cred *cred;
1887 		int ret, n;
1888 
1889 		cred = sk_get_peer_cred(sk);
1890 		if (!cred)
1891 			return -ENODATA;
1892 
1893 		n = cred->group_info->ngroups;
1894 		if (len < n * sizeof(gid_t)) {
1895 			len = n * sizeof(gid_t);
1896 			put_cred(cred);
1897 			return copy_to_sockptr(optlen, &len, sizeof(int)) ? -EFAULT : -ERANGE;
1898 		}
1899 		len = n * sizeof(gid_t);
1900 
1901 		ret = groups_to_user(optval, cred->group_info);
1902 		put_cred(cred);
1903 		if (ret)
1904 			return ret;
1905 		goto lenout;
1906 	}
1907 
1908 	case SO_PEERNAME:
1909 	{
1910 		struct sockaddr_storage address;
1911 
1912 		lv = READ_ONCE(sock->ops)->getname(sock, (struct sockaddr *)&address, 2);
1913 		if (lv < 0)
1914 			return -ENOTCONN;
1915 		if (lv < len)
1916 			return -EINVAL;
1917 		if (copy_to_sockptr(optval, &address, len))
1918 			return -EFAULT;
1919 		goto lenout;
1920 	}
1921 
1922 	/* Dubious BSD thing... Probably nobody even uses it, but
1923 	 * the UNIX standard wants it for whatever reason... -DaveM
1924 	 */
1925 	case SO_ACCEPTCONN:
1926 		v.val = sk->sk_state == TCP_LISTEN;
1927 		break;
1928 
1929 	case SO_PASSSEC:
1930 		v.val = !!test_bit(SOCK_PASSSEC, &sock->flags);
1931 		break;
1932 
1933 	case SO_PEERSEC:
1934 		return security_socket_getpeersec_stream(sock,
1935 							 optval, optlen, len);
1936 
1937 	case SO_MARK:
1938 		v.val = READ_ONCE(sk->sk_mark);
1939 		break;
1940 
1941 	case SO_RCVMARK:
1942 		v.val = sock_flag(sk, SOCK_RCVMARK);
1943 		break;
1944 
1945 	case SO_RXQ_OVFL:
1946 		v.val = sock_flag(sk, SOCK_RXQ_OVFL);
1947 		break;
1948 
1949 	case SO_WIFI_STATUS:
1950 		v.val = sock_flag(sk, SOCK_WIFI_STATUS);
1951 		break;
1952 
1953 	case SO_PEEK_OFF:
1954 		if (!READ_ONCE(sock->ops)->set_peek_off)
1955 			return -EOPNOTSUPP;
1956 
1957 		v.val = READ_ONCE(sk->sk_peek_off);
1958 		break;
1959 	case SO_NOFCS:
1960 		v.val = sock_flag(sk, SOCK_NOFCS);
1961 		break;
1962 
1963 	case SO_BINDTODEVICE:
1964 		return sock_getbindtodevice(sk, optval, optlen, len);
1965 
1966 	case SO_GET_FILTER:
1967 		len = sk_get_filter(sk, optval, len);
1968 		if (len < 0)
1969 			return len;
1970 
1971 		goto lenout;
1972 
1973 	case SO_LOCK_FILTER:
1974 		v.val = sock_flag(sk, SOCK_FILTER_LOCKED);
1975 		break;
1976 
1977 	case SO_BPF_EXTENSIONS:
1978 		v.val = bpf_tell_extensions();
1979 		break;
1980 
1981 	case SO_SELECT_ERR_QUEUE:
1982 		v.val = sock_flag(sk, SOCK_SELECT_ERR_QUEUE);
1983 		break;
1984 
1985 #ifdef CONFIG_NET_RX_BUSY_POLL
1986 	case SO_BUSY_POLL:
1987 		v.val = READ_ONCE(sk->sk_ll_usec);
1988 		break;
1989 	case SO_PREFER_BUSY_POLL:
1990 		v.val = READ_ONCE(sk->sk_prefer_busy_poll);
1991 		break;
1992 #endif
1993 
1994 	case SO_MAX_PACING_RATE:
1995 		/* The READ_ONCE() pair with the WRITE_ONCE() in sk_setsockopt() */
1996 		if (sizeof(v.ulval) != sizeof(v.val) && len >= sizeof(v.ulval)) {
1997 			lv = sizeof(v.ulval);
1998 			v.ulval = READ_ONCE(sk->sk_max_pacing_rate);
1999 		} else {
2000 			/* 32bit version */
2001 			v.val = min_t(unsigned long, ~0U,
2002 				      READ_ONCE(sk->sk_max_pacing_rate));
2003 		}
2004 		break;
2005 
2006 	case SO_INCOMING_CPU:
2007 		v.val = READ_ONCE(sk->sk_incoming_cpu);
2008 		break;
2009 
2010 	case SO_MEMINFO:
2011 	{
2012 		u32 meminfo[SK_MEMINFO_VARS];
2013 
2014 		sk_get_meminfo(sk, meminfo);
2015 
2016 		len = min_t(unsigned int, len, sizeof(meminfo));
2017 		if (copy_to_sockptr(optval, &meminfo, len))
2018 			return -EFAULT;
2019 
2020 		goto lenout;
2021 	}
2022 
2023 #ifdef CONFIG_NET_RX_BUSY_POLL
2024 	case SO_INCOMING_NAPI_ID:
2025 		v.val = READ_ONCE(sk->sk_napi_id);
2026 
2027 		/* aggregate non-NAPI IDs down to 0 */
2028 		if (v.val < MIN_NAPI_ID)
2029 			v.val = 0;
2030 
2031 		break;
2032 #endif
2033 
2034 	case SO_COOKIE:
2035 		lv = sizeof(u64);
2036 		if (len < lv)
2037 			return -EINVAL;
2038 		v.val64 = sock_gen_cookie(sk);
2039 		break;
2040 
2041 	case SO_ZEROCOPY:
2042 		v.val = sock_flag(sk, SOCK_ZEROCOPY);
2043 		break;
2044 
2045 	case SO_TXTIME:
2046 		lv = sizeof(v.txtime);
2047 		v.txtime.clockid = sk->sk_clockid;
2048 		v.txtime.flags |= sk->sk_txtime_deadline_mode ?
2049 				  SOF_TXTIME_DEADLINE_MODE : 0;
2050 		v.txtime.flags |= sk->sk_txtime_report_errors ?
2051 				  SOF_TXTIME_REPORT_ERRORS : 0;
2052 		break;
2053 
2054 	case SO_BINDTOIFINDEX:
2055 		v.val = READ_ONCE(sk->sk_bound_dev_if);
2056 		break;
2057 
2058 	case SO_NETNS_COOKIE:
2059 		lv = sizeof(u64);
2060 		if (len != lv)
2061 			return -EINVAL;
2062 		v.val64 = sock_net(sk)->net_cookie;
2063 		break;
2064 
2065 	case SO_BUF_LOCK:
2066 		v.val = sk->sk_userlocks & SOCK_BUF_LOCK_MASK;
2067 		break;
2068 
2069 	case SO_RESERVE_MEM:
2070 		v.val = READ_ONCE(sk->sk_reserved_mem);
2071 		break;
2072 
2073 	case SO_TXREHASH:
2074 		/* Paired with WRITE_ONCE() in sk_setsockopt() */
2075 		v.val = READ_ONCE(sk->sk_txrehash);
2076 		break;
2077 
2078 	default:
2079 		/* We implement the SO_SNDLOWAT etc to not be settable
2080 		 * (1003.1g 7).
2081 		 */
2082 		return -ENOPROTOOPT;
2083 	}
2084 
2085 	if (len > lv)
2086 		len = lv;
2087 	if (copy_to_sockptr(optval, &v, len))
2088 		return -EFAULT;
2089 lenout:
2090 	if (copy_to_sockptr(optlen, &len, sizeof(int)))
2091 		return -EFAULT;
2092 	return 0;
2093 }
2094 
2095 /*
2096  * Initialize an sk_lock.
2097  *
2098  * (We also register the sk_lock with the lock validator.)
2099  */
sock_lock_init(struct sock * sk)2100 static inline void sock_lock_init(struct sock *sk)
2101 {
2102 	if (sk->sk_kern_sock)
2103 		sock_lock_init_class_and_name(
2104 			sk,
2105 			af_family_kern_slock_key_strings[sk->sk_family],
2106 			af_family_kern_slock_keys + sk->sk_family,
2107 			af_family_kern_key_strings[sk->sk_family],
2108 			af_family_kern_keys + sk->sk_family);
2109 	else
2110 		sock_lock_init_class_and_name(
2111 			sk,
2112 			af_family_slock_key_strings[sk->sk_family],
2113 			af_family_slock_keys + sk->sk_family,
2114 			af_family_key_strings[sk->sk_family],
2115 			af_family_keys + sk->sk_family);
2116 }
2117 
2118 /*
2119  * Copy all fields from osk to nsk but nsk->sk_refcnt must not change yet,
2120  * even temporarily, because of RCU lookups. sk_node should also be left as is.
2121  * We must not copy fields between sk_dontcopy_begin and sk_dontcopy_end
2122  */
sock_copy(struct sock * nsk,const struct sock * osk)2123 static void sock_copy(struct sock *nsk, const struct sock *osk)
2124 {
2125 	const struct proto *prot = READ_ONCE(osk->sk_prot);
2126 #ifdef CONFIG_SECURITY_NETWORK
2127 	void *sptr = nsk->sk_security;
2128 #endif
2129 
2130 	/* If we move sk_tx_queue_mapping out of the private section,
2131 	 * we must check if sk_tx_queue_clear() is called after
2132 	 * sock_copy() in sk_clone_lock().
2133 	 */
2134 	BUILD_BUG_ON(offsetof(struct sock, sk_tx_queue_mapping) <
2135 		     offsetof(struct sock, sk_dontcopy_begin) ||
2136 		     offsetof(struct sock, sk_tx_queue_mapping) >=
2137 		     offsetof(struct sock, sk_dontcopy_end));
2138 
2139 	memcpy(nsk, osk, offsetof(struct sock, sk_dontcopy_begin));
2140 
2141 	unsafe_memcpy(&nsk->sk_dontcopy_end, &osk->sk_dontcopy_end,
2142 		      prot->obj_size - offsetof(struct sock, sk_dontcopy_end),
2143 		      /* alloc is larger than struct, see sk_prot_alloc() */);
2144 
2145 #ifdef CONFIG_SECURITY_NETWORK
2146 	nsk->sk_security = sptr;
2147 	security_sk_clone(osk, nsk);
2148 #endif
2149 }
2150 
sk_prot_alloc(struct proto * prot,gfp_t priority,int family)2151 static struct sock *sk_prot_alloc(struct proto *prot, gfp_t priority,
2152 		int family)
2153 {
2154 	struct sock *sk;
2155 	struct kmem_cache *slab;
2156 
2157 	slab = prot->slab;
2158 	if (slab != NULL) {
2159 		sk = kmem_cache_alloc(slab, priority & ~__GFP_ZERO);
2160 		if (!sk)
2161 			return sk;
2162 		if (want_init_on_alloc(priority))
2163 			sk_prot_clear_nulls(sk, prot->obj_size);
2164 	} else
2165 		sk = kmalloc(prot->obj_size, priority);
2166 
2167 	if (sk != NULL) {
2168 		if (security_sk_alloc(sk, family, priority))
2169 			goto out_free;
2170 
2171 		if (!try_module_get(prot->owner))
2172 			goto out_free_sec;
2173 	}
2174 
2175 	return sk;
2176 
2177 out_free_sec:
2178 	security_sk_free(sk);
2179 out_free:
2180 	if (slab != NULL)
2181 		kmem_cache_free(slab, sk);
2182 	else
2183 		kfree(sk);
2184 	return NULL;
2185 }
2186 
sk_prot_free(struct proto * prot,struct sock * sk)2187 static void sk_prot_free(struct proto *prot, struct sock *sk)
2188 {
2189 	struct kmem_cache *slab;
2190 	struct module *owner;
2191 
2192 	owner = prot->owner;
2193 	slab = prot->slab;
2194 
2195 	cgroup_sk_free(&sk->sk_cgrp_data);
2196 	mem_cgroup_sk_free(sk);
2197 	security_sk_free(sk);
2198 	if (slab != NULL)
2199 		kmem_cache_free(slab, sk);
2200 	else
2201 		kfree(sk);
2202 	module_put(owner);
2203 }
2204 
2205 /**
2206  *	sk_alloc - All socket objects are allocated here
2207  *	@net: the applicable net namespace
2208  *	@family: protocol family
2209  *	@priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
2210  *	@prot: struct proto associated with this new sock instance
2211  *	@kern: is this to be a kernel socket?
2212  */
sk_alloc(struct net * net,int family,gfp_t priority,struct proto * prot,int kern)2213 struct sock *sk_alloc(struct net *net, int family, gfp_t priority,
2214 		      struct proto *prot, int kern)
2215 {
2216 	struct sock *sk;
2217 
2218 	sk = sk_prot_alloc(prot, priority | __GFP_ZERO, family);
2219 	if (sk) {
2220 		sk->sk_family = family;
2221 		/*
2222 		 * See comment in struct sock definition to understand
2223 		 * why we need sk_prot_creator -acme
2224 		 */
2225 		sk->sk_prot = sk->sk_prot_creator = prot;
2226 		sk->sk_kern_sock = kern;
2227 		sock_lock_init(sk);
2228 		sk->sk_net_refcnt = kern ? 0 : 1;
2229 		if (likely(sk->sk_net_refcnt)) {
2230 			get_net_track(net, &sk->ns_tracker, priority);
2231 			sock_inuse_add(net, 1);
2232 		} else {
2233 			__netns_tracker_alloc(net, &sk->ns_tracker,
2234 					      false, priority);
2235 		}
2236 
2237 		sock_net_set(sk, net);
2238 		refcount_set(&sk->sk_wmem_alloc, 1);
2239 
2240 		mem_cgroup_sk_alloc(sk);
2241 		cgroup_sk_alloc(&sk->sk_cgrp_data);
2242 		sock_update_classid(&sk->sk_cgrp_data);
2243 		sock_update_netprioidx(&sk->sk_cgrp_data);
2244 		sk_tx_queue_clear(sk);
2245 	}
2246 
2247 	return sk;
2248 }
2249 EXPORT_SYMBOL(sk_alloc);
2250 
2251 /* Sockets having SOCK_RCU_FREE will call this function after one RCU
2252  * grace period. This is the case for UDP sockets and TCP listeners.
2253  */
__sk_destruct(struct rcu_head * head)2254 static void __sk_destruct(struct rcu_head *head)
2255 {
2256 	struct sock *sk = container_of(head, struct sock, sk_rcu);
2257 	struct sk_filter *filter;
2258 
2259 	if (sk->sk_destruct)
2260 		sk->sk_destruct(sk);
2261 
2262 	filter = rcu_dereference_check(sk->sk_filter,
2263 				       refcount_read(&sk->sk_wmem_alloc) == 0);
2264 	if (filter) {
2265 		sk_filter_uncharge(sk, filter);
2266 		RCU_INIT_POINTER(sk->sk_filter, NULL);
2267 	}
2268 
2269 	sock_disable_timestamp(sk, SK_FLAGS_TIMESTAMP);
2270 
2271 #ifdef CONFIG_BPF_SYSCALL
2272 	bpf_sk_storage_free(sk);
2273 #endif
2274 
2275 	if (atomic_read(&sk->sk_omem_alloc))
2276 		pr_debug("%s: optmem leakage (%d bytes) detected\n",
2277 			 __func__, atomic_read(&sk->sk_omem_alloc));
2278 
2279 	if (sk->sk_frag.page) {
2280 		put_page(sk->sk_frag.page);
2281 		sk->sk_frag.page = NULL;
2282 	}
2283 
2284 	/* We do not need to acquire sk->sk_peer_lock, we are the last user. */
2285 	put_cred(sk->sk_peer_cred);
2286 	put_pid(sk->sk_peer_pid);
2287 
2288 	if (likely(sk->sk_net_refcnt))
2289 		put_net_track(sock_net(sk), &sk->ns_tracker);
2290 	else
2291 		__netns_tracker_free(sock_net(sk), &sk->ns_tracker, false);
2292 
2293 	sk_prot_free(sk->sk_prot_creator, sk);
2294 }
2295 
sk_destruct(struct sock * sk)2296 void sk_destruct(struct sock *sk)
2297 {
2298 	bool use_call_rcu = sock_flag(sk, SOCK_RCU_FREE);
2299 
2300 	if (rcu_access_pointer(sk->sk_reuseport_cb)) {
2301 		reuseport_detach_sock(sk);
2302 		use_call_rcu = true;
2303 	}
2304 
2305 	if (use_call_rcu)
2306 		call_rcu(&sk->sk_rcu, __sk_destruct);
2307 	else
2308 		__sk_destruct(&sk->sk_rcu);
2309 }
2310 
__sk_free(struct sock * sk)2311 static void __sk_free(struct sock *sk)
2312 {
2313 	if (likely(sk->sk_net_refcnt))
2314 		sock_inuse_add(sock_net(sk), -1);
2315 
2316 	if (unlikely(sk->sk_net_refcnt && sock_diag_has_destroy_listeners(sk)))
2317 		sock_diag_broadcast_destroy(sk);
2318 	else
2319 		sk_destruct(sk);
2320 }
2321 
sk_free(struct sock * sk)2322 void sk_free(struct sock *sk)
2323 {
2324 	/*
2325 	 * We subtract one from sk_wmem_alloc and can know if
2326 	 * some packets are still in some tx queue.
2327 	 * If not null, sock_wfree() will call __sk_free(sk) later
2328 	 */
2329 	if (refcount_dec_and_test(&sk->sk_wmem_alloc))
2330 		__sk_free(sk);
2331 }
2332 EXPORT_SYMBOL(sk_free);
2333 
sk_init_common(struct sock * sk)2334 static void sk_init_common(struct sock *sk)
2335 {
2336 	skb_queue_head_init(&sk->sk_receive_queue);
2337 	skb_queue_head_init(&sk->sk_write_queue);
2338 	skb_queue_head_init(&sk->sk_error_queue);
2339 
2340 	rwlock_init(&sk->sk_callback_lock);
2341 	lockdep_set_class_and_name(&sk->sk_receive_queue.lock,
2342 			af_rlock_keys + sk->sk_family,
2343 			af_family_rlock_key_strings[sk->sk_family]);
2344 	lockdep_set_class_and_name(&sk->sk_write_queue.lock,
2345 			af_wlock_keys + sk->sk_family,
2346 			af_family_wlock_key_strings[sk->sk_family]);
2347 	lockdep_set_class_and_name(&sk->sk_error_queue.lock,
2348 			af_elock_keys + sk->sk_family,
2349 			af_family_elock_key_strings[sk->sk_family]);
2350 	if (sk->sk_kern_sock)
2351 		lockdep_set_class_and_name(&sk->sk_callback_lock,
2352 			af_kern_callback_keys + sk->sk_family,
2353 			af_family_kern_clock_key_strings[sk->sk_family]);
2354 	else
2355 		lockdep_set_class_and_name(&sk->sk_callback_lock,
2356 			af_callback_keys + sk->sk_family,
2357 			af_family_clock_key_strings[sk->sk_family]);
2358 }
2359 
2360 /**
2361  *	sk_clone_lock - clone a socket, and lock its clone
2362  *	@sk: the socket to clone
2363  *	@priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
2364  *
2365  *	Caller must unlock socket even in error path (bh_unlock_sock(newsk))
2366  */
sk_clone_lock(const struct sock * sk,const gfp_t priority)2367 struct sock *sk_clone_lock(const struct sock *sk, const gfp_t priority)
2368 {
2369 	struct proto *prot = READ_ONCE(sk->sk_prot);
2370 	struct sk_filter *filter;
2371 	bool is_charged = true;
2372 	struct sock *newsk;
2373 
2374 	newsk = sk_prot_alloc(prot, priority, sk->sk_family);
2375 	if (!newsk)
2376 		goto out;
2377 
2378 	sock_copy(newsk, sk);
2379 
2380 	newsk->sk_prot_creator = prot;
2381 
2382 	/* SANITY */
2383 	if (likely(newsk->sk_net_refcnt)) {
2384 		get_net_track(sock_net(newsk), &newsk->ns_tracker, priority);
2385 		sock_inuse_add(sock_net(newsk), 1);
2386 	} else {
2387 		/* Kernel sockets are not elevating the struct net refcount.
2388 		 * Instead, use a tracker to more easily detect if a layer
2389 		 * is not properly dismantling its kernel sockets at netns
2390 		 * destroy time.
2391 		 */
2392 		__netns_tracker_alloc(sock_net(newsk), &newsk->ns_tracker,
2393 				      false, priority);
2394 	}
2395 	sk_node_init(&newsk->sk_node);
2396 	sock_lock_init(newsk);
2397 	bh_lock_sock(newsk);
2398 	newsk->sk_backlog.head	= newsk->sk_backlog.tail = NULL;
2399 	newsk->sk_backlog.len = 0;
2400 
2401 	atomic_set(&newsk->sk_rmem_alloc, 0);
2402 
2403 	/* sk_wmem_alloc set to one (see sk_free() and sock_wfree()) */
2404 	refcount_set(&newsk->sk_wmem_alloc, 1);
2405 
2406 	atomic_set(&newsk->sk_omem_alloc, 0);
2407 	sk_init_common(newsk);
2408 
2409 	newsk->sk_dst_cache	= NULL;
2410 	newsk->sk_dst_pending_confirm = 0;
2411 	newsk->sk_wmem_queued	= 0;
2412 	newsk->sk_forward_alloc = 0;
2413 	newsk->sk_reserved_mem  = 0;
2414 	atomic_set(&newsk->sk_drops, 0);
2415 	newsk->sk_send_head	= NULL;
2416 	newsk->sk_userlocks	= sk->sk_userlocks & ~SOCK_BINDPORT_LOCK;
2417 	atomic_set(&newsk->sk_zckey, 0);
2418 
2419 	sock_reset_flag(newsk, SOCK_DONE);
2420 
2421 	/* sk->sk_memcg will be populated at accept() time */
2422 	newsk->sk_memcg = NULL;
2423 
2424 	cgroup_sk_clone(&newsk->sk_cgrp_data);
2425 
2426 	rcu_read_lock();
2427 	filter = rcu_dereference(sk->sk_filter);
2428 	if (filter != NULL)
2429 		/* though it's an empty new sock, the charging may fail
2430 		 * if sysctl_optmem_max was changed between creation of
2431 		 * original socket and cloning
2432 		 */
2433 		is_charged = sk_filter_charge(newsk, filter);
2434 	RCU_INIT_POINTER(newsk->sk_filter, filter);
2435 	rcu_read_unlock();
2436 
2437 	if (unlikely(!is_charged || xfrm_sk_clone_policy(newsk, sk))) {
2438 		/* We need to make sure that we don't uncharge the new
2439 		 * socket if we couldn't charge it in the first place
2440 		 * as otherwise we uncharge the parent's filter.
2441 		 */
2442 		if (!is_charged)
2443 			RCU_INIT_POINTER(newsk->sk_filter, NULL);
2444 		sk_free_unlock_clone(newsk);
2445 		newsk = NULL;
2446 		goto out;
2447 	}
2448 	RCU_INIT_POINTER(newsk->sk_reuseport_cb, NULL);
2449 
2450 	if (bpf_sk_storage_clone(sk, newsk)) {
2451 		sk_free_unlock_clone(newsk);
2452 		newsk = NULL;
2453 		goto out;
2454 	}
2455 
2456 	/* Clear sk_user_data if parent had the pointer tagged
2457 	 * as not suitable for copying when cloning.
2458 	 */
2459 	if (sk_user_data_is_nocopy(newsk))
2460 		newsk->sk_user_data = NULL;
2461 
2462 	newsk->sk_err	   = 0;
2463 	newsk->sk_err_soft = 0;
2464 	newsk->sk_priority = 0;
2465 	newsk->sk_incoming_cpu = raw_smp_processor_id();
2466 
2467 	/* Before updating sk_refcnt, we must commit prior changes to memory
2468 	 * (Documentation/RCU/rculist_nulls.rst for details)
2469 	 */
2470 	smp_wmb();
2471 	refcount_set(&newsk->sk_refcnt, 2);
2472 
2473 	sk_set_socket(newsk, NULL);
2474 	sk_tx_queue_clear(newsk);
2475 	RCU_INIT_POINTER(newsk->sk_wq, NULL);
2476 
2477 	if (newsk->sk_prot->sockets_allocated)
2478 		sk_sockets_allocated_inc(newsk);
2479 
2480 	if (sock_needs_netstamp(sk) && newsk->sk_flags & SK_FLAGS_TIMESTAMP)
2481 		net_enable_timestamp();
2482 out:
2483 	return newsk;
2484 }
2485 EXPORT_SYMBOL_GPL(sk_clone_lock);
2486 
sk_free_unlock_clone(struct sock * sk)2487 void sk_free_unlock_clone(struct sock *sk)
2488 {
2489 	/* It is still raw copy of parent, so invalidate
2490 	 * destructor and make plain sk_free() */
2491 	sk->sk_destruct = NULL;
2492 	bh_unlock_sock(sk);
2493 	sk_free(sk);
2494 }
2495 EXPORT_SYMBOL_GPL(sk_free_unlock_clone);
2496 
sk_dst_gso_max_size(struct sock * sk,struct dst_entry * dst)2497 static u32 sk_dst_gso_max_size(struct sock *sk, struct dst_entry *dst)
2498 {
2499 	bool is_ipv6 = false;
2500 	u32 max_size;
2501 
2502 #if IS_ENABLED(CONFIG_IPV6)
2503 	is_ipv6 = (sk->sk_family == AF_INET6 &&
2504 		   !ipv6_addr_v4mapped(&sk->sk_v6_rcv_saddr));
2505 #endif
2506 	/* pairs with the WRITE_ONCE() in netif_set_gso(_ipv4)_max_size() */
2507 	max_size = is_ipv6 ? READ_ONCE(dst->dev->gso_max_size) :
2508 			READ_ONCE(dst->dev->gso_ipv4_max_size);
2509 	if (max_size > GSO_LEGACY_MAX_SIZE && !sk_is_tcp(sk))
2510 		max_size = GSO_LEGACY_MAX_SIZE;
2511 
2512 	return max_size - (MAX_TCP_HEADER + 1);
2513 }
2514 
sk_setup_caps(struct sock * sk,struct dst_entry * dst)2515 void sk_setup_caps(struct sock *sk, struct dst_entry *dst)
2516 {
2517 	u32 max_segs = 1;
2518 
2519 	sk->sk_route_caps = dst->dev->features;
2520 	if (sk_is_tcp(sk))
2521 		sk->sk_route_caps |= NETIF_F_GSO;
2522 	if (sk->sk_route_caps & NETIF_F_GSO)
2523 		sk->sk_route_caps |= NETIF_F_GSO_SOFTWARE;
2524 	if (unlikely(sk->sk_gso_disabled))
2525 		sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
2526 	if (sk_can_gso(sk)) {
2527 		if (dst->header_len && !xfrm_dst_offload_ok(dst)) {
2528 			sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
2529 		} else {
2530 			sk->sk_route_caps |= NETIF_F_SG | NETIF_F_HW_CSUM;
2531 			sk->sk_gso_max_size = sk_dst_gso_max_size(sk, dst);
2532 			/* pairs with the WRITE_ONCE() in netif_set_gso_max_segs() */
2533 			max_segs = max_t(u32, READ_ONCE(dst->dev->gso_max_segs), 1);
2534 		}
2535 	}
2536 	sk->sk_gso_max_segs = max_segs;
2537 	sk_dst_set(sk, dst);
2538 }
2539 EXPORT_SYMBOL_GPL(sk_setup_caps);
2540 
2541 /*
2542  *	Simple resource managers for sockets.
2543  */
2544 
2545 
2546 /*
2547  * Write buffer destructor automatically called from kfree_skb.
2548  */
sock_wfree(struct sk_buff * skb)2549 void sock_wfree(struct sk_buff *skb)
2550 {
2551 	struct sock *sk = skb->sk;
2552 	unsigned int len = skb->truesize;
2553 	bool free;
2554 
2555 	if (!sock_flag(sk, SOCK_USE_WRITE_QUEUE)) {
2556 		if (sock_flag(sk, SOCK_RCU_FREE) &&
2557 		    sk->sk_write_space == sock_def_write_space) {
2558 			rcu_read_lock();
2559 			free = refcount_sub_and_test(len, &sk->sk_wmem_alloc);
2560 			sock_def_write_space_wfree(sk);
2561 			rcu_read_unlock();
2562 			if (unlikely(free))
2563 				__sk_free(sk);
2564 			return;
2565 		}
2566 
2567 		/*
2568 		 * Keep a reference on sk_wmem_alloc, this will be released
2569 		 * after sk_write_space() call
2570 		 */
2571 		WARN_ON(refcount_sub_and_test(len - 1, &sk->sk_wmem_alloc));
2572 		sk->sk_write_space(sk);
2573 		len = 1;
2574 	}
2575 	/*
2576 	 * if sk_wmem_alloc reaches 0, we must finish what sk_free()
2577 	 * could not do because of in-flight packets
2578 	 */
2579 	if (refcount_sub_and_test(len, &sk->sk_wmem_alloc))
2580 		__sk_free(sk);
2581 }
2582 EXPORT_SYMBOL(sock_wfree);
2583 
2584 /* This variant of sock_wfree() is used by TCP,
2585  * since it sets SOCK_USE_WRITE_QUEUE.
2586  */
__sock_wfree(struct sk_buff * skb)2587 void __sock_wfree(struct sk_buff *skb)
2588 {
2589 	struct sock *sk = skb->sk;
2590 
2591 	if (refcount_sub_and_test(skb->truesize, &sk->sk_wmem_alloc))
2592 		__sk_free(sk);
2593 }
2594 
skb_set_owner_w(struct sk_buff * skb,struct sock * sk)2595 void skb_set_owner_w(struct sk_buff *skb, struct sock *sk)
2596 {
2597 	skb_orphan(skb);
2598 #ifdef CONFIG_INET
2599 	if (unlikely(!sk_fullsock(sk)))
2600 		return skb_set_owner_edemux(skb, sk);
2601 #endif
2602 	skb->sk = sk;
2603 	skb->destructor = sock_wfree;
2604 	skb_set_hash_from_sk(skb, sk);
2605 	/*
2606 	 * We used to take a refcount on sk, but following operation
2607 	 * is enough to guarantee sk_free() won't free this sock until
2608 	 * all in-flight packets are completed
2609 	 */
2610 	refcount_add(skb->truesize, &sk->sk_wmem_alloc);
2611 }
2612 EXPORT_SYMBOL(skb_set_owner_w);
2613 
can_skb_orphan_partial(const struct sk_buff * skb)2614 static bool can_skb_orphan_partial(const struct sk_buff *skb)
2615 {
2616 	/* Drivers depend on in-order delivery for crypto offload,
2617 	 * partial orphan breaks out-of-order-OK logic.
2618 	 */
2619 	if (skb_is_decrypted(skb))
2620 		return false;
2621 
2622 	return (skb->destructor == sock_wfree ||
2623 		(IS_ENABLED(CONFIG_INET) && skb->destructor == tcp_wfree));
2624 }
2625 
2626 /* This helper is used by netem, as it can hold packets in its
2627  * delay queue. We want to allow the owner socket to send more
2628  * packets, as if they were already TX completed by a typical driver.
2629  * But we also want to keep skb->sk set because some packet schedulers
2630  * rely on it (sch_fq for example).
2631  */
skb_orphan_partial(struct sk_buff * skb)2632 void skb_orphan_partial(struct sk_buff *skb)
2633 {
2634 	if (skb_is_tcp_pure_ack(skb))
2635 		return;
2636 
2637 	if (can_skb_orphan_partial(skb) && skb_set_owner_sk_safe(skb, skb->sk))
2638 		return;
2639 
2640 	skb_orphan(skb);
2641 }
2642 EXPORT_SYMBOL(skb_orphan_partial);
2643 
2644 /*
2645  * Read buffer destructor automatically called from kfree_skb.
2646  */
sock_rfree(struct sk_buff * skb)2647 void sock_rfree(struct sk_buff *skb)
2648 {
2649 	struct sock *sk = skb->sk;
2650 	unsigned int len = skb->truesize;
2651 
2652 	atomic_sub(len, &sk->sk_rmem_alloc);
2653 	sk_mem_uncharge(sk, len);
2654 }
2655 EXPORT_SYMBOL(sock_rfree);
2656 
2657 /*
2658  * Buffer destructor for skbs that are not used directly in read or write
2659  * path, e.g. for error handler skbs. Automatically called from kfree_skb.
2660  */
sock_efree(struct sk_buff * skb)2661 void sock_efree(struct sk_buff *skb)
2662 {
2663 	sock_put(skb->sk);
2664 }
2665 EXPORT_SYMBOL(sock_efree);
2666 
2667 /* Buffer destructor for prefetch/receive path where reference count may
2668  * not be held, e.g. for listen sockets.
2669  */
2670 #ifdef CONFIG_INET
sock_pfree(struct sk_buff * skb)2671 void sock_pfree(struct sk_buff *skb)
2672 {
2673 	struct sock *sk = skb->sk;
2674 
2675 	if (!sk_is_refcounted(sk))
2676 		return;
2677 
2678 	if (sk->sk_state == TCP_NEW_SYN_RECV && inet_reqsk(sk)->syncookie) {
2679 		inet_reqsk(sk)->rsk_listener = NULL;
2680 		reqsk_free(inet_reqsk(sk));
2681 		return;
2682 	}
2683 
2684 	sock_gen_put(sk);
2685 }
2686 EXPORT_SYMBOL(sock_pfree);
2687 #endif /* CONFIG_INET */
2688 
sock_i_uid(struct sock * sk)2689 kuid_t sock_i_uid(struct sock *sk)
2690 {
2691 	kuid_t uid;
2692 
2693 	read_lock_bh(&sk->sk_callback_lock);
2694 	uid = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_uid : GLOBAL_ROOT_UID;
2695 	read_unlock_bh(&sk->sk_callback_lock);
2696 	return uid;
2697 }
2698 EXPORT_SYMBOL(sock_i_uid);
2699 
__sock_i_ino(struct sock * sk)2700 unsigned long __sock_i_ino(struct sock *sk)
2701 {
2702 	unsigned long ino;
2703 
2704 	read_lock(&sk->sk_callback_lock);
2705 	ino = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_ino : 0;
2706 	read_unlock(&sk->sk_callback_lock);
2707 	return ino;
2708 }
2709 EXPORT_SYMBOL(__sock_i_ino);
2710 
sock_i_ino(struct sock * sk)2711 unsigned long sock_i_ino(struct sock *sk)
2712 {
2713 	unsigned long ino;
2714 
2715 	local_bh_disable();
2716 	ino = __sock_i_ino(sk);
2717 	local_bh_enable();
2718 	return ino;
2719 }
2720 EXPORT_SYMBOL(sock_i_ino);
2721 
2722 /*
2723  * Allocate a skb from the socket's send buffer.
2724  */
sock_wmalloc(struct sock * sk,unsigned long size,int force,gfp_t priority)2725 struct sk_buff *sock_wmalloc(struct sock *sk, unsigned long size, int force,
2726 			     gfp_t priority)
2727 {
2728 	if (force ||
2729 	    refcount_read(&sk->sk_wmem_alloc) < READ_ONCE(sk->sk_sndbuf)) {
2730 		struct sk_buff *skb = alloc_skb(size, priority);
2731 
2732 		if (skb) {
2733 			skb_set_owner_w(skb, sk);
2734 			return skb;
2735 		}
2736 	}
2737 	return NULL;
2738 }
2739 EXPORT_SYMBOL(sock_wmalloc);
2740 
sock_ofree(struct sk_buff * skb)2741 static void sock_ofree(struct sk_buff *skb)
2742 {
2743 	struct sock *sk = skb->sk;
2744 
2745 	atomic_sub(skb->truesize, &sk->sk_omem_alloc);
2746 }
2747 
sock_omalloc(struct sock * sk,unsigned long size,gfp_t priority)2748 struct sk_buff *sock_omalloc(struct sock *sk, unsigned long size,
2749 			     gfp_t priority)
2750 {
2751 	struct sk_buff *skb;
2752 
2753 	/* small safe race: SKB_TRUESIZE may differ from final skb->truesize */
2754 	if (atomic_read(&sk->sk_omem_alloc) + SKB_TRUESIZE(size) >
2755 	    READ_ONCE(sock_net(sk)->core.sysctl_optmem_max))
2756 		return NULL;
2757 
2758 	skb = alloc_skb(size, priority);
2759 	if (!skb)
2760 		return NULL;
2761 
2762 	atomic_add(skb->truesize, &sk->sk_omem_alloc);
2763 	skb->sk = sk;
2764 	skb->destructor = sock_ofree;
2765 	return skb;
2766 }
2767 
2768 /*
2769  * Allocate a memory block from the socket's option memory buffer.
2770  */
sock_kmalloc(struct sock * sk,int size,gfp_t priority)2771 void *sock_kmalloc(struct sock *sk, int size, gfp_t priority)
2772 {
2773 	int optmem_max = READ_ONCE(sock_net(sk)->core.sysctl_optmem_max);
2774 
2775 	if ((unsigned int)size <= optmem_max &&
2776 	    atomic_read(&sk->sk_omem_alloc) + size < optmem_max) {
2777 		void *mem;
2778 		/* First do the add, to avoid the race if kmalloc
2779 		 * might sleep.
2780 		 */
2781 		atomic_add(size, &sk->sk_omem_alloc);
2782 		mem = kmalloc(size, priority);
2783 		if (mem)
2784 			return mem;
2785 		atomic_sub(size, &sk->sk_omem_alloc);
2786 	}
2787 	return NULL;
2788 }
2789 EXPORT_SYMBOL(sock_kmalloc);
2790 
2791 /* Free an option memory block. Note, we actually want the inline
2792  * here as this allows gcc to detect the nullify and fold away the
2793  * condition entirely.
2794  */
__sock_kfree_s(struct sock * sk,void * mem,int size,const bool nullify)2795 static inline void __sock_kfree_s(struct sock *sk, void *mem, int size,
2796 				  const bool nullify)
2797 {
2798 	if (WARN_ON_ONCE(!mem))
2799 		return;
2800 	if (nullify)
2801 		kfree_sensitive(mem);
2802 	else
2803 		kfree(mem);
2804 	atomic_sub(size, &sk->sk_omem_alloc);
2805 }
2806 
sock_kfree_s(struct sock * sk,void * mem,int size)2807 void sock_kfree_s(struct sock *sk, void *mem, int size)
2808 {
2809 	__sock_kfree_s(sk, mem, size, false);
2810 }
2811 EXPORT_SYMBOL(sock_kfree_s);
2812 
sock_kzfree_s(struct sock * sk,void * mem,int size)2813 void sock_kzfree_s(struct sock *sk, void *mem, int size)
2814 {
2815 	__sock_kfree_s(sk, mem, size, true);
2816 }
2817 EXPORT_SYMBOL(sock_kzfree_s);
2818 
2819 /* It is almost wait_for_tcp_memory minus release_sock/lock_sock.
2820    I think, these locks should be removed for datagram sockets.
2821  */
sock_wait_for_wmem(struct sock * sk,long timeo)2822 static long sock_wait_for_wmem(struct sock *sk, long timeo)
2823 {
2824 	DEFINE_WAIT(wait);
2825 
2826 	sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
2827 	for (;;) {
2828 		if (!timeo)
2829 			break;
2830 		if (signal_pending(current))
2831 			break;
2832 		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
2833 		prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
2834 		if (refcount_read(&sk->sk_wmem_alloc) < READ_ONCE(sk->sk_sndbuf))
2835 			break;
2836 		if (READ_ONCE(sk->sk_shutdown) & SEND_SHUTDOWN)
2837 			break;
2838 		if (READ_ONCE(sk->sk_err))
2839 			break;
2840 		timeo = schedule_timeout(timeo);
2841 	}
2842 	finish_wait(sk_sleep(sk), &wait);
2843 	return timeo;
2844 }
2845 
2846 
2847 /*
2848  *	Generic send/receive buffer handlers
2849  */
2850 
sock_alloc_send_pskb(struct sock * sk,unsigned long header_len,unsigned long data_len,int noblock,int * errcode,int max_page_order)2851 struct sk_buff *sock_alloc_send_pskb(struct sock *sk, unsigned long header_len,
2852 				     unsigned long data_len, int noblock,
2853 				     int *errcode, int max_page_order)
2854 {
2855 	struct sk_buff *skb;
2856 	long timeo;
2857 	int err;
2858 
2859 	timeo = sock_sndtimeo(sk, noblock);
2860 	for (;;) {
2861 		err = sock_error(sk);
2862 		if (err != 0)
2863 			goto failure;
2864 
2865 		err = -EPIPE;
2866 		if (READ_ONCE(sk->sk_shutdown) & SEND_SHUTDOWN)
2867 			goto failure;
2868 
2869 		if (sk_wmem_alloc_get(sk) < READ_ONCE(sk->sk_sndbuf))
2870 			break;
2871 
2872 		sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
2873 		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
2874 		err = -EAGAIN;
2875 		if (!timeo)
2876 			goto failure;
2877 		if (signal_pending(current))
2878 			goto interrupted;
2879 		timeo = sock_wait_for_wmem(sk, timeo);
2880 	}
2881 	skb = alloc_skb_with_frags(header_len, data_len, max_page_order,
2882 				   errcode, sk->sk_allocation);
2883 	if (skb)
2884 		skb_set_owner_w(skb, sk);
2885 	return skb;
2886 
2887 interrupted:
2888 	err = sock_intr_errno(timeo);
2889 failure:
2890 	*errcode = err;
2891 	return NULL;
2892 }
2893 EXPORT_SYMBOL(sock_alloc_send_pskb);
2894 
__sock_cmsg_send(struct sock * sk,struct cmsghdr * cmsg,struct sockcm_cookie * sockc)2895 int __sock_cmsg_send(struct sock *sk, struct cmsghdr *cmsg,
2896 		     struct sockcm_cookie *sockc)
2897 {
2898 	u32 tsflags;
2899 
2900 	BUILD_BUG_ON(SOF_TIMESTAMPING_LAST == (1 << 31));
2901 
2902 	switch (cmsg->cmsg_type) {
2903 	case SO_MARK:
2904 		if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_RAW) &&
2905 		    !ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
2906 			return -EPERM;
2907 		if (cmsg->cmsg_len != CMSG_LEN(sizeof(u32)))
2908 			return -EINVAL;
2909 		sockc->mark = *(u32 *)CMSG_DATA(cmsg);
2910 		break;
2911 	case SO_TIMESTAMPING_OLD:
2912 	case SO_TIMESTAMPING_NEW:
2913 		if (cmsg->cmsg_len != CMSG_LEN(sizeof(u32)))
2914 			return -EINVAL;
2915 
2916 		tsflags = *(u32 *)CMSG_DATA(cmsg);
2917 		if (tsflags & ~SOF_TIMESTAMPING_TX_RECORD_MASK)
2918 			return -EINVAL;
2919 
2920 		sockc->tsflags &= ~SOF_TIMESTAMPING_TX_RECORD_MASK;
2921 		sockc->tsflags |= tsflags;
2922 		break;
2923 	case SCM_TXTIME:
2924 		if (!sock_flag(sk, SOCK_TXTIME))
2925 			return -EINVAL;
2926 		if (cmsg->cmsg_len != CMSG_LEN(sizeof(u64)))
2927 			return -EINVAL;
2928 		sockc->transmit_time = get_unaligned((u64 *)CMSG_DATA(cmsg));
2929 		break;
2930 	case SCM_TS_OPT_ID:
2931 		if (sk_is_tcp(sk))
2932 			return -EINVAL;
2933 		tsflags = READ_ONCE(sk->sk_tsflags);
2934 		if (!(tsflags & SOF_TIMESTAMPING_OPT_ID))
2935 			return -EINVAL;
2936 		if (cmsg->cmsg_len != CMSG_LEN(sizeof(u32)))
2937 			return -EINVAL;
2938 		sockc->ts_opt_id = *(u32 *)CMSG_DATA(cmsg);
2939 		sockc->tsflags |= SOCKCM_FLAG_TS_OPT_ID;
2940 		break;
2941 	/* SCM_RIGHTS and SCM_CREDENTIALS are semantically in SOL_UNIX. */
2942 	case SCM_RIGHTS:
2943 	case SCM_CREDENTIALS:
2944 		break;
2945 	default:
2946 		return -EINVAL;
2947 	}
2948 	return 0;
2949 }
2950 EXPORT_SYMBOL(__sock_cmsg_send);
2951 
sock_cmsg_send(struct sock * sk,struct msghdr * msg,struct sockcm_cookie * sockc)2952 int sock_cmsg_send(struct sock *sk, struct msghdr *msg,
2953 		   struct sockcm_cookie *sockc)
2954 {
2955 	struct cmsghdr *cmsg;
2956 	int ret;
2957 
2958 	for_each_cmsghdr(cmsg, msg) {
2959 		if (!CMSG_OK(msg, cmsg))
2960 			return -EINVAL;
2961 		if (cmsg->cmsg_level != SOL_SOCKET)
2962 			continue;
2963 		ret = __sock_cmsg_send(sk, cmsg, sockc);
2964 		if (ret)
2965 			return ret;
2966 	}
2967 	return 0;
2968 }
2969 EXPORT_SYMBOL(sock_cmsg_send);
2970 
sk_enter_memory_pressure(struct sock * sk)2971 static void sk_enter_memory_pressure(struct sock *sk)
2972 {
2973 	if (!sk->sk_prot->enter_memory_pressure)
2974 		return;
2975 
2976 	sk->sk_prot->enter_memory_pressure(sk);
2977 }
2978 
sk_leave_memory_pressure(struct sock * sk)2979 static void sk_leave_memory_pressure(struct sock *sk)
2980 {
2981 	if (sk->sk_prot->leave_memory_pressure) {
2982 		INDIRECT_CALL_INET_1(sk->sk_prot->leave_memory_pressure,
2983 				     tcp_leave_memory_pressure, sk);
2984 	} else {
2985 		unsigned long *memory_pressure = sk->sk_prot->memory_pressure;
2986 
2987 		if (memory_pressure && READ_ONCE(*memory_pressure))
2988 			WRITE_ONCE(*memory_pressure, 0);
2989 	}
2990 }
2991 
2992 DEFINE_STATIC_KEY_FALSE(net_high_order_alloc_disable_key);
2993 
2994 /**
2995  * skb_page_frag_refill - check that a page_frag contains enough room
2996  * @sz: minimum size of the fragment we want to get
2997  * @pfrag: pointer to page_frag
2998  * @gfp: priority for memory allocation
2999  *
3000  * Note: While this allocator tries to use high order pages, there is
3001  * no guarantee that allocations succeed. Therefore, @sz MUST be
3002  * less or equal than PAGE_SIZE.
3003  */
skb_page_frag_refill(unsigned int sz,struct page_frag * pfrag,gfp_t gfp)3004 bool skb_page_frag_refill(unsigned int sz, struct page_frag *pfrag, gfp_t gfp)
3005 {
3006 	if (pfrag->page) {
3007 		if (page_ref_count(pfrag->page) == 1) {
3008 			pfrag->offset = 0;
3009 			return true;
3010 		}
3011 		if (pfrag->offset + sz <= pfrag->size)
3012 			return true;
3013 		put_page(pfrag->page);
3014 	}
3015 
3016 	pfrag->offset = 0;
3017 	if (SKB_FRAG_PAGE_ORDER &&
3018 	    !static_branch_unlikely(&net_high_order_alloc_disable_key)) {
3019 		/* Avoid direct reclaim but allow kswapd to wake */
3020 		pfrag->page = alloc_pages((gfp & ~__GFP_DIRECT_RECLAIM) |
3021 					  __GFP_COMP | __GFP_NOWARN |
3022 					  __GFP_NORETRY,
3023 					  SKB_FRAG_PAGE_ORDER);
3024 		if (likely(pfrag->page)) {
3025 			pfrag->size = PAGE_SIZE << SKB_FRAG_PAGE_ORDER;
3026 			return true;
3027 		}
3028 	}
3029 	pfrag->page = alloc_page(gfp);
3030 	if (likely(pfrag->page)) {
3031 		pfrag->size = PAGE_SIZE;
3032 		return true;
3033 	}
3034 	return false;
3035 }
3036 EXPORT_SYMBOL(skb_page_frag_refill);
3037 
sk_page_frag_refill(struct sock * sk,struct page_frag * pfrag)3038 bool sk_page_frag_refill(struct sock *sk, struct page_frag *pfrag)
3039 {
3040 	if (likely(skb_page_frag_refill(32U, pfrag, sk->sk_allocation)))
3041 		return true;
3042 
3043 	sk_enter_memory_pressure(sk);
3044 	sk_stream_moderate_sndbuf(sk);
3045 	return false;
3046 }
3047 EXPORT_SYMBOL(sk_page_frag_refill);
3048 
__lock_sock(struct sock * sk)3049 void __lock_sock(struct sock *sk)
3050 	__releases(&sk->sk_lock.slock)
3051 	__acquires(&sk->sk_lock.slock)
3052 {
3053 	DEFINE_WAIT(wait);
3054 
3055 	for (;;) {
3056 		prepare_to_wait_exclusive(&sk->sk_lock.wq, &wait,
3057 					TASK_UNINTERRUPTIBLE);
3058 		spin_unlock_bh(&sk->sk_lock.slock);
3059 		schedule();
3060 		spin_lock_bh(&sk->sk_lock.slock);
3061 		if (!sock_owned_by_user(sk))
3062 			break;
3063 	}
3064 	finish_wait(&sk->sk_lock.wq, &wait);
3065 }
3066 
__release_sock(struct sock * sk)3067 void __release_sock(struct sock *sk)
3068 	__releases(&sk->sk_lock.slock)
3069 	__acquires(&sk->sk_lock.slock)
3070 {
3071 	struct sk_buff *skb, *next;
3072 
3073 	while ((skb = sk->sk_backlog.head) != NULL) {
3074 		sk->sk_backlog.head = sk->sk_backlog.tail = NULL;
3075 
3076 		spin_unlock_bh(&sk->sk_lock.slock);
3077 
3078 		do {
3079 			next = skb->next;
3080 			prefetch(next);
3081 			DEBUG_NET_WARN_ON_ONCE(skb_dst_is_noref(skb));
3082 			skb_mark_not_on_list(skb);
3083 			sk_backlog_rcv(sk, skb);
3084 
3085 			cond_resched();
3086 
3087 			skb = next;
3088 		} while (skb != NULL);
3089 
3090 		spin_lock_bh(&sk->sk_lock.slock);
3091 	}
3092 
3093 	/*
3094 	 * Doing the zeroing here guarantee we can not loop forever
3095 	 * while a wild producer attempts to flood us.
3096 	 */
3097 	sk->sk_backlog.len = 0;
3098 }
3099 
__sk_flush_backlog(struct sock * sk)3100 void __sk_flush_backlog(struct sock *sk)
3101 {
3102 	spin_lock_bh(&sk->sk_lock.slock);
3103 	__release_sock(sk);
3104 
3105 	if (sk->sk_prot->release_cb)
3106 		INDIRECT_CALL_INET_1(sk->sk_prot->release_cb,
3107 				     tcp_release_cb, sk);
3108 
3109 	spin_unlock_bh(&sk->sk_lock.slock);
3110 }
3111 EXPORT_SYMBOL_GPL(__sk_flush_backlog);
3112 
3113 /**
3114  * sk_wait_data - wait for data to arrive at sk_receive_queue
3115  * @sk:    sock to wait on
3116  * @timeo: for how long
3117  * @skb:   last skb seen on sk_receive_queue
3118  *
3119  * Now socket state including sk->sk_err is changed only under lock,
3120  * hence we may omit checks after joining wait queue.
3121  * We check receive queue before schedule() only as optimization;
3122  * it is very likely that release_sock() added new data.
3123  */
sk_wait_data(struct sock * sk,long * timeo,const struct sk_buff * skb)3124 int sk_wait_data(struct sock *sk, long *timeo, const struct sk_buff *skb)
3125 {
3126 	DEFINE_WAIT_FUNC(wait, woken_wake_function);
3127 	int rc;
3128 
3129 	add_wait_queue(sk_sleep(sk), &wait);
3130 	sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
3131 	rc = sk_wait_event(sk, timeo, skb_peek_tail(&sk->sk_receive_queue) != skb, &wait);
3132 	sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
3133 	remove_wait_queue(sk_sleep(sk), &wait);
3134 	return rc;
3135 }
3136 EXPORT_SYMBOL(sk_wait_data);
3137 
3138 /**
3139  *	__sk_mem_raise_allocated - increase memory_allocated
3140  *	@sk: socket
3141  *	@size: memory size to allocate
3142  *	@amt: pages to allocate
3143  *	@kind: allocation type
3144  *
3145  *	Similar to __sk_mem_schedule(), but does not update sk_forward_alloc.
3146  *
3147  *	Unlike the globally shared limits among the sockets under same protocol,
3148  *	consuming the budget of a memcg won't have direct effect on other ones.
3149  *	So be optimistic about memcg's tolerance, and leave the callers to decide
3150  *	whether or not to raise allocated through sk_under_memory_pressure() or
3151  *	its variants.
3152  */
__sk_mem_raise_allocated(struct sock * sk,int size,int amt,int kind)3153 int __sk_mem_raise_allocated(struct sock *sk, int size, int amt, int kind)
3154 {
3155 	struct mem_cgroup *memcg = mem_cgroup_sockets_enabled ? sk->sk_memcg : NULL;
3156 	struct proto *prot = sk->sk_prot;
3157 	bool charged = false;
3158 	long allocated;
3159 
3160 	sk_memory_allocated_add(sk, amt);
3161 	allocated = sk_memory_allocated(sk);
3162 
3163 	if (memcg) {
3164 		if (!mem_cgroup_charge_skmem(memcg, amt, gfp_memcg_charge()))
3165 			goto suppress_allocation;
3166 		charged = true;
3167 	}
3168 
3169 	/* Under limit. */
3170 	if (allocated <= sk_prot_mem_limits(sk, 0)) {
3171 		sk_leave_memory_pressure(sk);
3172 		return 1;
3173 	}
3174 
3175 	/* Under pressure. */
3176 	if (allocated > sk_prot_mem_limits(sk, 1))
3177 		sk_enter_memory_pressure(sk);
3178 
3179 	/* Over hard limit. */
3180 	if (allocated > sk_prot_mem_limits(sk, 2))
3181 		goto suppress_allocation;
3182 
3183 	/* Guarantee minimum buffer size under pressure (either global
3184 	 * or memcg) to make sure features described in RFC 7323 (TCP
3185 	 * Extensions for High Performance) work properly.
3186 	 *
3187 	 * This rule does NOT stand when exceeds global or memcg's hard
3188 	 * limit, or else a DoS attack can be taken place by spawning
3189 	 * lots of sockets whose usage are under minimum buffer size.
3190 	 */
3191 	if (kind == SK_MEM_RECV) {
3192 		if (atomic_read(&sk->sk_rmem_alloc) < sk_get_rmem0(sk, prot))
3193 			return 1;
3194 
3195 	} else { /* SK_MEM_SEND */
3196 		int wmem0 = sk_get_wmem0(sk, prot);
3197 
3198 		if (sk->sk_type == SOCK_STREAM) {
3199 			if (sk->sk_wmem_queued < wmem0)
3200 				return 1;
3201 		} else if (refcount_read(&sk->sk_wmem_alloc) < wmem0) {
3202 				return 1;
3203 		}
3204 	}
3205 
3206 	if (sk_has_memory_pressure(sk)) {
3207 		u64 alloc;
3208 
3209 		/* The following 'average' heuristic is within the
3210 		 * scope of global accounting, so it only makes
3211 		 * sense for global memory pressure.
3212 		 */
3213 		if (!sk_under_global_memory_pressure(sk))
3214 			return 1;
3215 
3216 		/* Try to be fair among all the sockets under global
3217 		 * pressure by allowing the ones that below average
3218 		 * usage to raise.
3219 		 */
3220 		alloc = sk_sockets_allocated_read_positive(sk);
3221 		if (sk_prot_mem_limits(sk, 2) > alloc *
3222 		    sk_mem_pages(sk->sk_wmem_queued +
3223 				 atomic_read(&sk->sk_rmem_alloc) +
3224 				 sk->sk_forward_alloc))
3225 			return 1;
3226 	}
3227 
3228 suppress_allocation:
3229 
3230 	if (kind == SK_MEM_SEND && sk->sk_type == SOCK_STREAM) {
3231 		sk_stream_moderate_sndbuf(sk);
3232 
3233 		/* Fail only if socket is _under_ its sndbuf.
3234 		 * In this case we cannot block, so that we have to fail.
3235 		 */
3236 		if (sk->sk_wmem_queued + size >= sk->sk_sndbuf) {
3237 			/* Force charge with __GFP_NOFAIL */
3238 			if (memcg && !charged) {
3239 				mem_cgroup_charge_skmem(memcg, amt,
3240 					gfp_memcg_charge() | __GFP_NOFAIL);
3241 			}
3242 			return 1;
3243 		}
3244 	}
3245 
3246 	if (kind == SK_MEM_SEND || (kind == SK_MEM_RECV && charged))
3247 		trace_sock_exceed_buf_limit(sk, prot, allocated, kind);
3248 
3249 	sk_memory_allocated_sub(sk, amt);
3250 
3251 	if (charged)
3252 		mem_cgroup_uncharge_skmem(memcg, amt);
3253 
3254 	return 0;
3255 }
3256 
3257 /**
3258  *	__sk_mem_schedule - increase sk_forward_alloc and memory_allocated
3259  *	@sk: socket
3260  *	@size: memory size to allocate
3261  *	@kind: allocation type
3262  *
3263  *	If kind is SK_MEM_SEND, it means wmem allocation. Otherwise it means
3264  *	rmem allocation. This function assumes that protocols which have
3265  *	memory_pressure use sk_wmem_queued as write buffer accounting.
3266  */
__sk_mem_schedule(struct sock * sk,int size,int kind)3267 int __sk_mem_schedule(struct sock *sk, int size, int kind)
3268 {
3269 	int ret, amt = sk_mem_pages(size);
3270 
3271 	sk_forward_alloc_add(sk, amt << PAGE_SHIFT);
3272 	ret = __sk_mem_raise_allocated(sk, size, amt, kind);
3273 	if (!ret)
3274 		sk_forward_alloc_add(sk, -(amt << PAGE_SHIFT));
3275 	return ret;
3276 }
3277 EXPORT_SYMBOL(__sk_mem_schedule);
3278 
3279 /**
3280  *	__sk_mem_reduce_allocated - reclaim memory_allocated
3281  *	@sk: socket
3282  *	@amount: number of quanta
3283  *
3284  *	Similar to __sk_mem_reclaim(), but does not update sk_forward_alloc
3285  */
__sk_mem_reduce_allocated(struct sock * sk,int amount)3286 void __sk_mem_reduce_allocated(struct sock *sk, int amount)
3287 {
3288 	sk_memory_allocated_sub(sk, amount);
3289 
3290 	if (mem_cgroup_sockets_enabled && sk->sk_memcg)
3291 		mem_cgroup_uncharge_skmem(sk->sk_memcg, amount);
3292 
3293 	if (sk_under_global_memory_pressure(sk) &&
3294 	    (sk_memory_allocated(sk) < sk_prot_mem_limits(sk, 0)))
3295 		sk_leave_memory_pressure(sk);
3296 }
3297 
3298 /**
3299  *	__sk_mem_reclaim - reclaim sk_forward_alloc and memory_allocated
3300  *	@sk: socket
3301  *	@amount: number of bytes (rounded down to a PAGE_SIZE multiple)
3302  */
__sk_mem_reclaim(struct sock * sk,int amount)3303 void __sk_mem_reclaim(struct sock *sk, int amount)
3304 {
3305 	amount >>= PAGE_SHIFT;
3306 	sk_forward_alloc_add(sk, -(amount << PAGE_SHIFT));
3307 	__sk_mem_reduce_allocated(sk, amount);
3308 }
3309 EXPORT_SYMBOL(__sk_mem_reclaim);
3310 
sk_set_peek_off(struct sock * sk,int val)3311 int sk_set_peek_off(struct sock *sk, int val)
3312 {
3313 	WRITE_ONCE(sk->sk_peek_off, val);
3314 	return 0;
3315 }
3316 EXPORT_SYMBOL_GPL(sk_set_peek_off);
3317 
3318 /*
3319  * Set of default routines for initialising struct proto_ops when
3320  * the protocol does not support a particular function. In certain
3321  * cases where it makes no sense for a protocol to have a "do nothing"
3322  * function, some default processing is provided.
3323  */
3324 
sock_no_bind(struct socket * sock,struct sockaddr * saddr,int len)3325 int sock_no_bind(struct socket *sock, struct sockaddr *saddr, int len)
3326 {
3327 	return -EOPNOTSUPP;
3328 }
3329 EXPORT_SYMBOL(sock_no_bind);
3330 
sock_no_connect(struct socket * sock,struct sockaddr * saddr,int len,int flags)3331 int sock_no_connect(struct socket *sock, struct sockaddr *saddr,
3332 		    int len, int flags)
3333 {
3334 	return -EOPNOTSUPP;
3335 }
3336 EXPORT_SYMBOL(sock_no_connect);
3337 
sock_no_socketpair(struct socket * sock1,struct socket * sock2)3338 int sock_no_socketpair(struct socket *sock1, struct socket *sock2)
3339 {
3340 	return -EOPNOTSUPP;
3341 }
3342 EXPORT_SYMBOL(sock_no_socketpair);
3343 
sock_no_accept(struct socket * sock,struct socket * newsock,struct proto_accept_arg * arg)3344 int sock_no_accept(struct socket *sock, struct socket *newsock,
3345 		   struct proto_accept_arg *arg)
3346 {
3347 	return -EOPNOTSUPP;
3348 }
3349 EXPORT_SYMBOL(sock_no_accept);
3350 
sock_no_getname(struct socket * sock,struct sockaddr * saddr,int peer)3351 int sock_no_getname(struct socket *sock, struct sockaddr *saddr,
3352 		    int peer)
3353 {
3354 	return -EOPNOTSUPP;
3355 }
3356 EXPORT_SYMBOL(sock_no_getname);
3357 
sock_no_ioctl(struct socket * sock,unsigned int cmd,unsigned long arg)3358 int sock_no_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
3359 {
3360 	return -EOPNOTSUPP;
3361 }
3362 EXPORT_SYMBOL(sock_no_ioctl);
3363 
sock_no_listen(struct socket * sock,int backlog)3364 int sock_no_listen(struct socket *sock, int backlog)
3365 {
3366 	return -EOPNOTSUPP;
3367 }
3368 EXPORT_SYMBOL(sock_no_listen);
3369 
sock_no_shutdown(struct socket * sock,int how)3370 int sock_no_shutdown(struct socket *sock, int how)
3371 {
3372 	return -EOPNOTSUPP;
3373 }
3374 EXPORT_SYMBOL(sock_no_shutdown);
3375 
sock_no_sendmsg(struct socket * sock,struct msghdr * m,size_t len)3376 int sock_no_sendmsg(struct socket *sock, struct msghdr *m, size_t len)
3377 {
3378 	return -EOPNOTSUPP;
3379 }
3380 EXPORT_SYMBOL(sock_no_sendmsg);
3381 
sock_no_sendmsg_locked(struct sock * sk,struct msghdr * m,size_t len)3382 int sock_no_sendmsg_locked(struct sock *sk, struct msghdr *m, size_t len)
3383 {
3384 	return -EOPNOTSUPP;
3385 }
3386 EXPORT_SYMBOL(sock_no_sendmsg_locked);
3387 
sock_no_recvmsg(struct socket * sock,struct msghdr * m,size_t len,int flags)3388 int sock_no_recvmsg(struct socket *sock, struct msghdr *m, size_t len,
3389 		    int flags)
3390 {
3391 	return -EOPNOTSUPP;
3392 }
3393 EXPORT_SYMBOL(sock_no_recvmsg);
3394 
sock_no_mmap(struct file * file,struct socket * sock,struct vm_area_struct * vma)3395 int sock_no_mmap(struct file *file, struct socket *sock, struct vm_area_struct *vma)
3396 {
3397 	/* Mirror missing mmap method error code */
3398 	return -ENODEV;
3399 }
3400 EXPORT_SYMBOL(sock_no_mmap);
3401 
3402 /*
3403  * When a file is received (via SCM_RIGHTS, etc), we must bump the
3404  * various sock-based usage counts.
3405  */
__receive_sock(struct file * file)3406 void __receive_sock(struct file *file)
3407 {
3408 	struct socket *sock;
3409 
3410 	sock = sock_from_file(file);
3411 	if (sock) {
3412 		sock_update_netprioidx(&sock->sk->sk_cgrp_data);
3413 		sock_update_classid(&sock->sk->sk_cgrp_data);
3414 	}
3415 }
3416 
3417 /*
3418  *	Default Socket Callbacks
3419  */
3420 
sock_def_wakeup(struct sock * sk)3421 static void sock_def_wakeup(struct sock *sk)
3422 {
3423 	struct socket_wq *wq;
3424 
3425 	rcu_read_lock();
3426 	wq = rcu_dereference(sk->sk_wq);
3427 	if (skwq_has_sleeper(wq))
3428 		wake_up_interruptible_all(&wq->wait);
3429 	rcu_read_unlock();
3430 }
3431 
sock_def_error_report(struct sock * sk)3432 static void sock_def_error_report(struct sock *sk)
3433 {
3434 	struct socket_wq *wq;
3435 
3436 	rcu_read_lock();
3437 	wq = rcu_dereference(sk->sk_wq);
3438 	if (skwq_has_sleeper(wq))
3439 		wake_up_interruptible_poll(&wq->wait, EPOLLERR);
3440 	sk_wake_async_rcu(sk, SOCK_WAKE_IO, POLL_ERR);
3441 	rcu_read_unlock();
3442 }
3443 
sock_def_readable(struct sock * sk)3444 void sock_def_readable(struct sock *sk)
3445 {
3446 	struct socket_wq *wq;
3447 
3448 	trace_sk_data_ready(sk);
3449 
3450 	rcu_read_lock();
3451 	wq = rcu_dereference(sk->sk_wq);
3452 	if (skwq_has_sleeper(wq))
3453 		wake_up_interruptible_sync_poll(&wq->wait, EPOLLIN | EPOLLPRI |
3454 						EPOLLRDNORM | EPOLLRDBAND);
3455 	sk_wake_async_rcu(sk, SOCK_WAKE_WAITD, POLL_IN);
3456 	rcu_read_unlock();
3457 }
3458 
sock_def_write_space(struct sock * sk)3459 static void sock_def_write_space(struct sock *sk)
3460 {
3461 	struct socket_wq *wq;
3462 
3463 	rcu_read_lock();
3464 
3465 	/* Do not wake up a writer until he can make "significant"
3466 	 * progress.  --DaveM
3467 	 */
3468 	if (sock_writeable(sk)) {
3469 		wq = rcu_dereference(sk->sk_wq);
3470 		if (skwq_has_sleeper(wq))
3471 			wake_up_interruptible_sync_poll(&wq->wait, EPOLLOUT |
3472 						EPOLLWRNORM | EPOLLWRBAND);
3473 
3474 		/* Should agree with poll, otherwise some programs break */
3475 		sk_wake_async_rcu(sk, SOCK_WAKE_SPACE, POLL_OUT);
3476 	}
3477 
3478 	rcu_read_unlock();
3479 }
3480 
3481 /* An optimised version of sock_def_write_space(), should only be called
3482  * for SOCK_RCU_FREE sockets under RCU read section and after putting
3483  * ->sk_wmem_alloc.
3484  */
sock_def_write_space_wfree(struct sock * sk)3485 static void sock_def_write_space_wfree(struct sock *sk)
3486 {
3487 	/* Do not wake up a writer until he can make "significant"
3488 	 * progress.  --DaveM
3489 	 */
3490 	if (sock_writeable(sk)) {
3491 		struct socket_wq *wq = rcu_dereference(sk->sk_wq);
3492 
3493 		/* rely on refcount_sub from sock_wfree() */
3494 		smp_mb__after_atomic();
3495 		if (wq && waitqueue_active(&wq->wait))
3496 			wake_up_interruptible_sync_poll(&wq->wait, EPOLLOUT |
3497 						EPOLLWRNORM | EPOLLWRBAND);
3498 
3499 		/* Should agree with poll, otherwise some programs break */
3500 		sk_wake_async_rcu(sk, SOCK_WAKE_SPACE, POLL_OUT);
3501 	}
3502 }
3503 
sock_def_destruct(struct sock * sk)3504 static void sock_def_destruct(struct sock *sk)
3505 {
3506 }
3507 
sk_send_sigurg(struct sock * sk)3508 void sk_send_sigurg(struct sock *sk)
3509 {
3510 	if (sk->sk_socket && sk->sk_socket->file)
3511 		if (send_sigurg(sk->sk_socket->file))
3512 			sk_wake_async(sk, SOCK_WAKE_URG, POLL_PRI);
3513 }
3514 EXPORT_SYMBOL(sk_send_sigurg);
3515 
sk_reset_timer(struct sock * sk,struct timer_list * timer,unsigned long expires)3516 void sk_reset_timer(struct sock *sk, struct timer_list* timer,
3517 		    unsigned long expires)
3518 {
3519 	if (!mod_timer(timer, expires))
3520 		sock_hold(sk);
3521 }
3522 EXPORT_SYMBOL(sk_reset_timer);
3523 
sk_stop_timer(struct sock * sk,struct timer_list * timer)3524 void sk_stop_timer(struct sock *sk, struct timer_list* timer)
3525 {
3526 	if (del_timer(timer))
3527 		__sock_put(sk);
3528 }
3529 EXPORT_SYMBOL(sk_stop_timer);
3530 
sk_stop_timer_sync(struct sock * sk,struct timer_list * timer)3531 void sk_stop_timer_sync(struct sock *sk, struct timer_list *timer)
3532 {
3533 	if (del_timer_sync(timer))
3534 		__sock_put(sk);
3535 }
3536 EXPORT_SYMBOL(sk_stop_timer_sync);
3537 
sock_init_data_uid(struct socket * sock,struct sock * sk,kuid_t uid)3538 void sock_init_data_uid(struct socket *sock, struct sock *sk, kuid_t uid)
3539 {
3540 	sk_init_common(sk);
3541 	sk->sk_send_head	=	NULL;
3542 
3543 	timer_setup(&sk->sk_timer, NULL, 0);
3544 
3545 	sk->sk_allocation	=	GFP_KERNEL;
3546 	sk->sk_rcvbuf		=	READ_ONCE(sysctl_rmem_default);
3547 	sk->sk_sndbuf		=	READ_ONCE(sysctl_wmem_default);
3548 	sk->sk_state		=	TCP_CLOSE;
3549 	sk->sk_use_task_frag	=	true;
3550 	sk_set_socket(sk, sock);
3551 
3552 	sock_set_flag(sk, SOCK_ZAPPED);
3553 
3554 	if (sock) {
3555 		sk->sk_type	=	sock->type;
3556 		RCU_INIT_POINTER(sk->sk_wq, &sock->wq);
3557 		sock->sk	=	sk;
3558 	} else {
3559 		RCU_INIT_POINTER(sk->sk_wq, NULL);
3560 	}
3561 	sk->sk_uid	=	uid;
3562 
3563 	sk->sk_state_change	=	sock_def_wakeup;
3564 	sk->sk_data_ready	=	sock_def_readable;
3565 	sk->sk_write_space	=	sock_def_write_space;
3566 	sk->sk_error_report	=	sock_def_error_report;
3567 	sk->sk_destruct		=	sock_def_destruct;
3568 
3569 	sk->sk_frag.page	=	NULL;
3570 	sk->sk_frag.offset	=	0;
3571 	sk->sk_peek_off		=	-1;
3572 
3573 	sk->sk_peer_pid 	=	NULL;
3574 	sk->sk_peer_cred	=	NULL;
3575 	spin_lock_init(&sk->sk_peer_lock);
3576 
3577 	sk->sk_write_pending	=	0;
3578 	sk->sk_rcvlowat		=	1;
3579 	sk->sk_rcvtimeo		=	MAX_SCHEDULE_TIMEOUT;
3580 	sk->sk_sndtimeo		=	MAX_SCHEDULE_TIMEOUT;
3581 
3582 	sk->sk_stamp = SK_DEFAULT_STAMP;
3583 #if BITS_PER_LONG==32
3584 	seqlock_init(&sk->sk_stamp_seq);
3585 #endif
3586 	atomic_set(&sk->sk_zckey, 0);
3587 
3588 #ifdef CONFIG_NET_RX_BUSY_POLL
3589 	sk->sk_napi_id		=	0;
3590 	sk->sk_ll_usec		=	READ_ONCE(sysctl_net_busy_read);
3591 #endif
3592 
3593 	sk->sk_max_pacing_rate = ~0UL;
3594 	sk->sk_pacing_rate = ~0UL;
3595 	WRITE_ONCE(sk->sk_pacing_shift, 10);
3596 	sk->sk_incoming_cpu = -1;
3597 
3598 	sk_rx_queue_clear(sk);
3599 	/*
3600 	 * Before updating sk_refcnt, we must commit prior changes to memory
3601 	 * (Documentation/RCU/rculist_nulls.rst for details)
3602 	 */
3603 	smp_wmb();
3604 	refcount_set(&sk->sk_refcnt, 1);
3605 	atomic_set(&sk->sk_drops, 0);
3606 }
3607 EXPORT_SYMBOL(sock_init_data_uid);
3608 
sock_init_data(struct socket * sock,struct sock * sk)3609 void sock_init_data(struct socket *sock, struct sock *sk)
3610 {
3611 	kuid_t uid = sock ?
3612 		SOCK_INODE(sock)->i_uid :
3613 		make_kuid(sock_net(sk)->user_ns, 0);
3614 
3615 	sock_init_data_uid(sock, sk, uid);
3616 }
3617 EXPORT_SYMBOL(sock_init_data);
3618 
lock_sock_nested(struct sock * sk,int subclass)3619 void lock_sock_nested(struct sock *sk, int subclass)
3620 {
3621 	/* The sk_lock has mutex_lock() semantics here. */
3622 	mutex_acquire(&sk->sk_lock.dep_map, subclass, 0, _RET_IP_);
3623 
3624 	might_sleep();
3625 	spin_lock_bh(&sk->sk_lock.slock);
3626 	if (sock_owned_by_user_nocheck(sk))
3627 		__lock_sock(sk);
3628 	sk->sk_lock.owned = 1;
3629 	spin_unlock_bh(&sk->sk_lock.slock);
3630 }
3631 EXPORT_SYMBOL(lock_sock_nested);
3632 
release_sock(struct sock * sk)3633 void release_sock(struct sock *sk)
3634 {
3635 	spin_lock_bh(&sk->sk_lock.slock);
3636 	if (sk->sk_backlog.tail)
3637 		__release_sock(sk);
3638 
3639 	if (sk->sk_prot->release_cb)
3640 		INDIRECT_CALL_INET_1(sk->sk_prot->release_cb,
3641 				     tcp_release_cb, sk);
3642 
3643 	sock_release_ownership(sk);
3644 	if (waitqueue_active(&sk->sk_lock.wq))
3645 		wake_up(&sk->sk_lock.wq);
3646 	spin_unlock_bh(&sk->sk_lock.slock);
3647 }
3648 EXPORT_SYMBOL(release_sock);
3649 
__lock_sock_fast(struct sock * sk)3650 bool __lock_sock_fast(struct sock *sk) __acquires(&sk->sk_lock.slock)
3651 {
3652 	might_sleep();
3653 	spin_lock_bh(&sk->sk_lock.slock);
3654 
3655 	if (!sock_owned_by_user_nocheck(sk)) {
3656 		/*
3657 		 * Fast path return with bottom halves disabled and
3658 		 * sock::sk_lock.slock held.
3659 		 *
3660 		 * The 'mutex' is not contended and holding
3661 		 * sock::sk_lock.slock prevents all other lockers to
3662 		 * proceed so the corresponding unlock_sock_fast() can
3663 		 * avoid the slow path of release_sock() completely and
3664 		 * just release slock.
3665 		 *
3666 		 * From a semantical POV this is equivalent to 'acquiring'
3667 		 * the 'mutex', hence the corresponding lockdep
3668 		 * mutex_release() has to happen in the fast path of
3669 		 * unlock_sock_fast().
3670 		 */
3671 		return false;
3672 	}
3673 
3674 	__lock_sock(sk);
3675 	sk->sk_lock.owned = 1;
3676 	__acquire(&sk->sk_lock.slock);
3677 	spin_unlock_bh(&sk->sk_lock.slock);
3678 	return true;
3679 }
3680 EXPORT_SYMBOL(__lock_sock_fast);
3681 
sock_gettstamp(struct socket * sock,void __user * userstamp,bool timeval,bool time32)3682 int sock_gettstamp(struct socket *sock, void __user *userstamp,
3683 		   bool timeval, bool time32)
3684 {
3685 	struct sock *sk = sock->sk;
3686 	struct timespec64 ts;
3687 
3688 	sock_enable_timestamp(sk, SOCK_TIMESTAMP);
3689 	ts = ktime_to_timespec64(sock_read_timestamp(sk));
3690 	if (ts.tv_sec == -1)
3691 		return -ENOENT;
3692 	if (ts.tv_sec == 0) {
3693 		ktime_t kt = ktime_get_real();
3694 		sock_write_timestamp(sk, kt);
3695 		ts = ktime_to_timespec64(kt);
3696 	}
3697 
3698 	if (timeval)
3699 		ts.tv_nsec /= 1000;
3700 
3701 #ifdef CONFIG_COMPAT_32BIT_TIME
3702 	if (time32)
3703 		return put_old_timespec32(&ts, userstamp);
3704 #endif
3705 #ifdef CONFIG_SPARC64
3706 	/* beware of padding in sparc64 timeval */
3707 	if (timeval && !in_compat_syscall()) {
3708 		struct __kernel_old_timeval __user tv = {
3709 			.tv_sec = ts.tv_sec,
3710 			.tv_usec = ts.tv_nsec,
3711 		};
3712 		if (copy_to_user(userstamp, &tv, sizeof(tv)))
3713 			return -EFAULT;
3714 		return 0;
3715 	}
3716 #endif
3717 	return put_timespec64(&ts, userstamp);
3718 }
3719 EXPORT_SYMBOL(sock_gettstamp);
3720 
sock_enable_timestamp(struct sock * sk,enum sock_flags flag)3721 void sock_enable_timestamp(struct sock *sk, enum sock_flags flag)
3722 {
3723 	if (!sock_flag(sk, flag)) {
3724 		unsigned long previous_flags = sk->sk_flags;
3725 
3726 		sock_set_flag(sk, flag);
3727 		/*
3728 		 * we just set one of the two flags which require net
3729 		 * time stamping, but time stamping might have been on
3730 		 * already because of the other one
3731 		 */
3732 		if (sock_needs_netstamp(sk) &&
3733 		    !(previous_flags & SK_FLAGS_TIMESTAMP))
3734 			net_enable_timestamp();
3735 	}
3736 }
3737 
sock_recv_errqueue(struct sock * sk,struct msghdr * msg,int len,int level,int type)3738 int sock_recv_errqueue(struct sock *sk, struct msghdr *msg, int len,
3739 		       int level, int type)
3740 {
3741 	struct sock_exterr_skb *serr;
3742 	struct sk_buff *skb;
3743 	int copied, err;
3744 
3745 	err = -EAGAIN;
3746 	skb = sock_dequeue_err_skb(sk);
3747 	if (skb == NULL)
3748 		goto out;
3749 
3750 	copied = skb->len;
3751 	if (copied > len) {
3752 		msg->msg_flags |= MSG_TRUNC;
3753 		copied = len;
3754 	}
3755 	err = skb_copy_datagram_msg(skb, 0, msg, copied);
3756 	if (err)
3757 		goto out_free_skb;
3758 
3759 	sock_recv_timestamp(msg, sk, skb);
3760 
3761 	serr = SKB_EXT_ERR(skb);
3762 	put_cmsg(msg, level, type, sizeof(serr->ee), &serr->ee);
3763 
3764 	msg->msg_flags |= MSG_ERRQUEUE;
3765 	err = copied;
3766 
3767 out_free_skb:
3768 	kfree_skb(skb);
3769 out:
3770 	return err;
3771 }
3772 EXPORT_SYMBOL(sock_recv_errqueue);
3773 
3774 /*
3775  *	Get a socket option on an socket.
3776  *
3777  *	FIX: POSIX 1003.1g is very ambiguous here. It states that
3778  *	asynchronous errors should be reported by getsockopt. We assume
3779  *	this means if you specify SO_ERROR (otherwise what is the point of it).
3780  */
sock_common_getsockopt(struct socket * sock,int level,int optname,char __user * optval,int __user * optlen)3781 int sock_common_getsockopt(struct socket *sock, int level, int optname,
3782 			   char __user *optval, int __user *optlen)
3783 {
3784 	struct sock *sk = sock->sk;
3785 
3786 	/* IPV6_ADDRFORM can change sk->sk_prot under us. */
3787 	return READ_ONCE(sk->sk_prot)->getsockopt(sk, level, optname, optval, optlen);
3788 }
3789 EXPORT_SYMBOL(sock_common_getsockopt);
3790 
sock_common_recvmsg(struct socket * sock,struct msghdr * msg,size_t size,int flags)3791 int sock_common_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
3792 			int flags)
3793 {
3794 	struct sock *sk = sock->sk;
3795 	int addr_len = 0;
3796 	int err;
3797 
3798 	err = sk->sk_prot->recvmsg(sk, msg, size, flags, &addr_len);
3799 	if (err >= 0)
3800 		msg->msg_namelen = addr_len;
3801 	return err;
3802 }
3803 EXPORT_SYMBOL(sock_common_recvmsg);
3804 
3805 /*
3806  *	Set socket options on an inet socket.
3807  */
sock_common_setsockopt(struct socket * sock,int level,int optname,sockptr_t optval,unsigned int optlen)3808 int sock_common_setsockopt(struct socket *sock, int level, int optname,
3809 			   sockptr_t optval, unsigned int optlen)
3810 {
3811 	struct sock *sk = sock->sk;
3812 
3813 	/* IPV6_ADDRFORM can change sk->sk_prot under us. */
3814 	return READ_ONCE(sk->sk_prot)->setsockopt(sk, level, optname, optval, optlen);
3815 }
3816 EXPORT_SYMBOL(sock_common_setsockopt);
3817 
sk_common_release(struct sock * sk)3818 void sk_common_release(struct sock *sk)
3819 {
3820 	if (sk->sk_prot->destroy)
3821 		sk->sk_prot->destroy(sk);
3822 
3823 	/*
3824 	 * Observation: when sk_common_release is called, processes have
3825 	 * no access to socket. But net still has.
3826 	 * Step one, detach it from networking:
3827 	 *
3828 	 * A. Remove from hash tables.
3829 	 */
3830 
3831 	sk->sk_prot->unhash(sk);
3832 
3833 	/*
3834 	 * In this point socket cannot receive new packets, but it is possible
3835 	 * that some packets are in flight because some CPU runs receiver and
3836 	 * did hash table lookup before we unhashed socket. They will achieve
3837 	 * receive queue and will be purged by socket destructor.
3838 	 *
3839 	 * Also we still have packets pending on receive queue and probably,
3840 	 * our own packets waiting in device queues. sock_destroy will drain
3841 	 * receive queue, but transmitted packets will delay socket destruction
3842 	 * until the last reference will be released.
3843 	 */
3844 
3845 	sock_orphan(sk);
3846 
3847 	xfrm_sk_free_policy(sk);
3848 
3849 	sock_put(sk);
3850 }
3851 EXPORT_SYMBOL(sk_common_release);
3852 
sk_get_meminfo(const struct sock * sk,u32 * mem)3853 void sk_get_meminfo(const struct sock *sk, u32 *mem)
3854 {
3855 	memset(mem, 0, sizeof(*mem) * SK_MEMINFO_VARS);
3856 
3857 	mem[SK_MEMINFO_RMEM_ALLOC] = sk_rmem_alloc_get(sk);
3858 	mem[SK_MEMINFO_RCVBUF] = READ_ONCE(sk->sk_rcvbuf);
3859 	mem[SK_MEMINFO_WMEM_ALLOC] = sk_wmem_alloc_get(sk);
3860 	mem[SK_MEMINFO_SNDBUF] = READ_ONCE(sk->sk_sndbuf);
3861 	mem[SK_MEMINFO_FWD_ALLOC] = sk_forward_alloc_get(sk);
3862 	mem[SK_MEMINFO_WMEM_QUEUED] = READ_ONCE(sk->sk_wmem_queued);
3863 	mem[SK_MEMINFO_OPTMEM] = atomic_read(&sk->sk_omem_alloc);
3864 	mem[SK_MEMINFO_BACKLOG] = READ_ONCE(sk->sk_backlog.len);
3865 	mem[SK_MEMINFO_DROPS] = atomic_read(&sk->sk_drops);
3866 }
3867 
3868 #ifdef CONFIG_PROC_FS
3869 static DECLARE_BITMAP(proto_inuse_idx, PROTO_INUSE_NR);
3870 
sock_prot_inuse_get(struct net * net,struct proto * prot)3871 int sock_prot_inuse_get(struct net *net, struct proto *prot)
3872 {
3873 	int cpu, idx = prot->inuse_idx;
3874 	int res = 0;
3875 
3876 	for_each_possible_cpu(cpu)
3877 		res += per_cpu_ptr(net->core.prot_inuse, cpu)->val[idx];
3878 
3879 	return res >= 0 ? res : 0;
3880 }
3881 EXPORT_SYMBOL_GPL(sock_prot_inuse_get);
3882 
sock_inuse_get(struct net * net)3883 int sock_inuse_get(struct net *net)
3884 {
3885 	int cpu, res = 0;
3886 
3887 	for_each_possible_cpu(cpu)
3888 		res += per_cpu_ptr(net->core.prot_inuse, cpu)->all;
3889 
3890 	return res;
3891 }
3892 
3893 EXPORT_SYMBOL_GPL(sock_inuse_get);
3894 
sock_inuse_init_net(struct net * net)3895 static int __net_init sock_inuse_init_net(struct net *net)
3896 {
3897 	net->core.prot_inuse = alloc_percpu(struct prot_inuse);
3898 	if (net->core.prot_inuse == NULL)
3899 		return -ENOMEM;
3900 	return 0;
3901 }
3902 
sock_inuse_exit_net(struct net * net)3903 static void __net_exit sock_inuse_exit_net(struct net *net)
3904 {
3905 	free_percpu(net->core.prot_inuse);
3906 }
3907 
3908 static struct pernet_operations net_inuse_ops = {
3909 	.init = sock_inuse_init_net,
3910 	.exit = sock_inuse_exit_net,
3911 };
3912 
net_inuse_init(void)3913 static __init int net_inuse_init(void)
3914 {
3915 	if (register_pernet_subsys(&net_inuse_ops))
3916 		panic("Cannot initialize net inuse counters");
3917 
3918 	return 0;
3919 }
3920 
3921 core_initcall(net_inuse_init);
3922 
assign_proto_idx(struct proto * prot)3923 static int assign_proto_idx(struct proto *prot)
3924 {
3925 	prot->inuse_idx = find_first_zero_bit(proto_inuse_idx, PROTO_INUSE_NR);
3926 
3927 	if (unlikely(prot->inuse_idx == PROTO_INUSE_NR - 1)) {
3928 		pr_err("PROTO_INUSE_NR exhausted\n");
3929 		return -ENOSPC;
3930 	}
3931 
3932 	set_bit(prot->inuse_idx, proto_inuse_idx);
3933 	return 0;
3934 }
3935 
release_proto_idx(struct proto * prot)3936 static void release_proto_idx(struct proto *prot)
3937 {
3938 	if (prot->inuse_idx != PROTO_INUSE_NR - 1)
3939 		clear_bit(prot->inuse_idx, proto_inuse_idx);
3940 }
3941 #else
assign_proto_idx(struct proto * prot)3942 static inline int assign_proto_idx(struct proto *prot)
3943 {
3944 	return 0;
3945 }
3946 
release_proto_idx(struct proto * prot)3947 static inline void release_proto_idx(struct proto *prot)
3948 {
3949 }
3950 
3951 #endif
3952 
tw_prot_cleanup(struct timewait_sock_ops * twsk_prot)3953 static void tw_prot_cleanup(struct timewait_sock_ops *twsk_prot)
3954 {
3955 	if (!twsk_prot)
3956 		return;
3957 	kfree(twsk_prot->twsk_slab_name);
3958 	twsk_prot->twsk_slab_name = NULL;
3959 	kmem_cache_destroy(twsk_prot->twsk_slab);
3960 	twsk_prot->twsk_slab = NULL;
3961 }
3962 
tw_prot_init(const struct proto * prot)3963 static int tw_prot_init(const struct proto *prot)
3964 {
3965 	struct timewait_sock_ops *twsk_prot = prot->twsk_prot;
3966 
3967 	if (!twsk_prot)
3968 		return 0;
3969 
3970 	twsk_prot->twsk_slab_name = kasprintf(GFP_KERNEL, "tw_sock_%s",
3971 					      prot->name);
3972 	if (!twsk_prot->twsk_slab_name)
3973 		return -ENOMEM;
3974 
3975 	twsk_prot->twsk_slab =
3976 		kmem_cache_create(twsk_prot->twsk_slab_name,
3977 				  twsk_prot->twsk_obj_size, 0,
3978 				  SLAB_ACCOUNT | prot->slab_flags,
3979 				  NULL);
3980 	if (!twsk_prot->twsk_slab) {
3981 		pr_crit("%s: Can't create timewait sock SLAB cache!\n",
3982 			prot->name);
3983 		return -ENOMEM;
3984 	}
3985 
3986 	return 0;
3987 }
3988 
req_prot_cleanup(struct request_sock_ops * rsk_prot)3989 static void req_prot_cleanup(struct request_sock_ops *rsk_prot)
3990 {
3991 	if (!rsk_prot)
3992 		return;
3993 	kfree(rsk_prot->slab_name);
3994 	rsk_prot->slab_name = NULL;
3995 	kmem_cache_destroy(rsk_prot->slab);
3996 	rsk_prot->slab = NULL;
3997 }
3998 
req_prot_init(const struct proto * prot)3999 static int req_prot_init(const struct proto *prot)
4000 {
4001 	struct request_sock_ops *rsk_prot = prot->rsk_prot;
4002 
4003 	if (!rsk_prot)
4004 		return 0;
4005 
4006 	rsk_prot->slab_name = kasprintf(GFP_KERNEL, "request_sock_%s",
4007 					prot->name);
4008 	if (!rsk_prot->slab_name)
4009 		return -ENOMEM;
4010 
4011 	rsk_prot->slab = kmem_cache_create(rsk_prot->slab_name,
4012 					   rsk_prot->obj_size, 0,
4013 					   SLAB_ACCOUNT | prot->slab_flags,
4014 					   NULL);
4015 
4016 	if (!rsk_prot->slab) {
4017 		pr_crit("%s: Can't create request sock SLAB cache!\n",
4018 			prot->name);
4019 		return -ENOMEM;
4020 	}
4021 	return 0;
4022 }
4023 
proto_register(struct proto * prot,int alloc_slab)4024 int proto_register(struct proto *prot, int alloc_slab)
4025 {
4026 	int ret = -ENOBUFS;
4027 
4028 	if (prot->memory_allocated && !prot->sysctl_mem) {
4029 		pr_err("%s: missing sysctl_mem\n", prot->name);
4030 		return -EINVAL;
4031 	}
4032 	if (prot->memory_allocated && !prot->per_cpu_fw_alloc) {
4033 		pr_err("%s: missing per_cpu_fw_alloc\n", prot->name);
4034 		return -EINVAL;
4035 	}
4036 	if (alloc_slab) {
4037 		prot->slab = kmem_cache_create_usercopy(prot->name,
4038 					prot->obj_size, 0,
4039 					SLAB_HWCACHE_ALIGN | SLAB_ACCOUNT |
4040 					prot->slab_flags,
4041 					prot->useroffset, prot->usersize,
4042 					NULL);
4043 
4044 		if (prot->slab == NULL) {
4045 			pr_crit("%s: Can't create sock SLAB cache!\n",
4046 				prot->name);
4047 			goto out;
4048 		}
4049 
4050 		if (req_prot_init(prot))
4051 			goto out_free_request_sock_slab;
4052 
4053 		if (tw_prot_init(prot))
4054 			goto out_free_timewait_sock_slab;
4055 	}
4056 
4057 	mutex_lock(&proto_list_mutex);
4058 	ret = assign_proto_idx(prot);
4059 	if (ret) {
4060 		mutex_unlock(&proto_list_mutex);
4061 		goto out_free_timewait_sock_slab;
4062 	}
4063 	list_add(&prot->node, &proto_list);
4064 	mutex_unlock(&proto_list_mutex);
4065 	return ret;
4066 
4067 out_free_timewait_sock_slab:
4068 	if (alloc_slab)
4069 		tw_prot_cleanup(prot->twsk_prot);
4070 out_free_request_sock_slab:
4071 	if (alloc_slab) {
4072 		req_prot_cleanup(prot->rsk_prot);
4073 
4074 		kmem_cache_destroy(prot->slab);
4075 		prot->slab = NULL;
4076 	}
4077 out:
4078 	return ret;
4079 }
4080 EXPORT_SYMBOL(proto_register);
4081 
proto_unregister(struct proto * prot)4082 void proto_unregister(struct proto *prot)
4083 {
4084 	mutex_lock(&proto_list_mutex);
4085 	release_proto_idx(prot);
4086 	list_del(&prot->node);
4087 	mutex_unlock(&proto_list_mutex);
4088 
4089 	kmem_cache_destroy(prot->slab);
4090 	prot->slab = NULL;
4091 
4092 	req_prot_cleanup(prot->rsk_prot);
4093 	tw_prot_cleanup(prot->twsk_prot);
4094 }
4095 EXPORT_SYMBOL(proto_unregister);
4096 
sock_load_diag_module(int family,int protocol)4097 int sock_load_diag_module(int family, int protocol)
4098 {
4099 	if (!protocol) {
4100 		if (!sock_is_registered(family))
4101 			return -ENOENT;
4102 
4103 		return request_module("net-pf-%d-proto-%d-type-%d", PF_NETLINK,
4104 				      NETLINK_SOCK_DIAG, family);
4105 	}
4106 
4107 #ifdef CONFIG_INET
4108 	if (family == AF_INET &&
4109 	    protocol != IPPROTO_RAW &&
4110 	    protocol < MAX_INET_PROTOS &&
4111 	    !rcu_access_pointer(inet_protos[protocol]))
4112 		return -ENOENT;
4113 #endif
4114 
4115 	return request_module("net-pf-%d-proto-%d-type-%d-%d", PF_NETLINK,
4116 			      NETLINK_SOCK_DIAG, family, protocol);
4117 }
4118 EXPORT_SYMBOL(sock_load_diag_module);
4119 
4120 #ifdef CONFIG_PROC_FS
proto_seq_start(struct seq_file * seq,loff_t * pos)4121 static void *proto_seq_start(struct seq_file *seq, loff_t *pos)
4122 	__acquires(proto_list_mutex)
4123 {
4124 	mutex_lock(&proto_list_mutex);
4125 	return seq_list_start_head(&proto_list, *pos);
4126 }
4127 
proto_seq_next(struct seq_file * seq,void * v,loff_t * pos)4128 static void *proto_seq_next(struct seq_file *seq, void *v, loff_t *pos)
4129 {
4130 	return seq_list_next(v, &proto_list, pos);
4131 }
4132 
proto_seq_stop(struct seq_file * seq,void * v)4133 static void proto_seq_stop(struct seq_file *seq, void *v)
4134 	__releases(proto_list_mutex)
4135 {
4136 	mutex_unlock(&proto_list_mutex);
4137 }
4138 
proto_method_implemented(const void * method)4139 static char proto_method_implemented(const void *method)
4140 {
4141 	return method == NULL ? 'n' : 'y';
4142 }
sock_prot_memory_allocated(struct proto * proto)4143 static long sock_prot_memory_allocated(struct proto *proto)
4144 {
4145 	return proto->memory_allocated != NULL ? proto_memory_allocated(proto) : -1L;
4146 }
4147 
sock_prot_memory_pressure(struct proto * proto)4148 static const char *sock_prot_memory_pressure(struct proto *proto)
4149 {
4150 	return proto->memory_pressure != NULL ?
4151 	proto_memory_pressure(proto) ? "yes" : "no" : "NI";
4152 }
4153 
proto_seq_printf(struct seq_file * seq,struct proto * proto)4154 static void proto_seq_printf(struct seq_file *seq, struct proto *proto)
4155 {
4156 
4157 	seq_printf(seq, "%-9s %4u %6d  %6ld   %-3s %6u   %-3s  %-10s "
4158 			"%2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c\n",
4159 		   proto->name,
4160 		   proto->obj_size,
4161 		   sock_prot_inuse_get(seq_file_net(seq), proto),
4162 		   sock_prot_memory_allocated(proto),
4163 		   sock_prot_memory_pressure(proto),
4164 		   proto->max_header,
4165 		   proto->slab == NULL ? "no" : "yes",
4166 		   module_name(proto->owner),
4167 		   proto_method_implemented(proto->close),
4168 		   proto_method_implemented(proto->connect),
4169 		   proto_method_implemented(proto->disconnect),
4170 		   proto_method_implemented(proto->accept),
4171 		   proto_method_implemented(proto->ioctl),
4172 		   proto_method_implemented(proto->init),
4173 		   proto_method_implemented(proto->destroy),
4174 		   proto_method_implemented(proto->shutdown),
4175 		   proto_method_implemented(proto->setsockopt),
4176 		   proto_method_implemented(proto->getsockopt),
4177 		   proto_method_implemented(proto->sendmsg),
4178 		   proto_method_implemented(proto->recvmsg),
4179 		   proto_method_implemented(proto->bind),
4180 		   proto_method_implemented(proto->backlog_rcv),
4181 		   proto_method_implemented(proto->hash),
4182 		   proto_method_implemented(proto->unhash),
4183 		   proto_method_implemented(proto->get_port),
4184 		   proto_method_implemented(proto->enter_memory_pressure));
4185 }
4186 
proto_seq_show(struct seq_file * seq,void * v)4187 static int proto_seq_show(struct seq_file *seq, void *v)
4188 {
4189 	if (v == &proto_list)
4190 		seq_printf(seq, "%-9s %-4s %-8s %-6s %-5s %-7s %-4s %-10s %s",
4191 			   "protocol",
4192 			   "size",
4193 			   "sockets",
4194 			   "memory",
4195 			   "press",
4196 			   "maxhdr",
4197 			   "slab",
4198 			   "module",
4199 			   "cl co di ac io in de sh ss gs se re bi br ha uh gp em\n");
4200 	else
4201 		proto_seq_printf(seq, list_entry(v, struct proto, node));
4202 	return 0;
4203 }
4204 
4205 static const struct seq_operations proto_seq_ops = {
4206 	.start  = proto_seq_start,
4207 	.next   = proto_seq_next,
4208 	.stop   = proto_seq_stop,
4209 	.show   = proto_seq_show,
4210 };
4211 
proto_init_net(struct net * net)4212 static __net_init int proto_init_net(struct net *net)
4213 {
4214 	if (!proc_create_net("protocols", 0444, net->proc_net, &proto_seq_ops,
4215 			sizeof(struct seq_net_private)))
4216 		return -ENOMEM;
4217 
4218 	return 0;
4219 }
4220 
proto_exit_net(struct net * net)4221 static __net_exit void proto_exit_net(struct net *net)
4222 {
4223 	remove_proc_entry("protocols", net->proc_net);
4224 }
4225 
4226 
4227 static __net_initdata struct pernet_operations proto_net_ops = {
4228 	.init = proto_init_net,
4229 	.exit = proto_exit_net,
4230 };
4231 
proto_init(void)4232 static int __init proto_init(void)
4233 {
4234 	return register_pernet_subsys(&proto_net_ops);
4235 }
4236 
4237 subsys_initcall(proto_init);
4238 
4239 #endif /* PROC_FS */
4240 
4241 #ifdef CONFIG_NET_RX_BUSY_POLL
sk_busy_loop_end(void * p,unsigned long start_time)4242 bool sk_busy_loop_end(void *p, unsigned long start_time)
4243 {
4244 	struct sock *sk = p;
4245 
4246 	if (!skb_queue_empty_lockless(&sk->sk_receive_queue))
4247 		return true;
4248 
4249 	if (sk_is_udp(sk) &&
4250 	    !skb_queue_empty_lockless(&udp_sk(sk)->reader_queue))
4251 		return true;
4252 
4253 	return sk_busy_loop_timeout(sk, start_time);
4254 }
4255 EXPORT_SYMBOL(sk_busy_loop_end);
4256 #endif /* CONFIG_NET_RX_BUSY_POLL */
4257 
sock_bind_add(struct sock * sk,struct sockaddr * addr,int addr_len)4258 int sock_bind_add(struct sock *sk, struct sockaddr *addr, int addr_len)
4259 {
4260 	if (!sk->sk_prot->bind_add)
4261 		return -EOPNOTSUPP;
4262 	return sk->sk_prot->bind_add(sk, addr, addr_len);
4263 }
4264 EXPORT_SYMBOL(sock_bind_add);
4265 
4266 /* Copy 'size' bytes from userspace and return `size` back to userspace */
sock_ioctl_inout(struct sock * sk,unsigned int cmd,void __user * arg,void * karg,size_t size)4267 int sock_ioctl_inout(struct sock *sk, unsigned int cmd,
4268 		     void __user *arg, void *karg, size_t size)
4269 {
4270 	int ret;
4271 
4272 	if (copy_from_user(karg, arg, size))
4273 		return -EFAULT;
4274 
4275 	ret = READ_ONCE(sk->sk_prot)->ioctl(sk, cmd, karg);
4276 	if (ret)
4277 		return ret;
4278 
4279 	if (copy_to_user(arg, karg, size))
4280 		return -EFAULT;
4281 
4282 	return 0;
4283 }
4284 EXPORT_SYMBOL(sock_ioctl_inout);
4285 
4286 /* This is the most common ioctl prep function, where the result (4 bytes) is
4287  * copied back to userspace if the ioctl() returns successfully. No input is
4288  * copied from userspace as input argument.
4289  */
sock_ioctl_out(struct sock * sk,unsigned int cmd,void __user * arg)4290 static int sock_ioctl_out(struct sock *sk, unsigned int cmd, void __user *arg)
4291 {
4292 	int ret, karg = 0;
4293 
4294 	ret = READ_ONCE(sk->sk_prot)->ioctl(sk, cmd, &karg);
4295 	if (ret)
4296 		return ret;
4297 
4298 	return put_user(karg, (int __user *)arg);
4299 }
4300 
4301 /* A wrapper around sock ioctls, which copies the data from userspace
4302  * (depending on the protocol/ioctl), and copies back the result to userspace.
4303  * The main motivation for this function is to pass kernel memory to the
4304  * protocol ioctl callbacks, instead of userspace memory.
4305  */
sk_ioctl(struct sock * sk,unsigned int cmd,void __user * arg)4306 int sk_ioctl(struct sock *sk, unsigned int cmd, void __user *arg)
4307 {
4308 	int rc = 1;
4309 
4310 	if (sk->sk_type == SOCK_RAW && sk->sk_family == AF_INET)
4311 		rc = ipmr_sk_ioctl(sk, cmd, arg);
4312 	else if (sk->sk_type == SOCK_RAW && sk->sk_family == AF_INET6)
4313 		rc = ip6mr_sk_ioctl(sk, cmd, arg);
4314 	else if (sk_is_phonet(sk))
4315 		rc = phonet_sk_ioctl(sk, cmd, arg);
4316 
4317 	/* If ioctl was processed, returns its value */
4318 	if (rc <= 0)
4319 		return rc;
4320 
4321 	/* Otherwise call the default handler */
4322 	return sock_ioctl_out(sk, cmd, arg);
4323 }
4324 EXPORT_SYMBOL(sk_ioctl);
4325 
sock_struct_check(void)4326 static int __init sock_struct_check(void)
4327 {
4328 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_rx, sk_drops);
4329 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_rx, sk_peek_off);
4330 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_rx, sk_error_queue);
4331 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_rx, sk_receive_queue);
4332 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_rx, sk_backlog);
4333 
4334 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_rx, sk_rx_dst);
4335 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_rx, sk_rx_dst_ifindex);
4336 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_rx, sk_rx_dst_cookie);
4337 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_rx, sk_rcvbuf);
4338 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_rx, sk_filter);
4339 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_rx, sk_wq);
4340 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_rx, sk_data_ready);
4341 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_rx, sk_rcvtimeo);
4342 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_rx, sk_rcvlowat);
4343 
4344 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_rxtx, sk_err);
4345 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_rxtx, sk_socket);
4346 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_rxtx, sk_memcg);
4347 
4348 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_rxtx, sk_lock);
4349 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_rxtx, sk_reserved_mem);
4350 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_rxtx, sk_forward_alloc);
4351 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_rxtx, sk_tsflags);
4352 
4353 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_omem_alloc);
4354 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_omem_alloc);
4355 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_sndbuf);
4356 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_wmem_queued);
4357 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_wmem_alloc);
4358 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_tsq_flags);
4359 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_send_head);
4360 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_write_queue);
4361 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_write_pending);
4362 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_dst_pending_confirm);
4363 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_pacing_status);
4364 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_frag);
4365 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_timer);
4366 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_pacing_rate);
4367 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_zckey);
4368 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_tskey);
4369 
4370 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_max_pacing_rate);
4371 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_sndtimeo);
4372 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_priority);
4373 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_mark);
4374 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_dst_cache);
4375 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_route_caps);
4376 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_gso_type);
4377 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_gso_max_size);
4378 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_allocation);
4379 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_txhash);
4380 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_gso_max_segs);
4381 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_pacing_shift);
4382 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_use_task_frag);
4383 	return 0;
4384 }
4385 
4386 core_initcall(sock_struct_check);
4387