xref: /linux/net/core/sock.c (revision 1a9239bb4253f9076b5b4b2a1a4e8d7defd77a95)
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 
sk_set_prio_allowed(const struct sock * sk,int val)457 static bool sk_set_prio_allowed(const struct sock *sk, int val)
458 {
459 	return ((val >= TC_PRIO_BESTEFFORT && val <= TC_PRIO_INTERACTIVE) ||
460 		sockopt_ns_capable(sock_net(sk)->user_ns, CAP_NET_RAW) ||
461 		sockopt_ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN));
462 }
463 
sock_needs_netstamp(const struct sock * sk)464 static bool sock_needs_netstamp(const struct sock *sk)
465 {
466 	switch (sk->sk_family) {
467 	case AF_UNSPEC:
468 	case AF_UNIX:
469 		return false;
470 	default:
471 		return true;
472 	}
473 }
474 
sock_disable_timestamp(struct sock * sk,unsigned long flags)475 static void sock_disable_timestamp(struct sock *sk, unsigned long flags)
476 {
477 	if (sk->sk_flags & flags) {
478 		sk->sk_flags &= ~flags;
479 		if (sock_needs_netstamp(sk) &&
480 		    !(sk->sk_flags & SK_FLAGS_TIMESTAMP))
481 			net_disable_timestamp();
482 	}
483 }
484 
485 
__sock_queue_rcv_skb(struct sock * sk,struct sk_buff * skb)486 int __sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
487 {
488 	unsigned long flags;
489 	struct sk_buff_head *list = &sk->sk_receive_queue;
490 
491 	if (atomic_read(&sk->sk_rmem_alloc) >= READ_ONCE(sk->sk_rcvbuf)) {
492 		atomic_inc(&sk->sk_drops);
493 		trace_sock_rcvqueue_full(sk, skb);
494 		return -ENOMEM;
495 	}
496 
497 	if (!sk_rmem_schedule(sk, skb, skb->truesize)) {
498 		atomic_inc(&sk->sk_drops);
499 		return -ENOBUFS;
500 	}
501 
502 	skb->dev = NULL;
503 	skb_set_owner_r(skb, sk);
504 
505 	/* we escape from rcu protected region, make sure we dont leak
506 	 * a norefcounted dst
507 	 */
508 	skb_dst_force(skb);
509 
510 	spin_lock_irqsave(&list->lock, flags);
511 	sock_skb_set_dropcount(sk, skb);
512 	__skb_queue_tail(list, skb);
513 	spin_unlock_irqrestore(&list->lock, flags);
514 
515 	if (!sock_flag(sk, SOCK_DEAD))
516 		sk->sk_data_ready(sk);
517 	return 0;
518 }
519 EXPORT_SYMBOL(__sock_queue_rcv_skb);
520 
sock_queue_rcv_skb_reason(struct sock * sk,struct sk_buff * skb,enum skb_drop_reason * reason)521 int sock_queue_rcv_skb_reason(struct sock *sk, struct sk_buff *skb,
522 			      enum skb_drop_reason *reason)
523 {
524 	enum skb_drop_reason drop_reason;
525 	int err;
526 
527 	err = sk_filter(sk, skb);
528 	if (err) {
529 		drop_reason = SKB_DROP_REASON_SOCKET_FILTER;
530 		goto out;
531 	}
532 	err = __sock_queue_rcv_skb(sk, skb);
533 	switch (err) {
534 	case -ENOMEM:
535 		drop_reason = SKB_DROP_REASON_SOCKET_RCVBUFF;
536 		break;
537 	case -ENOBUFS:
538 		drop_reason = SKB_DROP_REASON_PROTO_MEM;
539 		break;
540 	default:
541 		drop_reason = SKB_NOT_DROPPED_YET;
542 		break;
543 	}
544 out:
545 	if (reason)
546 		*reason = drop_reason;
547 	return err;
548 }
549 EXPORT_SYMBOL(sock_queue_rcv_skb_reason);
550 
__sk_receive_skb(struct sock * sk,struct sk_buff * skb,const int nested,unsigned int trim_cap,bool refcounted)551 int __sk_receive_skb(struct sock *sk, struct sk_buff *skb,
552 		     const int nested, unsigned int trim_cap, bool refcounted)
553 {
554 	int rc = NET_RX_SUCCESS;
555 
556 	if (sk_filter_trim_cap(sk, skb, trim_cap))
557 		goto discard_and_relse;
558 
559 	skb->dev = NULL;
560 
561 	if (sk_rcvqueues_full(sk, READ_ONCE(sk->sk_rcvbuf))) {
562 		atomic_inc(&sk->sk_drops);
563 		goto discard_and_relse;
564 	}
565 	if (nested)
566 		bh_lock_sock_nested(sk);
567 	else
568 		bh_lock_sock(sk);
569 	if (!sock_owned_by_user(sk)) {
570 		/*
571 		 * trylock + unlock semantics:
572 		 */
573 		mutex_acquire(&sk->sk_lock.dep_map, 0, 1, _RET_IP_);
574 
575 		rc = sk_backlog_rcv(sk, skb);
576 
577 		mutex_release(&sk->sk_lock.dep_map, _RET_IP_);
578 	} else if (sk_add_backlog(sk, skb, READ_ONCE(sk->sk_rcvbuf))) {
579 		bh_unlock_sock(sk);
580 		atomic_inc(&sk->sk_drops);
581 		goto discard_and_relse;
582 	}
583 
584 	bh_unlock_sock(sk);
585 out:
586 	if (refcounted)
587 		sock_put(sk);
588 	return rc;
589 discard_and_relse:
590 	kfree_skb(skb);
591 	goto out;
592 }
593 EXPORT_SYMBOL(__sk_receive_skb);
594 
595 INDIRECT_CALLABLE_DECLARE(struct dst_entry *ip6_dst_check(struct dst_entry *,
596 							  u32));
597 INDIRECT_CALLABLE_DECLARE(struct dst_entry *ipv4_dst_check(struct dst_entry *,
598 							   u32));
__sk_dst_check(struct sock * sk,u32 cookie)599 struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie)
600 {
601 	struct dst_entry *dst = __sk_dst_get(sk);
602 
603 	if (dst && dst->obsolete &&
604 	    INDIRECT_CALL_INET(dst->ops->check, ip6_dst_check, ipv4_dst_check,
605 			       dst, cookie) == NULL) {
606 		sk_tx_queue_clear(sk);
607 		WRITE_ONCE(sk->sk_dst_pending_confirm, 0);
608 		RCU_INIT_POINTER(sk->sk_dst_cache, NULL);
609 		dst_release(dst);
610 		return NULL;
611 	}
612 
613 	return dst;
614 }
615 EXPORT_SYMBOL(__sk_dst_check);
616 
sk_dst_check(struct sock * sk,u32 cookie)617 struct dst_entry *sk_dst_check(struct sock *sk, u32 cookie)
618 {
619 	struct dst_entry *dst = sk_dst_get(sk);
620 
621 	if (dst && dst->obsolete &&
622 	    INDIRECT_CALL_INET(dst->ops->check, ip6_dst_check, ipv4_dst_check,
623 			       dst, cookie) == NULL) {
624 		sk_dst_reset(sk);
625 		dst_release(dst);
626 		return NULL;
627 	}
628 
629 	return dst;
630 }
631 EXPORT_SYMBOL(sk_dst_check);
632 
sock_bindtoindex_locked(struct sock * sk,int ifindex)633 static int sock_bindtoindex_locked(struct sock *sk, int ifindex)
634 {
635 	int ret = -ENOPROTOOPT;
636 #ifdef CONFIG_NETDEVICES
637 	struct net *net = sock_net(sk);
638 
639 	/* Sorry... */
640 	ret = -EPERM;
641 	if (sk->sk_bound_dev_if && !ns_capable(net->user_ns, CAP_NET_RAW))
642 		goto out;
643 
644 	ret = -EINVAL;
645 	if (ifindex < 0)
646 		goto out;
647 
648 	/* Paired with all READ_ONCE() done locklessly. */
649 	WRITE_ONCE(sk->sk_bound_dev_if, ifindex);
650 
651 	if (sk->sk_prot->rehash)
652 		sk->sk_prot->rehash(sk);
653 	sk_dst_reset(sk);
654 
655 	ret = 0;
656 
657 out:
658 #endif
659 
660 	return ret;
661 }
662 
sock_bindtoindex(struct sock * sk,int ifindex,bool lock_sk)663 int sock_bindtoindex(struct sock *sk, int ifindex, bool lock_sk)
664 {
665 	int ret;
666 
667 	if (lock_sk)
668 		lock_sock(sk);
669 	ret = sock_bindtoindex_locked(sk, ifindex);
670 	if (lock_sk)
671 		release_sock(sk);
672 
673 	return ret;
674 }
675 EXPORT_SYMBOL(sock_bindtoindex);
676 
sock_setbindtodevice(struct sock * sk,sockptr_t optval,int optlen)677 static int sock_setbindtodevice(struct sock *sk, sockptr_t optval, int optlen)
678 {
679 	int ret = -ENOPROTOOPT;
680 #ifdef CONFIG_NETDEVICES
681 	struct net *net = sock_net(sk);
682 	char devname[IFNAMSIZ];
683 	int index;
684 
685 	ret = -EINVAL;
686 	if (optlen < 0)
687 		goto out;
688 
689 	/* Bind this socket to a particular device like "eth0",
690 	 * as specified in the passed interface name. If the
691 	 * name is "" or the option length is zero the socket
692 	 * is not bound.
693 	 */
694 	if (optlen > IFNAMSIZ - 1)
695 		optlen = IFNAMSIZ - 1;
696 	memset(devname, 0, sizeof(devname));
697 
698 	ret = -EFAULT;
699 	if (copy_from_sockptr(devname, optval, optlen))
700 		goto out;
701 
702 	index = 0;
703 	if (devname[0] != '\0') {
704 		struct net_device *dev;
705 
706 		rcu_read_lock();
707 		dev = dev_get_by_name_rcu(net, devname);
708 		if (dev)
709 			index = dev->ifindex;
710 		rcu_read_unlock();
711 		ret = -ENODEV;
712 		if (!dev)
713 			goto out;
714 	}
715 
716 	sockopt_lock_sock(sk);
717 	ret = sock_bindtoindex_locked(sk, index);
718 	sockopt_release_sock(sk);
719 out:
720 #endif
721 
722 	return ret;
723 }
724 
sock_getbindtodevice(struct sock * sk,sockptr_t optval,sockptr_t optlen,int len)725 static int sock_getbindtodevice(struct sock *sk, sockptr_t optval,
726 				sockptr_t optlen, int len)
727 {
728 	int ret = -ENOPROTOOPT;
729 #ifdef CONFIG_NETDEVICES
730 	int bound_dev_if = READ_ONCE(sk->sk_bound_dev_if);
731 	struct net *net = sock_net(sk);
732 	char devname[IFNAMSIZ];
733 
734 	if (bound_dev_if == 0) {
735 		len = 0;
736 		goto zero;
737 	}
738 
739 	ret = -EINVAL;
740 	if (len < IFNAMSIZ)
741 		goto out;
742 
743 	ret = netdev_get_name(net, devname, bound_dev_if);
744 	if (ret)
745 		goto out;
746 
747 	len = strlen(devname) + 1;
748 
749 	ret = -EFAULT;
750 	if (copy_to_sockptr(optval, devname, len))
751 		goto out;
752 
753 zero:
754 	ret = -EFAULT;
755 	if (copy_to_sockptr(optlen, &len, sizeof(int)))
756 		goto out;
757 
758 	ret = 0;
759 
760 out:
761 #endif
762 
763 	return ret;
764 }
765 
sk_mc_loop(const struct sock * sk)766 bool sk_mc_loop(const struct sock *sk)
767 {
768 	if (dev_recursion_level())
769 		return false;
770 	if (!sk)
771 		return true;
772 	/* IPV6_ADDRFORM can change sk->sk_family under us. */
773 	switch (READ_ONCE(sk->sk_family)) {
774 	case AF_INET:
775 		return inet_test_bit(MC_LOOP, sk);
776 #if IS_ENABLED(CONFIG_IPV6)
777 	case AF_INET6:
778 		return inet6_test_bit(MC6_LOOP, sk);
779 #endif
780 	}
781 	WARN_ON_ONCE(1);
782 	return true;
783 }
784 EXPORT_SYMBOL(sk_mc_loop);
785 
sock_set_reuseaddr(struct sock * sk)786 void sock_set_reuseaddr(struct sock *sk)
787 {
788 	lock_sock(sk);
789 	sk->sk_reuse = SK_CAN_REUSE;
790 	release_sock(sk);
791 }
792 EXPORT_SYMBOL(sock_set_reuseaddr);
793 
sock_set_reuseport(struct sock * sk)794 void sock_set_reuseport(struct sock *sk)
795 {
796 	lock_sock(sk);
797 	sk->sk_reuseport = true;
798 	release_sock(sk);
799 }
800 EXPORT_SYMBOL(sock_set_reuseport);
801 
sock_no_linger(struct sock * sk)802 void sock_no_linger(struct sock *sk)
803 {
804 	lock_sock(sk);
805 	WRITE_ONCE(sk->sk_lingertime, 0);
806 	sock_set_flag(sk, SOCK_LINGER);
807 	release_sock(sk);
808 }
809 EXPORT_SYMBOL(sock_no_linger);
810 
sock_set_priority(struct sock * sk,u32 priority)811 void sock_set_priority(struct sock *sk, u32 priority)
812 {
813 	WRITE_ONCE(sk->sk_priority, priority);
814 }
815 EXPORT_SYMBOL(sock_set_priority);
816 
sock_set_sndtimeo(struct sock * sk,s64 secs)817 void sock_set_sndtimeo(struct sock *sk, s64 secs)
818 {
819 	lock_sock(sk);
820 	if (secs && secs < MAX_SCHEDULE_TIMEOUT / HZ - 1)
821 		WRITE_ONCE(sk->sk_sndtimeo, secs * HZ);
822 	else
823 		WRITE_ONCE(sk->sk_sndtimeo, MAX_SCHEDULE_TIMEOUT);
824 	release_sock(sk);
825 }
826 EXPORT_SYMBOL(sock_set_sndtimeo);
827 
__sock_set_timestamps(struct sock * sk,bool val,bool new,bool ns)828 static void __sock_set_timestamps(struct sock *sk, bool val, bool new, bool ns)
829 {
830 	sock_valbool_flag(sk, SOCK_RCVTSTAMP, val);
831 	sock_valbool_flag(sk, SOCK_RCVTSTAMPNS, val && ns);
832 	if (val)  {
833 		sock_valbool_flag(sk, SOCK_TSTAMP_NEW, new);
834 		sock_enable_timestamp(sk, SOCK_TIMESTAMP);
835 	}
836 }
837 
sock_enable_timestamps(struct sock * sk)838 void sock_enable_timestamps(struct sock *sk)
839 {
840 	lock_sock(sk);
841 	__sock_set_timestamps(sk, true, false, true);
842 	release_sock(sk);
843 }
844 EXPORT_SYMBOL(sock_enable_timestamps);
845 
sock_set_timestamp(struct sock * sk,int optname,bool valbool)846 void sock_set_timestamp(struct sock *sk, int optname, bool valbool)
847 {
848 	switch (optname) {
849 	case SO_TIMESTAMP_OLD:
850 		__sock_set_timestamps(sk, valbool, false, false);
851 		break;
852 	case SO_TIMESTAMP_NEW:
853 		__sock_set_timestamps(sk, valbool, true, false);
854 		break;
855 	case SO_TIMESTAMPNS_OLD:
856 		__sock_set_timestamps(sk, valbool, false, true);
857 		break;
858 	case SO_TIMESTAMPNS_NEW:
859 		__sock_set_timestamps(sk, valbool, true, true);
860 		break;
861 	}
862 }
863 
sock_timestamping_bind_phc(struct sock * sk,int phc_index)864 static int sock_timestamping_bind_phc(struct sock *sk, int phc_index)
865 {
866 	struct net *net = sock_net(sk);
867 	struct net_device *dev = NULL;
868 	bool match = false;
869 	int *vclock_index;
870 	int i, num;
871 
872 	if (sk->sk_bound_dev_if)
873 		dev = dev_get_by_index(net, sk->sk_bound_dev_if);
874 
875 	if (!dev) {
876 		pr_err("%s: sock not bind to device\n", __func__);
877 		return -EOPNOTSUPP;
878 	}
879 
880 	num = ethtool_get_phc_vclocks(dev, &vclock_index);
881 	dev_put(dev);
882 
883 	for (i = 0; i < num; i++) {
884 		if (*(vclock_index + i) == phc_index) {
885 			match = true;
886 			break;
887 		}
888 	}
889 
890 	if (num > 0)
891 		kfree(vclock_index);
892 
893 	if (!match)
894 		return -EINVAL;
895 
896 	WRITE_ONCE(sk->sk_bind_phc, phc_index);
897 
898 	return 0;
899 }
900 
sock_set_timestamping(struct sock * sk,int optname,struct so_timestamping timestamping)901 int sock_set_timestamping(struct sock *sk, int optname,
902 			  struct so_timestamping timestamping)
903 {
904 	int val = timestamping.flags;
905 	int ret;
906 
907 	if (val & ~SOF_TIMESTAMPING_MASK)
908 		return -EINVAL;
909 
910 	if (val & SOF_TIMESTAMPING_OPT_ID_TCP &&
911 	    !(val & SOF_TIMESTAMPING_OPT_ID))
912 		return -EINVAL;
913 
914 	if (val & SOF_TIMESTAMPING_OPT_ID &&
915 	    !(sk->sk_tsflags & SOF_TIMESTAMPING_OPT_ID)) {
916 		if (sk_is_tcp(sk)) {
917 			if ((1 << sk->sk_state) &
918 			    (TCPF_CLOSE | TCPF_LISTEN))
919 				return -EINVAL;
920 			if (val & SOF_TIMESTAMPING_OPT_ID_TCP)
921 				atomic_set(&sk->sk_tskey, tcp_sk(sk)->write_seq);
922 			else
923 				atomic_set(&sk->sk_tskey, tcp_sk(sk)->snd_una);
924 		} else {
925 			atomic_set(&sk->sk_tskey, 0);
926 		}
927 	}
928 
929 	if (val & SOF_TIMESTAMPING_OPT_STATS &&
930 	    !(val & SOF_TIMESTAMPING_OPT_TSONLY))
931 		return -EINVAL;
932 
933 	if (val & SOF_TIMESTAMPING_BIND_PHC) {
934 		ret = sock_timestamping_bind_phc(sk, timestamping.bind_phc);
935 		if (ret)
936 			return ret;
937 	}
938 
939 	WRITE_ONCE(sk->sk_tsflags, val);
940 	sock_valbool_flag(sk, SOCK_TSTAMP_NEW, optname == SO_TIMESTAMPING_NEW);
941 	sock_valbool_flag(sk, SOCK_TIMESTAMPING_ANY, !!(val & TSFLAGS_ANY));
942 
943 	if (val & SOF_TIMESTAMPING_RX_SOFTWARE)
944 		sock_enable_timestamp(sk,
945 				      SOCK_TIMESTAMPING_RX_SOFTWARE);
946 	else
947 		sock_disable_timestamp(sk,
948 				       (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE));
949 	return 0;
950 }
951 
952 #if defined(CONFIG_CGROUP_BPF)
bpf_skops_tx_timestamping(struct sock * sk,struct sk_buff * skb,int op)953 void bpf_skops_tx_timestamping(struct sock *sk, struct sk_buff *skb, int op)
954 {
955 	struct bpf_sock_ops_kern sock_ops;
956 
957 	memset(&sock_ops, 0, offsetof(struct bpf_sock_ops_kern, temp));
958 	sock_ops.op = op;
959 	sock_ops.is_fullsock = 1;
960 	sock_ops.sk = sk;
961 	bpf_skops_init_skb(&sock_ops, skb, 0);
962 	__cgroup_bpf_run_filter_sock_ops(sk, &sock_ops, CGROUP_SOCK_OPS);
963 }
964 #endif
965 
sock_set_keepalive(struct sock * sk)966 void sock_set_keepalive(struct sock *sk)
967 {
968 	lock_sock(sk);
969 	if (sk->sk_prot->keepalive)
970 		sk->sk_prot->keepalive(sk, true);
971 	sock_valbool_flag(sk, SOCK_KEEPOPEN, true);
972 	release_sock(sk);
973 }
974 EXPORT_SYMBOL(sock_set_keepalive);
975 
__sock_set_rcvbuf(struct sock * sk,int val)976 static void __sock_set_rcvbuf(struct sock *sk, int val)
977 {
978 	/* Ensure val * 2 fits into an int, to prevent max_t() from treating it
979 	 * as a negative value.
980 	 */
981 	val = min_t(int, val, INT_MAX / 2);
982 	sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
983 
984 	/* We double it on the way in to account for "struct sk_buff" etc.
985 	 * overhead.   Applications assume that the SO_RCVBUF setting they make
986 	 * will allow that much actual data to be received on that socket.
987 	 *
988 	 * Applications are unaware that "struct sk_buff" and other overheads
989 	 * allocate from the receive buffer during socket buffer allocation.
990 	 *
991 	 * And after considering the possible alternatives, returning the value
992 	 * we actually used in getsockopt is the most desirable behavior.
993 	 */
994 	WRITE_ONCE(sk->sk_rcvbuf, max_t(int, val * 2, SOCK_MIN_RCVBUF));
995 }
996 
sock_set_rcvbuf(struct sock * sk,int val)997 void sock_set_rcvbuf(struct sock *sk, int val)
998 {
999 	lock_sock(sk);
1000 	__sock_set_rcvbuf(sk, val);
1001 	release_sock(sk);
1002 }
1003 EXPORT_SYMBOL(sock_set_rcvbuf);
1004 
__sock_set_mark(struct sock * sk,u32 val)1005 static void __sock_set_mark(struct sock *sk, u32 val)
1006 {
1007 	if (val != sk->sk_mark) {
1008 		WRITE_ONCE(sk->sk_mark, val);
1009 		sk_dst_reset(sk);
1010 	}
1011 }
1012 
sock_set_mark(struct sock * sk,u32 val)1013 void sock_set_mark(struct sock *sk, u32 val)
1014 {
1015 	lock_sock(sk);
1016 	__sock_set_mark(sk, val);
1017 	release_sock(sk);
1018 }
1019 EXPORT_SYMBOL(sock_set_mark);
1020 
sock_release_reserved_memory(struct sock * sk,int bytes)1021 static void sock_release_reserved_memory(struct sock *sk, int bytes)
1022 {
1023 	/* Round down bytes to multiple of pages */
1024 	bytes = round_down(bytes, PAGE_SIZE);
1025 
1026 	WARN_ON(bytes > sk->sk_reserved_mem);
1027 	WRITE_ONCE(sk->sk_reserved_mem, sk->sk_reserved_mem - bytes);
1028 	sk_mem_reclaim(sk);
1029 }
1030 
sock_reserve_memory(struct sock * sk,int bytes)1031 static int sock_reserve_memory(struct sock *sk, int bytes)
1032 {
1033 	long allocated;
1034 	bool charged;
1035 	int pages;
1036 
1037 	if (!mem_cgroup_sockets_enabled || !sk->sk_memcg || !sk_has_account(sk))
1038 		return -EOPNOTSUPP;
1039 
1040 	if (!bytes)
1041 		return 0;
1042 
1043 	pages = sk_mem_pages(bytes);
1044 
1045 	/* pre-charge to memcg */
1046 	charged = mem_cgroup_charge_skmem(sk->sk_memcg, pages,
1047 					  GFP_KERNEL | __GFP_RETRY_MAYFAIL);
1048 	if (!charged)
1049 		return -ENOMEM;
1050 
1051 	/* pre-charge to forward_alloc */
1052 	sk_memory_allocated_add(sk, pages);
1053 	allocated = sk_memory_allocated(sk);
1054 	/* If the system goes into memory pressure with this
1055 	 * precharge, give up and return error.
1056 	 */
1057 	if (allocated > sk_prot_mem_limits(sk, 1)) {
1058 		sk_memory_allocated_sub(sk, pages);
1059 		mem_cgroup_uncharge_skmem(sk->sk_memcg, pages);
1060 		return -ENOMEM;
1061 	}
1062 	sk_forward_alloc_add(sk, pages << PAGE_SHIFT);
1063 
1064 	WRITE_ONCE(sk->sk_reserved_mem,
1065 		   sk->sk_reserved_mem + (pages << PAGE_SHIFT));
1066 
1067 	return 0;
1068 }
1069 
1070 #ifdef CONFIG_PAGE_POOL
1071 
1072 /* This is the number of tokens and frags that the user can SO_DEVMEM_DONTNEED
1073  * in 1 syscall. The limit exists to limit the amount of memory the kernel
1074  * allocates to copy these tokens, and to prevent looping over the frags for
1075  * too long.
1076  */
1077 #define MAX_DONTNEED_TOKENS 128
1078 #define MAX_DONTNEED_FRAGS 1024
1079 
1080 static noinline_for_stack int
sock_devmem_dontneed(struct sock * sk,sockptr_t optval,unsigned int optlen)1081 sock_devmem_dontneed(struct sock *sk, sockptr_t optval, unsigned int optlen)
1082 {
1083 	unsigned int num_tokens, i, j, k, netmem_num = 0;
1084 	struct dmabuf_token *tokens;
1085 	int ret = 0, num_frags = 0;
1086 	netmem_ref netmems[16];
1087 
1088 	if (!sk_is_tcp(sk))
1089 		return -EBADF;
1090 
1091 	if (optlen % sizeof(*tokens) ||
1092 	    optlen > sizeof(*tokens) * MAX_DONTNEED_TOKENS)
1093 		return -EINVAL;
1094 
1095 	num_tokens = optlen / sizeof(*tokens);
1096 	tokens = kvmalloc_array(num_tokens, sizeof(*tokens), GFP_KERNEL);
1097 	if (!tokens)
1098 		return -ENOMEM;
1099 
1100 	if (copy_from_sockptr(tokens, optval, optlen)) {
1101 		kvfree(tokens);
1102 		return -EFAULT;
1103 	}
1104 
1105 	xa_lock_bh(&sk->sk_user_frags);
1106 	for (i = 0; i < num_tokens; i++) {
1107 		for (j = 0; j < tokens[i].token_count; j++) {
1108 			if (++num_frags > MAX_DONTNEED_FRAGS)
1109 				goto frag_limit_reached;
1110 
1111 			netmem_ref netmem = (__force netmem_ref)__xa_erase(
1112 				&sk->sk_user_frags, tokens[i].token_start + j);
1113 
1114 			if (!netmem || WARN_ON_ONCE(!netmem_is_net_iov(netmem)))
1115 				continue;
1116 
1117 			netmems[netmem_num++] = netmem;
1118 			if (netmem_num == ARRAY_SIZE(netmems)) {
1119 				xa_unlock_bh(&sk->sk_user_frags);
1120 				for (k = 0; k < netmem_num; k++)
1121 					WARN_ON_ONCE(!napi_pp_put_page(netmems[k]));
1122 				netmem_num = 0;
1123 				xa_lock_bh(&sk->sk_user_frags);
1124 			}
1125 			ret++;
1126 		}
1127 	}
1128 
1129 frag_limit_reached:
1130 	xa_unlock_bh(&sk->sk_user_frags);
1131 	for (k = 0; k < netmem_num; k++)
1132 		WARN_ON_ONCE(!napi_pp_put_page(netmems[k]));
1133 
1134 	kvfree(tokens);
1135 	return ret;
1136 }
1137 #endif
1138 
sockopt_lock_sock(struct sock * sk)1139 void sockopt_lock_sock(struct sock *sk)
1140 {
1141 	/* When current->bpf_ctx is set, the setsockopt is called from
1142 	 * a bpf prog.  bpf has ensured the sk lock has been
1143 	 * acquired before calling setsockopt().
1144 	 */
1145 	if (has_current_bpf_ctx())
1146 		return;
1147 
1148 	lock_sock(sk);
1149 }
1150 EXPORT_SYMBOL(sockopt_lock_sock);
1151 
sockopt_release_sock(struct sock * sk)1152 void sockopt_release_sock(struct sock *sk)
1153 {
1154 	if (has_current_bpf_ctx())
1155 		return;
1156 
1157 	release_sock(sk);
1158 }
1159 EXPORT_SYMBOL(sockopt_release_sock);
1160 
sockopt_ns_capable(struct user_namespace * ns,int cap)1161 bool sockopt_ns_capable(struct user_namespace *ns, int cap)
1162 {
1163 	return has_current_bpf_ctx() || ns_capable(ns, cap);
1164 }
1165 EXPORT_SYMBOL(sockopt_ns_capable);
1166 
sockopt_capable(int cap)1167 bool sockopt_capable(int cap)
1168 {
1169 	return has_current_bpf_ctx() || capable(cap);
1170 }
1171 EXPORT_SYMBOL(sockopt_capable);
1172 
sockopt_validate_clockid(__kernel_clockid_t value)1173 static int sockopt_validate_clockid(__kernel_clockid_t value)
1174 {
1175 	switch (value) {
1176 	case CLOCK_REALTIME:
1177 	case CLOCK_MONOTONIC:
1178 	case CLOCK_TAI:
1179 		return 0;
1180 	}
1181 	return -EINVAL;
1182 }
1183 
1184 /*
1185  *	This is meant for all protocols to use and covers goings on
1186  *	at the socket level. Everything here is generic.
1187  */
1188 
sk_setsockopt(struct sock * sk,int level,int optname,sockptr_t optval,unsigned int optlen)1189 int sk_setsockopt(struct sock *sk, int level, int optname,
1190 		  sockptr_t optval, unsigned int optlen)
1191 {
1192 	struct so_timestamping timestamping;
1193 	struct socket *sock = sk->sk_socket;
1194 	struct sock_txtime sk_txtime;
1195 	int val;
1196 	int valbool;
1197 	struct linger ling;
1198 	int ret = 0;
1199 
1200 	/*
1201 	 *	Options without arguments
1202 	 */
1203 
1204 	if (optname == SO_BINDTODEVICE)
1205 		return sock_setbindtodevice(sk, optval, optlen);
1206 
1207 	if (optlen < sizeof(int))
1208 		return -EINVAL;
1209 
1210 	if (copy_from_sockptr(&val, optval, sizeof(val)))
1211 		return -EFAULT;
1212 
1213 	valbool = val ? 1 : 0;
1214 
1215 	/* handle options which do not require locking the socket. */
1216 	switch (optname) {
1217 	case SO_PRIORITY:
1218 		if (sk_set_prio_allowed(sk, val)) {
1219 			sock_set_priority(sk, val);
1220 			return 0;
1221 		}
1222 		return -EPERM;
1223 	case SO_PASSSEC:
1224 		assign_bit(SOCK_PASSSEC, &sock->flags, valbool);
1225 		return 0;
1226 	case SO_PASSCRED:
1227 		assign_bit(SOCK_PASSCRED, &sock->flags, valbool);
1228 		return 0;
1229 	case SO_PASSPIDFD:
1230 		assign_bit(SOCK_PASSPIDFD, &sock->flags, valbool);
1231 		return 0;
1232 	case SO_TYPE:
1233 	case SO_PROTOCOL:
1234 	case SO_DOMAIN:
1235 	case SO_ERROR:
1236 		return -ENOPROTOOPT;
1237 #ifdef CONFIG_NET_RX_BUSY_POLL
1238 	case SO_BUSY_POLL:
1239 		if (val < 0)
1240 			return -EINVAL;
1241 		WRITE_ONCE(sk->sk_ll_usec, val);
1242 		return 0;
1243 	case SO_PREFER_BUSY_POLL:
1244 		if (valbool && !sockopt_capable(CAP_NET_ADMIN))
1245 			return -EPERM;
1246 		WRITE_ONCE(sk->sk_prefer_busy_poll, valbool);
1247 		return 0;
1248 	case SO_BUSY_POLL_BUDGET:
1249 		if (val > READ_ONCE(sk->sk_busy_poll_budget) &&
1250 		    !sockopt_capable(CAP_NET_ADMIN))
1251 			return -EPERM;
1252 		if (val < 0 || val > U16_MAX)
1253 			return -EINVAL;
1254 		WRITE_ONCE(sk->sk_busy_poll_budget, val);
1255 		return 0;
1256 #endif
1257 	case SO_MAX_PACING_RATE:
1258 		{
1259 		unsigned long ulval = (val == ~0U) ? ~0UL : (unsigned int)val;
1260 		unsigned long pacing_rate;
1261 
1262 		if (sizeof(ulval) != sizeof(val) &&
1263 		    optlen >= sizeof(ulval) &&
1264 		    copy_from_sockptr(&ulval, optval, sizeof(ulval))) {
1265 			return -EFAULT;
1266 		}
1267 		if (ulval != ~0UL)
1268 			cmpxchg(&sk->sk_pacing_status,
1269 				SK_PACING_NONE,
1270 				SK_PACING_NEEDED);
1271 		/* Pairs with READ_ONCE() from sk_getsockopt() */
1272 		WRITE_ONCE(sk->sk_max_pacing_rate, ulval);
1273 		pacing_rate = READ_ONCE(sk->sk_pacing_rate);
1274 		if (ulval < pacing_rate)
1275 			WRITE_ONCE(sk->sk_pacing_rate, ulval);
1276 		return 0;
1277 		}
1278 	case SO_TXREHASH:
1279 		if (val < -1 || val > 1)
1280 			return -EINVAL;
1281 		if ((u8)val == SOCK_TXREHASH_DEFAULT)
1282 			val = READ_ONCE(sock_net(sk)->core.sysctl_txrehash);
1283 		/* Paired with READ_ONCE() in tcp_rtx_synack()
1284 		 * and sk_getsockopt().
1285 		 */
1286 		WRITE_ONCE(sk->sk_txrehash, (u8)val);
1287 		return 0;
1288 	case SO_PEEK_OFF:
1289 		{
1290 		int (*set_peek_off)(struct sock *sk, int val);
1291 
1292 		set_peek_off = READ_ONCE(sock->ops)->set_peek_off;
1293 		if (set_peek_off)
1294 			ret = set_peek_off(sk, val);
1295 		else
1296 			ret = -EOPNOTSUPP;
1297 		return ret;
1298 		}
1299 #ifdef CONFIG_PAGE_POOL
1300 	case SO_DEVMEM_DONTNEED:
1301 		return sock_devmem_dontneed(sk, optval, optlen);
1302 #endif
1303 	}
1304 
1305 	sockopt_lock_sock(sk);
1306 
1307 	switch (optname) {
1308 	case SO_DEBUG:
1309 		if (val && !sockopt_capable(CAP_NET_ADMIN))
1310 			ret = -EACCES;
1311 		else
1312 			sock_valbool_flag(sk, SOCK_DBG, valbool);
1313 		break;
1314 	case SO_REUSEADDR:
1315 		sk->sk_reuse = (valbool ? SK_CAN_REUSE : SK_NO_REUSE);
1316 		break;
1317 	case SO_REUSEPORT:
1318 		if (valbool && !sk_is_inet(sk))
1319 			ret = -EOPNOTSUPP;
1320 		else
1321 			sk->sk_reuseport = valbool;
1322 		break;
1323 	case SO_DONTROUTE:
1324 		sock_valbool_flag(sk, SOCK_LOCALROUTE, valbool);
1325 		sk_dst_reset(sk);
1326 		break;
1327 	case SO_BROADCAST:
1328 		sock_valbool_flag(sk, SOCK_BROADCAST, valbool);
1329 		break;
1330 	case SO_SNDBUF:
1331 		/* Don't error on this BSD doesn't and if you think
1332 		 * about it this is right. Otherwise apps have to
1333 		 * play 'guess the biggest size' games. RCVBUF/SNDBUF
1334 		 * are treated in BSD as hints
1335 		 */
1336 		val = min_t(u32, val, READ_ONCE(sysctl_wmem_max));
1337 set_sndbuf:
1338 		/* Ensure val * 2 fits into an int, to prevent max_t()
1339 		 * from treating it as a negative value.
1340 		 */
1341 		val = min_t(int, val, INT_MAX / 2);
1342 		sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
1343 		WRITE_ONCE(sk->sk_sndbuf,
1344 			   max_t(int, val * 2, SOCK_MIN_SNDBUF));
1345 		/* Wake up sending tasks if we upped the value. */
1346 		sk->sk_write_space(sk);
1347 		break;
1348 
1349 	case SO_SNDBUFFORCE:
1350 		if (!sockopt_capable(CAP_NET_ADMIN)) {
1351 			ret = -EPERM;
1352 			break;
1353 		}
1354 
1355 		/* No negative values (to prevent underflow, as val will be
1356 		 * multiplied by 2).
1357 		 */
1358 		if (val < 0)
1359 			val = 0;
1360 		goto set_sndbuf;
1361 
1362 	case SO_RCVBUF:
1363 		/* Don't error on this BSD doesn't and if you think
1364 		 * about it this is right. Otherwise apps have to
1365 		 * play 'guess the biggest size' games. RCVBUF/SNDBUF
1366 		 * are treated in BSD as hints
1367 		 */
1368 		__sock_set_rcvbuf(sk, min_t(u32, val, READ_ONCE(sysctl_rmem_max)));
1369 		break;
1370 
1371 	case SO_RCVBUFFORCE:
1372 		if (!sockopt_capable(CAP_NET_ADMIN)) {
1373 			ret = -EPERM;
1374 			break;
1375 		}
1376 
1377 		/* No negative values (to prevent underflow, as val will be
1378 		 * multiplied by 2).
1379 		 */
1380 		__sock_set_rcvbuf(sk, max(val, 0));
1381 		break;
1382 
1383 	case SO_KEEPALIVE:
1384 		if (sk->sk_prot->keepalive)
1385 			sk->sk_prot->keepalive(sk, valbool);
1386 		sock_valbool_flag(sk, SOCK_KEEPOPEN, valbool);
1387 		break;
1388 
1389 	case SO_OOBINLINE:
1390 		sock_valbool_flag(sk, SOCK_URGINLINE, valbool);
1391 		break;
1392 
1393 	case SO_NO_CHECK:
1394 		sk->sk_no_check_tx = valbool;
1395 		break;
1396 
1397 	case SO_LINGER:
1398 		if (optlen < sizeof(ling)) {
1399 			ret = -EINVAL;	/* 1003.1g */
1400 			break;
1401 		}
1402 		if (copy_from_sockptr(&ling, optval, sizeof(ling))) {
1403 			ret = -EFAULT;
1404 			break;
1405 		}
1406 		if (!ling.l_onoff) {
1407 			sock_reset_flag(sk, SOCK_LINGER);
1408 		} else {
1409 			unsigned long t_sec = ling.l_linger;
1410 
1411 			if (t_sec >= MAX_SCHEDULE_TIMEOUT / HZ)
1412 				WRITE_ONCE(sk->sk_lingertime, MAX_SCHEDULE_TIMEOUT);
1413 			else
1414 				WRITE_ONCE(sk->sk_lingertime, t_sec * HZ);
1415 			sock_set_flag(sk, SOCK_LINGER);
1416 		}
1417 		break;
1418 
1419 	case SO_BSDCOMPAT:
1420 		break;
1421 
1422 	case SO_TIMESTAMP_OLD:
1423 	case SO_TIMESTAMP_NEW:
1424 	case SO_TIMESTAMPNS_OLD:
1425 	case SO_TIMESTAMPNS_NEW:
1426 		sock_set_timestamp(sk, optname, valbool);
1427 		break;
1428 
1429 	case SO_TIMESTAMPING_NEW:
1430 	case SO_TIMESTAMPING_OLD:
1431 		if (optlen == sizeof(timestamping)) {
1432 			if (copy_from_sockptr(&timestamping, optval,
1433 					      sizeof(timestamping))) {
1434 				ret = -EFAULT;
1435 				break;
1436 			}
1437 		} else {
1438 			memset(&timestamping, 0, sizeof(timestamping));
1439 			timestamping.flags = val;
1440 		}
1441 		ret = sock_set_timestamping(sk, optname, timestamping);
1442 		break;
1443 
1444 	case SO_RCVLOWAT:
1445 		{
1446 		int (*set_rcvlowat)(struct sock *sk, int val) = NULL;
1447 
1448 		if (val < 0)
1449 			val = INT_MAX;
1450 		if (sock)
1451 			set_rcvlowat = READ_ONCE(sock->ops)->set_rcvlowat;
1452 		if (set_rcvlowat)
1453 			ret = set_rcvlowat(sk, val);
1454 		else
1455 			WRITE_ONCE(sk->sk_rcvlowat, val ? : 1);
1456 		break;
1457 		}
1458 	case SO_RCVTIMEO_OLD:
1459 	case SO_RCVTIMEO_NEW:
1460 		ret = sock_set_timeout(&sk->sk_rcvtimeo, optval,
1461 				       optlen, optname == SO_RCVTIMEO_OLD);
1462 		break;
1463 
1464 	case SO_SNDTIMEO_OLD:
1465 	case SO_SNDTIMEO_NEW:
1466 		ret = sock_set_timeout(&sk->sk_sndtimeo, optval,
1467 				       optlen, optname == SO_SNDTIMEO_OLD);
1468 		break;
1469 
1470 	case SO_ATTACH_FILTER: {
1471 		struct sock_fprog fprog;
1472 
1473 		ret = copy_bpf_fprog_from_user(&fprog, optval, optlen);
1474 		if (!ret)
1475 			ret = sk_attach_filter(&fprog, sk);
1476 		break;
1477 	}
1478 	case SO_ATTACH_BPF:
1479 		ret = -EINVAL;
1480 		if (optlen == sizeof(u32)) {
1481 			u32 ufd;
1482 
1483 			ret = -EFAULT;
1484 			if (copy_from_sockptr(&ufd, optval, sizeof(ufd)))
1485 				break;
1486 
1487 			ret = sk_attach_bpf(ufd, sk);
1488 		}
1489 		break;
1490 
1491 	case SO_ATTACH_REUSEPORT_CBPF: {
1492 		struct sock_fprog fprog;
1493 
1494 		ret = copy_bpf_fprog_from_user(&fprog, optval, optlen);
1495 		if (!ret)
1496 			ret = sk_reuseport_attach_filter(&fprog, sk);
1497 		break;
1498 	}
1499 	case SO_ATTACH_REUSEPORT_EBPF:
1500 		ret = -EINVAL;
1501 		if (optlen == sizeof(u32)) {
1502 			u32 ufd;
1503 
1504 			ret = -EFAULT;
1505 			if (copy_from_sockptr(&ufd, optval, sizeof(ufd)))
1506 				break;
1507 
1508 			ret = sk_reuseport_attach_bpf(ufd, sk);
1509 		}
1510 		break;
1511 
1512 	case SO_DETACH_REUSEPORT_BPF:
1513 		ret = reuseport_detach_prog(sk);
1514 		break;
1515 
1516 	case SO_DETACH_FILTER:
1517 		ret = sk_detach_filter(sk);
1518 		break;
1519 
1520 	case SO_LOCK_FILTER:
1521 		if (sock_flag(sk, SOCK_FILTER_LOCKED) && !valbool)
1522 			ret = -EPERM;
1523 		else
1524 			sock_valbool_flag(sk, SOCK_FILTER_LOCKED, valbool);
1525 		break;
1526 
1527 	case SO_MARK:
1528 		if (!sockopt_ns_capable(sock_net(sk)->user_ns, CAP_NET_RAW) &&
1529 		    !sockopt_ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) {
1530 			ret = -EPERM;
1531 			break;
1532 		}
1533 
1534 		__sock_set_mark(sk, val);
1535 		break;
1536 	case SO_RCVMARK:
1537 		sock_valbool_flag(sk, SOCK_RCVMARK, valbool);
1538 		break;
1539 
1540 	case SO_RCVPRIORITY:
1541 		sock_valbool_flag(sk, SOCK_RCVPRIORITY, valbool);
1542 		break;
1543 
1544 	case SO_RXQ_OVFL:
1545 		sock_valbool_flag(sk, SOCK_RXQ_OVFL, valbool);
1546 		break;
1547 
1548 	case SO_WIFI_STATUS:
1549 		sock_valbool_flag(sk, SOCK_WIFI_STATUS, valbool);
1550 		break;
1551 
1552 	case SO_NOFCS:
1553 		sock_valbool_flag(sk, SOCK_NOFCS, valbool);
1554 		break;
1555 
1556 	case SO_SELECT_ERR_QUEUE:
1557 		sock_valbool_flag(sk, SOCK_SELECT_ERR_QUEUE, valbool);
1558 		break;
1559 
1560 
1561 	case SO_INCOMING_CPU:
1562 		reuseport_update_incoming_cpu(sk, val);
1563 		break;
1564 
1565 	case SO_CNX_ADVICE:
1566 		if (val == 1)
1567 			dst_negative_advice(sk);
1568 		break;
1569 
1570 	case SO_ZEROCOPY:
1571 		if (sk->sk_family == PF_INET || sk->sk_family == PF_INET6) {
1572 			if (!(sk_is_tcp(sk) ||
1573 			      (sk->sk_type == SOCK_DGRAM &&
1574 			       sk->sk_protocol == IPPROTO_UDP)))
1575 				ret = -EOPNOTSUPP;
1576 		} else if (sk->sk_family != PF_RDS) {
1577 			ret = -EOPNOTSUPP;
1578 		}
1579 		if (!ret) {
1580 			if (val < 0 || val > 1)
1581 				ret = -EINVAL;
1582 			else
1583 				sock_valbool_flag(sk, SOCK_ZEROCOPY, valbool);
1584 		}
1585 		break;
1586 
1587 	case SO_TXTIME:
1588 		if (optlen != sizeof(struct sock_txtime)) {
1589 			ret = -EINVAL;
1590 			break;
1591 		} else if (copy_from_sockptr(&sk_txtime, optval,
1592 			   sizeof(struct sock_txtime))) {
1593 			ret = -EFAULT;
1594 			break;
1595 		} else if (sk_txtime.flags & ~SOF_TXTIME_FLAGS_MASK) {
1596 			ret = -EINVAL;
1597 			break;
1598 		}
1599 		/* CLOCK_MONOTONIC is only used by sch_fq, and this packet
1600 		 * scheduler has enough safe guards.
1601 		 */
1602 		if (sk_txtime.clockid != CLOCK_MONOTONIC &&
1603 		    !sockopt_ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) {
1604 			ret = -EPERM;
1605 			break;
1606 		}
1607 
1608 		ret = sockopt_validate_clockid(sk_txtime.clockid);
1609 		if (ret)
1610 			break;
1611 
1612 		sock_valbool_flag(sk, SOCK_TXTIME, true);
1613 		sk->sk_clockid = sk_txtime.clockid;
1614 		sk->sk_txtime_deadline_mode =
1615 			!!(sk_txtime.flags & SOF_TXTIME_DEADLINE_MODE);
1616 		sk->sk_txtime_report_errors =
1617 			!!(sk_txtime.flags & SOF_TXTIME_REPORT_ERRORS);
1618 		break;
1619 
1620 	case SO_BINDTOIFINDEX:
1621 		ret = sock_bindtoindex_locked(sk, val);
1622 		break;
1623 
1624 	case SO_BUF_LOCK:
1625 		if (val & ~SOCK_BUF_LOCK_MASK) {
1626 			ret = -EINVAL;
1627 			break;
1628 		}
1629 		sk->sk_userlocks = val | (sk->sk_userlocks &
1630 					  ~SOCK_BUF_LOCK_MASK);
1631 		break;
1632 
1633 	case SO_RESERVE_MEM:
1634 	{
1635 		int delta;
1636 
1637 		if (val < 0) {
1638 			ret = -EINVAL;
1639 			break;
1640 		}
1641 
1642 		delta = val - sk->sk_reserved_mem;
1643 		if (delta < 0)
1644 			sock_release_reserved_memory(sk, -delta);
1645 		else
1646 			ret = sock_reserve_memory(sk, delta);
1647 		break;
1648 	}
1649 
1650 	default:
1651 		ret = -ENOPROTOOPT;
1652 		break;
1653 	}
1654 	sockopt_release_sock(sk);
1655 	return ret;
1656 }
1657 
sock_setsockopt(struct socket * sock,int level,int optname,sockptr_t optval,unsigned int optlen)1658 int sock_setsockopt(struct socket *sock, int level, int optname,
1659 		    sockptr_t optval, unsigned int optlen)
1660 {
1661 	return sk_setsockopt(sock->sk, level, optname,
1662 			     optval, optlen);
1663 }
1664 EXPORT_SYMBOL(sock_setsockopt);
1665 
sk_get_peer_cred(struct sock * sk)1666 static const struct cred *sk_get_peer_cred(struct sock *sk)
1667 {
1668 	const struct cred *cred;
1669 
1670 	spin_lock(&sk->sk_peer_lock);
1671 	cred = get_cred(sk->sk_peer_cred);
1672 	spin_unlock(&sk->sk_peer_lock);
1673 
1674 	return cred;
1675 }
1676 
cred_to_ucred(struct pid * pid,const struct cred * cred,struct ucred * ucred)1677 static void cred_to_ucred(struct pid *pid, const struct cred *cred,
1678 			  struct ucred *ucred)
1679 {
1680 	ucred->pid = pid_vnr(pid);
1681 	ucred->uid = ucred->gid = -1;
1682 	if (cred) {
1683 		struct user_namespace *current_ns = current_user_ns();
1684 
1685 		ucred->uid = from_kuid_munged(current_ns, cred->euid);
1686 		ucred->gid = from_kgid_munged(current_ns, cred->egid);
1687 	}
1688 }
1689 
groups_to_user(sockptr_t dst,const struct group_info * src)1690 static int groups_to_user(sockptr_t dst, const struct group_info *src)
1691 {
1692 	struct user_namespace *user_ns = current_user_ns();
1693 	int i;
1694 
1695 	for (i = 0; i < src->ngroups; i++) {
1696 		gid_t gid = from_kgid_munged(user_ns, src->gid[i]);
1697 
1698 		if (copy_to_sockptr_offset(dst, i * sizeof(gid), &gid, sizeof(gid)))
1699 			return -EFAULT;
1700 	}
1701 
1702 	return 0;
1703 }
1704 
sk_getsockopt(struct sock * sk,int level,int optname,sockptr_t optval,sockptr_t optlen)1705 int sk_getsockopt(struct sock *sk, int level, int optname,
1706 		  sockptr_t optval, sockptr_t optlen)
1707 {
1708 	struct socket *sock = sk->sk_socket;
1709 
1710 	union {
1711 		int val;
1712 		u64 val64;
1713 		unsigned long ulval;
1714 		struct linger ling;
1715 		struct old_timeval32 tm32;
1716 		struct __kernel_old_timeval tm;
1717 		struct  __kernel_sock_timeval stm;
1718 		struct sock_txtime txtime;
1719 		struct so_timestamping timestamping;
1720 	} v;
1721 
1722 	int lv = sizeof(int);
1723 	int len;
1724 
1725 	if (copy_from_sockptr(&len, optlen, sizeof(int)))
1726 		return -EFAULT;
1727 	if (len < 0)
1728 		return -EINVAL;
1729 
1730 	memset(&v, 0, sizeof(v));
1731 
1732 	switch (optname) {
1733 	case SO_DEBUG:
1734 		v.val = sock_flag(sk, SOCK_DBG);
1735 		break;
1736 
1737 	case SO_DONTROUTE:
1738 		v.val = sock_flag(sk, SOCK_LOCALROUTE);
1739 		break;
1740 
1741 	case SO_BROADCAST:
1742 		v.val = sock_flag(sk, SOCK_BROADCAST);
1743 		break;
1744 
1745 	case SO_SNDBUF:
1746 		v.val = READ_ONCE(sk->sk_sndbuf);
1747 		break;
1748 
1749 	case SO_RCVBUF:
1750 		v.val = READ_ONCE(sk->sk_rcvbuf);
1751 		break;
1752 
1753 	case SO_REUSEADDR:
1754 		v.val = sk->sk_reuse;
1755 		break;
1756 
1757 	case SO_REUSEPORT:
1758 		v.val = sk->sk_reuseport;
1759 		break;
1760 
1761 	case SO_KEEPALIVE:
1762 		v.val = sock_flag(sk, SOCK_KEEPOPEN);
1763 		break;
1764 
1765 	case SO_TYPE:
1766 		v.val = sk->sk_type;
1767 		break;
1768 
1769 	case SO_PROTOCOL:
1770 		v.val = sk->sk_protocol;
1771 		break;
1772 
1773 	case SO_DOMAIN:
1774 		v.val = sk->sk_family;
1775 		break;
1776 
1777 	case SO_ERROR:
1778 		v.val = -sock_error(sk);
1779 		if (v.val == 0)
1780 			v.val = xchg(&sk->sk_err_soft, 0);
1781 		break;
1782 
1783 	case SO_OOBINLINE:
1784 		v.val = sock_flag(sk, SOCK_URGINLINE);
1785 		break;
1786 
1787 	case SO_NO_CHECK:
1788 		v.val = sk->sk_no_check_tx;
1789 		break;
1790 
1791 	case SO_PRIORITY:
1792 		v.val = READ_ONCE(sk->sk_priority);
1793 		break;
1794 
1795 	case SO_LINGER:
1796 		lv		= sizeof(v.ling);
1797 		v.ling.l_onoff	= sock_flag(sk, SOCK_LINGER);
1798 		v.ling.l_linger	= READ_ONCE(sk->sk_lingertime) / HZ;
1799 		break;
1800 
1801 	case SO_BSDCOMPAT:
1802 		break;
1803 
1804 	case SO_TIMESTAMP_OLD:
1805 		v.val = sock_flag(sk, SOCK_RCVTSTAMP) &&
1806 				!sock_flag(sk, SOCK_TSTAMP_NEW) &&
1807 				!sock_flag(sk, SOCK_RCVTSTAMPNS);
1808 		break;
1809 
1810 	case SO_TIMESTAMPNS_OLD:
1811 		v.val = sock_flag(sk, SOCK_RCVTSTAMPNS) && !sock_flag(sk, SOCK_TSTAMP_NEW);
1812 		break;
1813 
1814 	case SO_TIMESTAMP_NEW:
1815 		v.val = sock_flag(sk, SOCK_RCVTSTAMP) && sock_flag(sk, SOCK_TSTAMP_NEW);
1816 		break;
1817 
1818 	case SO_TIMESTAMPNS_NEW:
1819 		v.val = sock_flag(sk, SOCK_RCVTSTAMPNS) && sock_flag(sk, SOCK_TSTAMP_NEW);
1820 		break;
1821 
1822 	case SO_TIMESTAMPING_OLD:
1823 	case SO_TIMESTAMPING_NEW:
1824 		lv = sizeof(v.timestamping);
1825 		/* For the later-added case SO_TIMESTAMPING_NEW: Be strict about only
1826 		 * returning the flags when they were set through the same option.
1827 		 * Don't change the beviour for the old case SO_TIMESTAMPING_OLD.
1828 		 */
1829 		if (optname == SO_TIMESTAMPING_OLD || sock_flag(sk, SOCK_TSTAMP_NEW)) {
1830 			v.timestamping.flags = READ_ONCE(sk->sk_tsflags);
1831 			v.timestamping.bind_phc = READ_ONCE(sk->sk_bind_phc);
1832 		}
1833 		break;
1834 
1835 	case SO_RCVTIMEO_OLD:
1836 	case SO_RCVTIMEO_NEW:
1837 		lv = sock_get_timeout(READ_ONCE(sk->sk_rcvtimeo), &v,
1838 				      SO_RCVTIMEO_OLD == optname);
1839 		break;
1840 
1841 	case SO_SNDTIMEO_OLD:
1842 	case SO_SNDTIMEO_NEW:
1843 		lv = sock_get_timeout(READ_ONCE(sk->sk_sndtimeo), &v,
1844 				      SO_SNDTIMEO_OLD == optname);
1845 		break;
1846 
1847 	case SO_RCVLOWAT:
1848 		v.val = READ_ONCE(sk->sk_rcvlowat);
1849 		break;
1850 
1851 	case SO_SNDLOWAT:
1852 		v.val = 1;
1853 		break;
1854 
1855 	case SO_PASSCRED:
1856 		v.val = !!test_bit(SOCK_PASSCRED, &sock->flags);
1857 		break;
1858 
1859 	case SO_PASSPIDFD:
1860 		v.val = !!test_bit(SOCK_PASSPIDFD, &sock->flags);
1861 		break;
1862 
1863 	case SO_PEERCRED:
1864 	{
1865 		struct ucred peercred;
1866 		if (len > sizeof(peercred))
1867 			len = sizeof(peercred);
1868 
1869 		spin_lock(&sk->sk_peer_lock);
1870 		cred_to_ucred(sk->sk_peer_pid, sk->sk_peer_cred, &peercred);
1871 		spin_unlock(&sk->sk_peer_lock);
1872 
1873 		if (copy_to_sockptr(optval, &peercred, len))
1874 			return -EFAULT;
1875 		goto lenout;
1876 	}
1877 
1878 	case SO_PEERPIDFD:
1879 	{
1880 		struct pid *peer_pid;
1881 		struct file *pidfd_file = NULL;
1882 		int pidfd;
1883 
1884 		if (len > sizeof(pidfd))
1885 			len = sizeof(pidfd);
1886 
1887 		spin_lock(&sk->sk_peer_lock);
1888 		peer_pid = get_pid(sk->sk_peer_pid);
1889 		spin_unlock(&sk->sk_peer_lock);
1890 
1891 		if (!peer_pid)
1892 			return -ENODATA;
1893 
1894 		pidfd = pidfd_prepare(peer_pid, 0, &pidfd_file);
1895 		put_pid(peer_pid);
1896 		if (pidfd < 0)
1897 			return pidfd;
1898 
1899 		if (copy_to_sockptr(optval, &pidfd, len) ||
1900 		    copy_to_sockptr(optlen, &len, sizeof(int))) {
1901 			put_unused_fd(pidfd);
1902 			fput(pidfd_file);
1903 
1904 			return -EFAULT;
1905 		}
1906 
1907 		fd_install(pidfd, pidfd_file);
1908 		return 0;
1909 	}
1910 
1911 	case SO_PEERGROUPS:
1912 	{
1913 		const struct cred *cred;
1914 		int ret, n;
1915 
1916 		cred = sk_get_peer_cred(sk);
1917 		if (!cred)
1918 			return -ENODATA;
1919 
1920 		n = cred->group_info->ngroups;
1921 		if (len < n * sizeof(gid_t)) {
1922 			len = n * sizeof(gid_t);
1923 			put_cred(cred);
1924 			return copy_to_sockptr(optlen, &len, sizeof(int)) ? -EFAULT : -ERANGE;
1925 		}
1926 		len = n * sizeof(gid_t);
1927 
1928 		ret = groups_to_user(optval, cred->group_info);
1929 		put_cred(cred);
1930 		if (ret)
1931 			return ret;
1932 		goto lenout;
1933 	}
1934 
1935 	case SO_PEERNAME:
1936 	{
1937 		struct sockaddr_storage address;
1938 
1939 		lv = READ_ONCE(sock->ops)->getname(sock, (struct sockaddr *)&address, 2);
1940 		if (lv < 0)
1941 			return -ENOTCONN;
1942 		if (lv < len)
1943 			return -EINVAL;
1944 		if (copy_to_sockptr(optval, &address, len))
1945 			return -EFAULT;
1946 		goto lenout;
1947 	}
1948 
1949 	/* Dubious BSD thing... Probably nobody even uses it, but
1950 	 * the UNIX standard wants it for whatever reason... -DaveM
1951 	 */
1952 	case SO_ACCEPTCONN:
1953 		v.val = sk->sk_state == TCP_LISTEN;
1954 		break;
1955 
1956 	case SO_PASSSEC:
1957 		v.val = !!test_bit(SOCK_PASSSEC, &sock->flags);
1958 		break;
1959 
1960 	case SO_PEERSEC:
1961 		return security_socket_getpeersec_stream(sock,
1962 							 optval, optlen, len);
1963 
1964 	case SO_MARK:
1965 		v.val = READ_ONCE(sk->sk_mark);
1966 		break;
1967 
1968 	case SO_RCVMARK:
1969 		v.val = sock_flag(sk, SOCK_RCVMARK);
1970 		break;
1971 
1972 	case SO_RCVPRIORITY:
1973 		v.val = sock_flag(sk, SOCK_RCVPRIORITY);
1974 		break;
1975 
1976 	case SO_RXQ_OVFL:
1977 		v.val = sock_flag(sk, SOCK_RXQ_OVFL);
1978 		break;
1979 
1980 	case SO_WIFI_STATUS:
1981 		v.val = sock_flag(sk, SOCK_WIFI_STATUS);
1982 		break;
1983 
1984 	case SO_PEEK_OFF:
1985 		if (!READ_ONCE(sock->ops)->set_peek_off)
1986 			return -EOPNOTSUPP;
1987 
1988 		v.val = READ_ONCE(sk->sk_peek_off);
1989 		break;
1990 	case SO_NOFCS:
1991 		v.val = sock_flag(sk, SOCK_NOFCS);
1992 		break;
1993 
1994 	case SO_BINDTODEVICE:
1995 		return sock_getbindtodevice(sk, optval, optlen, len);
1996 
1997 	case SO_GET_FILTER:
1998 		len = sk_get_filter(sk, optval, len);
1999 		if (len < 0)
2000 			return len;
2001 
2002 		goto lenout;
2003 
2004 	case SO_LOCK_FILTER:
2005 		v.val = sock_flag(sk, SOCK_FILTER_LOCKED);
2006 		break;
2007 
2008 	case SO_BPF_EXTENSIONS:
2009 		v.val = bpf_tell_extensions();
2010 		break;
2011 
2012 	case SO_SELECT_ERR_QUEUE:
2013 		v.val = sock_flag(sk, SOCK_SELECT_ERR_QUEUE);
2014 		break;
2015 
2016 #ifdef CONFIG_NET_RX_BUSY_POLL
2017 	case SO_BUSY_POLL:
2018 		v.val = READ_ONCE(sk->sk_ll_usec);
2019 		break;
2020 	case SO_PREFER_BUSY_POLL:
2021 		v.val = READ_ONCE(sk->sk_prefer_busy_poll);
2022 		break;
2023 #endif
2024 
2025 	case SO_MAX_PACING_RATE:
2026 		/* The READ_ONCE() pair with the WRITE_ONCE() in sk_setsockopt() */
2027 		if (sizeof(v.ulval) != sizeof(v.val) && len >= sizeof(v.ulval)) {
2028 			lv = sizeof(v.ulval);
2029 			v.ulval = READ_ONCE(sk->sk_max_pacing_rate);
2030 		} else {
2031 			/* 32bit version */
2032 			v.val = min_t(unsigned long, ~0U,
2033 				      READ_ONCE(sk->sk_max_pacing_rate));
2034 		}
2035 		break;
2036 
2037 	case SO_INCOMING_CPU:
2038 		v.val = READ_ONCE(sk->sk_incoming_cpu);
2039 		break;
2040 
2041 	case SO_MEMINFO:
2042 	{
2043 		u32 meminfo[SK_MEMINFO_VARS];
2044 
2045 		sk_get_meminfo(sk, meminfo);
2046 
2047 		len = min_t(unsigned int, len, sizeof(meminfo));
2048 		if (copy_to_sockptr(optval, &meminfo, len))
2049 			return -EFAULT;
2050 
2051 		goto lenout;
2052 	}
2053 
2054 #ifdef CONFIG_NET_RX_BUSY_POLL
2055 	case SO_INCOMING_NAPI_ID:
2056 		v.val = READ_ONCE(sk->sk_napi_id);
2057 
2058 		/* aggregate non-NAPI IDs down to 0 */
2059 		if (!napi_id_valid(v.val))
2060 			v.val = 0;
2061 
2062 		break;
2063 #endif
2064 
2065 	case SO_COOKIE:
2066 		lv = sizeof(u64);
2067 		if (len < lv)
2068 			return -EINVAL;
2069 		v.val64 = sock_gen_cookie(sk);
2070 		break;
2071 
2072 	case SO_ZEROCOPY:
2073 		v.val = sock_flag(sk, SOCK_ZEROCOPY);
2074 		break;
2075 
2076 	case SO_TXTIME:
2077 		lv = sizeof(v.txtime);
2078 		v.txtime.clockid = sk->sk_clockid;
2079 		v.txtime.flags |= sk->sk_txtime_deadline_mode ?
2080 				  SOF_TXTIME_DEADLINE_MODE : 0;
2081 		v.txtime.flags |= sk->sk_txtime_report_errors ?
2082 				  SOF_TXTIME_REPORT_ERRORS : 0;
2083 		break;
2084 
2085 	case SO_BINDTOIFINDEX:
2086 		v.val = READ_ONCE(sk->sk_bound_dev_if);
2087 		break;
2088 
2089 	case SO_NETNS_COOKIE:
2090 		lv = sizeof(u64);
2091 		if (len != lv)
2092 			return -EINVAL;
2093 		v.val64 = sock_net(sk)->net_cookie;
2094 		break;
2095 
2096 	case SO_BUF_LOCK:
2097 		v.val = sk->sk_userlocks & SOCK_BUF_LOCK_MASK;
2098 		break;
2099 
2100 	case SO_RESERVE_MEM:
2101 		v.val = READ_ONCE(sk->sk_reserved_mem);
2102 		break;
2103 
2104 	case SO_TXREHASH:
2105 		/* Paired with WRITE_ONCE() in sk_setsockopt() */
2106 		v.val = READ_ONCE(sk->sk_txrehash);
2107 		break;
2108 
2109 	default:
2110 		/* We implement the SO_SNDLOWAT etc to not be settable
2111 		 * (1003.1g 7).
2112 		 */
2113 		return -ENOPROTOOPT;
2114 	}
2115 
2116 	if (len > lv)
2117 		len = lv;
2118 	if (copy_to_sockptr(optval, &v, len))
2119 		return -EFAULT;
2120 lenout:
2121 	if (copy_to_sockptr(optlen, &len, sizeof(int)))
2122 		return -EFAULT;
2123 	return 0;
2124 }
2125 
2126 /*
2127  * Initialize an sk_lock.
2128  *
2129  * (We also register the sk_lock with the lock validator.)
2130  */
sock_lock_init(struct sock * sk)2131 static inline void sock_lock_init(struct sock *sk)
2132 {
2133 	if (sk->sk_kern_sock)
2134 		sock_lock_init_class_and_name(
2135 			sk,
2136 			af_family_kern_slock_key_strings[sk->sk_family],
2137 			af_family_kern_slock_keys + sk->sk_family,
2138 			af_family_kern_key_strings[sk->sk_family],
2139 			af_family_kern_keys + sk->sk_family);
2140 	else
2141 		sock_lock_init_class_and_name(
2142 			sk,
2143 			af_family_slock_key_strings[sk->sk_family],
2144 			af_family_slock_keys + sk->sk_family,
2145 			af_family_key_strings[sk->sk_family],
2146 			af_family_keys + sk->sk_family);
2147 }
2148 
2149 /*
2150  * Copy all fields from osk to nsk but nsk->sk_refcnt must not change yet,
2151  * even temporarily, because of RCU lookups. sk_node should also be left as is.
2152  * We must not copy fields between sk_dontcopy_begin and sk_dontcopy_end
2153  */
sock_copy(struct sock * nsk,const struct sock * osk)2154 static void sock_copy(struct sock *nsk, const struct sock *osk)
2155 {
2156 	const struct proto *prot = READ_ONCE(osk->sk_prot);
2157 #ifdef CONFIG_SECURITY_NETWORK
2158 	void *sptr = nsk->sk_security;
2159 #endif
2160 
2161 	/* If we move sk_tx_queue_mapping out of the private section,
2162 	 * we must check if sk_tx_queue_clear() is called after
2163 	 * sock_copy() in sk_clone_lock().
2164 	 */
2165 	BUILD_BUG_ON(offsetof(struct sock, sk_tx_queue_mapping) <
2166 		     offsetof(struct sock, sk_dontcopy_begin) ||
2167 		     offsetof(struct sock, sk_tx_queue_mapping) >=
2168 		     offsetof(struct sock, sk_dontcopy_end));
2169 
2170 	memcpy(nsk, osk, offsetof(struct sock, sk_dontcopy_begin));
2171 
2172 	unsafe_memcpy(&nsk->sk_dontcopy_end, &osk->sk_dontcopy_end,
2173 		      prot->obj_size - offsetof(struct sock, sk_dontcopy_end),
2174 		      /* alloc is larger than struct, see sk_prot_alloc() */);
2175 
2176 #ifdef CONFIG_SECURITY_NETWORK
2177 	nsk->sk_security = sptr;
2178 	security_sk_clone(osk, nsk);
2179 #endif
2180 }
2181 
sk_prot_alloc(struct proto * prot,gfp_t priority,int family)2182 static struct sock *sk_prot_alloc(struct proto *prot, gfp_t priority,
2183 		int family)
2184 {
2185 	struct sock *sk;
2186 	struct kmem_cache *slab;
2187 
2188 	slab = prot->slab;
2189 	if (slab != NULL) {
2190 		sk = kmem_cache_alloc(slab, priority & ~__GFP_ZERO);
2191 		if (!sk)
2192 			return sk;
2193 		if (want_init_on_alloc(priority))
2194 			sk_prot_clear_nulls(sk, prot->obj_size);
2195 	} else
2196 		sk = kmalloc(prot->obj_size, priority);
2197 
2198 	if (sk != NULL) {
2199 		if (security_sk_alloc(sk, family, priority))
2200 			goto out_free;
2201 
2202 		if (!try_module_get(prot->owner))
2203 			goto out_free_sec;
2204 	}
2205 
2206 	return sk;
2207 
2208 out_free_sec:
2209 	security_sk_free(sk);
2210 out_free:
2211 	if (slab != NULL)
2212 		kmem_cache_free(slab, sk);
2213 	else
2214 		kfree(sk);
2215 	return NULL;
2216 }
2217 
sk_prot_free(struct proto * prot,struct sock * sk)2218 static void sk_prot_free(struct proto *prot, struct sock *sk)
2219 {
2220 	struct kmem_cache *slab;
2221 	struct module *owner;
2222 
2223 	owner = prot->owner;
2224 	slab = prot->slab;
2225 
2226 	cgroup_sk_free(&sk->sk_cgrp_data);
2227 	mem_cgroup_sk_free(sk);
2228 	security_sk_free(sk);
2229 	if (slab != NULL)
2230 		kmem_cache_free(slab, sk);
2231 	else
2232 		kfree(sk);
2233 	module_put(owner);
2234 }
2235 
2236 /**
2237  *	sk_alloc - All socket objects are allocated here
2238  *	@net: the applicable net namespace
2239  *	@family: protocol family
2240  *	@priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
2241  *	@prot: struct proto associated with this new sock instance
2242  *	@kern: is this to be a kernel socket?
2243  */
sk_alloc(struct net * net,int family,gfp_t priority,struct proto * prot,int kern)2244 struct sock *sk_alloc(struct net *net, int family, gfp_t priority,
2245 		      struct proto *prot, int kern)
2246 {
2247 	struct sock *sk;
2248 
2249 	sk = sk_prot_alloc(prot, priority | __GFP_ZERO, family);
2250 	if (sk) {
2251 		sk->sk_family = family;
2252 		/*
2253 		 * See comment in struct sock definition to understand
2254 		 * why we need sk_prot_creator -acme
2255 		 */
2256 		sk->sk_prot = sk->sk_prot_creator = prot;
2257 		sk->sk_kern_sock = kern;
2258 		sock_lock_init(sk);
2259 		sk->sk_net_refcnt = kern ? 0 : 1;
2260 		if (likely(sk->sk_net_refcnt)) {
2261 			get_net_track(net, &sk->ns_tracker, priority);
2262 			sock_inuse_add(net, 1);
2263 		} else {
2264 			net_passive_inc(net);
2265 			__netns_tracker_alloc(net, &sk->ns_tracker,
2266 					      false, priority);
2267 		}
2268 
2269 		sock_net_set(sk, net);
2270 		refcount_set(&sk->sk_wmem_alloc, 1);
2271 
2272 		mem_cgroup_sk_alloc(sk);
2273 		cgroup_sk_alloc(&sk->sk_cgrp_data);
2274 		sock_update_classid(&sk->sk_cgrp_data);
2275 		sock_update_netprioidx(&sk->sk_cgrp_data);
2276 		sk_tx_queue_clear(sk);
2277 	}
2278 
2279 	return sk;
2280 }
2281 EXPORT_SYMBOL(sk_alloc);
2282 
2283 /* Sockets having SOCK_RCU_FREE will call this function after one RCU
2284  * grace period. This is the case for UDP sockets and TCP listeners.
2285  */
__sk_destruct(struct rcu_head * head)2286 static void __sk_destruct(struct rcu_head *head)
2287 {
2288 	struct sock *sk = container_of(head, struct sock, sk_rcu);
2289 	struct net *net = sock_net(sk);
2290 	struct sk_filter *filter;
2291 
2292 	if (sk->sk_destruct)
2293 		sk->sk_destruct(sk);
2294 
2295 	filter = rcu_dereference_check(sk->sk_filter,
2296 				       refcount_read(&sk->sk_wmem_alloc) == 0);
2297 	if (filter) {
2298 		sk_filter_uncharge(sk, filter);
2299 		RCU_INIT_POINTER(sk->sk_filter, NULL);
2300 	}
2301 
2302 	sock_disable_timestamp(sk, SK_FLAGS_TIMESTAMP);
2303 
2304 #ifdef CONFIG_BPF_SYSCALL
2305 	bpf_sk_storage_free(sk);
2306 #endif
2307 
2308 	if (atomic_read(&sk->sk_omem_alloc))
2309 		pr_debug("%s: optmem leakage (%d bytes) detected\n",
2310 			 __func__, atomic_read(&sk->sk_omem_alloc));
2311 
2312 	if (sk->sk_frag.page) {
2313 		put_page(sk->sk_frag.page);
2314 		sk->sk_frag.page = NULL;
2315 	}
2316 
2317 	/* We do not need to acquire sk->sk_peer_lock, we are the last user. */
2318 	put_cred(sk->sk_peer_cred);
2319 	put_pid(sk->sk_peer_pid);
2320 
2321 	if (likely(sk->sk_net_refcnt)) {
2322 		put_net_track(net, &sk->ns_tracker);
2323 	} else {
2324 		__netns_tracker_free(net, &sk->ns_tracker, false);
2325 		net_passive_dec(net);
2326 	}
2327 	sk_prot_free(sk->sk_prot_creator, sk);
2328 }
2329 
sk_net_refcnt_upgrade(struct sock * sk)2330 void sk_net_refcnt_upgrade(struct sock *sk)
2331 {
2332 	struct net *net = sock_net(sk);
2333 
2334 	WARN_ON_ONCE(sk->sk_net_refcnt);
2335 	__netns_tracker_free(net, &sk->ns_tracker, false);
2336 	net_passive_dec(net);
2337 	sk->sk_net_refcnt = 1;
2338 	get_net_track(net, &sk->ns_tracker, GFP_KERNEL);
2339 	sock_inuse_add(net, 1);
2340 }
2341 EXPORT_SYMBOL_GPL(sk_net_refcnt_upgrade);
2342 
sk_destruct(struct sock * sk)2343 void sk_destruct(struct sock *sk)
2344 {
2345 	bool use_call_rcu = sock_flag(sk, SOCK_RCU_FREE);
2346 
2347 	if (rcu_access_pointer(sk->sk_reuseport_cb)) {
2348 		reuseport_detach_sock(sk);
2349 		use_call_rcu = true;
2350 	}
2351 
2352 	if (use_call_rcu)
2353 		call_rcu(&sk->sk_rcu, __sk_destruct);
2354 	else
2355 		__sk_destruct(&sk->sk_rcu);
2356 }
2357 
__sk_free(struct sock * sk)2358 static void __sk_free(struct sock *sk)
2359 {
2360 	if (likely(sk->sk_net_refcnt))
2361 		sock_inuse_add(sock_net(sk), -1);
2362 
2363 	if (unlikely(sk->sk_net_refcnt && sock_diag_has_destroy_listeners(sk)))
2364 		sock_diag_broadcast_destroy(sk);
2365 	else
2366 		sk_destruct(sk);
2367 }
2368 
sk_free(struct sock * sk)2369 void sk_free(struct sock *sk)
2370 {
2371 	/*
2372 	 * We subtract one from sk_wmem_alloc and can know if
2373 	 * some packets are still in some tx queue.
2374 	 * If not null, sock_wfree() will call __sk_free(sk) later
2375 	 */
2376 	if (refcount_dec_and_test(&sk->sk_wmem_alloc))
2377 		__sk_free(sk);
2378 }
2379 EXPORT_SYMBOL(sk_free);
2380 
sk_init_common(struct sock * sk)2381 static void sk_init_common(struct sock *sk)
2382 {
2383 	skb_queue_head_init(&sk->sk_receive_queue);
2384 	skb_queue_head_init(&sk->sk_write_queue);
2385 	skb_queue_head_init(&sk->sk_error_queue);
2386 
2387 	rwlock_init(&sk->sk_callback_lock);
2388 	lockdep_set_class_and_name(&sk->sk_receive_queue.lock,
2389 			af_rlock_keys + sk->sk_family,
2390 			af_family_rlock_key_strings[sk->sk_family]);
2391 	lockdep_set_class_and_name(&sk->sk_write_queue.lock,
2392 			af_wlock_keys + sk->sk_family,
2393 			af_family_wlock_key_strings[sk->sk_family]);
2394 	lockdep_set_class_and_name(&sk->sk_error_queue.lock,
2395 			af_elock_keys + sk->sk_family,
2396 			af_family_elock_key_strings[sk->sk_family]);
2397 	if (sk->sk_kern_sock)
2398 		lockdep_set_class_and_name(&sk->sk_callback_lock,
2399 			af_kern_callback_keys + sk->sk_family,
2400 			af_family_kern_clock_key_strings[sk->sk_family]);
2401 	else
2402 		lockdep_set_class_and_name(&sk->sk_callback_lock,
2403 			af_callback_keys + sk->sk_family,
2404 			af_family_clock_key_strings[sk->sk_family]);
2405 }
2406 
2407 /**
2408  *	sk_clone_lock - clone a socket, and lock its clone
2409  *	@sk: the socket to clone
2410  *	@priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
2411  *
2412  *	Caller must unlock socket even in error path (bh_unlock_sock(newsk))
2413  */
sk_clone_lock(const struct sock * sk,const gfp_t priority)2414 struct sock *sk_clone_lock(const struct sock *sk, const gfp_t priority)
2415 {
2416 	struct proto *prot = READ_ONCE(sk->sk_prot);
2417 	struct sk_filter *filter;
2418 	bool is_charged = true;
2419 	struct sock *newsk;
2420 
2421 	newsk = sk_prot_alloc(prot, priority, sk->sk_family);
2422 	if (!newsk)
2423 		goto out;
2424 
2425 	sock_copy(newsk, sk);
2426 
2427 	newsk->sk_prot_creator = prot;
2428 
2429 	/* SANITY */
2430 	if (likely(newsk->sk_net_refcnt)) {
2431 		get_net_track(sock_net(newsk), &newsk->ns_tracker, priority);
2432 		sock_inuse_add(sock_net(newsk), 1);
2433 	} else {
2434 		/* Kernel sockets are not elevating the struct net refcount.
2435 		 * Instead, use a tracker to more easily detect if a layer
2436 		 * is not properly dismantling its kernel sockets at netns
2437 		 * destroy time.
2438 		 */
2439 		net_passive_inc(sock_net(newsk));
2440 		__netns_tracker_alloc(sock_net(newsk), &newsk->ns_tracker,
2441 				      false, priority);
2442 	}
2443 	sk_node_init(&newsk->sk_node);
2444 	sock_lock_init(newsk);
2445 	bh_lock_sock(newsk);
2446 	newsk->sk_backlog.head	= newsk->sk_backlog.tail = NULL;
2447 	newsk->sk_backlog.len = 0;
2448 
2449 	atomic_set(&newsk->sk_rmem_alloc, 0);
2450 
2451 	/* sk_wmem_alloc set to one (see sk_free() and sock_wfree()) */
2452 	refcount_set(&newsk->sk_wmem_alloc, 1);
2453 
2454 	atomic_set(&newsk->sk_omem_alloc, 0);
2455 	sk_init_common(newsk);
2456 
2457 	newsk->sk_dst_cache	= NULL;
2458 	newsk->sk_dst_pending_confirm = 0;
2459 	newsk->sk_wmem_queued	= 0;
2460 	newsk->sk_forward_alloc = 0;
2461 	newsk->sk_reserved_mem  = 0;
2462 	atomic_set(&newsk->sk_drops, 0);
2463 	newsk->sk_send_head	= NULL;
2464 	newsk->sk_userlocks	= sk->sk_userlocks & ~SOCK_BINDPORT_LOCK;
2465 	atomic_set(&newsk->sk_zckey, 0);
2466 
2467 	sock_reset_flag(newsk, SOCK_DONE);
2468 
2469 	/* sk->sk_memcg will be populated at accept() time */
2470 	newsk->sk_memcg = NULL;
2471 
2472 	cgroup_sk_clone(&newsk->sk_cgrp_data);
2473 
2474 	rcu_read_lock();
2475 	filter = rcu_dereference(sk->sk_filter);
2476 	if (filter != NULL)
2477 		/* though it's an empty new sock, the charging may fail
2478 		 * if sysctl_optmem_max was changed between creation of
2479 		 * original socket and cloning
2480 		 */
2481 		is_charged = sk_filter_charge(newsk, filter);
2482 	RCU_INIT_POINTER(newsk->sk_filter, filter);
2483 	rcu_read_unlock();
2484 
2485 	if (unlikely(!is_charged || xfrm_sk_clone_policy(newsk, sk))) {
2486 		/* We need to make sure that we don't uncharge the new
2487 		 * socket if we couldn't charge it in the first place
2488 		 * as otherwise we uncharge the parent's filter.
2489 		 */
2490 		if (!is_charged)
2491 			RCU_INIT_POINTER(newsk->sk_filter, NULL);
2492 		sk_free_unlock_clone(newsk);
2493 		newsk = NULL;
2494 		goto out;
2495 	}
2496 	RCU_INIT_POINTER(newsk->sk_reuseport_cb, NULL);
2497 
2498 	if (bpf_sk_storage_clone(sk, newsk)) {
2499 		sk_free_unlock_clone(newsk);
2500 		newsk = NULL;
2501 		goto out;
2502 	}
2503 
2504 	/* Clear sk_user_data if parent had the pointer tagged
2505 	 * as not suitable for copying when cloning.
2506 	 */
2507 	if (sk_user_data_is_nocopy(newsk))
2508 		newsk->sk_user_data = NULL;
2509 
2510 	newsk->sk_err	   = 0;
2511 	newsk->sk_err_soft = 0;
2512 	newsk->sk_priority = 0;
2513 	newsk->sk_incoming_cpu = raw_smp_processor_id();
2514 
2515 	/* Before updating sk_refcnt, we must commit prior changes to memory
2516 	 * (Documentation/RCU/rculist_nulls.rst for details)
2517 	 */
2518 	smp_wmb();
2519 	refcount_set(&newsk->sk_refcnt, 2);
2520 
2521 	sk_set_socket(newsk, NULL);
2522 	sk_tx_queue_clear(newsk);
2523 	RCU_INIT_POINTER(newsk->sk_wq, NULL);
2524 
2525 	if (newsk->sk_prot->sockets_allocated)
2526 		sk_sockets_allocated_inc(newsk);
2527 
2528 	if (sock_needs_netstamp(sk) && newsk->sk_flags & SK_FLAGS_TIMESTAMP)
2529 		net_enable_timestamp();
2530 out:
2531 	return newsk;
2532 }
2533 EXPORT_SYMBOL_GPL(sk_clone_lock);
2534 
sk_free_unlock_clone(struct sock * sk)2535 void sk_free_unlock_clone(struct sock *sk)
2536 {
2537 	/* It is still raw copy of parent, so invalidate
2538 	 * destructor and make plain sk_free() */
2539 	sk->sk_destruct = NULL;
2540 	bh_unlock_sock(sk);
2541 	sk_free(sk);
2542 }
2543 EXPORT_SYMBOL_GPL(sk_free_unlock_clone);
2544 
sk_dst_gso_max_size(struct sock * sk,struct dst_entry * dst)2545 static u32 sk_dst_gso_max_size(struct sock *sk, struct dst_entry *dst)
2546 {
2547 	bool is_ipv6 = false;
2548 	u32 max_size;
2549 
2550 #if IS_ENABLED(CONFIG_IPV6)
2551 	is_ipv6 = (sk->sk_family == AF_INET6 &&
2552 		   !ipv6_addr_v4mapped(&sk->sk_v6_rcv_saddr));
2553 #endif
2554 	/* pairs with the WRITE_ONCE() in netif_set_gso(_ipv4)_max_size() */
2555 	max_size = is_ipv6 ? READ_ONCE(dst->dev->gso_max_size) :
2556 			READ_ONCE(dst->dev->gso_ipv4_max_size);
2557 	if (max_size > GSO_LEGACY_MAX_SIZE && !sk_is_tcp(sk))
2558 		max_size = GSO_LEGACY_MAX_SIZE;
2559 
2560 	return max_size - (MAX_TCP_HEADER + 1);
2561 }
2562 
sk_setup_caps(struct sock * sk,struct dst_entry * dst)2563 void sk_setup_caps(struct sock *sk, struct dst_entry *dst)
2564 {
2565 	u32 max_segs = 1;
2566 
2567 	sk->sk_route_caps = dst->dev->features;
2568 	if (sk_is_tcp(sk)) {
2569 		struct inet_connection_sock *icsk = inet_csk(sk);
2570 
2571 		sk->sk_route_caps |= NETIF_F_GSO;
2572 		icsk->icsk_ack.dst_quick_ack = dst_metric(dst, RTAX_QUICKACK);
2573 	}
2574 	if (sk->sk_route_caps & NETIF_F_GSO)
2575 		sk->sk_route_caps |= NETIF_F_GSO_SOFTWARE;
2576 	if (unlikely(sk->sk_gso_disabled))
2577 		sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
2578 	if (sk_can_gso(sk)) {
2579 		if (dst->header_len && !xfrm_dst_offload_ok(dst)) {
2580 			sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
2581 		} else {
2582 			sk->sk_route_caps |= NETIF_F_SG | NETIF_F_HW_CSUM;
2583 			sk->sk_gso_max_size = sk_dst_gso_max_size(sk, dst);
2584 			/* pairs with the WRITE_ONCE() in netif_set_gso_max_segs() */
2585 			max_segs = max_t(u32, READ_ONCE(dst->dev->gso_max_segs), 1);
2586 		}
2587 	}
2588 	sk->sk_gso_max_segs = max_segs;
2589 	sk_dst_set(sk, dst);
2590 }
2591 EXPORT_SYMBOL_GPL(sk_setup_caps);
2592 
2593 /*
2594  *	Simple resource managers for sockets.
2595  */
2596 
2597 
2598 /*
2599  * Write buffer destructor automatically called from kfree_skb.
2600  */
sock_wfree(struct sk_buff * skb)2601 void sock_wfree(struct sk_buff *skb)
2602 {
2603 	struct sock *sk = skb->sk;
2604 	unsigned int len = skb->truesize;
2605 	bool free;
2606 
2607 	if (!sock_flag(sk, SOCK_USE_WRITE_QUEUE)) {
2608 		if (sock_flag(sk, SOCK_RCU_FREE) &&
2609 		    sk->sk_write_space == sock_def_write_space) {
2610 			rcu_read_lock();
2611 			free = refcount_sub_and_test(len, &sk->sk_wmem_alloc);
2612 			sock_def_write_space_wfree(sk);
2613 			rcu_read_unlock();
2614 			if (unlikely(free))
2615 				__sk_free(sk);
2616 			return;
2617 		}
2618 
2619 		/*
2620 		 * Keep a reference on sk_wmem_alloc, this will be released
2621 		 * after sk_write_space() call
2622 		 */
2623 		WARN_ON(refcount_sub_and_test(len - 1, &sk->sk_wmem_alloc));
2624 		sk->sk_write_space(sk);
2625 		len = 1;
2626 	}
2627 	/*
2628 	 * if sk_wmem_alloc reaches 0, we must finish what sk_free()
2629 	 * could not do because of in-flight packets
2630 	 */
2631 	if (refcount_sub_and_test(len, &sk->sk_wmem_alloc))
2632 		__sk_free(sk);
2633 }
2634 EXPORT_SYMBOL(sock_wfree);
2635 
2636 /* This variant of sock_wfree() is used by TCP,
2637  * since it sets SOCK_USE_WRITE_QUEUE.
2638  */
__sock_wfree(struct sk_buff * skb)2639 void __sock_wfree(struct sk_buff *skb)
2640 {
2641 	struct sock *sk = skb->sk;
2642 
2643 	if (refcount_sub_and_test(skb->truesize, &sk->sk_wmem_alloc))
2644 		__sk_free(sk);
2645 }
2646 
skb_set_owner_w(struct sk_buff * skb,struct sock * sk)2647 void skb_set_owner_w(struct sk_buff *skb, struct sock *sk)
2648 {
2649 	skb_orphan(skb);
2650 #ifdef CONFIG_INET
2651 	if (unlikely(!sk_fullsock(sk)))
2652 		return skb_set_owner_edemux(skb, sk);
2653 #endif
2654 	skb->sk = sk;
2655 	skb->destructor = sock_wfree;
2656 	skb_set_hash_from_sk(skb, sk);
2657 	/*
2658 	 * We used to take a refcount on sk, but following operation
2659 	 * is enough to guarantee sk_free() won't free this sock until
2660 	 * all in-flight packets are completed
2661 	 */
2662 	refcount_add(skb->truesize, &sk->sk_wmem_alloc);
2663 }
2664 EXPORT_SYMBOL(skb_set_owner_w);
2665 
can_skb_orphan_partial(const struct sk_buff * skb)2666 static bool can_skb_orphan_partial(const struct sk_buff *skb)
2667 {
2668 	/* Drivers depend on in-order delivery for crypto offload,
2669 	 * partial orphan breaks out-of-order-OK logic.
2670 	 */
2671 	if (skb_is_decrypted(skb))
2672 		return false;
2673 
2674 	return (skb->destructor == sock_wfree ||
2675 		(IS_ENABLED(CONFIG_INET) && skb->destructor == tcp_wfree));
2676 }
2677 
2678 /* This helper is used by netem, as it can hold packets in its
2679  * delay queue. We want to allow the owner socket to send more
2680  * packets, as if they were already TX completed by a typical driver.
2681  * But we also want to keep skb->sk set because some packet schedulers
2682  * rely on it (sch_fq for example).
2683  */
skb_orphan_partial(struct sk_buff * skb)2684 void skb_orphan_partial(struct sk_buff *skb)
2685 {
2686 	if (skb_is_tcp_pure_ack(skb))
2687 		return;
2688 
2689 	if (can_skb_orphan_partial(skb) && skb_set_owner_sk_safe(skb, skb->sk))
2690 		return;
2691 
2692 	skb_orphan(skb);
2693 }
2694 EXPORT_SYMBOL(skb_orphan_partial);
2695 
2696 /*
2697  * Read buffer destructor automatically called from kfree_skb.
2698  */
sock_rfree(struct sk_buff * skb)2699 void sock_rfree(struct sk_buff *skb)
2700 {
2701 	struct sock *sk = skb->sk;
2702 	unsigned int len = skb->truesize;
2703 
2704 	atomic_sub(len, &sk->sk_rmem_alloc);
2705 	sk_mem_uncharge(sk, len);
2706 }
2707 EXPORT_SYMBOL(sock_rfree);
2708 
2709 /*
2710  * Buffer destructor for skbs that are not used directly in read or write
2711  * path, e.g. for error handler skbs. Automatically called from kfree_skb.
2712  */
sock_efree(struct sk_buff * skb)2713 void sock_efree(struct sk_buff *skb)
2714 {
2715 	sock_put(skb->sk);
2716 }
2717 EXPORT_SYMBOL(sock_efree);
2718 
2719 /* Buffer destructor for prefetch/receive path where reference count may
2720  * not be held, e.g. for listen sockets.
2721  */
2722 #ifdef CONFIG_INET
sock_pfree(struct sk_buff * skb)2723 void sock_pfree(struct sk_buff *skb)
2724 {
2725 	struct sock *sk = skb->sk;
2726 
2727 	if (!sk_is_refcounted(sk))
2728 		return;
2729 
2730 	if (sk->sk_state == TCP_NEW_SYN_RECV && inet_reqsk(sk)->syncookie) {
2731 		inet_reqsk(sk)->rsk_listener = NULL;
2732 		reqsk_free(inet_reqsk(sk));
2733 		return;
2734 	}
2735 
2736 	sock_gen_put(sk);
2737 }
2738 EXPORT_SYMBOL(sock_pfree);
2739 #endif /* CONFIG_INET */
2740 
sock_i_uid(struct sock * sk)2741 kuid_t sock_i_uid(struct sock *sk)
2742 {
2743 	kuid_t uid;
2744 
2745 	read_lock_bh(&sk->sk_callback_lock);
2746 	uid = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_uid : GLOBAL_ROOT_UID;
2747 	read_unlock_bh(&sk->sk_callback_lock);
2748 	return uid;
2749 }
2750 EXPORT_SYMBOL(sock_i_uid);
2751 
__sock_i_ino(struct sock * sk)2752 unsigned long __sock_i_ino(struct sock *sk)
2753 {
2754 	unsigned long ino;
2755 
2756 	read_lock(&sk->sk_callback_lock);
2757 	ino = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_ino : 0;
2758 	read_unlock(&sk->sk_callback_lock);
2759 	return ino;
2760 }
2761 EXPORT_SYMBOL(__sock_i_ino);
2762 
sock_i_ino(struct sock * sk)2763 unsigned long sock_i_ino(struct sock *sk)
2764 {
2765 	unsigned long ino;
2766 
2767 	local_bh_disable();
2768 	ino = __sock_i_ino(sk);
2769 	local_bh_enable();
2770 	return ino;
2771 }
2772 EXPORT_SYMBOL(sock_i_ino);
2773 
2774 /*
2775  * Allocate a skb from the socket's send buffer.
2776  */
sock_wmalloc(struct sock * sk,unsigned long size,int force,gfp_t priority)2777 struct sk_buff *sock_wmalloc(struct sock *sk, unsigned long size, int force,
2778 			     gfp_t priority)
2779 {
2780 	if (force ||
2781 	    refcount_read(&sk->sk_wmem_alloc) < READ_ONCE(sk->sk_sndbuf)) {
2782 		struct sk_buff *skb = alloc_skb(size, priority);
2783 
2784 		if (skb) {
2785 			skb_set_owner_w(skb, sk);
2786 			return skb;
2787 		}
2788 	}
2789 	return NULL;
2790 }
2791 EXPORT_SYMBOL(sock_wmalloc);
2792 
sock_ofree(struct sk_buff * skb)2793 static void sock_ofree(struct sk_buff *skb)
2794 {
2795 	struct sock *sk = skb->sk;
2796 
2797 	atomic_sub(skb->truesize, &sk->sk_omem_alloc);
2798 }
2799 
sock_omalloc(struct sock * sk,unsigned long size,gfp_t priority)2800 struct sk_buff *sock_omalloc(struct sock *sk, unsigned long size,
2801 			     gfp_t priority)
2802 {
2803 	struct sk_buff *skb;
2804 
2805 	/* small safe race: SKB_TRUESIZE may differ from final skb->truesize */
2806 	if (atomic_read(&sk->sk_omem_alloc) + SKB_TRUESIZE(size) >
2807 	    READ_ONCE(sock_net(sk)->core.sysctl_optmem_max))
2808 		return NULL;
2809 
2810 	skb = alloc_skb(size, priority);
2811 	if (!skb)
2812 		return NULL;
2813 
2814 	atomic_add(skb->truesize, &sk->sk_omem_alloc);
2815 	skb->sk = sk;
2816 	skb->destructor = sock_ofree;
2817 	return skb;
2818 }
2819 
2820 /*
2821  * Allocate a memory block from the socket's option memory buffer.
2822  */
sock_kmalloc(struct sock * sk,int size,gfp_t priority)2823 void *sock_kmalloc(struct sock *sk, int size, gfp_t priority)
2824 {
2825 	int optmem_max = READ_ONCE(sock_net(sk)->core.sysctl_optmem_max);
2826 
2827 	if ((unsigned int)size <= optmem_max &&
2828 	    atomic_read(&sk->sk_omem_alloc) + size < optmem_max) {
2829 		void *mem;
2830 		/* First do the add, to avoid the race if kmalloc
2831 		 * might sleep.
2832 		 */
2833 		atomic_add(size, &sk->sk_omem_alloc);
2834 		mem = kmalloc(size, priority);
2835 		if (mem)
2836 			return mem;
2837 		atomic_sub(size, &sk->sk_omem_alloc);
2838 	}
2839 	return NULL;
2840 }
2841 EXPORT_SYMBOL(sock_kmalloc);
2842 
2843 /*
2844  * Duplicate the input "src" memory block using the socket's
2845  * option memory buffer.
2846  */
sock_kmemdup(struct sock * sk,const void * src,int size,gfp_t priority)2847 void *sock_kmemdup(struct sock *sk, const void *src,
2848 		   int size, gfp_t priority)
2849 {
2850 	void *mem;
2851 
2852 	mem = sock_kmalloc(sk, size, priority);
2853 	if (mem)
2854 		memcpy(mem, src, size);
2855 	return mem;
2856 }
2857 EXPORT_SYMBOL(sock_kmemdup);
2858 
2859 /* Free an option memory block. Note, we actually want the inline
2860  * here as this allows gcc to detect the nullify and fold away the
2861  * condition entirely.
2862  */
__sock_kfree_s(struct sock * sk,void * mem,int size,const bool nullify)2863 static inline void __sock_kfree_s(struct sock *sk, void *mem, int size,
2864 				  const bool nullify)
2865 {
2866 	if (WARN_ON_ONCE(!mem))
2867 		return;
2868 	if (nullify)
2869 		kfree_sensitive(mem);
2870 	else
2871 		kfree(mem);
2872 	atomic_sub(size, &sk->sk_omem_alloc);
2873 }
2874 
sock_kfree_s(struct sock * sk,void * mem,int size)2875 void sock_kfree_s(struct sock *sk, void *mem, int size)
2876 {
2877 	__sock_kfree_s(sk, mem, size, false);
2878 }
2879 EXPORT_SYMBOL(sock_kfree_s);
2880 
sock_kzfree_s(struct sock * sk,void * mem,int size)2881 void sock_kzfree_s(struct sock *sk, void *mem, int size)
2882 {
2883 	__sock_kfree_s(sk, mem, size, true);
2884 }
2885 EXPORT_SYMBOL(sock_kzfree_s);
2886 
2887 /* It is almost wait_for_tcp_memory minus release_sock/lock_sock.
2888    I think, these locks should be removed for datagram sockets.
2889  */
sock_wait_for_wmem(struct sock * sk,long timeo)2890 static long sock_wait_for_wmem(struct sock *sk, long timeo)
2891 {
2892 	DEFINE_WAIT(wait);
2893 
2894 	sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
2895 	for (;;) {
2896 		if (!timeo)
2897 			break;
2898 		if (signal_pending(current))
2899 			break;
2900 		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
2901 		prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
2902 		if (refcount_read(&sk->sk_wmem_alloc) < READ_ONCE(sk->sk_sndbuf))
2903 			break;
2904 		if (READ_ONCE(sk->sk_shutdown) & SEND_SHUTDOWN)
2905 			break;
2906 		if (READ_ONCE(sk->sk_err))
2907 			break;
2908 		timeo = schedule_timeout(timeo);
2909 	}
2910 	finish_wait(sk_sleep(sk), &wait);
2911 	return timeo;
2912 }
2913 
2914 
2915 /*
2916  *	Generic send/receive buffer handlers
2917  */
2918 
sock_alloc_send_pskb(struct sock * sk,unsigned long header_len,unsigned long data_len,int noblock,int * errcode,int max_page_order)2919 struct sk_buff *sock_alloc_send_pskb(struct sock *sk, unsigned long header_len,
2920 				     unsigned long data_len, int noblock,
2921 				     int *errcode, int max_page_order)
2922 {
2923 	struct sk_buff *skb;
2924 	long timeo;
2925 	int err;
2926 
2927 	timeo = sock_sndtimeo(sk, noblock);
2928 	for (;;) {
2929 		err = sock_error(sk);
2930 		if (err != 0)
2931 			goto failure;
2932 
2933 		err = -EPIPE;
2934 		if (READ_ONCE(sk->sk_shutdown) & SEND_SHUTDOWN)
2935 			goto failure;
2936 
2937 		if (sk_wmem_alloc_get(sk) < READ_ONCE(sk->sk_sndbuf))
2938 			break;
2939 
2940 		sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
2941 		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
2942 		err = -EAGAIN;
2943 		if (!timeo)
2944 			goto failure;
2945 		if (signal_pending(current))
2946 			goto interrupted;
2947 		timeo = sock_wait_for_wmem(sk, timeo);
2948 	}
2949 	skb = alloc_skb_with_frags(header_len, data_len, max_page_order,
2950 				   errcode, sk->sk_allocation);
2951 	if (skb)
2952 		skb_set_owner_w(skb, sk);
2953 	return skb;
2954 
2955 interrupted:
2956 	err = sock_intr_errno(timeo);
2957 failure:
2958 	*errcode = err;
2959 	return NULL;
2960 }
2961 EXPORT_SYMBOL(sock_alloc_send_pskb);
2962 
__sock_cmsg_send(struct sock * sk,struct cmsghdr * cmsg,struct sockcm_cookie * sockc)2963 int __sock_cmsg_send(struct sock *sk, struct cmsghdr *cmsg,
2964 		     struct sockcm_cookie *sockc)
2965 {
2966 	u32 tsflags;
2967 
2968 	BUILD_BUG_ON(SOF_TIMESTAMPING_LAST == (1 << 31));
2969 
2970 	switch (cmsg->cmsg_type) {
2971 	case SO_MARK:
2972 		if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_RAW) &&
2973 		    !ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
2974 			return -EPERM;
2975 		if (cmsg->cmsg_len != CMSG_LEN(sizeof(u32)))
2976 			return -EINVAL;
2977 		sockc->mark = *(u32 *)CMSG_DATA(cmsg);
2978 		break;
2979 	case SO_TIMESTAMPING_OLD:
2980 	case SO_TIMESTAMPING_NEW:
2981 		if (cmsg->cmsg_len != CMSG_LEN(sizeof(u32)))
2982 			return -EINVAL;
2983 
2984 		tsflags = *(u32 *)CMSG_DATA(cmsg);
2985 		if (tsflags & ~SOF_TIMESTAMPING_TX_RECORD_MASK)
2986 			return -EINVAL;
2987 
2988 		sockc->tsflags &= ~SOF_TIMESTAMPING_TX_RECORD_MASK;
2989 		sockc->tsflags |= tsflags;
2990 		break;
2991 	case SCM_TXTIME:
2992 		if (!sock_flag(sk, SOCK_TXTIME))
2993 			return -EINVAL;
2994 		if (cmsg->cmsg_len != CMSG_LEN(sizeof(u64)))
2995 			return -EINVAL;
2996 		sockc->transmit_time = get_unaligned((u64 *)CMSG_DATA(cmsg));
2997 		break;
2998 	case SCM_TS_OPT_ID:
2999 		if (sk_is_tcp(sk))
3000 			return -EINVAL;
3001 		tsflags = READ_ONCE(sk->sk_tsflags);
3002 		if (!(tsflags & SOF_TIMESTAMPING_OPT_ID))
3003 			return -EINVAL;
3004 		if (cmsg->cmsg_len != CMSG_LEN(sizeof(u32)))
3005 			return -EINVAL;
3006 		sockc->ts_opt_id = *(u32 *)CMSG_DATA(cmsg);
3007 		sockc->tsflags |= SOCKCM_FLAG_TS_OPT_ID;
3008 		break;
3009 	/* SCM_RIGHTS and SCM_CREDENTIALS are semantically in SOL_UNIX. */
3010 	case SCM_RIGHTS:
3011 	case SCM_CREDENTIALS:
3012 		break;
3013 	case SO_PRIORITY:
3014 		if (cmsg->cmsg_len != CMSG_LEN(sizeof(u32)))
3015 			return -EINVAL;
3016 		if (!sk_set_prio_allowed(sk, *(u32 *)CMSG_DATA(cmsg)))
3017 			return -EPERM;
3018 		sockc->priority = *(u32 *)CMSG_DATA(cmsg);
3019 		break;
3020 	default:
3021 		return -EINVAL;
3022 	}
3023 	return 0;
3024 }
3025 EXPORT_SYMBOL(__sock_cmsg_send);
3026 
sock_cmsg_send(struct sock * sk,struct msghdr * msg,struct sockcm_cookie * sockc)3027 int sock_cmsg_send(struct sock *sk, struct msghdr *msg,
3028 		   struct sockcm_cookie *sockc)
3029 {
3030 	struct cmsghdr *cmsg;
3031 	int ret;
3032 
3033 	for_each_cmsghdr(cmsg, msg) {
3034 		if (!CMSG_OK(msg, cmsg))
3035 			return -EINVAL;
3036 		if (cmsg->cmsg_level != SOL_SOCKET)
3037 			continue;
3038 		ret = __sock_cmsg_send(sk, cmsg, sockc);
3039 		if (ret)
3040 			return ret;
3041 	}
3042 	return 0;
3043 }
3044 EXPORT_SYMBOL(sock_cmsg_send);
3045 
sk_enter_memory_pressure(struct sock * sk)3046 static void sk_enter_memory_pressure(struct sock *sk)
3047 {
3048 	if (!sk->sk_prot->enter_memory_pressure)
3049 		return;
3050 
3051 	sk->sk_prot->enter_memory_pressure(sk);
3052 }
3053 
sk_leave_memory_pressure(struct sock * sk)3054 static void sk_leave_memory_pressure(struct sock *sk)
3055 {
3056 	if (sk->sk_prot->leave_memory_pressure) {
3057 		INDIRECT_CALL_INET_1(sk->sk_prot->leave_memory_pressure,
3058 				     tcp_leave_memory_pressure, sk);
3059 	} else {
3060 		unsigned long *memory_pressure = sk->sk_prot->memory_pressure;
3061 
3062 		if (memory_pressure && READ_ONCE(*memory_pressure))
3063 			WRITE_ONCE(*memory_pressure, 0);
3064 	}
3065 }
3066 
3067 DEFINE_STATIC_KEY_FALSE(net_high_order_alloc_disable_key);
3068 
3069 /**
3070  * skb_page_frag_refill - check that a page_frag contains enough room
3071  * @sz: minimum size of the fragment we want to get
3072  * @pfrag: pointer to page_frag
3073  * @gfp: priority for memory allocation
3074  *
3075  * Note: While this allocator tries to use high order pages, there is
3076  * no guarantee that allocations succeed. Therefore, @sz MUST be
3077  * less or equal than PAGE_SIZE.
3078  */
skb_page_frag_refill(unsigned int sz,struct page_frag * pfrag,gfp_t gfp)3079 bool skb_page_frag_refill(unsigned int sz, struct page_frag *pfrag, gfp_t gfp)
3080 {
3081 	if (pfrag->page) {
3082 		if (page_ref_count(pfrag->page) == 1) {
3083 			pfrag->offset = 0;
3084 			return true;
3085 		}
3086 		if (pfrag->offset + sz <= pfrag->size)
3087 			return true;
3088 		put_page(pfrag->page);
3089 	}
3090 
3091 	pfrag->offset = 0;
3092 	if (SKB_FRAG_PAGE_ORDER &&
3093 	    !static_branch_unlikely(&net_high_order_alloc_disable_key)) {
3094 		/* Avoid direct reclaim but allow kswapd to wake */
3095 		pfrag->page = alloc_pages((gfp & ~__GFP_DIRECT_RECLAIM) |
3096 					  __GFP_COMP | __GFP_NOWARN |
3097 					  __GFP_NORETRY,
3098 					  SKB_FRAG_PAGE_ORDER);
3099 		if (likely(pfrag->page)) {
3100 			pfrag->size = PAGE_SIZE << SKB_FRAG_PAGE_ORDER;
3101 			return true;
3102 		}
3103 	}
3104 	pfrag->page = alloc_page(gfp);
3105 	if (likely(pfrag->page)) {
3106 		pfrag->size = PAGE_SIZE;
3107 		return true;
3108 	}
3109 	return false;
3110 }
3111 EXPORT_SYMBOL(skb_page_frag_refill);
3112 
sk_page_frag_refill(struct sock * sk,struct page_frag * pfrag)3113 bool sk_page_frag_refill(struct sock *sk, struct page_frag *pfrag)
3114 {
3115 	if (likely(skb_page_frag_refill(32U, pfrag, sk->sk_allocation)))
3116 		return true;
3117 
3118 	sk_enter_memory_pressure(sk);
3119 	sk_stream_moderate_sndbuf(sk);
3120 	return false;
3121 }
3122 EXPORT_SYMBOL(sk_page_frag_refill);
3123 
__lock_sock(struct sock * sk)3124 void __lock_sock(struct sock *sk)
3125 	__releases(&sk->sk_lock.slock)
3126 	__acquires(&sk->sk_lock.slock)
3127 {
3128 	DEFINE_WAIT(wait);
3129 
3130 	for (;;) {
3131 		prepare_to_wait_exclusive(&sk->sk_lock.wq, &wait,
3132 					TASK_UNINTERRUPTIBLE);
3133 		spin_unlock_bh(&sk->sk_lock.slock);
3134 		schedule();
3135 		spin_lock_bh(&sk->sk_lock.slock);
3136 		if (!sock_owned_by_user(sk))
3137 			break;
3138 	}
3139 	finish_wait(&sk->sk_lock.wq, &wait);
3140 }
3141 
__release_sock(struct sock * sk)3142 void __release_sock(struct sock *sk)
3143 	__releases(&sk->sk_lock.slock)
3144 	__acquires(&sk->sk_lock.slock)
3145 {
3146 	struct sk_buff *skb, *next;
3147 
3148 	while ((skb = sk->sk_backlog.head) != NULL) {
3149 		sk->sk_backlog.head = sk->sk_backlog.tail = NULL;
3150 
3151 		spin_unlock_bh(&sk->sk_lock.slock);
3152 
3153 		do {
3154 			next = skb->next;
3155 			prefetch(next);
3156 			DEBUG_NET_WARN_ON_ONCE(skb_dst_is_noref(skb));
3157 			skb_mark_not_on_list(skb);
3158 			sk_backlog_rcv(sk, skb);
3159 
3160 			cond_resched();
3161 
3162 			skb = next;
3163 		} while (skb != NULL);
3164 
3165 		spin_lock_bh(&sk->sk_lock.slock);
3166 	}
3167 
3168 	/*
3169 	 * Doing the zeroing here guarantee we can not loop forever
3170 	 * while a wild producer attempts to flood us.
3171 	 */
3172 	sk->sk_backlog.len = 0;
3173 }
3174 
__sk_flush_backlog(struct sock * sk)3175 void __sk_flush_backlog(struct sock *sk)
3176 {
3177 	spin_lock_bh(&sk->sk_lock.slock);
3178 	__release_sock(sk);
3179 
3180 	if (sk->sk_prot->release_cb)
3181 		INDIRECT_CALL_INET_1(sk->sk_prot->release_cb,
3182 				     tcp_release_cb, sk);
3183 
3184 	spin_unlock_bh(&sk->sk_lock.slock);
3185 }
3186 EXPORT_SYMBOL_GPL(__sk_flush_backlog);
3187 
3188 /**
3189  * sk_wait_data - wait for data to arrive at sk_receive_queue
3190  * @sk:    sock to wait on
3191  * @timeo: for how long
3192  * @skb:   last skb seen on sk_receive_queue
3193  *
3194  * Now socket state including sk->sk_err is changed only under lock,
3195  * hence we may omit checks after joining wait queue.
3196  * We check receive queue before schedule() only as optimization;
3197  * it is very likely that release_sock() added new data.
3198  */
sk_wait_data(struct sock * sk,long * timeo,const struct sk_buff * skb)3199 int sk_wait_data(struct sock *sk, long *timeo, const struct sk_buff *skb)
3200 {
3201 	DEFINE_WAIT_FUNC(wait, woken_wake_function);
3202 	int rc;
3203 
3204 	add_wait_queue(sk_sleep(sk), &wait);
3205 	sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
3206 	rc = sk_wait_event(sk, timeo, skb_peek_tail(&sk->sk_receive_queue) != skb, &wait);
3207 	sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
3208 	remove_wait_queue(sk_sleep(sk), &wait);
3209 	return rc;
3210 }
3211 EXPORT_SYMBOL(sk_wait_data);
3212 
3213 /**
3214  *	__sk_mem_raise_allocated - increase memory_allocated
3215  *	@sk: socket
3216  *	@size: memory size to allocate
3217  *	@amt: pages to allocate
3218  *	@kind: allocation type
3219  *
3220  *	Similar to __sk_mem_schedule(), but does not update sk_forward_alloc.
3221  *
3222  *	Unlike the globally shared limits among the sockets under same protocol,
3223  *	consuming the budget of a memcg won't have direct effect on other ones.
3224  *	So be optimistic about memcg's tolerance, and leave the callers to decide
3225  *	whether or not to raise allocated through sk_under_memory_pressure() or
3226  *	its variants.
3227  */
__sk_mem_raise_allocated(struct sock * sk,int size,int amt,int kind)3228 int __sk_mem_raise_allocated(struct sock *sk, int size, int amt, int kind)
3229 {
3230 	struct mem_cgroup *memcg = mem_cgroup_sockets_enabled ? sk->sk_memcg : NULL;
3231 	struct proto *prot = sk->sk_prot;
3232 	bool charged = false;
3233 	long allocated;
3234 
3235 	sk_memory_allocated_add(sk, amt);
3236 	allocated = sk_memory_allocated(sk);
3237 
3238 	if (memcg) {
3239 		if (!mem_cgroup_charge_skmem(memcg, amt, gfp_memcg_charge()))
3240 			goto suppress_allocation;
3241 		charged = true;
3242 	}
3243 
3244 	/* Under limit. */
3245 	if (allocated <= sk_prot_mem_limits(sk, 0)) {
3246 		sk_leave_memory_pressure(sk);
3247 		return 1;
3248 	}
3249 
3250 	/* Under pressure. */
3251 	if (allocated > sk_prot_mem_limits(sk, 1))
3252 		sk_enter_memory_pressure(sk);
3253 
3254 	/* Over hard limit. */
3255 	if (allocated > sk_prot_mem_limits(sk, 2))
3256 		goto suppress_allocation;
3257 
3258 	/* Guarantee minimum buffer size under pressure (either global
3259 	 * or memcg) to make sure features described in RFC 7323 (TCP
3260 	 * Extensions for High Performance) work properly.
3261 	 *
3262 	 * This rule does NOT stand when exceeds global or memcg's hard
3263 	 * limit, or else a DoS attack can be taken place by spawning
3264 	 * lots of sockets whose usage are under minimum buffer size.
3265 	 */
3266 	if (kind == SK_MEM_RECV) {
3267 		if (atomic_read(&sk->sk_rmem_alloc) < sk_get_rmem0(sk, prot))
3268 			return 1;
3269 
3270 	} else { /* SK_MEM_SEND */
3271 		int wmem0 = sk_get_wmem0(sk, prot);
3272 
3273 		if (sk->sk_type == SOCK_STREAM) {
3274 			if (sk->sk_wmem_queued < wmem0)
3275 				return 1;
3276 		} else if (refcount_read(&sk->sk_wmem_alloc) < wmem0) {
3277 				return 1;
3278 		}
3279 	}
3280 
3281 	if (sk_has_memory_pressure(sk)) {
3282 		u64 alloc;
3283 
3284 		/* The following 'average' heuristic is within the
3285 		 * scope of global accounting, so it only makes
3286 		 * sense for global memory pressure.
3287 		 */
3288 		if (!sk_under_global_memory_pressure(sk))
3289 			return 1;
3290 
3291 		/* Try to be fair among all the sockets under global
3292 		 * pressure by allowing the ones that below average
3293 		 * usage to raise.
3294 		 */
3295 		alloc = sk_sockets_allocated_read_positive(sk);
3296 		if (sk_prot_mem_limits(sk, 2) > alloc *
3297 		    sk_mem_pages(sk->sk_wmem_queued +
3298 				 atomic_read(&sk->sk_rmem_alloc) +
3299 				 sk->sk_forward_alloc))
3300 			return 1;
3301 	}
3302 
3303 suppress_allocation:
3304 
3305 	if (kind == SK_MEM_SEND && sk->sk_type == SOCK_STREAM) {
3306 		sk_stream_moderate_sndbuf(sk);
3307 
3308 		/* Fail only if socket is _under_ its sndbuf.
3309 		 * In this case we cannot block, so that we have to fail.
3310 		 */
3311 		if (sk->sk_wmem_queued + size >= sk->sk_sndbuf) {
3312 			/* Force charge with __GFP_NOFAIL */
3313 			if (memcg && !charged) {
3314 				mem_cgroup_charge_skmem(memcg, amt,
3315 					gfp_memcg_charge() | __GFP_NOFAIL);
3316 			}
3317 			return 1;
3318 		}
3319 	}
3320 
3321 	if (kind == SK_MEM_SEND || (kind == SK_MEM_RECV && charged))
3322 		trace_sock_exceed_buf_limit(sk, prot, allocated, kind);
3323 
3324 	sk_memory_allocated_sub(sk, amt);
3325 
3326 	if (charged)
3327 		mem_cgroup_uncharge_skmem(memcg, amt);
3328 
3329 	return 0;
3330 }
3331 
3332 /**
3333  *	__sk_mem_schedule - increase sk_forward_alloc and memory_allocated
3334  *	@sk: socket
3335  *	@size: memory size to allocate
3336  *	@kind: allocation type
3337  *
3338  *	If kind is SK_MEM_SEND, it means wmem allocation. Otherwise it means
3339  *	rmem allocation. This function assumes that protocols which have
3340  *	memory_pressure use sk_wmem_queued as write buffer accounting.
3341  */
__sk_mem_schedule(struct sock * sk,int size,int kind)3342 int __sk_mem_schedule(struct sock *sk, int size, int kind)
3343 {
3344 	int ret, amt = sk_mem_pages(size);
3345 
3346 	sk_forward_alloc_add(sk, amt << PAGE_SHIFT);
3347 	ret = __sk_mem_raise_allocated(sk, size, amt, kind);
3348 	if (!ret)
3349 		sk_forward_alloc_add(sk, -(amt << PAGE_SHIFT));
3350 	return ret;
3351 }
3352 EXPORT_SYMBOL(__sk_mem_schedule);
3353 
3354 /**
3355  *	__sk_mem_reduce_allocated - reclaim memory_allocated
3356  *	@sk: socket
3357  *	@amount: number of quanta
3358  *
3359  *	Similar to __sk_mem_reclaim(), but does not update sk_forward_alloc
3360  */
__sk_mem_reduce_allocated(struct sock * sk,int amount)3361 void __sk_mem_reduce_allocated(struct sock *sk, int amount)
3362 {
3363 	sk_memory_allocated_sub(sk, amount);
3364 
3365 	if (mem_cgroup_sockets_enabled && sk->sk_memcg)
3366 		mem_cgroup_uncharge_skmem(sk->sk_memcg, amount);
3367 
3368 	if (sk_under_global_memory_pressure(sk) &&
3369 	    (sk_memory_allocated(sk) < sk_prot_mem_limits(sk, 0)))
3370 		sk_leave_memory_pressure(sk);
3371 }
3372 
3373 /**
3374  *	__sk_mem_reclaim - reclaim sk_forward_alloc and memory_allocated
3375  *	@sk: socket
3376  *	@amount: number of bytes (rounded down to a PAGE_SIZE multiple)
3377  */
__sk_mem_reclaim(struct sock * sk,int amount)3378 void __sk_mem_reclaim(struct sock *sk, int amount)
3379 {
3380 	amount >>= PAGE_SHIFT;
3381 	sk_forward_alloc_add(sk, -(amount << PAGE_SHIFT));
3382 	__sk_mem_reduce_allocated(sk, amount);
3383 }
3384 EXPORT_SYMBOL(__sk_mem_reclaim);
3385 
sk_set_peek_off(struct sock * sk,int val)3386 int sk_set_peek_off(struct sock *sk, int val)
3387 {
3388 	WRITE_ONCE(sk->sk_peek_off, val);
3389 	return 0;
3390 }
3391 EXPORT_SYMBOL_GPL(sk_set_peek_off);
3392 
3393 /*
3394  * Set of default routines for initialising struct proto_ops when
3395  * the protocol does not support a particular function. In certain
3396  * cases where it makes no sense for a protocol to have a "do nothing"
3397  * function, some default processing is provided.
3398  */
3399 
sock_no_bind(struct socket * sock,struct sockaddr * saddr,int len)3400 int sock_no_bind(struct socket *sock, struct sockaddr *saddr, int len)
3401 {
3402 	return -EOPNOTSUPP;
3403 }
3404 EXPORT_SYMBOL(sock_no_bind);
3405 
sock_no_connect(struct socket * sock,struct sockaddr * saddr,int len,int flags)3406 int sock_no_connect(struct socket *sock, struct sockaddr *saddr,
3407 		    int len, int flags)
3408 {
3409 	return -EOPNOTSUPP;
3410 }
3411 EXPORT_SYMBOL(sock_no_connect);
3412 
sock_no_socketpair(struct socket * sock1,struct socket * sock2)3413 int sock_no_socketpair(struct socket *sock1, struct socket *sock2)
3414 {
3415 	return -EOPNOTSUPP;
3416 }
3417 EXPORT_SYMBOL(sock_no_socketpair);
3418 
sock_no_accept(struct socket * sock,struct socket * newsock,struct proto_accept_arg * arg)3419 int sock_no_accept(struct socket *sock, struct socket *newsock,
3420 		   struct proto_accept_arg *arg)
3421 {
3422 	return -EOPNOTSUPP;
3423 }
3424 EXPORT_SYMBOL(sock_no_accept);
3425 
sock_no_getname(struct socket * sock,struct sockaddr * saddr,int peer)3426 int sock_no_getname(struct socket *sock, struct sockaddr *saddr,
3427 		    int peer)
3428 {
3429 	return -EOPNOTSUPP;
3430 }
3431 EXPORT_SYMBOL(sock_no_getname);
3432 
sock_no_ioctl(struct socket * sock,unsigned int cmd,unsigned long arg)3433 int sock_no_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
3434 {
3435 	return -EOPNOTSUPP;
3436 }
3437 EXPORT_SYMBOL(sock_no_ioctl);
3438 
sock_no_listen(struct socket * sock,int backlog)3439 int sock_no_listen(struct socket *sock, int backlog)
3440 {
3441 	return -EOPNOTSUPP;
3442 }
3443 EXPORT_SYMBOL(sock_no_listen);
3444 
sock_no_shutdown(struct socket * sock,int how)3445 int sock_no_shutdown(struct socket *sock, int how)
3446 {
3447 	return -EOPNOTSUPP;
3448 }
3449 EXPORT_SYMBOL(sock_no_shutdown);
3450 
sock_no_sendmsg(struct socket * sock,struct msghdr * m,size_t len)3451 int sock_no_sendmsg(struct socket *sock, struct msghdr *m, size_t len)
3452 {
3453 	return -EOPNOTSUPP;
3454 }
3455 EXPORT_SYMBOL(sock_no_sendmsg);
3456 
sock_no_sendmsg_locked(struct sock * sk,struct msghdr * m,size_t len)3457 int sock_no_sendmsg_locked(struct sock *sk, struct msghdr *m, size_t len)
3458 {
3459 	return -EOPNOTSUPP;
3460 }
3461 EXPORT_SYMBOL(sock_no_sendmsg_locked);
3462 
sock_no_recvmsg(struct socket * sock,struct msghdr * m,size_t len,int flags)3463 int sock_no_recvmsg(struct socket *sock, struct msghdr *m, size_t len,
3464 		    int flags)
3465 {
3466 	return -EOPNOTSUPP;
3467 }
3468 EXPORT_SYMBOL(sock_no_recvmsg);
3469 
sock_no_mmap(struct file * file,struct socket * sock,struct vm_area_struct * vma)3470 int sock_no_mmap(struct file *file, struct socket *sock, struct vm_area_struct *vma)
3471 {
3472 	/* Mirror missing mmap method error code */
3473 	return -ENODEV;
3474 }
3475 EXPORT_SYMBOL(sock_no_mmap);
3476 
3477 /*
3478  * When a file is received (via SCM_RIGHTS, etc), we must bump the
3479  * various sock-based usage counts.
3480  */
__receive_sock(struct file * file)3481 void __receive_sock(struct file *file)
3482 {
3483 	struct socket *sock;
3484 
3485 	sock = sock_from_file(file);
3486 	if (sock) {
3487 		sock_update_netprioidx(&sock->sk->sk_cgrp_data);
3488 		sock_update_classid(&sock->sk->sk_cgrp_data);
3489 	}
3490 }
3491 
3492 /*
3493  *	Default Socket Callbacks
3494  */
3495 
sock_def_wakeup(struct sock * sk)3496 static void sock_def_wakeup(struct sock *sk)
3497 {
3498 	struct socket_wq *wq;
3499 
3500 	rcu_read_lock();
3501 	wq = rcu_dereference(sk->sk_wq);
3502 	if (skwq_has_sleeper(wq))
3503 		wake_up_interruptible_all(&wq->wait);
3504 	rcu_read_unlock();
3505 }
3506 
sock_def_error_report(struct sock * sk)3507 static void sock_def_error_report(struct sock *sk)
3508 {
3509 	struct socket_wq *wq;
3510 
3511 	rcu_read_lock();
3512 	wq = rcu_dereference(sk->sk_wq);
3513 	if (skwq_has_sleeper(wq))
3514 		wake_up_interruptible_poll(&wq->wait, EPOLLERR);
3515 	sk_wake_async_rcu(sk, SOCK_WAKE_IO, POLL_ERR);
3516 	rcu_read_unlock();
3517 }
3518 
sock_def_readable(struct sock * sk)3519 void sock_def_readable(struct sock *sk)
3520 {
3521 	struct socket_wq *wq;
3522 
3523 	trace_sk_data_ready(sk);
3524 
3525 	rcu_read_lock();
3526 	wq = rcu_dereference(sk->sk_wq);
3527 	if (skwq_has_sleeper(wq))
3528 		wake_up_interruptible_sync_poll(&wq->wait, EPOLLIN | EPOLLPRI |
3529 						EPOLLRDNORM | EPOLLRDBAND);
3530 	sk_wake_async_rcu(sk, SOCK_WAKE_WAITD, POLL_IN);
3531 	rcu_read_unlock();
3532 }
3533 
sock_def_write_space(struct sock * sk)3534 static void sock_def_write_space(struct sock *sk)
3535 {
3536 	struct socket_wq *wq;
3537 
3538 	rcu_read_lock();
3539 
3540 	/* Do not wake up a writer until he can make "significant"
3541 	 * progress.  --DaveM
3542 	 */
3543 	if (sock_writeable(sk)) {
3544 		wq = rcu_dereference(sk->sk_wq);
3545 		if (skwq_has_sleeper(wq))
3546 			wake_up_interruptible_sync_poll(&wq->wait, EPOLLOUT |
3547 						EPOLLWRNORM | EPOLLWRBAND);
3548 
3549 		/* Should agree with poll, otherwise some programs break */
3550 		sk_wake_async_rcu(sk, SOCK_WAKE_SPACE, POLL_OUT);
3551 	}
3552 
3553 	rcu_read_unlock();
3554 }
3555 
3556 /* An optimised version of sock_def_write_space(), should only be called
3557  * for SOCK_RCU_FREE sockets under RCU read section and after putting
3558  * ->sk_wmem_alloc.
3559  */
sock_def_write_space_wfree(struct sock * sk)3560 static void sock_def_write_space_wfree(struct sock *sk)
3561 {
3562 	/* Do not wake up a writer until he can make "significant"
3563 	 * progress.  --DaveM
3564 	 */
3565 	if (sock_writeable(sk)) {
3566 		struct socket_wq *wq = rcu_dereference(sk->sk_wq);
3567 
3568 		/* rely on refcount_sub from sock_wfree() */
3569 		smp_mb__after_atomic();
3570 		if (wq && waitqueue_active(&wq->wait))
3571 			wake_up_interruptible_sync_poll(&wq->wait, EPOLLOUT |
3572 						EPOLLWRNORM | EPOLLWRBAND);
3573 
3574 		/* Should agree with poll, otherwise some programs break */
3575 		sk_wake_async_rcu(sk, SOCK_WAKE_SPACE, POLL_OUT);
3576 	}
3577 }
3578 
sock_def_destruct(struct sock * sk)3579 static void sock_def_destruct(struct sock *sk)
3580 {
3581 }
3582 
sk_send_sigurg(struct sock * sk)3583 void sk_send_sigurg(struct sock *sk)
3584 {
3585 	if (sk->sk_socket && sk->sk_socket->file)
3586 		if (send_sigurg(sk->sk_socket->file))
3587 			sk_wake_async(sk, SOCK_WAKE_URG, POLL_PRI);
3588 }
3589 EXPORT_SYMBOL(sk_send_sigurg);
3590 
sk_reset_timer(struct sock * sk,struct timer_list * timer,unsigned long expires)3591 void sk_reset_timer(struct sock *sk, struct timer_list* timer,
3592 		    unsigned long expires)
3593 {
3594 	if (!mod_timer(timer, expires))
3595 		sock_hold(sk);
3596 }
3597 EXPORT_SYMBOL(sk_reset_timer);
3598 
sk_stop_timer(struct sock * sk,struct timer_list * timer)3599 void sk_stop_timer(struct sock *sk, struct timer_list* timer)
3600 {
3601 	if (del_timer(timer))
3602 		__sock_put(sk);
3603 }
3604 EXPORT_SYMBOL(sk_stop_timer);
3605 
sk_stop_timer_sync(struct sock * sk,struct timer_list * timer)3606 void sk_stop_timer_sync(struct sock *sk, struct timer_list *timer)
3607 {
3608 	if (del_timer_sync(timer))
3609 		__sock_put(sk);
3610 }
3611 EXPORT_SYMBOL(sk_stop_timer_sync);
3612 
sock_init_data_uid(struct socket * sock,struct sock * sk,kuid_t uid)3613 void sock_init_data_uid(struct socket *sock, struct sock *sk, kuid_t uid)
3614 {
3615 	sk_init_common(sk);
3616 	sk->sk_send_head	=	NULL;
3617 
3618 	timer_setup(&sk->sk_timer, NULL, 0);
3619 
3620 	sk->sk_allocation	=	GFP_KERNEL;
3621 	sk->sk_rcvbuf		=	READ_ONCE(sysctl_rmem_default);
3622 	sk->sk_sndbuf		=	READ_ONCE(sysctl_wmem_default);
3623 	sk->sk_state		=	TCP_CLOSE;
3624 	sk->sk_use_task_frag	=	true;
3625 	sk_set_socket(sk, sock);
3626 
3627 	sock_set_flag(sk, SOCK_ZAPPED);
3628 
3629 	if (sock) {
3630 		sk->sk_type	=	sock->type;
3631 		RCU_INIT_POINTER(sk->sk_wq, &sock->wq);
3632 		sock->sk	=	sk;
3633 	} else {
3634 		RCU_INIT_POINTER(sk->sk_wq, NULL);
3635 	}
3636 	sk->sk_uid	=	uid;
3637 
3638 	sk->sk_state_change	=	sock_def_wakeup;
3639 	sk->sk_data_ready	=	sock_def_readable;
3640 	sk->sk_write_space	=	sock_def_write_space;
3641 	sk->sk_error_report	=	sock_def_error_report;
3642 	sk->sk_destruct		=	sock_def_destruct;
3643 
3644 	sk->sk_frag.page	=	NULL;
3645 	sk->sk_frag.offset	=	0;
3646 	sk->sk_peek_off		=	-1;
3647 
3648 	sk->sk_peer_pid 	=	NULL;
3649 	sk->sk_peer_cred	=	NULL;
3650 	spin_lock_init(&sk->sk_peer_lock);
3651 
3652 	sk->sk_write_pending	=	0;
3653 	sk->sk_rcvlowat		=	1;
3654 	sk->sk_rcvtimeo		=	MAX_SCHEDULE_TIMEOUT;
3655 	sk->sk_sndtimeo		=	MAX_SCHEDULE_TIMEOUT;
3656 
3657 	sk->sk_stamp = SK_DEFAULT_STAMP;
3658 #if BITS_PER_LONG==32
3659 	seqlock_init(&sk->sk_stamp_seq);
3660 #endif
3661 	atomic_set(&sk->sk_zckey, 0);
3662 
3663 #ifdef CONFIG_NET_RX_BUSY_POLL
3664 	sk->sk_napi_id		=	0;
3665 	sk->sk_ll_usec		=	READ_ONCE(sysctl_net_busy_read);
3666 #endif
3667 
3668 	sk->sk_max_pacing_rate = ~0UL;
3669 	sk->sk_pacing_rate = ~0UL;
3670 	WRITE_ONCE(sk->sk_pacing_shift, 10);
3671 	sk->sk_incoming_cpu = -1;
3672 
3673 	sk_rx_queue_clear(sk);
3674 	/*
3675 	 * Before updating sk_refcnt, we must commit prior changes to memory
3676 	 * (Documentation/RCU/rculist_nulls.rst for details)
3677 	 */
3678 	smp_wmb();
3679 	refcount_set(&sk->sk_refcnt, 1);
3680 	atomic_set(&sk->sk_drops, 0);
3681 }
3682 EXPORT_SYMBOL(sock_init_data_uid);
3683 
sock_init_data(struct socket * sock,struct sock * sk)3684 void sock_init_data(struct socket *sock, struct sock *sk)
3685 {
3686 	kuid_t uid = sock ?
3687 		SOCK_INODE(sock)->i_uid :
3688 		make_kuid(sock_net(sk)->user_ns, 0);
3689 
3690 	sock_init_data_uid(sock, sk, uid);
3691 }
3692 EXPORT_SYMBOL(sock_init_data);
3693 
lock_sock_nested(struct sock * sk,int subclass)3694 void lock_sock_nested(struct sock *sk, int subclass)
3695 {
3696 	/* The sk_lock has mutex_lock() semantics here. */
3697 	mutex_acquire(&sk->sk_lock.dep_map, subclass, 0, _RET_IP_);
3698 
3699 	might_sleep();
3700 	spin_lock_bh(&sk->sk_lock.slock);
3701 	if (sock_owned_by_user_nocheck(sk))
3702 		__lock_sock(sk);
3703 	sk->sk_lock.owned = 1;
3704 	spin_unlock_bh(&sk->sk_lock.slock);
3705 }
3706 EXPORT_SYMBOL(lock_sock_nested);
3707 
release_sock(struct sock * sk)3708 void release_sock(struct sock *sk)
3709 {
3710 	spin_lock_bh(&sk->sk_lock.slock);
3711 	if (sk->sk_backlog.tail)
3712 		__release_sock(sk);
3713 
3714 	if (sk->sk_prot->release_cb)
3715 		INDIRECT_CALL_INET_1(sk->sk_prot->release_cb,
3716 				     tcp_release_cb, sk);
3717 
3718 	sock_release_ownership(sk);
3719 	if (waitqueue_active(&sk->sk_lock.wq))
3720 		wake_up(&sk->sk_lock.wq);
3721 	spin_unlock_bh(&sk->sk_lock.slock);
3722 }
3723 EXPORT_SYMBOL(release_sock);
3724 
__lock_sock_fast(struct sock * sk)3725 bool __lock_sock_fast(struct sock *sk) __acquires(&sk->sk_lock.slock)
3726 {
3727 	might_sleep();
3728 	spin_lock_bh(&sk->sk_lock.slock);
3729 
3730 	if (!sock_owned_by_user_nocheck(sk)) {
3731 		/*
3732 		 * Fast path return with bottom halves disabled and
3733 		 * sock::sk_lock.slock held.
3734 		 *
3735 		 * The 'mutex' is not contended and holding
3736 		 * sock::sk_lock.slock prevents all other lockers to
3737 		 * proceed so the corresponding unlock_sock_fast() can
3738 		 * avoid the slow path of release_sock() completely and
3739 		 * just release slock.
3740 		 *
3741 		 * From a semantical POV this is equivalent to 'acquiring'
3742 		 * the 'mutex', hence the corresponding lockdep
3743 		 * mutex_release() has to happen in the fast path of
3744 		 * unlock_sock_fast().
3745 		 */
3746 		return false;
3747 	}
3748 
3749 	__lock_sock(sk);
3750 	sk->sk_lock.owned = 1;
3751 	__acquire(&sk->sk_lock.slock);
3752 	spin_unlock_bh(&sk->sk_lock.slock);
3753 	return true;
3754 }
3755 EXPORT_SYMBOL(__lock_sock_fast);
3756 
sock_gettstamp(struct socket * sock,void __user * userstamp,bool timeval,bool time32)3757 int sock_gettstamp(struct socket *sock, void __user *userstamp,
3758 		   bool timeval, bool time32)
3759 {
3760 	struct sock *sk = sock->sk;
3761 	struct timespec64 ts;
3762 
3763 	sock_enable_timestamp(sk, SOCK_TIMESTAMP);
3764 	ts = ktime_to_timespec64(sock_read_timestamp(sk));
3765 	if (ts.tv_sec == -1)
3766 		return -ENOENT;
3767 	if (ts.tv_sec == 0) {
3768 		ktime_t kt = ktime_get_real();
3769 		sock_write_timestamp(sk, kt);
3770 		ts = ktime_to_timespec64(kt);
3771 	}
3772 
3773 	if (timeval)
3774 		ts.tv_nsec /= 1000;
3775 
3776 #ifdef CONFIG_COMPAT_32BIT_TIME
3777 	if (time32)
3778 		return put_old_timespec32(&ts, userstamp);
3779 #endif
3780 #ifdef CONFIG_SPARC64
3781 	/* beware of padding in sparc64 timeval */
3782 	if (timeval && !in_compat_syscall()) {
3783 		struct __kernel_old_timeval __user tv = {
3784 			.tv_sec = ts.tv_sec,
3785 			.tv_usec = ts.tv_nsec,
3786 		};
3787 		if (copy_to_user(userstamp, &tv, sizeof(tv)))
3788 			return -EFAULT;
3789 		return 0;
3790 	}
3791 #endif
3792 	return put_timespec64(&ts, userstamp);
3793 }
3794 EXPORT_SYMBOL(sock_gettstamp);
3795 
sock_enable_timestamp(struct sock * sk,enum sock_flags flag)3796 void sock_enable_timestamp(struct sock *sk, enum sock_flags flag)
3797 {
3798 	if (!sock_flag(sk, flag)) {
3799 		unsigned long previous_flags = sk->sk_flags;
3800 
3801 		sock_set_flag(sk, flag);
3802 		/*
3803 		 * we just set one of the two flags which require net
3804 		 * time stamping, but time stamping might have been on
3805 		 * already because of the other one
3806 		 */
3807 		if (sock_needs_netstamp(sk) &&
3808 		    !(previous_flags & SK_FLAGS_TIMESTAMP))
3809 			net_enable_timestamp();
3810 	}
3811 }
3812 
sock_recv_errqueue(struct sock * sk,struct msghdr * msg,int len,int level,int type)3813 int sock_recv_errqueue(struct sock *sk, struct msghdr *msg, int len,
3814 		       int level, int type)
3815 {
3816 	struct sock_exterr_skb *serr;
3817 	struct sk_buff *skb;
3818 	int copied, err;
3819 
3820 	err = -EAGAIN;
3821 	skb = sock_dequeue_err_skb(sk);
3822 	if (skb == NULL)
3823 		goto out;
3824 
3825 	copied = skb->len;
3826 	if (copied > len) {
3827 		msg->msg_flags |= MSG_TRUNC;
3828 		copied = len;
3829 	}
3830 	err = skb_copy_datagram_msg(skb, 0, msg, copied);
3831 	if (err)
3832 		goto out_free_skb;
3833 
3834 	sock_recv_timestamp(msg, sk, skb);
3835 
3836 	serr = SKB_EXT_ERR(skb);
3837 	put_cmsg(msg, level, type, sizeof(serr->ee), &serr->ee);
3838 
3839 	msg->msg_flags |= MSG_ERRQUEUE;
3840 	err = copied;
3841 
3842 out_free_skb:
3843 	kfree_skb(skb);
3844 out:
3845 	return err;
3846 }
3847 EXPORT_SYMBOL(sock_recv_errqueue);
3848 
3849 /*
3850  *	Get a socket option on an socket.
3851  *
3852  *	FIX: POSIX 1003.1g is very ambiguous here. It states that
3853  *	asynchronous errors should be reported by getsockopt. We assume
3854  *	this means if you specify SO_ERROR (otherwise what is the point of it).
3855  */
sock_common_getsockopt(struct socket * sock,int level,int optname,char __user * optval,int __user * optlen)3856 int sock_common_getsockopt(struct socket *sock, int level, int optname,
3857 			   char __user *optval, int __user *optlen)
3858 {
3859 	struct sock *sk = sock->sk;
3860 
3861 	/* IPV6_ADDRFORM can change sk->sk_prot under us. */
3862 	return READ_ONCE(sk->sk_prot)->getsockopt(sk, level, optname, optval, optlen);
3863 }
3864 EXPORT_SYMBOL(sock_common_getsockopt);
3865 
sock_common_recvmsg(struct socket * sock,struct msghdr * msg,size_t size,int flags)3866 int sock_common_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
3867 			int flags)
3868 {
3869 	struct sock *sk = sock->sk;
3870 	int addr_len = 0;
3871 	int err;
3872 
3873 	err = sk->sk_prot->recvmsg(sk, msg, size, flags, &addr_len);
3874 	if (err >= 0)
3875 		msg->msg_namelen = addr_len;
3876 	return err;
3877 }
3878 EXPORT_SYMBOL(sock_common_recvmsg);
3879 
3880 /*
3881  *	Set socket options on an inet socket.
3882  */
sock_common_setsockopt(struct socket * sock,int level,int optname,sockptr_t optval,unsigned int optlen)3883 int sock_common_setsockopt(struct socket *sock, int level, int optname,
3884 			   sockptr_t optval, unsigned int optlen)
3885 {
3886 	struct sock *sk = sock->sk;
3887 
3888 	/* IPV6_ADDRFORM can change sk->sk_prot under us. */
3889 	return READ_ONCE(sk->sk_prot)->setsockopt(sk, level, optname, optval, optlen);
3890 }
3891 EXPORT_SYMBOL(sock_common_setsockopt);
3892 
sk_common_release(struct sock * sk)3893 void sk_common_release(struct sock *sk)
3894 {
3895 	if (sk->sk_prot->destroy)
3896 		sk->sk_prot->destroy(sk);
3897 
3898 	/*
3899 	 * Observation: when sk_common_release is called, processes have
3900 	 * no access to socket. But net still has.
3901 	 * Step one, detach it from networking:
3902 	 *
3903 	 * A. Remove from hash tables.
3904 	 */
3905 
3906 	sk->sk_prot->unhash(sk);
3907 
3908 	/*
3909 	 * In this point socket cannot receive new packets, but it is possible
3910 	 * that some packets are in flight because some CPU runs receiver and
3911 	 * did hash table lookup before we unhashed socket. They will achieve
3912 	 * receive queue and will be purged by socket destructor.
3913 	 *
3914 	 * Also we still have packets pending on receive queue and probably,
3915 	 * our own packets waiting in device queues. sock_destroy will drain
3916 	 * receive queue, but transmitted packets will delay socket destruction
3917 	 * until the last reference will be released.
3918 	 */
3919 
3920 	sock_orphan(sk);
3921 
3922 	xfrm_sk_free_policy(sk);
3923 
3924 	sock_put(sk);
3925 }
3926 EXPORT_SYMBOL(sk_common_release);
3927 
sk_get_meminfo(const struct sock * sk,u32 * mem)3928 void sk_get_meminfo(const struct sock *sk, u32 *mem)
3929 {
3930 	memset(mem, 0, sizeof(*mem) * SK_MEMINFO_VARS);
3931 
3932 	mem[SK_MEMINFO_RMEM_ALLOC] = sk_rmem_alloc_get(sk);
3933 	mem[SK_MEMINFO_RCVBUF] = READ_ONCE(sk->sk_rcvbuf);
3934 	mem[SK_MEMINFO_WMEM_ALLOC] = sk_wmem_alloc_get(sk);
3935 	mem[SK_MEMINFO_SNDBUF] = READ_ONCE(sk->sk_sndbuf);
3936 	mem[SK_MEMINFO_FWD_ALLOC] = READ_ONCE(sk->sk_forward_alloc);
3937 	mem[SK_MEMINFO_WMEM_QUEUED] = READ_ONCE(sk->sk_wmem_queued);
3938 	mem[SK_MEMINFO_OPTMEM] = atomic_read(&sk->sk_omem_alloc);
3939 	mem[SK_MEMINFO_BACKLOG] = READ_ONCE(sk->sk_backlog.len);
3940 	mem[SK_MEMINFO_DROPS] = atomic_read(&sk->sk_drops);
3941 }
3942 
3943 #ifdef CONFIG_PROC_FS
3944 static DECLARE_BITMAP(proto_inuse_idx, PROTO_INUSE_NR);
3945 
sock_prot_inuse_get(struct net * net,struct proto * prot)3946 int sock_prot_inuse_get(struct net *net, struct proto *prot)
3947 {
3948 	int cpu, idx = prot->inuse_idx;
3949 	int res = 0;
3950 
3951 	for_each_possible_cpu(cpu)
3952 		res += per_cpu_ptr(net->core.prot_inuse, cpu)->val[idx];
3953 
3954 	return res >= 0 ? res : 0;
3955 }
3956 EXPORT_SYMBOL_GPL(sock_prot_inuse_get);
3957 
sock_inuse_get(struct net * net)3958 int sock_inuse_get(struct net *net)
3959 {
3960 	int cpu, res = 0;
3961 
3962 	for_each_possible_cpu(cpu)
3963 		res += per_cpu_ptr(net->core.prot_inuse, cpu)->all;
3964 
3965 	return res;
3966 }
3967 
3968 EXPORT_SYMBOL_GPL(sock_inuse_get);
3969 
sock_inuse_init_net(struct net * net)3970 static int __net_init sock_inuse_init_net(struct net *net)
3971 {
3972 	net->core.prot_inuse = alloc_percpu(struct prot_inuse);
3973 	if (net->core.prot_inuse == NULL)
3974 		return -ENOMEM;
3975 	return 0;
3976 }
3977 
sock_inuse_exit_net(struct net * net)3978 static void __net_exit sock_inuse_exit_net(struct net *net)
3979 {
3980 	free_percpu(net->core.prot_inuse);
3981 }
3982 
3983 static struct pernet_operations net_inuse_ops = {
3984 	.init = sock_inuse_init_net,
3985 	.exit = sock_inuse_exit_net,
3986 };
3987 
net_inuse_init(void)3988 static __init int net_inuse_init(void)
3989 {
3990 	if (register_pernet_subsys(&net_inuse_ops))
3991 		panic("Cannot initialize net inuse counters");
3992 
3993 	return 0;
3994 }
3995 
3996 core_initcall(net_inuse_init);
3997 
assign_proto_idx(struct proto * prot)3998 static int assign_proto_idx(struct proto *prot)
3999 {
4000 	prot->inuse_idx = find_first_zero_bit(proto_inuse_idx, PROTO_INUSE_NR);
4001 
4002 	if (unlikely(prot->inuse_idx == PROTO_INUSE_NR - 1)) {
4003 		pr_err("PROTO_INUSE_NR exhausted\n");
4004 		return -ENOSPC;
4005 	}
4006 
4007 	set_bit(prot->inuse_idx, proto_inuse_idx);
4008 	return 0;
4009 }
4010 
release_proto_idx(struct proto * prot)4011 static void release_proto_idx(struct proto *prot)
4012 {
4013 	if (prot->inuse_idx != PROTO_INUSE_NR - 1)
4014 		clear_bit(prot->inuse_idx, proto_inuse_idx);
4015 }
4016 #else
assign_proto_idx(struct proto * prot)4017 static inline int assign_proto_idx(struct proto *prot)
4018 {
4019 	return 0;
4020 }
4021 
release_proto_idx(struct proto * prot)4022 static inline void release_proto_idx(struct proto *prot)
4023 {
4024 }
4025 
4026 #endif
4027 
tw_prot_cleanup(struct timewait_sock_ops * twsk_prot)4028 static void tw_prot_cleanup(struct timewait_sock_ops *twsk_prot)
4029 {
4030 	if (!twsk_prot)
4031 		return;
4032 	kfree(twsk_prot->twsk_slab_name);
4033 	twsk_prot->twsk_slab_name = NULL;
4034 	kmem_cache_destroy(twsk_prot->twsk_slab);
4035 	twsk_prot->twsk_slab = NULL;
4036 }
4037 
tw_prot_init(const struct proto * prot)4038 static int tw_prot_init(const struct proto *prot)
4039 {
4040 	struct timewait_sock_ops *twsk_prot = prot->twsk_prot;
4041 
4042 	if (!twsk_prot)
4043 		return 0;
4044 
4045 	twsk_prot->twsk_slab_name = kasprintf(GFP_KERNEL, "tw_sock_%s",
4046 					      prot->name);
4047 	if (!twsk_prot->twsk_slab_name)
4048 		return -ENOMEM;
4049 
4050 	twsk_prot->twsk_slab =
4051 		kmem_cache_create(twsk_prot->twsk_slab_name,
4052 				  twsk_prot->twsk_obj_size, 0,
4053 				  SLAB_ACCOUNT | prot->slab_flags,
4054 				  NULL);
4055 	if (!twsk_prot->twsk_slab) {
4056 		pr_crit("%s: Can't create timewait sock SLAB cache!\n",
4057 			prot->name);
4058 		return -ENOMEM;
4059 	}
4060 
4061 	return 0;
4062 }
4063 
req_prot_cleanup(struct request_sock_ops * rsk_prot)4064 static void req_prot_cleanup(struct request_sock_ops *rsk_prot)
4065 {
4066 	if (!rsk_prot)
4067 		return;
4068 	kfree(rsk_prot->slab_name);
4069 	rsk_prot->slab_name = NULL;
4070 	kmem_cache_destroy(rsk_prot->slab);
4071 	rsk_prot->slab = NULL;
4072 }
4073 
req_prot_init(const struct proto * prot)4074 static int req_prot_init(const struct proto *prot)
4075 {
4076 	struct request_sock_ops *rsk_prot = prot->rsk_prot;
4077 
4078 	if (!rsk_prot)
4079 		return 0;
4080 
4081 	rsk_prot->slab_name = kasprintf(GFP_KERNEL, "request_sock_%s",
4082 					prot->name);
4083 	if (!rsk_prot->slab_name)
4084 		return -ENOMEM;
4085 
4086 	rsk_prot->slab = kmem_cache_create(rsk_prot->slab_name,
4087 					   rsk_prot->obj_size, 0,
4088 					   SLAB_ACCOUNT | prot->slab_flags,
4089 					   NULL);
4090 
4091 	if (!rsk_prot->slab) {
4092 		pr_crit("%s: Can't create request sock SLAB cache!\n",
4093 			prot->name);
4094 		return -ENOMEM;
4095 	}
4096 	return 0;
4097 }
4098 
proto_register(struct proto * prot,int alloc_slab)4099 int proto_register(struct proto *prot, int alloc_slab)
4100 {
4101 	int ret = -ENOBUFS;
4102 
4103 	if (prot->memory_allocated && !prot->sysctl_mem) {
4104 		pr_err("%s: missing sysctl_mem\n", prot->name);
4105 		return -EINVAL;
4106 	}
4107 	if (prot->memory_allocated && !prot->per_cpu_fw_alloc) {
4108 		pr_err("%s: missing per_cpu_fw_alloc\n", prot->name);
4109 		return -EINVAL;
4110 	}
4111 	if (alloc_slab) {
4112 		prot->slab = kmem_cache_create_usercopy(prot->name,
4113 					prot->obj_size, 0,
4114 					SLAB_HWCACHE_ALIGN | SLAB_ACCOUNT |
4115 					prot->slab_flags,
4116 					prot->useroffset, prot->usersize,
4117 					NULL);
4118 
4119 		if (prot->slab == NULL) {
4120 			pr_crit("%s: Can't create sock SLAB cache!\n",
4121 				prot->name);
4122 			goto out;
4123 		}
4124 
4125 		if (req_prot_init(prot))
4126 			goto out_free_request_sock_slab;
4127 
4128 		if (tw_prot_init(prot))
4129 			goto out_free_timewait_sock_slab;
4130 	}
4131 
4132 	mutex_lock(&proto_list_mutex);
4133 	ret = assign_proto_idx(prot);
4134 	if (ret) {
4135 		mutex_unlock(&proto_list_mutex);
4136 		goto out_free_timewait_sock_slab;
4137 	}
4138 	list_add(&prot->node, &proto_list);
4139 	mutex_unlock(&proto_list_mutex);
4140 	return ret;
4141 
4142 out_free_timewait_sock_slab:
4143 	if (alloc_slab)
4144 		tw_prot_cleanup(prot->twsk_prot);
4145 out_free_request_sock_slab:
4146 	if (alloc_slab) {
4147 		req_prot_cleanup(prot->rsk_prot);
4148 
4149 		kmem_cache_destroy(prot->slab);
4150 		prot->slab = NULL;
4151 	}
4152 out:
4153 	return ret;
4154 }
4155 EXPORT_SYMBOL(proto_register);
4156 
proto_unregister(struct proto * prot)4157 void proto_unregister(struct proto *prot)
4158 {
4159 	mutex_lock(&proto_list_mutex);
4160 	release_proto_idx(prot);
4161 	list_del(&prot->node);
4162 	mutex_unlock(&proto_list_mutex);
4163 
4164 	kmem_cache_destroy(prot->slab);
4165 	prot->slab = NULL;
4166 
4167 	req_prot_cleanup(prot->rsk_prot);
4168 	tw_prot_cleanup(prot->twsk_prot);
4169 }
4170 EXPORT_SYMBOL(proto_unregister);
4171 
sock_load_diag_module(int family,int protocol)4172 int sock_load_diag_module(int family, int protocol)
4173 {
4174 	if (!protocol) {
4175 		if (!sock_is_registered(family))
4176 			return -ENOENT;
4177 
4178 		return request_module("net-pf-%d-proto-%d-type-%d", PF_NETLINK,
4179 				      NETLINK_SOCK_DIAG, family);
4180 	}
4181 
4182 #ifdef CONFIG_INET
4183 	if (family == AF_INET &&
4184 	    protocol != IPPROTO_RAW &&
4185 	    protocol < MAX_INET_PROTOS &&
4186 	    !rcu_access_pointer(inet_protos[protocol]))
4187 		return -ENOENT;
4188 #endif
4189 
4190 	return request_module("net-pf-%d-proto-%d-type-%d-%d", PF_NETLINK,
4191 			      NETLINK_SOCK_DIAG, family, protocol);
4192 }
4193 EXPORT_SYMBOL(sock_load_diag_module);
4194 
4195 #ifdef CONFIG_PROC_FS
proto_seq_start(struct seq_file * seq,loff_t * pos)4196 static void *proto_seq_start(struct seq_file *seq, loff_t *pos)
4197 	__acquires(proto_list_mutex)
4198 {
4199 	mutex_lock(&proto_list_mutex);
4200 	return seq_list_start_head(&proto_list, *pos);
4201 }
4202 
proto_seq_next(struct seq_file * seq,void * v,loff_t * pos)4203 static void *proto_seq_next(struct seq_file *seq, void *v, loff_t *pos)
4204 {
4205 	return seq_list_next(v, &proto_list, pos);
4206 }
4207 
proto_seq_stop(struct seq_file * seq,void * v)4208 static void proto_seq_stop(struct seq_file *seq, void *v)
4209 	__releases(proto_list_mutex)
4210 {
4211 	mutex_unlock(&proto_list_mutex);
4212 }
4213 
proto_method_implemented(const void * method)4214 static char proto_method_implemented(const void *method)
4215 {
4216 	return method == NULL ? 'n' : 'y';
4217 }
sock_prot_memory_allocated(struct proto * proto)4218 static long sock_prot_memory_allocated(struct proto *proto)
4219 {
4220 	return proto->memory_allocated != NULL ? proto_memory_allocated(proto) : -1L;
4221 }
4222 
sock_prot_memory_pressure(struct proto * proto)4223 static const char *sock_prot_memory_pressure(struct proto *proto)
4224 {
4225 	return proto->memory_pressure != NULL ?
4226 	proto_memory_pressure(proto) ? "yes" : "no" : "NI";
4227 }
4228 
proto_seq_printf(struct seq_file * seq,struct proto * proto)4229 static void proto_seq_printf(struct seq_file *seq, struct proto *proto)
4230 {
4231 
4232 	seq_printf(seq, "%-9s %4u %6d  %6ld   %-3s %6u   %-3s  %-10s "
4233 			"%2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c\n",
4234 		   proto->name,
4235 		   proto->obj_size,
4236 		   sock_prot_inuse_get(seq_file_net(seq), proto),
4237 		   sock_prot_memory_allocated(proto),
4238 		   sock_prot_memory_pressure(proto),
4239 		   proto->max_header,
4240 		   proto->slab == NULL ? "no" : "yes",
4241 		   module_name(proto->owner),
4242 		   proto_method_implemented(proto->close),
4243 		   proto_method_implemented(proto->connect),
4244 		   proto_method_implemented(proto->disconnect),
4245 		   proto_method_implemented(proto->accept),
4246 		   proto_method_implemented(proto->ioctl),
4247 		   proto_method_implemented(proto->init),
4248 		   proto_method_implemented(proto->destroy),
4249 		   proto_method_implemented(proto->shutdown),
4250 		   proto_method_implemented(proto->setsockopt),
4251 		   proto_method_implemented(proto->getsockopt),
4252 		   proto_method_implemented(proto->sendmsg),
4253 		   proto_method_implemented(proto->recvmsg),
4254 		   proto_method_implemented(proto->bind),
4255 		   proto_method_implemented(proto->backlog_rcv),
4256 		   proto_method_implemented(proto->hash),
4257 		   proto_method_implemented(proto->unhash),
4258 		   proto_method_implemented(proto->get_port),
4259 		   proto_method_implemented(proto->enter_memory_pressure));
4260 }
4261 
proto_seq_show(struct seq_file * seq,void * v)4262 static int proto_seq_show(struct seq_file *seq, void *v)
4263 {
4264 	if (v == &proto_list)
4265 		seq_printf(seq, "%-9s %-4s %-8s %-6s %-5s %-7s %-4s %-10s %s",
4266 			   "protocol",
4267 			   "size",
4268 			   "sockets",
4269 			   "memory",
4270 			   "press",
4271 			   "maxhdr",
4272 			   "slab",
4273 			   "module",
4274 			   "cl co di ac io in de sh ss gs se re bi br ha uh gp em\n");
4275 	else
4276 		proto_seq_printf(seq, list_entry(v, struct proto, node));
4277 	return 0;
4278 }
4279 
4280 static const struct seq_operations proto_seq_ops = {
4281 	.start  = proto_seq_start,
4282 	.next   = proto_seq_next,
4283 	.stop   = proto_seq_stop,
4284 	.show   = proto_seq_show,
4285 };
4286 
proto_init_net(struct net * net)4287 static __net_init int proto_init_net(struct net *net)
4288 {
4289 	if (!proc_create_net("protocols", 0444, net->proc_net, &proto_seq_ops,
4290 			sizeof(struct seq_net_private)))
4291 		return -ENOMEM;
4292 
4293 	return 0;
4294 }
4295 
proto_exit_net(struct net * net)4296 static __net_exit void proto_exit_net(struct net *net)
4297 {
4298 	remove_proc_entry("protocols", net->proc_net);
4299 }
4300 
4301 
4302 static __net_initdata struct pernet_operations proto_net_ops = {
4303 	.init = proto_init_net,
4304 	.exit = proto_exit_net,
4305 };
4306 
proto_init(void)4307 static int __init proto_init(void)
4308 {
4309 	return register_pernet_subsys(&proto_net_ops);
4310 }
4311 
4312 subsys_initcall(proto_init);
4313 
4314 #endif /* PROC_FS */
4315 
4316 #ifdef CONFIG_NET_RX_BUSY_POLL
sk_busy_loop_end(void * p,unsigned long start_time)4317 bool sk_busy_loop_end(void *p, unsigned long start_time)
4318 {
4319 	struct sock *sk = p;
4320 
4321 	if (!skb_queue_empty_lockless(&sk->sk_receive_queue))
4322 		return true;
4323 
4324 	if (sk_is_udp(sk) &&
4325 	    !skb_queue_empty_lockless(&udp_sk(sk)->reader_queue))
4326 		return true;
4327 
4328 	return sk_busy_loop_timeout(sk, start_time);
4329 }
4330 EXPORT_SYMBOL(sk_busy_loop_end);
4331 #endif /* CONFIG_NET_RX_BUSY_POLL */
4332 
sock_bind_add(struct sock * sk,struct sockaddr * addr,int addr_len)4333 int sock_bind_add(struct sock *sk, struct sockaddr *addr, int addr_len)
4334 {
4335 	if (!sk->sk_prot->bind_add)
4336 		return -EOPNOTSUPP;
4337 	return sk->sk_prot->bind_add(sk, addr, addr_len);
4338 }
4339 EXPORT_SYMBOL(sock_bind_add);
4340 
4341 /* 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)4342 int sock_ioctl_inout(struct sock *sk, unsigned int cmd,
4343 		     void __user *arg, void *karg, size_t size)
4344 {
4345 	int ret;
4346 
4347 	if (copy_from_user(karg, arg, size))
4348 		return -EFAULT;
4349 
4350 	ret = READ_ONCE(sk->sk_prot)->ioctl(sk, cmd, karg);
4351 	if (ret)
4352 		return ret;
4353 
4354 	if (copy_to_user(arg, karg, size))
4355 		return -EFAULT;
4356 
4357 	return 0;
4358 }
4359 EXPORT_SYMBOL(sock_ioctl_inout);
4360 
4361 /* This is the most common ioctl prep function, where the result (4 bytes) is
4362  * copied back to userspace if the ioctl() returns successfully. No input is
4363  * copied from userspace as input argument.
4364  */
sock_ioctl_out(struct sock * sk,unsigned int cmd,void __user * arg)4365 static int sock_ioctl_out(struct sock *sk, unsigned int cmd, void __user *arg)
4366 {
4367 	int ret, karg = 0;
4368 
4369 	ret = READ_ONCE(sk->sk_prot)->ioctl(sk, cmd, &karg);
4370 	if (ret)
4371 		return ret;
4372 
4373 	return put_user(karg, (int __user *)arg);
4374 }
4375 
4376 /* A wrapper around sock ioctls, which copies the data from userspace
4377  * (depending on the protocol/ioctl), and copies back the result to userspace.
4378  * The main motivation for this function is to pass kernel memory to the
4379  * protocol ioctl callbacks, instead of userspace memory.
4380  */
sk_ioctl(struct sock * sk,unsigned int cmd,void __user * arg)4381 int sk_ioctl(struct sock *sk, unsigned int cmd, void __user *arg)
4382 {
4383 	int rc = 1;
4384 
4385 	if (sk->sk_type == SOCK_RAW && sk->sk_family == AF_INET)
4386 		rc = ipmr_sk_ioctl(sk, cmd, arg);
4387 	else if (sk->sk_type == SOCK_RAW && sk->sk_family == AF_INET6)
4388 		rc = ip6mr_sk_ioctl(sk, cmd, arg);
4389 	else if (sk_is_phonet(sk))
4390 		rc = phonet_sk_ioctl(sk, cmd, arg);
4391 
4392 	/* If ioctl was processed, returns its value */
4393 	if (rc <= 0)
4394 		return rc;
4395 
4396 	/* Otherwise call the default handler */
4397 	return sock_ioctl_out(sk, cmd, arg);
4398 }
4399 EXPORT_SYMBOL(sk_ioctl);
4400 
sock_struct_check(void)4401 static int __init sock_struct_check(void)
4402 {
4403 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_rx, sk_drops);
4404 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_rx, sk_peek_off);
4405 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_rx, sk_error_queue);
4406 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_rx, sk_receive_queue);
4407 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_rx, sk_backlog);
4408 
4409 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_rx, sk_rx_dst);
4410 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_rx, sk_rx_dst_ifindex);
4411 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_rx, sk_rx_dst_cookie);
4412 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_rx, sk_rcvbuf);
4413 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_rx, sk_filter);
4414 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_rx, sk_wq);
4415 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_rx, sk_data_ready);
4416 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_rx, sk_rcvtimeo);
4417 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_rx, sk_rcvlowat);
4418 
4419 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_rxtx, sk_err);
4420 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_rxtx, sk_socket);
4421 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_rxtx, sk_memcg);
4422 
4423 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_rxtx, sk_lock);
4424 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_rxtx, sk_reserved_mem);
4425 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_rxtx, sk_forward_alloc);
4426 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_rxtx, sk_tsflags);
4427 
4428 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_omem_alloc);
4429 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_omem_alloc);
4430 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_sndbuf);
4431 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_wmem_queued);
4432 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_wmem_alloc);
4433 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_tsq_flags);
4434 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_send_head);
4435 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_write_queue);
4436 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_write_pending);
4437 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_dst_pending_confirm);
4438 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_pacing_status);
4439 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_frag);
4440 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_timer);
4441 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_pacing_rate);
4442 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_zckey);
4443 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_tskey);
4444 
4445 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_max_pacing_rate);
4446 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_sndtimeo);
4447 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_priority);
4448 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_mark);
4449 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_dst_cache);
4450 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_route_caps);
4451 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_gso_type);
4452 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_gso_max_size);
4453 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_allocation);
4454 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_txhash);
4455 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_gso_max_segs);
4456 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_pacing_shift);
4457 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_use_task_frag);
4458 	return 0;
4459 }
4460 
4461 core_initcall(sock_struct_check);
4462