xref: /linux/net/core/sock.c (revision 8be4d31cb8aaeea27bde4b7ddb26e28a89062ebf)
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 <uapi/linux/pidfd.h>
152 
153 #include "dev.h"
154 
155 static DEFINE_MUTEX(proto_list_mutex);
156 static LIST_HEAD(proto_list);
157 
158 static void sock_def_write_space_wfree(struct sock *sk);
159 static void sock_def_write_space(struct sock *sk);
160 
161 /**
162  * sk_ns_capable - General socket capability test
163  * @sk: Socket to use a capability on or through
164  * @user_ns: The user namespace of the capability to use
165  * @cap: The capability to use
166  *
167  * Test to see if the opener of the socket had when the socket was
168  * created and the current process has the capability @cap in the user
169  * namespace @user_ns.
170  */
sk_ns_capable(const struct sock * sk,struct user_namespace * user_ns,int cap)171 bool sk_ns_capable(const struct sock *sk,
172 		   struct user_namespace *user_ns, int cap)
173 {
174 	return file_ns_capable(sk->sk_socket->file, user_ns, cap) &&
175 		ns_capable(user_ns, cap);
176 }
177 EXPORT_SYMBOL(sk_ns_capable);
178 
179 /**
180  * sk_capable - Socket global capability test
181  * @sk: Socket to use a capability on or through
182  * @cap: The global capability to use
183  *
184  * Test to see if the opener of the socket had when the socket was
185  * created and the current process has the capability @cap in all user
186  * namespaces.
187  */
sk_capable(const struct sock * sk,int cap)188 bool sk_capable(const struct sock *sk, int cap)
189 {
190 	return sk_ns_capable(sk, &init_user_ns, cap);
191 }
192 EXPORT_SYMBOL(sk_capable);
193 
194 /**
195  * sk_net_capable - Network namespace socket capability test
196  * @sk: Socket to use a capability on or through
197  * @cap: The capability to use
198  *
199  * Test to see if the opener of the socket had when the socket was created
200  * and the current process has the capability @cap over the network namespace
201  * the socket is a member of.
202  */
sk_net_capable(const struct sock * sk,int cap)203 bool sk_net_capable(const struct sock *sk, int cap)
204 {
205 	return sk_ns_capable(sk, sock_net(sk)->user_ns, cap);
206 }
207 EXPORT_SYMBOL(sk_net_capable);
208 
209 /*
210  * Each address family might have different locking rules, so we have
211  * one slock key per address family and separate keys for internal and
212  * userspace sockets.
213  */
214 static struct lock_class_key af_family_keys[AF_MAX];
215 static struct lock_class_key af_family_kern_keys[AF_MAX];
216 static struct lock_class_key af_family_slock_keys[AF_MAX];
217 static struct lock_class_key af_family_kern_slock_keys[AF_MAX];
218 
219 /*
220  * Make lock validator output more readable. (we pre-construct these
221  * strings build-time, so that runtime initialization of socket
222  * locks is fast):
223  */
224 
225 #define _sock_locks(x)						  \
226   x "AF_UNSPEC",	x "AF_UNIX"     ,	x "AF_INET"     , \
227   x "AF_AX25"  ,	x "AF_IPX"      ,	x "AF_APPLETALK", \
228   x "AF_NETROM",	x "AF_BRIDGE"   ,	x "AF_ATMPVC"   , \
229   x "AF_X25"   ,	x "AF_INET6"    ,	x "AF_ROSE"     , \
230   x "AF_DECnet",	x "AF_NETBEUI"  ,	x "AF_SECURITY" , \
231   x "AF_KEY"   ,	x "AF_NETLINK"  ,	x "AF_PACKET"   , \
232   x "AF_ASH"   ,	x "AF_ECONET"   ,	x "AF_ATMSVC"   , \
233   x "AF_RDS"   ,	x "AF_SNA"      ,	x "AF_IRDA"     , \
234   x "AF_PPPOX" ,	x "AF_WANPIPE"  ,	x "AF_LLC"      , \
235   x "27"       ,	x "28"          ,	x "AF_CAN"      , \
236   x "AF_TIPC"  ,	x "AF_BLUETOOTH",	x "IUCV"        , \
237   x "AF_RXRPC" ,	x "AF_ISDN"     ,	x "AF_PHONET"   , \
238   x "AF_IEEE802154",	x "AF_CAIF"	,	x "AF_ALG"      , \
239   x "AF_NFC"   ,	x "AF_VSOCK"    ,	x "AF_KCM"      , \
240   x "AF_QIPCRTR",	x "AF_SMC"	,	x "AF_XDP"	, \
241   x "AF_MCTP"  , \
242   x "AF_MAX"
243 
244 static const char *const af_family_key_strings[AF_MAX+1] = {
245 	_sock_locks("sk_lock-")
246 };
247 static const char *const af_family_slock_key_strings[AF_MAX+1] = {
248 	_sock_locks("slock-")
249 };
250 static const char *const af_family_clock_key_strings[AF_MAX+1] = {
251 	_sock_locks("clock-")
252 };
253 
254 static const char *const af_family_kern_key_strings[AF_MAX+1] = {
255 	_sock_locks("k-sk_lock-")
256 };
257 static const char *const af_family_kern_slock_key_strings[AF_MAX+1] = {
258 	_sock_locks("k-slock-")
259 };
260 static const char *const af_family_kern_clock_key_strings[AF_MAX+1] = {
261 	_sock_locks("k-clock-")
262 };
263 static const char *const af_family_rlock_key_strings[AF_MAX+1] = {
264 	_sock_locks("rlock-")
265 };
266 static const char *const af_family_wlock_key_strings[AF_MAX+1] = {
267 	_sock_locks("wlock-")
268 };
269 static const char *const af_family_elock_key_strings[AF_MAX+1] = {
270 	_sock_locks("elock-")
271 };
272 
273 /*
274  * sk_callback_lock and sk queues locking rules are per-address-family,
275  * so split the lock classes by using a per-AF key:
276  */
277 static struct lock_class_key af_callback_keys[AF_MAX];
278 static struct lock_class_key af_rlock_keys[AF_MAX];
279 static struct lock_class_key af_wlock_keys[AF_MAX];
280 static struct lock_class_key af_elock_keys[AF_MAX];
281 static struct lock_class_key af_kern_callback_keys[AF_MAX];
282 
283 /* Run time adjustable parameters. */
284 __u32 sysctl_wmem_max __read_mostly = SK_WMEM_MAX;
285 EXPORT_SYMBOL(sysctl_wmem_max);
286 __u32 sysctl_rmem_max __read_mostly = SK_RMEM_MAX;
287 EXPORT_SYMBOL(sysctl_rmem_max);
288 __u32 sysctl_wmem_default __read_mostly = SK_WMEM_MAX;
289 __u32 sysctl_rmem_default __read_mostly = SK_RMEM_MAX;
290 
291 DEFINE_STATIC_KEY_FALSE(memalloc_socks_key);
292 EXPORT_SYMBOL_GPL(memalloc_socks_key);
293 
294 /**
295  * sk_set_memalloc - sets %SOCK_MEMALLOC
296  * @sk: socket to set it on
297  *
298  * Set %SOCK_MEMALLOC on a socket for access to emergency reserves.
299  * It's the responsibility of the admin to adjust min_free_kbytes
300  * to meet the requirements
301  */
sk_set_memalloc(struct sock * sk)302 void sk_set_memalloc(struct sock *sk)
303 {
304 	sock_set_flag(sk, SOCK_MEMALLOC);
305 	sk->sk_allocation |= __GFP_MEMALLOC;
306 	static_branch_inc(&memalloc_socks_key);
307 }
308 EXPORT_SYMBOL_GPL(sk_set_memalloc);
309 
sk_clear_memalloc(struct sock * sk)310 void sk_clear_memalloc(struct sock *sk)
311 {
312 	sock_reset_flag(sk, SOCK_MEMALLOC);
313 	sk->sk_allocation &= ~__GFP_MEMALLOC;
314 	static_branch_dec(&memalloc_socks_key);
315 
316 	/*
317 	 * SOCK_MEMALLOC is allowed to ignore rmem limits to ensure forward
318 	 * progress of swapping. SOCK_MEMALLOC may be cleared while
319 	 * it has rmem allocations due to the last swapfile being deactivated
320 	 * but there is a risk that the socket is unusable due to exceeding
321 	 * the rmem limits. Reclaim the reserves and obey rmem limits again.
322 	 */
323 	sk_mem_reclaim(sk);
324 }
325 EXPORT_SYMBOL_GPL(sk_clear_memalloc);
326 
__sk_backlog_rcv(struct sock * sk,struct sk_buff * skb)327 int __sk_backlog_rcv(struct sock *sk, struct sk_buff *skb)
328 {
329 	int ret;
330 	unsigned int noreclaim_flag;
331 
332 	/* these should have been dropped before queueing */
333 	BUG_ON(!sock_flag(sk, SOCK_MEMALLOC));
334 
335 	noreclaim_flag = memalloc_noreclaim_save();
336 	ret = INDIRECT_CALL_INET(sk->sk_backlog_rcv,
337 				 tcp_v6_do_rcv,
338 				 tcp_v4_do_rcv,
339 				 sk, skb);
340 	memalloc_noreclaim_restore(noreclaim_flag);
341 
342 	return ret;
343 }
344 EXPORT_SYMBOL(__sk_backlog_rcv);
345 
sk_error_report(struct sock * sk)346 void sk_error_report(struct sock *sk)
347 {
348 	sk->sk_error_report(sk);
349 
350 	switch (sk->sk_family) {
351 	case AF_INET:
352 		fallthrough;
353 	case AF_INET6:
354 		trace_inet_sk_error_report(sk);
355 		break;
356 	default:
357 		break;
358 	}
359 }
360 EXPORT_SYMBOL(sk_error_report);
361 
sock_get_timeout(long timeo,void * optval,bool old_timeval)362 int sock_get_timeout(long timeo, void *optval, bool old_timeval)
363 {
364 	struct __kernel_sock_timeval tv;
365 
366 	if (timeo == MAX_SCHEDULE_TIMEOUT) {
367 		tv.tv_sec = 0;
368 		tv.tv_usec = 0;
369 	} else {
370 		tv.tv_sec = timeo / HZ;
371 		tv.tv_usec = ((timeo % HZ) * USEC_PER_SEC) / HZ;
372 	}
373 
374 	if (old_timeval && in_compat_syscall() && !COMPAT_USE_64BIT_TIME) {
375 		struct old_timeval32 tv32 = { tv.tv_sec, tv.tv_usec };
376 		*(struct old_timeval32 *)optval = tv32;
377 		return sizeof(tv32);
378 	}
379 
380 	if (old_timeval) {
381 		struct __kernel_old_timeval old_tv;
382 		old_tv.tv_sec = tv.tv_sec;
383 		old_tv.tv_usec = tv.tv_usec;
384 		*(struct __kernel_old_timeval *)optval = old_tv;
385 		return sizeof(old_tv);
386 	}
387 
388 	*(struct __kernel_sock_timeval *)optval = tv;
389 	return sizeof(tv);
390 }
391 EXPORT_SYMBOL(sock_get_timeout);
392 
sock_copy_user_timeval(struct __kernel_sock_timeval * tv,sockptr_t optval,int optlen,bool old_timeval)393 int sock_copy_user_timeval(struct __kernel_sock_timeval *tv,
394 			   sockptr_t optval, int optlen, bool old_timeval)
395 {
396 	if (old_timeval && in_compat_syscall() && !COMPAT_USE_64BIT_TIME) {
397 		struct old_timeval32 tv32;
398 
399 		if (optlen < sizeof(tv32))
400 			return -EINVAL;
401 
402 		if (copy_from_sockptr(&tv32, optval, sizeof(tv32)))
403 			return -EFAULT;
404 		tv->tv_sec = tv32.tv_sec;
405 		tv->tv_usec = tv32.tv_usec;
406 	} else if (old_timeval) {
407 		struct __kernel_old_timeval old_tv;
408 
409 		if (optlen < sizeof(old_tv))
410 			return -EINVAL;
411 		if (copy_from_sockptr(&old_tv, optval, sizeof(old_tv)))
412 			return -EFAULT;
413 		tv->tv_sec = old_tv.tv_sec;
414 		tv->tv_usec = old_tv.tv_usec;
415 	} else {
416 		if (optlen < sizeof(*tv))
417 			return -EINVAL;
418 		if (copy_from_sockptr(tv, optval, sizeof(*tv)))
419 			return -EFAULT;
420 	}
421 
422 	return 0;
423 }
424 EXPORT_SYMBOL(sock_copy_user_timeval);
425 
sock_set_timeout(long * timeo_p,sockptr_t optval,int optlen,bool old_timeval)426 static int sock_set_timeout(long *timeo_p, sockptr_t optval, int optlen,
427 			    bool old_timeval)
428 {
429 	struct __kernel_sock_timeval tv;
430 	int err = sock_copy_user_timeval(&tv, optval, optlen, old_timeval);
431 	long val;
432 
433 	if (err)
434 		return err;
435 
436 	if (tv.tv_usec < 0 || tv.tv_usec >= USEC_PER_SEC)
437 		return -EDOM;
438 
439 	if (tv.tv_sec < 0) {
440 		static int warned __read_mostly;
441 
442 		WRITE_ONCE(*timeo_p, 0);
443 		if (warned < 10 && net_ratelimit()) {
444 			warned++;
445 			pr_info("%s: `%s' (pid %d) tries to set negative timeout\n",
446 				__func__, current->comm, task_pid_nr(current));
447 		}
448 		return 0;
449 	}
450 	val = MAX_SCHEDULE_TIMEOUT;
451 	if ((tv.tv_sec || tv.tv_usec) &&
452 	    (tv.tv_sec < (MAX_SCHEDULE_TIMEOUT / HZ - 1)))
453 		val = tv.tv_sec * HZ + DIV_ROUND_UP((unsigned long)tv.tv_usec,
454 						    USEC_PER_SEC / HZ);
455 	WRITE_ONCE(*timeo_p, val);
456 	return 0;
457 }
458 
sk_set_prio_allowed(const struct sock * sk,int val)459 static bool sk_set_prio_allowed(const struct sock *sk, int val)
460 {
461 	return ((val >= TC_PRIO_BESTEFFORT && val <= TC_PRIO_INTERACTIVE) ||
462 		sockopt_ns_capable(sock_net(sk)->user_ns, CAP_NET_RAW) ||
463 		sockopt_ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN));
464 }
465 
sock_needs_netstamp(const struct sock * sk)466 static bool sock_needs_netstamp(const struct sock *sk)
467 {
468 	switch (sk->sk_family) {
469 	case AF_UNSPEC:
470 	case AF_UNIX:
471 		return false;
472 	default:
473 		return true;
474 	}
475 }
476 
sock_disable_timestamp(struct sock * sk,unsigned long flags)477 static void sock_disable_timestamp(struct sock *sk, unsigned long flags)
478 {
479 	if (sk->sk_flags & flags) {
480 		sk->sk_flags &= ~flags;
481 		if (sock_needs_netstamp(sk) &&
482 		    !(sk->sk_flags & SK_FLAGS_TIMESTAMP))
483 			net_disable_timestamp();
484 	}
485 }
486 
487 
__sock_queue_rcv_skb(struct sock * sk,struct sk_buff * skb)488 int __sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
489 {
490 	unsigned long flags;
491 	struct sk_buff_head *list = &sk->sk_receive_queue;
492 
493 	if (atomic_read(&sk->sk_rmem_alloc) >= READ_ONCE(sk->sk_rcvbuf)) {
494 		atomic_inc(&sk->sk_drops);
495 		trace_sock_rcvqueue_full(sk, skb);
496 		return -ENOMEM;
497 	}
498 
499 	if (!sk_rmem_schedule(sk, skb, skb->truesize)) {
500 		atomic_inc(&sk->sk_drops);
501 		return -ENOBUFS;
502 	}
503 
504 	skb->dev = NULL;
505 	skb_set_owner_r(skb, sk);
506 
507 	/* we escape from rcu protected region, make sure we dont leak
508 	 * a norefcounted dst
509 	 */
510 	skb_dst_force(skb);
511 
512 	spin_lock_irqsave(&list->lock, flags);
513 	sock_skb_set_dropcount(sk, skb);
514 	__skb_queue_tail(list, skb);
515 	spin_unlock_irqrestore(&list->lock, flags);
516 
517 	if (!sock_flag(sk, SOCK_DEAD))
518 		sk->sk_data_ready(sk);
519 	return 0;
520 }
521 EXPORT_SYMBOL(__sock_queue_rcv_skb);
522 
sock_queue_rcv_skb_reason(struct sock * sk,struct sk_buff * skb,enum skb_drop_reason * reason)523 int sock_queue_rcv_skb_reason(struct sock *sk, struct sk_buff *skb,
524 			      enum skb_drop_reason *reason)
525 {
526 	enum skb_drop_reason drop_reason;
527 	int err;
528 
529 	err = sk_filter_reason(sk, skb, &drop_reason);
530 	if (err)
531 		goto out;
532 
533 	err = __sock_queue_rcv_skb(sk, skb);
534 	switch (err) {
535 	case -ENOMEM:
536 		drop_reason = SKB_DROP_REASON_SOCKET_RCVBUFF;
537 		break;
538 	case -ENOBUFS:
539 		drop_reason = SKB_DROP_REASON_PROTO_MEM;
540 		break;
541 	default:
542 		drop_reason = SKB_NOT_DROPPED_YET;
543 		break;
544 	}
545 out:
546 	if (reason)
547 		*reason = drop_reason;
548 	return err;
549 }
550 EXPORT_SYMBOL(sock_queue_rcv_skb_reason);
551 
__sk_receive_skb(struct sock * sk,struct sk_buff * skb,const int nested,unsigned int trim_cap,bool refcounted)552 int __sk_receive_skb(struct sock *sk, struct sk_buff *skb,
553 		     const int nested, unsigned int trim_cap, bool refcounted)
554 {
555 	enum skb_drop_reason reason = SKB_DROP_REASON_NOT_SPECIFIED;
556 	int rc = NET_RX_SUCCESS;
557 	int err;
558 
559 	if (sk_filter_trim_cap(sk, skb, trim_cap, &reason))
560 		goto discard_and_relse;
561 
562 	skb->dev = NULL;
563 
564 	if (sk_rcvqueues_full(sk, READ_ONCE(sk->sk_rcvbuf))) {
565 		atomic_inc(&sk->sk_drops);
566 		reason = SKB_DROP_REASON_SOCKET_RCVBUFF;
567 		goto discard_and_relse;
568 	}
569 	if (nested)
570 		bh_lock_sock_nested(sk);
571 	else
572 		bh_lock_sock(sk);
573 	if (!sock_owned_by_user(sk)) {
574 		/*
575 		 * trylock + unlock semantics:
576 		 */
577 		mutex_acquire(&sk->sk_lock.dep_map, 0, 1, _RET_IP_);
578 
579 		rc = sk_backlog_rcv(sk, skb);
580 
581 		mutex_release(&sk->sk_lock.dep_map, _RET_IP_);
582 	} else if ((err = sk_add_backlog(sk, skb, READ_ONCE(sk->sk_rcvbuf)))) {
583 		bh_unlock_sock(sk);
584 		if (err == -ENOMEM)
585 			reason = SKB_DROP_REASON_PFMEMALLOC;
586 		if (err == -ENOBUFS)
587 			reason = SKB_DROP_REASON_SOCKET_BACKLOG;
588 		atomic_inc(&sk->sk_drops);
589 		goto discard_and_relse;
590 	}
591 
592 	bh_unlock_sock(sk);
593 out:
594 	if (refcounted)
595 		sock_put(sk);
596 	return rc;
597 discard_and_relse:
598 	sk_skb_reason_drop(sk, skb, reason);
599 	goto out;
600 }
601 EXPORT_SYMBOL(__sk_receive_skb);
602 
603 INDIRECT_CALLABLE_DECLARE(struct dst_entry *ip6_dst_check(struct dst_entry *,
604 							  u32));
605 INDIRECT_CALLABLE_DECLARE(struct dst_entry *ipv4_dst_check(struct dst_entry *,
606 							   u32));
__sk_dst_check(struct sock * sk,u32 cookie)607 struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie)
608 {
609 	struct dst_entry *dst = __sk_dst_get(sk);
610 
611 	if (dst && READ_ONCE(dst->obsolete) &&
612 	    INDIRECT_CALL_INET(dst->ops->check, ip6_dst_check, ipv4_dst_check,
613 			       dst, cookie) == NULL) {
614 		sk_tx_queue_clear(sk);
615 		WRITE_ONCE(sk->sk_dst_pending_confirm, 0);
616 		RCU_INIT_POINTER(sk->sk_dst_cache, NULL);
617 		dst_release(dst);
618 		return NULL;
619 	}
620 
621 	return dst;
622 }
623 EXPORT_SYMBOL(__sk_dst_check);
624 
sk_dst_check(struct sock * sk,u32 cookie)625 struct dst_entry *sk_dst_check(struct sock *sk, u32 cookie)
626 {
627 	struct dst_entry *dst = sk_dst_get(sk);
628 
629 	if (dst && READ_ONCE(dst->obsolete) &&
630 	    INDIRECT_CALL_INET(dst->ops->check, ip6_dst_check, ipv4_dst_check,
631 			       dst, cookie) == NULL) {
632 		sk_dst_reset(sk);
633 		dst_release(dst);
634 		return NULL;
635 	}
636 
637 	return dst;
638 }
639 EXPORT_SYMBOL(sk_dst_check);
640 
sock_bindtoindex_locked(struct sock * sk,int ifindex)641 static int sock_bindtoindex_locked(struct sock *sk, int ifindex)
642 {
643 	int ret = -ENOPROTOOPT;
644 #ifdef CONFIG_NETDEVICES
645 	struct net *net = sock_net(sk);
646 
647 	/* Sorry... */
648 	ret = -EPERM;
649 	if (sk->sk_bound_dev_if && !ns_capable(net->user_ns, CAP_NET_RAW))
650 		goto out;
651 
652 	ret = -EINVAL;
653 	if (ifindex < 0)
654 		goto out;
655 
656 	/* Paired with all READ_ONCE() done locklessly. */
657 	WRITE_ONCE(sk->sk_bound_dev_if, ifindex);
658 
659 	if (sk->sk_prot->rehash)
660 		sk->sk_prot->rehash(sk);
661 	sk_dst_reset(sk);
662 
663 	ret = 0;
664 
665 out:
666 #endif
667 
668 	return ret;
669 }
670 
sock_bindtoindex(struct sock * sk,int ifindex,bool lock_sk)671 int sock_bindtoindex(struct sock *sk, int ifindex, bool lock_sk)
672 {
673 	int ret;
674 
675 	if (lock_sk)
676 		lock_sock(sk);
677 	ret = sock_bindtoindex_locked(sk, ifindex);
678 	if (lock_sk)
679 		release_sock(sk);
680 
681 	return ret;
682 }
683 EXPORT_SYMBOL(sock_bindtoindex);
684 
sock_setbindtodevice(struct sock * sk,sockptr_t optval,int optlen)685 static int sock_setbindtodevice(struct sock *sk, sockptr_t optval, int optlen)
686 {
687 	int ret = -ENOPROTOOPT;
688 #ifdef CONFIG_NETDEVICES
689 	struct net *net = sock_net(sk);
690 	char devname[IFNAMSIZ];
691 	int index;
692 
693 	ret = -EINVAL;
694 	if (optlen < 0)
695 		goto out;
696 
697 	/* Bind this socket to a particular device like "eth0",
698 	 * as specified in the passed interface name. If the
699 	 * name is "" or the option length is zero the socket
700 	 * is not bound.
701 	 */
702 	if (optlen > IFNAMSIZ - 1)
703 		optlen = IFNAMSIZ - 1;
704 	memset(devname, 0, sizeof(devname));
705 
706 	ret = -EFAULT;
707 	if (copy_from_sockptr(devname, optval, optlen))
708 		goto out;
709 
710 	index = 0;
711 	if (devname[0] != '\0') {
712 		struct net_device *dev;
713 
714 		rcu_read_lock();
715 		dev = dev_get_by_name_rcu(net, devname);
716 		if (dev)
717 			index = dev->ifindex;
718 		rcu_read_unlock();
719 		ret = -ENODEV;
720 		if (!dev)
721 			goto out;
722 	}
723 
724 	sockopt_lock_sock(sk);
725 	ret = sock_bindtoindex_locked(sk, index);
726 	sockopt_release_sock(sk);
727 out:
728 #endif
729 
730 	return ret;
731 }
732 
sock_getbindtodevice(struct sock * sk,sockptr_t optval,sockptr_t optlen,int len)733 static int sock_getbindtodevice(struct sock *sk, sockptr_t optval,
734 				sockptr_t optlen, int len)
735 {
736 	int ret = -ENOPROTOOPT;
737 #ifdef CONFIG_NETDEVICES
738 	int bound_dev_if = READ_ONCE(sk->sk_bound_dev_if);
739 	struct net *net = sock_net(sk);
740 	char devname[IFNAMSIZ];
741 
742 	if (bound_dev_if == 0) {
743 		len = 0;
744 		goto zero;
745 	}
746 
747 	ret = -EINVAL;
748 	if (len < IFNAMSIZ)
749 		goto out;
750 
751 	ret = netdev_get_name(net, devname, bound_dev_if);
752 	if (ret)
753 		goto out;
754 
755 	len = strlen(devname) + 1;
756 
757 	ret = -EFAULT;
758 	if (copy_to_sockptr(optval, devname, len))
759 		goto out;
760 
761 zero:
762 	ret = -EFAULT;
763 	if (copy_to_sockptr(optlen, &len, sizeof(int)))
764 		goto out;
765 
766 	ret = 0;
767 
768 out:
769 #endif
770 
771 	return ret;
772 }
773 
sk_mc_loop(const struct sock * sk)774 bool sk_mc_loop(const struct sock *sk)
775 {
776 	if (dev_recursion_level())
777 		return false;
778 	if (!sk)
779 		return true;
780 	/* IPV6_ADDRFORM can change sk->sk_family under us. */
781 	switch (READ_ONCE(sk->sk_family)) {
782 	case AF_INET:
783 		return inet_test_bit(MC_LOOP, sk);
784 #if IS_ENABLED(CONFIG_IPV6)
785 	case AF_INET6:
786 		return inet6_test_bit(MC6_LOOP, sk);
787 #endif
788 	}
789 	WARN_ON_ONCE(1);
790 	return true;
791 }
792 EXPORT_SYMBOL(sk_mc_loop);
793 
sock_set_reuseaddr(struct sock * sk)794 void sock_set_reuseaddr(struct sock *sk)
795 {
796 	lock_sock(sk);
797 	sk->sk_reuse = SK_CAN_REUSE;
798 	release_sock(sk);
799 }
800 EXPORT_SYMBOL(sock_set_reuseaddr);
801 
sock_set_reuseport(struct sock * sk)802 void sock_set_reuseport(struct sock *sk)
803 {
804 	lock_sock(sk);
805 	sk->sk_reuseport = true;
806 	release_sock(sk);
807 }
808 EXPORT_SYMBOL(sock_set_reuseport);
809 
sock_no_linger(struct sock * sk)810 void sock_no_linger(struct sock *sk)
811 {
812 	lock_sock(sk);
813 	WRITE_ONCE(sk->sk_lingertime, 0);
814 	sock_set_flag(sk, SOCK_LINGER);
815 	release_sock(sk);
816 }
817 EXPORT_SYMBOL(sock_no_linger);
818 
sock_set_priority(struct sock * sk,u32 priority)819 void sock_set_priority(struct sock *sk, u32 priority)
820 {
821 	WRITE_ONCE(sk->sk_priority, priority);
822 }
823 EXPORT_SYMBOL(sock_set_priority);
824 
sock_set_sndtimeo(struct sock * sk,s64 secs)825 void sock_set_sndtimeo(struct sock *sk, s64 secs)
826 {
827 	if (secs && secs < MAX_SCHEDULE_TIMEOUT / HZ - 1)
828 		WRITE_ONCE(sk->sk_sndtimeo, secs * HZ);
829 	else
830 		WRITE_ONCE(sk->sk_sndtimeo, MAX_SCHEDULE_TIMEOUT);
831 }
832 EXPORT_SYMBOL(sock_set_sndtimeo);
833 
__sock_set_timestamps(struct sock * sk,bool val,bool new,bool ns)834 static void __sock_set_timestamps(struct sock *sk, bool val, bool new, bool ns)
835 {
836 	sock_valbool_flag(sk, SOCK_RCVTSTAMP, val);
837 	sock_valbool_flag(sk, SOCK_RCVTSTAMPNS, val && ns);
838 	if (val)  {
839 		sock_valbool_flag(sk, SOCK_TSTAMP_NEW, new);
840 		sock_enable_timestamp(sk, SOCK_TIMESTAMP);
841 	}
842 }
843 
sock_set_timestamp(struct sock * sk,int optname,bool valbool)844 void sock_set_timestamp(struct sock *sk, int optname, bool valbool)
845 {
846 	switch (optname) {
847 	case SO_TIMESTAMP_OLD:
848 		__sock_set_timestamps(sk, valbool, false, false);
849 		break;
850 	case SO_TIMESTAMP_NEW:
851 		__sock_set_timestamps(sk, valbool, true, false);
852 		break;
853 	case SO_TIMESTAMPNS_OLD:
854 		__sock_set_timestamps(sk, valbool, false, true);
855 		break;
856 	case SO_TIMESTAMPNS_NEW:
857 		__sock_set_timestamps(sk, valbool, true, true);
858 		break;
859 	}
860 }
861 
sock_timestamping_bind_phc(struct sock * sk,int phc_index)862 static int sock_timestamping_bind_phc(struct sock *sk, int phc_index)
863 {
864 	struct net *net = sock_net(sk);
865 	struct net_device *dev = NULL;
866 	bool match = false;
867 	int *vclock_index;
868 	int i, num;
869 
870 	if (sk->sk_bound_dev_if)
871 		dev = dev_get_by_index(net, sk->sk_bound_dev_if);
872 
873 	if (!dev) {
874 		pr_err("%s: sock not bind to device\n", __func__);
875 		return -EOPNOTSUPP;
876 	}
877 
878 	num = ethtool_get_phc_vclocks(dev, &vclock_index);
879 	dev_put(dev);
880 
881 	for (i = 0; i < num; i++) {
882 		if (*(vclock_index + i) == phc_index) {
883 			match = true;
884 			break;
885 		}
886 	}
887 
888 	if (num > 0)
889 		kfree(vclock_index);
890 
891 	if (!match)
892 		return -EINVAL;
893 
894 	WRITE_ONCE(sk->sk_bind_phc, phc_index);
895 
896 	return 0;
897 }
898 
sock_set_timestamping(struct sock * sk,int optname,struct so_timestamping timestamping)899 int sock_set_timestamping(struct sock *sk, int optname,
900 			  struct so_timestamping timestamping)
901 {
902 	int val = timestamping.flags;
903 	int ret;
904 
905 	if (val & ~SOF_TIMESTAMPING_MASK)
906 		return -EINVAL;
907 
908 	if (val & SOF_TIMESTAMPING_OPT_ID_TCP &&
909 	    !(val & SOF_TIMESTAMPING_OPT_ID))
910 		return -EINVAL;
911 
912 	if (val & SOF_TIMESTAMPING_OPT_ID &&
913 	    !(sk->sk_tsflags & SOF_TIMESTAMPING_OPT_ID)) {
914 		if (sk_is_tcp(sk)) {
915 			if ((1 << sk->sk_state) &
916 			    (TCPF_CLOSE | TCPF_LISTEN))
917 				return -EINVAL;
918 			if (val & SOF_TIMESTAMPING_OPT_ID_TCP)
919 				atomic_set(&sk->sk_tskey, tcp_sk(sk)->write_seq);
920 			else
921 				atomic_set(&sk->sk_tskey, tcp_sk(sk)->snd_una);
922 		} else {
923 			atomic_set(&sk->sk_tskey, 0);
924 		}
925 	}
926 
927 	if (val & SOF_TIMESTAMPING_OPT_STATS &&
928 	    !(val & SOF_TIMESTAMPING_OPT_TSONLY))
929 		return -EINVAL;
930 
931 	if (val & SOF_TIMESTAMPING_BIND_PHC) {
932 		ret = sock_timestamping_bind_phc(sk, timestamping.bind_phc);
933 		if (ret)
934 			return ret;
935 	}
936 
937 	WRITE_ONCE(sk->sk_tsflags, val);
938 	sock_valbool_flag(sk, SOCK_TSTAMP_NEW, optname == SO_TIMESTAMPING_NEW);
939 	sock_valbool_flag(sk, SOCK_TIMESTAMPING_ANY, !!(val & TSFLAGS_ANY));
940 
941 	if (val & SOF_TIMESTAMPING_RX_SOFTWARE)
942 		sock_enable_timestamp(sk,
943 				      SOCK_TIMESTAMPING_RX_SOFTWARE);
944 	else
945 		sock_disable_timestamp(sk,
946 				       (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE));
947 	return 0;
948 }
949 
950 #if defined(CONFIG_CGROUP_BPF)
bpf_skops_tx_timestamping(struct sock * sk,struct sk_buff * skb,int op)951 void bpf_skops_tx_timestamping(struct sock *sk, struct sk_buff *skb, int op)
952 {
953 	struct bpf_sock_ops_kern sock_ops;
954 
955 	memset(&sock_ops, 0, offsetof(struct bpf_sock_ops_kern, temp));
956 	sock_ops.op = op;
957 	sock_ops.is_fullsock = 1;
958 	sock_ops.sk = sk;
959 	bpf_skops_init_skb(&sock_ops, skb, 0);
960 	__cgroup_bpf_run_filter_sock_ops(sk, &sock_ops, CGROUP_SOCK_OPS);
961 }
962 #endif
963 
sock_set_keepalive(struct sock * sk)964 void sock_set_keepalive(struct sock *sk)
965 {
966 	lock_sock(sk);
967 	if (sk->sk_prot->keepalive)
968 		sk->sk_prot->keepalive(sk, true);
969 	sock_valbool_flag(sk, SOCK_KEEPOPEN, true);
970 	release_sock(sk);
971 }
972 EXPORT_SYMBOL(sock_set_keepalive);
973 
__sock_set_rcvbuf(struct sock * sk,int val)974 static void __sock_set_rcvbuf(struct sock *sk, int val)
975 {
976 	/* Ensure val * 2 fits into an int, to prevent max_t() from treating it
977 	 * as a negative value.
978 	 */
979 	val = min_t(int, val, INT_MAX / 2);
980 	sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
981 
982 	/* We double it on the way in to account for "struct sk_buff" etc.
983 	 * overhead.   Applications assume that the SO_RCVBUF setting they make
984 	 * will allow that much actual data to be received on that socket.
985 	 *
986 	 * Applications are unaware that "struct sk_buff" and other overheads
987 	 * allocate from the receive buffer during socket buffer allocation.
988 	 *
989 	 * And after considering the possible alternatives, returning the value
990 	 * we actually used in getsockopt is the most desirable behavior.
991 	 */
992 	WRITE_ONCE(sk->sk_rcvbuf, max_t(int, val * 2, SOCK_MIN_RCVBUF));
993 }
994 
sock_set_rcvbuf(struct sock * sk,int val)995 void sock_set_rcvbuf(struct sock *sk, int val)
996 {
997 	lock_sock(sk);
998 	__sock_set_rcvbuf(sk, val);
999 	release_sock(sk);
1000 }
1001 EXPORT_SYMBOL(sock_set_rcvbuf);
1002 
__sock_set_mark(struct sock * sk,u32 val)1003 static void __sock_set_mark(struct sock *sk, u32 val)
1004 {
1005 	if (val != sk->sk_mark) {
1006 		WRITE_ONCE(sk->sk_mark, val);
1007 		sk_dst_reset(sk);
1008 	}
1009 }
1010 
sock_set_mark(struct sock * sk,u32 val)1011 void sock_set_mark(struct sock *sk, u32 val)
1012 {
1013 	lock_sock(sk);
1014 	__sock_set_mark(sk, val);
1015 	release_sock(sk);
1016 }
1017 EXPORT_SYMBOL(sock_set_mark);
1018 
sock_release_reserved_memory(struct sock * sk,int bytes)1019 static void sock_release_reserved_memory(struct sock *sk, int bytes)
1020 {
1021 	/* Round down bytes to multiple of pages */
1022 	bytes = round_down(bytes, PAGE_SIZE);
1023 
1024 	WARN_ON(bytes > sk->sk_reserved_mem);
1025 	WRITE_ONCE(sk->sk_reserved_mem, sk->sk_reserved_mem - bytes);
1026 	sk_mem_reclaim(sk);
1027 }
1028 
sock_reserve_memory(struct sock * sk,int bytes)1029 static int sock_reserve_memory(struct sock *sk, int bytes)
1030 {
1031 	long allocated;
1032 	bool charged;
1033 	int pages;
1034 
1035 	if (!mem_cgroup_sockets_enabled || !sk->sk_memcg || !sk_has_account(sk))
1036 		return -EOPNOTSUPP;
1037 
1038 	if (!bytes)
1039 		return 0;
1040 
1041 	pages = sk_mem_pages(bytes);
1042 
1043 	/* pre-charge to memcg */
1044 	charged = mem_cgroup_charge_skmem(sk->sk_memcg, pages,
1045 					  GFP_KERNEL | __GFP_RETRY_MAYFAIL);
1046 	if (!charged)
1047 		return -ENOMEM;
1048 
1049 	/* pre-charge to forward_alloc */
1050 	sk_memory_allocated_add(sk, pages);
1051 	allocated = sk_memory_allocated(sk);
1052 	/* If the system goes into memory pressure with this
1053 	 * precharge, give up and return error.
1054 	 */
1055 	if (allocated > sk_prot_mem_limits(sk, 1)) {
1056 		sk_memory_allocated_sub(sk, pages);
1057 		mem_cgroup_uncharge_skmem(sk->sk_memcg, pages);
1058 		return -ENOMEM;
1059 	}
1060 	sk_forward_alloc_add(sk, pages << PAGE_SHIFT);
1061 
1062 	WRITE_ONCE(sk->sk_reserved_mem,
1063 		   sk->sk_reserved_mem + (pages << PAGE_SHIFT));
1064 
1065 	return 0;
1066 }
1067 
1068 #ifdef CONFIG_PAGE_POOL
1069 
1070 /* This is the number of tokens and frags that the user can SO_DEVMEM_DONTNEED
1071  * in 1 syscall. The limit exists to limit the amount of memory the kernel
1072  * allocates to copy these tokens, and to prevent looping over the frags for
1073  * too long.
1074  */
1075 #define MAX_DONTNEED_TOKENS 128
1076 #define MAX_DONTNEED_FRAGS 1024
1077 
1078 static noinline_for_stack int
sock_devmem_dontneed(struct sock * sk,sockptr_t optval,unsigned int optlen)1079 sock_devmem_dontneed(struct sock *sk, sockptr_t optval, unsigned int optlen)
1080 {
1081 	unsigned int num_tokens, i, j, k, netmem_num = 0;
1082 	struct dmabuf_token *tokens;
1083 	int ret = 0, num_frags = 0;
1084 	netmem_ref netmems[16];
1085 
1086 	if (!sk_is_tcp(sk))
1087 		return -EBADF;
1088 
1089 	if (optlen % sizeof(*tokens) ||
1090 	    optlen > sizeof(*tokens) * MAX_DONTNEED_TOKENS)
1091 		return -EINVAL;
1092 
1093 	num_tokens = optlen / sizeof(*tokens);
1094 	tokens = kvmalloc_array(num_tokens, sizeof(*tokens), GFP_KERNEL);
1095 	if (!tokens)
1096 		return -ENOMEM;
1097 
1098 	if (copy_from_sockptr(tokens, optval, optlen)) {
1099 		kvfree(tokens);
1100 		return -EFAULT;
1101 	}
1102 
1103 	xa_lock_bh(&sk->sk_user_frags);
1104 	for (i = 0; i < num_tokens; i++) {
1105 		for (j = 0; j < tokens[i].token_count; j++) {
1106 			if (++num_frags > MAX_DONTNEED_FRAGS)
1107 				goto frag_limit_reached;
1108 
1109 			netmem_ref netmem = (__force netmem_ref)__xa_erase(
1110 				&sk->sk_user_frags, tokens[i].token_start + j);
1111 
1112 			if (!netmem || WARN_ON_ONCE(!netmem_is_net_iov(netmem)))
1113 				continue;
1114 
1115 			netmems[netmem_num++] = netmem;
1116 			if (netmem_num == ARRAY_SIZE(netmems)) {
1117 				xa_unlock_bh(&sk->sk_user_frags);
1118 				for (k = 0; k < netmem_num; k++)
1119 					WARN_ON_ONCE(!napi_pp_put_page(netmems[k]));
1120 				netmem_num = 0;
1121 				xa_lock_bh(&sk->sk_user_frags);
1122 			}
1123 			ret++;
1124 		}
1125 	}
1126 
1127 frag_limit_reached:
1128 	xa_unlock_bh(&sk->sk_user_frags);
1129 	for (k = 0; k < netmem_num; k++)
1130 		WARN_ON_ONCE(!napi_pp_put_page(netmems[k]));
1131 
1132 	kvfree(tokens);
1133 	return ret;
1134 }
1135 #endif
1136 
sockopt_lock_sock(struct sock * sk)1137 void sockopt_lock_sock(struct sock *sk)
1138 {
1139 	/* When current->bpf_ctx is set, the setsockopt is called from
1140 	 * a bpf prog.  bpf has ensured the sk lock has been
1141 	 * acquired before calling setsockopt().
1142 	 */
1143 	if (has_current_bpf_ctx())
1144 		return;
1145 
1146 	lock_sock(sk);
1147 }
1148 EXPORT_SYMBOL(sockopt_lock_sock);
1149 
sockopt_release_sock(struct sock * sk)1150 void sockopt_release_sock(struct sock *sk)
1151 {
1152 	if (has_current_bpf_ctx())
1153 		return;
1154 
1155 	release_sock(sk);
1156 }
1157 EXPORT_SYMBOL(sockopt_release_sock);
1158 
sockopt_ns_capable(struct user_namespace * ns,int cap)1159 bool sockopt_ns_capable(struct user_namespace *ns, int cap)
1160 {
1161 	return has_current_bpf_ctx() || ns_capable(ns, cap);
1162 }
1163 EXPORT_SYMBOL(sockopt_ns_capable);
1164 
sockopt_capable(int cap)1165 bool sockopt_capable(int cap)
1166 {
1167 	return has_current_bpf_ctx() || capable(cap);
1168 }
1169 EXPORT_SYMBOL(sockopt_capable);
1170 
sockopt_validate_clockid(__kernel_clockid_t value)1171 static int sockopt_validate_clockid(__kernel_clockid_t value)
1172 {
1173 	switch (value) {
1174 	case CLOCK_REALTIME:
1175 	case CLOCK_MONOTONIC:
1176 	case CLOCK_TAI:
1177 		return 0;
1178 	}
1179 	return -EINVAL;
1180 }
1181 
1182 /*
1183  *	This is meant for all protocols to use and covers goings on
1184  *	at the socket level. Everything here is generic.
1185  */
1186 
sk_setsockopt(struct sock * sk,int level,int optname,sockptr_t optval,unsigned int optlen)1187 int sk_setsockopt(struct sock *sk, int level, int optname,
1188 		  sockptr_t optval, unsigned int optlen)
1189 {
1190 	struct so_timestamping timestamping;
1191 	struct socket *sock = sk->sk_socket;
1192 	struct sock_txtime sk_txtime;
1193 	int val;
1194 	int valbool;
1195 	struct linger ling;
1196 	int ret = 0;
1197 
1198 	/*
1199 	 *	Options without arguments
1200 	 */
1201 
1202 	if (optname == SO_BINDTODEVICE)
1203 		return sock_setbindtodevice(sk, optval, optlen);
1204 
1205 	if (optlen < sizeof(int))
1206 		return -EINVAL;
1207 
1208 	if (copy_from_sockptr(&val, optval, sizeof(val)))
1209 		return -EFAULT;
1210 
1211 	valbool = val ? 1 : 0;
1212 
1213 	/* handle options which do not require locking the socket. */
1214 	switch (optname) {
1215 	case SO_PRIORITY:
1216 		if (sk_set_prio_allowed(sk, val)) {
1217 			sock_set_priority(sk, val);
1218 			return 0;
1219 		}
1220 		return -EPERM;
1221 	case SO_TYPE:
1222 	case SO_PROTOCOL:
1223 	case SO_DOMAIN:
1224 	case SO_ERROR:
1225 		return -ENOPROTOOPT;
1226 #ifdef CONFIG_NET_RX_BUSY_POLL
1227 	case SO_BUSY_POLL:
1228 		if (val < 0)
1229 			return -EINVAL;
1230 		WRITE_ONCE(sk->sk_ll_usec, val);
1231 		return 0;
1232 	case SO_PREFER_BUSY_POLL:
1233 		if (valbool && !sockopt_capable(CAP_NET_ADMIN))
1234 			return -EPERM;
1235 		WRITE_ONCE(sk->sk_prefer_busy_poll, valbool);
1236 		return 0;
1237 	case SO_BUSY_POLL_BUDGET:
1238 		if (val > READ_ONCE(sk->sk_busy_poll_budget) &&
1239 		    !sockopt_capable(CAP_NET_ADMIN))
1240 			return -EPERM;
1241 		if (val < 0 || val > U16_MAX)
1242 			return -EINVAL;
1243 		WRITE_ONCE(sk->sk_busy_poll_budget, val);
1244 		return 0;
1245 #endif
1246 	case SO_MAX_PACING_RATE:
1247 		{
1248 		unsigned long ulval = (val == ~0U) ? ~0UL : (unsigned int)val;
1249 		unsigned long pacing_rate;
1250 
1251 		if (sizeof(ulval) != sizeof(val) &&
1252 		    optlen >= sizeof(ulval) &&
1253 		    copy_from_sockptr(&ulval, optval, sizeof(ulval))) {
1254 			return -EFAULT;
1255 		}
1256 		if (ulval != ~0UL)
1257 			cmpxchg(&sk->sk_pacing_status,
1258 				SK_PACING_NONE,
1259 				SK_PACING_NEEDED);
1260 		/* Pairs with READ_ONCE() from sk_getsockopt() */
1261 		WRITE_ONCE(sk->sk_max_pacing_rate, ulval);
1262 		pacing_rate = READ_ONCE(sk->sk_pacing_rate);
1263 		if (ulval < pacing_rate)
1264 			WRITE_ONCE(sk->sk_pacing_rate, ulval);
1265 		return 0;
1266 		}
1267 	case SO_TXREHASH:
1268 		if (!sk_is_tcp(sk))
1269 			return -EOPNOTSUPP;
1270 		if (val < -1 || val > 1)
1271 			return -EINVAL;
1272 		if ((u8)val == SOCK_TXREHASH_DEFAULT)
1273 			val = READ_ONCE(sock_net(sk)->core.sysctl_txrehash);
1274 		/* Paired with READ_ONCE() in tcp_rtx_synack()
1275 		 * and sk_getsockopt().
1276 		 */
1277 		WRITE_ONCE(sk->sk_txrehash, (u8)val);
1278 		return 0;
1279 	case SO_PEEK_OFF:
1280 		{
1281 		int (*set_peek_off)(struct sock *sk, int val);
1282 
1283 		set_peek_off = READ_ONCE(sock->ops)->set_peek_off;
1284 		if (set_peek_off)
1285 			ret = set_peek_off(sk, val);
1286 		else
1287 			ret = -EOPNOTSUPP;
1288 		return ret;
1289 		}
1290 #ifdef CONFIG_PAGE_POOL
1291 	case SO_DEVMEM_DONTNEED:
1292 		return sock_devmem_dontneed(sk, optval, optlen);
1293 #endif
1294 	case SO_SNDTIMEO_OLD:
1295 	case SO_SNDTIMEO_NEW:
1296 		return sock_set_timeout(&sk->sk_sndtimeo, optval,
1297 					optlen, optname == SO_SNDTIMEO_OLD);
1298 	case SO_RCVTIMEO_OLD:
1299 	case SO_RCVTIMEO_NEW:
1300 		return sock_set_timeout(&sk->sk_rcvtimeo, optval,
1301 					optlen, optname == SO_RCVTIMEO_OLD);
1302 	}
1303 
1304 	sockopt_lock_sock(sk);
1305 
1306 	switch (optname) {
1307 	case SO_DEBUG:
1308 		if (val && !sockopt_capable(CAP_NET_ADMIN))
1309 			ret = -EACCES;
1310 		else
1311 			sock_valbool_flag(sk, SOCK_DBG, valbool);
1312 		break;
1313 	case SO_REUSEADDR:
1314 		sk->sk_reuse = (valbool ? SK_CAN_REUSE : SK_NO_REUSE);
1315 		break;
1316 	case SO_REUSEPORT:
1317 		if (valbool && !sk_is_inet(sk))
1318 			ret = -EOPNOTSUPP;
1319 		else
1320 			sk->sk_reuseport = valbool;
1321 		break;
1322 	case SO_DONTROUTE:
1323 		sock_valbool_flag(sk, SOCK_LOCALROUTE, valbool);
1324 		sk_dst_reset(sk);
1325 		break;
1326 	case SO_BROADCAST:
1327 		sock_valbool_flag(sk, SOCK_BROADCAST, valbool);
1328 		break;
1329 	case SO_SNDBUF:
1330 		/* Don't error on this BSD doesn't and if you think
1331 		 * about it this is right. Otherwise apps have to
1332 		 * play 'guess the biggest size' games. RCVBUF/SNDBUF
1333 		 * are treated in BSD as hints
1334 		 */
1335 		val = min_t(u32, val, READ_ONCE(sysctl_wmem_max));
1336 set_sndbuf:
1337 		/* Ensure val * 2 fits into an int, to prevent max_t()
1338 		 * from treating it as a negative value.
1339 		 */
1340 		val = min_t(int, val, INT_MAX / 2);
1341 		sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
1342 		WRITE_ONCE(sk->sk_sndbuf,
1343 			   max_t(int, val * 2, SOCK_MIN_SNDBUF));
1344 		/* Wake up sending tasks if we upped the value. */
1345 		sk->sk_write_space(sk);
1346 		break;
1347 
1348 	case SO_SNDBUFFORCE:
1349 		if (!sockopt_capable(CAP_NET_ADMIN)) {
1350 			ret = -EPERM;
1351 			break;
1352 		}
1353 
1354 		/* No negative values (to prevent underflow, as val will be
1355 		 * multiplied by 2).
1356 		 */
1357 		if (val < 0)
1358 			val = 0;
1359 		goto set_sndbuf;
1360 
1361 	case SO_RCVBUF:
1362 		/* Don't error on this BSD doesn't and if you think
1363 		 * about it this is right. Otherwise apps have to
1364 		 * play 'guess the biggest size' games. RCVBUF/SNDBUF
1365 		 * are treated in BSD as hints
1366 		 */
1367 		__sock_set_rcvbuf(sk, min_t(u32, val, READ_ONCE(sysctl_rmem_max)));
1368 		break;
1369 
1370 	case SO_RCVBUFFORCE:
1371 		if (!sockopt_capable(CAP_NET_ADMIN)) {
1372 			ret = -EPERM;
1373 			break;
1374 		}
1375 
1376 		/* No negative values (to prevent underflow, as val will be
1377 		 * multiplied by 2).
1378 		 */
1379 		__sock_set_rcvbuf(sk, max(val, 0));
1380 		break;
1381 
1382 	case SO_KEEPALIVE:
1383 		if (sk->sk_prot->keepalive)
1384 			sk->sk_prot->keepalive(sk, valbool);
1385 		sock_valbool_flag(sk, SOCK_KEEPOPEN, valbool);
1386 		break;
1387 
1388 	case SO_OOBINLINE:
1389 		sock_valbool_flag(sk, SOCK_URGINLINE, valbool);
1390 		break;
1391 
1392 	case SO_NO_CHECK:
1393 		sk->sk_no_check_tx = valbool;
1394 		break;
1395 
1396 	case SO_LINGER:
1397 		if (optlen < sizeof(ling)) {
1398 			ret = -EINVAL;	/* 1003.1g */
1399 			break;
1400 		}
1401 		if (copy_from_sockptr(&ling, optval, sizeof(ling))) {
1402 			ret = -EFAULT;
1403 			break;
1404 		}
1405 		if (!ling.l_onoff) {
1406 			sock_reset_flag(sk, SOCK_LINGER);
1407 		} else {
1408 			unsigned long t_sec = ling.l_linger;
1409 
1410 			if (t_sec >= MAX_SCHEDULE_TIMEOUT / HZ)
1411 				WRITE_ONCE(sk->sk_lingertime, MAX_SCHEDULE_TIMEOUT);
1412 			else
1413 				WRITE_ONCE(sk->sk_lingertime, t_sec * HZ);
1414 			sock_set_flag(sk, SOCK_LINGER);
1415 		}
1416 		break;
1417 
1418 	case SO_BSDCOMPAT:
1419 		break;
1420 
1421 	case SO_TIMESTAMP_OLD:
1422 	case SO_TIMESTAMP_NEW:
1423 	case SO_TIMESTAMPNS_OLD:
1424 	case SO_TIMESTAMPNS_NEW:
1425 		sock_set_timestamp(sk, optname, valbool);
1426 		break;
1427 
1428 	case SO_TIMESTAMPING_NEW:
1429 	case SO_TIMESTAMPING_OLD:
1430 		if (optlen == sizeof(timestamping)) {
1431 			if (copy_from_sockptr(&timestamping, optval,
1432 					      sizeof(timestamping))) {
1433 				ret = -EFAULT;
1434 				break;
1435 			}
1436 		} else {
1437 			memset(&timestamping, 0, sizeof(timestamping));
1438 			timestamping.flags = val;
1439 		}
1440 		ret = sock_set_timestamping(sk, optname, timestamping);
1441 		break;
1442 
1443 	case SO_RCVLOWAT:
1444 		{
1445 		int (*set_rcvlowat)(struct sock *sk, int val) = NULL;
1446 
1447 		if (val < 0)
1448 			val = INT_MAX;
1449 		if (sock)
1450 			set_rcvlowat = READ_ONCE(sock->ops)->set_rcvlowat;
1451 		if (set_rcvlowat)
1452 			ret = set_rcvlowat(sk, val);
1453 		else
1454 			WRITE_ONCE(sk->sk_rcvlowat, val ? : 1);
1455 		break;
1456 		}
1457 	case SO_ATTACH_FILTER: {
1458 		struct sock_fprog fprog;
1459 
1460 		ret = copy_bpf_fprog_from_user(&fprog, optval, optlen);
1461 		if (!ret)
1462 			ret = sk_attach_filter(&fprog, sk);
1463 		break;
1464 	}
1465 	case SO_ATTACH_BPF:
1466 		ret = -EINVAL;
1467 		if (optlen == sizeof(u32)) {
1468 			u32 ufd;
1469 
1470 			ret = -EFAULT;
1471 			if (copy_from_sockptr(&ufd, optval, sizeof(ufd)))
1472 				break;
1473 
1474 			ret = sk_attach_bpf(ufd, sk);
1475 		}
1476 		break;
1477 
1478 	case SO_ATTACH_REUSEPORT_CBPF: {
1479 		struct sock_fprog fprog;
1480 
1481 		ret = copy_bpf_fprog_from_user(&fprog, optval, optlen);
1482 		if (!ret)
1483 			ret = sk_reuseport_attach_filter(&fprog, sk);
1484 		break;
1485 	}
1486 	case SO_ATTACH_REUSEPORT_EBPF:
1487 		ret = -EINVAL;
1488 		if (optlen == sizeof(u32)) {
1489 			u32 ufd;
1490 
1491 			ret = -EFAULT;
1492 			if (copy_from_sockptr(&ufd, optval, sizeof(ufd)))
1493 				break;
1494 
1495 			ret = sk_reuseport_attach_bpf(ufd, sk);
1496 		}
1497 		break;
1498 
1499 	case SO_DETACH_REUSEPORT_BPF:
1500 		ret = reuseport_detach_prog(sk);
1501 		break;
1502 
1503 	case SO_DETACH_FILTER:
1504 		ret = sk_detach_filter(sk);
1505 		break;
1506 
1507 	case SO_LOCK_FILTER:
1508 		if (sock_flag(sk, SOCK_FILTER_LOCKED) && !valbool)
1509 			ret = -EPERM;
1510 		else
1511 			sock_valbool_flag(sk, SOCK_FILTER_LOCKED, valbool);
1512 		break;
1513 
1514 	case SO_MARK:
1515 		if (!sockopt_ns_capable(sock_net(sk)->user_ns, CAP_NET_RAW) &&
1516 		    !sockopt_ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) {
1517 			ret = -EPERM;
1518 			break;
1519 		}
1520 
1521 		__sock_set_mark(sk, val);
1522 		break;
1523 	case SO_RCVMARK:
1524 		sock_valbool_flag(sk, SOCK_RCVMARK, valbool);
1525 		break;
1526 
1527 	case SO_RCVPRIORITY:
1528 		sock_valbool_flag(sk, SOCK_RCVPRIORITY, valbool);
1529 		break;
1530 
1531 	case SO_RXQ_OVFL:
1532 		sock_valbool_flag(sk, SOCK_RXQ_OVFL, valbool);
1533 		break;
1534 
1535 	case SO_WIFI_STATUS:
1536 		sock_valbool_flag(sk, SOCK_WIFI_STATUS, valbool);
1537 		break;
1538 
1539 	case SO_NOFCS:
1540 		sock_valbool_flag(sk, SOCK_NOFCS, valbool);
1541 		break;
1542 
1543 	case SO_SELECT_ERR_QUEUE:
1544 		sock_valbool_flag(sk, SOCK_SELECT_ERR_QUEUE, valbool);
1545 		break;
1546 
1547 	case SO_PASSCRED:
1548 		if (sk_may_scm_recv(sk))
1549 			sk->sk_scm_credentials = valbool;
1550 		else
1551 			ret = -EOPNOTSUPP;
1552 		break;
1553 
1554 	case SO_PASSSEC:
1555 		if (IS_ENABLED(CONFIG_SECURITY_NETWORK) && sk_may_scm_recv(sk))
1556 			sk->sk_scm_security = valbool;
1557 		else
1558 			ret = -EOPNOTSUPP;
1559 		break;
1560 
1561 	case SO_PASSPIDFD:
1562 		if (sk_is_unix(sk))
1563 			sk->sk_scm_pidfd = valbool;
1564 		else
1565 			ret = -EOPNOTSUPP;
1566 		break;
1567 
1568 	case SO_PASSRIGHTS:
1569 		if (sk_is_unix(sk))
1570 			sk->sk_scm_rights = valbool;
1571 		else
1572 			ret = -EOPNOTSUPP;
1573 		break;
1574 
1575 	case SO_INCOMING_CPU:
1576 		reuseport_update_incoming_cpu(sk, val);
1577 		break;
1578 
1579 	case SO_CNX_ADVICE:
1580 		if (val == 1)
1581 			dst_negative_advice(sk);
1582 		break;
1583 
1584 	case SO_ZEROCOPY:
1585 		if (sk->sk_family == PF_INET || sk->sk_family == PF_INET6) {
1586 			if (!(sk_is_tcp(sk) ||
1587 			      (sk->sk_type == SOCK_DGRAM &&
1588 			       sk->sk_protocol == IPPROTO_UDP)))
1589 				ret = -EOPNOTSUPP;
1590 		} else if (sk->sk_family != PF_RDS) {
1591 			ret = -EOPNOTSUPP;
1592 		}
1593 		if (!ret) {
1594 			if (val < 0 || val > 1)
1595 				ret = -EINVAL;
1596 			else
1597 				sock_valbool_flag(sk, SOCK_ZEROCOPY, valbool);
1598 		}
1599 		break;
1600 
1601 	case SO_TXTIME:
1602 		if (optlen != sizeof(struct sock_txtime)) {
1603 			ret = -EINVAL;
1604 			break;
1605 		} else if (copy_from_sockptr(&sk_txtime, optval,
1606 			   sizeof(struct sock_txtime))) {
1607 			ret = -EFAULT;
1608 			break;
1609 		} else if (sk_txtime.flags & ~SOF_TXTIME_FLAGS_MASK) {
1610 			ret = -EINVAL;
1611 			break;
1612 		}
1613 		/* CLOCK_MONOTONIC is only used by sch_fq, and this packet
1614 		 * scheduler has enough safe guards.
1615 		 */
1616 		if (sk_txtime.clockid != CLOCK_MONOTONIC &&
1617 		    !sockopt_ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) {
1618 			ret = -EPERM;
1619 			break;
1620 		}
1621 
1622 		ret = sockopt_validate_clockid(sk_txtime.clockid);
1623 		if (ret)
1624 			break;
1625 
1626 		sock_valbool_flag(sk, SOCK_TXTIME, true);
1627 		sk->sk_clockid = sk_txtime.clockid;
1628 		sk->sk_txtime_deadline_mode =
1629 			!!(sk_txtime.flags & SOF_TXTIME_DEADLINE_MODE);
1630 		sk->sk_txtime_report_errors =
1631 			!!(sk_txtime.flags & SOF_TXTIME_REPORT_ERRORS);
1632 		break;
1633 
1634 	case SO_BINDTOIFINDEX:
1635 		ret = sock_bindtoindex_locked(sk, val);
1636 		break;
1637 
1638 	case SO_BUF_LOCK:
1639 		if (val & ~SOCK_BUF_LOCK_MASK) {
1640 			ret = -EINVAL;
1641 			break;
1642 		}
1643 		sk->sk_userlocks = val | (sk->sk_userlocks &
1644 					  ~SOCK_BUF_LOCK_MASK);
1645 		break;
1646 
1647 	case SO_RESERVE_MEM:
1648 	{
1649 		int delta;
1650 
1651 		if (val < 0) {
1652 			ret = -EINVAL;
1653 			break;
1654 		}
1655 
1656 		delta = val - sk->sk_reserved_mem;
1657 		if (delta < 0)
1658 			sock_release_reserved_memory(sk, -delta);
1659 		else
1660 			ret = sock_reserve_memory(sk, delta);
1661 		break;
1662 	}
1663 
1664 	default:
1665 		ret = -ENOPROTOOPT;
1666 		break;
1667 	}
1668 	sockopt_release_sock(sk);
1669 	return ret;
1670 }
1671 
sock_setsockopt(struct socket * sock,int level,int optname,sockptr_t optval,unsigned int optlen)1672 int sock_setsockopt(struct socket *sock, int level, int optname,
1673 		    sockptr_t optval, unsigned int optlen)
1674 {
1675 	return sk_setsockopt(sock->sk, level, optname,
1676 			     optval, optlen);
1677 }
1678 EXPORT_SYMBOL(sock_setsockopt);
1679 
sk_get_peer_cred(struct sock * sk)1680 static const struct cred *sk_get_peer_cred(struct sock *sk)
1681 {
1682 	const struct cred *cred;
1683 
1684 	spin_lock(&sk->sk_peer_lock);
1685 	cred = get_cred(sk->sk_peer_cred);
1686 	spin_unlock(&sk->sk_peer_lock);
1687 
1688 	return cred;
1689 }
1690 
cred_to_ucred(struct pid * pid,const struct cred * cred,struct ucred * ucred)1691 static void cred_to_ucred(struct pid *pid, const struct cred *cred,
1692 			  struct ucred *ucred)
1693 {
1694 	ucred->pid = pid_vnr(pid);
1695 	ucred->uid = ucred->gid = -1;
1696 	if (cred) {
1697 		struct user_namespace *current_ns = current_user_ns();
1698 
1699 		ucred->uid = from_kuid_munged(current_ns, cred->euid);
1700 		ucred->gid = from_kgid_munged(current_ns, cred->egid);
1701 	}
1702 }
1703 
groups_to_user(sockptr_t dst,const struct group_info * src)1704 static int groups_to_user(sockptr_t dst, const struct group_info *src)
1705 {
1706 	struct user_namespace *user_ns = current_user_ns();
1707 	int i;
1708 
1709 	for (i = 0; i < src->ngroups; i++) {
1710 		gid_t gid = from_kgid_munged(user_ns, src->gid[i]);
1711 
1712 		if (copy_to_sockptr_offset(dst, i * sizeof(gid), &gid, sizeof(gid)))
1713 			return -EFAULT;
1714 	}
1715 
1716 	return 0;
1717 }
1718 
sk_getsockopt(struct sock * sk,int level,int optname,sockptr_t optval,sockptr_t optlen)1719 int sk_getsockopt(struct sock *sk, int level, int optname,
1720 		  sockptr_t optval, sockptr_t optlen)
1721 {
1722 	struct socket *sock = sk->sk_socket;
1723 
1724 	union {
1725 		int val;
1726 		u64 val64;
1727 		unsigned long ulval;
1728 		struct linger ling;
1729 		struct old_timeval32 tm32;
1730 		struct __kernel_old_timeval tm;
1731 		struct  __kernel_sock_timeval stm;
1732 		struct sock_txtime txtime;
1733 		struct so_timestamping timestamping;
1734 	} v;
1735 
1736 	int lv = sizeof(int);
1737 	int len;
1738 
1739 	if (copy_from_sockptr(&len, optlen, sizeof(int)))
1740 		return -EFAULT;
1741 	if (len < 0)
1742 		return -EINVAL;
1743 
1744 	memset(&v, 0, sizeof(v));
1745 
1746 	switch (optname) {
1747 	case SO_DEBUG:
1748 		v.val = sock_flag(sk, SOCK_DBG);
1749 		break;
1750 
1751 	case SO_DONTROUTE:
1752 		v.val = sock_flag(sk, SOCK_LOCALROUTE);
1753 		break;
1754 
1755 	case SO_BROADCAST:
1756 		v.val = sock_flag(sk, SOCK_BROADCAST);
1757 		break;
1758 
1759 	case SO_SNDBUF:
1760 		v.val = READ_ONCE(sk->sk_sndbuf);
1761 		break;
1762 
1763 	case SO_RCVBUF:
1764 		v.val = READ_ONCE(sk->sk_rcvbuf);
1765 		break;
1766 
1767 	case SO_REUSEADDR:
1768 		v.val = sk->sk_reuse;
1769 		break;
1770 
1771 	case SO_REUSEPORT:
1772 		v.val = sk->sk_reuseport;
1773 		break;
1774 
1775 	case SO_KEEPALIVE:
1776 		v.val = sock_flag(sk, SOCK_KEEPOPEN);
1777 		break;
1778 
1779 	case SO_TYPE:
1780 		v.val = sk->sk_type;
1781 		break;
1782 
1783 	case SO_PROTOCOL:
1784 		v.val = sk->sk_protocol;
1785 		break;
1786 
1787 	case SO_DOMAIN:
1788 		v.val = sk->sk_family;
1789 		break;
1790 
1791 	case SO_ERROR:
1792 		v.val = -sock_error(sk);
1793 		if (v.val == 0)
1794 			v.val = xchg(&sk->sk_err_soft, 0);
1795 		break;
1796 
1797 	case SO_OOBINLINE:
1798 		v.val = sock_flag(sk, SOCK_URGINLINE);
1799 		break;
1800 
1801 	case SO_NO_CHECK:
1802 		v.val = sk->sk_no_check_tx;
1803 		break;
1804 
1805 	case SO_PRIORITY:
1806 		v.val = READ_ONCE(sk->sk_priority);
1807 		break;
1808 
1809 	case SO_LINGER:
1810 		lv		= sizeof(v.ling);
1811 		v.ling.l_onoff	= sock_flag(sk, SOCK_LINGER);
1812 		v.ling.l_linger	= READ_ONCE(sk->sk_lingertime) / HZ;
1813 		break;
1814 
1815 	case SO_BSDCOMPAT:
1816 		break;
1817 
1818 	case SO_TIMESTAMP_OLD:
1819 		v.val = sock_flag(sk, SOCK_RCVTSTAMP) &&
1820 				!sock_flag(sk, SOCK_TSTAMP_NEW) &&
1821 				!sock_flag(sk, SOCK_RCVTSTAMPNS);
1822 		break;
1823 
1824 	case SO_TIMESTAMPNS_OLD:
1825 		v.val = sock_flag(sk, SOCK_RCVTSTAMPNS) && !sock_flag(sk, SOCK_TSTAMP_NEW);
1826 		break;
1827 
1828 	case SO_TIMESTAMP_NEW:
1829 		v.val = sock_flag(sk, SOCK_RCVTSTAMP) && sock_flag(sk, SOCK_TSTAMP_NEW);
1830 		break;
1831 
1832 	case SO_TIMESTAMPNS_NEW:
1833 		v.val = sock_flag(sk, SOCK_RCVTSTAMPNS) && sock_flag(sk, SOCK_TSTAMP_NEW);
1834 		break;
1835 
1836 	case SO_TIMESTAMPING_OLD:
1837 	case SO_TIMESTAMPING_NEW:
1838 		lv = sizeof(v.timestamping);
1839 		/* For the later-added case SO_TIMESTAMPING_NEW: Be strict about only
1840 		 * returning the flags when they were set through the same option.
1841 		 * Don't change the beviour for the old case SO_TIMESTAMPING_OLD.
1842 		 */
1843 		if (optname == SO_TIMESTAMPING_OLD || sock_flag(sk, SOCK_TSTAMP_NEW)) {
1844 			v.timestamping.flags = READ_ONCE(sk->sk_tsflags);
1845 			v.timestamping.bind_phc = READ_ONCE(sk->sk_bind_phc);
1846 		}
1847 		break;
1848 
1849 	case SO_RCVTIMEO_OLD:
1850 	case SO_RCVTIMEO_NEW:
1851 		lv = sock_get_timeout(READ_ONCE(sk->sk_rcvtimeo), &v,
1852 				      SO_RCVTIMEO_OLD == optname);
1853 		break;
1854 
1855 	case SO_SNDTIMEO_OLD:
1856 	case SO_SNDTIMEO_NEW:
1857 		lv = sock_get_timeout(READ_ONCE(sk->sk_sndtimeo), &v,
1858 				      SO_SNDTIMEO_OLD == optname);
1859 		break;
1860 
1861 	case SO_RCVLOWAT:
1862 		v.val = READ_ONCE(sk->sk_rcvlowat);
1863 		break;
1864 
1865 	case SO_SNDLOWAT:
1866 		v.val = 1;
1867 		break;
1868 
1869 	case SO_PASSCRED:
1870 		if (!sk_may_scm_recv(sk))
1871 			return -EOPNOTSUPP;
1872 
1873 		v.val = sk->sk_scm_credentials;
1874 		break;
1875 
1876 	case SO_PASSPIDFD:
1877 		if (!sk_is_unix(sk))
1878 			return -EOPNOTSUPP;
1879 
1880 		v.val = sk->sk_scm_pidfd;
1881 		break;
1882 
1883 	case SO_PASSRIGHTS:
1884 		if (!sk_is_unix(sk))
1885 			return -EOPNOTSUPP;
1886 
1887 		v.val = sk->sk_scm_rights;
1888 		break;
1889 
1890 	case SO_PEERCRED:
1891 	{
1892 		struct ucred peercred;
1893 		if (len > sizeof(peercred))
1894 			len = sizeof(peercred);
1895 
1896 		spin_lock(&sk->sk_peer_lock);
1897 		cred_to_ucred(sk->sk_peer_pid, sk->sk_peer_cred, &peercred);
1898 		spin_unlock(&sk->sk_peer_lock);
1899 
1900 		if (copy_to_sockptr(optval, &peercred, len))
1901 			return -EFAULT;
1902 		goto lenout;
1903 	}
1904 
1905 	case SO_PEERPIDFD:
1906 	{
1907 		struct pid *peer_pid;
1908 		struct file *pidfd_file = NULL;
1909 		unsigned int flags = 0;
1910 		int pidfd;
1911 
1912 		if (len > sizeof(pidfd))
1913 			len = sizeof(pidfd);
1914 
1915 		spin_lock(&sk->sk_peer_lock);
1916 		peer_pid = get_pid(sk->sk_peer_pid);
1917 		spin_unlock(&sk->sk_peer_lock);
1918 
1919 		if (!peer_pid)
1920 			return -ENODATA;
1921 
1922 		/* The use of PIDFD_STALE requires stashing of struct pid
1923 		 * on pidfs with pidfs_register_pid() and only AF_UNIX
1924 		 * were prepared for this.
1925 		 */
1926 		if (sk->sk_family == AF_UNIX)
1927 			flags = PIDFD_STALE;
1928 
1929 		pidfd = pidfd_prepare(peer_pid, flags, &pidfd_file);
1930 		put_pid(peer_pid);
1931 		if (pidfd < 0)
1932 			return pidfd;
1933 
1934 		if (copy_to_sockptr(optval, &pidfd, len) ||
1935 		    copy_to_sockptr(optlen, &len, sizeof(int))) {
1936 			put_unused_fd(pidfd);
1937 			fput(pidfd_file);
1938 
1939 			return -EFAULT;
1940 		}
1941 
1942 		fd_install(pidfd, pidfd_file);
1943 		return 0;
1944 	}
1945 
1946 	case SO_PEERGROUPS:
1947 	{
1948 		const struct cred *cred;
1949 		int ret, n;
1950 
1951 		cred = sk_get_peer_cred(sk);
1952 		if (!cred)
1953 			return -ENODATA;
1954 
1955 		n = cred->group_info->ngroups;
1956 		if (len < n * sizeof(gid_t)) {
1957 			len = n * sizeof(gid_t);
1958 			put_cred(cred);
1959 			return copy_to_sockptr(optlen, &len, sizeof(int)) ? -EFAULT : -ERANGE;
1960 		}
1961 		len = n * sizeof(gid_t);
1962 
1963 		ret = groups_to_user(optval, cred->group_info);
1964 		put_cred(cred);
1965 		if (ret)
1966 			return ret;
1967 		goto lenout;
1968 	}
1969 
1970 	case SO_PEERNAME:
1971 	{
1972 		struct sockaddr_storage address;
1973 
1974 		lv = READ_ONCE(sock->ops)->getname(sock, (struct sockaddr *)&address, 2);
1975 		if (lv < 0)
1976 			return -ENOTCONN;
1977 		if (lv < len)
1978 			return -EINVAL;
1979 		if (copy_to_sockptr(optval, &address, len))
1980 			return -EFAULT;
1981 		goto lenout;
1982 	}
1983 
1984 	/* Dubious BSD thing... Probably nobody even uses it, but
1985 	 * the UNIX standard wants it for whatever reason... -DaveM
1986 	 */
1987 	case SO_ACCEPTCONN:
1988 		v.val = sk->sk_state == TCP_LISTEN;
1989 		break;
1990 
1991 	case SO_PASSSEC:
1992 		if (!IS_ENABLED(CONFIG_SECURITY_NETWORK) || !sk_may_scm_recv(sk))
1993 			return -EOPNOTSUPP;
1994 
1995 		v.val = sk->sk_scm_security;
1996 		break;
1997 
1998 	case SO_PEERSEC:
1999 		return security_socket_getpeersec_stream(sock,
2000 							 optval, optlen, len);
2001 
2002 	case SO_MARK:
2003 		v.val = READ_ONCE(sk->sk_mark);
2004 		break;
2005 
2006 	case SO_RCVMARK:
2007 		v.val = sock_flag(sk, SOCK_RCVMARK);
2008 		break;
2009 
2010 	case SO_RCVPRIORITY:
2011 		v.val = sock_flag(sk, SOCK_RCVPRIORITY);
2012 		break;
2013 
2014 	case SO_RXQ_OVFL:
2015 		v.val = sock_flag(sk, SOCK_RXQ_OVFL);
2016 		break;
2017 
2018 	case SO_WIFI_STATUS:
2019 		v.val = sock_flag(sk, SOCK_WIFI_STATUS);
2020 		break;
2021 
2022 	case SO_PEEK_OFF:
2023 		if (!READ_ONCE(sock->ops)->set_peek_off)
2024 			return -EOPNOTSUPP;
2025 
2026 		v.val = READ_ONCE(sk->sk_peek_off);
2027 		break;
2028 	case SO_NOFCS:
2029 		v.val = sock_flag(sk, SOCK_NOFCS);
2030 		break;
2031 
2032 	case SO_BINDTODEVICE:
2033 		return sock_getbindtodevice(sk, optval, optlen, len);
2034 
2035 	case SO_GET_FILTER:
2036 		len = sk_get_filter(sk, optval, len);
2037 		if (len < 0)
2038 			return len;
2039 
2040 		goto lenout;
2041 
2042 	case SO_LOCK_FILTER:
2043 		v.val = sock_flag(sk, SOCK_FILTER_LOCKED);
2044 		break;
2045 
2046 	case SO_BPF_EXTENSIONS:
2047 		v.val = bpf_tell_extensions();
2048 		break;
2049 
2050 	case SO_SELECT_ERR_QUEUE:
2051 		v.val = sock_flag(sk, SOCK_SELECT_ERR_QUEUE);
2052 		break;
2053 
2054 #ifdef CONFIG_NET_RX_BUSY_POLL
2055 	case SO_BUSY_POLL:
2056 		v.val = READ_ONCE(sk->sk_ll_usec);
2057 		break;
2058 	case SO_PREFER_BUSY_POLL:
2059 		v.val = READ_ONCE(sk->sk_prefer_busy_poll);
2060 		break;
2061 #endif
2062 
2063 	case SO_MAX_PACING_RATE:
2064 		/* The READ_ONCE() pair with the WRITE_ONCE() in sk_setsockopt() */
2065 		if (sizeof(v.ulval) != sizeof(v.val) && len >= sizeof(v.ulval)) {
2066 			lv = sizeof(v.ulval);
2067 			v.ulval = READ_ONCE(sk->sk_max_pacing_rate);
2068 		} else {
2069 			/* 32bit version */
2070 			v.val = min_t(unsigned long, ~0U,
2071 				      READ_ONCE(sk->sk_max_pacing_rate));
2072 		}
2073 		break;
2074 
2075 	case SO_INCOMING_CPU:
2076 		v.val = READ_ONCE(sk->sk_incoming_cpu);
2077 		break;
2078 
2079 	case SO_MEMINFO:
2080 	{
2081 		u32 meminfo[SK_MEMINFO_VARS];
2082 
2083 		sk_get_meminfo(sk, meminfo);
2084 
2085 		len = min_t(unsigned int, len, sizeof(meminfo));
2086 		if (copy_to_sockptr(optval, &meminfo, len))
2087 			return -EFAULT;
2088 
2089 		goto lenout;
2090 	}
2091 
2092 #ifdef CONFIG_NET_RX_BUSY_POLL
2093 	case SO_INCOMING_NAPI_ID:
2094 		v.val = READ_ONCE(sk->sk_napi_id);
2095 
2096 		/* aggregate non-NAPI IDs down to 0 */
2097 		if (!napi_id_valid(v.val))
2098 			v.val = 0;
2099 
2100 		break;
2101 #endif
2102 
2103 	case SO_COOKIE:
2104 		lv = sizeof(u64);
2105 		if (len < lv)
2106 			return -EINVAL;
2107 		v.val64 = sock_gen_cookie(sk);
2108 		break;
2109 
2110 	case SO_ZEROCOPY:
2111 		v.val = sock_flag(sk, SOCK_ZEROCOPY);
2112 		break;
2113 
2114 	case SO_TXTIME:
2115 		lv = sizeof(v.txtime);
2116 		v.txtime.clockid = sk->sk_clockid;
2117 		v.txtime.flags |= sk->sk_txtime_deadline_mode ?
2118 				  SOF_TXTIME_DEADLINE_MODE : 0;
2119 		v.txtime.flags |= sk->sk_txtime_report_errors ?
2120 				  SOF_TXTIME_REPORT_ERRORS : 0;
2121 		break;
2122 
2123 	case SO_BINDTOIFINDEX:
2124 		v.val = READ_ONCE(sk->sk_bound_dev_if);
2125 		break;
2126 
2127 	case SO_NETNS_COOKIE:
2128 		lv = sizeof(u64);
2129 		if (len != lv)
2130 			return -EINVAL;
2131 		v.val64 = sock_net(sk)->net_cookie;
2132 		break;
2133 
2134 	case SO_BUF_LOCK:
2135 		v.val = sk->sk_userlocks & SOCK_BUF_LOCK_MASK;
2136 		break;
2137 
2138 	case SO_RESERVE_MEM:
2139 		v.val = READ_ONCE(sk->sk_reserved_mem);
2140 		break;
2141 
2142 	case SO_TXREHASH:
2143 		if (!sk_is_tcp(sk))
2144 			return -EOPNOTSUPP;
2145 
2146 		/* Paired with WRITE_ONCE() in sk_setsockopt() */
2147 		v.val = READ_ONCE(sk->sk_txrehash);
2148 		break;
2149 
2150 	default:
2151 		/* We implement the SO_SNDLOWAT etc to not be settable
2152 		 * (1003.1g 7).
2153 		 */
2154 		return -ENOPROTOOPT;
2155 	}
2156 
2157 	if (len > lv)
2158 		len = lv;
2159 	if (copy_to_sockptr(optval, &v, len))
2160 		return -EFAULT;
2161 lenout:
2162 	if (copy_to_sockptr(optlen, &len, sizeof(int)))
2163 		return -EFAULT;
2164 	return 0;
2165 }
2166 
2167 /*
2168  * Initialize an sk_lock.
2169  *
2170  * (We also register the sk_lock with the lock validator.)
2171  */
sock_lock_init(struct sock * sk)2172 static inline void sock_lock_init(struct sock *sk)
2173 {
2174 	sk_owner_clear(sk);
2175 
2176 	if (sk->sk_kern_sock)
2177 		sock_lock_init_class_and_name(
2178 			sk,
2179 			af_family_kern_slock_key_strings[sk->sk_family],
2180 			af_family_kern_slock_keys + sk->sk_family,
2181 			af_family_kern_key_strings[sk->sk_family],
2182 			af_family_kern_keys + sk->sk_family);
2183 	else
2184 		sock_lock_init_class_and_name(
2185 			sk,
2186 			af_family_slock_key_strings[sk->sk_family],
2187 			af_family_slock_keys + sk->sk_family,
2188 			af_family_key_strings[sk->sk_family],
2189 			af_family_keys + sk->sk_family);
2190 }
2191 
2192 /*
2193  * Copy all fields from osk to nsk but nsk->sk_refcnt must not change yet,
2194  * even temporarily, because of RCU lookups. sk_node should also be left as is.
2195  * We must not copy fields between sk_dontcopy_begin and sk_dontcopy_end
2196  */
sock_copy(struct sock * nsk,const struct sock * osk)2197 static void sock_copy(struct sock *nsk, const struct sock *osk)
2198 {
2199 	const struct proto *prot = READ_ONCE(osk->sk_prot);
2200 #ifdef CONFIG_SECURITY_NETWORK
2201 	void *sptr = nsk->sk_security;
2202 #endif
2203 
2204 	/* If we move sk_tx_queue_mapping out of the private section,
2205 	 * we must check if sk_tx_queue_clear() is called after
2206 	 * sock_copy() in sk_clone_lock().
2207 	 */
2208 	BUILD_BUG_ON(offsetof(struct sock, sk_tx_queue_mapping) <
2209 		     offsetof(struct sock, sk_dontcopy_begin) ||
2210 		     offsetof(struct sock, sk_tx_queue_mapping) >=
2211 		     offsetof(struct sock, sk_dontcopy_end));
2212 
2213 	memcpy(nsk, osk, offsetof(struct sock, sk_dontcopy_begin));
2214 
2215 	unsafe_memcpy(&nsk->sk_dontcopy_end, &osk->sk_dontcopy_end,
2216 		      prot->obj_size - offsetof(struct sock, sk_dontcopy_end),
2217 		      /* alloc is larger than struct, see sk_prot_alloc() */);
2218 
2219 #ifdef CONFIG_SECURITY_NETWORK
2220 	nsk->sk_security = sptr;
2221 	security_sk_clone(osk, nsk);
2222 #endif
2223 }
2224 
sk_prot_alloc(struct proto * prot,gfp_t priority,int family)2225 static struct sock *sk_prot_alloc(struct proto *prot, gfp_t priority,
2226 		int family)
2227 {
2228 	struct sock *sk;
2229 	struct kmem_cache *slab;
2230 
2231 	slab = prot->slab;
2232 	if (slab != NULL) {
2233 		sk = kmem_cache_alloc(slab, priority & ~__GFP_ZERO);
2234 		if (!sk)
2235 			return sk;
2236 		if (want_init_on_alloc(priority))
2237 			sk_prot_clear_nulls(sk, prot->obj_size);
2238 	} else
2239 		sk = kmalloc(prot->obj_size, priority);
2240 
2241 	if (sk != NULL) {
2242 		if (security_sk_alloc(sk, family, priority))
2243 			goto out_free;
2244 
2245 		if (!try_module_get(prot->owner))
2246 			goto out_free_sec;
2247 	}
2248 
2249 	return sk;
2250 
2251 out_free_sec:
2252 	security_sk_free(sk);
2253 out_free:
2254 	if (slab != NULL)
2255 		kmem_cache_free(slab, sk);
2256 	else
2257 		kfree(sk);
2258 	return NULL;
2259 }
2260 
sk_prot_free(struct proto * prot,struct sock * sk)2261 static void sk_prot_free(struct proto *prot, struct sock *sk)
2262 {
2263 	struct kmem_cache *slab;
2264 	struct module *owner;
2265 
2266 	owner = prot->owner;
2267 	slab = prot->slab;
2268 
2269 	cgroup_sk_free(&sk->sk_cgrp_data);
2270 	mem_cgroup_sk_free(sk);
2271 	security_sk_free(sk);
2272 
2273 	sk_owner_put(sk);
2274 
2275 	if (slab != NULL)
2276 		kmem_cache_free(slab, sk);
2277 	else
2278 		kfree(sk);
2279 	module_put(owner);
2280 }
2281 
2282 /**
2283  *	sk_alloc - All socket objects are allocated here
2284  *	@net: the applicable net namespace
2285  *	@family: protocol family
2286  *	@priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
2287  *	@prot: struct proto associated with this new sock instance
2288  *	@kern: is this to be a kernel socket?
2289  */
sk_alloc(struct net * net,int family,gfp_t priority,struct proto * prot,int kern)2290 struct sock *sk_alloc(struct net *net, int family, gfp_t priority,
2291 		      struct proto *prot, int kern)
2292 {
2293 	struct sock *sk;
2294 
2295 	sk = sk_prot_alloc(prot, priority | __GFP_ZERO, family);
2296 	if (sk) {
2297 		sk->sk_family = family;
2298 		/*
2299 		 * See comment in struct sock definition to understand
2300 		 * why we need sk_prot_creator -acme
2301 		 */
2302 		sk->sk_prot = sk->sk_prot_creator = prot;
2303 		sk->sk_kern_sock = kern;
2304 		sock_lock_init(sk);
2305 		sk->sk_net_refcnt = kern ? 0 : 1;
2306 		if (likely(sk->sk_net_refcnt)) {
2307 			get_net_track(net, &sk->ns_tracker, priority);
2308 			sock_inuse_add(net, 1);
2309 		} else {
2310 			net_passive_inc(net);
2311 			__netns_tracker_alloc(net, &sk->ns_tracker,
2312 					      false, priority);
2313 		}
2314 
2315 		sock_net_set(sk, net);
2316 		refcount_set(&sk->sk_wmem_alloc, 1);
2317 
2318 		mem_cgroup_sk_alloc(sk);
2319 		cgroup_sk_alloc(&sk->sk_cgrp_data);
2320 		sock_update_classid(&sk->sk_cgrp_data);
2321 		sock_update_netprioidx(&sk->sk_cgrp_data);
2322 		sk_tx_queue_clear(sk);
2323 	}
2324 
2325 	return sk;
2326 }
2327 EXPORT_SYMBOL(sk_alloc);
2328 
2329 /* Sockets having SOCK_RCU_FREE will call this function after one RCU
2330  * grace period. This is the case for UDP sockets and TCP listeners.
2331  */
__sk_destruct(struct rcu_head * head)2332 static void __sk_destruct(struct rcu_head *head)
2333 {
2334 	struct sock *sk = container_of(head, struct sock, sk_rcu);
2335 	struct net *net = sock_net(sk);
2336 	struct sk_filter *filter;
2337 
2338 	if (sk->sk_destruct)
2339 		sk->sk_destruct(sk);
2340 
2341 	filter = rcu_dereference_check(sk->sk_filter,
2342 				       refcount_read(&sk->sk_wmem_alloc) == 0);
2343 	if (filter) {
2344 		sk_filter_uncharge(sk, filter);
2345 		RCU_INIT_POINTER(sk->sk_filter, NULL);
2346 	}
2347 
2348 	sock_disable_timestamp(sk, SK_FLAGS_TIMESTAMP);
2349 
2350 #ifdef CONFIG_BPF_SYSCALL
2351 	bpf_sk_storage_free(sk);
2352 #endif
2353 
2354 	if (atomic_read(&sk->sk_omem_alloc))
2355 		pr_debug("%s: optmem leakage (%d bytes) detected\n",
2356 			 __func__, atomic_read(&sk->sk_omem_alloc));
2357 
2358 	if (sk->sk_frag.page) {
2359 		put_page(sk->sk_frag.page);
2360 		sk->sk_frag.page = NULL;
2361 	}
2362 
2363 	/* We do not need to acquire sk->sk_peer_lock, we are the last user. */
2364 	put_cred(sk->sk_peer_cred);
2365 	put_pid(sk->sk_peer_pid);
2366 
2367 	if (likely(sk->sk_net_refcnt)) {
2368 		put_net_track(net, &sk->ns_tracker);
2369 	} else {
2370 		__netns_tracker_free(net, &sk->ns_tracker, false);
2371 		net_passive_dec(net);
2372 	}
2373 	sk_prot_free(sk->sk_prot_creator, sk);
2374 }
2375 
sk_net_refcnt_upgrade(struct sock * sk)2376 void sk_net_refcnt_upgrade(struct sock *sk)
2377 {
2378 	struct net *net = sock_net(sk);
2379 
2380 	WARN_ON_ONCE(sk->sk_net_refcnt);
2381 	__netns_tracker_free(net, &sk->ns_tracker, false);
2382 	net_passive_dec(net);
2383 	sk->sk_net_refcnt = 1;
2384 	get_net_track(net, &sk->ns_tracker, GFP_KERNEL);
2385 	sock_inuse_add(net, 1);
2386 }
2387 EXPORT_SYMBOL_GPL(sk_net_refcnt_upgrade);
2388 
sk_destruct(struct sock * sk)2389 void sk_destruct(struct sock *sk)
2390 {
2391 	bool use_call_rcu = sock_flag(sk, SOCK_RCU_FREE);
2392 
2393 	if (rcu_access_pointer(sk->sk_reuseport_cb)) {
2394 		reuseport_detach_sock(sk);
2395 		use_call_rcu = true;
2396 	}
2397 
2398 	if (use_call_rcu)
2399 		call_rcu(&sk->sk_rcu, __sk_destruct);
2400 	else
2401 		__sk_destruct(&sk->sk_rcu);
2402 }
2403 
__sk_free(struct sock * sk)2404 static void __sk_free(struct sock *sk)
2405 {
2406 	if (likely(sk->sk_net_refcnt))
2407 		sock_inuse_add(sock_net(sk), -1);
2408 
2409 	if (unlikely(sk->sk_net_refcnt && sock_diag_has_destroy_listeners(sk)))
2410 		sock_diag_broadcast_destroy(sk);
2411 	else
2412 		sk_destruct(sk);
2413 }
2414 
sk_free(struct sock * sk)2415 void sk_free(struct sock *sk)
2416 {
2417 	/*
2418 	 * We subtract one from sk_wmem_alloc and can know if
2419 	 * some packets are still in some tx queue.
2420 	 * If not null, sock_wfree() will call __sk_free(sk) later
2421 	 */
2422 	if (refcount_dec_and_test(&sk->sk_wmem_alloc))
2423 		__sk_free(sk);
2424 }
2425 EXPORT_SYMBOL(sk_free);
2426 
sk_init_common(struct sock * sk)2427 static void sk_init_common(struct sock *sk)
2428 {
2429 	skb_queue_head_init(&sk->sk_receive_queue);
2430 	skb_queue_head_init(&sk->sk_write_queue);
2431 	skb_queue_head_init(&sk->sk_error_queue);
2432 
2433 	rwlock_init(&sk->sk_callback_lock);
2434 	lockdep_set_class_and_name(&sk->sk_receive_queue.lock,
2435 			af_rlock_keys + sk->sk_family,
2436 			af_family_rlock_key_strings[sk->sk_family]);
2437 	lockdep_set_class_and_name(&sk->sk_write_queue.lock,
2438 			af_wlock_keys + sk->sk_family,
2439 			af_family_wlock_key_strings[sk->sk_family]);
2440 	lockdep_set_class_and_name(&sk->sk_error_queue.lock,
2441 			af_elock_keys + sk->sk_family,
2442 			af_family_elock_key_strings[sk->sk_family]);
2443 	if (sk->sk_kern_sock)
2444 		lockdep_set_class_and_name(&sk->sk_callback_lock,
2445 			af_kern_callback_keys + sk->sk_family,
2446 			af_family_kern_clock_key_strings[sk->sk_family]);
2447 	else
2448 		lockdep_set_class_and_name(&sk->sk_callback_lock,
2449 			af_callback_keys + sk->sk_family,
2450 			af_family_clock_key_strings[sk->sk_family]);
2451 }
2452 
2453 /**
2454  *	sk_clone_lock - clone a socket, and lock its clone
2455  *	@sk: the socket to clone
2456  *	@priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
2457  *
2458  *	Caller must unlock socket even in error path (bh_unlock_sock(newsk))
2459  */
sk_clone_lock(const struct sock * sk,const gfp_t priority)2460 struct sock *sk_clone_lock(const struct sock *sk, const gfp_t priority)
2461 {
2462 	struct proto *prot = READ_ONCE(sk->sk_prot);
2463 	struct sk_filter *filter;
2464 	bool is_charged = true;
2465 	struct sock *newsk;
2466 
2467 	newsk = sk_prot_alloc(prot, priority, sk->sk_family);
2468 	if (!newsk)
2469 		goto out;
2470 
2471 	sock_copy(newsk, sk);
2472 
2473 	newsk->sk_prot_creator = prot;
2474 
2475 	/* SANITY */
2476 	if (likely(newsk->sk_net_refcnt)) {
2477 		get_net_track(sock_net(newsk), &newsk->ns_tracker, priority);
2478 		sock_inuse_add(sock_net(newsk), 1);
2479 	} else {
2480 		/* Kernel sockets are not elevating the struct net refcount.
2481 		 * Instead, use a tracker to more easily detect if a layer
2482 		 * is not properly dismantling its kernel sockets at netns
2483 		 * destroy time.
2484 		 */
2485 		net_passive_inc(sock_net(newsk));
2486 		__netns_tracker_alloc(sock_net(newsk), &newsk->ns_tracker,
2487 				      false, priority);
2488 	}
2489 	sk_node_init(&newsk->sk_node);
2490 	sock_lock_init(newsk);
2491 	bh_lock_sock(newsk);
2492 	newsk->sk_backlog.head	= newsk->sk_backlog.tail = NULL;
2493 	newsk->sk_backlog.len = 0;
2494 
2495 	atomic_set(&newsk->sk_rmem_alloc, 0);
2496 
2497 	/* sk_wmem_alloc set to one (see sk_free() and sock_wfree()) */
2498 	refcount_set(&newsk->sk_wmem_alloc, 1);
2499 
2500 	atomic_set(&newsk->sk_omem_alloc, 0);
2501 	sk_init_common(newsk);
2502 
2503 	newsk->sk_dst_cache	= NULL;
2504 	newsk->sk_dst_pending_confirm = 0;
2505 	newsk->sk_wmem_queued	= 0;
2506 	newsk->sk_forward_alloc = 0;
2507 	newsk->sk_reserved_mem  = 0;
2508 	atomic_set(&newsk->sk_drops, 0);
2509 	newsk->sk_send_head	= NULL;
2510 	newsk->sk_userlocks	= sk->sk_userlocks & ~SOCK_BINDPORT_LOCK;
2511 	atomic_set(&newsk->sk_zckey, 0);
2512 
2513 	sock_reset_flag(newsk, SOCK_DONE);
2514 
2515 	/* sk->sk_memcg will be populated at accept() time */
2516 	newsk->sk_memcg = NULL;
2517 
2518 	cgroup_sk_clone(&newsk->sk_cgrp_data);
2519 
2520 	rcu_read_lock();
2521 	filter = rcu_dereference(sk->sk_filter);
2522 	if (filter != NULL)
2523 		/* though it's an empty new sock, the charging may fail
2524 		 * if sysctl_optmem_max was changed between creation of
2525 		 * original socket and cloning
2526 		 */
2527 		is_charged = sk_filter_charge(newsk, filter);
2528 	RCU_INIT_POINTER(newsk->sk_filter, filter);
2529 	rcu_read_unlock();
2530 
2531 	if (unlikely(!is_charged || xfrm_sk_clone_policy(newsk, sk))) {
2532 		/* We need to make sure that we don't uncharge the new
2533 		 * socket if we couldn't charge it in the first place
2534 		 * as otherwise we uncharge the parent's filter.
2535 		 */
2536 		if (!is_charged)
2537 			RCU_INIT_POINTER(newsk->sk_filter, NULL);
2538 
2539 		goto free;
2540 	}
2541 
2542 	RCU_INIT_POINTER(newsk->sk_reuseport_cb, NULL);
2543 
2544 	if (bpf_sk_storage_clone(sk, newsk))
2545 		goto free;
2546 
2547 	/* Clear sk_user_data if parent had the pointer tagged
2548 	 * as not suitable for copying when cloning.
2549 	 */
2550 	if (sk_user_data_is_nocopy(newsk))
2551 		newsk->sk_user_data = NULL;
2552 
2553 	newsk->sk_err	   = 0;
2554 	newsk->sk_err_soft = 0;
2555 	newsk->sk_priority = 0;
2556 	newsk->sk_incoming_cpu = raw_smp_processor_id();
2557 
2558 	/* Before updating sk_refcnt, we must commit prior changes to memory
2559 	 * (Documentation/RCU/rculist_nulls.rst for details)
2560 	 */
2561 	smp_wmb();
2562 	refcount_set(&newsk->sk_refcnt, 2);
2563 
2564 	sk_set_socket(newsk, NULL);
2565 	sk_tx_queue_clear(newsk);
2566 	RCU_INIT_POINTER(newsk->sk_wq, NULL);
2567 
2568 	if (newsk->sk_prot->sockets_allocated)
2569 		sk_sockets_allocated_inc(newsk);
2570 
2571 	if (sock_needs_netstamp(sk) && newsk->sk_flags & SK_FLAGS_TIMESTAMP)
2572 		net_enable_timestamp();
2573 out:
2574 	return newsk;
2575 free:
2576 	/* It is still raw copy of parent, so invalidate
2577 	 * destructor and make plain sk_free()
2578 	 */
2579 	newsk->sk_destruct = NULL;
2580 	bh_unlock_sock(newsk);
2581 	sk_free(newsk);
2582 	newsk = NULL;
2583 	goto out;
2584 }
2585 EXPORT_SYMBOL_GPL(sk_clone_lock);
2586 
sk_dst_gso_max_size(struct sock * sk,struct dst_entry * dst)2587 static u32 sk_dst_gso_max_size(struct sock *sk, struct dst_entry *dst)
2588 {
2589 	bool is_ipv6 = false;
2590 	u32 max_size;
2591 
2592 #if IS_ENABLED(CONFIG_IPV6)
2593 	is_ipv6 = (sk->sk_family == AF_INET6 &&
2594 		   !ipv6_addr_v4mapped(&sk->sk_v6_rcv_saddr));
2595 #endif
2596 	/* pairs with the WRITE_ONCE() in netif_set_gso(_ipv4)_max_size() */
2597 	max_size = is_ipv6 ? READ_ONCE(dst_dev(dst)->gso_max_size) :
2598 			READ_ONCE(dst_dev(dst)->gso_ipv4_max_size);
2599 	if (max_size > GSO_LEGACY_MAX_SIZE && !sk_is_tcp(sk))
2600 		max_size = GSO_LEGACY_MAX_SIZE;
2601 
2602 	return max_size - (MAX_TCP_HEADER + 1);
2603 }
2604 
sk_setup_caps(struct sock * sk,struct dst_entry * dst)2605 void sk_setup_caps(struct sock *sk, struct dst_entry *dst)
2606 {
2607 	u32 max_segs = 1;
2608 
2609 	sk->sk_route_caps = dst_dev(dst)->features;
2610 	if (sk_is_tcp(sk)) {
2611 		struct inet_connection_sock *icsk = inet_csk(sk);
2612 
2613 		sk->sk_route_caps |= NETIF_F_GSO;
2614 		icsk->icsk_ack.dst_quick_ack = dst_metric(dst, RTAX_QUICKACK);
2615 	}
2616 	if (sk->sk_route_caps & NETIF_F_GSO)
2617 		sk->sk_route_caps |= NETIF_F_GSO_SOFTWARE;
2618 	if (unlikely(sk->sk_gso_disabled))
2619 		sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
2620 	if (sk_can_gso(sk)) {
2621 		if (dst->header_len && !xfrm_dst_offload_ok(dst)) {
2622 			sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
2623 		} else {
2624 			sk->sk_route_caps |= NETIF_F_SG | NETIF_F_HW_CSUM;
2625 			sk->sk_gso_max_size = sk_dst_gso_max_size(sk, dst);
2626 			/* pairs with the WRITE_ONCE() in netif_set_gso_max_segs() */
2627 			max_segs = max_t(u32, READ_ONCE(dst_dev(dst)->gso_max_segs), 1);
2628 		}
2629 	}
2630 	sk->sk_gso_max_segs = max_segs;
2631 	sk_dst_set(sk, dst);
2632 }
2633 EXPORT_SYMBOL_GPL(sk_setup_caps);
2634 
2635 /*
2636  *	Simple resource managers for sockets.
2637  */
2638 
2639 
2640 /*
2641  * Write buffer destructor automatically called from kfree_skb.
2642  */
sock_wfree(struct sk_buff * skb)2643 void sock_wfree(struct sk_buff *skb)
2644 {
2645 	struct sock *sk = skb->sk;
2646 	unsigned int len = skb->truesize;
2647 	bool free;
2648 
2649 	if (!sock_flag(sk, SOCK_USE_WRITE_QUEUE)) {
2650 		if (sock_flag(sk, SOCK_RCU_FREE) &&
2651 		    sk->sk_write_space == sock_def_write_space) {
2652 			rcu_read_lock();
2653 			free = refcount_sub_and_test(len, &sk->sk_wmem_alloc);
2654 			sock_def_write_space_wfree(sk);
2655 			rcu_read_unlock();
2656 			if (unlikely(free))
2657 				__sk_free(sk);
2658 			return;
2659 		}
2660 
2661 		/*
2662 		 * Keep a reference on sk_wmem_alloc, this will be released
2663 		 * after sk_write_space() call
2664 		 */
2665 		WARN_ON(refcount_sub_and_test(len - 1, &sk->sk_wmem_alloc));
2666 		sk->sk_write_space(sk);
2667 		len = 1;
2668 	}
2669 	/*
2670 	 * if sk_wmem_alloc reaches 0, we must finish what sk_free()
2671 	 * could not do because of in-flight packets
2672 	 */
2673 	if (refcount_sub_and_test(len, &sk->sk_wmem_alloc))
2674 		__sk_free(sk);
2675 }
2676 EXPORT_SYMBOL(sock_wfree);
2677 
2678 /* This variant of sock_wfree() is used by TCP,
2679  * since it sets SOCK_USE_WRITE_QUEUE.
2680  */
__sock_wfree(struct sk_buff * skb)2681 void __sock_wfree(struct sk_buff *skb)
2682 {
2683 	struct sock *sk = skb->sk;
2684 
2685 	if (refcount_sub_and_test(skb->truesize, &sk->sk_wmem_alloc))
2686 		__sk_free(sk);
2687 }
2688 
skb_set_owner_w(struct sk_buff * skb,struct sock * sk)2689 void skb_set_owner_w(struct sk_buff *skb, struct sock *sk)
2690 {
2691 	skb_orphan(skb);
2692 #ifdef CONFIG_INET
2693 	if (unlikely(!sk_fullsock(sk)))
2694 		return skb_set_owner_edemux(skb, sk);
2695 #endif
2696 	skb->sk = sk;
2697 	skb->destructor = sock_wfree;
2698 	skb_set_hash_from_sk(skb, sk);
2699 	/*
2700 	 * We used to take a refcount on sk, but following operation
2701 	 * is enough to guarantee sk_free() won't free this sock until
2702 	 * all in-flight packets are completed
2703 	 */
2704 	refcount_add(skb->truesize, &sk->sk_wmem_alloc);
2705 }
2706 EXPORT_SYMBOL(skb_set_owner_w);
2707 
can_skb_orphan_partial(const struct sk_buff * skb)2708 static bool can_skb_orphan_partial(const struct sk_buff *skb)
2709 {
2710 	/* Drivers depend on in-order delivery for crypto offload,
2711 	 * partial orphan breaks out-of-order-OK logic.
2712 	 */
2713 	if (skb_is_decrypted(skb))
2714 		return false;
2715 
2716 	return (skb->destructor == sock_wfree ||
2717 		(IS_ENABLED(CONFIG_INET) && skb->destructor == tcp_wfree));
2718 }
2719 
2720 /* This helper is used by netem, as it can hold packets in its
2721  * delay queue. We want to allow the owner socket to send more
2722  * packets, as if they were already TX completed by a typical driver.
2723  * But we also want to keep skb->sk set because some packet schedulers
2724  * rely on it (sch_fq for example).
2725  */
skb_orphan_partial(struct sk_buff * skb)2726 void skb_orphan_partial(struct sk_buff *skb)
2727 {
2728 	if (skb_is_tcp_pure_ack(skb))
2729 		return;
2730 
2731 	if (can_skb_orphan_partial(skb) && skb_set_owner_sk_safe(skb, skb->sk))
2732 		return;
2733 
2734 	skb_orphan(skb);
2735 }
2736 EXPORT_SYMBOL(skb_orphan_partial);
2737 
2738 /*
2739  * Read buffer destructor automatically called from kfree_skb.
2740  */
sock_rfree(struct sk_buff * skb)2741 void sock_rfree(struct sk_buff *skb)
2742 {
2743 	struct sock *sk = skb->sk;
2744 	unsigned int len = skb->truesize;
2745 
2746 	atomic_sub(len, &sk->sk_rmem_alloc);
2747 	sk_mem_uncharge(sk, len);
2748 }
2749 EXPORT_SYMBOL(sock_rfree);
2750 
2751 /*
2752  * Buffer destructor for skbs that are not used directly in read or write
2753  * path, e.g. for error handler skbs. Automatically called from kfree_skb.
2754  */
sock_efree(struct sk_buff * skb)2755 void sock_efree(struct sk_buff *skb)
2756 {
2757 	sock_put(skb->sk);
2758 }
2759 EXPORT_SYMBOL(sock_efree);
2760 
2761 /* Buffer destructor for prefetch/receive path where reference count may
2762  * not be held, e.g. for listen sockets.
2763  */
2764 #ifdef CONFIG_INET
sock_pfree(struct sk_buff * skb)2765 void sock_pfree(struct sk_buff *skb)
2766 {
2767 	struct sock *sk = skb->sk;
2768 
2769 	if (!sk_is_refcounted(sk))
2770 		return;
2771 
2772 	if (sk->sk_state == TCP_NEW_SYN_RECV && inet_reqsk(sk)->syncookie) {
2773 		inet_reqsk(sk)->rsk_listener = NULL;
2774 		reqsk_free(inet_reqsk(sk));
2775 		return;
2776 	}
2777 
2778 	sock_gen_put(sk);
2779 }
2780 EXPORT_SYMBOL(sock_pfree);
2781 #endif /* CONFIG_INET */
2782 
__sock_i_ino(struct sock * sk)2783 unsigned long __sock_i_ino(struct sock *sk)
2784 {
2785 	unsigned long ino;
2786 
2787 	read_lock(&sk->sk_callback_lock);
2788 	ino = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_ino : 0;
2789 	read_unlock(&sk->sk_callback_lock);
2790 	return ino;
2791 }
2792 EXPORT_SYMBOL(__sock_i_ino);
2793 
sock_i_ino(struct sock * sk)2794 unsigned long sock_i_ino(struct sock *sk)
2795 {
2796 	unsigned long ino;
2797 
2798 	local_bh_disable();
2799 	ino = __sock_i_ino(sk);
2800 	local_bh_enable();
2801 	return ino;
2802 }
2803 EXPORT_SYMBOL(sock_i_ino);
2804 
2805 /*
2806  * Allocate a skb from the socket's send buffer.
2807  */
sock_wmalloc(struct sock * sk,unsigned long size,int force,gfp_t priority)2808 struct sk_buff *sock_wmalloc(struct sock *sk, unsigned long size, int force,
2809 			     gfp_t priority)
2810 {
2811 	if (force ||
2812 	    refcount_read(&sk->sk_wmem_alloc) < READ_ONCE(sk->sk_sndbuf)) {
2813 		struct sk_buff *skb = alloc_skb(size, priority);
2814 
2815 		if (skb) {
2816 			skb_set_owner_w(skb, sk);
2817 			return skb;
2818 		}
2819 	}
2820 	return NULL;
2821 }
2822 EXPORT_SYMBOL(sock_wmalloc);
2823 
sock_ofree(struct sk_buff * skb)2824 static void sock_ofree(struct sk_buff *skb)
2825 {
2826 	struct sock *sk = skb->sk;
2827 
2828 	atomic_sub(skb->truesize, &sk->sk_omem_alloc);
2829 }
2830 
sock_omalloc(struct sock * sk,unsigned long size,gfp_t priority)2831 struct sk_buff *sock_omalloc(struct sock *sk, unsigned long size,
2832 			     gfp_t priority)
2833 {
2834 	struct sk_buff *skb;
2835 
2836 	/* small safe race: SKB_TRUESIZE may differ from final skb->truesize */
2837 	if (atomic_read(&sk->sk_omem_alloc) + SKB_TRUESIZE(size) >
2838 	    READ_ONCE(sock_net(sk)->core.sysctl_optmem_max))
2839 		return NULL;
2840 
2841 	skb = alloc_skb(size, priority);
2842 	if (!skb)
2843 		return NULL;
2844 
2845 	atomic_add(skb->truesize, &sk->sk_omem_alloc);
2846 	skb->sk = sk;
2847 	skb->destructor = sock_ofree;
2848 	return skb;
2849 }
2850 
2851 /*
2852  * Allocate a memory block from the socket's option memory buffer.
2853  */
sock_kmalloc(struct sock * sk,int size,gfp_t priority)2854 void *sock_kmalloc(struct sock *sk, int size, gfp_t priority)
2855 {
2856 	int optmem_max = READ_ONCE(sock_net(sk)->core.sysctl_optmem_max);
2857 
2858 	if ((unsigned int)size <= optmem_max &&
2859 	    atomic_read(&sk->sk_omem_alloc) + size < optmem_max) {
2860 		void *mem;
2861 		/* First do the add, to avoid the race if kmalloc
2862 		 * might sleep.
2863 		 */
2864 		atomic_add(size, &sk->sk_omem_alloc);
2865 		mem = kmalloc(size, priority);
2866 		if (mem)
2867 			return mem;
2868 		atomic_sub(size, &sk->sk_omem_alloc);
2869 	}
2870 	return NULL;
2871 }
2872 EXPORT_SYMBOL(sock_kmalloc);
2873 
2874 /*
2875  * Duplicate the input "src" memory block using the socket's
2876  * option memory buffer.
2877  */
sock_kmemdup(struct sock * sk,const void * src,int size,gfp_t priority)2878 void *sock_kmemdup(struct sock *sk, const void *src,
2879 		   int size, gfp_t priority)
2880 {
2881 	void *mem;
2882 
2883 	mem = sock_kmalloc(sk, size, priority);
2884 	if (mem)
2885 		memcpy(mem, src, size);
2886 	return mem;
2887 }
2888 EXPORT_SYMBOL(sock_kmemdup);
2889 
2890 /* Free an option memory block. Note, we actually want the inline
2891  * here as this allows gcc to detect the nullify and fold away the
2892  * condition entirely.
2893  */
__sock_kfree_s(struct sock * sk,void * mem,int size,const bool nullify)2894 static inline void __sock_kfree_s(struct sock *sk, void *mem, int size,
2895 				  const bool nullify)
2896 {
2897 	if (WARN_ON_ONCE(!mem))
2898 		return;
2899 	if (nullify)
2900 		kfree_sensitive(mem);
2901 	else
2902 		kfree(mem);
2903 	atomic_sub(size, &sk->sk_omem_alloc);
2904 }
2905 
sock_kfree_s(struct sock * sk,void * mem,int size)2906 void sock_kfree_s(struct sock *sk, void *mem, int size)
2907 {
2908 	__sock_kfree_s(sk, mem, size, false);
2909 }
2910 EXPORT_SYMBOL(sock_kfree_s);
2911 
sock_kzfree_s(struct sock * sk,void * mem,int size)2912 void sock_kzfree_s(struct sock *sk, void *mem, int size)
2913 {
2914 	__sock_kfree_s(sk, mem, size, true);
2915 }
2916 EXPORT_SYMBOL(sock_kzfree_s);
2917 
2918 /* It is almost wait_for_tcp_memory minus release_sock/lock_sock.
2919    I think, these locks should be removed for datagram sockets.
2920  */
sock_wait_for_wmem(struct sock * sk,long timeo)2921 static long sock_wait_for_wmem(struct sock *sk, long timeo)
2922 {
2923 	DEFINE_WAIT(wait);
2924 
2925 	sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
2926 	for (;;) {
2927 		if (!timeo)
2928 			break;
2929 		if (signal_pending(current))
2930 			break;
2931 		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
2932 		prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
2933 		if (refcount_read(&sk->sk_wmem_alloc) < READ_ONCE(sk->sk_sndbuf))
2934 			break;
2935 		if (READ_ONCE(sk->sk_shutdown) & SEND_SHUTDOWN)
2936 			break;
2937 		if (READ_ONCE(sk->sk_err))
2938 			break;
2939 		timeo = schedule_timeout(timeo);
2940 	}
2941 	finish_wait(sk_sleep(sk), &wait);
2942 	return timeo;
2943 }
2944 
2945 
2946 /*
2947  *	Generic send/receive buffer handlers
2948  */
2949 
sock_alloc_send_pskb(struct sock * sk,unsigned long header_len,unsigned long data_len,int noblock,int * errcode,int max_page_order)2950 struct sk_buff *sock_alloc_send_pskb(struct sock *sk, unsigned long header_len,
2951 				     unsigned long data_len, int noblock,
2952 				     int *errcode, int max_page_order)
2953 {
2954 	struct sk_buff *skb;
2955 	long timeo;
2956 	int err;
2957 
2958 	timeo = sock_sndtimeo(sk, noblock);
2959 	for (;;) {
2960 		err = sock_error(sk);
2961 		if (err != 0)
2962 			goto failure;
2963 
2964 		err = -EPIPE;
2965 		if (READ_ONCE(sk->sk_shutdown) & SEND_SHUTDOWN)
2966 			goto failure;
2967 
2968 		if (sk_wmem_alloc_get(sk) < READ_ONCE(sk->sk_sndbuf))
2969 			break;
2970 
2971 		sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
2972 		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
2973 		err = -EAGAIN;
2974 		if (!timeo)
2975 			goto failure;
2976 		if (signal_pending(current))
2977 			goto interrupted;
2978 		timeo = sock_wait_for_wmem(sk, timeo);
2979 	}
2980 	skb = alloc_skb_with_frags(header_len, data_len, max_page_order,
2981 				   errcode, sk->sk_allocation);
2982 	if (skb)
2983 		skb_set_owner_w(skb, sk);
2984 	return skb;
2985 
2986 interrupted:
2987 	err = sock_intr_errno(timeo);
2988 failure:
2989 	*errcode = err;
2990 	return NULL;
2991 }
2992 EXPORT_SYMBOL(sock_alloc_send_pskb);
2993 
__sock_cmsg_send(struct sock * sk,struct cmsghdr * cmsg,struct sockcm_cookie * sockc)2994 int __sock_cmsg_send(struct sock *sk, struct cmsghdr *cmsg,
2995 		     struct sockcm_cookie *sockc)
2996 {
2997 	u32 tsflags;
2998 
2999 	BUILD_BUG_ON(SOF_TIMESTAMPING_LAST == (1 << 31));
3000 
3001 	switch (cmsg->cmsg_type) {
3002 	case SO_MARK:
3003 		if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_RAW) &&
3004 		    !ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
3005 			return -EPERM;
3006 		if (cmsg->cmsg_len != CMSG_LEN(sizeof(u32)))
3007 			return -EINVAL;
3008 		sockc->mark = *(u32 *)CMSG_DATA(cmsg);
3009 		break;
3010 	case SO_TIMESTAMPING_OLD:
3011 	case SO_TIMESTAMPING_NEW:
3012 		if (cmsg->cmsg_len != CMSG_LEN(sizeof(u32)))
3013 			return -EINVAL;
3014 
3015 		tsflags = *(u32 *)CMSG_DATA(cmsg);
3016 		if (tsflags & ~SOF_TIMESTAMPING_TX_RECORD_MASK)
3017 			return -EINVAL;
3018 
3019 		sockc->tsflags &= ~SOF_TIMESTAMPING_TX_RECORD_MASK;
3020 		sockc->tsflags |= tsflags;
3021 		break;
3022 	case SCM_TXTIME:
3023 		if (!sock_flag(sk, SOCK_TXTIME))
3024 			return -EINVAL;
3025 		if (cmsg->cmsg_len != CMSG_LEN(sizeof(u64)))
3026 			return -EINVAL;
3027 		sockc->transmit_time = get_unaligned((u64 *)CMSG_DATA(cmsg));
3028 		break;
3029 	case SCM_TS_OPT_ID:
3030 		if (sk_is_tcp(sk))
3031 			return -EINVAL;
3032 		tsflags = READ_ONCE(sk->sk_tsflags);
3033 		if (!(tsflags & SOF_TIMESTAMPING_OPT_ID))
3034 			return -EINVAL;
3035 		if (cmsg->cmsg_len != CMSG_LEN(sizeof(u32)))
3036 			return -EINVAL;
3037 		sockc->ts_opt_id = *(u32 *)CMSG_DATA(cmsg);
3038 		sockc->tsflags |= SOCKCM_FLAG_TS_OPT_ID;
3039 		break;
3040 	/* SCM_RIGHTS and SCM_CREDENTIALS are semantically in SOL_UNIX. */
3041 	case SCM_RIGHTS:
3042 	case SCM_CREDENTIALS:
3043 		break;
3044 	case SO_PRIORITY:
3045 		if (cmsg->cmsg_len != CMSG_LEN(sizeof(u32)))
3046 			return -EINVAL;
3047 		if (!sk_set_prio_allowed(sk, *(u32 *)CMSG_DATA(cmsg)))
3048 			return -EPERM;
3049 		sockc->priority = *(u32 *)CMSG_DATA(cmsg);
3050 		break;
3051 	case SCM_DEVMEM_DMABUF:
3052 		if (cmsg->cmsg_len != CMSG_LEN(sizeof(u32)))
3053 			return -EINVAL;
3054 		sockc->dmabuf_id = *(u32 *)CMSG_DATA(cmsg);
3055 		break;
3056 	default:
3057 		return -EINVAL;
3058 	}
3059 	return 0;
3060 }
3061 EXPORT_SYMBOL(__sock_cmsg_send);
3062 
sock_cmsg_send(struct sock * sk,struct msghdr * msg,struct sockcm_cookie * sockc)3063 int sock_cmsg_send(struct sock *sk, struct msghdr *msg,
3064 		   struct sockcm_cookie *sockc)
3065 {
3066 	struct cmsghdr *cmsg;
3067 	int ret;
3068 
3069 	for_each_cmsghdr(cmsg, msg) {
3070 		if (!CMSG_OK(msg, cmsg))
3071 			return -EINVAL;
3072 		if (cmsg->cmsg_level != SOL_SOCKET)
3073 			continue;
3074 		ret = __sock_cmsg_send(sk, cmsg, sockc);
3075 		if (ret)
3076 			return ret;
3077 	}
3078 	return 0;
3079 }
3080 EXPORT_SYMBOL(sock_cmsg_send);
3081 
sk_enter_memory_pressure(struct sock * sk)3082 static void sk_enter_memory_pressure(struct sock *sk)
3083 {
3084 	if (!sk->sk_prot->enter_memory_pressure)
3085 		return;
3086 
3087 	sk->sk_prot->enter_memory_pressure(sk);
3088 }
3089 
sk_leave_memory_pressure(struct sock * sk)3090 static void sk_leave_memory_pressure(struct sock *sk)
3091 {
3092 	if (sk->sk_prot->leave_memory_pressure) {
3093 		INDIRECT_CALL_INET_1(sk->sk_prot->leave_memory_pressure,
3094 				     tcp_leave_memory_pressure, sk);
3095 	} else {
3096 		unsigned long *memory_pressure = sk->sk_prot->memory_pressure;
3097 
3098 		if (memory_pressure && READ_ONCE(*memory_pressure))
3099 			WRITE_ONCE(*memory_pressure, 0);
3100 	}
3101 }
3102 
3103 DEFINE_STATIC_KEY_FALSE(net_high_order_alloc_disable_key);
3104 
3105 /**
3106  * skb_page_frag_refill - check that a page_frag contains enough room
3107  * @sz: minimum size of the fragment we want to get
3108  * @pfrag: pointer to page_frag
3109  * @gfp: priority for memory allocation
3110  *
3111  * Note: While this allocator tries to use high order pages, there is
3112  * no guarantee that allocations succeed. Therefore, @sz MUST be
3113  * less or equal than PAGE_SIZE.
3114  */
skb_page_frag_refill(unsigned int sz,struct page_frag * pfrag,gfp_t gfp)3115 bool skb_page_frag_refill(unsigned int sz, struct page_frag *pfrag, gfp_t gfp)
3116 {
3117 	if (pfrag->page) {
3118 		if (page_ref_count(pfrag->page) == 1) {
3119 			pfrag->offset = 0;
3120 			return true;
3121 		}
3122 		if (pfrag->offset + sz <= pfrag->size)
3123 			return true;
3124 		put_page(pfrag->page);
3125 	}
3126 
3127 	pfrag->offset = 0;
3128 	if (SKB_FRAG_PAGE_ORDER &&
3129 	    !static_branch_unlikely(&net_high_order_alloc_disable_key)) {
3130 		/* Avoid direct reclaim but allow kswapd to wake */
3131 		pfrag->page = alloc_pages((gfp & ~__GFP_DIRECT_RECLAIM) |
3132 					  __GFP_COMP | __GFP_NOWARN |
3133 					  __GFP_NORETRY,
3134 					  SKB_FRAG_PAGE_ORDER);
3135 		if (likely(pfrag->page)) {
3136 			pfrag->size = PAGE_SIZE << SKB_FRAG_PAGE_ORDER;
3137 			return true;
3138 		}
3139 	}
3140 	pfrag->page = alloc_page(gfp);
3141 	if (likely(pfrag->page)) {
3142 		pfrag->size = PAGE_SIZE;
3143 		return true;
3144 	}
3145 	return false;
3146 }
3147 EXPORT_SYMBOL(skb_page_frag_refill);
3148 
sk_page_frag_refill(struct sock * sk,struct page_frag * pfrag)3149 bool sk_page_frag_refill(struct sock *sk, struct page_frag *pfrag)
3150 {
3151 	if (likely(skb_page_frag_refill(32U, pfrag, sk->sk_allocation)))
3152 		return true;
3153 
3154 	sk_enter_memory_pressure(sk);
3155 	sk_stream_moderate_sndbuf(sk);
3156 	return false;
3157 }
3158 EXPORT_SYMBOL(sk_page_frag_refill);
3159 
__lock_sock(struct sock * sk)3160 void __lock_sock(struct sock *sk)
3161 	__releases(&sk->sk_lock.slock)
3162 	__acquires(&sk->sk_lock.slock)
3163 {
3164 	DEFINE_WAIT(wait);
3165 
3166 	for (;;) {
3167 		prepare_to_wait_exclusive(&sk->sk_lock.wq, &wait,
3168 					TASK_UNINTERRUPTIBLE);
3169 		spin_unlock_bh(&sk->sk_lock.slock);
3170 		schedule();
3171 		spin_lock_bh(&sk->sk_lock.slock);
3172 		if (!sock_owned_by_user(sk))
3173 			break;
3174 	}
3175 	finish_wait(&sk->sk_lock.wq, &wait);
3176 }
3177 
__release_sock(struct sock * sk)3178 void __release_sock(struct sock *sk)
3179 	__releases(&sk->sk_lock.slock)
3180 	__acquires(&sk->sk_lock.slock)
3181 {
3182 	struct sk_buff *skb, *next;
3183 
3184 	while ((skb = sk->sk_backlog.head) != NULL) {
3185 		sk->sk_backlog.head = sk->sk_backlog.tail = NULL;
3186 
3187 		spin_unlock_bh(&sk->sk_lock.slock);
3188 
3189 		do {
3190 			next = skb->next;
3191 			prefetch(next);
3192 			DEBUG_NET_WARN_ON_ONCE(skb_dst_is_noref(skb));
3193 			skb_mark_not_on_list(skb);
3194 			sk_backlog_rcv(sk, skb);
3195 
3196 			cond_resched();
3197 
3198 			skb = next;
3199 		} while (skb != NULL);
3200 
3201 		spin_lock_bh(&sk->sk_lock.slock);
3202 	}
3203 
3204 	/*
3205 	 * Doing the zeroing here guarantee we can not loop forever
3206 	 * while a wild producer attempts to flood us.
3207 	 */
3208 	sk->sk_backlog.len = 0;
3209 }
3210 
__sk_flush_backlog(struct sock * sk)3211 void __sk_flush_backlog(struct sock *sk)
3212 {
3213 	spin_lock_bh(&sk->sk_lock.slock);
3214 	__release_sock(sk);
3215 
3216 	if (sk->sk_prot->release_cb)
3217 		INDIRECT_CALL_INET_1(sk->sk_prot->release_cb,
3218 				     tcp_release_cb, sk);
3219 
3220 	spin_unlock_bh(&sk->sk_lock.slock);
3221 }
3222 EXPORT_SYMBOL_GPL(__sk_flush_backlog);
3223 
3224 /**
3225  * sk_wait_data - wait for data to arrive at sk_receive_queue
3226  * @sk:    sock to wait on
3227  * @timeo: for how long
3228  * @skb:   last skb seen on sk_receive_queue
3229  *
3230  * Now socket state including sk->sk_err is changed only under lock,
3231  * hence we may omit checks after joining wait queue.
3232  * We check receive queue before schedule() only as optimization;
3233  * it is very likely that release_sock() added new data.
3234  */
sk_wait_data(struct sock * sk,long * timeo,const struct sk_buff * skb)3235 int sk_wait_data(struct sock *sk, long *timeo, const struct sk_buff *skb)
3236 {
3237 	DEFINE_WAIT_FUNC(wait, woken_wake_function);
3238 	int rc;
3239 
3240 	add_wait_queue(sk_sleep(sk), &wait);
3241 	sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
3242 	rc = sk_wait_event(sk, timeo, skb_peek_tail(&sk->sk_receive_queue) != skb, &wait);
3243 	sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
3244 	remove_wait_queue(sk_sleep(sk), &wait);
3245 	return rc;
3246 }
3247 EXPORT_SYMBOL(sk_wait_data);
3248 
3249 /**
3250  *	__sk_mem_raise_allocated - increase memory_allocated
3251  *	@sk: socket
3252  *	@size: memory size to allocate
3253  *	@amt: pages to allocate
3254  *	@kind: allocation type
3255  *
3256  *	Similar to __sk_mem_schedule(), but does not update sk_forward_alloc.
3257  *
3258  *	Unlike the globally shared limits among the sockets under same protocol,
3259  *	consuming the budget of a memcg won't have direct effect on other ones.
3260  *	So be optimistic about memcg's tolerance, and leave the callers to decide
3261  *	whether or not to raise allocated through sk_under_memory_pressure() or
3262  *	its variants.
3263  */
__sk_mem_raise_allocated(struct sock * sk,int size,int amt,int kind)3264 int __sk_mem_raise_allocated(struct sock *sk, int size, int amt, int kind)
3265 {
3266 	struct mem_cgroup *memcg = mem_cgroup_sockets_enabled ? sk->sk_memcg : NULL;
3267 	struct proto *prot = sk->sk_prot;
3268 	bool charged = true;
3269 	long allocated;
3270 
3271 	sk_memory_allocated_add(sk, amt);
3272 	allocated = sk_memory_allocated(sk);
3273 
3274 	if (memcg) {
3275 		charged = mem_cgroup_charge_skmem(memcg, amt, gfp_memcg_charge());
3276 		if (!charged)
3277 			goto suppress_allocation;
3278 	}
3279 
3280 	/* Under limit. */
3281 	if (allocated <= sk_prot_mem_limits(sk, 0)) {
3282 		sk_leave_memory_pressure(sk);
3283 		return 1;
3284 	}
3285 
3286 	/* Under pressure. */
3287 	if (allocated > sk_prot_mem_limits(sk, 1))
3288 		sk_enter_memory_pressure(sk);
3289 
3290 	/* Over hard limit. */
3291 	if (allocated > sk_prot_mem_limits(sk, 2))
3292 		goto suppress_allocation;
3293 
3294 	/* Guarantee minimum buffer size under pressure (either global
3295 	 * or memcg) to make sure features described in RFC 7323 (TCP
3296 	 * Extensions for High Performance) work properly.
3297 	 *
3298 	 * This rule does NOT stand when exceeds global or memcg's hard
3299 	 * limit, or else a DoS attack can be taken place by spawning
3300 	 * lots of sockets whose usage are under minimum buffer size.
3301 	 */
3302 	if (kind == SK_MEM_RECV) {
3303 		if (atomic_read(&sk->sk_rmem_alloc) < sk_get_rmem0(sk, prot))
3304 			return 1;
3305 
3306 	} else { /* SK_MEM_SEND */
3307 		int wmem0 = sk_get_wmem0(sk, prot);
3308 
3309 		if (sk->sk_type == SOCK_STREAM) {
3310 			if (sk->sk_wmem_queued < wmem0)
3311 				return 1;
3312 		} else if (refcount_read(&sk->sk_wmem_alloc) < wmem0) {
3313 				return 1;
3314 		}
3315 	}
3316 
3317 	if (sk_has_memory_pressure(sk)) {
3318 		u64 alloc;
3319 
3320 		/* The following 'average' heuristic is within the
3321 		 * scope of global accounting, so it only makes
3322 		 * sense for global memory pressure.
3323 		 */
3324 		if (!sk_under_global_memory_pressure(sk))
3325 			return 1;
3326 
3327 		/* Try to be fair among all the sockets under global
3328 		 * pressure by allowing the ones that below average
3329 		 * usage to raise.
3330 		 */
3331 		alloc = sk_sockets_allocated_read_positive(sk);
3332 		if (sk_prot_mem_limits(sk, 2) > alloc *
3333 		    sk_mem_pages(sk->sk_wmem_queued +
3334 				 atomic_read(&sk->sk_rmem_alloc) +
3335 				 sk->sk_forward_alloc))
3336 			return 1;
3337 	}
3338 
3339 suppress_allocation:
3340 
3341 	if (kind == SK_MEM_SEND && sk->sk_type == SOCK_STREAM) {
3342 		sk_stream_moderate_sndbuf(sk);
3343 
3344 		/* Fail only if socket is _under_ its sndbuf.
3345 		 * In this case we cannot block, so that we have to fail.
3346 		 */
3347 		if (sk->sk_wmem_queued + size >= sk->sk_sndbuf) {
3348 			/* Force charge with __GFP_NOFAIL */
3349 			if (memcg && !charged) {
3350 				mem_cgroup_charge_skmem(memcg, amt,
3351 					gfp_memcg_charge() | __GFP_NOFAIL);
3352 			}
3353 			return 1;
3354 		}
3355 	}
3356 
3357 	if (kind == SK_MEM_SEND || (kind == SK_MEM_RECV && charged))
3358 		trace_sock_exceed_buf_limit(sk, prot, allocated, kind);
3359 
3360 	sk_memory_allocated_sub(sk, amt);
3361 
3362 	if (memcg && charged)
3363 		mem_cgroup_uncharge_skmem(memcg, amt);
3364 
3365 	return 0;
3366 }
3367 
3368 /**
3369  *	__sk_mem_schedule - increase sk_forward_alloc and memory_allocated
3370  *	@sk: socket
3371  *	@size: memory size to allocate
3372  *	@kind: allocation type
3373  *
3374  *	If kind is SK_MEM_SEND, it means wmem allocation. Otherwise it means
3375  *	rmem allocation. This function assumes that protocols which have
3376  *	memory_pressure use sk_wmem_queued as write buffer accounting.
3377  */
__sk_mem_schedule(struct sock * sk,int size,int kind)3378 int __sk_mem_schedule(struct sock *sk, int size, int kind)
3379 {
3380 	int ret, amt = sk_mem_pages(size);
3381 
3382 	sk_forward_alloc_add(sk, amt << PAGE_SHIFT);
3383 	ret = __sk_mem_raise_allocated(sk, size, amt, kind);
3384 	if (!ret)
3385 		sk_forward_alloc_add(sk, -(amt << PAGE_SHIFT));
3386 	return ret;
3387 }
3388 EXPORT_SYMBOL(__sk_mem_schedule);
3389 
3390 /**
3391  *	__sk_mem_reduce_allocated - reclaim memory_allocated
3392  *	@sk: socket
3393  *	@amount: number of quanta
3394  *
3395  *	Similar to __sk_mem_reclaim(), but does not update sk_forward_alloc
3396  */
__sk_mem_reduce_allocated(struct sock * sk,int amount)3397 void __sk_mem_reduce_allocated(struct sock *sk, int amount)
3398 {
3399 	sk_memory_allocated_sub(sk, amount);
3400 
3401 	if (mem_cgroup_sockets_enabled && sk->sk_memcg)
3402 		mem_cgroup_uncharge_skmem(sk->sk_memcg, amount);
3403 
3404 	if (sk_under_global_memory_pressure(sk) &&
3405 	    (sk_memory_allocated(sk) < sk_prot_mem_limits(sk, 0)))
3406 		sk_leave_memory_pressure(sk);
3407 }
3408 
3409 /**
3410  *	__sk_mem_reclaim - reclaim sk_forward_alloc and memory_allocated
3411  *	@sk: socket
3412  *	@amount: number of bytes (rounded down to a PAGE_SIZE multiple)
3413  */
__sk_mem_reclaim(struct sock * sk,int amount)3414 void __sk_mem_reclaim(struct sock *sk, int amount)
3415 {
3416 	amount >>= PAGE_SHIFT;
3417 	sk_forward_alloc_add(sk, -(amount << PAGE_SHIFT));
3418 	__sk_mem_reduce_allocated(sk, amount);
3419 }
3420 EXPORT_SYMBOL(__sk_mem_reclaim);
3421 
sk_set_peek_off(struct sock * sk,int val)3422 int sk_set_peek_off(struct sock *sk, int val)
3423 {
3424 	WRITE_ONCE(sk->sk_peek_off, val);
3425 	return 0;
3426 }
3427 EXPORT_SYMBOL_GPL(sk_set_peek_off);
3428 
3429 /*
3430  * Set of default routines for initialising struct proto_ops when
3431  * the protocol does not support a particular function. In certain
3432  * cases where it makes no sense for a protocol to have a "do nothing"
3433  * function, some default processing is provided.
3434  */
3435 
sock_no_bind(struct socket * sock,struct sockaddr * saddr,int len)3436 int sock_no_bind(struct socket *sock, struct sockaddr *saddr, int len)
3437 {
3438 	return -EOPNOTSUPP;
3439 }
3440 EXPORT_SYMBOL(sock_no_bind);
3441 
sock_no_connect(struct socket * sock,struct sockaddr * saddr,int len,int flags)3442 int sock_no_connect(struct socket *sock, struct sockaddr *saddr,
3443 		    int len, int flags)
3444 {
3445 	return -EOPNOTSUPP;
3446 }
3447 EXPORT_SYMBOL(sock_no_connect);
3448 
sock_no_socketpair(struct socket * sock1,struct socket * sock2)3449 int sock_no_socketpair(struct socket *sock1, struct socket *sock2)
3450 {
3451 	return -EOPNOTSUPP;
3452 }
3453 EXPORT_SYMBOL(sock_no_socketpair);
3454 
sock_no_accept(struct socket * sock,struct socket * newsock,struct proto_accept_arg * arg)3455 int sock_no_accept(struct socket *sock, struct socket *newsock,
3456 		   struct proto_accept_arg *arg)
3457 {
3458 	return -EOPNOTSUPP;
3459 }
3460 EXPORT_SYMBOL(sock_no_accept);
3461 
sock_no_getname(struct socket * sock,struct sockaddr * saddr,int peer)3462 int sock_no_getname(struct socket *sock, struct sockaddr *saddr,
3463 		    int peer)
3464 {
3465 	return -EOPNOTSUPP;
3466 }
3467 EXPORT_SYMBOL(sock_no_getname);
3468 
sock_no_ioctl(struct socket * sock,unsigned int cmd,unsigned long arg)3469 int sock_no_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
3470 {
3471 	return -EOPNOTSUPP;
3472 }
3473 EXPORT_SYMBOL(sock_no_ioctl);
3474 
sock_no_listen(struct socket * sock,int backlog)3475 int sock_no_listen(struct socket *sock, int backlog)
3476 {
3477 	return -EOPNOTSUPP;
3478 }
3479 EXPORT_SYMBOL(sock_no_listen);
3480 
sock_no_shutdown(struct socket * sock,int how)3481 int sock_no_shutdown(struct socket *sock, int how)
3482 {
3483 	return -EOPNOTSUPP;
3484 }
3485 EXPORT_SYMBOL(sock_no_shutdown);
3486 
sock_no_sendmsg(struct socket * sock,struct msghdr * m,size_t len)3487 int sock_no_sendmsg(struct socket *sock, struct msghdr *m, size_t len)
3488 {
3489 	return -EOPNOTSUPP;
3490 }
3491 EXPORT_SYMBOL(sock_no_sendmsg);
3492 
sock_no_sendmsg_locked(struct sock * sk,struct msghdr * m,size_t len)3493 int sock_no_sendmsg_locked(struct sock *sk, struct msghdr *m, size_t len)
3494 {
3495 	return -EOPNOTSUPP;
3496 }
3497 EXPORT_SYMBOL(sock_no_sendmsg_locked);
3498 
sock_no_recvmsg(struct socket * sock,struct msghdr * m,size_t len,int flags)3499 int sock_no_recvmsg(struct socket *sock, struct msghdr *m, size_t len,
3500 		    int flags)
3501 {
3502 	return -EOPNOTSUPP;
3503 }
3504 EXPORT_SYMBOL(sock_no_recvmsg);
3505 
sock_no_mmap(struct file * file,struct socket * sock,struct vm_area_struct * vma)3506 int sock_no_mmap(struct file *file, struct socket *sock, struct vm_area_struct *vma)
3507 {
3508 	/* Mirror missing mmap method error code */
3509 	return -ENODEV;
3510 }
3511 EXPORT_SYMBOL(sock_no_mmap);
3512 
3513 /*
3514  * When a file is received (via SCM_RIGHTS, etc), we must bump the
3515  * various sock-based usage counts.
3516  */
__receive_sock(struct file * file)3517 void __receive_sock(struct file *file)
3518 {
3519 	struct socket *sock;
3520 
3521 	sock = sock_from_file(file);
3522 	if (sock) {
3523 		sock_update_netprioidx(&sock->sk->sk_cgrp_data);
3524 		sock_update_classid(&sock->sk->sk_cgrp_data);
3525 	}
3526 }
3527 
3528 /*
3529  *	Default Socket Callbacks
3530  */
3531 
sock_def_wakeup(struct sock * sk)3532 static void sock_def_wakeup(struct sock *sk)
3533 {
3534 	struct socket_wq *wq;
3535 
3536 	rcu_read_lock();
3537 	wq = rcu_dereference(sk->sk_wq);
3538 	if (skwq_has_sleeper(wq))
3539 		wake_up_interruptible_all(&wq->wait);
3540 	rcu_read_unlock();
3541 }
3542 
sock_def_error_report(struct sock * sk)3543 static void sock_def_error_report(struct sock *sk)
3544 {
3545 	struct socket_wq *wq;
3546 
3547 	rcu_read_lock();
3548 	wq = rcu_dereference(sk->sk_wq);
3549 	if (skwq_has_sleeper(wq))
3550 		wake_up_interruptible_poll(&wq->wait, EPOLLERR);
3551 	sk_wake_async_rcu(sk, SOCK_WAKE_IO, POLL_ERR);
3552 	rcu_read_unlock();
3553 }
3554 
sock_def_readable(struct sock * sk)3555 void sock_def_readable(struct sock *sk)
3556 {
3557 	struct socket_wq *wq;
3558 
3559 	trace_sk_data_ready(sk);
3560 
3561 	rcu_read_lock();
3562 	wq = rcu_dereference(sk->sk_wq);
3563 	if (skwq_has_sleeper(wq))
3564 		wake_up_interruptible_sync_poll(&wq->wait, EPOLLIN | EPOLLPRI |
3565 						EPOLLRDNORM | EPOLLRDBAND);
3566 	sk_wake_async_rcu(sk, SOCK_WAKE_WAITD, POLL_IN);
3567 	rcu_read_unlock();
3568 }
3569 
sock_def_write_space(struct sock * sk)3570 static void sock_def_write_space(struct sock *sk)
3571 {
3572 	struct socket_wq *wq;
3573 
3574 	rcu_read_lock();
3575 
3576 	/* Do not wake up a writer until he can make "significant"
3577 	 * progress.  --DaveM
3578 	 */
3579 	if (sock_writeable(sk)) {
3580 		wq = rcu_dereference(sk->sk_wq);
3581 		if (skwq_has_sleeper(wq))
3582 			wake_up_interruptible_sync_poll(&wq->wait, EPOLLOUT |
3583 						EPOLLWRNORM | EPOLLWRBAND);
3584 
3585 		/* Should agree with poll, otherwise some programs break */
3586 		sk_wake_async_rcu(sk, SOCK_WAKE_SPACE, POLL_OUT);
3587 	}
3588 
3589 	rcu_read_unlock();
3590 }
3591 
3592 /* An optimised version of sock_def_write_space(), should only be called
3593  * for SOCK_RCU_FREE sockets under RCU read section and after putting
3594  * ->sk_wmem_alloc.
3595  */
sock_def_write_space_wfree(struct sock * sk)3596 static void sock_def_write_space_wfree(struct sock *sk)
3597 {
3598 	/* Do not wake up a writer until he can make "significant"
3599 	 * progress.  --DaveM
3600 	 */
3601 	if (sock_writeable(sk)) {
3602 		struct socket_wq *wq = rcu_dereference(sk->sk_wq);
3603 
3604 		/* rely on refcount_sub from sock_wfree() */
3605 		smp_mb__after_atomic();
3606 		if (wq && waitqueue_active(&wq->wait))
3607 			wake_up_interruptible_sync_poll(&wq->wait, EPOLLOUT |
3608 						EPOLLWRNORM | EPOLLWRBAND);
3609 
3610 		/* Should agree with poll, otherwise some programs break */
3611 		sk_wake_async_rcu(sk, SOCK_WAKE_SPACE, POLL_OUT);
3612 	}
3613 }
3614 
sock_def_destruct(struct sock * sk)3615 static void sock_def_destruct(struct sock *sk)
3616 {
3617 }
3618 
sk_send_sigurg(struct sock * sk)3619 void sk_send_sigurg(struct sock *sk)
3620 {
3621 	if (sk->sk_socket && sk->sk_socket->file)
3622 		if (send_sigurg(sk->sk_socket->file))
3623 			sk_wake_async(sk, SOCK_WAKE_URG, POLL_PRI);
3624 }
3625 EXPORT_SYMBOL(sk_send_sigurg);
3626 
sk_reset_timer(struct sock * sk,struct timer_list * timer,unsigned long expires)3627 void sk_reset_timer(struct sock *sk, struct timer_list* timer,
3628 		    unsigned long expires)
3629 {
3630 	if (!mod_timer(timer, expires))
3631 		sock_hold(sk);
3632 }
3633 EXPORT_SYMBOL(sk_reset_timer);
3634 
sk_stop_timer(struct sock * sk,struct timer_list * timer)3635 void sk_stop_timer(struct sock *sk, struct timer_list* timer)
3636 {
3637 	if (timer_delete(timer))
3638 		__sock_put(sk);
3639 }
3640 EXPORT_SYMBOL(sk_stop_timer);
3641 
sk_stop_timer_sync(struct sock * sk,struct timer_list * timer)3642 void sk_stop_timer_sync(struct sock *sk, struct timer_list *timer)
3643 {
3644 	if (timer_delete_sync(timer))
3645 		__sock_put(sk);
3646 }
3647 EXPORT_SYMBOL(sk_stop_timer_sync);
3648 
sock_init_data_uid(struct socket * sock,struct sock * sk,kuid_t uid)3649 void sock_init_data_uid(struct socket *sock, struct sock *sk, kuid_t uid)
3650 {
3651 	sk_init_common(sk);
3652 	sk->sk_send_head	=	NULL;
3653 
3654 	timer_setup(&sk->sk_timer, NULL, 0);
3655 
3656 	sk->sk_allocation	=	GFP_KERNEL;
3657 	sk->sk_rcvbuf		=	READ_ONCE(sysctl_rmem_default);
3658 	sk->sk_sndbuf		=	READ_ONCE(sysctl_wmem_default);
3659 	sk->sk_state		=	TCP_CLOSE;
3660 	sk->sk_use_task_frag	=	true;
3661 	sk_set_socket(sk, sock);
3662 
3663 	sock_set_flag(sk, SOCK_ZAPPED);
3664 
3665 	if (sock) {
3666 		sk->sk_type	=	sock->type;
3667 		RCU_INIT_POINTER(sk->sk_wq, &sock->wq);
3668 		sock->sk	=	sk;
3669 	} else {
3670 		RCU_INIT_POINTER(sk->sk_wq, NULL);
3671 	}
3672 	sk->sk_uid	=	uid;
3673 
3674 	sk->sk_state_change	=	sock_def_wakeup;
3675 	sk->sk_data_ready	=	sock_def_readable;
3676 	sk->sk_write_space	=	sock_def_write_space;
3677 	sk->sk_error_report	=	sock_def_error_report;
3678 	sk->sk_destruct		=	sock_def_destruct;
3679 
3680 	sk->sk_frag.page	=	NULL;
3681 	sk->sk_frag.offset	=	0;
3682 	sk->sk_peek_off		=	-1;
3683 
3684 	sk->sk_peer_pid 	=	NULL;
3685 	sk->sk_peer_cred	=	NULL;
3686 	spin_lock_init(&sk->sk_peer_lock);
3687 
3688 	sk->sk_write_pending	=	0;
3689 	sk->sk_rcvlowat		=	1;
3690 	sk->sk_rcvtimeo		=	MAX_SCHEDULE_TIMEOUT;
3691 	sk->sk_sndtimeo		=	MAX_SCHEDULE_TIMEOUT;
3692 
3693 	sk->sk_stamp = SK_DEFAULT_STAMP;
3694 #if BITS_PER_LONG==32
3695 	seqlock_init(&sk->sk_stamp_seq);
3696 #endif
3697 	atomic_set(&sk->sk_zckey, 0);
3698 
3699 #ifdef CONFIG_NET_RX_BUSY_POLL
3700 	sk->sk_napi_id		=	0;
3701 	sk->sk_ll_usec		=	READ_ONCE(sysctl_net_busy_read);
3702 #endif
3703 
3704 	sk->sk_max_pacing_rate = ~0UL;
3705 	sk->sk_pacing_rate = ~0UL;
3706 	WRITE_ONCE(sk->sk_pacing_shift, 10);
3707 	sk->sk_incoming_cpu = -1;
3708 
3709 	sk_rx_queue_clear(sk);
3710 	/*
3711 	 * Before updating sk_refcnt, we must commit prior changes to memory
3712 	 * (Documentation/RCU/rculist_nulls.rst for details)
3713 	 */
3714 	smp_wmb();
3715 	refcount_set(&sk->sk_refcnt, 1);
3716 	atomic_set(&sk->sk_drops, 0);
3717 }
3718 EXPORT_SYMBOL(sock_init_data_uid);
3719 
sock_init_data(struct socket * sock,struct sock * sk)3720 void sock_init_data(struct socket *sock, struct sock *sk)
3721 {
3722 	kuid_t uid = sock ?
3723 		SOCK_INODE(sock)->i_uid :
3724 		make_kuid(sock_net(sk)->user_ns, 0);
3725 
3726 	sock_init_data_uid(sock, sk, uid);
3727 }
3728 EXPORT_SYMBOL(sock_init_data);
3729 
lock_sock_nested(struct sock * sk,int subclass)3730 void lock_sock_nested(struct sock *sk, int subclass)
3731 {
3732 	/* The sk_lock has mutex_lock() semantics here. */
3733 	mutex_acquire(&sk->sk_lock.dep_map, subclass, 0, _RET_IP_);
3734 
3735 	might_sleep();
3736 	spin_lock_bh(&sk->sk_lock.slock);
3737 	if (sock_owned_by_user_nocheck(sk))
3738 		__lock_sock(sk);
3739 	sk->sk_lock.owned = 1;
3740 	spin_unlock_bh(&sk->sk_lock.slock);
3741 }
3742 EXPORT_SYMBOL(lock_sock_nested);
3743 
release_sock(struct sock * sk)3744 void release_sock(struct sock *sk)
3745 {
3746 	spin_lock_bh(&sk->sk_lock.slock);
3747 	if (sk->sk_backlog.tail)
3748 		__release_sock(sk);
3749 
3750 	if (sk->sk_prot->release_cb)
3751 		INDIRECT_CALL_INET_1(sk->sk_prot->release_cb,
3752 				     tcp_release_cb, sk);
3753 
3754 	sock_release_ownership(sk);
3755 	if (waitqueue_active(&sk->sk_lock.wq))
3756 		wake_up(&sk->sk_lock.wq);
3757 	spin_unlock_bh(&sk->sk_lock.slock);
3758 }
3759 EXPORT_SYMBOL(release_sock);
3760 
__lock_sock_fast(struct sock * sk)3761 bool __lock_sock_fast(struct sock *sk) __acquires(&sk->sk_lock.slock)
3762 {
3763 	might_sleep();
3764 	spin_lock_bh(&sk->sk_lock.slock);
3765 
3766 	if (!sock_owned_by_user_nocheck(sk)) {
3767 		/*
3768 		 * Fast path return with bottom halves disabled and
3769 		 * sock::sk_lock.slock held.
3770 		 *
3771 		 * The 'mutex' is not contended and holding
3772 		 * sock::sk_lock.slock prevents all other lockers to
3773 		 * proceed so the corresponding unlock_sock_fast() can
3774 		 * avoid the slow path of release_sock() completely and
3775 		 * just release slock.
3776 		 *
3777 		 * From a semantical POV this is equivalent to 'acquiring'
3778 		 * the 'mutex', hence the corresponding lockdep
3779 		 * mutex_release() has to happen in the fast path of
3780 		 * unlock_sock_fast().
3781 		 */
3782 		return false;
3783 	}
3784 
3785 	__lock_sock(sk);
3786 	sk->sk_lock.owned = 1;
3787 	__acquire(&sk->sk_lock.slock);
3788 	spin_unlock_bh(&sk->sk_lock.slock);
3789 	return true;
3790 }
3791 EXPORT_SYMBOL(__lock_sock_fast);
3792 
sock_gettstamp(struct socket * sock,void __user * userstamp,bool timeval,bool time32)3793 int sock_gettstamp(struct socket *sock, void __user *userstamp,
3794 		   bool timeval, bool time32)
3795 {
3796 	struct sock *sk = sock->sk;
3797 	struct timespec64 ts;
3798 
3799 	sock_enable_timestamp(sk, SOCK_TIMESTAMP);
3800 	ts = ktime_to_timespec64(sock_read_timestamp(sk));
3801 	if (ts.tv_sec == -1)
3802 		return -ENOENT;
3803 	if (ts.tv_sec == 0) {
3804 		ktime_t kt = ktime_get_real();
3805 		sock_write_timestamp(sk, kt);
3806 		ts = ktime_to_timespec64(kt);
3807 	}
3808 
3809 	if (timeval)
3810 		ts.tv_nsec /= 1000;
3811 
3812 #ifdef CONFIG_COMPAT_32BIT_TIME
3813 	if (time32)
3814 		return put_old_timespec32(&ts, userstamp);
3815 #endif
3816 #ifdef CONFIG_SPARC64
3817 	/* beware of padding in sparc64 timeval */
3818 	if (timeval && !in_compat_syscall()) {
3819 		struct __kernel_old_timeval __user tv = {
3820 			.tv_sec = ts.tv_sec,
3821 			.tv_usec = ts.tv_nsec,
3822 		};
3823 		if (copy_to_user(userstamp, &tv, sizeof(tv)))
3824 			return -EFAULT;
3825 		return 0;
3826 	}
3827 #endif
3828 	return put_timespec64(&ts, userstamp);
3829 }
3830 EXPORT_SYMBOL(sock_gettstamp);
3831 
sock_enable_timestamp(struct sock * sk,enum sock_flags flag)3832 void sock_enable_timestamp(struct sock *sk, enum sock_flags flag)
3833 {
3834 	if (!sock_flag(sk, flag)) {
3835 		unsigned long previous_flags = sk->sk_flags;
3836 
3837 		sock_set_flag(sk, flag);
3838 		/*
3839 		 * we just set one of the two flags which require net
3840 		 * time stamping, but time stamping might have been on
3841 		 * already because of the other one
3842 		 */
3843 		if (sock_needs_netstamp(sk) &&
3844 		    !(previous_flags & SK_FLAGS_TIMESTAMP))
3845 			net_enable_timestamp();
3846 	}
3847 }
3848 
sock_recv_errqueue(struct sock * sk,struct msghdr * msg,int len,int level,int type)3849 int sock_recv_errqueue(struct sock *sk, struct msghdr *msg, int len,
3850 		       int level, int type)
3851 {
3852 	struct sock_exterr_skb *serr;
3853 	struct sk_buff *skb;
3854 	int copied, err;
3855 
3856 	err = -EAGAIN;
3857 	skb = sock_dequeue_err_skb(sk);
3858 	if (skb == NULL)
3859 		goto out;
3860 
3861 	copied = skb->len;
3862 	if (copied > len) {
3863 		msg->msg_flags |= MSG_TRUNC;
3864 		copied = len;
3865 	}
3866 	err = skb_copy_datagram_msg(skb, 0, msg, copied);
3867 	if (err)
3868 		goto out_free_skb;
3869 
3870 	sock_recv_timestamp(msg, sk, skb);
3871 
3872 	serr = SKB_EXT_ERR(skb);
3873 	put_cmsg(msg, level, type, sizeof(serr->ee), &serr->ee);
3874 
3875 	msg->msg_flags |= MSG_ERRQUEUE;
3876 	err = copied;
3877 
3878 out_free_skb:
3879 	kfree_skb(skb);
3880 out:
3881 	return err;
3882 }
3883 EXPORT_SYMBOL(sock_recv_errqueue);
3884 
3885 /*
3886  *	Get a socket option on an socket.
3887  *
3888  *	FIX: POSIX 1003.1g is very ambiguous here. It states that
3889  *	asynchronous errors should be reported by getsockopt. We assume
3890  *	this means if you specify SO_ERROR (otherwise what is the point of it).
3891  */
sock_common_getsockopt(struct socket * sock,int level,int optname,char __user * optval,int __user * optlen)3892 int sock_common_getsockopt(struct socket *sock, int level, int optname,
3893 			   char __user *optval, int __user *optlen)
3894 {
3895 	struct sock *sk = sock->sk;
3896 
3897 	/* IPV6_ADDRFORM can change sk->sk_prot under us. */
3898 	return READ_ONCE(sk->sk_prot)->getsockopt(sk, level, optname, optval, optlen);
3899 }
3900 EXPORT_SYMBOL(sock_common_getsockopt);
3901 
sock_common_recvmsg(struct socket * sock,struct msghdr * msg,size_t size,int flags)3902 int sock_common_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
3903 			int flags)
3904 {
3905 	struct sock *sk = sock->sk;
3906 	int addr_len = 0;
3907 	int err;
3908 
3909 	err = sk->sk_prot->recvmsg(sk, msg, size, flags, &addr_len);
3910 	if (err >= 0)
3911 		msg->msg_namelen = addr_len;
3912 	return err;
3913 }
3914 EXPORT_SYMBOL(sock_common_recvmsg);
3915 
3916 /*
3917  *	Set socket options on an inet socket.
3918  */
sock_common_setsockopt(struct socket * sock,int level,int optname,sockptr_t optval,unsigned int optlen)3919 int sock_common_setsockopt(struct socket *sock, int level, int optname,
3920 			   sockptr_t optval, unsigned int optlen)
3921 {
3922 	struct sock *sk = sock->sk;
3923 
3924 	/* IPV6_ADDRFORM can change sk->sk_prot under us. */
3925 	return READ_ONCE(sk->sk_prot)->setsockopt(sk, level, optname, optval, optlen);
3926 }
3927 EXPORT_SYMBOL(sock_common_setsockopt);
3928 
sk_common_release(struct sock * sk)3929 void sk_common_release(struct sock *sk)
3930 {
3931 	if (sk->sk_prot->destroy)
3932 		sk->sk_prot->destroy(sk);
3933 
3934 	/*
3935 	 * Observation: when sk_common_release is called, processes have
3936 	 * no access to socket. But net still has.
3937 	 * Step one, detach it from networking:
3938 	 *
3939 	 * A. Remove from hash tables.
3940 	 */
3941 
3942 	sk->sk_prot->unhash(sk);
3943 
3944 	/*
3945 	 * In this point socket cannot receive new packets, but it is possible
3946 	 * that some packets are in flight because some CPU runs receiver and
3947 	 * did hash table lookup before we unhashed socket. They will achieve
3948 	 * receive queue and will be purged by socket destructor.
3949 	 *
3950 	 * Also we still have packets pending on receive queue and probably,
3951 	 * our own packets waiting in device queues. sock_destroy will drain
3952 	 * receive queue, but transmitted packets will delay socket destruction
3953 	 * until the last reference will be released.
3954 	 */
3955 
3956 	sock_orphan(sk);
3957 
3958 	xfrm_sk_free_policy(sk);
3959 
3960 	sock_put(sk);
3961 }
3962 EXPORT_SYMBOL(sk_common_release);
3963 
sk_get_meminfo(const struct sock * sk,u32 * mem)3964 void sk_get_meminfo(const struct sock *sk, u32 *mem)
3965 {
3966 	memset(mem, 0, sizeof(*mem) * SK_MEMINFO_VARS);
3967 
3968 	mem[SK_MEMINFO_RMEM_ALLOC] = sk_rmem_alloc_get(sk);
3969 	mem[SK_MEMINFO_RCVBUF] = READ_ONCE(sk->sk_rcvbuf);
3970 	mem[SK_MEMINFO_WMEM_ALLOC] = sk_wmem_alloc_get(sk);
3971 	mem[SK_MEMINFO_SNDBUF] = READ_ONCE(sk->sk_sndbuf);
3972 	mem[SK_MEMINFO_FWD_ALLOC] = READ_ONCE(sk->sk_forward_alloc);
3973 	mem[SK_MEMINFO_WMEM_QUEUED] = READ_ONCE(sk->sk_wmem_queued);
3974 	mem[SK_MEMINFO_OPTMEM] = atomic_read(&sk->sk_omem_alloc);
3975 	mem[SK_MEMINFO_BACKLOG] = READ_ONCE(sk->sk_backlog.len);
3976 	mem[SK_MEMINFO_DROPS] = atomic_read(&sk->sk_drops);
3977 }
3978 
3979 #ifdef CONFIG_PROC_FS
3980 static DECLARE_BITMAP(proto_inuse_idx, PROTO_INUSE_NR);
3981 
sock_prot_inuse_get(struct net * net,struct proto * prot)3982 int sock_prot_inuse_get(struct net *net, struct proto *prot)
3983 {
3984 	int cpu, idx = prot->inuse_idx;
3985 	int res = 0;
3986 
3987 	for_each_possible_cpu(cpu)
3988 		res += per_cpu_ptr(net->core.prot_inuse, cpu)->val[idx];
3989 
3990 	return res >= 0 ? res : 0;
3991 }
3992 EXPORT_SYMBOL_GPL(sock_prot_inuse_get);
3993 
sock_inuse_get(struct net * net)3994 int sock_inuse_get(struct net *net)
3995 {
3996 	int cpu, res = 0;
3997 
3998 	for_each_possible_cpu(cpu)
3999 		res += per_cpu_ptr(net->core.prot_inuse, cpu)->all;
4000 
4001 	return res;
4002 }
4003 
4004 EXPORT_SYMBOL_GPL(sock_inuse_get);
4005 
sock_inuse_init_net(struct net * net)4006 static int __net_init sock_inuse_init_net(struct net *net)
4007 {
4008 	net->core.prot_inuse = alloc_percpu(struct prot_inuse);
4009 	if (net->core.prot_inuse == NULL)
4010 		return -ENOMEM;
4011 	return 0;
4012 }
4013 
sock_inuse_exit_net(struct net * net)4014 static void __net_exit sock_inuse_exit_net(struct net *net)
4015 {
4016 	free_percpu(net->core.prot_inuse);
4017 }
4018 
4019 static struct pernet_operations net_inuse_ops = {
4020 	.init = sock_inuse_init_net,
4021 	.exit = sock_inuse_exit_net,
4022 };
4023 
net_inuse_init(void)4024 static __init int net_inuse_init(void)
4025 {
4026 	if (register_pernet_subsys(&net_inuse_ops))
4027 		panic("Cannot initialize net inuse counters");
4028 
4029 	return 0;
4030 }
4031 
4032 core_initcall(net_inuse_init);
4033 
assign_proto_idx(struct proto * prot)4034 static int assign_proto_idx(struct proto *prot)
4035 {
4036 	prot->inuse_idx = find_first_zero_bit(proto_inuse_idx, PROTO_INUSE_NR);
4037 
4038 	if (unlikely(prot->inuse_idx == PROTO_INUSE_NR)) {
4039 		pr_err("PROTO_INUSE_NR exhausted\n");
4040 		return -ENOSPC;
4041 	}
4042 
4043 	set_bit(prot->inuse_idx, proto_inuse_idx);
4044 	return 0;
4045 }
4046 
release_proto_idx(struct proto * prot)4047 static void release_proto_idx(struct proto *prot)
4048 {
4049 	if (prot->inuse_idx != PROTO_INUSE_NR)
4050 		clear_bit(prot->inuse_idx, proto_inuse_idx);
4051 }
4052 #else
assign_proto_idx(struct proto * prot)4053 static inline int assign_proto_idx(struct proto *prot)
4054 {
4055 	return 0;
4056 }
4057 
release_proto_idx(struct proto * prot)4058 static inline void release_proto_idx(struct proto *prot)
4059 {
4060 }
4061 
4062 #endif
4063 
tw_prot_cleanup(struct timewait_sock_ops * twsk_prot)4064 static void tw_prot_cleanup(struct timewait_sock_ops *twsk_prot)
4065 {
4066 	if (!twsk_prot)
4067 		return;
4068 	kfree(twsk_prot->twsk_slab_name);
4069 	twsk_prot->twsk_slab_name = NULL;
4070 	kmem_cache_destroy(twsk_prot->twsk_slab);
4071 	twsk_prot->twsk_slab = NULL;
4072 }
4073 
tw_prot_init(const struct proto * prot)4074 static int tw_prot_init(const struct proto *prot)
4075 {
4076 	struct timewait_sock_ops *twsk_prot = prot->twsk_prot;
4077 
4078 	if (!twsk_prot)
4079 		return 0;
4080 
4081 	twsk_prot->twsk_slab_name = kasprintf(GFP_KERNEL, "tw_sock_%s",
4082 					      prot->name);
4083 	if (!twsk_prot->twsk_slab_name)
4084 		return -ENOMEM;
4085 
4086 	twsk_prot->twsk_slab =
4087 		kmem_cache_create(twsk_prot->twsk_slab_name,
4088 				  twsk_prot->twsk_obj_size, 0,
4089 				  SLAB_ACCOUNT | prot->slab_flags,
4090 				  NULL);
4091 	if (!twsk_prot->twsk_slab) {
4092 		pr_crit("%s: Can't create timewait sock SLAB cache!\n",
4093 			prot->name);
4094 		return -ENOMEM;
4095 	}
4096 
4097 	return 0;
4098 }
4099 
req_prot_cleanup(struct request_sock_ops * rsk_prot)4100 static void req_prot_cleanup(struct request_sock_ops *rsk_prot)
4101 {
4102 	if (!rsk_prot)
4103 		return;
4104 	kfree(rsk_prot->slab_name);
4105 	rsk_prot->slab_name = NULL;
4106 	kmem_cache_destroy(rsk_prot->slab);
4107 	rsk_prot->slab = NULL;
4108 }
4109 
req_prot_init(const struct proto * prot)4110 static int req_prot_init(const struct proto *prot)
4111 {
4112 	struct request_sock_ops *rsk_prot = prot->rsk_prot;
4113 
4114 	if (!rsk_prot)
4115 		return 0;
4116 
4117 	rsk_prot->slab_name = kasprintf(GFP_KERNEL, "request_sock_%s",
4118 					prot->name);
4119 	if (!rsk_prot->slab_name)
4120 		return -ENOMEM;
4121 
4122 	rsk_prot->slab = kmem_cache_create(rsk_prot->slab_name,
4123 					   rsk_prot->obj_size, 0,
4124 					   SLAB_ACCOUNT | prot->slab_flags,
4125 					   NULL);
4126 
4127 	if (!rsk_prot->slab) {
4128 		pr_crit("%s: Can't create request sock SLAB cache!\n",
4129 			prot->name);
4130 		return -ENOMEM;
4131 	}
4132 	return 0;
4133 }
4134 
proto_register(struct proto * prot,int alloc_slab)4135 int proto_register(struct proto *prot, int alloc_slab)
4136 {
4137 	int ret = -ENOBUFS;
4138 
4139 	if (prot->memory_allocated && !prot->sysctl_mem) {
4140 		pr_err("%s: missing sysctl_mem\n", prot->name);
4141 		return -EINVAL;
4142 	}
4143 	if (prot->memory_allocated && !prot->per_cpu_fw_alloc) {
4144 		pr_err("%s: missing per_cpu_fw_alloc\n", prot->name);
4145 		return -EINVAL;
4146 	}
4147 	if (alloc_slab) {
4148 		prot->slab = kmem_cache_create_usercopy(prot->name,
4149 					prot->obj_size, 0,
4150 					SLAB_HWCACHE_ALIGN | SLAB_ACCOUNT |
4151 					prot->slab_flags,
4152 					prot->useroffset, prot->usersize,
4153 					NULL);
4154 
4155 		if (prot->slab == NULL) {
4156 			pr_crit("%s: Can't create sock SLAB cache!\n",
4157 				prot->name);
4158 			goto out;
4159 		}
4160 
4161 		if (req_prot_init(prot))
4162 			goto out_free_request_sock_slab;
4163 
4164 		if (tw_prot_init(prot))
4165 			goto out_free_timewait_sock_slab;
4166 	}
4167 
4168 	mutex_lock(&proto_list_mutex);
4169 	ret = assign_proto_idx(prot);
4170 	if (ret) {
4171 		mutex_unlock(&proto_list_mutex);
4172 		goto out_free_timewait_sock_slab;
4173 	}
4174 	list_add(&prot->node, &proto_list);
4175 	mutex_unlock(&proto_list_mutex);
4176 	return ret;
4177 
4178 out_free_timewait_sock_slab:
4179 	if (alloc_slab)
4180 		tw_prot_cleanup(prot->twsk_prot);
4181 out_free_request_sock_slab:
4182 	if (alloc_slab) {
4183 		req_prot_cleanup(prot->rsk_prot);
4184 
4185 		kmem_cache_destroy(prot->slab);
4186 		prot->slab = NULL;
4187 	}
4188 out:
4189 	return ret;
4190 }
4191 EXPORT_SYMBOL(proto_register);
4192 
proto_unregister(struct proto * prot)4193 void proto_unregister(struct proto *prot)
4194 {
4195 	mutex_lock(&proto_list_mutex);
4196 	release_proto_idx(prot);
4197 	list_del(&prot->node);
4198 	mutex_unlock(&proto_list_mutex);
4199 
4200 	kmem_cache_destroy(prot->slab);
4201 	prot->slab = NULL;
4202 
4203 	req_prot_cleanup(prot->rsk_prot);
4204 	tw_prot_cleanup(prot->twsk_prot);
4205 }
4206 EXPORT_SYMBOL(proto_unregister);
4207 
sock_load_diag_module(int family,int protocol)4208 int sock_load_diag_module(int family, int protocol)
4209 {
4210 	if (!protocol) {
4211 		if (!sock_is_registered(family))
4212 			return -ENOENT;
4213 
4214 		return request_module("net-pf-%d-proto-%d-type-%d", PF_NETLINK,
4215 				      NETLINK_SOCK_DIAG, family);
4216 	}
4217 
4218 #ifdef CONFIG_INET
4219 	if (family == AF_INET &&
4220 	    protocol != IPPROTO_RAW &&
4221 	    protocol < MAX_INET_PROTOS &&
4222 	    !rcu_access_pointer(inet_protos[protocol]))
4223 		return -ENOENT;
4224 #endif
4225 
4226 	return request_module("net-pf-%d-proto-%d-type-%d-%d", PF_NETLINK,
4227 			      NETLINK_SOCK_DIAG, family, protocol);
4228 }
4229 EXPORT_SYMBOL(sock_load_diag_module);
4230 
4231 #ifdef CONFIG_PROC_FS
proto_seq_start(struct seq_file * seq,loff_t * pos)4232 static void *proto_seq_start(struct seq_file *seq, loff_t *pos)
4233 	__acquires(proto_list_mutex)
4234 {
4235 	mutex_lock(&proto_list_mutex);
4236 	return seq_list_start_head(&proto_list, *pos);
4237 }
4238 
proto_seq_next(struct seq_file * seq,void * v,loff_t * pos)4239 static void *proto_seq_next(struct seq_file *seq, void *v, loff_t *pos)
4240 {
4241 	return seq_list_next(v, &proto_list, pos);
4242 }
4243 
proto_seq_stop(struct seq_file * seq,void * v)4244 static void proto_seq_stop(struct seq_file *seq, void *v)
4245 	__releases(proto_list_mutex)
4246 {
4247 	mutex_unlock(&proto_list_mutex);
4248 }
4249 
proto_method_implemented(const void * method)4250 static char proto_method_implemented(const void *method)
4251 {
4252 	return method == NULL ? 'n' : 'y';
4253 }
sock_prot_memory_allocated(struct proto * proto)4254 static long sock_prot_memory_allocated(struct proto *proto)
4255 {
4256 	return proto->memory_allocated != NULL ? proto_memory_allocated(proto) : -1L;
4257 }
4258 
sock_prot_memory_pressure(struct proto * proto)4259 static const char *sock_prot_memory_pressure(struct proto *proto)
4260 {
4261 	return proto->memory_pressure != NULL ?
4262 	proto_memory_pressure(proto) ? "yes" : "no" : "NI";
4263 }
4264 
proto_seq_printf(struct seq_file * seq,struct proto * proto)4265 static void proto_seq_printf(struct seq_file *seq, struct proto *proto)
4266 {
4267 
4268 	seq_printf(seq, "%-9s %4u %6d  %6ld   %-3s %6u   %-3s  %-10s "
4269 			"%2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c\n",
4270 		   proto->name,
4271 		   proto->obj_size,
4272 		   sock_prot_inuse_get(seq_file_net(seq), proto),
4273 		   sock_prot_memory_allocated(proto),
4274 		   sock_prot_memory_pressure(proto),
4275 		   proto->max_header,
4276 		   proto->slab == NULL ? "no" : "yes",
4277 		   module_name(proto->owner),
4278 		   proto_method_implemented(proto->close),
4279 		   proto_method_implemented(proto->connect),
4280 		   proto_method_implemented(proto->disconnect),
4281 		   proto_method_implemented(proto->accept),
4282 		   proto_method_implemented(proto->ioctl),
4283 		   proto_method_implemented(proto->init),
4284 		   proto_method_implemented(proto->destroy),
4285 		   proto_method_implemented(proto->shutdown),
4286 		   proto_method_implemented(proto->setsockopt),
4287 		   proto_method_implemented(proto->getsockopt),
4288 		   proto_method_implemented(proto->sendmsg),
4289 		   proto_method_implemented(proto->recvmsg),
4290 		   proto_method_implemented(proto->bind),
4291 		   proto_method_implemented(proto->backlog_rcv),
4292 		   proto_method_implemented(proto->hash),
4293 		   proto_method_implemented(proto->unhash),
4294 		   proto_method_implemented(proto->get_port),
4295 		   proto_method_implemented(proto->enter_memory_pressure));
4296 }
4297 
proto_seq_show(struct seq_file * seq,void * v)4298 static int proto_seq_show(struct seq_file *seq, void *v)
4299 {
4300 	if (v == &proto_list)
4301 		seq_printf(seq, "%-9s %-4s %-8s %-6s %-5s %-7s %-4s %-10s %s",
4302 			   "protocol",
4303 			   "size",
4304 			   "sockets",
4305 			   "memory",
4306 			   "press",
4307 			   "maxhdr",
4308 			   "slab",
4309 			   "module",
4310 			   "cl co di ac io in de sh ss gs se re bi br ha uh gp em\n");
4311 	else
4312 		proto_seq_printf(seq, list_entry(v, struct proto, node));
4313 	return 0;
4314 }
4315 
4316 static const struct seq_operations proto_seq_ops = {
4317 	.start  = proto_seq_start,
4318 	.next   = proto_seq_next,
4319 	.stop   = proto_seq_stop,
4320 	.show   = proto_seq_show,
4321 };
4322 
proto_init_net(struct net * net)4323 static __net_init int proto_init_net(struct net *net)
4324 {
4325 	if (!proc_create_net("protocols", 0444, net->proc_net, &proto_seq_ops,
4326 			sizeof(struct seq_net_private)))
4327 		return -ENOMEM;
4328 
4329 	return 0;
4330 }
4331 
proto_exit_net(struct net * net)4332 static __net_exit void proto_exit_net(struct net *net)
4333 {
4334 	remove_proc_entry("protocols", net->proc_net);
4335 }
4336 
4337 
4338 static __net_initdata struct pernet_operations proto_net_ops = {
4339 	.init = proto_init_net,
4340 	.exit = proto_exit_net,
4341 };
4342 
proto_init(void)4343 static int __init proto_init(void)
4344 {
4345 	return register_pernet_subsys(&proto_net_ops);
4346 }
4347 
4348 subsys_initcall(proto_init);
4349 
4350 #endif /* PROC_FS */
4351 
4352 #ifdef CONFIG_NET_RX_BUSY_POLL
sk_busy_loop_end(void * p,unsigned long start_time)4353 bool sk_busy_loop_end(void *p, unsigned long start_time)
4354 {
4355 	struct sock *sk = p;
4356 
4357 	if (!skb_queue_empty_lockless(&sk->sk_receive_queue))
4358 		return true;
4359 
4360 	if (sk_is_udp(sk) &&
4361 	    !skb_queue_empty_lockless(&udp_sk(sk)->reader_queue))
4362 		return true;
4363 
4364 	return sk_busy_loop_timeout(sk, start_time);
4365 }
4366 EXPORT_SYMBOL(sk_busy_loop_end);
4367 #endif /* CONFIG_NET_RX_BUSY_POLL */
4368 
sock_bind_add(struct sock * sk,struct sockaddr * addr,int addr_len)4369 int sock_bind_add(struct sock *sk, struct sockaddr *addr, int addr_len)
4370 {
4371 	if (!sk->sk_prot->bind_add)
4372 		return -EOPNOTSUPP;
4373 	return sk->sk_prot->bind_add(sk, addr, addr_len);
4374 }
4375 EXPORT_SYMBOL(sock_bind_add);
4376 
4377 /* 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)4378 int sock_ioctl_inout(struct sock *sk, unsigned int cmd,
4379 		     void __user *arg, void *karg, size_t size)
4380 {
4381 	int ret;
4382 
4383 	if (copy_from_user(karg, arg, size))
4384 		return -EFAULT;
4385 
4386 	ret = READ_ONCE(sk->sk_prot)->ioctl(sk, cmd, karg);
4387 	if (ret)
4388 		return ret;
4389 
4390 	if (copy_to_user(arg, karg, size))
4391 		return -EFAULT;
4392 
4393 	return 0;
4394 }
4395 EXPORT_SYMBOL(sock_ioctl_inout);
4396 
4397 /* This is the most common ioctl prep function, where the result (4 bytes) is
4398  * copied back to userspace if the ioctl() returns successfully. No input is
4399  * copied from userspace as input argument.
4400  */
sock_ioctl_out(struct sock * sk,unsigned int cmd,void __user * arg)4401 static int sock_ioctl_out(struct sock *sk, unsigned int cmd, void __user *arg)
4402 {
4403 	int ret, karg = 0;
4404 
4405 	ret = READ_ONCE(sk->sk_prot)->ioctl(sk, cmd, &karg);
4406 	if (ret)
4407 		return ret;
4408 
4409 	return put_user(karg, (int __user *)arg);
4410 }
4411 
4412 /* A wrapper around sock ioctls, which copies the data from userspace
4413  * (depending on the protocol/ioctl), and copies back the result to userspace.
4414  * The main motivation for this function is to pass kernel memory to the
4415  * protocol ioctl callbacks, instead of userspace memory.
4416  */
sk_ioctl(struct sock * sk,unsigned int cmd,void __user * arg)4417 int sk_ioctl(struct sock *sk, unsigned int cmd, void __user *arg)
4418 {
4419 	int rc = 1;
4420 
4421 	if (sk->sk_type == SOCK_RAW && sk->sk_family == AF_INET)
4422 		rc = ipmr_sk_ioctl(sk, cmd, arg);
4423 	else if (sk->sk_type == SOCK_RAW && sk->sk_family == AF_INET6)
4424 		rc = ip6mr_sk_ioctl(sk, cmd, arg);
4425 	else if (sk_is_phonet(sk))
4426 		rc = phonet_sk_ioctl(sk, cmd, arg);
4427 
4428 	/* If ioctl was processed, returns its value */
4429 	if (rc <= 0)
4430 		return rc;
4431 
4432 	/* Otherwise call the default handler */
4433 	return sock_ioctl_out(sk, cmd, arg);
4434 }
4435 EXPORT_SYMBOL(sk_ioctl);
4436 
sock_struct_check(void)4437 static int __init sock_struct_check(void)
4438 {
4439 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_rx, sk_drops);
4440 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_rx, sk_peek_off);
4441 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_rx, sk_error_queue);
4442 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_rx, sk_receive_queue);
4443 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_rx, sk_backlog);
4444 
4445 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_rx, sk_rx_dst);
4446 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_rx, sk_rx_dst_ifindex);
4447 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_rx, sk_rx_dst_cookie);
4448 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_rx, sk_rcvbuf);
4449 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_rx, sk_filter);
4450 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_rx, sk_wq);
4451 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_rx, sk_data_ready);
4452 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_rx, sk_rcvtimeo);
4453 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_rx, sk_rcvlowat);
4454 
4455 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_rxtx, sk_err);
4456 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_rxtx, sk_socket);
4457 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_rxtx, sk_memcg);
4458 
4459 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_rxtx, sk_lock);
4460 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_rxtx, sk_reserved_mem);
4461 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_rxtx, sk_forward_alloc);
4462 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_rxtx, sk_tsflags);
4463 
4464 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_omem_alloc);
4465 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_omem_alloc);
4466 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_sndbuf);
4467 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_wmem_queued);
4468 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_wmem_alloc);
4469 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_tsq_flags);
4470 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_send_head);
4471 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_write_queue);
4472 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_write_pending);
4473 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_dst_pending_confirm);
4474 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_pacing_status);
4475 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_frag);
4476 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_timer);
4477 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_pacing_rate);
4478 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_zckey);
4479 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_tskey);
4480 
4481 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_max_pacing_rate);
4482 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_sndtimeo);
4483 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_priority);
4484 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_mark);
4485 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_dst_cache);
4486 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_route_caps);
4487 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_gso_type);
4488 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_gso_max_size);
4489 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_allocation);
4490 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_txhash);
4491 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_gso_max_segs);
4492 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_pacing_shift);
4493 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_use_task_frag);
4494 	return 0;
4495 }
4496 
4497 core_initcall(sock_struct_check);
4498