xref: /linux/net/core/sock.c (revision ddd664bbff63e09e7a7f9acae9c43605d4cf185f)
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, int wmem_alloc);
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 = 4 << 20;
285 EXPORT_SYMBOL(sysctl_wmem_max);
286 __u32 sysctl_rmem_max __read_mostly = 4 << 20;
287 EXPORT_SYMBOL(sysctl_rmem_max);
288 __u32 sysctl_wmem_default __read_mostly = SK_WMEM_DEFAULT;
289 __u32 sysctl_rmem_default __read_mostly = SK_RMEM_DEFAULT;
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 		sk_drops_inc(sk);
495 		trace_sock_rcvqueue_full(sk, skb);
496 		return -ENOMEM;
497 	}
498 
499 	if (!sk_rmem_schedule(sk, skb, skb->truesize)) {
500 		sk_drops_inc(sk);
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 
523 enum skb_drop_reason
sock_queue_rcv_skb_reason(struct sock * sk,struct sk_buff * skb)524 sock_queue_rcv_skb_reason(struct sock *sk, struct sk_buff *skb)
525 {
526 	enum skb_drop_reason drop_reason;
527 	int err;
528 
529 	drop_reason = sk_filter_reason(sk, skb);
530 	if (drop_reason)
531 		return drop_reason;
532 
533 	err = __sock_queue_rcv_skb(sk, skb);
534 	switch (err) {
535 	case -ENOMEM:
536 		return SKB_DROP_REASON_SOCKET_RCVBUFF;
537 	case -ENOBUFS:
538 		return SKB_DROP_REASON_PROTO_MEM;
539 	}
540 	return SKB_NOT_DROPPED_YET;
541 }
542 EXPORT_SYMBOL(sock_queue_rcv_skb_reason);
543 
__sk_receive_skb(struct sock * sk,struct sk_buff * skb,const int nested,unsigned int trim_cap,bool refcounted)544 int __sk_receive_skb(struct sock *sk, struct sk_buff *skb,
545 		     const int nested, unsigned int trim_cap, bool refcounted)
546 {
547 	enum skb_drop_reason reason;
548 	int rc = NET_RX_SUCCESS;
549 	int err;
550 
551 	reason = sk_filter_trim_cap(sk, skb, trim_cap);
552 	if (reason)
553 		goto discard_and_relse;
554 
555 	skb->dev = NULL;
556 
557 	if (sk_rcvqueues_full(sk, READ_ONCE(sk->sk_rcvbuf))) {
558 		sk_drops_inc(sk);
559 		reason = SKB_DROP_REASON_SOCKET_RCVBUFF;
560 		goto discard_and_relse;
561 	}
562 	if (nested)
563 		bh_lock_sock_nested(sk);
564 	else
565 		bh_lock_sock(sk);
566 	if (!sock_owned_by_user(sk)) {
567 		/*
568 		 * trylock + unlock semantics:
569 		 */
570 		mutex_acquire(&sk->sk_lock.dep_map, 0, 1, _RET_IP_);
571 
572 		rc = sk_backlog_rcv(sk, skb);
573 
574 		mutex_release(&sk->sk_lock.dep_map, _RET_IP_);
575 	} else if ((err = sk_add_backlog(sk, skb, READ_ONCE(sk->sk_rcvbuf)))) {
576 		bh_unlock_sock(sk);
577 		if (err == -ENOMEM)
578 			reason = SKB_DROP_REASON_PFMEMALLOC;
579 		if (err == -ENOBUFS)
580 			reason = SKB_DROP_REASON_SOCKET_BACKLOG;
581 		sk_drops_inc(sk);
582 		goto discard_and_relse;
583 	}
584 
585 	bh_unlock_sock(sk);
586 out:
587 	if (refcounted)
588 		sock_put(sk);
589 	return rc;
590 discard_and_relse:
591 	sk_skb_reason_drop(sk, skb, reason);
592 	goto out;
593 }
594 EXPORT_SYMBOL(__sk_receive_skb);
595 
596 INDIRECT_CALLABLE_DECLARE(struct dst_entry *ip6_dst_check(struct dst_entry *,
597 							  u32));
598 INDIRECT_CALLABLE_DECLARE(struct dst_entry *ipv4_dst_check(struct dst_entry *,
599 							   u32));
__sk_dst_check(struct sock * sk,u32 cookie)600 struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie)
601 {
602 	struct dst_entry *dst = __sk_dst_get(sk);
603 
604 	if (dst && READ_ONCE(dst->obsolete) &&
605 	    INDIRECT_CALL_INET(dst->ops->check, ip6_dst_check, ipv4_dst_check,
606 			       dst, cookie) == NULL) {
607 		sk_tx_queue_clear(sk);
608 		WRITE_ONCE(sk->sk_dst_pending_confirm, 0);
609 		RCU_INIT_POINTER(sk->sk_dst_cache, NULL);
610 		dst_release(dst);
611 		return NULL;
612 	}
613 
614 	return dst;
615 }
616 EXPORT_SYMBOL(__sk_dst_check);
617 
sk_dst_check(struct sock * sk,u32 cookie)618 struct dst_entry *sk_dst_check(struct sock *sk, u32 cookie)
619 {
620 	struct dst_entry *dst = sk_dst_get(sk);
621 
622 	if (dst && READ_ONCE(dst->obsolete) &&
623 	    INDIRECT_CALL_INET(dst->ops->check, ip6_dst_check, ipv4_dst_check,
624 			       dst, cookie) == NULL) {
625 		sk_dst_reset(sk);
626 		dst_release(dst);
627 		return NULL;
628 	}
629 
630 	return dst;
631 }
632 EXPORT_SYMBOL(sk_dst_check);
633 
sock_bindtoindex_locked(struct sock * sk,int ifindex)634 static int sock_bindtoindex_locked(struct sock *sk, int ifindex)
635 {
636 	int ret = -ENOPROTOOPT;
637 #ifdef CONFIG_NETDEVICES
638 	struct net *net = sock_net(sk);
639 
640 	/* Sorry... */
641 	ret = -EPERM;
642 	if (sk->sk_bound_dev_if && !ns_capable(net->user_ns, CAP_NET_RAW))
643 		goto out;
644 
645 	ret = -EINVAL;
646 	if (ifindex < 0)
647 		goto out;
648 
649 	/* Paired with all READ_ONCE() done locklessly. */
650 	WRITE_ONCE(sk->sk_bound_dev_if, ifindex);
651 
652 	if (sk->sk_prot->rehash)
653 		sk->sk_prot->rehash(sk);
654 	sk_dst_reset(sk);
655 
656 	ret = 0;
657 
658 out:
659 #endif
660 
661 	return ret;
662 }
663 
sock_bindtoindex(struct sock * sk,int ifindex,bool lock_sk)664 int sock_bindtoindex(struct sock *sk, int ifindex, bool lock_sk)
665 {
666 	int ret;
667 
668 	if (lock_sk)
669 		lock_sock(sk);
670 	ret = sock_bindtoindex_locked(sk, ifindex);
671 	if (lock_sk)
672 		release_sock(sk);
673 
674 	return ret;
675 }
676 EXPORT_SYMBOL(sock_bindtoindex);
677 
sock_setbindtodevice(struct sock * sk,sockptr_t optval,int optlen)678 static int sock_setbindtodevice(struct sock *sk, sockptr_t optval, int optlen)
679 {
680 	int ret = -ENOPROTOOPT;
681 #ifdef CONFIG_NETDEVICES
682 	struct net *net = sock_net(sk);
683 	char devname[IFNAMSIZ];
684 	int index;
685 
686 	ret = -EINVAL;
687 	if (optlen < 0)
688 		goto out;
689 
690 	/* Bind this socket to a particular device like "eth0",
691 	 * as specified in the passed interface name. If the
692 	 * name is "" or the option length is zero the socket
693 	 * is not bound.
694 	 */
695 	if (optlen > IFNAMSIZ - 1)
696 		optlen = IFNAMSIZ - 1;
697 	memset(devname, 0, sizeof(devname));
698 
699 	ret = -EFAULT;
700 	if (copy_from_sockptr(devname, optval, optlen))
701 		goto out;
702 
703 	index = 0;
704 	if (devname[0] != '\0') {
705 		struct net_device *dev;
706 
707 		rcu_read_lock();
708 		dev = dev_get_by_name_rcu(net, devname);
709 		if (dev)
710 			index = dev->ifindex;
711 		rcu_read_unlock();
712 		ret = -ENODEV;
713 		if (!dev)
714 			goto out;
715 	}
716 
717 	sockopt_lock_sock(sk);
718 	ret = sock_bindtoindex_locked(sk, index);
719 	sockopt_release_sock(sk);
720 out:
721 #endif
722 
723 	return ret;
724 }
725 
sock_getbindtodevice(struct sock * sk,sockptr_t optval,sockptr_t optlen,int len)726 static int sock_getbindtodevice(struct sock *sk, sockptr_t optval,
727 				sockptr_t optlen, int len)
728 {
729 	int ret = -ENOPROTOOPT;
730 #ifdef CONFIG_NETDEVICES
731 	int bound_dev_if = READ_ONCE(sk->sk_bound_dev_if);
732 	struct net *net = sock_net(sk);
733 	char devname[IFNAMSIZ];
734 
735 	if (bound_dev_if == 0) {
736 		len = 0;
737 		goto zero;
738 	}
739 
740 	ret = -EINVAL;
741 	if (len < IFNAMSIZ)
742 		goto out;
743 
744 	ret = netdev_get_name(net, devname, bound_dev_if);
745 	if (ret)
746 		goto out;
747 
748 	len = strlen(devname) + 1;
749 
750 	ret = -EFAULT;
751 	if (copy_to_sockptr(optval, devname, len))
752 		goto out;
753 
754 zero:
755 	ret = -EFAULT;
756 	if (copy_to_sockptr(optlen, &len, sizeof(int)))
757 		goto out;
758 
759 	ret = 0;
760 
761 out:
762 #endif
763 
764 	return ret;
765 }
766 
sk_mc_loop(const struct sock * sk)767 bool sk_mc_loop(const struct sock *sk)
768 {
769 	if (dev_recursion_level())
770 		return false;
771 	if (!sk)
772 		return true;
773 	/* IPV6_ADDRFORM can change sk->sk_family under us. */
774 	switch (READ_ONCE(sk->sk_family)) {
775 	case AF_INET:
776 		return inet_test_bit(MC_LOOP, sk);
777 #if IS_ENABLED(CONFIG_IPV6)
778 	case AF_INET6:
779 		return inet6_test_bit(MC6_LOOP, sk);
780 #endif
781 	}
782 	WARN_ON_ONCE(1);
783 	return true;
784 }
785 EXPORT_SYMBOL(sk_mc_loop);
786 
sock_set_reuseaddr(struct sock * sk)787 void sock_set_reuseaddr(struct sock *sk)
788 {
789 	lock_sock(sk);
790 	sk->sk_reuse = SK_CAN_REUSE;
791 	release_sock(sk);
792 }
793 EXPORT_SYMBOL(sock_set_reuseaddr);
794 
sock_set_reuseport(struct sock * sk)795 void sock_set_reuseport(struct sock *sk)
796 {
797 	lock_sock(sk);
798 	sk->sk_reuseport = true;
799 	release_sock(sk);
800 }
801 EXPORT_SYMBOL(sock_set_reuseport);
802 
sock_no_linger(struct sock * sk)803 void sock_no_linger(struct sock *sk)
804 {
805 	lock_sock(sk);
806 	WRITE_ONCE(sk->sk_lingertime, 0);
807 	sock_set_flag(sk, SOCK_LINGER);
808 	release_sock(sk);
809 }
810 EXPORT_SYMBOL(sock_no_linger);
811 
sock_set_priority(struct sock * sk,u32 priority)812 void sock_set_priority(struct sock *sk, u32 priority)
813 {
814 	WRITE_ONCE(sk->sk_priority, priority);
815 }
816 EXPORT_SYMBOL(sock_set_priority);
817 
sock_set_sndtimeo(struct sock * sk,s64 secs)818 void sock_set_sndtimeo(struct sock *sk, s64 secs)
819 {
820 	if (secs && secs < MAX_SCHEDULE_TIMEOUT / HZ - 1)
821 		WRITE_ONCE(sk->sk_sndtimeo, secs * HZ);
822 	else
823 		WRITE_ONCE(sk->sk_sndtimeo, MAX_SCHEDULE_TIMEOUT);
824 }
825 EXPORT_SYMBOL(sock_set_sndtimeo);
826 
__sock_set_timestamps(struct sock * sk,bool val,bool new,bool ns)827 static void __sock_set_timestamps(struct sock *sk, bool val, bool new, bool ns)
828 {
829 	sock_valbool_flag(sk, SOCK_RCVTSTAMP, val);
830 	sock_valbool_flag(sk, SOCK_RCVTSTAMPNS, val && ns);
831 	if (val)  {
832 		sock_valbool_flag(sk, SOCK_TSTAMP_NEW, new);
833 		sock_enable_timestamp(sk, SOCK_TIMESTAMP);
834 	}
835 }
836 
sock_set_timestamp(struct sock * sk,int optname,bool valbool)837 void sock_set_timestamp(struct sock *sk, int optname, bool valbool)
838 {
839 	switch (optname) {
840 	case SO_TIMESTAMP_OLD:
841 		__sock_set_timestamps(sk, valbool, false, false);
842 		break;
843 	case SO_TIMESTAMP_NEW:
844 		__sock_set_timestamps(sk, valbool, true, false);
845 		break;
846 	case SO_TIMESTAMPNS_OLD:
847 		__sock_set_timestamps(sk, valbool, false, true);
848 		break;
849 	case SO_TIMESTAMPNS_NEW:
850 		__sock_set_timestamps(sk, valbool, true, true);
851 		break;
852 	}
853 }
854 
sock_timestamping_bind_phc(struct sock * sk,int phc_index)855 static int sock_timestamping_bind_phc(struct sock *sk, int phc_index)
856 {
857 	struct net *net = sock_net(sk);
858 	struct net_device *dev = NULL;
859 	bool match = false;
860 	int *vclock_index;
861 	int i, num;
862 
863 	if (sk->sk_bound_dev_if)
864 		dev = dev_get_by_index(net, sk->sk_bound_dev_if);
865 
866 	if (!dev) {
867 		pr_err("%s: sock not bind to device\n", __func__);
868 		return -EOPNOTSUPP;
869 	}
870 
871 	num = ethtool_get_phc_vclocks(dev, &vclock_index);
872 	dev_put(dev);
873 
874 	for (i = 0; i < num; i++) {
875 		if (*(vclock_index + i) == phc_index) {
876 			match = true;
877 			break;
878 		}
879 	}
880 
881 	if (num > 0)
882 		kfree(vclock_index);
883 
884 	if (!match)
885 		return -EINVAL;
886 
887 	WRITE_ONCE(sk->sk_bind_phc, phc_index);
888 
889 	return 0;
890 }
891 
sock_set_timestamping(struct sock * sk,int optname,struct so_timestamping timestamping)892 int sock_set_timestamping(struct sock *sk, int optname,
893 			  struct so_timestamping timestamping)
894 {
895 	int val = timestamping.flags;
896 	int ret;
897 
898 	if (val & ~SOF_TIMESTAMPING_MASK)
899 		return -EINVAL;
900 
901 	if (val & SOF_TIMESTAMPING_OPT_ID_TCP &&
902 	    !(val & SOF_TIMESTAMPING_OPT_ID))
903 		return -EINVAL;
904 
905 	if (val & SOF_TIMESTAMPING_OPT_ID &&
906 	    !(sk->sk_tsflags & SOF_TIMESTAMPING_OPT_ID)) {
907 		if (sk_is_tcp(sk)) {
908 			if ((1 << sk->sk_state) &
909 			    (TCPF_CLOSE | TCPF_LISTEN))
910 				return -EINVAL;
911 			if (val & SOF_TIMESTAMPING_OPT_ID_TCP)
912 				atomic_set(&sk->sk_tskey, tcp_sk(sk)->write_seq);
913 			else
914 				atomic_set(&sk->sk_tskey, tcp_sk(sk)->snd_una);
915 		} else {
916 			atomic_set(&sk->sk_tskey, 0);
917 		}
918 	}
919 
920 	if (val & SOF_TIMESTAMPING_OPT_STATS &&
921 	    !(val & SOF_TIMESTAMPING_OPT_TSONLY))
922 		return -EINVAL;
923 
924 	if (val & SOF_TIMESTAMPING_BIND_PHC) {
925 		ret = sock_timestamping_bind_phc(sk, timestamping.bind_phc);
926 		if (ret)
927 			return ret;
928 	}
929 
930 	WRITE_ONCE(sk->sk_tsflags, val);
931 	sock_valbool_flag(sk, SOCK_TSTAMP_NEW, optname == SO_TIMESTAMPING_NEW);
932 	sock_valbool_flag(sk, SOCK_TIMESTAMPING_ANY, !!(val & TSFLAGS_ANY));
933 
934 	if (val & SOF_TIMESTAMPING_RX_SOFTWARE)
935 		sock_enable_timestamp(sk,
936 				      SOCK_TIMESTAMPING_RX_SOFTWARE);
937 	else
938 		sock_disable_timestamp(sk,
939 				       (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE));
940 	return 0;
941 }
942 
943 #if defined(CONFIG_CGROUP_BPF)
bpf_skops_tx_timestamping(struct sock * sk,struct sk_buff * skb,int op)944 void bpf_skops_tx_timestamping(struct sock *sk, struct sk_buff *skb, int op)
945 {
946 	struct bpf_sock_ops_kern sock_ops;
947 
948 	memset(&sock_ops, 0, offsetof(struct bpf_sock_ops_kern, temp));
949 	sock_ops.op = op;
950 	sock_ops.is_fullsock = 1;
951 	sock_ops.sk = sk;
952 	bpf_skops_init_skb(&sock_ops, skb, 0);
953 	__cgroup_bpf_run_filter_sock_ops(sk, &sock_ops, CGROUP_SOCK_OPS);
954 }
955 #endif
956 
sock_set_keepalive(struct sock * sk)957 void sock_set_keepalive(struct sock *sk)
958 {
959 	lock_sock(sk);
960 	if (sk->sk_prot->keepalive)
961 		sk->sk_prot->keepalive(sk, true);
962 	sock_valbool_flag(sk, SOCK_KEEPOPEN, true);
963 	release_sock(sk);
964 }
965 EXPORT_SYMBOL(sock_set_keepalive);
966 
__sock_set_rcvbuf(struct sock * sk,int val)967 static void __sock_set_rcvbuf(struct sock *sk, int val)
968 {
969 	struct socket *sock = sk->sk_socket;
970 
971 	/* Ensure val * 2 fits into an int, to prevent max_t() from treating it
972 	 * as a negative value.
973 	 */
974 	val = min_t(int, val, INT_MAX / 2);
975 	sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
976 
977 	/* We double it on the way in to account for "struct sk_buff" etc.
978 	 * overhead.   Applications assume that the SO_RCVBUF setting they make
979 	 * will allow that much actual data to be received on that socket.
980 	 *
981 	 * Applications are unaware that "struct sk_buff" and other overheads
982 	 * allocate from the receive buffer during socket buffer allocation.
983 	 *
984 	 * And after considering the possible alternatives, returning the value
985 	 * we actually used in getsockopt is the most desirable behavior.
986 	 */
987 	WRITE_ONCE(sk->sk_rcvbuf, max_t(int, val * 2, SOCK_MIN_RCVBUF));
988 
989 	if (sock) {
990 		const struct proto_ops *ops = READ_ONCE(sock->ops);
991 
992 		if (ops->set_rcvbuf)
993 			ops->set_rcvbuf(sk, sk->sk_rcvbuf);
994 	}
995 }
996 
sock_set_rcvbuf(struct sock * sk,int val)997 void sock_set_rcvbuf(struct sock *sk, int val)
998 {
999 	lock_sock(sk);
1000 	__sock_set_rcvbuf(sk, val);
1001 	release_sock(sk);
1002 }
1003 EXPORT_SYMBOL(sock_set_rcvbuf);
1004 
__sock_set_mark(struct sock * sk,u32 val)1005 static void __sock_set_mark(struct sock *sk, u32 val)
1006 {
1007 	if (val != sk->sk_mark) {
1008 		WRITE_ONCE(sk->sk_mark, val);
1009 		sk_dst_reset(sk);
1010 	}
1011 }
1012 
sock_set_mark(struct sock * sk,u32 val)1013 void sock_set_mark(struct sock *sk, u32 val)
1014 {
1015 	lock_sock(sk);
1016 	__sock_set_mark(sk, val);
1017 	release_sock(sk);
1018 }
1019 EXPORT_SYMBOL(sock_set_mark);
1020 
sock_release_reserved_memory(struct sock * sk,int bytes)1021 static void sock_release_reserved_memory(struct sock *sk, int bytes)
1022 {
1023 	/* Round down bytes to multiple of pages */
1024 	bytes = round_down(bytes, PAGE_SIZE);
1025 
1026 	WARN_ON(bytes > sk->sk_reserved_mem);
1027 	WRITE_ONCE(sk->sk_reserved_mem, sk->sk_reserved_mem - bytes);
1028 	sk_mem_reclaim(sk);
1029 }
1030 
sock_reserve_memory(struct sock * sk,int bytes)1031 static int sock_reserve_memory(struct sock *sk, int bytes)
1032 {
1033 	long allocated;
1034 	bool charged;
1035 	int pages;
1036 
1037 	if (!mem_cgroup_sk_enabled(sk) || !sk_has_account(sk))
1038 		return -EOPNOTSUPP;
1039 
1040 	if (!bytes)
1041 		return 0;
1042 
1043 	pages = sk_mem_pages(bytes);
1044 
1045 	/* pre-charge to memcg */
1046 	charged = mem_cgroup_sk_charge(sk, pages,
1047 				       GFP_KERNEL | __GFP_RETRY_MAYFAIL);
1048 	if (!charged)
1049 		return -ENOMEM;
1050 
1051 	if (sk->sk_bypass_prot_mem)
1052 		goto success;
1053 
1054 	/* pre-charge to forward_alloc */
1055 	sk_memory_allocated_add(sk, pages);
1056 	allocated = sk_memory_allocated(sk);
1057 
1058 	/* If the system goes into memory pressure with this
1059 	 * precharge, give up and return error.
1060 	 */
1061 	if (allocated > sk_prot_mem_limits(sk, 1)) {
1062 		sk_memory_allocated_sub(sk, pages);
1063 		mem_cgroup_sk_uncharge(sk, pages);
1064 		return -ENOMEM;
1065 	}
1066 
1067 success:
1068 	sk_forward_alloc_add(sk, pages << PAGE_SHIFT);
1069 
1070 	WRITE_ONCE(sk->sk_reserved_mem,
1071 		   sk->sk_reserved_mem + (pages << PAGE_SHIFT));
1072 
1073 	return 0;
1074 }
1075 
1076 #ifdef CONFIG_PAGE_POOL
1077 
1078 /* This is the number of tokens and frags that the user can SO_DEVMEM_DONTNEED
1079  * in 1 syscall. The limit exists to limit the amount of memory the kernel
1080  * allocates to copy these tokens, and to prevent looping over the frags for
1081  * too long.
1082  */
1083 #define MAX_DONTNEED_TOKENS 128
1084 #define MAX_DONTNEED_FRAGS 1024
1085 
1086 static noinline_for_stack int
sock_devmem_dontneed(struct sock * sk,sockptr_t optval,unsigned int optlen)1087 sock_devmem_dontneed(struct sock *sk, sockptr_t optval, unsigned int optlen)
1088 {
1089 	unsigned int num_tokens, i, j, k, netmem_num = 0;
1090 	struct dmabuf_token *tokens;
1091 	int ret = 0, num_frags = 0;
1092 	netmem_ref netmems[16];
1093 
1094 	if (!sk_is_tcp(sk))
1095 		return -EBADF;
1096 
1097 	if (optlen % sizeof(*tokens) ||
1098 	    optlen > sizeof(*tokens) * MAX_DONTNEED_TOKENS)
1099 		return -EINVAL;
1100 
1101 	num_tokens = optlen / sizeof(*tokens);
1102 	tokens = kvmalloc_objs(*tokens, num_tokens);
1103 	if (!tokens)
1104 		return -ENOMEM;
1105 
1106 	if (copy_from_sockptr(tokens, optval, optlen)) {
1107 		kvfree(tokens);
1108 		return -EFAULT;
1109 	}
1110 
1111 	xa_lock_bh(&sk->sk_user_frags);
1112 	for (i = 0; i < num_tokens; i++) {
1113 		for (j = 0; j < tokens[i].token_count; j++) {
1114 			if (++num_frags > MAX_DONTNEED_FRAGS)
1115 				goto frag_limit_reached;
1116 
1117 			netmem_ref netmem = (__force netmem_ref)__xa_erase(
1118 				&sk->sk_user_frags, tokens[i].token_start + j);
1119 
1120 			if (!netmem || WARN_ON_ONCE(!netmem_is_net_iov(netmem)))
1121 				continue;
1122 
1123 			netmems[netmem_num++] = netmem;
1124 			if (netmem_num == ARRAY_SIZE(netmems)) {
1125 				xa_unlock_bh(&sk->sk_user_frags);
1126 				for (k = 0; k < netmem_num; k++)
1127 					WARN_ON_ONCE(!napi_pp_put_page(netmems[k]));
1128 				netmem_num = 0;
1129 				xa_lock_bh(&sk->sk_user_frags);
1130 			}
1131 			ret++;
1132 		}
1133 	}
1134 
1135 frag_limit_reached:
1136 	xa_unlock_bh(&sk->sk_user_frags);
1137 	for (k = 0; k < netmem_num; k++)
1138 		WARN_ON_ONCE(!napi_pp_put_page(netmems[k]));
1139 
1140 	kvfree(tokens);
1141 	return ret;
1142 }
1143 #endif
1144 
sockopt_lock_sock(struct sock * sk)1145 void sockopt_lock_sock(struct sock *sk)
1146 {
1147 	/* When current->bpf_ctx is set, the setsockopt is called from
1148 	 * a bpf prog.  bpf has ensured the sk lock has been
1149 	 * acquired before calling setsockopt().
1150 	 */
1151 	if (has_current_bpf_ctx())
1152 		return;
1153 
1154 	lock_sock(sk);
1155 }
1156 EXPORT_SYMBOL(sockopt_lock_sock);
1157 
sockopt_release_sock(struct sock * sk)1158 void sockopt_release_sock(struct sock *sk)
1159 {
1160 	if (has_current_bpf_ctx())
1161 		return;
1162 
1163 	release_sock(sk);
1164 }
1165 EXPORT_SYMBOL(sockopt_release_sock);
1166 
sockopt_ns_capable(struct user_namespace * ns,int cap)1167 bool sockopt_ns_capable(struct user_namespace *ns, int cap)
1168 {
1169 	return has_current_bpf_ctx() || ns_capable(ns, cap);
1170 }
1171 EXPORT_SYMBOL(sockopt_ns_capable);
1172 
sockopt_capable(int cap)1173 bool sockopt_capable(int cap)
1174 {
1175 	return has_current_bpf_ctx() || capable(cap);
1176 }
1177 EXPORT_SYMBOL(sockopt_capable);
1178 
sockopt_validate_clockid(__kernel_clockid_t value)1179 static int sockopt_validate_clockid(__kernel_clockid_t value)
1180 {
1181 	switch (value) {
1182 	case CLOCK_REALTIME:
1183 	case CLOCK_MONOTONIC:
1184 	case CLOCK_TAI:
1185 		return 0;
1186 	}
1187 	return -EINVAL;
1188 }
1189 
1190 /*
1191  *	This is meant for all protocols to use and covers goings on
1192  *	at the socket level. Everything here is generic.
1193  */
1194 
sk_setsockopt(struct sock * sk,int level,int optname,sockptr_t optval,unsigned int optlen)1195 int sk_setsockopt(struct sock *sk, int level, int optname,
1196 		  sockptr_t optval, unsigned int optlen)
1197 {
1198 	struct so_timestamping timestamping;
1199 	struct socket *sock = sk->sk_socket;
1200 	struct sock_txtime sk_txtime;
1201 	int val;
1202 	int valbool;
1203 	struct linger ling;
1204 	int ret = 0;
1205 
1206 	/*
1207 	 *	Options without arguments
1208 	 */
1209 
1210 	if (optname == SO_BINDTODEVICE)
1211 		return sock_setbindtodevice(sk, optval, optlen);
1212 
1213 	if (optlen < sizeof(int))
1214 		return -EINVAL;
1215 
1216 	if (copy_from_sockptr(&val, optval, sizeof(val)))
1217 		return -EFAULT;
1218 
1219 	valbool = val ? 1 : 0;
1220 
1221 	/* handle options which do not require locking the socket. */
1222 	switch (optname) {
1223 	case SO_PRIORITY:
1224 		if (sk_set_prio_allowed(sk, val)) {
1225 			sock_set_priority(sk, val);
1226 			return 0;
1227 		}
1228 		return -EPERM;
1229 	case SO_TYPE:
1230 	case SO_PROTOCOL:
1231 	case SO_DOMAIN:
1232 	case SO_ERROR:
1233 		return -ENOPROTOOPT;
1234 #ifdef CONFIG_NET_RX_BUSY_POLL
1235 	case SO_BUSY_POLL:
1236 		if (val < 0)
1237 			return -EINVAL;
1238 		WRITE_ONCE(sk->sk_ll_usec, val);
1239 		return 0;
1240 	case SO_PREFER_BUSY_POLL:
1241 		if (valbool && !sockopt_capable(CAP_NET_ADMIN))
1242 			return -EPERM;
1243 		WRITE_ONCE(sk->sk_prefer_busy_poll, valbool);
1244 		return 0;
1245 	case SO_BUSY_POLL_BUDGET:
1246 		if (val > READ_ONCE(sk->sk_busy_poll_budget) &&
1247 		    !sockopt_capable(CAP_NET_ADMIN))
1248 			return -EPERM;
1249 		if (val < 0 || val > U16_MAX)
1250 			return -EINVAL;
1251 		WRITE_ONCE(sk->sk_busy_poll_budget, val);
1252 		return 0;
1253 #endif
1254 	case SO_MAX_PACING_RATE:
1255 		{
1256 		unsigned long ulval = (val == ~0U) ? ~0UL : (unsigned int)val;
1257 		unsigned long pacing_rate;
1258 
1259 		if (sizeof(ulval) != sizeof(val) &&
1260 		    optlen >= sizeof(ulval) &&
1261 		    copy_from_sockptr(&ulval, optval, sizeof(ulval))) {
1262 			return -EFAULT;
1263 		}
1264 		if (ulval != ~0UL)
1265 			cmpxchg(&sk->sk_pacing_status,
1266 				SK_PACING_NONE,
1267 				SK_PACING_NEEDED);
1268 		/* Pairs with READ_ONCE() from sk_getsockopt() */
1269 		WRITE_ONCE(sk->sk_max_pacing_rate, ulval);
1270 		pacing_rate = READ_ONCE(sk->sk_pacing_rate);
1271 		if (ulval < pacing_rate)
1272 			WRITE_ONCE(sk->sk_pacing_rate, ulval);
1273 		return 0;
1274 		}
1275 	case SO_TXREHASH:
1276 		if (!sk_is_tcp(sk))
1277 			return -EOPNOTSUPP;
1278 		if (val < -1 || val > 1)
1279 			return -EINVAL;
1280 		if ((u8)val == SOCK_TXREHASH_DEFAULT)
1281 			val = READ_ONCE(sock_net(sk)->core.sysctl_txrehash);
1282 		/* Paired with READ_ONCE() in tcp_rtx_synack()
1283 		 * and sk_getsockopt().
1284 		 */
1285 		WRITE_ONCE(sk->sk_txrehash, (u8)val);
1286 		return 0;
1287 	case SO_PEEK_OFF:
1288 		{
1289 		int (*set_peek_off)(struct sock *sk, int val);
1290 
1291 		set_peek_off = READ_ONCE(sock->ops)->set_peek_off;
1292 		if (set_peek_off)
1293 			ret = set_peek_off(sk, val);
1294 		else
1295 			ret = -EOPNOTSUPP;
1296 		return ret;
1297 		}
1298 #ifdef CONFIG_PAGE_POOL
1299 	case SO_DEVMEM_DONTNEED:
1300 		return sock_devmem_dontneed(sk, optval, optlen);
1301 #endif
1302 	case SO_SNDTIMEO_OLD:
1303 	case SO_SNDTIMEO_NEW:
1304 		return sock_set_timeout(&sk->sk_sndtimeo, optval,
1305 					optlen, optname == SO_SNDTIMEO_OLD);
1306 	case SO_RCVTIMEO_OLD:
1307 	case SO_RCVTIMEO_NEW:
1308 		return sock_set_timeout(&sk->sk_rcvtimeo, optval,
1309 					optlen, optname == SO_RCVTIMEO_OLD);
1310 	}
1311 
1312 	sockopt_lock_sock(sk);
1313 
1314 	switch (optname) {
1315 	case SO_DEBUG:
1316 		if (val && !sockopt_capable(CAP_NET_ADMIN))
1317 			ret = -EACCES;
1318 		else
1319 			sock_valbool_flag(sk, SOCK_DBG, valbool);
1320 		break;
1321 	case SO_REUSEADDR:
1322 		sk->sk_reuse = (valbool ? SK_CAN_REUSE : SK_NO_REUSE);
1323 		break;
1324 	case SO_REUSEPORT:
1325 		if (valbool && !sk_is_inet(sk))
1326 			ret = -EOPNOTSUPP;
1327 		else
1328 			sk->sk_reuseport = valbool;
1329 		break;
1330 	case SO_DONTROUTE:
1331 		sock_valbool_flag(sk, SOCK_LOCALROUTE, valbool);
1332 		sk_dst_reset(sk);
1333 		break;
1334 	case SO_BROADCAST:
1335 		sock_valbool_flag(sk, SOCK_BROADCAST, valbool);
1336 		break;
1337 	case SO_SNDBUF:
1338 		/* Don't error on this BSD doesn't and if you think
1339 		 * about it this is right. Otherwise apps have to
1340 		 * play 'guess the biggest size' games. RCVBUF/SNDBUF
1341 		 * are treated in BSD as hints
1342 		 */
1343 		val = min_t(u32, val, READ_ONCE(sysctl_wmem_max));
1344 set_sndbuf:
1345 		/* Ensure val * 2 fits into an int, to prevent max_t()
1346 		 * from treating it as a negative value.
1347 		 */
1348 		val = min_t(int, val, INT_MAX / 2);
1349 		sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
1350 		WRITE_ONCE(sk->sk_sndbuf,
1351 			   max_t(int, val * 2, SOCK_MIN_SNDBUF));
1352 		/* Wake up sending tasks if we upped the value. */
1353 		sk->sk_write_space(sk);
1354 		break;
1355 
1356 	case SO_SNDBUFFORCE:
1357 		if (!sockopt_capable(CAP_NET_ADMIN)) {
1358 			ret = -EPERM;
1359 			break;
1360 		}
1361 
1362 		/* No negative values (to prevent underflow, as val will be
1363 		 * multiplied by 2).
1364 		 */
1365 		if (val < 0)
1366 			val = 0;
1367 		goto set_sndbuf;
1368 
1369 	case SO_RCVBUF:
1370 		/* Don't error on this BSD doesn't and if you think
1371 		 * about it this is right. Otherwise apps have to
1372 		 * play 'guess the biggest size' games. RCVBUF/SNDBUF
1373 		 * are treated in BSD as hints
1374 		 */
1375 		__sock_set_rcvbuf(sk, min_t(u32, val, READ_ONCE(sysctl_rmem_max)));
1376 		break;
1377 
1378 	case SO_RCVBUFFORCE:
1379 		if (!sockopt_capable(CAP_NET_ADMIN)) {
1380 			ret = -EPERM;
1381 			break;
1382 		}
1383 
1384 		/* No negative values (to prevent underflow, as val will be
1385 		 * multiplied by 2).
1386 		 */
1387 		__sock_set_rcvbuf(sk, max(val, 0));
1388 		break;
1389 
1390 	case SO_KEEPALIVE:
1391 		if (sk->sk_prot->keepalive)
1392 			sk->sk_prot->keepalive(sk, valbool);
1393 		sock_valbool_flag(sk, SOCK_KEEPOPEN, valbool);
1394 		break;
1395 
1396 	case SO_OOBINLINE:
1397 		sock_valbool_flag(sk, SOCK_URGINLINE, valbool);
1398 		break;
1399 
1400 	case SO_NO_CHECK:
1401 		sk->sk_no_check_tx = valbool;
1402 		break;
1403 
1404 	case SO_LINGER:
1405 		if (optlen < sizeof(ling)) {
1406 			ret = -EINVAL;	/* 1003.1g */
1407 			break;
1408 		}
1409 		if (copy_from_sockptr(&ling, optval, sizeof(ling))) {
1410 			ret = -EFAULT;
1411 			break;
1412 		}
1413 		if (!ling.l_onoff) {
1414 			sock_reset_flag(sk, SOCK_LINGER);
1415 		} else {
1416 			unsigned long t_sec = ling.l_linger;
1417 
1418 			if (t_sec >= MAX_SCHEDULE_TIMEOUT / HZ)
1419 				WRITE_ONCE(sk->sk_lingertime, MAX_SCHEDULE_TIMEOUT);
1420 			else
1421 				WRITE_ONCE(sk->sk_lingertime, t_sec * HZ);
1422 			sock_set_flag(sk, SOCK_LINGER);
1423 		}
1424 		break;
1425 
1426 	case SO_BSDCOMPAT:
1427 		break;
1428 
1429 	case SO_TIMESTAMP_OLD:
1430 	case SO_TIMESTAMP_NEW:
1431 	case SO_TIMESTAMPNS_OLD:
1432 	case SO_TIMESTAMPNS_NEW:
1433 		sock_set_timestamp(sk, optname, valbool);
1434 		break;
1435 
1436 	case SO_TIMESTAMPING_NEW:
1437 	case SO_TIMESTAMPING_OLD:
1438 		if (optlen == sizeof(timestamping)) {
1439 			if (copy_from_sockptr(&timestamping, optval,
1440 					      sizeof(timestamping))) {
1441 				ret = -EFAULT;
1442 				break;
1443 			}
1444 		} else {
1445 			memset(&timestamping, 0, sizeof(timestamping));
1446 			timestamping.flags = val;
1447 		}
1448 		ret = sock_set_timestamping(sk, optname, timestamping);
1449 		break;
1450 
1451 	case SO_RCVLOWAT:
1452 		{
1453 		int (*set_rcvlowat)(struct sock *sk, int val) = NULL;
1454 
1455 		if (val < 0)
1456 			val = INT_MAX;
1457 		if (sock)
1458 			set_rcvlowat = READ_ONCE(sock->ops)->set_rcvlowat;
1459 		if (set_rcvlowat)
1460 			ret = set_rcvlowat(sk, val);
1461 		else
1462 			WRITE_ONCE(sk->sk_rcvlowat, val ? : 1);
1463 		break;
1464 		}
1465 	case SO_ATTACH_FILTER: {
1466 		struct sock_fprog fprog;
1467 
1468 		ret = copy_bpf_fprog_from_user(&fprog, optval, optlen);
1469 		if (!ret)
1470 			ret = sk_attach_filter(&fprog, sk);
1471 		break;
1472 	}
1473 	case SO_ATTACH_BPF:
1474 		ret = -EINVAL;
1475 		if (optlen == sizeof(u32)) {
1476 			u32 ufd;
1477 
1478 			ret = -EFAULT;
1479 			if (copy_from_sockptr(&ufd, optval, sizeof(ufd)))
1480 				break;
1481 
1482 			ret = sk_attach_bpf(ufd, sk);
1483 		}
1484 		break;
1485 
1486 	case SO_ATTACH_REUSEPORT_CBPF: {
1487 		struct sock_fprog fprog;
1488 
1489 		ret = copy_bpf_fprog_from_user(&fprog, optval, optlen);
1490 		if (!ret)
1491 			ret = sk_reuseport_attach_filter(&fprog, sk);
1492 		break;
1493 	}
1494 	case SO_ATTACH_REUSEPORT_EBPF:
1495 		ret = -EINVAL;
1496 		if (optlen == sizeof(u32)) {
1497 			u32 ufd;
1498 
1499 			ret = -EFAULT;
1500 			if (copy_from_sockptr(&ufd, optval, sizeof(ufd)))
1501 				break;
1502 
1503 			ret = sk_reuseport_attach_bpf(ufd, sk);
1504 		}
1505 		break;
1506 
1507 	case SO_DETACH_REUSEPORT_BPF:
1508 		ret = reuseport_detach_prog(sk);
1509 		break;
1510 
1511 	case SO_DETACH_FILTER:
1512 		ret = sk_detach_filter(sk);
1513 		break;
1514 
1515 	case SO_LOCK_FILTER:
1516 		if (sock_flag(sk, SOCK_FILTER_LOCKED) && !valbool)
1517 			ret = -EPERM;
1518 		else
1519 			sock_valbool_flag(sk, SOCK_FILTER_LOCKED, valbool);
1520 		break;
1521 
1522 	case SO_MARK:
1523 		if (!sockopt_ns_capable(sock_net(sk)->user_ns, CAP_NET_RAW) &&
1524 		    !sockopt_ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) {
1525 			ret = -EPERM;
1526 			break;
1527 		}
1528 
1529 		__sock_set_mark(sk, val);
1530 		break;
1531 	case SO_RCVMARK:
1532 		sock_valbool_flag(sk, SOCK_RCVMARK, valbool);
1533 		break;
1534 
1535 	case SO_RCVPRIORITY:
1536 		sock_valbool_flag(sk, SOCK_RCVPRIORITY, valbool);
1537 		break;
1538 
1539 	case SO_RXQ_OVFL:
1540 		sock_valbool_flag(sk, SOCK_RXQ_OVFL, valbool);
1541 		break;
1542 
1543 	case SO_WIFI_STATUS:
1544 		sock_valbool_flag(sk, SOCK_WIFI_STATUS, valbool);
1545 		break;
1546 
1547 	case SO_NOFCS:
1548 		sock_valbool_flag(sk, SOCK_NOFCS, valbool);
1549 		break;
1550 
1551 	case SO_SELECT_ERR_QUEUE:
1552 		sock_valbool_flag(sk, SOCK_SELECT_ERR_QUEUE, valbool);
1553 		break;
1554 
1555 	case SO_PASSCRED:
1556 		if (sk_may_scm_recv(sk))
1557 			sk->sk_scm_credentials = valbool;
1558 		else
1559 			ret = -EOPNOTSUPP;
1560 		break;
1561 
1562 	case SO_PASSSEC:
1563 		if (IS_ENABLED(CONFIG_SECURITY_NETWORK) && sk_may_scm_recv(sk))
1564 			sk->sk_scm_security = valbool;
1565 		else
1566 			ret = -EOPNOTSUPP;
1567 		break;
1568 
1569 	case SO_PASSPIDFD:
1570 		if (sk_is_unix(sk))
1571 			sk->sk_scm_pidfd = valbool;
1572 		else
1573 			ret = -EOPNOTSUPP;
1574 		break;
1575 
1576 	case SO_PASSRIGHTS:
1577 		if (sk_is_unix(sk))
1578 			sk->sk_scm_rights = valbool;
1579 		else
1580 			ret = -EOPNOTSUPP;
1581 		break;
1582 
1583 	case SO_INCOMING_CPU:
1584 		reuseport_update_incoming_cpu(sk, val);
1585 		break;
1586 
1587 	case SO_CNX_ADVICE:
1588 		if (val == 1)
1589 			dst_negative_advice(sk);
1590 		break;
1591 
1592 	case SO_ZEROCOPY:
1593 		if (sk->sk_family == PF_INET || sk->sk_family == PF_INET6) {
1594 			if (!(sk_is_tcp(sk) ||
1595 			      (sk->sk_type == SOCK_DGRAM &&
1596 			       sk->sk_protocol == IPPROTO_UDP)))
1597 				ret = -EOPNOTSUPP;
1598 		} else if (sk->sk_family != PF_RDS) {
1599 			ret = -EOPNOTSUPP;
1600 		}
1601 		if (!ret) {
1602 			if (val < 0 || val > 1)
1603 				ret = -EINVAL;
1604 			else
1605 				sock_valbool_flag(sk, SOCK_ZEROCOPY, valbool);
1606 		}
1607 		break;
1608 
1609 	case SO_TXTIME:
1610 		if (optlen != sizeof(struct sock_txtime)) {
1611 			ret = -EINVAL;
1612 			break;
1613 		} else if (copy_from_sockptr(&sk_txtime, optval,
1614 			   sizeof(struct sock_txtime))) {
1615 			ret = -EFAULT;
1616 			break;
1617 		} else if (sk_txtime.flags & ~SOF_TXTIME_FLAGS_MASK) {
1618 			ret = -EINVAL;
1619 			break;
1620 		}
1621 		/* CLOCK_MONOTONIC is only used by sch_fq, and this packet
1622 		 * scheduler has enough safe guards.
1623 		 */
1624 		if (sk_txtime.clockid != CLOCK_MONOTONIC &&
1625 		    !sockopt_ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) {
1626 			ret = -EPERM;
1627 			break;
1628 		}
1629 
1630 		ret = sockopt_validate_clockid(sk_txtime.clockid);
1631 		if (ret)
1632 			break;
1633 
1634 		sock_valbool_flag(sk, SOCK_TXTIME, true);
1635 		sk->sk_clockid = sk_txtime.clockid;
1636 		sk->sk_txtime_deadline_mode =
1637 			!!(sk_txtime.flags & SOF_TXTIME_DEADLINE_MODE);
1638 		sk->sk_txtime_report_errors =
1639 			!!(sk_txtime.flags & SOF_TXTIME_REPORT_ERRORS);
1640 		break;
1641 
1642 	case SO_BINDTOIFINDEX:
1643 		ret = sock_bindtoindex_locked(sk, val);
1644 		break;
1645 
1646 	case SO_BUF_LOCK:
1647 		if (val & ~SOCK_BUF_LOCK_MASK) {
1648 			ret = -EINVAL;
1649 			break;
1650 		}
1651 		sk->sk_userlocks = val | (sk->sk_userlocks &
1652 					  ~SOCK_BUF_LOCK_MASK);
1653 		break;
1654 
1655 	case SO_RESERVE_MEM:
1656 	{
1657 		int delta;
1658 
1659 		if (val < 0) {
1660 			ret = -EINVAL;
1661 			break;
1662 		}
1663 
1664 		delta = val - sk->sk_reserved_mem;
1665 		if (delta < 0)
1666 			sock_release_reserved_memory(sk, -delta);
1667 		else
1668 			ret = sock_reserve_memory(sk, delta);
1669 		break;
1670 	}
1671 
1672 	default:
1673 		ret = -ENOPROTOOPT;
1674 		break;
1675 	}
1676 	sockopt_release_sock(sk);
1677 	return ret;
1678 }
1679 
sock_setsockopt(struct socket * sock,int level,int optname,sockptr_t optval,unsigned int optlen)1680 int sock_setsockopt(struct socket *sock, int level, int optname,
1681 		    sockptr_t optval, unsigned int optlen)
1682 {
1683 	return sk_setsockopt(sock->sk, level, optname,
1684 			     optval, optlen);
1685 }
1686 EXPORT_SYMBOL(sock_setsockopt);
1687 
sk_get_peer_cred(struct sock * sk)1688 static const struct cred *sk_get_peer_cred(struct sock *sk)
1689 {
1690 	const struct cred *cred;
1691 
1692 	spin_lock(&sk->sk_peer_lock);
1693 	cred = get_cred(sk->sk_peer_cred);
1694 	spin_unlock(&sk->sk_peer_lock);
1695 
1696 	return cred;
1697 }
1698 
cred_to_ucred(struct pid * pid,const struct cred * cred,struct ucred * ucred)1699 static void cred_to_ucred(struct pid *pid, const struct cred *cred,
1700 			  struct ucred *ucred)
1701 {
1702 	ucred->pid = pid_vnr(pid);
1703 	ucred->uid = ucred->gid = -1;
1704 	if (cred) {
1705 		struct user_namespace *current_ns = current_user_ns();
1706 
1707 		ucred->uid = from_kuid_munged(current_ns, cred->euid);
1708 		ucred->gid = from_kgid_munged(current_ns, cred->egid);
1709 	}
1710 }
1711 
groups_to_user(sockptr_t dst,const struct group_info * src)1712 static int groups_to_user(sockptr_t dst, const struct group_info *src)
1713 {
1714 	struct user_namespace *user_ns = current_user_ns();
1715 	int i;
1716 
1717 	for (i = 0; i < src->ngroups; i++) {
1718 		gid_t gid = from_kgid_munged(user_ns, src->gid[i]);
1719 
1720 		if (copy_to_sockptr_offset(dst, i * sizeof(gid), &gid, sizeof(gid)))
1721 			return -EFAULT;
1722 	}
1723 
1724 	return 0;
1725 }
1726 
sk_getsockopt(struct sock * sk,int level,int optname,sockptr_t optval,sockptr_t optlen)1727 int sk_getsockopt(struct sock *sk, int level, int optname,
1728 		  sockptr_t optval, sockptr_t optlen)
1729 {
1730 	struct socket *sock = sk->sk_socket;
1731 
1732 	union {
1733 		int val;
1734 		u64 val64;
1735 		unsigned long ulval;
1736 		struct linger ling;
1737 		struct old_timeval32 tm32;
1738 		struct __kernel_old_timeval tm;
1739 		struct  __kernel_sock_timeval stm;
1740 		struct sock_txtime txtime;
1741 		struct so_timestamping timestamping;
1742 	} v;
1743 
1744 	int lv = sizeof(int);
1745 	int len;
1746 
1747 	if (copy_from_sockptr(&len, optlen, sizeof(int)))
1748 		return -EFAULT;
1749 	if (len < 0)
1750 		return -EINVAL;
1751 
1752 	memset(&v, 0, sizeof(v));
1753 
1754 	switch (optname) {
1755 	case SO_DEBUG:
1756 		v.val = sock_flag(sk, SOCK_DBG);
1757 		break;
1758 
1759 	case SO_DONTROUTE:
1760 		v.val = sock_flag(sk, SOCK_LOCALROUTE);
1761 		break;
1762 
1763 	case SO_BROADCAST:
1764 		v.val = sock_flag(sk, SOCK_BROADCAST);
1765 		break;
1766 
1767 	case SO_SNDBUF:
1768 		v.val = READ_ONCE(sk->sk_sndbuf);
1769 		break;
1770 
1771 	case SO_RCVBUF:
1772 		v.val = READ_ONCE(sk->sk_rcvbuf);
1773 		break;
1774 
1775 	case SO_REUSEADDR:
1776 		v.val = sk->sk_reuse;
1777 		break;
1778 
1779 	case SO_REUSEPORT:
1780 		v.val = sk->sk_reuseport;
1781 		break;
1782 
1783 	case SO_KEEPALIVE:
1784 		v.val = sock_flag(sk, SOCK_KEEPOPEN);
1785 		break;
1786 
1787 	case SO_TYPE:
1788 		v.val = sk->sk_type;
1789 		break;
1790 
1791 	case SO_PROTOCOL:
1792 		v.val = sk->sk_protocol;
1793 		break;
1794 
1795 	case SO_DOMAIN:
1796 		v.val = sk->sk_family;
1797 		break;
1798 
1799 	case SO_ERROR:
1800 		v.val = -sock_error(sk);
1801 		if (v.val == 0)
1802 			v.val = xchg(&sk->sk_err_soft, 0);
1803 		break;
1804 
1805 	case SO_OOBINLINE:
1806 		v.val = sock_flag(sk, SOCK_URGINLINE);
1807 		break;
1808 
1809 	case SO_NO_CHECK:
1810 		v.val = sk->sk_no_check_tx;
1811 		break;
1812 
1813 	case SO_PRIORITY:
1814 		v.val = READ_ONCE(sk->sk_priority);
1815 		break;
1816 
1817 	case SO_LINGER:
1818 		lv		= sizeof(v.ling);
1819 		v.ling.l_onoff	= sock_flag(sk, SOCK_LINGER);
1820 		v.ling.l_linger	= READ_ONCE(sk->sk_lingertime) / HZ;
1821 		break;
1822 
1823 	case SO_BSDCOMPAT:
1824 		break;
1825 
1826 	case SO_TIMESTAMP_OLD:
1827 		v.val = sock_flag(sk, SOCK_RCVTSTAMP) &&
1828 				!sock_flag(sk, SOCK_TSTAMP_NEW) &&
1829 				!sock_flag(sk, SOCK_RCVTSTAMPNS);
1830 		break;
1831 
1832 	case SO_TIMESTAMPNS_OLD:
1833 		v.val = sock_flag(sk, SOCK_RCVTSTAMPNS) && !sock_flag(sk, SOCK_TSTAMP_NEW);
1834 		break;
1835 
1836 	case SO_TIMESTAMP_NEW:
1837 		v.val = sock_flag(sk, SOCK_RCVTSTAMP) && sock_flag(sk, SOCK_TSTAMP_NEW);
1838 		break;
1839 
1840 	case SO_TIMESTAMPNS_NEW:
1841 		v.val = sock_flag(sk, SOCK_RCVTSTAMPNS) && sock_flag(sk, SOCK_TSTAMP_NEW);
1842 		break;
1843 
1844 	case SO_TIMESTAMPING_OLD:
1845 	case SO_TIMESTAMPING_NEW:
1846 		lv = sizeof(v.timestamping);
1847 		/* For the later-added case SO_TIMESTAMPING_NEW: Be strict about only
1848 		 * returning the flags when they were set through the same option.
1849 		 * Don't change the beviour for the old case SO_TIMESTAMPING_OLD.
1850 		 */
1851 		if (optname == SO_TIMESTAMPING_OLD || sock_flag(sk, SOCK_TSTAMP_NEW)) {
1852 			v.timestamping.flags = READ_ONCE(sk->sk_tsflags);
1853 			v.timestamping.bind_phc = READ_ONCE(sk->sk_bind_phc);
1854 		}
1855 		break;
1856 
1857 	case SO_RCVTIMEO_OLD:
1858 	case SO_RCVTIMEO_NEW:
1859 		lv = sock_get_timeout(READ_ONCE(sk->sk_rcvtimeo), &v,
1860 				      SO_RCVTIMEO_OLD == optname);
1861 		break;
1862 
1863 	case SO_SNDTIMEO_OLD:
1864 	case SO_SNDTIMEO_NEW:
1865 		lv = sock_get_timeout(READ_ONCE(sk->sk_sndtimeo), &v,
1866 				      SO_SNDTIMEO_OLD == optname);
1867 		break;
1868 
1869 	case SO_RCVLOWAT:
1870 		v.val = READ_ONCE(sk->sk_rcvlowat);
1871 		break;
1872 
1873 	case SO_SNDLOWAT:
1874 		v.val = 1;
1875 		break;
1876 
1877 	case SO_PASSCRED:
1878 		if (!sk_may_scm_recv(sk))
1879 			return -EOPNOTSUPP;
1880 
1881 		v.val = sk->sk_scm_credentials;
1882 		break;
1883 
1884 	case SO_PASSPIDFD:
1885 		if (!sk_is_unix(sk))
1886 			return -EOPNOTSUPP;
1887 
1888 		v.val = sk->sk_scm_pidfd;
1889 		break;
1890 
1891 	case SO_PASSRIGHTS:
1892 		if (!sk_is_unix(sk))
1893 			return -EOPNOTSUPP;
1894 
1895 		v.val = sk->sk_scm_rights;
1896 		break;
1897 
1898 	case SO_PEERCRED:
1899 	{
1900 		struct ucred peercred;
1901 		if (len > sizeof(peercred))
1902 			len = sizeof(peercred);
1903 
1904 		spin_lock(&sk->sk_peer_lock);
1905 		cred_to_ucred(sk->sk_peer_pid, sk->sk_peer_cred, &peercred);
1906 		spin_unlock(&sk->sk_peer_lock);
1907 
1908 		if (copy_to_sockptr(optval, &peercred, len))
1909 			return -EFAULT;
1910 		goto lenout;
1911 	}
1912 
1913 	case SO_PEERPIDFD:
1914 	{
1915 		struct pid *peer_pid;
1916 		struct file *pidfd_file = NULL;
1917 		unsigned int flags = 0;
1918 		int pidfd;
1919 
1920 		if (len > sizeof(pidfd))
1921 			len = sizeof(pidfd);
1922 
1923 		spin_lock(&sk->sk_peer_lock);
1924 		peer_pid = get_pid(sk->sk_peer_pid);
1925 		spin_unlock(&sk->sk_peer_lock);
1926 
1927 		if (!peer_pid)
1928 			return -ENODATA;
1929 
1930 		/* The use of PIDFD_STALE requires stashing of struct pid
1931 		 * on pidfs with pidfs_register_pid() and only AF_UNIX
1932 		 * were prepared for this.
1933 		 */
1934 		if (sk->sk_family == AF_UNIX)
1935 			flags = PIDFD_STALE;
1936 
1937 		pidfd = pidfd_prepare(peer_pid, flags, &pidfd_file);
1938 		put_pid(peer_pid);
1939 		if (pidfd < 0)
1940 			return pidfd;
1941 
1942 		if (copy_to_sockptr(optval, &pidfd, len) ||
1943 		    copy_to_sockptr(optlen, &len, sizeof(int))) {
1944 			put_unused_fd(pidfd);
1945 			fput(pidfd_file);
1946 
1947 			return -EFAULT;
1948 		}
1949 
1950 		fd_install(pidfd, pidfd_file);
1951 		return 0;
1952 	}
1953 
1954 	case SO_PEERGROUPS:
1955 	{
1956 		const struct cred *cred;
1957 		int ret, n;
1958 
1959 		cred = sk_get_peer_cred(sk);
1960 		if (!cred)
1961 			return -ENODATA;
1962 
1963 		n = cred->group_info->ngroups;
1964 		if (len < n * sizeof(gid_t)) {
1965 			len = n * sizeof(gid_t);
1966 			put_cred(cred);
1967 			return copy_to_sockptr(optlen, &len, sizeof(int)) ? -EFAULT : -ERANGE;
1968 		}
1969 		len = n * sizeof(gid_t);
1970 
1971 		ret = groups_to_user(optval, cred->group_info);
1972 		put_cred(cred);
1973 		if (ret)
1974 			return ret;
1975 		goto lenout;
1976 	}
1977 
1978 	case SO_PEERNAME:
1979 	{
1980 		struct sockaddr_storage address;
1981 
1982 		lv = READ_ONCE(sock->ops)->getname(sock, (struct sockaddr *)&address, 2);
1983 		if (lv < 0)
1984 			return -ENOTCONN;
1985 		if (lv < len)
1986 			return -EINVAL;
1987 		if (copy_to_sockptr(optval, &address, len))
1988 			return -EFAULT;
1989 		goto lenout;
1990 	}
1991 
1992 	/* Dubious BSD thing... Probably nobody even uses it, but
1993 	 * the UNIX standard wants it for whatever reason... -DaveM
1994 	 */
1995 	case SO_ACCEPTCONN:
1996 		v.val = sk->sk_state == TCP_LISTEN;
1997 		break;
1998 
1999 	case SO_PASSSEC:
2000 		if (!IS_ENABLED(CONFIG_SECURITY_NETWORK) || !sk_may_scm_recv(sk))
2001 			return -EOPNOTSUPP;
2002 
2003 		v.val = sk->sk_scm_security;
2004 		break;
2005 
2006 	case SO_PEERSEC:
2007 		return security_socket_getpeersec_stream(sock,
2008 							 optval, optlen, len);
2009 
2010 	case SO_MARK:
2011 		v.val = READ_ONCE(sk->sk_mark);
2012 		break;
2013 
2014 	case SO_RCVMARK:
2015 		v.val = sock_flag(sk, SOCK_RCVMARK);
2016 		break;
2017 
2018 	case SO_RCVPRIORITY:
2019 		v.val = sock_flag(sk, SOCK_RCVPRIORITY);
2020 		break;
2021 
2022 	case SO_RXQ_OVFL:
2023 		v.val = sock_flag(sk, SOCK_RXQ_OVFL);
2024 		break;
2025 
2026 	case SO_WIFI_STATUS:
2027 		v.val = sock_flag(sk, SOCK_WIFI_STATUS);
2028 		break;
2029 
2030 	case SO_PEEK_OFF:
2031 		if (!READ_ONCE(sock->ops)->set_peek_off)
2032 			return -EOPNOTSUPP;
2033 
2034 		v.val = READ_ONCE(sk->sk_peek_off);
2035 		break;
2036 	case SO_NOFCS:
2037 		v.val = sock_flag(sk, SOCK_NOFCS);
2038 		break;
2039 
2040 	case SO_BINDTODEVICE:
2041 		return sock_getbindtodevice(sk, optval, optlen, len);
2042 
2043 	case SO_GET_FILTER:
2044 		len = sk_get_filter(sk, optval, len);
2045 		if (len < 0)
2046 			return len;
2047 
2048 		goto lenout;
2049 
2050 	case SO_LOCK_FILTER:
2051 		v.val = sock_flag(sk, SOCK_FILTER_LOCKED);
2052 		break;
2053 
2054 	case SO_BPF_EXTENSIONS:
2055 		v.val = bpf_tell_extensions();
2056 		break;
2057 
2058 	case SO_SELECT_ERR_QUEUE:
2059 		v.val = sock_flag(sk, SOCK_SELECT_ERR_QUEUE);
2060 		break;
2061 
2062 #ifdef CONFIG_NET_RX_BUSY_POLL
2063 	case SO_BUSY_POLL:
2064 		v.val = READ_ONCE(sk->sk_ll_usec);
2065 		break;
2066 	case SO_PREFER_BUSY_POLL:
2067 		v.val = READ_ONCE(sk->sk_prefer_busy_poll);
2068 		break;
2069 #endif
2070 
2071 	case SO_MAX_PACING_RATE:
2072 		/* The READ_ONCE() pair with the WRITE_ONCE() in sk_setsockopt() */
2073 		if (sizeof(v.ulval) != sizeof(v.val) && len >= sizeof(v.ulval)) {
2074 			lv = sizeof(v.ulval);
2075 			v.ulval = READ_ONCE(sk->sk_max_pacing_rate);
2076 		} else {
2077 			/* 32bit version */
2078 			v.val = min_t(unsigned long, ~0U,
2079 				      READ_ONCE(sk->sk_max_pacing_rate));
2080 		}
2081 		break;
2082 
2083 	case SO_INCOMING_CPU:
2084 		v.val = READ_ONCE(sk->sk_incoming_cpu);
2085 		break;
2086 
2087 	case SO_MEMINFO:
2088 	{
2089 		u32 meminfo[SK_MEMINFO_VARS];
2090 
2091 		sk_get_meminfo(sk, meminfo);
2092 
2093 		len = min_t(unsigned int, len, sizeof(meminfo));
2094 		if (copy_to_sockptr(optval, &meminfo, len))
2095 			return -EFAULT;
2096 
2097 		goto lenout;
2098 	}
2099 
2100 #ifdef CONFIG_NET_RX_BUSY_POLL
2101 	case SO_INCOMING_NAPI_ID:
2102 		v.val = READ_ONCE(sk->sk_napi_id);
2103 
2104 		/* aggregate non-NAPI IDs down to 0 */
2105 		if (!napi_id_valid(v.val))
2106 			v.val = 0;
2107 
2108 		break;
2109 #endif
2110 
2111 	case SO_COOKIE:
2112 		lv = sizeof(u64);
2113 		if (len < lv)
2114 			return -EINVAL;
2115 		v.val64 = sock_gen_cookie(sk);
2116 		break;
2117 
2118 	case SO_ZEROCOPY:
2119 		v.val = sock_flag(sk, SOCK_ZEROCOPY);
2120 		break;
2121 
2122 	case SO_TXTIME:
2123 		lv = sizeof(v.txtime);
2124 		v.txtime.clockid = sk->sk_clockid;
2125 		v.txtime.flags |= sk->sk_txtime_deadline_mode ?
2126 				  SOF_TXTIME_DEADLINE_MODE : 0;
2127 		v.txtime.flags |= sk->sk_txtime_report_errors ?
2128 				  SOF_TXTIME_REPORT_ERRORS : 0;
2129 		break;
2130 
2131 	case SO_BINDTOIFINDEX:
2132 		v.val = READ_ONCE(sk->sk_bound_dev_if);
2133 		break;
2134 
2135 	case SO_NETNS_COOKIE:
2136 		lv = sizeof(u64);
2137 		if (len != lv)
2138 			return -EINVAL;
2139 		v.val64 = sock_net(sk)->net_cookie;
2140 		break;
2141 
2142 	case SO_BUF_LOCK:
2143 		v.val = sk->sk_userlocks & SOCK_BUF_LOCK_MASK;
2144 		break;
2145 
2146 	case SO_RESERVE_MEM:
2147 		v.val = READ_ONCE(sk->sk_reserved_mem);
2148 		break;
2149 
2150 	case SO_TXREHASH:
2151 		if (!sk_is_tcp(sk))
2152 			return -EOPNOTSUPP;
2153 
2154 		/* Paired with WRITE_ONCE() in sk_setsockopt() */
2155 		v.val = READ_ONCE(sk->sk_txrehash);
2156 		break;
2157 
2158 	default:
2159 		/* We implement the SO_SNDLOWAT etc to not be settable
2160 		 * (1003.1g 7).
2161 		 */
2162 		return -ENOPROTOOPT;
2163 	}
2164 
2165 	if (len > lv)
2166 		len = lv;
2167 	if (copy_to_sockptr(optval, &v, len))
2168 		return -EFAULT;
2169 lenout:
2170 	if (copy_to_sockptr(optlen, &len, sizeof(int)))
2171 		return -EFAULT;
2172 	return 0;
2173 }
2174 
2175 /*
2176  * Initialize an sk_lock.
2177  *
2178  * (We also register the sk_lock with the lock validator.)
2179  */
sock_lock_init(struct sock * sk)2180 static inline void sock_lock_init(struct sock *sk)
2181 {
2182 	sk_owner_clear(sk);
2183 
2184 	if (sk->sk_kern_sock)
2185 		sock_lock_init_class_and_name(
2186 			sk,
2187 			af_family_kern_slock_key_strings[sk->sk_family],
2188 			af_family_kern_slock_keys + sk->sk_family,
2189 			af_family_kern_key_strings[sk->sk_family],
2190 			af_family_kern_keys + sk->sk_family);
2191 	else
2192 		sock_lock_init_class_and_name(
2193 			sk,
2194 			af_family_slock_key_strings[sk->sk_family],
2195 			af_family_slock_keys + sk->sk_family,
2196 			af_family_key_strings[sk->sk_family],
2197 			af_family_keys + sk->sk_family);
2198 }
2199 
2200 /*
2201  * Copy all fields from osk to nsk but nsk->sk_refcnt must not change yet,
2202  * even temporarily, because of RCU lookups. sk_node should also be left as is.
2203  * We must not copy fields between sk_dontcopy_begin and sk_dontcopy_end
2204  */
sock_copy(struct sock * nsk,const struct sock * osk)2205 static void sock_copy(struct sock *nsk, const struct sock *osk)
2206 {
2207 	const struct proto *prot = READ_ONCE(osk->sk_prot);
2208 #ifdef CONFIG_SECURITY_NETWORK
2209 	void *sptr = nsk->sk_security;
2210 #endif
2211 
2212 	/* If we move sk_tx_queue_mapping out of the private section,
2213 	 * we must check if sk_tx_queue_clear() is called after
2214 	 * sock_copy() in sk_clone_lock().
2215 	 */
2216 	BUILD_BUG_ON(offsetof(struct sock, sk_tx_queue_mapping) <
2217 		     offsetof(struct sock, sk_dontcopy_begin) ||
2218 		     offsetof(struct sock, sk_tx_queue_mapping) >=
2219 		     offsetof(struct sock, sk_dontcopy_end));
2220 
2221 	memcpy(nsk, osk, offsetof(struct sock, sk_dontcopy_begin));
2222 
2223 	unsafe_memcpy(&nsk->sk_dontcopy_end, &osk->sk_dontcopy_end,
2224 		      prot->obj_size - offsetof(struct sock, sk_dontcopy_end),
2225 		      /* alloc is larger than struct, see sk_prot_alloc() */);
2226 
2227 #ifdef CONFIG_SECURITY_NETWORK
2228 	nsk->sk_security = sptr;
2229 	security_sk_clone(osk, nsk);
2230 #endif
2231 }
2232 
sk_prot_alloc(struct proto * prot,gfp_t priority,int family)2233 static struct sock *sk_prot_alloc(struct proto *prot, gfp_t priority,
2234 		int family)
2235 {
2236 	struct sock *sk;
2237 	struct kmem_cache *slab;
2238 
2239 	slab = prot->slab;
2240 	if (slab != NULL) {
2241 		sk = kmem_cache_alloc(slab, priority & ~__GFP_ZERO);
2242 		if (!sk)
2243 			return sk;
2244 		if (want_init_on_alloc(priority))
2245 			sk_prot_clear_nulls(sk, prot->obj_size);
2246 	} else
2247 		sk = kmalloc(prot->obj_size, priority);
2248 
2249 	if (sk != NULL) {
2250 		if (security_sk_alloc(sk, family, priority))
2251 			goto out_free;
2252 
2253 		if (!try_module_get(prot->owner))
2254 			goto out_free_sec;
2255 	}
2256 
2257 	return sk;
2258 
2259 out_free_sec:
2260 	security_sk_free(sk);
2261 out_free:
2262 	if (slab != NULL)
2263 		kmem_cache_free(slab, sk);
2264 	else
2265 		kfree(sk);
2266 	return NULL;
2267 }
2268 
sk_prot_free(struct proto * prot,struct sock * sk)2269 static void sk_prot_free(struct proto *prot, struct sock *sk)
2270 {
2271 	struct kmem_cache *slab;
2272 	struct module *owner;
2273 
2274 	owner = prot->owner;
2275 	slab = prot->slab;
2276 
2277 	cgroup_sk_free(&sk->sk_cgrp_data);
2278 	mem_cgroup_sk_free(sk);
2279 	security_sk_free(sk);
2280 
2281 	sk_owner_put(sk);
2282 
2283 	if (slab != NULL)
2284 		kmem_cache_free(slab, sk);
2285 	else
2286 		kfree(sk);
2287 	module_put(owner);
2288 }
2289 
2290 /**
2291  *	sk_alloc - All socket objects are allocated here
2292  *	@net: the applicable net namespace
2293  *	@family: protocol family
2294  *	@priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
2295  *	@prot: struct proto associated with this new sock instance
2296  *	@kern: is this to be a kernel socket?
2297  */
sk_alloc(struct net * net,int family,gfp_t priority,struct proto * prot,int kern)2298 struct sock *sk_alloc(struct net *net, int family, gfp_t priority,
2299 		      struct proto *prot, int kern)
2300 {
2301 	struct sock *sk;
2302 
2303 	sk = sk_prot_alloc(prot, priority | __GFP_ZERO, family);
2304 	if (sk) {
2305 		sk->sk_family = family;
2306 		/*
2307 		 * See comment in struct sock definition to understand
2308 		 * why we need sk_prot_creator -acme
2309 		 */
2310 		sk->sk_prot = sk->sk_prot_creator = prot;
2311 
2312 		if (READ_ONCE(net->core.sysctl_bypass_prot_mem))
2313 			sk->sk_bypass_prot_mem = 1;
2314 
2315 		sk->sk_kern_sock = kern;
2316 		sock_lock_init(sk);
2317 
2318 		sk->sk_net_refcnt = kern ? 0 : 1;
2319 		if (likely(sk->sk_net_refcnt)) {
2320 			get_net_track(net, &sk->ns_tracker, priority);
2321 			sock_inuse_add(net, 1);
2322 		} else {
2323 			net_passive_inc(net);
2324 			__netns_tracker_alloc(net, &sk->ns_tracker,
2325 					      false, priority);
2326 		}
2327 
2328 		sock_net_set(sk, net);
2329 		refcount_set(&sk->sk_wmem_alloc, SK_WMEM_ALLOC_BIAS);
2330 
2331 		mem_cgroup_sk_alloc(sk);
2332 		cgroup_sk_alloc(&sk->sk_cgrp_data);
2333 		sock_update_classid(&sk->sk_cgrp_data);
2334 		sock_update_netprioidx(&sk->sk_cgrp_data);
2335 		sk_tx_queue_clear(sk);
2336 	}
2337 
2338 	return sk;
2339 }
2340 EXPORT_SYMBOL(sk_alloc);
2341 
2342 /* Sockets having SOCK_RCU_FREE will call this function after one RCU
2343  * grace period. This is the case for UDP sockets and TCP listeners.
2344  */
__sk_destruct(struct rcu_head * head)2345 static void __sk_destruct(struct rcu_head *head)
2346 {
2347 	struct sock *sk = container_of(head, struct sock, sk_rcu);
2348 	struct net *net = sock_net(sk);
2349 	struct sk_filter *filter;
2350 
2351 	if (sk->sk_destruct)
2352 		sk->sk_destruct(sk);
2353 
2354 	filter = rcu_dereference_check(sk->sk_filter,
2355 				       refcount_read(&sk->sk_wmem_alloc) == 0);
2356 	if (filter) {
2357 		sk_filter_uncharge(sk, filter);
2358 		RCU_INIT_POINTER(sk->sk_filter, NULL);
2359 	}
2360 
2361 	sock_disable_timestamp(sk, SK_FLAGS_TIMESTAMP);
2362 
2363 #ifdef CONFIG_BPF_SYSCALL
2364 	bpf_sk_storage_free(sk);
2365 #endif
2366 
2367 	if (atomic_read(&sk->sk_omem_alloc))
2368 		pr_debug("%s: optmem leakage (%d bytes) detected\n",
2369 			 __func__, atomic_read(&sk->sk_omem_alloc));
2370 
2371 	if (sk->sk_frag.page) {
2372 		put_page(sk->sk_frag.page);
2373 		sk->sk_frag.page = NULL;
2374 	}
2375 
2376 	/* We do not need to acquire sk->sk_peer_lock, we are the last user. */
2377 	put_cred(sk->sk_peer_cred);
2378 	put_pid(sk->sk_peer_pid);
2379 
2380 	if (likely(sk->sk_net_refcnt)) {
2381 		put_net_track(net, &sk->ns_tracker);
2382 	} else {
2383 		__netns_tracker_free(net, &sk->ns_tracker, false);
2384 		net_passive_dec(net);
2385 	}
2386 	sk_prot_free(sk->sk_prot_creator, sk);
2387 }
2388 
sk_net_refcnt_upgrade(struct sock * sk)2389 void sk_net_refcnt_upgrade(struct sock *sk)
2390 {
2391 	struct net *net = sock_net(sk);
2392 
2393 	WARN_ON_ONCE(sk->sk_net_refcnt);
2394 	__netns_tracker_free(net, &sk->ns_tracker, false);
2395 	net_passive_dec(net);
2396 	sk->sk_net_refcnt = 1;
2397 	get_net_track(net, &sk->ns_tracker, GFP_KERNEL);
2398 	sock_inuse_add(net, 1);
2399 }
2400 EXPORT_SYMBOL_GPL(sk_net_refcnt_upgrade);
2401 
sk_destruct(struct sock * sk)2402 void sk_destruct(struct sock *sk)
2403 {
2404 	bool use_call_rcu = sock_flag(sk, SOCK_RCU_FREE);
2405 
2406 	if (rcu_access_pointer(sk->sk_reuseport_cb)) {
2407 		reuseport_detach_sock(sk);
2408 		use_call_rcu = true;
2409 	}
2410 
2411 	if (use_call_rcu)
2412 		call_rcu(&sk->sk_rcu, __sk_destruct);
2413 	else
2414 		__sk_destruct(&sk->sk_rcu);
2415 }
2416 
__sk_free(struct sock * sk)2417 static void __sk_free(struct sock *sk)
2418 {
2419 	if (likely(sk->sk_net_refcnt))
2420 		sock_inuse_add(sock_net(sk), -1);
2421 
2422 	if (unlikely(sk->sk_net_refcnt && sock_diag_has_destroy_listeners(sk)))
2423 		sock_diag_broadcast_destroy(sk);
2424 	else
2425 		sk_destruct(sk);
2426 }
2427 
sk_free(struct sock * sk)2428 void sk_free(struct sock *sk)
2429 {
2430 	/*
2431 	 * We subtract one from sk_wmem_alloc and can know if
2432 	 * some packets are still in some tx queue.
2433 	 * If not null, sock_wfree() will call __sk_free(sk) later
2434 	 */
2435 	if (refcount_dec_and_test(&sk->sk_wmem_alloc))
2436 		__sk_free(sk);
2437 }
2438 EXPORT_SYMBOL(sk_free);
2439 
sk_init_common(struct sock * sk)2440 static void sk_init_common(struct sock *sk)
2441 {
2442 	skb_queue_head_init(&sk->sk_receive_queue);
2443 	skb_queue_head_init(&sk->sk_write_queue);
2444 	skb_queue_head_init(&sk->sk_error_queue);
2445 
2446 	rwlock_init(&sk->sk_callback_lock);
2447 	lockdep_set_class_and_name(&sk->sk_receive_queue.lock,
2448 			af_rlock_keys + sk->sk_family,
2449 			af_family_rlock_key_strings[sk->sk_family]);
2450 	lockdep_set_class_and_name(&sk->sk_write_queue.lock,
2451 			af_wlock_keys + sk->sk_family,
2452 			af_family_wlock_key_strings[sk->sk_family]);
2453 	lockdep_set_class_and_name(&sk->sk_error_queue.lock,
2454 			af_elock_keys + sk->sk_family,
2455 			af_family_elock_key_strings[sk->sk_family]);
2456 	if (sk->sk_kern_sock)
2457 		lockdep_set_class_and_name(&sk->sk_callback_lock,
2458 			af_kern_callback_keys + sk->sk_family,
2459 			af_family_kern_clock_key_strings[sk->sk_family]);
2460 	else
2461 		lockdep_set_class_and_name(&sk->sk_callback_lock,
2462 			af_callback_keys + sk->sk_family,
2463 			af_family_clock_key_strings[sk->sk_family]);
2464 }
2465 
2466 /**
2467  * sk_clone - clone a socket
2468  * @sk: the socket to clone
2469  * @priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
2470  * @lock: if true, lock the cloned sk
2471  *
2472  * If @lock is true, the clone is locked by bh_lock_sock(), and
2473  * caller must unlock socket even in error path by bh_unlock_sock().
2474  */
sk_clone(const struct sock * sk,const gfp_t priority,bool lock)2475 struct sock *sk_clone(const struct sock *sk, const gfp_t priority,
2476 		      bool lock)
2477 {
2478 	struct proto *prot = READ_ONCE(sk->sk_prot);
2479 	struct sk_filter *filter;
2480 	bool is_charged = true;
2481 	struct sock *newsk;
2482 
2483 	newsk = sk_prot_alloc(prot, priority, sk->sk_family);
2484 	if (!newsk)
2485 		goto out;
2486 
2487 	sock_copy(newsk, sk);
2488 
2489 	newsk->sk_prot_creator = prot;
2490 
2491 	/* SANITY */
2492 	if (likely(newsk->sk_net_refcnt)) {
2493 		get_net_track(sock_net(newsk), &newsk->ns_tracker, priority);
2494 		sock_inuse_add(sock_net(newsk), 1);
2495 	} else {
2496 		/* Kernel sockets are not elevating the struct net refcount.
2497 		 * Instead, use a tracker to more easily detect if a layer
2498 		 * is not properly dismantling its kernel sockets at netns
2499 		 * destroy time.
2500 		 */
2501 		net_passive_inc(sock_net(newsk));
2502 		__netns_tracker_alloc(sock_net(newsk), &newsk->ns_tracker,
2503 				      false, priority);
2504 	}
2505 
2506 	sk_node_init(&newsk->sk_node);
2507 	sock_lock_init(newsk);
2508 
2509 	if (lock)
2510 		bh_lock_sock(newsk);
2511 
2512 	newsk->sk_backlog.head	= newsk->sk_backlog.tail = NULL;
2513 	newsk->sk_backlog.len = 0;
2514 
2515 	atomic_set(&newsk->sk_rmem_alloc, 0);
2516 
2517 	refcount_set(&newsk->sk_wmem_alloc, SK_WMEM_ALLOC_BIAS);
2518 
2519 	atomic_set(&newsk->sk_omem_alloc, 0);
2520 	sk_init_common(newsk);
2521 
2522 	newsk->sk_dst_cache	= NULL;
2523 	newsk->sk_dst_pending_confirm = 0;
2524 	newsk->sk_wmem_queued	= 0;
2525 	newsk->sk_forward_alloc = 0;
2526 	newsk->sk_reserved_mem  = 0;
2527 	DEBUG_NET_WARN_ON_ONCE(newsk->sk_drop_counters);
2528 	sk_drops_reset(newsk);
2529 	newsk->sk_send_head	= NULL;
2530 	newsk->sk_userlocks	= sk->sk_userlocks & ~SOCK_BINDPORT_LOCK;
2531 	atomic_set(&newsk->sk_zckey, 0);
2532 
2533 	sock_reset_flag(newsk, SOCK_DONE);
2534 
2535 #ifdef CONFIG_MEMCG
2536 	/* sk->sk_memcg will be populated at accept() time */
2537 	newsk->sk_memcg = NULL;
2538 #endif
2539 
2540 	cgroup_sk_clone(&newsk->sk_cgrp_data);
2541 
2542 	rcu_read_lock();
2543 	filter = rcu_dereference(sk->sk_filter);
2544 	if (filter != NULL)
2545 		/* though it's an empty new sock, the charging may fail
2546 		 * if sysctl_optmem_max was changed between creation of
2547 		 * original socket and cloning
2548 		 */
2549 		is_charged = sk_filter_charge(newsk, filter);
2550 	RCU_INIT_POINTER(newsk->sk_filter, filter);
2551 	rcu_read_unlock();
2552 
2553 	if (unlikely(!is_charged || xfrm_sk_clone_policy(newsk, sk))) {
2554 		/* We need to make sure that we don't uncharge the new
2555 		 * socket if we couldn't charge it in the first place
2556 		 * as otherwise we uncharge the parent's filter.
2557 		 */
2558 		if (!is_charged)
2559 			RCU_INIT_POINTER(newsk->sk_filter, NULL);
2560 
2561 		goto free;
2562 	}
2563 
2564 	RCU_INIT_POINTER(newsk->sk_reuseport_cb, NULL);
2565 
2566 	if (bpf_sk_storage_clone(sk, newsk))
2567 		goto free;
2568 
2569 	/* Clear sk_user_data if parent had the pointer tagged
2570 	 * as not suitable for copying when cloning.
2571 	 */
2572 	if (sk_user_data_is_nocopy(newsk))
2573 		newsk->sk_user_data = NULL;
2574 
2575 	newsk->sk_err	   = 0;
2576 	newsk->sk_err_soft = 0;
2577 	newsk->sk_priority = 0;
2578 	newsk->sk_incoming_cpu = raw_smp_processor_id();
2579 
2580 	/* Before updating sk_refcnt, we must commit prior changes to memory
2581 	 * (Documentation/RCU/rculist_nulls.rst for details)
2582 	 */
2583 	smp_wmb();
2584 	refcount_set(&newsk->sk_refcnt, 2);
2585 
2586 	sk_set_socket(newsk, NULL);
2587 	sk_tx_queue_clear(newsk);
2588 	sk_rx_queue_clear(newsk);
2589 	RCU_INIT_POINTER(newsk->sk_wq, NULL);
2590 
2591 	if (newsk->sk_prot->sockets_allocated)
2592 		sk_sockets_allocated_inc(newsk);
2593 
2594 	if (sock_needs_netstamp(sk) && newsk->sk_flags & SK_FLAGS_TIMESTAMP)
2595 		net_enable_timestamp();
2596 out:
2597 	return newsk;
2598 free:
2599 	/* It is still raw copy of parent, so invalidate
2600 	 * destructor and make plain sk_free()
2601 	 */
2602 	newsk->sk_destruct = NULL;
2603 	if (lock)
2604 		bh_unlock_sock(newsk);
2605 	sk_free(newsk);
2606 	newsk = NULL;
2607 	goto out;
2608 }
2609 EXPORT_SYMBOL_GPL(sk_clone);
2610 
sk_dst_gso_max_size(struct sock * sk,const struct net_device * dev)2611 static u32 sk_dst_gso_max_size(struct sock *sk, const struct net_device *dev)
2612 {
2613 	bool is_ipv6 = false;
2614 	u32 max_size;
2615 
2616 #if IS_ENABLED(CONFIG_IPV6)
2617 	is_ipv6 = (sk->sk_family == AF_INET6 &&
2618 		   !ipv6_addr_v4mapped(&sk->sk_v6_rcv_saddr));
2619 #endif
2620 	/* pairs with the WRITE_ONCE() in netif_set_gso(_ipv4)_max_size() */
2621 	max_size = is_ipv6 ? READ_ONCE(dev->gso_max_size) :
2622 			READ_ONCE(dev->gso_ipv4_max_size);
2623 	if (max_size > GSO_LEGACY_MAX_SIZE && !sk_is_tcp(sk))
2624 		max_size = GSO_LEGACY_MAX_SIZE;
2625 
2626 	return max_size - (MAX_TCP_HEADER + 1);
2627 }
2628 
sk_setup_caps(struct sock * sk,struct dst_entry * dst)2629 void sk_setup_caps(struct sock *sk, struct dst_entry *dst)
2630 {
2631 	const struct net_device *dev;
2632 	u32 max_segs = 1;
2633 
2634 	rcu_read_lock();
2635 	dev = dst_dev_rcu(dst);
2636 	sk->sk_route_caps = dev->features;
2637 	if (sk_is_tcp(sk)) {
2638 		struct inet_connection_sock *icsk = inet_csk(sk);
2639 
2640 		sk->sk_route_caps |= NETIF_F_GSO;
2641 		icsk->icsk_ack.dst_quick_ack = dst_metric(dst, RTAX_QUICKACK);
2642 	}
2643 	if (sk->sk_route_caps & NETIF_F_GSO)
2644 		sk->sk_route_caps |= NETIF_F_GSO_SOFTWARE;
2645 	if (unlikely(sk->sk_gso_disabled))
2646 		sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
2647 	if (sk_can_gso(sk)) {
2648 		if (dst->header_len && !xfrm_dst_offload_ok(dst)) {
2649 			sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
2650 		} else {
2651 			sk->sk_route_caps |= NETIF_F_SG | NETIF_F_HW_CSUM;
2652 			sk->sk_gso_max_size = sk_dst_gso_max_size(sk, dev);
2653 			/* pairs with the WRITE_ONCE() in netif_set_gso_max_segs() */
2654 			max_segs = max_t(u32, READ_ONCE(dev->gso_max_segs), 1);
2655 		}
2656 	}
2657 	sk->sk_gso_max_segs = max_segs;
2658 	sk_dst_set(sk, dst);
2659 	rcu_read_unlock();
2660 }
2661 EXPORT_SYMBOL_GPL(sk_setup_caps);
2662 
2663 /*
2664  *	Simple resource managers for sockets.
2665  */
2666 
2667 
2668 /*
2669  * Write buffer destructor automatically called from kfree_skb.
2670  */
sock_wfree(struct sk_buff * skb)2671 void sock_wfree(struct sk_buff *skb)
2672 {
2673 	unsigned int len = skb->truesize;
2674 	struct sock *sk = skb->sk;
2675 	bool free;
2676 	int old;
2677 
2678 	if (!sock_flag(sk, SOCK_USE_WRITE_QUEUE)) {
2679 		void (*sk_write_space)(struct sock *sk);
2680 
2681 		sk_write_space = READ_ONCE(sk->sk_write_space);
2682 
2683 		if (sock_flag(sk, SOCK_RCU_FREE) &&
2684 		    sk_write_space == sock_def_write_space) {
2685 			rcu_read_lock();
2686 			free = __refcount_sub_and_test(len, &sk->sk_wmem_alloc,
2687 						       &old);
2688 			sock_def_write_space_wfree(sk, old - len);
2689 			rcu_read_unlock();
2690 			if (unlikely(free))
2691 				__sk_free(sk);
2692 			return;
2693 		}
2694 
2695 		/*
2696 		 * Keep a reference on sk_wmem_alloc, this will be released
2697 		 * after sk_write_space() call
2698 		 */
2699 		WARN_ON(refcount_sub_and_test(len - 1, &sk->sk_wmem_alloc));
2700 		sk_write_space(sk);
2701 		len = 1;
2702 	}
2703 	/*
2704 	 * if sk_wmem_alloc reaches 0, we must finish what sk_free()
2705 	 * could not do because of in-flight packets
2706 	 */
2707 	if (refcount_sub_and_test(len, &sk->sk_wmem_alloc))
2708 		__sk_free(sk);
2709 }
2710 EXPORT_SYMBOL(sock_wfree);
2711 
2712 /* This variant of sock_wfree() is used by TCP,
2713  * since it sets SOCK_USE_WRITE_QUEUE.
2714  */
__sock_wfree(struct sk_buff * skb)2715 void __sock_wfree(struct sk_buff *skb)
2716 {
2717 	struct sock *sk = skb->sk;
2718 
2719 	if (refcount_sub_and_test(skb->truesize, &sk->sk_wmem_alloc))
2720 		__sk_free(sk);
2721 }
2722 
skb_set_owner_w(struct sk_buff * skb,struct sock * sk)2723 void skb_set_owner_w(struct sk_buff *skb, struct sock *sk)
2724 {
2725 	int old_wmem;
2726 
2727 	skb_orphan(skb);
2728 #ifdef CONFIG_INET
2729 	if (unlikely(!sk_fullsock(sk)))
2730 		return skb_set_owner_edemux(skb, sk);
2731 #endif
2732 	skb->sk = sk;
2733 	skb->destructor = sock_wfree;
2734 	skb_set_hash_from_sk(skb, sk);
2735 	/*
2736 	 * We used to take a refcount on sk, but following operation
2737 	 * is enough to guarantee sk_free() won't free this sock until
2738 	 * all in-flight packets are completed
2739 	 */
2740 	__refcount_add(skb->truesize, &sk->sk_wmem_alloc, &old_wmem);
2741 
2742 	/* (old_wmem == SK_WMEM_ALLOC_BIAS) if no other TX packet for this socket
2743 	 * is in a host queue (qdisc, NIC queue).
2744 	 * Set skb->ooo_okay so that netdev_pick_tx() can choose a TX queue
2745 	 * based on XPS for better performance.
2746 	 * Otherwise clear ooo_okay to not risk Out Of Order delivery.
2747 	 */
2748 	skb->ooo_okay = (old_wmem == SK_WMEM_ALLOC_BIAS);
2749 }
2750 EXPORT_SYMBOL(skb_set_owner_w);
2751 
can_skb_orphan_partial(const struct sk_buff * skb)2752 static bool can_skb_orphan_partial(const struct sk_buff *skb)
2753 {
2754 	/* Drivers depend on in-order delivery for crypto offload,
2755 	 * partial orphan breaks out-of-order-OK logic.
2756 	 */
2757 	if (skb_is_decrypted(skb))
2758 		return false;
2759 
2760 	return (skb->destructor == sock_wfree ||
2761 		(IS_ENABLED(CONFIG_INET) && skb->destructor == tcp_wfree));
2762 }
2763 
2764 /* This helper is used by netem, as it can hold packets in its
2765  * delay queue. We want to allow the owner socket to send more
2766  * packets, as if they were already TX completed by a typical driver.
2767  * But we also want to keep skb->sk set because some packet schedulers
2768  * rely on it (sch_fq for example).
2769  */
skb_orphan_partial(struct sk_buff * skb)2770 void skb_orphan_partial(struct sk_buff *skb)
2771 {
2772 	if (skb_is_tcp_pure_ack(skb))
2773 		return;
2774 
2775 	if (can_skb_orphan_partial(skb) && skb_set_owner_sk_safe(skb, skb->sk))
2776 		return;
2777 
2778 	skb_orphan(skb);
2779 }
2780 EXPORT_SYMBOL(skb_orphan_partial);
2781 
2782 /*
2783  * Read buffer destructor automatically called from kfree_skb.
2784  */
sock_rfree(struct sk_buff * skb)2785 void sock_rfree(struct sk_buff *skb)
2786 {
2787 	struct sock *sk = skb->sk;
2788 	unsigned int len = skb->truesize;
2789 
2790 	atomic_sub(len, &sk->sk_rmem_alloc);
2791 	sk_mem_uncharge(sk, len);
2792 }
2793 EXPORT_SYMBOL(sock_rfree);
2794 
2795 /*
2796  * Buffer destructor for skbs that are not used directly in read or write
2797  * path, e.g. for error handler skbs. Automatically called from kfree_skb.
2798  */
sock_efree(struct sk_buff * skb)2799 void sock_efree(struct sk_buff *skb)
2800 {
2801 	sock_put(skb->sk);
2802 }
2803 EXPORT_SYMBOL(sock_efree);
2804 
2805 /* Buffer destructor for prefetch/receive path where reference count may
2806  * not be held, e.g. for listen sockets.
2807  */
2808 #ifdef CONFIG_INET
sock_pfree(struct sk_buff * skb)2809 void sock_pfree(struct sk_buff *skb)
2810 {
2811 	struct sock *sk = skb->sk;
2812 
2813 	if (!sk_is_refcounted(sk))
2814 		return;
2815 
2816 	if (sk->sk_state == TCP_NEW_SYN_RECV && inet_reqsk(sk)->syncookie) {
2817 		inet_reqsk(sk)->rsk_listener = NULL;
2818 		reqsk_free(inet_reqsk(sk));
2819 		return;
2820 	}
2821 
2822 	sock_gen_put(sk);
2823 }
2824 EXPORT_SYMBOL(sock_pfree);
2825 #endif /* CONFIG_INET */
2826 
2827 /*
2828  * Allocate a skb from the socket's send buffer.
2829  */
sock_wmalloc(struct sock * sk,unsigned long size,int force,gfp_t priority)2830 struct sk_buff *sock_wmalloc(struct sock *sk, unsigned long size, int force,
2831 			     gfp_t priority)
2832 {
2833 	if (force ||
2834 	    refcount_read(&sk->sk_wmem_alloc) < READ_ONCE(sk->sk_sndbuf)) {
2835 		struct sk_buff *skb = alloc_skb(size, priority);
2836 
2837 		if (skb) {
2838 			skb_set_owner_w(skb, sk);
2839 			return skb;
2840 		}
2841 	}
2842 	return NULL;
2843 }
2844 EXPORT_SYMBOL(sock_wmalloc);
2845 
sock_ofree(struct sk_buff * skb)2846 static void sock_ofree(struct sk_buff *skb)
2847 {
2848 	struct sock *sk = skb->sk;
2849 
2850 	atomic_sub(skb->truesize, &sk->sk_omem_alloc);
2851 }
2852 
sock_omalloc(struct sock * sk,unsigned long size,gfp_t priority)2853 struct sk_buff *sock_omalloc(struct sock *sk, unsigned long size,
2854 			     gfp_t priority)
2855 {
2856 	struct sk_buff *skb;
2857 
2858 	/* small safe race: SKB_TRUESIZE may differ from final skb->truesize */
2859 	if (atomic_read(&sk->sk_omem_alloc) + SKB_TRUESIZE(size) >
2860 	    READ_ONCE(sock_net(sk)->core.sysctl_optmem_max))
2861 		return NULL;
2862 
2863 	skb = alloc_skb(size, priority);
2864 	if (!skb)
2865 		return NULL;
2866 
2867 	atomic_add(skb->truesize, &sk->sk_omem_alloc);
2868 	skb->sk = sk;
2869 	skb->destructor = sock_ofree;
2870 	return skb;
2871 }
2872 
2873 /*
2874  * Allocate a memory block from the socket's option memory buffer.
2875  */
sock_kmalloc(struct sock * sk,int size,gfp_t priority)2876 void *sock_kmalloc(struct sock *sk, int size, gfp_t priority)
2877 {
2878 	int optmem_max = READ_ONCE(sock_net(sk)->core.sysctl_optmem_max);
2879 
2880 	if ((unsigned int)size <= optmem_max &&
2881 	    atomic_read(&sk->sk_omem_alloc) + size < optmem_max) {
2882 		void *mem;
2883 		/* First do the add, to avoid the race if kmalloc
2884 		 * might sleep.
2885 		 */
2886 		atomic_add(size, &sk->sk_omem_alloc);
2887 		mem = kmalloc(size, priority);
2888 		if (mem)
2889 			return mem;
2890 		atomic_sub(size, &sk->sk_omem_alloc);
2891 	}
2892 	return NULL;
2893 }
2894 EXPORT_SYMBOL(sock_kmalloc);
2895 
2896 /*
2897  * Duplicate the input "src" memory block using the socket's
2898  * option memory buffer.
2899  */
sock_kmemdup(struct sock * sk,const void * src,int size,gfp_t priority)2900 void *sock_kmemdup(struct sock *sk, const void *src,
2901 		   int size, gfp_t priority)
2902 {
2903 	void *mem;
2904 
2905 	mem = sock_kmalloc(sk, size, priority);
2906 	if (mem)
2907 		memcpy(mem, src, size);
2908 	return mem;
2909 }
2910 EXPORT_SYMBOL(sock_kmemdup);
2911 
2912 /* Free an option memory block. Note, we actually want the inline
2913  * here as this allows gcc to detect the nullify and fold away the
2914  * condition entirely.
2915  */
__sock_kfree_s(struct sock * sk,void * mem,int size,const bool nullify)2916 static inline void __sock_kfree_s(struct sock *sk, void *mem, int size,
2917 				  const bool nullify)
2918 {
2919 	if (WARN_ON_ONCE(!mem))
2920 		return;
2921 	if (nullify)
2922 		kfree_sensitive(mem);
2923 	else
2924 		kfree(mem);
2925 	atomic_sub(size, &sk->sk_omem_alloc);
2926 }
2927 
sock_kfree_s(struct sock * sk,void * mem,int size)2928 void sock_kfree_s(struct sock *sk, void *mem, int size)
2929 {
2930 	__sock_kfree_s(sk, mem, size, false);
2931 }
2932 EXPORT_SYMBOL(sock_kfree_s);
2933 
sock_kzfree_s(struct sock * sk,void * mem,int size)2934 void sock_kzfree_s(struct sock *sk, void *mem, int size)
2935 {
2936 	__sock_kfree_s(sk, mem, size, true);
2937 }
2938 EXPORT_SYMBOL(sock_kzfree_s);
2939 
2940 /* It is almost wait_for_tcp_memory minus release_sock/lock_sock.
2941    I think, these locks should be removed for datagram sockets.
2942  */
sock_wait_for_wmem(struct sock * sk,long timeo)2943 static long sock_wait_for_wmem(struct sock *sk, long timeo)
2944 {
2945 	DEFINE_WAIT(wait);
2946 
2947 	sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
2948 	for (;;) {
2949 		if (!timeo)
2950 			break;
2951 		if (signal_pending(current))
2952 			break;
2953 		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
2954 		prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
2955 		if (refcount_read(&sk->sk_wmem_alloc) < READ_ONCE(sk->sk_sndbuf))
2956 			break;
2957 		if (READ_ONCE(sk->sk_shutdown) & SEND_SHUTDOWN)
2958 			break;
2959 		if (READ_ONCE(sk->sk_err))
2960 			break;
2961 		timeo = schedule_timeout(timeo);
2962 	}
2963 	finish_wait(sk_sleep(sk), &wait);
2964 	return timeo;
2965 }
2966 
2967 
2968 /*
2969  *	Generic send/receive buffer handlers
2970  */
2971 
sock_alloc_send_pskb(struct sock * sk,unsigned long header_len,unsigned long data_len,int noblock,int * errcode,int max_page_order)2972 struct sk_buff *sock_alloc_send_pskb(struct sock *sk, unsigned long header_len,
2973 				     unsigned long data_len, int noblock,
2974 				     int *errcode, int max_page_order)
2975 {
2976 	struct sk_buff *skb;
2977 	long timeo;
2978 	int err;
2979 
2980 	timeo = sock_sndtimeo(sk, noblock);
2981 	for (;;) {
2982 		err = sock_error(sk);
2983 		if (err != 0)
2984 			goto failure;
2985 
2986 		err = -EPIPE;
2987 		if (READ_ONCE(sk->sk_shutdown) & SEND_SHUTDOWN)
2988 			goto failure;
2989 
2990 		if (sk_wmem_alloc_get(sk) < READ_ONCE(sk->sk_sndbuf))
2991 			break;
2992 
2993 		sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
2994 		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
2995 		err = -EAGAIN;
2996 		if (!timeo)
2997 			goto failure;
2998 		if (signal_pending(current))
2999 			goto interrupted;
3000 		timeo = sock_wait_for_wmem(sk, timeo);
3001 	}
3002 	skb = alloc_skb_with_frags(header_len, data_len, max_page_order,
3003 				   errcode, sk->sk_allocation);
3004 	if (skb)
3005 		skb_set_owner_w(skb, sk);
3006 	return skb;
3007 
3008 interrupted:
3009 	err = sock_intr_errno(timeo);
3010 failure:
3011 	*errcode = err;
3012 	return NULL;
3013 }
3014 EXPORT_SYMBOL(sock_alloc_send_pskb);
3015 
__sock_cmsg_send(struct sock * sk,struct cmsghdr * cmsg,struct sockcm_cookie * sockc)3016 int __sock_cmsg_send(struct sock *sk, struct cmsghdr *cmsg,
3017 		     struct sockcm_cookie *sockc)
3018 {
3019 	u32 tsflags;
3020 
3021 	BUILD_BUG_ON(SOF_TIMESTAMPING_LAST == (1 << 31));
3022 
3023 	switch (cmsg->cmsg_type) {
3024 	case SO_MARK:
3025 		if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_RAW) &&
3026 		    !ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
3027 			return -EPERM;
3028 		if (cmsg->cmsg_len != CMSG_LEN(sizeof(u32)))
3029 			return -EINVAL;
3030 		sockc->mark = *(u32 *)CMSG_DATA(cmsg);
3031 		break;
3032 	case SO_TIMESTAMPING_OLD:
3033 	case SO_TIMESTAMPING_NEW:
3034 		if (cmsg->cmsg_len != CMSG_LEN(sizeof(u32)))
3035 			return -EINVAL;
3036 
3037 		tsflags = *(u32 *)CMSG_DATA(cmsg);
3038 		if (tsflags & ~SOF_TIMESTAMPING_TX_RECORD_MASK)
3039 			return -EINVAL;
3040 
3041 		sockc->tsflags &= ~SOF_TIMESTAMPING_TX_RECORD_MASK;
3042 		sockc->tsflags |= tsflags;
3043 		break;
3044 	case SCM_TXTIME:
3045 		if (!sock_flag(sk, SOCK_TXTIME))
3046 			return -EINVAL;
3047 		if (cmsg->cmsg_len != CMSG_LEN(sizeof(u64)))
3048 			return -EINVAL;
3049 		sockc->transmit_time = get_unaligned((u64 *)CMSG_DATA(cmsg));
3050 		break;
3051 	case SCM_TS_OPT_ID:
3052 		if (sk_is_tcp(sk))
3053 			return -EINVAL;
3054 		tsflags = READ_ONCE(sk->sk_tsflags);
3055 		if (!(tsflags & SOF_TIMESTAMPING_OPT_ID))
3056 			return -EINVAL;
3057 		if (cmsg->cmsg_len != CMSG_LEN(sizeof(u32)))
3058 			return -EINVAL;
3059 		sockc->ts_opt_id = *(u32 *)CMSG_DATA(cmsg);
3060 		sockc->tsflags |= SOCKCM_FLAG_TS_OPT_ID;
3061 		break;
3062 	/* SCM_RIGHTS and SCM_CREDENTIALS are semantically in SOL_UNIX. */
3063 	case SCM_RIGHTS:
3064 	case SCM_CREDENTIALS:
3065 		break;
3066 	case SO_PRIORITY:
3067 		if (cmsg->cmsg_len != CMSG_LEN(sizeof(u32)))
3068 			return -EINVAL;
3069 		if (!sk_set_prio_allowed(sk, *(u32 *)CMSG_DATA(cmsg)))
3070 			return -EPERM;
3071 		sockc->priority = *(u32 *)CMSG_DATA(cmsg);
3072 		break;
3073 	case SCM_DEVMEM_DMABUF:
3074 		if (cmsg->cmsg_len != CMSG_LEN(sizeof(u32)))
3075 			return -EINVAL;
3076 		sockc->dmabuf_id = *(u32 *)CMSG_DATA(cmsg);
3077 		break;
3078 	default:
3079 		return -EINVAL;
3080 	}
3081 	return 0;
3082 }
3083 EXPORT_SYMBOL(__sock_cmsg_send);
3084 
sock_cmsg_send(struct sock * sk,struct msghdr * msg,struct sockcm_cookie * sockc)3085 int sock_cmsg_send(struct sock *sk, struct msghdr *msg,
3086 		   struct sockcm_cookie *sockc)
3087 {
3088 	struct cmsghdr *cmsg;
3089 	int ret;
3090 
3091 	for_each_cmsghdr(cmsg, msg) {
3092 		if (!CMSG_OK(msg, cmsg))
3093 			return -EINVAL;
3094 		if (cmsg->cmsg_level != SOL_SOCKET)
3095 			continue;
3096 		ret = __sock_cmsg_send(sk, cmsg, sockc);
3097 		if (ret)
3098 			return ret;
3099 	}
3100 	return 0;
3101 }
3102 EXPORT_SYMBOL(sock_cmsg_send);
3103 
sk_enter_memory_pressure(struct sock * sk)3104 static void sk_enter_memory_pressure(struct sock *sk)
3105 {
3106 	if (!sk->sk_prot->enter_memory_pressure)
3107 		return;
3108 
3109 	sk->sk_prot->enter_memory_pressure(sk);
3110 }
3111 
sk_leave_memory_pressure(struct sock * sk)3112 static void sk_leave_memory_pressure(struct sock *sk)
3113 {
3114 	if (sk->sk_prot->leave_memory_pressure) {
3115 		INDIRECT_CALL_INET_1(sk->sk_prot->leave_memory_pressure,
3116 				     tcp_leave_memory_pressure, sk);
3117 	} else {
3118 		unsigned long *memory_pressure = sk->sk_prot->memory_pressure;
3119 
3120 		if (memory_pressure && READ_ONCE(*memory_pressure))
3121 			WRITE_ONCE(*memory_pressure, 0);
3122 	}
3123 }
3124 
3125 DEFINE_STATIC_KEY_FALSE(net_high_order_alloc_disable_key);
3126 
3127 /**
3128  * skb_page_frag_refill - check that a page_frag contains enough room
3129  * @sz: minimum size of the fragment we want to get
3130  * @pfrag: pointer to page_frag
3131  * @gfp: priority for memory allocation
3132  *
3133  * Note: While this allocator tries to use high order pages, there is
3134  * no guarantee that allocations succeed. Therefore, @sz MUST be
3135  * less or equal than PAGE_SIZE.
3136  */
skb_page_frag_refill(unsigned int sz,struct page_frag * pfrag,gfp_t gfp)3137 bool skb_page_frag_refill(unsigned int sz, struct page_frag *pfrag, gfp_t gfp)
3138 {
3139 	if (pfrag->page) {
3140 		if (page_ref_count(pfrag->page) == 1) {
3141 			pfrag->offset = 0;
3142 			return true;
3143 		}
3144 		if (pfrag->offset + sz <= pfrag->size)
3145 			return true;
3146 		put_page(pfrag->page);
3147 	}
3148 
3149 	pfrag->offset = 0;
3150 	if (SKB_FRAG_PAGE_ORDER &&
3151 	    !static_branch_unlikely(&net_high_order_alloc_disable_key)) {
3152 		/* Avoid direct reclaim but allow kswapd to wake */
3153 		pfrag->page = alloc_pages((gfp & ~__GFP_DIRECT_RECLAIM) |
3154 					  __GFP_COMP | __GFP_NOWARN |
3155 					  __GFP_NORETRY,
3156 					  SKB_FRAG_PAGE_ORDER);
3157 		if (likely(pfrag->page)) {
3158 			pfrag->size = PAGE_SIZE << SKB_FRAG_PAGE_ORDER;
3159 			return true;
3160 		}
3161 	}
3162 	pfrag->page = alloc_page(gfp);
3163 	if (likely(pfrag->page)) {
3164 		pfrag->size = PAGE_SIZE;
3165 		return true;
3166 	}
3167 	return false;
3168 }
3169 EXPORT_SYMBOL(skb_page_frag_refill);
3170 
sk_page_frag_refill(struct sock * sk,struct page_frag * pfrag)3171 bool sk_page_frag_refill(struct sock *sk, struct page_frag *pfrag)
3172 {
3173 	if (likely(skb_page_frag_refill(32U, pfrag, sk->sk_allocation)))
3174 		return true;
3175 
3176 	if (!sk->sk_bypass_prot_mem)
3177 		sk_enter_memory_pressure(sk);
3178 
3179 	sk_stream_moderate_sndbuf(sk);
3180 
3181 	return false;
3182 }
3183 EXPORT_SYMBOL(sk_page_frag_refill);
3184 
__lock_sock(struct sock * sk)3185 static void __lock_sock(struct sock *sk)
3186 	__releases(&sk->sk_lock.slock)
3187 	__acquires(&sk->sk_lock.slock)
3188 {
3189 	DEFINE_WAIT(wait);
3190 
3191 	for (;;) {
3192 		prepare_to_wait_exclusive(&sk->sk_lock.wq, &wait,
3193 					TASK_UNINTERRUPTIBLE);
3194 		spin_unlock_bh(&sk->sk_lock.slock);
3195 		schedule();
3196 		spin_lock_bh(&sk->sk_lock.slock);
3197 		if (!sock_owned_by_user(sk))
3198 			break;
3199 	}
3200 	finish_wait(&sk->sk_lock.wq, &wait);
3201 }
3202 
__release_sock(struct sock * sk)3203 void __release_sock(struct sock *sk)
3204 	__releases(&sk->sk_lock.slock)
3205 	__acquires(&sk->sk_lock.slock)
3206 {
3207 	struct sk_buff *skb, *next;
3208 	int nb = 0;
3209 
3210 	while ((skb = sk->sk_backlog.head) != NULL) {
3211 		sk->sk_backlog.head = sk->sk_backlog.tail = NULL;
3212 
3213 		spin_unlock_bh(&sk->sk_lock.slock);
3214 
3215 		while (1) {
3216 			next = skb->next;
3217 			prefetch(next);
3218 			DEBUG_NET_WARN_ON_ONCE(skb_dst_is_noref(skb));
3219 			skb_mark_not_on_list(skb);
3220 			sk_backlog_rcv(sk, skb);
3221 
3222 			skb = next;
3223 			if (!skb)
3224 				break;
3225 
3226 			if (!(++nb & 15))
3227 				cond_resched();
3228 		}
3229 
3230 		spin_lock_bh(&sk->sk_lock.slock);
3231 	}
3232 
3233 	/*
3234 	 * Doing the zeroing here guarantee we can not loop forever
3235 	 * while a wild producer attempts to flood us.
3236 	 */
3237 	sk->sk_backlog.len = 0;
3238 }
3239 
__sk_flush_backlog(struct sock * sk)3240 void __sk_flush_backlog(struct sock *sk)
3241 {
3242 	spin_lock_bh(&sk->sk_lock.slock);
3243 	__release_sock(sk);
3244 
3245 	if (sk->sk_prot->release_cb)
3246 		INDIRECT_CALL_INET_1(sk->sk_prot->release_cb,
3247 				     tcp_release_cb, sk);
3248 
3249 	spin_unlock_bh(&sk->sk_lock.slock);
3250 }
3251 EXPORT_SYMBOL_GPL(__sk_flush_backlog);
3252 
3253 /**
3254  * sk_wait_data - wait for data to arrive at sk_receive_queue
3255  * @sk:    sock to wait on
3256  * @timeo: for how long
3257  * @skb:   last skb seen on sk_receive_queue
3258  *
3259  * Now socket state including sk->sk_err is changed only under lock,
3260  * hence we may omit checks after joining wait queue.
3261  * We check receive queue before schedule() only as optimization;
3262  * it is very likely that release_sock() added new data.
3263  */
sk_wait_data(struct sock * sk,long * timeo,const struct sk_buff * skb)3264 int sk_wait_data(struct sock *sk, long *timeo, const struct sk_buff *skb)
3265 {
3266 	DEFINE_WAIT_FUNC(wait, woken_wake_function);
3267 	int rc;
3268 
3269 	add_wait_queue(sk_sleep(sk), &wait);
3270 	sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
3271 	rc = sk_wait_event(sk, timeo, skb_peek_tail(&sk->sk_receive_queue) != skb, &wait);
3272 	sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
3273 	remove_wait_queue(sk_sleep(sk), &wait);
3274 	return rc;
3275 }
3276 EXPORT_SYMBOL(sk_wait_data);
3277 
3278 /**
3279  *	__sk_mem_raise_allocated - increase memory_allocated
3280  *	@sk: socket
3281  *	@size: memory size to allocate
3282  *	@amt: pages to allocate
3283  *	@kind: allocation type
3284  *
3285  *	Similar to __sk_mem_schedule(), but does not update sk_forward_alloc.
3286  *
3287  *	Unlike the globally shared limits among the sockets under same protocol,
3288  *	consuming the budget of a memcg won't have direct effect on other ones.
3289  *	So be optimistic about memcg's tolerance, and leave the callers to decide
3290  *	whether or not to raise allocated through sk_under_memory_pressure() or
3291  *	its variants.
3292  */
__sk_mem_raise_allocated(struct sock * sk,int size,int amt,int kind)3293 int __sk_mem_raise_allocated(struct sock *sk, int size, int amt, int kind)
3294 {
3295 	bool memcg_enabled = false, charged = false;
3296 	struct proto *prot = sk->sk_prot;
3297 	long allocated = 0;
3298 
3299 	if (!sk->sk_bypass_prot_mem) {
3300 		sk_memory_allocated_add(sk, amt);
3301 		allocated = sk_memory_allocated(sk);
3302 	}
3303 
3304 	if (mem_cgroup_sk_enabled(sk)) {
3305 		memcg_enabled = true;
3306 		charged = mem_cgroup_sk_charge(sk, amt, gfp_memcg_charge());
3307 		if (!charged)
3308 			goto suppress_allocation;
3309 	}
3310 
3311 	if (!allocated)
3312 		return 1;
3313 
3314 	/* Under limit. */
3315 	if (allocated <= sk_prot_mem_limits(sk, 0)) {
3316 		sk_leave_memory_pressure(sk);
3317 		return 1;
3318 	}
3319 
3320 	/* Under pressure. */
3321 	if (allocated > sk_prot_mem_limits(sk, 1))
3322 		sk_enter_memory_pressure(sk);
3323 
3324 	/* Over hard limit. */
3325 	if (allocated > sk_prot_mem_limits(sk, 2))
3326 		goto suppress_allocation;
3327 
3328 	/* Guarantee minimum buffer size under pressure (either global
3329 	 * or memcg) to make sure features described in RFC 7323 (TCP
3330 	 * Extensions for High Performance) work properly.
3331 	 *
3332 	 * This rule does NOT stand when exceeds global or memcg's hard
3333 	 * limit, or else a DoS attack can be taken place by spawning
3334 	 * lots of sockets whose usage are under minimum buffer size.
3335 	 */
3336 	if (kind == SK_MEM_RECV) {
3337 		if (atomic_read(&sk->sk_rmem_alloc) < sk_get_rmem0(sk, prot))
3338 			return 1;
3339 
3340 	} else { /* SK_MEM_SEND */
3341 		int wmem0 = sk_get_wmem0(sk, prot);
3342 
3343 		if (sk->sk_type == SOCK_STREAM) {
3344 			if (sk->sk_wmem_queued < wmem0)
3345 				return 1;
3346 		} else if (refcount_read(&sk->sk_wmem_alloc) < wmem0) {
3347 				return 1;
3348 		}
3349 	}
3350 
3351 	if (sk_has_memory_pressure(sk)) {
3352 		u64 alloc;
3353 
3354 		/* The following 'average' heuristic is within the
3355 		 * scope of global accounting, so it only makes
3356 		 * sense for global memory pressure.
3357 		 */
3358 		if (!sk_under_global_memory_pressure(sk))
3359 			return 1;
3360 
3361 		/* Try to be fair among all the sockets under global
3362 		 * pressure by allowing the ones that below average
3363 		 * usage to raise.
3364 		 */
3365 		alloc = sk_sockets_allocated_read_positive(sk);
3366 		if (sk_prot_mem_limits(sk, 2) > alloc *
3367 		    sk_mem_pages(sk->sk_wmem_queued +
3368 				 atomic_read(&sk->sk_rmem_alloc) +
3369 				 sk->sk_forward_alloc))
3370 			return 1;
3371 	}
3372 
3373 suppress_allocation:
3374 
3375 	if (kind == SK_MEM_SEND && sk->sk_type == SOCK_STREAM) {
3376 		sk_stream_moderate_sndbuf(sk);
3377 
3378 		/* Fail only if socket is _under_ its sndbuf.
3379 		 * In this case we cannot block, so that we have to fail.
3380 		 */
3381 		if (sk->sk_wmem_queued + size >= sk->sk_sndbuf) {
3382 			/* Force charge with __GFP_NOFAIL */
3383 			if (memcg_enabled && !charged)
3384 				mem_cgroup_sk_charge(sk, amt,
3385 						     gfp_memcg_charge() | __GFP_NOFAIL);
3386 			return 1;
3387 		}
3388 	}
3389 
3390 	trace_sock_exceed_buf_limit(sk, prot, allocated, kind);
3391 
3392 	if (allocated)
3393 		sk_memory_allocated_sub(sk, amt);
3394 
3395 	if (charged)
3396 		mem_cgroup_sk_uncharge(sk, amt);
3397 
3398 	return 0;
3399 }
3400 
3401 /**
3402  *	__sk_mem_schedule - increase sk_forward_alloc and memory_allocated
3403  *	@sk: socket
3404  *	@size: memory size to allocate
3405  *	@kind: allocation type
3406  *
3407  *	If kind is SK_MEM_SEND, it means wmem allocation. Otherwise it means
3408  *	rmem allocation. This function assumes that protocols which have
3409  *	memory_pressure use sk_wmem_queued as write buffer accounting.
3410  */
__sk_mem_schedule(struct sock * sk,int size,int kind)3411 int __sk_mem_schedule(struct sock *sk, int size, int kind)
3412 {
3413 	int ret, amt = sk_mem_pages(size);
3414 
3415 	sk_forward_alloc_add(sk, amt << PAGE_SHIFT);
3416 	ret = __sk_mem_raise_allocated(sk, size, amt, kind);
3417 	if (!ret)
3418 		sk_forward_alloc_add(sk, -(amt << PAGE_SHIFT));
3419 	return ret;
3420 }
3421 EXPORT_SYMBOL(__sk_mem_schedule);
3422 
3423 /**
3424  *	__sk_mem_reduce_allocated - reclaim memory_allocated
3425  *	@sk: socket
3426  *	@amount: number of quanta
3427  *
3428  *	Similar to __sk_mem_reclaim(), but does not update sk_forward_alloc
3429  */
__sk_mem_reduce_allocated(struct sock * sk,int amount)3430 void __sk_mem_reduce_allocated(struct sock *sk, int amount)
3431 {
3432 	if (mem_cgroup_sk_enabled(sk))
3433 		mem_cgroup_sk_uncharge(sk, amount);
3434 
3435 	if (sk->sk_bypass_prot_mem)
3436 		return;
3437 
3438 	sk_memory_allocated_sub(sk, amount);
3439 
3440 	if (sk_under_global_memory_pressure(sk) &&
3441 	    (sk_memory_allocated(sk) < sk_prot_mem_limits(sk, 0)))
3442 		sk_leave_memory_pressure(sk);
3443 }
3444 
3445 /**
3446  *	__sk_mem_reclaim - reclaim sk_forward_alloc and memory_allocated
3447  *	@sk: socket
3448  *	@amount: number of bytes (rounded down to a PAGE_SIZE multiple)
3449  */
__sk_mem_reclaim(struct sock * sk,int amount)3450 void __sk_mem_reclaim(struct sock *sk, int amount)
3451 {
3452 	amount >>= PAGE_SHIFT;
3453 	sk_forward_alloc_add(sk, -(amount << PAGE_SHIFT));
3454 	__sk_mem_reduce_allocated(sk, amount);
3455 }
3456 EXPORT_SYMBOL(__sk_mem_reclaim);
3457 
__sk_charge(struct sock * sk,gfp_t gfp)3458 void __sk_charge(struct sock *sk, gfp_t gfp)
3459 {
3460 	int amt;
3461 
3462 	gfp |= __GFP_NOFAIL;
3463 	if (mem_cgroup_from_sk(sk)) {
3464 		/* The socket has not been accepted yet, no need
3465 		 * to look at newsk->sk_wmem_queued.
3466 		 */
3467 		amt = sk_mem_pages(sk->sk_forward_alloc +
3468 				   atomic_read(&sk->sk_rmem_alloc));
3469 		if (amt)
3470 			mem_cgroup_sk_charge(sk, amt, gfp);
3471 	}
3472 
3473 	kmem_cache_charge(sk, gfp);
3474 }
3475 
sk_set_peek_off(struct sock * sk,int val)3476 int sk_set_peek_off(struct sock *sk, int val)
3477 {
3478 	WRITE_ONCE(sk->sk_peek_off, val);
3479 	return 0;
3480 }
3481 EXPORT_SYMBOL_GPL(sk_set_peek_off);
3482 
3483 /*
3484  * Set of default routines for initialising struct proto_ops when
3485  * the protocol does not support a particular function. In certain
3486  * cases where it makes no sense for a protocol to have a "do nothing"
3487  * function, some default processing is provided.
3488  */
3489 
sock_no_bind(struct socket * sock,struct sockaddr_unsized * saddr,int len)3490 int sock_no_bind(struct socket *sock, struct sockaddr_unsized *saddr, int len)
3491 {
3492 	return -EOPNOTSUPP;
3493 }
3494 EXPORT_SYMBOL(sock_no_bind);
3495 
sock_no_connect(struct socket * sock,struct sockaddr_unsized * saddr,int len,int flags)3496 int sock_no_connect(struct socket *sock, struct sockaddr_unsized *saddr,
3497 		    int len, int flags)
3498 {
3499 	return -EOPNOTSUPP;
3500 }
3501 EXPORT_SYMBOL(sock_no_connect);
3502 
sock_no_socketpair(struct socket * sock1,struct socket * sock2)3503 int sock_no_socketpair(struct socket *sock1, struct socket *sock2)
3504 {
3505 	return -EOPNOTSUPP;
3506 }
3507 EXPORT_SYMBOL(sock_no_socketpair);
3508 
sock_no_accept(struct socket * sock,struct socket * newsock,struct proto_accept_arg * arg)3509 int sock_no_accept(struct socket *sock, struct socket *newsock,
3510 		   struct proto_accept_arg *arg)
3511 {
3512 	return -EOPNOTSUPP;
3513 }
3514 EXPORT_SYMBOL(sock_no_accept);
3515 
sock_no_getname(struct socket * sock,struct sockaddr * saddr,int peer)3516 int sock_no_getname(struct socket *sock, struct sockaddr *saddr,
3517 		    int peer)
3518 {
3519 	return -EOPNOTSUPP;
3520 }
3521 EXPORT_SYMBOL(sock_no_getname);
3522 
sock_no_ioctl(struct socket * sock,unsigned int cmd,unsigned long arg)3523 int sock_no_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
3524 {
3525 	return -EOPNOTSUPP;
3526 }
3527 EXPORT_SYMBOL(sock_no_ioctl);
3528 
sock_no_listen(struct socket * sock,int backlog)3529 int sock_no_listen(struct socket *sock, int backlog)
3530 {
3531 	return -EOPNOTSUPP;
3532 }
3533 EXPORT_SYMBOL(sock_no_listen);
3534 
sock_no_shutdown(struct socket * sock,int how)3535 int sock_no_shutdown(struct socket *sock, int how)
3536 {
3537 	return -EOPNOTSUPP;
3538 }
3539 EXPORT_SYMBOL(sock_no_shutdown);
3540 
sock_no_sendmsg(struct socket * sock,struct msghdr * m,size_t len)3541 int sock_no_sendmsg(struct socket *sock, struct msghdr *m, size_t len)
3542 {
3543 	return -EOPNOTSUPP;
3544 }
3545 EXPORT_SYMBOL(sock_no_sendmsg);
3546 
sock_no_sendmsg_locked(struct sock * sk,struct msghdr * m,size_t len)3547 int sock_no_sendmsg_locked(struct sock *sk, struct msghdr *m, size_t len)
3548 {
3549 	return -EOPNOTSUPP;
3550 }
3551 EXPORT_SYMBOL(sock_no_sendmsg_locked);
3552 
sock_no_recvmsg(struct socket * sock,struct msghdr * m,size_t len,int flags)3553 int sock_no_recvmsg(struct socket *sock, struct msghdr *m, size_t len,
3554 		    int flags)
3555 {
3556 	return -EOPNOTSUPP;
3557 }
3558 EXPORT_SYMBOL(sock_no_recvmsg);
3559 
sock_no_mmap(struct file * file,struct socket * sock,struct vm_area_struct * vma)3560 int sock_no_mmap(struct file *file, struct socket *sock, struct vm_area_struct *vma)
3561 {
3562 	/* Mirror missing mmap method error code */
3563 	return -ENODEV;
3564 }
3565 EXPORT_SYMBOL(sock_no_mmap);
3566 
3567 /*
3568  * When a file is received (via SCM_RIGHTS, etc), we must bump the
3569  * various sock-based usage counts.
3570  */
__receive_sock(struct file * file)3571 void __receive_sock(struct file *file)
3572 {
3573 	struct socket *sock;
3574 
3575 	sock = sock_from_file(file);
3576 	if (sock) {
3577 		sock_update_netprioidx(&sock->sk->sk_cgrp_data);
3578 		sock_update_classid(&sock->sk->sk_cgrp_data);
3579 	}
3580 }
3581 
3582 /*
3583  *	Default Socket Callbacks
3584  */
3585 
sock_def_wakeup(struct sock * sk)3586 static void sock_def_wakeup(struct sock *sk)
3587 {
3588 	struct socket_wq *wq;
3589 
3590 	rcu_read_lock();
3591 	wq = rcu_dereference(sk->sk_wq);
3592 	if (skwq_has_sleeper(wq))
3593 		wake_up_interruptible_all(&wq->wait);
3594 	rcu_read_unlock();
3595 }
3596 
sock_def_error_report(struct sock * sk)3597 static void sock_def_error_report(struct sock *sk)
3598 {
3599 	struct socket_wq *wq;
3600 
3601 	rcu_read_lock();
3602 	wq = rcu_dereference(sk->sk_wq);
3603 	if (skwq_has_sleeper(wq))
3604 		wake_up_interruptible_poll(&wq->wait, EPOLLERR);
3605 	sk_wake_async_rcu(sk, SOCK_WAKE_IO, POLL_ERR);
3606 	rcu_read_unlock();
3607 }
3608 
sock_def_readable(struct sock * sk)3609 void sock_def_readable(struct sock *sk)
3610 {
3611 	struct socket_wq *wq;
3612 
3613 	trace_sk_data_ready(sk);
3614 
3615 	rcu_read_lock();
3616 	wq = rcu_dereference(sk->sk_wq);
3617 	if (skwq_has_sleeper(wq))
3618 		wake_up_interruptible_sync_poll(&wq->wait, EPOLLIN | EPOLLPRI |
3619 						EPOLLRDNORM | EPOLLRDBAND);
3620 	sk_wake_async_rcu(sk, SOCK_WAKE_WAITD, POLL_IN);
3621 	rcu_read_unlock();
3622 }
3623 
sock_def_write_space(struct sock * sk)3624 static void sock_def_write_space(struct sock *sk)
3625 {
3626 	struct socket_wq *wq;
3627 
3628 	rcu_read_lock();
3629 
3630 	/* Do not wake up a writer until he can make "significant"
3631 	 * progress.  --DaveM
3632 	 */
3633 	if (sock_writeable(sk)) {
3634 		wq = rcu_dereference(sk->sk_wq);
3635 		if (skwq_has_sleeper(wq))
3636 			wake_up_interruptible_sync_poll(&wq->wait, EPOLLOUT |
3637 						EPOLLWRNORM | EPOLLWRBAND);
3638 
3639 		/* Should agree with poll, otherwise some programs break */
3640 		sk_wake_async_rcu(sk, SOCK_WAKE_SPACE, POLL_OUT);
3641 	}
3642 
3643 	rcu_read_unlock();
3644 }
3645 
3646 /* An optimised version of sock_def_write_space(), should only be called
3647  * for SOCK_RCU_FREE sockets under RCU read section and after putting
3648  * ->sk_wmem_alloc.
3649  */
sock_def_write_space_wfree(struct sock * sk,int wmem_alloc)3650 static void sock_def_write_space_wfree(struct sock *sk, int wmem_alloc)
3651 {
3652 	/* Do not wake up a writer until he can make "significant"
3653 	 * progress.  --DaveM
3654 	 */
3655 	if (__sock_writeable(sk, wmem_alloc)) {
3656 		struct socket_wq *wq = rcu_dereference(sk->sk_wq);
3657 
3658 		/* rely on refcount_sub from sock_wfree() */
3659 		smp_mb__after_atomic();
3660 		if (wq && waitqueue_active(&wq->wait))
3661 			wake_up_interruptible_sync_poll(&wq->wait, EPOLLOUT |
3662 						EPOLLWRNORM | EPOLLWRBAND);
3663 
3664 		/* Should agree with poll, otherwise some programs break */
3665 		sk_wake_async_rcu(sk, SOCK_WAKE_SPACE, POLL_OUT);
3666 	}
3667 }
3668 
sock_def_destruct(struct sock * sk)3669 static void sock_def_destruct(struct sock *sk)
3670 {
3671 }
3672 
sk_send_sigurg(struct sock * sk)3673 void sk_send_sigurg(struct sock *sk)
3674 {
3675 	if (sk->sk_socket && sk->sk_socket->file)
3676 		if (send_sigurg(sk->sk_socket->file))
3677 			sk_wake_async(sk, SOCK_WAKE_URG, POLL_PRI);
3678 }
3679 EXPORT_SYMBOL(sk_send_sigurg);
3680 
sk_reset_timer(struct sock * sk,struct timer_list * timer,unsigned long expires)3681 void sk_reset_timer(struct sock *sk, struct timer_list* timer,
3682 		    unsigned long expires)
3683 {
3684 	if (!mod_timer(timer, expires))
3685 		sock_hold(sk);
3686 }
3687 EXPORT_SYMBOL(sk_reset_timer);
3688 
sk_stop_timer(struct sock * sk,struct timer_list * timer)3689 void sk_stop_timer(struct sock *sk, struct timer_list* timer)
3690 {
3691 	if (timer_delete(timer))
3692 		__sock_put(sk);
3693 }
3694 EXPORT_SYMBOL(sk_stop_timer);
3695 
sk_stop_timer_sync(struct sock * sk,struct timer_list * timer)3696 void sk_stop_timer_sync(struct sock *sk, struct timer_list *timer)
3697 {
3698 	if (timer_delete_sync(timer))
3699 		__sock_put(sk);
3700 }
3701 EXPORT_SYMBOL(sk_stop_timer_sync);
3702 
sock_init_data_uid(struct socket * sock,struct sock * sk,kuid_t uid)3703 void sock_init_data_uid(struct socket *sock, struct sock *sk, kuid_t uid)
3704 {
3705 	sk_init_common(sk);
3706 	sk->sk_send_head	=	NULL;
3707 
3708 	timer_setup(&sk->sk_timer, NULL, 0);
3709 
3710 	sk->sk_allocation	=	GFP_KERNEL;
3711 	sk->sk_rcvbuf		=	READ_ONCE(sysctl_rmem_default);
3712 	sk->sk_sndbuf		=	READ_ONCE(sysctl_wmem_default);
3713 	sk->sk_state		=	TCP_CLOSE;
3714 	sk->sk_use_task_frag	=	true;
3715 	sk_set_socket(sk, sock);
3716 
3717 	sock_set_flag(sk, SOCK_ZAPPED);
3718 
3719 	if (sock) {
3720 		sk->sk_type	=	sock->type;
3721 		RCU_INIT_POINTER(sk->sk_wq, &sock->wq);
3722 		sock->sk	=	sk;
3723 	} else {
3724 		RCU_INIT_POINTER(sk->sk_wq, NULL);
3725 	}
3726 	sk->sk_uid	=	uid;
3727 
3728 	sk->sk_state_change	=	sock_def_wakeup;
3729 	sk->sk_data_ready	=	sock_def_readable;
3730 	sk->sk_write_space	=	sock_def_write_space;
3731 	sk->sk_error_report	=	sock_def_error_report;
3732 	sk->sk_destruct		=	sock_def_destruct;
3733 
3734 	sk->sk_frag.page	=	NULL;
3735 	sk->sk_frag.offset	=	0;
3736 	sk->sk_peek_off		=	-1;
3737 
3738 	sk->sk_peer_pid 	=	NULL;
3739 	sk->sk_peer_cred	=	NULL;
3740 	spin_lock_init(&sk->sk_peer_lock);
3741 
3742 	sk->sk_write_pending	=	0;
3743 	sk->sk_rcvlowat		=	1;
3744 	sk->sk_rcvtimeo		=	MAX_SCHEDULE_TIMEOUT;
3745 	sk->sk_sndtimeo		=	MAX_SCHEDULE_TIMEOUT;
3746 
3747 	sk->sk_stamp = SK_DEFAULT_STAMP;
3748 #if BITS_PER_LONG==32
3749 	seqlock_init(&sk->sk_stamp_seq);
3750 #endif
3751 	atomic_set(&sk->sk_zckey, 0);
3752 
3753 #ifdef CONFIG_NET_RX_BUSY_POLL
3754 	sk->sk_napi_id		=	0;
3755 	sk->sk_ll_usec		=	READ_ONCE(sysctl_net_busy_read);
3756 #endif
3757 
3758 	sk->sk_max_pacing_rate = ~0UL;
3759 	sk->sk_pacing_rate = ~0UL;
3760 	WRITE_ONCE(sk->sk_pacing_shift, 10);
3761 	sk->sk_incoming_cpu = -1;
3762 
3763 	sk_rx_queue_clear(sk);
3764 	/*
3765 	 * Before updating sk_refcnt, we must commit prior changes to memory
3766 	 * (Documentation/RCU/rculist_nulls.rst for details)
3767 	 */
3768 	smp_wmb();
3769 	refcount_set(&sk->sk_refcnt, 1);
3770 	sk_drops_reset(sk);
3771 }
3772 EXPORT_SYMBOL(sock_init_data_uid);
3773 
sock_init_data(struct socket * sock,struct sock * sk)3774 void sock_init_data(struct socket *sock, struct sock *sk)
3775 {
3776 	kuid_t uid = sock ?
3777 		SOCK_INODE(sock)->i_uid :
3778 		make_kuid(sock_net(sk)->user_ns, 0);
3779 
3780 	sock_init_data_uid(sock, sk, uid);
3781 }
3782 EXPORT_SYMBOL(sock_init_data);
3783 
lock_sock_nested(struct sock * sk,int subclass)3784 void noinline lock_sock_nested(struct sock *sk, int subclass)
3785 {
3786 	/* The sk_lock has mutex_lock() semantics here. */
3787 	mutex_acquire(&sk->sk_lock.dep_map, subclass, 0, _RET_IP_);
3788 
3789 	might_sleep();
3790 #ifdef CONFIG_64BIT
3791 	if (sizeof(struct slock_owned) == sizeof(long)) {
3792 		socket_lock_t tmp = {
3793 			.slock = __SPIN_LOCK_UNLOCKED(tmp.slock),
3794 			.owned = 1,
3795 		};
3796 		socket_lock_t old = {
3797 			.slock = __SPIN_LOCK_UNLOCKED(old.slock),
3798 			.owned = 0,
3799 		};
3800 
3801 		if (likely(try_cmpxchg(&sk->sk_lock.combined,
3802 				       &old.combined, tmp.combined)))
3803 			return;
3804 	}
3805 #endif
3806 	spin_lock_bh(&sk->sk_lock.slock);
3807 	if (unlikely(sock_owned_by_user_nocheck(sk)))
3808 		__lock_sock(sk);
3809 	sk->sk_lock.owned = 1;
3810 	spin_unlock_bh(&sk->sk_lock.slock);
3811 }
3812 EXPORT_SYMBOL(lock_sock_nested);
3813 
release_sock(struct sock * sk)3814 void release_sock(struct sock *sk)
3815 {
3816 	spin_lock_bh(&sk->sk_lock.slock);
3817 
3818 	if (unlikely(sk->sk_backlog.tail))
3819 		__release_sock(sk);
3820 
3821 	if (sk->sk_prot->release_cb) {
3822 		if (!tcp_release_cb_cond(sk))
3823 			sk->sk_prot->release_cb(sk);
3824 	}
3825 	sock_release_ownership(sk);
3826 	if (unlikely(waitqueue_active(&sk->sk_lock.wq)))
3827 		wake_up(&sk->sk_lock.wq);
3828 
3829 	spin_unlock_bh(&sk->sk_lock.slock);
3830 }
3831 EXPORT_SYMBOL(release_sock);
3832 
__lock_sock_fast(struct sock * sk)3833 bool __lock_sock_fast(struct sock *sk) __acquires(&sk->sk_lock.slock)
3834 {
3835 	might_sleep();
3836 	spin_lock_bh(&sk->sk_lock.slock);
3837 
3838 	if (likely(!sock_owned_by_user_nocheck(sk))) {
3839 		/*
3840 		 * Fast path return with bottom halves disabled and
3841 		 * sock::sk_lock.slock held.
3842 		 *
3843 		 * The 'mutex' is not contended and holding
3844 		 * sock::sk_lock.slock prevents all other lockers to
3845 		 * proceed so the corresponding unlock_sock_fast() can
3846 		 * avoid the slow path of release_sock() completely and
3847 		 * just release slock.
3848 		 *
3849 		 * From a semantical POV this is equivalent to 'acquiring'
3850 		 * the 'mutex', hence the corresponding lockdep
3851 		 * mutex_release() has to happen in the fast path of
3852 		 * unlock_sock_fast().
3853 		 */
3854 		return false;
3855 	}
3856 
3857 	__lock_sock(sk);
3858 	sk->sk_lock.owned = 1;
3859 	__acquire(&sk->sk_lock.slock);
3860 	spin_unlock_bh(&sk->sk_lock.slock);
3861 	return true;
3862 }
3863 EXPORT_SYMBOL(__lock_sock_fast);
3864 
sock_gettstamp(struct socket * sock,void __user * userstamp,bool timeval,bool time32)3865 int sock_gettstamp(struct socket *sock, void __user *userstamp,
3866 		   bool timeval, bool time32)
3867 {
3868 	struct sock *sk = sock->sk;
3869 	struct timespec64 ts;
3870 
3871 	sock_enable_timestamp(sk, SOCK_TIMESTAMP);
3872 	ts = ktime_to_timespec64(sock_read_timestamp(sk));
3873 	if (ts.tv_sec == -1)
3874 		return -ENOENT;
3875 	if (ts.tv_sec == 0) {
3876 		ktime_t kt = ktime_get_real();
3877 		sock_write_timestamp(sk, kt);
3878 		ts = ktime_to_timespec64(kt);
3879 	}
3880 
3881 	if (timeval)
3882 		ts.tv_nsec /= 1000;
3883 
3884 #ifdef CONFIG_COMPAT_32BIT_TIME
3885 	if (time32)
3886 		return put_old_timespec32(&ts, userstamp);
3887 #endif
3888 #ifdef CONFIG_SPARC64
3889 	/* beware of padding in sparc64 timeval */
3890 	if (timeval && !in_compat_syscall()) {
3891 		struct __kernel_old_timeval __user tv = {
3892 			.tv_sec = ts.tv_sec,
3893 			.tv_usec = ts.tv_nsec,
3894 		};
3895 		if (copy_to_user(userstamp, &tv, sizeof(tv)))
3896 			return -EFAULT;
3897 		return 0;
3898 	}
3899 #endif
3900 	return put_timespec64(&ts, userstamp);
3901 }
3902 EXPORT_SYMBOL(sock_gettstamp);
3903 
sock_enable_timestamp(struct sock * sk,enum sock_flags flag)3904 void sock_enable_timestamp(struct sock *sk, enum sock_flags flag)
3905 {
3906 	if (!sock_flag(sk, flag)) {
3907 		unsigned long previous_flags = sk->sk_flags;
3908 
3909 		sock_set_flag(sk, flag);
3910 		/*
3911 		 * we just set one of the two flags which require net
3912 		 * time stamping, but time stamping might have been on
3913 		 * already because of the other one
3914 		 */
3915 		if (sock_needs_netstamp(sk) &&
3916 		    !(previous_flags & SK_FLAGS_TIMESTAMP))
3917 			net_enable_timestamp();
3918 	}
3919 }
3920 
sock_recv_errqueue(struct sock * sk,struct msghdr * msg,int len,int level,int type)3921 int sock_recv_errqueue(struct sock *sk, struct msghdr *msg, int len,
3922 		       int level, int type)
3923 {
3924 	struct sock_extended_err ee;
3925 	struct sk_buff *skb;
3926 	int copied, err;
3927 
3928 	err = -EAGAIN;
3929 	skb = sock_dequeue_err_skb(sk);
3930 	if (skb == NULL)
3931 		goto out;
3932 
3933 	copied = skb->len;
3934 	if (copied > len) {
3935 		msg->msg_flags |= MSG_TRUNC;
3936 		copied = len;
3937 	}
3938 	err = skb_copy_datagram_msg(skb, 0, msg, copied);
3939 	if (err)
3940 		goto out_free_skb;
3941 
3942 	sock_recv_timestamp(msg, sk, skb);
3943 
3944 	/* We must use a bounce buffer for CONFIG_HARDENED_USERCOPY=y */
3945 	ee = SKB_EXT_ERR(skb)->ee;
3946 	put_cmsg(msg, level, type, sizeof(ee), &ee);
3947 
3948 	msg->msg_flags |= MSG_ERRQUEUE;
3949 	err = copied;
3950 
3951 out_free_skb:
3952 	kfree_skb(skb);
3953 out:
3954 	return err;
3955 }
3956 EXPORT_SYMBOL(sock_recv_errqueue);
3957 
3958 /*
3959  *	Get a socket option on an socket.
3960  *
3961  *	FIX: POSIX 1003.1g is very ambiguous here. It states that
3962  *	asynchronous errors should be reported by getsockopt. We assume
3963  *	this means if you specify SO_ERROR (otherwise what is the point of it).
3964  */
sock_common_getsockopt(struct socket * sock,int level,int optname,char __user * optval,int __user * optlen)3965 int sock_common_getsockopt(struct socket *sock, int level, int optname,
3966 			   char __user *optval, int __user *optlen)
3967 {
3968 	struct sock *sk = sock->sk;
3969 
3970 	/* IPV6_ADDRFORM can change sk->sk_prot under us. */
3971 	return READ_ONCE(sk->sk_prot)->getsockopt(sk, level, optname, optval, optlen);
3972 }
3973 EXPORT_SYMBOL(sock_common_getsockopt);
3974 
sock_common_recvmsg(struct socket * sock,struct msghdr * msg,size_t size,int flags)3975 int sock_common_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
3976 			int flags)
3977 {
3978 	struct sock *sk = sock->sk;
3979 
3980 	return sk->sk_prot->recvmsg(sk, msg, size, flags);
3981 }
3982 EXPORT_SYMBOL(sock_common_recvmsg);
3983 
3984 /*
3985  *	Set socket options on an inet socket.
3986  */
sock_common_setsockopt(struct socket * sock,int level,int optname,sockptr_t optval,unsigned int optlen)3987 int sock_common_setsockopt(struct socket *sock, int level, int optname,
3988 			   sockptr_t optval, unsigned int optlen)
3989 {
3990 	struct sock *sk = sock->sk;
3991 
3992 	/* IPV6_ADDRFORM can change sk->sk_prot under us. */
3993 	return READ_ONCE(sk->sk_prot)->setsockopt(sk, level, optname, optval, optlen);
3994 }
3995 EXPORT_SYMBOL(sock_common_setsockopt);
3996 
sk_common_release(struct sock * sk)3997 void sk_common_release(struct sock *sk)
3998 {
3999 	if (sk->sk_prot->destroy)
4000 		sk->sk_prot->destroy(sk);
4001 
4002 	/*
4003 	 * Observation: when sk_common_release is called, processes have
4004 	 * no access to socket. But net still has.
4005 	 * Step one, detach it from networking:
4006 	 *
4007 	 * A. Remove from hash tables.
4008 	 */
4009 
4010 	sk->sk_prot->unhash(sk);
4011 
4012 	/*
4013 	 * In this point socket cannot receive new packets, but it is possible
4014 	 * that some packets are in flight because some CPU runs receiver and
4015 	 * did hash table lookup before we unhashed socket. They will achieve
4016 	 * receive queue and will be purged by socket destructor.
4017 	 *
4018 	 * Also we still have packets pending on receive queue and probably,
4019 	 * our own packets waiting in device queues. sock_destroy will drain
4020 	 * receive queue, but transmitted packets will delay socket destruction
4021 	 * until the last reference will be released.
4022 	 */
4023 
4024 	sock_orphan(sk);
4025 
4026 	xfrm_sk_free_policy(sk);
4027 
4028 	sock_put(sk);
4029 }
4030 EXPORT_SYMBOL(sk_common_release);
4031 
sk_get_meminfo(const struct sock * sk,u32 * mem)4032 void sk_get_meminfo(const struct sock *sk, u32 *mem)
4033 {
4034 	memset(mem, 0, sizeof(*mem) * SK_MEMINFO_VARS);
4035 
4036 	mem[SK_MEMINFO_RMEM_ALLOC] = sk_rmem_alloc_get(sk);
4037 	mem[SK_MEMINFO_RCVBUF] = READ_ONCE(sk->sk_rcvbuf);
4038 	mem[SK_MEMINFO_WMEM_ALLOC] = sk_wmem_alloc_get(sk);
4039 	mem[SK_MEMINFO_SNDBUF] = READ_ONCE(sk->sk_sndbuf);
4040 	mem[SK_MEMINFO_FWD_ALLOC] = READ_ONCE(sk->sk_forward_alloc);
4041 	mem[SK_MEMINFO_WMEM_QUEUED] = READ_ONCE(sk->sk_wmem_queued);
4042 	mem[SK_MEMINFO_OPTMEM] = atomic_read(&sk->sk_omem_alloc);
4043 	mem[SK_MEMINFO_BACKLOG] = READ_ONCE(sk->sk_backlog.len);
4044 	mem[SK_MEMINFO_DROPS] = sk_drops_read(sk);
4045 }
4046 
4047 #ifdef CONFIG_PROC_FS
4048 static DECLARE_BITMAP(proto_inuse_idx, PROTO_INUSE_NR);
4049 
sock_prot_inuse_get(struct net * net,struct proto * prot)4050 int sock_prot_inuse_get(struct net *net, struct proto *prot)
4051 {
4052 	int cpu, idx = prot->inuse_idx;
4053 	int res = 0;
4054 
4055 	for_each_possible_cpu(cpu)
4056 		res += per_cpu_ptr(net->core.prot_inuse, cpu)->val[idx];
4057 
4058 	return res >= 0 ? res : 0;
4059 }
4060 EXPORT_SYMBOL_GPL(sock_prot_inuse_get);
4061 
sock_inuse_get(struct net * net)4062 int sock_inuse_get(struct net *net)
4063 {
4064 	int cpu, res = 0;
4065 
4066 	for_each_possible_cpu(cpu)
4067 		res += per_cpu_ptr(net->core.prot_inuse, cpu)->all;
4068 
4069 	return res;
4070 }
4071 
4072 EXPORT_SYMBOL_GPL(sock_inuse_get);
4073 
sock_inuse_init_net(struct net * net)4074 static int __net_init sock_inuse_init_net(struct net *net)
4075 {
4076 	net->core.prot_inuse = alloc_percpu(struct prot_inuse);
4077 	if (net->core.prot_inuse == NULL)
4078 		return -ENOMEM;
4079 	return 0;
4080 }
4081 
sock_inuse_exit_net(struct net * net)4082 static void __net_exit sock_inuse_exit_net(struct net *net)
4083 {
4084 	free_percpu(net->core.prot_inuse);
4085 }
4086 
4087 static struct pernet_operations net_inuse_ops = {
4088 	.init = sock_inuse_init_net,
4089 	.exit = sock_inuse_exit_net,
4090 };
4091 
net_inuse_init(void)4092 static __init int net_inuse_init(void)
4093 {
4094 	if (register_pernet_subsys(&net_inuse_ops))
4095 		panic("Cannot initialize net inuse counters");
4096 
4097 	return 0;
4098 }
4099 
4100 core_initcall(net_inuse_init);
4101 
assign_proto_idx(struct proto * prot)4102 static int assign_proto_idx(struct proto *prot)
4103 {
4104 	prot->inuse_idx = find_first_zero_bit(proto_inuse_idx, PROTO_INUSE_NR);
4105 
4106 	if (unlikely(prot->inuse_idx == PROTO_INUSE_NR)) {
4107 		pr_err("PROTO_INUSE_NR exhausted\n");
4108 		return -ENOSPC;
4109 	}
4110 
4111 	set_bit(prot->inuse_idx, proto_inuse_idx);
4112 	return 0;
4113 }
4114 
release_proto_idx(struct proto * prot)4115 static void release_proto_idx(struct proto *prot)
4116 {
4117 	if (prot->inuse_idx != PROTO_INUSE_NR)
4118 		clear_bit(prot->inuse_idx, proto_inuse_idx);
4119 }
4120 #else
assign_proto_idx(struct proto * prot)4121 static inline int assign_proto_idx(struct proto *prot)
4122 {
4123 	return 0;
4124 }
4125 
release_proto_idx(struct proto * prot)4126 static inline void release_proto_idx(struct proto *prot)
4127 {
4128 }
4129 
4130 #endif
4131 
tw_prot_cleanup(struct timewait_sock_ops * twsk_prot)4132 static void tw_prot_cleanup(struct timewait_sock_ops *twsk_prot)
4133 {
4134 	if (!twsk_prot)
4135 		return;
4136 	kfree(twsk_prot->twsk_slab_name);
4137 	twsk_prot->twsk_slab_name = NULL;
4138 	kmem_cache_destroy(twsk_prot->twsk_slab);
4139 	twsk_prot->twsk_slab = NULL;
4140 }
4141 
tw_prot_init(const struct proto * prot)4142 static int tw_prot_init(const struct proto *prot)
4143 {
4144 	struct timewait_sock_ops *twsk_prot = prot->twsk_prot;
4145 
4146 	if (!twsk_prot)
4147 		return 0;
4148 
4149 	twsk_prot->twsk_slab_name = kasprintf(GFP_KERNEL, "tw_sock_%s",
4150 					      prot->name);
4151 	if (!twsk_prot->twsk_slab_name)
4152 		return -ENOMEM;
4153 
4154 	twsk_prot->twsk_slab =
4155 		kmem_cache_create(twsk_prot->twsk_slab_name,
4156 				  twsk_prot->twsk_obj_size, 0,
4157 				  SLAB_ACCOUNT | prot->slab_flags,
4158 				  NULL);
4159 	if (!twsk_prot->twsk_slab) {
4160 		pr_crit("%s: Can't create timewait sock SLAB cache!\n",
4161 			prot->name);
4162 		return -ENOMEM;
4163 	}
4164 
4165 	return 0;
4166 }
4167 
req_prot_cleanup(struct request_sock_ops * rsk_prot)4168 static void req_prot_cleanup(struct request_sock_ops *rsk_prot)
4169 {
4170 	if (!rsk_prot)
4171 		return;
4172 	kfree(rsk_prot->slab_name);
4173 	rsk_prot->slab_name = NULL;
4174 	kmem_cache_destroy(rsk_prot->slab);
4175 	rsk_prot->slab = NULL;
4176 }
4177 
req_prot_init(const struct proto * prot)4178 static int req_prot_init(const struct proto *prot)
4179 {
4180 	struct request_sock_ops *rsk_prot = prot->rsk_prot;
4181 
4182 	if (!rsk_prot)
4183 		return 0;
4184 
4185 	rsk_prot->slab_name = kasprintf(GFP_KERNEL, "request_sock_%s",
4186 					prot->name);
4187 	if (!rsk_prot->slab_name)
4188 		return -ENOMEM;
4189 
4190 	rsk_prot->slab = kmem_cache_create(rsk_prot->slab_name,
4191 					   rsk_prot->obj_size, 0,
4192 					   SLAB_ACCOUNT | prot->slab_flags,
4193 					   NULL);
4194 
4195 	if (!rsk_prot->slab) {
4196 		pr_crit("%s: Can't create request sock SLAB cache!\n",
4197 			prot->name);
4198 		return -ENOMEM;
4199 	}
4200 	return 0;
4201 }
4202 
proto_register(struct proto * prot,int alloc_slab)4203 int proto_register(struct proto *prot, int alloc_slab)
4204 {
4205 	int ret = -ENOBUFS;
4206 
4207 	if (prot->memory_allocated && !prot->sysctl_mem) {
4208 		pr_err("%s: missing sysctl_mem\n", prot->name);
4209 		return -EINVAL;
4210 	}
4211 	if (prot->memory_allocated && !prot->per_cpu_fw_alloc) {
4212 		pr_err("%s: missing per_cpu_fw_alloc\n", prot->name);
4213 		return -EINVAL;
4214 	}
4215 	if (alloc_slab) {
4216 		struct kmem_cache_args args = {
4217 			.useroffset	= prot->useroffset,
4218 			.usersize	= prot->usersize,
4219 			.freeptr_offset = prot->freeptr_offset,
4220 			.use_freeptr_offset = !!prot->freeptr_offset,
4221 		};
4222 
4223 		prot->slab = kmem_cache_create(prot->name, prot->obj_size,
4224 					&args,
4225 					SLAB_HWCACHE_ALIGN | SLAB_ACCOUNT |
4226 					prot->slab_flags);
4227 		if (prot->slab == NULL) {
4228 			pr_crit("%s: Can't create sock SLAB cache!\n",
4229 				prot->name);
4230 			goto out;
4231 		}
4232 
4233 		if (req_prot_init(prot))
4234 			goto out_free_request_sock_slab;
4235 
4236 		if (tw_prot_init(prot))
4237 			goto out_free_timewait_sock_slab;
4238 	}
4239 
4240 	mutex_lock(&proto_list_mutex);
4241 	ret = assign_proto_idx(prot);
4242 	if (ret) {
4243 		mutex_unlock(&proto_list_mutex);
4244 		goto out_free_timewait_sock_slab;
4245 	}
4246 	list_add(&prot->node, &proto_list);
4247 	mutex_unlock(&proto_list_mutex);
4248 	return ret;
4249 
4250 out_free_timewait_sock_slab:
4251 	if (alloc_slab)
4252 		tw_prot_cleanup(prot->twsk_prot);
4253 out_free_request_sock_slab:
4254 	if (alloc_slab) {
4255 		req_prot_cleanup(prot->rsk_prot);
4256 
4257 		kmem_cache_destroy(prot->slab);
4258 		prot->slab = NULL;
4259 	}
4260 out:
4261 	return ret;
4262 }
4263 EXPORT_SYMBOL(proto_register);
4264 
proto_unregister(struct proto * prot)4265 void proto_unregister(struct proto *prot)
4266 {
4267 	mutex_lock(&proto_list_mutex);
4268 	release_proto_idx(prot);
4269 	list_del(&prot->node);
4270 	mutex_unlock(&proto_list_mutex);
4271 
4272 	kmem_cache_destroy(prot->slab);
4273 	prot->slab = NULL;
4274 
4275 	req_prot_cleanup(prot->rsk_prot);
4276 	tw_prot_cleanup(prot->twsk_prot);
4277 }
4278 EXPORT_SYMBOL(proto_unregister);
4279 
sock_load_diag_module(int family,int protocol)4280 int sock_load_diag_module(int family, int protocol)
4281 {
4282 	if (!protocol) {
4283 		if (!sock_is_registered(family))
4284 			return -ENOENT;
4285 
4286 		return request_module("net-pf-%d-proto-%d-type-%d", PF_NETLINK,
4287 				      NETLINK_SOCK_DIAG, family);
4288 	}
4289 
4290 #ifdef CONFIG_INET
4291 	if (family == AF_INET &&
4292 	    protocol != IPPROTO_RAW &&
4293 	    protocol < MAX_INET_PROTOS &&
4294 	    !rcu_access_pointer(inet_protos[protocol]))
4295 		return -ENOENT;
4296 #endif
4297 
4298 	return request_module("net-pf-%d-proto-%d-type-%d-%d", PF_NETLINK,
4299 			      NETLINK_SOCK_DIAG, family, protocol);
4300 }
4301 EXPORT_SYMBOL(sock_load_diag_module);
4302 
4303 #ifdef CONFIG_PROC_FS
proto_seq_start(struct seq_file * seq,loff_t * pos)4304 static void *proto_seq_start(struct seq_file *seq, loff_t *pos)
4305 	__acquires(proto_list_mutex)
4306 {
4307 	mutex_lock(&proto_list_mutex);
4308 	return seq_list_start_head(&proto_list, *pos);
4309 }
4310 
proto_seq_next(struct seq_file * seq,void * v,loff_t * pos)4311 static void *proto_seq_next(struct seq_file *seq, void *v, loff_t *pos)
4312 {
4313 	return seq_list_next(v, &proto_list, pos);
4314 }
4315 
proto_seq_stop(struct seq_file * seq,void * v)4316 static void proto_seq_stop(struct seq_file *seq, void *v)
4317 	__releases(proto_list_mutex)
4318 {
4319 	mutex_unlock(&proto_list_mutex);
4320 }
4321 
proto_method_implemented(const void * method)4322 static char proto_method_implemented(const void *method)
4323 {
4324 	return method == NULL ? 'n' : 'y';
4325 }
sock_prot_memory_allocated(struct proto * proto)4326 static long sock_prot_memory_allocated(struct proto *proto)
4327 {
4328 	return proto->memory_allocated != NULL ? proto_memory_allocated(proto) : -1L;
4329 }
4330 
sock_prot_memory_pressure(struct proto * proto)4331 static const char *sock_prot_memory_pressure(struct proto *proto)
4332 {
4333 	return proto->memory_pressure != NULL ?
4334 	proto_memory_pressure(proto) ? "yes" : "no" : "NI";
4335 }
4336 
proto_seq_printf(struct seq_file * seq,struct proto * proto)4337 static void proto_seq_printf(struct seq_file *seq, struct proto *proto)
4338 {
4339 
4340 	seq_printf(seq, "%-9s %4u %6d  %6ld   %-3s %6u   %-3s  %-10s "
4341 			"%2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c\n",
4342 		   proto->name,
4343 		   proto->obj_size,
4344 		   sock_prot_inuse_get(seq_file_net(seq), proto),
4345 		   sock_prot_memory_allocated(proto),
4346 		   sock_prot_memory_pressure(proto),
4347 		   proto->max_header,
4348 		   proto->slab == NULL ? "no" : "yes",
4349 		   module_name(proto->owner),
4350 		   proto_method_implemented(proto->close),
4351 		   proto_method_implemented(proto->connect),
4352 		   proto_method_implemented(proto->disconnect),
4353 		   proto_method_implemented(proto->accept),
4354 		   proto_method_implemented(proto->ioctl),
4355 		   proto_method_implemented(proto->init),
4356 		   proto_method_implemented(proto->destroy),
4357 		   proto_method_implemented(proto->shutdown),
4358 		   proto_method_implemented(proto->setsockopt),
4359 		   proto_method_implemented(proto->getsockopt),
4360 		   proto_method_implemented(proto->sendmsg),
4361 		   proto_method_implemented(proto->recvmsg),
4362 		   proto_method_implemented(proto->bind),
4363 		   proto_method_implemented(proto->backlog_rcv),
4364 		   proto_method_implemented(proto->hash),
4365 		   proto_method_implemented(proto->unhash),
4366 		   proto_method_implemented(proto->get_port),
4367 		   proto_method_implemented(proto->enter_memory_pressure));
4368 }
4369 
proto_seq_show(struct seq_file * seq,void * v)4370 static int proto_seq_show(struct seq_file *seq, void *v)
4371 {
4372 	if (v == &proto_list)
4373 		seq_printf(seq, "%-9s %-4s %-8s %-6s %-5s %-7s %-4s %-10s %s",
4374 			   "protocol",
4375 			   "size",
4376 			   "sockets",
4377 			   "memory",
4378 			   "press",
4379 			   "maxhdr",
4380 			   "slab",
4381 			   "module",
4382 			   "cl co di ac io in de sh ss gs se re bi br ha uh gp em\n");
4383 	else
4384 		proto_seq_printf(seq, list_entry(v, struct proto, node));
4385 	return 0;
4386 }
4387 
4388 static const struct seq_operations proto_seq_ops = {
4389 	.start  = proto_seq_start,
4390 	.next   = proto_seq_next,
4391 	.stop   = proto_seq_stop,
4392 	.show   = proto_seq_show,
4393 };
4394 
proto_init_net(struct net * net)4395 static __net_init int proto_init_net(struct net *net)
4396 {
4397 	if (!proc_create_net("protocols", 0444, net->proc_net, &proto_seq_ops,
4398 			sizeof(struct seq_net_private)))
4399 		return -ENOMEM;
4400 
4401 	return 0;
4402 }
4403 
proto_exit_net(struct net * net)4404 static __net_exit void proto_exit_net(struct net *net)
4405 {
4406 	remove_proc_entry("protocols", net->proc_net);
4407 }
4408 
4409 
4410 static __net_initdata struct pernet_operations proto_net_ops = {
4411 	.init = proto_init_net,
4412 	.exit = proto_exit_net,
4413 };
4414 
proto_init(void)4415 static int __init proto_init(void)
4416 {
4417 	return register_pernet_subsys(&proto_net_ops);
4418 }
4419 
4420 subsys_initcall(proto_init);
4421 
4422 #endif /* PROC_FS */
4423 
4424 #ifdef CONFIG_NET_RX_BUSY_POLL
sk_busy_loop_end(void * p,unsigned long start_time)4425 bool sk_busy_loop_end(void *p, unsigned long start_time)
4426 {
4427 	struct sock *sk = p;
4428 
4429 	if (!skb_queue_empty_lockless(&sk->sk_receive_queue))
4430 		return true;
4431 
4432 	if (sk_is_udp(sk) &&
4433 	    !skb_queue_empty_lockless(&udp_sk(sk)->reader_queue))
4434 		return true;
4435 
4436 	return sk_busy_loop_timeout(sk, start_time);
4437 }
4438 EXPORT_SYMBOL(sk_busy_loop_end);
4439 #endif /* CONFIG_NET_RX_BUSY_POLL */
4440 
sock_bind_add(struct sock * sk,struct sockaddr_unsized * addr,int addr_len)4441 int sock_bind_add(struct sock *sk, struct sockaddr_unsized *addr, int addr_len)
4442 {
4443 	if (!sk->sk_prot->bind_add)
4444 		return -EOPNOTSUPP;
4445 	return sk->sk_prot->bind_add(sk, addr, addr_len);
4446 }
4447 EXPORT_SYMBOL(sock_bind_add);
4448 
4449 /* 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)4450 int sock_ioctl_inout(struct sock *sk, unsigned int cmd,
4451 		     void __user *arg, void *karg, size_t size)
4452 {
4453 	int ret;
4454 
4455 	if (copy_from_user(karg, arg, size))
4456 		return -EFAULT;
4457 
4458 	ret = READ_ONCE(sk->sk_prot)->ioctl(sk, cmd, karg);
4459 	if (ret)
4460 		return ret;
4461 
4462 	if (copy_to_user(arg, karg, size))
4463 		return -EFAULT;
4464 
4465 	return 0;
4466 }
4467 EXPORT_SYMBOL(sock_ioctl_inout);
4468 
4469 /* This is the most common ioctl prep function, where the result (4 bytes) is
4470  * copied back to userspace if the ioctl() returns successfully. No input is
4471  * copied from userspace as input argument.
4472  */
sock_ioctl_out(struct sock * sk,unsigned int cmd,void __user * arg)4473 static int sock_ioctl_out(struct sock *sk, unsigned int cmd, void __user *arg)
4474 {
4475 	int ret, karg = 0;
4476 
4477 	ret = READ_ONCE(sk->sk_prot)->ioctl(sk, cmd, &karg);
4478 	if (ret)
4479 		return ret;
4480 
4481 	return put_user(karg, (int __user *)arg);
4482 }
4483 
4484 /* A wrapper around sock ioctls, which copies the data from userspace
4485  * (depending on the protocol/ioctl), and copies back the result to userspace.
4486  * The main motivation for this function is to pass kernel memory to the
4487  * protocol ioctl callbacks, instead of userspace memory.
4488  */
sk_ioctl(struct sock * sk,unsigned int cmd,void __user * arg)4489 int sk_ioctl(struct sock *sk, unsigned int cmd, void __user *arg)
4490 {
4491 	int rc = 1;
4492 
4493 	if (sk->sk_type == SOCK_RAW && sk->sk_family == AF_INET)
4494 		rc = ipmr_sk_ioctl(sk, cmd, arg);
4495 	else if (sk->sk_type == SOCK_RAW && sk->sk_family == AF_INET6)
4496 		rc = ip6mr_sk_ioctl(sk, cmd, arg);
4497 	else if (sk_is_phonet(sk))
4498 		rc = phonet_sk_ioctl(sk, cmd, arg);
4499 
4500 	/* If ioctl was processed, returns its value */
4501 	if (rc <= 0)
4502 		return rc;
4503 
4504 	/* Otherwise call the default handler */
4505 	return sock_ioctl_out(sk, cmd, arg);
4506 }
4507 EXPORT_SYMBOL(sk_ioctl);
4508 
sock_struct_check(void)4509 static int __init sock_struct_check(void)
4510 {
4511 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_rx, sk_drops);
4512 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_rx, sk_peek_off);
4513 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_rx, sk_error_queue);
4514 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_rx, sk_receive_queue);
4515 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_rx, sk_backlog);
4516 
4517 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_rx, sk_rx_dst);
4518 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_rx, sk_rx_dst_ifindex);
4519 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_rx, sk_rx_dst_cookie);
4520 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_rx, sk_rcvbuf);
4521 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_rx, sk_filter);
4522 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_rx, sk_wq);
4523 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_rx, sk_data_ready);
4524 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_rx, sk_rcvtimeo);
4525 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_rx, sk_rcvlowat);
4526 
4527 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_rxtx, sk_err);
4528 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_rxtx, sk_socket);
4529 #ifdef CONFIG_MEMCG
4530 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_rxtx, sk_memcg);
4531 #endif
4532 
4533 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_rxtx, sk_lock);
4534 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_rxtx, sk_reserved_mem);
4535 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_rxtx, sk_forward_alloc);
4536 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_rxtx, sk_tsflags);
4537 
4538 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_omem_alloc);
4539 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_omem_alloc);
4540 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_err_soft);
4541 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_wmem_queued);
4542 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_wmem_alloc);
4543 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_tsq_flags);
4544 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_send_head);
4545 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_write_queue);
4546 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_write_pending);
4547 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_frag);
4548 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_timer);
4549 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_pacing_rate);
4550 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_zckey);
4551 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_tskey);
4552 
4553 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_dst_pending_confirm);
4554 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_pacing_status);
4555 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_max_pacing_rate);
4556 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_sndtimeo);
4557 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_priority);
4558 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_mark);
4559 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_uid);
4560 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_protocol);
4561 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_dst_cache);
4562 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_route_caps);
4563 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_gso_type);
4564 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_gso_max_size);
4565 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_allocation);
4566 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_txhash);
4567 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_sndbuf);
4568 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_gso_max_segs);
4569 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_pacing_shift);
4570 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_use_task_frag);
4571 	return 0;
4572 }
4573 
4574 core_initcall(sock_struct_check);
4575