xref: /linux/net/core/sock.c (revision ab59a8605604f71bbbc16077270dc3f39648b7fc)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * INET		An implementation of the TCP/IP protocol suite for the LINUX
4  *		operating system.  INET is implemented using the  BSD Socket
5  *		interface as the means of communication with the user level.
6  *
7  *		Generic socket support routines. Memory allocators, socket lock/release
8  *		handler for protocols to use and generic option handler.
9  *
10  * Authors:	Ross Biro
11  *		Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
12  *		Florian La Roche, <flla@stud.uni-sb.de>
13  *		Alan Cox, <A.Cox@swansea.ac.uk>
14  *
15  * Fixes:
16  *		Alan Cox	: 	Numerous verify_area() problems
17  *		Alan Cox	:	Connecting on a connecting socket
18  *					now returns an error for tcp.
19  *		Alan Cox	:	sock->protocol is set correctly.
20  *					and is not sometimes left as 0.
21  *		Alan Cox	:	connect handles icmp errors on a
22  *					connect properly. Unfortunately there
23  *					is a restart syscall nasty there. I
24  *					can't match BSD without hacking the C
25  *					library. Ideas urgently sought!
26  *		Alan Cox	:	Disallow bind() to addresses that are
27  *					not ours - especially broadcast ones!!
28  *		Alan Cox	:	Socket 1024 _IS_ ok for users. (fencepost)
29  *		Alan Cox	:	sock_wfree/sock_rfree don't destroy sockets,
30  *					instead they leave that for the DESTROY timer.
31  *		Alan Cox	:	Clean up error flag in accept
32  *		Alan Cox	:	TCP ack handling is buggy, the DESTROY timer
33  *					was buggy. Put a remove_sock() in the handler
34  *					for memory when we hit 0. Also altered the timer
35  *					code. The ACK stuff can wait and needs major
36  *					TCP layer surgery.
37  *		Alan Cox	:	Fixed TCP ack bug, removed remove sock
38  *					and fixed timer/inet_bh race.
39  *		Alan Cox	:	Added zapped flag for TCP
40  *		Alan Cox	:	Move kfree_skb into skbuff.c and tidied up surplus code
41  *		Alan Cox	:	for new sk_buff allocations wmalloc/rmalloc now call alloc_skb
42  *		Alan Cox	:	kfree_s calls now are kfree_skbmem so we can track skb resources
43  *		Alan Cox	:	Supports socket option broadcast now as does udp. Packet and raw need fixing.
44  *		Alan Cox	:	Added RCVBUF,SNDBUF size setting. It suddenly occurred to me how easy it was so...
45  *		Rick Sladkey	:	Relaxed UDP rules for matching packets.
46  *		C.E.Hawkins	:	IFF_PROMISC/SIOCGHWADDR support
47  *	Pauline Middelink	:	identd support
48  *		Alan Cox	:	Fixed connect() taking signals I think.
49  *		Alan Cox	:	SO_LINGER supported
50  *		Alan Cox	:	Error reporting fixes
51  *		Anonymous	:	inet_create tidied up (sk->reuse setting)
52  *		Alan Cox	:	inet sockets don't set sk->type!
53  *		Alan Cox	:	Split socket option code
54  *		Alan Cox	:	Callbacks
55  *		Alan Cox	:	Nagle flag for Charles & Johannes stuff
56  *		Alex		:	Removed restriction on inet fioctl
57  *		Alan Cox	:	Splitting INET from NET core
58  *		Alan Cox	:	Fixed bogus SO_TYPE handling in getsockopt()
59  *		Adam Caldwell	:	Missing return in SO_DONTROUTE/SO_DEBUG code
60  *		Alan Cox	:	Split IP from generic code
61  *		Alan Cox	:	New kfree_skbmem()
62  *		Alan Cox	:	Make SO_DEBUG superuser only.
63  *		Alan Cox	:	Allow anyone to clear SO_DEBUG
64  *					(compatibility fix)
65  *		Alan Cox	:	Added optimistic memory grabbing for AF_UNIX throughput.
66  *		Alan Cox	:	Allocator for a socket is settable.
67  *		Alan Cox	:	SO_ERROR includes soft errors.
68  *		Alan Cox	:	Allow NULL arguments on some SO_ opts
69  *		Alan Cox	: 	Generic socket allocation to make hooks
70  *					easier (suggested by Craig Metz).
71  *		Michael Pall	:	SO_ERROR returns positive errno again
72  *              Steve Whitehouse:       Added default destructor to free
73  *                                      protocol private data.
74  *              Steve Whitehouse:       Added various other default routines
75  *                                      common to several socket families.
76  *              Chris Evans     :       Call suser() check last on F_SETOWN
77  *		Jay Schulist	:	Added SO_ATTACH_FILTER and SO_DETACH_FILTER.
78  *		Andi Kleen	:	Add sock_kmalloc()/sock_kfree_s()
79  *		Andi Kleen	:	Fix write_space callback
80  *		Chris Evans	:	Security fixes - signedness again
81  *		Arnaldo C. Melo :       cleanups, use skb_queue_purge
82  *
83  * To Fix:
84  */
85 
86 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
87 
88 #include <linux/unaligned.h>
89 #include <linux/capability.h>
90 #include <linux/errno.h>
91 #include <linux/errqueue.h>
92 #include <linux/types.h>
93 #include <linux/socket.h>
94 #include <linux/in.h>
95 #include <linux/kernel.h>
96 #include <linux/module.h>
97 #include <linux/proc_fs.h>
98 #include <linux/seq_file.h>
99 #include <linux/sched.h>
100 #include <linux/sched/mm.h>
101 #include <linux/timer.h>
102 #include <linux/string.h>
103 #include <linux/sockios.h>
104 #include <linux/net.h>
105 #include <linux/mm.h>
106 #include <linux/slab.h>
107 #include <linux/interrupt.h>
108 #include <linux/poll.h>
109 #include <linux/tcp.h>
110 #include <linux/udp.h>
111 #include <linux/init.h>
112 #include <linux/highmem.h>
113 #include <linux/user_namespace.h>
114 #include <linux/static_key.h>
115 #include <linux/memcontrol.h>
116 #include <linux/prefetch.h>
117 #include <linux/compat.h>
118 #include <linux/mroute.h>
119 #include <linux/mroute6.h>
120 #include <linux/icmpv6.h>
121 
122 #include <linux/uaccess.h>
123 
124 #include <linux/netdevice.h>
125 #include <net/protocol.h>
126 #include <linux/skbuff.h>
127 #include <linux/skbuff_ref.h>
128 #include <net/net_namespace.h>
129 #include <net/request_sock.h>
130 #include <net/sock.h>
131 #include <net/proto_memory.h>
132 #include <linux/net_tstamp.h>
133 #include <net/xfrm.h>
134 #include <linux/ipsec.h>
135 #include <net/cls_cgroup.h>
136 #include <net/netprio_cgroup.h>
137 #include <linux/sock_diag.h>
138 
139 #include <linux/filter.h>
140 #include <net/sock_reuseport.h>
141 #include <net/bpf_sk_storage.h>
142 
143 #include <trace/events/sock.h>
144 
145 #include <net/tcp.h>
146 #include <net/busy_poll.h>
147 #include <net/phonet/phonet.h>
148 
149 #include <linux/ethtool.h>
150 
151 #include "dev.h"
152 
153 static DEFINE_MUTEX(proto_list_mutex);
154 static LIST_HEAD(proto_list);
155 
156 static void sock_def_write_space_wfree(struct sock *sk);
157 static void sock_def_write_space(struct sock *sk);
158 
159 /**
160  * sk_ns_capable - General socket capability test
161  * @sk: Socket to use a capability on or through
162  * @user_ns: The user namespace of the capability to use
163  * @cap: The capability to use
164  *
165  * Test to see if the opener of the socket had when the socket was
166  * created and the current process has the capability @cap in the user
167  * namespace @user_ns.
168  */
sk_ns_capable(const struct sock * sk,struct user_namespace * user_ns,int cap)169 bool sk_ns_capable(const struct sock *sk,
170 		   struct user_namespace *user_ns, int cap)
171 {
172 	return file_ns_capable(sk->sk_socket->file, user_ns, cap) &&
173 		ns_capable(user_ns, cap);
174 }
175 EXPORT_SYMBOL(sk_ns_capable);
176 
177 /**
178  * sk_capable - Socket global capability test
179  * @sk: Socket to use a capability on or through
180  * @cap: The global capability to use
181  *
182  * Test to see if the opener of the socket had when the socket was
183  * created and the current process has the capability @cap in all user
184  * namespaces.
185  */
sk_capable(const struct sock * sk,int cap)186 bool sk_capable(const struct sock *sk, int cap)
187 {
188 	return sk_ns_capable(sk, &init_user_ns, cap);
189 }
190 EXPORT_SYMBOL(sk_capable);
191 
192 /**
193  * sk_net_capable - Network namespace socket capability test
194  * @sk: Socket to use a capability on or through
195  * @cap: The capability to use
196  *
197  * Test to see if the opener of the socket had when the socket was created
198  * and the current process has the capability @cap over the network namespace
199  * the socket is a member of.
200  */
sk_net_capable(const struct sock * sk,int cap)201 bool sk_net_capable(const struct sock *sk, int cap)
202 {
203 	return sk_ns_capable(sk, sock_net(sk)->user_ns, cap);
204 }
205 EXPORT_SYMBOL(sk_net_capable);
206 
207 /*
208  * Each address family might have different locking rules, so we have
209  * one slock key per address family and separate keys for internal and
210  * userspace sockets.
211  */
212 static struct lock_class_key af_family_keys[AF_MAX];
213 static struct lock_class_key af_family_kern_keys[AF_MAX];
214 static struct lock_class_key af_family_slock_keys[AF_MAX];
215 static struct lock_class_key af_family_kern_slock_keys[AF_MAX];
216 
217 /*
218  * Make lock validator output more readable. (we pre-construct these
219  * strings build-time, so that runtime initialization of socket
220  * locks is fast):
221  */
222 
223 #define _sock_locks(x)						  \
224   x "AF_UNSPEC",	x "AF_UNIX"     ,	x "AF_INET"     , \
225   x "AF_AX25"  ,	x "AF_IPX"      ,	x "AF_APPLETALK", \
226   x "AF_NETROM",	x "AF_BRIDGE"   ,	x "AF_ATMPVC"   , \
227   x "AF_X25"   ,	x "AF_INET6"    ,	x "AF_ROSE"     , \
228   x "AF_DECnet",	x "AF_NETBEUI"  ,	x "AF_SECURITY" , \
229   x "AF_KEY"   ,	x "AF_NETLINK"  ,	x "AF_PACKET"   , \
230   x "AF_ASH"   ,	x "AF_ECONET"   ,	x "AF_ATMSVC"   , \
231   x "AF_RDS"   ,	x "AF_SNA"      ,	x "AF_IRDA"     , \
232   x "AF_PPPOX" ,	x "AF_WANPIPE"  ,	x "AF_LLC"      , \
233   x "27"       ,	x "28"          ,	x "AF_CAN"      , \
234   x "AF_TIPC"  ,	x "AF_BLUETOOTH",	x "IUCV"        , \
235   x "AF_RXRPC" ,	x "AF_ISDN"     ,	x "AF_PHONET"   , \
236   x "AF_IEEE802154",	x "AF_CAIF"	,	x "AF_ALG"      , \
237   x "AF_NFC"   ,	x "AF_VSOCK"    ,	x "AF_KCM"      , \
238   x "AF_QIPCRTR",	x "AF_SMC"	,	x "AF_XDP"	, \
239   x "AF_MCTP"  , \
240   x "AF_MAX"
241 
242 static const char *const af_family_key_strings[AF_MAX+1] = {
243 	_sock_locks("sk_lock-")
244 };
245 static const char *const af_family_slock_key_strings[AF_MAX+1] = {
246 	_sock_locks("slock-")
247 };
248 static const char *const af_family_clock_key_strings[AF_MAX+1] = {
249 	_sock_locks("clock-")
250 };
251 
252 static const char *const af_family_kern_key_strings[AF_MAX+1] = {
253 	_sock_locks("k-sk_lock-")
254 };
255 static const char *const af_family_kern_slock_key_strings[AF_MAX+1] = {
256 	_sock_locks("k-slock-")
257 };
258 static const char *const af_family_kern_clock_key_strings[AF_MAX+1] = {
259 	_sock_locks("k-clock-")
260 };
261 static const char *const af_family_rlock_key_strings[AF_MAX+1] = {
262 	_sock_locks("rlock-")
263 };
264 static const char *const af_family_wlock_key_strings[AF_MAX+1] = {
265 	_sock_locks("wlock-")
266 };
267 static const char *const af_family_elock_key_strings[AF_MAX+1] = {
268 	_sock_locks("elock-")
269 };
270 
271 /*
272  * sk_callback_lock and sk queues locking rules are per-address-family,
273  * so split the lock classes by using a per-AF key:
274  */
275 static struct lock_class_key af_callback_keys[AF_MAX];
276 static struct lock_class_key af_rlock_keys[AF_MAX];
277 static struct lock_class_key af_wlock_keys[AF_MAX];
278 static struct lock_class_key af_elock_keys[AF_MAX];
279 static struct lock_class_key af_kern_callback_keys[AF_MAX];
280 
281 /* Run time adjustable parameters. */
282 __u32 sysctl_wmem_max __read_mostly = SK_WMEM_MAX;
283 EXPORT_SYMBOL(sysctl_wmem_max);
284 __u32 sysctl_rmem_max __read_mostly = SK_RMEM_MAX;
285 EXPORT_SYMBOL(sysctl_rmem_max);
286 __u32 sysctl_wmem_default __read_mostly = SK_WMEM_MAX;
287 __u32 sysctl_rmem_default __read_mostly = SK_RMEM_MAX;
288 
289 DEFINE_STATIC_KEY_FALSE(memalloc_socks_key);
290 EXPORT_SYMBOL_GPL(memalloc_socks_key);
291 
292 /**
293  * sk_set_memalloc - sets %SOCK_MEMALLOC
294  * @sk: socket to set it on
295  *
296  * Set %SOCK_MEMALLOC on a socket for access to emergency reserves.
297  * It's the responsibility of the admin to adjust min_free_kbytes
298  * to meet the requirements
299  */
sk_set_memalloc(struct sock * sk)300 void sk_set_memalloc(struct sock *sk)
301 {
302 	sock_set_flag(sk, SOCK_MEMALLOC);
303 	sk->sk_allocation |= __GFP_MEMALLOC;
304 	static_branch_inc(&memalloc_socks_key);
305 }
306 EXPORT_SYMBOL_GPL(sk_set_memalloc);
307 
sk_clear_memalloc(struct sock * sk)308 void sk_clear_memalloc(struct sock *sk)
309 {
310 	sock_reset_flag(sk, SOCK_MEMALLOC);
311 	sk->sk_allocation &= ~__GFP_MEMALLOC;
312 	static_branch_dec(&memalloc_socks_key);
313 
314 	/*
315 	 * SOCK_MEMALLOC is allowed to ignore rmem limits to ensure forward
316 	 * progress of swapping. SOCK_MEMALLOC may be cleared while
317 	 * it has rmem allocations due to the last swapfile being deactivated
318 	 * but there is a risk that the socket is unusable due to exceeding
319 	 * the rmem limits. Reclaim the reserves and obey rmem limits again.
320 	 */
321 	sk_mem_reclaim(sk);
322 }
323 EXPORT_SYMBOL_GPL(sk_clear_memalloc);
324 
__sk_backlog_rcv(struct sock * sk,struct sk_buff * skb)325 int __sk_backlog_rcv(struct sock *sk, struct sk_buff *skb)
326 {
327 	int ret;
328 	unsigned int noreclaim_flag;
329 
330 	/* these should have been dropped before queueing */
331 	BUG_ON(!sock_flag(sk, SOCK_MEMALLOC));
332 
333 	noreclaim_flag = memalloc_noreclaim_save();
334 	ret = INDIRECT_CALL_INET(sk->sk_backlog_rcv,
335 				 tcp_v6_do_rcv,
336 				 tcp_v4_do_rcv,
337 				 sk, skb);
338 	memalloc_noreclaim_restore(noreclaim_flag);
339 
340 	return ret;
341 }
342 EXPORT_SYMBOL(__sk_backlog_rcv);
343 
sk_error_report(struct sock * sk)344 void sk_error_report(struct sock *sk)
345 {
346 	sk->sk_error_report(sk);
347 
348 	switch (sk->sk_family) {
349 	case AF_INET:
350 		fallthrough;
351 	case AF_INET6:
352 		trace_inet_sk_error_report(sk);
353 		break;
354 	default:
355 		break;
356 	}
357 }
358 EXPORT_SYMBOL(sk_error_report);
359 
sock_get_timeout(long timeo,void * optval,bool old_timeval)360 int sock_get_timeout(long timeo, void *optval, bool old_timeval)
361 {
362 	struct __kernel_sock_timeval tv;
363 
364 	if (timeo == MAX_SCHEDULE_TIMEOUT) {
365 		tv.tv_sec = 0;
366 		tv.tv_usec = 0;
367 	} else {
368 		tv.tv_sec = timeo / HZ;
369 		tv.tv_usec = ((timeo % HZ) * USEC_PER_SEC) / HZ;
370 	}
371 
372 	if (old_timeval && in_compat_syscall() && !COMPAT_USE_64BIT_TIME) {
373 		struct old_timeval32 tv32 = { tv.tv_sec, tv.tv_usec };
374 		*(struct old_timeval32 *)optval = tv32;
375 		return sizeof(tv32);
376 	}
377 
378 	if (old_timeval) {
379 		struct __kernel_old_timeval old_tv;
380 		old_tv.tv_sec = tv.tv_sec;
381 		old_tv.tv_usec = tv.tv_usec;
382 		*(struct __kernel_old_timeval *)optval = old_tv;
383 		return sizeof(old_tv);
384 	}
385 
386 	*(struct __kernel_sock_timeval *)optval = tv;
387 	return sizeof(tv);
388 }
389 EXPORT_SYMBOL(sock_get_timeout);
390 
sock_copy_user_timeval(struct __kernel_sock_timeval * tv,sockptr_t optval,int optlen,bool old_timeval)391 int sock_copy_user_timeval(struct __kernel_sock_timeval *tv,
392 			   sockptr_t optval, int optlen, bool old_timeval)
393 {
394 	if (old_timeval && in_compat_syscall() && !COMPAT_USE_64BIT_TIME) {
395 		struct old_timeval32 tv32;
396 
397 		if (optlen < sizeof(tv32))
398 			return -EINVAL;
399 
400 		if (copy_from_sockptr(&tv32, optval, sizeof(tv32)))
401 			return -EFAULT;
402 		tv->tv_sec = tv32.tv_sec;
403 		tv->tv_usec = tv32.tv_usec;
404 	} else if (old_timeval) {
405 		struct __kernel_old_timeval old_tv;
406 
407 		if (optlen < sizeof(old_tv))
408 			return -EINVAL;
409 		if (copy_from_sockptr(&old_tv, optval, sizeof(old_tv)))
410 			return -EFAULT;
411 		tv->tv_sec = old_tv.tv_sec;
412 		tv->tv_usec = old_tv.tv_usec;
413 	} else {
414 		if (optlen < sizeof(*tv))
415 			return -EINVAL;
416 		if (copy_from_sockptr(tv, optval, sizeof(*tv)))
417 			return -EFAULT;
418 	}
419 
420 	return 0;
421 }
422 EXPORT_SYMBOL(sock_copy_user_timeval);
423 
sock_set_timeout(long * timeo_p,sockptr_t optval,int optlen,bool old_timeval)424 static int sock_set_timeout(long *timeo_p, sockptr_t optval, int optlen,
425 			    bool old_timeval)
426 {
427 	struct __kernel_sock_timeval tv;
428 	int err = sock_copy_user_timeval(&tv, optval, optlen, old_timeval);
429 	long val;
430 
431 	if (err)
432 		return err;
433 
434 	if (tv.tv_usec < 0 || tv.tv_usec >= USEC_PER_SEC)
435 		return -EDOM;
436 
437 	if (tv.tv_sec < 0) {
438 		static int warned __read_mostly;
439 
440 		WRITE_ONCE(*timeo_p, 0);
441 		if (warned < 10 && net_ratelimit()) {
442 			warned++;
443 			pr_info("%s: `%s' (pid %d) tries to set negative timeout\n",
444 				__func__, current->comm, task_pid_nr(current));
445 		}
446 		return 0;
447 	}
448 	val = MAX_SCHEDULE_TIMEOUT;
449 	if ((tv.tv_sec || tv.tv_usec) &&
450 	    (tv.tv_sec < (MAX_SCHEDULE_TIMEOUT / HZ - 1)))
451 		val = tv.tv_sec * HZ + DIV_ROUND_UP((unsigned long)tv.tv_usec,
452 						    USEC_PER_SEC / HZ);
453 	WRITE_ONCE(*timeo_p, val);
454 	return 0;
455 }
456 
sk_set_prio_allowed(const struct sock * sk,int val)457 static bool sk_set_prio_allowed(const struct sock *sk, int val)
458 {
459 	return ((val >= TC_PRIO_BESTEFFORT && val <= TC_PRIO_INTERACTIVE) ||
460 		sockopt_ns_capable(sock_net(sk)->user_ns, CAP_NET_RAW) ||
461 		sockopt_ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN));
462 }
463 
sock_needs_netstamp(const struct sock * sk)464 static bool sock_needs_netstamp(const struct sock *sk)
465 {
466 	switch (sk->sk_family) {
467 	case AF_UNSPEC:
468 	case AF_UNIX:
469 		return false;
470 	default:
471 		return true;
472 	}
473 }
474 
sock_disable_timestamp(struct sock * sk,unsigned long flags)475 static void sock_disable_timestamp(struct sock *sk, unsigned long flags)
476 {
477 	if (sk->sk_flags & flags) {
478 		sk->sk_flags &= ~flags;
479 		if (sock_needs_netstamp(sk) &&
480 		    !(sk->sk_flags & SK_FLAGS_TIMESTAMP))
481 			net_disable_timestamp();
482 	}
483 }
484 
485 
__sock_queue_rcv_skb(struct sock * sk,struct sk_buff * skb)486 int __sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
487 {
488 	unsigned long flags;
489 	struct sk_buff_head *list = &sk->sk_receive_queue;
490 
491 	if (atomic_read(&sk->sk_rmem_alloc) >= READ_ONCE(sk->sk_rcvbuf)) {
492 		atomic_inc(&sk->sk_drops);
493 		trace_sock_rcvqueue_full(sk, skb);
494 		return -ENOMEM;
495 	}
496 
497 	if (!sk_rmem_schedule(sk, skb, skb->truesize)) {
498 		atomic_inc(&sk->sk_drops);
499 		return -ENOBUFS;
500 	}
501 
502 	skb->dev = NULL;
503 	skb_set_owner_r(skb, sk);
504 
505 	/* we escape from rcu protected region, make sure we dont leak
506 	 * a norefcounted dst
507 	 */
508 	skb_dst_force(skb);
509 
510 	spin_lock_irqsave(&list->lock, flags);
511 	sock_skb_set_dropcount(sk, skb);
512 	__skb_queue_tail(list, skb);
513 	spin_unlock_irqrestore(&list->lock, flags);
514 
515 	if (!sock_flag(sk, SOCK_DEAD))
516 		sk->sk_data_ready(sk);
517 	return 0;
518 }
519 EXPORT_SYMBOL(__sock_queue_rcv_skb);
520 
sock_queue_rcv_skb_reason(struct sock * sk,struct sk_buff * skb,enum skb_drop_reason * reason)521 int sock_queue_rcv_skb_reason(struct sock *sk, struct sk_buff *skb,
522 			      enum skb_drop_reason *reason)
523 {
524 	enum skb_drop_reason drop_reason;
525 	int err;
526 
527 	err = sk_filter(sk, skb);
528 	if (err) {
529 		drop_reason = SKB_DROP_REASON_SOCKET_FILTER;
530 		goto out;
531 	}
532 	err = __sock_queue_rcv_skb(sk, skb);
533 	switch (err) {
534 	case -ENOMEM:
535 		drop_reason = SKB_DROP_REASON_SOCKET_RCVBUFF;
536 		break;
537 	case -ENOBUFS:
538 		drop_reason = SKB_DROP_REASON_PROTO_MEM;
539 		break;
540 	default:
541 		drop_reason = SKB_NOT_DROPPED_YET;
542 		break;
543 	}
544 out:
545 	if (reason)
546 		*reason = drop_reason;
547 	return err;
548 }
549 EXPORT_SYMBOL(sock_queue_rcv_skb_reason);
550 
__sk_receive_skb(struct sock * sk,struct sk_buff * skb,const int nested,unsigned int trim_cap,bool refcounted)551 int __sk_receive_skb(struct sock *sk, struct sk_buff *skb,
552 		     const int nested, unsigned int trim_cap, bool refcounted)
553 {
554 	int rc = NET_RX_SUCCESS;
555 
556 	if (sk_filter_trim_cap(sk, skb, trim_cap))
557 		goto discard_and_relse;
558 
559 	skb->dev = NULL;
560 
561 	if (sk_rcvqueues_full(sk, READ_ONCE(sk->sk_rcvbuf))) {
562 		atomic_inc(&sk->sk_drops);
563 		goto discard_and_relse;
564 	}
565 	if (nested)
566 		bh_lock_sock_nested(sk);
567 	else
568 		bh_lock_sock(sk);
569 	if (!sock_owned_by_user(sk)) {
570 		/*
571 		 * trylock + unlock semantics:
572 		 */
573 		mutex_acquire(&sk->sk_lock.dep_map, 0, 1, _RET_IP_);
574 
575 		rc = sk_backlog_rcv(sk, skb);
576 
577 		mutex_release(&sk->sk_lock.dep_map, _RET_IP_);
578 	} else if (sk_add_backlog(sk, skb, READ_ONCE(sk->sk_rcvbuf))) {
579 		bh_unlock_sock(sk);
580 		atomic_inc(&sk->sk_drops);
581 		goto discard_and_relse;
582 	}
583 
584 	bh_unlock_sock(sk);
585 out:
586 	if (refcounted)
587 		sock_put(sk);
588 	return rc;
589 discard_and_relse:
590 	kfree_skb(skb);
591 	goto out;
592 }
593 EXPORT_SYMBOL(__sk_receive_skb);
594 
595 INDIRECT_CALLABLE_DECLARE(struct dst_entry *ip6_dst_check(struct dst_entry *,
596 							  u32));
597 INDIRECT_CALLABLE_DECLARE(struct dst_entry *ipv4_dst_check(struct dst_entry *,
598 							   u32));
__sk_dst_check(struct sock * sk,u32 cookie)599 struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie)
600 {
601 	struct dst_entry *dst = __sk_dst_get(sk);
602 
603 	if (dst && dst->obsolete &&
604 	    INDIRECT_CALL_INET(dst->ops->check, ip6_dst_check, ipv4_dst_check,
605 			       dst, cookie) == NULL) {
606 		sk_tx_queue_clear(sk);
607 		WRITE_ONCE(sk->sk_dst_pending_confirm, 0);
608 		RCU_INIT_POINTER(sk->sk_dst_cache, NULL);
609 		dst_release(dst);
610 		return NULL;
611 	}
612 
613 	return dst;
614 }
615 EXPORT_SYMBOL(__sk_dst_check);
616 
sk_dst_check(struct sock * sk,u32 cookie)617 struct dst_entry *sk_dst_check(struct sock *sk, u32 cookie)
618 {
619 	struct dst_entry *dst = sk_dst_get(sk);
620 
621 	if (dst && dst->obsolete &&
622 	    INDIRECT_CALL_INET(dst->ops->check, ip6_dst_check, ipv4_dst_check,
623 			       dst, cookie) == NULL) {
624 		sk_dst_reset(sk);
625 		dst_release(dst);
626 		return NULL;
627 	}
628 
629 	return dst;
630 }
631 EXPORT_SYMBOL(sk_dst_check);
632 
sock_bindtoindex_locked(struct sock * sk,int ifindex)633 static int sock_bindtoindex_locked(struct sock *sk, int ifindex)
634 {
635 	int ret = -ENOPROTOOPT;
636 #ifdef CONFIG_NETDEVICES
637 	struct net *net = sock_net(sk);
638 
639 	/* Sorry... */
640 	ret = -EPERM;
641 	if (sk->sk_bound_dev_if && !ns_capable(net->user_ns, CAP_NET_RAW))
642 		goto out;
643 
644 	ret = -EINVAL;
645 	if (ifindex < 0)
646 		goto out;
647 
648 	/* Paired with all READ_ONCE() done locklessly. */
649 	WRITE_ONCE(sk->sk_bound_dev_if, ifindex);
650 
651 	if (sk->sk_prot->rehash)
652 		sk->sk_prot->rehash(sk);
653 	sk_dst_reset(sk);
654 
655 	ret = 0;
656 
657 out:
658 #endif
659 
660 	return ret;
661 }
662 
sock_bindtoindex(struct sock * sk,int ifindex,bool lock_sk)663 int sock_bindtoindex(struct sock *sk, int ifindex, bool lock_sk)
664 {
665 	int ret;
666 
667 	if (lock_sk)
668 		lock_sock(sk);
669 	ret = sock_bindtoindex_locked(sk, ifindex);
670 	if (lock_sk)
671 		release_sock(sk);
672 
673 	return ret;
674 }
675 EXPORT_SYMBOL(sock_bindtoindex);
676 
sock_setbindtodevice(struct sock * sk,sockptr_t optval,int optlen)677 static int sock_setbindtodevice(struct sock *sk, sockptr_t optval, int optlen)
678 {
679 	int ret = -ENOPROTOOPT;
680 #ifdef CONFIG_NETDEVICES
681 	struct net *net = sock_net(sk);
682 	char devname[IFNAMSIZ];
683 	int index;
684 
685 	ret = -EINVAL;
686 	if (optlen < 0)
687 		goto out;
688 
689 	/* Bind this socket to a particular device like "eth0",
690 	 * as specified in the passed interface name. If the
691 	 * name is "" or the option length is zero the socket
692 	 * is not bound.
693 	 */
694 	if (optlen > IFNAMSIZ - 1)
695 		optlen = IFNAMSIZ - 1;
696 	memset(devname, 0, sizeof(devname));
697 
698 	ret = -EFAULT;
699 	if (copy_from_sockptr(devname, optval, optlen))
700 		goto out;
701 
702 	index = 0;
703 	if (devname[0] != '\0') {
704 		struct net_device *dev;
705 
706 		rcu_read_lock();
707 		dev = dev_get_by_name_rcu(net, devname);
708 		if (dev)
709 			index = dev->ifindex;
710 		rcu_read_unlock();
711 		ret = -ENODEV;
712 		if (!dev)
713 			goto out;
714 	}
715 
716 	sockopt_lock_sock(sk);
717 	ret = sock_bindtoindex_locked(sk, index);
718 	sockopt_release_sock(sk);
719 out:
720 #endif
721 
722 	return ret;
723 }
724 
sock_getbindtodevice(struct sock * sk,sockptr_t optval,sockptr_t optlen,int len)725 static int sock_getbindtodevice(struct sock *sk, sockptr_t optval,
726 				sockptr_t optlen, int len)
727 {
728 	int ret = -ENOPROTOOPT;
729 #ifdef CONFIG_NETDEVICES
730 	int bound_dev_if = READ_ONCE(sk->sk_bound_dev_if);
731 	struct net *net = sock_net(sk);
732 	char devname[IFNAMSIZ];
733 
734 	if (bound_dev_if == 0) {
735 		len = 0;
736 		goto zero;
737 	}
738 
739 	ret = -EINVAL;
740 	if (len < IFNAMSIZ)
741 		goto out;
742 
743 	ret = netdev_get_name(net, devname, bound_dev_if);
744 	if (ret)
745 		goto out;
746 
747 	len = strlen(devname) + 1;
748 
749 	ret = -EFAULT;
750 	if (copy_to_sockptr(optval, devname, len))
751 		goto out;
752 
753 zero:
754 	ret = -EFAULT;
755 	if (copy_to_sockptr(optlen, &len, sizeof(int)))
756 		goto out;
757 
758 	ret = 0;
759 
760 out:
761 #endif
762 
763 	return ret;
764 }
765 
sk_mc_loop(const struct sock * sk)766 bool sk_mc_loop(const struct sock *sk)
767 {
768 	if (dev_recursion_level())
769 		return false;
770 	if (!sk)
771 		return true;
772 	/* IPV6_ADDRFORM can change sk->sk_family under us. */
773 	switch (READ_ONCE(sk->sk_family)) {
774 	case AF_INET:
775 		return inet_test_bit(MC_LOOP, sk);
776 #if IS_ENABLED(CONFIG_IPV6)
777 	case AF_INET6:
778 		return inet6_test_bit(MC6_LOOP, sk);
779 #endif
780 	}
781 	WARN_ON_ONCE(1);
782 	return true;
783 }
784 EXPORT_SYMBOL(sk_mc_loop);
785 
sock_set_reuseaddr(struct sock * sk)786 void sock_set_reuseaddr(struct sock *sk)
787 {
788 	lock_sock(sk);
789 	sk->sk_reuse = SK_CAN_REUSE;
790 	release_sock(sk);
791 }
792 EXPORT_SYMBOL(sock_set_reuseaddr);
793 
sock_set_reuseport(struct sock * sk)794 void sock_set_reuseport(struct sock *sk)
795 {
796 	lock_sock(sk);
797 	sk->sk_reuseport = true;
798 	release_sock(sk);
799 }
800 EXPORT_SYMBOL(sock_set_reuseport);
801 
sock_no_linger(struct sock * sk)802 void sock_no_linger(struct sock *sk)
803 {
804 	lock_sock(sk);
805 	WRITE_ONCE(sk->sk_lingertime, 0);
806 	sock_set_flag(sk, SOCK_LINGER);
807 	release_sock(sk);
808 }
809 EXPORT_SYMBOL(sock_no_linger);
810 
sock_set_priority(struct sock * sk,u32 priority)811 void sock_set_priority(struct sock *sk, u32 priority)
812 {
813 	WRITE_ONCE(sk->sk_priority, priority);
814 }
815 EXPORT_SYMBOL(sock_set_priority);
816 
sock_set_sndtimeo(struct sock * sk,s64 secs)817 void sock_set_sndtimeo(struct sock *sk, s64 secs)
818 {
819 	lock_sock(sk);
820 	if (secs && secs < MAX_SCHEDULE_TIMEOUT / HZ - 1)
821 		WRITE_ONCE(sk->sk_sndtimeo, secs * HZ);
822 	else
823 		WRITE_ONCE(sk->sk_sndtimeo, MAX_SCHEDULE_TIMEOUT);
824 	release_sock(sk);
825 }
826 EXPORT_SYMBOL(sock_set_sndtimeo);
827 
__sock_set_timestamps(struct sock * sk,bool val,bool new,bool ns)828 static void __sock_set_timestamps(struct sock *sk, bool val, bool new, bool ns)
829 {
830 	sock_valbool_flag(sk, SOCK_RCVTSTAMP, val);
831 	sock_valbool_flag(sk, SOCK_RCVTSTAMPNS, val && ns);
832 	if (val)  {
833 		sock_valbool_flag(sk, SOCK_TSTAMP_NEW, new);
834 		sock_enable_timestamp(sk, SOCK_TIMESTAMP);
835 	}
836 }
837 
sock_enable_timestamps(struct sock * sk)838 void sock_enable_timestamps(struct sock *sk)
839 {
840 	lock_sock(sk);
841 	__sock_set_timestamps(sk, true, false, true);
842 	release_sock(sk);
843 }
844 EXPORT_SYMBOL(sock_enable_timestamps);
845 
sock_set_timestamp(struct sock * sk,int optname,bool valbool)846 void sock_set_timestamp(struct sock *sk, int optname, bool valbool)
847 {
848 	switch (optname) {
849 	case SO_TIMESTAMP_OLD:
850 		__sock_set_timestamps(sk, valbool, false, false);
851 		break;
852 	case SO_TIMESTAMP_NEW:
853 		__sock_set_timestamps(sk, valbool, true, false);
854 		break;
855 	case SO_TIMESTAMPNS_OLD:
856 		__sock_set_timestamps(sk, valbool, false, true);
857 		break;
858 	case SO_TIMESTAMPNS_NEW:
859 		__sock_set_timestamps(sk, valbool, true, true);
860 		break;
861 	}
862 }
863 
sock_timestamping_bind_phc(struct sock * sk,int phc_index)864 static int sock_timestamping_bind_phc(struct sock *sk, int phc_index)
865 {
866 	struct net *net = sock_net(sk);
867 	struct net_device *dev = NULL;
868 	bool match = false;
869 	int *vclock_index;
870 	int i, num;
871 
872 	if (sk->sk_bound_dev_if)
873 		dev = dev_get_by_index(net, sk->sk_bound_dev_if);
874 
875 	if (!dev) {
876 		pr_err("%s: sock not bind to device\n", __func__);
877 		return -EOPNOTSUPP;
878 	}
879 
880 	num = ethtool_get_phc_vclocks(dev, &vclock_index);
881 	dev_put(dev);
882 
883 	for (i = 0; i < num; i++) {
884 		if (*(vclock_index + i) == phc_index) {
885 			match = true;
886 			break;
887 		}
888 	}
889 
890 	if (num > 0)
891 		kfree(vclock_index);
892 
893 	if (!match)
894 		return -EINVAL;
895 
896 	WRITE_ONCE(sk->sk_bind_phc, phc_index);
897 
898 	return 0;
899 }
900 
sock_set_timestamping(struct sock * sk,int optname,struct so_timestamping timestamping)901 int sock_set_timestamping(struct sock *sk, int optname,
902 			  struct so_timestamping timestamping)
903 {
904 	int val = timestamping.flags;
905 	int ret;
906 
907 	if (val & ~SOF_TIMESTAMPING_MASK)
908 		return -EINVAL;
909 
910 	if (val & SOF_TIMESTAMPING_OPT_ID_TCP &&
911 	    !(val & SOF_TIMESTAMPING_OPT_ID))
912 		return -EINVAL;
913 
914 	if (val & SOF_TIMESTAMPING_OPT_ID &&
915 	    !(sk->sk_tsflags & SOF_TIMESTAMPING_OPT_ID)) {
916 		if (sk_is_tcp(sk)) {
917 			if ((1 << sk->sk_state) &
918 			    (TCPF_CLOSE | TCPF_LISTEN))
919 				return -EINVAL;
920 			if (val & SOF_TIMESTAMPING_OPT_ID_TCP)
921 				atomic_set(&sk->sk_tskey, tcp_sk(sk)->write_seq);
922 			else
923 				atomic_set(&sk->sk_tskey, tcp_sk(sk)->snd_una);
924 		} else {
925 			atomic_set(&sk->sk_tskey, 0);
926 		}
927 	}
928 
929 	if (val & SOF_TIMESTAMPING_OPT_STATS &&
930 	    !(val & SOF_TIMESTAMPING_OPT_TSONLY))
931 		return -EINVAL;
932 
933 	if (val & SOF_TIMESTAMPING_BIND_PHC) {
934 		ret = sock_timestamping_bind_phc(sk, timestamping.bind_phc);
935 		if (ret)
936 			return ret;
937 	}
938 
939 	WRITE_ONCE(sk->sk_tsflags, val);
940 	sock_valbool_flag(sk, SOCK_TSTAMP_NEW, optname == SO_TIMESTAMPING_NEW);
941 	sock_valbool_flag(sk, SOCK_TIMESTAMPING_ANY, !!(val & TSFLAGS_ANY));
942 
943 	if (val & SOF_TIMESTAMPING_RX_SOFTWARE)
944 		sock_enable_timestamp(sk,
945 				      SOCK_TIMESTAMPING_RX_SOFTWARE);
946 	else
947 		sock_disable_timestamp(sk,
948 				       (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE));
949 	return 0;
950 }
951 
952 #if defined(CONFIG_CGROUP_BPF)
bpf_skops_tx_timestamping(struct sock * sk,struct sk_buff * skb,int op)953 void bpf_skops_tx_timestamping(struct sock *sk, struct sk_buff *skb, int op)
954 {
955 	struct bpf_sock_ops_kern sock_ops;
956 
957 	memset(&sock_ops, 0, offsetof(struct bpf_sock_ops_kern, temp));
958 	sock_ops.op = op;
959 	sock_ops.is_fullsock = 1;
960 	sock_ops.sk = sk;
961 	bpf_skops_init_skb(&sock_ops, skb, 0);
962 	__cgroup_bpf_run_filter_sock_ops(sk, &sock_ops, CGROUP_SOCK_OPS);
963 }
964 #endif
965 
sock_set_keepalive(struct sock * sk)966 void sock_set_keepalive(struct sock *sk)
967 {
968 	lock_sock(sk);
969 	if (sk->sk_prot->keepalive)
970 		sk->sk_prot->keepalive(sk, true);
971 	sock_valbool_flag(sk, SOCK_KEEPOPEN, true);
972 	release_sock(sk);
973 }
974 EXPORT_SYMBOL(sock_set_keepalive);
975 
__sock_set_rcvbuf(struct sock * sk,int val)976 static void __sock_set_rcvbuf(struct sock *sk, int val)
977 {
978 	/* Ensure val * 2 fits into an int, to prevent max_t() from treating it
979 	 * as a negative value.
980 	 */
981 	val = min_t(int, val, INT_MAX / 2);
982 	sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
983 
984 	/* We double it on the way in to account for "struct sk_buff" etc.
985 	 * overhead.   Applications assume that the SO_RCVBUF setting they make
986 	 * will allow that much actual data to be received on that socket.
987 	 *
988 	 * Applications are unaware that "struct sk_buff" and other overheads
989 	 * allocate from the receive buffer during socket buffer allocation.
990 	 *
991 	 * And after considering the possible alternatives, returning the value
992 	 * we actually used in getsockopt is the most desirable behavior.
993 	 */
994 	WRITE_ONCE(sk->sk_rcvbuf, max_t(int, val * 2, SOCK_MIN_RCVBUF));
995 }
996 
sock_set_rcvbuf(struct sock * sk,int val)997 void sock_set_rcvbuf(struct sock *sk, int val)
998 {
999 	lock_sock(sk);
1000 	__sock_set_rcvbuf(sk, val);
1001 	release_sock(sk);
1002 }
1003 EXPORT_SYMBOL(sock_set_rcvbuf);
1004 
__sock_set_mark(struct sock * sk,u32 val)1005 static void __sock_set_mark(struct sock *sk, u32 val)
1006 {
1007 	if (val != sk->sk_mark) {
1008 		WRITE_ONCE(sk->sk_mark, val);
1009 		sk_dst_reset(sk);
1010 	}
1011 }
1012 
sock_set_mark(struct sock * sk,u32 val)1013 void sock_set_mark(struct sock *sk, u32 val)
1014 {
1015 	lock_sock(sk);
1016 	__sock_set_mark(sk, val);
1017 	release_sock(sk);
1018 }
1019 EXPORT_SYMBOL(sock_set_mark);
1020 
sock_release_reserved_memory(struct sock * sk,int bytes)1021 static void sock_release_reserved_memory(struct sock *sk, int bytes)
1022 {
1023 	/* Round down bytes to multiple of pages */
1024 	bytes = round_down(bytes, PAGE_SIZE);
1025 
1026 	WARN_ON(bytes > sk->sk_reserved_mem);
1027 	WRITE_ONCE(sk->sk_reserved_mem, sk->sk_reserved_mem - bytes);
1028 	sk_mem_reclaim(sk);
1029 }
1030 
sock_reserve_memory(struct sock * sk,int bytes)1031 static int sock_reserve_memory(struct sock *sk, int bytes)
1032 {
1033 	long allocated;
1034 	bool charged;
1035 	int pages;
1036 
1037 	if (!mem_cgroup_sockets_enabled || !sk->sk_memcg || !sk_has_account(sk))
1038 		return -EOPNOTSUPP;
1039 
1040 	if (!bytes)
1041 		return 0;
1042 
1043 	pages = sk_mem_pages(bytes);
1044 
1045 	/* pre-charge to memcg */
1046 	charged = mem_cgroup_charge_skmem(sk->sk_memcg, pages,
1047 					  GFP_KERNEL | __GFP_RETRY_MAYFAIL);
1048 	if (!charged)
1049 		return -ENOMEM;
1050 
1051 	/* pre-charge to forward_alloc */
1052 	sk_memory_allocated_add(sk, pages);
1053 	allocated = sk_memory_allocated(sk);
1054 	/* If the system goes into memory pressure with this
1055 	 * precharge, give up and return error.
1056 	 */
1057 	if (allocated > sk_prot_mem_limits(sk, 1)) {
1058 		sk_memory_allocated_sub(sk, pages);
1059 		mem_cgroup_uncharge_skmem(sk->sk_memcg, pages);
1060 		return -ENOMEM;
1061 	}
1062 	sk_forward_alloc_add(sk, pages << PAGE_SHIFT);
1063 
1064 	WRITE_ONCE(sk->sk_reserved_mem,
1065 		   sk->sk_reserved_mem + (pages << PAGE_SHIFT));
1066 
1067 	return 0;
1068 }
1069 
1070 #ifdef CONFIG_PAGE_POOL
1071 
1072 /* This is the number of tokens and frags that the user can SO_DEVMEM_DONTNEED
1073  * in 1 syscall. The limit exists to limit the amount of memory the kernel
1074  * allocates to copy these tokens, and to prevent looping over the frags for
1075  * too long.
1076  */
1077 #define MAX_DONTNEED_TOKENS 128
1078 #define MAX_DONTNEED_FRAGS 1024
1079 
1080 static noinline_for_stack int
sock_devmem_dontneed(struct sock * sk,sockptr_t optval,unsigned int optlen)1081 sock_devmem_dontneed(struct sock *sk, sockptr_t optval, unsigned int optlen)
1082 {
1083 	unsigned int num_tokens, i, j, k, netmem_num = 0;
1084 	struct dmabuf_token *tokens;
1085 	int ret = 0, num_frags = 0;
1086 	netmem_ref netmems[16];
1087 
1088 	if (!sk_is_tcp(sk))
1089 		return -EBADF;
1090 
1091 	if (optlen % sizeof(*tokens) ||
1092 	    optlen > sizeof(*tokens) * MAX_DONTNEED_TOKENS)
1093 		return -EINVAL;
1094 
1095 	num_tokens = optlen / sizeof(*tokens);
1096 	tokens = kvmalloc_array(num_tokens, sizeof(*tokens), GFP_KERNEL);
1097 	if (!tokens)
1098 		return -ENOMEM;
1099 
1100 	if (copy_from_sockptr(tokens, optval, optlen)) {
1101 		kvfree(tokens);
1102 		return -EFAULT;
1103 	}
1104 
1105 	xa_lock_bh(&sk->sk_user_frags);
1106 	for (i = 0; i < num_tokens; i++) {
1107 		for (j = 0; j < tokens[i].token_count; j++) {
1108 			if (++num_frags > MAX_DONTNEED_FRAGS)
1109 				goto frag_limit_reached;
1110 
1111 			netmem_ref netmem = (__force netmem_ref)__xa_erase(
1112 				&sk->sk_user_frags, tokens[i].token_start + j);
1113 
1114 			if (!netmem || WARN_ON_ONCE(!netmem_is_net_iov(netmem)))
1115 				continue;
1116 
1117 			netmems[netmem_num++] = netmem;
1118 			if (netmem_num == ARRAY_SIZE(netmems)) {
1119 				xa_unlock_bh(&sk->sk_user_frags);
1120 				for (k = 0; k < netmem_num; k++)
1121 					WARN_ON_ONCE(!napi_pp_put_page(netmems[k]));
1122 				netmem_num = 0;
1123 				xa_lock_bh(&sk->sk_user_frags);
1124 			}
1125 			ret++;
1126 		}
1127 	}
1128 
1129 frag_limit_reached:
1130 	xa_unlock_bh(&sk->sk_user_frags);
1131 	for (k = 0; k < netmem_num; k++)
1132 		WARN_ON_ONCE(!napi_pp_put_page(netmems[k]));
1133 
1134 	kvfree(tokens);
1135 	return ret;
1136 }
1137 #endif
1138 
sockopt_lock_sock(struct sock * sk)1139 void sockopt_lock_sock(struct sock *sk)
1140 {
1141 	/* When current->bpf_ctx is set, the setsockopt is called from
1142 	 * a bpf prog.  bpf has ensured the sk lock has been
1143 	 * acquired before calling setsockopt().
1144 	 */
1145 	if (has_current_bpf_ctx())
1146 		return;
1147 
1148 	lock_sock(sk);
1149 }
1150 EXPORT_SYMBOL(sockopt_lock_sock);
1151 
sockopt_release_sock(struct sock * sk)1152 void sockopt_release_sock(struct sock *sk)
1153 {
1154 	if (has_current_bpf_ctx())
1155 		return;
1156 
1157 	release_sock(sk);
1158 }
1159 EXPORT_SYMBOL(sockopt_release_sock);
1160 
sockopt_ns_capable(struct user_namespace * ns,int cap)1161 bool sockopt_ns_capable(struct user_namespace *ns, int cap)
1162 {
1163 	return has_current_bpf_ctx() || ns_capable(ns, cap);
1164 }
1165 EXPORT_SYMBOL(sockopt_ns_capable);
1166 
sockopt_capable(int cap)1167 bool sockopt_capable(int cap)
1168 {
1169 	return has_current_bpf_ctx() || capable(cap);
1170 }
1171 EXPORT_SYMBOL(sockopt_capable);
1172 
sockopt_validate_clockid(__kernel_clockid_t value)1173 static int sockopt_validate_clockid(__kernel_clockid_t value)
1174 {
1175 	switch (value) {
1176 	case CLOCK_REALTIME:
1177 	case CLOCK_MONOTONIC:
1178 	case CLOCK_TAI:
1179 		return 0;
1180 	}
1181 	return -EINVAL;
1182 }
1183 
1184 /*
1185  *	This is meant for all protocols to use and covers goings on
1186  *	at the socket level. Everything here is generic.
1187  */
1188 
sk_setsockopt(struct sock * sk,int level,int optname,sockptr_t optval,unsigned int optlen)1189 int sk_setsockopt(struct sock *sk, int level, int optname,
1190 		  sockptr_t optval, unsigned int optlen)
1191 {
1192 	struct so_timestamping timestamping;
1193 	struct socket *sock = sk->sk_socket;
1194 	struct sock_txtime sk_txtime;
1195 	int val;
1196 	int valbool;
1197 	struct linger ling;
1198 	int ret = 0;
1199 
1200 	/*
1201 	 *	Options without arguments
1202 	 */
1203 
1204 	if (optname == SO_BINDTODEVICE)
1205 		return sock_setbindtodevice(sk, optval, optlen);
1206 
1207 	if (optlen < sizeof(int))
1208 		return -EINVAL;
1209 
1210 	if (copy_from_sockptr(&val, optval, sizeof(val)))
1211 		return -EFAULT;
1212 
1213 	valbool = val ? 1 : 0;
1214 
1215 	/* handle options which do not require locking the socket. */
1216 	switch (optname) {
1217 	case SO_PRIORITY:
1218 		if (sk_set_prio_allowed(sk, val)) {
1219 			sock_set_priority(sk, val);
1220 			return 0;
1221 		}
1222 		return -EPERM;
1223 	case SO_PASSSEC:
1224 		assign_bit(SOCK_PASSSEC, &sock->flags, valbool);
1225 		return 0;
1226 	case SO_PASSCRED:
1227 		assign_bit(SOCK_PASSCRED, &sock->flags, valbool);
1228 		return 0;
1229 	case SO_PASSPIDFD:
1230 		assign_bit(SOCK_PASSPIDFD, &sock->flags, valbool);
1231 		return 0;
1232 	case SO_TYPE:
1233 	case SO_PROTOCOL:
1234 	case SO_DOMAIN:
1235 	case SO_ERROR:
1236 		return -ENOPROTOOPT;
1237 #ifdef CONFIG_NET_RX_BUSY_POLL
1238 	case SO_BUSY_POLL:
1239 		if (val < 0)
1240 			return -EINVAL;
1241 		WRITE_ONCE(sk->sk_ll_usec, val);
1242 		return 0;
1243 	case SO_PREFER_BUSY_POLL:
1244 		if (valbool && !sockopt_capable(CAP_NET_ADMIN))
1245 			return -EPERM;
1246 		WRITE_ONCE(sk->sk_prefer_busy_poll, valbool);
1247 		return 0;
1248 	case SO_BUSY_POLL_BUDGET:
1249 		if (val > READ_ONCE(sk->sk_busy_poll_budget) &&
1250 		    !sockopt_capable(CAP_NET_ADMIN))
1251 			return -EPERM;
1252 		if (val < 0 || val > U16_MAX)
1253 			return -EINVAL;
1254 		WRITE_ONCE(sk->sk_busy_poll_budget, val);
1255 		return 0;
1256 #endif
1257 	case SO_MAX_PACING_RATE:
1258 		{
1259 		unsigned long ulval = (val == ~0U) ? ~0UL : (unsigned int)val;
1260 		unsigned long pacing_rate;
1261 
1262 		if (sizeof(ulval) != sizeof(val) &&
1263 		    optlen >= sizeof(ulval) &&
1264 		    copy_from_sockptr(&ulval, optval, sizeof(ulval))) {
1265 			return -EFAULT;
1266 		}
1267 		if (ulval != ~0UL)
1268 			cmpxchg(&sk->sk_pacing_status,
1269 				SK_PACING_NONE,
1270 				SK_PACING_NEEDED);
1271 		/* Pairs with READ_ONCE() from sk_getsockopt() */
1272 		WRITE_ONCE(sk->sk_max_pacing_rate, ulval);
1273 		pacing_rate = READ_ONCE(sk->sk_pacing_rate);
1274 		if (ulval < pacing_rate)
1275 			WRITE_ONCE(sk->sk_pacing_rate, ulval);
1276 		return 0;
1277 		}
1278 	case SO_TXREHASH:
1279 		if (val < -1 || val > 1)
1280 			return -EINVAL;
1281 		if ((u8)val == SOCK_TXREHASH_DEFAULT)
1282 			val = READ_ONCE(sock_net(sk)->core.sysctl_txrehash);
1283 		/* Paired with READ_ONCE() in tcp_rtx_synack()
1284 		 * and sk_getsockopt().
1285 		 */
1286 		WRITE_ONCE(sk->sk_txrehash, (u8)val);
1287 		return 0;
1288 	case SO_PEEK_OFF:
1289 		{
1290 		int (*set_peek_off)(struct sock *sk, int val);
1291 
1292 		set_peek_off = READ_ONCE(sock->ops)->set_peek_off;
1293 		if (set_peek_off)
1294 			ret = set_peek_off(sk, val);
1295 		else
1296 			ret = -EOPNOTSUPP;
1297 		return ret;
1298 		}
1299 #ifdef CONFIG_PAGE_POOL
1300 	case SO_DEVMEM_DONTNEED:
1301 		return sock_devmem_dontneed(sk, optval, optlen);
1302 #endif
1303 	}
1304 
1305 	sockopt_lock_sock(sk);
1306 
1307 	switch (optname) {
1308 	case SO_DEBUG:
1309 		if (val && !sockopt_capable(CAP_NET_ADMIN))
1310 			ret = -EACCES;
1311 		else
1312 			sock_valbool_flag(sk, SOCK_DBG, valbool);
1313 		break;
1314 	case SO_REUSEADDR:
1315 		sk->sk_reuse = (valbool ? SK_CAN_REUSE : SK_NO_REUSE);
1316 		break;
1317 	case SO_REUSEPORT:
1318 		if (valbool && !sk_is_inet(sk))
1319 			ret = -EOPNOTSUPP;
1320 		else
1321 			sk->sk_reuseport = valbool;
1322 		break;
1323 	case SO_DONTROUTE:
1324 		sock_valbool_flag(sk, SOCK_LOCALROUTE, valbool);
1325 		sk_dst_reset(sk);
1326 		break;
1327 	case SO_BROADCAST:
1328 		sock_valbool_flag(sk, SOCK_BROADCAST, valbool);
1329 		break;
1330 	case SO_SNDBUF:
1331 		/* Don't error on this BSD doesn't and if you think
1332 		 * about it this is right. Otherwise apps have to
1333 		 * play 'guess the biggest size' games. RCVBUF/SNDBUF
1334 		 * are treated in BSD as hints
1335 		 */
1336 		val = min_t(u32, val, READ_ONCE(sysctl_wmem_max));
1337 set_sndbuf:
1338 		/* Ensure val * 2 fits into an int, to prevent max_t()
1339 		 * from treating it as a negative value.
1340 		 */
1341 		val = min_t(int, val, INT_MAX / 2);
1342 		sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
1343 		WRITE_ONCE(sk->sk_sndbuf,
1344 			   max_t(int, val * 2, SOCK_MIN_SNDBUF));
1345 		/* Wake up sending tasks if we upped the value. */
1346 		sk->sk_write_space(sk);
1347 		break;
1348 
1349 	case SO_SNDBUFFORCE:
1350 		if (!sockopt_capable(CAP_NET_ADMIN)) {
1351 			ret = -EPERM;
1352 			break;
1353 		}
1354 
1355 		/* No negative values (to prevent underflow, as val will be
1356 		 * multiplied by 2).
1357 		 */
1358 		if (val < 0)
1359 			val = 0;
1360 		goto set_sndbuf;
1361 
1362 	case SO_RCVBUF:
1363 		/* Don't error on this BSD doesn't and if you think
1364 		 * about it this is right. Otherwise apps have to
1365 		 * play 'guess the biggest size' games. RCVBUF/SNDBUF
1366 		 * are treated in BSD as hints
1367 		 */
1368 		__sock_set_rcvbuf(sk, min_t(u32, val, READ_ONCE(sysctl_rmem_max)));
1369 		break;
1370 
1371 	case SO_RCVBUFFORCE:
1372 		if (!sockopt_capable(CAP_NET_ADMIN)) {
1373 			ret = -EPERM;
1374 			break;
1375 		}
1376 
1377 		/* No negative values (to prevent underflow, as val will be
1378 		 * multiplied by 2).
1379 		 */
1380 		__sock_set_rcvbuf(sk, max(val, 0));
1381 		break;
1382 
1383 	case SO_KEEPALIVE:
1384 		if (sk->sk_prot->keepalive)
1385 			sk->sk_prot->keepalive(sk, valbool);
1386 		sock_valbool_flag(sk, SOCK_KEEPOPEN, valbool);
1387 		break;
1388 
1389 	case SO_OOBINLINE:
1390 		sock_valbool_flag(sk, SOCK_URGINLINE, valbool);
1391 		break;
1392 
1393 	case SO_NO_CHECK:
1394 		sk->sk_no_check_tx = valbool;
1395 		break;
1396 
1397 	case SO_LINGER:
1398 		if (optlen < sizeof(ling)) {
1399 			ret = -EINVAL;	/* 1003.1g */
1400 			break;
1401 		}
1402 		if (copy_from_sockptr(&ling, optval, sizeof(ling))) {
1403 			ret = -EFAULT;
1404 			break;
1405 		}
1406 		if (!ling.l_onoff) {
1407 			sock_reset_flag(sk, SOCK_LINGER);
1408 		} else {
1409 			unsigned long t_sec = ling.l_linger;
1410 
1411 			if (t_sec >= MAX_SCHEDULE_TIMEOUT / HZ)
1412 				WRITE_ONCE(sk->sk_lingertime, MAX_SCHEDULE_TIMEOUT);
1413 			else
1414 				WRITE_ONCE(sk->sk_lingertime, t_sec * HZ);
1415 			sock_set_flag(sk, SOCK_LINGER);
1416 		}
1417 		break;
1418 
1419 	case SO_BSDCOMPAT:
1420 		break;
1421 
1422 	case SO_TIMESTAMP_OLD:
1423 	case SO_TIMESTAMP_NEW:
1424 	case SO_TIMESTAMPNS_OLD:
1425 	case SO_TIMESTAMPNS_NEW:
1426 		sock_set_timestamp(sk, optname, valbool);
1427 		break;
1428 
1429 	case SO_TIMESTAMPING_NEW:
1430 	case SO_TIMESTAMPING_OLD:
1431 		if (optlen == sizeof(timestamping)) {
1432 			if (copy_from_sockptr(&timestamping, optval,
1433 					      sizeof(timestamping))) {
1434 				ret = -EFAULT;
1435 				break;
1436 			}
1437 		} else {
1438 			memset(&timestamping, 0, sizeof(timestamping));
1439 			timestamping.flags = val;
1440 		}
1441 		ret = sock_set_timestamping(sk, optname, timestamping);
1442 		break;
1443 
1444 	case SO_RCVLOWAT:
1445 		{
1446 		int (*set_rcvlowat)(struct sock *sk, int val) = NULL;
1447 
1448 		if (val < 0)
1449 			val = INT_MAX;
1450 		if (sock)
1451 			set_rcvlowat = READ_ONCE(sock->ops)->set_rcvlowat;
1452 		if (set_rcvlowat)
1453 			ret = set_rcvlowat(sk, val);
1454 		else
1455 			WRITE_ONCE(sk->sk_rcvlowat, val ? : 1);
1456 		break;
1457 		}
1458 	case SO_RCVTIMEO_OLD:
1459 	case SO_RCVTIMEO_NEW:
1460 		ret = sock_set_timeout(&sk->sk_rcvtimeo, optval,
1461 				       optlen, optname == SO_RCVTIMEO_OLD);
1462 		break;
1463 
1464 	case SO_SNDTIMEO_OLD:
1465 	case SO_SNDTIMEO_NEW:
1466 		ret = sock_set_timeout(&sk->sk_sndtimeo, optval,
1467 				       optlen, optname == SO_SNDTIMEO_OLD);
1468 		break;
1469 
1470 	case SO_ATTACH_FILTER: {
1471 		struct sock_fprog fprog;
1472 
1473 		ret = copy_bpf_fprog_from_user(&fprog, optval, optlen);
1474 		if (!ret)
1475 			ret = sk_attach_filter(&fprog, sk);
1476 		break;
1477 	}
1478 	case SO_ATTACH_BPF:
1479 		ret = -EINVAL;
1480 		if (optlen == sizeof(u32)) {
1481 			u32 ufd;
1482 
1483 			ret = -EFAULT;
1484 			if (copy_from_sockptr(&ufd, optval, sizeof(ufd)))
1485 				break;
1486 
1487 			ret = sk_attach_bpf(ufd, sk);
1488 		}
1489 		break;
1490 
1491 	case SO_ATTACH_REUSEPORT_CBPF: {
1492 		struct sock_fprog fprog;
1493 
1494 		ret = copy_bpf_fprog_from_user(&fprog, optval, optlen);
1495 		if (!ret)
1496 			ret = sk_reuseport_attach_filter(&fprog, sk);
1497 		break;
1498 	}
1499 	case SO_ATTACH_REUSEPORT_EBPF:
1500 		ret = -EINVAL;
1501 		if (optlen == sizeof(u32)) {
1502 			u32 ufd;
1503 
1504 			ret = -EFAULT;
1505 			if (copy_from_sockptr(&ufd, optval, sizeof(ufd)))
1506 				break;
1507 
1508 			ret = sk_reuseport_attach_bpf(ufd, sk);
1509 		}
1510 		break;
1511 
1512 	case SO_DETACH_REUSEPORT_BPF:
1513 		ret = reuseport_detach_prog(sk);
1514 		break;
1515 
1516 	case SO_DETACH_FILTER:
1517 		ret = sk_detach_filter(sk);
1518 		break;
1519 
1520 	case SO_LOCK_FILTER:
1521 		if (sock_flag(sk, SOCK_FILTER_LOCKED) && !valbool)
1522 			ret = -EPERM;
1523 		else
1524 			sock_valbool_flag(sk, SOCK_FILTER_LOCKED, valbool);
1525 		break;
1526 
1527 	case SO_MARK:
1528 		if (!sockopt_ns_capable(sock_net(sk)->user_ns, CAP_NET_RAW) &&
1529 		    !sockopt_ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) {
1530 			ret = -EPERM;
1531 			break;
1532 		}
1533 
1534 		__sock_set_mark(sk, val);
1535 		break;
1536 	case SO_RCVMARK:
1537 		sock_valbool_flag(sk, SOCK_RCVMARK, valbool);
1538 		break;
1539 
1540 	case SO_RCVPRIORITY:
1541 		sock_valbool_flag(sk, SOCK_RCVPRIORITY, valbool);
1542 		break;
1543 
1544 	case SO_RXQ_OVFL:
1545 		sock_valbool_flag(sk, SOCK_RXQ_OVFL, valbool);
1546 		break;
1547 
1548 	case SO_WIFI_STATUS:
1549 		sock_valbool_flag(sk, SOCK_WIFI_STATUS, valbool);
1550 		break;
1551 
1552 	case SO_NOFCS:
1553 		sock_valbool_flag(sk, SOCK_NOFCS, valbool);
1554 		break;
1555 
1556 	case SO_SELECT_ERR_QUEUE:
1557 		sock_valbool_flag(sk, SOCK_SELECT_ERR_QUEUE, valbool);
1558 		break;
1559 
1560 
1561 	case SO_INCOMING_CPU:
1562 		reuseport_update_incoming_cpu(sk, val);
1563 		break;
1564 
1565 	case SO_CNX_ADVICE:
1566 		if (val == 1)
1567 			dst_negative_advice(sk);
1568 		break;
1569 
1570 	case SO_ZEROCOPY:
1571 		if (sk->sk_family == PF_INET || sk->sk_family == PF_INET6) {
1572 			if (!(sk_is_tcp(sk) ||
1573 			      (sk->sk_type == SOCK_DGRAM &&
1574 			       sk->sk_protocol == IPPROTO_UDP)))
1575 				ret = -EOPNOTSUPP;
1576 		} else if (sk->sk_family != PF_RDS) {
1577 			ret = -EOPNOTSUPP;
1578 		}
1579 		if (!ret) {
1580 			if (val < 0 || val > 1)
1581 				ret = -EINVAL;
1582 			else
1583 				sock_valbool_flag(sk, SOCK_ZEROCOPY, valbool);
1584 		}
1585 		break;
1586 
1587 	case SO_TXTIME:
1588 		if (optlen != sizeof(struct sock_txtime)) {
1589 			ret = -EINVAL;
1590 			break;
1591 		} else if (copy_from_sockptr(&sk_txtime, optval,
1592 			   sizeof(struct sock_txtime))) {
1593 			ret = -EFAULT;
1594 			break;
1595 		} else if (sk_txtime.flags & ~SOF_TXTIME_FLAGS_MASK) {
1596 			ret = -EINVAL;
1597 			break;
1598 		}
1599 		/* CLOCK_MONOTONIC is only used by sch_fq, and this packet
1600 		 * scheduler has enough safe guards.
1601 		 */
1602 		if (sk_txtime.clockid != CLOCK_MONOTONIC &&
1603 		    !sockopt_ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) {
1604 			ret = -EPERM;
1605 			break;
1606 		}
1607 
1608 		ret = sockopt_validate_clockid(sk_txtime.clockid);
1609 		if (ret)
1610 			break;
1611 
1612 		sock_valbool_flag(sk, SOCK_TXTIME, true);
1613 		sk->sk_clockid = sk_txtime.clockid;
1614 		sk->sk_txtime_deadline_mode =
1615 			!!(sk_txtime.flags & SOF_TXTIME_DEADLINE_MODE);
1616 		sk->sk_txtime_report_errors =
1617 			!!(sk_txtime.flags & SOF_TXTIME_REPORT_ERRORS);
1618 		break;
1619 
1620 	case SO_BINDTOIFINDEX:
1621 		ret = sock_bindtoindex_locked(sk, val);
1622 		break;
1623 
1624 	case SO_BUF_LOCK:
1625 		if (val & ~SOCK_BUF_LOCK_MASK) {
1626 			ret = -EINVAL;
1627 			break;
1628 		}
1629 		sk->sk_userlocks = val | (sk->sk_userlocks &
1630 					  ~SOCK_BUF_LOCK_MASK);
1631 		break;
1632 
1633 	case SO_RESERVE_MEM:
1634 	{
1635 		int delta;
1636 
1637 		if (val < 0) {
1638 			ret = -EINVAL;
1639 			break;
1640 		}
1641 
1642 		delta = val - sk->sk_reserved_mem;
1643 		if (delta < 0)
1644 			sock_release_reserved_memory(sk, -delta);
1645 		else
1646 			ret = sock_reserve_memory(sk, delta);
1647 		break;
1648 	}
1649 
1650 	default:
1651 		ret = -ENOPROTOOPT;
1652 		break;
1653 	}
1654 	sockopt_release_sock(sk);
1655 	return ret;
1656 }
1657 
sock_setsockopt(struct socket * sock,int level,int optname,sockptr_t optval,unsigned int optlen)1658 int sock_setsockopt(struct socket *sock, int level, int optname,
1659 		    sockptr_t optval, unsigned int optlen)
1660 {
1661 	return sk_setsockopt(sock->sk, level, optname,
1662 			     optval, optlen);
1663 }
1664 EXPORT_SYMBOL(sock_setsockopt);
1665 
sk_get_peer_cred(struct sock * sk)1666 static const struct cred *sk_get_peer_cred(struct sock *sk)
1667 {
1668 	const struct cred *cred;
1669 
1670 	spin_lock(&sk->sk_peer_lock);
1671 	cred = get_cred(sk->sk_peer_cred);
1672 	spin_unlock(&sk->sk_peer_lock);
1673 
1674 	return cred;
1675 }
1676 
cred_to_ucred(struct pid * pid,const struct cred * cred,struct ucred * ucred)1677 static void cred_to_ucred(struct pid *pid, const struct cred *cred,
1678 			  struct ucred *ucred)
1679 {
1680 	ucred->pid = pid_vnr(pid);
1681 	ucred->uid = ucred->gid = -1;
1682 	if (cred) {
1683 		struct user_namespace *current_ns = current_user_ns();
1684 
1685 		ucred->uid = from_kuid_munged(current_ns, cred->euid);
1686 		ucred->gid = from_kgid_munged(current_ns, cred->egid);
1687 	}
1688 }
1689 
groups_to_user(sockptr_t dst,const struct group_info * src)1690 static int groups_to_user(sockptr_t dst, const struct group_info *src)
1691 {
1692 	struct user_namespace *user_ns = current_user_ns();
1693 	int i;
1694 
1695 	for (i = 0; i < src->ngroups; i++) {
1696 		gid_t gid = from_kgid_munged(user_ns, src->gid[i]);
1697 
1698 		if (copy_to_sockptr_offset(dst, i * sizeof(gid), &gid, sizeof(gid)))
1699 			return -EFAULT;
1700 	}
1701 
1702 	return 0;
1703 }
1704 
sk_getsockopt(struct sock * sk,int level,int optname,sockptr_t optval,sockptr_t optlen)1705 int sk_getsockopt(struct sock *sk, int level, int optname,
1706 		  sockptr_t optval, sockptr_t optlen)
1707 {
1708 	struct socket *sock = sk->sk_socket;
1709 
1710 	union {
1711 		int val;
1712 		u64 val64;
1713 		unsigned long ulval;
1714 		struct linger ling;
1715 		struct old_timeval32 tm32;
1716 		struct __kernel_old_timeval tm;
1717 		struct  __kernel_sock_timeval stm;
1718 		struct sock_txtime txtime;
1719 		struct so_timestamping timestamping;
1720 	} v;
1721 
1722 	int lv = sizeof(int);
1723 	int len;
1724 
1725 	if (copy_from_sockptr(&len, optlen, sizeof(int)))
1726 		return -EFAULT;
1727 	if (len < 0)
1728 		return -EINVAL;
1729 
1730 	memset(&v, 0, sizeof(v));
1731 
1732 	switch (optname) {
1733 	case SO_DEBUG:
1734 		v.val = sock_flag(sk, SOCK_DBG);
1735 		break;
1736 
1737 	case SO_DONTROUTE:
1738 		v.val = sock_flag(sk, SOCK_LOCALROUTE);
1739 		break;
1740 
1741 	case SO_BROADCAST:
1742 		v.val = sock_flag(sk, SOCK_BROADCAST);
1743 		break;
1744 
1745 	case SO_SNDBUF:
1746 		v.val = READ_ONCE(sk->sk_sndbuf);
1747 		break;
1748 
1749 	case SO_RCVBUF:
1750 		v.val = READ_ONCE(sk->sk_rcvbuf);
1751 		break;
1752 
1753 	case SO_REUSEADDR:
1754 		v.val = sk->sk_reuse;
1755 		break;
1756 
1757 	case SO_REUSEPORT:
1758 		v.val = sk->sk_reuseport;
1759 		break;
1760 
1761 	case SO_KEEPALIVE:
1762 		v.val = sock_flag(sk, SOCK_KEEPOPEN);
1763 		break;
1764 
1765 	case SO_TYPE:
1766 		v.val = sk->sk_type;
1767 		break;
1768 
1769 	case SO_PROTOCOL:
1770 		v.val = sk->sk_protocol;
1771 		break;
1772 
1773 	case SO_DOMAIN:
1774 		v.val = sk->sk_family;
1775 		break;
1776 
1777 	case SO_ERROR:
1778 		v.val = -sock_error(sk);
1779 		if (v.val == 0)
1780 			v.val = xchg(&sk->sk_err_soft, 0);
1781 		break;
1782 
1783 	case SO_OOBINLINE:
1784 		v.val = sock_flag(sk, SOCK_URGINLINE);
1785 		break;
1786 
1787 	case SO_NO_CHECK:
1788 		v.val = sk->sk_no_check_tx;
1789 		break;
1790 
1791 	case SO_PRIORITY:
1792 		v.val = READ_ONCE(sk->sk_priority);
1793 		break;
1794 
1795 	case SO_LINGER:
1796 		lv		= sizeof(v.ling);
1797 		v.ling.l_onoff	= sock_flag(sk, SOCK_LINGER);
1798 		v.ling.l_linger	= READ_ONCE(sk->sk_lingertime) / HZ;
1799 		break;
1800 
1801 	case SO_BSDCOMPAT:
1802 		break;
1803 
1804 	case SO_TIMESTAMP_OLD:
1805 		v.val = sock_flag(sk, SOCK_RCVTSTAMP) &&
1806 				!sock_flag(sk, SOCK_TSTAMP_NEW) &&
1807 				!sock_flag(sk, SOCK_RCVTSTAMPNS);
1808 		break;
1809 
1810 	case SO_TIMESTAMPNS_OLD:
1811 		v.val = sock_flag(sk, SOCK_RCVTSTAMPNS) && !sock_flag(sk, SOCK_TSTAMP_NEW);
1812 		break;
1813 
1814 	case SO_TIMESTAMP_NEW:
1815 		v.val = sock_flag(sk, SOCK_RCVTSTAMP) && sock_flag(sk, SOCK_TSTAMP_NEW);
1816 		break;
1817 
1818 	case SO_TIMESTAMPNS_NEW:
1819 		v.val = sock_flag(sk, SOCK_RCVTSTAMPNS) && sock_flag(sk, SOCK_TSTAMP_NEW);
1820 		break;
1821 
1822 	case SO_TIMESTAMPING_OLD:
1823 	case SO_TIMESTAMPING_NEW:
1824 		lv = sizeof(v.timestamping);
1825 		/* For the later-added case SO_TIMESTAMPING_NEW: Be strict about only
1826 		 * returning the flags when they were set through the same option.
1827 		 * Don't change the beviour for the old case SO_TIMESTAMPING_OLD.
1828 		 */
1829 		if (optname == SO_TIMESTAMPING_OLD || sock_flag(sk, SOCK_TSTAMP_NEW)) {
1830 			v.timestamping.flags = READ_ONCE(sk->sk_tsflags);
1831 			v.timestamping.bind_phc = READ_ONCE(sk->sk_bind_phc);
1832 		}
1833 		break;
1834 
1835 	case SO_RCVTIMEO_OLD:
1836 	case SO_RCVTIMEO_NEW:
1837 		lv = sock_get_timeout(READ_ONCE(sk->sk_rcvtimeo), &v,
1838 				      SO_RCVTIMEO_OLD == optname);
1839 		break;
1840 
1841 	case SO_SNDTIMEO_OLD:
1842 	case SO_SNDTIMEO_NEW:
1843 		lv = sock_get_timeout(READ_ONCE(sk->sk_sndtimeo), &v,
1844 				      SO_SNDTIMEO_OLD == optname);
1845 		break;
1846 
1847 	case SO_RCVLOWAT:
1848 		v.val = READ_ONCE(sk->sk_rcvlowat);
1849 		break;
1850 
1851 	case SO_SNDLOWAT:
1852 		v.val = 1;
1853 		break;
1854 
1855 	case SO_PASSCRED:
1856 		v.val = !!test_bit(SOCK_PASSCRED, &sock->flags);
1857 		break;
1858 
1859 	case SO_PASSPIDFD:
1860 		v.val = !!test_bit(SOCK_PASSPIDFD, &sock->flags);
1861 		break;
1862 
1863 	case SO_PEERCRED:
1864 	{
1865 		struct ucred peercred;
1866 		if (len > sizeof(peercred))
1867 			len = sizeof(peercred);
1868 
1869 		spin_lock(&sk->sk_peer_lock);
1870 		cred_to_ucred(sk->sk_peer_pid, sk->sk_peer_cred, &peercred);
1871 		spin_unlock(&sk->sk_peer_lock);
1872 
1873 		if (copy_to_sockptr(optval, &peercred, len))
1874 			return -EFAULT;
1875 		goto lenout;
1876 	}
1877 
1878 	case SO_PEERPIDFD:
1879 	{
1880 		struct pid *peer_pid;
1881 		struct file *pidfd_file = NULL;
1882 		int pidfd;
1883 
1884 		if (len > sizeof(pidfd))
1885 			len = sizeof(pidfd);
1886 
1887 		spin_lock(&sk->sk_peer_lock);
1888 		peer_pid = get_pid(sk->sk_peer_pid);
1889 		spin_unlock(&sk->sk_peer_lock);
1890 
1891 		if (!peer_pid)
1892 			return -ENODATA;
1893 
1894 		pidfd = pidfd_prepare(peer_pid, 0, &pidfd_file);
1895 		put_pid(peer_pid);
1896 		if (pidfd < 0)
1897 			return pidfd;
1898 
1899 		if (copy_to_sockptr(optval, &pidfd, len) ||
1900 		    copy_to_sockptr(optlen, &len, sizeof(int))) {
1901 			put_unused_fd(pidfd);
1902 			fput(pidfd_file);
1903 
1904 			return -EFAULT;
1905 		}
1906 
1907 		fd_install(pidfd, pidfd_file);
1908 		return 0;
1909 	}
1910 
1911 	case SO_PEERGROUPS:
1912 	{
1913 		const struct cred *cred;
1914 		int ret, n;
1915 
1916 		cred = sk_get_peer_cred(sk);
1917 		if (!cred)
1918 			return -ENODATA;
1919 
1920 		n = cred->group_info->ngroups;
1921 		if (len < n * sizeof(gid_t)) {
1922 			len = n * sizeof(gid_t);
1923 			put_cred(cred);
1924 			return copy_to_sockptr(optlen, &len, sizeof(int)) ? -EFAULT : -ERANGE;
1925 		}
1926 		len = n * sizeof(gid_t);
1927 
1928 		ret = groups_to_user(optval, cred->group_info);
1929 		put_cred(cred);
1930 		if (ret)
1931 			return ret;
1932 		goto lenout;
1933 	}
1934 
1935 	case SO_PEERNAME:
1936 	{
1937 		struct sockaddr_storage address;
1938 
1939 		lv = READ_ONCE(sock->ops)->getname(sock, (struct sockaddr *)&address, 2);
1940 		if (lv < 0)
1941 			return -ENOTCONN;
1942 		if (lv < len)
1943 			return -EINVAL;
1944 		if (copy_to_sockptr(optval, &address, len))
1945 			return -EFAULT;
1946 		goto lenout;
1947 	}
1948 
1949 	/* Dubious BSD thing... Probably nobody even uses it, but
1950 	 * the UNIX standard wants it for whatever reason... -DaveM
1951 	 */
1952 	case SO_ACCEPTCONN:
1953 		v.val = sk->sk_state == TCP_LISTEN;
1954 		break;
1955 
1956 	case SO_PASSSEC:
1957 		v.val = !!test_bit(SOCK_PASSSEC, &sock->flags);
1958 		break;
1959 
1960 	case SO_PEERSEC:
1961 		return security_socket_getpeersec_stream(sock,
1962 							 optval, optlen, len);
1963 
1964 	case SO_MARK:
1965 		v.val = READ_ONCE(sk->sk_mark);
1966 		break;
1967 
1968 	case SO_RCVMARK:
1969 		v.val = sock_flag(sk, SOCK_RCVMARK);
1970 		break;
1971 
1972 	case SO_RCVPRIORITY:
1973 		v.val = sock_flag(sk, SOCK_RCVPRIORITY);
1974 		break;
1975 
1976 	case SO_RXQ_OVFL:
1977 		v.val = sock_flag(sk, SOCK_RXQ_OVFL);
1978 		break;
1979 
1980 	case SO_WIFI_STATUS:
1981 		v.val = sock_flag(sk, SOCK_WIFI_STATUS);
1982 		break;
1983 
1984 	case SO_PEEK_OFF:
1985 		if (!READ_ONCE(sock->ops)->set_peek_off)
1986 			return -EOPNOTSUPP;
1987 
1988 		v.val = READ_ONCE(sk->sk_peek_off);
1989 		break;
1990 	case SO_NOFCS:
1991 		v.val = sock_flag(sk, SOCK_NOFCS);
1992 		break;
1993 
1994 	case SO_BINDTODEVICE:
1995 		return sock_getbindtodevice(sk, optval, optlen, len);
1996 
1997 	case SO_GET_FILTER:
1998 		len = sk_get_filter(sk, optval, len);
1999 		if (len < 0)
2000 			return len;
2001 
2002 		goto lenout;
2003 
2004 	case SO_LOCK_FILTER:
2005 		v.val = sock_flag(sk, SOCK_FILTER_LOCKED);
2006 		break;
2007 
2008 	case SO_BPF_EXTENSIONS:
2009 		v.val = bpf_tell_extensions();
2010 		break;
2011 
2012 	case SO_SELECT_ERR_QUEUE:
2013 		v.val = sock_flag(sk, SOCK_SELECT_ERR_QUEUE);
2014 		break;
2015 
2016 #ifdef CONFIG_NET_RX_BUSY_POLL
2017 	case SO_BUSY_POLL:
2018 		v.val = READ_ONCE(sk->sk_ll_usec);
2019 		break;
2020 	case SO_PREFER_BUSY_POLL:
2021 		v.val = READ_ONCE(sk->sk_prefer_busy_poll);
2022 		break;
2023 #endif
2024 
2025 	case SO_MAX_PACING_RATE:
2026 		/* The READ_ONCE() pair with the WRITE_ONCE() in sk_setsockopt() */
2027 		if (sizeof(v.ulval) != sizeof(v.val) && len >= sizeof(v.ulval)) {
2028 			lv = sizeof(v.ulval);
2029 			v.ulval = READ_ONCE(sk->sk_max_pacing_rate);
2030 		} else {
2031 			/* 32bit version */
2032 			v.val = min_t(unsigned long, ~0U,
2033 				      READ_ONCE(sk->sk_max_pacing_rate));
2034 		}
2035 		break;
2036 
2037 	case SO_INCOMING_CPU:
2038 		v.val = READ_ONCE(sk->sk_incoming_cpu);
2039 		break;
2040 
2041 	case SO_MEMINFO:
2042 	{
2043 		u32 meminfo[SK_MEMINFO_VARS];
2044 
2045 		sk_get_meminfo(sk, meminfo);
2046 
2047 		len = min_t(unsigned int, len, sizeof(meminfo));
2048 		if (copy_to_sockptr(optval, &meminfo, len))
2049 			return -EFAULT;
2050 
2051 		goto lenout;
2052 	}
2053 
2054 #ifdef CONFIG_NET_RX_BUSY_POLL
2055 	case SO_INCOMING_NAPI_ID:
2056 		v.val = READ_ONCE(sk->sk_napi_id);
2057 
2058 		/* aggregate non-NAPI IDs down to 0 */
2059 		if (!napi_id_valid(v.val))
2060 			v.val = 0;
2061 
2062 		break;
2063 #endif
2064 
2065 	case SO_COOKIE:
2066 		lv = sizeof(u64);
2067 		if (len < lv)
2068 			return -EINVAL;
2069 		v.val64 = sock_gen_cookie(sk);
2070 		break;
2071 
2072 	case SO_ZEROCOPY:
2073 		v.val = sock_flag(sk, SOCK_ZEROCOPY);
2074 		break;
2075 
2076 	case SO_TXTIME:
2077 		lv = sizeof(v.txtime);
2078 		v.txtime.clockid = sk->sk_clockid;
2079 		v.txtime.flags |= sk->sk_txtime_deadline_mode ?
2080 				  SOF_TXTIME_DEADLINE_MODE : 0;
2081 		v.txtime.flags |= sk->sk_txtime_report_errors ?
2082 				  SOF_TXTIME_REPORT_ERRORS : 0;
2083 		break;
2084 
2085 	case SO_BINDTOIFINDEX:
2086 		v.val = READ_ONCE(sk->sk_bound_dev_if);
2087 		break;
2088 
2089 	case SO_NETNS_COOKIE:
2090 		lv = sizeof(u64);
2091 		if (len != lv)
2092 			return -EINVAL;
2093 		v.val64 = sock_net(sk)->net_cookie;
2094 		break;
2095 
2096 	case SO_BUF_LOCK:
2097 		v.val = sk->sk_userlocks & SOCK_BUF_LOCK_MASK;
2098 		break;
2099 
2100 	case SO_RESERVE_MEM:
2101 		v.val = READ_ONCE(sk->sk_reserved_mem);
2102 		break;
2103 
2104 	case SO_TXREHASH:
2105 		/* Paired with WRITE_ONCE() in sk_setsockopt() */
2106 		v.val = READ_ONCE(sk->sk_txrehash);
2107 		break;
2108 
2109 	default:
2110 		/* We implement the SO_SNDLOWAT etc to not be settable
2111 		 * (1003.1g 7).
2112 		 */
2113 		return -ENOPROTOOPT;
2114 	}
2115 
2116 	if (len > lv)
2117 		len = lv;
2118 	if (copy_to_sockptr(optval, &v, len))
2119 		return -EFAULT;
2120 lenout:
2121 	if (copy_to_sockptr(optlen, &len, sizeof(int)))
2122 		return -EFAULT;
2123 	return 0;
2124 }
2125 
2126 /*
2127  * Initialize an sk_lock.
2128  *
2129  * (We also register the sk_lock with the lock validator.)
2130  */
sock_lock_init(struct sock * sk)2131 static inline void sock_lock_init(struct sock *sk)
2132 {
2133 	sk_owner_clear(sk);
2134 
2135 	if (sk->sk_kern_sock)
2136 		sock_lock_init_class_and_name(
2137 			sk,
2138 			af_family_kern_slock_key_strings[sk->sk_family],
2139 			af_family_kern_slock_keys + sk->sk_family,
2140 			af_family_kern_key_strings[sk->sk_family],
2141 			af_family_kern_keys + sk->sk_family);
2142 	else
2143 		sock_lock_init_class_and_name(
2144 			sk,
2145 			af_family_slock_key_strings[sk->sk_family],
2146 			af_family_slock_keys + sk->sk_family,
2147 			af_family_key_strings[sk->sk_family],
2148 			af_family_keys + sk->sk_family);
2149 }
2150 
2151 /*
2152  * Copy all fields from osk to nsk but nsk->sk_refcnt must not change yet,
2153  * even temporarily, because of RCU lookups. sk_node should also be left as is.
2154  * We must not copy fields between sk_dontcopy_begin and sk_dontcopy_end
2155  */
sock_copy(struct sock * nsk,const struct sock * osk)2156 static void sock_copy(struct sock *nsk, const struct sock *osk)
2157 {
2158 	const struct proto *prot = READ_ONCE(osk->sk_prot);
2159 #ifdef CONFIG_SECURITY_NETWORK
2160 	void *sptr = nsk->sk_security;
2161 #endif
2162 
2163 	/* If we move sk_tx_queue_mapping out of the private section,
2164 	 * we must check if sk_tx_queue_clear() is called after
2165 	 * sock_copy() in sk_clone_lock().
2166 	 */
2167 	BUILD_BUG_ON(offsetof(struct sock, sk_tx_queue_mapping) <
2168 		     offsetof(struct sock, sk_dontcopy_begin) ||
2169 		     offsetof(struct sock, sk_tx_queue_mapping) >=
2170 		     offsetof(struct sock, sk_dontcopy_end));
2171 
2172 	memcpy(nsk, osk, offsetof(struct sock, sk_dontcopy_begin));
2173 
2174 	unsafe_memcpy(&nsk->sk_dontcopy_end, &osk->sk_dontcopy_end,
2175 		      prot->obj_size - offsetof(struct sock, sk_dontcopy_end),
2176 		      /* alloc is larger than struct, see sk_prot_alloc() */);
2177 
2178 #ifdef CONFIG_SECURITY_NETWORK
2179 	nsk->sk_security = sptr;
2180 	security_sk_clone(osk, nsk);
2181 #endif
2182 }
2183 
sk_prot_alloc(struct proto * prot,gfp_t priority,int family)2184 static struct sock *sk_prot_alloc(struct proto *prot, gfp_t priority,
2185 		int family)
2186 {
2187 	struct sock *sk;
2188 	struct kmem_cache *slab;
2189 
2190 	slab = prot->slab;
2191 	if (slab != NULL) {
2192 		sk = kmem_cache_alloc(slab, priority & ~__GFP_ZERO);
2193 		if (!sk)
2194 			return sk;
2195 		if (want_init_on_alloc(priority))
2196 			sk_prot_clear_nulls(sk, prot->obj_size);
2197 	} else
2198 		sk = kmalloc(prot->obj_size, priority);
2199 
2200 	if (sk != NULL) {
2201 		if (security_sk_alloc(sk, family, priority))
2202 			goto out_free;
2203 
2204 		if (!try_module_get(prot->owner))
2205 			goto out_free_sec;
2206 	}
2207 
2208 	return sk;
2209 
2210 out_free_sec:
2211 	security_sk_free(sk);
2212 out_free:
2213 	if (slab != NULL)
2214 		kmem_cache_free(slab, sk);
2215 	else
2216 		kfree(sk);
2217 	return NULL;
2218 }
2219 
sk_prot_free(struct proto * prot,struct sock * sk)2220 static void sk_prot_free(struct proto *prot, struct sock *sk)
2221 {
2222 	struct kmem_cache *slab;
2223 	struct module *owner;
2224 
2225 	owner = prot->owner;
2226 	slab = prot->slab;
2227 
2228 	cgroup_sk_free(&sk->sk_cgrp_data);
2229 	mem_cgroup_sk_free(sk);
2230 	security_sk_free(sk);
2231 
2232 	sk_owner_put(sk);
2233 
2234 	if (slab != NULL)
2235 		kmem_cache_free(slab, sk);
2236 	else
2237 		kfree(sk);
2238 	module_put(owner);
2239 }
2240 
2241 /**
2242  *	sk_alloc - All socket objects are allocated here
2243  *	@net: the applicable net namespace
2244  *	@family: protocol family
2245  *	@priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
2246  *	@prot: struct proto associated with this new sock instance
2247  *	@kern: is this to be a kernel socket?
2248  */
sk_alloc(struct net * net,int family,gfp_t priority,struct proto * prot,int kern)2249 struct sock *sk_alloc(struct net *net, int family, gfp_t priority,
2250 		      struct proto *prot, int kern)
2251 {
2252 	struct sock *sk;
2253 
2254 	sk = sk_prot_alloc(prot, priority | __GFP_ZERO, family);
2255 	if (sk) {
2256 		sk->sk_family = family;
2257 		/*
2258 		 * See comment in struct sock definition to understand
2259 		 * why we need sk_prot_creator -acme
2260 		 */
2261 		sk->sk_prot = sk->sk_prot_creator = prot;
2262 		sk->sk_kern_sock = kern;
2263 		sock_lock_init(sk);
2264 		sk->sk_net_refcnt = kern ? 0 : 1;
2265 		if (likely(sk->sk_net_refcnt)) {
2266 			get_net_track(net, &sk->ns_tracker, priority);
2267 			sock_inuse_add(net, 1);
2268 		} else {
2269 			net_passive_inc(net);
2270 			__netns_tracker_alloc(net, &sk->ns_tracker,
2271 					      false, priority);
2272 		}
2273 
2274 		sock_net_set(sk, net);
2275 		refcount_set(&sk->sk_wmem_alloc, 1);
2276 
2277 		mem_cgroup_sk_alloc(sk);
2278 		cgroup_sk_alloc(&sk->sk_cgrp_data);
2279 		sock_update_classid(&sk->sk_cgrp_data);
2280 		sock_update_netprioidx(&sk->sk_cgrp_data);
2281 		sk_tx_queue_clear(sk);
2282 	}
2283 
2284 	return sk;
2285 }
2286 EXPORT_SYMBOL(sk_alloc);
2287 
2288 /* Sockets having SOCK_RCU_FREE will call this function after one RCU
2289  * grace period. This is the case for UDP sockets and TCP listeners.
2290  */
__sk_destruct(struct rcu_head * head)2291 static void __sk_destruct(struct rcu_head *head)
2292 {
2293 	struct sock *sk = container_of(head, struct sock, sk_rcu);
2294 	struct net *net = sock_net(sk);
2295 	struct sk_filter *filter;
2296 
2297 	if (sk->sk_destruct)
2298 		sk->sk_destruct(sk);
2299 
2300 	filter = rcu_dereference_check(sk->sk_filter,
2301 				       refcount_read(&sk->sk_wmem_alloc) == 0);
2302 	if (filter) {
2303 		sk_filter_uncharge(sk, filter);
2304 		RCU_INIT_POINTER(sk->sk_filter, NULL);
2305 	}
2306 
2307 	sock_disable_timestamp(sk, SK_FLAGS_TIMESTAMP);
2308 
2309 #ifdef CONFIG_BPF_SYSCALL
2310 	bpf_sk_storage_free(sk);
2311 #endif
2312 
2313 	if (atomic_read(&sk->sk_omem_alloc))
2314 		pr_debug("%s: optmem leakage (%d bytes) detected\n",
2315 			 __func__, atomic_read(&sk->sk_omem_alloc));
2316 
2317 	if (sk->sk_frag.page) {
2318 		put_page(sk->sk_frag.page);
2319 		sk->sk_frag.page = NULL;
2320 	}
2321 
2322 	/* We do not need to acquire sk->sk_peer_lock, we are the last user. */
2323 	put_cred(sk->sk_peer_cred);
2324 	put_pid(sk->sk_peer_pid);
2325 
2326 	if (likely(sk->sk_net_refcnt)) {
2327 		put_net_track(net, &sk->ns_tracker);
2328 	} else {
2329 		__netns_tracker_free(net, &sk->ns_tracker, false);
2330 		net_passive_dec(net);
2331 	}
2332 	sk_prot_free(sk->sk_prot_creator, sk);
2333 }
2334 
sk_net_refcnt_upgrade(struct sock * sk)2335 void sk_net_refcnt_upgrade(struct sock *sk)
2336 {
2337 	struct net *net = sock_net(sk);
2338 
2339 	WARN_ON_ONCE(sk->sk_net_refcnt);
2340 	__netns_tracker_free(net, &sk->ns_tracker, false);
2341 	net_passive_dec(net);
2342 	sk->sk_net_refcnt = 1;
2343 	get_net_track(net, &sk->ns_tracker, GFP_KERNEL);
2344 	sock_inuse_add(net, 1);
2345 }
2346 EXPORT_SYMBOL_GPL(sk_net_refcnt_upgrade);
2347 
sk_destruct(struct sock * sk)2348 void sk_destruct(struct sock *sk)
2349 {
2350 	bool use_call_rcu = sock_flag(sk, SOCK_RCU_FREE);
2351 
2352 	if (rcu_access_pointer(sk->sk_reuseport_cb)) {
2353 		reuseport_detach_sock(sk);
2354 		use_call_rcu = true;
2355 	}
2356 
2357 	if (use_call_rcu)
2358 		call_rcu(&sk->sk_rcu, __sk_destruct);
2359 	else
2360 		__sk_destruct(&sk->sk_rcu);
2361 }
2362 
__sk_free(struct sock * sk)2363 static void __sk_free(struct sock *sk)
2364 {
2365 	if (likely(sk->sk_net_refcnt))
2366 		sock_inuse_add(sock_net(sk), -1);
2367 
2368 	if (unlikely(sk->sk_net_refcnt && sock_diag_has_destroy_listeners(sk)))
2369 		sock_diag_broadcast_destroy(sk);
2370 	else
2371 		sk_destruct(sk);
2372 }
2373 
sk_free(struct sock * sk)2374 void sk_free(struct sock *sk)
2375 {
2376 	/*
2377 	 * We subtract one from sk_wmem_alloc and can know if
2378 	 * some packets are still in some tx queue.
2379 	 * If not null, sock_wfree() will call __sk_free(sk) later
2380 	 */
2381 	if (refcount_dec_and_test(&sk->sk_wmem_alloc))
2382 		__sk_free(sk);
2383 }
2384 EXPORT_SYMBOL(sk_free);
2385 
sk_init_common(struct sock * sk)2386 static void sk_init_common(struct sock *sk)
2387 {
2388 	skb_queue_head_init(&sk->sk_receive_queue);
2389 	skb_queue_head_init(&sk->sk_write_queue);
2390 	skb_queue_head_init(&sk->sk_error_queue);
2391 
2392 	rwlock_init(&sk->sk_callback_lock);
2393 	lockdep_set_class_and_name(&sk->sk_receive_queue.lock,
2394 			af_rlock_keys + sk->sk_family,
2395 			af_family_rlock_key_strings[sk->sk_family]);
2396 	lockdep_set_class_and_name(&sk->sk_write_queue.lock,
2397 			af_wlock_keys + sk->sk_family,
2398 			af_family_wlock_key_strings[sk->sk_family]);
2399 	lockdep_set_class_and_name(&sk->sk_error_queue.lock,
2400 			af_elock_keys + sk->sk_family,
2401 			af_family_elock_key_strings[sk->sk_family]);
2402 	if (sk->sk_kern_sock)
2403 		lockdep_set_class_and_name(&sk->sk_callback_lock,
2404 			af_kern_callback_keys + sk->sk_family,
2405 			af_family_kern_clock_key_strings[sk->sk_family]);
2406 	else
2407 		lockdep_set_class_and_name(&sk->sk_callback_lock,
2408 			af_callback_keys + sk->sk_family,
2409 			af_family_clock_key_strings[sk->sk_family]);
2410 }
2411 
2412 /**
2413  *	sk_clone_lock - clone a socket, and lock its clone
2414  *	@sk: the socket to clone
2415  *	@priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
2416  *
2417  *	Caller must unlock socket even in error path (bh_unlock_sock(newsk))
2418  */
sk_clone_lock(const struct sock * sk,const gfp_t priority)2419 struct sock *sk_clone_lock(const struct sock *sk, const gfp_t priority)
2420 {
2421 	struct proto *prot = READ_ONCE(sk->sk_prot);
2422 	struct sk_filter *filter;
2423 	bool is_charged = true;
2424 	struct sock *newsk;
2425 
2426 	newsk = sk_prot_alloc(prot, priority, sk->sk_family);
2427 	if (!newsk)
2428 		goto out;
2429 
2430 	sock_copy(newsk, sk);
2431 
2432 	newsk->sk_prot_creator = prot;
2433 
2434 	/* SANITY */
2435 	if (likely(newsk->sk_net_refcnt)) {
2436 		get_net_track(sock_net(newsk), &newsk->ns_tracker, priority);
2437 		sock_inuse_add(sock_net(newsk), 1);
2438 	} else {
2439 		/* Kernel sockets are not elevating the struct net refcount.
2440 		 * Instead, use a tracker to more easily detect if a layer
2441 		 * is not properly dismantling its kernel sockets at netns
2442 		 * destroy time.
2443 		 */
2444 		net_passive_inc(sock_net(newsk));
2445 		__netns_tracker_alloc(sock_net(newsk), &newsk->ns_tracker,
2446 				      false, priority);
2447 	}
2448 	sk_node_init(&newsk->sk_node);
2449 	sock_lock_init(newsk);
2450 	bh_lock_sock(newsk);
2451 	newsk->sk_backlog.head	= newsk->sk_backlog.tail = NULL;
2452 	newsk->sk_backlog.len = 0;
2453 
2454 	atomic_set(&newsk->sk_rmem_alloc, 0);
2455 
2456 	/* sk_wmem_alloc set to one (see sk_free() and sock_wfree()) */
2457 	refcount_set(&newsk->sk_wmem_alloc, 1);
2458 
2459 	atomic_set(&newsk->sk_omem_alloc, 0);
2460 	sk_init_common(newsk);
2461 
2462 	newsk->sk_dst_cache	= NULL;
2463 	newsk->sk_dst_pending_confirm = 0;
2464 	newsk->sk_wmem_queued	= 0;
2465 	newsk->sk_forward_alloc = 0;
2466 	newsk->sk_reserved_mem  = 0;
2467 	atomic_set(&newsk->sk_drops, 0);
2468 	newsk->sk_send_head	= NULL;
2469 	newsk->sk_userlocks	= sk->sk_userlocks & ~SOCK_BINDPORT_LOCK;
2470 	atomic_set(&newsk->sk_zckey, 0);
2471 
2472 	sock_reset_flag(newsk, SOCK_DONE);
2473 
2474 	/* sk->sk_memcg will be populated at accept() time */
2475 	newsk->sk_memcg = NULL;
2476 
2477 	cgroup_sk_clone(&newsk->sk_cgrp_data);
2478 
2479 	rcu_read_lock();
2480 	filter = rcu_dereference(sk->sk_filter);
2481 	if (filter != NULL)
2482 		/* though it's an empty new sock, the charging may fail
2483 		 * if sysctl_optmem_max was changed between creation of
2484 		 * original socket and cloning
2485 		 */
2486 		is_charged = sk_filter_charge(newsk, filter);
2487 	RCU_INIT_POINTER(newsk->sk_filter, filter);
2488 	rcu_read_unlock();
2489 
2490 	if (unlikely(!is_charged || xfrm_sk_clone_policy(newsk, sk))) {
2491 		/* We need to make sure that we don't uncharge the new
2492 		 * socket if we couldn't charge it in the first place
2493 		 * as otherwise we uncharge the parent's filter.
2494 		 */
2495 		if (!is_charged)
2496 			RCU_INIT_POINTER(newsk->sk_filter, NULL);
2497 		sk_free_unlock_clone(newsk);
2498 		newsk = NULL;
2499 		goto out;
2500 	}
2501 	RCU_INIT_POINTER(newsk->sk_reuseport_cb, NULL);
2502 
2503 	if (bpf_sk_storage_clone(sk, newsk)) {
2504 		sk_free_unlock_clone(newsk);
2505 		newsk = NULL;
2506 		goto out;
2507 	}
2508 
2509 	/* Clear sk_user_data if parent had the pointer tagged
2510 	 * as not suitable for copying when cloning.
2511 	 */
2512 	if (sk_user_data_is_nocopy(newsk))
2513 		newsk->sk_user_data = NULL;
2514 
2515 	newsk->sk_err	   = 0;
2516 	newsk->sk_err_soft = 0;
2517 	newsk->sk_priority = 0;
2518 	newsk->sk_incoming_cpu = raw_smp_processor_id();
2519 
2520 	/* Before updating sk_refcnt, we must commit prior changes to memory
2521 	 * (Documentation/RCU/rculist_nulls.rst for details)
2522 	 */
2523 	smp_wmb();
2524 	refcount_set(&newsk->sk_refcnt, 2);
2525 
2526 	sk_set_socket(newsk, NULL);
2527 	sk_tx_queue_clear(newsk);
2528 	RCU_INIT_POINTER(newsk->sk_wq, NULL);
2529 
2530 	if (newsk->sk_prot->sockets_allocated)
2531 		sk_sockets_allocated_inc(newsk);
2532 
2533 	if (sock_needs_netstamp(sk) && newsk->sk_flags & SK_FLAGS_TIMESTAMP)
2534 		net_enable_timestamp();
2535 out:
2536 	return newsk;
2537 }
2538 EXPORT_SYMBOL_GPL(sk_clone_lock);
2539 
sk_free_unlock_clone(struct sock * sk)2540 void sk_free_unlock_clone(struct sock *sk)
2541 {
2542 	/* It is still raw copy of parent, so invalidate
2543 	 * destructor and make plain sk_free() */
2544 	sk->sk_destruct = NULL;
2545 	bh_unlock_sock(sk);
2546 	sk_free(sk);
2547 }
2548 EXPORT_SYMBOL_GPL(sk_free_unlock_clone);
2549 
sk_dst_gso_max_size(struct sock * sk,struct dst_entry * dst)2550 static u32 sk_dst_gso_max_size(struct sock *sk, struct dst_entry *dst)
2551 {
2552 	bool is_ipv6 = false;
2553 	u32 max_size;
2554 
2555 #if IS_ENABLED(CONFIG_IPV6)
2556 	is_ipv6 = (sk->sk_family == AF_INET6 &&
2557 		   !ipv6_addr_v4mapped(&sk->sk_v6_rcv_saddr));
2558 #endif
2559 	/* pairs with the WRITE_ONCE() in netif_set_gso(_ipv4)_max_size() */
2560 	max_size = is_ipv6 ? READ_ONCE(dst->dev->gso_max_size) :
2561 			READ_ONCE(dst->dev->gso_ipv4_max_size);
2562 	if (max_size > GSO_LEGACY_MAX_SIZE && !sk_is_tcp(sk))
2563 		max_size = GSO_LEGACY_MAX_SIZE;
2564 
2565 	return max_size - (MAX_TCP_HEADER + 1);
2566 }
2567 
sk_setup_caps(struct sock * sk,struct dst_entry * dst)2568 void sk_setup_caps(struct sock *sk, struct dst_entry *dst)
2569 {
2570 	u32 max_segs = 1;
2571 
2572 	sk->sk_route_caps = dst->dev->features;
2573 	if (sk_is_tcp(sk)) {
2574 		struct inet_connection_sock *icsk = inet_csk(sk);
2575 
2576 		sk->sk_route_caps |= NETIF_F_GSO;
2577 		icsk->icsk_ack.dst_quick_ack = dst_metric(dst, RTAX_QUICKACK);
2578 	}
2579 	if (sk->sk_route_caps & NETIF_F_GSO)
2580 		sk->sk_route_caps |= NETIF_F_GSO_SOFTWARE;
2581 	if (unlikely(sk->sk_gso_disabled))
2582 		sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
2583 	if (sk_can_gso(sk)) {
2584 		if (dst->header_len && !xfrm_dst_offload_ok(dst)) {
2585 			sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
2586 		} else {
2587 			sk->sk_route_caps |= NETIF_F_SG | NETIF_F_HW_CSUM;
2588 			sk->sk_gso_max_size = sk_dst_gso_max_size(sk, dst);
2589 			/* pairs with the WRITE_ONCE() in netif_set_gso_max_segs() */
2590 			max_segs = max_t(u32, READ_ONCE(dst->dev->gso_max_segs), 1);
2591 		}
2592 	}
2593 	sk->sk_gso_max_segs = max_segs;
2594 	sk_dst_set(sk, dst);
2595 }
2596 EXPORT_SYMBOL_GPL(sk_setup_caps);
2597 
2598 /*
2599  *	Simple resource managers for sockets.
2600  */
2601 
2602 
2603 /*
2604  * Write buffer destructor automatically called from kfree_skb.
2605  */
sock_wfree(struct sk_buff * skb)2606 void sock_wfree(struct sk_buff *skb)
2607 {
2608 	struct sock *sk = skb->sk;
2609 	unsigned int len = skb->truesize;
2610 	bool free;
2611 
2612 	if (!sock_flag(sk, SOCK_USE_WRITE_QUEUE)) {
2613 		if (sock_flag(sk, SOCK_RCU_FREE) &&
2614 		    sk->sk_write_space == sock_def_write_space) {
2615 			rcu_read_lock();
2616 			free = refcount_sub_and_test(len, &sk->sk_wmem_alloc);
2617 			sock_def_write_space_wfree(sk);
2618 			rcu_read_unlock();
2619 			if (unlikely(free))
2620 				__sk_free(sk);
2621 			return;
2622 		}
2623 
2624 		/*
2625 		 * Keep a reference on sk_wmem_alloc, this will be released
2626 		 * after sk_write_space() call
2627 		 */
2628 		WARN_ON(refcount_sub_and_test(len - 1, &sk->sk_wmem_alloc));
2629 		sk->sk_write_space(sk);
2630 		len = 1;
2631 	}
2632 	/*
2633 	 * if sk_wmem_alloc reaches 0, we must finish what sk_free()
2634 	 * could not do because of in-flight packets
2635 	 */
2636 	if (refcount_sub_and_test(len, &sk->sk_wmem_alloc))
2637 		__sk_free(sk);
2638 }
2639 EXPORT_SYMBOL(sock_wfree);
2640 
2641 /* This variant of sock_wfree() is used by TCP,
2642  * since it sets SOCK_USE_WRITE_QUEUE.
2643  */
__sock_wfree(struct sk_buff * skb)2644 void __sock_wfree(struct sk_buff *skb)
2645 {
2646 	struct sock *sk = skb->sk;
2647 
2648 	if (refcount_sub_and_test(skb->truesize, &sk->sk_wmem_alloc))
2649 		__sk_free(sk);
2650 }
2651 
skb_set_owner_w(struct sk_buff * skb,struct sock * sk)2652 void skb_set_owner_w(struct sk_buff *skb, struct sock *sk)
2653 {
2654 	skb_orphan(skb);
2655 #ifdef CONFIG_INET
2656 	if (unlikely(!sk_fullsock(sk)))
2657 		return skb_set_owner_edemux(skb, sk);
2658 #endif
2659 	skb->sk = sk;
2660 	skb->destructor = sock_wfree;
2661 	skb_set_hash_from_sk(skb, sk);
2662 	/*
2663 	 * We used to take a refcount on sk, but following operation
2664 	 * is enough to guarantee sk_free() won't free this sock until
2665 	 * all in-flight packets are completed
2666 	 */
2667 	refcount_add(skb->truesize, &sk->sk_wmem_alloc);
2668 }
2669 EXPORT_SYMBOL(skb_set_owner_w);
2670 
can_skb_orphan_partial(const struct sk_buff * skb)2671 static bool can_skb_orphan_partial(const struct sk_buff *skb)
2672 {
2673 	/* Drivers depend on in-order delivery for crypto offload,
2674 	 * partial orphan breaks out-of-order-OK logic.
2675 	 */
2676 	if (skb_is_decrypted(skb))
2677 		return false;
2678 
2679 	return (skb->destructor == sock_wfree ||
2680 		(IS_ENABLED(CONFIG_INET) && skb->destructor == tcp_wfree));
2681 }
2682 
2683 /* This helper is used by netem, as it can hold packets in its
2684  * delay queue. We want to allow the owner socket to send more
2685  * packets, as if they were already TX completed by a typical driver.
2686  * But we also want to keep skb->sk set because some packet schedulers
2687  * rely on it (sch_fq for example).
2688  */
skb_orphan_partial(struct sk_buff * skb)2689 void skb_orphan_partial(struct sk_buff *skb)
2690 {
2691 	if (skb_is_tcp_pure_ack(skb))
2692 		return;
2693 
2694 	if (can_skb_orphan_partial(skb) && skb_set_owner_sk_safe(skb, skb->sk))
2695 		return;
2696 
2697 	skb_orphan(skb);
2698 }
2699 EXPORT_SYMBOL(skb_orphan_partial);
2700 
2701 /*
2702  * Read buffer destructor automatically called from kfree_skb.
2703  */
sock_rfree(struct sk_buff * skb)2704 void sock_rfree(struct sk_buff *skb)
2705 {
2706 	struct sock *sk = skb->sk;
2707 	unsigned int len = skb->truesize;
2708 
2709 	atomic_sub(len, &sk->sk_rmem_alloc);
2710 	sk_mem_uncharge(sk, len);
2711 }
2712 EXPORT_SYMBOL(sock_rfree);
2713 
2714 /*
2715  * Buffer destructor for skbs that are not used directly in read or write
2716  * path, e.g. for error handler skbs. Automatically called from kfree_skb.
2717  */
sock_efree(struct sk_buff * skb)2718 void sock_efree(struct sk_buff *skb)
2719 {
2720 	sock_put(skb->sk);
2721 }
2722 EXPORT_SYMBOL(sock_efree);
2723 
2724 /* Buffer destructor for prefetch/receive path where reference count may
2725  * not be held, e.g. for listen sockets.
2726  */
2727 #ifdef CONFIG_INET
sock_pfree(struct sk_buff * skb)2728 void sock_pfree(struct sk_buff *skb)
2729 {
2730 	struct sock *sk = skb->sk;
2731 
2732 	if (!sk_is_refcounted(sk))
2733 		return;
2734 
2735 	if (sk->sk_state == TCP_NEW_SYN_RECV && inet_reqsk(sk)->syncookie) {
2736 		inet_reqsk(sk)->rsk_listener = NULL;
2737 		reqsk_free(inet_reqsk(sk));
2738 		return;
2739 	}
2740 
2741 	sock_gen_put(sk);
2742 }
2743 EXPORT_SYMBOL(sock_pfree);
2744 #endif /* CONFIG_INET */
2745 
sock_i_uid(struct sock * sk)2746 kuid_t sock_i_uid(struct sock *sk)
2747 {
2748 	kuid_t uid;
2749 
2750 	read_lock_bh(&sk->sk_callback_lock);
2751 	uid = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_uid : GLOBAL_ROOT_UID;
2752 	read_unlock_bh(&sk->sk_callback_lock);
2753 	return uid;
2754 }
2755 EXPORT_SYMBOL(sock_i_uid);
2756 
__sock_i_ino(struct sock * sk)2757 unsigned long __sock_i_ino(struct sock *sk)
2758 {
2759 	unsigned long ino;
2760 
2761 	read_lock(&sk->sk_callback_lock);
2762 	ino = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_ino : 0;
2763 	read_unlock(&sk->sk_callback_lock);
2764 	return ino;
2765 }
2766 EXPORT_SYMBOL(__sock_i_ino);
2767 
sock_i_ino(struct sock * sk)2768 unsigned long sock_i_ino(struct sock *sk)
2769 {
2770 	unsigned long ino;
2771 
2772 	local_bh_disable();
2773 	ino = __sock_i_ino(sk);
2774 	local_bh_enable();
2775 	return ino;
2776 }
2777 EXPORT_SYMBOL(sock_i_ino);
2778 
2779 /*
2780  * Allocate a skb from the socket's send buffer.
2781  */
sock_wmalloc(struct sock * sk,unsigned long size,int force,gfp_t priority)2782 struct sk_buff *sock_wmalloc(struct sock *sk, unsigned long size, int force,
2783 			     gfp_t priority)
2784 {
2785 	if (force ||
2786 	    refcount_read(&sk->sk_wmem_alloc) < READ_ONCE(sk->sk_sndbuf)) {
2787 		struct sk_buff *skb = alloc_skb(size, priority);
2788 
2789 		if (skb) {
2790 			skb_set_owner_w(skb, sk);
2791 			return skb;
2792 		}
2793 	}
2794 	return NULL;
2795 }
2796 EXPORT_SYMBOL(sock_wmalloc);
2797 
sock_ofree(struct sk_buff * skb)2798 static void sock_ofree(struct sk_buff *skb)
2799 {
2800 	struct sock *sk = skb->sk;
2801 
2802 	atomic_sub(skb->truesize, &sk->sk_omem_alloc);
2803 }
2804 
sock_omalloc(struct sock * sk,unsigned long size,gfp_t priority)2805 struct sk_buff *sock_omalloc(struct sock *sk, unsigned long size,
2806 			     gfp_t priority)
2807 {
2808 	struct sk_buff *skb;
2809 
2810 	/* small safe race: SKB_TRUESIZE may differ from final skb->truesize */
2811 	if (atomic_read(&sk->sk_omem_alloc) + SKB_TRUESIZE(size) >
2812 	    READ_ONCE(sock_net(sk)->core.sysctl_optmem_max))
2813 		return NULL;
2814 
2815 	skb = alloc_skb(size, priority);
2816 	if (!skb)
2817 		return NULL;
2818 
2819 	atomic_add(skb->truesize, &sk->sk_omem_alloc);
2820 	skb->sk = sk;
2821 	skb->destructor = sock_ofree;
2822 	return skb;
2823 }
2824 
2825 /*
2826  * Allocate a memory block from the socket's option memory buffer.
2827  */
sock_kmalloc(struct sock * sk,int size,gfp_t priority)2828 void *sock_kmalloc(struct sock *sk, int size, gfp_t priority)
2829 {
2830 	int optmem_max = READ_ONCE(sock_net(sk)->core.sysctl_optmem_max);
2831 
2832 	if ((unsigned int)size <= optmem_max &&
2833 	    atomic_read(&sk->sk_omem_alloc) + size < optmem_max) {
2834 		void *mem;
2835 		/* First do the add, to avoid the race if kmalloc
2836 		 * might sleep.
2837 		 */
2838 		atomic_add(size, &sk->sk_omem_alloc);
2839 		mem = kmalloc(size, priority);
2840 		if (mem)
2841 			return mem;
2842 		atomic_sub(size, &sk->sk_omem_alloc);
2843 	}
2844 	return NULL;
2845 }
2846 EXPORT_SYMBOL(sock_kmalloc);
2847 
2848 /*
2849  * Duplicate the input "src" memory block using the socket's
2850  * option memory buffer.
2851  */
sock_kmemdup(struct sock * sk,const void * src,int size,gfp_t priority)2852 void *sock_kmemdup(struct sock *sk, const void *src,
2853 		   int size, gfp_t priority)
2854 {
2855 	void *mem;
2856 
2857 	mem = sock_kmalloc(sk, size, priority);
2858 	if (mem)
2859 		memcpy(mem, src, size);
2860 	return mem;
2861 }
2862 EXPORT_SYMBOL(sock_kmemdup);
2863 
2864 /* Free an option memory block. Note, we actually want the inline
2865  * here as this allows gcc to detect the nullify and fold away the
2866  * condition entirely.
2867  */
__sock_kfree_s(struct sock * sk,void * mem,int size,const bool nullify)2868 static inline void __sock_kfree_s(struct sock *sk, void *mem, int size,
2869 				  const bool nullify)
2870 {
2871 	if (WARN_ON_ONCE(!mem))
2872 		return;
2873 	if (nullify)
2874 		kfree_sensitive(mem);
2875 	else
2876 		kfree(mem);
2877 	atomic_sub(size, &sk->sk_omem_alloc);
2878 }
2879 
sock_kfree_s(struct sock * sk,void * mem,int size)2880 void sock_kfree_s(struct sock *sk, void *mem, int size)
2881 {
2882 	__sock_kfree_s(sk, mem, size, false);
2883 }
2884 EXPORT_SYMBOL(sock_kfree_s);
2885 
sock_kzfree_s(struct sock * sk,void * mem,int size)2886 void sock_kzfree_s(struct sock *sk, void *mem, int size)
2887 {
2888 	__sock_kfree_s(sk, mem, size, true);
2889 }
2890 EXPORT_SYMBOL(sock_kzfree_s);
2891 
2892 /* It is almost wait_for_tcp_memory minus release_sock/lock_sock.
2893    I think, these locks should be removed for datagram sockets.
2894  */
sock_wait_for_wmem(struct sock * sk,long timeo)2895 static long sock_wait_for_wmem(struct sock *sk, long timeo)
2896 {
2897 	DEFINE_WAIT(wait);
2898 
2899 	sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
2900 	for (;;) {
2901 		if (!timeo)
2902 			break;
2903 		if (signal_pending(current))
2904 			break;
2905 		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
2906 		prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
2907 		if (refcount_read(&sk->sk_wmem_alloc) < READ_ONCE(sk->sk_sndbuf))
2908 			break;
2909 		if (READ_ONCE(sk->sk_shutdown) & SEND_SHUTDOWN)
2910 			break;
2911 		if (READ_ONCE(sk->sk_err))
2912 			break;
2913 		timeo = schedule_timeout(timeo);
2914 	}
2915 	finish_wait(sk_sleep(sk), &wait);
2916 	return timeo;
2917 }
2918 
2919 
2920 /*
2921  *	Generic send/receive buffer handlers
2922  */
2923 
sock_alloc_send_pskb(struct sock * sk,unsigned long header_len,unsigned long data_len,int noblock,int * errcode,int max_page_order)2924 struct sk_buff *sock_alloc_send_pskb(struct sock *sk, unsigned long header_len,
2925 				     unsigned long data_len, int noblock,
2926 				     int *errcode, int max_page_order)
2927 {
2928 	struct sk_buff *skb;
2929 	long timeo;
2930 	int err;
2931 
2932 	timeo = sock_sndtimeo(sk, noblock);
2933 	for (;;) {
2934 		err = sock_error(sk);
2935 		if (err != 0)
2936 			goto failure;
2937 
2938 		err = -EPIPE;
2939 		if (READ_ONCE(sk->sk_shutdown) & SEND_SHUTDOWN)
2940 			goto failure;
2941 
2942 		if (sk_wmem_alloc_get(sk) < READ_ONCE(sk->sk_sndbuf))
2943 			break;
2944 
2945 		sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
2946 		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
2947 		err = -EAGAIN;
2948 		if (!timeo)
2949 			goto failure;
2950 		if (signal_pending(current))
2951 			goto interrupted;
2952 		timeo = sock_wait_for_wmem(sk, timeo);
2953 	}
2954 	skb = alloc_skb_with_frags(header_len, data_len, max_page_order,
2955 				   errcode, sk->sk_allocation);
2956 	if (skb)
2957 		skb_set_owner_w(skb, sk);
2958 	return skb;
2959 
2960 interrupted:
2961 	err = sock_intr_errno(timeo);
2962 failure:
2963 	*errcode = err;
2964 	return NULL;
2965 }
2966 EXPORT_SYMBOL(sock_alloc_send_pskb);
2967 
__sock_cmsg_send(struct sock * sk,struct cmsghdr * cmsg,struct sockcm_cookie * sockc)2968 int __sock_cmsg_send(struct sock *sk, struct cmsghdr *cmsg,
2969 		     struct sockcm_cookie *sockc)
2970 {
2971 	u32 tsflags;
2972 
2973 	BUILD_BUG_ON(SOF_TIMESTAMPING_LAST == (1 << 31));
2974 
2975 	switch (cmsg->cmsg_type) {
2976 	case SO_MARK:
2977 		if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_RAW) &&
2978 		    !ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
2979 			return -EPERM;
2980 		if (cmsg->cmsg_len != CMSG_LEN(sizeof(u32)))
2981 			return -EINVAL;
2982 		sockc->mark = *(u32 *)CMSG_DATA(cmsg);
2983 		break;
2984 	case SO_TIMESTAMPING_OLD:
2985 	case SO_TIMESTAMPING_NEW:
2986 		if (cmsg->cmsg_len != CMSG_LEN(sizeof(u32)))
2987 			return -EINVAL;
2988 
2989 		tsflags = *(u32 *)CMSG_DATA(cmsg);
2990 		if (tsflags & ~SOF_TIMESTAMPING_TX_RECORD_MASK)
2991 			return -EINVAL;
2992 
2993 		sockc->tsflags &= ~SOF_TIMESTAMPING_TX_RECORD_MASK;
2994 		sockc->tsflags |= tsflags;
2995 		break;
2996 	case SCM_TXTIME:
2997 		if (!sock_flag(sk, SOCK_TXTIME))
2998 			return -EINVAL;
2999 		if (cmsg->cmsg_len != CMSG_LEN(sizeof(u64)))
3000 			return -EINVAL;
3001 		sockc->transmit_time = get_unaligned((u64 *)CMSG_DATA(cmsg));
3002 		break;
3003 	case SCM_TS_OPT_ID:
3004 		if (sk_is_tcp(sk))
3005 			return -EINVAL;
3006 		tsflags = READ_ONCE(sk->sk_tsflags);
3007 		if (!(tsflags & SOF_TIMESTAMPING_OPT_ID))
3008 			return -EINVAL;
3009 		if (cmsg->cmsg_len != CMSG_LEN(sizeof(u32)))
3010 			return -EINVAL;
3011 		sockc->ts_opt_id = *(u32 *)CMSG_DATA(cmsg);
3012 		sockc->tsflags |= SOCKCM_FLAG_TS_OPT_ID;
3013 		break;
3014 	/* SCM_RIGHTS and SCM_CREDENTIALS are semantically in SOL_UNIX. */
3015 	case SCM_RIGHTS:
3016 	case SCM_CREDENTIALS:
3017 		break;
3018 	case SO_PRIORITY:
3019 		if (cmsg->cmsg_len != CMSG_LEN(sizeof(u32)))
3020 			return -EINVAL;
3021 		if (!sk_set_prio_allowed(sk, *(u32 *)CMSG_DATA(cmsg)))
3022 			return -EPERM;
3023 		sockc->priority = *(u32 *)CMSG_DATA(cmsg);
3024 		break;
3025 	default:
3026 		return -EINVAL;
3027 	}
3028 	return 0;
3029 }
3030 EXPORT_SYMBOL(__sock_cmsg_send);
3031 
sock_cmsg_send(struct sock * sk,struct msghdr * msg,struct sockcm_cookie * sockc)3032 int sock_cmsg_send(struct sock *sk, struct msghdr *msg,
3033 		   struct sockcm_cookie *sockc)
3034 {
3035 	struct cmsghdr *cmsg;
3036 	int ret;
3037 
3038 	for_each_cmsghdr(cmsg, msg) {
3039 		if (!CMSG_OK(msg, cmsg))
3040 			return -EINVAL;
3041 		if (cmsg->cmsg_level != SOL_SOCKET)
3042 			continue;
3043 		ret = __sock_cmsg_send(sk, cmsg, sockc);
3044 		if (ret)
3045 			return ret;
3046 	}
3047 	return 0;
3048 }
3049 EXPORT_SYMBOL(sock_cmsg_send);
3050 
sk_enter_memory_pressure(struct sock * sk)3051 static void sk_enter_memory_pressure(struct sock *sk)
3052 {
3053 	if (!sk->sk_prot->enter_memory_pressure)
3054 		return;
3055 
3056 	sk->sk_prot->enter_memory_pressure(sk);
3057 }
3058 
sk_leave_memory_pressure(struct sock * sk)3059 static void sk_leave_memory_pressure(struct sock *sk)
3060 {
3061 	if (sk->sk_prot->leave_memory_pressure) {
3062 		INDIRECT_CALL_INET_1(sk->sk_prot->leave_memory_pressure,
3063 				     tcp_leave_memory_pressure, sk);
3064 	} else {
3065 		unsigned long *memory_pressure = sk->sk_prot->memory_pressure;
3066 
3067 		if (memory_pressure && READ_ONCE(*memory_pressure))
3068 			WRITE_ONCE(*memory_pressure, 0);
3069 	}
3070 }
3071 
3072 DEFINE_STATIC_KEY_FALSE(net_high_order_alloc_disable_key);
3073 
3074 /**
3075  * skb_page_frag_refill - check that a page_frag contains enough room
3076  * @sz: minimum size of the fragment we want to get
3077  * @pfrag: pointer to page_frag
3078  * @gfp: priority for memory allocation
3079  *
3080  * Note: While this allocator tries to use high order pages, there is
3081  * no guarantee that allocations succeed. Therefore, @sz MUST be
3082  * less or equal than PAGE_SIZE.
3083  */
skb_page_frag_refill(unsigned int sz,struct page_frag * pfrag,gfp_t gfp)3084 bool skb_page_frag_refill(unsigned int sz, struct page_frag *pfrag, gfp_t gfp)
3085 {
3086 	if (pfrag->page) {
3087 		if (page_ref_count(pfrag->page) == 1) {
3088 			pfrag->offset = 0;
3089 			return true;
3090 		}
3091 		if (pfrag->offset + sz <= pfrag->size)
3092 			return true;
3093 		put_page(pfrag->page);
3094 	}
3095 
3096 	pfrag->offset = 0;
3097 	if (SKB_FRAG_PAGE_ORDER &&
3098 	    !static_branch_unlikely(&net_high_order_alloc_disable_key)) {
3099 		/* Avoid direct reclaim but allow kswapd to wake */
3100 		pfrag->page = alloc_pages((gfp & ~__GFP_DIRECT_RECLAIM) |
3101 					  __GFP_COMP | __GFP_NOWARN |
3102 					  __GFP_NORETRY,
3103 					  SKB_FRAG_PAGE_ORDER);
3104 		if (likely(pfrag->page)) {
3105 			pfrag->size = PAGE_SIZE << SKB_FRAG_PAGE_ORDER;
3106 			return true;
3107 		}
3108 	}
3109 	pfrag->page = alloc_page(gfp);
3110 	if (likely(pfrag->page)) {
3111 		pfrag->size = PAGE_SIZE;
3112 		return true;
3113 	}
3114 	return false;
3115 }
3116 EXPORT_SYMBOL(skb_page_frag_refill);
3117 
sk_page_frag_refill(struct sock * sk,struct page_frag * pfrag)3118 bool sk_page_frag_refill(struct sock *sk, struct page_frag *pfrag)
3119 {
3120 	if (likely(skb_page_frag_refill(32U, pfrag, sk->sk_allocation)))
3121 		return true;
3122 
3123 	sk_enter_memory_pressure(sk);
3124 	sk_stream_moderate_sndbuf(sk);
3125 	return false;
3126 }
3127 EXPORT_SYMBOL(sk_page_frag_refill);
3128 
__lock_sock(struct sock * sk)3129 void __lock_sock(struct sock *sk)
3130 	__releases(&sk->sk_lock.slock)
3131 	__acquires(&sk->sk_lock.slock)
3132 {
3133 	DEFINE_WAIT(wait);
3134 
3135 	for (;;) {
3136 		prepare_to_wait_exclusive(&sk->sk_lock.wq, &wait,
3137 					TASK_UNINTERRUPTIBLE);
3138 		spin_unlock_bh(&sk->sk_lock.slock);
3139 		schedule();
3140 		spin_lock_bh(&sk->sk_lock.slock);
3141 		if (!sock_owned_by_user(sk))
3142 			break;
3143 	}
3144 	finish_wait(&sk->sk_lock.wq, &wait);
3145 }
3146 
__release_sock(struct sock * sk)3147 void __release_sock(struct sock *sk)
3148 	__releases(&sk->sk_lock.slock)
3149 	__acquires(&sk->sk_lock.slock)
3150 {
3151 	struct sk_buff *skb, *next;
3152 
3153 	while ((skb = sk->sk_backlog.head) != NULL) {
3154 		sk->sk_backlog.head = sk->sk_backlog.tail = NULL;
3155 
3156 		spin_unlock_bh(&sk->sk_lock.slock);
3157 
3158 		do {
3159 			next = skb->next;
3160 			prefetch(next);
3161 			DEBUG_NET_WARN_ON_ONCE(skb_dst_is_noref(skb));
3162 			skb_mark_not_on_list(skb);
3163 			sk_backlog_rcv(sk, skb);
3164 
3165 			cond_resched();
3166 
3167 			skb = next;
3168 		} while (skb != NULL);
3169 
3170 		spin_lock_bh(&sk->sk_lock.slock);
3171 	}
3172 
3173 	/*
3174 	 * Doing the zeroing here guarantee we can not loop forever
3175 	 * while a wild producer attempts to flood us.
3176 	 */
3177 	sk->sk_backlog.len = 0;
3178 }
3179 
__sk_flush_backlog(struct sock * sk)3180 void __sk_flush_backlog(struct sock *sk)
3181 {
3182 	spin_lock_bh(&sk->sk_lock.slock);
3183 	__release_sock(sk);
3184 
3185 	if (sk->sk_prot->release_cb)
3186 		INDIRECT_CALL_INET_1(sk->sk_prot->release_cb,
3187 				     tcp_release_cb, sk);
3188 
3189 	spin_unlock_bh(&sk->sk_lock.slock);
3190 }
3191 EXPORT_SYMBOL_GPL(__sk_flush_backlog);
3192 
3193 /**
3194  * sk_wait_data - wait for data to arrive at sk_receive_queue
3195  * @sk:    sock to wait on
3196  * @timeo: for how long
3197  * @skb:   last skb seen on sk_receive_queue
3198  *
3199  * Now socket state including sk->sk_err is changed only under lock,
3200  * hence we may omit checks after joining wait queue.
3201  * We check receive queue before schedule() only as optimization;
3202  * it is very likely that release_sock() added new data.
3203  */
sk_wait_data(struct sock * sk,long * timeo,const struct sk_buff * skb)3204 int sk_wait_data(struct sock *sk, long *timeo, const struct sk_buff *skb)
3205 {
3206 	DEFINE_WAIT_FUNC(wait, woken_wake_function);
3207 	int rc;
3208 
3209 	add_wait_queue(sk_sleep(sk), &wait);
3210 	sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
3211 	rc = sk_wait_event(sk, timeo, skb_peek_tail(&sk->sk_receive_queue) != skb, &wait);
3212 	sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
3213 	remove_wait_queue(sk_sleep(sk), &wait);
3214 	return rc;
3215 }
3216 EXPORT_SYMBOL(sk_wait_data);
3217 
3218 /**
3219  *	__sk_mem_raise_allocated - increase memory_allocated
3220  *	@sk: socket
3221  *	@size: memory size to allocate
3222  *	@amt: pages to allocate
3223  *	@kind: allocation type
3224  *
3225  *	Similar to __sk_mem_schedule(), but does not update sk_forward_alloc.
3226  *
3227  *	Unlike the globally shared limits among the sockets under same protocol,
3228  *	consuming the budget of a memcg won't have direct effect on other ones.
3229  *	So be optimistic about memcg's tolerance, and leave the callers to decide
3230  *	whether or not to raise allocated through sk_under_memory_pressure() or
3231  *	its variants.
3232  */
__sk_mem_raise_allocated(struct sock * sk,int size,int amt,int kind)3233 int __sk_mem_raise_allocated(struct sock *sk, int size, int amt, int kind)
3234 {
3235 	struct mem_cgroup *memcg = mem_cgroup_sockets_enabled ? sk->sk_memcg : NULL;
3236 	struct proto *prot = sk->sk_prot;
3237 	bool charged = false;
3238 	long allocated;
3239 
3240 	sk_memory_allocated_add(sk, amt);
3241 	allocated = sk_memory_allocated(sk);
3242 
3243 	if (memcg) {
3244 		if (!mem_cgroup_charge_skmem(memcg, amt, gfp_memcg_charge()))
3245 			goto suppress_allocation;
3246 		charged = true;
3247 	}
3248 
3249 	/* Under limit. */
3250 	if (allocated <= sk_prot_mem_limits(sk, 0)) {
3251 		sk_leave_memory_pressure(sk);
3252 		return 1;
3253 	}
3254 
3255 	/* Under pressure. */
3256 	if (allocated > sk_prot_mem_limits(sk, 1))
3257 		sk_enter_memory_pressure(sk);
3258 
3259 	/* Over hard limit. */
3260 	if (allocated > sk_prot_mem_limits(sk, 2))
3261 		goto suppress_allocation;
3262 
3263 	/* Guarantee minimum buffer size under pressure (either global
3264 	 * or memcg) to make sure features described in RFC 7323 (TCP
3265 	 * Extensions for High Performance) work properly.
3266 	 *
3267 	 * This rule does NOT stand when exceeds global or memcg's hard
3268 	 * limit, or else a DoS attack can be taken place by spawning
3269 	 * lots of sockets whose usage are under minimum buffer size.
3270 	 */
3271 	if (kind == SK_MEM_RECV) {
3272 		if (atomic_read(&sk->sk_rmem_alloc) < sk_get_rmem0(sk, prot))
3273 			return 1;
3274 
3275 	} else { /* SK_MEM_SEND */
3276 		int wmem0 = sk_get_wmem0(sk, prot);
3277 
3278 		if (sk->sk_type == SOCK_STREAM) {
3279 			if (sk->sk_wmem_queued < wmem0)
3280 				return 1;
3281 		} else if (refcount_read(&sk->sk_wmem_alloc) < wmem0) {
3282 				return 1;
3283 		}
3284 	}
3285 
3286 	if (sk_has_memory_pressure(sk)) {
3287 		u64 alloc;
3288 
3289 		/* The following 'average' heuristic is within the
3290 		 * scope of global accounting, so it only makes
3291 		 * sense for global memory pressure.
3292 		 */
3293 		if (!sk_under_global_memory_pressure(sk))
3294 			return 1;
3295 
3296 		/* Try to be fair among all the sockets under global
3297 		 * pressure by allowing the ones that below average
3298 		 * usage to raise.
3299 		 */
3300 		alloc = sk_sockets_allocated_read_positive(sk);
3301 		if (sk_prot_mem_limits(sk, 2) > alloc *
3302 		    sk_mem_pages(sk->sk_wmem_queued +
3303 				 atomic_read(&sk->sk_rmem_alloc) +
3304 				 sk->sk_forward_alloc))
3305 			return 1;
3306 	}
3307 
3308 suppress_allocation:
3309 
3310 	if (kind == SK_MEM_SEND && sk->sk_type == SOCK_STREAM) {
3311 		sk_stream_moderate_sndbuf(sk);
3312 
3313 		/* Fail only if socket is _under_ its sndbuf.
3314 		 * In this case we cannot block, so that we have to fail.
3315 		 */
3316 		if (sk->sk_wmem_queued + size >= sk->sk_sndbuf) {
3317 			/* Force charge with __GFP_NOFAIL */
3318 			if (memcg && !charged) {
3319 				mem_cgroup_charge_skmem(memcg, amt,
3320 					gfp_memcg_charge() | __GFP_NOFAIL);
3321 			}
3322 			return 1;
3323 		}
3324 	}
3325 
3326 	if (kind == SK_MEM_SEND || (kind == SK_MEM_RECV && charged))
3327 		trace_sock_exceed_buf_limit(sk, prot, allocated, kind);
3328 
3329 	sk_memory_allocated_sub(sk, amt);
3330 
3331 	if (charged)
3332 		mem_cgroup_uncharge_skmem(memcg, amt);
3333 
3334 	return 0;
3335 }
3336 
3337 /**
3338  *	__sk_mem_schedule - increase sk_forward_alloc and memory_allocated
3339  *	@sk: socket
3340  *	@size: memory size to allocate
3341  *	@kind: allocation type
3342  *
3343  *	If kind is SK_MEM_SEND, it means wmem allocation. Otherwise it means
3344  *	rmem allocation. This function assumes that protocols which have
3345  *	memory_pressure use sk_wmem_queued as write buffer accounting.
3346  */
__sk_mem_schedule(struct sock * sk,int size,int kind)3347 int __sk_mem_schedule(struct sock *sk, int size, int kind)
3348 {
3349 	int ret, amt = sk_mem_pages(size);
3350 
3351 	sk_forward_alloc_add(sk, amt << PAGE_SHIFT);
3352 	ret = __sk_mem_raise_allocated(sk, size, amt, kind);
3353 	if (!ret)
3354 		sk_forward_alloc_add(sk, -(amt << PAGE_SHIFT));
3355 	return ret;
3356 }
3357 EXPORT_SYMBOL(__sk_mem_schedule);
3358 
3359 /**
3360  *	__sk_mem_reduce_allocated - reclaim memory_allocated
3361  *	@sk: socket
3362  *	@amount: number of quanta
3363  *
3364  *	Similar to __sk_mem_reclaim(), but does not update sk_forward_alloc
3365  */
__sk_mem_reduce_allocated(struct sock * sk,int amount)3366 void __sk_mem_reduce_allocated(struct sock *sk, int amount)
3367 {
3368 	sk_memory_allocated_sub(sk, amount);
3369 
3370 	if (mem_cgroup_sockets_enabled && sk->sk_memcg)
3371 		mem_cgroup_uncharge_skmem(sk->sk_memcg, amount);
3372 
3373 	if (sk_under_global_memory_pressure(sk) &&
3374 	    (sk_memory_allocated(sk) < sk_prot_mem_limits(sk, 0)))
3375 		sk_leave_memory_pressure(sk);
3376 }
3377 
3378 /**
3379  *	__sk_mem_reclaim - reclaim sk_forward_alloc and memory_allocated
3380  *	@sk: socket
3381  *	@amount: number of bytes (rounded down to a PAGE_SIZE multiple)
3382  */
__sk_mem_reclaim(struct sock * sk,int amount)3383 void __sk_mem_reclaim(struct sock *sk, int amount)
3384 {
3385 	amount >>= PAGE_SHIFT;
3386 	sk_forward_alloc_add(sk, -(amount << PAGE_SHIFT));
3387 	__sk_mem_reduce_allocated(sk, amount);
3388 }
3389 EXPORT_SYMBOL(__sk_mem_reclaim);
3390 
sk_set_peek_off(struct sock * sk,int val)3391 int sk_set_peek_off(struct sock *sk, int val)
3392 {
3393 	WRITE_ONCE(sk->sk_peek_off, val);
3394 	return 0;
3395 }
3396 EXPORT_SYMBOL_GPL(sk_set_peek_off);
3397 
3398 /*
3399  * Set of default routines for initialising struct proto_ops when
3400  * the protocol does not support a particular function. In certain
3401  * cases where it makes no sense for a protocol to have a "do nothing"
3402  * function, some default processing is provided.
3403  */
3404 
sock_no_bind(struct socket * sock,struct sockaddr * saddr,int len)3405 int sock_no_bind(struct socket *sock, struct sockaddr *saddr, int len)
3406 {
3407 	return -EOPNOTSUPP;
3408 }
3409 EXPORT_SYMBOL(sock_no_bind);
3410 
sock_no_connect(struct socket * sock,struct sockaddr * saddr,int len,int flags)3411 int sock_no_connect(struct socket *sock, struct sockaddr *saddr,
3412 		    int len, int flags)
3413 {
3414 	return -EOPNOTSUPP;
3415 }
3416 EXPORT_SYMBOL(sock_no_connect);
3417 
sock_no_socketpair(struct socket * sock1,struct socket * sock2)3418 int sock_no_socketpair(struct socket *sock1, struct socket *sock2)
3419 {
3420 	return -EOPNOTSUPP;
3421 }
3422 EXPORT_SYMBOL(sock_no_socketpair);
3423 
sock_no_accept(struct socket * sock,struct socket * newsock,struct proto_accept_arg * arg)3424 int sock_no_accept(struct socket *sock, struct socket *newsock,
3425 		   struct proto_accept_arg *arg)
3426 {
3427 	return -EOPNOTSUPP;
3428 }
3429 EXPORT_SYMBOL(sock_no_accept);
3430 
sock_no_getname(struct socket * sock,struct sockaddr * saddr,int peer)3431 int sock_no_getname(struct socket *sock, struct sockaddr *saddr,
3432 		    int peer)
3433 {
3434 	return -EOPNOTSUPP;
3435 }
3436 EXPORT_SYMBOL(sock_no_getname);
3437 
sock_no_ioctl(struct socket * sock,unsigned int cmd,unsigned long arg)3438 int sock_no_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
3439 {
3440 	return -EOPNOTSUPP;
3441 }
3442 EXPORT_SYMBOL(sock_no_ioctl);
3443 
sock_no_listen(struct socket * sock,int backlog)3444 int sock_no_listen(struct socket *sock, int backlog)
3445 {
3446 	return -EOPNOTSUPP;
3447 }
3448 EXPORT_SYMBOL(sock_no_listen);
3449 
sock_no_shutdown(struct socket * sock,int how)3450 int sock_no_shutdown(struct socket *sock, int how)
3451 {
3452 	return -EOPNOTSUPP;
3453 }
3454 EXPORT_SYMBOL(sock_no_shutdown);
3455 
sock_no_sendmsg(struct socket * sock,struct msghdr * m,size_t len)3456 int sock_no_sendmsg(struct socket *sock, struct msghdr *m, size_t len)
3457 {
3458 	return -EOPNOTSUPP;
3459 }
3460 EXPORT_SYMBOL(sock_no_sendmsg);
3461 
sock_no_sendmsg_locked(struct sock * sk,struct msghdr * m,size_t len)3462 int sock_no_sendmsg_locked(struct sock *sk, struct msghdr *m, size_t len)
3463 {
3464 	return -EOPNOTSUPP;
3465 }
3466 EXPORT_SYMBOL(sock_no_sendmsg_locked);
3467 
sock_no_recvmsg(struct socket * sock,struct msghdr * m,size_t len,int flags)3468 int sock_no_recvmsg(struct socket *sock, struct msghdr *m, size_t len,
3469 		    int flags)
3470 {
3471 	return -EOPNOTSUPP;
3472 }
3473 EXPORT_SYMBOL(sock_no_recvmsg);
3474 
sock_no_mmap(struct file * file,struct socket * sock,struct vm_area_struct * vma)3475 int sock_no_mmap(struct file *file, struct socket *sock, struct vm_area_struct *vma)
3476 {
3477 	/* Mirror missing mmap method error code */
3478 	return -ENODEV;
3479 }
3480 EXPORT_SYMBOL(sock_no_mmap);
3481 
3482 /*
3483  * When a file is received (via SCM_RIGHTS, etc), we must bump the
3484  * various sock-based usage counts.
3485  */
__receive_sock(struct file * file)3486 void __receive_sock(struct file *file)
3487 {
3488 	struct socket *sock;
3489 
3490 	sock = sock_from_file(file);
3491 	if (sock) {
3492 		sock_update_netprioidx(&sock->sk->sk_cgrp_data);
3493 		sock_update_classid(&sock->sk->sk_cgrp_data);
3494 	}
3495 }
3496 
3497 /*
3498  *	Default Socket Callbacks
3499  */
3500 
sock_def_wakeup(struct sock * sk)3501 static void sock_def_wakeup(struct sock *sk)
3502 {
3503 	struct socket_wq *wq;
3504 
3505 	rcu_read_lock();
3506 	wq = rcu_dereference(sk->sk_wq);
3507 	if (skwq_has_sleeper(wq))
3508 		wake_up_interruptible_all(&wq->wait);
3509 	rcu_read_unlock();
3510 }
3511 
sock_def_error_report(struct sock * sk)3512 static void sock_def_error_report(struct sock *sk)
3513 {
3514 	struct socket_wq *wq;
3515 
3516 	rcu_read_lock();
3517 	wq = rcu_dereference(sk->sk_wq);
3518 	if (skwq_has_sleeper(wq))
3519 		wake_up_interruptible_poll(&wq->wait, EPOLLERR);
3520 	sk_wake_async_rcu(sk, SOCK_WAKE_IO, POLL_ERR);
3521 	rcu_read_unlock();
3522 }
3523 
sock_def_readable(struct sock * sk)3524 void sock_def_readable(struct sock *sk)
3525 {
3526 	struct socket_wq *wq;
3527 
3528 	trace_sk_data_ready(sk);
3529 
3530 	rcu_read_lock();
3531 	wq = rcu_dereference(sk->sk_wq);
3532 	if (skwq_has_sleeper(wq))
3533 		wake_up_interruptible_sync_poll(&wq->wait, EPOLLIN | EPOLLPRI |
3534 						EPOLLRDNORM | EPOLLRDBAND);
3535 	sk_wake_async_rcu(sk, SOCK_WAKE_WAITD, POLL_IN);
3536 	rcu_read_unlock();
3537 }
3538 
sock_def_write_space(struct sock * sk)3539 static void sock_def_write_space(struct sock *sk)
3540 {
3541 	struct socket_wq *wq;
3542 
3543 	rcu_read_lock();
3544 
3545 	/* Do not wake up a writer until he can make "significant"
3546 	 * progress.  --DaveM
3547 	 */
3548 	if (sock_writeable(sk)) {
3549 		wq = rcu_dereference(sk->sk_wq);
3550 		if (skwq_has_sleeper(wq))
3551 			wake_up_interruptible_sync_poll(&wq->wait, EPOLLOUT |
3552 						EPOLLWRNORM | EPOLLWRBAND);
3553 
3554 		/* Should agree with poll, otherwise some programs break */
3555 		sk_wake_async_rcu(sk, SOCK_WAKE_SPACE, POLL_OUT);
3556 	}
3557 
3558 	rcu_read_unlock();
3559 }
3560 
3561 /* An optimised version of sock_def_write_space(), should only be called
3562  * for SOCK_RCU_FREE sockets under RCU read section and after putting
3563  * ->sk_wmem_alloc.
3564  */
sock_def_write_space_wfree(struct sock * sk)3565 static void sock_def_write_space_wfree(struct sock *sk)
3566 {
3567 	/* Do not wake up a writer until he can make "significant"
3568 	 * progress.  --DaveM
3569 	 */
3570 	if (sock_writeable(sk)) {
3571 		struct socket_wq *wq = rcu_dereference(sk->sk_wq);
3572 
3573 		/* rely on refcount_sub from sock_wfree() */
3574 		smp_mb__after_atomic();
3575 		if (wq && waitqueue_active(&wq->wait))
3576 			wake_up_interruptible_sync_poll(&wq->wait, EPOLLOUT |
3577 						EPOLLWRNORM | EPOLLWRBAND);
3578 
3579 		/* Should agree with poll, otherwise some programs break */
3580 		sk_wake_async_rcu(sk, SOCK_WAKE_SPACE, POLL_OUT);
3581 	}
3582 }
3583 
sock_def_destruct(struct sock * sk)3584 static void sock_def_destruct(struct sock *sk)
3585 {
3586 }
3587 
sk_send_sigurg(struct sock * sk)3588 void sk_send_sigurg(struct sock *sk)
3589 {
3590 	if (sk->sk_socket && sk->sk_socket->file)
3591 		if (send_sigurg(sk->sk_socket->file))
3592 			sk_wake_async(sk, SOCK_WAKE_URG, POLL_PRI);
3593 }
3594 EXPORT_SYMBOL(sk_send_sigurg);
3595 
sk_reset_timer(struct sock * sk,struct timer_list * timer,unsigned long expires)3596 void sk_reset_timer(struct sock *sk, struct timer_list* timer,
3597 		    unsigned long expires)
3598 {
3599 	if (!mod_timer(timer, expires))
3600 		sock_hold(sk);
3601 }
3602 EXPORT_SYMBOL(sk_reset_timer);
3603 
sk_stop_timer(struct sock * sk,struct timer_list * timer)3604 void sk_stop_timer(struct sock *sk, struct timer_list* timer)
3605 {
3606 	if (timer_delete(timer))
3607 		__sock_put(sk);
3608 }
3609 EXPORT_SYMBOL(sk_stop_timer);
3610 
sk_stop_timer_sync(struct sock * sk,struct timer_list * timer)3611 void sk_stop_timer_sync(struct sock *sk, struct timer_list *timer)
3612 {
3613 	if (timer_delete_sync(timer))
3614 		__sock_put(sk);
3615 }
3616 EXPORT_SYMBOL(sk_stop_timer_sync);
3617 
sock_init_data_uid(struct socket * sock,struct sock * sk,kuid_t uid)3618 void sock_init_data_uid(struct socket *sock, struct sock *sk, kuid_t uid)
3619 {
3620 	sk_init_common(sk);
3621 	sk->sk_send_head	=	NULL;
3622 
3623 	timer_setup(&sk->sk_timer, NULL, 0);
3624 
3625 	sk->sk_allocation	=	GFP_KERNEL;
3626 	sk->sk_rcvbuf		=	READ_ONCE(sysctl_rmem_default);
3627 	sk->sk_sndbuf		=	READ_ONCE(sysctl_wmem_default);
3628 	sk->sk_state		=	TCP_CLOSE;
3629 	sk->sk_use_task_frag	=	true;
3630 	sk_set_socket(sk, sock);
3631 
3632 	sock_set_flag(sk, SOCK_ZAPPED);
3633 
3634 	if (sock) {
3635 		sk->sk_type	=	sock->type;
3636 		RCU_INIT_POINTER(sk->sk_wq, &sock->wq);
3637 		sock->sk	=	sk;
3638 	} else {
3639 		RCU_INIT_POINTER(sk->sk_wq, NULL);
3640 	}
3641 	sk->sk_uid	=	uid;
3642 
3643 	sk->sk_state_change	=	sock_def_wakeup;
3644 	sk->sk_data_ready	=	sock_def_readable;
3645 	sk->sk_write_space	=	sock_def_write_space;
3646 	sk->sk_error_report	=	sock_def_error_report;
3647 	sk->sk_destruct		=	sock_def_destruct;
3648 
3649 	sk->sk_frag.page	=	NULL;
3650 	sk->sk_frag.offset	=	0;
3651 	sk->sk_peek_off		=	-1;
3652 
3653 	sk->sk_peer_pid 	=	NULL;
3654 	sk->sk_peer_cred	=	NULL;
3655 	spin_lock_init(&sk->sk_peer_lock);
3656 
3657 	sk->sk_write_pending	=	0;
3658 	sk->sk_rcvlowat		=	1;
3659 	sk->sk_rcvtimeo		=	MAX_SCHEDULE_TIMEOUT;
3660 	sk->sk_sndtimeo		=	MAX_SCHEDULE_TIMEOUT;
3661 
3662 	sk->sk_stamp = SK_DEFAULT_STAMP;
3663 #if BITS_PER_LONG==32
3664 	seqlock_init(&sk->sk_stamp_seq);
3665 #endif
3666 	atomic_set(&sk->sk_zckey, 0);
3667 
3668 #ifdef CONFIG_NET_RX_BUSY_POLL
3669 	sk->sk_napi_id		=	0;
3670 	sk->sk_ll_usec		=	READ_ONCE(sysctl_net_busy_read);
3671 #endif
3672 
3673 	sk->sk_max_pacing_rate = ~0UL;
3674 	sk->sk_pacing_rate = ~0UL;
3675 	WRITE_ONCE(sk->sk_pacing_shift, 10);
3676 	sk->sk_incoming_cpu = -1;
3677 
3678 	sk_rx_queue_clear(sk);
3679 	/*
3680 	 * Before updating sk_refcnt, we must commit prior changes to memory
3681 	 * (Documentation/RCU/rculist_nulls.rst for details)
3682 	 */
3683 	smp_wmb();
3684 	refcount_set(&sk->sk_refcnt, 1);
3685 	atomic_set(&sk->sk_drops, 0);
3686 }
3687 EXPORT_SYMBOL(sock_init_data_uid);
3688 
sock_init_data(struct socket * sock,struct sock * sk)3689 void sock_init_data(struct socket *sock, struct sock *sk)
3690 {
3691 	kuid_t uid = sock ?
3692 		SOCK_INODE(sock)->i_uid :
3693 		make_kuid(sock_net(sk)->user_ns, 0);
3694 
3695 	sock_init_data_uid(sock, sk, uid);
3696 }
3697 EXPORT_SYMBOL(sock_init_data);
3698 
lock_sock_nested(struct sock * sk,int subclass)3699 void lock_sock_nested(struct sock *sk, int subclass)
3700 {
3701 	/* The sk_lock has mutex_lock() semantics here. */
3702 	mutex_acquire(&sk->sk_lock.dep_map, subclass, 0, _RET_IP_);
3703 
3704 	might_sleep();
3705 	spin_lock_bh(&sk->sk_lock.slock);
3706 	if (sock_owned_by_user_nocheck(sk))
3707 		__lock_sock(sk);
3708 	sk->sk_lock.owned = 1;
3709 	spin_unlock_bh(&sk->sk_lock.slock);
3710 }
3711 EXPORT_SYMBOL(lock_sock_nested);
3712 
release_sock(struct sock * sk)3713 void release_sock(struct sock *sk)
3714 {
3715 	spin_lock_bh(&sk->sk_lock.slock);
3716 	if (sk->sk_backlog.tail)
3717 		__release_sock(sk);
3718 
3719 	if (sk->sk_prot->release_cb)
3720 		INDIRECT_CALL_INET_1(sk->sk_prot->release_cb,
3721 				     tcp_release_cb, sk);
3722 
3723 	sock_release_ownership(sk);
3724 	if (waitqueue_active(&sk->sk_lock.wq))
3725 		wake_up(&sk->sk_lock.wq);
3726 	spin_unlock_bh(&sk->sk_lock.slock);
3727 }
3728 EXPORT_SYMBOL(release_sock);
3729 
__lock_sock_fast(struct sock * sk)3730 bool __lock_sock_fast(struct sock *sk) __acquires(&sk->sk_lock.slock)
3731 {
3732 	might_sleep();
3733 	spin_lock_bh(&sk->sk_lock.slock);
3734 
3735 	if (!sock_owned_by_user_nocheck(sk)) {
3736 		/*
3737 		 * Fast path return with bottom halves disabled and
3738 		 * sock::sk_lock.slock held.
3739 		 *
3740 		 * The 'mutex' is not contended and holding
3741 		 * sock::sk_lock.slock prevents all other lockers to
3742 		 * proceed so the corresponding unlock_sock_fast() can
3743 		 * avoid the slow path of release_sock() completely and
3744 		 * just release slock.
3745 		 *
3746 		 * From a semantical POV this is equivalent to 'acquiring'
3747 		 * the 'mutex', hence the corresponding lockdep
3748 		 * mutex_release() has to happen in the fast path of
3749 		 * unlock_sock_fast().
3750 		 */
3751 		return false;
3752 	}
3753 
3754 	__lock_sock(sk);
3755 	sk->sk_lock.owned = 1;
3756 	__acquire(&sk->sk_lock.slock);
3757 	spin_unlock_bh(&sk->sk_lock.slock);
3758 	return true;
3759 }
3760 EXPORT_SYMBOL(__lock_sock_fast);
3761 
sock_gettstamp(struct socket * sock,void __user * userstamp,bool timeval,bool time32)3762 int sock_gettstamp(struct socket *sock, void __user *userstamp,
3763 		   bool timeval, bool time32)
3764 {
3765 	struct sock *sk = sock->sk;
3766 	struct timespec64 ts;
3767 
3768 	sock_enable_timestamp(sk, SOCK_TIMESTAMP);
3769 	ts = ktime_to_timespec64(sock_read_timestamp(sk));
3770 	if (ts.tv_sec == -1)
3771 		return -ENOENT;
3772 	if (ts.tv_sec == 0) {
3773 		ktime_t kt = ktime_get_real();
3774 		sock_write_timestamp(sk, kt);
3775 		ts = ktime_to_timespec64(kt);
3776 	}
3777 
3778 	if (timeval)
3779 		ts.tv_nsec /= 1000;
3780 
3781 #ifdef CONFIG_COMPAT_32BIT_TIME
3782 	if (time32)
3783 		return put_old_timespec32(&ts, userstamp);
3784 #endif
3785 #ifdef CONFIG_SPARC64
3786 	/* beware of padding in sparc64 timeval */
3787 	if (timeval && !in_compat_syscall()) {
3788 		struct __kernel_old_timeval __user tv = {
3789 			.tv_sec = ts.tv_sec,
3790 			.tv_usec = ts.tv_nsec,
3791 		};
3792 		if (copy_to_user(userstamp, &tv, sizeof(tv)))
3793 			return -EFAULT;
3794 		return 0;
3795 	}
3796 #endif
3797 	return put_timespec64(&ts, userstamp);
3798 }
3799 EXPORT_SYMBOL(sock_gettstamp);
3800 
sock_enable_timestamp(struct sock * sk,enum sock_flags flag)3801 void sock_enable_timestamp(struct sock *sk, enum sock_flags flag)
3802 {
3803 	if (!sock_flag(sk, flag)) {
3804 		unsigned long previous_flags = sk->sk_flags;
3805 
3806 		sock_set_flag(sk, flag);
3807 		/*
3808 		 * we just set one of the two flags which require net
3809 		 * time stamping, but time stamping might have been on
3810 		 * already because of the other one
3811 		 */
3812 		if (sock_needs_netstamp(sk) &&
3813 		    !(previous_flags & SK_FLAGS_TIMESTAMP))
3814 			net_enable_timestamp();
3815 	}
3816 }
3817 
sock_recv_errqueue(struct sock * sk,struct msghdr * msg,int len,int level,int type)3818 int sock_recv_errqueue(struct sock *sk, struct msghdr *msg, int len,
3819 		       int level, int type)
3820 {
3821 	struct sock_exterr_skb *serr;
3822 	struct sk_buff *skb;
3823 	int copied, err;
3824 
3825 	err = -EAGAIN;
3826 	skb = sock_dequeue_err_skb(sk);
3827 	if (skb == NULL)
3828 		goto out;
3829 
3830 	copied = skb->len;
3831 	if (copied > len) {
3832 		msg->msg_flags |= MSG_TRUNC;
3833 		copied = len;
3834 	}
3835 	err = skb_copy_datagram_msg(skb, 0, msg, copied);
3836 	if (err)
3837 		goto out_free_skb;
3838 
3839 	sock_recv_timestamp(msg, sk, skb);
3840 
3841 	serr = SKB_EXT_ERR(skb);
3842 	put_cmsg(msg, level, type, sizeof(serr->ee), &serr->ee);
3843 
3844 	msg->msg_flags |= MSG_ERRQUEUE;
3845 	err = copied;
3846 
3847 out_free_skb:
3848 	kfree_skb(skb);
3849 out:
3850 	return err;
3851 }
3852 EXPORT_SYMBOL(sock_recv_errqueue);
3853 
3854 /*
3855  *	Get a socket option on an socket.
3856  *
3857  *	FIX: POSIX 1003.1g is very ambiguous here. It states that
3858  *	asynchronous errors should be reported by getsockopt. We assume
3859  *	this means if you specify SO_ERROR (otherwise what is the point of it).
3860  */
sock_common_getsockopt(struct socket * sock,int level,int optname,char __user * optval,int __user * optlen)3861 int sock_common_getsockopt(struct socket *sock, int level, int optname,
3862 			   char __user *optval, int __user *optlen)
3863 {
3864 	struct sock *sk = sock->sk;
3865 
3866 	/* IPV6_ADDRFORM can change sk->sk_prot under us. */
3867 	return READ_ONCE(sk->sk_prot)->getsockopt(sk, level, optname, optval, optlen);
3868 }
3869 EXPORT_SYMBOL(sock_common_getsockopt);
3870 
sock_common_recvmsg(struct socket * sock,struct msghdr * msg,size_t size,int flags)3871 int sock_common_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
3872 			int flags)
3873 {
3874 	struct sock *sk = sock->sk;
3875 	int addr_len = 0;
3876 	int err;
3877 
3878 	err = sk->sk_prot->recvmsg(sk, msg, size, flags, &addr_len);
3879 	if (err >= 0)
3880 		msg->msg_namelen = addr_len;
3881 	return err;
3882 }
3883 EXPORT_SYMBOL(sock_common_recvmsg);
3884 
3885 /*
3886  *	Set socket options on an inet socket.
3887  */
sock_common_setsockopt(struct socket * sock,int level,int optname,sockptr_t optval,unsigned int optlen)3888 int sock_common_setsockopt(struct socket *sock, int level, int optname,
3889 			   sockptr_t optval, unsigned int optlen)
3890 {
3891 	struct sock *sk = sock->sk;
3892 
3893 	/* IPV6_ADDRFORM can change sk->sk_prot under us. */
3894 	return READ_ONCE(sk->sk_prot)->setsockopt(sk, level, optname, optval, optlen);
3895 }
3896 EXPORT_SYMBOL(sock_common_setsockopt);
3897 
sk_common_release(struct sock * sk)3898 void sk_common_release(struct sock *sk)
3899 {
3900 	if (sk->sk_prot->destroy)
3901 		sk->sk_prot->destroy(sk);
3902 
3903 	/*
3904 	 * Observation: when sk_common_release is called, processes have
3905 	 * no access to socket. But net still has.
3906 	 * Step one, detach it from networking:
3907 	 *
3908 	 * A. Remove from hash tables.
3909 	 */
3910 
3911 	sk->sk_prot->unhash(sk);
3912 
3913 	/*
3914 	 * In this point socket cannot receive new packets, but it is possible
3915 	 * that some packets are in flight because some CPU runs receiver and
3916 	 * did hash table lookup before we unhashed socket. They will achieve
3917 	 * receive queue and will be purged by socket destructor.
3918 	 *
3919 	 * Also we still have packets pending on receive queue and probably,
3920 	 * our own packets waiting in device queues. sock_destroy will drain
3921 	 * receive queue, but transmitted packets will delay socket destruction
3922 	 * until the last reference will be released.
3923 	 */
3924 
3925 	sock_orphan(sk);
3926 
3927 	xfrm_sk_free_policy(sk);
3928 
3929 	sock_put(sk);
3930 }
3931 EXPORT_SYMBOL(sk_common_release);
3932 
sk_get_meminfo(const struct sock * sk,u32 * mem)3933 void sk_get_meminfo(const struct sock *sk, u32 *mem)
3934 {
3935 	memset(mem, 0, sizeof(*mem) * SK_MEMINFO_VARS);
3936 
3937 	mem[SK_MEMINFO_RMEM_ALLOC] = sk_rmem_alloc_get(sk);
3938 	mem[SK_MEMINFO_RCVBUF] = READ_ONCE(sk->sk_rcvbuf);
3939 	mem[SK_MEMINFO_WMEM_ALLOC] = sk_wmem_alloc_get(sk);
3940 	mem[SK_MEMINFO_SNDBUF] = READ_ONCE(sk->sk_sndbuf);
3941 	mem[SK_MEMINFO_FWD_ALLOC] = READ_ONCE(sk->sk_forward_alloc);
3942 	mem[SK_MEMINFO_WMEM_QUEUED] = READ_ONCE(sk->sk_wmem_queued);
3943 	mem[SK_MEMINFO_OPTMEM] = atomic_read(&sk->sk_omem_alloc);
3944 	mem[SK_MEMINFO_BACKLOG] = READ_ONCE(sk->sk_backlog.len);
3945 	mem[SK_MEMINFO_DROPS] = atomic_read(&sk->sk_drops);
3946 }
3947 
3948 #ifdef CONFIG_PROC_FS
3949 static DECLARE_BITMAP(proto_inuse_idx, PROTO_INUSE_NR);
3950 
sock_prot_inuse_get(struct net * net,struct proto * prot)3951 int sock_prot_inuse_get(struct net *net, struct proto *prot)
3952 {
3953 	int cpu, idx = prot->inuse_idx;
3954 	int res = 0;
3955 
3956 	for_each_possible_cpu(cpu)
3957 		res += per_cpu_ptr(net->core.prot_inuse, cpu)->val[idx];
3958 
3959 	return res >= 0 ? res : 0;
3960 }
3961 EXPORT_SYMBOL_GPL(sock_prot_inuse_get);
3962 
sock_inuse_get(struct net * net)3963 int sock_inuse_get(struct net *net)
3964 {
3965 	int cpu, res = 0;
3966 
3967 	for_each_possible_cpu(cpu)
3968 		res += per_cpu_ptr(net->core.prot_inuse, cpu)->all;
3969 
3970 	return res;
3971 }
3972 
3973 EXPORT_SYMBOL_GPL(sock_inuse_get);
3974 
sock_inuse_init_net(struct net * net)3975 static int __net_init sock_inuse_init_net(struct net *net)
3976 {
3977 	net->core.prot_inuse = alloc_percpu(struct prot_inuse);
3978 	if (net->core.prot_inuse == NULL)
3979 		return -ENOMEM;
3980 	return 0;
3981 }
3982 
sock_inuse_exit_net(struct net * net)3983 static void __net_exit sock_inuse_exit_net(struct net *net)
3984 {
3985 	free_percpu(net->core.prot_inuse);
3986 }
3987 
3988 static struct pernet_operations net_inuse_ops = {
3989 	.init = sock_inuse_init_net,
3990 	.exit = sock_inuse_exit_net,
3991 };
3992 
net_inuse_init(void)3993 static __init int net_inuse_init(void)
3994 {
3995 	if (register_pernet_subsys(&net_inuse_ops))
3996 		panic("Cannot initialize net inuse counters");
3997 
3998 	return 0;
3999 }
4000 
4001 core_initcall(net_inuse_init);
4002 
assign_proto_idx(struct proto * prot)4003 static int assign_proto_idx(struct proto *prot)
4004 {
4005 	prot->inuse_idx = find_first_zero_bit(proto_inuse_idx, PROTO_INUSE_NR);
4006 
4007 	if (unlikely(prot->inuse_idx == PROTO_INUSE_NR - 1)) {
4008 		pr_err("PROTO_INUSE_NR exhausted\n");
4009 		return -ENOSPC;
4010 	}
4011 
4012 	set_bit(prot->inuse_idx, proto_inuse_idx);
4013 	return 0;
4014 }
4015 
release_proto_idx(struct proto * prot)4016 static void release_proto_idx(struct proto *prot)
4017 {
4018 	if (prot->inuse_idx != PROTO_INUSE_NR - 1)
4019 		clear_bit(prot->inuse_idx, proto_inuse_idx);
4020 }
4021 #else
assign_proto_idx(struct proto * prot)4022 static inline int assign_proto_idx(struct proto *prot)
4023 {
4024 	return 0;
4025 }
4026 
release_proto_idx(struct proto * prot)4027 static inline void release_proto_idx(struct proto *prot)
4028 {
4029 }
4030 
4031 #endif
4032 
tw_prot_cleanup(struct timewait_sock_ops * twsk_prot)4033 static void tw_prot_cleanup(struct timewait_sock_ops *twsk_prot)
4034 {
4035 	if (!twsk_prot)
4036 		return;
4037 	kfree(twsk_prot->twsk_slab_name);
4038 	twsk_prot->twsk_slab_name = NULL;
4039 	kmem_cache_destroy(twsk_prot->twsk_slab);
4040 	twsk_prot->twsk_slab = NULL;
4041 }
4042 
tw_prot_init(const struct proto * prot)4043 static int tw_prot_init(const struct proto *prot)
4044 {
4045 	struct timewait_sock_ops *twsk_prot = prot->twsk_prot;
4046 
4047 	if (!twsk_prot)
4048 		return 0;
4049 
4050 	twsk_prot->twsk_slab_name = kasprintf(GFP_KERNEL, "tw_sock_%s",
4051 					      prot->name);
4052 	if (!twsk_prot->twsk_slab_name)
4053 		return -ENOMEM;
4054 
4055 	twsk_prot->twsk_slab =
4056 		kmem_cache_create(twsk_prot->twsk_slab_name,
4057 				  twsk_prot->twsk_obj_size, 0,
4058 				  SLAB_ACCOUNT | prot->slab_flags,
4059 				  NULL);
4060 	if (!twsk_prot->twsk_slab) {
4061 		pr_crit("%s: Can't create timewait sock SLAB cache!\n",
4062 			prot->name);
4063 		return -ENOMEM;
4064 	}
4065 
4066 	return 0;
4067 }
4068 
req_prot_cleanup(struct request_sock_ops * rsk_prot)4069 static void req_prot_cleanup(struct request_sock_ops *rsk_prot)
4070 {
4071 	if (!rsk_prot)
4072 		return;
4073 	kfree(rsk_prot->slab_name);
4074 	rsk_prot->slab_name = NULL;
4075 	kmem_cache_destroy(rsk_prot->slab);
4076 	rsk_prot->slab = NULL;
4077 }
4078 
req_prot_init(const struct proto * prot)4079 static int req_prot_init(const struct proto *prot)
4080 {
4081 	struct request_sock_ops *rsk_prot = prot->rsk_prot;
4082 
4083 	if (!rsk_prot)
4084 		return 0;
4085 
4086 	rsk_prot->slab_name = kasprintf(GFP_KERNEL, "request_sock_%s",
4087 					prot->name);
4088 	if (!rsk_prot->slab_name)
4089 		return -ENOMEM;
4090 
4091 	rsk_prot->slab = kmem_cache_create(rsk_prot->slab_name,
4092 					   rsk_prot->obj_size, 0,
4093 					   SLAB_ACCOUNT | prot->slab_flags,
4094 					   NULL);
4095 
4096 	if (!rsk_prot->slab) {
4097 		pr_crit("%s: Can't create request sock SLAB cache!\n",
4098 			prot->name);
4099 		return -ENOMEM;
4100 	}
4101 	return 0;
4102 }
4103 
proto_register(struct proto * prot,int alloc_slab)4104 int proto_register(struct proto *prot, int alloc_slab)
4105 {
4106 	int ret = -ENOBUFS;
4107 
4108 	if (prot->memory_allocated && !prot->sysctl_mem) {
4109 		pr_err("%s: missing sysctl_mem\n", prot->name);
4110 		return -EINVAL;
4111 	}
4112 	if (prot->memory_allocated && !prot->per_cpu_fw_alloc) {
4113 		pr_err("%s: missing per_cpu_fw_alloc\n", prot->name);
4114 		return -EINVAL;
4115 	}
4116 	if (alloc_slab) {
4117 		prot->slab = kmem_cache_create_usercopy(prot->name,
4118 					prot->obj_size, 0,
4119 					SLAB_HWCACHE_ALIGN | SLAB_ACCOUNT |
4120 					prot->slab_flags,
4121 					prot->useroffset, prot->usersize,
4122 					NULL);
4123 
4124 		if (prot->slab == NULL) {
4125 			pr_crit("%s: Can't create sock SLAB cache!\n",
4126 				prot->name);
4127 			goto out;
4128 		}
4129 
4130 		if (req_prot_init(prot))
4131 			goto out_free_request_sock_slab;
4132 
4133 		if (tw_prot_init(prot))
4134 			goto out_free_timewait_sock_slab;
4135 	}
4136 
4137 	mutex_lock(&proto_list_mutex);
4138 	ret = assign_proto_idx(prot);
4139 	if (ret) {
4140 		mutex_unlock(&proto_list_mutex);
4141 		goto out_free_timewait_sock_slab;
4142 	}
4143 	list_add(&prot->node, &proto_list);
4144 	mutex_unlock(&proto_list_mutex);
4145 	return ret;
4146 
4147 out_free_timewait_sock_slab:
4148 	if (alloc_slab)
4149 		tw_prot_cleanup(prot->twsk_prot);
4150 out_free_request_sock_slab:
4151 	if (alloc_slab) {
4152 		req_prot_cleanup(prot->rsk_prot);
4153 
4154 		kmem_cache_destroy(prot->slab);
4155 		prot->slab = NULL;
4156 	}
4157 out:
4158 	return ret;
4159 }
4160 EXPORT_SYMBOL(proto_register);
4161 
proto_unregister(struct proto * prot)4162 void proto_unregister(struct proto *prot)
4163 {
4164 	mutex_lock(&proto_list_mutex);
4165 	release_proto_idx(prot);
4166 	list_del(&prot->node);
4167 	mutex_unlock(&proto_list_mutex);
4168 
4169 	kmem_cache_destroy(prot->slab);
4170 	prot->slab = NULL;
4171 
4172 	req_prot_cleanup(prot->rsk_prot);
4173 	tw_prot_cleanup(prot->twsk_prot);
4174 }
4175 EXPORT_SYMBOL(proto_unregister);
4176 
sock_load_diag_module(int family,int protocol)4177 int sock_load_diag_module(int family, int protocol)
4178 {
4179 	if (!protocol) {
4180 		if (!sock_is_registered(family))
4181 			return -ENOENT;
4182 
4183 		return request_module("net-pf-%d-proto-%d-type-%d", PF_NETLINK,
4184 				      NETLINK_SOCK_DIAG, family);
4185 	}
4186 
4187 #ifdef CONFIG_INET
4188 	if (family == AF_INET &&
4189 	    protocol != IPPROTO_RAW &&
4190 	    protocol < MAX_INET_PROTOS &&
4191 	    !rcu_access_pointer(inet_protos[protocol]))
4192 		return -ENOENT;
4193 #endif
4194 
4195 	return request_module("net-pf-%d-proto-%d-type-%d-%d", PF_NETLINK,
4196 			      NETLINK_SOCK_DIAG, family, protocol);
4197 }
4198 EXPORT_SYMBOL(sock_load_diag_module);
4199 
4200 #ifdef CONFIG_PROC_FS
proto_seq_start(struct seq_file * seq,loff_t * pos)4201 static void *proto_seq_start(struct seq_file *seq, loff_t *pos)
4202 	__acquires(proto_list_mutex)
4203 {
4204 	mutex_lock(&proto_list_mutex);
4205 	return seq_list_start_head(&proto_list, *pos);
4206 }
4207 
proto_seq_next(struct seq_file * seq,void * v,loff_t * pos)4208 static void *proto_seq_next(struct seq_file *seq, void *v, loff_t *pos)
4209 {
4210 	return seq_list_next(v, &proto_list, pos);
4211 }
4212 
proto_seq_stop(struct seq_file * seq,void * v)4213 static void proto_seq_stop(struct seq_file *seq, void *v)
4214 	__releases(proto_list_mutex)
4215 {
4216 	mutex_unlock(&proto_list_mutex);
4217 }
4218 
proto_method_implemented(const void * method)4219 static char proto_method_implemented(const void *method)
4220 {
4221 	return method == NULL ? 'n' : 'y';
4222 }
sock_prot_memory_allocated(struct proto * proto)4223 static long sock_prot_memory_allocated(struct proto *proto)
4224 {
4225 	return proto->memory_allocated != NULL ? proto_memory_allocated(proto) : -1L;
4226 }
4227 
sock_prot_memory_pressure(struct proto * proto)4228 static const char *sock_prot_memory_pressure(struct proto *proto)
4229 {
4230 	return proto->memory_pressure != NULL ?
4231 	proto_memory_pressure(proto) ? "yes" : "no" : "NI";
4232 }
4233 
proto_seq_printf(struct seq_file * seq,struct proto * proto)4234 static void proto_seq_printf(struct seq_file *seq, struct proto *proto)
4235 {
4236 
4237 	seq_printf(seq, "%-9s %4u %6d  %6ld   %-3s %6u   %-3s  %-10s "
4238 			"%2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c\n",
4239 		   proto->name,
4240 		   proto->obj_size,
4241 		   sock_prot_inuse_get(seq_file_net(seq), proto),
4242 		   sock_prot_memory_allocated(proto),
4243 		   sock_prot_memory_pressure(proto),
4244 		   proto->max_header,
4245 		   proto->slab == NULL ? "no" : "yes",
4246 		   module_name(proto->owner),
4247 		   proto_method_implemented(proto->close),
4248 		   proto_method_implemented(proto->connect),
4249 		   proto_method_implemented(proto->disconnect),
4250 		   proto_method_implemented(proto->accept),
4251 		   proto_method_implemented(proto->ioctl),
4252 		   proto_method_implemented(proto->init),
4253 		   proto_method_implemented(proto->destroy),
4254 		   proto_method_implemented(proto->shutdown),
4255 		   proto_method_implemented(proto->setsockopt),
4256 		   proto_method_implemented(proto->getsockopt),
4257 		   proto_method_implemented(proto->sendmsg),
4258 		   proto_method_implemented(proto->recvmsg),
4259 		   proto_method_implemented(proto->bind),
4260 		   proto_method_implemented(proto->backlog_rcv),
4261 		   proto_method_implemented(proto->hash),
4262 		   proto_method_implemented(proto->unhash),
4263 		   proto_method_implemented(proto->get_port),
4264 		   proto_method_implemented(proto->enter_memory_pressure));
4265 }
4266 
proto_seq_show(struct seq_file * seq,void * v)4267 static int proto_seq_show(struct seq_file *seq, void *v)
4268 {
4269 	if (v == &proto_list)
4270 		seq_printf(seq, "%-9s %-4s %-8s %-6s %-5s %-7s %-4s %-10s %s",
4271 			   "protocol",
4272 			   "size",
4273 			   "sockets",
4274 			   "memory",
4275 			   "press",
4276 			   "maxhdr",
4277 			   "slab",
4278 			   "module",
4279 			   "cl co di ac io in de sh ss gs se re bi br ha uh gp em\n");
4280 	else
4281 		proto_seq_printf(seq, list_entry(v, struct proto, node));
4282 	return 0;
4283 }
4284 
4285 static const struct seq_operations proto_seq_ops = {
4286 	.start  = proto_seq_start,
4287 	.next   = proto_seq_next,
4288 	.stop   = proto_seq_stop,
4289 	.show   = proto_seq_show,
4290 };
4291 
proto_init_net(struct net * net)4292 static __net_init int proto_init_net(struct net *net)
4293 {
4294 	if (!proc_create_net("protocols", 0444, net->proc_net, &proto_seq_ops,
4295 			sizeof(struct seq_net_private)))
4296 		return -ENOMEM;
4297 
4298 	return 0;
4299 }
4300 
proto_exit_net(struct net * net)4301 static __net_exit void proto_exit_net(struct net *net)
4302 {
4303 	remove_proc_entry("protocols", net->proc_net);
4304 }
4305 
4306 
4307 static __net_initdata struct pernet_operations proto_net_ops = {
4308 	.init = proto_init_net,
4309 	.exit = proto_exit_net,
4310 };
4311 
proto_init(void)4312 static int __init proto_init(void)
4313 {
4314 	return register_pernet_subsys(&proto_net_ops);
4315 }
4316 
4317 subsys_initcall(proto_init);
4318 
4319 #endif /* PROC_FS */
4320 
4321 #ifdef CONFIG_NET_RX_BUSY_POLL
sk_busy_loop_end(void * p,unsigned long start_time)4322 bool sk_busy_loop_end(void *p, unsigned long start_time)
4323 {
4324 	struct sock *sk = p;
4325 
4326 	if (!skb_queue_empty_lockless(&sk->sk_receive_queue))
4327 		return true;
4328 
4329 	if (sk_is_udp(sk) &&
4330 	    !skb_queue_empty_lockless(&udp_sk(sk)->reader_queue))
4331 		return true;
4332 
4333 	return sk_busy_loop_timeout(sk, start_time);
4334 }
4335 EXPORT_SYMBOL(sk_busy_loop_end);
4336 #endif /* CONFIG_NET_RX_BUSY_POLL */
4337 
sock_bind_add(struct sock * sk,struct sockaddr * addr,int addr_len)4338 int sock_bind_add(struct sock *sk, struct sockaddr *addr, int addr_len)
4339 {
4340 	if (!sk->sk_prot->bind_add)
4341 		return -EOPNOTSUPP;
4342 	return sk->sk_prot->bind_add(sk, addr, addr_len);
4343 }
4344 EXPORT_SYMBOL(sock_bind_add);
4345 
4346 /* 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)4347 int sock_ioctl_inout(struct sock *sk, unsigned int cmd,
4348 		     void __user *arg, void *karg, size_t size)
4349 {
4350 	int ret;
4351 
4352 	if (copy_from_user(karg, arg, size))
4353 		return -EFAULT;
4354 
4355 	ret = READ_ONCE(sk->sk_prot)->ioctl(sk, cmd, karg);
4356 	if (ret)
4357 		return ret;
4358 
4359 	if (copy_to_user(arg, karg, size))
4360 		return -EFAULT;
4361 
4362 	return 0;
4363 }
4364 EXPORT_SYMBOL(sock_ioctl_inout);
4365 
4366 /* This is the most common ioctl prep function, where the result (4 bytes) is
4367  * copied back to userspace if the ioctl() returns successfully. No input is
4368  * copied from userspace as input argument.
4369  */
sock_ioctl_out(struct sock * sk,unsigned int cmd,void __user * arg)4370 static int sock_ioctl_out(struct sock *sk, unsigned int cmd, void __user *arg)
4371 {
4372 	int ret, karg = 0;
4373 
4374 	ret = READ_ONCE(sk->sk_prot)->ioctl(sk, cmd, &karg);
4375 	if (ret)
4376 		return ret;
4377 
4378 	return put_user(karg, (int __user *)arg);
4379 }
4380 
4381 /* A wrapper around sock ioctls, which copies the data from userspace
4382  * (depending on the protocol/ioctl), and copies back the result to userspace.
4383  * The main motivation for this function is to pass kernel memory to the
4384  * protocol ioctl callbacks, instead of userspace memory.
4385  */
sk_ioctl(struct sock * sk,unsigned int cmd,void __user * arg)4386 int sk_ioctl(struct sock *sk, unsigned int cmd, void __user *arg)
4387 {
4388 	int rc = 1;
4389 
4390 	if (sk->sk_type == SOCK_RAW && sk->sk_family == AF_INET)
4391 		rc = ipmr_sk_ioctl(sk, cmd, arg);
4392 	else if (sk->sk_type == SOCK_RAW && sk->sk_family == AF_INET6)
4393 		rc = ip6mr_sk_ioctl(sk, cmd, arg);
4394 	else if (sk_is_phonet(sk))
4395 		rc = phonet_sk_ioctl(sk, cmd, arg);
4396 
4397 	/* If ioctl was processed, returns its value */
4398 	if (rc <= 0)
4399 		return rc;
4400 
4401 	/* Otherwise call the default handler */
4402 	return sock_ioctl_out(sk, cmd, arg);
4403 }
4404 EXPORT_SYMBOL(sk_ioctl);
4405 
sock_struct_check(void)4406 static int __init sock_struct_check(void)
4407 {
4408 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_rx, sk_drops);
4409 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_rx, sk_peek_off);
4410 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_rx, sk_error_queue);
4411 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_rx, sk_receive_queue);
4412 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_rx, sk_backlog);
4413 
4414 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_rx, sk_rx_dst);
4415 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_rx, sk_rx_dst_ifindex);
4416 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_rx, sk_rx_dst_cookie);
4417 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_rx, sk_rcvbuf);
4418 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_rx, sk_filter);
4419 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_rx, sk_wq);
4420 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_rx, sk_data_ready);
4421 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_rx, sk_rcvtimeo);
4422 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_rx, sk_rcvlowat);
4423 
4424 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_rxtx, sk_err);
4425 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_rxtx, sk_socket);
4426 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_rxtx, sk_memcg);
4427 
4428 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_rxtx, sk_lock);
4429 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_rxtx, sk_reserved_mem);
4430 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_rxtx, sk_forward_alloc);
4431 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_rxtx, sk_tsflags);
4432 
4433 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_omem_alloc);
4434 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_omem_alloc);
4435 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_sndbuf);
4436 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_wmem_queued);
4437 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_wmem_alloc);
4438 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_tsq_flags);
4439 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_send_head);
4440 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_write_queue);
4441 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_write_pending);
4442 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_dst_pending_confirm);
4443 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_pacing_status);
4444 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_frag);
4445 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_timer);
4446 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_pacing_rate);
4447 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_zckey);
4448 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_write_tx, sk_tskey);
4449 
4450 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_max_pacing_rate);
4451 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_sndtimeo);
4452 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_priority);
4453 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_mark);
4454 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_dst_cache);
4455 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_route_caps);
4456 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_gso_type);
4457 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_gso_max_size);
4458 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_allocation);
4459 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_txhash);
4460 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_gso_max_segs);
4461 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_pacing_shift);
4462 	CACHELINE_ASSERT_GROUP_MEMBER(struct sock, sock_read_tx, sk_use_task_frag);
4463 	return 0;
4464 }
4465 
4466 core_initcall(sock_struct_check);
4467