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