xref: /linux/net/socket.c (revision eec8359f0797ef87c6ef6cbed6de08b02073b833)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * NET		An implementation of the SOCKET network access protocol.
4  *
5  * Version:	@(#)socket.c	1.1.93	18/02/95
6  *
7  * Authors:	Orest Zborowski, <obz@Kodak.COM>
8  *		Ross Biro
9  *		Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
10  *
11  * Fixes:
12  *		Anonymous	:	NOTSOCK/BADF cleanup. Error fix in
13  *					shutdown()
14  *		Alan Cox	:	verify_area() fixes
15  *		Alan Cox	:	Removed DDI
16  *		Jonathan Kamens	:	SOCK_DGRAM reconnect bug
17  *		Alan Cox	:	Moved a load of checks to the very
18  *					top level.
19  *		Alan Cox	:	Move address structures to/from user
20  *					mode above the protocol layers.
21  *		Rob Janssen	:	Allow 0 length sends.
22  *		Alan Cox	:	Asynchronous I/O support (cribbed from the
23  *					tty drivers).
24  *		Niibe Yutaka	:	Asynchronous I/O for writes (4.4BSD style)
25  *		Jeff Uphoff	:	Made max number of sockets command-line
26  *					configurable.
27  *		Matti Aarnio	:	Made the number of sockets dynamic,
28  *					to be allocated when needed, and mr.
29  *					Uphoff's max is used as max to be
30  *					allowed to allocate.
31  *		Linus		:	Argh. removed all the socket allocation
32  *					altogether: it's in the inode now.
33  *		Alan Cox	:	Made sock_alloc()/sock_release() public
34  *					for NetROM and future kernel nfsd type
35  *					stuff.
36  *		Alan Cox	:	sendmsg/recvmsg basics.
37  *		Tom Dyas	:	Export net symbols.
38  *		Marcin Dalecki	:	Fixed problems with CONFIG_NET="n".
39  *		Alan Cox	:	Added thread locking to sys_* calls
40  *					for sockets. May have errors at the
41  *					moment.
42  *		Kevin Buhr	:	Fixed the dumb errors in the above.
43  *		Andi Kleen	:	Some small cleanups, optimizations,
44  *					and fixed a copy_from_user() bug.
45  *		Tigran Aivazian	:	sys_send(args) calls sys_sendto(args, NULL, 0)
46  *		Tigran Aivazian	:	Made listen(2) backlog sanity checks
47  *					protocol-independent
48  *
49  *	This module is effectively the top level interface to the BSD socket
50  *	paradigm.
51  *
52  *	Based upon Swansea University Computer Society NET3.039
53  */
54 
55 #include <linux/bpf-cgroup.h>
56 #include <linux/ethtool.h>
57 #include <linux/mm.h>
58 #include <linux/socket.h>
59 #include <linux/file.h>
60 #include <linux/splice.h>
61 #include <linux/net.h>
62 #include <linux/interrupt.h>
63 #include <linux/thread_info.h>
64 #include <linux/rcupdate.h>
65 #include <linux/netdevice.h>
66 #include <linux/proc_fs.h>
67 #include <linux/seq_file.h>
68 #include <linux/mutex.h>
69 #include <linux/if_bridge.h>
70 #include <linux/if_vlan.h>
71 #include <linux/ptp_classify.h>
72 #include <linux/init.h>
73 #include <linux/poll.h>
74 #include <linux/cache.h>
75 #include <linux/module.h>
76 #include <linux/highmem.h>
77 #include <linux/mount.h>
78 #include <linux/pseudo_fs.h>
79 #include <linux/security.h>
80 #include <linux/syscalls.h>
81 #include <linux/compat.h>
82 #include <linux/kmod.h>
83 #include <linux/audit.h>
84 #include <linux/wireless.h>
85 #include <linux/nsproxy.h>
86 #include <linux/magic.h>
87 #include <linux/slab.h>
88 #include <linux/xattr.h>
89 #include <linux/nospec.h>
90 #include <linux/indirect_call_wrapper.h>
91 #include <linux/io_uring/net.h>
92 
93 #include <linux/uaccess.h>
94 #include <asm/unistd.h>
95 
96 #include <net/compat.h>
97 #include <net/wext.h>
98 #include <net/cls_cgroup.h>
99 
100 #include <net/sock.h>
101 #include <linux/netfilter.h>
102 
103 #include <linux/if_tun.h>
104 #include <linux/ipv6_route.h>
105 #include <linux/route.h>
106 #include <linux/termios.h>
107 #include <linux/sockios.h>
108 #include <net/busy_poll.h>
109 #include <linux/errqueue.h>
110 #include <linux/ptp_clock_kernel.h>
111 #include <trace/events/sock.h>
112 
113 #include "core/dev.h"
114 
115 #ifdef CONFIG_NET_RX_BUSY_POLL
116 unsigned int sysctl_net_busy_read __read_mostly;
117 unsigned int sysctl_net_busy_poll __read_mostly;
118 #endif
119 
120 static ssize_t sock_read_iter(struct kiocb *iocb, struct iov_iter *to);
121 static ssize_t sock_write_iter(struct kiocb *iocb, struct iov_iter *from);
122 static int sock_mmap(struct file *file, struct vm_area_struct *vma);
123 
124 static int sock_close(struct inode *inode, struct file *file);
125 static __poll_t sock_poll(struct file *file,
126 			      struct poll_table_struct *wait);
127 static long sock_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
128 #ifdef CONFIG_COMPAT
129 static long compat_sock_ioctl(struct file *file,
130 			      unsigned int cmd, unsigned long arg);
131 #endif
132 static int sock_fasync(int fd, struct file *filp, int on);
133 static ssize_t sock_splice_read(struct file *file, loff_t *ppos,
134 				struct pipe_inode_info *pipe, size_t len,
135 				unsigned int flags);
136 static void sock_splice_eof(struct file *file);
137 
138 #ifdef CONFIG_PROC_FS
139 static void sock_show_fdinfo(struct seq_file *m, struct file *f)
140 {
141 	struct socket *sock = f->private_data;
142 	const struct proto_ops *ops = READ_ONCE(sock->ops);
143 
144 	if (ops->show_fdinfo)
145 		ops->show_fdinfo(m, sock);
146 }
147 #else
148 #define sock_show_fdinfo NULL
149 #endif
150 
151 /*
152  *	Socket files have a set of 'special' operations as well as the generic file ones. These don't appear
153  *	in the operation structures but are done directly via the socketcall() multiplexor.
154  */
155 
156 static const struct file_operations socket_file_ops = {
157 	.owner =	THIS_MODULE,
158 	.read_iter =	sock_read_iter,
159 	.write_iter =	sock_write_iter,
160 	.poll =		sock_poll,
161 	.unlocked_ioctl = sock_ioctl,
162 #ifdef CONFIG_COMPAT
163 	.compat_ioctl = compat_sock_ioctl,
164 #endif
165 	.uring_cmd =    io_uring_cmd_sock,
166 	.mmap =		sock_mmap,
167 	.release =	sock_close,
168 	.fasync =	sock_fasync,
169 	.splice_write = splice_to_socket,
170 	.splice_read =	sock_splice_read,
171 	.splice_eof =	sock_splice_eof,
172 	.show_fdinfo =	sock_show_fdinfo,
173 };
174 
175 static const char * const pf_family_names[] = {
176 	[PF_UNSPEC]	= "PF_UNSPEC",
177 	[PF_UNIX]	= "PF_UNIX/PF_LOCAL",
178 	[PF_INET]	= "PF_INET",
179 	[PF_AX25]	= "PF_AX25",
180 	[PF_IPX]	= "PF_IPX",
181 	[PF_APPLETALK]	= "PF_APPLETALK",
182 	[PF_NETROM]	= "PF_NETROM",
183 	[PF_BRIDGE]	= "PF_BRIDGE",
184 	[PF_ATMPVC]	= "PF_ATMPVC",
185 	[PF_X25]	= "PF_X25",
186 	[PF_INET6]	= "PF_INET6",
187 	[PF_ROSE]	= "PF_ROSE",
188 	[PF_DECnet]	= "PF_DECnet",
189 	[PF_NETBEUI]	= "PF_NETBEUI",
190 	[PF_SECURITY]	= "PF_SECURITY",
191 	[PF_KEY]	= "PF_KEY",
192 	[PF_NETLINK]	= "PF_NETLINK/PF_ROUTE",
193 	[PF_PACKET]	= "PF_PACKET",
194 	[PF_ASH]	= "PF_ASH",
195 	[PF_ECONET]	= "PF_ECONET",
196 	[PF_ATMSVC]	= "PF_ATMSVC",
197 	[PF_RDS]	= "PF_RDS",
198 	[PF_SNA]	= "PF_SNA",
199 	[PF_IRDA]	= "PF_IRDA",
200 	[PF_PPPOX]	= "PF_PPPOX",
201 	[PF_WANPIPE]	= "PF_WANPIPE",
202 	[PF_LLC]	= "PF_LLC",
203 	[PF_IB]		= "PF_IB",
204 	[PF_MPLS]	= "PF_MPLS",
205 	[PF_CAN]	= "PF_CAN",
206 	[PF_TIPC]	= "PF_TIPC",
207 	[PF_BLUETOOTH]	= "PF_BLUETOOTH",
208 	[PF_IUCV]	= "PF_IUCV",
209 	[PF_RXRPC]	= "PF_RXRPC",
210 	[PF_ISDN]	= "PF_ISDN",
211 	[PF_PHONET]	= "PF_PHONET",
212 	[PF_IEEE802154]	= "PF_IEEE802154",
213 	[PF_CAIF]	= "PF_CAIF",
214 	[PF_ALG]	= "PF_ALG",
215 	[PF_NFC]	= "PF_NFC",
216 	[PF_VSOCK]	= "PF_VSOCK",
217 	[PF_KCM]	= "PF_KCM",
218 	[PF_QIPCRTR]	= "PF_QIPCRTR",
219 	[PF_SMC]	= "PF_SMC",
220 	[PF_XDP]	= "PF_XDP",
221 	[PF_MCTP]	= "PF_MCTP",
222 };
223 
224 /*
225  *	The protocol list. Each protocol is registered in here.
226  */
227 
228 static DEFINE_SPINLOCK(net_family_lock);
229 static const struct net_proto_family __rcu *net_families[NPROTO] __read_mostly;
230 
231 /*
232  * Support routines.
233  * Move socket addresses back and forth across the kernel/user
234  * divide and look after the messy bits.
235  */
236 
237 /**
238  *	move_addr_to_kernel	-	copy a socket address into kernel space
239  *	@uaddr: Address in user space
240  *	@kaddr: Address in kernel space
241  *	@ulen: Length in user space
242  *
243  *	The address is copied into kernel space. If the provided address is
244  *	too long an error code of -EINVAL is returned. If the copy gives
245  *	invalid addresses -EFAULT is returned. On a success 0 is returned.
246  */
247 
248 int move_addr_to_kernel(void __user *uaddr, int ulen, struct sockaddr_storage *kaddr)
249 {
250 	if (ulen < 0 || ulen > sizeof(struct sockaddr_storage))
251 		return -EINVAL;
252 	if (ulen == 0)
253 		return 0;
254 	if (copy_from_user(kaddr, uaddr, ulen))
255 		return -EFAULT;
256 	return audit_sockaddr(ulen, kaddr);
257 }
258 
259 /**
260  *	move_addr_to_user	-	copy an address to user space
261  *	@kaddr: kernel space address
262  *	@klen: length of address in kernel
263  *	@uaddr: user space address
264  *	@ulen: pointer to user length field
265  *
266  *	The value pointed to by ulen on entry is the buffer length available.
267  *	This is overwritten with the buffer space used. -EINVAL is returned
268  *	if an overlong buffer is specified or a negative buffer size. -EFAULT
269  *	is returned if either the buffer or the length field are not
270  *	accessible.
271  *	After copying the data up to the limit the user specifies, the true
272  *	length of the data is written over the length limit the user
273  *	specified. Zero is returned for a success.
274  */
275 
276 static int move_addr_to_user(struct sockaddr_storage *kaddr, int klen,
277 			     void __user *uaddr, int __user *ulen)
278 {
279 	int err;
280 	int len;
281 
282 	BUG_ON(klen > sizeof(struct sockaddr_storage));
283 	err = get_user(len, ulen);
284 	if (err)
285 		return err;
286 	if (len > klen)
287 		len = klen;
288 	if (len < 0)
289 		return -EINVAL;
290 	if (len) {
291 		if (audit_sockaddr(klen, kaddr))
292 			return -ENOMEM;
293 		if (copy_to_user(uaddr, kaddr, len))
294 			return -EFAULT;
295 	}
296 	/*
297 	 *      "fromlen shall refer to the value before truncation.."
298 	 *                      1003.1g
299 	 */
300 	return __put_user(klen, ulen);
301 }
302 
303 static struct kmem_cache *sock_inode_cachep __ro_after_init;
304 
305 static struct inode *sock_alloc_inode(struct super_block *sb)
306 {
307 	struct socket_alloc *ei;
308 
309 	ei = alloc_inode_sb(sb, sock_inode_cachep, GFP_KERNEL);
310 	if (!ei)
311 		return NULL;
312 	init_waitqueue_head(&ei->socket.wq.wait);
313 	ei->socket.wq.fasync_list = NULL;
314 	ei->socket.wq.flags = 0;
315 
316 	ei->socket.state = SS_UNCONNECTED;
317 	ei->socket.flags = 0;
318 	ei->socket.ops = NULL;
319 	ei->socket.sk = NULL;
320 	ei->socket.file = NULL;
321 
322 	return &ei->vfs_inode;
323 }
324 
325 static void sock_free_inode(struct inode *inode)
326 {
327 	struct socket_alloc *ei;
328 
329 	ei = container_of(inode, struct socket_alloc, vfs_inode);
330 	kmem_cache_free(sock_inode_cachep, ei);
331 }
332 
333 static void init_once(void *foo)
334 {
335 	struct socket_alloc *ei = (struct socket_alloc *)foo;
336 
337 	inode_init_once(&ei->vfs_inode);
338 }
339 
340 static void init_inodecache(void)
341 {
342 	sock_inode_cachep = kmem_cache_create("sock_inode_cache",
343 					      sizeof(struct socket_alloc),
344 					      0,
345 					      (SLAB_HWCACHE_ALIGN |
346 					       SLAB_RECLAIM_ACCOUNT |
347 					       SLAB_ACCOUNT),
348 					      init_once);
349 	BUG_ON(sock_inode_cachep == NULL);
350 }
351 
352 static const struct super_operations sockfs_ops = {
353 	.alloc_inode	= sock_alloc_inode,
354 	.free_inode	= sock_free_inode,
355 	.statfs		= simple_statfs,
356 };
357 
358 /*
359  * sockfs_dname() is called from d_path().
360  */
361 static char *sockfs_dname(struct dentry *dentry, char *buffer, int buflen)
362 {
363 	return dynamic_dname(buffer, buflen, "socket:[%lu]",
364 				d_inode(dentry)->i_ino);
365 }
366 
367 static const struct dentry_operations sockfs_dentry_operations = {
368 	.d_dname  = sockfs_dname,
369 };
370 
371 static int sockfs_xattr_get(const struct xattr_handler *handler,
372 			    struct dentry *dentry, struct inode *inode,
373 			    const char *suffix, void *value, size_t size)
374 {
375 	if (value) {
376 		if (dentry->d_name.len + 1 > size)
377 			return -ERANGE;
378 		memcpy(value, dentry->d_name.name, dentry->d_name.len + 1);
379 	}
380 	return dentry->d_name.len + 1;
381 }
382 
383 #define XATTR_SOCKPROTONAME_SUFFIX "sockprotoname"
384 #define XATTR_NAME_SOCKPROTONAME (XATTR_SYSTEM_PREFIX XATTR_SOCKPROTONAME_SUFFIX)
385 #define XATTR_NAME_SOCKPROTONAME_LEN (sizeof(XATTR_NAME_SOCKPROTONAME)-1)
386 
387 static const struct xattr_handler sockfs_xattr_handler = {
388 	.name = XATTR_NAME_SOCKPROTONAME,
389 	.get = sockfs_xattr_get,
390 };
391 
392 static int sockfs_security_xattr_set(const struct xattr_handler *handler,
393 				     struct mnt_idmap *idmap,
394 				     struct dentry *dentry, struct inode *inode,
395 				     const char *suffix, const void *value,
396 				     size_t size, int flags)
397 {
398 	/* Handled by LSM. */
399 	return -EAGAIN;
400 }
401 
402 static const struct xattr_handler sockfs_security_xattr_handler = {
403 	.prefix = XATTR_SECURITY_PREFIX,
404 	.set = sockfs_security_xattr_set,
405 };
406 
407 static const struct xattr_handler * const sockfs_xattr_handlers[] = {
408 	&sockfs_xattr_handler,
409 	&sockfs_security_xattr_handler,
410 	NULL
411 };
412 
413 static int sockfs_init_fs_context(struct fs_context *fc)
414 {
415 	struct pseudo_fs_context *ctx = init_pseudo(fc, SOCKFS_MAGIC);
416 	if (!ctx)
417 		return -ENOMEM;
418 	ctx->ops = &sockfs_ops;
419 	ctx->dops = &sockfs_dentry_operations;
420 	ctx->xattr = sockfs_xattr_handlers;
421 	return 0;
422 }
423 
424 static struct vfsmount *sock_mnt __read_mostly;
425 
426 static struct file_system_type sock_fs_type = {
427 	.name =		"sockfs",
428 	.init_fs_context = sockfs_init_fs_context,
429 	.kill_sb =	kill_anon_super,
430 };
431 
432 /*
433  *	Obtains the first available file descriptor and sets it up for use.
434  *
435  *	These functions create file structures and maps them to fd space
436  *	of the current process. On success it returns file descriptor
437  *	and file struct implicitly stored in sock->file.
438  *	Note that another thread may close file descriptor before we return
439  *	from this function. We use the fact that now we do not refer
440  *	to socket after mapping. If one day we will need it, this
441  *	function will increment ref. count on file by 1.
442  *
443  *	In any case returned fd MAY BE not valid!
444  *	This race condition is unavoidable
445  *	with shared fd spaces, we cannot solve it inside kernel,
446  *	but we take care of internal coherence yet.
447  */
448 
449 /**
450  *	sock_alloc_file - Bind a &socket to a &file
451  *	@sock: socket
452  *	@flags: file status flags
453  *	@dname: protocol name
454  *
455  *	Returns the &file bound with @sock, implicitly storing it
456  *	in sock->file. If dname is %NULL, sets to "".
457  *
458  *	On failure @sock is released, and an ERR pointer is returned.
459  *
460  *	This function uses GFP_KERNEL internally.
461  */
462 
463 struct file *sock_alloc_file(struct socket *sock, int flags, const char *dname)
464 {
465 	struct file *file;
466 
467 	if (!dname)
468 		dname = sock->sk ? sock->sk->sk_prot_creator->name : "";
469 
470 	file = alloc_file_pseudo(SOCK_INODE(sock), sock_mnt, dname,
471 				O_RDWR | (flags & O_NONBLOCK),
472 				&socket_file_ops);
473 	if (IS_ERR(file)) {
474 		sock_release(sock);
475 		return file;
476 	}
477 
478 	file->f_mode |= FMODE_NOWAIT;
479 	sock->file = file;
480 	file->private_data = sock;
481 	stream_open(SOCK_INODE(sock), file);
482 	return file;
483 }
484 EXPORT_SYMBOL(sock_alloc_file);
485 
486 static int sock_map_fd(struct socket *sock, int flags)
487 {
488 	struct file *newfile;
489 	int fd = get_unused_fd_flags(flags);
490 	if (unlikely(fd < 0)) {
491 		sock_release(sock);
492 		return fd;
493 	}
494 
495 	newfile = sock_alloc_file(sock, flags, NULL);
496 	if (!IS_ERR(newfile)) {
497 		fd_install(fd, newfile);
498 		return fd;
499 	}
500 
501 	put_unused_fd(fd);
502 	return PTR_ERR(newfile);
503 }
504 
505 /**
506  *	sock_from_file - Return the &socket bounded to @file.
507  *	@file: file
508  *
509  *	On failure returns %NULL.
510  */
511 
512 struct socket *sock_from_file(struct file *file)
513 {
514 	if (likely(file->f_op == &socket_file_ops))
515 		return file->private_data;	/* set in sock_alloc_file */
516 
517 	return NULL;
518 }
519 EXPORT_SYMBOL(sock_from_file);
520 
521 /**
522  *	sockfd_lookup - Go from a file number to its socket slot
523  *	@fd: file handle
524  *	@err: pointer to an error code return
525  *
526  *	The file handle passed in is locked and the socket it is bound
527  *	to is returned. If an error occurs the err pointer is overwritten
528  *	with a negative errno code and NULL is returned. The function checks
529  *	for both invalid handles and passing a handle which is not a socket.
530  *
531  *	On a success the socket object pointer is returned.
532  */
533 
534 struct socket *sockfd_lookup(int fd, int *err)
535 {
536 	struct file *file;
537 	struct socket *sock;
538 
539 	file = fget(fd);
540 	if (!file) {
541 		*err = -EBADF;
542 		return NULL;
543 	}
544 
545 	sock = sock_from_file(file);
546 	if (!sock) {
547 		*err = -ENOTSOCK;
548 		fput(file);
549 	}
550 	return sock;
551 }
552 EXPORT_SYMBOL(sockfd_lookup);
553 
554 static ssize_t sockfs_listxattr(struct dentry *dentry, char *buffer,
555 				size_t size)
556 {
557 	ssize_t len;
558 	ssize_t used = 0;
559 
560 	len = security_inode_listsecurity(d_inode(dentry), buffer, size);
561 	if (len < 0)
562 		return len;
563 	used += len;
564 	if (buffer) {
565 		if (size < used)
566 			return -ERANGE;
567 		buffer += len;
568 	}
569 
570 	len = (XATTR_NAME_SOCKPROTONAME_LEN + 1);
571 	used += len;
572 	if (buffer) {
573 		if (size < used)
574 			return -ERANGE;
575 		memcpy(buffer, XATTR_NAME_SOCKPROTONAME, len);
576 		buffer += len;
577 	}
578 
579 	return used;
580 }
581 
582 static int sockfs_setattr(struct mnt_idmap *idmap,
583 			  struct dentry *dentry, struct iattr *iattr)
584 {
585 	int err = simple_setattr(&nop_mnt_idmap, dentry, iattr);
586 
587 	if (!err && (iattr->ia_valid & ATTR_UID)) {
588 		struct socket *sock = SOCKET_I(d_inode(dentry));
589 
590 		if (sock->sk)
591 			sock->sk->sk_uid = iattr->ia_uid;
592 		else
593 			err = -ENOENT;
594 	}
595 
596 	return err;
597 }
598 
599 static const struct inode_operations sockfs_inode_ops = {
600 	.listxattr = sockfs_listxattr,
601 	.setattr = sockfs_setattr,
602 };
603 
604 /**
605  *	sock_alloc - allocate a socket
606  *
607  *	Allocate a new inode and socket object. The two are bound together
608  *	and initialised. The socket is then returned. If we are out of inodes
609  *	NULL is returned. This functions uses GFP_KERNEL internally.
610  */
611 
612 struct socket *sock_alloc(void)
613 {
614 	struct inode *inode;
615 	struct socket *sock;
616 
617 	inode = new_inode_pseudo(sock_mnt->mnt_sb);
618 	if (!inode)
619 		return NULL;
620 
621 	sock = SOCKET_I(inode);
622 
623 	inode->i_ino = get_next_ino();
624 	inode->i_mode = S_IFSOCK | S_IRWXUGO;
625 	inode->i_uid = current_fsuid();
626 	inode->i_gid = current_fsgid();
627 	inode->i_op = &sockfs_inode_ops;
628 
629 	return sock;
630 }
631 EXPORT_SYMBOL(sock_alloc);
632 
633 static void __sock_release(struct socket *sock, struct inode *inode)
634 {
635 	const struct proto_ops *ops = READ_ONCE(sock->ops);
636 
637 	if (ops) {
638 		struct module *owner = ops->owner;
639 
640 		if (inode)
641 			inode_lock(inode);
642 		ops->release(sock);
643 		sock->sk = NULL;
644 		if (inode)
645 			inode_unlock(inode);
646 		sock->ops = NULL;
647 		module_put(owner);
648 	}
649 
650 	if (sock->wq.fasync_list)
651 		pr_err("%s: fasync list not empty!\n", __func__);
652 
653 	if (!sock->file) {
654 		iput(SOCK_INODE(sock));
655 		return;
656 	}
657 	sock->file = NULL;
658 }
659 
660 /**
661  *	sock_release - close a socket
662  *	@sock: socket to close
663  *
664  *	The socket is released from the protocol stack if it has a release
665  *	callback, and the inode is then released if the socket is bound to
666  *	an inode not a file.
667  */
668 void sock_release(struct socket *sock)
669 {
670 	__sock_release(sock, NULL);
671 }
672 EXPORT_SYMBOL(sock_release);
673 
674 void __sock_tx_timestamp(__u32 tsflags, __u8 *tx_flags)
675 {
676 	u8 flags = *tx_flags;
677 
678 	if (tsflags & SOF_TIMESTAMPING_TX_HARDWARE) {
679 		flags |= SKBTX_HW_TSTAMP;
680 
681 		/* PTP hardware clocks can provide a free running cycle counter
682 		 * as a time base for virtual clocks. Tell driver to use the
683 		 * free running cycle counter for timestamp if socket is bound
684 		 * to virtual clock.
685 		 */
686 		if (tsflags & SOF_TIMESTAMPING_BIND_PHC)
687 			flags |= SKBTX_HW_TSTAMP_USE_CYCLES;
688 	}
689 
690 	if (tsflags & SOF_TIMESTAMPING_TX_SOFTWARE)
691 		flags |= SKBTX_SW_TSTAMP;
692 
693 	if (tsflags & SOF_TIMESTAMPING_TX_SCHED)
694 		flags |= SKBTX_SCHED_TSTAMP;
695 
696 	*tx_flags = flags;
697 }
698 EXPORT_SYMBOL(__sock_tx_timestamp);
699 
700 INDIRECT_CALLABLE_DECLARE(int inet_sendmsg(struct socket *, struct msghdr *,
701 					   size_t));
702 INDIRECT_CALLABLE_DECLARE(int inet6_sendmsg(struct socket *, struct msghdr *,
703 					    size_t));
704 
705 static noinline void call_trace_sock_send_length(struct sock *sk, int ret,
706 						 int flags)
707 {
708 	trace_sock_send_length(sk, ret, 0);
709 }
710 
711 static inline int sock_sendmsg_nosec(struct socket *sock, struct msghdr *msg)
712 {
713 	int ret = INDIRECT_CALL_INET(READ_ONCE(sock->ops)->sendmsg, inet6_sendmsg,
714 				     inet_sendmsg, sock, msg,
715 				     msg_data_left(msg));
716 	BUG_ON(ret == -EIOCBQUEUED);
717 
718 	if (trace_sock_send_length_enabled())
719 		call_trace_sock_send_length(sock->sk, ret, 0);
720 	return ret;
721 }
722 
723 static int __sock_sendmsg(struct socket *sock, struct msghdr *msg)
724 {
725 	int err = security_socket_sendmsg(sock, msg,
726 					  msg_data_left(msg));
727 
728 	return err ?: sock_sendmsg_nosec(sock, msg);
729 }
730 
731 /**
732  *	sock_sendmsg - send a message through @sock
733  *	@sock: socket
734  *	@msg: message to send
735  *
736  *	Sends @msg through @sock, passing through LSM.
737  *	Returns the number of bytes sent, or an error code.
738  */
739 int sock_sendmsg(struct socket *sock, struct msghdr *msg)
740 {
741 	struct sockaddr_storage *save_addr = (struct sockaddr_storage *)msg->msg_name;
742 	struct sockaddr_storage address;
743 	int save_len = msg->msg_namelen;
744 	int ret;
745 
746 	if (msg->msg_name) {
747 		memcpy(&address, msg->msg_name, msg->msg_namelen);
748 		msg->msg_name = &address;
749 	}
750 
751 	ret = __sock_sendmsg(sock, msg);
752 	msg->msg_name = save_addr;
753 	msg->msg_namelen = save_len;
754 
755 	return ret;
756 }
757 EXPORT_SYMBOL(sock_sendmsg);
758 
759 /**
760  *	kernel_sendmsg - send a message through @sock (kernel-space)
761  *	@sock: socket
762  *	@msg: message header
763  *	@vec: kernel vec
764  *	@num: vec array length
765  *	@size: total message data size
766  *
767  *	Builds the message data with @vec and sends it through @sock.
768  *	Returns the number of bytes sent, or an error code.
769  */
770 
771 int kernel_sendmsg(struct socket *sock, struct msghdr *msg,
772 		   struct kvec *vec, size_t num, size_t size)
773 {
774 	iov_iter_kvec(&msg->msg_iter, ITER_SOURCE, vec, num, size);
775 	return sock_sendmsg(sock, msg);
776 }
777 EXPORT_SYMBOL(kernel_sendmsg);
778 
779 static bool skb_is_err_queue(const struct sk_buff *skb)
780 {
781 	/* pkt_type of skbs enqueued on the error queue are set to
782 	 * PACKET_OUTGOING in skb_set_err_queue(). This is only safe to do
783 	 * in recvmsg, since skbs received on a local socket will never
784 	 * have a pkt_type of PACKET_OUTGOING.
785 	 */
786 	return skb->pkt_type == PACKET_OUTGOING;
787 }
788 
789 /* On transmit, software and hardware timestamps are returned independently.
790  * As the two skb clones share the hardware timestamp, which may be updated
791  * before the software timestamp is received, a hardware TX timestamp may be
792  * returned only if there is no software TX timestamp. Ignore false software
793  * timestamps, which may be made in the __sock_recv_timestamp() call when the
794  * option SO_TIMESTAMP_OLD(NS) is enabled on the socket, even when the skb has a
795  * hardware timestamp.
796  */
797 static bool skb_is_swtx_tstamp(const struct sk_buff *skb, int false_tstamp)
798 {
799 	return skb->tstamp && !false_tstamp && skb_is_err_queue(skb);
800 }
801 
802 static ktime_t get_timestamp(struct sock *sk, struct sk_buff *skb, int *if_index)
803 {
804 	bool cycles = READ_ONCE(sk->sk_tsflags) & SOF_TIMESTAMPING_BIND_PHC;
805 	struct skb_shared_hwtstamps *shhwtstamps = skb_hwtstamps(skb);
806 	struct net_device *orig_dev;
807 	ktime_t hwtstamp;
808 
809 	rcu_read_lock();
810 	orig_dev = dev_get_by_napi_id(skb_napi_id(skb));
811 	if (orig_dev) {
812 		*if_index = orig_dev->ifindex;
813 		hwtstamp = netdev_get_tstamp(orig_dev, shhwtstamps, cycles);
814 	} else {
815 		hwtstamp = shhwtstamps->hwtstamp;
816 	}
817 	rcu_read_unlock();
818 
819 	return hwtstamp;
820 }
821 
822 static void put_ts_pktinfo(struct msghdr *msg, struct sk_buff *skb,
823 			   int if_index)
824 {
825 	struct scm_ts_pktinfo ts_pktinfo;
826 	struct net_device *orig_dev;
827 
828 	if (!skb_mac_header_was_set(skb))
829 		return;
830 
831 	memset(&ts_pktinfo, 0, sizeof(ts_pktinfo));
832 
833 	if (!if_index) {
834 		rcu_read_lock();
835 		orig_dev = dev_get_by_napi_id(skb_napi_id(skb));
836 		if (orig_dev)
837 			if_index = orig_dev->ifindex;
838 		rcu_read_unlock();
839 	}
840 	ts_pktinfo.if_index = if_index;
841 
842 	ts_pktinfo.pkt_length = skb->len - skb_mac_offset(skb);
843 	put_cmsg(msg, SOL_SOCKET, SCM_TIMESTAMPING_PKTINFO,
844 		 sizeof(ts_pktinfo), &ts_pktinfo);
845 }
846 
847 /*
848  * called from sock_recv_timestamp() if sock_flag(sk, SOCK_RCVTSTAMP)
849  */
850 void __sock_recv_timestamp(struct msghdr *msg, struct sock *sk,
851 	struct sk_buff *skb)
852 {
853 	int need_software_tstamp = sock_flag(sk, SOCK_RCVTSTAMP);
854 	int new_tstamp = sock_flag(sk, SOCK_TSTAMP_NEW);
855 	struct scm_timestamping_internal tss;
856 	int empty = 1, false_tstamp = 0;
857 	struct skb_shared_hwtstamps *shhwtstamps =
858 		skb_hwtstamps(skb);
859 	int if_index;
860 	ktime_t hwtstamp;
861 	u32 tsflags;
862 
863 	/* Race occurred between timestamp enabling and packet
864 	   receiving.  Fill in the current time for now. */
865 	if (need_software_tstamp && skb->tstamp == 0) {
866 		__net_timestamp(skb);
867 		false_tstamp = 1;
868 	}
869 
870 	if (need_software_tstamp) {
871 		if (!sock_flag(sk, SOCK_RCVTSTAMPNS)) {
872 			if (new_tstamp) {
873 				struct __kernel_sock_timeval tv;
874 
875 				skb_get_new_timestamp(skb, &tv);
876 				put_cmsg(msg, SOL_SOCKET, SO_TIMESTAMP_NEW,
877 					 sizeof(tv), &tv);
878 			} else {
879 				struct __kernel_old_timeval tv;
880 
881 				skb_get_timestamp(skb, &tv);
882 				put_cmsg(msg, SOL_SOCKET, SO_TIMESTAMP_OLD,
883 					 sizeof(tv), &tv);
884 			}
885 		} else {
886 			if (new_tstamp) {
887 				struct __kernel_timespec ts;
888 
889 				skb_get_new_timestampns(skb, &ts);
890 				put_cmsg(msg, SOL_SOCKET, SO_TIMESTAMPNS_NEW,
891 					 sizeof(ts), &ts);
892 			} else {
893 				struct __kernel_old_timespec ts;
894 
895 				skb_get_timestampns(skb, &ts);
896 				put_cmsg(msg, SOL_SOCKET, SO_TIMESTAMPNS_OLD,
897 					 sizeof(ts), &ts);
898 			}
899 		}
900 	}
901 
902 	memset(&tss, 0, sizeof(tss));
903 	tsflags = READ_ONCE(sk->sk_tsflags);
904 	if ((tsflags & SOF_TIMESTAMPING_SOFTWARE &&
905 	     (tsflags & SOF_TIMESTAMPING_RX_SOFTWARE ||
906 	      skb_is_err_queue(skb) ||
907 	      !(tsflags & SOF_TIMESTAMPING_OPT_RX_FILTER))) &&
908 	    ktime_to_timespec64_cond(skb->tstamp, tss.ts + 0))
909 		empty = 0;
910 	if (shhwtstamps &&
911 	    (tsflags & SOF_TIMESTAMPING_RAW_HARDWARE &&
912 	     (tsflags & SOF_TIMESTAMPING_RX_HARDWARE ||
913 	      skb_is_err_queue(skb) ||
914 	      !(tsflags & SOF_TIMESTAMPING_OPT_RX_FILTER))) &&
915 	    !skb_is_swtx_tstamp(skb, false_tstamp)) {
916 		if_index = 0;
917 		if (skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP_NETDEV)
918 			hwtstamp = get_timestamp(sk, skb, &if_index);
919 		else
920 			hwtstamp = shhwtstamps->hwtstamp;
921 
922 		if (tsflags & SOF_TIMESTAMPING_BIND_PHC)
923 			hwtstamp = ptp_convert_timestamp(&hwtstamp,
924 							 READ_ONCE(sk->sk_bind_phc));
925 
926 		if (ktime_to_timespec64_cond(hwtstamp, tss.ts + 2)) {
927 			empty = 0;
928 
929 			if ((tsflags & SOF_TIMESTAMPING_OPT_PKTINFO) &&
930 			    !skb_is_err_queue(skb))
931 				put_ts_pktinfo(msg, skb, if_index);
932 		}
933 	}
934 	if (!empty) {
935 		if (sock_flag(sk, SOCK_TSTAMP_NEW))
936 			put_cmsg_scm_timestamping64(msg, &tss);
937 		else
938 			put_cmsg_scm_timestamping(msg, &tss);
939 
940 		if (skb_is_err_queue(skb) && skb->len &&
941 		    SKB_EXT_ERR(skb)->opt_stats)
942 			put_cmsg(msg, SOL_SOCKET, SCM_TIMESTAMPING_OPT_STATS,
943 				 skb->len, skb->data);
944 	}
945 }
946 EXPORT_SYMBOL_GPL(__sock_recv_timestamp);
947 
948 #ifdef CONFIG_WIRELESS
949 void __sock_recv_wifi_status(struct msghdr *msg, struct sock *sk,
950 	struct sk_buff *skb)
951 {
952 	int ack;
953 
954 	if (!sock_flag(sk, SOCK_WIFI_STATUS))
955 		return;
956 	if (!skb->wifi_acked_valid)
957 		return;
958 
959 	ack = skb->wifi_acked;
960 
961 	put_cmsg(msg, SOL_SOCKET, SCM_WIFI_STATUS, sizeof(ack), &ack);
962 }
963 EXPORT_SYMBOL_GPL(__sock_recv_wifi_status);
964 #endif
965 
966 static inline void sock_recv_drops(struct msghdr *msg, struct sock *sk,
967 				   struct sk_buff *skb)
968 {
969 	if (sock_flag(sk, SOCK_RXQ_OVFL) && skb && SOCK_SKB_CB(skb)->dropcount)
970 		put_cmsg(msg, SOL_SOCKET, SO_RXQ_OVFL,
971 			sizeof(__u32), &SOCK_SKB_CB(skb)->dropcount);
972 }
973 
974 static void sock_recv_mark(struct msghdr *msg, struct sock *sk,
975 			   struct sk_buff *skb)
976 {
977 	if (sock_flag(sk, SOCK_RCVMARK) && skb) {
978 		/* We must use a bounce buffer for CONFIG_HARDENED_USERCOPY=y */
979 		__u32 mark = skb->mark;
980 
981 		put_cmsg(msg, SOL_SOCKET, SO_MARK, sizeof(__u32), &mark);
982 	}
983 }
984 
985 static void sock_recv_priority(struct msghdr *msg, struct sock *sk,
986 			       struct sk_buff *skb)
987 {
988 	if (sock_flag(sk, SOCK_RCVPRIORITY) && skb) {
989 		__u32 priority = skb->priority;
990 
991 		put_cmsg(msg, SOL_SOCKET, SO_PRIORITY, sizeof(__u32), &priority);
992 	}
993 }
994 
995 void __sock_recv_cmsgs(struct msghdr *msg, struct sock *sk,
996 		       struct sk_buff *skb)
997 {
998 	sock_recv_timestamp(msg, sk, skb);
999 	sock_recv_drops(msg, sk, skb);
1000 	sock_recv_mark(msg, sk, skb);
1001 	sock_recv_priority(msg, sk, skb);
1002 }
1003 EXPORT_SYMBOL_GPL(__sock_recv_cmsgs);
1004 
1005 INDIRECT_CALLABLE_DECLARE(int inet_recvmsg(struct socket *, struct msghdr *,
1006 					   size_t, int));
1007 INDIRECT_CALLABLE_DECLARE(int inet6_recvmsg(struct socket *, struct msghdr *,
1008 					    size_t, int));
1009 
1010 static noinline void call_trace_sock_recv_length(struct sock *sk, int ret, int flags)
1011 {
1012 	trace_sock_recv_length(sk, ret, flags);
1013 }
1014 
1015 static inline int sock_recvmsg_nosec(struct socket *sock, struct msghdr *msg,
1016 				     int flags)
1017 {
1018 	int ret = INDIRECT_CALL_INET(READ_ONCE(sock->ops)->recvmsg,
1019 				     inet6_recvmsg,
1020 				     inet_recvmsg, sock, msg,
1021 				     msg_data_left(msg), flags);
1022 	if (trace_sock_recv_length_enabled())
1023 		call_trace_sock_recv_length(sock->sk, ret, flags);
1024 	return ret;
1025 }
1026 
1027 /**
1028  *	sock_recvmsg - receive a message from @sock
1029  *	@sock: socket
1030  *	@msg: message to receive
1031  *	@flags: message flags
1032  *
1033  *	Receives @msg from @sock, passing through LSM. Returns the total number
1034  *	of bytes received, or an error.
1035  */
1036 int sock_recvmsg(struct socket *sock, struct msghdr *msg, int flags)
1037 {
1038 	int err = security_socket_recvmsg(sock, msg, msg_data_left(msg), flags);
1039 
1040 	return err ?: sock_recvmsg_nosec(sock, msg, flags);
1041 }
1042 EXPORT_SYMBOL(sock_recvmsg);
1043 
1044 /**
1045  *	kernel_recvmsg - Receive a message from a socket (kernel space)
1046  *	@sock: The socket to receive the message from
1047  *	@msg: Received message
1048  *	@vec: Input s/g array for message data
1049  *	@num: Size of input s/g array
1050  *	@size: Number of bytes to read
1051  *	@flags: Message flags (MSG_DONTWAIT, etc...)
1052  *
1053  *	On return the msg structure contains the scatter/gather array passed in the
1054  *	vec argument. The array is modified so that it consists of the unfilled
1055  *	portion of the original array.
1056  *
1057  *	The returned value is the total number of bytes received, or an error.
1058  */
1059 
1060 int kernel_recvmsg(struct socket *sock, struct msghdr *msg,
1061 		   struct kvec *vec, size_t num, size_t size, int flags)
1062 {
1063 	msg->msg_control_is_user = false;
1064 	iov_iter_kvec(&msg->msg_iter, ITER_DEST, vec, num, size);
1065 	return sock_recvmsg(sock, msg, flags);
1066 }
1067 EXPORT_SYMBOL(kernel_recvmsg);
1068 
1069 static ssize_t sock_splice_read(struct file *file, loff_t *ppos,
1070 				struct pipe_inode_info *pipe, size_t len,
1071 				unsigned int flags)
1072 {
1073 	struct socket *sock = file->private_data;
1074 	const struct proto_ops *ops;
1075 
1076 	ops = READ_ONCE(sock->ops);
1077 	if (unlikely(!ops->splice_read))
1078 		return copy_splice_read(file, ppos, pipe, len, flags);
1079 
1080 	return ops->splice_read(sock, ppos, pipe, len, flags);
1081 }
1082 
1083 static void sock_splice_eof(struct file *file)
1084 {
1085 	struct socket *sock = file->private_data;
1086 	const struct proto_ops *ops;
1087 
1088 	ops = READ_ONCE(sock->ops);
1089 	if (ops->splice_eof)
1090 		ops->splice_eof(sock);
1091 }
1092 
1093 static ssize_t sock_read_iter(struct kiocb *iocb, struct iov_iter *to)
1094 {
1095 	struct file *file = iocb->ki_filp;
1096 	struct socket *sock = file->private_data;
1097 	struct msghdr msg = {.msg_iter = *to,
1098 			     .msg_iocb = iocb};
1099 	ssize_t res;
1100 
1101 	if (file->f_flags & O_NONBLOCK || (iocb->ki_flags & IOCB_NOWAIT))
1102 		msg.msg_flags = MSG_DONTWAIT;
1103 
1104 	if (iocb->ki_pos != 0)
1105 		return -ESPIPE;
1106 
1107 	if (!iov_iter_count(to))	/* Match SYS5 behaviour */
1108 		return 0;
1109 
1110 	res = sock_recvmsg(sock, &msg, msg.msg_flags);
1111 	*to = msg.msg_iter;
1112 	return res;
1113 }
1114 
1115 static ssize_t sock_write_iter(struct kiocb *iocb, struct iov_iter *from)
1116 {
1117 	struct file *file = iocb->ki_filp;
1118 	struct socket *sock = file->private_data;
1119 	struct msghdr msg = {.msg_iter = *from,
1120 			     .msg_iocb = iocb};
1121 	ssize_t res;
1122 
1123 	if (iocb->ki_pos != 0)
1124 		return -ESPIPE;
1125 
1126 	if (file->f_flags & O_NONBLOCK || (iocb->ki_flags & IOCB_NOWAIT))
1127 		msg.msg_flags = MSG_DONTWAIT;
1128 
1129 	if (sock->type == SOCK_SEQPACKET)
1130 		msg.msg_flags |= MSG_EOR;
1131 
1132 	res = __sock_sendmsg(sock, &msg);
1133 	*from = msg.msg_iter;
1134 	return res;
1135 }
1136 
1137 /*
1138  * Atomic setting of ioctl hooks to avoid race
1139  * with module unload.
1140  */
1141 
1142 static DEFINE_MUTEX(br_ioctl_mutex);
1143 static int (*br_ioctl_hook)(struct net *net, struct net_bridge *br,
1144 			    unsigned int cmd, struct ifreq *ifr,
1145 			    void __user *uarg);
1146 
1147 void brioctl_set(int (*hook)(struct net *net, struct net_bridge *br,
1148 			     unsigned int cmd, struct ifreq *ifr,
1149 			     void __user *uarg))
1150 {
1151 	mutex_lock(&br_ioctl_mutex);
1152 	br_ioctl_hook = hook;
1153 	mutex_unlock(&br_ioctl_mutex);
1154 }
1155 EXPORT_SYMBOL(brioctl_set);
1156 
1157 int br_ioctl_call(struct net *net, struct net_bridge *br, unsigned int cmd,
1158 		  struct ifreq *ifr, void __user *uarg)
1159 {
1160 	int err = -ENOPKG;
1161 
1162 	if (!br_ioctl_hook)
1163 		request_module("bridge");
1164 
1165 	mutex_lock(&br_ioctl_mutex);
1166 	if (br_ioctl_hook)
1167 		err = br_ioctl_hook(net, br, cmd, ifr, uarg);
1168 	mutex_unlock(&br_ioctl_mutex);
1169 
1170 	return err;
1171 }
1172 
1173 static DEFINE_MUTEX(vlan_ioctl_mutex);
1174 static int (*vlan_ioctl_hook) (struct net *, void __user *arg);
1175 
1176 void vlan_ioctl_set(int (*hook) (struct net *, void __user *))
1177 {
1178 	mutex_lock(&vlan_ioctl_mutex);
1179 	vlan_ioctl_hook = hook;
1180 	mutex_unlock(&vlan_ioctl_mutex);
1181 }
1182 EXPORT_SYMBOL(vlan_ioctl_set);
1183 
1184 static long sock_do_ioctl(struct net *net, struct socket *sock,
1185 			  unsigned int cmd, unsigned long arg)
1186 {
1187 	const struct proto_ops *ops = READ_ONCE(sock->ops);
1188 	struct ifreq ifr;
1189 	bool need_copyout;
1190 	int err;
1191 	void __user *argp = (void __user *)arg;
1192 	void __user *data;
1193 
1194 	err = ops->ioctl(sock, cmd, arg);
1195 
1196 	/*
1197 	 * If this ioctl is unknown try to hand it down
1198 	 * to the NIC driver.
1199 	 */
1200 	if (err != -ENOIOCTLCMD)
1201 		return err;
1202 
1203 	if (!is_socket_ioctl_cmd(cmd))
1204 		return -ENOTTY;
1205 
1206 	if (get_user_ifreq(&ifr, &data, argp))
1207 		return -EFAULT;
1208 	err = dev_ioctl(net, cmd, &ifr, data, &need_copyout);
1209 	if (!err && need_copyout)
1210 		if (put_user_ifreq(&ifr, argp))
1211 			return -EFAULT;
1212 
1213 	return err;
1214 }
1215 
1216 /*
1217  *	With an ioctl, arg may well be a user mode pointer, but we don't know
1218  *	what to do with it - that's up to the protocol still.
1219  */
1220 
1221 static long sock_ioctl(struct file *file, unsigned cmd, unsigned long arg)
1222 {
1223 	const struct proto_ops  *ops;
1224 	struct socket *sock;
1225 	struct sock *sk;
1226 	void __user *argp = (void __user *)arg;
1227 	int pid, err;
1228 	struct net *net;
1229 
1230 	sock = file->private_data;
1231 	ops = READ_ONCE(sock->ops);
1232 	sk = sock->sk;
1233 	net = sock_net(sk);
1234 	if (unlikely(cmd >= SIOCDEVPRIVATE && cmd <= (SIOCDEVPRIVATE + 15))) {
1235 		struct ifreq ifr;
1236 		void __user *data;
1237 		bool need_copyout;
1238 		if (get_user_ifreq(&ifr, &data, argp))
1239 			return -EFAULT;
1240 		err = dev_ioctl(net, cmd, &ifr, data, &need_copyout);
1241 		if (!err && need_copyout)
1242 			if (put_user_ifreq(&ifr, argp))
1243 				return -EFAULT;
1244 	} else
1245 #ifdef CONFIG_WEXT_CORE
1246 	if (cmd >= SIOCIWFIRST && cmd <= SIOCIWLAST) {
1247 		err = wext_handle_ioctl(net, cmd, argp);
1248 	} else
1249 #endif
1250 		switch (cmd) {
1251 		case FIOSETOWN:
1252 		case SIOCSPGRP:
1253 			err = -EFAULT;
1254 			if (get_user(pid, (int __user *)argp))
1255 				break;
1256 			err = f_setown(sock->file, pid, 1);
1257 			break;
1258 		case FIOGETOWN:
1259 		case SIOCGPGRP:
1260 			err = put_user(f_getown(sock->file),
1261 				       (int __user *)argp);
1262 			break;
1263 		case SIOCGIFBR:
1264 		case SIOCSIFBR:
1265 		case SIOCBRADDBR:
1266 		case SIOCBRDELBR:
1267 			err = br_ioctl_call(net, NULL, cmd, NULL, argp);
1268 			break;
1269 		case SIOCGIFVLAN:
1270 		case SIOCSIFVLAN:
1271 			err = -ENOPKG;
1272 			if (!vlan_ioctl_hook)
1273 				request_module("8021q");
1274 
1275 			mutex_lock(&vlan_ioctl_mutex);
1276 			if (vlan_ioctl_hook)
1277 				err = vlan_ioctl_hook(net, argp);
1278 			mutex_unlock(&vlan_ioctl_mutex);
1279 			break;
1280 		case SIOCGSKNS:
1281 			err = -EPERM;
1282 			if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1283 				break;
1284 
1285 			err = open_related_ns(&net->ns, get_net_ns);
1286 			break;
1287 		case SIOCGSTAMP_OLD:
1288 		case SIOCGSTAMPNS_OLD:
1289 			if (!ops->gettstamp) {
1290 				err = -ENOIOCTLCMD;
1291 				break;
1292 			}
1293 			err = ops->gettstamp(sock, argp,
1294 					     cmd == SIOCGSTAMP_OLD,
1295 					     !IS_ENABLED(CONFIG_64BIT));
1296 			break;
1297 		case SIOCGSTAMP_NEW:
1298 		case SIOCGSTAMPNS_NEW:
1299 			if (!ops->gettstamp) {
1300 				err = -ENOIOCTLCMD;
1301 				break;
1302 			}
1303 			err = ops->gettstamp(sock, argp,
1304 					     cmd == SIOCGSTAMP_NEW,
1305 					     false);
1306 			break;
1307 
1308 		case SIOCGIFCONF:
1309 			err = dev_ifconf(net, argp);
1310 			break;
1311 
1312 		default:
1313 			err = sock_do_ioctl(net, sock, cmd, arg);
1314 			break;
1315 		}
1316 	return err;
1317 }
1318 
1319 /**
1320  *	sock_create_lite - creates a socket
1321  *	@family: protocol family (AF_INET, ...)
1322  *	@type: communication type (SOCK_STREAM, ...)
1323  *	@protocol: protocol (0, ...)
1324  *	@res: new socket
1325  *
1326  *	Creates a new socket and assigns it to @res, passing through LSM.
1327  *	The new socket initialization is not complete, see kernel_accept().
1328  *	Returns 0 or an error. On failure @res is set to %NULL.
1329  *	This function internally uses GFP_KERNEL.
1330  */
1331 
1332 int sock_create_lite(int family, int type, int protocol, struct socket **res)
1333 {
1334 	int err;
1335 	struct socket *sock = NULL;
1336 
1337 	err = security_socket_create(family, type, protocol, 1);
1338 	if (err)
1339 		goto out;
1340 
1341 	sock = sock_alloc();
1342 	if (!sock) {
1343 		err = -ENOMEM;
1344 		goto out;
1345 	}
1346 
1347 	sock->type = type;
1348 	err = security_socket_post_create(sock, family, type, protocol, 1);
1349 	if (err)
1350 		goto out_release;
1351 
1352 out:
1353 	*res = sock;
1354 	return err;
1355 out_release:
1356 	sock_release(sock);
1357 	sock = NULL;
1358 	goto out;
1359 }
1360 EXPORT_SYMBOL(sock_create_lite);
1361 
1362 /* No kernel lock held - perfect */
1363 static __poll_t sock_poll(struct file *file, poll_table *wait)
1364 {
1365 	struct socket *sock = file->private_data;
1366 	const struct proto_ops *ops = READ_ONCE(sock->ops);
1367 	__poll_t events = poll_requested_events(wait), flag = 0;
1368 
1369 	if (!ops->poll)
1370 		return 0;
1371 
1372 	if (sk_can_busy_loop(sock->sk)) {
1373 		/* poll once if requested by the syscall */
1374 		if (events & POLL_BUSY_LOOP)
1375 			sk_busy_loop(sock->sk, 1);
1376 
1377 		/* if this socket can poll_ll, tell the system call */
1378 		flag = POLL_BUSY_LOOP;
1379 	}
1380 
1381 	return ops->poll(file, sock, wait) | flag;
1382 }
1383 
1384 static int sock_mmap(struct file *file, struct vm_area_struct *vma)
1385 {
1386 	struct socket *sock = file->private_data;
1387 
1388 	return READ_ONCE(sock->ops)->mmap(file, sock, vma);
1389 }
1390 
1391 static int sock_close(struct inode *inode, struct file *filp)
1392 {
1393 	__sock_release(SOCKET_I(inode), inode);
1394 	return 0;
1395 }
1396 
1397 /*
1398  *	Update the socket async list
1399  *
1400  *	Fasync_list locking strategy.
1401  *
1402  *	1. fasync_list is modified only under process context socket lock
1403  *	   i.e. under semaphore.
1404  *	2. fasync_list is used under read_lock(&sk->sk_callback_lock)
1405  *	   or under socket lock
1406  */
1407 
1408 static int sock_fasync(int fd, struct file *filp, int on)
1409 {
1410 	struct socket *sock = filp->private_data;
1411 	struct sock *sk = sock->sk;
1412 	struct socket_wq *wq = &sock->wq;
1413 
1414 	if (sk == NULL)
1415 		return -EINVAL;
1416 
1417 	lock_sock(sk);
1418 	fasync_helper(fd, filp, on, &wq->fasync_list);
1419 
1420 	if (!wq->fasync_list)
1421 		sock_reset_flag(sk, SOCK_FASYNC);
1422 	else
1423 		sock_set_flag(sk, SOCK_FASYNC);
1424 
1425 	release_sock(sk);
1426 	return 0;
1427 }
1428 
1429 /* This function may be called only under rcu_lock */
1430 
1431 int sock_wake_async(struct socket_wq *wq, int how, int band)
1432 {
1433 	if (!wq || !wq->fasync_list)
1434 		return -1;
1435 
1436 	switch (how) {
1437 	case SOCK_WAKE_WAITD:
1438 		if (test_bit(SOCKWQ_ASYNC_WAITDATA, &wq->flags))
1439 			break;
1440 		goto call_kill;
1441 	case SOCK_WAKE_SPACE:
1442 		if (!test_and_clear_bit(SOCKWQ_ASYNC_NOSPACE, &wq->flags))
1443 			break;
1444 		fallthrough;
1445 	case SOCK_WAKE_IO:
1446 call_kill:
1447 		kill_fasync(&wq->fasync_list, SIGIO, band);
1448 		break;
1449 	case SOCK_WAKE_URG:
1450 		kill_fasync(&wq->fasync_list, SIGURG, band);
1451 	}
1452 
1453 	return 0;
1454 }
1455 EXPORT_SYMBOL(sock_wake_async);
1456 
1457 /**
1458  *	__sock_create - creates a socket
1459  *	@net: net namespace
1460  *	@family: protocol family (AF_INET, ...)
1461  *	@type: communication type (SOCK_STREAM, ...)
1462  *	@protocol: protocol (0, ...)
1463  *	@res: new socket
1464  *	@kern: boolean for kernel space sockets
1465  *
1466  *	Creates a new socket and assigns it to @res, passing through LSM.
1467  *	Returns 0 or an error. On failure @res is set to %NULL. @kern must
1468  *	be set to true if the socket resides in kernel space.
1469  *	This function internally uses GFP_KERNEL.
1470  */
1471 
1472 int __sock_create(struct net *net, int family, int type, int protocol,
1473 			 struct socket **res, int kern)
1474 {
1475 	int err;
1476 	struct socket *sock;
1477 	const struct net_proto_family *pf;
1478 
1479 	/*
1480 	 *      Check protocol is in range
1481 	 */
1482 	if (family < 0 || family >= NPROTO)
1483 		return -EAFNOSUPPORT;
1484 	if (type < 0 || type >= SOCK_MAX)
1485 		return -EINVAL;
1486 
1487 	/* Compatibility.
1488 
1489 	   This uglymoron is moved from INET layer to here to avoid
1490 	   deadlock in module load.
1491 	 */
1492 	if (family == PF_INET && type == SOCK_PACKET) {
1493 		pr_info_once("%s uses obsolete (PF_INET,SOCK_PACKET)\n",
1494 			     current->comm);
1495 		family = PF_PACKET;
1496 	}
1497 
1498 	err = security_socket_create(family, type, protocol, kern);
1499 	if (err)
1500 		return err;
1501 
1502 	/*
1503 	 *	Allocate the socket and allow the family to set things up. if
1504 	 *	the protocol is 0, the family is instructed to select an appropriate
1505 	 *	default.
1506 	 */
1507 	sock = sock_alloc();
1508 	if (!sock) {
1509 		net_warn_ratelimited("socket: no more sockets\n");
1510 		return -ENFILE;	/* Not exactly a match, but its the
1511 				   closest posix thing */
1512 	}
1513 
1514 	sock->type = type;
1515 
1516 #ifdef CONFIG_MODULES
1517 	/* Attempt to load a protocol module if the find failed.
1518 	 *
1519 	 * 12/09/1996 Marcin: But! this makes REALLY only sense, if the user
1520 	 * requested real, full-featured networking support upon configuration.
1521 	 * Otherwise module support will break!
1522 	 */
1523 	if (rcu_access_pointer(net_families[family]) == NULL)
1524 		request_module("net-pf-%d", family);
1525 #endif
1526 
1527 	rcu_read_lock();
1528 	pf = rcu_dereference(net_families[family]);
1529 	err = -EAFNOSUPPORT;
1530 	if (!pf)
1531 		goto out_release;
1532 
1533 	/*
1534 	 * We will call the ->create function, that possibly is in a loadable
1535 	 * module, so we have to bump that loadable module refcnt first.
1536 	 */
1537 	if (!try_module_get(pf->owner))
1538 		goto out_release;
1539 
1540 	/* Now protected by module ref count */
1541 	rcu_read_unlock();
1542 
1543 	err = pf->create(net, sock, protocol, kern);
1544 	if (err < 0) {
1545 		/* ->create should release the allocated sock->sk object on error
1546 		 * and make sure sock->sk is set to NULL to avoid use-after-free
1547 		 */
1548 		DEBUG_NET_WARN_ONCE(sock->sk,
1549 				    "%ps must clear sock->sk on failure, family: %d, type: %d, protocol: %d\n",
1550 				    pf->create, family, type, protocol);
1551 		goto out_module_put;
1552 	}
1553 
1554 	/*
1555 	 * Now to bump the refcnt of the [loadable] module that owns this
1556 	 * socket at sock_release time we decrement its refcnt.
1557 	 */
1558 	if (!try_module_get(sock->ops->owner))
1559 		goto out_module_busy;
1560 
1561 	/*
1562 	 * Now that we're done with the ->create function, the [loadable]
1563 	 * module can have its refcnt decremented
1564 	 */
1565 	module_put(pf->owner);
1566 	err = security_socket_post_create(sock, family, type, protocol, kern);
1567 	if (err)
1568 		goto out_sock_release;
1569 	*res = sock;
1570 
1571 	return 0;
1572 
1573 out_module_busy:
1574 	err = -EAFNOSUPPORT;
1575 out_module_put:
1576 	sock->ops = NULL;
1577 	module_put(pf->owner);
1578 out_sock_release:
1579 	sock_release(sock);
1580 	return err;
1581 
1582 out_release:
1583 	rcu_read_unlock();
1584 	goto out_sock_release;
1585 }
1586 EXPORT_SYMBOL(__sock_create);
1587 
1588 /**
1589  *	sock_create - creates a socket
1590  *	@family: protocol family (AF_INET, ...)
1591  *	@type: communication type (SOCK_STREAM, ...)
1592  *	@protocol: protocol (0, ...)
1593  *	@res: new socket
1594  *
1595  *	A wrapper around __sock_create().
1596  *	Returns 0 or an error. This function internally uses GFP_KERNEL.
1597  */
1598 
1599 int sock_create(int family, int type, int protocol, struct socket **res)
1600 {
1601 	return __sock_create(current->nsproxy->net_ns, family, type, protocol, res, 0);
1602 }
1603 EXPORT_SYMBOL(sock_create);
1604 
1605 /**
1606  *	sock_create_kern - creates a socket (kernel space)
1607  *	@net: net namespace
1608  *	@family: protocol family (AF_INET, ...)
1609  *	@type: communication type (SOCK_STREAM, ...)
1610  *	@protocol: protocol (0, ...)
1611  *	@res: new socket
1612  *
1613  *	A wrapper around __sock_create().
1614  *	Returns 0 or an error. This function internally uses GFP_KERNEL.
1615  */
1616 
1617 int sock_create_kern(struct net *net, int family, int type, int protocol, struct socket **res)
1618 {
1619 	return __sock_create(net, family, type, protocol, res, 1);
1620 }
1621 EXPORT_SYMBOL(sock_create_kern);
1622 
1623 static struct socket *__sys_socket_create(int family, int type, int protocol)
1624 {
1625 	struct socket *sock;
1626 	int retval;
1627 
1628 	/* Check the SOCK_* constants for consistency.  */
1629 	BUILD_BUG_ON(SOCK_CLOEXEC != O_CLOEXEC);
1630 	BUILD_BUG_ON((SOCK_MAX | SOCK_TYPE_MASK) != SOCK_TYPE_MASK);
1631 	BUILD_BUG_ON(SOCK_CLOEXEC & SOCK_TYPE_MASK);
1632 	BUILD_BUG_ON(SOCK_NONBLOCK & SOCK_TYPE_MASK);
1633 
1634 	if ((type & ~SOCK_TYPE_MASK) & ~(SOCK_CLOEXEC | SOCK_NONBLOCK))
1635 		return ERR_PTR(-EINVAL);
1636 	type &= SOCK_TYPE_MASK;
1637 
1638 	retval = sock_create(family, type, protocol, &sock);
1639 	if (retval < 0)
1640 		return ERR_PTR(retval);
1641 
1642 	return sock;
1643 }
1644 
1645 struct file *__sys_socket_file(int family, int type, int protocol)
1646 {
1647 	struct socket *sock;
1648 	int flags;
1649 
1650 	sock = __sys_socket_create(family, type, protocol);
1651 	if (IS_ERR(sock))
1652 		return ERR_CAST(sock);
1653 
1654 	flags = type & ~SOCK_TYPE_MASK;
1655 	if (SOCK_NONBLOCK != O_NONBLOCK && (flags & SOCK_NONBLOCK))
1656 		flags = (flags & ~SOCK_NONBLOCK) | O_NONBLOCK;
1657 
1658 	return sock_alloc_file(sock, flags, NULL);
1659 }
1660 
1661 /*	A hook for bpf progs to attach to and update socket protocol.
1662  *
1663  *	A static noinline declaration here could cause the compiler to
1664  *	optimize away the function. A global noinline declaration will
1665  *	keep the definition, but may optimize away the callsite.
1666  *	Therefore, __weak is needed to ensure that the call is still
1667  *	emitted, by telling the compiler that we don't know what the
1668  *	function might eventually be.
1669  */
1670 
1671 __bpf_hook_start();
1672 
1673 __weak noinline int update_socket_protocol(int family, int type, int protocol)
1674 {
1675 	return protocol;
1676 }
1677 
1678 __bpf_hook_end();
1679 
1680 int __sys_socket(int family, int type, int protocol)
1681 {
1682 	struct socket *sock;
1683 	int flags;
1684 
1685 	sock = __sys_socket_create(family, type,
1686 				   update_socket_protocol(family, type, protocol));
1687 	if (IS_ERR(sock))
1688 		return PTR_ERR(sock);
1689 
1690 	flags = type & ~SOCK_TYPE_MASK;
1691 	if (SOCK_NONBLOCK != O_NONBLOCK && (flags & SOCK_NONBLOCK))
1692 		flags = (flags & ~SOCK_NONBLOCK) | O_NONBLOCK;
1693 
1694 	return sock_map_fd(sock, flags & (O_CLOEXEC | O_NONBLOCK));
1695 }
1696 
1697 SYSCALL_DEFINE3(socket, int, family, int, type, int, protocol)
1698 {
1699 	return __sys_socket(family, type, protocol);
1700 }
1701 
1702 /*
1703  *	Create a pair of connected sockets.
1704  */
1705 
1706 int __sys_socketpair(int family, int type, int protocol, int __user *usockvec)
1707 {
1708 	struct socket *sock1, *sock2;
1709 	int fd1, fd2, err;
1710 	struct file *newfile1, *newfile2;
1711 	int flags;
1712 
1713 	flags = type & ~SOCK_TYPE_MASK;
1714 	if (flags & ~(SOCK_CLOEXEC | SOCK_NONBLOCK))
1715 		return -EINVAL;
1716 	type &= SOCK_TYPE_MASK;
1717 
1718 	if (SOCK_NONBLOCK != O_NONBLOCK && (flags & SOCK_NONBLOCK))
1719 		flags = (flags & ~SOCK_NONBLOCK) | O_NONBLOCK;
1720 
1721 	/*
1722 	 * reserve descriptors and make sure we won't fail
1723 	 * to return them to userland.
1724 	 */
1725 	fd1 = get_unused_fd_flags(flags);
1726 	if (unlikely(fd1 < 0))
1727 		return fd1;
1728 
1729 	fd2 = get_unused_fd_flags(flags);
1730 	if (unlikely(fd2 < 0)) {
1731 		put_unused_fd(fd1);
1732 		return fd2;
1733 	}
1734 
1735 	err = put_user(fd1, &usockvec[0]);
1736 	if (err)
1737 		goto out;
1738 
1739 	err = put_user(fd2, &usockvec[1]);
1740 	if (err)
1741 		goto out;
1742 
1743 	/*
1744 	 * Obtain the first socket and check if the underlying protocol
1745 	 * supports the socketpair call.
1746 	 */
1747 
1748 	err = sock_create(family, type, protocol, &sock1);
1749 	if (unlikely(err < 0))
1750 		goto out;
1751 
1752 	err = sock_create(family, type, protocol, &sock2);
1753 	if (unlikely(err < 0)) {
1754 		sock_release(sock1);
1755 		goto out;
1756 	}
1757 
1758 	err = security_socket_socketpair(sock1, sock2);
1759 	if (unlikely(err)) {
1760 		sock_release(sock2);
1761 		sock_release(sock1);
1762 		goto out;
1763 	}
1764 
1765 	err = READ_ONCE(sock1->ops)->socketpair(sock1, sock2);
1766 	if (unlikely(err < 0)) {
1767 		sock_release(sock2);
1768 		sock_release(sock1);
1769 		goto out;
1770 	}
1771 
1772 	newfile1 = sock_alloc_file(sock1, flags, NULL);
1773 	if (IS_ERR(newfile1)) {
1774 		err = PTR_ERR(newfile1);
1775 		sock_release(sock2);
1776 		goto out;
1777 	}
1778 
1779 	newfile2 = sock_alloc_file(sock2, flags, NULL);
1780 	if (IS_ERR(newfile2)) {
1781 		err = PTR_ERR(newfile2);
1782 		fput(newfile1);
1783 		goto out;
1784 	}
1785 
1786 	audit_fd_pair(fd1, fd2);
1787 
1788 	fd_install(fd1, newfile1);
1789 	fd_install(fd2, newfile2);
1790 	return 0;
1791 
1792 out:
1793 	put_unused_fd(fd2);
1794 	put_unused_fd(fd1);
1795 	return err;
1796 }
1797 
1798 SYSCALL_DEFINE4(socketpair, int, family, int, type, int, protocol,
1799 		int __user *, usockvec)
1800 {
1801 	return __sys_socketpair(family, type, protocol, usockvec);
1802 }
1803 
1804 int __sys_bind_socket(struct socket *sock, struct sockaddr_storage *address,
1805 		      int addrlen)
1806 {
1807 	int err;
1808 
1809 	err = security_socket_bind(sock, (struct sockaddr *)address,
1810 				   addrlen);
1811 	if (!err)
1812 		err = READ_ONCE(sock->ops)->bind(sock,
1813 						 (struct sockaddr *)address,
1814 						 addrlen);
1815 	return err;
1816 }
1817 
1818 /*
1819  *	Bind a name to a socket. Nothing much to do here since it's
1820  *	the protocol's responsibility to handle the local address.
1821  *
1822  *	We move the socket address to kernel space before we call
1823  *	the protocol layer (having also checked the address is ok).
1824  */
1825 
1826 int __sys_bind(int fd, struct sockaddr __user *umyaddr, int addrlen)
1827 {
1828 	struct socket *sock;
1829 	struct sockaddr_storage address;
1830 	CLASS(fd, f)(fd);
1831 	int err;
1832 
1833 	if (fd_empty(f))
1834 		return -EBADF;
1835 	sock = sock_from_file(fd_file(f));
1836 	if (unlikely(!sock))
1837 		return -ENOTSOCK;
1838 
1839 	err = move_addr_to_kernel(umyaddr, addrlen, &address);
1840 	if (unlikely(err))
1841 		return err;
1842 
1843 	return __sys_bind_socket(sock, &address, addrlen);
1844 }
1845 
1846 SYSCALL_DEFINE3(bind, int, fd, struct sockaddr __user *, umyaddr, int, addrlen)
1847 {
1848 	return __sys_bind(fd, umyaddr, addrlen);
1849 }
1850 
1851 /*
1852  *	Perform a listen. Basically, we allow the protocol to do anything
1853  *	necessary for a listen, and if that works, we mark the socket as
1854  *	ready for listening.
1855  */
1856 int __sys_listen_socket(struct socket *sock, int backlog)
1857 {
1858 	int somaxconn, err;
1859 
1860 	somaxconn = READ_ONCE(sock_net(sock->sk)->core.sysctl_somaxconn);
1861 	if ((unsigned int)backlog > somaxconn)
1862 		backlog = somaxconn;
1863 
1864 	err = security_socket_listen(sock, backlog);
1865 	if (!err)
1866 		err = READ_ONCE(sock->ops)->listen(sock, backlog);
1867 	return err;
1868 }
1869 
1870 int __sys_listen(int fd, int backlog)
1871 {
1872 	CLASS(fd, f)(fd);
1873 	struct socket *sock;
1874 
1875 	if (fd_empty(f))
1876 		return -EBADF;
1877 	sock = sock_from_file(fd_file(f));
1878 	if (unlikely(!sock))
1879 		return -ENOTSOCK;
1880 
1881 	return __sys_listen_socket(sock, backlog);
1882 }
1883 
1884 SYSCALL_DEFINE2(listen, int, fd, int, backlog)
1885 {
1886 	return __sys_listen(fd, backlog);
1887 }
1888 
1889 struct file *do_accept(struct file *file, struct proto_accept_arg *arg,
1890 		       struct sockaddr __user *upeer_sockaddr,
1891 		       int __user *upeer_addrlen, int flags)
1892 {
1893 	struct socket *sock, *newsock;
1894 	struct file *newfile;
1895 	int err, len;
1896 	struct sockaddr_storage address;
1897 	const struct proto_ops *ops;
1898 
1899 	sock = sock_from_file(file);
1900 	if (!sock)
1901 		return ERR_PTR(-ENOTSOCK);
1902 
1903 	newsock = sock_alloc();
1904 	if (!newsock)
1905 		return ERR_PTR(-ENFILE);
1906 	ops = READ_ONCE(sock->ops);
1907 
1908 	newsock->type = sock->type;
1909 	newsock->ops = ops;
1910 
1911 	/*
1912 	 * We don't need try_module_get here, as the listening socket (sock)
1913 	 * has the protocol module (sock->ops->owner) held.
1914 	 */
1915 	__module_get(ops->owner);
1916 
1917 	newfile = sock_alloc_file(newsock, flags, sock->sk->sk_prot_creator->name);
1918 	if (IS_ERR(newfile))
1919 		return newfile;
1920 
1921 	err = security_socket_accept(sock, newsock);
1922 	if (err)
1923 		goto out_fd;
1924 
1925 	arg->flags |= sock->file->f_flags;
1926 	err = ops->accept(sock, newsock, arg);
1927 	if (err < 0)
1928 		goto out_fd;
1929 
1930 	if (upeer_sockaddr) {
1931 		len = ops->getname(newsock, (struct sockaddr *)&address, 2);
1932 		if (len < 0) {
1933 			err = -ECONNABORTED;
1934 			goto out_fd;
1935 		}
1936 		err = move_addr_to_user(&address,
1937 					len, upeer_sockaddr, upeer_addrlen);
1938 		if (err < 0)
1939 			goto out_fd;
1940 	}
1941 
1942 	/* File flags are not inherited via accept() unlike another OSes. */
1943 	return newfile;
1944 out_fd:
1945 	fput(newfile);
1946 	return ERR_PTR(err);
1947 }
1948 
1949 static int __sys_accept4_file(struct file *file, struct sockaddr __user *upeer_sockaddr,
1950 			      int __user *upeer_addrlen, int flags)
1951 {
1952 	struct proto_accept_arg arg = { };
1953 	struct file *newfile;
1954 	int newfd;
1955 
1956 	if (flags & ~(SOCK_CLOEXEC | SOCK_NONBLOCK))
1957 		return -EINVAL;
1958 
1959 	if (SOCK_NONBLOCK != O_NONBLOCK && (flags & SOCK_NONBLOCK))
1960 		flags = (flags & ~SOCK_NONBLOCK) | O_NONBLOCK;
1961 
1962 	newfd = get_unused_fd_flags(flags);
1963 	if (unlikely(newfd < 0))
1964 		return newfd;
1965 
1966 	newfile = do_accept(file, &arg, upeer_sockaddr, upeer_addrlen,
1967 			    flags);
1968 	if (IS_ERR(newfile)) {
1969 		put_unused_fd(newfd);
1970 		return PTR_ERR(newfile);
1971 	}
1972 	fd_install(newfd, newfile);
1973 	return newfd;
1974 }
1975 
1976 /*
1977  *	For accept, we attempt to create a new socket, set up the link
1978  *	with the client, wake up the client, then return the new
1979  *	connected fd. We collect the address of the connector in kernel
1980  *	space and move it to user at the very end. This is unclean because
1981  *	we open the socket then return an error.
1982  *
1983  *	1003.1g adds the ability to recvmsg() to query connection pending
1984  *	status to recvmsg. We need to add that support in a way thats
1985  *	clean when we restructure accept also.
1986  */
1987 
1988 int __sys_accept4(int fd, struct sockaddr __user *upeer_sockaddr,
1989 		  int __user *upeer_addrlen, int flags)
1990 {
1991 	CLASS(fd, f)(fd);
1992 
1993 	if (fd_empty(f))
1994 		return -EBADF;
1995 	return __sys_accept4_file(fd_file(f), upeer_sockaddr,
1996 					 upeer_addrlen, flags);
1997 }
1998 
1999 SYSCALL_DEFINE4(accept4, int, fd, struct sockaddr __user *, upeer_sockaddr,
2000 		int __user *, upeer_addrlen, int, flags)
2001 {
2002 	return __sys_accept4(fd, upeer_sockaddr, upeer_addrlen, flags);
2003 }
2004 
2005 SYSCALL_DEFINE3(accept, int, fd, struct sockaddr __user *, upeer_sockaddr,
2006 		int __user *, upeer_addrlen)
2007 {
2008 	return __sys_accept4(fd, upeer_sockaddr, upeer_addrlen, 0);
2009 }
2010 
2011 /*
2012  *	Attempt to connect to a socket with the server address.  The address
2013  *	is in user space so we verify it is OK and move it to kernel space.
2014  *
2015  *	For 1003.1g we need to add clean support for a bind to AF_UNSPEC to
2016  *	break bindings
2017  *
2018  *	NOTE: 1003.1g draft 6.3 is broken with respect to AX.25/NetROM and
2019  *	other SEQPACKET protocols that take time to connect() as it doesn't
2020  *	include the -EINPROGRESS status for such sockets.
2021  */
2022 
2023 int __sys_connect_file(struct file *file, struct sockaddr_storage *address,
2024 		       int addrlen, int file_flags)
2025 {
2026 	struct socket *sock;
2027 	int err;
2028 
2029 	sock = sock_from_file(file);
2030 	if (!sock) {
2031 		err = -ENOTSOCK;
2032 		goto out;
2033 	}
2034 
2035 	err =
2036 	    security_socket_connect(sock, (struct sockaddr *)address, addrlen);
2037 	if (err)
2038 		goto out;
2039 
2040 	err = READ_ONCE(sock->ops)->connect(sock, (struct sockaddr *)address,
2041 				addrlen, sock->file->f_flags | file_flags);
2042 out:
2043 	return err;
2044 }
2045 
2046 int __sys_connect(int fd, struct sockaddr __user *uservaddr, int addrlen)
2047 {
2048 	struct sockaddr_storage address;
2049 	CLASS(fd, f)(fd);
2050 	int ret;
2051 
2052 	if (fd_empty(f))
2053 		return -EBADF;
2054 
2055 	ret = move_addr_to_kernel(uservaddr, addrlen, &address);
2056 	if (ret)
2057 		return ret;
2058 
2059 	return __sys_connect_file(fd_file(f), &address, addrlen, 0);
2060 }
2061 
2062 SYSCALL_DEFINE3(connect, int, fd, struct sockaddr __user *, uservaddr,
2063 		int, addrlen)
2064 {
2065 	return __sys_connect(fd, uservaddr, addrlen);
2066 }
2067 
2068 /*
2069  *	Get the local address ('name') of a socket object. Move the obtained
2070  *	name to user space.
2071  */
2072 
2073 int __sys_getsockname(int fd, struct sockaddr __user *usockaddr,
2074 		      int __user *usockaddr_len)
2075 {
2076 	struct socket *sock;
2077 	struct sockaddr_storage address;
2078 	CLASS(fd, f)(fd);
2079 	int err;
2080 
2081 	if (fd_empty(f))
2082 		return -EBADF;
2083 	sock = sock_from_file(fd_file(f));
2084 	if (unlikely(!sock))
2085 		return -ENOTSOCK;
2086 
2087 	err = security_socket_getsockname(sock);
2088 	if (err)
2089 		return err;
2090 
2091 	err = READ_ONCE(sock->ops)->getname(sock, (struct sockaddr *)&address, 0);
2092 	if (err < 0)
2093 		return err;
2094 
2095 	/* "err" is actually length in this case */
2096 	return move_addr_to_user(&address, err, usockaddr, usockaddr_len);
2097 }
2098 
2099 SYSCALL_DEFINE3(getsockname, int, fd, struct sockaddr __user *, usockaddr,
2100 		int __user *, usockaddr_len)
2101 {
2102 	return __sys_getsockname(fd, usockaddr, usockaddr_len);
2103 }
2104 
2105 /*
2106  *	Get the remote address ('name') of a socket object. Move the obtained
2107  *	name to user space.
2108  */
2109 
2110 int __sys_getpeername(int fd, struct sockaddr __user *usockaddr,
2111 		      int __user *usockaddr_len)
2112 {
2113 	struct socket *sock;
2114 	struct sockaddr_storage address;
2115 	CLASS(fd, f)(fd);
2116 	int err;
2117 
2118 	if (fd_empty(f))
2119 		return -EBADF;
2120 	sock = sock_from_file(fd_file(f));
2121 	if (unlikely(!sock))
2122 		return -ENOTSOCK;
2123 
2124 	err = security_socket_getpeername(sock);
2125 	if (err)
2126 		return err;
2127 
2128 	err = READ_ONCE(sock->ops)->getname(sock, (struct sockaddr *)&address, 1);
2129 	if (err < 0)
2130 		return err;
2131 
2132 	/* "err" is actually length in this case */
2133 	return move_addr_to_user(&address, err, usockaddr, usockaddr_len);
2134 }
2135 
2136 SYSCALL_DEFINE3(getpeername, int, fd, struct sockaddr __user *, usockaddr,
2137 		int __user *, usockaddr_len)
2138 {
2139 	return __sys_getpeername(fd, usockaddr, usockaddr_len);
2140 }
2141 
2142 /*
2143  *	Send a datagram to a given address. We move the address into kernel
2144  *	space and check the user space data area is readable before invoking
2145  *	the protocol.
2146  */
2147 int __sys_sendto(int fd, void __user *buff, size_t len, unsigned int flags,
2148 		 struct sockaddr __user *addr,  int addr_len)
2149 {
2150 	struct socket *sock;
2151 	struct sockaddr_storage address;
2152 	int err;
2153 	struct msghdr msg;
2154 
2155 	err = import_ubuf(ITER_SOURCE, buff, len, &msg.msg_iter);
2156 	if (unlikely(err))
2157 		return err;
2158 
2159 	CLASS(fd, f)(fd);
2160 	if (fd_empty(f))
2161 		return -EBADF;
2162 	sock = sock_from_file(fd_file(f));
2163 	if (unlikely(!sock))
2164 		return -ENOTSOCK;
2165 
2166 	msg.msg_name = NULL;
2167 	msg.msg_control = NULL;
2168 	msg.msg_controllen = 0;
2169 	msg.msg_namelen = 0;
2170 	msg.msg_ubuf = NULL;
2171 	if (addr) {
2172 		err = move_addr_to_kernel(addr, addr_len, &address);
2173 		if (err < 0)
2174 			return err;
2175 		msg.msg_name = (struct sockaddr *)&address;
2176 		msg.msg_namelen = addr_len;
2177 	}
2178 	flags &= ~MSG_INTERNAL_SENDMSG_FLAGS;
2179 	if (sock->file->f_flags & O_NONBLOCK)
2180 		flags |= MSG_DONTWAIT;
2181 	msg.msg_flags = flags;
2182 	return __sock_sendmsg(sock, &msg);
2183 }
2184 
2185 SYSCALL_DEFINE6(sendto, int, fd, void __user *, buff, size_t, len,
2186 		unsigned int, flags, struct sockaddr __user *, addr,
2187 		int, addr_len)
2188 {
2189 	return __sys_sendto(fd, buff, len, flags, addr, addr_len);
2190 }
2191 
2192 /*
2193  *	Send a datagram down a socket.
2194  */
2195 
2196 SYSCALL_DEFINE4(send, int, fd, void __user *, buff, size_t, len,
2197 		unsigned int, flags)
2198 {
2199 	return __sys_sendto(fd, buff, len, flags, NULL, 0);
2200 }
2201 
2202 /*
2203  *	Receive a frame from the socket and optionally record the address of the
2204  *	sender. We verify the buffers are writable and if needed move the
2205  *	sender address from kernel to user space.
2206  */
2207 int __sys_recvfrom(int fd, void __user *ubuf, size_t size, unsigned int flags,
2208 		   struct sockaddr __user *addr, int __user *addr_len)
2209 {
2210 	struct sockaddr_storage address;
2211 	struct msghdr msg = {
2212 		/* Save some cycles and don't copy the address if not needed */
2213 		.msg_name = addr ? (struct sockaddr *)&address : NULL,
2214 	};
2215 	struct socket *sock;
2216 	int err, err2;
2217 
2218 	err = import_ubuf(ITER_DEST, ubuf, size, &msg.msg_iter);
2219 	if (unlikely(err))
2220 		return err;
2221 
2222 	CLASS(fd, f)(fd);
2223 
2224 	if (fd_empty(f))
2225 		return -EBADF;
2226 	sock = sock_from_file(fd_file(f));
2227 	if (unlikely(!sock))
2228 		return -ENOTSOCK;
2229 
2230 	if (sock->file->f_flags & O_NONBLOCK)
2231 		flags |= MSG_DONTWAIT;
2232 	err = sock_recvmsg(sock, &msg, flags);
2233 
2234 	if (err >= 0 && addr != NULL) {
2235 		err2 = move_addr_to_user(&address,
2236 					 msg.msg_namelen, addr, addr_len);
2237 		if (err2 < 0)
2238 			err = err2;
2239 	}
2240 	return err;
2241 }
2242 
2243 SYSCALL_DEFINE6(recvfrom, int, fd, void __user *, ubuf, size_t, size,
2244 		unsigned int, flags, struct sockaddr __user *, addr,
2245 		int __user *, addr_len)
2246 {
2247 	return __sys_recvfrom(fd, ubuf, size, flags, addr, addr_len);
2248 }
2249 
2250 /*
2251  *	Receive a datagram from a socket.
2252  */
2253 
2254 SYSCALL_DEFINE4(recv, int, fd, void __user *, ubuf, size_t, size,
2255 		unsigned int, flags)
2256 {
2257 	return __sys_recvfrom(fd, ubuf, size, flags, NULL, NULL);
2258 }
2259 
2260 static bool sock_use_custom_sol_socket(const struct socket *sock)
2261 {
2262 	return test_bit(SOCK_CUSTOM_SOCKOPT, &sock->flags);
2263 }
2264 
2265 int do_sock_setsockopt(struct socket *sock, bool compat, int level,
2266 		       int optname, sockptr_t optval, int optlen)
2267 {
2268 	const struct proto_ops *ops;
2269 	char *kernel_optval = NULL;
2270 	int err;
2271 
2272 	if (optlen < 0)
2273 		return -EINVAL;
2274 
2275 	err = security_socket_setsockopt(sock, level, optname);
2276 	if (err)
2277 		goto out_put;
2278 
2279 	if (!compat)
2280 		err = BPF_CGROUP_RUN_PROG_SETSOCKOPT(sock->sk, &level, &optname,
2281 						     optval, &optlen,
2282 						     &kernel_optval);
2283 	if (err < 0)
2284 		goto out_put;
2285 	if (err > 0) {
2286 		err = 0;
2287 		goto out_put;
2288 	}
2289 
2290 	if (kernel_optval)
2291 		optval = KERNEL_SOCKPTR(kernel_optval);
2292 	ops = READ_ONCE(sock->ops);
2293 	if (level == SOL_SOCKET && !sock_use_custom_sol_socket(sock))
2294 		err = sock_setsockopt(sock, level, optname, optval, optlen);
2295 	else if (unlikely(!ops->setsockopt))
2296 		err = -EOPNOTSUPP;
2297 	else
2298 		err = ops->setsockopt(sock, level, optname, optval,
2299 					    optlen);
2300 	kfree(kernel_optval);
2301 out_put:
2302 	return err;
2303 }
2304 EXPORT_SYMBOL(do_sock_setsockopt);
2305 
2306 /* Set a socket option. Because we don't know the option lengths we have
2307  * to pass the user mode parameter for the protocols to sort out.
2308  */
2309 int __sys_setsockopt(int fd, int level, int optname, char __user *user_optval,
2310 		     int optlen)
2311 {
2312 	sockptr_t optval = USER_SOCKPTR(user_optval);
2313 	bool compat = in_compat_syscall();
2314 	struct socket *sock;
2315 	CLASS(fd, f)(fd);
2316 
2317 	if (fd_empty(f))
2318 		return -EBADF;
2319 	sock = sock_from_file(fd_file(f));
2320 	if (unlikely(!sock))
2321 		return -ENOTSOCK;
2322 
2323 	return do_sock_setsockopt(sock, compat, level, optname, optval, optlen);
2324 }
2325 
2326 SYSCALL_DEFINE5(setsockopt, int, fd, int, level, int, optname,
2327 		char __user *, optval, int, optlen)
2328 {
2329 	return __sys_setsockopt(fd, level, optname, optval, optlen);
2330 }
2331 
2332 INDIRECT_CALLABLE_DECLARE(bool tcp_bpf_bypass_getsockopt(int level,
2333 							 int optname));
2334 
2335 int do_sock_getsockopt(struct socket *sock, bool compat, int level,
2336 		       int optname, sockptr_t optval, sockptr_t optlen)
2337 {
2338 	int max_optlen __maybe_unused = 0;
2339 	const struct proto_ops *ops;
2340 	int err;
2341 
2342 	err = security_socket_getsockopt(sock, level, optname);
2343 	if (err)
2344 		return err;
2345 
2346 	if (!compat)
2347 		copy_from_sockptr(&max_optlen, optlen, sizeof(int));
2348 
2349 	ops = READ_ONCE(sock->ops);
2350 	if (level == SOL_SOCKET) {
2351 		err = sk_getsockopt(sock->sk, level, optname, optval, optlen);
2352 	} else if (unlikely(!ops->getsockopt)) {
2353 		err = -EOPNOTSUPP;
2354 	} else {
2355 		if (WARN_ONCE(optval.is_kernel || optlen.is_kernel,
2356 			      "Invalid argument type"))
2357 			return -EOPNOTSUPP;
2358 
2359 		err = ops->getsockopt(sock, level, optname, optval.user,
2360 				      optlen.user);
2361 	}
2362 
2363 	if (!compat)
2364 		err = BPF_CGROUP_RUN_PROG_GETSOCKOPT(sock->sk, level, optname,
2365 						     optval, optlen, max_optlen,
2366 						     err);
2367 
2368 	return err;
2369 }
2370 EXPORT_SYMBOL(do_sock_getsockopt);
2371 
2372 /*
2373  *	Get a socket option. Because we don't know the option lengths we have
2374  *	to pass a user mode parameter for the protocols to sort out.
2375  */
2376 int __sys_getsockopt(int fd, int level, int optname, char __user *optval,
2377 		int __user *optlen)
2378 {
2379 	struct socket *sock;
2380 	CLASS(fd, f)(fd);
2381 
2382 	if (fd_empty(f))
2383 		return -EBADF;
2384 	sock = sock_from_file(fd_file(f));
2385 	if (unlikely(!sock))
2386 		return -ENOTSOCK;
2387 
2388 	return do_sock_getsockopt(sock, in_compat_syscall(), level, optname,
2389 				 USER_SOCKPTR(optval), USER_SOCKPTR(optlen));
2390 }
2391 
2392 SYSCALL_DEFINE5(getsockopt, int, fd, int, level, int, optname,
2393 		char __user *, optval, int __user *, optlen)
2394 {
2395 	return __sys_getsockopt(fd, level, optname, optval, optlen);
2396 }
2397 
2398 /*
2399  *	Shutdown a socket.
2400  */
2401 
2402 int __sys_shutdown_sock(struct socket *sock, int how)
2403 {
2404 	int err;
2405 
2406 	err = security_socket_shutdown(sock, how);
2407 	if (!err)
2408 		err = READ_ONCE(sock->ops)->shutdown(sock, how);
2409 
2410 	return err;
2411 }
2412 
2413 int __sys_shutdown(int fd, int how)
2414 {
2415 	struct socket *sock;
2416 	CLASS(fd, f)(fd);
2417 
2418 	if (fd_empty(f))
2419 		return -EBADF;
2420 	sock = sock_from_file(fd_file(f));
2421 	if (unlikely(!sock))
2422 		return -ENOTSOCK;
2423 
2424 	return __sys_shutdown_sock(sock, how);
2425 }
2426 
2427 SYSCALL_DEFINE2(shutdown, int, fd, int, how)
2428 {
2429 	return __sys_shutdown(fd, how);
2430 }
2431 
2432 /* A couple of helpful macros for getting the address of the 32/64 bit
2433  * fields which are the same type (int / unsigned) on our platforms.
2434  */
2435 #define COMPAT_MSG(msg, member)	((MSG_CMSG_COMPAT & flags) ? &msg##_compat->member : &msg->member)
2436 #define COMPAT_NAMELEN(msg)	COMPAT_MSG(msg, msg_namelen)
2437 #define COMPAT_FLAGS(msg)	COMPAT_MSG(msg, msg_flags)
2438 
2439 struct used_address {
2440 	struct sockaddr_storage name;
2441 	unsigned int name_len;
2442 };
2443 
2444 int __copy_msghdr(struct msghdr *kmsg,
2445 		  struct user_msghdr *msg,
2446 		  struct sockaddr __user **save_addr)
2447 {
2448 	ssize_t err;
2449 
2450 	kmsg->msg_control_is_user = true;
2451 	kmsg->msg_get_inq = 0;
2452 	kmsg->msg_control_user = msg->msg_control;
2453 	kmsg->msg_controllen = msg->msg_controllen;
2454 	kmsg->msg_flags = msg->msg_flags;
2455 
2456 	kmsg->msg_namelen = msg->msg_namelen;
2457 	if (!msg->msg_name)
2458 		kmsg->msg_namelen = 0;
2459 
2460 	if (kmsg->msg_namelen < 0)
2461 		return -EINVAL;
2462 
2463 	if (kmsg->msg_namelen > sizeof(struct sockaddr_storage))
2464 		kmsg->msg_namelen = sizeof(struct sockaddr_storage);
2465 
2466 	if (save_addr)
2467 		*save_addr = msg->msg_name;
2468 
2469 	if (msg->msg_name && kmsg->msg_namelen) {
2470 		if (!save_addr) {
2471 			err = move_addr_to_kernel(msg->msg_name,
2472 						  kmsg->msg_namelen,
2473 						  kmsg->msg_name);
2474 			if (err < 0)
2475 				return err;
2476 		}
2477 	} else {
2478 		kmsg->msg_name = NULL;
2479 		kmsg->msg_namelen = 0;
2480 	}
2481 
2482 	if (msg->msg_iovlen > UIO_MAXIOV)
2483 		return -EMSGSIZE;
2484 
2485 	kmsg->msg_iocb = NULL;
2486 	kmsg->msg_ubuf = NULL;
2487 	return 0;
2488 }
2489 
2490 static int copy_msghdr_from_user(struct msghdr *kmsg,
2491 				 struct user_msghdr __user *umsg,
2492 				 struct sockaddr __user **save_addr,
2493 				 struct iovec **iov)
2494 {
2495 	struct user_msghdr msg;
2496 	ssize_t err;
2497 
2498 	if (copy_from_user(&msg, umsg, sizeof(*umsg)))
2499 		return -EFAULT;
2500 
2501 	err = __copy_msghdr(kmsg, &msg, save_addr);
2502 	if (err)
2503 		return err;
2504 
2505 	err = import_iovec(save_addr ? ITER_DEST : ITER_SOURCE,
2506 			    msg.msg_iov, msg.msg_iovlen,
2507 			    UIO_FASTIOV, iov, &kmsg->msg_iter);
2508 	return err < 0 ? err : 0;
2509 }
2510 
2511 static int ____sys_sendmsg(struct socket *sock, struct msghdr *msg_sys,
2512 			   unsigned int flags, struct used_address *used_address,
2513 			   unsigned int allowed_msghdr_flags)
2514 {
2515 	unsigned char ctl[sizeof(struct cmsghdr) + 20]
2516 				__aligned(sizeof(__kernel_size_t));
2517 	/* 20 is size of ipv6_pktinfo */
2518 	unsigned char *ctl_buf = ctl;
2519 	int ctl_len;
2520 	ssize_t err;
2521 
2522 	err = -ENOBUFS;
2523 
2524 	if (msg_sys->msg_controllen > INT_MAX)
2525 		goto out;
2526 	flags |= (msg_sys->msg_flags & allowed_msghdr_flags);
2527 	ctl_len = msg_sys->msg_controllen;
2528 	if ((MSG_CMSG_COMPAT & flags) && ctl_len) {
2529 		err =
2530 		    cmsghdr_from_user_compat_to_kern(msg_sys, sock->sk, ctl,
2531 						     sizeof(ctl));
2532 		if (err)
2533 			goto out;
2534 		ctl_buf = msg_sys->msg_control;
2535 		ctl_len = msg_sys->msg_controllen;
2536 	} else if (ctl_len) {
2537 		BUILD_BUG_ON(sizeof(struct cmsghdr) !=
2538 			     CMSG_ALIGN(sizeof(struct cmsghdr)));
2539 		if (ctl_len > sizeof(ctl)) {
2540 			ctl_buf = sock_kmalloc(sock->sk, ctl_len, GFP_KERNEL);
2541 			if (ctl_buf == NULL)
2542 				goto out;
2543 		}
2544 		err = -EFAULT;
2545 		if (copy_from_user(ctl_buf, msg_sys->msg_control_user, ctl_len))
2546 			goto out_freectl;
2547 		msg_sys->msg_control = ctl_buf;
2548 		msg_sys->msg_control_is_user = false;
2549 	}
2550 	flags &= ~MSG_INTERNAL_SENDMSG_FLAGS;
2551 	msg_sys->msg_flags = flags;
2552 
2553 	if (sock->file->f_flags & O_NONBLOCK)
2554 		msg_sys->msg_flags |= MSG_DONTWAIT;
2555 	/*
2556 	 * If this is sendmmsg() and current destination address is same as
2557 	 * previously succeeded address, omit asking LSM's decision.
2558 	 * used_address->name_len is initialized to UINT_MAX so that the first
2559 	 * destination address never matches.
2560 	 */
2561 	if (used_address && msg_sys->msg_name &&
2562 	    used_address->name_len == msg_sys->msg_namelen &&
2563 	    !memcmp(&used_address->name, msg_sys->msg_name,
2564 		    used_address->name_len)) {
2565 		err = sock_sendmsg_nosec(sock, msg_sys);
2566 		goto out_freectl;
2567 	}
2568 	err = __sock_sendmsg(sock, msg_sys);
2569 	/*
2570 	 * If this is sendmmsg() and sending to current destination address was
2571 	 * successful, remember it.
2572 	 */
2573 	if (used_address && err >= 0) {
2574 		used_address->name_len = msg_sys->msg_namelen;
2575 		if (msg_sys->msg_name)
2576 			memcpy(&used_address->name, msg_sys->msg_name,
2577 			       used_address->name_len);
2578 	}
2579 
2580 out_freectl:
2581 	if (ctl_buf != ctl)
2582 		sock_kfree_s(sock->sk, ctl_buf, ctl_len);
2583 out:
2584 	return err;
2585 }
2586 
2587 static int sendmsg_copy_msghdr(struct msghdr *msg,
2588 			       struct user_msghdr __user *umsg, unsigned flags,
2589 			       struct iovec **iov)
2590 {
2591 	int err;
2592 
2593 	if (flags & MSG_CMSG_COMPAT) {
2594 		struct compat_msghdr __user *msg_compat;
2595 
2596 		msg_compat = (struct compat_msghdr __user *) umsg;
2597 		err = get_compat_msghdr(msg, msg_compat, NULL, iov);
2598 	} else {
2599 		err = copy_msghdr_from_user(msg, umsg, NULL, iov);
2600 	}
2601 	if (err < 0)
2602 		return err;
2603 
2604 	return 0;
2605 }
2606 
2607 static int ___sys_sendmsg(struct socket *sock, struct user_msghdr __user *msg,
2608 			 struct msghdr *msg_sys, unsigned int flags,
2609 			 struct used_address *used_address,
2610 			 unsigned int allowed_msghdr_flags)
2611 {
2612 	struct sockaddr_storage address;
2613 	struct iovec iovstack[UIO_FASTIOV], *iov = iovstack;
2614 	ssize_t err;
2615 
2616 	msg_sys->msg_name = &address;
2617 
2618 	err = sendmsg_copy_msghdr(msg_sys, msg, flags, &iov);
2619 	if (err < 0)
2620 		return err;
2621 
2622 	err = ____sys_sendmsg(sock, msg_sys, flags, used_address,
2623 				allowed_msghdr_flags);
2624 	kfree(iov);
2625 	return err;
2626 }
2627 
2628 /*
2629  *	BSD sendmsg interface
2630  */
2631 long __sys_sendmsg_sock(struct socket *sock, struct msghdr *msg,
2632 			unsigned int flags)
2633 {
2634 	return ____sys_sendmsg(sock, msg, flags, NULL, 0);
2635 }
2636 
2637 long __sys_sendmsg(int fd, struct user_msghdr __user *msg, unsigned int flags,
2638 		   bool forbid_cmsg_compat)
2639 {
2640 	struct msghdr msg_sys;
2641 	struct socket *sock;
2642 
2643 	if (forbid_cmsg_compat && (flags & MSG_CMSG_COMPAT))
2644 		return -EINVAL;
2645 
2646 	CLASS(fd, f)(fd);
2647 
2648 	if (fd_empty(f))
2649 		return -EBADF;
2650 	sock = sock_from_file(fd_file(f));
2651 	if (unlikely(!sock))
2652 		return -ENOTSOCK;
2653 
2654 	return ___sys_sendmsg(sock, msg, &msg_sys, flags, NULL, 0);
2655 }
2656 
2657 SYSCALL_DEFINE3(sendmsg, int, fd, struct user_msghdr __user *, msg, unsigned int, flags)
2658 {
2659 	return __sys_sendmsg(fd, msg, flags, true);
2660 }
2661 
2662 /*
2663  *	Linux sendmmsg interface
2664  */
2665 
2666 int __sys_sendmmsg(int fd, struct mmsghdr __user *mmsg, unsigned int vlen,
2667 		   unsigned int flags, bool forbid_cmsg_compat)
2668 {
2669 	int err, datagrams;
2670 	struct socket *sock;
2671 	struct mmsghdr __user *entry;
2672 	struct compat_mmsghdr __user *compat_entry;
2673 	struct msghdr msg_sys;
2674 	struct used_address used_address;
2675 	unsigned int oflags = flags;
2676 
2677 	if (forbid_cmsg_compat && (flags & MSG_CMSG_COMPAT))
2678 		return -EINVAL;
2679 
2680 	if (vlen > UIO_MAXIOV)
2681 		vlen = UIO_MAXIOV;
2682 
2683 	datagrams = 0;
2684 
2685 	CLASS(fd, f)(fd);
2686 
2687 	if (fd_empty(f))
2688 		return -EBADF;
2689 	sock = sock_from_file(fd_file(f));
2690 	if (unlikely(!sock))
2691 		return -ENOTSOCK;
2692 
2693 	used_address.name_len = UINT_MAX;
2694 	entry = mmsg;
2695 	compat_entry = (struct compat_mmsghdr __user *)mmsg;
2696 	err = 0;
2697 	flags |= MSG_BATCH;
2698 
2699 	while (datagrams < vlen) {
2700 		if (datagrams == vlen - 1)
2701 			flags = oflags;
2702 
2703 		if (MSG_CMSG_COMPAT & flags) {
2704 			err = ___sys_sendmsg(sock, (struct user_msghdr __user *)compat_entry,
2705 					     &msg_sys, flags, &used_address, MSG_EOR);
2706 			if (err < 0)
2707 				break;
2708 			err = __put_user(err, &compat_entry->msg_len);
2709 			++compat_entry;
2710 		} else {
2711 			err = ___sys_sendmsg(sock,
2712 					     (struct user_msghdr __user *)entry,
2713 					     &msg_sys, flags, &used_address, MSG_EOR);
2714 			if (err < 0)
2715 				break;
2716 			err = put_user(err, &entry->msg_len);
2717 			++entry;
2718 		}
2719 
2720 		if (err)
2721 			break;
2722 		++datagrams;
2723 		if (msg_data_left(&msg_sys))
2724 			break;
2725 		cond_resched();
2726 	}
2727 
2728 	/* We only return an error if no datagrams were able to be sent */
2729 	if (datagrams != 0)
2730 		return datagrams;
2731 
2732 	return err;
2733 }
2734 
2735 SYSCALL_DEFINE4(sendmmsg, int, fd, struct mmsghdr __user *, mmsg,
2736 		unsigned int, vlen, unsigned int, flags)
2737 {
2738 	return __sys_sendmmsg(fd, mmsg, vlen, flags, true);
2739 }
2740 
2741 static int recvmsg_copy_msghdr(struct msghdr *msg,
2742 			       struct user_msghdr __user *umsg, unsigned flags,
2743 			       struct sockaddr __user **uaddr,
2744 			       struct iovec **iov)
2745 {
2746 	ssize_t err;
2747 
2748 	if (MSG_CMSG_COMPAT & flags) {
2749 		struct compat_msghdr __user *msg_compat;
2750 
2751 		msg_compat = (struct compat_msghdr __user *) umsg;
2752 		err = get_compat_msghdr(msg, msg_compat, uaddr, iov);
2753 	} else {
2754 		err = copy_msghdr_from_user(msg, umsg, uaddr, iov);
2755 	}
2756 	if (err < 0)
2757 		return err;
2758 
2759 	return 0;
2760 }
2761 
2762 static int ____sys_recvmsg(struct socket *sock, struct msghdr *msg_sys,
2763 			   struct user_msghdr __user *msg,
2764 			   struct sockaddr __user *uaddr,
2765 			   unsigned int flags, int nosec)
2766 {
2767 	struct compat_msghdr __user *msg_compat =
2768 					(struct compat_msghdr __user *) msg;
2769 	int __user *uaddr_len = COMPAT_NAMELEN(msg);
2770 	struct sockaddr_storage addr;
2771 	unsigned long cmsg_ptr;
2772 	int len;
2773 	ssize_t err;
2774 
2775 	msg_sys->msg_name = &addr;
2776 	cmsg_ptr = (unsigned long)msg_sys->msg_control;
2777 	msg_sys->msg_flags = flags & (MSG_CMSG_CLOEXEC|MSG_CMSG_COMPAT);
2778 
2779 	/* We assume all kernel code knows the size of sockaddr_storage */
2780 	msg_sys->msg_namelen = 0;
2781 
2782 	if (sock->file->f_flags & O_NONBLOCK)
2783 		flags |= MSG_DONTWAIT;
2784 
2785 	if (unlikely(nosec))
2786 		err = sock_recvmsg_nosec(sock, msg_sys, flags);
2787 	else
2788 		err = sock_recvmsg(sock, msg_sys, flags);
2789 
2790 	if (err < 0)
2791 		goto out;
2792 	len = err;
2793 
2794 	if (uaddr != NULL) {
2795 		err = move_addr_to_user(&addr,
2796 					msg_sys->msg_namelen, uaddr,
2797 					uaddr_len);
2798 		if (err < 0)
2799 			goto out;
2800 	}
2801 	err = __put_user((msg_sys->msg_flags & ~MSG_CMSG_COMPAT),
2802 			 COMPAT_FLAGS(msg));
2803 	if (err)
2804 		goto out;
2805 	if (MSG_CMSG_COMPAT & flags)
2806 		err = __put_user((unsigned long)msg_sys->msg_control - cmsg_ptr,
2807 				 &msg_compat->msg_controllen);
2808 	else
2809 		err = __put_user((unsigned long)msg_sys->msg_control - cmsg_ptr,
2810 				 &msg->msg_controllen);
2811 	if (err)
2812 		goto out;
2813 	err = len;
2814 out:
2815 	return err;
2816 }
2817 
2818 static int ___sys_recvmsg(struct socket *sock, struct user_msghdr __user *msg,
2819 			 struct msghdr *msg_sys, unsigned int flags, int nosec)
2820 {
2821 	struct iovec iovstack[UIO_FASTIOV], *iov = iovstack;
2822 	/* user mode address pointers */
2823 	struct sockaddr __user *uaddr;
2824 	ssize_t err;
2825 
2826 	err = recvmsg_copy_msghdr(msg_sys, msg, flags, &uaddr, &iov);
2827 	if (err < 0)
2828 		return err;
2829 
2830 	err = ____sys_recvmsg(sock, msg_sys, msg, uaddr, flags, nosec);
2831 	kfree(iov);
2832 	return err;
2833 }
2834 
2835 /*
2836  *	BSD recvmsg interface
2837  */
2838 
2839 long __sys_recvmsg_sock(struct socket *sock, struct msghdr *msg,
2840 			struct user_msghdr __user *umsg,
2841 			struct sockaddr __user *uaddr, unsigned int flags)
2842 {
2843 	return ____sys_recvmsg(sock, msg, umsg, uaddr, flags, 0);
2844 }
2845 
2846 long __sys_recvmsg(int fd, struct user_msghdr __user *msg, unsigned int flags,
2847 		   bool forbid_cmsg_compat)
2848 {
2849 	struct msghdr msg_sys;
2850 	struct socket *sock;
2851 
2852 	if (forbid_cmsg_compat && (flags & MSG_CMSG_COMPAT))
2853 		return -EINVAL;
2854 
2855 	CLASS(fd, f)(fd);
2856 
2857 	if (fd_empty(f))
2858 		return -EBADF;
2859 	sock = sock_from_file(fd_file(f));
2860 	if (unlikely(!sock))
2861 		return -ENOTSOCK;
2862 
2863 	return ___sys_recvmsg(sock, msg, &msg_sys, flags, 0);
2864 }
2865 
2866 SYSCALL_DEFINE3(recvmsg, int, fd, struct user_msghdr __user *, msg,
2867 		unsigned int, flags)
2868 {
2869 	return __sys_recvmsg(fd, msg, flags, true);
2870 }
2871 
2872 /*
2873  *     Linux recvmmsg interface
2874  */
2875 
2876 static int do_recvmmsg(int fd, struct mmsghdr __user *mmsg,
2877 			  unsigned int vlen, unsigned int flags,
2878 			  struct timespec64 *timeout)
2879 {
2880 	int err = 0, datagrams;
2881 	struct socket *sock;
2882 	struct mmsghdr __user *entry;
2883 	struct compat_mmsghdr __user *compat_entry;
2884 	struct msghdr msg_sys;
2885 	struct timespec64 end_time;
2886 	struct timespec64 timeout64;
2887 
2888 	if (timeout &&
2889 	    poll_select_set_timeout(&end_time, timeout->tv_sec,
2890 				    timeout->tv_nsec))
2891 		return -EINVAL;
2892 
2893 	datagrams = 0;
2894 
2895 	CLASS(fd, f)(fd);
2896 
2897 	if (fd_empty(f))
2898 		return -EBADF;
2899 	sock = sock_from_file(fd_file(f));
2900 	if (unlikely(!sock))
2901 		return -ENOTSOCK;
2902 
2903 	if (likely(!(flags & MSG_ERRQUEUE))) {
2904 		err = sock_error(sock->sk);
2905 		if (err)
2906 			return err;
2907 	}
2908 
2909 	entry = mmsg;
2910 	compat_entry = (struct compat_mmsghdr __user *)mmsg;
2911 
2912 	while (datagrams < vlen) {
2913 		/*
2914 		 * No need to ask LSM for more than the first datagram.
2915 		 */
2916 		if (MSG_CMSG_COMPAT & flags) {
2917 			err = ___sys_recvmsg(sock, (struct user_msghdr __user *)compat_entry,
2918 					     &msg_sys, flags & ~MSG_WAITFORONE,
2919 					     datagrams);
2920 			if (err < 0)
2921 				break;
2922 			err = __put_user(err, &compat_entry->msg_len);
2923 			++compat_entry;
2924 		} else {
2925 			err = ___sys_recvmsg(sock,
2926 					     (struct user_msghdr __user *)entry,
2927 					     &msg_sys, flags & ~MSG_WAITFORONE,
2928 					     datagrams);
2929 			if (err < 0)
2930 				break;
2931 			err = put_user(err, &entry->msg_len);
2932 			++entry;
2933 		}
2934 
2935 		if (err)
2936 			break;
2937 		++datagrams;
2938 
2939 		/* MSG_WAITFORONE turns on MSG_DONTWAIT after one packet */
2940 		if (flags & MSG_WAITFORONE)
2941 			flags |= MSG_DONTWAIT;
2942 
2943 		if (timeout) {
2944 			ktime_get_ts64(&timeout64);
2945 			*timeout = timespec64_sub(end_time, timeout64);
2946 			if (timeout->tv_sec < 0) {
2947 				timeout->tv_sec = timeout->tv_nsec = 0;
2948 				break;
2949 			}
2950 
2951 			/* Timeout, return less than vlen datagrams */
2952 			if (timeout->tv_nsec == 0 && timeout->tv_sec == 0)
2953 				break;
2954 		}
2955 
2956 		/* Out of band data, return right away */
2957 		if (msg_sys.msg_flags & MSG_OOB)
2958 			break;
2959 		cond_resched();
2960 	}
2961 
2962 	if (err == 0)
2963 		return datagrams;
2964 
2965 	if (datagrams == 0)
2966 		return err;
2967 
2968 	/*
2969 	 * We may return less entries than requested (vlen) if the
2970 	 * sock is non block and there aren't enough datagrams...
2971 	 */
2972 	if (err != -EAGAIN) {
2973 		/*
2974 		 * ... or  if recvmsg returns an error after we
2975 		 * received some datagrams, where we record the
2976 		 * error to return on the next call or if the
2977 		 * app asks about it using getsockopt(SO_ERROR).
2978 		 */
2979 		WRITE_ONCE(sock->sk->sk_err, -err);
2980 	}
2981 	return datagrams;
2982 }
2983 
2984 int __sys_recvmmsg(int fd, struct mmsghdr __user *mmsg,
2985 		   unsigned int vlen, unsigned int flags,
2986 		   struct __kernel_timespec __user *timeout,
2987 		   struct old_timespec32 __user *timeout32)
2988 {
2989 	int datagrams;
2990 	struct timespec64 timeout_sys;
2991 
2992 	if (timeout && get_timespec64(&timeout_sys, timeout))
2993 		return -EFAULT;
2994 
2995 	if (timeout32 && get_old_timespec32(&timeout_sys, timeout32))
2996 		return -EFAULT;
2997 
2998 	if (!timeout && !timeout32)
2999 		return do_recvmmsg(fd, mmsg, vlen, flags, NULL);
3000 
3001 	datagrams = do_recvmmsg(fd, mmsg, vlen, flags, &timeout_sys);
3002 
3003 	if (datagrams <= 0)
3004 		return datagrams;
3005 
3006 	if (timeout && put_timespec64(&timeout_sys, timeout))
3007 		datagrams = -EFAULT;
3008 
3009 	if (timeout32 && put_old_timespec32(&timeout_sys, timeout32))
3010 		datagrams = -EFAULT;
3011 
3012 	return datagrams;
3013 }
3014 
3015 SYSCALL_DEFINE5(recvmmsg, int, fd, struct mmsghdr __user *, mmsg,
3016 		unsigned int, vlen, unsigned int, flags,
3017 		struct __kernel_timespec __user *, timeout)
3018 {
3019 	if (flags & MSG_CMSG_COMPAT)
3020 		return -EINVAL;
3021 
3022 	return __sys_recvmmsg(fd, mmsg, vlen, flags, timeout, NULL);
3023 }
3024 
3025 #ifdef CONFIG_COMPAT_32BIT_TIME
3026 SYSCALL_DEFINE5(recvmmsg_time32, int, fd, struct mmsghdr __user *, mmsg,
3027 		unsigned int, vlen, unsigned int, flags,
3028 		struct old_timespec32 __user *, timeout)
3029 {
3030 	if (flags & MSG_CMSG_COMPAT)
3031 		return -EINVAL;
3032 
3033 	return __sys_recvmmsg(fd, mmsg, vlen, flags, NULL, timeout);
3034 }
3035 #endif
3036 
3037 #ifdef __ARCH_WANT_SYS_SOCKETCALL
3038 /* Argument list sizes for sys_socketcall */
3039 #define AL(x) ((x) * sizeof(unsigned long))
3040 static const unsigned char nargs[21] = {
3041 	AL(0), AL(3), AL(3), AL(3), AL(2), AL(3),
3042 	AL(3), AL(3), AL(4), AL(4), AL(4), AL(6),
3043 	AL(6), AL(2), AL(5), AL(5), AL(3), AL(3),
3044 	AL(4), AL(5), AL(4)
3045 };
3046 
3047 #undef AL
3048 
3049 /*
3050  *	System call vectors.
3051  *
3052  *	Argument checking cleaned up. Saved 20% in size.
3053  *  This function doesn't need to set the kernel lock because
3054  *  it is set by the callees.
3055  */
3056 
3057 SYSCALL_DEFINE2(socketcall, int, call, unsigned long __user *, args)
3058 {
3059 	unsigned long a[AUDITSC_ARGS];
3060 	unsigned long a0, a1;
3061 	int err;
3062 	unsigned int len;
3063 
3064 	if (call < 1 || call > SYS_SENDMMSG)
3065 		return -EINVAL;
3066 	call = array_index_nospec(call, SYS_SENDMMSG + 1);
3067 
3068 	len = nargs[call];
3069 	if (len > sizeof(a))
3070 		return -EINVAL;
3071 
3072 	/* copy_from_user should be SMP safe. */
3073 	if (copy_from_user(a, args, len))
3074 		return -EFAULT;
3075 
3076 	err = audit_socketcall(nargs[call] / sizeof(unsigned long), a);
3077 	if (err)
3078 		return err;
3079 
3080 	a0 = a[0];
3081 	a1 = a[1];
3082 
3083 	switch (call) {
3084 	case SYS_SOCKET:
3085 		err = __sys_socket(a0, a1, a[2]);
3086 		break;
3087 	case SYS_BIND:
3088 		err = __sys_bind(a0, (struct sockaddr __user *)a1, a[2]);
3089 		break;
3090 	case SYS_CONNECT:
3091 		err = __sys_connect(a0, (struct sockaddr __user *)a1, a[2]);
3092 		break;
3093 	case SYS_LISTEN:
3094 		err = __sys_listen(a0, a1);
3095 		break;
3096 	case SYS_ACCEPT:
3097 		err = __sys_accept4(a0, (struct sockaddr __user *)a1,
3098 				    (int __user *)a[2], 0);
3099 		break;
3100 	case SYS_GETSOCKNAME:
3101 		err =
3102 		    __sys_getsockname(a0, (struct sockaddr __user *)a1,
3103 				      (int __user *)a[2]);
3104 		break;
3105 	case SYS_GETPEERNAME:
3106 		err =
3107 		    __sys_getpeername(a0, (struct sockaddr __user *)a1,
3108 				      (int __user *)a[2]);
3109 		break;
3110 	case SYS_SOCKETPAIR:
3111 		err = __sys_socketpair(a0, a1, a[2], (int __user *)a[3]);
3112 		break;
3113 	case SYS_SEND:
3114 		err = __sys_sendto(a0, (void __user *)a1, a[2], a[3],
3115 				   NULL, 0);
3116 		break;
3117 	case SYS_SENDTO:
3118 		err = __sys_sendto(a0, (void __user *)a1, a[2], a[3],
3119 				   (struct sockaddr __user *)a[4], a[5]);
3120 		break;
3121 	case SYS_RECV:
3122 		err = __sys_recvfrom(a0, (void __user *)a1, a[2], a[3],
3123 				     NULL, NULL);
3124 		break;
3125 	case SYS_RECVFROM:
3126 		err = __sys_recvfrom(a0, (void __user *)a1, a[2], a[3],
3127 				     (struct sockaddr __user *)a[4],
3128 				     (int __user *)a[5]);
3129 		break;
3130 	case SYS_SHUTDOWN:
3131 		err = __sys_shutdown(a0, a1);
3132 		break;
3133 	case SYS_SETSOCKOPT:
3134 		err = __sys_setsockopt(a0, a1, a[2], (char __user *)a[3],
3135 				       a[4]);
3136 		break;
3137 	case SYS_GETSOCKOPT:
3138 		err =
3139 		    __sys_getsockopt(a0, a1, a[2], (char __user *)a[3],
3140 				     (int __user *)a[4]);
3141 		break;
3142 	case SYS_SENDMSG:
3143 		err = __sys_sendmsg(a0, (struct user_msghdr __user *)a1,
3144 				    a[2], true);
3145 		break;
3146 	case SYS_SENDMMSG:
3147 		err = __sys_sendmmsg(a0, (struct mmsghdr __user *)a1, a[2],
3148 				     a[3], true);
3149 		break;
3150 	case SYS_RECVMSG:
3151 		err = __sys_recvmsg(a0, (struct user_msghdr __user *)a1,
3152 				    a[2], true);
3153 		break;
3154 	case SYS_RECVMMSG:
3155 		if (IS_ENABLED(CONFIG_64BIT))
3156 			err = __sys_recvmmsg(a0, (struct mmsghdr __user *)a1,
3157 					     a[2], a[3],
3158 					     (struct __kernel_timespec __user *)a[4],
3159 					     NULL);
3160 		else
3161 			err = __sys_recvmmsg(a0, (struct mmsghdr __user *)a1,
3162 					     a[2], a[3], NULL,
3163 					     (struct old_timespec32 __user *)a[4]);
3164 		break;
3165 	case SYS_ACCEPT4:
3166 		err = __sys_accept4(a0, (struct sockaddr __user *)a1,
3167 				    (int __user *)a[2], a[3]);
3168 		break;
3169 	default:
3170 		err = -EINVAL;
3171 		break;
3172 	}
3173 	return err;
3174 }
3175 
3176 #endif				/* __ARCH_WANT_SYS_SOCKETCALL */
3177 
3178 /**
3179  *	sock_register - add a socket protocol handler
3180  *	@ops: description of protocol
3181  *
3182  *	This function is called by a protocol handler that wants to
3183  *	advertise its address family, and have it linked into the
3184  *	socket interface. The value ops->family corresponds to the
3185  *	socket system call protocol family.
3186  */
3187 int sock_register(const struct net_proto_family *ops)
3188 {
3189 	int err;
3190 
3191 	if (ops->family >= NPROTO) {
3192 		pr_crit("protocol %d >= NPROTO(%d)\n", ops->family, NPROTO);
3193 		return -ENOBUFS;
3194 	}
3195 
3196 	spin_lock(&net_family_lock);
3197 	if (rcu_dereference_protected(net_families[ops->family],
3198 				      lockdep_is_held(&net_family_lock)))
3199 		err = -EEXIST;
3200 	else {
3201 		rcu_assign_pointer(net_families[ops->family], ops);
3202 		err = 0;
3203 	}
3204 	spin_unlock(&net_family_lock);
3205 
3206 	pr_info("NET: Registered %s protocol family\n", pf_family_names[ops->family]);
3207 	return err;
3208 }
3209 EXPORT_SYMBOL(sock_register);
3210 
3211 /**
3212  *	sock_unregister - remove a protocol handler
3213  *	@family: protocol family to remove
3214  *
3215  *	This function is called by a protocol handler that wants to
3216  *	remove its address family, and have it unlinked from the
3217  *	new socket creation.
3218  *
3219  *	If protocol handler is a module, then it can use module reference
3220  *	counts to protect against new references. If protocol handler is not
3221  *	a module then it needs to provide its own protection in
3222  *	the ops->create routine.
3223  */
3224 void sock_unregister(int family)
3225 {
3226 	BUG_ON(family < 0 || family >= NPROTO);
3227 
3228 	spin_lock(&net_family_lock);
3229 	RCU_INIT_POINTER(net_families[family], NULL);
3230 	spin_unlock(&net_family_lock);
3231 
3232 	synchronize_rcu();
3233 
3234 	pr_info("NET: Unregistered %s protocol family\n", pf_family_names[family]);
3235 }
3236 EXPORT_SYMBOL(sock_unregister);
3237 
3238 bool sock_is_registered(int family)
3239 {
3240 	return family < NPROTO && rcu_access_pointer(net_families[family]);
3241 }
3242 
3243 static int __init sock_init(void)
3244 {
3245 	int err;
3246 	/*
3247 	 *      Initialize the network sysctl infrastructure.
3248 	 */
3249 	err = net_sysctl_init();
3250 	if (err)
3251 		goto out;
3252 
3253 	/*
3254 	 *      Initialize skbuff SLAB cache
3255 	 */
3256 	skb_init();
3257 
3258 	/*
3259 	 *      Initialize the protocols module.
3260 	 */
3261 
3262 	init_inodecache();
3263 
3264 	err = register_filesystem(&sock_fs_type);
3265 	if (err)
3266 		goto out;
3267 	sock_mnt = kern_mount(&sock_fs_type);
3268 	if (IS_ERR(sock_mnt)) {
3269 		err = PTR_ERR(sock_mnt);
3270 		goto out_mount;
3271 	}
3272 
3273 	/* The real protocol initialization is performed in later initcalls.
3274 	 */
3275 
3276 #ifdef CONFIG_NETFILTER
3277 	err = netfilter_init();
3278 	if (err)
3279 		goto out;
3280 #endif
3281 
3282 	ptp_classifier_init();
3283 
3284 out:
3285 	return err;
3286 
3287 out_mount:
3288 	unregister_filesystem(&sock_fs_type);
3289 	goto out;
3290 }
3291 
3292 core_initcall(sock_init);	/* early initcall */
3293 
3294 #ifdef CONFIG_PROC_FS
3295 void socket_seq_show(struct seq_file *seq)
3296 {
3297 	seq_printf(seq, "sockets: used %d\n",
3298 		   sock_inuse_get(seq->private));
3299 }
3300 #endif				/* CONFIG_PROC_FS */
3301 
3302 /* Handle the fact that while struct ifreq has the same *layout* on
3303  * 32/64 for everything but ifreq::ifru_ifmap and ifreq::ifru_data,
3304  * which are handled elsewhere, it still has different *size* due to
3305  * ifreq::ifru_ifmap (which is 16 bytes on 32 bit, 24 bytes on 64-bit,
3306  * resulting in struct ifreq being 32 and 40 bytes respectively).
3307  * As a result, if the struct happens to be at the end of a page and
3308  * the next page isn't readable/writable, we get a fault. To prevent
3309  * that, copy back and forth to the full size.
3310  */
3311 int get_user_ifreq(struct ifreq *ifr, void __user **ifrdata, void __user *arg)
3312 {
3313 	if (in_compat_syscall()) {
3314 		struct compat_ifreq *ifr32 = (struct compat_ifreq *)ifr;
3315 
3316 		memset(ifr, 0, sizeof(*ifr));
3317 		if (copy_from_user(ifr32, arg, sizeof(*ifr32)))
3318 			return -EFAULT;
3319 
3320 		if (ifrdata)
3321 			*ifrdata = compat_ptr(ifr32->ifr_data);
3322 
3323 		return 0;
3324 	}
3325 
3326 	if (copy_from_user(ifr, arg, sizeof(*ifr)))
3327 		return -EFAULT;
3328 
3329 	if (ifrdata)
3330 		*ifrdata = ifr->ifr_data;
3331 
3332 	return 0;
3333 }
3334 EXPORT_SYMBOL(get_user_ifreq);
3335 
3336 int put_user_ifreq(struct ifreq *ifr, void __user *arg)
3337 {
3338 	size_t size = sizeof(*ifr);
3339 
3340 	if (in_compat_syscall())
3341 		size = sizeof(struct compat_ifreq);
3342 
3343 	if (copy_to_user(arg, ifr, size))
3344 		return -EFAULT;
3345 
3346 	return 0;
3347 }
3348 EXPORT_SYMBOL(put_user_ifreq);
3349 
3350 #ifdef CONFIG_COMPAT
3351 static int compat_siocwandev(struct net *net, struct compat_ifreq __user *uifr32)
3352 {
3353 	compat_uptr_t uptr32;
3354 	struct ifreq ifr;
3355 	void __user *saved;
3356 	int err;
3357 
3358 	if (get_user_ifreq(&ifr, NULL, uifr32))
3359 		return -EFAULT;
3360 
3361 	if (get_user(uptr32, &uifr32->ifr_settings.ifs_ifsu))
3362 		return -EFAULT;
3363 
3364 	saved = ifr.ifr_settings.ifs_ifsu.raw_hdlc;
3365 	ifr.ifr_settings.ifs_ifsu.raw_hdlc = compat_ptr(uptr32);
3366 
3367 	err = dev_ioctl(net, SIOCWANDEV, &ifr, NULL, NULL);
3368 	if (!err) {
3369 		ifr.ifr_settings.ifs_ifsu.raw_hdlc = saved;
3370 		if (put_user_ifreq(&ifr, uifr32))
3371 			err = -EFAULT;
3372 	}
3373 	return err;
3374 }
3375 
3376 /* Handle ioctls that use ifreq::ifr_data and just need struct ifreq converted */
3377 static int compat_ifr_data_ioctl(struct net *net, unsigned int cmd,
3378 				 struct compat_ifreq __user *u_ifreq32)
3379 {
3380 	struct ifreq ifreq;
3381 	void __user *data;
3382 
3383 	if (!is_socket_ioctl_cmd(cmd))
3384 		return -ENOTTY;
3385 	if (get_user_ifreq(&ifreq, &data, u_ifreq32))
3386 		return -EFAULT;
3387 	ifreq.ifr_data = data;
3388 
3389 	return dev_ioctl(net, cmd, &ifreq, data, NULL);
3390 }
3391 
3392 static int compat_sock_ioctl_trans(struct file *file, struct socket *sock,
3393 			 unsigned int cmd, unsigned long arg)
3394 {
3395 	void __user *argp = compat_ptr(arg);
3396 	struct sock *sk = sock->sk;
3397 	struct net *net = sock_net(sk);
3398 	const struct proto_ops *ops;
3399 
3400 	if (cmd >= SIOCDEVPRIVATE && cmd <= (SIOCDEVPRIVATE + 15))
3401 		return sock_ioctl(file, cmd, (unsigned long)argp);
3402 
3403 	switch (cmd) {
3404 	case SIOCWANDEV:
3405 		return compat_siocwandev(net, argp);
3406 	case SIOCGSTAMP_OLD:
3407 	case SIOCGSTAMPNS_OLD:
3408 		ops = READ_ONCE(sock->ops);
3409 		if (!ops->gettstamp)
3410 			return -ENOIOCTLCMD;
3411 		return ops->gettstamp(sock, argp, cmd == SIOCGSTAMP_OLD,
3412 				      !COMPAT_USE_64BIT_TIME);
3413 
3414 	case SIOCETHTOOL:
3415 	case SIOCBONDSLAVEINFOQUERY:
3416 	case SIOCBONDINFOQUERY:
3417 	case SIOCSHWTSTAMP:
3418 	case SIOCGHWTSTAMP:
3419 		return compat_ifr_data_ioctl(net, cmd, argp);
3420 
3421 	case FIOSETOWN:
3422 	case SIOCSPGRP:
3423 	case FIOGETOWN:
3424 	case SIOCGPGRP:
3425 	case SIOCBRADDBR:
3426 	case SIOCBRDELBR:
3427 	case SIOCGIFVLAN:
3428 	case SIOCSIFVLAN:
3429 	case SIOCGSKNS:
3430 	case SIOCGSTAMP_NEW:
3431 	case SIOCGSTAMPNS_NEW:
3432 	case SIOCGIFCONF:
3433 	case SIOCSIFBR:
3434 	case SIOCGIFBR:
3435 		return sock_ioctl(file, cmd, arg);
3436 
3437 	case SIOCGIFFLAGS:
3438 	case SIOCSIFFLAGS:
3439 	case SIOCGIFMAP:
3440 	case SIOCSIFMAP:
3441 	case SIOCGIFMETRIC:
3442 	case SIOCSIFMETRIC:
3443 	case SIOCGIFMTU:
3444 	case SIOCSIFMTU:
3445 	case SIOCGIFMEM:
3446 	case SIOCSIFMEM:
3447 	case SIOCGIFHWADDR:
3448 	case SIOCSIFHWADDR:
3449 	case SIOCADDMULTI:
3450 	case SIOCDELMULTI:
3451 	case SIOCGIFINDEX:
3452 	case SIOCGIFADDR:
3453 	case SIOCSIFADDR:
3454 	case SIOCSIFHWBROADCAST:
3455 	case SIOCDIFADDR:
3456 	case SIOCGIFBRDADDR:
3457 	case SIOCSIFBRDADDR:
3458 	case SIOCGIFDSTADDR:
3459 	case SIOCSIFDSTADDR:
3460 	case SIOCGIFNETMASK:
3461 	case SIOCSIFNETMASK:
3462 	case SIOCSIFPFLAGS:
3463 	case SIOCGIFPFLAGS:
3464 	case SIOCGIFTXQLEN:
3465 	case SIOCSIFTXQLEN:
3466 	case SIOCBRADDIF:
3467 	case SIOCBRDELIF:
3468 	case SIOCGIFNAME:
3469 	case SIOCSIFNAME:
3470 	case SIOCGMIIPHY:
3471 	case SIOCGMIIREG:
3472 	case SIOCSMIIREG:
3473 	case SIOCBONDENSLAVE:
3474 	case SIOCBONDRELEASE:
3475 	case SIOCBONDSETHWADDR:
3476 	case SIOCBONDCHANGEACTIVE:
3477 	case SIOCSARP:
3478 	case SIOCGARP:
3479 	case SIOCDARP:
3480 	case SIOCOUTQ:
3481 	case SIOCOUTQNSD:
3482 	case SIOCATMARK:
3483 		return sock_do_ioctl(net, sock, cmd, arg);
3484 	}
3485 
3486 	return -ENOIOCTLCMD;
3487 }
3488 
3489 static long compat_sock_ioctl(struct file *file, unsigned int cmd,
3490 			      unsigned long arg)
3491 {
3492 	struct socket *sock = file->private_data;
3493 	const struct proto_ops *ops = READ_ONCE(sock->ops);
3494 	int ret = -ENOIOCTLCMD;
3495 	struct sock *sk;
3496 	struct net *net;
3497 
3498 	sk = sock->sk;
3499 	net = sock_net(sk);
3500 
3501 	if (ops->compat_ioctl)
3502 		ret = ops->compat_ioctl(sock, cmd, arg);
3503 
3504 	if (ret == -ENOIOCTLCMD &&
3505 	    (cmd >= SIOCIWFIRST && cmd <= SIOCIWLAST))
3506 		ret = compat_wext_handle_ioctl(net, cmd, arg);
3507 
3508 	if (ret == -ENOIOCTLCMD)
3509 		ret = compat_sock_ioctl_trans(file, sock, cmd, arg);
3510 
3511 	return ret;
3512 }
3513 #endif
3514 
3515 /**
3516  *	kernel_bind - bind an address to a socket (kernel space)
3517  *	@sock: socket
3518  *	@addr: address
3519  *	@addrlen: length of address
3520  *
3521  *	Returns 0 or an error.
3522  */
3523 
3524 int kernel_bind(struct socket *sock, struct sockaddr *addr, int addrlen)
3525 {
3526 	struct sockaddr_storage address;
3527 
3528 	memcpy(&address, addr, addrlen);
3529 
3530 	return READ_ONCE(sock->ops)->bind(sock, (struct sockaddr *)&address,
3531 					  addrlen);
3532 }
3533 EXPORT_SYMBOL(kernel_bind);
3534 
3535 /**
3536  *	kernel_listen - move socket to listening state (kernel space)
3537  *	@sock: socket
3538  *	@backlog: pending connections queue size
3539  *
3540  *	Returns 0 or an error.
3541  */
3542 
3543 int kernel_listen(struct socket *sock, int backlog)
3544 {
3545 	return READ_ONCE(sock->ops)->listen(sock, backlog);
3546 }
3547 EXPORT_SYMBOL(kernel_listen);
3548 
3549 /**
3550  *	kernel_accept - accept a connection (kernel space)
3551  *	@sock: listening socket
3552  *	@newsock: new connected socket
3553  *	@flags: flags
3554  *
3555  *	@flags must be SOCK_CLOEXEC, SOCK_NONBLOCK or 0.
3556  *	If it fails, @newsock is guaranteed to be %NULL.
3557  *	Returns 0 or an error.
3558  */
3559 
3560 int kernel_accept(struct socket *sock, struct socket **newsock, int flags)
3561 {
3562 	struct sock *sk = sock->sk;
3563 	const struct proto_ops *ops = READ_ONCE(sock->ops);
3564 	struct proto_accept_arg arg = {
3565 		.flags = flags,
3566 		.kern = true,
3567 	};
3568 	int err;
3569 
3570 	err = sock_create_lite(sk->sk_family, sk->sk_type, sk->sk_protocol,
3571 			       newsock);
3572 	if (err < 0)
3573 		goto done;
3574 
3575 	err = ops->accept(sock, *newsock, &arg);
3576 	if (err < 0) {
3577 		sock_release(*newsock);
3578 		*newsock = NULL;
3579 		goto done;
3580 	}
3581 
3582 	(*newsock)->ops = ops;
3583 	__module_get(ops->owner);
3584 
3585 done:
3586 	return err;
3587 }
3588 EXPORT_SYMBOL(kernel_accept);
3589 
3590 /**
3591  *	kernel_connect - connect a socket (kernel space)
3592  *	@sock: socket
3593  *	@addr: address
3594  *	@addrlen: address length
3595  *	@flags: flags (O_NONBLOCK, ...)
3596  *
3597  *	For datagram sockets, @addr is the address to which datagrams are sent
3598  *	by default, and the only address from which datagrams are received.
3599  *	For stream sockets, attempts to connect to @addr.
3600  *	Returns 0 or an error code.
3601  */
3602 
3603 int kernel_connect(struct socket *sock, struct sockaddr *addr, int addrlen,
3604 		   int flags)
3605 {
3606 	struct sockaddr_storage address;
3607 
3608 	memcpy(&address, addr, addrlen);
3609 
3610 	return READ_ONCE(sock->ops)->connect(sock, (struct sockaddr *)&address,
3611 					     addrlen, flags);
3612 }
3613 EXPORT_SYMBOL(kernel_connect);
3614 
3615 /**
3616  *	kernel_getsockname - get the address which the socket is bound (kernel space)
3617  *	@sock: socket
3618  *	@addr: address holder
3619  *
3620  * 	Fills the @addr pointer with the address which the socket is bound.
3621  *	Returns the length of the address in bytes or an error code.
3622  */
3623 
3624 int kernel_getsockname(struct socket *sock, struct sockaddr *addr)
3625 {
3626 	return READ_ONCE(sock->ops)->getname(sock, addr, 0);
3627 }
3628 EXPORT_SYMBOL(kernel_getsockname);
3629 
3630 /**
3631  *	kernel_getpeername - get the address which the socket is connected (kernel space)
3632  *	@sock: socket
3633  *	@addr: address holder
3634  *
3635  * 	Fills the @addr pointer with the address which the socket is connected.
3636  *	Returns the length of the address in bytes or an error code.
3637  */
3638 
3639 int kernel_getpeername(struct socket *sock, struct sockaddr *addr)
3640 {
3641 	return READ_ONCE(sock->ops)->getname(sock, addr, 1);
3642 }
3643 EXPORT_SYMBOL(kernel_getpeername);
3644 
3645 /**
3646  *	kernel_sock_shutdown - shut down part of a full-duplex connection (kernel space)
3647  *	@sock: socket
3648  *	@how: connection part
3649  *
3650  *	Returns 0 or an error.
3651  */
3652 
3653 int kernel_sock_shutdown(struct socket *sock, enum sock_shutdown_cmd how)
3654 {
3655 	return READ_ONCE(sock->ops)->shutdown(sock, how);
3656 }
3657 EXPORT_SYMBOL(kernel_sock_shutdown);
3658 
3659 /**
3660  *	kernel_sock_ip_overhead - returns the IP overhead imposed by a socket
3661  *	@sk: socket
3662  *
3663  *	This routine returns the IP overhead imposed by a socket i.e.
3664  *	the length of the underlying IP header, depending on whether
3665  *	this is an IPv4 or IPv6 socket and the length from IP options turned
3666  *	on at the socket. Assumes that the caller has a lock on the socket.
3667  */
3668 
3669 u32 kernel_sock_ip_overhead(struct sock *sk)
3670 {
3671 	struct inet_sock *inet;
3672 	struct ip_options_rcu *opt;
3673 	u32 overhead = 0;
3674 #if IS_ENABLED(CONFIG_IPV6)
3675 	struct ipv6_pinfo *np;
3676 	struct ipv6_txoptions *optv6 = NULL;
3677 #endif /* IS_ENABLED(CONFIG_IPV6) */
3678 
3679 	if (!sk)
3680 		return overhead;
3681 
3682 	switch (sk->sk_family) {
3683 	case AF_INET:
3684 		inet = inet_sk(sk);
3685 		overhead += sizeof(struct iphdr);
3686 		opt = rcu_dereference_protected(inet->inet_opt,
3687 						sock_owned_by_user(sk));
3688 		if (opt)
3689 			overhead += opt->opt.optlen;
3690 		return overhead;
3691 #if IS_ENABLED(CONFIG_IPV6)
3692 	case AF_INET6:
3693 		np = inet6_sk(sk);
3694 		overhead += sizeof(struct ipv6hdr);
3695 		if (np)
3696 			optv6 = rcu_dereference_protected(np->opt,
3697 							  sock_owned_by_user(sk));
3698 		if (optv6)
3699 			overhead += (optv6->opt_flen + optv6->opt_nflen);
3700 		return overhead;
3701 #endif /* IS_ENABLED(CONFIG_IPV6) */
3702 	default: /* Returns 0 overhead if the socket is not ipv4 or ipv6 */
3703 		return overhead;
3704 	}
3705 }
3706 EXPORT_SYMBOL(kernel_sock_ip_overhead);
3707