xref: /linux/net/socket.c (revision 26fbb4c8c7c3ee9a4c3b4de555a8587b5a19154e)
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/ethtool.h>
56 #include <linux/mm.h>
57 #include <linux/socket.h>
58 #include <linux/file.h>
59 #include <linux/net.h>
60 #include <linux/interrupt.h>
61 #include <linux/thread_info.h>
62 #include <linux/rcupdate.h>
63 #include <linux/netdevice.h>
64 #include <linux/proc_fs.h>
65 #include <linux/seq_file.h>
66 #include <linux/mutex.h>
67 #include <linux/if_bridge.h>
68 #include <linux/if_vlan.h>
69 #include <linux/ptp_classify.h>
70 #include <linux/init.h>
71 #include <linux/poll.h>
72 #include <linux/cache.h>
73 #include <linux/module.h>
74 #include <linux/highmem.h>
75 #include <linux/mount.h>
76 #include <linux/pseudo_fs.h>
77 #include <linux/security.h>
78 #include <linux/syscalls.h>
79 #include <linux/compat.h>
80 #include <linux/kmod.h>
81 #include <linux/audit.h>
82 #include <linux/wireless.h>
83 #include <linux/nsproxy.h>
84 #include <linux/magic.h>
85 #include <linux/slab.h>
86 #include <linux/xattr.h>
87 #include <linux/nospec.h>
88 #include <linux/indirect_call_wrapper.h>
89 
90 #include <linux/uaccess.h>
91 #include <asm/unistd.h>
92 
93 #include <net/compat.h>
94 #include <net/wext.h>
95 #include <net/cls_cgroup.h>
96 
97 #include <net/sock.h>
98 #include <linux/netfilter.h>
99 
100 #include <linux/if_tun.h>
101 #include <linux/ipv6_route.h>
102 #include <linux/route.h>
103 #include <linux/termios.h>
104 #include <linux/sockios.h>
105 #include <net/busy_poll.h>
106 #include <linux/errqueue.h>
107 
108 #ifdef CONFIG_NET_RX_BUSY_POLL
109 unsigned int sysctl_net_busy_read __read_mostly;
110 unsigned int sysctl_net_busy_poll __read_mostly;
111 #endif
112 
113 static ssize_t sock_read_iter(struct kiocb *iocb, struct iov_iter *to);
114 static ssize_t sock_write_iter(struct kiocb *iocb, struct iov_iter *from);
115 static int sock_mmap(struct file *file, struct vm_area_struct *vma);
116 
117 static int sock_close(struct inode *inode, struct file *file);
118 static __poll_t sock_poll(struct file *file,
119 			      struct poll_table_struct *wait);
120 static long sock_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
121 #ifdef CONFIG_COMPAT
122 static long compat_sock_ioctl(struct file *file,
123 			      unsigned int cmd, unsigned long arg);
124 #endif
125 static int sock_fasync(int fd, struct file *filp, int on);
126 static ssize_t sock_sendpage(struct file *file, struct page *page,
127 			     int offset, size_t size, loff_t *ppos, int more);
128 static ssize_t sock_splice_read(struct file *file, loff_t *ppos,
129 				struct pipe_inode_info *pipe, size_t len,
130 				unsigned int flags);
131 
132 #ifdef CONFIG_PROC_FS
133 static void sock_show_fdinfo(struct seq_file *m, struct file *f)
134 {
135 	struct socket *sock = f->private_data;
136 
137 	if (sock->ops->show_fdinfo)
138 		sock->ops->show_fdinfo(m, sock);
139 }
140 #else
141 #define sock_show_fdinfo NULL
142 #endif
143 
144 /*
145  *	Socket files have a set of 'special' operations as well as the generic file ones. These don't appear
146  *	in the operation structures but are done directly via the socketcall() multiplexor.
147  */
148 
149 static const struct file_operations socket_file_ops = {
150 	.owner =	THIS_MODULE,
151 	.llseek =	no_llseek,
152 	.read_iter =	sock_read_iter,
153 	.write_iter =	sock_write_iter,
154 	.poll =		sock_poll,
155 	.unlocked_ioctl = sock_ioctl,
156 #ifdef CONFIG_COMPAT
157 	.compat_ioctl = compat_sock_ioctl,
158 #endif
159 	.mmap =		sock_mmap,
160 	.release =	sock_close,
161 	.fasync =	sock_fasync,
162 	.sendpage =	sock_sendpage,
163 	.splice_write = generic_splice_sendpage,
164 	.splice_read =	sock_splice_read,
165 	.show_fdinfo =	sock_show_fdinfo,
166 };
167 
168 /*
169  *	The protocol list. Each protocol is registered in here.
170  */
171 
172 static DEFINE_SPINLOCK(net_family_lock);
173 static const struct net_proto_family __rcu *net_families[NPROTO] __read_mostly;
174 
175 /*
176  * Support routines.
177  * Move socket addresses back and forth across the kernel/user
178  * divide and look after the messy bits.
179  */
180 
181 /**
182  *	move_addr_to_kernel	-	copy a socket address into kernel space
183  *	@uaddr: Address in user space
184  *	@kaddr: Address in kernel space
185  *	@ulen: Length in user space
186  *
187  *	The address is copied into kernel space. If the provided address is
188  *	too long an error code of -EINVAL is returned. If the copy gives
189  *	invalid addresses -EFAULT is returned. On a success 0 is returned.
190  */
191 
192 int move_addr_to_kernel(void __user *uaddr, int ulen, struct sockaddr_storage *kaddr)
193 {
194 	if (ulen < 0 || ulen > sizeof(struct sockaddr_storage))
195 		return -EINVAL;
196 	if (ulen == 0)
197 		return 0;
198 	if (copy_from_user(kaddr, uaddr, ulen))
199 		return -EFAULT;
200 	return audit_sockaddr(ulen, kaddr);
201 }
202 
203 /**
204  *	move_addr_to_user	-	copy an address to user space
205  *	@kaddr: kernel space address
206  *	@klen: length of address in kernel
207  *	@uaddr: user space address
208  *	@ulen: pointer to user length field
209  *
210  *	The value pointed to by ulen on entry is the buffer length available.
211  *	This is overwritten with the buffer space used. -EINVAL is returned
212  *	if an overlong buffer is specified or a negative buffer size. -EFAULT
213  *	is returned if either the buffer or the length field are not
214  *	accessible.
215  *	After copying the data up to the limit the user specifies, the true
216  *	length of the data is written over the length limit the user
217  *	specified. Zero is returned for a success.
218  */
219 
220 static int move_addr_to_user(struct sockaddr_storage *kaddr, int klen,
221 			     void __user *uaddr, int __user *ulen)
222 {
223 	int err;
224 	int len;
225 
226 	BUG_ON(klen > sizeof(struct sockaddr_storage));
227 	err = get_user(len, ulen);
228 	if (err)
229 		return err;
230 	if (len > klen)
231 		len = klen;
232 	if (len < 0)
233 		return -EINVAL;
234 	if (len) {
235 		if (audit_sockaddr(klen, kaddr))
236 			return -ENOMEM;
237 		if (copy_to_user(uaddr, kaddr, len))
238 			return -EFAULT;
239 	}
240 	/*
241 	 *      "fromlen shall refer to the value before truncation.."
242 	 *                      1003.1g
243 	 */
244 	return __put_user(klen, ulen);
245 }
246 
247 static struct kmem_cache *sock_inode_cachep __ro_after_init;
248 
249 static struct inode *sock_alloc_inode(struct super_block *sb)
250 {
251 	struct socket_alloc *ei;
252 
253 	ei = kmem_cache_alloc(sock_inode_cachep, GFP_KERNEL);
254 	if (!ei)
255 		return NULL;
256 	init_waitqueue_head(&ei->socket.wq.wait);
257 	ei->socket.wq.fasync_list = NULL;
258 	ei->socket.wq.flags = 0;
259 
260 	ei->socket.state = SS_UNCONNECTED;
261 	ei->socket.flags = 0;
262 	ei->socket.ops = NULL;
263 	ei->socket.sk = NULL;
264 	ei->socket.file = NULL;
265 
266 	return &ei->vfs_inode;
267 }
268 
269 static void sock_free_inode(struct inode *inode)
270 {
271 	struct socket_alloc *ei;
272 
273 	ei = container_of(inode, struct socket_alloc, vfs_inode);
274 	kmem_cache_free(sock_inode_cachep, ei);
275 }
276 
277 static void init_once(void *foo)
278 {
279 	struct socket_alloc *ei = (struct socket_alloc *)foo;
280 
281 	inode_init_once(&ei->vfs_inode);
282 }
283 
284 static void init_inodecache(void)
285 {
286 	sock_inode_cachep = kmem_cache_create("sock_inode_cache",
287 					      sizeof(struct socket_alloc),
288 					      0,
289 					      (SLAB_HWCACHE_ALIGN |
290 					       SLAB_RECLAIM_ACCOUNT |
291 					       SLAB_MEM_SPREAD | SLAB_ACCOUNT),
292 					      init_once);
293 	BUG_ON(sock_inode_cachep == NULL);
294 }
295 
296 static const struct super_operations sockfs_ops = {
297 	.alloc_inode	= sock_alloc_inode,
298 	.free_inode	= sock_free_inode,
299 	.statfs		= simple_statfs,
300 };
301 
302 /*
303  * sockfs_dname() is called from d_path().
304  */
305 static char *sockfs_dname(struct dentry *dentry, char *buffer, int buflen)
306 {
307 	return dynamic_dname(dentry, buffer, buflen, "socket:[%lu]",
308 				d_inode(dentry)->i_ino);
309 }
310 
311 static const struct dentry_operations sockfs_dentry_operations = {
312 	.d_dname  = sockfs_dname,
313 };
314 
315 static int sockfs_xattr_get(const struct xattr_handler *handler,
316 			    struct dentry *dentry, struct inode *inode,
317 			    const char *suffix, void *value, size_t size)
318 {
319 	if (value) {
320 		if (dentry->d_name.len + 1 > size)
321 			return -ERANGE;
322 		memcpy(value, dentry->d_name.name, dentry->d_name.len + 1);
323 	}
324 	return dentry->d_name.len + 1;
325 }
326 
327 #define XATTR_SOCKPROTONAME_SUFFIX "sockprotoname"
328 #define XATTR_NAME_SOCKPROTONAME (XATTR_SYSTEM_PREFIX XATTR_SOCKPROTONAME_SUFFIX)
329 #define XATTR_NAME_SOCKPROTONAME_LEN (sizeof(XATTR_NAME_SOCKPROTONAME)-1)
330 
331 static const struct xattr_handler sockfs_xattr_handler = {
332 	.name = XATTR_NAME_SOCKPROTONAME,
333 	.get = sockfs_xattr_get,
334 };
335 
336 static int sockfs_security_xattr_set(const struct xattr_handler *handler,
337 				     struct dentry *dentry, struct inode *inode,
338 				     const char *suffix, const void *value,
339 				     size_t size, int flags)
340 {
341 	/* Handled by LSM. */
342 	return -EAGAIN;
343 }
344 
345 static const struct xattr_handler sockfs_security_xattr_handler = {
346 	.prefix = XATTR_SECURITY_PREFIX,
347 	.set = sockfs_security_xattr_set,
348 };
349 
350 static const struct xattr_handler *sockfs_xattr_handlers[] = {
351 	&sockfs_xattr_handler,
352 	&sockfs_security_xattr_handler,
353 	NULL
354 };
355 
356 static int sockfs_init_fs_context(struct fs_context *fc)
357 {
358 	struct pseudo_fs_context *ctx = init_pseudo(fc, SOCKFS_MAGIC);
359 	if (!ctx)
360 		return -ENOMEM;
361 	ctx->ops = &sockfs_ops;
362 	ctx->dops = &sockfs_dentry_operations;
363 	ctx->xattr = sockfs_xattr_handlers;
364 	return 0;
365 }
366 
367 static struct vfsmount *sock_mnt __read_mostly;
368 
369 static struct file_system_type sock_fs_type = {
370 	.name =		"sockfs",
371 	.init_fs_context = sockfs_init_fs_context,
372 	.kill_sb =	kill_anon_super,
373 };
374 
375 /*
376  *	Obtains the first available file descriptor and sets it up for use.
377  *
378  *	These functions create file structures and maps them to fd space
379  *	of the current process. On success it returns file descriptor
380  *	and file struct implicitly stored in sock->file.
381  *	Note that another thread may close file descriptor before we return
382  *	from this function. We use the fact that now we do not refer
383  *	to socket after mapping. If one day we will need it, this
384  *	function will increment ref. count on file by 1.
385  *
386  *	In any case returned fd MAY BE not valid!
387  *	This race condition is unavoidable
388  *	with shared fd spaces, we cannot solve it inside kernel,
389  *	but we take care of internal coherence yet.
390  */
391 
392 /**
393  *	sock_alloc_file - Bind a &socket to a &file
394  *	@sock: socket
395  *	@flags: file status flags
396  *	@dname: protocol name
397  *
398  *	Returns the &file bound with @sock, implicitly storing it
399  *	in sock->file. If dname is %NULL, sets to "".
400  *	On failure the return is a ERR pointer (see linux/err.h).
401  *	This function uses GFP_KERNEL internally.
402  */
403 
404 struct file *sock_alloc_file(struct socket *sock, int flags, const char *dname)
405 {
406 	struct file *file;
407 
408 	if (!dname)
409 		dname = sock->sk ? sock->sk->sk_prot_creator->name : "";
410 
411 	file = alloc_file_pseudo(SOCK_INODE(sock), sock_mnt, dname,
412 				O_RDWR | (flags & O_NONBLOCK),
413 				&socket_file_ops);
414 	if (IS_ERR(file)) {
415 		sock_release(sock);
416 		return file;
417 	}
418 
419 	sock->file = file;
420 	file->private_data = sock;
421 	stream_open(SOCK_INODE(sock), file);
422 	return file;
423 }
424 EXPORT_SYMBOL(sock_alloc_file);
425 
426 static int sock_map_fd(struct socket *sock, int flags)
427 {
428 	struct file *newfile;
429 	int fd = get_unused_fd_flags(flags);
430 	if (unlikely(fd < 0)) {
431 		sock_release(sock);
432 		return fd;
433 	}
434 
435 	newfile = sock_alloc_file(sock, flags, NULL);
436 	if (!IS_ERR(newfile)) {
437 		fd_install(fd, newfile);
438 		return fd;
439 	}
440 
441 	put_unused_fd(fd);
442 	return PTR_ERR(newfile);
443 }
444 
445 /**
446  *	sock_from_file - Return the &socket bounded to @file.
447  *	@file: file
448  *
449  *	On failure returns %NULL.
450  */
451 
452 struct socket *sock_from_file(struct file *file)
453 {
454 	if (file->f_op == &socket_file_ops)
455 		return file->private_data;	/* set in sock_map_fd */
456 
457 	return NULL;
458 }
459 EXPORT_SYMBOL(sock_from_file);
460 
461 /**
462  *	sockfd_lookup - Go from a file number to its socket slot
463  *	@fd: file handle
464  *	@err: pointer to an error code return
465  *
466  *	The file handle passed in is locked and the socket it is bound
467  *	to is returned. If an error occurs the err pointer is overwritten
468  *	with a negative errno code and NULL is returned. The function checks
469  *	for both invalid handles and passing a handle which is not a socket.
470  *
471  *	On a success the socket object pointer is returned.
472  */
473 
474 struct socket *sockfd_lookup(int fd, int *err)
475 {
476 	struct file *file;
477 	struct socket *sock;
478 
479 	file = fget(fd);
480 	if (!file) {
481 		*err = -EBADF;
482 		return NULL;
483 	}
484 
485 	sock = sock_from_file(file);
486 	if (!sock) {
487 		*err = -ENOTSOCK;
488 		fput(file);
489 	}
490 	return sock;
491 }
492 EXPORT_SYMBOL(sockfd_lookup);
493 
494 static struct socket *sockfd_lookup_light(int fd, int *err, int *fput_needed)
495 {
496 	struct fd f = fdget(fd);
497 	struct socket *sock;
498 
499 	*err = -EBADF;
500 	if (f.file) {
501 		sock = sock_from_file(f.file);
502 		if (likely(sock)) {
503 			*fput_needed = f.flags & FDPUT_FPUT;
504 			return sock;
505 		}
506 		*err = -ENOTSOCK;
507 		fdput(f);
508 	}
509 	return NULL;
510 }
511 
512 static ssize_t sockfs_listxattr(struct dentry *dentry, char *buffer,
513 				size_t size)
514 {
515 	ssize_t len;
516 	ssize_t used = 0;
517 
518 	len = security_inode_listsecurity(d_inode(dentry), buffer, size);
519 	if (len < 0)
520 		return len;
521 	used += len;
522 	if (buffer) {
523 		if (size < used)
524 			return -ERANGE;
525 		buffer += len;
526 	}
527 
528 	len = (XATTR_NAME_SOCKPROTONAME_LEN + 1);
529 	used += len;
530 	if (buffer) {
531 		if (size < used)
532 			return -ERANGE;
533 		memcpy(buffer, XATTR_NAME_SOCKPROTONAME, len);
534 		buffer += len;
535 	}
536 
537 	return used;
538 }
539 
540 static int sockfs_setattr(struct dentry *dentry, struct iattr *iattr)
541 {
542 	int err = simple_setattr(dentry, iattr);
543 
544 	if (!err && (iattr->ia_valid & ATTR_UID)) {
545 		struct socket *sock = SOCKET_I(d_inode(dentry));
546 
547 		if (sock->sk)
548 			sock->sk->sk_uid = iattr->ia_uid;
549 		else
550 			err = -ENOENT;
551 	}
552 
553 	return err;
554 }
555 
556 static const struct inode_operations sockfs_inode_ops = {
557 	.listxattr = sockfs_listxattr,
558 	.setattr = sockfs_setattr,
559 };
560 
561 /**
562  *	sock_alloc - allocate a socket
563  *
564  *	Allocate a new inode and socket object. The two are bound together
565  *	and initialised. The socket is then returned. If we are out of inodes
566  *	NULL is returned. This functions uses GFP_KERNEL internally.
567  */
568 
569 struct socket *sock_alloc(void)
570 {
571 	struct inode *inode;
572 	struct socket *sock;
573 
574 	inode = new_inode_pseudo(sock_mnt->mnt_sb);
575 	if (!inode)
576 		return NULL;
577 
578 	sock = SOCKET_I(inode);
579 
580 	inode->i_ino = get_next_ino();
581 	inode->i_mode = S_IFSOCK | S_IRWXUGO;
582 	inode->i_uid = current_fsuid();
583 	inode->i_gid = current_fsgid();
584 	inode->i_op = &sockfs_inode_ops;
585 
586 	return sock;
587 }
588 EXPORT_SYMBOL(sock_alloc);
589 
590 static void __sock_release(struct socket *sock, struct inode *inode)
591 {
592 	if (sock->ops) {
593 		struct module *owner = sock->ops->owner;
594 
595 		if (inode)
596 			inode_lock(inode);
597 		sock->ops->release(sock);
598 		sock->sk = NULL;
599 		if (inode)
600 			inode_unlock(inode);
601 		sock->ops = NULL;
602 		module_put(owner);
603 	}
604 
605 	if (sock->wq.fasync_list)
606 		pr_err("%s: fasync list not empty!\n", __func__);
607 
608 	if (!sock->file) {
609 		iput(SOCK_INODE(sock));
610 		return;
611 	}
612 	sock->file = NULL;
613 }
614 
615 /**
616  *	sock_release - close a socket
617  *	@sock: socket to close
618  *
619  *	The socket is released from the protocol stack if it has a release
620  *	callback, and the inode is then released if the socket is bound to
621  *	an inode not a file.
622  */
623 void sock_release(struct socket *sock)
624 {
625 	__sock_release(sock, NULL);
626 }
627 EXPORT_SYMBOL(sock_release);
628 
629 void __sock_tx_timestamp(__u16 tsflags, __u8 *tx_flags)
630 {
631 	u8 flags = *tx_flags;
632 
633 	if (tsflags & SOF_TIMESTAMPING_TX_HARDWARE)
634 		flags |= SKBTX_HW_TSTAMP;
635 
636 	if (tsflags & SOF_TIMESTAMPING_TX_SOFTWARE)
637 		flags |= SKBTX_SW_TSTAMP;
638 
639 	if (tsflags & SOF_TIMESTAMPING_TX_SCHED)
640 		flags |= SKBTX_SCHED_TSTAMP;
641 
642 	*tx_flags = flags;
643 }
644 EXPORT_SYMBOL(__sock_tx_timestamp);
645 
646 INDIRECT_CALLABLE_DECLARE(int inet_sendmsg(struct socket *, struct msghdr *,
647 					   size_t));
648 INDIRECT_CALLABLE_DECLARE(int inet6_sendmsg(struct socket *, struct msghdr *,
649 					    size_t));
650 static inline int sock_sendmsg_nosec(struct socket *sock, struct msghdr *msg)
651 {
652 	int ret = INDIRECT_CALL_INET(sock->ops->sendmsg, inet6_sendmsg,
653 				     inet_sendmsg, sock, msg,
654 				     msg_data_left(msg));
655 	BUG_ON(ret == -EIOCBQUEUED);
656 	return ret;
657 }
658 
659 /**
660  *	sock_sendmsg - send a message through @sock
661  *	@sock: socket
662  *	@msg: message to send
663  *
664  *	Sends @msg through @sock, passing through LSM.
665  *	Returns the number of bytes sent, or an error code.
666  */
667 int sock_sendmsg(struct socket *sock, struct msghdr *msg)
668 {
669 	int err = security_socket_sendmsg(sock, msg,
670 					  msg_data_left(msg));
671 
672 	return err ?: sock_sendmsg_nosec(sock, msg);
673 }
674 EXPORT_SYMBOL(sock_sendmsg);
675 
676 /**
677  *	kernel_sendmsg - send a message through @sock (kernel-space)
678  *	@sock: socket
679  *	@msg: message header
680  *	@vec: kernel vec
681  *	@num: vec array length
682  *	@size: total message data size
683  *
684  *	Builds the message data with @vec and sends it through @sock.
685  *	Returns the number of bytes sent, or an error code.
686  */
687 
688 int kernel_sendmsg(struct socket *sock, struct msghdr *msg,
689 		   struct kvec *vec, size_t num, size_t size)
690 {
691 	iov_iter_kvec(&msg->msg_iter, WRITE, vec, num, size);
692 	return sock_sendmsg(sock, msg);
693 }
694 EXPORT_SYMBOL(kernel_sendmsg);
695 
696 /**
697  *	kernel_sendmsg_locked - send a message through @sock (kernel-space)
698  *	@sk: sock
699  *	@msg: message header
700  *	@vec: output s/g array
701  *	@num: output s/g array length
702  *	@size: total message data size
703  *
704  *	Builds the message data with @vec and sends it through @sock.
705  *	Returns the number of bytes sent, or an error code.
706  *	Caller must hold @sk.
707  */
708 
709 int kernel_sendmsg_locked(struct sock *sk, struct msghdr *msg,
710 			  struct kvec *vec, size_t num, size_t size)
711 {
712 	struct socket *sock = sk->sk_socket;
713 
714 	if (!sock->ops->sendmsg_locked)
715 		return sock_no_sendmsg_locked(sk, msg, size);
716 
717 	iov_iter_kvec(&msg->msg_iter, WRITE, vec, num, size);
718 
719 	return sock->ops->sendmsg_locked(sk, msg, msg_data_left(msg));
720 }
721 EXPORT_SYMBOL(kernel_sendmsg_locked);
722 
723 static bool skb_is_err_queue(const struct sk_buff *skb)
724 {
725 	/* pkt_type of skbs enqueued on the error queue are set to
726 	 * PACKET_OUTGOING in skb_set_err_queue(). This is only safe to do
727 	 * in recvmsg, since skbs received on a local socket will never
728 	 * have a pkt_type of PACKET_OUTGOING.
729 	 */
730 	return skb->pkt_type == PACKET_OUTGOING;
731 }
732 
733 /* On transmit, software and hardware timestamps are returned independently.
734  * As the two skb clones share the hardware timestamp, which may be updated
735  * before the software timestamp is received, a hardware TX timestamp may be
736  * returned only if there is no software TX timestamp. Ignore false software
737  * timestamps, which may be made in the __sock_recv_timestamp() call when the
738  * option SO_TIMESTAMP_OLD(NS) is enabled on the socket, even when the skb has a
739  * hardware timestamp.
740  */
741 static bool skb_is_swtx_tstamp(const struct sk_buff *skb, int false_tstamp)
742 {
743 	return skb->tstamp && !false_tstamp && skb_is_err_queue(skb);
744 }
745 
746 static void put_ts_pktinfo(struct msghdr *msg, struct sk_buff *skb)
747 {
748 	struct scm_ts_pktinfo ts_pktinfo;
749 	struct net_device *orig_dev;
750 
751 	if (!skb_mac_header_was_set(skb))
752 		return;
753 
754 	memset(&ts_pktinfo, 0, sizeof(ts_pktinfo));
755 
756 	rcu_read_lock();
757 	orig_dev = dev_get_by_napi_id(skb_napi_id(skb));
758 	if (orig_dev)
759 		ts_pktinfo.if_index = orig_dev->ifindex;
760 	rcu_read_unlock();
761 
762 	ts_pktinfo.pkt_length = skb->len - skb_mac_offset(skb);
763 	put_cmsg(msg, SOL_SOCKET, SCM_TIMESTAMPING_PKTINFO,
764 		 sizeof(ts_pktinfo), &ts_pktinfo);
765 }
766 
767 /*
768  * called from sock_recv_timestamp() if sock_flag(sk, SOCK_RCVTSTAMP)
769  */
770 void __sock_recv_timestamp(struct msghdr *msg, struct sock *sk,
771 	struct sk_buff *skb)
772 {
773 	int need_software_tstamp = sock_flag(sk, SOCK_RCVTSTAMP);
774 	int new_tstamp = sock_flag(sk, SOCK_TSTAMP_NEW);
775 	struct scm_timestamping_internal tss;
776 
777 	int empty = 1, false_tstamp = 0;
778 	struct skb_shared_hwtstamps *shhwtstamps =
779 		skb_hwtstamps(skb);
780 
781 	/* Race occurred between timestamp enabling and packet
782 	   receiving.  Fill in the current time for now. */
783 	if (need_software_tstamp && skb->tstamp == 0) {
784 		__net_timestamp(skb);
785 		false_tstamp = 1;
786 	}
787 
788 	if (need_software_tstamp) {
789 		if (!sock_flag(sk, SOCK_RCVTSTAMPNS)) {
790 			if (new_tstamp) {
791 				struct __kernel_sock_timeval tv;
792 
793 				skb_get_new_timestamp(skb, &tv);
794 				put_cmsg(msg, SOL_SOCKET, SO_TIMESTAMP_NEW,
795 					 sizeof(tv), &tv);
796 			} else {
797 				struct __kernel_old_timeval tv;
798 
799 				skb_get_timestamp(skb, &tv);
800 				put_cmsg(msg, SOL_SOCKET, SO_TIMESTAMP_OLD,
801 					 sizeof(tv), &tv);
802 			}
803 		} else {
804 			if (new_tstamp) {
805 				struct __kernel_timespec ts;
806 
807 				skb_get_new_timestampns(skb, &ts);
808 				put_cmsg(msg, SOL_SOCKET, SO_TIMESTAMPNS_NEW,
809 					 sizeof(ts), &ts);
810 			} else {
811 				struct __kernel_old_timespec ts;
812 
813 				skb_get_timestampns(skb, &ts);
814 				put_cmsg(msg, SOL_SOCKET, SO_TIMESTAMPNS_OLD,
815 					 sizeof(ts), &ts);
816 			}
817 		}
818 	}
819 
820 	memset(&tss, 0, sizeof(tss));
821 	if ((sk->sk_tsflags & SOF_TIMESTAMPING_SOFTWARE) &&
822 	    ktime_to_timespec64_cond(skb->tstamp, tss.ts + 0))
823 		empty = 0;
824 	if (shhwtstamps &&
825 	    (sk->sk_tsflags & SOF_TIMESTAMPING_RAW_HARDWARE) &&
826 	    !skb_is_swtx_tstamp(skb, false_tstamp) &&
827 	    ktime_to_timespec64_cond(shhwtstamps->hwtstamp, tss.ts + 2)) {
828 		empty = 0;
829 		if ((sk->sk_tsflags & SOF_TIMESTAMPING_OPT_PKTINFO) &&
830 		    !skb_is_err_queue(skb))
831 			put_ts_pktinfo(msg, skb);
832 	}
833 	if (!empty) {
834 		if (sock_flag(sk, SOCK_TSTAMP_NEW))
835 			put_cmsg_scm_timestamping64(msg, &tss);
836 		else
837 			put_cmsg_scm_timestamping(msg, &tss);
838 
839 		if (skb_is_err_queue(skb) && skb->len &&
840 		    SKB_EXT_ERR(skb)->opt_stats)
841 			put_cmsg(msg, SOL_SOCKET, SCM_TIMESTAMPING_OPT_STATS,
842 				 skb->len, skb->data);
843 	}
844 }
845 EXPORT_SYMBOL_GPL(__sock_recv_timestamp);
846 
847 void __sock_recv_wifi_status(struct msghdr *msg, struct sock *sk,
848 	struct sk_buff *skb)
849 {
850 	int ack;
851 
852 	if (!sock_flag(sk, SOCK_WIFI_STATUS))
853 		return;
854 	if (!skb->wifi_acked_valid)
855 		return;
856 
857 	ack = skb->wifi_acked;
858 
859 	put_cmsg(msg, SOL_SOCKET, SCM_WIFI_STATUS, sizeof(ack), &ack);
860 }
861 EXPORT_SYMBOL_GPL(__sock_recv_wifi_status);
862 
863 static inline void sock_recv_drops(struct msghdr *msg, struct sock *sk,
864 				   struct sk_buff *skb)
865 {
866 	if (sock_flag(sk, SOCK_RXQ_OVFL) && skb && SOCK_SKB_CB(skb)->dropcount)
867 		put_cmsg(msg, SOL_SOCKET, SO_RXQ_OVFL,
868 			sizeof(__u32), &SOCK_SKB_CB(skb)->dropcount);
869 }
870 
871 void __sock_recv_ts_and_drops(struct msghdr *msg, struct sock *sk,
872 	struct sk_buff *skb)
873 {
874 	sock_recv_timestamp(msg, sk, skb);
875 	sock_recv_drops(msg, sk, skb);
876 }
877 EXPORT_SYMBOL_GPL(__sock_recv_ts_and_drops);
878 
879 INDIRECT_CALLABLE_DECLARE(int inet_recvmsg(struct socket *, struct msghdr *,
880 					   size_t, int));
881 INDIRECT_CALLABLE_DECLARE(int inet6_recvmsg(struct socket *, struct msghdr *,
882 					    size_t, int));
883 static inline int sock_recvmsg_nosec(struct socket *sock, struct msghdr *msg,
884 				     int flags)
885 {
886 	return INDIRECT_CALL_INET(sock->ops->recvmsg, inet6_recvmsg,
887 				  inet_recvmsg, sock, msg, msg_data_left(msg),
888 				  flags);
889 }
890 
891 /**
892  *	sock_recvmsg - receive a message from @sock
893  *	@sock: socket
894  *	@msg: message to receive
895  *	@flags: message flags
896  *
897  *	Receives @msg from @sock, passing through LSM. Returns the total number
898  *	of bytes received, or an error.
899  */
900 int sock_recvmsg(struct socket *sock, struct msghdr *msg, int flags)
901 {
902 	int err = security_socket_recvmsg(sock, msg, msg_data_left(msg), flags);
903 
904 	return err ?: sock_recvmsg_nosec(sock, msg, flags);
905 }
906 EXPORT_SYMBOL(sock_recvmsg);
907 
908 /**
909  *	kernel_recvmsg - Receive a message from a socket (kernel space)
910  *	@sock: The socket to receive the message from
911  *	@msg: Received message
912  *	@vec: Input s/g array for message data
913  *	@num: Size of input s/g array
914  *	@size: Number of bytes to read
915  *	@flags: Message flags (MSG_DONTWAIT, etc...)
916  *
917  *	On return the msg structure contains the scatter/gather array passed in the
918  *	vec argument. The array is modified so that it consists of the unfilled
919  *	portion of the original array.
920  *
921  *	The returned value is the total number of bytes received, or an error.
922  */
923 
924 int kernel_recvmsg(struct socket *sock, struct msghdr *msg,
925 		   struct kvec *vec, size_t num, size_t size, int flags)
926 {
927 	msg->msg_control_is_user = false;
928 	iov_iter_kvec(&msg->msg_iter, READ, vec, num, size);
929 	return sock_recvmsg(sock, msg, flags);
930 }
931 EXPORT_SYMBOL(kernel_recvmsg);
932 
933 static ssize_t sock_sendpage(struct file *file, struct page *page,
934 			     int offset, size_t size, loff_t *ppos, int more)
935 {
936 	struct socket *sock;
937 	int flags;
938 
939 	sock = file->private_data;
940 
941 	flags = (file->f_flags & O_NONBLOCK) ? MSG_DONTWAIT : 0;
942 	/* more is a combination of MSG_MORE and MSG_SENDPAGE_NOTLAST */
943 	flags |= more;
944 
945 	return kernel_sendpage(sock, page, offset, size, flags);
946 }
947 
948 static ssize_t sock_splice_read(struct file *file, loff_t *ppos,
949 				struct pipe_inode_info *pipe, size_t len,
950 				unsigned int flags)
951 {
952 	struct socket *sock = file->private_data;
953 
954 	if (unlikely(!sock->ops->splice_read))
955 		return generic_file_splice_read(file, ppos, pipe, len, flags);
956 
957 	return sock->ops->splice_read(sock, ppos, pipe, len, flags);
958 }
959 
960 static ssize_t sock_read_iter(struct kiocb *iocb, struct iov_iter *to)
961 {
962 	struct file *file = iocb->ki_filp;
963 	struct socket *sock = file->private_data;
964 	struct msghdr msg = {.msg_iter = *to,
965 			     .msg_iocb = iocb};
966 	ssize_t res;
967 
968 	if (file->f_flags & O_NONBLOCK || (iocb->ki_flags & IOCB_NOWAIT))
969 		msg.msg_flags = MSG_DONTWAIT;
970 
971 	if (iocb->ki_pos != 0)
972 		return -ESPIPE;
973 
974 	if (!iov_iter_count(to))	/* Match SYS5 behaviour */
975 		return 0;
976 
977 	res = sock_recvmsg(sock, &msg, msg.msg_flags);
978 	*to = msg.msg_iter;
979 	return res;
980 }
981 
982 static ssize_t sock_write_iter(struct kiocb *iocb, struct iov_iter *from)
983 {
984 	struct file *file = iocb->ki_filp;
985 	struct socket *sock = file->private_data;
986 	struct msghdr msg = {.msg_iter = *from,
987 			     .msg_iocb = iocb};
988 	ssize_t res;
989 
990 	if (iocb->ki_pos != 0)
991 		return -ESPIPE;
992 
993 	if (file->f_flags & O_NONBLOCK || (iocb->ki_flags & IOCB_NOWAIT))
994 		msg.msg_flags = MSG_DONTWAIT;
995 
996 	if (sock->type == SOCK_SEQPACKET)
997 		msg.msg_flags |= MSG_EOR;
998 
999 	res = sock_sendmsg(sock, &msg);
1000 	*from = msg.msg_iter;
1001 	return res;
1002 }
1003 
1004 /*
1005  * Atomic setting of ioctl hooks to avoid race
1006  * with module unload.
1007  */
1008 
1009 static DEFINE_MUTEX(br_ioctl_mutex);
1010 static int (*br_ioctl_hook) (struct net *, unsigned int cmd, void __user *arg);
1011 
1012 void brioctl_set(int (*hook) (struct net *, unsigned int, void __user *))
1013 {
1014 	mutex_lock(&br_ioctl_mutex);
1015 	br_ioctl_hook = hook;
1016 	mutex_unlock(&br_ioctl_mutex);
1017 }
1018 EXPORT_SYMBOL(brioctl_set);
1019 
1020 static DEFINE_MUTEX(vlan_ioctl_mutex);
1021 static int (*vlan_ioctl_hook) (struct net *, void __user *arg);
1022 
1023 void vlan_ioctl_set(int (*hook) (struct net *, void __user *))
1024 {
1025 	mutex_lock(&vlan_ioctl_mutex);
1026 	vlan_ioctl_hook = hook;
1027 	mutex_unlock(&vlan_ioctl_mutex);
1028 }
1029 EXPORT_SYMBOL(vlan_ioctl_set);
1030 
1031 static long sock_do_ioctl(struct net *net, struct socket *sock,
1032 			  unsigned int cmd, unsigned long arg)
1033 {
1034 	int err;
1035 	void __user *argp = (void __user *)arg;
1036 
1037 	err = sock->ops->ioctl(sock, cmd, arg);
1038 
1039 	/*
1040 	 * If this ioctl is unknown try to hand it down
1041 	 * to the NIC driver.
1042 	 */
1043 	if (err != -ENOIOCTLCMD)
1044 		return err;
1045 
1046 	if (cmd == SIOCGIFCONF) {
1047 		struct ifconf ifc;
1048 		if (copy_from_user(&ifc, argp, sizeof(struct ifconf)))
1049 			return -EFAULT;
1050 		rtnl_lock();
1051 		err = dev_ifconf(net, &ifc, sizeof(struct ifreq));
1052 		rtnl_unlock();
1053 		if (!err && copy_to_user(argp, &ifc, sizeof(struct ifconf)))
1054 			err = -EFAULT;
1055 	} else {
1056 		struct ifreq ifr;
1057 		bool need_copyout;
1058 		if (copy_from_user(&ifr, argp, sizeof(struct ifreq)))
1059 			return -EFAULT;
1060 		err = dev_ioctl(net, cmd, &ifr, &need_copyout);
1061 		if (!err && need_copyout)
1062 			if (copy_to_user(argp, &ifr, sizeof(struct ifreq)))
1063 				return -EFAULT;
1064 	}
1065 	return err;
1066 }
1067 
1068 /*
1069  *	With an ioctl, arg may well be a user mode pointer, but we don't know
1070  *	what to do with it - that's up to the protocol still.
1071  */
1072 
1073 /**
1074  *	get_net_ns - increment the refcount of the network namespace
1075  *	@ns: common namespace (net)
1076  *
1077  *	Returns the net's common namespace.
1078  */
1079 
1080 struct ns_common *get_net_ns(struct ns_common *ns)
1081 {
1082 	return &get_net(container_of(ns, struct net, ns))->ns;
1083 }
1084 EXPORT_SYMBOL_GPL(get_net_ns);
1085 
1086 static long sock_ioctl(struct file *file, unsigned cmd, unsigned long arg)
1087 {
1088 	struct socket *sock;
1089 	struct sock *sk;
1090 	void __user *argp = (void __user *)arg;
1091 	int pid, err;
1092 	struct net *net;
1093 
1094 	sock = file->private_data;
1095 	sk = sock->sk;
1096 	net = sock_net(sk);
1097 	if (unlikely(cmd >= SIOCDEVPRIVATE && cmd <= (SIOCDEVPRIVATE + 15))) {
1098 		struct ifreq ifr;
1099 		bool need_copyout;
1100 		if (copy_from_user(&ifr, argp, sizeof(struct ifreq)))
1101 			return -EFAULT;
1102 		err = dev_ioctl(net, cmd, &ifr, &need_copyout);
1103 		if (!err && need_copyout)
1104 			if (copy_to_user(argp, &ifr, sizeof(struct ifreq)))
1105 				return -EFAULT;
1106 	} else
1107 #ifdef CONFIG_WEXT_CORE
1108 	if (cmd >= SIOCIWFIRST && cmd <= SIOCIWLAST) {
1109 		err = wext_handle_ioctl(net, cmd, argp);
1110 	} else
1111 #endif
1112 		switch (cmd) {
1113 		case FIOSETOWN:
1114 		case SIOCSPGRP:
1115 			err = -EFAULT;
1116 			if (get_user(pid, (int __user *)argp))
1117 				break;
1118 			err = f_setown(sock->file, pid, 1);
1119 			break;
1120 		case FIOGETOWN:
1121 		case SIOCGPGRP:
1122 			err = put_user(f_getown(sock->file),
1123 				       (int __user *)argp);
1124 			break;
1125 		case SIOCGIFBR:
1126 		case SIOCSIFBR:
1127 		case SIOCBRADDBR:
1128 		case SIOCBRDELBR:
1129 			err = -ENOPKG;
1130 			if (!br_ioctl_hook)
1131 				request_module("bridge");
1132 
1133 			mutex_lock(&br_ioctl_mutex);
1134 			if (br_ioctl_hook)
1135 				err = br_ioctl_hook(net, cmd, argp);
1136 			mutex_unlock(&br_ioctl_mutex);
1137 			break;
1138 		case SIOCGIFVLAN:
1139 		case SIOCSIFVLAN:
1140 			err = -ENOPKG;
1141 			if (!vlan_ioctl_hook)
1142 				request_module("8021q");
1143 
1144 			mutex_lock(&vlan_ioctl_mutex);
1145 			if (vlan_ioctl_hook)
1146 				err = vlan_ioctl_hook(net, argp);
1147 			mutex_unlock(&vlan_ioctl_mutex);
1148 			break;
1149 		case SIOCGSKNS:
1150 			err = -EPERM;
1151 			if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1152 				break;
1153 
1154 			err = open_related_ns(&net->ns, get_net_ns);
1155 			break;
1156 		case SIOCGSTAMP_OLD:
1157 		case SIOCGSTAMPNS_OLD:
1158 			if (!sock->ops->gettstamp) {
1159 				err = -ENOIOCTLCMD;
1160 				break;
1161 			}
1162 			err = sock->ops->gettstamp(sock, argp,
1163 						   cmd == SIOCGSTAMP_OLD,
1164 						   !IS_ENABLED(CONFIG_64BIT));
1165 			break;
1166 		case SIOCGSTAMP_NEW:
1167 		case SIOCGSTAMPNS_NEW:
1168 			if (!sock->ops->gettstamp) {
1169 				err = -ENOIOCTLCMD;
1170 				break;
1171 			}
1172 			err = sock->ops->gettstamp(sock, argp,
1173 						   cmd == SIOCGSTAMP_NEW,
1174 						   false);
1175 			break;
1176 		default:
1177 			err = sock_do_ioctl(net, sock, cmd, arg);
1178 			break;
1179 		}
1180 	return err;
1181 }
1182 
1183 /**
1184  *	sock_create_lite - creates a socket
1185  *	@family: protocol family (AF_INET, ...)
1186  *	@type: communication type (SOCK_STREAM, ...)
1187  *	@protocol: protocol (0, ...)
1188  *	@res: new socket
1189  *
1190  *	Creates a new socket and assigns it to @res, passing through LSM.
1191  *	The new socket initialization is not complete, see kernel_accept().
1192  *	Returns 0 or an error. On failure @res is set to %NULL.
1193  *	This function internally uses GFP_KERNEL.
1194  */
1195 
1196 int sock_create_lite(int family, int type, int protocol, struct socket **res)
1197 {
1198 	int err;
1199 	struct socket *sock = NULL;
1200 
1201 	err = security_socket_create(family, type, protocol, 1);
1202 	if (err)
1203 		goto out;
1204 
1205 	sock = sock_alloc();
1206 	if (!sock) {
1207 		err = -ENOMEM;
1208 		goto out;
1209 	}
1210 
1211 	sock->type = type;
1212 	err = security_socket_post_create(sock, family, type, protocol, 1);
1213 	if (err)
1214 		goto out_release;
1215 
1216 out:
1217 	*res = sock;
1218 	return err;
1219 out_release:
1220 	sock_release(sock);
1221 	sock = NULL;
1222 	goto out;
1223 }
1224 EXPORT_SYMBOL(sock_create_lite);
1225 
1226 /* No kernel lock held - perfect */
1227 static __poll_t sock_poll(struct file *file, poll_table *wait)
1228 {
1229 	struct socket *sock = file->private_data;
1230 	__poll_t events = poll_requested_events(wait), flag = 0;
1231 
1232 	if (!sock->ops->poll)
1233 		return 0;
1234 
1235 	if (sk_can_busy_loop(sock->sk)) {
1236 		/* poll once if requested by the syscall */
1237 		if (events & POLL_BUSY_LOOP)
1238 			sk_busy_loop(sock->sk, 1);
1239 
1240 		/* if this socket can poll_ll, tell the system call */
1241 		flag = POLL_BUSY_LOOP;
1242 	}
1243 
1244 	return sock->ops->poll(file, sock, wait) | flag;
1245 }
1246 
1247 static int sock_mmap(struct file *file, struct vm_area_struct *vma)
1248 {
1249 	struct socket *sock = file->private_data;
1250 
1251 	return sock->ops->mmap(file, sock, vma);
1252 }
1253 
1254 static int sock_close(struct inode *inode, struct file *filp)
1255 {
1256 	__sock_release(SOCKET_I(inode), inode);
1257 	return 0;
1258 }
1259 
1260 /*
1261  *	Update the socket async list
1262  *
1263  *	Fasync_list locking strategy.
1264  *
1265  *	1. fasync_list is modified only under process context socket lock
1266  *	   i.e. under semaphore.
1267  *	2. fasync_list is used under read_lock(&sk->sk_callback_lock)
1268  *	   or under socket lock
1269  */
1270 
1271 static int sock_fasync(int fd, struct file *filp, int on)
1272 {
1273 	struct socket *sock = filp->private_data;
1274 	struct sock *sk = sock->sk;
1275 	struct socket_wq *wq = &sock->wq;
1276 
1277 	if (sk == NULL)
1278 		return -EINVAL;
1279 
1280 	lock_sock(sk);
1281 	fasync_helper(fd, filp, on, &wq->fasync_list);
1282 
1283 	if (!wq->fasync_list)
1284 		sock_reset_flag(sk, SOCK_FASYNC);
1285 	else
1286 		sock_set_flag(sk, SOCK_FASYNC);
1287 
1288 	release_sock(sk);
1289 	return 0;
1290 }
1291 
1292 /* This function may be called only under rcu_lock */
1293 
1294 int sock_wake_async(struct socket_wq *wq, int how, int band)
1295 {
1296 	if (!wq || !wq->fasync_list)
1297 		return -1;
1298 
1299 	switch (how) {
1300 	case SOCK_WAKE_WAITD:
1301 		if (test_bit(SOCKWQ_ASYNC_WAITDATA, &wq->flags))
1302 			break;
1303 		goto call_kill;
1304 	case SOCK_WAKE_SPACE:
1305 		if (!test_and_clear_bit(SOCKWQ_ASYNC_NOSPACE, &wq->flags))
1306 			break;
1307 		fallthrough;
1308 	case SOCK_WAKE_IO:
1309 call_kill:
1310 		kill_fasync(&wq->fasync_list, SIGIO, band);
1311 		break;
1312 	case SOCK_WAKE_URG:
1313 		kill_fasync(&wq->fasync_list, SIGURG, band);
1314 	}
1315 
1316 	return 0;
1317 }
1318 EXPORT_SYMBOL(sock_wake_async);
1319 
1320 /**
1321  *	__sock_create - creates a socket
1322  *	@net: net namespace
1323  *	@family: protocol family (AF_INET, ...)
1324  *	@type: communication type (SOCK_STREAM, ...)
1325  *	@protocol: protocol (0, ...)
1326  *	@res: new socket
1327  *	@kern: boolean for kernel space sockets
1328  *
1329  *	Creates a new socket and assigns it to @res, passing through LSM.
1330  *	Returns 0 or an error. On failure @res is set to %NULL. @kern must
1331  *	be set to true if the socket resides in kernel space.
1332  *	This function internally uses GFP_KERNEL.
1333  */
1334 
1335 int __sock_create(struct net *net, int family, int type, int protocol,
1336 			 struct socket **res, int kern)
1337 {
1338 	int err;
1339 	struct socket *sock;
1340 	const struct net_proto_family *pf;
1341 
1342 	/*
1343 	 *      Check protocol is in range
1344 	 */
1345 	if (family < 0 || family >= NPROTO)
1346 		return -EAFNOSUPPORT;
1347 	if (type < 0 || type >= SOCK_MAX)
1348 		return -EINVAL;
1349 
1350 	/* Compatibility.
1351 
1352 	   This uglymoron is moved from INET layer to here to avoid
1353 	   deadlock in module load.
1354 	 */
1355 	if (family == PF_INET && type == SOCK_PACKET) {
1356 		pr_info_once("%s uses obsolete (PF_INET,SOCK_PACKET)\n",
1357 			     current->comm);
1358 		family = PF_PACKET;
1359 	}
1360 
1361 	err = security_socket_create(family, type, protocol, kern);
1362 	if (err)
1363 		return err;
1364 
1365 	/*
1366 	 *	Allocate the socket and allow the family to set things up. if
1367 	 *	the protocol is 0, the family is instructed to select an appropriate
1368 	 *	default.
1369 	 */
1370 	sock = sock_alloc();
1371 	if (!sock) {
1372 		net_warn_ratelimited("socket: no more sockets\n");
1373 		return -ENFILE;	/* Not exactly a match, but its the
1374 				   closest posix thing */
1375 	}
1376 
1377 	sock->type = type;
1378 
1379 #ifdef CONFIG_MODULES
1380 	/* Attempt to load a protocol module if the find failed.
1381 	 *
1382 	 * 12/09/1996 Marcin: But! this makes REALLY only sense, if the user
1383 	 * requested real, full-featured networking support upon configuration.
1384 	 * Otherwise module support will break!
1385 	 */
1386 	if (rcu_access_pointer(net_families[family]) == NULL)
1387 		request_module("net-pf-%d", family);
1388 #endif
1389 
1390 	rcu_read_lock();
1391 	pf = rcu_dereference(net_families[family]);
1392 	err = -EAFNOSUPPORT;
1393 	if (!pf)
1394 		goto out_release;
1395 
1396 	/*
1397 	 * We will call the ->create function, that possibly is in a loadable
1398 	 * module, so we have to bump that loadable module refcnt first.
1399 	 */
1400 	if (!try_module_get(pf->owner))
1401 		goto out_release;
1402 
1403 	/* Now protected by module ref count */
1404 	rcu_read_unlock();
1405 
1406 	err = pf->create(net, sock, protocol, kern);
1407 	if (err < 0)
1408 		goto out_module_put;
1409 
1410 	/*
1411 	 * Now to bump the refcnt of the [loadable] module that owns this
1412 	 * socket at sock_release time we decrement its refcnt.
1413 	 */
1414 	if (!try_module_get(sock->ops->owner))
1415 		goto out_module_busy;
1416 
1417 	/*
1418 	 * Now that we're done with the ->create function, the [loadable]
1419 	 * module can have its refcnt decremented
1420 	 */
1421 	module_put(pf->owner);
1422 	err = security_socket_post_create(sock, family, type, protocol, kern);
1423 	if (err)
1424 		goto out_sock_release;
1425 	*res = sock;
1426 
1427 	return 0;
1428 
1429 out_module_busy:
1430 	err = -EAFNOSUPPORT;
1431 out_module_put:
1432 	sock->ops = NULL;
1433 	module_put(pf->owner);
1434 out_sock_release:
1435 	sock_release(sock);
1436 	return err;
1437 
1438 out_release:
1439 	rcu_read_unlock();
1440 	goto out_sock_release;
1441 }
1442 EXPORT_SYMBOL(__sock_create);
1443 
1444 /**
1445  *	sock_create - creates a socket
1446  *	@family: protocol family (AF_INET, ...)
1447  *	@type: communication type (SOCK_STREAM, ...)
1448  *	@protocol: protocol (0, ...)
1449  *	@res: new socket
1450  *
1451  *	A wrapper around __sock_create().
1452  *	Returns 0 or an error. This function internally uses GFP_KERNEL.
1453  */
1454 
1455 int sock_create(int family, int type, int protocol, struct socket **res)
1456 {
1457 	return __sock_create(current->nsproxy->net_ns, family, type, protocol, res, 0);
1458 }
1459 EXPORT_SYMBOL(sock_create);
1460 
1461 /**
1462  *	sock_create_kern - creates a socket (kernel space)
1463  *	@net: net namespace
1464  *	@family: protocol family (AF_INET, ...)
1465  *	@type: communication type (SOCK_STREAM, ...)
1466  *	@protocol: protocol (0, ...)
1467  *	@res: new socket
1468  *
1469  *	A wrapper around __sock_create().
1470  *	Returns 0 or an error. This function internally uses GFP_KERNEL.
1471  */
1472 
1473 int sock_create_kern(struct net *net, int family, int type, int protocol, struct socket **res)
1474 {
1475 	return __sock_create(net, family, type, protocol, res, 1);
1476 }
1477 EXPORT_SYMBOL(sock_create_kern);
1478 
1479 int __sys_socket(int family, int type, int protocol)
1480 {
1481 	int retval;
1482 	struct socket *sock;
1483 	int flags;
1484 
1485 	/* Check the SOCK_* constants for consistency.  */
1486 	BUILD_BUG_ON(SOCK_CLOEXEC != O_CLOEXEC);
1487 	BUILD_BUG_ON((SOCK_MAX | SOCK_TYPE_MASK) != SOCK_TYPE_MASK);
1488 	BUILD_BUG_ON(SOCK_CLOEXEC & SOCK_TYPE_MASK);
1489 	BUILD_BUG_ON(SOCK_NONBLOCK & SOCK_TYPE_MASK);
1490 
1491 	flags = type & ~SOCK_TYPE_MASK;
1492 	if (flags & ~(SOCK_CLOEXEC | SOCK_NONBLOCK))
1493 		return -EINVAL;
1494 	type &= SOCK_TYPE_MASK;
1495 
1496 	if (SOCK_NONBLOCK != O_NONBLOCK && (flags & SOCK_NONBLOCK))
1497 		flags = (flags & ~SOCK_NONBLOCK) | O_NONBLOCK;
1498 
1499 	retval = sock_create(family, type, protocol, &sock);
1500 	if (retval < 0)
1501 		return retval;
1502 
1503 	return sock_map_fd(sock, flags & (O_CLOEXEC | O_NONBLOCK));
1504 }
1505 
1506 SYSCALL_DEFINE3(socket, int, family, int, type, int, protocol)
1507 {
1508 	return __sys_socket(family, type, protocol);
1509 }
1510 
1511 /*
1512  *	Create a pair of connected sockets.
1513  */
1514 
1515 int __sys_socketpair(int family, int type, int protocol, int __user *usockvec)
1516 {
1517 	struct socket *sock1, *sock2;
1518 	int fd1, fd2, err;
1519 	struct file *newfile1, *newfile2;
1520 	int flags;
1521 
1522 	flags = type & ~SOCK_TYPE_MASK;
1523 	if (flags & ~(SOCK_CLOEXEC | SOCK_NONBLOCK))
1524 		return -EINVAL;
1525 	type &= SOCK_TYPE_MASK;
1526 
1527 	if (SOCK_NONBLOCK != O_NONBLOCK && (flags & SOCK_NONBLOCK))
1528 		flags = (flags & ~SOCK_NONBLOCK) | O_NONBLOCK;
1529 
1530 	/*
1531 	 * reserve descriptors and make sure we won't fail
1532 	 * to return them to userland.
1533 	 */
1534 	fd1 = get_unused_fd_flags(flags);
1535 	if (unlikely(fd1 < 0))
1536 		return fd1;
1537 
1538 	fd2 = get_unused_fd_flags(flags);
1539 	if (unlikely(fd2 < 0)) {
1540 		put_unused_fd(fd1);
1541 		return fd2;
1542 	}
1543 
1544 	err = put_user(fd1, &usockvec[0]);
1545 	if (err)
1546 		goto out;
1547 
1548 	err = put_user(fd2, &usockvec[1]);
1549 	if (err)
1550 		goto out;
1551 
1552 	/*
1553 	 * Obtain the first socket and check if the underlying protocol
1554 	 * supports the socketpair call.
1555 	 */
1556 
1557 	err = sock_create(family, type, protocol, &sock1);
1558 	if (unlikely(err < 0))
1559 		goto out;
1560 
1561 	err = sock_create(family, type, protocol, &sock2);
1562 	if (unlikely(err < 0)) {
1563 		sock_release(sock1);
1564 		goto out;
1565 	}
1566 
1567 	err = security_socket_socketpair(sock1, sock2);
1568 	if (unlikely(err)) {
1569 		sock_release(sock2);
1570 		sock_release(sock1);
1571 		goto out;
1572 	}
1573 
1574 	err = sock1->ops->socketpair(sock1, sock2);
1575 	if (unlikely(err < 0)) {
1576 		sock_release(sock2);
1577 		sock_release(sock1);
1578 		goto out;
1579 	}
1580 
1581 	newfile1 = sock_alloc_file(sock1, flags, NULL);
1582 	if (IS_ERR(newfile1)) {
1583 		err = PTR_ERR(newfile1);
1584 		sock_release(sock2);
1585 		goto out;
1586 	}
1587 
1588 	newfile2 = sock_alloc_file(sock2, flags, NULL);
1589 	if (IS_ERR(newfile2)) {
1590 		err = PTR_ERR(newfile2);
1591 		fput(newfile1);
1592 		goto out;
1593 	}
1594 
1595 	audit_fd_pair(fd1, fd2);
1596 
1597 	fd_install(fd1, newfile1);
1598 	fd_install(fd2, newfile2);
1599 	return 0;
1600 
1601 out:
1602 	put_unused_fd(fd2);
1603 	put_unused_fd(fd1);
1604 	return err;
1605 }
1606 
1607 SYSCALL_DEFINE4(socketpair, int, family, int, type, int, protocol,
1608 		int __user *, usockvec)
1609 {
1610 	return __sys_socketpair(family, type, protocol, usockvec);
1611 }
1612 
1613 /*
1614  *	Bind a name to a socket. Nothing much to do here since it's
1615  *	the protocol's responsibility to handle the local address.
1616  *
1617  *	We move the socket address to kernel space before we call
1618  *	the protocol layer (having also checked the address is ok).
1619  */
1620 
1621 int __sys_bind(int fd, struct sockaddr __user *umyaddr, int addrlen)
1622 {
1623 	struct socket *sock;
1624 	struct sockaddr_storage address;
1625 	int err, fput_needed;
1626 
1627 	sock = sockfd_lookup_light(fd, &err, &fput_needed);
1628 	if (sock) {
1629 		err = move_addr_to_kernel(umyaddr, addrlen, &address);
1630 		if (!err) {
1631 			err = security_socket_bind(sock,
1632 						   (struct sockaddr *)&address,
1633 						   addrlen);
1634 			if (!err)
1635 				err = sock->ops->bind(sock,
1636 						      (struct sockaddr *)
1637 						      &address, addrlen);
1638 		}
1639 		fput_light(sock->file, fput_needed);
1640 	}
1641 	return err;
1642 }
1643 
1644 SYSCALL_DEFINE3(bind, int, fd, struct sockaddr __user *, umyaddr, int, addrlen)
1645 {
1646 	return __sys_bind(fd, umyaddr, addrlen);
1647 }
1648 
1649 /*
1650  *	Perform a listen. Basically, we allow the protocol to do anything
1651  *	necessary for a listen, and if that works, we mark the socket as
1652  *	ready for listening.
1653  */
1654 
1655 int __sys_listen(int fd, int backlog)
1656 {
1657 	struct socket *sock;
1658 	int err, fput_needed;
1659 	int somaxconn;
1660 
1661 	sock = sockfd_lookup_light(fd, &err, &fput_needed);
1662 	if (sock) {
1663 		somaxconn = sock_net(sock->sk)->core.sysctl_somaxconn;
1664 		if ((unsigned int)backlog > somaxconn)
1665 			backlog = somaxconn;
1666 
1667 		err = security_socket_listen(sock, backlog);
1668 		if (!err)
1669 			err = sock->ops->listen(sock, backlog);
1670 
1671 		fput_light(sock->file, fput_needed);
1672 	}
1673 	return err;
1674 }
1675 
1676 SYSCALL_DEFINE2(listen, int, fd, int, backlog)
1677 {
1678 	return __sys_listen(fd, backlog);
1679 }
1680 
1681 int __sys_accept4_file(struct file *file, unsigned file_flags,
1682 		       struct sockaddr __user *upeer_sockaddr,
1683 		       int __user *upeer_addrlen, int flags,
1684 		       unsigned long nofile)
1685 {
1686 	struct socket *sock, *newsock;
1687 	struct file *newfile;
1688 	int err, len, newfd;
1689 	struct sockaddr_storage address;
1690 
1691 	if (flags & ~(SOCK_CLOEXEC | SOCK_NONBLOCK))
1692 		return -EINVAL;
1693 
1694 	if (SOCK_NONBLOCK != O_NONBLOCK && (flags & SOCK_NONBLOCK))
1695 		flags = (flags & ~SOCK_NONBLOCK) | O_NONBLOCK;
1696 
1697 	sock = sock_from_file(file);
1698 	if (!sock) {
1699 		err = -ENOTSOCK;
1700 		goto out;
1701 	}
1702 
1703 	err = -ENFILE;
1704 	newsock = sock_alloc();
1705 	if (!newsock)
1706 		goto out;
1707 
1708 	newsock->type = sock->type;
1709 	newsock->ops = sock->ops;
1710 
1711 	/*
1712 	 * We don't need try_module_get here, as the listening socket (sock)
1713 	 * has the protocol module (sock->ops->owner) held.
1714 	 */
1715 	__module_get(newsock->ops->owner);
1716 
1717 	newfd = __get_unused_fd_flags(flags, nofile);
1718 	if (unlikely(newfd < 0)) {
1719 		err = newfd;
1720 		sock_release(newsock);
1721 		goto out;
1722 	}
1723 	newfile = sock_alloc_file(newsock, flags, sock->sk->sk_prot_creator->name);
1724 	if (IS_ERR(newfile)) {
1725 		err = PTR_ERR(newfile);
1726 		put_unused_fd(newfd);
1727 		goto out;
1728 	}
1729 
1730 	err = security_socket_accept(sock, newsock);
1731 	if (err)
1732 		goto out_fd;
1733 
1734 	err = sock->ops->accept(sock, newsock, sock->file->f_flags | file_flags,
1735 					false);
1736 	if (err < 0)
1737 		goto out_fd;
1738 
1739 	if (upeer_sockaddr) {
1740 		len = newsock->ops->getname(newsock,
1741 					(struct sockaddr *)&address, 2);
1742 		if (len < 0) {
1743 			err = -ECONNABORTED;
1744 			goto out_fd;
1745 		}
1746 		err = move_addr_to_user(&address,
1747 					len, upeer_sockaddr, upeer_addrlen);
1748 		if (err < 0)
1749 			goto out_fd;
1750 	}
1751 
1752 	/* File flags are not inherited via accept() unlike another OSes. */
1753 
1754 	fd_install(newfd, newfile);
1755 	err = newfd;
1756 out:
1757 	return err;
1758 out_fd:
1759 	fput(newfile);
1760 	put_unused_fd(newfd);
1761 	goto out;
1762 
1763 }
1764 
1765 /*
1766  *	For accept, we attempt to create a new socket, set up the link
1767  *	with the client, wake up the client, then return the new
1768  *	connected fd. We collect the address of the connector in kernel
1769  *	space and move it to user at the very end. This is unclean because
1770  *	we open the socket then return an error.
1771  *
1772  *	1003.1g adds the ability to recvmsg() to query connection pending
1773  *	status to recvmsg. We need to add that support in a way thats
1774  *	clean when we restructure accept also.
1775  */
1776 
1777 int __sys_accept4(int fd, struct sockaddr __user *upeer_sockaddr,
1778 		  int __user *upeer_addrlen, int flags)
1779 {
1780 	int ret = -EBADF;
1781 	struct fd f;
1782 
1783 	f = fdget(fd);
1784 	if (f.file) {
1785 		ret = __sys_accept4_file(f.file, 0, upeer_sockaddr,
1786 						upeer_addrlen, flags,
1787 						rlimit(RLIMIT_NOFILE));
1788 		fdput(f);
1789 	}
1790 
1791 	return ret;
1792 }
1793 
1794 SYSCALL_DEFINE4(accept4, int, fd, struct sockaddr __user *, upeer_sockaddr,
1795 		int __user *, upeer_addrlen, int, flags)
1796 {
1797 	return __sys_accept4(fd, upeer_sockaddr, upeer_addrlen, flags);
1798 }
1799 
1800 SYSCALL_DEFINE3(accept, int, fd, struct sockaddr __user *, upeer_sockaddr,
1801 		int __user *, upeer_addrlen)
1802 {
1803 	return __sys_accept4(fd, upeer_sockaddr, upeer_addrlen, 0);
1804 }
1805 
1806 /*
1807  *	Attempt to connect to a socket with the server address.  The address
1808  *	is in user space so we verify it is OK and move it to kernel space.
1809  *
1810  *	For 1003.1g we need to add clean support for a bind to AF_UNSPEC to
1811  *	break bindings
1812  *
1813  *	NOTE: 1003.1g draft 6.3 is broken with respect to AX.25/NetROM and
1814  *	other SEQPACKET protocols that take time to connect() as it doesn't
1815  *	include the -EINPROGRESS status for such sockets.
1816  */
1817 
1818 int __sys_connect_file(struct file *file, struct sockaddr_storage *address,
1819 		       int addrlen, int file_flags)
1820 {
1821 	struct socket *sock;
1822 	int err;
1823 
1824 	sock = sock_from_file(file);
1825 	if (!sock) {
1826 		err = -ENOTSOCK;
1827 		goto out;
1828 	}
1829 
1830 	err =
1831 	    security_socket_connect(sock, (struct sockaddr *)address, addrlen);
1832 	if (err)
1833 		goto out;
1834 
1835 	err = sock->ops->connect(sock, (struct sockaddr *)address, addrlen,
1836 				 sock->file->f_flags | file_flags);
1837 out:
1838 	return err;
1839 }
1840 
1841 int __sys_connect(int fd, struct sockaddr __user *uservaddr, int addrlen)
1842 {
1843 	int ret = -EBADF;
1844 	struct fd f;
1845 
1846 	f = fdget(fd);
1847 	if (f.file) {
1848 		struct sockaddr_storage address;
1849 
1850 		ret = move_addr_to_kernel(uservaddr, addrlen, &address);
1851 		if (!ret)
1852 			ret = __sys_connect_file(f.file, &address, addrlen, 0);
1853 		fdput(f);
1854 	}
1855 
1856 	return ret;
1857 }
1858 
1859 SYSCALL_DEFINE3(connect, int, fd, struct sockaddr __user *, uservaddr,
1860 		int, addrlen)
1861 {
1862 	return __sys_connect(fd, uservaddr, addrlen);
1863 }
1864 
1865 /*
1866  *	Get the local address ('name') of a socket object. Move the obtained
1867  *	name to user space.
1868  */
1869 
1870 int __sys_getsockname(int fd, struct sockaddr __user *usockaddr,
1871 		      int __user *usockaddr_len)
1872 {
1873 	struct socket *sock;
1874 	struct sockaddr_storage address;
1875 	int err, fput_needed;
1876 
1877 	sock = sockfd_lookup_light(fd, &err, &fput_needed);
1878 	if (!sock)
1879 		goto out;
1880 
1881 	err = security_socket_getsockname(sock);
1882 	if (err)
1883 		goto out_put;
1884 
1885 	err = sock->ops->getname(sock, (struct sockaddr *)&address, 0);
1886 	if (err < 0)
1887 		goto out_put;
1888         /* "err" is actually length in this case */
1889 	err = move_addr_to_user(&address, err, usockaddr, usockaddr_len);
1890 
1891 out_put:
1892 	fput_light(sock->file, fput_needed);
1893 out:
1894 	return err;
1895 }
1896 
1897 SYSCALL_DEFINE3(getsockname, int, fd, struct sockaddr __user *, usockaddr,
1898 		int __user *, usockaddr_len)
1899 {
1900 	return __sys_getsockname(fd, usockaddr, usockaddr_len);
1901 }
1902 
1903 /*
1904  *	Get the remote address ('name') of a socket object. Move the obtained
1905  *	name to user space.
1906  */
1907 
1908 int __sys_getpeername(int fd, struct sockaddr __user *usockaddr,
1909 		      int __user *usockaddr_len)
1910 {
1911 	struct socket *sock;
1912 	struct sockaddr_storage address;
1913 	int err, fput_needed;
1914 
1915 	sock = sockfd_lookup_light(fd, &err, &fput_needed);
1916 	if (sock != NULL) {
1917 		err = security_socket_getpeername(sock);
1918 		if (err) {
1919 			fput_light(sock->file, fput_needed);
1920 			return err;
1921 		}
1922 
1923 		err = sock->ops->getname(sock, (struct sockaddr *)&address, 1);
1924 		if (err >= 0)
1925 			/* "err" is actually length in this case */
1926 			err = move_addr_to_user(&address, err, usockaddr,
1927 						usockaddr_len);
1928 		fput_light(sock->file, fput_needed);
1929 	}
1930 	return err;
1931 }
1932 
1933 SYSCALL_DEFINE3(getpeername, int, fd, struct sockaddr __user *, usockaddr,
1934 		int __user *, usockaddr_len)
1935 {
1936 	return __sys_getpeername(fd, usockaddr, usockaddr_len);
1937 }
1938 
1939 /*
1940  *	Send a datagram to a given address. We move the address into kernel
1941  *	space and check the user space data area is readable before invoking
1942  *	the protocol.
1943  */
1944 int __sys_sendto(int fd, void __user *buff, size_t len, unsigned int flags,
1945 		 struct sockaddr __user *addr,  int addr_len)
1946 {
1947 	struct socket *sock;
1948 	struct sockaddr_storage address;
1949 	int err;
1950 	struct msghdr msg;
1951 	struct iovec iov;
1952 	int fput_needed;
1953 
1954 	err = import_single_range(WRITE, buff, len, &iov, &msg.msg_iter);
1955 	if (unlikely(err))
1956 		return err;
1957 	sock = sockfd_lookup_light(fd, &err, &fput_needed);
1958 	if (!sock)
1959 		goto out;
1960 
1961 	msg.msg_name = NULL;
1962 	msg.msg_control = NULL;
1963 	msg.msg_controllen = 0;
1964 	msg.msg_namelen = 0;
1965 	if (addr) {
1966 		err = move_addr_to_kernel(addr, addr_len, &address);
1967 		if (err < 0)
1968 			goto out_put;
1969 		msg.msg_name = (struct sockaddr *)&address;
1970 		msg.msg_namelen = addr_len;
1971 	}
1972 	if (sock->file->f_flags & O_NONBLOCK)
1973 		flags |= MSG_DONTWAIT;
1974 	msg.msg_flags = flags;
1975 	err = sock_sendmsg(sock, &msg);
1976 
1977 out_put:
1978 	fput_light(sock->file, fput_needed);
1979 out:
1980 	return err;
1981 }
1982 
1983 SYSCALL_DEFINE6(sendto, int, fd, void __user *, buff, size_t, len,
1984 		unsigned int, flags, struct sockaddr __user *, addr,
1985 		int, addr_len)
1986 {
1987 	return __sys_sendto(fd, buff, len, flags, addr, addr_len);
1988 }
1989 
1990 /*
1991  *	Send a datagram down a socket.
1992  */
1993 
1994 SYSCALL_DEFINE4(send, int, fd, void __user *, buff, size_t, len,
1995 		unsigned int, flags)
1996 {
1997 	return __sys_sendto(fd, buff, len, flags, NULL, 0);
1998 }
1999 
2000 /*
2001  *	Receive a frame from the socket and optionally record the address of the
2002  *	sender. We verify the buffers are writable and if needed move the
2003  *	sender address from kernel to user space.
2004  */
2005 int __sys_recvfrom(int fd, void __user *ubuf, size_t size, unsigned int flags,
2006 		   struct sockaddr __user *addr, int __user *addr_len)
2007 {
2008 	struct socket *sock;
2009 	struct iovec iov;
2010 	struct msghdr msg;
2011 	struct sockaddr_storage address;
2012 	int err, err2;
2013 	int fput_needed;
2014 
2015 	err = import_single_range(READ, ubuf, size, &iov, &msg.msg_iter);
2016 	if (unlikely(err))
2017 		return err;
2018 	sock = sockfd_lookup_light(fd, &err, &fput_needed);
2019 	if (!sock)
2020 		goto out;
2021 
2022 	msg.msg_control = NULL;
2023 	msg.msg_controllen = 0;
2024 	/* Save some cycles and don't copy the address if not needed */
2025 	msg.msg_name = addr ? (struct sockaddr *)&address : NULL;
2026 	/* We assume all kernel code knows the size of sockaddr_storage */
2027 	msg.msg_namelen = 0;
2028 	msg.msg_iocb = NULL;
2029 	msg.msg_flags = 0;
2030 	if (sock->file->f_flags & O_NONBLOCK)
2031 		flags |= MSG_DONTWAIT;
2032 	err = sock_recvmsg(sock, &msg, flags);
2033 
2034 	if (err >= 0 && addr != NULL) {
2035 		err2 = move_addr_to_user(&address,
2036 					 msg.msg_namelen, addr, addr_len);
2037 		if (err2 < 0)
2038 			err = err2;
2039 	}
2040 
2041 	fput_light(sock->file, fput_needed);
2042 out:
2043 	return err;
2044 }
2045 
2046 SYSCALL_DEFINE6(recvfrom, int, fd, void __user *, ubuf, size_t, size,
2047 		unsigned int, flags, struct sockaddr __user *, addr,
2048 		int __user *, addr_len)
2049 {
2050 	return __sys_recvfrom(fd, ubuf, size, flags, addr, addr_len);
2051 }
2052 
2053 /*
2054  *	Receive a datagram from a socket.
2055  */
2056 
2057 SYSCALL_DEFINE4(recv, int, fd, void __user *, ubuf, size_t, size,
2058 		unsigned int, flags)
2059 {
2060 	return __sys_recvfrom(fd, ubuf, size, flags, NULL, NULL);
2061 }
2062 
2063 static bool sock_use_custom_sol_socket(const struct socket *sock)
2064 {
2065 	const struct sock *sk = sock->sk;
2066 
2067 	/* Use sock->ops->setsockopt() for MPTCP */
2068 	return IS_ENABLED(CONFIG_MPTCP) &&
2069 	       sk->sk_protocol == IPPROTO_MPTCP &&
2070 	       sk->sk_type == SOCK_STREAM &&
2071 	       (sk->sk_family == AF_INET || sk->sk_family == AF_INET6);
2072 }
2073 
2074 /*
2075  *	Set a socket option. Because we don't know the option lengths we have
2076  *	to pass the user mode parameter for the protocols to sort out.
2077  */
2078 int __sys_setsockopt(int fd, int level, int optname, char __user *user_optval,
2079 		int optlen)
2080 {
2081 	sockptr_t optval = USER_SOCKPTR(user_optval);
2082 	char *kernel_optval = NULL;
2083 	int err, fput_needed;
2084 	struct socket *sock;
2085 
2086 	if (optlen < 0)
2087 		return -EINVAL;
2088 
2089 	sock = sockfd_lookup_light(fd, &err, &fput_needed);
2090 	if (!sock)
2091 		return err;
2092 
2093 	err = security_socket_setsockopt(sock, level, optname);
2094 	if (err)
2095 		goto out_put;
2096 
2097 	if (!in_compat_syscall())
2098 		err = BPF_CGROUP_RUN_PROG_SETSOCKOPT(sock->sk, &level, &optname,
2099 						     user_optval, &optlen,
2100 						     &kernel_optval);
2101 	if (err < 0)
2102 		goto out_put;
2103 	if (err > 0) {
2104 		err = 0;
2105 		goto out_put;
2106 	}
2107 
2108 	if (kernel_optval)
2109 		optval = KERNEL_SOCKPTR(kernel_optval);
2110 	if (level == SOL_SOCKET && !sock_use_custom_sol_socket(sock))
2111 		err = sock_setsockopt(sock, level, optname, optval, optlen);
2112 	else if (unlikely(!sock->ops->setsockopt))
2113 		err = -EOPNOTSUPP;
2114 	else
2115 		err = sock->ops->setsockopt(sock, level, optname, optval,
2116 					    optlen);
2117 	kfree(kernel_optval);
2118 out_put:
2119 	fput_light(sock->file, fput_needed);
2120 	return err;
2121 }
2122 
2123 SYSCALL_DEFINE5(setsockopt, int, fd, int, level, int, optname,
2124 		char __user *, optval, int, optlen)
2125 {
2126 	return __sys_setsockopt(fd, level, optname, optval, optlen);
2127 }
2128 
2129 /*
2130  *	Get a socket option. Because we don't know the option lengths we have
2131  *	to pass a user mode parameter for the protocols to sort out.
2132  */
2133 int __sys_getsockopt(int fd, int level, int optname, char __user *optval,
2134 		int __user *optlen)
2135 {
2136 	int err, fput_needed;
2137 	struct socket *sock;
2138 	int max_optlen;
2139 
2140 	sock = sockfd_lookup_light(fd, &err, &fput_needed);
2141 	if (!sock)
2142 		return err;
2143 
2144 	err = security_socket_getsockopt(sock, level, optname);
2145 	if (err)
2146 		goto out_put;
2147 
2148 	if (!in_compat_syscall())
2149 		max_optlen = BPF_CGROUP_GETSOCKOPT_MAX_OPTLEN(optlen);
2150 
2151 	if (level == SOL_SOCKET)
2152 		err = sock_getsockopt(sock, level, optname, optval, optlen);
2153 	else if (unlikely(!sock->ops->getsockopt))
2154 		err = -EOPNOTSUPP;
2155 	else
2156 		err = sock->ops->getsockopt(sock, level, optname, optval,
2157 					    optlen);
2158 
2159 	if (!in_compat_syscall())
2160 		err = BPF_CGROUP_RUN_PROG_GETSOCKOPT(sock->sk, level, optname,
2161 						     optval, optlen, max_optlen,
2162 						     err);
2163 out_put:
2164 	fput_light(sock->file, fput_needed);
2165 	return err;
2166 }
2167 
2168 SYSCALL_DEFINE5(getsockopt, int, fd, int, level, int, optname,
2169 		char __user *, optval, int __user *, optlen)
2170 {
2171 	return __sys_getsockopt(fd, level, optname, optval, optlen);
2172 }
2173 
2174 /*
2175  *	Shutdown a socket.
2176  */
2177 
2178 int __sys_shutdown_sock(struct socket *sock, int how)
2179 {
2180 	int err;
2181 
2182 	err = security_socket_shutdown(sock, how);
2183 	if (!err)
2184 		err = sock->ops->shutdown(sock, how);
2185 
2186 	return err;
2187 }
2188 
2189 int __sys_shutdown(int fd, int how)
2190 {
2191 	int err, fput_needed;
2192 	struct socket *sock;
2193 
2194 	sock = sockfd_lookup_light(fd, &err, &fput_needed);
2195 	if (sock != NULL) {
2196 		err = __sys_shutdown_sock(sock, how);
2197 		fput_light(sock->file, fput_needed);
2198 	}
2199 	return err;
2200 }
2201 
2202 SYSCALL_DEFINE2(shutdown, int, fd, int, how)
2203 {
2204 	return __sys_shutdown(fd, how);
2205 }
2206 
2207 /* A couple of helpful macros for getting the address of the 32/64 bit
2208  * fields which are the same type (int / unsigned) on our platforms.
2209  */
2210 #define COMPAT_MSG(msg, member)	((MSG_CMSG_COMPAT & flags) ? &msg##_compat->member : &msg->member)
2211 #define COMPAT_NAMELEN(msg)	COMPAT_MSG(msg, msg_namelen)
2212 #define COMPAT_FLAGS(msg)	COMPAT_MSG(msg, msg_flags)
2213 
2214 struct used_address {
2215 	struct sockaddr_storage name;
2216 	unsigned int name_len;
2217 };
2218 
2219 int __copy_msghdr_from_user(struct msghdr *kmsg,
2220 			    struct user_msghdr __user *umsg,
2221 			    struct sockaddr __user **save_addr,
2222 			    struct iovec __user **uiov, size_t *nsegs)
2223 {
2224 	struct user_msghdr msg;
2225 	ssize_t err;
2226 
2227 	if (copy_from_user(&msg, umsg, sizeof(*umsg)))
2228 		return -EFAULT;
2229 
2230 	kmsg->msg_control_is_user = true;
2231 	kmsg->msg_control_user = msg.msg_control;
2232 	kmsg->msg_controllen = msg.msg_controllen;
2233 	kmsg->msg_flags = msg.msg_flags;
2234 
2235 	kmsg->msg_namelen = msg.msg_namelen;
2236 	if (!msg.msg_name)
2237 		kmsg->msg_namelen = 0;
2238 
2239 	if (kmsg->msg_namelen < 0)
2240 		return -EINVAL;
2241 
2242 	if (kmsg->msg_namelen > sizeof(struct sockaddr_storage))
2243 		kmsg->msg_namelen = sizeof(struct sockaddr_storage);
2244 
2245 	if (save_addr)
2246 		*save_addr = msg.msg_name;
2247 
2248 	if (msg.msg_name && kmsg->msg_namelen) {
2249 		if (!save_addr) {
2250 			err = move_addr_to_kernel(msg.msg_name,
2251 						  kmsg->msg_namelen,
2252 						  kmsg->msg_name);
2253 			if (err < 0)
2254 				return err;
2255 		}
2256 	} else {
2257 		kmsg->msg_name = NULL;
2258 		kmsg->msg_namelen = 0;
2259 	}
2260 
2261 	if (msg.msg_iovlen > UIO_MAXIOV)
2262 		return -EMSGSIZE;
2263 
2264 	kmsg->msg_iocb = NULL;
2265 	*uiov = msg.msg_iov;
2266 	*nsegs = msg.msg_iovlen;
2267 	return 0;
2268 }
2269 
2270 static int copy_msghdr_from_user(struct msghdr *kmsg,
2271 				 struct user_msghdr __user *umsg,
2272 				 struct sockaddr __user **save_addr,
2273 				 struct iovec **iov)
2274 {
2275 	struct user_msghdr msg;
2276 	ssize_t err;
2277 
2278 	err = __copy_msghdr_from_user(kmsg, umsg, save_addr, &msg.msg_iov,
2279 					&msg.msg_iovlen);
2280 	if (err)
2281 		return err;
2282 
2283 	err = import_iovec(save_addr ? READ : WRITE,
2284 			    msg.msg_iov, msg.msg_iovlen,
2285 			    UIO_FASTIOV, iov, &kmsg->msg_iter);
2286 	return err < 0 ? err : 0;
2287 }
2288 
2289 static int ____sys_sendmsg(struct socket *sock, struct msghdr *msg_sys,
2290 			   unsigned int flags, struct used_address *used_address,
2291 			   unsigned int allowed_msghdr_flags)
2292 {
2293 	unsigned char ctl[sizeof(struct cmsghdr) + 20]
2294 				__aligned(sizeof(__kernel_size_t));
2295 	/* 20 is size of ipv6_pktinfo */
2296 	unsigned char *ctl_buf = ctl;
2297 	int ctl_len;
2298 	ssize_t err;
2299 
2300 	err = -ENOBUFS;
2301 
2302 	if (msg_sys->msg_controllen > INT_MAX)
2303 		goto out;
2304 	flags |= (msg_sys->msg_flags & allowed_msghdr_flags);
2305 	ctl_len = msg_sys->msg_controllen;
2306 	if ((MSG_CMSG_COMPAT & flags) && ctl_len) {
2307 		err =
2308 		    cmsghdr_from_user_compat_to_kern(msg_sys, sock->sk, ctl,
2309 						     sizeof(ctl));
2310 		if (err)
2311 			goto out;
2312 		ctl_buf = msg_sys->msg_control;
2313 		ctl_len = msg_sys->msg_controllen;
2314 	} else if (ctl_len) {
2315 		BUILD_BUG_ON(sizeof(struct cmsghdr) !=
2316 			     CMSG_ALIGN(sizeof(struct cmsghdr)));
2317 		if (ctl_len > sizeof(ctl)) {
2318 			ctl_buf = sock_kmalloc(sock->sk, ctl_len, GFP_KERNEL);
2319 			if (ctl_buf == NULL)
2320 				goto out;
2321 		}
2322 		err = -EFAULT;
2323 		if (copy_from_user(ctl_buf, msg_sys->msg_control_user, ctl_len))
2324 			goto out_freectl;
2325 		msg_sys->msg_control = ctl_buf;
2326 		msg_sys->msg_control_is_user = false;
2327 	}
2328 	msg_sys->msg_flags = flags;
2329 
2330 	if (sock->file->f_flags & O_NONBLOCK)
2331 		msg_sys->msg_flags |= MSG_DONTWAIT;
2332 	/*
2333 	 * If this is sendmmsg() and current destination address is same as
2334 	 * previously succeeded address, omit asking LSM's decision.
2335 	 * used_address->name_len is initialized to UINT_MAX so that the first
2336 	 * destination address never matches.
2337 	 */
2338 	if (used_address && msg_sys->msg_name &&
2339 	    used_address->name_len == msg_sys->msg_namelen &&
2340 	    !memcmp(&used_address->name, msg_sys->msg_name,
2341 		    used_address->name_len)) {
2342 		err = sock_sendmsg_nosec(sock, msg_sys);
2343 		goto out_freectl;
2344 	}
2345 	err = sock_sendmsg(sock, msg_sys);
2346 	/*
2347 	 * If this is sendmmsg() and sending to current destination address was
2348 	 * successful, remember it.
2349 	 */
2350 	if (used_address && err >= 0) {
2351 		used_address->name_len = msg_sys->msg_namelen;
2352 		if (msg_sys->msg_name)
2353 			memcpy(&used_address->name, msg_sys->msg_name,
2354 			       used_address->name_len);
2355 	}
2356 
2357 out_freectl:
2358 	if (ctl_buf != ctl)
2359 		sock_kfree_s(sock->sk, ctl_buf, ctl_len);
2360 out:
2361 	return err;
2362 }
2363 
2364 int sendmsg_copy_msghdr(struct msghdr *msg,
2365 			struct user_msghdr __user *umsg, unsigned flags,
2366 			struct iovec **iov)
2367 {
2368 	int err;
2369 
2370 	if (flags & MSG_CMSG_COMPAT) {
2371 		struct compat_msghdr __user *msg_compat;
2372 
2373 		msg_compat = (struct compat_msghdr __user *) umsg;
2374 		err = get_compat_msghdr(msg, msg_compat, NULL, iov);
2375 	} else {
2376 		err = copy_msghdr_from_user(msg, umsg, NULL, iov);
2377 	}
2378 	if (err < 0)
2379 		return err;
2380 
2381 	return 0;
2382 }
2383 
2384 static int ___sys_sendmsg(struct socket *sock, struct user_msghdr __user *msg,
2385 			 struct msghdr *msg_sys, unsigned int flags,
2386 			 struct used_address *used_address,
2387 			 unsigned int allowed_msghdr_flags)
2388 {
2389 	struct sockaddr_storage address;
2390 	struct iovec iovstack[UIO_FASTIOV], *iov = iovstack;
2391 	ssize_t err;
2392 
2393 	msg_sys->msg_name = &address;
2394 
2395 	err = sendmsg_copy_msghdr(msg_sys, msg, flags, &iov);
2396 	if (err < 0)
2397 		return err;
2398 
2399 	err = ____sys_sendmsg(sock, msg_sys, flags, used_address,
2400 				allowed_msghdr_flags);
2401 	kfree(iov);
2402 	return err;
2403 }
2404 
2405 /*
2406  *	BSD sendmsg interface
2407  */
2408 long __sys_sendmsg_sock(struct socket *sock, struct msghdr *msg,
2409 			unsigned int flags)
2410 {
2411 	/* disallow ancillary data requests from this path */
2412 	if (msg->msg_control || msg->msg_controllen)
2413 		return -EINVAL;
2414 
2415 	return ____sys_sendmsg(sock, msg, flags, NULL, 0);
2416 }
2417 
2418 long __sys_sendmsg(int fd, struct user_msghdr __user *msg, unsigned int flags,
2419 		   bool forbid_cmsg_compat)
2420 {
2421 	int fput_needed, err;
2422 	struct msghdr msg_sys;
2423 	struct socket *sock;
2424 
2425 	if (forbid_cmsg_compat && (flags & MSG_CMSG_COMPAT))
2426 		return -EINVAL;
2427 
2428 	sock = sockfd_lookup_light(fd, &err, &fput_needed);
2429 	if (!sock)
2430 		goto out;
2431 
2432 	err = ___sys_sendmsg(sock, msg, &msg_sys, flags, NULL, 0);
2433 
2434 	fput_light(sock->file, fput_needed);
2435 out:
2436 	return err;
2437 }
2438 
2439 SYSCALL_DEFINE3(sendmsg, int, fd, struct user_msghdr __user *, msg, unsigned int, flags)
2440 {
2441 	return __sys_sendmsg(fd, msg, flags, true);
2442 }
2443 
2444 /*
2445  *	Linux sendmmsg interface
2446  */
2447 
2448 int __sys_sendmmsg(int fd, struct mmsghdr __user *mmsg, unsigned int vlen,
2449 		   unsigned int flags, bool forbid_cmsg_compat)
2450 {
2451 	int fput_needed, err, datagrams;
2452 	struct socket *sock;
2453 	struct mmsghdr __user *entry;
2454 	struct compat_mmsghdr __user *compat_entry;
2455 	struct msghdr msg_sys;
2456 	struct used_address used_address;
2457 	unsigned int oflags = flags;
2458 
2459 	if (forbid_cmsg_compat && (flags & MSG_CMSG_COMPAT))
2460 		return -EINVAL;
2461 
2462 	if (vlen > UIO_MAXIOV)
2463 		vlen = UIO_MAXIOV;
2464 
2465 	datagrams = 0;
2466 
2467 	sock = sockfd_lookup_light(fd, &err, &fput_needed);
2468 	if (!sock)
2469 		return err;
2470 
2471 	used_address.name_len = UINT_MAX;
2472 	entry = mmsg;
2473 	compat_entry = (struct compat_mmsghdr __user *)mmsg;
2474 	err = 0;
2475 	flags |= MSG_BATCH;
2476 
2477 	while (datagrams < vlen) {
2478 		if (datagrams == vlen - 1)
2479 			flags = oflags;
2480 
2481 		if (MSG_CMSG_COMPAT & flags) {
2482 			err = ___sys_sendmsg(sock, (struct user_msghdr __user *)compat_entry,
2483 					     &msg_sys, flags, &used_address, MSG_EOR);
2484 			if (err < 0)
2485 				break;
2486 			err = __put_user(err, &compat_entry->msg_len);
2487 			++compat_entry;
2488 		} else {
2489 			err = ___sys_sendmsg(sock,
2490 					     (struct user_msghdr __user *)entry,
2491 					     &msg_sys, flags, &used_address, MSG_EOR);
2492 			if (err < 0)
2493 				break;
2494 			err = put_user(err, &entry->msg_len);
2495 			++entry;
2496 		}
2497 
2498 		if (err)
2499 			break;
2500 		++datagrams;
2501 		if (msg_data_left(&msg_sys))
2502 			break;
2503 		cond_resched();
2504 	}
2505 
2506 	fput_light(sock->file, fput_needed);
2507 
2508 	/* We only return an error if no datagrams were able to be sent */
2509 	if (datagrams != 0)
2510 		return datagrams;
2511 
2512 	return err;
2513 }
2514 
2515 SYSCALL_DEFINE4(sendmmsg, int, fd, struct mmsghdr __user *, mmsg,
2516 		unsigned int, vlen, unsigned int, flags)
2517 {
2518 	return __sys_sendmmsg(fd, mmsg, vlen, flags, true);
2519 }
2520 
2521 int recvmsg_copy_msghdr(struct msghdr *msg,
2522 			struct user_msghdr __user *umsg, unsigned flags,
2523 			struct sockaddr __user **uaddr,
2524 			struct iovec **iov)
2525 {
2526 	ssize_t err;
2527 
2528 	if (MSG_CMSG_COMPAT & flags) {
2529 		struct compat_msghdr __user *msg_compat;
2530 
2531 		msg_compat = (struct compat_msghdr __user *) umsg;
2532 		err = get_compat_msghdr(msg, msg_compat, uaddr, iov);
2533 	} else {
2534 		err = copy_msghdr_from_user(msg, umsg, uaddr, iov);
2535 	}
2536 	if (err < 0)
2537 		return err;
2538 
2539 	return 0;
2540 }
2541 
2542 static int ____sys_recvmsg(struct socket *sock, struct msghdr *msg_sys,
2543 			   struct user_msghdr __user *msg,
2544 			   struct sockaddr __user *uaddr,
2545 			   unsigned int flags, int nosec)
2546 {
2547 	struct compat_msghdr __user *msg_compat =
2548 					(struct compat_msghdr __user *) msg;
2549 	int __user *uaddr_len = COMPAT_NAMELEN(msg);
2550 	struct sockaddr_storage addr;
2551 	unsigned long cmsg_ptr;
2552 	int len;
2553 	ssize_t err;
2554 
2555 	msg_sys->msg_name = &addr;
2556 	cmsg_ptr = (unsigned long)msg_sys->msg_control;
2557 	msg_sys->msg_flags = flags & (MSG_CMSG_CLOEXEC|MSG_CMSG_COMPAT);
2558 
2559 	/* We assume all kernel code knows the size of sockaddr_storage */
2560 	msg_sys->msg_namelen = 0;
2561 
2562 	if (sock->file->f_flags & O_NONBLOCK)
2563 		flags |= MSG_DONTWAIT;
2564 
2565 	if (unlikely(nosec))
2566 		err = sock_recvmsg_nosec(sock, msg_sys, flags);
2567 	else
2568 		err = sock_recvmsg(sock, msg_sys, flags);
2569 
2570 	if (err < 0)
2571 		goto out;
2572 	len = err;
2573 
2574 	if (uaddr != NULL) {
2575 		err = move_addr_to_user(&addr,
2576 					msg_sys->msg_namelen, uaddr,
2577 					uaddr_len);
2578 		if (err < 0)
2579 			goto out;
2580 	}
2581 	err = __put_user((msg_sys->msg_flags & ~MSG_CMSG_COMPAT),
2582 			 COMPAT_FLAGS(msg));
2583 	if (err)
2584 		goto out;
2585 	if (MSG_CMSG_COMPAT & flags)
2586 		err = __put_user((unsigned long)msg_sys->msg_control - cmsg_ptr,
2587 				 &msg_compat->msg_controllen);
2588 	else
2589 		err = __put_user((unsigned long)msg_sys->msg_control - cmsg_ptr,
2590 				 &msg->msg_controllen);
2591 	if (err)
2592 		goto out;
2593 	err = len;
2594 out:
2595 	return err;
2596 }
2597 
2598 static int ___sys_recvmsg(struct socket *sock, struct user_msghdr __user *msg,
2599 			 struct msghdr *msg_sys, unsigned int flags, int nosec)
2600 {
2601 	struct iovec iovstack[UIO_FASTIOV], *iov = iovstack;
2602 	/* user mode address pointers */
2603 	struct sockaddr __user *uaddr;
2604 	ssize_t err;
2605 
2606 	err = recvmsg_copy_msghdr(msg_sys, msg, flags, &uaddr, &iov);
2607 	if (err < 0)
2608 		return err;
2609 
2610 	err = ____sys_recvmsg(sock, msg_sys, msg, uaddr, flags, nosec);
2611 	kfree(iov);
2612 	return err;
2613 }
2614 
2615 /*
2616  *	BSD recvmsg interface
2617  */
2618 
2619 long __sys_recvmsg_sock(struct socket *sock, struct msghdr *msg,
2620 			struct user_msghdr __user *umsg,
2621 			struct sockaddr __user *uaddr, unsigned int flags)
2622 {
2623 	if (msg->msg_control || msg->msg_controllen) {
2624 		/* disallow ancillary data reqs unless cmsg is plain data */
2625 		if (!(sock->ops->flags & PROTO_CMSG_DATA_ONLY))
2626 			return -EINVAL;
2627 	}
2628 
2629 	return ____sys_recvmsg(sock, msg, umsg, uaddr, flags, 0);
2630 }
2631 
2632 long __sys_recvmsg(int fd, struct user_msghdr __user *msg, unsigned int flags,
2633 		   bool forbid_cmsg_compat)
2634 {
2635 	int fput_needed, err;
2636 	struct msghdr msg_sys;
2637 	struct socket *sock;
2638 
2639 	if (forbid_cmsg_compat && (flags & MSG_CMSG_COMPAT))
2640 		return -EINVAL;
2641 
2642 	sock = sockfd_lookup_light(fd, &err, &fput_needed);
2643 	if (!sock)
2644 		goto out;
2645 
2646 	err = ___sys_recvmsg(sock, msg, &msg_sys, flags, 0);
2647 
2648 	fput_light(sock->file, fput_needed);
2649 out:
2650 	return err;
2651 }
2652 
2653 SYSCALL_DEFINE3(recvmsg, int, fd, struct user_msghdr __user *, msg,
2654 		unsigned int, flags)
2655 {
2656 	return __sys_recvmsg(fd, msg, flags, true);
2657 }
2658 
2659 /*
2660  *     Linux recvmmsg interface
2661  */
2662 
2663 static int do_recvmmsg(int fd, struct mmsghdr __user *mmsg,
2664 			  unsigned int vlen, unsigned int flags,
2665 			  struct timespec64 *timeout)
2666 {
2667 	int fput_needed, err, datagrams;
2668 	struct socket *sock;
2669 	struct mmsghdr __user *entry;
2670 	struct compat_mmsghdr __user *compat_entry;
2671 	struct msghdr msg_sys;
2672 	struct timespec64 end_time;
2673 	struct timespec64 timeout64;
2674 
2675 	if (timeout &&
2676 	    poll_select_set_timeout(&end_time, timeout->tv_sec,
2677 				    timeout->tv_nsec))
2678 		return -EINVAL;
2679 
2680 	datagrams = 0;
2681 
2682 	sock = sockfd_lookup_light(fd, &err, &fput_needed);
2683 	if (!sock)
2684 		return err;
2685 
2686 	if (likely(!(flags & MSG_ERRQUEUE))) {
2687 		err = sock_error(sock->sk);
2688 		if (err) {
2689 			datagrams = err;
2690 			goto out_put;
2691 		}
2692 	}
2693 
2694 	entry = mmsg;
2695 	compat_entry = (struct compat_mmsghdr __user *)mmsg;
2696 
2697 	while (datagrams < vlen) {
2698 		/*
2699 		 * No need to ask LSM for more than the first datagram.
2700 		 */
2701 		if (MSG_CMSG_COMPAT & flags) {
2702 			err = ___sys_recvmsg(sock, (struct user_msghdr __user *)compat_entry,
2703 					     &msg_sys, flags & ~MSG_WAITFORONE,
2704 					     datagrams);
2705 			if (err < 0)
2706 				break;
2707 			err = __put_user(err, &compat_entry->msg_len);
2708 			++compat_entry;
2709 		} else {
2710 			err = ___sys_recvmsg(sock,
2711 					     (struct user_msghdr __user *)entry,
2712 					     &msg_sys, flags & ~MSG_WAITFORONE,
2713 					     datagrams);
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 
2724 		/* MSG_WAITFORONE turns on MSG_DONTWAIT after one packet */
2725 		if (flags & MSG_WAITFORONE)
2726 			flags |= MSG_DONTWAIT;
2727 
2728 		if (timeout) {
2729 			ktime_get_ts64(&timeout64);
2730 			*timeout = timespec64_sub(end_time, timeout64);
2731 			if (timeout->tv_sec < 0) {
2732 				timeout->tv_sec = timeout->tv_nsec = 0;
2733 				break;
2734 			}
2735 
2736 			/* Timeout, return less than vlen datagrams */
2737 			if (timeout->tv_nsec == 0 && timeout->tv_sec == 0)
2738 				break;
2739 		}
2740 
2741 		/* Out of band data, return right away */
2742 		if (msg_sys.msg_flags & MSG_OOB)
2743 			break;
2744 		cond_resched();
2745 	}
2746 
2747 	if (err == 0)
2748 		goto out_put;
2749 
2750 	if (datagrams == 0) {
2751 		datagrams = err;
2752 		goto out_put;
2753 	}
2754 
2755 	/*
2756 	 * We may return less entries than requested (vlen) if the
2757 	 * sock is non block and there aren't enough datagrams...
2758 	 */
2759 	if (err != -EAGAIN) {
2760 		/*
2761 		 * ... or  if recvmsg returns an error after we
2762 		 * received some datagrams, where we record the
2763 		 * error to return on the next call or if the
2764 		 * app asks about it using getsockopt(SO_ERROR).
2765 		 */
2766 		sock->sk->sk_err = -err;
2767 	}
2768 out_put:
2769 	fput_light(sock->file, fput_needed);
2770 
2771 	return datagrams;
2772 }
2773 
2774 int __sys_recvmmsg(int fd, struct mmsghdr __user *mmsg,
2775 		   unsigned int vlen, unsigned int flags,
2776 		   struct __kernel_timespec __user *timeout,
2777 		   struct old_timespec32 __user *timeout32)
2778 {
2779 	int datagrams;
2780 	struct timespec64 timeout_sys;
2781 
2782 	if (timeout && get_timespec64(&timeout_sys, timeout))
2783 		return -EFAULT;
2784 
2785 	if (timeout32 && get_old_timespec32(&timeout_sys, timeout32))
2786 		return -EFAULT;
2787 
2788 	if (!timeout && !timeout32)
2789 		return do_recvmmsg(fd, mmsg, vlen, flags, NULL);
2790 
2791 	datagrams = do_recvmmsg(fd, mmsg, vlen, flags, &timeout_sys);
2792 
2793 	if (datagrams <= 0)
2794 		return datagrams;
2795 
2796 	if (timeout && put_timespec64(&timeout_sys, timeout))
2797 		datagrams = -EFAULT;
2798 
2799 	if (timeout32 && put_old_timespec32(&timeout_sys, timeout32))
2800 		datagrams = -EFAULT;
2801 
2802 	return datagrams;
2803 }
2804 
2805 SYSCALL_DEFINE5(recvmmsg, int, fd, struct mmsghdr __user *, mmsg,
2806 		unsigned int, vlen, unsigned int, flags,
2807 		struct __kernel_timespec __user *, timeout)
2808 {
2809 	if (flags & MSG_CMSG_COMPAT)
2810 		return -EINVAL;
2811 
2812 	return __sys_recvmmsg(fd, mmsg, vlen, flags, timeout, NULL);
2813 }
2814 
2815 #ifdef CONFIG_COMPAT_32BIT_TIME
2816 SYSCALL_DEFINE5(recvmmsg_time32, int, fd, struct mmsghdr __user *, mmsg,
2817 		unsigned int, vlen, unsigned int, flags,
2818 		struct old_timespec32 __user *, timeout)
2819 {
2820 	if (flags & MSG_CMSG_COMPAT)
2821 		return -EINVAL;
2822 
2823 	return __sys_recvmmsg(fd, mmsg, vlen, flags, NULL, timeout);
2824 }
2825 #endif
2826 
2827 #ifdef __ARCH_WANT_SYS_SOCKETCALL
2828 /* Argument list sizes for sys_socketcall */
2829 #define AL(x) ((x) * sizeof(unsigned long))
2830 static const unsigned char nargs[21] = {
2831 	AL(0), AL(3), AL(3), AL(3), AL(2), AL(3),
2832 	AL(3), AL(3), AL(4), AL(4), AL(4), AL(6),
2833 	AL(6), AL(2), AL(5), AL(5), AL(3), AL(3),
2834 	AL(4), AL(5), AL(4)
2835 };
2836 
2837 #undef AL
2838 
2839 /*
2840  *	System call vectors.
2841  *
2842  *	Argument checking cleaned up. Saved 20% in size.
2843  *  This function doesn't need to set the kernel lock because
2844  *  it is set by the callees.
2845  */
2846 
2847 SYSCALL_DEFINE2(socketcall, int, call, unsigned long __user *, args)
2848 {
2849 	unsigned long a[AUDITSC_ARGS];
2850 	unsigned long a0, a1;
2851 	int err;
2852 	unsigned int len;
2853 
2854 	if (call < 1 || call > SYS_SENDMMSG)
2855 		return -EINVAL;
2856 	call = array_index_nospec(call, SYS_SENDMMSG + 1);
2857 
2858 	len = nargs[call];
2859 	if (len > sizeof(a))
2860 		return -EINVAL;
2861 
2862 	/* copy_from_user should be SMP safe. */
2863 	if (copy_from_user(a, args, len))
2864 		return -EFAULT;
2865 
2866 	err = audit_socketcall(nargs[call] / sizeof(unsigned long), a);
2867 	if (err)
2868 		return err;
2869 
2870 	a0 = a[0];
2871 	a1 = a[1];
2872 
2873 	switch (call) {
2874 	case SYS_SOCKET:
2875 		err = __sys_socket(a0, a1, a[2]);
2876 		break;
2877 	case SYS_BIND:
2878 		err = __sys_bind(a0, (struct sockaddr __user *)a1, a[2]);
2879 		break;
2880 	case SYS_CONNECT:
2881 		err = __sys_connect(a0, (struct sockaddr __user *)a1, a[2]);
2882 		break;
2883 	case SYS_LISTEN:
2884 		err = __sys_listen(a0, a1);
2885 		break;
2886 	case SYS_ACCEPT:
2887 		err = __sys_accept4(a0, (struct sockaddr __user *)a1,
2888 				    (int __user *)a[2], 0);
2889 		break;
2890 	case SYS_GETSOCKNAME:
2891 		err =
2892 		    __sys_getsockname(a0, (struct sockaddr __user *)a1,
2893 				      (int __user *)a[2]);
2894 		break;
2895 	case SYS_GETPEERNAME:
2896 		err =
2897 		    __sys_getpeername(a0, (struct sockaddr __user *)a1,
2898 				      (int __user *)a[2]);
2899 		break;
2900 	case SYS_SOCKETPAIR:
2901 		err = __sys_socketpair(a0, a1, a[2], (int __user *)a[3]);
2902 		break;
2903 	case SYS_SEND:
2904 		err = __sys_sendto(a0, (void __user *)a1, a[2], a[3],
2905 				   NULL, 0);
2906 		break;
2907 	case SYS_SENDTO:
2908 		err = __sys_sendto(a0, (void __user *)a1, a[2], a[3],
2909 				   (struct sockaddr __user *)a[4], a[5]);
2910 		break;
2911 	case SYS_RECV:
2912 		err = __sys_recvfrom(a0, (void __user *)a1, a[2], a[3],
2913 				     NULL, NULL);
2914 		break;
2915 	case SYS_RECVFROM:
2916 		err = __sys_recvfrom(a0, (void __user *)a1, a[2], a[3],
2917 				     (struct sockaddr __user *)a[4],
2918 				     (int __user *)a[5]);
2919 		break;
2920 	case SYS_SHUTDOWN:
2921 		err = __sys_shutdown(a0, a1);
2922 		break;
2923 	case SYS_SETSOCKOPT:
2924 		err = __sys_setsockopt(a0, a1, a[2], (char __user *)a[3],
2925 				       a[4]);
2926 		break;
2927 	case SYS_GETSOCKOPT:
2928 		err =
2929 		    __sys_getsockopt(a0, a1, a[2], (char __user *)a[3],
2930 				     (int __user *)a[4]);
2931 		break;
2932 	case SYS_SENDMSG:
2933 		err = __sys_sendmsg(a0, (struct user_msghdr __user *)a1,
2934 				    a[2], true);
2935 		break;
2936 	case SYS_SENDMMSG:
2937 		err = __sys_sendmmsg(a0, (struct mmsghdr __user *)a1, a[2],
2938 				     a[3], true);
2939 		break;
2940 	case SYS_RECVMSG:
2941 		err = __sys_recvmsg(a0, (struct user_msghdr __user *)a1,
2942 				    a[2], true);
2943 		break;
2944 	case SYS_RECVMMSG:
2945 		if (IS_ENABLED(CONFIG_64BIT))
2946 			err = __sys_recvmmsg(a0, (struct mmsghdr __user *)a1,
2947 					     a[2], a[3],
2948 					     (struct __kernel_timespec __user *)a[4],
2949 					     NULL);
2950 		else
2951 			err = __sys_recvmmsg(a0, (struct mmsghdr __user *)a1,
2952 					     a[2], a[3], NULL,
2953 					     (struct old_timespec32 __user *)a[4]);
2954 		break;
2955 	case SYS_ACCEPT4:
2956 		err = __sys_accept4(a0, (struct sockaddr __user *)a1,
2957 				    (int __user *)a[2], a[3]);
2958 		break;
2959 	default:
2960 		err = -EINVAL;
2961 		break;
2962 	}
2963 	return err;
2964 }
2965 
2966 #endif				/* __ARCH_WANT_SYS_SOCKETCALL */
2967 
2968 /**
2969  *	sock_register - add a socket protocol handler
2970  *	@ops: description of protocol
2971  *
2972  *	This function is called by a protocol handler that wants to
2973  *	advertise its address family, and have it linked into the
2974  *	socket interface. The value ops->family corresponds to the
2975  *	socket system call protocol family.
2976  */
2977 int sock_register(const struct net_proto_family *ops)
2978 {
2979 	int err;
2980 
2981 	if (ops->family >= NPROTO) {
2982 		pr_crit("protocol %d >= NPROTO(%d)\n", ops->family, NPROTO);
2983 		return -ENOBUFS;
2984 	}
2985 
2986 	spin_lock(&net_family_lock);
2987 	if (rcu_dereference_protected(net_families[ops->family],
2988 				      lockdep_is_held(&net_family_lock)))
2989 		err = -EEXIST;
2990 	else {
2991 		rcu_assign_pointer(net_families[ops->family], ops);
2992 		err = 0;
2993 	}
2994 	spin_unlock(&net_family_lock);
2995 
2996 	pr_info("NET: Registered protocol family %d\n", ops->family);
2997 	return err;
2998 }
2999 EXPORT_SYMBOL(sock_register);
3000 
3001 /**
3002  *	sock_unregister - remove a protocol handler
3003  *	@family: protocol family to remove
3004  *
3005  *	This function is called by a protocol handler that wants to
3006  *	remove its address family, and have it unlinked from the
3007  *	new socket creation.
3008  *
3009  *	If protocol handler is a module, then it can use module reference
3010  *	counts to protect against new references. If protocol handler is not
3011  *	a module then it needs to provide its own protection in
3012  *	the ops->create routine.
3013  */
3014 void sock_unregister(int family)
3015 {
3016 	BUG_ON(family < 0 || family >= NPROTO);
3017 
3018 	spin_lock(&net_family_lock);
3019 	RCU_INIT_POINTER(net_families[family], NULL);
3020 	spin_unlock(&net_family_lock);
3021 
3022 	synchronize_rcu();
3023 
3024 	pr_info("NET: Unregistered protocol family %d\n", family);
3025 }
3026 EXPORT_SYMBOL(sock_unregister);
3027 
3028 bool sock_is_registered(int family)
3029 {
3030 	return family < NPROTO && rcu_access_pointer(net_families[family]);
3031 }
3032 
3033 static int __init sock_init(void)
3034 {
3035 	int err;
3036 	/*
3037 	 *      Initialize the network sysctl infrastructure.
3038 	 */
3039 	err = net_sysctl_init();
3040 	if (err)
3041 		goto out;
3042 
3043 	/*
3044 	 *      Initialize skbuff SLAB cache
3045 	 */
3046 	skb_init();
3047 
3048 	/*
3049 	 *      Initialize the protocols module.
3050 	 */
3051 
3052 	init_inodecache();
3053 
3054 	err = register_filesystem(&sock_fs_type);
3055 	if (err)
3056 		goto out;
3057 	sock_mnt = kern_mount(&sock_fs_type);
3058 	if (IS_ERR(sock_mnt)) {
3059 		err = PTR_ERR(sock_mnt);
3060 		goto out_mount;
3061 	}
3062 
3063 	/* The real protocol initialization is performed in later initcalls.
3064 	 */
3065 
3066 #ifdef CONFIG_NETFILTER
3067 	err = netfilter_init();
3068 	if (err)
3069 		goto out;
3070 #endif
3071 
3072 	ptp_classifier_init();
3073 
3074 out:
3075 	return err;
3076 
3077 out_mount:
3078 	unregister_filesystem(&sock_fs_type);
3079 	goto out;
3080 }
3081 
3082 core_initcall(sock_init);	/* early initcall */
3083 
3084 #ifdef CONFIG_PROC_FS
3085 void socket_seq_show(struct seq_file *seq)
3086 {
3087 	seq_printf(seq, "sockets: used %d\n",
3088 		   sock_inuse_get(seq->private));
3089 }
3090 #endif				/* CONFIG_PROC_FS */
3091 
3092 #ifdef CONFIG_COMPAT
3093 static int compat_dev_ifconf(struct net *net, struct compat_ifconf __user *uifc32)
3094 {
3095 	struct compat_ifconf ifc32;
3096 	struct ifconf ifc;
3097 	int err;
3098 
3099 	if (copy_from_user(&ifc32, uifc32, sizeof(struct compat_ifconf)))
3100 		return -EFAULT;
3101 
3102 	ifc.ifc_len = ifc32.ifc_len;
3103 	ifc.ifc_req = compat_ptr(ifc32.ifcbuf);
3104 
3105 	rtnl_lock();
3106 	err = dev_ifconf(net, &ifc, sizeof(struct compat_ifreq));
3107 	rtnl_unlock();
3108 	if (err)
3109 		return err;
3110 
3111 	ifc32.ifc_len = ifc.ifc_len;
3112 	if (copy_to_user(uifc32, &ifc32, sizeof(struct compat_ifconf)))
3113 		return -EFAULT;
3114 
3115 	return 0;
3116 }
3117 
3118 static int ethtool_ioctl(struct net *net, struct compat_ifreq __user *ifr32)
3119 {
3120 	struct compat_ethtool_rxnfc __user *compat_rxnfc;
3121 	bool convert_in = false, convert_out = false;
3122 	size_t buf_size = 0;
3123 	struct ethtool_rxnfc __user *rxnfc = NULL;
3124 	struct ifreq ifr;
3125 	u32 rule_cnt = 0, actual_rule_cnt;
3126 	u32 ethcmd;
3127 	u32 data;
3128 	int ret;
3129 
3130 	if (get_user(data, &ifr32->ifr_ifru.ifru_data))
3131 		return -EFAULT;
3132 
3133 	compat_rxnfc = compat_ptr(data);
3134 
3135 	if (get_user(ethcmd, &compat_rxnfc->cmd))
3136 		return -EFAULT;
3137 
3138 	/* Most ethtool structures are defined without padding.
3139 	 * Unfortunately struct ethtool_rxnfc is an exception.
3140 	 */
3141 	switch (ethcmd) {
3142 	default:
3143 		break;
3144 	case ETHTOOL_GRXCLSRLALL:
3145 		/* Buffer size is variable */
3146 		if (get_user(rule_cnt, &compat_rxnfc->rule_cnt))
3147 			return -EFAULT;
3148 		if (rule_cnt > KMALLOC_MAX_SIZE / sizeof(u32))
3149 			return -ENOMEM;
3150 		buf_size += rule_cnt * sizeof(u32);
3151 		fallthrough;
3152 	case ETHTOOL_GRXRINGS:
3153 	case ETHTOOL_GRXCLSRLCNT:
3154 	case ETHTOOL_GRXCLSRULE:
3155 	case ETHTOOL_SRXCLSRLINS:
3156 		convert_out = true;
3157 		fallthrough;
3158 	case ETHTOOL_SRXCLSRLDEL:
3159 		buf_size += sizeof(struct ethtool_rxnfc);
3160 		convert_in = true;
3161 		rxnfc = compat_alloc_user_space(buf_size);
3162 		break;
3163 	}
3164 
3165 	if (copy_from_user(&ifr.ifr_name, &ifr32->ifr_name, IFNAMSIZ))
3166 		return -EFAULT;
3167 
3168 	ifr.ifr_data = convert_in ? rxnfc : (void __user *)compat_rxnfc;
3169 
3170 	if (convert_in) {
3171 		/* We expect there to be holes between fs.m_ext and
3172 		 * fs.ring_cookie and at the end of fs, but nowhere else.
3173 		 */
3174 		BUILD_BUG_ON(offsetof(struct compat_ethtool_rxnfc, fs.m_ext) +
3175 			     sizeof(compat_rxnfc->fs.m_ext) !=
3176 			     offsetof(struct ethtool_rxnfc, fs.m_ext) +
3177 			     sizeof(rxnfc->fs.m_ext));
3178 		BUILD_BUG_ON(
3179 			offsetof(struct compat_ethtool_rxnfc, fs.location) -
3180 			offsetof(struct compat_ethtool_rxnfc, fs.ring_cookie) !=
3181 			offsetof(struct ethtool_rxnfc, fs.location) -
3182 			offsetof(struct ethtool_rxnfc, fs.ring_cookie));
3183 
3184 		if (copy_in_user(rxnfc, compat_rxnfc,
3185 				 (void __user *)(&rxnfc->fs.m_ext + 1) -
3186 				 (void __user *)rxnfc) ||
3187 		    copy_in_user(&rxnfc->fs.ring_cookie,
3188 				 &compat_rxnfc->fs.ring_cookie,
3189 				 (void __user *)(&rxnfc->fs.location + 1) -
3190 				 (void __user *)&rxnfc->fs.ring_cookie))
3191 			return -EFAULT;
3192 		if (ethcmd == ETHTOOL_GRXCLSRLALL) {
3193 			if (put_user(rule_cnt, &rxnfc->rule_cnt))
3194 				return -EFAULT;
3195 		} else if (copy_in_user(&rxnfc->rule_cnt,
3196 					&compat_rxnfc->rule_cnt,
3197 					sizeof(rxnfc->rule_cnt)))
3198 			return -EFAULT;
3199 	}
3200 
3201 	ret = dev_ioctl(net, SIOCETHTOOL, &ifr, NULL);
3202 	if (ret)
3203 		return ret;
3204 
3205 	if (convert_out) {
3206 		if (copy_in_user(compat_rxnfc, rxnfc,
3207 				 (const void __user *)(&rxnfc->fs.m_ext + 1) -
3208 				 (const void __user *)rxnfc) ||
3209 		    copy_in_user(&compat_rxnfc->fs.ring_cookie,
3210 				 &rxnfc->fs.ring_cookie,
3211 				 (const void __user *)(&rxnfc->fs.location + 1) -
3212 				 (const void __user *)&rxnfc->fs.ring_cookie) ||
3213 		    copy_in_user(&compat_rxnfc->rule_cnt, &rxnfc->rule_cnt,
3214 				 sizeof(rxnfc->rule_cnt)))
3215 			return -EFAULT;
3216 
3217 		if (ethcmd == ETHTOOL_GRXCLSRLALL) {
3218 			/* As an optimisation, we only copy the actual
3219 			 * number of rules that the underlying
3220 			 * function returned.  Since Mallory might
3221 			 * change the rule count in user memory, we
3222 			 * check that it is less than the rule count
3223 			 * originally given (as the user buffer size),
3224 			 * which has been range-checked.
3225 			 */
3226 			if (get_user(actual_rule_cnt, &rxnfc->rule_cnt))
3227 				return -EFAULT;
3228 			if (actual_rule_cnt < rule_cnt)
3229 				rule_cnt = actual_rule_cnt;
3230 			if (copy_in_user(&compat_rxnfc->rule_locs[0],
3231 					 &rxnfc->rule_locs[0],
3232 					 rule_cnt * sizeof(u32)))
3233 				return -EFAULT;
3234 		}
3235 	}
3236 
3237 	return 0;
3238 }
3239 
3240 static int compat_siocwandev(struct net *net, struct compat_ifreq __user *uifr32)
3241 {
3242 	compat_uptr_t uptr32;
3243 	struct ifreq ifr;
3244 	void __user *saved;
3245 	int err;
3246 
3247 	if (copy_from_user(&ifr, uifr32, sizeof(struct compat_ifreq)))
3248 		return -EFAULT;
3249 
3250 	if (get_user(uptr32, &uifr32->ifr_settings.ifs_ifsu))
3251 		return -EFAULT;
3252 
3253 	saved = ifr.ifr_settings.ifs_ifsu.raw_hdlc;
3254 	ifr.ifr_settings.ifs_ifsu.raw_hdlc = compat_ptr(uptr32);
3255 
3256 	err = dev_ioctl(net, SIOCWANDEV, &ifr, NULL);
3257 	if (!err) {
3258 		ifr.ifr_settings.ifs_ifsu.raw_hdlc = saved;
3259 		if (copy_to_user(uifr32, &ifr, sizeof(struct compat_ifreq)))
3260 			err = -EFAULT;
3261 	}
3262 	return err;
3263 }
3264 
3265 /* Handle ioctls that use ifreq::ifr_data and just need struct ifreq converted */
3266 static int compat_ifr_data_ioctl(struct net *net, unsigned int cmd,
3267 				 struct compat_ifreq __user *u_ifreq32)
3268 {
3269 	struct ifreq ifreq;
3270 	u32 data32;
3271 
3272 	if (copy_from_user(ifreq.ifr_name, u_ifreq32->ifr_name, IFNAMSIZ))
3273 		return -EFAULT;
3274 	if (get_user(data32, &u_ifreq32->ifr_data))
3275 		return -EFAULT;
3276 	ifreq.ifr_data = compat_ptr(data32);
3277 
3278 	return dev_ioctl(net, cmd, &ifreq, NULL);
3279 }
3280 
3281 static int compat_ifreq_ioctl(struct net *net, struct socket *sock,
3282 			      unsigned int cmd,
3283 			      struct compat_ifreq __user *uifr32)
3284 {
3285 	struct ifreq __user *uifr;
3286 	int err;
3287 
3288 	/* Handle the fact that while struct ifreq has the same *layout* on
3289 	 * 32/64 for everything but ifreq::ifru_ifmap and ifreq::ifru_data,
3290 	 * which are handled elsewhere, it still has different *size* due to
3291 	 * ifreq::ifru_ifmap (which is 16 bytes on 32 bit, 24 bytes on 64-bit,
3292 	 * resulting in struct ifreq being 32 and 40 bytes respectively).
3293 	 * As a result, if the struct happens to be at the end of a page and
3294 	 * the next page isn't readable/writable, we get a fault. To prevent
3295 	 * that, copy back and forth to the full size.
3296 	 */
3297 
3298 	uifr = compat_alloc_user_space(sizeof(*uifr));
3299 	if (copy_in_user(uifr, uifr32, sizeof(*uifr32)))
3300 		return -EFAULT;
3301 
3302 	err = sock_do_ioctl(net, sock, cmd, (unsigned long)uifr);
3303 
3304 	if (!err) {
3305 		switch (cmd) {
3306 		case SIOCGIFFLAGS:
3307 		case SIOCGIFMETRIC:
3308 		case SIOCGIFMTU:
3309 		case SIOCGIFMEM:
3310 		case SIOCGIFHWADDR:
3311 		case SIOCGIFINDEX:
3312 		case SIOCGIFADDR:
3313 		case SIOCGIFBRDADDR:
3314 		case SIOCGIFDSTADDR:
3315 		case SIOCGIFNETMASK:
3316 		case SIOCGIFPFLAGS:
3317 		case SIOCGIFTXQLEN:
3318 		case SIOCGMIIPHY:
3319 		case SIOCGMIIREG:
3320 		case SIOCGIFNAME:
3321 			if (copy_in_user(uifr32, uifr, sizeof(*uifr32)))
3322 				err = -EFAULT;
3323 			break;
3324 		}
3325 	}
3326 	return err;
3327 }
3328 
3329 static int compat_sioc_ifmap(struct net *net, unsigned int cmd,
3330 			struct compat_ifreq __user *uifr32)
3331 {
3332 	struct ifreq ifr;
3333 	struct compat_ifmap __user *uifmap32;
3334 	int err;
3335 
3336 	uifmap32 = &uifr32->ifr_ifru.ifru_map;
3337 	err = copy_from_user(&ifr, uifr32, sizeof(ifr.ifr_name));
3338 	err |= get_user(ifr.ifr_map.mem_start, &uifmap32->mem_start);
3339 	err |= get_user(ifr.ifr_map.mem_end, &uifmap32->mem_end);
3340 	err |= get_user(ifr.ifr_map.base_addr, &uifmap32->base_addr);
3341 	err |= get_user(ifr.ifr_map.irq, &uifmap32->irq);
3342 	err |= get_user(ifr.ifr_map.dma, &uifmap32->dma);
3343 	err |= get_user(ifr.ifr_map.port, &uifmap32->port);
3344 	if (err)
3345 		return -EFAULT;
3346 
3347 	err = dev_ioctl(net, cmd, &ifr, NULL);
3348 
3349 	if (cmd == SIOCGIFMAP && !err) {
3350 		err = copy_to_user(uifr32, &ifr, sizeof(ifr.ifr_name));
3351 		err |= put_user(ifr.ifr_map.mem_start, &uifmap32->mem_start);
3352 		err |= put_user(ifr.ifr_map.mem_end, &uifmap32->mem_end);
3353 		err |= put_user(ifr.ifr_map.base_addr, &uifmap32->base_addr);
3354 		err |= put_user(ifr.ifr_map.irq, &uifmap32->irq);
3355 		err |= put_user(ifr.ifr_map.dma, &uifmap32->dma);
3356 		err |= put_user(ifr.ifr_map.port, &uifmap32->port);
3357 		if (err)
3358 			err = -EFAULT;
3359 	}
3360 	return err;
3361 }
3362 
3363 /* Since old style bridge ioctl's endup using SIOCDEVPRIVATE
3364  * for some operations; this forces use of the newer bridge-utils that
3365  * use compatible ioctls
3366  */
3367 static int old_bridge_ioctl(compat_ulong_t __user *argp)
3368 {
3369 	compat_ulong_t tmp;
3370 
3371 	if (get_user(tmp, argp))
3372 		return -EFAULT;
3373 	if (tmp == BRCTL_GET_VERSION)
3374 		return BRCTL_VERSION + 1;
3375 	return -EINVAL;
3376 }
3377 
3378 static int compat_sock_ioctl_trans(struct file *file, struct socket *sock,
3379 			 unsigned int cmd, unsigned long arg)
3380 {
3381 	void __user *argp = compat_ptr(arg);
3382 	struct sock *sk = sock->sk;
3383 	struct net *net = sock_net(sk);
3384 
3385 	if (cmd >= SIOCDEVPRIVATE && cmd <= (SIOCDEVPRIVATE + 15))
3386 		return compat_ifr_data_ioctl(net, cmd, argp);
3387 
3388 	switch (cmd) {
3389 	case SIOCSIFBR:
3390 	case SIOCGIFBR:
3391 		return old_bridge_ioctl(argp);
3392 	case SIOCGIFCONF:
3393 		return compat_dev_ifconf(net, argp);
3394 	case SIOCETHTOOL:
3395 		return ethtool_ioctl(net, argp);
3396 	case SIOCWANDEV:
3397 		return compat_siocwandev(net, argp);
3398 	case SIOCGIFMAP:
3399 	case SIOCSIFMAP:
3400 		return compat_sioc_ifmap(net, cmd, argp);
3401 	case SIOCGSTAMP_OLD:
3402 	case SIOCGSTAMPNS_OLD:
3403 		if (!sock->ops->gettstamp)
3404 			return -ENOIOCTLCMD;
3405 		return sock->ops->gettstamp(sock, argp, cmd == SIOCGSTAMP_OLD,
3406 					    !COMPAT_USE_64BIT_TIME);
3407 
3408 	case SIOCBONDSLAVEINFOQUERY:
3409 	case SIOCBONDINFOQUERY:
3410 	case SIOCSHWTSTAMP:
3411 	case SIOCGHWTSTAMP:
3412 		return compat_ifr_data_ioctl(net, cmd, argp);
3413 
3414 	case FIOSETOWN:
3415 	case SIOCSPGRP:
3416 	case FIOGETOWN:
3417 	case SIOCGPGRP:
3418 	case SIOCBRADDBR:
3419 	case SIOCBRDELBR:
3420 	case SIOCGIFVLAN:
3421 	case SIOCSIFVLAN:
3422 	case SIOCGSKNS:
3423 	case SIOCGSTAMP_NEW:
3424 	case SIOCGSTAMPNS_NEW:
3425 		return sock_ioctl(file, cmd, arg);
3426 
3427 	case SIOCGIFFLAGS:
3428 	case SIOCSIFFLAGS:
3429 	case SIOCGIFMETRIC:
3430 	case SIOCSIFMETRIC:
3431 	case SIOCGIFMTU:
3432 	case SIOCSIFMTU:
3433 	case SIOCGIFMEM:
3434 	case SIOCSIFMEM:
3435 	case SIOCGIFHWADDR:
3436 	case SIOCSIFHWADDR:
3437 	case SIOCADDMULTI:
3438 	case SIOCDELMULTI:
3439 	case SIOCGIFINDEX:
3440 	case SIOCGIFADDR:
3441 	case SIOCSIFADDR:
3442 	case SIOCSIFHWBROADCAST:
3443 	case SIOCDIFADDR:
3444 	case SIOCGIFBRDADDR:
3445 	case SIOCSIFBRDADDR:
3446 	case SIOCGIFDSTADDR:
3447 	case SIOCSIFDSTADDR:
3448 	case SIOCGIFNETMASK:
3449 	case SIOCSIFNETMASK:
3450 	case SIOCSIFPFLAGS:
3451 	case SIOCGIFPFLAGS:
3452 	case SIOCGIFTXQLEN:
3453 	case SIOCSIFTXQLEN:
3454 	case SIOCBRADDIF:
3455 	case SIOCBRDELIF:
3456 	case SIOCGIFNAME:
3457 	case SIOCSIFNAME:
3458 	case SIOCGMIIPHY:
3459 	case SIOCGMIIREG:
3460 	case SIOCSMIIREG:
3461 	case SIOCBONDENSLAVE:
3462 	case SIOCBONDRELEASE:
3463 	case SIOCBONDSETHWADDR:
3464 	case SIOCBONDCHANGEACTIVE:
3465 		return compat_ifreq_ioctl(net, sock, cmd, argp);
3466 
3467 	case SIOCSARP:
3468 	case SIOCGARP:
3469 	case SIOCDARP:
3470 	case SIOCOUTQ:
3471 	case SIOCOUTQNSD:
3472 	case SIOCATMARK:
3473 		return sock_do_ioctl(net, sock, cmd, arg);
3474 	}
3475 
3476 	return -ENOIOCTLCMD;
3477 }
3478 
3479 static long compat_sock_ioctl(struct file *file, unsigned int cmd,
3480 			      unsigned long arg)
3481 {
3482 	struct socket *sock = file->private_data;
3483 	int ret = -ENOIOCTLCMD;
3484 	struct sock *sk;
3485 	struct net *net;
3486 
3487 	sk = sock->sk;
3488 	net = sock_net(sk);
3489 
3490 	if (sock->ops->compat_ioctl)
3491 		ret = sock->ops->compat_ioctl(sock, cmd, arg);
3492 
3493 	if (ret == -ENOIOCTLCMD &&
3494 	    (cmd >= SIOCIWFIRST && cmd <= SIOCIWLAST))
3495 		ret = compat_wext_handle_ioctl(net, cmd, arg);
3496 
3497 	if (ret == -ENOIOCTLCMD)
3498 		ret = compat_sock_ioctl_trans(file, sock, cmd, arg);
3499 
3500 	return ret;
3501 }
3502 #endif
3503 
3504 /**
3505  *	kernel_bind - bind an address to a socket (kernel space)
3506  *	@sock: socket
3507  *	@addr: address
3508  *	@addrlen: length of address
3509  *
3510  *	Returns 0 or an error.
3511  */
3512 
3513 int kernel_bind(struct socket *sock, struct sockaddr *addr, int addrlen)
3514 {
3515 	return sock->ops->bind(sock, addr, addrlen);
3516 }
3517 EXPORT_SYMBOL(kernel_bind);
3518 
3519 /**
3520  *	kernel_listen - move socket to listening state (kernel space)
3521  *	@sock: socket
3522  *	@backlog: pending connections queue size
3523  *
3524  *	Returns 0 or an error.
3525  */
3526 
3527 int kernel_listen(struct socket *sock, int backlog)
3528 {
3529 	return sock->ops->listen(sock, backlog);
3530 }
3531 EXPORT_SYMBOL(kernel_listen);
3532 
3533 /**
3534  *	kernel_accept - accept a connection (kernel space)
3535  *	@sock: listening socket
3536  *	@newsock: new connected socket
3537  *	@flags: flags
3538  *
3539  *	@flags must be SOCK_CLOEXEC, SOCK_NONBLOCK or 0.
3540  *	If it fails, @newsock is guaranteed to be %NULL.
3541  *	Returns 0 or an error.
3542  */
3543 
3544 int kernel_accept(struct socket *sock, struct socket **newsock, int flags)
3545 {
3546 	struct sock *sk = sock->sk;
3547 	int err;
3548 
3549 	err = sock_create_lite(sk->sk_family, sk->sk_type, sk->sk_protocol,
3550 			       newsock);
3551 	if (err < 0)
3552 		goto done;
3553 
3554 	err = sock->ops->accept(sock, *newsock, flags, true);
3555 	if (err < 0) {
3556 		sock_release(*newsock);
3557 		*newsock = NULL;
3558 		goto done;
3559 	}
3560 
3561 	(*newsock)->ops = sock->ops;
3562 	__module_get((*newsock)->ops->owner);
3563 
3564 done:
3565 	return err;
3566 }
3567 EXPORT_SYMBOL(kernel_accept);
3568 
3569 /**
3570  *	kernel_connect - connect a socket (kernel space)
3571  *	@sock: socket
3572  *	@addr: address
3573  *	@addrlen: address length
3574  *	@flags: flags (O_NONBLOCK, ...)
3575  *
3576  *	For datagram sockets, @addr is the addres to which datagrams are sent
3577  *	by default, and the only address from which datagrams are received.
3578  *	For stream sockets, attempts to connect to @addr.
3579  *	Returns 0 or an error code.
3580  */
3581 
3582 int kernel_connect(struct socket *sock, struct sockaddr *addr, int addrlen,
3583 		   int flags)
3584 {
3585 	return sock->ops->connect(sock, addr, addrlen, flags);
3586 }
3587 EXPORT_SYMBOL(kernel_connect);
3588 
3589 /**
3590  *	kernel_getsockname - get the address which the socket is bound (kernel space)
3591  *	@sock: socket
3592  *	@addr: address holder
3593  *
3594  * 	Fills the @addr pointer with the address which the socket is bound.
3595  *	Returns 0 or an error code.
3596  */
3597 
3598 int kernel_getsockname(struct socket *sock, struct sockaddr *addr)
3599 {
3600 	return sock->ops->getname(sock, addr, 0);
3601 }
3602 EXPORT_SYMBOL(kernel_getsockname);
3603 
3604 /**
3605  *	kernel_getpeername - get the address which the socket is connected (kernel space)
3606  *	@sock: socket
3607  *	@addr: address holder
3608  *
3609  * 	Fills the @addr pointer with the address which the socket is connected.
3610  *	Returns 0 or an error code.
3611  */
3612 
3613 int kernel_getpeername(struct socket *sock, struct sockaddr *addr)
3614 {
3615 	return sock->ops->getname(sock, addr, 1);
3616 }
3617 EXPORT_SYMBOL(kernel_getpeername);
3618 
3619 /**
3620  *	kernel_sendpage - send a &page through a socket (kernel space)
3621  *	@sock: socket
3622  *	@page: page
3623  *	@offset: page offset
3624  *	@size: total size in bytes
3625  *	@flags: flags (MSG_DONTWAIT, ...)
3626  *
3627  *	Returns the total amount sent in bytes or an error.
3628  */
3629 
3630 int kernel_sendpage(struct socket *sock, struct page *page, int offset,
3631 		    size_t size, int flags)
3632 {
3633 	if (sock->ops->sendpage) {
3634 		/* Warn in case the improper page to zero-copy send */
3635 		WARN_ONCE(!sendpage_ok(page), "improper page for zero-copy send");
3636 		return sock->ops->sendpage(sock, page, offset, size, flags);
3637 	}
3638 	return sock_no_sendpage(sock, page, offset, size, flags);
3639 }
3640 EXPORT_SYMBOL(kernel_sendpage);
3641 
3642 /**
3643  *	kernel_sendpage_locked - send a &page through the locked sock (kernel space)
3644  *	@sk: sock
3645  *	@page: page
3646  *	@offset: page offset
3647  *	@size: total size in bytes
3648  *	@flags: flags (MSG_DONTWAIT, ...)
3649  *
3650  *	Returns the total amount sent in bytes or an error.
3651  *	Caller must hold @sk.
3652  */
3653 
3654 int kernel_sendpage_locked(struct sock *sk, struct page *page, int offset,
3655 			   size_t size, int flags)
3656 {
3657 	struct socket *sock = sk->sk_socket;
3658 
3659 	if (sock->ops->sendpage_locked)
3660 		return sock->ops->sendpage_locked(sk, page, offset, size,
3661 						  flags);
3662 
3663 	return sock_no_sendpage_locked(sk, page, offset, size, flags);
3664 }
3665 EXPORT_SYMBOL(kernel_sendpage_locked);
3666 
3667 /**
3668  *	kernel_sock_shutdown - shut down part of a full-duplex connection (kernel space)
3669  *	@sock: socket
3670  *	@how: connection part
3671  *
3672  *	Returns 0 or an error.
3673  */
3674 
3675 int kernel_sock_shutdown(struct socket *sock, enum sock_shutdown_cmd how)
3676 {
3677 	return sock->ops->shutdown(sock, how);
3678 }
3679 EXPORT_SYMBOL(kernel_sock_shutdown);
3680 
3681 /**
3682  *	kernel_sock_ip_overhead - returns the IP overhead imposed by a socket
3683  *	@sk: socket
3684  *
3685  *	This routine returns the IP overhead imposed by a socket i.e.
3686  *	the length of the underlying IP header, depending on whether
3687  *	this is an IPv4 or IPv6 socket and the length from IP options turned
3688  *	on at the socket. Assumes that the caller has a lock on the socket.
3689  */
3690 
3691 u32 kernel_sock_ip_overhead(struct sock *sk)
3692 {
3693 	struct inet_sock *inet;
3694 	struct ip_options_rcu *opt;
3695 	u32 overhead = 0;
3696 #if IS_ENABLED(CONFIG_IPV6)
3697 	struct ipv6_pinfo *np;
3698 	struct ipv6_txoptions *optv6 = NULL;
3699 #endif /* IS_ENABLED(CONFIG_IPV6) */
3700 
3701 	if (!sk)
3702 		return overhead;
3703 
3704 	switch (sk->sk_family) {
3705 	case AF_INET:
3706 		inet = inet_sk(sk);
3707 		overhead += sizeof(struct iphdr);
3708 		opt = rcu_dereference_protected(inet->inet_opt,
3709 						sock_owned_by_user(sk));
3710 		if (opt)
3711 			overhead += opt->opt.optlen;
3712 		return overhead;
3713 #if IS_ENABLED(CONFIG_IPV6)
3714 	case AF_INET6:
3715 		np = inet6_sk(sk);
3716 		overhead += sizeof(struct ipv6hdr);
3717 		if (np)
3718 			optv6 = rcu_dereference_protected(np->opt,
3719 							  sock_owned_by_user(sk));
3720 		if (optv6)
3721 			overhead += (optv6->opt_flen + optv6->opt_nflen);
3722 		return overhead;
3723 #endif /* IS_ENABLED(CONFIG_IPV6) */
3724 	default: /* Returns 0 overhead if the socket is not ipv4 or ipv6 */
3725 		return overhead;
3726 	}
3727 }
3728 EXPORT_SYMBOL(kernel_sock_ip_overhead);
3729