개념 설명 전체 · v6.18.37 / net/socket.c

    1 // SPDX-License-Identifier: GPL-2.0-or-later
    2 /*
    3  * NET		An implementation of the SOCKET network access protocol.
    4  *
    5  * Version:	@(#)socket.c	1.1.93	18/02/95
    6  *
    7  * Authors:	Orest Zborowski, <obz@Kodak.COM>
    8  *		Ross Biro
    9  *		Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
   10  *
   11  * Fixes:
   12  *		Anonymous	:	NOTSOCK/BADF cleanup. Error fix in
   13  *					shutdown()
   14  *		Alan Cox	:	verify_area() fixes
   15  *		Alan Cox	:	Removed DDI
   16  *		Jonathan Kamens	:	SOCK_DGRAM reconnect bug
   17  *		Alan Cox	:	Moved a load of checks to the very
   18  *					top level.
   19  *		Alan Cox	:	Move address structures to/from user
   20  *					mode above the protocol layers.
   21  *		Rob Janssen	:	Allow 0 length sends.
   22  *		Alan Cox	:	Asynchronous I/O support (cribbed from the
   23  *					tty drivers).
   24  *		Niibe Yutaka	:	Asynchronous I/O for writes (4.4BSD style)
   25  *		Jeff Uphoff	:	Made max number of sockets command-line
   26  *					configurable.
   27  *		Matti Aarnio	:	Made the number of sockets dynamic,
   28  *					to be allocated when needed, and mr.
   29  *					Uphoff's max is used as max to be
   30  *					allowed to allocate.
   31  *		Linus		:	Argh. removed all the socket allocation
   32  *					altogether: it's in the inode now.
   33  *		Alan Cox	:	Made sock_alloc()/sock_release() public
   34  *					for NetROM and future kernel nfsd type
   35  *					stuff.
   36  *		Alan Cox	:	sendmsg/recvmsg basics.
   37  *		Tom Dyas	:	Export net symbols.
   38  *		Marcin Dalecki	:	Fixed problems with CONFIG_NET="n".
   39  *		Alan Cox	:	Added thread locking to sys_* calls
   40  *					for sockets. May have errors at the
   41  *					moment.
   42  *		Kevin Buhr	:	Fixed the dumb errors in the above.
   43  *		Andi Kleen	:	Some small cleanups, optimizations,
   44  *					and fixed a copy_from_user() bug.
   45  *		Tigran Aivazian	:	sys_send(args) calls sys_sendto(args, NULL, 0)
   46  *		Tigran Aivazian	:	Made listen(2) backlog sanity checks
   47  *					protocol-independent
   48  *
   49  *	This module is effectively the top level interface to the BSD socket
   50  *	paradigm.
   51  *
   52  *	Based upon Swansea University Computer Society NET3.039
   53  */
   54 
   55 #include <linux/bpf-cgroup.h>
   56 #include <linux/ethtool.h>
   57 #include <linux/mm.h>
   58 #include <linux/socket.h>
   59 #include <linux/file.h>
   60 #include <linux/splice.h>
   61 #include <linux/net.h>
   62 #include <linux/interrupt.h>
   63 #include <linux/thread_info.h>
   64 #include <linux/rcupdate.h>
   65 #include <linux/netdevice.h>
   66 #include <linux/proc_fs.h>
   67 #include <linux/seq_file.h>
   68 #include <linux/mutex.h>
   69 #include <linux/if_bridge.h>
   70 #include <linux/if_vlan.h>
   71 #include <linux/ptp_classify.h>
   72 #include <linux/init.h>
   73 #include <linux/poll.h>
   74 #include <linux/cache.h>
   75 #include <linux/module.h>
   76 #include <linux/highmem.h>
   77 #include <linux/mount.h>
   78 #include <linux/pseudo_fs.h>
   79 #include <linux/security.h>
   80 #include <linux/syscalls.h>
   81 #include <linux/compat.h>
   82 #include <linux/kmod.h>
   83 #include <linux/audit.h>
   84 #include <linux/wireless.h>
   85 #include <linux/nsproxy.h>
   86 #include <linux/magic.h>
   87 #include <linux/slab.h>
   88 #include <linux/xattr.h>
   89 #include <linux/nospec.h>
   90 #include <linux/indirect_call_wrapper.h>
   91 #include <linux/io_uring/net.h>
   92 
   93 #include <linux/uaccess.h>
   94 #include <asm/unistd.h>
   95 
   96 #include <net/compat.h>
   97 #include <net/wext.h>
   98 #include <net/cls_cgroup.h>
   99 
  100 #include <net/sock.h>
  101 #include <linux/netfilter.h>
  102 
  103 #include <linux/if_tun.h>
  104 #include <linux/ipv6_route.h>
  105 #include <linux/route.h>
  106 #include <linux/termios.h>
  107 #include <linux/sockios.h>
  108 #include <net/busy_poll.h>
  109 #include <linux/errqueue.h>
  110 #include <linux/ptp_clock_kernel.h>
  111 #include <trace/events/sock.h>
  112 
  113 #include "core/dev.h"
  114 
  115 #ifdef CONFIG_NET_RX_BUSY_POLL
  116 unsigned int sysctl_net_busy_read __read_mostly;
  117 unsigned int sysctl_net_busy_poll __read_mostly;
  118 #endif
  119 
  120 static ssize_t sock_read_iter(struct kiocb *iocb, struct iov_iter *to);
  121 static ssize_t sock_write_iter(struct kiocb *iocb, struct iov_iter *from);
  122 static int sock_mmap(struct file *file, struct vm_area_struct *vma);
  123 
  124 static int sock_close(struct inode *inode, struct file *file);
  125 static __poll_t sock_poll(struct file *file,
  126 			      struct poll_table_struct *wait);
  127 static long sock_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
  128 #ifdef CONFIG_COMPAT
  129 static long compat_sock_ioctl(struct file *file,
  130 			      unsigned int cmd, unsigned long arg);
  131 #endif
  132 static int sock_fasync(int fd, struct file *filp, int on);
  133 static ssize_t sock_splice_read(struct file *file, loff_t *ppos,
  134 				struct pipe_inode_info *pipe, size_t len,
  135 				unsigned int flags);
  136 static void sock_splice_eof(struct file *file);
  137 
  138 #ifdef CONFIG_PROC_FS
  139 static void sock_show_fdinfo(struct seq_file *m, struct file *f)
  140 {
  141 	struct socket *sock = f->private_data;
  142 	const struct proto_ops *ops = READ_ONCE(sock->ops);
  143 
  144 	if (ops->show_fdinfo)
  145 		ops->show_fdinfo(m, sock);
  146 }
  147 #else
  148 #define sock_show_fdinfo NULL
  149 #endif
  150 
  151 /*
  152  *	Socket files have a set of 'special' operations as well as the generic file ones. These don't appear
  153  *	in the operation structures but are done directly via the socketcall() multiplexor.
  154  */
  155 
  156 static const struct file_operations socket_file_ops = {
  157 	.owner =	THIS_MODULE,
  158 	.read_iter =	sock_read_iter,
  159 	.write_iter =	sock_write_iter,
  160 	.poll =		sock_poll,
  161 	.unlocked_ioctl = sock_ioctl,
  162 #ifdef CONFIG_COMPAT
  163 	.compat_ioctl = compat_sock_ioctl,
  164 #endif
  165 	.uring_cmd =    io_uring_cmd_sock,
  166 	.mmap =		sock_mmap,
  167 	.release =	sock_close,
  168 	.fasync =	sock_fasync,
  169 	.splice_write = splice_to_socket,
  170 	.splice_read =	sock_splice_read,
  171 	.splice_eof =	sock_splice_eof,
  172 	.show_fdinfo =	sock_show_fdinfo,
  173 };
  174 
  175 static const char * const pf_family_names[] = {
  176 	[PF_UNSPEC]	= "PF_UNSPEC",
  177 	[PF_UNIX]	= "PF_UNIX/PF_LOCAL",
  178 	[PF_INET]	= "PF_INET",
  179 	[PF_AX25]	= "PF_AX25",
  180 	[PF_IPX]	= "PF_IPX",
  181 	[PF_APPLETALK]	= "PF_APPLETALK",
  182 	[PF_NETROM]	= "PF_NETROM",
  183 	[PF_BRIDGE]	= "PF_BRIDGE",
  184 	[PF_ATMPVC]	= "PF_ATMPVC",
  185 	[PF_X25]	= "PF_X25",
  186 	[PF_INET6]	= "PF_INET6",
  187 	[PF_ROSE]	= "PF_ROSE",
  188 	[PF_DECnet]	= "PF_DECnet",
  189 	[PF_NETBEUI]	= "PF_NETBEUI",
  190 	[PF_SECURITY]	= "PF_SECURITY",
  191 	[PF_KEY]	= "PF_KEY",
  192 	[PF_NETLINK]	= "PF_NETLINK/PF_ROUTE",
  193 	[PF_PACKET]	= "PF_PACKET",
  194 	[PF_ASH]	= "PF_ASH",
  195 	[PF_ECONET]	= "PF_ECONET",
  196 	[PF_ATMSVC]	= "PF_ATMSVC",
  197 	[PF_RDS]	= "PF_RDS",
  198 	[PF_SNA]	= "PF_SNA",
  199 	[PF_IRDA]	= "PF_IRDA",
  200 	[PF_PPPOX]	= "PF_PPPOX",
  201 	[PF_WANPIPE]	= "PF_WANPIPE",
  202 	[PF_LLC]	= "PF_LLC",
  203 	[PF_IB]		= "PF_IB",
  204 	[PF_MPLS]	= "PF_MPLS",
  205 	[PF_CAN]	= "PF_CAN",
  206 	[PF_TIPC]	= "PF_TIPC",
  207 	[PF_BLUETOOTH]	= "PF_BLUETOOTH",
  208 	[PF_IUCV]	= "PF_IUCV",
  209 	[PF_RXRPC]	= "PF_RXRPC",
  210 	[PF_ISDN]	= "PF_ISDN",
  211 	[PF_PHONET]	= "PF_PHONET",
  212 	[PF_IEEE802154]	= "PF_IEEE802154",
  213 	[PF_CAIF]	= "PF_CAIF",
  214 	[PF_ALG]	= "PF_ALG",
  215 	[PF_NFC]	= "PF_NFC",
  216 	[PF_VSOCK]	= "PF_VSOCK",
  217 	[PF_KCM]	= "PF_KCM",
  218 	[PF_QIPCRTR]	= "PF_QIPCRTR",
  219 	[PF_SMC]	= "PF_SMC",
  220 	[PF_XDP]	= "PF_XDP",
  221 	[PF_MCTP]	= "PF_MCTP",
  222 };
  223 
  224 /*
  225  *	The protocol list. Each protocol is registered in here.
  226  */
  227 
  228 static DEFINE_SPINLOCK(net_family_lock);
  229 static const struct net_proto_family __rcu *net_families[NPROTO] __read_mostly;
  230 
  231 /*
  232  * Support routines.
  233  * Move socket addresses back and forth across the kernel/user
  234  * divide and look after the messy bits.
  235  */
  236 
  237 /**
  238  *	move_addr_to_kernel	-	copy a socket address into kernel space
  239  *	@uaddr: Address in user space
  240  *	@kaddr: Address in kernel space
  241  *	@ulen: Length in user space
  242  *
  243  *	The address is copied into kernel space. If the provided address is
  244  *	too long an error code of -EINVAL is returned. If the copy gives
  245  *	invalid addresses -EFAULT is returned. On a success 0 is returned.
  246  */
  247 
  248 int move_addr_to_kernel(void __user *uaddr, int ulen, struct sockaddr_storage *kaddr)
  249 {
  250 	if (ulen < 0 || ulen > sizeof(struct sockaddr_storage))
  251 		return -EINVAL;
  252 	if (ulen == 0)
  253 		return 0;
  254 	if (copy_from_user(kaddr, uaddr, ulen))
  255 		return -EFAULT;
  256 	return audit_sockaddr(ulen, kaddr);
  257 }
  258 
  259 /**
  260  *	move_addr_to_user	-	copy an address to user space
  261  *	@kaddr: kernel space address
  262  *	@klen: length of address in kernel
  263  *	@uaddr: user space address
  264  *	@ulen: pointer to user length field
  265  *
  266  *	The value pointed to by ulen on entry is the buffer length available.
  267  *	This is overwritten with the buffer space used. -EINVAL is returned
  268  *	if an overlong buffer is specified or a negative buffer size. -EFAULT
  269  *	is returned if either the buffer or the length field are not
  270  *	accessible.
  271  *	After copying the data up to the limit the user specifies, the true
  272  *	length of the data is written over the length limit the user
  273  *	specified. Zero is returned for a success.
  274  */
  275 
  276 static int move_addr_to_user(struct sockaddr_storage *kaddr, int klen,
  277 			     void __user *uaddr, int __user *ulen)
  278 {
  279 	int len;
  280 
  281 	BUG_ON(klen > sizeof(struct sockaddr_storage));
  282 
  283 	if (can_do_masked_user_access())
  284 		ulen = masked_user_access_begin(ulen);
  285 	else if (!user_access_begin(ulen, 4))
  286 		return -EFAULT;
  287 
  288 	unsafe_get_user(len, ulen, efault_end);
  289 
  290 	if (len > klen)
  291 		len = klen;
  292 	/*
  293 	 *      "fromlen shall refer to the value before truncation.."
  294 	 *                      1003.1g
  295 	 */
  296 	if (len >= 0)
  297 		unsafe_put_user(klen, ulen, efault_end);
  298 
  299 	user_access_end();
  300 
  301 	if (len) {
  302 		if (len < 0)
  303 			return -EINVAL;
  304 		if (audit_sockaddr(klen, kaddr))
  305 			return -ENOMEM;
  306 		if (copy_to_user(uaddr, kaddr, len))
  307 			return -EFAULT;
  308 	}
  309 	return 0;
  310 
  311 efault_end:
  312 	user_access_end();
  313 	return -EFAULT;
  314 }
  315 
  316 static struct kmem_cache *sock_inode_cachep __ro_after_init;
  317 
  318 static struct inode *sock_alloc_inode(struct super_block *sb)
  319 {
  320 	struct socket_alloc *ei;
  321 
  322 	ei = alloc_inode_sb(sb, sock_inode_cachep, GFP_KERNEL);
  323 	if (!ei)
  324 		return NULL;
  325 	init_waitqueue_head(&ei->socket.wq.wait);
  326 	ei->socket.wq.fasync_list = NULL;
  327 	ei->socket.wq.flags = 0;
  328 
  329 	ei->socket.state = SS_UNCONNECTED;
  330 	ei->socket.flags = 0;
  331 	ei->socket.ops = NULL;
  332 	ei->socket.sk = NULL;
  333 	ei->socket.file = NULL;
  334 
  335 	return &ei->vfs_inode;
  336 }
  337 
  338 static void sock_free_inode(struct inode *inode)
  339 {
  340 	struct socket_alloc *ei;
  341 
  342 	ei = container_of(inode, struct socket_alloc, vfs_inode);
  343 	kmem_cache_free(sock_inode_cachep, ei);
  344 }
  345 
  346 static void init_once(void *foo)
  347 {
  348 	struct socket_alloc *ei = (struct socket_alloc *)foo;
  349 
  350 	inode_init_once(&ei->vfs_inode);
  351 }
  352 
  353 static void init_inodecache(void)
  354 {
  355 	sock_inode_cachep = kmem_cache_create("sock_inode_cache",
  356 					      sizeof(struct socket_alloc),
  357 					      0,
  358 					      (SLAB_HWCACHE_ALIGN |
  359 					       SLAB_RECLAIM_ACCOUNT |
  360 					       SLAB_ACCOUNT),
  361 					      init_once);
  362 	BUG_ON(sock_inode_cachep == NULL);
  363 }
  364 
  365 static const struct super_operations sockfs_ops = {
  366 	.alloc_inode	= sock_alloc_inode,
  367 	.free_inode	= sock_free_inode,
  368 	.statfs		= simple_statfs,
  369 };
  370 
  371 /*
  372  * sockfs_dname() is called from d_path().
  373  */
  374 static char *sockfs_dname(struct dentry *dentry, char *buffer, int buflen)
  375 {
  376 	return dynamic_dname(buffer, buflen, "socket:[%lu]",
  377 				d_inode(dentry)->i_ino);
  378 }
  379 
  380 static const struct dentry_operations sockfs_dentry_operations = {
  381 	.d_dname  = sockfs_dname,
  382 };
  383 
  384 static int sockfs_xattr_get(const struct xattr_handler *handler,
  385 			    struct dentry *dentry, struct inode *inode,
  386 			    const char *suffix, void *value, size_t size)
  387 {
  388 	if (value) {
  389 		if (dentry->d_name.len + 1 > size)
  390 			return -ERANGE;
  391 		memcpy(value, dentry->d_name.name, dentry->d_name.len + 1);
  392 	}
  393 	return dentry->d_name.len + 1;
  394 }
  395 
  396 #define XATTR_SOCKPROTONAME_SUFFIX "sockprotoname"
  397 #define XATTR_NAME_SOCKPROTONAME (XATTR_SYSTEM_PREFIX XATTR_SOCKPROTONAME_SUFFIX)
  398 #define XATTR_NAME_SOCKPROTONAME_LEN (sizeof(XATTR_NAME_SOCKPROTONAME)-1)
  399 
  400 static const struct xattr_handler sockfs_xattr_handler = {
  401 	.name = XATTR_NAME_SOCKPROTONAME,
  402 	.get = sockfs_xattr_get,
  403 };
  404 
  405 static int sockfs_security_xattr_set(const struct xattr_handler *handler,
  406 				     struct mnt_idmap *idmap,
  407 				     struct dentry *dentry, struct inode *inode,
  408 				     const char *suffix, const void *value,
  409 				     size_t size, int flags)
  410 {
  411 	/* Handled by LSM. */
  412 	return -EAGAIN;
  413 }
  414 
  415 static const struct xattr_handler sockfs_security_xattr_handler = {
  416 	.prefix = XATTR_SECURITY_PREFIX,
  417 	.set = sockfs_security_xattr_set,
  418 };
  419 
  420 static const struct xattr_handler * const sockfs_xattr_handlers[] = {
  421 	&sockfs_xattr_handler,
  422 	&sockfs_security_xattr_handler,
  423 	NULL
  424 };
  425 
  426 static int sockfs_init_fs_context(struct fs_context *fc)
  427 {
  428 	struct pseudo_fs_context *ctx = init_pseudo(fc, SOCKFS_MAGIC);
  429 	if (!ctx)
  430 		return -ENOMEM;
  431 	ctx->ops = &sockfs_ops;
  432 	ctx->dops = &sockfs_dentry_operations;
  433 	ctx->xattr = sockfs_xattr_handlers;
  434 	return 0;
  435 }
  436 
  437 static struct vfsmount *sock_mnt __read_mostly;
  438 
  439 static struct file_system_type sock_fs_type = {
  440 	.name =		"sockfs",
  441 	.init_fs_context = sockfs_init_fs_context,
  442 	.kill_sb =	kill_anon_super,
  443 };
  444 
  445 /*
  446  *	Obtains the first available file descriptor and sets it up for use.
  447  *
  448  *	These functions create file structures and maps them to fd space
  449  *	of the current process. On success it returns file descriptor
  450  *	and file struct implicitly stored in sock->file.
  451  *	Note that another thread may close file descriptor before we return
  452  *	from this function. We use the fact that now we do not refer
  453  *	to socket after mapping. If one day we will need it, this
  454  *	function will increment ref. count on file by 1.
  455  *
  456  *	In any case returned fd MAY BE not valid!
  457  *	This race condition is unavoidable
  458  *	with shared fd spaces, we cannot solve it inside kernel,
  459  *	but we take care of internal coherence yet.
  460  */
  461 
  462 /**
  463  *	sock_alloc_file - Bind a &socket to a &file
  464  *	@sock: socket
  465  *	@flags: file status flags
  466  *	@dname: protocol name
  467  *
  468  *	Returns the &file bound with @sock, implicitly storing it
  469  *	in sock->file. If dname is %NULL, sets to "".
  470  *
  471  *	On failure @sock is released, and an ERR pointer is returned.
  472  *
  473  *	This function uses GFP_KERNEL internally.
  474  */
  475 
  476 struct file *sock_alloc_file(struct socket *sock, int flags, const char *dname)
  477 {
  478 	struct file *file;
  479 
  480 	if (!dname)
  481 		dname = sock->sk ? sock->sk->sk_prot_creator->name : "";
  482 
  483 	file = alloc_file_pseudo(SOCK_INODE(sock), sock_mnt, dname,
  484 				O_RDWR | (flags & O_NONBLOCK),
  485 				&socket_file_ops);
  486 	if (IS_ERR(file)) {
  487 		sock_release(sock);
  488 		return file;
  489 	}
  490 
  491 	file->f_mode |= FMODE_NOWAIT;
  492 	sock->file = file;
  493 	file->private_data = sock;
  494 	stream_open(SOCK_INODE(sock), file);
  495 	/*
  496 	 * Disable permission and pre-content events, but enable legacy
  497 	 * inotify events for legacy users.
  498 	 */
  499 	file_set_fsnotify_mode(file, FMODE_NONOTIFY_PERM);
  500 	return file;
  501 }
  502 EXPORT_SYMBOL(sock_alloc_file);
  503 
  504 static int sock_map_fd(struct socket *sock, int flags)
  505 {
  506 	struct file *newfile;
  507 	int fd = get_unused_fd_flags(flags);
  508 	if (unlikely(fd < 0)) {
  509 		sock_release(sock);
  510 		return fd;
  511 	}
  512 
  513 	newfile = sock_alloc_file(sock, flags, NULL);
  514 	if (!IS_ERR(newfile)) {
  515 		fd_install(fd, newfile);
  516 		return fd;
  517 	}
  518 
  519 	put_unused_fd(fd);
  520 	return PTR_ERR(newfile);
  521 }
  522 
  523 /**
  524  *	sock_from_file - Return the &socket bounded to @file.
  525  *	@file: file
  526  *
  527  *	On failure returns %NULL.
  528  */
  529 
  530 struct socket *sock_from_file(struct file *file)
  531 {
  532 	if (likely(file->f_op == &socket_file_ops))
  533 		return file->private_data;	/* set in sock_alloc_file */
  534 
  535 	return NULL;
  536 }
  537 EXPORT_SYMBOL(sock_from_file);
  538 
  539 /**
  540  *	sockfd_lookup - Go from a file number to its socket slot
  541  *	@fd: file handle
  542  *	@err: pointer to an error code return
  543  *
  544  *	The file handle passed in is locked and the socket it is bound
  545  *	to is returned. If an error occurs the err pointer is overwritten
  546  *	with a negative errno code and NULL is returned. The function checks
  547  *	for both invalid handles and passing a handle which is not a socket.
  548  *
  549  *	On a success the socket object pointer is returned.
  550  */
  551 
  552 struct socket *sockfd_lookup(int fd, int *err)
  553 {
  554 	struct file *file;
  555 	struct socket *sock;
  556 
  557 	file = fget(fd);
  558 	if (!file) {
  559 		*err = -EBADF;
  560 		return NULL;
  561 	}
  562 
  563 	sock = sock_from_file(file);
  564 	if (!sock) {
  565 		*err = -ENOTSOCK;
  566 		fput(file);
  567 	}
  568 	return sock;
  569 }
  570 EXPORT_SYMBOL(sockfd_lookup);
  571 
  572 static ssize_t sockfs_listxattr(struct dentry *dentry, char *buffer,
  573 				size_t size)
  574 {
  575 	ssize_t len;
  576 	ssize_t used = 0;
  577 
  578 	len = security_inode_listsecurity(d_inode(dentry), buffer, size);
  579 	if (len < 0)
  580 		return len;
  581 	used += len;
  582 	if (buffer) {
  583 		if (size < used)
  584 			return -ERANGE;
  585 		buffer += len;
  586 	}
  587 
  588 	len = (XATTR_NAME_SOCKPROTONAME_LEN + 1);
  589 	used += len;
  590 	if (buffer) {
  591 		if (size < used)
  592 			return -ERANGE;
  593 		memcpy(buffer, XATTR_NAME_SOCKPROTONAME, len);
  594 		buffer += len;
  595 	}
  596 
  597 	return used;
  598 }
  599 
  600 static int sockfs_setattr(struct mnt_idmap *idmap,
  601 			  struct dentry *dentry, struct iattr *iattr)
  602 {
  603 	int err = simple_setattr(&nop_mnt_idmap, dentry, iattr);
  604 
  605 	if (!err && (iattr->ia_valid & ATTR_UID)) {
  606 		struct socket *sock = SOCKET_I(d_inode(dentry));
  607 
  608 		if (sock->sk) {
  609 			/* Paired with READ_ONCE() in sk_uid() */
  610 			WRITE_ONCE(sock->sk->sk_uid, iattr->ia_uid);
  611 		} else {
  612 			err = -ENOENT;
  613 		}
  614 	}
  615 
  616 	return err;
  617 }
  618 
  619 static const struct inode_operations sockfs_inode_ops = {
  620 	.listxattr = sockfs_listxattr,
  621 	.setattr = sockfs_setattr,
  622 };
  623 
  624 /**
  625  *	sock_alloc - allocate a socket
  626  *
  627  *	Allocate a new inode and socket object. The two are bound together
  628  *	and initialised. The socket is then returned. If we are out of inodes
  629  *	NULL is returned. This functions uses GFP_KERNEL internally.
  630  */
  631 
  632 struct socket *sock_alloc(void)
  633 {
  634 	struct inode *inode;
  635 	struct socket *sock;
  636 
  637 	inode = new_inode_pseudo(sock_mnt->mnt_sb);
  638 	if (!inode)
  639 		return NULL;
  640 
  641 	sock = SOCKET_I(inode);
  642 
  643 	inode->i_ino = get_next_ino();
  644 	inode->i_mode = S_IFSOCK | S_IRWXUGO;
  645 	inode->i_uid = current_fsuid();
  646 	inode->i_gid = current_fsgid();
  647 	inode->i_op = &sockfs_inode_ops;
  648 
  649 	return sock;
  650 }
  651 EXPORT_SYMBOL(sock_alloc);
  652 
  653 static void __sock_release(struct socket *sock, struct inode *inode)
  654 {
  655 	const struct proto_ops *ops = READ_ONCE(sock->ops);
  656 
  657 	if (ops) {
  658 		struct module *owner = ops->owner;
  659 
  660 		if (inode)
  661 			inode_lock(inode);
  662 		ops->release(sock);
  663 		sock->sk = NULL;
  664 		if (inode)
  665 			inode_unlock(inode);
  666 		sock->ops = NULL;
  667 		module_put(owner);
  668 	}
  669 
  670 	if (sock->wq.fasync_list)
  671 		pr_err("%s: fasync list not empty!\n", __func__);
  672 
  673 	if (!sock->file) {
  674 		iput(SOCK_INODE(sock));
  675 		return;
  676 	}
  677 	WRITE_ONCE(sock->file, NULL);
  678 }
  679 
  680 /**
  681  *	sock_release - close a socket
  682  *	@sock: socket to close
  683  *
  684  *	The socket is released from the protocol stack if it has a release
  685  *	callback, and the inode is then released if the socket is bound to
  686  *	an inode not a file.
  687  */
  688 void sock_release(struct socket *sock)
  689 {
  690 	__sock_release(sock, NULL);
  691 }
  692 EXPORT_SYMBOL(sock_release);
  693 
  694 void __sock_tx_timestamp(__u32 tsflags, __u8 *tx_flags)
  695 {
  696 	u8 flags = *tx_flags;
  697 
  698 	if (tsflags & SOF_TIMESTAMPING_TX_HARDWARE)
  699 		flags |= SKBTX_HW_TSTAMP_NOBPF;
  700 
  701 	if (tsflags & SOF_TIMESTAMPING_TX_SOFTWARE)
  702 		flags |= SKBTX_SW_TSTAMP;
  703 
  704 	if (tsflags & SOF_TIMESTAMPING_TX_SCHED)
  705 		flags |= SKBTX_SCHED_TSTAMP;
  706 
  707 	if (tsflags & SOF_TIMESTAMPING_TX_COMPLETION)
  708 		flags |= SKBTX_COMPLETION_TSTAMP;
  709 
  710 	*tx_flags = flags;
  711 }
  712 EXPORT_SYMBOL(__sock_tx_timestamp);
  713 
  714 INDIRECT_CALLABLE_DECLARE(int inet_sendmsg(struct socket *, struct msghdr *,
  715 					   size_t));
  716 INDIRECT_CALLABLE_DECLARE(int inet6_sendmsg(struct socket *, struct msghdr *,
  717 					    size_t));
  718 
  719 static noinline void call_trace_sock_send_length(struct sock *sk, int ret,
  720 						 int flags)
  721 {
  722 	trace_sock_send_length(sk, ret, 0);
  723 }
  724 
  725 static inline int sock_sendmsg_nosec(struct socket *sock, struct msghdr *msg)
  726 {
  727 	int ret = INDIRECT_CALL_INET(READ_ONCE(sock->ops)->sendmsg, inet6_sendmsg,
  728 				     inet_sendmsg, sock, msg,
  729 				     msg_data_left(msg));
  730 	BUG_ON(ret == -EIOCBQUEUED);
  731 
  732 	if (trace_sock_send_length_enabled())
  733 		call_trace_sock_send_length(sock->sk, ret, 0);
  734 	return ret;
  735 }
  736 
  737 static int __sock_sendmsg(struct socket *sock, struct msghdr *msg)
  738 {
  739 	int err = security_socket_sendmsg(sock, msg,
  740 					  msg_data_left(msg));
  741 
  742 	return err ?: sock_sendmsg_nosec(sock, msg);
  743 }
  744 
  745 /**
  746  *	sock_sendmsg - send a message through @sock
  747  *	@sock: socket
  748  *	@msg: message to send
  749  *
  750  *	Sends @msg through @sock, passing through LSM.
  751  *	Returns the number of bytes sent, or an error code.
  752  */
  753 int sock_sendmsg(struct socket *sock, struct msghdr *msg)
  754 {
  755 	struct sockaddr_storage *save_addr = (struct sockaddr_storage *)msg->msg_name;
  756 	struct sockaddr_storage address;
  757 	int save_len = msg->msg_namelen;
  758 	int ret;
  759 
  760 	if (msg->msg_name) {
  761 		memcpy(&address, msg->msg_name, msg->msg_namelen);
  762 		msg->msg_name = &address;
  763 	}
  764 
  765 	ret = __sock_sendmsg(sock, msg);
  766 	msg->msg_name = save_addr;
  767 	msg->msg_namelen = save_len;
  768 
  769 	return ret;
  770 }
  771 EXPORT_SYMBOL(sock_sendmsg);
  772 
  773 /**
  774  *	kernel_sendmsg - send a message through @sock (kernel-space)
  775  *	@sock: socket
  776  *	@msg: message header
  777  *	@vec: kernel vec
  778  *	@num: vec array length
  779  *	@size: total message data size
  780  *
  781  *	Builds the message data with @vec and sends it through @sock.
  782  *	Returns the number of bytes sent, or an error code.
  783  */
  784 
  785 int kernel_sendmsg(struct socket *sock, struct msghdr *msg,
  786 		   struct kvec *vec, size_t num, size_t size)
  787 {
  788 	iov_iter_kvec(&msg->msg_iter, ITER_SOURCE, vec, num, size);
  789 	return sock_sendmsg(sock, msg);
  790 }
  791 EXPORT_SYMBOL(kernel_sendmsg);
  792 
  793 static bool skb_is_err_queue(const struct sk_buff *skb)
  794 {
  795 	/* Error-queue skbs are marked as PACKET_OUTGOING in
  796 	 * skb_set_err_queue() and use the destructor installed by
  797 	 * sock_queue_err_skb(). PACKET_OUTGOING alone is not unique:
  798 	 * AF_PACKET outgoing taps use the same pkt_type.
  799 	 */
  800 	return skb->pkt_type == PACKET_OUTGOING &&
  801 	       skb->destructor == sock_rmem_free;
  802 }
  803 
  804 /* On transmit, software and hardware timestamps are returned independently.
  805  * As the two skb clones share the hardware timestamp, which may be updated
  806  * before the software timestamp is received, a hardware TX timestamp may be
  807  * returned only if there is no software TX timestamp. Ignore false software
  808  * timestamps, which may be made in the __sock_recv_timestamp() call when the
  809  * option SO_TIMESTAMP_OLD(NS) is enabled on the socket, even when the skb has a
  810  * hardware timestamp.
  811  */
  812 static bool skb_is_swtx_tstamp(const struct sk_buff *skb, int false_tstamp)
  813 {
  814 	return skb->tstamp && !false_tstamp && skb_is_err_queue(skb);
  815 }
  816 
  817 static ktime_t get_timestamp(struct sock *sk, struct sk_buff *skb, int *if_index)
  818 {
  819 	bool cycles = READ_ONCE(sk->sk_tsflags) & SOF_TIMESTAMPING_BIND_PHC;
  820 	struct skb_shared_hwtstamps *shhwtstamps = skb_hwtstamps(skb);
  821 	struct net_device *orig_dev;
  822 	ktime_t hwtstamp;
  823 
  824 	rcu_read_lock();
  825 	orig_dev = dev_get_by_napi_id(skb_napi_id(skb));
  826 	if (orig_dev) {
  827 		*if_index = orig_dev->ifindex;
  828 		hwtstamp = netdev_get_tstamp(orig_dev, shhwtstamps, cycles);
  829 	} else {
  830 		hwtstamp = shhwtstamps->hwtstamp;
  831 	}
  832 	rcu_read_unlock();
  833 
  834 	return hwtstamp;
  835 }
  836 
  837 static void put_ts_pktinfo(struct msghdr *msg, struct sk_buff *skb,
  838 			   int if_index)
  839 {
  840 	struct scm_ts_pktinfo ts_pktinfo;
  841 	struct net_device *orig_dev;
  842 
  843 	if (!skb_mac_header_was_set(skb))
  844 		return;
  845 
  846 	memset(&ts_pktinfo, 0, sizeof(ts_pktinfo));
  847 
  848 	if (!if_index) {
  849 		rcu_read_lock();
  850 		orig_dev = dev_get_by_napi_id(skb_napi_id(skb));
  851 		if (orig_dev)
  852 			if_index = orig_dev->ifindex;
  853 		rcu_read_unlock();
  854 	}
  855 	ts_pktinfo.if_index = if_index;
  856 
  857 	ts_pktinfo.pkt_length = skb->len - skb_mac_offset(skb);
  858 	put_cmsg(msg, SOL_SOCKET, SCM_TIMESTAMPING_PKTINFO,
  859 		 sizeof(ts_pktinfo), &ts_pktinfo);
  860 }
  861 
  862 bool skb_has_tx_timestamp(struct sk_buff *skb, const struct sock *sk)
  863 {
  864 	const struct sock_exterr_skb *serr = SKB_EXT_ERR(skb);
  865 	u32 tsflags = READ_ONCE(sk->sk_tsflags);
  866 
  867 	if (serr->ee.ee_errno != ENOMSG ||
  868 	   serr->ee.ee_origin != SO_EE_ORIGIN_TIMESTAMPING)
  869 		return false;
  870 
  871 	/* software time stamp available and wanted */
  872 	if ((tsflags & SOF_TIMESTAMPING_SOFTWARE) && skb->tstamp)
  873 		return true;
  874 	/* hardware time stamps available and wanted */
  875 	return (tsflags & SOF_TIMESTAMPING_RAW_HARDWARE) &&
  876 		skb_hwtstamps(skb)->hwtstamp;
  877 }
  878 
  879 int skb_get_tx_timestamp(struct sk_buff *skb, struct sock *sk,
  880 			  struct timespec64 *ts)
  881 {
  882 	u32 tsflags = READ_ONCE(sk->sk_tsflags);
  883 	ktime_t hwtstamp;
  884 	int if_index = 0;
  885 
  886 	if ((tsflags & SOF_TIMESTAMPING_SOFTWARE) &&
  887 	    ktime_to_timespec64_cond(skb->tstamp, ts))
  888 		return SOF_TIMESTAMPING_TX_SOFTWARE;
  889 
  890 	if (!(tsflags & SOF_TIMESTAMPING_RAW_HARDWARE) ||
  891 	    skb_is_swtx_tstamp(skb, false))
  892 		return -ENOENT;
  893 
  894 	if (skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP_NETDEV)
  895 		hwtstamp = get_timestamp(sk, skb, &if_index);
  896 	else
  897 		hwtstamp = skb_hwtstamps(skb)->hwtstamp;
  898 
  899 	if (tsflags & SOF_TIMESTAMPING_BIND_PHC)
  900 		hwtstamp = ptp_convert_timestamp(&hwtstamp,
  901 						READ_ONCE(sk->sk_bind_phc));
  902 	if (!ktime_to_timespec64_cond(hwtstamp, ts))
  903 		return -ENOENT;
  904 
  905 	return SOF_TIMESTAMPING_TX_HARDWARE;
  906 }
  907 
  908 /*
  909  * called from sock_recv_timestamp() if sock_flag(sk, SOCK_RCVTSTAMP)
  910  */
  911 void __sock_recv_timestamp(struct msghdr *msg, struct sock *sk,
  912 	struct sk_buff *skb)
  913 {
  914 	int need_software_tstamp = sock_flag(sk, SOCK_RCVTSTAMP);
  915 	int new_tstamp = sock_flag(sk, SOCK_TSTAMP_NEW);
  916 	struct scm_timestamping_internal tss;
  917 	int empty = 1, false_tstamp = 0;
  918 	struct skb_shared_hwtstamps *shhwtstamps =
  919 		skb_hwtstamps(skb);
  920 	int if_index;
  921 	ktime_t hwtstamp;
  922 	u32 tsflags;
  923 
  924 	/* Race occurred between timestamp enabling and packet
  925 	   receiving.  Fill in the current time for now. */
  926 	if (need_software_tstamp && skb->tstamp == 0) {
  927 		__net_timestamp(skb);
  928 		false_tstamp = 1;
  929 	}
  930 
  931 	if (need_software_tstamp) {
  932 		if (!sock_flag(sk, SOCK_RCVTSTAMPNS)) {
  933 			if (new_tstamp) {
  934 				struct __kernel_sock_timeval tv;
  935 
  936 				skb_get_new_timestamp(skb, &tv);
  937 				put_cmsg(msg, SOL_SOCKET, SO_TIMESTAMP_NEW,
  938 					 sizeof(tv), &tv);
  939 			} else {
  940 				struct __kernel_old_timeval tv;
  941 
  942 				skb_get_timestamp(skb, &tv);
  943 				put_cmsg(msg, SOL_SOCKET, SO_TIMESTAMP_OLD,
  944 					 sizeof(tv), &tv);
  945 			}
  946 		} else {
  947 			if (new_tstamp) {
  948 				struct __kernel_timespec ts;
  949 
  950 				skb_get_new_timestampns(skb, &ts);
  951 				put_cmsg(msg, SOL_SOCKET, SO_TIMESTAMPNS_NEW,
  952 					 sizeof(ts), &ts);
  953 			} else {
  954 				struct __kernel_old_timespec ts;
  955 
  956 				skb_get_timestampns(skb, &ts);
  957 				put_cmsg(msg, SOL_SOCKET, SO_TIMESTAMPNS_OLD,
  958 					 sizeof(ts), &ts);
  959 			}
  960 		}
  961 	}
  962 
  963 	memset(&tss, 0, sizeof(tss));
  964 	tsflags = READ_ONCE(sk->sk_tsflags);
  965 	if ((tsflags & SOF_TIMESTAMPING_SOFTWARE &&
  966 	     (tsflags & SOF_TIMESTAMPING_RX_SOFTWARE ||
  967 	      skb_is_err_queue(skb) ||
  968 	      !(tsflags & SOF_TIMESTAMPING_OPT_RX_FILTER))) &&
  969 	    ktime_to_timespec64_cond(skb->tstamp, tss.ts + 0))
  970 		empty = 0;
  971 	if (shhwtstamps &&
  972 	    (tsflags & SOF_TIMESTAMPING_RAW_HARDWARE &&
  973 	     (tsflags & SOF_TIMESTAMPING_RX_HARDWARE ||
  974 	      skb_is_err_queue(skb) ||
  975 	      !(tsflags & SOF_TIMESTAMPING_OPT_RX_FILTER))) &&
  976 	    !skb_is_swtx_tstamp(skb, false_tstamp)) {
  977 		if_index = 0;
  978 		if (skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP_NETDEV)
  979 			hwtstamp = get_timestamp(sk, skb, &if_index);
  980 		else
  981 			hwtstamp = shhwtstamps->hwtstamp;
  982 
  983 		if (tsflags & SOF_TIMESTAMPING_BIND_PHC)
  984 			hwtstamp = ptp_convert_timestamp(&hwtstamp,
  985 							 READ_ONCE(sk->sk_bind_phc));
  986 
  987 		if (ktime_to_timespec64_cond(hwtstamp, tss.ts + 2)) {
  988 			empty = 0;
  989 
  990 			if ((tsflags & SOF_TIMESTAMPING_OPT_PKTINFO) &&
  991 			    !skb_is_err_queue(skb))
  992 				put_ts_pktinfo(msg, skb, if_index);
  993 		}
  994 	}
  995 	if (!empty) {
  996 		if (sock_flag(sk, SOCK_TSTAMP_NEW))
  997 			put_cmsg_scm_timestamping64(msg, &tss);
  998 		else
  999 			put_cmsg_scm_timestamping(msg, &tss);
 1000 
 1001 		if (skb_is_err_queue(skb) && skb->len &&
 1002 		    SKB_EXT_ERR(skb)->opt_stats)
 1003 			put_cmsg(msg, SOL_SOCKET, SCM_TIMESTAMPING_OPT_STATS,
 1004 				 skb->len, skb->data);
 1005 	}
 1006 }
 1007 EXPORT_SYMBOL_GPL(__sock_recv_timestamp);
 1008 
 1009 #ifdef CONFIG_WIRELESS
 1010 void __sock_recv_wifi_status(struct msghdr *msg, struct sock *sk,
 1011 	struct sk_buff *skb)
 1012 {
 1013 	int ack;
 1014 
 1015 	if (!sock_flag(sk, SOCK_WIFI_STATUS))
 1016 		return;
 1017 	if (!skb->wifi_acked_valid)
 1018 		return;
 1019 
 1020 	ack = skb->wifi_acked;
 1021 
 1022 	put_cmsg(msg, SOL_SOCKET, SCM_WIFI_STATUS, sizeof(ack), &ack);
 1023 }
 1024 EXPORT_SYMBOL_GPL(__sock_recv_wifi_status);
 1025 #endif
 1026 
 1027 static inline void sock_recv_drops(struct msghdr *msg, struct sock *sk,
 1028 				   struct sk_buff *skb)
 1029 {
 1030 	if (sock_flag(sk, SOCK_RXQ_OVFL) && skb && SOCK_SKB_CB(skb)->dropcount)
 1031 		put_cmsg(msg, SOL_SOCKET, SO_RXQ_OVFL,
 1032 			sizeof(__u32), &SOCK_SKB_CB(skb)->dropcount);
 1033 }
 1034 
 1035 static void sock_recv_mark(struct msghdr *msg, struct sock *sk,
 1036 			   struct sk_buff *skb)
 1037 {
 1038 	if (sock_flag(sk, SOCK_RCVMARK) && skb) {
 1039 		/* We must use a bounce buffer for CONFIG_HARDENED_USERCOPY=y */
 1040 		__u32 mark = skb->mark;
 1041 
 1042 		put_cmsg(msg, SOL_SOCKET, SO_MARK, sizeof(__u32), &mark);
 1043 	}
 1044 }
 1045 
 1046 static void sock_recv_priority(struct msghdr *msg, struct sock *sk,
 1047 			       struct sk_buff *skb)
 1048 {
 1049 	if (sock_flag(sk, SOCK_RCVPRIORITY) && skb) {
 1050 		__u32 priority = skb->priority;
 1051 
 1052 		put_cmsg(msg, SOL_SOCKET, SO_PRIORITY, sizeof(__u32), &priority);
 1053 	}
 1054 }
 1055 
 1056 void __sock_recv_cmsgs(struct msghdr *msg, struct sock *sk,
 1057 		       struct sk_buff *skb)
 1058 {
 1059 	sock_recv_timestamp(msg, sk, skb);
 1060 	sock_recv_drops(msg, sk, skb);
 1061 	sock_recv_mark(msg, sk, skb);
 1062 	sock_recv_priority(msg, sk, skb);
 1063 }
 1064 EXPORT_SYMBOL_GPL(__sock_recv_cmsgs);
 1065 
 1066 INDIRECT_CALLABLE_DECLARE(int inet_recvmsg(struct socket *, struct msghdr *,
 1067 					   size_t, int));
 1068 INDIRECT_CALLABLE_DECLARE(int inet6_recvmsg(struct socket *, struct msghdr *,
 1069 					    size_t, int));
 1070 
 1071 static noinline void call_trace_sock_recv_length(struct sock *sk, int ret, int flags)
 1072 {
 1073 	trace_sock_recv_length(sk, ret, flags);
 1074 }
 1075 
 1076 static inline int sock_recvmsg_nosec(struct socket *sock, struct msghdr *msg,
 1077 				     int flags)
 1078 {
 1079 	int ret = INDIRECT_CALL_INET(READ_ONCE(sock->ops)->recvmsg,
 1080 				     inet6_recvmsg,
 1081 				     inet_recvmsg, sock, msg,
 1082 				     msg_data_left(msg), flags);
 1083 	if (trace_sock_recv_length_enabled())
 1084 		call_trace_sock_recv_length(sock->sk, ret, flags);
 1085 	return ret;
 1086 }
 1087 
 1088 /**
 1089  *	sock_recvmsg - receive a message from @sock
 1090  *	@sock: socket
 1091  *	@msg: message to receive
 1092  *	@flags: message flags
 1093  *
 1094  *	Receives @msg from @sock, passing through LSM. Returns the total number
 1095  *	of bytes received, or an error.
 1096  */
 1097 int sock_recvmsg(struct socket *sock, struct msghdr *msg, int flags)
 1098 {
 1099 	int err = security_socket_recvmsg(sock, msg, msg_data_left(msg), flags);
 1100 
 1101 	return err ?: sock_recvmsg_nosec(sock, msg, flags);
 1102 }
 1103 EXPORT_SYMBOL(sock_recvmsg);
 1104 
 1105 /**
 1106  *	kernel_recvmsg - Receive a message from a socket (kernel space)
 1107  *	@sock: The socket to receive the message from
 1108  *	@msg: Received message
 1109  *	@vec: Input s/g array for message data
 1110  *	@num: Size of input s/g array
 1111  *	@size: Number of bytes to read
 1112  *	@flags: Message flags (MSG_DONTWAIT, etc...)
 1113  *
 1114  *	On return the msg structure contains the scatter/gather array passed in the
 1115  *	vec argument. The array is modified so that it consists of the unfilled
 1116  *	portion of the original array.
 1117  *
 1118  *	The returned value is the total number of bytes received, or an error.
 1119  */
 1120 
 1121 int kernel_recvmsg(struct socket *sock, struct msghdr *msg,
 1122 		   struct kvec *vec, size_t num, size_t size, int flags)
 1123 {
 1124 	msg->msg_control_is_user = false;
 1125 	iov_iter_kvec(&msg->msg_iter, ITER_DEST, vec, num, size);
 1126 	return sock_recvmsg(sock, msg, flags);
 1127 }
 1128 EXPORT_SYMBOL(kernel_recvmsg);
 1129 
 1130 static ssize_t sock_splice_read(struct file *file, loff_t *ppos,
 1131 				struct pipe_inode_info *pipe, size_t len,
 1132 				unsigned int flags)
 1133 {
 1134 	struct socket *sock = file->private_data;
 1135 	const struct proto_ops *ops;
 1136 
 1137 	ops = READ_ONCE(sock->ops);
 1138 	if (unlikely(!ops->splice_read))
 1139 		return copy_splice_read(file, ppos, pipe, len, flags);
 1140 
 1141 	return ops->splice_read(sock, ppos, pipe, len, flags);
 1142 }
 1143 
 1144 static void sock_splice_eof(struct file *file)
 1145 {
 1146 	struct socket *sock = file->private_data;
 1147 	const struct proto_ops *ops;
 1148 
 1149 	ops = READ_ONCE(sock->ops);
 1150 	if (ops->splice_eof)
 1151 		ops->splice_eof(sock);
 1152 }
 1153 
 1154 static ssize_t sock_read_iter(struct kiocb *iocb, struct iov_iter *to)
 1155 {
 1156 	struct file *file = iocb->ki_filp;
 1157 	struct socket *sock = file->private_data;
 1158 	struct msghdr msg = {.msg_iter = *to,
 1159 			     .msg_iocb = iocb};
 1160 	ssize_t res;
 1161 
 1162 	if (file->f_flags & O_NONBLOCK || (iocb->ki_flags & IOCB_NOWAIT))
 1163 		msg.msg_flags = MSG_DONTWAIT;
 1164 
 1165 	if (iocb->ki_pos != 0)
 1166 		return -ESPIPE;
 1167 
 1168 	if (!iov_iter_count(to))	/* Match SYS5 behaviour */
 1169 		return 0;
 1170 
 1171 	res = sock_recvmsg(sock, &msg, msg.msg_flags);
 1172 	*to = msg.msg_iter;
 1173 	return res;
 1174 }
 1175 
 1176 static ssize_t sock_write_iter(struct kiocb *iocb, struct iov_iter *from)
 1177 {
 1178 	struct file *file = iocb->ki_filp;
 1179 	struct socket *sock = file->private_data;
 1180 	struct msghdr msg = {.msg_iter = *from,
 1181 			     .msg_iocb = iocb};
 1182 	ssize_t res;
 1183 
 1184 	if (iocb->ki_pos != 0)
 1185 		return -ESPIPE;
 1186 
 1187 	if (file->f_flags & O_NONBLOCK || (iocb->ki_flags & IOCB_NOWAIT))
 1188 		msg.msg_flags = MSG_DONTWAIT;
 1189 
 1190 	if (sock->type == SOCK_SEQPACKET)
 1191 		msg.msg_flags |= MSG_EOR;
 1192 
 1193 	if (iocb->ki_flags & IOCB_NOSIGNAL)
 1194 		msg.msg_flags |= MSG_NOSIGNAL;
 1195 
 1196 	res = __sock_sendmsg(sock, &msg);
 1197 	*from = msg.msg_iter;
 1198 	return res;
 1199 }
 1200 
 1201 /*
 1202  * Atomic setting of ioctl hooks to avoid race
 1203  * with module unload.
 1204  */
 1205 
 1206 static DEFINE_MUTEX(br_ioctl_mutex);
 1207 static int (*br_ioctl_hook)(struct net *net, unsigned int cmd,
 1208 			    void __user *uarg);
 1209 
 1210 void brioctl_set(int (*hook)(struct net *net, unsigned int cmd,
 1211 			     void __user *uarg))
 1212 {
 1213 	mutex_lock(&br_ioctl_mutex);
 1214 	br_ioctl_hook = hook;
 1215 	mutex_unlock(&br_ioctl_mutex);
 1216 }
 1217 EXPORT_SYMBOL(brioctl_set);
 1218 
 1219 int br_ioctl_call(struct net *net, unsigned int cmd, void __user *uarg)
 1220 {
 1221 	int err = -ENOPKG;
 1222 
 1223 	if (!br_ioctl_hook)
 1224 		request_module("bridge");
 1225 
 1226 	mutex_lock(&br_ioctl_mutex);
 1227 	if (br_ioctl_hook)
 1228 		err = br_ioctl_hook(net, cmd, uarg);
 1229 	mutex_unlock(&br_ioctl_mutex);
 1230 
 1231 	return err;
 1232 }
 1233 
 1234 static DEFINE_MUTEX(vlan_ioctl_mutex);
 1235 static int (*vlan_ioctl_hook) (struct net *, void __user *arg);
 1236 
 1237 void vlan_ioctl_set(int (*hook) (struct net *, void __user *))
 1238 {
 1239 	mutex_lock(&vlan_ioctl_mutex);
 1240 	vlan_ioctl_hook = hook;
 1241 	mutex_unlock(&vlan_ioctl_mutex);
 1242 }
 1243 EXPORT_SYMBOL(vlan_ioctl_set);
 1244 
 1245 static long sock_do_ioctl(struct net *net, struct socket *sock,
 1246 			  unsigned int cmd, unsigned long arg)
 1247 {
 1248 	const struct proto_ops *ops = READ_ONCE(sock->ops);
 1249 	struct ifreq ifr;
 1250 	bool need_copyout;
 1251 	int err;
 1252 	void __user *argp = (void __user *)arg;
 1253 	void __user *data;
 1254 
 1255 	err = ops->ioctl(sock, cmd, arg);
 1256 
 1257 	/*
 1258 	 * If this ioctl is unknown try to hand it down
 1259 	 * to the NIC driver.
 1260 	 */
 1261 	if (err != -ENOIOCTLCMD)
 1262 		return err;
 1263 
 1264 	if (!is_socket_ioctl_cmd(cmd))
 1265 		return -ENOTTY;
 1266 
 1267 	if (get_user_ifreq(&ifr, &data, argp))
 1268 		return -EFAULT;
 1269 	err = dev_ioctl(net, cmd, &ifr, data, &need_copyout);
 1270 	if (!err && need_copyout)
 1271 		if (put_user_ifreq(&ifr, argp))
 1272 			return -EFAULT;
 1273 
 1274 	return err;
 1275 }
 1276 
 1277 /*
 1278  *	With an ioctl, arg may well be a user mode pointer, but we don't know
 1279  *	what to do with it - that's up to the protocol still.
 1280  */
 1281 
 1282 static long sock_ioctl(struct file *file, unsigned cmd, unsigned long arg)
 1283 {
 1284 	const struct proto_ops  *ops;
 1285 	struct socket *sock;
 1286 	struct sock *sk;
 1287 	void __user *argp = (void __user *)arg;
 1288 	int pid, err;
 1289 	struct net *net;
 1290 
 1291 	sock = file->private_data;
 1292 	ops = READ_ONCE(sock->ops);
 1293 	sk = sock->sk;
 1294 	net = sock_net(sk);
 1295 	if (unlikely(cmd >= SIOCDEVPRIVATE && cmd <= (SIOCDEVPRIVATE + 15))) {
 1296 		struct ifreq ifr;
 1297 		void __user *data;
 1298 		bool need_copyout;
 1299 		if (get_user_ifreq(&ifr, &data, argp))
 1300 			return -EFAULT;
 1301 		err = dev_ioctl(net, cmd, &ifr, data, &need_copyout);
 1302 		if (!err && need_copyout)
 1303 			if (put_user_ifreq(&ifr, argp))
 1304 				return -EFAULT;
 1305 	} else
 1306 #ifdef CONFIG_WEXT_CORE
 1307 	if (cmd >= SIOCIWFIRST && cmd <= SIOCIWLAST) {
 1308 		err = wext_handle_ioctl(net, cmd, argp);
 1309 	} else
 1310 #endif
 1311 		switch (cmd) {
 1312 		case FIOSETOWN:
 1313 		case SIOCSPGRP:
 1314 			err = -EFAULT;
 1315 			if (get_user(pid, (int __user *)argp))
 1316 				break;
 1317 			err = f_setown(sock->file, pid, 1);
 1318 			break;
 1319 		case FIOGETOWN:
 1320 		case SIOCGPGRP:
 1321 			err = put_user(f_getown(sock->file),
 1322 				       (int __user *)argp);
 1323 			break;
 1324 		case SIOCGIFBR:
 1325 		case SIOCSIFBR:
 1326 		case SIOCBRADDBR:
 1327 		case SIOCBRDELBR:
 1328 		case SIOCBRADDIF:
 1329 		case SIOCBRDELIF:
 1330 			err = br_ioctl_call(net, cmd, argp);
 1331 			break;
 1332 		case SIOCGIFVLAN:
 1333 		case SIOCSIFVLAN:
 1334 			err = -ENOPKG;
 1335 			if (!vlan_ioctl_hook)
 1336 				request_module("8021q");
 1337 
 1338 			mutex_lock(&vlan_ioctl_mutex);
 1339 			if (vlan_ioctl_hook)
 1340 				err = vlan_ioctl_hook(net, argp);
 1341 			mutex_unlock(&vlan_ioctl_mutex);
 1342 			break;
 1343 		case SIOCGSKNS:
 1344 			err = -EPERM;
 1345 			if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
 1346 				break;
 1347 
 1348 			err = open_related_ns(&net->ns, get_net_ns);
 1349 			break;
 1350 		case SIOCGSTAMP_OLD:
 1351 		case SIOCGSTAMPNS_OLD:
 1352 			if (!ops->gettstamp) {
 1353 				err = -ENOIOCTLCMD;
 1354 				break;
 1355 			}
 1356 			err = ops->gettstamp(sock, argp,
 1357 					     cmd == SIOCGSTAMP_OLD,
 1358 					     !IS_ENABLED(CONFIG_64BIT));
 1359 			break;
 1360 		case SIOCGSTAMP_NEW:
 1361 		case SIOCGSTAMPNS_NEW:
 1362 			if (!ops->gettstamp) {
 1363 				err = -ENOIOCTLCMD;
 1364 				break;
 1365 			}
 1366 			err = ops->gettstamp(sock, argp,
 1367 					     cmd == SIOCGSTAMP_NEW,
 1368 					     false);
 1369 			break;
 1370 
 1371 		case SIOCGIFCONF:
 1372 			err = dev_ifconf(net, argp);
 1373 			break;
 1374 
 1375 		default:
 1376 			err = sock_do_ioctl(net, sock, cmd, arg);
 1377 			break;
 1378 		}
 1379 	return err;
 1380 }
 1381 
 1382 /**
 1383  *	sock_create_lite - creates a socket
 1384  *	@family: protocol family (AF_INET, ...)
 1385  *	@type: communication type (SOCK_STREAM, ...)
 1386  *	@protocol: protocol (0, ...)
 1387  *	@res: new socket
 1388  *
 1389  *	Creates a new socket and assigns it to @res, passing through LSM.
 1390  *	The new socket initialization is not complete, see kernel_accept().
 1391  *	Returns 0 or an error. On failure @res is set to %NULL.
 1392  *	This function internally uses GFP_KERNEL.
 1393  */
 1394 
 1395 int sock_create_lite(int family, int type, int protocol, struct socket **res)
 1396 {
 1397 	int err;
 1398 	struct socket *sock = NULL;
 1399 
 1400 	err = security_socket_create(family, type, protocol, 1);
 1401 	if (err)
 1402 		goto out;
 1403 
 1404 	sock = sock_alloc();
 1405 	if (!sock) {
 1406 		err = -ENOMEM;
 1407 		goto out;
 1408 	}
 1409 
 1410 	sock->type = type;
 1411 	err = security_socket_post_create(sock, family, type, protocol, 1);
 1412 	if (err)
 1413 		goto out_release;
 1414 
 1415 out:
 1416 	*res = sock;
 1417 	return err;
 1418 out_release:
 1419 	sock_release(sock);
 1420 	sock = NULL;
 1421 	goto out;
 1422 }
 1423 EXPORT_SYMBOL(sock_create_lite);
 1424 
 1425 /* No kernel lock held - perfect */
 1426 static __poll_t sock_poll(struct file *file, poll_table *wait)
 1427 {
 1428 	struct socket *sock = file->private_data;
 1429 	const struct proto_ops *ops = READ_ONCE(sock->ops);
 1430 	__poll_t events = poll_requested_events(wait), flag = 0;
 1431 
 1432 	if (!ops->poll)
 1433 		return 0;
 1434 
 1435 	if (sk_can_busy_loop(sock->sk)) {
 1436 		/* poll once if requested by the syscall */
 1437 		if (events & POLL_BUSY_LOOP)
 1438 			sk_busy_loop(sock->sk, 1);
 1439 
 1440 		/* if this socket can poll_ll, tell the system call */
 1441 		flag = POLL_BUSY_LOOP;
 1442 	}
 1443 
 1444 	return ops->poll(file, sock, wait) | flag;
 1445 }
 1446 
 1447 static int sock_mmap(struct file *file, struct vm_area_struct *vma)
 1448 {
 1449 	struct socket *sock = file->private_data;
 1450 
 1451 	return READ_ONCE(sock->ops)->mmap(file, sock, vma);
 1452 }
 1453 
 1454 static int sock_close(struct inode *inode, struct file *filp)
 1455 {
 1456 	__sock_release(SOCKET_I(inode), inode);
 1457 	return 0;
 1458 }
 1459 
 1460 /*
 1461  *	Update the socket async list
 1462  *
 1463  *	Fasync_list locking strategy.
 1464  *
 1465  *	1. fasync_list is modified only under process context socket lock
 1466  *	   i.e. under semaphore.
 1467  *	2. fasync_list is used under read_lock(&sk->sk_callback_lock)
 1468  *	   or under socket lock
 1469  */
 1470 
 1471 static int sock_fasync(int fd, struct file *filp, int on)
 1472 {
 1473 	struct socket *sock = filp->private_data;
 1474 	struct sock *sk = sock->sk;
 1475 	struct socket_wq *wq = &sock->wq;
 1476 
 1477 	if (sk == NULL)
 1478 		return -EINVAL;
 1479 
 1480 	lock_sock(sk);
 1481 	fasync_helper(fd, filp, on, &wq->fasync_list);
 1482 
 1483 	if (!wq->fasync_list)
 1484 		sock_reset_flag(sk, SOCK_FASYNC);
 1485 	else
 1486 		sock_set_flag(sk, SOCK_FASYNC);
 1487 
 1488 	release_sock(sk);
 1489 	return 0;
 1490 }
 1491 
 1492 /* This function may be called only under rcu_lock */
 1493 
 1494 int sock_wake_async(struct socket_wq *wq, int how, int band)
 1495 {
 1496 	if (!wq || !wq->fasync_list)
 1497 		return -1;
 1498 
 1499 	switch (how) {
 1500 	case SOCK_WAKE_WAITD:
 1501 		if (test_bit(SOCKWQ_ASYNC_WAITDATA, &wq->flags))
 1502 			break;
 1503 		goto call_kill;
 1504 	case SOCK_WAKE_SPACE:
 1505 		if (!test_and_clear_bit(SOCKWQ_ASYNC_NOSPACE, &wq->flags))
 1506 			break;
 1507 		fallthrough;
 1508 	case SOCK_WAKE_IO:
 1509 call_kill:
 1510 		kill_fasync(&wq->fasync_list, SIGIO, band);
 1511 		break;
 1512 	case SOCK_WAKE_URG:
 1513 		kill_fasync(&wq->fasync_list, SIGURG, band);
 1514 	}
 1515 
 1516 	return 0;
 1517 }
 1518 EXPORT_SYMBOL(sock_wake_async);
 1519 
 1520 /**
 1521  *	__sock_create - creates a socket
 1522  *	@net: net namespace
 1523  *	@family: protocol family (AF_INET, ...)
 1524  *	@type: communication type (SOCK_STREAM, ...)
 1525  *	@protocol: protocol (0, ...)
 1526  *	@res: new socket
 1527  *	@kern: boolean for kernel space sockets
 1528  *
 1529  *	Creates a new socket and assigns it to @res, passing through LSM.
 1530  *	Returns 0 or an error. On failure @res is set to %NULL. @kern must
 1531  *	be set to true if the socket resides in kernel space.
 1532  *	This function internally uses GFP_KERNEL.
 1533  */
 1534 
 1535 int __sock_create(struct net *net, int family, int type, int protocol,
 1536 			 struct socket **res, int kern)
 1537 {
 1538 	int err;
 1539 	struct socket *sock;
 1540 	const struct net_proto_family *pf;
 1541 
 1542 	/*
 1543 	 *      Check protocol is in range
 1544 	 */
 1545 	if (family < 0 || family >= NPROTO)
 1546 		return -EAFNOSUPPORT;
 1547 	if (type < 0 || type >= SOCK_MAX)
 1548 		return -EINVAL;
 1549 
 1550 	/* Compatibility.
 1551 
 1552 	   This uglymoron is moved from INET layer to here to avoid
 1553 	   deadlock in module load.
 1554 	 */
 1555 	if (family == PF_INET && type == SOCK_PACKET) {
 1556 		pr_info_once("%s uses obsolete (PF_INET,SOCK_PACKET)\n",
 1557 			     current->comm);
 1558 		family = PF_PACKET;
 1559 	}
 1560 
 1561 	err = security_socket_create(family, type, protocol, kern);
 1562 	if (err)
 1563 		return err;
 1564 
 1565 	/*
 1566 	 *	Allocate the socket and allow the family to set things up. if
 1567 	 *	the protocol is 0, the family is instructed to select an appropriate
 1568 	 *	default.
 1569 	 */
 1570 	sock = sock_alloc();
 1571 	if (!sock) {
 1572 		net_warn_ratelimited("socket: no more sockets\n");
 1573 		return -ENFILE;	/* Not exactly a match, but its the
 1574 				   closest posix thing */
 1575 	}
 1576 
 1577 	sock->type = type;
 1578 
 1579 #ifdef CONFIG_MODULES
 1580 	/* Attempt to load a protocol module if the find failed.
 1581 	 *
 1582 	 * 12/09/1996 Marcin: But! this makes REALLY only sense, if the user
 1583 	 * requested real, full-featured networking support upon configuration.
 1584 	 * Otherwise module support will break!
 1585 	 */
 1586 	if (rcu_access_pointer(net_families[family]) == NULL)
 1587 		request_module("net-pf-%d", family);
 1588 #endif
 1589 
 1590 	rcu_read_lock();
 1591 	pf = rcu_dereference(net_families[family]);
 1592 	err = -EAFNOSUPPORT;
 1593 	if (!pf)
 1594 		goto out_release;
 1595 
 1596 	/*
 1597 	 * We will call the ->create function, that possibly is in a loadable
 1598 	 * module, so we have to bump that loadable module refcnt first.
 1599 	 */
 1600 	if (!try_module_get(pf->owner))
 1601 		goto out_release;
 1602 
 1603 	/* Now protected by module ref count */
 1604 	rcu_read_unlock();
 1605 
 1606 	err = pf->create(net, sock, protocol, kern);
 1607 	if (err < 0) {
 1608 		/* ->create should release the allocated sock->sk object on error
 1609 		 * and make sure sock->sk is set to NULL to avoid use-after-free
 1610 		 */
 1611 		DEBUG_NET_WARN_ONCE(sock->sk,
 1612 				    "%ps must clear sock->sk on failure, family: %d, type: %d, protocol: %d\n",
 1613 				    pf->create, family, type, protocol);
 1614 		goto out_module_put;
 1615 	}
 1616 
 1617 	/*
 1618 	 * Now to bump the refcnt of the [loadable] module that owns this
 1619 	 * socket at sock_release time we decrement its refcnt.
 1620 	 */
 1621 	if (!try_module_get(sock->ops->owner))
 1622 		goto out_module_busy;
 1623 
 1624 	/*
 1625 	 * Now that we're done with the ->create function, the [loadable]
 1626 	 * module can have its refcnt decremented
 1627 	 */
 1628 	module_put(pf->owner);
 1629 	err = security_socket_post_create(sock, family, type, protocol, kern);
 1630 	if (err)
 1631 		goto out_sock_release;
 1632 	*res = sock;
 1633 
 1634 	return 0;
 1635 
 1636 out_module_busy:
 1637 	err = -EAFNOSUPPORT;
 1638 out_module_put:
 1639 	sock->ops = NULL;
 1640 	module_put(pf->owner);
 1641 out_sock_release:
 1642 	sock_release(sock);
 1643 	return err;
 1644 
 1645 out_release:
 1646 	rcu_read_unlock();
 1647 	goto out_sock_release;
 1648 }
 1649 EXPORT_SYMBOL(__sock_create);
 1650 
 1651 /**
 1652  *	sock_create - creates a socket
 1653  *	@family: protocol family (AF_INET, ...)
 1654  *	@type: communication type (SOCK_STREAM, ...)
 1655  *	@protocol: protocol (0, ...)
 1656  *	@res: new socket
 1657  *
 1658  *	A wrapper around __sock_create().
 1659  *	Returns 0 or an error. This function internally uses GFP_KERNEL.
 1660  */
 1661 
 1662 int sock_create(int family, int type, int protocol, struct socket **res)
 1663 {
 1664 	return __sock_create(current->nsproxy->net_ns, family, type, protocol, res, 0);
 1665 }
 1666 EXPORT_SYMBOL(sock_create);
 1667 
 1668 /**
 1669  *	sock_create_kern - creates a socket (kernel space)
 1670  *	@net: net namespace
 1671  *	@family: protocol family (AF_INET, ...)
 1672  *	@type: communication type (SOCK_STREAM, ...)
 1673  *	@protocol: protocol (0, ...)
 1674  *	@res: new socket
 1675  *
 1676  *	A wrapper around __sock_create().
 1677  *	Returns 0 or an error. This function internally uses GFP_KERNEL.
 1678  */
 1679 
 1680 int sock_create_kern(struct net *net, int family, int type, int protocol, struct socket **res)
 1681 {
 1682 	return __sock_create(net, family, type, protocol, res, 1);
 1683 }
 1684 EXPORT_SYMBOL(sock_create_kern);
 1685 
 1686 static struct socket *__sys_socket_create(int family, int type, int protocol)
 1687 {
 1688 	struct socket *sock;
 1689 	int retval;
 1690 
 1691 	/* Check the SOCK_* constants for consistency.  */
 1692 	BUILD_BUG_ON(SOCK_CLOEXEC != O_CLOEXEC);
 1693 	BUILD_BUG_ON((SOCK_MAX | SOCK_TYPE_MASK) != SOCK_TYPE_MASK);
 1694 	BUILD_BUG_ON(SOCK_CLOEXEC & SOCK_TYPE_MASK);
 1695 	BUILD_BUG_ON(SOCK_NONBLOCK & SOCK_TYPE_MASK);
 1696 
 1697 	if ((type & ~SOCK_TYPE_MASK) & ~(SOCK_CLOEXEC | SOCK_NONBLOCK))
 1698 		return ERR_PTR(-EINVAL);
 1699 	type &= SOCK_TYPE_MASK;
 1700 
 1701 	retval = sock_create(family, type, protocol, &sock);
 1702 	if (retval < 0)
 1703 		return ERR_PTR(retval);
 1704 
 1705 	return sock;
 1706 }
 1707 
 1708 struct file *__sys_socket_file(int family, int type, int protocol)
 1709 {
 1710 	struct socket *sock;
 1711 	int flags;
 1712 
 1713 	sock = __sys_socket_create(family, type, protocol);
 1714 	if (IS_ERR(sock))
 1715 		return ERR_CAST(sock);
 1716 
 1717 	flags = type & ~SOCK_TYPE_MASK;
 1718 	if (SOCK_NONBLOCK != O_NONBLOCK && (flags & SOCK_NONBLOCK))
 1719 		flags = (flags & ~SOCK_NONBLOCK) | O_NONBLOCK;
 1720 
 1721 	return sock_alloc_file(sock, flags, NULL);
 1722 }
 1723 
 1724 /*	A hook for bpf progs to attach to and update socket protocol.
 1725  *
 1726  *	A static noinline declaration here could cause the compiler to
 1727  *	optimize away the function. A global noinline declaration will
 1728  *	keep the definition, but may optimize away the callsite.
 1729  *	Therefore, __weak is needed to ensure that the call is still
 1730  *	emitted, by telling the compiler that we don't know what the
 1731  *	function might eventually be.
 1732  */
 1733 
 1734 __bpf_hook_start();
 1735 
 1736 __weak noinline int update_socket_protocol(int family, int type, int protocol)
 1737 {
 1738 	return protocol;
 1739 }
 1740 
 1741 __bpf_hook_end();
 1742 
 1743 int __sys_socket(int family, int type, int protocol)
 1744 {
 1745 	struct socket *sock;
 1746 	int flags;
 1747 
 1748 	sock = __sys_socket_create(family, type,
 1749 				   update_socket_protocol(family, type, protocol));
 1750 	if (IS_ERR(sock))
 1751 		return PTR_ERR(sock);
 1752 
 1753 	flags = type & ~SOCK_TYPE_MASK;
 1754 	if (SOCK_NONBLOCK != O_NONBLOCK && (flags & SOCK_NONBLOCK))
 1755 		flags = (flags & ~SOCK_NONBLOCK) | O_NONBLOCK;
 1756 
 1757 	return sock_map_fd(sock, flags & (O_CLOEXEC | O_NONBLOCK));
 1758 }
 1759 
 1760 SYSCALL_DEFINE3(socket, int, family, int, type, int, protocol)
 1761 {
 1762 	return __sys_socket(family, type, protocol);
 1763 }
 1764 
 1765 /*
 1766  *	Create a pair of connected sockets.
 1767  */
 1768 
 1769 int __sys_socketpair(int family, int type, int protocol, int __user *usockvec)
 1770 {
 1771 	struct socket *sock1, *sock2;
 1772 	int fd1, fd2, err;
 1773 	struct file *newfile1, *newfile2;
 1774 	int flags;
 1775 
 1776 	flags = type & ~SOCK_TYPE_MASK;
 1777 	if (flags & ~(SOCK_CLOEXEC | SOCK_NONBLOCK))
 1778 		return -EINVAL;
 1779 	type &= SOCK_TYPE_MASK;
 1780 
 1781 	if (SOCK_NONBLOCK != O_NONBLOCK && (flags & SOCK_NONBLOCK))
 1782 		flags = (flags & ~SOCK_NONBLOCK) | O_NONBLOCK;
 1783 
 1784 	/*
 1785 	 * reserve descriptors and make sure we won't fail
 1786 	 * to return them to userland.
 1787 	 */
 1788 	fd1 = get_unused_fd_flags(flags);
 1789 	if (unlikely(fd1 < 0))
 1790 		return fd1;
 1791 
 1792 	fd2 = get_unused_fd_flags(flags);
 1793 	if (unlikely(fd2 < 0)) {
 1794 		put_unused_fd(fd1);
 1795 		return fd2;
 1796 	}
 1797 
 1798 	err = put_user(fd1, &usockvec[0]);
 1799 	if (err)
 1800 		goto out;
 1801 
 1802 	err = put_user(fd2, &usockvec[1]);
 1803 	if (err)
 1804 		goto out;
 1805 
 1806 	/*
 1807 	 * Obtain the first socket and check if the underlying protocol
 1808 	 * supports the socketpair call.
 1809 	 */
 1810 
 1811 	err = sock_create(family, type, protocol, &sock1);
 1812 	if (unlikely(err < 0))
 1813 		goto out;
 1814 
 1815 	err = sock_create(family, type, protocol, &sock2);
 1816 	if (unlikely(err < 0)) {
 1817 		sock_release(sock1);
 1818 		goto out;
 1819 	}
 1820 
 1821 	err = security_socket_socketpair(sock1, sock2);
 1822 	if (unlikely(err)) {
 1823 		sock_release(sock2);
 1824 		sock_release(sock1);
 1825 		goto out;
 1826 	}
 1827 
 1828 	err = READ_ONCE(sock1->ops)->socketpair(sock1, sock2);
 1829 	if (unlikely(err < 0)) {
 1830 		sock_release(sock2);
 1831 		sock_release(sock1);
 1832 		goto out;
 1833 	}
 1834 
 1835 	newfile1 = sock_alloc_file(sock1, flags, NULL);
 1836 	if (IS_ERR(newfile1)) {
 1837 		err = PTR_ERR(newfile1);
 1838 		sock_release(sock2);
 1839 		goto out;
 1840 	}
 1841 
 1842 	newfile2 = sock_alloc_file(sock2, flags, NULL);
 1843 	if (IS_ERR(newfile2)) {
 1844 		err = PTR_ERR(newfile2);
 1845 		fput(newfile1);
 1846 		goto out;
 1847 	}
 1848 
 1849 	audit_fd_pair(fd1, fd2);
 1850 
 1851 	fd_install(fd1, newfile1);
 1852 	fd_install(fd2, newfile2);
 1853 	return 0;
 1854 
 1855 out:
 1856 	put_unused_fd(fd2);
 1857 	put_unused_fd(fd1);
 1858 	return err;
 1859 }
 1860 
 1861 SYSCALL_DEFINE4(socketpair, int, family, int, type, int, protocol,
 1862 		int __user *, usockvec)
 1863 {
 1864 	return __sys_socketpair(family, type, protocol, usockvec);
 1865 }
 1866 
 1867 int __sys_bind_socket(struct socket *sock, struct sockaddr_storage *address,
 1868 		      int addrlen)
 1869 {
 1870 	int err;
 1871 
 1872 	err = security_socket_bind(sock, (struct sockaddr *)address,
 1873 				   addrlen);
 1874 	if (!err)
 1875 		err = READ_ONCE(sock->ops)->bind(sock,
 1876 						 (struct sockaddr *)address,
 1877 						 addrlen);
 1878 	return err;
 1879 }
 1880 
 1881 /*
 1882  *	Bind a name to a socket. Nothing much to do here since it's
 1883  *	the protocol's responsibility to handle the local address.
 1884  *
 1885  *	We move the socket address to kernel space before we call
 1886  *	the protocol layer (having also checked the address is ok).
 1887  */
 1888 
 1889 int __sys_bind(int fd, struct sockaddr __user *umyaddr, int addrlen)
 1890 {
 1891 	struct socket *sock;
 1892 	struct sockaddr_storage address;
 1893 	CLASS(fd, f)(fd);
 1894 	int err;
 1895 
 1896 	if (fd_empty(f))
 1897 		return -EBADF;
 1898 	sock = sock_from_file(fd_file(f));
 1899 	if (unlikely(!sock))
 1900 		return -ENOTSOCK;
 1901 
 1902 	err = move_addr_to_kernel(umyaddr, addrlen, &address);
 1903 	if (unlikely(err))
 1904 		return err;
 1905 
 1906 	return __sys_bind_socket(sock, &address, addrlen);
 1907 }
 1908 
 1909 SYSCALL_DEFINE3(bind, int, fd, struct sockaddr __user *, umyaddr, int, addrlen)
 1910 {
 1911 	return __sys_bind(fd, umyaddr, addrlen);
 1912 }
 1913 
 1914 /*
 1915  *	Perform a listen. Basically, we allow the protocol to do anything
 1916  *	necessary for a listen, and if that works, we mark the socket as
 1917  *	ready for listening.
 1918  */
 1919 int __sys_listen_socket(struct socket *sock, int backlog)
 1920 {
 1921 	int somaxconn, err;
 1922 
 1923 	somaxconn = READ_ONCE(sock_net(sock->sk)->core.sysctl_somaxconn);
 1924 	if ((unsigned int)backlog > somaxconn)
 1925 		backlog = somaxconn;
 1926 
 1927 	err = security_socket_listen(sock, backlog);
 1928 	if (!err)
 1929 		err = READ_ONCE(sock->ops)->listen(sock, backlog);
 1930 	return err;
 1931 }
 1932 
 1933 int __sys_listen(int fd, int backlog)
 1934 {
 1935 	CLASS(fd, f)(fd);
 1936 	struct socket *sock;
 1937 
 1938 	if (fd_empty(f))
 1939 		return -EBADF;
 1940 	sock = sock_from_file(fd_file(f));
 1941 	if (unlikely(!sock))
 1942 		return -ENOTSOCK;
 1943 
 1944 	return __sys_listen_socket(sock, backlog);
 1945 }
 1946 
 1947 SYSCALL_DEFINE2(listen, int, fd, int, backlog)
 1948 {
 1949 	return __sys_listen(fd, backlog);
 1950 }
 1951 
 1952 struct file *do_accept(struct file *file, struct proto_accept_arg *arg,
 1953 		       struct sockaddr __user *upeer_sockaddr,
 1954 		       int __user *upeer_addrlen, int flags)
 1955 {
 1956 	struct socket *sock, *newsock;
 1957 	struct file *newfile;
 1958 	int err, len;
 1959 	struct sockaddr_storage address;
 1960 	const struct proto_ops *ops;
 1961 
 1962 	sock = sock_from_file(file);
 1963 	if (!sock)
 1964 		return ERR_PTR(-ENOTSOCK);
 1965 
 1966 	newsock = sock_alloc();
 1967 	if (!newsock)
 1968 		return ERR_PTR(-ENFILE);
 1969 	ops = READ_ONCE(sock->ops);
 1970 
 1971 	newsock->type = sock->type;
 1972 	newsock->ops = ops;
 1973 
 1974 	/*
 1975 	 * We don't need try_module_get here, as the listening socket (sock)
 1976 	 * has the protocol module (sock->ops->owner) held.
 1977 	 */
 1978 	__module_get(ops->owner);
 1979 
 1980 	newfile = sock_alloc_file(newsock, flags, sock->sk->sk_prot_creator->name);
 1981 	if (IS_ERR(newfile))
 1982 		return newfile;
 1983 
 1984 	err = security_socket_accept(sock, newsock);
 1985 	if (err)
 1986 		goto out_fd;
 1987 
 1988 	arg->flags |= sock->file->f_flags;
 1989 	err = ops->accept(sock, newsock, arg);
 1990 	if (err < 0)
 1991 		goto out_fd;
 1992 
 1993 	if (upeer_sockaddr) {
 1994 		len = ops->getname(newsock, (struct sockaddr *)&address, 2);
 1995 		if (len < 0) {
 1996 			err = -ECONNABORTED;
 1997 			goto out_fd;
 1998 		}
 1999 		err = move_addr_to_user(&address,
 2000 					len, upeer_sockaddr, upeer_addrlen);
 2001 		if (err < 0)
 2002 			goto out_fd;
 2003 	}
 2004 
 2005 	/* File flags are not inherited via accept() unlike another OSes. */
 2006 	return newfile;
 2007 out_fd:
 2008 	fput(newfile);
 2009 	return ERR_PTR(err);
 2010 }
 2011 
 2012 static int __sys_accept4_file(struct file *file, struct sockaddr __user *upeer_sockaddr,
 2013 			      int __user *upeer_addrlen, int flags)
 2014 {
 2015 	struct proto_accept_arg arg = { };
 2016 	struct file *newfile;
 2017 	int newfd;
 2018 
 2019 	if (flags & ~(SOCK_CLOEXEC | SOCK_NONBLOCK))
 2020 		return -EINVAL;
 2021 
 2022 	if (SOCK_NONBLOCK != O_NONBLOCK && (flags & SOCK_NONBLOCK))
 2023 		flags = (flags & ~SOCK_NONBLOCK) | O_NONBLOCK;
 2024 
 2025 	newfd = get_unused_fd_flags(flags);
 2026 	if (unlikely(newfd < 0))
 2027 		return newfd;
 2028 
 2029 	newfile = do_accept(file, &arg, upeer_sockaddr, upeer_addrlen,
 2030 			    flags);
 2031 	if (IS_ERR(newfile)) {
 2032 		put_unused_fd(newfd);
 2033 		return PTR_ERR(newfile);
 2034 	}
 2035 	fd_install(newfd, newfile);
 2036 	return newfd;
 2037 }
 2038 
 2039 /*
 2040  *	For accept, we attempt to create a new socket, set up the link
 2041  *	with the client, wake up the client, then return the new
 2042  *	connected fd. We collect the address of the connector in kernel
 2043  *	space and move it to user at the very end. This is unclean because
 2044  *	we open the socket then return an error.
 2045  *
 2046  *	1003.1g adds the ability to recvmsg() to query connection pending
 2047  *	status to recvmsg. We need to add that support in a way thats
 2048  *	clean when we restructure accept also.
 2049  */
 2050 
 2051 int __sys_accept4(int fd, struct sockaddr __user *upeer_sockaddr,
 2052 		  int __user *upeer_addrlen, int flags)
 2053 {
 2054 	CLASS(fd, f)(fd);
 2055 
 2056 	if (fd_empty(f))
 2057 		return -EBADF;
 2058 	return __sys_accept4_file(fd_file(f), upeer_sockaddr,
 2059 					 upeer_addrlen, flags);
 2060 }
 2061 
 2062 SYSCALL_DEFINE4(accept4, int, fd, struct sockaddr __user *, upeer_sockaddr,
 2063 		int __user *, upeer_addrlen, int, flags)
 2064 {
 2065 	return __sys_accept4(fd, upeer_sockaddr, upeer_addrlen, flags);
 2066 }
 2067 
 2068 SYSCALL_DEFINE3(accept, int, fd, struct sockaddr __user *, upeer_sockaddr,
 2069 		int __user *, upeer_addrlen)
 2070 {
 2071 	return __sys_accept4(fd, upeer_sockaddr, upeer_addrlen, 0);
 2072 }
 2073 
 2074 /*
 2075  *	Attempt to connect to a socket with the server address.  The address
 2076  *	is in user space so we verify it is OK and move it to kernel space.
 2077  *
 2078  *	For 1003.1g we need to add clean support for a bind to AF_UNSPEC to
 2079  *	break bindings
 2080  *
 2081  *	NOTE: 1003.1g draft 6.3 is broken with respect to AX.25/NetROM and
 2082  *	other SEQPACKET protocols that take time to connect() as it doesn't
 2083  *	include the -EINPROGRESS status for such sockets.
 2084  */
 2085 
 2086 int __sys_connect_file(struct file *file, struct sockaddr_storage *address,
 2087 		       int addrlen, int file_flags)
 2088 {
 2089 	struct socket *sock;
 2090 	int err;
 2091 
 2092 	sock = sock_from_file(file);
 2093 	if (!sock) {
 2094 		err = -ENOTSOCK;
 2095 		goto out;
 2096 	}
 2097 
 2098 	err =
 2099 	    security_socket_connect(sock, (struct sockaddr *)address, addrlen);
 2100 	if (err)
 2101 		goto out;
 2102 
 2103 	err = READ_ONCE(sock->ops)->connect(sock, (struct sockaddr *)address,
 2104 				addrlen, sock->file->f_flags | file_flags);
 2105 out:
 2106 	return err;
 2107 }
 2108 
 2109 int __sys_connect(int fd, struct sockaddr __user *uservaddr, int addrlen)
 2110 {
 2111 	struct sockaddr_storage address;
 2112 	CLASS(fd, f)(fd);
 2113 	int ret;
 2114 
 2115 	if (fd_empty(f))
 2116 		return -EBADF;
 2117 
 2118 	ret = move_addr_to_kernel(uservaddr, addrlen, &address);
 2119 	if (ret)
 2120 		return ret;
 2121 
 2122 	return __sys_connect_file(fd_file(f), &address, addrlen, 0);
 2123 }
 2124 
 2125 SYSCALL_DEFINE3(connect, int, fd, struct sockaddr __user *, uservaddr,
 2126 		int, addrlen)
 2127 {
 2128 	return __sys_connect(fd, uservaddr, addrlen);
 2129 }
 2130 
 2131 /*
 2132  *	Get the local address ('name') of a socket object. Move the obtained
 2133  *	name to user space.
 2134  */
 2135 
 2136 int __sys_getsockname(int fd, struct sockaddr __user *usockaddr,
 2137 		      int __user *usockaddr_len)
 2138 {
 2139 	struct socket *sock;
 2140 	struct sockaddr_storage address;
 2141 	CLASS(fd, f)(fd);
 2142 	int err;
 2143 
 2144 	if (fd_empty(f))
 2145 		return -EBADF;
 2146 	sock = sock_from_file(fd_file(f));
 2147 	if (unlikely(!sock))
 2148 		return -ENOTSOCK;
 2149 
 2150 	err = security_socket_getsockname(sock);
 2151 	if (err)
 2152 		return err;
 2153 
 2154 	err = READ_ONCE(sock->ops)->getname(sock, (struct sockaddr *)&address, 0);
 2155 	if (err < 0)
 2156 		return err;
 2157 
 2158 	/* "err" is actually length in this case */
 2159 	return move_addr_to_user(&address, err, usockaddr, usockaddr_len);
 2160 }
 2161 
 2162 SYSCALL_DEFINE3(getsockname, int, fd, struct sockaddr __user *, usockaddr,
 2163 		int __user *, usockaddr_len)
 2164 {
 2165 	return __sys_getsockname(fd, usockaddr, usockaddr_len);
 2166 }
 2167 
 2168 /*
 2169  *	Get the remote address ('name') of a socket object. Move the obtained
 2170  *	name to user space.
 2171  */
 2172 
 2173 int __sys_getpeername(int fd, struct sockaddr __user *usockaddr,
 2174 		      int __user *usockaddr_len)
 2175 {
 2176 	struct socket *sock;
 2177 	struct sockaddr_storage address;
 2178 	CLASS(fd, f)(fd);
 2179 	int err;
 2180 
 2181 	if (fd_empty(f))
 2182 		return -EBADF;
 2183 	sock = sock_from_file(fd_file(f));
 2184 	if (unlikely(!sock))
 2185 		return -ENOTSOCK;
 2186 
 2187 	err = security_socket_getpeername(sock);
 2188 	if (err)
 2189 		return err;
 2190 
 2191 	err = READ_ONCE(sock->ops)->getname(sock, (struct sockaddr *)&address, 1);
 2192 	if (err < 0)
 2193 		return err;
 2194 
 2195 	/* "err" is actually length in this case */
 2196 	return move_addr_to_user(&address, err, usockaddr, usockaddr_len);
 2197 }
 2198 
 2199 SYSCALL_DEFINE3(getpeername, int, fd, struct sockaddr __user *, usockaddr,
 2200 		int __user *, usockaddr_len)
 2201 {
 2202 	return __sys_getpeername(fd, usockaddr, usockaddr_len);
 2203 }
 2204 
 2205 /*
 2206  *	Send a datagram to a given address. We move the address into kernel
 2207  *	space and check the user space data area is readable before invoking
 2208  *	the protocol.
 2209  */
 2210 int __sys_sendto(int fd, void __user *buff, size_t len, unsigned int flags,
 2211 		 struct sockaddr __user *addr,  int addr_len)
 2212 {
 2213 	struct socket *sock;
 2214 	struct sockaddr_storage address;
 2215 	int err;
 2216 	struct msghdr msg;
 2217 
 2218 	err = import_ubuf(ITER_SOURCE, buff, len, &msg.msg_iter);
 2219 	if (unlikely(err))
 2220 		return err;
 2221 
 2222 	CLASS(fd, f)(fd);
 2223 	if (fd_empty(f))
 2224 		return -EBADF;
 2225 	sock = sock_from_file(fd_file(f));
 2226 	if (unlikely(!sock))
 2227 		return -ENOTSOCK;
 2228 
 2229 	msg.msg_name = NULL;
 2230 	msg.msg_control = NULL;
 2231 	msg.msg_controllen = 0;
 2232 	msg.msg_namelen = 0;
 2233 	msg.msg_ubuf = NULL;
 2234 	if (addr) {
 2235 		err = move_addr_to_kernel(addr, addr_len, &address);
 2236 		if (err < 0)
 2237 			return err;
 2238 		msg.msg_name = (struct sockaddr *)&address;
 2239 		msg.msg_namelen = addr_len;
 2240 	}
 2241 	flags &= ~MSG_INTERNAL_SENDMSG_FLAGS;
 2242 	if (sock->file->f_flags & O_NONBLOCK)
 2243 		flags |= MSG_DONTWAIT;
 2244 	msg.msg_flags = flags;
 2245 	return __sock_sendmsg(sock, &msg);
 2246 }
 2247 
 2248 SYSCALL_DEFINE6(sendto, int, fd, void __user *, buff, size_t, len,
 2249 		unsigned int, flags, struct sockaddr __user *, addr,
 2250 		int, addr_len)
 2251 {
 2252 	return __sys_sendto(fd, buff, len, flags, addr, addr_len);
 2253 }
 2254 
 2255 /*
 2256  *	Send a datagram down a socket.
 2257  */
 2258 
 2259 SYSCALL_DEFINE4(send, int, fd, void __user *, buff, size_t, len,
 2260 		unsigned int, flags)
 2261 {
 2262 	return __sys_sendto(fd, buff, len, flags, NULL, 0);
 2263 }
 2264 
 2265 /*
 2266  *	Receive a frame from the socket and optionally record the address of the
 2267  *	sender. We verify the buffers are writable and if needed move the
 2268  *	sender address from kernel to user space.
 2269  */
 2270 int __sys_recvfrom(int fd, void __user *ubuf, size_t size, unsigned int flags,
 2271 		   struct sockaddr __user *addr, int __user *addr_len)
 2272 {
 2273 	struct sockaddr_storage address;
 2274 	struct msghdr msg = {
 2275 		/* Save some cycles and don't copy the address if not needed */
 2276 		.msg_name = addr ? (struct sockaddr *)&address : NULL,
 2277 	};
 2278 	struct socket *sock;
 2279 	int err, err2;
 2280 
 2281 	err = import_ubuf(ITER_DEST, ubuf, size, &msg.msg_iter);
 2282 	if (unlikely(err))
 2283 		return err;
 2284 
 2285 	CLASS(fd, f)(fd);
 2286 
 2287 	if (fd_empty(f))
 2288 		return -EBADF;
 2289 	sock = sock_from_file(fd_file(f));
 2290 	if (unlikely(!sock))
 2291 		return -ENOTSOCK;
 2292 
 2293 	if (sock->file->f_flags & O_NONBLOCK)
 2294 		flags |= MSG_DONTWAIT;
 2295 	err = sock_recvmsg(sock, &msg, flags);
 2296 
 2297 	if (err >= 0 && addr != NULL) {
 2298 		err2 = move_addr_to_user(&address,
 2299 					 msg.msg_namelen, addr, addr_len);
 2300 		if (err2 < 0)
 2301 			err = err2;
 2302 	}
 2303 	return err;
 2304 }
 2305 
 2306 SYSCALL_DEFINE6(recvfrom, int, fd, void __user *, ubuf, size_t, size,
 2307 		unsigned int, flags, struct sockaddr __user *, addr,
 2308 		int __user *, addr_len)
 2309 {
 2310 	return __sys_recvfrom(fd, ubuf, size, flags, addr, addr_len);
 2311 }
 2312 
 2313 /*
 2314  *	Receive a datagram from a socket.
 2315  */
 2316 
 2317 SYSCALL_DEFINE4(recv, int, fd, void __user *, ubuf, size_t, size,
 2318 		unsigned int, flags)
 2319 {
 2320 	return __sys_recvfrom(fd, ubuf, size, flags, NULL, NULL);
 2321 }
 2322 
 2323 static bool sock_use_custom_sol_socket(const struct socket *sock)
 2324 {
 2325 	return test_bit(SOCK_CUSTOM_SOCKOPT, &sock->flags);
 2326 }
 2327 
 2328 int do_sock_setsockopt(struct socket *sock, bool compat, int level,
 2329 		       int optname, sockptr_t optval, int optlen)
 2330 {
 2331 	const struct proto_ops *ops;
 2332 	char *kernel_optval = NULL;
 2333 	int err;
 2334 
 2335 	if (optlen < 0)
 2336 		return -EINVAL;
 2337 
 2338 	err = security_socket_setsockopt(sock, level, optname);
 2339 	if (err)
 2340 		goto out_put;
 2341 
 2342 	if (!compat)
 2343 		err = BPF_CGROUP_RUN_PROG_SETSOCKOPT(sock->sk, &level, &optname,
 2344 						     optval, &optlen,
 2345 						     &kernel_optval);
 2346 	if (err < 0)
 2347 		goto out_put;
 2348 	if (err > 0) {
 2349 		err = 0;
 2350 		goto out_put;
 2351 	}
 2352 
 2353 	if (kernel_optval)
 2354 		optval = KERNEL_SOCKPTR(kernel_optval);
 2355 	ops = READ_ONCE(sock->ops);
 2356 	if (level == SOL_SOCKET && !sock_use_custom_sol_socket(sock))
 2357 		err = sock_setsockopt(sock, level, optname, optval, optlen);
 2358 	else if (unlikely(!ops->setsockopt))
 2359 		err = -EOPNOTSUPP;
 2360 	else
 2361 		err = ops->setsockopt(sock, level, optname, optval,
 2362 					    optlen);
 2363 	kfree(kernel_optval);
 2364 out_put:
 2365 	return err;
 2366 }
 2367 EXPORT_SYMBOL(do_sock_setsockopt);
 2368 
 2369 /* Set a socket option. Because we don't know the option lengths we have
 2370  * to pass the user mode parameter for the protocols to sort out.
 2371  */
 2372 int __sys_setsockopt(int fd, int level, int optname, char __user *user_optval,
 2373 		     int optlen)
 2374 {
 2375 	sockptr_t optval = USER_SOCKPTR(user_optval);
 2376 	bool compat = in_compat_syscall();
 2377 	struct socket *sock;
 2378 	CLASS(fd, f)(fd);
 2379 
 2380 	if (fd_empty(f))
 2381 		return -EBADF;
 2382 	sock = sock_from_file(fd_file(f));
 2383 	if (unlikely(!sock))
 2384 		return -ENOTSOCK;
 2385 
 2386 	return do_sock_setsockopt(sock, compat, level, optname, optval, optlen);
 2387 }
 2388 
 2389 SYSCALL_DEFINE5(setsockopt, int, fd, int, level, int, optname,
 2390 		char __user *, optval, int, optlen)
 2391 {
 2392 	return __sys_setsockopt(fd, level, optname, optval, optlen);
 2393 }
 2394 
 2395 INDIRECT_CALLABLE_DECLARE(bool tcp_bpf_bypass_getsockopt(int level,
 2396 							 int optname));
 2397 
 2398 int do_sock_getsockopt(struct socket *sock, bool compat, int level,
 2399 		       int optname, sockptr_t optval, sockptr_t optlen)
 2400 {
 2401 	int max_optlen __maybe_unused = 0;
 2402 	const struct proto_ops *ops;
 2403 	int err;
 2404 
 2405 	err = security_socket_getsockopt(sock, level, optname);
 2406 	if (err)
 2407 		return err;
 2408 
 2409 	if (!compat)
 2410 		copy_from_sockptr(&max_optlen, optlen, sizeof(int));
 2411 
 2412 	ops = READ_ONCE(sock->ops);
 2413 	if (level == SOL_SOCKET) {
 2414 		err = sk_getsockopt(sock->sk, level, optname, optval, optlen);
 2415 	} else if (unlikely(!ops->getsockopt)) {
 2416 		err = -EOPNOTSUPP;
 2417 	} else {
 2418 		if (WARN_ONCE(optval.is_kernel || optlen.is_kernel,
 2419 			      "Invalid argument type"))
 2420 			return -EOPNOTSUPP;
 2421 
 2422 		err = ops->getsockopt(sock, level, optname, optval.user,
 2423 				      optlen.user);
 2424 	}
 2425 
 2426 	if (!compat)
 2427 		err = BPF_CGROUP_RUN_PROG_GETSOCKOPT(sock->sk, level, optname,
 2428 						     optval, optlen, max_optlen,
 2429 						     err);
 2430 
 2431 	return err;
 2432 }
 2433 EXPORT_SYMBOL(do_sock_getsockopt);
 2434 
 2435 /*
 2436  *	Get a socket option. Because we don't know the option lengths we have
 2437  *	to pass a user mode parameter for the protocols to sort out.
 2438  */
 2439 int __sys_getsockopt(int fd, int level, int optname, char __user *optval,
 2440 		int __user *optlen)
 2441 {
 2442 	struct socket *sock;
 2443 	CLASS(fd, f)(fd);
 2444 
 2445 	if (fd_empty(f))
 2446 		return -EBADF;
 2447 	sock = sock_from_file(fd_file(f));
 2448 	if (unlikely(!sock))
 2449 		return -ENOTSOCK;
 2450 
 2451 	return do_sock_getsockopt(sock, in_compat_syscall(), level, optname,
 2452 				 USER_SOCKPTR(optval), USER_SOCKPTR(optlen));
 2453 }
 2454 
 2455 SYSCALL_DEFINE5(getsockopt, int, fd, int, level, int, optname,
 2456 		char __user *, optval, int __user *, optlen)
 2457 {
 2458 	return __sys_getsockopt(fd, level, optname, optval, optlen);
 2459 }
 2460 
 2461 /*
 2462  *	Shutdown a socket.
 2463  */
 2464 
 2465 int __sys_shutdown_sock(struct socket *sock, int how)
 2466 {
 2467 	int err;
 2468 
 2469 	err = security_socket_shutdown(sock, how);
 2470 	if (!err)
 2471 		err = READ_ONCE(sock->ops)->shutdown(sock, how);
 2472 
 2473 	return err;
 2474 }
 2475 
 2476 int __sys_shutdown(int fd, int how)
 2477 {
 2478 	struct socket *sock;
 2479 	CLASS(fd, f)(fd);
 2480 
 2481 	if (fd_empty(f))
 2482 		return -EBADF;
 2483 	sock = sock_from_file(fd_file(f));
 2484 	if (unlikely(!sock))
 2485 		return -ENOTSOCK;
 2486 
 2487 	return __sys_shutdown_sock(sock, how);
 2488 }
 2489 
 2490 SYSCALL_DEFINE2(shutdown, int, fd, int, how)
 2491 {
 2492 	return __sys_shutdown(fd, how);
 2493 }
 2494 
 2495 /* A couple of helpful macros for getting the address of the 32/64 bit
 2496  * fields which are the same type (int / unsigned) on our platforms.
 2497  */
 2498 #define COMPAT_MSG(msg, member)	((MSG_CMSG_COMPAT & flags) ? &msg##_compat->member : &msg->member)
 2499 #define COMPAT_NAMELEN(msg)	COMPAT_MSG(msg, msg_namelen)
 2500 #define COMPAT_FLAGS(msg)	COMPAT_MSG(msg, msg_flags)
 2501 
 2502 struct used_address {
 2503 	struct sockaddr_storage name;
 2504 	unsigned int name_len;
 2505 };
 2506 
 2507 int __copy_msghdr(struct msghdr *kmsg,
 2508 		  struct user_msghdr *msg,
 2509 		  struct sockaddr __user **save_addr)
 2510 {
 2511 	ssize_t err;
 2512 
 2513 	kmsg->msg_control_is_user = true;
 2514 	kmsg->msg_get_inq = 0;
 2515 	kmsg->msg_control_user = msg->msg_control;
 2516 	kmsg->msg_controllen = msg->msg_controllen;
 2517 	kmsg->msg_flags = msg->msg_flags;
 2518 
 2519 	kmsg->msg_namelen = msg->msg_namelen;
 2520 	if (!msg->msg_name)
 2521 		kmsg->msg_namelen = 0;
 2522 
 2523 	if (kmsg->msg_namelen < 0)
 2524 		return -EINVAL;
 2525 
 2526 	if (kmsg->msg_namelen > sizeof(struct sockaddr_storage))
 2527 		kmsg->msg_namelen = sizeof(struct sockaddr_storage);
 2528 
 2529 	if (save_addr)
 2530 		*save_addr = msg->msg_name;
 2531 
 2532 	if (msg->msg_name && kmsg->msg_namelen) {
 2533 		if (!save_addr) {
 2534 			err = move_addr_to_kernel(msg->msg_name,
 2535 						  kmsg->msg_namelen,
 2536 						  kmsg->msg_name);
 2537 			if (err < 0)
 2538 				return err;
 2539 		}
 2540 	} else {
 2541 		kmsg->msg_name = NULL;
 2542 		kmsg->msg_namelen = 0;
 2543 	}
 2544 
 2545 	if (msg->msg_iovlen > UIO_MAXIOV)
 2546 		return -EMSGSIZE;
 2547 
 2548 	kmsg->msg_iocb = NULL;
 2549 	kmsg->msg_ubuf = NULL;
 2550 	return 0;
 2551 }
 2552 
 2553 static int copy_msghdr_from_user(struct msghdr *kmsg,
 2554 				 struct user_msghdr __user *umsg,
 2555 				 struct sockaddr __user **save_addr,
 2556 				 struct iovec **iov)
 2557 {
 2558 	struct user_msghdr msg;
 2559 	ssize_t err;
 2560 
 2561 	if (copy_from_user(&msg, umsg, sizeof(*umsg)))
 2562 		return -EFAULT;
 2563 
 2564 	err = __copy_msghdr(kmsg, &msg, save_addr);
 2565 	if (err)
 2566 		return err;
 2567 
 2568 	err = import_iovec(save_addr ? ITER_DEST : ITER_SOURCE,
 2569 			    msg.msg_iov, msg.msg_iovlen,
 2570 			    UIO_FASTIOV, iov, &kmsg->msg_iter);
 2571 	return err < 0 ? err : 0;
 2572 }
 2573 
 2574 static int ____sys_sendmsg(struct socket *sock, struct msghdr *msg_sys,
 2575 			   unsigned int flags, struct used_address *used_address,
 2576 			   unsigned int allowed_msghdr_flags)
 2577 {
 2578 	unsigned char ctl[sizeof(struct cmsghdr) + 20]
 2579 				__aligned(sizeof(__kernel_size_t));
 2580 	/* 20 is size of ipv6_pktinfo */
 2581 	unsigned char *ctl_buf = ctl;
 2582 	int ctl_len;
 2583 	ssize_t err;
 2584 
 2585 	err = -ENOBUFS;
 2586 
 2587 	if (msg_sys->msg_controllen > INT_MAX)
 2588 		goto out;
 2589 	flags |= (msg_sys->msg_flags & allowed_msghdr_flags);
 2590 	ctl_len = msg_sys->msg_controllen;
 2591 	if ((MSG_CMSG_COMPAT & flags) && ctl_len) {
 2592 		err =
 2593 		    cmsghdr_from_user_compat_to_kern(msg_sys, sock->sk, ctl,
 2594 						     sizeof(ctl));
 2595 		if (err)
 2596 			goto out;
 2597 		ctl_buf = msg_sys->msg_control;
 2598 		ctl_len = msg_sys->msg_controllen;
 2599 	} else if (ctl_len) {
 2600 		BUILD_BUG_ON(sizeof(struct cmsghdr) !=
 2601 			     CMSG_ALIGN(sizeof(struct cmsghdr)));
 2602 		if (ctl_len > sizeof(ctl)) {
 2603 			ctl_buf = sock_kmalloc(sock->sk, ctl_len, GFP_KERNEL);
 2604 			if (ctl_buf == NULL)
 2605 				goto out;
 2606 		}
 2607 		err = -EFAULT;
 2608 		if (copy_from_user(ctl_buf, msg_sys->msg_control_user, ctl_len))
 2609 			goto out_freectl;
 2610 		msg_sys->msg_control = ctl_buf;
 2611 		msg_sys->msg_control_is_user = false;
 2612 	}
 2613 	flags &= ~MSG_INTERNAL_SENDMSG_FLAGS;
 2614 	msg_sys->msg_flags = flags;
 2615 
 2616 	if (sock->file->f_flags & O_NONBLOCK)
 2617 		msg_sys->msg_flags |= MSG_DONTWAIT;
 2618 	/*
 2619 	 * If this is sendmmsg() and current destination address is same as
 2620 	 * previously succeeded address, omit asking LSM's decision.
 2621 	 * used_address->name_len is initialized to UINT_MAX so that the first
 2622 	 * destination address never matches.
 2623 	 */
 2624 	if (used_address && msg_sys->msg_name &&
 2625 	    used_address->name_len == msg_sys->msg_namelen &&
 2626 	    !memcmp(&used_address->name, msg_sys->msg_name,
 2627 		    used_address->name_len)) {
 2628 		err = sock_sendmsg_nosec(sock, msg_sys);
 2629 		goto out_freectl;
 2630 	}
 2631 	err = __sock_sendmsg(sock, msg_sys);
 2632 	/*
 2633 	 * If this is sendmmsg() and sending to current destination address was
 2634 	 * successful, remember it.
 2635 	 */
 2636 	if (used_address && err >= 0) {
 2637 		used_address->name_len = msg_sys->msg_namelen;
 2638 		if (msg_sys->msg_name)
 2639 			memcpy(&used_address->name, msg_sys->msg_name,
 2640 			       used_address->name_len);
 2641 	}
 2642 
 2643 out_freectl:
 2644 	if (ctl_buf != ctl)
 2645 		sock_kfree_s(sock->sk, ctl_buf, ctl_len);
 2646 out:
 2647 	return err;
 2648 }
 2649 
 2650 static int sendmsg_copy_msghdr(struct msghdr *msg,
 2651 			       struct user_msghdr __user *umsg, unsigned flags,
 2652 			       struct iovec **iov)
 2653 {
 2654 	int err;
 2655 
 2656 	if (flags & MSG_CMSG_COMPAT) {
 2657 		struct compat_msghdr __user *msg_compat;
 2658 
 2659 		msg_compat = (struct compat_msghdr __user *) umsg;
 2660 		err = get_compat_msghdr(msg, msg_compat, NULL, iov);
 2661 	} else {
 2662 		err = copy_msghdr_from_user(msg, umsg, NULL, iov);
 2663 	}
 2664 	if (err < 0)
 2665 		return err;
 2666 
 2667 	return 0;
 2668 }
 2669 
 2670 static int ___sys_sendmsg(struct socket *sock, struct user_msghdr __user *msg,
 2671 			 struct msghdr *msg_sys, unsigned int flags,
 2672 			 struct used_address *used_address,
 2673 			 unsigned int allowed_msghdr_flags)
 2674 {
 2675 	struct sockaddr_storage address;
 2676 	struct iovec iovstack[UIO_FASTIOV], *iov = iovstack;
 2677 	ssize_t err;
 2678 
 2679 	msg_sys->msg_name = &address;
 2680 
 2681 	err = sendmsg_copy_msghdr(msg_sys, msg, flags, &iov);
 2682 	if (err < 0)
 2683 		return err;
 2684 
 2685 	err = ____sys_sendmsg(sock, msg_sys, flags, used_address,
 2686 				allowed_msghdr_flags);
 2687 	kfree(iov);
 2688 	return err;
 2689 }
 2690 
 2691 /*
 2692  *	BSD sendmsg interface
 2693  */
 2694 long __sys_sendmsg_sock(struct socket *sock, struct msghdr *msg,
 2695 			unsigned int flags)
 2696 {
 2697 	return ____sys_sendmsg(sock, msg, flags, NULL, 0);
 2698 }
 2699 
 2700 long __sys_sendmsg(int fd, struct user_msghdr __user *msg, unsigned int flags,
 2701 		   bool forbid_cmsg_compat)
 2702 {
 2703 	struct msghdr msg_sys;
 2704 	struct socket *sock;
 2705 
 2706 	if (forbid_cmsg_compat && (flags & MSG_CMSG_COMPAT))
 2707 		return -EINVAL;
 2708 
 2709 	CLASS(fd, f)(fd);
 2710 
 2711 	if (fd_empty(f))
 2712 		return -EBADF;
 2713 	sock = sock_from_file(fd_file(f));
 2714 	if (unlikely(!sock))
 2715 		return -ENOTSOCK;
 2716 
 2717 	return ___sys_sendmsg(sock, msg, &msg_sys, flags, NULL, 0);
 2718 }
 2719 
 2720 SYSCALL_DEFINE3(sendmsg, int, fd, struct user_msghdr __user *, msg, unsigned int, flags)
 2721 {
 2722 	return __sys_sendmsg(fd, msg, flags, true);
 2723 }
 2724 
 2725 /*
 2726  *	Linux sendmmsg interface
 2727  */
 2728 
 2729 int __sys_sendmmsg(int fd, struct mmsghdr __user *mmsg, unsigned int vlen,
 2730 		   unsigned int flags, bool forbid_cmsg_compat)
 2731 {
 2732 	int err, datagrams;
 2733 	struct socket *sock;
 2734 	struct mmsghdr __user *entry;
 2735 	struct compat_mmsghdr __user *compat_entry;
 2736 	struct msghdr msg_sys;
 2737 	struct used_address used_address;
 2738 	unsigned int oflags = flags;
 2739 
 2740 	if (forbid_cmsg_compat && (flags & MSG_CMSG_COMPAT))
 2741 		return -EINVAL;
 2742 
 2743 	if (vlen > UIO_MAXIOV)
 2744 		vlen = UIO_MAXIOV;
 2745 
 2746 	datagrams = 0;
 2747 
 2748 	CLASS(fd, f)(fd);
 2749 
 2750 	if (fd_empty(f))
 2751 		return -EBADF;
 2752 	sock = sock_from_file(fd_file(f));
 2753 	if (unlikely(!sock))
 2754 		return -ENOTSOCK;
 2755 
 2756 	used_address.name_len = UINT_MAX;
 2757 	entry = mmsg;
 2758 	compat_entry = (struct compat_mmsghdr __user *)mmsg;
 2759 	err = 0;
 2760 	flags |= MSG_BATCH;
 2761 
 2762 	while (datagrams < vlen) {
 2763 		if (datagrams == vlen - 1)
 2764 			flags = oflags;
 2765 
 2766 		if (MSG_CMSG_COMPAT & flags) {
 2767 			err = ___sys_sendmsg(sock, (struct user_msghdr __user *)compat_entry,
 2768 					     &msg_sys, flags, &used_address, MSG_EOR);
 2769 			if (err < 0)
 2770 				break;
 2771 			err = __put_user(err, &compat_entry->msg_len);
 2772 			++compat_entry;
 2773 		} else {
 2774 			err = ___sys_sendmsg(sock,
 2775 					     (struct user_msghdr __user *)entry,
 2776 					     &msg_sys, flags, &used_address, MSG_EOR);
 2777 			if (err < 0)
 2778 				break;
 2779 			err = put_user(err, &entry->msg_len);
 2780 			++entry;
 2781 		}
 2782 
 2783 		if (err)
 2784 			break;
 2785 		++datagrams;
 2786 		if (msg_data_left(&msg_sys))
 2787 			break;
 2788 		cond_resched();
 2789 	}
 2790 
 2791 	/* We only return an error if no datagrams were able to be sent */
 2792 	if (datagrams != 0)
 2793 		return datagrams;
 2794 
 2795 	return err;
 2796 }
 2797 
 2798 SYSCALL_DEFINE4(sendmmsg, int, fd, struct mmsghdr __user *, mmsg,
 2799 		unsigned int, vlen, unsigned int, flags)
 2800 {
 2801 	return __sys_sendmmsg(fd, mmsg, vlen, flags, true);
 2802 }
 2803 
 2804 static int recvmsg_copy_msghdr(struct msghdr *msg,
 2805 			       struct user_msghdr __user *umsg, unsigned flags,
 2806 			       struct sockaddr __user **uaddr,
 2807 			       struct iovec **iov)
 2808 {
 2809 	ssize_t err;
 2810 
 2811 	if (MSG_CMSG_COMPAT & flags) {
 2812 		struct compat_msghdr __user *msg_compat;
 2813 
 2814 		msg_compat = (struct compat_msghdr __user *) umsg;
 2815 		err = get_compat_msghdr(msg, msg_compat, uaddr, iov);
 2816 	} else {
 2817 		err = copy_msghdr_from_user(msg, umsg, uaddr, iov);
 2818 	}
 2819 	if (err < 0)
 2820 		return err;
 2821 
 2822 	return 0;
 2823 }
 2824 
 2825 static int ____sys_recvmsg(struct socket *sock, struct msghdr *msg_sys,
 2826 			   struct user_msghdr __user *msg,
 2827 			   struct sockaddr __user *uaddr,
 2828 			   unsigned int flags, int nosec)
 2829 {
 2830 	struct compat_msghdr __user *msg_compat =
 2831 					(struct compat_msghdr __user *) msg;
 2832 	int __user *uaddr_len = COMPAT_NAMELEN(msg);
 2833 	struct sockaddr_storage addr;
 2834 	unsigned long cmsg_ptr;
 2835 	int len;
 2836 	ssize_t err;
 2837 
 2838 	msg_sys->msg_name = &addr;
 2839 	cmsg_ptr = (unsigned long)msg_sys->msg_control;
 2840 	msg_sys->msg_flags = flags & (MSG_CMSG_CLOEXEC|MSG_CMSG_COMPAT);
 2841 
 2842 	/* We assume all kernel code knows the size of sockaddr_storage */
 2843 	msg_sys->msg_namelen = 0;
 2844 
 2845 	if (sock->file->f_flags & O_NONBLOCK)
 2846 		flags |= MSG_DONTWAIT;
 2847 
 2848 	if (unlikely(nosec))
 2849 		err = sock_recvmsg_nosec(sock, msg_sys, flags);
 2850 	else
 2851 		err = sock_recvmsg(sock, msg_sys, flags);
 2852 
 2853 	if (err < 0)
 2854 		goto out;
 2855 	len = err;
 2856 
 2857 	if (uaddr != NULL) {
 2858 		err = move_addr_to_user(&addr,
 2859 					msg_sys->msg_namelen, uaddr,
 2860 					uaddr_len);
 2861 		if (err < 0)
 2862 			goto out;
 2863 	}
 2864 	err = __put_user((msg_sys->msg_flags & ~MSG_CMSG_COMPAT),
 2865 			 COMPAT_FLAGS(msg));
 2866 	if (err)
 2867 		goto out;
 2868 	if (MSG_CMSG_COMPAT & flags)
 2869 		err = __put_user((unsigned long)msg_sys->msg_control - cmsg_ptr,
 2870 				 &msg_compat->msg_controllen);
 2871 	else
 2872 		err = __put_user((unsigned long)msg_sys->msg_control - cmsg_ptr,
 2873 				 &msg->msg_controllen);
 2874 	if (err)
 2875 		goto out;
 2876 	err = len;
 2877 out:
 2878 	return err;
 2879 }
 2880 
 2881 static int ___sys_recvmsg(struct socket *sock, struct user_msghdr __user *msg,
 2882 			 struct msghdr *msg_sys, unsigned int flags, int nosec)
 2883 {
 2884 	struct iovec iovstack[UIO_FASTIOV], *iov = iovstack;
 2885 	/* user mode address pointers */
 2886 	struct sockaddr __user *uaddr;
 2887 	ssize_t err;
 2888 
 2889 	err = recvmsg_copy_msghdr(msg_sys, msg, flags, &uaddr, &iov);
 2890 	if (err < 0)
 2891 		return err;
 2892 
 2893 	err = ____sys_recvmsg(sock, msg_sys, msg, uaddr, flags, nosec);
 2894 	kfree(iov);
 2895 	return err;
 2896 }
 2897 
 2898 /*
 2899  *	BSD recvmsg interface
 2900  */
 2901 
 2902 long __sys_recvmsg_sock(struct socket *sock, struct msghdr *msg,
 2903 			struct user_msghdr __user *umsg,
 2904 			struct sockaddr __user *uaddr, unsigned int flags)
 2905 {
 2906 	return ____sys_recvmsg(sock, msg, umsg, uaddr, flags, 0);
 2907 }
 2908 
 2909 long __sys_recvmsg(int fd, struct user_msghdr __user *msg, unsigned int flags,
 2910 		   bool forbid_cmsg_compat)
 2911 {
 2912 	struct msghdr msg_sys;
 2913 	struct socket *sock;
 2914 
 2915 	if (forbid_cmsg_compat && (flags & MSG_CMSG_COMPAT))
 2916 		return -EINVAL;
 2917 
 2918 	CLASS(fd, f)(fd);
 2919 
 2920 	if (fd_empty(f))
 2921 		return -EBADF;
 2922 	sock = sock_from_file(fd_file(f));
 2923 	if (unlikely(!sock))
 2924 		return -ENOTSOCK;
 2925 
 2926 	return ___sys_recvmsg(sock, msg, &msg_sys, flags, 0);
 2927 }
 2928 
 2929 SYSCALL_DEFINE3(recvmsg, int, fd, struct user_msghdr __user *, msg,
 2930 		unsigned int, flags)
 2931 {
 2932 	return __sys_recvmsg(fd, msg, flags, true);
 2933 }
 2934 
 2935 /*
 2936  *     Linux recvmmsg interface
 2937  */
 2938 
 2939 static int do_recvmmsg(int fd, struct mmsghdr __user *mmsg,
 2940 			  unsigned int vlen, unsigned int flags,
 2941 			  struct timespec64 *timeout)
 2942 {
 2943 	int err = 0, datagrams;
 2944 	struct socket *sock;
 2945 	struct mmsghdr __user *entry;
 2946 	struct compat_mmsghdr __user *compat_entry;
 2947 	struct msghdr msg_sys;
 2948 	struct timespec64 end_time;
 2949 	struct timespec64 timeout64;
 2950 
 2951 	if (timeout &&
 2952 	    poll_select_set_timeout(&end_time, timeout->tv_sec,
 2953 				    timeout->tv_nsec))
 2954 		return -EINVAL;
 2955 
 2956 	datagrams = 0;
 2957 
 2958 	CLASS(fd, f)(fd);
 2959 
 2960 	if (fd_empty(f))
 2961 		return -EBADF;
 2962 	sock = sock_from_file(fd_file(f));
 2963 	if (unlikely(!sock))
 2964 		return -ENOTSOCK;
 2965 
 2966 	if (likely(!(flags & MSG_ERRQUEUE))) {
 2967 		err = sock_error(sock->sk);
 2968 		if (err)
 2969 			return err;
 2970 	}
 2971 
 2972 	entry = mmsg;
 2973 	compat_entry = (struct compat_mmsghdr __user *)mmsg;
 2974 
 2975 	while (datagrams < vlen) {
 2976 		/*
 2977 		 * No need to ask LSM for more than the first datagram.
 2978 		 */
 2979 		if (MSG_CMSG_COMPAT & flags) {
 2980 			err = ___sys_recvmsg(sock, (struct user_msghdr __user *)compat_entry,
 2981 					     &msg_sys, flags & ~MSG_WAITFORONE,
 2982 					     datagrams);
 2983 			if (err < 0)
 2984 				break;
 2985 			err = __put_user(err, &compat_entry->msg_len);
 2986 			++compat_entry;
 2987 		} else {
 2988 			err = ___sys_recvmsg(sock,
 2989 					     (struct user_msghdr __user *)entry,
 2990 					     &msg_sys, flags & ~MSG_WAITFORONE,
 2991 					     datagrams);
 2992 			if (err < 0)
 2993 				break;
 2994 			err = put_user(err, &entry->msg_len);
 2995 			++entry;
 2996 		}
 2997 
 2998 		if (err)
 2999 			break;
 3000 		++datagrams;
 3001 
 3002 		/* MSG_WAITFORONE turns on MSG_DONTWAIT after one packet */
 3003 		if (flags & MSG_WAITFORONE)
 3004 			flags |= MSG_DONTWAIT;
 3005 
 3006 		if (timeout) {
 3007 			ktime_get_ts64(&timeout64);
 3008 			*timeout = timespec64_sub(end_time, timeout64);
 3009 			if (timeout->tv_sec < 0) {
 3010 				timeout->tv_sec = timeout->tv_nsec = 0;
 3011 				break;
 3012 			}
 3013 
 3014 			/* Timeout, return less than vlen datagrams */
 3015 			if (timeout->tv_nsec == 0 && timeout->tv_sec == 0)
 3016 				break;
 3017 		}
 3018 
 3019 		/* Out of band data, return right away */
 3020 		if (msg_sys.msg_flags & MSG_OOB)
 3021 			break;
 3022 		cond_resched();
 3023 	}
 3024 
 3025 	if (err == 0)
 3026 		return datagrams;
 3027 
 3028 	if (datagrams == 0)
 3029 		return err;
 3030 
 3031 	/*
 3032 	 * We may return less entries than requested (vlen) if the
 3033 	 * sock is non block and there aren't enough datagrams...
 3034 	 */
 3035 	if (err != -EAGAIN) {
 3036 		/*
 3037 		 * ... or  if recvmsg returns an error after we
 3038 		 * received some datagrams, where we record the
 3039 		 * error to return on the next call or if the
 3040 		 * app asks about it using getsockopt(SO_ERROR).
 3041 		 */
 3042 		WRITE_ONCE(sock->sk->sk_err, -err);
 3043 	}
 3044 	return datagrams;
 3045 }
 3046 
 3047 int __sys_recvmmsg(int fd, struct mmsghdr __user *mmsg,
 3048 		   unsigned int vlen, unsigned int flags,
 3049 		   struct __kernel_timespec __user *timeout,
 3050 		   struct old_timespec32 __user *timeout32)
 3051 {
 3052 	int datagrams;
 3053 	struct timespec64 timeout_sys;
 3054 
 3055 	if (timeout && get_timespec64(&timeout_sys, timeout))
 3056 		return -EFAULT;
 3057 
 3058 	if (timeout32 && get_old_timespec32(&timeout_sys, timeout32))
 3059 		return -EFAULT;
 3060 
 3061 	if (!timeout && !timeout32)
 3062 		return do_recvmmsg(fd, mmsg, vlen, flags, NULL);
 3063 
 3064 	datagrams = do_recvmmsg(fd, mmsg, vlen, flags, &timeout_sys);
 3065 
 3066 	if (datagrams <= 0)
 3067 		return datagrams;
 3068 
 3069 	if (timeout && put_timespec64(&timeout_sys, timeout))
 3070 		datagrams = -EFAULT;
 3071 
 3072 	if (timeout32 && put_old_timespec32(&timeout_sys, timeout32))
 3073 		datagrams = -EFAULT;
 3074 
 3075 	return datagrams;
 3076 }
 3077 
 3078 SYSCALL_DEFINE5(recvmmsg, int, fd, struct mmsghdr __user *, mmsg,
 3079 		unsigned int, vlen, unsigned int, flags,
 3080 		struct __kernel_timespec __user *, timeout)
 3081 {
 3082 	if (flags & MSG_CMSG_COMPAT)
 3083 		return -EINVAL;
 3084 
 3085 	return __sys_recvmmsg(fd, mmsg, vlen, flags, timeout, NULL);
 3086 }
 3087 
 3088 #ifdef CONFIG_COMPAT_32BIT_TIME
 3089 SYSCALL_DEFINE5(recvmmsg_time32, int, fd, struct mmsghdr __user *, mmsg,
 3090 		unsigned int, vlen, unsigned int, flags,
 3091 		struct old_timespec32 __user *, timeout)
 3092 {
 3093 	if (flags & MSG_CMSG_COMPAT)
 3094 		return -EINVAL;
 3095 
 3096 	return __sys_recvmmsg(fd, mmsg, vlen, flags, NULL, timeout);
 3097 }
 3098 #endif
 3099 
 3100 #ifdef __ARCH_WANT_SYS_SOCKETCALL
 3101 /* Argument list sizes for sys_socketcall */
 3102 #define AL(x) ((x) * sizeof(unsigned long))
 3103 static const unsigned char nargs[21] = {
 3104 	AL(0), AL(3), AL(3), AL(3), AL(2), AL(3),
 3105 	AL(3), AL(3), AL(4), AL(4), AL(4), AL(6),
 3106 	AL(6), AL(2), AL(5), AL(5), AL(3), AL(3),
 3107 	AL(4), AL(5), AL(4)
 3108 };
 3109 
 3110 #undef AL
 3111 
 3112 /*
 3113  *	System call vectors.
 3114  *
 3115  *	Argument checking cleaned up. Saved 20% in size.
 3116  *  This function doesn't need to set the kernel lock because
 3117  *  it is set by the callees.
 3118  */
 3119 
 3120 SYSCALL_DEFINE2(socketcall, int, call, unsigned long __user *, args)
 3121 {
 3122 	unsigned long a[AUDITSC_ARGS];
 3123 	unsigned long a0, a1;
 3124 	int err;
 3125 	unsigned int len;
 3126 
 3127 	if (call < 1 || call > SYS_SENDMMSG)
 3128 		return -EINVAL;
 3129 	call = array_index_nospec(call, SYS_SENDMMSG + 1);
 3130 
 3131 	len = nargs[call];
 3132 	if (len > sizeof(a))
 3133 		return -EINVAL;
 3134 
 3135 	/* copy_from_user should be SMP safe. */
 3136 	if (copy_from_user(a, args, len))
 3137 		return -EFAULT;
 3138 
 3139 	err = audit_socketcall(nargs[call] / sizeof(unsigned long), a);
 3140 	if (err)
 3141 		return err;
 3142 
 3143 	a0 = a[0];
 3144 	a1 = a[1];
 3145 
 3146 	switch (call) {
 3147 	case SYS_SOCKET:
 3148 		err = __sys_socket(a0, a1, a[2]);
 3149 		break;
 3150 	case SYS_BIND:
 3151 		err = __sys_bind(a0, (struct sockaddr __user *)a1, a[2]);
 3152 		break;
 3153 	case SYS_CONNECT:
 3154 		err = __sys_connect(a0, (struct sockaddr __user *)a1, a[2]);
 3155 		break;
 3156 	case SYS_LISTEN:
 3157 		err = __sys_listen(a0, a1);
 3158 		break;
 3159 	case SYS_ACCEPT:
 3160 		err = __sys_accept4(a0, (struct sockaddr __user *)a1,
 3161 				    (int __user *)a[2], 0);
 3162 		break;
 3163 	case SYS_GETSOCKNAME:
 3164 		err =
 3165 		    __sys_getsockname(a0, (struct sockaddr __user *)a1,
 3166 				      (int __user *)a[2]);
 3167 		break;
 3168 	case SYS_GETPEERNAME:
 3169 		err =
 3170 		    __sys_getpeername(a0, (struct sockaddr __user *)a1,
 3171 				      (int __user *)a[2]);
 3172 		break;
 3173 	case SYS_SOCKETPAIR:
 3174 		err = __sys_socketpair(a0, a1, a[2], (int __user *)a[3]);
 3175 		break;
 3176 	case SYS_SEND:
 3177 		err = __sys_sendto(a0, (void __user *)a1, a[2], a[3],
 3178 				   NULL, 0);
 3179 		break;
 3180 	case SYS_SENDTO:
 3181 		err = __sys_sendto(a0, (void __user *)a1, a[2], a[3],
 3182 				   (struct sockaddr __user *)a[4], a[5]);
 3183 		break;
 3184 	case SYS_RECV:
 3185 		err = __sys_recvfrom(a0, (void __user *)a1, a[2], a[3],
 3186 				     NULL, NULL);
 3187 		break;
 3188 	case SYS_RECVFROM:
 3189 		err = __sys_recvfrom(a0, (void __user *)a1, a[2], a[3],
 3190 				     (struct sockaddr __user *)a[4],
 3191 				     (int __user *)a[5]);
 3192 		break;
 3193 	case SYS_SHUTDOWN:
 3194 		err = __sys_shutdown(a0, a1);
 3195 		break;
 3196 	case SYS_SETSOCKOPT:
 3197 		err = __sys_setsockopt(a0, a1, a[2], (char __user *)a[3],
 3198 				       a[4]);
 3199 		break;
 3200 	case SYS_GETSOCKOPT:
 3201 		err =
 3202 		    __sys_getsockopt(a0, a1, a[2], (char __user *)a[3],
 3203 				     (int __user *)a[4]);
 3204 		break;
 3205 	case SYS_SENDMSG:
 3206 		err = __sys_sendmsg(a0, (struct user_msghdr __user *)a1,
 3207 				    a[2], true);
 3208 		break;
 3209 	case SYS_SENDMMSG:
 3210 		err = __sys_sendmmsg(a0, (struct mmsghdr __user *)a1, a[2],
 3211 				     a[3], true);
 3212 		break;
 3213 	case SYS_RECVMSG:
 3214 		err = __sys_recvmsg(a0, (struct user_msghdr __user *)a1,
 3215 				    a[2], true);
 3216 		break;
 3217 	case SYS_RECVMMSG:
 3218 		if (IS_ENABLED(CONFIG_64BIT))
 3219 			err = __sys_recvmmsg(a0, (struct mmsghdr __user *)a1,
 3220 					     a[2], a[3],
 3221 					     (struct __kernel_timespec __user *)a[4],
 3222 					     NULL);
 3223 		else
 3224 			err = __sys_recvmmsg(a0, (struct mmsghdr __user *)a1,
 3225 					     a[2], a[3], NULL,
 3226 					     (struct old_timespec32 __user *)a[4]);
 3227 		break;
 3228 	case SYS_ACCEPT4:
 3229 		err = __sys_accept4(a0, (struct sockaddr __user *)a1,
 3230 				    (int __user *)a[2], a[3]);
 3231 		break;
 3232 	default:
 3233 		err = -EINVAL;
 3234 		break;
 3235 	}
 3236 	return err;
 3237 }
 3238 
 3239 #endif				/* __ARCH_WANT_SYS_SOCKETCALL */
 3240 
 3241 /**
 3242  *	sock_register - add a socket protocol handler
 3243  *	@ops: description of protocol
 3244  *
 3245  *	This function is called by a protocol handler that wants to
 3246  *	advertise its address family, and have it linked into the
 3247  *	socket interface. The value ops->family corresponds to the
 3248  *	socket system call protocol family.
 3249  */
 3250 int sock_register(const struct net_proto_family *ops)
 3251 {
 3252 	int err;
 3253 
 3254 	if (ops->family >= NPROTO) {
 3255 		pr_crit("protocol %d >= NPROTO(%d)\n", ops->family, NPROTO);
 3256 		return -ENOBUFS;
 3257 	}
 3258 
 3259 	spin_lock(&net_family_lock);
 3260 	if (rcu_dereference_protected(net_families[ops->family],
 3261 				      lockdep_is_held(&net_family_lock)))
 3262 		err = -EEXIST;
 3263 	else {
 3264 		rcu_assign_pointer(net_families[ops->family], ops);
 3265 		err = 0;
 3266 	}
 3267 	spin_unlock(&net_family_lock);
 3268 
 3269 	pr_info("NET: Registered %s protocol family\n", pf_family_names[ops->family]);
 3270 	return err;
 3271 }
 3272 EXPORT_SYMBOL(sock_register);
 3273 
 3274 /**
 3275  *	sock_unregister - remove a protocol handler
 3276  *	@family: protocol family to remove
 3277  *
 3278  *	This function is called by a protocol handler that wants to
 3279  *	remove its address family, and have it unlinked from the
 3280  *	new socket creation.
 3281  *
 3282  *	If protocol handler is a module, then it can use module reference
 3283  *	counts to protect against new references. If protocol handler is not
 3284  *	a module then it needs to provide its own protection in
 3285  *	the ops->create routine.
 3286  */
 3287 void sock_unregister(int family)
 3288 {
 3289 	BUG_ON(family < 0 || family >= NPROTO);
 3290 
 3291 	spin_lock(&net_family_lock);
 3292 	RCU_INIT_POINTER(net_families[family], NULL);
 3293 	spin_unlock(&net_family_lock);
 3294 
 3295 	synchronize_rcu();
 3296 
 3297 	pr_info("NET: Unregistered %s protocol family\n", pf_family_names[family]);
 3298 }
 3299 EXPORT_SYMBOL(sock_unregister);
 3300 
 3301 bool sock_is_registered(int family)
 3302 {
 3303 	return family < NPROTO && rcu_access_pointer(net_families[family]);
 3304 }
 3305 
 3306 static int __init sock_init(void)
 3307 {
 3308 	int err;
 3309 	/*
 3310 	 *      Initialize the network sysctl infrastructure.
 3311 	 */
 3312 	err = net_sysctl_init();
 3313 	if (err)
 3314 		goto out;
 3315 
 3316 	/*
 3317 	 *      Initialize skbuff SLAB cache
 3318 	 */
 3319 	skb_init();
 3320 
 3321 	/*
 3322 	 *      Initialize the protocols module.
 3323 	 */
 3324 
 3325 	init_inodecache();
 3326 
 3327 	err = register_filesystem(&sock_fs_type);
 3328 	if (err)
 3329 		goto out;
 3330 	sock_mnt = kern_mount(&sock_fs_type);
 3331 	if (IS_ERR(sock_mnt)) {
 3332 		err = PTR_ERR(sock_mnt);
 3333 		goto out_mount;
 3334 	}
 3335 
 3336 	/* The real protocol initialization is performed in later initcalls.
 3337 	 */
 3338 
 3339 #ifdef CONFIG_NETFILTER
 3340 	err = netfilter_init();
 3341 	if (err)
 3342 		goto out;
 3343 #endif
 3344 
 3345 	ptp_classifier_init();
 3346 
 3347 out:
 3348 	return err;
 3349 
 3350 out_mount:
 3351 	unregister_filesystem(&sock_fs_type);
 3352 	goto out;
 3353 }
 3354 
 3355 core_initcall(sock_init);	/* early initcall */
 3356 
 3357 #ifdef CONFIG_PROC_FS
 3358 void socket_seq_show(struct seq_file *seq)
 3359 {
 3360 	seq_printf(seq, "sockets: used %d\n",
 3361 		   sock_inuse_get(seq->private));
 3362 }
 3363 #endif				/* CONFIG_PROC_FS */
 3364 
 3365 /* Handle the fact that while struct ifreq has the same *layout* on
 3366  * 32/64 for everything but ifreq::ifru_ifmap and ifreq::ifru_data,
 3367  * which are handled elsewhere, it still has different *size* due to
 3368  * ifreq::ifru_ifmap (which is 16 bytes on 32 bit, 24 bytes on 64-bit,
 3369  * resulting in struct ifreq being 32 and 40 bytes respectively).
 3370  * As a result, if the struct happens to be at the end of a page and
 3371  * the next page isn't readable/writable, we get a fault. To prevent
 3372  * that, copy back and forth to the full size.
 3373  */
 3374 int get_user_ifreq(struct ifreq *ifr, void __user **ifrdata, void __user *arg)
 3375 {
 3376 	if (in_compat_syscall()) {
 3377 		struct compat_ifreq *ifr32 = (struct compat_ifreq *)ifr;
 3378 
 3379 		memset(ifr, 0, sizeof(*ifr));
 3380 		if (copy_from_user(ifr32, arg, sizeof(*ifr32)))
 3381 			return -EFAULT;
 3382 
 3383 		if (ifrdata)
 3384 			*ifrdata = compat_ptr(ifr32->ifr_data);
 3385 
 3386 		return 0;
 3387 	}
 3388 
 3389 	if (copy_from_user(ifr, arg, sizeof(*ifr)))
 3390 		return -EFAULT;
 3391 
 3392 	if (ifrdata)
 3393 		*ifrdata = ifr->ifr_data;
 3394 
 3395 	return 0;
 3396 }
 3397 EXPORT_SYMBOL(get_user_ifreq);
 3398 
 3399 int put_user_ifreq(struct ifreq *ifr, void __user *arg)
 3400 {
 3401 	size_t size = sizeof(*ifr);
 3402 
 3403 	if (in_compat_syscall())
 3404 		size = sizeof(struct compat_ifreq);
 3405 
 3406 	if (copy_to_user(arg, ifr, size))
 3407 		return -EFAULT;
 3408 
 3409 	return 0;
 3410 }
 3411 EXPORT_SYMBOL(put_user_ifreq);
 3412 
 3413 #ifdef CONFIG_COMPAT
 3414 static int compat_siocwandev(struct net *net, struct compat_ifreq __user *uifr32)
 3415 {
 3416 	compat_uptr_t uptr32;
 3417 	struct ifreq ifr;
 3418 	void __user *saved;
 3419 	int err;
 3420 
 3421 	if (get_user_ifreq(&ifr, NULL, uifr32))
 3422 		return -EFAULT;
 3423 
 3424 	if (get_user(uptr32, &uifr32->ifr_settings.ifs_ifsu))
 3425 		return -EFAULT;
 3426 
 3427 	saved = ifr.ifr_settings.ifs_ifsu.raw_hdlc;
 3428 	ifr.ifr_settings.ifs_ifsu.raw_hdlc = compat_ptr(uptr32);
 3429 
 3430 	err = dev_ioctl(net, SIOCWANDEV, &ifr, NULL, NULL);
 3431 	if (!err) {
 3432 		ifr.ifr_settings.ifs_ifsu.raw_hdlc = saved;
 3433 		if (put_user_ifreq(&ifr, uifr32))
 3434 			err = -EFAULT;
 3435 	}
 3436 	return err;
 3437 }
 3438 
 3439 /* Handle ioctls that use ifreq::ifr_data and just need struct ifreq converted */
 3440 static int compat_ifr_data_ioctl(struct net *net, unsigned int cmd,
 3441 				 struct compat_ifreq __user *u_ifreq32)
 3442 {
 3443 	struct ifreq ifreq;
 3444 	void __user *data;
 3445 
 3446 	if (!is_socket_ioctl_cmd(cmd))
 3447 		return -ENOTTY;
 3448 	if (get_user_ifreq(&ifreq, &data, u_ifreq32))
 3449 		return -EFAULT;
 3450 	ifreq.ifr_data = data;
 3451 
 3452 	return dev_ioctl(net, cmd, &ifreq, data, NULL);
 3453 }
 3454 
 3455 static int compat_sock_ioctl_trans(struct file *file, struct socket *sock,
 3456 			 unsigned int cmd, unsigned long arg)
 3457 {
 3458 	void __user *argp = compat_ptr(arg);
 3459 	struct sock *sk = sock->sk;
 3460 	struct net *net = sock_net(sk);
 3461 	const struct proto_ops *ops;
 3462 
 3463 	if (cmd >= SIOCDEVPRIVATE && cmd <= (SIOCDEVPRIVATE + 15))
 3464 		return sock_ioctl(file, cmd, (unsigned long)argp);
 3465 
 3466 	switch (cmd) {
 3467 	case SIOCWANDEV:
 3468 		return compat_siocwandev(net, argp);
 3469 	case SIOCGSTAMP_OLD:
 3470 	case SIOCGSTAMPNS_OLD:
 3471 		ops = READ_ONCE(sock->ops);
 3472 		if (!ops->gettstamp)
 3473 			return -ENOIOCTLCMD;
 3474 		return ops->gettstamp(sock, argp, cmd == SIOCGSTAMP_OLD,
 3475 				      !COMPAT_USE_64BIT_TIME);
 3476 
 3477 	case SIOCETHTOOL:
 3478 	case SIOCBONDSLAVEINFOQUERY:
 3479 	case SIOCBONDINFOQUERY:
 3480 	case SIOCSHWTSTAMP:
 3481 	case SIOCGHWTSTAMP:
 3482 		return compat_ifr_data_ioctl(net, cmd, argp);
 3483 
 3484 	case FIOSETOWN:
 3485 	case SIOCSPGRP:
 3486 	case FIOGETOWN:
 3487 	case SIOCGPGRP:
 3488 	case SIOCBRADDBR:
 3489 	case SIOCBRDELBR:
 3490 	case SIOCBRADDIF:
 3491 	case SIOCBRDELIF:
 3492 	case SIOCGIFVLAN:
 3493 	case SIOCSIFVLAN:
 3494 	case SIOCGSKNS:
 3495 	case SIOCGSTAMP_NEW:
 3496 	case SIOCGSTAMPNS_NEW:
 3497 	case SIOCGIFCONF:
 3498 	case SIOCSIFBR:
 3499 	case SIOCGIFBR:
 3500 		return sock_ioctl(file, cmd, arg);
 3501 
 3502 	case SIOCGIFFLAGS:
 3503 	case SIOCSIFFLAGS:
 3504 	case SIOCGIFMAP:
 3505 	case SIOCSIFMAP:
 3506 	case SIOCGIFMETRIC:
 3507 	case SIOCSIFMETRIC:
 3508 	case SIOCGIFMTU:
 3509 	case SIOCSIFMTU:
 3510 	case SIOCGIFMEM:
 3511 	case SIOCSIFMEM:
 3512 	case SIOCGIFHWADDR:
 3513 	case SIOCSIFHWADDR:
 3514 	case SIOCADDMULTI:
 3515 	case SIOCDELMULTI:
 3516 	case SIOCGIFINDEX:
 3517 	case SIOCGIFADDR:
 3518 	case SIOCSIFADDR:
 3519 	case SIOCSIFHWBROADCAST:
 3520 	case SIOCDIFADDR:
 3521 	case SIOCGIFBRDADDR:
 3522 	case SIOCSIFBRDADDR:
 3523 	case SIOCGIFDSTADDR:
 3524 	case SIOCSIFDSTADDR:
 3525 	case SIOCGIFNETMASK:
 3526 	case SIOCSIFNETMASK:
 3527 	case SIOCSIFPFLAGS:
 3528 	case SIOCGIFPFLAGS:
 3529 	case SIOCGIFTXQLEN:
 3530 	case SIOCSIFTXQLEN:
 3531 	case SIOCGIFNAME:
 3532 	case SIOCSIFNAME:
 3533 	case SIOCGMIIPHY:
 3534 	case SIOCGMIIREG:
 3535 	case SIOCSMIIREG:
 3536 	case SIOCBONDENSLAVE:
 3537 	case SIOCBONDRELEASE:
 3538 	case SIOCBONDSETHWADDR:
 3539 	case SIOCBONDCHANGEACTIVE:
 3540 	case SIOCSARP:
 3541 	case SIOCGARP:
 3542 	case SIOCDARP:
 3543 	case SIOCOUTQ:
 3544 	case SIOCOUTQNSD:
 3545 	case SIOCATMARK:
 3546 		return sock_do_ioctl(net, sock, cmd, arg);
 3547 	}
 3548 
 3549 	return -ENOIOCTLCMD;
 3550 }
 3551 
 3552 static long compat_sock_ioctl(struct file *file, unsigned int cmd,
 3553 			      unsigned long arg)
 3554 {
 3555 	struct socket *sock = file->private_data;
 3556 	const struct proto_ops *ops = READ_ONCE(sock->ops);
 3557 	int ret = -ENOIOCTLCMD;
 3558 	struct sock *sk;
 3559 	struct net *net;
 3560 
 3561 	sk = sock->sk;
 3562 	net = sock_net(sk);
 3563 
 3564 	if (ops->compat_ioctl)
 3565 		ret = ops->compat_ioctl(sock, cmd, arg);
 3566 
 3567 	if (ret == -ENOIOCTLCMD &&
 3568 	    (cmd >= SIOCIWFIRST && cmd <= SIOCIWLAST))
 3569 		ret = compat_wext_handle_ioctl(net, cmd, arg);
 3570 
 3571 	if (ret == -ENOIOCTLCMD)
 3572 		ret = compat_sock_ioctl_trans(file, sock, cmd, arg);
 3573 
 3574 	return ret;
 3575 }
 3576 #endif
 3577 
 3578 /**
 3579  *	kernel_bind - bind an address to a socket (kernel space)
 3580  *	@sock: socket
 3581  *	@addr: address
 3582  *	@addrlen: length of address
 3583  *
 3584  *	Returns 0 or an error.
 3585  */
 3586 
 3587 int kernel_bind(struct socket *sock, struct sockaddr *addr, int addrlen)
 3588 {
 3589 	struct sockaddr_storage address;
 3590 
 3591 	memcpy(&address, addr, addrlen);
 3592 
 3593 	return READ_ONCE(sock->ops)->bind(sock, (struct sockaddr *)&address,
 3594 					  addrlen);
 3595 }
 3596 EXPORT_SYMBOL(kernel_bind);
 3597 
 3598 /**
 3599  *	kernel_listen - move socket to listening state (kernel space)
 3600  *	@sock: socket
 3601  *	@backlog: pending connections queue size
 3602  *
 3603  *	Returns 0 or an error.
 3604  */
 3605 
 3606 int kernel_listen(struct socket *sock, int backlog)
 3607 {
 3608 	return READ_ONCE(sock->ops)->listen(sock, backlog);
 3609 }
 3610 EXPORT_SYMBOL(kernel_listen);
 3611 
 3612 /**
 3613  *	kernel_accept - accept a connection (kernel space)
 3614  *	@sock: listening socket
 3615  *	@newsock: new connected socket
 3616  *	@flags: flags
 3617  *
 3618  *	@flags must be SOCK_CLOEXEC, SOCK_NONBLOCK or 0.
 3619  *	If it fails, @newsock is guaranteed to be %NULL.
 3620  *	Returns 0 or an error.
 3621  */
 3622 
 3623 int kernel_accept(struct socket *sock, struct socket **newsock, int flags)
 3624 {
 3625 	struct sock *sk = sock->sk;
 3626 	const struct proto_ops *ops = READ_ONCE(sock->ops);
 3627 	struct proto_accept_arg arg = {
 3628 		.flags = flags,
 3629 		.kern = true,
 3630 	};
 3631 	int err;
 3632 
 3633 	err = sock_create_lite(sk->sk_family, sk->sk_type, sk->sk_protocol,
 3634 			       newsock);
 3635 	if (err < 0)
 3636 		goto done;
 3637 
 3638 	err = ops->accept(sock, *newsock, &arg);
 3639 	if (err < 0) {
 3640 		sock_release(*newsock);
 3641 		*newsock = NULL;
 3642 		goto done;
 3643 	}
 3644 
 3645 	(*newsock)->ops = ops;
 3646 	__module_get(ops->owner);
 3647 
 3648 done:
 3649 	return err;
 3650 }
 3651 EXPORT_SYMBOL(kernel_accept);
 3652 
 3653 /**
 3654  *	kernel_connect - connect a socket (kernel space)
 3655  *	@sock: socket
 3656  *	@addr: address
 3657  *	@addrlen: address length
 3658  *	@flags: flags (O_NONBLOCK, ...)
 3659  *
 3660  *	For datagram sockets, @addr is the address to which datagrams are sent
 3661  *	by default, and the only address from which datagrams are received.
 3662  *	For stream sockets, attempts to connect to @addr.
 3663  *	Returns 0 or an error code.
 3664  */
 3665 
 3666 int kernel_connect(struct socket *sock, struct sockaddr *addr, int addrlen,
 3667 		   int flags)
 3668 {
 3669 	struct sockaddr_storage address;
 3670 
 3671 	memcpy(&address, addr, addrlen);
 3672 
 3673 	return READ_ONCE(sock->ops)->connect(sock, (struct sockaddr *)&address,
 3674 					     addrlen, flags);
 3675 }
 3676 EXPORT_SYMBOL(kernel_connect);
 3677 
 3678 /**
 3679  *	kernel_getsockname - get the address which the socket is bound (kernel space)
 3680  *	@sock: socket
 3681  *	@addr: address holder
 3682  *
 3683  * 	Fills the @addr pointer with the address which the socket is bound.
 3684  *	Returns the length of the address in bytes or an error code.
 3685  */
 3686 
 3687 int kernel_getsockname(struct socket *sock, struct sockaddr *addr)
 3688 {
 3689 	return READ_ONCE(sock->ops)->getname(sock, addr, 0);
 3690 }
 3691 EXPORT_SYMBOL(kernel_getsockname);
 3692 
 3693 /**
 3694  *	kernel_getpeername - get the address which the socket is connected (kernel space)
 3695  *	@sock: socket
 3696  *	@addr: address holder
 3697  *
 3698  * 	Fills the @addr pointer with the address which the socket is connected.
 3699  *	Returns the length of the address in bytes or an error code.
 3700  */
 3701 
 3702 int kernel_getpeername(struct socket *sock, struct sockaddr *addr)
 3703 {
 3704 	return READ_ONCE(sock->ops)->getname(sock, addr, 1);
 3705 }
 3706 EXPORT_SYMBOL(kernel_getpeername);
 3707 
 3708 /**
 3709  *	kernel_sock_shutdown - shut down part of a full-duplex connection (kernel space)
 3710  *	@sock: socket
 3711  *	@how: connection part
 3712  *
 3713  *	Returns 0 or an error.
 3714  */
 3715 
 3716 int kernel_sock_shutdown(struct socket *sock, enum sock_shutdown_cmd how)
 3717 {
 3718 	return READ_ONCE(sock->ops)->shutdown(sock, how);
 3719 }
 3720 EXPORT_SYMBOL(kernel_sock_shutdown);
 3721 
 3722 /**
 3723  *	kernel_sock_ip_overhead - returns the IP overhead imposed by a socket
 3724  *	@sk: socket
 3725  *
 3726  *	This routine returns the IP overhead imposed by a socket i.e.
 3727  *	the length of the underlying IP header, depending on whether
 3728  *	this is an IPv4 or IPv6 socket and the length from IP options turned
 3729  *	on at the socket. Assumes that the caller has a lock on the socket.
 3730  */
 3731 
 3732 u32 kernel_sock_ip_overhead(struct sock *sk)
 3733 {
 3734 	struct inet_sock *inet;
 3735 	struct ip_options_rcu *opt;
 3736 	u32 overhead = 0;
 3737 #if IS_ENABLED(CONFIG_IPV6)
 3738 	struct ipv6_pinfo *np;
 3739 	struct ipv6_txoptions *optv6 = NULL;
 3740 #endif /* IS_ENABLED(CONFIG_IPV6) */
 3741 
 3742 	if (!sk)
 3743 		return overhead;
 3744 
 3745 	switch (sk->sk_family) {
 3746 	case AF_INET:
 3747 		inet = inet_sk(sk);
 3748 		overhead += sizeof(struct iphdr);
 3749 		opt = rcu_dereference_protected(inet->inet_opt,
 3750 						sock_owned_by_user(sk));
 3751 		if (opt)
 3752 			overhead += opt->opt.optlen;
 3753 		return overhead;
 3754 #if IS_ENABLED(CONFIG_IPV6)
 3755 	case AF_INET6:
 3756 		np = inet6_sk(sk);
 3757 		overhead += sizeof(struct ipv6hdr);
 3758 		if (np)
 3759 			optv6 = rcu_dereference_protected(np->opt,
 3760 							  sock_owned_by_user(sk));
 3761 		if (optv6)
 3762 			overhead += (optv6->opt_flen + optv6->opt_nflen);
 3763 		return overhead;
 3764 #endif /* IS_ENABLED(CONFIG_IPV6) */
 3765 	default: /* Returns 0 overhead if the socket is not ipv4 or ipv6 */
 3766 		return overhead;
 3767 	}
 3768 }
 3769 EXPORT_SYMBOL(kernel_sock_ip_overhead);