Adding upstream version 5.10.209.upstream/5.10.209upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 3640 insertions, 0 deletions

diff --git a/net/socket.c b/net/socket.c
new file mode 100644
index 000000000..2a48aa89c
--- /dev/null
+++ b/net/socket.c
@@ -0,0 +1,3640 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * NET		An implementation of the SOCKET network access protocol.
+ *
+ * Version:	@(#)socket.c	1.1.93	18/02/95
+ *
+ * Authors:	Orest Zborowski, <obz@Kodak.COM>
+ *		Ross Biro
+ *		Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
+ *
+ * Fixes:
+ *		Anonymous	:	NOTSOCK/BADF cleanup. Error fix in
+ *					shutdown()
+ *		Alan Cox	:	verify_area() fixes
+ *		Alan Cox	:	Removed DDI
+ *		Jonathan Kamens	:	SOCK_DGRAM reconnect bug
+ *		Alan Cox	:	Moved a load of checks to the very
+ *					top level.
+ *		Alan Cox	:	Move address structures to/from user
+ *					mode above the protocol layers.
+ *		Rob Janssen	:	Allow 0 length sends.
+ *		Alan Cox	:	Asynchronous I/O support (cribbed from the
+ *					tty drivers).
+ *		Niibe Yutaka	:	Asynchronous I/O for writes (4.4BSD style)
+ *		Jeff Uphoff	:	Made max number of sockets command-line
+ *					configurable.
+ *		Matti Aarnio	:	Made the number of sockets dynamic,
+ *					to be allocated when needed, and mr.
+ *					Uphoff's max is used as max to be
+ *					allowed to allocate.
+ *		Linus		:	Argh. removed all the socket allocation
+ *					altogether: it's in the inode now.
+ *		Alan Cox	:	Made sock_alloc()/sock_release() public
+ *					for NetROM and future kernel nfsd type
+ *					stuff.
+ *		Alan Cox	:	sendmsg/recvmsg basics.
+ *		Tom Dyas	:	Export net symbols.
+ *		Marcin Dalecki	:	Fixed problems with CONFIG_NET="n".
+ *		Alan Cox	:	Added thread locking to sys_* calls
+ *					for sockets. May have errors at the
+ *					moment.
+ *		Kevin Buhr	:	Fixed the dumb errors in the above.
+ *		Andi Kleen	:	Some small cleanups, optimizations,
+ *					and fixed a copy_from_user() bug.
+ *		Tigran Aivazian	:	sys_send(args) calls sys_sendto(args, NULL, 0)
+ *		Tigran Aivazian	:	Made listen(2) backlog sanity checks
+ *					protocol-independent
+ *
+ *	This module is effectively the top level interface to the BSD socket
+ *	paradigm.
+ *
+ *	Based upon Swansea University Computer Society NET3.039
+ */
+
+#include <linux/mm.h>
+#include <linux/socket.h>
+#include <linux/file.h>
+#include <linux/net.h>
+#include <linux/interrupt.h>
+#include <linux/thread_info.h>
+#include <linux/rcupdate.h>
+#include <linux/netdevice.h>
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+#include <linux/mutex.h>
+#include <linux/if_bridge.h>
+#include <linux/if_frad.h>
+#include <linux/if_vlan.h>
+#include <linux/ptp_classify.h>
+#include <linux/init.h>
+#include <linux/poll.h>
+#include <linux/cache.h>
+#include <linux/module.h>
+#include <linux/highmem.h>
+#include <linux/mount.h>
+#include <linux/pseudo_fs.h>
+#include <linux/security.h>
+#include <linux/syscalls.h>
+#include <linux/compat.h>
+#include <linux/kmod.h>
+#include <linux/audit.h>
+#include <linux/wireless.h>
+#include <linux/nsproxy.h>
+#include <linux/magic.h>
+#include <linux/slab.h>
+#include <linux/xattr.h>
+#include <linux/nospec.h>
+#include <linux/indirect_call_wrapper.h>
+
+#include <linux/uaccess.h>
+#include <asm/unistd.h>
+
+#include <net/compat.h>
+#include <net/wext.h>
+#include <net/cls_cgroup.h>
+
+#include <net/sock.h>
+#include <linux/netfilter.h>
+
+#include <linux/if_tun.h>
+#include <linux/ipv6_route.h>
+#include <linux/route.h>
+#include <linux/termios.h>
+#include <linux/sockios.h>
+#include <net/busy_poll.h>
+#include <linux/errqueue.h>
+
+#ifdef CONFIG_NET_RX_BUSY_POLL
+unsigned int sysctl_net_busy_read __read_mostly;
+unsigned int sysctl_net_busy_poll __read_mostly;
+#endif
+
+static ssize_t sock_read_iter(struct kiocb *iocb, struct iov_iter *to);
+static ssize_t sock_write_iter(struct kiocb *iocb, struct iov_iter *from);
+static int sock_mmap(struct file *file, struct vm_area_struct *vma);
+
+static int sock_close(struct inode *inode, struct file *file);
+static __poll_t sock_poll(struct file *file,
+			      struct poll_table_struct *wait);
+static long sock_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
+#ifdef CONFIG_COMPAT
+static long compat_sock_ioctl(struct file *file,
+			      unsigned int cmd, unsigned long arg);
+#endif
+static int sock_fasync(int fd, struct file *filp, int on);
+static ssize_t sock_sendpage(struct file *file, struct page *page,
+			     int offset, size_t size, loff_t *ppos, int more);
+static ssize_t sock_splice_read(struct file *file, loff_t *ppos,
+				struct pipe_inode_info *pipe, size_t len,
+				unsigned int flags);
+
+#ifdef CONFIG_PROC_FS
+static void sock_show_fdinfo(struct seq_file *m, struct file *f)
+{
+	struct socket *sock = f->private_data;
+
+	if (sock->ops->show_fdinfo)
+		sock->ops->show_fdinfo(m, sock);
+}
+#else
+#define sock_show_fdinfo NULL
+#endif
+
+/*
+ *	Socket files have a set of 'special' operations as well as the generic file ones. These don't appear
+ *	in the operation structures but are done directly via the socketcall() multiplexor.
+ */
+
+static const struct file_operations socket_file_ops = {
+	.owner =	THIS_MODULE,
+	.llseek =	no_llseek,
+	.read_iter =	sock_read_iter,
+	.write_iter =	sock_write_iter,
+	.poll =		sock_poll,
+	.unlocked_ioctl = sock_ioctl,
+#ifdef CONFIG_COMPAT
+	.compat_ioctl = compat_sock_ioctl,
+#endif
+	.mmap =		sock_mmap,
+	.release =	sock_close,
+	.fasync =	sock_fasync,
+	.sendpage =	sock_sendpage,
+	.splice_write = generic_splice_sendpage,
+	.splice_read =	sock_splice_read,
+	.show_fdinfo =	sock_show_fdinfo,
+};
+
+/*
+ *	The protocol list. Each protocol is registered in here.
+ */
+
+static DEFINE_SPINLOCK(net_family_lock);
+static const struct net_proto_family __rcu *net_families[NPROTO] __read_mostly;
+
+/*
+ * Support routines.
+ * Move socket addresses back and forth across the kernel/user
+ * divide and look after the messy bits.
+ */
+
+/**
+ *	move_addr_to_kernel	-	copy a socket address into kernel space
+ *	@uaddr: Address in user space
+ *	@kaddr: Address in kernel space
+ *	@ulen: Length in user space
+ *
+ *	The address is copied into kernel space. If the provided address is
+ *	too long an error code of -EINVAL is returned. If the copy gives
+ *	invalid addresses -EFAULT is returned. On a success 0 is returned.
+ */
+
+int move_addr_to_kernel(void __user *uaddr, int ulen, struct sockaddr_storage *kaddr)
+{
+	if (ulen < 0 || ulen > sizeof(struct sockaddr_storage))
+		return -EINVAL;
+	if (ulen == 0)
+		return 0;
+	if (copy_from_user(kaddr, uaddr, ulen))
+		return -EFAULT;
+	return audit_sockaddr(ulen, kaddr);
+}
+
+/**
+ *	move_addr_to_user	-	copy an address to user space
+ *	@kaddr: kernel space address
+ *	@klen: length of address in kernel
+ *	@uaddr: user space address
+ *	@ulen: pointer to user length field
+ *
+ *	The value pointed to by ulen on entry is the buffer length available.
+ *	This is overwritten with the buffer space used. -EINVAL is returned
+ *	if an overlong buffer is specified or a negative buffer size. -EFAULT
+ *	is returned if either the buffer or the length field are not
+ *	accessible.
+ *	After copying the data up to the limit the user specifies, the true
+ *	length of the data is written over the length limit the user
+ *	specified. Zero is returned for a success.
+ */
+
+static int move_addr_to_user(struct sockaddr_storage *kaddr, int klen,
+			     void __user *uaddr, int __user *ulen)
+{
+	int err;
+	int len;
+
+	BUG_ON(klen > sizeof(struct sockaddr_storage));
+	err = get_user(len, ulen);
+	if (err)
+		return err;
+	if (len > klen)
+		len = klen;
+	if (len < 0)
+		return -EINVAL;
+	if (len) {
+		if (audit_sockaddr(klen, kaddr))
+			return -ENOMEM;
+		if (copy_to_user(uaddr, kaddr, len))
+			return -EFAULT;
+	}
+	/*
+	 *      "fromlen shall refer to the value before truncation.."
+	 *                      1003.1g
+	 */
+	return __put_user(klen, ulen);
+}
+
+static struct kmem_cache *sock_inode_cachep __ro_after_init;
+
+static struct inode *sock_alloc_inode(struct super_block *sb)
+{
+	struct socket_alloc *ei;
+
+	ei = kmem_cache_alloc(sock_inode_cachep, GFP_KERNEL);
+	if (!ei)
+		return NULL;
+	init_waitqueue_head(&ei->socket.wq.wait);
+	ei->socket.wq.fasync_list = NULL;
+	ei->socket.wq.flags = 0;
+
+	ei->socket.state = SS_UNCONNECTED;
+	ei->socket.flags = 0;
+	ei->socket.ops = NULL;
+	ei->socket.sk = NULL;
+	ei->socket.file = NULL;
+
+	return &ei->vfs_inode;
+}
+
+static void sock_free_inode(struct inode *inode)
+{
+	struct socket_alloc *ei;
+
+	ei = container_of(inode, struct socket_alloc, vfs_inode);
+	kmem_cache_free(sock_inode_cachep, ei);
+}
+
+static void init_once(void *foo)
+{
+	struct socket_alloc *ei = (struct socket_alloc *)foo;
+
+	inode_init_once(&ei->vfs_inode);
+}
+
+static void init_inodecache(void)
+{
+	sock_inode_cachep = kmem_cache_create("sock_inode_cache",
+					      sizeof(struct socket_alloc),
+					      0,
+					      (SLAB_HWCACHE_ALIGN |
+					       SLAB_RECLAIM_ACCOUNT |
+					       SLAB_MEM_SPREAD | SLAB_ACCOUNT),
+					      init_once);
+	BUG_ON(sock_inode_cachep == NULL);
+}
+
+static const struct super_operations sockfs_ops = {
+	.alloc_inode	= sock_alloc_inode,
+	.free_inode	= sock_free_inode,
+	.statfs		= simple_statfs,
+};
+
+/*
+ * sockfs_dname() is called from d_path().
+ */
+static char *sockfs_dname(struct dentry *dentry, char *buffer, int buflen)
+{
+	return dynamic_dname(dentry, buffer, buflen, "socket:[%lu]",
+				d_inode(dentry)->i_ino);
+}
+
+static const struct dentry_operations sockfs_dentry_operations = {
+	.d_dname  = sockfs_dname,
+};
+
+static int sockfs_xattr_get(const struct xattr_handler *handler,
+			    struct dentry *dentry, struct inode *inode,
+			    const char *suffix, void *value, size_t size)
+{
+	if (value) {
+		if (dentry->d_name.len + 1 > size)
+			return -ERANGE;
+		memcpy(value, dentry->d_name.name, dentry->d_name.len + 1);
+	}
+	return dentry->d_name.len + 1;
+}
+
+#define XATTR_SOCKPROTONAME_SUFFIX "sockprotoname"
+#define XATTR_NAME_SOCKPROTONAME (XATTR_SYSTEM_PREFIX XATTR_SOCKPROTONAME_SUFFIX)
+#define XATTR_NAME_SOCKPROTONAME_LEN (sizeof(XATTR_NAME_SOCKPROTONAME)-1)
+
+static const struct xattr_handler sockfs_xattr_handler = {
+	.name = XATTR_NAME_SOCKPROTONAME,
+	.get = sockfs_xattr_get,
+};
+
+static int sockfs_security_xattr_set(const struct xattr_handler *handler,
+				     struct dentry *dentry, struct inode *inode,
+				     const char *suffix, const void *value,
+				     size_t size, int flags)
+{
+	/* Handled by LSM. */
+	return -EAGAIN;
+}
+
+static const struct xattr_handler sockfs_security_xattr_handler = {
+	.prefix = XATTR_SECURITY_PREFIX,
+	.set = sockfs_security_xattr_set,
+};
+
+static const struct xattr_handler *sockfs_xattr_handlers[] = {
+	&sockfs_xattr_handler,
+	&sockfs_security_xattr_handler,
+	NULL
+};
+
+static int sockfs_init_fs_context(struct fs_context *fc)
+{
+	struct pseudo_fs_context *ctx = init_pseudo(fc, SOCKFS_MAGIC);
+	if (!ctx)
+		return -ENOMEM;
+	ctx->ops = &sockfs_ops;
+	ctx->dops = &sockfs_dentry_operations;
+	ctx->xattr = sockfs_xattr_handlers;
+	return 0;
+}
+
+static struct vfsmount *sock_mnt __read_mostly;
+
+static struct file_system_type sock_fs_type = {
+	.name =		"sockfs",
+	.init_fs_context = sockfs_init_fs_context,
+	.kill_sb =	kill_anon_super,
+};
+
+/*
+ *	Obtains the first available file descriptor and sets it up for use.
+ *
+ *	These functions create file structures and maps them to fd space
+ *	of the current process. On success it returns file descriptor
+ *	and file struct implicitly stored in sock->file.
+ *	Note that another thread may close file descriptor before we return
+ *	from this function. We use the fact that now we do not refer
+ *	to socket after mapping. If one day we will need it, this
+ *	function will increment ref. count on file by 1.
+ *
+ *	In any case returned fd MAY BE not valid!
+ *	This race condition is unavoidable
+ *	with shared fd spaces, we cannot solve it inside kernel,
+ *	but we take care of internal coherence yet.
+ */
+
+/**
+ *	sock_alloc_file - Bind a &socket to a &file
+ *	@sock: socket
+ *	@flags: file status flags
+ *	@dname: protocol name
+ *
+ *	Returns the &file bound with @sock, implicitly storing it
+ *	in sock->file. If dname is %NULL, sets to "".
+ *	On failure the return is a ERR pointer (see linux/err.h).
+ *	This function uses GFP_KERNEL internally.
+ */
+
+struct file *sock_alloc_file(struct socket *sock, int flags, const char *dname)
+{
+	struct file *file;
+
+	if (!dname)
+		dname = sock->sk ? sock->sk->sk_prot_creator->name : "";
+
+	file = alloc_file_pseudo(SOCK_INODE(sock), sock_mnt, dname,
+				O_RDWR | (flags & O_NONBLOCK),
+				&socket_file_ops);
+	if (IS_ERR(file)) {
+		sock_release(sock);
+		return file;
+	}
+
+	sock->file = file;
+	file->private_data = sock;
+	stream_open(SOCK_INODE(sock), file);
+	return file;
+}
+EXPORT_SYMBOL(sock_alloc_file);
+
+static int sock_map_fd(struct socket *sock, int flags)
+{
+	struct file *newfile;
+	int fd = get_unused_fd_flags(flags);
+	if (unlikely(fd < 0)) {
+		sock_release(sock);
+		return fd;
+	}
+
+	newfile = sock_alloc_file(sock, flags, NULL);
+	if (!IS_ERR(newfile)) {
+		fd_install(fd, newfile);
+		return fd;
+	}
+
+	put_unused_fd(fd);
+	return PTR_ERR(newfile);
+}
+
+/**
+ *	sock_from_file - Return the &socket bounded to @file.
+ *	@file: file
+ *	@err: pointer to an error code return
+ *
+ *	On failure returns %NULL and assigns -ENOTSOCK to @err.
+ */
+
+struct socket *sock_from_file(struct file *file, int *err)
+{
+	if (file->f_op == &socket_file_ops)
+		return file->private_data;	/* set in sock_map_fd */
+
+	*err = -ENOTSOCK;
+	return NULL;
+}
+EXPORT_SYMBOL(sock_from_file);
+
+/**
+ *	sockfd_lookup - Go from a file number to its socket slot
+ *	@fd: file handle
+ *	@err: pointer to an error code return
+ *
+ *	The file handle passed in is locked and the socket it is bound
+ *	to is returned. If an error occurs the err pointer is overwritten
+ *	with a negative errno code and NULL is returned. The function checks
+ *	for both invalid handles and passing a handle which is not a socket.
+ *
+ *	On a success the socket object pointer is returned.
+ */
+
+struct socket *sockfd_lookup(int fd, int *err)
+{
+	struct file *file;
+	struct socket *sock;
+
+	file = fget(fd);
+	if (!file) {
+		*err = -EBADF;
+		return NULL;
+	}
+
+	sock = sock_from_file(file, err);
+	if (!sock)
+		fput(file);
+	return sock;
+}
+EXPORT_SYMBOL(sockfd_lookup);
+
+static struct socket *sockfd_lookup_light(int fd, int *err, int *fput_needed)
+{
+	struct fd f = fdget(fd);
+	struct socket *sock;
+
+	*err = -EBADF;
+	if (f.file) {
+		sock = sock_from_file(f.file, err);
+		if (likely(sock)) {
+			*fput_needed = f.flags & FDPUT_FPUT;
+			return sock;
+		}
+		fdput(f);
+	}
+	return NULL;
+}
+
+static ssize_t sockfs_listxattr(struct dentry *dentry, char *buffer,
+				size_t size)
+{
+	ssize_t len;
+	ssize_t used = 0;
+
+	len = security_inode_listsecurity(d_inode(dentry), buffer, size);
+	if (len < 0)
+		return len;
+	used += len;
+	if (buffer) {
+		if (size < used)
+			return -ERANGE;
+		buffer += len;
+	}
+
+	len = (XATTR_NAME_SOCKPROTONAME_LEN + 1);
+	used += len;
+	if (buffer) {
+		if (size < used)
+			return -ERANGE;
+		memcpy(buffer, XATTR_NAME_SOCKPROTONAME, len);
+		buffer += len;
+	}
+
+	return used;
+}
+
+static int sockfs_setattr(struct dentry *dentry, struct iattr *iattr)
+{
+	int err = simple_setattr(dentry, iattr);
+
+	if (!err && (iattr->ia_valid & ATTR_UID)) {
+		struct socket *sock = SOCKET_I(d_inode(dentry));
+
+		if (sock->sk)
+			sock->sk->sk_uid = iattr->ia_uid;
+		else
+			err = -ENOENT;
+	}
+
+	return err;
+}
+
+static const struct inode_operations sockfs_inode_ops = {
+	.listxattr = sockfs_listxattr,
+	.setattr = sockfs_setattr,
+};
+
+/**
+ *	sock_alloc - allocate a socket
+ *
+ *	Allocate a new inode and socket object. The two are bound together
+ *	and initialised. The socket is then returned. If we are out of inodes
+ *	NULL is returned. This functions uses GFP_KERNEL internally.
+ */
+
+struct socket *sock_alloc(void)
+{
+	struct inode *inode;
+	struct socket *sock;
+
+	inode = new_inode_pseudo(sock_mnt->mnt_sb);
+	if (!inode)
+		return NULL;
+
+	sock = SOCKET_I(inode);
+
+	inode->i_ino = get_next_ino();
+	inode->i_mode = S_IFSOCK | S_IRWXUGO;
+	inode->i_uid = current_fsuid();
+	inode->i_gid = current_fsgid();
+	inode->i_op = &sockfs_inode_ops;
+
+	return sock;
+}
+EXPORT_SYMBOL(sock_alloc);
+
+static void __sock_release(struct socket *sock, struct inode *inode)
+{
+	if (sock->ops) {
+		struct module *owner = sock->ops->owner;
+
+		if (inode)
+			inode_lock(inode);
+		sock->ops->release(sock);
+		sock->sk = NULL;
+		if (inode)
+			inode_unlock(inode);
+		sock->ops = NULL;
+		module_put(owner);
+	}
+
+	if (sock->wq.fasync_list)
+		pr_err("%s: fasync list not empty!\n", __func__);
+
+	if (!sock->file) {
+		iput(SOCK_INODE(sock));
+		return;
+	}
+	sock->file = NULL;
+}
+
+/**
+ *	sock_release - close a socket
+ *	@sock: socket to close
+ *
+ *	The socket is released from the protocol stack if it has a release
+ *	callback, and the inode is then released if the socket is bound to
+ *	an inode not a file.
+ */
+void sock_release(struct socket *sock)
+{
+	__sock_release(sock, NULL);
+}
+EXPORT_SYMBOL(sock_release);
+
+void __sock_tx_timestamp(__u16 tsflags, __u8 *tx_flags)
+{
+	u8 flags = *tx_flags;
+
+	if (tsflags & SOF_TIMESTAMPING_TX_HARDWARE)
+		flags |= SKBTX_HW_TSTAMP;
+
+	if (tsflags & SOF_TIMESTAMPING_TX_SOFTWARE)
+		flags |= SKBTX_SW_TSTAMP;
+
+	if (tsflags & SOF_TIMESTAMPING_TX_SCHED)
+		flags |= SKBTX_SCHED_TSTAMP;
+
+	*tx_flags = flags;
+}
+EXPORT_SYMBOL(__sock_tx_timestamp);
+
+INDIRECT_CALLABLE_DECLARE(int inet_sendmsg(struct socket *, struct msghdr *,
+					   size_t));
+INDIRECT_CALLABLE_DECLARE(int inet6_sendmsg(struct socket *, struct msghdr *,
+					    size_t));
+static inline int sock_sendmsg_nosec(struct socket *sock, struct msghdr *msg)
+{
+	int ret = INDIRECT_CALL_INET(sock->ops->sendmsg, inet6_sendmsg,
+				     inet_sendmsg, sock, msg,
+				     msg_data_left(msg));
+	BUG_ON(ret == -EIOCBQUEUED);
+	return ret;
+}
+
+static int __sock_sendmsg(struct socket *sock, struct msghdr *msg)
+{
+	int err = security_socket_sendmsg(sock, msg,
+					  msg_data_left(msg));
+
+	return err ?: sock_sendmsg_nosec(sock, msg);
+}
+
+/**
+ *	sock_sendmsg - send a message through @sock
+ *	@sock: socket
+ *	@msg: message to send
+ *
+ *	Sends @msg through @sock, passing through LSM.
+ *	Returns the number of bytes sent, or an error code.
+ */
+int sock_sendmsg(struct socket *sock, struct msghdr *msg)
+{
+	struct sockaddr_storage *save_addr = (struct sockaddr_storage *)msg->msg_name;
+	struct sockaddr_storage address;
+	int save_len = msg->msg_namelen;
+	int ret;
+
+	if (msg->msg_name) {
+		memcpy(&address, msg->msg_name, msg->msg_namelen);
+		msg->msg_name = &address;
+	}
+
+	ret = __sock_sendmsg(sock, msg);
+	msg->msg_name = save_addr;
+	msg->msg_namelen = save_len;
+
+	return ret;
+}
+EXPORT_SYMBOL(sock_sendmsg);
+
+/**
+ *	kernel_sendmsg - send a message through @sock (kernel-space)
+ *	@sock: socket
+ *	@msg: message header
+ *	@vec: kernel vec
+ *	@num: vec array length
+ *	@size: total message data size
+ *
+ *	Builds the message data with @vec and sends it through @sock.
+ *	Returns the number of bytes sent, or an error code.
+ */
+
+int kernel_sendmsg(struct socket *sock, struct msghdr *msg,
+		   struct kvec *vec, size_t num, size_t size)
+{
+	iov_iter_kvec(&msg->msg_iter, WRITE, vec, num, size);
+	return sock_sendmsg(sock, msg);
+}
+EXPORT_SYMBOL(kernel_sendmsg);
+
+/**
+ *	kernel_sendmsg_locked - send a message through @sock (kernel-space)
+ *	@sk: sock
+ *	@msg: message header
+ *	@vec: output s/g array
+ *	@num: output s/g array length
+ *	@size: total message data size
+ *
+ *	Builds the message data with @vec and sends it through @sock.
+ *	Returns the number of bytes sent, or an error code.
+ *	Caller must hold @sk.
+ */
+
+int kernel_sendmsg_locked(struct sock *sk, struct msghdr *msg,
+			  struct kvec *vec, size_t num, size_t size)
+{
+	struct socket *sock = sk->sk_socket;
+
+	if (!sock->ops->sendmsg_locked)
+		return sock_no_sendmsg_locked(sk, msg, size);
+
+	iov_iter_kvec(&msg->msg_iter, WRITE, vec, num, size);
+
+	return sock->ops->sendmsg_locked(sk, msg, msg_data_left(msg));
+}
+EXPORT_SYMBOL(kernel_sendmsg_locked);
+
+static bool skb_is_err_queue(const struct sk_buff *skb)
+{
+	/* pkt_type of skbs enqueued on the error queue are set to
+	 * PACKET_OUTGOING in skb_set_err_queue(). This is only safe to do
+	 * in recvmsg, since skbs received on a local socket will never
+	 * have a pkt_type of PACKET_OUTGOING.
+	 */
+	return skb->pkt_type == PACKET_OUTGOING;
+}
+
+/* On transmit, software and hardware timestamps are returned independently.
+ * As the two skb clones share the hardware timestamp, which may be updated
+ * before the software timestamp is received, a hardware TX timestamp may be
+ * returned only if there is no software TX timestamp. Ignore false software
+ * timestamps, which may be made in the __sock_recv_timestamp() call when the
+ * option SO_TIMESTAMP_OLD(NS) is enabled on the socket, even when the skb has a
+ * hardware timestamp.
+ */
+static bool skb_is_swtx_tstamp(const struct sk_buff *skb, int false_tstamp)
+{
+	return skb->tstamp && !false_tstamp && skb_is_err_queue(skb);
+}
+
+static void put_ts_pktinfo(struct msghdr *msg, struct sk_buff *skb)
+{
+	struct scm_ts_pktinfo ts_pktinfo;
+	struct net_device *orig_dev;
+
+	if (!skb_mac_header_was_set(skb))
+		return;
+
+	memset(&ts_pktinfo, 0, sizeof(ts_pktinfo));
+
+	rcu_read_lock();
+	orig_dev = dev_get_by_napi_id(skb_napi_id(skb));
+	if (orig_dev)
+		ts_pktinfo.if_index = orig_dev->ifindex;
+	rcu_read_unlock();
+
+	ts_pktinfo.pkt_length = skb->len - skb_mac_offset(skb);
+	put_cmsg(msg, SOL_SOCKET, SCM_TIMESTAMPING_PKTINFO,
+		 sizeof(ts_pktinfo), &ts_pktinfo);
+}
+
+/*
+ * called from sock_recv_timestamp() if sock_flag(sk, SOCK_RCVTSTAMP)
+ */
+void __sock_recv_timestamp(struct msghdr *msg, struct sock *sk,
+	struct sk_buff *skb)
+{
+	int need_software_tstamp = sock_flag(sk, SOCK_RCVTSTAMP);
+	int new_tstamp = sock_flag(sk, SOCK_TSTAMP_NEW);
+	struct scm_timestamping_internal tss;
+
+	int empty = 1, false_tstamp = 0;
+	struct skb_shared_hwtstamps *shhwtstamps =
+		skb_hwtstamps(skb);
+
+	/* Race occurred between timestamp enabling and packet
+	   receiving.  Fill in the current time for now. */
+	if (need_software_tstamp && skb->tstamp == 0) {
+		__net_timestamp(skb);
+		false_tstamp = 1;
+	}
+
+	if (need_software_tstamp) {
+		if (!sock_flag(sk, SOCK_RCVTSTAMPNS)) {
+			if (new_tstamp) {
+				struct __kernel_sock_timeval tv;
+
+				skb_get_new_timestamp(skb, &tv);
+				put_cmsg(msg, SOL_SOCKET, SO_TIMESTAMP_NEW,
+					 sizeof(tv), &tv);
+			} else {
+				struct __kernel_old_timeval tv;
+
+				skb_get_timestamp(skb, &tv);
+				put_cmsg(msg, SOL_SOCKET, SO_TIMESTAMP_OLD,
+					 sizeof(tv), &tv);
+			}
+		} else {
+			if (new_tstamp) {
+				struct __kernel_timespec ts;
+
+				skb_get_new_timestampns(skb, &ts);
+				put_cmsg(msg, SOL_SOCKET, SO_TIMESTAMPNS_NEW,
+					 sizeof(ts), &ts);
+			} else {
+				struct __kernel_old_timespec ts;
+
+				skb_get_timestampns(skb, &ts);
+				put_cmsg(msg, SOL_SOCKET, SO_TIMESTAMPNS_OLD,
+					 sizeof(ts), &ts);
+			}
+		}
+	}
+
+	memset(&tss, 0, sizeof(tss));
+	if ((sk->sk_tsflags & SOF_TIMESTAMPING_SOFTWARE) &&
+	    ktime_to_timespec64_cond(skb->tstamp, tss.ts + 0))
+		empty = 0;
+	if (shhwtstamps &&
+	    (sk->sk_tsflags & SOF_TIMESTAMPING_RAW_HARDWARE) &&
+	    !skb_is_swtx_tstamp(skb, false_tstamp) &&
+	    ktime_to_timespec64_cond(shhwtstamps->hwtstamp, tss.ts + 2)) {
+		empty = 0;
+		if ((sk->sk_tsflags & SOF_TIMESTAMPING_OPT_PKTINFO) &&
+		    !skb_is_err_queue(skb))
+			put_ts_pktinfo(msg, skb);
+	}
+	if (!empty) {
+		if (sock_flag(sk, SOCK_TSTAMP_NEW))
+			put_cmsg_scm_timestamping64(msg, &tss);
+		else
+			put_cmsg_scm_timestamping(msg, &tss);
+
+		if (skb_is_err_queue(skb) && skb->len &&
+		    SKB_EXT_ERR(skb)->opt_stats)
+			put_cmsg(msg, SOL_SOCKET, SCM_TIMESTAMPING_OPT_STATS,
+				 skb->len, skb->data);
+	}
+}
+EXPORT_SYMBOL_GPL(__sock_recv_timestamp);
+
+void __sock_recv_wifi_status(struct msghdr *msg, struct sock *sk,
+	struct sk_buff *skb)
+{
+	int ack;
+
+	if (!sock_flag(sk, SOCK_WIFI_STATUS))
+		return;
+	if (!skb->wifi_acked_valid)
+		return;
+
+	ack = skb->wifi_acked;
+
+	put_cmsg(msg, SOL_SOCKET, SCM_WIFI_STATUS, sizeof(ack), &ack);
+}
+EXPORT_SYMBOL_GPL(__sock_recv_wifi_status);
+
+static inline void sock_recv_drops(struct msghdr *msg, struct sock *sk,
+				   struct sk_buff *skb)
+{
+	if (sock_flag(sk, SOCK_RXQ_OVFL) && skb && SOCK_SKB_CB(skb)->dropcount)
+		put_cmsg(msg, SOL_SOCKET, SO_RXQ_OVFL,
+			sizeof(__u32), &SOCK_SKB_CB(skb)->dropcount);
+}
+
+void __sock_recv_ts_and_drops(struct msghdr *msg, struct sock *sk,
+	struct sk_buff *skb)
+{
+	sock_recv_timestamp(msg, sk, skb);
+	sock_recv_drops(msg, sk, skb);
+}
+EXPORT_SYMBOL_GPL(__sock_recv_ts_and_drops);
+
+INDIRECT_CALLABLE_DECLARE(int inet_recvmsg(struct socket *, struct msghdr *,
+					   size_t, int));
+INDIRECT_CALLABLE_DECLARE(int inet6_recvmsg(struct socket *, struct msghdr *,
+					    size_t, int));
+static inline int sock_recvmsg_nosec(struct socket *sock, struct msghdr *msg,
+				     int flags)
+{
+	return INDIRECT_CALL_INET(sock->ops->recvmsg, inet6_recvmsg,
+				  inet_recvmsg, sock, msg, msg_data_left(msg),
+				  flags);
+}
+
+/**
+ *	sock_recvmsg - receive a message from @sock
+ *	@sock: socket
+ *	@msg: message to receive
+ *	@flags: message flags
+ *
+ *	Receives @msg from @sock, passing through LSM. Returns the total number
+ *	of bytes received, or an error.
+ */
+int sock_recvmsg(struct socket *sock, struct msghdr *msg, int flags)
+{
+	int err = security_socket_recvmsg(sock, msg, msg_data_left(msg), flags);
+
+	return err ?: sock_recvmsg_nosec(sock, msg, flags);
+}
+EXPORT_SYMBOL(sock_recvmsg);
+
+/**
+ *	kernel_recvmsg - Receive a message from a socket (kernel space)
+ *	@sock: The socket to receive the message from
+ *	@msg: Received message
+ *	@vec: Input s/g array for message data
+ *	@num: Size of input s/g array
+ *	@size: Number of bytes to read
+ *	@flags: Message flags (MSG_DONTWAIT, etc...)
+ *
+ *	On return the msg structure contains the scatter/gather array passed in the
+ *	vec argument. The array is modified so that it consists of the unfilled
+ *	portion of the original array.
+ *
+ *	The returned value is the total number of bytes received, or an error.
+ */
+
+int kernel_recvmsg(struct socket *sock, struct msghdr *msg,
+		   struct kvec *vec, size_t num, size_t size, int flags)
+{
+	msg->msg_control_is_user = false;
+	iov_iter_kvec(&msg->msg_iter, READ, vec, num, size);
+	return sock_recvmsg(sock, msg, flags);
+}
+EXPORT_SYMBOL(kernel_recvmsg);
+
+static ssize_t sock_sendpage(struct file *file, struct page *page,
+			     int offset, size_t size, loff_t *ppos, int more)
+{
+	struct socket *sock;
+	int flags;
+
+	sock = file->private_data;
+
+	flags = (file->f_flags & O_NONBLOCK) ? MSG_DONTWAIT : 0;
+	/* more is a combination of MSG_MORE and MSG_SENDPAGE_NOTLAST */
+	flags |= more;
+
+	return kernel_sendpage(sock, page, offset, size, flags);
+}
+
+static ssize_t sock_splice_read(struct file *file, loff_t *ppos,
+				struct pipe_inode_info *pipe, size_t len,
+				unsigned int flags)
+{
+	struct socket *sock = file->private_data;
+
+	if (unlikely(!sock->ops->splice_read))
+		return generic_file_splice_read(file, ppos, pipe, len, flags);
+
+	return sock->ops->splice_read(sock, ppos, pipe, len, flags);
+}
+
+static ssize_t sock_read_iter(struct kiocb *iocb, struct iov_iter *to)
+{
+	struct file *file = iocb->ki_filp;
+	struct socket *sock = file->private_data;
+	struct msghdr msg = {.msg_iter = *to,
+			     .msg_iocb = iocb};
+	ssize_t res;
+
+	if (file->f_flags & O_NONBLOCK || (iocb->ki_flags & IOCB_NOWAIT))
+		msg.msg_flags = MSG_DONTWAIT;
+
+	if (iocb->ki_pos != 0)
+		return -ESPIPE;
+
+	if (!iov_iter_count(to))	/* Match SYS5 behaviour */
+		return 0;
+
+	res = sock_recvmsg(sock, &msg, msg.msg_flags);
+	*to = msg.msg_iter;
+	return res;
+}
+
+static ssize_t sock_write_iter(struct kiocb *iocb, struct iov_iter *from)
+{
+	struct file *file = iocb->ki_filp;
+	struct socket *sock = file->private_data;
+	struct msghdr msg = {.msg_iter = *from,
+			     .msg_iocb = iocb};
+	ssize_t res;
+
+	if (iocb->ki_pos != 0)
+		return -ESPIPE;
+
+	if (file->f_flags & O_NONBLOCK || (iocb->ki_flags & IOCB_NOWAIT))
+		msg.msg_flags = MSG_DONTWAIT;
+
+	if (sock->type == SOCK_SEQPACKET)
+		msg.msg_flags |= MSG_EOR;
+
+	res = __sock_sendmsg(sock, &msg);
+	*from = msg.msg_iter;
+	return res;
+}
+
+/*
+ * Atomic setting of ioctl hooks to avoid race
+ * with module unload.
+ */
+
+static DEFINE_MUTEX(br_ioctl_mutex);
+static int (*br_ioctl_hook) (struct net *, unsigned int cmd, void __user *arg);
+
+void brioctl_set(int (*hook) (struct net *, unsigned int, void __user *))
+{
+	mutex_lock(&br_ioctl_mutex);
+	br_ioctl_hook = hook;
+	mutex_unlock(&br_ioctl_mutex);
+}
+EXPORT_SYMBOL(brioctl_set);
+
+static DEFINE_MUTEX(vlan_ioctl_mutex);
+static int (*vlan_ioctl_hook) (struct net *, void __user *arg);
+
+void vlan_ioctl_set(int (*hook) (struct net *, void __user *))
+{
+	mutex_lock(&vlan_ioctl_mutex);
+	vlan_ioctl_hook = hook;
+	mutex_unlock(&vlan_ioctl_mutex);
+}
+EXPORT_SYMBOL(vlan_ioctl_set);
+
+static DEFINE_MUTEX(dlci_ioctl_mutex);
+static int (*dlci_ioctl_hook) (unsigned int, void __user *);
+
+void dlci_ioctl_set(int (*hook) (unsigned int, void __user *))
+{
+	mutex_lock(&dlci_ioctl_mutex);
+	dlci_ioctl_hook = hook;
+	mutex_unlock(&dlci_ioctl_mutex);
+}
+EXPORT_SYMBOL(dlci_ioctl_set);
+
+static long sock_do_ioctl(struct net *net, struct socket *sock,
+			  unsigned int cmd, unsigned long arg)
+{
+	int err;
+	void __user *argp = (void __user *)arg;
+
+	err = sock->ops->ioctl(sock, cmd, arg);
+
+	/*
+	 * If this ioctl is unknown try to hand it down
+	 * to the NIC driver.
+	 */
+	if (err != -ENOIOCTLCMD)
+		return err;
+
+	if (cmd == SIOCGIFCONF) {
+		struct ifconf ifc;
+		if (copy_from_user(&ifc, argp, sizeof(struct ifconf)))
+			return -EFAULT;
+		rtnl_lock();
+		err = dev_ifconf(net, &ifc, sizeof(struct ifreq));
+		rtnl_unlock();
+		if (!err && copy_to_user(argp, &ifc, sizeof(struct ifconf)))
+			err = -EFAULT;
+	} else if (is_socket_ioctl_cmd(cmd)) {
+		struct ifreq ifr;
+		bool need_copyout;
+		if (copy_from_user(&ifr, argp, sizeof(struct ifreq)))
+			return -EFAULT;
+		err = dev_ioctl(net, cmd, &ifr, &need_copyout);
+		if (!err && need_copyout)
+			if (copy_to_user(argp, &ifr, sizeof(struct ifreq)))
+				return -EFAULT;
+	} else {
+		err = -ENOTTY;
+	}
+	return err;
+}
+
+/*
+ *	With an ioctl, arg may well be a user mode pointer, but we don't know
+ *	what to do with it - that's up to the protocol still.
+ */
+
+static long sock_ioctl(struct file *file, unsigned cmd, unsigned long arg)
+{
+	struct socket *sock;
+	struct sock *sk;
+	void __user *argp = (void __user *)arg;
+	int pid, err;
+	struct net *net;
+
+	sock = file->private_data;
+	sk = sock->sk;
+	net = sock_net(sk);
+	if (unlikely(cmd >= SIOCDEVPRIVATE && cmd <= (SIOCDEVPRIVATE + 15))) {
+		struct ifreq ifr;
+		bool need_copyout;
+		if (copy_from_user(&ifr, argp, sizeof(struct ifreq)))
+			return -EFAULT;
+		err = dev_ioctl(net, cmd, &ifr, &need_copyout);
+		if (!err && need_copyout)
+			if (copy_to_user(argp, &ifr, sizeof(struct ifreq)))
+				return -EFAULT;
+	} else
+#ifdef CONFIG_WEXT_CORE
+	if (cmd >= SIOCIWFIRST && cmd <= SIOCIWLAST) {
+		err = wext_handle_ioctl(net, cmd, argp);
+	} else
+#endif
+		switch (cmd) {
+		case FIOSETOWN:
+		case SIOCSPGRP:
+			err = -EFAULT;
+			if (get_user(pid, (int __user *)argp))
+				break;
+			err = f_setown(sock->file, pid, 1);
+			break;
+		case FIOGETOWN:
+		case SIOCGPGRP:
+			err = put_user(f_getown(sock->file),
+				       (int __user *)argp);
+			break;
+		case SIOCGIFBR:
+		case SIOCSIFBR:
+		case SIOCBRADDBR:
+		case SIOCBRDELBR:
+			err = -ENOPKG;
+			if (!br_ioctl_hook)
+				request_module("bridge");
+
+			mutex_lock(&br_ioctl_mutex);
+			if (br_ioctl_hook)
+				err = br_ioctl_hook(net, cmd, argp);
+			mutex_unlock(&br_ioctl_mutex);
+			break;
+		case SIOCGIFVLAN:
+		case SIOCSIFVLAN:
+			err = -ENOPKG;
+			if (!vlan_ioctl_hook)
+				request_module("8021q");
+
+			mutex_lock(&vlan_ioctl_mutex);
+			if (vlan_ioctl_hook)
+				err = vlan_ioctl_hook(net, argp);
+			mutex_unlock(&vlan_ioctl_mutex);
+			break;
+		case SIOCADDDLCI:
+		case SIOCDELDLCI:
+			err = -ENOPKG;
+			if (!dlci_ioctl_hook)
+				request_module("dlci");
+
+			mutex_lock(&dlci_ioctl_mutex);
+			if (dlci_ioctl_hook)
+				err = dlci_ioctl_hook(cmd, argp);
+			mutex_unlock(&dlci_ioctl_mutex);
+			break;
+		case SIOCGSKNS:
+			err = -EPERM;
+			if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
+				break;
+
+			err = open_related_ns(&net->ns, get_net_ns);
+			break;
+		case SIOCGSTAMP_OLD:
+		case SIOCGSTAMPNS_OLD:
+			if (!sock->ops->gettstamp) {
+				err = -ENOIOCTLCMD;
+				break;
+			}
+			err = sock->ops->gettstamp(sock, argp,
+						   cmd == SIOCGSTAMP_OLD,
+						   !IS_ENABLED(CONFIG_64BIT));
+			break;
+		case SIOCGSTAMP_NEW:
+		case SIOCGSTAMPNS_NEW:
+			if (!sock->ops->gettstamp) {
+				err = -ENOIOCTLCMD;
+				break;
+			}
+			err = sock->ops->gettstamp(sock, argp,
+						   cmd == SIOCGSTAMP_NEW,
+						   false);
+			break;
+		default:
+			err = sock_do_ioctl(net, sock, cmd, arg);
+			break;
+		}
+	return err;
+}
+
+/**
+ *	sock_create_lite - creates a socket
+ *	@family: protocol family (AF_INET, ...)
+ *	@type: communication type (SOCK_STREAM, ...)
+ *	@protocol: protocol (0, ...)
+ *	@res: new socket
+ *
+ *	Creates a new socket and assigns it to @res, passing through LSM.
+ *	The new socket initialization is not complete, see kernel_accept().
+ *	Returns 0 or an error. On failure @res is set to %NULL.
+ *	This function internally uses GFP_KERNEL.
+ */
+
+int sock_create_lite(int family, int type, int protocol, struct socket **res)
+{
+	int err;
+	struct socket *sock = NULL;
+
+	err = security_socket_create(family, type, protocol, 1);
+	if (err)
+		goto out;
+
+	sock = sock_alloc();
+	if (!sock) {
+		err = -ENOMEM;
+		goto out;
+	}
+
+	sock->type = type;
+	err = security_socket_post_create(sock, family, type, protocol, 1);
+	if (err)
+		goto out_release;
+
+out:
+	*res = sock;
+	return err;
+out_release:
+	sock_release(sock);
+	sock = NULL;
+	goto out;
+}
+EXPORT_SYMBOL(sock_create_lite);
+
+/* No kernel lock held - perfect */
+static __poll_t sock_poll(struct file *file, poll_table *wait)
+{
+	struct socket *sock = file->private_data;
+	__poll_t events = poll_requested_events(wait), flag = 0;
+
+	if (!sock->ops->poll)
+		return 0;
+
+	if (sk_can_busy_loop(sock->sk)) {
+		/* poll once if requested by the syscall */
+		if (events & POLL_BUSY_LOOP)
+			sk_busy_loop(sock->sk, 1);
+
+		/* if this socket can poll_ll, tell the system call */
+		flag = POLL_BUSY_LOOP;
+	}
+
+	return sock->ops->poll(file, sock, wait) | flag;
+}
+
+static int sock_mmap(struct file *file, struct vm_area_struct *vma)
+{
+	struct socket *sock = file->private_data;
+
+	return sock->ops->mmap(file, sock, vma);
+}
+
+static int sock_close(struct inode *inode, struct file *filp)
+{
+	__sock_release(SOCKET_I(inode), inode);
+	return 0;
+}
+
+/*
+ *	Update the socket async list
+ *
+ *	Fasync_list locking strategy.
+ *
+ *	1. fasync_list is modified only under process context socket lock
+ *	   i.e. under semaphore.
+ *	2. fasync_list is used under read_lock(&sk->sk_callback_lock)
+ *	   or under socket lock
+ */
+
+static int sock_fasync(int fd, struct file *filp, int on)
+{
+	struct socket *sock = filp->private_data;
+	struct sock *sk = sock->sk;
+	struct socket_wq *wq = &sock->wq;
+
+	if (sk == NULL)
+		return -EINVAL;
+
+	lock_sock(sk);
+	fasync_helper(fd, filp, on, &wq->fasync_list);
+
+	if (!wq->fasync_list)
+		sock_reset_flag(sk, SOCK_FASYNC);
+	else
+		sock_set_flag(sk, SOCK_FASYNC);
+
+	release_sock(sk);
+	return 0;
+}
+
+/* This function may be called only under rcu_lock */
+
+int sock_wake_async(struct socket_wq *wq, int how, int band)
+{
+	if (!wq || !wq->fasync_list)
+		return -1;
+
+	switch (how) {
+	case SOCK_WAKE_WAITD:
+		if (test_bit(SOCKWQ_ASYNC_WAITDATA, &wq->flags))
+			break;
+		goto call_kill;
+	case SOCK_WAKE_SPACE:
+		if (!test_and_clear_bit(SOCKWQ_ASYNC_NOSPACE, &wq->flags))
+			break;
+		fallthrough;
+	case SOCK_WAKE_IO:
+call_kill:
+		kill_fasync(&wq->fasync_list, SIGIO, band);
+		break;
+	case SOCK_WAKE_URG:
+		kill_fasync(&wq->fasync_list, SIGURG, band);
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL(sock_wake_async);
+
+/**
+ *	__sock_create - creates a socket
+ *	@net: net namespace
+ *	@family: protocol family (AF_INET, ...)
+ *	@type: communication type (SOCK_STREAM, ...)
+ *	@protocol: protocol (0, ...)
+ *	@res: new socket
+ *	@kern: boolean for kernel space sockets
+ *
+ *	Creates a new socket and assigns it to @res, passing through LSM.
+ *	Returns 0 or an error. On failure @res is set to %NULL. @kern must
+ *	be set to true if the socket resides in kernel space.
+ *	This function internally uses GFP_KERNEL.
+ */
+
+int __sock_create(struct net *net, int family, int type, int protocol,
+			 struct socket **res, int kern)
+{
+	int err;
+	struct socket *sock;
+	const struct net_proto_family *pf;
+
+	/*
+	 *      Check protocol is in range
+	 */
+	if (family < 0 || family >= NPROTO)
+		return -EAFNOSUPPORT;
+	if (type < 0 || type >= SOCK_MAX)
+		return -EINVAL;
+
+	/* Compatibility.
+
+	   This uglymoron is moved from INET layer to here to avoid
+	   deadlock in module load.
+	 */
+	if (family == PF_INET && type == SOCK_PACKET) {
+		pr_info_once("%s uses obsolete (PF_INET,SOCK_PACKET)\n",
+			     current->comm);
+		family = PF_PACKET;
+	}
+
+	err = security_socket_create(family, type, protocol, kern);
+	if (err)
+		return err;
+
+	/*
+	 *	Allocate the socket and allow the family to set things up. if
+	 *	the protocol is 0, the family is instructed to select an appropriate
+	 *	default.
+	 */
+	sock = sock_alloc();
+	if (!sock) {
+		net_warn_ratelimited("socket: no more sockets\n");
+		return -ENFILE;	/* Not exactly a match, but its the
+				   closest posix thing */
+	}
+
+	sock->type = type;
+
+#ifdef CONFIG_MODULES
+	/* Attempt to load a protocol module if the find failed.
+	 *
+	 * 12/09/1996 Marcin: But! this makes REALLY only sense, if the user
+	 * requested real, full-featured networking support upon configuration.
+	 * Otherwise module support will break!
+	 */
+	if (rcu_access_pointer(net_families[family]) == NULL)
+		request_module("net-pf-%d", family);
+#endif
+
+	rcu_read_lock();
+	pf = rcu_dereference(net_families[family]);
+	err = -EAFNOSUPPORT;
+	if (!pf)
+		goto out_release;
+
+	/*
+	 * We will call the ->create function, that possibly is in a loadable
+	 * module, so we have to bump that loadable module refcnt first.
+	 */
+	if (!try_module_get(pf->owner))
+		goto out_release;
+
+	/* Now protected by module ref count */
+	rcu_read_unlock();
+
+	err = pf->create(net, sock, protocol, kern);
+	if (err < 0)
+		goto out_module_put;
+
+	/*
+	 * Now to bump the refcnt of the [loadable] module that owns this
+	 * socket at sock_release time we decrement its refcnt.
+	 */
+	if (!try_module_get(sock->ops->owner))
+		goto out_module_busy;
+
+	/*
+	 * Now that we're done with the ->create function, the [loadable]
+	 * module can have its refcnt decremented
+	 */
+	module_put(pf->owner);
+	err = security_socket_post_create(sock, family, type, protocol, kern);
+	if (err)
+		goto out_sock_release;
+	*res = sock;
+
+	return 0;
+
+out_module_busy:
+	err = -EAFNOSUPPORT;
+out_module_put:
+	sock->ops = NULL;
+	module_put(pf->owner);
+out_sock_release:
+	sock_release(sock);
+	return err;
+
+out_release:
+	rcu_read_unlock();
+	goto out_sock_release;
+}
+EXPORT_SYMBOL(__sock_create);
+
+/**
+ *	sock_create - creates a socket
+ *	@family: protocol family (AF_INET, ...)
+ *	@type: communication type (SOCK_STREAM, ...)
+ *	@protocol: protocol (0, ...)
+ *	@res: new socket
+ *
+ *	A wrapper around __sock_create().
+ *	Returns 0 or an error. This function internally uses GFP_KERNEL.
+ */
+
+int sock_create(int family, int type, int protocol, struct socket **res)
+{
+	return __sock_create(current->nsproxy->net_ns, family, type, protocol, res, 0);
+}
+EXPORT_SYMBOL(sock_create);
+
+/**
+ *	sock_create_kern - creates a socket (kernel space)
+ *	@net: net namespace
+ *	@family: protocol family (AF_INET, ...)
+ *	@type: communication type (SOCK_STREAM, ...)
+ *	@protocol: protocol (0, ...)
+ *	@res: new socket
+ *
+ *	A wrapper around __sock_create().
+ *	Returns 0 or an error. This function internally uses GFP_KERNEL.
+ */
+
+int sock_create_kern(struct net *net, int family, int type, int protocol, struct socket **res)
+{
+	return __sock_create(net, family, type, protocol, res, 1);
+}
+EXPORT_SYMBOL(sock_create_kern);
+
+int __sys_socket(int family, int type, int protocol)
+{
+	int retval;
+	struct socket *sock;
+	int flags;
+
+	/* Check the SOCK_* constants for consistency.  */
+	BUILD_BUG_ON(SOCK_CLOEXEC != O_CLOEXEC);
+	BUILD_BUG_ON((SOCK_MAX | SOCK_TYPE_MASK) != SOCK_TYPE_MASK);
+	BUILD_BUG_ON(SOCK_CLOEXEC & SOCK_TYPE_MASK);
+	BUILD_BUG_ON(SOCK_NONBLOCK & SOCK_TYPE_MASK);
+
+	flags = type & ~SOCK_TYPE_MASK;
+	if (flags & ~(SOCK_CLOEXEC | SOCK_NONBLOCK))
+		return -EINVAL;
+	type &= SOCK_TYPE_MASK;
+
+	if (SOCK_NONBLOCK != O_NONBLOCK && (flags & SOCK_NONBLOCK))
+		flags = (flags & ~SOCK_NONBLOCK) | O_NONBLOCK;
+
+	retval = sock_create(family, type, protocol, &sock);
+	if (retval < 0)
+		return retval;
+
+	return sock_map_fd(sock, flags & (O_CLOEXEC | O_NONBLOCK));
+}
+
+SYSCALL_DEFINE3(socket, int, family, int, type, int, protocol)
+{
+	return __sys_socket(family, type, protocol);
+}
+
+/*
+ *	Create a pair of connected sockets.
+ */
+
+int __sys_socketpair(int family, int type, int protocol, int __user *usockvec)
+{
+	struct socket *sock1, *sock2;
+	int fd1, fd2, err;
+	struct file *newfile1, *newfile2;
+	int flags;
+
+	flags = type & ~SOCK_TYPE_MASK;
+	if (flags & ~(SOCK_CLOEXEC | SOCK_NONBLOCK))
+		return -EINVAL;
+	type &= SOCK_TYPE_MASK;
+
+	if (SOCK_NONBLOCK != O_NONBLOCK && (flags & SOCK_NONBLOCK))
+		flags = (flags & ~SOCK_NONBLOCK) | O_NONBLOCK;
+
+	/*
+	 * reserve descriptors and make sure we won't fail
+	 * to return them to userland.
+	 */
+	fd1 = get_unused_fd_flags(flags);
+	if (unlikely(fd1 < 0))
+		return fd1;
+
+	fd2 = get_unused_fd_flags(flags);
+	if (unlikely(fd2 < 0)) {
+		put_unused_fd(fd1);
+		return fd2;
+	}
+
+	err = put_user(fd1, &usockvec[0]);
+	if (err)
+		goto out;
+
+	err = put_user(fd2, &usockvec[1]);
+	if (err)
+		goto out;
+
+	/*
+	 * Obtain the first socket and check if the underlying protocol
+	 * supports the socketpair call.
+	 */
+
+	err = sock_create(family, type, protocol, &sock1);
+	if (unlikely(err < 0))
+		goto out;
+
+	err = sock_create(family, type, protocol, &sock2);
+	if (unlikely(err < 0)) {
+		sock_release(sock1);
+		goto out;
+	}
+
+	err = security_socket_socketpair(sock1, sock2);
+	if (unlikely(err)) {
+		sock_release(sock2);
+		sock_release(sock1);
+		goto out;
+	}
+
+	err = sock1->ops->socketpair(sock1, sock2);
+	if (unlikely(err < 0)) {
+		sock_release(sock2);
+		sock_release(sock1);
+		goto out;
+	}
+
+	newfile1 = sock_alloc_file(sock1, flags, NULL);
+	if (IS_ERR(newfile1)) {
+		err = PTR_ERR(newfile1);
+		sock_release(sock2);
+		goto out;
+	}
+
+	newfile2 = sock_alloc_file(sock2, flags, NULL);
+	if (IS_ERR(newfile2)) {
+		err = PTR_ERR(newfile2);
+		fput(newfile1);
+		goto out;
+	}
+
+	audit_fd_pair(fd1, fd2);
+
+	fd_install(fd1, newfile1);
+	fd_install(fd2, newfile2);
+	return 0;
+
+out:
+	put_unused_fd(fd2);
+	put_unused_fd(fd1);
+	return err;
+}
+
+SYSCALL_DEFINE4(socketpair, int, family, int, type, int, protocol,
+		int __user *, usockvec)
+{
+	return __sys_socketpair(family, type, protocol, usockvec);
+}
+
+/*
+ *	Bind a name to a socket. Nothing much to do here since it's
+ *	the protocol's responsibility to handle the local address.
+ *
+ *	We move the socket address to kernel space before we call
+ *	the protocol layer (having also checked the address is ok).
+ */
+
+int __sys_bind(int fd, struct sockaddr __user *umyaddr, int addrlen)
+{
+	struct socket *sock;
+	struct sockaddr_storage address;
+	int err, fput_needed;
+
+	sock = sockfd_lookup_light(fd, &err, &fput_needed);
+	if (sock) {
+		err = move_addr_to_kernel(umyaddr, addrlen, &address);
+		if (!err) {
+			err = security_socket_bind(sock,
+						   (struct sockaddr *)&address,
+						   addrlen);
+			if (!err)
+				err = sock->ops->bind(sock,
+						      (struct sockaddr *)
+						      &address, addrlen);
+		}
+		fput_light(sock->file, fput_needed);
+	}
+	return err;
+}
+
+SYSCALL_DEFINE3(bind, int, fd, struct sockaddr __user *, umyaddr, int, addrlen)
+{
+	return __sys_bind(fd, umyaddr, addrlen);
+}
+
+/*
+ *	Perform a listen. Basically, we allow the protocol to do anything
+ *	necessary for a listen, and if that works, we mark the socket as
+ *	ready for listening.
+ */
+
+int __sys_listen(int fd, int backlog)
+{
+	struct socket *sock;
+	int err, fput_needed;
+	int somaxconn;
+
+	sock = sockfd_lookup_light(fd, &err, &fput_needed);
+	if (sock) {
+		somaxconn = READ_ONCE(sock_net(sock->sk)->core.sysctl_somaxconn);
+		if ((unsigned int)backlog > somaxconn)
+			backlog = somaxconn;
+
+		err = security_socket_listen(sock, backlog);
+		if (!err)
+			err = sock->ops->listen(sock, backlog);
+
+		fput_light(sock->file, fput_needed);
+	}
+	return err;
+}
+
+SYSCALL_DEFINE2(listen, int, fd, int, backlog)
+{
+	return __sys_listen(fd, backlog);
+}
+
+struct file *do_accept(struct file *file, unsigned file_flags,
+		       struct sockaddr __user *upeer_sockaddr,
+		       int __user *upeer_addrlen, int flags)
+{
+	struct socket *sock, *newsock;
+	struct file *newfile;
+	int err, len;
+	struct sockaddr_storage address;
+
+	sock = sock_from_file(file, &err);
+	if (!sock)
+		return ERR_PTR(err);
+
+	newsock = sock_alloc();
+	if (!newsock)
+		return ERR_PTR(-ENFILE);
+
+	newsock->type = sock->type;
+	newsock->ops = sock->ops;
+
+	/*
+	 * We don't need try_module_get here, as the listening socket (sock)
+	 * has the protocol module (sock->ops->owner) held.
+	 */
+	__module_get(newsock->ops->owner);
+
+	newfile = sock_alloc_file(newsock, flags, sock->sk->sk_prot_creator->name);
+	if (IS_ERR(newfile))
+		return newfile;
+
+	err = security_socket_accept(sock, newsock);
+	if (err)
+		goto out_fd;
+
+	err = sock->ops->accept(sock, newsock, sock->file->f_flags | file_flags,
+					false);
+	if (err < 0)
+		goto out_fd;
+
+	if (upeer_sockaddr) {
+		len = newsock->ops->getname(newsock,
+					(struct sockaddr *)&address, 2);
+		if (len < 0) {
+			err = -ECONNABORTED;
+			goto out_fd;
+		}
+		err = move_addr_to_user(&address,
+					len, upeer_sockaddr, upeer_addrlen);
+		if (err < 0)
+			goto out_fd;
+	}
+
+	/* File flags are not inherited via accept() unlike another OSes. */
+	return newfile;
+out_fd:
+	fput(newfile);
+	return ERR_PTR(err);
+}
+
+int __sys_accept4_file(struct file *file, unsigned file_flags,
+		       struct sockaddr __user *upeer_sockaddr,
+		       int __user *upeer_addrlen, int flags,
+		       unsigned long nofile)
+{
+	struct file *newfile;
+	int newfd;
+
+	if (flags & ~(SOCK_CLOEXEC | SOCK_NONBLOCK))
+		return -EINVAL;
+
+	if (SOCK_NONBLOCK != O_NONBLOCK && (flags & SOCK_NONBLOCK))
+		flags = (flags & ~SOCK_NONBLOCK) | O_NONBLOCK;
+
+	newfd = __get_unused_fd_flags(flags, nofile);
+	if (unlikely(newfd < 0))
+		return newfd;
+
+	newfile = do_accept(file, file_flags, upeer_sockaddr, upeer_addrlen,
+			    flags);
+	if (IS_ERR(newfile)) {
+		put_unused_fd(newfd);
+		return PTR_ERR(newfile);
+	}
+	fd_install(newfd, newfile);
+	return newfd;
+}
+
+/*
+ *	For accept, we attempt to create a new socket, set up the link
+ *	with the client, wake up the client, then return the new
+ *	connected fd. We collect the address of the connector in kernel
+ *	space and move it to user at the very end. This is unclean because
+ *	we open the socket then return an error.
+ *
+ *	1003.1g adds the ability to recvmsg() to query connection pending
+ *	status to recvmsg. We need to add that support in a way thats
+ *	clean when we restructure accept also.
+ */
+
+int __sys_accept4(int fd, struct sockaddr __user *upeer_sockaddr,
+		  int __user *upeer_addrlen, int flags)
+{
+	int ret = -EBADF;
+	struct fd f;
+
+	f = fdget(fd);
+	if (f.file) {
+		ret = __sys_accept4_file(f.file, 0, upeer_sockaddr,
+						upeer_addrlen, flags,
+						rlimit(RLIMIT_NOFILE));
+		fdput(f);
+	}
+
+	return ret;
+}
+
+SYSCALL_DEFINE4(accept4, int, fd, struct sockaddr __user *, upeer_sockaddr,
+		int __user *, upeer_addrlen, int, flags)
+{
+	return __sys_accept4(fd, upeer_sockaddr, upeer_addrlen, flags);
+}
+
+SYSCALL_DEFINE3(accept, int, fd, struct sockaddr __user *, upeer_sockaddr,
+		int __user *, upeer_addrlen)
+{
+	return __sys_accept4(fd, upeer_sockaddr, upeer_addrlen, 0);
+}
+
+/*
+ *	Attempt to connect to a socket with the server address.  The address
+ *	is in user space so we verify it is OK and move it to kernel space.
+ *
+ *	For 1003.1g we need to add clean support for a bind to AF_UNSPEC to
+ *	break bindings
+ *
+ *	NOTE: 1003.1g draft 6.3 is broken with respect to AX.25/NetROM and
+ *	other SEQPACKET protocols that take time to connect() as it doesn't
+ *	include the -EINPROGRESS status for such sockets.
+ */
+
+int __sys_connect_file(struct file *file, struct sockaddr_storage *address,
+		       int addrlen, int file_flags)
+{
+	struct socket *sock;
+	int err;
+
+	sock = sock_from_file(file, &err);
+	if (!sock)
+		goto out;
+
+	err =
+	    security_socket_connect(sock, (struct sockaddr *)address, addrlen);
+	if (err)
+		goto out;
+
+	err = sock->ops->connect(sock, (struct sockaddr *)address, addrlen,
+				 sock->file->f_flags | file_flags);
+out:
+	return err;
+}
+
+int __sys_connect(int fd, struct sockaddr __user *uservaddr, int addrlen)
+{
+	int ret = -EBADF;
+	struct fd f;
+
+	f = fdget(fd);
+	if (f.file) {
+		struct sockaddr_storage address;
+
+		ret = move_addr_to_kernel(uservaddr, addrlen, &address);
+		if (!ret)
+			ret = __sys_connect_file(f.file, &address, addrlen, 0);
+		fdput(f);
+	}
+
+	return ret;
+}
+
+SYSCALL_DEFINE3(connect, int, fd, struct sockaddr __user *, uservaddr,
+		int, addrlen)
+{
+	return __sys_connect(fd, uservaddr, addrlen);
+}
+
+/*
+ *	Get the local address ('name') of a socket object. Move the obtained
+ *	name to user space.
+ */
+
+int __sys_getsockname(int fd, struct sockaddr __user *usockaddr,
+		      int __user *usockaddr_len)
+{
+	struct socket *sock;
+	struct sockaddr_storage address;
+	int err, fput_needed;
+
+	sock = sockfd_lookup_light(fd, &err, &fput_needed);
+	if (!sock)
+		goto out;
+
+	err = security_socket_getsockname(sock);
+	if (err)
+		goto out_put;
+
+	err = sock->ops->getname(sock, (struct sockaddr *)&address, 0);
+	if (err < 0)
+		goto out_put;
+        /* "err" is actually length in this case */
+	err = move_addr_to_user(&address, err, usockaddr, usockaddr_len);
+
+out_put:
+	fput_light(sock->file, fput_needed);
+out:
+	return err;
+}
+
+SYSCALL_DEFINE3(getsockname, int, fd, struct sockaddr __user *, usockaddr,
+		int __user *, usockaddr_len)
+{
+	return __sys_getsockname(fd, usockaddr, usockaddr_len);
+}
+
+/*
+ *	Get the remote address ('name') of a socket object. Move the obtained
+ *	name to user space.
+ */
+
+int __sys_getpeername(int fd, struct sockaddr __user *usockaddr,
+		      int __user *usockaddr_len)
+{
+	struct socket *sock;
+	struct sockaddr_storage address;
+	int err, fput_needed;
+
+	sock = sockfd_lookup_light(fd, &err, &fput_needed);
+	if (sock != NULL) {
+		err = security_socket_getpeername(sock);
+		if (err) {
+			fput_light(sock->file, fput_needed);
+			return err;
+		}
+
+		err = sock->ops->getname(sock, (struct sockaddr *)&address, 1);
+		if (err >= 0)
+			/* "err" is actually length in this case */
+			err = move_addr_to_user(&address, err, usockaddr,
+						usockaddr_len);
+		fput_light(sock->file, fput_needed);
+	}
+	return err;
+}
+
+SYSCALL_DEFINE3(getpeername, int, fd, struct sockaddr __user *, usockaddr,
+		int __user *, usockaddr_len)
+{
+	return __sys_getpeername(fd, usockaddr, usockaddr_len);
+}
+
+/*
+ *	Send a datagram to a given address. We move the address into kernel
+ *	space and check the user space data area is readable before invoking
+ *	the protocol.
+ */
+int __sys_sendto(int fd, void __user *buff, size_t len, unsigned int flags,
+		 struct sockaddr __user *addr,  int addr_len)
+{
+	struct socket *sock;
+	struct sockaddr_storage address;
+	int err;
+	struct msghdr msg;
+	struct iovec iov;
+	int fput_needed;
+
+	err = import_single_range(WRITE, buff, len, &iov, &msg.msg_iter);
+	if (unlikely(err))
+		return err;
+	sock = sockfd_lookup_light(fd, &err, &fput_needed);
+	if (!sock)
+		goto out;
+
+	msg.msg_name = NULL;
+	msg.msg_control = NULL;
+	msg.msg_controllen = 0;
+	msg.msg_namelen = 0;
+	if (addr) {
+		err = move_addr_to_kernel(addr, addr_len, &address);
+		if (err < 0)
+			goto out_put;
+		msg.msg_name = (struct sockaddr *)&address;
+		msg.msg_namelen = addr_len;
+	}
+	if (sock->file->f_flags & O_NONBLOCK)
+		flags |= MSG_DONTWAIT;
+	msg.msg_flags = flags;
+	err = __sock_sendmsg(sock, &msg);
+
+out_put:
+	fput_light(sock->file, fput_needed);
+out:
+	return err;
+}
+
+SYSCALL_DEFINE6(sendto, int, fd, void __user *, buff, size_t, len,
+		unsigned int, flags, struct sockaddr __user *, addr,
+		int, addr_len)
+{
+	return __sys_sendto(fd, buff, len, flags, addr, addr_len);
+}
+
+/*
+ *	Send a datagram down a socket.
+ */
+
+SYSCALL_DEFINE4(send, int, fd, void __user *, buff, size_t, len,
+		unsigned int, flags)
+{
+	return __sys_sendto(fd, buff, len, flags, NULL, 0);
+}
+
+/*
+ *	Receive a frame from the socket and optionally record the address of the
+ *	sender. We verify the buffers are writable and if needed move the
+ *	sender address from kernel to user space.
+ */
+int __sys_recvfrom(int fd, void __user *ubuf, size_t size, unsigned int flags,
+		   struct sockaddr __user *addr, int __user *addr_len)
+{
+	struct socket *sock;
+	struct iovec iov;
+	struct msghdr msg;
+	struct sockaddr_storage address;
+	int err, err2;
+	int fput_needed;
+
+	err = import_single_range(READ, ubuf, size, &iov, &msg.msg_iter);
+	if (unlikely(err))
+		return err;
+	sock = sockfd_lookup_light(fd, &err, &fput_needed);
+	if (!sock)
+		goto out;
+
+	msg.msg_control = NULL;
+	msg.msg_controllen = 0;
+	/* Save some cycles and don't copy the address if not needed */
+	msg.msg_name = addr ? (struct sockaddr *)&address : NULL;
+	/* We assume all kernel code knows the size of sockaddr_storage */
+	msg.msg_namelen = 0;
+	msg.msg_iocb = NULL;
+	msg.msg_flags = 0;
+	if (sock->file->f_flags & O_NONBLOCK)
+		flags |= MSG_DONTWAIT;
+	err = sock_recvmsg(sock, &msg, flags);
+
+	if (err >= 0 && addr != NULL) {
+		err2 = move_addr_to_user(&address,
+					 msg.msg_namelen, addr, addr_len);
+		if (err2 < 0)
+			err = err2;
+	}
+
+	fput_light(sock->file, fput_needed);
+out:
+	return err;
+}
+
+SYSCALL_DEFINE6(recvfrom, int, fd, void __user *, ubuf, size_t, size,
+		unsigned int, flags, struct sockaddr __user *, addr,
+		int __user *, addr_len)
+{
+	return __sys_recvfrom(fd, ubuf, size, flags, addr, addr_len);
+}
+
+/*
+ *	Receive a datagram from a socket.
+ */
+
+SYSCALL_DEFINE4(recv, int, fd, void __user *, ubuf, size_t, size,
+		unsigned int, flags)
+{
+	return __sys_recvfrom(fd, ubuf, size, flags, NULL, NULL);
+}
+
+static bool sock_use_custom_sol_socket(const struct socket *sock)
+{
+	const struct sock *sk = sock->sk;
+
+	/* Use sock->ops->setsockopt() for MPTCP */
+	return IS_ENABLED(CONFIG_MPTCP) &&
+	       sk->sk_protocol == IPPROTO_MPTCP &&
+	       sk->sk_type == SOCK_STREAM &&
+	       (sk->sk_family == AF_INET || sk->sk_family == AF_INET6);
+}
+
+/*
+ *	Set a socket option. Because we don't know the option lengths we have
+ *	to pass the user mode parameter for the protocols to sort out.
+ */
+int __sys_setsockopt(int fd, int level, int optname, char __user *user_optval,
+		int optlen)
+{
+	sockptr_t optval = USER_SOCKPTR(user_optval);
+	char *kernel_optval = NULL;
+	int err, fput_needed;
+	struct socket *sock;
+
+	if (optlen < 0)
+		return -EINVAL;
+
+	sock = sockfd_lookup_light(fd, &err, &fput_needed);
+	if (!sock)
+		return err;
+
+	err = security_socket_setsockopt(sock, level, optname);
+	if (err)
+		goto out_put;
+
+	if (!in_compat_syscall())
+		err = BPF_CGROUP_RUN_PROG_SETSOCKOPT(sock->sk, &level, &optname,
+						     user_optval, &optlen,
+						     &kernel_optval);
+	if (err < 0)
+		goto out_put;
+	if (err > 0) {
+		err = 0;
+		goto out_put;
+	}
+
+	if (kernel_optval)
+		optval = KERNEL_SOCKPTR(kernel_optval);
+	if (level == SOL_SOCKET && !sock_use_custom_sol_socket(sock))
+		err = sock_setsockopt(sock, level, optname, optval, optlen);
+	else if (unlikely(!sock->ops->setsockopt))
+		err = -EOPNOTSUPP;
+	else
+		err = sock->ops->setsockopt(sock, level, optname, optval,
+					    optlen);
+	kfree(kernel_optval);
+out_put:
+	fput_light(sock->file, fput_needed);
+	return err;
+}
+
+SYSCALL_DEFINE5(setsockopt, int, fd, int, level, int, optname,
+		char __user *, optval, int, optlen)
+{
+	return __sys_setsockopt(fd, level, optname, optval, optlen);
+}
+
+INDIRECT_CALLABLE_DECLARE(bool tcp_bpf_bypass_getsockopt(int level,
+							 int optname));
+
+/*
+ *	Get a socket option. Because we don't know the option lengths we have
+ *	to pass a user mode parameter for the protocols to sort out.
+ */
+int __sys_getsockopt(int fd, int level, int optname, char __user *optval,
+		int __user *optlen)
+{
+	int err, fput_needed;
+	struct socket *sock;
+	int max_optlen;
+
+	sock = sockfd_lookup_light(fd, &err, &fput_needed);
+	if (!sock)
+		return err;
+
+	err = security_socket_getsockopt(sock, level, optname);
+	if (err)
+		goto out_put;
+
+	if (!in_compat_syscall())
+		max_optlen = BPF_CGROUP_GETSOCKOPT_MAX_OPTLEN(optlen);
+
+	if (level == SOL_SOCKET)
+		err = sock_getsockopt(sock, level, optname, optval, optlen);
+	else if (unlikely(!sock->ops->getsockopt))
+		err = -EOPNOTSUPP;
+	else
+		err = sock->ops->getsockopt(sock, level, optname, optval,
+					    optlen);
+
+	if (!in_compat_syscall())
+		err = BPF_CGROUP_RUN_PROG_GETSOCKOPT(sock->sk, level, optname,
+						     optval, optlen, max_optlen,
+						     err);
+out_put:
+	fput_light(sock->file, fput_needed);
+	return err;
+}
+
+SYSCALL_DEFINE5(getsockopt, int, fd, int, level, int, optname,
+		char __user *, optval, int __user *, optlen)
+{
+	return __sys_getsockopt(fd, level, optname, optval, optlen);
+}
+
+/*
+ *	Shutdown a socket.
+ */
+
+int __sys_shutdown_sock(struct socket *sock, int how)
+{
+	int err;
+
+	err = security_socket_shutdown(sock, how);
+	if (!err)
+		err = sock->ops->shutdown(sock, how);
+
+	return err;
+}
+
+int __sys_shutdown(int fd, int how)
+{
+	int err, fput_needed;
+	struct socket *sock;
+
+	sock = sockfd_lookup_light(fd, &err, &fput_needed);
+	if (sock != NULL) {
+		err = __sys_shutdown_sock(sock, how);
+		fput_light(sock->file, fput_needed);
+	}
+	return err;
+}
+
+SYSCALL_DEFINE2(shutdown, int, fd, int, how)
+{
+	return __sys_shutdown(fd, how);
+}
+
+/* A couple of helpful macros for getting the address of the 32/64 bit
+ * fields which are the same type (int / unsigned) on our platforms.
+ */
+#define COMPAT_MSG(msg, member)	((MSG_CMSG_COMPAT & flags) ? &msg##_compat->member : &msg->member)
+#define COMPAT_NAMELEN(msg)	COMPAT_MSG(msg, msg_namelen)
+#define COMPAT_FLAGS(msg)	COMPAT_MSG(msg, msg_flags)
+
+struct used_address {
+	struct sockaddr_storage name;
+	unsigned int name_len;
+};
+
+int __copy_msghdr_from_user(struct msghdr *kmsg,
+			    struct user_msghdr __user *umsg,
+			    struct sockaddr __user **save_addr,
+			    struct iovec __user **uiov, size_t *nsegs)
+{
+	struct user_msghdr msg;
+	ssize_t err;
+
+	if (copy_from_user(&msg, umsg, sizeof(*umsg)))
+		return -EFAULT;
+
+	kmsg->msg_control_is_user = true;
+	kmsg->msg_control_user = msg.msg_control;
+	kmsg->msg_controllen = msg.msg_controllen;
+	kmsg->msg_flags = msg.msg_flags;
+
+	kmsg->msg_namelen = msg.msg_namelen;
+	if (!msg.msg_name)
+		kmsg->msg_namelen = 0;
+
+	if (kmsg->msg_namelen < 0)
+		return -EINVAL;
+
+	if (kmsg->msg_namelen > sizeof(struct sockaddr_storage))
+		kmsg->msg_namelen = sizeof(struct sockaddr_storage);
+
+	if (save_addr)
+		*save_addr = msg.msg_name;
+
+	if (msg.msg_name && kmsg->msg_namelen) {
+		if (!save_addr) {
+			err = move_addr_to_kernel(msg.msg_name,
+						  kmsg->msg_namelen,
+						  kmsg->msg_name);
+			if (err < 0)
+				return err;
+		}
+	} else {
+		kmsg->msg_name = NULL;
+		kmsg->msg_namelen = 0;
+	}
+
+	if (msg.msg_iovlen > UIO_MAXIOV)
+		return -EMSGSIZE;
+
+	kmsg->msg_iocb = NULL;
+	*uiov = msg.msg_iov;
+	*nsegs = msg.msg_iovlen;
+	return 0;
+}
+
+static int copy_msghdr_from_user(struct msghdr *kmsg,
+				 struct user_msghdr __user *umsg,
+				 struct sockaddr __user **save_addr,
+				 struct iovec **iov)
+{
+	struct user_msghdr msg;
+	ssize_t err;
+
+	err = __copy_msghdr_from_user(kmsg, umsg, save_addr, &msg.msg_iov,
+					&msg.msg_iovlen);
+	if (err)
+		return err;
+
+	err = import_iovec(save_addr ? READ : WRITE,
+			    msg.msg_iov, msg.msg_iovlen,
+			    UIO_FASTIOV, iov, &kmsg->msg_iter);
+	return err < 0 ? err : 0;
+}
+
+static int ____sys_sendmsg(struct socket *sock, struct msghdr *msg_sys,
+			   unsigned int flags, struct used_address *used_address,
+			   unsigned int allowed_msghdr_flags)
+{
+	unsigned char ctl[sizeof(struct cmsghdr) + 20]
+				__aligned(sizeof(__kernel_size_t));
+	/* 20 is size of ipv6_pktinfo */
+	unsigned char *ctl_buf = ctl;
+	int ctl_len;
+	ssize_t err;
+
+	err = -ENOBUFS;
+
+	if (msg_sys->msg_controllen > INT_MAX)
+		goto out;
+	flags |= (msg_sys->msg_flags & allowed_msghdr_flags);
+	ctl_len = msg_sys->msg_controllen;
+	if ((MSG_CMSG_COMPAT & flags) && ctl_len) {
+		err =
+		    cmsghdr_from_user_compat_to_kern(msg_sys, sock->sk, ctl,
+						     sizeof(ctl));
+		if (err)
+			goto out;
+		ctl_buf = msg_sys->msg_control;
+		ctl_len = msg_sys->msg_controllen;
+	} else if (ctl_len) {
+		BUILD_BUG_ON(sizeof(struct cmsghdr) !=
+			     CMSG_ALIGN(sizeof(struct cmsghdr)));
+		if (ctl_len > sizeof(ctl)) {
+			ctl_buf = sock_kmalloc(sock->sk, ctl_len, GFP_KERNEL);
+			if (ctl_buf == NULL)
+				goto out;
+		}
+		err = -EFAULT;
+		if (copy_from_user(ctl_buf, msg_sys->msg_control_user, ctl_len))
+			goto out_freectl;
+		msg_sys->msg_control = ctl_buf;
+		msg_sys->msg_control_is_user = false;
+	}
+	msg_sys->msg_flags = flags;
+
+	if (sock->file->f_flags & O_NONBLOCK)
+		msg_sys->msg_flags |= MSG_DONTWAIT;
+	/*
+	 * If this is sendmmsg() and current destination address is same as
+	 * previously succeeded address, omit asking LSM's decision.
+	 * used_address->name_len is initialized to UINT_MAX so that the first
+	 * destination address never matches.
+	 */
+	if (used_address && msg_sys->msg_name &&
+	    used_address->name_len == msg_sys->msg_namelen &&
+	    !memcmp(&used_address->name, msg_sys->msg_name,
+		    used_address->name_len)) {
+		err = sock_sendmsg_nosec(sock, msg_sys);
+		goto out_freectl;
+	}
+	err = __sock_sendmsg(sock, msg_sys);
+	/*
+	 * If this is sendmmsg() and sending to current destination address was
+	 * successful, remember it.
+	 */
+	if (used_address && err >= 0) {
+		used_address->name_len = msg_sys->msg_namelen;
+		if (msg_sys->msg_name)
+			memcpy(&used_address->name, msg_sys->msg_name,
+			       used_address->name_len);
+	}
+
+out_freectl:
+	if (ctl_buf != ctl)
+		sock_kfree_s(sock->sk, ctl_buf, ctl_len);
+out:
+	return err;
+}
+
+int sendmsg_copy_msghdr(struct msghdr *msg,
+			struct user_msghdr __user *umsg, unsigned flags,
+			struct iovec **iov)
+{
+	int err;
+
+	if (flags & MSG_CMSG_COMPAT) {
+		struct compat_msghdr __user *msg_compat;
+
+		msg_compat = (struct compat_msghdr __user *) umsg;
+		err = get_compat_msghdr(msg, msg_compat, NULL, iov);
+	} else {
+		err = copy_msghdr_from_user(msg, umsg, NULL, iov);
+	}
+	if (err < 0)
+		return err;
+
+	return 0;
+}
+
+static int ___sys_sendmsg(struct socket *sock, struct user_msghdr __user *msg,
+			 struct msghdr *msg_sys, unsigned int flags,
+			 struct used_address *used_address,
+			 unsigned int allowed_msghdr_flags)
+{
+	struct sockaddr_storage address;
+	struct iovec iovstack[UIO_FASTIOV], *iov = iovstack;
+	ssize_t err;
+
+	msg_sys->msg_name = &address;
+
+	err = sendmsg_copy_msghdr(msg_sys, msg, flags, &iov);
+	if (err < 0)
+		return err;
+
+	err = ____sys_sendmsg(sock, msg_sys, flags, used_address,
+				allowed_msghdr_flags);
+	kfree(iov);
+	return err;
+}
+
+/*
+ *	BSD sendmsg interface
+ */
+long __sys_sendmsg_sock(struct socket *sock, struct msghdr *msg,
+			unsigned int flags)
+{
+	return ____sys_sendmsg(sock, msg, flags, NULL, 0);
+}
+
+long __sys_sendmsg(int fd, struct user_msghdr __user *msg, unsigned int flags,
+		   bool forbid_cmsg_compat)
+{
+	int fput_needed, err;
+	struct msghdr msg_sys;
+	struct socket *sock;
+
+	if (forbid_cmsg_compat && (flags & MSG_CMSG_COMPAT))
+		return -EINVAL;
+
+	sock = sockfd_lookup_light(fd, &err, &fput_needed);
+	if (!sock)
+		goto out;
+
+	err = ___sys_sendmsg(sock, msg, &msg_sys, flags, NULL, 0);
+
+	fput_light(sock->file, fput_needed);
+out:
+	return err;
+}
+
+SYSCALL_DEFINE3(sendmsg, int, fd, struct user_msghdr __user *, msg, unsigned int, flags)
+{
+	return __sys_sendmsg(fd, msg, flags, true);
+}
+
+/*
+ *	Linux sendmmsg interface
+ */
+
+int __sys_sendmmsg(int fd, struct mmsghdr __user *mmsg, unsigned int vlen,
+		   unsigned int flags, bool forbid_cmsg_compat)
+{
+	int fput_needed, err, datagrams;
+	struct socket *sock;
+	struct mmsghdr __user *entry;
+	struct compat_mmsghdr __user *compat_entry;
+	struct msghdr msg_sys;
+	struct used_address used_address;
+	unsigned int oflags = flags;
+
+	if (forbid_cmsg_compat && (flags & MSG_CMSG_COMPAT))
+		return -EINVAL;
+
+	if (vlen > UIO_MAXIOV)
+		vlen = UIO_MAXIOV;
+
+	datagrams = 0;
+
+	sock = sockfd_lookup_light(fd, &err, &fput_needed);
+	if (!sock)
+		return err;
+
+	used_address.name_len = UINT_MAX;
+	entry = mmsg;
+	compat_entry = (struct compat_mmsghdr __user *)mmsg;
+	err = 0;
+	flags |= MSG_BATCH;
+
+	while (datagrams < vlen) {
+		if (datagrams == vlen - 1)
+			flags = oflags;
+
+		if (MSG_CMSG_COMPAT & flags) {
+			err = ___sys_sendmsg(sock, (struct user_msghdr __user *)compat_entry,
+					     &msg_sys, flags, &used_address, MSG_EOR);
+			if (err < 0)
+				break;
+			err = __put_user(err, &compat_entry->msg_len);
+			++compat_entry;
+		} else {
+			err = ___sys_sendmsg(sock,
+					     (struct user_msghdr __user *)entry,
+					     &msg_sys, flags, &used_address, MSG_EOR);
+			if (err < 0)
+				break;
+			err = put_user(err, &entry->msg_len);
+			++entry;
+		}
+
+		if (err)
+			break;
+		++datagrams;
+		if (msg_data_left(&msg_sys))
+			break;
+		cond_resched();
+	}
+
+	fput_light(sock->file, fput_needed);
+
+	/* We only return an error if no datagrams were able to be sent */
+	if (datagrams != 0)
+		return datagrams;
+
+	return err;
+}
+
+SYSCALL_DEFINE4(sendmmsg, int, fd, struct mmsghdr __user *, mmsg,
+		unsigned int, vlen, unsigned int, flags)
+{
+	return __sys_sendmmsg(fd, mmsg, vlen, flags, true);
+}
+
+int recvmsg_copy_msghdr(struct msghdr *msg,
+			struct user_msghdr __user *umsg, unsigned flags,
+			struct sockaddr __user **uaddr,
+			struct iovec **iov)
+{
+	ssize_t err;
+
+	if (MSG_CMSG_COMPAT & flags) {
+		struct compat_msghdr __user *msg_compat;
+
+		msg_compat = (struct compat_msghdr __user *) umsg;
+		err = get_compat_msghdr(msg, msg_compat, uaddr, iov);
+	} else {
+		err = copy_msghdr_from_user(msg, umsg, uaddr, iov);
+	}
+	if (err < 0)
+		return err;
+
+	return 0;
+}
+
+static int ____sys_recvmsg(struct socket *sock, struct msghdr *msg_sys,
+			   struct user_msghdr __user *msg,
+			   struct sockaddr __user *uaddr,
+			   unsigned int flags, int nosec)
+{
+	struct compat_msghdr __user *msg_compat =
+					(struct compat_msghdr __user *) msg;
+	int __user *uaddr_len = COMPAT_NAMELEN(msg);
+	struct sockaddr_storage addr;
+	unsigned long cmsg_ptr;
+	int len;
+	ssize_t err;
+
+	msg_sys->msg_name = &addr;
+	cmsg_ptr = (unsigned long)msg_sys->msg_control;
+	msg_sys->msg_flags = flags & (MSG_CMSG_CLOEXEC|MSG_CMSG_COMPAT);
+
+	/* We assume all kernel code knows the size of sockaddr_storage */
+	msg_sys->msg_namelen = 0;
+
+	if (sock->file->f_flags & O_NONBLOCK)
+		flags |= MSG_DONTWAIT;
+
+	if (unlikely(nosec))
+		err = sock_recvmsg_nosec(sock, msg_sys, flags);
+	else
+		err = sock_recvmsg(sock, msg_sys, flags);
+
+	if (err < 0)
+		goto out;
+	len = err;
+
+	if (uaddr != NULL) {
+		err = move_addr_to_user(&addr,
+					msg_sys->msg_namelen, uaddr,
+					uaddr_len);
+		if (err < 0)
+			goto out;
+	}
+	err = __put_user((msg_sys->msg_flags & ~MSG_CMSG_COMPAT),
+			 COMPAT_FLAGS(msg));
+	if (err)
+		goto out;
+	if (MSG_CMSG_COMPAT & flags)
+		err = __put_user((unsigned long)msg_sys->msg_control - cmsg_ptr,
+				 &msg_compat->msg_controllen);
+	else
+		err = __put_user((unsigned long)msg_sys->msg_control - cmsg_ptr,
+				 &msg->msg_controllen);
+	if (err)
+		goto out;
+	err = len;
+out:
+	return err;
+}
+
+static int ___sys_recvmsg(struct socket *sock, struct user_msghdr __user *msg,
+			 struct msghdr *msg_sys, unsigned int flags, int nosec)
+{
+	struct iovec iovstack[UIO_FASTIOV], *iov = iovstack;
+	/* user mode address pointers */
+	struct sockaddr __user *uaddr;
+	ssize_t err;
+
+	err = recvmsg_copy_msghdr(msg_sys, msg, flags, &uaddr, &iov);
+	if (err < 0)
+		return err;
+
+	err = ____sys_recvmsg(sock, msg_sys, msg, uaddr, flags, nosec);
+	kfree(iov);
+	return err;
+}
+
+/*
+ *	BSD recvmsg interface
+ */
+
+long __sys_recvmsg_sock(struct socket *sock, struct msghdr *msg,
+			struct user_msghdr __user *umsg,
+			struct sockaddr __user *uaddr, unsigned int flags)
+{
+	return ____sys_recvmsg(sock, msg, umsg, uaddr, flags, 0);
+}
+
+long __sys_recvmsg(int fd, struct user_msghdr __user *msg, unsigned int flags,
+		   bool forbid_cmsg_compat)
+{
+	int fput_needed, err;
+	struct msghdr msg_sys;
+	struct socket *sock;
+
+	if (forbid_cmsg_compat && (flags & MSG_CMSG_COMPAT))
+		return -EINVAL;
+
+	sock = sockfd_lookup_light(fd, &err, &fput_needed);
+	if (!sock)
+		goto out;
+
+	err = ___sys_recvmsg(sock, msg, &msg_sys, flags, 0);
+
+	fput_light(sock->file, fput_needed);
+out:
+	return err;
+}
+
+SYSCALL_DEFINE3(recvmsg, int, fd, struct user_msghdr __user *, msg,
+		unsigned int, flags)
+{
+	return __sys_recvmsg(fd, msg, flags, true);
+}
+
+/*
+ *     Linux recvmmsg interface
+ */
+
+static int do_recvmmsg(int fd, struct mmsghdr __user *mmsg,
+			  unsigned int vlen, unsigned int flags,
+			  struct timespec64 *timeout)
+{
+	int fput_needed, err, datagrams;
+	struct socket *sock;
+	struct mmsghdr __user *entry;
+	struct compat_mmsghdr __user *compat_entry;
+	struct msghdr msg_sys;
+	struct timespec64 end_time;
+	struct timespec64 timeout64;
+
+	if (timeout &&
+	    poll_select_set_timeout(&end_time, timeout->tv_sec,
+				    timeout->tv_nsec))
+		return -EINVAL;
+
+	datagrams = 0;
+
+	sock = sockfd_lookup_light(fd, &err, &fput_needed);
+	if (!sock)
+		return err;
+
+	if (likely(!(flags & MSG_ERRQUEUE))) {
+		err = sock_error(sock->sk);
+		if (err) {
+			datagrams = err;
+			goto out_put;
+		}
+	}
+
+	entry = mmsg;
+	compat_entry = (struct compat_mmsghdr __user *)mmsg;
+
+	while (datagrams < vlen) {
+		/*
+		 * No need to ask LSM for more than the first datagram.
+		 */
+		if (MSG_CMSG_COMPAT & flags) {
+			err = ___sys_recvmsg(sock, (struct user_msghdr __user *)compat_entry,
+					     &msg_sys, flags & ~MSG_WAITFORONE,
+					     datagrams);
+			if (err < 0)
+				break;
+			err = __put_user(err, &compat_entry->msg_len);
+			++compat_entry;
+		} else {
+			err = ___sys_recvmsg(sock,
+					     (struct user_msghdr __user *)entry,
+					     &msg_sys, flags & ~MSG_WAITFORONE,
+					     datagrams);
+			if (err < 0)
+				break;
+			err = put_user(err, &entry->msg_len);
+			++entry;
+		}
+
+		if (err)
+			break;
+		++datagrams;
+
+		/* MSG_WAITFORONE turns on MSG_DONTWAIT after one packet */
+		if (flags & MSG_WAITFORONE)
+			flags |= MSG_DONTWAIT;
+
+		if (timeout) {
+			ktime_get_ts64(&timeout64);
+			*timeout = timespec64_sub(end_time, timeout64);
+			if (timeout->tv_sec < 0) {
+				timeout->tv_sec = timeout->tv_nsec = 0;
+				break;
+			}
+
+			/* Timeout, return less than vlen datagrams */
+			if (timeout->tv_nsec == 0 && timeout->tv_sec == 0)
+				break;
+		}
+
+		/* Out of band data, return right away */
+		if (msg_sys.msg_flags & MSG_OOB)
+			break;
+		cond_resched();
+	}
+
+	if (err == 0)
+		goto out_put;
+
+	if (datagrams == 0) {
+		datagrams = err;
+		goto out_put;
+	}
+
+	/*
+	 * We may return less entries than requested (vlen) if the
+	 * sock is non block and there aren't enough datagrams...
+	 */
+	if (err != -EAGAIN) {
+		/*
+		 * ... or  if recvmsg returns an error after we
+		 * received some datagrams, where we record the
+		 * error to return on the next call or if the
+		 * app asks about it using getsockopt(SO_ERROR).
+		 */
+		WRITE_ONCE(sock->sk->sk_err, -err);
+	}
+out_put:
+	fput_light(sock->file, fput_needed);
+
+	return datagrams;
+}
+
+int __sys_recvmmsg(int fd, struct mmsghdr __user *mmsg,
+		   unsigned int vlen, unsigned int flags,
+		   struct __kernel_timespec __user *timeout,
+		   struct old_timespec32 __user *timeout32)
+{
+	int datagrams;
+	struct timespec64 timeout_sys;
+
+	if (timeout && get_timespec64(&timeout_sys, timeout))
+		return -EFAULT;
+
+	if (timeout32 && get_old_timespec32(&timeout_sys, timeout32))
+		return -EFAULT;
+
+	if (!timeout && !timeout32)
+		return do_recvmmsg(fd, mmsg, vlen, flags, NULL);
+
+	datagrams = do_recvmmsg(fd, mmsg, vlen, flags, &timeout_sys);
+
+	if (datagrams <= 0)
+		return datagrams;
+
+	if (timeout && put_timespec64(&timeout_sys, timeout))
+		datagrams = -EFAULT;
+
+	if (timeout32 && put_old_timespec32(&timeout_sys, timeout32))
+		datagrams = -EFAULT;
+
+	return datagrams;
+}
+
+SYSCALL_DEFINE5(recvmmsg, int, fd, struct mmsghdr __user *, mmsg,
+		unsigned int, vlen, unsigned int, flags,
+		struct __kernel_timespec __user *, timeout)
+{
+	if (flags & MSG_CMSG_COMPAT)
+		return -EINVAL;
+
+	return __sys_recvmmsg(fd, mmsg, vlen, flags, timeout, NULL);
+}
+
+#ifdef CONFIG_COMPAT_32BIT_TIME
+SYSCALL_DEFINE5(recvmmsg_time32, int, fd, struct mmsghdr __user *, mmsg,
+		unsigned int, vlen, unsigned int, flags,
+		struct old_timespec32 __user *, timeout)
+{
+	if (flags & MSG_CMSG_COMPAT)
+		return -EINVAL;
+
+	return __sys_recvmmsg(fd, mmsg, vlen, flags, NULL, timeout);
+}
+#endif
+
+#ifdef __ARCH_WANT_SYS_SOCKETCALL
+/* Argument list sizes for sys_socketcall */
+#define AL(x) ((x) * sizeof(unsigned long))
+static const unsigned char nargs[21] = {
+	AL(0), AL(3), AL(3), AL(3), AL(2), AL(3),
+	AL(3), AL(3), AL(4), AL(4), AL(4), AL(6),
+	AL(6), AL(2), AL(5), AL(5), AL(3), AL(3),
+	AL(4), AL(5), AL(4)
+};
+
+#undef AL
+
+/*
+ *	System call vectors.
+ *
+ *	Argument checking cleaned up. Saved 20% in size.
+ *  This function doesn't need to set the kernel lock because
+ *  it is set by the callees.
+ */
+
+SYSCALL_DEFINE2(socketcall, int, call, unsigned long __user *, args)
+{
+	unsigned long a[AUDITSC_ARGS];
+	unsigned long a0, a1;
+	int err;
+	unsigned int len;
+
+	if (call < 1 || call > SYS_SENDMMSG)
+		return -EINVAL;
+	call = array_index_nospec(call, SYS_SENDMMSG + 1);
+
+	len = nargs[call];
+	if (len > sizeof(a))
+		return -EINVAL;
+
+	/* copy_from_user should be SMP safe. */
+	if (copy_from_user(a, args, len))
+		return -EFAULT;
+
+	err = audit_socketcall(nargs[call] / sizeof(unsigned long), a);
+	if (err)
+		return err;
+
+	a0 = a[0];
+	a1 = a[1];
+
+	switch (call) {
+	case SYS_SOCKET:
+		err = __sys_socket(a0, a1, a[2]);
+		break;
+	case SYS_BIND:
+		err = __sys_bind(a0, (struct sockaddr __user *)a1, a[2]);
+		break;
+	case SYS_CONNECT:
+		err = __sys_connect(a0, (struct sockaddr __user *)a1, a[2]);
+		break;
+	case SYS_LISTEN:
+		err = __sys_listen(a0, a1);
+		break;
+	case SYS_ACCEPT:
+		err = __sys_accept4(a0, (struct sockaddr __user *)a1,
+				    (int __user *)a[2], 0);
+		break;
+	case SYS_GETSOCKNAME:
+		err =
+		    __sys_getsockname(a0, (struct sockaddr __user *)a1,
+				      (int __user *)a[2]);
+		break;
+	case SYS_GETPEERNAME:
+		err =
+		    __sys_getpeername(a0, (struct sockaddr __user *)a1,
+				      (int __user *)a[2]);
+		break;
+	case SYS_SOCKETPAIR:
+		err = __sys_socketpair(a0, a1, a[2], (int __user *)a[3]);
+		break;
+	case SYS_SEND:
+		err = __sys_sendto(a0, (void __user *)a1, a[2], a[3],
+				   NULL, 0);
+		break;
+	case SYS_SENDTO:
+		err = __sys_sendto(a0, (void __user *)a1, a[2], a[3],
+				   (struct sockaddr __user *)a[4], a[5]);
+		break;
+	case SYS_RECV:
+		err = __sys_recvfrom(a0, (void __user *)a1, a[2], a[3],
+				     NULL, NULL);
+		break;
+	case SYS_RECVFROM:
+		err = __sys_recvfrom(a0, (void __user *)a1, a[2], a[3],
+				     (struct sockaddr __user *)a[4],
+				     (int __user *)a[5]);
+		break;
+	case SYS_SHUTDOWN:
+		err = __sys_shutdown(a0, a1);
+		break;
+	case SYS_SETSOCKOPT:
+		err = __sys_setsockopt(a0, a1, a[2], (char __user *)a[3],
+				       a[4]);
+		break;
+	case SYS_GETSOCKOPT:
+		err =
+		    __sys_getsockopt(a0, a1, a[2], (char __user *)a[3],
+				     (int __user *)a[4]);
+		break;
+	case SYS_SENDMSG:
+		err = __sys_sendmsg(a0, (struct user_msghdr __user *)a1,
+				    a[2], true);
+		break;
+	case SYS_SENDMMSG:
+		err = __sys_sendmmsg(a0, (struct mmsghdr __user *)a1, a[2],
+				     a[3], true);
+		break;
+	case SYS_RECVMSG:
+		err = __sys_recvmsg(a0, (struct user_msghdr __user *)a1,
+				    a[2], true);
+		break;
+	case SYS_RECVMMSG:
+		if (IS_ENABLED(CONFIG_64BIT))
+			err = __sys_recvmmsg(a0, (struct mmsghdr __user *)a1,
+					     a[2], a[3],
+					     (struct __kernel_timespec __user *)a[4],
+					     NULL);
+		else
+			err = __sys_recvmmsg(a0, (struct mmsghdr __user *)a1,
+					     a[2], a[3], NULL,
+					     (struct old_timespec32 __user *)a[4]);
+		break;
+	case SYS_ACCEPT4:
+		err = __sys_accept4(a0, (struct sockaddr __user *)a1,
+				    (int __user *)a[2], a[3]);
+		break;
+	default:
+		err = -EINVAL;
+		break;
+	}
+	return err;
+}
+
+#endif				/* __ARCH_WANT_SYS_SOCKETCALL */
+
+/**
+ *	sock_register - add a socket protocol handler
+ *	@ops: description of protocol
+ *
+ *	This function is called by a protocol handler that wants to
+ *	advertise its address family, and have it linked into the
+ *	socket interface. The value ops->family corresponds to the
+ *	socket system call protocol family.
+ */
+int sock_register(const struct net_proto_family *ops)
+{
+	int err;
+
+	if (ops->family >= NPROTO) {
+		pr_crit("protocol %d >= NPROTO(%d)\n", ops->family, NPROTO);
+		return -ENOBUFS;
+	}
+
+	spin_lock(&net_family_lock);
+	if (rcu_dereference_protected(net_families[ops->family],
+				      lockdep_is_held(&net_family_lock)))
+		err = -EEXIST;
+	else {
+		rcu_assign_pointer(net_families[ops->family], ops);
+		err = 0;
+	}
+	spin_unlock(&net_family_lock);
+
+	pr_info("NET: Registered protocol family %d\n", ops->family);
+	return err;
+}
+EXPORT_SYMBOL(sock_register);
+
+/**
+ *	sock_unregister - remove a protocol handler
+ *	@family: protocol family to remove
+ *
+ *	This function is called by a protocol handler that wants to
+ *	remove its address family, and have it unlinked from the
+ *	new socket creation.
+ *
+ *	If protocol handler is a module, then it can use module reference
+ *	counts to protect against new references. If protocol handler is not
+ *	a module then it needs to provide its own protection in
+ *	the ops->create routine.
+ */
+void sock_unregister(int family)
+{
+	BUG_ON(family < 0 || family >= NPROTO);
+
+	spin_lock(&net_family_lock);
+	RCU_INIT_POINTER(net_families[family], NULL);
+	spin_unlock(&net_family_lock);
+
+	synchronize_rcu();
+
+	pr_info("NET: Unregistered protocol family %d\n", family);
+}
+EXPORT_SYMBOL(sock_unregister);
+
+bool sock_is_registered(int family)
+{
+	return family < NPROTO && rcu_access_pointer(net_families[family]);
+}
+
+static int __init sock_init(void)
+{
+	int err;
+	/*
+	 *      Initialize the network sysctl infrastructure.
+	 */
+	err = net_sysctl_init();
+	if (err)
+		goto out;
+
+	/*
+	 *      Initialize skbuff SLAB cache
+	 */
+	skb_init();
+
+	/*
+	 *      Initialize the protocols module.
+	 */
+
+	init_inodecache();
+
+	err = register_filesystem(&sock_fs_type);
+	if (err)
+		goto out;
+	sock_mnt = kern_mount(&sock_fs_type);
+	if (IS_ERR(sock_mnt)) {
+		err = PTR_ERR(sock_mnt);
+		goto out_mount;
+	}
+
+	/* The real protocol initialization is performed in later initcalls.
+	 */
+
+#ifdef CONFIG_NETFILTER
+	err = netfilter_init();
+	if (err)
+		goto out;
+#endif
+
+	ptp_classifier_init();
+
+out:
+	return err;
+
+out_mount:
+	unregister_filesystem(&sock_fs_type);
+	goto out;
+}
+
+core_initcall(sock_init);	/* early initcall */
+
+#ifdef CONFIG_PROC_FS
+void socket_seq_show(struct seq_file *seq)
+{
+	seq_printf(seq, "sockets: used %d\n",
+		   sock_inuse_get(seq->private));
+}
+#endif				/* CONFIG_PROC_FS */
+
+#ifdef CONFIG_COMPAT
+static int compat_dev_ifconf(struct net *net, struct compat_ifconf __user *uifc32)
+{
+	struct compat_ifconf ifc32;
+	struct ifconf ifc;
+	int err;
+
+	if (copy_from_user(&ifc32, uifc32, sizeof(struct compat_ifconf)))
+		return -EFAULT;
+
+	ifc.ifc_len = ifc32.ifc_len;
+	ifc.ifc_req = compat_ptr(ifc32.ifcbuf);
+
+	rtnl_lock();
+	err = dev_ifconf(net, &ifc, sizeof(struct compat_ifreq));
+	rtnl_unlock();
+	if (err)
+		return err;
+
+	ifc32.ifc_len = ifc.ifc_len;
+	if (copy_to_user(uifc32, &ifc32, sizeof(struct compat_ifconf)))
+		return -EFAULT;
+
+	return 0;
+}
+
+static int compat_siocwandev(struct net *net, struct compat_ifreq __user *uifr32)
+{
+	compat_uptr_t uptr32;
+	struct ifreq ifr;
+	void __user *saved;
+	int err;
+
+	if (copy_from_user(&ifr, uifr32, sizeof(struct compat_ifreq)))
+		return -EFAULT;
+
+	if (get_user(uptr32, &uifr32->ifr_settings.ifs_ifsu))
+		return -EFAULT;
+
+	saved = ifr.ifr_settings.ifs_ifsu.raw_hdlc;
+	ifr.ifr_settings.ifs_ifsu.raw_hdlc = compat_ptr(uptr32);
+
+	err = dev_ioctl(net, SIOCWANDEV, &ifr, NULL);
+	if (!err) {
+		ifr.ifr_settings.ifs_ifsu.raw_hdlc = saved;
+		if (copy_to_user(uifr32, &ifr, sizeof(struct compat_ifreq)))
+			err = -EFAULT;
+	}
+	return err;
+}
+
+/* Handle ioctls that use ifreq::ifr_data and just need struct ifreq converted */
+static int compat_ifr_data_ioctl(struct net *net, unsigned int cmd,
+				 struct compat_ifreq __user *u_ifreq32)
+{
+	struct ifreq ifreq;
+	u32 data32;
+
+	if (!is_socket_ioctl_cmd(cmd))
+		return -ENOTTY;
+	if (copy_from_user(ifreq.ifr_name, u_ifreq32->ifr_name, IFNAMSIZ))
+		return -EFAULT;
+	if (get_user(data32, &u_ifreq32->ifr_data))
+		return -EFAULT;
+	ifreq.ifr_data = compat_ptr(data32);
+
+	return dev_ioctl(net, cmd, &ifreq, NULL);
+}
+
+static int compat_ifreq_ioctl(struct net *net, struct socket *sock,
+			      unsigned int cmd,
+			      struct compat_ifreq __user *uifr32)
+{
+	struct ifreq __user *uifr;
+	int err;
+
+	/* Handle the fact that while struct ifreq has the same *layout* on
+	 * 32/64 for everything but ifreq::ifru_ifmap and ifreq::ifru_data,
+	 * which are handled elsewhere, it still has different *size* due to
+	 * ifreq::ifru_ifmap (which is 16 bytes on 32 bit, 24 bytes on 64-bit,
+	 * resulting in struct ifreq being 32 and 40 bytes respectively).
+	 * As a result, if the struct happens to be at the end of a page and
+	 * the next page isn't readable/writable, we get a fault. To prevent
+	 * that, copy back and forth to the full size.
+	 */
+
+	uifr = compat_alloc_user_space(sizeof(*uifr));
+	if (copy_in_user(uifr, uifr32, sizeof(*uifr32)))
+		return -EFAULT;
+
+	err = sock_do_ioctl(net, sock, cmd, (unsigned long)uifr);
+
+	if (!err) {
+		switch (cmd) {
+		case SIOCGIFFLAGS:
+		case SIOCGIFMETRIC:
+		case SIOCGIFMTU:
+		case SIOCGIFMEM:
+		case SIOCGIFHWADDR:
+		case SIOCGIFINDEX:
+		case SIOCGIFADDR:
+		case SIOCGIFBRDADDR:
+		case SIOCGIFDSTADDR:
+		case SIOCGIFNETMASK:
+		case SIOCGIFPFLAGS:
+		case SIOCGIFTXQLEN:
+		case SIOCGMIIPHY:
+		case SIOCGMIIREG:
+		case SIOCGIFNAME:
+			if (copy_in_user(uifr32, uifr, sizeof(*uifr32)))
+				err = -EFAULT;
+			break;
+		}
+	}
+	return err;
+}
+
+static int compat_sioc_ifmap(struct net *net, unsigned int cmd,
+			struct compat_ifreq __user *uifr32)
+{
+	struct ifreq ifr;
+	struct compat_ifmap __user *uifmap32;
+	int err;
+
+	uifmap32 = &uifr32->ifr_ifru.ifru_map;
+	err = copy_from_user(&ifr, uifr32, sizeof(ifr.ifr_name));
+	err |= get_user(ifr.ifr_map.mem_start, &uifmap32->mem_start);
+	err |= get_user(ifr.ifr_map.mem_end, &uifmap32->mem_end);
+	err |= get_user(ifr.ifr_map.base_addr, &uifmap32->base_addr);
+	err |= get_user(ifr.ifr_map.irq, &uifmap32->irq);
+	err |= get_user(ifr.ifr_map.dma, &uifmap32->dma);
+	err |= get_user(ifr.ifr_map.port, &uifmap32->port);
+	if (err)
+		return -EFAULT;
+
+	err = dev_ioctl(net, cmd, &ifr, NULL);
+
+	if (cmd == SIOCGIFMAP && !err) {
+		err = copy_to_user(uifr32, &ifr, sizeof(ifr.ifr_name));
+		err |= put_user(ifr.ifr_map.mem_start, &uifmap32->mem_start);
+		err |= put_user(ifr.ifr_map.mem_end, &uifmap32->mem_end);
+		err |= put_user(ifr.ifr_map.base_addr, &uifmap32->base_addr);
+		err |= put_user(ifr.ifr_map.irq, &uifmap32->irq);
+		err |= put_user(ifr.ifr_map.dma, &uifmap32->dma);
+		err |= put_user(ifr.ifr_map.port, &uifmap32->port);
+		if (err)
+			err = -EFAULT;
+	}
+	return err;
+}
+
+/* Since old style bridge ioctl's endup using SIOCDEVPRIVATE
+ * for some operations; this forces use of the newer bridge-utils that
+ * use compatible ioctls
+ */
+static int old_bridge_ioctl(compat_ulong_t __user *argp)
+{
+	compat_ulong_t tmp;
+
+	if (get_user(tmp, argp))
+		return -EFAULT;
+	if (tmp == BRCTL_GET_VERSION)
+		return BRCTL_VERSION + 1;
+	return -EINVAL;
+}
+
+static int compat_sock_ioctl_trans(struct file *file, struct socket *sock,
+			 unsigned int cmd, unsigned long arg)
+{
+	void __user *argp = compat_ptr(arg);
+	struct sock *sk = sock->sk;
+	struct net *net = sock_net(sk);
+
+	if (cmd >= SIOCDEVPRIVATE && cmd <= (SIOCDEVPRIVATE + 15))
+		return compat_ifr_data_ioctl(net, cmd, argp);
+
+	switch (cmd) {
+	case SIOCSIFBR:
+	case SIOCGIFBR:
+		return old_bridge_ioctl(argp);
+	case SIOCGIFCONF:
+		return compat_dev_ifconf(net, argp);
+	case SIOCWANDEV:
+		return compat_siocwandev(net, argp);
+	case SIOCGIFMAP:
+	case SIOCSIFMAP:
+		return compat_sioc_ifmap(net, cmd, argp);
+	case SIOCGSTAMP_OLD:
+	case SIOCGSTAMPNS_OLD:
+		if (!sock->ops->gettstamp)
+			return -ENOIOCTLCMD;
+		return sock->ops->gettstamp(sock, argp, cmd == SIOCGSTAMP_OLD,
+					    !COMPAT_USE_64BIT_TIME);
+
+	case SIOCETHTOOL:
+	case SIOCBONDSLAVEINFOQUERY:
+	case SIOCBONDINFOQUERY:
+	case SIOCSHWTSTAMP:
+	case SIOCGHWTSTAMP:
+		return compat_ifr_data_ioctl(net, cmd, argp);
+
+	case FIOSETOWN:
+	case SIOCSPGRP:
+	case FIOGETOWN:
+	case SIOCGPGRP:
+	case SIOCBRADDBR:
+	case SIOCBRDELBR:
+	case SIOCGIFVLAN:
+	case SIOCSIFVLAN:
+	case SIOCADDDLCI:
+	case SIOCDELDLCI:
+	case SIOCGSKNS:
+	case SIOCGSTAMP_NEW:
+	case SIOCGSTAMPNS_NEW:
+		return sock_ioctl(file, cmd, arg);
+
+	case SIOCGIFFLAGS:
+	case SIOCSIFFLAGS:
+	case SIOCGIFMETRIC:
+	case SIOCSIFMETRIC:
+	case SIOCGIFMTU:
+	case SIOCSIFMTU:
+	case SIOCGIFMEM:
+	case SIOCSIFMEM:
+	case SIOCGIFHWADDR:
+	case SIOCSIFHWADDR:
+	case SIOCADDMULTI:
+	case SIOCDELMULTI:
+	case SIOCGIFINDEX:
+	case SIOCGIFADDR:
+	case SIOCSIFADDR:
+	case SIOCSIFHWBROADCAST:
+	case SIOCDIFADDR:
+	case SIOCGIFBRDADDR:
+	case SIOCSIFBRDADDR:
+	case SIOCGIFDSTADDR:
+	case SIOCSIFDSTADDR:
+	case SIOCGIFNETMASK:
+	case SIOCSIFNETMASK:
+	case SIOCSIFPFLAGS:
+	case SIOCGIFPFLAGS:
+	case SIOCGIFTXQLEN:
+	case SIOCSIFTXQLEN:
+	case SIOCBRADDIF:
+	case SIOCBRDELIF:
+	case SIOCGIFNAME:
+	case SIOCSIFNAME:
+	case SIOCGMIIPHY:
+	case SIOCGMIIREG:
+	case SIOCSMIIREG:
+	case SIOCBONDENSLAVE:
+	case SIOCBONDRELEASE:
+	case SIOCBONDSETHWADDR:
+	case SIOCBONDCHANGEACTIVE:
+		return compat_ifreq_ioctl(net, sock, cmd, argp);
+
+	case SIOCSARP:
+	case SIOCGARP:
+	case SIOCDARP:
+	case SIOCOUTQ:
+	case SIOCOUTQNSD:
+	case SIOCATMARK:
+		return sock_do_ioctl(net, sock, cmd, arg);
+	}
+
+	return -ENOIOCTLCMD;
+}
+
+static long compat_sock_ioctl(struct file *file, unsigned int cmd,
+			      unsigned long arg)
+{
+	struct socket *sock = file->private_data;
+	int ret = -ENOIOCTLCMD;
+	struct sock *sk;
+	struct net *net;
+
+	sk = sock->sk;
+	net = sock_net(sk);
+
+	if (sock->ops->compat_ioctl)
+		ret = sock->ops->compat_ioctl(sock, cmd, arg);
+
+	if (ret == -ENOIOCTLCMD &&
+	    (cmd >= SIOCIWFIRST && cmd <= SIOCIWLAST))
+		ret = compat_wext_handle_ioctl(net, cmd, arg);
+
+	if (ret == -ENOIOCTLCMD)
+		ret = compat_sock_ioctl_trans(file, sock, cmd, arg);
+
+	return ret;
+}
+#endif
+
+/**
+ *	kernel_bind - bind an address to a socket (kernel space)
+ *	@sock: socket
+ *	@addr: address
+ *	@addrlen: length of address
+ *
+ *	Returns 0 or an error.
+ */
+
+int kernel_bind(struct socket *sock, struct sockaddr *addr, int addrlen)
+{
+	struct sockaddr_storage address;
+
+	memcpy(&address, addr, addrlen);
+
+	return sock->ops->bind(sock, (struct sockaddr *)&address, addrlen);
+}
+EXPORT_SYMBOL(kernel_bind);
+
+/**
+ *	kernel_listen - move socket to listening state (kernel space)
+ *	@sock: socket
+ *	@backlog: pending connections queue size
+ *
+ *	Returns 0 or an error.
+ */
+
+int kernel_listen(struct socket *sock, int backlog)
+{
+	return sock->ops->listen(sock, backlog);
+}
+EXPORT_SYMBOL(kernel_listen);
+
+/**
+ *	kernel_accept - accept a connection (kernel space)
+ *	@sock: listening socket
+ *	@newsock: new connected socket
+ *	@flags: flags
+ *
+ *	@flags must be SOCK_CLOEXEC, SOCK_NONBLOCK or 0.
+ *	If it fails, @newsock is guaranteed to be %NULL.
+ *	Returns 0 or an error.
+ */
+
+int kernel_accept(struct socket *sock, struct socket **newsock, int flags)
+{
+	struct sock *sk = sock->sk;
+	int err;
+
+	err = sock_create_lite(sk->sk_family, sk->sk_type, sk->sk_protocol,
+			       newsock);
+	if (err < 0)
+		goto done;
+
+	err = sock->ops->accept(sock, *newsock, flags, true);
+	if (err < 0) {
+		sock_release(*newsock);
+		*newsock = NULL;
+		goto done;
+	}
+
+	(*newsock)->ops = sock->ops;
+	__module_get((*newsock)->ops->owner);
+
+done:
+	return err;
+}
+EXPORT_SYMBOL(kernel_accept);
+
+/**
+ *	kernel_connect - connect a socket (kernel space)
+ *	@sock: socket
+ *	@addr: address
+ *	@addrlen: address length
+ *	@flags: flags (O_NONBLOCK, ...)
+ *
+ *	For datagram sockets, @addr is the addres to which datagrams are sent
+ *	by default, and the only address from which datagrams are received.
+ *	For stream sockets, attempts to connect to @addr.
+ *	Returns 0 or an error code.
+ */
+
+int kernel_connect(struct socket *sock, struct sockaddr *addr, int addrlen,
+		   int flags)
+{
+	struct sockaddr_storage address;
+
+	memcpy(&address, addr, addrlen);
+
+	return sock->ops->connect(sock, (struct sockaddr *)&address, addrlen, flags);
+}
+EXPORT_SYMBOL(kernel_connect);
+
+/**
+ *	kernel_getsockname - get the address which the socket is bound (kernel space)
+ *	@sock: socket
+ *	@addr: address holder
+ *
+ * 	Fills the @addr pointer with the address which the socket is bound.
+ *	Returns 0 or an error code.
+ */
+
+int kernel_getsockname(struct socket *sock, struct sockaddr *addr)
+{
+	return sock->ops->getname(sock, addr, 0);
+}
+EXPORT_SYMBOL(kernel_getsockname);
+
+/**
+ *	kernel_getpeername - get the address which the socket is connected (kernel space)
+ *	@sock: socket
+ *	@addr: address holder
+ *
+ * 	Fills the @addr pointer with the address which the socket is connected.
+ *	Returns 0 or an error code.
+ */
+
+int kernel_getpeername(struct socket *sock, struct sockaddr *addr)
+{
+	return sock->ops->getname(sock, addr, 1);
+}
+EXPORT_SYMBOL(kernel_getpeername);
+
+/**
+ *	kernel_sendpage - send a &page through a socket (kernel space)
+ *	@sock: socket
+ *	@page: page
+ *	@offset: page offset
+ *	@size: total size in bytes
+ *	@flags: flags (MSG_DONTWAIT, ...)
+ *
+ *	Returns the total amount sent in bytes or an error.
+ */
+
+int kernel_sendpage(struct socket *sock, struct page *page, int offset,
+		    size_t size, int flags)
+{
+	if (sock->ops->sendpage) {
+		/* Warn in case the improper page to zero-copy send */
+		WARN_ONCE(!sendpage_ok(page), "improper page for zero-copy send");
+		return sock->ops->sendpage(sock, page, offset, size, flags);
+	}
+	return sock_no_sendpage(sock, page, offset, size, flags);
+}
+EXPORT_SYMBOL(kernel_sendpage);
+
+/**
+ *	kernel_sendpage_locked - send a &page through the locked sock (kernel space)
+ *	@sk: sock
+ *	@page: page
+ *	@offset: page offset
+ *	@size: total size in bytes
+ *	@flags: flags (MSG_DONTWAIT, ...)
+ *
+ *	Returns the total amount sent in bytes or an error.
+ *	Caller must hold @sk.
+ */
+
+int kernel_sendpage_locked(struct sock *sk, struct page *page, int offset,
+			   size_t size, int flags)
+{
+	struct socket *sock = sk->sk_socket;
+
+	if (sock->ops->sendpage_locked)
+		return sock->ops->sendpage_locked(sk, page, offset, size,
+						  flags);
+
+	return sock_no_sendpage_locked(sk, page, offset, size, flags);
+}
+EXPORT_SYMBOL(kernel_sendpage_locked);
+
+/**
+ *	kernel_sock_shutdown - shut down part of a full-duplex connection (kernel space)
+ *	@sock: socket
+ *	@how: connection part
+ *
+ *	Returns 0 or an error.
+ */
+
+int kernel_sock_shutdown(struct socket *sock, enum sock_shutdown_cmd how)
+{
+	return sock->ops->shutdown(sock, how);
+}
+EXPORT_SYMBOL(kernel_sock_shutdown);
+
+/**
+ *	kernel_sock_ip_overhead - returns the IP overhead imposed by a socket
+ *	@sk: socket
+ *
+ *	This routine returns the IP overhead imposed by a socket i.e.
+ *	the length of the underlying IP header, depending on whether
+ *	this is an IPv4 or IPv6 socket and the length from IP options turned
+ *	on at the socket. Assumes that the caller has a lock on the socket.
+ */
+
+u32 kernel_sock_ip_overhead(struct sock *sk)
+{
+	struct inet_sock *inet;
+	struct ip_options_rcu *opt;
+	u32 overhead = 0;
+#if IS_ENABLED(CONFIG_IPV6)
+	struct ipv6_pinfo *np;
+	struct ipv6_txoptions *optv6 = NULL;
+#endif /* IS_ENABLED(CONFIG_IPV6) */
+
+	if (!sk)
+		return overhead;
+
+	switch (sk->sk_family) {
+	case AF_INET:
+		inet = inet_sk(sk);
+		overhead += sizeof(struct iphdr);
+		opt = rcu_dereference_protected(inet->inet_opt,
+						sock_owned_by_user(sk));
+		if (opt)
+			overhead += opt->opt.optlen;
+		return overhead;
+#if IS_ENABLED(CONFIG_IPV6)
+	case AF_INET6:
+		np = inet6_sk(sk);
+		overhead += sizeof(struct ipv6hdr);
+		if (np)
+			optv6 = rcu_dereference_protected(np->opt,
+							  sock_owned_by_user(sk));
+		if (optv6)
+			overhead += (optv6->opt_flen + optv6->opt_nflen);
+		return overhead;
+#endif /* IS_ENABLED(CONFIG_IPV6) */
+	default: /* Returns 0 overhead if the socket is not ipv4 or ipv6 */
+		return overhead;
+	}
+}
+EXPORT_SYMBOL(kernel_sock_ip_overhead);