socket.c

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/*
 * NET      An implementation of the SOCKET network access protocol.
 *
 * Version: @(#)socket.c    1.1.93  18/02/95
 *
 * Authors: Orest Zborowski, <[email protected]>
 *      Ross Biro
 *      Fred N. van Kempen, <[email protected]>
 *
 * 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 program is free software; you can redistribute it and/or
 *      modify it under the terms of the GNU General Public License
 *      as published by the Free Software Foundation; either version
 *      2 of the License, or (at your option) any later version.
 *
 *
 *  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/wanrouter.h>
#include <linux/if_bridge.h>
#include <linux/if_frad.h>
#include <linux/if_vlan.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/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 <asm/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/sockios.h>
#include <linux/atalk.h>

static int sock_no_open(struct inode *irrelevant, struct file *dontcare);
static ssize_t sock_aio_read(struct kiocb *iocb, const struct iovec *iov,
             unsigned long nr_segs, loff_t pos);
static ssize_t sock_aio_write(struct kiocb *iocb, const struct iovec *iov,
              unsigned long nr_segs, loff_t pos);
static int sock_mmap(struct file *file, struct vm_area_struct *vma);

static int sock_close(struct inode *inode, struct file *file);
static unsigned int 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);

/*
 *  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,
    .aio_read = sock_aio_read,
    .aio_write =    sock_aio_write,
    .poll =     sock_poll,
    .unlocked_ioctl = sock_ioctl,
#ifdef CONFIG_COMPAT
    .compat_ioctl = compat_sock_ioctl,
#endif
    .mmap =     sock_mmap,
    .open =     sock_no_open,   /* special open code to disallow open via /proc */
    .release =  sock_close,
    .fasync =   sock_fasync,
    .sendpage = sock_sendpage,
    .splice_write = generic_splice_sendpage,
    .splice_read =  sock_splice_read,
};

/*
 *  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;

/*
 *  Statistics counters of the socket lists
 */

static DEFINE_PER_CPU(int, sockets_in_use);

/*
 * Support routines.
 * Move socket addresses back and forth across the kernel/user
 * divide and look after the messy bits.
 */

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);
}

static int move_addr_to_user(struct sockaddr_storage *kaddr, int klen,
                 void __user *uaddr, int __user *ulen)
{
    int err;
    int len;

    err = get_user(len, ulen);
    if (err)
        return err;
    if (len > klen)
        len = klen;
    if (len < 0 || len > sizeof(struct sockaddr_storage))
        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 __read_mostly;

static struct inode *sock_alloc_inode(struct super_block *sb)
{
    struct socket_alloc *ei;
    struct socket_wq *wq;

    ei = kmem_cache_alloc(sock_inode_cachep, GFP_KERNEL);
    if (!ei)
        return NULL;
    wq = kmalloc(sizeof(*wq), GFP_KERNEL);
    if (!wq) {
        kmem_cache_free(sock_inode_cachep, ei);
        return NULL;
    }
    init_waitqueue_head(&wq->wait);
    wq->fasync_list = NULL;
    RCU_INIT_POINTER(ei->socket.wq, wq);

    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_destroy_inode(struct inode *inode)
{
    struct socket_alloc *ei;
    struct socket_wq *wq;

    ei = container_of(inode, struct socket_alloc, vfs_inode);
    wq = rcu_dereference_protected(ei->socket.wq, 1);
    kfree_rcu(wq, rcu);
    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 int 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),
                          init_once);
    if (sock_inode_cachep == NULL)
        return -ENOMEM;
    return 0;
}

static const struct super_operations sockfs_ops = {
    .alloc_inode    = sock_alloc_inode,
    .destroy_inode  = sock_destroy_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]",
                dentry->d_inode->i_ino);
}

static const struct dentry_operations sockfs_dentry_operations = {
    .d_dname  = sockfs_dname,
};

static struct dentry *sockfs_mount(struct file_system_type *fs_type,
             int flags, const char *dev_name, void *data)
{
    return mount_pseudo(fs_type, "socket:", &sockfs_ops,
        &sockfs_dentry_operations, SOCKFS_MAGIC);
}

static struct vfsmount *sock_mnt __read_mostly;

static struct file_system_type sock_fs_type = {
    .name =     "sockfs",
    .mount =    sockfs_mount,
    .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.
 */

struct file *sock_alloc_file(struct socket *sock, int flags, const char *dname)
{
    struct qstr name = { .name = "" };
    struct path path;
    struct file *file;

    if (dname) {
        name.name = dname;
        name.len = strlen(name.name);
    } else if (sock->sk) {
        name.name = sock->sk->sk_prot_creator->name;
        name.len = strlen(name.name);
    }
    path.dentry = d_alloc_pseudo(sock_mnt->mnt_sb, &name);
    if (unlikely(!path.dentry))
        return ERR_PTR(-ENOMEM);
    path.mnt = mntget(sock_mnt);

    d_instantiate(path.dentry, SOCK_INODE(sock));
    SOCK_INODE(sock)->i_fop = &socket_file_ops;

    file = alloc_file(&path, FMODE_READ | FMODE_WRITE,
          &socket_file_ops);
    if (unlikely(!file)) {
        /* drop dentry, keep inode */
        ihold(path.dentry->d_inode);
        path_put(&path);
        return ERR_PTR(-ENFILE);
    }

    sock->file = file;
    file->f_flags = O_RDWR | (flags & O_NONBLOCK);
    file->f_pos = 0;
    file->private_data = sock;
    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))
        return fd;

    newfile = sock_alloc_file(sock, flags, NULL);
    if (likely(!IS_ERR(newfile))) {
        fd_install(fd, newfile);
        return fd;
    }

    put_unused_fd(fd);
    return PTR_ERR(newfile);
}

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);

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 file *file;
    struct socket *sock;

    *err = -EBADF;
    file = fget_light(fd, fput_needed);
    if (file) {
        sock = sock_from_file(file, err);
        if (sock)
            return sock;
        fput_light(file, *fput_needed);
    }
    return NULL;
}

#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 ssize_t sockfs_getxattr(struct dentry *dentry,
                   const char *name, void *value, size_t size)
{
    const char *proto_name;
    size_t proto_size;
    int error;

    error = -ENODATA;
    if (!strncmp(name, XATTR_NAME_SOCKPROTONAME, XATTR_NAME_SOCKPROTONAME_LEN)) {
        proto_name = dentry->d_name.name;
        proto_size = strlen(proto_name);

        if (value) {
            error = -ERANGE;
            if (proto_size + 1 > size)
                goto out;

            strncpy(value, proto_name, proto_size + 1);
        }
        error = proto_size + 1;
    }

out:
    return error;
}

static ssize_t sockfs_listxattr(struct dentry *dentry, char *buffer,
                size_t size)
{
    ssize_t len;
    ssize_t used = 0;

    len = security_inode_listsecurity(dentry->d_inode, 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 const struct inode_operations sockfs_inode_ops = {
    .getxattr = sockfs_getxattr,
    .listxattr = sockfs_listxattr,
};

static 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);

    kmemcheck_annotate_bitfield(sock, type);
    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;

    this_cpu_add(sockets_in_use, 1);
    return sock;
}

/*
 *  In theory you can't get an open on this inode, but /proc provides
 *  a back door. Remember to keep it shut otherwise you'll let the
 *  creepy crawlies in.
 */

static int sock_no_open(struct inode *irrelevant, struct file *dontcare)
{
    return -ENXIO;
}

const struct file_operations bad_sock_fops = {
    .owner = THIS_MODULE,
    .open = sock_no_open,
    .llseek = noop_llseek,
};

void sock_release(struct socket *sock)
{
    if (sock->ops) {
        struct module *owner = sock->ops->owner;

        sock->ops->release(sock);
        sock->ops = NULL;
        module_put(owner);
    }

    if (rcu_dereference_protected(sock->wq, 1)->fasync_list)
        printk(KERN_ERR "sock_release: fasync list not empty!\n");

    if (test_bit(SOCK_EXTERNALLY_ALLOCATED, &sock->flags))
        return;

    this_cpu_sub(sockets_in_use, 1);
    if (!sock->file) {
        iput(SOCK_INODE(sock));
        return;
    }
    sock->file = NULL;
}
EXPORT_SYMBOL(sock_release);

int sock_tx_timestamp(struct sock *sk, __u8 *tx_flags)
{
    *tx_flags = 0;
    if (sock_flag(sk, SOCK_TIMESTAMPING_TX_HARDWARE))
        *tx_flags |= SKBTX_HW_TSTAMP;
    if (sock_flag(sk, SOCK_TIMESTAMPING_TX_SOFTWARE))
        *tx_flags |= SKBTX_SW_TSTAMP;
    if (sock_flag(sk, SOCK_WIFI_STATUS))
        *tx_flags |= SKBTX_WIFI_STATUS;
    return 0;
}
EXPORT_SYMBOL(sock_tx_timestamp);

static inline int __sock_sendmsg_nosec(struct kiocb *iocb, struct socket *sock,
                       struct msghdr *msg, size_t size)
{
    struct sock_iocb *si = kiocb_to_siocb(iocb);

    sock_update_classid(sock->sk);

    si->sock = sock;
    si->scm = NULL;
    si->msg = msg;
    si->size = size;

    return sock->ops->sendmsg(iocb, sock, msg, size);
}

static inline int __sock_sendmsg(struct kiocb *iocb, struct socket *sock,
                 struct msghdr *msg, size_t size)
{
    int err = security_socket_sendmsg(sock, msg, size);

    return err ?: __sock_sendmsg_nosec(iocb, sock, msg, size);
}

int sock_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
{
    struct kiocb iocb;
    struct sock_iocb siocb;
    int ret;

    init_sync_kiocb(&iocb, NULL);
    iocb.private = &siocb;
    ret = __sock_sendmsg(&iocb, sock, msg, size);
    if (-EIOCBQUEUED == ret)
        ret = wait_on_sync_kiocb(&iocb);
    return ret;
}
EXPORT_SYMBOL(sock_sendmsg);

static int sock_sendmsg_nosec(struct socket *sock, struct msghdr *msg, size_t size)
{
    struct kiocb iocb;
    struct sock_iocb siocb;
    int ret;

    init_sync_kiocb(&iocb, NULL);
    iocb.private = &siocb;
    ret = __sock_sendmsg_nosec(&iocb, sock, msg, size);
    if (-EIOCBQUEUED == ret)
        ret = wait_on_sync_kiocb(&iocb);
    return ret;
}

int kernel_sendmsg(struct socket *sock, struct msghdr *msg,
           struct kvec *vec, size_t num, size_t size)
{
    mm_segment_t oldfs = get_fs();
    int result;

    set_fs(KERNEL_DS);
    /*
     * the following is safe, since for compiler definitions of kvec and
     * iovec are identical, yielding the same in-core layout and alignment
     */
    msg->msg_iov = (struct iovec *)vec;
    msg->msg_iovlen = num;
    result = sock_sendmsg(sock, msg, size);
    set_fs(oldfs);
    return result;
}
EXPORT_SYMBOL(kernel_sendmsg);

static int ktime2ts(ktime_t kt, struct timespec *ts)
{
    if (kt.tv64) {
        *ts = ktime_to_timespec(kt);
        return 1;
    } else {
        return 0;
    }
}

/*
 * 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);
    struct timespec ts[3];
    int empty = 1;
    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.tv64 == 0)
        __net_timestamp(skb);

    if (need_software_tstamp) {
        if (!sock_flag(sk, SOCK_RCVTSTAMPNS)) {
            struct timeval tv;
            skb_get_timestamp(skb, &tv);
            put_cmsg(msg, SOL_SOCKET, SCM_TIMESTAMP,
                 sizeof(tv), &tv);
        } else {
            skb_get_timestampns(skb, &ts[0]);
            put_cmsg(msg, SOL_SOCKET, SCM_TIMESTAMPNS,
                 sizeof(ts[0]), &ts[0]);
        }
    }


    memset(ts, 0, sizeof(ts));
    if (skb->tstamp.tv64 &&
        sock_flag(sk, SOCK_TIMESTAMPING_SOFTWARE)) {
        skb_get_timestampns(skb, ts + 0);
        empty = 0;
    }
    if (shhwtstamps) {
        if (sock_flag(sk, SOCK_TIMESTAMPING_SYS_HARDWARE) &&
            ktime2ts(shhwtstamps->syststamp, ts + 1))
            empty = 0;
        if (sock_flag(sk, SOCK_TIMESTAMPING_RAW_HARDWARE) &&
            ktime2ts(shhwtstamps->hwtstamp, ts + 2))
            empty = 0;
    }
    if (!empty)
        put_cmsg(msg, SOL_SOCKET,
             SCM_TIMESTAMPING, sizeof(ts), &ts);
}
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 && skb->dropcount)
        put_cmsg(msg, SOL_SOCKET, SO_RXQ_OVFL,
            sizeof(__u32), &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);

static inline int __sock_recvmsg_nosec(struct kiocb *iocb, struct socket *sock,
                       struct msghdr *msg, size_t size, int flags)
{
    struct sock_iocb *si = kiocb_to_siocb(iocb);

    sock_update_classid(sock->sk);

    si->sock = sock;
    si->scm = NULL;
    si->msg = msg;
    si->size = size;
    si->flags = flags;

    return sock->ops->recvmsg(iocb, sock, msg, size, flags);
}

static inline int __sock_recvmsg(struct kiocb *iocb, struct socket *sock,
                 struct msghdr *msg, size_t size, int flags)
{
    int err = security_socket_recvmsg(sock, msg, size, flags);

    return err ?: __sock_recvmsg_nosec(iocb, sock, msg, size, flags);
}

int sock_recvmsg(struct socket *sock, struct msghdr *msg,
         size_t size, int flags)
{
    struct kiocb iocb;
    struct sock_iocb siocb;
    int ret;

    init_sync_kiocb(&iocb, NULL);
    iocb.private = &siocb;
    ret = __sock_recvmsg(&iocb, sock, msg, size, flags);
    if (-EIOCBQUEUED == ret)
        ret = wait_on_sync_kiocb(&iocb);
    return ret;
}
EXPORT_SYMBOL(sock_recvmsg);

static int sock_recvmsg_nosec(struct socket *sock, struct msghdr *msg,
                  size_t size, int flags)
{
    struct kiocb iocb;
    struct sock_iocb siocb;
    int ret;

    init_sync_kiocb(&iocb, NULL);
    iocb.private = &siocb;
    ret = __sock_recvmsg_nosec(&iocb, sock, msg, size, flags);
    if (-EIOCBQUEUED == ret)
        ret = wait_on_sync_kiocb(&iocb);
    return ret;
}

int kernel_recvmsg(struct socket *sock, struct msghdr *msg,
           struct kvec *vec, size_t num, size_t size, int flags)
{
    mm_segment_t oldfs = get_fs();
    int result;

    set_fs(KERNEL_DS);
    /*
     * the following is safe, since for compiler definitions of kvec and
     * iovec are identical, yielding the same in-core layout and alignment
     */
    msg->msg_iov = (struct iovec *)vec, msg->msg_iovlen = num;
    result = sock_recvmsg(sock, msg, size, flags);
    set_fs(oldfs);
    return result;
}
EXPORT_SYMBOL(kernel_recvmsg);

static void sock_aio_dtor(struct kiocb *iocb)
{
    kfree(iocb->private);
}

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 -EINVAL;

    sock_update_classid(sock->sk);

    return sock->ops->splice_read(sock, ppos, pipe, len, flags);
}

static struct sock_iocb *alloc_sock_iocb(struct kiocb *iocb,
                     struct sock_iocb *siocb)
{
    if (!is_sync_kiocb(iocb)) {
        siocb = kmalloc(sizeof(*siocb), GFP_KERNEL);
        if (!siocb)
            return NULL;
        iocb->ki_dtor = sock_aio_dtor;
    }

    siocb->kiocb = iocb;
    iocb->private = siocb;
    return siocb;
}

static ssize_t do_sock_read(struct msghdr *msg, struct kiocb *iocb,
        struct file *file, const struct iovec *iov,
        unsigned long nr_segs)
{
    struct socket *sock = file->private_data;
    size_t size = 0;
    int i;

    for (i = 0; i < nr_segs; i++)
        size += iov[i].iov_len;

    msg->msg_name = NULL;
    msg->msg_namelen = 0;
    msg->msg_control = NULL;
    msg->msg_controllen = 0;
    msg->msg_iov = (struct iovec *)iov;
    msg->msg_iovlen = nr_segs;
    msg->msg_flags = (file->f_flags & O_NONBLOCK) ? MSG_DONTWAIT : 0;

    return __sock_recvmsg(iocb, sock, msg, size, msg->msg_flags);
}

static ssize_t sock_aio_read(struct kiocb *iocb, const struct iovec *iov,
                unsigned long nr_segs, loff_t pos)
{
    struct sock_iocb siocb, *x;

    if (pos != 0)
        return -ESPIPE;

    if (iocb->ki_left == 0) /* Match SYS5 behaviour */
        return 0;


    x = alloc_sock_iocb(iocb, &siocb);
    if (!x)
        return -ENOMEM;
    return do_sock_read(&x->async_msg, iocb, iocb->ki_filp, iov, nr_segs);
}

static ssize_t do_sock_write(struct msghdr *msg, struct kiocb *iocb,
            struct file *file, const struct iovec *iov,
            unsigned long nr_segs)
{
    struct socket *sock = file->private_data;
    size_t size = 0;
    int i;

    for (i = 0; i < nr_segs; i++)
        size += iov[i].iov_len;

    msg->msg_name = NULL;
    msg->msg_namelen = 0;
    msg->msg_control = NULL;
    msg->msg_controllen = 0;
    msg->msg_iov = (struct iovec *)iov;
    msg->msg_iovlen = nr_segs;
    msg->msg_flags = (file->f_flags & O_NONBLOCK) ? MSG_DONTWAIT : 0;
    if (sock->type == SOCK_SEQPACKET)
        msg->msg_flags |= MSG_EOR;

    return __sock_sendmsg(iocb, sock, msg, size);
}

static ssize_t sock_aio_write(struct kiocb *iocb, const struct iovec *iov,
              unsigned long nr_segs, loff_t pos)
{
    struct sock_iocb siocb, *x;

    if (pos != 0)
        return -ESPIPE;

    x = alloc_sock_iocb(iocb, &siocb);
    if (!x)
        return -ENOMEM;

    return do_sock_write(&x->async_msg, iocb, iocb->ki_filp, iov, nr_segs);
}

/*
 * 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)
        err = dev_ioctl(net, cmd, argp);

    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 (cmd >= SIOCDEVPRIVATE && cmd <= (SIOCDEVPRIVATE + 15)) {
        err = dev_ioctl(net, cmd, argp);
    } else
#ifdef CONFIG_WEXT_CORE
    if (cmd >= SIOCIWFIRST && cmd <= SIOCIWLAST) {
        err = dev_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;
        default:
            err = sock_do_ioctl(net, sock, cmd, arg);
            break;
        }
    return err;
}

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 unsigned int sock_poll(struct file *file, poll_table *wait)
{
    struct socket *sock;

    /*
     *      We can't return errors to poll, so it's either yes or no.
     */
    sock = file->private_data;
    return sock->ops->poll(file, sock, wait);
}

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)
{
    /*
     *      It was possible the inode is NULL we were
     *      closing an unfinished socket.
     */

    if (!inode) {
        printk(KERN_DEBUG "sock_close: NULL inode\n");
        return 0;
    }
    sock_release(SOCKET_I(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;

    if (sk == NULL)
        return -EINVAL;

    lock_sock(sk);
    wq = rcu_dereference_protected(sock->wq, sock_owned_by_user(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 socket lock or callback_lock or rcu_lock */

int sock_wake_async(struct socket *sock, int how, int band)
{
    struct socket_wq *wq;

    if (!sock)
        return -1;
    rcu_read_lock();
    wq = rcu_dereference(sock->wq);
    if (!wq || !wq->fasync_list) {
        rcu_read_unlock();
        return -1;
    }
    switch (how) {
    case SOCK_WAKE_WAITD:
        if (test_bit(SOCK_ASYNC_WAITDATA, &sock->flags))
            break;
        goto call_kill;
    case SOCK_WAKE_SPACE:
        if (!test_and_clear_bit(SOCK_ASYNC_NOSPACE, &sock->flags))
            break;
        /* fall through */
    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);
    }
    rcu_read_unlock();
    return 0;
}
EXPORT_SYMBOL(sock_wake_async);

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) {
        static int warned;
        if (!warned) {
            warned = 1;
            printk(KERN_INFO "%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);

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);

int sock_create_kern(int family, int type, int protocol, struct socket **res)
{
    return __sock_create(&init_net, family, type, protocol, res, 1);
}
EXPORT_SYMBOL(sock_create_kern);

SYSCALL_DEFINE3(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)
        goto out;

    retval = sock_map_fd(sock, flags & (O_CLOEXEC | O_NONBLOCK));
    if (retval < 0)
        goto out_release;

out:
    /* It may be already another descriptor 8) Not kernel problem. */
    return retval;

out_release:
    sock_release(sock);
    return retval;
}

/*
 *  Create a pair of connected sockets.
 */

SYSCALL_DEFINE4(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;

    /*
     * Obtain the first socket and check if the underlying protocol
     * supports the socketpair call.
     */

    err = sock_create(family, type, protocol, &sock1);
    if (err < 0)
        goto out;

    err = sock_create(family, type, protocol, &sock2);
    if (err < 0)
        goto out_release_1;

    err = sock1->ops->socketpair(sock1, sock2);
    if (err < 0)
        goto out_release_both;

    fd1 = get_unused_fd_flags(flags);
    if (unlikely(fd1 < 0)) {
        err = fd1;
        goto out_release_both;
    }
    fd2 = get_unused_fd_flags(flags);
    if (unlikely(fd2 < 0)) {
        err = fd2;
        put_unused_fd(fd1);
        goto out_release_both;
    }

    newfile1 = sock_alloc_file(sock1, flags, NULL);
    if (unlikely(IS_ERR(newfile1))) {
        err = PTR_ERR(newfile1);
        put_unused_fd(fd1);
        put_unused_fd(fd2);
        goto out_release_both;
    }

    newfile2 = sock_alloc_file(sock2, flags, NULL);
    if (IS_ERR(newfile2)) {
        err = PTR_ERR(newfile2);
        fput(newfile1);
        put_unused_fd(fd1);
        put_unused_fd(fd2);
        sock_release(sock2);
        goto out;
    }

    audit_fd_pair(fd1, fd2);
    fd_install(fd1, newfile1);
    fd_install(fd2, newfile2);
    /* fd1 and fd2 may be already another descriptors.
     * Not kernel problem.
     */

    err = put_user(fd1, &usockvec[0]);
    if (!err)
        err = put_user(fd2, &usockvec[1]);
    if (!err)
        return 0;

    sys_close(fd2);
    sys_close(fd1);
    return err;

out_release_both:
    sock_release(sock2);
out_release_1:
    sock_release(sock1);
out:
    return err;
}

/*
 *  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).
 */

SYSCALL_DEFINE3(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 >= 0) {
            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;
}

/*
 *  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.
 */

SYSCALL_DEFINE2(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 = 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;
}

/*
 *  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 restucture accept also.
 */

SYSCALL_DEFINE4(accept4, int, fd, struct sockaddr __user *, upeer_sockaddr,
        int __user *, upeer_addrlen, int, flags)
{
    struct socket *sock, *newsock;
    struct file *newfile;
    int err, len, newfd, fput_needed;
    struct sockaddr_storage address;

    if (flags & ~(SOCK_CLOEXEC | SOCK_NONBLOCK))
        return -EINVAL;

    if (SOCK_NONBLOCK != O_NONBLOCK && (flags & SOCK_NONBLOCK))
        flags = (flags & ~SOCK_NONBLOCK) | O_NONBLOCK;

    sock = sockfd_lookup_light(fd, &err, &fput_needed);
    if (!sock)
        goto out;

    err = -ENFILE;
    newsock = sock_alloc();
    if (!newsock)
        goto out_put;

    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);

    newfd = get_unused_fd_flags(flags);
    if (unlikely(newfd < 0)) {
        err = newfd;
        sock_release(newsock);
        goto out_put;
    }
    newfile = sock_alloc_file(newsock, flags, sock->sk->sk_prot_creator->name);
    if (unlikely(IS_ERR(newfile))) {
        err = PTR_ERR(newfile);
        put_unused_fd(newfd);
        sock_release(newsock);
        goto out_put;
    }

    err = security_socket_accept(sock, newsock);
    if (err)
        goto out_fd;

    err = sock->ops->accept(sock, newsock, sock->file->f_flags);
    if (err < 0)
        goto out_fd;

    if (upeer_sockaddr) {
        if (newsock->ops->getname(newsock, (struct sockaddr *)&address,
                      &len, 2) < 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. */

    fd_install(newfd, newfile);
    err = newfd;

out_put:
    fput_light(sock->file, fput_needed);
out:
    return err;
out_fd:
    fput(newfile);
    put_unused_fd(newfd);
    goto out_put;
}

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.
 */

SYSCALL_DEFINE3(connect, int, fd, struct sockaddr __user *, uservaddr,
        int, addrlen)
{
    struct socket *sock;
    struct sockaddr_storage address;
    int err, fput_needed;

    sock = sockfd_lookup_light(fd, &err, &fput_needed);
    if (!sock)
        goto out;
    err = move_addr_to_kernel(uservaddr, addrlen, &address);
    if (err < 0)
        goto out_put;

    err =
        security_socket_connect(sock, (struct sockaddr *)&address, addrlen);
    if (err)
        goto out_put;

    err = sock->ops->connect(sock, (struct sockaddr *)&address, addrlen,
                 sock->file->f_flags);
out_put:
    fput_light(sock->file, fput_needed);
out:
    return err;
}

/*
 *  Get the local address ('name') of a socket object. Move the obtained
 *  name to user space.
 */

SYSCALL_DEFINE3(getsockname, int, fd, struct sockaddr __user *, usockaddr,
        int __user *, usockaddr_len)
{
    struct socket *sock;
    struct sockaddr_storage address;
    int len, 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, &len, 0);
    if (err)
        goto out_put;
    err = move_addr_to_user(&address, len, usockaddr, usockaddr_len);

out_put:
    fput_light(sock->file, fput_needed);
out:
    return err;
}

/*
 *  Get the remote address ('name') of a socket object. Move the obtained
 *  name to user space.
 */

SYSCALL_DEFINE3(getpeername, int, fd, struct sockaddr __user *, usockaddr,
        int __user *, usockaddr_len)
{
    struct socket *sock;
    struct sockaddr_storage address;
    int len, 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, &len,
                       1);
        if (!err)
            err = move_addr_to_user(&address, len, usockaddr,
                        usockaddr_len);
        fput_light(sock->file, fput_needed);
    }
    return err;
}

/*
 *  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.
 */

SYSCALL_DEFINE6(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;

    if (len > INT_MAX)
        len = INT_MAX;
    sock = sockfd_lookup_light(fd, &err, &fput_needed);
    if (!sock)
        goto out;

    iov.iov_base = buff;
    iov.iov_len = len;
    msg.msg_name = NULL;
    msg.msg_iov = &iov;
    msg.msg_iovlen = 1;
    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, len);

out_put:
    fput_light(sock->file, fput_needed);
out:
    return err;
}

/*
 *  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.
 */

SYSCALL_DEFINE6(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;

    if (size > INT_MAX)
        size = INT_MAX;
    sock = sockfd_lookup_light(fd, &err, &fput_needed);
    if (!sock)
        goto out;

    msg.msg_control = NULL;
    msg.msg_controllen = 0;
    msg.msg_iovlen = 1;
    msg.msg_iov = &iov;
    iov.iov_len = size;
    iov.iov_base = ubuf;
    msg.msg_name = (struct sockaddr *)&address;
    msg.msg_namelen = sizeof(address);
    if (sock->file->f_flags & O_NONBLOCK)
        flags |= MSG_DONTWAIT;
    err = sock_recvmsg(sock, &msg, size, 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;
}

/*
 *  Receive a datagram from a socket.
 */

asmlinkage long sys_recv(int fd, void __user *ubuf, size_t size,
             unsigned int flags)
{
    return sys_recvfrom(fd, ubuf, size, flags, NULL, NULL);
}

/*
 *  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.
 */

SYSCALL_DEFINE5(setsockopt, int, fd, int, level, int, optname,
        char __user *, optval, int, optlen)
{
    int err, fput_needed;
    struct socket *sock;

    if (optlen < 0)
        return -EINVAL;

    sock = sockfd_lookup_light(fd, &err, &fput_needed);
    if (sock != NULL) {
        err = security_socket_setsockopt(sock, level, optname);
        if (err)
            goto out_put;

        if (level == SOL_SOCKET)
            err =
                sock_setsockopt(sock, level, optname, optval,
                        optlen);
        else
            err =
                sock->ops->setsockopt(sock, level, optname, optval,
                          optlen);
out_put:
        fput_light(sock->file, fput_needed);
    }
    return err;
}

/*
 *  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.
 */

SYSCALL_DEFINE5(getsockopt, int, fd, int, level, int, optname,
        char __user *, optval, int __user *, optlen)
{
    int err, fput_needed;
    struct socket *sock;

    sock = sockfd_lookup_light(fd, &err, &fput_needed);
    if (sock != NULL) {
        err = security_socket_getsockopt(sock, level, optname);
        if (err)
            goto out_put;

        if (level == SOL_SOCKET)
            err =
                sock_getsockopt(sock, level, optname, optval,
                        optlen);
        else
            err =
                sock->ops->getsockopt(sock, level, optname, optval,
                          optlen);
out_put:
        fput_light(sock->file, fput_needed);
    }
    return err;
}

/*
 *  Shutdown a socket.
 */

SYSCALL_DEFINE2(shutdown, int, fd, int, how)
{
    int err, fput_needed;
    struct socket *sock;

    sock = sockfd_lookup_light(fd, &err, &fput_needed);
    if (sock != NULL) {
        err = security_socket_shutdown(sock, how);
        if (!err)
            err = sock->ops->shutdown(sock, how);
        fput_light(sock->file, fput_needed);
    }
    return err;
}

/* 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;
};

static int __sys_sendmsg(struct socket *sock, struct msghdr __user *msg,
             struct msghdr *msg_sys, unsigned int flags,
             struct used_address *used_address)
{
    struct compat_msghdr __user *msg_compat =
        (struct compat_msghdr __user *)msg;
    struct sockaddr_storage address;
    struct iovec iovstack[UIO_FASTIOV], *iov = iovstack;
    unsigned char ctl[sizeof(struct cmsghdr) + 20]
        __attribute__ ((aligned(sizeof(__kernel_size_t))));
    /* 20 is size of ipv6_pktinfo */
    unsigned char *ctl_buf = ctl;
    int err, ctl_len, total_len;

    err = -EFAULT;
    if (MSG_CMSG_COMPAT & flags) {
        if (get_compat_msghdr(msg_sys, msg_compat))
            return -EFAULT;
    } else if (copy_from_user(msg_sys, msg, sizeof(struct msghdr)))
        return -EFAULT;

    if (msg_sys->msg_iovlen > UIO_FASTIOV) {
        err = -EMSGSIZE;
        if (msg_sys->msg_iovlen > UIO_MAXIOV)
            goto out;
        err = -ENOMEM;
        iov = kmalloc(msg_sys->msg_iovlen * sizeof(struct iovec),
                  GFP_KERNEL);
        if (!iov)
            goto out;
    }

    /* This will also move the address data into kernel space */
    if (MSG_CMSG_COMPAT & flags) {
        err = verify_compat_iovec(msg_sys, iov, &address, VERIFY_READ);
    } else
        err = verify_iovec(msg_sys, iov, &address, VERIFY_READ);
    if (err < 0)
        goto out_freeiov;
    total_len = err;

    err = -ENOBUFS;

    if (msg_sys->msg_controllen > INT_MAX)
        goto out_freeiov;
    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_freeiov;
        ctl_buf = msg_sys->msg_control;
        ctl_len = msg_sys->msg_controllen;
    } else if (ctl_len) {
        if (ctl_len > sizeof(ctl)) {
            ctl_buf = sock_kmalloc(sock->sk, ctl_len, GFP_KERNEL);
            if (ctl_buf == NULL)
                goto out_freeiov;
        }
        err = -EFAULT;
        /*
         * Careful! Before this, msg_sys->msg_control contains a user pointer.
         * Afterwards, it will be a kernel pointer. Thus the compiler-assisted
         * checking falls down on this.
         */
        if (copy_from_user(ctl_buf,
                   (void __user __force *)msg_sys->msg_control,
                   ctl_len))
            goto out_freectl;
        msg_sys->msg_control = ctl_buf;
    }
    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, total_len);
        goto out_freectl;
    }
    err = sock_sendmsg(sock, msg_sys, total_len);
    /*
     * 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_freeiov:
    if (iov != iovstack)
        kfree(iov);
out:
    return err;
}

/*
 *  BSD sendmsg interface
 */

SYSCALL_DEFINE3(sendmsg, int, fd, struct msghdr __user *, msg, unsigned int, flags)
{
    int fput_needed, err;
    struct msghdr msg_sys;
    struct socket *sock = sockfd_lookup_light(fd, &err, &fput_needed);

    if (!sock)
        goto out;

    err = __sys_sendmsg(sock, msg, &msg_sys, flags, NULL);

    fput_light(sock->file, fput_needed);
out:
    return err;
}

/*
 *  Linux sendmmsg interface
 */

int __sys_sendmmsg(int fd, struct mmsghdr __user *mmsg, unsigned int vlen,
           unsigned int flags)
{
    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;

    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;

    while (datagrams < vlen) {
        if (MSG_CMSG_COMPAT & flags) {
            err = __sys_sendmsg(sock, (struct msghdr __user *)compat_entry,
                        &msg_sys, flags, &used_address);
            if (err < 0)
                break;
            err = __put_user(err, &compat_entry->msg_len);
            ++compat_entry;
        } else {
            err = __sys_sendmsg(sock, (struct msghdr __user *)entry,
                        &msg_sys, flags, &used_address);
            if (err < 0)
                break;
            err = put_user(err, &entry->msg_len);
            ++entry;
        }

        if (err)
            break;
        ++datagrams;
    }

    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);
}

static int __sys_recvmsg(struct socket *sock, struct msghdr __user *msg,
             struct msghdr *msg_sys, unsigned int flags, int nosec)
{
    struct compat_msghdr __user *msg_compat =
        (struct compat_msghdr __user *)msg;
    struct iovec iovstack[UIO_FASTIOV];
    struct iovec *iov = iovstack;
    unsigned long cmsg_ptr;
    int err, total_len, len;

    /* kernel mode address */
    struct sockaddr_storage addr;

    /* user mode address pointers */
    struct sockaddr __user *uaddr;
    int __user *uaddr_len;

    if (MSG_CMSG_COMPAT & flags) {
        if (get_compat_msghdr(msg_sys, msg_compat))
            return -EFAULT;
    } else if (copy_from_user(msg_sys, msg, sizeof(struct msghdr)))
        return -EFAULT;

    if (msg_sys->msg_iovlen > UIO_FASTIOV) {
        err = -EMSGSIZE;
        if (msg_sys->msg_iovlen > UIO_MAXIOV)
            goto out;
        err = -ENOMEM;
        iov = kmalloc(msg_sys->msg_iovlen * sizeof(struct iovec),
                  GFP_KERNEL);
        if (!iov)
            goto out;
    }

    /*
     *      Save the user-mode address (verify_iovec will change the
     *      kernel msghdr to use the kernel address space)
     */

    uaddr = (__force void __user *)msg_sys->msg_name;
    uaddr_len = COMPAT_NAMELEN(msg);
    if (MSG_CMSG_COMPAT & flags) {
        err = verify_compat_iovec(msg_sys, iov, &addr, VERIFY_WRITE);
    } else
        err = verify_iovec(msg_sys, iov, &addr, VERIFY_WRITE);
    if (err < 0)
        goto out_freeiov;
    total_len = err;

    cmsg_ptr = (unsigned long)msg_sys->msg_control;
    msg_sys->msg_flags = flags & (MSG_CMSG_CLOEXEC|MSG_CMSG_COMPAT);

    if (sock->file->f_flags & O_NONBLOCK)
        flags |= MSG_DONTWAIT;
    err = (nosec ? sock_recvmsg_nosec : sock_recvmsg)(sock, msg_sys,
                              total_len, flags);
    if (err < 0)
        goto out_freeiov;
    len = err;

    if (uaddr != NULL) {
        err = move_addr_to_user(&addr,
                    msg_sys->msg_namelen, uaddr,
                    uaddr_len);
        if (err < 0)
            goto out_freeiov;
    }
    err = __put_user((msg_sys->msg_flags & ~MSG_CMSG_COMPAT),
             COMPAT_FLAGS(msg));
    if (err)
        goto out_freeiov;
    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_freeiov;
    err = len;

out_freeiov:
    if (iov != iovstack)
        kfree(iov);
out:
    return err;
}

/*
 *  BSD recvmsg interface
 */

SYSCALL_DEFINE3(recvmsg, int, fd, struct msghdr __user *, msg,
        unsigned int, flags)
{
    int fput_needed, err;
    struct msghdr msg_sys;
    struct socket *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;
}

/*
 *     Linux recvmmsg interface
 */

int __sys_recvmmsg(int fd, struct mmsghdr __user *mmsg, unsigned int vlen,
           unsigned int flags, struct timespec *timeout)
{
    int fput_needed, err, datagrams;
    struct socket *sock;
    struct mmsghdr __user *entry;
    struct compat_mmsghdr __user *compat_entry;
    struct msghdr msg_sys;
    struct timespec end_time;

    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;

    err = sock_error(sock->sk);
    if (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 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 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_ts(timeout);
            *timeout = timespec_sub(end_time, *timeout);
            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;
    }

out_put:
    fput_light(sock->file, fput_needed);

    if (err == 0)
        return datagrams;

    if (datagrams != 0) {
        /*
         * 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).
             */
            sock->sk->sk_err = -err;
        }

        return datagrams;
    }

    return err;
}

SYSCALL_DEFINE5(recvmmsg, int, fd, struct mmsghdr __user *, mmsg,
        unsigned int, vlen, unsigned int, flags,
        struct timespec __user *, timeout)
{
    int datagrams;
    struct timespec timeout_sys;

    if (!timeout)
        return __sys_recvmmsg(fd, mmsg, vlen, flags, NULL);

    if (copy_from_user(&timeout_sys, timeout, sizeof(timeout_sys)))
        return -EFAULT;

    datagrams = __sys_recvmmsg(fd, mmsg, vlen, flags, &timeout_sys);

    if (datagrams > 0 &&
        copy_to_user(timeout, &timeout_sys, sizeof(timeout_sys)))
        datagrams = -EFAULT;

    return datagrams;
}

#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[6];
    unsigned long a0, a1;
    int err;
    unsigned int len;

    if (call < 1 || call > SYS_SENDMMSG)
        return -EINVAL;

    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;

    audit_socketcall(nargs[call] / sizeof(unsigned long), a);

    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_send(a0, (void __user *)a1, a[2], a[3]);
        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_recv(a0, (void __user *)a1, a[2], a[3]);
        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 msghdr __user *)a1, a[2]);
        break;
    case SYS_SENDMMSG:
        err = sys_sendmmsg(a0, (struct mmsghdr __user *)a1, a[2], a[3]);
        break;
    case SYS_RECVMSG:
        err = sys_recvmsg(a0, (struct msghdr __user *)a1, a[2]);
        break;
    case SYS_RECVMMSG:
        err = sys_recvmmsg(a0, (struct mmsghdr __user *)a1, a[2], a[3],
                   (struct timespec __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 */

int sock_register(const struct net_proto_family *ops)
{
    int err;

    if (ops->family >= NPROTO) {
        printk(KERN_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);

    printk(KERN_INFO "NET: Registered protocol family %d\n", ops->family);
    return err;
}
EXPORT_SYMBOL(sock_register);

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();

    printk(KERN_INFO "NET: Unregistered protocol family %d\n", family);
}
EXPORT_SYMBOL(sock_unregister);

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_fs;
    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
    netfilter_init();
#endif

#ifdef CONFIG_NETWORK_PHY_TIMESTAMPING
    skb_timestamping_init();
#endif

out:
    return err;

out_mount:
    unregister_filesystem(&sock_fs_type);
out_fs:
    goto out;
}

core_initcall(sock_init);   /* early initcall */

#ifdef CONFIG_PROC_FS
void socket_seq_show(struct seq_file *seq)
{
    int cpu;
    int counter = 0;

    for_each_possible_cpu(cpu)
        counter += per_cpu(sockets_in_use, cpu);

    /* It can be negative, by the way. 8) */
    if (counter < 0)
        counter = 0;

    seq_printf(seq, "sockets: used %d\n", counter);
}
#endif              /* CONFIG_PROC_FS */

#ifdef CONFIG_COMPAT
static int do_siocgstamp(struct net *net, struct socket *sock,
             unsigned int cmd, void __user *up)
{
    mm_segment_t old_fs = get_fs();
    struct timeval ktv;
    int err;

    set_fs(KERNEL_DS);
    err = sock_do_ioctl(net, sock, cmd, (unsigned long)&ktv);
    set_fs(old_fs);
    if (!err)
        err = compat_put_timeval(&ktv, up);

    return err;
}

static int do_siocgstampns(struct net *net, struct socket *sock,
               unsigned int cmd, void __user *up)
{
    mm_segment_t old_fs = get_fs();
    struct timespec kts;
    int err;

    set_fs(KERNEL_DS);
    err = sock_do_ioctl(net, sock, cmd, (unsigned long)&kts);
    set_fs(old_fs);
    if (!err)
        err = compat_put_timespec(&kts, up);

    return err;
}

static int dev_ifname32(struct net *net, struct compat_ifreq __user *uifr32)
{
    struct ifreq __user *uifr;
    int err;

    uifr = compat_alloc_user_space(sizeof(struct ifreq));
    if (copy_in_user(uifr, uifr32, sizeof(struct compat_ifreq)))
        return -EFAULT;

    err = dev_ioctl(net, SIOCGIFNAME, uifr);
    if (err)
        return err;

    if (copy_in_user(uifr32, uifr, sizeof(struct compat_ifreq)))
        return -EFAULT;

    return 0;
}

static int dev_ifconf(struct net *net, struct compat_ifconf __user *uifc32)
{
    struct compat_ifconf ifc32;
    struct ifconf ifc;
    struct ifconf __user *uifc;
    struct compat_ifreq __user *ifr32;
    struct ifreq __user *ifr;
    unsigned int i, j;
    int err;

    if (copy_from_user(&ifc32, uifc32, sizeof(struct compat_ifconf)))
        return -EFAULT;

    memset(&ifc, 0, sizeof(ifc));
    if (ifc32.ifcbuf == 0) {
        ifc32.ifc_len = 0;
        ifc.ifc_len = 0;
        ifc.ifc_req = NULL;
        uifc = compat_alloc_user_space(sizeof(struct ifconf));
    } else {
        size_t len = ((ifc32.ifc_len / sizeof(struct compat_ifreq)) + 1) *
            sizeof(struct ifreq);
        uifc = compat_alloc_user_space(sizeof(struct ifconf) + len);
        ifc.ifc_len = len;
        ifr = ifc.ifc_req = (void __user *)(uifc + 1);
        ifr32 = compat_ptr(ifc32.ifcbuf);
        for (i = 0; i < ifc32.ifc_len; i += sizeof(struct compat_ifreq)) {
            if (copy_in_user(ifr, ifr32, sizeof(struct compat_ifreq)))
                return -EFAULT;
            ifr++;
            ifr32++;
        }
    }
    if (copy_to_user(uifc, &ifc, sizeof(struct ifconf)))
        return -EFAULT;

    err = dev_ioctl(net, SIOCGIFCONF, uifc);
    if (err)
        return err;

    if (copy_from_user(&ifc, uifc, sizeof(struct ifconf)))
        return -EFAULT;

    ifr = ifc.ifc_req;
    ifr32 = compat_ptr(ifc32.ifcbuf);
    for (i = 0, j = 0;
         i + sizeof(struct compat_ifreq) <= ifc32.ifc_len && j < ifc.ifc_len;
         i += sizeof(struct compat_ifreq), j += sizeof(struct ifreq)) {
        if (copy_in_user(ifr32, ifr, sizeof(struct compat_ifreq)))
            return -EFAULT;
        ifr32++;
        ifr++;
    }

    if (ifc32.ifcbuf == 0) {
        /* Translate from 64-bit structure multiple to
         * a 32-bit one.
         */
        i = ifc.ifc_len;
        i = ((i / sizeof(struct ifreq)) * sizeof(struct compat_ifreq));
        ifc32.ifc_len = i;
    } else {
        ifc32.ifc_len = i;
    }
    if (copy_to_user(uifc32, &ifc32, sizeof(struct compat_ifconf)))
        return -EFAULT;

    return 0;
}

static int ethtool_ioctl(struct net *net, struct compat_ifreq __user *ifr32)
{
    struct compat_ethtool_rxnfc __user *compat_rxnfc;
    bool convert_in = false, convert_out = false;
    size_t buf_size = ALIGN(sizeof(struct ifreq), 8);
    struct ethtool_rxnfc __user *rxnfc;
    struct ifreq __user *ifr;
    u32 rule_cnt = 0, actual_rule_cnt;
    u32 ethcmd;
    u32 data;
    int ret;

    if (get_user(data, &ifr32->ifr_ifru.ifru_data))
        return -EFAULT;

    compat_rxnfc = compat_ptr(data);

    if (get_user(ethcmd, &compat_rxnfc->cmd))
        return -EFAULT;

    /* Most ethtool structures are defined without padding.
     * Unfortunately struct ethtool_rxnfc is an exception.
     */
    switch (ethcmd) {
    default:
        break;
    case ETHTOOL_GRXCLSRLALL:
        /* Buffer size is variable */
        if (get_user(rule_cnt, &compat_rxnfc->rule_cnt))
            return -EFAULT;
        if (rule_cnt > KMALLOC_MAX_SIZE / sizeof(u32))
            return -ENOMEM;
        buf_size += rule_cnt * sizeof(u32);
        /* fall through */
    case ETHTOOL_GRXRINGS:
    case ETHTOOL_GRXCLSRLCNT:
    case ETHTOOL_GRXCLSRULE:
    case ETHTOOL_SRXCLSRLINS:
        convert_out = true;
        /* fall through */
    case ETHTOOL_SRXCLSRLDEL:
        buf_size += sizeof(struct ethtool_rxnfc);
        convert_in = true;
        break;
    }

    ifr = compat_alloc_user_space(buf_size);
    rxnfc = (void *)ifr + ALIGN(sizeof(struct ifreq), 8);

    if (copy_in_user(&ifr->ifr_name, &ifr32->ifr_name, IFNAMSIZ))
        return -EFAULT;

    if (put_user(convert_in ? rxnfc : compat_ptr(data),
             &ifr->ifr_ifru.ifru_data))
        return -EFAULT;

    if (convert_in) {
        /* We expect there to be holes between fs.m_ext and
         * fs.ring_cookie and at the end of fs, but nowhere else.
         */
        BUILD_BUG_ON(offsetof(struct compat_ethtool_rxnfc, fs.m_ext) +
                 sizeof(compat_rxnfc->fs.m_ext) !=
                 offsetof(struct ethtool_rxnfc, fs.m_ext) +
                 sizeof(rxnfc->fs.m_ext));
        BUILD_BUG_ON(
            offsetof(struct compat_ethtool_rxnfc, fs.location) -
            offsetof(struct compat_ethtool_rxnfc, fs.ring_cookie) !=
            offsetof(struct ethtool_rxnfc, fs.location) -
            offsetof(struct ethtool_rxnfc, fs.ring_cookie));

        if (copy_in_user(rxnfc, compat_rxnfc,
                 (void *)(&rxnfc->fs.m_ext + 1) -
                 (void *)rxnfc) ||
            copy_in_user(&rxnfc->fs.ring_cookie,
                 &compat_rxnfc->fs.ring_cookie,
                 (void *)(&rxnfc->fs.location + 1) -
                 (void *)&rxnfc->fs.ring_cookie) ||
            copy_in_user(&rxnfc->rule_cnt, &compat_rxnfc->rule_cnt,
                 sizeof(rxnfc->rule_cnt)))
            return -EFAULT;
    }

    ret = dev_ioctl(net, SIOCETHTOOL, ifr);
    if (ret)
        return ret;

    if (convert_out) {
        if (copy_in_user(compat_rxnfc, rxnfc,
                 (const void *)(&rxnfc->fs.m_ext + 1) -
                 (const void *)rxnfc) ||
            copy_in_user(&compat_rxnfc->fs.ring_cookie,
                 &rxnfc->fs.ring_cookie,
                 (const void *)(&rxnfc->fs.location + 1) -
                 (const void *)&rxnfc->fs.ring_cookie) ||
            copy_in_user(&compat_rxnfc->rule_cnt, &rxnfc->rule_cnt,
                 sizeof(rxnfc->rule_cnt)))
            return -EFAULT;

        if (ethcmd == ETHTOOL_GRXCLSRLALL) {
            /* As an optimisation, we only copy the actual
             * number of rules that the underlying
             * function returned.  Since Mallory might
             * change the rule count in user memory, we
             * check that it is less than the rule count
             * originally given (as the user buffer size),
             * which has been range-checked.
             */
            if (get_user(actual_rule_cnt, &rxnfc->rule_cnt))
                return -EFAULT;
            if (actual_rule_cnt < rule_cnt)
                rule_cnt = actual_rule_cnt;
            if (copy_in_user(&compat_rxnfc->rule_locs[0],
                     &rxnfc->rule_locs[0],
                     rule_cnt * sizeof(u32)))
                return -EFAULT;
        }
    }

    return 0;
}

static int compat_siocwandev(struct net *net, struct compat_ifreq __user *uifr32)
{
    void __user *uptr;
    compat_uptr_t uptr32;
    struct ifreq __user *uifr;

    uifr = compat_alloc_user_space(sizeof(*uifr));
    if (copy_in_user(uifr, uifr32, sizeof(struct compat_ifreq)))
        return -EFAULT;

    if (get_user(uptr32, &uifr32->ifr_settings.ifs_ifsu))
        return -EFAULT;

    uptr = compat_ptr(uptr32);

    if (put_user(uptr, &uifr->ifr_settings.ifs_ifsu.raw_hdlc))
        return -EFAULT;

    return dev_ioctl(net, SIOCWANDEV, uifr);
}

static int bond_ioctl(struct net *net, unsigned int cmd,
             struct compat_ifreq __user *ifr32)
{
    struct ifreq kifr;
    struct ifreq __user *uifr;
    mm_segment_t old_fs;
    int err;
    u32 data;
    void __user *datap;

    switch (cmd) {
    case SIOCBONDENSLAVE:
    case SIOCBONDRELEASE:
    case SIOCBONDSETHWADDR:
    case SIOCBONDCHANGEACTIVE:
        if (copy_from_user(&kifr, ifr32, sizeof(struct compat_ifreq)))
            return -EFAULT;

        old_fs = get_fs();
        set_fs(KERNEL_DS);
        err = dev_ioctl(net, cmd,
                (struct ifreq __user __force *) &kifr);
        set_fs(old_fs);

        return err;
    case SIOCBONDSLAVEINFOQUERY:
    case SIOCBONDINFOQUERY:
        uifr = compat_alloc_user_space(sizeof(*uifr));
        if (copy_in_user(&uifr->ifr_name, &ifr32->ifr_name, IFNAMSIZ))
            return -EFAULT;

        if (get_user(data, &ifr32->ifr_ifru.ifru_data))
            return -EFAULT;

        datap = compat_ptr(data);
        if (put_user(datap, &uifr->ifr_ifru.ifru_data))
            return -EFAULT;

        return dev_ioctl(net, cmd, uifr);
    default:
        return -ENOIOCTLCMD;
    }
}

static int siocdevprivate_ioctl(struct net *net, unsigned int cmd,
                 struct compat_ifreq __user *u_ifreq32)
{
    struct ifreq __user *u_ifreq64;
    char tmp_buf[IFNAMSIZ];
    void __user *data64;
    u32 data32;

    if (copy_from_user(&tmp_buf[0], &(u_ifreq32->ifr_ifrn.ifrn_name[0]),
               IFNAMSIZ))
        return -EFAULT;
    if (__get_user(data32, &u_ifreq32->ifr_ifru.ifru_data))
        return -EFAULT;
    data64 = compat_ptr(data32);

    u_ifreq64 = compat_alloc_user_space(sizeof(*u_ifreq64));

    /* Don't check these user accesses, just let that get trapped
     * in the ioctl handler instead.
     */
    if (copy_to_user(&u_ifreq64->ifr_ifrn.ifrn_name[0], &tmp_buf[0],
             IFNAMSIZ))
        return -EFAULT;
    if (__put_user(data64, &u_ifreq64->ifr_ifru.ifru_data))
        return -EFAULT;

    return dev_ioctl(net, cmd, u_ifreq64);
}

static int dev_ifsioc(struct net *net, struct socket *sock,
             unsigned int cmd, struct compat_ifreq __user *uifr32)
{
    struct ifreq __user *uifr;
    int err;

    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:
            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;
    mm_segment_t old_fs;
    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;

    old_fs = get_fs();
    set_fs(KERNEL_DS);
    err = dev_ioctl(net, cmd, (void  __user __force *)&ifr);
    set_fs(old_fs);

    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;
}

static int compat_siocshwtstamp(struct net *net, struct compat_ifreq __user *uifr32)
{
    void __user *uptr;
    compat_uptr_t uptr32;
    struct ifreq __user *uifr;

    uifr = compat_alloc_user_space(sizeof(*uifr));
    if (copy_in_user(uifr, uifr32, sizeof(struct compat_ifreq)))
        return -EFAULT;

    if (get_user(uptr32, &uifr32->ifr_data))
        return -EFAULT;

    uptr = compat_ptr(uptr32);

    if (put_user(uptr, &uifr->ifr_data))
        return -EFAULT;

    return dev_ioctl(net, SIOCSHWTSTAMP, uifr);
}

struct rtentry32 {
    u32     rt_pad1;
    struct sockaddr rt_dst;         /* target address               */
    struct sockaddr rt_gateway;     /* gateway addr (RTF_GATEWAY)   */
    struct sockaddr rt_genmask;     /* target network mask (IP)     */
    unsigned short  rt_flags;
    short       rt_pad2;
    u32     rt_pad3;
    unsigned char   rt_tos;
    unsigned char   rt_class;
    short       rt_pad4;
    short       rt_metric;      /* +1 for binary compatibility! */
    /* char * */ u32 rt_dev;        /* forcing the device at add    */
    u32     rt_mtu;         /* per route MTU/Window         */
    u32     rt_window;      /* Window clamping              */
    unsigned short  rt_irtt;        /* Initial RTT                  */
};

struct in6_rtmsg32 {
    struct in6_addr     rtmsg_dst;
    struct in6_addr     rtmsg_src;
    struct in6_addr     rtmsg_gateway;
    u32         rtmsg_type;
    u16         rtmsg_dst_len;
    u16         rtmsg_src_len;
    u32         rtmsg_metric;
    u32         rtmsg_info;
    u32         rtmsg_flags;
    s32         rtmsg_ifindex;
};

static int routing_ioctl(struct net *net, struct socket *sock,
             unsigned int cmd, void __user *argp)
{
    int ret;
    void *r = NULL;
    struct in6_rtmsg r6;
    struct rtentry r4;
    char devname[16];
    u32 rtdev;
    mm_segment_t old_fs = get_fs();

    if (sock && sock->sk && sock->sk->sk_family == AF_INET6) { /* ipv6 */
        struct in6_rtmsg32 __user *ur6 = argp;
        ret = copy_from_user(&r6.rtmsg_dst, &(ur6->rtmsg_dst),
            3 * sizeof(struct in6_addr));
        ret |= __get_user(r6.rtmsg_type, &(ur6->rtmsg_type));
        ret |= __get_user(r6.rtmsg_dst_len, &(ur6->rtmsg_dst_len));
        ret |= __get_user(r6.rtmsg_src_len, &(ur6->rtmsg_src_len));
        ret |= __get_user(r6.rtmsg_metric, &(ur6->rtmsg_metric));
        ret |= __get_user(r6.rtmsg_info, &(ur6->rtmsg_info));
        ret |= __get_user(r6.rtmsg_flags, &(ur6->rtmsg_flags));
        ret |= __get_user(r6.rtmsg_ifindex, &(ur6->rtmsg_ifindex));

        r = (void *) &r6;
    } else { /* ipv4 */
        struct rtentry32 __user *ur4 = argp;
        ret = copy_from_user(&r4.rt_dst, &(ur4->rt_dst),
                    3 * sizeof(struct sockaddr));
        ret |= __get_user(r4.rt_flags, &(ur4->rt_flags));
        ret |= __get_user(r4.rt_metric, &(ur4->rt_metric));
        ret |= __get_user(r4.rt_mtu, &(ur4->rt_mtu));
        ret |= __get_user(r4.rt_window, &(ur4->rt_window));
        ret |= __get_user(r4.rt_irtt, &(ur4->rt_irtt));
        ret |= __get_user(rtdev, &(ur4->rt_dev));
        if (rtdev) {
            ret |= copy_from_user(devname, compat_ptr(rtdev), 15);
            r4.rt_dev = (char __user __force *)devname;
            devname[15] = 0;
        } else
            r4.rt_dev = NULL;

        r = (void *) &r4;
    }

    if (ret) {
        ret = -EFAULT;
        goto out;
    }

    set_fs(KERNEL_DS);
    ret = sock_do_ioctl(net, sock, cmd, (unsigned long) r);
    set_fs(old_fs);

out:
    return ret;
}

/* 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 siocdevprivate_ioctl(net, cmd, argp);

    switch (cmd) {
    case SIOCSIFBR:
    case SIOCGIFBR:
        return old_bridge_ioctl(argp);
    case SIOCGIFNAME:
        return dev_ifname32(net, argp);
    case SIOCGIFCONF:
        return dev_ifconf(net, argp);
    case SIOCETHTOOL:
        return ethtool_ioctl(net, argp);
    case SIOCWANDEV:
        return compat_siocwandev(net, argp);
    case SIOCGIFMAP:
    case SIOCSIFMAP:
        return compat_sioc_ifmap(net, cmd, argp);
    case SIOCBONDENSLAVE:
    case SIOCBONDRELEASE:
    case SIOCBONDSETHWADDR:
    case SIOCBONDSLAVEINFOQUERY:
    case SIOCBONDINFOQUERY:
    case SIOCBONDCHANGEACTIVE:
        return bond_ioctl(net, cmd, argp);
    case SIOCADDRT:
    case SIOCDELRT:
        return routing_ioctl(net, sock, cmd, argp);
    case SIOCGSTAMP:
        return do_siocgstamp(net, sock, cmd, argp);
    case SIOCGSTAMPNS:
        return do_siocgstampns(net, sock, cmd, argp);
    case SIOCSHWTSTAMP:
        return compat_siocshwtstamp(net, argp);

    case FIOSETOWN:
    case SIOCSPGRP:
    case FIOGETOWN:
    case SIOCGPGRP:
    case SIOCBRADDBR:
    case SIOCBRDELBR:
    case SIOCGIFVLAN:
    case SIOCSIFVLAN:
    case SIOCADDDLCI:
    case SIOCDELDLCI:
        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 SIOCSIFNAME:
    case SIOCGMIIPHY:
    case SIOCGMIIREG:
    case SIOCSMIIREG:
        return dev_ifsioc(net, sock, cmd, argp);

    case SIOCSARP:
    case SIOCGARP:
    case SIOCDARP:
    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

int kernel_bind(struct socket *sock, struct sockaddr *addr, int addrlen)
{
    return sock->ops->bind(sock, addr, addrlen);
}
EXPORT_SYMBOL(kernel_bind);

int kernel_listen(struct socket *sock, int backlog)
{
    return sock->ops->listen(sock, backlog);
}
EXPORT_SYMBOL(kernel_listen);

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);
    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);

int kernel_connect(struct socket *sock, struct sockaddr *addr, int addrlen,
           int flags)
{
    return sock->ops->connect(sock, addr, addrlen, flags);
}
EXPORT_SYMBOL(kernel_connect);

int kernel_getsockname(struct socket *sock, struct sockaddr *addr,
             int *addrlen)
{
    return sock->ops->getname(sock, addr, addrlen, 0);
}
EXPORT_SYMBOL(kernel_getsockname);

int kernel_getpeername(struct socket *sock, struct sockaddr *addr,
             int *addrlen)
{
    return sock->ops->getname(sock, addr, addrlen, 1);
}
EXPORT_SYMBOL(kernel_getpeername);

int kernel_getsockopt(struct socket *sock, int level, int optname,
            char *optval, int *optlen)
{
    mm_segment_t oldfs = get_fs();
    char __user *uoptval;
    int __user *uoptlen;
    int err;

    uoptval = (char __user __force *) optval;
    uoptlen = (int __user __force *) optlen;

    set_fs(KERNEL_DS);
    if (level == SOL_SOCKET)
        err = sock_getsockopt(sock, level, optname, uoptval, uoptlen);
    else
        err = sock->ops->getsockopt(sock, level, optname, uoptval,
                        uoptlen);
    set_fs(oldfs);
    return err;
}
EXPORT_SYMBOL(kernel_getsockopt);

int kernel_setsockopt(struct socket *sock, int level, int optname,
            char *optval, unsigned int optlen)
{
    mm_segment_t oldfs = get_fs();
    char __user *uoptval;
    int err;

    uoptval = (char __user __force *) optval;

    set_fs(KERNEL_DS);
    if (level == SOL_SOCKET)
        err = sock_setsockopt(sock, level, optname, uoptval, optlen);
    else
        err = sock->ops->setsockopt(sock, level, optname, uoptval,
                        optlen);
    set_fs(oldfs);
    return err;
}
EXPORT_SYMBOL(kernel_setsockopt);

int kernel_sendpage(struct socket *sock, struct page *page, int offset,
            size_t size, int flags)
{
    sock_update_classid(sock->sk);

    if (sock->ops->sendpage)
        return sock->ops->sendpage(sock, page, offset, size, flags);

    return sock_no_sendpage(sock, page, offset, size, flags);
}
EXPORT_SYMBOL(kernel_sendpage);

int kernel_sock_ioctl(struct socket *sock, int cmd, unsigned long arg)
{
    mm_segment_t oldfs = get_fs();
    int err;

    set_fs(KERNEL_DS);
    err = sock->ops->ioctl(sock, cmd, arg);
    set_fs(oldfs);

    return err;
}
EXPORT_SYMBOL(kernel_sock_ioctl);

int kernel_sock_shutdown(struct socket *sock, enum sock_shutdown_cmd how)
{
    return sock->ops->shutdown(sock, how);
}
EXPORT_SYMBOL(kernel_sock_shutdown);