279 lines
6.0 KiB
C
279 lines
6.0 KiB
C
/*
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* NETLINK An implementation of a loadable kernel mode driver providing
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* multiple kernel/user space bidirectional communications links.
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*
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* Author: Alan Cox <alan@redhat.com>
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*
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* Now netlink devices are emulated on the top of netlink sockets
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* by compatibility reasons. Remove this file after a period. --ANK
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*
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*/
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#include <linux/module.h>
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#include <linux/errno.h>
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#include <linux/kernel.h>
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#include <linux/major.h>
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#include <linux/sched.h>
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#include <linux/slab.h>
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#include <linux/skbuff.h>
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#include <linux/netlink.h>
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#include <linux/poll.h>
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#include <linux/init.h>
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#include <linux/devfs_fs_kernel.h>
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#include <linux/smp_lock.h>
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#include <linux/device.h>
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#include <linux/bitops.h>
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#include <asm/system.h>
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#include <asm/uaccess.h>
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static long open_map;
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static struct socket *netlink_user[MAX_LINKS];
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static struct class_simple *netlink_class;
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/*
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* Device operations
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*/
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static unsigned int netlink_poll(struct file *file, poll_table * wait)
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{
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struct socket *sock = netlink_user[iminor(file->f_dentry->d_inode)];
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if (sock->ops->poll==NULL)
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return 0;
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return sock->ops->poll(file, sock, wait);
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}
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/*
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* Write a message to the kernel side of a communication link
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*/
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static ssize_t netlink_write(struct file * file, const char __user * buf,
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size_t count, loff_t *pos)
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{
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struct inode *inode = file->f_dentry->d_inode;
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struct socket *sock = netlink_user[iminor(inode)];
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struct msghdr msg;
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struct iovec iov;
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iov.iov_base = (void __user*)buf;
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iov.iov_len = count;
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msg.msg_name=NULL;
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msg.msg_namelen=0;
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msg.msg_controllen=0;
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msg.msg_flags=0;
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msg.msg_iov=&iov;
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msg.msg_iovlen=1;
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return sock_sendmsg(sock, &msg, count);
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}
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/*
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* Read a message from the kernel side of the communication link
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*/
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static ssize_t netlink_read(struct file * file, char __user * buf,
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size_t count, loff_t *pos)
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{
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struct inode *inode = file->f_dentry->d_inode;
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struct socket *sock = netlink_user[iminor(inode)];
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struct msghdr msg;
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struct iovec iov;
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iov.iov_base = buf;
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iov.iov_len = count;
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msg.msg_name=NULL;
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msg.msg_namelen=0;
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msg.msg_controllen=0;
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msg.msg_flags=0;
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msg.msg_iov=&iov;
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msg.msg_iovlen=1;
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if (file->f_flags&O_NONBLOCK)
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msg.msg_flags=MSG_DONTWAIT;
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return sock_recvmsg(sock, &msg, count, msg.msg_flags);
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}
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static int netlink_open(struct inode * inode, struct file * file)
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{
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unsigned int minor = iminor(inode);
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struct socket *sock;
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struct sockaddr_nl nladdr;
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int err;
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if (minor>=MAX_LINKS)
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return -ENODEV;
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if (test_and_set_bit(minor, &open_map))
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return -EBUSY;
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err = sock_create_kern(PF_NETLINK, SOCK_RAW, minor, &sock);
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if (err < 0)
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goto out;
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memset(&nladdr, 0, sizeof(nladdr));
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nladdr.nl_family = AF_NETLINK;
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nladdr.nl_groups = ~0;
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if ((err = sock->ops->bind(sock, (struct sockaddr*)&nladdr, sizeof(nladdr))) < 0) {
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sock_release(sock);
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goto out;
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}
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netlink_user[minor] = sock;
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return 0;
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out:
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clear_bit(minor, &open_map);
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return err;
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}
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static int netlink_release(struct inode * inode, struct file * file)
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{
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unsigned int minor = iminor(inode);
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struct socket *sock;
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sock = netlink_user[minor];
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netlink_user[minor] = NULL;
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clear_bit(minor, &open_map);
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sock_release(sock);
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return 0;
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}
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static int netlink_ioctl(struct inode *inode, struct file *file,
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unsigned int cmd, unsigned long arg)
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{
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unsigned int minor = iminor(inode);
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int retval = 0;
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if (minor >= MAX_LINKS)
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return -ENODEV;
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switch ( cmd ) {
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default:
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retval = -EINVAL;
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}
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return retval;
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}
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static struct file_operations netlink_fops = {
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.owner = THIS_MODULE,
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.llseek = no_llseek,
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.read = netlink_read,
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.write = netlink_write,
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.poll = netlink_poll,
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.ioctl = netlink_ioctl,
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.open = netlink_open,
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.release = netlink_release,
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};
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static struct {
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char *name;
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int minor;
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} entries[] = {
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{
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.name = "route",
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.minor = NETLINK_ROUTE,
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},
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{
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.name = "skip",
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.minor = NETLINK_SKIP,
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},
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{
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.name = "usersock",
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.minor = NETLINK_USERSOCK,
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},
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{
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.name = "fwmonitor",
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.minor = NETLINK_FIREWALL,
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},
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{
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.name = "tcpdiag",
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.minor = NETLINK_TCPDIAG,
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},
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{
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.name = "nflog",
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.minor = NETLINK_NFLOG,
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},
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{
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.name = "xfrm",
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.minor = NETLINK_XFRM,
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},
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{
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.name = "arpd",
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.minor = NETLINK_ARPD,
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},
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{
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.name = "route6",
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.minor = NETLINK_ROUTE6,
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},
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{
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.name = "ip6_fw",
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.minor = NETLINK_IP6_FW,
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},
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{
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.name = "dnrtmsg",
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.minor = NETLINK_DNRTMSG,
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},
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};
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static int __init init_netlink(void)
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{
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int i;
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if (register_chrdev(NETLINK_MAJOR,"netlink", &netlink_fops)) {
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printk(KERN_ERR "netlink: unable to get major %d\n", NETLINK_MAJOR);
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return -EIO;
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}
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netlink_class = class_simple_create(THIS_MODULE, "netlink");
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if (IS_ERR(netlink_class)) {
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printk (KERN_ERR "Error creating netlink class.\n");
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unregister_chrdev(NETLINK_MAJOR, "netlink");
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return PTR_ERR(netlink_class);
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}
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devfs_mk_dir("netlink");
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/* Someone tell me the official names for the uppercase ones */
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for (i = 0; i < ARRAY_SIZE(entries); i++) {
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devfs_mk_cdev(MKDEV(NETLINK_MAJOR, entries[i].minor),
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S_IFCHR|S_IRUSR|S_IWUSR, "netlink/%s", entries[i].name);
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class_simple_device_add(netlink_class, MKDEV(NETLINK_MAJOR, entries[i].minor), NULL, "%s", entries[i].name);
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}
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for (i = 0; i < 16; i++) {
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devfs_mk_cdev(MKDEV(NETLINK_MAJOR, i + 16),
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S_IFCHR|S_IRUSR|S_IWUSR, "netlink/tap%d", i);
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class_simple_device_add(netlink_class, MKDEV(NETLINK_MAJOR, i + 16), NULL, "tap%d", i);
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}
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return 0;
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}
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static void __exit cleanup_netlink(void)
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{
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int i;
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for (i = 0; i < ARRAY_SIZE(entries); i++) {
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devfs_remove("netlink/%s", entries[i].name);
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class_simple_device_remove(MKDEV(NETLINK_MAJOR, entries[i].minor));
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}
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for (i = 0; i < 16; i++) {
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devfs_remove("netlink/tap%d", i);
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class_simple_device_remove(MKDEV(NETLINK_MAJOR, i + 16));
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}
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devfs_remove("netlink");
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class_simple_destroy(netlink_class);
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unregister_chrdev(NETLINK_MAJOR, "netlink");
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}
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MODULE_LICENSE("GPL");
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module_init(init_netlink);
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module_exit(cleanup_netlink);
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