blob: 59f53de4b86bf88d5f163237ffb99aae08106bcc [file] [log] [blame]
/*
* NETLINK An implementation of a loadable kernel mode driver providing
* multiple kernel/user space bidirectional communications links.
*
* Author: Alan Cox <alan@redhat.com>
*
* 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.
*
* Now netlink devices are emulated on the top of netlink sockets
* by compatibility reasons. Remove this file after a period. --ANK
*
*/
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/major.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/skbuff.h>
#include <linux/netlink.h>
#include <linux/poll.h>
#include <linux/init.h>
#include <linux/devfs_fs_kernel.h>
#include <linux/smp_lock.h>
#include <linux/device.h>
#include <linux/bitops.h>
#include <asm/system.h>
#include <asm/uaccess.h>
static long open_map;
static struct socket *netlink_user[MAX_LINKS];
static struct class_simple *netlink_class;
/*
* Device operations
*/
static unsigned int netlink_poll(struct file *file, poll_table * wait)
{
struct socket *sock = netlink_user[iminor(file->f_dentry->d_inode)];
if (sock->ops->poll==NULL)
return 0;
return sock->ops->poll(file, sock, wait);
}
/*
* Write a message to the kernel side of a communication link
*/
static ssize_t netlink_write(struct file * file, const char __user * buf,
size_t count, loff_t *pos)
{
struct inode *inode = file->f_dentry->d_inode;
struct socket *sock = netlink_user[iminor(inode)];
struct msghdr msg;
struct iovec iov;
iov.iov_base = (void __user*)buf;
iov.iov_len = count;
msg.msg_name=NULL;
msg.msg_namelen=0;
msg.msg_controllen=0;
msg.msg_flags=0;
msg.msg_iov=&iov;
msg.msg_iovlen=1;
return sock_sendmsg(sock, &msg, count);
}
/*
* Read a message from the kernel side of the communication link
*/
static ssize_t netlink_read(struct file * file, char __user * buf,
size_t count, loff_t *pos)
{
struct inode *inode = file->f_dentry->d_inode;
struct socket *sock = netlink_user[iminor(inode)];
struct msghdr msg;
struct iovec iov;
iov.iov_base = buf;
iov.iov_len = count;
msg.msg_name=NULL;
msg.msg_namelen=0;
msg.msg_controllen=0;
msg.msg_flags=0;
msg.msg_iov=&iov;
msg.msg_iovlen=1;
if (file->f_flags&O_NONBLOCK)
msg.msg_flags=MSG_DONTWAIT;
return sock_recvmsg(sock, &msg, count, msg.msg_flags);
}
static int netlink_open(struct inode * inode, struct file * file)
{
unsigned int minor = iminor(inode);
struct socket *sock;
struct sockaddr_nl nladdr;
int err;
if (minor>=MAX_LINKS)
return -ENODEV;
if (test_and_set_bit(minor, &open_map))
return -EBUSY;
err = sock_create_kern(PF_NETLINK, SOCK_RAW, minor, &sock);
if (err < 0)
goto out;
memset(&nladdr, 0, sizeof(nladdr));
nladdr.nl_family = AF_NETLINK;
nladdr.nl_groups = ~0;
if ((err = sock->ops->bind(sock, (struct sockaddr*)&nladdr, sizeof(nladdr))) < 0) {
sock_release(sock);
goto out;
}
netlink_user[minor] = sock;
return 0;
out:
clear_bit(minor, &open_map);
return err;
}
static int netlink_release(struct inode * inode, struct file * file)
{
unsigned int minor = iminor(inode);
struct socket *sock;
sock = netlink_user[minor];
netlink_user[minor] = NULL;
clear_bit(minor, &open_map);
sock_release(sock);
return 0;
}
static int netlink_ioctl(struct inode *inode, struct file *file,
unsigned int cmd, unsigned long arg)
{
unsigned int minor = iminor(inode);
int retval = 0;
if (minor >= MAX_LINKS)
return -ENODEV;
switch ( cmd ) {
default:
retval = -EINVAL;
}
return retval;
}
static struct file_operations netlink_fops = {
.owner = THIS_MODULE,
.llseek = no_llseek,
.read = netlink_read,
.write = netlink_write,
.poll = netlink_poll,
.ioctl = netlink_ioctl,
.open = netlink_open,
.release = netlink_release,
};
static struct {
char *name;
int minor;
} entries[] = {
{
.name = "route",
.minor = NETLINK_ROUTE,
},
{
.name = "skip",
.minor = NETLINK_SKIP,
},
{
.name = "usersock",
.minor = NETLINK_USERSOCK,
},
{
.name = "fwmonitor",
.minor = NETLINK_FIREWALL,
},
{
.name = "tcpdiag",
.minor = NETLINK_TCPDIAG,
},
{
.name = "nflog",
.minor = NETLINK_NFLOG,
},
{
.name = "xfrm",
.minor = NETLINK_XFRM,
},
{
.name = "arpd",
.minor = NETLINK_ARPD,
},
{
.name = "route6",
.minor = NETLINK_ROUTE6,
},
{
.name = "ip6_fw",
.minor = NETLINK_IP6_FW,
},
{
.name = "dnrtmsg",
.minor = NETLINK_DNRTMSG,
},
};
static int __init init_netlink(void)
{
int i;
if (register_chrdev(NETLINK_MAJOR,"netlink", &netlink_fops)) {
printk(KERN_ERR "netlink: unable to get major %d\n", NETLINK_MAJOR);
return -EIO;
}
netlink_class = class_simple_create(THIS_MODULE, "netlink");
if (IS_ERR(netlink_class)) {
printk (KERN_ERR "Error creating netlink class.\n");
unregister_chrdev(NETLINK_MAJOR, "netlink");
return PTR_ERR(netlink_class);
}
devfs_mk_dir("netlink");
/* Someone tell me the official names for the uppercase ones */
for (i = 0; i < ARRAY_SIZE(entries); i++) {
devfs_mk_cdev(MKDEV(NETLINK_MAJOR, entries[i].minor),
S_IFCHR|S_IRUSR|S_IWUSR, "netlink/%s", entries[i].name);
class_simple_device_add(netlink_class, MKDEV(NETLINK_MAJOR, entries[i].minor), NULL, "%s", entries[i].name);
}
for (i = 0; i < 16; i++) {
devfs_mk_cdev(MKDEV(NETLINK_MAJOR, i + 16),
S_IFCHR|S_IRUSR|S_IWUSR, "netlink/tap%d", i);
class_simple_device_add(netlink_class, MKDEV(NETLINK_MAJOR, i + 16), NULL, "tap%d", i);
}
return 0;
}
static void __exit cleanup_netlink(void)
{
int i;
for (i = 0; i < ARRAY_SIZE(entries); i++) {
devfs_remove("netlink/%s", entries[i].name);
class_simple_device_remove(MKDEV(NETLINK_MAJOR, entries[i].minor));
}
for (i = 0; i < 16; i++) {
devfs_remove("netlink/tap%d", i);
class_simple_device_remove(MKDEV(NETLINK_MAJOR, i + 16));
}
devfs_remove("netlink");
class_simple_destroy(netlink_class);
unregister_chrdev(NETLINK_MAJOR, "netlink");
}
MODULE_LICENSE("GPL");
module_init(init_netlink);
module_exit(cleanup_netlink);