patch-2.1.68 linux/net/netlink/netlink_dev.c

• Lines: 214
• Date: Sun Nov 30 14:00:40 1997
• Orig file: v2.1.67/linux/net/netlink/netlink_dev.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.1.67/linux/net/netlink/netlink_dev.c linux/net/netlink/netlink_dev.c
@@ -0,0 +1,213 @@
+/*
+ * NETLINK	An implementation of a loadable kernel mode driver providing
+ *		multiple kernel/user space bidirectional communications links.
+ *
+ * 		Author: 	Alan Cox <alan@cymru.net>
+ *
+ *		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/malloc.h>
+#include <linux/skbuff.h>
+#include <linux/netlink.h>
+#include <linux/poll.h>
+#include <linux/init.h>
+
+#include <asm/system.h>
+#include <asm/uaccess.h>
+
+static unsigned open_map = 0;
+static struct socket *netlink_user[MAX_LINKS];
+
+/*
+ *	Device operations
+ */
+ 
+static unsigned int netlink_poll(struct file *file, poll_table * wait)
+{
+	struct socket *sock = netlink_user[MINOR(file->f_dentry->d_inode->i_rdev)];
+
+	if (sock->ops->poll==NULL)
+		return 0;
+	return sock->ops->poll(sock, wait);
+}
+
+/*
+ *	Write a message to the kernel side of a communication link
+ */
+ 
+static ssize_t netlink_write(struct file * file, const char * buf,
+			     size_t count, loff_t *pos)
+{
+	struct inode *inode = file->f_dentry->d_inode;
+	struct socket *sock = netlink_user[MINOR(inode->i_rdev)];
+	struct msghdr msg;
+	struct iovec iov;
+
+	iov.iov_base = (void*)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 * buf,
+			    size_t count, loff_t *pos)
+{
+	struct inode *inode = file->f_dentry->d_inode;
+	struct socket *sock = netlink_user[MINOR(inode->i_rdev)];
+	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 loff_t netlink_lseek(struct file * file, loff_t offset, int origin)
+{
+	return -ESPIPE;
+}
+
+static int netlink_open(struct inode * inode, struct file * file)
+{
+	unsigned int minor = MINOR(inode->i_rdev);
+	struct socket *sock;
+	struct sockaddr_nl nladdr;
+	int err;
+	
+	if (minor>=MAX_LINKS)
+		return -ENODEV;
+	if (open_map&(1<<minor))
+		return -EBUSY;
+
+	open_map |= (1<<minor);
+	MOD_INC_USE_COUNT;
+	
+	err = -EINVAL;
+	if (net_families[AF_NETLINK]==NULL)
+  		goto out;
+
+	err = -ENFILE;
+	if (!(sock = sock_alloc())) 
+		goto out;
+
+	sock->type = SOCK_RAW;
+
+	if ((err = net_families[AF_NETLINK]->create(sock, minor)) < 0) 
+	{
+		sock_release(sock);
+		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:
+	open_map &= ~(1<<minor);
+	return err;
+}
+
+static int netlink_release(struct inode * inode, struct file * file)
+{
+	unsigned int minor = MINOR(inode->i_rdev);
+	struct socket *sock = netlink_user[minor];
+
+	netlink_user[minor] = NULL;
+	open_map &= ~(1<<minor);
+	sock_release(sock);
+	MOD_DEC_USE_COUNT;
+	return 0;
+}
+
+
+static int netlink_ioctl(struct inode *inode, struct file *file,
+		    unsigned int cmd, unsigned long arg)
+{
+	unsigned int minor = MINOR(inode->i_rdev);
+	int retval = 0;
+
+	if (minor >= MAX_LINKS)
+		return -ENODEV;
+	switch ( cmd ) {
+		default:
+			retval = -EINVAL;
+	}
+	return retval;
+}
+
+
+static struct file_operations netlink_fops = {
+	netlink_lseek,
+	netlink_read,
+	netlink_write,
+	NULL,		/* netlink_readdir */
+	netlink_poll,
+	netlink_ioctl,
+	NULL,		/* netlink_mmap */
+	netlink_open,
+	netlink_release
+};
+
+__initfunc(int init_netlink(void))
+{
+	if (register_chrdev(NETLINK_MAJOR,"netlink", &netlink_fops)) {
+		printk(KERN_ERR "netlink: unable to get major %d\n", NETLINK_MAJOR);
+		return -EIO;
+	}
+	return 0;
+}
+
+#ifdef MODULE
+
+int init_module(void)
+{
+	printk(KERN_INFO "Network Kernel/User communications module 0.04\n");
+	return init_netlink();
+}
+
+void cleanup_module(void)
+{
+	unregister_chrdev(NET_MAJOR,"netlink");
+}
+
+#endif