patch-2.1.68 linux/net/netlink.c

• Lines: 476
• Date: Wed Dec 31 16:00:00 1969
• Orig file: v2.1.67/linux/net/netlink.c
• Orig date: Wed Nov 26 16:24:03 1997

diff -u --recursive --new-file v2.1.67/linux/net/netlink.c linux/net/netlink.c
@@ -1,475 +0,0 @@
-/*
- * 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.
- * 
- */
-
-#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/ioport.h>
-#include <linux/fcntl.h>
-#include <linux/delay.h>
-#include <linux/interrupt.h>
-#include <linux/skbuff.h>
-#include <linux/init.h>
-
-#include <net/netlink.h>
-
-#include <asm/poll.h>
-#include <asm/io.h>
-#include <asm/uaccess.h>
-#include <asm/system.h>
-
-static int (*netlink_handler[MAX_LINKS])(int minor, struct sk_buff *skb);
-static struct sk_buff_head skb_queue_rd[MAX_LINKS]; 
-static int rdq_size[MAX_LINKS];
-static struct wait_queue *read_space_wait[MAX_LINKS];
-
-static unsigned long active_map = 0;
-static unsigned long open_map = 0;
-
-/*
- *	Device operations
- */
- 
-/*
- *	Default write handler.
- */
- 
-static int netlink_err(int minor, struct sk_buff *skb)
-{
-	kfree_skb(skb, FREE_READ);
-	return -EUNATCH;
-}
-
-/*
- *	Exported do nothing receiver for one way
- *	interfaces.
- */
-  
-int netlink_donothing(int minor, struct sk_buff *skb)
-{
-	kfree_skb(skb, FREE_READ);
-	return -EINVAL;
-}
-
-static unsigned int netlink_poll(struct file *file, poll_table * wait)
-{
-	unsigned int mask;
-	unsigned int minor = MINOR(file->f_dentry->d_inode->i_rdev);
-
-	poll_wait(&read_space_wait[minor], wait);
-	mask = POLLOUT | POLLWRNORM;
-	if (skb_peek(&skb_queue_rd[minor]))
-		mask |= POLLIN | POLLRDNORM;
-	return mask;
-}
-
-/*
- *	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 *ppos)
-{
-	int err; 
-	unsigned int minor = MINOR(file->f_dentry->d_inode->i_rdev);
-	struct sk_buff *skb;
-	skb=alloc_skb(count, GFP_KERNEL);
-	err = copy_from_user(skb_put(skb,count),buf, count);
-	return err ? -EFAULT : (netlink_handler[minor])(minor,skb);
-}
-
-/*
- *	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 *ppos)
-{
-	int err; 
-	unsigned int minor = MINOR(file->f_dentry->d_inode->i_rdev);
-	struct sk_buff *skb;
-	cli();
-	while((skb=skb_dequeue(&skb_queue_rd[minor]))==NULL)
-	{
-		if(file->f_flags&O_NONBLOCK)
-		{
-			sti();
-			return -EAGAIN;
-		}
-		interruptible_sleep_on(&read_space_wait[minor]);
-		if(signal_pending(current))
-		{
-			sti();
-			return -ERESTARTSYS;
-		}
-	}
-	rdq_size[minor]-=skb->len;
-	sti();
-	if(skb->len<count)
-		count=skb->len;
-	err = copy_to_user(buf,skb->data,count);
-	kfree_skb(skb, FREE_READ);
-	return err ? -EFAULT : count;
-}
-
-static long long netlink_lseek(struct file * file, long long offset, int origin)
-{
-	return -ESPIPE;
-}
-
-static int netlink_open(struct inode * inode, struct file * file)
-{
-	unsigned int minor = MINOR(inode->i_rdev);
-	
-	if(minor>=MAX_LINKS)
-		return -ENODEV;
-	if(active_map&(1<<minor))
-	{
-		if (file->f_mode & FMODE_READ)
-		{
-			if (open_map&(1<<minor))
-				return -EBUSY;
-			open_map|=(1<<minor);
-		}
-		MOD_INC_USE_COUNT;
-		return 0;
-	}
-	return -EUNATCH;
-}
-
-static int netlink_release(struct inode * inode, struct file * file)
-{
-	unsigned int minor = MINOR(inode->i_rdev);
-	if (file->f_mode & FMODE_READ)
-		open_map&=~(1<<minor);
-	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
-};
-
-/*
- *	We export these functions to other modules. They provide a 
- *	complete set of kernel non-blocking support for message
- *	queueing.
- */
- 
-int netlink_attach(int unit, int (*function)(int minor, struct sk_buff *skb))
-{
-	if(unit>=MAX_LINKS)
-		return -ENODEV;
-	if(active_map&(1<<unit))
-		return -EBUSY;
-	active_map|=(1<<unit);
-	netlink_handler[unit]=function;
-	return 0;
-}
-
-void netlink_detach(int unit)
-{
-	active_map&=~(1<<unit);
-	netlink_handler[unit]=netlink_err;
-}
-
-int netlink_post(int unit, struct sk_buff *skb)
-{
-	unsigned long flags;
-	int ret=-EUNATCH;
-	if(open_map&(1<<unit))
-	{
-		save_flags(flags);
-		cli();
-		if(rdq_size[unit]+skb->len>MAX_QBYTES)
-			ret=-EAGAIN;
-		else
-		{	
-			skb_queue_tail(&skb_queue_rd[unit], skb);
-			rdq_size[unit]+=skb->len;
-			ret=0;
-			wake_up_interruptible(&read_space_wait[unit]);
-		}
-		restore_flags(flags);
-	}
-	return ret;
-}
-
-
-/*
- *	"High" level netlink interface. (ANK)
- *	
- *	Features:
- *		- standard message format.
- *		- pseudo-reliable delivery. Messages can be still lost, but
- *		  user level will know that they were lost and can
- *		  recover (f.e. gated could reread FIB and device list)
- *		- messages are batched.
- *		- if user is not attached, we do not make useless work.
- *
- *	Examples:
- *		- netlink_post equivalent (but with pseudo-reliable delivery)
- *			ctl.nlmsg_delay = 0;
- *			ctl.nlmsg_maxsize = <one message size>;
- *			....
- *			msg = nlmsg_send(&ctl, ...);
- *			if (msg) {
- *				... make it ...
- *				nlmsg_transmit(&ctl);
- *			}
- *
- *		- batched messages.
- *		  	if nlmsg_delay==0, messages are delivered only
- *			by nlmsg_transmit, or when batch is completed,
- *			otherwise nlmsg_transmit is noop (only starts
- *			timer)
- *
- *			ctl.nlmsg_delay = ...;
- *			ctl.nlmsg_maxsize = <one batch size>;
- *			....
- *			msg = nlmsg_send(&ctl, ...);
- *			if (msg)
- *				... make it ...
- *			....
- *			msg = nlmsg_send(&ctl, ...);
- *			if (msg)
- *				... make it ...
- *			....
- *			if (ctl.nlmsg_skb)
- *				nlmsg_transmit(&ctl);
- *
- */
-
-/*
- *	Try to deliver queued messages.
- *	If the delivery fails (netlink is not attached or congested),
- *	do not free skb to avoid useless new message creation.
- *
- *	Notes:
- *		- timer should be already stopped.
- *		- NET SPL.
- */
-
-void nlmsg_flush(struct nlmsg_ctl *ctl)
-{
-	if (ctl->nlmsg_skb == NULL)
-		return;
-
-	if (netlink_post(ctl->nlmsg_unit, ctl->nlmsg_skb) == 0)
-	{
-		ctl->nlmsg_skb = NULL;
-		return;
-	}
-
-	ctl->nlmsg_timer.expires = jiffies + NLMSG_RECOVERY_TIMEO;
-	ctl->nlmsg_timer.data = (unsigned long)ctl;
-	ctl->nlmsg_timer.function = (void (*)(unsigned long))nlmsg_flush;
-	add_timer(&ctl->nlmsg_timer);
-	return;
-}
-
-
-/*
- *	Allocate room for new message. If it is impossible,
- *	start "overrun" mode and return NULL.
- *
- *	Notes:
- *		- NET SPL.
- */
-
-void* nlmsg_send(struct nlmsg_ctl *ctl, unsigned long type, int len,
-		 unsigned long seq, unsigned long pid)
-{
-	struct nlmsghdr *nlh;
-	struct sk_buff *skb;
-	int	rlen;
-
-	static __inline__ void nlmsg_lost(struct nlmsg_ctl *ctl,
-					  unsigned long seq)
-	{
-		if (!ctl->nlmsg_overrun)
-		{
-			ctl->nlmsg_overrun_start = seq;
-			ctl->nlmsg_overrun_end = seq;
-			ctl->nlmsg_overrun = 1;
-			return;
-		}
-		if (!ctl->nlmsg_overrun_start)
-			ctl->nlmsg_overrun_start = seq;
-		if (seq)
-			ctl->nlmsg_overrun_end = seq;
-	}
-
-	if (!(open_map&(1<<ctl->nlmsg_unit)))
-	{
-		nlmsg_lost(ctl, seq);
-		return NULL;
-	}
-
-	rlen = NLMSG_ALIGN(len + sizeof(struct nlmsghdr));
-
-	if (rlen > ctl->nlmsg_maxsize)
-	{
-		printk(KERN_ERR "nlmsg_send: too big message\n");
-		return NULL;
-	}
-
-	if ((skb=ctl->nlmsg_skb) == NULL || skb_tailroom(skb) < rlen)
-	{
-		if (skb)
-		{
-			ctl->nlmsg_force++;
-			nlmsg_flush(ctl);
-			ctl->nlmsg_force--;
-		}
-
-		if (ctl->nlmsg_skb ||
-		    (skb=alloc_skb(ctl->nlmsg_maxsize, GFP_ATOMIC)) == NULL)
-		{
-			printk (KERN_WARNING "nlmsg at unit %d overrunned\n", ctl->nlmsg_unit);
-			nlmsg_lost(ctl, seq);
-			return NULL;
-		}
-
-		ctl->nlmsg_skb = skb;
-
-		if (ctl->nlmsg_overrun)
-		{
-			int *seqp;
-			nlh = (struct nlmsghdr*)skb_put(skb, sizeof(struct nlmsghdr) + 2*sizeof(unsigned long));
-			nlh->nlmsg_type = NLMSG_OVERRUN;
-			nlh->nlmsg_len = sizeof(struct nlmsghdr) + 2*sizeof(unsigned long);
-			nlh->nlmsg_seq = 0;
-			nlh->nlmsg_pid = 0;
-			seqp = (int*)nlh->nlmsg_data;
-			seqp[0] = ctl->nlmsg_overrun_start;
-			seqp[1] = ctl->nlmsg_overrun_end;
-			ctl->nlmsg_overrun = 0;
-		}
-		if (ctl->nlmsg_timer.function)
-		{
-			del_timer(&ctl->nlmsg_timer);
-			ctl->nlmsg_timer.function = NULL;
-		}
-		if (ctl->nlmsg_delay)
-		{
-			ctl->nlmsg_timer.expires = jiffies + ctl->nlmsg_delay;
-			ctl->nlmsg_timer.function = (void (*)(unsigned long))nlmsg_flush;
-			ctl->nlmsg_timer.data = (unsigned long)ctl;
-			add_timer(&ctl->nlmsg_timer);
-		}
-	}
-
-	nlh = (struct nlmsghdr*)skb_put(skb, rlen);
-	nlh->nlmsg_type = type;
-	nlh->nlmsg_len = sizeof(struct nlmsghdr) + len;
-	nlh->nlmsg_seq = seq;
-	nlh->nlmsg_pid = pid;
-	return nlh->nlmsg_data;
-}
-
-/*
- *	Kick message queue.
- *	Two modes:
- *		- synchronous (delay==0). Messages are delivered immediately.
- *		- delayed. Do not deliver, but start delivery timer.
- */
-
-void nlmsg_transmit(struct nlmsg_ctl *ctl)
-{
-	start_bh_atomic();
-
-	if (!ctl->nlmsg_delay)
-	{
-		if (ctl->nlmsg_timer.function)
-		{
-			del_timer(&ctl->nlmsg_timer);
-			ctl->nlmsg_timer.function = NULL;
-		}
-		ctl->nlmsg_force++;
-		nlmsg_flush(ctl);
-		ctl->nlmsg_force--;
-		end_bh_atomic();
-		return;
-	}
-	if (!ctl->nlmsg_timer.function)
-	{
-		ctl->nlmsg_timer.expires = jiffies + ctl->nlmsg_delay;
-		ctl->nlmsg_timer.function = (void (*)(unsigned long))nlmsg_flush;
-		ctl->nlmsg_timer.data = (unsigned long)ctl;
-		add_timer(&ctl->nlmsg_timer);
-	}
-
-	end_bh_atomic();
-}
-
-
-__initfunc(int init_netlink(void))
-{
-	int ct;
-
-	if(register_chrdev(NETLINK_MAJOR,"netlink", &netlink_fops)) {
-		printk(KERN_ERR "netlink: unable to get major %d\n", NETLINK_MAJOR);
-		return -EIO;
-	}
-	for(ct=0;ct<MAX_LINKS;ct++)
-	{
-		skb_queue_head_init(&skb_queue_rd[ct]);
-		netlink_handler[ct]=netlink_err;
-	}
-	return 0;
-}
-
-#ifdef MODULE
-
-int init_module(void)
-{
-	printk(KERN_INFO "Network Kernel/User communications module 0.05\n");
-	return init_netlink();
-}
-
-void cleanup_module(void)
-{
-	unregister_chrdev(NET_MAJOR,"netlink");
-}
-
-#endif