rose_route.c

linux 内核源代码

/*
 * 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.
 *
 * Copyright (C) Jonathan Naylor G4KLX ([e-mail])
 * Copyright (C) Terry Dawson VK2KTJ ([e-mail])
 */
#include <linux/errno.h>
#include <linux/types.h>
#include <linux/socket.h>
#include <linux/in.h>
#include <linux/kernel.h>
#include <linux/timer.h>
#include <linux/string.h>
#include <linux/sockios.h>
#include <linux/net.h>
#include <net/ax25.h>
#include <linux/inet.h>
#include <linux/netdevice.h>
#include <net/arp.h>
#include <linux/if_arp.h>
#include <linux/skbuff.h>
#include <net/sock.h>
#include <net/tcp_states.h>
#include <asm/system.h>
#include <asm/uaccess.h>
#include <linux/fcntl.h>
#include <linux/termios.h>	/* For TIOCINQ/OUTQ */
#include <linux/mm.h>
#include <linux/interrupt.h>
#include <linux/notifier.h>
#include <linux/netfilter.h>
#include <linux/init.h>
#include <net/rose.h>
#include <linux/seq_file.h>

static unsigned int rose_neigh_no = 1;

static struct rose_node  *rose_node_list;
static DEFINE_SPINLOCK(rose_node_list_lock);
static struct rose_neigh *rose_neigh_list;
static DEFINE_SPINLOCK(rose_neigh_list_lock);
static struct rose_route *rose_route_list;
static DEFINE_SPINLOCK(rose_route_list_lock);

struct rose_neigh *rose_loopback_neigh;

/*
 *	Add a new route to a node, and in the process add the node and the
 *	neighbour if it is new.
 */
static int __must_check rose_add_node(struct rose_route_struct *rose_route,
	struct net_device *dev)
{
	struct rose_node  *rose_node, *rose_tmpn, *rose_tmpp;
	struct rose_neigh *rose_neigh;
	int i, res = 0;

	spin_lock_bh(&rose_node_list_lock);
	spin_lock_bh(&rose_neigh_list_lock);

	rose_node = rose_node_list;
	while (rose_node != NULL) {
		if ((rose_node->mask == rose_route->mask) &&
		    (rosecmpm(&rose_route->address, &rose_node->address,
			      rose_route->mask) == 0))
			break;
		rose_node = rose_node->next;
	}

	if (rose_node != NULL && rose_node->loopback) {
		res = -EINVAL;
		goto out;
	}

	rose_neigh = rose_neigh_list;
	while (rose_neigh != NULL) {
		if (ax25cmp(&rose_route->neighbour, &rose_neigh->callsign) == 0
		    && rose_neigh->dev == dev)
			break;
		rose_neigh = rose_neigh->next;
	}

	if (rose_neigh == NULL) {
		rose_neigh = kmalloc(sizeof(*rose_neigh), GFP_ATOMIC);
		if (rose_neigh == NULL) {
			res = -ENOMEM;
			goto out;
		}

		rose_neigh->callsign  = rose_route->neighbour;
		rose_neigh->digipeat  = NULL;
		rose_neigh->ax25      = NULL;
		rose_neigh->dev       = dev;
		rose_neigh->count     = 0;
		rose_neigh->use       = 0;
		rose_neigh->dce_mode  = 0;
		rose_neigh->loopback  = 0;
		rose_neigh->number    = rose_neigh_no++;
		rose_neigh->restarted = 0;

		skb_queue_head_init(&rose_neigh->queue);

		init_timer(&rose_neigh->ftimer);
		init_timer(&rose_neigh->t0timer);

		if (rose_route->ndigis != 0) {
			if ((rose_neigh->digipeat = kmalloc(sizeof(ax25_digi), GFP_KERNEL)) == NULL) {
				kfree(rose_neigh);
				res = -ENOMEM;
				goto out;
			}

			rose_neigh->digipeat->ndigi      = rose_route->ndigis;
			rose_neigh->digipeat->lastrepeat = -1;

			for (i = 0; i < rose_route->ndigis; i++) {
				rose_neigh->digipeat->calls[i]    =
					rose_route->digipeaters[i];
				rose_neigh->digipeat->repeated[i] = 0;
			}
		}

		rose_neigh->next = rose_neigh_list;
		rose_neigh_list  = rose_neigh;
	}

	/*
	 * This is a new node to be inserted into the list. Find where it needs
	 * to be inserted into the list, and insert it. We want to be sure
	 * to order the list in descending order of mask size to ensure that
	 * later when we are searching this list the first match will be the
	 * best match.
	 */
	if (rose_node == NULL) {
		rose_tmpn = rose_node_list;
		rose_tmpp = NULL;

		while (rose_tmpn != NULL) {
			if (rose_tmpn->mask > rose_route->mask) {
				rose_tmpp = rose_tmpn;
				rose_tmpn = rose_tmpn->next;
			} else {
				break;
			}
		}

		/* create new node */
		rose_node = kmalloc(sizeof(*rose_node), GFP_ATOMIC);
		if (rose_node == NULL) {
			res = -ENOMEM;
			goto out;
		}

		rose_node->address      = rose_route->address;
		rose_node->mask         = rose_route->mask;
		rose_node->count        = 1;
		rose_node->loopback     = 0;
		rose_node->neighbour[0] = rose_neigh;

		if (rose_tmpn == NULL) {
			if (rose_tmpp == NULL) {	/* Empty list */
				rose_node_list  = rose_node;
				rose_node->next = NULL;
			} else {
				rose_tmpp->next = rose_node;
				rose_node->next = NULL;
			}
		} else {
			if (rose_tmpp == NULL) {	/* 1st node */
				rose_node->next = rose_node_list;
				rose_node_list  = rose_node;
			} else {
				rose_tmpp->next = rose_node;
				rose_node->next = rose_tmpn;
			}
		}
		rose_neigh->count++;

		goto out;
	}

	/* We have space, slot it in */
	if (rose_node->count < 3) {
		rose_node->neighbour[rose_node->count] = rose_neigh;
		rose_node->count++;
		rose_neigh->count++;
	}

out:
	spin_unlock_bh(&rose_neigh_list_lock);
	spin_unlock_bh(&rose_node_list_lock);

	return res;
}

/*
 * Caller is holding rose_node_list_lock.
 */
static void rose_remove_node(struct rose_node *rose_node)
{
	struct rose_node *s;

	if ((s = rose_node_list) == rose_node) {
		rose_node_list = rose_node->next;
		kfree(rose_node);
		return;
	}

	while (s != NULL && s->next != NULL) {
		if (s->next == rose_node) {
			s->next = rose_node->next;
			kfree(rose_node);
			return;
		}

		s = s->next;
	}
}

/*
 * Caller is holding rose_neigh_list_lock.
 */
static void rose_remove_neigh(struct rose_neigh *rose_neigh)
{
	struct rose_neigh *s;

	rose_stop_ftimer(rose_neigh);
	rose_stop_t0timer(rose_neigh);

	skb_queue_purge(&rose_neigh->queue);

	if ((s = rose_neigh_list) == rose_neigh) {
		rose_neigh_list = rose_neigh->next;
		kfree(rose_neigh->digipeat);
		kfree(rose_neigh);
		return;
	}

	while (s != NULL && s->next != NULL) {
		if (s->next == rose_neigh) {
			s->next = rose_neigh->next;
			kfree(rose_neigh->digipeat);
			kfree(rose_neigh);
			return;
		}

		s = s->next;
	}
}

/*
 * Caller is holding rose_route_list_lock.
 */
static void rose_remove_route(struct rose_route *rose_route)
{
	struct rose_route *s;

	if (rose_route->neigh1 != NULL)
		rose_route->neigh1->use--;

	if (rose_route->neigh2 != NULL)
		rose_route->neigh2->use--;

	if ((s = rose_route_list) == rose_route) {
		rose_route_list = rose_route->next;
		kfree(rose_route);
		return;
	}

	while (s != NULL && s->next != NULL) {
		if (s->next == rose_route) {
			s->next = rose_route->next;
			kfree(rose_route);
			return;
		}

		s = s->next;
	}
}

/*
 *	"Delete" a node. Strictly speaking remove a route to a node. The node
 *	is only deleted if no routes are left to it.
 */
static int rose_del_node(struct rose_route_struct *rose_route,
	struct net_device *dev)
{
	struct rose_node  *rose_node;
	struct rose_neigh *rose_neigh;
	int i, err = 0;

	spin_lock_bh(&rose_node_list_lock);
	spin_lock_bh(&rose_neigh_list_lock);

	rose_node = rose_node_list;
	while (rose_node != NULL) {
		if ((rose_node->mask == rose_route->mask) &&
		    (rosecmpm(&rose_route->address, &rose_node->address,
			      rose_route->mask) == 0))
			break;
		rose_node = rose_node->next;
	}

	if (rose_node == NULL || rose_node->loopback) {
		err = -EINVAL;
		goto out;
	}

	rose_neigh = rose_neigh_list;
	while (rose_neigh != NULL) {
		if (ax25cmp(&rose_route->neighbour, &rose_neigh->callsign) == 0
		    && rose_neigh->dev == dev)
			break;
		rose_neigh = rose_neigh->next;
	}

	if (rose_neigh == NULL) {
		err = -EINVAL;
		goto out;
	}

	for (i = 0; i < rose_node->count; i++) {
		if (rose_node->neighbour[i] == rose_neigh) {
			rose_neigh->count--;

			if (rose_neigh->count == 0 && rose_neigh->use == 0)
				rose_remove_neigh(rose_neigh);

			rose_node->count--;

			if (rose_node->count == 0) {
				rose_remove_node(rose_node);
			} else {
				switch (i) {
				case 0:
					rose_node->neighbour[0] =
						rose_node->neighbour[1];
				case 1:
					rose_node->neighbour[1] =
						rose_node->neighbour[2];
				case 2:
					break;
				}
			}
			goto out;
		}
	}
	err = -EINVAL;

out:
	spin_unlock_bh(&rose_neigh_list_lock);
	spin_unlock_bh(&rose_node_list_lock);

	return err;
}

/*
 *	Add the loopback neighbour.
 */
void rose_add_loopback_neigh(void)
{
	struct rose_neigh *sn;

	rose_loopback_neigh = kmalloc(sizeof(struct rose_neigh), GFP_KERNEL);
	if (!rose_loopback_neigh)
		return;
	sn = rose_loopback_neigh;

	sn->callsign  = null_ax25_address;
	sn->digipeat  = NULL;
	sn->ax25      = NULL;
	sn->dev       = NULL;
	sn->count     = 0;
	sn->use       = 0;
	sn->dce_mode  = 1;
	sn->loopback  = 1;
	sn->number    = rose_neigh_no++;
	sn->restarted = 1;

	skb_queue_head_init(&sn->queue);

	init_timer(&sn->ftimer);
	init_timer(&sn->t0timer);

	spin_lock_bh(&rose_neigh_list_lock);
	sn->next = rose_neigh_list;
	rose_neigh_list           = sn;
	spin_unlock_bh(&rose_neigh_list_lock);
}

/*
 *	Add a loopback node.
 */
int rose_add_loopback_node(rose_address *address)
{
	struct rose_node *rose_node;
	int err = 0;

	spin_lock_bh(&rose_node_list_lock);

	rose_node = rose_node_list;
	while (rose_node != NULL) {
		if ((rose_node->mask == 10) &&
		     (rosecmpm(address, &rose_node->address, 10) == 0) &&
		     rose_node->loopback)
			break;
		rose_node = rose_node->next;
	}

	if (rose_node != NULL)
		goto out;

	if ((rose_node = kmalloc(sizeof(*rose_node), GFP_ATOMIC)) == NULL) {
		err = -ENOMEM;
		goto out;
	}

	rose_node->address      = *address;
	rose_node->mask         = 10;
	rose_node->count        = 1;
	rose_node->loopback     = 1;
	rose_node->neighbour[0] = rose_loopback_neigh;

	/* Insert at the head of list. Address is always mask=10 */
	rose_node->next = rose_node_list;
	rose_node_list  = rose_node;

	rose_loopback_neigh->count++;

out:
	spin_unlock_bh(&rose_node_list_lock);

	return err;
}

/*
 *	Delete a loopback node.
 */
void rose_del_loopback_node(rose_address *address)
{
	struct rose_node *rose_node;

	spin_lock_bh(&rose_node_list_lock);

	rose_node = rose_node_list;