nr_route.c

linux 内核源代码

}

/*
 *	A device has been removed. Remove its routes and neighbours.
 */
void nr_rt_device_down(struct net_device *dev)
{
	struct nr_neigh *s;
	struct hlist_node *node, *nodet, *node2, *node2t;
	struct nr_node  *t;
	int i;

	spin_lock_bh(&nr_neigh_list_lock);
	nr_neigh_for_each_safe(s, node, nodet, &nr_neigh_list) {
		if (s->dev == dev) {
			spin_lock_bh(&nr_node_list_lock);
			nr_node_for_each_safe(t, node2, node2t, &nr_node_list) {
				nr_node_lock(t);
				for (i = 0; i < t->count; i++) {
					if (t->routes[i].neighbour == s) {
						t->count--;

						switch (i) {
						case 0:
							t->routes[0] = t->routes[1];
						case 1:
							t->routes[1] = t->routes[2];
						case 2:
							break;
						}
					}
				}

				if (t->count <= 0)
					nr_remove_node_locked(t);
				nr_node_unlock(t);
			}
			spin_unlock_bh(&nr_node_list_lock);

			nr_remove_neigh_locked(s);
		}
	}
	spin_unlock_bh(&nr_neigh_list_lock);
}

/*
 *	Check that the device given is a valid AX.25 interface that is "up".
 *	Or a valid ethernet interface with an AX.25 callsign binding.
 */
static struct net_device *nr_ax25_dev_get(char *devname)
{
	struct net_device *dev;

	if ((dev = dev_get_by_name(&init_net, devname)) == NULL)
		return NULL;

	if ((dev->flags & IFF_UP) && dev->type == ARPHRD_AX25)
		return dev;

	dev_put(dev);
	return NULL;
}

/*
 *	Find the first active NET/ROM device, usually "nr0".
 */
struct net_device *nr_dev_first(void)
{
	struct net_device *dev, *first = NULL;

	read_lock(&dev_base_lock);
	for_each_netdev(&init_net, dev) {
		if ((dev->flags & IFF_UP) && dev->type == ARPHRD_NETROM)
			if (first == NULL || strncmp(dev->name, first->name, 3) < 0)
				first = dev;
	}
	if (first)
		dev_hold(first);
	read_unlock(&dev_base_lock);

	return first;
}

/*
 *	Find the NET/ROM device for the given callsign.
 */
struct net_device *nr_dev_get(ax25_address *addr)
{
	struct net_device *dev;

	read_lock(&dev_base_lock);
	for_each_netdev(&init_net, dev) {
		if ((dev->flags & IFF_UP) && dev->type == ARPHRD_NETROM && ax25cmp(addr, (ax25_address *)dev->dev_addr) == 0) {
			dev_hold(dev);
			goto out;
		}
	}
	dev = NULL;
out:
	read_unlock(&dev_base_lock);
	return dev;
}

static ax25_digi *nr_call_to_digi(int ndigis, ax25_address *digipeaters)
{
	static ax25_digi ax25_digi;
	int i;

	if (ndigis == 0)
		return NULL;

	for (i = 0; i < ndigis; i++) {
		ax25_digi.calls[i]    = digipeaters[i];
		ax25_digi.repeated[i] = 0;
	}

	ax25_digi.ndigi      = ndigis;
	ax25_digi.lastrepeat = -1;

	return &ax25_digi;
}

/*
 *	Handle the ioctls that control the routing functions.
 */
int nr_rt_ioctl(unsigned int cmd, void __user *arg)
{
	struct nr_route_struct nr_route;
	struct net_device *dev;
	int ret;

	switch (cmd) {
	case SIOCADDRT:
		if (copy_from_user(&nr_route, arg, sizeof(struct nr_route_struct)))
			return -EFAULT;
		if ((dev = nr_ax25_dev_get(nr_route.device)) == NULL)
			return -EINVAL;
		if (nr_route.ndigis < 0 || nr_route.ndigis > AX25_MAX_DIGIS) {
			dev_put(dev);
			return -EINVAL;
		}
		switch (nr_route.type) {
		case NETROM_NODE:
			ret = nr_add_node(&nr_route.callsign,
				nr_route.mnemonic,
				&nr_route.neighbour,
				nr_call_to_digi(nr_route.ndigis, nr_route.digipeaters),
				dev, nr_route.quality,
				nr_route.obs_count);
			break;
		case NETROM_NEIGH:
			ret = nr_add_neigh(&nr_route.callsign,
				nr_call_to_digi(nr_route.ndigis, nr_route.digipeaters),
				dev, nr_route.quality);
			break;
		default:
			ret = -EINVAL;
		}
		dev_put(dev);
		return ret;

	case SIOCDELRT:
		if (copy_from_user(&nr_route, arg, sizeof(struct nr_route_struct)))
			return -EFAULT;
		if ((dev = nr_ax25_dev_get(nr_route.device)) == NULL)
			return -EINVAL;
		switch (nr_route.type) {
		case NETROM_NODE:
			ret = nr_del_node(&nr_route.callsign,
				&nr_route.neighbour, dev);
			break;
		case NETROM_NEIGH:
			ret = nr_del_neigh(&nr_route.callsign,
				dev, nr_route.quality);
			break;
		default:
			ret = -EINVAL;
		}
		dev_put(dev);
		return ret;

	case SIOCNRDECOBS:
		return nr_dec_obs();

	default:
		return -EINVAL;
	}

	return 0;
}

/*
 * 	A level 2 link has timed out, therefore it appears to be a poor link,
 *	then don't use that neighbour until it is reset.
 */
void nr_link_failed(ax25_cb *ax25, int reason)
{
	struct nr_neigh *s, *nr_neigh = NULL;
	struct hlist_node *node;
	struct nr_node  *nr_node = NULL;

	spin_lock_bh(&nr_neigh_list_lock);
	nr_neigh_for_each(s, node, &nr_neigh_list) {
		if (s->ax25 == ax25) {
			nr_neigh_hold(s);
			nr_neigh = s;
			break;
		}
	}
	spin_unlock_bh(&nr_neigh_list_lock);

	if (nr_neigh == NULL)
		return;

	nr_neigh->ax25 = NULL;
	ax25_cb_put(ax25);

	if (++nr_neigh->failed < sysctl_netrom_link_fails_count) {
		nr_neigh_put(nr_neigh);
		return;
	}
	spin_lock_bh(&nr_node_list_lock);
	nr_node_for_each(nr_node, node, &nr_node_list) {
		nr_node_lock(nr_node);
		if (nr_node->which < nr_node->count &&
		    nr_node->routes[nr_node->which].neighbour == nr_neigh)
			nr_node->which++;
		nr_node_unlock(nr_node);
	}
	spin_unlock_bh(&nr_node_list_lock);
	nr_neigh_put(nr_neigh);
}

/*
 *	Route a frame to an appropriate AX.25 connection. A NULL ax25_cb
 *	indicates an internally generated frame.
 */
int nr_route_frame(struct sk_buff *skb, ax25_cb *ax25)
{
	ax25_address *nr_src, *nr_dest;
	struct nr_neigh *nr_neigh;
	struct nr_node  *nr_node;
	struct net_device *dev;
	unsigned char *dptr;
	ax25_cb *ax25s;
	int ret;
	struct sk_buff *skbn;


	nr_src  = (ax25_address *)(skb->data + 0);
	nr_dest = (ax25_address *)(skb->data + 7);

	if (ax25 != NULL) {
		ret = nr_add_node(nr_src, "", &ax25->dest_addr, ax25->digipeat,
				  ax25->ax25_dev->dev, 0,
				  sysctl_netrom_obsolescence_count_initialiser);
		if (ret)
			return ret;
	}

	if ((dev = nr_dev_get(nr_dest)) != NULL) {	/* Its for me */
		if (ax25 == NULL)			/* Its from me */
			ret = nr_loopback_queue(skb);
		else
			ret = nr_rx_frame(skb, dev);
		dev_put(dev);
		return ret;
	}

	if (!sysctl_netrom_routing_control && ax25 != NULL)
		return 0;

	/* Its Time-To-Live has expired */
	if (skb->data[14] == 1) {
		return 0;
	}

	nr_node = nr_node_get(nr_dest);
	if (nr_node == NULL)
		return 0;
	nr_node_lock(nr_node);

	if (nr_node->which >= nr_node->count) {
		nr_node_unlock(nr_node);
		nr_node_put(nr_node);
		return 0;
	}

	nr_neigh = nr_node->routes[nr_node->which].neighbour;

	if ((dev = nr_dev_first()) == NULL) {
		nr_node_unlock(nr_node);
		nr_node_put(nr_node);
		return 0;
	}

	/* We are going to change the netrom headers so we should get our
	   own skb, we also did not know until now how much header space
	   we had to reserve... - RXQ */
	if ((skbn=skb_copy_expand(skb, dev->hard_header_len, 0, GFP_ATOMIC)) == NULL) {
		nr_node_unlock(nr_node);
		nr_node_put(nr_node);
		dev_put(dev);
		return 0;
	}
	kfree_skb(skb);
	skb=skbn;
	skb->data[14]--;

	dptr  = skb_push(skb, 1);
	*dptr = AX25_P_NETROM;

	ax25s = ax25_send_frame(skb, 256, (ax25_address *)dev->dev_addr, &nr_neigh->callsign, nr_neigh->digipeat, nr_neigh->dev);
	if (nr_neigh->ax25 && ax25s) {
		/* We were already holding this ax25_cb */
		ax25_cb_put(ax25s);
	}
	nr_neigh->ax25 = ax25s;

	dev_put(dev);
	ret = (nr_neigh->ax25 != NULL);
	nr_node_unlock(nr_node);
	nr_node_put(nr_node);

	return ret;
}

#ifdef CONFIG_PROC_FS

static void *nr_node_start(struct seq_file *seq, loff_t *pos)
{
	struct nr_node *nr_node;
	struct hlist_node *node;
	int i = 1;

	spin_lock_bh(&nr_node_list_lock);
	if (*pos == 0)
		return SEQ_START_TOKEN;

	nr_node_for_each(nr_node, node, &nr_node_list) {
		if (i == *pos)
			return nr_node;
		++i;
	}

	return NULL;
}

static void *nr_node_next(struct seq_file *seq, void *v, loff_t *pos)
{
	struct hlist_node *node;
	++*pos;

	node = (v == SEQ_START_TOKEN)
		? nr_node_list.first
		: ((struct nr_node *)v)->node_node.next;

	return hlist_entry(node, struct nr_node, node_node);
}

static void nr_node_stop(struct seq_file *seq, void *v)
{
	spin_unlock_bh(&nr_node_list_lock);
}

static int nr_node_show(struct seq_file *seq, void *v)
{
	char buf[11];
	int i;

	if (v == SEQ_START_TOKEN)
		seq_puts(seq,
			 "callsign  mnemonic w n qual obs neigh qual obs neigh qual obs neigh\n");
	else {
		struct nr_node *nr_node = v;
		nr_node_lock(nr_node);
		seq_printf(seq, "%-9s %-7s  %d %d",
			ax2asc(buf, &nr_node->callsign),
			(nr_node->mnemonic[0] == '\0') ? "*" : nr_node->mnemonic,
			nr_node->which + 1,
			nr_node->count);

		for (i = 0; i < nr_node->count; i++) {
			seq_printf(seq, "  %3d   %d %05d",
				nr_node->routes[i].quality,
				nr_node->routes[i].obs_count,
				nr_node->routes[i].neighbour->number);
		}
		nr_node_unlock(nr_node);

		seq_puts(seq, "\n");
	}
	return 0;
}

static const struct seq_operations nr_node_seqops = {
	.start = nr_node_start,
	.next = nr_node_next,
	.stop = nr_node_stop,
	.show = nr_node_show,
};

static int nr_node_info_open(struct inode *inode, struct file *file)
{
	return seq_open(file, &nr_node_seqops);
}

const struct file_operations nr_nodes_fops = {
	.owner = THIS_MODULE,
	.open = nr_node_info_open,
	.read = seq_read,
	.llseek = seq_lseek,
	.release = seq_release,
};

static void *nr_neigh_start(struct seq_file *seq, loff_t *pos)
{
	struct nr_neigh *nr_neigh;
	struct hlist_node *node;
	int i = 1;

	spin_lock_bh(&nr_neigh_list_lock);
	if (*pos == 0)
		return SEQ_START_TOKEN;

	nr_neigh_for_each(nr_neigh, node, &nr_neigh_list) {
		if (i == *pos)
			return nr_neigh;
	}
	return NULL;
}

static void *nr_neigh_next(struct seq_file *seq, void *v, loff_t *pos)
{
	struct hlist_node *node;
	++*pos;

	node = (v == SEQ_START_TOKEN)
		? nr_neigh_list.first
		: ((struct nr_neigh *)v)->neigh_node.next;

	return hlist_entry(node, struct nr_neigh, neigh_node);
}

static void nr_neigh_stop(struct seq_file *seq, void *v)
{
	spin_unlock_bh(&nr_neigh_list_lock);
}

static int nr_neigh_show(struct seq_file *seq, void *v)
{
	char buf[11];
	int i;

	if (v == SEQ_START_TOKEN)
		seq_puts(seq, "addr  callsign  dev  qual lock count failed digipeaters\n");
	else {
		struct nr_neigh *nr_neigh = v;

		seq_printf(seq, "%05d %-9s %-4s  %3d    %d   %3d    %3d",
			nr_neigh->number,
			ax2asc(buf, &nr_neigh->callsign),
			nr_neigh->dev ? nr_neigh->dev->name : "???",
			nr_neigh->quality,
			nr_neigh->locked,
			nr_neigh->count,
			nr_neigh->failed);

		if (nr_neigh->digipeat != NULL) {
			for (i = 0; i < nr_neigh->digipeat->ndigi; i++)
				seq_printf(seq, " %s",
					   ax2asc(buf, &nr_neigh->digipeat->calls[i]));
		}

		seq_puts(seq, "\n");
	}
	return 0;
}

static const struct seq_operations nr_neigh_seqops = {
	.start = nr_neigh_start,
	.next = nr_neigh_next,
	.stop = nr_neigh_stop,
	.show = nr_neigh_show,
};

static int nr_neigh_info_open(struct inode *inode, struct file *file)
{
	return seq_open(file, &nr_neigh_seqops);
}

const struct file_operations nr_neigh_fops = {
	.owner = THIS_MODULE,
	.open = nr_neigh_info_open,
	.read = seq_read,
	.llseek = seq_lseek,
	.release = seq_release,
};

#endif

/*
 *	Free all memory associated with the nodes and routes lists.
 */
void __exit nr_rt_free(void)
{
	struct nr_neigh *s = NULL;
	struct nr_node  *t = NULL;
	struct hlist_node *node, *nodet;

	spin_lock_bh(&nr_neigh_list_lock);
	spin_lock_bh(&nr_node_list_lock);
	nr_node_for_each_safe(t, node, nodet, &nr_node_list) {
		nr_node_lock(t);
		nr_remove_node_locked(t);
		nr_node_unlock(t);
	}
	nr_neigh_for_each_safe(s, node, nodet, &nr_neigh_list) {
		while(s->count) {
			s->count--;
			nr_neigh_put(s);
		}
		nr_remove_neigh_locked(s);
	}
	spin_unlock_bh(&nr_node_list_lock);
	spin_unlock_bh(&nr_neigh_list_lock);
}