net/batman-adv/icmp_socket.c - linux - Git at Google

 /* Copyright (C) 2007-2013 B.A.T.M.A.N. contributors:
  *
  * Marek Lindner
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of version 2 of the GNU General Public
  * License as published by the Free Software Foundation.
  *
  * This program is distributed in the hope that it will be useful, but
  * WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  * General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with this program; if not, see <http://www.gnu.org/licenses/>.
  */

 #include "main.h"
 #include <linux/debugfs.h>
 #include <linux/slab.h>
 #include "icmp_socket.h"
 #include "send.h"
 #include "hash.h"
 #include "originator.h"
 #include "hard-interface.h"

 static struct batadv_socket_client *batadv_socket_client_hash[256];

 static void batadv_socket_add_packet(struct batadv_socket_client *socket_client,
 				     struct batadv_icmp_header *icmph,
 				     size_t icmp_len);

 void batadv_socket_init(void)
 {
 	memset(batadv_socket_client_hash, 0, sizeof(batadv_socket_client_hash));
 }

 static int batadv_socket_open(struct inode *inode, struct file *file)
 {
 	unsigned int i;
 	struct batadv_socket_client *socket_client;

 	if (!try_module_get(THIS_MODULE))
 		return -EBUSY;

 	nonseekable_open(inode, file);

 	socket_client = kmalloc(sizeof(*socket_client), GFP_KERNEL);
 	if (!socket_client) {
 		module_put(THIS_MODULE);
 		return -ENOMEM;
 	}

 	for (i = 0; i < ARRAY_SIZE(batadv_socket_client_hash); i++) {
 		if (!batadv_socket_client_hash[i]) {
 			batadv_socket_client_hash[i] = socket_client;
 			break;
 		}
 	}

 	if (i == ARRAY_SIZE(batadv_socket_client_hash)) {
 		pr_err("Error - can't add another packet client: maximum number of clients reached\n");
 		kfree(socket_client);
 		module_put(THIS_MODULE);
 		return -EXFULL;
 	}

 	INIT_LIST_HEAD(&socket_client->queue_list);
 	socket_client->queue_len = 0;
 	socket_client->index = i;
 	socket_client->bat_priv = inode->i_private;
 	spin_lock_init(&socket_client->lock);
 	init_waitqueue_head(&socket_client->queue_wait);

 	file->private_data = socket_client;

 	return 0;
 }

 static int batadv_socket_release(struct inode *inode, struct file *file)
 {
 	struct batadv_socket_client *socket_client = file->private_data;
 	struct batadv_socket_packet *socket_packet;
 	struct list_head *list_pos, *list_pos_tmp;

 	spin_lock_bh(&socket_client->lock);

 	/* for all packets in the queue ... */
 	list_for_each_safe(list_pos, list_pos_tmp, &socket_client->queue_list) {
 		socket_packet = list_entry(list_pos,
 					   struct batadv_socket_packet, list);

 		list_del(list_pos);
 		kfree(socket_packet);
 	}

 	batadv_socket_client_hash[socket_client->index] = NULL;
 	spin_unlock_bh(&socket_client->lock);

 	kfree(socket_client);
 	module_put(THIS_MODULE);

 	return 0;
 }

 static ssize_t batadv_socket_read(struct file *file, char __user *buf,
 				  size_t count, loff_t *ppos)
 {
 	struct batadv_socket_client *socket_client = file->private_data;
 	struct batadv_socket_packet *socket_packet;
 	size_t packet_len;
 	int error;

 	if ((file->f_flags & O_NONBLOCK) && (socket_client->queue_len == 0))
 		return -EAGAIN;

 	if ((!buf) || (count < sizeof(struct batadv_icmp_packet)))
 		return -EINVAL;

 	if (!access_ok(VERIFY_WRITE, buf, count))
 		return -EFAULT;

 	error = wait_event_interruptible(socket_client->queue_wait,
 					 socket_client->queue_len);

 	if (error)
 		return error;

 	spin_lock_bh(&socket_client->lock);

 	socket_packet = list_first_entry(&socket_client->queue_list,
 					 struct batadv_socket_packet, list);
 	list_del(&socket_packet->list);
 	socket_client->queue_len--;

 	spin_unlock_bh(&socket_client->lock);

 	packet_len = min(count, socket_packet->icmp_len);
 	error = copy_to_user(buf, &socket_packet->icmp_packet, packet_len);

 	kfree(socket_packet);

 	if (error)
 		return -EFAULT;

 	return packet_len;
 }

 static ssize_t batadv_socket_write(struct file *file, const char __user *buff,
 				   size_t len, loff_t *off)
 {
 	struct batadv_socket_client *socket_client = file->private_data;
 	struct batadv_priv *bat_priv = socket_client->bat_priv;
 	struct batadv_hard_iface *primary_if = NULL;
 	struct sk_buff *skb;
 	struct batadv_icmp_packet_rr *icmp_packet_rr;
 	struct batadv_icmp_header *icmp_header;
 	struct batadv_orig_node *orig_node = NULL;
 	struct batadv_neigh_node *neigh_node = NULL;
 	size_t packet_len = sizeof(struct batadv_icmp_packet);

 	if (len < sizeof(struct batadv_icmp_header)) {
 		batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 			   "Error - can't send packet from char device: invalid packet size\n");
 		return -EINVAL;
 	}

 	primary_if = batadv_primary_if_get_selected(bat_priv);

 	if (!primary_if) {
 		len = -EFAULT;
 		goto out;
 	}

 	if (len >= BATADV_ICMP_MAX_PACKET_SIZE)
 		packet_len = BATADV_ICMP_MAX_PACKET_SIZE;
 	else
 		packet_len = len;

 	skb = netdev_alloc_skb_ip_align(NULL, packet_len + ETH_HLEN);
 	if (!skb) {
 		len = -ENOMEM;
 		goto out;
 	}

 	skb->priority = TC_PRIO_CONTROL;
 	skb_reserve(skb, ETH_HLEN);
 	icmp_header = (struct batadv_icmp_header *)skb_put(skb, packet_len);

 	if (copy_from_user(icmp_header, buff, packet_len)) {
 		len = -EFAULT;
 		goto free_skb;
 	}

 	if (icmp_header->packet_type != BATADV_ICMP) {
 		batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 			   "Error - can't send packet from char device: got bogus packet type (expected: BAT_ICMP)\n");
 		len = -EINVAL;
 		goto free_skb;
 	}

 	switch (icmp_header->msg_type) {
 	case BATADV_ECHO_REQUEST:
 		if (len < sizeof(struct batadv_icmp_packet)) {
 			batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 				   "Error - can't send packet from char device: invalid packet size\n");
 			len = -EINVAL;
 			goto free_skb;
 		}

 		if (atomic_read(&bat_priv->mesh_state) != BATADV_MESH_ACTIVE)
 			goto dst_unreach;

 		orig_node = batadv_orig_hash_find(bat_priv, icmp_header->dst);
 		if (!orig_node)
 			goto dst_unreach;

 		neigh_node = batadv_orig_node_get_router(orig_node);
 		if (!neigh_node)
 			goto dst_unreach;

 		if (!neigh_node->if_incoming)
 			goto dst_unreach;

 		if (neigh_node->if_incoming->if_status != BATADV_IF_ACTIVE)
 			goto dst_unreach;

 		icmp_packet_rr = (struct batadv_icmp_packet_rr *)icmp_header;
 		if (packet_len == sizeof(*icmp_packet_rr))
 			memcpy(icmp_packet_rr->rr,
 			       neigh_node->if_incoming->net_dev->dev_addr,
 			       ETH_ALEN);

 		break;
 	default:
 		batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 			   "Error - can't send packet from char device: got unknown message type\n");
 		len = -EINVAL;
 		goto free_skb;
 	}

 	icmp_header->uid = socket_client->index;

 	if (icmp_header->version != BATADV_COMPAT_VERSION) {
 		icmp_header->msg_type = BATADV_PARAMETER_PROBLEM;
 		icmp_header->version = BATADV_COMPAT_VERSION;
 		batadv_socket_add_packet(socket_client, icmp_header,
 					 packet_len);
 		goto free_skb;
 	}

 	memcpy(icmp_header->orig, primary_if->net_dev->dev_addr, ETH_ALEN);

 	batadv_send_skb_packet(skb, neigh_node->if_incoming, neigh_node->addr);
 	goto out;

 dst_unreach:
 	icmp_header->msg_type = BATADV_DESTINATION_UNREACHABLE;
 	batadv_socket_add_packet(socket_client, icmp_header, packet_len);
 free_skb:
 	kfree_skb(skb);
 out:
 	if (primary_if)
 		batadv_hardif_free_ref(primary_if);
 	if (neigh_node)
 		batadv_neigh_node_free_ref(neigh_node);
 	if (orig_node)
 		batadv_orig_node_free_ref(orig_node);
 	return len;
 }

 static unsigned int batadv_socket_poll(struct file *file, poll_table *wait)
 {
 	struct batadv_socket_client *socket_client = file->private_data;

 	poll_wait(file, &socket_client->queue_wait, wait);

 	if (socket_client->queue_len > 0)
 		return POLLIN | POLLRDNORM;

 	return 0;
 }

 static const struct file_operations batadv_fops = {
 	.owner = THIS_MODULE,
 	.open = batadv_socket_open,
 	.release = batadv_socket_release,
 	.read = batadv_socket_read,
 	.write = batadv_socket_write,
 	.poll = batadv_socket_poll,
 	.llseek = no_llseek,
 };

 int batadv_socket_setup(struct batadv_priv *bat_priv)
 {
 	struct dentry *d;

 	if (!bat_priv->debug_dir)
 		goto err;

 	d = debugfs_create_file(BATADV_ICMP_SOCKET, S_IFREG | S_IWUSR | S_IRUSR,
 				bat_priv->debug_dir, bat_priv, &batadv_fops);
 	if (!d)
 		goto err;

 	return 0;

 err:
 	return -ENOMEM;
 }

 /**
  * batadv_socket_receive_packet - schedule an icmp packet to be sent to userspace
  *  on an icmp socket.
  * @socket_client: the socket this packet belongs to
  * @icmph: pointer to the header of the icmp packet
  * @icmp_len: total length of the icmp packet
  */
 static void batadv_socket_add_packet(struct batadv_socket_client *socket_client,
 				     struct batadv_icmp_header *icmph,
 				     size_t icmp_len)
 {
 	struct batadv_socket_packet *socket_packet;
 	size_t len;

 	socket_packet = kmalloc(sizeof(*socket_packet), GFP_ATOMIC);

 	if (!socket_packet)
 		return;

 	len = icmp_len;
 	/* check the maximum length before filling the buffer */
 	if (len > sizeof(socket_packet->icmp_packet))
 		len = sizeof(socket_packet->icmp_packet);

 	INIT_LIST_HEAD(&socket_packet->list);
 	memcpy(&socket_packet->icmp_packet, icmph, len);
 	socket_packet->icmp_len = len;

 	spin_lock_bh(&socket_client->lock);

 	/* while waiting for the lock the socket_client could have been
 	 * deleted
 	 */
 	if (!batadv_socket_client_hash[icmph->uid]) {
 		spin_unlock_bh(&socket_client->lock);
 		kfree(socket_packet);
 		return;
 	}

 	list_add_tail(&socket_packet->list, &socket_client->queue_list);
 	socket_client->queue_len++;

 	if (socket_client->queue_len > 100) {
 		socket_packet = list_first_entry(&socket_client->queue_list,
 						 struct batadv_socket_packet,
 						 list);

 		list_del(&socket_packet->list);
 		kfree(socket_packet);
 		socket_client->queue_len--;
 	}

 	spin_unlock_bh(&socket_client->lock);

 	wake_up(&socket_client->queue_wait);
 }

 /**
  * batadv_socket_receive_packet - schedule an icmp packet to be received
  *  locally and sent to userspace.
  * @icmph: pointer to the header of the icmp packet
  * @icmp_len: total length of the icmp packet
  */
 void batadv_socket_receive_packet(struct batadv_icmp_header *icmph,
 				  size_t icmp_len)
 {
 	struct batadv_socket_client *hash;

 	hash = batadv_socket_client_hash[icmph->uid];
 	if (hash)
 		batadv_socket_add_packet(hash, icmph, icmp_len);
 }
	/* Copyright (C) 2007-2013 B.A.T.M.A.N. contributors:
	*
	* Marek Lindner
	*
	* This program is free software; you can redistribute it and/or
	* modify it under the terms of version 2 of the GNU General Public
	* License as published by the Free Software Foundation.
	*
	* This program is distributed in the hope that it will be useful, but
	* WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	* General Public License for more details.
	*
	* You should have received a copy of the GNU General Public License
	* along with this program; if not, see <http://www.gnu.org/licenses/>.
	*/

	#include "main.h"
	#include <linux/debugfs.h>
	#include <linux/slab.h>
	#include "icmp_socket.h"
	#include "send.h"
	#include "hash.h"
	#include "originator.h"
	#include "hard-interface.h"

	static struct batadv_socket_client *batadv_socket_client_hash[256];

	static void batadv_socket_add_packet(struct batadv_socket_client *socket_client,
	struct batadv_icmp_header *icmph,
	size_t icmp_len);

	void batadv_socket_init(void)
	{
	memset(batadv_socket_client_hash, 0, sizeof(batadv_socket_client_hash));
	}

	static int batadv_socket_open(struct inode inode, struct file file)
	{
	unsigned int i;
	struct batadv_socket_client *socket_client;

	if (!try_module_get(THIS_MODULE))
	return -EBUSY;

	nonseekable_open(inode, file);

	socket_client = kmalloc(sizeof(*socket_client), GFP_KERNEL);
	if (!socket_client) {
	module_put(THIS_MODULE);
	return -ENOMEM;
	}

	for (i = 0; i < ARRAY_SIZE(batadv_socket_client_hash); i++) {
	if (!batadv_socket_client_hash[i]) {
	batadv_socket_client_hash[i] = socket_client;
	break;
	}
	}

	if (i == ARRAY_SIZE(batadv_socket_client_hash)) {
	pr_err("Error - can't add another packet client: maximum number of clients reached\n");
	kfree(socket_client);
	module_put(THIS_MODULE);
	return -EXFULL;
	}

	INIT_LIST_HEAD(&socket_client->queue_list);
	socket_client->queue_len = 0;
	socket_client->index = i;
	socket_client->bat_priv = inode->i_private;
	spin_lock_init(&socket_client->lock);
	init_waitqueue_head(&socket_client->queue_wait);

	file->private_data = socket_client;

	return 0;
	}

	static int batadv_socket_release(struct inode inode, struct file file)
	{
	struct batadv_socket_client *socket_client = file->private_data;
	struct batadv_socket_packet *socket_packet;
	struct list_head list_pos, list_pos_tmp;

	spin_lock_bh(&socket_client->lock);

	/* for all packets in the queue ... */
	list_for_each_safe(list_pos, list_pos_tmp, &socket_client->queue_list) {
	socket_packet = list_entry(list_pos,
	struct batadv_socket_packet, list);

	list_del(list_pos);
	kfree(socket_packet);
	}

	batadv_socket_client_hash[socket_client->index] = NULL;
	spin_unlock_bh(&socket_client->lock);

	kfree(socket_client);
	module_put(THIS_MODULE);

	return 0;
	}

	static ssize_t batadv_socket_read(struct file file, char __user buf,
	size_t count, loff_t *ppos)
	{
	struct batadv_socket_client *socket_client = file->private_data;
	struct batadv_socket_packet *socket_packet;
	size_t packet_len;
	int error;

	if ((file->f_flags & O_NONBLOCK) && (socket_client->queue_len == 0))
	return -EAGAIN;

	if ((!buf) \|\| (count < sizeof(struct batadv_icmp_packet)))
	return -EINVAL;

	if (!access_ok(VERIFY_WRITE, buf, count))
	return -EFAULT;

	error = wait_event_interruptible(socket_client->queue_wait,
	socket_client->queue_len);

	if (error)
	return error;

	spin_lock_bh(&socket_client->lock);

	socket_packet = list_first_entry(&socket_client->queue_list,
	struct batadv_socket_packet, list);
	list_del(&socket_packet->list);
	socket_client->queue_len--;

	spin_unlock_bh(&socket_client->lock);

	packet_len = min(count, socket_packet->icmp_len);
	error = copy_to_user(buf, &socket_packet->icmp_packet, packet_len);

	kfree(socket_packet);

	if (error)
	return -EFAULT;

	return packet_len;
	}

	static ssize_t batadv_socket_write(struct file file, const char __user buff,
	size_t len, loff_t *off)
	{
	struct batadv_socket_client *socket_client = file->private_data;
	struct batadv_priv *bat_priv = socket_client->bat_priv;
	struct batadv_hard_iface *primary_if = NULL;
	struct sk_buff *skb;
	struct batadv_icmp_packet_rr *icmp_packet_rr;
	struct batadv_icmp_header *icmp_header;
	struct batadv_orig_node *orig_node = NULL;
	struct batadv_neigh_node *neigh_node = NULL;
	size_t packet_len = sizeof(struct batadv_icmp_packet);

	if (len < sizeof(struct batadv_icmp_header)) {
	batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
	"Error - can't send packet from char device: invalid packet size\n");
	return -EINVAL;
	}

	primary_if = batadv_primary_if_get_selected(bat_priv);

	if (!primary_if) {
	len = -EFAULT;
	goto out;
	}

	if (len >= BATADV_ICMP_MAX_PACKET_SIZE)
	packet_len = BATADV_ICMP_MAX_PACKET_SIZE;
	else
	packet_len = len;

	skb = netdev_alloc_skb_ip_align(NULL, packet_len + ETH_HLEN);
	if (!skb) {
	len = -ENOMEM;
	goto out;
	}

	skb->priority = TC_PRIO_CONTROL;
	skb_reserve(skb, ETH_HLEN);
	icmp_header = (struct batadv_icmp_header *)skb_put(skb, packet_len);

	if (copy_from_user(icmp_header, buff, packet_len)) {
	len = -EFAULT;
	goto free_skb;
	}

	if (icmp_header->packet_type != BATADV_ICMP) {
	batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
	"Error - can't send packet from char device: got bogus packet type (expected: BAT_ICMP)\n");
	len = -EINVAL;
	goto free_skb;
	}

	switch (icmp_header->msg_type) {
	case BATADV_ECHO_REQUEST:
	if (len < sizeof(struct batadv_icmp_packet)) {
	batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
	"Error - can't send packet from char device: invalid packet size\n");
	len = -EINVAL;
	goto free_skb;
	}

	if (atomic_read(&bat_priv->mesh_state) != BATADV_MESH_ACTIVE)
	goto dst_unreach;

	orig_node = batadv_orig_hash_find(bat_priv, icmp_header->dst);
	if (!orig_node)
	goto dst_unreach;

	neigh_node = batadv_orig_node_get_router(orig_node);
	if (!neigh_node)
	goto dst_unreach;

	if (!neigh_node->if_incoming)
	goto dst_unreach;

	if (neigh_node->if_incoming->if_status != BATADV_IF_ACTIVE)
	goto dst_unreach;

	icmp_packet_rr = (struct batadv_icmp_packet_rr *)icmp_header;
	if (packet_len == sizeof(*icmp_packet_rr))
	memcpy(icmp_packet_rr->rr,
	neigh_node->if_incoming->net_dev->dev_addr,
	ETH_ALEN);

	break;
	default:
	batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
	"Error - can't send packet from char device: got unknown message type\n");
	len = -EINVAL;
	goto free_skb;
	}

	icmp_header->uid = socket_client->index;

	if (icmp_header->version != BATADV_COMPAT_VERSION) {
	icmp_header->msg_type = BATADV_PARAMETER_PROBLEM;
	icmp_header->version = BATADV_COMPAT_VERSION;
	batadv_socket_add_packet(socket_client, icmp_header,
	packet_len);
	goto free_skb;
	}

	memcpy(icmp_header->orig, primary_if->net_dev->dev_addr, ETH_ALEN);

	batadv_send_skb_packet(skb, neigh_node->if_incoming, neigh_node->addr);
	goto out;

	dst_unreach:
	icmp_header->msg_type = BATADV_DESTINATION_UNREACHABLE;
	batadv_socket_add_packet(socket_client, icmp_header, packet_len);
	free_skb:
	kfree_skb(skb);
	out:
	if (primary_if)
	batadv_hardif_free_ref(primary_if);
	if (neigh_node)
	batadv_neigh_node_free_ref(neigh_node);
	if (orig_node)
	batadv_orig_node_free_ref(orig_node);
	return len;
	}

	static unsigned int batadv_socket_poll(struct file file, poll_table wait)
	{
	struct batadv_socket_client *socket_client = file->private_data;

	poll_wait(file, &socket_client->queue_wait, wait);

	if (socket_client->queue_len > 0)
	return POLLIN \| POLLRDNORM;

	return 0;
	}

	static const struct file_operations batadv_fops = {
	.owner = THIS_MODULE,
	.open = batadv_socket_open,
	.release = batadv_socket_release,
	.read = batadv_socket_read,
	.write = batadv_socket_write,
	.poll = batadv_socket_poll,
	.llseek = no_llseek,
	};

	int batadv_socket_setup(struct batadv_priv *bat_priv)
	{
	struct dentry *d;

	if (!bat_priv->debug_dir)
	goto err;

	d = debugfs_create_file(BATADV_ICMP_SOCKET, S_IFREG \| S_IWUSR \| S_IRUSR,
	bat_priv->debug_dir, bat_priv, &batadv_fops);
	if (!d)
	goto err;

	return 0;

	err:
	return -ENOMEM;
	}

	/**
	* batadv_socket_receive_packet - schedule an icmp packet to be sent to userspace
	* on an icmp socket.
	* @socket_client: the socket this packet belongs to
	* @icmph: pointer to the header of the icmp packet
	* @icmp_len: total length of the icmp packet
	*/
	static void batadv_socket_add_packet(struct batadv_socket_client *socket_client,
	struct batadv_icmp_header *icmph,
	size_t icmp_len)
	{
	struct batadv_socket_packet *socket_packet;
	size_t len;

	socket_packet = kmalloc(sizeof(*socket_packet), GFP_ATOMIC);

	if (!socket_packet)
	return;

	len = icmp_len;
	/* check the maximum length before filling the buffer */
	if (len > sizeof(socket_packet->icmp_packet))
	len = sizeof(socket_packet->icmp_packet);

	INIT_LIST_HEAD(&socket_packet->list);
	memcpy(&socket_packet->icmp_packet, icmph, len);
	socket_packet->icmp_len = len;

	spin_lock_bh(&socket_client->lock);

	/* while waiting for the lock the socket_client could have been
	* deleted
	*/
	if (!batadv_socket_client_hash[icmph->uid]) {
	spin_unlock_bh(&socket_client->lock);
	kfree(socket_packet);
	return;
	}

	list_add_tail(&socket_packet->list, &socket_client->queue_list);
	socket_client->queue_len++;

	if (socket_client->queue_len > 100) {
	socket_packet = list_first_entry(&socket_client->queue_list,
	struct batadv_socket_packet,
	list);

	list_del(&socket_packet->list);
	kfree(socket_packet);
	socket_client->queue_len--;
	}

	spin_unlock_bh(&socket_client->lock);

	wake_up(&socket_client->queue_wait);
	}

	/**
	* batadv_socket_receive_packet - schedule an icmp packet to be received
	* locally and sent to userspace.
	* @icmph: pointer to the header of the icmp packet
	* @icmp_len: total length of the icmp packet
	*/
	void batadv_socket_receive_packet(struct batadv_icmp_header *icmph,
	size_t icmp_len)
	{
	struct batadv_socket_client *hash;

	hash = batadv_socket_client_hash[icmph->uid];
	if (hash)
	batadv_socket_add_packet(hash, icmph, icmp_len);
	}