linux/net/batman-adv/icmp_socket.c
Simon Wunderlich da6b8c20a5 batman-adv: generalize batman-adv icmp packet handling
Instead of handling icmp packets only up to length of icmp_packet_rr,
the code should handle any icmp length size. Therefore the length
truncating is moved to when the packet is actually sent to userspace
(this does not support lengths longer than icmp_packet_rr yet). Longer
packets are forwarded without truncating.

This patch also cleans up some parts where the icmp header struct could
be used instead of other icmp_packet(_rr) structs to make the code more
readable.

Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: Antonio Quartulli <antonio@meshcoding.com>
2013-10-23 17:03:47 +02:00

386 lines
10 KiB
C

/* 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, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301, USA
*/
#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->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->header.version != BATADV_COMPAT_VERSION) {
icmp_header->msg_type = BATADV_PARAMETER_PROBLEM;
icmp_header->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);
}