net/batman-adv/icmp_socket.c

   1 /*
   2  * Copyright (C) 2007-2012 B.A.T.M.A.N. contributors:
   3  *
   4  * Marek Lindner
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of version 2 of the GNU General Public
   8  * License as published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it will be useful, but
  11  * WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  13  * General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  18  * 02110-1301, USA
  19  *
  20  */
  21
  22 #include "main.h"
  23 #include <linux/debugfs.h>
  24 #include <linux/slab.h>
  25 #include "icmp_socket.h"
  26 #include "send.h"
  27 #include "hash.h"
  28 #include "originator.h"
  29 #include "hard-interface.h"
  30
  31 static struct socket_client *socket_client_hash[256];
  32
  33 static void bat_socket_add_packet(struct socket_client *socket_client,
  34                                   struct icmp_packet_rr *icmp_packet,
  35                                   size_t icmp_len);
  36
  37 void bat_socket_init(void)
  38 {
  39         memset(socket_client_hash, 0, sizeof(socket_client_hash));
  40 }
  41
  42 static int bat_socket_open(struct inode *inode, struct file *file)
  43 {
  44         unsigned int i;
  45         struct socket_client *socket_client;
  46
  47         nonseekable_open(inode, file);
  48
  49         socket_client = kmalloc(sizeof(*socket_client), GFP_KERNEL);
  50
  51         if (!socket_client)
  52                 return -ENOMEM;
  53
  54         for (i = 0; i < ARRAY_SIZE(socket_client_hash); i++) {
  55                 if (!socket_client_hash[i]) {
  56                         socket_client_hash[i] = socket_client;
  57                         break;
  58                 }
  59         }
  60
  61         if (i == ARRAY_SIZE(socket_client_hash)) {
  62                 pr_err("Error - can't add another packet client: maximum number of clients reached\n");
  63                 kfree(socket_client);
  64                 return -EXFULL;
  65         }
  66
  67         INIT_LIST_HEAD(&socket_client->queue_list);
  68         socket_client->queue_len = 0;
  69         socket_client->index = i;
  70         socket_client->bat_priv = inode->i_private;
  71         spin_lock_init(&socket_client->lock);
  72         init_waitqueue_head(&socket_client->queue_wait);
  73
  74         file->private_data = socket_client;
  75
  76         inc_module_count();
  77         return 0;
  78 }
  79
  80 static int bat_socket_release(struct inode *inode, struct file *file)
  81 {
  82         struct socket_client *socket_client = file->private_data;
  83         struct socket_packet *socket_packet;
  84         struct list_head *list_pos, *list_pos_tmp;
  85
  86         spin_lock_bh(&socket_client->lock);
  87
  88         /* for all packets in the queue ... */
  89         list_for_each_safe(list_pos, list_pos_tmp, &socket_client->queue_list) {
  90                 socket_packet = list_entry(list_pos,
  91                                            struct socket_packet, list);
  92
  93                 list_del(list_pos);
  94                 kfree(socket_packet);
  95         }
  96
  97         socket_client_hash[socket_client->index] = NULL;
  98         spin_unlock_bh(&socket_client->lock);
  99
 100         kfree(socket_client);
 101         dec_module_count();
 102
 103         return 0;
 104 }
 105
 106 static ssize_t bat_socket_read(struct file *file, char __user *buf,
 107                                size_t count, loff_t *ppos)
 108 {
 109         struct socket_client *socket_client = file->private_data;
 110         struct socket_packet *socket_packet;
 111         size_t packet_len;
 112         int error;
 113
 114         if ((file->f_flags & O_NONBLOCK) && (socket_client->queue_len == 0))
 115                 return -EAGAIN;
 116
 117         if ((!buf) || (count < sizeof(struct icmp_packet)))
 118                 return -EINVAL;
 119
 120         if (!access_ok(VERIFY_WRITE, buf, count))
 121                 return -EFAULT;
 122
 123         error = wait_event_interruptible(socket_client->queue_wait,
 124                                          socket_client->queue_len);
 125
 126         if (error)
 127                 return error;
 128
 129         spin_lock_bh(&socket_client->lock);
 130
 131         socket_packet = list_first_entry(&socket_client->queue_list,
 132                                          struct socket_packet, list);
 133         list_del(&socket_packet->list);
 134         socket_client->queue_len--;
 135
 136         spin_unlock_bh(&socket_client->lock);
 137
 138         packet_len = min(count, socket_packet->icmp_len);
 139         error = copy_to_user(buf, &socket_packet->icmp_packet, packet_len);
 140
 141         kfree(socket_packet);
 142
 143         if (error)
 144                 return -EFAULT;
 145
 146         return packet_len;
 147 }
 148
 149 static ssize_t bat_socket_write(struct file *file, const char __user *buff,
 150                                 size_t len, loff_t *off)
 151 {
 152         struct socket_client *socket_client = file->private_data;
 153         struct bat_priv *bat_priv = socket_client->bat_priv;
 154         struct hard_iface *primary_if = NULL;
 155         struct sk_buff *skb;
 156         struct icmp_packet_rr *icmp_packet;
 157
 158         struct orig_node *orig_node = NULL;
 159         struct neigh_node *neigh_node = NULL;
 160         size_t packet_len = sizeof(struct icmp_packet);
 161
 162         if (len < sizeof(struct icmp_packet)) {
 163                 bat_dbg(DBG_BATMAN, bat_priv,
 164                         "Error - can't send packet from char device: invalid packet size\n");
 165                 return -EINVAL;
 166         }
 167
 168         primary_if = primary_if_get_selected(bat_priv);
 169
 170         if (!primary_if) {
 171                 len = -EFAULT;
 172                 goto out;
 173         }
 174
 175         if (len >= sizeof(struct icmp_packet_rr))
 176                 packet_len = sizeof(struct icmp_packet_rr);
 177
 178         skb = dev_alloc_skb(packet_len + sizeof(struct ethhdr));
 179         if (!skb) {
 180                 len = -ENOMEM;
 181                 goto out;
 182         }
 183
 184         skb_reserve(skb, sizeof(struct ethhdr));
 185         icmp_packet = (struct icmp_packet_rr *)skb_put(skb, packet_len);
 186
 187         if (copy_from_user(icmp_packet, buff, packet_len)) {
 188                 len = -EFAULT;
 189                 goto free_skb;
 190         }
 191
 192         if (icmp_packet->header.packet_type != BAT_ICMP) {
 193                 bat_dbg(DBG_BATMAN, bat_priv,
 194                         "Error - can't send packet from char device: got bogus packet type (expected: BAT_ICMP)\n");
 195                 len = -EINVAL;
 196                 goto free_skb;
 197         }
 198
 199         if (icmp_packet->msg_type != ECHO_REQUEST) {
 200                 bat_dbg(DBG_BATMAN, bat_priv,
 201                         "Error - can't send packet from char device: got bogus message type (expected: ECHO_REQUEST)\n");
 202                 len = -EINVAL;
 203                 goto free_skb;
 204         }
 205
 206         icmp_packet->uid = socket_client->index;
 207
 208         if (icmp_packet->header.version != COMPAT_VERSION) {
 209                 icmp_packet->msg_type = PARAMETER_PROBLEM;
 210                 icmp_packet->header.version = COMPAT_VERSION;
 211                 bat_socket_add_packet(socket_client, icmp_packet, packet_len);
 212                 goto free_skb;
 213         }
 214
 215         if (atomic_read(&bat_priv->mesh_state) != MESH_ACTIVE)
 216                 goto dst_unreach;
 217
 218         orig_node = orig_hash_find(bat_priv, icmp_packet->dst);
 219         if (!orig_node)
 220                 goto dst_unreach;
 221
 222         neigh_node = orig_node_get_router(orig_node);
 223         if (!neigh_node)
 224                 goto dst_unreach;
 225
 226         if (!neigh_node->if_incoming)
 227                 goto dst_unreach;
 228
 229         if (neigh_node->if_incoming->if_status != IF_ACTIVE)
 230                 goto dst_unreach;
 231
 232         memcpy(icmp_packet->orig,
 233                primary_if->net_dev->dev_addr, ETH_ALEN);
 234
 235         if (packet_len == sizeof(struct icmp_packet_rr))
 236                 memcpy(icmp_packet->rr,
 237                        neigh_node->if_incoming->net_dev->dev_addr, ETH_ALEN);
 238
 239         send_skb_packet(skb, neigh_node->if_incoming, neigh_node->addr);
 240         goto out;
 241
 242 dst_unreach:
 243         icmp_packet->msg_type = DESTINATION_UNREACHABLE;
 244         bat_socket_add_packet(socket_client, icmp_packet, packet_len);
 245 free_skb:
 246         kfree_skb(skb);
 247 out:
 248         if (primary_if)
 249                 hardif_free_ref(primary_if);
 250         if (neigh_node)
 251                 neigh_node_free_ref(neigh_node);
 252         if (orig_node)
 253                 orig_node_free_ref(orig_node);
 254         return len;
 255 }
 256
 257 static unsigned int bat_socket_poll(struct file *file, poll_table *wait)
 258 {
 259         struct socket_client *socket_client = file->private_data;
 260
 261         poll_wait(file, &socket_client->queue_wait, wait);
 262
 263         if (socket_client->queue_len > 0)
 264                 return POLLIN | POLLRDNORM;
 265
 266         return 0;
 267 }
 268
 269 static const struct file_operations fops = {
 270         .owner = THIS_MODULE,
 271         .open = bat_socket_open,
 272         .release = bat_socket_release,
 273         .read = bat_socket_read,
 274         .write = bat_socket_write,
 275         .poll = bat_socket_poll,
 276         .llseek = no_llseek,
 277 };
 278
 279 int bat_socket_setup(struct bat_priv *bat_priv)
 280 {
 281         struct dentry *d;
 282
 283         if (!bat_priv->debug_dir)
 284                 goto err;
 285
 286         d = debugfs_create_file(ICMP_SOCKET, S_IFREG | S_IWUSR | S_IRUSR,
 287                                 bat_priv->debug_dir, bat_priv, &fops);
 288         if (d)
 289                 goto err;
 290
 291         return 0;
 292
 293 err:
 294         return 1;
 295 }
 296
 297 static void bat_socket_add_packet(struct socket_client *socket_client,
 298                                   struct icmp_packet_rr *icmp_packet,
 299                                   size_t icmp_len)
 300 {
 301         struct socket_packet *socket_packet;
 302
 303         socket_packet = kmalloc(sizeof(*socket_packet), GFP_ATOMIC);
 304
 305         if (!socket_packet)
 306                 return;
 307
 308         INIT_LIST_HEAD(&socket_packet->list);
 309         memcpy(&socket_packet->icmp_packet, icmp_packet, icmp_len);
 310         socket_packet->icmp_len = icmp_len;
 311
 312         spin_lock_bh(&socket_client->lock);
 313
 314         /* while waiting for the lock the socket_client could have been
 315          * deleted */
 316         if (!socket_client_hash[icmp_packet->uid]) {
 317                 spin_unlock_bh(&socket_client->lock);
 318                 kfree(socket_packet);
 319                 return;
 320         }
 321
 322         list_add_tail(&socket_packet->list, &socket_client->queue_list);
 323         socket_client->queue_len++;
 324
 325         if (socket_client->queue_len > 100) {
 326                 socket_packet = list_first_entry(&socket_client->queue_list,
 327                                                  struct socket_packet, list);
 328
 329                 list_del(&socket_packet->list);
 330                 kfree(socket_packet);
 331                 socket_client->queue_len--;
 332         }
 333
 334         spin_unlock_bh(&socket_client->lock);
 335
 336         wake_up(&socket_client->queue_wait);
 337 }
 338
 339 void bat_socket_receive_packet(struct icmp_packet_rr *icmp_packet,
 340                                size_t icmp_len)
 341 {
 342         struct socket_client *hash = socket_client_hash[icmp_packet->uid];
 343
 344         if (hash)
 345                 bat_socket_add_packet(hash, icmp_packet, icmp_len);
 346 }