net/batman-adv/icmp_socket.c

   1 /* Copyright (C) 2007-2012 B.A.T.M.A.N. contributors:
   2  *
   3  * Marek Lindner
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of version 2 of the GNU General Public
   7  * License as published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it will be useful, but
  10  * WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  12  * General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  17  * 02110-1301, USA
  18  */
  19
  20 #include "main.h"
  21 #include <linux/debugfs.h>
  22 #include <linux/slab.h>
  23 #include "icmp_socket.h"
  24 #include "send.h"
  25 #include "hash.h"
  26 #include "originator.h"
  27 #include "hard-interface.h"
  28
  29 static struct batadv_socket_client *batadv_socket_client_hash[256];
  30
  31 static void batadv_socket_add_packet(struct batadv_socket_client *socket_client,
  32                                      struct batadv_icmp_packet_rr *icmp_packet,
  33                                      size_t icmp_len);
  34
  35 void batadv_socket_init(void)
  36 {
  37         memset(batadv_socket_client_hash, 0, sizeof(batadv_socket_client_hash));
  38 }
  39
  40 static int batadv_socket_open(struct inode *inode, struct file *file)
  41 {
  42         unsigned int i;
  43         struct batadv_socket_client *socket_client;
  44
  45         nonseekable_open(inode, file);
  46
  47         socket_client = kmalloc(sizeof(*socket_client), GFP_KERNEL);
  48
  49         if (!socket_client)
  50                 return -ENOMEM;
  51
  52         for (i = 0; i < ARRAY_SIZE(batadv_socket_client_hash); i++) {
  53                 if (!batadv_socket_client_hash[i]) {
  54                         batadv_socket_client_hash[i] = socket_client;
  55                         break;
  56                 }
  57         }
  58
  59         if (i == ARRAY_SIZE(batadv_socket_client_hash)) {
  60                 pr_err("Error - can't add another packet client: maximum number of clients reached\n");
  61                 kfree(socket_client);
  62                 return -EXFULL;
  63         }
  64
  65         INIT_LIST_HEAD(&socket_client->queue_list);
  66         socket_client->queue_len = 0;
  67         socket_client->index = i;
  68         socket_client->bat_priv = inode->i_private;
  69         spin_lock_init(&socket_client->lock);
  70         init_waitqueue_head(&socket_client->queue_wait);
  71
  72         file->private_data = socket_client;
  73
  74         batadv_inc_module_count();
  75         return 0;
  76 }
  77
  78 static int batadv_socket_release(struct inode *inode, struct file *file)
  79 {
  80         struct batadv_socket_client *socket_client = file->private_data;
  81         struct batadv_socket_packet *socket_packet;
  82         struct list_head *list_pos, *list_pos_tmp;
  83
  84         spin_lock_bh(&socket_client->lock);
  85
  86         /* for all packets in the queue ... */
  87         list_for_each_safe(list_pos, list_pos_tmp, &socket_client->queue_list) {
  88                 socket_packet = list_entry(list_pos,
  89                                            struct batadv_socket_packet, list);
  90
  91                 list_del(list_pos);
  92                 kfree(socket_packet);
  93         }
  94
  95         batadv_socket_client_hash[socket_client->index] = NULL;
  96         spin_unlock_bh(&socket_client->lock);
  97
  98         kfree(socket_client);
  99         batadv_dec_module_count();
 100
 101         return 0;
 102 }
 103
 104 static ssize_t batadv_socket_read(struct file *file, char __user *buf,
 105                                   size_t count, loff_t *ppos)
 106 {
 107         struct batadv_socket_client *socket_client = file->private_data;
 108         struct batadv_socket_packet *socket_packet;
 109         size_t packet_len;
 110         int error;
 111
 112         if ((file->f_flags & O_NONBLOCK) && (socket_client->queue_len == 0))
 113                 return -EAGAIN;
 114
 115         if ((!buf) || (count < sizeof(struct batadv_icmp_packet)))
 116                 return -EINVAL;
 117
 118         if (!access_ok(VERIFY_WRITE, buf, count))
 119                 return -EFAULT;
 120
 121         error = wait_event_interruptible(socket_client->queue_wait,
 122                                          socket_client->queue_len);
 123
 124         if (error)
 125                 return error;
 126
 127         spin_lock_bh(&socket_client->lock);
 128
 129         socket_packet = list_first_entry(&socket_client->queue_list,
 130                                          struct batadv_socket_packet, list);
 131         list_del(&socket_packet->list);
 132         socket_client->queue_len--;
 133
 134         spin_unlock_bh(&socket_client->lock);
 135
 136         packet_len = min(count, socket_packet->icmp_len);
 137         error = copy_to_user(buf, &socket_packet->icmp_packet, packet_len);
 138
 139         kfree(socket_packet);
 140
 141         if (error)
 142                 return -EFAULT;
 143
 144         return packet_len;
 145 }
 146
 147 static ssize_t batadv_socket_write(struct file *file, const char __user *buff,
 148                                    size_t len, loff_t *off)
 149 {
 150         struct batadv_socket_client *socket_client = file->private_data;
 151         struct batadv_priv *bat_priv = socket_client->bat_priv;
 152         struct batadv_hard_iface *primary_if = NULL;
 153         struct sk_buff *skb;
 154         struct batadv_icmp_packet_rr *icmp_packet;
 155
 156         struct batadv_orig_node *orig_node = NULL;
 157         struct batadv_neigh_node *neigh_node = NULL;
 158         size_t packet_len = sizeof(struct batadv_icmp_packet);
 159
 160         if (len < sizeof(struct batadv_icmp_packet)) {
 161                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 162                            "Error - can't send packet from char device: invalid packet size\n");
 163                 return -EINVAL;
 164         }
 165
 166         primary_if = batadv_primary_if_get_selected(bat_priv);
 167
 168         if (!primary_if) {
 169                 len = -EFAULT;
 170                 goto out;
 171         }
 172
 173         if (len >= sizeof(struct batadv_icmp_packet_rr))
 174                 packet_len = sizeof(struct batadv_icmp_packet_rr);
 175
 176         skb = dev_alloc_skb(packet_len + ETH_HLEN);
 177         if (!skb) {
 178                 len = -ENOMEM;
 179                 goto out;
 180         }
 181
 182         skb_reserve(skb, ETH_HLEN);
 183         icmp_packet = (struct batadv_icmp_packet_rr *)skb_put(skb, packet_len);
 184
 185         if (copy_from_user(icmp_packet, buff, packet_len)) {
 186                 len = -EFAULT;
 187                 goto free_skb;
 188         }
 189
 190         if (icmp_packet->header.packet_type != BATADV_ICMP) {
 191                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 192                            "Error - can't send packet from char device: got bogus packet type (expected: BAT_ICMP)\n");
 193                 len = -EINVAL;
 194                 goto free_skb;
 195         }
 196
 197         if (icmp_packet->msg_type != BATADV_ECHO_REQUEST) {
 198                 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 199                            "Error - can't send packet from char device: got bogus message type (expected: ECHO_REQUEST)\n");
 200                 len = -EINVAL;
 201                 goto free_skb;
 202         }
 203
 204         icmp_packet->uid = socket_client->index;
 205
 206         if (icmp_packet->header.version != BATADV_COMPAT_VERSION) {
 207                 icmp_packet->msg_type = BATADV_PARAMETER_PROBLEM;
 208                 icmp_packet->header.version = BATADV_COMPAT_VERSION;
 209                 batadv_socket_add_packet(socket_client, icmp_packet,
 210                                          packet_len);
 211                 goto free_skb;
 212         }
 213
 214         if (atomic_read(&bat_priv->mesh_state) != BATADV_MESH_ACTIVE)
 215                 goto dst_unreach;
 216
 217         orig_node = batadv_orig_hash_find(bat_priv, icmp_packet->dst);
 218         if (!orig_node)
 219                 goto dst_unreach;
 220
 221         neigh_node = batadv_orig_node_get_router(orig_node);
 222         if (!neigh_node)
 223                 goto dst_unreach;
 224
 225         if (!neigh_node->if_incoming)
 226                 goto dst_unreach;
 227
 228         if (neigh_node->if_incoming->if_status != BATADV_IF_ACTIVE)
 229                 goto dst_unreach;
 230
 231         memcpy(icmp_packet->orig,
 232                primary_if->net_dev->dev_addr, ETH_ALEN);
 233
 234         if (packet_len == sizeof(struct batadv_icmp_packet_rr))
 235                 memcpy(icmp_packet->rr,
 236                        neigh_node->if_incoming->net_dev->dev_addr, ETH_ALEN);
 237
 238         batadv_send_skb_packet(skb, neigh_node->if_incoming, neigh_node->addr);
 239         goto out;
 240
 241 dst_unreach:
 242         icmp_packet->msg_type = BATADV_DESTINATION_UNREACHABLE;
 243         batadv_socket_add_packet(socket_client, icmp_packet, packet_len);
 244 free_skb:
 245         kfree_skb(skb);
 246 out:
 247         if (primary_if)
 248                 batadv_hardif_free_ref(primary_if);
 249         if (neigh_node)
 250                 batadv_neigh_node_free_ref(neigh_node);
 251         if (orig_node)
 252                 batadv_orig_node_free_ref(orig_node);
 253         return len;
 254 }
 255
 256 static unsigned int batadv_socket_poll(struct file *file, poll_table *wait)
 257 {
 258         struct batadv_socket_client *socket_client = file->private_data;
 259
 260         poll_wait(file, &socket_client->queue_wait, wait);
 261
 262         if (socket_client->queue_len > 0)
 263                 return POLLIN | POLLRDNORM;
 264
 265         return 0;
 266 }
 267
 268 static const struct file_operations batadv_fops = {
 269         .owner = THIS_MODULE,
 270         .open = batadv_socket_open,
 271         .release = batadv_socket_release,
 272         .read = batadv_socket_read,
 273         .write = batadv_socket_write,
 274         .poll = batadv_socket_poll,
 275         .llseek = no_llseek,
 276 };
 277
 278 int batadv_socket_setup(struct batadv_priv *bat_priv)
 279 {
 280         struct dentry *d;
 281
 282         if (!bat_priv->debug_dir)
 283                 goto err;
 284
 285         d = debugfs_create_file(BATADV_ICMP_SOCKET, S_IFREG | S_IWUSR | S_IRUSR,
 286                                 bat_priv->debug_dir, bat_priv, &batadv_fops);
 287         if (!d)
 288                 goto err;
 289
 290         return 0;
 291
 292 err:
 293         return -ENOMEM;
 294 }
 295
 296 static void batadv_socket_add_packet(struct batadv_socket_client *socket_client,
 297                                      struct batadv_icmp_packet_rr *icmp_packet,
 298                                      size_t icmp_len)
 299 {
 300         struct batadv_socket_packet *socket_packet;
 301
 302         socket_packet = kmalloc(sizeof(*socket_packet), GFP_ATOMIC);
 303
 304         if (!socket_packet)
 305                 return;
 306
 307         INIT_LIST_HEAD(&socket_packet->list);
 308         memcpy(&socket_packet->icmp_packet, icmp_packet, icmp_len);
 309         socket_packet->icmp_len = icmp_len;
 310
 311         spin_lock_bh(&socket_client->lock);
 312
 313         /* while waiting for the lock the socket_client could have been
 314          * deleted
 315          */
 316         if (!batadv_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 batadv_socket_packet,
 328                                                  list);
 329
 330                 list_del(&socket_packet->list);
 331                 kfree(socket_packet);
 332                 socket_client->queue_len--;
 333         }
 334
 335         spin_unlock_bh(&socket_client->lock);
 336
 337         wake_up(&socket_client->queue_wait);
 338 }
 339
 340 void batadv_socket_receive_packet(struct batadv_icmp_packet_rr *icmp_packet,
 341                                   size_t icmp_len)
 342 {
 343         struct batadv_socket_client *hash;
 344
 345         hash = batadv_socket_client_hash[icmp_packet->uid];
 346         if (hash)
 347                 batadv_socket_add_packet(hash, icmp_packet, icmp_len);
 348 }