drivers/staging/batman-adv/icmp_socket.c

   1 /*
   2  * Copyright (C) 2007-2010 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 "types.h"
  28 #include "hash.h"
  29 #include "hard-interface.h"
  30
  31
  32 static struct socket_client *socket_client_hash[256];
  33
  34 static void bat_socket_add_packet(struct socket_client *socket_client,
  35                                   struct icmp_packet_rr *icmp_packet,
  36                                   size_t icmp_len);
  37
  38 void bat_socket_init(void)
  39 {
  40         memset(socket_client_hash, 0, sizeof(socket_client_hash));
  41 }
  42
  43 static int bat_socket_open(struct inode *inode, struct file *file)
  44 {
  45         unsigned int i;
  46         struct socket_client *socket_client;
  47
  48         nonseekable_open(inode, file);
  49
  50         socket_client = kmalloc(sizeof(struct socket_client), GFP_KERNEL);
  51
  52         if (!socket_client)
  53                 return -ENOMEM;
  54
  55         for (i = 0; i < ARRAY_SIZE(socket_client_hash); i++) {
  56                 if (!socket_client_hash[i]) {
  57                         socket_client_hash[i] = socket_client;
  58                         break;
  59                 }
  60         }
  61
  62         if (i == ARRAY_SIZE(socket_client_hash)) {
  63                 pr_err("Error - can't add another packet client: "
  64                        "maximum number of clients reached\n");
  65                 kfree(socket_client);
  66                 return -EXFULL;
  67         }
  68
  69         INIT_LIST_HEAD(&socket_client->queue_list);
  70         socket_client->queue_len = 0;
  71         socket_client->index = i;
  72         socket_client->bat_priv = inode->i_private;
  73         spin_lock_init(&socket_client->lock);
  74         init_waitqueue_head(&socket_client->queue_wait);
  75
  76         file->private_data = socket_client;
  77
  78         inc_module_count();
  79         return 0;
  80 }
  81
  82 static int bat_socket_release(struct inode *inode, struct file *file)
  83 {
  84         struct socket_client *socket_client = file->private_data;
  85         struct socket_packet *socket_packet;
  86         struct list_head *list_pos, *list_pos_tmp;
  87         unsigned long flags;
  88
  89         spin_lock_irqsave(&socket_client->lock, flags);
  90
  91         /* for all packets in the queue ... */
  92         list_for_each_safe(list_pos, list_pos_tmp, &socket_client->queue_list) {
  93                 socket_packet = list_entry(list_pos,
  94                                            struct socket_packet, list);
  95
  96                 list_del(list_pos);
  97                 kfree(socket_packet);
  98         }
  99
 100         socket_client_hash[socket_client->index] = NULL;
 101         spin_unlock_irqrestore(&socket_client->lock, flags);
 102
 103         kfree(socket_client);
 104         dec_module_count();
 105
 106         return 0;
 107 }
 108
 109 static ssize_t bat_socket_read(struct file *file, char __user *buf,
 110                                size_t count, loff_t *ppos)
 111 {
 112         struct socket_client *socket_client = file->private_data;
 113         struct socket_packet *socket_packet;
 114         size_t packet_len;
 115         int error;
 116         unsigned long flags;
 117
 118         if ((file->f_flags & O_NONBLOCK) && (socket_client->queue_len == 0))
 119                 return -EAGAIN;
 120
 121         if ((!buf) || (count < sizeof(struct icmp_packet)))
 122                 return -EINVAL;
 123
 124         if (!access_ok(VERIFY_WRITE, buf, count))
 125                 return -EFAULT;
 126
 127         error = wait_event_interruptible(socket_client->queue_wait,
 128                                          socket_client->queue_len);
 129
 130         if (error)
 131                 return error;
 132
 133         spin_lock_irqsave(&socket_client->lock, flags);
 134
 135         socket_packet = list_first_entry(&socket_client->queue_list,
 136                                          struct socket_packet, list);
 137         list_del(&socket_packet->list);
 138         socket_client->queue_len--;
 139
 140         spin_unlock_irqrestore(&socket_client->lock, flags);
 141
 142         error = __copy_to_user(buf, &socket_packet->icmp_packet,
 143                                socket_packet->icmp_len);
 144
 145         packet_len = socket_packet->icmp_len;
 146         kfree(socket_packet);
 147
 148         if (error)
 149                 return -EFAULT;
 150
 151         return packet_len;
 152 }
 153
 154 static ssize_t bat_socket_write(struct file *file, const char __user *buff,
 155                                 size_t len, loff_t *off)
 156 {
 157         struct socket_client *socket_client = file->private_data;
 158         struct bat_priv *bat_priv = socket_client->bat_priv;
 159         struct sk_buff *skb;
 160         struct icmp_packet_rr *icmp_packet;
 161
 162         struct orig_node *orig_node;
 163         struct batman_if *batman_if;
 164         size_t packet_len = sizeof(struct icmp_packet);
 165         uint8_t dstaddr[ETH_ALEN];
 166         unsigned long flags;
 167
 168         if (len < sizeof(struct icmp_packet)) {
 169                 bat_dbg(DBG_BATMAN, bat_priv,
 170                         "Error - can't send packet from char device: "
 171                         "invalid packet size\n");
 172                 return -EINVAL;
 173         }
 174
 175         if (!bat_priv->primary_if)
 176                 return -EFAULT;
 177
 178         if (len >= sizeof(struct icmp_packet_rr))
 179                 packet_len = sizeof(struct icmp_packet_rr);
 180
 181         skb = dev_alloc_skb(packet_len + sizeof(struct ethhdr));
 182         if (!skb)
 183                 return -ENOMEM;
 184
 185         skb_reserve(skb, sizeof(struct ethhdr));
 186         icmp_packet = (struct icmp_packet_rr *)skb_put(skb, packet_len);
 187
 188         if (!access_ok(VERIFY_READ, buff, packet_len)) {
 189                 len = -EFAULT;
 190                 goto free_skb;
 191         }
 192
 193         if (__copy_from_user(icmp_packet, buff, packet_len)) {
 194                 len = -EFAULT;
 195                 goto free_skb;
 196         }
 197
 198         if (icmp_packet->packet_type != BAT_ICMP) {
 199                 bat_dbg(DBG_BATMAN, bat_priv,
 200                         "Error - can't send packet from char device: "
 201                         "got bogus packet type (expected: BAT_ICMP)\n");
 202                 len = -EINVAL;
 203                 goto free_skb;
 204         }
 205
 206         if (icmp_packet->msg_type != ECHO_REQUEST) {
 207                 bat_dbg(DBG_BATMAN, bat_priv,
 208                         "Error - can't send packet from char device: "
 209                         "got bogus message type (expected: ECHO_REQUEST)\n");
 210                 len = -EINVAL;
 211                 goto free_skb;
 212         }
 213
 214         icmp_packet->uid = socket_client->index;
 215
 216         if (icmp_packet->version != COMPAT_VERSION) {
 217                 icmp_packet->msg_type = PARAMETER_PROBLEM;
 218                 icmp_packet->ttl = COMPAT_VERSION;
 219                 bat_socket_add_packet(socket_client, icmp_packet, packet_len);
 220                 goto free_skb;
 221         }
 222
 223         if (atomic_read(&bat_priv->mesh_state) != MESH_ACTIVE)
 224                 goto dst_unreach;
 225
 226         spin_lock_irqsave(&bat_priv->orig_hash_lock, flags);
 227         orig_node = ((struct orig_node *)hash_find(bat_priv->orig_hash,
 228                                                    icmp_packet->dst));
 229
 230         if (!orig_node)
 231                 goto unlock;
 232
 233         if (!orig_node->router)
 234                 goto unlock;
 235
 236         batman_if = orig_node->router->if_incoming;
 237         memcpy(dstaddr, orig_node->router->addr, ETH_ALEN);
 238
 239         spin_unlock_irqrestore(&bat_priv->orig_hash_lock, flags);
 240
 241         if (!batman_if)
 242                 goto dst_unreach;
 243
 244         if (batman_if->if_status != IF_ACTIVE)
 245                 goto dst_unreach;
 246
 247         memcpy(icmp_packet->orig,
 248                bat_priv->primary_if->net_dev->dev_addr, ETH_ALEN);
 249
 250         if (packet_len == sizeof(struct icmp_packet_rr))
 251                 memcpy(icmp_packet->rr, batman_if->net_dev->dev_addr, ETH_ALEN);
 252
 253
 254         send_skb_packet(skb, batman_if, dstaddr);
 255
 256         goto out;
 257
 258 unlock:
 259         spin_unlock_irqrestore(&bat_priv->orig_hash_lock, flags);
 260 dst_unreach:
 261         icmp_packet->msg_type = DESTINATION_UNREACHABLE;
 262         bat_socket_add_packet(socket_client, icmp_packet, packet_len);
 263 free_skb:
 264         kfree_skb(skb);
 265 out:
 266         return len;
 267 }
 268
 269 static unsigned int bat_socket_poll(struct file *file, poll_table *wait)
 270 {
 271         struct socket_client *socket_client = file->private_data;
 272
 273         poll_wait(file, &socket_client->queue_wait, wait);
 274
 275         if (socket_client->queue_len > 0)
 276                 return POLLIN | POLLRDNORM;
 277
 278         return 0;
 279 }
 280
 281 static const struct file_operations fops = {
 282         .owner = THIS_MODULE,
 283         .open = bat_socket_open,
 284         .release = bat_socket_release,
 285         .read = bat_socket_read,
 286         .write = bat_socket_write,
 287         .poll = bat_socket_poll,
 288         .llseek = no_llseek,
 289 };
 290
 291 int bat_socket_setup(struct bat_priv *bat_priv)
 292 {
 293         struct dentry *d;
 294
 295         if (!bat_priv->debug_dir)
 296                 goto err;
 297
 298         d = debugfs_create_file(ICMP_SOCKET, S_IFREG | S_IWUSR | S_IRUSR,
 299                                 bat_priv->debug_dir, bat_priv, &fops);
 300         if (d)
 301                 goto err;
 302
 303         return 0;
 304
 305 err:
 306         return 1;
 307 }
 308
 309 static void bat_socket_add_packet(struct socket_client *socket_client,
 310                                   struct icmp_packet_rr *icmp_packet,
 311                                   size_t icmp_len)
 312 {
 313         struct socket_packet *socket_packet;
 314         unsigned long flags;
 315
 316         socket_packet = kmalloc(sizeof(struct socket_packet), GFP_ATOMIC);
 317
 318         if (!socket_packet)
 319                 return;
 320
 321         INIT_LIST_HEAD(&socket_packet->list);
 322         memcpy(&socket_packet->icmp_packet, icmp_packet, icmp_len);
 323         socket_packet->icmp_len = icmp_len;
 324
 325         spin_lock_irqsave(&socket_client->lock, flags);
 326
 327         /* while waiting for the lock the socket_client could have been
 328          * deleted */
 329         if (!socket_client_hash[icmp_packet->uid]) {
 330                 spin_unlock_irqrestore(&socket_client->lock, flags);
 331                 kfree(socket_packet);
 332                 return;
 333         }
 334
 335         list_add_tail(&socket_packet->list, &socket_client->queue_list);
 336         socket_client->queue_len++;
 337
 338         if (socket_client->queue_len > 100) {
 339                 socket_packet = list_first_entry(&socket_client->queue_list,
 340                                                  struct socket_packet, list);
 341
 342                 list_del(&socket_packet->list);
 343                 kfree(socket_packet);
 344                 socket_client->queue_len--;
 345         }
 346
 347         spin_unlock_irqrestore(&socket_client->lock, flags);
 348
 349         wake_up(&socket_client->queue_wait);
 350 }
 351
 352 void bat_socket_receive_packet(struct icmp_packet_rr *icmp_packet,
 353                                size_t icmp_len)
 354 {
 355         struct socket_client *hash = socket_client_hash[icmp_packet->uid];
 356
 357         if (hash)
 358                 bat_socket_add_packet(hash, icmp_packet, icmp_len);
 359 }