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