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         socket_client = kmalloc(sizeof(struct socket_client), GFP_KERNEL);
  49
  50         if (!socket_client)
  51                 return -ENOMEM;
  52
  53         for (i = 0; i < ARRAY_SIZE(socket_client_hash); i++) {
  54                 if (!socket_client_hash[i]) {
  55                         socket_client_hash[i] = socket_client;
  56                         break;
  57                 }
  58         }
  59
  60         if (i == ARRAY_SIZE(socket_client_hash)) {
  61                 pr_err("Error - can't add another packet client: "
  62                        "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         unsigned long flags;
  86
  87         spin_lock_irqsave(&socket_client->lock, flags);
  88
  89         /* for all packets in the queue ... */
  90         list_for_each_safe(list_pos, list_pos_tmp, &socket_client->queue_list) {
  91                 socket_packet = list_entry(list_pos,
  92                                            struct socket_packet, list);
  93
  94                 list_del(list_pos);
  95                 kfree(socket_packet);
  96         }
  97
  98         socket_client_hash[socket_client->index] = NULL;
  99         spin_unlock_irqrestore(&socket_client->lock, flags);
 100
 101         kfree(socket_client);
 102         dec_module_count();
 103
 104         return 0;
 105 }
 106
 107 static ssize_t bat_socket_read(struct file *file, char __user *buf,
 108                                size_t count, loff_t *ppos)
 109 {
 110         struct socket_client *socket_client = file->private_data;
 111         struct socket_packet *socket_packet;
 112         size_t packet_len;
 113         int error;
 114         unsigned long flags;
 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_irqsave(&socket_client->lock, flags);
 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_irqrestore(&socket_client->lock, flags);
 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 icmp_packet_rr icmp_packet;
 158         struct orig_node *orig_node;
 159         struct batman_if *batman_if;
 160         size_t packet_len = sizeof(struct icmp_packet);
 161         uint8_t dstaddr[ETH_ALEN];
 162         unsigned long flags;
 163
 164         if (len < sizeof(struct icmp_packet)) {
 165                 bat_dbg(DBG_BATMAN, bat_priv,
 166                         "Error - can't send packet from char device: "
 167                         "invalid packet size\n");
 168                 return -EINVAL;
 169         }
 170
 171         if (!bat_priv->primary_if)
 172                 return -EFAULT;
 173
 174         if (len >= sizeof(struct icmp_packet_rr))
 175                 packet_len = sizeof(struct icmp_packet_rr);
 176
 177         if (!access_ok(VERIFY_READ, buff, packet_len))
 178                 return -EFAULT;
 179
 180         if (__copy_from_user(&icmp_packet, buff, packet_len))
 181                 return -EFAULT;
 182
 183         if (icmp_packet.packet_type != BAT_ICMP) {
 184                 bat_dbg(DBG_BATMAN, bat_priv,
 185                         "Error - can't send packet from char device: "
 186                         "got bogus packet type (expected: BAT_ICMP)\n");
 187                 return -EINVAL;
 188         }
 189
 190         if (icmp_packet.msg_type != ECHO_REQUEST) {
 191                 bat_dbg(DBG_BATMAN, bat_priv,
 192                         "Error - can't send packet from char device: "
 193                         "got bogus message type (expected: ECHO_REQUEST)\n");
 194                 return -EINVAL;
 195         }
 196
 197         icmp_packet.uid = socket_client->index;
 198
 199         if (icmp_packet.version != COMPAT_VERSION) {
 200                 icmp_packet.msg_type = PARAMETER_PROBLEM;
 201                 icmp_packet.ttl = COMPAT_VERSION;
 202                 bat_socket_add_packet(socket_client, &icmp_packet, packet_len);
 203                 goto out;
 204         }
 205
 206         if (atomic_read(&module_state) != MODULE_ACTIVE)
 207                 goto dst_unreach;
 208
 209         spin_lock_irqsave(&orig_hash_lock, flags);
 210         orig_node = ((struct orig_node *)hash_find(orig_hash, icmp_packet.dst));
 211
 212         if (!orig_node)
 213                 goto unlock;
 214
 215         if (!orig_node->router)
 216                 goto unlock;
 217
 218         batman_if = orig_node->router->if_incoming;
 219         memcpy(dstaddr, orig_node->router->addr, ETH_ALEN);
 220
 221         spin_unlock_irqrestore(&orig_hash_lock, flags);
 222
 223         if (!batman_if)
 224                 goto dst_unreach;
 225
 226         if (batman_if->if_status != IF_ACTIVE)
 227                 goto dst_unreach;
 228
 229         memcpy(icmp_packet.orig,
 230                bat_priv->primary_if->net_dev->dev_addr, ETH_ALEN);
 231
 232         if (packet_len == sizeof(struct icmp_packet_rr))
 233                 memcpy(icmp_packet.rr, batman_if->net_dev->dev_addr, ETH_ALEN);
 234
 235         send_raw_packet((unsigned char *)&icmp_packet,
 236                         packet_len, batman_if, dstaddr);
 237
 238         goto out;
 239
 240 unlock:
 241         spin_unlock_irqrestore(&orig_hash_lock, flags);
 242 dst_unreach:
 243         icmp_packet.msg_type = DESTINATION_UNREACHABLE;
 244         bat_socket_add_packet(socket_client, &icmp_packet, packet_len);
 245 out:
 246         return len;
 247 }
 248
 249 static unsigned int bat_socket_poll(struct file *file, poll_table *wait)
 250 {
 251         struct socket_client *socket_client = file->private_data;
 252
 253         poll_wait(file, &socket_client->queue_wait, wait);
 254
 255         if (socket_client->queue_len > 0)
 256                 return POLLIN | POLLRDNORM;
 257
 258         return 0;
 259 }
 260
 261 static const struct file_operations fops = {
 262         .owner = THIS_MODULE,
 263         .open = bat_socket_open,
 264         .release = bat_socket_release,
 265         .read = bat_socket_read,
 266         .write = bat_socket_write,
 267         .poll = bat_socket_poll,
 268 };
 269
 270 int bat_socket_setup(struct bat_priv *bat_priv)
 271 {
 272         struct dentry *d;
 273
 274         if (!bat_priv->debug_dir)
 275                 goto err;
 276
 277         d = debugfs_create_file(ICMP_SOCKET, S_IFREG | S_IWUSR | S_IRUSR,
 278                                 bat_priv->debug_dir, bat_priv, &fops);
 279         if (d)
 280                 goto err;
 281
 282         return 0;
 283
 284 err:
 285         return 1;
 286 }
 287
 288 static void bat_socket_add_packet(struct socket_client *socket_client,
 289                                   struct icmp_packet_rr *icmp_packet,
 290                                   size_t icmp_len)
 291 {
 292         struct socket_packet *socket_packet;
 293         unsigned long flags;
 294
 295         socket_packet = kmalloc(sizeof(struct socket_packet), GFP_ATOMIC);
 296
 297         if (!socket_packet)
 298                 return;
 299
 300         INIT_LIST_HEAD(&socket_packet->list);
 301         memcpy(&socket_packet->icmp_packet, icmp_packet, icmp_len);
 302         socket_packet->icmp_len = icmp_len;
 303
 304         spin_lock_irqsave(&socket_client->lock, flags);
 305
 306         /* while waiting for the lock the socket_client could have been
 307          * deleted */
 308         if (!socket_client_hash[icmp_packet->uid]) {
 309                 spin_unlock_irqrestore(&socket_client->lock, flags);
 310                 kfree(socket_packet);
 311                 return;
 312         }
 313
 314         list_add_tail(&socket_packet->list, &socket_client->queue_list);
 315         socket_client->queue_len++;
 316
 317         if (socket_client->queue_len > 100) {
 318                 socket_packet = list_first_entry(&socket_client->queue_list,
 319                                                  struct socket_packet, list);
 320
 321                 list_del(&socket_packet->list);
 322                 kfree(socket_packet);
 323                 socket_client->queue_len--;
 324         }
 325
 326         spin_unlock_irqrestore(&socket_client->lock, flags);
 327
 328         wake_up(&socket_client->queue_wait);
 329 }
 330
 331 void bat_socket_receive_packet(struct icmp_packet_rr *icmp_packet,
 332                                size_t icmp_len)
 333 {
 334         struct socket_client *hash = socket_client_hash[icmp_packet->uid];
 335
 336         if (hash)
 337                 bat_socket_add_packet(hash, icmp_packet, icmp_len);
 338 }