SAFE public projects git trees. - safe/jmp/linux-2.6/blob - drivers/staging/batman-adv/device.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 <linux/device.h>
  23 #include <linux/slab.h>
  24 #include "main.h"
  25 #include "device.h"
  26 #include "send.h"
  27 #include "types.h"
  28 #include "hash.h"
  29 #include "hard-interface.h"
  30
  31 static struct class *batman_class;
  32
  33 static int Major;       /* Major number assigned to our device driver */
  34
  35 static const struct file_operations fops = {
  36         .open = bat_device_open,
  37         .release = bat_device_release,
  38         .read = bat_device_read,
  39         .write = bat_device_write,
  40         .poll = bat_device_poll,
  41 };
  42
  43 static struct device_client *device_client_hash[256];
  44
  45 void bat_device_init(void)
  46 {
  47         int i;
  48
  49         for (i = 0; i < 256; i++)
  50                 device_client_hash[i] = NULL;
  51 }
  52
  53 int bat_device_setup(void)
  54 {
  55         int tmp_major;
  56
  57         if (Major)
  58                 return 1;
  59
  60         /* register our device - kernel assigns a free major number */
  61         tmp_major = register_chrdev(0, DRIVER_DEVICE, &fops);
  62         if (tmp_major < 0) {
  63                 printk(KERN_ERR "batman-adv:Registering the character device failed with %d\n",
  64                           tmp_major);
  65                 return 0;
  66         }
  67
  68         batman_class = class_create(THIS_MODULE, "batman-adv");
  69
  70         if (IS_ERR(batman_class)) {
  71                 printk(KERN_ERR "batman-adv:Could not register class 'batman-adv' \n");
  72                 return 0;
  73         }
  74
  75         device_create(batman_class, NULL, MKDEV(tmp_major, 0), NULL,
  76                       "batman-adv");
  77
  78         Major = tmp_major;
  79         return 1;
  80 }
  81
  82 void bat_device_destroy(void)
  83 {
  84         if (!Major)
  85                 return;
  86
  87         device_destroy(batman_class, MKDEV(Major, 0));
  88         class_destroy(batman_class);
  89
  90         /* Unregister the device */
  91         unregister_chrdev(Major, DRIVER_DEVICE);
  92
  93         Major = 0;
  94 }
  95
  96 int bat_device_open(struct inode *inode, struct file *file)
  97 {
  98         unsigned int i;
  99         struct device_client *device_client;
 100
 101         device_client = kmalloc(sizeof(struct device_client), GFP_KERNEL);
 102
 103         if (!device_client)
 104                 return -ENOMEM;
 105
 106         for (i = 0; i < 256; i++) {
 107                 if (!device_client_hash[i]) {
 108                         device_client_hash[i] = device_client;
 109                         break;
 110                 }
 111         }
 112
 113         if (device_client_hash[i] != device_client) {
 114                 printk(KERN_ERR "batman-adv:Error - can't add another packet client: maximum number of clients reached \n");
 115                 kfree(device_client);
 116                 return -EXFULL;
 117         }
 118
 119         INIT_LIST_HEAD(&device_client->queue_list);
 120         device_client->queue_len = 0;
 121         device_client->index = i;
 122         spin_lock_init(&device_client->lock);
 123         init_waitqueue_head(&device_client->queue_wait);
 124
 125         file->private_data = device_client;
 126
 127         inc_module_count();
 128         return 0;
 129 }
 130
 131 int bat_device_release(struct inode *inode, struct file *file)
 132 {
 133         struct device_client *device_client =
 134                 (struct device_client *)file->private_data;
 135         struct device_packet *device_packet;
 136         struct list_head *list_pos, *list_pos_tmp;
 137         unsigned long flags;
 138
 139         spin_lock_irqsave(&device_client->lock, flags);
 140
 141         /* for all packets in the queue ... */
 142         list_for_each_safe(list_pos, list_pos_tmp, &device_client->queue_list) {
 143                 device_packet = list_entry(list_pos,
 144                                            struct device_packet, list);
 145
 146                 list_del(list_pos);
 147                 kfree(device_packet);
 148         }
 149
 150         device_client_hash[device_client->index] = NULL;
 151         spin_unlock_irqrestore(&device_client->lock, flags);
 152
 153         kfree(device_client);
 154         dec_module_count();
 155
 156         return 0;
 157 }
 158
 159 ssize_t bat_device_read(struct file *file, char __user *buf, size_t count,
 160                         loff_t *ppos)
 161 {
 162         struct device_client *device_client =
 163                 (struct device_client *)file->private_data;
 164         struct device_packet *device_packet;
 165         int error;
 166         unsigned long flags;
 167
 168         if ((file->f_flags & O_NONBLOCK) && (device_client->queue_len == 0))
 169                 return -EAGAIN;
 170
 171         if ((!buf) || (count < sizeof(struct icmp_packet)))
 172                 return -EINVAL;
 173
 174         if (!access_ok(VERIFY_WRITE, buf, count))
 175                 return -EFAULT;
 176
 177         error = wait_event_interruptible(device_client->queue_wait,
 178                                          device_client->queue_len);
 179
 180         if (error)
 181                 return error;
 182
 183         spin_lock_irqsave(&device_client->lock, flags);
 184
 185         device_packet = list_first_entry(&device_client->queue_list,
 186                                          struct device_packet, list);
 187         list_del(&device_packet->list);
 188         device_client->queue_len--;
 189
 190         spin_unlock_irqrestore(&device_client->lock, flags);
 191
 192         error = __copy_to_user(buf, &device_packet->icmp_packet,
 193                                sizeof(struct icmp_packet));
 194
 195         kfree(device_packet);
 196
 197         if (error)
 198                 return error;
 199
 200         return sizeof(struct icmp_packet);
 201 }
 202
 203 ssize_t bat_device_write(struct file *file, const char __user *buff,
 204                          size_t len, loff_t *off)
 205 {
 206         struct device_client *device_client =
 207                 (struct device_client *)file->private_data;
 208         struct icmp_packet icmp_packet;
 209         struct orig_node *orig_node;
 210         struct batman_if *batman_if;
 211         uint8_t dstaddr[ETH_ALEN];
 212         unsigned long flags;
 213
 214         if (len < sizeof(struct icmp_packet)) {
 215                 bat_dbg(DBG_BATMAN, "batman-adv:Error - can't send packet from char device: invalid packet size\n");
 216                 return -EINVAL;
 217         }
 218
 219         if (!access_ok(VERIFY_READ, buff, sizeof(struct icmp_packet)))
 220                 return -EFAULT;
 221
 222         if (__copy_from_user(&icmp_packet, buff, sizeof(icmp_packet)))
 223                 return -EFAULT;
 224
 225         if (icmp_packet.packet_type != BAT_ICMP) {
 226                 bat_dbg(DBG_BATMAN, "batman-adv:Error - can't send packet from char device: got bogus packet type (expected: BAT_ICMP)\n");
 227                 return -EINVAL;
 228         }
 229
 230         if (icmp_packet.msg_type != ECHO_REQUEST) {
 231                 bat_dbg(DBG_BATMAN, "batman-adv:Error - can't send packet from char device: got bogus message type (expected: ECHO_REQUEST)\n");
 232                 return -EINVAL;
 233         }
 234
 235         icmp_packet.uid = device_client->index;
 236
 237         if (icmp_packet.version != COMPAT_VERSION) {
 238                 icmp_packet.msg_type = PARAMETER_PROBLEM;
 239                 icmp_packet.ttl = COMPAT_VERSION;
 240                 bat_device_add_packet(device_client, &icmp_packet);
 241                 goto out;
 242         }
 243
 244         if (atomic_read(&module_state) != MODULE_ACTIVE)
 245                 goto dst_unreach;
 246
 247         spin_lock_irqsave(&orig_hash_lock, flags);
 248         orig_node = ((struct orig_node *)hash_find(orig_hash, icmp_packet.dst));
 249
 250         if (!orig_node)
 251                 goto unlock;
 252
 253         if (!orig_node->router)
 254                 goto unlock;
 255
 256         batman_if = orig_node->batman_if;
 257         memcpy(dstaddr, orig_node->router->addr, ETH_ALEN);
 258
 259         spin_unlock_irqrestore(&orig_hash_lock, flags);
 260
 261         if (!batman_if)
 262                 goto dst_unreach;
 263
 264         if (batman_if->if_active != IF_ACTIVE)
 265                 goto dst_unreach;
 266
 267         memcpy(icmp_packet.orig,
 268                batman_if->net_dev->dev_addr,
 269                ETH_ALEN);
 270
 271         send_raw_packet((unsigned char *)&icmp_packet,
 272                         sizeof(struct icmp_packet),
 273                         batman_if, dstaddr);
 274
 275         goto out;
 276
 277 unlock:
 278         spin_unlock_irqrestore(&orig_hash_lock, flags);
 279 dst_unreach:
 280         icmp_packet.msg_type = DESTINATION_UNREACHABLE;
 281         bat_device_add_packet(device_client, &icmp_packet);
 282 out:
 283         return len;
 284 }
 285
 286 unsigned int bat_device_poll(struct file *file, poll_table *wait)
 287 {
 288         struct device_client *device_client =
 289                 (struct device_client *)file->private_data;
 290
 291         poll_wait(file, &device_client->queue_wait, wait);
 292
 293         if (device_client->queue_len > 0)
 294                 return POLLIN | POLLRDNORM;
 295
 296         return 0;
 297 }
 298
 299 void bat_device_add_packet(struct device_client *device_client,
 300                            struct icmp_packet *icmp_packet)
 301 {
 302         struct device_packet *device_packet;
 303         unsigned long flags;
 304
 305         device_packet = kmalloc(sizeof(struct device_packet), GFP_KERNEL);
 306
 307         if (!device_packet)
 308                 return;
 309
 310         INIT_LIST_HEAD(&device_packet->list);
 311         memcpy(&device_packet->icmp_packet, icmp_packet,
 312                sizeof(struct icmp_packet));
 313
 314         spin_lock_irqsave(&device_client->lock, flags);
 315
 316         /* while waiting for the lock the device_client could have been
 317          * deleted */
 318         if (!device_client_hash[icmp_packet->uid]) {
 319                 spin_unlock_irqrestore(&device_client->lock, flags);
 320                 kfree(device_packet);
 321                 return;
 322         }
 323
 324         list_add_tail(&device_packet->list, &device_client->queue_list);
 325         device_client->queue_len++;
 326
 327         if (device_client->queue_len > 100) {
 328                 device_packet = list_first_entry(&device_client->queue_list,
 329                                                  struct device_packet, list);
 330
 331                 list_del(&device_packet->list);
 332                 kfree(device_packet);
 333                 device_client->queue_len--;
 334         }
 335
 336         spin_unlock_irqrestore(&device_client->lock, flags);
 337
 338         wake_up(&device_client->queue_wait);
 339 }
 340
 341 void bat_device_receive_packet(struct icmp_packet *icmp_packet)
 342 {
 343         struct device_client *hash = device_client_hash[icmp_packet->uid];
 344
 345         if (hash)
 346                 bat_device_add_packet(hash, icmp_packet);
 347 }