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         memset(device_client_hash, 0, sizeof(device_client_hash));
  48 }
  49
  50 int bat_device_setup(void)
  51 {
  52         int tmp_major;
  53
  54         if (Major)
  55                 return 1;
  56
  57         /* register our device - kernel assigns a free major number */
  58         tmp_major = register_chrdev(0, DRIVER_DEVICE, &fops);
  59         if (tmp_major < 0) {
  60                 printk(KERN_ERR "batman-adv:"
  61                        "Registering the character device failed with %d\n",
  62                           tmp_major);
  63                 return 0;
  64         }
  65
  66         batman_class = class_create(THIS_MODULE, "batman-adv");
  67
  68         if (IS_ERR(batman_class)) {
  69                 printk(KERN_ERR "batman-adv:"
  70                        "Could not register class 'batman-adv'\n");
  71                 return 0;
  72         }
  73
  74         device_create(batman_class, NULL, MKDEV(tmp_major, 0), NULL,
  75                       "batman-adv");
  76
  77         Major = tmp_major;
  78         return 1;
  79 }
  80
  81 void bat_device_destroy(void)
  82 {
  83         if (!Major)
  84                 return;
  85
  86         device_destroy(batman_class, MKDEV(Major, 0));
  87         class_destroy(batman_class);
  88
  89         /* Unregister the device */
  90         unregister_chrdev(Major, DRIVER_DEVICE);
  91
  92         Major = 0;
  93 }
  94
  95 int bat_device_open(struct inode *inode, struct file *file)
  96 {
  97         unsigned int i;
  98         struct device_client *device_client;
  99
 100         device_client = kmalloc(sizeof(struct device_client), GFP_KERNEL);
 101
 102         if (!device_client)
 103                 return -ENOMEM;
 104
 105         for (i = 0; i < ARRAY_SIZE(device_client_hash); i++) {
 106                 if (!device_client_hash[i]) {
 107                         device_client_hash[i] = device_client;
 108                         break;
 109                 }
 110         }
 111
 112         if (i == ARRAY_SIZE(device_client_hash)) {
 113                 printk(KERN_ERR "batman-adv:"
 114                        "Error - can't add another packet client: "
 115                        "maximum number of clients reached\n");
 116                 kfree(device_client);
 117                 return -EXFULL;
 118         }
 119
 120         INIT_LIST_HEAD(&device_client->queue_list);
 121         device_client->queue_len = 0;
 122         device_client->index = i;
 123         spin_lock_init(&device_client->lock);
 124         init_waitqueue_head(&device_client->queue_wait);
 125
 126         file->private_data = device_client;
 127
 128         inc_module_count();
 129         return 0;
 130 }
 131
 132 int bat_device_release(struct inode *inode, struct file *file)
 133 {
 134         struct device_client *device_client =
 135                 (struct device_client *)file->private_data;
 136         struct device_packet *device_packet;
 137         struct list_head *list_pos, *list_pos_tmp;
 138         unsigned long flags;
 139
 140         spin_lock_irqsave(&device_client->lock, flags);
 141
 142         /* for all packets in the queue ... */
 143         list_for_each_safe(list_pos, list_pos_tmp, &device_client->queue_list) {
 144                 device_packet = list_entry(list_pos,
 145                                            struct device_packet, list);
 146
 147                 list_del(list_pos);
 148                 kfree(device_packet);
 149         }
 150
 151         device_client_hash[device_client->index] = NULL;
 152         spin_unlock_irqrestore(&device_client->lock, flags);
 153
 154         kfree(device_client);
 155         dec_module_count();
 156
 157         return 0;
 158 }
 159
 160 ssize_t bat_device_read(struct file *file, char __user *buf, size_t count,
 161                         loff_t *ppos)
 162 {
 163         struct device_client *device_client =
 164                 (struct device_client *)file->private_data;
 165         struct device_packet *device_packet;
 166         int error;
 167         unsigned long flags;
 168
 169         if ((file->f_flags & O_NONBLOCK) && (device_client->queue_len == 0))
 170                 return -EAGAIN;
 171
 172         if ((!buf) || (count < sizeof(struct icmp_packet)))
 173                 return -EINVAL;
 174
 175         if (!access_ok(VERIFY_WRITE, buf, count))
 176                 return -EFAULT;
 177
 178         error = wait_event_interruptible(device_client->queue_wait,
 179                                          device_client->queue_len);
 180
 181         if (error)
 182                 return error;
 183
 184         spin_lock_irqsave(&device_client->lock, flags);
 185
 186         device_packet = list_first_entry(&device_client->queue_list,
 187                                          struct device_packet, list);
 188         list_del(&device_packet->list);
 189         device_client->queue_len--;
 190
 191         spin_unlock_irqrestore(&device_client->lock, flags);
 192
 193         error = __copy_to_user(buf, &device_packet->icmp_packet,
 194                                sizeof(struct icmp_packet));
 195
 196         kfree(device_packet);
 197
 198         if (error)
 199                 return error;
 200
 201         return sizeof(struct icmp_packet);
 202 }
 203
 204 ssize_t bat_device_write(struct file *file, const char __user *buff,
 205                          size_t len, loff_t *off)
 206 {
 207         struct device_client *device_client =
 208                 (struct device_client *)file->private_data;
 209         struct icmp_packet icmp_packet;
 210         struct orig_node *orig_node;
 211         struct batman_if *batman_if;
 212         uint8_t dstaddr[ETH_ALEN];
 213         unsigned long flags;
 214
 215         if (len < sizeof(struct icmp_packet)) {
 216                 bat_dbg(DBG_BATMAN, "batman-adv:"
 217                         "Error - can't send packet from char device: "
 218                         "invalid packet size\n");
 219                 return -EINVAL;
 220         }
 221
 222         if (!access_ok(VERIFY_READ, buff, sizeof(struct icmp_packet)))
 223                 return -EFAULT;
 224
 225         if (__copy_from_user(&icmp_packet, buff, sizeof(icmp_packet)))
 226                 return -EFAULT;
 227
 228         if (icmp_packet.packet_type != BAT_ICMP) {
 229                 bat_dbg(DBG_BATMAN, "batman-adv:"
 230                         "Error - can't send packet from char device: "
 231                         "got bogus packet type (expected: BAT_ICMP)\n");
 232                 return -EINVAL;
 233         }
 234
 235         if (icmp_packet.msg_type != ECHO_REQUEST) {
 236                 bat_dbg(DBG_BATMAN, "batman-adv:"
 237                         "Error - can't send packet from char device: "
 238                         "got bogus message type (expected: ECHO_REQUEST)\n");
 239                 return -EINVAL;
 240         }
 241
 242         icmp_packet.uid = device_client->index;
 243
 244         if (icmp_packet.version != COMPAT_VERSION) {
 245                 icmp_packet.msg_type = PARAMETER_PROBLEM;
 246                 icmp_packet.ttl = COMPAT_VERSION;
 247                 bat_device_add_packet(device_client, &icmp_packet);
 248                 goto out;
 249         }
 250
 251         if (atomic_read(&module_state) != MODULE_ACTIVE)
 252                 goto dst_unreach;
 253
 254         spin_lock_irqsave(&orig_hash_lock, flags);
 255         orig_node = ((struct orig_node *)hash_find(orig_hash, icmp_packet.dst));
 256
 257         if (!orig_node)
 258                 goto unlock;
 259
 260         if (!orig_node->router)
 261                 goto unlock;
 262
 263         batman_if = orig_node->router->if_incoming;
 264         memcpy(dstaddr, orig_node->router->addr, ETH_ALEN);
 265
 266         spin_unlock_irqrestore(&orig_hash_lock, flags);
 267
 268         if (!batman_if)
 269                 goto dst_unreach;
 270
 271         if (batman_if->if_status != IF_ACTIVE)
 272                 goto dst_unreach;
 273
 274         memcpy(icmp_packet.orig,
 275                batman_if->net_dev->dev_addr,
 276                ETH_ALEN);
 277
 278         send_raw_packet((unsigned char *)&icmp_packet,
 279                         sizeof(struct icmp_packet),
 280                         batman_if, dstaddr);
 281
 282         goto out;
 283
 284 unlock:
 285         spin_unlock_irqrestore(&orig_hash_lock, flags);
 286 dst_unreach:
 287         icmp_packet.msg_type = DESTINATION_UNREACHABLE;
 288         bat_device_add_packet(device_client, &icmp_packet);
 289 out:
 290         return len;
 291 }
 292
 293 unsigned int bat_device_poll(struct file *file, poll_table *wait)
 294 {
 295         struct device_client *device_client =
 296                 (struct device_client *)file->private_data;
 297
 298         poll_wait(file, &device_client->queue_wait, wait);
 299
 300         if (device_client->queue_len > 0)
 301                 return POLLIN | POLLRDNORM;
 302
 303         return 0;
 304 }
 305
 306 void bat_device_add_packet(struct device_client *device_client,
 307                            struct icmp_packet *icmp_packet)
 308 {
 309         struct device_packet *device_packet;
 310         unsigned long flags;
 311
 312         device_packet = kmalloc(sizeof(struct device_packet), GFP_ATOMIC);
 313
 314         if (!device_packet)
 315                 return;
 316
 317         INIT_LIST_HEAD(&device_packet->list);
 318         memcpy(&device_packet->icmp_packet, icmp_packet,
 319                sizeof(struct icmp_packet));
 320
 321         spin_lock_irqsave(&device_client->lock, flags);
 322
 323         /* while waiting for the lock the device_client could have been
 324          * deleted */
 325         if (!device_client_hash[icmp_packet->uid]) {
 326                 spin_unlock_irqrestore(&device_client->lock, flags);
 327                 kfree(device_packet);
 328                 return;
 329         }
 330
 331         list_add_tail(&device_packet->list, &device_client->queue_list);
 332         device_client->queue_len++;
 333
 334         if (device_client->queue_len > 100) {
 335                 device_packet = list_first_entry(&device_client->queue_list,
 336                                                  struct device_packet, list);
 337
 338                 list_del(&device_packet->list);
 339                 kfree(device_packet);
 340                 device_client->queue_len--;
 341         }
 342
 343         spin_unlock_irqrestore(&device_client->lock, flags);
 344
 345         wake_up(&device_client->queue_wait);
 346 }
 347
 348 void bat_device_receive_packet(struct icmp_packet *icmp_packet)
 349 {
 350         struct device_client *hash = device_client_hash[icmp_packet->uid];
 351
 352         if (hash)
 353                 bat_device_add_packet(hash, icmp_packet);
 354 }