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         spin_lock_init(&socket_client->lock);
  71         init_waitqueue_head(&socket_client->queue_wait);
  72
  73         file->private_data = socket_client;
  74
  75         inc_module_count();
  76         return 0;
  77 }
  78
  79 static int bat_socket_release(struct inode *inode, struct file *file)
  80 {
  81         struct socket_client *socket_client = file->private_data;
  82         struct socket_packet *socket_packet;
  83         struct list_head *list_pos, *list_pos_tmp;
  84         unsigned long flags;
  85
  86         spin_lock_irqsave(&socket_client->lock, flags);
  87
  88         /* for all packets in the queue ... */
  89         list_for_each_safe(list_pos, list_pos_tmp, &socket_client->queue_list) {
  90                 socket_packet = list_entry(list_pos,
  91                                            struct socket_packet, list);
  92
  93                 list_del(list_pos);
  94                 kfree(socket_packet);
  95         }
  96
  97         socket_client_hash[socket_client->index] = NULL;
  98         spin_unlock_irqrestore(&socket_client->lock, flags);
  99
 100         kfree(socket_client);
 101         dec_module_count();
 102
 103         return 0;
 104 }
 105
 106 static ssize_t bat_socket_read(struct file *file, char __user *buf,
 107                                size_t count, loff_t *ppos)
 108 {
 109         struct socket_client *socket_client = file->private_data;
 110         struct socket_packet *socket_packet;
 111         size_t packet_len;
 112         int error;
 113         unsigned long flags;
 114
 115         if ((file->f_flags & O_NONBLOCK) && (socket_client->queue_len == 0))
 116                 return -EAGAIN;
 117
 118         if ((!buf) || (count < sizeof(struct icmp_packet)))
 119                 return -EINVAL;
 120
 121         if (!access_ok(VERIFY_WRITE, buf, count))
 122                 return -EFAULT;
 123
 124         error = wait_event_interruptible(socket_client->queue_wait,
 125                                          socket_client->queue_len);
 126
 127         if (error)
 128                 return error;
 129
 130         spin_lock_irqsave(&socket_client->lock, flags);
 131
 132         socket_packet = list_first_entry(&socket_client->queue_list,
 133                                          struct socket_packet, list);
 134         list_del(&socket_packet->list);
 135         socket_client->queue_len--;
 136
 137         spin_unlock_irqrestore(&socket_client->lock, flags);
 138
 139         error = __copy_to_user(buf, &socket_packet->icmp_packet,
 140                                socket_packet->icmp_len);
 141
 142         packet_len = socket_packet->icmp_len;
 143         kfree(socket_packet);
 144
 145         if (error)
 146                 return -EFAULT;
 147
 148         return packet_len;
 149 }
 150
 151 static ssize_t bat_socket_write(struct file *file, const char __user *buff,
 152                                 size_t len, loff_t *off)
 153 {
 154         /* FIXME: each orig_node->batman_if will be attached to a softif */
 155         struct bat_priv *bat_priv = netdev_priv(soft_device);
 156         struct socket_client *socket_client = file->private_data;
 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 (len >= sizeof(struct icmp_packet_rr))
 172                 packet_len = sizeof(struct icmp_packet_rr);
 173
 174         if (!access_ok(VERIFY_READ, buff, packet_len))
 175                 return -EFAULT;
 176
 177         if (__copy_from_user(&icmp_packet, buff, packet_len))
 178                 return -EFAULT;
 179
 180         if (icmp_packet.packet_type != BAT_ICMP) {
 181                 bat_dbg(DBG_BATMAN, bat_priv,
 182                         "Error - can't send packet from char device: "
 183                         "got bogus packet type (expected: BAT_ICMP)\n");
 184                 return -EINVAL;
 185         }
 186
 187         if (icmp_packet.msg_type != ECHO_REQUEST) {
 188                 bat_dbg(DBG_BATMAN, bat_priv,
 189                         "Error - can't send packet from char device: "
 190                         "got bogus message type (expected: ECHO_REQUEST)\n");
 191                 return -EINVAL;
 192         }
 193
 194         icmp_packet.uid = socket_client->index;
 195
 196         if (icmp_packet.version != COMPAT_VERSION) {
 197                 icmp_packet.msg_type = PARAMETER_PROBLEM;
 198                 icmp_packet.ttl = COMPAT_VERSION;
 199                 bat_socket_add_packet(socket_client, &icmp_packet, packet_len);
 200                 goto out;
 201         }
 202
 203         if (atomic_read(&module_state) != MODULE_ACTIVE)
 204                 goto dst_unreach;
 205
 206         spin_lock_irqsave(&orig_hash_lock, flags);
 207         orig_node = ((struct orig_node *)hash_find(orig_hash, icmp_packet.dst));
 208
 209         if (!orig_node)
 210                 goto unlock;
 211
 212         if (!orig_node->router)
 213                 goto unlock;
 214
 215         batman_if = orig_node->router->if_incoming;
 216         memcpy(dstaddr, orig_node->router->addr, ETH_ALEN);
 217
 218         spin_unlock_irqrestore(&orig_hash_lock, flags);
 219
 220         if (!batman_if)
 221                 goto dst_unreach;
 222
 223         if (batman_if->if_status != IF_ACTIVE)
 224                 goto dst_unreach;
 225
 226         memcpy(icmp_packet.orig, batman_if->net_dev->dev_addr, ETH_ALEN);
 227
 228         if (packet_len == sizeof(struct icmp_packet_rr))
 229                 memcpy(icmp_packet.rr, batman_if->net_dev->dev_addr, ETH_ALEN);
 230
 231         send_raw_packet((unsigned char *)&icmp_packet,
 232                         packet_len, batman_if, dstaddr);
 233
 234         goto out;
 235
 236 unlock:
 237         spin_unlock_irqrestore(&orig_hash_lock, flags);
 238 dst_unreach:
 239         icmp_packet.msg_type = DESTINATION_UNREACHABLE;
 240         bat_socket_add_packet(socket_client, &icmp_packet, packet_len);
 241 out:
 242         return len;
 243 }
 244
 245 static unsigned int bat_socket_poll(struct file *file, poll_table *wait)
 246 {
 247         struct socket_client *socket_client = file->private_data;
 248
 249         poll_wait(file, &socket_client->queue_wait, wait);
 250
 251         if (socket_client->queue_len > 0)
 252                 return POLLIN | POLLRDNORM;
 253
 254         return 0;
 255 }
 256
 257 static const struct file_operations fops = {
 258         .owner = THIS_MODULE,
 259         .open = bat_socket_open,
 260         .release = bat_socket_release,
 261         .read = bat_socket_read,
 262         .write = bat_socket_write,
 263         .poll = bat_socket_poll,
 264 };
 265
 266 int bat_socket_setup(struct bat_priv *bat_priv)
 267 {
 268         struct dentry *d;
 269
 270         if (!bat_priv->debug_dir)
 271                 goto err;
 272
 273         d = debugfs_create_file(ICMP_SOCKET, S_IFREG | S_IWUSR | S_IRUSR,
 274                                 bat_priv->debug_dir, NULL, &fops);
 275         if (d)
 276                 goto err;
 277
 278         return 0;
 279
 280 err:
 281         return 1;
 282 }
 283
 284 static void bat_socket_add_packet(struct socket_client *socket_client,
 285                                   struct icmp_packet_rr *icmp_packet,
 286                                   size_t icmp_len)
 287 {
 288         struct socket_packet *socket_packet;
 289         unsigned long flags;
 290
 291         socket_packet = kmalloc(sizeof(struct socket_packet), GFP_ATOMIC);
 292
 293         if (!socket_packet)
 294                 return;
 295
 296         INIT_LIST_HEAD(&socket_packet->list);
 297         memcpy(&socket_packet->icmp_packet, icmp_packet, icmp_len);
 298         socket_packet->icmp_len = icmp_len;
 299
 300         spin_lock_irqsave(&socket_client->lock, flags);
 301
 302         /* while waiting for the lock the socket_client could have been
 303          * deleted */
 304         if (!socket_client_hash[icmp_packet->uid]) {
 305                 spin_unlock_irqrestore(&socket_client->lock, flags);
 306                 kfree(socket_packet);
 307                 return;
 308         }
 309
 310         list_add_tail(&socket_packet->list, &socket_client->queue_list);
 311         socket_client->queue_len++;
 312
 313         if (socket_client->queue_len > 100) {
 314                 socket_packet = list_first_entry(&socket_client->queue_list,
 315                                                  struct socket_packet, list);
 316
 317                 list_del(&socket_packet->list);
 318                 kfree(socket_packet);
 319                 socket_client->queue_len--;
 320         }
 321
 322         spin_unlock_irqrestore(&socket_client->lock, flags);
 323
 324         wake_up(&socket_client->queue_wait);
 325 }
 326
 327 void bat_socket_receive_packet(struct icmp_packet_rr *icmp_packet,
 328                                size_t icmp_len)
 329 {
 330         struct socket_client *hash = socket_client_hash[icmp_packet->uid];
 331
 332         if (hash)
 333                 bat_socket_add_packet(hash, icmp_packet, icmp_len);
 334 }