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 sk_buff *skb;
 158         struct icmp_packet_rr *icmp_packet;
 159         struct orig_node *orig_node;
 160         struct batman_if *batman_if;
 161         size_t packet_len = sizeof(struct icmp_packet);
 162         uint8_t dstaddr[ETH_ALEN];
 163         unsigned long flags;
 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(&module_state) != MODULE_ACTIVE)
 221                 goto dst_unreach;
 222
 223         spin_lock_irqsave(&orig_hash_lock, flags);
 224         orig_node = (struct orig_node *)hash_find(orig_hash, icmp_packet->dst);
 225
 226         if (!orig_node)
 227                 goto unlock;
 228
 229         if (!orig_node->router)
 230                 goto unlock;
 231
 232         batman_if = orig_node->router->if_incoming;
 233         memcpy(dstaddr, orig_node->router->addr, ETH_ALEN);
 234
 235         spin_unlock_irqrestore(&orig_hash_lock, flags);
 236
 237         if (!batman_if)
 238                 goto dst_unreach;
 239
 240         if (batman_if->if_status != IF_ACTIVE)
 241                 goto dst_unreach;
 242
 243         memcpy(icmp_packet->orig,
 244                bat_priv->primary_if->net_dev->dev_addr, ETH_ALEN);
 245
 246         if (packet_len == sizeof(struct icmp_packet_rr))
 247                 memcpy(icmp_packet->rr, batman_if->net_dev->dev_addr, ETH_ALEN);
 248
 249
 250         send_skb_packet(skb, batman_if, dstaddr);
 251
 252         goto out;
 253
 254 unlock:
 255         spin_unlock_irqrestore(&orig_hash_lock, flags);
 256 dst_unreach:
 257         icmp_packet->msg_type = DESTINATION_UNREACHABLE;
 258         bat_socket_add_packet(socket_client, icmp_packet, packet_len);
 259 free_skb:
 260         kfree_skb(skb);
 261 out:
 262         return len;
 263 }
 264
 265 static unsigned int bat_socket_poll(struct file *file, poll_table *wait)
 266 {
 267         struct socket_client *socket_client = file->private_data;
 268
 269         poll_wait(file, &socket_client->queue_wait, wait);
 270
 271         if (socket_client->queue_len > 0)
 272                 return POLLIN | POLLRDNORM;
 273
 274         return 0;
 275 }
 276
 277 static const struct file_operations fops = {
 278         .owner = THIS_MODULE,
 279         .open = bat_socket_open,
 280         .release = bat_socket_release,
 281         .read = bat_socket_read,
 282         .write = bat_socket_write,
 283         .poll = bat_socket_poll,
 284 };
 285
 286 int bat_socket_setup(struct bat_priv *bat_priv)
 287 {
 288         struct dentry *d;
 289
 290         if (!bat_priv->debug_dir)
 291                 goto err;
 292
 293         d = debugfs_create_file(ICMP_SOCKET, S_IFREG | S_IWUSR | S_IRUSR,
 294                                 bat_priv->debug_dir, bat_priv, &fops);
 295         if (d)
 296                 goto err;
 297
 298         return 0;
 299
 300 err:
 301         return 1;
 302 }
 303
 304 static void bat_socket_add_packet(struct socket_client *socket_client,
 305                                   struct icmp_packet_rr *icmp_packet,
 306                                   size_t icmp_len)
 307 {
 308         struct socket_packet *socket_packet;
 309         unsigned long flags;
 310
 311         socket_packet = kmalloc(sizeof(struct socket_packet), GFP_ATOMIC);
 312
 313         if (!socket_packet)
 314                 return;
 315
 316         INIT_LIST_HEAD(&socket_packet->list);
 317         memcpy(&socket_packet->icmp_packet, icmp_packet, icmp_len);
 318         socket_packet->icmp_len = icmp_len;
 319
 320         spin_lock_irqsave(&socket_client->lock, flags);
 321
 322         /* while waiting for the lock the socket_client could have been
 323          * deleted */
 324         if (!socket_client_hash[icmp_packet->uid]) {
 325                 spin_unlock_irqrestore(&socket_client->lock, flags);
 326                 kfree(socket_packet);
 327                 return;
 328         }
 329
 330         list_add_tail(&socket_packet->list, &socket_client->queue_list);
 331         socket_client->queue_len++;
 332
 333         if (socket_client->queue_len > 100) {
 334                 socket_packet = list_first_entry(&socket_client->queue_list,
 335                                                  struct socket_packet, list);
 336
 337                 list_del(&socket_packet->list);
 338                 kfree(socket_packet);
 339                 socket_client->queue_len--;
 340         }
 341
 342         spin_unlock_irqrestore(&socket_client->lock, flags);
 343
 344         wake_up(&socket_client->queue_wait);
 345 }
 346
 347 void bat_socket_receive_packet(struct icmp_packet_rr *icmp_packet,
 348                                size_t icmp_len)
 349 {
 350         struct socket_client *hash = socket_client_hash[icmp_packet->uid];
 351
 352         if (hash)
 353                 bat_socket_add_packet(hash, icmp_packet, icmp_len);
 354 }