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 "originator.h"
  30 #include "hard-interface.h"
  31
  32
  33 static struct socket_client *socket_client_hash[256];
  34
  35 static void bat_socket_add_packet(struct socket_client *socket_client,
  36                                   struct icmp_packet_rr *icmp_packet,
  37                                   size_t icmp_len);
  38
  39 void bat_socket_init(void)
  40 {
  41         memset(socket_client_hash, 0, sizeof(socket_client_hash));
  42 }
  43
  44 static int bat_socket_open(struct inode *inode, struct file *file)
  45 {
  46         unsigned int i;
  47         struct socket_client *socket_client;
  48
  49         nonseekable_open(inode, file);
  50
  51         socket_client = kmalloc(sizeof(struct socket_client), GFP_KERNEL);
  52
  53         if (!socket_client)
  54                 return -ENOMEM;
  55
  56         for (i = 0; i < ARRAY_SIZE(socket_client_hash); i++) {
  57                 if (!socket_client_hash[i]) {
  58                         socket_client_hash[i] = socket_client;
  59                         break;
  60                 }
  61         }
  62
  63         if (i == ARRAY_SIZE(socket_client_hash)) {
  64                 pr_err("Error - can't add another packet client: "
  65                        "maximum number of clients reached\n");
  66                 kfree(socket_client);
  67                 return -EXFULL;
  68         }
  69
  70         INIT_LIST_HEAD(&socket_client->queue_list);
  71         socket_client->queue_len = 0;
  72         socket_client->index = i;
  73         socket_client->bat_priv = inode->i_private;
  74         spin_lock_init(&socket_client->lock);
  75         init_waitqueue_head(&socket_client->queue_wait);
  76
  77         file->private_data = socket_client;
  78
  79         inc_module_count();
  80         return 0;
  81 }
  82
  83 static int bat_socket_release(struct inode *inode, struct file *file)
  84 {
  85         struct socket_client *socket_client = file->private_data;
  86         struct socket_packet *socket_packet;
  87         struct list_head *list_pos, *list_pos_tmp;
  88         unsigned long flags;
  89
  90         spin_lock_irqsave(&socket_client->lock, flags);
  91
  92         /* for all packets in the queue ... */
  93         list_for_each_safe(list_pos, list_pos_tmp, &socket_client->queue_list) {
  94                 socket_packet = list_entry(list_pos,
  95                                            struct socket_packet, list);
  96
  97                 list_del(list_pos);
  98                 kfree(socket_packet);
  99         }
 100
 101         socket_client_hash[socket_client->index] = NULL;
 102         spin_unlock_irqrestore(&socket_client->lock, flags);
 103
 104         kfree(socket_client);
 105         dec_module_count();
 106
 107         return 0;
 108 }
 109
 110 static ssize_t bat_socket_read(struct file *file, char __user *buf,
 111                                size_t count, loff_t *ppos)
 112 {
 113         struct socket_client *socket_client = file->private_data;
 114         struct socket_packet *socket_packet;
 115         size_t packet_len;
 116         int error;
 117         unsigned long flags;
 118
 119         if ((file->f_flags & O_NONBLOCK) && (socket_client->queue_len == 0))
 120                 return -EAGAIN;
 121
 122         if ((!buf) || (count < sizeof(struct icmp_packet)))
 123                 return -EINVAL;
 124
 125         if (!access_ok(VERIFY_WRITE, buf, count))
 126                 return -EFAULT;
 127
 128         error = wait_event_interruptible(socket_client->queue_wait,
 129                                          socket_client->queue_len);
 130
 131         if (error)
 132                 return error;
 133
 134         spin_lock_irqsave(&socket_client->lock, flags);
 135
 136         socket_packet = list_first_entry(&socket_client->queue_list,
 137                                          struct socket_packet, list);
 138         list_del(&socket_packet->list);
 139         socket_client->queue_len--;
 140
 141         spin_unlock_irqrestore(&socket_client->lock, flags);
 142
 143         error = __copy_to_user(buf, &socket_packet->icmp_packet,
 144                                socket_packet->icmp_len);
 145
 146         packet_len = socket_packet->icmp_len;
 147         kfree(socket_packet);
 148
 149         if (error)
 150                 return -EFAULT;
 151
 152         return packet_len;
 153 }
 154
 155 static ssize_t bat_socket_write(struct file *file, const char __user *buff,
 156                                 size_t len, loff_t *off)
 157 {
 158         struct socket_client *socket_client = file->private_data;
 159         struct bat_priv *bat_priv = socket_client->bat_priv;
 160         struct sk_buff *skb;
 161         struct icmp_packet_rr *icmp_packet;
 162
 163         struct orig_node *orig_node;
 164         struct batman_if *batman_if;
 165         size_t packet_len = sizeof(struct icmp_packet);
 166         uint8_t dstaddr[ETH_ALEN];
 167         unsigned long flags;
 168
 169         if (len < sizeof(struct icmp_packet)) {
 170                 bat_dbg(DBG_BATMAN, bat_priv,
 171                         "Error - can't send packet from char device: "
 172                         "invalid packet size\n");
 173                 return -EINVAL;
 174         }
 175
 176         if (!bat_priv->primary_if)
 177                 return -EFAULT;
 178
 179         if (len >= sizeof(struct icmp_packet_rr))
 180                 packet_len = sizeof(struct icmp_packet_rr);
 181
 182         skb = dev_alloc_skb(packet_len + sizeof(struct ethhdr));
 183         if (!skb)
 184                 return -ENOMEM;
 185
 186         skb_reserve(skb, sizeof(struct ethhdr));
 187         icmp_packet = (struct icmp_packet_rr *)skb_put(skb, packet_len);
 188
 189         if (!access_ok(VERIFY_READ, buff, packet_len)) {
 190                 len = -EFAULT;
 191                 goto free_skb;
 192         }
 193
 194         if (__copy_from_user(icmp_packet, buff, packet_len)) {
 195                 len = -EFAULT;
 196                 goto free_skb;
 197         }
 198
 199         if (icmp_packet->packet_type != BAT_ICMP) {
 200                 bat_dbg(DBG_BATMAN, bat_priv,
 201                         "Error - can't send packet from char device: "
 202                         "got bogus packet type (expected: BAT_ICMP)\n");
 203                 len = -EINVAL;
 204                 goto free_skb;
 205         }
 206
 207         if (icmp_packet->msg_type != ECHO_REQUEST) {
 208                 bat_dbg(DBG_BATMAN, bat_priv,
 209                         "Error - can't send packet from char device: "
 210                         "got bogus message type (expected: ECHO_REQUEST)\n");
 211                 len = -EINVAL;
 212                 goto free_skb;
 213         }
 214
 215         icmp_packet->uid = socket_client->index;
 216
 217         if (icmp_packet->version != COMPAT_VERSION) {
 218                 icmp_packet->msg_type = PARAMETER_PROBLEM;
 219                 icmp_packet->ttl = COMPAT_VERSION;
 220                 bat_socket_add_packet(socket_client, icmp_packet, packet_len);
 221                 goto free_skb;
 222         }
 223
 224         if (atomic_read(&bat_priv->mesh_state) != MESH_ACTIVE)
 225                 goto dst_unreach;
 226
 227         spin_lock_irqsave(&bat_priv->orig_hash_lock, flags);
 228         orig_node = ((struct orig_node *)hash_find(bat_priv->orig_hash,
 229                                                    compare_orig,
 230                                                    icmp_packet->dst));
 231
 232         if (!orig_node)
 233                 goto unlock;
 234
 235         if (!orig_node->router)
 236                 goto unlock;
 237
 238         batman_if = orig_node->router->if_incoming;
 239         memcpy(dstaddr, orig_node->router->addr, ETH_ALEN);
 240
 241         spin_unlock_irqrestore(&bat_priv->orig_hash_lock, flags);
 242
 243         if (!batman_if)
 244                 goto dst_unreach;
 245
 246         if (batman_if->if_status != IF_ACTIVE)
 247                 goto dst_unreach;
 248
 249         memcpy(icmp_packet->orig,
 250                bat_priv->primary_if->net_dev->dev_addr, ETH_ALEN);
 251
 252         if (packet_len == sizeof(struct icmp_packet_rr))
 253                 memcpy(icmp_packet->rr, batman_if->net_dev->dev_addr, ETH_ALEN);
 254
 255
 256         send_skb_packet(skb, batman_if, dstaddr);
 257
 258         goto out;
 259
 260 unlock:
 261         spin_unlock_irqrestore(&bat_priv->orig_hash_lock, flags);
 262 dst_unreach:
 263         icmp_packet->msg_type = DESTINATION_UNREACHABLE;
 264         bat_socket_add_packet(socket_client, icmp_packet, packet_len);
 265 free_skb:
 266         kfree_skb(skb);
 267 out:
 268         return len;
 269 }
 270
 271 static unsigned int bat_socket_poll(struct file *file, poll_table *wait)
 272 {
 273         struct socket_client *socket_client = file->private_data;
 274
 275         poll_wait(file, &socket_client->queue_wait, wait);
 276
 277         if (socket_client->queue_len > 0)
 278                 return POLLIN | POLLRDNORM;
 279
 280         return 0;
 281 }
 282
 283 static const struct file_operations fops = {
 284         .owner = THIS_MODULE,
 285         .open = bat_socket_open,
 286         .release = bat_socket_release,
 287         .read = bat_socket_read,
 288         .write = bat_socket_write,
 289         .poll = bat_socket_poll,
 290         .llseek = no_llseek,
 291 };
 292
 293 int bat_socket_setup(struct bat_priv *bat_priv)
 294 {
 295         struct dentry *d;
 296
 297         if (!bat_priv->debug_dir)
 298                 goto err;
 299
 300         d = debugfs_create_file(ICMP_SOCKET, S_IFREG | S_IWUSR | S_IRUSR,
 301                                 bat_priv->debug_dir, bat_priv, &fops);
 302         if (d)
 303                 goto err;
 304
 305         return 0;
 306
 307 err:
 308         return 1;
 309 }
 310
 311 static void bat_socket_add_packet(struct socket_client *socket_client,
 312                                   struct icmp_packet_rr *icmp_packet,
 313                                   size_t icmp_len)
 314 {
 315         struct socket_packet *socket_packet;
 316         unsigned long flags;
 317
 318         socket_packet = kmalloc(sizeof(struct socket_packet), GFP_ATOMIC);
 319
 320         if (!socket_packet)
 321                 return;
 322
 323         INIT_LIST_HEAD(&socket_packet->list);
 324         memcpy(&socket_packet->icmp_packet, icmp_packet, icmp_len);
 325         socket_packet->icmp_len = icmp_len;
 326
 327         spin_lock_irqsave(&socket_client->lock, flags);
 328
 329         /* while waiting for the lock the socket_client could have been
 330          * deleted */
 331         if (!socket_client_hash[icmp_packet->uid]) {
 332                 spin_unlock_irqrestore(&socket_client->lock, flags);
 333                 kfree(socket_packet);
 334                 return;
 335         }
 336
 337         list_add_tail(&socket_packet->list, &socket_client->queue_list);
 338         socket_client->queue_len++;
 339
 340         if (socket_client->queue_len > 100) {
 341                 socket_packet = list_first_entry(&socket_client->queue_list,
 342                                                  struct socket_packet, list);
 343
 344                 list_del(&socket_packet->list);
 345                 kfree(socket_packet);
 346                 socket_client->queue_len--;
 347         }
 348
 349         spin_unlock_irqrestore(&socket_client->lock, flags);
 350
 351         wake_up(&socket_client->queue_wait);
 352 }
 353
 354 void bat_socket_receive_packet(struct icmp_packet_rr *icmp_packet,
 355                                size_t icmp_len)
 356 {
 357         struct socket_client *hash = socket_client_hash[icmp_packet->uid];
 358
 359         if (hash)
 360                 bat_socket_add_packet(hash, icmp_packet, icmp_len);
 361 }