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 <linux/debugfs.h>
  23 #include <linux/slab.h>
  24 #include "main.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 *icmp_packet);
  36
  37 void bat_socket_init(void)
  38 {
  39         memset(socket_client_hash, 0, sizeof(socket_client_hash));
  40 }
  41
  42 static int bat_socket_open(struct inode *inode, struct file *file)
  43 {
  44         unsigned int i;
  45         struct socket_client *socket_client;
  46
  47         socket_client = kmalloc(sizeof(struct socket_client), GFP_KERNEL);
  48
  49         if (!socket_client)
  50                 return -ENOMEM;
  51
  52         for (i = 0; i < ARRAY_SIZE(socket_client_hash); i++) {
  53                 if (!socket_client_hash[i]) {
  54                         socket_client_hash[i] = socket_client;
  55                         break;
  56                 }
  57         }
  58
  59         if (i == ARRAY_SIZE(socket_client_hash)) {
  60                 printk(KERN_ERR "batman-adv:"
  61                        "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 =
  82                 (struct 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 =
 111                 (struct socket_client *)file->private_data;
 112         struct socket_packet *socket_packet;
 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                                sizeof(struct icmp_packet));
 142
 143         kfree(socket_packet);
 144
 145         if (error)
 146                 return -EFAULT;
 147
 148         return sizeof(struct icmp_packet);
 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         struct socket_client *socket_client =
 155                 (struct socket_client *)file->private_data;
 156         struct icmp_packet icmp_packet;
 157         struct orig_node *orig_node;
 158         struct batman_if *batman_if;
 159         uint8_t dstaddr[ETH_ALEN];
 160         unsigned long flags;
 161
 162         if (len < sizeof(struct icmp_packet)) {
 163                 bat_dbg(DBG_BATMAN, "batman-adv:"
 164                         "Error - can't send packet from char device: "
 165                         "invalid packet size\n");
 166                 return -EINVAL;
 167         }
 168
 169         if (!access_ok(VERIFY_READ, buff, sizeof(struct icmp_packet)))
 170                 return -EFAULT;
 171
 172         if (__copy_from_user(&icmp_packet, buff, sizeof(icmp_packet)))
 173                 return -EFAULT;
 174
 175         if (icmp_packet.packet_type != BAT_ICMP) {
 176                 bat_dbg(DBG_BATMAN, "batman-adv:"
 177                         "Error - can't send packet from char device: "
 178                         "got bogus packet type (expected: BAT_ICMP)\n");
 179                 return -EINVAL;
 180         }
 181
 182         if (icmp_packet.msg_type != ECHO_REQUEST) {
 183                 bat_dbg(DBG_BATMAN, "batman-adv:"
 184                         "Error - can't send packet from char device: "
 185                         "got bogus message type (expected: ECHO_REQUEST)\n");
 186                 return -EINVAL;
 187         }
 188
 189         icmp_packet.uid = socket_client->index;
 190
 191         if (icmp_packet.version != COMPAT_VERSION) {
 192                 icmp_packet.msg_type = PARAMETER_PROBLEM;
 193                 icmp_packet.ttl = COMPAT_VERSION;
 194                 bat_socket_add_packet(socket_client, &icmp_packet);
 195                 goto out;
 196         }
 197
 198         if (atomic_read(&module_state) != MODULE_ACTIVE)
 199                 goto dst_unreach;
 200
 201         spin_lock_irqsave(&orig_hash_lock, flags);
 202         orig_node = ((struct orig_node *)hash_find(orig_hash, icmp_packet.dst));
 203
 204         if (!orig_node)
 205                 goto unlock;
 206
 207         if (!orig_node->router)
 208                 goto unlock;
 209
 210         batman_if = orig_node->router->if_incoming;
 211         memcpy(dstaddr, orig_node->router->addr, ETH_ALEN);
 212
 213         spin_unlock_irqrestore(&orig_hash_lock, flags);
 214
 215         if (!batman_if)
 216                 goto dst_unreach;
 217
 218         if (batman_if->if_status != IF_ACTIVE)
 219                 goto dst_unreach;
 220
 221         memcpy(icmp_packet.orig,
 222                batman_if->net_dev->dev_addr,
 223                ETH_ALEN);
 224
 225         send_raw_packet((unsigned char *)&icmp_packet,
 226                         sizeof(struct icmp_packet),
 227                         batman_if, dstaddr);
 228
 229         goto out;
 230
 231 unlock:
 232         spin_unlock_irqrestore(&orig_hash_lock, flags);
 233 dst_unreach:
 234         icmp_packet.msg_type = DESTINATION_UNREACHABLE;
 235         bat_socket_add_packet(socket_client, &icmp_packet);
 236 out:
 237         return len;
 238 }
 239
 240 static unsigned int bat_socket_poll(struct file *file, poll_table *wait)
 241 {
 242         struct socket_client *socket_client =
 243                 (struct socket_client *)file->private_data;
 244
 245         poll_wait(file, &socket_client->queue_wait, wait);
 246
 247         if (socket_client->queue_len > 0)
 248                 return POLLIN | POLLRDNORM;
 249
 250         return 0;
 251 }
 252
 253 static const struct file_operations fops = {
 254         .owner = THIS_MODULE,
 255         .open = bat_socket_open,
 256         .release = bat_socket_release,
 257         .read = bat_socket_read,
 258         .write = bat_socket_write,
 259         .poll = bat_socket_poll,
 260 };
 261
 262 int bat_socket_setup(struct bat_priv *bat_priv)
 263 {
 264         struct dentry *d;
 265
 266         if (!bat_priv->debug_dir)
 267                 goto err;
 268
 269         d = debugfs_create_file(ICMP_SOCKET, S_IFREG | S_IWUSR | S_IRUSR,
 270                                 bat_priv->debug_dir, NULL, &fops);
 271         if (d)
 272                 goto err;
 273
 274         return 0;
 275
 276 err:
 277         return 1;
 278 }
 279
 280 static void bat_socket_add_packet(struct socket_client *socket_client,
 281                                   struct icmp_packet *icmp_packet)
 282 {
 283         struct socket_packet *socket_packet;
 284         unsigned long flags;
 285
 286         socket_packet = kmalloc(sizeof(struct socket_packet), GFP_ATOMIC);
 287
 288         if (!socket_packet)
 289                 return;
 290
 291         INIT_LIST_HEAD(&socket_packet->list);
 292         memcpy(&socket_packet->icmp_packet, icmp_packet,
 293                sizeof(struct icmp_packet));
 294
 295         spin_lock_irqsave(&socket_client->lock, flags);
 296
 297         /* while waiting for the lock the socket_client could have been
 298          * deleted */
 299         if (!socket_client_hash[icmp_packet->uid]) {
 300                 spin_unlock_irqrestore(&socket_client->lock, flags);
 301                 kfree(socket_packet);
 302                 return;
 303         }
 304
 305         list_add_tail(&socket_packet->list, &socket_client->queue_list);
 306         socket_client->queue_len++;
 307
 308         if (socket_client->queue_len > 100) {
 309                 socket_packet = list_first_entry(&socket_client->queue_list,
 310                                                  struct socket_packet, list);
 311
 312                 list_del(&socket_packet->list);
 313                 kfree(socket_packet);
 314                 socket_client->queue_len--;
 315         }
 316
 317         spin_unlock_irqrestore(&socket_client->lock, flags);
 318
 319         wake_up(&socket_client->queue_wait);
 320 }
 321
 322 void bat_socket_receive_packet(struct icmp_packet *icmp_packet)
 323 {
 324         struct socket_client *hash = socket_client_hash[icmp_packet->uid];
 325
 326         if (hash)
 327                 bat_socket_add_packet(hash, icmp_packet);
 328 }