linux/net/batman-adv/icmp_socket.c
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   1/* Copyright (C) 2007-2012 B.A.T.M.A.N. contributors:
   2 *
   3 * Marek Lindner
   4 *
   5 * This program is free software; you can redistribute it and/or
   6 * modify it under the terms of version 2 of the GNU General Public
   7 * License as published by the Free Software Foundation.
   8 *
   9 * This program is distributed in the hope that it will be useful, but
  10 * WITHOUT ANY WARRANTY; without even the implied warranty of
  11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  12 * General Public License for more details.
  13 *
  14 * You should have received a copy of the GNU General Public License
  15 * along with this program; if not, write to the Free Software
  16 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  17 * 02110-1301, USA
  18 */
  19
  20#include "main.h"
  21#include <linux/debugfs.h>
  22#include <linux/slab.h>
  23#include "icmp_socket.h"
  24#include "send.h"
  25#include "hash.h"
  26#include "originator.h"
  27#include "hard-interface.h"
  28
  29static struct batadv_socket_client *batadv_socket_client_hash[256];
  30
  31static void batadv_socket_add_packet(struct batadv_socket_client *socket_client,
  32                                     struct batadv_icmp_packet_rr *icmp_packet,
  33                                     size_t icmp_len);
  34
  35void batadv_socket_init(void)
  36{
  37        memset(batadv_socket_client_hash, 0, sizeof(batadv_socket_client_hash));
  38}
  39
  40static int batadv_socket_open(struct inode *inode, struct file *file)
  41{
  42        unsigned int i;
  43        struct batadv_socket_client *socket_client;
  44
  45        nonseekable_open(inode, file);
  46
  47        socket_client = kmalloc(sizeof(*socket_client), GFP_KERNEL);
  48
  49        if (!socket_client)
  50                return -ENOMEM;
  51
  52        for (i = 0; i < ARRAY_SIZE(batadv_socket_client_hash); i++) {
  53                if (!batadv_socket_client_hash[i]) {
  54                        batadv_socket_client_hash[i] = socket_client;
  55                        break;
  56                }
  57        }
  58
  59        if (i == ARRAY_SIZE(batadv_socket_client_hash)) {
  60                pr_err("Error - can't add another packet client: maximum number of clients reached\n");
  61                kfree(socket_client);
  62                return -EXFULL;
  63        }
  64
  65        INIT_LIST_HEAD(&socket_client->queue_list);
  66        socket_client->queue_len = 0;
  67        socket_client->index = i;
  68        socket_client->bat_priv = inode->i_private;
  69        spin_lock_init(&socket_client->lock);
  70        init_waitqueue_head(&socket_client->queue_wait);
  71
  72        file->private_data = socket_client;
  73
  74        batadv_inc_module_count();
  75        return 0;
  76}
  77
  78static int batadv_socket_release(struct inode *inode, struct file *file)
  79{
  80        struct batadv_socket_client *socket_client = file->private_data;
  81        struct batadv_socket_packet *socket_packet;
  82        struct list_head *list_pos, *list_pos_tmp;
  83
  84        spin_lock_bh(&socket_client->lock);
  85
  86        /* for all packets in the queue ... */
  87        list_for_each_safe(list_pos, list_pos_tmp, &socket_client->queue_list) {
  88                socket_packet = list_entry(list_pos,
  89                                           struct batadv_socket_packet, list);
  90
  91                list_del(list_pos);
  92                kfree(socket_packet);
  93        }
  94
  95        batadv_socket_client_hash[socket_client->index] = NULL;
  96        spin_unlock_bh(&socket_client->lock);
  97
  98        kfree(socket_client);
  99        batadv_dec_module_count();
 100
 101        return 0;
 102}
 103
 104static ssize_t batadv_socket_read(struct file *file, char __user *buf,
 105                                  size_t count, loff_t *ppos)
 106{
 107        struct batadv_socket_client *socket_client = file->private_data;
 108        struct batadv_socket_packet *socket_packet;
 109        size_t packet_len;
 110        int error;
 111
 112        if ((file->f_flags & O_NONBLOCK) && (socket_client->queue_len == 0))
 113                return -EAGAIN;
 114
 115        if ((!buf) || (count < sizeof(struct batadv_icmp_packet)))
 116                return -EINVAL;
 117
 118        if (!access_ok(VERIFY_WRITE, buf, count))
 119                return -EFAULT;
 120
 121        error = wait_event_interruptible(socket_client->queue_wait,
 122                                         socket_client->queue_len);
 123
 124        if (error)
 125                return error;
 126
 127        spin_lock_bh(&socket_client->lock);
 128
 129        socket_packet = list_first_entry(&socket_client->queue_list,
 130                                         struct batadv_socket_packet, list);
 131        list_del(&socket_packet->list);
 132        socket_client->queue_len--;
 133
 134        spin_unlock_bh(&socket_client->lock);
 135
 136        packet_len = min(count, socket_packet->icmp_len);
 137        error = copy_to_user(buf, &socket_packet->icmp_packet, packet_len);
 138
 139        kfree(socket_packet);
 140
 141        if (error)
 142                return -EFAULT;
 143
 144        return packet_len;
 145}
 146
 147static ssize_t batadv_socket_write(struct file *file, const char __user *buff,
 148                                   size_t len, loff_t *off)
 149{
 150        struct batadv_socket_client *socket_client = file->private_data;
 151        struct batadv_priv *bat_priv = socket_client->bat_priv;
 152        struct batadv_hard_iface *primary_if = NULL;
 153        struct sk_buff *skb;
 154        struct batadv_icmp_packet_rr *icmp_packet;
 155
 156        struct batadv_orig_node *orig_node = NULL;
 157        struct batadv_neigh_node *neigh_node = NULL;
 158        size_t packet_len = sizeof(struct batadv_icmp_packet);
 159
 160        if (len < sizeof(struct batadv_icmp_packet)) {
 161                batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 162                           "Error - can't send packet from char device: invalid packet size\n");
 163                return -EINVAL;
 164        }
 165
 166        primary_if = batadv_primary_if_get_selected(bat_priv);
 167
 168        if (!primary_if) {
 169                len = -EFAULT;
 170                goto out;
 171        }
 172
 173        if (len >= sizeof(struct batadv_icmp_packet_rr))
 174                packet_len = sizeof(struct batadv_icmp_packet_rr);
 175
 176        skb = dev_alloc_skb(packet_len + ETH_HLEN);
 177        if (!skb) {
 178                len = -ENOMEM;
 179                goto out;
 180        }
 181
 182        skb_reserve(skb, ETH_HLEN);
 183        icmp_packet = (struct batadv_icmp_packet_rr *)skb_put(skb, packet_len);
 184
 185        if (copy_from_user(icmp_packet, buff, packet_len)) {
 186                len = -EFAULT;
 187                goto free_skb;
 188        }
 189
 190        if (icmp_packet->header.packet_type != BATADV_ICMP) {
 191                batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 192                           "Error - can't send packet from char device: got bogus packet type (expected: BAT_ICMP)\n");
 193                len = -EINVAL;
 194                goto free_skb;
 195        }
 196
 197        if (icmp_packet->msg_type != BATADV_ECHO_REQUEST) {
 198                batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 199                           "Error - can't send packet from char device: got bogus message type (expected: ECHO_REQUEST)\n");
 200                len = -EINVAL;
 201                goto free_skb;
 202        }
 203
 204        icmp_packet->uid = socket_client->index;
 205
 206        if (icmp_packet->header.version != BATADV_COMPAT_VERSION) {
 207                icmp_packet->msg_type = BATADV_PARAMETER_PROBLEM;
 208                icmp_packet->header.version = BATADV_COMPAT_VERSION;
 209                batadv_socket_add_packet(socket_client, icmp_packet,
 210                                         packet_len);
 211                goto free_skb;
 212        }
 213
 214        if (atomic_read(&bat_priv->mesh_state) != BATADV_MESH_ACTIVE)
 215                goto dst_unreach;
 216
 217        orig_node = batadv_orig_hash_find(bat_priv, icmp_packet->dst);
 218        if (!orig_node)
 219                goto dst_unreach;
 220
 221        neigh_node = batadv_orig_node_get_router(orig_node);
 222        if (!neigh_node)
 223                goto dst_unreach;
 224
 225        if (!neigh_node->if_incoming)
 226                goto dst_unreach;
 227
 228        if (neigh_node->if_incoming->if_status != BATADV_IF_ACTIVE)
 229                goto dst_unreach;
 230
 231        memcpy(icmp_packet->orig,
 232               primary_if->net_dev->dev_addr, ETH_ALEN);
 233
 234        if (packet_len == sizeof(struct batadv_icmp_packet_rr))
 235                memcpy(icmp_packet->rr,
 236                       neigh_node->if_incoming->net_dev->dev_addr, ETH_ALEN);
 237
 238        batadv_send_skb_packet(skb, neigh_node->if_incoming, neigh_node->addr);
 239        goto out;
 240
 241dst_unreach:
 242        icmp_packet->msg_type = BATADV_DESTINATION_UNREACHABLE;
 243        batadv_socket_add_packet(socket_client, icmp_packet, packet_len);
 244free_skb:
 245        kfree_skb(skb);
 246out:
 247        if (primary_if)
 248                batadv_hardif_free_ref(primary_if);
 249        if (neigh_node)
 250                batadv_neigh_node_free_ref(neigh_node);
 251        if (orig_node)
 252                batadv_orig_node_free_ref(orig_node);
 253        return len;
 254}
 255
 256static unsigned int batadv_socket_poll(struct file *file, poll_table *wait)
 257{
 258        struct batadv_socket_client *socket_client = file->private_data;
 259
 260        poll_wait(file, &socket_client->queue_wait, wait);
 261
 262        if (socket_client->queue_len > 0)
 263                return POLLIN | POLLRDNORM;
 264
 265        return 0;
 266}
 267
 268static const struct file_operations batadv_fops = {
 269        .owner = THIS_MODULE,
 270        .open = batadv_socket_open,
 271        .release = batadv_socket_release,
 272        .read = batadv_socket_read,
 273        .write = batadv_socket_write,
 274        .poll = batadv_socket_poll,
 275        .llseek = no_llseek,
 276};
 277
 278int batadv_socket_setup(struct batadv_priv *bat_priv)
 279{
 280        struct dentry *d;
 281
 282        if (!bat_priv->debug_dir)
 283                goto err;
 284
 285        d = debugfs_create_file(BATADV_ICMP_SOCKET, S_IFREG | S_IWUSR | S_IRUSR,
 286                                bat_priv->debug_dir, bat_priv, &batadv_fops);
 287        if (!d)
 288                goto err;
 289
 290        return 0;
 291
 292err:
 293        return -ENOMEM;
 294}
 295
 296static void batadv_socket_add_packet(struct batadv_socket_client *socket_client,
 297                                     struct batadv_icmp_packet_rr *icmp_packet,
 298                                     size_t icmp_len)
 299{
 300        struct batadv_socket_packet *socket_packet;
 301
 302        socket_packet = kmalloc(sizeof(*socket_packet), GFP_ATOMIC);
 303
 304        if (!socket_packet)
 305                return;
 306
 307        INIT_LIST_HEAD(&socket_packet->list);
 308        memcpy(&socket_packet->icmp_packet, icmp_packet, icmp_len);
 309        socket_packet->icmp_len = icmp_len;
 310
 311        spin_lock_bh(&socket_client->lock);
 312
 313        /* while waiting for the lock the socket_client could have been
 314         * deleted
 315         */
 316        if (!batadv_socket_client_hash[icmp_packet->uid]) {
 317                spin_unlock_bh(&socket_client->lock);
 318                kfree(socket_packet);
 319                return;
 320        }
 321
 322        list_add_tail(&socket_packet->list, &socket_client->queue_list);
 323        socket_client->queue_len++;
 324
 325        if (socket_client->queue_len > 100) {
 326                socket_packet = list_first_entry(&socket_client->queue_list,
 327                                                 struct batadv_socket_packet,
 328                                                 list);
 329
 330                list_del(&socket_packet->list);
 331                kfree(socket_packet);
 332                socket_client->queue_len--;
 333        }
 334
 335        spin_unlock_bh(&socket_client->lock);
 336
 337        wake_up(&socket_client->queue_wait);
 338}
 339
 340void batadv_socket_receive_packet(struct batadv_icmp_packet_rr *icmp_packet,
 341                                  size_t icmp_len)
 342{
 343        struct batadv_socket_client *hash;
 344
 345        hash = batadv_socket_client_hash[icmp_packet->uid];
 346        if (hash)
 347                batadv_socket_add_packet(hash, icmp_packet, icmp_len);
 348}
 349
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