drivers/net/wireless/mac80211_hwsim.c

   1 /*
   2  * mac80211_hwsim - software simulator of 802.11 radio(s) for mac80211
   3  * Copyright (c) 2008, Jouni Malinen <j@w1.fi>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License version 2 as
   7  * published by the Free Software Foundation.
   8  */
   9
  10 /*
  11  * TODO:
  12  * - IBSS mode simulation (Beacon transmission with competition for "air time")
  13  * - IEEE 802.11a and 802.11n modes
  14  * - RX filtering based on filter configuration (data->rx_filter)
  15  */
  16
  17 #include <net/mac80211.h>
  18 #include <net/ieee80211_radiotap.h>
  19 #include <linux/if_arp.h>
  20 #include <linux/rtnetlink.h>
  21 #include <linux/etherdevice.h>
  22
  23 MODULE_AUTHOR("Jouni Malinen");
  24 MODULE_DESCRIPTION("Software simulator of 802.11 radio(s) for mac80211");
  25 MODULE_LICENSE("GPL");
  26
  27 static int radios = 2;
  28 module_param(radios, int, 0444);
  29 MODULE_PARM_DESC(radios, "Number of simulated radios");
  30
  31
  32 static struct class *hwsim_class;
  33
  34 static struct ieee80211_hw **hwsim_radios;
  35 static int hwsim_radio_count;
  36 static struct net_device *hwsim_mon; /* global monitor netdev */
  37
  38
  39 static const struct ieee80211_channel hwsim_channels[] = {
  40         { .center_freq = 2412 },
  41         { .center_freq = 2417 },
  42         { .center_freq = 2422 },
  43         { .center_freq = 2427 },
  44         { .center_freq = 2432 },
  45         { .center_freq = 2437 },
  46         { .center_freq = 2442 },
  47         { .center_freq = 2447 },
  48         { .center_freq = 2452 },
  49         { .center_freq = 2457 },
  50         { .center_freq = 2462 },
  51         { .center_freq = 2467 },
  52         { .center_freq = 2472 },
  53         { .center_freq = 2484 },
  54 };
  55
  56 static const struct ieee80211_rate hwsim_rates[] = {
  57         { .bitrate = 10 },
  58         { .bitrate = 20, .flags = IEEE80211_RATE_SHORT_PREAMBLE },
  59         { .bitrate = 55, .flags = IEEE80211_RATE_SHORT_PREAMBLE },
  60         { .bitrate = 110, .flags = IEEE80211_RATE_SHORT_PREAMBLE },
  61         { .bitrate = 60 },
  62         { .bitrate = 90 },
  63         { .bitrate = 120 },
  64         { .bitrate = 180 },
  65         { .bitrate = 240 },
  66         { .bitrate = 360 },
  67         { .bitrate = 480 },
  68         { .bitrate = 540 }
  69 };
  70
  71 struct mac80211_hwsim_data {
  72         struct device *dev;
  73         struct ieee80211_supported_band band;
  74         struct ieee80211_channel channels[ARRAY_SIZE(hwsim_channels)];
  75         struct ieee80211_rate rates[ARRAY_SIZE(hwsim_rates)];
  76
  77         struct ieee80211_channel *channel;
  78         int radio_enabled;
  79         unsigned long beacon_int; /* in jiffies unit */
  80         unsigned int rx_filter;
  81         int started;
  82         struct timer_list beacon_timer;
  83 };
  84
  85
  86 struct hwsim_radiotap_hdr {
  87         struct ieee80211_radiotap_header hdr;
  88         u8 rt_flags;
  89         u8 rt_rate;
  90         __le16 rt_channel;
  91         __le16 rt_chbitmask;
  92 } __attribute__ ((packed));
  93
  94
  95 static int hwsim_mon_xmit(struct sk_buff *skb, struct net_device *dev)
  96 {
  97         /* TODO: allow packet injection */
  98         dev_kfree_skb(skb);
  99         return 0;
 100 }
 101
 102
 103 static void mac80211_hwsim_monitor_rx(struct ieee80211_hw *hw,
 104                                       struct sk_buff *tx_skb)
 105 {
 106         struct mac80211_hwsim_data *data = hw->priv;
 107         struct sk_buff *skb;
 108         struct hwsim_radiotap_hdr *hdr;
 109         u16 flags;
 110         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx_skb);
 111         struct ieee80211_rate *txrate = ieee80211_get_tx_rate(hw, info);
 112
 113         if (!netif_running(hwsim_mon))
 114                 return;
 115
 116         skb = skb_copy_expand(tx_skb, sizeof(*hdr), 0, GFP_ATOMIC);
 117         if (skb == NULL)
 118                 return;
 119
 120         hdr = (struct hwsim_radiotap_hdr *) skb_push(skb, sizeof(*hdr));
 121         hdr->hdr.it_version = PKTHDR_RADIOTAP_VERSION;
 122         hdr->hdr.it_pad = 0;
 123         hdr->hdr.it_len = cpu_to_le16(sizeof(*hdr));
 124         hdr->hdr.it_present = cpu_to_le32((1 << IEEE80211_RADIOTAP_FLAGS) |
 125                                           (1 << IEEE80211_RADIOTAP_RATE) |
 126                                           (1 << IEEE80211_RADIOTAP_CHANNEL));
 127         hdr->rt_flags = 0;
 128         hdr->rt_rate = txrate->bitrate / 5;
 129         hdr->rt_channel = cpu_to_le16(data->channel->center_freq);
 130         flags = IEEE80211_CHAN_2GHZ;
 131         if (txrate->flags & IEEE80211_RATE_ERP_G)
 132                 flags |= IEEE80211_CHAN_OFDM;
 133         else
 134                 flags |= IEEE80211_CHAN_CCK;
 135         hdr->rt_chbitmask = cpu_to_le16(flags);
 136
 137         skb->dev = hwsim_mon;
 138         skb_set_mac_header(skb, 0);
 139         skb->ip_summed = CHECKSUM_UNNECESSARY;
 140         skb->pkt_type = PACKET_OTHERHOST;
 141         skb->protocol = htons(ETH_P_802_2);
 142         memset(skb->cb, 0, sizeof(skb->cb));
 143         netif_rx(skb);
 144 }
 145
 146
 147 static int mac80211_hwsim_tx_frame(struct ieee80211_hw *hw,
 148                                    struct sk_buff *skb)
 149 {
 150         struct mac80211_hwsim_data *data = hw->priv;
 151         int i, ack = 0;
 152         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 153         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 154         struct ieee80211_rx_status rx_status;
 155
 156         memset(&rx_status, 0, sizeof(rx_status));
 157         /* TODO: set mactime */
 158         rx_status.freq = data->channel->center_freq;
 159         rx_status.band = data->channel->band;
 160         rx_status.rate_idx = info->tx_rate_idx;
 161         /* TODO: simulate signal strength (and optional packet drop) */
 162
 163         /* Copy skb to all enabled radios that are on the current frequency */
 164         for (i = 0; i < hwsim_radio_count; i++) {
 165                 struct mac80211_hwsim_data *data2;
 166                 struct sk_buff *nskb;
 167
 168                 if (hwsim_radios[i] == NULL || hwsim_radios[i] == hw)
 169                         continue;
 170                 data2 = hwsim_radios[i]->priv;
 171                 if (!data2->started || !data2->radio_enabled ||
 172                     data->channel->center_freq != data2->channel->center_freq)
 173                         continue;
 174
 175                 nskb = skb_copy(skb, GFP_ATOMIC);
 176                 if (nskb == NULL)
 177                         continue;
 178
 179                 if (memcmp(hdr->addr1, hwsim_radios[i]->wiphy->perm_addr,
 180                            ETH_ALEN) == 0)
 181                         ack = 1;
 182                 ieee80211_rx_irqsafe(hwsim_radios[i], nskb, &rx_status);
 183         }
 184
 185         return ack;
 186 }
 187
 188
 189 static int mac80211_hwsim_tx(struct ieee80211_hw *hw, struct sk_buff *skb)
 190 {
 191         struct mac80211_hwsim_data *data = hw->priv;
 192         int ack;
 193         struct ieee80211_tx_info *txi;
 194
 195         mac80211_hwsim_monitor_rx(hw, skb);
 196
 197         if (skb->len < 10) {
 198                 /* Should not happen; just a sanity check for addr1 use */
 199                 dev_kfree_skb(skb);
 200                 return NETDEV_TX_OK;
 201         }
 202
 203         if (!data->radio_enabled) {
 204                 printk(KERN_DEBUG "%s: dropped TX frame since radio "
 205                        "disabled\n", wiphy_name(hw->wiphy));
 206                 dev_kfree_skb(skb);
 207                 return NETDEV_TX_OK;
 208         }
 209
 210         ack = mac80211_hwsim_tx_frame(hw, skb);
 211
 212         txi = IEEE80211_SKB_CB(skb);
 213         memset(&txi->status, 0, sizeof(txi->status));
 214         if (!(txi->flags & IEEE80211_TX_CTL_NO_ACK)) {
 215                 if (ack)
 216                         txi->flags |= IEEE80211_TX_STAT_ACK;
 217                 else
 218                         txi->status.excessive_retries = 1;
 219         }
 220         ieee80211_tx_status_irqsafe(hw, skb);
 221         return NETDEV_TX_OK;
 222 }
 223
 224
 225 static int mac80211_hwsim_start(struct ieee80211_hw *hw)
 226 {
 227         struct mac80211_hwsim_data *data = hw->priv;
 228         printk(KERN_DEBUG "%s:%s\n", wiphy_name(hw->wiphy), __func__);
 229         data->started = 1;
 230         return 0;
 231 }
 232
 233
 234 static void mac80211_hwsim_stop(struct ieee80211_hw *hw)
 235 {
 236         struct mac80211_hwsim_data *data = hw->priv;
 237         data->started = 0;
 238         printk(KERN_DEBUG "%s:%s\n", wiphy_name(hw->wiphy), __func__);
 239 }
 240
 241
 242 static int mac80211_hwsim_add_interface(struct ieee80211_hw *hw,
 243                                         struct ieee80211_if_init_conf *conf)
 244 {
 245         DECLARE_MAC_BUF(mac);
 246         printk(KERN_DEBUG "%s:%s (type=%d mac_addr=%s)\n",
 247                wiphy_name(hw->wiphy), __func__, conf->type,
 248                print_mac(mac, conf->mac_addr));
 249         return 0;
 250 }
 251
 252
 253 static void mac80211_hwsim_remove_interface(
 254         struct ieee80211_hw *hw, struct ieee80211_if_init_conf *conf)
 255 {
 256         DECLARE_MAC_BUF(mac);
 257         printk(KERN_DEBUG "%s:%s (type=%d mac_addr=%s)\n",
 258                wiphy_name(hw->wiphy), __func__, conf->type,
 259                print_mac(mac, conf->mac_addr));
 260 }
 261
 262
 263 static void mac80211_hwsim_beacon_tx(void *arg, u8 *mac,
 264                                      struct ieee80211_vif *vif)
 265 {
 266         struct ieee80211_hw *hw = arg;
 267         struct sk_buff *skb;
 268         struct ieee80211_tx_info *info;
 269
 270         if (vif->type != IEEE80211_IF_TYPE_AP)
 271                 return;
 272
 273         skb = ieee80211_beacon_get(hw, vif);
 274         if (skb == NULL)
 275                 return;
 276         info = IEEE80211_SKB_CB(skb);
 277
 278         mac80211_hwsim_monitor_rx(hw, skb);
 279         mac80211_hwsim_tx_frame(hw, skb);
 280         dev_kfree_skb(skb);
 281 }
 282
 283
 284 static void mac80211_hwsim_beacon(unsigned long arg)
 285 {
 286         struct ieee80211_hw *hw = (struct ieee80211_hw *) arg;
 287         struct mac80211_hwsim_data *data = hw->priv;
 288
 289         if (!data->started || !data->radio_enabled)
 290                 return;
 291
 292         ieee80211_iterate_active_interfaces_atomic(
 293                 hw, mac80211_hwsim_beacon_tx, hw);
 294
 295         data->beacon_timer.expires = jiffies + data->beacon_int;
 296         add_timer(&data->beacon_timer);
 297 }
 298
 299
 300 static int mac80211_hwsim_config(struct ieee80211_hw *hw,
 301                                  struct ieee80211_conf *conf)
 302 {
 303         struct mac80211_hwsim_data *data = hw->priv;
 304
 305         printk(KERN_DEBUG "%s:%s (freq=%d radio_enabled=%d beacon_int=%d)\n",
 306                wiphy_name(hw->wiphy), __func__,
 307                conf->channel->center_freq, conf->radio_enabled,
 308                conf->beacon_int);
 309
 310         data->channel = conf->channel;
 311         data->radio_enabled = conf->radio_enabled;
 312         data->beacon_int = 1024 * conf->beacon_int / 1000 * HZ / 1000;
 313         if (data->beacon_int < 1)
 314                 data->beacon_int = 1;
 315
 316         if (!data->started || !data->radio_enabled)
 317                 del_timer(&data->beacon_timer);
 318         else
 319                 mod_timer(&data->beacon_timer, jiffies + data->beacon_int);
 320
 321         return 0;
 322 }
 323
 324
 325 static void mac80211_hwsim_configure_filter(struct ieee80211_hw *hw,
 326                                             unsigned int changed_flags,
 327                                             unsigned int *total_flags,
 328                                             int mc_count,
 329                                             struct dev_addr_list *mc_list)
 330 {
 331         struct mac80211_hwsim_data *data = hw->priv;
 332
 333         printk(KERN_DEBUG "%s:%s\n", wiphy_name(hw->wiphy), __func__);
 334
 335         data->rx_filter = 0;
 336         if (*total_flags & FIF_PROMISC_IN_BSS)
 337                 data->rx_filter |= FIF_PROMISC_IN_BSS;
 338         if (*total_flags & FIF_ALLMULTI)
 339                 data->rx_filter |= FIF_ALLMULTI;
 340
 341         *total_flags = data->rx_filter;
 342 }
 343
 344
 345
 346 static const struct ieee80211_ops mac80211_hwsim_ops =
 347 {
 348         .tx = mac80211_hwsim_tx,
 349         .start = mac80211_hwsim_start,
 350         .stop = mac80211_hwsim_stop,
 351         .add_interface = mac80211_hwsim_add_interface,
 352         .remove_interface = mac80211_hwsim_remove_interface,
 353         .config = mac80211_hwsim_config,
 354         .configure_filter = mac80211_hwsim_configure_filter,
 355 };
 356
 357
 358 static void mac80211_hwsim_free(void)
 359 {
 360         int i;
 361
 362         for (i = 0; i < hwsim_radio_count; i++) {
 363                 if (hwsim_radios[i]) {
 364                         struct mac80211_hwsim_data *data;
 365                         data = hwsim_radios[i]->priv;
 366                         ieee80211_unregister_hw(hwsim_radios[i]);
 367                         device_unregister(data->dev);
 368                         ieee80211_free_hw(hwsim_radios[i]);
 369                 }
 370         }
 371         kfree(hwsim_radios);
 372         class_destroy(hwsim_class);
 373 }
 374
 375
 376 static struct device_driver mac80211_hwsim_driver = {
 377         .name = "mac80211_hwsim"
 378 };
 379
 380
 381 static void hwsim_mon_setup(struct net_device *dev)
 382 {
 383         dev->hard_start_xmit = hwsim_mon_xmit;
 384         dev->destructor = free_netdev;
 385         ether_setup(dev);
 386         dev->tx_queue_len = 0;
 387         dev->type = ARPHRD_IEEE80211_RADIOTAP;
 388         memset(dev->dev_addr, 0, ETH_ALEN);
 389         dev->dev_addr[0] = 0x12;
 390 }
 391
 392
 393 static int __init init_mac80211_hwsim(void)
 394 {
 395         int i, err = 0;
 396         u8 addr[ETH_ALEN];
 397         struct mac80211_hwsim_data *data;
 398         struct ieee80211_hw *hw;
 399         DECLARE_MAC_BUF(mac);
 400
 401         if (radios < 1 || radios > 65535)
 402                 return -EINVAL;
 403
 404         hwsim_radio_count = radios;
 405         hwsim_radios = kcalloc(hwsim_radio_count,
 406                                sizeof(struct ieee80211_hw *), GFP_KERNEL);
 407         if (hwsim_radios == NULL)
 408                 return -ENOMEM;
 409
 410         hwsim_class = class_create(THIS_MODULE, "mac80211_hwsim");
 411         if (IS_ERR(hwsim_class)) {
 412                 kfree(hwsim_radios);
 413                 return PTR_ERR(hwsim_class);
 414         }
 415
 416         memset(addr, 0, ETH_ALEN);
 417         addr[0] = 0x02;
 418
 419         for (i = 0; i < hwsim_radio_count; i++) {
 420                 printk(KERN_DEBUG "mac80211_hwsim: Initializing radio %d\n",
 421                        i);
 422                 hw = ieee80211_alloc_hw(sizeof(*data), &mac80211_hwsim_ops);
 423                 if (hw == NULL) {
 424                         printk(KERN_DEBUG "mac80211_hwsim: ieee80211_alloc_hw "
 425                                "failed\n");
 426                         err = -ENOMEM;
 427                         goto failed;
 428                 }
 429                 hwsim_radios[i] = hw;
 430
 431                 data = hw->priv;
 432                 data->dev = device_create_drvdata(hwsim_class, NULL, 0, hw,
 433                                                 "hwsim%d", i);
 434                 if (IS_ERR(data->dev)) {
 435                         printk(KERN_DEBUG
 436                                "mac80211_hwsim: device_create_drvdata "
 437                                "failed (%ld)\n", PTR_ERR(data->dev));
 438                         err = -ENOMEM;
 439                         goto failed_drvdata;
 440                 }
 441                 data->dev->driver = &mac80211_hwsim_driver;
 442
 443                 SET_IEEE80211_DEV(hw, data->dev);
 444                 addr[3] = i >> 8;
 445                 addr[4] = i;
 446                 SET_IEEE80211_PERM_ADDR(hw, addr);
 447
 448                 hw->channel_change_time = 1;
 449                 hw->queues = 1;
 450
 451                 memcpy(data->channels, hwsim_channels, sizeof(hwsim_channels));
 452                 memcpy(data->rates, hwsim_rates, sizeof(hwsim_rates));
 453                 data->band.channels = data->channels;
 454                 data->band.n_channels = ARRAY_SIZE(hwsim_channels);
 455                 data->band.bitrates = data->rates;
 456                 data->band.n_bitrates = ARRAY_SIZE(hwsim_rates);
 457                 hw->wiphy->bands[IEEE80211_BAND_2GHZ] = &data->band;
 458
 459                 err = ieee80211_register_hw(hw);
 460                 if (err < 0) {
 461                         printk(KERN_DEBUG "mac80211_hwsim: "
 462                                "ieee80211_register_hw failed (%d)\n", err);
 463                         goto failed_hw;
 464                 }
 465
 466                 printk(KERN_DEBUG "%s: hwaddr %s registered\n",
 467                        wiphy_name(hw->wiphy),
 468                        print_mac(mac, hw->wiphy->perm_addr));
 469
 470                 setup_timer(&data->beacon_timer, mac80211_hwsim_beacon,
 471                             (unsigned long) hw);
 472         }
 473
 474         hwsim_mon = alloc_netdev(0, "hwsim%d", hwsim_mon_setup);
 475         if (hwsim_mon == NULL)
 476                 goto failed;
 477
 478         rtnl_lock();
 479
 480         err = dev_alloc_name(hwsim_mon, hwsim_mon->name);
 481         if (err < 0)
 482                 goto failed_mon;
 483
 484
 485         err = register_netdevice(hwsim_mon);
 486         if (err < 0)
 487                 goto failed_mon;
 488
 489         rtnl_unlock();
 490
 491         return 0;
 492
 493 failed_mon:
 494         rtnl_unlock();
 495         free_netdev(hwsim_mon);
 496         mac80211_hwsim_free();
 497         return err;
 498
 499 failed_hw:
 500         device_unregister(data->dev);
 501 failed_drvdata:
 502         ieee80211_free_hw(hw);
 503         hwsim_radios[i] = NULL;
 504 failed:
 505         mac80211_hwsim_free();
 506         return err;
 507 }
 508
 509
 510 static void __exit exit_mac80211_hwsim(void)
 511 {
 512         printk(KERN_DEBUG "mac80211_hwsim: unregister %d radios\n",
 513                hwsim_radio_count);
 514
 515         unregister_netdev(hwsim_mon);
 516         mac80211_hwsim_free();
 517 }
 518
 519
 520 module_init(init_mac80211_hwsim);
 521 module_exit(exit_mac80211_hwsim);