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 = __constant_cpu_to_le32(
 125              (1 << IEEE80211_RADIOTAP_FLAGS) |
 126              (1 << IEEE80211_RADIOTAP_RATE) |
 127              (1 << IEEE80211_RADIOTAP_CHANNEL));
 128         hdr->rt_flags = 0;
 129         hdr->rt_rate = txrate->bitrate / 5;
 130         hdr->rt_channel = data->channel->center_freq;
 131         flags = IEEE80211_CHAN_2GHZ;
 132         if (txrate->flags & IEEE80211_RATE_ERP_G)
 133                 flags |= IEEE80211_CHAN_OFDM;
 134         else
 135                 flags |= IEEE80211_CHAN_CCK;
 136         hdr->rt_chbitmask = cpu_to_le16(flags);
 137
 138         skb->dev = hwsim_mon;
 139         skb_set_mac_header(skb, 0);
 140         skb->ip_summed = CHECKSUM_UNNECESSARY;
 141         skb->pkt_type = PACKET_OTHERHOST;
 142         skb->protocol = __constant_htons(ETH_P_802_2);
 143         memset(skb->cb, 0, sizeof(skb->cb));
 144         netif_rx(skb);
 145 }
 146
 147
 148 static int mac80211_hwsim_tx(struct ieee80211_hw *hw, struct sk_buff *skb)
 149 {
 150         struct mac80211_hwsim_data *data = hw->priv;
 151         struct ieee80211_rx_status rx_status;
 152         int i, ack = 0;
 153         struct ieee80211_hdr *hdr;
 154         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 155         struct ieee80211_tx_info *txi;
 156
 157         mac80211_hwsim_monitor_rx(hw, skb);
 158
 159         if (skb->len < 10) {
 160                 /* Should not happen; just a sanity check for addr1 use */
 161                 dev_kfree_skb(skb);
 162                 return NETDEV_TX_OK;
 163         }
 164
 165         if (!data->radio_enabled) {
 166                 printk(KERN_DEBUG "%s: dropped TX frame since radio "
 167                        "disabled\n", wiphy_name(hw->wiphy));
 168                 dev_kfree_skb(skb);
 169                 return NETDEV_TX_OK;
 170         }
 171
 172         hdr = (struct ieee80211_hdr *) skb->data;
 173
 174         memset(&rx_status, 0, sizeof(rx_status));
 175         /* TODO: set mactime */
 176         rx_status.freq = data->channel->center_freq;
 177         rx_status.band = data->channel->band;
 178         rx_status.rate_idx = info->tx_rate_idx;
 179         /* TODO: simulate signal strength (and optional packet drop) */
 180
 181         /* Copy skb to all enabled radios that are on the current frequency */
 182         for (i = 0; i < hwsim_radio_count; i++) {
 183                 struct mac80211_hwsim_data *data2;
 184                 struct sk_buff *nskb;
 185
 186                 if (hwsim_radios[i] == NULL || hwsim_radios[i] == hw)
 187                         continue;
 188                 data2 = hwsim_radios[i]->priv;
 189                 if (!data2->started || !data2->radio_enabled ||
 190                     data->channel->center_freq != data2->channel->center_freq)
 191                         continue;
 192
 193                 nskb = skb_copy(skb, GFP_ATOMIC);
 194                 if (nskb == NULL)
 195                         continue;
 196
 197                 if (memcmp(hdr->addr1, hwsim_radios[i]->wiphy->perm_addr,
 198                            ETH_ALEN) == 0)
 199                         ack = 1;
 200                 ieee80211_rx_irqsafe(hwsim_radios[i], nskb, &rx_status);
 201         }
 202
 203         txi = IEEE80211_SKB_CB(skb);
 204         memset(&txi->status, 0, sizeof(txi->status));
 205         if (!(txi->flags & IEEE80211_TX_CTL_NO_ACK)) {
 206                 if (ack)
 207                         txi->flags |= IEEE80211_TX_STAT_ACK;
 208                 else
 209                         txi->status.excessive_retries = 1;
 210         }
 211         ieee80211_tx_status_irqsafe(hw, skb);
 212         return NETDEV_TX_OK;
 213 }
 214
 215
 216 static int mac80211_hwsim_start(struct ieee80211_hw *hw)
 217 {
 218         struct mac80211_hwsim_data *data = hw->priv;
 219         printk(KERN_DEBUG "%s:%s\n", wiphy_name(hw->wiphy), __func__);
 220         data->started = 1;
 221         return 0;
 222 }
 223
 224
 225 static void mac80211_hwsim_stop(struct ieee80211_hw *hw)
 226 {
 227         struct mac80211_hwsim_data *data = hw->priv;
 228         data->started = 0;
 229         printk(KERN_DEBUG "%s:%s\n", wiphy_name(hw->wiphy), __func__);
 230 }
 231
 232
 233 static int mac80211_hwsim_add_interface(struct ieee80211_hw *hw,
 234                                         struct ieee80211_if_init_conf *conf)
 235 {
 236         DECLARE_MAC_BUF(mac);
 237         printk(KERN_DEBUG "%s:%s (type=%d mac_addr=%s)\n",
 238                wiphy_name(hw->wiphy), __func__, conf->type,
 239                print_mac(mac, conf->mac_addr));
 240         return 0;
 241 }
 242
 243
 244 static void mac80211_hwsim_remove_interface(
 245         struct ieee80211_hw *hw, struct ieee80211_if_init_conf *conf)
 246 {
 247         DECLARE_MAC_BUF(mac);
 248         printk(KERN_DEBUG "%s:%s (type=%d mac_addr=%s)\n",
 249                wiphy_name(hw->wiphy), __func__, conf->type,
 250                print_mac(mac, conf->mac_addr));
 251 }
 252
 253
 254 static void mac80211_hwsim_beacon_tx(void *arg, u8 *mac,
 255                                      struct ieee80211_vif *vif)
 256 {
 257         struct ieee80211_hw *hw = arg;
 258         struct mac80211_hwsim_data *data = hw->priv;
 259         struct sk_buff *skb;
 260         struct ieee80211_rx_status rx_status;
 261         int i;
 262         struct ieee80211_tx_info *info;
 263
 264         if (vif->type != IEEE80211_IF_TYPE_AP)
 265                 return;
 266
 267         skb = ieee80211_beacon_get(hw, vif);
 268         if (skb == NULL)
 269                 return;
 270         info = IEEE80211_SKB_CB(skb);
 271
 272         mac80211_hwsim_monitor_rx(hw, skb);
 273
 274         memset(&rx_status, 0, sizeof(rx_status));
 275         /* TODO: set mactime */
 276         rx_status.freq = data->channel->center_freq;
 277         rx_status.band = data->channel->band;
 278         rx_status.rate_idx = info->tx_rate_idx;
 279         /* TODO: simulate signal strength (and optional packet drop) */
 280
 281         /* Copy skb to all enabled radios that are on the current frequency */
 282         for (i = 0; i < hwsim_radio_count; i++) {
 283                 struct mac80211_hwsim_data *data2;
 284                 struct sk_buff *nskb;
 285
 286                 if (hwsim_radios[i] == NULL || hwsim_radios[i] == hw)
 287                         continue;
 288                 data2 = hwsim_radios[i]->priv;
 289                 if (!data2->started || !data2->radio_enabled ||
 290                     data->channel->center_freq != data2->channel->center_freq)
 291                         continue;
 292
 293                 nskb = skb_copy(skb, GFP_ATOMIC);
 294                 if (nskb == NULL)
 295                         continue;
 296
 297                 ieee80211_rx_irqsafe(hwsim_radios[i], nskb, &rx_status);
 298         }
 299
 300         dev_kfree_skb(skb);
 301 }
 302
 303
 304 static void mac80211_hwsim_beacon(unsigned long arg)
 305 {
 306         struct ieee80211_hw *hw = (struct ieee80211_hw *) arg;
 307         struct mac80211_hwsim_data *data = hw->priv;
 308
 309         if (!data->started || !data->radio_enabled)
 310                 return;
 311
 312         ieee80211_iterate_active_interfaces(hw, mac80211_hwsim_beacon_tx, hw);
 313
 314         data->beacon_timer.expires = jiffies + data->beacon_int;
 315         add_timer(&data->beacon_timer);
 316 }
 317
 318
 319 static int mac80211_hwsim_config(struct ieee80211_hw *hw,
 320                                  struct ieee80211_conf *conf)
 321 {
 322         struct mac80211_hwsim_data *data = hw->priv;
 323
 324         printk(KERN_DEBUG "%s:%s (freq=%d radio_enabled=%d beacon_int=%d)\n",
 325                wiphy_name(hw->wiphy), __func__,
 326                conf->channel->center_freq, conf->radio_enabled,
 327                conf->beacon_int);
 328
 329         data->channel = conf->channel;
 330         data->radio_enabled = conf->radio_enabled;
 331         data->beacon_int = 1024 * conf->beacon_int / 1000 * HZ / 1000;
 332         if (data->beacon_int < 1)
 333                 data->beacon_int = 1;
 334
 335         if (!data->started || !data->radio_enabled)
 336                 del_timer(&data->beacon_timer);
 337         else
 338                 mod_timer(&data->beacon_timer, jiffies + data->beacon_int);
 339
 340         return 0;
 341 }
 342
 343
 344 static void mac80211_hwsim_configure_filter(struct ieee80211_hw *hw,
 345                                             unsigned int changed_flags,
 346                                             unsigned int *total_flags,
 347                                             int mc_count,
 348                                             struct dev_addr_list *mc_list)
 349 {
 350         struct mac80211_hwsim_data *data = hw->priv;
 351
 352         printk(KERN_DEBUG "%s:%s\n", wiphy_name(hw->wiphy), __func__);
 353
 354         data->rx_filter = 0;
 355         if (*total_flags & FIF_PROMISC_IN_BSS)
 356                 data->rx_filter |= FIF_PROMISC_IN_BSS;
 357         if (*total_flags & FIF_ALLMULTI)
 358                 data->rx_filter |= FIF_ALLMULTI;
 359
 360         *total_flags = data->rx_filter;
 361 }
 362
 363
 364
 365 static const struct ieee80211_ops mac80211_hwsim_ops =
 366 {
 367         .tx = mac80211_hwsim_tx,
 368         .start = mac80211_hwsim_start,
 369         .stop = mac80211_hwsim_stop,
 370         .add_interface = mac80211_hwsim_add_interface,
 371         .remove_interface = mac80211_hwsim_remove_interface,
 372         .config = mac80211_hwsim_config,
 373         .configure_filter = mac80211_hwsim_configure_filter,
 374 };
 375
 376
 377 static void mac80211_hwsim_free(void)
 378 {
 379         int i;
 380
 381         for (i = 0; i < hwsim_radio_count; i++) {
 382                 if (hwsim_radios[i]) {
 383                         struct mac80211_hwsim_data *data;
 384                         data = hwsim_radios[i]->priv;
 385                         ieee80211_unregister_hw(hwsim_radios[i]);
 386                         if (!IS_ERR(data->dev))
 387                                 device_unregister(data->dev);
 388                         ieee80211_free_hw(hwsim_radios[i]);
 389                 }
 390         }
 391         kfree(hwsim_radios);
 392         class_destroy(hwsim_class);
 393 }
 394
 395
 396 static struct device_driver mac80211_hwsim_driver = {
 397         .name = "mac80211_hwsim"
 398 };
 399
 400
 401 static void hwsim_mon_setup(struct net_device *dev)
 402 {
 403         dev->hard_start_xmit = hwsim_mon_xmit;
 404         dev->destructor = free_netdev;
 405         ether_setup(dev);
 406         dev->tx_queue_len = 0;
 407         dev->type = ARPHRD_IEEE80211_RADIOTAP;
 408         memset(dev->dev_addr, 0, ETH_ALEN);
 409         dev->dev_addr[0] = 0x12;
 410 }
 411
 412
 413 static int __init init_mac80211_hwsim(void)
 414 {
 415         int i, err = 0;
 416         u8 addr[ETH_ALEN];
 417         struct mac80211_hwsim_data *data;
 418         struct ieee80211_hw *hw;
 419         DECLARE_MAC_BUF(mac);
 420
 421         if (radios < 1 || radios > 65535)
 422                 return -EINVAL;
 423
 424         hwsim_radio_count = radios;
 425         hwsim_radios = kcalloc(hwsim_radio_count,
 426                                sizeof(struct ieee80211_hw *), GFP_KERNEL);
 427         if (hwsim_radios == NULL)
 428                 return -ENOMEM;
 429
 430         hwsim_class = class_create(THIS_MODULE, "mac80211_hwsim");
 431         if (IS_ERR(hwsim_class)) {
 432                 kfree(hwsim_radios);
 433                 return PTR_ERR(hwsim_class);
 434         }
 435
 436         memset(addr, 0, ETH_ALEN);
 437         addr[0] = 0x02;
 438
 439         for (i = 0; i < hwsim_radio_count; i++) {
 440                 printk(KERN_DEBUG "mac80211_hwsim: Initializing radio %d\n",
 441                        i);
 442                 hw = ieee80211_alloc_hw(sizeof(*data), &mac80211_hwsim_ops);
 443                 if (hw == NULL) {
 444                         printk(KERN_DEBUG "mac80211_hwsim: ieee80211_alloc_hw "
 445                                "failed\n");
 446                         err = -ENOMEM;
 447                         goto failed;
 448                 }
 449                 hwsim_radios[i] = hw;
 450
 451                 data = hw->priv;
 452                 data->dev = device_create(hwsim_class, NULL, 0, "hwsim%d", i);
 453                 if (IS_ERR(data->dev)) {
 454                         printk(KERN_DEBUG "mac80211_hwsim: device_create "
 455                                "failed (%ld)\n", PTR_ERR(data->dev));
 456                         err = -ENOMEM;
 457                         goto failed;
 458                 }
 459                 data->dev->driver = &mac80211_hwsim_driver;
 460                 dev_set_drvdata(data->dev, hw);
 461
 462                 SET_IEEE80211_DEV(hw, data->dev);
 463                 addr[3] = i >> 8;
 464                 addr[4] = i;
 465                 SET_IEEE80211_PERM_ADDR(hw, addr);
 466
 467                 hw->channel_change_time = 1;
 468                 hw->queues = 1;
 469
 470                 memcpy(data->channels, hwsim_channels, sizeof(hwsim_channels));
 471                 memcpy(data->rates, hwsim_rates, sizeof(hwsim_rates));
 472                 data->band.channels = data->channels;
 473                 data->band.n_channels = ARRAY_SIZE(hwsim_channels);
 474                 data->band.bitrates = data->rates;
 475                 data->band.n_bitrates = ARRAY_SIZE(hwsim_rates);
 476                 hw->wiphy->bands[IEEE80211_BAND_2GHZ] = &data->band;
 477
 478                 err = ieee80211_register_hw(hw);
 479                 if (err < 0) {
 480                         printk(KERN_DEBUG "mac80211_hwsim: "
 481                                "ieee80211_register_hw failed (%d)\n", err);
 482                         goto failed;
 483                 }
 484
 485                 printk(KERN_DEBUG "%s: hwaddr %s registered\n",
 486                        wiphy_name(hw->wiphy),
 487                        print_mac(mac, hw->wiphy->perm_addr));
 488
 489                 setup_timer(&data->beacon_timer, mac80211_hwsim_beacon,
 490                             (unsigned long) hw);
 491         }
 492
 493         hwsim_mon = alloc_netdev(0, "hwsim%d", hwsim_mon_setup);
 494         if (hwsim_mon == NULL)
 495                 goto failed;
 496
 497         rtnl_lock();
 498
 499         err = dev_alloc_name(hwsim_mon, hwsim_mon->name);
 500         if (err < 0) {
 501                 goto failed_mon;
 502         }
 503
 504         err = register_netdevice(hwsim_mon);
 505         if (err < 0)
 506                 goto failed_mon;
 507
 508         rtnl_unlock();
 509
 510         return 0;
 511
 512 failed_mon:
 513         rtnl_unlock();
 514         free_netdev(hwsim_mon);
 515
 516 failed:
 517         mac80211_hwsim_free();
 518         return err;
 519 }
 520
 521
 522 static void __exit exit_mac80211_hwsim(void)
 523 {
 524         printk(KERN_DEBUG "mac80211_hwsim: unregister %d radios\n",
 525                hwsim_radio_count);
 526
 527         unregister_netdev(hwsim_mon);
 528         mac80211_hwsim_free();
 529 }
 530
 531
 532 module_init(init_mac80211_hwsim);
 533 module_exit(exit_mac80211_hwsim);