mac80211_hwsim/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  * - periodic Beacon transmission in AP mode
  13  * - IBSS mode simulation (Beacon transmission with competition for "air time")
  14  * - IEEE 802.11a and 802.11n modes
  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         { .chan = 1, .freq = 2412, .val = 1 },
  41         { .chan = 2, .freq = 2417, .val = 2 },
  42         { .chan = 3, .freq = 2422, .val = 3 },
  43         { .chan = 4, .freq = 2427, .val = 4 },
  44         { .chan = 5, .freq = 2432, .val = 5 },
  45         { .chan = 6, .freq = 2437, .val = 6 },
  46         { .chan = 7, .freq = 2442, .val = 7 },
  47         { .chan = 8, .freq = 2447, .val = 8 },
  48         { .chan = 9, .freq = 2452, .val = 9 },
  49         { .chan = 10, .freq = 2457, .val = 10 },
  50         { .chan = 11, .freq = 2462, .val = 11 },
  51         { .chan = 12, .freq = 2467, .val = 12 },
  52         { .chan = 13, .freq = 2472, .val = 13 },
  53         { .chan = 14, .freq = 2484, .val = 14 },
  54 };
  55
  56 static const struct ieee80211_rate hwsim_rates[] = {
  57         { .rate = 10, .val = 10, .flags = IEEE80211_RATE_CCK },
  58         { .rate = 20, .val = 20, .val2 = 21, .flags = IEEE80211_RATE_CCK_2 },
  59         { .rate = 55, .val = 55, .val2 = 56, .flags = IEEE80211_RATE_CCK_2 },
  60         { .rate = 110, .val = 110, .val2 = 111,
  61           .flags = IEEE80211_RATE_CCK_2 },
  62         { .rate = 60, .val = 60, .flags = IEEE80211_RATE_OFDM },
  63         { .rate = 90, .val = 90, .flags = IEEE80211_RATE_OFDM },
  64         { .rate = 120, .val = 120, .flags = IEEE80211_RATE_OFDM },
  65         { .rate = 180, .val = 180, .flags = IEEE80211_RATE_OFDM },
  66         { .rate = 240, .val = 240, .flags = IEEE80211_RATE_OFDM },
  67         { .rate = 360, .val = 360, .flags = IEEE80211_RATE_OFDM },
  68         { .rate = 480, .val = 480, .flags = IEEE80211_RATE_OFDM },
  69         { .rate = 540, .val = 540, .flags = IEEE80211_RATE_OFDM }
  70 };
  71
  72 struct mac80211_hwsim_data {
  73         struct device *dev;
  74         struct ieee80211_hw_mode modes[1];
  75         struct ieee80211_channel channels[ARRAY_SIZE(hwsim_channels)];
  76         struct ieee80211_rate rates[ARRAY_SIZE(hwsim_rates)];
  77
  78         int freq;
  79         int channel;
  80         enum ieee80211_phymode phymode;
  81         int radio_enabled;
  82         unsigned long beacon_int; /* in jiffies unit */
  83         unsigned int rx_filter;
  84         int started;
  85         struct timer_list beacon_timer;
  86 };
  87
  88
  89 struct hwsim_radiotap_hdr {
  90         struct ieee80211_radiotap_header hdr;
  91         u8 rt_flags;
  92         u8 rt_rate;
  93         __le16 rt_channel;
  94         __le16 rt_chbitmask;
  95 } __attribute__ ((packed));
  96
  97
  98 static int hwsim_mon_xmit(struct sk_buff *skb, struct net_device *dev)
  99 {
 100         /* TODO: allow packet injection */
 101         dev_kfree_skb(skb);
 102         return 0;
 103 }
 104
 105
 106 static void mac80211_hwsim_monitor_rx(struct mac80211_hwsim_data *data,
 107                                       struct sk_buff *tx_skb,
 108                                       struct ieee80211_tx_control *control)
 109 {
 110         struct sk_buff *skb;
 111         struct hwsim_radiotap_hdr *hdr;
 112         u16 flags;
 113
 114         if (!netif_running(hwsim_mon))
 115                 return;
 116
 117         skb = skb_copy_expand(tx_skb, sizeof(*hdr), 0, GFP_ATOMIC);
 118         if (skb == NULL)
 119                 return;
 120
 121         hdr = (struct hwsim_radiotap_hdr *) skb_push(skb, sizeof(*hdr));
 122         hdr->hdr.it_version = PKTHDR_RADIOTAP_VERSION;
 123         hdr->hdr.it_pad = 0;
 124         hdr->hdr.it_len = cpu_to_le16(sizeof(*hdr));
 125         hdr->hdr.it_present = __constant_cpu_to_le32(
 126              (1 << IEEE80211_RADIOTAP_FLAGS) |
 127              (1 << IEEE80211_RADIOTAP_RATE) |
 128              (1 << IEEE80211_RADIOTAP_CHANNEL));
 129         hdr->rt_flags = 0;
 130         hdr->rt_rate = control->tx_rate / 5;
 131         hdr->rt_channel = data->freq;
 132         flags = IEEE80211_CHAN_2GHZ;
 133         if (control->rate->flags & IEEE80211_RATE_OFDM)
 134                 flags |= IEEE80211_CHAN_OFDM;
 135         if (control->rate->flags & IEEE80211_RATE_CCK)
 136                 flags |= IEEE80211_CHAN_CCK;
 137         hdr->rt_chbitmask = cpu_to_le16(flags);
 138
 139         skb->dev = hwsim_mon;
 140         skb_set_mac_header(skb, 0);
 141         skb->ip_summed = CHECKSUM_UNNECESSARY;
 142         skb->pkt_type = PACKET_OTHERHOST;
 143         skb->protocol = __constant_htons(ETH_P_802_2);
 144         memset(skb->cb, 0, sizeof(skb->cb));
 145         netif_rx(skb);
 146 }
 147
 148
 149 static int mac80211_hwsim_tx(struct ieee80211_hw *hw, struct sk_buff *skb,
 150                              struct ieee80211_tx_control *control)
 151 {
 152         struct mac80211_hwsim_data *data = hw->priv;
 153         struct ieee80211_tx_status tx_status;
 154         struct ieee80211_rx_status rx_status;
 155         int i, ack = 0;
 156         struct ieee80211_hdr *hdr;
 157
 158         mac80211_hwsim_monitor_rx(data, skb, control);
 159
 160         if (skb->len < 10) {
 161                 /* Should not happen; just a sanity check for addr1 use */
 162                 dev_kfree_skb(skb);
 163                 return NETDEV_TX_OK;
 164         }
 165
 166         if (!data->radio_enabled) {
 167                 printk(KERN_DEBUG "%s: dropped TX frame since radio "
 168                        "disabled\n", wiphy_name(hw->wiphy));
 169                 dev_kfree_skb(skb);
 170                 return NETDEV_TX_OK;
 171         }
 172
 173         hdr = (struct ieee80211_hdr *) skb->data;
 174         if (is_multicast_ether_addr(hdr->addr1))
 175                 ack = 1;
 176
 177         memset(&rx_status, 0, sizeof(rx_status));
 178         /* TODO: set mactime */
 179         rx_status.freq = data->freq;
 180         rx_status.channel = data->channel;
 181         rx_status.phymode = data->phymode;
 182         rx_status.rate = control->tx_rate;
 183         /* TODO: simulate signal strength (and optional packet drop) */
 184
 185         /* Copy skb to all enabled radios that are on the current frequency */
 186         for (i = 0; i < hwsim_radio_count; i++) {
 187                 struct mac80211_hwsim_data *data2;
 188                 struct sk_buff *nskb;
 189
 190                 if (hwsim_radios[i] == NULL || hwsim_radios[i] == hw)
 191                         continue;
 192                 data2 = hwsim_radios[i]->priv;
 193                 if (!data2->started || !data2->radio_enabled ||
 194                     data->freq != data2->freq)
 195                         continue;
 196
 197                 nskb = skb_copy(skb, GFP_ATOMIC);
 198                 if (nskb == NULL)
 199                         continue;
 200
 201                 if (memcmp(hdr->addr1, hwsim_radios[i]->wiphy->perm_addr,
 202                            ETH_ALEN) == 0)
 203                         ack = 1;
 204                 ieee80211_rx_irqsafe(hwsim_radios[i], nskb, &rx_status);
 205         }
 206
 207         memset(&tx_status, 0, sizeof(tx_status));
 208         memcpy(&tx_status.control, control, sizeof(*control));
 209         tx_status.flags = ack ? IEEE80211_TX_STATUS_ACK : 0;
 210         ieee80211_tx_status_irqsafe(hw, skb, &tx_status);
 211         return NETDEV_TX_OK;
 212 }
 213
 214
 215 static int mac80211_hwsim_start(struct ieee80211_hw *hw)
 216 {
 217         struct mac80211_hwsim_data *data = hw->priv;
 218         printk(KERN_DEBUG "%s:%s\n", wiphy_name(hw->wiphy), __func__);
 219         data->started = 1;
 220         return 0;
 221 }
 222
 223
 224 static void mac80211_hwsim_stop(struct ieee80211_hw *hw)
 225 {
 226         struct mac80211_hwsim_data *data = hw->priv;
 227         data->started = 0;
 228         printk(KERN_DEBUG "%s:%s\n", wiphy_name(hw->wiphy), __func__);
 229 }
 230
 231
 232 static int mac80211_hwsim_add_interface(struct ieee80211_hw *hw,
 233                                         struct ieee80211_if_init_conf *conf)
 234 {
 235         DECLARE_MAC_BUF(mac);
 236         printk(KERN_DEBUG "%s:%s (type=%d mac_addr=%s)\n",
 237                wiphy_name(hw->wiphy), __func__, conf->type,
 238                print_mac(mac, conf->mac_addr));
 239         return 0;
 240 }
 241
 242
 243 static void mac80211_hwsim_remove_interface(
 244         struct ieee80211_hw *hw, struct ieee80211_if_init_conf *conf)
 245 {
 246         DECLARE_MAC_BUF(mac);
 247         printk(KERN_DEBUG "%s:%s (type=%d mac_addr=%s)\n",
 248                wiphy_name(hw->wiphy), __func__, conf->type,
 249                print_mac(mac, conf->mac_addr));
 250 }
 251
 252
 253 static void mac80211_hwsim_beacon_tx(void *arg, u8 *mac,
 254                                      struct ieee80211_vif *vif)
 255 {
 256         struct ieee80211_hw *hw = arg;
 257         struct mac80211_hwsim_data *data = hw->priv;
 258         struct ieee80211_tx_control control;
 259         struct sk_buff *skb;
 260         struct ieee80211_rx_status rx_status;
 261         int i;
 262
 263         if (vif->type != IEEE80211_IF_TYPE_AP)
 264                 return;
 265
 266         skb = ieee80211_beacon_get(hw, vif, &control);
 267         if (skb == NULL)
 268                 return;
 269
 270         mac80211_hwsim_monitor_rx(data, skb, &control);
 271
 272         memset(&rx_status, 0, sizeof(rx_status));
 273         /* TODO: set mactime */
 274         rx_status.freq = data->freq;
 275         rx_status.channel = data->channel;
 276         rx_status.phymode = data->phymode;
 277         rx_status.rate = control.tx_rate;
 278         /* TODO: simulate signal strength (and optional packet drop) */
 279
 280         /* Copy skb to all enabled radios that are on the current frequency */
 281         for (i = 0; i < hwsim_radio_count; i++) {
 282                 struct mac80211_hwsim_data *data2;
 283                 struct sk_buff *nskb;
 284
 285                 if (hwsim_radios[i] == NULL || hwsim_radios[i] == hw)
 286                         continue;
 287                 data2 = hwsim_radios[i]->priv;
 288                 if (!data2->started || !data2->radio_enabled ||
 289                     data->freq != data2->freq)
 290                         continue;
 291
 292                 nskb = skb_copy(skb, GFP_ATOMIC);
 293                 if (nskb == NULL)
 294                         continue;
 295
 296                 ieee80211_rx_irqsafe(hwsim_radios[i], nskb, &rx_status);
 297         }
 298
 299         dev_kfree_skb(skb);
 300 }
 301
 302
 303 static void mac80211_hwsim_beacon(unsigned long arg)
 304 {
 305         struct ieee80211_hw *hw = (struct ieee80211_hw *) arg;
 306         struct mac80211_hwsim_data *data = hw->priv;
 307
 308         if (!data->started || !data->radio_enabled)
 309                 return;
 310
 311         ieee80211_iterate_active_interfaces(hw, mac80211_hwsim_beacon_tx, hw);
 312
 313         data->beacon_timer.expires = jiffies + data->beacon_int;
 314         add_timer(&data->beacon_timer);
 315 }
 316
 317
 318 static int mac80211_hwsim_config(struct ieee80211_hw *hw,
 319                                  struct ieee80211_conf *conf)
 320 {
 321         struct mac80211_hwsim_data *data = hw->priv;
 322
 323         printk(KERN_DEBUG "%s:%s (freq=%d radio_enabled=%d beacon_int=%d)\n",
 324                wiphy_name(hw->wiphy), __func__,
 325                conf->freq, conf->radio_enabled, conf->beacon_int);
 326
 327         data->freq = conf->freq;
 328         data->channel = conf->channel;
 329         data->phymode = conf->phymode;
 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->modes[0].channels = data->channels;
 473                 data->modes[0].rates = data->rates;
 474                 data->modes[0].mode = MODE_IEEE80211G;
 475                 data->modes[0].num_channels = ARRAY_SIZE(hwsim_channels);
 476                 data->modes[0].num_rates = ARRAY_SIZE(hwsim_rates);
 477
 478                 err = ieee80211_register_hwmode(hw, data->modes);
 479                 if (err < 0) {
 480                         printk(KERN_DEBUG "mac80211_hwsim: "
 481                                "ieee80211_register_hwmode failed (%d)\n", err);
 482                         goto failed;
 483                 }
 484
 485                 err = ieee80211_register_hw(hw);
 486                 if (err < 0) {
 487                         printk(KERN_DEBUG "mac80211_hwsim: "
 488                                "ieee80211_register_hw failed (%d)\n", err);
 489                         goto failed;
 490                 }
 491
 492                 printk(KERN_DEBUG "%s: hwaddr %s registered\n",
 493                        wiphy_name(hw->wiphy),
 494                        print_mac(mac, hw->wiphy->perm_addr));
 495
 496                 setup_timer(&data->beacon_timer, mac80211_hwsim_beacon,
 497                             (unsigned long) hw);
 498         }
 499
 500         hwsim_mon = alloc_netdev(0, "hwsim%d", hwsim_mon_setup);
 501         if (hwsim_mon == NULL)
 502                 goto failed;
 503
 504         rtnl_lock();
 505
 506         err = dev_alloc_name(hwsim_mon, hwsim_mon->name);
 507         if (err < 0) {
 508                 goto failed_mon;
 509         }
 510
 511         err = register_netdevice(hwsim_mon);
 512         if (err < 0)
 513                 goto failed_mon;
 514
 515         rtnl_unlock();
 516
 517         return 0;
 518
 519 failed_mon:
 520         rtnl_unlock();
 521         free_netdev(hwsim_mon);
 522
 523 failed:
 524         mac80211_hwsim_free();
 525         return err;
 526 }
 527
 528
 529 static void __exit exit_mac80211_hwsim(void)
 530 {
 531         printk(KERN_DEBUG "mac80211_hwsim: unregister %d radios\n",
 532                hwsim_radio_count);
 533
 534         unregister_netdev(hwsim_mon);
 535         mac80211_hwsim_free();
 536 }
 537
 538
 539 module_init(init_mac80211_hwsim);
 540 module_exit(exit_mac80211_hwsim);