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 competion 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         int beacon_int;
  83         unsigned int rx_filter;
  84         int started;
  85 };
  86
  87
  88 struct hwsim_radiotap_hdr {
  89         struct ieee80211_radiotap_header hdr;
  90         u8 rt_flags;
  91         u8 rt_rate;
  92         __le16 rt_channel;
  93         __le16 rt_chbitmask;
  94 } __attribute__ ((packed));
  95
  96
  97 static int hwsim_mon_xmit(struct sk_buff *skb, struct net_device *dev)
  98 {
  99         /* TODO: allow packet injection */
 100         dev_kfree_skb(skb);
 101         return 0;
 102 }
 103
 104
 105 static void mac80211_hwsim_monitor_rx(struct mac80211_hwsim_data *data,
 106                                       struct sk_buff *tx_skb,
 107                                       struct ieee80211_tx_control *control)
 108 {
 109         struct sk_buff *skb;
 110         struct hwsim_radiotap_hdr *hdr;
 111         u16 flags;
 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 = control->tx_rate / 5;
 130         hdr->rt_channel = data->freq;
 131         flags = IEEE80211_CHAN_2GHZ;
 132         if (control->rate->flags & IEEE80211_RATE_OFDM)
 133                 flags |= IEEE80211_CHAN_OFDM;
 134         if (control->rate->flags & IEEE80211_RATE_CCK)
 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                              struct ieee80211_tx_control *control)
 150 {
 151         struct mac80211_hwsim_data *data = hw->priv;
 152         struct ieee80211_tx_status tx_status;
 153         struct ieee80211_rx_status rx_status;
 154         int i, ack = 0;
 155         struct ieee80211_hdr *hdr;
 156
 157         mac80211_hwsim_monitor_rx(data, skb, control);
 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         if (is_multicast_ether_addr(hdr->addr1))
 174                 ack = 1;
 175
 176         memset(&rx_status, 0, sizeof(rx_status));
 177         /* TODO: set mactime */
 178         rx_status.freq = data->freq;
 179         rx_status.channel = data->channel;
 180         rx_status.phymode = data->phymode;
 181         rx_status.rate = control->tx_rate;
 182         /* TODO: simulate signal strength (and optional packet drop) */
 183
 184         /* Copy skb to all enabled radios that are on the current frequency */
 185         for (i = 0; i < hwsim_radio_count; i++) {
 186                 struct mac80211_hwsim_data *data2;
 187                 struct sk_buff *nskb;
 188
 189                 if (hwsim_radios[i] == NULL || hwsim_radios[i] == hw)
 190                         continue;
 191                 data2 = hwsim_radios[i]->priv;
 192                 if (!data2->started || !data2->radio_enabled ||
 193                     data->freq != data2->freq)
 194                         continue;
 195
 196                 nskb = skb_copy(skb, GFP_ATOMIC);
 197                 if (nskb == NULL)
 198                         continue;
 199
 200                 if (memcmp(hdr->addr1, hwsim_radios[i]->wiphy->perm_addr,
 201                            ETH_ALEN) == 0)
 202                         ack = 1;
 203                 ieee80211_rx_irqsafe(hwsim_radios[i], nskb, &rx_status);
 204         }
 205
 206         memset(&tx_status, 0, sizeof(tx_status));
 207         memcpy(&tx_status.control, control, sizeof(*control));
 208         tx_status.flags = ack ? IEEE80211_TX_STATUS_ACK : 0;
 209         ieee80211_tx_status_irqsafe(hw, skb, &tx_status);
 210         return NETDEV_TX_OK;
 211 }
 212
 213
 214 static int mac80211_hwsim_start(struct ieee80211_hw *hw)
 215 {
 216         struct mac80211_hwsim_data *data = hw->priv;
 217         printk(KERN_DEBUG "%s:%s\n", wiphy_name(hw->wiphy), __func__);
 218         data->started = 1;
 219         return 0;
 220 }
 221
 222
 223 static void mac80211_hwsim_stop(struct ieee80211_hw *hw)
 224 {
 225         struct mac80211_hwsim_data *data = hw->priv;
 226         data->started = 0;
 227         printk(KERN_DEBUG "%s:%s\n", wiphy_name(hw->wiphy), __func__);
 228 }
 229
 230
 231 static int mac80211_hwsim_add_interface(struct ieee80211_hw *hw,
 232                                         struct ieee80211_if_init_conf *conf)
 233 {
 234         printk(KERN_DEBUG "%s:%s\n", wiphy_name(hw->wiphy), __func__);
 235         return 0;
 236 }
 237
 238
 239 static void mac80211_hwsim_remove_interface(
 240         struct ieee80211_hw *hw, struct ieee80211_if_init_conf *conf)
 241 {
 242         printk(KERN_DEBUG "%s:%s\n", wiphy_name(hw->wiphy), __func__);
 243 }
 244
 245
 246 static int mac80211_hwsim_config(struct ieee80211_hw *hw,
 247                                  struct ieee80211_conf *conf)
 248 {
 249         struct mac80211_hwsim_data *data = hw->priv;
 250
 251         printk(KERN_DEBUG "%s:%s (freq=%d radio_enabled=%d beacon_int=%d)\n",
 252                wiphy_name(hw->wiphy), __func__,
 253                conf->freq, conf->radio_enabled, conf->beacon_int);
 254
 255         data->freq = conf->freq;
 256         data->channel = conf->channel;
 257         data->phymode = conf->phymode;
 258         data->radio_enabled = conf->radio_enabled;
 259         data->beacon_int = conf->beacon_int;
 260
 261         return 0;
 262 }
 263
 264
 265 static void mac80211_hwsim_configure_filter(struct ieee80211_hw *hw,
 266                                             unsigned int changed_flags,
 267                                             unsigned int *total_flags,
 268                                             int mc_count,
 269                                             struct dev_addr_list *mc_list)
 270 {
 271         struct mac80211_hwsim_data *data = hw->priv;
 272
 273         printk(KERN_DEBUG "%s:%s\n", wiphy_name(hw->wiphy), __func__);
 274
 275         data->rx_filter = 0;
 276         if (*total_flags & FIF_PROMISC_IN_BSS)
 277                 data->rx_filter |= FIF_PROMISC_IN_BSS;
 278         if (*total_flags & FIF_ALLMULTI)
 279                 data->rx_filter |= FIF_ALLMULTI;
 280
 281         *total_flags = data->rx_filter;
 282 }
 283
 284
 285
 286 static const struct ieee80211_ops mac80211_hwsim_ops =
 287 {
 288         .tx = mac80211_hwsim_tx,
 289         .start = mac80211_hwsim_start,
 290         .stop = mac80211_hwsim_stop,
 291         .add_interface = mac80211_hwsim_add_interface,
 292         .remove_interface = mac80211_hwsim_remove_interface,
 293         .config = mac80211_hwsim_config,
 294         .configure_filter = mac80211_hwsim_configure_filter,
 295 };
 296
 297
 298 static void mac80211_hwsim_free(void)
 299 {
 300         int i;
 301
 302         for (i = 0; i < hwsim_radio_count; i++) {
 303                 if (hwsim_radios[i]) {
 304                         struct mac80211_hwsim_data *data;
 305                         data = hwsim_radios[i]->priv;
 306                         ieee80211_unregister_hw(hwsim_radios[i]);
 307                         if (!IS_ERR(data->dev))
 308                                 device_unregister(data->dev);
 309                         ieee80211_free_hw(hwsim_radios[i]);
 310                 }
 311         }
 312         kfree(hwsim_radios);
 313         class_destroy(hwsim_class);
 314 }
 315
 316
 317 static struct device_driver mac80211_hwsim_driver = {
 318         .name = "mac80211_hwsim"
 319 };
 320
 321
 322 static void hwsim_mon_setup(struct net_device *dev)
 323 {
 324         dev->hard_start_xmit = hwsim_mon_xmit;
 325         dev->destructor = free_netdev;
 326         ether_setup(dev);
 327         dev->tx_queue_len = 0;
 328         dev->type = ARPHRD_IEEE80211_RADIOTAP;
 329         memset(dev->dev_addr, 0, ETH_ALEN);
 330         dev->dev_addr[0] = 0x12;
 331 }
 332
 333
 334 static int __init init_mac80211_hwsim(void)
 335 {
 336         int i, err = 0;
 337         u8 addr[ETH_ALEN];
 338         struct mac80211_hwsim_data *data;
 339         struct ieee80211_hw *hw;
 340         DECLARE_MAC_BUF(mac);
 341
 342         if (radios < 1 || radios > 65535)
 343                 return -EINVAL;
 344
 345         hwsim_radio_count = radios;
 346         hwsim_radios = kcalloc(hwsim_radio_count,
 347                                sizeof(struct ieee80211_hw *), GFP_KERNEL);
 348         if (hwsim_radios == NULL)
 349                 return -ENOMEM;
 350
 351         hwsim_class = class_create(THIS_MODULE, "mac80211_hwsim");
 352         if (IS_ERR(hwsim_class)) {
 353                 kfree(hwsim_radios);
 354                 return PTR_ERR(hwsim_class);
 355         }
 356
 357         memset(addr, 0, ETH_ALEN);
 358         addr[0] = 0x02;
 359
 360         for (i = 0; i < hwsim_radio_count; i++) {
 361                 printk(KERN_DEBUG "mac80211_hwsim: Initializing radio %d\n",
 362                        i);
 363                 hw = ieee80211_alloc_hw(sizeof(*data), &mac80211_hwsim_ops);
 364                 if (hw == NULL) {
 365                         printk(KERN_DEBUG "mac80211_hwsim: ieee80211_alloc_hw "
 366                                "failed\n");
 367                         err = -ENOMEM;
 368                         goto failed;
 369                 }
 370                 hwsim_radios[i] = hw;
 371
 372                 data = hw->priv;
 373                 data->dev = device_create(hwsim_class, NULL, 0, "hwsim%d", i);
 374                 if (IS_ERR(data->dev)) {
 375                         printk(KERN_DEBUG "mac80211_hwsim: device_create "
 376                                "failed (%ld)\n", PTR_ERR(data->dev));
 377                         err = -ENOMEM;
 378                         goto failed;
 379                 }
 380                 data->dev->driver = &mac80211_hwsim_driver;
 381                 dev_set_drvdata(data->dev, hw);
 382
 383                 SET_IEEE80211_DEV(hw, data->dev);
 384                 addr[3] = i >> 8;
 385                 addr[4] = i;
 386                 SET_IEEE80211_PERM_ADDR(hw, addr);
 387
 388                 hw->channel_change_time = 1;
 389                 hw->queues = 1;
 390
 391                 memcpy(data->channels, hwsim_channels, sizeof(hwsim_channels));
 392                 memcpy(data->rates, hwsim_rates, sizeof(hwsim_rates));
 393                 data->modes[0].channels = data->channels;
 394                 data->modes[0].rates = data->rates;
 395                 data->modes[0].mode = MODE_IEEE80211G;
 396                 data->modes[0].num_channels = ARRAY_SIZE(hwsim_channels);
 397                 data->modes[0].num_rates = ARRAY_SIZE(hwsim_rates);
 398
 399                 err = ieee80211_register_hwmode(hw, data->modes);
 400                 if (err < 0) {
 401                         printk(KERN_DEBUG "mac80211_hwsim: "
 402                                "ieee80211_register_hwmode failed (%d)\n", err);
 403                         goto failed;
 404                 }
 405
 406                 err = ieee80211_register_hw(hw);
 407                 if (err < 0) {
 408                         printk(KERN_DEBUG "mac80211_hwsim: "
 409                                "ieee80211_register_hw failed (%d)\n", err);
 410                         goto failed;
 411                 }
 412
 413                 printk(KERN_DEBUG "%s: hwaddr %s registered\n",
 414                        wiphy_name(hw->wiphy),
 415                        print_mac(mac, hw->wiphy->perm_addr));
 416         }
 417
 418         hwsim_mon = alloc_netdev(0, "hwsim%d", hwsim_mon_setup);
 419         if (hwsim_mon == NULL)
 420                 goto failed;
 421
 422         rtnl_lock();
 423
 424         err = dev_alloc_name(hwsim_mon, hwsim_mon->name);
 425         if (err < 0) {
 426                 goto failed_mon;
 427         }
 428
 429         err = register_netdevice(hwsim_mon);
 430         if (err < 0)
 431                 goto failed_mon;
 432
 433         rtnl_unlock();
 434
 435         return 0;
 436
 437 failed_mon:
 438         rtnl_unlock();
 439         free_netdev(hwsim_mon);
 440
 441 failed:
 442         mac80211_hwsim_free();
 443         return err;
 444 }
 445
 446
 447 static void __exit exit_mac80211_hwsim(void)
 448 {
 449         printk(KERN_DEBUG "mac80211_hwsim: unregister %d radios\n",
 450                hwsim_radio_count);
 451
 452         unregister_netdev(hwsim_mon);
 453         mac80211_hwsim_free();
 454 }
 455
 456
 457 module_init(init_mac80211_hwsim);
 458 module_exit(exit_mac80211_hwsim);