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
  22 MODULE_AUTHOR("Jouni Malinen");
  23 MODULE_DESCRIPTION("Software simulator of 802.11 radio(s) for mac80211");
  24 MODULE_LICENSE("GPL");
  25
  26 static int radios = 2;
  27 module_param(radios, int, 0444);
  28 MODULE_PARM_DESC(radios, "Number of simulated radios");
  29
  30
  31 static struct class *hwsim_class;
  32
  33 static struct ieee80211_hw **hwsim_radios;
  34 static int hwsim_radio_count;
  35 static struct net_device *hwsim_mon; /* global monitor netdev */
  36
  37
  38 static const struct ieee80211_channel hwsim_channels[] = {
  39         { .chan = 1, .freq = 2412, .val = 1 },
  40         { .chan = 2, .freq = 2417, .val = 2 },
  41         { .chan = 3, .freq = 2422, .val = 3 },
  42         { .chan = 4, .freq = 2427, .val = 4 },
  43         { .chan = 5, .freq = 2432, .val = 5 },
  44         { .chan = 6, .freq = 2437, .val = 6 },
  45         { .chan = 7, .freq = 2442, .val = 7 },
  46         { .chan = 8, .freq = 2447, .val = 8 },
  47         { .chan = 9, .freq = 2452, .val = 9 },
  48         { .chan = 10, .freq = 2457, .val = 10 },
  49         { .chan = 11, .freq = 2462, .val = 11 },
  50         { .chan = 12, .freq = 2467, .val = 12 },
  51         { .chan = 13, .freq = 2472, .val = 13 },
  52         { .chan = 14, .freq = 2484, .val = 14 },
  53 };
  54
  55 static const struct ieee80211_rate hwsim_rates[] = {
  56         { .rate = 10, .val = 10, .flags = IEEE80211_RATE_CCK },
  57         { .rate = 20, .val = 20, .val2 = 21, .flags = IEEE80211_RATE_CCK_2 },
  58         { .rate = 55, .val = 55, .val2 = 56, .flags = IEEE80211_RATE_CCK_2 },
  59         { .rate = 110, .val = 110, .val2 = 111,
  60           .flags = IEEE80211_RATE_CCK_2 },
  61         { .rate = 60, .val = 60, .flags = IEEE80211_RATE_OFDM },
  62         { .rate = 90, .val = 90, .flags = IEEE80211_RATE_OFDM },
  63         { .rate = 120, .val = 120, .flags = IEEE80211_RATE_OFDM },
  64         { .rate = 180, .val = 180, .flags = IEEE80211_RATE_OFDM },
  65         { .rate = 240, .val = 240, .flags = IEEE80211_RATE_OFDM },
  66         { .rate = 360, .val = 360, .flags = IEEE80211_RATE_OFDM },
  67         { .rate = 480, .val = 480, .flags = IEEE80211_RATE_OFDM },
  68         { .rate = 540, .val = 540, .flags = IEEE80211_RATE_OFDM }
  69 };
  70
  71 struct mac80211_hwsim_data {
  72         struct device *dev;
  73         struct ieee80211_hw_mode modes[1];
  74         struct ieee80211_channel channels[ARRAY_SIZE(hwsim_channels)];
  75         struct ieee80211_rate rates[ARRAY_SIZE(hwsim_rates)];
  76
  77         int freq;
  78         int channel;
  79         enum ieee80211_phymode phymode;
  80         int radio_enabled;
  81         int beacon_int;
  82         unsigned int rx_filter;
  83         int started;
  84 };
  85
  86
  87 struct hwsim_radiotap_hdr {
  88         struct ieee80211_radiotap_header hdr;
  89         u8 rt_flags;
  90         u8 rt_rate;
  91         __le16 rt_channel;
  92         __le16 rt_chbitmask;
  93 } __attribute__ ((packed));
  94
  95
  96 static int hwsim_mon_xmit(struct sk_buff *skb, struct net_device *dev)
  97 {
  98         /* TODO: allow packet injection */
  99         dev_kfree_skb(skb);
 100         return 0;
 101 }
 102
 103
 104 static void mac80211_hwsim_monitor_rx(struct mac80211_hwsim_data *data,
 105                                       struct sk_buff *tx_skb,
 106                                       struct ieee80211_tx_control *control)
 107 {
 108         struct sk_buff *skb;
 109         struct hwsim_radiotap_hdr *hdr;
 110         u16 flags;
 111
 112         if (!netif_running(hwsim_mon))
 113                 return;
 114
 115         skb = skb_copy_expand(tx_skb, sizeof(*hdr), 0, GFP_ATOMIC);
 116         if (skb == NULL)
 117                 return;
 118
 119         hdr = (struct hwsim_radiotap_hdr *) skb_push(skb, sizeof(*hdr));
 120         hdr->hdr.it_version = PKTHDR_RADIOTAP_VERSION;
 121         hdr->hdr.it_pad = 0;
 122         hdr->hdr.it_len = cpu_to_le16(sizeof(*hdr));
 123         hdr->hdr.it_present = __constant_cpu_to_le32(
 124              (1 << IEEE80211_RADIOTAP_FLAGS) |
 125              (1 << IEEE80211_RADIOTAP_RATE) |
 126              (1 << IEEE80211_RADIOTAP_CHANNEL));
 127         hdr->rt_flags = 0;
 128         hdr->rt_rate = control->tx_rate / 5;
 129         hdr->rt_channel = data->freq;
 130         flags = IEEE80211_CHAN_2GHZ;
 131         if (control->rate->flags & IEEE80211_RATE_OFDM)
 132                 flags |= IEEE80211_CHAN_OFDM;
 133         if (control->rate->flags & IEEE80211_RATE_CCK)
 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 = __constant_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(struct ieee80211_hw *hw, struct sk_buff *skb,
 148                              struct ieee80211_tx_control *control)
 149 {
 150         struct mac80211_hwsim_data *data = hw->priv;
 151         struct ieee80211_tx_status tx_status;
 152         struct ieee80211_rx_status rx_status;
 153         int i;
 154
 155         mac80211_hwsim_monitor_rx(data, skb, control);
 156
 157         if (!data->radio_enabled) {
 158                 printk(KERN_DEBUG "%s: dropped TX frame since radio "
 159                        "disabled\n", wiphy_name(hw->wiphy));
 160                 dev_kfree_skb(skb);
 161                 return NETDEV_TX_OK;
 162         }
 163
 164         memset(&rx_status, 0, sizeof(rx_status));
 165         /* TODO: set mactime */
 166         rx_status.freq = data->freq;
 167         rx_status.channel = data->channel;
 168         rx_status.phymode = data->phymode;
 169         rx_status.rate = control->tx_rate;
 170         /* TODO: simulate signal strength (and optional packet drop) */
 171
 172         /* Copy skb to all enabled radios that are on the current frequency */
 173         for (i = 0; i < hwsim_radio_count; i++) {
 174                 struct mac80211_hwsim_data *data2;
 175                 struct sk_buff *nskb;
 176
 177                 if (hwsim_radios[i] == NULL || hwsim_radios[i] == hw)
 178                         continue;
 179                 data2 = hwsim_radios[i]->priv;
 180                 if (!data2->started || !data2->radio_enabled ||
 181                     data->freq != data2->freq)
 182                         continue;
 183
 184                 nskb = skb_copy(skb, GFP_ATOMIC);
 185                 if (nskb == NULL)
 186                         continue;
 187
 188                 ieee80211_rx_irqsafe(hwsim_radios[i], nskb, &rx_status);
 189         }
 190
 191         memset(&tx_status, 0, sizeof(tx_status));
 192         memcpy(&tx_status.control, control, sizeof(*control));
 193         /* TODO: proper ACK determination */
 194         tx_status.flags = IEEE80211_TX_STATUS_ACK;
 195         ieee80211_tx_status_irqsafe(hw, skb, &tx_status);
 196         return NETDEV_TX_OK;
 197 }
 198
 199
 200 static int mac80211_hwsim_start(struct ieee80211_hw *hw)
 201 {
 202         struct mac80211_hwsim_data *data = hw->priv;
 203         printk(KERN_DEBUG "%s:%s\n", wiphy_name(hw->wiphy), __func__);
 204         data->started = 1;
 205         return 0;
 206 }
 207
 208
 209 static void mac80211_hwsim_stop(struct ieee80211_hw *hw)
 210 {
 211         struct mac80211_hwsim_data *data = hw->priv;
 212         data->started = 0;
 213         printk(KERN_DEBUG "%s:%s\n", wiphy_name(hw->wiphy), __func__);
 214 }
 215
 216
 217 static int mac80211_hwsim_add_interface(struct ieee80211_hw *hw,
 218                                         struct ieee80211_if_init_conf *conf)
 219 {
 220         printk(KERN_DEBUG "%s:%s\n", wiphy_name(hw->wiphy), __func__);
 221         return 0;
 222 }
 223
 224
 225 static void mac80211_hwsim_remove_interface(
 226         struct ieee80211_hw *hw, struct ieee80211_if_init_conf *conf)
 227 {
 228         printk(KERN_DEBUG "%s:%s\n", wiphy_name(hw->wiphy), __func__);
 229 }
 230
 231
 232 static int mac80211_hwsim_config(struct ieee80211_hw *hw,
 233                                  struct ieee80211_conf *conf)
 234 {
 235         struct mac80211_hwsim_data *data = hw->priv;
 236
 237         printk(KERN_DEBUG "%s:%s (freq=%d radio_enabled=%d beacon_int=%d)\n",
 238                wiphy_name(hw->wiphy), __func__,
 239                conf->freq, conf->radio_enabled, conf->beacon_int);
 240
 241         data->freq = conf->freq;
 242         data->channel = conf->channel;
 243         data->phymode = conf->phymode;
 244         data->radio_enabled = conf->radio_enabled;
 245         data->beacon_int = conf->beacon_int;
 246
 247         return 0;
 248 }
 249
 250
 251 static void mac80211_hwsim_configure_filter(struct ieee80211_hw *hw,
 252                                             unsigned int changed_flags,
 253                                             unsigned int *total_flags,
 254                                             int mc_count,
 255                                             struct dev_addr_list *mc_list)
 256 {
 257         struct mac80211_hwsim_data *data = hw->priv;
 258
 259         printk(KERN_DEBUG "%s:%s\n", wiphy_name(hw->wiphy), __func__);
 260
 261         data->rx_filter = 0;
 262         if (*total_flags & FIF_PROMISC_IN_BSS)
 263                 data->rx_filter |= FIF_PROMISC_IN_BSS;
 264         if (*total_flags & FIF_ALLMULTI)
 265                 data->rx_filter |= FIF_ALLMULTI;
 266
 267         *total_flags = data->rx_filter;
 268 }
 269
 270
 271
 272 static const struct ieee80211_ops mac80211_hwsim_ops =
 273 {
 274         .tx = mac80211_hwsim_tx,
 275         .start = mac80211_hwsim_start,
 276         .stop = mac80211_hwsim_stop,
 277         .add_interface = mac80211_hwsim_add_interface,
 278         .remove_interface = mac80211_hwsim_remove_interface,
 279         .config = mac80211_hwsim_config,
 280         .configure_filter = mac80211_hwsim_configure_filter,
 281 };
 282
 283
 284 static void mac80211_hwsim_free(void)
 285 {
 286         int i;
 287
 288         for (i = 0; i < hwsim_radio_count; i++) {
 289                 if (hwsim_radios[i]) {
 290                         struct mac80211_hwsim_data *data;
 291                         data = hwsim_radios[i]->priv;
 292                         ieee80211_unregister_hw(hwsim_radios[i]);
 293                         if (!IS_ERR(data->dev))
 294                                 device_unregister(data->dev);
 295                         ieee80211_free_hw(hwsim_radios[i]);
 296                 }
 297         }
 298         kfree(hwsim_radios);
 299         class_destroy(hwsim_class);
 300 }
 301
 302
 303 static struct device_driver mac80211_hwsim_driver = {
 304         .name = "mac80211_hwsim"
 305 };
 306
 307
 308 static void hwsim_mon_setup(struct net_device *dev)
 309 {
 310         dev->hard_start_xmit = hwsim_mon_xmit;
 311         dev->destructor = free_netdev;
 312         ether_setup(dev);
 313         dev->tx_queue_len = 0;
 314         dev->type = ARPHRD_IEEE80211_RADIOTAP;
 315         memset(dev->dev_addr, 0, ETH_ALEN);
 316         dev->dev_addr[0] = 0x12;
 317 }
 318
 319
 320 static int __init init_mac80211_hwsim(void)
 321 {
 322         int i, err = 0;
 323         u8 addr[ETH_ALEN];
 324         struct mac80211_hwsim_data *data;
 325         struct ieee80211_hw *hw;
 326         DECLARE_MAC_BUF(mac);
 327
 328         if (radios < 1 || radios > 65535)
 329                 return -EINVAL;
 330
 331         hwsim_radio_count = radios;
 332         hwsim_radios = kcalloc(hwsim_radio_count,
 333                                sizeof(struct ieee80211_hw *), GFP_KERNEL);
 334         if (hwsim_radios == NULL)
 335                 return -ENOMEM;
 336
 337         hwsim_class = class_create(THIS_MODULE, "mac80211_hwsim");
 338         if (IS_ERR(hwsim_class)) {
 339                 kfree(hwsim_radios);
 340                 return PTR_ERR(hwsim_class);
 341         }
 342
 343         memset(addr, 0, ETH_ALEN);
 344         addr[0] = 0x02;
 345
 346         for (i = 0; i < hwsim_radio_count; i++) {
 347                 printk(KERN_DEBUG "mac80211_hwsim: Initializing radio %d\n",
 348                        i);
 349                 hw = ieee80211_alloc_hw(sizeof(*data), &mac80211_hwsim_ops);
 350                 if (hw == NULL) {
 351                         printk(KERN_DEBUG "mac80211_hwsim: ieee80211_alloc_hw "
 352                                "failed\n");
 353                         err = -ENOMEM;
 354                         goto failed;
 355                 }
 356                 hwsim_radios[i] = hw;
 357
 358                 data = hw->priv;
 359                 data->dev = device_create(hwsim_class, NULL, 0, "hwsim%d", i);
 360                 if (IS_ERR(data->dev)) {
 361                         printk(KERN_DEBUG "mac80211_hwsim: device_create "
 362                                "failed (%ld)\n", PTR_ERR(data->dev));
 363                         err = -ENOMEM;
 364                         goto failed;
 365                 }
 366                 data->dev->driver = &mac80211_hwsim_driver;
 367                 dev_set_drvdata(data->dev, hw);
 368
 369                 SET_IEEE80211_DEV(hw, data->dev);
 370                 addr[3] = i >> 8;
 371                 addr[4] = i;
 372                 SET_IEEE80211_PERM_ADDR(hw, addr);
 373
 374                 hw->channel_change_time = 1;
 375                 hw->queues = 1;
 376
 377                 memcpy(data->channels, hwsim_channels, sizeof(hwsim_channels));
 378                 memcpy(data->rates, hwsim_rates, sizeof(hwsim_rates));
 379                 data->modes[0].channels = data->channels;
 380                 data->modes[0].rates = data->rates;
 381                 data->modes[0].mode = MODE_IEEE80211G;
 382                 data->modes[0].num_channels = ARRAY_SIZE(hwsim_channels);
 383                 data->modes[0].num_rates = ARRAY_SIZE(hwsim_rates);
 384
 385                 err = ieee80211_register_hwmode(hw, data->modes);
 386                 if (err < 0) {
 387                         printk(KERN_DEBUG "mac80211_hwsim: "
 388                                "ieee80211_register_hwmode failed (%d)\n", err);
 389                         goto failed;
 390                 }
 391
 392                 err = ieee80211_register_hw(hw);
 393                 if (err < 0) {
 394                         printk(KERN_DEBUG "mac80211_hwsim: "
 395                                "ieee80211_register_hw failed (%d)\n", err);
 396                         goto failed;
 397                 }
 398
 399                 printk(KERN_DEBUG "%s: hwaddr %s registered\n",
 400                        wiphy_name(hw->wiphy),
 401                        print_mac(mac, hw->wiphy->perm_addr));
 402         }
 403
 404         hwsim_mon = alloc_netdev(0, "hwsim%d", hwsim_mon_setup);
 405         if (hwsim_mon == NULL)
 406                 goto failed;
 407
 408         rtnl_lock();
 409
 410         err = dev_alloc_name(hwsim_mon, hwsim_mon->name);
 411         if (err < 0) {
 412                 goto failed_mon;
 413         }
 414
 415         err = register_netdevice(hwsim_mon);
 416         if (err < 0)
 417                 goto failed_mon;
 418
 419         rtnl_unlock();
 420
 421         return 0;
 422
 423 failed_mon:
 424         rtnl_unlock();
 425         free_netdev(hwsim_mon);
 426
 427 failed:
 428         mac80211_hwsim_free();
 429         return err;
 430 }
 431
 432
 433 static void __exit exit_mac80211_hwsim(void)
 434 {
 435         printk(KERN_DEBUG "mac80211_hwsim: unregister %d radios\n",
 436                hwsim_radio_count);
 437
 438         unregister_netdev(hwsim_mon);
 439         mac80211_hwsim_free();
 440 }
 441
 442
 443 module_init(init_mac80211_hwsim);
 444 module_exit(exit_mac80211_hwsim);