mac80211_hwsim is a Linux kernel module that can be used to simulate arbitrary number of IEEE 802.11 radios for mac80211 on a single device. It can be used to test most of the mac80211 functionality and user space tools (e.g., hostapd and wpa_supplicant) in a way that matches very closely with the normal case of using real WLAN hardware. From the mac80211 view point, mac80211_hwsim is yet another hardware driver, i.e., no changes to mac80211 are needed to use this testing tool. Signed-off-by: Jouni Malinen <j@xxxxx> diff --git a/Documentation/networking/mac80211_hwsim/README b/Documentation/networking/mac80211_hwsim/README new file mode 100644 index 0000000..2f6e90f --- /dev/null +++ b/Documentation/networking/mac80211_hwsim/README @@ -0,0 +1,68 @@ +mac80211_hwsim - software simulator of 802.11 radio(s) for mac80211 +Copyright (c) 2008, Jouni Malinen <j@xxxxx> + +This program is free software; you can redistribute it and/or modify +it under the terms of the GNU General Public License version 2 as +published by the Free Software Foundation. + + +Introduction + +mac80211_hwsim is a Linux kernel module that can be used to simulate +arbitrary number of IEEE 802.11 radios for mac80211 on a single +device. It can be used to test most of the mac80211 functionality and +user space tools (e.g., hostapd and wpa_supplicant) in a way that +matches very closely with the normal case of using real WLAN +hardware. From the mac80211 view point, mac80211_hwsim is yet another +hardware driver, i.e., no changes to mac80211 are needed to use this +testing tool. + +The main goal for mac80211_hwsim is to make it easier for developers +to test their code and work with new features to mac80211, hostapd, +and wpa_supplicant. The simulated radios do not have the limitations +of real hardware, so it is easy to generate an arbitrary test setup +and always reproduce the same setup for future tests. In addition, +since all radio operation is simulated, any channel can be used in +tests regardless of regulatory rules. + +mac80211_hwsim kernel module has a parameter 'radios' that can be used +to select how many radios are simulates (default 2). This allows +configuration of both very simply setups (e.g., just a single access +point and a station) or large scale tests (multiple access points with +hundreds of stations). + +mac80211_hwsim works by tracking the current channel of each virtual +radio and copying all transmitted frames to all other radios that are +currently enabled and on the same channel as the transmitting +radio. Software encryption in mac80211 is used so that the frames are +actually encrypted over the virtual air interface to allow more +complete testing of encryption. + +A global monitoring netdev, hwsim#, is created independent of +mac80211. This interface can be used to monitor all transmitted frames +regardless of channel. + + +Simple example + +This example shows how to use mac80211_hwsim to simulate two radios: +one to act as an access point and the other as a station that +associates with the AP. hostapd and wpa_supplicant are used to take +care of WPA2-PSK authentication. In addition, hostapd is also +processing access point side of association. + +Please note that the current Linux kernel does not enable AP mode, so a +simple patch is needed to enable AP mode selection: +http://johannes.sipsolutions.net/patches/kernel/all/LATEST/006-allow-ap-vlan-modes.patch + + +# Build mac80211_hwsim as part of kernel configuration + +# Load the module +modprobe mac80211_hwsim + +# Run hostapd (AP) for wlan0 +hostapd hostapd.conf + +# Run wpa_supplicant (station) for wlan1 +wpa_supplicant -Dwext -iwlan1 -c wpa_supplicant.conf diff --git a/Documentation/networking/mac80211_hwsim/hostapd.conf b/Documentation/networking/mac80211_hwsim/hostapd.conf new file mode 100644 index 0000000..08cde7e --- /dev/null +++ b/Documentation/networking/mac80211_hwsim/hostapd.conf @@ -0,0 +1,11 @@ +interface=wlan0 +driver=nl80211 + +hw_mode=g +channel=1 +ssid=mac80211 test + +wpa=2 +wpa_key_mgmt=WPA-PSK +wpa_pairwise=CCMP +wpa_passphrase=12345678 diff --git a/Documentation/networking/mac80211_hwsim/wpa_supplicant.conf b/Documentation/networking/mac80211_hwsim/wpa_supplicant.conf new file mode 100644 index 0000000..299128c --- /dev/null +++ b/Documentation/networking/mac80211_hwsim/wpa_supplicant.conf @@ -0,0 +1,10 @@ +ctrl_interface=/var/run/wpa_supplicant + +network={ + ssid="mac80211 test" + psk="12345678" + key_mgmt=WPA-PSK + proto=WPA2 + pairwise=CCMP + group=CCMP +} diff --git a/drivers/net/wireless/Kconfig b/drivers/net/wireless/Kconfig index 86323c8..e3789d5 100644 --- a/drivers/net/wireless/Kconfig +++ b/drivers/net/wireless/Kconfig @@ -681,6 +681,19 @@ config ADM8211 Thanks to Infineon-ADMtek for their support of this driver. +config MAC80211_HWSIM + tristate "Simulated radio testing tool for mac80211" + depends on MAC80211 && WLAN_80211 + ---help--- + This driver is a developer testing tool that can be used to test + IEEE 802.11 networking stack (mac80211) functionality. This is not + needed for normal wireless LAN usage and is only for testing. See + Documentation/networking/mac80211_hwsim for more information on how + to use this tool. + + To compile this driver as a module, choose M here: the module will be + called mac80211_hwsim. If unsure, say N. + source "drivers/net/wireless/p54/Kconfig" source "drivers/net/wireless/ath5k/Kconfig" source "drivers/net/wireless/iwlwifi/Kconfig" diff --git a/drivers/net/wireless/Makefile b/drivers/net/wireless/Makefile index 5026268..72c314e 100644 --- a/drivers/net/wireless/Makefile +++ b/drivers/net/wireless/Makefile @@ -64,3 +64,5 @@ obj-$(CONFIG_RT2X00) += rt2x00/ obj-$(CONFIG_P54_COMMON) += p54/ obj-$(CONFIG_ATH5K) += ath5k/ + +obj-$(CONFIG_MAC80211_HWSIM) += mac80211_hwsim.o diff --git a/drivers/net/wireless/mac80211_hwsim.c b/drivers/net/wireless/mac80211_hwsim.c new file mode 100644 index 0000000..3e33b29 --- /dev/null +++ b/drivers/net/wireless/mac80211_hwsim.c @@ -0,0 +1,533 @@ +/* + * mac80211_hwsim - software simulator of 802.11 radio(s) for mac80211 + * Copyright (c) 2008, Jouni Malinen <j@xxxxx> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +/* + * TODO: + * - IBSS mode simulation (Beacon transmission with competition for "air time") + * - IEEE 802.11a and 802.11n modes + * - RX filtering based on filter configuration (data->rx_filter) + */ + +#include <net/mac80211.h> +#include <net/ieee80211_radiotap.h> +#include <linux/if_arp.h> +#include <linux/rtnetlink.h> +#include <linux/etherdevice.h> + +MODULE_AUTHOR("Jouni Malinen"); +MODULE_DESCRIPTION("Software simulator of 802.11 radio(s) for mac80211"); +MODULE_LICENSE("GPL"); + +static int radios = 2; +module_param(radios, int, 0444); +MODULE_PARM_DESC(radios, "Number of simulated radios"); + + +static struct class *hwsim_class; + +static struct ieee80211_hw **hwsim_radios; +static int hwsim_radio_count; +static struct net_device *hwsim_mon; /* global monitor netdev */ + + +static const struct ieee80211_channel hwsim_channels[] = { + { .center_freq = 2412 }, + { .center_freq = 2417 }, + { .center_freq = 2422 }, + { .center_freq = 2427 }, + { .center_freq = 2432 }, + { .center_freq = 2437 }, + { .center_freq = 2442 }, + { .center_freq = 2447 }, + { .center_freq = 2452 }, + { .center_freq = 2457 }, + { .center_freq = 2462 }, + { .center_freq = 2467 }, + { .center_freq = 2472 }, + { .center_freq = 2484 }, +}; + +static const struct ieee80211_rate hwsim_rates[] = { + { .bitrate = 10 }, + { .bitrate = 20, .flags = IEEE80211_RATE_SHORT_PREAMBLE }, + { .bitrate = 55, .flags = IEEE80211_RATE_SHORT_PREAMBLE }, + { .bitrate = 110, .flags = IEEE80211_RATE_SHORT_PREAMBLE }, + { .bitrate = 60 }, + { .bitrate = 90 }, + { .bitrate = 120 }, + { .bitrate = 180 }, + { .bitrate = 240 }, + { .bitrate = 360 }, + { .bitrate = 480 }, + { .bitrate = 540 } +}; + +struct mac80211_hwsim_data { + struct device *dev; + struct ieee80211_supported_band band; + struct ieee80211_channel channels[ARRAY_SIZE(hwsim_channels)]; + struct ieee80211_rate rates[ARRAY_SIZE(hwsim_rates)]; + + struct ieee80211_channel *channel; + int radio_enabled; + unsigned long beacon_int; /* in jiffies unit */ + unsigned int rx_filter; + int started; + struct timer_list beacon_timer; +}; + + +struct hwsim_radiotap_hdr { + struct ieee80211_radiotap_header hdr; + u8 rt_flags; + u8 rt_rate; + __le16 rt_channel; + __le16 rt_chbitmask; +} __attribute__ ((packed)); + + +static int hwsim_mon_xmit(struct sk_buff *skb, struct net_device *dev) +{ + /* TODO: allow packet injection */ + dev_kfree_skb(skb); + return 0; +} + + +static void mac80211_hwsim_monitor_rx(struct ieee80211_hw *hw, + struct sk_buff *tx_skb) +{ + struct mac80211_hwsim_data *data = hw->priv; + struct sk_buff *skb; + struct hwsim_radiotap_hdr *hdr; + u16 flags; + struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx_skb); + struct ieee80211_rate *txrate = ieee80211_get_tx_rate(hw, info); + + if (!netif_running(hwsim_mon)) + return; + + skb = skb_copy_expand(tx_skb, sizeof(*hdr), 0, GFP_ATOMIC); + if (skb == NULL) + return; + + hdr = (struct hwsim_radiotap_hdr *) skb_push(skb, sizeof(*hdr)); + hdr->hdr.it_version = PKTHDR_RADIOTAP_VERSION; + hdr->hdr.it_pad = 0; + hdr->hdr.it_len = cpu_to_le16(sizeof(*hdr)); + hdr->hdr.it_present = __constant_cpu_to_le32( + (1 << IEEE80211_RADIOTAP_FLAGS) | + (1 << IEEE80211_RADIOTAP_RATE) | + (1 << IEEE80211_RADIOTAP_CHANNEL)); + hdr->rt_flags = 0; + hdr->rt_rate = txrate->bitrate / 5; + hdr->rt_channel = data->channel->center_freq; + flags = IEEE80211_CHAN_2GHZ; + if (txrate->flags & IEEE80211_RATE_ERP_G) + flags |= IEEE80211_CHAN_OFDM; + else + flags |= IEEE80211_CHAN_CCK; + hdr->rt_chbitmask = cpu_to_le16(flags); + + skb->dev = hwsim_mon; + skb_set_mac_header(skb, 0); + skb->ip_summed = CHECKSUM_UNNECESSARY; + skb->pkt_type = PACKET_OTHERHOST; + skb->protocol = __constant_htons(ETH_P_802_2); + memset(skb->cb, 0, sizeof(skb->cb)); + netif_rx(skb); +} + + +static int mac80211_hwsim_tx(struct ieee80211_hw *hw, struct sk_buff *skb) +{ + struct mac80211_hwsim_data *data = hw->priv; + struct ieee80211_rx_status rx_status; + int i, ack = 0; + struct ieee80211_hdr *hdr; + struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); + struct ieee80211_tx_info *txi; + + mac80211_hwsim_monitor_rx(hw, skb); + + if (skb->len < 10) { + /* Should not happen; just a sanity check for addr1 use */ + dev_kfree_skb(skb); + return NETDEV_TX_OK; + } + + if (!data->radio_enabled) { + printk(KERN_DEBUG "%s: dropped TX frame since radio " + "disabled\n", wiphy_name(hw->wiphy)); + dev_kfree_skb(skb); + return NETDEV_TX_OK; + } + + hdr = (struct ieee80211_hdr *) skb->data; + + memset(&rx_status, 0, sizeof(rx_status)); + /* TODO: set mactime */ + rx_status.freq = data->channel->center_freq; + rx_status.band = data->channel->band; + rx_status.rate_idx = info->tx_rate_idx; + /* TODO: simulate signal strength (and optional packet drop) */ + + /* Copy skb to all enabled radios that are on the current frequency */ + for (i = 0; i < hwsim_radio_count; i++) { + struct mac80211_hwsim_data *data2; + struct sk_buff *nskb; + + if (hwsim_radios[i] == NULL || hwsim_radios[i] == hw) + continue; + data2 = hwsim_radios[i]->priv; + if (!data2->started || !data2->radio_enabled || + data->channel->center_freq != data2->channel->center_freq) + continue; + + nskb = skb_copy(skb, GFP_ATOMIC); + if (nskb == NULL) + continue; + + if (memcmp(hdr->addr1, hwsim_radios[i]->wiphy->perm_addr, + ETH_ALEN) == 0) + ack = 1; + ieee80211_rx_irqsafe(hwsim_radios[i], nskb, &rx_status); + } + + txi = IEEE80211_SKB_CB(skb); + memset(&txi->status, 0, sizeof(txi->status)); + if (!(txi->flags & IEEE80211_TX_CTL_NO_ACK)) { + if (ack) + txi->flags |= IEEE80211_TX_STAT_ACK; + else + txi->status.excessive_retries = 1; + } + ieee80211_tx_status_irqsafe(hw, skb); + return NETDEV_TX_OK; +} + + +static int mac80211_hwsim_start(struct ieee80211_hw *hw) +{ + struct mac80211_hwsim_data *data = hw->priv; + printk(KERN_DEBUG "%s:%s\n", wiphy_name(hw->wiphy), __func__); + data->started = 1; + return 0; +} + + +static void mac80211_hwsim_stop(struct ieee80211_hw *hw) +{ + struct mac80211_hwsim_data *data = hw->priv; + data->started = 0; + printk(KERN_DEBUG "%s:%s\n", wiphy_name(hw->wiphy), __func__); +} + + +static int mac80211_hwsim_add_interface(struct ieee80211_hw *hw, + struct ieee80211_if_init_conf *conf) +{ + DECLARE_MAC_BUF(mac); + printk(KERN_DEBUG "%s:%s (type=%d mac_addr=%s)\n", + wiphy_name(hw->wiphy), __func__, conf->type, + print_mac(mac, conf->mac_addr)); + return 0; +} + + +static void mac80211_hwsim_remove_interface( + struct ieee80211_hw *hw, struct ieee80211_if_init_conf *conf) +{ + DECLARE_MAC_BUF(mac); + printk(KERN_DEBUG "%s:%s (type=%d mac_addr=%s)\n", + wiphy_name(hw->wiphy), __func__, conf->type, + print_mac(mac, conf->mac_addr)); +} + + +static void mac80211_hwsim_beacon_tx(void *arg, u8 *mac, + struct ieee80211_vif *vif) +{ + struct ieee80211_hw *hw = arg; + struct mac80211_hwsim_data *data = hw->priv; + struct sk_buff *skb; + struct ieee80211_rx_status rx_status; + int i; + struct ieee80211_tx_info *info; + + if (vif->type != IEEE80211_IF_TYPE_AP) + return; + + skb = ieee80211_beacon_get(hw, vif); + if (skb == NULL) + return; + info = IEEE80211_SKB_CB(skb); + + mac80211_hwsim_monitor_rx(hw, skb); + + memset(&rx_status, 0, sizeof(rx_status)); + /* TODO: set mactime */ + rx_status.freq = data->channel->center_freq; + rx_status.band = data->channel->band; + rx_status.rate_idx = info->tx_rate_idx; + /* TODO: simulate signal strength (and optional packet drop) */ + + /* Copy skb to all enabled radios that are on the current frequency */ + for (i = 0; i < hwsim_radio_count; i++) { + struct mac80211_hwsim_data *data2; + struct sk_buff *nskb; + + if (hwsim_radios[i] == NULL || hwsim_radios[i] == hw) + continue; + data2 = hwsim_radios[i]->priv; + if (!data2->started || !data2->radio_enabled || + data->channel->center_freq != data2->channel->center_freq) + continue; + + nskb = skb_copy(skb, GFP_ATOMIC); + if (nskb == NULL) + continue; + + ieee80211_rx_irqsafe(hwsim_radios[i], nskb, &rx_status); + } + + dev_kfree_skb(skb); +} + + +static void mac80211_hwsim_beacon(unsigned long arg) +{ + struct ieee80211_hw *hw = (struct ieee80211_hw *) arg; + struct mac80211_hwsim_data *data = hw->priv; + + if (!data->started || !data->radio_enabled) + return; + + ieee80211_iterate_active_interfaces(hw, mac80211_hwsim_beacon_tx, hw); + + data->beacon_timer.expires = jiffies + data->beacon_int; + add_timer(&data->beacon_timer); +} + + +static int mac80211_hwsim_config(struct ieee80211_hw *hw, + struct ieee80211_conf *conf) +{ + struct mac80211_hwsim_data *data = hw->priv; + + printk(KERN_DEBUG "%s:%s (freq=%d radio_enabled=%d beacon_int=%d)\n", + wiphy_name(hw->wiphy), __func__, + conf->channel->center_freq, conf->radio_enabled, + conf->beacon_int); + + data->channel = conf->channel; + data->radio_enabled = conf->radio_enabled; + data->beacon_int = 1024 * conf->beacon_int / 1000 * HZ / 1000; + if (data->beacon_int < 1) + data->beacon_int = 1; + + if (!data->started || !data->radio_enabled) + del_timer(&data->beacon_timer); + else + mod_timer(&data->beacon_timer, jiffies + data->beacon_int); + + return 0; +} + + +static void mac80211_hwsim_configure_filter(struct ieee80211_hw *hw, + unsigned int changed_flags, + unsigned int *total_flags, + int mc_count, + struct dev_addr_list *mc_list) +{ + struct mac80211_hwsim_data *data = hw->priv; + + printk(KERN_DEBUG "%s:%s\n", wiphy_name(hw->wiphy), __func__); + + data->rx_filter = 0; + if (*total_flags & FIF_PROMISC_IN_BSS) + data->rx_filter |= FIF_PROMISC_IN_BSS; + if (*total_flags & FIF_ALLMULTI) + data->rx_filter |= FIF_ALLMULTI; + + *total_flags = data->rx_filter; +} + + + +static const struct ieee80211_ops mac80211_hwsim_ops = +{ + .tx = mac80211_hwsim_tx, + .start = mac80211_hwsim_start, + .stop = mac80211_hwsim_stop, + .add_interface = mac80211_hwsim_add_interface, + .remove_interface = mac80211_hwsim_remove_interface, + .config = mac80211_hwsim_config, + .configure_filter = mac80211_hwsim_configure_filter, +}; + + +static void mac80211_hwsim_free(void) +{ + int i; + + for (i = 0; i < hwsim_radio_count; i++) { + if (hwsim_radios[i]) { + struct mac80211_hwsim_data *data; + data = hwsim_radios[i]->priv; + ieee80211_unregister_hw(hwsim_radios[i]); + if (!IS_ERR(data->dev)) + device_unregister(data->dev); + ieee80211_free_hw(hwsim_radios[i]); + } + } + kfree(hwsim_radios); + class_destroy(hwsim_class); +} + + +static struct device_driver mac80211_hwsim_driver = { + .name = "mac80211_hwsim" +}; + + +static void hwsim_mon_setup(struct net_device *dev) +{ + dev->hard_start_xmit = hwsim_mon_xmit; + dev->destructor = free_netdev; + ether_setup(dev); + dev->tx_queue_len = 0; + dev->type = ARPHRD_IEEE80211_RADIOTAP; + memset(dev->dev_addr, 0, ETH_ALEN); + dev->dev_addr[0] = 0x12; +} + + +static int __init init_mac80211_hwsim(void) +{ + int i, err = 0; + u8 addr[ETH_ALEN]; + struct mac80211_hwsim_data *data; + struct ieee80211_hw *hw; + DECLARE_MAC_BUF(mac); + + if (radios < 1 || radios > 65535) + return -EINVAL; + + hwsim_radio_count = radios; + hwsim_radios = kcalloc(hwsim_radio_count, + sizeof(struct ieee80211_hw *), GFP_KERNEL); + if (hwsim_radios == NULL) + return -ENOMEM; + + hwsim_class = class_create(THIS_MODULE, "mac80211_hwsim"); + if (IS_ERR(hwsim_class)) { + kfree(hwsim_radios); + return PTR_ERR(hwsim_class); + } + + memset(addr, 0, ETH_ALEN); + addr[0] = 0x02; + + for (i = 0; i < hwsim_radio_count; i++) { + printk(KERN_DEBUG "mac80211_hwsim: Initializing radio %d\n", + i); + hw = ieee80211_alloc_hw(sizeof(*data), &mac80211_hwsim_ops); + if (hw == NULL) { + printk(KERN_DEBUG "mac80211_hwsim: ieee80211_alloc_hw " + "failed\n"); + err = -ENOMEM; + goto failed; + } + hwsim_radios[i] = hw; + + data = hw->priv; + data->dev = device_create(hwsim_class, NULL, 0, "hwsim%d", i); + if (IS_ERR(data->dev)) { + printk(KERN_DEBUG "mac80211_hwsim: device_create " + "failed (%ld)\n", PTR_ERR(data->dev)); + err = -ENOMEM; + goto failed; + } + data->dev->driver = &mac80211_hwsim_driver; + dev_set_drvdata(data->dev, hw); + + SET_IEEE80211_DEV(hw, data->dev); + addr[3] = i >> 8; + addr[4] = i; + SET_IEEE80211_PERM_ADDR(hw, addr); + + hw->channel_change_time = 1; + hw->queues = 1; + + memcpy(data->channels, hwsim_channels, sizeof(hwsim_channels)); + memcpy(data->rates, hwsim_rates, sizeof(hwsim_rates)); + data->band.channels = data->channels; + data->band.n_channels = ARRAY_SIZE(hwsim_channels); + data->band.bitrates = data->rates; + data->band.n_bitrates = ARRAY_SIZE(hwsim_rates); + hw->wiphy->bands[IEEE80211_BAND_2GHZ] = &data->band; + + err = ieee80211_register_hw(hw); + if (err < 0) { + printk(KERN_DEBUG "mac80211_hwsim: " + "ieee80211_register_hw failed (%d)\n", err); + goto failed; + } + + printk(KERN_DEBUG "%s: hwaddr %s registered\n", + wiphy_name(hw->wiphy), + print_mac(mac, hw->wiphy->perm_addr)); + + setup_timer(&data->beacon_timer, mac80211_hwsim_beacon, + (unsigned long) hw); + } + + hwsim_mon = alloc_netdev(0, "hwsim%d", hwsim_mon_setup); + if (hwsim_mon == NULL) + goto failed; + + rtnl_lock(); + + err = dev_alloc_name(hwsim_mon, hwsim_mon->name); + if (err < 0) { + goto failed_mon; + } + + err = register_netdevice(hwsim_mon); + if (err < 0) + goto failed_mon; + + rtnl_unlock(); + + return 0; + +failed_mon: + rtnl_unlock(); + free_netdev(hwsim_mon); + +failed: + mac80211_hwsim_free(); + return err; +} + + +static void __exit exit_mac80211_hwsim(void) +{ + printk(KERN_DEBUG "mac80211_hwsim: unregister %d radios\n", + hwsim_radio_count); + + unregister_netdev(hwsim_mon); + mac80211_hwsim_free(); +} + + +module_init(init_mac80211_hwsim); +module_exit(exit_mac80211_hwsim); -- Jouni Malinen PGP id EFC895FA -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
