diff options
Diffstat (limited to 'net/mac80211/scan.c')
-rw-r--r-- | net/mac80211/scan.c | 553 |
1 files changed, 553 insertions, 0 deletions
diff --git a/net/mac80211/scan.c b/net/mac80211/scan.c new file mode 100644 index 000000000000..68fa782acd75 --- /dev/null +++ b/net/mac80211/scan.c @@ -0,0 +1,553 @@ +/* + * BSS client mode implementation + * Copyright 2003, Jouni Malinen <jkmaline@cc.hut.fi> + * Copyright 2004, Instant802 Networks, Inc. + * Copyright 2005, Devicescape Software, Inc. + * Copyright 2006-2007 Jiri Benc <jbenc@suse.cz> + * Copyright 2007, Michael Wu <flamingice@sourmilk.net> + * + * 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. + */ + +#include <linux/wireless.h> +#include <linux/if_arp.h> +#include <net/mac80211.h> +#include <net/iw_handler.h> + +#include "ieee80211_i.h" + +#define IEEE80211_PROBE_DELAY (HZ / 33) +#define IEEE80211_CHANNEL_TIME (HZ / 33) +#define IEEE80211_PASSIVE_CHANNEL_TIME (HZ / 5) + + +static void ieee80211_send_nullfunc(struct ieee80211_local *local, + struct ieee80211_sub_if_data *sdata, + int powersave) +{ + struct sk_buff *skb; + struct ieee80211_hdr *nullfunc; + __le16 fc; + + skb = dev_alloc_skb(local->hw.extra_tx_headroom + 24); + if (!skb) { + printk(KERN_DEBUG "%s: failed to allocate buffer for nullfunc " + "frame\n", sdata->dev->name); + return; + } + skb_reserve(skb, local->hw.extra_tx_headroom); + + nullfunc = (struct ieee80211_hdr *) skb_put(skb, 24); + memset(nullfunc, 0, 24); + fc = cpu_to_le16(IEEE80211_FTYPE_DATA | IEEE80211_STYPE_NULLFUNC | + IEEE80211_FCTL_TODS); + if (powersave) + fc |= cpu_to_le16(IEEE80211_FCTL_PM); + nullfunc->frame_control = fc; + memcpy(nullfunc->addr1, sdata->u.sta.bssid, ETH_ALEN); + memcpy(nullfunc->addr2, sdata->dev->dev_addr, ETH_ALEN); + memcpy(nullfunc->addr3, sdata->u.sta.bssid, ETH_ALEN); + + ieee80211_sta_tx(sdata, skb, 0); +} + +static void ieee80211_restart_sta_timer(struct ieee80211_sub_if_data *sdata) +{ + if (sdata->vif.type == IEEE80211_IF_TYPE_STA || + ieee80211_vif_is_mesh(&sdata->vif)) + ieee80211_sta_timer((unsigned long)sdata); +} + +void ieee80211_scan_completed(struct ieee80211_hw *hw) +{ + struct ieee80211_local *local = hw_to_local(hw); + struct ieee80211_sub_if_data *sdata; + union iwreq_data wrqu; + + local->last_scan_completed = jiffies; + memset(&wrqu, 0, sizeof(wrqu)); + wireless_send_event(local->scan_sdata->dev, SIOCGIWSCAN, &wrqu, NULL); + + if (local->sta_hw_scanning) { + local->sta_hw_scanning = 0; + if (ieee80211_hw_config(local)) + printk(KERN_DEBUG "%s: failed to restore operational " + "channel after scan\n", wiphy_name(local->hw.wiphy)); + /* Restart STA timer for HW scan case */ + rcu_read_lock(); + list_for_each_entry_rcu(sdata, &local->interfaces, list) + ieee80211_restart_sta_timer(sdata); + rcu_read_unlock(); + + goto done; + } + + local->sta_sw_scanning = 0; + if (ieee80211_hw_config(local)) + printk(KERN_DEBUG "%s: failed to restore operational " + "channel after scan\n", wiphy_name(local->hw.wiphy)); + + + netif_tx_lock_bh(local->mdev); + netif_addr_lock(local->mdev); + local->filter_flags &= ~FIF_BCN_PRBRESP_PROMISC; + local->ops->configure_filter(local_to_hw(local), + FIF_BCN_PRBRESP_PROMISC, + &local->filter_flags, + local->mdev->mc_count, + local->mdev->mc_list); + + netif_addr_unlock(local->mdev); + netif_tx_unlock_bh(local->mdev); + + rcu_read_lock(); + list_for_each_entry_rcu(sdata, &local->interfaces, list) { + /* Tell AP we're back */ + if (sdata->vif.type == IEEE80211_IF_TYPE_STA) { + if (sdata->u.sta.flags & IEEE80211_STA_ASSOCIATED) { + ieee80211_send_nullfunc(local, sdata, 0); + netif_tx_wake_all_queues(sdata->dev); + } + } else + netif_tx_wake_all_queues(sdata->dev); + + ieee80211_restart_sta_timer(sdata); + } + rcu_read_unlock(); + + done: + ieee80211_mlme_notify_scan_completed(local); +} +EXPORT_SYMBOL(ieee80211_scan_completed); + + +void ieee80211_sta_scan_work(struct work_struct *work) +{ + struct ieee80211_local *local = + container_of(work, struct ieee80211_local, scan_work.work); + struct ieee80211_sub_if_data *sdata = local->scan_sdata; + struct ieee80211_supported_band *sband; + struct ieee80211_channel *chan; + int skip; + unsigned long next_delay = 0; + + if (!local->sta_sw_scanning) + return; + + switch (local->scan_state) { + case SCAN_SET_CHANNEL: + /* + * Get current scan band. scan_band may be IEEE80211_NUM_BANDS + * after we successfully scanned the last channel of the last + * band (and the last band is supported by the hw) + */ + if (local->scan_band < IEEE80211_NUM_BANDS) + sband = local->hw.wiphy->bands[local->scan_band]; + else + sband = NULL; + + /* + * If we are at an unsupported band and have more bands + * left to scan, advance to the next supported one. + */ + while (!sband && local->scan_band < IEEE80211_NUM_BANDS - 1) { + local->scan_band++; + sband = local->hw.wiphy->bands[local->scan_band]; + local->scan_channel_idx = 0; + } + + /* if no more bands/channels left, complete scan */ + if (!sband || local->scan_channel_idx >= sband->n_channels) { + ieee80211_scan_completed(local_to_hw(local)); + return; + } + skip = 0; + chan = &sband->channels[local->scan_channel_idx]; + + if (chan->flags & IEEE80211_CHAN_DISABLED || + (sdata->vif.type == IEEE80211_IF_TYPE_IBSS && + chan->flags & IEEE80211_CHAN_NO_IBSS)) + skip = 1; + + if (!skip) { + local->scan_channel = chan; + if (ieee80211_hw_config(local)) { + printk(KERN_DEBUG "%s: failed to set freq to " + "%d MHz for scan\n", wiphy_name(local->hw.wiphy), + chan->center_freq); + skip = 1; + } + } + + /* advance state machine to next channel/band */ + local->scan_channel_idx++; + if (local->scan_channel_idx >= sband->n_channels) { + /* + * scan_band may end up == IEEE80211_NUM_BANDS, but + * we'll catch that case above and complete the scan + * if that is the case. + */ + local->scan_band++; + local->scan_channel_idx = 0; + } + + if (skip) + break; + + next_delay = IEEE80211_PROBE_DELAY + + usecs_to_jiffies(local->hw.channel_change_time); + local->scan_state = SCAN_SEND_PROBE; + break; + case SCAN_SEND_PROBE: + next_delay = IEEE80211_PASSIVE_CHANNEL_TIME; + local->scan_state = SCAN_SET_CHANNEL; + + if (local->scan_channel->flags & IEEE80211_CHAN_PASSIVE_SCAN) + break; + ieee80211_send_probe_req(sdata, NULL, local->scan_ssid, + local->scan_ssid_len); + next_delay = IEEE80211_CHANNEL_TIME; + break; + } + + if (local->sta_sw_scanning) + queue_delayed_work(local->hw.workqueue, &local->scan_work, + next_delay); +} + + +int ieee80211_sta_start_scan(struct ieee80211_sub_if_data *scan_sdata, + u8 *ssid, size_t ssid_len) +{ + struct ieee80211_local *local = scan_sdata->local; + struct ieee80211_sub_if_data *sdata; + + if (ssid_len > IEEE80211_MAX_SSID_LEN) + return -EINVAL; + + /* MLME-SCAN.request (page 118) page 144 (11.1.3.1) + * BSSType: INFRASTRUCTURE, INDEPENDENT, ANY_BSS + * BSSID: MACAddress + * SSID + * ScanType: ACTIVE, PASSIVE + * ProbeDelay: delay (in microseconds) to be used prior to transmitting + * a Probe frame during active scanning + * ChannelList + * MinChannelTime (>= ProbeDelay), in TU + * MaxChannelTime: (>= MinChannelTime), in TU + */ + + /* MLME-SCAN.confirm + * BSSDescriptionSet + * ResultCode: SUCCESS, INVALID_PARAMETERS + */ + + if (local->sta_sw_scanning || local->sta_hw_scanning) { + if (local->scan_sdata == scan_sdata) + return 0; + return -EBUSY; + } + + if (local->ops->hw_scan) { + int rc = local->ops->hw_scan(local_to_hw(local), + ssid, ssid_len); + if (!rc) { + local->sta_hw_scanning = 1; + local->scan_sdata = scan_sdata; + } + return rc; + } + + local->sta_sw_scanning = 1; + + rcu_read_lock(); + list_for_each_entry_rcu(sdata, &local->interfaces, list) { + if (sdata->vif.type == IEEE80211_IF_TYPE_STA) { + if (sdata->u.sta.flags & IEEE80211_STA_ASSOCIATED) { + netif_tx_stop_all_queues(sdata->dev); + ieee80211_send_nullfunc(local, sdata, 1); + } + } else + netif_tx_stop_all_queues(sdata->dev); + } + rcu_read_unlock(); + + if (ssid) { + local->scan_ssid_len = ssid_len; + memcpy(local->scan_ssid, ssid, ssid_len); + } else + local->scan_ssid_len = 0; + local->scan_state = SCAN_SET_CHANNEL; + local->scan_channel_idx = 0; + local->scan_band = IEEE80211_BAND_2GHZ; + local->scan_sdata = scan_sdata; + + netif_addr_lock_bh(local->mdev); + local->filter_flags |= FIF_BCN_PRBRESP_PROMISC; + local->ops->configure_filter(local_to_hw(local), + FIF_BCN_PRBRESP_PROMISC, + &local->filter_flags, + local->mdev->mc_count, + local->mdev->mc_list); + netif_addr_unlock_bh(local->mdev); + + /* TODO: start scan as soon as all nullfunc frames are ACKed */ + queue_delayed_work(local->hw.workqueue, &local->scan_work, + IEEE80211_CHANNEL_TIME); + + return 0; +} + + +int ieee80211_sta_req_scan(struct ieee80211_sub_if_data *sdata, u8 *ssid, size_t ssid_len) +{ + struct ieee80211_if_sta *ifsta = &sdata->u.sta; + struct ieee80211_local *local = sdata->local; + + if (sdata->vif.type != IEEE80211_IF_TYPE_STA) + return ieee80211_sta_start_scan(sdata, ssid, ssid_len); + + if (local->sta_sw_scanning || local->sta_hw_scanning) { + if (local->scan_sdata == sdata) + return 0; + return -EBUSY; + } + + ifsta->scan_ssid_len = ssid_len; + if (ssid_len) + memcpy(ifsta->scan_ssid, ssid, ssid_len); + set_bit(IEEE80211_STA_REQ_SCAN, &ifsta->request); + queue_work(local->hw.workqueue, &ifsta->work); + return 0; +} + + +static void ieee80211_sta_add_scan_ies(struct iw_request_info *info, + struct ieee80211_sta_bss *bss, + char **current_ev, char *end_buf) +{ + u8 *pos, *end, *next; + struct iw_event iwe; + + if (bss == NULL || bss->ies == NULL) + return; + + /* + * If needed, fragment the IEs buffer (at IE boundaries) into short + * enough fragments to fit into IW_GENERIC_IE_MAX octet messages. + */ + pos = bss->ies; + end = pos + bss->ies_len; + + while (end - pos > IW_GENERIC_IE_MAX) { + next = pos + 2 + pos[1]; + while (next + 2 + next[1] - pos < IW_GENERIC_IE_MAX) + next = next + 2 + next[1]; + + memset(&iwe, 0, sizeof(iwe)); + iwe.cmd = IWEVGENIE; + iwe.u.data.length = next - pos; + *current_ev = iwe_stream_add_point(info, *current_ev, + end_buf, &iwe, pos); + + pos = next; + } + + if (end > pos) { + memset(&iwe, 0, sizeof(iwe)); + iwe.cmd = IWEVGENIE; + iwe.u.data.length = end - pos; + *current_ev = iwe_stream_add_point(info, *current_ev, + end_buf, &iwe, pos); + } +} + + +static char * +ieee80211_sta_scan_result(struct ieee80211_local *local, + struct iw_request_info *info, + struct ieee80211_sta_bss *bss, + char *current_ev, char *end_buf) +{ + struct iw_event iwe; + char *buf; + + if (time_after(jiffies, + bss->last_update + IEEE80211_SCAN_RESULT_EXPIRE)) + return current_ev; + + memset(&iwe, 0, sizeof(iwe)); + iwe.cmd = SIOCGIWAP; + iwe.u.ap_addr.sa_family = ARPHRD_ETHER; + memcpy(iwe.u.ap_addr.sa_data, bss->bssid, ETH_ALEN); + current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe, + IW_EV_ADDR_LEN); + + memset(&iwe, 0, sizeof(iwe)); + iwe.cmd = SIOCGIWESSID; + if (bss_mesh_cfg(bss)) { + iwe.u.data.length = bss_mesh_id_len(bss); + iwe.u.data.flags = 1; + current_ev = iwe_stream_add_point(info, current_ev, end_buf, + &iwe, bss_mesh_id(bss)); + } else { + iwe.u.data.length = bss->ssid_len; + iwe.u.data.flags = 1; + current_ev = iwe_stream_add_point(info, current_ev, end_buf, + &iwe, bss->ssid); + } + + if (bss->capability & (WLAN_CAPABILITY_ESS | WLAN_CAPABILITY_IBSS) + || bss_mesh_cfg(bss)) { + memset(&iwe, 0, sizeof(iwe)); + iwe.cmd = SIOCGIWMODE; + if (bss_mesh_cfg(bss)) + iwe.u.mode = IW_MODE_MESH; + else if (bss->capability & WLAN_CAPABILITY_ESS) + iwe.u.mode = IW_MODE_MASTER; + else + iwe.u.mode = IW_MODE_ADHOC; + current_ev = iwe_stream_add_event(info, current_ev, end_buf, + &iwe, IW_EV_UINT_LEN); + } + + memset(&iwe, 0, sizeof(iwe)); + iwe.cmd = SIOCGIWFREQ; + iwe.u.freq.m = ieee80211_frequency_to_channel(bss->freq); + iwe.u.freq.e = 0; + current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe, + IW_EV_FREQ_LEN); + + memset(&iwe, 0, sizeof(iwe)); + iwe.cmd = SIOCGIWFREQ; + iwe.u.freq.m = bss->freq; + iwe.u.freq.e = 6; + current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe, + IW_EV_FREQ_LEN); + memset(&iwe, 0, sizeof(iwe)); + iwe.cmd = IWEVQUAL; + iwe.u.qual.qual = bss->qual; + iwe.u.qual.level = bss->signal; + iwe.u.qual.noise = bss->noise; + iwe.u.qual.updated = local->wstats_flags; + current_ev = iwe_stream_add_event(info, current_ev, end_buf, &iwe, + IW_EV_QUAL_LEN); + + memset(&iwe, 0, sizeof(iwe)); + iwe.cmd = SIOCGIWENCODE; + if (bss->capability & WLAN_CAPABILITY_PRIVACY) + iwe.u.data.flags = IW_ENCODE_ENABLED | IW_ENCODE_NOKEY; + else + iwe.u.data.flags = IW_ENCODE_DISABLED; + iwe.u.data.length = 0; + current_ev = iwe_stream_add_point(info, current_ev, end_buf, + &iwe, ""); + + ieee80211_sta_add_scan_ies(info, bss, ¤t_ev, end_buf); + + if (bss->supp_rates_len > 0) { + /* display all supported rates in readable format */ + char *p = current_ev + iwe_stream_lcp_len(info); + int i; + + memset(&iwe, 0, sizeof(iwe)); + iwe.cmd = SIOCGIWRATE; + /* Those two flags are ignored... */ + iwe.u.bitrate.fixed = iwe.u.bitrate.disabled = 0; + + for (i = 0; i < bss->supp_rates_len; i++) { + iwe.u.bitrate.value = ((bss->supp_rates[i] & + 0x7f) * 500000); + p = iwe_stream_add_value(info, current_ev, p, + end_buf, &iwe, IW_EV_PARAM_LEN); + } + current_ev = p; + } + + buf = kmalloc(30, GFP_ATOMIC); + if (buf) { + memset(&iwe, 0, sizeof(iwe)); + iwe.cmd = IWEVCUSTOM; + sprintf(buf, "tsf=%016llx", (unsigned long long)(bss->timestamp)); + iwe.u.data.length = strlen(buf); + current_ev = iwe_stream_add_point(info, current_ev, end_buf, + &iwe, buf); + memset(&iwe, 0, sizeof(iwe)); + iwe.cmd = IWEVCUSTOM; + sprintf(buf, " Last beacon: %dms ago", + jiffies_to_msecs(jiffies - bss->last_update)); + iwe.u.data.length = strlen(buf); + current_ev = iwe_stream_add_point(info, current_ev, + end_buf, &iwe, buf); + kfree(buf); + } + + if (bss_mesh_cfg(bss)) { + u8 *cfg = bss_mesh_cfg(bss); + buf = kmalloc(50, GFP_ATOMIC); + if (buf) { + memset(&iwe, 0, sizeof(iwe)); + iwe.cmd = IWEVCUSTOM; + sprintf(buf, "Mesh network (version %d)", cfg[0]); + iwe.u.data.length = strlen(buf); + current_ev = iwe_stream_add_point(info, current_ev, + end_buf, + &iwe, buf); + sprintf(buf, "Path Selection Protocol ID: " + "0x%02X%02X%02X%02X", cfg[1], cfg[2], cfg[3], + cfg[4]); + iwe.u.data.length = strlen(buf); + current_ev = iwe_stream_add_point(info, current_ev, + end_buf, + &iwe, buf); + sprintf(buf, "Path Selection Metric ID: " + "0x%02X%02X%02X%02X", cfg[5], cfg[6], cfg[7], + cfg[8]); + iwe.u.data.length = strlen(buf); + current_ev = iwe_stream_add_point(info, current_ev, + end_buf, + &iwe, buf); + sprintf(buf, "Congestion Control Mode ID: " + "0x%02X%02X%02X%02X", cfg[9], cfg[10], + cfg[11], cfg[12]); + iwe.u.data.length = strlen(buf); + current_ev = iwe_stream_add_point(info, current_ev, + end_buf, + &iwe, buf); + sprintf(buf, "Channel Precedence: " + "0x%02X%02X%02X%02X", cfg[13], cfg[14], + cfg[15], cfg[16]); + iwe.u.data.length = strlen(buf); + current_ev = iwe_stream_add_point(info, current_ev, + end_buf, + &iwe, buf); + kfree(buf); + } + } + + return current_ev; +} + + +int ieee80211_sta_scan_results(struct ieee80211_local *local, + struct iw_request_info *info, + char *buf, size_t len) +{ + char *current_ev = buf; + char *end_buf = buf + len; + struct ieee80211_sta_bss *bss; + + spin_lock_bh(&local->sta_bss_lock); + list_for_each_entry(bss, &local->sta_bss_list, list) { + if (buf + len - current_ev <= IW_EV_ADDR_LEN) { + spin_unlock_bh(&local->sta_bss_lock); + return -E2BIG; + } + current_ev = ieee80211_sta_scan_result(local, info, bss, + current_ev, end_buf); + } + spin_unlock_bh(&local->sta_bss_lock); + return current_ev - buf; +} |