From 30b89b0f5e1313c8a5a039abeaa89248b6338d81 Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Wed, 16 Apr 2008 17:43:20 +0200 Subject: [PATCH] mac80211: rework scanning to account for probe response/beacon difference This patch reworks the scanning code (ieee80211_rx_bss_info) to take more parameters from beacons and keep a BSS info structure alive when only beacons for it are received. This fixes a problem with iwlwifi drivers (where we don't understand the root cause of the problem yet) and another driver for some broken hardware (which cannot send probe requests unless associated, so can't always actively scan.) Signed-off-by: Bill Moss [jmberg: reformatted comments, make probe_resp a bool] Signed-off-by: Johannes Berg Signed-off-by: John W. Linville --- net/mac80211/ieee80211_i.h | 2 +- net/mac80211/mlme.c | 85 +++++++++++++++++++++++--------------- 2 files changed, 52 insertions(+), 35 deletions(-) diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h index ce566f3e01..8e53ce7ed4 100644 --- a/net/mac80211/ieee80211_i.h +++ b/net/mac80211/ieee80211_i.h @@ -102,7 +102,7 @@ struct ieee80211_sta_bss { u64 timestamp; int beacon_int; - int probe_resp; + bool probe_resp; unsigned long last_update; /* during assocation, we save an ERP value from a probe response so diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c index e3f2cb0865..6b75cb6c63 100644 --- a/net/mac80211/mlme.c +++ b/net/mac80211/mlme.c @@ -2588,22 +2588,29 @@ static void ieee80211_rx_bss_info(struct net_device *dev, #endif } - bss->band = rx_status->band; - - if (sdata->vif.type != IEEE80211_IF_TYPE_IBSS && - bss->probe_resp && beacon) { - /* STA mode: - * Do not allow beacon to override data from Probe Response. */ - ieee80211_rx_bss_put(dev, bss); - return; - } - /* save the ERP value so that it is available at association time */ if (elems.erp_info && elems.erp_info_len >= 1) { bss->erp_value = elems.erp_info[0]; bss->has_erp_value = 1; } + if (elems.ht_cap_elem && + (!bss->ht_ie || bss->ht_ie_len != elems.ht_cap_elem_len || + memcmp(bss->ht_ie, elems.ht_cap_elem, elems.ht_cap_elem_len))) { + kfree(bss->ht_ie); + bss->ht_ie = kmalloc(elems.ht_cap_elem_len + 2, GFP_ATOMIC); + if (bss->ht_ie) { + memcpy(bss->ht_ie, elems.ht_cap_elem - 2, + elems.ht_cap_elem_len + 2); + bss->ht_ie_len = elems.ht_cap_elem_len + 2; + } else + bss->ht_ie_len = 0; + } else if (!elems.ht_cap_elem && bss->ht_ie) { + kfree(bss->ht_ie); + bss->ht_ie = NULL; + bss->ht_ie_len = 0; + } + bss->beacon_int = le16_to_cpu(mgmt->u.beacon.beacon_int); bss->capability = le16_to_cpu(mgmt->u.beacon.capab_info); @@ -2625,6 +2632,26 @@ static void ieee80211_rx_bss_info(struct net_device *dev, bss->supp_rates_len += clen; } + bss->band = rx_status->band; + + bss->timestamp = beacon_timestamp; + bss->last_update = jiffies; + bss->rssi = rx_status->ssi; + bss->signal = rx_status->signal; + bss->noise = rx_status->noise; + if (!beacon && !bss->probe_resp) + bss->probe_resp = true; + + /* + * In STA mode, the remaining parameters should not be overridden + * by beacons because they're not necessarily accurate there. + */ + if (sdata->vif.type != IEEE80211_IF_TYPE_IBSS && + bss->probe_resp && beacon) { + ieee80211_rx_bss_put(dev, bss); + return; + } + if (elems.wpa && (!bss->wpa_ie || bss->wpa_ie_len != elems.wpa_len || memcmp(bss->wpa_ie, elems.wpa, elems.wpa_len))) { @@ -2657,6 +2684,20 @@ static void ieee80211_rx_bss_info(struct net_device *dev, bss->rsn_ie_len = 0; } + /* + * Cf. + * http://www.wipo.int/pctdb/en/wo.jsp?wo=2007047181&IA=WO2007047181&DISPLAY=DESC + * + * quoting: + * + * In particular, "Wi-Fi CERTIFIED for WMM - Support for Multimedia + * Applications with Quality of Service in Wi-Fi Networks," Wi- Fi + * Alliance (September 1, 2004) is incorporated by reference herein. + * The inclusion of the WMM Parameters in probe responses and + * association responses is mandatory for WMM enabled networks. The + * inclusion of the WMM Parameters in beacons, however, is optional. + */ + if (elems.wmm_param && (!bss->wmm_ie || bss->wmm_ie_len != elems.wmm_param_len || memcmp(bss->wmm_ie, elems.wmm_param, elems.wmm_param_len))) { @@ -2673,30 +2714,6 @@ static void ieee80211_rx_bss_info(struct net_device *dev, bss->wmm_ie = NULL; bss->wmm_ie_len = 0; } - if (elems.ht_cap_elem && - (!bss->ht_ie || bss->ht_ie_len != elems.ht_cap_elem_len || - memcmp(bss->ht_ie, elems.ht_cap_elem, elems.ht_cap_elem_len))) { - kfree(bss->ht_ie); - bss->ht_ie = kmalloc(elems.ht_cap_elem_len + 2, GFP_ATOMIC); - if (bss->ht_ie) { - memcpy(bss->ht_ie, elems.ht_cap_elem - 2, - elems.ht_cap_elem_len + 2); - bss->ht_ie_len = elems.ht_cap_elem_len + 2; - } else - bss->ht_ie_len = 0; - } else if (!elems.ht_cap_elem && bss->ht_ie) { - kfree(bss->ht_ie); - bss->ht_ie = NULL; - bss->ht_ie_len = 0; - } - - bss->timestamp = beacon_timestamp; - bss->last_update = jiffies; - bss->rssi = rx_status->ssi; - bss->signal = rx_status->signal; - bss->noise = rx_status->noise; - if (!beacon) - bss->probe_resp++; /* check if we need to merge IBSS */ if (sdata->vif.type == IEEE80211_IF_TYPE_IBSS && beacon && -- 2.39.5