From 36d16ae73becc5978fe22866e9ab66b509211afe Mon Sep 17 00:00:00 2001 From: Helmut Schaa Date: Thu, 8 May 2008 13:34:07 +0200 Subject: [PATCH] mac80211: fix association with some APs Some APs refuse association if the supported rates contained in the association request do not match its own supported rates. This patch introduces a new function which builds the intersection between the AP's supported rates and the client's supported rates to work around such problems. The same approach is already used in ipw2200 for example. Signed-off-by: Helmut Schaa Signed-off-by: John W. Linville --- net/mac80211/mlme.c | 68 ++++++++++++++++++++++++++++++++++----------- 1 file changed, 52 insertions(+), 16 deletions(-) diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c index a5e5c31c23ab..4adba09e80ca 100644 --- a/net/mac80211/mlme.c +++ b/net/mac80211/mlme.c @@ -665,6 +665,26 @@ static void ieee80211_authenticate(struct net_device *dev, mod_timer(&ifsta->timer, jiffies + IEEE80211_AUTH_TIMEOUT); } +static int ieee80211_compatible_rates(struct ieee80211_sta_bss *bss, + struct ieee80211_supported_band *sband, + u64 *rates) +{ + int i, j, count; + *rates = 0; + count = 0; + for (i = 0; i < bss->supp_rates_len; i++) { + int rate = (bss->supp_rates[i] & 0x7F) * 5; + + for (j = 0; j < sband->n_bitrates; j++) + if (sband->bitrates[j].bitrate == rate) { + *rates |= BIT(j); + count++; + break; + } + } + + return count; +} static void ieee80211_send_assoc(struct net_device *dev, struct ieee80211_if_sta *ifsta) @@ -673,11 +693,12 @@ static void ieee80211_send_assoc(struct net_device *dev, struct sk_buff *skb; struct ieee80211_mgmt *mgmt; u8 *pos, *ies; - int i, len; + int i, len, count, rates_len, supp_rates_len; u16 capab; struct ieee80211_sta_bss *bss; int wmm = 0; struct ieee80211_supported_band *sband; + u64 rates = 0; skb = dev_alloc_skb(local->hw.extra_tx_headroom + sizeof(*mgmt) + 200 + ifsta->extra_ie_len + @@ -740,24 +761,39 @@ static void ieee80211_send_assoc(struct net_device *dev, *pos++ = ifsta->ssid_len; memcpy(pos, ifsta->ssid, ifsta->ssid_len); - len = sband->n_bitrates; - if (len > 8) - len = 8; - pos = skb_put(skb, len + 2); - *pos++ = WLAN_EID_SUPP_RATES; - *pos++ = len; - for (i = 0; i < len; i++) { - int rate = sband->bitrates[i].bitrate; - *pos++ = (u8) (rate / 5); - } + /* all supported rates should be added here but some APs + * (e.g. D-Link DAP 1353 in b-only mode) don't like that + * Therefore only add rates the AP supports */ + rates_len = ieee80211_compatible_rates(bss, sband, &rates); + supp_rates_len = rates_len; + if (supp_rates_len > 8) + supp_rates_len = 8; - if (sband->n_bitrates > len) { - pos = skb_put(skb, sband->n_bitrates - len + 2); - *pos++ = WLAN_EID_EXT_SUPP_RATES; - *pos++ = sband->n_bitrates - len; - for (i = len; i < sband->n_bitrates; i++) { + len = sband->n_bitrates; + pos = skb_put(skb, supp_rates_len + 2); + *pos++ = WLAN_EID_SUPP_RATES; + *pos++ = supp_rates_len; + + count = 0; + for (i = 0; i < sband->n_bitrates; i++) { + if (BIT(i) & rates) { int rate = sband->bitrates[i].bitrate; *pos++ = (u8) (rate / 5); + if (++count == 8) + break; + } + } + + if (count == 8) { + pos = skb_put(skb, rates_len - count + 2); + *pos++ = WLAN_EID_EXT_SUPP_RATES; + *pos++ = rates_len - count; + + for (i++; i < sband->n_bitrates; i++) { + if (BIT(i) & rates) { + int rate = sband->bitrates[i].bitrate; + *pos++ = (u8) (rate / 5); + } } }