Return-path: Received: from contumacia.investici.org ([178.255.144.35]:63715 "EHLO contumacia.investici.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753995Ab2JPGkA (ORCPT ); Tue, 16 Oct 2012 02:40:00 -0400 From: Antonio Quartulli To: Johannes Berg Cc: "John W. Linville" , linux-wireless@vger.kernel.org, Antonio Quartulli Subject: [PATCHv3] nl/cfg80211: force scan using an AP vif if requested Date: Tue, 16 Oct 2012 08:39:22 +0200 Message-Id: <1350369562-24733-1-git-send-email-ordex@autistici.org> (sfid-20121016_084006_252788_97662999) Sender: linux-wireless-owner@vger.kernel.org List-ID: If the user wants to scan using a vif configured as AP, cfg80211 must give him a chance to do it, even if this will disrupt the stations performance due to off-channel scanning. To do so, this patch adds a 'force' flag to the SCAN_TRIGGER command which tells cfg80211 to perform the scanning operation even if the vif is an AP and the beaconing has already started. Signed-off-by: Antonio Quartulli --- v2: - Rebased on latest mac80211-next/master v3: - Introduced nl80211_feature flag to advertise this feature to the userspace and to allow drivers to do not support it include/linux/nl80211.h | 8 ++++++++ net/mac80211/cfg.c | 11 ++++++++++- net/mac80211/main.c | 4 +++- 3 files changed, 21 insertions(+), 2 deletions(-) diff --git a/include/linux/nl80211.h b/include/linux/nl80211.h index 0e6277a..617d0fb 100644 --- a/include/linux/nl80211.h +++ b/include/linux/nl80211.h @@ -3050,6 +3050,7 @@ enum nl80211_ap_sme_features { * mode * @NL80211_FEATURE_LOW_PRIORITY_SCAN: This driver supports low priority scan * @NL80211_FEATURE_SCAN_FLUSH: Scan flush is supported + * @NL80211_FEATURE_AP_SCAN: Support scanning using an AP vif */ enum nl80211_feature_flags { NL80211_FEATURE_SK_TX_STATUS = 1 << 0, @@ -3060,6 +3061,7 @@ enum nl80211_feature_flags { NL80211_FEATURE_SAE = 1 << 5, NL80211_FEATURE_LOW_PRIORITY_SCAN = 1 << 6, NL80211_FEATURE_SCAN_FLUSH = 1 << 7, + NL80211_FEATURE_AP_SCAN = 1 << 8, }; /** @@ -3103,10 +3105,16 @@ enum nl80211_connect_failed_reason { * * @NL80211_SCAN_FLAG_LOW_PRIORITY: scan request has low priority * @NL80211_SCAN_FLAG_FLUSH: flush cache before scanning + * @NL80211_SCAN_FLAG_AP: force a scan even if the interface is configured + * as AP and the beaconing has already been configured. This attribute is + * dangerous because will destroy stations performance as a lot of frames + * will be lost while scanning off-channel, therefore it must be used only + * when really needed */ enum nl80211_scan_flags { NL80211_SCAN_FLAG_LOW_PRIORITY = 1<<0, NL80211_SCAN_FLAG_FLUSH = 1<<1, + NL80211_SCAN_FLAG_AP = 1<<2, }; #endif /* __LINUX_NL80211_H */ diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c index ed27988..c45c62e 100644 --- a/net/mac80211/cfg.c +++ b/net/mac80211/cfg.c @@ -1855,7 +1855,16 @@ static int ieee80211_scan(struct wiphy *wiphy, * beaconing hasn't been configured yet */ case NL80211_IFTYPE_AP: - if (sdata->u.ap.beacon) + /* + * If the scan has been forced (and the driver supports + * forcing), don't care about being beaconing already. + * This will create problems to the attached stations (e.g. all + * the frames sent while scanning on other channel will be + * lost) + */ + if (sdata->u.ap.beacon && + (!(wiphy->features & NL80211_FEATURE_AP_SCAN) || + !(req->flags & NL80211_SCAN_FLAG_AP))) return -EOPNOTSUPP; break; default: diff --git a/net/mac80211/main.c b/net/mac80211/main.c index ba5a232..c42094b 100644 --- a/net/mac80211/main.c +++ b/net/mac80211/main.c @@ -603,7 +603,9 @@ struct ieee80211_hw *ieee80211_alloc_hw(size_t priv_data_len, NL80211_FEATURE_HT_IBSS; if (!ops->hw_scan) - wiphy->features |= NL80211_FEATURE_LOW_PRIORITY_SCAN; + wiphy->features |= NL80211_FEATURE_LOW_PRIORITY_SCAN | + NL80211_FEATURE_AP_SCAN; + if (!ops->set_key) wiphy->flags |= WIPHY_FLAG_IBSS_RSN; -- 1.7.12.3