Return-path: Received: from youngberry.canonical.com ([91.189.89.112]:43075 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753048Ab3A2Xru (ORCPT ); Tue, 29 Jan 2013 18:47:50 -0500 From: Seth Forshee To: Johannes Berg , linux-wireless@vger.kernel.org Cc: Seth Forshee , "John W. Linville" , Stanislaw Gruszka Subject: [PATCH 3/7] mac80211: Improve error handling for off-channel operation Date: Tue, 29 Jan 2013 17:47:31 -0600 Message-Id: <1359503255-18270-4-git-send-email-seth.forshee@canonical.com> (sfid-20130130_004755_536086_AAD54B71) In-Reply-To: <1359503255-18270-1-git-send-email-seth.forshee@canonical.com> References: <1359503255-18270-1-git-send-email-seth.forshee@canonical.com> Sender: linux-wireless-owner@vger.kernel.org List-ID: Errors in sending nullfunc or probe request frames during off-channel operation may have undesirable consequences, e.g. failure to set powersave at the AP. Add error handling for failures to transmit these frames. In the case of a nullfunc failure, fail to go off-channel and return an error to userspace. In the case of a failed probe request, abort the scan. Signed-off-by: Seth Forshee --- net/mac80211/ieee80211_i.h | 6 +++--- net/mac80211/mlme.c | 6 +++--- net/mac80211/offchannel.c | 24 ++++++++++++++++++------ net/mac80211/scan.c | 41 ++++++++++++++++++++++++++++------------- net/mac80211/util.c | 12 ++++++++---- 5 files changed, 60 insertions(+), 29 deletions(-) diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h index 8374763..c062d20 100644 --- a/net/mac80211/ieee80211_i.h +++ b/net/mac80211/ieee80211_i.h @@ -1369,7 +1369,7 @@ int ieee80211_request_sched_scan_stop(struct ieee80211_sub_if_data *sdata); void ieee80211_sched_scan_stopped_work(struct work_struct *work); /* off-channel helpers */ -void ieee80211_offchannel_stop_vifs(struct ieee80211_local *local); +bool ieee80211_offchannel_stop_vifs(struct ieee80211_local *local); void ieee80211_offchannel_return(struct ieee80211_local *local); void ieee80211_roc_setup(struct ieee80211_local *local); void ieee80211_start_next_roc(struct ieee80211_local *local); @@ -1582,7 +1582,7 @@ u32 ieee80211_mandatory_rates(struct ieee80211_local *local, void ieee80211_dynamic_ps_enable_work(struct work_struct *work); void ieee80211_dynamic_ps_disable_work(struct work_struct *work); void ieee80211_dynamic_ps_timer(unsigned long data); -void ieee80211_send_nullfunc(struct ieee80211_local *local, +bool ieee80211_send_nullfunc(struct ieee80211_local *local, struct ieee80211_sub_if_data *sdata, int powersave); void ieee80211_sta_rx_notify(struct ieee80211_sub_if_data *sdata, @@ -1627,7 +1627,7 @@ struct sk_buff *ieee80211_build_probe_req(struct ieee80211_sub_if_data *sdata, const u8 *ssid, size_t ssid_len, const u8 *ie, size_t ie_len, bool directed); -void ieee80211_send_probe_req(struct ieee80211_sub_if_data *sdata, u8 *dst, +bool ieee80211_send_probe_req(struct ieee80211_sub_if_data *sdata, u8 *dst, const u8 *ssid, size_t ssid_len, const u8 *ie, size_t ie_len, u32 ratemask, bool directed, bool no_cck, diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c index 6757ee2..7211344 100644 --- a/net/mac80211/mlme.c +++ b/net/mac80211/mlme.c @@ -664,7 +664,7 @@ void ieee80211_send_pspoll(struct ieee80211_local *local, ieee80211_tx_skb(sdata, skb); } -void ieee80211_send_nullfunc(struct ieee80211_local *local, +bool ieee80211_send_nullfunc(struct ieee80211_local *local, struct ieee80211_sub_if_data *sdata, int powersave) { @@ -674,7 +674,7 @@ void ieee80211_send_nullfunc(struct ieee80211_local *local, skb = ieee80211_nullfunc_get(&local->hw, &sdata->vif); if (!skb) - return; + return false; nullfunc = (struct ieee80211_hdr_3addr *) skb->data; if (powersave) @@ -685,7 +685,7 @@ void ieee80211_send_nullfunc(struct ieee80211_local *local, IEEE80211_STA_CONNECTION_POLL)) IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_CTL_USE_MINRATE; - ieee80211_tx_skb_offchannel(sdata, skb); + return ieee80211_tx_skb_offchannel(sdata, skb) == IEEE80211_TX_OK; } static void ieee80211_send_4addr_nullfunc(struct ieee80211_local *local, diff --git a/net/mac80211/offchannel.c b/net/mac80211/offchannel.c index 5b9b3b8..650af94 100644 --- a/net/mac80211/offchannel.c +++ b/net/mac80211/offchannel.c @@ -24,10 +24,11 @@ * because we *may* be doing work on-operating channel, and want our * hardware unconditionally awake, but still let the AP send us normal frames. */ -static void ieee80211_offchannel_ps_enable(struct ieee80211_sub_if_data *sdata) +static bool ieee80211_offchannel_ps_enable(struct ieee80211_sub_if_data *sdata) { struct ieee80211_local *local = sdata->local; struct ieee80211_if_managed *ifmgd = &sdata->u.mgd; + bool ret = true; local->offchannel_ps_enabled = false; @@ -57,7 +58,9 @@ static void ieee80211_offchannel_ps_enable(struct ieee80211_sub_if_data *sdata) * to send a new nullfunc frame to inform the AP that we * are again sleeping. */ - ieee80211_send_nullfunc(local, sdata, 1); + ret = ieee80211_send_nullfunc(local, sdata, 1); + + return ret; } /* inform AP that we are awake again, unless power save is enabled */ @@ -102,12 +105,13 @@ static void ieee80211_offchannel_ps_disable(struct ieee80211_sub_if_data *sdata) ieee80211_sta_reset_conn_monitor(sdata); } -void ieee80211_offchannel_stop_vifs(struct ieee80211_local *local) +bool ieee80211_offchannel_stop_vifs(struct ieee80211_local *local) { struct ieee80211_sub_if_data *sdata; + bool ret = true; if (WARN_ON(local->use_chanctx)) - return; + return false; /* * notify the AP about us leaving the channel and stop all @@ -138,10 +142,18 @@ void ieee80211_offchannel_stop_vifs(struct ieee80211_local *local) } if (sdata->vif.type == NL80211_IFTYPE_STATION && - sdata->u.mgd.associated) - ieee80211_offchannel_ps_enable(sdata); + sdata->u.mgd.associated) { + ret = ieee80211_offchannel_ps_enable(sdata); + if (!ret) + break; + } } mutex_unlock(&local->iflist_mtx); + + /* Attempt to recover if failed */ + if (!ret) + ieee80211_offchannel_return(local); + return ret; } void ieee80211_offchannel_return(struct ieee80211_local *local) diff --git a/net/mac80211/scan.c b/net/mac80211/scan.c index 607684c..894c95e 100644 --- a/net/mac80211/scan.c +++ b/net/mac80211/scan.c @@ -340,7 +340,8 @@ static int ieee80211_start_sw_scan(struct ieee80211_local *local) local->next_scan_state = SCAN_DECISION; local->scan_channel_idx = 0; - ieee80211_offchannel_stop_vifs(local); + if (!ieee80211_offchannel_stop_vifs(local)) + goto error; ieee80211_configure_filter(local); @@ -351,6 +352,10 @@ static int ieee80211_start_sw_scan(struct ieee80211_local *local) &local->scan_work, 0); return 0; + +error: + drv_sw_scan_complete(local); + return -EBUSY; } static bool ieee80211_can_scan(struct ieee80211_local *local, @@ -390,26 +395,32 @@ static void ieee80211_scan_state_send_probe(struct ieee80211_local *local, int i; struct ieee80211_sub_if_data *sdata; enum ieee80211_band band = local->hw.conf.channel->band; + bool success = true; sdata = rcu_dereference_protected(local->scan_sdata, lockdep_is_held(&local->mtx)); - for (i = 0; i < local->scan_req->n_ssids; i++) - ieee80211_send_probe_req( - sdata, NULL, - local->scan_req->ssids[i].ssid, - local->scan_req->ssids[i].ssid_len, - local->scan_req->ie, local->scan_req->ie_len, - local->scan_req->rates[band], false, - local->scan_req->no_cck, - local->hw.conf.channel, true); + for (i = 0; success && i < local->scan_req->n_ssids; i++) + success = ieee80211_send_probe_req( + sdata, NULL, + local->scan_req->ssids[i].ssid, + local->scan_req->ssids[i].ssid_len, + local->scan_req->ie, local->scan_req->ie_len, + local->scan_req->rates[band], false, + local->scan_req->no_cck, + local->hw.conf.channel, true); /* * After sending probe requests, wait for probe responses * on the channel. */ - *next_delay = IEEE80211_CHANNEL_TIME; - local->next_scan_state = SCAN_DECISION; + if (success) { + *next_delay = IEEE80211_CHANNEL_TIME; + local->next_scan_state = SCAN_DECISION; + } else { + *next_delay = 0; + local->next_scan_state = SCAN_ABORT; + } } static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata, @@ -688,7 +699,11 @@ static void ieee80211_scan_state_suspend(struct ieee80211_local *local, static void ieee80211_scan_state_resume(struct ieee80211_local *local, unsigned long *next_delay) { - ieee80211_offchannel_stop_vifs(local); + if (!ieee80211_offchannel_stop_vifs(local)) { + *next_delay = 0; + local->next_scan_state = SCAN_ABORT; + return; + } if (local->ops->flush) { drv_flush(local, false); diff --git a/net/mac80211/util.c b/net/mac80211/util.c index 5259557..0923892 100644 --- a/net/mac80211/util.c +++ b/net/mac80211/util.c @@ -1274,13 +1274,14 @@ struct sk_buff *ieee80211_build_probe_req(struct ieee80211_sub_if_data *sdata, return skb; } -void ieee80211_send_probe_req(struct ieee80211_sub_if_data *sdata, u8 *dst, +bool ieee80211_send_probe_req(struct ieee80211_sub_if_data *sdata, u8 *dst, const u8 *ssid, size_t ssid_len, const u8 *ie, size_t ie_len, u32 ratemask, bool directed, bool no_cck, struct ieee80211_channel *channel, bool scan) { struct sk_buff *skb; + enum ieee80211_tx_status tx_stat = IEEE80211_TX_DROPPED; skb = ieee80211_build_probe_req(sdata, dst, ratemask, channel, ssid, ssid_len, @@ -1290,11 +1291,14 @@ void ieee80211_send_probe_req(struct ieee80211_sub_if_data *sdata, u8 *dst, IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_CTL_NO_CCK_RATE; if (scan) - ieee80211_tx_skb_tid_band(sdata, skb, 7, - channel->band, true); + tx_stat = ieee80211_tx_skb_tid_band(sdata, skb, 7, + channel->band, + true); else - ieee80211_tx_skb(sdata, skb); + tx_stat = ieee80211_tx_skb(sdata, skb); } + + return tx_stat != IEEE80211_TX_DROPPED; } u32 ieee80211_sta_get_rates(struct ieee80211_local *local, -- 1.7.9.5