Return-path: Received: from mail022-1.exch022.serverdata.net ([64.78.22.98]:56958 "EHLO mail022-1.exch022.serverdata.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751055Ab3BDLBg (ORCPT ); Mon, 4 Feb 2013 06:01:36 -0500 Message-ID: <510F950C.6000103@posedge.com> (sfid-20130204_120140_605293_85A9B214) Date: Mon, 04 Feb 2013 16:31:32 +0530 From: Srinivasan B MIME-Version: 1.0 To: johannes@sipsolutions.net CC: linux-wireless@vger.kernel.org Subject: [RFC v1 ] hostapd: Beacon generation with Power Constraint IE - 11h TPC Content-Type: text/plain; charset=ISO-8859-1; format=flowed Sender: linux-wireless-owner@vger.kernel.org List-ID: This patch includes modifications in hostapd to generate beacons and probe response packets with Power Constraint IE. This patch is based on the initial design RFC proposed with subject "[RFC - v1 - design doc] hostapd: Beacon generation with Power Constraint IE - 11h TPC". Changes from the proposed design: ------------------------------------------------ Design document proposes to imply TPC only for devices operating in U-NII 2 band. As per further analysis of beacons transmitted by Netgear, CISCO APs and few other APs in 802.11A mode, the power constraint IE is also included in beacons transmitted in U-NII 1, U-NII 3 bands. Hence power constraint IE is included in all beacons/probe response packets for devices operating in 80211A mode (without restricting to U-NII 2 band) and with 80211h flag enabled in hostapd.config Signed-off-by: Srinivasan --- hostapd/config_file.c | 8 ++++++++ hostapd/hostapd.conf | 5 +++++ src/ap/ap_config.h | 3 +++ src/ap/beacon.c | 30 ++++++++++++++++++++++++++++++ src/ap/ieee802_11.c | 5 +++++ 5 files changed, 51 insertions(+), 0 deletions(-) diff --git a/hostapd/config_file.c b/hostapd/config_file.c index 7b22dfd..b6a3b6e 100644 --- a/hostapd/config_file.c +++ b/hostapd/config_file.c @@ -1224,6 +1224,12 @@ static int hostapd_config_check(struct hostapd_config *conf) return -1; } + if (conf->ieee80211h && !conf->ieee80211d) { + wpa_printf(MSG_ERROR, "Cannot enable IEEE 802.11h without " + "enabling 802.11d "); + return -1; + } + for (i = 0; i < conf->num_bss; i++) { if (hostapd_config_check_bss(&conf->bss[i], conf)) return -1; @@ -1785,6 +1791,8 @@ static int hostapd_config_fill(struct hostapd_config *conf, conf->country[2] = ' '; } else if (os_strcmp(buf, "ieee80211d") == 0) { conf->ieee80211d = atoi(pos); + } else if (os_strcmp(buf, "ieee80211h") == 0) { + conf->ieee80211h = atoi(pos); } else if (os_strcmp(buf, "ieee8021x") == 0) { bss->ieee802_1x = atoi(pos); } else if (os_strcmp(buf, "eapol_version") == 0) { diff --git a/hostapd/hostapd.conf b/hostapd/hostapd.conf index eca3996..759489f 100644 --- a/hostapd/hostapd.conf +++ b/hostapd/hostapd.conf @@ -105,6 +105,11 @@ ssid=test # (default: 0 = disabled) #ieee80211d=1 +# Enable IEEE 802.11h. This is a partial support for 802.11h which +# includes Power Constraint IE in beacon and prb response. +# (default: 0 = disabled) +#ieee80211h=1 + # Operation mode (a = IEEE 802.11a, b = IEEE 802.11b, g = IEEE 802.11g, # ad = IEEE 802.11ad (60 GHz); a/g options are used with IEEE 802.11n, too, to # specify band) diff --git a/src/ap/ap_config.h b/src/ap/ap_config.h index 4742107..a0624b9 100644 --- a/src/ap/ap_config.h +++ b/src/ap/ap_config.h @@ -460,6 +460,8 @@ struct hostapd_bss_config { int *sae_groups; }; +/* Default value for pwr constraint */ +#define DEFAULT_PWR_CONSTRAINT 0 /** * struct hostapd_config - Per-radio interface configuration @@ -495,6 +497,7 @@ struct hostapd_config { */ int ieee80211d; + int ieee80211h; struct hostapd_tx_queue_params tx_queue[NUM_TX_QUEUES]; diff --git a/src/ap/beacon.c b/src/ap/beacon.c index 4c47c75..9749d45 100644 --- a/src/ap/beacon.c +++ b/src/ap/beacon.c @@ -172,6 +172,30 @@ static u8 * hostapd_eid_country(struct hostapd_data *hapd, u8 *eid, return pos; } +static u8 * hostapd_eid_pwr_constraint(struct hostapd_data *hapd, u8 *eid) +{ + u8 *pos = eid; + + if (!hapd->iconf->ieee80211h || + hapd->iface->current_mode == NULL || + hapd->iface->current_mode->mode != HOSTAPD_MODE_IEEE80211A) + return eid; + + /* CRDA provides reduced TX power than actual regulatory max TX power. + * Value of 0 to the Local Power constraint provides an opportunity + * for the client devices to operate at Power Limit provided by CRDA + * (for client devices + * "Local max TX pwr" = regul max TX pwr - Local pwr constraint)*/ + + /* Element ID */ + *pos++ = WLAN_EID_PWR_CONSTRAINT; + /* Length */ + *pos++ = 1; + /* Local Power Constraint */ + *pos++ = DEFAULT_PWR_CONSTRAINT; + + return pos; +} static u8 * hostapd_eid_wpa(struct hostapd_data *hapd, u8 *eid, size_t len) { @@ -242,6 +266,9 @@ static u8 * hostapd_gen_probe_resp(struct hostapd_data *hapd, pos = hostapd_eid_country(hapd, pos, epos - pos); + /* Power Constraint element */ + pos = hostapd_eid_pwr_constraint(hapd, pos); + /* ERP Information element */ pos = hostapd_eid_erp_info(hapd, pos); @@ -631,6 +658,9 @@ void ieee802_11_set_beacon(struct hostapd_data *hapd) tailpos = hostapd_eid_country(hapd, tailpos, tail + BEACON_TAIL_BUF_SIZE - tailpos); + /* Power Constraint element */ + tailpos = hostapd_eid_pwr_constraint(hapd, tailpos); + /* ERP Information element */ tailpos = hostapd_eid_erp_info(hapd, tailpos); diff --git a/src/ap/ieee802_11.c b/src/ap/ieee802_11.c index 79235df..2a4f758 100644 --- a/src/ap/ieee802_11.c +++ b/src/ap/ieee802_11.c @@ -175,6 +175,11 @@ u16 hostapd_own_capab_info(struct hostapd_data *hapd, struct sta_info *sta, hapd->iface->num_sta_no_short_slot_time == 0) capab |= WLAN_CAPABILITY_SHORT_SLOT_TIME; + /* To Do: Also consider driver support for DFS to set Spectrum Mgmt*/ + if (hapd->iface->current_mode && + hapd->iface->current_mode->mode == HOSTAPD_MODE_IEEE80211A && + hapd->iconf->ieee80211h) + capab |= WLAN_CAPABILITY_SPECTRUM_MGMT; return capab; }