From 73afc20d409652b89cbc2f5e3cf8583d6bf4dcaa Mon Sep 17 00:00:00 2001 From: Andrei Otcheretianski Date: Tue, 8 Sep 2015 12:46:16 +0300 Subject: [PATCH] P2P: Implement wpas_p2p_move_go_csa() Use channel switch mechanism to move a P2P GO to a new channel, when required. In order to be able to reconfigure the GO channel, split wpa_supplicant_conf_ap() function, so the frequency configuration part can be reused to find additional CSA settings. Signed-off-by: Andrei Otcheretianski --- wpa_supplicant/ap.c | 26 ++++--- wpa_supplicant/ap.h | 6 +- wpa_supplicant/p2p_supplicant.c | 116 +++++++++++++++++++++++++++++++- 3 files changed, 131 insertions(+), 17 deletions(-) diff --git a/wpa_supplicant/ap.c b/wpa_supplicant/ap.c index 7a4f4cf4f..26ac70363 100644 --- a/wpa_supplicant/ap.c +++ b/wpa_supplicant/ap.c @@ -76,10 +76,19 @@ no_vht: #endif /* CONFIG_IEEE80211N */ -void wpa_supplicant_conf_ap_ht(struct wpa_supplicant *wpa_s, - struct wpa_ssid *ssid, - struct hostapd_config *conf) +int wpa_supplicant_conf_ap_ht(struct wpa_supplicant *wpa_s, + struct wpa_ssid *ssid, + struct hostapd_config *conf) { + conf->hw_mode = ieee80211_freq_to_chan(ssid->frequency, + &conf->channel); + + if (conf->hw_mode == NUM_HOSTAPD_MODES) { + wpa_printf(MSG_ERROR, "Unsupported AP mode frequency: %d MHz", + ssid->frequency); + return -1; + } + /* TODO: enable HT40 if driver supports it; * drop to 11b if driver does not support 11g */ @@ -166,6 +175,8 @@ void wpa_supplicant_conf_ap_ht(struct wpa_supplicant *wpa_s, } } #endif /* CONFIG_IEEE80211N */ + + return 0; } @@ -179,15 +190,8 @@ static int wpa_supplicant_conf_ap(struct wpa_supplicant *wpa_s, os_strlcpy(bss->iface, wpa_s->ifname, sizeof(bss->iface)); - conf->hw_mode = ieee80211_freq_to_chan(ssid->frequency, - &conf->channel); - if (conf->hw_mode == NUM_HOSTAPD_MODES) { - wpa_printf(MSG_ERROR, "Unsupported AP mode frequency: %d MHz", - ssid->frequency); + if (wpa_supplicant_conf_ap_ht(wpa_s, ssid, conf)) return -1; - } - - wpa_supplicant_conf_ap_ht(wpa_s, ssid, conf); if (ieee80211_is_dfs(ssid->frequency) && wpa_s->conf->country[0]) { conf->ieee80211h = 1; diff --git a/wpa_supplicant/ap.h b/wpa_supplicant/ap.h index 594168cf1..2b8a1d42c 100644 --- a/wpa_supplicant/ap.h +++ b/wpa_supplicant/ap.h @@ -76,9 +76,9 @@ int wpas_ap_wps_add_nfc_pw(struct wpa_supplicant *wpa_s, u16 pw_id, const struct wpabuf *pw, const u8 *pubkey_hash); struct hostapd_config; -void wpa_supplicant_conf_ap_ht(struct wpa_supplicant *wpa_s, - struct wpa_ssid *ssid, - struct hostapd_config *conf); +int wpa_supplicant_conf_ap_ht(struct wpa_supplicant *wpa_s, + struct wpa_ssid *ssid, + struct hostapd_config *conf); int wpas_ap_stop_ap(struct wpa_supplicant *wpa_s); diff --git a/wpa_supplicant/p2p_supplicant.c b/wpa_supplicant/p2p_supplicant.c index 78bdd0837..106388921 100644 --- a/wpa_supplicant/p2p_supplicant.c +++ b/wpa_supplicant/p2p_supplicant.c @@ -53,6 +53,13 @@ */ #define P2P_GO_FREQ_CHANGE_TIME 5 +/** + * Defines CSA parameters which are used when GO evacuates the no longer valid + * channel (and if the driver supports channel switch). + */ +#define P2P_GO_CSA_COUNT 7 +#define P2P_GO_CSA_BLOCK_TX 0 + #ifndef P2P_MAX_CLIENT_IDLE /* * How many seconds to try to reconnect to the GO when connection in P2P client @@ -8473,14 +8480,117 @@ static void wpas_p2p_optimize_listen_channel(struct wpa_supplicant *wpa_s, static int wpas_p2p_move_go_csa(struct wpa_supplicant *wpa_s) { + struct hostapd_config *conf; + struct p2p_go_neg_results params; + struct csa_settings csa_settings; + struct wpa_ssid *current_ssid = wpa_s->current_ssid; + int old_freq = current_ssid->frequency; + int ret; + u8 chan; + if (!(wpa_s->drv_flags & WPA_DRIVER_FLAGS_AP_CSA)) { wpa_dbg(wpa_s, MSG_DEBUG, "CSA is not enabled"); return -1; } - /* TODO: Add CSA support */ - wpa_dbg(wpa_s, MSG_DEBUG, "Moving GO with CSA is not implemented"); - return -1; + /* + * TODO: This function may not always work correctly. For example, + * when we have a running GO and a BSS on a DFS channel. + */ + if (wpas_p2p_init_go_params(wpa_s, ¶ms, 0, 0, 0, NULL)) { + wpa_dbg(wpa_s, MSG_DEBUG, + "P2P CSA: Failed to select new frequency for GO"); + return -1; + } + + if (current_ssid->frequency == params.freq) { + wpa_dbg(wpa_s, MSG_DEBUG, + "P2P CSA: Selected same frequency - not moving GO"); + return 0; + } + + conf = hostapd_config_defaults(); + if (!conf) { + wpa_dbg(wpa_s, MSG_DEBUG, + "P2P CSA: Failed to allocate default config"); + return -1; + } + + current_ssid->frequency = params.freq; + if (wpa_supplicant_conf_ap_ht(wpa_s, current_ssid, conf)) { + wpa_dbg(wpa_s, MSG_DEBUG, + "P2P CSA: Failed to create new GO config"); + ret = -1; + goto out; + } + + if (conf->hw_mode != wpa_s->ap_iface->current_mode->mode) { + wpa_dbg(wpa_s, MSG_DEBUG, + "P2P CSA: CSA to a different band is not supported"); + ret = -1; + goto out; + } + + os_memset(&csa_settings, 0, sizeof(csa_settings)); + csa_settings.cs_count = P2P_GO_CSA_COUNT; + csa_settings.block_tx = P2P_GO_CSA_BLOCK_TX; + csa_settings.freq_params.freq = params.freq; + + if (ieee80211_freq_to_channel_ext(params.freq, conf->secondary_channel, + conf->ieee80211ac, + &wpa_s->ap_iface->cs_oper_class, + &chan) == NUM_HOSTAPD_MODES) { + wpa_dbg(wpa_s, MSG_DEBUG, + "P2P CSA: Selected invalid frequency"); + ret = -1; + goto out; + } + + csa_settings.freq_params.channel = chan; + csa_settings.freq_params.sec_channel_offset = conf->secondary_channel; + csa_settings.freq_params.ht_enabled = conf->ieee80211n; + csa_settings.freq_params.bandwidth = conf->secondary_channel ? 40 : 20; + + if (conf->ieee80211ac) { + int freq1 = 0, freq2 = 0; + + if (conf->vht_oper_centr_freq_seg0_idx) + freq1 = ieee80211_chan_to_freq( + NULL, wpa_s->ap_iface->cs_oper_class, + conf->vht_oper_centr_freq_seg0_idx); + + if (conf->vht_oper_centr_freq_seg1_idx) + freq2 = ieee80211_chan_to_freq( + NULL, wpa_s->ap_iface->cs_oper_class, + conf->vht_oper_centr_freq_seg1_idx); + + if (freq1 < 0 || freq2 < 0) { + wpa_dbg(wpa_s, MSG_DEBUG, + "P2P CSA: Selected invalid VHT center freqs"); + ret = -1; + goto out; + } + + csa_settings.freq_params.vht_enabled = conf->ieee80211ac; + csa_settings.freq_params.center_freq1 = freq1; + csa_settings.freq_params.center_freq2 = freq2; + + switch (conf->vht_oper_chwidth) { + case VHT_CHANWIDTH_80MHZ: + case VHT_CHANWIDTH_80P80MHZ: + csa_settings.freq_params.bandwidth = 80; + break; + case VHT_CHANWIDTH_160MHZ: + csa_settings.freq_params.bandwidth = 160; + break; + } + } + + ret = ap_switch_channel(wpa_s, &csa_settings); +out: + current_ssid->frequency = old_freq; + hostapd_config_free(conf); + return ret; }