hostapd: Wait for channel list update after country code change

If hostapd is requested to set the country code and the previous country
code differs from the new one, the channel list information from the
driver may change. This change may not be instant, so wait for an
EVENT_CHANNEL_LIST_CHANGED event before continuing interface setup with
fetching of the channel list information. This fixes issues where the
selected channel is not available based on the previous regulatory data
and update through CRDA takes some time.

Signed-hostap: Jouni Malinen <j@w1.fi>

diff --git a/src/ap/ap_drv_ops.h b/src/ap/ap_drv_ops.h
index 5defd8b384e0dade0637ce196d7e06dd1bb7903a..024339ab8482c37df5cb9b0fe1afaf8581bfe451 100644 (file)
--- a/src/ap/ap_drv_ops.h
+++ b/src/ap/ap_drv_ops.h
@@ -242,4 +242,11 @@ static inline int hostapd_drv_get_survey(struct hostapd_data *hapd,
        return hapd->driver->get_survey(hapd->drv_priv, freq);
 }
 
+static inline int hostapd_get_country(struct hostapd_data *hapd, char *alpha2)
+{
+       if (hapd->driver == NULL || hapd->driver->get_country == NULL)
+               return -1;
+       return hapd->driver->get_country(hapd->drv_priv, alpha2);
+}
+
 #endif /* AP_DRV_OPS */

diff --git a/src/ap/drv_callbacks.c b/src/ap/drv_callbacks.c
index b30da145ed81a1aac1f5d03e716eec878bc7ca4b..d0a429d78a26a3d2f5515178c91eaea96921b3ce 100644 (file)
--- a/src/ap/drv_callbacks.c
+++ b/src/ap/drv_callbacks.c
@@ -1007,6 +1007,7 @@ void wpa_supplicant_event(void *ctx, enum wpa_event_type event,
                /* TODO: check this. hostapd_get_hw_features() initializes
                 * too much stuff. */
                /* hostapd_get_hw_features(hapd->iface); */
+               hostapd_channel_list_updated(hapd->iface);
                break;
 #endif /* NEED_AP_MLME */
        default:

diff --git a/src/ap/hostapd.c b/src/ap/hostapd.c
index d16c36d0d1c2459939d3c66f4fad7784d4bff7e8..f41cb145b82ac8e218728c4ba1e0b7eaee58c191 100644 (file)
--- a/src/ap/hostapd.c
+++ b/src/ap/hostapd.c
@@ -38,6 +38,8 @@
 static int hostapd_flush_old_stations(struct hostapd_data *hapd, u16 reason);
 static int hostapd_setup_encryption(char *iface, struct hostapd_data *hapd);
 static int hostapd_broadcast_wep_clear(struct hostapd_data *hapd);
+static int setup_interface2(struct hostapd_iface *iface);
+static void channel_list_update_timeout(void *eloop_ctx, void *timeout_ctx);
 
 extern int wpa_debug_level;
 extern struct wpa_driver_ops *wpa_drivers[];
@@ -337,6 +339,8 @@ static void hostapd_cleanup_iface_partial(struct hostapd_iface *iface)
  */
 static void hostapd_cleanup_iface(struct hostapd_iface *iface)
 {
+       eloop_cancel_timeout(channel_list_update_timeout, iface, NULL);
+
        hostapd_cleanup_iface_partial(iface);
        hostapd_config_free(iface->conf);
        iface->conf = NULL;
@@ -926,11 +930,39 @@ static int start_ctrl_iface(struct hostapd_iface *iface)
 }
 
 
+static void channel_list_update_timeout(void *eloop_ctx, void *timeout_ctx)
+{
+       struct hostapd_iface *iface = eloop_ctx;
+
+       if (!iface->wait_channel_update) {
+               wpa_printf(MSG_INFO, "Channel list update timeout, but interface was not waiting for it");
+               return;
+       }
+
+       /*
+        * It is possible that the existing channel list is acceptable, so try
+        * to proceed.
+        */
+       wpa_printf(MSG_DEBUG, "Channel list update timeout - try to continue anyway");
+       setup_interface2(iface);
+}
+
+
+void hostapd_channel_list_updated(struct hostapd_iface *iface)
+{
+       if (!iface->wait_channel_update)
+               return;
+
+       wpa_printf(MSG_DEBUG, "Channel list updated - continue setup");
+       eloop_cancel_timeout(channel_list_update_timeout, iface, NULL);
+       setup_interface2(iface);
+}
+
+
 static int setup_interface(struct hostapd_iface *iface)
 {
        struct hostapd_data *hapd = iface->bss[0];
        size_t i;
-       char country[4];
 
        /*
         * Make sure that all BSSes get configured with a pointer to the same
@@ -953,14 +985,39 @@ static int setup_interface(struct hostapd_iface *iface)
                return -1;
 
        if (hapd->iconf->country[0] && hapd->iconf->country[1]) {
+               char country[4], previous_country[4];
+
+               if (hostapd_get_country(hapd, previous_country) < 0)
+                       previous_country[0] = '\0';
+
                os_memcpy(country, hapd->iconf->country, 3);
                country[3] = '\0';
                if (hostapd_set_country(hapd, country) < 0) {
                        wpa_printf(MSG_ERROR, "Failed to set country code");
                        return -1;
                }
+
+               wpa_printf(MSG_DEBUG, "Previous country code %s, new country code %s",
+                          previous_country, country);
+
+               if (os_strncmp(previous_country, country, 2) != 0) {
+                       wpa_printf(MSG_DEBUG, "Continue interface setup after channel list update");
+                       iface->wait_channel_update = 1;
+                       eloop_register_timeout(1, 0,
+                                              channel_list_update_timeout,
+                                              iface, NULL);
+                       return 0;
+               }
        }
 
+       return setup_interface2(iface);
+}
+
+
+static int setup_interface2(struct hostapd_iface *iface)
+{
+       iface->wait_channel_update = 0;
+
        if (hostapd_get_hw_features(iface)) {
                /* Not all drivers support this yet, so continue without hw
                 * feature data. */
@@ -1171,6 +1228,9 @@ void hostapd_interface_deinit(struct hostapd_iface *iface)
        if (iface == NULL)
                return;
 
+       eloop_cancel_timeout(channel_list_update_timeout, iface, NULL);
+       iface->wait_channel_update = 0;
+
        hostapd_cleanup_iface_pre(iface);
        for (j = iface->num_bss - 1; j >= 0; j--) {
                struct hostapd_data *hapd = iface->bss[j];

diff --git a/src/ap/hostapd.h b/src/ap/hostapd.h
index ce2516ebbe06a611d0935a03783407bc8b083d80..dacdfa7da1b92d4323f03fe0e1a410f3014e9aec 100644 (file)
--- a/src/ap/hostapd.h
+++ b/src/ap/hostapd.h
@@ -254,6 +254,8 @@ struct hostapd_iface {
        size_t num_bss;
        struct hostapd_data **bss;
 
+       unsigned int wait_channel_update:1;
+
        int num_ap; /* number of entries in ap_list */
        struct ap_info *ap_list; /* AP info list head */
        struct ap_info *ap_hash[STA_HASH_SIZE];
@@ -361,6 +363,7 @@ int hostapd_reload_iface(struct hostapd_iface *hapd_iface);
 int hostapd_disable_iface(struct hostapd_iface *hapd_iface);
 int hostapd_add_iface(struct hapd_interfaces *ifaces, char *buf);
 int hostapd_remove_iface(struct hapd_interfaces *ifaces, char *buf);
+void hostapd_channel_list_updated(struct hostapd_iface *iface);
 
 /* utils.c */
 int hostapd_register_probereq_cb(struct hostapd_data *hapd,

diff --git a/src/drivers/driver.h b/src/drivers/driver.h
index 85f66ee41c7731dc172e1a0b609b2a76e8fedd3a..f233032ebbf3d426a615ef8a44874556a1b9b5c6 100644 (file)
--- a/src/drivers/driver.h
+++ b/src/drivers/driver.h
@@ -1569,6 +1569,14 @@ struct wpa_driver_ops {
         */
        int (*set_country)(void *priv, const char *alpha2);
 
+       /**
+        * get_country - Get country
+        * @priv: Private driver interface data
+        * @alpha2: Buffer for returning country code (at least 3 octets)
+        * Returns: 0 on success, -1 on failure
+        */
+       int (*get_country)(void *priv, char *alpha2);
+
        /**
         * global_init - Global driver initialization
         * Returns: Pointer to private data (global), %NULL on failure

diff --git a/src/drivers/driver_nl80211.c b/src/drivers/driver_nl80211.c
index 8bd0759639223ae38b321d925d8d9df4e288a20d..4dffb3eb00e8890adae414cfb1d5c554247aeb97 100644 (file)
--- a/src/drivers/driver_nl80211.c
+++ b/src/drivers/driver_nl80211.c
@@ -2934,6 +2934,44 @@ nla_put_failure:
 }
 
 
+static int nl80211_get_country(struct nl_msg *msg, void *arg)
+{
+       char *alpha2 = arg;
+       struct nlattr *tb_msg[NL80211_ATTR_MAX + 1];
+       struct genlmsghdr *gnlh = nlmsg_data(nlmsg_hdr(msg));
+
+       nla_parse(tb_msg, NL80211_ATTR_MAX, genlmsg_attrdata(gnlh, 0),
+                 genlmsg_attrlen(gnlh, 0), NULL);
+       if (!tb_msg[NL80211_ATTR_REG_ALPHA2]) {
+               wpa_printf(MSG_DEBUG, "nl80211: No country information available");
+               return NL_SKIP;
+       }
+       os_strlcpy(alpha2, nla_data(tb_msg[NL80211_ATTR_REG_ALPHA2]), 3);
+       return NL_SKIP;
+}
+
+
+static int wpa_driver_nl80211_get_country(void *priv, char *alpha2)
+{
+       struct i802_bss *bss = priv;
+       struct wpa_driver_nl80211_data *drv = bss->drv;
+       struct nl_msg *msg;
+       int ret;
+
+       msg = nlmsg_alloc();
+       if (!msg)
+               return -ENOMEM;
+
+       nl80211_cmd(drv, msg, 0, NL80211_CMD_GET_REG);
+       alpha2[0] = '\0';
+       ret = send_and_recv_msgs(drv, msg, nl80211_get_country, alpha2);
+       if (!alpha2[0])
+               ret = -1;
+
+       return ret;
+}
+
+
 static int protocol_feature_handler(struct nl_msg *msg, void *arg)
 {
        u32 *feat = arg;
@@ -11204,6 +11242,7 @@ const struct wpa_driver_ops wpa_driver_nl80211_ops = {
        .set_operstate = wpa_driver_nl80211_set_operstate,
        .set_supp_port = wpa_driver_nl80211_set_supp_port,
        .set_country = wpa_driver_nl80211_set_country,
+       .get_country = wpa_driver_nl80211_get_country,
        .set_ap = wpa_driver_nl80211_set_ap,
        .set_acl = wpa_driver_nl80211_set_acl,
        .if_add = wpa_driver_nl80211_if_add,