HS 2.0R2: Add support for Policy/MaximumBSSLoadValue

The new credential parameter max_bss_load can be used to specify
restrictions on BSS Load in the home network.

Signed-hostap: Jouni Malinen <jouni@qca.qualcomm.com>

diff --git a/wpa_supplicant/README-HS20 b/wpa_supplicant/README-HS20
index 57abdbf..c79b05e 100644 (file)
--- a/wpa_supplicant/README-HS20
+++ b/wpa_supplicant/README-HS20
@@ -237,6 +237,13 @@ Credentials can be pre-configured for automatic network selection:
 # min_dl_bandwidth_roaming
 # min_ul_bandwidth_roaming
 #
+# max_bss_load: Maximum BSS Load Channel Utilization (1..255)
+#      (PPS/<X+>/Policy/MaximumBSSLoadValue)
+#      This value is used as the maximum channel utilization for network
+#      selection purposes for home networks. If the AP does not advertise
+#      BSS Load or if the limit would prevent any connection, this constraint
+#      will be ignored.
+#
 # for example:
 #
 #cred={

diff --git a/wpa_supplicant/config.c b/wpa_supplicant/config.c
index ab7a680..f4a81aa 100644 (file)
--- a/wpa_supplicant/config.c
+++ b/wpa_supplicant/config.c
@@ -2473,6 +2473,11 @@ int wpa_config_set_cred(struct wpa_cred *cred, const char *var,
                return 0;
        }
 
+       if (os_strcmp(var, "max_bss_load") == 0) {
+               cred->max_bss_load = atoi(value);
+               return 0;
+       }
+
        val = wpa_config_parse_string(value, &len);
        if (val == NULL) {
                wpa_printf(MSG_ERROR, "Line %d: invalid field '%s' string "

diff --git a/wpa_supplicant/config.h b/wpa_supplicant/config.h
index b37a974..f2da234 100644 (file)
--- a/wpa_supplicant/config.h
+++ b/wpa_supplicant/config.h
@@ -256,6 +256,15 @@ struct wpa_cred {
        unsigned int min_ul_bandwidth_home;
        unsigned int min_dl_bandwidth_roaming;
        unsigned int min_ul_bandwidth_roaming;
+
+       /**
+        * max_bss_load - Maximum BSS Load Channel Utilization (1..255)
+        * This value is used as the maximum channel utilization for network
+        * selection purposes for home networks. If the AP does not advertise
+        * BSS Load or if the limit would prevent any connection, this
+        * constraint will be ignored.
+        */
+       unsigned int max_bss_load;
 };
 
 

diff --git a/wpa_supplicant/config_file.c b/wpa_supplicant/config_file.c
index e50c86a..53631b9 100644 (file)
--- a/wpa_supplicant/config_file.c
+++ b/wpa_supplicant/config_file.c
@@ -822,6 +822,10 @@ static void wpa_config_write_cred(FILE *f, struct wpa_cred *cred)
        if (cred->min_ul_bandwidth_roaming)
                fprintf(f, "\tmin_ul_bandwidth_roaming=%u\n",
                        cred->min_ul_bandwidth_roaming);
+
+       if (cred->max_bss_load)
+               fprintf(f, "\tmax_bss_load=%u\n",
+                       cred->max_bss_load);
 }
 
 

diff --git a/wpa_supplicant/interworking.c b/wpa_supplicant/interworking.c
index 7f42e77..860cddc 100644 (file)
--- a/wpa_supplicant/interworking.c
+++ b/wpa_supplicant/interworking.c
@@ -1131,6 +1131,28 @@ static int cred_below_min_backhaul(struct wpa_supplicant *wpa_s,
 }
 
 
+static int cred_over_max_bss_load(struct wpa_supplicant *wpa_s,
+                                 struct wpa_cred *cred, struct wpa_bss *bss)
+{
+       const u8 *ie;
+       int res;
+
+       if (!cred->max_bss_load)
+               return 0; /* No BSS Load constraint specified */
+
+       ie = wpa_bss_get_ie(bss, WLAN_EID_BSS_LOAD);
+       if (ie == NULL || ie[1] < 3)
+               return 0; /* No BSS Load advertised */
+
+       res = interworking_home_sp_cred(wpa_s, cred, bss->anqp ?
+                                       bss->anqp->domain_name : NULL);
+       if (res <= 0)
+               return 0; /* Not a home network */
+
+       return ie[4] > cred->max_bss_load;
+}
+
+
 static struct wpa_cred * interworking_credentials_available_roaming_consortium(
        struct wpa_supplicant *wpa_s, struct wpa_bss *bss, int ignore_bw)
 {
@@ -1164,6 +1186,8 @@ static struct wpa_cred * interworking_credentials_available_roaming_consortium(
                        continue;
                if (!ignore_bw && cred_below_min_backhaul(wpa_s, cred, bss))
                        continue;
+               if (!ignore_bw && cred_over_max_bss_load(wpa_s, cred, bss))
+                       continue;
 
                if (selected == NULL ||
                    selected->priority < cred->priority)
@@ -1656,6 +1680,9 @@ static struct wpa_cred * interworking_credentials_available_3gpp(
                        if (!ignore_bw &&
                            cred_below_min_backhaul(wpa_s, cred, bss))
                                continue;
+                       if (!ignore_bw &&
+                           cred_over_max_bss_load(wpa_s, cred, bss))
+                               continue;
                        if (selected == NULL ||
                            selected->priority < cred->priority)
                                selected = cred;
@@ -1703,6 +1730,9 @@ static struct wpa_cred * interworking_credentials_available_realm(
                                if (!ignore_bw &&
                                    cred_below_min_backhaul(wpa_s, cred, bss))
                                        continue;
+                               if (!ignore_bw &&
+                                   cred_over_max_bss_load(wpa_s, cred, bss))
+                                       continue;
                                if (selected == NULL ||
                                    selected->priority < cred->priority)
                                        selected = cred;
@@ -1994,10 +2024,12 @@ static void interworking_select_network(struct wpa_supplicant *wpa_s)
                        type = "roaming";
                else
                        type = "unknown";
-               wpa_msg(wpa_s, MSG_INFO, INTERWORKING_AP MACSTR " type=%s%s",
+               wpa_msg(wpa_s, MSG_INFO, INTERWORKING_AP MACSTR " type=%s%s%s",
                        MAC2STR(bss->bssid), type,
                        cred_below_min_backhaul(wpa_s, cred, bss) ?
-                       " below_min_backhaul=1" : "");
+                       " below_min_backhaul=1" : "",
+                       cred_over_max_bss_load(wpa_s, cred, bss) ?
+                       " over_max_bss_load=1" : "");
                if (wpa_s->auto_select ||
                    (wpa_s->conf->auto_interworking &&
                     wpa_s->auto_network_select)) {

diff --git a/wpa_supplicant/wpa_supplicant.conf b/wpa_supplicant/wpa_supplicant.conf
index 42954e6..3b0ea71 100644 (file)
--- a/wpa_supplicant/wpa_supplicant.conf
+++ b/wpa_supplicant/wpa_supplicant.conf
@@ -456,6 +456,13 @@ fast_reauth=1
 # min_dl_bandwidth_roaming
 # min_ul_bandwidth_roaming
 #
+# max_bss_load: Maximum BSS Load Channel Utilization (1..255)
+#      (PPS/<X+>/Policy/MaximumBSSLoadValue)
+#      This value is used as the maximum channel utilization for network
+#      selection purposes for home networks. If the AP does not advertise
+#      BSS Load or if the limit would prevent any connection, this constraint
+#      will be ignored.
+#
 # for example:
 #
 #cred={