[PATCH] hostapd: Disable HT MCS and set basic MCS per BSS

[Shay Bar]

Add the ability to disable specific supported HT MCS's per BSS via the new
(can be per bss) disabled_ht_mcs config.
This will overwrite the configured HT capab supported_mcs_set.

Add the ability to set specific basic MCS's (can be per BSS)
If absent (default) - no basic MCS's are set.

Signed-off-by: Shay Bar <shay.bar at celeno.com>
---
 hostapd/config_file.c  | 12 ++++++++++++
 hostapd/hostapd.conf   | 10 ++++++++++
 src/ap/ap_config.h     |  3 +++
 src/ap/ieee802_11_ht.c | 21 +++++++++++++++++++++
 4 files changed, 46 insertions(+)

diff --git a/hostapd/config_file.c b/hostapd/config_file.c
index e7a47d71d..9b78594ac 100644
--- a/hostapd/config_file.c
+++ b/hostapd/config_file.c
@@ -3234,6 +3234,18 @@ static int hostapd_config_fill(struct hostapd_config *conf,
                                   line);
                        return 1;
                }
+       } else if (os_strcmp(buf, "disabled_ht_mcs") == 0) {
+               if (hostapd_parse_intlist(&bss->disabled_ht_mcs, pos)) {
+                       wpa_printf(MSG_ERROR, "Line %d: invalid disabled mcs",
+                                  line);
+                       return 1;
+               }
+       } else if (os_strcmp(buf, "basic_ht_mcs") == 0) {
+               if (hostapd_parse_intlist(&bss->basic_ht_mcs, pos)) {
+                       wpa_printf(MSG_ERROR, "Line %d: invalid basic ht mcs",
+                                  line);
+                       return 1;
+               }
        } else if (os_strcmp(buf, "beacon_rate") == 0) {
                int val;

diff --git a/hostapd/hostapd.conf b/hostapd/hostapd.conf
index 91ac96785..367077370 100644
--- a/hostapd/hostapd.conf
+++ b/hostapd/hostapd.conf
@@ -270,6 +270,16 @@ fragm_threshold=-1
 #basic_rates=10 20 55 110
 #basic_rates=60 120 240

+# Disable supported HT MCS's per BSS
+# List of MCS's to disable
+# If absent (default) MCS's are as configured in the HT capab supported_mcs_set
+#disabled_ht_mcs=0 1
+
+# Set basic HT MCS's per BSS
+# List of MCS's
+# If absent (default) - no basic MCS's set
+#basic_ht_mcs=7
+
 # Beacon frame TX rate configuration
 # This sets the TX rate that is used to transmit Beacon frames. If this item is
 # not included, the driver default rate (likely lowest rate) is used.
diff --git a/src/ap/ap_config.h b/src/ap/ap_config.h
index b705c378f..3859ccbe0 100644
--- a/src/ap/ap_config.h
+++ b/src/ap/ap_config.h
@@ -314,6 +314,9 @@ struct hostapd_bss_config {

        struct hostapd_ssid ssid;

+       int *disabled_ht_mcs;
+       int *basic_ht_mcs;
+
        char *eap_req_id_text; /* optional displayable message sent with
                                * EAP Request-Identity */
        size_t eap_req_id_text_len;
diff --git a/src/ap/ieee802_11_ht.c b/src/ap/ieee802_11_ht.c
index 59ecbdce7..d0e87aa31 100644
--- a/src/ap/ieee802_11_ht.c
+++ b/src/ap/ieee802_11_ht.c
@@ -25,6 +25,7 @@ u8 * hostapd_eid_ht_capabilities(struct hostapd_data *hapd, u8 *eid)
 {
        struct ieee80211_ht_capabilities *cap;
        u8 *pos = eid;
+       int *disabled_ht_mcs = hapd->conf->disabled_ht_mcs;

        if (!hapd->iconf->ieee80211n || !hapd->iface->current_mode ||
            hapd->conf->disable_11n || is_6ghz_op_class(hapd->iconf->op_class))
@@ -40,6 +41,18 @@ u8 * hostapd_eid_ht_capabilities(struct hostapd_data *hapd, u8 *eid)
        os_memcpy(cap->supported_mcs_set, hapd->iface->current_mode->mcs_set,
                  16);

+       if (disabled_ht_mcs) {
+               int i = 0;
+
+               while (disabled_ht_mcs[i] != -1) {
+                       u8 *supp_mcs_set = cap->supported_mcs_set;
+
+                       while (*supp_mcs_set)
+                               *supp_mcs_set++ &= ~(1 << disabled_ht_mcs[i]);
+                       i++;
+               }
+       }
+
        /* TODO: ht_extended_capabilities (now fully disabled) */
        /* TODO: tx_bf_capability_info (now fully disabled) */
        /* TODO: asel_capabilities (now fully disabled) */
@@ -83,6 +96,7 @@ u8 * hostapd_eid_ht_operation(struct hostapd_data *hapd, u8 *eid)
 {
        struct ieee80211_ht_operation *oper;
        u8 *pos = eid;
+       int *basic = hapd->conf->basic_ht_mcs;

        if (!hapd->iconf->ieee80211n || hapd->conf->disable_11n ||
            is_6ghz_op_class(hapd->iconf->op_class))
@@ -103,6 +117,13 @@ u8 * hostapd_eid_ht_operation(struct hostapd_data *hapd, u8 *eid)
                oper->ht_param |= HT_INFO_HT_PARAM_SECONDARY_CHNL_BELOW |
                        HT_INFO_HT_PARAM_STA_CHNL_WIDTH;

+       if (basic) {
+               while (*basic != -1) {
+                       oper->basic_mcs_set[*basic / 8] |= (1 << (*basic % 8));
+                       basic++;
+               }
+       }
+
        pos += sizeof(*oper);

        return pos;
--
2.17.1

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