nl80211: Fetch maximum length of extra IE(s) for Probe Request frames

This can be helpful in determining which IE(s) to add to Probe Request
frames in scan commands based on driver capabilities.

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

diff --git a/src/drivers/driver.h b/src/drivers/driver.h
index fea7a7398f324e2bac34bb4b81eb7fe8b272fc81..de2b1de0977fe0008ff9e78dc263a6739dd25c0b 100644 (file)
--- a/src/drivers/driver.h
+++ b/src/drivers/driver.h
@@ -2493,6 +2493,10 @@ struct wpa_driver_capa {
        unsigned int mbssid_max_interfaces;
        /* Maximum profile periodicity for enhanced MBSSID advertisement */
        unsigned int ema_max_periodicity;
+
+       /* Maximum number of bytes of extra IE(s) that can be added to Probe
+        * Request frames */
+       size_t max_probe_req_ie_len;
 };
 
 

diff --git a/src/drivers/driver_nl80211.c b/src/drivers/driver_nl80211.c
index 2c94360f011c7919331b9d6524eedd27cf3c490f..68f22234fda7ac86af3536658b561845745065af 100644 (file)
--- a/src/drivers/driver_nl80211.c
+++ b/src/drivers/driver_nl80211.c
@@ -11388,7 +11388,8 @@ static int wpa_driver_nl80211_status(void *priv, char *buf, size_t buflen)
                                  "capa.max_sched_scan_plan_interval=%u\n"
                                  "capa.max_sched_scan_plan_iterations=%u\n"
                                  "capa.mbssid_max_interfaces=%u\n"
-                                 "capa.ema_max_periodicity=%u\n",
+                                 "capa.ema_max_periodicity=%u\n"
+                                 "capa.max_probe_req_ie_len=%zu\n",
                                  drv->capa.key_mgmt,
                                  drv->capa.enc,
                                  drv->capa.auth,
@@ -11413,7 +11414,8 @@ static int wpa_driver_nl80211_status(void *priv, char *buf, size_t buflen)
                                  drv->capa.max_sched_scan_plan_interval,
                                  drv->capa.max_sched_scan_plan_iterations,
                                  drv->capa.mbssid_max_interfaces,
-                                 drv->capa.ema_max_periodicity);
+                                 drv->capa.ema_max_periodicity,
+                                 drv->capa.max_probe_req_ie_len);
                if (os_snprintf_error(end - pos, res))
                        return pos - buf;
                pos += res;

diff --git a/src/drivers/driver_nl80211_capa.c b/src/drivers/driver_nl80211_capa.c
index 7c688acf8d72c5c85f9b6226cf2abb737cba6004..08a8552a101dd5b8fbcf06854bda4a9b2039a813 100644 (file)
--- a/src/drivers/driver_nl80211_capa.c
+++ b/src/drivers/driver_nl80211_capa.c
@@ -959,6 +959,10 @@ static int wiphy_info_handler(struct nl_msg *msg, void *arg)
                capa->max_scan_ssids =
                        nla_get_u8(tb[NL80211_ATTR_MAX_NUM_SCAN_SSIDS]);
 
+       if (tb[NL80211_ATTR_MAX_SCAN_IE_LEN])
+               capa->max_probe_req_ie_len =
+                       nla_get_u16(tb[NL80211_ATTR_MAX_SCAN_IE_LEN]);
+
        if (tb[NL80211_ATTR_MAX_NUM_SCHED_SCAN_SSIDS])
                capa->max_sched_scan_ssids =
                        nla_get_u8(tb[NL80211_ATTR_MAX_NUM_SCHED_SCAN_SSIDS]);
@@ -1199,6 +1203,10 @@ static int wpa_driver_nl80211_get_info(struct wpa_driver_nl80211_data *drv,
        info->capa = &drv->capa;
        info->drv = drv;
 
+       /* Default to large buffer of extra IE(s) to maintain previous behavior
+        * if the driver does not support reporting an accurate limit. */
+       info->capa->max_probe_req_ie_len = 1500;
+
        feat = get_nl80211_protocol_features(drv);
        if (feat & NL80211_PROTOCOL_FEATURE_SPLIT_WIPHY_DUMP)
                flags = NLM_F_DUMP;

diff --git a/src/drivers/driver_nl80211_scan.c b/src/drivers/driver_nl80211_scan.c
index 8e98fcdf8503bf6f0ce5947918a25342373b3ad5..f0313c1af7250d81b112bb1ad4fa7a1002ca2fc6 100644 (file)
--- a/src/drivers/driver_nl80211_scan.c
+++ b/src/drivers/driver_nl80211_scan.c
@@ -238,6 +238,11 @@ nl80211_scan_common(struct i802_bss *bss, u8 cmd,
        if (params->extra_ies) {
                wpa_hexdump(MSG_MSGDUMP, "nl80211: Scan extra IEs",
                            params->extra_ies, params->extra_ies_len);
+               if (params->extra_ies_len > drv->capa.max_probe_req_ie_len)
+                       wpa_printf(MSG_INFO,
+                                  "nl80211: Extra IEs for scan do not fit driver limit (%zu > %zu) - this is likely to fail",
+                                  params->extra_ies_len,
+                                  drv->capa.max_probe_req_ie_len);
                if (nla_put(msg, NL80211_ATTR_IE, params->extra_ies_len,
                            params->extra_ies))
                        goto fail;

diff --git a/wpa_supplicant/wpa_supplicant.c b/wpa_supplicant/wpa_supplicant.c
index 5267ffb300edcdc1cb30b50a8f803b98f65e818d..132d91598f4b3220136208d35b0e98eb6d43be04 100644 (file)
--- a/wpa_supplicant/wpa_supplicant.c
+++ b/wpa_supplicant/wpa_supplicant.c
@@ -7728,12 +7728,15 @@ static int wpa_supplicant_init_iface(struct wpa_supplicant *wpa_s,
                    capa.mac_addr_rand_sched_scan_supported)
                        wpa_s->mac_addr_rand_supported |=
                                (MAC_ADDR_RAND_SCHED_SCAN | MAC_ADDR_RAND_PNO);
+               wpa_s->drv_max_probe_req_ie_len = capa.max_probe_req_ie_len;
 
                wpa_drv_get_ext_capa(wpa_s, WPA_IF_STATION);
                if (wpa_s->extended_capa &&
                    wpa_s->extended_capa_len >= 3 &&
                    wpa_s->extended_capa[2] & 0x40)
                        wpa_s->multi_bss_support = 1;
+       } else {
+               wpa_s->drv_max_probe_req_ie_len = 1500;
        }
 #ifdef CONFIG_PASN
        wpa_pasn_sm_set_caps(wpa_s->wpa, wpa_s->drv_flags2);

diff --git a/wpa_supplicant/wpa_supplicant_i.h b/wpa_supplicant/wpa_supplicant_i.h
index 726f7caec981238d9dd25d229a7a8800759d0c18..b077ee9f9f0c49cbbe5d85b22cbdd3a979c7bc4b 100644 (file)
--- a/wpa_supplicant/wpa_supplicant_i.h
+++ b/wpa_supplicant/wpa_supplicant_i.h
@@ -938,6 +938,7 @@ struct wpa_supplicant {
        unsigned int drv_key_mgmt;
        unsigned int drv_rrm_flags;
        unsigned int drv_max_acl_mac_addrs;
+       size_t drv_max_probe_req_ie_len;
 
        /*
         * A bitmap of supported protocols for probe response offload. See