[PATCH] nl80211: add extra-ies only if allowed by driver

[David Bauer]

Upgrading wpa_supplicant from 2.9 to 2.10 breaks broadcom-wl
based adapters. The reason for it is hostapd tries to install additional
IEs for scanning while the driver does not support this.

The kernel indicates the maximum number of bytes for additional scan IEs
using the NL80211_ATTR_MAX_SCAN_IE_LEN attribute. Save this value and
only add additional scan IEs in case the driver can accommodate these
additional IEs.

Reported-by: Étienne Morice <neon.emorice at mail.com>
Tested-by: Étienne Morice <neon.emorice at mail.com>
Signed-off-by: David Bauer <mail at david-bauer.net>
---
 src/drivers/driver.h              | 3 +++
 src/drivers/driver_nl80211_capa.c | 4 ++++
 src/drivers/driver_nl80211_scan.c | 2 +-
 3 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/src/drivers/driver.h b/src/drivers/driver.h
index d3312a34d..b5b626451 100644
--- a/src/drivers/driver.h
+++ b/src/drivers/driver.h
@@ -2052,6 +2052,9 @@ struct wpa_driver_capa {
 	/** Maximum number of iterations in a single scan plan */
 	u32 max_sched_scan_plan_iterations;
 
+	/** Maximum number of extra IE bytes for scans */
+	u16 max_scan_ie_len;
+
 	/** Whether sched_scan (offloaded scanning) is supported */
 	int sched_scan_supported;
 
diff --git a/src/drivers/driver_nl80211_capa.c b/src/drivers/driver_nl80211_capa.c
index 83868b78e..b33b6badb 100644
--- a/src/drivers/driver_nl80211_capa.c
+++ b/src/drivers/driver_nl80211_capa.c
@@ -885,6 +885,10 @@ static int wiphy_info_handler(struct nl_msg *msg, void *arg)
 			nla_get_u32(tb[NL80211_ATTR_MAX_SCAN_PLAN_ITERATIONS]);
 	}
 
+	if (tb[NL80211_ATTR_MAX_SCAN_IE_LEN])
+		capa->max_scan_ie_len =
+			nla_get_u16(tb[NL80211_ATTR_MAX_SCAN_IE_LEN]);
+
 	if (tb[NL80211_ATTR_MAX_MATCH_SETS])
 		capa->max_match_sets =
 			nla_get_u8(tb[NL80211_ATTR_MAX_MATCH_SETS]);
diff --git a/src/drivers/driver_nl80211_scan.c b/src/drivers/driver_nl80211_scan.c
index 131608480..b0f095192 100644
--- a/src/drivers/driver_nl80211_scan.c
+++ b/src/drivers/driver_nl80211_scan.c
@@ -207,7 +207,7 @@ nl80211_scan_common(struct i802_bss *bss, u8 cmd,
 		wpa_printf(MSG_DEBUG, "nl80211: Passive scan requested");
 	}
 
-	if (params->extra_ies) {
+	if (params->extra_ies && drv->capa.max_scan_ie_len >= params->extra_ies_len) {
 		wpa_hexdump(MSG_MSGDUMP, "nl80211: Scan extra IEs",
 			    params->extra_ies, params->extra_ies_len);
 		if (nla_put(msg, NL80211_ATTR_IE, params->extra_ies_len,
-- 
2.35.1