Fixed scan buffer increasing with WEXT

We can now handle up to 65535 byte result buffer which is the maximum
due to WEXT using 16-bit length field. Previously, this was limited to
32768 bytes in practice even through we tried with 65536 and 131072
buffers which we just truncated into 0 in the 16-bit variable.

This more or less doubles the number of BSSes we can received from scan
results.

diff --git a/hostapd/driver_nl80211.c b/hostapd/driver_nl80211.c
index 7946b1e..3cb74d1 100644 (file)
--- a/hostapd/driver_nl80211.c
+++ b/hostapd/driver_nl80211.c
@@ -2291,10 +2291,12 @@ static int i802_get_ht_scan_res(struct i802_driver_data *drv)
                if (ioctl(drv->ioctl_sock, SIOCGIWSCAN, &iwr) == 0)
                        break;
 
-               if (errno == E2BIG && res_buf_len < 100000) {
+               if (errno == E2BIG && res_buf_len < 65535) {
                        os_free(res_buf);
                        res_buf = NULL;
                        res_buf_len *= 2;
+                       if (res_buf_len > 65535)
+                               res_buf_len = 65535; /* 16-bit length field */
                        wpa_printf(MSG_DEBUG, "Scan results did not fit - "
                                   "trying larger buffer (%lu bytes)",
                                   (unsigned long) res_buf_len);

diff --git a/src/drivers/driver_nl80211.c b/src/drivers/driver_nl80211.c
index 5e40cd2..2646270 100644 (file)
--- a/src/drivers/driver_nl80211.c
+++ b/src/drivers/driver_nl80211.c
@@ -1565,10 +1565,12 @@ static u8 * wpa_driver_nl80211_giwscan(struct wpa_driver_nl80211_data *drv,
                if (ioctl(drv->ioctl_sock, SIOCGIWSCAN, &iwr) == 0)
                        break;
 
-               if (errno == E2BIG && res_buf_len < 100000) {
+               if (errno == E2BIG && res_buf_len < 65535) {
                        os_free(res_buf);
                        res_buf = NULL;
                        res_buf_len *= 2;
+                       if (res_buf_len > 65535)
+                               res_buf_len = 65535; /* 16-bit length field */
                        wpa_printf(MSG_DEBUG, "Scan results did not fit - "
                                   "trying larger buffer (%lu bytes)",
                                   (unsigned long) res_buf_len);

diff --git a/src/drivers/driver_wext.c b/src/drivers/driver_wext.c
index b6273e5..631c63d 100644 (file)
--- a/src/drivers/driver_wext.c
+++ b/src/drivers/driver_wext.c
@@ -1140,10 +1140,12 @@ static u8 * wpa_driver_wext_giwscan(struct wpa_driver_wext_data *drv,
                if (ioctl(drv->ioctl_sock, SIOCGIWSCAN, &iwr) == 0)
                        break;
 
-               if (errno == E2BIG && res_buf_len < 100000) {
+               if (errno == E2BIG && res_buf_len < 65535) {
                        os_free(res_buf);
                        res_buf = NULL;
                        res_buf_len *= 2;
+                       if (res_buf_len > 65535)
+                               res_buf_len = 65535; /* 16-bit length field */
                        wpa_printf(MSG_DEBUG, "Scan results did not fit - "
                                   "trying larger buffer (%lu bytes)",
                                   (unsigned long) res_buf_len);

diff --git a/wpa_supplicant/ChangeLog b/wpa_supplicant/ChangeLog
index 4be7670..1d46ff9 100644 (file)
--- a/wpa_supplicant/ChangeLog
+++ b/wpa_supplicant/ChangeLog
@@ -3,6 +3,8 @@ ChangeLog for wpa_supplicant
 ????-??-?? - v0.7.0
        * increased wpa_cli ping interval to 5 seconds and made this
          configurable with a new command line options (-G<seconds>)
+       * fixed scan buffer processing with WEXT to handle up to 65535
+         byte result buffer (previously, limited to 32768 bytes)
 
 2009-01-06 - v0.6.7
        * added support for Wi-Fi Protected Setup (WPS)