Allow multiple driver wrappers to be specified on command line

For example, -Dnl80211,wext could be used to automatically select
between nl80211 and wext. The first driver wrapper that is able to
initialize the interface will be used.

5 files changed, 51 insertions, 24 deletions

diff --git a/wpa_supplicant/ChangeLog b/wpa_supplicant/ChangeLog
index 1d46ff9..c96c6f7 100644
--- a/wpa_supplicant/ChangeLog
+++ b/wpa_supplicant/ChangeLog
@@ -5,6 +5,9 @@ ChangeLog for wpa_supplicant
 	  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)
+	* allow multiple driver wrappers to be specified on command line
+	  (e.g., -Dnl80211,wext); the first one that is able to initialize the
+	  interface will be used
 
 2009-01-06 - v0.6.7
 	* added support for Wi-Fi Protected Setup (WPS)
diff --git a/wpa_supplicant/README b/wpa_supplicant/README
index 2b94c23..760d64a 100644
--- a/wpa_supplicant/README
+++ b/wpa_supplicant/README
@@ -500,7 +500,7 @@ options:
   -C = ctrl_interface parameter (only used if -c is not)
   -i = interface name
   -d = increase debugging verbosity (-dd even more)
-  -D = driver name
+  -D = driver name (can be multiple drivers: nl80211,wext)
   -f = Log output to default log location (normally /tmp)
   -g = global ctrl_interface
   -K = include keys (passwords, etc.) in debug output
@@ -544,6 +544,13 @@ enabled:
 
 wpa_supplicant -c/etc/wpa_supplicant.conf -iwlan0 -d
 
+If the specific driver wrapper is not known beforehand, it is possible
+to specify multiple comma separated driver wrappers on the command
+line. wpa_supplicant will use the first driver wrapper that is able to
+initialize the interface.
+
+wpa_supplicant -Dnl80211,wext -c/etc/wpa_supplicant.conf -iwlan0
+
 
 wpa_supplicant can control multiple interfaces (radios) either by
 running one process for each interface separately or by running just
diff --git a/wpa_supplicant/doc/docbook/wpa_supplicant.sgml b/wpa_supplicant/doc/docbook/wpa_supplicant.sgml
index 9798ced..3aae51b 100644
--- a/wpa_supplicant/doc/docbook/wpa_supplicant.sgml
+++ b/wpa_supplicant/doc/docbook/wpa_supplicant.sgml
@@ -388,8 +388,8 @@
       <varlistentry>
 	<term>-D driver</term>
 	<listitem>
-	  <para>Driver to use. (Per interface, see the available options
-		  below.)</para>
+	  <para>Driver to use (can be multiple drivers: nl80211,wext).
+		  (Per interface, see the available options below.)</para>
 	</listitem>
       </varlistentry>
 
@@ -509,6 +509,15 @@ wpa_supplicant -B -c/etc/wpa_supplicant.conf -iwlan0
 wpa_supplicant -c/etc/wpa_supplicant.conf -iwlan0 -d
 </programlisting></blockquote>
 
+    <para>If the specific driver wrapper is not known beforehand, it is
+    possible to specify multiple comma separated driver wrappers on the command
+    line. <command>wpa_supplicant</command> will use the first driver
+    wrapper that is able to initialize the interface.</para>
+
+<blockquote><programlisting>
+wpa_supplicant -Dnl80211,wext -c/etc/wpa_supplicant.conf -iwlan0
+</programlisting></blockquote>
+
     <para><command>wpa_supplicant</command> can control multiple
     interfaces (radios) either by running one process for each
     interface separately or by running just one process and list of
diff --git a/wpa_supplicant/main.c b/wpa_supplicant/main.c
index 6f90cc5..7e9919b 100644
--- a/wpa_supplicant/main.c
+++ b/wpa_supplicant/main.c
@@ -52,7 +52,7 @@ static void usage(void)
 	       "  -C = ctrl_interface parameter (only used if -c is not)\n"
 	       "  -i = interface name\n"
 	       "  -d = increase debugging verbosity (-dd even more)\n"
-	       "  -D = driver name\n"
+	       "  -D = driver name (can be multiple drivers: nl80211,wext)\n"
 #ifdef CONFIG_DEBUG_FILE
 	       "  -f = log output to debug file instead of stdout\n"
 #endif /* CONFIG_DEBUG_FILE */
diff --git a/wpa_supplicant/wpa_supplicant.c b/wpa_supplicant/wpa_supplicant.c
index 6eb0eec..9b6f088 100644
--- a/wpa_supplicant/wpa_supplicant.c
+++ b/wpa_supplicant/wpa_supplicant.c
@@ -1491,6 +1491,8 @@ static int wpa_supplicant_set_driver(struct wpa_supplicant *wpa_s,
 				     const char *name)
 {
 	int i;
+	size_t len;
+	const char *pos;
 
 	if (wpa_s == NULL)
 		return -1;
@@ -1507,14 +1509,21 @@ static int wpa_supplicant_set_driver(struct wpa_supplicant *wpa_s,
 		return 0;
 	}
 
+	pos = os_strchr(name, ',');
+	if (pos)
+		len = pos - name;
+	else
+		len = os_strlen(name);
 	for (i = 0; wpa_supplicant_drivers[i]; i++) {
-		if (os_strcmp(name, wpa_supplicant_drivers[i]->name) == 0) {
+		if (os_strlen(wpa_supplicant_drivers[i]->name) == len &&
+		    os_strncmp(name, wpa_supplicant_drivers[i]->name, len) ==
+		    0) {
 			wpa_s->driver = wpa_supplicant_drivers[i];
 			return 0;
 		}
 	}
 
-	wpa_printf(MSG_ERROR, "Unsupported driver '%s'.\n", name);
+	wpa_printf(MSG_ERROR, "Unsupported driver '%s'.", name);
 	return -1;
 }
 
@@ -1710,6 +1719,9 @@ static struct wpa_supplicant * wpa_supplicant_alloc(void)
 static int wpa_supplicant_init_iface(struct wpa_supplicant *wpa_s,
 				     struct wpa_interface *iface)
 {
+	const char *ifname, *driver;
+	struct wpa_driver_capa capa;
+
 	wpa_printf(MSG_DEBUG, "Initializing interface '%s' conf '%s' driver "
 		   "'%s' ctrl_interface '%s' bridge '%s'", iface->ifname,
 		   iface->confname ? iface->confname : "N/A",
@@ -1717,10 +1729,6 @@ static int wpa_supplicant_init_iface(struct wpa_supplicant *wpa_s,
 		   iface->ctrl_interface ? iface->ctrl_interface : "N/A",
 		   iface->bridge_ifname ? iface->bridge_ifname : "N/A");
 
-	if (wpa_supplicant_set_driver(wpa_s, iface->driver) < 0) {
-		return -1;
-	}
-
 	if (iface->confname) {
 #ifdef CONFIG_BACKEND_FILE
 		wpa_s->confname = os_rel2abs_path(iface->confname);
@@ -1788,18 +1796,6 @@ static int wpa_supplicant_init_iface(struct wpa_supplicant *wpa_s,
 			   sizeof(wpa_s->bridge_ifname));
 	}
 
-	return 0;
-}
-
-
-static int wpa_supplicant_init_iface2(struct wpa_supplicant *wpa_s)
-{
-	const char *ifname;
-	struct wpa_driver_capa capa;
-
-	wpa_printf(MSG_DEBUG, "Initializing interface (2) '%s'",
-		   wpa_s->ifname);
-
 	/* RSNA Supplicant Key Management - INITIALIZE */
 	eapol_sm_notify_portEnabled(wpa_s->eapol, FALSE);
 	eapol_sm_notify_portValid(wpa_s->eapol, FALSE);
@@ -1808,8 +1804,21 @@ static int wpa_supplicant_init_iface2(struct wpa_supplicant *wpa_s)
 	 * L2 receive handler so that association events are processed before
 	 * EAPOL-Key packets if both become available for the same select()
 	 * call. */
+	driver = iface->driver;
+next_driver:
+	if (wpa_supplicant_set_driver(wpa_s, driver) < 0)
+		return -1;
+
 	wpa_s->drv_priv = wpa_drv_init(wpa_s, wpa_s->ifname);
 	if (wpa_s->drv_priv == NULL) {
+		const char *pos;
+		pos = os_strchr(driver, ',');
+		if (pos) {
+			wpa_printf(MSG_DEBUG, "Failed to initialize driver "
+				   "interface - try next driver wrapper");
+			driver = pos + 1;
+			goto next_driver;
+		}
 		wpa_printf(MSG_ERROR, "Failed to initialize driver interface");
 		return -1;
 	}
@@ -1965,8 +1974,7 @@ struct wpa_supplicant * wpa_supplicant_add_iface(struct wpa_global *global,
 	if (wpa_s == NULL)
 		return NULL;
 
-	if (wpa_supplicant_init_iface(wpa_s, iface) ||
-	    wpa_supplicant_init_iface2(wpa_s)) {
+	if (wpa_supplicant_init_iface(wpa_s, iface)) {
 		wpa_printf(MSG_DEBUG, "Failed to add interface %s",
 			   iface->ifname);
 		wpa_supplicant_deinit_iface(wpa_s);