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.

src/drivers/driver_nl80211.c

@@ -89,7 +89,7 @@ static void wpa_driver_nl80211_scan_timeout(void *eloop_ctx,
 static int wpa_driver_nl80211_set_mode(void *priv, int mode);
 static int wpa_driver_nl80211_flush_pmkid(void *priv);
 static int wpa_driver_nl80211_get_range(void *priv);
-static void
+static int
 wpa_driver_nl80211_finish_drv_init(struct wpa_driver_nl80211_data *drv);
 
 
@@ -1548,10 +1548,14 @@ static void * wpa_driver_nl80211_init(void *ctx, const char *ifname)
 				 ctx);
 	drv->wext_event_sock = s;
 
-	wpa_driver_nl80211_finish_drv_init(drv);
+	if (wpa_driver_nl80211_finish_drv_init(drv))
+		goto err7;
 
 	return drv;
 
+err7:
+	eloop_unregister_read_sock(drv->wext_event_sock);
+	close(drv->wext_event_sock);
 err6:
 	close(drv->ioctl_sock);
 err5:
@@ -1568,17 +1572,21 @@ err1:
 }
 
 
-static void
+static int
 wpa_driver_nl80211_finish_drv_init(struct wpa_driver_nl80211_data *drv)
 {
 	int flags;
 
-	if (wpa_driver_nl80211_get_ifflags(drv, &flags) != 0)
+	if (wpa_driver_nl80211_get_ifflags(drv, &flags) != 0) {
-		printf("Could not get interface '%s' flags\n", drv->ifname);
+		wpa_printf(MSG_ERROR, "Could not get interface '%s' flags",
-	else if (!(flags & IFF_UP)) {
-		if (wpa_driver_nl80211_set_ifflags(drv, flags | IFF_UP) != 0) {
-			printf("Could not set interface '%s' UP\n",
 			   drv->ifname);
+		return -1;
+	}
+	if (!(flags & IFF_UP)) {
+		if (wpa_driver_nl80211_set_ifflags(drv, flags | IFF_UP) != 0) {
+			wpa_printf(MSG_ERROR, "Could not set interface '%s' "
+				   "UP", drv->ifname);
+			return -1;
 		}
 	}
 
@@ -1598,6 +1606,8 @@ wpa_driver_nl80211_finish_drv_init(struct wpa_driver_nl80211_data *drv)
 	wpa_driver_nl80211_capa(drv);
 
 	wpa_driver_nl80211_send_oper_ifla(drv, 1, IF_OPER_DORMANT);
+
+	return 0;
 }
 
 

src/drivers/driver_wext.c

@@ -34,7 +34,7 @@
 
 static int wpa_driver_wext_flush_pmkid(void *priv);
 static int wpa_driver_wext_get_range(void *priv);
-static void wpa_driver_wext_finish_drv_init(struct wpa_driver_wext_data *drv);
+static int wpa_driver_wext_finish_drv_init(struct wpa_driver_wext_data *drv);
 
 
 static int wpa_driver_wext_send_oper_ifla(struct wpa_driver_wext_data *drv,
@@ -913,50 +913,60 @@ void * wpa_driver_wext_init(void *ctx, const char *ifname)
 	drv->ioctl_sock = socket(PF_INET, SOCK_DGRAM, 0);
 	if (drv->ioctl_sock < 0) {
 		perror("socket(PF_INET,SOCK_DGRAM)");
-		os_free(drv);
+		goto err1;
-		return NULL;
 	}
 
 	s = socket(PF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
 	if (s < 0) {
 		perror("socket(PF_NETLINK,SOCK_RAW,NETLINK_ROUTE)");
-		close(drv->ioctl_sock);
+		goto err2;
-		os_free(drv);
-		return NULL;
 	}
+	drv->event_sock = s;
 
 	os_memset(&local, 0, sizeof(local));
 	local.nl_family = AF_NETLINK;
 	local.nl_groups = RTMGRP_LINK;
 	if (bind(s, (struct sockaddr *) &local, sizeof(local)) < 0) {
 		perror("bind(netlink)");
-		close(s);
+		goto err3;
-		close(drv->ioctl_sock);
-		os_free(drv);
-		return NULL;
 	}
 
 	eloop_register_read_sock(s, wpa_driver_wext_event_receive, drv, ctx);
-	drv->event_sock = s;
 
 	drv->mlme_sock = -1;
 
-	wpa_driver_wext_finish_drv_init(drv);
+	if (wpa_driver_wext_finish_drv_init(drv) < 0)
+		goto err4;
 
 	return drv;
+
+err4:
+	eloop_unregister_read_sock(drv->event_sock);
+err3:
+	close(drv->event_sock);
+err2:
+	close(drv->ioctl_sock);
+err1:
+	os_free(drv);
+	return NULL;
 }
 
 
-static void wpa_driver_wext_finish_drv_init(struct wpa_driver_wext_data *drv)
+static int wpa_driver_wext_finish_drv_init(struct wpa_driver_wext_data *drv)
 {
 	int flags;
 
-	if (wpa_driver_wext_get_ifflags(drv, &flags) != 0)
+	if (wpa_driver_wext_get_ifflags(drv, &flags) != 0) {
-		printf("Could not get interface '%s' flags\n", drv->ifname);
+		wpa_printf(MSG_ERROR, "Could not get interface '%s' flags",
-	else if (!(flags & IFF_UP)) {
-		if (wpa_driver_wext_set_ifflags(drv, flags | IFF_UP) != 0) {
-			printf("Could not set interface '%s' UP\n",
 			   drv->ifname);
+		return -1;
+	}
+
+	if (!(flags & IFF_UP)) {
+		if (wpa_driver_wext_set_ifflags(drv, flags | IFF_UP) != 0) {
+			wpa_printf(MSG_ERROR, "Could not set interface '%s' "
+				   "UP", drv->ifname);
+			return -1;
 		} else {
 			/*
 			 * Wait some time to allow driver to initialize before
@@ -977,7 +987,9 @@ static void wpa_driver_wext_finish_drv_init(struct wpa_driver_wext_data *drv)
 	wpa_driver_wext_flush_pmkid(drv);
 
 	if (wpa_driver_wext_set_mode(drv, 0) < 0) {
-		printf("Could not configure driver to use managed mode\n");
+		wpa_printf(MSG_DEBUG, "Could not configure driver to use "
+			   "managed mode");
+		/* Try to use it anyway */
 	}
 
 	wpa_driver_wext_get_range(drv);
@@ -1000,6 +1012,8 @@ static void wpa_driver_wext_finish_drv_init(struct wpa_driver_wext_data *drv)
 	}
 
 	wpa_driver_wext_send_oper_ifla(drv, 1, IF_OPER_DORMANT);
+
+	return 0;
 }
 
 

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)

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

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
+	  <para>Driver to use (can be multiple drivers: nl80211,wext).
-		  below.)</para>
+		  (Per interface, see the available options below.)</para>
 	</listitem>
       </varlistentry>
 
@@ -507,6 +507,15 @@ wpa_supplicant -B -c/etc/wpa_supplicant.conf -iwlan0
 
 <blockquote><programlisting>
 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

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 */

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) ||
+	if (wpa_supplicant_init_iface(wpa_s, iface)) {
-	    wpa_supplicant_init_iface2(wpa_s)) {
 		wpa_printf(MSG_DEBUG, "Failed to add interface %s",
 			   iface->ifname);
 		wpa_supplicant_deinit_iface(wpa_s);