WPS ER: Allow UPnP interface to be forced

"WPS_ER_START ifname=<interace>" can now be used to force a specific
interface to be used for UPnP operations. This is especially useful for
automated test cases where the lo interface can now be used easily to
perform ER operations.

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

src/wps/wps_er.c

@@ -1271,6 +1271,22 @@ wps_er_init(struct wps_context *wps, const char *ifname, const char *filter)
 	/* Limit event_id to < 32 bits to avoid issues with atoi() */
 	er->event_id &= 0x0fffffff;
 
+	if (filter && os_strncmp(filter, "ifname=", 7) == 0) {
+		const char *pos, *end;
+		pos = filter + 7;
+		end = os_strchr(pos, ' ');
+		if (end) {
+			size_t len = end - pos;
+			os_strlcpy(er->ifname, pos, len < sizeof(er->ifname) ?
+				   len + 1 : sizeof(er->ifname));
+			filter = end + 1;
+		} else {
+			os_strlcpy(er->ifname, pos, sizeof(er->ifname));
+			filter = NULL;
+		}
+		er->forced_ifname = 1;
+	}
+
 	if (filter) {
 		if (inet_aton(filter, &er->filter_addr) == 0) {
 			wpa_printf(MSG_INFO, "WPS UPnP: Invalid filter "
@@ -1281,10 +1297,10 @@ wps_er_init(struct wps_context *wps, const char *ifname, const char *filter)
 		wpa_printf(MSG_DEBUG, "WPS UPnP: Only accepting connections "
 			   "with %s", filter);
 	}
-	if (get_netif_info(ifname, &er->ip_addr, &er->ip_addr_text,
+	if (get_netif_info(er->ifname, &er->ip_addr, &er->ip_addr_text,
 			   er->mac_addr)) {
 		wpa_printf(MSG_INFO, "WPS UPnP: Could not get IP/MAC address "
-			   "for %s. Does it have IP address?", ifname);
+			   "for %s. Does it have IP address?", er->ifname);
 		wps_er_deinit(er, NULL, NULL);
 		return NULL;
 	}

src/wps/wps_er.h

@@ -76,6 +76,7 @@ struct wps_er_ap_settings {
 struct wps_er {
 	struct wps_context *wps;
 	char ifname[17];
+	int forced_ifname;
 	u8 mac_addr[ETH_ALEN]; /* mac addr of network i.f. we use */
 	char *ip_addr_text; /* IP address of network i.f. we use */
 	unsigned ip_addr; /* IP address of network i.f. we use (host order) */

src/wps/wps_er_ssdp.c

@@ -166,7 +166,9 @@ int wps_er_ssdp_init(struct wps_er *er)
 		return -1;
 	}
 
-	er->multicast_sd = ssdp_open_multicast_sock(er->ip_addr);
+	er->multicast_sd = ssdp_open_multicast_sock(er->ip_addr,
+						    er->forced_ifname ?
+						    er->ifname : NULL);
 	if (er->multicast_sd < 0) {
 		wpa_printf(MSG_INFO, "WPS ER: Failed to open multicast socket "
 			   "for SSDP");

src/wps/wps_upnp_i.h

@@ -171,7 +171,7 @@ void ssdp_listener_stop(struct upnp_wps_device_sm *sm);
 int ssdp_listener_start(struct upnp_wps_device_sm *sm);
 int ssdp_listener_open(void);
 int add_ssdp_network(const char *net_if);
-int ssdp_open_multicast_sock(u32 ip_addr);
+int ssdp_open_multicast_sock(u32 ip_addr, const char *forced_ifname);
 int ssdp_open_multicast(struct upnp_wps_device_sm *sm);
 
 /* wps_upnp_web.c */

src/wps/wps_upnp_ssdp.c

@@ -3,7 +3,7 @@
  * Copyright (c) 2000-2003 Intel Corporation
  * Copyright (c) 2006-2007 Sony Corporation
  * Copyright (c) 2008-2009 Atheros Communications
- * Copyright (c) 2009, Jouni Malinen <j@w1.fi>
+ * Copyright (c) 2009-2013, Jouni Malinen <j@w1.fi>
  *
  * See wps_upnp.c for more details on licensing and code history.
  */
@@ -13,6 +13,9 @@
 #include <fcntl.h>
 #include <sys/ioctl.h>
 #include <net/route.h>
+#ifdef __linux__
+#include <net/if.h>
+#endif /* __linux__ */
 
 #include "common.h"
 #include "uuid.h"
@@ -854,7 +857,7 @@ fail:
 }
 
 
-int ssdp_open_multicast_sock(u32 ip_addr)
+int ssdp_open_multicast_sock(u32 ip_addr, const char *forced_ifname)
 {
 	int sd;
 	 /* per UPnP-arch-DeviceArchitecture, 1. Discovery, keep IP packet
@@ -865,6 +868,22 @@ int ssdp_open_multicast_sock(u32 ip_addr)
 	if (sd < 0)
 		return -1;
 
+	if (forced_ifname) {
+#ifdef __linux__
+		struct ifreq req;
+		os_memset(&req, 0, sizeof(req));
+		os_strlcpy(req.ifr_name, forced_ifname, sizeof(req.ifr_name));
+		if (setsockopt(sd, SOL_SOCKET, SO_BINDTODEVICE, &req,
+			       sizeof(req)) < 0) {
+			wpa_printf(MSG_INFO, "WPS UPnP: Failed to bind "
+				   "multicast socket to ifname %s: %s",
+				   forced_ifname, strerror(errno));
+			close(sd);
+			return -1;
+		}
+#endif /* __linux__ */
+	}
+
 #if 0   /* maybe ok if we sometimes block on writes */
 	if (fcntl(sd, F_SETFL, O_NONBLOCK) != 0) {
 		close(sd);
@@ -924,7 +943,7 @@ int ssdp_open_multicast_sock(u32 ip_addr)
  */
 int ssdp_open_multicast(struct upnp_wps_device_sm *sm)
 {
-	sm->multicast_sd = ssdp_open_multicast_sock(sm->ip_addr);
+	sm->multicast_sd = ssdp_open_multicast_sock(sm->ip_addr, NULL);
 	if (sm->multicast_sd < 0)
 		return -1;
 	return 0;