wpa_priv: Use fromlen instead sizeof(struct sockaddr_un)

This gets rid of some dependencies on how extra octets at the end of the
struct sockaddr_un get "uninitialized" consistently by only using the
exact length of the address data from the recvfrom() call. This resolves
number of valgrind warnings about use of uninitialized memory.

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

wpa_supplicant/wpa_priv.c

@@ -36,10 +36,12 @@ struct wpa_priv_interface {
 	void *drv_priv;
 	void *drv_global_priv;
 	struct sockaddr_un drv_addr;
+	socklen_t drv_addr_len;
 	int wpas_registered;
 
 	struct l2_packet_data *l2[WPA_PRIV_MAX_L2];
 	struct sockaddr_un l2_addr[WPA_PRIV_MAX_L2];
+	socklen_t l2_addr_len[WPA_PRIV_MAX_L2];
 	struct wpa_priv_l2 {
 		struct wpa_priv_interface *parent;
 		int idx;
@@ -52,7 +54,7 @@ struct wpa_priv_global {
 
 
 static void wpa_priv_cmd_register(struct wpa_priv_interface *iface,
-				  struct sockaddr_un *from)
+				  struct sockaddr_un *from, socklen_t fromlen)
 {
 	int i;
 
@@ -104,7 +106,8 @@ static void wpa_priv_cmd_register(struct wpa_priv_interface *iface,
 	wpa_printf(MSG_DEBUG, "Driver wrapper '%s' initialized for interface "
 		   "'%s'", iface->driver_name, iface->ifname);
 
-	os_memcpy(&iface->drv_addr, from, sizeof(iface->drv_addr));
+	os_memcpy(&iface->drv_addr, from, fromlen);
+	iface->drv_addr_len = fromlen;
 	iface->wpas_registered = 1;
 
 	if (iface->driver->set_param &&
@@ -151,7 +154,8 @@ static void wpa_priv_cmd_scan(struct wpa_priv_interface *iface,
 
 
 static void wpa_priv_get_scan_results2(struct wpa_priv_interface *iface,
-				       struct sockaddr_un *from)
+				       struct sockaddr_un *from,
+				       socklen_t fromlen)
 {
 	struct wpa_scan_results *res;
 	u8 *buf = NULL, *pos, *end;
@@ -182,8 +186,7 @@ static void wpa_priv_get_scan_results2(struct wpa_priv_interface *iface,
 		pos += val;
 	}
 
-	sendto(iface->fd, buf, pos - buf, 0, (struct sockaddr *) from,
-	       sizeof(*from));
+	sendto(iface->fd, buf, pos - buf, 0, (struct sockaddr *) from, fromlen);
 
 	os_free(buf);
 	wpa_scan_results_free(res);
@@ -192,21 +195,21 @@ static void wpa_priv_get_scan_results2(struct wpa_priv_interface *iface,
 fail:
 	os_free(buf);
 	wpa_scan_results_free(res);
-	sendto(iface->fd, "", 0, 0, (struct sockaddr *) from, sizeof(*from));
+	sendto(iface->fd, "", 0, 0, (struct sockaddr *) from, fromlen);
 }
 
 
 static void wpa_priv_cmd_get_scan_results(struct wpa_priv_interface *iface,
-					  struct sockaddr_un *from)
+					  struct sockaddr_un *from,
+					  socklen_t fromlen)
 {
 	if (iface->drv_priv == NULL)
 		return;
 
 	if (iface->driver->get_scan_results2)
-		wpa_priv_get_scan_results2(iface, from);
+		wpa_priv_get_scan_results2(iface, from, fromlen);
 	else
-		sendto(iface->fd, "", 0, 0, (struct sockaddr *) from,
-		       sizeof(*from));
+		sendto(iface->fd, "", 0, 0, (struct sockaddr *) from, fromlen);
 }
 
 
@@ -311,7 +314,7 @@ static void wpa_priv_cmd_associate(struct wpa_priv_interface *iface,
 
 
 static void wpa_priv_cmd_get_bssid(struct wpa_priv_interface *iface,
-				   struct sockaddr_un *from)
+				   struct sockaddr_un *from, socklen_t fromlen)
 {
 	u8 bssid[ETH_ALEN];
 
@@ -323,16 +326,16 @@ static void wpa_priv_cmd_get_bssid(struct wpa_priv_interface *iface,
 		goto fail;
 
 	sendto(iface->fd, bssid, ETH_ALEN, 0, (struct sockaddr *) from,
-	       sizeof(*from));
+	       fromlen);
 	return;
 
 fail:
-	sendto(iface->fd, "", 0, 0, (struct sockaddr *) from, sizeof(*from));
+	sendto(iface->fd, "", 0, 0, (struct sockaddr *) from, fromlen);
 }
 
 
 static void wpa_priv_cmd_get_ssid(struct wpa_priv_interface *iface,
-				  struct sockaddr_un *from)
+				  struct sockaddr_un *from, socklen_t fromlen)
 {
 	u8 ssid[sizeof(int) + SSID_MAX_LEN];
 	int res;
@@ -349,11 +352,11 @@ static void wpa_priv_cmd_get_ssid(struct wpa_priv_interface *iface,
 	os_memcpy(ssid, &res, sizeof(int));
 
 	sendto(iface->fd, ssid, sizeof(ssid), 0, (struct sockaddr *) from,
-	       sizeof(*from));
+	       fromlen);
 	return;
 
 fail:
-	sendto(iface->fd, "", 0, 0, (struct sockaddr *) from, sizeof(*from));
+	sendto(iface->fd, "", 0, 0, (struct sockaddr *) from, fromlen);
 }
 
 
@@ -386,7 +389,7 @@ static void wpa_priv_cmd_set_key(struct wpa_priv_interface *iface,
 
 
 static void wpa_priv_cmd_get_capa(struct wpa_priv_interface *iface,
-				  struct sockaddr_un *from)
+				  struct sockaddr_un *from, socklen_t fromlen)
 {
 	struct wpa_driver_capa capa;
 
@@ -402,11 +405,11 @@ static void wpa_priv_cmd_get_capa(struct wpa_priv_interface *iface,
 	capa.extended_capa_mask = NULL;
 	capa.extended_capa_len = 0;
 	sendto(iface->fd, &capa, sizeof(capa), 0, (struct sockaddr *) from,
-	       sizeof(*from));
+	       fromlen);
 	return;
 
 fail:
-	sendto(iface->fd, "", 0, 0, (struct sockaddr *) from, sizeof(*from));
+	sendto(iface->fd, "", 0, 0, (struct sockaddr *) from, fromlen);
 }
 
 
@@ -427,7 +430,7 @@ static void wpa_priv_l2_rx(void *ctx, const u8 *src_addr, const u8 *buf,
 	msg.msg_iov = io;
 	msg.msg_iovlen = 2;
 	msg.msg_name = &iface->l2_addr[l2_ctx->idx];
-	msg.msg_namelen = sizeof(iface->l2_addr[l2_ctx->idx]);
+	msg.msg_namelen = iface->l2_addr_len[l2_ctx->idx];
 
 	if (sendmsg(iface->fd, &msg, 0) < 0) {
 		wpa_printf(MSG_ERROR, "sendmsg(l2 rx): %s", strerror(errno));
@@ -444,6 +447,7 @@ static int wpa_priv_allowed_l2_proto(u16 proto)
 
 static void wpa_priv_cmd_l2_register(struct wpa_priv_interface *iface,
 				     struct sockaddr_un *from,
+				     socklen_t fromlen,
 				     void *buf, size_t len)
 {
 	int *reg_cmd = buf;
@@ -474,7 +478,8 @@ static void wpa_priv_cmd_l2_register(struct wpa_priv_interface *iface,
 		return;
 	}
 
-	os_memcpy(&iface->l2_addr[idx], from, sizeof(iface->l2_addr[idx]));
+	os_memcpy(&iface->l2_addr[idx], from, fromlen);
+	iface->l2_addr_len[idx] = fromlen;
 
 	iface->l2_ctx[idx].idx = idx;
 	iface->l2_ctx[idx].parent = iface;
@@ -496,19 +501,20 @@ static void wpa_priv_cmd_l2_register(struct wpa_priv_interface *iface,
 	}
 
 	res = sendto(iface->fd, own_addr, ETH_ALEN, 0,
-		     (struct sockaddr *) from, sizeof(*from));
+		     (struct sockaddr *) from, fromlen);
 	wpa_printf(MSG_DEBUG, "L2 registration[idx=%d]: res=%d", idx, res);
 }
 
 
 static void wpa_priv_cmd_l2_unregister(struct wpa_priv_interface *iface,
-				       struct sockaddr_un *from)
+				       struct sockaddr_un *from,
+				       socklen_t fromlen)
 {
 	int idx;
 
 	for (idx = 0; idx < WPA_PRIV_MAX_L2; idx++) {
-		if (os_memcmp(&iface->l2_addr[idx], from,
-			      sizeof(struct sockaddr_un)) == 0)
+		if (iface->l2_addr_len[idx] == fromlen &&
+		    os_memcmp(&iface->l2_addr[idx], from, fromlen) == 0)
 			break;
 	}
 	if (idx == WPA_PRIV_MAX_L2) {
@@ -537,7 +543,7 @@ static void wpa_priv_cmd_l2_notify_auth_start(struct wpa_priv_interface *iface,
 
 
 static void wpa_priv_cmd_l2_send(struct wpa_priv_interface *iface,
-				 struct sockaddr_un *from,
+				 struct sockaddr_un *from, socklen_t fromlen,
 				 void *buf, size_t len)
 {
 	u8 *dst_addr;
@@ -546,8 +552,8 @@ static void wpa_priv_cmd_l2_send(struct wpa_priv_interface *iface,
 	int idx;
 
 	for (idx = 0; idx < WPA_PRIV_MAX_L2; idx++) {
-		if (os_memcmp(&iface->l2_addr[idx], from,
-			      sizeof(struct sockaddr_un)) == 0)
+		if (iface->l2_addr_len[idx] == fromlen &&
+		    os_memcmp(&iface->l2_addr[idx], from, fromlen) == 0)
 			break;
 	}
 	if (idx == WPA_PRIV_MAX_L2) {
@@ -621,7 +627,7 @@ static void wpa_priv_receive(int sock, void *eloop_ctx, void *sock_ctx)
 
 	switch (cmd) {
 	case PRIVSEP_CMD_REGISTER:
-		wpa_priv_cmd_register(iface, &from);
+		wpa_priv_cmd_register(iface, &from, fromlen);
 		break;
 	case PRIVSEP_CMD_UNREGISTER:
 		wpa_priv_cmd_unregister(iface, &from);
@@ -630,34 +636,35 @@ static void wpa_priv_receive(int sock, void *eloop_ctx, void *sock_ctx)
 		wpa_priv_cmd_scan(iface, cmd_buf, cmd_len);
 		break;
 	case PRIVSEP_CMD_GET_SCAN_RESULTS:
-		wpa_priv_cmd_get_scan_results(iface, &from);
+		wpa_priv_cmd_get_scan_results(iface, &from, fromlen);
 		break;
 	case PRIVSEP_CMD_ASSOCIATE:
 		wpa_priv_cmd_associate(iface, cmd_buf, cmd_len);
 		break;
 	case PRIVSEP_CMD_GET_BSSID:
-		wpa_priv_cmd_get_bssid(iface, &from);
+		wpa_priv_cmd_get_bssid(iface, &from, fromlen);
 		break;
 	case PRIVSEP_CMD_GET_SSID:
-		wpa_priv_cmd_get_ssid(iface, &from);
+		wpa_priv_cmd_get_ssid(iface, &from, fromlen);
 		break;
 	case PRIVSEP_CMD_SET_KEY:
 		wpa_priv_cmd_set_key(iface, cmd_buf, cmd_len);
 		break;
 	case PRIVSEP_CMD_GET_CAPA:
-		wpa_priv_cmd_get_capa(iface, &from);
+		wpa_priv_cmd_get_capa(iface, &from, fromlen);
 		break;
 	case PRIVSEP_CMD_L2_REGISTER:
-		wpa_priv_cmd_l2_register(iface, &from, cmd_buf, cmd_len);
+		wpa_priv_cmd_l2_register(iface, &from, fromlen,
+					 cmd_buf, cmd_len);
 		break;
 	case PRIVSEP_CMD_L2_UNREGISTER:
-		wpa_priv_cmd_l2_unregister(iface, &from);
+		wpa_priv_cmd_l2_unregister(iface, &from, fromlen);
 		break;
 	case PRIVSEP_CMD_L2_NOTIFY_AUTH_START:
 		wpa_priv_cmd_l2_notify_auth_start(iface, &from);
 		break;
 	case PRIVSEP_CMD_L2_SEND:
-		wpa_priv_cmd_l2_send(iface, &from, cmd_buf, cmd_len);
+		wpa_priv_cmd_l2_send(iface, &from, fromlen, cmd_buf, cmd_len);
 		break;
 	case PRIVSEP_CMD_SET_COUNTRY:
 		pos = cmd_buf;
@@ -831,7 +838,7 @@ static int wpa_priv_send_event(struct wpa_priv_interface *iface, int event,
 	msg.msg_iov = io;
 	msg.msg_iovlen = data ? 2 : 1;
 	msg.msg_name = &iface->drv_addr;
-	msg.msg_namelen = sizeof(iface->drv_addr);
+	msg.msg_namelen = iface->drv_addr_len;
 
 	if (sendmsg(iface->fd, &msg, 0) < 0) {
 		wpa_printf(MSG_ERROR, "sendmsg(wpas_socket): %s",
@@ -1115,7 +1122,7 @@ void wpa_supplicant_rx_eapol(void *ctx, const u8 *src_addr,
 	msg.msg_iov = io;
 	msg.msg_iovlen = 3;
 	msg.msg_name = &iface->drv_addr;
-	msg.msg_namelen = sizeof(iface->drv_addr);
+	msg.msg_namelen = iface->drv_addr_len;
 
 	if (sendmsg(iface->fd, &msg, 0) < 0)
 		wpa_printf(MSG_ERROR, "sendmsg(wpas_socket): %s",