core: use nmp_utils_sysctl_open_netdir() to detect link-type

src/platform/nm-linux-platform.c

@@ -573,18 +573,14 @@ _lookup_cached_link (const NMPCache *cache, int ifindex, gboolean *completed_fro
 #define DEVTYPE_PREFIX "DEVTYPE="
 
 static char *
-_linktype_read_devtype (const char *ifname)
+_linktype_read_devtype (int dirfd)
 {
-	char uevent[NM_STRLEN ("/sys/class/net/123456789012345/uevent\0") + 100 /*safety*/];
 	char *contents = NULL;
 	char *cont, *end;
 
-	nm_sprintf_buf (uevent,
+	nm_assert (dirfd >= 0);
-	                "/sys/class/net/%s/uevent",
-	                NM_ASSERT_VALID_PATH_COMPONENT (ifname));
-	nm_assert (strlen (uevent) < sizeof (uevent) - 1);
 
-	if (!g_file_get_contents (uevent, &contents, NULL, NULL))
+	if (nm_utils_file_get_contents (dirfd, "uevent", 1*1024*1024, &contents, NULL, NULL) < 0)
 		return NULL;
 	for (cont = contents; cont; cont = end) {
 		end = strpbrk (cont, "\r\n");
@@ -680,9 +676,10 @@ _linktype_get_type (NMPlatform *platform,
 		return NM_LINK_TYPE_IP6TNL;
 
 	if (ifname) {
-		char anycast_mask[NM_STRLEN ("/sys/class/net/123456789012345/anycast_mask\0") + 100 /*safety*/];
+		nm_auto_close int dirfd = -1;
 		gs_free char *driver = NULL;
 		gs_free char *devtype = NULL;
+		char ifname_verified[IFNAMSIZ];
 
 		/* Fallback OVS detection for kernel <= 3.16 */
 		if (nmp_utils_ethtool_get_driver_info (ifname, &driver, NULL, NULL)) {
@@ -698,15 +695,12 @@ _linktype_get_type (NMPlatform *platform,
 			}
 		}
 
-		nm_sprintf_buf (anycast_mask,
+		dirfd = nmp_utils_sysctl_open_netdir (ifindex, ifname, ifname_verified);
-		                "/sys/class/net/%s/anycast_mask",
+		if (dirfd >= 0) {
-		                NM_ASSERT_VALID_PATH_COMPONENT (ifname));
+			if (faccessat (dirfd, "anycast_mask", F_OK, 0) == 0)
-		nm_assert (strlen (anycast_mask) < sizeof (anycast_mask) - 1);
-
-		if (g_file_test (anycast_mask, G_FILE_TEST_EXISTS))
 				return NM_LINK_TYPE_OLPC_MESH;
 
-		devtype = _linktype_read_devtype (ifname);
+			devtype = _linktype_read_devtype (dirfd);
 			for (i = 0; devtype && i < G_N_ELEMENTS (linktypes); i++) {
 				if (g_strcmp0 (devtype, linktypes[i].devtype) == 0) {
 					if (linktypes[i].nm_type == NM_LINK_TYPE_BNEP) {
@@ -721,8 +715,9 @@ _linktype_get_type (NMPlatform *platform,
 			}
 
 			/* Fallback for drivers that don't call SET_NETDEV_DEVTYPE() */
-		if (wifi_utils_is_wifi (ifindex, ifname))
+			if (wifi_utils_is_wifi (dirfd, ifname_verified))
 				return NM_LINK_TYPE_WIFI;
+		}
 
 		if (arptype == ARPHRD_ETHER) {
 			/* Misc non-upstream WWAN drivers.  rmnet is Qualcomm's proprietary

src/platform/wifi/wifi-utils.c

@@ -183,39 +183,19 @@ wifi_utils_deinit (WifiData *data)
 }
 
 gboolean
-wifi_utils_is_wifi (int ifindex, const char *ifname)
+wifi_utils_is_wifi (int dirfd, const char *ifname)
 {
-	int fd_sysnet;
+	g_return_val_if_fail (dirfd >= 0, FALSE);
-	int fd_phy80211;
-	char ifname_verified[IFNAMSIZ];
 
-	g_return_val_if_fail (ifindex > 0, FALSE);
+	if (faccessat (dirfd, "phy80211", F_OK, 0) == 0)
-
-	fd_sysnet = nmp_utils_sysctl_open_netdir (ifindex, ifname, ifname_verified);
-	if (fd_sysnet < 0)
-		return FALSE;
-
-	/* there might have been a race and ifname might be wrong. Below for checking
-	 * wext, use the possibly improved name that we just verified. */
-	ifname = ifname_verified;
-
-	fd_phy80211 = openat (fd_sysnet, "phy80211", O_CLOEXEC);
-	close (fd_sysnet);
-
-	if (fd_phy80211 >= 0) {
-		close (fd_phy80211);
 		return TRUE;
-	}
-
 #if HAVE_WEXT
 	if (wifi_wext_is_wifi (ifname))
 		return TRUE;
 #endif
-
 	return FALSE;
 }
 
-
 /* OLPC Mesh-only functions */
 
 guint32

src/platform/wifi/wifi-utils.h

@@ -28,7 +28,7 @@
 
 typedef struct WifiData WifiData;
 
-gboolean wifi_utils_is_wifi (int ifindex, const char *ifname);
+gboolean wifi_utils_is_wifi (int dirfd, const char *ifname);
 
 WifiData *wifi_utils_init (const char *iface, int ifindex, gboolean check_scan);