platform: link features (carrier-detect and vlans)

Thanks to Jiří Pírko for help with ethtool features.

src/platform/nm-fake-platform.c

@@ -268,6 +268,38 @@ link_uses_arp (NMPlatform *platform, int ifindex)
 	return device ? device->arp : FALSE;
 }
 
+static gboolean
+link_supports_carrier_detect (NMPlatform *platform, int ifindex)
+{
+	NMPlatformLink *device = link_get (platform, ifindex);
+
+	if (!device)
+		return FALSE;
+
+	switch (device->type) {
+	case NM_LINK_TYPE_DUMMY:
+		return FALSE;
+	default:
+		return TRUE;
+	}
+}
+
+static gboolean
+link_supports_vlans (NMPlatform *platform, int ifindex)
+{
+	NMPlatformLink *device = link_get (platform, ifindex);
+
+	if (!device)
+		return FALSE;
+
+	switch (device->type) {
+	case NM_LINK_TYPE_LOOPBACK:
+		return FALSE;
+	default:
+		return TRUE;
+	}
+}
+
 /******************************************************************/
 
 static GArray *
@@ -698,6 +730,9 @@ nm_fake_platform_class_init (NMFakePlatformClass *klass)
 	platform_class->link_is_connected = link_is_connected;
 	platform_class->link_uses_arp = link_uses_arp;
 
+	platform_class->link_supports_carrier_detect = link_supports_carrier_detect;
+	platform_class->link_supports_vlans = link_supports_vlans;
+
 	platform_class->ip4_address_get_all = ip4_address_get_all;
 	platform_class->ip6_address_get_all = ip6_address_get_all;
 	platform_class->ip4_address_add = ip4_address_add;

src/platform/nm-linux-platform.c

@@ -25,6 +25,9 @@
 #include <netinet/icmp6.h>
 #include <netinet/in.h>
 #include <linux/if_arp.h>
+#include <sys/ioctl.h>
+#include <linux/sockios.h>
+#include <linux/ethtool.h>
 #include <netlink/netlink.h>
 #include <netlink/object.h>
 #include <netlink/cache.h>
@@ -816,6 +819,66 @@ link_set_noarp (NMPlatform *platform, int ifindex)
 	return link_change_flags (platform, ifindex, IFF_NOARP, TRUE);
 }
 
+static gboolean
+ethtool_get (const char *name, gpointer edata)
+{
+	struct ifreq ifr;
+	int fd;
+
+	memset (&ifr, 0, sizeof (ifr));
+	strncpy (ifr.ifr_name, name, IFNAMSIZ);
+	ifr.ifr_data = edata;
+
+	fd = socket (PF_INET, SOCK_DGRAM, 0);
+	if (fd < 0) {
+		error ("ethtool: Could not open socket.");
+		return FALSE;
+	}
+
+	if (ioctl (fd, SIOCETHTOOL, &ifr) < 0) {
+		debug ("ethtool: Request failed: %s", strerror (errno));
+		close (fd);
+		return FALSE;
+	}
+
+	close (fd);
+	return TRUE;
+}
+
+static gboolean
+link_supports_carrier_detect (NMPlatform *platform, int ifindex)
+{
+	const char *name = nm_platform_link_get_name (ifindex);
+	struct ethtool_cmd edata = { .cmd = ETHTOOL_GLINK };
+
+	/* We ignore the result and only return FALSE on error */
+	return name && ethtool_get (name, &edata);
+}
+
+#define NETIF_F_VLAN_CHALLENGED (1 << 10)
+
+static gboolean
+link_supports_vlans (NMPlatform *platform, int ifindex)
+{
+	auto_nl_object struct rtnl_link *rtnllink = link_get (platform, ifindex);
+	const char *name = nm_platform_link_get_name (ifindex);
+	struct {
+		struct ethtool_gfeatures features;
+		struct ethtool_get_features_block features_block;
+	} edata = { .features = { .cmd = ETHTOOL_GFEATURES, .size = 1 } };
+
+	/* Only ARPHDR_ETHER links can possibly support VLANs. Thanks to Dan Winship
+	 * for pointing this out.
+	 */
+	if (!rtnllink || rtnl_link_get_arptype (rtnllink) != ARPHRD_ETHER)
+		return FALSE;
+
+	if (!name || !ethtool_get (name, &edata))
+		return FALSE;
+
+	return !(edata.features.features[0].active & NETIF_F_VLAN_CHALLENGED);
+}
+
 /******************************************************************/
 
 static int
@@ -1274,6 +1337,9 @@ nm_linux_platform_class_init (NMLinuxPlatformClass *klass)
 	platform_class->link_is_connected = link_is_connected;
 	platform_class->link_uses_arp = link_uses_arp;
 
+	platform_class->link_supports_carrier_detect = link_supports_carrier_detect;
+	platform_class->link_supports_vlans = link_supports_vlans;
+
 	platform_class->ip4_address_get_all = ip4_address_get_all;
 	platform_class->ip6_address_get_all = ip6_address_get_all;
 	platform_class->ip4_address_add = ip4_address_add;

src/platform/nm-platform.c

@@ -412,6 +412,24 @@ nm_platform_link_uses_arp (int ifindex)
 	return klass->link_uses_arp (platform, ifindex);
 }
 
+gboolean
+nm_platform_link_supports_carrier_detect (int ifindex)
+{
+	g_return_val_if_fail (ifindex >= 0, FALSE);
+	g_return_val_if_fail (klass->link_supports_carrier_detect, FALSE);
+
+	return klass->link_supports_carrier_detect (platform, ifindex);
+}
+
+gboolean
+nm_platform_link_supports_vlans (int ifindex)
+{
+	g_return_val_if_fail (ifindex >= 0, FALSE);
+	g_return_val_if_fail (klass->link_supports_vlans, FALSE);
+
+	return klass->link_supports_vlans (platform, ifindex);
+}
+
 /**
  * nm_platform_link_set_up:
  * @ifindex: Interface index

src/platform/nm-platform.h

@@ -136,6 +136,9 @@ typedef struct {
 	gboolean (*link_is_connected) (NMPlatform *, int ifindex);
 	gboolean (*link_uses_arp) (NMPlatform *, int ifindex);
 
+	gboolean (*link_supports_carrier_detect) (NMPlatform *, int ifindex);
+	gboolean (*link_supports_vlans) (NMPlatform *, int ifindex);
+
 	GArray * (*ip4_address_get_all) (NMPlatform *, int ifindex);
 	GArray * (*ip6_address_get_all) (NMPlatform *, int ifindex);
 	gboolean (*ip4_address_add) (NMPlatform *, int ifindex, in_addr_t address, int plen);
@@ -228,6 +231,9 @@ gboolean nm_platform_link_is_up (int ifindex);
 gboolean nm_platform_link_is_connected (int ifindex);
 gboolean nm_platform_link_uses_arp (int ifindex);
 
+gboolean nm_platform_link_supports_carrier_detect (int ifindex);
+gboolean nm_platform_link_supports_vlans (int ifindex);
+
 GArray *nm_platform_ip4_address_get_all (int ifindex);
 GArray *nm_platform_ip6_address_get_all (int ifindex);
 gboolean nm_platform_ip4_address_add (int ifindex, in_addr_t address, int plen);

src/platform/tests/dump.c

@@ -48,6 +48,11 @@ dump_interface (NMPlatformLink *link)
 		printf (" noarp");
 	printf ("\n");
 
+	if (nm_platform_link_supports_carrier_detect (link->ifindex))
+		printf ("    feature carrier-detect\n");
+	if (nm_platform_link_supports_vlans (link->ifindex))
+		printf ("    feature vlans\n");
+
 	ip4_addresses = nm_platform_ip4_address_get_all (link->ifindex);
 	ip6_addresses = nm_platform_ip6_address_get_all (link->ifindex);
 

src/platform/tests/test-link.c

@@ -78,6 +78,11 @@ test_bogus(void)
 	error (NM_PLATFORM_ERROR_NOT_FOUND);
 	g_assert (!nm_platform_link_uses_arp (BOGUS_IFINDEX));
 	error (NM_PLATFORM_ERROR_NOT_FOUND);
+
+	g_assert (!nm_platform_link_supports_carrier_detect (BOGUS_IFINDEX));
+	error (NM_PLATFORM_ERROR_NOT_FOUND);
+	g_assert (!nm_platform_link_supports_vlans (BOGUS_IFINDEX));
+	error (NM_PLATFORM_ERROR_NOT_FOUND);
 }
 
 static void
@@ -87,6 +92,9 @@ test_loopback (void)
 	g_assert (nm_platform_link_get_type (LO_INDEX) == NM_LINK_TYPE_LOOPBACK);
 	g_assert (nm_platform_link_get_ifindex (LO_NAME) == LO_INDEX);
 	g_assert (!g_strcmp0 (nm_platform_link_get_name (LO_INDEX), LO_NAME));
+
+	g_assert (nm_platform_link_supports_carrier_detect (LO_INDEX));
+	g_assert (!nm_platform_link_supports_vlans (LO_INDEX));
 }
 
 static void
@@ -138,6 +146,10 @@ test_internal (void)
 	g_assert (!nm_platform_link_uses_arp (ifindex));
 	accept_signal (link_changed);
 
+	/* Features */
+	g_assert (!nm_platform_link_supports_carrier_detect (ifindex));
+	g_assert (nm_platform_link_supports_vlans (ifindex));
+
 	/* Delete device */
 	g_assert (nm_platform_link_delete (ifindex));
 	no_error ();