merge: use dev_id when constructing interface identifiers (rh #1101809)

Some devices (s390 and ipvlan) use the same MAC address for
different interfaces, but dev_id differentiates them.  So we
must use dev_id to avoid IID conflicts.

https://bugzilla.redhat.com/show_bug.cgi?id=1101809

7 files changed, 85 insertions, 6 deletions

diff --git a/src/NetworkManagerUtils.c b/src/NetworkManagerUtils.c
index 57f817649e..f28b783e58 100644
--- a/src/NetworkManagerUtils.c
+++ b/src/NetworkManagerUtils.c
@@ -2351,6 +2351,7 @@ get_gre_eui64_u_bit (guint32 addr)
  * @link_type: the hardware link type
  * @hwaddr: the hardware address of the interface
  * @hwaddr_len: the length (in bytes) of @hwaddr
+ * @dev_id: the device identifier, if any
  * @out_iid: on success, filled with the interface identifier; on failure
  * zeroed out
  *
@@ -2365,6 +2366,7 @@ gboolean
 nm_utils_get_ipv6_interface_identifier (NMLinkType link_type,
                                         const guint8 *hwaddr,
                                         guint hwaddr_len,
+                                        guint dev_id,
                                         NMUtilsIPv6IfaceId *out_iid)
 {
 	guint32 addr;
@@ -2399,13 +2401,20 @@ nm_utils_get_ipv6_interface_identifier (NMLinkType link_type,
 	default:
 		if (hwaddr_len == ETH_ALEN) {
 			/* Translate 48-bit MAC address to a 64-bit Modified EUI-64.  See
-			 * http://tools.ietf.org/html/rfc4291#appendix-A
+			 * http://tools.ietf.org/html/rfc4291#appendix-A and the Linux
+			 * kernel's net/ipv6/addrconf.c::ipv6_generate_eui64() function.
 			 */
-			out_iid->id_u8[0] = hwaddr[0] ^ 0x02;
+			out_iid->id_u8[0] = hwaddr[0];
 			out_iid->id_u8[1] = hwaddr[1];
 			out_iid->id_u8[2] = hwaddr[2];
-			out_iid->id_u8[3] = 0xff;
-			out_iid->id_u8[4] = 0xfe;
+			if (dev_id) {
+				out_iid->id_u8[3] = (dev_id >> 8) & 0xff;
+				out_iid->id_u8[4] = dev_id & 0xff;
+			} else {
+				out_iid->id_u8[0] ^= 0x02;
+				out_iid->id_u8[3] = 0xff;
+				out_iid->id_u8[4] = 0xfe;
+			}
 			out_iid->id_u8[5] = hwaddr[3];
 			out_iid->id_u8[6] = hwaddr[4];
 			out_iid->id_u8[7] = hwaddr[5];
diff --git a/src/NetworkManagerUtils.h b/src/NetworkManagerUtils.h
index 23d8330a34..11dc496b4f 100644
--- a/src/NetworkManagerUtils.h
+++ b/src/NetworkManagerUtils.h
@@ -198,6 +198,7 @@ struct _NMUtilsIPv6IfaceId {
 gboolean nm_utils_get_ipv6_interface_identifier (NMLinkType link_type,
                                                  const guint8 *hwaddr,
                                                  guint len,
+                                                 guint dev_id,
                                                  NMUtilsIPv6IfaceId *out_iid);
 
 void nm_utils_ipv6_addr_set_interface_identfier (struct in6_addr *addr,
diff --git a/src/devices/nm-device.c b/src/devices/nm-device.c
index ddc213c0a4..bf10abe6c5 100644
--- a/src/devices/nm-device.c
+++ b/src/devices/nm-device.c
@@ -201,6 +201,7 @@ typedef struct {
 	char *        hw_addr;
 	guint         hw_addr_len;
 	char *        physical_port_id;
+	guint         dev_id;
 
 	NMUnmanagedFlags        unmanaged_flags;
 	gboolean                is_nm_owned; /* whether the device is a device owned and created by NM */
@@ -600,6 +601,7 @@ nm_device_set_ip_iface (NMDevice *self, const char *iface)
 static gboolean
 get_ip_iface_identifier (NMDevice *self, NMUtilsIPv6IfaceId *out_iid)
 {
+	NMDevicePrivate *priv = NM_DEVICE_GET_PRIVATE (self);
 	NMLinkType link_type;
 	const guint8 *hwaddr = NULL;
 	size_t hwaddr_len = 0;
@@ -620,6 +622,7 @@ get_ip_iface_identifier (NMDevice *self, NMUtilsIPv6IfaceId *out_iid)
 	success = nm_utils_get_ipv6_interface_identifier (link_type,
 	                                                  hwaddr,
 	                                                  hwaddr_len,
+	                                                  priv->dev_id,
 	                                                  out_iid);
 	if (!success) {
 		_LOGW (LOGD_HW, "failed to generate interface identifier "
@@ -8472,6 +8475,7 @@ constructed (GObject *object)
 	if (priv->ifindex > 0) {
 		priv->is_software = nm_platform_link_is_software (priv->ifindex);
 		priv->physical_port_id = nm_platform_link_get_physical_port_id (priv->ifindex);
+		priv->dev_id = nm_platform_link_get_dev_id (priv->ifindex);
 		priv->mtu = nm_platform_link_get_mtu (priv->ifindex);
 	}
 	/* Indicate software device in capabilities. */
diff --git a/src/platform/nm-fake-platform.c b/src/platform/nm-fake-platform.c
index 7194707b29..8288fb9fc4 100644
--- a/src/platform/nm-fake-platform.c
+++ b/src/platform/nm-fake-platform.c
@@ -488,6 +488,15 @@ link_get_physical_port_id (NMPlatform *platform, int ifindex)
 	return NULL;
 }
 
+static guint
+link_get_dev_id (NMPlatform *platform, int ifindex)
+{
+	/* We call link_get just to cause an error to be set if @ifindex is bad. */
+	link_get (platform, ifindex);
+
+	return 0;
+}
+
 static gboolean
 link_get_wake_on_lan (NMPlatform *platform, int ifindex)
 {
@@ -1406,6 +1415,7 @@ nm_fake_platform_class_init (NMFakePlatformClass *klass)
 	platform_class->link_set_mtu = link_set_mtu;
 
 	platform_class->link_get_physical_port_id = link_get_physical_port_id;
+	platform_class->link_get_dev_id = link_get_dev_id;
 	platform_class->link_get_wake_on_lan = link_get_wake_on_lan;
 
 	platform_class->link_supports_carrier_detect = link_supports_carrier_detect;
diff --git a/src/platform/nm-linux-platform.c b/src/platform/nm-linux-platform.c
index 14f791106d..76a2feb52b 100644
--- a/src/platform/nm-linux-platform.c
+++ b/src/platform/nm-linux-platform.c
@@ -2744,6 +2744,30 @@ link_get_physical_port_id (NMPlatform *platform, int ifindex)
 	return id;
 }
 
+static guint
+link_get_dev_id (NMPlatform *platform, int ifindex)
+{
+	const char *ifname;
+	gs_free char *path = NULL, *id = NULL;
+	gint64 int_val;
+
+	ifname = nm_platform_link_get_name (ifindex);
+	if (!ifname)
+		return 0;
+
+	ifname = ASSERT_VALID_PATH_COMPONENT (ifname);
+
+	path = g_strdup_printf ("/sys/class/net/%s/dev_id", ifname);
+	id = sysctl_get (platform, path);
+	if (!id || !*id)
+		return 0;
+
+	/* Value is reported as hex */
+	int_val = _nm_utils_ascii_str_to_int64 (id, 16, 0, G_MAXUINT16, 0);
+
+	return errno ? 0 : (int) int_val;
+}
+
 static int
 vlan_add (NMPlatform *platform, const char *name, int parent, int vlan_id, guint32 vlan_flags)
 {
@@ -4608,6 +4632,7 @@ nm_linux_platform_class_init (NMLinuxPlatformClass *klass)
 	platform_class->link_set_mtu = link_set_mtu;
 
 	platform_class->link_get_physical_port_id = link_get_physical_port_id;
+	platform_class->link_get_dev_id = link_get_dev_id;
 	platform_class->link_get_wake_on_lan = link_get_wake_on_lan;
 
 	platform_class->link_supports_carrier_detect = link_supports_carrier_detect;
diff --git a/src/platform/nm-platform.c b/src/platform/nm-platform.c
index d51c142e04..e4e5dbaa6a 100644
--- a/src/platform/nm-platform.c
+++ b/src/platform/nm-platform.c
@@ -1008,9 +1008,15 @@ nm_platform_link_get_mtu (int ifindex)
 }
 
 /**
- * nm_platform_link_get_mtu:
+ * nm_platform_link_get_physical_port_id:
  * @ifindex: Interface index
  *
+ * The physical port ID, if present, indicates some unique identifier of
+ * the parent interface (eg, the physical port of which this link is a child).
+ * Two links that report the same physical port ID can be assumed to be
+ * children of the same physical port and may share resources that limit
+ * their abilities.
+ *
  * Returns: physical port ID for the interface, or %NULL on error
  * or if the interface has no physical port ID.
  */
@@ -1026,6 +1032,28 @@ nm_platform_link_get_physical_port_id (int ifindex)
 }
 
 /**
+ * nm_platform_link_get_dev_id:
+ * @ifindex: Interface index
+ *
+ * In contrast to the physical device ID (which indicates which parent a
+ * child has) the device ID differentiates sibling devices that may share
+ * the same MAC address.
+ *
+ * Returns: device ID for the interface, or 0 on error or if the
+ * interface has no device ID.
+ */
+guint
+nm_platform_link_get_dev_id (int ifindex)
+{
+	reset_error ();
+
+	g_return_val_if_fail (ifindex >= 0, 0);
+	g_return_val_if_fail (klass->link_get_dev_id, 0);
+
+	return klass->link_get_dev_id (platform, ifindex);
+}
+
+/**
  * nm_platform_link_get_wake_onlan:
  * @ifindex: Interface index
  *
diff --git a/src/platform/nm-platform.h b/src/platform/nm-platform.h
index bc7b84c9ff..b90343d79f 100644
--- a/src/platform/nm-platform.h
+++ b/src/platform/nm-platform.h
@@ -373,7 +373,8 @@ typedef struct {
 	guint32 (*link_get_mtu) (NMPlatform *, int ifindex);
 	gboolean (*link_set_mtu) (NMPlatform *, int ifindex, guint32 mtu);
 
-	char * (*link_get_physical_port_id) (NMPlatform *, int ifindex);
+	char *   (*link_get_physical_port_id) (NMPlatform *, int ifindex);
+	guint    (*link_get_dev_id) (NMPlatform *, int ifindex);
 	gboolean (*link_get_wake_on_lan) (NMPlatform *, int ifindex);
 
 	gboolean (*link_supports_carrier_detect) (NMPlatform *, int ifindex);
@@ -524,6 +525,7 @@ guint32 nm_platform_link_get_mtu (int ifindex);
 gboolean nm_platform_link_set_mtu (int ifindex, guint32 mtu);
 
 char    *nm_platform_link_get_physical_port_id (int ifindex);
+guint    nm_platform_link_get_dev_id (int ifindex);
 gboolean nm_platform_link_get_wake_on_lan (int ifindex);
 
 gboolean nm_platform_link_supports_carrier_detect (int ifindex);