core: use dev_id when calculating the interface IPv6 IID (rh #1101809)dcbw/dev-id-rh1101809

Some device types (s390 OSA and ipvlan) can use the same link-layer address
for multiple virtual interfaces, and the kernel used the dev_id property
to differentiate these devices when constructing the IID.  NM should do
this too to prevent IID clashes.

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

3 files changed, 18 insertions, 4 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. */