dhclient: read DUID from leasefiles

src/dhcp-manager/nm-dhcp-dhclient-utils.c

@@ -328,3 +328,39 @@ error:
 	return NULL;
 }
 
+#define DUID_PREFIX "default-duid \""
+
+GByteArray *
+nm_dhcp_dhclient_read_duid (const char *leasefile, GError **error)
+{
+	GByteArray *duid = NULL;
+	char *contents;
+	char **line, **split, *p, *e;
+
+	if (!g_file_test (leasefile, G_FILE_TEST_EXISTS))
+		return NULL;
+
+	if (!g_file_get_contents (leasefile, &contents, NULL, error))
+		return NULL;
+
+	split = g_strsplit_set (contents, "\n\r", -1);
+	for (line = split; line && *line && (duid == NULL); line++) {
+		p = g_strstrip (*line);
+		if (g_str_has_prefix (p, DUID_PREFIX)) {
+			p += strlen (DUID_PREFIX);
+
+			/* look for trailing "; */
+			e = p + strlen (p) - 2;
+			if (strcmp (e, "\";") != 0)
+				continue;
+			*e = '\0';
+
+			duid = nm_dhcp_dhclient_unescape_duid (p);
+		}
+	}
+	g_free (contents);
+	g_strfreev (split);
+
+	return duid;
+}
+

src/dhcp-manager/nm-dhcp-dhclient-utils.h

@@ -38,5 +38,7 @@ char *nm_dhcp_dhclient_escape_duid (const GByteArray *duid);
 
 GByteArray *nm_dhcp_dhclient_unescape_duid (const char *duid);
 
+GByteArray *nm_dhcp_dhclient_read_duid (const char *leasefile, GError **error);
+
 #endif /* NM_DHCP_DHCLIENT_UTILS_H */
 

src/dhcp-manager/nm-dhcp-dhclient.c

@@ -50,6 +50,7 @@ G_DEFINE_TYPE (NMDHCPDhclient, nm_dhcp_dhclient, NM_TYPE_DHCP_CLIENT)
 typedef struct {
 	const char *path;
 	char *conf_file;
+	const char *def_leasefile;
 	char *lease_file;
 	char *pid_file;
 } NMDHCPDhclientPrivate;
@@ -627,14 +628,75 @@ stop (NMDHCPClient *client, gboolean release, const GByteArray *duid)
 	}
 }
 
+static GByteArray *
+get_duid (NMDHCPClient *client)
+{
+	NMDHCPDhclientPrivate *priv = NM_DHCP_DHCLIENT_GET_PRIVATE (client);
+	GByteArray *duid = NULL;
+	char *leasefile;
+	GError *error = NULL;
+
+	/* Look in interface-specific leasefile first for backwards compat */
+	leasefile = get_dhclient_leasefile (nm_dhcp_client_get_iface (client),
+	                                    nm_dhcp_client_get_uuid (client),
+	                                    TRUE);
+	nm_log_dbg (LOGD_DHCP, "Looking for DHCPv6 DUID in '%s'.", leasefile);
+	duid = nm_dhcp_dhclient_read_duid (leasefile, &error);
+	g_free (leasefile);
+
+	if (error) {
+		nm_log_warn (LOGD_DHCP, "Failed to read leasefile '%s': (%d) %s",
+		             leasefile,
+		             error ? error->code : -1,
+		             error ? error->message : "(unknown)");
+		g_clear_error (&error);
+	}
+
+	if (!duid && priv->def_leasefile) {
+		/* Otherwise read the default machine-wide DUID */
+		nm_log_dbg (LOGD_DHCP, "Looking for default DHCPv6 DUID in '%s'.", priv->def_leasefile);
+		duid = nm_dhcp_dhclient_read_duid (priv->def_leasefile, &error);
+		if (error) {
+			nm_log_warn (LOGD_DHCP, "Failed to read leasefile '%s': (%d) %s",
+			             priv->def_leasefile,
+			             error ? error->code : -1,
+			             error ? error->message : "(unknown)");
+			g_clear_error (&error);
+		}
+	}
+
+	/* return our DUID, otherwise let the parent class make a default DUID */
+	return duid ? duid : NM_DHCP_CLIENT_CLASS (nm_dhcp_dhclient_parent_class)->get_duid (client);
+}
+
 /***************************************************/
 
+static const char *def_leasefiles[] = {
+	SYSCONFDIR "/dhclient6.leases",
+	LOCALSTATEDIR "/lib/dhcp/dhclient6.leases",
+	LOCALSTATEDIR "/lib/dhclient/dhclient6.leases",
+	NULL
+};
+
 static void
 nm_dhcp_dhclient_init (NMDHCPDhclient *self)
 {
 	NMDHCPDhclientPrivate *priv = NM_DHCP_DHCLIENT_GET_PRIVATE (self);
+	const char **iter = &def_leasefiles[0];
 
 	priv->path = nm_dhcp_dhclient_get_path (DHCLIENT_PATH);
+
+	while (iter && *iter) {
+		if (g_file_test (*iter, G_FILE_TEST_EXISTS)) {
+			priv->def_leasefile = *iter;
+			break;
+		}
+		iter++;
+	}
+
+	/* Fallback option */
+	if (!priv->def_leasefile)
+		priv->def_leasefile = SYSCONFDIR "/dhclient6.leases";
 }
 
 static void
@@ -663,5 +725,6 @@ nm_dhcp_dhclient_class_init (NMDHCPDhclientClass *dhclient_class)
 	client_class->ip4_start = ip4_start;
 	client_class->ip6_start = ip6_start;
 	client_class->stop = stop;
+	client_class->get_duid = get_duid;
 }