rpc: Report PID of restore task on setup-namespaces script

This is the first time restorer gets info back from CRIU
service. At that time it makes perfect sense to report
what PID we're working with.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

cr-service.c

@@ -125,6 +125,16 @@ int send_criu_rpc_script(char *script, int fd)
 	msg.notify = &cn;
 	cn.script = script;
 
+	if (!strcmp(script, "setup-namespaces")) {
+		/*
+		 * FIXME pid is required only once on
+		 * restore. Need some more sane way of
+		 * checking this.
+		 */
+		cn.has_pid = true;
+		cn.pid = root_item->pid.real;
+	}
+
 	ret = send_criu_msg(fd, &msg);
 	if (ret < 0)
 		return ret;

protobuf/rpc.proto

@@ -39,6 +39,7 @@ message criu_restore_resp {
 
 message criu_notify {
 	optional string script		= 1;
+	optional int32	pid		= 2;
 }
 
 enum criu_req_type {