rem: static int xl_get_msg_len(struct sip_msg *msg, str *res)
add: static int xl_get_msg_len(struct sip_msg *msg, str *res, str *hp, int hi)
context: static int xl_get_msg_len(struct sip_msg *msg, str *res){	int l = 0;	char *ch = NULL;	if(msg==NULL || res==NULL)		return -1;	ch = int2str(msg->len, &l);	res->s = ch;	res->len = l;	return 0;}