'Check all input params'

def check_params(self):

    if (not self.session_name):
        self.module.fail_json(msg='Error:    Missing    required    arguments:    session_name.')
    if self.session_name:
        if ((len(self.session_name) < 1) or (len(self.session_name) > 15)):
            self.module.fail_json(msg='Error:    Session    name    is    invalid.')
    if self.out_if_name:
        if (not get_interface_type(self.out_if_name)):
            self.module.fail_json(msg='Error:    Session    out_if_name    is    invalid.')
    if self.dest_addr:
        if (not check_ip_addr(self.dest_addr)):
            self.module.fail_json(msg='Error:    Session    dest_addr    is    invalid.')
    if self.src_addr:
        if (not check_ip_addr(self.src_addr)):
            self.module.fail_json(msg='Error:    Session    src_addr    is    invalid.')
    if self.vrf_name:
        if (not is_valid_ip_vpn(self.vrf_name)):
            self.module.fail_json(msg='Error:    Session    vrf_name    is    invalid.')
        if (not self.dest_addr):
            self.module.fail_json(msg='Error:    vrf_name    and    dest_addr    must    set    at    the    same    time.')
    if (self.use_default_ip and (not self.out_if_name)):
        self.module.fail_json(msg='Error:    use_default_ip    and    out_if_name    must    set    at    the    same    time.')
