view libutil/nanp_valid.c @ 78:72b7d85d6354

sip-in: retransmission error handling
author Mychaela Falconia <falcon@freecalypso.org>
date Tue, 20 Sep 2022 18:00:56 -0800
parents b1c364729a93
children 81958b35f74d
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/*
 * Utility functions for NANP number validation.
 */

is_nanp_valid_prefix(s)
	char *s;
{
	/* validate NPA part */
	if (s[0] < '2')
		return(0);
	if (s[1] == '1' && s[2] == '1')
		return(0);
	if (s[1] == '9')
		return(0);
	/* validate exchange part */
	if (s[3] < '2')
		return(0);
	if (s[4] == '1' && s[5] == '1')
		return(0);
	/* all checks passed */
	return(1);
}