bind/lib/isc/netscope.c

/*
 * Copyright (C) 1996-2001  Internet Software Consortium.
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM
 * DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL
 * INTERNET SOFTWARE CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT,
 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING
 * FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
 * NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
 * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#if defined(LIBC_SCCS) && !defined(lint)
static char rcsid[] =
	"$Id: netscope.c,v 1.3 2002/10/28 02:23:53 marka Exp $";
#endif /* LIBC_SCCS and not lint */

#include <isc/string.h>
#include <isc/net.h>
#include <isc/netscope.h>
#include <isc/result.h>

isc_result_t
isc_netscope_pton(int af, char *scopename, char *addr, isc_uint32_t *zoneid) {
	char *ep;
	unsigned int ifid;
	struct in6_addr *in6;
	isc_uint32_t zone;
	isc_uint64_t llz;

	/* at this moment, we only support AF_INET6 */
	if (af != AF_INET6)
		return (ISC_R_FAILURE);

	in6 = (struct in6_addr *)addr;

	/*
	 * Basically, "names" are more stable than numeric IDs in terms of
	 * renumbering, and are more preferred.  However, since there is no
	 * standard naming convention and APIs to deal with the names.  Thus,
	 * we only handle the case of link-local addresses, for which we use
	 * interface names as link names, assuming one to one mapping between
	 * interfaces and links.
	 */
	if (IN6_IS_ADDR_LINKLOCAL(in6) &&
	    (ifid = if_nametoindex((const char *)scopename)) != 0)
		zone = (isc_uint32_t)ifid;
	else {
		llz = isc_string_touint64(scopename, &ep, 10);
		if (ep == scopename)
			return (ISC_R_FAILURE);

		/* check overflow */
		zone = (isc_uint32_t)(llz & 0xffffffffUL);
		if (zone != llz)
			return (ISC_R_FAILURE);
	}

	*zoneid = zone;
	return (ISC_R_SUCCESS);
}