get_rtaddrs.c 1.52 KB
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/*
 * Copyright (c) 2000-2002 University of Utah and the Flux Group.
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 * 
 * {{{EMULAB-LICENSE
 * 
 * This file is part of the Emulab network testbed software.
 * 
 * This file is free software: you can redistribute it and/or modify it
 * under the terms of the GNU Affero General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or (at
 * your option) any later version.
 * 
 * This file is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Affero General Public
 * License for more details.
 * 
 * You should have received a copy of the GNU Affero General Public License
 * along with this file.  If not, see <http://www.gnu.org/licenses/>.
 * 
 * }}}
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 */

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/* 
 * This is a very slightly modified version of
 * example code from Unix Netwok Programming, edition 2.
 */

#include "discvr.h"

/*
 * Round up 'a' to next multiple of 'size'
 */
#define ROUNDUP(a, size) (((a) & ((size)-1)) ? (1 + ((a) | ((size)-1))) : (a))

/*
 * Step to next socket address structure;
 * if sa_len is 0, assume it is sizeof(u_long).
 */
#define NEXT_SA(ap)	ap = (struct sockaddr *) \
	((caddr_t) ap + (ap->sa_len ? ROUNDUP(ap->sa_len, sizeof (u_long)) : \
	sizeof(u_long)))

void
get_rtaddrs(int addrs, struct sockaddr *sa, struct sockaddr **rti_info)
{
	int		i;

	for (i = 0; i < RTAX_MAX; i++) {
		if (addrs & (1 << i)) {
			rti_info[i] = sa;
			NEXT_SA(sa);
		} else
			rti_info[i] = NULL;
	}
}