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106 lines
3.1 KiB
C
106 lines
3.1 KiB
C
/*
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* dhcpcd - DHCP client daemon
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* Copyright (c) 2006-2013 Roy Marples <roy@marples.name>
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* All rights reserved
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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#include <sys/types.h>
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#include "config.h"
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#include "dhcp.h"
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#include "if-pref.h"
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#include "net.h"
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/* Interface comparer for working out ordering. */
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static int
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ifcmp(const struct interface *si, const struct interface *ti)
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{
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int sill, till;
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const struct dhcp_state *sis, *tis;
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sis = D_CSTATE(si);
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tis = D_CSTATE(ti);
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if (sis && !tis)
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return -1;
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if (!sis && tis)
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return 1;
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if (!sis && !tis)
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return 0;
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/* If one has a lease and the other not, it takes precedence. */
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if (sis->new && !tis->new)
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return -1;
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if (!sis->new && tis->new)
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return 1;
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/* If we are either, they neither have a lease, or they both have.
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* We need to check for IPv4LL and make it non-preferred. */
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if (sis->new && tis->new) {
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sill = (sis->new->cookie == htonl(MAGIC_COOKIE));
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till = (tis->new->cookie == htonl(MAGIC_COOKIE));
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if (!sill && till)
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return 1;
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if (sill && !till)
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return -1;
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}
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/* Then carrier status. */
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if (si->carrier > ti->carrier)
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return -1;
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if (si->carrier < ti->carrier)
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return 1;
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/* Finally, metric */
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if (si->metric < ti->metric)
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return -1;
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if (si->metric > ti->metric)
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return 1;
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return 0;
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}
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/* Sort the interfaces into a preferred order - best first, worst last. */
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void
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sort_interfaces(void)
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{
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struct if_head sorted;
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struct interface *ifp, *ift;
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if (ifaces == NULL ||
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(ifp = TAILQ_FIRST(ifaces)) == NULL ||
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TAILQ_NEXT(ifp, next) == NULL)
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return;
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TAILQ_INIT(&sorted);
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TAILQ_REMOVE(ifaces, ifp, next);
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TAILQ_INSERT_HEAD(&sorted, ifp, next);
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while ((ifp = TAILQ_FIRST(ifaces))) {
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TAILQ_REMOVE(ifaces, ifp, next);
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TAILQ_FOREACH(ift, &sorted, next) {
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if (ifcmp(ifp, ift) == -1) {
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TAILQ_INSERT_BEFORE(ift, ifp, next);
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break;
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}
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}
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if (ift == NULL)
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TAILQ_INSERT_TAIL(&sorted, ifp, next);
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}
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TAILQ_CONCAT(ifaces, &sorted, next);
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}
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