diff options
Diffstat (limited to 'dhcpcd/if-pref.c')
-rw-r--r-- | dhcpcd/if-pref.c | 105 |
1 files changed, 105 insertions, 0 deletions
diff --git a/dhcpcd/if-pref.c b/dhcpcd/if-pref.c new file mode 100644 index 00000000..60a5b12f --- /dev/null +++ b/dhcpcd/if-pref.c @@ -0,0 +1,105 @@ +/* + * dhcpcd - DHCP client daemon + * Copyright (c) 2006-2013 Roy Marples <roy@marples.name> + * All rights reserved + + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#include <sys/types.h> + +#include "config.h" +#include "dhcp.h" +#include "if-pref.h" +#include "net.h" + +/* Interface comparer for working out ordering. */ +static int +ifcmp(const struct interface *si, const struct interface *ti) +{ + int sill, till; + const struct dhcp_state *sis, *tis; + + sis = D_CSTATE(si); + tis = D_CSTATE(ti); + if (sis && !tis) + return -1; + if (!sis && tis) + return 1; + if (!sis && !tis) + return 0; + /* If one has a lease and the other not, it takes precedence. */ + if (sis->new && !tis->new) + return -1; + if (!sis->new && tis->new) + return 1; + /* If we are either, they neither have a lease, or they both have. + * We need to check for IPv4LL and make it non-preferred. */ + if (sis->new && tis->new) { + sill = (sis->new->cookie == htonl(MAGIC_COOKIE)); + till = (tis->new->cookie == htonl(MAGIC_COOKIE)); + if (!sill && till) + return 1; + if (sill && !till) + return -1; + } + /* Then carrier status. */ + if (si->carrier > ti->carrier) + return -1; + if (si->carrier < ti->carrier) + return 1; + /* Finally, metric */ + if (si->metric < ti->metric) + return -1; + if (si->metric > ti->metric) + return 1; + return 0; +} + +/* Sort the interfaces into a preferred order - best first, worst last. */ +void +sort_interfaces(void) +{ + struct if_head sorted; + struct interface *ifp, *ift; + + if (ifaces == NULL || + (ifp = TAILQ_FIRST(ifaces)) == NULL || + TAILQ_NEXT(ifp, next) == NULL) + return; + + TAILQ_INIT(&sorted); + TAILQ_REMOVE(ifaces, ifp, next); + TAILQ_INSERT_HEAD(&sorted, ifp, next); + while ((ifp = TAILQ_FIRST(ifaces))) { + TAILQ_REMOVE(ifaces, ifp, next); + TAILQ_FOREACH(ift, &sorted, next) { + if (ifcmp(ifp, ift) == -1) { + TAILQ_INSERT_BEFORE(ift, ifp, next); + break; + } + } + if (ift == NULL) + TAILQ_INSERT_TAIL(&sorted, ifp, next); + } + TAILQ_CONCAT(ifaces, &sorted, next); +} |