if.c - platform/external/dhcpcd-6.8.2 - Git at Google

 /*
  * dhcpcd - DHCP client daemon
  * Copyright (c) 2006-2015 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/param.h>
 #include <sys/types.h>
 #include <sys/ioctl.h>
 #include <sys/socket.h>

 #include <net/if.h>
 #include <net/if_arp.h>
 #include <netinet/in.h>
 #ifdef __FreeBSD__ /* Needed so that including netinet6/in6_var.h works */
 #  include <net/if_var.h>
 #endif
 #ifdef AF_LINK
 #  include <net/if_dl.h>
 #  include <net/if_types.h>
 #  include <netinet/in_var.h>
 #endif
 #ifdef AF_PACKET
 #  include <netpacket/packet.h>
 #endif
 #ifdef SIOCGIFMEDIA
 #  include <net/if_media.h>
 #endif
 #include <net/route.h>

 #include <ctype.h>
 #include <errno.h>
 #include <ifaddrs.h>
 #include <fnmatch.h>
 #include <stddef.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>

 #include "config.h"
 #include "common.h"
 #include "dev.h"
 #include "dhcp.h"
 #include "dhcp6.h"
 #include "if.h"
 #include "if-options.h"
 #include "ipv4.h"
 #include "ipv6nd.h"

 #ifdef __QNX__
 /* QNX carries defines for, but does not actually support PF_LINK */
 #undef IFLR_ACTIVE
 #endif

 int
 split_interface_lease(const char *ifname, int *interface_name_len,
 			  const char **lease_identifier)
 {
 	int ret = 0;
 	int len;
 	const char *lease_ptr = ifname;
 	const char *p = strchr(ifname, '=');

 	if (interface_name_len)
 		len = *interface_name_len;
 	else
 		len = strlen(ifname);

 	if (p) {
 		lease_ptr = p + 1;
 		if (len > p - ifname)
 			len = p - ifname;
 		ret = 1;
 	}

 	if (interface_name_len)
 		*interface_name_len = len;
 	if (lease_identifier)
 		*lease_identifier = lease_ptr;
 	return ret;
 }

 void
 if_free(struct interface *ifp)
 {

 	if (ifp == NULL)
 		return;
 	ipv4_free(ifp);
 	dhcp_free(ifp);
 	dhcp6_free(ifp);
 	ipv6nd_free(ifp);
 	ipv6_free(ifp);
 	free_options(ifp->options);
 	free(ifp);
 }

 int
 if_carrier(struct interface *iface)
 {
 	int s, r;
 	struct ifreq ifr;
 #ifdef SIOCGIFMEDIA
 	struct ifmediareq ifmr;
 #endif

 	if ((s = socket(PF_INET, SOCK_DGRAM, 0)) == -1)
 		return LINK_UNKNOWN;
 	memset(&ifr, 0, sizeof(ifr));
 	strlcpy(ifr.ifr_name, iface->name, sizeof(ifr.ifr_name));
 	if (ioctl(s, SIOCGIFFLAGS, &ifr) == -1) {
 		close(s);
 		return LINK_UNKNOWN;
 	}
 	iface->flags = (unsigned int)ifr.ifr_flags;

 #ifdef SIOCGIFMEDIA
 	memset(&ifmr, 0, sizeof(ifmr));
 	strlcpy(ifmr.ifm_name, iface->name, sizeof(ifmr.ifm_name));
 	if (ioctl(s, SIOCGIFMEDIA, &ifmr) != -1 &&
 	    ifmr.ifm_status & IFM_AVALID)
 		r = (ifmr.ifm_status & IFM_ACTIVE) ? LINK_UP : LINK_DOWN;
 	else
 		r = ifr.ifr_flags & IFF_RUNNING ? LINK_UP : LINK_UNKNOWN;
 #else
 	r = ifr.ifr_flags & IFF_RUNNING ? LINK_UP : LINK_DOWN;
 #endif
 	close(s);
 	return r;
 }

 int
 if_setflag(struct interface *ifp, short flag)
 {
 	struct ifreq ifr;
 	int s, r;

 	if ((s = socket(PF_INET, SOCK_DGRAM, 0)) == -1)
 		return -1;
 	memset(&ifr, 0, sizeof(ifr));
 	strlcpy(ifr.ifr_name, ifp->name, sizeof(ifr.ifr_name));
 	r = -1;
 	if (ioctl(s, SIOCGIFFLAGS, &ifr) == 0) {
 		if (flag == 0 || (ifr.ifr_flags & flag) == flag)
 			r = 0;
 		else {
 			ifr.ifr_flags |= flag;
 			if (ioctl(s, SIOCSIFFLAGS, &ifr) == 0)
 				r = 0;
 		}
 		ifp->flags = (unsigned int)ifr.ifr_flags;
 	}
 	close(s);
 	return r;
 }

 static int
 if_hasconf(struct dhcpcd_ctx *ctx, const char *ifname)
 {
 	int i;

 	for (i = 0; i < ctx->ifcc; i++) {
 		if (strcmp(ctx->ifcv[i], ifname) == 0)
 			return 1;
 	}
 	return 0;
 }

 static void if_learnaddrs1(struct dhcpcd_ctx *ctx, struct if_head *ifs,
     struct ifaddrs *ifaddrs)
 {
 	struct ifaddrs *ifa;
 	struct interface *ifp;
 #ifdef INET
 	const struct sockaddr_in *addr, *net, *dst;
 #endif
 #ifdef INET6
 	struct sockaddr_in6 *sin6, *net6;
 #endif
 	int ifa_flags;


 	for (ifa = ifaddrs; ifa; ifa = ifa->ifa_next) {
 		if (ifa->ifa_addr == NULL)
 			continue;
 		if ((ifp = if_find(ifs, ifa->ifa_name)) == NULL)
 			continue;
 		switch(ifa->ifa_addr->sa_family) {
 #ifdef INET
 		case AF_INET:
 			addr = (const struct sockaddr_in *)
 			    (void *)ifa->ifa_addr;
 			net = (const struct sockaddr_in *)
 			    (void *)ifa->ifa_netmask;
 			if (ifa->ifa_flags & IFF_POINTOPOINT)
 				dst = (const struct sockaddr_in *)
 				    (void *)ifa->ifa_dstaddr;
 			else
 				dst = NULL;
 			ifa_flags = if_addrflags(&addr->sin_addr, ifp);
 			ipv4_handleifa(ctx, RTM_NEWADDR, ifs, ifa->ifa_name,
 				&addr->sin_addr,
 				&net->sin_addr,
 				dst ? &dst->sin_addr : NULL, ifa_flags);
 			break;
 #endif
 #ifdef INET6
 		case AF_INET6:
 			sin6 = (struct sockaddr_in6 *)(void *)ifa->ifa_addr;
 			net6 = (struct sockaddr_in6 *)(void *)ifa->ifa_netmask;
 #ifdef __KAME__
 			if (IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr))
 				/* Remove the scope from the address */
 				sin6->sin6_addr.s6_addr[2] =
 				    sin6->sin6_addr.s6_addr[3] = '\0';
 #endif
 			ifa_flags = if_addrflags6(&sin6->sin6_addr, ifp);
 			if (ifa_flags != -1)
 				ipv6_handleifa(ctx, RTM_NEWADDR, ifs,
 				    ifa->ifa_name,
 				    &sin6->sin6_addr,
 				    ipv6_prefixlen(&net6->sin6_addr),
 				    ifa_flags);
 			break;
 #endif
 		}
 	}
 }

 struct if_head *
 if_discover(struct dhcpcd_ctx *ctx, int argc, char * const *argv)
 {
 	struct ifaddrs *ifaddrs, *ifa;
 	char *p;
 	int i;
 	struct if_head *ifs;
 	struct interface *ifp;
 	const char *lease_identifier;
 	char ifn[IF_NAMESIZE];

 #ifdef __linux__
 	char alias[IF_NAMESIZE];
 #endif

 #ifdef AF_LINK
 	const struct sockaddr_dl *sdl;
 #ifdef SIOCGIFPRIORITY
 	struct ifreq ifr;
 	int s_inet;
 #endif
 #ifdef IFLR_ACTIVE
 	struct if_laddrreq iflr;
 	int s_link;
 #endif

 #ifdef SIOCGIFPRIORITY
 	if ((s_inet = socket(PF_INET, SOCK_DGRAM, 0)) == -1)
 		return NULL;
 #endif
 #ifdef IFLR_ACTIVE
 	if ((s_link = socket(PF_LINK, SOCK_DGRAM, 0)) == -1) {
 #ifdef SIOCGIFPRIORITY
 		close(s_inet);
 #endif
 		return NULL;
 	}
 	memset(&iflr, 0, sizeof(iflr));
 #endif
 #elif AF_PACKET
 	const struct sockaddr_ll *sll;
 #endif

 	if (getifaddrs(&ifaddrs) == -1)
 		return NULL;
 	ifs = malloc(sizeof(*ifs));
 	if (ifs == NULL)
 		return NULL;
 	TAILQ_INIT(ifs);

 	for (ifa = ifaddrs; ifa; ifa = ifa->ifa_next) {
 		if (ifa->ifa_addr != NULL) {
 #ifdef AF_LINK
 			if (ifa->ifa_addr->sa_family != AF_LINK)
 				continue;
 #elif AF_PACKET
 			if (ifa->ifa_addr->sa_family != AF_PACKET)
 				continue;
 #endif
 		}

 		/* It's possible for an interface to have >1 AF_LINK.
 		 * For our purposes, we use the first one. */
 		TAILQ_FOREACH(ifp, ifs, next) {
 			if (strcmp(ifp->name, ifa->ifa_name) == 0)
 				break;
 		}
 		if (ifp)
 			continue;

 		lease_identifier = NULL;
 		if (argc > 0) {
 			for (i = 0; i < argc; i++) {
 				int intf_len = strlen(argv[i]);
 				split_interface_lease(argv[i], &intf_len,
 						      &lease_identifier);
 				if (intf_len > IF_NAMESIZE)
 					continue;
 				strlcpy(ifn, argv[i], intf_len + 1);
 #ifdef __linux__
 				strlcpy(alias, argv[i], intf_len + 1);
 				/* Check the real interface name */
 				p = strchr(ifn, ':');
 				if (p)
 					*p = '\0';
 #endif
 				if (strcmp(ifn, ifa->ifa_name) == 0)
 					break;
 			}
 			if (i == argc)
 				continue;
 		} else {
 			strlcpy(ifn, ifa->ifa_name, sizeof(ifn));
 #ifdef __linux
 			strlcpy(alias, ifa->ifa_name, sizeof(alias));
 #endif
 			/* -1 means we're discovering against a specific
 			 * interface, but we still need the below rules
 			 * to apply. */
 			if (argc == -1 && strcmp(argv[0], ifa->ifa_name) != 0)
 				continue;
 		}
 		p = ifn;

 		for (i = 0; i < ctx->ifdc; i++)
 			if (!fnmatch(ctx->ifdv[i], p, 0))
 				break;
 		if (i < ctx->ifdc)
 			continue;
 		for (i = 0; i < ctx->ifac; i++)
 			if (!fnmatch(ctx->ifav[i], p, 0))
 				break;
 		if (ctx->ifac && i == ctx->ifac)
 			continue;

 		/* Ensure that the interface name has settled */
 		if (!dev_initialized(ctx, p))
 			continue;

 		/* Don't allow loopback or pointopoint unless explicit */
 		if (ifa->ifa_flags & (IFF_LOOPBACK | IFF_POINTOPOINT)) {
 			if ((argc == 0 || argc == -1) &&
 			    ctx->ifac == 0 && !if_hasconf(ctx, p))
 				continue;
 		}

 		if (if_vimaster(p) == 1) {
 			logger(ctx, argc ? LOG_ERR : LOG_DEBUG,
 			    "%s: is a Virtual Interface Master, skipping", p);
 			continue;
 		}

 		ifp = calloc(1, sizeof(*ifp));
 		if (ifp == NULL) {
 			logger(ctx, LOG_ERR, "%s: %m", __func__);
 			break;
 		}
 		ifp->ctx = ctx;
 #ifdef __linux__
 		strlcpy(ifp->alias, alias, sizeof(ifp->alias));
 #endif
 		strlcpy(ifp->name, p, sizeof(ifp->name));
 		if (lease_identifier) {
 			strlcpy(ifp->lease_identifier, lease_identifier,
 				sizeof(ifp->lease_identifier));
 		}
 		ifp->flags = ifa->ifa_flags;
 		ifp->carrier = if_carrier(ifp);

 		if (ifa->ifa_addr != NULL) {
 #ifdef AF_LINK
 			sdl = (const struct sockaddr_dl *)(void *)ifa->ifa_addr;

 #ifdef IFLR_ACTIVE
 			/* We need to check for active address */
 			strlcpy(iflr.iflr_name, ifp->name,
 			    sizeof(iflr.iflr_name));
 			memcpy(&iflr.addr, ifa->ifa_addr,
 			    MIN(ifa->ifa_addr->sa_len, sizeof(iflr.addr)));
 			iflr.flags = IFLR_PREFIX;
 			iflr.prefixlen = (unsigned int)sdl->sdl_alen * NBBY;
 			if (ioctl(s_link, SIOCGLIFADDR, &iflr) == -1 ||
 			    !(iflr.flags & IFLR_ACTIVE))
 			{
 				if_free(ifp);
 				continue;
 			}
 #endif

 			ifp->index = sdl->sdl_index;
 			switch(sdl->sdl_type) {
 #ifdef IFT_BRIDGE
 			case IFT_BRIDGE: /* FALLTHROUGH */
 #endif
 #ifdef IFT_PPP
 			case IFT_PPP: /* FALLTHROUGH */
 #endif
 #ifdef IFT_PROPVIRTUAL
 			case IFT_PROPVIRTUAL: /* FALLTHROUGH */
 #endif
 #if defined(IFT_BRIDGE) || defined(IFT_PPP) || defined(IFT_PROPVIRTUAL)
 				/* Don't allow unless explicit */
 				if ((argc == 0 || argc == -1) &&
 				    ctx->ifac == 0 &&
 				    !if_hasconf(ctx, ifp->name))
 				{
 					logger(ifp->ctx, LOG_DEBUG,
 					    "%s: ignoring due to"
 					    " interface type and"
 					    " no config",
 					    ifp->name);
 					if_free(ifp);
 					continue;
 				}
 				/* FALLTHROUGH */
 #endif
 #ifdef IFT_L2VLAN
 			case IFT_L2VLAN: /* FALLTHROUGH */
 #endif
 #ifdef IFT_L3IPVLAN
 			case IFT_L3IPVLAN: /* FALLTHROUGH */
 #endif
 			case IFT_ETHER:
 				ifp->family = ARPHRD_ETHER;
 				break;
 #ifdef IFT_IEEE1394
 			case IFT_IEEE1394:
 				ifp->family = ARPHRD_IEEE1394;
 				break;
 #endif
 #ifdef IFT_INFINIBAND
 			case IFT_INFINIBAND:
 				ifp->family = ARPHRD_INFINIBAND;
 				break;
 #endif
 			default:
 				/* Don't allow unless explicit */
 				if ((argc == 0 || argc == -1) &&
 				    ctx->ifac == 0 &&
 				    !if_hasconf(ctx, ifp->name))
 				{
 					if_free(ifp);
 					continue;
 				}
 				logger(ifp->ctx, LOG_WARNING,
 				    "%s: unsupported interface type %.2x",
 				    ifp->name, sdl->sdl_type);
 				/* Pretend it's ethernet */
 				ifp->family = ARPHRD_ETHER;
 				break;
 			}
 			ifp->hwlen = sdl->sdl_alen;
 #ifndef CLLADDR
 #  define CLLADDR(s) ((const char *)((s)->sdl_data + (s)->sdl_nlen))
 #endif
 			memcpy(ifp->hwaddr, CLLADDR(sdl), ifp->hwlen);
 #elif AF_PACKET
 			sll = (const struct sockaddr_ll *)(void *)ifa->ifa_addr;
 			ifp->index = (unsigned int)sll->sll_ifindex;
 			ifp->family = sll->sll_hatype;
 			ifp->hwlen = sll->sll_halen;
 			if (ifp->hwlen != 0)
 				memcpy(ifp->hwaddr, sll->sll_addr, ifp->hwlen);
 #endif
 		}
 #ifdef __linux__
 		/* PPP addresses on Linux don't have hardware addresses */
 		else
 			ifp->index = if_nametoindex(ifp->name);
 #endif

 		/* We only work on ethernet by default */
 		if (ifp->family != ARPHRD_ETHER) {
 			if ((argc == 0 || argc == -1) &&
 			    ctx->ifac == 0 && !if_hasconf(ctx, ifp->name))
 			{
 				if_free(ifp);
 				continue;
 			}
 			switch (ifp->family) {
 			case ARPHRD_IEEE1394:
 			case ARPHRD_INFINIBAND:
 #ifdef ARPHRD_LOOPBACK
 			case ARPHRD_LOOPBACK:
 #endif
 #ifdef ARPHRD_PPP
 			case ARPHRD_PPP:
 #endif
 				/* We don't warn for supported families */
 				break;

 /* IFT already checked */
 #ifndef AF_LINK
 			default:
 				logger(ifp->ctx, LOG_WARNING,
 				    "%s: unsupported interface family %.2x",
 				    ifp->name, ifp->family);
 				break;
 #endif
 			}
 		}

 		/* Handle any platform init for the interface */
 		if (if_init(ifp) == -1) {
 			logger(ifp->ctx, LOG_ERR, "%s: if_init: %m", p);
 			if_free(ifp);
 			continue;
 		}

 		/* Ensure that the MTU is big enough for DHCP */
 		if (if_getmtu(ifp->name) < MTU_MIN &&
 		    if_setmtu(ifp->name, MTU_MIN) == -1)
 		{
 			logger(ifp->ctx, LOG_ERR, "%s: set_mtu: %m", p);
 			if_free(ifp);
 			continue;
 		}

 #ifdef SIOCGIFPRIORITY
 		/* Respect the interface priority */
 		memset(&ifr, 0, sizeof(ifr));
 		strlcpy(ifr.ifr_name, ifp->name, sizeof(ifr.ifr_name));
 		if (ioctl(s_inet, SIOCGIFPRIORITY, &ifr) == 0)
 			ifp->metric = ifr.ifr_metric;
 #else
 		/* We reserve the 100 range for virtual interfaces, if and when
 		 * we can work them out. */
 		ifp->metric = 200 + ifp->index;
 		if (if_getssid(ifp) != -1) {
 			ifp->wireless = 1;
 			ifp->metric += 100;
 		}
 #endif

 		TAILQ_INSERT_TAIL(ifs, ifp, next);
 	}

 	if (!ifs) {
 		logger(ctx, LOG_INFO, "%s: no matching interfaces", __func__);
 		for (ifa = ifaddrs; ifa; ifa = ifa->ifa_next) {
 			logger(ctx, LOG_INFO, "%s: considered %s",
 			       __func__, ifa->ifa_name);
 		}
 	}

 	if_learnaddrs1(ctx, ifs, ifaddrs);
 	freeifaddrs(ifaddrs);

 #ifdef SIOCGIFPRIORITY
 	close(s_inet);
 #endif
 #ifdef IFLR_ACTIVE
 	close(s_link);
 #endif

 	return ifs;
 }

 static struct interface *
 if_findindexname(struct if_head *ifaces, unsigned int idx, const char *name)
 {

 	if (ifaces != NULL) {
 		struct interface *ifp;

 		TAILQ_FOREACH(ifp, ifaces, next) {
 			if ((ifp->options == NULL ||
 			    !(ifp->options->options & DHCPCD_PFXDLGONLY)) &&
 			    ((name && strcmp(ifp->name, name) == 0) ||
 #ifdef __linux__
 			    (name && strcmp(ifp->alias, name) == 0) ||
 #endif
 			    (!name && ifp->index == idx)))
 				return ifp;
 		}
 	}

 	errno = ESRCH;
 	return NULL;
 }

 struct interface *
 if_find(struct if_head *ifaces, const char *name)
 {

 	return if_findindexname(ifaces, 0, name);
 }

 struct interface *
 if_findindex(struct if_head *ifaces, unsigned int idx)
 {

 	return if_findindexname(ifaces, idx, NULL);
 }

 int
 if_domtu(const char *ifname, short int mtu)
 {
 	int s, r;
 	struct ifreq ifr;

 	if ((s = socket(PF_INET, SOCK_DGRAM, 0)) == -1)
 		return -1;
 	memset(&ifr, 0, sizeof(ifr));
 	strlcpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name));
 	ifr.ifr_mtu = mtu;
 	r = ioctl(s, mtu ? SIOCSIFMTU : SIOCGIFMTU, &ifr);
 	close(s);
 	if (r == -1)
 		return -1;
 	return ifr.ifr_mtu;
 }

 /* Interface comparer for working out ordering. */
 static int
 if_cmp(const struct interface *si, const struct interface *ti)
 {
 #ifdef INET
 	int r;
 #endif

 	/* Always prefer master interfaces */
 	if (!(si->options->options & DHCPCD_PFXDLGONLY) &&
 	    ti->options->options & DHCPCD_PFXDLGONLY)
 		return -1;
 	if (si->options->options & DHCPCD_PFXDLGONLY &&
 	    !(ti->options->options & DHCPCD_PFXDLGONLY))
 		return 1;

 	/* Check carrier status first */
 	if (si->carrier > ti->carrier)
 		return -1;
 	if (si->carrier < ti->carrier)
 		return 1;

 	if (D_STATE_RUNNING(si) && !D_STATE_RUNNING(ti))
 		return -1;
 	if (!D_STATE_RUNNING(si) && D_STATE_RUNNING(ti))
 		return 1;
 	if (RS_STATE_RUNNING(si) && !RS_STATE_RUNNING(ti))
 		return -1;
 	if (!RS_STATE_RUNNING(si) && RS_STATE_RUNNING(ti))
 		return 1;
 	if (D6_STATE_RUNNING(si) && !D6_STATE_RUNNING(ti))
 		return -1;
 	if (!D6_STATE_RUNNING(si) && D6_STATE_RUNNING(ti))
 		return 1;

 #ifdef INET
 	/* Special attention needed here due to states and IPv4LL. */
 	if ((r = ipv4_ifcmp(si, ti)) != 0)
 		return r;
 #endif

 	/* 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
 if_sortinterfaces(struct dhcpcd_ctx *ctx)
 {
 	struct if_head sorted;
 	struct interface *ifp, *ift;

 	if (ctx->ifaces == NULL ||
 	    (ifp = TAILQ_FIRST(ctx->ifaces)) == NULL ||
 	    TAILQ_NEXT(ifp, next) == NULL)
 		return;

 	TAILQ_INIT(&sorted);
 	TAILQ_REMOVE(ctx->ifaces, ifp, next);
 	TAILQ_INSERT_HEAD(&sorted, ifp, next);
 	while ((ifp = TAILQ_FIRST(ctx->ifaces))) {
 		TAILQ_REMOVE(ctx->ifaces, ifp, next);
 		TAILQ_FOREACH(ift, &sorted, next) {
 			if (if_cmp(ifp, ift) == -1) {
 				TAILQ_INSERT_BEFORE(ift, ifp, next);
 				break;
 			}
 		}
 		if (ift == NULL)
 			TAILQ_INSERT_TAIL(&sorted, ifp, next);
 	}
 	TAILQ_CONCAT(ctx->ifaces, &sorted, next);
 }
	/*
	* dhcpcd - DHCP client daemon
	* Copyright (c) 2006-2015 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/param.h>
	#include <sys/types.h>
	#include <sys/ioctl.h>
	#include <sys/socket.h>

	#include <net/if.h>
	#include <net/if_arp.h>
	#include <netinet/in.h>
	#ifdef __FreeBSD__ /* Needed so that including netinet6/in6_var.h works */
	# include <net/if_var.h>
	#endif
	#ifdef AF_LINK
	# include <net/if_dl.h>
	# include <net/if_types.h>
	# include <netinet/in_var.h>
	#endif
	#ifdef AF_PACKET
	# include <netpacket/packet.h>
	#endif
	#ifdef SIOCGIFMEDIA
	# include <net/if_media.h>
	#endif
	#include <net/route.h>

	#include <ctype.h>
	#include <errno.h>
	#include <ifaddrs.h>
	#include <fnmatch.h>
	#include <stddef.h>
	#include <stdio.h>
	#include <stdlib.h>
	#include <string.h>
	#include <unistd.h>

	#include "config.h"
	#include "common.h"
	#include "dev.h"
	#include "dhcp.h"
	#include "dhcp6.h"
	#include "if.h"
	#include "if-options.h"
	#include "ipv4.h"
	#include "ipv6nd.h"

	#ifdef __QNX__
	/* QNX carries defines for, but does not actually support PF_LINK */
	#undef IFLR_ACTIVE
	#endif

	int
	split_interface_lease(const char ifname, int interface_name_len,
	const char **lease_identifier)
	{
	int ret = 0;
	int len;
	const char *lease_ptr = ifname;
	const char *p = strchr(ifname, '=');

	if (interface_name_len)
	len = *interface_name_len;
	else
	len = strlen(ifname);

	if (p) {
	lease_ptr = p + 1;
	if (len > p - ifname)
	len = p - ifname;
	ret = 1;
	}

	if (interface_name_len)
	*interface_name_len = len;
	if (lease_identifier)
	*lease_identifier = lease_ptr;
	return ret;
	}

	void
	if_free(struct interface *ifp)
	{

	if (ifp == NULL)
	return;
	ipv4_free(ifp);
	dhcp_free(ifp);
	dhcp6_free(ifp);
	ipv6nd_free(ifp);
	ipv6_free(ifp);
	free_options(ifp->options);
	free(ifp);
	}

	int
	if_carrier(struct interface *iface)
	{
	int s, r;
	struct ifreq ifr;
	#ifdef SIOCGIFMEDIA
	struct ifmediareq ifmr;
	#endif

	if ((s = socket(PF_INET, SOCK_DGRAM, 0)) == -1)
	return LINK_UNKNOWN;
	memset(&ifr, 0, sizeof(ifr));
	strlcpy(ifr.ifr_name, iface->name, sizeof(ifr.ifr_name));
	if (ioctl(s, SIOCGIFFLAGS, &ifr) == -1) {
	close(s);
	return LINK_UNKNOWN;
	}
	iface->flags = (unsigned int)ifr.ifr_flags;

	#ifdef SIOCGIFMEDIA
	memset(&ifmr, 0, sizeof(ifmr));
	strlcpy(ifmr.ifm_name, iface->name, sizeof(ifmr.ifm_name));
	if (ioctl(s, SIOCGIFMEDIA, &ifmr) != -1 &&
	ifmr.ifm_status & IFM_AVALID)
	r = (ifmr.ifm_status & IFM_ACTIVE) ? LINK_UP : LINK_DOWN;
	else
	r = ifr.ifr_flags & IFF_RUNNING ? LINK_UP : LINK_UNKNOWN;
	#else
	r = ifr.ifr_flags & IFF_RUNNING ? LINK_UP : LINK_DOWN;
	#endif
	close(s);
	return r;
	}

	int
	if_setflag(struct interface *ifp, short flag)
	{
	struct ifreq ifr;
	int s, r;

	if ((s = socket(PF_INET, SOCK_DGRAM, 0)) == -1)
	return -1;
	memset(&ifr, 0, sizeof(ifr));
	strlcpy(ifr.ifr_name, ifp->name, sizeof(ifr.ifr_name));
	r = -1;
	if (ioctl(s, SIOCGIFFLAGS, &ifr) == 0) {
	if (flag == 0 \|\| (ifr.ifr_flags & flag) == flag)
	r = 0;
	else {
	ifr.ifr_flags \|= flag;
	if (ioctl(s, SIOCSIFFLAGS, &ifr) == 0)
	r = 0;
	}
	ifp->flags = (unsigned int)ifr.ifr_flags;
	}
	close(s);
	return r;
	}

	static int
	if_hasconf(struct dhcpcd_ctx ctx, const char ifname)
	{
	int i;

	for (i = 0; i < ctx->ifcc; i++) {
	if (strcmp(ctx->ifcv[i], ifname) == 0)
	return 1;
	}
	return 0;
	}

	static void if_learnaddrs1(struct dhcpcd_ctx ctx, struct if_head ifs,
	struct ifaddrs *ifaddrs)
	{
	struct ifaddrs *ifa;
	struct interface *ifp;
	#ifdef INET
	const struct sockaddr_in addr, net, *dst;
	#endif
	#ifdef INET6
	struct sockaddr_in6 sin6, net6;
	#endif
	int ifa_flags;


	for (ifa = ifaddrs; ifa; ifa = ifa->ifa_next) {
	if (ifa->ifa_addr == NULL)
	continue;
	if ((ifp = if_find(ifs, ifa->ifa_name)) == NULL)
	continue;
	switch(ifa->ifa_addr->sa_family) {
	#ifdef INET
	case AF_INET:
	addr = (const struct sockaddr_in *)
	(void *)ifa->ifa_addr;
	net = (const struct sockaddr_in *)
	(void *)ifa->ifa_netmask;
	if (ifa->ifa_flags & IFF_POINTOPOINT)
	dst = (const struct sockaddr_in *)
	(void *)ifa->ifa_dstaddr;
	else
	dst = NULL;
	ifa_flags = if_addrflags(&addr->sin_addr, ifp);
	ipv4_handleifa(ctx, RTM_NEWADDR, ifs, ifa->ifa_name,
	&addr->sin_addr,
	&net->sin_addr,
	dst ? &dst->sin_addr : NULL, ifa_flags);
	break;
	#endif
	#ifdef INET6
	case AF_INET6:
	sin6 = (struct sockaddr_in6 )(void )ifa->ifa_addr;
	net6 = (struct sockaddr_in6 )(void )ifa->ifa_netmask;
	#ifdef __KAME__
	if (IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr))
	/* Remove the scope from the address */
	sin6->sin6_addr.s6_addr[2] =
	sin6->sin6_addr.s6_addr[3] = '\0';
	#endif
	ifa_flags = if_addrflags6(&sin6->sin6_addr, ifp);
	if (ifa_flags != -1)
	ipv6_handleifa(ctx, RTM_NEWADDR, ifs,
	ifa->ifa_name,
	&sin6->sin6_addr,
	ipv6_prefixlen(&net6->sin6_addr),
	ifa_flags);
	break;
	#endif
	}
	}
	}

	struct if_head *
	if_discover(struct dhcpcd_ctx ctx, int argc, char const *argv)
	{
	struct ifaddrs ifaddrs, ifa;
	char *p;
	int i;
	struct if_head *ifs;
	struct interface *ifp;
	const char *lease_identifier;
	char ifn[IF_NAMESIZE];

	#ifdef __linux__
	char alias[IF_NAMESIZE];
	#endif

	#ifdef AF_LINK
	const struct sockaddr_dl *sdl;
	#ifdef SIOCGIFPRIORITY
	struct ifreq ifr;
	int s_inet;
	#endif
	#ifdef IFLR_ACTIVE
	struct if_laddrreq iflr;
	int s_link;
	#endif

	#ifdef SIOCGIFPRIORITY
	if ((s_inet = socket(PF_INET, SOCK_DGRAM, 0)) == -1)
	return NULL;
	#endif
	#ifdef IFLR_ACTIVE
	if ((s_link = socket(PF_LINK, SOCK_DGRAM, 0)) == -1) {
	#ifdef SIOCGIFPRIORITY
	close(s_inet);
	#endif
	return NULL;
	}
	memset(&iflr, 0, sizeof(iflr));
	#endif
	#elif AF_PACKET
	const struct sockaddr_ll *sll;
	#endif

	if (getifaddrs(&ifaddrs) == -1)
	return NULL;
	ifs = malloc(sizeof(*ifs));
	if (ifs == NULL)
	return NULL;
	TAILQ_INIT(ifs);

	for (ifa = ifaddrs; ifa; ifa = ifa->ifa_next) {
	if (ifa->ifa_addr != NULL) {
	#ifdef AF_LINK
	if (ifa->ifa_addr->sa_family != AF_LINK)
	continue;
	#elif AF_PACKET
	if (ifa->ifa_addr->sa_family != AF_PACKET)
	continue;
	#endif
	}

	/* It's possible for an interface to have >1 AF_LINK.
	* For our purposes, we use the first one. */
	TAILQ_FOREACH(ifp, ifs, next) {
	if (strcmp(ifp->name, ifa->ifa_name) == 0)
	break;
	}
	if (ifp)
	continue;

	lease_identifier = NULL;
	if (argc > 0) {
	for (i = 0; i < argc; i++) {
	int intf_len = strlen(argv[i]);
	split_interface_lease(argv[i], &intf_len,
	&lease_identifier);
	if (intf_len > IF_NAMESIZE)
	continue;
	strlcpy(ifn, argv[i], intf_len + 1);
	#ifdef __linux__
	strlcpy(alias, argv[i], intf_len + 1);
	/* Check the real interface name */
	p = strchr(ifn, ':');
	if (p)
	*p = '\0';
	#endif
	if (strcmp(ifn, ifa->ifa_name) == 0)
	break;
	}
	if (i == argc)
	continue;
	} else {
	strlcpy(ifn, ifa->ifa_name, sizeof(ifn));
	#ifdef __linux
	strlcpy(alias, ifa->ifa_name, sizeof(alias));
	#endif
	/* -1 means we're discovering against a specific
	* interface, but we still need the below rules
	* to apply. */
	if (argc == -1 && strcmp(argv[0], ifa->ifa_name) != 0)
	continue;
	}
	p = ifn;

	for (i = 0; i < ctx->ifdc; i++)
	if (!fnmatch(ctx->ifdv[i], p, 0))
	break;
	if (i < ctx->ifdc)
	continue;
	for (i = 0; i < ctx->ifac; i++)
	if (!fnmatch(ctx->ifav[i], p, 0))
	break;
	if (ctx->ifac && i == ctx->ifac)
	continue;

	/* Ensure that the interface name has settled */
	if (!dev_initialized(ctx, p))
	continue;

	/* Don't allow loopback or pointopoint unless explicit */
	if (ifa->ifa_flags & (IFF_LOOPBACK \| IFF_POINTOPOINT)) {
	if ((argc == 0 \|\| argc == -1) &&
	ctx->ifac == 0 && !if_hasconf(ctx, p))
	continue;
	}

	if (if_vimaster(p) == 1) {
	logger(ctx, argc ? LOG_ERR : LOG_DEBUG,
	"%s: is a Virtual Interface Master, skipping", p);
	continue;
	}

	ifp = calloc(1, sizeof(*ifp));
	if (ifp == NULL) {
	logger(ctx, LOG_ERR, "%s: %m", __func__);
	break;
	}
	ifp->ctx = ctx;
	#ifdef __linux__
	strlcpy(ifp->alias, alias, sizeof(ifp->alias));
	#endif
	strlcpy(ifp->name, p, sizeof(ifp->name));
	if (lease_identifier) {
	strlcpy(ifp->lease_identifier, lease_identifier,
	sizeof(ifp->lease_identifier));
	}
	ifp->flags = ifa->ifa_flags;
	ifp->carrier = if_carrier(ifp);

	if (ifa->ifa_addr != NULL) {
	#ifdef AF_LINK
	sdl = (const struct sockaddr_dl )(void )ifa->ifa_addr;

	#ifdef IFLR_ACTIVE
	/* We need to check for active address */
	strlcpy(iflr.iflr_name, ifp->name,
	sizeof(iflr.iflr_name));
	memcpy(&iflr.addr, ifa->ifa_addr,
	MIN(ifa->ifa_addr->sa_len, sizeof(iflr.addr)));
	iflr.flags = IFLR_PREFIX;
	iflr.prefixlen = (unsigned int)sdl->sdl_alen * NBBY;
	if (ioctl(s_link, SIOCGLIFADDR, &iflr) == -1 \|\|
	!(iflr.flags & IFLR_ACTIVE))
	{
	if_free(ifp);
	continue;
	}
	#endif

	ifp->index = sdl->sdl_index;
	switch(sdl->sdl_type) {
	#ifdef IFT_BRIDGE
	case IFT_BRIDGE: /* FALLTHROUGH */
	#endif
	#ifdef IFT_PPP
	case IFT_PPP: /* FALLTHROUGH */
	#endif
	#ifdef IFT_PROPVIRTUAL
	case IFT_PROPVIRTUAL: /* FALLTHROUGH */
	#endif
	#if defined(IFT_BRIDGE) \|\| defined(IFT_PPP) \|\| defined(IFT_PROPVIRTUAL)
	/* Don't allow unless explicit */
	if ((argc == 0 \|\| argc == -1) &&
	ctx->ifac == 0 &&
	!if_hasconf(ctx, ifp->name))
	{
	logger(ifp->ctx, LOG_DEBUG,
	"%s: ignoring due to"
	" interface type and"
	" no config",
	ifp->name);
	if_free(ifp);
	continue;
	}
	/* FALLTHROUGH */
	#endif
	#ifdef IFT_L2VLAN
	case IFT_L2VLAN: /* FALLTHROUGH */
	#endif
	#ifdef IFT_L3IPVLAN
	case IFT_L3IPVLAN: /* FALLTHROUGH */
	#endif
	case IFT_ETHER:
	ifp->family = ARPHRD_ETHER;
	break;
	#ifdef IFT_IEEE1394
	case IFT_IEEE1394:
	ifp->family = ARPHRD_IEEE1394;
	break;
	#endif
	#ifdef IFT_INFINIBAND
	case IFT_INFINIBAND:
	ifp->family = ARPHRD_INFINIBAND;
	break;
	#endif
	default:
	/* Don't allow unless explicit */
	if ((argc == 0 \|\| argc == -1) &&
	ctx->ifac == 0 &&
	!if_hasconf(ctx, ifp->name))
	{
	if_free(ifp);
	continue;
	}
	logger(ifp->ctx, LOG_WARNING,
	"%s: unsupported interface type %.2x",
	ifp->name, sdl->sdl_type);
	/* Pretend it's ethernet */
	ifp->family = ARPHRD_ETHER;
	break;
	}
	ifp->hwlen = sdl->sdl_alen;
	#ifndef CLLADDR
	# define CLLADDR(s) ((const char *)((s)->sdl_data + (s)->sdl_nlen))
	#endif
	memcpy(ifp->hwaddr, CLLADDR(sdl), ifp->hwlen);
	#elif AF_PACKET
	sll = (const struct sockaddr_ll )(void )ifa->ifa_addr;
	ifp->index = (unsigned int)sll->sll_ifindex;
	ifp->family = sll->sll_hatype;
	ifp->hwlen = sll->sll_halen;
	if (ifp->hwlen != 0)
	memcpy(ifp->hwaddr, sll->sll_addr, ifp->hwlen);
	#endif
	}
	#ifdef __linux__
	/* PPP addresses on Linux don't have hardware addresses */
	else
	ifp->index = if_nametoindex(ifp->name);
	#endif

	/* We only work on ethernet by default */
	if (ifp->family != ARPHRD_ETHER) {
	if ((argc == 0 \|\| argc == -1) &&
	ctx->ifac == 0 && !if_hasconf(ctx, ifp->name))
	{
	if_free(ifp);
	continue;
	}
	switch (ifp->family) {
	case ARPHRD_IEEE1394:
	case ARPHRD_INFINIBAND:
	#ifdef ARPHRD_LOOPBACK
	case ARPHRD_LOOPBACK:
	#endif
	#ifdef ARPHRD_PPP
	case ARPHRD_PPP:
	#endif
	/* We don't warn for supported families */
	break;

	/* IFT already checked */
	#ifndef AF_LINK
	default:
	logger(ifp->ctx, LOG_WARNING,
	"%s: unsupported interface family %.2x",
	ifp->name, ifp->family);
	break;
	#endif
	}
	}

	/* Handle any platform init for the interface */
	if (if_init(ifp) == -1) {
	logger(ifp->ctx, LOG_ERR, "%s: if_init: %m", p);
	if_free(ifp);
	continue;
	}

	/* Ensure that the MTU is big enough for DHCP */
	if (if_getmtu(ifp->name) < MTU_MIN &&
	if_setmtu(ifp->name, MTU_MIN) == -1)
	{
	logger(ifp->ctx, LOG_ERR, "%s: set_mtu: %m", p);
	if_free(ifp);
	continue;
	}

	#ifdef SIOCGIFPRIORITY
	/* Respect the interface priority */
	memset(&ifr, 0, sizeof(ifr));
	strlcpy(ifr.ifr_name, ifp->name, sizeof(ifr.ifr_name));
	if (ioctl(s_inet, SIOCGIFPRIORITY, &ifr) == 0)
	ifp->metric = ifr.ifr_metric;
	#else
	/* We reserve the 100 range for virtual interfaces, if and when
	* we can work them out. */
	ifp->metric = 200 + ifp->index;
	if (if_getssid(ifp) != -1) {
	ifp->wireless = 1;
	ifp->metric += 100;
	}
	#endif

	TAILQ_INSERT_TAIL(ifs, ifp, next);
	}

	if (!ifs) {
	logger(ctx, LOG_INFO, "%s: no matching interfaces", __func__);
	for (ifa = ifaddrs; ifa; ifa = ifa->ifa_next) {
	logger(ctx, LOG_INFO, "%s: considered %s",
	__func__, ifa->ifa_name);
	}
	}

	if_learnaddrs1(ctx, ifs, ifaddrs);
	freeifaddrs(ifaddrs);

	#ifdef SIOCGIFPRIORITY
	close(s_inet);
	#endif
	#ifdef IFLR_ACTIVE
	close(s_link);
	#endif

	return ifs;
	}

	static struct interface *
	if_findindexname(struct if_head ifaces, unsigned int idx, const char name)
	{

	if (ifaces != NULL) {
	struct interface *ifp;

	TAILQ_FOREACH(ifp, ifaces, next) {
	if ((ifp->options == NULL \|\|
	!(ifp->options->options & DHCPCD_PFXDLGONLY)) &&
	((name && strcmp(ifp->name, name) == 0) \|\|
	#ifdef __linux__
	(name && strcmp(ifp->alias, name) == 0) \|\|
	#endif
	(!name && ifp->index == idx)))
	return ifp;
	}
	}

	errno = ESRCH;
	return NULL;
	}

	struct interface *
	if_find(struct if_head ifaces, const char name)
	{

	return if_findindexname(ifaces, 0, name);
	}

	struct interface *
	if_findindex(struct if_head *ifaces, unsigned int idx)
	{

	return if_findindexname(ifaces, idx, NULL);
	}

	int
	if_domtu(const char *ifname, short int mtu)
	{
	int s, r;
	struct ifreq ifr;

	if ((s = socket(PF_INET, SOCK_DGRAM, 0)) == -1)
	return -1;
	memset(&ifr, 0, sizeof(ifr));
	strlcpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name));
	ifr.ifr_mtu = mtu;
	r = ioctl(s, mtu ? SIOCSIFMTU : SIOCGIFMTU, &ifr);
	close(s);
	if (r == -1)
	return -1;
	return ifr.ifr_mtu;
	}

	/* Interface comparer for working out ordering. */
	static int
	if_cmp(const struct interface si, const struct interface ti)
	{
	#ifdef INET
	int r;
	#endif

	/* Always prefer master interfaces */
	if (!(si->options->options & DHCPCD_PFXDLGONLY) &&
	ti->options->options & DHCPCD_PFXDLGONLY)
	return -1;
	if (si->options->options & DHCPCD_PFXDLGONLY &&
	!(ti->options->options & DHCPCD_PFXDLGONLY))
	return 1;

	/* Check carrier status first */
	if (si->carrier > ti->carrier)
	return -1;
	if (si->carrier < ti->carrier)
	return 1;

	if (D_STATE_RUNNING(si) && !D_STATE_RUNNING(ti))
	return -1;
	if (!D_STATE_RUNNING(si) && D_STATE_RUNNING(ti))
	return 1;
	if (RS_STATE_RUNNING(si) && !RS_STATE_RUNNING(ti))
	return -1;
	if (!RS_STATE_RUNNING(si) && RS_STATE_RUNNING(ti))
	return 1;
	if (D6_STATE_RUNNING(si) && !D6_STATE_RUNNING(ti))
	return -1;
	if (!D6_STATE_RUNNING(si) && D6_STATE_RUNNING(ti))
	return 1;

	#ifdef INET
	/* Special attention needed here due to states and IPv4LL. */
	if ((r = ipv4_ifcmp(si, ti)) != 0)
	return r;
	#endif

	/* 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
	if_sortinterfaces(struct dhcpcd_ctx *ctx)
	{
	struct if_head sorted;
	struct interface ifp, ift;

	if (ctx->ifaces == NULL \|\|
	(ifp = TAILQ_FIRST(ctx->ifaces)) == NULL \|\|
	TAILQ_NEXT(ifp, next) == NULL)
	return;

	TAILQ_INIT(&sorted);
	TAILQ_REMOVE(ctx->ifaces, ifp, next);
	TAILQ_INSERT_HEAD(&sorted, ifp, next);
	while ((ifp = TAILQ_FIRST(ctx->ifaces))) {
	TAILQ_REMOVE(ctx->ifaces, ifp, next);
	TAILQ_FOREACH(ift, &sorted, next) {
	if (if_cmp(ifp, ift) == -1) {
	TAILQ_INSERT_BEFORE(ift, ifp, next);
	break;
	}
	}
	if (ift == NULL)
	TAILQ_INSERT_TAIL(&sorted, ifp, next);
	}
	TAILQ_CONCAT(ctx->ifaces, &sorted, next);
	}