ipv4.c

/*
 * dhcpcd - DHCP client daemon
 * Copyright (c) 2006-2016 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/socket.h>
#include <sys/types.h>

#include <arpa/inet.h>
#include <net/if.h>
#include <net/route.h>
#include <netinet/if_ether.h>
#include <netinet/in.h>

#include <assert.h>
#include <ctype.h>
#include <errno.h>
#include <stdbool.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include "config.h"
#include "arp.h"
#include "common.h"
#include "dhcpcd.h"
#include "dhcp.h"
#include "if.h"
#include "if-options.h"
#include "ipv4.h"
#include "ipv4ll.h"
#include "route.h"
#include "script.h"
#include "sa.h"

#define IPV4_LOOPBACK_ROUTE
#if defined(__linux__) || defined(__sun) || (defined(BSD) && defined(RTF_LOCAL))
/* Linux has had loopback routes in the local table since 2.2
 * Solaris does not seem to support loopback routes. */
#undef IPV4_LOOPBACK_ROUTE
#endif

uint8_t
inet_ntocidr(struct in_addr address)
{
	uint8_t cidr = 0;
	uint32_t mask = htonl(address.s_addr);

	while (mask) {
		cidr++;
		mask <<= 1;
	}
	return cidr;
}

int
inet_cidrtoaddr(int cidr, struct in_addr *addr)
{
	int ocets;

	if (cidr < 1 || cidr > 32) {
		errno = EINVAL;
		return -1;
	}
	ocets = (cidr + 7) / NBBY;

	addr->s_addr = 0;
	if (ocets > 0) {
		memset(&addr->s_addr, 255, (size_t)ocets - 1);
		memset((unsigned char *)&addr->s_addr + (ocets - 1),
		    (256 - (1 << (32 - cidr) % NBBY)), 1);
	}

	return 0;
}

uint32_t
ipv4_getnetmask(uint32_t addr)
{
	uint32_t dst;

	if (addr == 0)
		return 0;

	dst = htonl(addr);
	if (IN_CLASSA(dst))
		return ntohl(IN_CLASSA_NET);
	if (IN_CLASSB(dst))
		return ntohl(IN_CLASSB_NET);
	if (IN_CLASSC(dst))
		return ntohl(IN_CLASSC_NET);

	return 0;
}

struct ipv4_addr *
ipv4_iffindaddr(struct interface *ifp,
    const struct in_addr *addr, const struct in_addr *mask)
{
	struct ipv4_state *state;
	struct ipv4_addr *ap;

	state = IPV4_STATE(ifp);
	if (state) {
		TAILQ_FOREACH(ap, &state->addrs, next) {
			if ((addr == NULL || ap->addr.s_addr == addr->s_addr) &&
			    (mask == NULL || ap->mask.s_addr == mask->s_addr))
				return ap;
		}
	}
	return NULL;
}

struct ipv4_addr *
ipv4_iffindlladdr(struct interface *ifp)
{
	struct ipv4_state *state;
	struct ipv4_addr *ap;

	state = IPV4_STATE(ifp);
	if (state) {
		TAILQ_FOREACH(ap, &state->addrs, next) {
			if (IN_LINKLOCAL(htonl(ap->addr.s_addr)))
				return ap;
		}
	}
	return NULL;
}

static struct ipv4_addr *
ipv4_iffindmaskaddr(struct interface *ifp, const struct in_addr *addr)
{
	struct ipv4_state *state;
	struct ipv4_addr *ap;

	state = IPV4_STATE(ifp);
	if (state) {
		TAILQ_FOREACH (ap, &state->addrs, next) {
			if ((ap->addr.s_addr & ap->mask.s_addr) ==
			    (addr->s_addr & ap->mask.s_addr))
				return ap;
		}
	}
	return NULL;
}

struct ipv4_addr *
ipv4_findaddr(struct dhcpcd_ctx *ctx, const struct in_addr *addr)
{
	struct interface *ifp;
	struct ipv4_addr *ap;

	TAILQ_FOREACH(ifp, ctx->ifaces, next) {
		ap = ipv4_iffindaddr(ifp, addr, NULL);
		if (ap)
			return ap;
	}
	return NULL;
}

struct ipv4_addr *
ipv4_findmaskaddr(struct dhcpcd_ctx *ctx, const struct in_addr *addr)
{
	struct interface *ifp;
	struct ipv4_addr *ap;

	TAILQ_FOREACH(ifp, ctx->ifaces, next) {
		ap = ipv4_iffindmaskaddr(ifp, addr);
		if (ap)
			return ap;
	}
	return NULL;
}

int
ipv4_hasaddr(const struct interface *ifp)
{
	const struct dhcp_state *dstate;

	if (IPV4LL_STATE_RUNNING(ifp))
		return 1;

	dstate = D_CSTATE(ifp);
	return (dstate &&
	    dstate->added == STATE_ADDED &&
	    dstate->addr != NULL);
}

/* Interface comparer for working out ordering. */
int
ipv4_ifcmp(const struct interface *si, const struct interface *ti)
{
	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;
	/* Always prefer proper leases */
	if (!(sis->added & STATE_FAKE) && (sis->added & STATE_FAKE))
		return -1;
	if ((sis->added & STATE_FAKE) && !(sis->added & STATE_FAKE))
		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) {
		if (IS_DHCP(sis->new) && !IS_DHCP(tis->new))
			return -1;
		if (!IS_DHCP(sis->new) && IS_DHCP(tis->new))
			return 1;
	}
	return 0;
}

static int
inet_dhcproutes(struct rt_head *routes, struct interface *ifp)
{
	const struct dhcp_state *state;
	struct rt_head nroutes;
	struct rt *rt, *r = NULL;
	struct in_addr in;
	uint16_t mtu;
	int n;

	state = D_CSTATE(ifp);
	if (state == NULL || state->state != DHS_BOUND)
		return 0;

	TAILQ_INIT(&nroutes);

	/* First, add a subnet route. */
	if (!(ifp->flags & IFF_POINTOPOINT) &&
#ifndef BSD
		/* BSD adds a route in this instance */
	    state->addr->mask.s_addr != INADDR_BROADCAST &&
#endif
	    state->addr->mask.s_addr != INADDR_ANY)
	{
		if ((rt = rt_new(ifp)) == NULL)
			return -1;
		rt->rt_dflags |= RTDF_IFA_ROUTE;
		in.s_addr = state->addr->addr.s_addr & state->addr->mask.s_addr;
		sa_in_init(&rt->rt_dest, &in);
		in.s_addr = state->addr->mask.s_addr;
		sa_in_init(&rt->rt_netmask, &in);
		//in.s_addr = INADDR_ANY;
		//sa_in_init(&rt->rt_gateway, &in);
		rt->rt_gateway.sa_family = AF_UNSPEC;
		TAILQ_INSERT_HEAD(&nroutes, rt, rt_next);
	}

	/* If any set routes, grab them, otherwise DHCP routes. */
	if (TAILQ_FIRST(&ifp->options->routes)) {
		TAILQ_FOREACH(r, &ifp->options->routes, rt_next) {
			if (sa_is_unspecified(&r->rt_gateway))
				break;
			if ((rt = rt_new(ifp)) == NULL)
				return -1;
			memcpy(rt, r, sizeof(*rt));
			TAILQ_INSERT_TAIL(&nroutes, rt, rt_next);
		}
	} else {
		if (dhcp_get_routes(&nroutes, ifp) == -1)
			return -1;
	}

	/* If configured, Install a gateway to the desintion
	 * for P2P interfaces. */
	if (ifp->flags & IFF_POINTOPOINT &&
	    ifp->options->options & DHCPCD_GATEWAY &&
	    has_option_mask(ifp->options->dstmask, DHO_ROUTER))
	{
		if ((rt = rt_new(ifp)) == NULL)
			return -1;
		in.s_addr = INADDR_ANY;
		sa_in_init(&rt->rt_dest, &in);
		sa_in_init(&rt->rt_netmask, &in);
		sa_in_init(&rt->rt_gateway, &state->addr->brd);
		sa_in_init(&rt->rt_ifa, &state->addr->addr);
		TAILQ_INSERT_HEAD(routes, rt, rt_next);
	}

	/* Copy our address as the source address and set mtu */
	mtu = dhcp_get_mtu(ifp);
	n = 0;
	TAILQ_FOREACH(rt, &nroutes, rt_next) {
		rt->rt_mtu = mtu;
		sa_in_init(&rt->rt_ifa, &state->addr->addr);
		n++;
	}
	TAILQ_CONCAT(routes, &nroutes, rt_next);

	return n;
}

/* We should check to ensure the routers are on the same subnet
 * OR supply a host route. If not, warn and add a host route. */
static int
inet_routerhostroute(struct rt_head *routes, struct interface *ifp)
{
	struct rt *rt, *rth;
	struct sockaddr_in *dest, *netmask, *gateway;
	const char *cp, *cp2, *cp3, *cplim;
	struct if_options *ifo;
	const struct dhcp_state *state;
	struct in_addr in;
	int n;

	/* Don't add a host route for these interfaces. */
	if (ifp->flags & (IFF_LOOPBACK | IFF_POINTOPOINT))
		return 0;

	n = 0;
	TAILQ_FOREACH(rt, routes, rt_next) {
		if (rt->rt_dest.sa_family != AF_INET)
			continue;
		if (!sa_is_unspecified(&rt->rt_dest) ||
		    sa_is_unspecified(&rt->rt_gateway))
			continue;
		gateway = satosin(&rt->rt_gateway);
		/* Scan for a route to match */
		TAILQ_FOREACH(rth, routes, rt_next) {
			if (rth == rt)
				break;
			/* match host */
			if (sa_cmp(&rth->rt_dest, &rt->rt_gateway) == 0)
				break;
			/* match subnet */
			cp = (const char *)&gateway->sin_addr.s_addr;
			dest = satosin(&rth->rt_dest);
			cp2 = (const char *)&dest->sin_addr.s_addr;
			netmask = satosin(&rth->rt_netmask);
			cp3 = (const char *)&netmask->sin_addr.s_addr;
			cplim = cp3 + sizeof(netmask->sin_addr.s_addr);
			while (cp3 < cplim) {
				if ((*cp++ ^ *cp2++) & *cp3++)
					break;
			}
			if (cp3 == cplim)
				break;
		}
		if (rth != rt)
			continue;
		if ((state = D_CSTATE(ifp)) == NULL)
			continue;
		ifo = ifp->options;
		if (ifp->flags & IFF_NOARP) {
			if (!(ifo->options & DHCPCD_ROUTER_HOST_ROUTE_WARNED) &&
			    !(state->added & STATE_FAKE))
			{
				char buf[INET_MAX_ADDRSTRLEN];

				ifo->options |= DHCPCD_ROUTER_HOST_ROUTE_WARNED;
				logger(ifp->ctx, LOG_WARNING,
				    "%s: forcing router %s through interface",
				    ifp->name,
				    sa_addrtop(&rt->rt_gateway,
				    buf, sizeof(buf)));
			}
			gateway->sin_addr.s_addr = INADDR_ANY;
			continue;
		}
		if (!(ifo->options & DHCPCD_ROUTER_HOST_ROUTE_WARNED) &&
		    !(state->added & STATE_FAKE))
		{
			char buf[INET_MAX_ADDRSTRLEN];

			ifo->options |= DHCPCD_ROUTER_HOST_ROUTE_WARNED;
			logger(ifp->ctx, LOG_WARNING,
			    "%s: router %s requires a host route",
			    ifp->name,
			    sa_addrtop(&rt->rt_gateway, buf, sizeof(buf)));
		}
		if ((rth = rt_new(ifp)) == NULL)
			return -1;
		sa_in_init(&rth->rt_dest, &gateway->sin_addr);
		in.s_addr = INADDR_BROADCAST;
		sa_in_init(&rth->rt_netmask, &in);
		in.s_addr = INADDR_ANY;
		sa_in_init(&rth->rt_gateway, &in);
		rth->rt_mtu = dhcp_get_mtu(ifp);
		sa_in_init(&rth->rt_ifa, &state->addr->addr);
		TAILQ_INSERT_BEFORE(rt, rth, rt_next);
		n++;
	}
	return n;
}

bool
inet_getroutes(struct dhcpcd_ctx *ctx, struct rt_head *routes)
{
	struct interface *ifp;
	struct rt def;
	bool have_default;

	TAILQ_FOREACH(ifp, ctx->ifaces, next) {
		if (!ifp->active)
			continue;
		if (inet_dhcproutes(routes, ifp) == -1)
			return false;
		if (ipv4ll_subnetroute(routes, ifp) == -1)
			return false;
		if (ifp->options->options & DHCPCD_GATEWAY) {
			if (inet_routerhostroute(routes, ifp) == -1)
				return false;
		}
	}

	/* If there is no default route, see if we can use an IPv4LL one. */
	memset(&def, 0, sizeof(def));
	def.rt_dest.sa_family = AF_INET;
	have_default = (rt_find(routes, &def) != NULL);
	if (!have_default) {
		TAILQ_FOREACH(ifp, ctx->ifaces, next) {
			if (ifp->active &&
			    ifp->options->options & DHCPCD_GATEWAY &&
			    ipv4ll_defaultroute(routes, ifp) == 1)
				break;
		}
	}

	return true;
}

int
ipv4_deladdr(struct ipv4_addr *addr, int keeparp)
{
	int r;
	struct ipv4_state *state;
	struct ipv4_addr *ap;
#ifdef ARP
	struct arp_state *astate;
#else
	UNUSED(keeparp);
#endif

	logger(addr->iface->ctx, LOG_DEBUG,
	    "%s: deleting IP address %s", addr->iface->name, addr->saddr);

	r = if_address(RTM_DELADDR, addr);
	if (r == -1 &&
	    errno != EADDRNOTAVAIL && errno != ESRCH &&
	    errno != ENXIO && errno != ENODEV)
		logger(addr->iface->ctx, LOG_ERR, "%s: %s: %m",
		    addr->iface->name, __func__);

#ifdef ARP
	if (!keeparp && (astate = arp_find(addr->iface, &addr->addr)) != NULL)
		arp_free(astate);
#endif

	state = IPV4_STATE(addr->iface);
	TAILQ_FOREACH(ap, &state->addrs, next) {
		if (IPV4_MASK_EQ(ap, addr)) {
			struct dhcp_state *dstate;

			dstate = D_STATE(ap->iface);
			TAILQ_REMOVE(&state->addrs, ap, next);
			free(ap);

			if (dstate && dstate->addr == ap) {
				dstate->added = 0;
				dstate->addr = NULL;
			}
			break;
		}
	}

	return r;
}

static int
delete_address(struct interface *ifp)
{
	int r;
	struct if_options *ifo;
	struct dhcp_state *state;

	state = D_STATE(ifp);
	ifo = ifp->options;
	/* The lease could have been added, but the address deleted
	 * by a 3rd party. */
	if (state->addr == NULL ||
	    ifo->options & DHCPCD_INFORM ||
	    (ifo->options & DHCPCD_STATIC && ifo->req_addr.s_addr == 0))
		return 0;
	r = ipv4_deladdr(state->addr, 0);
	return r;
}

struct ipv4_state *
ipv4_getstate(struct interface *ifp)
{
	struct ipv4_state *state;

	state = IPV4_STATE(ifp);
	if (state == NULL) {
	        ifp->if_data[IF_DATA_IPV4] = malloc(sizeof(*state));
		state = IPV4_STATE(ifp);
		if (state == NULL) {
			logger(ifp->ctx, LOG_ERR, "%s: %m", __func__);
			return NULL;
		}
		TAILQ_INIT(&state->addrs);
#ifdef BSD
		state->buffer_size = state->buffer_len = state->buffer_pos = 0;
		state->buffer = NULL;
#endif
	}
	return state;
}

#ifdef ALIAS_ADDR
/* Find the next logical aliase address we can use. */
static int
ipv4_aliasaddr(struct ipv4_addr *ia, struct ipv4_addr **repl)
{
	struct ipv4_state *state;
	struct ipv4_addr *iap;
	unsigned int lun;
	char alias[IF_NAMESIZE];

	if (ia->alias[0] != '\0')
		return 0;

	lun = 0;
	state = IPV4_STATE(ia->iface);
find_lun:
	if (lun == 0)
		strlcpy(alias, ia->iface->name, sizeof(alias));
	else
		snprintf(alias, sizeof(alias), "%s:%u", ia->iface->name, lun);
	TAILQ_FOREACH(iap, &state->addrs, next) {
		if (iap->alias[0] != '\0' && iap->addr.s_addr == INADDR_ANY) {
			/* No address assigned? Lets use it. */
			strlcpy(ia->alias, iap->alias, sizeof(ia->alias));
			if (repl)
				*repl = iap;
			return 1;
		}
		if (strcmp(iap->alias, alias) == 0)
			break;
	}

	if (iap != NULL) {
		if (lun == UINT_MAX) {
			errno = ERANGE;
			return -1;
		}
		lun++;
		goto find_lun;
	}

	strlcpy(ia->alias, alias, sizeof(ia->alias));
	return 0;
}
#endif

struct ipv4_addr *
ipv4_addaddr(struct interface *ifp, const struct in_addr *addr,
    const struct in_addr *mask, const struct in_addr *bcast)
{
	struct ipv4_state *state;
	struct ipv4_addr *ia;
#ifdef ALIAS_ADDR
	int replaced, blank;
	struct ipv4_addr *replaced_ia;
#endif

	if ((state = ipv4_getstate(ifp)) == NULL) {
		logger(ifp->ctx, LOG_ERR, "%s: ipv4_getstate: %m", __func__);
		return NULL;
	}
	if (ifp->options->options & DHCPCD_NOALIAS) {
		struct ipv4_addr *ian;

		TAILQ_FOREACH_SAFE(ia, &state->addrs, next, ian) {
			if (ia->addr.s_addr != addr->s_addr)
				ipv4_deladdr(ia, 0);
		}
	}

	if ((ia = malloc(sizeof(*ia))) == NULL) {
		logger(ifp->ctx, LOG_ERR, "%s: %m", __func__);
		return NULL;
	}

	ia->iface = ifp;
	ia->addr = *addr;
	ia->mask = *mask;
	ia->brd = *bcast;
#ifdef IN_IFF_TENTATIVE
	ia->addr_flags = IN_IFF_TENTATIVE;
#endif
	snprintf(ia->saddr, sizeof(ia->saddr), "%s/%d",
	    inet_ntoa(*addr), inet_ntocidr(*mask));

#ifdef ALIAS_ADDR
	blank = (ia->alias[0] == '\0');
	if ((replaced = ipv4_aliasaddr(ia, &replaced_ia)) == -1) {
		logger(ifp->ctx, LOG_ERR, "%s: ipv4_aliasaddr: %m", ifp->name);
		free(ia);
		return NULL;
	}
	if (blank)
		logger(ia->iface->ctx, LOG_DEBUG, "%s: aliased %s",
		    ia->alias, ia->saddr);
#endif

	logger(ifp->ctx, LOG_DEBUG, "%s: adding IP address %s broadcast %s",
	    ifp->name, ia->saddr, inet_ntoa(*bcast));
	if (if_address(RTM_NEWADDR, ia) == -1) {
		if (errno != EEXIST)
			logger(ifp->ctx, LOG_ERR, "%s: if_addaddress: %m",
			    __func__);
		free(ia);
		return NULL;
	}

#ifdef ALIAS_ADDR
	if (replaced) {
		TAILQ_REMOVE(&state->addrs, replaced_ia, next);
		free(replaced_ia);
	}
#endif

	TAILQ_INSERT_TAIL(&state->addrs, ia, next);
	return ia;
}

static int
ipv4_daddaddr(struct interface *ifp, const struct dhcp_lease *lease)
{
	struct dhcp_state *state;
	struct ipv4_addr *ia;

	ia = ipv4_addaddr(ifp, &lease->addr, &lease->mask, &lease->brd);
	if (ia == NULL)
		return -1;

	state = D_STATE(ifp);
	state->added = STATE_ADDED;
	state->addr = ia;
	return 0;
}

int
ipv4_preferanother(struct interface *ifp)
{
	struct dhcp_state *state = D_STATE(ifp), *nstate;
	struct interface *ifn;
	int preferred;

	if (state == NULL)
		return 0;

	preferred = 0;
	if (!state->added)
		goto out;

	TAILQ_FOREACH(ifn, ifp->ctx->ifaces, next) {
		if (ifn == ifp)
			break; /* We are already the most preferred */
		nstate = D_STATE(ifn);
		if (nstate && !nstate->added &&
		    state->addr != NULL &&
		    nstate->lease.addr.s_addr == state->addr->addr.s_addr)
		{
			preferred = 1;
			delete_address(ifp);
			if (ifn->options->options & DHCPCD_ARP)
				dhcp_bind(ifn);
			else {
				ipv4_daddaddr(ifn, &nstate->lease);
				nstate->added = STATE_ADDED;
			}
			break;
		}
	}

out:
	rt_build(ifp->ctx, AF_INET);
	return preferred;
}

void
ipv4_applyaddr(void *arg)
{
	struct interface *ifp = arg, *ifn;
	struct dhcp_state *state = D_STATE(ifp), *nstate;
	struct dhcp_lease *lease;
	struct if_options *ifo = ifp->options;
	struct ipv4_addr *ia;
	int r;

	if (state == NULL)
		return;

	lease = &state->lease;
	if_sortinterfaces(ifp->ctx);

	if (state->new == NULL) {
		if ((ifo->options & (DHCPCD_EXITING | DHCPCD_PERSISTENT)) !=
		    (DHCPCD_EXITING | DHCPCD_PERSISTENT))
		{
			if (state->added && !ipv4_preferanother(ifp)) {
				delete_address(ifp);
				rt_build(ifp->ctx, AF_INET);
			}
			script_runreason(ifp, state->reason);
		} else
			rt_build(ifp->ctx, AF_INET);
		return;
	}

	/* Ensure only one interface has the address */
	r = 0;
	TAILQ_FOREACH(ifn, ifp->ctx->ifaces, next) {
		if (ifn == ifp) {
			r = 1; /* past ourselves */
			continue;
		}
		nstate = D_STATE(ifn);
		if (nstate && nstate->added &&
		    nstate->addr &&
		    nstate->addr->addr.s_addr == lease->addr.s_addr)
		{
			if (r == 0) {
				logger(ifp->ctx, LOG_INFO,
				    "%s: preferring %s on %s",
				    ifp->name,
				    inet_ntoa(lease->addr),
				    ifn->name);
				return;
			}
			logger(ifp->ctx, LOG_INFO, "%s: preferring %s on %s",
			    ifn->name,
			    inet_ntoa(lease->addr),
			    ifp->name);
			ipv4_deladdr(nstate->addr, 0);
			break;
		}
	}

	/* Does another interface already have the address from a prior boot? */
	if (ifn == NULL) {
		TAILQ_FOREACH(ifn, ifp->ctx->ifaces, next) {
			if (ifn == ifp)
				continue;
			ia = ipv4_iffindaddr(ifn, &lease->addr, NULL);
			if (ia != NULL)
				ipv4_deladdr(ia, 0);
		}
	}

	/* If the netmask or broadcast is different, re-add the addresss */
	ia = ipv4_iffindaddr(ifp, &lease->addr, NULL);
	if (ia &&
	    ia->mask.s_addr == lease->mask.s_addr &&
	    ia->brd.s_addr == lease->brd.s_addr)
		logger(ifp->ctx, LOG_DEBUG,
		    "%s: IP address %s already exists",
		    ifp->name, ia->saddr);
	else {
#if __linux__
		/* Linux does not change netmask/broadcast address
		 * for re-added addresses, so we need to delete the old one
		 * first. */
		if (ia != NULL)
			ipv4_deladdr(ia, 0);
#endif
		r = ipv4_daddaddr(ifp, lease);
		if (r == -1 && errno != EEXIST)
			return;
	}

	ia = ipv4_iffindaddr(ifp, &lease->addr, NULL);
	if (ia == NULL) {
		logger(ifp->ctx, LOG_ERR, "%s: added address vanished",
		    ifp->name);
		return;
	}
#if defined(ARP) && defined(IN_IFF_NOTUSEABLE)
	if (ia->addr_flags & IN_IFF_NOTUSEABLE)
		return;
#endif

	/* Delete the old address if different */
	if (state->addr &&
	    state->addr->addr.s_addr != lease->addr.s_addr &&
	    ipv4_iffindaddr(ifp, &lease->addr, NULL))
		delete_address(ifp);

	state->addr = ia;
	state->added = STATE_ADDED;

	/* Find any freshly added routes, such as the subnet route.
	 * We do this because we cannot rely on recieving the kernel
	 * notification right now via our link socket. */
	if_initrt(ifp->ctx, AF_INET);
	rt_build(ifp->ctx, AF_INET);

#ifdef ARP
	/* Announce the address */
	if (ifo->options & DHCPCD_ARP) {
		struct arp_state *astate;

		if ((astate = arp_find(ifp, &state->addr->addr)) != NULL)
			arp_announce(astate);
	}
#endif

	if (state->state == DHS_BOUND) {
		script_runreason(ifp, state->reason);
		dhcpcd_daemonise(ifp->ctx);
	}
}

void
ipv4_handleifa(struct dhcpcd_ctx *ctx,
    int cmd, struct if_head *ifs, const char *ifname,
    const struct in_addr *addr, const struct in_addr *mask,
    const struct in_addr *brd, const int addrflags)
{
	struct interface *ifp;
	struct ipv4_state *state;
	struct ipv4_addr *ia;
	bool ia_is_new;

	if (ifs == NULL)
		ifs = ctx->ifaces;
	if (ifs == NULL) {
		errno = ESRCH;
		return;
	}
	if ((ifp = if_find(ifs, ifname)) == NULL)
		return;
	if ((state = ipv4_getstate(ifp)) == NULL) {
		errno = ENOENT;
		return;
	}

	ia = ipv4_iffindaddr(ifp, addr, NULL);
	switch (cmd) {
	case RTM_NEWADDR:
		if (ia == NULL) {
			if ((ia = malloc(sizeof(*ia))) == NULL) {
				logger(ifp->ctx, LOG_ERR, "%s: %m", __func__);
				return;
			}
			ia->iface = ifp;
			ia->addr = *addr;
			ia->mask = *mask;
			ia_is_new = true;
#ifdef ALIAS_ADDR
			strlcpy(ia->alias, ifname, sizeof(ia->alias));
#endif
			TAILQ_INSERT_TAIL(&state->addrs, ia, next);
		} else
			ia_is_new = false;
		/* Mask could have changed */
		if (ia_is_new ||
		    (mask->s_addr != INADDR_ANY &&
		    mask->s_addr != ia->mask.s_addr))
		{
			ia->mask = *mask;
			snprintf(ia->saddr, sizeof(ia->saddr), "%s/%d",
			    inet_ntoa(*addr), inet_ntocidr(*mask));
		}
		if (brd != NULL)
			ia->brd = *brd;
		else
			ia->brd.s_addr = INADDR_ANY;
		ia->addr_flags = addrflags;
		break;
	case RTM_DELADDR:
		if (ia == NULL)
			return;
		TAILQ_REMOVE(&state->addrs, ia, next);
		break;
	default:
		return;
	}

	if (addr->s_addr != INADDR_ANY && addr->s_addr != INADDR_BROADCAST) {
#ifdef ARP
		arp_handleifa(cmd, ia);
#endif
		dhcp_handleifa(cmd, ia);
	}

	if (cmd == RTM_DELADDR)
		free(ia);
}

void
ipv4_free(struct interface *ifp)
{
	struct ipv4_state *state;
	struct ipv4_addr *ia;

	if (ifp) {
		state = IPV4_STATE(ifp);
		if (state) {
		        while ((ia = TAILQ_FIRST(&state->addrs))) {
				TAILQ_REMOVE(&state->addrs, ia, next);
				free(ia);
			}
#ifdef BSD
			free(state->buffer);
#endif
			free(state);
		}
	}
}