/*
* 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/queue.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <net/route.h>
#ifdef __linux__
# include <asm/types.h> /* for systems with broken headers */
# include <linux/rtnetlink.h>
#endif
#include <ctype.h>
#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include <syslog.h>
#include <unistd.h>
#include "config.h"
#include "common.h"
#include "dhcpcd.h"
#include "dhcp.h"
#include "if-options.h"
#include "if-pref.h"
#include "ipv4.h"
#include "net.h"
#include "script.h"
#define IPV4_LOOPBACK_ROUTE
#ifdef __linux__
/* Linux has had loopback routes in the local table since 2.2 */
#undef IPV4_LOOPBACK_ROUTE
#endif
static struct rt_head *routes;
int
inet_ntocidr(struct in_addr address)
{
int 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) / 8;
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) % 8)), 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_findaddr(struct interface *ifp,
const struct in_addr *addr, const struct in_addr *net)
{
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) &&
(net == NULL || ap->net.s_addr == net->s_addr))
return ap;
}
}
return NULL;
}
int
ipv4_addrexists(const struct in_addr *addr)
{
struct interface *ifp;
struct dhcp_state *state;
TAILQ_FOREACH(ifp, ifaces, next) {
state = D_STATE(ifp);
if (state) {
if (addr == NULL) {
if (state->addr.s_addr != INADDR_ANY)
return 1;
} else if (addr->s_addr == state->addr.s_addr)
return 1;
}
if (addr != NULL && ipv4_findaddr(ifp, addr, NULL))
return 1;
}
return 0;
}
void
ipv4_freeroutes(struct rt_head *rts)
{
struct rt *r;
if (rts) {
while ((r = TAILQ_FIRST(rts))) {
TAILQ_REMOVE(rts, r, next);
free(r);
}
free(rts);
}
}
#ifdef DEBUG_MEMORY
static void
ipv4_cleanup()
{
ipv4_freeroutes(routes);
}
#endif
int
ipv4_init(void)
{
if (routes == NULL) {
routes = malloc(sizeof(*routes));
if (routes == NULL)
return -1;
TAILQ_INIT(routes);
#ifdef DEBUG_MEMORY
atexit(ipv4_cleanup);
#endif
}
return 0;
}
static struct rt *
find_route(struct rt_head *rts, const struct rt *r, const struct rt *srt)
{
struct rt *rt;
if (rts == NULL)
return NULL;
TAILQ_FOREACH(rt, rts, next) {
if (rt->dest.s_addr == r->dest.s_addr &&
#if HAVE_ROUTE_METRIC
(srt || (!rt->iface ||
rt->iface->metric == r->iface->metric)) &&
#endif
(!srt || srt != rt) &&
rt->net.s_addr == r->net.s_addr)
return rt;
}
return NULL;
}
static void
desc_route(const char *cmd, const struct rt *rt)
{
char addr[sizeof("000.000.000.000") + 1];
const char *ifname = rt->iface->name;
strlcpy(addr, inet_ntoa(rt->dest), sizeof(addr));
if (rt->gate.s_addr == INADDR_ANY)
syslog(LOG_INFO, "%s: %s route to %s/%d", ifname, cmd,
addr, inet_ntocidr(rt->net));
else if (rt->gate.s_addr == rt->dest.s_addr &&
rt->net.s_addr == INADDR_BROADCAST)
syslog(LOG_INFO, "%s: %s host route to %s", ifname, cmd,
addr);
else if (rt->gate.s_addr == htonl(INADDR_LOOPBACK) &&
rt->net.s_addr == INADDR_BROADCAST)
syslog(LOG_INFO, "%s: %s host route to %s via %s", ifname, cmd,
addr, inet_ntoa(rt->gate));
else if (rt->dest.s_addr == INADDR_ANY && rt->net.s_addr == INADDR_ANY)
syslog(LOG_INFO, "%s: %s default route via %s", ifname, cmd,
inet_ntoa(rt->gate));
else
syslog(LOG_INFO, "%s: %s route to %s/%d via %s", ifname, cmd,
addr, inet_ntocidr(rt->net), inet_ntoa(rt->gate));
}
/* If something other than dhcpcd removes a route,
* we need to remove it from our internal table. */
int
ipv4_routedeleted(const struct rt *rt)
{
struct rt *f;
f = find_route(routes, rt, NULL);
if (f == NULL)
return 0;
desc_route("removing", f);
TAILQ_REMOVE(routes, f, next);
free(f);
return 1;
}
#define n_route(a) nc_route(1, a, a)
#define c_route(a, b) nc_route(0, a, b)
static int
nc_route(int add, struct rt *ort, struct rt *nrt)
{
/* Don't set default routes if not asked to */
if (nrt->dest.s_addr == 0 &&
nrt->net.s_addr == 0 &&
!(nrt->iface->options->options & DHCPCD_GATEWAY))
return -1;
desc_route(add ? "adding" : "changing", nrt);
/* We delete and add the route so that we can change metric and
* prefer the interface.
* This also has the nice side effect of flushing ARP entries so
* we don't have to do that manually. */
ipv4_deleteroute(ort);
if (!ipv4_addroute(nrt))
return 0;
syslog(LOG_ERR, "%s: ipv4_addroute: %m", nrt->iface->name);
return -1;
}
static int
d_route(struct rt *rt)
{
int retval;
desc_route("deleting", rt);
retval = ipv4_deleteroute(rt);
if (retval != 0 && errno != ENOENT && errno != ESRCH)
syslog(LOG_ERR,"%s: ipv4_deleteroute: %m", rt->iface->name);
return retval;
}
static struct rt *
get_subnet_route(struct dhcp_message *dhcp)
{
in_addr_t addr;
struct in_addr net;
struct rt *rt;
addr = dhcp->yiaddr;
if (addr == 0)
addr = dhcp->ciaddr;
/* Ensure we have all the needed values */
if (get_option_addr(&net, dhcp, DHO_SUBNETMASK) == -1)
net.s_addr = ipv4_getnetmask(addr);
if (net.s_addr == INADDR_BROADCAST || net.s_addr == INADDR_ANY)
return NULL;
rt = malloc(sizeof(*rt));
rt->dest.s_addr = addr & net.s_addr;
rt->net.s_addr = net.s_addr;
rt->gate.s_addr = 0;
return rt;
}
static struct rt_head *
add_subnet_route(struct rt_head *rt, const struct interface *ifp)
{
struct rt *r;
const struct dhcp_state *s;
if (rt == NULL) /* earlier malloc failed */
return NULL;
s = D_CSTATE(ifp);
if (s->net.s_addr == INADDR_BROADCAST ||
s->net.s_addr == INADDR_ANY)
return rt;
r = malloc(sizeof(*r));
if (r == NULL) {
syslog(LOG_ERR, "%s: %m", __func__);
ipv4_freeroutes(rt);
return NULL;
}
r->dest.s_addr = s->addr.s_addr & s->net.s_addr;
r->net.s_addr = s->net.s_addr;
r->gate.s_addr = 0;
TAILQ_INSERT_HEAD(rt, r, next);
return rt;
}
#ifdef IPV4_LOOPBACK_ROUTE
static struct rt_head *
add_loopback_route(struct rt_head *rt, const struct interface *ifp)
{
struct rt *r;
const struct dhcp_state *s;
if (rt == NULL) /* earlier malloc failed */
return NULL;
s = D_CSTATE(ifp);
if (s->addr.s_addr == INADDR_ANY)
return rt;
r = malloc(sizeof(*r));
if (r == NULL) {
syslog(LOG_ERR, "%s: %m", __func__);
ipv4_freeroutes(rt);
return NULL;
}
r->dest.s_addr = s->addr.s_addr;
r->net.s_addr = INADDR_BROADCAST;
r->gate.s_addr = htonl(INADDR_LOOPBACK);
TAILQ_INSERT_HEAD(rt, r, next);
return rt;
}
#endif
static struct rt_head *
get_routes(struct interface *ifp)
{
struct rt_head *nrt;
struct rt *rt, *r = NULL;
if (ifp->options->routes && TAILQ_FIRST(ifp->options->routes)) {
nrt = malloc(sizeof(*nrt));
TAILQ_INIT(nrt);
TAILQ_FOREACH(rt, ifp->options->routes, next) {
if (rt->gate.s_addr == 0)
break;
r = malloc(sizeof(*r));
if (r == NULL) {
syslog(LOG_ERR, "%s: %m", __func__);
ipv4_freeroutes(nrt);
return NULL;
}
memcpy(r, rt, sizeof(*r));
TAILQ_INSERT_TAIL(nrt, r, next);
}
return nrt;
}
return get_option_routes(ifp, D_STATE(ifp)->new);
}
/* Some DHCP servers add set host routes by setting the gateway
* to the assinged IP address. This differs from our notion of a host route
* where the gateway is the destination address, so we fix it. */
static struct rt_head *
massage_host_routes(struct rt_head *rt, const struct interface *ifp)
{
struct rt *r;
if (rt) {
TAILQ_FOREACH(r, rt, next) {
if (r->gate.s_addr == D_CSTATE(ifp)->addr.s_addr &&
r->net.s_addr == INADDR_BROADCAST)
r->gate.s_addr = r->dest.s_addr;
}
}
return rt;
}
static struct rt_head *
add_destination_route(struct rt_head *rt, const struct interface *iface)
{
struct rt *r;
if (rt == NULL || /* failed a malloc earlier probably */
!(iface->flags & IFF_POINTOPOINT) ||
!has_option_mask(iface->options->dstmask, DHO_ROUTER))
return rt;
r = malloc(sizeof(*r));
if (r == NULL) {
syslog(LOG_ERR, "%s: %m", __func__);
ipv4_freeroutes(rt);
return NULL;
}
r->dest.s_addr = INADDR_ANY;
r->net.s_addr = INADDR_ANY;
r->gate.s_addr = D_CSTATE(iface)->dst.s_addr;
TAILQ_INSERT_HEAD(rt, r, next);
return rt;
}
/* 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 struct rt_head *
add_router_host_route(struct rt_head *rt, const struct interface *ifp)
{
struct rt *rtp, *rtn;
const char *cp, *cp2, *cp3, *cplim;
if (rt == NULL) /* earlier malloc failed */
return NULL;
TAILQ_FOREACH(rtp, rt, next) {
if (rtp->dest.s_addr != INADDR_ANY)
continue;
/* Scan for a route to match */
TAILQ_FOREACH(rtn, rt, next) {
if (rtn == rtp)
break;
/* match host */
if (rtn->dest.s_addr == rtp->gate.s_addr)
break;
/* match subnet */
cp = (const char *)&rtp->gate.s_addr;
cp2 = (const char *)&rtn->dest.s_addr;
cp3 = (const char *)&rtn->net.s_addr;
cplim = cp3 + sizeof(rtn->net.s_addr);
while (cp3 < cplim) {
if ((*cp++ ^ *cp2++) & *cp3++)
break;
}
if (cp3 == cplim)
break;
}
if (rtn != rtp)
continue;
if (ifp->flags & IFF_NOARP) {
syslog(LOG_WARNING,
"%s: forcing router %s through interface",
ifp->name, inet_ntoa(rtp->gate));
rtp->gate.s_addr = 0;
continue;
}
syslog(LOG_WARNING, "%s: router %s requires a host route",
ifp->name, inet_ntoa(rtp->gate));
rtn = malloc(sizeof(*rtn));
if (rtn == NULL) {
syslog(LOG_ERR, "%s: %m", __func__);
ipv4_freeroutes(rt);
return NULL;
}
rtn->dest.s_addr = rtp->gate.s_addr;
rtn->net.s_addr = INADDR_BROADCAST;
rtn->gate.s_addr = rtp->gate.s_addr;
TAILQ_INSERT_BEFORE(rtp, rtn, next);
}
return rt;
}
void
ipv4_buildroutes(void)
{
struct rt_head *nrs, *dnr;
struct rt *or, *rt, *rtn;
struct interface *ifp;
const struct dhcp_state *state;
nrs = malloc(sizeof(*nrs));
if (nrs == NULL) {
syslog(LOG_ERR, "%s: %m", __func__);
return;
}
TAILQ_INIT(nrs);
TAILQ_FOREACH(ifp, ifaces, next) {
state = D_CSTATE(ifp);
if (state == NULL || state->new == NULL)
continue;
dnr = get_routes(ifp);
dnr = massage_host_routes(dnr, ifp);
dnr = add_subnet_route(dnr, ifp);
#ifdef IPV4_LOOPBACK_ROUTE
dnr = add_loopback_route(dnr, ifp);
#endif
if (ifp->options->options & DHCPCD_GATEWAY) {
dnr = add_router_host_route(dnr, ifp);
dnr = add_destination_route(dnr, ifp);
}
if (dnr == NULL) /* failed to malloc all new routes */
continue;
TAILQ_FOREACH_SAFE(rt, dnr, next, rtn) {
rt->iface = ifp;
rt->metric = ifp->metric;
/* Is this route already in our table? */
if ((find_route(nrs, rt, NULL)) != NULL)
continue;
rt->src.s_addr = state->addr.s_addr;
/* Do we already manage it? */
if ((or = find_route(routes, rt, NULL))) {
if (or->iface != ifp ||
or->src.s_addr != state->addr.s_addr ||
rt->gate.s_addr != or->gate.s_addr ||
rt->metric != or->metric)
{
if (c_route(or, rt) != 0)
continue;
}
TAILQ_REMOVE(routes, or, next);
free(or);
} else {
if (n_route(rt) != 0)
continue;
}
TAILQ_REMOVE(dnr, rt, next);
TAILQ_INSERT_TAIL(nrs, rt, next);
}
ipv4_freeroutes(dnr);
}
/* Remove old routes we used to manage */
TAILQ_FOREACH(rt, routes, next) {
if (find_route(nrs, rt, NULL) == NULL)
d_route(rt);
}
ipv4_freeroutes(routes);
routes = nrs;
}
static int
delete_address1(struct interface *ifp,
const struct in_addr *addr, const struct in_addr *net)
{
int r;
struct ipv4_state *state;
struct ipv4_addr *ap;
syslog(LOG_DEBUG, "%s: deleting IP address %s/%d",
ifp->name, inet_ntoa(*addr), inet_ntocidr(*net));
r = ipv4_deleteaddress(ifp, addr, net);
if (r == -1 && errno != EADDRNOTAVAIL && errno != ENXIO &&
errno != ENODEV)
syslog(LOG_ERR, "%s: %s: %m", ifp->name, __func__);
state = IPV4_STATE(ifp);
TAILQ_FOREACH(ap, &state->addrs, next) {
if (ap->addr.s_addr == addr->s_addr &&
ap->net.s_addr == net->s_addr)
{
TAILQ_REMOVE(&state->addrs, ap, next);
free(ap);
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;
if (ifo->options & DHCPCD_INFORM ||
(ifo->options & DHCPCD_STATIC && ifo->req_addr.s_addr == 0))
return 0;
r = delete_address1(ifp, &state->addr, &state->net);
state->addr.s_addr = 0;
state->net.s_addr = 0;
return r;
}
static 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) {
syslog(LOG_ERR, "%s: %m", __func__);
return NULL;
}
TAILQ_INIT(&state->addrs);
}
return state;
}
void
ipv4_applyaddr(void *arg)
{
struct interface *ifp = arg;
struct dhcp_state *state = D_STATE(ifp);
struct dhcp_message *dhcp;
struct dhcp_lease *lease;
struct if_options *ifo = ifp->options;
struct ipv4_addr *ap;
struct ipv4_state *istate;
struct rt *rt;
int r;
/* As we are now adjusting an interface, we need to ensure
* we have them in the right order for routing and configuration. */
sort_interfaces();
if (state == NULL)
return;
dhcp = state->new;
lease = &state->lease;
if (dhcp == NULL) {
if ((ifo->options & (DHCPCD_EXITING | DHCPCD_PERSISTENT)) !=
(DHCPCD_EXITING | DHCPCD_PERSISTENT))
{
ipv4_buildroutes();
if (state->addr.s_addr != 0)
delete_address(ifp);
script_runreason(ifp, state->reason);
}
return;
}
/* If the netmask is different, delete the addresss */
ap = ipv4_findaddr(ifp, &lease->addr, NULL);
if (ap && ap->net.s_addr != lease->net.s_addr)
delete_address1(ifp, &ap->addr, &ap->net);
if (ipv4_findaddr(ifp, &lease->addr, &lease->net))
syslog(LOG_DEBUG, "%s: IP address %s/%d already exists",
ifp->name, inet_ntoa(lease->addr),
inet_ntocidr(lease->net));
else {
syslog(LOG_DEBUG, "%s: adding IP address %s/%d",
ifp->name, inet_ntoa(lease->addr),
inet_ntocidr(lease->net));
if (ifo->options & DHCPCD_NOALIAS)
r = ipv4_setaddress(ifp,
&lease->addr, &lease->net, &lease->brd);
else
r = ipv4_addaddress(ifp,
&lease->addr, &lease->net, &lease->brd);
if (r == -1 && errno != EEXIST) {
syslog(LOG_ERR, "%s: ipv4_addaddress: %m", __func__);
return;
}
istate = ipv4_getstate(ifp);
ap = malloc(sizeof(*ap));
ap->addr = lease->addr;
ap->net = lease->net;
ap->dst.s_addr = INADDR_ANY;
TAILQ_INSERT_TAIL(&istate->addrs, ap, next);
}
/* Now delete the old address if different */
if (state->addr.s_addr != lease->addr.s_addr &&
state->addr.s_addr != 0)
delete_address(ifp);
state->addr.s_addr = lease->addr.s_addr;
state->net.s_addr = lease->net.s_addr;
/* We need to delete the subnet route to have our metric or
* prefer the interface. */
rt = get_subnet_route(dhcp);
if (rt != NULL) {
rt->iface = ifp;
rt->metric = 0;
if (!find_route(routes, rt, NULL))
ipv4_deleteroute(rt);
free(rt);
}
ipv4_buildroutes();
if (!state->lease.frominfo &&
!(ifo->options & (DHCPCD_INFORM | DHCPCD_STATIC)))
if (write_lease(ifp, dhcp) == -1)
syslog(LOG_ERR, "%s: write_lease: %m", __func__);
script_runreason(ifp, state->reason);
}
void
ipv4_handleifa(int type, struct if_head *ifs, const char *ifname,
const struct in_addr *addr, const struct in_addr *net,
const struct in_addr *dst)
{
struct interface *ifp;
struct ipv4_state *state;
struct ipv4_addr *ap;
if (ifs == NULL)
ifs = ifaces;
if (ifs == NULL)
return;
if (addr->s_addr == INADDR_ANY)
return;
TAILQ_FOREACH(ifp, ifs, next) {
if (strcmp(ifp->name, ifname) == 0)
break;
}
if (ifp == NULL)
return;
state = ipv4_getstate(ifp);
if (state == NULL)
return;
ap = ipv4_findaddr(ifp, addr, net);
if (type == RTM_NEWADDR && ap == NULL) {
ap = malloc(sizeof(*ap));
if (ap == NULL) {
syslog(LOG_ERR, "%s: %m", __func__);
return;
}
ap->addr.s_addr = addr->s_addr;
ap->net.s_addr = net->s_addr;
if (dst)
ap->dst.s_addr = dst->s_addr;
else
ap->dst.s_addr = INADDR_ANY;
TAILQ_INSERT_TAIL(&state->addrs, ap, next);
} else if (type == RTM_DELADDR) {
if (ap == NULL)
return;
TAILQ_REMOVE(&state->addrs, ap, next);
free(ap);
}
dhcp_handleifa(type, ifp, addr, net, dst);
}
void
ipv4_free(struct interface *ifp)
{
struct ipv4_state *state;
struct ipv4_addr *addr;
state = IPV4_STATE(ifp);
if (state) {
while ((addr = TAILQ_FIRST(&state->addrs))) {
TAILQ_REMOVE(&state->addrs, addr, next);
free(addr);
}
free(state);
}
}
