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NetBSD/usr.bin/rump_dhcpclient/configure.c

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/*
* dhcpcd - DHCP client daemon
* Copyright (c) 2006-2010 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/stat.h>
#include <sys/uio.h>
#include <sys/wait.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <ctype.h>
#include <errno.h>
#include <signal.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <rump/rump_syscalls.h>
#include "common.h"
#include "configure.h"
#include "dhcp.h"
#include "if-options.h"
#include "net.h"
/* Some systems have route metrics */
#ifndef HAVE_ROUTE_METRIC
# ifdef __linux__
# define HAVE_ROUTE_METRIC 1
# endif
# ifndef HAVE_ROUTE_METRIC
# define HAVE_ROUTE_METRIC 0
# endif
#endif
static struct rt *routes;
static struct rt *
find_route(struct rt *rts, const struct rt *r, struct rt **lrt,
const struct rt *srt)
{
struct rt *rt;
if (lrt)
*lrt = NULL;
for (rt = rts; rt; rt = rt->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;
if (lrt)
*lrt = rt;
}
return NULL;
}
static void
desc_route(const char *cmd, const struct rt *rt, const char *ifname)
{
char addr[sizeof("000.000.000.000") + 1];
strlcpy(addr, inet_ntoa(rt->dest), sizeof(addr));
if (rt->gate.s_addr == INADDR_ANY)
fprintf(stderr, "%s: %s route to %s/%d\n", ifname, cmd,
addr, inet_ntocidr(rt->net));
else if (rt->gate.s_addr == rt->dest.s_addr &&
rt->net.s_addr == INADDR_BROADCAST)
fprintf(stderr, "%s: %s host route to %s\n", ifname, cmd,
addr);
else if (rt->dest.s_addr == INADDR_ANY && rt->net.s_addr == INADDR_ANY)
fprintf(stderr, "%s: %s default route via %s\n", ifname, cmd,
inet_ntoa(rt->gate));
else
fprintf(stderr, "%s: %s route to %s/%d via %s\n", 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
route_deleted(const struct rt *rt)
{
struct rt *f, *l;
f = find_route(routes, rt, &l, NULL);
if (f == NULL)
return 0;
desc_route("removing", f, f->iface->name);
if (l)
l->next = f->next;
else
routes = f->next;
free(f);
return 1;
}
static int
n_route(struct rt *rt, const struct interface *iface)
{
/* Don't set default routes if not asked to */
if (rt->dest.s_addr == 0 &&
rt->net.s_addr == 0 &&
!(iface->state->options->options & DHCPCD_GATEWAY))
return -1;
desc_route("adding", rt, iface->name);
if (!add_route(iface, &rt->dest, &rt->net, &rt->gate, iface->metric))
return 0;
if (errno == EEXIST) {
/* Pretend we added the subnet route */
if (rt->dest.s_addr == (iface->addr.s_addr & iface->net.s_addr) &&
rt->net.s_addr == iface->net.s_addr &&
rt->gate.s_addr == 0)
return 0;
else
return -1;
}
fprintf(stderr, "%s: add_route failed: %d\n", iface->name, errno);
return -1;
}
static int
c_route(struct rt *ort, struct rt *nrt, const struct interface *iface)
{
/* Don't set default routes if not asked to */
if (nrt->dest.s_addr == 0 &&
nrt->net.s_addr == 0 &&
!(iface->state->options->options & DHCPCD_GATEWAY))
return -1;
desc_route("changing", nrt, iface->name);
/* We delete and add the route so that we can change metric.
* This also has the nice side effect of flushing ARP entries so
* we don't have to do that manually. */
del_route(ort->iface, &ort->dest, &ort->net, &ort->gate,
ort->iface->metric);
if (!add_route(iface, &nrt->dest, &nrt->net, &nrt->gate,
iface->metric))
return 0;
fprintf(stderr, "%s: add_route failed: %d\n", iface->name, errno);
return -1;
}
static int
d_route(struct rt *rt, const struct interface *iface, int metric)
{
int retval;
desc_route("deleting", rt, iface->name);
retval = del_route(iface, &rt->dest, &rt->net, &rt->gate, metric);
if (retval != 0 && errno != ENOENT && errno != ESRCH)
fprintf(stderr,"%s: del_route: %d\n", iface->name, errno);
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 = get_netmask(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 *
add_subnet_route(struct rt *rt, const struct interface *iface)
{
struct rt *r;
if (iface->net.s_addr == INADDR_BROADCAST ||
iface->net.s_addr == INADDR_ANY ||
(iface->state->options->options &
(DHCPCD_INFORM | DHCPCD_STATIC) &&
iface->state->options->req_addr.s_addr == INADDR_ANY))
return rt;
r = xmalloc(sizeof(*r));
r->dest.s_addr = iface->addr.s_addr & iface->net.s_addr;
r->net.s_addr = iface->net.s_addr;
r->gate.s_addr = 0;
r->next = rt;
return r;
}
static struct rt *
get_routes(const struct interface *iface)
{
struct rt *rt, *nrt = NULL, *r = NULL;
if (iface->state->options->routes != NULL) {
for (rt = iface->state->options->routes;
rt != NULL;
rt = rt->next)
{
if (rt->gate.s_addr == 0)
break;
if (r == NULL)
r = nrt = xmalloc(sizeof(*r));
else {
r->next = xmalloc(sizeof(*r));
r = r->next;
}
memcpy(r, rt, sizeof(*r));
r->next = NULL;
}
return nrt;
}
return get_option_routes(iface->state->new,
iface->name, &iface->state->options->options);
}
/* 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 *
massage_host_routes(struct rt *rt, const struct interface *iface)
{
struct rt *r;
for (r = rt; r; r = r->next)
if (r->gate.s_addr == iface->addr.s_addr &&
r->net.s_addr == INADDR_BROADCAST)
r->gate.s_addr = r->dest.s_addr;
return rt;
}
static struct rt *
add_destination_route(struct rt *rt, const struct interface *iface)
{
struct rt *r;
if (!(iface->flags & IFF_POINTOPOINT) ||
!has_option_mask(iface->state->options->dstmask, DHO_ROUTER))
return rt;
r = xmalloc(sizeof(*r));
r->dest.s_addr = INADDR_ANY;
r->net.s_addr = INADDR_ANY;
r->gate.s_addr = iface->dst.s_addr;
r->next = rt;
return r;
}
/* 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 *
add_router_host_route(struct rt *rt, const struct interface *ifp)
{
struct rt *rtp, *rtl, *rtn;
const char *cp, *cp2, *cp3, *cplim;
for (rtp = rt, rtl = NULL; rtp; rtl = rtp, rtp = rtp->next) {
if (rtp->dest.s_addr != INADDR_ANY)
continue;
/* Scan for a route to match */
for (rtn = rt; rtn != rtp; rtn = rtn->next) {
/* 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) {
fprintf(stderr,
"%s: forcing router %s through interface\n",
ifp->name, inet_ntoa(rtp->gate));
rtp->gate.s_addr = 0;
continue;
}
fprintf(stderr, "%s: router %s requires a host route\n",
ifp->name, inet_ntoa(rtp->gate));
rtn = xmalloc(sizeof(*rtn));
rtn->dest.s_addr = rtp->gate.s_addr;
rtn->net.s_addr = INADDR_BROADCAST;
rtn->gate.s_addr = rtp->gate.s_addr;
rtn->next = rtp;
if (rtl == NULL)
rt = rtn;
else
rtl->next = rtn;
}
return rt;
}
void
build_routes(void)
{
struct rt *nrs = NULL, *dnr, *or, *rt, *rtn, *rtl, *lrt = NULL;
const struct interface *ifp;
for (ifp = ifaces; ifp; ifp = ifp->next) {
if (ifp->state->new == NULL)
continue;
dnr = get_routes(ifp);
dnr = massage_host_routes(dnr, ifp);
dnr = add_subnet_route(dnr, ifp);
dnr = add_router_host_route(dnr, ifp);
dnr = add_destination_route(dnr, ifp);
for (rt = dnr; rt && (rtn = rt->next, 1); lrt = rt, rt = rtn) {
rt->iface = ifp;
/* Is this route already in our table? */
if ((find_route(nrs, rt, NULL, NULL)) != NULL)
continue;
/* Do we already manage it? */
if ((or = find_route(routes, rt, &rtl, NULL))) {
if (or->iface != ifp ||
rt->gate.s_addr != or->gate.s_addr)
{
if (c_route(or, rt, ifp) != 0)
continue;
}
if (rtl != NULL)
rtl->next = or->next;
else
routes = or->next;
free(or);
} else {
if (n_route(rt, ifp) != 0)
continue;
}
if (dnr == rt)
dnr = rtn;
else if (lrt)
lrt->next = rtn;
rt->next = nrs;
nrs = rt;
}
free_routes(dnr);
}
/* Remove old routes we used to manage */
for (rt = routes; rt; rt = rt->next) {
if (find_route(nrs, rt, NULL, NULL) == NULL)
d_route(rt, rt->iface, rt->iface->metric);
}
free_routes(routes);
routes = nrs;
}
static int
delete_address(struct interface *iface)
{
int retval;
struct if_options *ifo;
ifo = iface->state->options;
if (ifo->options & DHCPCD_INFORM ||
(ifo->options & DHCPCD_STATIC && ifo->req_addr.s_addr == 0))
return 0;
fprintf(stderr, "%s: deleting IP address %s/%d\n",
iface->name,
inet_ntoa(iface->addr),
inet_ntocidr(iface->net));
retval = del_address(iface, &iface->addr, &iface->net);
if (retval == -1 && errno != EADDRNOTAVAIL)
fprintf(stderr, "del_address failed: %d\n", errno);
iface->addr.s_addr = 0;
iface->net.s_addr = 0;
return retval;
}
int
configure(struct interface *iface)
{
struct dhcp_message *dhcp = iface->state->new;
struct dhcp_lease *lease = &iface->state->lease;
struct if_options *ifo = iface->state->options;
struct rt *rt;
/* This also changes netmask */
if (!(ifo->options & DHCPCD_INFORM) ||
!has_address(iface->name, &lease->addr, &lease->net))
{
fprintf(stderr, "%s: adding IP address %s/%d\n",
iface->name, inet_ntoa(lease->addr),
inet_ntocidr(lease->net));
if (add_address(iface,
&lease->addr, &lease->net, &lease->brd) == -1 &&
errno != EEXIST)
{
fprintf(stderr, "add_address failed\n");
return -1;
}
}
/* Now delete the old address if different */
if (iface->addr.s_addr != lease->addr.s_addr &&
iface->addr.s_addr != 0)
delete_address(iface);
iface->addr.s_addr = lease->addr.s_addr;
iface->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 = iface;
if (!find_route(routes, rt, NULL, NULL))
del_route(iface, &rt->dest, &rt->net, &rt->gate, 0);
free(rt);
}
build_routes();
fprintf(stderr, "lease time: ");
if (lease->leasetime == ~0U)
fprintf(stderr, "infinite\n");
else
fprintf(stderr, "%u seconds (%.2f days)\n",
lease->leasetime, lease->leasetime / (60*60*24+.0));
return 0;
}
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