/*
* dhcpcd - DHCP client daemon
* Copyright 2006-2008 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/wait.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <ctype.h>
#include <errno.h>
#include <signal.h>
#include <stdlib.h>
#include <unistd.h>
#include "config.h"
#include "common.h"
#include "configure.h"
#include "dhcp.h"
#include "dhcpcd.h"
#include "logger.h"
#include "net.h"
#include "signals.h"
#define DEFAULT_PATH "PATH=/usr/bin:/usr/sbin:/bin:/sbin"
static int
exec_script(char *const *argv, char *const *env)
{
pid_t pid;
sigset_t full;
sigset_t old;
/* OK, we need to block signals */
sigfillset(&full);
sigprocmask(SIG_SETMASK, &full, &old);
signal_reset();
switch (pid = vfork()) {
case -1:
logger(LOG_ERR, "vfork: %s", strerror(errno));
break;
case 0:
sigprocmask(SIG_SETMASK, &old, NULL);
execve(argv[0], argv, env);
logger(LOG_ERR, "%s: %s", argv[0], strerror(errno));
_exit(127);
/* NOTREACHED */
}
/* Restore our signals */
signal_setup();
sigprocmask(SIG_SETMASK, &old, NULL);
return pid;
}
int
run_script(const struct options *options, const char *iface,
const char *reason,
const struct dhcp_message *dhcpn, const struct dhcp_message *dhcpo)
{
char *const argv[2] = { UNCONST(options->script), NULL };
char **env = NULL, **ep;
char *path;
ssize_t e, elen;
pid_t pid;
int status = 0;
logger(LOG_DEBUG, "executing `%s', reason %s", options->script, reason);
/* Make our env */
elen = 5;
env = xmalloc(sizeof(char *) * (elen + 1));
path = getenv("PATH");
if (path) {
e = strlen("PATH") + strlen(path) + 2;
env[0] = xmalloc(e);
snprintf(env[0], e, "PATH=%s", path);
} else
env[0] = xstrdup(DEFAULT_PATH);
e = strlen("interface") + strlen(iface) + 2;
env[1] = xmalloc(e);
snprintf(env[1], e, "interface=%s", iface);
e = strlen("reason") + strlen(reason) + 2;
env[2] = xmalloc(e);
snprintf(env[2], e, "reason=%s", reason);
e = 20;
env[3] = xmalloc(e);
snprintf(env[3], e, "pid=%d", getpid());
env[4] = xmalloc(e);
snprintf(env[4], e, "metric=%d", options->metric);
if (dhcpo) {
e = configure_env(NULL, NULL, dhcpo, options);
if (e > 0) {
env = xrealloc(env, sizeof(char *) * (elen + e + 1));
elen += configure_env(env + elen, "old", dhcpo, options);
}
}
if (dhcpn) {
e = configure_env(NULL, NULL, dhcpn, options);
if (e > 0) {
env = xrealloc(env, sizeof(char *) * (elen + e + 1));
elen += configure_env(env + elen, "new", dhcpn, options);
}
}
/* Add our base environment */
if (options->environ) {
e = 0;
while (options->environ[e++])
;
env = xrealloc(env, sizeof(char *) * (elen + e + 1));
e = 0;
while (options->environ[e]) {
env[elen + e] = xstrdup(options->environ[e]);
e++;
}
elen += e;
}
env[elen] = '\0';
pid = exec_script(argv, env);
if (pid == -1)
status = -1;
else if (pid != 0) {
/* Wait for the script to finish */
while (waitpid(pid, &status, 0) == -1) {
if (errno != EINTR) {
logger(LOG_ERR, "waitpid: %s", strerror(errno));
status = -1;
break;
}
}
}
/* Cleanup */
ep = env;
while (*ep)
free(*ep++);
free(env);
return status;
}
static struct rt *
reverse_routes(struct rt *routes)
{
struct rt *rt;
struct rt *rtn = NULL;
while (routes) {
rt = routes->next;
routes->next = rtn;
rtn = routes;
routes = rt;
}
return rtn;
}
static int
delete_route(const struct interface *iface, struct rt *rt, int metric)
{
char *addr;
int retval;
addr = xstrdup(inet_ntoa(rt->dest));
logger(LOG_DEBUG, "deleting route %s/%d via %s",
addr, inet_ntocidr(rt->net), inet_ntoa(rt->gate));
free(addr);
retval = del_route(iface, &rt->dest, &rt->net, &rt->gate, metric);
if (retval != 0 && errno != ENOENT && errno != ESRCH)
logger(LOG_ERR," del_route: %s", strerror(errno));
return retval;
}
static int
delete_routes(struct interface *iface, int metric)
{
struct rt *rt;
struct rt *rtn;
int retval = 0;
rt = reverse_routes(iface->routes);
while (rt) {
rtn = rt->next;
retval += delete_route(iface, rt, metric);
free(rt);
rt = rtn;
}
iface->routes = NULL;
return retval;
}
static int
in_routes(const struct rt *routes, const struct rt *rt)
{
while (routes) {
if (routes->dest.s_addr == rt->dest.s_addr &&
routes->net.s_addr == rt->net.s_addr &&
routes->gate.s_addr == rt->gate.s_addr)
return 0;
routes = routes->next;
}
return -1;
}
static int
configure_routes(struct interface *iface, const struct dhcp_message *dhcp,
const struct options *options)
{
struct rt *rt, *ort;
struct rt *rtn = NULL, *nr = NULL;
int remember;
int retval = 0;
char *addr;
ort = get_option_routes(dhcp);
#ifdef IPV4LL_ALWAYSROUTE
if (options->options & DHCPCD_IPV4LL &&
IN_PRIVATE(ntohl(dhcp->yiaddr)))
{
for (rt = ort; rt; rt = rt->next) {
/* Check if we have already got a link locale route
* dished out by the DHCP server */
if (rt->dest.s_addr == htonl(LINKLOCAL_ADDR) &&
rt->net.s_addr == htonl(LINKLOCAL_MASK))
break;
rtn = rt;
}
if (!rt) {
rt = xmalloc(sizeof(*rt));
rt->dest.s_addr = htonl(LINKLOCAL_ADDR);
rt->net.s_addr = htonl(LINKLOCAL_MASK);
rt->gate.s_addr = 0;
rt->next = NULL;
if (rtn)
rtn->next = rt;
else
ort = rt;
}
}
#endif
/* Now remove old routes we no longer use.
* We should do this in reverse order. */
iface->routes = reverse_routes(iface->routes);
for (rt = iface->routes; rt; rt = rt->next)
if (in_routes(ort, rt) != 0)
delete_route(iface, rt, options->metric);
for (rt = ort; rt; rt = rt->next) {
/* Don't set default routes if not asked to */
if (rt->dest.s_addr == 0 &&
rt->net.s_addr == 0 &&
!(options->options & DHCPCD_GATEWAY))
continue;
addr = xstrdup(inet_ntoa(rt->dest));
logger(LOG_DEBUG, "adding route to %s/%d via %s",
addr, inet_ntocidr(rt->net), inet_ntoa(rt->gate));
free(addr);
remember = add_route(iface, &rt->dest,
&rt->net, &rt->gate,
options->metric);
retval += remember;
/* If we failed to add the route, we may have already added it
ourselves. If so, remember it again. */
if (remember < 0) {
if (errno != EEXIST)
logger(LOG_ERR, "add_route: %s",
strerror(errno));
if (in_routes(iface->routes, rt) == 0)
remember = 1;
}
/* This login is split from above due to the #ifdef below */
if (remember >= 0) {
if (nr) {
rtn->next = xmalloc(sizeof(*rtn));
rtn = rtn->next;
} else {
nr = rtn = xmalloc(sizeof(*rtn));
}
rtn->dest.s_addr = rt->dest.s_addr;
rtn->net.s_addr = rt->net.s_addr;
rtn->gate.s_addr = rt->gate.s_addr;
rtn->next = NULL;
}
}
free_routes(ort);
free_routes(iface->routes);
iface->routes = nr;
return retval;
}
static int
delete_address(struct interface *iface)
{
int retval;
logger(LOG_DEBUG, "deleting IP address %s/%d",
inet_ntoa(iface->addr),
inet_ntocidr(iface->net));
retval = del_address(iface->name, &iface->addr, &iface->net);
if (retval == -1 && errno != EADDRNOTAVAIL)
logger(LOG_ERR, "del_address: %s", strerror(errno));
iface->addr.s_addr = 0;
iface->net.s_addr = 0;
return retval;
}
int
configure(struct interface *iface, const char *reason,
const struct dhcp_message *dhcp, const struct dhcp_message *old,
const struct dhcp_lease *lease, const struct options *options,
int up)
{
struct in_addr addr;
struct in_addr net;
struct in_addr brd;
#ifdef __linux__
struct in_addr dest;
struct in_addr gate;
#endif
/* Grab our IP config */
if (dhcp == NULL)
up = 0;
else {
addr.s_addr = dhcp->yiaddr;
if (addr.s_addr == 0)
addr.s_addr = lease->addr.s_addr;
/* Ensure we have all the needed values */
if (get_option_addr(&net, dhcp, DHO_SUBNETMASK) == -1)
net.s_addr = get_netmask(addr.s_addr);
if (get_option_addr(&brd, dhcp, DHO_BROADCAST) == -1)
brd.s_addr = addr.s_addr | ~net.s_addr;
}
/* If we aren't up, then reset the interface as much as we can */
if (!up) {
/* Only reset things if we had set them before */
if (iface->addr.s_addr != 0) {
delete_routes(iface, options->metric);
delete_address(iface);
}
run_script(options, iface->name, reason, NULL, old);
return 0;
}
/* This also changes netmask */
if (!(options->options & DHCPCD_INFORM) ||
!has_address(iface->name, &addr, &net)) {
logger(LOG_DEBUG, "adding IP address %s/%d",
inet_ntoa(addr), inet_ntocidr(net));
if (add_address(iface->name, &addr, &net, &brd) == -1 &&
errno != EEXIST)
{
logger(LOG_ERR, "add_address: %s", strerror(errno));
return -1;
}
}
/* Now delete the old address if different */
if (iface->addr.s_addr != addr.s_addr &&
iface->addr.s_addr != 0)
delete_address(iface);
#ifdef __linux__
/* On linux, we need to change the subnet route to have our metric. */
if (iface->addr.s_addr != lease->addr.s_addr &&
options->metric > 0 && net.s_addr != INADDR_BROADCAST)
{
dest.s_addr = addr.s_addr & net.s_addr;
gate.s_addr = 0;
add_route(iface, &dest, &net, &gate, options->metric);
del_route(iface, &dest, &net, &gate, 0);
}
#endif
iface->addr.s_addr = addr.s_addr;
iface->net.s_addr = net.s_addr;
configure_routes(iface, dhcp, options);
if (!lease->frominfo)
if (write_lease(iface, dhcp) == -1)
logger(LOG_ERR, "write_lease: %s", strerror(errno));
run_script(options, iface->name, reason, dhcp, old);
return 0;
}