/*
* Copyright 2008, The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/* Utilities for managing the dhcpcd DHCP client daemon */
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <arpa/inet.h>
#include <netinet/in.h>
#include <cutils/properties.h>
static const char DAEMON_NAME[] = "dhcpcd";
static const char DAEMON_PROP_NAME[] = "init.svc.dhcpcd";
static const char DHCP_PROP_NAME_PREFIX[] = "dhcp";
static const int NAP_TIME = 1; /* wait for 1 second at a time */
/* when polling for property values */
static char errmsg[100];
/*
* Wait for a system property to be assigned a specified value.
* If desired_value is NULL, then just wait for the property to
* be created with any value. maxwait is the maximum amount of
* time in seconds to wait before giving up.
*/
static int wait_for_property(const char *name, const char *desired_value, int maxwait)
{
char value[PROPERTY_VALUE_MAX] = {'\0'};
int maxnaps = maxwait / NAP_TIME;
if (maxnaps < 1) {
maxnaps = 1;
}
while (maxnaps-- > 0) {
usleep(1000000);
if (property_get(name, value, NULL)) {
if (desired_value == NULL ||
strcmp(value, desired_value) == 0) {
return 0;
}
}
}
return -1; /* failure */
}
static void fill_ip_info(const char *interface,
in_addr_t *ipaddr,
in_addr_t *gateway,
in_addr_t *mask,
in_addr_t *dns1,
in_addr_t *dns2,
in_addr_t *server,
uint32_t *lease)
{
char prop_name[PROPERTY_KEY_MAX];
char prop_value[PROPERTY_VALUE_MAX];
struct in_addr addr;
in_addr_t iaddr;
snprintf(prop_name, sizeof(prop_name), "%s.%s.ipaddress", DHCP_PROP_NAME_PREFIX, interface);
if (property_get(prop_name, prop_value, NULL) && inet_aton(prop_value, &addr)) {
*ipaddr = addr.s_addr;
} else {
*ipaddr = 0;
}
snprintf(prop_name, sizeof(prop_name), "%s.%s.gateway", DHCP_PROP_NAME_PREFIX, interface);
if (property_get(prop_name, prop_value, NULL) && inet_aton(prop_value, &addr)) {
*gateway = addr.s_addr;
} else {
*gateway = 0;
}
snprintf(prop_name, sizeof(prop_name), "%s.%s.mask", DHCP_PROP_NAME_PREFIX, interface);
if (property_get(prop_name, prop_value, NULL) && inet_aton(prop_value, &addr)) {
*mask = addr.s_addr;
} else {
*mask = 0;
}
snprintf(prop_name, sizeof(prop_name), "%s.%s.dns1", DHCP_PROP_NAME_PREFIX, interface);
if (property_get(prop_name, prop_value, NULL) && inet_aton(prop_value, &addr)) {
*dns1 = addr.s_addr;
} else {
*dns1 = 0;
}
snprintf(prop_name, sizeof(prop_name), "%s.%s.dns2", DHCP_PROP_NAME_PREFIX, interface);
if (property_get(prop_name, prop_value, NULL) && inet_aton(prop_value, &addr)) {
*dns2 = addr.s_addr;
} else {
*dns2 = 0;
}
snprintf(prop_name, sizeof(prop_name), "%s.%s.server", DHCP_PROP_NAME_PREFIX, interface);
if (property_get(prop_name, prop_value, NULL) && inet_aton(prop_value, &addr)) {
*server = addr.s_addr;
} else {
*server = 0;
}
snprintf(prop_name, sizeof(prop_name), "%s.%s.leasetime", DHCP_PROP_NAME_PREFIX, interface);
if (property_get(prop_name, prop_value, NULL)) {
*lease = atol(prop_value);
}
}
/*
* Start the dhcp client daemon, and wait for it to finish
* configuring the interface.
*/
int dhcp_do_request(const char *interface,
in_addr_t *ipaddr,
in_addr_t *gateway,
in_addr_t *mask,
in_addr_t *dns1,
in_addr_t *dns2,
in_addr_t *server,
uint32_t *lease)
{
char result_prop_name[PROPERTY_KEY_MAX];
char prop_value[PROPERTY_VALUE_MAX] = {'\0'};
const char *ctrl_prop = "ctl.start";
const char *desired_status = "running";
snprintf(result_prop_name, sizeof(result_prop_name), "%s.%s.result",
DHCP_PROP_NAME_PREFIX,
interface);
/* Erase any previous setting of the dhcp result property */
property_set(result_prop_name, "");
/* Start the daemon and wait until it's ready */
property_set(ctrl_prop, DAEMON_NAME);
if (wait_for_property(DAEMON_PROP_NAME, desired_status, 10) < 0) {
snprintf(errmsg, sizeof(errmsg), "%s", "Timed out waiting for dhcpcd to start");
return -1;
}
/* Wait for the daemon to return a result */
if (wait_for_property(result_prop_name, NULL, 30) < 0) {
snprintf(errmsg, sizeof(errmsg), "%s", "Timed out waiting for DHCP to finish");
return -1;
}
if (!property_get(result_prop_name, prop_value, NULL)) {
/* shouldn't ever happen, given the success of wait_for_property() */
snprintf(errmsg, sizeof(errmsg), "%s", "DHCP result property was not set");
return -1;
}
if (strcmp(prop_value, "ok") == 0) {
fill_ip_info(interface, ipaddr, gateway, mask, dns1, dns2, server, lease);
return 0;
} else {
snprintf(errmsg, sizeof(errmsg), "DHCP result was %s", prop_value);
return -1;
}
}
/**
* Stop the DHCP client daemon.
*/
int dhcp_stop(const char *interface)
{
char result_prop_name[PROPERTY_KEY_MAX];
const char *ctrl_prop = "ctl.stop";
const char *desired_status = "stopped";
snprintf(result_prop_name, sizeof(result_prop_name), "%s.%s.result",
DHCP_PROP_NAME_PREFIX,
interface);
/* Stop the daemon and wait until it's reported to be stopped */
property_set(ctrl_prop, DAEMON_NAME);
if (wait_for_property(DAEMON_PROP_NAME, desired_status, 5) < 0) {
return -1;
}
property_set(result_prop_name, "failed");
return 0;
}
/**
* Release the current DHCP client lease.
*/
int dhcp_release_lease(const char *interface)
{
const char *ctrl_prop = "ctl.stop";
const char *desired_status = "stopped";
/* Stop the daemon and wait until it's reported to be stopped */
property_set(ctrl_prop, DAEMON_NAME);
if (wait_for_property(DAEMON_PROP_NAME, desired_status, 5) < 0) {
return -1;
}
return 0;
}
char *dhcp_get_errmsg() {
return errmsg;
}