| /* |
| * 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; |
| } |