/* * 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 HOSTNAME_PROP_NAME[] = "net.hostname"; 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'}; char daemon_cmd[PROPERTY_VALUE_MAX * 2]; 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 */ if (property_get(HOSTNAME_PROP_NAME, prop_value, NULL) && (prop_value[0] != '\0')) snprintf(daemon_cmd, sizeof(daemon_cmd), "%s:-h %s %s", DAEMON_NAME, prop_value, interface); else snprintf(daemon_cmd, sizeof(daemon_cmd), "%s:%s", DAEMON_NAME, interface); memset(prop_value, '\0', PROPERTY_VALUE_MAX); property_set(ctrl_prop, daemon_cmd); 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; }