/* * 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 #include #include #include #include #include #include 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 = 200; /* wait for 200ms 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 * 1000) / NAP_TIME; if (maxnaps < 1) { maxnaps = 1; } while (maxnaps-- > 0) { usleep(NAP_TIME * 1000); if (property_get(name, value, NULL)) { if (desired_value == NULL || strcmp(value, desired_value) == 0) { return 0; } } } return -1; /* failure */ } static int fill_ip_info(const char *interface, char *ipaddr, char *gateway, uint32_t *prefixLength, char *dns1, char *dns2, char *server, uint32_t *lease) { char prop_name[PROPERTY_KEY_MAX]; char prop_value[PROPERTY_VALUE_MAX]; snprintf(prop_name, sizeof(prop_name), "%s.%s.ipaddress", DHCP_PROP_NAME_PREFIX, interface); property_get(prop_name, ipaddr, NULL); snprintf(prop_name, sizeof(prop_name), "%s.%s.gateway", DHCP_PROP_NAME_PREFIX, interface); property_get(prop_name, gateway, NULL); snprintf(prop_name, sizeof(prop_name), "%s.%s.mask", DHCP_PROP_NAME_PREFIX, interface); if (property_get(prop_name, prop_value, NULL)) { int p; // this conversion is v4 only, but this dhcp client is v4 only anyway in_addr_t mask = ntohl(inet_addr(prop_value)); // Check netmask is a valid IP address. ntohl gives NONE response (all 1's) for // non 255.255.255.255 inputs. if we get that value check if it is legit.. if (mask == INADDR_NONE && strcmp(prop_value, "255.255.255.255") != 0) { snprintf(errmsg, sizeof(errmsg), "DHCP gave invalid net mask %s", prop_value); return -1; } for (p = 0; p < 32; p++) { if (mask == 0) break; // check for non-contiguous netmask, e.g., 255.254.255.0 if ((mask & 0x80000000) == 0) { snprintf(errmsg, sizeof(errmsg), "DHCP gave invalid net mask %s", prop_value); return -1; } mask = mask << 1; } *prefixLength = p; } snprintf(prop_name, sizeof(prop_name), "%s.%s.dns1", DHCP_PROP_NAME_PREFIX, interface); property_get(prop_name, dns1, NULL); snprintf(prop_name, sizeof(prop_name), "%s.%s.dns2", DHCP_PROP_NAME_PREFIX, interface); property_get(prop_name, dns2, NULL); snprintf(prop_name, sizeof(prop_name), "%s.%s.server", DHCP_PROP_NAME_PREFIX, interface); property_get(prop_name, server, NULL); 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); } return 0; } static const char *ipaddr_to_string(in_addr_t addr) { struct in_addr in_addr; in_addr.s_addr = addr; return inet_ntoa(in_addr); } /* * Start the dhcp client daemon, and wait for it to finish * configuring the interface. */ int dhcp_do_request(const char *interface, char *ipaddr, char *gateway, uint32_t *prefixLength, char *dns1, char *dns2, char *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) { char dns_prop_name[PROPERTY_KEY_MAX]; if (fill_ip_info(interface, ipaddr, gateway, prefixLength, dns1, dns2, server, lease) == -1) { return -1; } /* copy dns data to system properties - TODO - remove this after we have async * notification of renewal's */ snprintf(dns_prop_name, sizeof(dns_prop_name), "net.%s.dns1", interface); property_set(dns_prop_name, *dns1 ? ipaddr_to_string(*dns1) : ""); snprintf(dns_prop_name, sizeof(dns_prop_name), "net.%s.dns2", interface); property_set(dns_prop_name, *dns2 ? ipaddr_to_string(*dns2) : ""); 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; }