1 /* 2 * Copyright 2008, The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 /* Utilities for managing the dhcpcd DHCP client daemon */ 18 19 #include <stdio.h> 20 #include <stdlib.h> 21 #include <string.h> 22 #include <unistd.h> 23 #include <arpa/inet.h> 24 #include <netinet/in.h> 25 26 #include <cutils/properties.h> 27 28 static const char DAEMON_NAME[] = "dhcpcd"; 29 static const char DAEMON_PROP_NAME[] = "init.svc.dhcpcd"; 30 static const char HOSTNAME_PROP_NAME[] = "net.hostname"; 31 static const char DHCP_PROP_NAME_PREFIX[] = "dhcp"; 32 static const char DHCP_CONFIG_PATH[] = "/system/etc/dhcpcd/dhcpcd.conf"; 33 static const int NAP_TIME = 200; /* wait for 200ms at a time */ 34 /* when polling for property values */ 35 static const char DAEMON_NAME_RENEW[] = "iprenew"; 36 static char errmsg[100]; 37 /* interface length for dhcpcd daemon start (dhcpcd_<interface> as defined in init.rc file) 38 * or for filling up system properties dhcpcd.<interface>.ipaddress, dhcpcd.<interface>.dns1 39 * and other properties on a successful bind 40 */ 41 #define MAX_INTERFACE_LENGTH 25 42 43 /* 44 * P2p interface names increase sequentially p2p-p2p0-1, p2p-p2p0-2.. after 45 * group formation. This does not work well with system properties which can quickly 46 * exhaust or for specifiying a dhcp start target in init which requires 47 * interface to be pre-defined in init.rc file. 48 * 49 * This function returns a common string p2p for all p2p interfaces. 50 */ 51 void get_p2p_interface_replacement(const char *interface, char *p2p_interface) { 52 /* Use p2p for any interface starting with p2p. */ 53 if (strncmp(interface, "p2p",3) == 0) { 54 strncpy(p2p_interface, "p2p", MAX_INTERFACE_LENGTH); 55 } else { 56 strncpy(p2p_interface, interface, MAX_INTERFACE_LENGTH); 57 } 58 } 59 60 /* 61 * Wait for a system property to be assigned a specified value. 62 * If desired_value is NULL, then just wait for the property to 63 * be created with any value. maxwait is the maximum amount of 64 * time in seconds to wait before giving up. 65 */ 66 static int wait_for_property(const char *name, const char *desired_value, int maxwait) 67 { 68 char value[PROPERTY_VALUE_MAX] = {'\0'}; 69 int maxnaps = (maxwait * 1000) / NAP_TIME; 70 71 if (maxnaps < 1) { 72 maxnaps = 1; 73 } 74 75 while (maxnaps-- > 0) { 76 usleep(NAP_TIME * 1000); 77 if (property_get(name, value, NULL)) { 78 if (desired_value == NULL || 79 strcmp(value, desired_value) == 0) { 80 return 0; 81 } 82 } 83 } 84 return -1; /* failure */ 85 } 86 87 static int fill_ip_info(const char *interface, 88 char *ipaddr, 89 char *gateway, 90 uint32_t *prefixLength, 91 char *dns[], 92 char *server, 93 uint32_t *lease, 94 char *vendorInfo, 95 char *domain, 96 char *mtu) 97 { 98 char prop_name[PROPERTY_KEY_MAX]; 99 char prop_value[PROPERTY_VALUE_MAX]; 100 /* Interface name after converting p2p0-p2p0-X to p2p to reuse system properties */ 101 char p2p_interface[MAX_INTERFACE_LENGTH]; 102 int x; 103 104 get_p2p_interface_replacement(interface, p2p_interface); 105 106 snprintf(prop_name, sizeof(prop_name), "%s.%s.ipaddress", DHCP_PROP_NAME_PREFIX, p2p_interface); 107 property_get(prop_name, ipaddr, NULL); 108 109 snprintf(prop_name, sizeof(prop_name), "%s.%s.gateway", DHCP_PROP_NAME_PREFIX, p2p_interface); 110 property_get(prop_name, gateway, NULL); 111 112 snprintf(prop_name, sizeof(prop_name), "%s.%s.server", DHCP_PROP_NAME_PREFIX, p2p_interface); 113 property_get(prop_name, server, NULL); 114 115 //TODO: Handle IPv6 when we change system property usage 116 if (gateway[0] == '\0' || strncmp(gateway, "0.0.0.0", 7) == 0) { 117 //DHCP server is our best bet as gateway 118 strncpy(gateway, server, PROPERTY_VALUE_MAX); 119 } 120 121 snprintf(prop_name, sizeof(prop_name), "%s.%s.mask", DHCP_PROP_NAME_PREFIX, p2p_interface); 122 if (property_get(prop_name, prop_value, NULL)) { 123 int p; 124 // this conversion is v4 only, but this dhcp client is v4 only anyway 125 in_addr_t mask = ntohl(inet_addr(prop_value)); 126 // Check netmask is a valid IP address. ntohl gives NONE response (all 1's) for 127 // non 255.255.255.255 inputs. if we get that value check if it is legit.. 128 if (mask == INADDR_NONE && strcmp(prop_value, "255.255.255.255") != 0) { 129 snprintf(errmsg, sizeof(errmsg), "DHCP gave invalid net mask %s", prop_value); 130 return -1; 131 } 132 for (p = 0; p < 32; p++) { 133 if (mask == 0) break; 134 // check for non-contiguous netmask, e.g., 255.254.255.0 135 if ((mask & 0x80000000) == 0) { 136 snprintf(errmsg, sizeof(errmsg), "DHCP gave invalid net mask %s", prop_value); 137 return -1; 138 } 139 mask = mask << 1; 140 } 141 *prefixLength = p; 142 } 143 144 for (x=0; dns[x] != NULL; x++) { 145 snprintf(prop_name, sizeof(prop_name), "%s.%s.dns%d", DHCP_PROP_NAME_PREFIX, p2p_interface, x+1); 146 property_get(prop_name, dns[x], NULL); 147 } 148 149 snprintf(prop_name, sizeof(prop_name), "%s.%s.leasetime", DHCP_PROP_NAME_PREFIX, p2p_interface); 150 if (property_get(prop_name, prop_value, NULL)) { 151 *lease = atol(prop_value); 152 } 153 154 snprintf(prop_name, sizeof(prop_name), "%s.%s.vendorInfo", DHCP_PROP_NAME_PREFIX, 155 p2p_interface); 156 property_get(prop_name, vendorInfo, NULL); 157 158 snprintf(prop_name, sizeof(prop_name), "%s.%s.domain", DHCP_PROP_NAME_PREFIX, 159 p2p_interface); 160 property_get(prop_name, domain, NULL); 161 162 snprintf(prop_name, sizeof(prop_name), "%s.%s.mtu", DHCP_PROP_NAME_PREFIX, 163 p2p_interface); 164 property_get(prop_name, mtu, NULL); 165 166 return 0; 167 } 168 169 static const char *ipaddr_to_string(in_addr_t addr) 170 { 171 struct in_addr in_addr; 172 173 in_addr.s_addr = addr; 174 return inet_ntoa(in_addr); 175 } 176 177 /* 178 * Start the dhcp client daemon, and wait for it to finish 179 * configuring the interface. 180 * 181 * The device init.rc file needs a corresponding entry for this work. 182 * 183 * Example: 184 * service dhcpcd_<interface> /system/bin/dhcpcd -ABKL -f dhcpcd.conf 185 */ 186 int dhcp_do_request(const char *interface, 187 char *ipaddr, 188 char *gateway, 189 uint32_t *prefixLength, 190 char *dns[], 191 char *server, 192 uint32_t *lease, 193 char *vendorInfo, 194 char *domain, 195 char *mtu) 196 { 197 char result_prop_name[PROPERTY_KEY_MAX]; 198 char daemon_prop_name[PROPERTY_KEY_MAX]; 199 char prop_value[PROPERTY_VALUE_MAX] = {'\0'}; 200 char daemon_cmd[PROPERTY_VALUE_MAX * 2 + sizeof(DHCP_CONFIG_PATH)]; 201 const char *ctrl_prop = "ctl.start"; 202 const char *desired_status = "running"; 203 /* Interface name after converting p2p0-p2p0-X to p2p to reuse system properties */ 204 char p2p_interface[MAX_INTERFACE_LENGTH]; 205 206 get_p2p_interface_replacement(interface, p2p_interface); 207 208 snprintf(result_prop_name, sizeof(result_prop_name), "%s.%s.result", 209 DHCP_PROP_NAME_PREFIX, 210 p2p_interface); 211 212 snprintf(daemon_prop_name, sizeof(daemon_prop_name), "%s_%s", 213 DAEMON_PROP_NAME, 214 p2p_interface); 215 216 /* Erase any previous setting of the dhcp result property */ 217 property_set(result_prop_name, ""); 218 219 /* Start the daemon and wait until it's ready */ 220 if (property_get(HOSTNAME_PROP_NAME, prop_value, NULL) && (prop_value[0] != '\0')) 221 snprintf(daemon_cmd, sizeof(daemon_cmd), "%s_%s:-f %s -h %s %s", DAEMON_NAME, 222 p2p_interface, DHCP_CONFIG_PATH, prop_value, interface); 223 else 224 snprintf(daemon_cmd, sizeof(daemon_cmd), "%s_%s:-f %s %s", DAEMON_NAME, 225 p2p_interface, DHCP_CONFIG_PATH, interface); 226 memset(prop_value, '\0', PROPERTY_VALUE_MAX); 227 property_set(ctrl_prop, daemon_cmd); 228 if (wait_for_property(daemon_prop_name, desired_status, 10) < 0) { 229 snprintf(errmsg, sizeof(errmsg), "%s", "Timed out waiting for dhcpcd to start"); 230 return -1; 231 } 232 233 /* Wait for the daemon to return a result */ 234 if (wait_for_property(result_prop_name, NULL, 30) < 0) { 235 snprintf(errmsg, sizeof(errmsg), "%s", "Timed out waiting for DHCP to finish"); 236 return -1; 237 } 238 239 if (!property_get(result_prop_name, prop_value, NULL)) { 240 /* shouldn't ever happen, given the success of wait_for_property() */ 241 snprintf(errmsg, sizeof(errmsg), "%s", "DHCP result property was not set"); 242 return -1; 243 } 244 if (strcmp(prop_value, "ok") == 0) { 245 char dns_prop_name[PROPERTY_KEY_MAX]; 246 if (fill_ip_info(interface, ipaddr, gateway, prefixLength, dns, 247 server, lease, vendorInfo, domain, mtu) == -1) { 248 return -1; 249 } 250 return 0; 251 } else { 252 snprintf(errmsg, sizeof(errmsg), "DHCP result was %s", prop_value); 253 return -1; 254 } 255 } 256 257 /** 258 * Stop the DHCP client daemon. 259 */ 260 int dhcp_stop(const char *interface) 261 { 262 char result_prop_name[PROPERTY_KEY_MAX]; 263 char daemon_prop_name[PROPERTY_KEY_MAX]; 264 char daemon_cmd[PROPERTY_VALUE_MAX * 2]; 265 const char *ctrl_prop = "ctl.stop"; 266 const char *desired_status = "stopped"; 267 268 char p2p_interface[MAX_INTERFACE_LENGTH]; 269 270 get_p2p_interface_replacement(interface, p2p_interface); 271 272 snprintf(result_prop_name, sizeof(result_prop_name), "%s.%s.result", 273 DHCP_PROP_NAME_PREFIX, 274 p2p_interface); 275 276 snprintf(daemon_prop_name, sizeof(daemon_prop_name), "%s_%s", 277 DAEMON_PROP_NAME, 278 p2p_interface); 279 280 snprintf(daemon_cmd, sizeof(daemon_cmd), "%s_%s", DAEMON_NAME, p2p_interface); 281 282 /* Stop the daemon and wait until it's reported to be stopped */ 283 property_set(ctrl_prop, daemon_cmd); 284 if (wait_for_property(daemon_prop_name, desired_status, 5) < 0) { 285 return -1; 286 } 287 property_set(result_prop_name, "failed"); 288 return 0; 289 } 290 291 /** 292 * Release the current DHCP client lease. 293 */ 294 int dhcp_release_lease(const char *interface) 295 { 296 char daemon_prop_name[PROPERTY_KEY_MAX]; 297 char daemon_cmd[PROPERTY_VALUE_MAX * 2]; 298 const char *ctrl_prop = "ctl.stop"; 299 const char *desired_status = "stopped"; 300 301 char p2p_interface[MAX_INTERFACE_LENGTH]; 302 303 get_p2p_interface_replacement(interface, p2p_interface); 304 305 snprintf(daemon_prop_name, sizeof(daemon_prop_name), "%s_%s", 306 DAEMON_PROP_NAME, 307 p2p_interface); 308 309 snprintf(daemon_cmd, sizeof(daemon_cmd), "%s_%s", DAEMON_NAME, p2p_interface); 310 311 /* Stop the daemon and wait until it's reported to be stopped */ 312 property_set(ctrl_prop, daemon_cmd); 313 if (wait_for_property(daemon_prop_name, desired_status, 5) < 0) { 314 return -1; 315 } 316 return 0; 317 } 318 319 char *dhcp_get_errmsg() { 320 return errmsg; 321 } 322 323 /** 324 * The device init.rc file needs a corresponding entry. 325 * 326 * Example: 327 * service iprenew_<interface> /system/bin/dhcpcd -n 328 * 329 */ 330 int dhcp_do_request_renew(const char *interface, 331 char *ipaddr, 332 char *gateway, 333 uint32_t *prefixLength, 334 char *dns[], 335 char *server, 336 uint32_t *lease, 337 char *vendorInfo, 338 char *domain, 339 char *mtu) 340 { 341 char result_prop_name[PROPERTY_KEY_MAX]; 342 char prop_value[PROPERTY_VALUE_MAX] = {'\0'}; 343 char daemon_cmd[PROPERTY_VALUE_MAX * 2]; 344 const char *ctrl_prop = "ctl.start"; 345 346 char p2p_interface[MAX_INTERFACE_LENGTH]; 347 348 get_p2p_interface_replacement(interface, p2p_interface); 349 350 snprintf(result_prop_name, sizeof(result_prop_name), "%s.%s.result", 351 DHCP_PROP_NAME_PREFIX, 352 p2p_interface); 353 354 /* Erase any previous setting of the dhcp result property */ 355 property_set(result_prop_name, ""); 356 357 /* Start the renew daemon and wait until it's ready */ 358 snprintf(daemon_cmd, sizeof(daemon_cmd), "%s_%s:%s", DAEMON_NAME_RENEW, 359 p2p_interface, interface); 360 memset(prop_value, '\0', PROPERTY_VALUE_MAX); 361 property_set(ctrl_prop, daemon_cmd); 362 363 /* Wait for the daemon to return a result */ 364 if (wait_for_property(result_prop_name, NULL, 30) < 0) { 365 snprintf(errmsg, sizeof(errmsg), "%s", "Timed out waiting for DHCP Renew to finish"); 366 return -1; 367 } 368 369 if (!property_get(result_prop_name, prop_value, NULL)) { 370 /* shouldn't ever happen, given the success of wait_for_property() */ 371 snprintf(errmsg, sizeof(errmsg), "%s", "DHCP Renew result property was not set"); 372 return -1; 373 } 374 if (strcmp(prop_value, "ok") == 0) { 375 return fill_ip_info(interface, ipaddr, gateway, prefixLength, dns, 376 server, lease, vendorInfo, domain, mtu); 377 } else { 378 snprintf(errmsg, sizeof(errmsg), "DHCP Renew result was %s", prop_value); 379 return -1; 380 } 381 } 382
