Brad Bishop | 7739049 | 2016-04-13 10:47:19 -0400 | [diff] [blame^] | 1 | #include <stdio.h> |
| 2 | #include <stdlib.h> |
| 3 | #include <errno.h> |
| 4 | #include <string.h> |
| 5 | #include <dirent.h> |
| 6 | #include <systemd/sd-bus.h> |
| 7 | |
| 8 | /* |
| 9 | * These are control files that are present for each led under |
| 10 | *'/sys/class/leds/<led_name>/' which are used to trigger action |
| 11 | * on the respective leds by writing predefined data. |
| 12 | */ |
| 13 | const char *power_ctrl = "brightness"; |
| 14 | const char *blink_ctrl = "trigger"; |
| 15 | const char *duty_on = "delay_on"; |
| 16 | const char *duty_off = "delay_off"; |
| 17 | |
| 18 | /* |
| 19 | * -------------------------------------------------- |
| 20 | * Given the dbus path, returns the name of the LED |
| 21 | * -------------------------------------------------- |
| 22 | */ |
| 23 | char * |
| 24 | get_led_name(const char *dbus_path) |
| 25 | { |
| 26 | char *led_name = NULL; |
| 27 | |
| 28 | /* Get the led name from /org/openbmc/control/led/<name> */ |
| 29 | led_name = strrchr(dbus_path, '/'); |
| 30 | if(led_name) |
| 31 | { |
| 32 | led_name++; |
| 33 | } |
| 34 | |
| 35 | return led_name; |
| 36 | } |
| 37 | |
| 38 | /* |
| 39 | * ------------------------------------------------------------------------- |
| 40 | * Writes the 'on / off / blink' trigger to leds. |
| 41 | * ------------------------------------------------------------------------- |
| 42 | */ |
| 43 | int |
| 44 | write_to_led(const char *name, const char *ctrl_file, const char *value) |
| 45 | { |
| 46 | /* Generic error reporter. */ |
| 47 | int rc = -1; |
| 48 | |
| 49 | /* To get /sys/class/leds/<name>/<control file> */ |
| 50 | char led_path[128] = {0}; |
| 51 | |
| 52 | int len = 0; |
| 53 | len = snprintf(led_path, sizeof(led_path), |
| 54 | "/sys/class/leds/%s/%s",name, ctrl_file); |
| 55 | if(len >= sizeof(led_path)) |
| 56 | { |
| 57 | fprintf(stderr, "Error. LED path is too long. :[%d]\n",len); |
| 58 | return rc; |
| 59 | } |
| 60 | |
| 61 | FILE *fp = fopen(led_path,"w"); |
| 62 | if(fp == NULL) |
| 63 | { |
| 64 | fprintf(stderr,"Error:[%s] opening:[%s]\n",strerror(errno),led_path); |
| 65 | return rc; |
| 66 | } |
| 67 | |
| 68 | rc = fwrite(value, strlen(value), 1, fp); |
| 69 | if(rc != 1) |
| 70 | { |
| 71 | fprintf(stderr, "Error:[%s] writing to :[%s]\n",strerror(errno),led_path); |
| 72 | } |
| 73 | |
| 74 | fclose(fp); |
| 75 | |
| 76 | /* When we get here, rc would be what it was from writing to the file */ |
| 77 | return (rc == 1) ? 0 : -1; |
| 78 | } |
| 79 | |
| 80 | /* |
| 81 | * ---------------------------------------------------------------- |
| 82 | * Router function for any LED operations that come via dbus |
| 83 | *---------------------------------------------------------------- |
| 84 | */ |
| 85 | static int |
| 86 | led_function_router(sd_bus_message *msg, void *user_data, |
| 87 | sd_bus_error *ret_error) |
| 88 | { |
| 89 | /* Generic error reporter. */ |
| 90 | int rc = -1; |
| 91 | |
| 92 | /* Extract the led name from the full dbus path */ |
| 93 | const char *led_path = sd_bus_message_get_path(msg); |
| 94 | if(led_path == NULL) |
| 95 | { |
| 96 | fprintf(stderr, "Error. LED path is empty"); |
| 97 | return sd_bus_reply_method_return(msg, "i", rc); |
| 98 | } |
| 99 | |
| 100 | char *led_name = get_led_name(led_path); |
| 101 | if(led_name == NULL) |
| 102 | { |
| 103 | fprintf(stderr, "Invalid LED name for path :[%s]\n",led_path); |
| 104 | return sd_bus_reply_method_return(msg, "i", rc); |
| 105 | } |
| 106 | |
| 107 | /* Now that we have the LED name, get the Operation. */ |
| 108 | const char *led_function = sd_bus_message_get_member(msg); |
| 109 | if(led_function == NULL) |
| 110 | { |
| 111 | fprintf(stderr, "Null LED function specificed for : [%s]\n",led_name); |
| 112 | return sd_bus_reply_method_return(msg, "i", rc); |
| 113 | } |
| 114 | |
| 115 | /* Route the user action to appropriate handlers. */ |
| 116 | if( (strcmp(led_function, "setOn") == 0) || |
| 117 | (strcmp(led_function, "setOff") == 0)) |
| 118 | { |
| 119 | rc = led_stable_state_function(led_name, led_function); |
| 120 | return sd_bus_reply_method_return(msg, "i", rc); |
| 121 | } |
| 122 | else if( (strcmp(led_function, "setBlinkFast") == 0) || |
| 123 | (strcmp(led_function, "setBlinkSlow") == 0)) |
| 124 | { |
| 125 | rc = led_default_blink(led_name, led_function); |
| 126 | return sd_bus_reply_method_return(msg, "i", rc); |
| 127 | } |
| 128 | else if(strcmp(led_function, "BlinkCustom") == 0) |
| 129 | { |
| 130 | rc = led_custom_blink(led_name, msg); |
| 131 | return sd_bus_reply_method_return(msg, "i", rc); |
| 132 | } |
| 133 | else if(strcmp(led_function, "GetLedState") == 0) |
| 134 | { |
| 135 | char value_str[10] = {0}; |
| 136 | const char *led_state = NULL; |
| 137 | |
| 138 | rc = read_led(led_name, power_ctrl, value_str, sizeof(value_str)-1); |
| 139 | if(rc >= 0) |
| 140 | { |
| 141 | /* LED is active HI */ |
| 142 | led_state = strtoul(value_str, NULL, 0) ? "On" : "Off"; |
| 143 | } |
| 144 | return sd_bus_reply_method_return(msg, "is", rc, led_state); |
| 145 | } |
| 146 | else |
| 147 | { |
| 148 | fprintf(stderr,"Invalid LED function:[%s]\n",led_function); |
| 149 | } |
| 150 | |
| 151 | return sd_bus_reply_method_return(msg, "i", rc); |
| 152 | } |
| 153 | |
| 154 | /* |
| 155 | * -------------------------------------------------------------- |
| 156 | * Turn On or Turn Off the LED |
| 157 | * -------------------------------------------------------------- |
| 158 | */ |
| 159 | int |
| 160 | led_stable_state_function(char *led_name, char *led_function) |
| 161 | { |
| 162 | /* Generic error reporter. */ |
| 163 | int rc = -1; |
| 164 | |
| 165 | const char *value = NULL; |
| 166 | if(strcmp(led_function, "setOff") == 0) |
| 167 | { |
| 168 | /* LED active low */ |
| 169 | value = "0"; |
| 170 | } |
| 171 | else if(strcmp(led_function, "setOn") == 0) |
| 172 | { |
| 173 | value = "255"; |
| 174 | } |
| 175 | else |
| 176 | { |
| 177 | fprintf(stderr,"Invalid LED stable state operation:[%s] \n",led_function); |
| 178 | return rc; |
| 179 | } |
| 180 | |
| 181 | /* |
| 182 | * Before doing anything, need to turn off the blinking |
| 183 | * if there is one in progress by writing 'none' to trigger |
| 184 | */ |
| 185 | rc = write_to_led(led_name, blink_ctrl, "none"); |
| 186 | if(rc < 0) |
| 187 | { |
| 188 | fprintf(stderr,"Error disabling blink. Function:[%s]\n", led_function); |
| 189 | return rc; |
| 190 | } |
| 191 | |
| 192 | /* |
| 193 | * Open the brightness file and write corresponding values. |
| 194 | */ |
| 195 | rc = write_to_led(led_name, power_ctrl, value); |
| 196 | if(rc < 0) |
| 197 | { |
| 198 | fprintf(stderr,"Error driving LED. Function:[%s]\n", led_function); |
| 199 | } |
| 200 | |
| 201 | return rc; |
| 202 | } |
| 203 | |
| 204 | //----------------------------------------------------------------------------------- |
| 205 | // Given the on and off duration, applies the action on the specified LED. |
| 206 | //----------------------------------------------------------------------------------- |
| 207 | int |
| 208 | blink_led(const char *led_name, const char *on_duration, const char *off_duration) |
| 209 | { |
| 210 | /* Generic error reporter */ |
| 211 | int rc = -1; |
| 212 | |
| 213 | /* Protocol demands that 'timer' be echoed to 'trigger' */ |
| 214 | rc = write_to_led(led_name, blink_ctrl, "timer"); |
| 215 | if(rc < 0) |
| 216 | { |
| 217 | fprintf(stderr,"Error writing timer to Led:[%s]\n", led_name); |
| 218 | return rc; |
| 219 | } |
| 220 | |
| 221 | /* |
| 222 | * After writing 'timer to 'trigger', 2 new files get generated namely |
| 223 | *'delay_on' and 'delay_off' which are telling the time duration for a |
| 224 | * particular LED on and off. |
| 225 | */ |
| 226 | rc = write_to_led(led_name, duty_on, on_duration); |
| 227 | if(rc < 0) |
| 228 | { |
| 229 | fprintf(stderr,"Error writing [%s] to delay_on:[%s]\n",on_duration,led_name); |
| 230 | return rc; |
| 231 | } |
| 232 | |
| 233 | rc = write_to_led(led_name, duty_off, off_duration); |
| 234 | if(rc < 0) |
| 235 | { |
| 236 | fprintf(stderr,"Error writing [%s] to delay_off:[%s]\n",off_duration,led_name); |
| 237 | } |
| 238 | |
| 239 | return rc; |
| 240 | } |
| 241 | |
| 242 | /* |
| 243 | * ---------------------------------------------------- |
| 244 | * Default blink action on the LED. |
| 245 | * ---------------------------------------------------- |
| 246 | */ |
| 247 | int |
| 248 | led_default_blink(char *led_name, char *blink_type) |
| 249 | { |
| 250 | /* Generic error reporter */ |
| 251 | int rc = -1; |
| 252 | |
| 253 | /* How long the LED needs to be in on and off state while blinking */ |
| 254 | const char *on_duration = NULL; |
| 255 | const char *off_duration = NULL; |
| 256 | if(strcmp(blink_type, "setBlinkSlow") == 0) |
| 257 | { |
| 258 | //*Delay 900 millisec before 'on' and delay 900 millisec before off */ |
| 259 | on_duration = "900"; |
| 260 | off_duration = "900"; |
| 261 | } |
| 262 | else if(strcmp(blink_type, "setBlinkFast") == 0) |
| 263 | { |
| 264 | /* Delay 200 millisec before 'on' and delay 200 millisec before off */ |
| 265 | on_duration = "200"; |
| 266 | off_duration = "200"; |
| 267 | } |
| 268 | else |
| 269 | { |
| 270 | fprintf(stderr,"Invalid blink operation:[%s]\n",blink_type); |
| 271 | return rc; |
| 272 | } |
| 273 | |
| 274 | rc = blink_led(led_name, on_duration, off_duration); |
| 275 | |
| 276 | return rc; |
| 277 | } |
| 278 | |
| 279 | /* |
| 280 | * ------------------------------------------------- |
| 281 | * Blinks at user defined 'on' and 'off' intervals. |
| 282 | * ------------------------------------------------- |
| 283 | */ |
| 284 | int |
| 285 | led_custom_blink(const char *led_name, sd_bus_message *msg) |
| 286 | { |
| 287 | /* Generic error reporter. */ |
| 288 | int rc = -1; |
| 289 | int led_len = 0; |
| 290 | |
| 291 | /* User supplied 'on' and 'off' duration converted into string */ |
| 292 | char on_duration[32] = {0}; |
| 293 | char off_duration[32] = {0}; |
| 294 | |
| 295 | /* User supplied 'on' and 'off' duration */ |
| 296 | uint32_t user_input_on = 0; |
| 297 | uint32_t user_input_off = 0; |
| 298 | |
| 299 | /* Extract values into 'ss' ( string, string) */ |
| 300 | rc = sd_bus_message_read(msg, "uu", &user_input_on, &user_input_off); |
| 301 | if(rc < 0) |
| 302 | { |
| 303 | fprintf(stderr, "Failed to read 'on' and 'off' duration.[%s]\n", strerror(-rc)); |
| 304 | } |
| 305 | else |
| 306 | { |
| 307 | /* |
| 308 | * Converting user supplied integer arguments into string as required by |
| 309 | * sys interface. The top level REST will make sure that an error is |
| 310 | * thrown right away on invalid inputs. However, REST is allowing the |
| 311 | * unsigned decimal and floating numbers but when its received here, its |
| 312 | * received as decimal so no input validation needed. |
| 313 | */ |
| 314 | led_len = snprintf(on_duration, sizeof(on_duration), |
| 315 | "%d",user_input_on); |
| 316 | if(led_len >= sizeof(on_duration)) |
| 317 | { |
| 318 | fprintf(stderr, "Error. Blink ON duration is too long. :[%d]\n",led_len); |
| 319 | return rc; |
| 320 | } |
| 321 | |
| 322 | led_len = snprintf(off_duration, sizeof(off_duration), |
| 323 | "%d",user_input_off); |
| 324 | if(led_len >= sizeof(off_duration)) |
| 325 | { |
| 326 | fprintf(stderr, "Error. Blink OFF duration is too long. :[%d]\n",led_len); |
| 327 | return rc; |
| 328 | } |
| 329 | |
| 330 | /* We are good here.*/ |
| 331 | rc = blink_led(led_name, on_duration, off_duration); |
| 332 | } |
| 333 | return rc; |
| 334 | } |
| 335 | |
| 336 | /* |
| 337 | * --------------------------------------------------------------- |
| 338 | * Gets the current value of passed in LED file |
| 339 | * Mainly used for reading 'brightness' |
| 340 | * NOTE : It is the responsibility of the caller to allocate |
| 341 | * sufficient space for buffer. This will read upto user supplied |
| 342 | * size -or- entire contents of file whichever is smaller |
| 343 | * ---------------------------------------------------------------- |
| 344 | */ |
| 345 | int |
| 346 | read_led(const char *name, const char *ctrl_file, |
| 347 | void *value, const size_t len) |
| 348 | { |
| 349 | /* Generic error reporter. */ |
| 350 | int rc = -1; |
| 351 | int count = 0; |
| 352 | |
| 353 | if(value == NULL || len <= 0) |
| 354 | { |
| 355 | fprintf(stderr, "Invalid buffer passed to LED read\n"); |
| 356 | return rc; |
| 357 | } |
| 358 | |
| 359 | /* To get /sys/class/leds/<name>/<control file> */ |
| 360 | char led_path[128] = {0}; |
| 361 | |
| 362 | int led_len = 0; |
| 363 | led_len = snprintf(led_path, sizeof(led_path), |
| 364 | "/sys/class/leds/%s/%s",name, ctrl_file); |
| 365 | if(led_len >= sizeof(led_path)) |
| 366 | { |
| 367 | fprintf(stderr, "Error. LED path is too long. :[%d]\n",led_len); |
| 368 | return rc; |
| 369 | } |
| 370 | |
| 371 | FILE *fp = fopen(led_path,"rb"); |
| 372 | if(fp == NULL) |
| 373 | { |
| 374 | fprintf(stderr,"Error:[%s] opening:[%s]\n",strerror(errno),led_path); |
| 375 | return rc; |
| 376 | } |
| 377 | |
| 378 | char *sysfs_value = (char *)value; |
| 379 | while(!feof(fp) && (count < len)) |
| 380 | { |
| 381 | sysfs_value[count++] = fgetc(fp); |
| 382 | } |
| 383 | |
| 384 | fclose(fp); |
| 385 | return 0; |
| 386 | } |
| 387 | |
| 388 | /* |
| 389 | * ----------------------------------------------- |
| 390 | * Dbus Services offered by this LED controller |
| 391 | * ----------------------------------------------- |
| 392 | */ |
| 393 | static const sd_bus_vtable led_control_vtable[] = |
| 394 | { |
| 395 | SD_BUS_VTABLE_START(0), |
| 396 | SD_BUS_METHOD("setOn", "", "i", &led_function_router, SD_BUS_VTABLE_UNPRIVILEGED), |
| 397 | SD_BUS_METHOD("setOff", "", "i", &led_function_router, SD_BUS_VTABLE_UNPRIVILEGED), |
| 398 | SD_BUS_METHOD("setBlinkFast", "", "i", &led_function_router, SD_BUS_VTABLE_UNPRIVILEGED), |
| 399 | SD_BUS_METHOD("setBlinkSlow", "", "i", &led_function_router, SD_BUS_VTABLE_UNPRIVILEGED), |
| 400 | SD_BUS_METHOD("GetLedState", "", "is", &led_function_router, SD_BUS_VTABLE_UNPRIVILEGED), |
| 401 | SD_BUS_METHOD("BlinkCustom", "uu", "i", &led_function_router, SD_BUS_VTABLE_UNPRIVILEGED), |
| 402 | SD_BUS_VTABLE_END, |
| 403 | }; |
| 404 | |
| 405 | /* |
| 406 | * --------------------------------------------- |
| 407 | * Interested in all files except standard ones |
| 408 | * --------------------------------------------- |
| 409 | */ |
| 410 | int |
| 411 | led_select(const struct dirent *entry) |
| 412 | { |
| 413 | if( (strcmp(entry->d_name, ".") == 0) || |
| 414 | (strcmp(entry->d_name, "..") == 0)) |
| 415 | { |
| 416 | return 0; |
| 417 | } |
| 418 | return 1; |
| 419 | } |
| 420 | |
| 421 | /* |
| 422 | * ------------------------------------------------ |
| 423 | * Called as part of setting up skeleton services. |
| 424 | * ----------------------------------------------- |
| 425 | */ |
| 426 | int |
| 427 | start_led_services() |
| 428 | { |
| 429 | /* Generic error reporter. */ |
| 430 | int rc = -1; |
| 431 | int num_leds = 0; |
| 432 | int count_leds = 0; |
| 433 | |
| 434 | /* Bus and slot where we are offering the LED dbus service. */ |
| 435 | sd_bus *bus_type = NULL; |
| 436 | sd_bus_slot *led_slot = NULL; |
| 437 | |
| 438 | /* For walking '/sys/class/leds/' looking for names of LED.*/ |
| 439 | struct dirent **led_list; |
| 440 | |
| 441 | /* Get a hook onto system bus. */ |
| 442 | rc = sd_bus_open_system(&bus_type); |
| 443 | if(rc < 0) |
| 444 | { |
| 445 | fprintf(stderr,"Error opening system bus.\n"); |
| 446 | return rc; |
| 447 | } |
| 448 | |
| 449 | count_leds = num_leds = scandir("/sys/class/leds/", |
| 450 | &led_list, led_select, alphasort); |
| 451 | if(num_leds <= 0) |
| 452 | { |
| 453 | fprintf(stderr,"No LEDs present in the system\n"); |
| 454 | |
| 455 | sd_bus_slot_unref(led_slot); |
| 456 | sd_bus_unref(bus_type); |
| 457 | return rc; |
| 458 | } |
| 459 | |
| 460 | /* Fully qualified Dbus object for a particular LED */ |
| 461 | char led_object[128] = {0}; |
| 462 | int len = 0; |
| 463 | |
| 464 | /* For each led present, announce the service on dbus. */ |
| 465 | while(num_leds--) |
| 466 | { |
| 467 | memset(led_object, 0x0, sizeof(led_object)); |
| 468 | |
| 469 | len = snprintf(led_object, sizeof(led_object), "%s%s", |
| 470 | "/org/openbmc/control/led/", led_list[num_leds]->d_name); |
| 471 | |
| 472 | if(len >= sizeof(led_object)) |
| 473 | { |
| 474 | fprintf(stderr, "Error. LED object is too long:[%d]\n",len); |
| 475 | rc = -1; |
| 476 | break; |
| 477 | } |
| 478 | |
| 479 | /* Install the object */ |
| 480 | rc = sd_bus_add_object_vtable(bus_type, |
| 481 | &led_slot, |
| 482 | led_object, /* object path */ |
| 483 | "org.openbmc.Led", /* interface name */ |
| 484 | led_control_vtable, |
| 485 | NULL); |
| 486 | |
| 487 | if(rc < 0) |
| 488 | { |
| 489 | fprintf(stderr, "Failed to add object to dbus: %s\n", strerror(-rc)); |
| 490 | break; |
| 491 | } |
| 492 | } |
| 493 | |
| 494 | /* Done with all registration. */ |
| 495 | while(count_leds > 0) |
| 496 | { |
| 497 | free(led_list[--count_leds]); |
| 498 | } |
| 499 | free(led_list); |
| 500 | |
| 501 | /* If we had success in adding the providers, request for a bus name. */ |
| 502 | if(rc == 0) |
| 503 | { |
| 504 | /* Take one in OpenBmc */ |
| 505 | rc = sd_bus_request_name(bus_type, "org.openbmc.control.led", 0); |
| 506 | if(rc < 0) |
| 507 | { |
| 508 | fprintf(stderr, "Failed to acquire service name: %s\n", strerror(-rc)); |
| 509 | } |
| 510 | else |
| 511 | { |
| 512 | for(;;) |
| 513 | { |
| 514 | /* Process requests */ |
| 515 | rc = sd_bus_process(bus_type, NULL); |
| 516 | if(rc < 0) |
| 517 | { |
| 518 | fprintf(stderr, "Failed to process bus: %s\n", strerror(-rc)); |
| 519 | break; |
| 520 | } |
| 521 | if(rc > 0) |
| 522 | { |
| 523 | continue; |
| 524 | } |
| 525 | |
| 526 | rc = sd_bus_wait(bus_type, (uint64_t) - 1); |
| 527 | if(rc < 0) |
| 528 | { |
| 529 | fprintf(stderr, "Failed to wait on bus: %s\n", strerror(-rc)); |
| 530 | break; |
| 531 | } |
| 532 | } |
| 533 | } |
| 534 | } |
| 535 | sd_bus_slot_unref(led_slot); |
| 536 | sd_bus_unref(bus_type); |
| 537 | |
| 538 | return rc; |
| 539 | } |
| 540 | |
| 541 | int |
| 542 | main(void) |
| 543 | { |
| 544 | int rc = 0; |
| 545 | |
| 546 | /* This call is not supposed to return. If it does, then an error */ |
| 547 | rc = start_led_services(); |
| 548 | if(rc < 0) |
| 549 | { |
| 550 | fprintf(stderr, "Error starting LED Services. Exiting"); |
| 551 | } |
| 552 | |
| 553 | return rc; |
| 554 | } |