3 * @brief Runs the FCGI request loop to handle web interface requests.
5 * fcgi_stdio.h must be included before all else so the stdio function
6 * redirection works ok.
9 #include <fcgi_stdio.h>
10 #include <openssl/sha.h>
12 #include <sys/types.h>
24 /**The time period (in seconds) before the control key expires */
25 #define CONTROL_TIMEOUT 180
30 * Identifies build information and the current API version to the user.
31 * Also useful for testing that the API is running and identifying the
32 * sensors and actuators present.
33 * @param context The context to work in
34 * @param params User specified paramters: [actuators, sensors]
36 static void IdentifyHandler(FCGIContext *context, char *params) {
37 bool ident_sensors = false, ident_actuators = false;
38 bool has_control = FCGI_HasControl(context, getenv("COOKIE_STRING"));
41 FCGIValue values[2] = {{"sensors", &ident_sensors, FCGI_BOOL_T},
42 {"actuators", &ident_actuators, FCGI_BOOL_T}};
43 if (!FCGI_ParseRequest(context, params, values, 2))
46 FCGI_BeginJSON(context, STATUS_OK);
47 FCGI_JSONPair("description", "MCTX3420 Server API (2013)");
48 FCGI_JSONPair("build_date", __DATE__ " " __TIME__);
50 t.tv_sec = 0; t.tv_nsec = 0;
51 clock_getres(CLOCK_MONOTONIC, &t);
52 FCGI_JSONDouble("clock_getres", TIMEVAL_TO_DOUBLE(t));
53 FCGI_JSONLong("api_version", API_VERSION);
54 FCGI_JSONBool("logged_in", has_control);
55 FCGI_JSONPair("user_name", has_control ? context->user_name : "");
58 //Sensor and actuator information
60 FCGI_JSONKey("sensors");
61 FCGI_JSONValue("{\n\t\t");
62 for (i = 0; i < g_num_sensors; i++) {
64 FCGI_JSONValue(",\n\t\t");
66 FCGI_JSONValue("\"%d\" : \"%s\"", i, Sensor_GetName(i));
68 FCGI_JSONValue("\n\t}");
70 if (ident_actuators) {
71 FCGI_JSONKey("actuators");
72 FCGI_JSONValue("{\n\t\t");
73 for (i = 0; i < g_num_actuators; i++) {
75 FCGI_JSONValue(",\n\t\t");
77 FCGI_JSONValue("\"%d\" : \"%s\"", i, Actuator_GetName(i));
79 FCGI_JSONValue("\n\t}");
85 * Given an authorised user, attempt to set the control over the system.
86 * Modifies members in the context structure appropriately if successful.
87 * @param context The context to work in
88 * @param user_name - Name of the user
89 * @param user_type - Type of the user, passed after successful authentication
90 * @return true on success, false otherwise (eg someone else already in control)
92 bool FCGI_LockControl(FCGIContext *context, const char * user_name, UserType user_type)
95 time_t now = time(NULL);
96 bool expired = now - context->control_timestamp > CONTROL_TIMEOUT;
98 // Can't lock control if: User not actually logged in (sanity), or key is still valid and the user is not an admin
99 if (user_type == USER_UNAUTH ||
100 (user_type != USER_ADMIN && !expired && *(context->control_key) != '\0'))
103 // Release any existing control (if any)
104 FCGI_ReleaseControl(context);
107 context->control_timestamp = now;
109 // Generate a SHA1 hash for the user
111 unsigned char sha1[20];
114 SHA1_Update(&sha1ctx, &now, sizeof(now));
115 SHA1_Update(&sha1ctx, &i, sizeof(i));
116 SHA1_Final(sha1, &sha1ctx);
117 for (i = 0; i < sizeof(sha1); i++)
118 sprintf(context->control_key + i * 2, "%02x", sha1[i]);
120 // Set the IP address
121 snprintf(context->control_ip, 16, "%s", getenv("REMOTE_ADDR"));
123 int uname_len = strlen(user_name);
124 if (snprintf(context->user_name, sizeof(context->user_name), "%s", user_name) < uname_len)
126 Log(LOGERR, "Username at %d characters too long (limit %d)", uname_len, sizeof(context->user_name));
130 context->user_type = user_type;
132 if (mkdir(user_name, 0777) != 0 && errno != EEXIST)
134 Log(LOGERR, "Couldn't create user directory %s/%s - %s", g_options.root_dir, user_name, strerror(errno));
143 * Given an FCGIContext, determines if the current user (as specified by
144 * the key) has control or not. If validated, the context control_timestamp is
146 * @param context The context to work in
147 * @param key The control key to be validated.
148 * @return TRUE if authorized, FALSE if not.
150 bool FCGI_HasControl(FCGIContext *context, const char *key) {
151 time_t now = time(NULL);
152 int result = (now - context->control_timestamp) <= CONTROL_TIMEOUT &&
153 key != NULL && context->control_key[0] != '\0' &&
154 !strcmp(context->control_key, key);
156 context->control_timestamp = now; //Update the control_timestamp
163 * Revokes the current control key, if present.
164 * @param context The context to work in
166 void FCGI_ReleaseControl(FCGIContext *context) {
167 *(context->control_key) = 0;
168 // Note: context->user_name should *not* be cleared
173 * Extracts a key/value pair from a request string.
174 * Note that the input is modified by this function.
175 * @param in The string from which to extract the pair
176 * @param key A pointer to a variable to hold the key string
177 * @param value A pointer to a variable to hold the value string
178 * @return A pointer to the start of the next search location, or NULL if
179 * the EOL is reached.
181 char *FCGI_KeyPair(char *in, const char **key, const char **value)
184 if (!in || !*in) { //Invalid input or string is EOL
189 //Find either = or &, whichever comes first
190 if ((ptr = strpbrk(in, "=&"))) {
191 if (*ptr == '&') { //No value specified
195 //Stopped at an '=' sign
198 if ((ptr = strchr(ptr,'&'))) {
204 } else { //No value specified and no other pair
212 * Aids in parsing request parameters.
213 * Input: The expected keys along with their type and whether or not
215 * @param context The context to work in
216 * @param params The parameter string to be parsed
217 * @param values An array of FCGIValue's that specify expected keys
218 * @param count The number of elements in 'values'.
219 * @return true If the parameter string was parsed successfully, false otherwise.
220 * Modes of failure include: Invalid a parsing error on the value,
221 * an unknown key is specified,
222 * a key/value pair is specified more than once, or
223 * not all required keys were present.
224 * If this function returns false, it is guaranteed that FCGI_RejectJSON
225 * has already been called with the appropriate description message.
227 bool FCGI_ParseRequest(FCGIContext *context, char *params, FCGIValue values[], size_t count)
229 const char *key, *value;
230 char buf[BUFSIZ], *ptr;
233 while ((params = FCGI_KeyPair(params, &key, &value))) {
234 for (i = 0; i < count; i++) {
235 if (!strcmp(key, values[i].key)) {
236 FCGIValue *val = &values[i];
238 if (FCGI_RECEIVED(val->flags)) {
239 snprintf(buf, BUFSIZ, "Value already specified for '%s'.", key);
240 FCGI_RejectJSON(context, buf);
243 val->flags |= FCGI_PARAM_RECEIVED;
245 switch(FCGI_TYPE(val->flags)) {
247 if (!*value) //No value: Default true
248 *((bool*) val->value) = true;
250 *((bool*) val->value) = !!(strtol(value, &ptr, 10));
252 snprintf(buf, BUFSIZ, "Expected bool for '%s' but got '%s'", key, value);
253 FCGI_RejectJSON(context, buf);
258 case FCGI_INT_T: case FCGI_LONG_T: {
259 long parsed = strtol(value, &ptr, 10);
260 if (!*value || *ptr) {
261 snprintf(buf, BUFSIZ, "Expected int for '%s' but got '%s'", key, value);
262 FCGI_RejectJSON(context, buf);
266 if (FCGI_TYPE(val->flags) == FCGI_INT_T)
267 *((int*) val->value) = (int) parsed;
269 *((long*) val->value) = parsed;
272 *((double*) val->value) = strtod(value, &ptr);
273 if (!*value || *ptr) {
274 snprintf(buf, BUFSIZ, "Expected float for '%s' but got '%s'", key, value);
275 FCGI_RejectJSON(context, buf);
280 *((const char**) val->value) = value;
283 Fatal("Invalid type %d given", FCGI_TYPE(val->flags));
285 break; //No need to search any more
289 snprintf(buf, BUFSIZ, "Unknown key '%s' specified", key);
290 FCGI_RejectJSON(context, buf);
295 //Check that required parameters are received
296 for (i = 0; i < count; i++) {
297 if (FCGI_IS_REQUIRED(values[i].flags) && !FCGI_RECEIVED(values[i].flags)) {
298 snprintf(buf, BUFSIZ, "Key '%s' required, but was not given.", values[i].key);
299 FCGI_RejectJSON(context, buf);
307 * Begins a response to the client in JSON format.
308 * @param context The context to work in.
309 * @param status_code The status code to be returned.
311 void FCGI_BeginJSON(FCGIContext *context, StatusCodes status_code)
313 printf("Content-type: application/json; charset=utf-8\r\n\r\n");
315 printf("\t\"module\" : \"%s\"", context->current_module);
316 FCGI_JSONLong("status", status_code);
317 //Time and running statistics
319 clock_gettime(CLOCK_MONOTONIC, &now);
320 FCGI_JSONDouble("start_time", TIMEVAL_TO_DOUBLE(g_options.start_time));
321 FCGI_JSONDouble("current_time", TIMEVAL_TO_DOUBLE(now));
322 FCGI_JSONDouble("running_time", TIMEVAL_DIFF(now, g_options.start_time));
323 FCGI_JSONPair("control_state", Control_GetModeName());
327 * Generic accept response in JSON format.
328 * @param context The context to work in
329 * @param description A short description.
330 * @param cookie Optional. If given, the cookie field is set to that value.
332 void FCGI_AcceptJSON(FCGIContext *context, const char *description, const char *cookie)
334 printf("Content-type: application/json; charset=utf-8\r\n");
336 printf("Set-Cookie: %s\r\n", cookie);
339 printf("\t\"module\" : \"%s\"", context->current_module);
340 FCGI_JSONLong("status", STATUS_OK);
341 FCGI_JSONPair("description", description);
346 * Adds a key/value pair to a JSON response. The response must have already
347 * been initiated by FCGI_BeginJSON. Special characters are not escaped.
348 * @param key The key of the JSON entry
349 * @param value The value associated with the key.
351 void FCGI_JSONPair(const char *key, const char *value)
353 printf(",\r\n\t\"%s\" : \"%s\"", key, value);
357 * Similar to FCGI_JSONPair except for signed integer values.
358 * @param key The key of the JSON entry
359 * @param value The value associated with the key
361 void FCGI_JSONLong(const char *key, long value)
363 printf(",\r\n\t\"%s\" : %ld", key, value);
367 * Similar to FCGI_JsonPair except for floating point values.
368 * @param key The key of the JSON entry
369 * @param value The value associated with the key
371 void FCGI_JSONDouble(const char *key, double value)
373 printf(",\r\n\t\"%s\" : %f", key, value);
377 * Similar to FCGI_JsonPair except for boolean values.
378 * @param key The key of the JSON entry
379 * @param value The value associated with the key
381 void FCGI_JSONBool(const char *key, bool value)
383 printf(",\r\n\t\"%s\" : %s", key, value ? "true" : "false");
387 * Begins a JSON entry by writing the key. To be used in conjunction
388 * with FCGI_JsonValue.
389 * @param key The key of the JSON entry
391 void FCGI_JSONKey(const char *key)
393 printf(",\r\n\t\"%s\" : ", key);
397 * Ends a JSON response that was initiated by FCGI_BeginJSON.
405 * To be used when the input parameters are rejected. The return data
406 * will also have debugging information provided.
407 * @param context The context to work in
408 * @param status The status the return data should have.
409 * @param description A short description of why the input was rejected.
411 void FCGI_RejectJSONEx(FCGIContext *context, StatusCodes status, const char *description)
413 if (description == NULL)
414 description = "Unknown";
416 Log(LOGINFO, "%s: Rejected query with: %d: %s", context->current_module, status, description);
417 FCGI_BeginJSON(context, status);
418 FCGI_JSONPair("description", description);
419 FCGI_JSONLong("responsenumber", context->response_number);
420 //FCGI_JSONPair("params", getenv("QUERY_STRING")); //A bad idea if contains password but also if contains unescaped stuff
421 FCGI_JSONPair("host", getenv("SERVER_HOSTNAME"));
422 FCGI_JSONPair("user", getenv("REMOTE_USER"));
423 FCGI_JSONPair("ip", getenv("REMOTE_ADDR"));
428 * Generates a response to the client as described by the format parameter and
429 * extra arguments (exactly like printf). To be used when none of the other
430 * predefined functions will work exactly as needed. Extra care should be taken
431 * to ensure the correctness of the output.
432 * @param format The format string
433 * @param ... Any extra arguments as required by the format string.
435 void FCGI_PrintRaw(const char *format, ...)
438 va_start(list, format);
439 vprintf(format, list);
448 void FCGI_WriteBinary(void * data, size_t size, size_t num_elem)
450 Log(LOGDEBUG,"Writing!");
451 fwrite(data, size, num_elem, stdout);
455 * Escapes a string so it can be used safely.
456 * Currently escapes to ensure the validity for use as a JSON string
457 * Does not support unicode specifiers in the form of \uXXXX.
458 * @param buf The string to be escaped
459 * @return The escaped string (return value == buf)
461 char *FCGI_EscapeText(char *buf)
464 length = strlen(buf);
466 //Escape special characters. Must count down to escape properly
467 for (i = length - 1; i >= 0; i--) {
468 if (buf[i] < 0x20) { //Control characters
470 } else if (buf[i] == '"') {
471 if (i-1 >= 0 && buf[i-1] == '\\')
475 } else if (buf[i] == '\\') {
476 if (i-1 >= 0 && buf[i-1] == '\'')
486 * Main FCGI request loop that receives/responds to client requests.
487 * @param data Reserved.
488 * @returns NULL (void* required for consistency with pthreads, although at the moment this runs in the main thread anyway)
489 * TODO: Get this to exit with the rest of the program!
491 void * FCGI_RequestLoop (void *data)
493 FCGIContext context = {0};
495 Log(LOGDEBUG, "Start loop");
496 while (FCGI_Accept() >= 0) {
498 ModuleHandler module_handler = NULL;
499 char module[BUFSIZ], params[BUFSIZ];
500 //Don't need to copy if we're not modifying string contents
501 const char *cookie = getenv("COOKIE_STRING");
503 //strncpy doesn't zero-truncate properly
504 snprintf(module, BUFSIZ, "%s", getenv("DOCUMENT_URI_LOCAL"));
505 snprintf(params, BUFSIZ, "%s", getenv("QUERY_STRING"));
507 Log(LOGDEBUG, "Got request #%d - Module %s, params %s", context.response_number, module, params);
508 Log(LOGDEBUG, "Cookie: %s", cookie);
511 //Remove trailing slashes (if present) from module query
512 size_t lastchar = strlen(module) - 1;
513 if (lastchar > 0 && module[lastchar] == '/')
514 module[lastchar] = 0;
516 //Default to the 'identify' module if none specified
518 strcpy(module, "identify");
520 if (!strcmp("identify", module)) {
521 module_handler = IdentifyHandler;
522 } else if (!strcmp("control", module)) {
523 module_handler = Control_Handler;
524 } else if (!strcmp("sensors", module)) {
525 module_handler = Sensor_Handler;
526 } else if (!strcmp("actuators", module)) {
527 module_handler = Actuator_Handler;
528 } else if (!strcmp("image", module)) {
529 module_handler = Image_Handler;
530 } else if (!strcmp("pin", module)) {
531 module_handler = Pin_Handler; // *Debug only* pin test module
532 } else if (!strcmp("bind", module)) {
533 module_handler = Login_Handler;
534 } else if (!strcmp("unbind", module)) {
535 module_handler = Logout_Handler;
538 context.current_module = module;
539 context.response_number++;
543 //if (module_handler != Login_Handler && module_handler != IdentifyHandler && module_handler)
544 if (false) // Testing
546 if (!FCGI_HasControl(&context, cookie))
548 FCGI_RejectJSON(&context, "Please login. Invalid control key.");
552 //Escape all special characters.
553 //Don't escape for login (password may have special chars?)
554 FCGI_EscapeText(params);
557 module_handler(&context, params);
561 FCGI_RejectJSON(&context, "Unhandled module");
565 Log(LOGDEBUG, "Thread exiting.");
566 // NOTE: Don't call pthread_exit, because this runs in the main thread. Just return.