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 char control_key[CONTROL_KEY_BUFSIZ];
42 snprintf(control_key, CONTROL_KEY_BUFSIZ, "%s", getenv("COOKIE_STRING"));
43 has_control = FCGI_HasControl(context, control_key);
45 FCGIValue values[2] = {{"sensors", &ident_sensors, FCGI_BOOL_T},
46 {"actuators", &ident_actuators, FCGI_BOOL_T}};
47 if (!FCGI_ParseRequest(context, params, values, 2))
50 FCGI_BeginJSON(context, STATUS_OK);
51 FCGI_JSONPair("description", "MCTX3420 Server API (2013)");
52 FCGI_JSONPair("build_date", __DATE__ " " __TIME__);
54 t.tv_sec = 0; t.tv_nsec = 0;
55 clock_getres(CLOCK_MONOTONIC, &t);
56 FCGI_JSONDouble("clock_getres", TIMEVAL_TO_DOUBLE(t));
57 FCGI_JSONLong("api_version", API_VERSION);
58 FCGI_JSONBool("logged_in", has_control);
59 FCGI_JSONPair("user_name", has_control ? context->user_name : "");
62 //Sensor and actuator information
64 FCGI_JSONKey("sensors");
65 FCGI_JSONValue("{\n\t\t");
66 for (i = 0; i < g_num_sensors; i++) {
68 FCGI_JSONValue(",\n\t\t");
70 FCGI_JSONValue("\"%d\" : \"%s\"", i, Sensor_GetName(i));
72 FCGI_JSONValue("\n\t}");
74 if (ident_actuators) {
75 FCGI_JSONKey("actuators");
76 FCGI_JSONValue("{\n\t\t");
77 for (i = 0; i < g_num_actuators; i++) {
79 FCGI_JSONValue(",\n\t\t");
81 FCGI_JSONValue("\"%d\" : \"%s\"", i, Actuator_GetName(i));
83 FCGI_JSONValue("\n\t}");
89 * Given an authorised user, attempt to set the control over the system.
90 * Modifies members in the context structure appropriately if successful.
91 * @param context The context to work in
92 * @param user_name - Name of the user
93 * @param user_type - Type of the user, passed after successful authentication
94 * @return true on success, false otherwise (eg someone else already in control)
96 bool FCGI_LockControl(FCGIContext *context, const char * user_name, UserType user_type)
99 time_t now = time(NULL);
100 bool expired = now - context->control_timestamp > CONTROL_TIMEOUT;
103 // Can't lock control if: User not actually logged in (sanity), or key is still valid and the user is not an admin
104 if (user_type == USER_UNAUTH ||
105 (user_type != USER_ADMIN && !expired && *(context->control_key) != '\0'))
108 // Release any existing control (if any)
109 FCGI_ReleaseControl(context);
112 context->control_timestamp = now;
114 // Generate a SHA1 hash for the user
116 unsigned char sha1[20];
119 SHA1_Update(&sha1ctx, &now, sizeof(now));
120 SHA1_Update(&sha1ctx, &i, sizeof(i));
121 SHA1_Final(sha1, &sha1ctx);
122 for (i = 0; i < sizeof(sha1); i++)
123 sprintf(context->control_key + i * 2, "%02x", sha1[i]);
125 // Set the IPv4 address
126 snprintf(context->control_ip, 16, "%s", getenv("REMOTE_ADDR"));
129 int uname_len = strlen(user_name);
130 i = snprintf(context->user_name, sizeof(context->user_name), "%s", user_name);
132 Log(LOGERR, "Username at %d characters too long (limit %d)",
133 uname_len, sizeof(context->user_name));
137 context->user_type = user_type;
139 // Build the user directory
140 i = snprintf(context->user_dir, sizeof(context->user_dir), "%s/%s",
141 g_options.experiment_dir, context->user_name);
142 if (i >= sizeof(context->user_dir)) {
143 Log(LOGERR, "Experiment dir too long (required %d, limit %d)",
144 i, sizeof(context->user_dir));
148 Log(LOGDEBUG, "User dir: %s", context->user_dir);
150 if (mkdir(context->user_dir, 0777) != 0 && errno != EEXIST)
152 Log(LOGERR, "Couldn't create user directory %s - %s",
153 context->user_dir, strerror(errno));
161 * Given an FCGIContext, determines if the current user (as specified by
162 * the key) has control or not. If validated, the context control_timestamp is
164 * @param context The context to work in
165 * @param key The control key to be validated.
166 * @return TRUE if authorized, FALSE if not.
168 bool FCGI_HasControl(FCGIContext *context, const char *key) {
169 time_t now = time(NULL);
170 int result = (now - context->control_timestamp) <= CONTROL_TIMEOUT &&
171 key != NULL && context->control_key[0] != '\0' &&
172 !strcmp(context->control_key, key);
174 context->control_timestamp = now; //Update the control_timestamp
181 * Revokes the current control key, if present.
182 * @param context The context to work in
184 void FCGI_ReleaseControl(FCGIContext *context) {
185 *(context->control_key) = 0;
186 // Note: context->user_name should *not* be cleared
191 * Extracts a key/value pair from a request string.
192 * Note that the input is modified by this function.
193 * @param in The string from which to extract the pair
194 * @param key A pointer to a variable to hold the key string
195 * @param value A pointer to a variable to hold the value string
196 * @return A pointer to the start of the next search location, or NULL if
197 * the EOL is reached.
199 char *FCGI_KeyPair(char *in, const char **key, const char **value)
202 if (!in || !*in) { //Invalid input or string is EOL
207 //Find either = or &, whichever comes first
208 if ((ptr = strpbrk(in, "=&"))) {
209 if (*ptr == '&') { //No value specified
213 //Stopped at an '=' sign
216 if ((ptr = strchr(ptr,'&'))) {
222 } else { //No value specified and no other pair
230 * Aids in parsing request parameters.
231 * Input: The expected keys along with their type and whether or not
233 * @param context The context to work in
234 * @param params The parameter string to be parsed
235 * @param values An array of FCGIValue's that specify expected keys
236 * @param count The number of elements in 'values'.
237 * @return true If the parameter string was parsed successfully, false otherwise.
238 * Modes of failure include: Invalid a parsing error on the value,
239 * an unknown key is specified,
240 * a key/value pair is specified more than once, or
241 * not all required keys were present.
242 * If this function returns false, it is guaranteed that FCGI_RejectJSON
243 * has already been called with the appropriate description message.
245 bool FCGI_ParseRequest(FCGIContext *context, char *params, FCGIValue values[], size_t count)
247 const char *key, *value;
248 char buf[BUFSIZ], *ptr;
251 while ((params = FCGI_KeyPair(params, &key, &value))) {
252 for (i = 0; i < count; i++) {
253 if (!strcmp(key, values[i].key)) {
254 FCGIValue *val = &values[i];
256 if (FCGI_RECEIVED(val->flags)) {
257 snprintf(buf, BUFSIZ, "Value already specified for '%s'.", key);
258 FCGI_RejectJSON(context, buf);
261 val->flags |= FCGI_PARAM_RECEIVED;
263 switch(FCGI_TYPE(val->flags)) {
265 if (!*value) //No value: Default true
266 *((bool*) val->value) = true;
268 *((bool*) val->value) = !!(strtol(value, &ptr, 10));
270 snprintf(buf, BUFSIZ, "Expected bool for '%s' but got '%s'", key, value);
271 FCGI_RejectJSON(context, buf);
276 case FCGI_INT_T: case FCGI_LONG_T: {
277 long parsed = strtol(value, &ptr, 10);
278 if (!*value || *ptr) {
279 snprintf(buf, BUFSIZ, "Expected int for '%s' but got '%s'", key, value);
280 FCGI_RejectJSON(context, buf);
284 if (FCGI_TYPE(val->flags) == FCGI_INT_T)
285 *((int*) val->value) = (int) parsed;
287 *((long*) val->value) = parsed;
290 *((double*) val->value) = strtod(value, &ptr);
291 if (!*value || *ptr) {
292 snprintf(buf, BUFSIZ, "Expected float for '%s' but got '%s'", key, value);
293 FCGI_RejectJSON(context, buf);
298 *((const char**) val->value) = value;
301 Fatal("Invalid type %d given", FCGI_TYPE(val->flags));
303 break; //No need to search any more
307 snprintf(buf, BUFSIZ, "Unknown key '%s' specified", key);
308 FCGI_RejectJSON(context, buf);
313 //Check that required parameters are received
314 for (i = 0; i < count; i++) {
315 if (FCGI_IS_REQUIRED(values[i].flags) && !FCGI_RECEIVED(values[i].flags)) {
316 snprintf(buf, BUFSIZ, "Key '%s' required, but was not given.", values[i].key);
317 FCGI_RejectJSON(context, buf);
325 * Begins a response to the client in JSON format.
326 * @param context The context to work in.
327 * @param status_code The status code to be returned.
329 void FCGI_BeginJSON(FCGIContext *context, StatusCodes status_code)
331 printf("Content-type: application/json; charset=utf-8\r\n\r\n");
333 printf("\t\"module\" : \"%s\"", context->current_module);
334 FCGI_JSONLong("status", status_code);
335 //Time and running statistics
337 clock_gettime(CLOCK_MONOTONIC, &now);
338 FCGI_JSONDouble("start_time", TIMEVAL_TO_DOUBLE(g_options.start_time));
339 FCGI_JSONDouble("current_time", TIMEVAL_TO_DOUBLE(now));
340 FCGI_JSONDouble("running_time", TIMEVAL_DIFF(now, g_options.start_time));
341 FCGI_JSONPair("control_state", Control_GetModeName());
345 * Generic accept response in JSON format.
346 * @param context The context to work in
347 * @param description A short description.
348 * @param cookie Optional. If given, the cookie field is set to that value.
350 void FCGI_AcceptJSON(FCGIContext *context, const char *description, const char *cookie)
352 printf("Content-type: application/json; charset=utf-8\r\n");
354 printf("Set-Cookie: %s\r\n", cookie);
357 printf("\t\"module\" : \"%s\"", context->current_module);
358 FCGI_JSONLong("status", STATUS_OK);
359 FCGI_JSONPair("description", description);
364 * Adds a key/value pair to a JSON response. The response must have already
365 * been initiated by FCGI_BeginJSON. Special characters are not escaped.
366 * @param key The key of the JSON entry
367 * @param value The value associated with the key.
369 void FCGI_JSONPair(const char *key, const char *value)
371 printf(",\r\n\t\"%s\" : \"%s\"", key, value);
375 * Similar to FCGI_JSONPair except for signed integer values.
376 * @param key The key of the JSON entry
377 * @param value The value associated with the key
379 void FCGI_JSONLong(const char *key, long value)
381 printf(",\r\n\t\"%s\" : %ld", key, value);
385 * Similar to FCGI_JsonPair except for floating point values.
386 * @param key The key of the JSON entry
387 * @param value The value associated with the key
389 void FCGI_JSONDouble(const char *key, double value)
391 printf(",\r\n\t\"%s\" : %.9f", key, value);
395 * Similar to FCGI_JsonPair except for boolean values.
396 * @param key The key of the JSON entry
397 * @param value The value associated with the key
399 void FCGI_JSONBool(const char *key, bool value)
401 printf(",\r\n\t\"%s\" : %s", key, value ? "true" : "false");
405 * Begins a JSON entry by writing the key. To be used in conjunction
406 * with FCGI_JsonValue.
407 * @param key The key of the JSON entry
409 void FCGI_JSONKey(const char *key)
411 printf(",\r\n\t\"%s\" : ", key);
415 * Ends a JSON response that was initiated by FCGI_BeginJSON.
423 * To be used when the input parameters are rejected. The return data
424 * will also have debugging information provided.
425 * @param context The context to work in
426 * @param status The status the return data should have.
427 * @param description A short description of why the input was rejected.
429 void FCGI_RejectJSONEx(FCGIContext *context, StatusCodes status, const char *description)
431 if (description == NULL)
432 description = "Unknown";
434 Log(LOGINFO, "%s: Rejected query with: %d: %s", context->current_module, status, description);
435 FCGI_BeginJSON(context, status);
436 FCGI_JSONPair("description", description);
437 FCGI_JSONLong("responsenumber", context->response_number);
438 //FCGI_JSONPair("params", getenv("QUERY_STRING")); //A bad idea if contains password but also if contains unescaped stuff
439 FCGI_JSONPair("host", getenv("SERVER_HOSTNAME"));
440 FCGI_JSONPair("user", getenv("REMOTE_USER"));
441 FCGI_JSONPair("ip", getenv("REMOTE_ADDR"));
446 * Generates a response to the client as described by the format parameter and
447 * extra arguments (exactly like printf). To be used when none of the other
448 * predefined functions will work exactly as needed. Extra care should be taken
449 * to ensure the correctness of the output.
450 * @param format The format string
451 * @param ... Any extra arguments as required by the format string.
453 void FCGI_PrintRaw(const char *format, ...)
456 va_start(list, format);
457 vprintf(format, list);
466 void FCGI_WriteBinary(void * data, size_t size, size_t num_elem)
468 Log(LOGDEBUG,"Writing!");
469 fwrite(data, size, num_elem, stdout);
473 * Escapes a string so it can be used safely.
474 * Currently escapes to ensure the validity for use as a JSON string
475 * Does not support unicode specifiers in the form of \uXXXX.
476 * @param buf The string to be escaped
477 * @return The escaped string (return value == buf)
479 char *FCGI_EscapeText(char *buf)
482 length = strlen(buf);
484 //Escape special characters. Must count down to escape properly
485 for (i = length - 1; i >= 0; i--) {
486 if (buf[i] < 0x20) { //Control characters
488 } else if (buf[i] == '"') {
489 if (i-1 >= 0 && buf[i-1] == '\\')
493 } else if (buf[i] == '\\') {
494 if (i-1 >= 0 && buf[i-1] == '\'')
504 * Main FCGI request loop that receives/responds to client requests.
505 * @param data Reserved.
506 * @returns NULL (void* required for consistency with pthreads, although at the moment this runs in the main thread anyway)
507 * TODO: Get this to exit with the rest of the program!
509 void * FCGI_RequestLoop (void *data)
511 FCGIContext context = {0};
513 Log(LOGDEBUG, "Start loop");
514 while (FCGI_Accept() >= 0) {
516 ModuleHandler module_handler = NULL;
517 char module[BUFSIZ], params[BUFSIZ], control_key[CONTROL_KEY_BUFSIZ];
519 //strncpy doesn't zero-truncate properly
520 snprintf(module, BUFSIZ, "%s", getenv("DOCUMENT_URI_LOCAL"));
521 snprintf(params, BUFSIZ, "%s", getenv("QUERY_STRING"));
523 //Hack to get the nameless cookie only
524 snprintf(control_key, CONTROL_KEY_BUFSIZ, "%s", getenv("COOKIE_STRING"));
526 Log(LOGDEBUG, "Got request #%d - Module %s, params %s", context.response_number, module, params);
527 Log(LOGDEBUG, "Control key: %s", control_key);
530 //Remove trailing slashes (if present) from module query
531 size_t lastchar = strlen(module) - 1;
532 if (lastchar > 0 && module[lastchar] == '/')
533 module[lastchar] = 0;
535 //Default to the 'identify' module if none specified
537 strcpy(module, "identify");
539 if (!strcmp("identify", module)) {
540 module_handler = IdentifyHandler;
541 } else if (!strcmp("control", module)) {
542 module_handler = Control_Handler;
543 } else if (!strcmp("sensors", module)) {
544 module_handler = Sensor_Handler;
545 } else if (!strcmp("actuators", module)) {
546 module_handler = Actuator_Handler;
547 } else if (!strcmp("image", module)) {
548 module_handler = Image_Handler;
549 } else if (!strcmp("pin", module)) {
550 module_handler = Pin_Handler; // *Debug only* pin test module
551 } else if (!strcmp("bind", module)) {
552 module_handler = Login_Handler;
553 } else if (!strcmp("unbind", module)) {
554 module_handler = Logout_Handler;
557 context.current_module = module;
558 context.response_number++;
562 //if (module_handler != Login_Handler && module_handler != IdentifyHandler && module_handler)
563 if (false) // Testing
565 if (!FCGI_HasControl(&context, control_key))
567 FCGI_RejectJSON(&context, "Please login. Invalid control key.");
571 //Escape all special characters.
572 //Don't escape for login (password may have special chars?)
573 FCGI_EscapeText(params);
576 module_handler(&context, params);
580 FCGI_RejectJSON(&context, "Unhandled module");
584 Log(LOGDEBUG, "Thread exiting.");
585 // NOTE: Don't call pthread_exit, because this runs in the main thread. Just return.