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__);
49 FCGI_JSONLong("api_version", API_VERSION);
50 FCGI_JSONBool("logged_in", has_control);
51 FCGI_JSONPair("user_name", has_control ? context->user_name : "");
53 //Sensor and actuator information
55 FCGI_JSONKey("sensors");
56 FCGI_JSONValue("{\n\t\t");
57 for (i = 0; i < g_num_sensors; i++) {
59 FCGI_JSONValue(",\n\t\t");
61 FCGI_JSONValue("\"%d\" : \"%s\"", i, Sensor_GetName(i));
63 FCGI_JSONValue("\n\t}");
65 if (ident_actuators) {
66 FCGI_JSONKey("actuators");
67 FCGI_JSONValue("{\n\t\t");
68 for (i = 0; i < g_num_actuators; i++) {
70 FCGI_JSONValue(",\n\t\t");
72 FCGI_JSONValue("\"%d\" : \"%s\"", i, Actuator_GetName(i));
74 FCGI_JSONValue("\n\t}");
80 * Given an authorised user, attempt to set the control over the system.
81 * Modifies members in the context structure appropriately if successful.
82 * @param context The context to work in
83 * @param user_name - Name of the user
84 * @param user_type - Type of the user, passed after successful authentication
85 * @return true on success, false otherwise (eg someone else already in control)
87 bool FCGI_LockControl(FCGIContext *context, const char * user_name, UserType user_type)
90 time_t now = time(NULL);
91 bool expired = now - context->control_timestamp > CONTROL_TIMEOUT;
93 // Can't lock control if: User not actually logged in (sanity), or key is still valid and the user is not an admin
94 if (user_type == USER_UNAUTH ||
95 (user_type != USER_ADMIN && !expired && *(context->control_key) != '\0'))
98 // Release any existing control (if any)
99 FCGI_ReleaseControl(context);
102 context->control_timestamp = now;
104 // Generate a SHA1 hash for the user
106 unsigned char sha1[20];
109 SHA1_Update(&sha1ctx, &now, sizeof(now));
110 SHA1_Update(&sha1ctx, &i, sizeof(i));
111 SHA1_Final(sha1, &sha1ctx);
112 for (i = 0; i < sizeof(sha1); i++)
113 sprintf(context->control_key + i * 2, "%02x", sha1[i]);
115 // Set the IP address
116 snprintf(context->control_ip, 16, "%s", getenv("REMOTE_ADDR"));
118 int uname_len = strlen(user_name);
119 if (snprintf(context->user_name, sizeof(context->user_name), "%s", user_name) < uname_len)
121 Log(LOGERR, "Username at %d characters too long (limit %d)", uname_len, sizeof(context->user_name));
125 context->user_type = user_type;
127 if (mkdir(user_name, 0777) != 0 && errno != EEXIST)
129 Log(LOGERR, "Couldn't create user directory %s/%s - %s", g_options.root_dir, user_name, strerror(errno));
138 * Given an FCGIContext, determines if the current user (as specified by
139 * the key) has control or not. If validated, the context control_timestamp is
141 * @param context The context to work in
142 * @param key The control key to be validated.
143 * @return TRUE if authorized, FALSE if not.
145 bool FCGI_HasControl(FCGIContext *context, const char *key) {
146 time_t now = time(NULL);
147 int result = (now - context->control_timestamp) <= CONTROL_TIMEOUT &&
148 key != NULL && context->control_key[0] != '\0' &&
149 !strcmp(context->control_key, key);
151 context->control_timestamp = now; //Update the control_timestamp
158 * Revokes the current control key, if present.
159 * @param context The context to work in
161 void FCGI_ReleaseControl(FCGIContext *context) {
162 *(context->control_key) = 0;
163 // Note: context->user_name should *not* be cleared
168 * Extracts a key/value pair from a request string.
169 * Note that the input is modified by this function.
170 * @param in The string from which to extract the pair
171 * @param key A pointer to a variable to hold the key string
172 * @param value A pointer to a variable to hold the value string
173 * @return A pointer to the start of the next search location, or NULL if
174 * the EOL is reached.
176 char *FCGI_KeyPair(char *in, const char **key, const char **value)
179 if (!in || !*in) { //Invalid input or string is EOL
184 //Find either = or &, whichever comes first
185 if ((ptr = strpbrk(in, "=&"))) {
186 if (*ptr == '&') { //No value specified
190 //Stopped at an '=' sign
193 if ((ptr = strchr(ptr,'&'))) {
199 } else { //No value specified and no other pair
207 * Aids in parsing request parameters.
208 * Input: The expected keys along with their type and whether or not
210 * @param context The context to work in
211 * @param params The parameter string to be parsed
212 * @param values An array of FCGIValue's that specify expected keys
213 * @param count The number of elements in 'values'.
214 * @return true If the parameter string was parsed successfully, false otherwise.
215 * Modes of failure include: Invalid a parsing error on the value,
216 * an unknown key is specified,
217 * a key/value pair is specified more than once, or
218 * not all required keys were present.
219 * If this function returns false, it is guaranteed that FCGI_RejectJSON
220 * has already been called with the appropriate description message.
222 bool FCGI_ParseRequest(FCGIContext *context, char *params, FCGIValue values[], size_t count)
224 const char *key, *value;
225 char buf[BUFSIZ], *ptr;
228 while ((params = FCGI_KeyPair(params, &key, &value))) {
229 for (i = 0; i < count; i++) {
230 if (!strcmp(key, values[i].key)) {
231 FCGIValue *val = &values[i];
233 if (FCGI_RECEIVED(val->flags)) {
234 snprintf(buf, BUFSIZ, "Value already specified for '%s'.", key);
235 FCGI_RejectJSON(context, buf);
238 val->flags |= FCGI_PARAM_RECEIVED;
240 switch(FCGI_TYPE(val->flags)) {
242 if (!*value) //No value: Default true
243 *((bool*) val->value) = true;
245 *((bool*) val->value) = !!(strtol(value, &ptr, 10));
247 snprintf(buf, BUFSIZ, "Expected bool for '%s' but got '%s'", key, value);
248 FCGI_RejectJSON(context, buf);
253 case FCGI_INT_T: case FCGI_LONG_T: {
254 long parsed = strtol(value, &ptr, 10);
255 if (!*value || *ptr) {
256 snprintf(buf, BUFSIZ, "Expected int for '%s' but got '%s'", key, value);
257 FCGI_RejectJSON(context, buf);
261 if (FCGI_TYPE(val->flags) == FCGI_INT_T)
262 *((int*) val->value) = (int) parsed;
264 *((long*) val->value) = parsed;
267 *((double*) val->value) = strtod(value, &ptr);
268 if (!*value || *ptr) {
269 snprintf(buf, BUFSIZ, "Expected float for '%s' but got '%s'", key, value);
270 FCGI_RejectJSON(context, buf);
275 *((const char**) val->value) = value;
278 Fatal("Invalid type %d given", FCGI_TYPE(val->flags));
280 break; //No need to search any more
284 snprintf(buf, BUFSIZ, "Unknown key '%s' specified", key);
285 FCGI_RejectJSON(context, buf);
290 //Check that required parameters are received
291 for (i = 0; i < count; i++) {
292 if (FCGI_IS_REQUIRED(values[i].flags) && !FCGI_RECEIVED(values[i].flags)) {
293 snprintf(buf, BUFSIZ, "Key '%s' required, but was not given.", values[i].key);
294 FCGI_RejectJSON(context, buf);
302 * Begins a response to the client in JSON format.
303 * @param context The context to work in.
304 * @param status_code The status code to be returned.
306 void FCGI_BeginJSON(FCGIContext *context, StatusCodes status_code)
308 printf("Content-type: application/json; charset=utf-8\r\n\r\n");
310 printf("\t\"module\" : \"%s\"", context->current_module);
311 FCGI_JSONLong("status", status_code);
312 //Time and running statistics
314 gettimeofday(&now, NULL);
315 FCGI_JSONDouble("start_time", TIMEVAL_TO_DOUBLE(g_options.start_time));
316 FCGI_JSONDouble("current_time", TIMEVAL_TO_DOUBLE(now));
317 FCGI_JSONDouble("running_time", TIMEVAL_DIFF(now, g_options.start_time));
318 FCGI_JSONPair("control_state", Control_GetModeName());
322 * Generic accept response in JSON format.
323 * @param context The context to work in
324 * @param description A short description.
325 * @param cookie Optional. If given, the cookie field is set to that value.
327 void FCGI_AcceptJSON(FCGIContext *context, const char *description, const char *cookie)
329 printf("Content-type: application/json; charset=utf-8\r\n");
331 printf("Set-Cookie: %s\r\n", cookie);
334 printf("\t\"module\" : \"%s\"", context->current_module);
335 FCGI_JSONLong("status", STATUS_OK);
336 FCGI_JSONPair("description", description);
341 * Adds a key/value pair to a JSON response. The response must have already
342 * been initiated by FCGI_BeginJSON. Special characters are not escaped.
343 * @param key The key of the JSON entry
344 * @param value The value associated with the key.
346 void FCGI_JSONPair(const char *key, const char *value)
348 printf(",\r\n\t\"%s\" : \"%s\"", key, value);
352 * Similar to FCGI_JSONPair except for signed integer values.
353 * @param key The key of the JSON entry
354 * @param value The value associated with the key
356 void FCGI_JSONLong(const char *key, long value)
358 printf(",\r\n\t\"%s\" : %ld", key, value);
362 * Similar to FCGI_JsonPair except for floating point values.
363 * @param key The key of the JSON entry
364 * @param value The value associated with the key
366 void FCGI_JSONDouble(const char *key, double value)
368 printf(",\r\n\t\"%s\" : %f", key, value);
372 * Similar to FCGI_JsonPair except for boolean values.
373 * @param key The key of the JSON entry
374 * @param value The value associated with the key
376 void FCGI_JSONBool(const char *key, bool value)
378 printf(",\r\n\t\"%s\" : %s", key, value ? "true" : "false");
382 * Begins a JSON entry by writing the key. To be used in conjunction
383 * with FCGI_JsonValue.
384 * @param key The key of the JSON entry
386 void FCGI_JSONKey(const char *key)
388 printf(",\r\n\t\"%s\" : ", key);
392 * Ends a JSON response that was initiated by FCGI_BeginJSON.
400 * To be used when the input parameters are rejected. The return data
401 * will also have debugging information provided.
402 * @param context The context to work in
403 * @param status The status the return data should have.
404 * @param description A short description of why the input was rejected.
406 void FCGI_RejectJSONEx(FCGIContext *context, StatusCodes status, const char *description)
408 if (description == NULL)
409 description = "Unknown";
411 Log(LOGINFO, "%s: Rejected query with: %d: %s", context->current_module, status, description);
412 FCGI_BeginJSON(context, status);
413 FCGI_JSONPair("description", description);
414 FCGI_JSONLong("responsenumber", context->response_number);
415 //FCGI_JSONPair("params", getenv("QUERY_STRING")); //A bad idea if contains password but also if contains unescaped stuff
416 FCGI_JSONPair("host", getenv("SERVER_HOSTNAME"));
417 FCGI_JSONPair("user", getenv("REMOTE_USER"));
418 FCGI_JSONPair("ip", getenv("REMOTE_ADDR"));
423 * Generates a response to the client as described by the format parameter and
424 * extra arguments (exactly like printf). To be used when none of the other
425 * predefined functions will work exactly as needed. Extra care should be taken
426 * to ensure the correctness of the output.
427 * @param format The format string
428 * @param ... Any extra arguments as required by the format string.
430 void FCGI_PrintRaw(const char *format, ...)
433 va_start(list, format);
434 vprintf(format, list);
443 void FCGI_WriteBinary(void * data, size_t size, size_t num_elem)
445 Log(LOGDEBUG,"Writing!");
446 fwrite(data, size, num_elem, stdout);
450 * Escapes a string so it can be used safely.
451 * Currently escapes to ensure the validity for use as a JSON string
452 * Does not support unicode specifiers in the form of \uXXXX.
453 * @param buf The string to be escaped
454 * @return The escaped string (return value == buf)
456 char *FCGI_EscapeText(char *buf)
459 length = strlen(buf);
461 //Escape special characters. Must count down to escape properly
462 for (i = length - 1; i >= 0; i--) {
463 if (buf[i] < 0x20) { //Control characters
465 } else if (buf[i] == '"') {
466 if (i-1 >= 0 && buf[i-1] == '\\')
470 } else if (buf[i] == '\\') {
471 if (i-1 >= 0 && buf[i-1] == '\'')
481 * Main FCGI request loop that receives/responds to client requests.
482 * @param data Reserved.
483 * @returns NULL (void* required for consistency with pthreads, although at the moment this runs in the main thread anyway)
484 * TODO: Get this to exit with the rest of the program!
486 void * FCGI_RequestLoop (void *data)
488 FCGIContext context = {0};
490 Log(LOGDEBUG, "Start loop");
491 while (FCGI_Accept() >= 0) {
493 ModuleHandler module_handler = NULL;
494 char module[BUFSIZ], params[BUFSIZ];
495 //Don't need to copy if we're not modifying string contents
496 const char *cookie = getenv("COOKIE_STRING");
498 //strncpy doesn't zero-truncate properly
499 snprintf(module, BUFSIZ, "%s", getenv("DOCUMENT_URI_LOCAL"));
500 snprintf(params, BUFSIZ, "%s", getenv("QUERY_STRING"));
502 Log(LOGDEBUG, "Got request #%d - Module %s, params %s", context.response_number, module, params);
503 Log(LOGDEBUG, "Cookie: %s", cookie);
506 //Remove trailing slashes (if present) from module query
507 size_t lastchar = strlen(module) - 1;
508 if (lastchar > 0 && module[lastchar] == '/')
509 module[lastchar] = 0;
511 //Default to the 'identify' module if none specified
513 strcpy(module, "identify");
515 if (!strcmp("identify", module)) {
516 module_handler = IdentifyHandler;
517 } else if (!strcmp("control", module)) {
518 module_handler = Control_Handler;
519 } else if (!strcmp("sensors", module)) {
520 module_handler = Sensor_Handler;
521 } else if (!strcmp("actuators", module)) {
522 module_handler = Actuator_Handler;
523 } else if (!strcmp("image", module)) {
524 module_handler = Image_Handler;
525 } else if (!strcmp("pin", module)) {
526 module_handler = Pin_Handler; // *Debug only* pin test module
527 } else if (!strcmp("bind", module)) {
528 module_handler = Login_Handler;
529 } else if (!strcmp("unbind", module)) {
530 module_handler = Logout_Handler;
533 context.current_module = module;
534 context.response_number++;
538 if (module_handler != Login_Handler && module_handler != IdentifyHandler && module_handler)
539 //if (false) // Testing
541 if (!FCGI_HasControl(&context, cookie))
543 FCGI_RejectJSON(&context, "Please login. Invalid control key.");
547 //Escape all special characters.
548 //Don't escape for login (password may have special chars?)
549 FCGI_EscapeText(params);
552 module_handler(&context, params);
556 FCGI_RejectJSON(&context, "Unhandled module");
560 Log(LOGDEBUG, "Thread exiting.");
561 // NOTE: Don't call pthread_exit, because this runs in the main thread. Just return.