3 * @purpose 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>
18 #define LOGIN_TIMEOUT 180
21 /**The time of last valid logged-in user access*/
22 time_t login_timestamp;
25 /**The name of the current module**/
26 const char *current_module;
27 /**For debugging purposes?**/
32 * Handles user logins.
33 * @param context The context to work in
34 * @param params User specified parameters
36 static void LoginHandler(FCGIContext *context, char *params) {
37 const char *key, *value;
38 bool force = 0, end = 0;
40 while ((params = FCGI_KeyPair(params, &key, &value))) {
41 if (!strcmp(key, "force"))
43 else if (!strcmp(key, "end"))
48 *(context->login_key) = 0;
49 FCGI_BeginJSON(context, STATUS_OK);
54 time_t now = time(NULL);
55 if (force || !*(context->login_key) ||
56 (now - context->login_timestamp > LOGIN_TIMEOUT))
59 unsigned char sha1[20];
63 SHA1_Update(&sha1ctx, &now, sizeof(now));
64 SHA1_Update(&sha1ctx, &i, sizeof(i));
65 SHA1_Final(sha1, &sha1ctx);
67 context->login_timestamp = now;
68 for (i = 0; i < 20; i++)
69 sprintf(context->login_key + i * 2, "%02x", sha1[i]);
70 snprintf(context->login_ip, 16, "%s", getenv("REMOTE_ADDR"));
71 FCGI_BeginJSON(context, STATUS_OK);
72 FCGI_JSONPair("key", context->login_key);
76 strftime(buf, 128, "%H:%M:%S %d-%m-%Y",
77 localtime(&(context->login_timestamp)));
78 FCGI_BeginJSON(context, STATUS_UNAUTHORIZED);
79 FCGI_JSONPair("description", "Already logged in");
80 FCGI_JSONPair("user", context->login_ip);
81 FCGI_JSONPair("time", buf);
87 * Given an FCGIContext, determines if the current user (as specified by
88 * the key) is authorized or not. If validated, the context login_timestamp is
90 * @param context The context to work in
91 * @param key The login key to be validated.
92 * @return TRUE if authorized, FALSE if not.
94 bool FCGI_Authorized(FCGIContext *context, const char *key) {
95 time_t now = time(NULL);
96 int result = (now - context->login_timestamp) <= LOGIN_TIMEOUT &&
97 !strcmp(context->login_key, key);
99 context->login_timestamp = now; //Update the login_timestamp
105 * Extracts a key/value pair from a request string.
106 * Note that the input is modified by this function.
107 * @param in The string from which to extract the pair
108 * @param key A pointer to a variable to hold the key string
109 * @param value A pointer to a variable to hold the value string
110 * @return A pointer to the start of the next search location, or NULL if
111 * the EOL is reached.
113 char *FCGI_KeyPair(char *in, const char **key, const char **value)
116 if (!in || !*in) { //Invalid input or string is EOL
121 //Find either = or &, whichever comes first
122 if ((ptr = strpbrk(in, "=&"))) {
123 if (*ptr == '&') { //No value specified
127 //Stopped at an '=' sign
130 if ((ptr = strchr(ptr,'&'))) {
136 } else { //No value specified and no other pair
144 * Begins a response to the client in JSON format.
145 * @param context The context to work in.
146 * @param status_code The status code to be returned.
148 void FCGI_BeginJSON(FCGIContext *context, StatusCodes status_code)
150 printf("Content-type: application/json; charset=utf-8\r\n\r\n");
152 printf("\t\"module\" : \"%s\"", context->current_module);
153 FCGI_JSONLong("status", status_code);
157 * Adds a key/value pair to a JSON response. The response must have already
158 * been initiated by FCGI_BeginJSON. Note that characters are not escaped.
159 * @param key The key of the JSON entry
160 * ¶m value The value associated with the key.
162 void FCGI_JSONPair(const char *key, const char *value)
164 printf(",\r\n\t\"%s\" : \"%s\"", key, value);
168 * Similar to FCGI_JSONPair except for signed integer values.
169 * @param key The key of the JSON entry
170 * @param value The value associated with the key
172 void FCGI_JSONLong(const char *key, long value)
174 printf(",\r\n\t\"%s\" : %ld", key, value);
178 * Similar to FCGI_JsonPair except for floating point values.
179 * @param key The key of the JSON entry
180 * @param value The value associated with the key
182 void FCGI_JSONDouble(const char *key, double value)
184 printf(",\r\n\t\"%s\" : %f", key, value);
188 * Begins a JSON entry by writing the key. To be used in conjunction
189 * with FCGI_JsonValue.
190 * @param key The key of the JSON entry
192 void FCGI_JSONKey(const char *key)
194 printf(",\r\n\t\"%s\" : ", key);
198 * Should be used to write out the value of a JSON key. This has
199 * the same format as the printf functions. Care should be taken to format
200 * the output in valid JSON.
202 void FCGI_JSONValue(const char *format, ...)
205 va_start(list, format);
206 vprintf(format, list);
211 * Ends a JSON response that was initiated by FCGI_BeginJSON.
219 * To be used when the input parameters are invalid.
220 * Sends a response with HTTP status 400 Bad request, along with
221 * JSON data for debugging.
222 * @param context The context to work in
223 * @param params The parameters that the module handler received.
225 void FCGI_RejectJSON(FCGIContext *context)
227 printf("Status: 400 Bad Request\r\n");
229 FCGI_BeginJSON(context, STATUS_ERROR);
230 FCGI_JSONPair("description", "Invalid request");
231 FCGI_JSONLong("responsenumber", context->response_number);
232 FCGI_JSONPair("params", getenv("DOCUMENT_URI_LOCAL"));
233 FCGI_JSONPair("host", getenv("SERVER_HOSTNAME"));
234 FCGI_JSONPair("user", getenv("REMOTE_USER"));
235 FCGI_JSONPair("ip", getenv("REMOTE_ADDR"));
240 * Main FCGI request loop that receives/responds to client requests.
241 * @param data Reserved.
243 void FCGI_RequestLoop (void *data)
245 FCGIContext context = {0};
247 while (FCGI_Accept() >= 0) {
248 ModuleHandler module_handler = NULL;
249 char module[BUFSIZ], params[BUFSIZ];
251 //strncpy doesn't zero-truncate properly
252 snprintf(module, BUFSIZ, "%s", getenv("DOCUMENT_URI_LOCAL"));
253 snprintf(params, BUFSIZ, "%s", getenv("QUERY_STRING"));
255 //Remove trailing slashes (if present) from module query
256 size_t lastchar = strlen(module) - 1;
257 if (lastchar > 0 && module[lastchar] == '/')
258 module[lastchar] = 0;
261 if (!strcmp("login", module)) {
262 module_handler = LoginHandler;
263 } else if (!strcmp("sensors", module)) {
264 module_handler = Sensor_Handler;
265 } else if (!strcmp("actuators", module)) {
269 context.current_module = module;
270 if (module_handler) {
271 module_handler(&context, params);
273 strncat(module, " [unknown]", BUFSIZ);
274 FCGI_RejectJSON(&context);
277 context.response_number++;