add option of saving pid file

src/commandline.c

@@ -72,6 +72,7 @@ usage(void)
             "  -x pid        Used internally by WiFiDog when re-starting itself *DO NOT ISSUE THIS SWITCH MANUAlLY*\n");
     fprintf(stdout, "  -i <path>     Internal socket path used when re-starting self\n");
     fprintf(stdout, "  -a <path>     Path to /proc/net/arp replacement - mainly useful for debugging.\n");
+    fprintf(stdout, "  -p <path>     Save pid to file\n");
     fprintf(stdout, "\n");
 }
 
@@ -164,6 +165,15 @@ parse_commandline(int argc, char **argv)
                 exit(1);
             }
             break;
+        case 'p':
+            if (optarg) {
+                free(config->pidfile);
+                config->pidfile = safe_strdup(optarg);
+            } else {
+                fprintf(stdout, "The expected PID file path to the wifidog was not supplied!\n");
+                exit(1);
+            }
+            break;
         default:
             usage();
             exit(1);

src/conf.c

@@ -193,6 +193,7 @@ config_init(void)
     config.clienttimeout = DEFAULT_CLIENTTIMEOUT;
     config.checkinterval = DEFAULT_CHECKINTERVAL;
     config.daemon = -1;
+    config.pidfile = NULL;
     config.wdctl_sock = safe_strdup(DEFAULT_WDCTL_SOCK);
     config.internal_sock = safe_strdup(DEFAULT_INTERNAL_SOCK);
     config.rulesets = NULL;

src/conf.h

@@ -162,6 +162,7 @@ typedef struct {
     char *internal_sock;                /**< @brief internal path to socket */
     int deltatraffic;                   /**< @brief reset each user's traffic (Outgoing and Incoming) value after each Auth operation. */
     int daemon;                 /**< @brief if daemon > 0, use daemon mode */
+    char *pidfile;            /**< @brief pid file path of wifidog */
     char *external_interface;   /**< @brief External network interface name for
 				     firewall rules */
     char *gw_id;                /**< @brief ID of the Gateway, sent to central

src/gateway.c

@@ -366,6 +366,10 @@ main_loop(void)
         started_time = time(NULL);
     }
 
+	/* save the pid file if needed */
+    if ((!config) && (!config->pidfile))
+        save_pid_file(config->pidfile);
+
     /* If we don't have the Gateway IP address, get it. Can't fail. */
     if (!config->gw_address) {
         debug(LOG_DEBUG, "Finding IP address of %s", config->gw_interface);

src/util.c

@@ -389,3 +389,25 @@ rand16(void)
      * ignore that one. */
     return ((unsigned short)(rand() >> 15));
 }
+
+/*
+ * Save pid of this wifidog in pid file
+ * @param 'pf' as string, it is the pid file absolutely path
+ */
+void
+save_pid_file(const char *pf)
+{
+    if (pf) {
+        FILE *f = fopen(pf, "w");
+        if (f) {
+            fprintf(f, "%d\n", getpid());
+
+            int ret = fclose(f);
+            if (ret == EOF) /* check the return value of fclose */
+                debug(LOG_ERR, "fclose() on file %s was failed (%s)", pf, strerror(errno));
+        } else /* fopen return NULL, open file failed */
+            debug(LOG_ERR, "fopen() on flie %s was failed (%s)", pf, strerror(errno));
+    }
+
+    return;
+}

src/util.h

@@ -58,4 +58,7 @@ void close_icmp_socket(void);
 /** @brief ICMP Ping an IP */
 void icmp_ping(const char *);
 
+/** @brief Save pid of this wifidog in pid file */
+void save_pid_file(const char *);
+
 #endif                          /* _UTIL_H_ */