HZ13: Add support for user-configurable SSL error response code

README.md

@@ -66,3 +66,4 @@ Sources
 * https://github.com/flexiondotorg/nullserv (defunct)
 * http://www.linksysinfo.org/index.php?threads/pixelserv-compiled-to-run-on-router-wrt54g.30509/page-3#post-229342
 * http://www.dd-wrt.com/phpBB2/viewtopic.php?p=685201
+* https://en.wikipedia.org/wiki/Transport_Layer_Security#Alert_protocol

pixelserv.c

@@ -116,6 +116,7 @@ int main (int argc, char* argv[]) // program start
 #ifdef DEBUG
   int warning_time = 0;
 #endif //DEBUG
+  char ssl_alert = DEFAULT_SSL_ALERT;
 
   SET_LINE_NUMBER(__LINE__);
 
@@ -139,6 +140,9 @@ int main (int argc, char* argv[]) // program start
       if ((i + 1) < argc) {
         // switch on parameter letter and process subsequent argument
         switch (argv[i++][1]) {
+          case 'c':
+            ssl_alert = (char)strtol(argv[i], NULL, 10);
+          continue;
 #ifdef IF_MODE
           case 'n':
             ifname = argv[i];
@@ -192,6 +196,7 @@ int main (int argc, char* argv[]) // program start
     printf("Usage:%s"
            " [IP No/hostname (all)]"
            " [-2 (disables HTTP 204 reply to generate_204 URLs)]"
+           " [-c ssl_alert_code (49 - access denied)]"
 #ifndef TEST
            " [-f (stay in foreground - don't daemonize)]"
 #endif // !TEST
@@ -565,6 +570,7 @@ int main (int argc, char* argv[]) // program start
                     ,argv[0]
                     ,do_204
                     ,do_redirect
+                    ,ssl_alert
 #ifdef DEBUG
                     ,warning_time
 #endif //DEBUG

socket_handler.c

@@ -214,13 +214,6 @@ static const char httpnull_ico[] =
   "\x00\x00\x00\x00" // XOR B G R
   "\x80\xF8\x9C\x41"; // AND ?
 
-static const char SSL_no[] =
-  "\x15"     // Alert (21)
-  "\x03\x00" // Version 3.0
-  "\x00\x02" // length 2
-  "\x02"     // fatal
-  "\x31";    // 0 close notify, 0x28 Handshake failure 40, 0x31 TLS access denied 49
-
 // private functions for socket_handler() use
 #ifdef HEX_DUMP
 // from http://sws.dett.de/mini/hexdump-c/
@@ -395,6 +388,7 @@ void socket_handler(int argc
                    ,const char* const program_name
                    ,const int do_204
                    ,const int do_redirect
+                   ,const char ssl_alert
 #ifdef DEBUG
                    ,const int warning_time
 #endif //DEBUG
@@ -414,6 +408,14 @@ void socket_handler(int argc
   char* version_string = NULL;
   char* stat_string = NULL;
   struct timespec start_time = {0, 0};
+  const char SSL_no[] = {
+    '\x15'        // Alert (21)
+   ,'\x03','\x00' // Version 3.0
+   ,'\x00','\x02' // length 02
+   ,'\x02'        // fatal
+   ,ssl_alert     // 0 close notify, 0x28 Handshake failure 40, 0x31 TLS access denied 49
+   ,'\x00'        // string terminator (not part of actual response)
+  };
 #ifdef DEBUG
   double time_msec = 0.0;
   int do_warning = (warning_time > 0);

socket_handler.h

@@ -43,6 +43,7 @@ void socket_handler(int argc
                    ,const char* const program_name
                    ,const int do_204
                    ,const int do_redirect
+                   ,const char ssl_alert
 #ifdef DEBUG
                    ,const int warning_time
 #endif //DEBUG

util.h

@@ -22,7 +22,7 @@
 #include <time.h>               // struct timespec, clock_gettime(), difftime()
 
 // preprocessor defines
-#define VERSION "V35.HZ12"
+#define VERSION "V35.HZ13"
 
 #define BACKLOG SOMAXCONN       // how many pending connections queue will hold
 #define CHAR_BUF_SIZE 4095      // surprising how big requests can be with cookies and lengthy yahoo url!
@@ -63,6 +63,8 @@ static unsigned long LINE_NUMBER = __LINE__;
 # define SET_LINE_NUMBER(x)
 #endif //DEBUG
 
+#define DEFAULT_SSL_ALERT (char)49
+
 // cross-thread count variables
 extern volatile sig_atomic_t count; // req
 extern volatile sig_atomic_t avg; // cumulative moving average request size