--fake-gen option: generate random-filled Fake Packets

This option is similar to fake-from-hex, but generates number of
packets with random payload.

Author: ValdikSS

README.md

@@ -67,6 +67,8 @@ Usage: goodbyedpi.exe [OPTION...]
  --fake-from-hex <value>  Load fake packets for Fake Request Mode from HEX values (like 1234abcDEF).
                           This option can be supplied multiple times, in this case each fake packet
                           would be sent on every request in the command line argument order.
+ --fake-gen <value>       Generate random-filled fake packets for Fake Request Mode, value of them
+                          (up to 30).
  --max-payload [value]    packets with TCP payload data more than [value] won't be processed.
                           Use this option to reduce CPU usage by skipping huge amount of data
                           (like file transfers) in already established sessions.

src/fakepackets.c

@@ -1,4 +1,5 @@
 #include <stdio.h>
+#define _CRT_RAND_S
 #include <stdlib.h>
 #include <stdbool.h>
 #include <ctype.h>
@@ -284,3 +285,26 @@ int fake_load_from_hex(const char *data) {
 
     return fake_add(finaldata, len / 2);
 }
+
+int fake_load_random(unsigned int count, unsigned int maxsize) {
+    if (count < 1 || count > sizeof(fakes) / sizeof(*fakes))
+        return 1;
+
+    unsigned int random = 0;
+
+    for (unsigned int i=0; i<count; i++) {
+        unsigned int len = 0;
+        if (rand_s(&len))
+            return 1;
+        len = 8 + (len % maxsize);
+
+        unsigned char *data = calloc(len, 1);
+        for (unsigned int j=0; j<len; j++) {
+            rand_s(&random);
+            data[j] = random % 0xFF;
+        }
+        if (fake_add(data, len))
+            return 2;
+    }
+    return 0;
+}

src/goodbyedpi.c

@@ -189,6 +189,7 @@ static struct option long_options[] = {
     {"reverse-frag",no_argument,       0,  '(' },
     {"max-payload", optional_argument, 0,  '|' },
     {"fake-from-hex", required_argument, 0,  'u' },
+    {"fake-gen",    required_argument, 0,  'j' },
     {"debug-exit",  optional_argument, 0,  'x' },
     {0,             0,                 0,   0  }
 };
@@ -946,6 +947,11 @@ int main(int argc, char *argv[]) {
                     printf("WARNING: bad fake HEX value %s\n", optarg);
                 }
                 break;
+            case 'j': // --fake-gen
+                if (fake_load_random(atoub(optarg, "Fake generator parameter error!"))) {
+                    puts("WARNING: fake generator has failed!");
+                }
+                break;
             case 'x': // --debug-exit
                 debug_exit = true;
                 break;
@@ -997,6 +1003,8 @@ int main(int argc, char *argv[]) {
                 " --fake-from-hex <value>  Load fake packets for Fake Request Mode from HEX values (like 1234abcDEF).\n"
                 "                          This option can be supplied multiple times, in this case each fake packet\n"
                 "                          would be sent on every request in the command line argument order.\n"
+                " --fake-gen <value>       Generate random-filled fake packets for Fake Request Mode, value of them\n"
+                "                          (up to 30).\n"
                 " --max-payload [value]    packets with TCP payload data more than [value] won't be processed.\n"
                 "                          Use this option to reduce CPU usage by skipping huge amount of data\n"
                 "                          (like file transfers) in already established sessions.\n"