X-Git-Url: http://git.grml.org/?p=grml-scripts.git;a=blobdiff_plain;f=compile%2Fvmware-detect.c;h=c99e36ff05e67911839177a562088a1b47ad8d3f;hp=fad9b962ba7612d4d2032c466cda490b157083ba;hb=12b3ac5b42b404e8f6b4d70fb9530b82213118f4;hpb=ebf978230527071b156967e6b3298555122c31fa

diff --git a/compile/vmware-detect.c b/compile/vmware-detect.c
index fad9b96..c99e36f 100644
--- a/compile/vmware-detect.c
+++ b/compile/vmware-detect.c
@@ -1,7 +1,16 @@
+/* Filename:      vmware-detect.c
+*  Purpose:       Detect if running inside vmware
+*  Authors:       grml-team (grml.org), (c) Michael Gebetsroither <gebi@grml.org>
+*  Bug-Reports:   see http://grml.org/bugs/
+*  License:       This file is licensed under the GPL v2.
+*******************************************************************************/
+// return 0 if running inside vmware, 1 otherwise
+
 #include "string.h"
 #include "unistd.h"
 #include "stdio.h"
 #include "stdlib.h"
+#include "signal.h"
 
 #define WRITE(x) write(1, x, strlen(x))
 #define DWRITE(x) do{ \
@@ -12,6 +21,12 @@
 #define FALSE 0
 #define TRUE !FALSE
 
+/* doc:
+ * vmware IO backdoor: http://chitchat.at.infoseek.co.jp/vmware/backdoor.html
+ * http://www.honeynet.org/papers/bots/botnet-code.html
+ * http://www.codegurus.be/codegurus/Programming/virtualpc&vmware_en.htm
+ */
+
 // from libowfat {{{
 static inline char tohex(char c) {
   return c>=10?c-10+'a':c+'0';
@@ -33,22 +48,26 @@ unsigned int fmt_xlong(char *dest,unsigned long i) {
 void printIdtr(const unsigned char* idtr, unsigned size)
 {
     unsigned i;
-    for(i=0; i<=size; ++i) {
+    for(i=0; i<size; ++i) {
         char out[4] = {0};
         fmt_xlong(out, idtr[i]);
+        if(strlen(out) == 1)
+            WRITE("0");
         WRITE(out);
     }
     WRITE("\n");
 }
 
-// i386 {{{
-#if defined (__i386__)
+// i386 and x86-64 {{{
+#if defined (__i386__) || defined (__x86_64__)
 int checkVmware(const int debug)
 {
-    unsigned char idtr[6] = {0};
+    unsigned char idtr[10] = {0};
     asm("sidt %0" : "=m" (idtr));
     if(debug)
-        printIdtr(idtr, 6);
+        printIdtr(idtr, sizeof(idtr));
+    // should normally be the case on amd64, but does not work
+    //return (0xff==idtr[9]) ? 1 : 0;
     return (0xff==idtr[5]) ? 1 : 0;
 }
 int checkVmwareIO()
@@ -73,20 +92,6 @@ int checkVmwareIO()
 }
 // }}}
 
-// x86-64 {{{
-#elif defined (__x86_64__)
-// only guessed, possible need to check against 0xffff?
-int checkVmware(const int debug)
-{
-    unsigned char idtr[10];
-    asm("sidt %0" : "=m" (idtr));
-    if(debug)
-        printIdtr(idtr, 10);
-    return (0xff==idtr[9]) ? 1 : 0;
-}
-int checkVmwareIO() { return 0; }
-// }}}
-
 // others {{{
 #else
 // vmware runs only on the archs above
@@ -95,6 +100,8 @@ int checkVmwareIO() { return 0; }
 #endif
 // }}}
 
+static int Killed = FALSE;
+
 // returns 0 if running inside vmware, 1 otherwise
 int main(int argc, char* argv[]) {
     int debug = FALSE;
@@ -113,16 +120,24 @@ int main(int argc, char* argv[]) {
         DWRITE("true\n");
 
     // never returns if not running under vmware
-    void dummy() { DWRITE("false\n"); exit(1); }
+    void dummy() { Killed=TRUE; DWRITE("false\n"); exit(1); }
     signal(SIGSEGV, dummy);
     DWRITE("ioport-check: ");
     b = checkVmwareIO();
     if(b) {
         DWRITE("true\n");
         return EXIT_SUCCESS;
+    } else {
+        if(!Killed) {
+            // check unusable or not implemented
+            DWRITE("false\n");
+            DWRITE("Check not implemented, yet!\n");
+            return a ? EXIT_SUCCESS : EXIT_FAILURE;
+        } else {
+            // never reached
+            WRITE("Error: IO check hasn't killed the program but no vmware found either!\n");
+            return EXIT_FAILURE;
+        }
     }
-    // never reached
-    WRITE("Error: IO check hasn't killed the program but no vmware found either!\n");
-    return EXIT_FAILURE;
 }
 // vim: foldmethod=marker