c/troll23/troll23.c

   1 #define _GNU_SOURCE
   2 #include <stdio.h>
   3 #include <sys/types.h>
   4 #include <dlfcn.h>
   5 #include <stdarg.h>
   6
   7 int rand(void) {        return 23; }
   8 int random(void) {      return 23; }
   9
  10 static const char *redirect_name(const char *name)
  11 {
  12         if(strcmp(name,"/dev/random") == 0) return "/dev/zero";
  13         if(strcmp(name,"/dev/urandom") == 0) return "/dev/zero";
  14         return name;
  15 }
  16
  17 int open(const char *filename, int flags, ...)
  18 {
  19         static int (*open_orig)(const char *, int, mode_t);
  20         int ret;
  21         va_list ap;
  22         mode_t mode;
  23
  24         if (!open_orig) {
  25                 open_orig = dlsym(RTLD_NEXT, "open");
  26         }
  27
  28         va_start(ap, flags);
  29         mode = va_arg(ap, mode_t);
  30         va_end(ap);
  31
  32         ret = open_orig(redirect_name(filename), flags, mode);
  33
  34         printf("open(\"%s\", 0x%x, %o) -> %d\n", filename, flags, mode, ret);
  35
  36         return ret;
  37 }