c/cano/old/cano3.c

   1 #define _GNU_SOURCE
   2 /*
   3 #include <stdlib.h>
   4 #include <sys/types.h>
   5 #include <unistd.h>
   6 #include <stdarg.h>
   7 #include <time.h>
   8 #include <string.h>
   9
  10        #include <sys/types.h>
  11        #include <sys/stat.h>
  12        #include <fcntl.h>
  13 */
  14 #include <dlfcn.h>
  15 #include <stdio.h>
  16 #include <sys/syscall.h>
  17 #include <linux/limits.h>
  18
  19 #define i { srand(23); fprintf(stderr,"%s();\n",__func__); }
  20 //Catch open() calls (while redirecting filename):
  21
  22 static const char *fd_to_path(int fd) {
  23         static char path[PATH_MAX];
  24         sprintf(path,"/proc/self/fd/%d",fd);
  25         int l = (int) readlink((char * __restrict__) path, path, PATH_MAX);
  26         path[l]=0;
  27         return path;
  28 }
  29
  30 int close(int fd) {
  31         //fputs(fd_to_path(fd),stderr);
  32         fprintf(stderr,"%s(%d,%s);\n",__func__,fd,fd_to_path(fd));
  33         if(fd>2) return syscall(SYS_close,fd);
  34 }
  35 int fclose(FILE *fd) {
  36         //fputs(fd_to_path(fd),stderr);
  37         fprintf(stderr,"%s(%d,%d,%s);\n",__func__,fileno(fd),fd,fd_to_path(fileno(fd)));
  38         static ssize_t (*fclose_orig)(FILE *fd);
  39         if (!fclose_orig) {
  40                 fclose_orig = dlsym(RTLD_NEXT, "fclose");
  41         }
  42         return fclose_orig(fd);
  43         //return syscall(SYS_close,fileno(fd));
  44 }
  45 /*
  46 ssize_t write(int fd, const void *buf, size_t count) {
  47         //fputs(fd_to_path(fd),stderr);
  48         printf("%d",fd);
  49         i;
  50         return syscall(SYS_write,fd,buf,count);
  51 }
  52 */
  53 /*
  54 static const char *redirect_name(const char *name)
  55 {
  56         if(
  57                 (strcmp(name,"/dev/random") == 0) ||
  58                 (strcmp(name,"/dev/urandom") == 0)
  59         ) {
  60                 printf("REDIRECT HIT: %s\n", name);
  61                 return "/dev/zero";
  62         }
  63         return name;
  64 }
  65
  66
  67 int open(const char *filename, int flags, ...)
  68 {
  69         //srand(23);
  70         static int (*open_orig)(const char *, int, mode_t);
  71         int ret;
  72         va_list ap;
  73         mode_t mode;
  74
  75         if (!open_orig) {
  76                 open_orig = dlsym(RTLD_NEXT, "open");
  77         }
  78
  79         va_start(ap, flags);
  80         mode = va_arg(ap, mode_t);
  81         va_end(ap);
  82
  83         if(strcmp(filename,"/tmp/lol.txt.asc") != 0) {
  84                 ret = open_orig(redirect_name(filename), flags, mode);
  85                 //ret = syscall(SYS_open,redirect_name(filename),flags,mode);
  86         } else {
  87                 if(flags & O_RDONLY) {
  88                         ret = fileno(popen("cat aaaa", "r"));
  89                 } else {
  90                         ret = fileno(popen("tee aaaa", "w"));
  91                 }
  92         }
  93
  94         printf("open(\"%s\", 0x%x, %o) -> %d\n", filename, flags, mode, ret);
  95
  96         return ret;
  97 }
  98
  99 */