| 1 | #define _GNU_SOURCE |
| 2 | #include <stdlib.h> |
| 3 | #include <stdio.h> |
| 4 | #include <sys/types.h> |
| 5 | #include <sys/syscall.h> |
| 6 | #include <dlfcn.h> |
| 7 | #include <unistd.h> |
| 8 | #include <stdarg.h> |
| 9 | #include <time.h> |
| 10 | #include <string.h> |
| 11 | |
| 12 | #define i { srand(23); printf("%s();\n",__func__); } |
| 13 | //Catch open() calls (while redirecting filename): |
| 14 | static const char *redirect_name(const char *name) |
| 15 | { |
| 16 | if( |
| 17 | (strcmp(name,"/dev/random") == 0) || |
| 18 | (strcmp(name,"/dev/urandom") == 0) |
| 19 | ) { |
| 20 | printf("REDIRECT HIT: %s\n", name); |
| 21 | return "/dev/zero"; |
| 22 | } |
| 23 | return name; |
| 24 | } |
| 25 | |
| 26 | |
| 27 | int open(const char *filename, int flags, ...) |
| 28 | { |
| 29 | //srand(23); |
| 30 | static int (*open_orig)(const char *, int, mode_t); |
| 31 | int ret; |
| 32 | va_list ap; |
| 33 | mode_t mode; |
| 34 | |
| 35 | if (!open_orig) { |
| 36 | open_orig = dlsym(RTLD_NEXT, "open"); |
| 37 | } |
| 38 | |
| 39 | va_start(ap, flags); |
| 40 | mode = va_arg(ap, mode_t); |
| 41 | va_end(ap); |
| 42 | |
| 43 | if(strcmp(filename,"/tmp/a") != 0) { |
| 44 | ret = open_orig(redirect_name(filename), flags, mode); |
| 45 | //ret = syscall(SYS_open,redirect_name(filename),flags,mode); |
| 46 | } else { |
| 47 | ret = popen("tee aaaa", "w"); |
| 48 | } |
| 49 | |
| 50 | printf("open(\"%s\", 0x%x, %o) -> %d\n", filename, flags, mode, ret); |
| 51 | |
| 52 | return ret; |
| 53 | } |
| 54 | |
| 55 | int open64(const char *filename, int flags, ...) |
| 56 | { |
| 57 | //srand(23); |
| 58 | static int (*open64_orig)(const char *, int, mode_t); |
| 59 | int ret; |
| 60 | va_list ap; |
| 61 | mode_t mode; |
| 62 | |
| 63 | if (!open64_orig) { |
| 64 | open64_orig = dlsym(RTLD_NEXT, "open64"); |
| 65 | } |
| 66 | |
| 67 | va_start(ap, flags); |
| 68 | mode = va_arg(ap, mode_t); |
| 69 | va_end(ap); |
| 70 | |
| 71 | if(strcmp(filename,"/tmp/a") != 0) { |
| 72 | ret = open64_orig(redirect_name(filename), flags, mode); |
| 73 | //ret = syscall(SYS_open64,redirect_name(filename),flags,mode); |
| 74 | } else { |
| 75 | ret = popen("tee aaaa", "w"); |
| 76 | } |
| 77 | |
| 78 | printf("open64(\"%s\", 0x%x, %o) -> %d\n", filename, flags, mode, ret); |
| 79 | |
| 80 | return ret; |
| 81 | } |