mirror of
https://github.com/AFLplusplus/AFLplusplus.git
synced 2025-06-06 15:21:32 +00:00
308 lines
6.2 KiB
C
308 lines
6.2 KiB
C
/*
|
|
|
|
american fuzzy lop++ - strcmp() / memcmp() CompareCoverage library
|
|
------------------------------------------------------------------
|
|
|
|
Written and maintained by Andrea Fioraldi <andreafioraldi@gmail.com>
|
|
|
|
Copyright 2019 Andrea Fioraldi. All rights reserved.
|
|
|
|
Licensed under the Apache License, Version 2.0 (the "License");
|
|
you may not use this file except in compliance with the License.
|
|
You may obtain a copy of the License at:
|
|
|
|
http://www.apache.org/licenses/LICENSE-2.0
|
|
|
|
This Linux-only companion library allows you to instrument strcmp(),
|
|
memcmp(), and related functions to get compare coverage.
|
|
See README.compcov for more info.
|
|
|
|
*/
|
|
|
|
#include <stdio.h>
|
|
#include <string.h>
|
|
#include <ctype.h>
|
|
#include <sys/types.h>
|
|
#include <sys/shm.h>
|
|
|
|
#include "../../types.h"
|
|
#include "../../config.h"
|
|
|
|
#include "pmparser.h"
|
|
|
|
#ifndef __linux__
|
|
# error "Sorry, this library is Linux-specific for now!"
|
|
#endif /* !__linux__ */
|
|
|
|
/* Change this value to tune the compare coverage */
|
|
|
|
#define MAX_CMP_LENGTH 32
|
|
|
|
static u8 __compcov_loaded;
|
|
|
|
static void *__compcov_code_start,
|
|
*__compcov_code_end;
|
|
|
|
static u8 *__compcov_afl_map;
|
|
|
|
|
|
static size_t __strlen2(const char *s1, const char *s2, size_t max_length) {
|
|
// from https://github.com/googleprojectzero/CompareCoverage
|
|
|
|
size_t len = 0;
|
|
for (; len < max_length && s1[len] != '\0' && s2[len] != '\0'; len++) { }
|
|
return len;
|
|
}
|
|
|
|
/* Identify the binary boundaries in the memory mapping */
|
|
|
|
static void __compcov_load(void) {
|
|
|
|
__compcov_loaded = 1;
|
|
|
|
char *id_str = getenv(SHM_ENV_VAR);
|
|
int shm_id;
|
|
|
|
if (id_str) {
|
|
|
|
shm_id = atoi(id_str);
|
|
__compcov_afl_map = shmat(shm_id, NULL, 0);
|
|
|
|
if (__compcov_afl_map == (void*)-1) exit(1);
|
|
} else {
|
|
|
|
__compcov_afl_map = calloc(1, MAP_SIZE);
|
|
}
|
|
|
|
if (getenv("AFL_INST_LIBS")) {
|
|
|
|
__compcov_code_start = (void*)0;
|
|
__compcov_code_end = (void*)-1;
|
|
return;
|
|
}
|
|
|
|
char* bin_name = getenv("AFL_COMPCOV_BINNAME");
|
|
|
|
procmaps_iterator* maps = pmparser_parse(-1);
|
|
procmaps_struct* maps_tmp = NULL;
|
|
|
|
while ((maps_tmp = pmparser_next(maps)) != NULL) {
|
|
|
|
/* If AFL_COMPCOV_BINNAME is not set pick the first executable segment */
|
|
if (!bin_name || strstr(maps_tmp->pathname, bin_name) != NULL) {
|
|
|
|
if (maps_tmp->is_x) {
|
|
if (!__compcov_code_start)
|
|
__compcov_code_start = maps_tmp->addr_start;
|
|
if (!__compcov_code_end)
|
|
__compcov_code_end = maps_tmp->addr_end;
|
|
}
|
|
}
|
|
}
|
|
|
|
pmparser_free(maps);
|
|
}
|
|
|
|
|
|
static void __compcov_trace(u64 cur_loc, const u8* v0, const u8* v1, size_t n) {
|
|
|
|
size_t i;
|
|
|
|
for (i = 0; i < n && v0[i] == v1[i]; ++i) {
|
|
|
|
__compcov_afl_map[cur_loc +i]++;
|
|
}
|
|
}
|
|
|
|
/* Check an address against the list of read-only mappings. */
|
|
|
|
static u8 __compcov_is_in_bound(const void* ptr) {
|
|
|
|
return ptr >= __compcov_code_start && ptr < __compcov_code_end;
|
|
}
|
|
|
|
|
|
/* Replacements for strcmp(), memcmp(), and so on. Note that these will be used
|
|
only if the target is compiled with -fno-builtins and linked dynamically. */
|
|
|
|
#undef strcmp
|
|
|
|
int strcmp(const char* str1, const char* str2) {
|
|
|
|
void* retaddr = __builtin_return_address(0);
|
|
|
|
if (__compcov_is_in_bound(retaddr)) {
|
|
|
|
size_t n = __strlen2(str1, str2, MAX_CMP_LENGTH +1);
|
|
|
|
if (n <= MAX_CMP_LENGTH) {
|
|
|
|
u64 cur_loc = (u64)retaddr;
|
|
cur_loc = (cur_loc >> 4) ^ (cur_loc << 8);
|
|
cur_loc &= MAP_SIZE - 1;
|
|
|
|
__compcov_trace(cur_loc, str1, str2, n);
|
|
}
|
|
}
|
|
|
|
while (1) {
|
|
|
|
unsigned char c1 = *str1, c2 = *str2;
|
|
|
|
if (c1 != c2) return (c1 > c2) ? 1 : -1;
|
|
if (!c1) return 0;
|
|
str1++; str2++;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
#undef strncmp
|
|
|
|
int strncmp(const char* str1, const char* str2, size_t len) {
|
|
|
|
void* retaddr = __builtin_return_address(0);
|
|
|
|
if (__compcov_is_in_bound(retaddr)) {
|
|
|
|
size_t n = __strlen2(str1, str2, MAX_CMP_LENGTH +1);
|
|
n = MIN(n, len);
|
|
|
|
if (n <= MAX_CMP_LENGTH) {
|
|
|
|
u64 cur_loc = (u64)retaddr;
|
|
cur_loc = (cur_loc >> 4) ^ (cur_loc << 8);
|
|
cur_loc &= MAP_SIZE - 1;
|
|
|
|
__compcov_trace(cur_loc, str1, str2, n);
|
|
}
|
|
}
|
|
|
|
while (len--) {
|
|
|
|
unsigned char c1 = *str1, c2 = *str2;
|
|
|
|
if (!c1) return 0;
|
|
if (c1 != c2) return (c1 > c2) ? 1 : -1;
|
|
str1++; str2++;
|
|
|
|
}
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
|
#undef strcasecmp
|
|
|
|
int strcasecmp(const char* str1, const char* str2) {
|
|
|
|
void* retaddr = __builtin_return_address(0);
|
|
|
|
if (__compcov_is_in_bound(retaddr)) {
|
|
/* Fallback to strcmp, maybe improve in future */
|
|
|
|
size_t n = __strlen2(str1, str2, MAX_CMP_LENGTH +1);
|
|
|
|
if (n <= MAX_CMP_LENGTH) {
|
|
|
|
u64 cur_loc = (u64)retaddr;
|
|
cur_loc = (cur_loc >> 4) ^ (cur_loc << 8);
|
|
cur_loc &= MAP_SIZE - 1;
|
|
|
|
__compcov_trace(cur_loc, str1, str2, n);
|
|
}
|
|
}
|
|
|
|
while (1) {
|
|
|
|
unsigned char c1 = tolower(*str1), c2 = tolower(*str2);
|
|
|
|
if (c1 != c2) return (c1 > c2) ? 1 : -1;
|
|
if (!c1) return 0;
|
|
str1++; str2++;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
#undef strncasecmp
|
|
|
|
int strncasecmp(const char* str1, const char* str2, size_t len) {
|
|
|
|
void* retaddr = __builtin_return_address(0);
|
|
|
|
if (__compcov_is_in_bound(retaddr)) {
|
|
/* Fallback to strncmp, maybe improve in future */
|
|
|
|
size_t n = __strlen2(str1, str2, MAX_CMP_LENGTH +1);
|
|
n = MIN(n, len);
|
|
|
|
if (n <= MAX_CMP_LENGTH) {
|
|
|
|
u64 cur_loc = (u64)retaddr;
|
|
cur_loc = (cur_loc >> 4) ^ (cur_loc << 8);
|
|
cur_loc &= MAP_SIZE - 1;
|
|
|
|
__compcov_trace(cur_loc, str1, str2, n);
|
|
}
|
|
}
|
|
|
|
while (len--) {
|
|
|
|
unsigned char c1 = tolower(*str1), c2 = tolower(*str2);
|
|
|
|
if (!c1) return 0;
|
|
if (c1 != c2) return (c1 > c2) ? 1 : -1;
|
|
str1++; str2++;
|
|
|
|
}
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
|
#undef memcmp
|
|
|
|
int memcmp(const void* mem1, const void* mem2, size_t len) {
|
|
|
|
void* retaddr = __builtin_return_address(0);
|
|
|
|
if (__compcov_is_in_bound(retaddr)) {
|
|
|
|
size_t n = len;
|
|
|
|
if (n <= MAX_CMP_LENGTH) {
|
|
|
|
u64 cur_loc = (u64)retaddr;
|
|
cur_loc = (cur_loc >> 4) ^ (cur_loc << 8);
|
|
cur_loc &= MAP_SIZE - 1;
|
|
|
|
__compcov_trace(cur_loc, mem1, mem2, n);
|
|
}
|
|
}
|
|
|
|
while (len--) {
|
|
|
|
unsigned char c1 = *(const char*)mem1, c2 = *(const char*)mem2;
|
|
if (c1 != c2) return (c1 > c2) ? 1 : -1;
|
|
mem1++; mem2++;
|
|
|
|
}
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
/* Init code to open init the library. */
|
|
|
|
__attribute__((constructor)) void __compcov_init(void) {
|
|
|
|
__compcov_load();
|
|
}
|
|
|
|
|