1//===-- dfsan_interface.h -------------------------------------------------===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// This file is a part of DataFlowSanitizer. 11// 12// Public interface header. 13//===----------------------------------------------------------------------===// 14#ifndef DFSAN_INTERFACE_H 15#define DFSAN_INTERFACE_H 16 17#include <stddef.h> 18#include <stdint.h> 19#include <sanitizer/common_interface_defs.h> 20 21#ifdef __cplusplus 22extern "C" { 23#endif 24 25typedef uint16_t dfsan_label; 26 27/// Stores information associated with a specific label identifier. A label 28/// may be a base label created using dfsan_create_label, with associated 29/// text description and user data, or an automatically created union label, 30/// which represents the union of two label identifiers (which may themselves 31/// be base or union labels). 32struct dfsan_label_info { 33 // Fields for union labels, set to 0 for base labels. 34 dfsan_label l1; 35 dfsan_label l2; 36 37 // Fields for base labels. 38 const char *desc; 39 void *userdata; 40}; 41 42/// Signature of the callback argument to dfsan_set_write_callback(). 43typedef void (*dfsan_write_callback_t)(int fd, const void *buf, size_t count); 44 45/// Computes the union of \c l1 and \c l2, possibly creating a union label in 46/// the process. 47dfsan_label dfsan_union(dfsan_label l1, dfsan_label l2); 48 49/// Creates and returns a base label with the given description and user data. 50dfsan_label dfsan_create_label(const char *desc, void *userdata); 51 52/// Sets the label for each address in [addr,addr+size) to \c label. 53void dfsan_set_label(dfsan_label label, void *addr, size_t size); 54 55/// Sets the label for each address in [addr,addr+size) to the union of the 56/// current label for that address and \c label. 57void dfsan_add_label(dfsan_label label, void *addr, size_t size); 58 59/// Retrieves the label associated with the given data. 60/// 61/// The type of 'data' is arbitrary. The function accepts a value of any type, 62/// which can be truncated or extended (implicitly or explicitly) as necessary. 63/// The truncation/extension operations will preserve the label of the original 64/// value. 65dfsan_label dfsan_get_label(long data); 66 67/// Retrieves the label associated with the data at the given address. 68dfsan_label dfsan_read_label(const void *addr, size_t size); 69 70/// Retrieves a pointer to the dfsan_label_info struct for the given label. 71const struct dfsan_label_info *dfsan_get_label_info(dfsan_label label); 72 73/// Returns whether the given label label contains the label elem. 74int dfsan_has_label(dfsan_label label, dfsan_label elem); 75 76/// If the given label label contains a label with the description desc, returns 77/// that label, else returns 0. 78dfsan_label dfsan_has_label_with_desc(dfsan_label label, const char *desc); 79 80/// Returns the number of labels allocated. 81size_t dfsan_get_label_count(void); 82 83/// Sets a callback to be invoked on calls to write(). The callback is invoked 84/// before the write is done. The write is not guaranteed to succeed when the 85/// callback executes. Pass in NULL to remove any callback. 86void dfsan_set_write_callback(dfsan_write_callback_t labeled_write_callback); 87 88/// Writes the labels currently used by the program to the given file 89/// descriptor. The lines of the output have the following format: 90/// 91/// <label> <parent label 1> <parent label 2> <label description if any> 92void dfsan_dump_labels(int fd); 93 94/// Interceptor hooks. 95/// Whenever a dfsan's custom function is called the corresponding 96/// hook is called it non-zero. The hooks should be defined by the user. 97/// The primary use case is taint-guided fuzzing, where the fuzzer 98/// needs to see the parameters of the function and the labels. 99/// FIXME: implement more hooks. 100void dfsan_weak_hook_memcmp(void *caller_pc, const void *s1, const void *s2, 101 size_t n, dfsan_label s1_label, 102 dfsan_label s2_label, dfsan_label n_label); 103void dfsan_weak_hook_strncmp(void *caller_pc, const char *s1, const char *s2, 104 size_t n, dfsan_label s1_label, 105 dfsan_label s2_label, dfsan_label n_label); 106#ifdef __cplusplus 107} // extern "C" 108 109template <typename T> 110void dfsan_set_label(dfsan_label label, T &data) { // NOLINT 111 dfsan_set_label(label, (void *)&data, sizeof(T)); 112} 113 114#endif 115 116#endif // DFSAN_INTERFACE_H 117