| //===-- dfsan_interface.h -------------------------------------------------===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This file is a part of DataFlowSanitizer. |
| // |
| // Public interface header. |
| //===----------------------------------------------------------------------===// |
| #ifndef DFSAN_INTERFACE_H |
| #define DFSAN_INTERFACE_H |
| |
| #include <stddef.h> |
| #include <stdint.h> |
| #include <sanitizer/common_interface_defs.h> |
| |
| #ifdef __cplusplus |
| extern "C" { |
| #endif |
| |
| typedef uint16_t dfsan_label; |
| |
| /// Stores information associated with a specific label identifier. A label |
| /// may be a base label created using dfsan_create_label, with associated |
| /// text description and user data, or an automatically created union label, |
| /// which represents the union of two label identifiers (which may themselves |
| /// be base or union labels). |
| struct dfsan_label_info { |
| // Fields for union labels, set to 0 for base labels. |
| dfsan_label l1; |
| dfsan_label l2; |
| |
| // Fields for base labels. |
| const char *desc; |
| void *userdata; |
| }; |
| |
| /// Signature of the callback argument to dfsan_set_write_callback(). |
| typedef void (*dfsan_write_callback_t)(int fd, const void *buf, size_t count); |
| |
| /// Computes the union of \c l1 and \c l2, possibly creating a union label in |
| /// the process. |
| dfsan_label dfsan_union(dfsan_label l1, dfsan_label l2); |
| |
| /// Creates and returns a base label with the given description and user data. |
| dfsan_label dfsan_create_label(const char *desc, void *userdata); |
| |
| /// Sets the label for each address in [addr,addr+size) to \c label. |
| void dfsan_set_label(dfsan_label label, void *addr, size_t size); |
| |
| /// Sets the label for each address in [addr,addr+size) to the union of the |
| /// current label for that address and \c label. |
| void dfsan_add_label(dfsan_label label, void *addr, size_t size); |
| |
| /// Retrieves the label associated with the given data. |
| /// |
| /// The type of 'data' is arbitrary. The function accepts a value of any type, |
| /// which can be truncated or extended (implicitly or explicitly) as necessary. |
| /// The truncation/extension operations will preserve the label of the original |
| /// value. |
| dfsan_label dfsan_get_label(long data); |
| |
| /// Retrieves the label associated with the data at the given address. |
| dfsan_label dfsan_read_label(const void *addr, size_t size); |
| |
| /// Retrieves a pointer to the dfsan_label_info struct for the given label. |
| const struct dfsan_label_info *dfsan_get_label_info(dfsan_label label); |
| |
| /// Returns whether the given label label contains the label elem. |
| int dfsan_has_label(dfsan_label label, dfsan_label elem); |
| |
| /// If the given label label contains a label with the description desc, returns |
| /// that label, else returns 0. |
| dfsan_label dfsan_has_label_with_desc(dfsan_label label, const char *desc); |
| |
| /// Returns the number of labels allocated. |
| size_t dfsan_get_label_count(void); |
| |
| /// Flushes the DFSan shadow, i.e. forgets about all labels currently associated |
| /// with the application memory. Will work only if there are no other |
| /// threads executing DFSan-instrumented code concurrently. |
| /// Use this call to start over the taint tracking within the same procces. |
| void dfsan_flush(void); |
| |
| /// Sets a callback to be invoked on calls to write(). The callback is invoked |
| /// before the write is done. The write is not guaranteed to succeed when the |
| /// callback executes. Pass in NULL to remove any callback. |
| void dfsan_set_write_callback(dfsan_write_callback_t labeled_write_callback); |
| |
| /// Writes the labels currently used by the program to the given file |
| /// descriptor. The lines of the output have the following format: |
| /// |
| /// <label> <parent label 1> <parent label 2> <label description if any> |
| void dfsan_dump_labels(int fd); |
| |
| /// Interceptor hooks. |
| /// Whenever a dfsan's custom function is called the corresponding |
| /// hook is called it non-zero. The hooks should be defined by the user. |
| /// The primary use case is taint-guided fuzzing, where the fuzzer |
| /// needs to see the parameters of the function and the labels. |
| /// FIXME: implement more hooks. |
| void dfsan_weak_hook_memcmp(void *caller_pc, const void *s1, const void *s2, |
| size_t n, dfsan_label s1_label, |
| dfsan_label s2_label, dfsan_label n_label); |
| void dfsan_weak_hook_strncmp(void *caller_pc, const char *s1, const char *s2, |
| size_t n, dfsan_label s1_label, |
| dfsan_label s2_label, dfsan_label n_label); |
| #ifdef __cplusplus |
| } // extern "C" |
| |
| template <typename T> |
| void dfsan_set_label(dfsan_label label, T &data) { // NOLINT |
| dfsan_set_label(label, (void *)&data, sizeof(T)); |
| } |
| |
| #endif |
| |
| #endif // DFSAN_INTERFACE_H |