Logan Chien | 55afb0a | 2018-10-15 10:42:14 +0800 | [diff] [blame] | 1 | //===-- dfsan_interface.h -------------------------------------------------===// |
| 2 | // |
Logan Chien | dbcf412 | 2019-03-21 10:50:25 +0800 | [diff] [blame] | 3 | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| 4 | // See https://llvm.org/LICENSE.txt for license information. |
| 5 | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
Logan Chien | 55afb0a | 2018-10-15 10:42:14 +0800 | [diff] [blame] | 6 | // |
| 7 | //===----------------------------------------------------------------------===// |
| 8 | // |
| 9 | // This file is a part of DataFlowSanitizer. |
| 10 | // |
| 11 | // Public interface header. |
| 12 | //===----------------------------------------------------------------------===// |
| 13 | #ifndef DFSAN_INTERFACE_H |
| 14 | #define DFSAN_INTERFACE_H |
| 15 | |
| 16 | #include <stddef.h> |
| 17 | #include <stdint.h> |
| 18 | #include <sanitizer/common_interface_defs.h> |
| 19 | |
| 20 | #ifdef __cplusplus |
| 21 | extern "C" { |
| 22 | #endif |
| 23 | |
| 24 | typedef uint16_t dfsan_label; |
| 25 | |
| 26 | /// Stores information associated with a specific label identifier. A label |
| 27 | /// may be a base label created using dfsan_create_label, with associated |
| 28 | /// text description and user data, or an automatically created union label, |
| 29 | /// which represents the union of two label identifiers (which may themselves |
| 30 | /// be base or union labels). |
| 31 | struct dfsan_label_info { |
| 32 | // Fields for union labels, set to 0 for base labels. |
| 33 | dfsan_label l1; |
| 34 | dfsan_label l2; |
| 35 | |
| 36 | // Fields for base labels. |
| 37 | const char *desc; |
| 38 | void *userdata; |
| 39 | }; |
| 40 | |
| 41 | /// Signature of the callback argument to dfsan_set_write_callback(). |
| 42 | typedef void (*dfsan_write_callback_t)(int fd, const void *buf, size_t count); |
| 43 | |
| 44 | /// Computes the union of \c l1 and \c l2, possibly creating a union label in |
| 45 | /// the process. |
| 46 | dfsan_label dfsan_union(dfsan_label l1, dfsan_label l2); |
| 47 | |
| 48 | /// Creates and returns a base label with the given description and user data. |
| 49 | dfsan_label dfsan_create_label(const char *desc, void *userdata); |
| 50 | |
| 51 | /// Sets the label for each address in [addr,addr+size) to \c label. |
| 52 | void dfsan_set_label(dfsan_label label, void *addr, size_t size); |
| 53 | |
| 54 | /// Sets the label for each address in [addr,addr+size) to the union of the |
| 55 | /// current label for that address and \c label. |
| 56 | void dfsan_add_label(dfsan_label label, void *addr, size_t size); |
| 57 | |
| 58 | /// Retrieves the label associated with the given data. |
| 59 | /// |
| 60 | /// The type of 'data' is arbitrary. The function accepts a value of any type, |
| 61 | /// which can be truncated or extended (implicitly or explicitly) as necessary. |
| 62 | /// The truncation/extension operations will preserve the label of the original |
| 63 | /// value. |
| 64 | dfsan_label dfsan_get_label(long data); |
| 65 | |
| 66 | /// Retrieves the label associated with the data at the given address. |
| 67 | dfsan_label dfsan_read_label(const void *addr, size_t size); |
| 68 | |
| 69 | /// Retrieves a pointer to the dfsan_label_info struct for the given label. |
| 70 | const struct dfsan_label_info *dfsan_get_label_info(dfsan_label label); |
| 71 | |
| 72 | /// Returns whether the given label label contains the label elem. |
| 73 | int dfsan_has_label(dfsan_label label, dfsan_label elem); |
| 74 | |
| 75 | /// If the given label label contains a label with the description desc, returns |
| 76 | /// that label, else returns 0. |
| 77 | dfsan_label dfsan_has_label_with_desc(dfsan_label label, const char *desc); |
| 78 | |
| 79 | /// Returns the number of labels allocated. |
| 80 | size_t dfsan_get_label_count(void); |
| 81 | |
Logan Chien | df4f766 | 2019-09-04 16:45:23 -0700 | [diff] [blame] | 82 | /// Flushes the DFSan shadow, i.e. forgets about all labels currently associated |
| 83 | /// with the application memory. Will work only if there are no other |
| 84 | /// threads executing DFSan-instrumented code concurrently. |
| 85 | /// Use this call to start over the taint tracking within the same procces. |
| 86 | void dfsan_flush(void); |
| 87 | |
Logan Chien | 55afb0a | 2018-10-15 10:42:14 +0800 | [diff] [blame] | 88 | /// Sets a callback to be invoked on calls to write(). The callback is invoked |
| 89 | /// before the write is done. The write is not guaranteed to succeed when the |
| 90 | /// callback executes. Pass in NULL to remove any callback. |
| 91 | void dfsan_set_write_callback(dfsan_write_callback_t labeled_write_callback); |
| 92 | |
| 93 | /// Writes the labels currently used by the program to the given file |
| 94 | /// descriptor. The lines of the output have the following format: |
| 95 | /// |
| 96 | /// <label> <parent label 1> <parent label 2> <label description if any> |
| 97 | void dfsan_dump_labels(int fd); |
| 98 | |
| 99 | /// Interceptor hooks. |
| 100 | /// Whenever a dfsan's custom function is called the corresponding |
| 101 | /// hook is called it non-zero. The hooks should be defined by the user. |
| 102 | /// The primary use case is taint-guided fuzzing, where the fuzzer |
| 103 | /// needs to see the parameters of the function and the labels. |
| 104 | /// FIXME: implement more hooks. |
| 105 | void dfsan_weak_hook_memcmp(void *caller_pc, const void *s1, const void *s2, |
| 106 | size_t n, dfsan_label s1_label, |
| 107 | dfsan_label s2_label, dfsan_label n_label); |
| 108 | void dfsan_weak_hook_strncmp(void *caller_pc, const char *s1, const char *s2, |
| 109 | size_t n, dfsan_label s1_label, |
| 110 | dfsan_label s2_label, dfsan_label n_label); |
| 111 | #ifdef __cplusplus |
| 112 | } // extern "C" |
| 113 | |
| 114 | template <typename T> |
| 115 | void dfsan_set_label(dfsan_label label, T &data) { // NOLINT |
| 116 | dfsan_set_label(label, (void *)&data, sizeof(T)); |
| 117 | } |
| 118 | |
| 119 | #endif |
| 120 | |
| 121 | #endif // DFSAN_INTERFACE_H |