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 22 extern "C" { 23 #endif 24 25 typedef 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). 32 struct 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(). 43 typedef 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. 47 dfsan_label dfsan_union(dfsan_label l1, dfsan_label l2); 48 49 /// Creates and returns a base label with the given description and user data. 50 dfsan_label dfsan_create_label(const char *desc, void *userdata); 51 52 /// Sets the label for each address in [addr,addr+size) to \c label. 53 void 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. 57 void 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. 65 dfsan_label dfsan_get_label(long data); 66 67 /// Retrieves the label associated with the data at the given address. 68 dfsan_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. 71 const struct dfsan_label_info *dfsan_get_label_info(dfsan_label label); 72 73 /// Returns whether the given label label contains the label elem. 74 int 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. 78 dfsan_label dfsan_has_label_with_desc(dfsan_label label, const char *desc); 79 80 /// Returns the number of labels allocated. 81 size_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. 86 void 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> 92 void 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. 100 void 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); 103 void 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" 108 109 template <typename T> 110 void 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
