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>
dfsan_set_label(dfsan_label label,T & data)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