src/compiler-rt/include/sanitizer/dfsan_interface.h

   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