libsanitizer/include/sanitizer/dfsan_interface.h

   1 //===-- dfsan_interface.h -------------------------------------------------===//
   2 //
   3 // This file is distributed under the University of Illinois Open Source
   4 // License. See LICENSE.TXT for details.
   5 //
   6 //===----------------------------------------------------------------------===//
   7 //
   8 // This file is a part of DataFlowSanitizer.
   9 //
  10 // Public interface header.
  11 //===----------------------------------------------------------------------===//
  12 #ifndef DFSAN_INTERFACE_H
  13 #define DFSAN_INTERFACE_H
  14
  15 #include <stddef.h>
  16 #include <stdint.h>
  17 #include <sanitizer/common_interface_defs.h>
  18
  19 #ifdef __cplusplus
  20 extern "C" {
  21 #endif
  22
  23 typedef uint16_t dfsan_label;
  24
  25 /// Stores information associated with a specific label identifier.  A label
  26 /// may be a base label created using dfsan_create_label, with associated
  27 /// text description and user data, or an automatically created union label,
  28 /// which represents the union of two label identifiers (which may themselves
  29 /// be base or union labels).
  30 struct dfsan_label_info {
  31   // Fields for union labels, set to 0 for base labels.
  32   dfsan_label l1;
  33   dfsan_label l2;
  34
  35   // Fields for base labels.
  36   const char *desc;
  37   void *userdata;
  38 };
  39
  40 /// Signature of the callback argument to dfsan_set_write_callback().
  41 typedef void (*dfsan_write_callback_t)(int fd, const void *buf, size_t count);
  42
  43 /// Computes the union of \c l1 and \c l2, possibly creating a union label in
  44 /// the process.
  45 dfsan_label dfsan_union(dfsan_label l1, dfsan_label l2);
  46
  47 /// Creates and returns a base label with the given description and user data.
  48 dfsan_label dfsan_create_label(const char *desc, void *userdata);
  49
  50 /// Sets the label for each address in [addr,addr+size) to \c label.
  51 void dfsan_set_label(dfsan_label label, void *addr, size_t size);
  52
  53 /// Sets the label for each address in [addr,addr+size) to the union of the
  54 /// current label for that address and \c label.
  55 void dfsan_add_label(dfsan_label label, void *addr, size_t size);
  56
  57 /// Retrieves the label associated with the given data.
  58 ///
  59 /// The type of 'data' is arbitrary.  The function accepts a value of any type,
  60 /// which can be truncated or extended (implicitly or explicitly) as necessary.
  61 /// The truncation/extension operations will preserve the label of the original
  62 /// value.
  63 dfsan_label dfsan_get_label(long data);
  64
  65 /// Retrieves the label associated with the data at the given address.
  66 dfsan_label dfsan_read_label(const void *addr, size_t size);
  67
  68 /// Retrieves a pointer to the dfsan_label_info struct for the given label.
  69 const struct dfsan_label_info *dfsan_get_label_info(dfsan_label label);
  70
  71 /// Returns whether the given label label contains the label elem.
  72 int dfsan_has_label(dfsan_label label, dfsan_label elem);
  73
  74 /// If the given label label contains a label with the description desc, returns
  75 /// that label, else returns 0.
  76 dfsan_label dfsan_has_label_with_desc(dfsan_label label, const char *desc);
  77
  78 /// Returns the number of labels allocated.
  79 size_t dfsan_get_label_count(void);
  80
  81 /// Sets a callback to be invoked on calls to write().  The callback is invoked
  82 /// before the write is done.  The write is not guaranteed to succeed when the
  83 /// callback executes.  Pass in NULL to remove any callback.
  84 void dfsan_set_write_callback(dfsan_write_callback_t labeled_write_callback);
  85
  86 /// Writes the labels currently used by the program to the given file
  87 /// descriptor. The lines of the output have the following format:
  88 ///
  89 /// <label> <parent label 1> <parent label 2> <label description if any>
  90 void dfsan_dump_labels(int fd);
  91
  92 /// Interceptor hooks.
  93 /// Whenever a dfsan's custom function is called the corresponding
  94 /// hook is called it non-zero. The hooks should be defined by the user.
  95 /// The primary use case is taint-guided fuzzing, where the fuzzer
  96 /// needs to see the parameters of the function and the labels.
  97 /// FIXME: implement more hooks.
  98 void dfsan_weak_hook_memcmp(void *caller_pc, const void *s1, const void *s2,
  99                             size_t n, dfsan_label s1_label,
 100                             dfsan_label s2_label, dfsan_label n_label);
 101 void dfsan_weak_hook_strncmp(void *caller_pc, const char *s1, const char *s2,
 102                              size_t n, dfsan_label s1_label,
 103                              dfsan_label s2_label, dfsan_label n_label);
 104 #ifdef __cplusplus
 105 }  // extern "C"
 106
 107 template <typename T>
 108 void dfsan_set_label(dfsan_label label, T &data) {  // NOLINT
 109   dfsan_set_label(label, (void *)&data, sizeof(T));
 110 }
 111
 112 #endif
 113
 114 #endif  // DFSAN_INTERFACE_H