custom mutators might work again like this

2 files changed, 100 insertions, 50 deletions

diff --git a/examples/custom_mutators/custom_mutator_helpers.h b/examples/custom_mutators/custom_mutator_helpers.h
index 53ecf960..844ccf94 100644
--- a/examples/custom_mutators/custom_mutator_helpers.h
+++ b/examples/custom_mutators/custom_mutator_helpers.h
@@ -5,7 +5,9 @@
 #include "types.h"
 #include <stdlib.h>
 
-#define LIMIT_RAND(limit) (rand() % (limit))
+#define RAND_BELOW(limit) (rand() % (limit))
+
+typedef struct{} afl_t;
 
 static void surgical_havoc_mutate(u8 *out_buf, s32 begin, s32 end) {
 
@@ -13,13 +15,13 @@ static void surgical_havoc_mutate(u8 *out_buf, s32 begin, s32 end) {
   static s16 interesting_16[] = {INTERESTING_8, INTERESTING_16};
   static s32 interesting_32[] = {INTERESTING_8, INTERESTING_16, INTERESTING_32};
 
-  switch (LIMIT_RAND(12)) {
+  switch (RAND_BELOW(12)) {
 
     case 0: {
 
       /* Flip a single bit somewhere. Spooky! */
 
-      s32 bit_idx = ((LIMIT_RAND(end - begin) + begin) << 3) + LIMIT_RAND(8);
+      s32 bit_idx = ((RAND_BELOW(end - begin) + begin) << 3) + RAND_BELOW(8);
 
       out_buf[bit_idx >> 3] ^= 128 >> (bit_idx & 7);
 
@@ -31,8 +33,8 @@ static void surgical_havoc_mutate(u8 *out_buf, s32 begin, s32 end) {
 
       /* Set byte to interesting value. */
 
-      u8 val = interesting_8[LIMIT_RAND(sizeof(interesting_8))];
-      out_buf[(LIMIT_RAND(end - begin) + begin)] = val;
+      u8 val = interesting_8[RAND_BELOW(sizeof(interesting_8))];
+      out_buf[(RAND_BELOW(end - begin) + begin)] = val;
 
       break;
 
@@ -44,19 +46,19 @@ static void surgical_havoc_mutate(u8 *out_buf, s32 begin, s32 end) {
 
       if (end - begin < 2) break;
 
-      s32 byte_idx = (LIMIT_RAND(end - begin) + begin);
+      s32 byte_idx = (RAND_BELOW(end - begin) + begin);
 
       if (byte_idx >= end - 1) break;
 
-      switch (LIMIT_RAND(2)) {
+      switch (RAND_BELOW(2)) {
 
         case 0:
           *(u16 *)(out_buf + byte_idx) =
-              interesting_16[LIMIT_RAND(sizeof(interesting_16) >> 1)];
+              interesting_16[RAND_BELOW(sizeof(interesting_16) >> 1)];
           break;
         case 1:
           *(u16 *)(out_buf + byte_idx) =
-              SWAP16(interesting_16[LIMIT_RAND(sizeof(interesting_16) >> 1)]);
+              SWAP16(interesting_16[RAND_BELOW(sizeof(interesting_16) >> 1)]);
           break;
 
       }
@@ -71,19 +73,19 @@ static void surgical_havoc_mutate(u8 *out_buf, s32 begin, s32 end) {
 
       if (end - begin < 4) break;
 
-      s32 byte_idx = (LIMIT_RAND(end - begin) + begin);
+      s32 byte_idx = (RAND_BELOW(end - begin) + begin);
 
       if (byte_idx >= end - 3) break;
 
-      switch (LIMIT_RAND(2)) {
+      switch (RAND_BELOW(2)) {
 
         case 0:
           *(u32 *)(out_buf + byte_idx) =
-              interesting_32[LIMIT_RAND(sizeof(interesting_32) >> 2)];
+              interesting_32[RAND_BELOW(sizeof(interesting_32) >> 2)];
           break;
         case 1:
           *(u32 *)(out_buf + byte_idx) =
-              SWAP32(interesting_32[LIMIT_RAND(sizeof(interesting_32) >> 2)]);
+              SWAP32(interesting_32[RAND_BELOW(sizeof(interesting_32) >> 2)]);
           break;
 
       }
@@ -98,19 +100,19 @@ static void surgical_havoc_mutate(u8 *out_buf, s32 begin, s32 end) {
 
       if (end - begin < 8) break;
 
-      s32 byte_idx = (LIMIT_RAND(end - begin) + begin);
+      s32 byte_idx = (RAND_BELOW(end - begin) + begin);
 
       if (byte_idx >= end - 7) break;
 
-      switch (LIMIT_RAND(2)) {
+      switch (RAND_BELOW(2)) {
 
         case 0:
           *(u64 *)(out_buf + byte_idx) =
-              (s64)interesting_32[LIMIT_RAND(sizeof(interesting_32) >> 2)];
+              (s64)interesting_32[RAND_BELOW(sizeof(interesting_32) >> 2)];
           break;
         case 1:
           *(u64 *)(out_buf + byte_idx) =
-              SWAP64((s64)interesting_32[LIMIT_RAND(sizeof(interesting_32) >> 2)]);
+              SWAP64((s64)interesting_32[RAND_BELOW(sizeof(interesting_32) >> 2)]);
           break;
 
       }
@@ -123,7 +125,7 @@ static void surgical_havoc_mutate(u8 *out_buf, s32 begin, s32 end) {
 
       /* Randomly subtract from byte. */
 
-      out_buf[(LIMIT_RAND(end - begin) + begin)] -= 1 + LIMIT_RAND(ARITH_MAX);
+      out_buf[(RAND_BELOW(end - begin) + begin)] -= 1 + RAND_BELOW(ARITH_MAX);
 
       break;
 
@@ -133,7 +135,7 @@ static void surgical_havoc_mutate(u8 *out_buf, s32 begin, s32 end) {
 
       /* Randomly add to byte. */
 
-      out_buf[(LIMIT_RAND(end - begin) + begin)] += 1 + LIMIT_RAND(ARITH_MAX);
+      out_buf[(RAND_BELOW(end - begin) + begin)] += 1 + RAND_BELOW(ARITH_MAX);
 
       break;
 
@@ -145,17 +147,17 @@ static void surgical_havoc_mutate(u8 *out_buf, s32 begin, s32 end) {
 
       if (end - begin < 2) break;
 
-      s32 byte_idx = (LIMIT_RAND(end - begin) + begin);
+      s32 byte_idx = (RAND_BELOW(end - begin) + begin);
 
       if (byte_idx >= end - 1) break;
 
-      if (LIMIT_RAND(2)) {
+      if (RAND_BELOW(2)) {
 
-        *(u16 *)(out_buf + byte_idx) -= 1 + LIMIT_RAND(ARITH_MAX);
+        *(u16 *)(out_buf + byte_idx) -= 1 + RAND_BELOW(ARITH_MAX);
 
       } else {
 
-        u16 num = 1 + LIMIT_RAND(ARITH_MAX);
+        u16 num = 1 + RAND_BELOW(ARITH_MAX);
 
         *(u16 *)(out_buf + byte_idx) =
             SWAP16(SWAP16(*(u16 *)(out_buf + byte_idx)) - num);
@@ -172,17 +174,17 @@ static void surgical_havoc_mutate(u8 *out_buf, s32 begin, s32 end) {
 
       if (end - begin < 2) break;
 
-      s32 byte_idx = (LIMIT_RAND(end - begin) + begin);
+      s32 byte_idx = (RAND_BELOW(end - begin) + begin);
 
       if (byte_idx >= end - 1) break;
 
-      if (LIMIT_RAND(2)) {
+      if (RAND_BELOW(2)) {
 
-        *(u16 *)(out_buf + byte_idx) += 1 + LIMIT_RAND(ARITH_MAX);
+        *(u16 *)(out_buf + byte_idx) += 1 + RAND_BELOW(ARITH_MAX);
 
       } else {
 
-        u16 num = 1 + LIMIT_RAND(ARITH_MAX);
+        u16 num = 1 + RAND_BELOW(ARITH_MAX);
 
         *(u16 *)(out_buf + byte_idx) =
             SWAP16(SWAP16(*(u16 *)(out_buf + byte_idx)) + num);
@@ -199,17 +201,17 @@ static void surgical_havoc_mutate(u8 *out_buf, s32 begin, s32 end) {
 
       if (end - begin < 4) break;
 
-      s32 byte_idx = (LIMIT_RAND(end - begin) + begin);
+      s32 byte_idx = (RAND_BELOW(end - begin) + begin);
 
       if (byte_idx >= end - 3) break;
 
-      if (LIMIT_RAND(2)) {
+      if (RAND_BELOW(2)) {
 
-        *(u32 *)(out_buf + byte_idx) -= 1 + LIMIT_RAND(ARITH_MAX);
+        *(u32 *)(out_buf + byte_idx) -= 1 + RAND_BELOW(ARITH_MAX);
 
       } else {
 
-        u32 num = 1 + LIMIT_RAND(ARITH_MAX);
+        u32 num = 1 + RAND_BELOW(ARITH_MAX);
 
         *(u32 *)(out_buf + byte_idx) =
             SWAP32(SWAP32(*(u32 *)(out_buf + byte_idx)) - num);
@@ -226,17 +228,17 @@ static void surgical_havoc_mutate(u8 *out_buf, s32 begin, s32 end) {
 
       if (end - begin < 4) break;
 
-      s32 byte_idx = (LIMIT_RAND(end - begin) + begin);
+      s32 byte_idx = (RAND_BELOW(end - begin) + begin);
 
       if (byte_idx >= end - 3) break;
 
-      if (LIMIT_RAND(2)) {
+      if (RAND_BELOW(2)) {
 
-        *(u32 *)(out_buf + byte_idx) += 1 + LIMIT_RAND(ARITH_MAX);
+        *(u32 *)(out_buf + byte_idx) += 1 + RAND_BELOW(ARITH_MAX);
 
       } else {
 
-        u32 num = 1 + LIMIT_RAND(ARITH_MAX);
+        u32 num = 1 + RAND_BELOW(ARITH_MAX);
 
         *(u32 *)(out_buf + byte_idx) =
             SWAP32(SWAP32(*(u32 *)(out_buf + byte_idx)) + num);
@@ -253,7 +255,7 @@ static void surgical_havoc_mutate(u8 *out_buf, s32 begin, s32 end) {
          why not. We use XOR with 1-255 to eliminate the
          possibility of a no-op. */
 
-      out_buf[(LIMIT_RAND(end - begin) + begin)] ^= 1 + LIMIT_RAND(255);
+      out_buf[(RAND_BELOW(end - begin) + begin)] ^= 1 + RAND_BELOW(255);
 
       break;
 
diff --git a/examples/custom_mutators/example.c b/examples/custom_mutators/example.c
index 2787e218..560a5919 100644
--- a/examples/custom_mutators/example.c
+++ b/examples/custom_mutators/example.c
@@ -3,6 +3,7 @@
   Written by Khaled Yakdan <yakdan@code-intelligence.de>
              Andrea Fioraldi <andreafioraldi@gmail.com>
              Shengtuo Hu <h1994st@gmail.com>
+             Dominik Maier <mail@dmnk.co>
 */
 
 // You need to use -I /path/to/AFLplusplus/include
@@ -12,6 +13,8 @@
 #include <stdlib.h>
 #include <string.h>
 
+#define DATA_SIZE (100)
+
 static const char *commands[] = {
 
     "GET",
@@ -20,12 +23,36 @@ static const char *commands[] = {
 
 };
 
-static size_t data_size = 100;
 
-void afl_custom_init(unsigned int seed) {
+typedef struct my_mutator {
+
+  afl_t *afl;
+  // any additional data here!
+
+} my_mutator_t;
+
+/**
+ * Initialize this custom mutator
+ *
+ * @param[in] afl a pointer to the internal state object. Can be ignored for now.
+ * @param[in] seed A seed for this mutator - the same seed should always mutate in the same way.
+ * @return Pointer to the data object this custom mutator instance should use.
+ *         There may be multiple instances of this mutator in one afl-fuzz run!
+ *         Returns NULL on error.
+ */
+my_mutator_t *afl_custom_init(afl_t *afl, unsigned int seed) {
 
   srand(seed); // needed also by surgical_havoc_mutate()
 
+  my_mutator_t *data = calloc(1, sizeof(my_mutator_t));
+  if (!data) {
+    perror("afl_custom_init alloc");
+    return NULL;
+  }
+  data->afl = afl;
+
+  return data;
+
 }
 
 /**
@@ -33,6 +60,7 @@ void afl_custom_init(unsigned int seed) {
  *
  * (Optional for now. Required in the future)
  *
+ * @param[in] data pointer returned in afl_custom_init for this fuzz case
  * @param[in] buf Pointer to input data to be mutated
  * @param[in] buf_size Size of input data
  * @param[in] add_buf Buffer containing the additional test case
@@ -41,13 +69,14 @@ void afl_custom_init(unsigned int seed) {
  *     produce data larger than max_size.
  * @return Size of the mutated output.
  */
-size_t afl_custom_fuzz(uint8_t **buf, size_t buf_size, uint8_t *add_buf,
+size_t afl_custom_fuzz(my_mutator_t *data, uint8_t **buf, size_t buf_size,
+                       uint8_t *add_buf,
                        size_t add_buf_size,  // add_buf can be NULL
                        size_t max_size) {
 
   // Make sure that the packet size does not exceed the maximum size expected by
   // the fuzzer
-  size_t mutated_size = data_size <= max_size ? data_size : max_size;
+  size_t mutated_size = DATA_SIZE <= max_size ? DATA_SIZE : max_size;
 
   if (mutated_size > buf_size) *buf = realloc(*buf, mutated_size);
 
@@ -59,10 +88,10 @@ size_t afl_custom_fuzz(uint8_t **buf, size_t buf_size, uint8_t *add_buf,
   // Mutate the payload of the packet
   int i;
   for (i = 0; i < 8; ++i) {
-  
+
     // Randomly perform one of the (no len modification) havoc mutations
     surgical_havoc_mutate(mutated_out, 3, mutated_size);
-  
+
   }
 
   return mutated_size;
@@ -76,6 +105,7 @@ size_t afl_custom_fuzz(uint8_t **buf, size_t buf_size, uint8_t *add_buf,
  * (Optional) If this functionality is not needed, simply don't define this
  * function.
  *
+ * @param[in] data pointer returned in afl_custom_init for this fuzz case
  * @param[in] buf Buffer containing the test case to be executed
  * @param[in] buf_size Size of the test case
  * @param[out] out_buf Pointer to the buffer containing the test case after
@@ -83,7 +113,7 @@ size_t afl_custom_fuzz(uint8_t **buf, size_t buf_size, uint8_t *add_buf,
  *     will release the memory after saving the test case.
  * @return Size of the output buffer after processing
  */
-size_t afl_custom_pre_save(uint8_t *buf, size_t buf_size, uint8_t **out_buf) {
+size_t afl_custom_pre_save(my_mutator_t *data, uint8_t *buf, size_t buf_size, uint8_t **out_buf) {
 
   size_t out_buf_size;
 
@@ -118,11 +148,12 @@ static int      cur_step;
  *
  * (Optional)
  *
+ * @param data pointer returned in afl_custom_init for this fuzz case
  * @param buf Buffer containing the test case
  * @param buf_size Size of the test case
  * @return The amount of possible iteration steps to trim the input
  */
-int afl_custom_init_trim(uint8_t *buf, size_t buf_size) {
+int afl_custom_init_trim(my_mutator_t *data, uint8_t *buf, size_t buf_size) {
 
   // We simply trim once
   trimmming_steps = 1;
@@ -146,12 +177,13 @@ int afl_custom_init_trim(uint8_t *buf, size_t buf_size) {
  *
  * (Optional)
  *
+ * @param[in] data pointer returned in afl_custom_init for this fuzz case
  * @param[out] out_buf Pointer to the buffer containing the trimmed test case.
  *     External library should allocate memory for out_buf. AFL++ will release
  *     the memory after saving the test case.
  * @param[out] out_buf_size Pointer to the size of the trimmed test case
  */
-void afl_custom_trim(uint8_t **out_buf, size_t *out_buf_size) {
+void afl_custom_trim(my_mutator_t *data, uint8_t **out_buf, size_t *out_buf_size) {
 
   *out_buf_size = trim_buf_size - 1;
 
@@ -169,11 +201,12 @@ void afl_custom_trim(uint8_t **out_buf, size_t *out_buf_size) {
  *
  * (Optional)
  *
+ * @param[in] data pointer returned in afl_custom_init for this fuzz case
  * @param success Indicates if the last trim operation was successful.
  * @return The next trim iteration index (from 0 to the maximum amount of
  *     steps returned in init_trim)
  */
-int afl_custom_post_trim(int success) {
+int afl_custom_post_trim(my_mutator_t *data, int success) {
 
   if (success) {
 
@@ -192,6 +225,7 @@ int afl_custom_post_trim(int success) {
  *
  * (Optional)
  *
+ * @param[in] data pointer returned in afl_custom_init for this fuzz case
  * @param[inout] buf Pointer to the input data to be mutated and the mutated
  *     output
  * @param[in] buf_size Size of input data
@@ -199,7 +233,7 @@ int afl_custom_post_trim(int success) {
  *     not produce data larger than max_size.
  * @return Size of the mutated output.
  */
-size_t afl_custom_havoc_mutation(uint8_t **buf, size_t buf_size,
+size_t afl_custom_havoc_mutation(my_mutator_t *data, uint8_t **buf, size_t buf_size,
                                  size_t max_size) {
 
   if (buf_size == 0) {
@@ -223,9 +257,10 @@ size_t afl_custom_havoc_mutation(uint8_t **buf, size_t buf_size,
  *
  * (Optional)
  *
+ * @param[in] data pointer returned in afl_custom_init for this fuzz case
  * @return The probability (0-100).
  */
-uint8_t afl_custom_havoc_mutation_probability(void) {
+uint8_t afl_custom_havoc_mutation_probability(my_mutator_t *data) {
 
   return 5;  // 5 %
 
@@ -236,11 +271,12 @@ uint8_t afl_custom_havoc_mutation_probability(void) {
  *
  * (Optional)
  *
+ * @param[in] data pointer returned in afl_custom_init for this fuzz case
  * @param filename File name of the test case in the queue entry
  * @return Return True(1) if the fuzzer will fuzz the queue entry, and
  *     False(0) otherwise.
  */
-uint8_t afl_custom_queue_get(const uint8_t *filename) {
+uint8_t afl_custom_queue_get(my_mutator_t *data, const uint8_t *filename) {
 
   return 1;
 
@@ -252,13 +288,25 @@ uint8_t afl_custom_queue_get(const uint8_t *filename) {
  *
  * (Optional)
  *
+ * @param data pointer returned in afl_custom_init for this fuzz case
  * @param filename_new_queue File name of the new queue entry
  * @param filename_orig_queue File name of the original queue entry
  */
-void afl_custom_queue_new_entry(const uint8_t *filename_new_queue,
+void afl_custom_queue_new_entry(my_mutator_t *data, const uint8_t *filename_new_queue,
                                 const uint8_t *filename_orig_queue) {
 
   /* Additional analysis on the original or new test case */
 
 }
 
+/**
+ * Deinitialize everything
+ *
+ * @param data The data ptr from afl_custom_init
+ */
+void afl_custom_deinit(my_mutator_t *data) {
+
+  free(data);
+
+}
+