[Forensics-changes] [yara] 114/135: Handle zero-length files as normal files and remove zero-length errors.

[Hilko Bengen]

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bengen pushed a commit to annotated tag v3.1.0
in repository yara.

commit 75139e2fb4f1a025ac2d41c24d6cd5c0964317f5
Author: Victor M. Alvarez <plusvic at gmail.com>
Date:   Fri Aug 22 12:34:09 2014 +0200

    Handle zero-length files as normal files and remove zero-length errors.
---
 libyara/filemap.c            | 103 +++++++++++++++++++++++--------------------
 libyara/include/yara/error.h |   1 -
 yara-python/yara-python.c    |   5 ---
 yara.c                       |   3 --
 4 files changed, 56 insertions(+), 56 deletions(-)

diff --git a/libyara/filemap.c b/libyara/filemap.c
index 5b6cbd7..a532460 100755
--- a/libyara/filemap.c
+++ b/libyara/filemap.c
@@ -69,38 +69,40 @@ int yr_filemap_map(
     return ERROR_COULD_NOT_OPEN_FILE;
   }
 
-  if (pmapped_file->size == 0)
+  if (pmapped_file->size != 0)
   {
-    CloseHandle(pmapped_file->file);
-    return ERROR_ZERO_LENGTH_FILE;
-  }
-
-  pmapped_file->mapping = CreateFileMapping(
-      pmapped_file->file,
-      NULL,
-      PAGE_READONLY,
-      0,
-      0,
-      NULL);
-
-  if (pmapped_file->mapping == NULL)
-  {
-    CloseHandle(pmapped_file->file);
-    return ERROR_COULD_NOT_MAP_FILE;
+    pmapped_file->mapping = CreateFileMapping(
+        pmapped_file->file,
+        NULL,
+        PAGE_READONLY,
+        0,
+        0,
+        NULL);
+
+    if (pmapped_file->mapping == NULL)
+    {
+      CloseHandle(pmapped_file->file);
+      return ERROR_COULD_NOT_MAP_FILE;
+    }
+
+    pmapped_file->data = (uint8_t*) MapViewOfFile(
+        pmapped_file->mapping,
+        FILE_MAP_READ,
+        0,
+        0,
+        0);
+
+    if (pmapped_file->data == NULL)
+    {
+      CloseHandle(pmapped_file->mapping);
+      CloseHandle(pmapped_file->file);
+      return ERROR_COULD_NOT_MAP_FILE;
+    }
   }
-
-  pmapped_file->data = (uint8_t*) MapViewOfFile(
-      pmapped_file->mapping,
-      FILE_MAP_READ,
-      0,
-      0,
-      0);
-
-  if (pmapped_file->data == NULL)
+  else
   {
-    CloseHandle(pmapped_file->mapping);
-    CloseHandle(pmapped_file->file);
-    return ERROR_COULD_NOT_MAP_FILE;
+    pmapped_file->mapping = NULL;
+    pmapped_file->data = NULL;
   }
 
   return ERROR_SUCCESS;
@@ -109,8 +111,12 @@ int yr_filemap_map(
 void yr_filemap_unmap(
     YR_MAPPED_FILE* pmapped_file)
 {
-  UnmapViewOfFile(pmapped_file->data);
-  CloseHandle(pmapped_file->mapping);
+  if (pmapped_file->data != NULL)
+    UnmapViewOfFile(pmapped_file->data);
+
+  if (pmapped_file->mapping != NULL)
+    CloseHandle(pmapped_file->mapping);
+
   CloseHandle(pmapped_file->file);
 }
 
@@ -139,24 +145,25 @@ int yr_filemap_map(
 
   pmapped_file->size = fstat.st_size;
 
-  if (pmapped_file->size == 0)
+  if (pmapped_file->size != 0)
   {
-    close(pmapped_file->file);
-    return ERROR_ZERO_LENGTH_FILE;
+    pmapped_file->data = (uint8_t*) mmap(
+        0,
+        pmapped_file->size,
+        PROT_READ,
+        MAP_PRIVATE,
+        pmapped_file->file,
+        0);
+
+    if (pmapped_file->data == MAP_FAILED)
+    {
+      close(pmapped_file->file);
+      return ERROR_COULD_NOT_MAP_FILE;
+    }
   }
-
-  pmapped_file->data = (uint8_t*) mmap(
-      0,
-      pmapped_file->size,
-      PROT_READ,
-      MAP_PRIVATE,
-      pmapped_file->file,
-      0);
-
-  if (pmapped_file->data == MAP_FAILED)
+  else
   {
-    close(pmapped_file->file);
-    return ERROR_COULD_NOT_MAP_FILE;
+    pmapped_file->data = NULL;
   }
 
   return ERROR_SUCCESS;
@@ -165,7 +172,9 @@ int yr_filemap_map(
 void yr_filemap_unmap(
     YR_MAPPED_FILE* pmapped_file)
 {
-  munmap(pmapped_file->data, pmapped_file->size);
+  if (pmapped_file->data != NULL)
+    munmap(pmapped_file->data, pmapped_file->size);
+
   close(pmapped_file->file);
 }
 
diff --git a/libyara/include/yara/error.h b/libyara/include/yara/error.h
index d66d17a..6a8d343 100644
--- a/libyara/include/yara/error.h
+++ b/libyara/include/yara/error.h
@@ -25,7 +25,6 @@ limitations under the License.
 #define ERROR_COULD_NOT_ATTACH_TO_PROCESS       2
 #define ERROR_COULD_NOT_OPEN_FILE               3
 #define ERROR_COULD_NOT_MAP_FILE                4
-#define ERROR_ZERO_LENGTH_FILE                  5
 #define ERROR_INVALID_FILE                      6
 #define ERROR_CORRUPT_FILE                      7
 #define ERROR_UNSUPPORTED_FILE_VERSION          8
diff --git a/yara-python/yara-python.c b/yara-python/yara-python.c
index 74e288f..a7a784e 100644
--- a/yara-python/yara-python.c
+++ b/yara-python/yara-python.c
@@ -624,11 +624,6 @@ PyObject* handle_error(
           YaraError,
           "could not map file \"%s\" into memory",
           extra);
-    case ERROR_ZERO_LENGTH_FILE:
-      return PyErr_Format(
-          YaraError,
-          "zero length file \"%s\"",
-          extra);
     case ERROR_INVALID_FILE:
       return PyErr_Format(
           YaraError,
diff --git a/yara.c b/yara.c
index 79519da..546bdc0 100644
--- a/yara.c
+++ b/yara.c
@@ -410,9 +410,6 @@ void print_scanner_error(int error)
     case ERROR_COULD_NOT_OPEN_FILE:
       fprintf(stderr, "could not open file\n");
       break;
-    case ERROR_ZERO_LENGTH_FILE:
-      fprintf(stderr, "zero length file\n");
-      break;
     case ERROR_UNSUPPORTED_FILE_VERSION:
       fprintf(stderr, "rules were compiled with a newer version of YARA.\n");
       break;

-- 
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