PhotoRec: recover Magic Lantern Video .mlv file

src/Makefile.am

@@ -178,6 +178,7 @@ file_C			= filegen.c \
 			  file_mig.c \
 			  file_mk5.c \
 			  file_mkv.c \
+			  file_mlv.c \
 			  file_mobi.c \
 			  file_mov.c \
 			  file_mp3.c \

src/file_list.c

@@ -180,6 +180,7 @@ extern const file_hint_t file_hint_mid;
 extern const file_hint_t file_hint_mig;
 extern const file_hint_t file_hint_mk5;
 extern const file_hint_t file_hint_mkv;
+extern const file_hint_t file_hint_mlv;
 extern const file_hint_t file_hint_mobi;
 extern const file_hint_t file_hint_mov;
 extern const file_hint_t file_hint_mp3;
@@ -455,6 +456,7 @@ file_enable_t list_file_enable[]=
   { .enable=0, .file_hint=&file_hint_mig  },
   { .enable=0, .file_hint=&file_hint_mk5  },
   { .enable=0, .file_hint=&file_hint_mkv  },
+  { .enable=0, .file_hint=&file_hint_mlv  },
   { .enable=0, .file_hint=&file_hint_mobi },
   { .enable=0, .file_hint=&file_hint_mov  },
   { .enable=0, .file_hint=&file_hint_mp3  },

src/file_mlv.c

@@ -0,0 +1,134 @@
+/*
+
+    File: file_mlv.c
+
+    Copyright (C) 2014 Christophe GRENIER <grenier@cgsecurity.org>
+  
+    This software is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+  
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+  
+    You should have received a copy of the GNU General Public License along
+    with this program; if not, write the Free Software Foundation, Inc., 51
+    Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+
+ */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+#ifdef HAVE_STRING_H
+#include <string.h>
+#endif
+#include <stdio.h>
+#include "types.h"
+#include "filegen.h"
+#include "common.h"
+
+static void register_header_check_mlv(file_stat_t *file_stat);
+
+const file_hint_t file_hint_mlv= {
+  .extension="mlv",
+  .description="Magic Lantern Video",
+  .min_header_distance=0,
+  .max_filesize=PHOTOREC_MAX_FILE_SIZE,
+  .recover=1,
+  .enable_by_default=1,
+  .register_header_check=&register_header_check_mlv
+};
+
+/* See https://bitbucket.org/hudson/magic-lantern/src/tip/modules/mlv_rec/mlv.h?at=unified */
+typedef struct {
+  uint8_t     fileMagic[4];	/* Magic Lantern Video file header */
+  uint32_t    blockSize;	/* size of the whole header */
+  uint8_t     versionString[8];	/* null-terminated C-string of the exact revision of this format */
+  uint64_t    fileGuid;		/* UID of the file (group) generated using hw counter, time of day and PRNG */
+  uint16_t    fileNum;		/* the ID within fileCount this file has (0 to fileCount-1) */
+  uint16_t    fileCount;	/* how many files belong to this group (splitting or parallel) */
+  uint32_t    fileFlags;	/* 1=out-of-order data, 2=dropped frames, 4=single image mode, 8=stopped due to error */
+  uint16_t    videoClass;	/* 0=none, 1=RAW, 2=YUV, 3=JPEG, 4=H.264 */
+  uint16_t    audioClass;	/* 0=none, 1=WAV */
+  uint32_t    videoFrameCount;	/* number of video frames in this file. set to 0 on start, updated when finished. */
+  uint32_t    audioFrameCount;	/* number of audio frames in this file. set to 0 on start, updated when finished. */
+  uint32_t    sourceFpsNom;	/* configured fps in 1/s multiplied by sourceFpsDenom */
+  uint32_t    sourceFpsDenom;	/* denominator for fps. usually set to 1000, but may be 1001 for NTSC */
+} __attribute__ ((__packed__)) mlv_file_hdr_t;
+
+typedef struct {
+  uint8_t     blockType[4];
+  uint32_t    blockSize;
+  uint64_t    timestamp;
+} __attribute__ ((__packed__)) mlv_hdr_t;
+
+static int is_valid_type(const mlv_hdr_t *hdr)
+{
+  unsigned int i;
+  for(i=0; i<4; i++)
+  {
+    const uint8_t c=hdr->blockType[i];
+    if(!((c>='0' && c<='9') || (c>='a' && c<='z') || (c>='A' && c<='Z')))
+      return 0;
+  }
+  return 1;
+}
+
+static data_check_t data_check_mlv(const unsigned char *buffer, const unsigned int buffer_size, file_recovery_t *fr)
+{
+  while(fr->calculated_file_size + buffer_size/2  >= fr->file_size &&
+      fr->calculated_file_size + 8 < fr->file_size + buffer_size/2)
+  {
+    const unsigned int i=fr->calculated_file_size - fr->file_size + buffer_size/2;
+    const mlv_hdr_t *hdr=(const mlv_hdr_t *)&buffer[i];
+    if(le32(hdr->blockSize)<0x10 || !is_valid_type(hdr))
+      return DC_STOP;
+    fr->calculated_file_size+=le32(hdr->blockSize);
+  }
+  return DC_CONTINUE;
+}
+
+static void file_check_mlv(file_recovery_t *file_recovery)
+{
+  mlv_hdr_t hdr;
+  uint64_t fs=0;
+  do
+  {
+    if( fseek(file_recovery->handle, fs, SEEK_SET)<0 ||
+	fread(&hdr, sizeof(hdr), 1, file_recovery->handle)!=1 ||
+	le32(hdr.blockSize)<0x10 ||
+	!is_valid_type(&hdr) ||
+	fs + le32(hdr.blockSize) > file_recovery->file_size)
+    {
+      file_recovery->file_size=fs;
+      return;
+    }
+    fs+=le32(hdr.blockSize);
+  } while(1);
+}
+
+static int header_check_mlv(const unsigned char *buffer, const unsigned int buffer_size, const unsigned int safe_header_only, const file_recovery_t *file_recovery, file_recovery_t *file_recovery_new)
+{
+  const mlv_file_hdr_t *hdr=(const mlv_file_hdr_t *)buffer;
+  if(le32(hdr->blockSize) < 0x34)
+    return 0;
+  if(le16(hdr->fileNum) > le16(hdr->fileCount))
+    return 0;
+  if(le16(hdr->fileNum) >= le16(hdr->fileCount) && le16(hdr->fileCount)>0)
+    return 0;
+  reset_file_recovery(file_recovery_new);
+  file_recovery_new->extension=file_hint_mlv.extension;
+  file_recovery_new->file_check=&file_check_mlv;
+  if(file_recovery_new->blocksize > 0x10)
+    file_recovery_new->data_check=&data_check_mlv;
+  return 1;
+}
+
+static void register_header_check_mlv(file_stat_t *file_stat)
+{
+  register_header_check(0, "MLVI", 4, &header_check_mlv, file_stat);
+}