Security/libsecurity_apple_file_dl/doc/FORMAT

   1 Some notes of the format of DL files:
   2
   3
   4
   5 DL file format:
   6
   7 All offsets are relative to the start of the section they are in.
   8 All fileds are uint32 (4 bytes) unless otherwise specified.  All other fields are aligned on 4 bytes boundries.
   9
  10 Header Section
  11         Magic
  12         File Format Version Number
  13         Auth Section Offset
  14         Schema Section Offset
  15
  16 Auth Section
  17         Auth Info Size
  18         Auth Info Data
  19
  20 Schema Section                                  # This section is always read entirely into memory
  21         Schema Section Size (uint32)
  22         Tables
  23                 Table Count (uint32)
  24                 Table Offset 0                  # Relative to start of Schema Section
  25                 Table Offset 1
  26                 ...
  27                 Table Offset N
  28
  29 # Information about parsing modules is read directly from the meta tables
  30 Table Section
  31         Table Section Size
  32         Table ID (uint32)
  33         Records Count                           # Number of Records in record section.
  34         Record 0 Offset                         # Relative to start of Table Section.
  35         Index SubSection Offset         # Relative to start of Table Section
  36         Head of Free List                       # Table Section relative first free
  37                                                                 # recordNumber slot (with bit 0 set)
  38                                                                 # Or 0 if there are no free records
  39         Record Number Count                     # Start of range of unused record numbers
  40         Record 0 offset                         # Relative to start of Table Section.
  41         Record 1 offset
  42         Record 2 freelist                       # If Bit zero is set this is Table Section
  43                                                                 # relative offset to next free recordNumber
  44                                                                 # 0 indicates the last free record slot.
  45         ...
  46         Record n offset
  47         Record
  48                 Record Size                     # Rounded up to nearest mulitple of 4
  49                 Record Number
  50                 Creation File Version
  51                 Record Version
  52                 Data Size
  53                 SemanticInformation
  54                 Attribute 0 Offset
  55                 Attribute 1 Offset
  56                 Attribute 2 Offset
  57                 ...
  58                 Attribute m Offset
  59                 Data
  60                         Data
  61                 Attribute 0
  62                         Size
  63                         Data
  64                 Attribute 1
  65                         Value
  66                 ...
  67                 Attribute m
  68                         Value Count
  69                                 Value 0
  70                                 Value 1
  71                                 ...
  72                                 Value p
  73         Record
  74         ...
  75         Record
  76         Index SubSection
  77                 Index SubSection Size
  78                 Index TOC                       # This is part of the Schema
  79                         Record Type
  80                         Attribute Type
  81                         Index Offset
  82                 Index 1
  83                         Index Size
  84                         Index Offsets
  85                                 Index Offset Count
  86                                 Index Data 1 Offset
  87                                 Index Data 2 Offset
  88                                 ...
  89                                 Index Data m OFFSET
  90                         Index Data
  91                                 Index Data 1
  92                                         Record Offset
  93                                         Attribute Size
  94                                         Attribute Data
  95                                 Index Data 2
  96                                 ...
  97                                 Index Data N
  98                 Index 2
  99                 ...
 100                 Index n
 101
 102 Version Section         # Maintained by AtomicFile code
 103         4 byte version number
 104
 105 old Schema Section                              # This section is always read entirely into memory
 106         Schema Section Size (uint32)
 107         Releations
 108                 Relation Count (uint32)
 109         Relation
 110             Relation ID (uint32)
 111             Record Section Offset
 112             Relation Name Size
 113             Relation Name Data
 114                         Attributes
 115                 Attribute Count (uint32)
 116                 Attribute
 117                     Releation ID (uint32)
 118                     Attribute ID (uint32)
 119                     Attribute Format (uint32)
 120                     Attribute Name Format (uint32)
 121                     Attribute Name Size
 122                     Attribute Name Data
 123                     Attribute Name ID Size
 124                     Attribute Name ID Data
 125                     ParsingModule
 126                         Parsion Module Present (bool)
 127                         Module ID (GUID)
 128                         SSID (uint32)
 129                         SubService Type (uint32)
 130                         Addin Version Major (uint32)
 131                         Addin Version Minor (uint32)
 132                 Attribute
 133                 ...
 134                 Attribute
 135             Indexes
 136                 Index Count (uint32)
 137                 Index
 138                     Relation ID (uint32)
 139                     Index ID (uint32)
 140                     Index Type (uint32)
 141                     Indexed Data Location (uint32)
 142                     Index Attribute Count (uint32)
 143                         Attribute ID (uint32)
 144                         Attribute ID (uint32)
 145                         ...
 146                         Attribute ID (uint32)
 147                 Index
 148                 ...
 149                 Index
 150         Relation
 151         ...
 152         Relation
 153