lib/diskrep.cpp

   1 /*
   2  * Copyright (c) 2006-2007 Apple Inc. All Rights Reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. Please obtain a copy of the License at
  10  * http://www.opensource.apple.com/apsl/ and read it before using this
  11  * file.
  12  *
  13  * The Original Code and all software distributed under the License are
  14  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  15  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  16  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
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  18  * Please see the License for the specific language governing rights and
  19  * limitations under the License.
  20  *
  21  * @APPLE_LICENSE_HEADER_END@
  22  */
  23
  24 //
  25 // diskrep - disk representations of code
  26 //
  27 #include "diskrep.h"
  28 #include <sys/stat.h>
  29 #include <CoreFoundation/CFBundlePriv.h>
  30
  31 // specific disk representations created by the bestGuess() function
  32 #include "filediskrep.h"
  33 #include "bundlediskrep.h"
  34 #include "cfmdiskrep.h"
  35 #include "foreigndiskrep.h"
  36
  37
  38 namespace Security {
  39 namespace CodeSigning {
  40
  41 using namespace UnixPlusPlus;
  42
  43
  44 //
  45 // Abstract features
  46 //
  47 DiskRep::DiskRep()
  48 {
  49 }
  50
  51 DiskRep::~DiskRep()
  52 { /* virtual */ }
  53
  54
  55 //
  56 // Normal DiskReps are their own base.
  57 //
  58 DiskRep *DiskRep::base()
  59 {
  60         return this;
  61 }
  62
  63
  64 //
  65 // By default, DiskReps are read-only.
  66 //
  67 DiskRep::Writer *DiskRep::writer()
  68 {
  69         MacOSError::throwMe(errSecCSBadObjectFormat);
  70 }
  71
  72
  73 //
  74 // Given a file system path, come up with the most likely correct
  75 // disk representation for what's there.
  76 // This is, strictly speaking, a heuristic that could be fooled - there's
  77 // no fool-proof rule for figuring this out. But we'd expect this to work
  78 // fine in ordinary use. If you happen to know what you're looking at
  79 // (say, a bundle), then just create the suitable subclass of DiskRep directly.
  80 // That's quite legal.
  81 //
  82 DiskRep *DiskRep::bestGuess(const char *path)
  83 {
  84     struct stat st;
  85     if (::stat(path, &st))
  86         UnixError::throwMe();
  87
  88         // if it's a directory, assume it's a bundle
  89     if ((st.st_mode & S_IFMT) == S_IFDIR)       // directory - assume bundle
  90                 return new BundleDiskRep(path);
  91
  92         // see if it's the main executable of a recognized bundle
  93         if (CFRef<CFURLRef> pathURL = makeCFURL(path))
  94                 if (CFRef<CFBundleRef> bundle = _CFBundleCreateWithExecutableURLIfLooksLikeBundle(NULL, pathURL))
  95                                 return new BundleDiskRep(bundle);
  96
  97         // follow the file choosing rules
  98         return bestFileGuess(path);
  99 }
 100
 101
 102 DiskRep *DiskRep::bestFileGuess(const char *path)
 103 {
 104         AutoFileDesc fd(path, O_RDONLY);
 105         if (MachORep::candidiate(fd))
 106                 return new MachORep(path);
 107         if (CFMDiskRep::candidiate(fd))
 108                 return new CFMDiskRep(path);
 109         if (ForeignDiskRep::candidate(fd))
 110                 return new ForeignDiskRep(path);
 111
 112         return new FileDiskRep(path);
 113 }
 114
 115
 116 //
 117 // Default behaviors of DiskRep
 118 //
 119 string DiskRep::resourcesRootPath()
 120 {
 121         return "";              // has no resources directory
 122 }
 123
 124 CFDictionaryRef DiskRep::defaultResourceRules()
 125 {
 126         return NULL;    // none
 127 }
 128
 129 const Requirements *DiskRep::defaultRequirements(const Architecture *)
 130 {
 131         return NULL;    // none
 132 }
 133
 134 Universal *DiskRep::mainExecutableImage()
 135 {
 136         return NULL;    // no Mach-O executable
 137 }
 138
 139 size_t DiskRep::pageSize()
 140 {
 141         return monolithicPageSize;      // unpaged (monolithic)
 142 }
 143
 144 size_t DiskRep::signingBase()
 145 {
 146         return 0;               // whole file (start at beginning)
 147 }
 148
 149 CFArrayRef DiskRep::modifiedFiles()
 150 {
 151         // by default, claim (just) the main executable modified
 152         CFRef<CFURLRef> mainURL = makeCFURL(mainExecutablePath());
 153         return makeCFArray(1, mainURL.get());
 154 }
 155
 156 void DiskRep::flush()
 157 {
 158         // nothing cached
 159 }
 160
 161
 162 //
 163 // Writers
 164 //
 165 DiskRep::Writer::Writer(uint32_t attrs)
 166         : mArch(CPU_TYPE_ANY), mAttributes(attrs)
 167 {
 168 }
 169
 170 DiskRep::Writer::~Writer()
 171 { /* virtual */ }
 172
 173 uint32_t DiskRep::Writer::attributes() const
 174 { return mAttributes; }
 175
 176 void DiskRep::Writer::flush()
 177 { /* do nothing */ }
 178
 179
 180 } // end namespace CodeSigning
 181 } // end namespace Security