uniconf/unifilesystemgen.cc

   1 #include "unifilesystemgen.h"
   2 #include "wvfile.h"
   3 #include "wvdiriter.h"
   4 #include "wvfileutils.h"
   5 #include "wvmoniker.h"
   6 #include "wvlinkerhack.h"
   7 #include <sys/types.h>
   8 #include <sys/stat.h>
   9 #include <unistd.h>
  10 #include <fcntl.h>
  11
  12 WV_LINK(UniFileSystemGen);
  13
  14
  15 static IUniConfGen *creator(WvStringParm s, IObject *)
  16 {
  17     return new UniFileSystemGen(s, 0777);
  18 }
  19
  20 WvMoniker<IUniConfGen> UniFileSystemGenMoniker("fs", creator);
  21
  22
  23 UniFileSystemGen::UniFileSystemGen(WvStringParm _dir, mode_t _mode)
  24     : dir(_dir), mode(_mode)
  25 {
  26 }
  27
  28
  29 static bool key_safe(const UniConfKey &key)
  30 {
  31     UniConfKey::Iter i(key);
  32     for (i.rewind(); i.next(); )
  33     {
  34         if (*i == "." || *i == ".." || *i == "")
  35             return false; // unsafe key segments
  36     }
  37
  38     // otherwise a safe filename
  39     return true;
  40 }
  41
  42
  43 WvString UniFileSystemGen::get(const UniConfKey &key)
  44 {
  45     WvString null;
  46
  47     if (!key_safe(key))
  48         return null;
  49
  50     WvString path("%s/%s", dir, key);
  51
  52     // WARNING: this code depends on the ability to open() a directory
  53     // as long as we don't read it, because we want to fstat() it after.
  54     WvFile file(path, O_RDONLY);
  55     if (!file.isok())
  56         return null; // unreadable; pretend it doesn't exist
  57
  58     struct stat st;
  59     if (fstat(file.getrfd(), &st) < 0)
  60         return null; // openable but can't stat?  That's odd.
  61
  62     if (S_ISREG(st.st_mode))
  63     {
  64         WvDynBuf buf;
  65         while (file.isok())
  66             file.read(buf, 4096);
  67         if (file.geterr())
  68             return null;
  69         else
  70             return buf.getstr();
  71     }
  72     else
  73         return ""; // exists, but pretend it's an empty file
  74 }
  75
  76
  77 void UniFileSystemGen::set(const UniConfKey &key, WvStringParm value)
  78 {
  79     if (!key_safe(key))
  80         return;
  81
  82     WvString base("%s/%s", dir, key.removelast(1));
  83     WvString path("%s/%s", dir, key);
  84
  85     mkdirp(base, mode);
  86
  87     if (value.isnull())
  88         rm_rf(path);
  89     else
  90     {
  91         WvFile file(path, O_WRONLY|O_CREAT|O_TRUNC, mode & 0666);
  92         file.write(value);
  93     }
  94 }
  95
  96
  97 void UniFileSystemGen::setv(const UniConfPairList &pairs)
  98 {
  99     setv_naive(pairs);
 100 }
 101
 102
 103 class UniFileSystemGenIter : public UniConfGen::Iter
 104 {
 105 private:
 106     UniFileSystemGen *gen;
 107     WvDirIter i;
 108     UniConfKey rel;
 109
 110 public:
 111     UniFileSystemGenIter(UniFileSystemGen *_gen, WvStringParm path,
 112                          const UniConfKey &_rel)
 113         : gen(_gen), i(path, false), rel(_rel)
 114         { }
 115
 116     ~UniFileSystemGenIter()
 117         { }
 118
 119     void rewind()
 120         { i.rewind(); }
 121
 122     bool next()
 123         { return i.next(); }
 124
 125     UniConfKey key() const
 126         { return i->relname; }
 127
 128     WvString value() const
 129         { return gen->get(WvString("%s/%s", rel, i->relname)); }
 130 };
 131
 132
 133 UniConfGen::Iter *UniFileSystemGen::iterator(const UniConfKey &key)
 134 {
 135     if (!key_safe(key))
 136         return NULL;
 137
 138     return new UniFileSystemGenIter(this, WvString("%s/%s", dir, key), key);
 139 }