lib/libc/gen/getvfsent.c

   1 /*
   2  * getvfsent.c - get a listing of installed filesystems
   3  * Written September 1994 by Garrett A. Wollman
   4  * This file is in the public domain.
   5  *
   6  * $FreeBSD: src/lib/libc/gen/getvfsent.c,v 1.14.2.1 2001/03/05 09:19:38 obrien Exp $
   7  */
   8
   9 #include <sys/param.h>
  10 #include <sys/linker.h>
  11 #include <sys/mount.h>
  12 #include <sys/sysctl.h>
  13 #include <stdlib.h>
  14 #include <string.h>
  15 #include <unistd.h>
  16
  17 /* XXX hide some compatibility problems. */
  18 #undef getvfsbyname
  19
  20 static struct ovfsconf *_vfslist = NULL;
  21 static struct ovfsconf _vfsconf;
  22 static size_t _vfslistlen = 0;
  23 static int _vfs_keeplist = 0;
  24 static size_t _vfs_index = 0;
  25
  26 static int
  27 initvfs(void)
  28 {
  29         int mib[2] = { CTL_VFS, VFS_VFSCONF };
  30         size_t size = 0;
  31         int rv;
  32
  33         rv = sysctl(mib, 2, NULL, &size, NULL, (size_t)0);
  34         if(rv < 0)
  35                 return 0;
  36
  37         if(_vfslist)
  38                 free(_vfslist);
  39         _vfslist = malloc(size);
  40         if(!_vfslist)
  41                 return 0;
  42
  43         rv = sysctl(mib, 2, _vfslist, &size, NULL, (size_t)0);
  44         if(rv < 0) {
  45                 free(_vfslist);
  46                 _vfslist = NULL;
  47                 return 0;
  48         }
  49
  50         _vfslistlen = size / sizeof(_vfslist[0]);
  51         return 1;
  52 }
  53
  54 struct ovfsconf *
  55 getvfsent(void)
  56 {
  57         if(!_vfslist && !initvfs())
  58                 return 0;
  59
  60         do {
  61                 if(_vfs_index >= _vfslistlen)
  62                         return 0;
  63
  64                 _vfsconf = _vfslist[_vfs_index++];
  65         } while(!_vfsconf.vfc_vfsops);
  66
  67         if(!_vfs_keeplist) {
  68                 free(_vfslist);
  69                 _vfslist = NULL;
  70         }
  71         return &_vfsconf;
  72 }
  73
  74 struct ovfsconf *
  75 getvfsbyname(const char *name)
  76 {
  77         size_t i;
  78
  79         if(!_vfslist && !initvfs())
  80                 return 0;
  81
  82         for(i = 0; i < _vfslistlen; i++) {
  83                 if( ! strcmp(_vfslist[i].vfc_name, name) )
  84                         break;
  85         }
  86
  87         if(i < _vfslistlen)
  88                 _vfsconf = _vfslist[i];
  89
  90         if(!_vfs_keeplist) {
  91                 free(_vfslist);
  92                 _vfslist = NULL;
  93         }
  94
  95         if(i < _vfslistlen)
  96                 return &_vfsconf;
  97         else
  98                 return 0;
  99 }
 100
 101 struct ovfsconf *
 102 getvfsbytype(int type)
 103 {
 104         size_t i;
 105
 106         if(!_vfslist && !initvfs())
 107                 return 0;
 108
 109         for(i = 0; i < _vfslistlen; i++) {
 110                 if(_vfslist[i].vfc_index == type)
 111                         break;
 112         }
 113
 114         if(i < _vfslistlen)
 115                 _vfsconf = _vfslist[i];
 116
 117         if(!_vfs_keeplist) {
 118                 free(_vfslist);
 119                 _vfslist = NULL;
 120         }
 121
 122         if(i < _vfslistlen)
 123                 return &_vfsconf;
 124         else
 125                 return 0;
 126 }
 127
 128 void
 129 setvfsent(int keep)
 130 {
 131         if(_vfslist && !keep) {
 132                 free(_vfslist);
 133                 _vfslist = NULL;
 134         }
 135
 136         _vfs_keeplist = keep;
 137         _vfs_index = 0;
 138 }
 139
 140 void
 141 endvfsent(void)
 142 {
 143         if(_vfslist) {
 144                 free(_vfslist);
 145                 _vfslist = NULL;
 146         }
 147
 148         _vfs_index = 0;
 149 }
 150
 151 int
 152 vfsisloadable(const char *name __unused)
 153 {
 154         return 1;
 155 }
 156
 157 int
 158 vfsload(const char *name)
 159 {
 160         int status;
 161
 162         status = kldload(name);
 163         return status == -1 ? status : 0;
 164 }