sysdeps/posix/fpathconf.c

   1 /* Copyright (C) 1991,1995,1996,1998,2000,2001,2003
   2    Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, write to the Free
  17    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  18    02111-1307 USA.  */
  19
  20 #include <errno.h>
  21 #include <stddef.h>
  22 #include <unistd.h>
  23 #include <limits.h>
  24 #include <sys/stat.h>
  25 #include <sys/statfs.h>
  26 #include <sys/statvfs.h>
  27
  28
  29 /* Get file-specific information about descriptor FD.  */
  30 long int
  31 __fpathconf (fd, name)
  32      int fd;
  33      int name;
  34 {
  35   if (fd < 0)
  36     {
  37       __set_errno (EBADF);
  38       return -1;
  39     }
  40
  41   switch (name)
  42     {
  43     default:
  44       __set_errno (EINVAL);
  45       return -1;
  46
  47     case _PC_LINK_MAX:
  48 #ifdef  LINK_MAX
  49       return LINK_MAX;
  50 #else
  51       return -1;
  52 #endif
  53
  54     case _PC_MAX_CANON:
  55 #ifdef  MAX_CANON
  56       return MAX_CANON;
  57 #else
  58       return -1;
  59 #endif
  60
  61     case _PC_MAX_INPUT:
  62 #ifdef  MAX_INPUT
  63       return MAX_INPUT;
  64 #else
  65       return -1;
  66 #endif
  67
  68     case _PC_NAME_MAX:
  69 #ifdef  NAME_MAX
  70       {
  71         struct statfs buf;
  72         int save_errno = errno;
  73
  74         if (__fstatfs (fd, &buf) < 0)
  75           {
  76             if (errno == ENOSYS)
  77               {
  78                 __set_errno (save_errno);
  79                 return NAME_MAX;
  80               }
  81             else if (errno == ENODEV)
  82               __set_errno (EINVAL);
  83
  84             return -1;
  85           }
  86         else
  87           {
  88 #ifdef _STATFS_F_NAMELEN
  89             return buf.f_namelen;
  90 #else
  91 # ifdef _STATFS_F_NAME_MAX
  92             return buf.f_name_max;
  93 # else
  94             return NAME_MAX;
  95 # endif
  96 #endif
  97           }
  98       }
  99 #else
 100       return -1;
 101 #endif
 102
 103     case _PC_PATH_MAX:
 104 #ifdef  PATH_MAX
 105       return PATH_MAX;
 106 #else
 107       return -1;
 108 #endif
 109
 110     case _PC_PIPE_BUF:
 111 #ifdef  PIPE_BUF
 112       return PIPE_BUF;
 113 #else
 114       return -1;
 115 #endif
 116
 117     case _PC_CHOWN_RESTRICTED:
 118 #ifdef  _POSIX_CHOWN_RESTRICTED
 119       return _POSIX_CHOWN_RESTRICTED;
 120 #else
 121       return -1;
 122 #endif
 123
 124     case _PC_NO_TRUNC:
 125 #ifdef  _POSIX_NO_TRUNC
 126       return _POSIX_NO_TRUNC;
 127 #else
 128       return -1;
 129 #endif
 130
 131     case _PC_VDISABLE:
 132 #ifdef  _POSIX_VDISABLE
 133       return _POSIX_VDISABLE;
 134 #else
 135       return -1;
 136 #endif
 137
 138     case _PC_SYNC_IO:
 139 #ifdef  _POSIX_SYNC_IO
 140       return _POSIX_SYNC_IO;
 141 #else
 142       return -1;
 143 #endif
 144
 145     case _PC_ASYNC_IO:
 146 #ifdef  _POSIX_ASYNC_IO
 147       {
 148         /* AIO is only allowed on regular files and block devices.  */
 149         struct stat64 st;
 150
 151         if (__fxstat64 (_STAT_VER, fd, &st) < 0
 152             || (! S_ISREG (st.st_mode) && ! S_ISBLK (st.st_mode)))
 153           return -1;
 154         else
 155           return 1;
 156       }
 157 #else
 158       return -1;
 159 #endif
 160
 161     case _PC_PRIO_IO:
 162 #ifdef  _POSIX_PRIO_IO
 163       return _POSIX_PRIO_IO;
 164 #else
 165       return -1;
 166 #endif
 167
 168     case _PC_SOCK_MAXBUF:
 169 #ifdef  SOCK_MAXBUF
 170       return SOCK_MAXBUF;
 171 #else
 172       return -1;
 173 #endif
 174
 175     case _PC_FILESIZEBITS:
 176 #ifdef FILESIZEBITS
 177       return FILESIZEBITS;
 178 #else
 179       /* We let platforms with larger file sizes overwrite this value.  */
 180       return 32;
 181 #endif
 182
 183     case _PC_REC_INCR_XFER_SIZE:
 184       /* XXX It is not entirely clear what the limit is supposed to do.
 185          What is incremented?  */
 186       return -1;
 187
 188     case _PC_REC_MAX_XFER_SIZE:
 189       /* XXX It is not entirely clear what the limit is supposed to do.
 190          In general there is no top limit of the number of bytes which
 191          case be transported at once.  */
 192       return -1;
 193
 194     case _PC_REC_MIN_XFER_SIZE:
 195       {
 196         /* XXX It is not entirely clear what the limit is supposed to do.
 197            I assume this is the block size of the filesystem.  */
 198         struct statvfs64 sv;
 199
 200         if (__fstatvfs64 (fd, &sv) < 0)
 201           return -1;
 202         return sv.f_bsize;
 203       }
 204
 205     case _PC_REC_XFER_ALIGN:
 206       {
 207         /* XXX It is not entirely clear what the limit is supposed to do.
 208            I assume that the number should reflect the minimal block
 209            alignment.  */
 210         struct statvfs64 sv;
 211
 212         if (__fstatvfs64 (fd, &sv) < 0)
 213           return -1;
 214         return sv.f_frsize;
 215       }
 216
 217     case _PC_ALLOC_SIZE_MIN:
 218       {
 219         /* XXX It is not entirely clear what the limit is supposed to do.
 220            I assume that the number should reflect the minimal block
 221            alignment.  */
 222         struct statvfs64 sv;
 223
 224         if (__fstatvfs64 (fd, &sv) < 0)
 225           return -1;
 226         return sv.f_frsize;
 227       }
 228
 229     case _PC_SYMLINK_MAX:
 230       /* In general there are no limits.  If a system has one it should
 231          overwrite this case.  */
 232       return -1;
 233
 234     case _PC_2_SYMLINKS:
 235       /* Unix systems generally have symlinks.  */
 236       return 1;
 237     }
 238 }
 239
 240 #undef __fpathconf
 241 weak_alias (__fpathconf, fpathconf)