rom/dos/open.c

   1 /*
   2     Copyright © 1995-2011, The AROS Development Team. All rights reserved.
   3     $Id$
   4
   5     Desc: Open a file with the specified mode.
   6     Lang: english
   7 */
   8
   9 #include <aros/debug.h>
  10 #include <exec/memory.h>
  11 #include <exec/lists.h>
  12 #include <proto/exec.h>
  13 #include <utility/tagitem.h>
  14 #include <dos/dosextens.h>
  15 #include <dos/filesystem.h>
  16 #include <dos/stdio.h>
  17 #include <proto/dos.h>
  18 #include <proto/utility.h>
  19
  20 #include "dos_intern.h"
  21
  22 static LONG InternalOpen(CONST_STRPTR name, LONG accessMode,
  23     struct FileHandle *handle, LONG soft_nesting, struct DosLibrary *DOSBase);
  24
  25 #define MAX_SOFT_LINK_NESTING 16 /* Maximum level of soft links nesting */
  26
  27 /*****************************************************************************
  28
  29     NAME */
  30 #include <proto/dos.h>
  31
  32         AROS_LH2(BPTR, Open,
  33
  34 /*  SYNOPSIS */
  35         AROS_LHA(CONST_STRPTR, name,       D1),
  36         AROS_LHA(LONG,         accessMode, D2),
  37
  38 /*  LOCATION */
  39         struct DosLibrary *, DOSBase, 5, Dos)
  40
  41 /*  FUNCTION
  42         Opens a file for read and/or write depending on the accessmode given.
  43
  44     INPUTS
  45         name       - NUL terminated name of the file.
  46         accessMode - One of MODE_OLDFILE   - open existing file
  47                             MODE_NEWFILE   - delete old, create new file
  48                                              exclusive lock
  49                             MODE_READWRITE - open new one if it doesn't exist
  50
  51     RESULT
  52         Handle to the file or 0 if the file couldn't be opened.
  53         IoErr() gives additional information in that case.
  54
  55     NOTES
  56
  57     EXAMPLE
  58
  59     BUGS
  60
  61     SEE ALSO
  62
  63     INTERNALS
  64
  65 *****************************************************************************/
  66 {
  67     AROS_LIBFUNC_INIT
  68
  69     struct FileHandle *ret;
  70     LONG error;
  71
  72     /* Sanity check */
  73     if (name == NULL) return BNULL;
  74
  75     /* Create filehandle */
  76     ret = (struct FileHandle *)AllocDosObject(DOS_FILEHANDLE,NULL);
  77
  78     if(ret != NULL)
  79     {
  80         LONG ok = InternalOpen(name, accessMode, ret, MAX_SOFT_LINK_NESTING, DOSBase);
  81         D(bug("[Open] = %d Error = %d\n", ok, IoErr()));
  82         if (ok)
  83         {
  84             return MKBADDR(ret);
  85         }
  86         else
  87         {
  88             error = IoErr();
  89             FreeDosObject(DOS_FILEHANDLE,ret);
  90         }
  91     }
  92     else
  93         error = ERROR_NO_FREE_STORE;
  94
  95     SetIoErr(error);
  96     return BNULL;
  97
  98     AROS_LIBFUNC_EXIT
  99 } /* Open */
 100
 101 /* Try to open name recursively calling itself in case it's a soft link.
 102    Store result in handle. Return boolean value indicating result. */
 103 static LONG InternalOpen(CONST_STRPTR name, LONG accessMode,
 104     struct FileHandle *handle, LONG soft_nesting, struct DosLibrary *DOSBase)
 105 {
 106     /* Get pointer to process structure */
 107     struct Process *me = (struct Process *)FindTask(NULL);
 108     LONG ret = DOSFALSE;
 109     LONG error = 0;
 110     BPTR con, ast;
 111
 112     D(bug("[Open] Process: 0x%p \"%s\", Window: 0x%p, Name: \"%s\" FH: 0x%p\n", me, me->pr_Task.tc_Node.ln_Name, me->pr_WindowPtr, name, handle));
 113
 114     if(soft_nesting == 0)
 115     {
 116         SetIoErr(ERROR_TOO_MANY_LEVELS);
 117         return DOSFALSE;
 118     }
 119
 120     switch(accessMode)
 121     {
 122         case MODE_NEWFILE:
 123         case MODE_READWRITE:
 124             con = me->pr_COS;
 125             ast = me->pr_CES ? me->pr_CES : me->pr_COS;
 126             break;
 127
 128         case MODE_OLDFILE:
 129             ast = con = me->pr_CIS;
 130             break;
 131
 132         default:
 133             if (accessMode & (FMF_CREATE|FMF_CLEAR))
 134             {
 135                 con = me->pr_COS;
 136                 ast = me->pr_CES ? me->pr_CES : me->pr_COS;
 137             }
 138             else
 139                 ast = con = me->pr_CIS;
 140             break;
 141     }
 142
 143     if (!Stricmp(name, "CONSOLE:"))
 144         error = fs_Open(handle, REF_CONSOLE, con, accessMode, name, DOSBase);
 145     else if (!Stricmp(name, "*"))
 146         error = fs_Open(handle, REF_CONSOLE, ast, accessMode, name, DOSBase);
 147 #ifdef AROS_DOS_PACKETS
 148     /* Special case for NIL:, unsupported by IOFS */
 149     else if (!Stricmp(name, "NIL:"))
 150     {
 151         SetIoErr(0);
 152
 153         handle->fh_Type = BNULL;
 154         /* NIL: is considered interactive */
 155         handle->fh_Port = (struct MsgPort*)DOSTRUE;
 156         return DOSTRUE;
 157     }
 158 #endif
 159     else
 160     {
 161         BPTR cur = BNULL;
 162         struct DevProc *dvp = NULL;
 163         STRPTR filename = strchr(name, ':');
 164
 165         if (!filename)
 166         {
 167             /* No ':', pathname relative to current dir */
 168             cur = me->pr_CurrentDir;
 169
 170             if (!cur)
 171                 cur = DOSBase->dl_SYSLock;
 172
 173             if (cur)
 174                 error = fs_Open(handle, REF_LOCK, cur, accessMode, name, DOSBase);
 175             else
 176                 /*
 177                  * This can be reached if we attempt to load disk-based library or
 178                  * device before dl_SYSLock is assigned. This can happen, for example,
 179                  * when attempting to mount a handler at boottime which is missing
 180                  * from the kickstart.
 181                  */
 182                 error = ERROR_OBJECT_NOT_FOUND;
 183         }
 184         else
 185         {
 186             filename++;
 187             do
 188             {
 189                 if ((dvp = GetDeviceProc(name, dvp)) == NULL)
 190                 {
 191                     error = IoErr();
 192                     break;
 193                 }
 194
 195                 error = fs_Open(handle, REF_DEVICE, MKBADDR(dvp), accessMode, filename, DOSBase);
 196             } while(error == ERROR_OBJECT_NOT_FOUND && accessMode != MODE_NEWFILE);
 197
 198             if (error == ERROR_NO_MORE_ENTRIES)
 199                 error = ERROR_OBJECT_NOT_FOUND;
 200         }
 201
 202         if (error == ERROR_IS_SOFT_LINK)
 203         {
 204             STRPTR softname = ResolveSoftlink(cur, dvp, name, DOSBase);
 205
 206             if (softname)
 207             {
 208                 /* All OK */
 209                 BPTR olddir = BNULL;
 210
 211                 if (dvp)
 212                 {
 213                     olddir = me->pr_CurrentDir;
 214                     error = RootDir(dvp, DOSBase);
 215                 }
 216                 else
 217                     error = 0;
 218
 219                 if (!error)
 220                 {
 221                     ret = InternalOpen(softname, accessMode, handle, soft_nesting - 1, DOSBase);
 222                     error = ret ? 0 : IoErr();
 223
 224                     if (olddir)
 225                         UnLock(CurrentDir(olddir));
 226                 }
 227
 228                 FreeVec(softname);
 229             }
 230             else
 231                 error = IoErr();
 232         }
 233
 234         FreeDeviceProc(dvp);
 235     }
 236
 237     if (!error)
 238     {
 239         if (IsInteractive(MKBADDR(handle)))
 240             SetVBuf(MKBADDR(handle), NULL, BUF_LINE, -1);
 241
 242         return DOSTRUE;
 243     }
 244     else
 245     {
 246         SetIoErr(error);
 247         return DOSFALSE;
 248     }
 249 }