improve truename compatibility for character devices, additional debug prints, rename cds netflags to better match purpose and note unused.

Author: PerditionC

hdr/cds.h

@@ -44,7 +44,7 @@ struct cds {
     } _cdsRedir;
   } _cdsUnion;
 
-  UWORD cdsStoreUData;
+  UWORD cdsUserData;         /* initialized to 0xFFFF, otherwise unused by kernel */
 
 #define cdsJoinOffset cdsBackslashOffset
   WORD cdsBackslashOffset; /* Position of "root directory" backslash for
@@ -55,9 +55,9 @@ struct cds {
                                      if local path: ofs > colon
                            */
 
-  BYTE cdsNetFlag1;        /* According to PCDOS 7 Tech Ref: IFS drive, 2=IFS, 4=NetUse */
+  BYTE cdsIfsType;         /* According to PCDOS 7 Tech Ref: IFS drive, 2=IFS, 4=NetUse, unused by kernel */
   BYTE FAR *cdsIfs;        /* Pointer to Installable File System Header */
-  UWORD cdsNetFlags2;      /* File System specific data */
+  UWORD cdsFileSysData;    /* File System specific data, unused by kernel */
 
 };
 

kernel/dosfns.c

@@ -116,10 +116,13 @@ struct cds FAR *get_cds(unsigned drive)
   struct cds FAR *cdsp;
   unsigned flags;
 
-  if (drive >= lastdrive)
+  if (drive >= lastdrive) {
+    DebugPrintf(("%u >= %u\n", drive, lastdrive));
     return NULL;
+  }
   cdsp = &CDSp[drive];
   flags = cdsp->cdsFlags;
+  DebugPrintf(("flags=%0x valid=%04x, join=%04x, net=%04x, DPB is NULL?%d\n", flags, flags & CDSVALID, flags & CDSJOINED, flags & CDSNETWDRV, (cdsp->cdsDpb == NULL)?0:1));
   /* Entry is disabled or JOINed drives are accessable by the path only */
   if (!(flags & CDSVALID) || (flags & CDSJOINED) != 0)
     return NULL;
@@ -541,6 +544,7 @@ long DosOpenSft(char FAR * fname, unsigned flags, unsigned attrib)
   sftp->sft_attrib = attrib = attrib | D_ARCHIVE;
 
   /* check for a (local) device */
+  DebugPrintf(("result for %Fs is %s%s%s%s",fname,(result & IS_DEVICE)?"device ":"X",(result & IS_NETWORK)?"network ":"N",(dhp = IsDevice(fname)) != NULL?"IsDevice!=NULL ":"="));
   if ((result & IS_DEVICE) && !(result & IS_NETWORK) && (dhp = IsDevice(fname)) != NULL)
   {
     int rc = DeviceOpenSft(dhp, sftp);
@@ -1392,6 +1396,7 @@ struct dhdr FAR *IsDevice(const char FAR * fname)
        ((*froot=='.') && ((*(froot+1)=='\0') || (*(froot+2)=='\0' && *(froot+1)=='.')))
      )
   {
+      DebugPrintf(("root is blank\n"));
     return NULL;
   }
 
@@ -1402,9 +1407,11 @@ struct dhdr FAR *IsDevice(const char FAR * fname)
     if (!(dhp->dh_attr & ATTR_CHAR))  /* if this is block device, skip */
       continue;
 
+    DebugPrintf(("checking filename\n"));
     for (i = 0; i < FNAME_SIZE; i++)
     {
       unsigned char c1 = (unsigned char)froot[i];
+      DebugPrintf(("%c",c1));
       /* ignore extensions and handle filenames shorter than FNAME_SIZE */
       if (c1 == '.' || c1 == '\0')
       {
@@ -1421,11 +1428,13 @@ struct dhdr FAR *IsDevice(const char FAR * fname)
         break;
     }
 
+    DebugPrintf(("\ni=%d\n", i));
     /* if found a match then return device header */
     if (i == FNAME_SIZE)
       return dhp;
   }
 
+  DebugPrintf(("Not device\n"));
   return NULL;
 }
 
@@ -1453,7 +1462,7 @@ COUNT DosTruename(const char FAR *src, char FAR *dest)
      Therefore, the name is created in an internal buffer
      and copied into the user buffer only on success.
   */  
-  COUNT rc = truename(src, PriPathName, CDS_MODE_ALLOW_WILDCARDS);
+  COUNT rc = truename(src, PriPathName, CDS_MODE_ALLOW_WILDCARDS|CDS_MODE_CHECK_DEV_PATH);
   if (rc >= SUCCESS)
   {
     fstrcpy(dest, PriPathName);

kernel/inthndlr.c

@@ -2991,7 +2991,7 @@ VOID ASMCFUNC int2F_12_handler(struct int2f12regs FAR *pr)
         }
         TempCDS.cdsStrtClst = 0xffff;
         TempCDS.cdsParam = 0xffff;
-        TempCDS.cdsStoreUData = 0xffff;
+        TempCDS.cdsUserData = 0xffff;
         r.CX = sizeof(TempCDS);
         r.ES = FP_SEG(&TempCDS);
         r.DI = FP_OFF(&TempCDS);

kernel/kernel.asm

@@ -873,7 +873,7 @@ current_device  times 2 dw 0       ;27A - point to device header if filename is
                 global  _lpCurSft
 _lpCurSft       times 2 dw 0       ;27e - Current SFT
                 global  _current_ldt
-_current_ldt     times 2 dw 0       ;282 - Current CDS
+_current_ldt     times 2 dw 0       ;282 - Current CDS (ThisCDS in published MSDOS sources)
                 global  _sda_lpFcb
 _sda_lpFcb      times 2 dw 0       ;286 - pointer to callers FCB
                 global  _current_sft_idx

kernel/main.c

@@ -401,7 +401,7 @@ STATIC VOID FsConfig(VOID)
     }
     pcds_table->cdsStrtClst = 0xffff;
     pcds_table->cdsParam = 0xffff;
-    pcds_table->cdsStoreUData = 0xffff;
+    pcds_table->cdsUserData = 0xffff;
     pcds_table->cdsJoinOffset = 2;
   }
 

kernel/newstuff.c

@@ -282,93 +282,11 @@ COUNT truename(const char FAR * src, char * dest, COUNT mode)
     /* referenced for network with empty current_ldt.           */
     return IS_NETWORK;
   }
-  
-  /* Do we have a drive?                                          */
-  if (src[1] == ':')
-    result = drLetterToNr(DosUpFChar(src0));
-  else
-    result = default_drive;
-
-  dhp = IsDevice(src);
-
-  cdsEntry = get_cds(result);
-  if (cdsEntry == NULL)
-  {
-    /* If opening a character device, DOS allows device name
-       to be prefixed by [invalid] drive letter and/or optionally
-       \DEV\ directory prefix, however, any other directory
-       including root (\) is an invalid path if drive is not
-       valid and returns such.
-       Whereas truename always fails for invalid drive.
-    */
-    if (dhp && (mode & CDS_MODE_CHECK_DEV_PATH) && (result >= lastdrive))
-    {
-      /* Note: check for (result >= lastdrive) means invalid drive
-         was provided as otherwise we would have used default_drive
-         so we know src in the form of X:?
-         fail if anything other than no path or path is \DEV\
-      */
-      const char FAR *s = src+2;
-      char c = *s;
-
-      if( c != '\\' && c != '/' ) c = '\0';
-      /* could be 1 letter devicename, don't go scanning random memory */
-      if (*(src+3) != '\0') 
-      {
-        s = fstrchr(src+3, '\\'); /* ?is there \ or / other than immediately after drive: */
-        if (s == NULL) s = fstrchr(src+3, '/');
-      }
-      else
-      {
-        s = NULL;
-      }
-
-      if (c == '\0')
-      {
-        /* either X:devicename or X:path\devicename */
-        if (s != NULL) goto invalid_path;
-      }
-      else
-      {
-        /* either X:\devicename or X:\path\devicename 
-           only X:\DEV\devicename is valid path
-        */
-        if (s == NULL) goto invalid_path;
-        if (s != src+6) goto invalid_path;
-        if (fmemcmp(src+3, "DEV", 3) != 0) goto invalid_path;
-        s = fstrchr(src+7, '\\');
-        if (s == NULL) s = fstrchr(src+7, '/');
-        if (s != NULL) goto invalid_path;
-      }
-  
-      /* use CDS of current drive (MS-DOS may return drive P: for invalid drive.) */
-      result = default_drive;
-      cdsEntry = get_cds(result);
-      if (cdsEntry == NULL) goto invalid_path;
-    }
-    else
-    {
-invalid_path:
-        return DE_PATHNOTFND;
-    }
-  }
-
-  fmemcpy(&TempCDS, cdsEntry, sizeof(TempCDS));
-  tn_printf(("CDS entry: #%u @%p (%u) '%s'\n", result, cdsEntry,
-            TempCDS.cdsBackslashOffset, TempCDS.cdsCurrentPath));
-  /* is the current_ldt thing necessary for compatibly??
-     -- 2001/09/03 ska*/
-  current_ldt = cdsEntry;
-  if (TempCDS.cdsFlags & CDSNETWDRV)
-    result |= IS_NETWORK;
-  
-  if (dhp)
-    result |= IS_DEVICE;
 
   /* Try if the Network redirector wants to do it */
   /* via Qualify Remote Filename call & validate results */
-  assert(sizeof(PriPathName)>=12); /* dest is always pointer to PriPathName */
-  memset(dest, 0, 12);  /* enable can verify redirector set result value */
+  assert(sizeof(PriPathName)>=12); /* dest is always pointer to PriPathName or SecPathName */
+  memset(dest, 0, 12);  /* so we can verify redirector set result value */
   /* MUX succeeded and really something */
   if (!(mode & CDS_MODE_SKIP_PHYSICAL) &&
       QRemote_Fn(dest, src) == SUCCESS && dest[0] != '\0')
@@ -392,22 +310,114 @@ COUNT truename(const char FAR * src, char * dest, COUNT mode)
     return result;
   }
 
+  /* Redirector interface failed (or skipped) --> proceed with local mapper */
+  
+  /* Was a drive letter provided?  If not then use current drive */
+  if (src[1] == ':')
+    result = drLetterToNr(DosUpFChar(src0));
+  else
+    result = default_drive;
+
+  dhp = IsDevice(src);
+
+  /* Note: [older] redirectors may not provide Int 2Fh API and instead simply wrap Int 21h calls
+     so above callout to redirector may fail but still be a redirected (mapped) drive that is invalid to us.
+
+     When given a character device, Truename or Open allows device name to be prefixed by invalid
+     drive letter and\or optional \DEV\ directory prefix, however any other directory including
+     root path (\) will always return error. However, if drive is valid, then for character 
+     devices any path may be provided.
+     For example:
+       CON will use default drive and assuming default is X: then same as X:CON
+       X:CON and X:\DEV\CON will succeed regardless if X: is valid or not
+
+       If X: is a valid drive then returns proper path for drive (X:/CON or \\remote\path\CON respectively)
+       If X: is not a valid drive then if no path (not even root \ path) or path exactly \DEV\ will
+       succeed and use dummy path of P:/CON  (always P: apparently for dummy CDS), or if any path than \DEV\
+       will fail.
+
+       X:\CON and X:\path\CON will always succeed if X: is a valid drive even if path does not exists
+       If X: is a valid drive then returns provided path for drive (X:/CON or \\remote\path\CON respectively).
+  */
+  
+  /* determine if valid drive */
+  cdsEntry = get_cds(result);
+
+  /* is this a character device (dhp != NULL)? if so check special cases 
+     if cdsEntry is not NULL then valid drive, so any path acceptable for character device
+  */
+  if (dhp && (mode & CDS_MODE_CHECK_DEV_PATH) && (cdsEntry == NULL))
+  {
+    /* determine if drive letter provided (we know at least 1 character long) */
+    const char FAR *s = src+1;
+    const char FAR *hasSlash;
+    if (*s == ':') s++; else s--; /* skip drive (X:) if provided */    
+    /* s points to start of device name or path, just past optional drive letter */
+    
+    /* determine if path provided, any \ or / characters indicate path including root */
+    hasSlash = fstrchr(s, '\\');
+    if (hasSlash == NULL) hasSlash = fstrchr(s, '/');
+    
+    if (hasSlash != NULL) {
+      /* only \DEV\ (with leading \) or /DEV/ for path portion allowed since drive is invalid */
+      tn_printf(("-->%Fs<--\n", s));
+      if ((*s == '\\') || (*s == '/')) {
+          unsigned char c[6];
+          unsigned x;
+          c[0]= *(++s) & 0xDF;  /* get uppercase next character */
+          c[1]= *(++s) & 0xDF;
+          c[2]= *(++s) & 0xDF;
+          c[3]= *(++s);
+          if (c[3]=='\\') c[3]='/';
+          s++; /* s now points to start of device name */
+          c[4]= '\0';
+          x = fstrcmp((char *)c, "DEV/");
+          tn_printf(("comparing %s to %s == %d\n", c, "DEV/", x)); 
+          if (x != 0) goto invalid_path;
+          tn_printf(("ok\n"));
+      } else {
+          /* there is a / or \ but not at beginning so must be a path, which is invalid for device */
+          goto invalid_path;
+      }
+    } /* else { just devicename or X:devicename, drive even default need not be valid to us (mapped drive with invalid CDS) } */
+
+    /* we have a character device with invalid drive
+       instead of using CDS of current drive follow MS-DOS convention of returning drive P: for invalid drive.
+     */
+    result = 'P' - 'A';  /* return drive P: */
+    /* cdsEntry = get_cds_unvalidated(result);  * WARNING: may point past valid memory! if result >= lastdrive */
+    cdsEntry = (struct cds FAR *)MK_FP(-1,-1);
+    tn_printf(("No CDS using entry P: #%u\n", result));
+    fmemset(&TempCDS, 0, sizeof(TempCDS));
+    fstrcpy(TempCDS.cdsCurrentPath, s);  /* just device name no path or drive letter */
+    tn_printf(("cds=%s\n", TempCDS.cdsCurrentPath));
+  }
+
+  
+  /* Note: on redirected drives cdsEntry may not be NULL but with dhp==NULL, so must check network redir prior to here */
+  if (cdsEntry == NULL)
+  {
+invalid_path:
+    return DE_PATHNOTFND;
+  } else {
+    if (cdsEntry != (struct cds FAR *)MK_FP(-1,-1))
+    fmemcpy(&TempCDS, cdsEntry, sizeof(TempCDS));
+  }
+  current_ldt = cdsEntry; /* update current_ldt for compatibility, stored in LOL */
+  tn_printf(("CDS entry: #%u @%p (%u) '%s'\n", result, cdsEntry,
+            TempCDS.cdsBackslashOffset, TempCDS.cdsCurrentPath));
+  if (TempCDS.cdsFlags & CDSNETWDRV)
+    result |= IS_NETWORK;
+  
+  if (dhp)
+    result |= IS_DEVICE;
+
   /* Redirector interface failed --> proceed with local mapper */
   dest[0] = drNrToLetter(result & 0x1f);
   dest[1] = ':';
 
-  /* Do we have a drive? */
-  if (src[1] == ':') {
-    src += 2;
-    if (result & IS_DEVICE)
-    {
-      /* stripped optional X: from source, and verified not \path\devicename
-         so treat \devicename as devicename same (and \dev\devicename as dev\devicename)
-       */
-      if (src[0] == '\\' || src[0] == '/')
-        src++;
-    }
-  }
+  /* Do we have a drive? if so skip over it */
+  if (src[1] == ':') src += 2;
 
 /*
     Code repoff from dosfns.c
@@ -444,6 +454,7 @@ COUNT truename(const char FAR * src, char * dest, COUNT mode)
         src = froot;
       }
     }
+    tn_printf(("DEVICE: dest=%s, src=%Fs\n", dest, (char far *)src));
   }
 
   /* Make fully-qualified logical path */
@@ -458,7 +469,7 @@ COUNT truename(const char FAR * src, char * dest, COUNT mode)
     cp = TempCDS.cdsCurrentPath;
     /* ensure termination of strcpy */
     cp[MAX_CDSPATH - 1] = '\0';
-    if ((TempCDS.cdsFlags & CDSNETWDRV) == 0)
+    if ((cdsEntry != (struct cds FAR *)MK_FP(-1,-1)) && ((TempCDS.cdsFlags & CDSNETWDRV) == 0))
     {
       if (media_check(TempCDS.cdsDpb) < 0)
         return DE_PATHNOTFND;
@@ -668,10 +679,6 @@ COUNT truename(const char FAR * src, char * dest, COUNT mode)
     }
     /* nothing found => continue normally */
   }
-  if ((mode & CDS_MODE_CHECK_DEV_PATH) &&
-      ((result & (IS_DEVICE|IS_NETWORK)) == IS_DEVICE) &&
-      dest[2] != '/' && !dir_exists(dest))
-    return DE_PATHNOTFND;
 
   /* Note: Not reached on error or if JOIN or QRemote_Fn (2f.1123) matched */
   if (mode==CDS_MODE_ALLOW_WILDCARDS) /* DosTruename mode */

kernel/proto.h

@@ -381,6 +381,7 @@ long ASMPASCAL network_redirector_mx(unsigned cmd, void far *s, void *arg);
 #define remote_lseek(s,new_pos) network_redirector_mx(REM_LSEEK, s, &new_pos)
 #define remote_setfattr(attr) (int)network_redirector_mx(REM_SETATTR, NULL, (void *)attr)
 #define remote_printredir(dx,ax) (int)network_redirector_mx(REM_PRINTREDIR, MK_FP(0,dx),(void *)ax)
+/* local (near) address of s pushed on stack, where s is far (segment:offset) of argument */
 #define QRemote_Fn(d,s) (int)network_redirector_mx(REM_FILENAME, d, (void *)&s)
 
 UWORD get_machine_name(BYTE FAR * netname);

tests/int2f-12/t121f.c

@@ -25,7 +25,7 @@
  *       cdsFlags = 0
  *     cdsStrtClst    = 0xFFFF
  *     cdsParam       = 0xFFFF
- *     cdsStoreUData  = 0xFFFF
+ *     cdsUserData  = 0xFFFF
  *
  * Care masks:
  *   Success path: CARE_FLAGS | CARE_BUF