Initial import of the CDE 2.1.30 sources from the Open Group.

cde/programs/dtmail/libDtMail/Common/DetermineFileLocality.C

@@ -0,0 +1,170 @@
+/*
+ *+SNOTICE
+ *
+ *      $TOG: DetermineFileLocality.C /main/9 1997/12/22 16:30:59 bill $
+ *
+ *      RESTRICTED CONFIDENTIAL INFORMATION:
+ *       
+ *      The information in this document is subject to special
+ *      restrictions in a confidential disclosure agreement between
+ *      HP, IBM, Sun, USL, SCO and Univel.  Do not distribute this
+ *      document outside HP, IBM, Sun, USL, SCO, or Univel without
+ *      Sun's specific written approval.  This document and all copies
+ *      and derivative works thereof must be returned or destroyed at
+ *      Sun's request.
+ *
+ *      Copyright 1993 Sun Microsystems, Inc.  All rights reserved.
+ *
+ *+ENOTICE
+ */
+
+#include <sys/types.h>
+#include <unistd.h>
+#include <string.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <assert.h>
+
+#if defined(SVR4)
+#include <sys/stat.h>
+#include <sys/statvfs.h>
+#include <sys/mnttab.h>
+#include <sys/mntent.h>
+#include <sys/param.h>
+#endif
+
+#include <DtMail/DtMail.hh>
+
+/*
+ * Returns: length of second argument if it is a prefix of the
+ * first argument, otherwise zero.
+ */
+static int
+preflen(char * str, char * pref)
+{
+  int len;
+
+  assert(str != NULL);
+  assert(pref != NULL);
+
+  len = strlen(pref);
+  if (strncmp(str, pref, len) == 0)
+    return (len);
+  return (0);
+}
+
+// DetermineFileLocality -- determine if specified path object is local
+//		or remote to the current system
+// Arguments:
+//  const char * path	-- -> path to object whose locality is to be determined
+// Outputs:
+//  None.
+// Returns:
+//  (DtmFileLocality) -- determined locality of the specified path object:
+//	FL_UNKNOWN	-- locality of object cannot be determined
+//	FL_LOCAL	-- the path object is local to this system
+//	FL_REMOTE	-- the path object is remote to this system
+//			-- (such as an NFS mounted file system object)
+//	FL_LOCAL_AND_REMOTE -- the path object is locally available, yet
+//			-- it resides remotely (such as a CACHEFS object)
+//
+
+enum DtmFileLocality
+DtMail::DetermineFileLocality(const char * path)
+{
+#if defined(SVR4)
+  FILE *mfp;
+  struct mnttab *mnt;
+  struct mnttab sysvmnt;
+  int fsTypeLen = 0;
+  int len;
+  char realPath[MAXPATHLEN];		// resolved symbolic link
+  char linkname[MAXPATHLEN];		// for symbolic link chasing
+  char fsType[MAXPATHLEN];		// fs type for name put here
+  struct statvfs statbuf;
+  int statvfs_successful = 0;
+
+
+  // Make sure the inputs to this function are correct
+  //
+  assert(path);			// path must be specified
+  assert(strlen(path));		// cannot have a zero length
+
+
+  // Resolve all symbolic links in path so that we have a handle
+  // on the name of the actual file to check up on
+  //
+  (void) strncpy(realPath, path, MAXPATHLEN-1);
+  while (1) {
+    if ((len = readlink(realPath, linkname, sizeof (linkname)-1)) < 0)
+	break;
+    linkname[len] = '\0';
+    (void) strncpy(realPath, linkname, MAXPATHLEN-1);
+  }
+
+  // Try and determine where this file is located relative to here
+  //
+
+  for (int i = 0; ; i++)
+  {
+    fsTypeLen = 0;
+
+    switch (i)
+    {
+    case 0:			// first instance -- try statvfs	    
+      statbuf.f_files = 0;
+      if (statvfs (realPath, &statbuf) == -1)
+	  continue;
+      statvfs_successful++;
+      fsTypeLen = strlen(statbuf.f_basetype);
+      (void) strncpy(fsType, statbuf.f_basetype, MAXPATHLEN-1);
+      break;
+
+    case 1:			// second instance -- scan mount table
+      if ( (mfp = fopen(MNTTAB, "r")) == NULL )
+	  continue;
+      mnt = &sysvmnt;
+      while ((getmntent(mfp, mnt)) >= 0) {
+	len = preflen(realPath, mnt->mnt_mountp);
+	if (len >= fsTypeLen) {
+	  fsTypeLen = len;
+	  (void) strncpy(
+			fsType,
+			mnt->mnt_fstype ? mnt->mnt_fstype : "unknown-fstype",
+			MAXPATHLEN-1);
+	}
+      }
+      fclose(mfp);
+      break;
+
+    default:			// run out of major options
+      if (statvfs_successful)	// if statvfs successful, infer results
+	return(statbuf.f_files == -1 ? Dtm_FL_REMOTE : Dtm_FL_LOCAL);
+      return(Dtm_FL_UNKNOWN);
+    }
+
+    // At this point, if fsTypeLen > 0 then we have found a match.
+    // Return the proper Dtm_FL_xxx code according to the type of file system
+    // path object is located on
+    //
+    if (fsTypeLen == 0)			// nothing found??
+      continue;				// nope - try next pass
+    if (!strcmp(fsType, "cachefs"))	// cached from anonymous source?
+      return(Dtm_FL_LOCAL_AND_REMOTE);	// yes: file is local and remote
+    else if (!strcmp(fsType, "nfs"))	// nfs resource?
+      return (Dtm_FL_REMOTE);		// yes: file is remote only
+    else if (!strcmp(fsType, "ufs"))	// ufs type file system?
+      return (Dtm_FL_LOCAL);		// yes: file is local only
+    else if (!strcmp(fsType, "tmpfs"))	// tmpfs local but transient file?
+      return (Dtm_FL_LOCAL);		// yes: file is local
+    else if (!strcmp(fsType, "autofs"))	// automounter mounting point??
+      return (Dtm_FL_REMOTE);		// yes: file is remote
+
+    // no type that we recognize - try next pass
+    //
+  }
+#else
+  int len = (int) strlen(path);
+  return(Dtm_FL_UNKNOWN);
+#endif
+}