We now support symlink-like objects on windows

Support was added for the following types of symlinks:
- Symlinks on Files
- Symlinks on Directories
- Junction Points

These are implemented in windows as Reparse Points.

All these objects are treated like ordinary symlinks
(FT_LNK) in bareos, also Junction Points and Symlinks on
Directories which are directories in windows logic.

The Information on what kind of symlink-like object we have
is stored in the st_rdev member of the stat information.

There we have now
- FILE_ATTRIBUTES_JUNCTION_POINT
- FILE_ATTRIBUTES_SYMBOLIC_LINK

During Backup, the function "get_symlink_data" gets the information
where the symlink/junction/volume mount points points to.

During restore, the function "symlink" creates the symlink-like object.
To be able to determine what kind of "symlink" needs to be created, it
also gets the st_rdev information.

Depending on what kind of symlink it needs to create it either calls
the windows api function "CreateSymbolicLink" or the self-implemented
Function "CreateJunction"

The symlink target is not altered during restore, even if it is
restored with a prefix (where), because this makes absolute links
unusable.

Fixes #314: On Windows 2008 and Windows 2012 the junction points / links
            are not backed up properly

Signed-off-by: Philipp Storz <philipp.storz@bareos.com>
Signed-off-by: Marco van Wieringen <marco.van.wieringen@bareos.com>

src/filed/backup.c

@@ -732,9 +732,12 @@ int save_file(JCR *jcr, FF_PKT *ff_pkt, bool top_level)
 #else
       do_read = ff_pkt->statp.st_size > 0;
 #endif
-   } else if (ff_pkt->type == FT_RAW || ff_pkt->type == FT_FIFO ||
-              ff_pkt->type == FT_REPARSE || ff_pkt->type == FT_JUNCTION ||
-         (!is_portable_backup(&ff_pkt->bfd) && ff_pkt->type == FT_DIREND)) {
+   } else if (ff_pkt->type == FT_RAW ||
+              ff_pkt->type == FT_FIFO ||
+              ff_pkt->type == FT_REPARSE ||
+              ff_pkt->type == FT_JUNCTION ||
+             (!is_portable_backup(&ff_pkt->bfd) &&
+              ff_pkt->type == FT_DIREND)) {
       do_read = true;
    }
 
@@ -1357,6 +1360,7 @@ bool encode_and_send_attributes(JCR *jcr, FF_PKT *ff_pkt, int &data_stream)
       strip_path(ff_pkt);
    }
    switch (ff_pkt->type) {
+   case FT_JUNCTION:
    case FT_LNK:
    case FT_LNKSAVED:
       Dmsg3(300, "Link %d %s to %s\n", jcr->JobFiles, ff_pkt->fname, ff_pkt->link);
@@ -1366,7 +1370,6 @@ bool encode_and_send_attributes(JCR *jcr, FF_PKT *ff_pkt, int &data_stream)
       break;
    case FT_DIREND:
    case FT_REPARSE:
-   case FT_JUNCTION:
       /* Here link is the canonical filename (i.e. with trailing slash) */
       status = sd->fsend("%ld %d %s%c%s%c%c%s%c%u%c", jcr->JobFiles,
                          ff_pkt->type, ff_pkt->link, 0, attribs.c_str(), 0, 0,

src/findlib/create_file.c

@@ -41,7 +41,6 @@
 static int separate_path_and_file(JCR *jcr, char *fname, char *ofile);
 static int path_already_seen(JCR *jcr, char *path, int pnl);
 
-
 /*
  * Create the file, or the directory
  *
@@ -306,15 +305,6 @@ int create_file(JCR *jcr, ATTR *attr, BFILE *bfd, int replace)
          Dmsg1(400, "FT_SPEC %s\n", attr->ofname);
          return CF_CREATED;
 
-      case FT_LNK:
-         Dmsg2(130, "FT_LNK should restore: %s -> %s\n", attr->ofname, attr->olname);
-         if (symlink(attr->olname, attr->ofname) != 0 && errno != EEXIST) {
-            berrno be;
-            Qmsg3(jcr, M_ERROR, 0, _("Could not symlink %s -> %s: ERR=%s\n"),
-                  attr->ofname, attr->olname, be.bstrerror());
-            return CF_ERROR;
-         }
-         return CF_CREATED;
 
       case FT_LNKSAVED:                  /* Hard linked, file already saved */
          Dmsg2(130, "Hard link %s => %s\n", attr->ofname, attr->olname);
@@ -366,6 +356,45 @@ int create_file(JCR *jcr, ATTR *attr, BFILE *bfd, int replace)
 
          }
          return CF_CREATED;
+
+#endif /* HAVE_WIN32 */
+#ifdef HAVE_WIN32
+      case FT_LNK:
+         /*
+          * Handle Windows Symlink-Like Reparse Points
+          * - Directory Symlinks
+          * - File Symlinks
+          * - Volume Mount Points
+          * - Junctions
+          */
+         Dmsg2(130, "FT_LNK should restore: %s -> %s\n", attr->ofname, attr->olname);
+         if (attr->statp.st_rdev & FILE_ATTRIBUTE_VOLUME_MOUNT_POINT) {
+            /*
+             * We do not restore volume mount points
+             */
+            Dmsg0(130, "Skipping Volume Mount Point\n");
+            return CF_SKIP;
+         }
+         if (win32_symlink(attr->olname, attr->ofname, attr->statp.st_rdev) != 0 && errno != EEXIST) {
+            berrno be;
+            Qmsg3(jcr, M_ERROR, 0, _("Could not symlink %s -> %s: ERR=%s\n"),
+                  attr->ofname, attr->olname, be.bstrerror());
+            return CF_ERROR;
+         }
+         return CF_CREATED;
+#else
+      case FT_LNK:
+         /*
+          * Unix/Linux symlink handling
+          */
+         Dmsg2(130, "FT_LNK should restore: %s -> %s\n", attr->ofname, attr->olname);
+         if (symlink(attr->olname, attr->ofname) != 0 && errno != EEXIST) {
+            berrno be;
+            Qmsg3(jcr, M_ERROR, 0, _("Could not symlink %s -> %s: ERR=%s\n"),
+                  attr->ofname, attr->olname, be.bstrerror());
+            return CF_ERROR;
+         }
+         return CF_CREATED;
 #endif
       } /* End inner switch */
 
@@ -381,7 +410,6 @@ int create_file(JCR *jcr, ATTR *attr, BFILE *bfd, int replace)
       if (!makepath(attr, attr->ofname, new_mode, parent_mode, uid, gid, 0)) {
          return CF_ERROR;
       }
-
       /*
        * If we are using the Win32 Backup API, we open the directory so
        * that the security info will be read and saved.

src/findlib/find_one.c

@@ -590,9 +590,7 @@ static inline int process_directory(JCR *jcr, FF_PKT *ff_pkt,
    }
 
 #if defined(HAVE_WIN32)
-   if (ff_pkt->statp.st_rdev & FILE_ATTRIBUTES_JUNCTION_POINT) {
-      ff_pkt->type = FT_JUNCTION;
-   } else if (ff_pkt->statp.st_rdev & FILE_ATTRIBUTE_REPARSE_POINT) {
+   if (ff_pkt->statp.st_rdev & FILE_ATTRIBUTE_REPARSE_POINT) {
       ff_pkt->type = FT_REPARSE;
    }
 #endif
@@ -607,9 +605,9 @@ static inline int process_directory(JCR *jcr, FF_PKT *ff_pkt,
     */
    rtn_stat = handle_file(jcr, ff_pkt, top_level);
    if (rtn_stat < 1 ||
-       ff_pkt->type == FT_REPARSE ||
-       ff_pkt->type == FT_JUNCTION) {   /* ignore or error status */
+       ff_pkt->type == FT_REPARSE)  {   /* ignore or error status */
       free(link);
+
       return rtn_stat;
    }
 

src/findlib/mkpath.c

@@ -183,12 +183,8 @@ static void set_own_mod(ATTR *attr, char *path, uid_t owner, gid_t group, mode_t
 
 /*
  * mode is the mode bits to use in creating a new directory
- *
- * parent_mode are the parent's modes if we need to create parent
- *    directories.
- *
+ * parent_mode are the parent's modes if we need to create parent directories.
  * owner and group are to set on any created dirs
- *
  * keep_dir_modes if set means don't change mode bits if dir exists
  */
 bool makepath(ATTR *attr, const char *apath, mode_t mode, mode_t parent_mode,
@@ -227,17 +223,19 @@ bool makepath(ATTR *attr, const char *apath, mode_t mode, mode_t parent_mode,
    strip_trailing_slashes(path);
    /*
     * Now for one of the complexities. If we are not running as root,
-    *  then if the parent_mode does not have wx user perms, or we are
-    *  setting the userid or group, and the parent_mode has setuid, setgid,
-    *  or sticky bits, we must create the dir with open permissions, then
-    *  go back and patch all the dirs up with the correct perms.
+    * then if the parent_mode does not have wx user perms, or we are
+    * setting the userid or group, and the parent_mode has setuid, setgid,
+    * or sticky bits, we must create the dir with open permissions, then
+    * go back and patch all the dirs up with the correct perms.
     * Solution, set everything to 0777, then go back and reset them at the
-    *  end.
+    * end.
     */
    tmode = 0777;
 
 #if defined(HAVE_WIN32)
-   /* Validate drive letter */
+   /*
+    * Validate drive letter
+    */
    if (path[1] == ':') {
       char drive[4] = "X:\\";
 
@@ -263,7 +261,9 @@ bool makepath(ATTR *attr, const char *apath, mode_t mode, mode_t parent_mode,
    p = path;
 #endif
 
-   /* Skip leading slash(es) */
+   /*
+    * Skip leading slash(es)
+    */
    while (IsPathSeparator(*p)) {
       p++;
    }
@@ -282,21 +282,30 @@ bool makepath(ATTR *attr, const char *apath, mode_t mode, mode_t parent_mode,
          p++;
       }
    }
-   /* Create final component */
-   if (!makedir(jcr, path, tmode, &created)) {
-      goto bail_out;
+   /*
+    * Create final component if not a junction/symlink
+    */
+   if(attr->type != FT_JUNCTION ){
+      if (!makedir(jcr, path, tmode, &created)) {
+         goto bail_out;
+      }
    }
+
    if (ndir < max_dirs) {
       new_dir[ndir++] = created;
    }
    if (ndir >= max_dirs) {
       Jmsg0(jcr, M_WARNING, 0, _("Too many subdirectories. Some permissions not reset.\n"));
    }
 
-   /* Now set the proper owner and modes */
+   /*
+    * Now set the proper owner and modes
+    */
 #if defined(HAVE_WIN32)
 
-   /* Don't propagate the hidden attribute to parent directories */
+   /*
+    * Don't propagate the hidden attribute to parent directories
+    */
    parent_mode &= ~S_ISVTX;
 
    if (path[1] == ':') {
@@ -307,7 +316,9 @@ bool makepath(ATTR *attr, const char *apath, mode_t mode, mode_t parent_mode,
 #else
    p = path;
 #endif
-   /* Skip leading slash(es) */
+   /*
+    * Skip leading slash(es)
+    */
    while (IsPathSeparator(*p)) {
       p++;
    }
@@ -324,7 +335,9 @@ bool makepath(ATTR *attr, const char *apath, mode_t mode, mode_t parent_mode,
       }
    }
 
-   /* Set for final component */
+   /*
+    * Set for final component
+    */
    if (i < ndir && new_dir[i++]) {
       set_own_mod(attr, path, owner, group, mode);
    }

src/lib/attr.c

@@ -219,12 +219,6 @@ void build_attr_output_fnames(JCR *jcr, ATTR *attr)
             attr->olname[0] = 0;
             add_link = false;
          }
-
-#if defined(HAVE_WIN32)
-         if (attr->lname[1] == ':') {
-            attr->lname[1] = '/';    /* turn : into / */
-         }
-#endif
          fn = attr->lname;       /* take whole name */
          /* Ensure where is terminated with a slash */
          if (add_link &&