[svn-r17939] Description:

	Handle external links from symlinked files by adding another check to
look for "child" files for links from the actual location of the "parent" file,
instead of from the location of the symlink.

Tested on:
        FreeBSD/32 6.3 (duty) in debug mode
        FreeBSD/64 6.3 (liberty) w/C++ & FORTRAN, in debug mode
        Linux/32 2.6 (jam) w/PGI compilers, w/default API=1.8.x,
                w/C++ & FORTRAN, w/threadsafe, in debug mode
        Linux/64-amd64 2.6 (smirom) w/Intel compilers, w/default API=1.6.x,
                w/C++ & FORTRAN, in production mode
        Solaris/32 2.10 (linew) w/deprecated symbols disabled, w/C++ & FORTRAN,
                w/szip filter, in production mode
        Linux/64-ia64 2.6 (cobalt) w/Intel compilers, w/C++ & FORTRAN,
                in production mode
        Linux/64-ia64 2.4 (tg-login3) w/parallel, w/FORTRAN, in debug mode
        Linux/64-amd64 2.6 (abe) w/parallel, w/FORTRAN, in production mode
        Mac OS X/32 10.6.2 (amazon) in debug mode
        Mac OS X/32 10.6.2 (amazon) w/C++ & FORTRAN, w/threadsafe,
                in production mode

1 files changed, 117 insertions, 81 deletions

diff --git a/src/H5F.c b/src/H5F.c
index 0195b5a..7e9a32e 100644
--- a/src/H5F.c
+++ b/src/H5F.c
@@ -67,7 +67,6 @@ typedef struct H5F_olist_t {
 /* PRIVATE PROTOTYPES */
 static size_t H5F_get_objects(const H5F_t *f, unsigned types, size_t max_objs, hid_t *obj_id_list, hbool_t app_ref);
 static int H5F_get_objects_cb(void *obj_ptr, hid_t obj_id, void *key);
-static herr_t H5F_get_vfd_handle(const H5F_t *file, hid_t fapl, void** file_handle);
 static H5F_t *H5F_new(H5F_file_t *shared, hid_t fcpl_id, hid_t fapl_id,
                       H5FD_t *lf);
 static herr_t H5F_dest(H5F_t *f, hid_t dxpl_id);
@@ -705,21 +704,18 @@ done:
  *              driver.
  *
  * Return:      Success:        non-negative value.
- *
- *              Failture:       negative.
+ *              Failure:        negative.
  *
  * Programmer:  Raymond Lu
  *              Sep. 16, 2002
  *
- * Modification:
- *
  *-------------------------------------------------------------------------
  */
 herr_t
 H5Fget_vfd_handle(hid_t file_id, hid_t fapl, void **file_handle)
 {
     H5F_t               *file;          /* File to query */
-    herr_t              ret_value;      /* Return value */
+    herr_t              ret_value = SUCCEED;      /* Return value */
 
     FUNC_ENTER_API(H5Fget_vfd_handle, FAIL)
     H5TRACE3("e", "ii**x", file_id, fapl, file_handle);
@@ -732,7 +728,9 @@ H5Fget_vfd_handle(hid_t file_id, hid_t fapl, void **file_handle)
     if(NULL == (file = (H5F_t *)H5I_object_verify(file_id, H5I_FILE)))
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "not a file id")
 
-    ret_value = H5F_get_vfd_handle(file, fapl, file_handle);
+    /* Retrieve the VFD handle for the file */
+    if(H5F_get_vfd_handle(file, fapl, file_handle) < 0)
+        HGOTO_ERROR(H5E_FILE, H5E_CANTGET, FAIL, "can't retrieve VFD handle")
 
 done:
     FUNC_LEAVE_API(ret_value)
@@ -740,39 +738,6 @@ done:
 
 
 /*-------------------------------------------------------------------------
- * Function:    H5F_get_vfd_handle
- *
- * Purpose:     Returns a pointer to the file handle of the low-level file
- *              driver.  This is the private function for H5Fget_vfd_handle.
- *
- * Return:      Success:        Non-negative.
- *
- *              Failture:       negative.
- *
- * Programmer:  Raymond Lu
- *              Sep. 16, 2002
- *
- * Modification:
- *
- *-------------------------------------------------------------------------
- */
-static herr_t
-H5F_get_vfd_handle(const H5F_t *file, hid_t fapl, void**file_handle)
-{
-    herr_t ret_value;
-
-    FUNC_ENTER_NOAPI_NOINIT(H5F_get_vfd_handle)
-
-    assert(file_handle);
-    if((ret_value=H5FD_get_vfd_handle(file->shared->lf, fapl, file_handle)) < 0)
-        HGOTO_ERROR(H5E_FILE, H5E_CANTGET, FAIL, "can't get file handle for file driver")
-
-done:
-    FUNC_LEAVE_NOAPI(ret_value)
-}
-
-
-/*-------------------------------------------------------------------------
  * Function:	H5Fis_hdf5
  *
  * Purpose:	Check the file signature to detect an HDF5 file.
@@ -1118,7 +1083,8 @@ H5F_dest(H5F_t *f, hid_t dxpl_id)
     }
 
     /* Free the non-shared part of the file */
-    f->name = (char *)H5MM_xfree(f->name);
+    f->open_name = (char *)H5MM_xfree(f->open_name);
+    f->actual_name = (char *)H5MM_xfree(f->actual_name);
     f->extpath = (char *)H5MM_xfree(f->extpath);
     if(H5FO_top_dest(f) < 0)
         HDONE_ERROR(H5E_FILE, H5E_CANTINIT, FAIL, "problems closing file")
@@ -1168,7 +1134,6 @@ H5F_dest(H5F_t *f, hid_t dxpl_id)
  *		cause the default file access parameters to be used.
  *
  * Return:	Success:	A new file pointer.
- *
  *		Failure:	NULL
  *
  * Programmer:	Robb Matzke
@@ -1198,7 +1163,7 @@ H5F_open(const char *name, unsigned flags, hid_t fcpl_id, hid_t fapl_id, hid_t d
      * Otherwise it is the application's responsibility to never open the
      * same file more than once at a time.
      */
-    if((drvr = H5FD_get_class(fapl_id)) == NULL)
+    if(NULL == (drvr = H5FD_get_class(fapl_id)))
         HGOTO_ERROR(H5E_FILE, H5E_CANTGET, NULL, "unable to retrieve VFL class")
 
     /*
@@ -1284,7 +1249,7 @@ H5F_open(const char *name, unsigned flags, hid_t fcpl_id, hid_t fapl_id, hid_t d
      * file can be accessed through the C library.
      */
     file->intent = flags;
-    file->name = H5MM_xstrdup(name);
+    file->open_name = H5MM_xstrdup(name);
 
     /*
      * Read or write the file superblock, depending on whether the file is
@@ -1342,10 +1307,14 @@ H5F_open(const char *name, unsigned flags, hid_t fcpl_id, hid_t fapl_id, hid_t d
             HGOTO_ERROR(H5E_FILE, H5E_CANTINIT, NULL, "file close degree doesn't match")
     } /* end if */
 
-    /* formulate the absolute path for later search of target file for external link */
-    if (H5_build_extpath(name, &file->extpath) < 0)
+    /* Formulate the absolute path for later search of target file for external links */
+    if(H5_build_extpath(name, &file->extpath) < 0)
 	HGOTO_ERROR(H5E_FILE, H5E_CANTINIT, NULL, "unable to build extpath")
 
+    /* Formulate the actual file name, after following symlinks, etc. */
+    if(H5F_build_actual_name(file, name, &file->actual_name) < 0)
+	HGOTO_ERROR(H5E_FILE, H5E_CANTINIT, NULL, "unable to build actual name")
+
     /* Success */
     ret_value = file;
 
@@ -2007,8 +1976,9 @@ H5Freopen(hid_t file_id)
     /* Keep old file's read/write intent in new file */
     new_file->intent = old_file->intent;
 
-    /* Duplicate old file's name */
-    new_file->name = H5MM_xstrdup(old_file->name);
+    /* Duplicate old file's names */
+    new_file->open_name = H5MM_xstrdup(old_file->open_name);
+    new_file->actual_name = H5MM_xstrdup(old_file->actual_name);
 
     if((ret_value = H5I_register(H5I_FILE, new_file, TRUE)) < 0)
 	HGOTO_ERROR(H5E_ATOM, H5E_CANTREGISTER, FAIL, "unable to atomize file handle")
@@ -2109,37 +2079,6 @@ done:
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5F_get_eoa
- *
- * Purpose:	Quick and dirty routine to retrieve the file's 'eoa' value
- *
- * Return:	Non-negative on success/Negative on failure
- *
- * Programmer:	Quincey Koziol <koziol@ncsa.uiuc.edu>
- *		June 1, 2004
- *
- *-------------------------------------------------------------------------
- */
-haddr_t
-H5F_get_eoa(const H5F_t *f, H5FD_mem_t type)
-{
-    haddr_t	ret_value;
-
-    FUNC_ENTER_NOAPI(H5F_get_eoa, HADDR_UNDEF)
-
-    HDassert(f);
-    HDassert(f->shared);
-
-    /* Dispatch to driver */
-    if(HADDR_UNDEF == (ret_value = H5FD_get_eoa(f->shared->lf, type)))
-	HGOTO_ERROR(H5E_VFL, H5E_CANTINIT, HADDR_UNDEF, "driver get_eoa request failed")
-
-done:
-    FUNC_LEAVE_NOAPI(ret_value)
-} /* end H5F_get_eoa() */
-
-
-/*-------------------------------------------------------------------------
  * Function:	H5F_incr_nopen_objs
  *
  * Purpose:	Increment the number of open objects for a file.
@@ -2194,6 +2133,100 @@ H5F_decr_nopen_objs(H5F_t *f)
 
 
 /*-------------------------------------------------------------------------
+ * Function:	H5F_build_actual_name
+ *
+ * Purpose:	Retrieve the name of a file, after following symlinks, etc.
+ *
+ * Note:	Currently only working for "POSIX I/O compatible" VFDs
+ *
+ * Return:	Success:        0
+ *		Failure:	-1
+ *
+ * Programmer:	Quincey Koziol
+ *		November 25, 2009
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5F_build_actual_name(const H5F_t *f, const char *name, char **actual_name/*out*/)
+{
+    herr_t      ret_value = SUCCEED;    /* Return value */
+
+    FUNC_ENTER_NOAPI_NOINIT(H5F_build_actual_name)
+
+    /* Sanity check */
+    HDassert(f);
+    HDassert(name);
+    HDassert(actual_name);
+
+    /* Clear actual name pointer to begin with */
+    *actual_name = NULL;
+
+/* Assume that if the OS can't create symlinks, that we don't need to worry
+ *      about resolving them either. -QAK
+ */
+#ifdef H5_HAVE_SYMLINK
+    /* Check for POSIX I/O compatible file handle */
+    if(H5F_HAS_FEATURE(f, H5FD_FEAT_POSIX_COMPAT_HANDLE)) {
+        h5_stat_t lst;   /* Stat info from lstat() call */
+
+        /* Call lstat() on the file's name */
+        if(HDlstat(name, &lst) < 0)
+            HGOTO_ERROR(H5E_FILE, H5E_CANTGET, FAIL, "can't retrieve stat info for file")
+
+        /* Check for symbolic link */
+        if(S_IFLNK == (lst.st_mode & S_IFMT)) {
+            int *fd;                    /* POSIX I/O file descriptor */
+            h5_stat_t st;               /* Stat info from stat() call */
+            h5_stat_t fst;              /* Stat info from fstat() call */
+            char realname[PATH_MAX];    /* Fully resolved path name of file */
+
+            /* Perform a sanity check that the file or link wasn't switched
+             * between when we opened it and when we called lstat().  This is
+             * according to the security best practices for lstat() documented
+             * here: https://www.securecoding.cert.org/confluence/display/seccode/POS35-C.+Avoid+race+conditions+while+checking+for+the+existence+of+a+symbolic+link
+             */
+
+            /* Retrieve the file handle */
+            if(H5F_get_vfd_handle(f, H5P_DEFAULT, (void **)&fd) < 0)
+                HGOTO_ERROR(H5E_FILE, H5E_CANTGET, FAIL, "can't retrieve POSIX file descriptor")
+
+            /* Stat the filename we're resolving */
+            if(HDstat(name, &st) < 0)
+                HSYS_GOTO_ERROR(H5E_FILE, H5E_BADFILE, FAIL, "unable to stat file")
+
+            /* Stat the file we opened */
+            if(HDfstat(*fd, &fst) < 0)
+                HSYS_GOTO_ERROR(H5E_FILE, H5E_BADFILE, FAIL, "unable to fstat file")
+
+            /* Verify that the files are really the same */
+            if(st.st_mode != fst.st_mode || st.st_ino != fst.st_ino || st.st_dev != fst.st_dev)
+                HGOTO_ERROR(H5E_FILE, H5E_BADVALUE, FAIL, "files' st_ino or st_dev fields changed!")
+
+            /* Get the resolved path for the file name */
+            if(NULL == HDrealpath(name, realname))
+                HGOTO_ERROR(H5E_FILE, H5E_CANTGET, FAIL, "can't retrieve real path for file")
+
+            /* Duplicate the resolved path for the file name */
+            if(NULL == (*actual_name = (char *)H5MM_strdup(realname)))
+                HGOTO_ERROR(H5E_FILE, H5E_CANTALLOC, FAIL, "can't duplicate real path")
+        } /* end if */
+    } /* end if */
+#endif /* H5_HAVE_SYMLINK */
+
+    /* Check if we've resolved the file's name */
+    if(NULL == *actual_name) {
+        /* Just duplicate the name used to open the file */
+        if(NULL == (*actual_name = (char *)H5MM_strdup(name)))
+            HGOTO_ERROR(H5E_FILE, H5E_CANTALLOC, FAIL, "can't duplicate open name")
+    } /* end else */
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5F_build_actual_name() */
+
+
+/*-------------------------------------------------------------------------
  * Function:	H5F_addr_encode_len
  *
  * Purpose:	Encodes an address into the buffer pointed to by *PP and
@@ -2729,6 +2762,9 @@ done:
  *              If an error occurs then the buffer pointed to by `name' (NULL or non-NULL)
  *              is unchanged and the function returns a negative value.
  *
+ * Note:	This routine returns the name that was used to open the file,
+ *		not the actual name after resolving symlinks, etc.
+ *
  * Return:      Success:        The length of the file name
  *              Failure:        Negative
  *
@@ -2764,10 +2800,10 @@ H5Fget_name(hid_t obj_id, char *name/*out*/, size_t size)
         f = loc.oloc->file;
     } /* end else */
 
-    len = HDstrlen(f->name);
+    len = HDstrlen(H5F_OPEN_NAME(f));
 
     if(name) {
-        HDstrncpy(name, f->name, MIN(len+1,size));
+        HDstrncpy(name, H5F_OPEN_NAME(f), MIN(len + 1,size));
         if(len >= size)
             name[size-1]='\0';
     } /* end if */