WebSVN – HelenOS – Diff – /trunk/uspace/srv/fs/fat/fat_ops.c

 /*
  * Copyright (c) 2007 Jakub Jermar
  * All rights reserved.
+ *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
+ *
  * - Redistributions of source code must retain the above copyright
  *   notice, this list of conditions and the following disclaimer.
  * - Redistributions in binary form must reproduce the above copyright
  *   notice, this list of conditions and the following disclaimer in the
  *   documentation and/or other materials provided with the distribution.
  * - The name of the author may not be used to endorse or promote products
  *   derived from this software without specific prior written permission.
+ *
  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 /** @addtogroup fs
  * @{
  */
 /**
  * @file    fat_ops.c
  * @brief   Implementation of VFS operations for the FAT file system server.
  */
 #include "fat.h"
 #include "../../vfs/vfs.h"
 #include <ipc/ipc.h>
 #include <async.h>
 #include <errno.h>
 #define PLB_GET_CHAR(i)     (plb_ro[(i) % PLB_SIZE])
 #define FAT_NAME_LEN        8
 #define FAT_EXT_LEN     3
 #define FAT_PAD         ' '
 #define FAT_DENTRY_UNUSED   0x00
 #define FAT_DENTRY_E5_ESC   0x05
 #define FAT_DENTRY_DOT      0x2e
 #define FAT_DENTRY_ERASED   0xe5
+/** Compare one component of path to a directory entry.
+ *
+ * @param dentry    Directory entry to compare the path component with.
+ * @param start     Index into PLB where the path component starts.
+ * @param last      Index of the last character of the path in PLB.
+ *
+ * @return      Zero on failure or delta such that (index + delta) %
+ *          PLB_SIZE points to a new path component in PLB.
+ */
-static int match_path_component(fat_dentry_t *dentry, unsigned index,
+static unsigned match_path_component(fat_dentry_t *dentry, unsigned start,
-    size_t len)
+    unsigned last)
+{
+    unsigned cur;   /* current position in PLB */
+    int pos;    /* current position in dentry->name or dentry->ext */
+    bool name_processed = false;
+    bool dot_processed = false;
+    bool ext_processed = false;
+    if (last < start)
+        last += PLB_SIZE;
+    for (pos = 0, cur = start; (cur <= last) && (PLB_GET_CHAR(cur) != '/');
+        pos++, cur++) {
+        if (!name_processed) {
+            if ((pos == FAT_NAME_LEN - 1) ||
+                (dentry->name[pos + 1] == FAT_PAD)) {
+                    /* this is the last character in name */
+                name_processed = true;
+            }
+            if (dentry->name[0] == FAT_PAD) {
+                /* name is empty */
+                name_processed = true;
+            } else if ((pos == 0) && (dentry->name[pos] ==
+                FAT_DENTRY_E5_ESC)) {
+                if (PLB_GET_CHAR(cur) == 0xe5)
+                    continue;
+                else
+                    return 0;   /* character mismatch */
+            } else {
+                if (PLB_GET_CHAR(cur) == dentry->name[pos])
+                    continue;
+                else
+                    return 0;   /* character mismatch */
+            }
+        }
+        if (!dot_processed) {
+            dot_processed = true;
+            pos = -1;
+            if (PLB_GET_CHAR(cur) != '.')
+                return 0;
+            continue;
+        }
+        if (!ext_processed) {
+            if ((pos == FAT_EXT_LEN - 1) ||
+                (dentry->ext[pos + 1] == FAT_PAD)) {
+                /* this is the last character in ext */
+                ext_processed = true;
+            }
+            if (dentry->ext[0] == FAT_PAD) {
+                /* ext is empty; the match will fail */
+                ext_processed = true;
+            } else if (PLB_GET_CHAR(cur) == dentry->ext[pos]) {
+                continue;
+            } else {
+                /* character mismatch */
+                return 0;
+            }
+        }
+        return 0;   /* extra characters in the component */
+    }
+    if (ext_processed || (name_processed && dentry->ext[0] == FAT_PAD))
+        return cur - start;
+    else
+        return 0;
+}
 void fat_lookup(ipc_callid_t rid, ipc_call_t *request)
+{
     int first = IPC_GET_ARG1(*request);
     int second = IPC_GET_ARG2(*request);
     int dev_handle = IPC_GET_ARG3(*request);
+}
 /**
  * @}
  */

Subversion Repositories HelenOS

(root)/trunk/uspace/srv/fs/fat/fat_ops.c @ 4680 – Rev 2638 → 2639