Windows: Add GetFileInformationByHandleEx to fs_InAFS

If available on the operating system, use
GetFileInformationByHandleEx to translate the path into
the file system normalized form.  This permits paths that
cross NTFS reparse points to be successfully evaluated as
being in afs.   For example:

  c:\afs -> \\afs\all

GetFileInformationByHandleEx is integrated into Vista and
Server 2008 and above.

Change-Id: I57443b01c753f12665aaac5718f639e389e2e822
Reviewed-on: http://gerrit.openafs.org/4778
Reviewed-by: Jeffrey Altman <jaltman@openafs.org>
Reviewed-by: Derrick Brashear <shadow@dementia.org>
Tested-by: BuildBot <buildbot@rampaginggeek.com>

diff --git a/src/WINNT/afsd/fs_utils.c b/src/WINNT/afsd/fs_utils.c
index 7fb5d72..1e44de9 100644 (file)
--- a/src/WINNT/afsd/fs_utils.c
+++ b/src/WINNT/afsd/fs_utils.c
@@ -250,15 +250,98 @@ fs_GetParent(char *apath)
     return tspace;
 }
 
+#if (_WINNT_WIN32 < 0x0600)
+typedef struct FILE_NAME_INFO {
+    DWORD FileNameLength;
+    WCHAR FileName[1];
+} FILE_NAME_INFO, *PFILE_NAME_INFO;
+
+typedef enum _FILE_INFO_BY_HANDLE_CLASS {
+    FileNameInfo = 2
+} FILE_INFO_BY_HANDLE_CLASS, *PFILE_INFO_BY_HANDLE_CLASS;
+
+typedef BOOL
+(WINAPI *
+LPFN_GetFileInformationByHandleEx)(
+    __in  HANDLE hFile,
+    __in  FILE_INFO_BY_HANDLE_CLASS FileInformationClass,
+    __out LPVOID lpFileInformation,
+    __in  DWORD dwBufferSize
+);
+#endif
+
+static long
+GetFileSystemNameInfo(const char *fileNamep, char *outNamep, size_t outSize)
+{
+    HANDLE hf;
+    union {
+        FILE_NAME_INFO nameInfo;
+        CHAR               buffer[2048];
+    } u;
+    DWORD rc;
+#if (_WIN32_WINNT < 0x0600)
+    HANDLE hKernel32;
+    static LPFN_GetFileInformationByHandleEx GetFileInformationByHandleEx = NULL;
+
+    if (!GetFileInformationByHandleEx) {
+        hKernel32 = GetModuleHandle("kernel32.dll");   /* no refcount increase */
+        GetFileInformationByHandleEx = (LPFN_GetFileInformationByHandleEx)GetProcAddress(hKernel32, "GetFileInformationByHandleEx");
+    }
+#endif
+
+    if (!GetFileInformationByHandleEx)
+        return -1;
+
+    hf = CreateFile( fileNamep,
+                     GENERIC_READ,
+                     FILE_SHARE_READ|FILE_SHARE_WRITE|FILE_SHARE_DELETE,
+                     NULL,
+                     OPEN_EXISTING,
+                     FILE_FLAG_BACKUP_SEMANTICS,
+                     NULL
+                     );
+    if (hf == INVALID_HANDLE_VALUE)
+        return -1;
+
+    rc = GetFileInformationByHandleEx( hf, FileNameInfo, &u, sizeof(u));
+    CloseHandle(hf);
+    if (rc == FALSE)
+        return -1;
+
+    rc = WideCharToMultiByte(CP_UTF8, 0,
+                              u.nameInfo.FileName, u.nameInfo.FileNameLength,
+                              outNamep, outSize,
+                              NULL, FALSE);
+    if (rc == 0) /* failure */
+        return -1;
+
+    if (outNamep[0] == '\\' &&
+         outNamep[u.nameInfo.FileNameLength/2 - 1] == '\\')
+               outNamep[u.nameInfo.FileNameLength/2 - 1] = 0;
+    else
+        outNamep[min(u.nameInfo.FileNameLength/2, outSize)] = 0;       /* make sure we are nul terminated */
+
+    return 0;
+}
+
 /* this function returns TRUE (1) if the file is in AFS, otherwise false (0) */
 int
 fs_InAFS(char *apath)
 {
+    char fsname[MAX_PATH+2]="\\";
     struct ViceIoctl blob;
     cm_ioctlQueryOptions_t options;
     cm_fid_t fid;
     afs_int32 code;
 
+    /*
+     * If the operating system supports the name information query
+     * use it to resolve the full file path.  This will take care
+     * of any mappings, ntfs junctions, etc.
+     */
+    if (GetFileSystemNameInfo(apath, &fsname[1], sizeof(fsname)-1) == 0)
+        apath = fsname;
+
     memset(&options, 0, sizeof(options));
     options.size = sizeof(options);
     options.field_flags |= CM_IOCTL_QOPTS_FIELD_LITERAL;