fix(rename,unlink): fix STATUS_ACCESS_DENIED by passing shareAccess see #18 (#21)

Related to #18 

This sets correct ShareAccess values for rename and unlink requests.
See https://msdn.microsoft.com/en-us/library/cc246502.aspx ShareAccess.

ShareAcess was always set to 0x00. For rename and delete requests
it is required to include the 0x04 flag.

lib/api/rename.js

 var BigInt = require('../tools/bigint');
 var SMB2Request = require('../tools/smb2-forge').request;
-var FILE_OPEN = require('../structures/constants').FILE_OPEN;
+var constants = require('../structures/constants');
 
 /*
  * rename
@@ -31,7 +31,7 @@ module.exports = function rename(oldPath, newPath, options, cb) {
     if (err)
       SMB2Request(
         'create',
-        { path: oldPath, createDisposition: FILE_OPEN },
+        { path: oldPath, createDisposition: constants.FILE_OPEN, shareAccess: constants.FILE_SHARE_DELETE },
         connection,
         function(err, file) {
           if (err) cb && cb(err);

lib/api/unlink.js

 var SMB2Forge = require('../tools/smb2-forge');
 var SMB2Request = SMB2Forge.request;
 var BigInt = require('../tools/bigint');
-
+var constants = require('../structures/constants');
 /*
  * unlink
  * ======
@@ -19,7 +19,7 @@ module.exports = function unlink(path, cb) {
   var connection = this;
 
   // SMB2 open file
-  SMB2Request('create', { path: path }, connection, function(err, file) {
+  SMB2Request('create', { path: path, shareAccess: constants.FILE_SHARE_DELETE }, connection, function(err, file) {
     if (err) cb && cb(err);
     // SMB2 query directory
     else

lib/messages/create.js

@@ -20,6 +20,7 @@ module.exports = message({
   generate: function(connection, params) {
     var buffer = Buffer.from(params.path, 'ucs2');
     var createDisposition = params.createDisposition;
+    var shareAccess = params.shareAccess;
 
     /* See: https://msdn.microsoft.com/en-us/library/cc246502.aspx
        6 values for CreateDisposition. */
@@ -27,6 +28,12 @@ module.exports = message({
       createDisposition = constants.FILE_OVERWRITE_IF;
     }
 
+    /* See: https://msdn.microsoft.com/en-us/library/cc246502.aspx
+       7 possible values for ShareAccess. */
+    if (!(shareAccess >= 0 && shareAccess <= 7)) {
+      shareAccess = constants.FILE_SHARE_NONE;
+    }
+
     return new SMB2Message({
       headers: {
         Command: 'CREATE',
@@ -38,7 +45,7 @@ module.exports = message({
         Buffer: buffer,
         DesiredAccess: desiredAccess,
         FileAttributes: 0x00000080,
-        ShareAccess: 0x00000000,
+        ShareAccess: shareAccess,
         CreateDisposition: createDisposition,
         CreateOptions: 0x00000044,
         NameOffset: 0x0078,

lib/structures/constants.js

@@ -14,6 +14,11 @@ module.exports = {
   MAX_READ_LENGTH: 0x00010000,
   MAX_WRITE_LENGTH: 0x00010000 - 0x71,
 
+  FILE_SHARE_NONE: 0x00000000,
+  FILE_SHARE_READ: 0x00000001,
+  FILE_SHARE_WRITE: 0x00000002,
+  FILE_SHARE_DELETE: 0x00000004,
+
   /**
    * 2.2.13.1.1 SMB2 File_Pipe_Printer_Access_Mask
    * https://docs.microsoft.com/en-us/openspecs/windows_protocols/ms-smb2/77b36d0f-6016-458a-a7a0-0f4a72ae1534