# CORS (Cross-Origin Resource Sharing) { #cors-cross-origin-resource-sharing }

<a href="https://developer.mozilla.org/en-US/docs/Web/HTTP/CORS" class="external-link" target="_blank">CORS or "Cross-Origin Resource Sharing"</a> refers to the situations when a frontend running in a browser has JavaScript code that communicates with a backend, and the backend is in a different "origin" than the frontend.

## Origin { #origin }

    }

    SmbFileInputStream(final SmbFile file, final int openFlags, final int access, final int sharing, final boolean unshared)
            throws SmbException {
        this.file = file;
        this.unsharedFile = unshared;
        this.openFlags = openFlags;
        this.access = access;
        this.sharing = sharing;

        try (SmbTreeHandleInternal th = file.ensureTreeConnected()) {
            this.smb2 = th.isSMB2();

But if you have custom headers that you want a client in a browser to be able to see, you need to add them to your CORS configurations ([CORS (Cross-Origin Resource Sharing)](cors.md){.internal-link target=_blank}) using the parameter `expose_headers` documented in <a href="https://www.starlette.io/middleware/#corsmiddleware" class="external-link" target="_blank">Starlette's CORS docs</a>.

///

                    this.handle = this.pipe.openUnshared(this.openFlags, this.access, this.sharing, SmbConstants.ATTR_NORMAL, 0);
                } else {
                    // at least on samba, SmbComOpenAndX fails without the pipe prefix
                    this.handle = this.pipe.openUnshared("\\pipe" + getUncPath(), this.openFlags, this.access, this.sharing,
                            SmbConstants.ATTR_NORMAL, 0);
                }

    @Override
    public SmbFileInputStream openInputStream(final int sharing) throws SmbException {
        return openInputStream(0, O_RDONLY, sharing);
    }

    @Override
    public SmbFileInputStream openInputStream(final int flags, final int access, final int sharing) throws SmbException {
        return new SmbFileInputStream(this, flags, access, sharing, false);
    }

    @Override

class="external-link" target="_blank">using the 'X-' prefix</a>.

But if you have custom headers that you want a client in a browser to be able to see, you need to add them to your CORS configurations (read more in [CORS (Cross-Origin Resource Sharing)](../tutorial/cors.md){.internal-link target=_blank}), using the parameter `expose_headers` documented in <a href="https://www.starlette.io/middleware/#corsmiddleware" class="external-link" target="_blank">Starlette's CORS docs</a>....

     * this file is open. This constant may be logically OR'd with other share
     * access flags.
     */
    int FILE_SHARE_DELETE = 0x04;
    /**
     * Default sharing mode for files
     */
    int DEFAULT_SHARING = FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE;

    /**
     * Returned by {@link jcifs.SmbResource#getType()} if the resource this <code>SmbFile</code>

As code duplication increments the chances of bugs, security issues, code desynchronization issues (when you update in one place but not in the others), etc.

And these models are all sharing a lot of the data and duplicating attribute names and types.

We could do better.

        }
    }

    /**
     * Creates a default CIFSContext for multi-channel operations.
     * In a production implementation, this should be replaced with proper context sharing
     * from the main session to ensure consistent authentication and configuration.
     */
    private jcifs.CIFSContext createDefaultContext() throws CIFSException {
        try {

 *
 * This class supports [asynchronous canceling][cancel]. This is intended to have the smallest
 * blast radius possible. If an HTTP/2 stream is active, canceling will cancel that stream but not
 * the other streams sharing its connection. But if the TLS handshake is still in progress then
 * canceling may break the entire connection.
 */
class RealCall(
  val client: OkHttpClient,