com.hierynomus.smbj.paths.SymlinkPathResolver Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of smbj Show documentation
SMB2 protocol library for communication with Windows servers
There is a newer version: 0.13.0
/*
 * Copyright (C)2016 - SMBJ Contributors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.hierynomus.smbj.paths;

import com.hierynomus.mserref.NtStatus;
import com.hierynomus.mssmb2.SMB2Error;
import com.hierynomus.mssmb2.SMB2Functions;
import com.hierynomus.mssmb2.SMB2Packet;
import com.hierynomus.protocol.commons.Charsets;
import com.hierynomus.smbj.common.SmbPath;
import com.hierynomus.smbj.session.Session;
import com.hierynomus.smbj.share.StatusHandler;

import java.util.List;

import static com.hierynomus.utils.Strings.join;
import static com.hierynomus.utils.Strings.split;

public class SymlinkPathResolver implements PathResolver {
    private PathResolver wrapped;
    private StatusHandler statusHandler;

    public SymlinkPathResolver(final PathResolver wrapped) {
        this.wrapped = wrapped;
        this.statusHandler = new StatusHandler() {
            @Override
            public boolean isSuccess(long statusCode) {
                return statusCode == NtStatus.STATUS_STOPPED_ON_SYMLINK.getValue() || wrapped.statusHandler().isSuccess(statusCode);
            }
        };
    }

    @Override
    public SmbPath resolve(Session session, SMB2Packet responsePacket, SmbPath smbPath) throws PathResolveException {
        if (responsePacket.getHeader().getStatusCode() == NtStatus.STATUS_STOPPED_ON_SYMLINK.getValue()) {
            SMB2Error.SymbolicLinkError symlinkData = getSymlinkErrorData(responsePacket.getError());
            if (symlinkData == null) {
                throw new PathResolveException(responsePacket.getHeader().getStatusCode(), "Create failed for " + smbPath + ": missing symlink data");
            }
            String target = resolveSymlinkTarget(smbPath.getPath(), symlinkData);
            return new SmbPath(smbPath.getHostname(), smbPath.getShareName(), target);
        }

        return wrapped.resolve(session, responsePacket, smbPath);
    }

    @Override
    public StatusHandler statusHandler() {
        return statusHandler;
    }

    private static SMB2Error.SymbolicLinkError getSymlinkErrorData(SMB2Error error) {
        if (error != null) {
            List errorData = error.getErrorData();
            for (SMB2Error.SMB2ErrorData errorDatum : errorData) {
                if (errorDatum instanceof SMB2Error.SymbolicLinkError) {
                    return ((SMB2Error.SymbolicLinkError) errorDatum);
                }
            }
        }
        return null;
    }

    private String resolveSymlinkTarget(String originalFileName, SMB2Error.SymbolicLinkError symlinkData) {
        int unparsedPathLength = symlinkData.getUnparsedPathLength();
        String unparsedPath = getSymlinkUnparsedPath(originalFileName, unparsedPathLength);
        String substituteName = symlinkData.getSubstituteName();

        String target;
        if (symlinkData.isAbsolute()) {
            target = substituteName + unparsedPath;
        } else {
            String parsedPath = getSymlinkParsedPath(originalFileName, unparsedPathLength);
            StringBuilder b = new StringBuilder();
            int startIndex = parsedPath.lastIndexOf("\\");
            if (startIndex != -1) {
                b.append(parsedPath, 0, startIndex);
                b.append('\\');
            }
            b.append(substituteName);
            b.append(unparsedPath);
            target = b.toString();
        }

        return normalizePath(target);
    }

    private String getSymlinkParsedPath(String fileName, int unparsedPathLength) {
        byte[] fileNameBytes = SMB2Functions.unicode(fileName);
        return new String(fileNameBytes, 0, fileNameBytes.length - unparsedPathLength, Charsets.UTF_16LE);
    }

    private String getSymlinkUnparsedPath(String fileName, int unparsedPathLength) {
        byte[] fileNameBytes = SMB2Functions.unicode(fileName);
        return new String(fileNameBytes, fileNameBytes.length - unparsedPathLength, unparsedPathLength, Charsets.UTF_16LE);
    }

    private String normalizePath(String path) {
        List parts = split(path, '\\');

        for (int i = 0; i < parts.size(); ) {
            String s = parts.get(i);
            if (".".equals(s)) {
                parts.remove(i);
            } else if ("..".equals(s)) {
                if (i > 0) {
                    parts.remove(i--);
                }
                parts.remove(i);
            } else {
                i++;
            }
        }

        return join(parts, '\\');
    }
}