Don't log TransportGitSsh error stream to JVM stderr

[egit.git] / org.spearce.jgit / src / org / spearce / jgit / transport / TransportGitSsh.java

/*
 * Copyright (C) 2008, Robin Rosenberg <robin.rosenberg@dewire.com>
 * Copyright (C) 2008, Shawn O. Pearce <spearce@spearce.org>
 * Copyright (C) 2008, Marek Zawirski <marek.zawirski@gmail.com>
 *
 * 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.
 *
 * - Neither the name of the Git Development Community nor the
 *   names of its contributors may be used to endorse or promote
 *   products derived from this software without specific prior
 *   written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
 * CONTRIBUTORS "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 COPYRIGHT OWNER OR
 * CONTRIBUTORS 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.
 */

package org.spearce.jgit.transport;

import java.io.IOException;
import java.io.OutputStream;

import org.spearce.jgit.errors.NoRemoteRepositoryException;
import org.spearce.jgit.errors.TransportException;
import org.spearce.jgit.lib.Repository;
import org.spearce.jgit.util.QuotedString;

import com.jcraft.jsch.ChannelExec;
import com.jcraft.jsch.JSchException;

/**
 * Transport through an SSH tunnel.
 * <p>
 * The SSH transport requires the remote side to have Git installed, as the
 * transport logs into the remote system and executes a Git helper program on
 * the remote side to read (or write) the remote repository's files.
 * <p>
 * This transport does not support direct SCP style of copying files, as it
 * assumes there are Git specific smarts on the remote side to perform object
 * enumeration, save file modification and hook execution.
 */
public class TransportGitSsh extends SshTransport implements PackTransport {
        static boolean canHandle(final URIish uri) {
                if (!uri.isRemote())
                        return false;
                final String scheme = uri.getScheme();
                if ("ssh".equals(scheme))
                        return true;
                if ("ssh+git".equals(scheme))
                        return true;
                if ("git+ssh".equals(scheme))
                        return true;
                if (scheme == null && uri.getHost() != null && uri.getPath() != null)
                        return true;
                return false;
        }

        OutputStream errStream;

        TransportGitSsh(final Repository local, final URIish uri) {
                super(local, uri);
        }

        @Override
        public FetchConnection openFetch() throws TransportException {
                return new SshFetchConnection();
        }

        @Override
        public PushConnection openPush() throws TransportException {
                return new SshPushConnection();
        }

        private static void sqMinimal(final StringBuilder cmd, final String val) {
                if (val.matches("^[a-zA-Z0-9._/-]*$")) {
                        // If the string matches only generally safe characters
                        // that the shell is not going to evaluate specially we
                        // should leave the string unquoted. Not all systems
                        // actually run a shell and over-quoting confuses them
                        // when it comes to the command name.
                        //
                        cmd.append(val);
                } else {
                        sq(cmd, val);
                }
        }

        private static void sqAlways(final StringBuilder cmd, final String val) {
                sq(cmd, val);
        }

        private static void sq(final StringBuilder cmd, final String val) {
                if (val.length() > 0)
                        cmd.append(QuotedString.BOURNE.quote(val));
        }


        ChannelExec exec(final String exe) throws TransportException {
                initSession();

                try {
                        final ChannelExec channel = (ChannelExec) sock.openChannel("exec");
                        String path = uri.getPath();
                        if (uri.getScheme() != null && uri.getPath().startsWith("/~"))
                                path = (uri.getPath().substring(1));

                        final StringBuilder cmd = new StringBuilder();
                        final int gitspace = exe.indexOf("git ");
                        if (gitspace >= 0) {
                                sqMinimal(cmd, exe.substring(0, gitspace + 3));
                                cmd.append(' ');
                                sqMinimal(cmd, exe.substring(gitspace + 4));
                        } else
                                sqMinimal(cmd, exe);
                        cmd.append(' ');
                        sqAlways(cmd, path);
                        channel.setCommand(cmd.toString());
                        errStream = createErrorStream();
                        channel.setErrStream(errStream, true);
                        channel.connect();
                        return channel;
                } catch (JSchException je) {
                        throw new TransportException(uri, je.getMessage(), je);
                }
        }

        /**
         * @return the error stream for the channel, the stream is used to detect
         *         specific error reasons for exceptions.
         */
        private static OutputStream createErrorStream() {
                return new OutputStream() {
                        private StringBuilder all = new StringBuilder();

                        private StringBuilder sb = new StringBuilder();

                        public String toString() {
                                String r = all.toString();
                                while (r.endsWith("\n"))
                                        r = r.substring(0, r.length() - 1);
                                return r;
                        }

                        @Override
                        public void write(final int b) throws IOException {
                                if (b == '\r') {
                                        return;
                                }

                                sb.append((char) b);

                                if (b == '\n') {
                                        all.append(sb);
                                        sb.setLength(0);
                                }
                        }
                };
        }

        NoRemoteRepositoryException cleanNotFound(NoRemoteRepositoryException nf) {
                String why = errStream.toString();
                if (why == null || why.length() == 0)
                        return nf;

                String path = uri.getPath();
                if (uri.getScheme() != null && uri.getPath().startsWith("/~"))
                        path = uri.getPath().substring(1);

                final StringBuilder pfx = new StringBuilder();
                pfx.append("fatal: ");
                sqAlways(pfx, path);
                pfx.append(": ");
                if (why.startsWith(pfx.toString()))
                        why = why.substring(pfx.length());

                return new NoRemoteRepositoryException(uri, why);
        }

        class SshFetchConnection extends BasePackFetchConnection {
                private ChannelExec channel;

                SshFetchConnection() throws TransportException {
                        super(TransportGitSsh.this);
                        try {
                                channel = exec(getOptionUploadPack());

                                if (channel.isConnected())
                                        init(channel.getInputStream(), channel.getOutputStream());
                                else
                                        throw new TransportException(uri, errStream.toString());

                        } catch (TransportException err) {
                                close();
                                throw err;
                        } catch (IOException err) {
                                close();
                                throw new TransportException(uri,
                                                "remote hung up unexpectedly", err);
                        }

                        try {
                                readAdvertisedRefs();
                        } catch (NoRemoteRepositoryException notFound) {
                                throw cleanNotFound(notFound);
                        }
                }

                @Override
                public void close() {
                        super.close();

                        if (channel != null) {
                                try {
                                        if (channel.isConnected())
                                                channel.disconnect();
                                } finally {
                                        channel = null;
                                }
                        }
                }
        }

        class SshPushConnection extends BasePackPushConnection {
                private ChannelExec channel;

                SshPushConnection() throws TransportException {
                        super(TransportGitSsh.this);
                        try {
                                channel = exec(getOptionReceivePack());

                                if (channel.isConnected())
                                        init(channel.getInputStream(), channel.getOutputStream());
                                else
                                        throw new TransportException(uri, errStream.toString());

                        } catch (TransportException err) {
                                close();
                                throw err;
                        } catch (IOException err) {
                                close();
                                throw new TransportException(uri,
                                                "remote hung up unexpectedly", err);
                        }

                        try {
                                readAdvertisedRefs();
                        } catch (NoRemoteRepositoryException notFound) {
                                throw cleanNotFound(notFound);
                        }
                }

                @Override
                public void close() {
                        super.close();

                        if (channel != null) {
                                try {
                                        if (channel.isConnected())
                                                channel.disconnect();
                                } finally {
                                        channel = null;
                                }
                        }
                }
        }
}