Add review SSH command

David Ostrovsky

2014-03-11 b799d545f37f7123aaa1ee1d0ff3b61f1f3cc8c2

 src/main/java/com/gitblit/transport/ssh/SshCommandFactory.java

@@ -16,23 +16,27 @@
package com.gitblit.transport.ssh;

import java.io.IOException;
import java.util.Scanner;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.Future;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.concurrent.atomic.AtomicReference;

import org.apache.sshd.server.Command;
import org.apache.sshd.server.CommandFactory;
import org.apache.sshd.server.Environment;
import org.eclipse.jgit.errors.RepositoryNotFoundException;
import org.eclipse.jgit.lib.Repository;
import org.eclipse.jgit.transport.PacketLineOut;
import org.eclipse.jgit.transport.ReceivePack;
import org.eclipse.jgit.transport.ServiceMayNotContinueException;
import org.eclipse.jgit.transport.UploadPack;
import org.eclipse.jgit.transport.resolver.ReceivePackFactory;
import org.eclipse.jgit.transport.resolver.ServiceNotAuthorizedException;
import org.eclipse.jgit.transport.resolver.ServiceNotEnabledException;
import org.eclipse.jgit.transport.resolver.UploadPackFactory;
import org.apache.sshd.server.ExitCallback;
import org.apache.sshd.server.SessionAware;
import org.apache.sshd.server.session.ServerSession;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.gitblit.git.RepositoryResolver;
import com.gitblit.transport.ssh.commands.DispatchCommand;
import com.gitblit.utils.WorkQueue;
import com.google.common.util.concurrent.Atomics;

/**
 *
@@ -40,125 +44,224 @@
 *
 */
public class SshCommandFactory implements CommandFactory {
   public SshCommandFactory(RepositoryResolver<SshDaemonClient> repositoryResolver, UploadPackFactory<SshDaemonClient> uploadPackFactory, ReceivePackFactory<SshDaemonClient> receivePackFactory) {
      this.repositoryResolver = repositoryResolver;
      this.uploadPackFactory = uploadPackFactory;
      this.receivePackFactory = receivePackFactory;
  private static final Logger logger = LoggerFactory
      .getLogger(SshCommandFactory.class);
  private final ScheduledExecutorService startExecutor;

  private DispatchCommand dispatcher;

   public SshCommandFactory(
       WorkQueue workQueue,
       DispatchCommand d) {
      this.dispatcher = d;
      int threads = 2;//cfg.getInt("sshd","commandStartThreads", 2);
       startExecutor = workQueue.createQueue(threads, "SshCommandStart");
   }

   private RepositoryResolver<SshDaemonClient> repositoryResolver;

   private UploadPackFactory<SshDaemonClient> uploadPackFactory;

   private ReceivePackFactory<SshDaemonClient> receivePackFactory;

   @Override
   public Command createCommand(final String commandLine) {
      Scanner commandScanner = new Scanner(commandLine);
      final String command = commandScanner.next();
      final String argument = commandScanner.nextLine();

      if ("git-upload-pack".equals(command))
         return new UploadPackCommand(argument);
      if ("git-receive-pack".equals(command))
         return new ReceivePackCommand(argument);
      return new NonCommand();
     return new Trampoline(commandLine);
   }

   public abstract class RepositoryCommand extends AbstractSshCommand {
      protected final String repositoryName;
     private class Trampoline implements Command, SessionAware {
       private final String[] argv;
       private ServerSession session;
       private InputStream in;
       private OutputStream out;
       private OutputStream err;
       private ExitCallback exit;
       private Environment env;
       private String cmdLine;
       private DispatchCommand cmd;
       private final AtomicBoolean logged;
       private final AtomicReference<Future<?>> task;

      public RepositoryCommand(String repositoryName) {
         this.repositoryName = repositoryName;
      }
       Trampoline(String line) {
         if (line.startsWith("git-")) {
            line = "git " + line;
         }
         cmdLine = line;
         argv = split(line);
         logged = new AtomicBoolean();
         task = Atomics.newReference();
       }

      @Override
      public void start(Environment env) throws IOException {
         Repository db = null;
         try {
            SshDaemonClient client = session.getAttribute(SshDaemonClient.ATTR_KEY);
            db = selectRepository(client, repositoryName);
            if (db == null) return;
            run(client, db);
            exit.onExit(0);
         } catch (ServiceNotEnabledException e) {
            // Ignored. Client cannot use this repository.
         } catch (ServiceNotAuthorizedException e) {
            // Ignored. Client cannot use this repository.
         } finally {
            if (db != null)
               db.close();
            exit.onExit(1);
         }
      }
       @Override
       public void setSession(ServerSession session) {
         this.session = session;
       }

      protected Repository selectRepository(SshDaemonClient client, String name) throws IOException {
         try {
            return openRepository(client, name);
         } catch (ServiceMayNotContinueException e) {
            // An error when opening the repo means the client is expecting a ref
            // advertisement, so use that style of error.
            PacketLineOut pktOut = new PacketLineOut(out);
            pktOut.writeString("ERR " + e.getMessage() + "\n"); //$NON-NLS-1$ //$NON-NLS-2$
            return null;
         }
      }
       @Override
      public void setInputStream(final InputStream in) {
         this.in = in;
       }

      protected Repository openRepository(SshDaemonClient client, String name)
            throws ServiceMayNotContinueException {
         // Assume any attempt to use \ was by a Windows client
         // and correct to the more typical / used in Git URIs.
         //
         name = name.replace('\\', '/');
       @Override
      public void setOutputStream(final OutputStream out) {
         this.out = out;
       }

         // ssh://git@thishost/path should always be name="/path" here
         //
         if (!name.startsWith("/")) //$NON-NLS-1$
            return null;
       @Override
      public void setErrorStream(final OutputStream err) {
         this.err = err;
       }

         try {
            return repositoryResolver.open(client, name.substring(1));
         } catch (RepositoryNotFoundException e) {
            // null signals it "wasn't found", which is all that is suitable
            // for the remote client to know.
            return null;
         } catch (ServiceNotEnabledException e) {
            // null signals it "wasn't found", which is all that is suitable
            // for the remote client to know.
            return null;
         }
      }
       @Override
      public void setExitCallback(final ExitCallback callback) {
         this.exit = callback;
       }

      protected abstract void run(SshDaemonClient client, Repository db)
         throws IOException, ServiceNotEnabledException, ServiceNotAuthorizedException;
   }
       @Override
      public void start(final Environment env) throws IOException {
         this.env = env;
         task.set(startExecutor.submit(new Runnable() {
           @Override
         public void run() {
             try {
               onStart();
             } catch (Exception e) {
               logger.warn("Cannot start command ", e);
             }
           }

   public class UploadPackCommand extends RepositoryCommand {
      public UploadPackCommand(String repositoryName) { super(repositoryName); }
           @Override
           public String toString() {
             return "start (user " + session.getUsername() + ")";
           }
         }));
       }

      @Override
      protected void run(SshDaemonClient client, Repository db)
            throws IOException, ServiceNotEnabledException, ServiceNotAuthorizedException {
         UploadPack up = uploadPackFactory.create(client, db);
         up.upload(in, out, null);
      }
   }
       private void onStart() throws IOException {
         synchronized (this) {
          SshContext ctx = new SshContext(session.getAttribute(SshSession.KEY), cmdLine);
           try {
             cmd = dispatcher;
             cmd.setArguments(argv);
             cmd.setContext(ctx);
             cmd.setInputStream(in);
             cmd.setOutputStream(out);
             cmd.setErrorStream(err);
             cmd.setExitCallback(new ExitCallback() {
               @Override
               public void onExit(int rc, String exitMessage) {
                 exit.onExit(translateExit(rc), exitMessage);
                 log(rc);
               }

   public class ReceivePackCommand extends RepositoryCommand {
      public ReceivePackCommand(String repositoryName) { super(repositoryName); }
               @Override
               public void onExit(int rc) {
                 exit.onExit(translateExit(rc));
                 log(rc);
               }
             });
             cmd.start(env);
           } finally {
            ctx = null;
           }
         }
       }

      @Override
      protected void run(SshDaemonClient client, Repository db)
            throws IOException, ServiceNotEnabledException, ServiceNotAuthorizedException {
         ReceivePack rp = receivePackFactory.create(client, db);
         rp.receive(in, out, null);
      }
   }
       private int translateExit(final int rc) {
         return rc;
//
//         switch (rc) {
//           case BaseCommand.STATUS_NOT_ADMIN:
//             return 1;
//
//           case BaseCommand.STATUS_CANCEL:
//             return 15 /* SIGKILL */;
//
//           case BaseCommand.STATUS_NOT_FOUND:
//             return 127 /* POSIX not found */;
//
//           default:
//             return rc;
//         }

   public static class NonCommand extends AbstractSshCommand {
      @Override
      public void start(Environment env) {
         exit.onExit(127);
      }
   }
       }

       private void log(final int rc) {
         if (logged.compareAndSet(false, true)) {
           //log.onExecute(cmd, rc);
           logger.info("onExecute: {} exits with: {}", cmd.getClass().getSimpleName(), rc);
         }
       }

       @Override
       public void destroy() {
         Future<?> future = task.getAndSet(null);
         if (future != null) {
           future.cancel(true);
//           destroyExecutor.execute(new Runnable() {
//             @Override
//             public void run() {
//               onDestroy();
//             }
//           });
         }
       }

       private void onDestroy() {
         synchronized (this) {
           if (cmd != null) {
             //final Context old = sshScope.set(ctx);
             try {
               cmd.destroy();
               //log(BaseCommand.STATUS_CANCEL);
             } finally {
               //ctx = null;
               cmd = null;
               //sshScope.set(old);
             }
           }
         }
       }
     }

     /** Split a command line into a string array. */
     static public String[] split(String commandLine) {
       final List<String> list = new ArrayList<String>();
       boolean inquote = false;
       boolean inDblQuote = false;
       StringBuilder r = new StringBuilder();
       for (int ip = 0; ip < commandLine.length();) {
         final char b = commandLine.charAt(ip++);
         switch (b) {
           case '\t':
           case ' ':
             if (inquote || inDblQuote)
               r.append(b);
             else if (r.length() > 0) {
               list.add(r.toString());
               r = new StringBuilder();
             }
             continue;
           case '\"':
             if (inquote)
               r.append(b);
             else
               inDblQuote = !inDblQuote;
             continue;
           case '\'':
             if (inDblQuote)
               r.append(b);
             else
               inquote = !inquote;
             continue;
           case '\\':
             if (inquote || ip == commandLine.length())
               r.append(b); // literal within a quote
             else
               r.append(commandLine.charAt(ip++));
             continue;
           default:
             r.append(b);
             continue;
         }
       }
       if (r.length() > 0) {
         list.add(r.toString());
       }
       return list.toArray(new String[list.size()]);
     }
}