com.google.gerrit.sshd.AliasCommand Maven / Gradle / Ivy
// Copyright (C) 2012 The Android Open Source Project
//
// 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.google.gerrit.sshd;
import com.google.common.base.Throwables;
import com.google.common.util.concurrent.Atomics;
import com.google.gerrit.extensions.api.access.GlobalOrPluginPermission;
import com.google.gerrit.extensions.restapi.AuthException;
import com.google.gerrit.server.permissions.GlobalPermission;
import com.google.gerrit.server.permissions.PermissionBackend;
import com.google.gerrit.server.permissions.PermissionBackendException;
import java.io.IOException;
import java.util.ArrayDeque;
import java.util.Map;
import java.util.Set;
import java.util.concurrent.atomic.AtomicReference;
import org.apache.sshd.server.Environment;
import org.apache.sshd.server.channel.ChannelSession;
import org.apache.sshd.server.command.Command;
/** Command that executes some other command. */
public class AliasCommand extends BaseCommand {
private final DispatchCommandProvider root;
private final PermissionBackend permissionBackend;
private final CommandName command;
private final AtomicReference atomicCmd;
AliasCommand(
@CommandName(Commands.ROOT) DispatchCommandProvider root,
PermissionBackend permissionBackend,
CommandName command) {
this.root = root;
this.permissionBackend = permissionBackend;
this.command = command;
this.atomicCmd = Atomics.newReference();
}
@Override
public void start(ChannelSession channel, Environment env) throws IOException {
try {
begin(channel, env);
} catch (Failure e) {
String msg = e.getMessage();
if (!msg.endsWith("\n")) {
msg += "\n";
}
err.write(msg.getBytes(ENC));
err.flush();
onExit(e.exitCode);
}
}
private void begin(ChannelSession channel, Environment env) throws IOException, Failure {
Map map = root.getMap();
for (String name : chain(command)) {
CommandProvider p = map.get(name);
if (p == null) {
throw die(getName() + ": not found");
}
Command cmd = p.getProvider().get();
if (!(cmd instanceof DispatchCommand)) {
throw die(getName() + ": not found");
}
map = ((DispatchCommand) cmd).getMap();
}
CommandProvider p = map.get(command.value());
if (p == null) {
throw die(getName() + ": not found");
}
Command cmd = p.getProvider().get();
checkRequiresCapability(cmd);
if (cmd instanceof BaseCommand) {
BaseCommand bc = (BaseCommand) cmd;
bc.setName(getName());
bc.setArguments(getArguments());
}
provideStateTo(cmd);
atomicCmd.set(cmd);
cmd.start(channel, env);
}
@Override
public void destroy(ChannelSession channel) {
Command cmd = atomicCmd.getAndSet(null);
if (cmd != null) {
try {
cmd.destroy(channel);
} catch (Exception e) {
Throwables.throwIfUnchecked(e);
throw new RuntimeException(e);
}
}
}
private void checkRequiresCapability(Command cmd) throws Failure {
try {
Set check = GlobalPermission.fromAnnotation(cmd.getClass());
try {
permissionBackend.currentUser().checkAny(check);
} catch (AuthException err) {
throw new UnloggedFailure(BaseCommand.STATUS_NOT_ADMIN, "fatal: " + err.getMessage());
}
} catch (PermissionBackendException err) {
throw new Failure(1, "fatal: permissions unavailable", err);
}
}
private static Iterable chain(CommandName command) {
ArrayDeque chain = new ArrayDeque<>();
while (command != null) {
chain.addFirst(command.value());
command = Commands.parentOf(command);
}
chain.removeLast();
return chain;
}
}