// 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.collect.Lists;
import com.google.common.util.concurrent.Atomics;
import com.google.gerrit.extensions.annotations.RequiresCapability;
import com.google.gerrit.server.CurrentUser;
import com.google.gerrit.server.account.CapabilityControl;
import com.google.inject.Provider;
import org.apache.sshd.server.Command;
import org.apache.sshd.server.Environment;
import java.io.IOException;
import java.util.LinkedList;
import java.util.Map;
import java.util.concurrent.atomic.AtomicReference;
/** Command that executes some other command. */
public class AliasCommand extends BaseCommand {
private final DispatchCommandProvider root;
private final Provider<CurrentUser> currentUser;
private final CommandName command;
private final AtomicReference<Command> atomicCmd;
AliasCommand(@CommandName(Commands.ROOT) DispatchCommandProvider root,
Provider<CurrentUser> currentUser, CommandName command) {
this.root = root;
this.currentUser = currentUser;
this.command = command;
this.atomicCmd = Atomics.newReference();
}
@Override
public void start(Environment env) throws IOException {
try {
begin(env);
} catch (UnloggedFailure e) {
String msg = e.getMessage();
if (!msg.endsWith("\n")) {
msg += "\n";
}
err.write(msg.getBytes(ENC));
err.flush();
onExit(e.exitCode);
}
}
private void begin(Environment env) throws UnloggedFailure, IOException {
Map<String, Provider<Command>> map = root.getMap();
for (String name : chain(command)) {
Provider<? extends Command> p = map.get(name);
if (p == null) {
throw new UnloggedFailure(1, getName() + ": not found");
}
Command cmd = p.get();
if (!(cmd instanceof DispatchCommand)) {
throw new UnloggedFailure(1, getName() + ": not found");
}
map = ((DispatchCommand) cmd).getMap();
}
Provider<? extends Command> p = map.get(command.value());
if (p == null) {
throw new UnloggedFailure(1, getName() + ": not found");
}
Command cmd = p.get();
checkRequiresCapability(cmd);
if (cmd instanceof BaseCommand) {
BaseCommand bc = (BaseCommand)cmd;
bc.setName(getName());
bc.setArguments(getArguments());
}
provideStateTo(cmd);
atomicCmd.set(cmd);
cmd.start(env);
}
@Override
public void destroy() {
Command cmd = atomicCmd.getAndSet(null);
if (cmd != null) {
cmd.destroy();
}
}
private void checkRequiresCapability(Command cmd) throws UnloggedFailure {
RequiresCapability rc = cmd.getClass().getAnnotation(RequiresCapability.class);
if (rc != null) {
CurrentUser user = currentUser.get();
CapabilityControl ctl = user.getCapabilities();
if (!ctl.canPerform(rc.value()) && !ctl.canAdministrateServer()) {
String msg = String.format(
"fatal: %s does not have \"%s\" capability.",
user.getUserName(), rc.value());
throw new UnloggedFailure(BaseCommand.STATUS_NOT_ADMIN, msg);
}
}
}
private static LinkedList<String> chain(CommandName command) {
LinkedList<String> chain = Lists.newLinkedList();
while (command != null) {
chain.addFirst(command.value());
command = Commands.parentOf(command);
}
chain.removeLast();
return chain;
}
}