com.google.gerrit.sshd.DispatchCommand Maven / Gradle / Ivy
// Copyright (C) 2009 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.Strings;
import com.google.common.base.Throwables;
import com.google.common.collect.Sets;
import com.google.common.util.concurrent.Atomics;
import com.google.gerrit.extensions.registration.DynamicSet;
import com.google.gerrit.extensions.restapi.AuthException;
import com.google.gerrit.server.DynamicOptions;
import com.google.gerrit.server.args4j.SubcommandHandler;
import com.google.gerrit.server.permissions.GlobalPermission;
import com.google.gerrit.server.permissions.PermissionBackend;
import com.google.gerrit.server.permissions.PermissionBackendException;
import com.google.inject.Inject;
import com.google.inject.assistedinject.Assisted;
import java.io.IOException;
import java.io.StringWriter;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
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;
import org.kohsuke.args4j.Argument;
/** Command that dispatches to a subcommand from its command table. */
final class DispatchCommand extends BaseCommand {
interface Factory {
DispatchCommand create(Map map);
}
private final PermissionBackend permissionBackend;
private final Map commands;
private final AtomicReference atomicCmd;
private final DynamicSet commandInterceptors;
@Argument(index = 0, required = false, metaVar = "COMMAND", handler = SubcommandHandler.class)
private String commandName;
@Argument(index = 1, multiValued = true, metaVar = "ARG")
private List args = new ArrayList<>();
@Inject
DispatchCommand(
PermissionBackend permissionBackend,
DynamicSet commandInterceptors,
@Assisted Map all) {
this.permissionBackend = permissionBackend;
commands = all;
atomicCmd = Atomics.newReference();
this.commandInterceptors = commandInterceptors;
}
Map getMap() {
return commands;
}
@Override
public void start(ChannelSession channel, Environment env) throws IOException {
try (DynamicOptions pluginOptions = new DynamicOptions(injector, dynamicBeans)) {
parseCommandLine(pluginOptions);
if (Strings.isNullOrEmpty(commandName)) {
StringWriter msg = new StringWriter();
msg.write(usage());
throw die(msg.toString());
}
final CommandProvider p = commands.get(commandName);
if (p == null) {
String msg =
(getName().isEmpty() ? "Gerrit Code Review" : getName())
+ ": "
+ commandName
+ ": not found";
throw die(msg);
}
final Command cmd = p.getProvider().get();
checkRequiresCapability(cmd);
String actualCommandName = commandName;
if (cmd instanceof BaseCommand) {
final BaseCommand bc = (BaseCommand) cmd;
if (!getName().isEmpty()) {
actualCommandName = getName() + " " + commandName;
}
bc.setName(actualCommandName);
bc.setArguments(args.toArray(new String[args.size()]));
} else if (!args.isEmpty()) {
throw die(commandName + " does not take arguments");
}
for (SshExecuteCommandInterceptor commandInterceptor : commandInterceptors) {
if (!commandInterceptor.accept(actualCommandName, args)) {
throw new UnloggedFailure(
126,
String.format(
"blocked by %s, contact gerrit administrators for more details",
commandInterceptor.name()));
}
}
provideStateTo(cmd);
atomicCmd.set(cmd);
cmd.start(channel, 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 checkRequiresCapability(Command cmd) throws UnloggedFailure {
String pluginName = null;
if (cmd instanceof BaseCommand) {
pluginName = ((BaseCommand) cmd).getPluginName();
}
try {
permissionBackend
.currentUser()
.checkAny(GlobalPermission.fromAnnotation(pluginName, cmd.getClass()));
} catch (AuthException e) {
throw new UnloggedFailure(BaseCommand.STATUS_NOT_ADMIN, e.getMessage());
} catch (PermissionBackendException e) {
throw new UnloggedFailure(1, "fatal: permission check unavailable", e);
}
}
@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);
}
}
}
@Override
protected String usage() {
final StringBuilder usage = new StringBuilder();
usage.append("Available commands");
if (!getName().isEmpty()) {
usage.append(" of ");
usage.append(getName());
}
usage.append(" are:\n");
usage.append("\n");
int maxLength = -1;
for (String name : commands.keySet()) {
maxLength = Math.max(maxLength, name.length());
}
String format = "%-" + maxLength + "s %s";
for (String name : Sets.newTreeSet(commands.keySet())) {
final CommandProvider p = commands.get(name);
usage.append(" ");
usage.append(String.format(format, name, Strings.nullToEmpty(p.getDescription())));
usage.append("\n");
}
usage.append("\n");
usage.append("See '");
if (getName().indexOf(' ') < 0) {
usage.append(getName());
usage.append(' ');
}
usage.append("COMMAND --help' for more information.\n");
usage.append("\n");
return usage.toString();
}
public String getCommandName() {
return commandName;
}
}