// 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.httpd.plugins;
import com.google.common.base.Strings;
import com.google.common.cache.Cache;
import com.google.common.collect.Lists;
import com.google.common.collect.Maps;
import com.google.gerrit.extensions.registration.RegistrationHandle;
import com.google.gerrit.server.MimeUtilFileTypeRegistry;
import com.google.gerrit.server.config.CanonicalWebUrl;
import com.google.gerrit.server.config.GerritServerConfig;
import com.google.gerrit.server.documentation.MarkdownFormatter;
import com.google.gerrit.server.plugins.Plugin;
import com.google.gerrit.server.plugins.ReloadPluginListener;
import com.google.gerrit.server.plugins.StartPluginListener;
import com.google.gerrit.server.ssh.SshInfo;
import com.google.inject.Inject;
import com.google.inject.Provider;
import com.google.inject.Singleton;
import com.google.inject.name.Named;
import com.google.inject.servlet.GuiceFilter;
import org.eclipse.jgit.lib.Config;
import org.eclipse.jgit.util.IO;
import org.eclipse.jgit.util.RawParseUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.UnsupportedEncodingException;
import java.nio.charset.Charset;
import java.util.Collections;
import java.util.Comparator;
import java.util.Enumeration;
import java.util.List;
import java.util.Map;
import java.util.concurrent.ConcurrentMap;
import java.util.jar.Attributes;
import java.util.jar.JarEntry;
import java.util.jar.JarFile;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import javax.servlet.FilterChain;
import javax.servlet.ServletConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;
import javax.servlet.http.HttpServletResponse;
@Singleton
class HttpPluginServlet extends HttpServlet
implements StartPluginListener, ReloadPluginListener {
private static final int SMALL_RESOURCE = 128 * 1024;
private static final long serialVersionUID = 1L;
private static final Logger log
= LoggerFactory.getLogger(HttpPluginServlet.class);
private final MimeUtilFileTypeRegistry mimeUtil;
private final Provider<String> webUrl;
private final Cache<ResourceKey, Resource> resourceCache;
private final String sshHost;
private final int sshPort;
private List<Plugin> pending = Lists.newArrayList();
private String base;
private final ConcurrentMap<String, PluginHolder> plugins
= Maps.newConcurrentMap();
@Inject
HttpPluginServlet(MimeUtilFileTypeRegistry mimeUtil,
@CanonicalWebUrl Provider<String> webUrl,
@Named(HttpPluginModule.PLUGIN_RESOURCES) Cache<ResourceKey, Resource> cache,
@GerritServerConfig Config cfg,
SshInfo sshInfo) {
this.mimeUtil = mimeUtil;
this.webUrl = webUrl;
this.resourceCache = cache;
String sshHost = "review.example.com";
int sshPort = 29418;
if (!sshInfo.getHostKeys().isEmpty()) {
String host = sshInfo.getHostKeys().get(0).getHost();
int c = host.lastIndexOf(':');
if (0 <= c) {
sshHost = host.substring(0, c);
sshPort = Integer.parseInt(host.substring(c+1));
} else {
sshHost = host;
sshPort = 22;
}
}
this.sshHost = sshHost;
this.sshPort = sshPort;
}
@Override
public synchronized void init(ServletConfig config) throws ServletException {
super.init(config);
String path = config.getServletContext().getContextPath();
base = Strings.nullToEmpty(path) + "/plugins/";
for (Plugin plugin : pending) {
install(plugin);
}
pending = null;
}
@Override
public synchronized void onStartPlugin(Plugin plugin) {
if (pending != null) {
pending.add(plugin);
} else {
install(plugin);
}
}
@Override
public void onReloadPlugin(Plugin oldPlugin, Plugin newPlugin) {
install(newPlugin);
}
private void install(Plugin plugin) {
GuiceFilter filter = load(plugin);
final String name = plugin.getName();
final PluginHolder holder = new PluginHolder(plugin, filter);
plugin.add(new RegistrationHandle() {
@Override
public void remove() {
plugins.remove(name, holder);
}
});
plugins.put(name, holder);
}
private GuiceFilter load(Plugin plugin) {
if (plugin.getHttpInjector() != null) {
final String name = plugin.getName();
final GuiceFilter filter;
try {
filter = plugin.getHttpInjector().getInstance(GuiceFilter.class);
} catch (RuntimeException e) {
log.warn(String.format("Plugin %s cannot load GuiceFilter", name), e);
return null;
}
try {
WrappedContext ctx = new WrappedContext(plugin, base + name);
filter.init(new WrappedFilterConfig(ctx));
} catch (ServletException e) {
log.warn(String.format("Plugin %s failed to initialize HTTP", name), e);
return null;
}
plugin.add(new RegistrationHandle() {
@Override
public void remove() {
filter.destroy();
}
});
return filter;
}
return null;
}
@Override
public void service(HttpServletRequest req, HttpServletResponse res)
throws IOException, ServletException {
String name = extractName(req);
final PluginHolder holder = plugins.get(name);
if (holder == null) {
noCache(res);
res.sendError(HttpServletResponse.SC_NOT_FOUND);
return;
}
WrappedRequest wr = new WrappedRequest(req, base + name);
FilterChain chain = new FilterChain() {
@Override
public void doFilter(ServletRequest req, ServletResponse res)
throws IOException {
onDefault(holder, (HttpServletRequest) req, (HttpServletResponse) res);
}
};
if (holder.filter != null) {
holder.filter.doFilter(wr, res, chain);
} else {
chain.doFilter(wr, res);
}
}
private void onDefault(PluginHolder holder,
HttpServletRequest req,
HttpServletResponse res) throws IOException {
if (!"GET".equals(req.getMethod()) && !"HEAD".equals(req.getMethod())) {
noCache(res);
res.sendError(HttpServletResponse.SC_METHOD_NOT_ALLOWED);
return;
}
String uri = req.getRequestURI();
String ctx = req.getContextPath();
if (uri.length() <= ctx.length()) {
Resource.NOT_FOUND.send(req, res);
return;
}
String file = uri.substring(ctx.length() + 1);
ResourceKey key = new ResourceKey(holder.plugin, file);
Resource rsc = resourceCache.getIfPresent(key);
if (rsc != null) {
rsc.send(req, res);
return;
}
if ("".equals(file)) {
res.sendRedirect(uri + "Documentation/index.html");
} else if (file.startsWith("static/")) {
JarFile jar = holder.plugin.getJarFile();
JarEntry entry = jar.getJarEntry(file);
if (exists(entry)) {
sendResource(jar, entry, key, res);
} else {
resourceCache.put(key, Resource.NOT_FOUND);
Resource.NOT_FOUND.send(req, res);
}
} else if (file.equals("Documentation")) {
res.sendRedirect(uri + "/index.html");
} else if (file.startsWith("Documentation/") && file.endsWith("/")) {
res.sendRedirect(uri + "index.html");
} else if (file.startsWith("Documentation/")) {
JarFile jar = holder.plugin.getJarFile();
JarEntry entry = jar.getJarEntry(file);
if (!exists(entry)) {
entry = findSource(jar, file);
}
if (!exists(entry) && file.endsWith("/index.html")) {
String pfx = file.substring(0, file.length() - "index.html".length());
sendAutoIndex(jar, pfx, holder.plugin.getName(), key, res);
} else if (exists(entry) && entry.getName().endsWith(".md")) {
sendMarkdownAsHtml(jar, entry, holder.plugin.getName(), key, res);
} else if (exists(entry)) {
sendResource(jar, entry, key, res);
} else {
resourceCache.put(key, Resource.NOT_FOUND);
Resource.NOT_FOUND.send(req, res);
}
} else {
resourceCache.put(key, Resource.NOT_FOUND);
Resource.NOT_FOUND.send(req, res);
}
}
private void sendAutoIndex(JarFile jar,
String prefix, String pluginName,
ResourceKey cacheKey, HttpServletResponse res) throws IOException {
List<JarEntry> cmds = Lists.newArrayList();
List<JarEntry> docs = Lists.newArrayList();
Enumeration<JarEntry> entries = jar.entries();
while (entries.hasMoreElements()) {
JarEntry entry = entries.nextElement();
String name = entry.getName();
long size = entry.getSize();
if (name.startsWith(prefix)
&& (name.endsWith(".md")
|| name.endsWith(".html"))
&& 0 < size && size <= SMALL_RESOURCE) {
if (name.substring(prefix.length()).startsWith("cmd-")) {
cmds.add(entry);
} else {
docs.add(entry);
}
}
}
Collections.sort(cmds, new Comparator<JarEntry>() {
@Override
public int compare(JarEntry a, JarEntry b) {
return a.getName().compareTo(b.getName());
}
});
Collections.sort(docs, new Comparator<JarEntry>() {
@Override
public int compare(JarEntry a, JarEntry b) {
return a.getName().compareTo(b.getName());
}
});
StringBuilder md = new StringBuilder();
md.append(String.format("# Plugin %s #\n", pluginName));
md.append("\n");
appendPluginInfoTable(md, jar.getManifest().getMainAttributes());
if (!docs.isEmpty()) {
md.append("## Documentation ##\n");
for(JarEntry entry : docs) {
String rsrc = entry.getName().substring(prefix.length());
String title;
if (rsrc.endsWith(".html")) {
title = rsrc.substring(0, rsrc.length() - 5).replace('-', ' ');
} else if (rsrc.endsWith(".md")) {
title = extractTitleFromMarkdown(jar, entry);
if (Strings.isNullOrEmpty(title)) {
title = rsrc.substring(0, rsrc.length() - 3).replace('-', ' ');
}
rsrc = rsrc.substring(0, rsrc.length() - 3) + ".html";
} else {
title = rsrc.replace('-', ' ');
}
md.append(String.format("* [%s](%s)\n", title, rsrc));
}
md.append("\n");
}
if (!cmds.isEmpty()) {
md.append("## Commands ##\n");
for(JarEntry entry : cmds) {
String rsrc = entry.getName().substring(prefix.length());
String title;
if (rsrc.endsWith(".html")) {
title = rsrc.substring(4, rsrc.length() - 5).replace('-', ' ');
} else if (rsrc.endsWith(".md")) {
title = extractTitleFromMarkdown(jar, entry);
if (Strings.isNullOrEmpty(title)) {
title = rsrc.substring(4, rsrc.length() - 3).replace('-', ' ');
}
rsrc = rsrc.substring(0, rsrc.length() - 3) + ".html";
} else {
title = rsrc.substring(4).replace('-', ' ');
}
md.append(String.format("* [%s](%s)\n", title, rsrc));
}
md.append("\n");
}
sendMarkdownAsHtml(md.toString(), pluginName, cacheKey, res);
}
private void sendMarkdownAsHtml(String md, String pluginName,
ResourceKey cacheKey, HttpServletResponse res)
throws UnsupportedEncodingException, IOException {
Map<String, String> macros = Maps.newHashMap();
macros.put("PLUGIN", pluginName);
macros.put("SSH_HOST", sshHost);
macros.put("SSH_PORT", "" + sshPort);
String url = webUrl.get();
if (Strings.isNullOrEmpty(url)) {
url = "http://review.example.com/";
}
macros.put("URL", url);
Matcher m = Pattern.compile("(\\\\)?@([A-Z_]+)@").matcher(md);
StringBuffer sb = new StringBuffer();
while (m.find()) {
String key = m.group(2);
String val = macros.get(key);
if (m.group(1) != null) {
m.appendReplacement(sb, "@" + key + "@");
} else if (val != null) {
m.appendReplacement(sb, val);
} else {
m.appendReplacement(sb, "@" + key + "@");
}
}
m.appendTail(sb);
byte[] html = new MarkdownFormatter()
.markdownToDocHtml(sb.toString(), "UTF-8");
resourceCache.put(cacheKey, new SmallResource(html)
.setContentType("text/html")
.setCharacterEncoding("UTF-8"));
res.setContentType("text/html");
res.setCharacterEncoding("UTF-8");
res.setContentLength(html.length);
res.getOutputStream().write(html);
}
private static void appendPluginInfoTable(StringBuilder html, Attributes main) {
if (main != null) {
String t = main.getValue(Attributes.Name.IMPLEMENTATION_TITLE);
String n = main.getValue(Attributes.Name.IMPLEMENTATION_VENDOR);
String v = main.getValue(Attributes.Name.IMPLEMENTATION_VERSION);
String u = main.getValue(Attributes.Name.IMPLEMENTATION_URL);
String a = main.getValue("Gerrit-ApiVersion");
html.append("<table class=\"plugin_info\">");
if (!Strings.isNullOrEmpty(t)) {
html.append("<tr><th>Name</th><td>")
.append(t)
.append("</td></tr>\n");
}
if (!Strings.isNullOrEmpty(n)) {
html.append("<tr><th>Vendor</th><td>")
.append(n)
.append("</td></tr>\n");
}
if (!Strings.isNullOrEmpty(v)) {
html.append("<tr><th>Version</th><td>")
.append(v)
.append("</td></tr>\n");
}
if (!Strings.isNullOrEmpty(u)) {
html.append("<tr><th>URL</th><td>")
.append(String.format("<a href=\"%s\">%s</a>", u, u))
.append("</td></tr>\n");
}
if (!Strings.isNullOrEmpty(a)) {
html.append("<tr><th>API Version</th><td>")
.append(a)
.append("</td></tr>\n");
}
html.append("</table>\n");
}
}
private static String extractTitleFromMarkdown(JarFile jar, JarEntry entry)
throws IOException {
String charEnc = null;
Attributes atts = entry.getAttributes();
if (atts != null) {
charEnc = Strings.emptyToNull(atts.getValue("Character-Encoding"));
}
if (charEnc == null) {
charEnc = "UTF-8";
}
return new MarkdownFormatter().extractTitleFromMarkdown(
readWholeEntry(jar, entry),
charEnc);
}
private static JarEntry findSource(JarFile jar, String file) {
if (file.endsWith(".html")) {
int d = file.lastIndexOf('.');
return jar.getJarEntry(file.substring(0, d) + ".md");
}
return null;
}
private static boolean exists(JarEntry entry) {
return entry != null && entry.getSize() > 0;
}
private void sendMarkdownAsHtml(JarFile jar, JarEntry entry,
String pluginName, ResourceKey key, HttpServletResponse res)
throws IOException {
byte[] rawmd = readWholeEntry(jar, entry);
String encoding = null;
Attributes atts = entry.getAttributes();
if (atts != null) {
encoding = Strings.emptyToNull(atts.getValue("Character-Encoding"));
}
String txtmd = RawParseUtils.decode(
Charset.forName(encoding != null ? encoding : "UTF-8"),
rawmd);
long time = entry.getTime();
if (0 < time) {
res.setDateHeader("Last-Modified", time);
}
sendMarkdownAsHtml(txtmd, pluginName, key, res);
}
private void sendResource(JarFile jar, JarEntry entry,
ResourceKey key, HttpServletResponse res)
throws IOException {
byte[] data = null;
if (entry.getSize() <= SMALL_RESOURCE) {
data = readWholeEntry(jar, entry);
}
String contentType = null;
String charEnc = null;
Attributes atts = entry.getAttributes();
if (atts != null) {
contentType = Strings.emptyToNull(atts.getValue("Content-Type"));
charEnc = Strings.emptyToNull(atts.getValue("Character-Encoding"));
}
if (contentType == null) {
contentType = mimeUtil.getMimeType(entry.getName(), data).toString();
}
long time = entry.getTime();
if (0 < time) {
res.setDateHeader("Last-Modified", time);
}
res.setHeader("Content-Length", Long.toString(entry.getSize()));
res.setContentType(contentType);
if (charEnc != null) {
res.setCharacterEncoding(charEnc);
}
if (data != null) {
resourceCache.put(key, new SmallResource(data)
.setContentType(contentType)
.setCharacterEncoding(charEnc)
.setLastModified(time));
res.getOutputStream().write(data);
} else {
InputStream in = jar.getInputStream(entry);
try {
OutputStream out = res.getOutputStream();
try {
byte[] tmp = new byte[1024];
int n;
while ((n = in.read(tmp)) > 0) {
out.write(tmp, 0, n);
}
} finally {
out.close();
}
} finally {
in.close();
}
}
}
private static byte[] readWholeEntry(JarFile jar, JarEntry entry)
throws IOException {
byte[] data = new byte[(int) entry.getSize()];
InputStream in = jar.getInputStream(entry);
try {
IO.readFully(in, data, 0, data.length);
} finally {
in.close();
}
return data;
}
private static String extractName(HttpServletRequest req) {
String path = req.getPathInfo();
if (Strings.isNullOrEmpty(path) || "/".equals(path)) {
return "";
}
int s = path.indexOf('/', 1);
return 0 <= s ? path.substring(1, s) : path.substring(1);
}
static void noCache(HttpServletResponse res) {
res.setHeader("Expires", "Fri, 01 Jan 1980 00:00:00 GMT");
res.setHeader("Pragma", "no-cache");
res.setHeader("Cache-Control", "no-cache, must-revalidate");
res.setHeader("Content-Disposition", "attachment");
}
private static class PluginHolder {
final Plugin plugin;
final GuiceFilter filter;
PluginHolder(Plugin plugin, GuiceFilter filter) {
this.plugin = plugin;
this.filter = filter;
}
}
private static class WrappedRequest extends HttpServletRequestWrapper {
private final String contextPath;
WrappedRequest(HttpServletRequest req, String contextPath) {
super(req);
this.contextPath = contextPath;
}
@Override
public String getContextPath() {
return contextPath;
}
@Override
public String getServletPath() {
return ((HttpServletRequest) getRequest()).getRequestURI();
}
}
}