package net.yacy.http.servlets;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.StringWriter;
import java.net.MalformedURLException;
import java.net.URLDecoder;
import java.nio.charset.StandardCharsets;
import java.util.HashMap;
import java.util.StringTokenizer;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import javax.servlet.Servlet;
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.HttpServletResponse;
import net.yacy.cora.document.encoding.UTF8;
import net.yacy.cora.document.id.DigestURL;
import net.yacy.cora.document.id.MultiProtocolURL;
import net.yacy.cora.protocol.ClientIdentification;
import net.yacy.cora.protocol.Domains;
import net.yacy.cora.protocol.HeaderFramework;
import net.yacy.cora.protocol.RequestHeader;
import net.yacy.cora.protocol.ResponseHeader;
import net.yacy.cora.util.ConcurrentLog;
import net.yacy.http.ProxyHandler;
import net.yacy.kelondro.util.FileUtils;
import net.yacy.search.Switchboard;
import net.yacy.server.http.ChunkedInputStream;
import net.yacy.server.http.HTTPDProxyHandler;
import org.eclipse.jetty.continuation.Continuation;
import org.eclipse.jetty.continuation.ContinuationSupport;
/**
* Servlet to implement proxy via url parameter "/proxy.html?url=xyz_urltoproxy"
* this implementation uses the existing proxy functions from YaCy HTTPDProxyHandler
*
* functionality
* - get parameters
* - convert headers to YaCy style headers and parameters
* - call existing HTTPDProxy
* - revert response headers back from YaCy style to servlet specification
* - handle rewrite of link (to point to proxy)
* - send to client
*
* later improvemnts should/could use implementation to avoid back and forth converting
* between YaCy and Servlet header/parameter style and use proxy implementation within
* servlet specification or a existing reverse-proxy library.
*
* @deprecated since 1.81 use {@link UrlProxyServlet} instead.
*/
@Deprecated //use UrlProxyServlet instead
public class YaCyProxyServlet extends HttpServlet implements Servlet {
private static final long serialVersionUID = 4900000000000001120L;
@Override
public void service (ServletRequest req, ServletResponse res) throws ServletException, IOException {
final HttpServletRequest request = (HttpServletRequest) req;
final HttpServletResponse response = (HttpServletResponse) res;
if (!Switchboard.getSwitchboard().getConfigBool("proxyURL", false)) {
response.sendError(HttpServletResponse.SC_FORBIDDEN,"proxy use not allowed. URL proxy globally switched off (see: System Administration -> Advanced Settings -> URL proxy)");
return;
}
final String remoteHost = req.getRemoteHost();
if (!Domains.isThisHostIP(remoteHost)) {
if (!proxyippatternmatch(remoteHost)) {
response.sendError(HttpServletResponse.SC_FORBIDDEN,
"proxy use not granted for IP " + remoteHost + " (see: System Administration -> Advanced Settings -> Restrict URL proxy use filter)");
return;
}
}
if ("CONNECT".equalsIgnoreCase(request.getMethod())) {
return;
}
final Continuation continuation = ContinuationSupport.getContinuation(request);
if (!continuation.isInitial()) {
response.sendError(HttpServletResponse.SC_GATEWAY_TIMEOUT); // Need better test that isInitial
return;
}
DigestURL proxyurl = null;
String strARGS = request.getQueryString();
if (strARGS == null) {
response.sendError(HttpServletResponse.SC_NOT_FOUND,"url parameter missing");
return;
}
if (strARGS.startsWith("url=")) {
final String strUrl = strARGS.substring(4); // strip "url="
try {
proxyurl = new DigestURL(strUrl);
} catch (final MalformedURLException e) {
proxyurl = new DigestURL(URLDecoder.decode(strUrl, StandardCharsets.UTF_8.name()));
}
}
if (proxyurl == null) {
response.sendError(HttpServletResponse.SC_NOT_FOUND,"url parameter missing");
return;
}
String hostwithport = proxyurl.getHost();
if (proxyurl.getPort() != -1) {
hostwithport += ":" + proxyurl.getPort();
}
RequestHeader yacyRequestHeader = ProxyHandler.convertHeaderFromJetty(request);
yacyRequestHeader.remove(RequestHeader.KEEP_ALIVE);
yacyRequestHeader.remove(HeaderFramework.CONTENT_LENGTH);
final HashMap<String, Object> prop = new HashMap<String, Object>();
prop.put(HeaderFramework.CONNECTION_PROP_HTTP_VER, HeaderFramework.HTTP_VERSION_1_1);
prop.put(HeaderFramework.CONNECTION_PROP_DIGESTURL, proxyurl);
prop.put(HeaderFramework.CONNECTION_PROP_CLIENTIP, Domains.LOCALHOST);
prop.put(HeaderFramework.CONNECTION_PROP_CLIENT_HTTPSERVLETREQUEST, request);
final ByteArrayOutputStream tmpproxyout = new ByteArrayOutputStream();
HTTPDProxyHandler.doGet(prop, yacyRequestHeader, tmpproxyout, ClientIdentification.yacyProxyAgent);
// reparse header to extract content-length and mimetype
final ResponseHeader proxyResponseHeader = new ResponseHeader(200); //
final InputStream proxyout = new ByteArrayInputStream(tmpproxyout.toByteArray());
String line = readLine(proxyout);
while (line != null && !line.equals("")) {
int p;
if ((p = line.indexOf(':')) >= 0) {
// store a property
proxyResponseHeader.add(line.substring(0, p).trim(), line.substring(p + 1).trim());
}
line = readLine(proxyout);
}
if (line == null) {
response.sendError(HttpServletResponse.SC_INTERNAL_SERVER_ERROR,"Proxy Header missing");
return;
}
final int httpStatus = Integer.parseInt((String) prop.get(HeaderFramework.CONNECTION_PROP_PROXY_RESPOND_STATUS));
String directory = "";
if (proxyurl.getPath().lastIndexOf('/') > 0) {
directory = proxyurl.getPath().substring(0, proxyurl.getPath().lastIndexOf('/'));
}
if (response.getHeader(HeaderFramework.LOCATION) != null) {
// rewrite location header
String location = response.getHeader(HeaderFramework.LOCATION);
if (location.startsWith("http")) {
location = request.getServletPath() + "?url=" + location;
} else {
location = request.getServletPath() + "?url=" + proxyurl.getProtocol() + "://" + hostwithport + "/" + location;
}
response.addHeader(HeaderFramework.LOCATION, location);
}
final String mimeType = proxyResponseHeader.getContentType();
response.setContentType(mimeType);
response.setStatus(httpStatus);
if ((mimeType != null) && (mimeType.startsWith("text"))) {
final StringWriter buffer = new StringWriter();
if (proxyResponseHeader.containsKey(HeaderFramework.TRANSFER_ENCODING) && proxyResponseHeader.get(HeaderFramework.TRANSFER_ENCODING).contains("chunked")) {
FileUtils.copy(new ChunkedInputStream(proxyout), buffer, StandardCharsets.UTF_8);
} else {
FileUtils.copy(proxyout, buffer, StandardCharsets.UTF_8);
}
final String sbuffer = buffer.toString();
final Pattern p = Pattern.compile("(href=\"|src=\")([^\"]+)|(href='|src=')([^']+)|(url\\(')([^']+)|(url\\(\")([^\"]+)|(url\\()([^\\)]+)");
final Matcher m = p.matcher(sbuffer);
final StringBuffer result = new StringBuffer(80);
final Switchboard sb = Switchboard.getSwitchboard();
final String servletstub = request.getServletPath()+"?url=";
while (m.find()) {
String init = null;
if (m.group(1) != null) { init = m.group(1); }
if (m.group(3) != null) { init = m.group(3); }
if (m.group(5) != null) { init = m.group(5); }
if (m.group(7) != null) { init = m.group(7); }
if (m.group(9) != null) { init = m.group(9); }
String url = null;
if (m.group(2) != null) { url = m.group(2); }
if (m.group(4) != null) { url = m.group(4); }
if (m.group(6) != null) { url = m.group(6); }
if (m.group(8) != null) { url = m.group(8); }
if (m.group(10) != null) { url = m.group(10); }
if (url.startsWith("data:") || url.startsWith("#") || url.startsWith("mailto:") || url.startsWith("javascript:")) {
String newurl = init + url;
newurl = newurl.replaceAll("\\$", "\\\\\\$");
m.appendReplacement(result, newurl);
} else if (url.startsWith("http")) {
// absoulte url of form href="http://domain.com/path"
if (sb.getConfig("proxyURL.rewriteURLs", "all").equals("domainlist")) {
try {
if (sb.crawlStacker.urlInAcceptedDomain(new DigestURL(url)) != null) {
continue;
}
} catch (final MalformedURLException e) {
ConcurrentLog.fine("PROXY","ProxyServlet: malformed url for url-rewirte " + url);
continue;
}
}
String newurl = init + servletstub + url;
newurl = newurl.replaceAll("\\$", "\\\\\\$");
m.appendReplacement(result, newurl);
} else if (url.startsWith("//")) {
// absoulte url but same protocol of form href="//domain.com/path"
final String complete_url = proxyurl.getProtocol() + ":" + url;
if (sb.getConfig("proxyURL.rewriteURLs", "all").equals("domainlist")) {
try {
if (sb.crawlStacker.urlInAcceptedDomain(new DigestURL(complete_url)) != null) {
continue;
}
} catch (MalformedURLException ex) {
ConcurrentLog.fine("PROXY","ProxyServlet: malformed url for url-rewirte " + complete_url);
continue;
}
}
String newurl = init + servletstub + complete_url;
newurl = newurl.replaceAll("\\$", "\\\\\\$");
m.appendReplacement(result, newurl);
} else if (url.startsWith("/")) {
// absolute path of form href="/absolute/path/to/linked/page"
String newurl = init + servletstub + "http://" + hostwithport + url;
newurl = newurl.replaceAll("\\$", "\\\\\\$");
m.appendReplacement(result, newurl);
} else {
// relative path of form href="relative/path"
try {
MultiProtocolURL target = new MultiProtocolURL("http://" + hostwithport + directory + "/" + url);
String newurl = init + servletstub + target.toString();
newurl = newurl.replaceAll("\\$", "\\\\\\$");
m.appendReplacement(result, newurl);
} catch (final MalformedURLException e) {}
}
}
m.appendTail(result);
byte[] sbb = UTF8.getBytes(result.toString());
// add some proxy-headers to response header
response.setContentType(proxyResponseHeader.getContentType());
if (proxyResponseHeader.containsKey(HeaderFramework.SERVER)) {
response.addHeader(HeaderFramework.SERVER, proxyResponseHeader.get(HeaderFramework.SERVER));
}
if (proxyResponseHeader.containsKey(HeaderFramework.DATE)) {
response.addHeader(HeaderFramework.DATE, proxyResponseHeader.get(HeaderFramework.DATE));
}
if (proxyResponseHeader.containsKey(HeaderFramework.LAST_MODIFIED)) {
response.addHeader(HeaderFramework.LAST_MODIFIED, proxyResponseHeader.get(HeaderFramework.LAST_MODIFIED));
}
if (proxyResponseHeader.containsKey(HeaderFramework.EXPIRES)) {
response.addHeader(HeaderFramework.EXPIRES, proxyResponseHeader.get(HeaderFramework.EXPIRES));
}
response.setIntHeader(HeaderFramework.CONTENT_LENGTH, sbb.length);
response.getOutputStream().write(sbb);
} else {
if ((response.getHeader(HeaderFramework.CONTENT_LENGTH) == null) && prop.containsKey(HeaderFramework.CONNECTION_PROP_PROXY_RESPOND_SIZE)) {
response.addHeader(HeaderFramework.CONTENT_LENGTH, (String) prop.get(HeaderFramework.CONNECTION_PROP_PROXY_RESPOND_SIZE));
}
FileUtils.copy(proxyout, response.getOutputStream());
}
}
private String readLine(final InputStream in) throws IOException {
final ByteArrayOutputStream buf = new ByteArrayOutputStream();
int b;
while ((b = in.read()) != '\r' && b != -1) {
buf.write(b);
}
if (b == -1) {
return null;
}
b = in.read(); // read \n
if (b == -1) {
return null;
}
return buf.toString(StandardCharsets.UTF_8.name());
}
/**
* helper for proxy IP config pattern check
*/
private boolean proxyippatternmatch(final String key) {
// the cfgippattern is a comma-separated list of patterns
// each pattern may contain one wildcard-character '*' which matches anything
final String cfgippattern = Switchboard.getSwitchboard().getConfig("proxyURL.access", "*");
if (cfgippattern.equals("*")) {
return true;
}
final StringTokenizer st = new StringTokenizer(cfgippattern, ",");
String pattern;
while (st.hasMoreTokens()) {
pattern = st.nextToken();
if (key.matches(pattern)) {
return true;
}
}
return false;
}
@Override
public String getServletInfo() {
return "YaCy Proxy Servlet";
}
}