#include <cstring>
#include <cassert>
#include <string>
#include <atomic>
#include <memory>
#include <set>
#include <boost/asio.hpp>
#include <mutex>
#include "I2PService.h"
#include "Destination.h"
#include "HTTPProxy.h"
#include "util.h"
#include "Identity.h"
#include "Streaming.h"
#include "Destination.h"
#include "ClientContext.h"
#include "I2PEndian.h"
#include "I2PTunnel.h"
#include "Config.h"
#include "HTTP.h"
namespace i2p {
namespace proxy {
std::map<std::string, std::string> jumpservices = {
{ "inr.i2p", "http://joajgazyztfssty4w2on5oaqksz6tqoxbduy553y34mf4byv6gpq.b32.i2p/search/?q=" },
{ "stats.i2p", "http://7tbay5p4kzeekxvyvbf6v7eauazemsnnl2aoyqhg5jzpr5eke7tq.b32.i2p/cgi-bin/jump.cgi?a=" },
};
static const char *pageHead =
"<head>\r\n"
" <title>I2Pd HTTP proxy</title>\r\n"
" <style type=\"text/css\">\r\n"
" body { font: 100%/1.5em sans-serif; margin: 0; padding: 1.5em; background: #FAFAFA; color: #103456; }\r\n"
" .header { font-size: 2.5em; text-align: center; margin: 1.5em 0; color: #894C84; }\r\n"
" </style>\r\n"
"</head>\r\n"
;
bool str_rmatch(std::string & str, const char *suffix) {
auto pos = str.rfind (suffix);
if (pos == std::string::npos)
return false; /* not found */
if (str.length() == (pos + std::strlen(suffix)))
return true; /* match */
return false;
}
class HTTPReqHandler: public i2p::client::I2PServiceHandler, public std::enable_shared_from_this<HTTPReqHandler>
{
private:
bool HandleRequest();
void HandleSockRecv(const boost::system::error_code & ecode, std::size_t bytes_transfered);
void Terminate();
void AsyncSockRead();
bool ExtractAddressHelper(i2p::http::URL & url, std::string & b64);
void SanitizeHTTPRequest(i2p::http::HTTPReq & req);
void SentHTTPFailed(const boost::system::error_code & ecode);
void HandleStreamRequestComplete (std::shared_ptr<i2p::stream::Stream> stream);
/* error helpers */
void GenericProxyError(const char *title, const char *description);
void GenericProxyInfo(const char *title, const char *description);
void HostNotFound(std::string & host);
void SendProxyError(std::string & content);
uint8_t m_recv_chunk[8192];
std::string m_recv_buf; // from client
std::string m_send_buf; // to upstream
std::shared_ptr<boost::asio::ip::tcp::socket> m_sock;
public:
HTTPReqHandler(HTTPProxy * parent, std::shared_ptr<boost::asio::ip::tcp::socket> sock) :
I2PServiceHandler(parent), m_sock(sock) {}
~HTTPReqHandler() { Terminate(); }
void Handle () { AsyncSockRead(); } /* overload */
};
void HTTPReqHandler::AsyncSockRead()
{
LogPrint(eLogDebug, "HTTPProxy: async sock read");
if (!m_sock) {
LogPrint(eLogError, "HTTPProxy: no socket for read");
return;
}
m_sock->async_read_some(boost::asio::buffer(m_recv_chunk, sizeof(m_recv_chunk)),
std::bind(&HTTPReqHandler::HandleSockRecv, shared_from_this(),
std::placeholders::_1, std::placeholders::_2));
}
void HTTPReqHandler::Terminate() {
if (Kill()) return;
if (m_sock)
{
LogPrint(eLogDebug, "HTTPProxy: close sock");
m_sock->close();
m_sock = nullptr;
}
Done(shared_from_this());
}
void HTTPReqHandler::GenericProxyError(const char *title, const char *description) {
std::stringstream ss;
ss << "<h1>Proxy error: " << title << "</h1>\r\n";
ss << "<p>" << description << "</p>\r\n";
std::string content = ss.str();
SendProxyError(content);
}
void HTTPReqHandler::GenericProxyInfo(const char *title, const char *description) {
std::stringstream ss;
ss << "<h1>Proxy info: " << title << "</h1>\r\n";
ss << "<p>" << description << "</p>\r\n";
std::string content = ss.str();
SendProxyError(content);
}
void HTTPReqHandler::HostNotFound(std::string & host) {
std::stringstream ss;
ss << "<h1>Proxy error: Host not found</h1>\r\n"
<< "<p>Remote host not found in router's addressbook</p>\r\n"
<< "<p>You may try to find this host on jumpservices below:</p>\r\n"
<< "<ul>\r\n";
for (const auto& js : jumpservices) {
ss << " <li><a href=\"" << js.second << host << "\">" << js.first << "</a></li>\r\n";
}
ss << "</ul>\r\n";
std::string content = ss.str();
SendProxyError(content);
}
void HTTPReqHandler::SendProxyError(std::string & content)
{
i2p::http::HTTPRes res;
res.code = 500;
res.add_header("Content-Type", "text/html; charset=UTF-8");
res.add_header("Connection", "close");
std::stringstream ss;
ss << "<html>\r\n" << pageHead
<< "<body>" << content << "</body>\r\n"
<< "</html>\r\n";
res.body = ss.str();
std::string response = res.to_string();
boost::asio::async_write(*m_sock, boost::asio::buffer(response),
std::bind(&HTTPReqHandler::SentHTTPFailed, shared_from_this(), std::placeholders::_1));
}
bool HTTPReqHandler::ExtractAddressHelper(i2p::http::URL & url, std::string & b64)
{
const char *param = "i2paddresshelper=";
std::size_t pos = url.query.find(param);
std::size_t len = std::strlen(param);
std::map<std::string, std::string> params;
if (pos == std::string::npos)
return false; /* not found */
if (!url.parse_query(params))
return false;
std::string value = params["i2paddresshelper"];
len += value.length();
b64 = i2p::http::UrlDecode(value);
url.query.replace(pos, len, "");
return true;
}
void HTTPReqHandler::SanitizeHTTPRequest(i2p::http::HTTPReq & req)
{
/* drop common headers */
req.del_header("Referer");
req.del_header("Via");
req.del_header("Forwarded");
/* drop proxy-disclosing headers */
std::vector<std::string> toErase;
for (const auto& it : req.headers) {
if (it.first.compare(0, 12, "X-Forwarded-") == 0) {
toErase.push_back(it.first);
} else if (it.first.compare(0, 6, "Proxy-") == 0) {
toErase.push_back(it.first);
} else {
/* allow */
}
}
for (const auto& header : toErase) {
req.headers.erase(header);
}
/* replace headers */
req.add_header("Connection", "close", true); /* keep-alive conns not supported yet */
req.add_header("User-Agent", "MYOB/6.66 (AN/ON)", true); /* privacy */
}
/**
* @brief Try to parse request from @a m_recv_buf
* If parsing success, rebuild request and store to @a m_send_buf
* with remaining data tail
* @return true on processed request or false if more data needed
*/
bool HTTPReqHandler::HandleRequest()
{
i2p::http::HTTPReq req;
i2p::http::URL url;
std::string b64;
int req_len = 0;
req_len = req.parse(m_recv_buf);
if (req_len == 0)
return false; /* need more data */
if (req_len < 0) {
LogPrint(eLogError, "HTTPProxy: unable to parse request");
GenericProxyError("Invalid request", "Proxy unable to parse your request");
return true; /* parse error */
}
/* parsing success, now let's look inside request */
LogPrint(eLogDebug, "HTTPProxy: requested: ", req.uri);
url.parse(req.uri);
if (ExtractAddressHelper(url, b64)) {
i2p::client::context.GetAddressBook ().InsertAddress (url.host, b64);
LogPrint (eLogInfo, "HTTPProxy: added b64 from addresshelper for ", url.host);
std::string full_url = url.to_string();
std::stringstream ss;
ss << "Host " << url.host << " added to router's addressbook from helper. "
<< "Click <a href=\"" << full_url << "\">here</a> to proceed.";
GenericProxyInfo("Addresshelper found", ss.str().c_str());
return true; /* request processed */
}
SanitizeHTTPRequest(req);
std::string dest_host = url.host;
uint16_t dest_port = url.port;
/* always set port, even if missing in request */
if (!dest_port) {
dest_port = (url.schema == "https") ? 443 : 80;
}
/* detect dest_host, set proper 'Host' header in upstream request */
auto h = req.headers.find("Host");
if (dest_host != "") {
/* absolute url, replace 'Host' header */
std::string h = dest_host;
if (dest_port != 0 && dest_port != 80)
h += ":" + std::to_string(dest_port);
req.add_header("Host", h, true);
} else if (h != req.headers.end()) {
/* relative url and 'Host' header provided. transparent proxy mode? */
i2p::http::URL u;
std::string t = "http://" + h->second;
u.parse(t);
dest_host = u.host;
dest_port = u.port;
} else {
/* relative url and missing 'Host' header */
GenericProxyError("Invalid request", "Can't detect destination host from request");
return true;
}
/* check dest_host really exists and inside I2P network */
i2p::data::IdentHash identHash;
if (str_rmatch(dest_host, ".i2p")) {
if (!i2p::client::context.GetAddressBook ().GetIdentHash (dest_host, identHash)) {
HostNotFound(dest_host);
return true; /* request processed */
}
/* TODO: outproxy handler here */
} else {
LogPrint (eLogWarning, "HTTPProxy: outproxy failure for ", dest_host, ": not implemented yet");
std::string message = "Host" + dest_host + "not inside I2P network, but outproxy support not implemented yet";
GenericProxyError("Outproxy failure", message.c_str());
return true;
}
/* make relative url */
url.schema = "";
url.host = "";
req.uri = url.to_string();
/* drop original request from recv buffer */
m_recv_buf.erase(0, req_len);
/* build new buffer from modified request and data from original request */
m_send_buf = req.to_string();
m_send_buf.append(m_recv_buf);
/* connect to destination */
LogPrint(eLogDebug, "HTTPProxy: connecting to host ", dest_host, ":", dest_port);
GetOwner()->CreateStream (std::bind (&HTTPReqHandler::HandleStreamRequestComplete,
shared_from_this(), std::placeholders::_1), dest_host, dest_port);
return true;
}
/* will be called after some data received from client */
void HTTPReqHandler::HandleSockRecv(const boost::system::error_code & ecode, std::size_t len)
{
LogPrint(eLogDebug, "HTTPProxy: sock recv: ", len, " bytes, recv buf: ", m_recv_buf.length(), ", send buf: ", m_send_buf.length());
if(ecode)
{
LogPrint(eLogWarning, "HTTPProxy: sock recv got error: ", ecode);
Terminate();
return;
}
m_recv_buf.append(reinterpret_cast<const char *>(m_recv_chunk), len);
if (HandleRequest()) {
m_recv_buf.clear();
return;
}
AsyncSockRead();
}
void HTTPReqHandler::SentHTTPFailed(const boost::system::error_code & ecode)
{
if (ecode)
LogPrint (eLogError, "HTTPProxy: Closing socket after sending failure because: ", ecode.message ());
Terminate();
}
void HTTPReqHandler::HandleStreamRequestComplete (std::shared_ptr<i2p::stream::Stream> stream)
{
if (!stream) {
LogPrint (eLogError, "HTTPProxy: error when creating the stream, check the previous warnings for more info");
GenericProxyError("Host is down", "Can't create connection to requested host, it may be down");
return;
}
if (Kill())
return;
LogPrint (eLogDebug, "HTTPProxy: Created new I2PTunnel stream, sSID=", stream->GetSendStreamID(), ", rSID=", stream->GetRecvStreamID());
auto connection = std::make_shared<i2p::client::I2PTunnelConnection>(GetOwner(), m_sock, stream);
GetOwner()->AddHandler (connection);
connection->I2PConnect (reinterpret_cast<const uint8_t*>(m_send_buf.data()), m_send_buf.length());
Done (shared_from_this());
}
HTTPProxy::HTTPProxy(const std::string& address, int port, std::shared_ptr<i2p::client::ClientDestination> localDestination):
TCPIPAcceptor(address, port, localDestination ? localDestination : i2p::client::context.GetSharedLocalDestination ())
{
}
std::shared_ptr<i2p::client::I2PServiceHandler> HTTPProxy::CreateHandler(std::shared_ptr<boost::asio::ip::tcp::socket> socket)
{
return std::make_shared<HTTPReqHandler> (this, socket);
}
} // http
} // i2p