// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "net/http/proxy_client_socket.h"

#include "base/metrics/histogram.h"
#include "base/strings/stringprintf.h"
#include "net/base/host_port_pair.h"
#include "net/base/net_errors.h"
#include "net/base/net_util.h"
#include "net/http/http_auth_controller.h"
#include "net/http/http_request_info.h"
#include "net/http/http_response_headers.h"
#include "net/http/http_response_info.h"
#include "url/gurl.h"

namespace net {

// static
void ProxyClientSocket::BuildTunnelRequest(
    const HttpRequestInfo& request_info,
    const HttpRequestHeaders& auth_headers,
    const HostPortPair& endpoint,
    std::string* request_line,
    HttpRequestHeaders* request_headers) {
  // RFC 2616 Section 9 says the Host request-header field MUST accompany all
  // HTTP/1.1 requests.  Add "Proxy-Connection: keep-alive" for compat with
  // HTTP/1.0 proxies such as Squid (required for NTLM authentication).
  *request_line = base::StringPrintf(
      "CONNECT %s HTTP/1.1\r\n", endpoint.ToString().c_str());
  request_headers->SetHeader(HttpRequestHeaders::kHost,
                             GetHostAndOptionalPort(request_info.url));
  request_headers->SetHeader(HttpRequestHeaders::kProxyConnection,
                             "keep-alive");

  std::string user_agent;
  if (request_info.extra_headers.GetHeader(HttpRequestHeaders::kUserAgent,
                                            &user_agent))
    request_headers->SetHeader(HttpRequestHeaders::kUserAgent, user_agent);

  request_headers->MergeFrom(auth_headers);
}

// static
int ProxyClientSocket::HandleProxyAuthChallenge(HttpAuthController* auth,
                                                HttpResponseInfo* response,
                                                const BoundNetLog& net_log) {
  DCHECK(response->headers.get());
  int rv = auth->HandleAuthChallenge(response->headers, false, true, net_log);
  response->auth_challenge = auth->auth_info();
  if (rv == OK)
    return ERR_PROXY_AUTH_REQUESTED;
  return rv;
}

// static
void ProxyClientSocket::LogBlockedTunnelResponse(int http_status_code,
                                                 const GURL& url,
                                                 bool is_https_proxy) {
  if (is_https_proxy) {
    UMA_HISTOGRAM_CUSTOM_ENUMERATION(
        "Net.BlockedTunnelResponse.HttpsProxy",
        HttpUtil::MapStatusCodeForHistogram(http_status_code),
        HttpUtil::GetStatusCodesForHistogram());
  } else {
    UMA_HISTOGRAM_CUSTOM_ENUMERATION(
        "Net.BlockedTunnelResponse.HttpProxy",
        HttpUtil::MapStatusCodeForHistogram(http_status_code),
        HttpUtil::GetStatusCodesForHistogram());
  }
}

// static
bool ProxyClientSocket::SanitizeProxyRedirect(HttpResponseInfo* response,
                                              const GURL& url) {
  DCHECK(response && response->headers.get());

  std::string location;
  if (!response->headers->IsRedirect(&location))
    return false;

  // Return minimal headers; set "Content-length: 0" to ignore response body.
  std::string fake_response_headers =
      base::StringPrintf("HTTP/1.0 302 Found\n"
                         "Location: %s\n"
                         "Content-length: 0\n"
                         "Connection: close\n"
                         "\n",
                         location.c_str());
  std::string raw_headers =
      HttpUtil::AssembleRawHeaders(fake_response_headers.data(),
                                   fake_response_headers.length());
  response->headers = new HttpResponseHeaders(raw_headers);

  return true;
}

}  // namespace net