text: // Copyright (c) 2011 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/proxy/proxy_resolver_winhttp.h"
  
  #include <windows.h>
  #include <winhttp.h>
  
  #include "base/metrics/histogram.h"
  #include "base/strings/string_util.h"
  #include "base/strings/utf_string_conversions.h"
  #include "net/base/net_errors.h"
  #include "net/proxy/proxy_info.h"
  #include "url/gurl.h"
  
  #pragma comment(lib, "winhttp.lib")
  
  using base::TimeDelta;
  using base::TimeTicks;
  
  namespace net {
  
  static void FreeInfo(WINHTTP_PROXY_INFO* info) {
    if (info->lpszProxy)
      GlobalFree(info->lpszProxy);
    if (info->lpszProxyBypass)
      GlobalFree(info->lpszProxyBypass);
  }
  
  ProxyResolverWinHttp::ProxyResolverWinHttp()
      : ProxyResolver(false /*expects_pac_bytes*/), session_handle_(NULL) {
  }
  
  ProxyResolverWinHttp::~ProxyResolverWinHttp() {
    CloseWinHttpSession();
  }
  
  int ProxyResolverWinHttp::GetProxyForURL(const GURL& query_url,
                                           ProxyInfo* results,
                                           const CompletionCallback& /*callback*/,
                                           RequestHandle* /*request*/,
                                           const BoundNetLog& /*net_log*/) {
    // If we don't have a WinHTTP session, then create a new one.
    if (!session_handle_ && !OpenWinHttpSession())
      return ERR_FAILED;
  
    // If we have been given an empty PAC url, then use auto-detection.
    //
    // NOTE: We just use DNS-based auto-detection here like Firefox.  We do this
    // to avoid WinHTTP's auto-detection code, which while more featureful (it
    // supports DHCP based auto-detection) also appears to have issues.
    //
    WINHTTP_AUTOPROXY_OPTIONS options = {0};
    options.fAutoLogonIfChallenged = FALSE;
    options.dwFlags = WINHTTP_AUTOPROXY_CONFIG_URL;
    std::wstring pac_url_wide = base::ASCIIToWide(pac_url_.spec());
    options.lpszAutoConfigUrl = pac_url_wide.c_str();
  
    WINHTTP_PROXY_INFO info = {0};
    DCHECK(session_handle_);
  
    // Per http://msdn.microsoft.com/en-us/library/aa383153(VS.85).aspx, it is
    // necessary to first try resolving with fAutoLogonIfChallenged set to false.
    // Otherwise, we fail over to trying it with a value of true.  This way we
    // get good performance in the case where WinHTTP uses an out-of-process
    // resolver.  This is important for Vista and Win2k3.
    BOOL ok = WinHttpGetProxyForUrl(session_handle_,
                                    base::ASCIIToWide(query_url.spec()).c_str(),
                                    &options, &info);
    if (!ok) {
      if (ERROR_WINHTTP_LOGIN_FAILURE == GetLastError()) {
        options.fAutoLogonIfChallenged = TRUE;
        ok = WinHttpGetProxyForUrl(
            session_handle_, base::ASCIIToWide(query_url.spec()).c_str(),
            &options, &info);
      }
      if (!ok) {
        DWORD error = GetLastError();
        // If we got here because of RPC timeout during out of process PAC
        // resolution, no further requests on this session are going to work.
        if (ERROR_WINHTTP_TIMEOUT == error ||
            ERROR_WINHTTP_AUTO_PROXY_SERVICE_ERROR == error) {
          CloseWinHttpSession();
        }
        return ERR_FAILED;  // TODO(darin): Bug 1189288: translate error code.
      }
    }
  
    int rv = OK;
  
    switch (info.dwAccessType) {
      case WINHTTP_ACCESS_TYPE_NO_PROXY:
        results->UseDirect();
        break;
      case WINHTTP_ACCESS_TYPE_NAMED_PROXY:
        // According to MSDN:
        //
        // The proxy server list contains one or more of the following strings
        // separated by semicolons or whitespace.
        //
        // ([<scheme>=][<scheme>"://"]<server>[":"<port>])
        //
        // Based on this description, ProxyInfo::UseNamedProxy() isn't
        // going to handle all the variations (in particular <scheme>=).
        //
        // However in practice, it seems that WinHTTP is simply returning
        // things like "foopy1:80;foopy2:80". It strips out the non-HTTP
        // proxy types, and stops the list when PAC encounters a "DIRECT".
        // So UseNamedProxy() should work OK.
        results->UseNamedProxy(base::UTF16ToASCII(info.lpszProxy));
        break;
      default:
        NOTREACHED();
        rv = ERR_FAILED;
    }
  
    FreeInfo(&info);
    return rv;
  }
  
  void ProxyResolverWinHttp::CancelRequest(RequestHandle request) {
    // This is a synchronous ProxyResolver; no possibility for async requests.
    NOTREACHED();
  }
  
  LoadState ProxyResolverWinHttp::GetLoadState(RequestHandle request) const {
    NOTREACHED();
    return LOAD_STATE_IDLE;
  }
  
  void ProxyResolverWinHttp::CancelSetPacScript() {
    NOTREACHED();
  }
  
  int ProxyResolverWinHttp::SetPacScript(
      const scoped_refptr<ProxyResolverScriptData>& script_data,
      const CompletionCallback& /*callback*/) {
    if (script_data->type() == ProxyResolverScriptData::TYPE_AUTO_DETECT) {
      pac_url_ = GURL("http://wpad/wpad.dat");
    } else {
      pac_url_ = script_data->url();
    }
    return OK;
  }
  
  bool ProxyResolverWinHttp::OpenWinHttpSession() {
    DCHECK(!session_handle_);
    session_handle_ = WinHttpOpen(NULL,
                                  WINHTTP_ACCESS_TYPE_NO_PROXY,
                                  WINHTTP_NO_PROXY_NAME,
                                  WINHTTP_NO_PROXY_BYPASS,
                                  0);
    if (!session_handle_)
      return false;
  
    // Since this session handle will never be used for WinHTTP connections,
    // these timeouts don't really mean much individually.  However, WinHTTP's
    // out of process PAC resolution will use a combined (sum of all timeouts)
    // value to wait for an RPC reply.
    BOOL rv = WinHttpSetTimeouts(session_handle_, 10000, 10000, 5000, 5000);
    DCHECK(rv);
  
    return true;
  }
  
  void ProxyResolverWinHttp::CloseWinHttpSession() {
    if (session_handle_) {
      WinHttpCloseHandle(session_handle_);
      session_handle_ = NULL;
    }
  }
  
  }  // namespace net
  