kresolverstandardworkers.cpp

来自「konqueror3 embedded版本, KDE环境下的当家浏览器的嵌入式版」· C++ 代码 · 共 1,029 行 · 第 1/2 页

/*  -*- C++ -*-
 *  Copyright (C) 2003,2004 Thiago Macieira <[e-mail]>
 *
 *
 *  Permission is hereby granted, free of charge, to any person obtaining
 *  a copy of this software and associated documentation files (the
 *  "Software"), to deal in the Software without restriction, including
 *  without limitation the rights to use, copy, modify, merge, publish,
 *  distribute, sublicense, and/or sell copies of the Software, and to
 *  permit persons to whom the Software is furnished to do so, subject to
 *  the following conditions:
 *
 *  The above copyright notice and this permission notice shall be included 
 *  in all copies or substantial portions of the Software.
 *
 *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 *  EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 *  MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 *  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
 *  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
 *  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
 *  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */

#include <config.h>

#include <sys/types.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <netinet/in.h>
#include <netdb.h>
#include <errno.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>

#ifdef HAVE_NET_IF_H
#include <net/if.h>
#endif

#include <qthread.h>
#include <qmutex.h>
#include <qstrlist.h>
#include <qfile.h>

#include "kdebug.h"
#include "kglobal.h"
#include "kstandarddirs.h"
#include "kapplication.h"

#include "kresolver.h"
#include "ksocketaddress.h"
#include "kresolverstandardworkers_p.h"

struct hostent;
struct addrinfo;

using namespace KNetwork;
using namespace KNetwork::Internal;

static bool hasIPv6()
{
#ifndef AF_INET6
  return false;
#else
  if (getenv("KDE_NO_IPV6") != 0L)
    return false;

  int fd = ::socket(AF_INET6, SOCK_STREAM, 0);
  if (fd == -1)
    return false;

  ::close(fd);
  return true;
#endif
}

// blacklist management
static QMutex blacklistMutex;	// KDE4: change to a QReadWriteLock
QStringList KBlacklistWorker::blacklist;

void KBlacklistWorker::init()
{
  // HACK!
  // FIXME KDE4: How do I detect there is an instance, without triggering
  // its creation or an assertion fault?
  if (!KGlobal::_instance)
    return;

  static bool beenhere = false;

  if (beenhere)
    return;

  beenhere = true;
  loadBlacklist();
}

void KBlacklistWorker::loadBlacklist()
{
  QMutexLocker locker(&blacklistMutex);
  QStringList filelist = KGlobal::dirs()->findAllResources("config", "ipv6blacklist");

  QStringList::ConstIterator it = filelist.constBegin(),
    end = filelist.constEnd();
  for ( ; it != end; ++it)
    {
      // for each file, each line is a domainname to be blacklisted
      QFile f(*it);
      if (!f.open(IO_ReadOnly))
	continue;

      QTextStream stream(&f);
      stream.setEncoding(QTextStream::Latin1);
      for (QString line = stream.readLine(); !line.isNull(); 
	   line = stream.readLine())
	{
	  if (line.isEmpty())
	    continue;

	  // make sure there are no surrounding whitespaces
	  // and that it starts with .
	  line = line.stripWhiteSpace();
	  if (line[0] != '.')
	    line.prepend('.');
	  
	  blacklist.append(line.lower());
	}
    }
}

// checks the blacklist to see if the domain is listed
// it matches the domain ending part
bool KBlacklistWorker::isBlacklisted(const QString& host)
{
  KBlacklistWorker::init();

  // empty hostnames cannot be blacklisted
  if (host.isEmpty())
    return false;

  // KDE4: QLatin1String
  QString ascii = QString::fromLatin1(KResolver::domainToAscii(host));

  QMutexLocker locker(&blacklistMutex);

  // now find out if this hostname is present
  QStringList::ConstIterator it = blacklist.constBegin(),
    end = blacklist.constEnd();
  for ( ; it != end; ++it)
    if (ascii.endsWith(*it))
      return true;

  // no match:
  return false;
}

bool KBlacklistWorker::preprocess()
{
  if (isBlacklisted(nodeName()))
    {
      results.setError(KResolver::NoName);
      finished();
      return true;
    }
  return false;
}

bool KBlacklistWorker::run()
{
  results.setError(KResolver::NoName);
  finished();
  return false;			// resolution failure
}

namespace
{
  /*
   * Note on the use of the system resolver functions:
   *
   * In all cases, we prefer to use the new getaddrinfo(3) call. That means
   * it will always be used if it is found.
   *
   * If it's not found, we have the option to use gethostbyname2_r, 
   * gethostbyname_r, gethostbyname2 and gethostbyname. If gethostbyname2_r
   * is defined, we will use it.
   *
   * If it's not defined, we have to choose between the non-reentrant
   * gethostbyname2 and the reentrant but IPv4-only gethostbyname_r:
   * we will choose gethostbyname2 if AF_INET6 is defined.
   *
   * Lastly, gethostbyname will be used if nothing else is present.
   */

#ifndef HAVE_GETADDRINFO

# if defined(HAVE_GETHOSTBYNAME2_R)
#  define USE_GETHOSTBYNAME2_R
# elif defined(HAVE_GETHOSTBYNAME_R) && (!defined(AF_INET6) || !defined(HAVE_GETHOSTBYNAME2))
#  define USE_GETHOSTBYNAME_R
# elif defined(HAVE_GETHOSTBYNAME2)
#  define USE_GETHOSTBYNAME2)
# else
#  define USE_GETHOSTBYNAME
# endif

  class GetHostByNameThread: public KResolverWorkerBase
  {
  public:
    QCString m_hostname;	// might be different!
    Q_UINT16 m_port;
    int m_scopeid;
    int m_af;
    KResolverResults& results;

    GetHostByNameThread(const char * hostname, Q_UINT16 port,
			int scopeid, int af, KResolverResults* res) :
      m_hostname(hostname), m_port(port), m_scopeid(scopeid), m_af(af),
      results(*res)
    { }

    ~GetHostByNameThread()
    { }

    virtual bool preprocess()
    { return true; }

    virtual bool run();

    void processResults(hostent* he, int my_h_errno);
  };

  bool GetHostByNameThread::run()
  {

    hostent *resultptr;
    hostent my_results;
    unsigned buflen = 1024;
    int res;
    int my_h_errno;
    char *buf = 0L;

    // qDebug("ResolveThread::run(): started threaded gethostbyname for %s (af = %d)", 
    //	   m_hostname.data(), m_af);

    ResolverLocker resLock( this );
    do
      {
	res = 0;
	my_h_errno = HOST_NOT_FOUND;

	// check blacklist
	if (m_af != AF_INET && 
	    KBlacklistWorker::isBlacklisted(QString::fromLatin1(m_hostname)))
	  break;

# ifdef USE_GETHOSTBYNAME2_R
	buf = new char[buflen];
	res = gethostbyname2_r(m_hostname, m_af, &my_results, buf, buflen,
			       &resultptr, &my_h_errno);

# elif defined(USE_GETHOSTBYNAME_R)
	if (m_af == AF_INET)
	  {
	    buf = new char[buflen];
	    res = gethostbyname_r(m_hostname, &my_results, buf, buflen,
				  &resultptr, &my_h_errno);
	  }
	else
	  resultptr = 0;		// signal error

# elif defined(USE_GETHOSTBYNAME2)
	// must lock mutex
	resultptr = gethostbyname2(m_hostname, m_af);
	my_h_errno = h_errno;

# else
	if (m_af == AF_INET)
	  {
	    // must lock mutex
	    resultptr = gethostbyname(m_hostname);
	    my_h_errno = h_errno;
	  }
	else
	  resultptr = 0;
# endif

	if (resultptr != 0L)
	  my_h_errno = 0;
	// qDebug("GetHostByNameThread::run(): gethostbyname for %s (af = %d) returned: %d",
	//       m_hostname.data(), m_af, my_h_errno);

	if (res == ERANGE)
	  {
	    // Enlarge the buffer
	    buflen += 1024;
	    delete [] buf;
	    buf = new char[buflen];
	  }

	if ((res == ERANGE || my_h_errno != 0) && checkResolver())
	  {
	    // resolver needs updating, so we might as well do it now
	    resLock.openClose();
	  }
      }
    while (res == ERANGE);
    processResults(resultptr, my_h_errno);

    delete [] buf;

    finished();
    return results.error() == KResolver::NoError;
  }

  void GetHostByNameThread::processResults(hostent *he, int herrno)
  {
    if (herrno)
      {
	qDebug("KStandardWorker::processResults: got error %d", herrno);
	switch (herrno)
	  {
	  case HOST_NOT_FOUND:
	    results.setError(KResolver::NoName);
	    return;

	  case TRY_AGAIN:
	    results.setError(KResolver::TryAgain);
	    return;

	  case NO_RECOVERY:
	    results.setError(KResolver::NonRecoverable);
	    return;

	  case NO_ADDRESS:
	    results.setError(KResolver::NoName);
	    return;

	  default:
	    results.setError(KResolver::UnknownError);
	    return;
	  }
      }
    else if (he == 0L)
      {
	results.setError(KResolver::NoName);
	return;			// this was an error
      }

    // clear any errors
    setError(KResolver::NoError);
    results.setError(KResolver::NoError);

    // we process results in the reverse order
    // that is, we prepend each result to the list of results
    int proto = protocol();
    int socktype = socketType();
    if (socktype == 0)
      socktype = SOCK_STREAM;	// default

    QString canon = KResolver::domainToUnicode(QString::fromLatin1(he->h_name));
    KInetSocketAddress sa;
    sa.setPort(m_port);
    if (he->h_addrtype != AF_INET)
      sa.setScopeId(m_scopeid);	// this will also change the socket into IPv6

    for (int i = 0; he->h_addr_list[i]; i++)
      {
	sa.setHost(KIpAddress(he->h_addr_list[i], he->h_addrtype == AF_INET ? 4 : 6));
	results.prepend(KResolverEntry(sa, socktype, proto, canon, m_hostname));
	// qDebug("KStandardWorker::processResults: adding %s", sa.toString().latin1());
      }
    //  qDebug("KStandardWorker::processResults: added %d entries", i);
  }

#else  // HAVE_GETADDRINFO

  class GetAddrInfoThread: public KResolverWorkerBase
  {
  public:
    QCString m_node;
    QCString m_serv;
    int m_af;
    int m_flags;
    KResolverResults& results;

    GetAddrInfoThread(const char* node, const char* serv, int af, int flags,
		      KResolverResults* res) :
      m_node(node), m_serv(serv), m_af(af), m_flags(flags), results(*res)
    { }

    ~GetAddrInfoThread()
    { }

    virtual bool preprocess()
    { return true; }

    virtual bool run();

    void processResults(addrinfo* ai, int ret_code, KResolverResults& rr);
  };

  bool GetAddrInfoThread::run()
  {
    // check blacklist
    if ((m_af != AF_INET && m_af != AF_UNSPEC) && 
	KBlacklistWorker::isBlacklisted(QString::fromLatin1(m_node)))
      {
	results.setError(KResolver::NoName);
	finished();
	return false;		// failed
      }

    do
      {
	ResolverLocker resLock( this );

	// process hints
	addrinfo hint;
	memset(&hint, 0, sizeof(hint));
	hint.ai_family = m_af;
	hint.ai_socktype = socketType();
	hint.ai_protocol = protocol();

	if (hint.ai_socktype == 0)
	  hint.ai_socktype = SOCK_STREAM; // default

	if (m_flags & KResolver::Passive)
	  hint.ai_flags |= AI_PASSIVE;
	if (m_flags & KResolver::CanonName)
	  hint.ai_flags |= AI_CANONNAME;
# ifdef AI_NUMERICHOST
	if (m_flags & KResolver::NoResolve)
	  hint.ai_flags |= AI_NUMERICHOST;
# endif
# ifdef AI_ADDRCONFIG
	hint.ai_flags |= AI_ADDRCONFIG;
# endif

	// now we do the blocking processing
	if (m_node.isEmpty())
	  m_node = "*";

	addrinfo *result;
	int res = getaddrinfo(m_node, m_serv, &hint, &result);
	//    kdDebug(179) << k_funcinfo << "getaddrinfo(\""
	//		 << m_node << "\", \"" << m_serv << "\", af="
	//		 << m_af << ") returned " << res << endl;

	if (res != 0)
	  {
	    if (checkResolver())
	      {
		// resolver requires reinitialisation
		resLock.openClose();
		continue;
	      }

	    switch (res)
	      {
	      case EAI_BADFLAGS:
		results.setError(KResolver::BadFlags);
		break;

#ifdef EAI_NODATA
		// In some systems, EAI_NODATA was #define'd to EAI_NONAME which would break this case.
#if EAI_NODATA != EAI_NONAME
	      case EAI_NODATA:	// it was removed in RFC 3493
#endif
#endif
	      case EAI_NONAME:
		results.setError(KResolver::NoName);
		break;

	      case EAI_AGAIN:
		results.setError(KResolver::TryAgain);
		break;

	      case EAI_FAIL:
		results.setError(KResolver::NonRecoverable);
		break;

	      case EAI_FAMILY:
		results.setError(KResolver::UnsupportedFamily);
		break;

	      case EAI_SOCKTYPE:
		results.setError(KResolver::UnsupportedSocketType);
		break;

	      case EAI_SERVICE:
		results.setError(KResolver::UnsupportedService);
		break;

	      case EAI_MEMORY:
		results.setError(KResolver::Memory);
		break;

	      case EAI_SYSTEM:
		results.setError(KResolver::SystemError, errno);
		break;

	      default:
		results.setError(KResolver::UnknownError, errno);
		break;
	      }

	    finished();
	    return false;		// failed
	  }

	// if we are here, lookup succeeded
	QString canon;
	const char *previous_canon = 0L;