src/unix/net.cpp

   1 // -*- c++ -*- ///////////////////////////////////////////////////////////////
   2 // Name:        unix/net.cpp
   3 // Purpose:     Network related wxWindows classes and functions
   4 // Author:      Karsten Ballüder
   5 // Modified by:
   6 // Created:     03.10.99
   7 // RCS-ID:      $Id$
   8 // Copyright:   (c) Karsten Ballüder
   9 // Licence:     wxWindows licence
  10 /////////////////////////////////////////////////////////////////////////////
  11
  12 #include "wx/setup.h"
  13
  14 #if wxUSE_DIALUP_MANAGER
  15
  16 #ifndef  WX_PRECOMP
  17 #   include "wx/defs.h"
  18 #endif // !PCH
  19
  20 #include "wx/string.h"
  21 #include "wx/event.h"
  22 #include "wx/net.h"
  23 #include "wx/timer.h"
  24 #include "wx/filefn.h"
  25 #include "wx/utils.h"
  26 #include "wx/log.h"
  27 #include "wx/file.h"
  28
  29 #include <stdlib.h>
  30 #include <signal.h>
  31 #include <fcntl.h>
  32 #include <unistd.h>
  33 #define __STRICT_ANSI__
  34 #include <sys/socket.h>
  35 #include <sys/types.h>
  36 #include <sys/stat.h>
  37 #include <netdb.h>
  38 #include <netinet/in.h>
  39 #include <arpa/inet.h>
  40
  41 // ----------------------------------------------------------------------------
  42 // A class which groups functions dealing with connecting to the network from a
  43 // workstation using dial-up access to the net. There is at most one instance
  44 // of this class in the program accessed via GetDialUpManager().
  45 // ----------------------------------------------------------------------------
  46
  47 /* TODO
  48  *
  49  * 1. more configurability for Unix: i.e. how to initiate the connection, how
  50  *    to check for online status, &c.
  51  * 2. add a "long Dial(long connectionId = -1)" function which asks the user
  52  *    about which connection to dial (this may be done using native dialogs
  53  *    under NT, need generic dialogs for all others) and returns the identifier
  54  *    of the selected connection (it's opaque to the application) - it may be
  55  *    reused later to dial the same connection later (or use strings instead of
  56  *    longs may be?)
  57  * 3. add an async version of dialing functions which notify the caller about
  58  *    the progress (or may be even start another thread to monitor it)
  59  * 4. the static creation/accessor functions are not MT-safe - but is this
  60  *    really crucial? I think we may suppose they're always called from the
  61  *    main thread?
  62  */
  63
  64 class WXDLLEXPORT wxDialUpManagerImpl : public wxDialUpManager
  65 {
  66 public:
  67    wxDialUpManagerImpl()
  68       {
  69          m_IsOnline = -1; // unknown
  70          m_timer = NULL;
  71          m_CanUseIfconfig = -1; // unknown
  72          m_BeaconHost = WXDIALUP_MANAGER_DEFAULT_BEACONHOST;
  73          m_BeaconPort = 80;
  74       }
  75
  76    /** Could the dialup manager be initialized correctly? If this function
  77        returns FALSE, no other functions will work neither, so it's a good idea
  78        to call this function and check its result before calling any other
  79        wxDialUpManager methods.
  80    */
  81    virtual bool IsOk() const
  82       { return TRUE; }
  83
  84    /** The simplest way to initiate a dial up: this function dials the given
  85        ISP (exact meaning of the parameter depends on the platform), returns
  86        TRUE on success or FALSE on failure and logs the appropriate error
  87        message in the latter case.
  88        @param nameOfISP optional paramater for dial program
  89        @param username unused
  90        @param password unused
  91    */
  92    virtual bool Dial(const wxString& nameOfISP,
  93                      const wxString& WXUNUSED(username),
  94                      const wxString& WXUNUSED(password));
  95
  96    /// Hang up the currently active dial up connection.
  97    virtual bool HangUp();
  98
  99    // returns TRUE if the computer is connected to the network: under Windows,
 100    // this just means that a RAS connection exists, under Unix we check that
 101    // the "well-known host" (as specified by SetWellKnownHost) is reachable
 102    virtual bool IsOnline() const
 103       {
 104          if( (! m_timer) // we are not polling, so test now:
 105              || m_IsOnline == -1
 106             )
 107             CheckStatus();
 108          return m_IsOnline != 0;
 109       }
 110
 111    // sometimes the built-in logic for determining the online status may fail,
 112    // so, in general, the user should be allowed to override it. This function
 113    // allows to forcefully set the online status - whatever our internal
 114    // algorithm may think about it.
 115    virtual void SetOnlineStatus(bool isOnline = TRUE)
 116       { m_IsOnline = isOnline; }
 117
 118    // set misc wxDialUpManager options
 119    // --------------------------------
 120
 121    // enable automatical checks for the connection status and sending of
 122    // wxEVT_DIALUP_CONNECTED/wxEVT_DIALUP_DISCONNECTED events. The interval
 123    // parameter is only for Unix where we do the check manually: under
 124    // Windows, the notification about the change of connection status is
 125    // instantenous.
 126    //
 127    // Returns FALSE if couldn't set up automatic check for online status.
 128    virtual bool EnableAutoCheckOnlineStatus(size_t nSeconds);
 129
 130    // disable automatic check for connection status change - notice that the
 131    // wxEVT_DIALUP_XXX events won't be sent any more neither.
 132    virtual void DisableAutoCheckOnlineStatus();
 133
 134    // under Unix, the value of well-known host is used to check whether we're
 135    // connected to the internet. It's unused under Windows, but this function
 136    // is always safe to call. The default value is www.yahoo.com.
 137    virtual void SetWellKnownHost(const wxString& hostname,
 138                                  int portno = 80);
 139    /** Sets the commands to start up the network and to hang up
 140        again. Used by the Unix implementations only.
 141    */
 142    virtual void SetConnectCommand(const wxString &command, const wxString &hupcmd)
 143       { m_ConnectCommand = command; m_HangUpCommand = hupcmd; }
 144
 145 private:
 146    /// -1: don´t know, 0 = no, 1 = yes
 147    int m_IsOnline;
 148
 149    ///  Can we use ifconfig to list active devices?
 150    int m_CanUseIfconfig;
 151    /// The path to ifconfig
 152    wxString m_IfconfigPath;
 153
 154    /// beacon host:
 155    wxString m_BeaconHost;
 156    /// beacon host portnumber for connect:
 157    int m_BeaconPort;
 158
 159    /// command to connect to network
 160    wxString m_ConnectCommand;
 161    /// command to hang up
 162    wxString m_HangUpCommand;
 163    /// name of ISP
 164    wxString m_ISPname;
 165    /// a timer for regular testing
 166    class AutoCheckTimer *m_timer;
 167
 168    friend class AutoCheckTimer;
 169    /// determine status
 170    void CheckStatus(void) const;
 171
 172    /// real status check
 173    void CheckStatusInternal(void);
 174 };
 175
 176
 177 class AutoCheckTimer : public wxTimer
 178 {
 179 public:
 180    AutoCheckTimer(wxDialUpManagerImpl *dupman)
 181       {
 182          m_dupman = dupman;
 183          m_started = FALSE;
 184       }
 185
 186    virtual bool Start( int millisecs = -1 )
 187       { m_started = TRUE; return wxTimer::Start(millisecs, FALSE); }
 188
 189    virtual void Notify()
 190       { wxLogTrace("Checking dial up network status."); m_dupman->CheckStatus(); }
 191
 192    virtual void Stop()
 193       { if ( m_started ) wxTimer::Stop(); }
 194 public:
 195    bool m_started;
 196    wxDialUpManagerImpl *m_dupman;
 197 };
 198
 199 bool
 200 wxDialUpManagerImpl::Dial(const wxString &isp,
 201                           const wxString & WXUNUSED(username),
 202                           const wxString & WXUNUSED(password))
 203 {
 204    if(m_IsOnline == 1)
 205       return FALSE;
 206    m_IsOnline = -1;
 207    m_ISPname = isp;
 208    wxString cmd;
 209    if(m_ConnectCommand.Find("%s"))
 210       cmd.Printf(m_ConnectCommand,m_ISPname.c_str());
 211    else
 212       cmd = m_ConnectCommand;
 213    return wxExecute(cmd, /* sync */ TRUE) == 0;
 214 }
 215
 216 bool
 217 wxDialUpManagerImpl::HangUp(void)
 218 {
 219    if(m_IsOnline == 0)
 220       return FALSE;
 221    m_IsOnline = -1;
 222    wxString cmd;
 223    if(m_HangUpCommand.Find("%s"))
 224       cmd.Printf(m_HangUpCommand,m_ISPname.c_str());
 225    else
 226       cmd = m_HangUpCommand;
 227    return wxExecute(cmd, /* sync */ TRUE) == 0;
 228 }
 229
 230
 231 bool
 232 wxDialUpManagerImpl::EnableAutoCheckOnlineStatus(size_t nSeconds)
 233 {
 234    wxASSERT(m_timer == NULL);
 235    m_timer = new AutoCheckTimer(this);
 236    bool rc = m_timer->Start(nSeconds*1000);
 237    if(! rc)
 238    {
 239       delete m_timer;
 240       m_timer = NULL;
 241    }
 242    return rc;
 243 }
 244
 245 void
 246 wxDialUpManagerImpl::DisableAutoCheckOnlineStatus()
 247 {
 248    wxASSERT(m_timer != NULL);
 249    m_timer->Stop();
 250    delete m_timer;
 251    m_timer = NULL;
 252 }
 253
 254
 255 void
 256 wxDialUpManagerImpl::SetWellKnownHost(const wxString& hostname, int portno)
 257 {
 258    /// does hostname contain a port number?
 259    wxString port = hostname.After(':');
 260    if(port.Length())
 261    {
 262       m_BeaconHost = hostname.Before(':');
 263       m_BeaconPort = atoi(port);
 264    }
 265    else
 266    {
 267       m_BeaconHost = hostname;
 268       m_BeaconPort = portno;
 269    }
 270 }
 271
 272
 273 void
 274 wxDialUpManagerImpl::CheckStatus(void) const
 275 {
 276    // This function calls the CheckStatusInternal() helper function
 277    // which is OS - specific and then sends the events.
 278
 279    int oldIsOnline = m_IsOnline;
 280    ( /* non-const */ (wxDialUpManagerImpl *)this)->CheckStatusInternal();
 281
 282    // now send the events as appropriate:
 283    if(m_IsOnline != oldIsOnline)
 284    {
 285       if(m_IsOnline)
 286          ; // send ev
 287       else
 288          ; // send ev
 289    }
 290 }
 291
 292 /*
 293   We have three methods that we can use:
 294
 295   1. test via /sbin/ifconfig and grep for "sl", "ppp", "pl"
 296      --> should be fast enough for regular polling
 297   2. test if we can reach the well known beacon host
 298      --> too slow for polling
 299   3. check /proc/net/dev on linux??
 300      This method should be preferred, if possible. Need to do more
 301      testing.
 302
 303 */
 304
 305 void
 306 wxDialUpManagerImpl::CheckStatusInternal(void)
 307 {
 308    m_IsOnline = -1;
 309
 310    // First time check for ifconfig location. We only use the variant
 311    // which does not take arguments, a la GNU.
 312    if(m_CanUseIfconfig == -1) // unknown
 313    {
 314       if(wxFileExists("/sbin/ifconfig"))
 315          m_IfconfigPath = "/sbin/ifconfig";
 316       else if(wxFileExists("/usr/sbin/ifconfig"))
 317          m_IfconfigPath = "/usr/sbin/ifconfig";
 318    }
 319
 320    wxLogNull ln; // suppress all error messages
 321    // Let´s try the ifconfig method first, should be fastest:
 322    if(m_CanUseIfconfig != 0) // unknown or yes
 323    {
 324       wxASSERT(m_IfconfigPath.length());
 325
 326       wxString tmpfile = wxGetTempFileName("_wxdialuptest");
 327       wxString cmd = "/bin/sh -c \'";
 328       cmd << m_IfconfigPath << " >" << tmpfile <<  '\'';
 329       /* I tried to add an option to wxExecute() to not close stdout,
 330          so we could let ifconfig write directly to the tmpfile, but
 331          this does not work. That should be faster, as it doesn´t call
 332          the shell first. I have no idea why. :-(  (KB) */
 333 #if 0
 334       // temporarily redirect stdout/stderr:
 335       int
 336          new_stdout = dup(STDOUT_FILENO),
 337          new_stderr = dup(STDERR_FILENO);
 338       close(STDOUT_FILENO);
 339       close(STDERR_FILENO);
 340
 341       int
 342          // new stdout:
 343          output_fd = open(tmpfile, O_CREAT|O_TRUNC, S_IRUSR|S_IWUSR),
 344          // new stderr:
 345          null_fd = open("/dev/null", O_CREAT, S_IRUSR|S_IWUSR);
 346       // verify well behaved unix behaviour:
 347       wxASSERT(output_fd == STDOUT_FILENO);
 348       wxASSERT(null_fd == STDERR_FILENO);
 349       int rc = wxExecute(m_IfconfigPath,TRUE /* sync */,NULL ,wxEXECUTE_DONT_CLOSE_FDS);
 350       close(null_fd); close(output_fd);
 351       // restore old stdout, stderr:
 352       int test;
 353       test = dup(new_stdout); close(new_stdout); wxASSERT(test == STDOUT_FILENO);
 354       test = dup(new_stderr); close(new_stderr); wxASSERT(test == STDERR_FILENO);
 355       if(rc == 0)
 356 #endif
 357       if(wxExecute(cmd,TRUE /* sync */) == 0)
 358       {
 359          m_CanUseIfconfig = 1;
 360          wxFile file;
 361          if( file.Open(tmpfile) )
 362          {
 363             char *output = new char [file.Length()+1];
 364             output[file.Length()] = '\0';
 365             if(file.Read(output,file.Length()) == file.Length())
 366             {
 367                if(strstr(output,"ppp")   // ppp
 368                   || strstr(output,"sl") // slip
 369                   || strstr(output,"pl") // plip
 370                   )
 371                   m_IsOnline = 1;
 372                else
 373                   m_IsOnline = 0;
 374             }
 375             file.Close();
 376             delete [] output;
 377          }
 378          // else m_IsOnline remains -1 as we don't know for sure
 379       }
 380       else // could not run ifconfig correctly
 381          m_CanUseIfconfig = 0; // don´t try again
 382       (void) wxRemoveFile(tmpfile);
 383       if(m_IsOnline != -1) // we are done
 384          return;
 385    }
 386
 387    // second method: try to connect to well known host:
 388    // This can be used under Win 9x, too!
 389    struct hostent     *hp;
 390    struct sockaddr_in  serv_addr;
 391    int  sockfd;
 392
 393    m_IsOnline = 0; // assume false
 394    if((hp = gethostbyname(m_BeaconHost)) == NULL)
 395       return; // no DNS no net
 396
 397    serv_addr.sin_family         = hp->h_addrtype;
 398    memcpy(&serv_addr.sin_addr,hp->h_addr, hp->h_length);
 399    serv_addr.sin_port           = htons(m_BeaconPort);
 400    if( ( sockfd = socket(hp->h_addrtype, SOCK_STREAM, 0)) < 0)
 401    {
 402       //  sys_error("cannot create socket for gw");
 403       return;
 404    }
 405    if( connect(sockfd, (struct sockaddr *) &serv_addr, sizeof(serv_addr)) < 0)
 406    {
 407       //sys_error("cannot connect to server");
 408       return;
 409    }
 410    //connected!
 411    close(sockfd);
 412 }
 413
 414
 415 /* static */
 416 wxDialUpManager *
 417 wxDialUpManager::wxDialUpManager::Create(void)
 418 {
 419    return new wxDialUpManagerImpl;
 420 }
 421
 422 #endif // wxUSE_DIALUP_MANAGER