url.c

    conn->bits.user_passwd = old_conn->bits.user_passwd;
    if(conn->bits.user_passwd) {
      /* use the new user namd and password though */
      Curl_safefree(conn->user);
      Curl_safefree(conn->passwd);
      conn->user = old_conn->user;
      conn->passwd = old_conn->passwd;
      old_conn->user = NULL;
      old_conn->passwd = NULL;
    }

    conn->bits.proxy_user_passwd = old_conn->bits.proxy_user_passwd;
    if(conn->bits.proxy_user_passwd) {
      /* use the new proxy user name and proxy password though */
      Curl_safefree(conn->proxyuser);
      Curl_safefree(conn->proxypasswd);
      conn->proxyuser = old_conn->proxyuser;
      conn->proxypasswd = old_conn->proxypasswd;
      old_conn->proxyuser = NULL;
      old_conn->proxypasswd = NULL;
    }

    /* host can change, when doing keepalive with a proxy ! */
    if(conn->bits.proxy) {
      free(conn->host.rawalloc);
      conn->host=old_conn->host;
    }
    else
      free(old_conn->host.rawalloc); /* free the newly allocated name buffer */

    /* re-use init */
    conn->bits.reuse = TRUE; /* yes, we're re-using here */

    Curl_safefree(old_conn->user);
    Curl_safefree(old_conn->passwd);
    Curl_safefree(old_conn->proxyuser);
    Curl_safefree(old_conn->proxypasswd);
    Curl_llist_destroy(old_conn->send_pipe, NULL);
    Curl_llist_destroy(old_conn->recv_pipe, NULL);
    Curl_llist_destroy(old_conn->pend_pipe, NULL);
    Curl_safefree(old_conn->master_buffer);

    free(old_conn);          /* we don't need this anymore */

    *in_connect = conn;      /* return this instead! */

    infof(data, "Re-using existing connection! (#%ld) with host %s\n",
          conn->connectindex,
          conn->proxy.name?conn->proxy.dispname:conn->host.dispname);
  }
  else {
    /*
     * This is a brand new connection, so let's store it in the connection
     * cache of ours!
     */
    ConnectionStore(data, conn);
  }

  result = setup_range(data);
  if(result)
    return result;

  /* Continue connectdata initialization here. */

  /*
   *
   * Inherit the proper values from the urldata struct AFTER we have arranged
   * the persistent connection stuff */
  conn->fread_func = data->set.fread_func;
  conn->fread_in = data->set.in;
  conn->seek_func = data->set.seek_func;
  conn->seek_client = data->set.seek_client;

#ifndef USE_ARES
  /*************************************************************
   * Set timeout if that is being used, and we're not using an asynchronous
   * name resolve.
   *************************************************************/
  if((data->set.timeout || data->set.connecttimeout) && !data->set.no_signal) {
    /*************************************************************
     * Set signal handler to catch SIGALRM
     * Store the old value to be able to set it back later!
     *************************************************************/

#ifdef SIGALRM
#ifdef HAVE_ALARM
    long shortest;
#endif
#ifdef HAVE_SIGACTION
    struct sigaction sigact;
    sigaction(SIGALRM, NULL, &sigact);
    keep_sigact = sigact;
    keep_copysig = TRUE; /* yes, we have a copy */
    sigact.sa_handler = alarmfunc;
#ifdef SA_RESTART
    /* HPUX doesn't have SA_RESTART but defaults to that behaviour! */
    sigact.sa_flags &= ~SA_RESTART;
#endif
    /* now set the new struct */
    sigaction(SIGALRM, &sigact, NULL);
#else /* HAVE_SIGACTION */
    /* no sigaction(), revert to the much lamer signal() */
#ifdef HAVE_SIGNAL
    keep_sigact = signal(SIGALRM, alarmfunc);
#endif
#endif /* HAVE_SIGACTION */

    /* We set the timeout on the name resolving phase first, separately from
     * the download/upload part to allow a maximum time on everything. This is
     * a signal-based timeout, why it won't work and shouldn't be used in
     * multi-threaded environments. */

#ifdef HAVE_ALARM
    shortest = data->set.timeout; /* default to this timeout value */
    if(shortest && data->set.connecttimeout &&
       (data->set.connecttimeout < shortest))
      /* if both are set, pick the shortest */
      shortest = data->set.connecttimeout;
    else if(!shortest)
      /* if timeout is not set, use the connect timeout */
      shortest = data->set.connecttimeout;

    if(shortest < 1000)
      /* the alarm() function only provide integer second resolution, so if
         we want to wait less than one second we must bail out already now. */
      return CURLE_OPERATION_TIMEDOUT;

    /* alarm() makes a signal get sent when the timeout fires off, and that
       will abort system calls */
    prev_alarm = alarm((unsigned int) (shortest ? shortest/1000L : shortest));
    /* We can expect the conn->created time to be "now", as that was just
       recently set in the beginning of this function and nothing slow
       has been done since then until now. */
#endif
#endif /* SIGALRM */
  }
#endif /* USE_ARES */

  /*************************************************************
   * Resolve the name of the server or proxy
   *************************************************************/
  if(conn->bits.reuse) {
    /* re-used connection, no resolving is necessary */
    hostaddr = NULL;
    /* we'll need to clear conn->dns_entry later in Curl_disconnect() */

    if(conn->bits.proxy)
      fix_hostname(data, conn, &conn->host);
  }
  else {
    /* this is a fresh connect */

    /* set a pointer to the hostname we display */
    fix_hostname(data, conn, &conn->host);

    if(!conn->proxy.name || !*conn->proxy.name) {
      /* If not connecting via a proxy, extract the port from the URL, if it is
       * there, thus overriding any defaults that might have been set above. */
      conn->port =  conn->remote_port; /* it is the same port */

      /* Resolve target host right on */
      rc = Curl_resolv(conn, conn->host.name, (int)conn->port, &hostaddr);
      if(rc == CURLRESOLV_PENDING)
        *async = TRUE;

      else if(!hostaddr) {
        failf(data, "Couldn't resolve host '%s'", conn->host.dispname);
        result =  CURLE_COULDNT_RESOLVE_HOST;
        /* don't return yet, we need to clean up the timeout first */
      }
    }
    else {
      /* This is a proxy that hasn't been resolved yet. */

      /* IDN-fix the proxy name */
      fix_hostname(data, conn, &conn->proxy);

      /* resolve proxy */
      rc = Curl_resolv(conn, conn->proxy.name, (int)conn->port, &hostaddr);

      if(rc == CURLRESOLV_PENDING)
        *async = TRUE;

      else if(!hostaddr) {
        failf(data, "Couldn't resolve proxy '%s'", conn->proxy.dispname);
        result = CURLE_COULDNT_RESOLVE_PROXY;
        /* don't return yet, we need to clean up the timeout first */
      }
    }
  }
  *addr = hostaddr;

#if defined(HAVE_ALARM) && defined(SIGALRM) && !defined(USE_ARES)
  if((data->set.timeout || data->set.connecttimeout) && !data->set.no_signal) {
#ifdef HAVE_SIGACTION
    if(keep_copysig) {
      /* we got a struct as it looked before, now put that one back nice
         and clean */
      sigaction(SIGALRM, &keep_sigact, NULL); /* put it back */
    }
#else
#ifdef HAVE_SIGNAL
    /* restore the previous SIGALRM handler */
    signal(SIGALRM, keep_sigact);
#endif
#endif /* HAVE_SIGACTION */

    /* switch back the alarm() to either zero or to what it was before minus
       the time we spent until now! */
    if(prev_alarm) {
      /* there was an alarm() set before us, now put it back */
      unsigned long elapsed_ms = Curl_tvdiff(Curl_tvnow(), conn->created);
      unsigned long alarm_set;

      /* the alarm period is counted in even number of seconds */
      alarm_set = prev_alarm - elapsed_ms/1000;

      if(!alarm_set ||
         ((alarm_set >= 0x80000000) && (prev_alarm < 0x80000000)) ) {
        /* if the alarm time-left reached zero or turned "negative" (counted
           with unsigned values), we should fire off a SIGALRM here, but we
           won't, and zero would be to switch it off so we never set it to
           less than 1! */
        alarm(1);
        result = CURLE_OPERATION_TIMEDOUT;
        failf(data, "Previous alarm fired off!");
      }
      else
        alarm((unsigned int)alarm_set);
    }
    else
      alarm(0); /* just shut it off */
  }
#endif

  return result;
}

/* SetupConnection() is called after the name resolve initiated in
 * CreateConnection() is all done.
 *
 * NOTE: the argument 'hostaddr' is NULL when this function is called for a
 * re-used connection.
 *
 * conn->data MUST already have been setup fine (in CreateConnection)
 */

static CURLcode SetupConnection(struct connectdata *conn,
                                struct Curl_dns_entry *hostaddr,
                                bool *protocol_done)
{
  CURLcode result=CURLE_OK;
  struct SessionHandle *data = conn->data;

  Curl_pgrsTime(data, TIMER_NAMELOOKUP);

  if(conn->protocol & PROT_FILE) {
    /* There's nothing in this function to setup if we're only doing
       a file:// transfer */
    *protocol_done = TRUE;
    return result;
  }
  *protocol_done = FALSE; /* default to not done */

  /* set proxy_connect_closed to false unconditionally already here since it
     is used strictly to provide extra information to a parent function in the
     case of proxy CONNECT failures and we must make sure we don't have it
     lingering set from a previous invoke */
  conn->bits.proxy_connect_closed = FALSE;

  /*************************************************************
   * Set user-agent for HTTP
   *************************************************************/
  if((conn->protocol&PROT_HTTP) && data->set.str[STRING_USERAGENT]) {
    Curl_safefree(conn->allocptr.uagent);
    conn->allocptr.uagent =
      aprintf("User-Agent: %s\r\n", data->set.str[STRING_USERAGENT]);
    if(!conn->allocptr.uagent)
      return CURLE_OUT_OF_MEMORY;
  }

  data->req.headerbytecount = 0;

#ifdef CURL_DO_LINEEND_CONV
  data->state.crlf_conversions = 0; /* reset CRLF conversion counter */
#endif /* CURL_DO_LINEEND_CONV */

  for(;;) {
    /* loop for CURL_SERVER_CLOSED_CONNECTION */

    if(CURL_SOCKET_BAD == conn->sock[FIRSTSOCKET]) {
      bool connected = FALSE;

      /* Connect only if not already connected! */
      result = ConnectPlease(data, conn, hostaddr, &connected);

      if(connected) {
        result = Curl_protocol_connect(conn, protocol_done);
        if(CURLE_OK == result)
          conn->bits.tcpconnect = TRUE;
      }
      else
        conn->bits.tcpconnect = FALSE;

      /* if the connection was closed by the server while exchanging
         authentication informations, retry with the new set
         authentication information */
      if(conn->bits.proxy_connect_closed) {
        /* reset the error buffer */
        if(data->set.errorbuffer)
          data->set.errorbuffer[0] = '\0';
        data->state.errorbuf = FALSE;
        continue;
      }

      if(CURLE_OK != result)
        return result;
    }
    else {
      Curl_pgrsTime(data, TIMER_CONNECT); /* we're connected already */
      conn->bits.tcpconnect = TRUE;
      *protocol_done = TRUE;
      if(data->set.verbose)
        verboseconnect(conn);
    }
    /* Stop the loop now */
    break;
  }

  conn->now = Curl_tvnow(); /* time this *after* the connect is done, we
                               set this here perhaps a second time */

#ifdef __EMX__
  /* 20000330 mgs
   * the check is quite a hack...
   * we're calling _fsetmode to fix the problem with fwrite converting newline
   * characters (you get mangled text files, and corrupted binary files when
   * you download to stdout and redirect it to a file). */

  if((data->set.out)->_handle == NULL) {
    _fsetmode(stdout, "b");
  }
#endif

  return CURLE_OK;
}

CURLcode Curl_connect(struct SessionHandle *data,
                      struct connectdata **in_connect,
                      bool *asyncp,
                      bool *protocol_done)
{
  CURLcode code;
  struct Curl_dns_entry *dns;

  *asyncp = FALSE; /* assume synchronous resolves by default */

  /* call the stuff that needs to be called */
  code = CreateConnection(data, in_connect, &dns, asyncp);

  if(CURLE_OK == code) {
    /* no error */
    if((*in_connect)->send_pipe->size +
       (*in_connect)->recv_pipe->size != 0)
      /* pipelining */
      *protocol_done = TRUE;
    else {
      if(dns || !*asyncp)
        /* If an address is available it means that we already have the name
           resolved, OR it isn't async. if this is a re-used connection 'dns'
           will be NULL here. Continue connecting from here */
        code = SetupConnection(*in_connect, dns, protocol_done);
      /* else
         response will be received and treated async wise */
    }
  }

  if(CURLE_OK != code && *in_connect) {
    /* We're not allowed to return failure with memory left allocated
       in the connectdata struct, free those here */
    Curl_disconnect(*in_connect); /* close the connection */
    *in_connect = NULL;           /* return a NULL */
  }

  return code;
}

/* Call this function after Curl_connect() has returned async=TRUE and
   then a successful name resolve has been received.

   Note: this function disconnects and frees the conn data in case of
   resolve failure */
CURLcode Curl_async_resolved(struct connectdata *conn,
                             bool *protocol_done)
{
#if defined(USE_ARES) || defined(USE_THREADING_GETHOSTBYNAME) || \
    defined(USE_THREADING_GETADDRINFO)
  CURLcode code = SetupConnection(conn, conn->async.dns, protocol_done);

  if(code)
    /* We're not allowed to return failure with memory left allocated
       in the connectdata struct, free those here */
    Curl_disconnect(conn); /* close the connection */

  return code;
#else
  (void)conn;
  (void)protocol_done;
  return CURLE_OK;
#endif
}


CURLcode Curl_done(struct connectdata **connp,
                   CURLcode status,  /* an error if this is called after an
                                        error was detected */
                   bool premature)
{
  CURLcode result;
  struct connectdata *conn;
  struct SessionHandle *data;

  DEBUGASSERT(*connp);

  conn = *connp;
  data = conn->data;

  Curl_expire(data, 0); /* stop timer */

  if(Curl_removeHandleFromPipeline(data, conn->recv_pipe) &&
     conn->readchannel_inuse)
    conn->readchannel_inuse = FALSE;
  if(Curl_removeHandleFromPipeline(data, conn->send_pipe) &&
     conn->writechannel_inuse)
    conn->writechannel_inuse = FALSE;
  Curl_removeHandleFromPipeline(data, conn->pend_pipe);

  if(conn->bits.done ||
     (conn->send_pipe->size + conn->recv_pipe->size != 0 &&
      !data->set.reuse_forbid &&
      !conn->bits.close))
    /* Stop if Curl_done() has already been called or pipeline
       is not empty and we do not have to close connection. */
    return CURLE_OK;

  conn->bits.done = TRUE; /* called just now! */

  /* Cleanup possible redirect junk */
  if(data->req.newurl) {
    free(data->req.newurl);
    data->req.newurl = NULL;
  }
  if(data->req.location) {
    free(data->req.location);
    data->req.location = NULL;
  }

  if(conn->dns_entry) {
    Curl_resolv_unlock(data, conn->dns_entry); /* done with this */
    conn->dns_entry = NULL;
  }

  /* this calls the protocol-specific function pointer previously set */
  if(conn->handler->done)
    result = conn->handler->done(conn, status, premature);
  else
    result = CURLE_OK;

  Curl_pgrsDone(conn); /* done with the operation */

  /* if the transfer was completed in a paused state there can be buffered
     data left to write and then kill */
  if(data->state.tempwrite) {
    free(data->state.tempwrite);
    data->state.tempwrite = NULL;
  }

  /* for ares-using, make sure all possible outstanding requests are properly
     cancelled before we proceed */
  ares_cancel(data->state.areschannel);

  /* if data->set.reuse_forbid is TRUE, it means the libcurl client has
     forced us to close this no matter what we think.

     if conn->bits.close is TRUE, it means that the connection should be
     closed in spite of all our efforts to be nice, due to protocol
     restrictions in our or the server's end

     if premature is TRUE, it means this connection was said to be DONE before
     the entire request operation is complete and thus we can't know in what
     state it is for re-using, so we're forced to close it. In a perfect world
     we can add code that keep track of if we really must close it here or not,
     but currently we have no such detail knowledge.
  */
  if(data->set.reuse_forbid || conn->bits.close || premature) {
    CURLcode res2 = Curl_disconnect(conn); /* close the connection */

    /* If we had an error already, make sure we return that one. But
       if we got a new error, return that. */
    if(!result && res2)
      result = res2;
  }
  else {
    ConnectionDone(conn); /* the connection is no longer in use */

    /* remember the most recently used connection */
    data->state.lastconnect = conn->connectindex;

    infof(data, "Connection #%ld to host %s left intact\n",
          conn->connectindex,
          conn->bits.httpproxy?conn->proxy.dispname:conn->host.dispname);
  }

  *connp = NULL; /* to make the caller of this function better detect that
                    this was either closed or handed over to the connection
                    cache here, and therefore cannot be used from this point on
                 */

  return result;
}

/*
 * do_init() inits the readwrite session. This is inited each time (in the DO
 * function before the protocol-specific DO functions are invoked) for a
 * transfer, sometimes multiple times on the same SessionHandle. Make sure
 * nothing in here depends on stuff that are setup dynamicly for the transfer.
 */

static CURLcode do_init(struct connectdata *conn)
{
  struct SessionHandle *data = conn->data;
  struct SingleRequest *k = &data->req;

  conn->bits.done = FALSE; /* Curl_done() is not called yet */
  conn->bits.do_more = FALSE; /* by default there's no curl_do_more() to use */

  /* NB: the content encoding software depends on this initialization */
  Curl_easy_initHandleData(data);

  k->start = Curl_tvnow(); /* start time */
  k->now = k->start;   /* current time is now */
  k->header = TRUE; /* assume header */
  k->httpversion = -1; /* unknown at this point */

  k->bytecount = 0;

  k->buf = data->state.buffer;
  k->uploadbuf = data->state.uploadbuffer;
  k->hbufp = data->state.headerbuff;
  k->ignorebody=FALSE;

  Curl_pgrsTime(data, TIMER_PRETRANSFER);
  Curl_speedinit(data);

  Curl_pgrsSetUploadCounter(data, 0);
  Curl_pgrsSetDownloadCounter(data, 0);

  return CURLE_OK;
}

/*
 * do_complete is called when the DO actions are complete.
 *
 * We init chunking and trailer bits to their default values here immediately
 * before receiving any header data for the current request in the pipeline.
 */
static void do_complete(struct connectdata *conn)
{
  conn->data->req.chunk=FALSE;
  conn->data->req.trailerhdrpresent=FALSE;

  conn->data->req.maxfd = (conn->sockfd>conn->writesockfd?
                               conn->sockfd:conn->writesockfd)+1;
}

CURLcode Curl_do(struct connectdata **connp, bool *done)
{
  CURLcode result=CURLE_OK;
  struct connectdata *conn = *connp;
  struct SessionHandle *data = conn->data;

  /* setup and init stuff before DO starts, in preparing for the transfer */
  do_init(conn);

  if(conn->handler->do_it) {
    /* generic protocol-specific function pointer set in curl_connect() */
    result = conn->handler->do_it(conn, done);

    /* This was formerly done in transfer.c, but we better do it here */
    if((CURLE_SEND_ERROR == result) && conn->bits.reuse) {
      /* This was a re-use of a connection and we got a write error in the
       * DO-phase. Then we DISCONNECT this connection and have another attempt
       * to CONNECT and then DO again! The retry cannot possibly find another
       * connection to re-use, since we only keep one possible connection for
       * each.  */

      infof(data, "Re-used connection seems dead, get a new one\n");

      conn->bits.close = TRUE; /* enforce close of this connection */
      result = Curl_done(&conn, result, FALSE); /* we are so done with this */

      /* conn may no longer be a good pointer */

      /*
       * According to bug report #1330310. We need to check for
       * CURLE_SEND_ERROR here as well. I figure this could happen when the
       * request failed on a FTP connection and thus Curl_done() itself tried
       * to use the connection (again). Slight Lack of feedback in the report,
       * but I don't think this extra check can do much harm.
       */
      if((CURLE_OK == result) || (CURLE_SEND_ERROR == result)) {
        bool async;
        bool protocol_done = TRUE;

        /* Now, redo the connect and get a new connection */
        result = Curl_connect(data, connp, &async, &protocol_done);
        if(CURLE_OK == result) {
          /* We have connected or sent away a name resolve query fine */

          conn = *connp; /* setup conn to again point to something nice */
          if(async) {
            /* Now, if async is TRUE here, we need to wait for the name
               to resolve */
            result = Curl_wait_for_resolv(conn, NULL);
            if(result)
              return result;

            /* Resolved, continue with the connection */
            result = Curl_async_resolved(conn, &protocol_done);
            if(result)
              return result;
          }

          /* ... finally back to actually retry the DO phase */
          result = conn->handler->do_it(conn, done);
        }
      }
    }

    if((result == CURLE_OK) && *done)
      /* do_complete must be called after the protocol-specific DO function */
      do_complete(conn);
  }
  return result;
}

CURLcode Curl_do_more(struct connectdata *conn)
{
  CURLcode result=CURLE_OK;

  if(conn->handler->do_more)
    result = conn->handler->do_more(conn);

  if(result == CURLE_OK)
    /* do_complete must be called after the protocol-specific DO function */
    do_complete(conn);

  return result;
}

/* Called on connect, and if there's already a protocol-specific struct
   allocated for a different connection, this frees it that it can be setup
   properly later on. */
void Curl_reset_reqproto(struct connectdata *conn)
{
  struct SessionHandle *data = conn->data;
  if(data->state.proto.generic && data->state.current_conn != conn) {
    free(data->state.proto.generic);
    data->state.proto.generic = NULL;
  }
  data->state.current_conn = conn;
}