path: root/cups/request.c

/*
 * IPP utilities for CUPS.
 *
 * Copyright © 2007-2018 by Apple Inc.
 * Copyright © 1997-2007 by Easy Software Products.
 *
 * Licensed under Apache License v2.0.  See the file "LICENSE" for more information.
 */

/*
 * Include necessary headers...
 */

#include "cups-private.h"
#include "debug-internal.h"
#include <fcntl.h>
#include <sys/stat.h>
#if defined(_WIN32) || defined(__EMX__)
#  include <io.h>
#else
#  include <unistd.h>
#endif /* _WIN32 || __EMX__ */
#ifndef O_BINARY
#  define O_BINARY 0
#endif /* O_BINARY */
#ifndef MSG_DONTWAIT
#  define MSG_DONTWAIT 0
#endif /* !MSG_DONTWAIT */


/*
 * 'cupsDoFileRequest()' - Do an IPP request with a file.
 *
 * This function sends the IPP request and attached file to the specified
 * server, retrying and authenticating as necessary.  The request is freed with
 * @link ippDelete@.
 */

ipp_t *					/* O - Response data */
cupsDoFileRequest(http_t     *http,	/* I - Connection to server or @code CUPS_HTTP_DEFAULT@ */
                  ipp_t      *request,	/* I - IPP request */
                  const char *resource,	/* I - HTTP resource for POST */
		  const char *filename)	/* I - File to send or @code NULL@ for none */
{
  ipp_t		*response;		/* IPP response data */
  int		infile;			/* Input file */


  DEBUG_printf(("cupsDoFileRequest(http=%p, request=%p(%s), resource=\"%s\", filename=\"%s\")", (void *)http, (void *)request, request ? ippOpString(request->request.op.operation_id) : "?", resource, filename));

  if (filename)
  {
    if ((infile = open(filename, O_RDONLY | O_BINARY)) < 0)
    {
     /*
      * Can't get file information!
      */

      _cupsSetError(errno == ENOENT ? IPP_STATUS_ERROR_NOT_FOUND : IPP_STATUS_ERROR_NOT_AUTHORIZED,
                    NULL, 0);

      ippDelete(request);

      return (NULL);
    }
  }
  else
    infile = -1;

  response = cupsDoIORequest(http, request, resource, infile, -1);

  if (infile >= 0)
    close(infile);

  return (response);
}


/*
 * 'cupsDoIORequest()' - Do an IPP request with file descriptors.
 *
 * This function sends the IPP request with the optional input file "infile" to
 * the specified server, retrying and authenticating as necessary.  The request
 * is freed with @link ippDelete@.
 *
 * If "infile" is a valid file descriptor, @code cupsDoIORequest@ copies
 * all of the data from the file after the IPP request message.
 *
 * If "outfile" is a valid file descriptor, @code cupsDoIORequest@ copies
 * all of the data after the IPP response message to the file.
 *
 * @since CUPS 1.3/macOS 10.5@
 */

ipp_t *					/* O - Response data */
cupsDoIORequest(http_t     *http,	/* I - Connection to server or @code CUPS_HTTP_DEFAULT@ */
                ipp_t      *request,	/* I - IPP request */
                const char *resource,	/* I - HTTP resource for POST */
		int        infile,	/* I - File to read from or -1 for none */
		int        outfile)	/* I - File to write to or -1 for none */
{
  ipp_t		*response = NULL;	/* IPP response data */
  size_t	length = 0;		/* Content-Length value */
  http_status_t	status;			/* Status of HTTP request */
  struct stat	fileinfo;		/* File information */
  ssize_t	bytes;			/* Number of bytes read/written */
  char		buffer[32768];		/* Output buffer */


  DEBUG_printf(("cupsDoIORequest(http=%p, request=%p(%s), resource=\"%s\", infile=%d, outfile=%d)", (void *)http, (void *)request, request ? ippOpString(request->request.op.operation_id) : "?", resource, infile, outfile));

 /*
  * Range check input...
  */

  if (!request || !resource)
  {
    ippDelete(request);

    _cupsSetError(IPP_STATUS_ERROR_INTERNAL, strerror(EINVAL), 0);

    return (NULL);
  }

 /*
  * Get the default connection as needed...
  */

  if (!http && (http = _cupsConnect()) == NULL)
  {
    ippDelete(request);

    return (NULL);
  }

 /*
  * See if we have a file to send...
  */

  if (infile >= 0)
  {
    if (fstat(infile, &fileinfo))
    {
     /*
      * Can't get file information!
      */

      _cupsSetError(errno == EBADF ? IPP_STATUS_ERROR_NOT_FOUND : IPP_STATUS_ERROR_NOT_AUTHORIZED, NULL, 0);
      ippDelete(request);

      return (NULL);
    }

#ifdef _WIN32
    if (fileinfo.st_mode & _S_IFDIR)
#else
    if (S_ISDIR(fileinfo.st_mode))
#endif /* _WIN32 */
    {
     /*
      * Can't send a directory...
      */

      _cupsSetError(IPP_STATUS_ERROR_NOT_POSSIBLE, strerror(EISDIR), 0);
      ippDelete(request);

      return (NULL);
    }

#ifndef _WIN32
    if (!S_ISREG(fileinfo.st_mode))
      length = 0;			/* Chunk when piping */
    else
#endif /* !_WIN32 */
    length = ippLength(request) + (size_t)fileinfo.st_size;
  }
  else
    length = ippLength(request);

  DEBUG_printf(("2cupsDoIORequest: Request length=%ld, total length=%ld", (long)ippLength(request), (long)length));

 /*
  * Clear any "Local" authentication data since it is probably stale...
  */

  if (http->authstring && !strncmp(http->authstring, "Local ", 6))
    httpSetAuthString(http, NULL, NULL);

 /*
  * Loop until we can send the request without authorization problems.
  */

  while (response == NULL)
  {
    DEBUG_puts("2cupsDoIORequest: setup...");

   /*
    * Send the request...
    */

    status = cupsSendRequest(http, request, resource, length);

    DEBUG_printf(("2cupsDoIORequest: status=%d", status));

    if (status == HTTP_STATUS_CONTINUE && request->state == IPP_STATE_DATA && infile >= 0)
    {
      DEBUG_puts("2cupsDoIORequest: file write...");

     /*
      * Send the file with the request...
      */

#ifndef _WIN32
      if (S_ISREG(fileinfo.st_mode))
#endif /* _WIN32 */
      lseek(infile, 0, SEEK_SET);

      while ((bytes = read(infile, buffer, sizeof(buffer))) > 0)
      {
        if ((status = cupsWriteRequestData(http, buffer, (size_t)bytes))
                != HTTP_STATUS_CONTINUE)
	  break;
      }
    }

   /*
    * Get the server's response...
    */

    if (status <= HTTP_STATUS_CONTINUE || status == HTTP_STATUS_OK)
    {
      response = cupsGetResponse(http, resource);
      status   = httpGetStatus(http);
    }

    DEBUG_printf(("2cupsDoIORequest: status=%d", status));

    if (status == HTTP_STATUS_ERROR ||
        (status >= HTTP_STATUS_BAD_REQUEST && status != HTTP_STATUS_UNAUTHORIZED &&
	 status != HTTP_STATUS_UPGRADE_REQUIRED))
    {
      _cupsSetHTTPError(status);
      break;
    }

    if (response && outfile >= 0)
    {
     /*
      * Write trailing data to file...
      */

      while ((bytes = httpRead2(http, buffer, sizeof(buffer))) > 0)
	if (write(outfile, buffer, (size_t)bytes) < bytes)
	  break;
    }

    if (http->state != HTTP_STATE_WAITING)
    {
     /*
      * Flush any remaining data...
      */

      httpFlush(http);
    }
  }

 /*
  * Delete the original request and return the response...
  */

  ippDelete(request);

  return (response);
}


/*
 * 'cupsDoRequest()' - Do an IPP request.
 *
 * This function sends the IPP request to the specified server, retrying
 * and authenticating as necessary.  The request is freed with @link ippDelete@.
 */

ipp_t *					/* O - Response data */
cupsDoRequest(http_t     *http,		/* I - Connection to server or @code CUPS_HTTP_DEFAULT@ */
              ipp_t      *request,	/* I - IPP request */
              const char *resource)	/* I - HTTP resource for POST */
{
  DEBUG_printf(("cupsDoRequest(http=%p, request=%p(%s), resource=\"%s\")", (void *)http, (void *)request, request ? ippOpString(request->request.op.operation_id) : "?", resource));

  return (cupsDoIORequest(http, request, resource, -1, -1));
}


/*
 * 'cupsGetResponse()' - Get a response to an IPP request.
 *
 * Use this function to get the response for an IPP request sent using
 * @link cupsSendRequest@. For requests that return additional data, use
 * @link cupsReadResponseData@ after getting a successful response,
 * otherwise call @link httpFlush@ to complete the response processing.
 *
 * @since CUPS 1.4/macOS 10.6@
 */

ipp_t *					/* O - Response or @code NULL@ on HTTP error */
cupsGetResponse(http_t     *http,	/* I - Connection to server or @code CUPS_HTTP_DEFAULT@ */
                const char *resource)	/* I - HTTP resource for POST */
{
  http_status_t	status;			/* HTTP status */
  ipp_state_t	state;			/* IPP read state */
  ipp_t		*response = NULL;	/* IPP response */


  DEBUG_printf(("cupsGetResponse(http=%p, resource=\"%s\")", (void *)http, resource));
  DEBUG_printf(("1cupsGetResponse: http->state=%d", http ? http->state : HTTP_STATE_ERROR));

 /*
  * Connect to the default server as needed...
  */

  if (!http)
  {
    _cups_globals_t *cg = _cupsGlobals();
					/* Pointer to library globals */

    if ((http = cg->http) == NULL)
    {
      _cupsSetError(IPP_STATUS_ERROR_INTERNAL, _("No active connection."), 1);
      DEBUG_puts("1cupsGetResponse: No active connection - returning NULL.");
      return (NULL);
    }
  }

  if (http->state != HTTP_STATE_POST_RECV && http->state != HTTP_STATE_POST_SEND)
  {
    _cupsSetError(IPP_STATUS_ERROR_INTERNAL, _("No request sent."), 1);
    DEBUG_puts("1cupsGetResponse: Not in POST state - returning NULL.");
    return (NULL);
  }

 /*
  * Check for an unfinished chunked request...
  */

  if (http->data_encoding == HTTP_ENCODING_CHUNKED)
  {
   /*
    * Send a 0-length chunk to finish off the request...
    */

    DEBUG_puts("2cupsGetResponse: Finishing chunked POST...");

    if (httpWrite2(http, "", 0) < 0)
      return (NULL);
  }

 /*
  * Wait for a response from the server...
  */

  DEBUG_printf(("2cupsGetResponse: Update loop, http->status=%d...",
                http->status));

  do
  {
    status = httpUpdate(http);
  }
  while (status == HTTP_STATUS_CONTINUE);

  DEBUG_printf(("2cupsGetResponse: status=%d", status));

  if (status == HTTP_STATUS_OK)
  {
   /*
    * Get the IPP response...
    */

    response = ippNew();

    while ((state = ippRead(http, response)) != IPP_STATE_DATA)
      if (state == IPP_STATE_ERROR)
	break;

    if (state == IPP_STATE_ERROR)
    {
     /*
      * Flush remaining data and delete the response...
      */

      DEBUG_puts("1cupsGetResponse: IPP read error!");

      httpFlush(http);

      ippDelete(response);
      response = NULL;

      http->status = HTTP_STATUS_ERROR;
      http->error  = EINVAL;
    }
  }
  else if (status != HTTP_STATUS_ERROR)
  {
   /*
    * Flush any error message...
    */

    httpFlush(http);

   /*
    * Then handle encryption and authentication...
    */

    if (status == HTTP_STATUS_UNAUTHORIZED)
    {
     /*
      * See if we can do authentication...
      */

      DEBUG_puts("2cupsGetResponse: Need authorization...");

      if (!cupsDoAuthentication(http, "POST", resource))
        httpReconnect2(http, 30000, NULL);
      else
        http->status = HTTP_STATUS_CUPS_AUTHORIZATION_CANCELED;
    }

#ifdef HAVE_SSL
    else if (status == HTTP_STATUS_UPGRADE_REQUIRED)
    {
     /*
      * Force a reconnect with encryption...
      */

      DEBUG_puts("2cupsGetResponse: Need encryption...");

      if (!httpReconnect2(http, 30000, NULL))
        httpEncryption(http, HTTP_ENCRYPTION_REQUIRED);
    }
#endif /* HAVE_SSL */
  }

  if (response)
  {
    ipp_attribute_t	*attr;		/* status-message attribute */


    attr = ippFindAttribute(response, "status-message", IPP_TAG_TEXT);

    DEBUG_printf(("1cupsGetResponse: status-code=%s, status-message=\"%s\"",
                  ippErrorString(response->request.status.status_code),
                  attr ? attr->values[0].string.text : ""));

    _cupsSetError(response->request.status.status_code,
                  attr ? attr->values[0].string.text :
		      ippErrorString(response->request.status.status_code), 0);
  }

  return (response);
}


/*
 * 'cupsLastError()' - Return the last IPP status code received on the current
 *                     thread.
 */

ipp_status_t				/* O - IPP status code from last request */
cupsLastError(void)
{
  return (_cupsGlobals()->last_error);
}


/*
 * 'cupsLastErrorString()' - Return the last IPP status-message received on the
 *                           current thread.
 *
 * @since CUPS 1.2/macOS 10.5@
 */

const char *				/* O - status-message text from last request */
cupsLastErrorString(void)
{
  return (_cupsGlobals()->last_status_message);
}


/*
 * '_cupsNextDelay()' - Return the next retry delay value.
 *
 * This function currently returns the Fibonacci sequence 1 1 2 3 5 8.
 *
 * Pass 0 for the current delay value to initialize the sequence.
 */

int					/* O  - Next delay value */
_cupsNextDelay(int current,		/* I  - Current delay value or 0 */
               int *previous)		/* IO - Previous delay value */
{
  int	next;				/* Next delay value */


  if (current > 0)
  {
    next      = (current + *previous) % 12;
    *previous = next < current ? 0 : current;
  }
  else
  {
    next      = 1;
    *previous = 0;
  }

  return (next);
}


/*
 * 'cupsReadResponseData()' - Read additional data after the IPP response.
 *
 * This function is used after @link cupsGetResponse@ to read the PPD or document
 * files from @code CUPS_GET_PPD@ and @code CUPS_GET_DOCUMENT@ requests,
 * respectively.
 *
 * @since CUPS 1.4/macOS 10.6@
 */

ssize_t					/* O - Bytes read, 0 on EOF, -1 on error */
cupsReadResponseData(
    http_t *http,			/* I - Connection to server or @code CUPS_HTTP_DEFAULT@ */
    char   *buffer,			/* I - Buffer to use */
    size_t length)			/* I - Number of bytes to read */
{
 /*
  * Get the default connection as needed...
  */

  DEBUG_printf(("cupsReadResponseData(http=%p, buffer=%p, length=" CUPS_LLFMT ")", (void *)http, (void *)buffer, CUPS_LLCAST length));

  if (!http)
  {
    _cups_globals_t *cg = _cupsGlobals();
					/* Pointer to library globals */

    if ((http = cg->http) == NULL)
    {
      _cupsSetError(IPP_STATUS_ERROR_INTERNAL, _("No active connection"), 1);
      return (-1);
    }
  }

 /*
  * Then read from the HTTP connection...
  */

  return (httpRead2(http, buffer, length));
}


/*
 * 'cupsSendRequest()' - Send an IPP request.
 *
 * Use @link cupsWriteRequestData@ to write any additional data (document, PPD
 * file, etc.) for the request, @link cupsGetResponse@ to get the IPP response,
 * and @link cupsReadResponseData@ to read any additional data following the
 * response. Only one request can be sent/queued at a time per @code http_t@
 * connection.
 *
 * Returns the initial HTTP status code, which will be @code HTTP_STATUS_CONTINUE@
 * on a successful send of the request.
 *
 * Note: Unlike @link cupsDoFileRequest@, @link cupsDoIORequest@, and
 * @link cupsDoRequest@, the request is NOT freed with @link ippDelete@.
 *
 * @since CUPS 1.4/macOS 10.6@
 */

http_status_t				/* O - Initial HTTP status */
cupsSendRequest(http_t     *http,	/* I - Connection to server or @code CUPS_HTTP_DEFAULT@ */
                ipp_t      *request,	/* I - IPP request */
                const char *resource,	/* I - Resource path */
		size_t     length)	/* I - Length of data to follow or @code CUPS_LENGTH_VARIABLE@ */
{
  http_status_t		status;		/* Status of HTTP request */
  int			got_status;	/* Did we get the status? */
  ipp_state_t		state;		/* State of IPP processing */
  http_status_t		expect;		/* Expect: header to use */
  char			date[256];	/* Date: header value */
  int			digest;		/* Are we using Digest authentication? */


  DEBUG_printf(("cupsSendRequest(http=%p, request=%p(%s), resource=\"%s\", length=" CUPS_LLFMT ")", (void *)http, (void *)request, request ? ippOpString(request->request.op.operation_id) : "?", resource, CUPS_LLCAST length));

 /*
  * Range check input...
  */

  if (!request || !resource)
  {
    _cupsSetError(IPP_STATUS_ERROR_INTERNAL, strerror(EINVAL), 0);

    return (HTTP_STATUS_ERROR);
  }

 /*
  * Get the default connection as needed...
  */

  if (!http && (http = _cupsConnect()) == NULL)
    return (HTTP_STATUS_SERVICE_UNAVAILABLE);

 /*
  * If the prior request was not flushed out, do so now...
  */

  if (http->state == HTTP_STATE_GET_SEND ||
      http->state == HTTP_STATE_POST_SEND)
  {
    DEBUG_puts("2cupsSendRequest: Flush prior response.");
    httpFlush(http);
  }
  else if (http->state != HTTP_STATE_WAITING)
  {
    DEBUG_printf(("1cupsSendRequest: Unknown HTTP state (%d), "
                  "reconnecting.", http->state));
    if (httpReconnect2(http, 30000, NULL))
      return (HTTP_STATUS_ERROR);
  }

#ifdef HAVE_SSL
 /*
  * See if we have an auth-info attribute and are communicating over
  * a non-local link.  If so, encrypt the link so that we can pass
  * the authentication information securely...
  */

  if (ippFindAttribute(request, "auth-info", IPP_TAG_TEXT) &&
      !httpAddrLocalhost(http->hostaddr) && !http->tls &&
      httpEncryption(http, HTTP_ENCRYPTION_REQUIRED))
  {
    DEBUG_puts("1cupsSendRequest: Unable to encrypt connection.");
    return (HTTP_STATUS_SERVICE_UNAVAILABLE);
  }
#endif /* HAVE_SSL */

 /*
  * Reconnect if the last response had a "Connection: close"...
  */

  if (!_cups_strcasecmp(httpGetField(http, HTTP_FIELD_CONNECTION), "close"))
  {
    DEBUG_puts("2cupsSendRequest: Connection: close");
    httpClearFields(http);
    if (httpReconnect2(http, 30000, NULL))
    {
      DEBUG_puts("1cupsSendRequest: Unable to reconnect.");
      return (HTTP_STATUS_SERVICE_UNAVAILABLE);
    }
  }

 /*
  * Loop until we can send the request without authorization problems.
  */

  expect = HTTP_STATUS_CONTINUE;

  for (;;)
  {
    DEBUG_puts("2cupsSendRequest: Setup...");

   /*
    * Setup the HTTP variables needed...
    */

    httpClearFields(http);
    httpSetExpect(http, expect);
    httpSetField(http, HTTP_FIELD_CONTENT_TYPE, "application/ipp");
    httpSetField(http, HTTP_FIELD_DATE, httpGetDateString2(time(NULL), date, (int)sizeof(date)));
    httpSetLength(http, length);

    digest = http->authstring && !strncmp(http->authstring, "Digest ", 7);

    if (digest)
    {
     /*
      * Update the Digest authentication string...
      */

      _httpSetDigestAuthString(http, http->nextnonce, "POST", resource);
    }

#ifdef HAVE_GSSAPI
    if (http->authstring && !strncmp(http->authstring, "Negotiate", 9))
    {
     /*
      * Do not use cached Kerberos credentials since they will look like a
      * "replay" attack...
      */

      _cupsSetNegotiateAuthString(http, "POST", resource);
    }
#endif /* HAVE_GSSAPI */

    httpSetField(http, HTTP_FIELD_AUTHORIZATION, http->authstring);

    DEBUG_printf(("2cupsSendRequest: authstring=\"%s\"", http->authstring));

   /*
    * Try the request...
    */

    DEBUG_puts("2cupsSendRequest: Sending HTTP POST...");

    if (httpPost(http, resource))
    {
      DEBUG_puts("2cupsSendRequest: POST failed, reconnecting.");
      if (httpReconnect2(http, 30000, NULL))
      {
        DEBUG_puts("1cupsSendRequest: Unable to reconnect.");
        return (HTTP_STATUS_SERVICE_UNAVAILABLE);
      }
      else
        continue;
    }

   /*
    * Send the IPP data...
    */

    DEBUG_puts("2cupsSendRequest: Writing IPP request...");

    request->state = IPP_STATE_IDLE;
    status         = HTTP_STATUS_CONTINUE;
    got_status     = 0;

    while ((state = ippWrite(http, request)) != IPP_STATE_DATA)
    {
      if (httpCheck(http))
      {
        got_status = 1;

        _httpUpdate(http, &status);
	if (status >= HTTP_STATUS_MULTIPLE_CHOICES)
	  break;
      }
      else if (state == IPP_STATE_ERROR)
	break;
    }

    if (state == IPP_STATE_ERROR)
    {
     /*
      * We weren't able to send the IPP request. But did we already get a HTTP
      * error status?
      */

      if (!got_status || status < HTTP_STATUS_MULTIPLE_CHOICES)
      {
       /*
        * No, something else went wrong.
	*/

	DEBUG_puts("1cupsSendRequest: Unable to send IPP request.");

	http->status = HTTP_STATUS_ERROR;
	http->state  = HTTP_STATE_WAITING;

	return (HTTP_STATUS_ERROR);
      }
    }

   /*
    * Wait up to 1 second to get the 100-continue response as needed...
    */

    if (!got_status || (digest && status == HTTP_STATUS_CONTINUE))
    {
      if (expect == HTTP_STATUS_CONTINUE || digest)
      {
	DEBUG_puts("2cupsSendRequest: Waiting for 100-continue...");

	if (httpWait(http, 1000))
	  _httpUpdate(http, &status);
      }
      else if (httpCheck(http))
	_httpUpdate(http, &status);
    }

    DEBUG_printf(("2cupsSendRequest: status=%d", status));

   /*
    * Process the current HTTP status...
    */

    if (status >= HTTP_STATUS_MULTIPLE_CHOICES)
    {
      int temp_status;			/* Temporary status */

      _cupsSetHTTPError(status);

      do
      {
	temp_status = httpUpdate(http);
      }
      while (temp_status != HTTP_STATUS_ERROR &&
             http->state == HTTP_STATE_POST_RECV);

      httpFlush(http);
    }

    switch (status)
    {
      case HTTP_STATUS_CONTINUE :
      case HTTP_STATUS_OK :
      case HTTP_STATUS_ERROR :
          DEBUG_printf(("1cupsSendRequest: Returning %d.", status));
          return (status);

      case HTTP_STATUS_UNAUTHORIZED :
          if (cupsDoAuthentication(http, "POST", resource))
	  {
            DEBUG_puts("1cupsSendRequest: Returning HTTP_STATUS_CUPS_AUTHORIZATION_CANCELED.");
	    return (HTTP_STATUS_CUPS_AUTHORIZATION_CANCELED);
	  }

          DEBUG_puts("2cupsSendRequest: Reconnecting after HTTP_STATUS_UNAUTHORIZED.");

	  if (httpReconnect2(http, 30000, NULL))
	  {
	    DEBUG_puts("1cupsSendRequest: Unable to reconnect.");
	    return (HTTP_STATUS_SERVICE_UNAVAILABLE);
	  }
	  break;

#ifdef HAVE_SSL
      case HTTP_STATUS_UPGRADE_REQUIRED :
	 /*
	  * Flush any error message, reconnect, and then upgrade with
	  * encryption...
	  */

          DEBUG_puts("2cupsSendRequest: Reconnecting after "
	             "HTTP_STATUS_UPGRADE_REQUIRED.");

	  if (httpReconnect2(http, 30000, NULL))
	  {
	    DEBUG_puts("1cupsSendRequest: Unable to reconnect.");
	    return (HTTP_STATUS_SERVICE_UNAVAILABLE);
	  }

	  DEBUG_puts("2cupsSendRequest: Upgrading to TLS.");
	  if (httpEncryption(http, HTTP_ENCRYPTION_REQUIRED))
	  {
	    DEBUG_puts("1cupsSendRequest: Unable to encrypt connection.");
	    return (HTTP_STATUS_SERVICE_UNAVAILABLE);
	  }
	  break;
#endif /* HAVE_SSL */

      case HTTP_STATUS_EXPECTATION_FAILED :
	 /*
	  * Don't try using the Expect: header the next time around...
	  */

	  expect = (http_status_t)0;

          DEBUG_puts("2cupsSendRequest: Reconnecting after "
	             "HTTP_EXPECTATION_FAILED.");

	  if (httpReconnect2(http, 30000, NULL))
	  {
	    DEBUG_puts("1cupsSendRequest: Unable to reconnect.");
	    return (HTTP_STATUS_SERVICE_UNAVAILABLE);
	  }
	  break;

      default :
         /*
	  * Some other error...
	  */

	  return (status);
    }
  }
}


/*
 * 'cupsWriteRequestData()' - Write additional data after an IPP request.
 *
 * This function is used after @link cupsSendRequest@ to provide a PPD and
 * after @link cupsStartDocument@ to provide a document file.
 *
 * @since CUPS 1.4/macOS 10.6@
 */

http_status_t				/* O - @code HTTP_STATUS_CONTINUE@ if OK or HTTP status on error */
cupsWriteRequestData(
    http_t     *http,			/* I - Connection to server or @code CUPS_HTTP_DEFAULT@ */
    const char *buffer,			/* I - Bytes to write */
    size_t     length)			/* I - Number of bytes to write */
{
  int	wused;				/* Previous bytes in buffer */


 /*
  * Get the default connection as needed...
  */

  DEBUG_printf(("cupsWriteRequestData(http=%p, buffer=%p, length=" CUPS_LLFMT ")", (void *)http, (void *)buffer, CUPS_LLCAST length));

  if (!http)
  {
    _cups_globals_t *cg = _cupsGlobals();
					/* Pointer to library globals */

    if ((http = cg->http) == NULL)
    {
      _cupsSetError(IPP_STATUS_ERROR_INTERNAL, _("No active connection"), 1);
      DEBUG_puts("1cupsWriteRequestData: Returning HTTP_STATUS_ERROR.");
      return (HTTP_STATUS_ERROR);
    }
  }

 /*
  * Then write to the HTTP connection...
  */

  wused = http->wused;

  if (httpWrite2(http, buffer, length) < 0)
  {
    DEBUG_puts("1cupsWriteRequestData: Returning HTTP_STATUS_ERROR.");
    _cupsSetError(IPP_STATUS_ERROR_INTERNAL, strerror(http->error), 0);
    return (HTTP_STATUS_ERROR);
  }

 /*
  * Finally, check if we have any pending data from the server...
  */

  if (length >= HTTP_MAX_BUFFER ||
      http->wused < wused ||
      (wused > 0 && (size_t)http->wused == length))
  {
   /*
    * We've written something to the server, so check for response data...
    */

    if (_httpWait(http, 0, 1))
    {
      http_status_t	status;		/* Status from _httpUpdate */

      _httpUpdate(http, &status);
      if (status >= HTTP_STATUS_MULTIPLE_CHOICES)
      {
        _cupsSetHTTPError(status);

	do
	{
	  status = httpUpdate(http);
	}
	while (status != HTTP_STATUS_ERROR && http->state == HTTP_STATE_POST_RECV);

        httpFlush(http);
      }

      DEBUG_printf(("1cupsWriteRequestData: Returning %d.\n", status));
      return (status);
    }
  }

  DEBUG_puts("1cupsWriteRequestData: Returning HTTP_STATUS_CONTINUE.");
  return (HTTP_STATUS_CONTINUE);
}


/*
 * '_cupsConnect()' - Get the default server connection...
 */

http_t *				/* O - HTTP connection */
_cupsConnect(void)
{
  _cups_globals_t *cg = _cupsGlobals();	/* Pointer to library globals */


 /*
  * See if we are connected to the same server...
  */

  if (cg->http)
  {
   /*
    * Compare the connection hostname, port, and encryption settings to
    * the cached defaults; these were initialized the first time we
    * connected...
    */

    if (strcmp(cg->http->hostname, cg->server) ||
#ifdef AF_LOCAL
        (httpAddrFamily(cg->http->hostaddr) != AF_LOCAL && cg->ipp_port != httpAddrPort(cg->http->hostaddr)) ||
#else
        cg->ipp_port != httpAddrPort(cg->http->hostaddr) ||
#endif /* AF_LOCAL */
        (cg->http->encryption != cg->encryption &&
	 cg->http->encryption == HTTP_ENCRYPTION_NEVER))
    {
     /*
      * Need to close the current connection because something has changed...
      */

      httpClose(cg->http);
      cg->http = NULL;
    }
    else
    {
     /*
      * Same server, see if the connection is still established...
      */

      char	ch;			/* Connection check byte */
      ssize_t	n;			/* Number of bytes */

#ifdef _WIN32
      if ((n = recv(cg->http->fd, &ch, 1, MSG_PEEK)) == 0 ||
          (n < 0 && WSAGetLastError() != WSAEWOULDBLOCK))
#else
      if ((n = recv(cg->http->fd, &ch, 1, MSG_PEEK | MSG_DONTWAIT)) == 0 ||
          (n < 0 && errno != EWOULDBLOCK))
#endif /* _WIN32 */
      {
       /*
        * Nope, close the connection...
        */

	httpClose(cg->http);
	cg->http = NULL;
      }
    }
  }

 /*
  * (Re)connect as needed...
  */

  if (!cg->http)
  {
    if ((cg->http = httpConnect2(cupsServer(), ippPort(), NULL, AF_UNSPEC,
				 cupsEncryption(), 1, 30000, NULL)) == NULL)
    {
      if (errno)
        _cupsSetError(IPP_STATUS_ERROR_SERVICE_UNAVAILABLE, NULL, 0);
      else
        _cupsSetError(IPP_STATUS_ERROR_SERVICE_UNAVAILABLE,
	              _("Unable to connect to host."), 1);
    }
  }

 /*
  * Return the cached connection...
  */

  return (cg->http);
}


/*
 * '_cupsSetError()' - Set the last IPP status code and status-message.
 */

void
_cupsSetError(ipp_status_t status,	/* I - IPP status code */
              const char   *message,	/* I - status-message value */
	      int          localize)	/* I - Localize the message? */
{
  _cups_globals_t	*cg;		/* Global data */


  if (!message && errno)
  {
    message  = strerror(errno);
    localize = 0;
  }

  cg             = _cupsGlobals();
  cg->last_error = status;

  if (cg->last_status_message)
  {
    _cupsStrFree(cg->last_status_message);

    cg->last_status_message = NULL;
  }

  if (message)
  {
    if (localize)
    {
     /*
      * Get the message catalog...
      */

      if (!cg->lang_default)
	cg->lang_default = cupsLangDefault();

      cg->last_status_message = _cupsStrAlloc(_cupsLangString(cg->lang_default,
                                                              message));
    }
    else
      cg->last_status_message = _cupsStrAlloc(message);
  }

  DEBUG_printf(("4_cupsSetError: last_error=%s, last_status_message=\"%s\"",
                ippErrorString(cg->last_error), cg->last_status_message));
}


/*
 * '_cupsSetHTTPError()' - Set the last error using the HTTP status.
 */

void
_cupsSetHTTPError(http_status_t status)	/* I - HTTP status code */
{
  switch (status)
  {
    case HTTP_STATUS_NOT_FOUND :
	_cupsSetError(IPP_STATUS_ERROR_NOT_FOUND, httpStatus(status), 0);
	break;

    case HTTP_STATUS_UNAUTHORIZED :
	_cupsSetError(IPP_STATUS_ERROR_NOT_AUTHENTICATED, httpStatus(status), 0);
	break;

    case HTTP_STATUS_CUPS_AUTHORIZATION_CANCELED :
	_cupsSetError(IPP_STATUS_ERROR_CUPS_AUTHENTICATION_CANCELED, httpStatus(status), 0);
	break;

    case HTTP_STATUS_FORBIDDEN :
	_cupsSetError(IPP_STATUS_ERROR_FORBIDDEN, httpStatus(status), 0);
	break;

    case HTTP_STATUS_BAD_REQUEST :
	_cupsSetError(IPP_STATUS_ERROR_BAD_REQUEST, httpStatus(status), 0);
	break;

    case HTTP_STATUS_REQUEST_TOO_LARGE :
	_cupsSetError(IPP_STATUS_ERROR_REQUEST_VALUE, httpStatus(status), 0);
	break;

    case HTTP_STATUS_NOT_IMPLEMENTED :
	_cupsSetError(IPP_STATUS_ERROR_OPERATION_NOT_SUPPORTED, httpStatus(status), 0);
	break;

    case HTTP_STATUS_NOT_SUPPORTED :
	_cupsSetError(IPP_STATUS_ERROR_VERSION_NOT_SUPPORTED, httpStatus(status), 0);
	break;

    case HTTP_STATUS_UPGRADE_REQUIRED :
	_cupsSetError(IPP_STATUS_ERROR_CUPS_UPGRADE_REQUIRED, httpStatus(status), 0);
        break;

    case HTTP_STATUS_CUPS_PKI_ERROR :
	_cupsSetError(IPP_STATUS_ERROR_CUPS_PKI, httpStatus(status), 0);
        break;

    case HTTP_STATUS_ERROR :
	_cupsSetError(IPP_STATUS_ERROR_INTERNAL, strerror(errno), 0);
        break;

    default :
	DEBUG_printf(("4_cupsSetHTTPError: HTTP error %d mapped to "
	              "IPP_STATUS_ERROR_SERVICE_UNAVAILABLE!", status));
	_cupsSetError(IPP_STATUS_ERROR_SERVICE_UNAVAILABLE, httpStatus(status), 0);
	break;
  }
}