http.c

    CURLcode result = add_buffer(in, s, strlen(s));
    free(s);
    return result;
  }
  /* If we failed, we cleanup the whole buffer and return error */
  if(in->buffer)
    free(in->buffer);
  free(in);
  return CURLE_OUT_OF_MEMORY;
}

/*
 * add_buffer() appends a memory chunk to the existing buffer
 */
static
CURLcode add_buffer(send_buffer *in, const void *inptr, size_t size)
{
  char *new_rb;
  size_t new_size;

  if(!in->buffer ||
     ((in->size_used + size) > (in->size_max - 1))) {
    new_size = (in->size_used+size)*2;
    if(in->buffer)
      /* we have a buffer, enlarge the existing one */
      new_rb = (char *)realloc(in->buffer, new_size);
    else
      /* create a new buffer */
      new_rb = (char *)malloc(new_size);

    if(!new_rb) {
      /* If we failed, we cleanup the whole buffer and return error */
      Curl_safefree(in->buffer);
      free(in);
      return CURLE_OUT_OF_MEMORY;
    }

    in->buffer = new_rb;
    in->size_max = new_size;
  }
  memcpy(&in->buffer[in->size_used], inptr, size);

  in->size_used += size;

  return CURLE_OK;
}

/* end of the add_buffer functions */
/* ------------------------------------------------------------------------- */

/*
 * Curl_compareheader()
 *
 * Returns TRUE if 'headerline' contains the 'header' with given 'content'.
 * Pass headers WITH the colon.
 */
bool
Curl_compareheader(const char *headerline, /* line to check */
                   const char *header,  /* header keyword _with_ colon */
                   const char *content) /* content string to find */
{
  /* RFC2616, section 4.2 says: "Each header field consists of a name followed
   * by a colon (":") and the field value. Field names are case-insensitive.
   * The field value MAY be preceded by any amount of LWS, though a single SP
   * is preferred." */

  size_t hlen = strlen(header);
  size_t clen;
  size_t len;
  const char *start;
  const char *end;

  if(!strnequal(headerline, header, hlen))
    return FALSE; /* doesn't start with header */

  /* pass the header */
  start = &headerline[hlen];

  /* pass all white spaces */
  while(*start && ISSPACE(*start))
    start++;

  /* find the end of the header line */
  end = strchr(start, '\r'); /* lines end with CRLF */
  if(!end) {
    /* in case there's a non-standard compliant line here */
    end = strchr(start, '\n');

    if(!end)
      /* hm, there's no line ending here, use the zero byte! */
      end = strchr(start, '\0');
  }

  len = end-start; /* length of the content part of the input line */
  clen = strlen(content); /* length of the word to find */

  /* find the content string in the rest of the line */
  for(;len>=clen;len--, start++) {
    if(strnequal(start, content, clen))
      return TRUE; /* match! */
  }

  return FALSE; /* no match */
}

/*
 * Curl_proxyCONNECT() requires that we're connected to a HTTP proxy. This
 * function will issue the necessary commands to get a seamless tunnel through
 * this proxy. After that, the socket can be used just as a normal socket.
 *
 * This badly needs to be rewritten. CONNECT should be sent and dealt with
 * like any ordinary HTTP request, and not specially crafted like this. This
 * function only remains here like this for now since the rewrite is a bit too
 * much work to do at the moment.
 *
 * This function is BLOCKING which is nasty for all multi interface using apps.
 */

CURLcode Curl_proxyCONNECT(struct connectdata *conn,
                           int sockindex,
                           char *hostname,
                           unsigned short remote_port)
{
  int subversion=0;
  struct SessionHandle *data=conn->data;
  struct Curl_transfer_keeper *k = &data->reqdata.keep;
  CURLcode result;
  int res;
  long timeout =
    data->set.timeout?data->set.timeout:3600000; /* in milliseconds */
  curl_socket_t tunnelsocket = conn->sock[sockindex];
  curl_off_t cl=0;
  bool closeConnection = FALSE;
  long check;

#define SELECT_OK      0
#define SELECT_ERROR   1
#define SELECT_TIMEOUT 2
  int error = SELECT_OK;

  conn->bits.proxy_connect_closed = FALSE;

  do {
    if (!conn->bits.tunnel_connecting) { /* BEGIN CONNECT PHASE */
      char *host_port;
      send_buffer *req_buffer;

      infof(data, "Establish HTTP proxy tunnel to %s:%d\n",
            hostname, remote_port);

      if(data->reqdata.newurl) {
        /* This only happens if we've looped here due to authentication
           reasons, and we don't really use the newly cloned URL here
           then. Just free() it. */
        free(data->reqdata.newurl);
        data->reqdata.newurl = NULL;
      }

      /* initialize a dynamic send-buffer */
      req_buffer = add_buffer_init();

      if(!req_buffer)
        return CURLE_OUT_OF_MEMORY;

      host_port = aprintf("%s:%d", hostname, remote_port);
      if(!host_port) {
        free(req_buffer);
        return CURLE_OUT_OF_MEMORY;
      }

      /* Setup the proxy-authorization header, if any */
      result = Curl_http_output_auth(conn, (char *)"CONNECT", host_port, TRUE);

      if(CURLE_OK == result) {
        char *host=(char *)"";
        const char *proxyconn="";
        const char *useragent="";

        if(!checkheaders(data, "Host:")) {
          host = aprintf("Host: %s\r\n", host_port);
          if(!host) {
            free(req_buffer);
            free(host_port);
            return CURLE_OUT_OF_MEMORY;
          }
        }
        if(!checkheaders(data, "Proxy-Connection:"))
          proxyconn = "Proxy-Connection: Keep-Alive\r\n";

        if(!checkheaders(data, "User-Agent:") &&
           data->set.str[STRING_USERAGENT])
          useragent = conn->allocptr.uagent;

	/* Send the connect request to the proxy */
	/* BLOCKING */
	result =
	  add_bufferf(req_buffer,
		      "CONNECT %s:%d HTTP/1.0\r\n"
		      "%s"  /* Host: */
		      "%s"  /* Proxy-Authorization */
		      "%s"  /* User-Agent */
		      "%s", /* Proxy-Connection */
		      hostname, remote_port,
		      host,
		      conn->allocptr.proxyuserpwd?
		      conn->allocptr.proxyuserpwd:"",
		      useragent,
		      proxyconn);

	if(host && *host)
	  free(host);

	if(CURLE_OK == result)
	  result = add_custom_headers(conn, req_buffer);

	if(CURLE_OK == result)
	  /* CRLF terminate the request */
	  result = add_bufferf(req_buffer, "\r\n");

	if(CURLE_OK == result) {
	  /* Now send off the request */
	  result = add_buffer_send(req_buffer, conn,
				   &data->info.request_size, 0, sockindex);
	}
        req_buffer = NULL;
        if(result)
          failf(data, "Failed sending CONNECT to proxy");
      }
      free(host_port);
      Curl_safefree(req_buffer);
      if(result)
        return result;

      conn->bits.tunnel_connecting = TRUE;
    } /* END CONNECT PHASE */

    /* now we've issued the CONNECT and we're waiting to hear back -
       we try not to block here in multi-mode because that might be a LONG
       wait if the proxy cannot connect-through to the remote host. */

    /* if timeout is requested, find out how much remaining time we have */
    check = timeout - /* timeout time */
      Curl_tvdiff(Curl_tvnow(), conn->now); /* spent time */
    if(check <=0 ) {
      failf(data, "Proxy CONNECT aborted due to timeout");
      error = SELECT_TIMEOUT; /* already too little time */
      break;
    }

    /* if we're in multi-mode and we would block, return instead for a retry */
    if (Curl_if_multi == data->state.used_interface) {
      if (0 == Curl_socket_ready(tunnelsocket, CURL_SOCKET_BAD, 0))
        /* return so we'll be called again polling-style */
        return CURLE_OK;
      else {
        DEBUGF(infof(data,
                     "Multi mode finished polling for response from "
                     "proxy CONNECT."));
      }
    }
    else {
      DEBUGF(infof(data, "Easy mode waiting for response from proxy CONNECT."));
    }

    /* at this point, either:
       1) we're in easy-mode and so it's okay to block waiting for a CONNECT
       response
       2) we're in multi-mode and we didn't block - it's either an error or we
       now have some data waiting.
       In any case, the tunnel_connecting phase is over. */
    conn->bits.tunnel_connecting = FALSE;

    { /* BEGIN NEGOTIATION PHASE */
      size_t nread;   /* total size read */
      int perline; /* count bytes per line */
      int keepon=TRUE;
      ssize_t gotbytes;
      char *ptr;
      char *line_start;

      ptr=data->state.buffer;
      line_start = ptr;

      nread=0;
      perline=0;
      keepon=TRUE;

      while((nread<BUFSIZE) && (keepon && !error)) {

        /* if timeout is requested, find out how much remaining time we have */
        check = timeout - /* timeout time */
          Curl_tvdiff(Curl_tvnow(), conn->now); /* spent time */
        if(check <= 0) {
          failf(data, "Proxy CONNECT aborted due to timeout");
          error = SELECT_TIMEOUT; /* already too little time */
          break;
        }

        /* loop every second at least, less if the timeout is near */
        switch (Curl_socket_ready(tunnelsocket, CURL_SOCKET_BAD,
                            check<1000L?(int)check:1000)) {
        case -1: /* select() error, stop reading */
          error = SELECT_ERROR;
          failf(data, "Proxy CONNECT aborted due to select/poll error");
          break;
        case 0: /* timeout */
          break;
        default:
          res = Curl_read(conn, tunnelsocket, ptr, BUFSIZE-nread, &gotbytes);
          if(res< 0)
            /* EWOULDBLOCK */
            continue; /* go loop yourself */
          else if(res)
            keepon = FALSE;
          else if(gotbytes <= 0) {
            keepon = FALSE;
            error = SELECT_ERROR;
            failf(data, "Proxy CONNECT aborted");
          }
          else {
            /*
             * We got a whole chunk of data, which can be anything from one
             * byte to a set of lines and possibly just a piece of the last
             * line.
             */
            int i;

            nread += gotbytes;

            if(keepon > TRUE) {
              /* This means we are currently ignoring a response-body, so we
                 simply count down our counter and make sure to break out of
                 the loop when we're done! */
              cl -= gotbytes;
              if(cl<=0) {
                keepon = FALSE;
                break;
              }
            }
            else
              for(i = 0; i < gotbytes; ptr++, i++) {
                perline++; /* amount of bytes in this line so far */
                if(*ptr=='\n') {
                  char letter;
                  int writetype;

                  /* output debug if that is requested */
                  if(data->set.verbose)
                    Curl_debug(data, CURLINFO_HEADER_IN,
                               line_start, (size_t)perline, conn);

                  /* send the header to the callback */
                  writetype = CLIENTWRITE_HEADER;
                  if(data->set.include_header)
                    writetype |= CLIENTWRITE_BODY;

                  result = Curl_client_write(conn, writetype, line_start, perline);
                  if(result)
                    return result;

                  /* Newlines are CRLF, so the CR is ignored as the line isn't
                     really terminated until the LF comes. Treat a following CR
                     as end-of-headers as well.*/

                  if(('\r' == line_start[0]) ||
                     ('\n' == line_start[0])) {
                    /* end of response-headers from the proxy */
                    if(cl && (407 == k->httpcode) &&
                       !data->state.authproblem) {
                      /* If we get a 407 response code with content length
                       * when we have no auth problem, we must ignore the
                       * whole response-body */
                      keepon = 2;
                      infof(data, "Ignore %" FORMAT_OFF_T
                            " bytes of response-body\n", cl);
                      cl -= (gotbytes - i);/* remove the remaining chunk of
                                              what we already read */
                      if(cl<=0)
                        /* if the whole thing was already read, we are done! */
                        keepon=FALSE;
                    }
                    else
                      keepon = FALSE;
                    break; /* breaks out of for-loop, not switch() */
                  }

                  /* keep a backup of the position we are about to blank */
                  letter = line_start[perline];
                  line_start[perline]=0; /* zero terminate the buffer */
                  if((checkprefix("WWW-Authenticate:", line_start) &&
                      (401 == k->httpcode)) ||
                     (checkprefix("Proxy-authenticate:", line_start) &&
                      (407 == k->httpcode))) {
                    result = Curl_http_input_auth(conn, k->httpcode,
                                                  line_start);
                    if(result)
                      return result;
                  }
                  else if(checkprefix("Content-Length:", line_start)) {
                    cl = curlx_strtoofft(line_start + strlen("Content-Length:"),
                                         NULL, 10);
                  }
                  else if(Curl_compareheader(line_start,
                                             "Connection:", "close"))
                    closeConnection = TRUE;
                  else if(Curl_compareheader(line_start,
                                             "Proxy-Connection:", "close"))
                    closeConnection = TRUE;
                  else if(2 == sscanf(line_start, "HTTP/1.%d %d",
                                      &subversion,
                                      &k->httpcode)) {
                    /* store the HTTP code from the proxy */
                    data->info.httpproxycode = k->httpcode;
                  }
                  /* put back the letter we blanked out before */
                  line_start[perline]= letter;

                  perline=0; /* line starts over here */
                  line_start = ptr+1; /* this skips the zero byte we wrote */
                }
              }
          }
          break;
        } /* switch */
      } /* while there's buffer left and loop is requested */

      if(error)
        return CURLE_RECV_ERROR;

      if(data->info.httpproxycode != 200)
        /* Deal with the possibly already received authenticate
           headers. 'newurl' is set to a new URL if we must loop. */
        Curl_http_auth_act(conn);

      if (closeConnection && data->reqdata.newurl) {
        /* Connection closed by server. Don't use it anymore */
        sclose(conn->sock[sockindex]);
        conn->sock[sockindex] = CURL_SOCKET_BAD;
        break;
      }
    } /* END NEGOTIATION PHASE */
  } while(data->reqdata.newurl);

  if(200 != k->httpcode) {
    failf(data, "Received HTTP code %d from proxy after CONNECT",
          k->httpcode);

    if (closeConnection && data->reqdata.newurl)
      conn->bits.proxy_connect_closed = TRUE;

    return CURLE_RECV_ERROR;
  }

  /* If a proxy-authorization header was used for the proxy, then we should
     make sure that it isn't accidentally used for the document request
     after we've connected. So let's free and clear it here. */
  Curl_safefree(conn->allocptr.proxyuserpwd);
  conn->allocptr.proxyuserpwd = NULL;

  data->state.authproxy.done = TRUE;

  infof (data, "Proxy replied OK to CONNECT request\n");
  return CURLE_OK;
}

/*
 * Curl_http_connect() performs HTTP stuff to do at connect-time, called from
 * the generic Curl_connect().
 */
CURLcode Curl_http_connect(struct connectdata *conn, bool *done)
{
  struct SessionHandle *data;
  CURLcode result;

  data=conn->data;

  /* We default to persistent connections. We set this already in this connect
     function to make the re-use checks properly be able to check this bit. */
  conn->bits.close = FALSE;

  /* If we are not using a proxy and we want a secure connection, perform SSL
   * initialization & connection now.  If using a proxy with https, then we
   * must tell the proxy to CONNECT to the host we want to talk to.  Only
   * after the connect has occurred, can we start talking SSL
   */

  if(conn->bits.tunnel_proxy && conn->bits.httpproxy) {

    /* either SSL over proxy, or explicitly asked for */
    result = Curl_proxyCONNECT(conn, FIRSTSOCKET,
                               conn->host.name,
                               conn->remote_port);
    if(CURLE_OK != result)
      return result;
  }

  if (conn->bits.tunnel_connecting) {
    /* nothing else to do except wait right now - we're not done here. */
    return CURLE_OK;
  }

  if(!data->state.this_is_a_follow) {
    /* this is not a followed location, get the original host name */
    if (data->state.first_host)
      /* Free to avoid leaking memory on multiple requests*/
      free(data->state.first_host);

    data->state.first_host = strdup(conn->host.name);
    if(!data->state.first_host)
      return CURLE_OUT_OF_MEMORY;
  }

  if(conn->protocol & PROT_HTTPS) {
    /* perform SSL initialization */
    if(data->state.used_interface == Curl_if_multi) {
      result = Curl_https_connecting(conn, done);
      if(result)
        return result;
    }
    else {
      /* BLOCKING */
      result = Curl_ssl_connect(conn, FIRSTSOCKET);
      if(result)
        return result;
      *done = TRUE;
    }
  }
  else {
    *done = TRUE;
  }

  return CURLE_OK;
}

CURLcode Curl_https_connecting(struct connectdata *conn, bool *done)
{
  CURLcode result;
  DEBUGASSERT((conn) && (conn->protocol & PROT_HTTPS));

  /* perform SSL initialization for this socket */
  result = Curl_ssl_connect_nonblocking(conn, FIRSTSOCKET, done);
  if(result)
    return result;

  return CURLE_OK;
}

#ifdef USE_SSLEAY
/* This function is OpenSSL-specific. It should be made to query the generic
   SSL layer instead. */
int Curl_https_getsock(struct connectdata *conn,
                       curl_socket_t *socks,
                       int numsocks)
{
  if (conn->protocol & PROT_HTTPS) {
    struct ssl_connect_data *connssl = &conn->ssl[FIRSTSOCKET];

    if(!numsocks)
      return GETSOCK_BLANK;

    if (connssl->connecting_state == ssl_connect_2_writing) {
      /* write mode */
      socks[0] = conn->sock[FIRSTSOCKET];
      return GETSOCK_WRITESOCK(0);
    }
    else if (connssl->connecting_state == ssl_connect_2_reading) {
      /* read mode */
      socks[0] = conn->sock[FIRSTSOCKET];
      return GETSOCK_READSOCK(0);
    }
  }
  return CURLE_OK;
}
#else
#ifdef USE_GNUTLS
int Curl_https_getsock(struct connectdata *conn,
                       curl_socket_t *socks,
                       int numsocks)
{
  (void)conn;
  (void)socks;
  (void)numsocks;
  return GETSOCK_BLANK;
}
#else
#ifdef USE_NSS
int Curl_https_getsock(struct connectdata *conn,
                       curl_socket_t *socks,
                       int numsocks)
{
  (void)conn;
  (void)socks;
  (void)numsocks;
  return GETSOCK_BLANK;
}
#else
#ifdef USE_QSOSSL
int Curl_https_getsock(struct connectdata *conn,
                       curl_socket_t *socks,
                       int numsocks)
{
  (void)conn;
  (void)socks;
  (void)numsocks;
  return GETSOCK_BLANK;
}
#endif
#endif
#endif
#endif

/*
 * Curl_http_done() gets called from Curl_done() after a single HTTP request
 * has been performed.
 */

CURLcode Curl_http_done(struct connectdata *conn,
                        CURLcode status, bool premature)
{
  struct SessionHandle *data = conn->data;
  struct HTTP *http =data->reqdata.proto.http;
  struct Curl_transfer_keeper *k = &data->reqdata.keep;
  (void)premature; /* not used */

  /* set the proper values (possibly modified on POST) */
  conn->fread_func = data->set.fread_func; /* restore */
  conn->fread_in = data->set.in; /* restore */

  if (http == NULL)
    return CURLE_OK;

  if(http->send_buffer) {
    send_buffer *buff = http->send_buffer;

    free(buff->buffer);
    free(buff);
    http->send_buffer = NULL; /* clear the pointer */
  }

  if(HTTPREQ_POST_FORM == data->set.httpreq) {
    k->bytecount = http->readbytecount + http->writebytecount;

    Curl_formclean(&http->sendit); /* Now free that whole lot */
    if(http->form.fp) {
      /* a file being uploaded was left opened, close it! */
      fclose(http->form.fp);
      http->form.fp = NULL;
    }
  }
  else if(HTTPREQ_PUT == data->set.httpreq)
    k->bytecount = http->readbytecount + http->writebytecount;

  if (status != CURLE_OK)
    return (status);

  if(!conn->bits.retry &&
     ((http->readbytecount +
       data->reqdata.keep.headerbytecount -
       data->reqdata.keep.deductheadercount)) <= 0) {
    /* If this connection isn't simply closed to be retried, AND nothing was
       read from the HTTP server (that counts), this can't be right so we
       return an error here */
    failf(data, "Empty reply from server");
    return CURLE_GOT_NOTHING;
  }

  return CURLE_OK;
}

/* check and possibly add an Expect: header */
static CURLcode expect100(struct SessionHandle *data,
                          send_buffer *req_buffer)
{
  CURLcode result = CURLE_OK;
  data->state.expect100header = FALSE; /* default to false unless it is set
                                          to TRUE below */
  if((data->set.httpversion != CURL_HTTP_VERSION_1_0) &&
     !checkheaders(data, "Expect:")) {
    /* if not doing HTTP 1.0 or disabled explicitly, we add a Expect:
       100-continue to the headers which actually speeds up post
       operations (as there is one packet coming back from the web
       server) */
    result = add_bufferf(req_buffer,
                         "Expect: 100-continue\r\n");
    if(result == CURLE_OK)
      data->state.expect100header = TRUE;
  }
  return result;
}

static CURLcode add_custom_headers(struct connectdata *conn,
                                   send_buffer *req_buffer)
{
  char *ptr;
  struct curl_slist *headers=conn->data->set.headers;

  while(headers) {
    ptr = strchr(headers->data, ':');
    if(ptr) {
      /* we require a colon for this to be a true header */

      ptr++; /* pass the colon */
      while(*ptr && ISSPACE(*ptr))
        ptr++;

      if(*ptr) {
        /* only send this if the contents was non-blank */

        if(conn->allocptr.host &&
           /* a Host: header was sent already, don't pass on any custom Host:
              header as that will produce *two* in the same request! */
           curl_strnequal("Host:", headers->data, 5))
          ;
        else if(conn->data->set.httpreq == HTTPREQ_POST_FORM &&
                /* this header (extended by formdata.c) is sent later */
                curl_strnequal("Content-Type:", headers->data,
                               strlen("Content-Type:")))
          ;
        else {
          CURLcode result = add_bufferf(req_buffer, "%s\r\n", headers->data);
          if(result)
            return result;
        }
      }
    }
    headers = headers->next;
  }
  return CURLE_OK;
}

/*
 * Curl_http() gets called from the generic Curl_do() function when a HTTP
 * request is to be performed. This creates and sends a properly constructed
 * HTTP request.
 */
CURLcode Curl_http(struct connectdata *conn, bool *done)
{
  struct SessionHandle *data=conn->data;
  char *buf = data->state.buffer; /* this is a short cut to the buffer */
  CURLcode result=CURLE_OK;
  struct HTTP *http;
  char *ppath = data->reqdata.path;
  char *host = conn->host.name;
  const char *te = ""; /* transfer-encoding */
  char *ptr;
  char *request;
  Curl_HttpReq httpreq = data->set.httpreq;
  char *addcookies = NULL;
  curl_off_t included_body = 0;

  /* Always consider the DO phase done after this function call, even if there
     may be parts of the request that is not yet sent, since we can deal with
     the rest of the request in the PERFORM phase. */
  *done = TRUE;

  if(!data->reqdata.proto.http) {
    /* Only allocate this struct if we don't already have it! */

    http = (struct HTTP *)malloc(sizeof(struct HTTP));
    if(!http)
      return CURLE_OUT_OF_MEMORY;
    memset(http, 0, sizeof(struct HTTP));
    data->reqdata.proto.http = http;
  }
  else
    http = data->reqdata.proto.http;

  if ( (conn->protocol&(PROT_HTTP|PROT_FTP)) &&
       data->set.upload) {
    httpreq = HTTPREQ_PUT;
  }

  /* Now set the 'request' pointer to the proper request string */
  if(data->set.str[STRING_CUSTOMREQUEST])
    request = data->set.str[STRING_CUSTOMREQUEST];
  else {
    if(conn->bits.no_body)
      request = (char *)"HEAD";
    else {
      DEBUGASSERT((httpreq > HTTPREQ_NONE) && (httpreq < HTTPREQ_LAST));
      switch(httpreq) {
      case HTTPREQ_POST:
      case HTTPREQ_POST_FORM:
        request = (char *)"POST";
        break;
      case HTTPREQ_PUT:
        request = (char *)"PUT";
        break;
      default: /* this should never happen */
      case HTTPREQ_GET:
        request = (char *)"GET";
        break;
      case HTTPREQ_HEAD:
        request = (char *)"HEAD";
        break;
      }
    }
  }

  /* The User-Agent string might have been allocated in url.c already, because
     it might have been used in the proxy connect, but if we have got a header
     with the user-agent string specified, we erase the previously made string
     here. */
  if(checkheaders(data, "User-Agent:") && conn->allocptr.uagent) {
    free(conn->allocptr.uagent);
    conn->allocptr.uagent=NULL;
  }

  /* setup the authentication headers */
  result = Curl_http_output_auth(conn, request, ppath, FALSE);
  if(result)
    return result;

  if((data->state.authhost.multi || data->state.authproxy.multi) &&
     (httpreq != HTTPREQ_GET) &&
     (httpreq != HTTPREQ_HEAD)) {
    /* Auth is required and we are not authenticated yet. Make a PUT or POST
       with content-length zero as a "probe". */
    conn->bits.authneg = TRUE;
  }
  else
    conn->bits.authneg = FALSE;

  Curl_safefree(conn->allocptr.ref);
  if(data->change.referer && !checkheaders(data, "Referer:"))
    conn->allocptr.ref = aprintf("Referer: %s\r\n", data->change.referer);
  else
    conn->allocptr.ref = NULL;

  if(data->set.str[STRING_COOKIE] && !checkheaders(data, "Cookie:"))
    addcookies = data->set.str[STRING_COOKIE];

  if(!checkheaders(data, "Accept-Encoding:") &&
     data->set.str[STRING_ENCODING]) {
    Curl_safefree(conn->allocptr.accept_encoding);
    conn->allocptr.accept_encoding =
      aprintf("Accept-Encoding: %s\r\n", data->set.str[STRING_ENCODING]);
    if(!conn->allocptr.accept_encoding)
      return CURLE_OUT_OF_MEMORY;
  }

  ptr = checkheaders(data, "Transfer-Encoding:");
  if(ptr) {
    /* Some kind of TE is requested, check if 'chunked' is chosen */
    conn->bits.upload_chunky =
      Curl_compareheader(ptr, "Transfer-Encoding:", "chunked");
  }
  else {
    if (httpreq == HTTPREQ_GET)
      conn->bits.upload_chunky = FALSE;
    if(conn->bits.upload_chunky)
      te = "Transfer-Encoding: chunked\r\n";
  }

  Curl_safefree(conn->allocptr.host);

  ptr = checkheaders(data, "Host:");
  if(ptr && (!data->state.this_is_a_follow ||
             curl_strequal(data->state.first_host, conn->host.name))) {
#if !defined(CURL_DISABLE_COOKIES)
    /* If we have a given custom Host: header, we extract the host name in
       order to possibly use it for cookie reasons later on. We only allow the
       custom Host: header if this is NOT a redirect, as setting Host: in the
       redirected request is being out on thin ice. Except if the host name
       is the same as the first one! */
    char *start = ptr+strlen("Host:");
    while(*start && ISSPACE(*start ))
      start++;
    ptr = start; /* start host-scanning here */

    /* scan through the string to find the end (space or colon) */
    while(*ptr && !ISSPACE(*ptr) && !(':'==*ptr))
      ptr++;

    if(ptr != start) {
      size_t len=ptr-start;
      Curl_safefree(conn->allocptr.cookiehost);
      conn->allocptr.cookiehost = malloc(len+1);
      if(!conn->allocptr.cookiehost)
        return CURLE_OUT_OF_MEMORY;
      memcpy(conn->allocptr.cookiehost, start, len);
      conn->allocptr.cookiehost[len]=0;
    }
#endif

    conn->allocptr.host = NULL;
  }
  else {
    /* When building Host: headers, we must put the host name within
       [brackets] if the host name is a plain IPv6-address. RFC2732-style. */

    if(((conn->protocol&PROT_HTTPS) && (conn->remote_port == PORT_HTTPS)) ||
       (!(conn->protocol&PROT_HTTPS) && (conn->remote_port == PORT_HTTP)) )
      /* If (HTTPS on port 443) OR (non-HTTPS on port 80) then don't include
         the port number in the host string */
      conn->allocptr.host = aprintf("Host: %s%s%s\r\n",
                                    conn->bits.ipv6_ip?"[":"",
                                    host,
                                    conn->bits.ipv6_ip?"]":"");
    else
      conn->allocptr.host = aprintf("Host: %s%s%s:%d\r\n",
                                    conn->bits.ipv6_ip?"[":"",
                                    host,
                                    conn->bits.ipv6_ip?"]":"",
                                    conn->remote_port);

    if(!conn->allocptr.host)
      /* without Host: we can't make a nice request */
      return CURLE_OUT_OF_MEMORY;
  }

  if (conn->bits.httpproxy && !conn->bits.tunnel_proxy)  {
    /* Using a proxy but does not tunnel through it */

    /* The path sent to the proxy is in fact the entire URL. But if the remote
       host is a IDN-name, we must make sure that the request we produce only
       uses the encoded host name! */
    if(conn->host.dispname != conn->host.name) {
      char *url = data->change.url;
      ptr = strstr(url, conn->host.dispname);
      if(ptr) {
        /* This is where the display name starts in the URL, now replace this
           part with the encoded name. TODO: This method of replacing the host
           name is rather crude as I believe there's a slight risk that the
           user has entered a user name or password that contain the host name
           string. */
        size_t currlen = strlen(conn->host.dispname);
        size_t newlen = strlen(conn->host.name);
        size_t urllen = strlen(url);

        char *newurl;

        newurl = malloc(urllen + newlen - currlen + 1);
        if(newurl) {
          /* copy the part before the host name */
          memcpy(newurl, url, ptr - url);
          /* append the new host name instead of the old */
          memcpy(newurl + (ptr - url), conn->host.name, newlen);
          /* append the piece after the host name */
          memcpy(newurl + newlen + (ptr - url),
                 ptr + currlen, /* copy the trailing zero byte too */
                 urllen - (ptr-url) - currlen + 1);
          if(data->change.url_alloc)
            free(data->change.url);
          data->change.url = newurl;
          data->change.url_alloc = TRUE;
        }
        else
          return CURLE_OUT_OF_MEMORY;
      }
    }
    ppath = data->change.url;
  }
  if(HTTPREQ_POST_FORM == httpreq) {
    /* we must build the whole darned post sequence first, so that we have
       a size of the whole shebang before we start to send it */
     result = Curl_getFormData(&http->sendit, data->set.httppost,
                               checkheaders(data, "Content-Type:"),
                               &http->postsize);
     if(CURLE_OK != result) {
       /* Curl_getFormData() doesn't use failf() */
       failf(data, "failed creating formpost data");
       return result;
     }
  }


  http->p_pragma =
    (!checkheaders(data, "Pragma:") &&
     (conn->bits.httpproxy && !conn->bits.tunnel_proxy) )?
    "Pragma: no-cache\r\n":NULL;

  if(!checkheaders(data, "Accept:"))
    http->p_accept = "Accept: */*\r\n";

  if(( (HTTPREQ_POST == httpreq) ||
       (HTTPREQ_POST_FORM == httpreq) ||
       (HTTPREQ_PUT == httpreq) ) &&
     data->reqdata.resume_from) {
    /**********************************************************************
     * Resuming upload in HTTP means that we PUT or POST and that we have
     * got a resume_from value set. The resume value has already created
     * a Range: header that will be passed along. We need to "fast forward"
     * the file the given number of bytes and decrease the assume upload
     * file size before we continue this venture in the dark lands of HTTP.
     *********************************************************************/

    if(data->reqdata.resume_from < 0 ) {
      /*
       * This is meant to get the size of the present remote-file by itself.
       * We don't support this now. Bail out!
       */
       data->reqdata.resume_from = 0;
    }

    if(data->reqdata.resume_from && !data->state.this_is_a_follow) {
      /* do we still game? */
      curl_off_t passed=0;

      /* Now, let's read off the proper amount of bytes from the