http.c

        /* there was body data sent beyond the initial header part, pass that
           on to the debug callback too */
        Curl_debug(conn->data, CURLINFO_DATA_OUT,
                   ptr+headlen, bodylen, conn);
      }
    }
    if(bodylen)
      /* since we sent a piece of the body here, up the byte counter for it
         accordingly */
      http->writebytecount += bodylen;

    *bytes_written += amount;

    if(http) {
      if((size_t)amount != size) {
        /* The whole request could not be sent in one system call. We must
           queue it up and send it later when we get the chance. We must not
           loop here and wait until it might work again. */

        size -= amount;

        ptr = in->buffer + amount;

        /* backup the currently set pointers */
        http->backup.fread_func = conn->fread_func;
        http->backup.fread_in = conn->fread_in;
        http->backup.postdata = http->postdata;
        http->backup.postsize = http->postsize;

        /* set the new pointers for the request-sending */
        conn->fread_func = (curl_read_callback)readmoredata;
        conn->fread_in = (void *)conn;
        http->postdata = ptr;
        http->postsize = (curl_off_t)size;

        http->send_buffer = in;
        http->sending = HTTPSEND_REQUEST;

        return CURLE_OK;
      }
      http->sending = HTTPSEND_BODY;
      /* the full buffer was sent, clean up and return */
    }
    else {
      if((size_t)amount != size)
        /* We have no continue-send mechanism now, fail. This can only happen
           when this function is used from the CONNECT sending function. We
           currently (stupidly) assume that the whole request is always sent
           away in the first single chunk.

           This needs FIXing.
        */
        return CURLE_SEND_ERROR;
      else
        conn->writechannel_inuse = FALSE;
    }
  }
  if(in->buffer)
    free(in->buffer);
  free(in);

  return res;
}


/*
 * add_bufferf() add the formatted input to the buffer.
 */
static
CURLcode add_bufferf(send_buffer *in, const char *fmt, ...)
{
  char *s;
  va_list ap;
  va_start(ap, fmt);
  s = vaprintf(fmt, ap); /* this allocs a new string to append */
  va_end(ap);

  if(s) {
    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(~size < in->size_used) {
    /* If resulting used size of send buffer would wrap size_t, cleanup
       the whole buffer and return error. Otherwise the required buffer
       size will fit into a single allocatable memory chunk */
    Curl_safefree(in->buffer);
    free(in);
    return CURLE_OUT_OF_MEMORY;
  }

  if(!in->buffer ||
     ((in->size_used + size) > (in->size_max - 1))) {

    /* If current buffer size isn't enough to hold the result, use a
       buffer size that doubles the required size. If this new size
       would wrap size_t, then just use the largest possible one */

    if((size > (size_t)-1/2) || (in->size_used > (size_t)-1/2) ||
       (~(size*2) < (in->size_used*2)))
      new_size = (size_t)-1;
    else
      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,
                           const 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;
  bool chunked_encoding = 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 */

              nread = 0; /* make next read start over in the read buffer */
              if(cl) {
                /* A Content-Length based body: simply count down the counter
                   and make sure to break out of the loop when we're done! */
                cl -= gotbytes;
                if(cl<=0) {
                  keepon = FALSE;
                  break;
                }
              }
              else {
                /* chunked-encoded body, so we need to do the chunked dance
                   properly to know when the end of the body is reached */
                CHUNKcode r;
                ssize_t tookcareof=0;

                /* now parse the chunked piece of data so that we can
                   properly tell when the stream ends */
                r = Curl_httpchunk_read(conn, ptr, gotbytes, &tookcareof);
                if(r == CHUNKE_STOP) {
                  /* we're done reading chunks! */
                  infof(data, "chunk reading DONE\n");
                  keepon = FALSE;
                }
                else
                  infof(data, "Read %d bytes of chunk, continue\n",
                        tookcareof);
              }
            }
            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 */
                    nread = 0; /* make next read start over in the read
                                  buffer */
                    if((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;

                      if(cl) {

                        infof(data, "Ignore %" FORMAT_OFF_T
                              " bytes of response-body\n", cl);
                        /* remove the remaining chunk of what we already
                           read */
                        cl -= (gotbytes - i);

                        if(cl<=0)
                          /* if the whole thing was already read, we are done!
                           */
                          keepon=FALSE;
                      }
                      else if(chunked_encoding) {
                        CHUNKcode r;
                        /* We set ignorebody true here since the chunked
                           decoder function will acknowledge that. Pay
                           attention so that this is cleared again when this
                           function returns! */
                        k->ignorebody = TRUE;
                        infof(data, "%d bytes of chunk left\n", gotbytes-i);

                        if(line_start[1] == '\n') {
                          /* this can only be a LF if the letter at index 0
                             was a CR */
                          line_start++;
                          i++;
                        }

                        /* now parse the chunked piece of data so that we can
                           properly tell when the stream ends */
                        r = Curl_httpchunk_read(conn, line_start+1,
                                                  gotbytes -i, &gotbytes);
                        if(r == CHUNKE_STOP) {
                          /* we're done reading chunks! */
                          infof(data, "chunk reading DONE\n");
                          keepon = FALSE;
                        }
                        else
                          infof(data, "Read %d bytes of chunk, continue\n",
                                gotbytes);
                      }
                      else {
                        /* without content-length or chunked encoding, we
                           can't keep the connection alive since the close is
                           the end signal so we bail out at once instead */
                        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,
                                             "Transfer-Encoding:", "chunked")) {
                    infof(data, "CONNECT responded chunked\n");
                    chunked_encoding = TRUE;
                    /* init our chunky engine */
                    Curl_httpchunk_init(conn);
                  }
                  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");
  k->ignorebody = FALSE; /* put it (back) to non-ignore state */
  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;
}

static 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. */
static 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 ftp_typecode[sizeof(";type=?")] = "";
  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 there already is a protocol-specific struct allocated for this
     sessionhandle, deal with it */
  Curl_reset_reqproto(conn);

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

    http = (struct HTTP *)calloc(sizeof(struct HTTP), 1);
    if(!http)
      return CURLE_OUT_OF_MEMORY;
    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);