Method send_headers

src/proxy/http2/Http2Stream.cc:296–400

}

void
Http2Stream::send_headers(Http2ConnectionState & /* cstate ATS_UNUSED */)
{
  if (closed) {
    return;
  }
  REMEMBER(NO_EVENT, this->reentrancy_count);

  // Convert header to HTTP/1.1 format. Trailing headers need no conversion
  // because they, by definition, do not contain pseudo headers.
  if (this->trailing_header_is_possible()) {
    Http2StreamDebug("trailing header: Skipping send_headers initialization.");
  } else {
    if (http2_convert_header_from_2_to_1_1(&_receive_header) == PARSE_RESULT_ERROR) {
      Http2StreamDebug("Error converting HTTP/2 headers to HTTP/1.1.");
      if (_receive_header.type_get() == HTTP_TYPE_REQUEST) {
        // There's no way to cause Bad Request directly at this time.
        // Set an invalid method so it causes an error later.
        _receive_header.method_set("\xffVOID", 1);
      }
    }

    if (_receive_header.type_get() == HTTP_TYPE_REQUEST) {
      // Check whether the request uses CONNECT method
      int         method_len;
      const char *method = _receive_header.method_get(&method_len);
      if (method_len == HTTP_LEN_CONNECT && strncmp(method, HTTP_METHOD_CONNECT, HTTP_LEN_CONNECT) == 0) {
        this->_is_tunneling = true;
      }
    }
    ink_release_assert(this->_sm != nullptr);
    this->_http_sm_id = this->_sm->sm_id;
  }

  // Write header to a buffer.  Borrowing logic from HttpSM::write_header_into_buffer.
  // Seems like a function like this ought to be in HTTPHdr directly
  int bufindex;
  int dumpoffset = 0;
  // The name dumpoffset is used here for parity with
  // HttpSM::write_header_into_buffer, but create an alias for clarity in the
  // use of this variable below this loop.
  int &num_header_bytes = dumpoffset;
  int  done, tmp;
  do {
    bufindex             = 0;
    tmp                  = dumpoffset;
    IOBufferBlock *block = this->_receive_buffer.get_current_block();
    if (!block) {
      this->_receive_buffer.add_block();
      block = this->_receive_buffer.get_current_block();
    }
    done        = _receive_header.print(block->end(), block->write_avail(), &bufindex, &tmp);
    dumpoffset += bufindex;
    this->_receive_buffer.fill(bufindex);
    if (!done) {
      this->_receive_buffer.add_block();
    }
  } while (!done);