Function validate_hdr_content_length

src/proxy/hdrs/HTTP.cc:1245–1303

}

ParseResult
validate_hdr_content_length(HdrHeap *heap, HTTPHdrImpl *hh)
{
  MIMEField *content_length_field = mime_hdr_field_find(hh->m_fields_impl, MIME_FIELD_CONTENT_LENGTH, MIME_LEN_CONTENT_LENGTH);

  if (content_length_field) {
    // RFC 7230 section 3.3.3:
    // If a message is received with both a Transfer-Encoding and a
    // Content-Length header field, the Transfer-Encoding overrides
    // the Content-Length
    if (mime_hdr_field_find(hh->m_fields_impl, MIME_FIELD_TRANSFER_ENCODING, MIME_LEN_TRANSFER_ENCODING) != nullptr) {
      // Delete all Content-Length headers
      Dbg(dbg_ctl_http, "Transfer-Encoding header and Content-Length headers the request, removing all Content-Length headers");
      mime_hdr_field_delete(heap, hh->m_fields_impl, content_length_field, true);
      return PARSE_RESULT_DONE;
    }

    // RFC 7230 section 3.3.3:
    // If a message is received without Transfer-Encoding and with
    // either multiple Content-Length header fields having differing
    // field-values or a single Content-Length header field having an
    // invalid value, then the message framing is invalid and the
    // recipient MUST treat it as an unrecoverable error.  If this is a
    // request message, the server MUST respond with a 400 (Bad Request)
    // status code and then close the connection
    std::string_view value = content_length_field->value_get();

    // RFC 9110 section 8.6.
    // Content-Length = 1*DIGIT
    //
    if (value.empty()) {
      Dbg(dbg_ctl_http, "Content-Length headers don't match the ABNF, returning parse error");
      return PARSE_RESULT_ERROR;
    }

    // If the content-length value contains a non-numeric value, the header is invalid
    if (std::find_if(value.cbegin(), value.cend(), [](std::string_view::value_type c) { return !std::isdigit(c); }) !=
        value.cend()) {
      Dbg(dbg_ctl_http, "Content-Length value contains non-digit, returning parse error");
      return PARSE_RESULT_ERROR;
    }

    while (content_length_field->has_dups()) {
      std::string_view value_dup = content_length_field->m_next_dup->value_get();

      if ((value.length() != value_dup.length()) || value.compare(value_dup) != 0) {
        // Values are different, parse error
        Dbg(dbg_ctl_http, "Content-Length headers don't match, returning parse error");
        return PARSE_RESULT_ERROR;
      } else {
        // Delete the duplicate since it has the same value
        Dbg(dbg_ctl_http, "Deleting duplicate Content-Length header");
        mime_hdr_field_delete(heap, hh->m_fields_impl, content_length_field->m_next_dup, false);
      }
    }
  }

  return PARSE_RESULT_DONE;