proxy/hdrs/VersionConverter.cc

/** @file

  HTTP header version converter

  @section license License

  Licensed to the Apache Software Foundation (ASF) under one
  or more contributor license agreements.  See the NOTICE file
  distributed with this work for additional information
  regarding copyright ownership.  The ASF licenses this file
  to you under the Apache License, Version 2.0 (the
  "License"); you may not use this file except in compliance
  with the License.  You may obtain a copy of the License at

      http://www.apache.org/licenses/LICENSE-2.0

  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
 */

#include "VersionConverter.h"
#include "HTTP.h"
#include "tscpp/util/LocalBuffer.h"

int
VersionConverter::convert(HTTPHdr &header, int from, int to) const
{
  int type = 0;

  switch (http_hdr_type_get(header.m_http)) {
  case HTTP_TYPE_REQUEST:
    type = 0;
    break;
  case HTTP_TYPE_RESPONSE:
    type = 1;
    break;
  case HTTP_TYPE_UNKNOWN:
    ink_abort("HTTP_TYPE_UNKNOWN");
    break;
  }

  ink_assert(MIN_VERSION <= from && from <= MAX_VERSION);
  ink_assert(MIN_VERSION <= to && to <= MAX_VERSION);

  int ret = (this->*_convert_functions[type][from - 1][to - 1])(header);
  if (ret < 0) {
    return -1;
  }

  // Check validity of all names and values
  for (auto &&mf : header) {
    if (!mf.name_is_valid(is_control_BIT | is_ws_BIT) || !mf.value_is_valid()) {
      return -1;
    }
  }

  return 0;
}

int
VersionConverter::_convert_nop(HTTPHdr &header) const
{
  return 0;
}

int
VersionConverter::_convert_req_from_1_to_2(HTTPHdr &header) const
{
  // :method
  if (MIMEField *field = header.field_find(PSEUDO_HEADER_METHOD.data(), PSEUDO_HEADER_METHOD.size()); field != nullptr) {
    int value_len;
    const char *value = header.method_get(&value_len);

    field->value_set(header.m_heap, header.m_mime, value, value_len);
  } else {
    ink_abort("initialize HTTP/2 pseudo-headers");
    return PARSE_RESULT_ERROR;
  }

  // :scheme
  if (MIMEField *field = header.field_find(PSEUDO_HEADER_SCHEME.data(), PSEUDO_HEADER_SCHEME.size()); field != nullptr) {
    int value_len;
    const char *value = header.scheme_get(&value_len);

    if (value != nullptr) {
      field->value_set(header.m_heap, header.m_mime, value, value_len);
    } else {
      field->value_set(header.m_heap, header.m_mime, URL_SCHEME_HTTPS, URL_LEN_HTTPS);
    }
  } else {
    ink_abort("initialize HTTP/2 pseudo-headers");
    return PARSE_RESULT_ERROR;
  }

  // :authority
  if (MIMEField *field = header.field_find(PSEUDO_HEADER_AUTHORITY.data(), PSEUDO_HEADER_AUTHORITY.size()); field != nullptr) {
    int value_len;
    const char *value = header.host_get(&value_len);

    if (header.is_port_in_header()) {
      int port = header.port_get();
      ts::LocalBuffer<char> buf(value_len + 8);
      char *host_and_port = buf.data();
      value_len           = snprintf(host_and_port, value_len + 8, "%.*s:%d", value_len, value, port);

      field->value_set(header.m_heap, header.m_mime, host_and_port, value_len);
    } else {
      field->value_set(header.m_heap, header.m_mime, value, value_len);
    }
  } else {
    ink_abort("initialize HTTP/2 pseudo-headers");
    return PARSE_RESULT_ERROR;
  }

  // :path
  if (MIMEField *field = header.field_find(PSEUDO_HEADER_PATH.data(), PSEUDO_HEADER_PATH.size()); field != nullptr) {
    int value_len     = 0;
    const char *value = header.path_get(&value_len);

    ts::LocalBuffer<char> buf(value_len + 1);
    char *path = buf.data();
    path[0]    = '/';
    memcpy(path + 1, value, value_len);

    field->value_set(header.m_heap, header.m_mime, path, value_len + 1);
  } else {
    ink_abort("initialize HTTP/2 pseudo-headers");
    return PARSE_RESULT_ERROR;
  }

  // TODO: remove host/Host header
  // [RFC 7540] 8.1.2.3. Clients that generate HTTP/2 requests directly SHOULD use the ":authority" pseudo-header field instead
  // of the Host header field.

  this->_remove_connection_specific_header_fields(header);

  return 0;
}

int
VersionConverter::_convert_req_from_2_to_1(HTTPHdr &header) const
{
  // HTTP Version
  header.version_set(HTTPVersion(1, 1));

  // :scheme
  if (MIMEField *field = header.field_find(PSEUDO_HEADER_SCHEME.data(), PSEUDO_HEADER_SCHEME.size());
      field != nullptr && field->value_is_valid(is_control_BIT | is_ws_BIT)) {
    int scheme_len;
    const char *scheme = field->value_get(&scheme_len);
    const char *scheme_wks;

    int scheme_wks_idx = hdrtoken_tokenize(scheme, scheme_len, &scheme_wks);

    if (!(scheme_wks_idx > 0 && hdrtoken_wks_to_token_type(scheme_wks) == HDRTOKEN_TYPE_SCHEME)) {
      // unkown scheme, validate the scheme
      if (!validate_scheme({scheme, static_cast<size_t>(scheme_len)})) {
        return PARSE_RESULT_ERROR;
      }
    }

    header.m_http->u.req.m_url_impl->set_scheme(header.m_heap, scheme, scheme_wks_idx, scheme_len, true);

    header.field_delete(field);
  } else {
    return PARSE_RESULT_ERROR;
  }

  // :authority
  if (MIMEField *field = header.field_find(PSEUDO_HEADER_AUTHORITY.data(), PSEUDO_HEADER_AUTHORITY.size());
      field != nullptr && field->value_is_valid(is_control_BIT | is_ws_BIT)) {
    int authority_len;
    const char *authority = field->value_get(&authority_len);

    header.m_http->u.req.m_url_impl->set_host(header.m_heap, authority, authority_len, true);

    header.field_delete(field);
  } else {
    return PARSE_RESULT_ERROR;
  }

  // :path
  if (MIMEField *field = header.field_find(PSEUDO_HEADER_PATH.data(), PSEUDO_HEADER_PATH.size());
      field != nullptr && field->value_is_valid(is_control_BIT | is_ws_BIT)) {
    int path_len;
    const char *path = field->value_get(&path_len);

    // cut first '/' if there, because `url_print()` add '/' before printing path
    if (path_len >= 1 && path[0] == '/') {
      ++path;
      --path_len;
    }

    header.m_http->u.req.m_url_impl->set_path(header.m_heap, path, path_len, true);

    header.field_delete(field);
  } else {
    return PARSE_RESULT_ERROR;
  }

  // :method
  if (MIMEField *field = header.field_find(PSEUDO_HEADER_METHOD.data(), PSEUDO_HEADER_METHOD.size());
      field != nullptr && field->value_is_valid(is_control_BIT | is_ws_BIT)) {
    int method_len;
    const char *method = field->value_get(&method_len);

    header.method_set(method, method_len);
    header.field_delete(field);
  } else {
    return PARSE_RESULT_ERROR;
  }

  // Combine Cookie header.([RFC 7540] 8.1.2.5.)
  if (MIMEField *field = header.field_find(MIME_FIELD_COOKIE, MIME_LEN_COOKIE); field != nullptr) {
    header.field_combine_dups(field, true, ';');
  }

  return 0;
}

int
VersionConverter::_convert_res_from_1_to_2(HTTPHdr &header) const
{
  constexpr int STATUS_VALUE_LEN = 3;

  // :status
  if (MIMEField *field = header.field_find(PSEUDO_HEADER_STATUS.data(), PSEUDO_HEADER_STATUS.size()); field != nullptr) {
    // ink_small_itoa() requires 5+ buffer length
    char status_str[STATUS_VALUE_LEN + 3];
    mime_format_int(status_str, header.status_get(), sizeof(status_str));

    field->value_set(header.m_heap, header.m_mime, status_str, STATUS_VALUE_LEN);
  } else {
    ink_abort("initialize HTTP/2 pseudo-headers");
    return PARSE_RESULT_ERROR;
  }

  this->_remove_connection_specific_header_fields(header);

  return 0;
}

int
VersionConverter::_convert_res_from_2_to_1(HTTPHdr &header) const
{
  // HTTP Version
  header.version_set(HTTPVersion(1, 1));

  // Set status from :status
  if (MIMEField *field = header.field_find(PSEUDO_HEADER_STATUS.data(), PSEUDO_HEADER_STATUS.size()); field != nullptr) {
    int status_len;
    const char *status = field->value_get(&status_len);

    header.status_set(http_parse_status(status, status + status_len));
    header.field_delete(field);
  } else {
    return -1;
  }

  return 0;
}

void
VersionConverter::_remove_connection_specific_header_fields(HTTPHdr &header) const
{
  // Intermediaries SHOULD remove connection-specific header fields.
  for (auto &&h : connection_specific_header_fields) {
    if (MIMEField *field = header.field_find(h.data(), h.size()); field != nullptr) {
      header.field_delete(field);
    }
  }
}