statement.h

/*
  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.
*/
//////////////////////////////////////////////////////////////////////////////////////////////
//
// Base class for all Conditions and Operations. We share the "linked" list, and the
// resource management / requirements.
//
#pragma once

#include <string>
#include <ctime>
#include <vector>

#include "ts/ts.h"

#include "resources.h"
#include "parser.h"
#include "lulu.h"

namespace header_rewrite_ns
{
constexpr int NUM_STATE_FLAGS = 16;
constexpr int NUM_STATE_INT8S = 4;

constexpr uint64_t STATE_INT8_MASKS[NUM_STATE_INT8S] = {
  // These would change if the number of flag bits changes
  0x0000000000FF0000ULL, // Bits 16-23
  0x00000000FF000000ULL, // Bits 24-31
  0x000000FF00000000ULL, // Bits 32-39
  0x0000FF0000000000ULL, // Bits 40-47
};

constexpr uint64_t STATE_INT16_MASK = 0xFFFF000000000000ULL; // Bits 48-63
} // namespace header_rewrite_ns

// URL data (both client and server)
enum UrlQualifiers {
  URL_QUAL_NONE,
  URL_QUAL_HOST,
  URL_QUAL_PORT,
  URL_QUAL_PATH,
  URL_QUAL_QUERY,
  URL_QUAL_SCHEME,
  URL_QUAL_URL,
};

enum NextHopQualifiers {
  NEXT_HOP_NONE,
  NEXT_HOP_HOST,
  NEXT_HOP_PORT,
  NEXT_HOP_STRATEGY,
};

// NOW data
enum NowQualifiers {
  NOW_QUAL_EPOCH,
  NOW_QUAL_YEAR,
  NOW_QUAL_MONTH,
  NOW_QUAL_DAY,
  NOW_QUAL_HOUR,
  NOW_QUAL_MINUTE,
  NOW_QUAL_WEEKDAY,
  NOW_QUAL_YEARDAY,
};

// GEO data
enum GeoQualifiers {
  GEO_QUAL_COUNTRY,
  GEO_QUAL_COUNTRY_ISO,
  GEO_QUAL_ASN,
  GEO_QUAL_ASN_NAME,
};

// ID data
enum IdQualifiers {
  ID_QUAL_REQUEST,
  ID_QUAL_PROCESS,
  ID_QUAL_UNIQUE,
};

// IP
enum IpQualifiers {
  IP_QUAL_CLIENT,
  IP_QUAL_INBOUND,
  // These two might not necessarily get populated, e.g. on a cache hit.
  IP_QUAL_SERVER,
  IP_QUAL_OUTBOUND,
};

enum NetworkSessionQualifiers {
  NET_QUAL_LOCAL_ADDR,  ///< Local address.
  NET_QUAL_LOCAL_PORT,  ///< Local port.
  NET_QUAL_REMOTE_ADDR, ///< Remote address.
  NET_QUAL_REMOTE_PORT, ///< Remote port.
  NET_QUAL_TLS,         ///< TLS protocol
  NET_QUAL_H2,          ///< 'h2' or not.
  NET_QUAL_IPV4,        ///< 'ipv4' or not.
  NET_QUAL_IPV6,        ///< 'ipv6' or not.
  NET_QUAL_IP_FAMILY,   ///< IP protocol family.
  NET_QUAL_STACK,       ///< Full protocol stack.
#if TS_HAS_CRIPTS
  NET_QUAL_CERT_PEM,        ///< The PEM encoded certificate
  NET_QUAL_CERT_SIG,        ///< The signature of the certificate
  NET_QUAL_CERT_SUBJECT,    ///< The subject of the certificate
  NET_QUAL_CERT_ISSUER,     ///< The issuer of the certificate
  NET_QUAL_CERT_SERIAL,     ///< The serial number of the certificate
  NET_QUAL_CERT_NOT_BEFORE, ///< The not before date of the certificate
  NET_QUAL_CERT_NOT_AFTER,  ///< The not after date of the certificate
  NET_QUAL_CERT_VERSION,    ///< The version of the certificate
  NET_QUAL_CERT_SAN_DNS,    ///< The DNS names in the SAN
  NET_QUAL_CERT_SAN_IP,     ///< The IP addresses in the SAN
  NET_QUAL_CERT_SAN_EMAIL,  ///< The email addresses in the SAN
  NET_QUAL_CERT_SAN_URI,    ///< The URIs in the SAN
#endif
};

class Statement
{
public:
  Statement() { Dbg(dbg_ctl, "Calling CTOR for Statement"); }

  virtual ~Statement()
  {
    Dbg(dbg_ctl, "Calling DTOR for Statement");
    delete _next;
  }

  // noncopyable
  Statement(const Statement &)      = delete;
  void operator=(const Statement &) = delete;

  // Validate that this statement is allowed on the given hook. Used during parsing only.
  bool is_hook_valid(TSHttpHookID hook) const;

  // Which hooks are this "statement" applicable for? Used during parsing only.
  void
  add_allowed_hook(const TSHttpHookID hook)
  {
    _allowed_hooks.push_back(hook);
  }

  // Linked list.
  void append(Statement *stmt);

  ResourceIDs get_resource_ids() const;

  virtual void
  initialize(Parser &)
  {
    TSReleaseAssert(_initialized == false);
    initialize_hooks();

    if (need_txn_slot()) {
      _txn_slot = acquire_txn_slot();
    }
    if (need_ssn_slot()) {
      _ssn_slot = acquire_ssn_slot();
    }
    if (need_txn_private_slot()) {
      _txn_private_slot = acquire_txn_private_slot();
    }

    _initialized = true;
  }

  bool
  initialized() const
  {
    return _initialized;
  }

  void
  require_resources(const ResourceIDs ids)
  {
    _rsrc = static_cast<ResourceIDs>(_rsrc | ids);
  }

  static int acquire_txn_slot();
  static int acquire_txn_private_slot();
  static int acquire_ssn_slot();
  static int acquire_state_slot(TSUserArgType type);

protected:
  virtual void initialize_hooks();

  UrlQualifiers     parse_url_qualifier(const std::string &q) const;
  NextHopQualifiers parse_next_hop_qualifier(const std::string &q) const;
  TSHttpCntlType    parse_http_cntl_qualifier(const std::string &q) const;

  virtual bool
  need_txn_slot() const
  {
    return false;
  }

  virtual bool
  need_txn_private_slot() const
  {
    return false;
  }

  virtual bool
  need_ssn_slot() const
  {
    return false;
  }

  // Scope-aware helpers for state variable access
  uint64_t
  _get_state_data(TSUserArgType scope, const Resources &res) const
  {
    if (scope == TS_USER_ARGS_SSN) {
      return reinterpret_cast<uint64_t>(TSUserArgGet(res.state.ssnp, _ssn_slot));
    }
    return reinterpret_cast<uint64_t>(TSUserArgGet(res.state.txnp, _txn_slot));
  }

  void
  _set_state_data(TSUserArgType scope, const Resources &res, uint64_t data) const
  {
    if (scope == TS_USER_ARGS_SSN) {
      TSUserArgSet(res.state.ssnp, _ssn_slot, reinterpret_cast<void *>(data));
    } else {
      TSUserArgSet(res.state.txnp, _txn_slot, reinterpret_cast<void *>(data));
    }
  }

  bool
  _check_state_handle(TSUserArgType scope, const Resources &res) const
  {
    if (scope == TS_USER_ARGS_SSN) {
      return res.state.ssnp != nullptr;
    }
    return res.state.txnp != nullptr;
  }

  static const char *
  _scope_label(TSUserArgType scope)
  {
    return (scope == TS_USER_ARGS_SSN) ? "SESSION" : "STATE";
  }

  Statement *_next             = nullptr; // Linked list
  int        _txn_slot         = -1;
  int        _txn_private_slot = -1;
  int        _ssn_slot         = -1;

private:
  ResourceIDs               _rsrc = RSRC_NONE;
  std::vector<TSHttpHookID> _allowed_hooks;
  bool                      _initialized = false;
};

union PrivateSlotData {
  uint64_t raw;
  struct {
    uint64_t timezone  : 1; // TIMEZONE_LOCAL, or TIMEZONE_GMT
    uint64_t ip_source : 2; // IP_SRC_PEER, IP_SRC_PROXY, IP_SRC_FORWARDED, or IP_SRC_PLUGIN
    uint64_t unused    : 61;
  };
};

enum { TIMEZONE_LOCAL, TIMEZONE_GMT };

enum {
  IP_SRC_PEER,   // Immediate connection
  IP_SRC_PROXY,  // PROXY protocl
  IP_SRC_PLUGIN, // Plugin
  // IP_SRC_FORWARDED,  // Forwarded header field (TS core needs to support the header first. It can be done by a plugin as well.)
};