/*
 * Copyright (c) 2019 Cisco and/or its affiliates.
 * Licensed 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.
 */

#ifndef __included_quic_h__
#define __included_quic_h__

#include <vnet/session/application_interface.h>

#include <vppinfra/lock.h>
#include <vppinfra/tw_timer_1t_3w_1024sl_ov.h>
#include <vppinfra/bihash_16_8.h>

#include <quicly.h>

/* QUIC log levels
 * 1 - errors
 * 2 - connection/stream events
 * 3 - packet events
 * 4 - timer events
 **/

#define QUIC_DEBUG               0
#define QUIC_TSTAMP_RESOLUTION  0.001	/* QUIC tick resolution (1ms) */
#define QUIC_TIMER_HANDLE_INVALID ((u32) ~0)
#define QUIC_SESSION_INVALID ((u32) ~0 - 1)
#define QUIC_MAX_PACKET_SIZE 1280

#define QUIC_INT_MAX  0x3FFFFFFFFFFFFFFF
#define QUIC_FIFO_SIZE (64 << 10)
#define QUIC_SEND_PACKET_VEC_SIZE 16

/* Taken from quicly.c */
#define QUICLY_QUIC_BIT 0x40

#define QUICLY_PACKET_TYPE_INITIAL (QUICLY_LONG_HEADER_BIT | QUICLY_QUIC_BIT | 0)
#define QUICLY_PACKET_TYPE_0RTT (QUICLY_LONG_HEADER_BIT | QUICLY_QUIC_BIT | 0x10)
#define QUICLY_PACKET_TYPE_HANDSHAKE (QUICLY_LONG_HEADER_BIT | QUICLY_QUIC_BIT | 0x20)
#define QUICLY_PACKET_TYPE_RETRY (QUICLY_LONG_HEADER_BIT | QUICLY_QUIC_BIT | 0x30)
#define QUICLY_PACKET_TYPE_BITMASK 0xf0

/* error codes */
#define QUIC_ERROR_FULL_FIFO 0xff10
#define QUIC_APP_ERROR_CLOSE_NOTIFY QUICLY_ERROR_FROM_APPLICATION_ERROR_CODE(0)
#define QUIC_APP_ALLOCATION_ERROR QUICLY_ERROR_FROM_APPLICATION_ERROR_CODE(0x1)
#define QUIC_APP_ACCEPT_NOTIFY_ERROR QUICLY_ERROR_FROM_APPLICATION_ERROR_CODE(0x2)
#define QUIC_APP_CONNECT_NOTIFY_ERROR QUICLY_ERROR_FROM_APPLICATION_ERROR_CODE(0x3)

#if QUIC_DEBUG
#define QUIC_DBG(_lvl, _fmt, _args...)   \
  if (_lvl <= QUIC_DEBUG)                \
    clib_warning (_fmt, ##_args)
#else
#define QUIC_DBG(_lvl, _fmt, _args...)
#endif

typedef enum quic_ctx_conn_state_
{
  QUIC_CONN_STATE_OPENED,
  QUIC_CONN_STATE_HANDSHAKE,
  QUIC_CONN_STATE_READY,
  QUIC_CONN_STATE_PASSIVE_CLOSING,
  QUIC_CONN_STATE_PASSIVE_CLOSING_APP_CLOSED,
  QUIC_CONN_STATE_PASSIVE_CLOSING_QUIC_CLOSED,
  QUIC_CONN_STATE_ACTIVE_CLOSING,
} quic_ctx_conn_state_t;


typedef enum quic_ctx_flags_
{
  QUIC_F_IS_STREAM = (1 << 0),
  QUIC_F_IS_LISTENER = (1 << 1),
} quic_ctx_flags_t;

/* This structure is used to implement the concept of VPP connection for QUIC.
 * We create one per connection and one per stream. */
typedef struct quic_ctx_
{
  union
  {
    transport_connection_t connection;
    struct
    {	      /** QUIC ctx case */
      quicly_conn_t *conn;
      u32 listener_ctx_id;
      u32 client_opaque;
      u8 *srv_hostname;
      u8 conn_state;
      u8 udp_is_ip4;
      u8 _qctx_end_marker;	/* Leave this at the end */
    };
    struct
    {	      /** STREAM ctx case */
      quicly_stream_t *stream;
      u32 quic_connection_ctx_id;
      u8 _sctx_end_marker;	/* Leave this at the end */
    };
  };
  session_handle_t udp_session_handle;
  u32 timer_handle;
  u32 parent_app_wrk_id;
  u32 parent_app_id;
  u8 flags;
} quic_ctx_t;

/* Make sure our custom fields don't overlap with the fields we use in
   .connection
*/
STATIC_ASSERT (offsetof (quic_ctx_t, _qctx_end_marker) <=
	       TRANSPORT_CONN_ID_LEN,
	       "connection data must be less than TRANSPORT_CONN_ID_LEN bytes");
STATIC_ASSERT (offsetof (quic_ctx_t, _sctx_end_marker) <=
	       TRANSPORT_CONN_ID_LEN,
	       "connection data must be less than TRANSPORT_CONN_ID_LEN bytes");

typedef enum quic_crypto_engine_
{
  CRYPTO_ENGINE_VPP,
  CRYPTO_ENGINE_PICOTLS,
} quic_crypto_engine_t;

/* single-entry session cache */
typedef struct quic_session_cache_
{
  ptls_encrypt_ticket_t super;
  uint8_t id[32];
  ptls_iovec_t data;
} quic_session_cache_t;

typedef struct quic_stream_data_
{
  u32 ctx_id;
  u32 thread_index;
  u32 app_rx_data_len;		/* bytes received, to be read by external app */
} quic_stream_data_t;

typedef struct quic_worker_ctx_
{
  CLIB_CACHE_LINE_ALIGN_MARK (cacheline0);
  int64_t time_now;				   /**< worker time */
  tw_timer_wheel_1t_3w_1024sl_ov_t timer_wheel;	   /**< worker timer wheel */
  u32 *opening_ctx_pool;
} quic_worker_ctx_t;

typedef struct quic_main_
{
  u32 app_index;
  quic_ctx_t **ctx_pool;
  quic_worker_ctx_t *wrk_ctx;
  clib_bihash_16_8_t connection_hash;	/* quic connection id -> conn handle */
  f64 tstamp_ticks_per_clock;

  ptls_cipher_suite_t ***quic_ciphers;	/* available ciphers by crypto engine */
  u8 default_cipher;
  quic_session_cache_t session_cache;

  /*
   * Config
   */
  quicly_context_t quicly_ctx;
  ptls_handshake_properties_t hs_properties;
  quicly_cid_plaintext_t next_cid;
} quic_main_t;

#endif /* __included_quic_h__ */

/*
 * fd.io coding-style-patch-verification: ON
 *
 * Local Variables:
 * eval: (c-set-style "gnu")
 * End:
 */