/*
 * Copyright (c) 2017-2019 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 SRC_VNET_SESSION_TRANSPORT_H_
#define SRC_VNET_SESSION_TRANSPORT_H_

#include <vnet/vnet.h>
#include <vnet/session/transport_types.h>

#define TRANSPORT_PACER_MIN_MSS 	1460
#define TRANSPORT_PACER_MIN_BURST 	TRANSPORT_PACER_MIN_MSS
#define TRANSPORT_PACER_MAX_BURST	(43 * TRANSPORT_PACER_MIN_MSS)
#define TRANSPORT_PACER_MAX_BURST_PKTS	43
#define TRANSPORT_PACER_BURSTS_PER_RTT	20
#define TRANSPORT_PACER_MIN_IDLE	100
#define TRANSPORT_PACER_IDLE_FACTOR	0.05

typedef struct _transport_options_t
{
  char *name;
  char *short_name;
  transport_tx_fn_type_t tx_type;
  transport_service_type_t service_type;
} transport_options_t;

typedef enum transport_snd_flags_
{
  TRANSPORT_SND_F_DESCHED = 1 << 0,
  TRANSPORT_SND_F_POSTPONE = 1 << 1,
  TRANSPORT_SND_N_FLAGS
} __clib_packed transport_snd_flags_t;

typedef struct transport_send_params_
{
  union
  {
    /* Used to retrieve snd params from transports */
    struct
    {
      u32 snd_space;
      u32 tx_offset;
      u16 snd_mss;
    };
    /* Used by custom tx functions */
    struct
    {
      u32 max_burst_size;
      u32 bytes_dequeued;
    };
  };
  transport_snd_flags_t flags;
} transport_send_params_t;

/*
 * Transport protocol virtual function table
 */
typedef struct _transport_proto_vft
{
  /*
   * Setup
   */
  u32 (*start_listen) (u32 session_index, transport_endpoint_cfg_t *lcl);
  u32 (*stop_listen) (u32 conn_index);
  int (*connect) (transport_endpoint_cfg_t * rmt);
  void (*half_close) (u32 conn_index, u32 thread_index);
  void (*close) (u32 conn_index, u32 thread_index);
  void (*reset) (u32 conn_index, u32 thread_index);
  void (*cleanup) (u32 conn_index, u32 thread_index);
  void (*cleanup_ho) (u32 conn_index);
  clib_error_t *(*enable) (vlib_main_t * vm, u8 is_en);

  /*
   * Transmission
   */

  u32 (*push_header) (transport_connection_t *tconn, vlib_buffer_t **b,
		      u32 n_bufs);
  int (*send_params) (transport_connection_t * tconn,
		      transport_send_params_t *sp);
  void (*update_time) (f64 time_now, u8 thread_index);
  void (*flush_data) (transport_connection_t *tconn);
  int (*custom_tx) (void *session, transport_send_params_t *sp);
  int (*app_rx_evt) (transport_connection_t *tconn);

  /*
   * Connection retrieval
   */
  transport_connection_t *(*get_connection) (u32 conn_idx, u32 thread_idx);
  transport_connection_t *(*get_listener) (u32 conn_index);
  transport_connection_t *(*get_half_open) (u32 conn_index);

  /*
   * Format
   */
  u8 *(*format_connection) (u8 * s, va_list * args);
  u8 *(*format_listener) (u8 * s, va_list * args);
  u8 *(*format_half_open) (u8 * s, va_list * args);

  /*
   *  Properties retrieval/setting
   */
  void (*get_transport_endpoint) (u32 conn_index, u32 thread_index,
				  transport_endpoint_t *tep, u8 is_lcl);
  void (*get_transport_listener_endpoint) (u32 conn_index,
					   transport_endpoint_t *tep,
					   u8 is_lcl);
  int (*attribute) (u32 conn_index, u32 thread_index, u8 is_get,
		    transport_endpt_attr_t *attr);

  /*
   * Properties
   */
  transport_options_t transport_options;
} transport_proto_vft_t;

extern transport_proto_vft_t *tp_vfts;

#define transport_proto_foreach(VAR, VAR_ALLOW_BM)                            \
  for (VAR = 0; VAR < vec_len (tp_vfts); VAR++)                               \
    if (tp_vfts[VAR].push_header != 0)                                        \
      if (VAR_ALLOW_BM & (1 << VAR))

int transport_connect (transport_proto_t tp, transport_endpoint_cfg_t * tep);
void transport_half_close (transport_proto_t tp, u32 conn_index,
			   u8 thread_index);
void transport_close (transport_proto_t tp, u32 conn_index, u8 thread_index);
void transport_reset (transport_proto_t tp, u32 conn_index, u8 thread_index);
u32 transport_start_listen (transport_proto_t tp, u32 session_index,
			    transport_endpoint_cfg_t *tep);
u32 transport_stop_listen (transport_proto_t tp, u32 conn_index);
void transport_cleanup (transport_proto_t tp, u32 conn_index,
			u8 thread_index);
void transport_cleanup_half_open (transport_proto_t tp, u32 conn_index);
void transport_get_endpoint (transport_proto_t tp, u32 conn_index,
			     u32 thread_index, transport_endpoint_t * tep,
			     u8 is_lcl);
void transport_get_listener_endpoint (transport_proto_t tp, u32 conn_index,
				      transport_endpoint_t * tep, u8 is_lcl);
int transport_connection_attribute (transport_proto_t tp, u32 conn_index,
				    u8 thread_index, u8 is_get,
				    transport_endpt_attr_t *attr);

static inline transport_connection_t *
transport_get_connection (transport_proto_t tp, u32 conn_index,
			  u8 thread_index)
{
  return tp_vfts[tp].get_connection (conn_index, thread_index);
}

static inline transport_connection_t *
transport_get_listener (transport_proto_t tp, u32 conn_index)
{
  return tp_vfts[tp].get_listener (conn_index);
}

static inline transport_connection_t *
transport_get_half_open (transport_proto_t tp, u32 conn_index)
{
  return tp_vfts[tp].get_half_open (conn_index);
}

static inline int
transport_custom_tx (transport_proto_t tp, void *s,
		     transport_send_params_t * sp)
{
  return tp_vfts[tp].custom_tx (s, sp);
}

static inline int
transport_app_rx_evt (transport_proto_t tp, u32 conn_index, u32 thread_index)
{
  transport_connection_t *tc;
  if (!tp_vfts[tp].app_rx_evt)
    return 0;
  tc = transport_get_connection (tp, conn_index, thread_index);
  return tp_vfts[tp].app_rx_evt (tc);
}

/**
 * Get send parameters for transport connection
 *
 * These include maximum tx burst, mss, tx offset and other flags
 * transport might want to provide to sessin layer
 *
 * @param tc		transport connection
 * @param sp		send paramaters
 *
 */
static inline u32
transport_connection_snd_params (transport_connection_t * tc,
				 transport_send_params_t * sp)
{
  return tp_vfts[tc->proto].send_params (tc, sp);
}

static inline u8
transport_connection_is_descheduled (transport_connection_t * tc)
{
  return ((tc->flags & TRANSPORT_CONNECTION_F_DESCHED) ? 1 : 0);
}

static inline void
transport_connection_deschedule (transport_connection_t * tc)
{
  tc->flags |= TRANSPORT_CONNECTION_F_DESCHED;
}

static inline u8
transport_connection_is_cless (transport_connection_t * tc)
{
  return ((tc->flags & TRANSPORT_CONNECTION_F_CLESS) ? 1 : 0);
}

void transport_connection_reschedule (transport_connection_t * tc);
void transport_fifos_init_ooo (transport_connection_t * tc);

/**
 * Register transport virtual function table.
 *
 * @param transport_proto - transport protocol type (i.e., TCP, UDP ..)
 * @param vft - virtual function table for transport proto
 * @param fib_proto - network layer protocol
 * @param output_node - output node index that session layer will hand off
 * 			buffers to, for requested fib proto
 */
void transport_register_protocol (transport_proto_t transport_proto,
				  const transport_proto_vft_t * vft,
				  fib_protocol_t fib_proto, u32 output_node);
transport_proto_t
transport_register_new_protocol (const transport_proto_vft_t * vft,
				 fib_protocol_t fib_proto, u32 output_node);
transport_proto_vft_t *transport_protocol_get_vft (transport_proto_t tp);
void transport_update_time (clib_time_type_t time_now, u8 thread_index);

int transport_alloc_local_port (u8 proto, ip46_address_t *ip,
				transport_endpoint_cfg_t *rmt);
int transport_alloc_local_endpoint (u8 proto, transport_endpoint_cfg_t *rmt,
				    ip46_address_t *lcl_addr, u16 *lcl_port);
void transport_share_local_endpoint (u8 proto, ip46_address_t * lcl_ip,
				     u16 port);
int transport_release_local_endpoint (u8 proto, ip46_address_t *lcl_ip,
				      u16 port);
u16 transport_port_alloc_max_tries ();
void transport_clear_stats ();
void transport_enable_disable (vlib_main_t * vm, u8 is_en);
void transport_init (void);

always_inline u32
transport_elog_track_index (transport_connection_t * tc)
{
#if TRANSPORT_DEBUG
  return tc->elog_track.track_index_plus_one - 1;
#else
  return ~0;
#endif
}

void transport_connection_tx_pacer_reset (transport_connection_t * tc,
					  u64 rate_bytes_per_sec,
					  u32 initial_bucket,
					  clib_us_time_t rtt);
/**
 * Initialize tx pacer for connection
 *
 * @param tc				transport connection
 * @param rate_bytes_per_second		initial byte rate
 * @param burst_bytes			initial burst size in bytes
 */
void transport_connection_tx_pacer_init (transport_connection_t * tc,
					 u64 rate_bytes_per_sec,
					 u32 initial_bucket);

/**
 * Update tx pacer pacing rate
 *
 * @param tc			transport connection
 * @param bytes_per_sec		new pacing rate
 * @param rtt			connection rtt that is used to compute
 * 				inactivity time after which pacer bucket is
 * 				reset to 1 mtu
 */
void transport_connection_tx_pacer_update (transport_connection_t * tc,
					   u64 bytes_per_sec,
					   clib_us_time_t rtt);

/**
 * Get tx pacer max burst
 *
 * @param tc		transport connection
 * @param time_now	current cpu time
 * @return		max burst for connection
 */
u32 transport_connection_tx_pacer_burst (transport_connection_t * tc);

/**
 * Get tx pacer current rate
 *
 * @param tc		transport connection
 * @return		rate for connection in bytes/s
 */
u64 transport_connection_tx_pacer_rate (transport_connection_t * tc);

/**
 * Reset tx pacer bucket
 *
 * @param tc		transport connection
 * @param bucket	value the bucket will be reset to
 */
void transport_connection_tx_pacer_reset_bucket (transport_connection_t * tc,
						 u32 bucket);

/**
 * Check if transport connection is paced
 */
always_inline u8
transport_connection_is_tx_paced (transport_connection_t * tc)
{
  return (tc->flags & TRANSPORT_CONNECTION_F_IS_TX_PACED);
}

/**
 * Clear descheduled flag and update pacer if needed
 *
 * To add session to scheduler use @ref transport_connection_reschedule
 */
always_inline void
transport_connection_clear_descheduled (transport_connection_t *tc)
{
  tc->flags &= ~TRANSPORT_CONNECTION_F_DESCHED;
  if (transport_connection_is_tx_paced (tc))
    transport_connection_tx_pacer_reset_bucket (tc, 0 /* bucket */);
}

u8 *format_transport_pacer (u8 * s, va_list * args);

/**
 * Update tx bytes for paced transport connection
 *
 * If tx pacing is enabled, this update pacer bucket to account for the
 * amount of bytes that have been sent.
 *
 * @param tc		transport connection
 * @param bytes		bytes recently sent
 */
void transport_connection_update_tx_bytes (transport_connection_t * tc,
					   u32 bytes);

void
transport_connection_tx_pacer_update_bytes (transport_connection_t * tc,
					    u32 bytes);

/**
 * Request pacer time update
 *
 * @param thread_index	thread for which time is updated
 * @param now		time now
 */
void transport_update_pacer_time (u32 thread_index, clib_time_type_t now);

#endif /* SRC_VNET_SESSION_TRANSPORT_H_ */

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