/*
 * Copyright (c) 2017 SUSE LLC.
 * 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_vnet_sctp_h
#define included_vnet_sctp_h

#include <vnet/vnet.h>
#include <vnet/ip/ip.h>
#include <vnet/sctp/sctp_timer.h>
#include <vnet/sctp/sctp_packet.h>
#include <vnet/session/transport.h>
#include <vnet/session/session.h>

/* SCTP timers */
#define foreach_sctp_timer              	\
  _(T1_INIT, "T1_INIT")           			\
  _(T1_COOKIE, "T1_COOKIE")        			\
  _(T2_SHUTDOWN, "T2_SHUTDOWN")         	\
  _(T3_RXTX, "T3_RXTX")   					\
  _(T5_SHUTDOWN_GUARD, "T5_SHUTDOWN_GUARD")

typedef enum _sctp_timers
{
#define _(sym, str) SCTP_TIMER_##sym,
  foreach_sctp_timer
#undef _
  SCTP_N_TIMERS
} sctp_timers_e;

#define SCTP_TIMER_HANDLE_INVALID ((u32) ~0)

typedef enum _sctp_error
{
#define sctp_error(n,s) SCTP_ERROR_##n,
#include <vnet/sctp/sctp_error.def>
#undef sctp_error
  SCTP_N_ERROR,
} sctp_error_t;

#define NO_FLAG 0

#define IS_T_BIT_SET(var) ((var) & (1))
#define IS_E_BIT_SET(var) ((var) & (1))
#define IS_B_BIT_SET(var) ((var) & (1<<1))
#define IS_U_BIT_SET(var) ((var) & (1<<2))

#define MAX_SCTP_CONNECTIONS 32
#define MAIN_SCTP_SUB_CONN_IDX 0

#if (VLIB_BUFFER_TRACE_TRAJECTORY)
#define sctp_trajectory_add_start(b, start)			\
{								\
    (*vlib_buffer_trace_trajectory_cb) (b, start);		\
}
#else
#define sctp_trajectory_add_start(b, start)
#endif

typedef struct _sctp_sub_connection
{
  transport_connection_t connection;	      /**< Common transport data. First! */
  void *parent;								/**< Link to the parent-super connection */
  u32 timers[SCTP_N_TIMERS];		/**< Timer handles into timer wheel */

} sctp_sub_connection_t;

typedef struct
{
  u32 a_rwnd;		/**< Maximum segment size advertised */

} sctp_options_t;

typedef struct _sctp_connection
{
  sctp_sub_connection_t sub_conn[MAX_SCTP_CONNECTIONS];	       /**< Common transport data. First! */

  u8 state;			/**< SCTP state as per sctp_state_t */
  u16 flags;		/**< Chunk flag (see sctp_chunks_common_hdr_t) */
  u32 local_tag;	/**< INIT_TAG generated locally */
  u32 remote_tag;	/**< INIT_TAG generated by the remote peer */
  u16 life_span_inc;

  /** Send sequence variables RFC4960 */
  u32 snd_una;		/**< oldest unacknowledged sequence number */
  u32 snd_una_max;	/**< newest unacknowledged sequence number + 1*/
  u32 snd_wl1;		/**< seq number used for last snd.wnd update */
  u32 snd_wl2;		/**< ack number used for last snd.wnd update */
  u32 snd_nxt;		/**< next seq number to be sent */

  /** Receive sequence variables RFC4960 */
  u32 rcv_nxt;		/**< next sequence number expected */
  u32 rcv_las;		/**< rcv_nxt at last ack sent/rcv_wnd update */
  u32 iss;		/**< initial sent sequence */
  u32 irs;		/**< initial remote sequence */

  /* RTT and RTO */
  u32 rto;		/**< Retransmission timeout */
  u32 rto_boff;		/**< Index for RTO backoff */
  u32 srtt;		/**< Smoothed RTT */
  u32 rttvar;		/**< Smoothed mean RTT difference. Approximates variance */
  u32 rtt_ts;		/**< Timestamp for tracked ACK */
  u32 rtt_seq;		/**< Sequence number for tracked ACK */

  u32 a_rwnd;			/** Constrained by medium / IP / etc. */
  u32 rcv_a_rwnd;		/**< LOCAL max seg size that includes options. To be updated by congestion algos, etc. */
  u32 snd_a_rwnd;		/**< REMOTE max seg size that includes options. To be updated if peer pushes back on window, etc.*/
  sctp_options_t rcv_opts;
  sctp_options_t snd_opts;
  u32 snd_hdr_length;	/**< BASE HEADER LENGTH for the DATA chunk when sending */

  u8 next_avail_sub_conn; /**< Represent the index of the next free slot in sub_conn */
} sctp_connection_t;

typedef void (timer_expiration_handler) (u32 index);

sctp_connection_t *sctp_connection_new (u8 thread_index);
void sctp_sub_connection_add_ip4 (u8 thread_index,
				  sctp_ipv4_addr_param_t * ipv4_addr);
void sctp_sub_connection_add_ip6 (u8 thread_index,
				  sctp_ipv6_addr_param_t * ipv6_addr);
void sctp_connection_close (sctp_connection_t * tc);
void sctp_connection_cleanup (sctp_connection_t * tc);
void sctp_connection_del (sctp_connection_t * tc);

u32 sctp_push_header (transport_connection_t * tconn, vlib_buffer_t * b);
void sctp_send_init (sctp_connection_t * tc);
void sctp_send_shutdown (sctp_connection_t * tc);
void sctp_send_shutdown_ack (sctp_connection_t * tc);
void sctp_send_shutdown_complete (sctp_connection_t * tc);
void sctp_flush_frame_to_output (vlib_main_t * vm, u8 thread_index,
				 u8 is_ip4);
void sctp_flush_frames_to_output (u8 thread_index);
void sctp_punt_unknown (vlib_main_t * vm, u8 is_ip4, u8 is_add);

format_function_t format_sctp_state;

u8 *format_sctp_connection_id (u8 * s, va_list * args);
u8 *format_sctp_connection (u8 * s, va_list * args);
u8 *format_sctp_scoreboard (u8 * s, va_list * args);
u8 *format_sctp_header (u8 * s, va_list * args);
u8 *format_sctp_tx_trace (u8 * s, va_list * args);

clib_error_t *sctp_init (vlib_main_t * vm);
void sctp_connection_timers_init (sctp_connection_t * tc);
void sctp_connection_timers_reset (sctp_connection_t * tc);
void sctp_init_snd_vars (sctp_connection_t * tc);
void sctp_connection_init_vars (sctp_connection_t * tc);

void sctp_prepare_initack_chunk (sctp_connection_t * ts, vlib_buffer_t * b,
				 ip4_address_t * ip4_addr,
				 ip6_address_t * ip6_addr);
void sctp_prepare_cookie_echo_chunk (sctp_connection_t * tc,
				     vlib_buffer_t * b,
				     sctp_state_cookie_param_t * sc);
void sctp_prepare_cookie_ack_chunk (sctp_connection_t * tc,
				    vlib_buffer_t * b);
void sctp_prepare_sack_chunk (sctp_connection_t * tc, vlib_buffer_t * b);

u16 sctp_check_outstanding_data_chunks (sctp_connection_t * tc);

#define SCTP_TICK 0.001			/**< SCTP tick period (s) */
#define STHZ (u32) (1/SCTP_TICK)		/**< SCTP tick frequency */
#define SCTP_TSTAMP_RESOLUTION SCTP_TICK	/**< Time stamp resolution */
#define SCTP_PAWS_IDLE 24 * 24 * 60 * 60 * THZ /**< 24 days */
#define SCTP_FIB_RECHECK_PERIOD	1 * THZ	/**< Recheck every 1s */
#define SCTP_MAX_OPTION_SPACE 40

#define SCTP_DUPACK_THRESHOLD 	3
#define SCTP_MAX_RX_FIFO_SIZE 	4 << 20
#define SCTP_MIN_RX_FIFO_SIZE	4 << 10
#define SCTP_IW_N_SEGMENTS 	10
#define SCTP_ALWAYS_ACK		1	/**< On/off delayed acks */
#define SCTP_USE_SACKS		1	/**< Disable only for testing */

#define IP_PROTOCOL_SCTP	132

/** SSCTP FSM state definitions as per RFC4960. */
#define foreach_sctp_fsm_state                \
  _(CLOSED, "CLOSED")                         \
  _(COOKIE_WAIT, "COOKIE_WAIT")               \
  _(COOKIE_ECHOED, "COOKIE_ECHOED")           \
  _(ESTABLISHED, "ESTABLISHED")               \
  _(SHUTDOWN_PENDING, "SHUTDOWN_PENDING")     \
  _(SHUTDOWN_SENT, "SHUTDOWN_SENT")           \
  _(SHUTDOWN_RECEIVED, "SHUTDOWN_RECEIVED")   \
  _(SHUTDOWN_ACK_SENT, "SHUTDOWN_ACK_SENT")

typedef enum _sctp_state
{
#define _(sym, str) SCTP_STATE_##sym,
  foreach_sctp_fsm_state
#undef _
  SCTP_N_STATES
} sctp_state_t;

always_inline char *
sctp_state_to_string (u8 state)
{
  switch (state)
    {
    case SCTP_STATE_CLOSED:
      return "SCTP_STATE_CLOSED";
    case SCTP_STATE_COOKIE_WAIT:
      return "SCTP_STATE_COOKIE_WAIT";
    case SCTP_STATE_COOKIE_ECHOED:
      return "SCTP_STATE_COOKIE_ECHOED";
    case SCTP_STATE_ESTABLISHED:
      return "SCTP_STATE_ESTABLISHED";
    case SCTP_STATE_SHUTDOWN_PENDING:
      return "SCTP_STATE_SHUTDOWN_PENDING";
    case SCTP_STATE_SHUTDOWN_SENT:
      return "SCTP_STATE_SHUTDOWN_SENT";
    case SCTP_STATE_SHUTDOWN_RECEIVED:
      return "SCTP_STATE_SHUTDOWN_RECEIVED";
    case SCTP_STATE_SHUTDOWN_ACK_SENT:
      return "SCTP_STATE_SHUTDOWN_ACK_SENT";
    }
  return NULL;
}

always_inline char *
sctp_chunk_to_string (u8 type)
{
  switch (type)
    {
    case DATA:
      return "DATA";
    case INIT:
      return "INIT";
    case INIT_ACK:
      return "INIT_ACK";
    case SACK:
      return "SACK";
    case HEARTBEAT:
      return "HEARTBEAT";
    case HEARTBEAT_ACK:
      return "HEARTBEAT_ACK";
    case ABORT:
      return "ABORT";
    case SHUTDOWN:
      return "SHUTDOWN";
    case SHUTDOWN_ACK:
      return "SHUTDOWN_ACK";
    case OPERATION_ERROR:
      return "OPERATION_ERROR";
    case COOKIE_ECHO:
      return "COOKIE_ECHO";
    case COOKIE_ACK:
      return "COOKIE_ACK";
    case ECNE:
      return "ECNE";
    case CWR:
      return "CWR";
    case SHUTDOWN_COMPLETE:
      return "SHUTDOWN_COMPLETE";
    }
  return NULL;
}

always_inline char *
sctp_optparam_type_to_string (u8 type)
{
  switch (type)
    {
    case SCTP_IPV4_ADDRESS_TYPE:
      return "SCTP_IPV4_ADDRESS_TYPE";
    case SCTP_IPV6_ADDRESS_TYPE:
      return "SCTP_IPV6_ADDRESS_TYPE";
    case SCTP_STATE_COOKIE_TYPE:
      return "SCTP_STATE_COOKIE_TYPE";
    case SCTP_UNRECOGNIZED_TYPE:
      return "SCTP_UNRECOGNIZED_TYPE";
    case SCTP_COOKIE_PRESERVATIVE_TYPE:
      return "SCTP_COOKIE_PRESERVATIVE_TYPE";
    case SCTP_HOSTNAME_ADDRESS_TYPE:
      return "SCTP_HOSTNAME_ADDRESS_TYPE";
    case SCTP_SUPPORTED_ADDRESS_TYPES:
      return "SCTP_SUPPORTED_ADDRESS_TYPES";
    }
  return NULL;
}

#define SCTP_TICK 0.001			/**< SCTP tick period (s) */
#define SHZ (u32) (1/SCTP_TICK)		/**< SCTP tick frequency */

/* As per RFC4960, page 83 */
#define SCTP_RTO_INIT 3 * SHZ	/* 3 seconds */
#define SCTP_RTO_MIN 1 * SHZ	/* 1 second */
#define SCTP_RTO_MAX 60 * SHZ	/* 60 seconds */
#define SCTP_RTO_BURST	4
#define SCTP_RTO_ALPHA 1/8
#define SCTP_RTO_BETA 1/4
#define SCTP_VALID_COOKIE_LIFE 60 * SHZ	/* 60 seconds */
#define SCTP_ASSOCIATION_MAX_RETRANS 10

#define SCTP_TO_TIMER_TICK       SCTP_TICK*10	/* Period for converting from SCTP_TICK */

typedef struct _sctp_lookup_dispatch
{
  u8 next, error;
} sctp_lookup_dispatch_t;

typedef struct _sctp_main
{
  /* Per-worker thread SCTP connection pools */
  sctp_connection_t **connections;

  /* Pool of listeners. */
  sctp_connection_t *listener_pool;

	  /** Dispatch table by state and flags */
  sctp_lookup_dispatch_t dispatch_table[SCTP_N_STATES][64];

  u8 log2_tstamp_clocks_per_tick;
  f64 tstamp_ticks_per_clock;
  u32 *time_now;

	  /** per-worker tx buffer free lists */
  u32 **tx_buffers;
	  /** per-worker tx frames to SCTP 4/6 output nodes */
  vlib_frame_t **tx_frames[2];
	  /** per-worker tx frames to ip 4/6 lookup nodes */
  vlib_frame_t **ip_lookup_tx_frames[2];

  /* Per worker-thread timer wheel for connections timers */
  tw_timer_wheel_16t_2w_512sl_t *timer_wheels;

  /* Pool of half-open connections on which we've sent a SYN */
  sctp_connection_t *half_open_connections;
  clib_spinlock_t half_open_lock;

  /* TODO: Congestion control algorithms registered */
  /* sctp_cc_algorithm_t *cc_algos; */

  /* Flag that indicates if stack is on or off */
  u8 is_enabled;

	  /** Number of preallocated connections */
  u32 preallocated_connections;

	  /** Transport table (preallocation) size parameters */
  u32 local_endpoints_table_memory;
  u32 local_endpoints_table_buckets;

	  /** Vectors of src addresses. Optional unless one needs > 63K active-opens */
  ip4_address_t *ip4_src_addresses;
  u32 last_v4_address_rotor;
  u32 last_v6_address_rotor;
  ip6_address_t *ip6_src_addresses;

	  /** vlib buffer size */
  u32 bytes_per_buffer;

  u8 punt_unknown4;
  u8 punt_unknown6;

} sctp_main_t;

extern sctp_main_t sctp_main;
extern vlib_node_registration_t sctp4_input_node;
extern vlib_node_registration_t sctp6_input_node;
extern vlib_node_registration_t sctp4_output_node;
extern vlib_node_registration_t sctp6_output_node;

always_inline sctp_main_t *
vnet_get_sctp_main ()
{
  return &sctp_main;
}

always_inline sctp_header_t *
sctp_buffer_hdr (vlib_buffer_t * b)
{
  ASSERT ((signed) b->current_data >= (signed) -VLIB_BUFFER_PRE_DATA_SIZE);
  return (sctp_header_t *) (b->data + b->current_data
			    + vnet_buffer (b)->sctp.hdr_offset);
}

clib_error_t *vnet_sctp_enable_disable (vlib_main_t * vm, u8 is_en);

always_inline sctp_connection_t *
sctp_half_open_connection_get (u32 conn_index)
{
  sctp_connection_t *tc = 0;
  clib_spinlock_lock_if_init (&sctp_main.half_open_lock);
  if (!pool_is_free_index (sctp_main.half_open_connections, conn_index))
    tc = pool_elt_at_index (sctp_main.half_open_connections, conn_index);
  tc->sub_conn[MAIN_SCTP_SUB_CONN_IDX].parent = tc;
  clib_spinlock_unlock_if_init (&sctp_main.half_open_lock);
  return tc;
}

/**
 * Cleanup half-open connection
 *
 */
always_inline void
sctp_half_open_connection_del (sctp_connection_t * tc)
{
  sctp_main_t *tm = vnet_get_sctp_main ();
  clib_spinlock_lock_if_init (&tm->half_open_lock);
  pool_put_index (tm->half_open_connections,
		  tc->sub_conn[MAIN_SCTP_SUB_CONN_IDX].c_c_index);
  if (CLIB_DEBUG)
    memset (tc, 0xFA, sizeof (*tc));
  clib_spinlock_unlock_if_init (&tm->half_open_lock);
}

always_inline u32
sctp_set_time_now (u32 thread_index)
{
  sctp_main.time_now[thread_index] = clib_cpu_time_now ()
    * sctp_main.tstamp_ticks_per_clock;
  return sctp_main.time_now[thread_index];
}

always_inline void
sctp_timer_set (sctp_connection_t * tc, u8 conn_idx, u8 timer_id,
		u32 interval)
{
  ASSERT (tc->sub_conn[conn_idx].connection.thread_index ==
	  vlib_get_thread_index ());
  ASSERT (tc->sub_conn[conn_idx].timers[timer_id] ==
	  SCTP_TIMER_HANDLE_INVALID);

  sctp_sub_connection_t *sub = &tc->sub_conn[conn_idx];
  tc->sub_conn[conn_idx].timers[timer_id] =
    tw_timer_start_16t_2w_512sl (&sctp_main.timer_wheels[sub->c_thread_index],
				 sub->c_c_index, timer_id, interval);
}

always_inline void
sctp_timer_reset (sctp_connection_t * tc, u8 conn_idx, u8 timer_id)
{
  ASSERT (tc->sub_conn[conn_idx].c_thread_index == vlib_get_thread_index ());
  if (tc->sub_conn[conn_idx].timers[timer_id] == SCTP_TIMER_HANDLE_INVALID)
    return;

  sctp_sub_connection_t *sub = &tc->sub_conn[conn_idx];

  tw_timer_stop_16t_2w_512sl (&sctp_main.timer_wheels[sub->c_thread_index],
			      sub->timers[timer_id]);
  sub->timers[timer_id] = SCTP_TIMER_HANDLE_INVALID;
}

always_inline void
sctp_update_time (f64 now, u32 thread_index)
{
  sctp_set_time_now (thread_index);
  tw_timer_expire_timers_16t_2w_512sl (&sctp_main.timer_wheels[thread_index],
				       now);
  sctp_flush_frames_to_output (thread_index);
}

/**
 * Try to cleanup half-open connection
 *
 * If called from a thread that doesn't own tc, the call won't have any
 * effect.
 *
 * @param tc - connection to be cleaned up
 * @return non-zero if cleanup failed.
 */
always_inline int
sctp_half_open_connection_cleanup (sctp_connection_t * tc)
{
  /* Make sure this is the owning thread */
  if (tc->sub_conn[MAIN_SCTP_SUB_CONN_IDX].c_thread_index !=
      vlib_get_thread_index ())
    return 1;
  sctp_timer_reset (tc, MAIN_SCTP_SUB_CONN_IDX, SCTP_TIMER_T1_INIT);
  sctp_half_open_connection_del (tc);
  return 0;
}

always_inline u32
sctp_header_bytes ()
{
  return sizeof (sctp_header_t);
}

always_inline sctp_connection_t *
sctp_get_connection_from_transport (transport_connection_t * tconn)
{
  ASSERT (tconn != NULL);

  sctp_sub_connection_t *sub = (sctp_sub_connection_t *) tconn;
#if SCTP_ADV_DEBUG
  if (sub == NULL)
    SCTP_ADV_DBG ("sub == NULL");
  if (sub->parent == NULL)
    SCTP_ADV_DBG ("sub->parent == NULL");
#endif
  return (sctp_connection_t *) sub->parent;
}

always_inline u32
sctp_time_now (void)
{
  return sctp_main.time_now[vlib_get_thread_index ()];
}

always_inline void
sctp_timer_update (sctp_connection_t * tc, u8 conn_idx, u8 timer_id,
		   u32 interval)
{
  ASSERT (tc->sub_conn[conn_idx].connection.thread_index ==
	  vlib_get_thread_index ());
  sctp_sub_connection_t *sub = &tc->sub_conn[conn_idx];

  if (tc->sub_conn[conn_idx].timers[timer_id] != SCTP_TIMER_HANDLE_INVALID)
    tw_timer_stop_16t_2w_512sl (&sctp_main.timer_wheels[sub->c_thread_index],
				sub->timers[timer_id]);
  tc->sub_conn[conn_idx].timers[timer_id] =
    tw_timer_start_16t_2w_512sl (&sctp_main.timer_wheels[sub->c_thread_index],
				 sub->c_c_index, timer_id, interval);
}

always_inline sctp_connection_t *
sctp_listener_get (u32 tli)
{
  return pool_elt_at_index (sctp_main.listener_pool, tli);
}

#endif

always_inline sctp_connection_t *
sctp_connection_get (u32 conn_index, u32 thread_index)
{
  if (PREDICT_FALSE
      (pool_is_free_index (sctp_main.connections[thread_index], conn_index)))
    return 0;
  return pool_elt_at_index (sctp_main.connections[thread_index], conn_index);
}

always_inline u8
sctp_pick_conn_idx_on_chunk (sctp_chunk_type chunk_type)
{
  u8 idx = MAIN_SCTP_SUB_CONN_IDX;

  switch (chunk_type)
    {
    case DATA:
    case INIT:
    case INIT_ACK:
    case SACK:
    case HEARTBEAT:
    case HEARTBEAT_ACK:
    case ABORT:
    case SHUTDOWN:
    case SHUTDOWN_ACK:
    case OPERATION_ERROR:
    case COOKIE_ECHO:
    case COOKIE_ACK:
    case ECNE:
    case CWR:
    case SHUTDOWN_COMPLETE:
      idx = MAIN_SCTP_SUB_CONN_IDX;
    }
  return idx;
}

always_inline u8
sctp_pick_conn_idx_on_state (sctp_state_t state)
{
  u8 idx = MAIN_SCTP_SUB_CONN_IDX;

  switch (state)
    {
    case SCTP_STATE_CLOSED:
    case SCTP_STATE_COOKIE_WAIT:
    case SCTP_STATE_COOKIE_ECHOED:
    case SCTP_STATE_ESTABLISHED:
    case SCTP_STATE_SHUTDOWN_PENDING:
    case SCTP_STATE_SHUTDOWN_SENT:
    case SCTP_STATE_SHUTDOWN_RECEIVED:
    case SCTP_STATE_SHUTDOWN_ACK_SENT:
      idx = MAIN_SCTP_SUB_CONN_IDX;
    default:
      idx = MAIN_SCTP_SUB_CONN_IDX;
    }
  return idx;
}

/**
 * Push SCTP header to buffer
 *
 * @param vm - vlib_main
 * @param b - buffer to write the header to
 * @param sp_net - source port net order
 * @param dp_net - destination port net order
 * @param sctp_hdr_opts_len - header and options length in bytes
 *
 * @return - pointer to start of SCTP header
 */
always_inline void *
vlib_buffer_push_sctp_net_order (vlib_buffer_t * b, u16 sp, u16 dp,
				 u8 sctp_hdr_opts_len)
{
  sctp_full_hdr_t *full_hdr;

  full_hdr = vlib_buffer_push_uninit (b, sctp_hdr_opts_len);

  full_hdr->hdr.src_port = sp;
  full_hdr->hdr.dst_port = dp;
  full_hdr->hdr.checksum = 0;
  return full_hdr;
}

/**
 * Push SCTP header to buffer
 *
 * @param b - buffer to write the header to
 * @param sp_net - source port net order
 * @param dp_net - destination port net order
 * @param sctp_hdr_opts_len - header and options length in bytes
 *
 * @return - pointer to start of SCTP header
 */
always_inline void *
vlib_buffer_push_sctp (vlib_buffer_t * b, u16 sp_net, u16 dp_net,
		       u8 sctp_hdr_opts_len)
{
  return vlib_buffer_push_sctp_net_order (b, sp_net, dp_net,
					  sctp_hdr_opts_len);
}

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