tcp_output.c File Reference

Include dependency graph for tcp_output.c:

Go to the source code of this file.

Data Structures
struct	tcp_tx_trace_t

Macros
#define	foreach_tcp4_output_next   _ (DROP, "error-drop") \
#define	foreach_tcp6_output_next   _ (DROP, "error-drop") \
#define	tcp_error(n, s)   s,
#define	tcp_get_free_buffer_index(tm, bidx)
#define	tcp_return_buffer(tm)
#define	foreach_tcp4_reset_next
#define	foreach_tcp6_reset_next

Typedefs
typedef enum _tcp_output_nect	tcp_output_next_t
typedef enum _tcp_reset_next	tcp_reset_next_t

Functions
u8 *	format_tcp_tx_trace (u8 *s, va_list *args)
static u8	tcp_window_compute_scale (u32 available_space)
static u32	tcp_initial_wnd_unscaled (tcp_connection_t *tc)
	TCP's IW as recommended by RFC6928. More...
u32	tcp_initial_window_to_advertise (tcp_connection_t *tc)
	Compute initial window and scale factor. More...
u32	tcp_window_to_advertise (tcp_connection_t *tc, tcp_state_t state)
	Compute and return window to advertise, scaled as per RFC1323. More...
void	tcp_update_rcv_wnd (tcp_connection_t *tc)
u32	tcp_options_write (u8 *data, tcp_options_t *opts)
	Write TCP options to segment. More...
static int	tcp_make_syn_options (tcp_options_t *opts, u8 wnd_scale)
static int	tcp_make_synack_options (tcp_connection_t *tc, tcp_options_t *opts)
static int	tcp_make_established_options (tcp_connection_t *tc, tcp_options_t *opts)
static int	tcp_make_options (tcp_connection_t *tc, tcp_options_t *opts, tcp_state_t state)
void	tcp_update_rcv_mss (tcp_connection_t *tc)
	Update max segment size we're able to process. More...
void	tcp_update_snd_mss (tcp_connection_t *tc)
	Update snd_mss to reflect the effective segment size that we can send by taking into account all TCP options, including SACKs. More...
void	tcp_init_mss (tcp_connection_t *tc)
static void	tcp_reuse_buffer (vlib_main_t *vm, vlib_buffer_t *b)
void	tcp_make_ack_i (tcp_connection_t *tc, vlib_buffer_t *b, tcp_state_t state, u8 flags)
	Prepare ACK. More...
void	tcp_make_ack (tcp_connection_t *tc, vlib_buffer_t *b)
	Convert buffer to ACK. More...
void	tcp_make_fin (tcp_connection_t *tc, vlib_buffer_t *b)
	Convert buffer to FIN-ACK. More...
void	tcp_make_synack (tcp_connection_t *tc, vlib_buffer_t *b)
	Convert buffer to SYN-ACK. More...
static void	tcp_enqueue_to_ip_lookup (vlib_main_t *vm, vlib_buffer_t *b, u32 bi, u8 is_ip4)
int	tcp_make_reset_in_place (vlib_main_t *vm, vlib_buffer_t *b0, tcp_state_t state, u8 thread_index, u8 is_ip4)
void	tcp_send_reset (vlib_buffer_t *pkt, u8 is_ip4)
	Send reset without reusing existing buffer. More...
void	tcp_push_ip_hdr (tcp_main_t *tm, tcp_connection_t *tc, vlib_buffer_t *b)
void	tcp_send_syn (tcp_connection_t *tc)
	Send SYN. More...
static void	tcp_enqueue_to_output (vlib_main_t *vm, vlib_buffer_t *b, u32 bi, u8 is_ip4)
void	tcp_send_fin (tcp_connection_t *tc)
	Send FIN. More...
static u8	tcp_make_state_flags (tcp_state_t next_state)
static void	tcp_push_hdr_i (tcp_connection_t *tc, vlib_buffer_t *b, tcp_state_t next_state, u8 compute_opts)
	Push TCP header and update connection variables. More...
void	tcp_send_ack (tcp_connection_t *tc)
void	tcp_timer_delack_handler (u32 index)
u32	tcp_prepare_retransmit_segment (tcp_connection_t *tc, vlib_buffer_t *b, u32 offset, u32 max_bytes)
	Build a retransmit segment. More...
static void	tcp_rtx_timeout_cc (tcp_connection_t *tc)
	Reset congestion control, switch cwnd to loss window and try again. More...
static void	tcp_timer_retransmit_handler_i (u32 index, u8 is_syn)
void	tcp_timer_retransmit_handler (u32 index)
void	tcp_timer_retransmit_syn_handler (u32 index)
void	tcp_timer_persist_handler (u32 index)
	Got 0 snd_wnd from peer, try to do something about it. More...
void	tcp_retransmit_first_unacked (tcp_connection_t *tc)
	Retransmit first unacked segment. More...
void	tcp_fast_retransmit_sack (tcp_connection_t *tc)
	Do fast retransmit with SACKs. More...
void	tcp_fast_retransmit_no_sack (tcp_connection_t *tc)
	Fast retransmit without SACK info. More...
void	tcp_fast_retransmit (tcp_connection_t *tc)
	Do fast retransmit. More...
static u32	tcp_session_has_ooo_data (tcp_connection_t *tc)
static uword	tcp46_output_inline (vlib_main_t *vm, vlib_node_runtime_t *node, vlib_frame_t *from_frame, int is_ip4)
static uword	tcp4_output (vlib_main_t *vm, vlib_node_runtime_t *node, vlib_frame_t *from_frame)
static uword	tcp6_output (vlib_main_t *vm, vlib_node_runtime_t *node, vlib_frame_t *from_frame)
	VLIB_NODE_FUNCTION_MULTIARCH (tcp4_output_node, tcp4_output)
	VLIB_NODE_FUNCTION_MULTIARCH (tcp6_output_node, tcp6_output)
u32	tcp_push_header (transport_connection_t *tconn, vlib_buffer_t *b)
static uword	tcp46_send_reset_inline (vlib_main_t *vm, vlib_node_runtime_t *node, vlib_frame_t *from_frame, u8 is_ip4)
static uword	tcp4_send_reset (vlib_main_t *vm, vlib_node_runtime_t *node, vlib_frame_t *from_frame)
static uword	tcp6_send_reset (vlib_main_t *vm, vlib_node_runtime_t *node, vlib_frame_t *from_frame)
	VLIB_NODE_FUNCTION_MULTIARCH (tcp4_reset_node, tcp4_send_reset)
	VLIB_NODE_FUNCTION_MULTIARCH (tcp6_reset_node, tcp6_send_reset)

Variables
vlib_node_registration_t	tcp4_output_node
	(constructor) VLIB_REGISTER_NODE (tcp4_output_node) More...
vlib_node_registration_t	tcp6_output_node
	(constructor) VLIB_REGISTER_NODE (tcp6_output_node) More...
static char *	tcp_error_strings []
u16	dummy_mtu = 1460
vlib_node_registration_t	tcp4_reset_node
	(constructor) VLIB_REGISTER_NODE (tcp4_reset_node) More...
vlib_node_registration_t	tcp6_reset_node
	(constructor) VLIB_REGISTER_NODE (tcp6_reset_node) More...

Macro Definition Documentation

#define foreach_tcp4_output_next   _ (DROP, "error-drop") \

Definition at line 28 of file tcp_output.c.

#define foreach_tcp4_reset_next

Value:

_(DROP, "error-drop")                 \
  _(IP_LOOKUP, "ip4-lookup")

Definition at line 1659 of file tcp_output.c.

#define foreach_tcp6_output_next   _ (DROP, "error-drop") \

Definition at line 31 of file tcp_output.c.

#define foreach_tcp6_reset_next

Value:

_(DROP, "error-drop")                 \
  _(IP_LOOKUP, "ip6-lookup")

Definition at line 1663 of file tcp_output.c.

#define tcp_error	(		n,
			s
	)		s,

#define tcp_get_free_buffer_index	(		tm,
			bidx
	)

Value:

do {                                                                    \
  u32 *my_tx_buffers, n_free_buffers;                                   \
  u32 thread_index = vlib_get_thread_index();                                   \
  my_tx_buffers = tm->tx_buffers[thread_index];                            \
  if (PREDICT_FALSE(vec_len (my_tx_buffers) == 0))                      \
    {                                                                   \
      n_free_buffers = 32;      /* TODO config or macro */              \
      vec_validate (my_tx_buffers, n_free_buffers - 1);                 \
      _vec_len(my_tx_buffers) = vlib_buffer_alloc_from_free_list (      \
          tm->vlib_main, my_tx_buffers, n_free_buffers,                 \
          VLIB_BUFFER_DEFAULT_FREE_LIST_INDEX);                         \
      tm->tx_buffers[thread_index] = my_tx_buffers;                        \
    }                                                                   \
  /* buffer shortage */                                                 \
  if (PREDICT_FALSE (vec_len (my_tx_buffers) == 0))                     \
    return;                                                             \
  *bidx = my_tx_buffers[_vec_len (my_tx_buffers)-1];                    \
  _vec_len (my_tx_buffers) -= 1;                                        \
} while (0)

Definition at line 427 of file tcp_output.c.

#define tcp_return_buffer

(

tm

)

Value:

do {                                                                    \
  u32 *my_tx_buffers;                                                   \
  u32 thread_index = vlib_get_thread_index();                                   \
  my_tx_buffers = tm->tx_buffers[thread_index];                                 \
  _vec_len (my_tx_buffers) +=1;                                         \
} while (0)

Definition at line 448 of file tcp_output.c.

Typedef Documentation

typedef enum _tcp_output_nect tcp_output_next_t

typedef enum _tcp_reset_next tcp_reset_next_t

Function Documentation

u8* format_tcp_tx_trace	(	u8 *	s,
		va_list *	args
	)

Definition at line 49 of file tcp_output.c.

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static uword tcp46_output_inline ( vlib_main_t *  vm, vlib_node_runtime_t *  node, vlib_frame_t *  from_frame, int  is_ip4  )

inlinestatic

Definition at line 1426 of file tcp_output.c.

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static uword tcp46_send_reset_inline ( vlib_main_t *  vm, vlib_node_runtime_t *  node, vlib_frame_t *  from_frame, u8  is_ip4  )

static

Definition at line 1668 of file tcp_output.c.

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static uword tcp4_output ( vlib_main_t *  vm, vlib_node_runtime_t *  node, vlib_frame_t *  from_frame  )

static

Definition at line 1580 of file tcp_output.c.

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static uword tcp4_send_reset ( vlib_main_t *  vm, vlib_node_runtime_t *  node, vlib_frame_t *  from_frame  )

static

Definition at line 1737 of file tcp_output.c.

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static uword tcp6_output ( vlib_main_t *  vm, vlib_node_runtime_t *  node, vlib_frame_t *  from_frame  )

static

Definition at line 1587 of file tcp_output.c.

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static uword tcp6_send_reset ( vlib_main_t *  vm, vlib_node_runtime_t *  node, vlib_frame_t *  from_frame  )

static

Definition at line 1744 of file tcp_output.c.

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static void tcp_enqueue_to_ip_lookup ( vlib_main_t *  vm, vlib_buffer_t *  b, u32  bi, u8  is_ip4  )

inlinestatic

Definition at line 579 of file tcp_output.c.

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static void tcp_enqueue_to_output ( vlib_main_t *  vm, vlib_buffer_t *  b, u32  bi, u8  is_ip4  )

inlinestatic

Definition at line 843 of file tcp_output.c.

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void tcp_fast_retransmit

(

tcp_connection_t *

tc

)

Do fast retransmit.

Definition at line 1408 of file tcp_output.c.

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void tcp_fast_retransmit_no_sack

(

tcp_connection_t *

tc

)

Fast retransmit without SACK info.

Definition at line 1365 of file tcp_output.c.

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void tcp_fast_retransmit_sack

(

tcp_connection_t *

tc

)

Do fast retransmit with SACKs.

Definition at line 1291 of file tcp_output.c.

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void tcp_init_mss

(

tcp_connection_t *

tc

)

Definition at line 403 of file tcp_output.c.

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u32 tcp_initial_window_to_advertise

(

tcp_connection_t *

tc

)

Compute initial window and scale factor.

As per RFC1323, window field in SYN and SYN-ACK segments is never scaled.

Definition at line 88 of file tcp_output.c.

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static u32 tcp_initial_wnd_unscaled ( tcp_connection_t *  tc )

inlinestatic

TCP's IW as recommended by RFC6928.

Definition at line 78 of file tcp_output.c.

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void tcp_make_ack	(	tcp_connection_t *	tc,
		vlib_buffer_t *	b
	)

Convert buffer to ACK.

Definition at line 503 of file tcp_output.c.

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void tcp_make_ack_i	(	tcp_connection_t *	tc,
		vlib_buffer_t *	b,
		tcp_state_t	state,
		u8	flags
	)

Prepare ACK.

Definition at line 478 of file tcp_output.c.

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static int tcp_make_established_options ( tcp_connection_t *  tc, tcp_options_t *  opts  )

inlinestatic

Definition at line 323 of file tcp_output.c.

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void tcp_make_fin	(	tcp_connection_t *	tc,
		vlib_buffer_t *	b
	)

Convert buffer to FIN-ACK.

Definition at line 518 of file tcp_output.c.

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static int tcp_make_options ( tcp_connection_t *  tc, tcp_options_t *  opts, tcp_state_t  state  )

inlinestatic

Definition at line 354 of file tcp_output.c.

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int tcp_make_reset_in_place	(	vlib_main_t *	vm,
		vlib_buffer_t *	b0,
		tcp_state_t	state,
		u8	thread_index,
		u8	is_ip4
	)

Definition at line 603 of file tcp_output.c.

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static u8 tcp_make_state_flags ( tcp_state_t  next_state )

inlinestatic

Definition at line 887 of file tcp_output.c.

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static int tcp_make_syn_options ( tcp_options_t *  opts, u8  wnd_scale  )

inlinestatic

Definition at line 259 of file tcp_output.c.

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void tcp_make_synack	(	tcp_connection_t *	tc,
		vlib_buffer_t *	b
	)

Convert buffer to SYN-ACK.

Definition at line 538 of file tcp_output.c.

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static int tcp_make_synack_options ( tcp_connection_t *  tc, tcp_options_t *  opts  )

inlinestatic

Definition at line 288 of file tcp_output.c.

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u32 tcp_options_write	(	u8 *	data,
		tcp_options_t *	opts
	)

Write TCP options to segment.

Definition at line 176 of file tcp_output.c.

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u32 tcp_prepare_retransmit_segment	(	tcp_connection_t *	tc,
		vlib_buffer_t *	b,
		u32	offset,
		u32	max_bytes
	)

Build a retransmit segment.

Returns

the number of bytes in the segment or 0 if there's nothing to retransmit

Definition at line 989 of file tcp_output.c.

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static void tcp_push_hdr_i ( tcp_connection_t *  tc, vlib_buffer_t *  b, tcp_state_t  next_state, u8  compute_opts  )

static

Push TCP header and update connection variables.

Definition at line 910 of file tcp_output.c.

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u32 tcp_push_header	(	transport_connection_t *	tconn,
		vlib_buffer_t *	b
	)

Definition at line 1637 of file tcp_output.c.

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void tcp_push_ip_hdr	(	tcp_main_t *	tm,
		tcp_connection_t *	tc,
		vlib_buffer_t *	b
	)

Definition at line 757 of file tcp_output.c.

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void tcp_retransmit_first_unacked

(

tcp_connection_t *

tc

)

Retransmit first unacked segment.

Definition at line 1258 of file tcp_output.c.

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static void tcp_reuse_buffer ( vlib_main_t *  vm, vlib_buffer_t *  b  )

inlinestatic

Definition at line 457 of file tcp_output.c.

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static void tcp_rtx_timeout_cc ( tcp_connection_t *  tc )

static

Reset congestion control, switch cwnd to loss window and try again.

Definition at line 1039 of file tcp_output.c.

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void tcp_send_ack

(

tcp_connection_t *

tc

)

Definition at line 954 of file tcp_output.c.

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void tcp_send_fin

(

tcp_connection_t *

tc

)

Send FIN.

Definition at line 866 of file tcp_output.c.

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void tcp_send_reset	(	vlib_buffer_t *	pkt,
		u8	is_ip4
	)

Send reset without reusing existing buffer.

Definition at line 684 of file tcp_output.c.

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void tcp_send_syn

(

tcp_connection_t *

tc

)

Send SYN.

Builds a SYN packet for a half-open connection and sends it to ipx_lookup. The packet is not forwarded through tcpx_output to avoid doing lookups in the half_open pool.

Definition at line 789 of file tcp_output.c.

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static u32 tcp_session_has_ooo_data ( tcp_connection_t *  tc )

inlinestatic

Definition at line 1418 of file tcp_output.c.

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void tcp_timer_delack_handler

(

u32

index

)

Definition at line 973 of file tcp_output.c.

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void tcp_timer_persist_handler

(

u32

index

)

Got 0 snd_wnd from peer, try to do something about it.

Definition at line 1195 of file tcp_output.c.

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void tcp_timer_retransmit_handler

(

u32

index

)

Definition at line 1179 of file tcp_output.c.

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static void tcp_timer_retransmit_handler_i ( u32  index, u8  is_syn  )

static

Definition at line 1057 of file tcp_output.c.

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void tcp_timer_retransmit_syn_handler

(

u32

index

)

Definition at line 1185 of file tcp_output.c.

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void tcp_update_rcv_mss

(

tcp_connection_t *

tc

)

Update max segment size we're able to process.

The value is constrained by our interface's MTU and IP options. It is also what we advertise to our peer.

Definition at line 379 of file tcp_output.c.

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void tcp_update_rcv_wnd

(

tcp_connection_t *

tc

)

Definition at line 127 of file tcp_output.c.

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void tcp_update_snd_mss

(

tcp_connection_t *

tc

)

Update snd_mss to reflect the effective segment size that we can send by taking into account all TCP options, including SACKs.

Definition at line 390 of file tcp_output.c.

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static u8 tcp_window_compute_scale ( u32  available_space )

static

Definition at line 65 of file tcp_output.c.

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u32 tcp_window_to_advertise	(	tcp_connection_t *	tc,
		tcp_state_t	state
	)

Compute and return window to advertise, scaled as per RFC1323.

Definition at line 107 of file tcp_output.c.

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VLIB_NODE_FUNCTION_MULTIARCH	(	tcp4_output_node	,
		tcp4_output
	)

VLIB_NODE_FUNCTION_MULTIARCH	(	tcp6_output_node	,
		tcp6_output
	)

VLIB_NODE_FUNCTION_MULTIARCH	(	tcp4_reset_node	,
		tcp4_send_reset
	)

VLIB_NODE_FUNCTION_MULTIARCH	(	tcp6_reset_node	,
		tcp6_send_reset
	)

Variable Documentation

u16 dummy_mtu = 1460

Definition at line 46 of file tcp_output.c.

vlib_node_registration_t tcp4_output_node

Initial value:

=
{
  .function = tcp4_output,.name = "tcp4-output",
    
    .vector_size = sizeof (u32),
    .n_errors = TCP_N_ERROR,
    .error_strings = tcp_error_strings,
    .n_next_nodes = TCP_OUTPUT_N_NEXT,
    .next_nodes = {
#define _(s,n) 
    foreach_tcp4_output_next

    },
    .format_buffer = format_tcp_header,
    .format_trace = format_tcp_tx_trace,
}

(constructor) VLIB_REGISTER_NODE (tcp4_output_node)

Definition at line 19 of file tcp_output.c.

vlib_node_registration_t tcp4_reset_node

Initial value:

= {
  .function = tcp4_send_reset,
  .name = "tcp4-reset",
  .vector_size = sizeof (u32),
  .n_errors = TCP_N_ERROR,
  .error_strings = tcp_error_strings,
  .n_next_nodes = TCP_RESET_N_NEXT,
  .next_nodes = {
#define _(s,n) 
    foreach_tcp4_reset_next

  },
  .format_trace = format_tcp_tx_trace,
}

(constructor) VLIB_REGISTER_NODE (tcp4_reset_node)

Definition at line 1751 of file tcp_output.c.

vlib_node_registration_t tcp6_output_node

Initial value:

=
{
  .function = tcp6_output,
  .name = "tcp6-output",
    
  .vector_size = sizeof (u32),
  .n_errors = TCP_N_ERROR,
  .error_strings = tcp_error_strings,
  .n_next_nodes = TCP_OUTPUT_N_NEXT,
  .next_nodes = {
#define _(s,n) 
    foreach_tcp6_output_next

  },
  .format_buffer = format_tcp_header,
  .format_trace = format_tcp_tx_trace,
}

(constructor) VLIB_REGISTER_NODE (tcp6_output_node)

Definition at line 20 of file tcp_output.c.

vlib_node_registration_t tcp6_reset_node

Initial value:

= {
  .function = tcp6_send_reset,
  .name = "tcp6-reset",
  .vector_size = sizeof (u32),
  .n_errors = TCP_N_ERROR,
  .error_strings = tcp_error_strings,
  .n_next_nodes = TCP_RESET_N_NEXT,
  .next_nodes = {
#define _(s,n) 
    foreach_tcp6_reset_next

  },
  .format_trace = format_tcp_tx_trace,
}

(constructor) VLIB_REGISTER_NODE (tcp6_reset_node)

Definition at line 1770 of file tcp_output.c.

char* tcp_error_strings[]

static

Initial value:

= {
#define tcp_error(n,s) 


}

Definition at line 34 of file tcp_output.c.