tuntap.c File Reference

TunTap Kernel stack (reverse) punt/inject path. More...

Include dependency graph for tuntap.c:

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Data Structures
struct	subif_address_t
struct	tuntap_per_thread_t
	TUNTAP per thread struct. More...
struct	tuntap_main_t
	TUNTAP node main state. More...
struct	in6_ifreq
	workaround for a known include file bug. More...

Functions
static void	tuntap_punt_frame (vlib_main_t *vm, vlib_node_runtime_t *node, vlib_frame_t *frame)
	TX the tun/tap frame. More...
static void	tuntap_nopunt_frame (vlib_main_t *vm, vlib_node_runtime_t *node, vlib_frame_t *frame)
	Free the tun/tap frame. More...
static uword	tuntap_tx (vlib_main_t *vm, vlib_node_runtime_t *node, vlib_frame_t *frame)
	tuntap_tx More...
static uword	tuntap_rx (vlib_main_t *vm, vlib_node_runtime_t *node, vlib_frame_t *frame)
	TUNTAP receive node. More...
static clib_error_t *	tuntap_read_ready (clib_file_t *uf)
	Gets called when file descriptor is ready from epoll. More...
static clib_error_t *	tuntap_exit (vlib_main_t *vm)
	Clean up the tun/tap device. More...
static clib_error_t *	tuntap_config (vlib_main_t *vm, unformat_input_t *input)
	CLI function for tun/tap config. More...
void	tuntap_ip4_add_del_interface_address (ip4_main_t *im, uword opaque, u32 sw_if_index, ip4_address_t *address, u32 address_length, u32 if_address_index, u32 is_delete)
	Add or Del IP4 address to tun/tap interface. More...
void	tuntap_ip6_add_del_interface_address (ip6_main_t *im, uword opaque, u32 sw_if_index, ip6_address_t *address, u32 address_length, u32 if_address_index, u32 is_delete)
	Add or Del tun/tap interface address. More...
	VNET_HW_INTERFACE_CLASS (tuntap_interface_class, static)
static u8 *	format_tuntap_interface_name (u8 *s, va_list *args)
	Format tun/tap interface name. More...
static uword	tuntap_intfc_tx (vlib_main_t *vm, vlib_node_runtime_t *node, vlib_frame_t *frame)
	TX packet out tun/tap. More...
	VNET_DEVICE_CLASS (tuntap_dev_class, static)
static clib_error_t *	tuntap_init (vlib_main_t *vm)
	tun/tap node init More...

Variables
static vnet_device_class_t	tuntap_dev_class
static vnet_hw_interface_class_t	tuntap_interface_class
static tuntap_main_t	tuntap_main
static vlib_node_registration_t	tuntap_tx_node
	(constructor) VLIB_REGISTER_NODE (tuntap_tx_node) More...
static char *	tuntap_rx_error_strings []
	TUNTAP_RX error strings. More...
static vlib_node_registration_t	tuntap_rx_node
	(constructor) VLIB_REGISTER_NODE (tuntap_rx_node) More...

Detailed Description

TunTap Kernel stack (reverse) punt/inject path.

This driver runs in one of two distinct modes:

• "punt/inject" mode, where we send pkts not otherwise processed by the forwarding to the Linux kernel stack, and
• "normal interface" mode, where we treat the Linux kernel stack as a peer.

By default, we select punt/inject mode.

Definition in file tuntap.c.

Function Documentation

format_tuntap_interface_name()

static u8* format_tuntap_interface_name ( u8 *  s, va_list *  args  )

static

Format tun/tap interface name.

Parameters

*s	- u8 - formatter string
*args	- va_list

Returns

*s - u8 - formatted string

Definition at line 953 of file tuntap.c.

tuntap_config()

static clib_error_t* tuntap_config ( vlib_main_t *  vm, unformat_input_t *  input  )

static

CLI function for tun/tap config.

Parameters

*vm	- vlib_main_t
*input	- unformat_input_t

Returns

error - clib_error_t

Definition at line 476 of file tuntap.c.

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tuntap_exit()

static clib_error_t* tuntap_exit ( vlib_main_t *  vm )

static

Clean up the tun/tap device.

Parameters

*vm	- vlib_main_t

Returns

error - clib_error_t

Definition at line 426 of file tuntap.c.

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tuntap_init()

static clib_error_t* tuntap_init ( vlib_main_t *  vm )

static

tun/tap node init

Parameters

*vm	- vlib_main_t

Returns

error - clib_error_t

Definition at line 1004 of file tuntap.c.

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tuntap_intfc_tx()

static uword tuntap_intfc_tx ( vlib_main_t *  vm, vlib_node_runtime_t *  node, vlib_frame_t *  frame  )

static

TX packet out tun/tap.

Parameters

*vm	- vlib_main_t
*node	- vlib_node_runtime_t
*frame	- vlib_frame_t

Returns

n_buffers - uword - Packets transmitted

Definition at line 972 of file tuntap.c.

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tuntap_ip4_add_del_interface_address()

void tuntap_ip4_add_del_interface_address	(	ip4_main_t *	im,
		uword	opaque,
		u32	sw_if_index,
		ip4_address_t *	address,
		u32	address_length,
		u32	if_address_index,
		u32	is_delete
	)

Add or Del IP4 address to tun/tap interface.

Parameters

*im	- ip4_main_t
opaque	- uword
sw_if_index	- u32
*address	- ip4_address_t
is_delete	- u32

Tuntap disabled, or using a "normal" interface.

See if we already know about this subif

Definition at line 689 of file tuntap.c.

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tuntap_ip6_add_del_interface_address()

void tuntap_ip6_add_del_interface_address	(	ip6_main_t *	im,
		uword	opaque,
		u32	sw_if_index,
		ip6_address_t *	address,
		u32	address_length,
		u32	if_address_index,
		u32	is_delete
	)

Add or Del tun/tap interface address.

Both the v6 interface address API and the way ifconfig displays subinterfaces differ from their v4 counterparts. The code given here seems to work but YMMV.

Parameters

*im	- ip6_main_t
opaque	- uword
sw_if_index	- u32
*address	- ip6_address_t
address_length	- u32
if_address_index	- u32
is_delete	- u32

Definition at line 804 of file tuntap.c.

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tuntap_nopunt_frame()

static void tuntap_nopunt_frame ( vlib_main_t *  vm, vlib_node_runtime_t *  node, vlib_frame_t *  frame  )

static

Free the tun/tap frame.

Parameters

*vm	- vlib_main_t
*node	- vlib_node_runtime_t
*frame	- vlib_frame_t

Definition at line 927 of file tuntap.c.

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tuntap_punt_frame()

static void tuntap_punt_frame ( vlib_main_t *  vm, vlib_node_runtime_t *  node, vlib_frame_t *  frame  )

static

TX the tun/tap frame.

Parameters

*vm	- vlib_main_t
*node	- vlib_node_runtime_t
*frame	- vlib_frame_t

Definition at line 911 of file tuntap.c.

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tuntap_read_ready()

static clib_error_t* tuntap_read_ready ( clib_file_t *  uf )

static

Gets called when file descriptor is ready from epoll.

Parameters

*uf	- clib_file_t

Returns

error - clib_error_t

Definition at line 410 of file tuntap.c.

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tuntap_rx()

static uword tuntap_rx ( vlib_main_t *  vm, vlib_node_runtime_t *  node, vlib_frame_t *  frame  )

static

TUNTAP receive node.

Node Identifier:

tuntap-rx

Parameters

*vm	- vlib_main_t
*node	- vlib_node_runtime_t
*frame	- vlib_frame_t

Returns

rc - uword

Make sure we have some RX buffers.

Allocate RX buffers from end of rx_buffers. Turn them into iovecs to pass to readv.

We should have enough buffers left for an MTU sized packet.

Interface counters for tuntap interface.

Definition at line 241 of file tuntap.c.

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tuntap_tx()

static uword tuntap_tx ( vlib_main_t *  vm, vlib_node_runtime_t *  node, vlib_frame_t *  frame  )

static

tuntap_tx

Node Identifier:

tuntap-tx

Output node, writes the buffers comprising the incoming frame to the tun/tap device, aka hands them to the Linux kernel stack.

Parameters

*vm	- vlib_main_t
*node	- vlib_node_runtime_t
*frame	- vlib_frame_t

Returns

rc - uword

VLIB buffer chain -> Unix iovec(s).

The normal interface path flattens the buffer chain

Definition at line 147 of file tuntap.c.

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VNET_DEVICE_CLASS()

VNET_DEVICE_CLASS	(	tuntap_dev_class	,
		static
	)

VNET_HW_INTERFACE_CLASS()

VNET_HW_INTERFACE_CLASS	(	tuntap_interface_class	,
		static
	)

Variable Documentation

tuntap_dev_class

vnet_device_class_t tuntap_dev_class

static

Definition at line 54 of file tuntap.c.

tuntap_interface_class

vnet_hw_interface_class_t tuntap_interface_class

static

Definition at line 55 of file tuntap.c.

tuntap_main

tuntap_main_t tuntap_main

static

Initial value:

= {
  .tun_name = "vnet",
 
  
  .mtu_bytes = 4096 + 256,
}

Definition at line 125 of file tuntap.c.

tuntap_rx_error_strings

char* tuntap_rx_error_strings[]

static

Initial value:

= {
  "unknown packet type",
}

TUNTAP_RX error strings.

Definition at line 384 of file tuntap.c.

tuntap_rx_node

vlib_node_registration_t tuntap_rx_node

static

Initial value:

= {
  .function = tuntap_rx,
  .flags = VLIB_NODE_FLAG_TRACE_SUPPORTED,
  .name = "tuntap-rx",
  .sibling_of = "device-input",
  .type = VLIB_NODE_TYPE_INPUT,
  .state = VLIB_NODE_STATE_INTERRUPT,
  .vector_size = 4,
  .n_errors = 1,
  .error_strings = tuntap_rx_error_strings,
}

(constructor) VLIB_REGISTER_NODE (tuntap_rx_node)

Definition at line 389 of file tuntap.c.

tuntap_tx_node

vlib_node_registration_t tuntap_tx_node

static

Initial value:

= {
  .function = tuntap_tx,
  .name = "tuntap-tx",
  .type = VLIB_NODE_TYPE_INTERNAL,
  .vector_size = 4,
}

(constructor) VLIB_REGISTER_NODE (tuntap_tx_node)

Definition at line 221 of file tuntap.c.