csma.c File Reference

    A Carrier Sense Multiple Access (CSMA) MAC layer

Author

Adam Dunkels adam@.nosp@m.sics.nosp@m..se

#include "net/mac/csma.h"
#include "net/packetbuf.h"
#include "net/queuebuf.h"
#include "sys/ctimer.h"
#include "sys/contiki-clock.h"
#include "lib/random.h"
#include "net/netstack.h"
#include "lib/list.h"
#include "lib/memb.h"
#include <string.h>
#include <stdio.h>

Data Structures
struct	neighbor_queue
struct	qbuf_metadata

Macros
#define	_DEBUG_   0
#define	CSMA_MAX_BACKOFF_EXPONENT   3
#define	CSMA_MAX_MAC_TRANSMISSIONS   3
#define	CSMA_MAX_NEIGHBOR_QUEUES   4
#define	MAX_QUEUED_PACKETS   QUEUEBUF_NUM
#define	PRINTF(...)

Functions
static unsigned short	channel_check_interval (void)
static clock_time_t	default_timebase (void)
static void	free_packet (struct neighbor_queue *n, struct rdc_buf_list *p)
static void	init (void)
static void	input_packet (void)
	LIST (neighbor_list)
	MEMB (neighbor_memb, struct neighbor_queue, CSMA_MAX_NEIGHBOR_QUEUES)
	MEMB (packet_memb, struct rdc_buf_list, MAX_QUEUED_PACKETS)
	MEMB (metadata_memb, struct qbuf_metadata, MAX_QUEUED_PACKETS)
static struct neighbor_queue *	neighbor_queue_from_addr (const linkaddr_t *addr)
static int	off (int keep_radio_on)
static int	on (void)
static void	packet_sent (void *ptr, int status, int num_transmissions)
static void	send_packet (mac_callback_t sent, void *ptr)
static void	transmit_packet_list (void *ptr)

Variables
struct mac_driver	csma_driver

#define _DEBUG_   0

#define CSMA_MAX_BACKOFF_EXPONENT   3

Referenced by packet_sent().

#define CSMA_MAX_MAC_TRANSMISSIONS   3

Referenced by send_packet().

#define CSMA_MAX_NEIGHBOR_QUEUES   4

#define MAX_QUEUED_PACKETS   QUEUEBUF_NUM

#define PRINTF

(

...

)

Referenced by free_packet(), packet_sent(), send_packet(), and transmit_packet_list().

static unsigned short channel_check_interval ( void  )

static

References rdc_driver::channel_check_interval, and NETSTACK_RDC.

static clock_time_t default_timebase ( void  )

static

References rdc_driver::channel_check_interval, CLOCK_SECOND, NETSTACK_RDC, and NETSTACK_RDC_CHANNEL_CHECK_RATE.

Referenced by free_packet(), and packet_sent().

static void free_packet ( struct neighbor_queue *  n, struct rdc_buf_list *  p  )

static

References rdc_buf_list::buf, neighbor_queue::collisions, ctimer_set(), ctimer_stop(), default_timebase(), neighbor_queue::deferrals, list_head(), list_length(), list_remove(), memb_free(), NULL, PRINTF, rdc_buf_list::ptr, queuebuf_free(), neighbor_queue::transmissions, transmit_packet_list(), and neighbor_queue::transmit_timer.

Referenced by packet_sent().

static void init ( void  )

static

References memb_init().

static void input_packet ( void  )

static

References network_driver::input, and NETSTACK_NETWORK.

LIST

(

neighbor_list

)

MEMB	(	neighbor_memb	,
		struct neighbor_queue	,
		CSMA_MAX_NEIGHBOR_QUEUES
	)

MEMB	(	packet_memb	,
		struct rdc_buf_list	,
		MAX_QUEUED_PACKETS
	)

MEMB	(	metadata_memb	,
		struct qbuf_metadata	,
		MAX_QUEUED_PACKETS
	)

static struct neighbor_queue* neighbor_queue_from_addr ( const linkaddr_t *  addr )

static

References neighbor_queue::addr, linkaddr_cmp(), list_head(), list_item_next(), n, and NULL.

Referenced by send_packet().

static int off ( int  keep_radio_on )

static

References NETSTACK_RDC, and rdc_driver::off.

static int on ( void  )

static

References NETSTACK_RDC, and rdc_driver::on.

static void packet_sent ( void *  ptr, int  status, int  num_transmissions  )

static

References rdc_buf_list::buf, neighbor_queue::collisions, qbuf_metadata::cptr, CSMA_MAX_BACKOFF_EXPONENT, ctimer_set(), default_timebase(), neighbor_queue::deferrals, free_packet(), list_head(), list_item_next(), mac_call_sent_callback(), MAC_TX_AGAIN, MAC_TX_COLLISION, MAC_TX_DEFERRED, MAC_TX_NOACK, MAC_TX_OK, qbuf_metadata::max_transmissions, metadata, n, NULL, PACKETBUF_ATTR_MAC_SEQNO, PRINTF, rdc_buf_list::ptr, ptr, queuebuf_attr(), queuebuf_update_attr_from_packetbuf(), random_rand(), qbuf_metadata::sent, neighbor_queue::transmissions, transmit_packet_list(), and neighbor_queue::transmit_timer.

Referenced by transmit_packet_list().

static void send_packet ( mac_callback_t  sent, void *  ptr  )

static

References neighbor_queue::addr, addr, rdc_buf_list::buf, neighbor_queue::collisions, qbuf_metadata::cptr, CSMA_MAX_MAC_TRANSMISSIONS, ctimer_set(), neighbor_queue::deferrals, initialized, linkaddr_copy(), list_add(), list_head(), list_length(), list_push(), list_remove(), LIST_STRUCT_INIT, mac_call_sent_callback(), MAC_TX_ERR, qbuf_metadata::max_transmissions, memb_alloc(), memb_free(), metadata, n, neighbor_queue_from_addr(), NULL, packetbuf_addr(), PACKETBUF_ADDR_RECEIVER, packetbuf_attr(), PACKETBUF_ATTR_MAC_SEQNO, PACKETBUF_ATTR_MAX_MAC_TRANSMISSIONS, PACKETBUF_ATTR_PACKET_TYPE, PACKETBUF_ATTR_PACKET_TYPE_ACK, packetbuf_set_attr(), PRINTF, rdc_buf_list::ptr, ptr, queuebuf_new_from_packetbuf(), random_rand(), qbuf_metadata::sent, neighbor_queue::transmissions, transmit_packet_list(), and neighbor_queue::transmit_timer.

static void transmit_packet_list ( void *  ptr )

static

References list_head(), list_length(), n, NETSTACK_RDC, NULL, packet_sent(), PRINTF, ptr, rdc_driver::send_list, and neighbor_queue::transmissions.

Referenced by free_packet(), packet_sent(), and send_packet().

struct mac_driver csma_driver

Initial value:

= {
  "CSMA",
  init,
  send_packet,
  input_packet,
  on,
  off,
  channel_check_interval,
}