669 lines
16 KiB
C
669 lines
16 KiB
C
/*
|
|
* Copyright (c) 2005, Swedish Institute of Computer Science
|
|
* All rights reserved.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions
|
|
* are met:
|
|
* 1. Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer.
|
|
* 2. Redistributions in binary form must reproduce the above copyright
|
|
* notice, this list of conditions and the following disclaimer in the
|
|
* documentation and/or other materials provided with the distribution.
|
|
* 3. Neither the name of the Institute nor the names of its contributors
|
|
* may be used to endorse or promote products derived from this software
|
|
* without specific prior written permission.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
|
|
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
* ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
|
|
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
* SUCH DAMAGE.
|
|
*
|
|
* This file is part of the Contiki operating system.
|
|
*
|
|
* @(#)$Id: cc2420.c,v 1.21 2007/07/30 14:54:49 bg- Exp $
|
|
*/
|
|
/*
|
|
* This code is almost device independent and should be easy to port.
|
|
*/
|
|
|
|
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
#include <string.h>
|
|
|
|
#if defined(__AVR__)
|
|
#include <avr/io.h>
|
|
#elif defined(__MSP430__)
|
|
#include <io.h>
|
|
#endif
|
|
|
|
#include "contiki.h"
|
|
|
|
#include "net/uip.h"
|
|
#include "net/uip-fw.h"
|
|
#define BUF ((struct uip_tcpip_hdr *)&uip_buf[UIP_LLH_LEN])
|
|
|
|
#include "dev/leds.h"
|
|
|
|
#include "dev/spi.h"
|
|
#include "dev/cc2420.h"
|
|
#include "dev/cc2420_const.h"
|
|
|
|
#define NDEBUG
|
|
#include "lib/assert.h"
|
|
|
|
#ifdef NDEBUG
|
|
#define PRINTF(...) do {} while (0)
|
|
#else
|
|
#define PRINTF(...) printf(__VA_ARGS__)
|
|
#endif
|
|
|
|
PROCESS(cc2420_process, "CC2420 driver");
|
|
PROCESS(cc2420_retransmit_process, "CC2420 retransmit process");
|
|
|
|
int cc2420_resend(void); /* Not yet exported. */
|
|
|
|
static void neigbour_update(u16_t mac, int retransmissions);
|
|
|
|
signed char cc2420_last_rssi;
|
|
u8_t cc2420_last_correlation;
|
|
u8_t cc2420_is_input;
|
|
|
|
static u8_t receive_on;
|
|
|
|
volatile u8_t cc2420_ack_received; /* Naive ACK management. */
|
|
static u8_t last_used_seq;
|
|
static u16_t last_dst;
|
|
|
|
/* Radio stuff in network byte order. */
|
|
static u16_t pan_id;
|
|
|
|
unsigned
|
|
cc2420_getreg(enum cc2420_register regname)
|
|
{
|
|
unsigned reg;
|
|
int s = splhigh();
|
|
FASTSPI_GETREG(regname, reg);
|
|
splx(s);
|
|
return reg;
|
|
}
|
|
|
|
void
|
|
cc2420_setreg(enum cc2420_register regname, unsigned value)
|
|
{
|
|
int s = splhigh();
|
|
FASTSPI_SETREG(regname, value);
|
|
splx(s);
|
|
}
|
|
|
|
void
|
|
cc2420_strobe(enum cc2420_register regname)
|
|
{
|
|
int s = splhigh();
|
|
FASTSPI_STROBE(regname);
|
|
splx(s);
|
|
}
|
|
|
|
unsigned
|
|
cc2420_status(void)
|
|
{
|
|
u8_t status;
|
|
int s = splhigh();
|
|
FASTSPI_UPD_STATUS(status);
|
|
splx(s);
|
|
return status;
|
|
}
|
|
|
|
#define AUTOACK (1 << 4)
|
|
#define RXFIFO_PROTECTION (1 << 9)
|
|
#define CORR_THR(n) (((n) & 0x1f) << 6)
|
|
#define FIFOP_THR(n) ((n) & 0x7f)
|
|
#define RXBPF_LOCUR (1 << 13);
|
|
|
|
void
|
|
cc2420_init(void)
|
|
{
|
|
u16_t reg;
|
|
{
|
|
int s = splhigh();
|
|
__cc2420_arch_init(); /* Initalize ports and SPI. */
|
|
DISABLE_FIFOP_INT();
|
|
FIFOP_INT_INIT();
|
|
splx(s);
|
|
}
|
|
|
|
/* Turn on voltage regulator and reset. */
|
|
SET_VREG_ACTIVE();
|
|
//clock_delay(250); OK
|
|
SET_RESET_ACTIVE();
|
|
clock_delay(127);
|
|
SET_RESET_INACTIVE();
|
|
//clock_delay(125); OK
|
|
|
|
|
|
/* Turn on the crystal oscillator. */
|
|
cc2420_strobe(CC2420_SXOSCON);
|
|
|
|
/* Turn on automatic packet acknowledgment. */
|
|
reg = cc2420_getreg(CC2420_MDMCTRL0);
|
|
reg |= AUTOACK;
|
|
cc2420_setreg(CC2420_MDMCTRL0, reg);
|
|
|
|
/* Change default values as recomended in the data sheet, */
|
|
/* correlation threshold = 20, RX bandpass filter = 1.3uA. */
|
|
cc2420_setreg(CC2420_MDMCTRL1, CORR_THR(20));
|
|
reg = cc2420_getreg(CC2420_RXCTRL1);
|
|
reg |= RXBPF_LOCUR;
|
|
cc2420_setreg(CC2420_RXCTRL1, reg);
|
|
|
|
/* Set the FIFOP threshold to maximum. */
|
|
cc2420_setreg(CC2420_IOCFG0, FIFOP_THR(127));
|
|
|
|
/* Turn off "Security enable" (page 32). */
|
|
reg = cc2420_getreg(CC2420_SECCTRL0);
|
|
reg &= ~RXFIFO_PROTECTION;
|
|
cc2420_setreg(CC2420_SECCTRL0, reg);
|
|
|
|
cc2420_set_chan_pan_addr(11, 0xffff, 0x0000, NULL);
|
|
}
|
|
|
|
int
|
|
cc2420_send_data_ack(u16_t mac)
|
|
{
|
|
struct hdr_802_15 h;
|
|
|
|
PRINTF("send_data_ack to %u.%u\n", mac & 0xff, mac >> 8);
|
|
|
|
h.len = MAC_HDR_LEN + 2; /* Including footer[2]. */
|
|
h.fc0 = FC0_TYPE_DATA | FC0_INTRA_PAN;
|
|
h.fc1 = FC1_DST_16 | FC1_SRC_16;
|
|
|
|
h.src = uip_hostaddr.u16[1];
|
|
h.dst = mac;
|
|
|
|
return cc2420_send(&h, 10, NULL, 0);
|
|
}
|
|
|
|
int
|
|
cc2420_send(struct hdr_802_15 *hdr, u8_t hdr_len,
|
|
const u8_t *payload, u8_t payload_len)
|
|
{
|
|
u8_t spiStatusByte;
|
|
int s;
|
|
|
|
/* struct hdr_802_15::len shall *not* be counted, thus the -1.
|
|
* 2 == sizeof(footer).
|
|
*/
|
|
if (((hdr_len - 1) + payload_len + 2) > MAX_PACKET_LEN)
|
|
return -1;
|
|
|
|
/* This code uses the CC2420 CCA (Clear Channel Assessment) to
|
|
* implement Carrier Sense Multiple Access with Collision Avoidance
|
|
* (CSMA-CA) and requires the receiver to be enabled and ready.
|
|
*/
|
|
if (!receive_on)
|
|
return -2;
|
|
|
|
/* Wait for previous transmission to finish and RSSI. */
|
|
do {
|
|
spiStatusByte = cc2420_status();
|
|
if (!(spiStatusByte & BV(CC2420_RSSI_VALID))) /* RSSI needed by CCA */
|
|
continue;
|
|
} while (spiStatusByte & BV(CC2420_TX_ACTIVE));
|
|
|
|
hdr->dst_pan = pan_id; /* Not at fixed position! xxx/bg */
|
|
last_dst = hdr->dst; /* Not dst either. */
|
|
last_used_seq++;
|
|
hdr->seq = last_used_seq;
|
|
cc2420_ack_received = 0;
|
|
|
|
/* Write packet to TX FIFO, appending FCS if AUTOCRC is enabled. */
|
|
cc2420_strobe(CC2420_SFLUSHTX); /* Cancel send that never started. */
|
|
s = splhigh();
|
|
FASTSPI_WRITE_FIFO(hdr, hdr_len);
|
|
FASTSPI_WRITE_FIFO(payload, payload_len);
|
|
splx(s);
|
|
|
|
/* Send stuff from FIFO now! */
|
|
process_post_synch(&cc2420_retransmit_process, PROCESS_EVENT_MSG, NULL);
|
|
|
|
return UIP_FW_OK;
|
|
}
|
|
|
|
/*
|
|
* Request packet to be sent using CSMA-CA. Requires that RSSI is
|
|
* valid.
|
|
*
|
|
* Return UIP_FW_DROPPED on failure.
|
|
*/
|
|
int
|
|
cc2420_resend(void)
|
|
{
|
|
unsigned i;
|
|
|
|
if (FIFOP_IS_1 && !FIFO_IS_1) {
|
|
process_poll(&cc2420_process);
|
|
PRINTF("rxfifo overflow!\n");
|
|
}
|
|
|
|
/* The TX FIFO can only hold one packet! Make sure to not overrun
|
|
* FIFO by waiting for transmission to start here and synchronizing
|
|
* with the CC2420_TX_ACTIVE check in cc2420_send.
|
|
*
|
|
* Note that we may have to wait up to 320 us (20 symbols) before
|
|
* transmission starts.
|
|
*/
|
|
#ifdef TMOTE_SKY
|
|
#define LOOP_20_SYMBOLS 100 /* 326us (msp430 @ 2.4576MHz) */
|
|
#elif __AVR__
|
|
#define LOOP_20_SYMBOLS 500 /* XXX */
|
|
#endif
|
|
if (CCA_IS_1) {
|
|
cc2420_strobe(CC2420_STXONCCA);
|
|
for (i = LOOP_20_SYMBOLS; i > 0; i--)
|
|
if (SFD_IS_1) {
|
|
if (cc2420_status() & BV(CC2420_TX_ACTIVE))
|
|
return UIP_FW_OK; /* Transmission has started. */
|
|
else
|
|
break; /* We must be receiving. */
|
|
}
|
|
}
|
|
|
|
return UIP_FW_DROPPED; /* Transmission never started! */
|
|
}
|
|
|
|
void
|
|
cc2420_off(void)
|
|
{
|
|
u8_t spiStatusByte;
|
|
|
|
if (receive_on == 0)
|
|
return;
|
|
receive_on = 0;
|
|
/* Wait for transmission to end before turning radio off. */
|
|
do {
|
|
spiStatusByte = cc2420_status();
|
|
} while (spiStatusByte & BV(CC2420_TX_ACTIVE));
|
|
|
|
cc2420_strobe(CC2420_SRFOFF);
|
|
DISABLE_FIFOP_INT();
|
|
}
|
|
|
|
void
|
|
cc2420_on(void)
|
|
{
|
|
if (receive_on)
|
|
return;
|
|
receive_on = 1;
|
|
|
|
cc2420_strobe(CC2420_SRXON);
|
|
cc2420_strobe(CC2420_SFLUSHRX);
|
|
ENABLE_FIFOP_INT();
|
|
}
|
|
|
|
void
|
|
cc2420_set_chan_pan_addr(unsigned channel, /* 11 - 26 */
|
|
unsigned pan,
|
|
unsigned addr,
|
|
const u8_t *ieee_addr)
|
|
{
|
|
/*
|
|
* Subtract the base channel (11), multiply by 5, which is the
|
|
* channel spacing. 357 is 2405-2048 and 0x4000 is LOCK_THR = 1.
|
|
*/
|
|
u8_t spiStatusByte;
|
|
u16_t f = channel;
|
|
int s;
|
|
|
|
f = 5*(f - 11) + 357 + 0x4000;
|
|
/*
|
|
* Writing RAM requires crystal oscillator to be stable.
|
|
*/
|
|
do {
|
|
spiStatusByte = cc2420_status();
|
|
} while (!(spiStatusByte & (BV(CC2420_XOSC16M_STABLE))));
|
|
|
|
pan_id = pan;
|
|
cc2420_setreg(CC2420_FSCTRL, f);
|
|
s = splhigh();
|
|
FASTSPI_WRITE_RAM_LE(&pan, CC2420RAM_PANID, 2, f);
|
|
FASTSPI_WRITE_RAM_LE(&addr, CC2420RAM_SHORTADDR, 2, f);
|
|
if (ieee_addr != NULL)
|
|
FASTSPI_WRITE_RAM_LE(ieee_addr, CC2420RAM_IEEEADDR, 8, f);
|
|
splx(s);
|
|
}
|
|
|
|
static volatile u8_t rx_fifo_remaining_bytes;
|
|
static struct hdr_802_15 h;
|
|
|
|
/*
|
|
* Interrupt either leaves frame intact in FIFO or reads *only* the
|
|
* MAC header and sets rx_fifo_remaining_bytes.
|
|
*
|
|
* In order to quickly empty the FIFO ack processing is done at
|
|
* interrupt priority rather than poll priority.
|
|
*/
|
|
int
|
|
__cc2420_intr(void)
|
|
{
|
|
u8_t length;
|
|
const u8_t *const ack_footer = (u8_t *)&h.dst_pan;
|
|
|
|
CLEAR_FIFOP_INT();
|
|
|
|
if (spi_busy || rx_fifo_remaining_bytes > 0) {
|
|
/* SPI bus hardware is currently used elsewhere (UART0 or I2C bus)
|
|
* or we already have a packet in the works and will have to defer
|
|
* interrupt processing of this packet in a fake interrupt.
|
|
*/
|
|
process_poll(&cc2420_process);
|
|
return 1;
|
|
}
|
|
|
|
FASTSPI_READ_FIFO_BYTE(length);
|
|
if (length > MAX_PACKET_LEN) {
|
|
/* Oops, we must be out of sync. */
|
|
FASTSPI_STROBE(CC2420_SFLUSHRX);
|
|
FASTSPI_STROBE(CC2420_SFLUSHRX);
|
|
return 0;
|
|
}
|
|
|
|
h.len = length;
|
|
|
|
if (length < ACK_PACKET_LEN) {
|
|
FASTSPI_READ_FIFO_GARBAGE(length); /* Rubbish */
|
|
return 0;
|
|
}
|
|
|
|
FASTSPI_READ_FIFO_NO_WAIT(&h.fc0, 5); /* fc0, fc1, seq, dst_pan */
|
|
|
|
/* Is this an ACK packet? */
|
|
if (length == ACK_PACKET_LEN && (h.fc0 & FC0_TYPE_MASK) == FC0_TYPE_ACK) {
|
|
if (ack_footer[1] & FOOTER1_CRC_OK) {
|
|
if (h.seq == last_used_seq) { /* Matching ACK number? */
|
|
cc2420_ack_received = 1;
|
|
process_poll(&cc2420_retransmit_process);
|
|
#if 0
|
|
cc2420_last_rssi = ack_footer[0];
|
|
cc2420_last_correlation = ack_footer[1] & FOOTER1_CORRELATION;
|
|
#endif
|
|
}
|
|
}
|
|
return 1;
|
|
}
|
|
|
|
if (length < (MAC_HDR_LEN + 2)) {
|
|
FASTSPI_READ_FIFO_GARBAGE(length - 5);
|
|
return 0;
|
|
}
|
|
|
|
FASTSPI_READ_FIFO_NO_WAIT(&h.dst, 4); /* dst and src */
|
|
|
|
/* The payload and footer is now left in the RX FIFO and will be
|
|
* picked up asynchronously at poll priority in the cc2420_process
|
|
* below.
|
|
*/
|
|
rx_fifo_remaining_bytes = length - MAC_HDR_LEN;
|
|
process_poll(&cc2420_process);
|
|
return 1;
|
|
}
|
|
|
|
PROCESS_THREAD(cc2420_process, ev, data)
|
|
{
|
|
PROCESS_BEGIN();
|
|
|
|
process_start(&cc2420_retransmit_process, NULL);
|
|
|
|
while (1) {
|
|
unsigned len;
|
|
int s;
|
|
|
|
PROCESS_YIELD();
|
|
|
|
len = rx_fifo_remaining_bytes;
|
|
if (len > 0) {
|
|
/* Read payload and two bytes of footer */
|
|
if ((len - 2) > (UIP_BUFSIZE - UIP_LLH_LEN) || len < 2) {
|
|
PRINTF("cc2420_process too big len=%d\n", len);
|
|
s = splhigh();
|
|
FASTSPI_READ_FIFO_GARBAGE(len);
|
|
rx_fifo_remaining_bytes = 0; /* RX FIFO emptied! */
|
|
splx(s);
|
|
len = 0;
|
|
} else {
|
|
u8_t footer[2];
|
|
uip_len = 0;
|
|
s = splhigh();
|
|
if (len > 2)
|
|
FASTSPI_READ_FIFO_NO_WAIT(&uip_buf[UIP_LLH_LEN], len - 2);
|
|
FASTSPI_READ_FIFO_NO_WAIT(footer, 2);
|
|
rx_fifo_remaining_bytes = 0; /* RX FIFO emptied! */
|
|
splx(s);
|
|
if (footer[1] & FOOTER1_CRC_OK) {
|
|
cc2420_last_rssi = footer[0];
|
|
cc2420_last_correlation = footer[1] & FOOTER1_CORRELATION;
|
|
if ((h.fc0 & FC0_TYPE_MASK) == FC0_TYPE_DATA)
|
|
uip_len = len - 2;
|
|
}
|
|
}
|
|
}
|
|
|
|
if (len == 2)
|
|
PRINTF("recv data_ack\n");
|
|
|
|
/* Clean up in case of FIFO overflow! This happens for every full
|
|
* length frame and is signaled by FIFOP = 1 and FIFO = 0.
|
|
*/
|
|
if (FIFOP_IS_1 && !FIFO_IS_1) {
|
|
cc2420_strobe(CC2420_SFLUSHRX);
|
|
cc2420_strobe(CC2420_SFLUSHRX);
|
|
}
|
|
|
|
if (FIFOP_IS_1) {
|
|
s = splhigh();
|
|
__cc2420_intr(); /* Fake interrupt! */
|
|
splx(s);
|
|
}
|
|
|
|
if (len == 2) { /* A DATA ACK packet. */
|
|
if (last_dst == h.src)
|
|
cc2420_ack_received = 1;
|
|
neigbour_update(h.src, 0);
|
|
} else if (len > 2 && uip_len > 0
|
|
&& uip_len == (((u16_t)(BUF->len[0]) << 8) + BUF->len[1])) {
|
|
/*
|
|
* If we are the unique receiver send DATA ACK.
|
|
*/
|
|
if (h.dst == 0xffff
|
|
&& uip_ipaddr_cmp(&BUF->destipaddr, &uip_hostaddr))
|
|
cc2420_send_data_ack(h.src);
|
|
leds_toggle(LEDS_GREEN);
|
|
cc2420_is_input = 1;
|
|
tcpip_input();
|
|
cc2420_is_input = 0;
|
|
leds_toggle(LEDS_GREEN);
|
|
}
|
|
}
|
|
|
|
PROCESS_END();
|
|
}
|
|
|
|
unsigned neigbour_find(u16_t mac);
|
|
|
|
/* Must be atleast 2 ticks and larger than 4ms. */
|
|
#define RETRANSMIT_TIMEOUT 2 /* 31.25ms @ 64Hz */
|
|
#define MAX_RETRANSMISSIONS 3
|
|
|
|
PROCESS_THREAD(cc2420_retransmit_process, ev, data)
|
|
{
|
|
static char n;
|
|
static struct etimer etimer;
|
|
|
|
switch (ev) {
|
|
default:
|
|
case PROCESS_EVENT_INIT:
|
|
return PT_WAITING;
|
|
|
|
case PROCESS_EVENT_EXIT:
|
|
return PT_ENDED;
|
|
|
|
case PROCESS_EVENT_POLL: /* Cancel future retransmissions. */
|
|
etimer_stop(&etimer);
|
|
neigbour_update(last_dst, n);
|
|
return PT_WAITING;
|
|
|
|
case PROCESS_EVENT_MSG: /* Send new packet. */
|
|
n = -1;
|
|
|
|
/* FALLTHROUGH */
|
|
case PROCESS_EVENT_TIMER:
|
|
if (last_dst == 0xffff) {
|
|
n++;
|
|
clock_delay(1 + (rand() & (2048 - 1)));
|
|
if (cc2420_resend() == UIP_FW_OK) {
|
|
PRINTF("REBCAST %d\n", n);
|
|
return PT_WAITING; /* Final transmission attempt. */
|
|
}
|
|
} else {
|
|
if (cc2420_resend() == UIP_FW_OK) {
|
|
n++;
|
|
PRINTF("RETRANS %d to %d.%d\n", n, last_dst & 0xff, last_dst >> 8);
|
|
}
|
|
if (n == MAX_RETRANSMISSIONS) {
|
|
neigbour_update(last_dst, n);
|
|
return PT_WAITING; /* Final transmission attempt. */
|
|
}
|
|
}
|
|
/*
|
|
* Schedule retransmission.
|
|
*/
|
|
etimer_set(&etimer, RETRANSMIT_TIMEOUT);
|
|
return PT_WAITING;
|
|
}
|
|
/* NOTREACHED */
|
|
}
|
|
|
|
/*
|
|
* Retransmissions are negexp(alfa=0.5) weighted and stored as 4-bit
|
|
* fixnums with 2 binals (binary decimals).
|
|
*/
|
|
#define SCALE_RETRANS 4
|
|
#define SCALE_RETRANS_THRESHOLD (3*4)
|
|
#define MAX_SCALE_RETRANS 15
|
|
|
|
/*
|
|
* Expiration timestamps are 4-bits wide, in units of 2 seconds, and
|
|
* relative to cc2420_check_remote::toff.
|
|
*/
|
|
#define SCALE_DIV_EXPIRE 2
|
|
#define MAX_EXPIRE 15 /* 30 seconds */
|
|
#define AGE_INTERVAL 5 /* 10 seconds */
|
|
|
|
struct cc2420_neigbour neigbours[NNEIGBOURS];
|
|
|
|
/*
|
|
* Double hash into 3 different positions using a constand step. If we
|
|
* don't find a match, return a pointer to the oldest entry and use
|
|
* this position for insertion.
|
|
*/
|
|
static struct cc2420_neigbour *
|
|
lookup(unsigned mac)
|
|
{
|
|
unsigned h = (mac + (mac>>8)) % NNEIGBOURS;
|
|
#define next(h) (h += step, (h >= NNEIGBOURS) ? (h - NNEIGBOURS) : h)
|
|
|
|
if (neigbours[h].mac == mac) /* FOUND1 */
|
|
return &neigbours[h];
|
|
else {
|
|
unsigned minexp = h;
|
|
const unsigned step = ((mac>>9)&0x3) + 1;
|
|
|
|
h = next(h);
|
|
if (neigbours[h].mac == mac) /* FOUND2 */
|
|
return &neigbours[h];
|
|
else {
|
|
if (neigbours[h].expire < neigbours[minexp].expire) minexp = h;
|
|
h = next(h);
|
|
if (neigbours[h].mac == mac) /* FOUND3 */
|
|
return &neigbours[h];
|
|
else {
|
|
if (neigbours[h].expire < neigbours[minexp].expire) minexp = h;
|
|
return &neigbours[minexp];
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
static void
|
|
neigbour_update(u16_t mac, int nretrans)
|
|
{
|
|
struct cc2420_neigbour *t;
|
|
|
|
/* Always scale nretrans by constant factor. */
|
|
if (nretrans == MAX_RETRANSMISSIONS)
|
|
nretrans = MAX_SCALE_RETRANS;
|
|
else
|
|
nretrans *= SCALE_RETRANS; /* xxx/bg overflow! */
|
|
|
|
t = lookup(mac);
|
|
if (t->mac != mac) {
|
|
t->mac = mac;
|
|
t->nretrans = nretrans;
|
|
} else {
|
|
if ((t->nretrans + nretrans)/2 > MAX_SCALE_RETRANS)
|
|
t->nretrans = MAX_SCALE_RETRANS;
|
|
else
|
|
t->nretrans = (t->nretrans + nretrans)/2;
|
|
}
|
|
t->expire = MAX_EXPIRE;
|
|
return;
|
|
}
|
|
|
|
void
|
|
cc2420_recv_ok(uip_ipaddr_t *from)
|
|
{
|
|
neigbour_update(from->u16[1], 0);
|
|
}
|
|
|
|
/*
|
|
* +1: remote
|
|
* 0: local
|
|
* -1: unknown
|
|
*/
|
|
int
|
|
cc2420_check_remote(u16_t mac)
|
|
{
|
|
struct cc2420_neigbour *t;
|
|
|
|
/*
|
|
* Age neigbour table every 5*SCALE_DIV_EXPIRE=10 seconds.
|
|
*/
|
|
static clock_time_t toff;
|
|
unsigned now = ((clock_time() - toff)/CLOCK_SECOND)/SCALE_DIV_EXPIRE;
|
|
if (now >= AGE_INTERVAL) {
|
|
unsigned i;
|
|
|
|
for (i = 0; i < NNEIGBOURS; i++)
|
|
if (neigbours[i].expire >= now)
|
|
neigbours[i].expire -= now;
|
|
else
|
|
neigbours[i].mac = 0xffff; /* expired! */
|
|
toff = clock_time();
|
|
}
|
|
|
|
t = lookup(mac);
|
|
if (t->mac != mac)
|
|
return REMOTE_MAYBE; /* unknown */
|
|
else if (t->nretrans >= SCALE_RETRANS_THRESHOLD)
|
|
return REMOTE_YES; /* remote */
|
|
else
|
|
return REMOTE_NO; /* local */
|
|
}
|