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/*
* Copyright (C) 2015 Martine Lenders <mlenders@inf.fu-berlin.de>
*
* This file is subject to the terms and conditions of the GNU Lesser
* General Public License v2.1. See the file LICENSE in the top level
* directory for more details.
*/
/**
* @{
*
* @file
*/
#include <stdbool.h>
#include <inttypes.h>
#include "mutex.h"
#include "net/gnrc/sixlowpan/ctx.h"
#include "xtimer.h"
#define ENABLE_DEBUG (0)
#include "debug.h"
static gnrc_sixlowpan_ctx_t _ctxs[GNRC_SIXLOWPAN_CTX_SIZE];
static uint32_t _ctx_inval_times[GNRC_SIXLOWPAN_CTX_SIZE];
static mutex_t _ctx_mutex = MUTEX_INIT;
static uint32_t _current_minute(void);
static void _update_lifetime(uint8_t id);
#if ENABLE_DEBUG
static char ipv6str[IPV6_ADDR_MAX_STR_LEN];
#endif
static inline bool _valid(uint8_t id)
{
_update_lifetime(id);
return (_ctxs[id].prefix_len > 0);
}
gnrc_sixlowpan_ctx_t *gnrc_sixlowpan_ctx_lookup_addr(const ipv6_addr_t *addr)
{
uint8_t best = 0;
gnrc_sixlowpan_ctx_t *res = NULL;
mutex_lock(&_ctx_mutex);
for (unsigned int id = 0; id < GNRC_SIXLOWPAN_CTX_SIZE; id++) {
if (_valid(id)) {
uint8_t match = ipv6_addr_match_prefix(&_ctxs[id].prefix, addr);
if ((_ctxs[id].prefix_len <= match) && (match > best)) {
best = match;
res = &(_ctxs[id]);
}
}
}
mutex_unlock(&_ctx_mutex);
#if ENABLE_DEBUG
if (res != NULL) {
DEBUG("6lo ctx: found context (%u, %s/%" PRIu8 ") ",
(res->flags_id & GNRC_SIXLOWPAN_CTX_FLAGS_CID_MASK),
ipv6_addr_to_str(ipv6str, &res->prefix, sizeof(ipv6str)),
res->prefix_len);
DEBUG("for address %s\n", ipv6_addr_to_str(ipv6str, addr, sizeof(ipv6str)));
}
#endif
return res;
}
gnrc_sixlowpan_ctx_t *gnrc_sixlowpan_ctx_lookup_id(uint8_t id)
{
if (id >= GNRC_SIXLOWPAN_CTX_SIZE) {
return NULL;
}
mutex_lock(&_ctx_mutex);
if (_valid(id)) {
DEBUG("6lo ctx: found context (%u, %s/%" PRIu8 ")\n", id,
ipv6_addr_to_str(ipv6str, &_ctxs[id].prefix, sizeof(ipv6str)),
_ctxs[id].prefix_len);
mutex_unlock(&_ctx_mutex);
return &(_ctxs[id]);
}
mutex_unlock(&_ctx_mutex);
return NULL;
}
gnrc_sixlowpan_ctx_t *gnrc_sixlowpan_ctx_update(uint8_t id, const ipv6_addr_t *prefix,
uint8_t prefix_len, uint16_t ltime,
bool comp)
{
if ((id >= GNRC_SIXLOWPAN_CTX_SIZE) || (prefix_len == 0)) {
return NULL;
}
mutex_lock(&_ctx_mutex);
_ctxs[id].ltime = ltime;
if (ltime == 0) {
comp = false;
}
if (prefix_len > IPV6_ADDR_BIT_LEN) {
_ctxs[id].prefix_len = IPV6_ADDR_BIT_LEN;
}
else {
_ctxs[id].prefix_len = prefix_len;
}
_ctxs[id].flags_id = (comp) ? (GNRC_SIXLOWPAN_CTX_FLAGS_COMP | id) : id;
if (!ipv6_addr_equal(&(_ctxs[id].prefix), prefix)) {
ipv6_addr_set_unspecified(&(_ctxs[id].prefix));
ipv6_addr_init_prefix(&(_ctxs[id].prefix), prefix, _ctxs[id].prefix_len);
}
DEBUG("6lo ctx: update context (%u, %s/%" PRIu8 "), lifetime: %" PRIu16 " min\n",
id, ipv6_addr_to_str(ipv6str, &_ctxs[id].prefix, sizeof(ipv6str)),
_ctxs[id].prefix_len, _ctxs[id].ltime);
_ctx_inval_times[id] = ltime + _current_minute();
mutex_unlock(&_ctx_mutex);
return &(_ctxs[id]);
}
static uint32_t _current_minute(void)
{
return xtimer_now_usec() / (US_PER_SEC * 60);
}
static void _update_lifetime(uint8_t id)
{
uint32_t now;
if (_ctxs[id].ltime == 0) {
_ctxs[id].flags_id &= ~GNRC_SIXLOWPAN_CTX_FLAGS_COMP;
return;
}
now = _current_minute();
if (now >= _ctx_inval_times[id]) {
DEBUG("6lo ctx: context %u was invalidated for compression\n", id);
_ctxs[id].ltime = 0;
_ctxs[id].flags_id &= ~GNRC_SIXLOWPAN_CTX_FLAGS_COMP;
}
else {
_ctxs[id].ltime = (uint16_t)(_ctx_inval_times[id] - now);
}
}
#ifdef TEST_SUITES
#include <string.h>
void gnrc_sixlowpan_ctx_reset(void)
{
memset(_ctxs, 0, sizeof(_ctxs));
}
#endif
/** @} */