blob: 032061a871b803cfb91469954539cfb00c818aae [file] [log] [blame]
/*
* Copyright (c) 2017 Intel Corporation
*
* SPDX-License-Identifier: Apache-2.0
*/
#include <zephyr/kernel.h>
#include <errno.h>
#include <zephyr/sys/util.h>
#include <zephyr/net/buf.h>
#include <zephyr/bluetooth/bluetooth.h>
#include <zephyr/bluetooth/conn.h>
#include <zephyr/bluetooth/mesh.h>
#define BT_DBG_ENABLED IS_ENABLED(CONFIG_BT_MESH_DEBUG_BEACON)
#define LOG_MODULE_NAME bt_mesh_beacon
#include "common/log.h"
#include "adv.h"
#include "mesh.h"
#include "net.h"
#include "host/ecc.h"
#include "prov.h"
#include "crypto.h"
#include "beacon.h"
#include "foundation.h"
#define PROVISIONED_INTERVAL K_SECONDS(10)
#define BEACON_TYPE_UNPROVISIONED 0x00
#define BEACON_TYPE_SECURE 0x01
/* 3 transmissions, 20ms interval */
#define UNPROV_XMIT BT_MESH_TRANSMIT(2, 20)
/* 1 transmission, 20ms interval */
#define PROV_XMIT BT_MESH_TRANSMIT(0, 20)
static struct k_work_delayable beacon_timer;
static bool beacon_cache_match(struct bt_mesh_subnet *sub, void *beacon_data)
{
return !memcmp(sub->beacon_cache, beacon_data, 21);
}
static void cache_add(uint8_t data[21], struct bt_mesh_subnet *sub)
{
memcpy(sub->beacon_cache, data, 21);
}
void bt_mesh_beacon_cache_clear(struct bt_mesh_subnet *sub)
{
(void)memset(sub->beacon_cache, 0, 21);
}
static void beacon_complete(int err, void *user_data)
{
struct bt_mesh_subnet *sub = user_data;
BT_DBG("err %d", err);
sub->beacon_sent = k_uptime_get_32();
}
void bt_mesh_beacon_create(struct bt_mesh_subnet *sub,
struct net_buf_simple *buf)
{
uint8_t flags = bt_mesh_net_flags(sub);
struct bt_mesh_subnet_keys *keys;
net_buf_simple_add_u8(buf, BEACON_TYPE_SECURE);
keys = &sub->keys[SUBNET_KEY_TX_IDX(sub)];
net_buf_simple_add_u8(buf, flags);
/* Network ID */
net_buf_simple_add_mem(buf, keys->net_id, 8);
/* IV Index */
net_buf_simple_add_be32(buf, bt_mesh.iv_index);
net_buf_simple_add_mem(buf, sub->auth, 8);
BT_DBG("net_idx 0x%04x flags 0x%02x NetID %s", sub->net_idx,
flags, bt_hex(keys->net_id, 8));
BT_DBG("IV Index 0x%08x Auth %s", bt_mesh.iv_index,
bt_hex(sub->auth, 8));
}
/* If the interval has passed or is within 5 seconds from now send a beacon */
#define BEACON_THRESHOLD(sub) \
((10 * ((sub)->beacons_last + 1)) * MSEC_PER_SEC - (5 * MSEC_PER_SEC))
static bool secure_beacon_send(struct bt_mesh_subnet *sub, void *cb_data)
{
static const struct bt_mesh_send_cb send_cb = {
.end = beacon_complete,
};
uint32_t now = k_uptime_get_32();
struct net_buf *buf;
uint32_t time_diff;
uint32_t time_since_last_recv;
BT_DBG("");
time_diff = now - sub->beacon_sent;
time_since_last_recv = now - sub->beacon_recv;
if (time_diff < (600 * MSEC_PER_SEC) &&
(time_diff < BEACON_THRESHOLD(sub) ||
time_since_last_recv < (10 * MSEC_PER_SEC))) {
return false;
}
buf = bt_mesh_adv_create(BT_MESH_ADV_BEACON, BT_MESH_LOCAL_ADV,
PROV_XMIT, K_NO_WAIT);
if (!buf) {
BT_ERR("Unable to allocate beacon buffer");
return true; /* Bail out */
}
bt_mesh_beacon_create(sub, &buf->b);
bt_mesh_adv_send(buf, &send_cb, sub);
net_buf_unref(buf);
return false;
}
static int unprovisioned_beacon_send(void)
{
const struct bt_mesh_prov *prov;
uint8_t uri_hash[16] = { 0 };
struct net_buf *buf;
uint16_t oob_info;
BT_DBG("");
buf = bt_mesh_adv_create(BT_MESH_ADV_BEACON, BT_MESH_LOCAL_ADV,
UNPROV_XMIT, K_NO_WAIT);
if (!buf) {
BT_ERR("Unable to allocate beacon buffer");
return -ENOBUFS;
}
prov = bt_mesh_prov_get();
net_buf_add_u8(buf, BEACON_TYPE_UNPROVISIONED);
net_buf_add_mem(buf, prov->uuid, 16);
if (prov->uri && bt_mesh_s1(prov->uri, uri_hash) == 0) {
oob_info = prov->oob_info | BT_MESH_PROV_OOB_URI;
} else {
oob_info = prov->oob_info;
}
net_buf_add_be16(buf, oob_info);
net_buf_add_mem(buf, uri_hash, 4);
bt_mesh_adv_send(buf, NULL, NULL);
net_buf_unref(buf);
if (prov->uri) {
size_t len;
buf = bt_mesh_adv_create(BT_MESH_ADV_URI, BT_MESH_LOCAL_ADV,
UNPROV_XMIT, K_NO_WAIT);
if (!buf) {
BT_ERR("Unable to allocate URI buffer");
return -ENOBUFS;
}
len = strlen(prov->uri);
if (net_buf_tailroom(buf) < len) {
BT_WARN("Too long URI to fit advertising data");
} else {
net_buf_add_mem(buf, prov->uri, len);
bt_mesh_adv_send(buf, NULL, NULL);
}
net_buf_unref(buf);
}
return 0;
}
static void unprovisioned_beacon_recv(struct net_buf_simple *buf)
{
const struct bt_mesh_prov *prov;
uint8_t *uuid;
uint16_t oob_info;
uint32_t uri_hash_val;
uint32_t *uri_hash = NULL;
prov = bt_mesh_prov_get();
if (!prov->unprovisioned_beacon) {
return;
}
if (buf->len != 18 && buf->len != 22) {
BT_ERR("Invalid unprovisioned beacon length (%u)", buf->len);
return;
}
uuid = net_buf_simple_pull_mem(buf, 16);
oob_info = net_buf_simple_pull_be16(buf);
if (buf->len == 4) {
uri_hash_val = net_buf_simple_pull_be32(buf);
uri_hash = &uri_hash_val;
}
BT_DBG("uuid %s", bt_hex(uuid, 16));
prov->unprovisioned_beacon(uuid,
(bt_mesh_prov_oob_info_t)oob_info,
uri_hash);
}
static void sub_update_beacon_observation(struct bt_mesh_subnet *sub)
{
sub->beacons_last = sub->beacons_cur;
sub->beacons_cur = 0U;
}
static void update_beacon_observation(void)
{
static bool first_half;
/* Observation period is 20 seconds, whereas the beacon timer
* runs every 10 seconds. We process what's happened during the
* window only after the second half.
*/
first_half = !first_half;
if (first_half) {
return;
}
bt_mesh_subnet_foreach(sub_update_beacon_observation);
}
static void beacon_send(struct k_work *work)
{
BT_DBG("");
if (bt_mesh_is_provisioned()) {
if (!bt_mesh_beacon_enabled() &&
!atomic_test_bit(bt_mesh.flags, BT_MESH_IVU_INITIATOR)) {
return;
}
update_beacon_observation();
(void)bt_mesh_subnet_find(secure_beacon_send, NULL);
k_work_schedule(&beacon_timer, PROVISIONED_INTERVAL);
return;
}
if (IS_ENABLED(CONFIG_BT_MESH_PB_ADV)) {
/* Don't send anything if we have an active provisioning link */
if (!bt_mesh_prov_active()) {
unprovisioned_beacon_send();
}
k_work_schedule(&beacon_timer, K_SECONDS(CONFIG_BT_MESH_UNPROV_BEACON_INT));
}
}
struct beacon_params {
const uint8_t *net_id;
const uint8_t *auth;
uint32_t iv_index;
uint8_t flags;
bool new_key;
};
static bool auth_match(struct bt_mesh_subnet_keys *keys,
const struct beacon_params *params)
{
uint8_t net_auth[8];
if (memcmp(params->net_id, keys->net_id, 8)) {
return false;
}
bt_mesh_beacon_auth(keys->beacon, params->flags, keys->net_id,
params->iv_index, net_auth);
if (memcmp(params->auth, net_auth, 8)) {
BT_WARN("Authentication Value %s != %s",
bt_hex(params->auth, 8), bt_hex(net_auth, 8));
return false;
}
return true;
}
static bool subnet_by_id(struct bt_mesh_subnet *sub, void *cb_data)
{
struct beacon_params *params = cb_data;
for (int i = 0; i < ARRAY_SIZE(sub->keys); i++) {
if (sub->keys[i].valid && auth_match(&sub->keys[i], params)) {
params->new_key = (i > 0);
return true;
}
}
return false;
}
static void secure_beacon_recv(struct net_buf_simple *buf)
{
struct beacon_params params;
struct bt_mesh_subnet *sub;
uint8_t *data;
if (buf->len < 21) {
BT_ERR("Too short secure beacon (len %u)", buf->len);
return;
}
sub = bt_mesh_subnet_find(beacon_cache_match, buf->data);
if (sub) {
/* We've seen this beacon before - just update the stats */
goto update_stats;
}
/* So we can add to the cache if auth matches */
data = buf->data;
params.flags = net_buf_simple_pull_u8(buf);
params.net_id = net_buf_simple_pull_mem(buf, 8);
params.iv_index = net_buf_simple_pull_be32(buf);
params.auth = buf->data;
BT_DBG("flags 0x%02x id %s iv_index 0x%08x",
params.flags, bt_hex(params.net_id, 8), params.iv_index);
sub = bt_mesh_subnet_find(subnet_by_id, &params);
if (!sub) {
BT_DBG("No subnet that matched beacon");
return;
}
if (sub->kr_phase == BT_MESH_KR_PHASE_2 && !params.new_key) {
BT_WARN("Ignoring Phase 2 KR Update secured using old key");
return;
}
cache_add(data, sub);
bt_mesh_kr_update(sub, BT_MESH_KEY_REFRESH(params.flags),
params.new_key);
/* If we have NetKey0 accept initiation only from it */
if (bt_mesh_subnet_get(BT_MESH_KEY_PRIMARY) &&
sub->net_idx != BT_MESH_KEY_PRIMARY) {
BT_WARN("Ignoring secure beacon on non-primary subnet");
goto update_stats;
}
BT_DBG("net_idx 0x%04x iv_index 0x%08x, current iv_index 0x%08x",
sub->net_idx, params.iv_index, bt_mesh.iv_index);
if (atomic_test_bit(bt_mesh.flags, BT_MESH_IVU_INITIATOR) &&
(atomic_test_bit(bt_mesh.flags, BT_MESH_IVU_IN_PROGRESS) ==
BT_MESH_IV_UPDATE(params.flags))) {
bt_mesh_beacon_ivu_initiator(false);
}
bt_mesh_net_iv_update(params.iv_index, BT_MESH_IV_UPDATE(params.flags));
update_stats:
if (bt_mesh_beacon_enabled() &&
sub->beacons_cur < 0xff) {
sub->beacons_cur++;
sub->beacon_recv = k_uptime_get_32();
}
}
void bt_mesh_beacon_recv(struct net_buf_simple *buf)
{
uint8_t type;
BT_DBG("%u bytes: %s", buf->len, bt_hex(buf->data, buf->len));
if (buf->len < 1) {
BT_ERR("Too short beacon");
return;
}
type = net_buf_simple_pull_u8(buf);
switch (type) {
case BEACON_TYPE_UNPROVISIONED:
if (IS_ENABLED(CONFIG_BT_MESH_PB_ADV)) {
unprovisioned_beacon_recv(buf);
}
break;
case BEACON_TYPE_SECURE:
secure_beacon_recv(buf);
break;
default:
BT_WARN("Unknown beacon type 0x%02x", type);
break;
}
}
void bt_mesh_beacon_update(struct bt_mesh_subnet *sub)
{
uint8_t flags = bt_mesh_net_flags(sub);
struct bt_mesh_subnet_keys *keys;
int err;
keys = &sub->keys[SUBNET_KEY_TX_IDX(sub)];
BT_DBG("NetIndex 0x%03x Using %s key", sub->net_idx,
SUBNET_KEY_TX_IDX(sub) ? "new" : "current");
BT_DBG("flags 0x%02x, IVI 0x%08x", flags, bt_mesh.iv_index);
err = bt_mesh_beacon_auth(keys->beacon, flags, keys->net_id,
bt_mesh.iv_index, sub->auth);
if (err) {
BT_ERR("Failed updating net beacon for 0x%03x", sub->net_idx);
}
}
static void subnet_evt(struct bt_mesh_subnet *sub, enum bt_mesh_key_evt evt)
{
if (evt != BT_MESH_KEY_DELETED) {
bt_mesh_beacon_update(sub);
}
}
BT_MESH_SUBNET_CB_DEFINE(beacon) = {
.evt_handler = subnet_evt,
};
void bt_mesh_beacon_init(void)
{
k_work_init_delayable(&beacon_timer, beacon_send);
}
void bt_mesh_beacon_ivu_initiator(bool enable)
{
atomic_set_bit_to(bt_mesh.flags, BT_MESH_IVU_INITIATOR, enable);
/* Fire the beacon handler straight away if it's not already pending -
* in which case we'll fire according to the ongoing periodic sending.
* If beacons are disabled, the handler will exit early.
*
* An alternative solution would be to check whether beacons are enabled
* here, and cancel if not. As the cancel operation may fail, we would
* still have to implement an early exit mechanism, so we might as well
* just use this every time.
*/
k_work_schedule(&beacon_timer, K_NO_WAIT);
}
static void subnet_beacon_enable(struct bt_mesh_subnet *sub)
{
sub->beacons_last = 0U;
sub->beacons_cur = 0U;
bt_mesh_beacon_update(sub);
}
void bt_mesh_beacon_enable(void)
{
if (bt_mesh_is_provisioned()) {
bt_mesh_subnet_foreach(subnet_beacon_enable);
}
k_work_reschedule(&beacon_timer, K_NO_WAIT);
}
void bt_mesh_beacon_disable(void)
{
if (!atomic_test_bit(bt_mesh.flags, BT_MESH_IVU_INITIATOR)) {
/* If this fails, we'll do an early exit in the work handler. */
(void)k_work_cancel_delayable(&beacon_timer);
}
}