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components/esp_wifi/wifi_apps/roaming_app/src/roaming_app.c
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/*
* SPDX-FileCopyrightText: 2023-2024 Espressif Systems (Shanghai) CO LTD
*
* SPDX-License-Identifier: Apache-2.0
*/
#include <string.h>
#include <inttypes.h>
#include <stdlib.h>
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "freertos/event_groups.h"
#include "esp_wifi.h"
#include "esp_wnm.h"
#include "esp_rrm.h"
#include "esp_mbo.h"
#include "esp_event.h"
#include "esp_log.h"
#include "esp_mac.h"
#include "nvs_flash.h"
#include <sys/time.h>
#include "regex.h"
#include <stdio.h>
#include "esp_roaming.h"
#include "utils/common.h"
#include "esp_wifi_driver.h"
#include "utils/eloop.h"
#include "rom/ets_sys.h"
#include "common/ieee802_11_defs.h"
static struct roaming_app g_roaming_app;
typedef void (* scan_done_cb_t)(void *arg, ETS_STATUS status);
extern int esp_wifi_promiscuous_scan_start(wifi_scan_config_t *config, scan_done_cb_t cb);
static void *scan_results_lock = NULL;
#define ROAM_SCAN_RESULTS_LOCK() os_mutex_lock(scan_results_lock)
#define ROAM_SCAN_RESULTS_UNLOCK() os_mutex_unlock(scan_results_lock)
#if PERIODIC_RRM_MONITORING
static void *neighbor_list_lock = NULL;
#define ROAM_NEIGHBOR_LIST_LOCK() os_mutex_lock(neighbor_list_lock)
#define ROAM_NEIGHBOR_LIST_UNLOCK() os_mutex_unlock(neighbor_list_lock)
#endif /*PERIODIC_RRM_MONITORING*/
static int wifi_post_roam_event(struct cand_bss *bss);
static void determine_best_ap(int8_t rssi_threshold);
static const char *ROAMING_TAG = "ROAM";
static inline long time_diff_sec(struct timeval *a, struct timeval *b)
{
return (a->tv_sec - b->tv_sec);
}
void roaming_app_disable_reconnect(void)
{
ESP_LOGD(ROAMING_TAG, "Switching off reconnect due to application trigerred disconnect");
g_roaming_app.allow_reconnect = false;
}
void roaming_app_enable_reconnect(void)
{
ESP_LOGD(ROAMING_TAG, "Switching on reconnect due to application trigerred reconnect");
g_roaming_app.allow_reconnect = true;
}
static void roaming_app_get_ap_info(wifi_ap_record_t *ap_info)
{
esp_wifi_sta_get_ap_info(ap_info);
#if LOW_RSSI_ROAMING_ENABLED
/*
* If the current rssi is below the configured rssi threshold for
* low rssi based roaming and the current rssi threshold is below that,
* we should reset the rssi threshold back to the configured rssi threshold */
if ((ap_info->rssi > ROAMING_LOW_RSSI_THRESHOLD) && (g_roaming_app.current_low_rssi_threshold < ROAMING_LOW_RSSI_THRESHOLD)) {
g_roaming_app.current_low_rssi_threshold = ROAMING_LOW_RSSI_THRESHOLD;
esp_wifi_set_rssi_threshold(ROAMING_LOW_RSSI_THRESHOLD);
ESP_LOGD(ROAMING_TAG, "Reset the low rssi threshold back to %d", ROAMING_LOW_RSSI_THRESHOLD);
}
#endif /*LOW_RSSI_ROAMING_ENABLED*/
}
#if LEGACY_ROAM_ENABLED
static void legacy_roam_clear_bssid_flag(void)
{
wifi_config_t *config = {0};
config = os_zalloc(sizeof(wifi_config_t));
if (!config) {
ESP_LOGE(ROAMING_TAG, "failed to allocate memory");
return;
}
esp_wifi_get_config(WIFI_IF_STA, config);
if (config->sta.bssid_set) {
config->sta.bssid_set = 0;
esp_wifi_set_config(WIFI_IF_STA, config);
}
os_free(config);
ESP_LOGD(ROAMING_TAG, "cleared bssid flag");
}
#endif /*LEGACY_ROAM_ENABLED*/
static int8_t initialize_roaming_event(void)
{
#if LEGACY_ROAM_ENABLED
/*
* Resetting the Bssid param as it is possible that a previous force
* roam has set config to connect to a specific bssid and now further
* roaming attempts using BTM could lead to a spiral of connecting to
* the previous AP */
if (g_roaming_app.force_roam_ongoing) {
legacy_roam_clear_bssid_flag();
}
#endif /*LEGACY_ROAM_ENABLED*/
return ESP_OK;
}
#if PERIODIC_RRM_MONITORING
static void init_periodic_rrm_event(void)
{
if (!neighbor_list_lock) {
neighbor_list_lock = os_recursive_mutex_create();
if (!neighbor_list_lock) {
ESP_LOGE(ROAMING_TAG, "%s: failed to create roaming neighbor list lock", __func__);
}
}
ESP_LOGV(ROAMING_TAG, "Initialised Periodic RRM Monitoring event!");
g_roaming_app.periodic_rrm_active = true;
if (eloop_register_timeout(RRM_MONITOR_TIME, 0, roaming_app_periodic_rrm_internal_handler, NULL, NULL)) {
ESP_LOGE(ROAMING_TAG, "Could not register periodic neighbor report event.");
}
}
#endif /*PERIODIC_RRM_MONITORING*/
#if PERIODIC_SCAN_MONITORING
static void init_periodic_scan_roam_event(void)
{
ESP_LOGV(ROAMING_TAG, "Initialised Periodic Scan Roam event!");
g_roaming_app.periodic_scan_active = true;
if (eloop_register_timeout(SCAN_MONITOR_INTERVAL, 0, roaming_app_periodic_scan_internal_handler, NULL, NULL)) {
ESP_LOGE(ROAMING_TAG, "Could not register periodic scan monitoring event");
}
}
#endif /*PERIODIC_SCAN_ROAM_MONITORING*/
static void roaming_app_disconnected_event_handler(void* arg, esp_event_base_t event_base,
int32_t event_id, void* event_data)
{
#if PERIODIC_RRM_MONITORING
g_roaming_app.periodic_rrm_active = false;
#endif /*PERIODIC_RRM_MONITORING*/
#if PERIODIC_SCAN_MONITORING
g_roaming_app.periodic_scan_active = false;
#endif /*PERIODIC_SCAN_MONITORING*/
wifi_event_sta_disconnected_t *disconn = event_data;
ESP_LOGD(ROAMING_TAG, "station got disconnected reason=%d", disconn->reason);
if (disconn->reason == WIFI_REASON_ROAMING) {
ESP_LOGD(ROAMING_TAG, "station roaming, do nothing");
} else if (g_roaming_app.allow_reconnect == false) {
ESP_LOGD(ROAMING_TAG, "station initiated disconnect, do nothing");
} else {
#if LEGACY_ROAM_ENABLED
/*
* Resetting the Bssid param as it is possible that a previous force
* roam has set config to connect to a specific bssid and now further
* roaming attempts using BTM could lead to a spiral of connecting to
* the previous AP */
if (g_roaming_app.force_roam_ongoing) {
legacy_roam_clear_bssid_flag();
}
#endif /*LEGACY_ROAM_ENABLED*/
esp_wifi_connect();
}
}
static void roaming_app_sta_stop_event_handler(void* arg, esp_event_base_t event_base,
int32_t event_id, void* event_data)
{
g_roaming_app.allow_reconnect = false;
}
static void roaming_app_connected_event_handler(void* arg, esp_event_base_t event_base,
int32_t event_id, void* event_data)
{
#if LOW_RSSI_ROAMING_ENABLED
roaming_app_get_ap_info(&g_roaming_app.ap_info);
g_roaming_app.scan_params.ssid = g_roaming_app.ap_info.ssid;
if (g_roaming_app.ap_info.rssi < ROAMING_LOW_RSSI_THRESHOLD) {
/* To ensure that the threshold is set to one offset below the current AP RSSI
* in case, the AP is already below the RSSI threshold */
g_roaming_app.current_low_rssi_threshold = g_roaming_app.ap_info.rssi - RSSI_THRESHOLD_REDUCTION_OFFSET;
} else {
g_roaming_app.current_low_rssi_threshold = ROAMING_LOW_RSSI_THRESHOLD;
}
ESP_LOGD(ROAMING_TAG, "setting rssi threshold as %d", g_roaming_app.current_low_rssi_threshold);
esp_wifi_set_rssi_threshold(g_roaming_app.current_low_rssi_threshold);
#endif /*LOW_RSSI_ROAMING_ENABLED*/
g_roaming_app.rrm_support = esp_rrm_is_rrm_supported_connection();
g_roaming_app.btm_support = esp_wnm_is_btm_supported_connection();
ESP_LOGD(ROAMING_TAG, "Station connected, RRM %ssupported, BTM %ssupported",
g_roaming_app.rrm_support ? " " : "not ",
g_roaming_app.btm_support ? " " : "not ");
gettimeofday(&g_roaming_app.last_roamed_time, NULL);
if (!initialize_roaming_event()) {
#if PERIODIC_RRM_MONITORING
if (g_roaming_app.rrm_support) {
init_periodic_rrm_event();
}
#endif /*PERIODIC_RRM_MONITORING*/
#if PERIODIC_SCAN_MONITORING
init_periodic_scan_roam_event();
#endif /*PERIODIC_SCAN_ROAM_MONITORING*/
ESP_LOGD(ROAMING_TAG, "Initialised initialise roaming events!");
} else {
ESP_LOGE(ROAMING_TAG, "Failed to Initialise roaming events");
}
#if LEGACY_ROAM_ENABLED
g_roaming_app.force_roam_ongoing = true;
#endif /*LEGACY_ROAM_ENABLED*/
g_roaming_app.allow_reconnect = true;
}
#define MAX_NEIGHBOR_LEN 512
#if PERIODIC_RRM_MONITORING
static char * get_btm_neighbor_list(uint8_t *report, size_t report_len)
{
size_t len = 0;
const uint8_t *data;
int ret = 0;
/*
* Neighbor Report element (IEEE P802.11-REVmc/D5.0)
* BSSID[6]
* BSSID Information[4]
* Operating Class[1]
* Channel Number[1]
* PHY Type[1]
* Optional Subelements[variable]
*/
#define NR_IE_MIN_LEN (ETH_ALEN + 4 + 1 + 1 + 1)
if (!report || report_len == 0) {
ESP_LOGE(ROAMING_TAG, "RRM neighbor report is not valid");
return NULL;
}
char *buf = os_calloc(1, MAX_NEIGHBOR_LEN);
if (!buf) {
ESP_LOGE(ROAMING_TAG, "get_btm_list : Memory alloc failed for buf");
return NULL;
}
data = report;
while (report_len >= 2 + NR_IE_MIN_LEN) {
const uint8_t *nr;
uint8_t nr_len = data[1];
const uint8_t *pos = data, *end;
if (pos[0] != WLAN_EID_NEIGHBOR_REPORT ||
nr_len < NR_IE_MIN_LEN) {
ESP_LOGD(ROAMING_TAG, "CTRL: Invalid Neighbor Report element: id=%u len=%u",
data[0], nr_len);
ret = -1;
goto cleanup;
}
if (2U + nr_len > report_len) {
ESP_LOGD(ROAMING_TAG, "CTRL: Invalid Neighbor Report element: id=%u len=%zu nr_len=%u",
data[0], report_len, nr_len);
ret = -1;
goto cleanup;
}
pos += 2;
end = pos + nr_len;
nr = pos;
pos += NR_IE_MIN_LEN;
while (end - pos > 2) {
uint8_t s_len;
s_len = *pos++;
if (s_len > end - pos) {
ret = -1;
goto cleanup;
}
pos += s_len;
}
ESP_LOGD(ROAMING_TAG, "RMM neighbor report bssid=" MACSTR
" info=0x%" PRIx32 " op_class=%u chan=%u phy_type=%u",
MAC2STR(nr), WPA_GET_LE32(nr + ETH_ALEN),
nr[ETH_ALEN + 4], nr[ETH_ALEN + 5],
nr[ETH_ALEN + 6]);
/* neighbor start */
len += snprintf(buf + len, MAX_NEIGHBOR_LEN - len, " neighbor=");
/* bssid */
len += snprintf(buf + len, MAX_NEIGHBOR_LEN - len, MACSTR, MAC2STR(nr));
/* , */
len += snprintf(buf + len, MAX_NEIGHBOR_LEN - len, ",");
/* bssid info */
len += snprintf(buf + len, MAX_NEIGHBOR_LEN - len, "0x%04" PRIx32 "", WPA_GET_LE32(nr + ETH_ALEN));
len += snprintf(buf + len, MAX_NEIGHBOR_LEN - len, ",");
/* operating class */
len += snprintf(buf + len, MAX_NEIGHBOR_LEN - len, "%u", nr[ETH_ALEN + 4]);
len += snprintf(buf + len, MAX_NEIGHBOR_LEN - len, ",");
/* channel number */
len += snprintf(buf + len, MAX_NEIGHBOR_LEN - len, "%u", nr[ETH_ALEN + 5]);
len += snprintf(buf + len, MAX_NEIGHBOR_LEN - len, ",");
/* phy type */
len += snprintf(buf + len, MAX_NEIGHBOR_LEN - len, "%u", nr[ETH_ALEN + 6]);
/* optional elements, skip */
data = end;
report_len -= 2 + nr_len;
}
cleanup:
if (ret < 0) {
os_free(buf);
buf = NULL;
}
return buf;
}
static void roaming_app_neighbor_report_recv_handler(void* arg, esp_event_base_t event_base, int32_t event_id, void* event_data)
{
if (!g_roaming_app.rrm_request_active) {
ESP_LOGV(ROAMING_TAG, "Not the response for our Neighbor Report Request");
return;
}
g_roaming_app.rrm_request_active = false;
if (!event_data) {
ESP_LOGE(ROAMING_TAG, "No data received for neighbor report");
return;
}
wifi_event_neighbor_report_t *neighbor_report_event = (wifi_event_neighbor_report_t*)event_data;
ESP_LOGD(ROAMING_TAG, "Received cb for Neighbor Report Request");
uint8_t *pos = (uint8_t *)neighbor_report_event->report;
if (!pos) {
ESP_LOGE(ROAMING_TAG, "Neighbor report is empty");
return;
}
uint8_t report_len = neighbor_report_event->report_len;
/* dump report info */
ESP_LOGD(ROAMING_TAG, "rrm: neighbor report len=%d", report_len);
ESP_LOG_BUFFER_HEXDUMP(ROAMING_TAG, pos, report_len, ESP_LOG_DEBUG);
ROAM_NEIGHBOR_LIST_LOCK();
if (g_roaming_app.btm_neighbor_list) {
os_free(g_roaming_app.btm_neighbor_list);
g_roaming_app.btm_neighbor_list = NULL;
}
/* create neighbor list */
g_roaming_app.btm_neighbor_list = get_btm_neighbor_list(pos + 1, report_len - 1);
ROAM_NEIGHBOR_LIST_UNLOCK();
}
#endif /*PERIODIC_RRM_MONITORING*/
#if LOW_RSSI_ROAMING_ENABLED
static void roaming_app_rssi_low_handler(void* arg, esp_event_base_t event_base, int32_t event_id, void* event_data)
{
wifi_event_bss_rssi_low_t *event = event_data;
ESP_LOGI(ROAMING_TAG, "%s:bss rssi is=%ld", __func__, event->rssi);
roaming_app_get_ap_info(&g_roaming_app.ap_info);
determine_best_ap(0);
g_roaming_app.current_low_rssi_threshold -= RSSI_THRESHOLD_REDUCTION_OFFSET;
ESP_LOGD(ROAMING_TAG, "Resetting RSSI Threshold to %d", g_roaming_app.current_low_rssi_threshold);
esp_wifi_set_rssi_threshold(g_roaming_app.current_low_rssi_threshold);
}
#endif
#if NETWORK_ASSISTED_ROAMING_ENABLED
static void trigger_network_assisted_roam(void)
{
#if PERIODIC_RRM_MONITORING
ROAM_NEIGHBOR_LIST_LOCK();
#endif /*PERIODIC_RRM_MONITORING*/
if (esp_wnm_send_bss_transition_mgmt_query(REASON_RSSI, g_roaming_app.btm_neighbor_list, 1) < 0) {
ESP_LOGD(ROAMING_TAG, "failed to send btm query");
}
#if PERIODIC_RRM_MONITORING
ROAM_NEIGHBOR_LIST_UNLOCK();
#endif /*PERIODIC_RRM_MONITORING*/
ESP_LOGD(ROAMING_TAG, "Sent BTM Query");
gettimeofday(&g_roaming_app.last_roamed_time, NULL);
g_roaming_app.btm_attempt++;
}
#endif /*NETWORK_ASSISTED_ROAMING*/
#if LEGACY_ROAM_ENABLED
static void trigger_legacy_roam(struct cand_bss *bss)
{
wifi_config_t wifi_cfg = {0};
esp_wifi_get_config(WIFI_IF_STA, &wifi_cfg);
wifi_cfg.sta.channel = bss->channel;
wifi_cfg.sta.bssid_set = true;
os_memcpy(wifi_cfg.sta.bssid, bss->bssid, ETH_ALEN);
esp_wifi_internal_issue_disconnect(WIFI_REASON_BSS_TRANSITION_DISASSOC);
esp_wifi_set_config(WIFI_IF_STA, &wifi_cfg);
esp_wifi_connect();
ESP_LOGI(ROAMING_TAG, "Disconnecting and connecting to "MACSTR" on account of better rssi",MAC2STR(bss->bssid));
gettimeofday(&g_roaming_app.last_roamed_time, NULL);
g_roaming_app.force_roam_ongoing = true;
}
#endif /*LEGACY_ROAM_ENABLED*/
void roaming_app_trigger_roam(struct cand_bss *bss)
{
struct timeval now;
gettimeofday(&now, NULL);
ESP_LOGD(ROAMING_TAG,"Processing trigger roaming request.");
if (time_diff_sec(&now, &g_roaming_app.last_roamed_time) < ROAMING_BACKOFF_TIME ) {
ESP_LOGD(ROAMING_TAG,"Ignoring request as time difference to last request is %ld",time_diff_sec(&now, &g_roaming_app.last_roamed_time));
goto free_bss;
}
#if NETWORK_ASSISTED_ROAMING_ENABLED
if (g_roaming_app.btm_support) {
#if LEGACY_ROAM_ENABLED && NETWORK_ASSISTED_ROAMING_ENABLED
if (g_roaming_app.btm_attempt <= BSS_TM_RETRY_COUNT) {
#endif
trigger_network_assisted_roam();
goto free_bss;
#if LEGACY_ROAM_ENABLED && NETWORK_ASSISTED_ROAMING_ENABLED
} else {
ESP_LOGD(ROAMING_TAG, "Not Sending BTM query as this method has failed too many times.");
g_roaming_app.btm_attempt = 0;
}
#endif
}
#endif /*NETWORK_ASSISTED_ROAMING_ENABLED*/
#if LEGACY_ROAM_ENABLED
trigger_legacy_roam(bss);
#endif /*LEGACY_ROAM_ENABLED*/
free_bss :
os_free(bss);
}
void roaming_app_trigger_roam_internal_handler(void *ctx, void *data)
{
if (!data) {
ESP_LOGE(ROAMING_TAG, "No data received for roaming event");
} else {
roaming_app_trigger_roam((struct cand_bss *)data);
}
}
static int wifi_post_roam_event(struct cand_bss *bss)
{
if (bss) {
struct cand_bss *cand_bss = (struct cand_bss *)os_zalloc(sizeof(struct cand_bss));
if (!cand_bss) {
ESP_LOGE(ROAMING_TAG, "Cannot allocate data for roaming event");
return -1;
}
os_memcpy(cand_bss, bss, sizeof(struct cand_bss));
/* trigger the roaming event */
if (eloop_register_timeout(0, 0, roaming_app_trigger_roam_internal_handler, NULL, (void*)cand_bss)) {
ESP_LOGE(ROAMING_TAG, "Could not register roaming event.");
os_free(cand_bss);
return -1;
}
} else {
ESP_LOGE(ROAMING_TAG, "Cannot trigger roaming event without any candidate APs");
return -1;
}
return 0;
}
void print_ap_records(struct scanned_ap_info *ap_info)
{
ESP_LOGD(ROAMING_TAG, "Scanned AP List");
for (int i = 0; i < ap_info->current_count ; i++) {
ESP_LOGD(ROAMING_TAG, "%d. ssid : %s bssid :"MACSTR" channel : %d rssi : %d authmode : %d", i,
ap_info->ap_records[i].ssid,MAC2STR(ap_info->ap_records[i].bssid),
ap_info->ap_records[i].primary,ap_info->ap_records[i].rssi, ap_info->ap_records[i].authmode);
}
}
#if PERIODIC_RRM_MONITORING
static void periodic_rrm_request(struct timeval *now)
{
roaming_app_get_ap_info(&g_roaming_app.ap_info);
if (esp_rrm_is_rrm_supported_connection() && (g_roaming_app.ap_info.rssi < RRM_MONITOR_RSSI_THRESHOLD)) {
if (esp_rrm_send_neighbor_report_request() < 0) {
ESP_LOGE(ROAMING_TAG, "failed to send neighbor report request");
return;
}
g_roaming_app.rrm_request_active = true;
}
}
#endif
static bool candidate_security_match(wifi_ap_record_t candidate)
{
wifi_auth_mode_t curr_auth = g_roaming_app.ap_info.authmode;
wifi_auth_mode_t cand_auth = candidate.authmode;
ESP_LOGV(ROAMING_TAG, "Cand authmode : %d, Current Authmode : %d", cand_auth, curr_auth);
if (cand_auth == curr_auth) {
ESP_LOGV(ROAMING_TAG, "Authmode matched!");
return true;
}
wifi_config_t wifi_cfg = {0};
esp_wifi_get_config(WIFI_IF_STA, &wifi_cfg);
if (wifi_cfg.sta.owe_enabled && OWE_COMPATIBLE(curr_auth, cand_auth)) {
/*
* OWE <--> Open allowed if threshold is Open
*/
if (wifi_cfg.sta.threshold.authmode == WIFI_AUTH_OPEN) {
ESP_LOGV(ROAMING_TAG, "transition between OWE and open permitted");
return true;
} else {
ESP_LOGV(ROAMING_TAG, "transition between OWE and open not permitted");
return false;
}
} else if (wifi_cfg.sta.threshold.authmode > cand_auth) {
/* If the authmode of the candidate AP is less than our threshold, it
* will fail during connection*/
ESP_LOGV(ROAMING_TAG, "Authmode threshold failure %d -> %d", wifi_cfg.sta.threshold.authmode, cand_auth);
return false;
} else if (PSK_COMPATIBLE(curr_auth, cand_auth)) {
/*
* PSK based authmodes are compatible with each other for roaming
*/
ESP_LOGV(ROAMING_TAG, "Roaming between a PSK APs");
return true;
}
return false;
}
static bool candidate_profile_match(wifi_ap_record_t candidate)
{
return candidate_security_match(candidate);
}
/* Remember to always call this function with the ROAM_SCAN_RESULTS_LOCK */
static void parse_scan_results_and_roam(void)
{
int8_t rssi_threshold = g_roaming_app.current_rssi_threshold;
uint8_t best_rssi_diff = rssi_threshold;
struct cand_bss *best_ap = NULL;
int8_t rssi_diff = 0;
uint8_t i;
int8_t best_ap_index = -1;
wifi_ap_record_t ap_info;
roaming_app_get_ap_info(&ap_info);
for (i = 0; i < g_roaming_app.scanned_aps.current_count; i++) {
rssi_diff = g_roaming_app.scanned_aps.ap_records[i].rssi - ap_info.rssi;
ESP_LOGD(ROAMING_TAG, "The difference between ("MACSTR", "MACSTR") with rssi (%d,%d) is : %d while the threshold is %d and the best rssi diff yet is %d, thecand_auth is %d",
MAC2STR(g_roaming_app.scanned_aps.ap_records[i].bssid),MAC2STR(ap_info.bssid),
g_roaming_app.scanned_aps.ap_records[i].rssi, ap_info.rssi,
rssi_diff, rssi_threshold, best_rssi_diff, g_roaming_app.scanned_aps.ap_records[i].authmode);
if ((memcmp(g_roaming_app.scanned_aps.ap_records[i].bssid, ap_info.bssid, ETH_ALEN) != 0) &&
candidate_profile_match(g_roaming_app.scanned_aps.ap_records[i]) && rssi_diff > best_rssi_diff ) {
best_rssi_diff = rssi_diff;
best_ap_index = i;
}
}
if (best_ap_index >= 0) {
best_ap = (struct cand_bss*)os_zalloc(sizeof(struct cand_bss));
if (!best_ap) {
ESP_LOGE(ROAMING_TAG,"Memory Allocation for candidate bss failed");
return;
}
os_memcpy(best_ap->bssid,g_roaming_app.scanned_aps.ap_records[best_ap_index].bssid , ETH_ALEN);
best_ap->channel = g_roaming_app.scanned_aps.ap_records[best_ap_index].primary;
}
if (best_ap) {
ESP_LOGI(ROAMING_TAG,"Found a better AP "MACSTR" at channel %d", MAC2STR(best_ap->bssid), best_ap->channel);
if (wifi_post_roam_event(best_ap)) {
ESP_LOGE(ROAMING_TAG, "Posting of roaming event failed");
}
os_free(best_ap);
} else {
ESP_LOGI(ROAMING_TAG, "Could not find a better AP with the threshold set to %d", g_roaming_app.current_rssi_threshold + 1);
}
}
static void scan_done_event_handler(void *arg, ETS_STATUS status)
{
if (status == ETS_OK) {
ROAM_SCAN_RESULTS_LOCK();
ESP_LOGD(ROAMING_TAG, "Scan Done properly");
g_roaming_app.scanned_aps.current_count = MAX_CANDIDATE_COUNT;
esp_wifi_scan_get_ap_records(&g_roaming_app.scanned_aps.current_count, g_roaming_app.scanned_aps.ap_records);
print_ap_records(&g_roaming_app.scanned_aps);
parse_scan_results_and_roam();
g_roaming_app.scan_ongoing = false;
ROAM_SCAN_RESULTS_UNLOCK();
} else {
ESP_LOGD(ROAMING_TAG, "Scan Done with error %d ", status);
}
}
static void conduct_scan(void)
{
/* Update scan time in global structure */
gettimeofday(&g_roaming_app.scanned_aps.time, NULL);
/* Issue scan */
os_memset(&g_roaming_app.scanned_aps, 0, sizeof(struct scanned_ap_info));
if (esp_wifi_promiscuous_scan_start(&g_roaming_app.scan_params, scan_done_event_handler) < 0) {
ESP_LOGE(ROAMING_TAG, "failed to issue scan");
return;
}
ESP_LOGI(ROAMING_TAG, "Issued Scan");
}
static void determine_best_ap(int8_t rssi_threshold)
{
struct timeval now;
gettimeofday(&now, NULL);
ROAM_SCAN_RESULTS_LOCK();
/* If the scan results are recent enough or a scan is already ongoing we should not trigger a new scan */
if (!g_roaming_app.scan_ongoing) {
g_roaming_app.scan_ongoing = true;
g_roaming_app.current_rssi_threshold = rssi_threshold;
if (time_diff_sec(&now,&g_roaming_app.scanned_aps.time) > SCAN_RESULTS_USABILITY_WINDOW) {
conduct_scan();
} else {
parse_scan_results_and_roam();
g_roaming_app.scan_ongoing = false;
}
} else if(rssi_threshold < g_roaming_app.current_rssi_threshold) {
g_roaming_app.current_rssi_threshold = rssi_threshold;
}
ROAM_SCAN_RESULTS_UNLOCK();
}
#if PERIODIC_SCAN_MONITORING
static void periodic_scan_roam(struct timeval *now)
{
#if NETWORK_ASSISTED_ROAMING_ENABLED && !LEGACY_ROAM_ENABLED
/*
* In case we support only network assisted roaming, there is no need to scan
* if we currently have over 10secs to go for backoff time to expire
* as the results produced by a scan at this time would not be used by
* supplicant to build candidate lists.
* */
if (time_diff_sec(now, &g_roaming_app.last_roamed_time) < ROAMING_BACKOFF_TIME - SUPPLICANT_CANDIDATE_LIST_EXPIRY) {
return;
}
#endif /*NETWORK_ASSISTED_ROAMING_ENABLED && !LEGACY_ROAM_ENABLED*/
/* If the current RSSI is not worse than the configured threshold
* for station initiated roam, then do not trigger roam */
roaming_app_get_ap_info(&g_roaming_app.ap_info);
if (g_roaming_app.ap_info.rssi > SCAN_MONITOR_RSSI_THRESHOLD) {
return;
}
determine_best_ap(SCAN_ROAM_RSSI_DIFF - 1);
}
#endif /*PERIODIC_SCAN_MONITORING*/
#if PERIODIC_RRM_MONITORING
void roaming_app_periodic_rrm_internal_handler(void *data, void *ctx)
{
struct timeval now;
if (g_roaming_app.periodic_rrm_active) {
ESP_LOGD(ROAMING_TAG,"Triggered periodic rrm event!");
gettimeofday(&now, NULL);
/* This will be done every RRM_MONITOR_TIME */
periodic_rrm_request(&now);
if (eloop_register_timeout(RRM_MONITOR_TIME, 0, roaming_app_periodic_rrm_internal_handler, NULL, NULL)) {
ESP_LOGE(ROAMING_TAG,"Could not register periodic neighbor report request event.");
}
}
}
#endif /*PERIODIC_RRM_MONITORING*/
#if PERIODIC_SCAN_MONITORING
void roaming_app_periodic_scan_internal_handler(void *data, void *ctx)
{
struct timeval now;
if (g_roaming_app.periodic_scan_active) {
ESP_LOGD(ROAMING_TAG,"Started the periodic scan roam event!");
gettimeofday(&now, NULL);
/* This will be done every SCAN_MONITOR_INTERVAL */
periodic_scan_roam(&now);
if (eloop_register_timeout(SCAN_MONITOR_INTERVAL, 0, roaming_app_periodic_scan_internal_handler, NULL, NULL)) {
ESP_LOGE(ROAMING_TAG,"Could not register periodic scan event.");
}
}
}
#endif /*PERIODIC_SCAN_ROAM_MONITORING*/
static bool validate_scan_chan_list(const char* scan_chan_list)
{
regex_t regex;
const char* pattern = "^[0-9]+(,[0-9]+)*$";
uint8_t ret = regcomp(®ex, pattern, REG_EXTENDED);
if (ret != 0) {
ESP_LOGE(ROAMING_TAG, "Regex compilation failed.");
return false;
}
ret = regexec(®ex, scan_chan_list, 0, NULL, 0);
regfree(®ex);
if (ret == REG_NOMATCH) {
return false;
}
/* Check for consecutive commas or comma at start/end */
if (strstr(scan_chan_list, ",,") != NULL || scan_chan_list[0] == ',' || scan_chan_list[strlen(scan_chan_list) - 1] == ',') {
return false;
}
return true;
}
static int8_t parse_scan_chan_list(void)
{
int8_t ret = 0;
char *scan_chan_string = NULL;
if (validate_scan_chan_list(SCAN_PREFERRED_CHAN_LIST) == false) {
ESP_LOGE(ROAMING_TAG, "scan chan list validation failed.");
ret = -1;
goto cleanup;
}
scan_chan_string = (char *)os_zalloc(sizeof(char) * strlen(SCAN_PREFERRED_CHAN_LIST) + 1);
if (scan_chan_string == NULL) {
ESP_LOGE(ROAMING_TAG, "Memory allocation failed.");
ret = -1;
goto cleanup;
}
strlcpy(scan_chan_string, SCAN_PREFERRED_CHAN_LIST, strlen(SCAN_PREFERRED_CHAN_LIST) + 1);
char* token;
token = strsep(&scan_chan_string, ",");
g_roaming_app.scan_params.channel_bitmap.ghz_2_channels = 0;
while (token != NULL) {
uint8_t channel = atoi(token);
/* Check if the number is within the required range */
if (channel >= 1 && channel <= 14) {
/* Check if the number is already present in the array */
g_roaming_app.scan_params.channel_bitmap.ghz_2_channels |= (1 << channel);
} else {
ESP_LOGE(ROAMING_TAG, "Channel out of range: %d", channel);
ret = -1;
goto cleanup;
}
token = strsep(&scan_chan_string, ",");
}
cleanup:
if (scan_chan_string) {
os_free(scan_chan_string);
}
return ret;
}
esp_err_t init_scan_params(void)
{
if (!scan_results_lock) {
scan_results_lock = os_recursive_mutex_create();
if (!scan_results_lock) {
ESP_LOGE(ROAMING_TAG, "%s: failed to create scan results lock", __func__);
return ESP_FAIL;
}
}
if (strcmp(DEFAULT_PREFERRED_SCAN_CHAN_LIST, SCAN_PREFERRED_CHAN_LIST)) {
ESP_ERROR_CHECK(parse_scan_chan_list());
}
g_roaming_app.scan_params.scan_type = 0;
g_roaming_app.scan_params.scan_time.active.min = SCAN_TIME_MIN_DURATION;
g_roaming_app.scan_params.scan_time.active.max = SCAN_TIME_MAX_DURATION;
g_roaming_app.scan_params.home_chan_dwell_time = HOME_CHANNEL_DWELL_TIME;
gettimeofday(&g_roaming_app.scanned_aps.time, NULL);
return ESP_OK;
}
void init_roaming_app(void)
{
#if !LOW_RSSI_ROAMING_ENABLED && !PERIODIC_SCAN_MONITORING
ESP_LOGE(ROAMING_TAG, "No roaming trigger enabled. Roaming app cannot be initialized");
return;
#endif
#if !NETWORK_ASSISTED_ROAMING_ENABLED && !LEGACY_ROAM_ENABLED
ESP_LOGE(ROAMING_TAG, "No roaming method enabled. Roaming app cannot be initialized");
return;
#endif
ESP_ERROR_CHECK(esp_event_handler_register(WIFI_EVENT, WIFI_EVENT_STA_CONNECTED, roaming_app_connected_event_handler, NULL));
ESP_ERROR_CHECK(esp_event_handler_register(WIFI_EVENT, WIFI_EVENT_STA_DISCONNECTED, roaming_app_disconnected_event_handler, NULL));
ESP_ERROR_CHECK(esp_event_handler_register(WIFI_EVENT, WIFI_EVENT_STA_STOP, roaming_app_sta_stop_event_handler, NULL));
#if LOW_RSSI_ROAMING_ENABLED
ESP_ERROR_CHECK(esp_event_handler_register(WIFI_EVENT, WIFI_EVENT_STA_BSS_RSSI_LOW,
&roaming_app_rssi_low_handler, NULL));
#endif /*ROAMING_LOW_RSSI_THRESHOLD*/
ESP_ERROR_CHECK(init_scan_params());
#if PERIODIC_RRM_MONITORING
ESP_ERROR_CHECK(esp_event_handler_register(WIFI_EVENT, WIFI_EVENT_STA_NEIGHBOR_REP,
&roaming_app_neighbor_report_recv_handler, NULL));
#endif /*PERIODIC_RRM_MONITORING*/
ESP_LOGI(ROAMING_TAG, "Roaming app initialization done");
}
void deinit_roaming_app(void)
{
#if !LOW_RSSI_ROAMING_ENABLED && !PERIODIC_SCAN_MONITORING
ESP_LOGE(ROAMING_TAG, "No roaming trigger enabled. Roaming app cannot be de-initialized");
return;
#endif
#if !NETWORK_ASSISTED_ROAMING_ENABLED && !LEGACY_ROAM_ENABLED
ESP_LOGE(ROAMING_TAG, "No roaming trigger enabled. Roaming app cannot be de-initialized");
return;
#endif
/* Unregister Event handlers */
ESP_ERROR_CHECK(esp_event_handler_unregister(WIFI_EVENT, WIFI_EVENT_STA_CONNECTED, roaming_app_connected_event_handler));
ESP_ERROR_CHECK(esp_event_handler_unregister(WIFI_EVENT, WIFI_EVENT_STA_DISCONNECTED, roaming_app_disconnected_event_handler));
ESP_ERROR_CHECK(esp_event_handler_unregister(WIFI_EVENT, WIFI_EVENT_STA_STOP, roaming_app_sta_stop_event_handler));
#if LOW_RSSI_ROAMING_ENABLED
ESP_ERROR_CHECK(esp_event_handler_unregister(WIFI_EVENT, WIFI_EVENT_STA_BSS_RSSI_LOW,
&roaming_app_rssi_low_handler));
#endif /*ROAMING_LOW_RSSI_THRESHOLD*/
#if PERIODIC_RRM_MONITORING
ESP_ERROR_CHECK(esp_event_handler_unregister(WIFI_EVENT, WIFI_EVENT_STA_NEIGHBOR_REP,
&roaming_app_neighbor_report_recv_handler));
#endif /*PERIODIC_RRM_MONITORING*/
/* Disabling the periodic scan and RRM events */
#if PERIODIC_RRM_MONITORING
g_roaming_app.periodic_rrm_active = false;
#endif /*PERIODIC_RRM_MONITORING*/
#if PERIODIC_SCAN_MONITORING
g_roaming_app.periodic_scan_active = false;
#endif /*PERIODIC_SCAN_MONITORING*/
#if PERIODIC_RRM_MONITORING
if (neighbor_list_lock) {
os_mutex_delete(neighbor_list_lock);
neighbor_list_lock = NULL;
}
#endif /*PERIODIC_RRM_MONITORING*/
if (scan_results_lock) {
os_mutex_delete(scan_results_lock);
scan_results_lock = NULL;
}
}
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