android wifi驱动流程图,Android WiFi 扫描流程分析(wpa_supplicant选择网络)
扫描流程
1.如果之前就已经有相关记录，优化扫描，扫描记录部分的频率信道。
2.如果1中的扫描没有结果，清除黑名单中的进行选择。
3.如果2中没有结果，进行所有频率的信道进行扫描
相关log参考:
https://www.cnblogs.com/helloworldtoyou/p/9958084.html
external\wpa_supplicant_8\wpa_supplicant\src\drivers\driver_nl80211_event.c
static void do_process_drv_event(struct i802_bss *bss, int cmd,
struct nlattr **tb)
{
struct wpa_driver_nl80211_data *drv = bss->drv;
union wpa_event_data data;
int external_scan_event = 0;
wpa_printf(MSG_DEBUG, "nl80211: Drv Event %d (%s) received for %s",
cmd, nl80211_command_to_string(cmd), bss->ifname);
if (cmd == NL80211_CMD_ROAM &&
(drv->capa.flags & WPA_DRIVER_FLAGS_KEY_MGMT_OFFLOAD)) {
/*
* Device will use roam+auth vendor event to indicate
* roaming, so ignore the regular roam event.
*/
wpa_printf(MSG_DEBUG,
"nl80211: Ignore roam event (cmd=%d), device will use vendor event roam+auth",
cmd);
return;
}
if (drv->ap_scan_as_station != NL80211_IFTYPE_UNSPECIFIED &&
(cmd == NL80211_CMD_NEW_SCAN_RESULTS ||
cmd == NL80211_CMD_SCAN_ABORTED)) {
wpa_driver_nl80211_set_mode(drv->first_bss,
drv->ap_scan_as_station);
drv->ap_scan_as_station = NL80211_IFTYPE_UNSPECIFIED;
}
switch (cmd) {
case NL80211_CMD_TRIGGER_SCAN:
wpa_dbg(drv->ctx, MSG_DEBUG, "nl80211: Scan trigger");
drv->scan_state = SCAN_STARTED;
if (drv->scan_for_auth) {
/*
* Cannot indicate EVENT_SCAN_STARTED here since we skip
* EVENT_SCAN_RESULTS in scan_for_auth case and the
* upper layer implementation could get confused about
* scanning state.
*/
wpa_printf(MSG_DEBUG, "nl80211: Do not indicate scan-start event due to internal scan_for_auth");
break;
}
wpa_supplicant_event(drv->ctx, EVENT_SCAN_STARTED, NULL);
break;
case NL80211_CMD_START_SCHED_SCAN:
wpa_dbg(drv->ctx, MSG_DEBUG, "nl80211: Sched scan started");
drv->scan_state = SCHED_SCAN_STARTED;
break;
case NL80211_CMD_SCHED_SCAN_STOPPED:
wpa_dbg(drv->ctx, MSG_DEBUG, "nl80211: Sched scan stopped");
drv->scan_state = SCHED_SCAN_STOPPED;
wpa_supplicant_event(drv->ctx, EVENT_SCHED_SCAN_STOPPED, NULL);
break;
case NL80211_CMD_NEW_SCAN_RESULTS:
wpa_dbg(drv->ctx, MSG_DEBUG,
"nl80211: New scan results available");
if (drv->last_scan_cmd != NL80211_CMD_VENDOR)
drv->scan_state = SCAN_COMPLETED;
drv->scan_complete_events = 1;
if (drv->last_scan_cmd == NL80211_CMD_TRIGGER_SCAN) {
eloop_cancel_timeout(wpa_driver_nl80211_scan_timeout,
drv, drv->ctx);
drv->last_scan_cmd = 0;
} else {
external_scan_event = 1;
}
send_scan_event(drv, 0, tb, external_scan_event);
break;
}
static void send_scan_event(struct wpa_driver_nl80211_data *drv, int aborted,
struct nlattr *tb[], int external_scan)
{
union wpa_event_data event;
struct nlattr *nl;
int rem;
struct scan_info *info;
#define MAX_REPORT_FREQS 50
int freqs[MAX_REPORT_FREQS];
int num_freqs = 0;
if (!external_scan && drv->scan_for_auth) {
drv->scan_for_auth = 0;
wpa_printf(MSG_DEBUG, "nl80211: Scan results for missing "
"cfg80211 BSS entry");
wpa_driver_nl80211_authenticate_retry(drv);
return;
}
os_memset(&event, 0, sizeof(event));
info = &event.scan_info;
info->aborted = aborted;
info->external_scan = external_scan;
info->nl_scan_event = 1;
if (tb[NL80211_ATTR_SCAN_SSIDS]) {
nla_for_each_nested(nl, tb[NL80211_ATTR_SCAN_SSIDS], rem) {
struct wpa_driver_scan_ssid *s =
&info->ssids[info->num_ssids];
s->ssid = nla_data(nl);
s->ssid_len = nla_len(nl);
wpa_printf(MSG_DEBUG, "nl80211: Scan probed for SSID '%s'",
wpa_ssid_txt(s->ssid, s->ssid_len));
info->num_ssids++;
if (info->num_ssids == WPAS_MAX_SCAN_SSIDS)
break;
}
}
if (tb[NL80211_ATTR_SCAN_FREQUENCIES]) {
char msg[300], *pos, *end;
int res;
pos = msg;
end = pos + sizeof(msg);
*pos = '\0';
nla_for_each_nested(nl, tb[NL80211_ATTR_SCAN_FREQUENCIES], rem)
{
freqs[num_freqs] = nla_get_u32(nl);
res = os_snprintf(pos, end - pos, " %d",
freqs[num_freqs]);
if (!os_snprintf_error(end - pos, res))
pos += res;
num_freqs++;
if (num_freqs == MAX_REPORT_FREQS - 1)
break;
}
info->freqs = freqs;
info->num_freqs = num_freqs;
// 显示扫面结果中包含的频率
//10-26 20:35:38.999 2215 2215 D wpa_supplicant: wlan0: nl80211: New scan results available
//10-26 20:35:39.000 2215 2215 D wpa_supplicant: nl80211: Scan included frequencies: 5805 5240 5745 5200 5180 5220 2437 5785 2462 57
wpa_printf(MSG_DEBUG, "nl80211: Scan included frequencies:%s",
msg);
}
if (tb[NL80211_ATTR_SCAN_START_TIME_TSF] &&
tb[NL80211_ATTR_SCAN_START_TIME_TSF_BSSID]) {
info->scan_start_tsf =
nla_get_u64(tb[NL80211_ATTR_SCAN_START_TIME_TSF]);
os_memcpy(info->scan_start_tsf_bssid,
nla_data(tb[NL80211_ATTR_SCAN_START_TIME_TSF_BSSID]),
ETH_ALEN);
}
wpa_supplicant_event(drv->ctx, EVENT_SCAN_RESULTS, &event);
}
Z:\eda51\external\wpa_supplicant_8\wpa_supplicant\events.c
void wpa_supplicant_event(void *ctx, enum wpa_event_type event,
union wpa_event_data *data)
{
struct wpa_supplicant *wpa_s = ctx;
int resched;
if (wpa_s->wpa_state == WPA_INTERFACE_DISABLED &&
event != EVENT_INTERFACE_ENABLED &&
event != EVENT_INTERFACE_STATUS &&
event != EVENT_SCAN_RESULTS &&
event != EVENT_SCHED_SCAN_STOPPED) {
wpa_dbg(wpa_s, MSG_DEBUG,
"Ignore event %s (%d) while interface is disabled",
event_to_string(event), event);
return;
}
#ifndef CONFIG_NO_STDOUT_DEBUG
{
int level = MSG_DEBUG;
if (event == EVENT_RX_MGMT && data->rx_mgmt.frame_len >= 24) {
const struct ieee80211_hdr *hdr;
u16 fc;
hdr = (const struct ieee80211_hdr *) data->rx_mgmt.frame;
fc = le_to_host16(hdr->frame_control);
if (WLAN_FC_GET_TYPE(fc) == WLAN_FC_TYPE_MGMT &&
WLAN_FC_GET_STYPE(fc) == WLAN_FC_STYPE_BEACON)
level = MSG_EXCESSIVE;
}
// wpa_supplicant: wlan0: Event SCAN_RESULTS (3) received
wpa_dbg(wpa_s, level, "Event %s (%d) received",
event_to_string(event), event);
}
#endif /* CONFIG_NO_STDOUT_DEBUG */
switch (event) {
case EVENT_AUTH:
#ifdef CONFIG_FST
if (!wpas_fst_update_mbie(wpa_s, data->auth.ies,
data->auth.ies_len))
wpa_printf(MSG_DEBUG,
"FST: MB IEs updated from auth IE");
#endif /* CONFIG_FST */
sme_event_auth(wpa_s, data);
break;
case EVENT_ASSOC:
#ifdef CONFIG_TESTING_OPTIONS
if (wpa_s->ignore_auth_resp) {
wpa_printf(MSG_INFO,
"EVENT_ASSOC - ignore_auth_resp active!");
break;
}
#endif /* CONFIG_TESTING_OPTIONS */
wpa_supplicant_event_assoc(wpa_s, data);
if (data &&
(data->assoc_info.authorized ||
(!(wpa_s->drv_flags & WPA_DRIVER_FLAGS_SME) &&
wpa_fils_is_completed(wpa_s->wpa))))
wpa_supplicant_event_assoc_auth(wpa_s, data);
if (data) {
wpa_msg(wpa_s, MSG_INFO,
WPA_EVENT_SUBNET_STATUS_UPDATE "status=%u",
data->assoc_info.subnet_status);
}
break;
case EVENT_SCAN_RESULTS:
if (wpa_s->wpa_state == WPA_INTERFACE_DISABLED) {
wpa_s->scan_res_handler = NULL;
wpa_s->own_scan_running = 0;
wpa_s->radio->external_scan_running = 0;
wpa_s->last_scan_req = NORMAL_SCAN_REQ;
break;
}
if (!(data && data->scan_info.external_scan) &&
os_reltime_initialized(&wpa_s->scan_start_time)) {
struct os_reltime now, diff;
os_get_reltime(&now);
os_reltime_sub(&now, &wpa_s->scan_start_time, &diff);
wpa_s->scan_start_time.sec = 0;
wpa_s->scan_start_time.usec = 0;
wpa_dbg(wpa_s, MSG_DEBUG, "Scan completed in %ld.%06ld seconds",
diff.sec, diff.usec);
}
if (wpa_supplicant_event_scan_results(wpa_s, data))
break; /* interface may have been removed */
if (!(data && data->scan_info.external_scan))
wpa_s->own_scan_running = 0;
if (data && data->scan_info.nl_scan_event)
wpa_s->radio->external_scan_running = 0;
radio_work_check_next(wpa_s);
break;
...
}
static int wpa_supplicant_event_scan_results(struct wpa_supplicant *wpa_s,
union wpa_event_data *data)
{
struct wpa_supplicant *ifs;
int res;
res = _wpa_supplicant_event_scan_results(wpa_s, data, 1, 0);
if (res == 2) {
/*
* Interface may have been removed, so must not dereference
* wpa_s after this.
*/
return 1;
}
if (res < 0) {
/*
* If no scan results could be fetched, then no need to
* notify those interfaces that did not actually request
* this scan. Similarly, if scan results started a new operation on this
* interface, do not notify other interfaces to avoid concurrent
* operations during a connection attempt.
*/
return 0;
}
/*
* Check other interfaces to see if they share the same radio. If
* so, they get updated with this same scan info.
*/
dl_list_for_each(ifs, &wpa_s->radio->ifaces, struct wpa_supplicant,
radio_list) {
if (ifs != wpa_s) {
wpa_printf(MSG_DEBUG, "%s: Updating scan results from "
"sibling", ifs->ifname);
res = _wpa_supplicant_event_scan_results(ifs, data, 0,
res > 0);
if (res < 0)
return 0;
}
}
return 0;
}
static int _wpa_supplicant_event_scan_results(struct wpa_supplicant *wpa_s,
union wpa_event_data *data,
int own_request, int update_only)
{
struct wpa_scan_results *scan_res = NULL;
int ret = 0;
int ap = 0;
#ifndef CONFIG_NO_RANDOM_POOL
size_t i, num;
#endif /* CONFIG_NO_RANDOM_POOL */
#ifdef CONFIG_AP
if (wpa_s->ap_iface)
ap = 1;
#endif /* CONFIG_AP */
wpa_supplicant_notify_scanning(wpa_s, 0);
scan_res = wpa_supplicant_get_scan_results(wpa_s,
data ? &data->scan_info :
NULL, 1);
if (scan_res == NULL) {
if (wpa_s->conf->ap_scan == 2 || ap ||
wpa_s->scan_res_handler == scan_only_handler)
return -1;
if (!own_request)
return -1;
if (data && data->scan_info.external_scan)
return -1;
// 扫描结果为空，从新扫描
wpa_dbg(wpa_s, MSG_DEBUG, "Failed to get scan results - try "
"scanning again");
wpa_supplicant_req_new_scan(wpa_s, 1, 0);
ret = -1;
goto scan_work_done;
}
#ifndef CONFIG_NO_RANDOM_POOL
num = scan_res->num;
if (num > 10)
num = 10;
for (i = 0; i < num; i++) {
#ifdef CONFIG_WAPI
u8 buf[6];
#else
u8 buf[5];
#endif
struct wpa_scan_res *res = scan_res->res[i];
buf[0] = res->bssid[5];
buf[1] = res->qual & 0xff;
buf[2] = res->noise & 0xff;
buf[3] = res->level & 0xff;
buf[4] = res->tsf & 0xff;
#ifdef CONFIG_WAPI
buf[5] = res->wapi_ie_len & 0xff;
#endif
random_add_randomness(buf, sizeof(buf));
}
#endif /* CONFIG_NO_RANDOM_POOL */
if (update_only) {
ret = 1;
goto scan_work_done;
}
if (own_request && wpa_s->scan_res_handler &&
!(data && data->scan_info.external_scan)) {
void (*scan_res_handler)(struct wpa_supplicant *wpa_s,
struct wpa_scan_results *scan_res);
scan_res_handler = wpa_s->scan_res_handler;
wpa_s->scan_res_handler = NULL;
scan_res_handler(wpa_s, scan_res);
ret = 1;
goto scan_work_done;
}
// AP 模式忽略扫描
if (ap) {
wpa_dbg(wpa_s, MSG_DEBUG, "Ignore scan results in AP mode");
#ifdef CONFIG_AP
if (wpa_s->ap_iface->scan_cb)
wpa_s->ap_iface->scan_cb(wpa_s->ap_iface);
#endif /* CONFIG_AP */
goto scan_work_done;
}
wpa_dbg(wpa_s, MSG_DEBUG, "New scan results available (own=%u ext=%u)",
wpa_s->own_scan_running,
data ? data->scan_info.external_scan : 0);
if (wpa_s->last_scan_req == MANUAL_SCAN_REQ &&
wpa_s->manual_scan_use_id && wpa_s->own_scan_running &&
own_request && !(data && data->scan_info.external_scan)) {
wpa_msg_ctrl(wpa_s, MSG_INFO, WPA_EVENT_SCAN_RESULTS "id=%u",
wpa_s->manual_scan_id);
wpa_s->manual_scan_use_id = 0;
} else {
wpa_msg_ctrl(wpa_s, MSG_INFO, WPA_EVENT_SCAN_RESULTS);
}
wpas_notify_scan_results(wpa_s);
wpas_notify_scan_done(wpa_s, 1);
if (data && data->scan_info.external_scan) {
wpa_dbg(wpa_s, MSG_DEBUG, "Do not use results from externally requested scan operation for network selection");
wpa_scan_results_free(scan_res);
return 0;
}
if (wnm_scan_process(wpa_s, 1) > 0)
goto scan_work_done;
if (sme_proc_obss_scan(wpa_s) > 0)
goto scan_work_done;
if (own_request &&
wpas_beacon_rep_scan_process(wpa_s, scan_res, &data->scan_info) > 0)
goto scan_work_done;
if ((wpa_s->conf->ap_scan == 2 && !wpas_wps_searching(wpa_s)))
goto scan_work_done;
if (autoscan_notify_scan(wpa_s, scan_res))
goto scan_work_done;
if (wpa_s->disconnected) {
wpa_supplicant_set_state(wpa_s, WPA_DISCONNECTED);
goto scan_work_done;
}
if (!wpas_driver_bss_selection(wpa_s) &&
bgscan_notify_scan(wpa_s, scan_res) == 1)
goto scan_work_done;
wpas_wps_update_ap_info(wpa_s, scan_res);
if (wpa_s->wpa_state >= WPA_AUTHENTICATING &&
wpa_s->wpa_state < WPA_COMPLETED)
goto scan_work_done;
wpa_scan_results_free(scan_res);
if (own_request && wpa_s->scan_work) {
struct wpa_radio_work *work = wpa_s->scan_work;
wpa_s->scan_work = NULL;
radio_work_done(work);
}
return wpas_select_network_from_last_scan(wpa_s, 1, own_request);
scan_work_done:
wpa_scan_results_free(scan_res);
if (own_request && wpa_s->scan_work) {
struct wpa_radio_work *work = wpa_s->scan_work;
wpa_s->scan_work = NULL;
radio_work_done(work);
}
return ret;
}
// 这里对扫描结果进行处理，找到了就进行连接，没找到就继续扫描。
static int wpas_select_network_from_last_scan(struct wpa_supplicant *wpa_s,
int new_scan, int own_request)
{
struct wpa_bss *selected;
struct wpa_ssid *ssid = NULL;
int time_to_reenable = wpas_reenabled_network_time(wpa_s);
if (time_to_reenable > 0) {
wpa_dbg(wpa_s, MSG_DEBUG,
"Postpone network selection by %d seconds since all networks are disabled",
time_to_reenable);
eloop_cancel_timeout(wpas_network_reenabled, wpa_s, NULL);
eloop_register_timeout(time_to_reenable, 0,
wpas_network_reenabled, wpa_s, NULL);
return 0;
}
if (wpa_s->p2p_mgmt)
return 0; /* no normal connection on p2p_mgmt interface */
selected = wpa_supplicant_pick_network(wpa_s, &ssid); // 选择网络
#ifdef CONFIG_MESH
if (wpa_s->ifmsh) {
wpa_msg(wpa_s, MSG_INFO,
"Avoiding join because we already joined a mesh group");
return 0;
}
#endif /* CONFIG_MESH */
if (selected) {
int skip;
skip = !wpa_supplicant_need_to_roam(wpa_s, selected, ssid); // 是否需要漫游, 后面再分析
if (skip) {
if (new_scan)
wpa_supplicant_rsn_preauth_scan_results(wpa_s); // 快速漫游，预认证, 漫游才会用到
return 0;
}
if (ssid != wpa_s->current_ssid &&
wpa_s->wpa_state >= WPA_AUTHENTICATING) {
wpa_s->own_disconnect_req = 1;
wpa_supplicant_deauthenticate(
wpa_s, WLAN_REASON_DEAUTH_LEAVING);
}
if (wpa_supplicant_connect(wpa_s, selected, ssid) < 0) { // 连接网络
wpa_dbg(wpa_s, MSG_DEBUG, "Connect failed");
return -1;
}
if (new_scan)
wpa_supplicant_rsn_preauth_scan_results(wpa_s);
/*
* Do not allow other virtual radios to trigger operations based
* on these scan results since we do not want them to start
* other associations at the same time.
*/
return 1;
} else {
// 没找到合适的网络
wpa_dbg(wpa_s, MSG_DEBUG, "No suitable network found");
ssid = wpa_supplicant_pick_new_network(wpa_s);
if (ssid) {
wpa_dbg(wpa_s, MSG_DEBUG, "Setup a new network");
wpa_supplicant_associate(wpa_s, NULL, ssid);
if (new_scan)
wpa_supplicant_rsn_preauth_scan_results(wpa_s);
} else if (own_request) {
/*
* No SSID found. If SCAN results are as a result of
* own scan request and not due to a scan request on
* another shared interface, try another scan.
*/
int timeout_sec = wpa_s->scan_interval;
int timeout_usec = 0;
......
// 重新扫描
if (wpa_supplicant_req_sched_scan(wpa_s))
wpa_supplicant_req_new_scan(wpa_s, timeout_sec,
timeout_usec);
wpa_msg_ctrl(wpa_s, MSG_INFO,
WPA_EVENT_NETWORK_NOT_FOUND);
}
}
return 0;
}
// 选择网络
struct wpa_bss * wpa_supplicant_pick_network(struct wpa_supplicant *wpa_s,
struct wpa_ssid **selected_ssid)
{
struct wpa_bss *selected = NULL;
int prio;
struct wpa_ssid *next_ssid = NULL;
struct wpa_ssid *ssid;
if (wpa_s->last_scan_res == NULL ||
wpa_s->last_scan_res_used == 0)
return NULL; /* no scan results from last update */
if (wpa_s->next_ssid) {
/* check that next_ssid is still valid */
for (ssid = wpa_s->conf->ssid; ssid; ssid = ssid->next) {
if (ssid == wpa_s->next_ssid)
break;
}
next_ssid = ssid;
wpa_s->next_ssid = NULL;
}
while (selected == NULL) {
for (prio = 0; prio < wpa_s->conf->num_prio; prio++) {
if (next_ssid && next_ssid->priority ==
wpa_s->conf->pssid[prio]->priority) {
selected = wpa_supplicant_select_bss(// 选择网络
wpa_s, next_ssid, selected_ssid, 1);
if (selected)
break;
}
selected = wpa_supplicant_select_bss(
wpa_s, wpa_s->conf->pssid[prio],
selected_ssid, 0);
if (selected)
break;
}
if (selected == NULL && wpa_s->blacklist &&// 选择之后，没有合适的AP，清除黑名单
!wpa_s->countermeasures) {
wpa_dbg(wpa_s, MSG_DEBUG, "No APs found - clear "
"blacklist and try again");
wpa_blacklist_clear(wpa_s);
wpa_s->blacklist_cleared++;
} else if (selected == NULL)
break;
}
ssid = *selected_ssid;
if (selected && ssid && ssid->mem_only_psk && !ssid->psk_set &&
!ssid->passphrase && !ssid->ext_psk) {
const char *field_name, *txt = NULL;
wpa_dbg(wpa_s, MSG_DEBUG,
"PSK/passphrase not yet available for the selected network");
wpas_notify_network_request(wpa_s, ssid,
WPA_CTRL_REQ_PSK_PASSPHRASE, NULL);
field_name = wpa_supplicant_ctrl_req_to_string(
WPA_CTRL_REQ_PSK_PASSPHRASE, NULL, &txt);
if (field_name == NULL)
return NULL;
wpas_send_ctrl_req(wpa_s, ssid, field_name, txt);
selected = NULL;
}
return selected;
}
static struct wpa_bss *
wpa_supplicant_select_bss(struct wpa_supplicant *wpa_s,
struct wpa_ssid *group,
struct wpa_ssid **selected_ssid,
int only_first_ssid)
{
unsigned int i;
if (wpa_s->current_ssid) {
struct wpa_ssid *ssid;
wpa_dbg(wpa_s, MSG_DEBUG,
"Scan results matching the currently selected network");
for (i = 0; i < wpa_s->last_scan_res_used; i++) {
struct wpa_bss *bss = wpa_s->last_scan_res[i];
ssid = wpa_scan_res_match(wpa_s, i, bss, group,
only_first_ssid, 0);
if (ssid != wpa_s->current_ssid)
continue;
wpa_dbg(wpa_s, MSG_DEBUG, "%u: " MACSTR
" freq=%d level=%d snr=%d est_throughput=%u",
i, MAC2STR(bss->bssid), bss->freq, bss->level,
bss->snr, bss->est_throughput);
}
}
if (only_first_ssid)
wpa_dbg(wpa_s, MSG_DEBUG, "Try to find BSS matching pre-selected network id=%d",
group->id);
else
wpa_dbg(wpa_s, MSG_DEBUG, "Selecting BSS from priority group %d",
group->priority);
for (i = 0; i < wpa_s->last_scan_res_used; i++) {
struct wpa_bss *bss = wpa_s->last_scan_res[i];
*selected_ssid = wpa_scan_res_match(wpa_s, i, bss, group,// 匹配
only_first_ssid, 1);
if (!*selected_ssid)
continue;
wpa_dbg(wpa_s, MSG_DEBUG, " selected BSS " MACSTR
" ssid='%s'",
MAC2STR(bss->bssid),
wpa_ssid_txt(bss->ssid, bss->ssid_len));
return bss;
}
return NULL;
}
// 将发过来的ssid中的数据帧和配置文件中的参数进行匹配，查看是否正常
struct wpa_ssid * wpa_scan_res_match(struct wpa_supplicant *wpa_s,
int i, struct wpa_bss *bss,
struct wpa_ssid *group,
int only_first_ssid, int debug_print)
{
u8 wpa_ie_len, rsn_ie_len;
int wpa;
struct wpa_blacklist *e;
const u8 *ie;
struct wpa_ssid *ssid;
int osen;
#ifdef CONFIG_WAPI
u8 wapi_ie_len;
#endif
#ifdef CONFIG_MBO
const u8 *assoc_disallow;
#endif /* CONFIG_MBO */
// 获取vendor信息
ie = wpa_bss_get_vendor_ie(bss, WPA_IE_VENDOR_TYPE);
wpa_ie_len = ie ? ie[1] : 0;
ie = wpa_bss_get_ie(bss, WLAN_EID_RSN);
rsn_ie_len = ie ? ie[1] : 0;
ie = wpa_bss_get_vendor_ie(bss, OSEN_IE_VENDOR_TYPE);
osen = ie != NULL;
if (debug_print) {
wpa_dbg(wpa_s, MSG_DEBUG, "%d: " MACSTR
" ssid='%s' wpa_ie_len=%u rsn_ie_len=%u caps=0x%x level=%d freq=%d %s%s%s",
i, MAC2STR(bss->bssid),
wpa_ssid_txt(bss->ssid, bss->ssid_len),
wpa_ie_len, rsn_ie_len, bss->caps, bss->level,
bss->freq,
wpa_bss_get_vendor_ie(bss, WPS_IE_VENDOR_TYPE) ?
" wps" : "",
(wpa_bss_get_vendor_ie(bss, P2P_IE_VENDOR_TYPE) ||
wpa_bss_get_vendor_ie_beacon(bss, P2P_IE_VENDOR_TYPE))
? " p2p" : "",
osen ? " osen=1" : "");
}
e = wpa_blacklist_get(wpa_s, bss->bssid);
if (e) {
int limit = 1;
if (wpa_supplicant_enabled_networks(wpa_s) == 1) {
/*
* When only a single network is enabled, we can
* trigger blacklisting on the first failure. This
* should not be done with multiple enabled networks to
* avoid getting forced to move into a worse ESS on
* single error if there are no other BSSes of the
* current ESS.
*/
limit = 0;
}
if (e->count > limit) {
if (debug_print) {
wpa_dbg(wpa_s, MSG_DEBUG,
" skip - blacklisted (count=%d limit=%d)",
e->count, limit);
}
return NULL;
}
}
// 对SSID的参数进行比对，不匹配的推出
if (bss->ssid_len == 0) {
if (debug_print)
wpa_dbg(wpa_s, MSG_DEBUG, " skip - SSID not known");
return NULL;
}
if (disallowed_bssid(wpa_s, bss->bssid)) {
if (debug_print)
wpa_dbg(wpa_s, MSG_DEBUG, " skip - BSSID disallowed");
return NULL;
}
if (disallowed_ssid(wpa_s, bss->ssid, bss->ssid_len)) {
if (debug_print)
wpa_dbg(wpa_s, MSG_DEBUG, " skip - SSID disallowed");
return NULL;
}
wpa = wpa_ie_len > 0 || rsn_ie_len > 0;
......
for (ssid = group; ssid; ssid = only_first_ssid ? NULL : ssid->pnext) {
int check_ssid = wpa ? 1 : (ssid->ssid_len != 0);
int res;
if (wpas_network_disabled(wpa_s, ssid)) {
if (debug_print)
wpa_dbg(wpa_s, MSG_DEBUG, " skip - disabled");
continue;
}
res = wpas_temp_disabled(wpa_s, ssid);
if (res > 0) {
if (debug_print)
wpa_dbg(wpa_s, MSG_DEBUG,
" skip - disabled temporarily for %d second(s)",
res);
continue;
}
if (ssid->bssid_set && ssid->ssid_len == 0 &&
os_memcmp(bss->bssid, ssid->bssid, ETH_ALEN) == 0)
check_ssid = 0;
if (check_ssid &&
(bss->ssid_len != ssid->ssid_len ||
os_memcmp(bss->ssid, ssid->ssid, bss->ssid_len) != 0)) {
if (debug_print)
wpa_dbg(wpa_s, MSG_DEBUG,
" skip - SSID mismatch");
continue;
}
if (ssid->bssid_set &&
os_memcmp(bss->bssid, ssid->bssid, ETH_ALEN) != 0) {
if (debug_print)
wpa_dbg(wpa_s, MSG_DEBUG,
" skip - BSSID mismatch");
continue;
}
// 黑名单的跳过，不进行匹配
/* check blacklist */
if (ssid->num_bssid_blacklist &&
addr_in_list(bss->bssid, ssid->bssid_blacklist,
ssid->num_bssid_blacklist)) {
if (debug_print)
wpa_dbg(wpa_s, MSG_DEBUG,
" skip - BSSID blacklisted");
continue;
}
/* if there is a whitelist, only accept those APs */
if (ssid->num_bssid_whitelist &&
!addr_in_list(bss->bssid, ssid->bssid_whitelist,
ssid->num_bssid_whitelist)) {
if (debug_print)
wpa_dbg(wpa_s, MSG_DEBUG,
" skip - BSSID not in whitelist");
continue;
}
if (!wpa_supplicant_ssid_bss_match(wpa_s, ssid, bss,
debug_print))
continue;
// 判断密钥类型是否匹配
if (!osen && !wpa &&
!(ssid->key_mgmt & WPA_KEY_MGMT_NONE) &&
!(ssid->key_mgmt & WPA_KEY_MGMT_WPS) &&
#ifdef CONFIG_WAPI
!(ssid->key_mgmt & WPA_KEY_MGMT_WAPI_PSK) &&
!(ssid->key_mgmt & WPA_KEY_MGMT_WAPI_CERT) &&
#endif
!(ssid->key_mgmt & WPA_KEY_MGMT_IEEE8021X_NO_WPA)) {
if (debug_print)
wpa_dbg(wpa_s, MSG_DEBUG,
" skip - non-WPA network not allowed");
continue;
}
if (wpa && !wpa_key_mgmt_wpa(ssid->key_mgmt) &&
has_wep_key(ssid)) {
if (debug_print)
wpa_dbg(wpa_s, MSG_DEBUG,
" skip - ignore WPA/WPA2 AP for WEP network block");
continue;
}
if ((ssid->key_mgmt & WPA_KEY_MGMT_OSEN) && !osen) {
if (debug_print)
wpa_dbg(wpa_s, MSG_DEBUG,
" skip - non-OSEN network not allowed");
continue;
}
......
if (ssid->mode != IEEE80211_MODE_MESH && !bss_is_ess(bss) &&
!bss_is_pbss(bss)) {
if (debug_print)
wpa_dbg(wpa_s, MSG_DEBUG,
" skip - not ESS, PBSS, or MBSS");
continue;
}
if (ssid->pbss != 2 && ssid->pbss != bss_is_pbss(bss)) {
if (debug_print)
wpa_dbg(wpa_s, MSG_DEBUG,
" skip - PBSS mismatch (ssid %d bss %d)",
ssid->pbss, bss_is_pbss(bss));
continue;
}
if (!freq_allowed(ssid->freq_list, bss->freq)) {
if (debug_print)
wpa_dbg(wpa_s, MSG_DEBUG,
" skip - frequency not allowed");
continue;
}
......
if (!rate_match(wpa_s, bss, debug_print)) {
if (debug_print)
wpa_dbg(wpa_s, MSG_DEBUG,
" skip - rate sets do not match");
continue;
}
#ifndef CONFIG_IBSS_RSN
if (ssid->mode == WPAS_MODE_IBSS &&
!(ssid->key_mgmt & (WPA_KEY_MGMT_NONE |
WPA_KEY_MGMT_WPA_NONE))) {
if (debug_print)
wpa_dbg(wpa_s, MSG_DEBUG,
" skip - IBSS RSN not supported in the build");
continue;
}
#endif /* !CONFIG_IBSS_RSN */
......
if (os_reltime_before(&bss->last_update, &wpa_s->scan_min_time))
{
struct os_reltime diff;
os_reltime_sub(&wpa_s->scan_min_time,
&bss->last_update, &diff);
if (debug_print)
wpa_dbg(wpa_s, MSG_DEBUG,
" skip - scan result not recent enough (%u.%06u seconds too old)",
(unsigned int) diff.sec,
(unsigned int) diff.usec);
continue;
}
/* Matching configuration found */
return ssid;
}
/* No matching configuration found */
return NULL;
}
// 各种认证方式定义
external\wpa_supplicant_8\src\common\defs.h
#define WPA_KEY_MGMT_IEEE8021X BIT(0)// 802.1X认证
#define WPA_KEY_MGMT_PSK BIT(1)// psk
#define WPA_KEY_MGMT_NONE BIT(2)// 无密钥
#define WPA_KEY_MGMT_IEEE8021X_NO_WPA BIT(3)
#define WPA_KEY_MGMT_WPA_NONE BIT(4)
#define WPA_KEY_MGMT_FT_IEEE8021X BIT(5)// Fast transition + 802.1X
#define WPA_KEY_MGMT_FT_PSK BIT(6)// Fast transition
#define WPA_KEY_MGMT_IEEE8021X_SHA256 BIT(7)
#define WPA_KEY_MGMT_PSK_SHA256 BIT(8)
#define WPA_KEY_MGMT_WPS BIT(9)
#define WPA_KEY_MGMT_SAE BIT(10)
#define WPA_KEY_MGMT_FT_SAE BIT(11)
#define WPA_KEY_MGMT_WAPI_PSK BIT(12)
#define WPA_KEY_MGMT_WAPI_CERT BIT(13)
#define WPA_KEY_MGMT_CCKM BIT(14)
#define WPA_KEY_MGMT_OSEN BIT(15)
#define WPA_KEY_MGMT_IEEE8021X_SUITE_B BIT(16)
#define WPA_KEY_MGMT_IEEE8021X_SUITE_B_192 BIT(17)
#define WPA_KEY_MGMT_FILS_SHA256 BIT(18)
#define WPA_KEY_MGMT_FILS_SHA384 BIT(19)
#define WPA_KEY_MGMT_FT_FILS_SHA256 BIT(20)
#define WPA_KEY_MGMT_FT_FILS_SHA384 BIT(21)
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