[PATCH v3 1/3] WNM: Move driver MBO transition rejection into wnm_is_bss_excluded
Benjamin Berg
benjamin at sipsolutions.net
Thu Sep 19 03:19:15 PDT 2024
From: Benjamin Berg <benjamin.berg at intel.com>
Change the logic a bit to not directly use the result of the
wpa_drv_get_bss_trans_status call and instead use the same selection
logic as usual but taking into account the driver rejections.
This changes the logic in minor ways. The main change is that this
aligns the ordering of BSSs to be identical in all cases. More
precisely, we'll select the best BSS as found by find_better_target.
Beyond that, it also means that in the case of an non-abridged BTM
request we'll also consider candidates that were found through the scan
and not in the neighbor report. In this case, the driver will not have a
chance to reject them.
Signed-off-by: Benjamin Berg <benjamin.berg at intel.com>
---
v2:
- Fix code when CONFIG_MBO is disabled
- Add tests to verify the behaviour
Signed-off-by: Benjamin Berg <benjamin.berg at intel.com>
---
src/drivers/driver_nl80211.c | 49 +++++++++++++
src/utils/os_unix.c | 2 +-
tests/hwsim/test_wnm.py | 55 ++++++++++++++
wpa_supplicant/wnm_sta.c | 137 +++++++++++++++++------------------
wpa_supplicant/wnm_sta.h | 2 +-
5 files changed, 172 insertions(+), 73 deletions(-)
diff --git a/src/drivers/driver_nl80211.c b/src/drivers/driver_nl80211.c
index 1356d325d5..e4465c6a4f 100644
--- a/src/drivers/driver_nl80211.c
+++ b/src/drivers/driver_nl80211.c
@@ -13965,6 +13965,52 @@ static int nl80211_do_acs(void *priv, struct drv_acs_params *params)
}
+#if defined(CONFIG_MBO) && defined(WPA_TRACE_BFD) && defined(CONFIG_TESTING_OPTIONS)
+static struct wpa_bss_candidate_info *
+nl80211_get_bss_transition_status(void *priv, struct wpa_bss_trans_info *params)
+{
+ struct wpa_bss_candidate_info *info;
+ int i;
+
+ /* This only exists for testing purposes, disable unless requested */
+ if (!TEST_FAIL_TAG("simulate"))
+ return NULL;
+
+ info = os_zalloc(sizeof(*info));
+ if (!info)
+ return NULL;
+
+ info->candidates = os_calloc(params->n_candidates,
+ sizeof(*info->candidates));
+ if (!info->candidates) {
+ os_free(info);
+ return NULL;
+ }
+
+ info->num = params->n_candidates;
+ for (i = 0; i < params->n_candidates; i++) {
+ char bssid_str[ETH_ALEN * 3];
+ os_memcpy(info->candidates[i].bssid,
+ ¶ms->bssid[i * ETH_ALEN], ETH_ALEN);
+
+ os_snprintf(bssid_str, sizeof(bssid_str), MACSTR,
+ MAC2STR(info->candidates[i].bssid));
+
+ if (TEST_FAIL_TAG(bssid_str)) {
+ info->candidates[i].is_accept = 0;
+ info->candidates[i].reject_reason =
+ MBO_TRANSITION_REJECT_REASON_FRAME_LOSS;
+ } else {
+ info->candidates[i].is_accept = 1;
+ info->candidates[i].reject_reason = 0;
+ }
+ }
+
+ return info;
+}
+#endif /* defined(CONFIG_MBO) && defined(WPA_TRACE_BFD) && defined(CONFIG_TESTING_OPTIONS) */
+
+
static int nl80211_write_to_file(const char *name, unsigned int val)
{
int fd, len;
@@ -14612,6 +14658,9 @@ const struct wpa_driver_ops wpa_driver_nl80211_ops = {
.nan_cancel_subscribe = nl80211_nan_cancel_subscribe,
#endif /* CONFIG_NAN_USD */
#endif /* CONFIG_DRIVER_NL80211_QCA */
+#if defined(CONFIG_MBO) && defined(WPA_TRACE_BFD) && defined(CONFIG_TESTING_OPTIONS)
+ .get_bss_transition_status = nl80211_get_bss_transition_status,
+#endif /* defined(CONFIG_MBO) && defined(WPA_TRACE_BFD) && defined(CONFIG_TESTING_OPTIONS) */
.do_acs = nl80211_do_acs,
.configure_data_frame_filters = nl80211_configure_data_frame_filters,
.get_ext_capab = nl80211_get_ext_capab,
diff --git a/src/utils/os_unix.c b/src/utils/os_unix.c
index 679f3a0dcc..cabfd87c0e 100644
--- a/src/utils/os_unix.c
+++ b/src/utils/os_unix.c
@@ -543,7 +543,7 @@ void * os_memdup(const void *src, size_t len)
struct wpa_trace_test_fail {
unsigned int fail_after;
char pattern[256];
-} wpa_trace_test_fail[5][2];
+} wpa_trace_test_fail[5][4];
int testing_test_fail(const char *tag, bool is_alloc)
{
diff --git a/tests/hwsim/test_wnm.py b/tests/hwsim/test_wnm.py
index bf4243a46a..cdb04f324d 100644
--- a/tests/hwsim/test_wnm.py
+++ b/tests/hwsim/test_wnm.py
@@ -1024,6 +1024,61 @@ def test_wnm_bss_tm(dev, apdev):
if ev is not None:
raise Exception("Unexpected scan started")
+ # The following two tests excercise the MBO target querying to the driver
+ dev[0].flush_scan_cache()
+ logger.info("BTM request with candidate list and all are valid, roams because MBO is enabled and driver rejects current")
+ with fail_test(dev[0], 1, "simulate;nl80211_get_bss_transition_status",
+ 1, apdev[0]['bssid'] + ";nl80211_get_bss_transition_status",
+ # Second time post-scan
+ 1, "simulate;nl80211_get_bss_transition_status",
+ 1, apdev[0]['bssid'] + ";nl80211_get_bss_transition_status"):
+ if "OK" not in hapd.request("BSS_TM_REQ " + addr + " pref=1 abridged=1 mbo=3:0:1 valid_int=255 neighbor=" + apdev[0]['bssid'] + ",0x0000,81,1,7,0301ff neighbor=" + apdev[1]['bssid'] + ",0x0000,115,36,7,0301ff"):
+ raise Exception("BSS_TM_REQ command failed")
+ ev = hapd.wait_event(['BSS-TM-RESP'], timeout=10)
+ if ev is None:
+ raise Exception("No BSS Transition Management Response")
+ if "status_code=0" not in ev:
+ raise Exception("BSS transition request was not accepted: " + ev)
+ if "target_bssid=" + apdev[1]['bssid'] not in ev:
+ raise Exception("Unexpected target BSS: " + ev)
+ # This scans only one frequency
+ scan_ev = dev[0].wait_event(["CTRL-EVENT-SCAN-STARTED"], timeout=0)
+ if scan_ev is None:
+ raise Exception("Expected scan started")
+ dev[0].wait_connected(timeout=15, error="No reassociation seen")
+ if apdev[1]['bssid'] not in ev:
+ raise Exception("Unexpected reassociation target: " + ev)
+ ev = dev[0].wait_event(["CTRL-EVENT-SCAN-STARTED"], timeout=0.1)
+ if ev is not None:
+ raise Exception("Unexpected scan started")
+
+ dev[0].flush_scan_cache()
+ logger.info("BTM request with candidate list forcing other AP throug disassoc imminent, driver does MBO reject, but still roams")
+ with fail_test(dev[0], 1, "simulate;nl80211_get_bss_transition_status",
+ 1, apdev[0]['bssid'] + ";nl80211_get_bss_transition_status",
+ # And a second time post-scan
+ 1, "simulate;nl80211_get_bss_transition_status",
+ 1, apdev[0]['bssid'] + ";nl80211_get_bss_transition_status"):
+ if "OK" not in hapd2.request("BSS_TM_REQ " + addr + " disassoc_imminent=1 pref=1 abridged=1 mbo=3:5:1 valid_int=255 neighbor=" + apdev[0]['bssid'] + ",0x0000,81,1,7,0301ff"):
+ raise Exception("BSS_TM_REQ command failed")
+ ev = hapd2.wait_event(['BSS-TM-RESP'], timeout=10)
+ if ev is None:
+ raise Exception("No BSS Transition Management Response")
+ if "status_code=0" not in ev:
+ raise Exception("BSS transition request was not accepted: " + ev)
+ if "target_bssid=" + apdev[0]['bssid'] not in ev:
+ raise Exception("Unexpected target BSS: " + ev)
+ # This scans only one frequency
+ scan_ev = dev[0].wait_event(["CTRL-EVENT-SCAN-STARTED"], timeout=0)
+ if scan_ev is None:
+ raise Exception("Expected scan started")
+ dev[0].wait_connected(timeout=15, error="No reassociation seen")
+ if apdev[0]['bssid'] not in ev:
+ raise Exception("Unexpected reassociation target: " + ev)
+ ev = dev[0].wait_event(["CTRL-EVENT-SCAN-STARTED"], timeout=0.1)
+ if ev is not None:
+ raise Exception("Unexpected scan started")
+
finally:
clear_regdom_state(dev, hapd, hapd2)
diff --git a/wpa_supplicant/wnm_sta.c b/wpa_supplicant/wnm_sta.c
index 662f6089e6..3638cd5433 100644
--- a/wpa_supplicant/wnm_sta.c
+++ b/wpa_supplicant/wnm_sta.c
@@ -614,38 +614,37 @@ static void wnm_parse_neighbor_report(struct wpa_supplicant *wpa_s,
}
-static void wnm_clear_acceptable(struct wpa_supplicant *wpa_s)
-{
- unsigned int i;
-
- for (i = 0; i < wpa_s->wnm_num_neighbor_report; i++)
- wpa_s->wnm_neighbor_report_elements[i].acceptable = 0;
-}
-
-#ifdef CONFIG_MBO
-static struct wpa_bss *
-get_mbo_transition_candidate(struct wpa_supplicant *wpa_s,
+static void
+fetch_drv_mbo_candidate_info(struct wpa_supplicant *wpa_s,
enum mbo_transition_reject_reason *reason)
{
- struct wpa_bss *target = NULL;
+#ifdef CONFIG_MBO
struct wpa_bss_trans_info params;
struct wpa_bss_candidate_info *info = NULL;
- struct neighbor_report *nei = wpa_s->wnm_neighbor_report_elements;
- u8 *first_candidate_bssid = NULL, *pos;
+ struct neighbor_report *nei;
+ u8 *pos;
unsigned int i;
+ if (!wpa_s->wnm_mbo_trans_reason_present)
+ return;
+
params.mbo_transition_reason = wpa_s->wnm_mbo_transition_reason;
params.n_candidates = 0;
params.bssid = os_calloc(wpa_s->wnm_num_neighbor_report, ETH_ALEN);
if (!params.bssid)
- return NULL;
+ return;
pos = params.bssid;
- for (i = 0; i < wpa_s->wnm_num_neighbor_report; nei++, i++) {
- if (nei->is_first)
- first_candidate_bssid = nei->bssid;
- if (!nei->acceptable)
+ for (i = 0; i < wpa_s->wnm_num_neighbor_report; i++) {
+ nei = &wpa_s->wnm_neighbor_report_elements[i];
+
+ nei->drv_mbo_reject = 0;
+
+ if (nei->preference_present && nei->preference == 0)
continue;
+
+ /* Should we query BSSIDs that we reject for other reasons? */
+
os_memcpy(pos, nei->bssid, ETH_ALEN);
pos += ETH_ALEN;
params.n_candidates++;
@@ -655,64 +654,37 @@ get_mbo_transition_candidate(struct wpa_supplicant *wpa_s,
goto end;
info = wpa_drv_get_bss_trans_status(wpa_s, ¶ms);
- if (!info) {
- /* If failed to get candidate BSS transition status from driver,
- * get the first acceptable candidate from wpa_supplicant.
- */
- target = wpa_bss_get_bssid(wpa_s, params.bssid);
+ if (!info)
goto end;
- }
- /* Get the first acceptable candidate from driver */
for (i = 0; i < info->num; i++) {
- if (info->candidates[i].is_accept) {
- target = wpa_bss_get_bssid(wpa_s,
- info->candidates[i].bssid);
- goto end;
- }
- }
+ int j;
- /* If Disassociation Imminent is set and driver rejects all the
- * candidate select first acceptable candidate which has
- * rssi > disassoc_imminent_rssi_threshold
- */
- if (wpa_s->wnm_mode & WNM_BSS_TM_REQ_DISASSOC_IMMINENT) {
- for (i = 0; i < info->num; i++) {
- target = wpa_bss_get_bssid(wpa_s,
- info->candidates[i].bssid);
- if (target &&
- (target->level <
- wpa_s->conf->disassoc_imminent_rssi_threshold))
+ for (j = 0; j < wpa_s->wnm_num_neighbor_report; nei++, j++) {
+ nei = &wpa_s->wnm_neighbor_report_elements[j];
+
+ if (!ether_addr_equal(info->candidates[i].bssid,
+ nei->bssid))
continue;
- goto end;
- }
- }
- /* While sending BTM reject use reason code of the first candidate
- * received in BTM request frame
- */
- if (reason) {
- for (i = 0; i < info->num; i++) {
- if (first_candidate_bssid &&
- ether_addr_equal(first_candidate_bssid,
- info->candidates[i].bssid)) {
+ nei->drv_mbo_reject = !info->candidates[i].is_accept;
+
+ /* Use the reject reason from "first" candidate */
+ if (nei->is_first && nei->drv_mbo_reject)
*reason = info->candidates[i].reject_reason;
- break;
- }
+
+ break;
}
}
- target = NULL;
-
end:
os_free(params.bssid);
if (info) {
os_free(info->candidates);
os_free(info);
}
- return target;
-}
#endif /* CONFIG_MBO */
+}
static struct wpa_bss * find_better_target(struct wpa_bss *a,
@@ -754,8 +726,6 @@ compare_scan_neighbor_results(struct wpa_supplicant *wpa_s,
wpa_printf(MSG_DEBUG, "WNM: Current BSS " MACSTR " RSSI %d",
MAC2STR(wpa_s->bssid), bss->level);
- wnm_clear_acceptable(wpa_s);
-
for (i = 0; i < wpa_s->wnm_num_neighbor_report; i++) {
struct neighbor_report *nei;
@@ -795,21 +765,12 @@ compare_scan_neighbor_results(struct wpa_supplicant *wpa_s,
continue;
}
- nei->acceptable = 1;
-
best_target = find_better_target(target, best_target);
if (target == bss)
bss_in_list = bss;
}
-#ifdef CONFIG_MBO
- if (wpa_s->wnm_mbo_trans_reason_present)
- target = get_mbo_transition_candidate(wpa_s, reason);
- else
- target = best_target;
-#else /* CONFIG_MBO */
target = best_target;
-#endif /* CONFIG_MBO */
if (!target)
return NULL;
@@ -1178,8 +1139,39 @@ int wnm_scan_process(struct wpa_supplicant *wpa_s, bool pre_scan_check)
wpa_s->wnm_transition_scan = false;
+ /* Fetch MBO transition candidate rejection information from driver */
+ fetch_drv_mbo_candidate_info(wpa_s, &reason);
+
/* Compare the Neighbor Report and scan results */
bss = compare_scan_neighbor_results(wpa_s, &reason);
+#ifdef CONFIG_MBO
+ if (!bss && wpa_s->wnm_mbo_trans_reason_present &&
+ wpa_s->wnm_mode & WNM_BSS_TM_REQ_DISASSOC_IMMINENT) {
+ int i;
+
+ /*
+ * We didn't find any candidate, the driver had a say about
+ * which targets to reject and disassociation is immiment.
+ *
+ * We should still try to roam, so retry after ignoring the
+ * driver reject for any BSS that has an RSSI better than
+ * disassoc_imminent_rssi_threshold.
+ */
+ for (i = 0; i < wpa_s->wnm_num_neighbor_report; i++) {
+ struct neighbor_report *nei;
+
+ nei = &wpa_s->wnm_neighbor_report_elements[i];
+
+ bss = wpa_bss_get_bssid(wpa_s, nei->bssid);
+
+ if (bss->level >
+ wpa_s->conf->disassoc_imminent_rssi_threshold)
+ nei->drv_mbo_reject = 0;
+ }
+
+ bss = compare_scan_neighbor_results(wpa_s, &reason);
+ }
+#endif /* CONFIG_MBO */
/*
* If this is a pre-scan check, returning 0 will trigger a scan and
@@ -2118,6 +2110,9 @@ bool wnm_is_bss_excluded(struct wpa_supplicant *wpa_s, struct wpa_bss *bss)
if (nei->preference_present && nei->preference == 0)
return true;
+ if (nei->drv_mbo_reject)
+ return true;
+
break;
}
diff --git a/wpa_supplicant/wnm_sta.h b/wpa_supplicant/wnm_sta.h
index 235a838fab..5994027a44 100644
--- a/wpa_supplicant/wnm_sta.h
+++ b/wpa_supplicant/wnm_sta.h
@@ -44,9 +44,9 @@ struct neighbor_report {
unsigned int rm_capab_present:1;
unsigned int bearing_present:1;
unsigned int bss_term_present:1;
- unsigned int acceptable:1;
#ifdef CONFIG_MBO
unsigned int is_first:1;
+ unsigned int drv_mbo_reject:1;
#endif /* CONFIG_MBO */
struct measurement_pilot *meas_pilot;
struct multiple_bssid *mul_bssid;
--
2.46.0
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