[v2,2/2] wiphy: add better handling for rate estimation errors

Commit Message

James Prestwood March 28, 2024, 2:26 p.m. UTC

In most cases any failure here is likely just due to the AP not
supporting the feature, whether its HE/VHT/HE. This should result
in the estimation returning -ENOTSUP in which case we move down
the list. Any other non-zero return we will now warn to make it
clear the IEs did exist, but were not properly formatted.

All length check failures were changed to continue instead of
fail. This will now treat invalid lengths as if the IE did not
exist.

In addition HE specifically has an extra validation function which,
if failed, was bailing out of the estimation function entirely.
Instead this is now treated as if there was no HE capabilities and
the logic can move down to VHT, HT, or basic rates.
---
 src/wiphy.c | 44 ++++++++++++++++++++++++++++++--------------
 1 file changed, 30 insertions(+), 14 deletions(-)

v2:
 - Make all length checks continue instead of return

Patch

diff --git a/src/wiphy.c b/src/wiphy.c
index 0d64b1b3..712d20cf 100644
--- a/src/wiphy.c
+++ b/src/wiphy.c
@@ -989,6 +989,7 @@  int wiphy_estimate_data_rate(struct wiphy *wiphy,
 	const void *he_capabilities = NULL;
 	const struct band *bandp;
 	enum band_freq band;
+	int ret;
 
 	if (band_freq_to_channel(bss->frequency, &band) == 0)
 		return -ENOTSUP;
@@ -1005,7 +1006,7 @@  int wiphy_estimate_data_rate(struct wiphy *wiphy,
 		switch (tag) {
 		case IE_TYPE_SUPPORTED_RATES:
 			if (iter.len > 8)
-				return -EBADMSG;
+				continue;
 
 			supported_rates = iter.data - 2;
 			break;
@@ -1014,31 +1015,33 @@  int wiphy_estimate_data_rate(struct wiphy *wiphy,
 			break;
 		case IE_TYPE_HT_CAPABILITIES:
 			if (iter.len != 26)
-				return -EBADMSG;
+				continue;
 
 			ht_capabilities = iter.data - 2;
 			break;
 		case IE_TYPE_HT_OPERATION:
 			if (iter.len != 22)
-				return -EBADMSG;
+				continue;
 
 			ht_operation = iter.data - 2;
 			break;
 		case IE_TYPE_VHT_CAPABILITIES:
 			if (iter.len != 12)
-				return -EBADMSG;
+				continue;
 
 			vht_capabilities = iter.data - 2;
 			break;
 		case IE_TYPE_VHT_OPERATION:
 			if (iter.len != 5)
-				return -EBADMSG;
+				continue;
 
 			vht_operation = iter.data - 2;
 			break;
 		case IE_TYPE_HE_CAPABILITIES:
-			if (!ie_validate_he_capabilities(iter.data, iter.len))
-				return -EBADMSG;
+			if (!ie_validate_he_capabilities(iter.data, iter.len)) {
+				l_warn("invalid HE capabilities");
+				continue;
+			}
 
 			he_capabilities = iter.data;
 			break;
@@ -1047,26 +1050,39 @@  int wiphy_estimate_data_rate(struct wiphy *wiphy,
 		}
 	}
 
-	if (!band_estimate_he_rx_rate(bandp, he_capabilities,
+	ret = band_estimate_he_rx_rate(bandp, he_capabilities,
 					bss->signal_strength / 100,
-					out_data_rate))
+					out_data_rate);
+	if (!ret)
 		return 0;
+	else if (ret != -ENOTSUP)
+		l_warn("error parsing HE capabilities");
 
-	if (!band_estimate_vht_rx_rate(bandp, vht_capabilities, vht_operation,
+	ret = band_estimate_vht_rx_rate(bandp, vht_capabilities, vht_operation,
 					ht_capabilities, ht_operation,
 					bss->signal_strength / 100,
-					out_data_rate))
+					out_data_rate);
+	if (!ret)
 		return 0;
+	else if (ret != -ENOTSUP)
+		l_warn("error parsing VHT capabilities");
 
-	if (!band_estimate_ht_rx_rate(bandp, ht_capabilities, ht_operation,
+	ret = band_estimate_ht_rx_rate(bandp, ht_capabilities, ht_operation,
 					bss->signal_strength / 100,
-					out_data_rate))
+					out_data_rate);
+	if (!ret)
 		return 0;
+	else if (ret != -ENOTSUP)
+		l_warn("error parsing HT capabilities");
 
-	return band_estimate_nonht_rate(bandp, supported_rates,
+	ret = band_estimate_nonht_rate(bandp, supported_rates,
 						ext_supported_rates,
 						bss->signal_strength / 100,
 						out_data_rate);
+	if (ret != 0 && ret != -ENOTSUP)
+		l_warn("error parsing non-HT rates");
+
+	return ret;
 }
 
 bool wiphy_regdom_is_updating(struct wiphy *wiphy)