Fix emit inconsitencies and add tests

Author: Sh3Rm4n

src/element.rs

@@ -172,11 +172,11 @@ impl Emitable for Nl80211Element {
                     v.as_slice().iter().map(|v| u8::from(*v)).collect();
                 payload.copy_from_slice(raw.as_slice());
             }
-            Self::Channel(v) => buffer[0] = *v,
-            Self::Country(v) => v.emit(buffer),
-            Self::Rsn(v) => v.emit(buffer),
-            Self::Vendor(v) => buffer[..v.len()].copy_from_slice(v.as_slice()),
-            Self::HtCapability(v) => v.emit(buffer),
+            Self::Channel(v) => payload[0] = *v,
+            Self::Country(v) => v.emit(payload),
+            Self::Rsn(v) => v.emit(payload),
+            Self::Vendor(v) => payload[..v.len()].copy_from_slice(v.as_slice()),
+            Self::HtCapability(v) => v.emit(payload),
             Self::Other(_, data) => {
                 payload.copy_from_slice(data.as_slice());
             }
@@ -193,9 +193,10 @@ const BSS_MEMBERSHIP_SELECTOR_HT_PHY: u8 = 127;
 #[derive(Debug, PartialEq, Eq, Clone, Copy)]
 #[non_exhaustive]
 pub enum Nl80211RateAndSelector {
-    /// BSS basic rate set in Mb/s.
+    /// BSS basic rate in units of 500 kb/s, if necessary rounded up to the
+    /// next 500 kbs.
     BssBasicRateSet(u8),
-    /// Rate in Mb/s.
+    /// Rate in units of 500 kb/s, if necessary rounded up to the next 500 kbs.
     Rate(u8),
     SelectorHt,
     SelectorVht,
@@ -216,43 +217,45 @@ pub enum Nl80211RateAndSelector {
 
 impl From<u8> for Nl80211RateAndSelector {
     fn from(d: u8) -> Self {
-        let msb: bool = (d & 1 << 7) > 0;
-        let value = d & 0b01111111;
+        const MSB_MASK: u8 = 0b1000_0000;
+        let msb: bool = (d & MSB_MASK) == MSB_MASK;
+        let value = d & !MSB_MASK;
         if msb {
             match value {
                 BSS_MEMBERSHIP_SELECTOR_SAE_HASH => Self::SelectorSaeHash,
                 BSS_MEMBERSHIP_SELECTOR_EPD => Self::SelectorEpd,
                 BSS_MEMBERSHIP_SELECTOR_GLK => Self::SelectorGlk,
                 BSS_MEMBERSHIP_SELECTOR_VHT_PHY => Self::SelectorVht,
                 BSS_MEMBERSHIP_SELECTOR_HT_PHY => Self::SelectorHt,
-                _ => Self::BssBasicRateSet(value / 2),
+                _ => Self::BssBasicRateSet(value),
             }
         } else {
-            Self::Rate(value / 2)
+            Self::Rate(value)
         }
     }
 }
 
 impl From<Nl80211RateAndSelector> for u8 {
     fn from(v: Nl80211RateAndSelector) -> u8 {
+        const MSB: u8 = 0b1000_0000;
         match v {
-            Nl80211RateAndSelector::BssBasicRateSet(r) => (r * 2) & 1 << 7,
+            Nl80211RateAndSelector::BssBasicRateSet(r) => r & !MSB | MSB,
             Nl80211RateAndSelector::SelectorHt => {
-                BSS_MEMBERSHIP_SELECTOR_HT_PHY & 1 << 7
+                BSS_MEMBERSHIP_SELECTOR_HT_PHY | MSB
             }
             Nl80211RateAndSelector::SelectorVht => {
-                BSS_MEMBERSHIP_SELECTOR_VHT_PHY & 1 << 7
+                BSS_MEMBERSHIP_SELECTOR_VHT_PHY | MSB
             }
             Nl80211RateAndSelector::SelectorGlk => {
-                BSS_MEMBERSHIP_SELECTOR_GLK & 1 << 7
+                BSS_MEMBERSHIP_SELECTOR_GLK | MSB
             }
             Nl80211RateAndSelector::SelectorEpd => {
-                BSS_MEMBERSHIP_SELECTOR_EPD & 1 << 7
+                BSS_MEMBERSHIP_SELECTOR_EPD | MSB
             }
             Nl80211RateAndSelector::SelectorSaeHash => {
-                BSS_MEMBERSHIP_SELECTOR_SAE_HASH & 1 << 7
+                BSS_MEMBERSHIP_SELECTOR_SAE_HASH | MSB
             }
-            Nl80211RateAndSelector::Rate(r) => r * 2,
+            Nl80211RateAndSelector::Rate(r) => r,
         }
     }
 }
@@ -312,7 +315,7 @@ impl Emitable for Nl80211ElementCountry {
             buffer[0] = self.country.as_bytes()[0];
             buffer[1] = self.country.as_bytes()[1];
         }
-        buffer[3] = self.environment.into();
+        buffer[2] = self.environment.into();
         for (i, triplet) in self.triplets.as_slice().iter().enumerate() {
             triplet.emit(&mut buffer[(i + 1) * 3..(i + 2) * 3]);
         }
@@ -991,3 +994,46 @@ impl Nl80211Pmkid {
         }
     }
 }
+
+#[cfg(test)]
+mod test {
+    use super::*;
+    use crate::macros::test::roundtrip_emit_parse_test;
+
+    roundtrip_emit_parse_test!(
+        ssid,
+        Nl80211Element,
+        Nl80211Element::Ssid("test-ssid".to_owned()),
+    );
+    roundtrip_emit_parse_test!(
+        rates_and_selectors,
+        Nl80211Element,
+        Nl80211Element::SupportedRatesAndSelectors(vec![
+            Nl80211RateAndSelector::BssBasicRateSet(1),
+            Nl80211RateAndSelector::Rate(1),
+            Nl80211RateAndSelector::SelectorHt,
+            Nl80211RateAndSelector::SelectorVht,
+            Nl80211RateAndSelector::SelectorGlk,
+        ])
+    );
+    roundtrip_emit_parse_test!(
+        channel,
+        Nl80211Element,
+        Nl80211Element::Channel(7)
+    );
+    roundtrip_emit_parse_test!(
+        country,
+        Nl80211Element,
+        Nl80211Element::Country(Nl80211ElementCountry {
+            country: "DE".to_owned(),
+            environment: Nl80211ElementCountryEnvironment::IndoorAndOutdoor,
+            triplets: vec![Nl80211ElementCountryTriplet::Subband(
+                Nl80211ElementSubBand {
+                    channel_start: 1,
+                    channel_count: 13,
+                    max_power_level: 20,
+                }
+            )],
+        }),
+    );
+}

src/macros.rs

@@ -30,3 +30,42 @@ macro_rules! try_nl80211 {
         }
     }};
 }
+
+#[cfg(test)]
+pub(crate) mod test {
+    #[macro_export]
+    macro_rules! roundtrip_emit_parse_test {
+        ($name:ident, $ty:ty, $new:expr$(,)?) => {
+            #[test]
+            fn $name() {
+                let val: $ty = $new;
+
+                // to check if the type can be emitted to a buffer greater than
+                // the needed size
+                let mut buffer = vec![0; val.buffer_len() + 1];
+                val.emit(buffer.as_mut_slice());
+
+                assert_eq!(
+                    <$ty>::parse(&buffer[0..val.buffer_len()]).unwrap(),
+                    val,
+                );
+            }
+        };
+    }
+
+    macro_rules! roundtrip_from_test {
+        ($name:ident, $from:ty => $into:ty, $new:expr$(,)?) => {
+            #[test]
+            fn $name() {
+                let val: $from = $new;
+
+                let into: $into = val.into();
+
+                assert_eq!(<$from>::from(into), val,);
+            }
+        };
+    }
+
+    pub(crate) use roundtrip_emit_parse_test;
+    pub(crate) use roundtrip_from_test;
+}

src/wifi4.rs

@@ -124,7 +124,7 @@ impl Emitable for Nl80211HtCaps {
     }
 
     fn emit(&self, buffer: &mut [u8]) {
-        buffer.copy_from_slice(&self.bits().to_ne_bytes())
+        buffer[0..self.buffer_len()].copy_from_slice(&self.bits().to_ne_bytes())
     }
 }
 
@@ -470,9 +470,9 @@ impl From<Nl80211HtExtendedCap> for [u8; 2] {
     fn from(v: Nl80211HtExtendedCap) -> [u8; 2] {
         [
             v.pco as u8 | (v.pco_trans_time << 1) | (v.mcs_feedback & 0b1) << 7,
-            ((v.mcs_feedback & 0b10) >> 1)
-                | ((v.support_ht_control as u8) << 1)
-                | ((v.rd_responder as u8) << 2),
+            (v.mcs_feedback & 0b11)
+                | ((v.support_ht_control as u8) << 2)
+                | ((v.rd_responder as u8) << 3),
         ]
     }
 }
@@ -627,7 +627,7 @@ impl Emitable for Nl80211HtTransmitBeamformingCaps {
     }
 
     fn emit(&self, buffer: &mut [u8]) {
-        buffer.copy_from_slice(&self.bits().to_ne_bytes())
+        buffer[0..self.buffer_len()].copy_from_slice(&self.bits().to_ne_bytes())
     }
 }
 
@@ -675,6 +675,94 @@ impl Emitable for Nl80211HtAselCaps {
     }
 
     fn emit(&self, buffer: &mut [u8]) {
-        buffer.copy_from_slice(&self.bits().to_ne_bytes())
-    }
+        buffer[0..self.buffer_len()].copy_from_slice(&self.bits().to_ne_bytes())
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+    use crate::macros::test::{roundtrip_emit_parse_test, roundtrip_from_test};
+
+    roundtrip_emit_parse_test!(caps, Nl80211HtCaps, Nl80211HtCaps::all());
+    roundtrip_emit_parse_test!(
+        asel_caps,
+        Nl80211HtAselCaps,
+        Nl80211HtAselCaps::all()
+    );
+    roundtrip_emit_parse_test!(
+        transmit_beamforming_cap,
+        Nl80211HtTransmitBeamformingCaps,
+        Nl80211HtTransmitBeamformingCaps::all(),
+    );
+
+    roundtrip_from_test!(tx_params, Nl80211HtTxParameter => u8, Nl80211HtTxParameter {
+        mcs_set_defined: false,
+        tx_rx_mcs_set_not_equal: false,
+        max_spatial_streams: 1,
+        unequal_modulation_supported: false,
+    });
+
+    roundtrip_from_test!(ht_wiphy_no_ht, Nl80211HtWiphyChannelType => u32, Nl80211HtWiphyChannelType::NoHt);
+    roundtrip_from_test!(ht_wiphy_ht_20, Nl80211HtWiphyChannelType => u32, Nl80211HtWiphyChannelType::Ht20);
+    roundtrip_from_test!(ht_wiphy_other, Nl80211HtWiphyChannelType => u32, Nl80211HtWiphyChannelType::Other(NL80211_CHAN_HT40PLUS + 1));
+
+    roundtrip_emit_parse_test!(
+        mcs_info,
+        Nl80211HtMcsInfo,
+        Nl80211HtMcsInfo {
+            rx_mask: [0xA5; IEEE80211_HT_MCS_MASK_LEN],
+            rx_highest: u16::MAX,
+            tx_params: Nl80211HtTxParameter {
+                mcs_set_defined: false,
+                tx_rx_mcs_set_not_equal: false,
+                max_spatial_streams: 1,
+                unequal_modulation_supported: false,
+            },
+        },
+    );
+
+    roundtrip_from_test!(a_mpdu_para, Nl80211HtAMpduPara => u8, Nl80211HtAMpduPara {
+        max_len_exponent: u8::MAX & 0b11,
+        min_space: u8::MAX & 0b111,
+    });
+
+    roundtrip_from_test!(extend_cap, Nl80211HtExtendedCap => [u8; 2], Nl80211HtExtendedCap {
+        pco: true,
+        pco_trans_time: 1,
+        mcs_feedback: 1,
+        support_ht_control: true,
+        rd_responder: true,
+    });
+
+    roundtrip_emit_parse_test!(
+        cap_mask,
+        Nl80211ElementHtCap,
+        Nl80211ElementHtCap {
+            caps: Nl80211HtCaps::all(),
+            a_mpdu_para: Nl80211HtAMpduPara {
+                max_len_exponent: 3,
+                min_space: 7,
+            },
+            mcs_set: Nl80211HtMcsInfo {
+                rx_mask: [0xA5; IEEE80211_HT_MCS_MASK_LEN],
+                rx_highest: u16::MAX,
+                tx_params: Nl80211HtTxParameter {
+                    mcs_set_defined: false,
+                    tx_rx_mcs_set_not_equal: false,
+                    max_spatial_streams: 1,
+                    unequal_modulation_supported: false,
+                },
+            },
+            ht_ext_cap: Nl80211HtExtendedCap {
+                pco: true,
+                pco_trans_time: 2,
+                mcs_feedback: 2,
+                support_ht_control: true,
+                rd_responder: true,
+            },
+            transmit_beamforming_cap: Nl80211HtTransmitBeamformingCaps::all(),
+            asel_cap: Nl80211HtAselCaps::all(),
+        },
+    );
 }