add(fuzz): add fuzzing for parsing frames

We can now fuzz frame parsing. This already caught multiple panics,
which are also fixed in this commit.

TODO: add fuzzing for emitting frames.

.gitignore

@@ -1,2 +1,3 @@
 /target
 /Cargo.lock
+dot15d4-fuzz/out

Cargo.toml

@@ -2,4 +2,4 @@
 
 resolver = "2"
 
-members = ["dot15d4", "dot15d4-macros"]
+members = ["dot15d4", "dot15d4-fuzz", "dot15d4-macros"]

dot15d4-fuzz/Cargo.toml

@@ -0,0 +1,10 @@
+[package]
+name = "dot15d4-fuzz"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+afl = "0.15.3"
+dot15d4 = { path = "../dot15d4" }

dot15d4-fuzz/in/ack

@@ -0,0 +1 @@
+022e37cdab0200020002000200020fe18f

dot15d4-fuzz/in/data1

@@ -0,0 +1 @@
+41c846efbeffff06000000000000007a3b3a1a9b0124181ef0070008f00000fe800000000000000200000000000001040e00080c0a000001000000001e003c

dot15d4-fuzz/in/data2

@@ -0,0 +1 @@
+41d801cdabffffffd9b514004b12002b

dot15d4-fuzz/in/enhanced-beacon

@@ -0,0 +1 @@
+40ebcdabffff0100010001000100003f1188061a0e0000000000011c0001c800011b00

dot15d4-fuzz/src/main.rs

@@ -0,0 +1,10 @@
+use afl::*;
+use dot15d4::frame::{Frame, FrameRepr};
+
+fn main() {
+    fuzz!(|data: &[u8]| {
+        if let Ok(frame) = Frame::new(data) {
+            let _ = FrameRepr::parse(&frame);
+        }
+    });
+}

dot15d4/src/frame/addressing.rs

@@ -3,6 +3,7 @@
 use super::FrameControl;
 use super::FrameControlRepr;
 use super::FrameVersion;
+use super::{Error, Result};
 
 /// An IEEE 802.15.4 address.
 #[derive(Debug, PartialEq, Eq, Clone, Copy)]
@@ -135,10 +136,45 @@ pub struct AddressingFields<T: AsRef<[u8]>> {
 }
 
 impl<T: AsRef<[u8]>> AddressingFields<T> {
-    pub fn new(buffer: T) -> Self {
-        Self::new_unchecked(buffer)
+    /// Create a new [`AddressingFields`] reader/writer from a given buffer.
+    ///
+    /// # Errors
+    ///
+    /// This function will check the length of the buffer to ensure it is large enough to contain
+    /// the addressing fields. If the buffer is too small, an error will be returned.
+    pub fn new(buffer: T, fc: &FrameControl<T>) -> Result<Self> {
+        let af = Self::new_unchecked(buffer);
+
+        if !af.check_len(fc) {
+            return Err(Error);
+        }
+
+        Ok(af)
     }
 
+    /// Check if the buffer is large enough to contain the addressing fields.
+    fn check_len(&self, fc: &FrameControl<T>) -> bool {
+        let Some((dst_pan_id_present, dst_addr_mode, src_pan_id_present, src_addr_mode)) = self
+            .address_present_flags(
+                fc.frame_version(),
+                fc.dst_addressing_mode(),
+                fc.src_addressing_mode(),
+                fc.pan_id_compression(),
+            )
+        else {
+            return false;
+        };
+
+        let expected_len = (if dst_pan_id_present { 2 } else { 0 })
+            + dst_addr_mode.size()
+            + (if src_pan_id_present { 2 } else { 0 })
+            + src_addr_mode.size();
+
+        self.buffer.as_ref().len() >= expected_len
+    }
+
+    /// Create a new [`AddressingFields`] reader/writer from a given buffer without checking the
+    /// length.
     pub fn new_unchecked(buffer: T) -> Self {
         Self { buffer }
     }
@@ -166,14 +202,13 @@ impl<T: AsRef<[u8]>> AddressingFields<T> {
 
     fn address_present_flags(
         &self,
-        fc: &FrameControl<T>,
+        frame_version: FrameVersion,
+        dst_addr_mode: AddressingMode,
+        src_addr_mode: AddressingMode,
+        pan_id_compression: bool,
     ) -> Option<(bool, AddressingMode, bool, AddressingMode)> {
-        let dst_addr_mode = fc.dst_addressing_mode();
-        let src_addr_mode = fc.src_addressing_mode();
-        let pan_id_compression = fc.pan_id_compression();
-
         use AddressingMode::*;
-        match fc.frame_version() {
+        match frame_version {
             FrameVersion::Ieee802154_2003 | FrameVersion::Ieee802154_2006 => {
                 match (dst_addr_mode, src_addr_mode) {
                     (Absent, src) => Some((false, Absent, true, src)),
@@ -209,7 +244,12 @@ impl<T: AsRef<[u8]>> AddressingFields<T> {
 
     /// Return the IEEE 802.15.4 destination [`Address`] if not absent.
     pub fn dst_address(&self, fc: &FrameControl<T>) -> Option<Address> {
-        if let Some((dst_pan_id, dst_addr, _, _)) = self.address_present_flags(fc) {
+        if let Some((dst_pan_id, dst_addr, _, _)) = self.address_present_flags(
+            fc.frame_version(),
+            fc.dst_addressing_mode(),
+            fc.src_addressing_mode(),
+            fc.pan_id_compression(),
+        ) {
             let offset = if dst_pan_id { 2 } else { 0 };
 
             match dst_addr {
@@ -235,7 +275,12 @@ impl<T: AsRef<[u8]>> AddressingFields<T> {
 
     /// Return the IEEE 802.15.4 source [`Address`] if not absent.
     pub fn src_address(&self, fc: &FrameControl<T>) -> Option<Address> {
-        if let Some((dst_pan_id, dst_addr, src_pan_id, src_addr)) = self.address_present_flags(fc) {
+        if let Some((dst_pan_id, dst_addr, src_pan_id, src_addr)) = self.address_present_flags(
+            fc.frame_version(),
+            fc.dst_addressing_mode(),
+            fc.src_addressing_mode(),
+            fc.pan_id_compression(),
+        ) {
             let mut offset = if dst_pan_id { 2 } else { 0 };
             offset += dst_addr.size();
             offset += if src_pan_id { 2 } else { 0 };
@@ -263,7 +308,12 @@ impl<T: AsRef<[u8]>> AddressingFields<T> {
 
     /// Return the IEEE 802.15.4 destination PAN ID if not elided.
     pub fn dst_pan_id(&self, fc: &FrameControl<T>) -> Option<u16> {
-        if let Some((true, _, _, _)) = self.address_present_flags(fc) {
+        if let Some((true, _, _, _)) = self.address_present_flags(
+            fc.frame_version(),
+            fc.dst_addressing_mode(),
+            fc.src_addressing_mode(),
+            fc.pan_id_compression(),
+        ) {
             let b = &self.buffer.as_ref()[..2];
             Some(u16::from_le_bytes([b[0], b[1]]))
         } else {
@@ -273,7 +323,12 @@ impl<T: AsRef<[u8]>> AddressingFields<T> {
 
     /// Return the IEEE 802.15.4 source PAN ID if not elided.
     pub fn src_pan_id(&self, fc: &FrameControl<T>) -> Option<u16> {
-        if let Some((dst_pan_id, dst_addr, true, _)) = self.address_present_flags(fc) {
+        if let Some((dst_pan_id, dst_addr, true, _)) = self.address_present_flags(
+            fc.frame_version(),
+            fc.dst_addressing_mode(),
+            fc.src_addressing_mode(),
+            fc.pan_id_compression(),
+        ) {
             let mut offset = if dst_pan_id { 2 } else { 0 };
             offset += dst_addr.size();
 

dot15d4/src/frame/frame_control.rs

@@ -1,6 +1,7 @@
 //! IEEE 802.15.4 Frame Control field readers and writers.
 
 use super::AddressingMode;
+use super::{Error, Result};
 
 /// IEEE 802.15.4 frame type.
 #[derive(Debug, Eq, PartialEq, Clone, Copy)]
@@ -56,7 +57,28 @@ pub struct FrameControl<T: AsRef<[u8]>> {
 }
 
 impl<T: AsRef<[u8]>> FrameControl<T> {
-    pub fn new(buffer: T) -> Self {
+    /// Create a new [`FrameControl`] reader/writer from a given buffer.
+    ///
+    /// # Errors
+    ///
+    /// Returns an error if the buffer is too short.
+    pub fn new(buffer: T) -> Result<Self> {
+        let fc = Self::new_unchecked(buffer);
+
+        if !fc.check_len() {
+            return Err(Error);
+        }
+
+        Ok(fc)
+    }
+
+    /// Returns `false` if the buffer is too short to contain the Frame Control field.
+    fn check_len(&self) -> bool {
+        self.buffer.as_ref().len() >= 2
+    }
+
+    /// Create a new [`FrameControl`] reader/writer from a given buffer without length checking.
+    pub fn new_unchecked(buffer: T) -> Self {
         Self { buffer }
     }
 

dot15d4/src/frame/ie/headers.rs

@@ -1,5 +1,6 @@
 //! IEEE 802.15.4 Header Information Element reader and writers.
 
+use crate::frame::{Error, Result};
 use crate::time::Duration;
 use dot15d4_macros::frame;
 
@@ -10,10 +11,27 @@ pub struct HeaderInformationElement<T: AsRef<[u8]>> {
 }
 
 impl<T: AsRef<[u8]>> HeaderInformationElement<T> {
-    pub fn new(data: T) -> Self {
-        Self::new_unchecked(data)
+    /// Create a new [`HeaderInformationElement`] reader/writer from a given buffer.
+    ///
+    /// # Errors
+    ///
+    /// Returns an error if the length field is less than 2.
+    pub fn new(data: T) -> Result<Self> {
+        let ie = Self::new_unchecked(data);
+
+        if !ie.check_len() {
+            return Err(Error);
+        }
+
+        Ok(ie)
     }
 
+    /// Returns `false` if the buffer is too short to contain the Header Information Element.
+    fn check_len(&self) -> bool {
+        self.data.as_ref().len() >= 2
+    }
+
+    /// Create a new [`HeaderInformationElement`] reader/writer from a given buffer without length checking.
     pub fn new_unchecked(data: T) -> Self {
         Self { data }
     }
@@ -92,7 +110,10 @@ impl<T: AsRef<[u8]>> core::fmt::Display for HeaderInformationElement<T> {
                 )
             }
             HeaderElementId::TimeCorrection => {
-                write!(f, "{} {}", id, TimeCorrection::new(self.content()))
+                let Ok(tc) = TimeCorrection::new(self.content()) else {
+                    return write!(f, "{:?}({:0x?})", id, self.content());
+                };
+                write!(f, "{} {}", id, tc)
             }
             id => write!(f, "{:?}({:0x?})", id, self.content()),
         }
@@ -180,9 +201,7 @@ impl<'f> Iterator for HeaderInformationElementsIterator<'f> {
         if self.terminated {
             None
         } else {
-            let ie = HeaderInformationElement {
-                data: &self.data[self.offset..],
-            };
+            let ie = HeaderInformationElement::new(&self.data[self.offset..]).ok()?;
 
             self.terminated = matches!(
                 ie.element_id(),
@@ -292,10 +311,27 @@ pub struct TimeCorrection<T: AsRef<[u8]>> {
 }
 
 impl<T: AsRef<[u8]>> TimeCorrection<T> {
-    pub fn new(buffer: T) -> Self {
-        Self { buffer }
+    /// Create a new [`TimeCorrection`] reader/writer from a given buffer.
+    /// 
+    /// # Errors
+    ///
+    /// Returns an error if the buffer is too short.
+    pub fn new(buffer: T) -> Result<Self> {
+        let ie = Self::new_unchecked(buffer);
+
+        if !ie.check_len() {
+            return Err(Error);
+        }
+
+        Ok(ie)
+    }
+
+    /// Returns `false` if the buffer is too short to contain the Time Correction field.
+    fn check_len(&self) -> bool {
+        self.buffer.as_ref().len() >= 2
     }
 
+    /// Create a new [`TimeCorrection`] reader/writer from a given buffer without length checking.
     pub fn new_unchecked(buffer: T) -> Self {
         Self { buffer }
     }

dot15d4/src/frame/ie/mod.rs

@@ -9,6 +9,8 @@ pub use payloads::*;
 mod nested;
 pub use nested::*;
 
+use super::{Error, Result};
+
 use heapless::Vec;
 
 /// IEEE 802.15.4 Information Element reader.
@@ -17,10 +19,41 @@ pub struct InformationElements<T: AsRef<[u8]>> {
 }
 
 impl<T: AsRef<[u8]>> InformationElements<T> {
-    pub fn new(data: T) -> Self {
-        Self::new_unchecked(data)
+    /// Create a new [`InformationElements`] reader from a given buffer.
+    ///
+    /// # Errors
+    ///
+    /// Returns an error if the buffer is too short to contain the information elements.
+    pub fn new(data: T) -> Result<Self> {
+        let ie = Self::new_unchecked(data);
+
+        if !ie.check_len() {
+            return Err(Error);
+        }
+
+        Ok(ie)
+    }
+
+    /// Returns `false` if the buffer is too short to contain the information elements.
+    fn check_len(&self) -> bool {
+        let mut len = 0;
+
+        let mut iter = self.header_information_elements();
+        while iter.next().is_some() {}
+        len += iter.offset();
+
+        if len > self.data.as_ref().len() {
+            return false;
+        }
+
+        let mut iter = self.payload_information_elements();
+        while iter.next().is_some() {}
+        len += iter.offset();
+
+        self.data.as_ref().len() >= len
     }
 
+    /// Create a new [`InformationElements`] reader from a given buffer without length checking.
     pub fn new_unchecked(data: T) -> Self {
         Self { data }
     }