1 /// Error when decoding the IPv4 part of a message.
2 #[derive(Clone, Debug, Eq, PartialEq, Hash)]
3 pub enum HeaderError {
4     /// Error when the IPv4 header version field is not equal to 4.
5     UnexpectedVersion {
6         /// The unexpected version number in the IPv4 header.
7         version_number: u8,
8     },
9 
10     /// Error when the ipv4 internet header length is smaller then the header itself (5).
11     HeaderLengthSmallerThanHeader {
12         /// The internet header length that was too small.
13         ihl: u8,
14     },
15 }
16 
17 impl core::fmt::Display for HeaderError {
fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result18     fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
19         use HeaderError::*;
20         match self {
21             UnexpectedVersion { version_number } => write!(f, "IPv4 Header Error: Encountered '{}' as IP version number in the IPv4 header (must be '4' in an IPv4 header).", version_number),
22             HeaderLengthSmallerThanHeader { ihl } => write!(f, "IPv4 Header Error: The 'internet header length' value '{}' present in the IPv4 header is smaller than the minimum size of an IPv4 header. The minimum allowed value is '5'.", ihl),
23         }
24     }
25 }
26 
27 #[cfg(feature = "std")]
28 #[cfg_attr(docsrs, doc(cfg(feature = "std")))]
29 impl std::error::Error for HeaderError {
source(&self) -> Option<&(dyn std::error::Error + 'static)>30     fn source(&self) -> Option<&(dyn std::error::Error + 'static)> {
31         None
32     }
33 }
34 
35 #[cfg(test)]
36 mod tests {
37     use super::{HeaderError::*, *};
38     use alloc::format;
39     use std::{
40         collections::hash_map::DefaultHasher,
41         error::Error,
42         hash::{Hash, Hasher},
43     };
44 
45     #[test]
debug()46     fn debug() {
47         assert_eq!(
48             "UnexpectedVersion { version_number: 6 }",
49             format!("{:?}", UnexpectedVersion { version_number: 6 })
50         );
51     }
52 
53     #[test]
clone_eq_hash()54     fn clone_eq_hash() {
55         let err = HeaderError::UnexpectedVersion { version_number: 6 };
56         assert_eq!(err, err.clone());
57         let hash_a = {
58             let mut hasher = DefaultHasher::new();
59             err.hash(&mut hasher);
60             hasher.finish()
61         };
62         let hash_b = {
63             let mut hasher = DefaultHasher::new();
64             err.clone().hash(&mut hasher);
65             hasher.finish()
66         };
67         assert_eq!(hash_a, hash_b);
68     }
69 
70     #[test]
fmt()71     fn fmt() {
72         assert_eq!(
73             "IPv4 Header Error: Encountered '1' as IP version number in the IPv4 header (must be '4' in an IPv4 header).",
74             format!("{}", UnexpectedVersion{ version_number: 1 })
75         );
76         assert_eq!(
77             "IPv4 Header Error: The 'internet header length' value '2' present in the IPv4 header is smaller than the minimum size of an IPv4 header. The minimum allowed value is '5'.",
78             format!("{}", HeaderLengthSmallerThanHeader{ ihl: 2 })
79         );
80     }
81 
82     #[cfg(feature = "std")]
83     #[test]
source()84     fn source() {
85         let values = [
86             UnexpectedVersion { version_number: 0 },
87             HeaderLengthSmallerThanHeader { ihl: 0 },
88         ];
89         for v in values {
90             assert!(v.source().is_none());
91         }
92     }
93 }
94