From df255f926715adb56439e60b116ee4e64cecae25 Mon Sep 17 00:00:00 2001
From: ddidderr <ddidderr@paul.network>
Date: Sun, 8 May 2022 16:48:15 +0200
Subject: [PATCH] (tests) rcode parsing tests (#22)

Check if valid and invalid response codes are parsed correctly.

Reviewed-on: https://git.comff.net/rustics/dns/pulls/22
Co-authored-by: ddidderr <ddidderr@paul.network>
Co-committed-by: ddidderr <ddidderr@paul.network>
---
 src/proto.rs | 84 +++++++++++++++++++++++++++++++++++++++++++---------
 1 file changed, 70 insertions(+), 14 deletions(-)

diff --git a/src/proto.rs b/src/proto.rs
index 7680a7e..c26d676 100644
--- a/src/proto.rs
+++ b/src/proto.rs
@@ -74,7 +74,7 @@ impl TryFrom<u8> for DNSOpCode {
 ///
 /// 65,535
 /// 0xFFFF              Reserved; can only be allocated by Standards Action.
-#[derive(Debug)]
+#[derive(Debug, PartialEq, Copy, Clone)]
 pub enum DNSRCode {
     NoError = 0,
     FormErr = 1,
@@ -110,7 +110,7 @@ impl TryFrom<u8> for DNSRCode {
     }
 }
 
-#[derive(Debug, PartialEq)]
+#[derive(Debug, PartialEq, Clone, Copy)]
 pub enum DNSMessageType {
     Query,
     Response,
@@ -125,7 +125,7 @@ impl From<bool> for DNSMessageType {
     }
 }
 
-#[derive(Debug)]
+#[derive(Debug, Clone, PartialEq)]
 pub struct DNSHeader {
     /// used by the requester to match up replies to outstanding queries
     pub id: u16,
@@ -155,7 +155,7 @@ pub struct DNSHeader {
     pub additional_count: u16,
 }
 
-#[derive(Debug)]
+#[derive(Debug, Clone)]
 pub struct DNSQuery {
     pub hdr: DNSHeader,
     pub name: String,
@@ -219,7 +219,7 @@ impl DNSHeader {
     }
 }
 
-#[derive(Debug, PartialEq)]
+#[derive(Debug, Clone, PartialEq)]
 pub enum DNSParseError {
     DatagramTooShort,
     DNSOpCodeInvalid,
@@ -228,7 +228,9 @@ pub enum DNSParseError {
 
 #[cfg(test)]
 mod tests {
+
     use super::*;
+
     #[test]
     fn parse_dns_header_too_short() {
         // minimal header with 1 byte missing
@@ -264,20 +266,19 @@ mod tests {
         let mut dns_query = [
             0xff, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
         ];
-        let valid_opcodes = [0, 1, 2, 4, 5];
-        let valid_parsed_opcodes = [
-            DNSOpCode::Query,
-            DNSOpCode::IQuery,
-            DNSOpCode::Status,
-            DNSOpCode::Notify,
-            DNSOpCode::Update,
+        let valid_opcodes = [
+            (0, DNSOpCode::Query),
+            (1, DNSOpCode::IQuery),
+            (2, DNSOpCode::Status),
+            (4, DNSOpCode::Notify),
+            (5, DNSOpCode::Update),
         ];
 
-        for (idx, opcode) in valid_opcodes.iter().enumerate() {
+        for (opcode, parsed_opcode) in valid_opcodes {
             dns_query[2] = opcode << 3;
             let parse_result = DNSHeader::from_udp_datagram(&dns_query);
             assert_eq!(
-                parse_result?.opcode, valid_parsed_opcodes[idx],
+                parse_result?.opcode, parsed_opcode,
                 "query: {:02x?}, opcode: {}",
                 dns_query, opcode
             );
@@ -304,4 +305,59 @@ mod tests {
         assert_eq!(parse_result?.message_type, DNSMessageType::Response);
         Ok(())
     }
+
+    #[test]
+    fn parse_dns_header_response_code_invalid() {
+        let mut dns_query = [
+            0xff, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        ];
+        let invalid_rcodes = [11, 12, 13, 14, 15];
+
+        for rcode in invalid_rcodes {
+            dns_query[3] = (rcode as u8) << 0;
+
+            let parse_result = DNSHeader::from_udp_datagram(&dns_query);
+
+            assert_eq!(
+                parse_result,
+                Err(DNSParseError::DNSRCodeInvalid),
+                "query: {:02x?}, rcode: {}",
+                dns_query,
+                rcode,
+            );
+        }
+    }
+
+    #[test]
+    fn parse_dns_header_response_code_valid() -> Result<(), DNSParseError> {
+        let mut dns_query = [
+            0xff, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        ];
+
+        // for now we only support RCodes 0 to 10 (inclusive)
+        let valid_rcodes = [
+            (0, DNSRCode::NoError),
+            (1, DNSRCode::FormErr),
+            (2, DNSRCode::ServFail),
+            (3, DNSRCode::NXDomain),
+            (4, DNSRCode::NotImp),
+            (5, DNSRCode::Refused),
+            (6, DNSRCode::YXDomain),
+            (7, DNSRCode::YXRRSet),
+            (8, DNSRCode::NXRRSet),
+            (9, DNSRCode::NotAuth),
+            (10, DNSRCode::NotZone),
+        ];
+
+        for (rcode, parsed_rcode) in valid_rcodes {
+            dns_query[3] = rcode << 0;
+            let parse_result = DNSHeader::from_udp_datagram(&dns_query);
+            assert_eq!(
+                parse_result?.response_code, parsed_rcode,
+                "query: {:02x?}, rcode: {}, parsed_rcode: {:?}",
+                dns_query, rcode, parsed_rcode
+            );
+        }
+        Ok(())
+    }
 }