Serde Deserialize+Serialize implementation

Cargo.toml

@@ -14,6 +14,7 @@ description = "mDNS Service Discovery library with no async runtime dependency"
 [features]
 async = ["flume/async"]
 logging = ["log"]
+serde = ["dep:serde"]
 default = ["async", "logging"]
 
 [dependencies]
@@ -24,10 +25,13 @@ log = { version = "0.4", optional = true }             # logging
 mio = { version = "1.1", features = ["os-poll", "net"] }  # select/poll sockets
 socket2 = { version = "0.6", features = ["all"] }      # socket APIs
 socket-pktinfo = "0.3.2"
+# support for serde's deserialize/serialize traits
+serde = { version = "1.0.228", features = ["derive"], optional = true }
 
 [dev-dependencies]
 env_logger = { version = "= 0.10.2", default-features = false, features= ["humantime"] }
 fastrand = "2.3"
 humantime = "2.1"
+serde_json = "1.0.149"
 test-log = "= 0.2.14"
 test-log-macros = "= 0.2.14"

src/dns_parser.rs

@@ -12,6 +12,9 @@ use crate::service_info::is_unicast_link_local;
 
 use if_addrs::Interface;
 
+#[cfg(feature = "serde")]
+use serde::{Deserialize, Serialize};
+
 use std::{
     any::Any,
     cmp,
@@ -25,6 +28,7 @@ use std::{
 
 /// Represents a network interface identifier defined by the OS.
 #[derive(Clone, Debug, Eq, Hash, PartialEq, Default)]
+#[cfg_attr(feature = "serde", derive(Deserialize, Serialize))]
 pub struct InterfaceId {
     /// Interface name, e.g. "en0", "wlan0", etc.
     pub name: String,
@@ -53,6 +57,7 @@ impl From<&Interface> for InterfaceId {
 /// Note: IPv4 addresses don't have scope IDs, but this type is named for consistency
 /// with the rest of the addressing system.
 #[derive(Debug, Clone, Eq, PartialEq, Hash)]
+#[cfg_attr(feature = "serde", derive(Deserialize, Serialize))]
 pub struct ScopedIpV4 {
     addr: Ipv4Addr,
 }
@@ -66,6 +71,7 @@ impl ScopedIpV4 {
 
 /// An IPv6 address with scope_id (interface identifier).
 #[derive(Debug, Clone, Eq, PartialEq, Hash)]
+#[cfg_attr(feature = "serde", derive(Deserialize, Serialize))]
 pub struct ScopedIpV6 {
     addr: Ipv6Addr,
     scope_id: InterfaceId,
@@ -85,6 +91,8 @@ impl ScopedIpV6 {
 
 /// An IP address, either IPv4 or IPv6, that supports scope_id for IPv6.
 #[derive(Debug, Clone, Eq, PartialEq, Hash)]
+#[cfg_attr(feature = "serde", derive(Deserialize, Serialize))]
+#[cfg_attr(feature = "serde", serde(untagged))]
 #[non_exhaustive]
 pub enum ScopedIp {
     V4(ScopedIpV4),

src/service_info.rs

@@ -17,6 +17,9 @@ use std::{
     str::FromStr,
 };
 
+#[cfg(feature = "serde")]
+use serde::{Deserialize, Serialize};
+
 /// Default TTL values in seconds
 const DNS_HOST_TTL: u32 = 120; // 2 minutes for host records (A, SRV etc) per RFC6762
 const DNS_OTHER_TTL: u32 = 4500; // 75 minutes for non-host records (PTR, TXT etc) per RFC6762
@@ -605,6 +608,8 @@ impl AsIpAddrs for Box<dyn AsIpAddrs> {
 /// [RFC 6763](https://www.rfc-editor.org/rfc/rfc6763#section-6.4):
 /// "A given key SHOULD NOT appear more than once in a TXT record."
 #[derive(Debug, Clone, PartialEq, Eq)]
+#[cfg_attr(feature = "serde", derive(Deserialize, Serialize))]
+#[cfg_attr(feature = "serde", serde(transparent))]
 pub struct TxtProperties {
     // Use `Vec` instead of `HashMap` to keep the order of insertions.
     properties: Vec<TxtProperty>,
@@ -703,13 +708,15 @@ impl From<&[u8]> for TxtProperties {
 
 /// Represents a property in a TXT record.
 #[derive(Clone, PartialEq, Eq)]
+#[cfg_attr(feature = "serde", derive(Deserialize, Serialize))]
 pub struct TxtProperty {
     /// The name of the property. The original cases are kept.
     key: String,
 
     /// RFC 6763 says values are bytes, not necessarily UTF-8.
     /// It is also possible that there is no value, in which case
     /// the key is a boolean key.
+    #[cfg_attr(feature = "serde", serde(rename = "value"))]
     val: Option<Vec<u8>>,
 }
 
@@ -1276,6 +1283,7 @@ pub(crate) fn is_unicast_link_local(addr: &Ipv6Addr) -> bool {
 /// Represents a resolved service as a plain data struct.
 /// This is from a client (i.e. querier) point of view.
 #[derive(Clone, Debug)]
+#[cfg_attr(feature = "serde", derive(Deserialize, Serialize))]
 #[non_exhaustive]
 pub struct ResolvedService {
     /// Service type and domain. For example, "_http._tcp.local."
@@ -1371,9 +1379,12 @@ impl ResolvedService {
 #[cfg(test)]
 mod tests {
     use super::{decode_txt, encode_txt, u8_slice_to_hex, ServiceInfo, TxtProperty};
-    use crate::IfKind;
+    use crate::{IfKind, ResolvedService, ScopedIp, TxtProperties};
     use if_addrs::{IfAddr, IfOperStatus, Ifv4Addr, Ifv6Addr, Interface};
-    use std::net::{Ipv4Addr, Ipv6Addr};
+    use std::{
+        collections::HashSet,
+        net::{IpAddr, Ipv4Addr, Ipv6Addr},
+    };
 
     #[test]
     fn test_txt_encode_decode() {
@@ -1697,4 +1708,53 @@ mod tests {
         assert!(!service_info.is_address_supported(&intf_loopback_v4));
         assert!(service_info.is_address_supported(&intf_loopback_v6));
     }
+
+    #[test]
+    fn test_serialize() -> Result<(), Box<dyn std::error::Error>> {
+        let addresses = HashSet::from([
+            ScopedIp::from(IpAddr::V4(Ipv4Addr::new(127, 0, 0, 1))),
+            ScopedIp::from(IpAddr::V6(Ipv6Addr::new(
+                0xfe80, 0x2001, 0x0db8, 0x85a3, 0x0000, 0x8a2e, 0x0370, 0x7334,
+            ))),
+        ]);
+
+        let service = ResolvedService {
+            ty_domain: "_http._tcp.local.".to_owned(),
+            sub_ty_domain: None,
+            fullname: "example._http._tcp.local.".to_owned(),
+            host: "example.local.".to_owned(),
+            port: 1234,
+            addresses: addresses,
+            txt_properties: TxtProperties::new(),
+        };
+
+        let json = serde_json::to_string(&service)?;
+
+        let correct = r#"{
+            "ty_domain": "_http._tcp.local.",
+            "sub_ty_domain": null,
+            "fullname": "example._http._tcp.local.",
+            "host": "example.local.",
+            "port": 1234,
+            "addresses": [
+                {
+                  "addr": "fe80:2001:db8:85a3:0:8a2e:370:7334",
+                  "scope_id": {
+                    "name": "",
+                    "index": 0
+                  }
+                },
+                {
+                  "addr": "127.0.0.1"
+                }
+            ],
+            "txt_properties": []
+        }"#
+        .replace(" ", "")
+        .replace("\n", "");
+
+        assert_eq!(json, correct);
+
+        Ok(())
+    }
 }