From 846b618fe219c44dfc7b3a13aadace2198442c9c Mon Sep 17 00:00:00 2001
From: Thomas Karpiniec <tom.karpiniec@outlook.com>
Date: Thu, 6 Jun 2024 20:10:45 +1000
Subject: [PATCH 1/1] List interfaces on Mac

---
 Cargo.lock     | 53 +++++++++++++++++++++++++++++++++++++
 Cargo.toml     |  5 +++-
 src/imp_mac.rs | 72 ++++++++++++++++++++++++++++++++++++++++++++++++++
 src/lib.rs     |  2 ++
 src/util.rs    | 13 +++++++++
 5 files changed, 144 insertions(+), 1 deletion(-)
 create mode 100644 src/imp_mac.rs
 create mode 100644 src/util.rs

diff --git a/Cargo.lock b/Cargo.lock
index b7d6ccc..9af9c1b 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -2,13 +2,66 @@
 # It is not intended for manual editing.
 version = 3
 
+[[package]]
+name = "autocfg"
+version = "1.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0c4b4d0bd25bd0b74681c0ad21497610ce1b7c91b1022cd21c80c6fbdd9476b0"
+
+[[package]]
+name = "bitflags"
+version = "2.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "cf4b9d6a944f767f8e5e0db018570623c85f3d925ac718db4e06d0187adb21c1"
+
+[[package]]
+name = "cfg-if"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd"
+
+[[package]]
+name = "cfg_aliases"
+version = "0.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "613afe47fcd5fac7ccf1db93babcb082c5994d996f20b8b159f2ad1658eb5724"
+
+[[package]]
+name = "libc"
+version = "0.2.155"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "97b3888a4aecf77e811145cadf6eef5901f4782c53886191b2f693f24761847c"
+
+[[package]]
+name = "memoffset"
+version = "0.9.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "488016bfae457b036d996092f6cb448677611ce4449e970ceaf42695203f218a"
+dependencies = [
+ "autocfg",
+]
+
 [[package]]
 name = "netwatcher"
 version = "0.1.0"
 dependencies = [
+ "nix",
  "windows",
 ]
 
+[[package]]
+name = "nix"
+version = "0.29.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "71e2746dc3a24dd78b3cfcb7be93368c6de9963d30f43a6a73998a9cf4b17b46"
+dependencies = [
+ "bitflags",
+ "cfg-if",
+ "cfg_aliases",
+ "libc",
+ "memoffset",
+]
+
 [[package]]
 name = "proc-macro2"
 version = "1.0.84"
diff --git a/Cargo.toml b/Cargo.toml
index 04dea3f..2615972 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -5,7 +5,10 @@ edition = "2021"
 
 [dependencies]
 
-[dependencies.windows]
+[target.'cfg(unix)'.dependencies]
+nix = { version = "0.29.0", features = ["net"] }
+
+[target.'cfg(windows)'.dependencies.windows]
 version = "0.56.0"
 features = [
     "Win32_NetworkManagement_IpHelper",
diff --git a/src/imp_mac.rs b/src/imp_mac.rs
new file mode 100644
index 0000000..c4fc8d6
--- /dev/null
+++ b/src/imp_mac.rs
@@ -0,0 +1,72 @@
+use std::{collections::HashMap, net::IpAddr};
+
+use nix::{ifaddrs::getifaddrs, net::if_::if_nametoindex};
+
+use crate::util::format_mac;
+use crate::{Error, IfIndex, Interface};
+
+struct CandidateInterface {
+    name: String,
+    index: u32,
+    hw_addr: Option<String>,
+    ips: Vec<IpAddr>,
+}
+
+pub(crate) fn list_interfaces() -> Result<HashMap<IfIndex, Interface>, Error> {
+    let addrs = getifaddrs().map_err(|_| Error::Internal)?;
+    let mut candidates = HashMap::new();
+
+    for addr in addrs {
+        let index = if_nametoindex(addr.interface_name.as_str()).map_err(|_| Error::Internal)?;
+        let candidate = candidates
+            .entry(addr.interface_name.clone())
+            .or_insert_with(|| CandidateInterface {
+                name: addr.interface_name.clone(),
+                index,
+                hw_addr: None,
+                ips: vec![],
+            });
+        if let Some(a) = addr.address {
+            if let Some(a) = a.as_link_addr() {
+                if let Some(raw_addr) = a.addr() {
+                    candidate.hw_addr = Some(format_mac(&raw_addr)?);
+                }
+            }
+            if let Some(a) = a.as_sockaddr_in() {
+                candidate.ips.push(IpAddr::V4(a.ip()));
+            }
+            if let Some(a) = a.as_sockaddr_in6() {
+                candidate.ips.push(IpAddr::V6(a.ip()));
+            }
+        }
+    }
+
+    let ifs = candidates
+        .drain()
+        .flat_map(|(_, c)| {
+            c.hw_addr.map(|hw_addr| {
+                (
+                    c.index,
+                    Interface {
+                        index: c.index,
+                        hw_addr,
+                        name: c.name,
+                        ips: c.ips,
+                    },
+                )
+            })
+        })
+        .collect();
+    Ok(ifs)
+}
+
+#[cfg(test)]
+mod test {
+    use super::list_interfaces;
+
+    #[test]
+    fn list() {
+        let ifaces = list_interfaces().unwrap();
+        println!("{:?}", ifaces);
+    }
+}
diff --git a/src/lib.rs b/src/lib.rs
index af5b7af..9f82092 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -4,7 +4,9 @@ use std::{
 };
 
 #[cfg_attr(windows, path = "imp_win.rs")]
+#[cfg_attr(target_vendor = "apple", path = "imp_mac.rs")]
 mod imp;
+mod util;
 
 type IfIndex = u32;
 
diff --git a/src/util.rs b/src/util.rs
new file mode 100644
index 0000000..bbc4e6c
--- /dev/null
+++ b/src/util.rs
@@ -0,0 +1,13 @@
+use crate::Error;
+use std::fmt::Write;
+
+pub(crate) fn format_mac(bytes: &[u8]) -> Result<String, Error> {
+    let mut mac = String::with_capacity(bytes.len() * 3);
+    for i in 0..bytes.len() {
+        if i != 0 {
+            write!(mac, ":").map_err(|_| Error::Internal)?;
+        }
+        write!(mac, "{:02X}", bytes[i]).map_err(|_| Error::Internal)?;
+    }
+    Ok(mac)
+}
-- 
2.39.5