fix build error (linux/arm/whatever) (#30)

* implement EUI-48 -> EUI-64 (modified) myself: instead of relying on to_modified_eui64 from advmac, because it doesn't compile on arm
* switch from mac_address2 to mac_address due to a bug returning loopback mac on non-windows platforms
* make ipv6 selection more readable in code

Cargo.toml

@@ -6,11 +6,10 @@ edition = "2021"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
-advmac = "1.0.3"
 clap = { version = "4.2.7", features = ["derive"] }
 directories = "5.0.1"
 local-ip-address = "0.5.3"
-mac_address2 = "2.0.0"
+mac_address = "1.1.4"
 reqwest = { version = "0.11.17", default-features = false, features = [
     "json",
     "rustls-tls",

src/ip.rs

@@ -1,7 +1,6 @@
 use crate::structs::{config::Config, Ipify};
-use advmac::MacAddr6;
 use local_ip_address::list_afinet_netifas;
-use mac_address2::get_mac_address;
+use mac_address::get_mac_address;
 use reqwest::Client as HttpClient;
 use std::net::{IpAddr, Ipv4Addr, Ipv6Addr};
 
@@ -74,9 +73,7 @@ pub(crate) async fn determine_ipv6(config: &Config) -> Option<Ipv6Addr> {
 
     if config.ipv6.prefer_eui64 {
         let mac = get_mac_address().ok()?;
-        let eui48 = MacAddr6::new(mac?.bytes());
-        let eui64 = eui48.to_modified_eui64();
-        let suffix = eui64.to_array();
+        let suffix = eui48_to_modified_eui64(&mac?.bytes())?;
         if let Some(x) = ipv6_addresses.iter().find(|ip| match split_ipv6(ip) {
             Some((_, s)) => s == suffix,
             None => false,
@@ -85,22 +82,34 @@ pub(crate) async fn determine_ipv6(config: &Config) -> Option<Ipv6Addr> {
         };
     }
 
-    if !config.ipv6.prefer_outgoing {
-        return ipv6_addresses
-            .into_iter()
-            .filter(|ip| ip != &ipv6)
-            .collect::<Vec<_>>()
-            .first()
-            .cloned();
+    if config.ipv6.prefer_outgoing {
+        return Some(ipv6);
     }
 
-    Some(ipv6)
+    return ipv6_addresses
+        .into_iter()
+        .filter(|ip| ip != &ipv6)
+        .collect::<Vec<_>>()
+        .first()
+        .cloned();
 }
 
 fn split_ipv6(ipv6: &Ipv6Addr) -> Option<([u8; 8], [u8; 8])> {
     let octets = ipv6.octets();
-    let (octets_prefix, octets_suffix) = octets.split_at(8);
-    let prefix: [u8; 8] = octets_prefix.try_into().ok()?;
-    let suffix: [u8; 8] = octets_suffix.try_into().ok()?;
+    let (p, s) = octets.split_at(8);
+    let prefix: [u8; 8] = p.try_into().ok()?;
+    let suffix: [u8; 8] = s.try_into().ok()?;
     Some((prefix, suffix))
 }
+
+fn eui48_to_modified_eui64(eui48: &[u8; 6]) -> Option<[u8; 8]> {
+    let (p, s) = eui48.split_at(3);
+    let prefix: [u8; 3] = p.try_into().ok()?;
+    let suffix: [u8; 3] = s.try_into().ok()?;
+    let eui64 = [
+        prefix[0], prefix[1], prefix[2], 0xff, 0xfe, suffix[0], suffix[1], suffix[2],
+    ];
+    let mut modified_eui64 = eui64;
+    modified_eui64[0] ^= 0b0000_0010;
+    Some(modified_eui64)
+}