From a832bc5bcceb1f6b100e95f3901381a58e4ae2f9 Mon Sep 17 00:00:00 2001
From: Adam Ierymenko <adam.ierymenko@zerotier.com>
Date: Fri, 23 Jul 2021 18:08:18 -0400
Subject: [PATCH] Rusty InetAddress

---
 network-hypervisor/src/vl1/inetaddress.rs | 45 +++++++++++++++++++++--
 1 file changed, 41 insertions(+), 4 deletions(-)

diff --git a/network-hypervisor/src/vl1/inetaddress.rs b/network-hypervisor/src/vl1/inetaddress.rs
index 6cfad625c..7cfa28093 100644
--- a/network-hypervisor/src/vl1/inetaddress.rs
+++ b/network-hypervisor/src/vl1/inetaddress.rs
@@ -5,12 +5,12 @@ use std::cmp::Ordering;
 use std::hash::{Hash, Hasher};
 use std::net::{IpAddr, Ipv6Addr};
 
-#[cfg(windows)]
-use winapi::um::winsock2 as winsock2;
-
 use crate::error::InvalidFormatError;
 use crate::util::equal_bytes;
 
+#[cfg(windows)]
+use winapi::um::winsock2 as winsock2;
+
 #[allow(non_camel_case_types)]
 #[cfg(not(windows))]
 type sockaddr = libc::sockaddr;
@@ -47,6 +47,9 @@ pub enum IpScope {
     Private = 7
 }
 
+/// An IPv4 or IPv6 socket address that directly encapsulates C sockaddr types.
+/// The ZeroTier core uses this in preference to std::net stuff so this can be
+/// directly used via the C API or with C socket I/O functions.
 #[repr(C)]
 pub union InetAddress {
     sa: sockaddr,
@@ -71,7 +74,41 @@ impl InetAddress {
     /// Zero the contents of this InetAddress.
     #[inline(always)]
     pub fn zero(&mut self) {
-        unsafe { write_bytes((self as *mut InetAddress).cast::<u8>(), 0, size_of::<Self>()) };
+        unsafe { write_bytes((self as *mut Self).cast::<u8>(), 0, size_of::<Self>()) };
+    }
+
+    /// Get an instance of 127.0.0.1/port
+    pub fn ipv4_loopback(port: u16) -> InetAddress {
+        let mut addr = Self::new();
+        addr.sin.sin_family = AF_INET.into();
+        addr.sin.sin_port = port.to_be().into();
+        addr.sin.sin_addr.s_addr = (0x7f000001 as u32).to_be();
+        addr
+    }
+
+    /// Get an instance of 0.0.0.0/0
+    pub fn ipv4_any() -> InetAddress {
+        let mut addr = Self::new();
+        addr.sin.sin_family = AF_INET.into();
+        addr
+    }
+
+    /// Get an instance of ::1/port
+    pub fn ipv6_loopback(port: u16) -> InetAddress {
+        let mut addr = Self::new();
+        addr.sin6.sin6_family = AF_INET6.into();
+        addr.sin6.sin6_port = port.to_be().into();
+        unsafe {
+            *((&mut (addr.sin6.sin6_addr) as *mut in6_addr).cast::<u8>().offset(15)) = 1;
+        }
+        addr
+    }
+
+    /// Get an instance of ::0/0
+    pub fn ipv6_any() -> InetAddress {
+        let mut addr = Self::new();
+        addr.sin6.sin6_family = AF_INET6.into();
+        addr
     }
 
     /// Returns true if this InetAddress is the nil value (zero).