From d23efed20f5aea6e2067e7c9ec65f2ceca83ba7a Mon Sep 17 00:00:00 2001
From: Will Toohey <will@mon.im>
Date: Fri, 8 Dec 2023 10:21:58 +1000
Subject: [PATCH 1/2] Windows: Dynamically determine interface count

---
 src/win.rs | 20 +++++++++-----------
 1 file changed, 9 insertions(+), 11 deletions(-)

diff --git a/src/win.rs b/src/win.rs
index f404fd2..e5020d9 100644
--- a/src/win.rs
+++ b/src/win.rs
@@ -14,6 +14,7 @@ use winapi::ctypes::{c_char, c_int};
 use winapi::shared::inaddr::*;
 use winapi::shared::minwindef::DWORD;
 use winapi::shared::minwindef::{INT, LPDWORD};
+use winapi::shared::winerror::ERROR_BUFFER_OVERFLOW;
 use winapi::shared::ws2def::LPWSAMSG;
 use winapi::shared::ws2def::*;
 use winapi::shared::ws2ipdef::*;
@@ -171,18 +172,15 @@ fn create_on_interfaces(
     })
 }
 
-/// The amount of ip's per interface we can support
-/// This was an increase when I suddenly got 60 different IPs registered on my computer
-/// Let's hope we can keep it like that (or increase it even further)
-const PER_INTERFACE_IP_SUPPORT: usize = 5;
-
 fn build_address_table(interfaces: HashSet<Ipv4Addr>) -> io::Result<HashMap<u32, Ipv4Addr>> {
-    let mut buffer = vec![
-        0;
-        mem::size_of::<iptypes::IP_ADAPTER_INFO>()
-            * interfaces.len()
-            * PER_INTERFACE_IP_SUPPORT
-    ];
+    let mut size = 0u32;
+    let r = unsafe { winapi::um::iphlpapi::GetAdaptersInfo(ptr::null_mut(), &mut size) };
+    if r != ERROR_BUFFER_OVERFLOW {
+        return Err(io::Error::last_os_error());
+    }
+
+    let mut buffer =
+        vec![0; mem::size_of::<iptypes::IP_ADAPTER_INFO>() * interfaces.len() * (size as usize)];
     let mut adapter_info = buffer.as_mut_ptr() as iptypes::PIP_ADAPTER_INFO;
     let mut size = buffer.len() as u32;
     let r = unsafe { winapi::um::iphlpapi::GetAdaptersInfo(adapter_info, &mut size) };

From b289c8bd112d30d226224fba1853e80d6457c4ea Mon Sep 17 00:00:00 2001
From: Bruno Tavares <connect+github@bltavares.com>
Date: Sun, 17 Dec 2023 19:27:56 -0300
Subject: [PATCH 2/2] (win) Adjust allocated buffer size for Interface
 information to match the returned interface length

---
 src/win.rs | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/src/win.rs b/src/win.rs
index 5736e5f..2a0dd41 100644
--- a/src/win.rs
+++ b/src/win.rs
@@ -179,8 +179,7 @@ fn build_address_table(interfaces: HashSet<Ipv4Addr>) -> io::Result<HashMap<u32,
         return Err(io::Error::last_os_error());
     }
 
-    let mut buffer =
-        vec![0; mem::size_of::<iptypes::IP_ADAPTER_INFO>() * interfaces.len() * (size as usize)];
+    let mut buffer = vec![0; mem::size_of::<iptypes::IP_ADAPTER_INFO>() * (size as usize)];
     let mut adapter_info = buffer.as_mut_ptr() as iptypes::PIP_ADAPTER_INFO;
     let mut size = buffer.len() as u32;
     let r = unsafe { winapi::um::iphlpapi::GetAdaptersInfo(adapter_info, &mut size) };