From 7d9bdbd950110518f7e9fad850ab357690fcf7d4 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ryan=20O=E2=80=99Hara?= <ryan@ohara.me>
Date: Sat, 6 Jun 2026 19:46:27 -0700
Subject: [PATCH] Clean up distinguished but equivalent path in `vmid_to_ipv4`

For all `vmid`s from 1 to 254, `(vmid >> 8, vmid & 0xff) == ((vmid - 1) // 254, (vmid - 1) % 254 + 1) == (0, vmid)`.
---
 qubes/vm/mix/net.py | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/qubes/vm/mix/net.py b/qubes/vm/mix/net.py
index 04a6ef315..252ce8b56 100644
--- a/qubes/vm/mix/net.py
+++ b/qubes/vm/mix/net.py
@@ -108,13 +108,10 @@ def __str__(self):
 
 
 def vmid_to_ipv4(prefix, vmid):
+    if vmid not in range(1, 256 * 254 + 1):
+        raise ValueError("vmid out of range")
     # avoid .0 and .255 addresses, it may trip some heuristics
     # if OS assumes /24 netmask
-    # preserve unchanged IPs for low vmid
-    if vmid < 255:
-        return ipaddress.IPv4Address(
-            "{}.{}.{}".format(prefix, (vmid >> 8) & 0xFF, vmid & 0xFF)
-        )
     # don't reserve first .1 for vmid 0, as it is invalid
     vmid -= 1
     return ipaddress.IPv4Address(