From 294ceb513c738bf4338d2cbc94e6b864bfdda3d4 Mon Sep 17 00:00:00 2001
From: David Anderson <danderson@tailscale.com>
Date: Tue, 15 Dec 2020 18:45:13 -0800
Subject: [PATCH] ipn, wgengine/magicsock: fix `tailscale status` display.

Signed-off-by: David Anderson <danderson@tailscale.com>
---
 ipn/local.go                    | 10 ++++++++--
 wgengine/magicsock/magicsock.go |  7 ++++++-
 2 files changed, 14 insertions(+), 3 deletions(-)

diff --git a/ipn/local.go b/ipn/local.go
index 52d24e67f..a3c1a6861 100644
--- a/ipn/local.go
+++ b/ipn/local.go
@@ -209,8 +209,14 @@ func (b *LocalBackend) UpdateStatus(sb *ipnstate.StatusBuilder) {
 				lastSeen = *p.LastSeen
 			}
 			var tailAddr string
-			if len(p.Addresses) > 0 {
-				tailAddr = strings.TrimSuffix(p.Addresses[0].String(), "/32")
+			for _, addr := range p.Addresses {
+				// The peer struct currently only allows a single
+				// Tailscale IP address. For compatibility with the
+				// old display, make sure it's the IPv4 address.
+				if addr.IP.Is4() && addr.Mask == 32 && tsaddr.IsTailscaleIP(netaddr.IPFrom16(addr.IP.Addr)) {
+					tailAddr = addr.IP.String()
+					break
+				}
 			}
 			sb.AddPeer(key.Public(p.Key), &ipnstate.PeerStatus{
 				InNetworkMap: true,
diff --git a/wgengine/magicsock/magicsock.go b/wgengine/magicsock/magicsock.go
index 185c4ee8a..2d595bb4d 100644
--- a/wgengine/magicsock/magicsock.go
+++ b/wgengine/magicsock/magicsock.go
@@ -2725,7 +2725,12 @@ func (c *Conn) UpdateStatus(sb *ipnstate.StatusBuilder) {
 				continue
 			}
 			sb.AddTailscaleIP(ip)
-			ss.TailAddr = ip.String()
+			// TailAddr only allows for a single Tailscale IP. For
+			// readability of `tailscale status`, make it the IPv4
+			// address.
+			if addr.IP.Is4() {
+				ss.TailAddr = ip.String()
+			}
 		}
 	}
 	sb.SetSelfStatus(ss)