From 8ab0de26908448b9d294e814d6871a65dfd9ea31 Mon Sep 17 00:00:00 2001
From: NetterSilver <133535268+Silvertree2010@users.noreply.github.com>
Date: Sat, 24 Oct 2026 11:25:17 +0200
Subject: [PATCH] Keep wrong join-code streak when a correct code is tried
 (#1174)

Fixes #1088

Co-authored-by: Claude Haiku 5.5 <noreply@anthropic.com>
---
 apps/figcraft-server/src/abuse.rs       |  6 +++---
 apps/figcraft-server/src/codes_tests.rs | 20 ++++++++++++--------
 2 files changed, 15 insertions(+), 11 deletions(-)

diff --git a/apps/figcraft-server/src/abuse.rs b/apps/figcraft-server/src/abuse.rs
index baf1882b..2ea939c3 100644
--- a/apps/figcraft-server/src/abuse.rs
+++ b/apps/figcraft-server/src/abuse.rs
@@ -120,15 +120,15 @@ impl Abuse {
         open
     }
 
-    /// `ip` tried a join code that was right (`ok`) or wrong: a right one forgives the wrong ones
-    /// before it; enough wrong ones in a row lock the address out.
+    /// `ip` tried a join code that was right (`ok`) or wrong: a right one doesn't forgive the wrong
+    /// ones before it (they only decay with time); enough wrong ones lock the address out.
     pub fn code_tried(&mut self, ip: IpAddr, ok: bool, now: Instant) {
         if !ok {
             self.wrong_codes.take(now);
         }
         for (k, times) in ip_blocks(ip) {
             let a = self.address(k, f64::from(times), now);
-            if ok || now.saturating_duration_since(a.wrong_at) > CODE_LOCKOUT {
+            if now.saturating_duration_since(a.wrong_at) > CODE_LOCKOUT {
                 a.wrong = 0;
             }
             if !ok {
diff --git a/apps/figcraft-server/src/codes_tests.rs b/apps/figcraft-server/src/codes_tests.rs
index 6392e552..1e440a32 100644
--- a/apps/figcraft-server/src/codes_tests.rs
+++ b/apps/figcraft-server/src/codes_tests.rs
@@ -262,17 +262,21 @@ fn the_limits_on_codes_over_time() {
     let t0 = Instant::now();
     let me = ip("198.51.100.9");
     let mut abuse = Abuse::new(AbuseConfig { open: false, connects_per_minute: 30, publishes_per_hour: 10, messages_per_second: 200 });
-    // A right code forgives the wrong ones before it.
+    // A right code, even from a neighbour in the same /64, doesn't forgive the wrong ones.
+    let a = ip("2001:db8:1:2::1");
+    let b = ip("2001:db8:1:2::2");
     for _ in 0..WRONG_CODES - 1 {
+        abuse.code_tried(a, false, t0);
+    }
+    abuse.code_tried(b, true, t0);
+    abuse.code_tried(a, true, t0);
+    assert_eq!(abuse.code_locked(a, t0), None);
+    abuse.code_tried(a, false, t0);
+    assert_eq!(abuse.code_locked(a, t0), Some(CODE_LOCKOUT));
+    // Wrong codes: locked for the lockout, then free again.
+    for _ in 0..WRONG_CODES {
         abuse.code_tried(me, false, t0);
     }
-    abuse.code_tried(me, true, t0);
-    for _ in 0..WRONG_CODES - 1 {
-        abuse.code_tried(me, false, t0);
-    }
-    assert_eq!(abuse.code_locked(me, t0), None);
-    // One more: locked for the lockout, then free again.
-    abuse.code_tried(me, false, t0);
     assert_eq!(abuse.code_locked(me, t0), Some(CODE_LOCKOUT));
     assert!(abuse.code_locked(me, t0 + CODE_LOCKOUT - Duration::from_secs(1)).is_some());
     assert_eq!(abuse.code_locked(me, t0 + CODE_LOCKOUT), None);