From b7d9dc14eb560b1d19f506610535815f29085579 Mon Sep 17 00:00:00 2001
From: Dirk Engling <erdgeist@erdgeist.org>
Date: Sat, 31 Oct 2026 19:43:36 +0100
Subject: Make the dynamic accesslist readers release their line buffer and
 properly exit

---
 ot_accesslist.c | 46 +++++++++++++++++++++++++++++++++++++++++-----
 1 file changed, 41 insertions(+), 5 deletions(-)

(limited to 'ot_accesslist.c')

diff --git a/ot_accesslist.c b/ot_accesslist.c
index e8e0476..df084b8 100644
--- a/ot_accesslist.c
+++ b/ot_accesslist.c
@@ -273,7 +273,8 @@ static void *accesslist_worker(void *args) {
 }
 
 #ifdef WANT_DYNAMIC_ACCESSLIST
-static pthread_t thread_adder_id, thread_deleter_id;
+static pthread_t   thread_adder_id, thread_deleter_id;
+static _Atomic int adder_left, deleter_left;
 static void     *accesslist_adddel_worker(const char *fifoname, ot_accesslist *_Atomic *adding_to, ot_accesslist *_Atomic *removing_from) {
   struct stat st;
 
@@ -297,6 +298,9 @@ static void     *accesslist_adddel_worker(const char *fifoname, ot_accesslist *_
     ssize_t linelen;
 
     if (!fifo) {
+      /* Woken on purpose: the loop condition above decides what happens next */
+      if (errno == EINTR)
+        continue;
       fprintf(stderr, "Error when reading dynamic accesslists: Couldn't open FIFO at %s, error: %s\n", fifoname, strerror(errno));
       return NULL;
     }
@@ -324,8 +328,14 @@ static void     *accesslist_adddel_worker(const char *fifoname, ot_accesslist *_
           ptrdiff_t      off            = exactmatch - (*removing_from)->list;
           ot_accesslist *accesslist_new = accesslist_make(*removing_from, (*removing_from)->size - 1);
           if (accesslist_new) {
-            memcpy(accesslist_new->list, (*removing_from)->list, sizeof(ot_hash) * off);
-            memcpy(accesslist_new->list + off, (*removing_from)->list + off + 1, sizeof(ot_hash) * ((*removing_from)->size - off - 1));
+            size_t after = (*removing_from)->size - off - 1;
+
+            /* Removing the only entry leaves a list with no room at all, and
+               memcpy may not be handed that even for nothing */
+            if (off)
+              memcpy(accesslist_new->list, (*removing_from)->list, sizeof(ot_hash) * off);
+            if (after)
+              memcpy(accesslist_new->list + off, (*removing_from)->list + off + 1, sizeof(ot_hash) * after);
             (*removing_from)->base = time_now_minutes();
             *removing_from = accesslist_new;
           }
@@ -360,6 +370,7 @@ static void     *accesslist_adddel_worker(const char *fifoname, ot_accesslist *_
       pthread_mutex_unlock(&g_accesslist_mutex);
     }
 
+    free(line);
     fclose(fifo);
   }
   return NULL;
@@ -367,11 +378,30 @@ static void     *accesslist_adddel_worker(const char *fifoname, ot_accesslist *_
 
 static void *accesslist_adder_worker(void *args) {
   (void)args;
-  return accesslist_adddel_worker(g_accesslist_pipe_add, &g_accesslist_add, &g_accesslist_delete);
+  accesslist_adddel_worker(g_accesslist_pipe_add, &g_accesslist_add, &g_accesslist_delete);
+  atomic_store(&adder_left, 1);
+  return NULL;
 }
 static void *accesslist_deleter_worker(void *args) {
   (void)args;
-  return accesslist_adddel_worker(g_accesslist_pipe_delete, &g_accesslist_delete, &g_accesslist_add);
+  accesslist_adddel_worker(g_accesslist_pipe_delete, &g_accesslist_delete, &g_accesslist_add);
+  atomic_store(&deleter_left, 1);
+  return NULL;
+}
+
+/* These sit in a blocking open or read on a FIFO, so they are woken the way
+   the other workers are, and the signal is repeated because it only
+   interrupts a call already under way. The pipe name is what says whether
+   the thread was ever started. */
+static void accesslist_stop_fifo_worker(pthread_t thread, _Atomic int *left, const char *pipe_name) {
+  if (!pipe_name)
+    return;
+
+  while (!atomic_load(left)) {
+    pthread_kill(thread, OT_SIGNAL_WAKE);
+    usleep(1000);
+  }
+  pthread_join(thread, NULL);
 }
 #endif
 
@@ -392,6 +422,12 @@ void accesslist_deinit(void) {
   pthread_kill(thread_id, SIGHUP);
   pthread_join(thread_id, NULL);
 
+#ifdef WANT_DYNAMIC_ACCESSLIST
+  /* Before the lists they are reading are freed below */
+  accesslist_stop_fifo_worker(thread_adder_id, &adder_left, g_accesslist_pipe_add);
+  accesslist_stop_fifo_worker(thread_deleter_id, &deleter_left, g_accesslist_pipe_delete);
+#endif
+
   pthread_mutex_lock(&g_accesslist_mutex);
 
   g_accesslist = accesslist_free(g_accesslist);
-- 
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