Add function to free all of the issuer cache.

ok jsing@

1 files changed, 39 insertions, 13 deletions

diff --git a/src/lib/libcrypto/x509/x509_issuer_cache.c b/src/lib/libcrypto/x509/x509_issuer_cache.c
index 26cde17239..4f78e1e69b 100644
--- a/src/lib/libcrypto/x509/x509_issuer_cache.c
+++ b/src/lib/libcrypto/x509/x509_issuer_cache.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: x509_issuer_cache.c,v 1.2 2020/11/18 17:00:59 tb Exp $ */
+/* $OpenBSD: x509_issuer_cache.c,v 1.3 2022/06/27 14:23:40 beck Exp $ */
 /*
  * Copyright (c) 2020 Bob Beck <beck@openbsd.org>
  *
@@ -74,6 +74,40 @@ x509_issuer_cache_set_max(size_t max)
 }
 
 /*
+ * Free the oldest entry in the issuer cache. Returns 1
+ * if an entry was successfuly freed, 0 otherwise. Must
+ * be called with x509_issuer_tree_mutex held.
+ */
+void
+x509_issuer_cache_free_oldest()
+{
+        struct x509_issuer *old;
+
+        if (x509_issuer_cache_count == 0)
+                return;
+        old = TAILQ_LAST(&x509_issuer_lru, lruqueue);
+        TAILQ_REMOVE(&x509_issuer_lru, old, queue);
+        RB_REMOVE(x509_issuer_tree, &x509_issuer_cache, old);
+        free(old->parent_md);
+        free(old->child_md);
+        free(old);
+        x509_issuer_cache_count--;
+}
+
+/*
+ * Free the entire issuer cache, discarding all entries.
+ */
+void
+x509_issuer_cache_free()
+{
+        if (pthread_mutex_lock(&x509_issuer_tree_mutex) != 0)
+                return;
+        while (x509_issuer_cache_count > 0)
+                x509_issuer_cache_free_oldest();
+        (void) pthread_mutex_unlock(&x509_issuer_tree_mutex);
+}
+
+/*
  * Find a previous result of checking if parent signed child
  *
  * Returns:
@@ -140,24 +174,16 @@ x509_issuer_cache_add(unsigned char *parent_md, unsigned char *child_md,
 
         if (pthread_mutex_lock(&x509_issuer_tree_mutex) != 0)
                 goto err;
-        while (x509_issuer_cache_count >= x509_issuer_cache_max) {
-                struct x509_issuer *old;
-                if ((old = TAILQ_LAST(&x509_issuer_lru, lruqueue)) == NULL)
-                        goto err;
-                TAILQ_REMOVE(&x509_issuer_lru, old, queue);
-                RB_REMOVE(x509_issuer_tree, &x509_issuer_cache, old);
-                free(old->parent_md);
-                free(old->child_md);
-                free(old);
-                x509_issuer_cache_count--;
-        }
+        while (x509_issuer_cache_count >= x509_issuer_cache_max)
+                x509_issuer_cache_free_oldest();
         if (RB_INSERT(x509_issuer_tree, &x509_issuer_cache, new) == NULL) {
                 TAILQ_INSERT_HEAD(&x509_issuer_lru, new, queue);
                 x509_issuer_cache_count++;
                 new = NULL;
         }
- err:
         (void) pthread_mutex_unlock(&x509_issuer_tree_mutex);
+
+ err:
         if (new != NULL) {
                 free(new->parent_md);
                 free(new->child_md);