From 64aae7c863f6e38cecc3cd6d5054f272e13852e8 Mon Sep 17 00:00:00 2001
From: Ian Jackson <ijackson@chiark.greenend.org.uk>
Date: Sun, 12 Oct 2014 22:10:14 +0100
Subject: [PATCH] Reentrancy: Introduce adns__cancel

We need a version of adns_cancel which does not call adns_returning,
for internal call sites who want to avoid reentrancy hazards.

Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>
---
 src/internal.h |  1 +
 src/query.c    | 15 ++++++++++++---
 src/setup.c    |  8 ++++----
 3 files changed, 17 insertions(+), 7 deletions(-)

diff --git a/src/internal.h b/src/internal.h
index 13740b2..d53ea5f 100644
--- a/src/internal.h
+++ b/src/internal.h
@@ -704,6 +704,7 @@ void adns__reset_preserved(adns_query qu);
  * in a datagram and discover that we need to retry the query.
  */
 
+void adns__cancel(adns_query qu);
 void adns__query_done(adns_query qu);
 void adns__query_fail(adns_query qu, adns_status stat);
 void adns__cancel_children(adns_query qu);
diff --git a/src/query.c b/src/query.c
index 3e93fc2..0808534 100644
--- a/src/query.c
+++ b/src/query.c
@@ -472,7 +472,7 @@ void adns__cancel_children(adns_query qu) {
 
   for (cqu= qu->children.head; cqu; cqu= ncqu) {
     ncqu= cqu->siblings.next;
-    adns_cancel(cqu);
+    adns__cancel(cqu);
   }
 }
 
@@ -500,11 +500,11 @@ void adns__returning(adns_state ads, adns_query qu_for_caller) {
   adns__consistency(ads,qu_for_caller,cc_entex);
 }
 
-void adns_cancel(adns_query qu) {
+void adns__cancel(adns_query qu) {
   adns_state ads;
 
   ads= qu->ads;
-  adns__consistency(ads,qu,cc_entex);
+  adns__consistency(ads,qu,cc_freq);
   if (qu->parent) LIST_UNLINK_PART(qu->parent->children,qu,siblings.);
   switch (qu->state) {
   case query_tosend:
@@ -525,6 +525,15 @@ void adns_cancel(adns_query qu) {
   free_query_allocs(qu);
   free(qu->answer);
   free(qu);
+}
+
+void adns_cancel(adns_query qu) {
+  adns_state ads;
+
+  assert(!qu->parent);
+  ads= qu->ads;
+  adns__consistency(ads,qu,cc_entex);
+  adns__cancel(qu);
   adns__returning(ads,0);
 }
 
diff --git a/src/setup.c b/src/setup.c
index 54d2d0f..3419cd6 100644
--- a/src/setup.c
+++ b/src/setup.c
@@ -725,10 +725,10 @@ void adns_finish(adns_state ads) {
   int i;
   adns__consistency(ads,0,cc_entex);
   for (;;) {
-    if (ads->udpw.head) adns_cancel(ads->udpw.head);
-    else if (ads->tcpw.head) adns_cancel(ads->tcpw.head);
-    else if (ads->childw.head) adns_cancel(ads->childw.head);
-    else if (ads->output.head) adns_cancel(ads->output.head);
+    if (ads->udpw.head) adns__cancel(ads->udpw.head);
+    else if (ads->tcpw.head) adns__cancel(ads->tcpw.head);
+    else if (ads->childw.head) adns__cancel(ads->childw.head);
+    else if (ads->output.head) adns__cancel(ads->output.head);
     else break;
   }
   for (i=0; i<ads->nudp; i++) close(ads->udpsocket[i].fd);
-- 
2.30.2