From 5381697dbc3507705d3f9f6e0946e0982242eaff Mon Sep 17 00:00:00 2001
From: Vsevolod Stakhov <vsevolod@highsecure.ru>
Date: Sun, 2 Jan 2022 20:49:45 +0000
Subject: [PATCH] [Fix] Fix removing from khash

---
 contrib/librdns/resolver.c |  2 +-
 contrib/librdns/util.c     | 33 +++++++++++++++++++--------------
 contrib/librdns/util.h     |  6 ++++++
 3 files changed, 26 insertions(+), 15 deletions(-)

diff --git a/contrib/librdns/resolver.c b/contrib/librdns/resolver.c
index 05d838317..c27d9afcc 100644
--- a/contrib/librdns/resolver.c
+++ b/contrib/librdns/resolver.c
@@ -507,7 +507,7 @@ rdns_process_timer (void *arg)
 			req->async->del_timer (req->async->data,
 					req->async_event);
 			req->async_event = NULL;
-			kh_del(rdns_requests_hash, req->io->requests, req->id);
+			rdns_request_remove_from_hash(req);
 		}
 
 		/* We have not scheduled timeout actually due to send error */
diff --git a/contrib/librdns/util.c b/contrib/librdns/util.c
index 9b74b7466..2fc9ec6c3 100644
--- a/contrib/librdns/util.c
+++ b/contrib/librdns/util.c
@@ -40,6 +40,21 @@
 #include "logger.h"
 #include "rdns.h"
 
+inline void
+rdns_request_remove_from_hash (struct rdns_request *req)
+{
+	/* Remove from id hashes */
+	if (req->io) {
+		khiter_t k;
+
+		k = kh_get(rdns_requests_hash, req->io->requests, req->id);
+
+		if (k != kh_end(req->io->requests)) {
+			kh_del(rdns_requests_hash, req->io->requests, req->id);
+		}
+	}
+}
+
 static int
 rdns_make_socket_nonblocking (int fd)
 {
@@ -457,19 +472,14 @@ rdns_request_free (struct rdns_request *req)
 				/* Remove timer */
 				req->async->del_timer (req->async->data,
 						req->async_event);
-				/* Remove from id hashes */
-				if (req->io) {
-					kh_del(rdns_requests_hash, req->io->requests, req->id);
-				}
+				rdns_request_remove_from_hash(req);
 				req->async_event = NULL;
 			}
 			else if (req->state == RDNS_REQUEST_WAIT_SEND) {
 				/* Remove retransmit event */
 				req->async->del_write (req->async->data,
 						req->async_event);
-				if (req->io) {
-					kh_del(rdns_requests_hash, req->io->requests, req->id);
-				}
+				rdns_request_remove_from_hash(req);
 				req->async_event = NULL;
 			}
 			else if (req->state == RDNS_REQUEST_FAKE) {
@@ -605,19 +615,14 @@ rdns_request_unschedule (struct rdns_request *req)
 		if (req->state == RDNS_REQUEST_WAIT_REPLY) {
 			req->async->del_timer (req->async->data,
 					req->async_event);
-			/* Remove from id hashes */
-			if (req->io) {
-				kh_del(rdns_requests_hash, req->io->requests, req->id);
-			}
+
 			req->async_event = NULL;
 		}
 		else if (req->state == RDNS_REQUEST_WAIT_SEND) {
 			req->async->del_write (req->async->data,
 					req->async_event);
 			/* Remove from id hashes */
-			if (req->io) {
-				kh_del(rdns_requests_hash, req->io->requests, req->id);
-			}
+			rdns_request_remove_from_hash(req);
 			req->async_event = NULL;
 		}
 	}
diff --git a/contrib/librdns/util.h b/contrib/librdns/util.h
index 5fc94eb80..eea818dee 100644
--- a/contrib/librdns/util.h
+++ b/contrib/librdns/util.h
@@ -63,6 +63,12 @@ struct rdns_io_channel * rdns_ioc_new (struct rdns_server *srv,
  */
 void rdns_request_free (struct rdns_request *req);
 
+/**
+ * Removes request from a channel's hash (e.g. if needed to migrate to another channel)
+ * @param req
+ */
+void rdns_request_remove_from_hash (struct rdns_request *req);
+
 /**
  * Free reply
  * @param rep
-- 
2.39.5