From: W.C.A. Wijngaards <wouter@nlnetlabs.nl>
Date: Tue, 8 Nov 2022 12:23:44 +0000 (+0100)
Subject: - Fix to make sure to not read again after a tcp comm point is closed.
X-Git-Tag: release-1.17.1rc1~22
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=52a9e6268ec0580700a1db1146c02e771ed0448a;p=thirdparty%2Funbound.git

- Fix to make sure to not read again after a tcp comm point is closed.
---

diff --git a/doc/Changelog b/doc/Changelog
index 8b2cfb762..23209dabf 100644
--- a/doc/Changelog
+++ b/doc/Changelog
@@ -1,5 +1,6 @@
 8 November 2022: Wouter
 	- Fix to ignore tcp events for closed comm points.
+	- Fix to make sure to not read again after a tcp comm point is closed.
 
 21 October 2022: George
 	- Merge #767 from jonathangray: consistently use IPv4/IPv6 in
diff --git a/util/netevent.c b/util/netevent.c
index 09def2e44..6ddeb076d 100644
--- a/util/netevent.c
+++ b/util/netevent.c
@@ -2545,8 +2545,9 @@ comm_point_tcp_handle_write(int fd, struct comm_point* c)
 	return 1;
 }
 
-/** read again to drain buffers when there could be more to read */
-static void
+/** read again to drain buffers when there could be more to read, returns 0
+ * on failure which means the comm point is closed. */
+static int
 tcp_req_info_read_again(int fd, struct comm_point* c)
 {
 	while(c->tcp_req_info->read_again) {
@@ -2563,9 +2564,10 @@ tcp_req_info_read_again(int fd, struct comm_point* c)
 				(void)(*c->callback)(c, c->cb_arg, 
 					NETEVENT_CLOSED, NULL);
 			}
-			return;
+			return 0;
 		}
 	}
+	return 1;
 }
 
 /** read again to drain buffers when there could be more to read */
@@ -2663,7 +2665,6 @@ comm_point_tcp_handle_callback(int fd, short event, void* arg)
 #endif
 		) {
 		int has_tcpq = (c->tcp_req_info != NULL);
-		int* moreread = c->tcp_more_read_again;
 		if(!comm_point_tcp_handle_read(fd, c, 0)) {
 			reclaim_tcp_handler(c);
 			if(!c->tcp_do_close) {
@@ -2674,15 +2675,16 @@ comm_point_tcp_handle_callback(int fd, short event, void* arg)
 			}
 			return;
 		}
-		if(has_tcpq && c->tcp_req_info && c->tcp_req_info->read_again)
-			tcp_req_info_read_again(fd, c);
-		if(moreread && *moreread)
+		if(has_tcpq && c->tcp_req_info && c->tcp_req_info->read_again) {
+			if(!tcp_req_info_read_again(fd, c))
+				return;
+		}
+		if(c->tcp_more_read_again && *c->tcp_more_read_again)
 			tcp_more_read_again(fd, c);
 		return;
 	}
 	if(event&UB_EV_WRITE) {
 		int has_tcpq = (c->tcp_req_info != NULL);
-		int* morewrite = c->tcp_more_write_again;
 		if(!comm_point_tcp_handle_write(fd, c)) {
 			reclaim_tcp_handler(c);
 			if(!c->tcp_do_close) {
@@ -2693,9 +2695,11 @@ comm_point_tcp_handle_callback(int fd, short event, void* arg)
 			}
 			return;
 		}
-		if(has_tcpq && c->tcp_req_info && c->tcp_req_info->read_again)
-			tcp_req_info_read_again(fd, c);
-		if(morewrite && *morewrite)
+		if(has_tcpq && c->tcp_req_info && c->tcp_req_info->read_again) {
+			if(!tcp_req_info_read_again(fd, c))
+				return;
+		}
+		if(c->tcp_more_write_again && *c->tcp_more_write_again)
 			tcp_more_write_again(fd, c);
 		return;
 	}