From 55896df79d9f537577834375cb21676e8176b5ed Mon Sep 17 00:00:00 2001
From: Evan Hunt <each@isc.org>
Date: Wed, 1 Jul 2020 16:17:09 -0700
Subject: [PATCH] use handles for isc_nm_pauseread() and isc_nm_resumeread()

by having these functions act on netmgr handles instead of socket
objects, they can be used in callback functions outside the netgmr.
---
 lib/isc/include/isc/netmgr.h | 15 +++++++++------
 lib/isc/netmgr/netmgr.c      | 12 ++++++++----
 lib/isc/netmgr/tcpdns.c      | 10 +++++-----
 lib/isc/win32/libisc.def.in  |  2 ++
 4 files changed, 24 insertions(+), 15 deletions(-)

diff --git a/lib/isc/include/isc/netmgr.h b/lib/isc/include/isc/netmgr.h
index 99d41f01f4..3f6d8f6f05 100644
--- a/lib/isc/include/isc/netmgr.h
+++ b/lib/isc/include/isc/netmgr.h
@@ -204,9 +204,12 @@ isc_result_t
 isc_nm_read(isc_nmhandle_t *handle, isc_nm_recv_cb_t cb, void *cbarg);
 
 isc_result_t
-isc_nm_pauseread(isc_nmsocket_t *sock);
+isc_nm_pauseread(isc_nmhandle_t *handle);
 /*%<
- * Pause reading on this socket, while still remembering the callback.
+ * Pause reading on this handle's socket, but remember the callback.
+ *
+ * Requires:
+ * \li	'handle' is a valid netmgr handle.
  */
 
 void
@@ -221,13 +224,13 @@ isc_nm_cancelread(isc_nmhandle_t *handle);
  */
 
 isc_result_t
-isc_nm_resumeread(isc_nmsocket_t *sock);
+isc_nm_resumeread(isc_nmhandle_t *handle);
 /*%<
- * Resume reading from socket.
+ * Resume reading on the handle's socket.
  *
  * Requires:
- * \li	'sock' is a valid netmgr socket
- * \li	...for which a read/recv callback has been defined.
+ * \li	'handle' is a valid netmgr handle.
+ * \li	...for a socket with a defined read/recv callback.
  */
 
 isc_result_t
diff --git a/lib/isc/netmgr/netmgr.c b/lib/isc/netmgr/netmgr.c
index 432d612dbe..0cdf5b3e9c 100644
--- a/lib/isc/netmgr/netmgr.c
+++ b/lib/isc/netmgr/netmgr.c
@@ -1379,8 +1379,10 @@ isc_nm_cancelread(isc_nmhandle_t *handle) {
 }
 
 isc_result_t
-isc_nm_pauseread(isc_nmsocket_t *sock) {
-	REQUIRE(VALID_NMSOCK(sock));
+isc_nm_pauseread(isc_nmhandle_t *handle) {
+	REQUIRE(VALID_NMHANDLE(handle));
+
+	isc_nmsocket_t *sock = handle->sock;
 
 	switch (sock->type) {
 	case isc_nm_tcpsocket:
@@ -1392,8 +1394,10 @@ isc_nm_pauseread(isc_nmsocket_t *sock) {
 }
 
 isc_result_t
-isc_nm_resumeread(isc_nmsocket_t *sock) {
-	REQUIRE(VALID_NMSOCK(sock));
+isc_nm_resumeread(isc_nmhandle_t *handle) {
+	REQUIRE(VALID_NMHANDLE(handle));
+
+	isc_nmsocket_t *sock = handle->sock;
 
 	switch (sock->type) {
 	case isc_nm_tcpsocket:
diff --git a/lib/isc/netmgr/tcpdns.c b/lib/isc/netmgr/tcpdns.c
index 05cc410d68..512f88be03 100644
--- a/lib/isc/netmgr/tcpdns.c
+++ b/lib/isc/netmgr/tcpdns.c
@@ -283,7 +283,7 @@ dnslisten_readcb(isc_nmhandle_t *handle, isc_result_t eresult,
 			 * one packet, so we're done until the next read
 			 * completes.
 			 */
-			isc_nm_pauseread(dnssock->outerhandle->sock);
+			isc_nm_pauseread(dnssock->outerhandle);
 			done = true;
 		} else {
 			/*
@@ -295,7 +295,7 @@ dnslisten_readcb(isc_nmhandle_t *handle, isc_result_t eresult,
 			 */
 			if (atomic_load(&dnssock->ah) >=
 			    TCPDNS_CLIENTS_PER_CONN) {
-				isc_nm_pauseread(dnssock->outerhandle->sock);
+				isc_nm_pauseread(dnssock->outerhandle);
 				done = true;
 			}
 		}
@@ -376,7 +376,7 @@ isc_nm_tcpdns_sequential(isc_nmhandle_t *handle) {
 	 * closehandle_cb callback, called whenever a handle
 	 * is released.
 	 */
-	isc_nm_pauseread(handle->sock->outerhandle->sock);
+	isc_nm_pauseread(handle->sock->outerhandle);
 	atomic_store(&handle->sock->sequential, true);
 }
 
@@ -431,7 +431,7 @@ resume_processing(void *arg) {
 			}
 			isc_nmhandle_unref(handle);
 		} else if (sock->outerhandle != NULL) {
-			result = isc_nm_resumeread(sock->outerhandle->sock);
+			result = isc_nm_resumeread(sock->outerhandle);
 			if (result != ISC_R_SUCCESS) {
 				isc_nmhandle_unref(sock->outerhandle);
 				sock->outerhandle = NULL;
@@ -454,7 +454,7 @@ resume_processing(void *arg) {
 			 * Nothing in the buffer; resume reading.
 			 */
 			if (sock->outerhandle != NULL) {
-				isc_nm_resumeread(sock->outerhandle->sock);
+				isc_nm_resumeread(sock->outerhandle);
 			}
 
 			break;
diff --git a/lib/isc/win32/libisc.def.in b/lib/isc/win32/libisc.def.in
index 7313a73acb..102a2263ed 100644
--- a/lib/isc/win32/libisc.def.in
+++ b/lib/isc/win32/libisc.def.in
@@ -457,7 +457,9 @@ isc_nm_listentcpdns
 isc_nm_listentcp
 isc_nm_listenudp
 isc_nm_maxudp
+isc_nm_pauseread
 isc_nm_read
+isc_nm_resumeread
 isc_nm_send
 isc_nm_setstats
 isc_nm_start