From: Evan Hunt <each@isc.org>
Date: Sat, 6 Jun 2020 00:32:36 +0000 (-0700)
Subject: implement isc_nm_cancelread()
X-Git-Tag: v9.17.3~49^2~2
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=5191ec8f86717c0c709aff8971b26951ab5f7353;p=thirdparty%2Fbind9.git

implement isc_nm_cancelread()

The isc_nm_cancelread() function cancels reading on a connected
socket and calls its read callback function with a 'result'
parameter of ISC_R_CANCELED.
---

diff --git a/lib/isc/include/isc/netmgr.h b/lib/isc/include/isc/netmgr.h
index 10b75bd171c..0e2db629ea5 100644
--- a/lib/isc/include/isc/netmgr.h
+++ b/lib/isc/include/isc/netmgr.h
@@ -192,6 +192,17 @@ isc_nm_pauseread(isc_nmsocket_t *sock);
  * Pause reading on this socket, while still remembering the callback.
  */
 
+void
+isc_nm_cancelread(isc_nmhandle_t *handle);
+/*%<
+ * Cancel reading on a connected socket. Calls the read/recv callback on
+ * active handles with a result code of ISC_R_CANCELED.
+ *
+ * Requires:
+ * \li	'sock' is a valid netmgr socket
+ * \li	...for which a read/recv callback has been defined.
+ */
+
 isc_result_t
 isc_nm_resumeread(isc_nmsocket_t *sock);
 /*%<
diff --git a/lib/isc/netmgr/netmgr-int.h b/lib/isc/netmgr/netmgr-int.h
index 5325c8cfbf8..b0b4833e4bd 100644
--- a/lib/isc/netmgr/netmgr-int.h
+++ b/lib/isc/netmgr/netmgr-int.h
@@ -715,7 +715,14 @@ isc__nm_tcp_resumeread(isc_nmsocket_t *sock);
 void
 isc__nm_tcp_shutdown(isc_nmsocket_t *sock);
 /*%<
- * Called on shutdown to close and clean up a listening TCP socket.
+ * Called during the shutdown process to close and clean up connected
+ * sockets.
+ */
+
+void
+isc__nm_tcp_cancelread(isc_nmsocket_t *sock);
+/*%<
+ * Stop reading on a connected socket.
  */
 
 void
diff --git a/lib/isc/netmgr/netmgr.c b/lib/isc/netmgr/netmgr.c
index bf0f8efdd41..7fd029178c1 100644
--- a/lib/isc/netmgr/netmgr.c
+++ b/lib/isc/netmgr/netmgr.c
@@ -1348,9 +1348,24 @@ isc_nm_read(isc_nmhandle_t *handle, isc_nm_recv_cb_t cb, void *cbarg) {
 	}
 }
 
+void
+isc_nm_cancelread(isc_nmhandle_t *handle) {
+	REQUIRE(VALID_NMHANDLE(handle));
+
+	switch (handle->sock->type) {
+	case isc_nm_tcpsocket:
+		isc__nm_tcp_cancelread(handle->sock);
+		break;
+	default:
+		INSIST(0);
+		ISC_UNREACHABLE();
+	}
+}
+
 isc_result_t
 isc_nm_pauseread(isc_nmsocket_t *sock) {
 	REQUIRE(VALID_NMSOCK(sock));
+
 	switch (sock->type) {
 	case isc_nm_tcpsocket:
 		return (isc__nm_tcp_pauseread(sock));
@@ -1363,6 +1378,7 @@ isc_nm_pauseread(isc_nmsocket_t *sock) {
 isc_result_t
 isc_nm_resumeread(isc_nmsocket_t *sock) {
 	REQUIRE(VALID_NMSOCK(sock));
+
 	switch (sock->type) {
 	case isc_nm_tcpsocket:
 		return (isc__nm_tcp_resumeread(sock));
@@ -1375,6 +1391,7 @@ isc_nm_resumeread(isc_nmsocket_t *sock) {
 void
 isc_nm_stoplistening(isc_nmsocket_t *sock) {
 	REQUIRE(VALID_NMSOCK(sock));
+
 	switch (sock->type) {
 	case isc_nm_udplistener:
 		isc__nm_udp_stoplistening(sock);
diff --git a/lib/isc/netmgr/tcp.c b/lib/isc/netmgr/tcp.c
index 5e1a57ec7b1..48c03148207 100644
--- a/lib/isc/netmgr/tcp.c
+++ b/lib/isc/netmgr/tcp.c
@@ -1079,3 +1079,15 @@ isc__nm_tcp_shutdown(isc_nmsocket_t *sock) {
 		sock->rcb.recv(sock->tcphandle, NULL, sock->rcbarg);
 	}
 }
+
+void
+isc__nm_tcp_cancelread(isc_nmsocket_t *sock) {
+	REQUIRE(VALID_NMSOCK(sock));
+
+	if (sock->type == isc_nm_tcpsocket && sock->tcphandle != NULL &&
+	    sock->rcb.recv != NULL)
+	{
+		sock->rcb.recv(sock->tcphandle, ISC_R_CANCELED, NULL,
+			       sock->rcbarg);
+	}
+}
diff --git a/lib/isc/win32/libisc.def.in b/lib/isc/win32/libisc.def.in
index 723c6a95fde..4d6705feec0 100644
--- a/lib/isc/win32/libisc.def.in
+++ b/lib/isc/win32/libisc.def.in
@@ -449,6 +449,7 @@ isc_nmhandle_peeraddr
 isc_nmhandle_ref
 isc_nmhandle_setdata
 isc_nmhandle_unref
+isc_nm_cancelread
 isc_nm_closedown
 isc_nm_destroy
 isc_nm_detach