- Fix readagain and writeagain callback functions for comm point

cleanup.

doc/Changelog

@@ -7,6 +7,8 @@
 	- Fix memory leak for edns client tag opcode config element.
 	- Attempt fix for libevent state in tcp reuse cases after a packet
 	  is written.
+	- Fix readagain and writeagain callback functions for comm point
+	  cleanup.
 
 24 November 2020: Wouter
 	- Merge PR #283 : Stream reuse.  This implements upstream stream

services/outside_network.c

@@ -655,6 +655,10 @@ outnet_tcp_take_into_use(struct waiting_tcp* w)
 	pend->query = w;
 	pend->reuse.outnet = w->outnet;
 	pend->c->repinfo.addrlen = w->addrlen;
+	pend->c->tcp_more_read_again = &pend->reuse.cp_more_read_again;
+	pend->c->tcp_more_write_again = &pend->reuse.cp_more_write_again;
+	pend->reuse.cp_more_read_again = 0;
+	pend->reuse.cp_more_write_again = 0;
 	memcpy(&pend->c->repinfo.addr, &w->addr, w->addrlen);
 	pend->reuse.pending = pend;
 	if(pend->c->ssl)
@@ -804,8 +808,8 @@ reuse_move_writewait_away(struct outside_network* outnet,
 		pend->c->tcp_write_pkt = NULL;
 		pend->c->tcp_write_pkt_len = 0;
 		pend->c->tcp_write_and_read = 0;
-		pend->c->tcp_more_read_again = 0;
+		pend->reuse.cp_more_read_again = 0;
-		pend->c->tcp_more_write_again = 0;
+		pend->reuse.cp_more_write_again = 0;
 		pend->c->tcp_is_reading = 1;
 		w = pend->query;
 		pend->query = NULL;
@@ -1008,7 +1012,7 @@ outnet_tcp_cb(struct comm_point* c, void* arg, int error,
 			 * because this callback called after a tcp write
 			 * succeeded and likely more buffer space is available
 			 * and we can write some more. */
-			pend->c->tcp_more_write_again = 1;
+			pend->reuse.cp_more_write_again = 1;
 			pend->query = reuse_write_wait_pop(&pend->reuse);
 			comm_point_stop_listening(pend->c);
 			outnet_tcp_take_query_setup(pend->c->fd, pend,
@@ -1016,8 +1020,8 @@ outnet_tcp_cb(struct comm_point* c, void* arg, int error,
 		} else {
 			verbose(VERB_ALGO, "outnet tcp writes done, wait");
 			pend->c->tcp_write_and_read = 0;
-			pend->c->tcp_more_read_again = 0;
+			pend->reuse.cp_more_read_again = 0;
-			pend->c->tcp_more_write_again = 0;
+			pend->reuse.cp_more_write_again = 0;
 			pend->c->tcp_is_reading = 1;
 			comm_point_stop_listening(pend->c);
 			reuse_tcp_setup_timeout(pend);
@@ -1072,7 +1076,7 @@ outnet_tcp_cb(struct comm_point* c, void* arg, int error,
 		 * because this callback called after a successful read
 		 * and there could be more bytes to read on the input */
 		if(pend->reuse.tree_by_id.count != 0)
-			pend->c->tcp_more_read_again = 1;
+			pend->reuse.cp_more_read_again = 1;
 		reuse_tcp_setup_read_and_timeout(pend);
 		return 0;
 	}

services/outside_network.h

@@ -266,6 +266,18 @@ struct reuse_tcp {
 	 * or not is also part of the key to the rbtree.
 	 * There is a timeout and read event on the fd, to close it. */
 	struct pending_tcp* pending;
+	/**
+	 * The more read again value pointed to by the commpoint
+	 * tcp_more_read_again pointer, so that it exists after commpoint
+	 * delete
+	 */
+	int cp_more_read_again;
+	/**
+	 * The more write again value pointed to by the commpoint
+	 * tcp_more_write_again pointer, so that it exists after commpoint
+	 * delete
+	 */
+	int cp_more_write_again;
 	/** rbtree with other queries waiting on the connection, by ID number,
 	 * of type struct waiting_tcp. It is for looking up received
 	 * answers to the structure for callback.  And also to see if ID

util/netevent.c

@@ -1056,8 +1056,8 @@ reclaim_tcp_handler(struct comm_point* c)
 			comm_point_start_listening(c->tcp_parent, -1, -1);
 		}
 	}
-	c->tcp_more_read_again = 0;
+	c->tcp_more_read_again = NULL;
-	c->tcp_more_write_again = 0;
+	c->tcp_more_write_again = NULL;
 }
 
 /** do the callback when writing is done */
@@ -1937,8 +1937,9 @@ tcp_more_read_again(int fd, struct comm_point* c)
 	 * the connection, the callback signals this, and we try again */
 	/* this continues until the read routines get EAGAIN or so,
 	 * and thus does not call the callback, and the bool is 0 */
-	while(c->tcp_more_read_again) {
+	int* moreread = c->tcp_more_read_again;
-		c->tcp_more_read_again = 0;
+	while(moreread && *moreread) {
+		*moreread = 0;
 		if(!comm_point_tcp_handle_read(fd, c, 0)) {
 			reclaim_tcp_handler(c);
 			if(!c->tcp_do_close) {
@@ -1960,8 +1961,9 @@ tcp_more_write_again(int fd, struct comm_point* c)
 	 * the callback signals it and we try again. */
 	/* this continues until the write routines get EAGAIN or so,
 	 * and thus does not call the callback, and the bool is 0 */
-	while(c->tcp_more_write_again) {
+	int* morewrite = c->tcp_more_write_again;
-		c->tcp_more_write_again = 0;
+	while(morewrite && *morewrite) {
+		*morewrite = 0;
 		if(!comm_point_tcp_handle_write(fd, c)) {
 			reclaim_tcp_handler(c);
 			if(!c->tcp_do_close) {
@@ -2015,6 +2017,7 @@ comm_point_tcp_handle_callback(int fd, short event, void* arg)
 	}
 	if(event&UB_EV_READ) {
 		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) {
@@ -2026,12 +2029,13 @@ comm_point_tcp_handle_callback(int fd, short event, void* arg)
 		}
 		if(has_tcpq && c->tcp_req_info && c->tcp_req_info->read_again)
 			tcp_req_info_read_again(fd, c);
-		if(c->tcp_more_read_again)
+		if(moreread && *moreread)
 			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) {
@@ -2043,7 +2047,7 @@ comm_point_tcp_handle_callback(int fd, short event, void* arg)
 		}
 		if(has_tcpq && c->tcp_req_info && c->tcp_req_info->read_again)
 			tcp_req_info_read_again(fd, c);
-		if(c->tcp_more_write_again)
+		if(morewrite && *morewrite)
 			tcp_more_write_again(fd, c);
 		return;
 	}

util/netevent.h

@@ -299,13 +299,23 @@ struct comm_point {
 
 	/** if set try to read another packet again (over connection with
 	 * multiple packets), once set, tries once, then zero again,
-	 * so set it in the packet complete section. */
+	 * so set it in the packet complete section.
-	int tcp_more_read_again;
+	 * The pointer itself has to be set before the callback is invoked,
+	 * when you set things up, and continue to exist also after the
+	 * commpoint is closed and deleted in your callback.  So that after
+	 * the callback cleans up netevent can see what it has to do.
+	 * Or leave NULL if it is not used at all. */
+	int* tcp_more_read_again;
 
 	/** if set try to write another packet (over connection with
 	 * multiple packets), once set, tries once, then zero again,
-	 * so set it in the packet complete section. */
+	 * so set it in the packet complete section.
-	int tcp_more_write_again;
+	 * The pointer itself has to be set before the callback is invoked,
+	 * when you set things up, and continue to exist also after the
+	 * commpoint is closed and deleted in your callback.  So that after
+	 * the callback cleans up netevent can see what it has to do.
+	 * Or leave NULL if it is not used at all. */
+	int* tcp_more_write_again;
 
 	/** if set, read/write completes:
 		read/write state of tcp is toggled.