bgpctl can cause bgpd to do a lot of work (e.g. dumping all of the RIB)

but then bgpctl can quickly exit and bgpd still has to do all the work.
Instead introduce a terminate imsg to stop such long running commands if
bgpctl closes the connection before the run is over.
OK benno@, sthen@, deraadt@

4 files changed, 55 insertions, 11 deletions

diff --git a/usr.sbin/bgpd/bgpd.h b/usr.sbin/bgpd/bgpd.h
index fd4e9484f2a..7f981155023 100644
--- a/usr.sbin/bgpd/bgpd.h
+++ b/usr.sbin/bgpd/bgpd.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: bgpd.h,v 1.358 2018/12/19 15:26:42 claudio Exp $ */
+/*	$OpenBSD: bgpd.h,v 1.359 2018/12/22 16:12:40 claudio Exp $ */
 
 /*
  * Copyright (c) 2003, 2004 Henning Brauer <henning@openbsd.org>
@@ -437,6 +437,7 @@ enum imsg_type {
 	IMSG_CTL_SHOW_TIMER,
 	IMSG_CTL_LOG_VERBOSE,
 	IMSG_CTL_SHOW_FIB_TABLES,
+	IMSG_CTL_TERMINATE,
 	IMSG_NETWORK_ADD,
 	IMSG_NETWORK_ASPATH,
 	IMSG_NETWORK_ATTR,
diff --git a/usr.sbin/bgpd/control.c b/usr.sbin/bgpd/control.c
index 3ba8ed1c86d..0e2b1813eb8 100644
--- a/usr.sbin/bgpd/control.c
+++ b/usr.sbin/bgpd/control.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: control.c,v 1.91 2018/11/28 08:32:27 claudio Exp $ */
+/*	$OpenBSD: control.c,v 1.92 2018/12/22 16:12:40 claudio Exp $ */
 
 /*
  * Copyright (c) 2003, 2004 Henning Brauer <henning@openbsd.org>
@@ -188,6 +188,9 @@ control_close(int fd)
 		return (0);
 	}
 
+	if (c->terminate && c->ibuf.pid)
+		imsg_ctl_rde(IMSG_CTL_TERMINATE, c->ibuf.pid, NULL, 0);
+
 	msgbuf_clear(&c->ibuf.w);
 	TAILQ_REMOVE(&ctl_conns, c, entry);
 
@@ -247,12 +250,12 @@ control_dispatch_msg(struct pollfd *pfd, u_int *ctl_cnt)
 			case IMSG_CTL_SHOW_NEIGHBOR:
 			case IMSG_CTL_SHOW_NEXTHOP:
 			case IMSG_CTL_SHOW_INTERFACE:
-			case IMSG_CTL_SHOW_RIB:
-			case IMSG_CTL_SHOW_RIB_PREFIX:
 			case IMSG_CTL_SHOW_RIB_MEM:
-			case IMSG_CTL_SHOW_NETWORK:
 			case IMSG_CTL_SHOW_TERSE:
 			case IMSG_CTL_SHOW_TIMER:
+			case IMSG_CTL_SHOW_NETWORK:
+			case IMSG_CTL_SHOW_RIB:
+			case IMSG_CTL_SHOW_RIB_PREFIX:
 				break;
 			default:
 				/* clear imsg type to prevent processing */
@@ -459,14 +462,17 @@ control_dispatch_msg(struct pollfd *pfd, u_int *ctl_cnt)
 					break;
 				}
 				c->ibuf.pid = imsg.hdr.pid;
+				c->terminate = 1;
 				imsg_ctl_rde(imsg.hdr.type, imsg.hdr.pid,
 				    imsg.data, imsg.hdr.len - IMSG_HEADER_SIZE);
 			} else
 				log_warnx("got IMSG_CTL_SHOW_RIB with "
 				    "wrong length");
 			break;
-		case IMSG_CTL_SHOW_RIB_MEM:
 		case IMSG_CTL_SHOW_NETWORK:
+			c->terminate = 1;
+			/* FALLTHROUGH */
+		case IMSG_CTL_SHOW_RIB_MEM:
 			c->ibuf.pid = imsg.hdr.pid;
 			imsg_ctl_rde(imsg.hdr.type, imsg.hdr.pid,
 			    imsg.data, imsg.hdr.len - IMSG_HEADER_SIZE);
@@ -512,6 +518,10 @@ control_imsg_relay(struct imsg *imsg)
 	if ((c = control_connbypid(imsg->hdr.pid)) == NULL)
 		return (0);
 
+	/* if command finished no need to send exit message */
+	if (imsg->hdr.type == IMSG_CTL_END || imsg->hdr.type == IMSG_CTL_RESULT)
+		c->terminate = 0;
+
 	if (!c->throttled && c->ibuf.w.queued > CTL_MSG_HIGH_MARK) {
 		if (imsg_ctl_rde(IMSG_XOFF, imsg->hdr.pid, NULL, 0) != -1)
 			c->throttled = 1;
diff --git a/usr.sbin/bgpd/rde.c b/usr.sbin/bgpd/rde.c
index 7b183cb9670..01b47a6aac5 100644
--- a/usr.sbin/bgpd/rde.c
+++ b/usr.sbin/bgpd/rde.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: rde.c,v 1.453 2018/12/19 15:26:42 claudio Exp $ */
+/*	$OpenBSD: rde.c,v 1.454 2018/12/22 16:12:40 claudio Exp $ */
 
 /*
  * Copyright (c) 2003, 2004 Henning Brauer <henning@openbsd.org>
@@ -71,7 +71,8 @@ void		 rde_reflector(struct rde_peer *, struct rde_aspath *);
 
 void		 rde_dump_ctx_new(struct ctl_show_rib_request *, pid_t,
 		     enum imsg_type);
-void		 rde_dump_ctx_throttle(pid_t pid, int throttle);
+void		 rde_dump_ctx_throttle(pid_t, int);
+void		 rde_dump_ctx_terminate(pid_t);
 void		 rde_dump_mrt_new(struct mrt *, pid_t, int);
 
 int		 rde_rdomain_import(struct rde_aspath *, struct rdomain *);
@@ -133,7 +134,7 @@ int			 softreconfig;
 struct rde_dump_ctx {
 	LIST_ENTRY(rde_dump_ctx)	entry;
 	struct ctl_show_rib_request	req;
-	sa_family_t			af;
+	u_int16_t			rid;
 	u_int8_t			throttled;
 };
 
@@ -658,6 +659,9 @@ badnetdel:
 				rde_dump_ctx_throttle(imsg.hdr.pid, 1);
 			}
 			break;
+		case IMSG_CTL_TERMINATE:
+			rde_dump_ctx_terminate(imsg.hdr.pid);
+			break;
 		default:
 			break;
 		}
@@ -2321,6 +2325,7 @@ rde_dump_ctx_new(struct ctl_show_rib_request *req, pid_t pid,
 	memcpy(&ctx->req, req, sizeof(struct ctl_show_rib_request));
 	ctx->req.pid = pid;
 	ctx->req.type = type;
+	ctx->rid = rid;
 	switch (ctx->req.type) {
 	case IMSG_CTL_SHOW_NETWORK:
 		if (rib_dump_new(rid, ctx->req.aid, CTL_MSG_HIGH_MARK, ctx,
@@ -2364,7 +2369,7 @@ rde_dump_ctx_new(struct ctl_show_rib_request *req, pid_t pid,
 		free(ctx);
 		return;
 	default:
-		fatalx("rde_dump_ctx_new: unsupported imsg type");
+		fatalx("%s: unsupported imsg type", __func__);
 	}
 	LIST_INSERT_HEAD(&rde_dump_h, ctx, entry);
 }
@@ -2382,6 +2387,33 @@ rde_dump_ctx_throttle(pid_t pid, int throttle)
 	}
 }
 
+void
+rde_dump_ctx_terminate(pid_t pid)
+{
+	struct rde_dump_ctx	*ctx;
+
+	LIST_FOREACH(ctx, &rde_dump_h, entry) {
+		if (ctx->req.pid == pid) {
+			void (*upcall)(struct rib_entry *, void *);
+			switch (ctx->req.type) {
+			case IMSG_CTL_SHOW_NETWORK:
+				upcall = network_dump_upcall;
+				break;
+			case IMSG_CTL_SHOW_RIB:
+				upcall = rde_dump_upcall;
+				break;
+			case IMSG_CTL_SHOW_RIB_PREFIX:
+				upcall = rde_dump_prefix_upcall;
+				break;
+			default:
+				fatalx("%s: unsupported imsg type", __func__);
+			}
+			rib_dump_terminate(ctx->rid, ctx, upcall);
+			return;
+		}
+	}
+}
+
 static int
 rde_mrt_throttled(void *arg)
 {
diff --git a/usr.sbin/bgpd/session.h b/usr.sbin/bgpd/session.h
index 17b1b4529ea..1c87025d7ef 100644
--- a/usr.sbin/bgpd/session.h
+++ b/usr.sbin/bgpd/session.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: session.h,v 1.125 2018/10/24 08:26:37 claudio Exp $ */
+/*	$OpenBSD: session.h,v 1.126 2018/12/22 16:12:40 claudio Exp $ */
 
 /*
  * Copyright (c) 2003, 2004 Henning Brauer <henning@openbsd.org>
@@ -143,6 +143,7 @@ struct ctl_conn {
 	struct imsgbuf		ibuf;
 	int			restricted;
 	int			throttled;
+	int			terminate;
 };
 
 TAILQ_HEAD(ctl_conns, ctl_conn)	ctl_conns;