Prevent ospfd from starting if another ospfd is already using the same

socket. The check on the control socket happens early so that the rc
scripts detect a failure.

OK claudio@ florian@

5 files changed, 62 insertions, 17 deletions

diff --git a/usr.sbin/ospfd/control.c b/usr.sbin/ospfd/control.c
index 150c38c9b43..09733bc407e 100644
--- a/usr.sbin/ospfd/control.c
+++ b/usr.sbin/ospfd/control.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: control.c,v 1.44 2017/01/24 04:24:25 benno Exp $ */
+/*	$OpenBSD: control.c,v 1.45 2018/08/29 08:43:16 remi Exp $ */
 
 /*
  * Copyright (c) 2003, 2004 Henning Brauer <henning@openbsd.org>
@@ -39,6 +39,32 @@ struct ctl_conn	*control_connbypid(pid_t);
 void		 control_close(int);
 
 int
+control_check(char *path)
+{
+	struct sockaddr_un	 sun;
+	int			 fd;
+
+	bzero(&sun, sizeof(sun));
+	sun.sun_family = AF_UNIX;
+	strlcpy(sun.sun_path, path, sizeof(sun.sun_path));
+
+	if ((fd = socket(AF_UNIX, SOCK_STREAM, 0)) == -1) {
+		log_warn("control_check: socket check");
+		return (-1);
+	}
+
+	if (connect(fd, (struct sockaddr *)&sun, sizeof(sun)) == 0) {
+		log_warnx("control_check: socket in use");
+		close(fd);
+		return (-1);
+	}
+
+	close(fd);
+
+	return (0);
+}
+
+int
 control_init(char *path)
 {
 	struct sockaddr_un	 sun;
@@ -78,9 +104,7 @@ control_init(char *path)
 		return (-1);
 	}
 
-	control_state.fd = fd;
-
-	return (0);
+	return (fd);
 }
 
 int
diff --git a/usr.sbin/ospfd/control.h b/usr.sbin/ospfd/control.h
index 27abc2278b6..ce2a6d02c1d 100644
--- a/usr.sbin/ospfd/control.h
+++ b/usr.sbin/ospfd/control.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: control.h,v 1.6 2015/02/10 05:24:48 claudio Exp $ */
+/*	$OpenBSD: control.h,v 1.7 2018/08/29 08:43:16 remi Exp $ */
 
 /*
  * Copyright (c) 2003, 2004 Henning Brauer <henning@openbsd.org>
@@ -34,6 +34,7 @@ struct ctl_conn {
 	struct imsgev		iev;
 };
 
+int	control_check(char *);
 int	control_init(char *);
 int	control_listen(void);
 void	control_accept(int, short, void *);
diff --git a/usr.sbin/ospfd/ospfd.c b/usr.sbin/ospfd/ospfd.c
index 378bc2bfbb0..df80b65733e 100644
--- a/usr.sbin/ospfd/ospfd.c
+++ b/usr.sbin/ospfd/ospfd.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: ospfd.c,v 1.99 2018/07/11 12:09:34 remi Exp $ */
+/*	$OpenBSD: ospfd.c,v 1.100 2018/08/29 08:43:17 remi Exp $ */
 
 /*
  * Copyright (c) 2005 Claudio Jeker <claudio@openbsd.org>
@@ -116,6 +116,7 @@ main(int argc, char *argv[])
 	int			 mib[4];
 	size_t			 len;
 	char			*sockname = NULL;
+	int			 control_fd;
 
 	conffile = CONF_FILE;
 	ospfd_process = PROC_MAIN;
@@ -213,6 +214,9 @@ main(int argc, char *argv[])
 	log_init(debug, LOG_DAEMON);
 	log_setverbose(ospfd_conf->opts & OSPFD_OPT_VERBOSE);
 
+	if ((control_check(ospfd_conf->csock)) == -1)
+		fatalx("control socket check failed");
+
 	if (!debug)
 		daemon(1, 0);
 
@@ -270,6 +274,10 @@ main(int argc, char *argv[])
 	    iev_rde->handler, iev_rde);
 	event_add(&iev_rde->ev, NULL);
 
+	if ((control_fd = control_init(ospfd_conf->csock)) == -1)
+		fatalx("control socket setup failed");
+	main_imsg_compose_ospfe_fd(IMSG_CONTROLFD, 0, control_fd);
+
 	if (kr_init(!(ospfd_conf->flags & OSPFD_FLAG_NO_FIB_UPDATE),
 	    ospfd_conf->rdomain, ospfd_conf->redist_label_or_prefix) == -1)
 		fatalx("kr_init failed");
@@ -486,6 +494,13 @@ main_imsg_compose_ospfe(int type, pid_t pid, void *data, u_int16_t datalen)
 }
 
 void
+main_imsg_compose_ospfe_fd(int type, pid_t pid, int fd)
+{
+	if (iev_ospfe)
+		imsg_compose_event(iev_ospfe, type, 0, pid, fd, NULL, 0);
+}
+
+void
 main_imsg_compose_rde(int type, pid_t pid, void *data, u_int16_t datalen)
 {
 	if (iev_rde)
diff --git a/usr.sbin/ospfd/ospfd.h b/usr.sbin/ospfd/ospfd.h
index 1b772a4acdc..3e8a5af4ab2 100644
--- a/usr.sbin/ospfd/ospfd.h
+++ b/usr.sbin/ospfd/ospfd.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: ospfd.h,v 1.101 2018/06/25 22:16:53 remi Exp $ */
+/*	$OpenBSD: ospfd.h,v 1.102 2018/08/29 08:43:17 remi Exp $ */
 
 /*
  * Copyright (c) 2004 Esben Norby <norby@openbsd.org>
@@ -101,6 +101,7 @@ enum imsg_type {
 	IMSG_CTL_IFINFO,
 	IMSG_CTL_END,
 	IMSG_CTL_LOG_VERBOSE,
+	IMSG_CONTROLFD,
 	IMSG_KROUTE_CHANGE,
 	IMSG_KROUTE_DELETE,
 	IMSG_IFINFO,
@@ -605,6 +606,7 @@ void		 rtlabel_tag(u_int16_t, u_int32_t);
 
 /* ospfd.c */
 void	main_imsg_compose_ospfe(int, pid_t, void *, u_int16_t);
+void	main_imsg_compose_ospfe_fd(int, pid_t, int);
 void	main_imsg_compose_rde(int, pid_t, void *, u_int16_t);
 int	ospf_redistribute(struct kroute *, u_int32_t *);
 void	merge_config(struct ospfd_conf *, struct ospfd_conf *);
diff --git a/usr.sbin/ospfd/ospfe.c b/usr.sbin/ospfd/ospfe.c
index d222670208b..b57ae6941e5 100644
--- a/usr.sbin/ospfd/ospfe.c
+++ b/usr.sbin/ospfd/ospfe.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: ospfe.c,v 1.101 2018/06/25 22:16:53 remi Exp $ */
+/*	$OpenBSD: ospfe.c,v 1.102 2018/08/29 08:43:17 remi Exp $ */
 
 /*
  * Copyright (c) 2005 Claudio Jeker <claudio@openbsd.org>
@@ -90,10 +90,6 @@ ospfe(struct ospfd_conf *xconf, int pipe_parent2ospfe[2], int pipe_ospfe2rde[2],
 	/* cleanup a bit */
 	kif_clear();
 
-	/* create ospfd control socket outside chroot */
-	if (control_init(xconf->csock) == -1)
-		fatalx("control socket setup failed");
-
 	/* create the raw ip socket */
 	if ((xconf->ospf_socket = socket(AF_INET,
 	    SOCK_RAW | SOCK_CLOEXEC | SOCK_NONBLOCK,
@@ -136,7 +132,7 @@ ospfe(struct ospfd_conf *xconf, int pipe_parent2ospfe[2], int pipe_ospfe2rde[2],
 	    setresuid(pw->pw_uid, pw->pw_uid, pw->pw_uid))
 		fatal("can't drop privileges");
 
-	if (pledge("stdio inet mcast", NULL) == -1)
+	if (pledge("stdio inet mcast recvfd", NULL) == -1)
 		fatal("pledge");
 
 	event_init();
@@ -189,10 +185,6 @@ ospfe(struct ospfd_conf *xconf, int pipe_parent2ospfe[2], int pipe_ospfe2rde[2],
 		}
 	}
 
-	/* listen on ospfd control socket */
-	TAILQ_INIT(&ctl_conns);
-	control_listen();
-
 	if ((pkt_ptr = calloc(1, READ_BUF_SIZE)) == NULL)
 		fatal("ospfe");
 
@@ -465,6 +457,17 @@ ospfe_dispatch_main(int fd, short event, void *bula)
 		case IMSG_CTL_END:
 			control_imsg_relay(&imsg);
 			break;
+		case IMSG_CONTROLFD:
+			if ((fd = imsg.fd) == -1)
+				fatalx("%s: expected to receive imsg control"
+				    "fd but didn't receive any", __func__);
+			control_state.fd = fd;
+			/* Listen on control socket. */
+			TAILQ_INIT(&ctl_conns);
+			control_listen();
+			if (pledge("stdio inet mcast", NULL) == -1)
+                		fatal("pledge");
+			break;
 		default:
 			log_debug("ospfe_dispatch_main: error handling imsg %d",
 			    imsg.hdr.type);