allow to add an additional restricted control socket for trap sending

only (not even show commands).  this allows to place a socket for
traps in another daemon's chroot.

(based on restricted socket support from bgpd)

7 files changed, 107 insertions, 52 deletions

diff --git a/usr.sbin/snmpctl/snmpctl.8 b/usr.sbin/snmpctl/snmpctl.8
index ed46d31fde6..d04e0a7599a 100644
--- a/usr.sbin/snmpctl/snmpctl.8
+++ b/usr.sbin/snmpctl/snmpctl.8
@@ -1,4 +1,4 @@
-.\" $OpenBSD: snmpctl.8,v 1.8 2008/05/17 23:31:52 sobrado Exp $
+.\" $OpenBSD: snmpctl.8,v 1.9 2008/09/26 15:19:55 reyk Exp $
 .\"
 .\" Copyright (c) 2007, 2008 Reyk Floeter <reyk@vantronix.net>
 .\"
@@ -14,7 +14,7 @@
 .\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 .\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 .\"
-.Dd $Mdocdate: May 17 2008 $
+.Dd $Mdocdate: September 26 2008 $
 .Dt SNMPCTL 8
 .Os
 .Sh NAME
@@ -23,6 +23,7 @@
 .Sh SYNOPSIS
 .Nm
 .Op Fl n
+.Op Fl s Ar socket
 .Ar command
 .Op Ar arg ...
 .Sh DESCRIPTION
@@ -36,6 +37,13 @@ The options are as follows:
 .Bl -tag -width Ds
 .It Fl n
 Show numeric OID values instead of their symbolic names.
+.It Fl s Ar socket
+Use
+.Ar socket
+instead of the default
+.Pa /var/run/snmpd.sock
+to communicate with
+.Xr snmpd 8 .
 .El
 .Pp
 The following commands are available:
@@ -97,8 +105,8 @@ An string describing an Object ID, for example
 .Sh FILES
 .Bl -tag -width "/var/run/snmpd.sockXX" -compact
 .It /var/run/snmpd.sock
-Unix-domain socket used for communication with
-.Xr snmpd 8 .
+default UNIX-domain socket used for communication with
+.Xr snmpd 8
 .El
 .Sh SEE ALSO
 .Xr snmpd 8
diff --git a/usr.sbin/snmpctl/snmpctl.c b/usr.sbin/snmpctl/snmpctl.c
index 41a8f3d9efb..89210679866 100644
--- a/usr.sbin/snmpctl/snmpctl.c
+++ b/usr.sbin/snmpctl/snmpctl.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: snmpctl.c,v 1.8 2008/05/17 23:31:52 sobrado Exp $	*/
+/*	$OpenBSD: snmpctl.c,v 1.9 2008/09/26 15:19:55 reyk Exp $	*/
 
 /*
  * Copyright (c) 2007, 2008 Reyk Floeter <reyk@vantronix.net>
@@ -95,16 +95,20 @@ main(int argc, char *argv[])
 	int			 done = 0;
 	int			 n;
 	int			 ch;
+	const char		*sock = SNMPD_SOCKET;
 
 	if ((env = calloc(1, sizeof(struct snmpd *))) == NULL)
 		err(1, "calloc");
 	gettimeofday(&env->sc_starttime, NULL);
 
-	while ((ch = getopt(argc, argv, "n")) != -1) {
+	while ((ch = getopt(argc, argv, "ns:")) != -1) {
 		switch (ch) {
 		case 'n':
 			env->sc_flags |= SNMPD_F_NONAMES;
 			break;
+		case 's':
+			sock = optarg;
+			break;
 		default:
 			usage();
 			/* NOTREACHED */
@@ -140,7 +144,7 @@ main(int argc, char *argv[])
 
 	bzero(&sun, sizeof(sun));
 	sun.sun_family = AF_UNIX;
-	strlcpy(sun.sun_path, SNMPD_SOCKET, sizeof(sun.sun_path));
+	strlcpy(sun.sun_path, sock, sizeof(sun.sun_path));
  reconnect:
 	if (connect(ctl_sock, (struct sockaddr *)&sun, sizeof(sun)) == -1) {
 		/* Keep retrying if running in monitor mode */
@@ -149,7 +153,7 @@ main(int argc, char *argv[])
 			usleep(100);
 			goto reconnect;
 		}
-		err(1, "connect: %s", SNMPD_SOCKET);
+		err(1, "connect: %s", sock);
 	}
 
 	if (res->ibuf != NULL)
diff --git a/usr.sbin/snmpd/control.c b/usr.sbin/snmpd/control.c
index 646d181d126..bde9dd16ef9 100644
--- a/usr.sbin/snmpd/control.c
+++ b/usr.sbin/snmpd/control.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: control.c,v 1.7 2008/02/07 11:33:26 reyk Exp $	*/
+/*	$OpenBSD: control.c,v 1.8 2008/09/26 15:19:55 reyk Exp $	*/
 
 /*
  * Copyright (c) 2003, 2004 Henning Brauer <henning@openbsd.org>
@@ -43,14 +43,15 @@ struct ctl_connlist ctl_conns;
 struct ctl_conn	*control_connbyfd(int);
 void		 control_close(int);
 
-struct imsgbuf	*ibuf_parent = NULL;
-
 int
-control_init(void)
+control_init(struct control_sock *cs)
 {
 	struct sockaddr_un	 sun;
 	int			 fd;
-	mode_t			 old_umask;
+	mode_t			 old_umask, mode;
+
+	if (cs->cs_name == NULL)
+		return (0);
 
 	if ((fd = socket(AF_UNIX, SOCK_STREAM, 0)) == -1) {
 		log_warn("control_init: socket");
@@ -58,74 +59,84 @@ control_init(void)
 	}
 
 	sun.sun_family = AF_UNIX;
-	if (strlcpy(sun.sun_path, SNMPD_SOCKET,
+	if (strlcpy(sun.sun_path, cs->cs_name,
 	    sizeof(sun.sun_path)) >= sizeof(sun.sun_path)) {
-		log_warn("control_init: %s name too long", SNMPD_SOCKET);
+		log_warn("control_init: %s name too long", cs->cs_name);
 		close(fd);
 		return (-1);
 	}
 
-	if (unlink(SNMPD_SOCKET) == -1)
+	if (unlink(cs->cs_name) == -1)
 		if (errno != ENOENT) {
-			log_warn("control_init: unlink %s", SNMPD_SOCKET);
+			log_warn("control_init: unlink %s", cs->cs_name);
 			close(fd);
 			return (-1);
 		}
 
-	old_umask = umask(S_IXUSR|S_IXGRP|S_IWOTH|S_IROTH|S_IXOTH);
+	if (cs->cs_restricted) {
+		old_umask = umask(S_IXUSR|S_IXGRP|S_IXOTH);
+		mode = S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP|S_IROTH|S_IWOTH;
+	} else {
+		old_umask = umask(S_IXUSR|S_IXGRP|S_IWOTH|S_IROTH|S_IXOTH);
+		mode = S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP;
+	}
+
 	if (bind(fd, (struct sockaddr *)&sun, sizeof(sun)) == -1) {
-		log_warn("control_init: bind: %s", SNMPD_SOCKET);
+		log_warn("control_init: bind: %s", cs->cs_name);
 		close(fd);
 		(void)umask(old_umask);
 		return (-1);
 	}
 	(void)umask(old_umask);
 
-	if (chmod(SNMPD_SOCKET, S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP) == -1) {
+	if (chmod(cs->cs_name, mode) == -1) {
 		log_warn("control_init: chmod");
 		close(fd);
-		(void)unlink(SNMPD_SOCKET);
+		(void)unlink(cs->cs_name);
 		return (-1);
 	}
 
 	session_socket_blockmode(fd, BM_NONBLOCK);
-	control_state.fd = fd;
+	cs->cs_fd = fd;
 
 	return (0);
 }
 
 int
-control_listen(struct snmpd *env, struct imsgbuf *parent)
+control_listen(struct control_sock *cs)
 {
-	ibuf_parent = parent;
+	if (cs->cs_name == NULL)
+		return (0);
 
-	if (listen(control_state.fd, CONTROL_BACKLOG) == -1) {
+	if (listen(cs->cs_fd, CONTROL_BACKLOG) == -1) {
 		log_warn("control_listen: listen");
 		return (-1);
 	}
 
-	event_set(&control_state.ev, control_state.fd, EV_READ | EV_PERSIST,
-	    control_accept, env);
-	event_add(&control_state.ev, NULL);
+	event_set(&cs->cs_ev, cs->cs_fd, EV_READ | EV_PERSIST,
+	    control_accept, cs);
+	event_add(&cs->cs_ev, NULL);
 
 	return (0);
 }
 
 void
-control_cleanup(void)
+control_cleanup(struct control_sock *cs)
 {
-	(void)unlink(SNMPD_SOCKET);
+	if (cs->cs_name == NULL)
+		return;
+	(void)unlink(cs->cs_name);
 }
 
 /* ARGSUSED */
 void
 control_accept(int listenfd, short event, void *arg)
 {
+	struct control_sock	*cs = (struct control_sock *)arg;
 	int			 connfd;
 	socklen_t		 len;
 	struct sockaddr_un	 sun;
 	struct ctl_conn		*c;
-	struct snmpd		*env = arg;
 
 	len = sizeof(sun);
 	if ((connfd = accept(listenfd,
@@ -146,7 +157,7 @@ control_accept(int listenfd, short event, void *arg)
 	imsg_init(&c->ibuf, connfd, control_dispatch_imsg);
 	c->ibuf.events = EV_READ;
 	event_set(&c->ibuf.ev, c->ibuf.fd, c->ibuf.events,
-	    c->ibuf.handler, env);
+	    c->ibuf.handler, cs);
 	event_add(&c->ibuf.ev, NULL);
 
 	TAILQ_INSERT_TAIL(&ctl_conns, c, entry);
@@ -184,6 +195,7 @@ control_close(int fd)
 void
 control_dispatch_imsg(int fd, short event, void *arg)
 {
+	struct control_sock	*cs = (struct control_sock *)arg;
 	struct ctl_conn		*c;
 	struct imsg		 imsg;
 	int			 n;
@@ -220,7 +232,7 @@ control_dispatch_imsg(int fd, short event, void *arg)
 		if (n == 0)
 			break;
 
-		if (c->flags & CTL_CONN_LOCKED) {
+		if (cs->cs_restricted || (c->flags & CTL_CONN_LOCKED)) {
 			switch (imsg.hdr.type) {
 			case IMSG_SNMP_TRAP:
 			case IMSG_SNMP_ELEMENT:
diff --git a/usr.sbin/snmpd/snmpd.8 b/usr.sbin/snmpd/snmpd.8
index 94611664dea..3b93e946828 100644
--- a/usr.sbin/snmpd/snmpd.8
+++ b/usr.sbin/snmpd/snmpd.8
@@ -1,4 +1,4 @@
-.\" $OpenBSD: snmpd.8,v 1.8 2008/03/30 17:56:27 martin Exp $
+.\" $OpenBSD: snmpd.8,v 1.9 2008/09/26 15:19:55 reyk Exp $
 .\"
 .\" Copyright (c) 2007, 2008 Reyk Floeter <reyk@vantronix.net>
 .\"
@@ -14,7 +14,7 @@
 .\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 .\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 .\"
-.Dd $Mdocdate: March 30 2008 $
+.Dd $Mdocdate: September 26 2008 $
 .Dt SNMPD 8
 .Os
 .Sh NAME
@@ -27,6 +27,7 @@
 .Fl D Ar macro Ns = Ns Ar value Oc
 .Xc
 .Op Fl f Ar file
+.Op Fl r Ar path
 .Sh DESCRIPTION
 .Nm
 is a daemon which implements the SNMP protocol.
@@ -55,15 +56,26 @@ Show numeric OID values instead of their symbolic names.
 .It Fl n
 Configtest mode.
 Only check the configuration file for validity.
+.It Fl r Ar path
+Open a second, restricted, control socket that
+.Xr snmpctl 8
+can use.
+Only
+.Em trap
+requests are allowed on this socket.
 .It Fl v
 Produce more verbose output.
 .El
 .Sh FILES
-.Bl -tag -width "/etc/snmpd.confXXX" -compact
+.Bl -tag -width "/var/run/snmpd.sockXXX" -compact
 .It Pa /etc/snmpd.conf
 default
 .Nm
 configuration file
+.It Pa /var/run/snmpd.sock
+default
+.Nm
+control socket
 .El
 .Sh SEE ALSO
 .Xr snmpd.conf 5 ,
diff --git a/usr.sbin/snmpd/snmpd.c b/usr.sbin/snmpd/snmpd.c
index 4835b92a6f1..fad785ecabf 100644
--- a/usr.sbin/snmpd/snmpd.c
+++ b/usr.sbin/snmpd/snmpd.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: snmpd.c,v 1.7 2008/05/12 19:15:02 pyr Exp $	*/
+/*	$OpenBSD: snmpd.c,v 1.8 2008/09/26 15:19:55 reyk Exp $	*/
 
 /*
  * Copyright (c) 2007, 2008 Reyk Floeter <reyk@vantronix.net>
@@ -84,8 +84,8 @@ usage(void)
 {
 	extern char	*__progname;
 
-	fprintf(stderr, "usage: %s [-dNnv] [-D macro=value] [-f file]\n",
-	    __progname);
+	fprintf(stderr, "usage: %s [-dNnv] [-D macro=value] "
+	    "[-f file] [-r path]\n", __progname);
 	exit(1);
 }
 
@@ -102,12 +102,13 @@ main(int argc, char *argv[])
 	u_int			 flags = 0;
 	int			 noaction = 0;
 	const char		*conffile = CONF_FILE;
+	const char		*rcsock = NULL;
 
 	smi_init();
 
 	log_init(1);	/* log to stderr until daemonized */
 
-	while ((c = getopt(argc, argv, "dD:nNf:v")) != -1) {
+	while ((c = getopt(argc, argv, "dD:nNf:r:v")) != -1) {
 		switch (c) {
 		case 'd':
 			debug = 1;
@@ -126,6 +127,9 @@ main(int argc, char *argv[])
 		case 'f':
 			conffile = optarg;
 			break;
+		case 'r':
+			rcsock = optarg;
+			break;
 		case 'v':
 			flags |= SNMPD_F_VERBOSE;
 			break;
@@ -154,6 +158,11 @@ main(int argc, char *argv[])
 	if (getpwnam(SNMPD_USER) == NULL)
 		errx(1, "unknown user %s", SNMPD_USER);
 
+	/* Configure the control sockets */
+	env->sc_csock.cs_name = SNMPD_SOCKET;
+	env->sc_rcsock.cs_name = rcsock;
+	env->sc_rcsock.cs_restricted = 1;
+
 	log_init(debug);
 
 	if (!debug) {
@@ -218,7 +227,8 @@ snmpd_shutdown(struct snmpd *env)
 			fatal("wait");
 	} while (pid != -1 || (pid == -1 && errno == EINTR));
 
-	control_cleanup();
+	control_cleanup(&env->sc_csock);
+	control_cleanup(&env->sc_rcsock);
 	log_info("terminating");
 	exit(0);
 }
diff --git a/usr.sbin/snmpd/snmpd.h b/usr.sbin/snmpd/snmpd.h
index 16969ebf1dd..36960ba50a3 100644
--- a/usr.sbin/snmpd/snmpd.h
+++ b/usr.sbin/snmpd/snmpd.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: snmpd.h,v 1.20 2008/07/18 12:30:06 reyk Exp $	*/
+/*	$OpenBSD: snmpd.h,v 1.21 2008/09/26 15:19:55 reyk Exp $	*/
 
 /*
  * Copyright (c) 2007, 2008 Reyk Floeter <reyk@vantronix.net>
@@ -118,10 +118,12 @@ enum {
 } snmpd_process;
 
 /* initially control.h */
-struct {
-	struct event	 ev;
-	int		 fd;
-} control_state;
+struct control_sock {
+	const char	*cs_name;
+	struct event	 cs_ev;
+	int		 cs_fd;
+	int		 cs_restricted;
+};
 
 enum blockmodes {
 	BM_NORMAL,
@@ -322,6 +324,9 @@ struct snmpd {
 	struct event		 sc_ev;
 	struct timeval		 sc_starttime;
 
+	struct control_sock	 sc_csock;
+	struct control_sock	 sc_rcsock;
+
 	char			 sc_rdcommunity[SNMPD_MAXCOMMUNITYLEN];
 	char			 sc_rwcommunity[SNMPD_MAXCOMMUNITYLEN];
 	char			 sc_trcommunity[SNMPD_MAXCOMMUNITYLEN];
@@ -332,12 +337,12 @@ struct snmpd {
 };
 
 /* control.c */
-int		 control_init(void);
-int		 control_listen(struct snmpd *, struct imsgbuf *);
+int		 control_init(struct control_sock *);
+int		 control_listen(struct control_sock *);
 void		 control_accept(int, short, void *);
 void		 control_dispatch_imsg(int, short, void *);
 void		 control_imsg_forward(struct imsg *);
-void		 control_cleanup(void);
+void		 control_cleanup(struct control_sock *);
 
 void		 session_socket_blockmode(int, enum blockmodes);
 
diff --git a/usr.sbin/snmpd/snmpe.c b/usr.sbin/snmpd/snmpe.c
index 37f4b6d9901..62623104f70 100644
--- a/usr.sbin/snmpd/snmpe.c
+++ b/usr.sbin/snmpd/snmpe.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: snmpe.c,v 1.20 2008/09/03 13:41:49 jsg Exp $	*/
+/*	$OpenBSD: snmpe.c,v 1.21 2008/09/26 15:19:55 reyk Exp $	*/
 
 /*
  * Copyright (c) 2007, 2008 Reyk Floeter <reyk@vantronix.net>
@@ -88,8 +88,10 @@ snmpe(struct snmpd *x_env, int pipe_parent2snmpe[2])
 
 	env = x_env;
 
-	if (control_init() == -1)
+	if (control_init(&env->sc_csock) == -1)
 		fatalx("snmpe: control socket setup failed");
+	if (control_init(&env->sc_rcsock) == -1)
+		fatalx("snmpe: restricted control socket setup failed");
 
 	if ((env->sc_sock = snmpe_bind(&env->sc_address)) == -1)
 		fatalx("snmpe: failed to bind SNMP UDP socket");
@@ -147,8 +149,10 @@ snmpe(struct snmpd *x_env, int pipe_parent2snmpe[2])
 
 	TAILQ_INIT(&ctl_conns);
 
-	if (control_listen(env, ibuf_parent) == -1)
+	if (control_listen(&env->sc_csock) == -1)
 		fatalx("snmpe: control socket listen failed");
+	if (control_listen(&env->sc_rcsock) == -1)
+		fatalx("snmpe: restricted control socket listen failed");
 
 	event_set(&env->sc_ev, env->sc_sock, EV_READ|EV_PERSIST,
 	    snmpe_recvmsg, env);