Add "iscsictl -e". Among other things, it makes it possible to perform

discovery without attaching to the targets ("iscsictl -Ad ... -e off"),
and then attach to selected ones ("iscsictl -Mi ... -e on").

PR:		204129
MFC after:	1 month
Relnotes:	yes
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D6633

sys/dev/iscsi/iscsi.c

@@ -406,6 +406,11 @@ iscsi_maintenance_thread_reconnect(struct iscsi_session *is)
 	KASSERT(STAILQ_EMPTY(&is->is_postponed),
 	    ("destroying session with postponed PDUs"));
 
+	if (is->is_conf.isc_enable == 0 && is->is_conf.isc_discovery == 0) {
+		ISCSI_SESSION_UNLOCK(is);
+		return;
+	}
+
 	/*
 	 * Request immediate reconnection from iscsid(8).
 	 */
@@ -549,6 +554,9 @@ iscsi_callout(void *context)
 
 	callout_schedule(&is->is_callout, 1 * hz);
 
+	if (is->is_conf.isc_enable == 0)
+		goto out;
+
 	is->is_timeout++;
 
 	if (is->is_waiting_for_iscsid) {
@@ -1311,6 +1319,11 @@ iscsi_ioctl_daemon_wait(struct iscsi_softc *sc,
 	for (;;) {
 		TAILQ_FOREACH(is, &sc->sc_sessions, is_next) {
 			ISCSI_SESSION_LOCK(is);
+			if (is->is_conf.isc_enable == 0 &&
+			    is->is_conf.isc_discovery == 0) {
+				ISCSI_SESSION_UNLOCK(is);
+				continue;
+			}
 			if (is->is_waiting_for_iscsid)
 				break;
 			ISCSI_SESSION_UNLOCK(is);
@@ -1826,17 +1839,22 @@ iscsi_ioctl_session_add(struct iscsi_softc *sc, struct iscsi_session_add *isa)
 	callout_reset(&is->is_callout, 1 * hz, iscsi_callout, is);
 	TAILQ_INSERT_TAIL(&sc->sc_sessions, is, is_next);
 
-	/*
-	 * Trigger immediate reconnection.
-	 */
 	ISCSI_SESSION_LOCK(is);
+	/*
+	 * Don't notify iscsid(8) if the session is disabled and it's not
+	 * a discovery session,
+	 */
+	if (is->is_conf.isc_enable == 0 && is->is_conf.isc_discovery == 0) {
+		ISCSI_SESSION_UNLOCK(is);
+		sx_xunlock(&sc->sc_lock);
+		return (0);
+	}
+
 	is->is_waiting_for_iscsid = true;
 	strlcpy(is->is_reason, "Waiting for iscsid(8)", sizeof(is->is_reason));
 	ISCSI_SESSION_UNLOCK(is);
 	cv_signal(&sc->sc_cv);
-
 	sx_xunlock(&sc->sc_lock);
-
 	return (0);
 }
 

sys/dev/iscsi/iscsi_ioctl.h

@@ -67,7 +67,8 @@ struct iscsi_session_conf {
 	int		isc_data_digest;
 	int		isc_iser;
 	char		isc_offload[ISCSI_OFFLOAD_LEN];
-	int		isc_spare[2];
+	int		isc_enable;
+	int		isc_spare[1];
 };
 
 /*

usr.bin/iscsictl/iscsi.conf.5

@@ -125,6 +125,14 @@ must be defined.
 Discovery sessions result in the initiator connecting to all the targets
 returned by SendTargets iSCSI discovery with the defined
 .Sy TargetAddress .
+.It Cm Enable
+Enable or disable the session.
+State can be either
+.Qq Ar On ,
+or
+.Qq Ar Off .
+Default is
+.Qq Ar On .
 .It Cm Offload
 Name of selected iSCSI hardware offload driver.
 Default is

usr.bin/iscsictl/iscsictl.8

@@ -40,11 +40,13 @@
 .Op Fl u Ar user Fl s Ar secret
 .Op Fl w Ar timeout
 .Op Fl r
+.Op Fl e Cm on | off
 .Nm
 .Fl A
 .Fl d Ar discovery-host
 .Op Fl u Ar user Fl s Ar secret
 .Op Fl r
+.Op Fl e Cm on | off
 .Nm
 .Fl A
 .Fl a Op Fl c Ar path
@@ -58,6 +60,7 @@
 .Op Fl t Ar target
 .Op Fl u Ar user
 .Op Fl s Ar secret
+.Op Fl e Cm on | off
 .Nm
 .Fl M
 .Fl i Ar session-id
@@ -110,6 +113,10 @@ Target host name or address used for SendTargets discovery.
 When used, it will add a temporary discovery session.
 After discovery is done, sessions will be added for each discovered target,
 and the temporary discovery session will be removed.
+.It Fl e
+Enable or disable the session.
+This is ignored for discovery sessions, but gets passed down to normal
+sessions they add.
 .It Fl i
 Session ID, as displayed by
 .Nm
@@ -189,6 +196,12 @@ utility exits 0 on success, and >0 if an error occurs.
 Attach to target iqn.2012-06.com.example:target0, served by 192.168.1.1:
 .Dl Nm Fl A Fl t Ar iqn.2012-06.com.example:target0 Fl p Ar 192.168.1.1
 .Pp
+Perform discovery on 192.168.1.1, and add disabled sessions for each
+discovered target; use
+.Nm -M -e on
+to connect them:
+.Dl Nm Fl A Fl d Ar 192.168.1.1 Fl e Ar off
+.Pp
 Disconnect all iSCSI sessions:
 .Dl Nm Fl Ra
 .Sh SEE ALSO

usr.bin/iscsictl/iscsictl.c

@@ -98,7 +98,6 @@ target_delete(struct target *targ)
 	free(targ);
 }
 
-
 static char *
 default_initiator_name(void)
 {
@@ -152,6 +151,23 @@ valid_hex(const char ch)
 	}
 }
 
+int
+parse_enable(const char *enable)
+{
+	if (enable == NULL)
+		return (ENABLE_UNSPECIFIED);
+
+	if (strcasecmp(enable, "on") == 0 ||
+	    strcasecmp(enable, "yes") == 0)
+		return (ENABLE_ON);
+
+	if (strcasecmp(enable, "off") == 0 ||
+	    strcasecmp(enable, "no") == 0)
+		return (ENABLE_OFF);
+
+	return (ENABLE_UNSPECIFIED);
+}
+
 bool
 valid_iscsi_name(const char *name)
 {
@@ -325,6 +341,8 @@ conf_from_target(struct iscsi_session_conf *conf,
 		    sizeof(conf->isc_mutual_secret));
 	if (targ->t_session_type == SESSION_TYPE_DISCOVERY)
 		conf->isc_discovery = 1;
+	if (targ->t_enable != ENABLE_OFF)
+		conf->isc_enable = 1;
 	if (targ->t_protocol == PROTOCOL_ISER)
 		conf->isc_iser = 1;
 	if (targ->t_offload != NULL)
@@ -371,7 +389,7 @@ kernel_modify(int iscsi_fd, unsigned int session_id, const struct target *targ)
 
 static void
 kernel_modify_some(int iscsi_fd, unsigned int session_id, const char *target,
-  const char *target_addr, const char *user, const char *secret)
+  const char *target_addr, const char *user, const char *secret, int enable)
 {
 	struct iscsi_session_state *states = NULL;
 	struct iscsi_session_state *state;
@@ -421,6 +439,10 @@ kernel_modify_some(int iscsi_fd, unsigned int session_id, const char *target,
 		strlcpy(conf->isc_user, user, sizeof(conf->isc_user));
 	if (secret != NULL)
 		strlcpy(conf->isc_secret, secret, sizeof(conf->isc_secret));
+	if (enable == ENABLE_ON)
+		conf->isc_enable = 1;
+	else if (enable == ENABLE_OFF)
+		conf->isc_enable = 0;
 
 	memset(&ism, 0, sizeof(ism));
 	ism.ism_session_id = session_id;
@@ -527,6 +549,9 @@ kernel_list(int iscsi_fd, const struct target *targ __unused,
 			xo_emit("{L:/%-18s}{V:type/%s}\n",
 			    "Session type:",
 			    conf->isc_discovery ? "Discovery" : "Normal");
+			xo_emit("{L:/%-18s}{V:enable/%s}\n",
+			    "Enable:",
+			    conf->isc_enable ? "Yes" : "No");
 			xo_emit("{L:/%-18s}{V:state/%s}\n",
 			    "Session state:",
 			    state->iss_connected ? "Connected" : "Disconnected");
@@ -575,6 +600,8 @@ kernel_list(int iscsi_fd, const struct target *targ __unused,
 			} else {
 				if (conf->isc_discovery) {
 					xo_emit("{V:state}\n", "Discovery");
+				} else if (conf->isc_enable == 0) {
+					xo_emit("{V:state}\n", "Disabled");
 				} else if (state->iss_connected) {
 					xo_emit("{V:state}: ", "Connected");
 					print_periphs(state->iss_id);
@@ -653,13 +680,13 @@ usage(void)
 {
 
 	fprintf(stderr, "usage: iscsictl -A -p portal -t target "
-	    "[-u user -s secret] [-w timeout]\n");
+	    "[-u user -s secret] [-w timeout] [-e on | off]\n");
 	fprintf(stderr, "       iscsictl -A -d discovery-host "
-	    "[-u user -s secret]\n");
+	    "[-u user -s secret] [-e on | off]\n");
 	fprintf(stderr, "       iscsictl -A -a [-c path]\n");
 	fprintf(stderr, "       iscsictl -A -n nickname [-c path]\n");
 	fprintf(stderr, "       iscsictl -M -i session-id [-p portal] "
-	    "[-t target] [-u user] [-s secret]\n");
+	    "[-t target] [-u user] [-s secret] [-e on | off]\n");
 	fprintf(stderr, "       iscsictl -M -i session-id -n nickname "
 	    "[-c path]\n");
 	fprintf(stderr, "       iscsictl -R [-p portal] [-t target]\n");
@@ -687,8 +714,8 @@ main(int argc, char **argv)
 	    rflag = 0, vflag = 0;
 	const char *conf_path = DEFAULT_CONFIG_PATH;
 	char *nickname = NULL, *discovery_host = NULL, *portal = NULL,
-	     *target = NULL, *user = NULL, *secret = NULL;
+	    *target = NULL, *user = NULL, *secret = NULL;
-	int timeout = -1;
+	int timeout = -1, enable = ENABLE_UNSPECIFIED;
 	long long session_id = -1;
 	char *end;
 	int ch, error, iscsi_fd, retval, saved_errno;
@@ -699,7 +726,7 @@ main(int argc, char **argv)
 	argc = xo_parse_args(argc, argv);
 	xo_open_container("iscsictl");
 
-	while ((ch = getopt(argc, argv, "AMRLac:d:i:n:p:rt:u:s:vw:")) != -1) {
+	while ((ch = getopt(argc, argv, "AMRLac:d:e:i:n:p:rt:u:s:vw:")) != -1) {
 		switch (ch) {
 		case 'A':
 			Aflag = 1;
@@ -722,6 +749,13 @@ main(int argc, char **argv)
 		case 'd':
 			discovery_host = optarg;
 			break;
+		case 'e':
+			enable = parse_enable(optarg);
+			if (enable == ENABLE_UNSPECIFIED) {
+				xo_errx(1, "invalid argument to -e, "
+				    "must be either \"on\" or \"off\"");
+			}
+			break;
 		case 'i':
 			session_id = strtol(optarg, &end, 10);
 			if ((size_t)(end - optarg) != strlen(optarg))
@@ -781,6 +815,8 @@ main(int argc, char **argv)
 	 */
 	if (Aflag != 0) {
 		if (aflag != 0) {
+			if (enable != ENABLE_UNSPECIFIED)
+				xo_errx(1, "-a and -e and mutually exclusive");
 			if (portal != NULL)
 				xo_errx(1, "-a and -p and mutually exclusive");
 			if (target != NULL)
@@ -796,6 +832,8 @@ main(int argc, char **argv)
 			if (rflag != 0)
 				xo_errx(1, "-a and -r and mutually exclusive");
 		} else if (nickname != NULL) {
+			if (enable != ENABLE_UNSPECIFIED)
+				xo_errx(1, "-n and -e and mutually exclusive");
 			if (portal != NULL)
 				xo_errx(1, "-n and -p and mutually exclusive");
 			if (target != NULL)
@@ -838,6 +876,8 @@ main(int argc, char **argv)
 			xo_errx(1, "-M requires -i");
 
 		if (nickname != NULL) {
+			if (enable != ENABLE_UNSPECIFIED)
+				xo_errx(1, "-n and -e and mutually exclusive");
 			if (portal != NULL)
 				xo_errx(1, "-n and -p and mutually exclusive");
 			if (target != NULL)
@@ -878,6 +918,8 @@ main(int argc, char **argv)
 
 		if (discovery_host != NULL)
 			xo_errx(1, "-d cannot be used with -R");
+		if (enable != ENABLE_UNSPECIFIED)
+			xo_errx(1, "-e cannot be used with -R");
 		if (session_id != -1)
 			xo_errx(1, "-i cannot be used with -R");
 		if (rflag != 0)
@@ -946,7 +988,7 @@ main(int argc, char **argv)
 			failed += kernel_list(iscsi_fd, targ, vflag);
 	} else if (Mflag != 0) {
 		kernel_modify_some(iscsi_fd, session_id, target, portal,
-		    user, secret);
+		    user, secret, enable);
 	} else {
 		if (Aflag != 0 && target != NULL) {
 			if (valid_iscsi_name(target) == false)
@@ -965,6 +1007,7 @@ main(int argc, char **argv)
 			targ->t_session_type = SESSION_TYPE_NORMAL;
 			targ->t_address = portal;
 		}
+		targ->t_enable = enable;
 		if (rflag != 0)
 			targ->t_protocol = PROTOCOL_ISER;
 		targ->t_user = user;

usr.bin/iscsictl/iscsictl.h

@@ -58,6 +58,10 @@
 #define	PROTOCOL_ISCSI			1
 #define	PROTOCOL_ISER			2
 
+#define	ENABLE_UNSPECIFIED		0
+#define	ENABLE_ON			1
+#define	ENABLE_OFF			2
+
 struct target {
 	TAILQ_ENTRY(target)	t_next;
 	struct conf		*t_conf;
@@ -71,6 +75,7 @@ struct target {
 	int			t_data_digest;
 	int			t_auth_method;
 	int			t_session_type;
+	int			t_enable;
 	int			t_protocol;
 	char			*t_offload;
 	char			*t_user;
@@ -113,5 +118,6 @@ void		print_periphs(int session_id);
 
 char		*checked_strdup(const char *);
 bool		valid_iscsi_name(const char *name);
+int		parse_enable(const char *enable);
 
 #endif /* !ISCSICTL_H */

usr.bin/iscsictl/parse.y

@@ -56,7 +56,7 @@ extern void	yyrestart(FILE *);
 
 %}
 
-%token AUTH_METHOD HEADER_DIGEST DATA_DIGEST TARGET_NAME TARGET_ADDRESS
+%token AUTH_METHOD ENABLE HEADER_DIGEST DATA_DIGEST TARGET_NAME TARGET_ADDRESS
 %token INITIATOR_NAME INITIATOR_ADDRESS INITIATOR_ALIAS USER SECRET
 %token MUTUAL_USER MUTUAL_SECRET SEMICOLON SESSION_TYPE PROTOCOL OFFLOAD
 %token IGNORED EQUALS OPENING_BRACKET CLOSING_BRACKET
@@ -118,6 +118,8 @@ target_entry:
 	|
 	session_type
 	|
+	enable
+	|
 	offload
 	|
 	protocol
@@ -253,6 +255,17 @@ session_type:	SESSION_TYPE EQUALS STR
 	}
 	;
 
+enable:		ENABLE EQUALS STR
+	{
+		if (target->t_enable != ENABLE_UNSPECIFIED)
+			xo_errx(1, "duplicated enable at line %d", lineno);
+		target->t_enable = parse_enable($3);
+		if (target->t_enable == ENABLE_UNSPECIFIED)
+			xo_errx(1, "invalid enable at line %d; "
+			    "must be either \"on\" or \"off\"", lineno);
+	}
+	;
+
 offload:	OFFLOAD EQUALS STR
 	{
 		if (target->t_offload != NULL)

usr.bin/iscsictl/token.l

@@ -62,6 +62,7 @@ tgtChapName		{ return MUTUAL_USER; }
 tgtChapSecret		{ return MUTUAL_SECRET; }
 AuthMethod		{ return AUTH_METHOD; }
 SessionType		{ return SESSION_TYPE; }
+enable			{ return ENABLE; }
 protocol		{ return PROTOCOL; }
 offload			{ return OFFLOAD; }
 port			{ return IGNORED; }