Make iSCSI initiator keep Initiator Session ID (ISID) across reconnects.

Previously ISID was changed every time, that made impossible correct
persistent reservation, because reconnected session was identified as
completely new one.

Reviewed by:	trasz
MFC after:	1 week

sys/dev/iscsi/iscsi.c

@@ -1221,6 +1221,9 @@ iscsi_ioctl_daemon_wait(struct iscsi_softc *sc,
 		ISCSI_SESSION_UNLOCK(is);
 
 		request->idr_session_id = is->is_id;
+		memcpy(&request->idr_isid, &is->is_isid,
+		    sizeof(request->idr_isid));
+		request->idr_tsih = 0;	/* New or reinstated session. */
 		memcpy(&request->idr_conf, &is->is_conf,
 		    sizeof(request->idr_conf));
 
@@ -1270,7 +1273,7 @@ iscsi_ioctl_daemon_handoff(struct iscsi_softc *sc,
 
 	strlcpy(is->is_target_alias, handoff->idh_target_alias,
 	    sizeof(is->is_target_alias));
-	memcpy(is->is_isid, handoff->idh_isid, sizeof(is->is_isid));
+	is->is_tsih = handoff->idh_tsih;
 	is->is_statsn = handoff->idh_statsn;
 	is->is_initial_r2t = handoff->idh_initial_r2t;
 	is->is_immediate_data = handoff->idh_immediate_data;
@@ -1663,6 +1666,9 @@ iscsi_ioctl_session_add(struct iscsi_softc *sc, struct iscsi_session_add *isa)
 	is->is_softc = sc;
 	sc->sc_last_session_id++;
 	is->is_id = sc->sc_last_session_id;
+	is->is_isid[0] = 0x80; /* RFC 3720, 10.12.5: 10b, "Random" ISID. */
+	arc4rand(&is->is_isid[1], 5, 0);
+	is->is_tsih = 0;
 	callout_init(&is->is_callout, 1);
 	callout_reset(&is->is_callout, 1 * hz, iscsi_callout, is);
 	TAILQ_INSERT_TAIL(&sc->sc_sessions, is, is_next);

sys/dev/iscsi/iscsi.h

@@ -64,6 +64,7 @@ struct iscsi_session {
 	size_t				is_max_burst_length;
 	size_t				is_first_burst_length;
 	uint8_t				is_isid[6];
+	uint16_t			is_tsih;
 	bool				is_immediate_data;
 	size_t				is_max_data_segment_length;
 	char				is_target_alias[ISCSI_ALIAS_LEN];

sys/dev/iscsi/iscsi_ioctl.h

@@ -91,8 +91,8 @@ struct iscsi_session_state {
 struct iscsi_daemon_request {
 	unsigned int			idr_session_id;
 	struct iscsi_session_conf	idr_conf;
-	uint8_t				idr_spare_isid[6];
-	uint16_t			idr_spare_tsih;
+	uint8_t				idr_isid[6];
+	uint16_t			idr_tsih;
 	uint16_t			idr_spare_cid;
 	int				idr_spare[4];
 };
@@ -101,9 +101,9 @@ struct iscsi_daemon_handoff {
 	unsigned int			idh_session_id;
 	int				idh_socket;
 	char				idh_target_alias[ISCSI_ALIAS_LEN];
-	uint8_t				idh_isid[6];
-	uint16_t			idr_spare_tsih;
-	uint16_t			idr_spare_cid;
+	uint8_t				idh_spare_isid[6];
+	uint16_t			idh_tsih;
+	uint16_t			idh_spare_cid;
 	uint32_t			idh_statsn;
 	int				idh_header_digest;
 	int				idh_data_digest;

usr.sbin/iscsid/iscsid.c

@@ -149,8 +149,8 @@ resolve_addr(const struct connection *conn, const char *address,
 }
 
 static struct connection *
-connection_new(unsigned int session_id, const struct iscsi_session_conf *conf,
-    int iscsi_fd)
+connection_new(unsigned int session_id, const uint8_t isid[8], uint16_t tsih,
+    const struct iscsi_session_conf *conf, int iscsi_fd)
 {
 	struct connection *conn;
 	struct addrinfo *from_ai, *to_ai;
@@ -176,6 +176,8 @@ connection_new(unsigned int session_id, const struct iscsi_session_conf *conf,
 	conn->conn_first_burst_length = 65536;
 
 	conn->conn_session_id = session_id;
+	memcpy(&conn->conn_isid, isid, sizeof(conn->conn_isid));
+	conn->conn_tsih = tsih;
 	conn->conn_iscsi_fd = iscsi_fd;
 
 	/*
@@ -264,7 +266,7 @@ handoff(struct connection *conn)
 	idh.idh_socket = conn->conn_socket;
 	strlcpy(idh.idh_target_alias, conn->conn_target_alias,
 	    sizeof(idh.idh_target_alias));
-	memcpy(idh.idh_isid, conn->conn_isid, sizeof(idh.idh_isid));
+	idh.idh_tsih = conn->conn_tsih;
 	idh.idh_statsn = conn->conn_statsn;
 	idh.idh_header_digest = conn->conn_header_digest;
 	idh.idh_data_digest = conn->conn_data_digest;
@@ -430,7 +432,8 @@ handle_request(int iscsi_fd, const struct iscsi_daemon_request *request, int tim
 		setproctitle("%s", request->idr_conf.isc_target_addr);
 	}
 
-	conn = connection_new(request->idr_session_id, &request->idr_conf, iscsi_fd);
+	conn = connection_new(request->idr_session_id, request->idr_isid,
+	    request->idr_tsih, &request->idr_conf, iscsi_fd);
 	set_timeout(timeout);
 	capsicate(conn);
 	login(conn);

usr.sbin/iscsid/iscsid.h

@@ -51,6 +51,7 @@ struct connection {
 	struct iscsi_session_conf	conn_conf;
 	char			conn_target_alias[ISCSI_ADDR_LEN];
 	uint8_t			conn_isid[6];
+	uint16_t		conn_tsih;
 	uint32_t		conn_statsn;
 	int			conn_header_digest;
 	int			conn_data_digest;

usr.sbin/iscsid/login.c

@@ -260,6 +260,7 @@ login_receive(struct connection *conn)
 		    "is %d, should be %d", ntohl(bhslr->bhslr_statsn),
 		    conn->conn_statsn + 1);
 	}
+	conn->conn_tsih = ntohs(bhslr->bhslr_tsih);
 	conn->conn_statsn = ntohl(bhslr->bhslr_statsn);
 
 	initial = false;
@@ -295,6 +296,7 @@ login_new_request(struct connection *conn, int csg)
 	login_set_nsg(request, nsg);
 
 	memcpy(bhslr->bhslr_isid, &conn->conn_isid, sizeof(bhslr->bhslr_isid));
+	bhslr->bhslr_tsih = htons(conn->conn_tsih);
 	bhslr->bhslr_initiator_task_tag = 0;
 	bhslr->bhslr_cmdsn = 0;
 	bhslr->bhslr_expstatsn = htonl(conn->conn_statsn + 1);
@@ -824,24 +826,6 @@ login_chap(struct connection *conn)
 	log_debugx("CHAP authentication done");
 }
 
-static void
-login_create_isid(struct connection *conn)
-{
-	int rv;
-
-	/*
-	 * RFC 3720, 10.12.5: 10b, "Random" ISID.
-	 *
-	 */
-	conn->conn_isid[0] = 0x80; 
-
-	rv = RAND_bytes(&conn->conn_isid[1], 3);
-	if (rv != 1) {
-		log_errx(1, "RAND_bytes failed: %s",
-		    ERR_error_string(ERR_get_error(), NULL));
-	}
-}
-
 void
 login(struct connection *conn)
 {
@@ -851,8 +835,6 @@ login(struct connection *conn)
 	const char *auth_method;
 	int i;
 
-	login_create_isid(conn);
-
 	log_debugx("beginning Login phase; sending Login PDU");
 	request = login_new_request(conn, BHSLR_STAGE_SECURITY_NEGOTIATION);
 	request_keys = keys_new();