scsi_transport_iscsi.c

linux 内核源代码

		break;
	case ISCSI_UEVENT_BIND_CONN:
		session = iscsi_session_lookup(ev->u.b_conn.sid);
		conn = iscsi_conn_lookup(ev->u.b_conn.sid, ev->u.b_conn.cid);

		if (session && conn)
			ev->r.retcode =	transport->bind_conn(session, conn,
					ev->u.b_conn.transport_eph,
					ev->u.b_conn.is_leading);
		else
			err = -EINVAL;
		break;
	case ISCSI_UEVENT_SET_PARAM:
		err = iscsi_set_param(transport, ev);
		break;
	case ISCSI_UEVENT_START_CONN:
		conn = iscsi_conn_lookup(ev->u.start_conn.sid, ev->u.start_conn.cid);
		if (conn)
			ev->r.retcode = transport->start_conn(conn);
		else
			err = -EINVAL;
		break;
	case ISCSI_UEVENT_STOP_CONN:
		conn = iscsi_conn_lookup(ev->u.stop_conn.sid, ev->u.stop_conn.cid);
		if (conn)
			transport->stop_conn(conn, ev->u.stop_conn.flag);
		else
			err = -EINVAL;
		break;
	case ISCSI_UEVENT_SEND_PDU:
		conn = iscsi_conn_lookup(ev->u.send_pdu.sid, ev->u.send_pdu.cid);
		if (conn)
			ev->r.retcode =	transport->send_pdu(conn,
				(struct iscsi_hdr*)((char*)ev + sizeof(*ev)),
				(char*)ev + sizeof(*ev) + ev->u.send_pdu.hdr_size,
				ev->u.send_pdu.data_size);
		else
			err = -EINVAL;
		break;
	case ISCSI_UEVENT_GET_STATS:
		err = iscsi_if_get_stats(transport, nlh);
		break;
	case ISCSI_UEVENT_TRANSPORT_EP_CONNECT:
	case ISCSI_UEVENT_TRANSPORT_EP_POLL:
	case ISCSI_UEVENT_TRANSPORT_EP_DISCONNECT:
		err = iscsi_if_transport_ep(transport, ev, nlh->nlmsg_type);
		break;
	case ISCSI_UEVENT_TGT_DSCVR:
		err = iscsi_tgt_dscvr(transport, ev);
		break;
	case ISCSI_UEVENT_SET_HOST_PARAM:
		err = iscsi_set_host_param(transport, ev);
		break;
	default:
		err = -ENOSYS;
		break;
	}

	module_put(transport->owner);
	return err;
}

/*
 * Get message from skb.  Each message is processed by iscsi_if_recv_msg.
 * Malformed skbs with wrong lengths or invalid creds are not processed.
 */
static void
iscsi_if_rx(struct sk_buff *skb)
{
	mutex_lock(&rx_queue_mutex);
	while (skb->len >= NLMSG_SPACE(0)) {
		int err;
		uint32_t rlen;
		struct nlmsghdr	*nlh;
		struct iscsi_uevent *ev;

		nlh = nlmsg_hdr(skb);
		if (nlh->nlmsg_len < sizeof(*nlh) ||
		    skb->len < nlh->nlmsg_len) {
			break;
		}

		ev = NLMSG_DATA(nlh);
		rlen = NLMSG_ALIGN(nlh->nlmsg_len);
		if (rlen > skb->len)
			rlen = skb->len;

		err = iscsi_if_recv_msg(skb, nlh);
		if (err) {
			ev->type = ISCSI_KEVENT_IF_ERROR;
			ev->iferror = err;
		}
		do {
			/*
			 * special case for GET_STATS:
			 * on success - sending reply and stats from
			 * inside of if_recv_msg(),
			 * on error - fall through.
			 */
			if (ev->type == ISCSI_UEVENT_GET_STATS && !err)
				break;
			err = iscsi_if_send_reply(
				NETLINK_CREDS(skb)->pid, nlh->nlmsg_seq,
				nlh->nlmsg_type, 0, 0, ev, sizeof(*ev));
		} while (err < 0 && err != -ECONNREFUSED);
		skb_pull(skb, rlen);
	}
	mutex_unlock(&rx_queue_mutex);
}

#define iscsi_cdev_to_conn(_cdev) \
	iscsi_dev_to_conn(_cdev->dev)

#define ISCSI_CLASS_ATTR(_prefix,_name,_mode,_show,_store)		\
struct class_device_attribute class_device_attr_##_prefix##_##_name =	\
	__ATTR(_name,_mode,_show,_store)

/*
 * iSCSI connection attrs
 */
#define iscsi_conn_attr_show(param)					\
static ssize_t								\
show_conn_param_##param(struct class_device *cdev, char *buf)		\
{									\
	struct iscsi_cls_conn *conn = iscsi_cdev_to_conn(cdev);		\
	struct iscsi_transport *t = conn->transport;			\
	return t->get_conn_param(conn, param, buf);			\
}

#define iscsi_conn_attr(field, param)					\
	iscsi_conn_attr_show(param)					\
static ISCSI_CLASS_ATTR(conn, field, S_IRUGO, show_conn_param_##param,	\
			NULL);

iscsi_conn_attr(max_recv_dlength, ISCSI_PARAM_MAX_RECV_DLENGTH);
iscsi_conn_attr(max_xmit_dlength, ISCSI_PARAM_MAX_XMIT_DLENGTH);
iscsi_conn_attr(header_digest, ISCSI_PARAM_HDRDGST_EN);
iscsi_conn_attr(data_digest, ISCSI_PARAM_DATADGST_EN);
iscsi_conn_attr(ifmarker, ISCSI_PARAM_IFMARKER_EN);
iscsi_conn_attr(ofmarker, ISCSI_PARAM_OFMARKER_EN);
iscsi_conn_attr(persistent_port, ISCSI_PARAM_PERSISTENT_PORT);
iscsi_conn_attr(port, ISCSI_PARAM_CONN_PORT);
iscsi_conn_attr(exp_statsn, ISCSI_PARAM_EXP_STATSN);
iscsi_conn_attr(persistent_address, ISCSI_PARAM_PERSISTENT_ADDRESS);
iscsi_conn_attr(address, ISCSI_PARAM_CONN_ADDRESS);

#define iscsi_cdev_to_session(_cdev) \
	iscsi_dev_to_session(_cdev->dev)

/*
 * iSCSI session attrs
 */
#define iscsi_session_attr_show(param, perm)				\
static ssize_t								\
show_session_param_##param(struct class_device *cdev, char *buf)	\
{									\
	struct iscsi_cls_session *session = iscsi_cdev_to_session(cdev); \
	struct iscsi_transport *t = session->transport;			\
									\
	if (perm && !capable(CAP_SYS_ADMIN))				\
		return -EACCES;						\
	return t->get_session_param(session, param, buf);		\
}

#define iscsi_session_attr(field, param, perm)				\
	iscsi_session_attr_show(param, perm)				\
static ISCSI_CLASS_ATTR(sess, field, S_IRUGO, show_session_param_##param, \
			NULL);

iscsi_session_attr(targetname, ISCSI_PARAM_TARGET_NAME, 0);
iscsi_session_attr(initial_r2t, ISCSI_PARAM_INITIAL_R2T_EN, 0);
iscsi_session_attr(max_outstanding_r2t, ISCSI_PARAM_MAX_R2T, 0);
iscsi_session_attr(immediate_data, ISCSI_PARAM_IMM_DATA_EN, 0);
iscsi_session_attr(first_burst_len, ISCSI_PARAM_FIRST_BURST, 0);
iscsi_session_attr(max_burst_len, ISCSI_PARAM_MAX_BURST, 0);
iscsi_session_attr(data_pdu_in_order, ISCSI_PARAM_PDU_INORDER_EN, 0);
iscsi_session_attr(data_seq_in_order, ISCSI_PARAM_DATASEQ_INORDER_EN, 0);
iscsi_session_attr(erl, ISCSI_PARAM_ERL, 0);
iscsi_session_attr(tpgt, ISCSI_PARAM_TPGT, 0);
iscsi_session_attr(username, ISCSI_PARAM_USERNAME, 1);
iscsi_session_attr(username_in, ISCSI_PARAM_USERNAME_IN, 1);
iscsi_session_attr(password, ISCSI_PARAM_PASSWORD, 1);
iscsi_session_attr(password_in, ISCSI_PARAM_PASSWORD_IN, 1);

#define iscsi_priv_session_attr_show(field, format)			\
static ssize_t								\
show_priv_session_##field(struct class_device *cdev, char *buf)		\
{									\
	struct iscsi_cls_session *session = iscsi_cdev_to_session(cdev);\
	return sprintf(buf, format"\n", session->field);		\
}

#define iscsi_priv_session_attr(field, format)				\
	iscsi_priv_session_attr_show(field, format)			\
static ISCSI_CLASS_ATTR(priv_sess, field, S_IRUGO, show_priv_session_##field, \
			NULL)
iscsi_priv_session_attr(recovery_tmo, "%d");

/*
 * iSCSI host attrs
 */
#define iscsi_host_attr_show(param)					\
static ssize_t								\
show_host_param_##param(struct class_device *cdev, char *buf)		\
{									\
	struct Scsi_Host *shost = transport_class_to_shost(cdev);	\
	struct iscsi_internal *priv = to_iscsi_internal(shost->transportt); \
	return priv->iscsi_transport->get_host_param(shost, param, buf); \
}

#define iscsi_host_attr(field, param)					\
	iscsi_host_attr_show(param)					\
static ISCSI_CLASS_ATTR(host, field, S_IRUGO, show_host_param_##param,	\
			NULL);

iscsi_host_attr(netdev, ISCSI_HOST_PARAM_NETDEV_NAME);
iscsi_host_attr(hwaddress, ISCSI_HOST_PARAM_HWADDRESS);
iscsi_host_attr(ipaddress, ISCSI_HOST_PARAM_IPADDRESS);
iscsi_host_attr(initiatorname, ISCSI_HOST_PARAM_INITIATOR_NAME);

#define SETUP_PRIV_SESSION_RD_ATTR(field)				\
do {									\
	priv->session_attrs[count] = &class_device_attr_priv_sess_##field; \
	count++;							\
} while (0)


#define SETUP_SESSION_RD_ATTR(field, param_flag)			\
do {									\
	if (tt->param_mask & param_flag) {				\
		priv->session_attrs[count] = &class_device_attr_sess_##field; \
		count++;						\
	}								\
} while (0)

#define SETUP_CONN_RD_ATTR(field, param_flag)				\
do {									\
	if (tt->param_mask & param_flag) {				\
		priv->conn_attrs[count] = &class_device_attr_conn_##field; \
		count++;						\
	}								\
} while (0)

#define SETUP_HOST_RD_ATTR(field, param_flag)				\
do {									\
	if (tt->host_param_mask & param_flag) {				\
		priv->host_attrs[count] = &class_device_attr_host_##field; \
		count++;						\
	}								\
} while (0)

static int iscsi_session_match(struct attribute_container *cont,
			   struct device *dev)
{
	struct iscsi_cls_session *session;
	struct Scsi_Host *shost;
	struct iscsi_internal *priv;

	if (!iscsi_is_session_dev(dev))
		return 0;

	session = iscsi_dev_to_session(dev);
	shost = iscsi_session_to_shost(session);
	if (!shost->transportt)
		return 0;

	priv = to_iscsi_internal(shost->transportt);
	if (priv->session_cont.ac.class != &iscsi_session_class.class)
		return 0;

	return &priv->session_cont.ac == cont;
}

static int iscsi_conn_match(struct attribute_container *cont,
			   struct device *dev)
{
	struct iscsi_cls_session *session;
	struct iscsi_cls_conn *conn;
	struct Scsi_Host *shost;
	struct iscsi_internal *priv;

	if (!iscsi_is_conn_dev(dev))
		return 0;

	conn = iscsi_dev_to_conn(dev);
	session = iscsi_dev_to_session(conn->dev.parent);
	shost = iscsi_session_to_shost(session);

	if (!shost->transportt)
		return 0;

	priv = to_iscsi_internal(shost->transportt);
	if (priv->conn_cont.ac.class != &iscsi_connection_class.class)
		return 0;

	return &priv->conn_cont.ac == cont;
}

static int iscsi_host_match(struct attribute_container *cont,
			    struct device *dev)
{
	struct Scsi_Host *shost;
	struct iscsi_internal *priv;

	if (!scsi_is_host_device(dev))
		return 0;

	shost = dev_to_shost(dev);
	if (!shost->transportt  ||
	    shost->transportt->host_attrs.ac.class != &iscsi_host_class.class)
		return 0;

        priv = to_iscsi_internal(shost->transportt);
        return &priv->t.host_attrs.ac == cont;
}

struct scsi_transport_template *
iscsi_register_transport(struct iscsi_transport *tt)
{
	struct iscsi_internal *priv;
	unsigned long flags;
	int count = 0, err;

	BUG_ON(!tt);

	priv = iscsi_if_transport_lookup(tt);
	if (priv)
		return NULL;

	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
	if (!priv)
		return NULL;
	INIT_LIST_HEAD(&priv->list);
	priv->daemon_pid = -1;
	priv->iscsi_transport = tt;
	priv->t.user_scan = iscsi_user_scan;

	priv->cdev.class = &iscsi_transport_class;
	snprintf(priv->cdev.class_id, BUS_ID_SIZE, "%s", tt->name);
	err = class_device_register(&priv->cdev);
	if (err)
		goto free_priv;

	err = sysfs_create_group(&priv->cdev.kobj, &iscsi_transport_group);
	if (err)
		goto unregister_cdev;

	/* host parameters */
	priv->t.host_attrs.ac.attrs = &priv->host_attrs[0];
	priv->t.host_attrs.ac.class = &iscsi_host_class.class;
	priv->t.host_attrs.ac.match = iscsi_host_match;
	priv->t.host_size = sizeof(struct iscsi_host);
	transport_container_register(&priv->t.host_attrs);

	SETUP_HOST_RD_ATTR(netdev, ISCSI_HOST_NETDEV_NAME);
	SETUP_HOST_RD_ATTR(ipaddress, ISCSI_HOST_IPADDRESS);
	SETUP_HOST_RD_ATTR(hwaddress, ISCSI_HOST_HWADDRESS);
	SETUP_HOST_RD_ATTR(initiatorname, ISCSI_HOST_INITIATOR_NAME);
	BUG_ON(count > ISCSI_HOST_ATTRS);
	priv->host_attrs[count] = NULL;
	count = 0;

	/* connection parameters */
	priv->conn_cont.ac.attrs = &priv->conn_attrs[0];
	priv->conn_cont.ac.class = &iscsi_connection_class.class;
	priv->conn_cont.ac.match = iscsi_conn_match;
	transport_container_register(&priv->conn_cont);

	SETUP_CONN_RD_ATTR(max_recv_dlength, ISCSI_MAX_RECV_DLENGTH);
	SETUP_CONN_RD_ATTR(max_xmit_dlength, ISCSI_MAX_XMIT_DLENGTH);
	SETUP_CONN_RD_ATTR(header_digest, ISCSI_HDRDGST_EN);
	SETUP_CONN_RD_ATTR(data_digest, ISCSI_DATADGST_EN);
	SETUP_CONN_RD_ATTR(ifmarker, ISCSI_IFMARKER_EN);
	SETUP_CONN_RD_ATTR(ofmarker, ISCSI_OFMARKER_EN);
	SETUP_CONN_RD_ATTR(address, ISCSI_CONN_ADDRESS);
	SETUP_CONN_RD_ATTR(port, ISCSI_CONN_PORT);
	SETUP_CONN_RD_ATTR(exp_statsn, ISCSI_EXP_STATSN);
	SETUP_CONN_RD_ATTR(persistent_address, ISCSI_PERSISTENT_ADDRESS);
	SETUP_CONN_RD_ATTR(persistent_port, ISCSI_PERSISTENT_PORT);

	BUG_ON(count > ISCSI_CONN_ATTRS);
	priv->conn_attrs[count] = NULL;
	count = 0;

	/* session parameters */
	priv->session_cont.ac.attrs = &priv->session_attrs[0];
	priv->session_cont.ac.class = &iscsi_session_class.class;
	priv->session_cont.ac.match = iscsi_session_match;
	transport_container_register(&priv->session_cont);

	SETUP_SESSION_RD_ATTR(initial_r2t, ISCSI_INITIAL_R2T_EN);
	SETUP_SESSION_RD_ATTR(max_outstanding_r2t, ISCSI_MAX_R2T);
	SETUP_SESSION_RD_ATTR(immediate_data, ISCSI_IMM_DATA_EN);
	SETUP_SESSION_RD_ATTR(first_burst_len, ISCSI_FIRST_BURST);
	SETUP_SESSION_RD_ATTR(max_burst_len, ISCSI_MAX_BURST);
	SETUP_SESSION_RD_ATTR(data_pdu_in_order, ISCSI_PDU_INORDER_EN);
	SETUP_SESSION_RD_ATTR(data_seq_in_order, ISCSI_DATASEQ_INORDER_EN);
	SETUP_SESSION_RD_ATTR(erl, ISCSI_ERL);
	SETUP_SESSION_RD_ATTR(targetname, ISCSI_TARGET_NAME);
	SETUP_SESSION_RD_ATTR(tpgt, ISCSI_TPGT);
	SETUP_SESSION_RD_ATTR(password, ISCSI_USERNAME);
	SETUP_SESSION_RD_ATTR(password_in, ISCSI_USERNAME_IN);
	SETUP_SESSION_RD_ATTR(username, ISCSI_PASSWORD);
	SETUP_SESSION_RD_ATTR(username_in, ISCSI_PASSWORD_IN);
	SETUP_PRIV_SESSION_RD_ATTR(recovery_tmo);

	BUG_ON(count > ISCSI_SESSION_ATTRS);
	priv->session_attrs[count] = NULL;

	spin_lock_irqsave(&iscsi_transport_lock, flags);
	list_add(&priv->list, &iscsi_transports);
	spin_unlock_irqrestore(&iscsi_transport_lock, flags);

	printk(KERN_NOTICE "iscsi: registered transport (%s)\n", tt->name);
	return &priv->t;

unregister_cdev:
	class_device_unregister(&priv->cdev);
free_priv:
	kfree(priv);
	return NULL;
}
EXPORT_SYMBOL_GPL(iscsi_register_transport);

int iscsi_unregister_transport(struct iscsi_transport *tt)
{
	struct iscsi_internal *priv;
	unsigned long flags;

	BUG_ON(!tt);

	mutex_lock(&rx_queue_mutex);

	priv = iscsi_if_transport_lookup(tt);
	BUG_ON (!priv);

	spin_lock_irqsave(&iscsi_transport_lock, flags);
	list_del(&priv->list);
	spin_unlock_irqrestore(&iscsi_transport_lock, flags);

	transport_container_unregister(&priv->conn_cont);
	transport_container_unregister(&priv->session_cont);
	transport_container_unregister(&priv->t.host_attrs);

	sysfs_remove_group(&priv->cdev.kobj, &iscsi_transport_group);
	class_device_unregister(&priv->cdev);
	mutex_unlock(&rx_queue_mutex);

	return 0;
}
EXPORT_SYMBOL_GPL(iscsi_unregister_transport);

static __init int iscsi_transport_init(void)
{
	int err;

	printk(KERN_INFO "Loading iSCSI transport class v%s.\n",
		ISCSI_TRANSPORT_VERSION);

	atomic_set(&iscsi_session_nr, 0);

	err = class_register(&iscsi_transport_class);
	if (err)
		return err;

	err = transport_class_register(&iscsi_host_class);
	if (err)
		goto unregister_transport_class;

	err = transport_class_register(&iscsi_connection_class);
	if (err)
		goto unregister_host_class;

	err = transport_class_register(&iscsi_session_class);
	if (err)
		goto unregister_conn_class;

	nls = netlink_kernel_create(&init_net, NETLINK_ISCSI, 1, iscsi_if_rx, NULL,
			THIS_MODULE);
	if (!nls) {
		err = -ENOBUFS;
		goto unregister_session_class;
	}

	return 0;

unregister_session_class:
	transport_class_unregister(&iscsi_session_class);
unregister_conn_class:
	transport_class_unregister(&iscsi_connection_class);
unregister_host_class:
	transport_class_unregister(&iscsi_host_class);
unregister_transport_class:
	class_unregister(&iscsi_transport_class);
	return err;
}

static void __exit iscsi_transport_exit(void)
{
	sock_release(nls->sk_socket);
	transport_class_unregister(&iscsi_connection_class);
	transport_class_unregister(&iscsi_session_class);
	transport_class_unregister(&iscsi_host_class);
	class_unregister(&iscsi_transport_class);
}

module_init(iscsi_transport_init);
module_exit(iscsi_transport_exit);

MODULE_AUTHOR("Mike Christie <[e-mail]>, "
	      "Dmitry Yusupov <[e-mail]>, "
	      "Alex Aizman <[e-mail]>");
MODULE_DESCRIPTION("iSCSI Transport Interface");
MODULE_LICENSE("GPL");
MODULE_VERSION(ISCSI_TRANSPORT_VERSION);