scsi_transport_iscsi.c

linux 内核源代码

	rc = netlink_unicast(nls, skb, pid, MSG_DONTWAIT);
	if (rc < 0) {
		printk(KERN_ERR "iscsi: can not unicast skb (%d)\n", rc);
		return rc;
	}

	return 0;
}

int iscsi_recv_pdu(struct iscsi_cls_conn *conn, struct iscsi_hdr *hdr,
		   char *data, uint32_t data_size)
{
	struct nlmsghdr	*nlh;
	struct sk_buff *skb;
	struct iscsi_uevent *ev;
	char *pdu;
	struct iscsi_internal *priv;
	int len = NLMSG_SPACE(sizeof(*ev) + sizeof(struct iscsi_hdr) +
			      data_size);

	priv = iscsi_if_transport_lookup(conn->transport);
	if (!priv)
		return -EINVAL;

	skb = alloc_skb(len, GFP_ATOMIC);
	if (!skb) {
		iscsi_conn_error(conn, ISCSI_ERR_CONN_FAILED);
		dev_printk(KERN_ERR, &conn->dev, "iscsi: can not deliver "
			   "control PDU: OOM\n");
		return -ENOMEM;
	}

	nlh = __nlmsg_put(skb, priv->daemon_pid, 0, 0, (len - sizeof(*nlh)), 0);
	ev = NLMSG_DATA(nlh);
	memset(ev, 0, sizeof(*ev));
	ev->transport_handle = iscsi_handle(conn->transport);
	ev->type = ISCSI_KEVENT_RECV_PDU;
	ev->r.recv_req.cid = conn->cid;
	ev->r.recv_req.sid = iscsi_conn_get_sid(conn);
	pdu = (char*)ev + sizeof(*ev);
	memcpy(pdu, hdr, sizeof(struct iscsi_hdr));
	memcpy(pdu + sizeof(struct iscsi_hdr), data, data_size);

	return iscsi_unicast_skb(skb, priv->daemon_pid);
}
EXPORT_SYMBOL_GPL(iscsi_recv_pdu);

void iscsi_conn_error(struct iscsi_cls_conn *conn, enum iscsi_err error)
{
	struct nlmsghdr	*nlh;
	struct sk_buff	*skb;
	struct iscsi_uevent *ev;
	struct iscsi_internal *priv;
	int len = NLMSG_SPACE(sizeof(*ev));

	priv = iscsi_if_transport_lookup(conn->transport);
	if (!priv)
		return;

	skb = alloc_skb(len, GFP_ATOMIC);
	if (!skb) {
		dev_printk(KERN_ERR, &conn->dev, "iscsi: gracefully ignored "
			  "conn error (%d)\n", error);
		return;
	}

	nlh = __nlmsg_put(skb, priv->daemon_pid, 0, 0, (len - sizeof(*nlh)), 0);
	ev = NLMSG_DATA(nlh);
	ev->transport_handle = iscsi_handle(conn->transport);
	ev->type = ISCSI_KEVENT_CONN_ERROR;
	ev->r.connerror.error = error;
	ev->r.connerror.cid = conn->cid;
	ev->r.connerror.sid = iscsi_conn_get_sid(conn);

	iscsi_broadcast_skb(skb, GFP_ATOMIC);

	dev_printk(KERN_INFO, &conn->dev, "iscsi: detected conn error (%d)\n",
		   error);
}
EXPORT_SYMBOL_GPL(iscsi_conn_error);

static int
iscsi_if_send_reply(int pid, int seq, int type, int done, int multi,
		      void *payload, int size)
{
	struct sk_buff	*skb;
	struct nlmsghdr	*nlh;
	int len = NLMSG_SPACE(size);
	int flags = multi ? NLM_F_MULTI : 0;
	int t = done ? NLMSG_DONE : type;

	skb = alloc_skb(len, GFP_ATOMIC);
	if (!skb) {
		printk(KERN_ERR "Could not allocate skb to send reply.\n");
		return -ENOMEM;
	}

	nlh = __nlmsg_put(skb, pid, seq, t, (len - sizeof(*nlh)), 0);
	nlh->nlmsg_flags = flags;
	memcpy(NLMSG_DATA(nlh), payload, size);
	return iscsi_unicast_skb(skb, pid);
}

static int
iscsi_if_get_stats(struct iscsi_transport *transport, struct nlmsghdr *nlh)
{
	struct iscsi_uevent *ev = NLMSG_DATA(nlh);
	struct iscsi_stats *stats;
	struct sk_buff *skbstat;
	struct iscsi_cls_conn *conn;
	struct nlmsghdr	*nlhstat;
	struct iscsi_uevent *evstat;
	struct iscsi_internal *priv;
	int len = NLMSG_SPACE(sizeof(*ev) +
			      sizeof(struct iscsi_stats) +
			      sizeof(struct iscsi_stats_custom) *
			      ISCSI_STATS_CUSTOM_MAX);
	int err = 0;

	priv = iscsi_if_transport_lookup(transport);
	if (!priv)
		return -EINVAL;

	conn = iscsi_conn_lookup(ev->u.get_stats.sid, ev->u.get_stats.cid);
	if (!conn)
		return -EEXIST;

	do {
		int actual_size;

		skbstat = alloc_skb(len, GFP_ATOMIC);
		if (!skbstat) {
			dev_printk(KERN_ERR, &conn->dev, "iscsi: can not "
				   "deliver stats: OOM\n");
			return -ENOMEM;
		}

		nlhstat = __nlmsg_put(skbstat, priv->daemon_pid, 0, 0,
				      (len - sizeof(*nlhstat)), 0);
		evstat = NLMSG_DATA(nlhstat);
		memset(evstat, 0, sizeof(*evstat));
		evstat->transport_handle = iscsi_handle(conn->transport);
		evstat->type = nlh->nlmsg_type;
		evstat->u.get_stats.cid =
			ev->u.get_stats.cid;
		evstat->u.get_stats.sid =
			ev->u.get_stats.sid;
		stats = (struct iscsi_stats *)
			((char*)evstat + sizeof(*evstat));
		memset(stats, 0, sizeof(*stats));

		transport->get_stats(conn, stats);
		actual_size = NLMSG_SPACE(sizeof(struct iscsi_uevent) +
					  sizeof(struct iscsi_stats) +
					  sizeof(struct iscsi_stats_custom) *
					  stats->custom_length);
		actual_size -= sizeof(*nlhstat);
		actual_size = NLMSG_LENGTH(actual_size);
		skb_trim(skbstat, NLMSG_ALIGN(actual_size));
		nlhstat->nlmsg_len = actual_size;

		err = iscsi_unicast_skb(skbstat, priv->daemon_pid);
	} while (err < 0 && err != -ECONNREFUSED);

	return err;
}

/**
 * iscsi_if_destroy_session_done - send session destr. completion event
 * @conn: last connection for session
 *
 * This is called by HW iscsi LLDs to notify userpsace that its HW has
 * removed a session.
 **/
int iscsi_if_destroy_session_done(struct iscsi_cls_conn *conn)
{
	struct iscsi_internal *priv;
	struct iscsi_cls_session *session;
	struct Scsi_Host *shost;
	struct iscsi_uevent *ev;
	struct sk_buff  *skb;
	struct nlmsghdr *nlh;
	unsigned long flags;
	int rc, len = NLMSG_SPACE(sizeof(*ev));

	priv = iscsi_if_transport_lookup(conn->transport);
	if (!priv)
		return -EINVAL;

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

	skb = alloc_skb(len, GFP_KERNEL);
	if (!skb) {
		dev_printk(KERN_ERR, &conn->dev, "Cannot notify userspace of "
			  "session creation event\n");
		return -ENOMEM;
	}

	nlh = __nlmsg_put(skb, priv->daemon_pid, 0, 0, (len - sizeof(*nlh)), 0);
	ev = NLMSG_DATA(nlh);
	ev->transport_handle = iscsi_handle(conn->transport);
	ev->type = ISCSI_KEVENT_DESTROY_SESSION;
	ev->r.d_session.host_no = shost->host_no;
	ev->r.d_session.sid = session->sid;

	/*
	 * this will occur if the daemon is not up, so we just warn
	 * the user and when the daemon is restarted it will handle it
	 */
	rc = iscsi_broadcast_skb(skb, GFP_KERNEL);
	if (rc < 0)
		dev_printk(KERN_ERR, &conn->dev, "Cannot notify userspace of "
			  "session destruction event. Check iscsi daemon\n");

	spin_lock_irqsave(&sesslock, flags);
	list_del(&session->sess_list);
	spin_unlock_irqrestore(&sesslock, flags);

	spin_lock_irqsave(&connlock, flags);
	conn->active = 0;
	list_del(&conn->conn_list);
	spin_unlock_irqrestore(&connlock, flags);

	return rc;
}
EXPORT_SYMBOL_GPL(iscsi_if_destroy_session_done);

/**
 * iscsi_if_create_session_done - send session creation completion event
 * @conn: leading connection for session
 *
 * This is called by HW iscsi LLDs to notify userpsace that its HW has
 * created a session or a existing session is back in the logged in state.
 **/
int iscsi_if_create_session_done(struct iscsi_cls_conn *conn)
{
	struct iscsi_internal *priv;
	struct iscsi_cls_session *session;
	struct Scsi_Host *shost;
	struct iscsi_uevent *ev;
	struct sk_buff  *skb;
	struct nlmsghdr *nlh;
	unsigned long flags;
	int rc, len = NLMSG_SPACE(sizeof(*ev));

	priv = iscsi_if_transport_lookup(conn->transport);
	if (!priv)
		return -EINVAL;

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

	skb = alloc_skb(len, GFP_KERNEL);
	if (!skb) {
		dev_printk(KERN_ERR, &conn->dev, "Cannot notify userspace of "
			  "session creation event\n");
		return -ENOMEM;
	}

	nlh = __nlmsg_put(skb, priv->daemon_pid, 0, 0, (len - sizeof(*nlh)), 0);
	ev = NLMSG_DATA(nlh);
	ev->transport_handle = iscsi_handle(conn->transport);
	ev->type = ISCSI_UEVENT_CREATE_SESSION;
	ev->r.c_session_ret.host_no = shost->host_no;
	ev->r.c_session_ret.sid = session->sid;

	/*
	 * this will occur if the daemon is not up, so we just warn
	 * the user and when the daemon is restarted it will handle it
	 */
	rc = iscsi_broadcast_skb(skb, GFP_KERNEL);
	if (rc < 0)
		dev_printk(KERN_ERR, &conn->dev, "Cannot notify userspace of "
			  "session creation event. Check iscsi daemon\n");

	spin_lock_irqsave(&sesslock, flags);
	list_add(&session->sess_list, &sesslist);
	spin_unlock_irqrestore(&sesslock, flags);

	spin_lock_irqsave(&connlock, flags);
	list_add(&conn->conn_list, &connlist);
	conn->active = 1;
	spin_unlock_irqrestore(&connlock, flags);
	return rc;
}
EXPORT_SYMBOL_GPL(iscsi_if_create_session_done);

static int
iscsi_if_create_session(struct iscsi_internal *priv, struct iscsi_uevent *ev)
{
	struct iscsi_transport *transport = priv->iscsi_transport;
	struct iscsi_cls_session *session;
	unsigned long flags;
	uint32_t hostno;

	session = transport->create_session(transport, &priv->t,
					    ev->u.c_session.cmds_max,
					    ev->u.c_session.queue_depth,
					    ev->u.c_session.initial_cmdsn,
					    &hostno);
	if (!session)
		return -ENOMEM;

	spin_lock_irqsave(&sesslock, flags);
	list_add(&session->sess_list, &sesslist);
	spin_unlock_irqrestore(&sesslock, flags);

	ev->r.c_session_ret.host_no = hostno;
	ev->r.c_session_ret.sid = session->sid;
	return 0;
}

static int
iscsi_if_create_conn(struct iscsi_transport *transport, struct iscsi_uevent *ev)
{
	struct iscsi_cls_conn *conn;
	struct iscsi_cls_session *session;
	unsigned long flags;

	session = iscsi_session_lookup(ev->u.c_conn.sid);
	if (!session) {
		printk(KERN_ERR "iscsi: invalid session %d\n",
		       ev->u.c_conn.sid);
		return -EINVAL;
	}

	conn = transport->create_conn(session, ev->u.c_conn.cid);
	if (!conn) {
		printk(KERN_ERR "iscsi: couldn't create a new "
			   "connection for session %d\n",
			   session->sid);
		return -ENOMEM;
	}

	ev->r.c_conn_ret.sid = session->sid;
	ev->r.c_conn_ret.cid = conn->cid;

	spin_lock_irqsave(&connlock, flags);
	list_add(&conn->conn_list, &connlist);
	conn->active = 1;
	spin_unlock_irqrestore(&connlock, flags);

	return 0;
}

static int
iscsi_if_destroy_conn(struct iscsi_transport *transport, struct iscsi_uevent *ev)
{
	unsigned long flags;
	struct iscsi_cls_conn *conn;

	conn = iscsi_conn_lookup(ev->u.d_conn.sid, ev->u.d_conn.cid);
	if (!conn)
		return -EINVAL;
	spin_lock_irqsave(&connlock, flags);
	conn->active = 0;
	list_del(&conn->conn_list);
	spin_unlock_irqrestore(&connlock, flags);

	if (transport->destroy_conn)
		transport->destroy_conn(conn);
	return 0;
}

static int
iscsi_set_param(struct iscsi_transport *transport, struct iscsi_uevent *ev)
{
	char *data = (char*)ev + sizeof(*ev);
	struct iscsi_cls_conn *conn;
	struct iscsi_cls_session *session;
	int err = 0, value = 0;

	session = iscsi_session_lookup(ev->u.set_param.sid);
	conn = iscsi_conn_lookup(ev->u.set_param.sid, ev->u.set_param.cid);
	if (!conn || !session)
		return -EINVAL;

	switch (ev->u.set_param.param) {
	case ISCSI_PARAM_SESS_RECOVERY_TMO:
		sscanf(data, "%d", &value);
		if (value != 0)
			session->recovery_tmo = value;
		break;
	default:
		err = transport->set_param(conn, ev->u.set_param.param,
					   data, ev->u.set_param.len);
	}

	return err;
}

static int
iscsi_if_transport_ep(struct iscsi_transport *transport,
		      struct iscsi_uevent *ev, int msg_type)
{
	struct sockaddr *dst_addr;
	int rc = 0;

	switch (msg_type) {
	case ISCSI_UEVENT_TRANSPORT_EP_CONNECT:
		if (!transport->ep_connect)
			return -EINVAL;

		dst_addr = (struct sockaddr *)((char*)ev + sizeof(*ev));
		rc = transport->ep_connect(dst_addr,
					   ev->u.ep_connect.non_blocking,
					   &ev->r.ep_connect_ret.handle);
		break;
	case ISCSI_UEVENT_TRANSPORT_EP_POLL:
		if (!transport->ep_poll)
			return -EINVAL;

		ev->r.retcode = transport->ep_poll(ev->u.ep_poll.ep_handle,
						   ev->u.ep_poll.timeout_ms);
		break;
	case ISCSI_UEVENT_TRANSPORT_EP_DISCONNECT:
		if (!transport->ep_disconnect)
			return -EINVAL;

		transport->ep_disconnect(ev->u.ep_disconnect.ep_handle);
		break;
	}
	return rc;
}

static int
iscsi_tgt_dscvr(struct iscsi_transport *transport,
		struct iscsi_uevent *ev)
{
	struct Scsi_Host *shost;
	struct sockaddr *dst_addr;
	int err;

	if (!transport->tgt_dscvr)
		return -EINVAL;

	shost = scsi_host_lookup(ev->u.tgt_dscvr.host_no);
	if (IS_ERR(shost)) {
		printk(KERN_ERR "target discovery could not find host no %u\n",
		       ev->u.tgt_dscvr.host_no);
		return -ENODEV;
	}


	dst_addr = (struct sockaddr *)((char*)ev + sizeof(*ev));
	err = transport->tgt_dscvr(shost, ev->u.tgt_dscvr.type,
				   ev->u.tgt_dscvr.enable, dst_addr);
	scsi_host_put(shost);
	return err;
}

static int
iscsi_set_host_param(struct iscsi_transport *transport,
		     struct iscsi_uevent *ev)
{
	char *data = (char*)ev + sizeof(*ev);
	struct Scsi_Host *shost;
	int err;

	if (!transport->set_host_param)
		return -ENOSYS;

	shost = scsi_host_lookup(ev->u.set_host_param.host_no);
	if (IS_ERR(shost)) {
		printk(KERN_ERR "set_host_param could not find host no %u\n",
		       ev->u.set_host_param.host_no);
		return -ENODEV;
	}

	err = transport->set_host_param(shost, ev->u.set_host_param.param,
					data, ev->u.set_host_param.len);
	scsi_host_put(shost);
	return err;
}

static int
iscsi_if_recv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
{
	int err = 0;
	struct iscsi_uevent *ev = NLMSG_DATA(nlh);
	struct iscsi_transport *transport = NULL;
	struct iscsi_internal *priv;
	struct iscsi_cls_session *session;
	struct iscsi_cls_conn *conn;
	unsigned long flags;

	priv = iscsi_if_transport_lookup(iscsi_ptr(ev->transport_handle));
	if (!priv)
		return -EINVAL;
	transport = priv->iscsi_transport;

	if (!try_module_get(transport->owner))
		return -EINVAL;

	priv->daemon_pid = NETLINK_CREDS(skb)->pid;

	switch (nlh->nlmsg_type) {
	case ISCSI_UEVENT_CREATE_SESSION:
		err = iscsi_if_create_session(priv, ev);
		break;
	case ISCSI_UEVENT_DESTROY_SESSION:
		session = iscsi_session_lookup(ev->u.d_session.sid);
		if (session) {
			spin_lock_irqsave(&sesslock, flags);
			list_del(&session->sess_list);
			spin_unlock_irqrestore(&sesslock, flags);

			transport->destroy_session(session);
		} else
			err = -EINVAL;
		break;
	case ISCSI_UEVENT_CREATE_CONN:
		err = iscsi_if_create_conn(transport, ev);
		break;
	case ISCSI_UEVENT_DESTROY_CONN:
		err = iscsi_if_destroy_conn(transport, ev);