netiucv.c

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 * @param arg   Generic pointer, casted from struct net_device * upon call.
 */
static void
dev_action_conndown(fsm_instance *fi, int event, void *arg)
{
	IUCV_DBF_TEXT(trace, 3, __FUNCTION__);

	switch (fsm_getstate(fi)) {
		case DEV_STATE_RUNNING:
			fsm_newstate(fi, DEV_STATE_STARTWAIT);
			break;
		case DEV_STATE_STOPWAIT:
			fsm_newstate(fi, DEV_STATE_STOPPED);
			IUCV_DBF_TEXT(setup, 3, "connection is down\n");
			break;
	}
}

static const fsm_node dev_fsm[] = {
	{ DEV_STATE_STOPPED,    DEV_EVENT_START,   dev_action_start    },

	{ DEV_STATE_STOPWAIT,   DEV_EVENT_START,   dev_action_start    },
	{ DEV_STATE_STOPWAIT,   DEV_EVENT_CONDOWN, dev_action_conndown },

	{ DEV_STATE_STARTWAIT,  DEV_EVENT_STOP,    dev_action_stop     },
	{ DEV_STATE_STARTWAIT,  DEV_EVENT_CONUP,   dev_action_connup   },

	{ DEV_STATE_RUNNING,    DEV_EVENT_STOP,    dev_action_stop     },
	{ DEV_STATE_RUNNING,    DEV_EVENT_CONDOWN, dev_action_conndown },
	{ DEV_STATE_RUNNING,    DEV_EVENT_CONUP,   fsm_action_nop      },
};

static const int DEV_FSM_LEN = sizeof(dev_fsm) / sizeof(fsm_node);

/**
 * Transmit a packet.
 * This is a helper function for netiucv_tx().
 *
 * @param conn Connection to be used for sending.
 * @param skb Pointer to struct sk_buff of packet to send.
 *            The linklevel header has already been set up
 *            by netiucv_tx().
 *
 * @return 0 on success, -ERRNO on failure. (Never fails.)
 */
static int netiucv_transmit_skb(struct iucv_connection *conn,
				struct sk_buff *skb)
{
	struct iucv_message msg;
	unsigned long saveflags;
	struct ll_header header;
	int rc;

	if (fsm_getstate(conn->fsm) != CONN_STATE_IDLE) {
		int l = skb->len + NETIUCV_HDRLEN;

		spin_lock_irqsave(&conn->collect_lock, saveflags);
		if (conn->collect_len + l >
		    (conn->max_buffsize - NETIUCV_HDRLEN)) {
			rc = -EBUSY;
			IUCV_DBF_TEXT(data, 2,
				      "EBUSY from netiucv_transmit_skb\n");
		} else {
			atomic_inc(&skb->users);
			skb_queue_tail(&conn->collect_queue, skb);
			conn->collect_len += l;
			rc = 0;
		}
		spin_unlock_irqrestore(&conn->collect_lock, saveflags);
	} else {
		struct sk_buff *nskb = skb;
		/**
		 * Copy the skb to a new allocated skb in lowmem only if the
		 * data is located above 2G in memory or tailroom is < 2.
		 */
		unsigned long hi = ((unsigned long)(skb_tail_pointer(skb) +
				    NETIUCV_HDRLEN)) >> 31;
		int copied = 0;
		if (hi || (skb_tailroom(skb) < 2)) {
			nskb = alloc_skb(skb->len + NETIUCV_HDRLEN +
					 NETIUCV_HDRLEN, GFP_ATOMIC | GFP_DMA);
			if (!nskb) {
				PRINT_WARN("%s: Could not allocate tx_skb\n",
				       conn->netdev->name);
				IUCV_DBF_TEXT(data, 2, "alloc_skb failed\n");
				rc = -ENOMEM;
				return rc;
			} else {
				skb_reserve(nskb, NETIUCV_HDRLEN);
				memcpy(skb_put(nskb, skb->len),
				       skb->data, skb->len);
			}
			copied = 1;
		}
		/**
		 * skb now is below 2G and has enough room. Add headers.
		 */
		header.next = nskb->len + NETIUCV_HDRLEN;
		memcpy(skb_push(nskb, NETIUCV_HDRLEN), &header, NETIUCV_HDRLEN);
		header.next = 0;
		memcpy(skb_put(nskb, NETIUCV_HDRLEN), &header,  NETIUCV_HDRLEN);

		fsm_newstate(conn->fsm, CONN_STATE_TX);
		conn->prof.send_stamp = current_kernel_time();

		msg.tag = 1;
		msg.class = 0;
		rc = iucv_message_send(conn->path, &msg, 0, 0,
				       nskb->data, nskb->len);
		conn->prof.doios_single++;
		conn->prof.txlen += skb->len;
		conn->prof.tx_pending++;
		if (conn->prof.tx_pending > conn->prof.tx_max_pending)
			conn->prof.tx_max_pending = conn->prof.tx_pending;
		if (rc) {
			struct netiucv_priv *privptr;
			fsm_newstate(conn->fsm, CONN_STATE_IDLE);
			conn->prof.tx_pending--;
			privptr = netdev_priv(conn->netdev);
			if (privptr)
				privptr->stats.tx_errors++;
			if (copied)
				dev_kfree_skb(nskb);
			else {
				/**
				 * Remove our headers. They get added
				 * again on retransmit.
				 */
				skb_pull(skb, NETIUCV_HDRLEN);
				skb_trim(skb, skb->len - NETIUCV_HDRLEN);
			}
			PRINT_WARN("iucv_send returned %08x\n",	rc);
			IUCV_DBF_TEXT_(data, 2, "rc %d from iucv_send\n", rc);
		} else {
			if (copied)
				dev_kfree_skb(skb);
			atomic_inc(&nskb->users);
			skb_queue_tail(&conn->commit_queue, nskb);
		}
	}

	return rc;
}

/*
 * Interface API for upper network layers
 */

/**
 * Open an interface.
 * Called from generic network layer when ifconfig up is run.
 *
 * @param dev Pointer to interface struct.
 *
 * @return 0 on success, -ERRNO on failure. (Never fails.)
 */
static int netiucv_open(struct net_device *dev)
{
	struct netiucv_priv *priv = netdev_priv(dev);

	fsm_event(priv->fsm, DEV_EVENT_START, dev);
	return 0;
}

/**
 * Close an interface.
 * Called from generic network layer when ifconfig down is run.
 *
 * @param dev Pointer to interface struct.
 *
 * @return 0 on success, -ERRNO on failure. (Never fails.)
 */
static int netiucv_close(struct net_device *dev)
{
	struct netiucv_priv *priv = netdev_priv(dev);

	fsm_event(priv->fsm, DEV_EVENT_STOP, dev);
	return 0;
}

/**
 * Start transmission of a packet.
 * Called from generic network device layer.
 *
 * @param skb Pointer to buffer containing the packet.
 * @param dev Pointer to interface struct.
 *
 * @return 0 if packet consumed, !0 if packet rejected.
 *         Note: If we return !0, then the packet is free'd by
 *               the generic network layer.
 */
static int netiucv_tx(struct sk_buff *skb, struct net_device *dev)
{
	struct netiucv_priv *privptr = netdev_priv(dev);
	int rc;

	IUCV_DBF_TEXT(trace, 4, __FUNCTION__);
	/**
	 * Some sanity checks ...
	 */
	if (skb == NULL) {
		PRINT_WARN("%s: NULL sk_buff passed\n", dev->name);
		IUCV_DBF_TEXT(data, 2, "netiucv_tx: skb is NULL\n");
		privptr->stats.tx_dropped++;
		return 0;
	}
	if (skb_headroom(skb) < NETIUCV_HDRLEN) {
		PRINT_WARN("%s: Got sk_buff with head room < %ld bytes\n",
		       dev->name, NETIUCV_HDRLEN);
		IUCV_DBF_TEXT(data, 2,
			"netiucv_tx: skb_headroom < NETIUCV_HDRLEN\n");
		dev_kfree_skb(skb);
		privptr->stats.tx_dropped++;
		return 0;
	}

	/**
	 * If connection is not running, try to restart it
	 * and throw away packet.
	 */
	if (fsm_getstate(privptr->fsm) != DEV_STATE_RUNNING) {
		if (!in_atomic())
			fsm_event(privptr->fsm, DEV_EVENT_START, dev);
		dev_kfree_skb(skb);
		privptr->stats.tx_dropped++;
		privptr->stats.tx_errors++;
		privptr->stats.tx_carrier_errors++;
		return 0;
	}

	if (netiucv_test_and_set_busy(dev)) {
		IUCV_DBF_TEXT(data, 2, "EBUSY from netiucv_tx\n");
		return -EBUSY;
	}
	dev->trans_start = jiffies;
	rc = netiucv_transmit_skb(privptr->conn, skb) != 0;
	netiucv_clear_busy(dev);
	return rc;
}

/**
 * netiucv_stats
 * @dev: Pointer to interface struct.
 *
 * Returns interface statistics of a device.
 *
 * Returns pointer to stats struct of this interface.
 */
static struct net_device_stats *netiucv_stats (struct net_device * dev)
{
	struct netiucv_priv *priv = netdev_priv(dev);

	IUCV_DBF_TEXT(trace, 5, __FUNCTION__);
	return &priv->stats;
}

/**
 * netiucv_change_mtu
 * @dev: Pointer to interface struct.
 * @new_mtu: The new MTU to use for this interface.
 *
 * Sets MTU of an interface.
 *
 * Returns 0 on success, -EINVAL if MTU is out of valid range.
 *         (valid range is 576 .. NETIUCV_MTU_MAX).
 */
static int netiucv_change_mtu(struct net_device * dev, int new_mtu)
{
	IUCV_DBF_TEXT(trace, 3, __FUNCTION__);
	if (new_mtu < 576 || new_mtu > NETIUCV_MTU_MAX) {
		IUCV_DBF_TEXT(setup, 2, "given MTU out of valid range\n");
		return -EINVAL;
	}
	dev->mtu = new_mtu;
	return 0;
}

/*
 * attributes in sysfs
 */

static ssize_t user_show(struct device *dev, struct device_attribute *attr,
			 char *buf)
{
	struct netiucv_priv *priv = dev->driver_data;

	IUCV_DBF_TEXT(trace, 5, __FUNCTION__);
	return sprintf(buf, "%s\n", netiucv_printname(priv->conn->userid));
}

static ssize_t user_write(struct device *dev, struct device_attribute *attr,
			  const char *buf, size_t count)
{
	struct netiucv_priv *priv = dev->driver_data;
	struct net_device *ndev = priv->conn->netdev;
	char    *p;
	char    *tmp;
	char 	username[9];
	int 	i;
	struct iucv_connection *cp;

	IUCV_DBF_TEXT(trace, 3, __FUNCTION__);
	if (count > 9) {
		PRINT_WARN("netiucv: username too long (%d)!\n", (int) count);
		IUCV_DBF_TEXT_(setup, 2,
			       "%d is length of username\n", (int) count);
		return -EINVAL;
	}

	tmp = strsep((char **) &buf, "\n");
	for (i = 0, p = tmp; i < 8 && *p; i++, p++) {
		if (isalnum(*p) || (*p == '$')) {
			username[i]= toupper(*p);
			continue;
		}
		if (*p == '\n') {
			/* trailing lf, grr */
			break;
		}
		PRINT_WARN("netiucv: Invalid char %c in username!\n", *p);
		IUCV_DBF_TEXT_(setup, 2,
			       "username: invalid character %c\n", *p);
		return -EINVAL;
	}
	while (i < 8)
		username[i++] = ' ';
	username[8] = '\0';

	if (memcmp(username, priv->conn->userid, 9) &&
	    (ndev->flags & (IFF_UP | IFF_RUNNING))) {
		/* username changed while the interface is active. */
		PRINT_WARN("netiucv: device %s active, connected to %s\n",
			   dev->bus_id, priv->conn->userid);
		PRINT_WARN("netiucv: user cannot be updated\n");
		IUCV_DBF_TEXT(setup, 2, "user_write: device active\n");
		return -EBUSY;
	}
	read_lock_bh(&iucv_connection_rwlock);
	list_for_each_entry(cp, &iucv_connection_list, list) {
		if (!strncmp(username, cp->userid, 9) && cp->netdev != ndev) {
			read_unlock_bh(&iucv_connection_rwlock);
			PRINT_WARN("netiucv: Connection to %s already "
				   "exists\n", username);
			return -EEXIST;
		}
	}
	read_unlock_bh(&iucv_connection_rwlock);
	memcpy(priv->conn->userid, username, 9);
	return count;
}

static DEVICE_ATTR(user, 0644, user_show, user_write);

static ssize_t buffer_show (struct device *dev, struct device_attribute *attr,
			    char *buf)
{	struct netiucv_priv *priv = dev->driver_data;

	IUCV_DBF_TEXT(trace, 5, __FUNCTION__);
	return sprintf(buf, "%d\n", priv->conn->max_buffsize);
}

static ssize_t buffer_write (struct device *dev, struct device_attribute *attr,
			     const char *buf, size_t count)
{
	struct netiucv_priv *priv = dev->driver_data;
	struct net_device *ndev = priv->conn->netdev;
	char         *e;
	int          bs1;

	IUCV_DBF_TEXT(trace, 3, __FUNCTION__);
	if (count >= 39)
		return -EINVAL;

	bs1 = simple_strtoul(buf, &e, 0);

	if (e && (!isspace(*e))) {
		PRINT_WARN("netiucv: Invalid character in buffer!\n");
		IUCV_DBF_TEXT_(setup, 2, "buffer_write: invalid char %c\n", *e);
		return -EINVAL;
	}
	if (bs1 > NETIUCV_BUFSIZE_MAX) {
		PRINT_WARN("netiucv: Given buffer size %d too large.\n",
			bs1);
		IUCV_DBF_TEXT_(setup, 2,
			"buffer_write: buffer size %d too large\n",
			bs1);
		return -EINVAL;
	}
	if ((ndev->flags & IFF_RUNNING) &&
	    (bs1 < (ndev->mtu + NETIUCV_HDRLEN + 2))) {
		PRINT_WARN("netiucv: Given buffer size %d too small.\n",
			bs1);
		IUCV_DBF_TEXT_(setup, 2,
			"buffer_write: buffer size %d too small\n",
			bs1);
		return -EINVAL;
	}
	if (bs1 < (576 + NETIUCV_HDRLEN + NETIUCV_HDRLEN)) {
		PRINT_WARN("netiucv: Given buffer size %d too small.\n",
			bs1);
		IUCV_DBF_TEXT_(setup, 2,
			"buffer_write: buffer size %d too small\n",
			bs1);
		return -EINVAL;
	}

	priv->conn->max_buffsize = bs1;
	if (!(ndev->flags & IFF_RUNNING))
		ndev->mtu = bs1 - NETIUCV_HDRLEN - NETIUCV_HDRLEN;

	return count;

}

static DEVICE_ATTR(buffer, 0644, buffer_show, buffer_write);

static ssize_t dev_fsm_show (struct device *dev, struct device_attribute *attr,
			     char *buf)
{
	struct netiucv_priv *priv = dev->driver_data;

	IUCV_DBF_TEXT(trace, 5, __FUNCTION__);
	return sprintf(buf, "%s\n", fsm_getstate_str(priv->fsm));
}

static DEVICE_ATTR(device_fsm_state, 0444, dev_fsm_show, NULL);

static ssize_t conn_fsm_show (struct device *dev,
			      struct device_attribute *attr, char *buf)
{
	struct netiucv_priv *priv = dev->driver_data;

	IUCV_DBF_TEXT(trace, 5, __FUNCTION__);
	return sprintf(buf, "%s\n", fsm_getstate_str(priv->conn->fsm));
}

static DEVICE_ATTR(connection_fsm_state, 0444, conn_fsm_show, NULL);

static ssize_t maxmulti_show (struct device *dev,
			      struct device_attribute *attr, char *buf)
{
	struct netiucv_priv *priv = dev->driver_data;

	IUCV_DBF_TEXT(trace, 5, __FUNCTION__);
	return sprintf(buf, "%ld\n", priv->conn->prof.maxmulti);
}

static ssize_t maxmulti_write (struct device *dev,
			       struct device_attribute *attr,
			       const char *buf, size_t count)
{
	struct netiucv_priv *priv = dev->driver_data;

	IUCV_DBF_TEXT(trace, 4, __FUNCTION__);
	priv->conn->prof.maxmulti = 0;
	return count;
}

static DEVICE_ATTR(max_tx_buffer_used, 0644, maxmulti_show, maxmulti_write);

static ssize_t maxcq_show (struct device *dev, struct device_attribute *attr,
			   char *buf)
{
	struct netiucv_priv *priv = dev->driver_data;

	IUCV_DBF_TEXT(trace, 5, __FUNCTION__);
	return sprintf(buf, "%ld\n", priv->conn->prof.maxcqueue);
}

static ssize_t maxcq_write (struct device *dev, struct device_attribute *attr,
			    const char *buf, size_t count)
{
	struct netiucv_priv *priv = dev->driver_data;

	IUCV_DBF_TEXT(trace, 4, __FUNCTION__);
	priv->conn->prof.maxcqueue = 0;
	return count;
}

static DEVICE_ATTR(max_chained_skbs, 0644, maxcq_show, maxcq_write);

static ssize_t sdoio_show (struct device *dev, struct device_attribute *attr,
			   char *buf)
{
	struct netiucv_priv *priv = dev->driver_data;

	IUCV_DBF_TEXT(trace, 5, __FUNCTION__);
	return sprintf(buf, "%ld\n", priv->conn->prof.doios_single);
}

static ssize_t sdoio_write (struct device *dev, struct device_attribute *attr,
			    const char *buf, size_t count)
{
	struct netiucv_priv *priv = dev->driver_data;

	IUCV_DBF_TEXT(trace, 4, __FUNCTION__);
	priv->conn->prof.doios_single = 0;
	return count;
}

static DEVICE_ATTR(tx_single_write_ops, 0644, sdoio_show, sdoio_write);

static ssize_t mdoio_show (struct device *dev, struct device_attribute *attr,
			   char *buf)
{
	struct netiucv_priv *priv = dev->driver_data;

	IUCV_DBF_TEXT(trace, 5, __FUNCTION__);
	return sprintf(buf, "%ld\n", priv->conn->prof.doios_multi);
}

static ssize_t mdoio_write (struct device *dev, struct device_attribute *attr,
			    const char *buf, size_t count)
{
	struct netiucv_priv *priv = dev->driver_data;

	IUCV_DBF_TEXT(trace, 5, __FUNCTION__);
	priv->conn->prof.doios_multi = 0;
	return count;
}

static DEVICE_ATTR(tx_multi_write_ops, 0644, mdoio_show, mdoio_write);

static ssize_t txlen_show (struct device *dev, struct device_attribute *attr,
			   char *buf)
{
	struct netiucv_priv *priv = dev->driver_data;

	IUCV_DBF_TEXT(trace, 5, __FUNCTION__);
	return sprintf(buf, "%ld\n", priv->conn->prof.txlen);
}

static ssize_t txlen_write (struct device *dev, struct device_attribute *attr,
			    const char *buf, size_t count)
{
	struct netiucv_priv *priv = dev->driver_data;

	IUCV_DBF_TEXT(trace, 4, __FUNCTION__);
	priv->conn->prof.txlen = 0;
	return count;
}