File-copy from v4.4.100

This is the result of 'cp' from a linux-stable tree with the 'v4.4.100'
tag checked out (commit 26d6298789e695c9f627ce49a7bbd2286405798a) on
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git

Please refer to that tree for all history prior to this point.

Change-Id: I8a9ee2aea93cd29c52c847d0ce33091a73ae6afe
diff --git a/net/irda/irlan/irlan_eth.c b/net/irda/irlan/irlan_eth.c
new file mode 100644
index 0000000..fcfbe57
--- /dev/null
+++ b/net/irda/irlan/irlan_eth.c
@@ -0,0 +1,340 @@
+/*********************************************************************
+ *
+ * Filename:      irlan_eth.c
+ * Version:
+ * Description:
+ * Status:        Experimental.
+ * Author:        Dag Brattli <dagb@cs.uit.no>
+ * Created at:    Thu Oct 15 08:37:58 1998
+ * Modified at:   Tue Mar 21 09:06:41 2000
+ * Modified by:   Dag Brattli <dagb@cs.uit.no>
+ * Sources:       skeleton.c by Donald Becker <becker@CESDIS.gsfc.nasa.gov>
+ *                slip.c by Laurence Culhane,   <loz@holmes.demon.co.uk>
+ *                          Fred N. van Kempen, <waltje@uwalt.nl.mugnet.org>
+ *
+ *     Copyright (c) 1998-2000 Dag Brattli, All Rights Reserved.
+ *
+ *     This program is free software; you can redistribute it and/or
+ *     modify it under the terms of the GNU General Public License as
+ *     published by the Free Software Foundation; either version 2 of
+ *     the License, or (at your option) any later version.
+ *
+ *     Neither Dag Brattli nor University of Tromsø admit liability nor
+ *     provide warranty for any of this software. This material is
+ *     provided "AS-IS" and at no charge.
+ *
+ ********************************************************************/
+
+#include <linux/netdevice.h>
+#include <linux/etherdevice.h>
+#include <linux/inetdevice.h>
+#include <linux/if_arp.h>
+#include <linux/module.h>
+#include <linux/sched.h>
+#include <net/arp.h>
+
+#include <net/irda/irda.h>
+#include <net/irda/irmod.h>
+#include <net/irda/irlan_common.h>
+#include <net/irda/irlan_client.h>
+#include <net/irda/irlan_event.h>
+#include <net/irda/irlan_eth.h>
+
+static int  irlan_eth_open(struct net_device *dev);
+static int  irlan_eth_close(struct net_device *dev);
+static netdev_tx_t  irlan_eth_xmit(struct sk_buff *skb,
+					 struct net_device *dev);
+static void irlan_eth_set_multicast_list(struct net_device *dev);
+
+static const struct net_device_ops irlan_eth_netdev_ops = {
+	.ndo_open		= irlan_eth_open,
+	.ndo_stop		= irlan_eth_close,
+	.ndo_start_xmit		= irlan_eth_xmit,
+	.ndo_set_rx_mode	= irlan_eth_set_multicast_list,
+	.ndo_change_mtu		= eth_change_mtu,
+	.ndo_validate_addr	= eth_validate_addr,
+};
+
+/*
+ * Function irlan_eth_setup (dev)
+ *
+ *    The network device initialization function.
+ *
+ */
+static void irlan_eth_setup(struct net_device *dev)
+{
+	ether_setup(dev);
+
+	dev->netdev_ops		= &irlan_eth_netdev_ops;
+	dev->destructor		= free_netdev;
+
+
+	/*
+	 * Lets do all queueing in IrTTP instead of this device driver.
+	 * Queueing here as well can introduce some strange latency
+	 * problems, which we will avoid by setting the queue size to 0.
+	 */
+	/*
+	 * The bugs in IrTTP and IrLAN that created this latency issue
+	 * have now been fixed, and we can propagate flow control properly
+	 * to the network layer. However, this requires a minimal queue of
+	 * packets for the device.
+	 * Without flow control, the Tx Queue is 14 (ttp) + 0 (dev) = 14
+	 * With flow control, the Tx Queue is 7 (ttp) + 4 (dev) = 11
+	 * See irlan_eth_flow_indication()...
+	 * Note : this number was randomly selected and would need to
+	 * be adjusted.
+	 * Jean II */
+	dev->tx_queue_len = 4;
+}
+
+/*
+ * Function alloc_irlandev
+ *
+ *    Allocate network device and control block
+ *
+ */
+struct net_device *alloc_irlandev(const char *name)
+{
+	return alloc_netdev(sizeof(struct irlan_cb), name, NET_NAME_UNKNOWN,
+			    irlan_eth_setup);
+}
+
+/*
+ * Function irlan_eth_open (dev)
+ *
+ *    Network device has been opened by user
+ *
+ */
+static int irlan_eth_open(struct net_device *dev)
+{
+	struct irlan_cb *self = netdev_priv(dev);
+
+	/* Ready to play! */
+	netif_stop_queue(dev); /* Wait until data link is ready */
+
+	/* We are now open, so time to do some work */
+	self->disconnect_reason = 0;
+	irlan_client_wakeup(self, self->saddr, self->daddr);
+
+	/* Make sure we have a hardware address before we return,
+	   so DHCP clients gets happy */
+	return wait_event_interruptible(self->open_wait,
+					!self->tsap_data->connected);
+}
+
+/*
+ * Function irlan_eth_close (dev)
+ *
+ *    Stop the ether network device, his function will usually be called by
+ *    ifconfig down. We should now disconnect the link, We start the
+ *    close timer, so that the instance will be removed if we are unable
+ *    to discover the remote device after the disconnect.
+ */
+static int irlan_eth_close(struct net_device *dev)
+{
+	struct irlan_cb *self = netdev_priv(dev);
+
+	/* Stop device */
+	netif_stop_queue(dev);
+
+	irlan_close_data_channel(self);
+	irlan_close_tsaps(self);
+
+	irlan_do_client_event(self, IRLAN_LMP_DISCONNECT, NULL);
+	irlan_do_provider_event(self, IRLAN_LMP_DISCONNECT, NULL);
+
+	/* Remove frames queued on the control channel */
+	skb_queue_purge(&self->client.txq);
+
+	self->client.tx_busy = 0;
+
+	return 0;
+}
+
+/*
+ * Function irlan_eth_tx (skb)
+ *
+ *    Transmits ethernet frames over IrDA link.
+ *
+ */
+static netdev_tx_t irlan_eth_xmit(struct sk_buff *skb,
+					struct net_device *dev)
+{
+	struct irlan_cb *self = netdev_priv(dev);
+	int ret;
+	unsigned int len;
+
+	/* skb headroom large enough to contain all IrDA-headers? */
+	if ((skb_headroom(skb) < self->max_header_size) || (skb_shared(skb))) {
+		struct sk_buff *new_skb =
+			skb_realloc_headroom(skb, self->max_header_size);
+
+		/*  We have to free the original skb anyway */
+		dev_kfree_skb(skb);
+
+		/* Did the realloc succeed? */
+		if (new_skb == NULL)
+			return NETDEV_TX_OK;
+
+		/* Use the new skb instead */
+		skb = new_skb;
+	}
+
+	dev->trans_start = jiffies;
+
+	len = skb->len;
+	/* Now queue the packet in the transport layer */
+	if (self->use_udata)
+		ret = irttp_udata_request(self->tsap_data, skb);
+	else
+		ret = irttp_data_request(self->tsap_data, skb);
+
+	if (ret < 0) {
+		/*
+		 * IrTTPs tx queue is full, so we just have to
+		 * drop the frame! You might think that we should
+		 * just return -1 and don't deallocate the frame,
+		 * but that is dangerous since it's possible that
+		 * we have replaced the original skb with a new
+		 * one with larger headroom, and that would really
+		 * confuse do_dev_queue_xmit() in dev.c! I have
+		 * tried :-) DB
+		 */
+		/* irttp_data_request already free the packet */
+		dev->stats.tx_dropped++;
+	} else {
+		dev->stats.tx_packets++;
+		dev->stats.tx_bytes += len;
+	}
+
+	return NETDEV_TX_OK;
+}
+
+/*
+ * Function irlan_eth_receive (handle, skb)
+ *
+ *    This function gets the data that is received on the data channel
+ *
+ */
+int irlan_eth_receive(void *instance, void *sap, struct sk_buff *skb)
+{
+	struct irlan_cb *self = instance;
+	struct net_device *dev = self->dev;
+
+	if (skb == NULL) {
+		dev->stats.rx_dropped++;
+		return 0;
+	}
+	if (skb->len < ETH_HLEN) {
+		pr_debug("%s() : IrLAN frame too short (%d)\n",
+			 __func__, skb->len);
+		dev->stats.rx_dropped++;
+		dev_kfree_skb(skb);
+		return 0;
+	}
+
+	/*
+	 * Adopt this frame! Important to set all these fields since they
+	 * might have been previously set by the low level IrDA network
+	 * device driver
+	 */
+	skb->protocol = eth_type_trans(skb, dev); /* Remove eth header */
+
+	dev->stats.rx_packets++;
+	dev->stats.rx_bytes += skb->len;
+
+	netif_rx(skb);   /* Eat it! */
+
+	return 0;
+}
+
+/*
+ * Function irlan_eth_flow (status)
+ *
+ *    Do flow control between IP/Ethernet and IrLAN/IrTTP. This is done by
+ *    controlling the queue stop/start.
+ *
+ * The IrDA link layer has the advantage to have flow control, and
+ * IrTTP now properly handles that. Flow controlling the higher layers
+ * prevent us to drop Tx packets in here (up to 15% for a TCP socket,
+ * more for UDP socket).
+ * Also, this allow us to reduce the overall transmit queue, which means
+ * less latency in case of mixed traffic.
+ * Jean II
+ */
+void irlan_eth_flow_indication(void *instance, void *sap, LOCAL_FLOW flow)
+{
+	struct irlan_cb *self;
+	struct net_device *dev;
+
+	self = instance;
+
+	IRDA_ASSERT(self != NULL, return;);
+	IRDA_ASSERT(self->magic == IRLAN_MAGIC, return;);
+
+	dev = self->dev;
+
+	IRDA_ASSERT(dev != NULL, return;);
+
+	pr_debug("%s() : flow %s ; running %d\n", __func__,
+		 flow == FLOW_STOP ? "FLOW_STOP" : "FLOW_START",
+		 netif_running(dev));
+
+	switch (flow) {
+	case FLOW_STOP:
+		/* IrTTP is full, stop higher layers */
+		netif_stop_queue(dev);
+		break;
+	case FLOW_START:
+	default:
+		/* Tell upper layers that its time to transmit frames again */
+		/* Schedule network layer */
+		netif_wake_queue(dev);
+		break;
+	}
+}
+
+/*
+ * Function set_multicast_list (dev)
+ *
+ *    Configure the filtering of the device
+ *
+ */
+#define HW_MAX_ADDRS 4 /* Must query to get it! */
+static void irlan_eth_set_multicast_list(struct net_device *dev)
+{
+	struct irlan_cb *self = netdev_priv(dev);
+
+	/* Check if data channel has been connected yet */
+	if (self->client.state != IRLAN_DATA) {
+		pr_debug("%s(), delaying!\n", __func__);
+		return;
+	}
+
+	if (dev->flags & IFF_PROMISC) {
+		/* Enable promiscuous mode */
+		net_warn_ratelimited("Promiscuous mode not implemented by IrLAN!\n");
+	} else if ((dev->flags & IFF_ALLMULTI) ||
+		 netdev_mc_count(dev) > HW_MAX_ADDRS) {
+		/* Disable promiscuous mode, use normal mode. */
+		pr_debug("%s(), Setting multicast filter\n", __func__);
+		/* hardware_set_filter(NULL); */
+
+		irlan_set_multicast_filter(self, TRUE);
+	} else if (!netdev_mc_empty(dev)) {
+		pr_debug("%s(), Setting multicast filter\n", __func__);
+		/* Walk the address list, and load the filter */
+		/* hardware_set_filter(dev->mc_list); */
+
+		irlan_set_multicast_filter(self, TRUE);
+	} else {
+		pr_debug("%s(), Clearing multicast filter\n", __func__);
+		irlan_set_multicast_filter(self, FALSE);
+	}
+
+	if (dev->flags & IFF_BROADCAST)
+		irlan_set_broadcast_filter(self, TRUE);
+	else
+		irlan_set_broadcast_filter(self, FALSE);
+}