Adding upstream version 4.19.249.upstream/4.19.249

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 237 insertions, 0 deletions

diff --git a/drivers/net/loopback.c b/drivers/net/loopback.c
new file mode 100644
index 000000000..d192936b7
--- /dev/null
+++ b/drivers/net/loopback.c
@@ -0,0 +1,237 @@
+/*
+ * INET		An implementation of the TCP/IP protocol suite for the LINUX
+ *		operating system.  INET is implemented using the  BSD Socket
+ *		interface as the means of communication with the user level.
+ *
+ *		Pseudo-driver for the loopback interface.
+ *
+ * Version:	@(#)loopback.c	1.0.4b	08/16/93
+ *
+ * Authors:	Ross Biro
+ *		Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
+ *		Donald Becker, <becker@scyld.com>
+ *
+ *		Alan Cox	:	Fixed oddments for NET3.014
+ *		Alan Cox	:	Rejig for NET3.029 snap #3
+ *		Alan Cox	:	Fixed NET3.029 bugs and sped up
+ *		Larry McVoy	:	Tiny tweak to double performance
+ *		Alan Cox	:	Backed out LMV's tweak - the linux mm
+ *					can't take it...
+ *              Michael Griffith:       Don't bother computing the checksums
+ *                                      on packets received on the loopback
+ *                                      interface.
+ *		Alexey Kuznetsov:	Potential hang under some extreme
+ *					cases removed.
+ *
+ *		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.
+ */
+#include <linux/kernel.h>
+#include <linux/jiffies.h>
+#include <linux/module.h>
+#include <linux/interrupt.h>
+#include <linux/fs.h>
+#include <linux/types.h>
+#include <linux/string.h>
+#include <linux/socket.h>
+#include <linux/errno.h>
+#include <linux/fcntl.h>
+#include <linux/in.h>
+
+#include <linux/uaccess.h>
+#include <linux/io.h>
+
+#include <linux/inet.h>
+#include <linux/netdevice.h>
+#include <linux/etherdevice.h>
+#include <linux/skbuff.h>
+#include <linux/ethtool.h>
+#include <net/sock.h>
+#include <net/checksum.h>
+#include <linux/if_ether.h>	/* For the statistics structure. */
+#include <linux/if_arp.h>	/* For ARPHRD_ETHER */
+#include <linux/ip.h>
+#include <linux/tcp.h>
+#include <linux/percpu.h>
+#include <linux/net_tstamp.h>
+#include <net/net_namespace.h>
+#include <linux/u64_stats_sync.h>
+
+struct pcpu_lstats {
+	u64			packets;
+	u64			bytes;
+	struct u64_stats_sync	syncp;
+};
+
+/* The higher levels take care of making this non-reentrant (it's
+ * called with bh's disabled).
+ */
+static netdev_tx_t loopback_xmit(struct sk_buff *skb,
+				 struct net_device *dev)
+{
+	struct pcpu_lstats *lb_stats;
+	int len;
+
+	skb_tx_timestamp(skb);
+
+	/* do not fool net_timestamp_check() with various clock bases */
+	skb->tstamp = 0;
+
+	skb_orphan(skb);
+
+	/* Before queueing this packet to netif_rx(),
+	 * make sure dst is refcounted.
+	 */
+	skb_dst_force(skb);
+
+	skb->protocol = eth_type_trans(skb, dev);
+
+	/* it's OK to use per_cpu_ptr() because BHs are off */
+	lb_stats = this_cpu_ptr(dev->lstats);
+
+	len = skb->len;
+	if (likely(netif_rx(skb) == NET_RX_SUCCESS)) {
+		u64_stats_update_begin(&lb_stats->syncp);
+		lb_stats->bytes += len;
+		lb_stats->packets++;
+		u64_stats_update_end(&lb_stats->syncp);
+	}
+
+	return NETDEV_TX_OK;
+}
+
+static void loopback_get_stats64(struct net_device *dev,
+				 struct rtnl_link_stats64 *stats)
+{
+	u64 bytes = 0;
+	u64 packets = 0;
+	int i;
+
+	for_each_possible_cpu(i) {
+		const struct pcpu_lstats *lb_stats;
+		u64 tbytes, tpackets;
+		unsigned int start;
+
+		lb_stats = per_cpu_ptr(dev->lstats, i);
+		do {
+			start = u64_stats_fetch_begin_irq(&lb_stats->syncp);
+			tbytes = lb_stats->bytes;
+			tpackets = lb_stats->packets;
+		} while (u64_stats_fetch_retry_irq(&lb_stats->syncp, start));
+		bytes   += tbytes;
+		packets += tpackets;
+	}
+	stats->rx_packets = packets;
+	stats->tx_packets = packets;
+	stats->rx_bytes   = bytes;
+	stats->tx_bytes   = bytes;
+}
+
+static u32 always_on(struct net_device *dev)
+{
+	return 1;
+}
+
+static int loopback_get_ts_info(struct net_device *netdev,
+				struct ethtool_ts_info *ts_info)
+{
+	ts_info->so_timestamping = SOF_TIMESTAMPING_TX_SOFTWARE |
+				   SOF_TIMESTAMPING_RX_SOFTWARE |
+				   SOF_TIMESTAMPING_SOFTWARE;
+
+	ts_info->phc_index = -1;
+
+	return 0;
+};
+
+static const struct ethtool_ops loopback_ethtool_ops = {
+	.get_link		= always_on,
+	.get_ts_info		= loopback_get_ts_info,
+};
+
+static int loopback_dev_init(struct net_device *dev)
+{
+	dev->lstats = netdev_alloc_pcpu_stats(struct pcpu_lstats);
+	if (!dev->lstats)
+		return -ENOMEM;
+	return 0;
+}
+
+static void loopback_dev_free(struct net_device *dev)
+{
+	dev_net(dev)->loopback_dev = NULL;
+	free_percpu(dev->lstats);
+}
+
+static const struct net_device_ops loopback_ops = {
+	.ndo_init        = loopback_dev_init,
+	.ndo_start_xmit  = loopback_xmit,
+	.ndo_get_stats64 = loopback_get_stats64,
+	.ndo_set_mac_address = eth_mac_addr,
+};
+
+/* The loopback device is special. There is only one instance
+ * per network namespace.
+ */
+static void loopback_setup(struct net_device *dev)
+{
+	dev->mtu		= 64 * 1024;
+	dev->hard_header_len	= ETH_HLEN;	/* 14	*/
+	dev->min_header_len	= ETH_HLEN;	/* 14	*/
+	dev->addr_len		= ETH_ALEN;	/* 6	*/
+	dev->type		= ARPHRD_LOOPBACK;	/* 0x0001*/
+	dev->flags		= IFF_LOOPBACK;
+	dev->priv_flags		|= IFF_LIVE_ADDR_CHANGE | IFF_NO_QUEUE;
+	netif_keep_dst(dev);
+	dev->hw_features	= NETIF_F_GSO_SOFTWARE;
+	dev->features		= NETIF_F_SG | NETIF_F_FRAGLIST
+		| NETIF_F_GSO_SOFTWARE
+		| NETIF_F_HW_CSUM
+		| NETIF_F_RXCSUM
+		| NETIF_F_SCTP_CRC
+		| NETIF_F_HIGHDMA
+		| NETIF_F_LLTX
+		| NETIF_F_NETNS_LOCAL
+		| NETIF_F_VLAN_CHALLENGED
+		| NETIF_F_LOOPBACK;
+	dev->ethtool_ops	= &loopback_ethtool_ops;
+	dev->header_ops		= &eth_header_ops;
+	dev->netdev_ops		= &loopback_ops;
+	dev->needs_free_netdev	= true;
+	dev->priv_destructor	= loopback_dev_free;
+}
+
+/* Setup and register the loopback device. */
+static __net_init int loopback_net_init(struct net *net)
+{
+	struct net_device *dev;
+	int err;
+
+	err = -ENOMEM;
+	dev = alloc_netdev(0, "lo", NET_NAME_UNKNOWN, loopback_setup);
+	if (!dev)
+		goto out;
+
+	dev_net_set(dev, net);
+	err = register_netdev(dev);
+	if (err)
+		goto out_free_netdev;
+
+	BUG_ON(dev->ifindex != LOOPBACK_IFINDEX);
+	net->loopback_dev = dev;
+	return 0;
+
+out_free_netdev:
+	free_netdev(dev);
+out:
+	if (net_eq(net, &init_net))
+		panic("loopback: Failed to register netdevice: %d\n", err);
+	return err;
+}
+
+/* Registered in net/core/dev.c */
+struct pernet_operations __net_initdata loopback_net_ops = {
+	.init = loopback_net_init,
+};