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-rw-r--r--drivers/net/loopback.c173
1 files changed, 117 insertions, 56 deletions
diff --git a/drivers/net/loopback.c b/drivers/net/loopback.c
index 2df7f60fe052..1fb6ce6843ad 100644
--- a/drivers/net/loopback.c
+++ b/drivers/net/loopback.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
/*
* INET An implementation of the TCP/IP protocol suite for the LINUX
* operating system. INET is implemented using the BSD Socket
@@ -22,11 +23,6 @@
* 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>
@@ -48,6 +44,7 @@
#include <linux/etherdevice.h>
#include <linux/skbuff.h>
#include <linux/ethtool.h>
+#include <net/sch_generic.h>
#include <net/sock.h>
#include <net/checksum.h>
#include <linux/if_ether.h> /* For the statistics structure. */
@@ -57,52 +54,52 @@
#include <linux/percpu.h>
#include <linux/net_tstamp.h>
#include <net/net_namespace.h>
+#include <net/netdev_lock.h>
#include <linux/u64_stats_sync.h>
+/* blackhole_netdev - a device used for dsts that are marked expired!
+ * This is global device (instead of per-net-ns) since it's not needed
+ * to be per-ns and gets initialized at boot time.
+ */
+struct net_device *blackhole_netdev;
+EXPORT_SYMBOL(blackhole_netdev);
+
/* 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_clear_tstamp(skb);
skb_orphan(skb);
- /* Before queueing this packet to netif_rx(),
+ /* 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);
- }
+ if (likely(__netif_rx(skb) == NET_RX_SUCCESS))
+ dev_lstats_add(dev, len);
return NETDEV_TX_OK;
}
-static void loopback_get_stats64(struct net_device *dev,
- struct rtnl_link_stats64 *stats)
+void dev_lstats_read(struct net_device *dev, u64 *packets, u64 *bytes)
{
- u64 bytes = 0;
- u64 packets = 0;
int i;
+ *packets = 0;
+ *bytes = 0;
+
for_each_possible_cpu(i) {
const struct pcpu_lstats *lb_stats;
u64 tbytes, tpackets;
@@ -110,13 +107,23 @@ static void loopback_get_stats64(struct net_device *dev,
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;
+ start = u64_stats_fetch_begin(&lb_stats->syncp);
+ tpackets = u64_stats_read(&lb_stats->packets);
+ tbytes = u64_stats_read(&lb_stats->bytes);
+ } while (u64_stats_fetch_retry(&lb_stats->syncp, start));
+ *bytes += tbytes;
+ *packets += tpackets;
}
+}
+EXPORT_SYMBOL(dev_lstats_read);
+
+static void loopback_get_stats64(struct net_device *dev,
+ struct rtnl_link_stats64 *stats)
+{
+ u64 packets, bytes;
+
+ dev_lstats_read(dev, &packets, &bytes);
+
stats->rx_packets = packets;
stats->tx_packets = packets;
stats->rx_bytes = bytes;
@@ -128,35 +135,20 @@ 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,
+ .get_ts_info = ethtool_op_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;
+ netdev_lockdep_set_classes(dev);
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 = {
@@ -166,18 +158,22 @@ static const struct net_device_ops loopback_ops = {
.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)
+static void gen_lo_setup(struct net_device *dev,
+ unsigned int mtu,
+ const struct ethtool_ops *eth_ops,
+ const struct header_ops *hdr_ops,
+ const struct net_device_ops *dev_ops,
+ void (*dev_destructor)(struct net_device *dev))
{
- dev->mtu = 64 * 1024;
+ dev->mtu = mtu;
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;
+ dev->lltx = true;
+ dev->netns_immutable = true;
netif_keep_dst(dev);
dev->hw_features = NETIF_F_GSO_SOFTWARE;
dev->features = NETIF_F_SG | NETIF_F_FRAGLIST
@@ -186,15 +182,25 @@ static void loopback_setup(struct net_device *dev)
| 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->ethtool_ops = eth_ops;
+ dev->header_ops = hdr_ops;
+ dev->netdev_ops = dev_ops;
dev->needs_free_netdev = true;
- dev->priv_destructor = loopback_dev_free;
+ dev->pcpu_stat_type = NETDEV_PCPU_STAT_LSTATS;
+ dev->priv_destructor = dev_destructor;
+
+ netif_set_tso_max_size(dev, GSO_MAX_SIZE);
+}
+
+/* The loopback device is special. There is only one instance
+ * per network namespace.
+ */
+static void loopback_setup(struct net_device *dev)
+{
+ gen_lo_setup(dev, (64 * 1024), &loopback_ethtool_ops, &eth_header_ops,
+ &loopback_ops, loopback_dev_free);
}
/* Setup and register the loopback device. */
@@ -204,7 +210,7 @@ static __net_init int loopback_net_init(struct net *net)
int err;
err = -ENOMEM;
- dev = alloc_netdev(0, "lo", NET_NAME_UNKNOWN, loopback_setup);
+ dev = alloc_netdev(0, "lo", NET_NAME_PREDICTABLE, loopback_setup);
if (!dev)
goto out;
@@ -229,3 +235,58 @@ out:
struct pernet_operations __net_initdata loopback_net_ops = {
.init = loopback_net_init,
};
+
+/* blackhole netdevice */
+static netdev_tx_t blackhole_netdev_xmit(struct sk_buff *skb,
+ struct net_device *dev)
+{
+ kfree_skb(skb);
+ net_warn_ratelimited("%s(): Dropping skb.\n", __func__);
+ return NETDEV_TX_OK;
+}
+
+static int blackhole_neigh_output(struct neighbour *n, struct sk_buff *skb)
+{
+ kfree_skb(skb);
+ return 0;
+}
+
+static int blackhole_neigh_construct(struct net_device *dev,
+ struct neighbour *n)
+{
+ n->output = blackhole_neigh_output;
+ return 0;
+}
+
+static const struct net_device_ops blackhole_netdev_ops = {
+ .ndo_start_xmit = blackhole_netdev_xmit,
+ .ndo_neigh_construct = blackhole_neigh_construct,
+};
+
+/* This is a dst-dummy device used specifically for invalidated
+ * DSTs and unlike loopback, this is not per-ns.
+ */
+static void blackhole_netdev_setup(struct net_device *dev)
+{
+ gen_lo_setup(dev, ETH_MIN_MTU, NULL, NULL, &blackhole_netdev_ops, NULL);
+}
+
+/* Setup and register the blackhole_netdev. */
+static int __init blackhole_netdev_init(void)
+{
+ blackhole_netdev = alloc_netdev(0, "blackhole_dev", NET_NAME_UNKNOWN,
+ blackhole_netdev_setup);
+ if (!blackhole_netdev)
+ return -ENOMEM;
+
+ rtnl_net_lock(&init_net);
+ dev_init_scheduler(blackhole_netdev);
+ dev_activate(blackhole_netdev);
+ rtnl_net_unlock(&init_net);
+
+ blackhole_netdev->flags |= IFF_UP | IFF_RUNNING;
+
+ return 0;
+}
+
+device_initcall(blackhole_netdev_init);
generated by cgit (git 2.34.1) at 2025-12-22 12:24:00 +0000