diff options
Diffstat (limited to 'drivers/net/loopback.c')
| -rw-r--r-- | drivers/net/loopback.c | 205 |
1 files changed, 138 insertions, 67 deletions
diff --git a/drivers/net/loopback.c b/drivers/net/loopback.c index fcbf680c3e62..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 @@ -13,7 +14,7 @@ * * Alan Cox : Fixed oddments for NET3.014 * Alan Cox : Rejig for NET3.029 snap #3 - * Alan Cox : Fixed NET3.029 bugs and sped up + * 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... @@ -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> @@ -39,16 +35,16 @@ #include <linux/errno.h> #include <linux/fcntl.h> #include <linux/in.h> -#include <linux/init.h> -#include <asm/uaccess.h> -#include <asm/io.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/sch_generic.h> #include <net/sock.h> #include <net/checksum.h> #include <linux/if_ether.h> /* For the statistics structure. */ @@ -56,55 +52,54 @@ #include <linux/ip.h> #include <linux/tcp.h> #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> -struct pcpu_lstats { - u64 packets; - u64 bytes; - struct u64_stats_sync syncp; -}; +/* 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 +/* 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_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 struct rtnl_link_stats64 *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; @@ -112,18 +107,27 @@ static struct rtnl_link_stats64 *loopback_get_stats64(struct net_device *dev, lb_stats = per_cpu_ptr(dev->lstats, i); do { - start = u64_stats_fetch_begin_bh(&lb_stats->syncp); - tbytes = lb_stats->bytes; - tpackets = lb_stats->packets; - } while (u64_stats_fetch_retry_bh(&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; stats->tx_bytes = bytes; - return stats; } static u32 always_on(struct net_device *dev) @@ -133,57 +137,70 @@ static u32 always_on(struct net_device *dev) static const struct ethtool_ops loopback_ethtool_ops = { .get_link = always_on, + .get_ts_info = ethtool_op_get_ts_info, }; static int loopback_dev_init(struct net_device *dev) { - dev->lstats = alloc_percpu(struct pcpu_lstats); - if (!dev->lstats) - return -ENOMEM; - + netdev_lockdep_set_classes(dev); return 0; } static void loopback_dev_free(struct net_device *dev) { - free_percpu(dev->lstats); - free_netdev(dev); + dev_net(dev)->loopback_dev = NULL; } static const struct net_device_ops loopback_ops = { - .ndo_init = loopback_dev_init, - .ndo_start_xmit= loopback_xmit, + .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) +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->tx_queue_len = 0; dev->type = ARPHRD_LOOPBACK; /* 0x0001*/ dev->flags = IFF_LOOPBACK; - dev->priv_flags &= ~IFF_XMIT_DST_RELEASE; - dev->hw_features = NETIF_F_ALL_TSO | NETIF_F_UFO; - dev->features = NETIF_F_SG | NETIF_F_FRAGLIST - | NETIF_F_ALL_TSO - | NETIF_F_UFO + 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 + | 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 = ð_header_ops; - dev->netdev_ops = &loopback_ops; - dev->destructor = loopback_dev_free; + dev->ethtool_ops = eth_ops; + dev->header_ops = hdr_ops; + dev->netdev_ops = dev_ops; + dev->needs_free_netdev = true; + 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, ð_header_ops, + &loopback_ops, loopback_dev_free); } /* Setup and register the loopback device. */ @@ -193,7 +210,7 @@ static __net_init int loopback_net_init(struct net *net) int err; err = -ENOMEM; - dev = alloc_netdev(0, "lo", loopback_setup); + dev = alloc_netdev(0, "lo", NET_NAME_PREDICTABLE, loopback_setup); if (!dev) goto out; @@ -206,7 +223,6 @@ static __net_init int loopback_net_init(struct net *net) net->loopback_dev = dev; return 0; - out_free_netdev: free_netdev(dev); out: @@ -217,5 +233,60 @@ out: /* Registered in net/core/dev.c */ struct pernet_operations __net_initdata loopback_net_ops = { - .init = loopback_net_init, + .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); |