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linux-next/drivers/net/vrf.c

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/*
* vrf.c: device driver to encapsulate a VRF space
*
* Copyright (c) 2015 Cumulus Networks. All rights reserved.
* Copyright (c) 2015 Shrijeet Mukherjee <shm@cumulusnetworks.com>
* Copyright (c) 2015 David Ahern <dsa@cumulusnetworks.com>
*
* Based on dummy, team and ipvlan drivers
*
* 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/module.h>
#include <linux/kernel.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/ip.h>
#include <linux/init.h>
#include <linux/moduleparam.h>
#include <linux/netfilter.h>
#include <linux/rtnetlink.h>
#include <net/rtnetlink.h>
#include <linux/u64_stats_sync.h>
#include <linux/hashtable.h>
#include <linux/inetdevice.h>
#include <net/arp.h>
#include <net/ip.h>
#include <net/ip_fib.h>
#include <net/ip6_fib.h>
#include <net/ip6_route.h>
#include <net/route.h>
#include <net/addrconf.h>
#include <net/l3mdev.h>
#include <net/fib_rules.h>
#include <net/netns/generic.h>
#define DRV_NAME "vrf"
#define DRV_VERSION "1.0"
#define FIB_RULE_PREF 1000 /* default preference for FIB rules */
static unsigned int vrf_net_id;
struct net_vrf {
struct rtable __rcu *rth;
struct rt6_info __rcu *rt6;
#if IS_ENABLED(CONFIG_IPV6)
struct fib6_table *fib6_table;
#endif
u32 tb_id;
};
struct pcpu_dstats {
u64 tx_pkts;
u64 tx_bytes;
u64 tx_drps;
u64 rx_pkts;
u64 rx_bytes;
net: vrf: ipv4 support for local traffic to local addresses Add support for locally originated traffic to VRF-local addresses. If destination device for an skb is the loopback or VRF device then set its dst to a local version of the VRF cached dst_entry and call netif_rx to insert the packet onto the rx queue - similar to what is done for loopback. This patch handles IPv4 support; follow on patch handles IPv6. With this patch, ping, tcp and udp packets to a local IPv4 address are successfully routed: $ ip addr show dev eth1 4: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast master red state UP group default qlen 1000 link/ether 02:e0:f9:1c:b9:74 brd ff:ff:ff:ff:ff:ff inet 10.100.1.1/24 brd 10.100.1.255 scope global eth1 valid_lft forever preferred_lft forever inet6 2100:1::1/120 scope global valid_lft forever preferred_lft forever inet6 fe80::e0:f9ff:fe1c:b974/64 scope link valid_lft forever preferred_lft forever $ ping -c1 -I red 10.100.1.1 ping: Warning: source address might be selected on device other than red. PING 10.100.1.1 (10.100.1.1) from 10.100.1.1 red: 56(84) bytes of data. 64 bytes from 10.100.1.1: icmp_seq=1 ttl=64 time=0.057 ms This patch also enables use of IPv4 loopback address on the VRF device: $ ip addr add dev red 127.0.0.1/8 $ ping -c1 -I red 127.0.0.1 PING 127.0.0.1 (127.0.0.1) from 127.0.0.1 red: 56(84) bytes of data. 64 bytes from 127.0.0.1: icmp_seq=1 ttl=64 time=0.058 ms Signed-off-by: David Ahern <dsa@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-07 11:50:39 +08:00
u64 rx_drps;
struct u64_stats_sync syncp;
};
net: vrf: ipv4 support for local traffic to local addresses Add support for locally originated traffic to VRF-local addresses. If destination device for an skb is the loopback or VRF device then set its dst to a local version of the VRF cached dst_entry and call netif_rx to insert the packet onto the rx queue - similar to what is done for loopback. This patch handles IPv4 support; follow on patch handles IPv6. With this patch, ping, tcp and udp packets to a local IPv4 address are successfully routed: $ ip addr show dev eth1 4: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast master red state UP group default qlen 1000 link/ether 02:e0:f9:1c:b9:74 brd ff:ff:ff:ff:ff:ff inet 10.100.1.1/24 brd 10.100.1.255 scope global eth1 valid_lft forever preferred_lft forever inet6 2100:1::1/120 scope global valid_lft forever preferred_lft forever inet6 fe80::e0:f9ff:fe1c:b974/64 scope link valid_lft forever preferred_lft forever $ ping -c1 -I red 10.100.1.1 ping: Warning: source address might be selected on device other than red. PING 10.100.1.1 (10.100.1.1) from 10.100.1.1 red: 56(84) bytes of data. 64 bytes from 10.100.1.1: icmp_seq=1 ttl=64 time=0.057 ms This patch also enables use of IPv4 loopback address on the VRF device: $ ip addr add dev red 127.0.0.1/8 $ ping -c1 -I red 127.0.0.1 PING 127.0.0.1 (127.0.0.1) from 127.0.0.1 red: 56(84) bytes of data. 64 bytes from 127.0.0.1: icmp_seq=1 ttl=64 time=0.058 ms Signed-off-by: David Ahern <dsa@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-07 11:50:39 +08:00
static void vrf_rx_stats(struct net_device *dev, int len)
{
struct pcpu_dstats *dstats = this_cpu_ptr(dev->dstats);
u64_stats_update_begin(&dstats->syncp);
dstats->rx_pkts++;
dstats->rx_bytes += len;
u64_stats_update_end(&dstats->syncp);
}
static void vrf_tx_error(struct net_device *vrf_dev, struct sk_buff *skb)
{
vrf_dev->stats.tx_errors++;
kfree_skb(skb);
}
static void vrf_get_stats64(struct net_device *dev,
struct rtnl_link_stats64 *stats)
{
int i;
for_each_possible_cpu(i) {
const struct pcpu_dstats *dstats;
u64 tbytes, tpkts, tdrops, rbytes, rpkts;
unsigned int start;
dstats = per_cpu_ptr(dev->dstats, i);
do {
start = u64_stats_fetch_begin_irq(&dstats->syncp);
tbytes = dstats->tx_bytes;
tpkts = dstats->tx_pkts;
tdrops = dstats->tx_drps;
rbytes = dstats->rx_bytes;
rpkts = dstats->rx_pkts;
} while (u64_stats_fetch_retry_irq(&dstats->syncp, start));
stats->tx_bytes += tbytes;
stats->tx_packets += tpkts;
stats->tx_dropped += tdrops;
stats->rx_bytes += rbytes;
stats->rx_packets += rpkts;
}
}
net: vrf: performance improvements for IPv4 The VRF driver allows users to implement device based features for an entire domain. For example, a qdisc or netfilter rules can be attached to a VRF device or tcpdump can be used to view packets for all devices in the L3 domain. The device-based features come with a performance penalty, most notably in the Tx path. The VRF driver uses the l3mdev_l3_out hook to switch the dst on an skb to its private dst. This allows the skb to traverse the xmit stack with the device set to the VRF device which in turn enables the netfilter and qdisc features. The VRF driver then performs the FIB lookup again and reinserts the packet. This patch avoids the redirect for IPv4 packets if a qdisc has not been attached to a VRF device which is the default config. In this case the netfilter hooks and network taps are directly traversed in the l3mdev_l3_out handler. If a qdisc is attached to a VRF device, then the redirect using the vrf dst is done. Additional overhead is removed by only checking packet taps if a socket is open on the device (vrf_dev->ptype_all list is not empty). Packet sockets bound to any device will still get a copy of the packet via the real ingress or egress interface. The end result of this change is a decrease in the overhead of VRF for the default, baseline case (ie., no netfilter rules, no packet sockets, no qdisc) to ~3% for UDP which has a lookup per packet and < 1% overhead for connected sockets that leverage early demux and avoid FIB lookups. Signed-off-by: David Ahern <dsa@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-21 02:19:44 +08:00
/* by default VRF devices do not have a qdisc and are expected
* to be created with only a single queue.
*/
static bool qdisc_tx_is_default(const struct net_device *dev)
{
struct netdev_queue *txq;
struct Qdisc *qdisc;
if (dev->num_tx_queues > 1)
return false;
txq = netdev_get_tx_queue(dev, 0);
qdisc = rcu_access_pointer(txq->qdisc);
return !qdisc->enqueue;
}
net: vrf: ipv4 support for local traffic to local addresses Add support for locally originated traffic to VRF-local addresses. If destination device for an skb is the loopback or VRF device then set its dst to a local version of the VRF cached dst_entry and call netif_rx to insert the packet onto the rx queue - similar to what is done for loopback. This patch handles IPv4 support; follow on patch handles IPv6. With this patch, ping, tcp and udp packets to a local IPv4 address are successfully routed: $ ip addr show dev eth1 4: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast master red state UP group default qlen 1000 link/ether 02:e0:f9:1c:b9:74 brd ff:ff:ff:ff:ff:ff inet 10.100.1.1/24 brd 10.100.1.255 scope global eth1 valid_lft forever preferred_lft forever inet6 2100:1::1/120 scope global valid_lft forever preferred_lft forever inet6 fe80::e0:f9ff:fe1c:b974/64 scope link valid_lft forever preferred_lft forever $ ping -c1 -I red 10.100.1.1 ping: Warning: source address might be selected on device other than red. PING 10.100.1.1 (10.100.1.1) from 10.100.1.1 red: 56(84) bytes of data. 64 bytes from 10.100.1.1: icmp_seq=1 ttl=64 time=0.057 ms This patch also enables use of IPv4 loopback address on the VRF device: $ ip addr add dev red 127.0.0.1/8 $ ping -c1 -I red 127.0.0.1 PING 127.0.0.1 (127.0.0.1) from 127.0.0.1 red: 56(84) bytes of data. 64 bytes from 127.0.0.1: icmp_seq=1 ttl=64 time=0.058 ms Signed-off-by: David Ahern <dsa@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-07 11:50:39 +08:00
/* Local traffic destined to local address. Reinsert the packet to rx
* path, similar to loopback handling.
*/
static int vrf_local_xmit(struct sk_buff *skb, struct net_device *dev,
struct dst_entry *dst)
{
int len = skb->len;
skb_orphan(skb);
skb_dst_set(skb, dst);
/* set pkt_type to avoid skb hitting packet taps twice -
* once on Tx and again in Rx processing
*/
skb->pkt_type = PACKET_LOOPBACK;
skb->protocol = eth_type_trans(skb, dev);
if (likely(netif_rx(skb) == NET_RX_SUCCESS))
vrf_rx_stats(dev, len);
else
this_cpu_inc(dev->dstats->rx_drps);
return NETDEV_TX_OK;
}
#if IS_ENABLED(CONFIG_IPV6)
static int vrf_ip6_local_out(struct net *net, struct sock *sk,
struct sk_buff *skb)
{
int err;
err = nf_hook(NFPROTO_IPV6, NF_INET_LOCAL_OUT, net,
sk, skb, NULL, skb_dst(skb)->dev, dst_output);
if (likely(err == 1))
err = dst_output(net, sk, skb);
return err;
}
static netdev_tx_t vrf_process_v6_outbound(struct sk_buff *skb,
struct net_device *dev)
{
const struct ipv6hdr *iph = ipv6_hdr(skb);
struct net *net = dev_net(skb->dev);
struct flowi6 fl6 = {
/* needed to match OIF rule */
.flowi6_oif = dev->ifindex,
.flowi6_iif = LOOPBACK_IFINDEX,
.daddr = iph->daddr,
.saddr = iph->saddr,
.flowlabel = ip6_flowinfo(iph),
.flowi6_mark = skb->mark,
.flowi6_proto = iph->nexthdr,
.flowi6_flags = FLOWI_FLAG_SKIP_NH_OIF,
};
int ret = NET_XMIT_DROP;
struct dst_entry *dst;
struct dst_entry *dst_null = &net->ipv6.ip6_null_entry->dst;
dst = ip6_route_output(net, NULL, &fl6);
if (dst == dst_null)
goto err;
skb_dst_drop(skb);
/* if dst.dev is loopback or the VRF device again this is locally
* originated traffic destined to a local address. Short circuit
* to Rx path
*/
if (dst->dev == dev)
return vrf_local_xmit(skb, dev, dst);
skb_dst_set(skb, dst);
/* strip the ethernet header added for pass through VRF device */
__skb_pull(skb, skb_network_offset(skb));
ret = vrf_ip6_local_out(net, skb->sk, skb);
if (unlikely(net_xmit_eval(ret)))
dev->stats.tx_errors++;
else
ret = NET_XMIT_SUCCESS;
return ret;
err:
vrf_tx_error(dev, skb);
return NET_XMIT_DROP;
}
#else
static netdev_tx_t vrf_process_v6_outbound(struct sk_buff *skb,
struct net_device *dev)
{
vrf_tx_error(dev, skb);
return NET_XMIT_DROP;
}
#endif
/* based on ip_local_out; can't use it b/c the dst is switched pointing to us */
static int vrf_ip_local_out(struct net *net, struct sock *sk,
struct sk_buff *skb)
{
int err;
err = nf_hook(NFPROTO_IPV4, NF_INET_LOCAL_OUT, net, sk,
skb, NULL, skb_dst(skb)->dev, dst_output);
if (likely(err == 1))
err = dst_output(net, sk, skb);
return err;
}
static netdev_tx_t vrf_process_v4_outbound(struct sk_buff *skb,
struct net_device *vrf_dev)
{
struct iphdr *ip4h = ip_hdr(skb);
int ret = NET_XMIT_DROP;
struct flowi4 fl4 = {
/* needed to match OIF rule */
.flowi4_oif = vrf_dev->ifindex,
.flowi4_iif = LOOPBACK_IFINDEX,
.flowi4_tos = RT_TOS(ip4h->tos),
.flowi4_flags = FLOWI_FLAG_ANYSRC | FLOWI_FLAG_SKIP_NH_OIF,
.flowi4_proto = ip4h->protocol,
.daddr = ip4h->daddr,
.saddr = ip4h->saddr,
};
struct net *net = dev_net(vrf_dev);
struct rtable *rt;
rt = ip_route_output_flow(net, &fl4, NULL);
if (IS_ERR(rt))
goto err;
skb_dst_drop(skb);
net: vrf: ipv4 support for local traffic to local addresses Add support for locally originated traffic to VRF-local addresses. If destination device for an skb is the loopback or VRF device then set its dst to a local version of the VRF cached dst_entry and call netif_rx to insert the packet onto the rx queue - similar to what is done for loopback. This patch handles IPv4 support; follow on patch handles IPv6. With this patch, ping, tcp and udp packets to a local IPv4 address are successfully routed: $ ip addr show dev eth1 4: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast master red state UP group default qlen 1000 link/ether 02:e0:f9:1c:b9:74 brd ff:ff:ff:ff:ff:ff inet 10.100.1.1/24 brd 10.100.1.255 scope global eth1 valid_lft forever preferred_lft forever inet6 2100:1::1/120 scope global valid_lft forever preferred_lft forever inet6 fe80::e0:f9ff:fe1c:b974/64 scope link valid_lft forever preferred_lft forever $ ping -c1 -I red 10.100.1.1 ping: Warning: source address might be selected on device other than red. PING 10.100.1.1 (10.100.1.1) from 10.100.1.1 red: 56(84) bytes of data. 64 bytes from 10.100.1.1: icmp_seq=1 ttl=64 time=0.057 ms This patch also enables use of IPv4 loopback address on the VRF device: $ ip addr add dev red 127.0.0.1/8 $ ping -c1 -I red 127.0.0.1 PING 127.0.0.1 (127.0.0.1) from 127.0.0.1 red: 56(84) bytes of data. 64 bytes from 127.0.0.1: icmp_seq=1 ttl=64 time=0.058 ms Signed-off-by: David Ahern <dsa@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-07 11:50:39 +08:00
/* if dst.dev is loopback or the VRF device again this is locally
* originated traffic destined to a local address. Short circuit
* to Rx path
net: vrf: ipv4 support for local traffic to local addresses Add support for locally originated traffic to VRF-local addresses. If destination device for an skb is the loopback or VRF device then set its dst to a local version of the VRF cached dst_entry and call netif_rx to insert the packet onto the rx queue - similar to what is done for loopback. This patch handles IPv4 support; follow on patch handles IPv6. With this patch, ping, tcp and udp packets to a local IPv4 address are successfully routed: $ ip addr show dev eth1 4: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast master red state UP group default qlen 1000 link/ether 02:e0:f9:1c:b9:74 brd ff:ff:ff:ff:ff:ff inet 10.100.1.1/24 brd 10.100.1.255 scope global eth1 valid_lft forever preferred_lft forever inet6 2100:1::1/120 scope global valid_lft forever preferred_lft forever inet6 fe80::e0:f9ff:fe1c:b974/64 scope link valid_lft forever preferred_lft forever $ ping -c1 -I red 10.100.1.1 ping: Warning: source address might be selected on device other than red. PING 10.100.1.1 (10.100.1.1) from 10.100.1.1 red: 56(84) bytes of data. 64 bytes from 10.100.1.1: icmp_seq=1 ttl=64 time=0.057 ms This patch also enables use of IPv4 loopback address on the VRF device: $ ip addr add dev red 127.0.0.1/8 $ ping -c1 -I red 127.0.0.1 PING 127.0.0.1 (127.0.0.1) from 127.0.0.1 red: 56(84) bytes of data. 64 bytes from 127.0.0.1: icmp_seq=1 ttl=64 time=0.058 ms Signed-off-by: David Ahern <dsa@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-07 11:50:39 +08:00
*/
if (rt->dst.dev == vrf_dev)
return vrf_local_xmit(skb, vrf_dev, &rt->dst);
net: vrf: ipv4 support for local traffic to local addresses Add support for locally originated traffic to VRF-local addresses. If destination device for an skb is the loopback or VRF device then set its dst to a local version of the VRF cached dst_entry and call netif_rx to insert the packet onto the rx queue - similar to what is done for loopback. This patch handles IPv4 support; follow on patch handles IPv6. With this patch, ping, tcp and udp packets to a local IPv4 address are successfully routed: $ ip addr show dev eth1 4: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast master red state UP group default qlen 1000 link/ether 02:e0:f9:1c:b9:74 brd ff:ff:ff:ff:ff:ff inet 10.100.1.1/24 brd 10.100.1.255 scope global eth1 valid_lft forever preferred_lft forever inet6 2100:1::1/120 scope global valid_lft forever preferred_lft forever inet6 fe80::e0:f9ff:fe1c:b974/64 scope link valid_lft forever preferred_lft forever $ ping -c1 -I red 10.100.1.1 ping: Warning: source address might be selected on device other than red. PING 10.100.1.1 (10.100.1.1) from 10.100.1.1 red: 56(84) bytes of data. 64 bytes from 10.100.1.1: icmp_seq=1 ttl=64 time=0.057 ms This patch also enables use of IPv4 loopback address on the VRF device: $ ip addr add dev red 127.0.0.1/8 $ ping -c1 -I red 127.0.0.1 PING 127.0.0.1 (127.0.0.1) from 127.0.0.1 red: 56(84) bytes of data. 64 bytes from 127.0.0.1: icmp_seq=1 ttl=64 time=0.058 ms Signed-off-by: David Ahern <dsa@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-07 11:50:39 +08:00
skb_dst_set(skb, &rt->dst);
/* strip the ethernet header added for pass through VRF device */
__skb_pull(skb, skb_network_offset(skb));
if (!ip4h->saddr) {
ip4h->saddr = inet_select_addr(skb_dst(skb)->dev, 0,
RT_SCOPE_LINK);
}
ret = vrf_ip_local_out(dev_net(skb_dst(skb)->dev), skb->sk, skb);
if (unlikely(net_xmit_eval(ret)))
vrf_dev->stats.tx_errors++;
else
ret = NET_XMIT_SUCCESS;
out:
return ret;
err:
vrf_tx_error(vrf_dev, skb);
goto out;
}
static netdev_tx_t is_ip_tx_frame(struct sk_buff *skb, struct net_device *dev)
{
switch (skb->protocol) {
case htons(ETH_P_IP):
return vrf_process_v4_outbound(skb, dev);
case htons(ETH_P_IPV6):
return vrf_process_v6_outbound(skb, dev);
default:
vrf_tx_error(dev, skb);
return NET_XMIT_DROP;
}
}
static netdev_tx_t vrf_xmit(struct sk_buff *skb, struct net_device *dev)
{
int len = skb->len;
netdev_tx_t ret = is_ip_tx_frame(skb, dev);
if (likely(ret == NET_XMIT_SUCCESS || ret == NET_XMIT_CN)) {
struct pcpu_dstats *dstats = this_cpu_ptr(dev->dstats);
u64_stats_update_begin(&dstats->syncp);
dstats->tx_pkts++;
dstats->tx_bytes += len;
u64_stats_update_end(&dstats->syncp);
} else {
this_cpu_inc(dev->dstats->tx_drps);
}
return ret;
}
net: vrf: performance improvements for IPv4 The VRF driver allows users to implement device based features for an entire domain. For example, a qdisc or netfilter rules can be attached to a VRF device or tcpdump can be used to view packets for all devices in the L3 domain. The device-based features come with a performance penalty, most notably in the Tx path. The VRF driver uses the l3mdev_l3_out hook to switch the dst on an skb to its private dst. This allows the skb to traverse the xmit stack with the device set to the VRF device which in turn enables the netfilter and qdisc features. The VRF driver then performs the FIB lookup again and reinserts the packet. This patch avoids the redirect for IPv4 packets if a qdisc has not been attached to a VRF device which is the default config. In this case the netfilter hooks and network taps are directly traversed in the l3mdev_l3_out handler. If a qdisc is attached to a VRF device, then the redirect using the vrf dst is done. Additional overhead is removed by only checking packet taps if a socket is open on the device (vrf_dev->ptype_all list is not empty). Packet sockets bound to any device will still get a copy of the packet via the real ingress or egress interface. The end result of this change is a decrease in the overhead of VRF for the default, baseline case (ie., no netfilter rules, no packet sockets, no qdisc) to ~3% for UDP which has a lookup per packet and < 1% overhead for connected sockets that leverage early demux and avoid FIB lookups. Signed-off-by: David Ahern <dsa@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-21 02:19:44 +08:00
static int vrf_finish_direct(struct net *net, struct sock *sk,
struct sk_buff *skb)
{
struct net_device *vrf_dev = skb->dev;
if (!list_empty(&vrf_dev->ptype_all) &&
likely(skb_headroom(skb) >= ETH_HLEN)) {
struct ethhdr *eth = skb_push(skb, ETH_HLEN);
net: vrf: performance improvements for IPv4 The VRF driver allows users to implement device based features for an entire domain. For example, a qdisc or netfilter rules can be attached to a VRF device or tcpdump can be used to view packets for all devices in the L3 domain. The device-based features come with a performance penalty, most notably in the Tx path. The VRF driver uses the l3mdev_l3_out hook to switch the dst on an skb to its private dst. This allows the skb to traverse the xmit stack with the device set to the VRF device which in turn enables the netfilter and qdisc features. The VRF driver then performs the FIB lookup again and reinserts the packet. This patch avoids the redirect for IPv4 packets if a qdisc has not been attached to a VRF device which is the default config. In this case the netfilter hooks and network taps are directly traversed in the l3mdev_l3_out handler. If a qdisc is attached to a VRF device, then the redirect using the vrf dst is done. Additional overhead is removed by only checking packet taps if a socket is open on the device (vrf_dev->ptype_all list is not empty). Packet sockets bound to any device will still get a copy of the packet via the real ingress or egress interface. The end result of this change is a decrease in the overhead of VRF for the default, baseline case (ie., no netfilter rules, no packet sockets, no qdisc) to ~3% for UDP which has a lookup per packet and < 1% overhead for connected sockets that leverage early demux and avoid FIB lookups. Signed-off-by: David Ahern <dsa@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-21 02:19:44 +08:00
ether_addr_copy(eth->h_source, vrf_dev->dev_addr);
eth_zero_addr(eth->h_dest);
eth->h_proto = skb->protocol;
rcu_read_lock_bh();
dev_queue_xmit_nit(skb, vrf_dev);
rcu_read_unlock_bh();
skb_pull(skb, ETH_HLEN);
}
return 1;
}
#if IS_ENABLED(CONFIG_IPV6)
/* modelled after ip6_finish_output2 */
static int vrf_finish_output6(struct net *net, struct sock *sk,
struct sk_buff *skb)
{
struct dst_entry *dst = skb_dst(skb);
struct net_device *dev = dst->dev;
struct neighbour *neigh;
struct in6_addr *nexthop;
int ret;
nf_reset(skb);
skb->protocol = htons(ETH_P_IPV6);
skb->dev = dev;
rcu_read_lock_bh();
nexthop = rt6_nexthop((struct rt6_info *)dst, &ipv6_hdr(skb)->daddr);
neigh = __ipv6_neigh_lookup_noref(dst->dev, nexthop);
if (unlikely(!neigh))
neigh = __neigh_create(&nd_tbl, nexthop, dst->dev, false);
if (!IS_ERR(neigh)) {
sock_confirm_neigh(skb, neigh);
ret = neigh_output(neigh, skb);
rcu_read_unlock_bh();
return ret;
}
rcu_read_unlock_bh();
IP6_INC_STATS(dev_net(dst->dev),
ip6_dst_idev(dst), IPSTATS_MIB_OUTNOROUTES);
kfree_skb(skb);
return -EINVAL;
}
/* modelled after ip6_output */
static int vrf_output6(struct net *net, struct sock *sk, struct sk_buff *skb)
{
return NF_HOOK_COND(NFPROTO_IPV6, NF_INET_POST_ROUTING,
net, sk, skb, NULL, skb_dst(skb)->dev,
vrf_finish_output6,
!(IP6CB(skb)->flags & IP6SKB_REROUTED));
}
/* set dst on skb to send packet to us via dev_xmit path. Allows
* packet to go through device based features such as qdisc, netfilter
* hooks and packet sockets with skb->dev set to vrf device.
*/
net: vrf: performance improvements for IPv6 The VRF driver allows users to implement device based features for an entire domain. For example, a qdisc or netfilter rules can be attached to a VRF device or tcpdump can be used to view packets for all devices in the L3 domain. The device-based features come with a performance penalty, most notably in the Tx path. The VRF driver uses the l3mdev_l3_out hook to switch the dst on an skb to its private dst. This allows the skb to traverse the xmit stack with the device set to the VRF device which in turn enables the netfilter and qdisc features. The VRF driver then performs the FIB lookup again and reinserts the packet. This patch avoids the redirect for IPv6 packets if a qdisc has not been attached to a VRF device which is the default config. In this case the netfilter hooks and network taps are directly traversed in the l3mdev_l3_out handler. If a qdisc is attached to a VRF device, then the redirect using the vrf dst is done. Additional overhead is removed by only checking packet taps if a socket is open on the device (vrf_dev->ptype_all list is not empty). Packet sockets bound to any device will still get a copy of the packet via the real ingress or egress interface. The end result of this change is a decrease in the overhead of VRF for the default, baseline case (ie., no netfilter rules, no packet sockets, no qdisc) from a +3% improvement for UDP which has a lookup per packet (VRF being better than no l3mdev) to ~2% loss for TCP_CRR which connects a socket for each request-response. Signed-off-by: David Ahern <dsa@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-21 02:19:45 +08:00
static struct sk_buff *vrf_ip6_out_redirect(struct net_device *vrf_dev,
struct sk_buff *skb)
{
struct net_vrf *vrf = netdev_priv(vrf_dev);
struct dst_entry *dst = NULL;
struct rt6_info *rt6;
rcu_read_lock();
rt6 = rcu_dereference(vrf->rt6);
if (likely(rt6)) {
dst = &rt6->dst;
dst_hold(dst);
}
rcu_read_unlock();
if (unlikely(!dst)) {
vrf_tx_error(vrf_dev, skb);
return NULL;
}
skb_dst_drop(skb);
skb_dst_set(skb, dst);
return skb;
}
net: vrf: performance improvements for IPv6 The VRF driver allows users to implement device based features for an entire domain. For example, a qdisc or netfilter rules can be attached to a VRF device or tcpdump can be used to view packets for all devices in the L3 domain. The device-based features come with a performance penalty, most notably in the Tx path. The VRF driver uses the l3mdev_l3_out hook to switch the dst on an skb to its private dst. This allows the skb to traverse the xmit stack with the device set to the VRF device which in turn enables the netfilter and qdisc features. The VRF driver then performs the FIB lookup again and reinserts the packet. This patch avoids the redirect for IPv6 packets if a qdisc has not been attached to a VRF device which is the default config. In this case the netfilter hooks and network taps are directly traversed in the l3mdev_l3_out handler. If a qdisc is attached to a VRF device, then the redirect using the vrf dst is done. Additional overhead is removed by only checking packet taps if a socket is open on the device (vrf_dev->ptype_all list is not empty). Packet sockets bound to any device will still get a copy of the packet via the real ingress or egress interface. The end result of this change is a decrease in the overhead of VRF for the default, baseline case (ie., no netfilter rules, no packet sockets, no qdisc) from a +3% improvement for UDP which has a lookup per packet (VRF being better than no l3mdev) to ~2% loss for TCP_CRR which connects a socket for each request-response. Signed-off-by: David Ahern <dsa@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-21 02:19:45 +08:00
static int vrf_output6_direct(struct net *net, struct sock *sk,
struct sk_buff *skb)
{
skb->protocol = htons(ETH_P_IPV6);
return NF_HOOK_COND(NFPROTO_IPV6, NF_INET_POST_ROUTING,
net, sk, skb, NULL, skb->dev,
vrf_finish_direct,
!(IPCB(skb)->flags & IPSKB_REROUTED));
}
static struct sk_buff *vrf_ip6_out_direct(struct net_device *vrf_dev,
struct sock *sk,
struct sk_buff *skb)
{
struct net *net = dev_net(vrf_dev);
int err;
skb->dev = vrf_dev;
err = nf_hook(NFPROTO_IPV6, NF_INET_LOCAL_OUT, net, sk,
skb, NULL, vrf_dev, vrf_output6_direct);
if (likely(err == 1))
err = vrf_output6_direct(net, sk, skb);
/* reset skb device */
if (likely(err == 1))
nf_reset(skb);
else
skb = NULL;
return skb;
}
static struct sk_buff *vrf_ip6_out(struct net_device *vrf_dev,
struct sock *sk,
struct sk_buff *skb)
{
/* don't divert link scope packets */
if (rt6_need_strict(&ipv6_hdr(skb)->daddr))
return skb;
if (qdisc_tx_is_default(vrf_dev))
return vrf_ip6_out_direct(vrf_dev, sk, skb);
return vrf_ip6_out_redirect(vrf_dev, skb);
}
/* holding rtnl */
static void vrf_rt6_release(struct net_device *dev, struct net_vrf *vrf)
{
struct rt6_info *rt6 = rtnl_dereference(vrf->rt6);
struct net *net = dev_net(dev);
struct dst_entry *dst;
RCU_INIT_POINTER(vrf->rt6, NULL);
synchronize_rcu();
/* move dev in dst's to loopback so this VRF device can be deleted
* - based on dst_ifdown
*/
if (rt6) {
dst = &rt6->dst;
dev_put(dst->dev);
dst->dev = net->loopback_dev;
dev_hold(dst->dev);
dst_release(dst);
}
}
static int vrf_rt6_create(struct net_device *dev)
{
int flags = DST_HOST | DST_NOPOLICY | DST_NOXFRM;
struct net_vrf *vrf = netdev_priv(dev);
struct net *net = dev_net(dev);
struct rt6_info *rt6;
int rc = -ENOMEM;
net: vrf: Fix crash when IPv6 is disabled at boot time Frank Kellermann reported a kernel crash with 4.5.0 when IPv6 is disabled at boot using the kernel option ipv6.disable=1. Using current net-next with the boot option: $ ip link add red type vrf table 1001 Generates: [12210.919584] BUG: unable to handle kernel NULL pointer dereference at 0000000000000748 [12210.921341] IP: [<ffffffff814b30e3>] fib6_get_table+0x2c/0x5a [12210.922537] PGD b79e3067 PUD bb32b067 PMD 0 [12210.923479] Oops: 0000 [#1] SMP [12210.924001] Modules linked in: ipvlan 8021q garp mrp stp llc [12210.925130] CPU: 3 PID: 1177 Comm: ip Not tainted 4.7.0-rc1+ #235 [12210.926168] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.7.5-20140531_083030-gandalf 04/01/2014 [12210.928065] task: ffff8800b9ac4640 ti: ffff8800bacac000 task.ti: ffff8800bacac000 [12210.929328] RIP: 0010:[<ffffffff814b30e3>] [<ffffffff814b30e3>] fib6_get_table+0x2c/0x5a [12210.930697] RSP: 0018:ffff8800bacaf888 EFLAGS: 00010202 [12210.931563] RAX: 0000000000000748 RBX: ffffffff81a9e280 RCX: ffff8800b9ac4e28 [12210.932688] RDX: 00000000000000e9 RSI: 0000000000000002 RDI: 0000000000000286 [12210.933820] RBP: ffff8800bacaf898 R08: ffff8800b9ac4df0 R09: 000000000052001b [12210.934941] R10: 00000000657c0000 R11: 000000000000c649 R12: 00000000000003e9 [12210.936032] R13: 00000000000003e9 R14: ffff8800bace7800 R15: ffff8800bb3ec000 [12210.937103] FS: 00007faa1766c700(0000) GS:ffff88013ac00000(0000) knlGS:0000000000000000 [12210.938321] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [12210.939166] CR2: 0000000000000748 CR3: 00000000b79d6000 CR4: 00000000000406e0 [12210.940278] Stack: [12210.940603] ffff8800bb3ec000 ffffffff81a9e280 ffff8800bacaf8c8 ffffffff814b3135 [12210.941818] ffff8800bb3ec000 ffffffff81a9e280 ffffffff81a9e280 ffff8800bace7800 [12210.943040] ffff8800bacaf8f0 ffffffff81397c88 ffff8800bb3ec000 ffffffff81a9e280 [12210.944288] Call Trace: [12210.944688] [<ffffffff814b3135>] fib6_new_table+0x24/0x8a [12210.945516] [<ffffffff81397c88>] vrf_dev_init+0xd4/0x162 [12210.946328] [<ffffffff814091e1>] register_netdevice+0x100/0x396 [12210.947209] [<ffffffff8139823d>] vrf_newlink+0x40/0xb3 [12210.948001] [<ffffffff814187f0>] rtnl_newlink+0x5d3/0x6d5 ... The problem above is due to the fact that the fib hash table is not allocated when IPv6 is disabled at boot. As for the VRF driver it should not do any IPv6 initializations if IPv6 is disabled, so it needs to know if IPv6 is disabled at boot. The disable parameter is private to the IPv6 module, so provide an accessor for modules to determine if IPv6 was disabled at boot time. Fixes: 35402e3136634 ("net: Add IPv6 support to VRF device") Signed-off-by: David Ahern <dsa@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-10 01:21:00 +08:00
/* IPv6 can be CONFIG enabled and then disabled runtime */
if (!ipv6_mod_enabled())
return 0;
vrf->fib6_table = fib6_new_table(net, vrf->tb_id);
if (!vrf->fib6_table)
goto out;
/* create a dst for routing packets out a VRF device */
rt6 = ip6_dst_alloc(net, dev, flags);
if (!rt6)
goto out;
rt6->dst.output = vrf_output6;
rcu_assign_pointer(vrf->rt6, rt6);
rc = 0;
out:
return rc;
}
#else
static struct sk_buff *vrf_ip6_out(struct net_device *vrf_dev,
struct sock *sk,
struct sk_buff *skb)
{
return skb;
}
static void vrf_rt6_release(struct net_device *dev, struct net_vrf *vrf)
{
}
static int vrf_rt6_create(struct net_device *dev)
{
return 0;
}
#endif
/* modelled after ip_finish_output2 */
static int vrf_finish_output(struct net *net, struct sock *sk, struct sk_buff *skb)
{
struct dst_entry *dst = skb_dst(skb);
struct rtable *rt = (struct rtable *)dst;
struct net_device *dev = dst->dev;
unsigned int hh_len = LL_RESERVED_SPACE(dev);
struct neighbour *neigh;
u32 nexthop;
int ret = -EINVAL;
nf_reset(skb);
/* Be paranoid, rather than too clever. */
if (unlikely(skb_headroom(skb) < hh_len && dev->header_ops)) {
struct sk_buff *skb2;
skb2 = skb_realloc_headroom(skb, LL_RESERVED_SPACE(dev));
if (!skb2) {
ret = -ENOMEM;
goto err;
}
if (skb->sk)
skb_set_owner_w(skb2, skb->sk);
consume_skb(skb);
skb = skb2;
}
rcu_read_lock_bh();
nexthop = (__force u32)rt_nexthop(rt, ip_hdr(skb)->daddr);
neigh = __ipv4_neigh_lookup_noref(dev, nexthop);
if (unlikely(!neigh))
neigh = __neigh_create(&arp_tbl, &nexthop, dev, false);
if (!IS_ERR(neigh)) {
sock_confirm_neigh(skb, neigh);
ret = neigh_output(neigh, skb);
rcu_read_unlock_bh();
return ret;
}
rcu_read_unlock_bh();
err:
vrf_tx_error(skb->dev, skb);
return ret;
}
static int vrf_output(struct net *net, struct sock *sk, struct sk_buff *skb)
{
struct net_device *dev = skb_dst(skb)->dev;
2015-09-16 09:04:16 +08:00
IP_UPD_PO_STATS(net, IPSTATS_MIB_OUT, skb->len);
skb->dev = dev;
skb->protocol = htons(ETH_P_IP);
2015-09-16 09:04:16 +08:00
return NF_HOOK_COND(NFPROTO_IPV4, NF_INET_POST_ROUTING,
net, sk, skb, NULL, dev,
vrf_finish_output,
!(IPCB(skb)->flags & IPSKB_REROUTED));
}
/* set dst on skb to send packet to us via dev_xmit path. Allows
* packet to go through device based features such as qdisc, netfilter
* hooks and packet sockets with skb->dev set to vrf device.
*/
net: vrf: performance improvements for IPv4 The VRF driver allows users to implement device based features for an entire domain. For example, a qdisc or netfilter rules can be attached to a VRF device or tcpdump can be used to view packets for all devices in the L3 domain. The device-based features come with a performance penalty, most notably in the Tx path. The VRF driver uses the l3mdev_l3_out hook to switch the dst on an skb to its private dst. This allows the skb to traverse the xmit stack with the device set to the VRF device which in turn enables the netfilter and qdisc features. The VRF driver then performs the FIB lookup again and reinserts the packet. This patch avoids the redirect for IPv4 packets if a qdisc has not been attached to a VRF device which is the default config. In this case the netfilter hooks and network taps are directly traversed in the l3mdev_l3_out handler. If a qdisc is attached to a VRF device, then the redirect using the vrf dst is done. Additional overhead is removed by only checking packet taps if a socket is open on the device (vrf_dev->ptype_all list is not empty). Packet sockets bound to any device will still get a copy of the packet via the real ingress or egress interface. The end result of this change is a decrease in the overhead of VRF for the default, baseline case (ie., no netfilter rules, no packet sockets, no qdisc) to ~3% for UDP which has a lookup per packet and < 1% overhead for connected sockets that leverage early demux and avoid FIB lookups. Signed-off-by: David Ahern <dsa@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-21 02:19:44 +08:00
static struct sk_buff *vrf_ip_out_redirect(struct net_device *vrf_dev,
struct sk_buff *skb)
{
struct net_vrf *vrf = netdev_priv(vrf_dev);
struct dst_entry *dst = NULL;
struct rtable *rth;
rcu_read_lock();
rth = rcu_dereference(vrf->rth);
if (likely(rth)) {
dst = &rth->dst;
dst_hold(dst);
}
rcu_read_unlock();
if (unlikely(!dst)) {
vrf_tx_error(vrf_dev, skb);
return NULL;
}
skb_dst_drop(skb);
skb_dst_set(skb, dst);
return skb;
}
net: vrf: performance improvements for IPv4 The VRF driver allows users to implement device based features for an entire domain. For example, a qdisc or netfilter rules can be attached to a VRF device or tcpdump can be used to view packets for all devices in the L3 domain. The device-based features come with a performance penalty, most notably in the Tx path. The VRF driver uses the l3mdev_l3_out hook to switch the dst on an skb to its private dst. This allows the skb to traverse the xmit stack with the device set to the VRF device which in turn enables the netfilter and qdisc features. The VRF driver then performs the FIB lookup again and reinserts the packet. This patch avoids the redirect for IPv4 packets if a qdisc has not been attached to a VRF device which is the default config. In this case the netfilter hooks and network taps are directly traversed in the l3mdev_l3_out handler. If a qdisc is attached to a VRF device, then the redirect using the vrf dst is done. Additional overhead is removed by only checking packet taps if a socket is open on the device (vrf_dev->ptype_all list is not empty). Packet sockets bound to any device will still get a copy of the packet via the real ingress or egress interface. The end result of this change is a decrease in the overhead of VRF for the default, baseline case (ie., no netfilter rules, no packet sockets, no qdisc) to ~3% for UDP which has a lookup per packet and < 1% overhead for connected sockets that leverage early demux and avoid FIB lookups. Signed-off-by: David Ahern <dsa@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-21 02:19:44 +08:00
static int vrf_output_direct(struct net *net, struct sock *sk,
struct sk_buff *skb)
{
skb->protocol = htons(ETH_P_IP);
return NF_HOOK_COND(NFPROTO_IPV4, NF_INET_POST_ROUTING,
net, sk, skb, NULL, skb->dev,
vrf_finish_direct,
!(IPCB(skb)->flags & IPSKB_REROUTED));
}
static struct sk_buff *vrf_ip_out_direct(struct net_device *vrf_dev,
struct sock *sk,
struct sk_buff *skb)
{
struct net *net = dev_net(vrf_dev);
int err;
skb->dev = vrf_dev;
err = nf_hook(NFPROTO_IPV4, NF_INET_LOCAL_OUT, net, sk,
skb, NULL, vrf_dev, vrf_output_direct);
if (likely(err == 1))
err = vrf_output_direct(net, sk, skb);
/* reset skb device */
if (likely(err == 1))
nf_reset(skb);
else
skb = NULL;
return skb;
}
static struct sk_buff *vrf_ip_out(struct net_device *vrf_dev,
struct sock *sk,
struct sk_buff *skb)
{
/* don't divert multicast or local broadcast */
if (ipv4_is_multicast(ip_hdr(skb)->daddr) ||
ipv4_is_lbcast(ip_hdr(skb)->daddr))
net: vrf: performance improvements for IPv4 The VRF driver allows users to implement device based features for an entire domain. For example, a qdisc or netfilter rules can be attached to a VRF device or tcpdump can be used to view packets for all devices in the L3 domain. The device-based features come with a performance penalty, most notably in the Tx path. The VRF driver uses the l3mdev_l3_out hook to switch the dst on an skb to its private dst. This allows the skb to traverse the xmit stack with the device set to the VRF device which in turn enables the netfilter and qdisc features. The VRF driver then performs the FIB lookup again and reinserts the packet. This patch avoids the redirect for IPv4 packets if a qdisc has not been attached to a VRF device which is the default config. In this case the netfilter hooks and network taps are directly traversed in the l3mdev_l3_out handler. If a qdisc is attached to a VRF device, then the redirect using the vrf dst is done. Additional overhead is removed by only checking packet taps if a socket is open on the device (vrf_dev->ptype_all list is not empty). Packet sockets bound to any device will still get a copy of the packet via the real ingress or egress interface. The end result of this change is a decrease in the overhead of VRF for the default, baseline case (ie., no netfilter rules, no packet sockets, no qdisc) to ~3% for UDP which has a lookup per packet and < 1% overhead for connected sockets that leverage early demux and avoid FIB lookups. Signed-off-by: David Ahern <dsa@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-21 02:19:44 +08:00
return skb;
if (qdisc_tx_is_default(vrf_dev))
return vrf_ip_out_direct(vrf_dev, sk, skb);
return vrf_ip_out_redirect(vrf_dev, skb);
}
/* called with rcu lock held */
static struct sk_buff *vrf_l3_out(struct net_device *vrf_dev,
struct sock *sk,
struct sk_buff *skb,
u16 proto)
{
switch (proto) {
case AF_INET:
return vrf_ip_out(vrf_dev, sk, skb);
case AF_INET6:
return vrf_ip6_out(vrf_dev, sk, skb);
}
return skb;
}
/* holding rtnl */
static void vrf_rtable_release(struct net_device *dev, struct net_vrf *vrf)
{
struct rtable *rth = rtnl_dereference(vrf->rth);
struct net *net = dev_net(dev);
struct dst_entry *dst;
net: vrf: ipv4 support for local traffic to local addresses Add support for locally originated traffic to VRF-local addresses. If destination device for an skb is the loopback or VRF device then set its dst to a local version of the VRF cached dst_entry and call netif_rx to insert the packet onto the rx queue - similar to what is done for loopback. This patch handles IPv4 support; follow on patch handles IPv6. With this patch, ping, tcp and udp packets to a local IPv4 address are successfully routed: $ ip addr show dev eth1 4: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast master red state UP group default qlen 1000 link/ether 02:e0:f9:1c:b9:74 brd ff:ff:ff:ff:ff:ff inet 10.100.1.1/24 brd 10.100.1.255 scope global eth1 valid_lft forever preferred_lft forever inet6 2100:1::1/120 scope global valid_lft forever preferred_lft forever inet6 fe80::e0:f9ff:fe1c:b974/64 scope link valid_lft forever preferred_lft forever $ ping -c1 -I red 10.100.1.1 ping: Warning: source address might be selected on device other than red. PING 10.100.1.1 (10.100.1.1) from 10.100.1.1 red: 56(84) bytes of data. 64 bytes from 10.100.1.1: icmp_seq=1 ttl=64 time=0.057 ms This patch also enables use of IPv4 loopback address on the VRF device: $ ip addr add dev red 127.0.0.1/8 $ ping -c1 -I red 127.0.0.1 PING 127.0.0.1 (127.0.0.1) from 127.0.0.1 red: 56(84) bytes of data. 64 bytes from 127.0.0.1: icmp_seq=1 ttl=64 time=0.058 ms Signed-off-by: David Ahern <dsa@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-07 11:50:39 +08:00
RCU_INIT_POINTER(vrf->rth, NULL);
synchronize_rcu();
/* move dev in dst's to loopback so this VRF device can be deleted
* - based on dst_ifdown
*/
if (rth) {
dst = &rth->dst;
dev_put(dst->dev);
dst->dev = net->loopback_dev;
dev_hold(dst->dev);
dst_release(dst);
}
}
static int vrf_rtable_create(struct net_device *dev)
{
struct net_vrf *vrf = netdev_priv(dev);
struct rtable *rth;
if (!fib_new_table(dev_net(dev), vrf->tb_id))
return -ENOMEM;
net: vrf: ipv4 support for local traffic to local addresses Add support for locally originated traffic to VRF-local addresses. If destination device for an skb is the loopback or VRF device then set its dst to a local version of the VRF cached dst_entry and call netif_rx to insert the packet onto the rx queue - similar to what is done for loopback. This patch handles IPv4 support; follow on patch handles IPv6. With this patch, ping, tcp and udp packets to a local IPv4 address are successfully routed: $ ip addr show dev eth1 4: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast master red state UP group default qlen 1000 link/ether 02:e0:f9:1c:b9:74 brd ff:ff:ff:ff:ff:ff inet 10.100.1.1/24 brd 10.100.1.255 scope global eth1 valid_lft forever preferred_lft forever inet6 2100:1::1/120 scope global valid_lft forever preferred_lft forever inet6 fe80::e0:f9ff:fe1c:b974/64 scope link valid_lft forever preferred_lft forever $ ping -c1 -I red 10.100.1.1 ping: Warning: source address might be selected on device other than red. PING 10.100.1.1 (10.100.1.1) from 10.100.1.1 red: 56(84) bytes of data. 64 bytes from 10.100.1.1: icmp_seq=1 ttl=64 time=0.057 ms This patch also enables use of IPv4 loopback address on the VRF device: $ ip addr add dev red 127.0.0.1/8 $ ping -c1 -I red 127.0.0.1 PING 127.0.0.1 (127.0.0.1) from 127.0.0.1 red: 56(84) bytes of data. 64 bytes from 127.0.0.1: icmp_seq=1 ttl=64 time=0.058 ms Signed-off-by: David Ahern <dsa@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-07 11:50:39 +08:00
/* create a dst for routing packets out through a VRF device */
rth = rt_dst_alloc(dev, 0, RTN_UNICAST, 1, 1, 0);
if (!rth)
return -ENOMEM;
rth->dst.output = vrf_output;
rcu_assign_pointer(vrf->rth, rth);
return 0;
}
/**************************** device handling ********************/
/* cycle interface to flush neighbor cache and move routes across tables */
static void cycle_netdev(struct net_device *dev)
{
unsigned int flags = dev->flags;
int ret;
if (!netif_running(dev))
return;
ret = dev_change_flags(dev, flags & ~IFF_UP);
if (ret >= 0)
ret = dev_change_flags(dev, flags);
if (ret < 0) {
netdev_err(dev,
"Failed to cycle device %s; route tables might be wrong!\n",
dev->name);
}
}
static int do_vrf_add_slave(struct net_device *dev, struct net_device *port_dev,
struct netlink_ext_ack *extack)
{
int ret;
/* do not allow loopback device to be enslaved to a VRF.
* The vrf device acts as the loopback for the vrf.
*/
if (port_dev == dev_net(dev)->loopback_dev) {
NL_SET_ERR_MSG(extack,
"Can not enslave loopback device to a VRF");
return -EOPNOTSUPP;
}
port_dev->priv_flags |= IFF_L3MDEV_SLAVE;
ret = netdev_master_upper_dev_link(port_dev, dev, NULL, NULL, extack);
if (ret < 0)
goto err;
cycle_netdev(port_dev);
return 0;
err:
port_dev->priv_flags &= ~IFF_L3MDEV_SLAVE;
return ret;
}
static int vrf_add_slave(struct net_device *dev, struct net_device *port_dev,
struct netlink_ext_ack *extack)
{
if (netif_is_l3_master(port_dev)) {
NL_SET_ERR_MSG(extack,
"Can not enslave an L3 master device to a VRF");
return -EINVAL;
}
if (netif_is_l3_slave(port_dev))
return -EINVAL;
return do_vrf_add_slave(dev, port_dev, extack);
}
/* inverse of do_vrf_add_slave */
static int do_vrf_del_slave(struct net_device *dev, struct net_device *port_dev)
{
netdev_upper_dev_unlink(port_dev, dev);
port_dev->priv_flags &= ~IFF_L3MDEV_SLAVE;
cycle_netdev(port_dev);
return 0;
}
static int vrf_del_slave(struct net_device *dev, struct net_device *port_dev)
{
return do_vrf_del_slave(dev, port_dev);
}
static void vrf_dev_uninit(struct net_device *dev)
{
struct net_vrf *vrf = netdev_priv(dev);
vrf_rtable_release(dev, vrf);
vrf_rt6_release(dev, vrf);
free_percpu(dev->dstats);
dev->dstats = NULL;
}
static int vrf_dev_init(struct net_device *dev)
{
struct net_vrf *vrf = netdev_priv(dev);
dev->dstats = netdev_alloc_pcpu_stats(struct pcpu_dstats);
if (!dev->dstats)
goto out_nomem;
/* create the default dst which points back to us */
if (vrf_rtable_create(dev) != 0)
goto out_stats;
if (vrf_rt6_create(dev) != 0)
goto out_rth;
dev->flags = IFF_MASTER | IFF_NOARP;
/* MTU is irrelevant for VRF device; set to 64k similar to lo */
dev->mtu = 64 * 1024;
/* similarly, oper state is irrelevant; set to up to avoid confusion */
dev->operstate = IF_OPER_UP;
netdev_lockdep_set_classes(dev);
return 0;
out_rth:
vrf_rtable_release(dev, vrf);
out_stats:
free_percpu(dev->dstats);
dev->dstats = NULL;
out_nomem:
return -ENOMEM;
}
static const struct net_device_ops vrf_netdev_ops = {
.ndo_init = vrf_dev_init,
.ndo_uninit = vrf_dev_uninit,
.ndo_start_xmit = vrf_xmit,
.ndo_get_stats64 = vrf_get_stats64,
.ndo_add_slave = vrf_add_slave,
.ndo_del_slave = vrf_del_slave,
};
static u32 vrf_fib_table(const struct net_device *dev)
{
struct net_vrf *vrf = netdev_priv(dev);
return vrf->tb_id;
}
static int vrf_rcv_finish(struct net *net, struct sock *sk, struct sk_buff *skb)
{
kfree_skb(skb);
return 0;
}
static struct sk_buff *vrf_rcv_nfhook(u8 pf, unsigned int hook,
struct sk_buff *skb,
struct net_device *dev)
{
struct net *net = dev_net(dev);
if (nf_hook(pf, hook, net, NULL, skb, dev, NULL, vrf_rcv_finish) != 1)
skb = NULL; /* kfree_skb(skb) handled by nf code */
return skb;
}
#if IS_ENABLED(CONFIG_IPV6)
/* neighbor handling is done with actual device; do not want
* to flip skb->dev for those ndisc packets. This really fails
* for multiple next protocols (e.g., NEXTHDR_HOP). But it is
* a start.
*/
static bool ipv6_ndisc_frame(const struct sk_buff *skb)
{
const struct ipv6hdr *iph = ipv6_hdr(skb);
bool rc = false;
if (iph->nexthdr == NEXTHDR_ICMP) {
const struct icmp6hdr *icmph;
struct icmp6hdr _icmph;
icmph = skb_header_pointer(skb, sizeof(*iph),
sizeof(_icmph), &_icmph);
if (!icmph)
goto out;
switch (icmph->icmp6_type) {
case NDISC_ROUTER_SOLICITATION:
case NDISC_ROUTER_ADVERTISEMENT:
case NDISC_NEIGHBOUR_SOLICITATION:
case NDISC_NEIGHBOUR_ADVERTISEMENT:
case NDISC_REDIRECT:
rc = true;
break;
}
}
out:
return rc;
}
static struct rt6_info *vrf_ip6_route_lookup(struct net *net,
const struct net_device *dev,
struct flowi6 *fl6,
int ifindex,
const struct sk_buff *skb,
int flags)
{
struct net_vrf *vrf = netdev_priv(dev);
return ip6_pol_route(net, vrf->fib6_table, ifindex, fl6, skb, flags);
}
static void vrf_ip6_input_dst(struct sk_buff *skb, struct net_device *vrf_dev,
int ifindex)
{
const struct ipv6hdr *iph = ipv6_hdr(skb);
struct flowi6 fl6 = {
.flowi6_iif = ifindex,
.flowi6_mark = skb->mark,
.flowi6_proto = iph->nexthdr,
.daddr = iph->daddr,
.saddr = iph->saddr,
.flowlabel = ip6_flowinfo(iph),
};
struct net *net = dev_net(vrf_dev);
struct rt6_info *rt6;
rt6 = vrf_ip6_route_lookup(net, vrf_dev, &fl6, ifindex, skb,
RT6_LOOKUP_F_HAS_SADDR | RT6_LOOKUP_F_IFACE);
if (unlikely(!rt6))
return;
if (unlikely(&rt6->dst == &net->ipv6.ip6_null_entry->dst))
return;
skb_dst_set(skb, &rt6->dst);
}
static struct sk_buff *vrf_ip6_rcv(struct net_device *vrf_dev,
struct sk_buff *skb)
{
int orig_iif = skb->skb_iif;
bool need_strict = rt6_need_strict(&ipv6_hdr(skb)->daddr);
bool is_ndisc = ipv6_ndisc_frame(skb);
/* loopback, multicast & non-ND link-local traffic; do not push through
* packet taps again. Reset pkt_type for upper layers to process skb
*/
if (skb->pkt_type == PACKET_LOOPBACK || (need_strict && !is_ndisc)) {
skb->dev = vrf_dev;
skb->skb_iif = vrf_dev->ifindex;
net: Require exact match for TCP socket lookups if dif is l3mdev Currently, socket lookups for l3mdev (vrf) use cases can match a socket that is bound to a port but not a device (ie., a global socket). If the sysctl tcp_l3mdev_accept is not set this leads to ack packets going out based on the main table even though the packet came in from an L3 domain. The end result is that the connection does not establish creating confusion for users since the service is running and a socket shows in ss output. Fix by requiring an exact dif to sk_bound_dev_if match if the skb came through an interface enslaved to an l3mdev device and the tcp_l3mdev_accept is not set. skb's through an l3mdev interface are marked by setting a flag in inet{6}_skb_parm. The IPv6 variant is already set; this patch adds the flag for IPv4. Using an skb flag avoids a device lookup on the dif. The flag is set in the VRF driver using the IP{6}CB macros. For IPv4, the inet_skb_parm struct is moved in the cb per commit 971f10eca186, so the match function in the TCP stack needs to use TCP_SKB_CB. For IPv6, the move is done after the socket lookup, so IP6CB is used. The flags field in inet_skb_parm struct needs to be increased to add another flag. There is currently a 1-byte hole following the flags, so it can be expanded to u16 without increasing the size of the struct. Fixes: 193125dbd8eb ("net: Introduce VRF device driver") Signed-off-by: David Ahern <dsa@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-10-17 11:02:52 +08:00
IP6CB(skb)->flags |= IP6SKB_L3SLAVE;
if (skb->pkt_type == PACKET_LOOPBACK)
skb->pkt_type = PACKET_HOST;
goto out;
}
/* if packet is NDISC then keep the ingress interface */
if (!is_ndisc) {
vrf_rx_stats(vrf_dev, skb->len);
skb->dev = vrf_dev;
skb->skb_iif = vrf_dev->ifindex;
net: vrf: performance improvements for IPv6 The VRF driver allows users to implement device based features for an entire domain. For example, a qdisc or netfilter rules can be attached to a VRF device or tcpdump can be used to view packets for all devices in the L3 domain. The device-based features come with a performance penalty, most notably in the Tx path. The VRF driver uses the l3mdev_l3_out hook to switch the dst on an skb to its private dst. This allows the skb to traverse the xmit stack with the device set to the VRF device which in turn enables the netfilter and qdisc features. The VRF driver then performs the FIB lookup again and reinserts the packet. This patch avoids the redirect for IPv6 packets if a qdisc has not been attached to a VRF device which is the default config. In this case the netfilter hooks and network taps are directly traversed in the l3mdev_l3_out handler. If a qdisc is attached to a VRF device, then the redirect using the vrf dst is done. Additional overhead is removed by only checking packet taps if a socket is open on the device (vrf_dev->ptype_all list is not empty). Packet sockets bound to any device will still get a copy of the packet via the real ingress or egress interface. The end result of this change is a decrease in the overhead of VRF for the default, baseline case (ie., no netfilter rules, no packet sockets, no qdisc) from a +3% improvement for UDP which has a lookup per packet (VRF being better than no l3mdev) to ~2% loss for TCP_CRR which connects a socket for each request-response. Signed-off-by: David Ahern <dsa@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-21 02:19:45 +08:00
if (!list_empty(&vrf_dev->ptype_all)) {
skb_push(skb, skb->mac_len);
dev_queue_xmit_nit(skb, vrf_dev);
skb_pull(skb, skb->mac_len);
}
IP6CB(skb)->flags |= IP6SKB_L3SLAVE;
}
if (need_strict)
vrf_ip6_input_dst(skb, vrf_dev, orig_iif);
skb = vrf_rcv_nfhook(NFPROTO_IPV6, NF_INET_PRE_ROUTING, skb, vrf_dev);
out:
return skb;
}
#else
static struct sk_buff *vrf_ip6_rcv(struct net_device *vrf_dev,
struct sk_buff *skb)
{
return skb;
}
#endif
static struct sk_buff *vrf_ip_rcv(struct net_device *vrf_dev,
struct sk_buff *skb)
{
skb->dev = vrf_dev;
skb->skb_iif = vrf_dev->ifindex;
net: Require exact match for TCP socket lookups if dif is l3mdev Currently, socket lookups for l3mdev (vrf) use cases can match a socket that is bound to a port but not a device (ie., a global socket). If the sysctl tcp_l3mdev_accept is not set this leads to ack packets going out based on the main table even though the packet came in from an L3 domain. The end result is that the connection does not establish creating confusion for users since the service is running and a socket shows in ss output. Fix by requiring an exact dif to sk_bound_dev_if match if the skb came through an interface enslaved to an l3mdev device and the tcp_l3mdev_accept is not set. skb's through an l3mdev interface are marked by setting a flag in inet{6}_skb_parm. The IPv6 variant is already set; this patch adds the flag for IPv4. Using an skb flag avoids a device lookup on the dif. The flag is set in the VRF driver using the IP{6}CB macros. For IPv4, the inet_skb_parm struct is moved in the cb per commit 971f10eca186, so the match function in the TCP stack needs to use TCP_SKB_CB. For IPv6, the move is done after the socket lookup, so IP6CB is used. The flags field in inet_skb_parm struct needs to be increased to add another flag. There is currently a 1-byte hole following the flags, so it can be expanded to u16 without increasing the size of the struct. Fixes: 193125dbd8eb ("net: Introduce VRF device driver") Signed-off-by: David Ahern <dsa@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-10-17 11:02:52 +08:00
IPCB(skb)->flags |= IPSKB_L3SLAVE;
if (ipv4_is_multicast(ip_hdr(skb)->daddr))
goto out;
net: vrf: ipv4 support for local traffic to local addresses Add support for locally originated traffic to VRF-local addresses. If destination device for an skb is the loopback or VRF device then set its dst to a local version of the VRF cached dst_entry and call netif_rx to insert the packet onto the rx queue - similar to what is done for loopback. This patch handles IPv4 support; follow on patch handles IPv6. With this patch, ping, tcp and udp packets to a local IPv4 address are successfully routed: $ ip addr show dev eth1 4: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast master red state UP group default qlen 1000 link/ether 02:e0:f9:1c:b9:74 brd ff:ff:ff:ff:ff:ff inet 10.100.1.1/24 brd 10.100.1.255 scope global eth1 valid_lft forever preferred_lft forever inet6 2100:1::1/120 scope global valid_lft forever preferred_lft forever inet6 fe80::e0:f9ff:fe1c:b974/64 scope link valid_lft forever preferred_lft forever $ ping -c1 -I red 10.100.1.1 ping: Warning: source address might be selected on device other than red. PING 10.100.1.1 (10.100.1.1) from 10.100.1.1 red: 56(84) bytes of data. 64 bytes from 10.100.1.1: icmp_seq=1 ttl=64 time=0.057 ms This patch also enables use of IPv4 loopback address on the VRF device: $ ip addr add dev red 127.0.0.1/8 $ ping -c1 -I red 127.0.0.1 PING 127.0.0.1 (127.0.0.1) from 127.0.0.1 red: 56(84) bytes of data. 64 bytes from 127.0.0.1: icmp_seq=1 ttl=64 time=0.058 ms Signed-off-by: David Ahern <dsa@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-07 11:50:39 +08:00
/* loopback traffic; do not push through packet taps again.
* Reset pkt_type for upper layers to process skb
*/
if (skb->pkt_type == PACKET_LOOPBACK) {
skb->pkt_type = PACKET_HOST;
goto out;
}
vrf_rx_stats(vrf_dev, skb->len);
net: vrf: performance improvements for IPv4 The VRF driver allows users to implement device based features for an entire domain. For example, a qdisc or netfilter rules can be attached to a VRF device or tcpdump can be used to view packets for all devices in the L3 domain. The device-based features come with a performance penalty, most notably in the Tx path. The VRF driver uses the l3mdev_l3_out hook to switch the dst on an skb to its private dst. This allows the skb to traverse the xmit stack with the device set to the VRF device which in turn enables the netfilter and qdisc features. The VRF driver then performs the FIB lookup again and reinserts the packet. This patch avoids the redirect for IPv4 packets if a qdisc has not been attached to a VRF device which is the default config. In this case the netfilter hooks and network taps are directly traversed in the l3mdev_l3_out handler. If a qdisc is attached to a VRF device, then the redirect using the vrf dst is done. Additional overhead is removed by only checking packet taps if a socket is open on the device (vrf_dev->ptype_all list is not empty). Packet sockets bound to any device will still get a copy of the packet via the real ingress or egress interface. The end result of this change is a decrease in the overhead of VRF for the default, baseline case (ie., no netfilter rules, no packet sockets, no qdisc) to ~3% for UDP which has a lookup per packet and < 1% overhead for connected sockets that leverage early demux and avoid FIB lookups. Signed-off-by: David Ahern <dsa@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-21 02:19:44 +08:00
if (!list_empty(&vrf_dev->ptype_all)) {
skb_push(skb, skb->mac_len);
dev_queue_xmit_nit(skb, vrf_dev);
skb_pull(skb, skb->mac_len);
}
skb = vrf_rcv_nfhook(NFPROTO_IPV4, NF_INET_PRE_ROUTING, skb, vrf_dev);
net: vrf: ipv4 support for local traffic to local addresses Add support for locally originated traffic to VRF-local addresses. If destination device for an skb is the loopback or VRF device then set its dst to a local version of the VRF cached dst_entry and call netif_rx to insert the packet onto the rx queue - similar to what is done for loopback. This patch handles IPv4 support; follow on patch handles IPv6. With this patch, ping, tcp and udp packets to a local IPv4 address are successfully routed: $ ip addr show dev eth1 4: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast master red state UP group default qlen 1000 link/ether 02:e0:f9:1c:b9:74 brd ff:ff:ff:ff:ff:ff inet 10.100.1.1/24 brd 10.100.1.255 scope global eth1 valid_lft forever preferred_lft forever inet6 2100:1::1/120 scope global valid_lft forever preferred_lft forever inet6 fe80::e0:f9ff:fe1c:b974/64 scope link valid_lft forever preferred_lft forever $ ping -c1 -I red 10.100.1.1 ping: Warning: source address might be selected on device other than red. PING 10.100.1.1 (10.100.1.1) from 10.100.1.1 red: 56(84) bytes of data. 64 bytes from 10.100.1.1: icmp_seq=1 ttl=64 time=0.057 ms This patch also enables use of IPv4 loopback address on the VRF device: $ ip addr add dev red 127.0.0.1/8 $ ping -c1 -I red 127.0.0.1 PING 127.0.0.1 (127.0.0.1) from 127.0.0.1 red: 56(84) bytes of data. 64 bytes from 127.0.0.1: icmp_seq=1 ttl=64 time=0.058 ms Signed-off-by: David Ahern <dsa@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-07 11:50:39 +08:00
out:
return skb;
}
/* called with rcu lock held */
static struct sk_buff *vrf_l3_rcv(struct net_device *vrf_dev,
struct sk_buff *skb,
u16 proto)
{
switch (proto) {
case AF_INET:
return vrf_ip_rcv(vrf_dev, skb);
case AF_INET6:
return vrf_ip6_rcv(vrf_dev, skb);
}
return skb;
}
#if IS_ENABLED(CONFIG_IPV6)
/* send to link-local or multicast address via interface enslaved to
* VRF device. Force lookup to VRF table without changing flow struct
*/
static struct dst_entry *vrf_link_scope_lookup(const struct net_device *dev,
struct flowi6 *fl6)
{
struct net *net = dev_net(dev);
int flags = RT6_LOOKUP_F_IFACE;
struct dst_entry *dst = NULL;
struct rt6_info *rt;
/* VRF device does not have a link-local address and
* sending packets to link-local or mcast addresses over
* a VRF device does not make sense
*/
if (fl6->flowi6_oif == dev->ifindex) {
dst = &net->ipv6.ip6_null_entry->dst;
dst_hold(dst);
return dst;
}
if (!ipv6_addr_any(&fl6->saddr))
flags |= RT6_LOOKUP_F_HAS_SADDR;
rt = vrf_ip6_route_lookup(net, dev, fl6, fl6->flowi6_oif, NULL, flags);
if (rt)
dst = &rt->dst;
return dst;
}
#endif
static const struct l3mdev_ops vrf_l3mdev_ops = {
.l3mdev_fib_table = vrf_fib_table,
.l3mdev_l3_rcv = vrf_l3_rcv,
.l3mdev_l3_out = vrf_l3_out,
#if IS_ENABLED(CONFIG_IPV6)
.l3mdev_link_scope_lookup = vrf_link_scope_lookup,
#endif
};
static void vrf_get_drvinfo(struct net_device *dev,
struct ethtool_drvinfo *info)
{
strlcpy(info->driver, DRV_NAME, sizeof(info->driver));
strlcpy(info->version, DRV_VERSION, sizeof(info->version));
}
static const struct ethtool_ops vrf_ethtool_ops = {
.get_drvinfo = vrf_get_drvinfo,
};
static inline size_t vrf_fib_rule_nl_size(void)
{
size_t sz;
sz = NLMSG_ALIGN(sizeof(struct fib_rule_hdr));
sz += nla_total_size(sizeof(u8)); /* FRA_L3MDEV */
sz += nla_total_size(sizeof(u32)); /* FRA_PRIORITY */
sz += nla_total_size(sizeof(u8)); /* FRA_PROTOCOL */
return sz;
}
static int vrf_fib_rule(const struct net_device *dev, __u8 family, bool add_it)
{
struct fib_rule_hdr *frh;
struct nlmsghdr *nlh;
struct sk_buff *skb;
int err;
net: vrf: Fix crash when IPv6 is disabled at boot time Frank Kellermann reported a kernel crash with 4.5.0 when IPv6 is disabled at boot using the kernel option ipv6.disable=1. Using current net-next with the boot option: $ ip link add red type vrf table 1001 Generates: [12210.919584] BUG: unable to handle kernel NULL pointer dereference at 0000000000000748 [12210.921341] IP: [<ffffffff814b30e3>] fib6_get_table+0x2c/0x5a [12210.922537] PGD b79e3067 PUD bb32b067 PMD 0 [12210.923479] Oops: 0000 [#1] SMP [12210.924001] Modules linked in: ipvlan 8021q garp mrp stp llc [12210.925130] CPU: 3 PID: 1177 Comm: ip Not tainted 4.7.0-rc1+ #235 [12210.926168] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.7.5-20140531_083030-gandalf 04/01/2014 [12210.928065] task: ffff8800b9ac4640 ti: ffff8800bacac000 task.ti: ffff8800bacac000 [12210.929328] RIP: 0010:[<ffffffff814b30e3>] [<ffffffff814b30e3>] fib6_get_table+0x2c/0x5a [12210.930697] RSP: 0018:ffff8800bacaf888 EFLAGS: 00010202 [12210.931563] RAX: 0000000000000748 RBX: ffffffff81a9e280 RCX: ffff8800b9ac4e28 [12210.932688] RDX: 00000000000000e9 RSI: 0000000000000002 RDI: 0000000000000286 [12210.933820] RBP: ffff8800bacaf898 R08: ffff8800b9ac4df0 R09: 000000000052001b [12210.934941] R10: 00000000657c0000 R11: 000000000000c649 R12: 00000000000003e9 [12210.936032] R13: 00000000000003e9 R14: ffff8800bace7800 R15: ffff8800bb3ec000 [12210.937103] FS: 00007faa1766c700(0000) GS:ffff88013ac00000(0000) knlGS:0000000000000000 [12210.938321] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [12210.939166] CR2: 0000000000000748 CR3: 00000000b79d6000 CR4: 00000000000406e0 [12210.940278] Stack: [12210.940603] ffff8800bb3ec000 ffffffff81a9e280 ffff8800bacaf8c8 ffffffff814b3135 [12210.941818] ffff8800bb3ec000 ffffffff81a9e280 ffffffff81a9e280 ffff8800bace7800 [12210.943040] ffff8800bacaf8f0 ffffffff81397c88 ffff8800bb3ec000 ffffffff81a9e280 [12210.944288] Call Trace: [12210.944688] [<ffffffff814b3135>] fib6_new_table+0x24/0x8a [12210.945516] [<ffffffff81397c88>] vrf_dev_init+0xd4/0x162 [12210.946328] [<ffffffff814091e1>] register_netdevice+0x100/0x396 [12210.947209] [<ffffffff8139823d>] vrf_newlink+0x40/0xb3 [12210.948001] [<ffffffff814187f0>] rtnl_newlink+0x5d3/0x6d5 ... The problem above is due to the fact that the fib hash table is not allocated when IPv6 is disabled at boot. As for the VRF driver it should not do any IPv6 initializations if IPv6 is disabled, so it needs to know if IPv6 is disabled at boot. The disable parameter is private to the IPv6 module, so provide an accessor for modules to determine if IPv6 was disabled at boot time. Fixes: 35402e3136634 ("net: Add IPv6 support to VRF device") Signed-off-by: David Ahern <dsa@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-10 01:21:00 +08:00
if (family == AF_INET6 && !ipv6_mod_enabled())
return 0;
skb = nlmsg_new(vrf_fib_rule_nl_size(), GFP_KERNEL);
if (!skb)
return -ENOMEM;
nlh = nlmsg_put(skb, 0, 0, 0, sizeof(*frh), 0);
if (!nlh)
goto nla_put_failure;
/* rule only needs to appear once */
nlh->nlmsg_flags |= NLM_F_EXCL;
frh = nlmsg_data(nlh);
memset(frh, 0, sizeof(*frh));
frh->family = family;
frh->action = FR_ACT_TO_TBL;
if (nla_put_u8(skb, FRA_PROTOCOL, RTPROT_KERNEL))
goto nla_put_failure;
if (nla_put_u8(skb, FRA_L3MDEV, 1))
goto nla_put_failure;
if (nla_put_u32(skb, FRA_PRIORITY, FIB_RULE_PREF))
goto nla_put_failure;
nlmsg_end(skb, nlh);
/* fib_nl_{new,del}rule handling looks for net from skb->sk */
skb->sk = dev_net(dev)->rtnl;
if (add_it) {
err = fib_nl_newrule(skb, nlh, NULL);
if (err == -EEXIST)
err = 0;
} else {
err = fib_nl_delrule(skb, nlh, NULL);
if (err == -ENOENT)
err = 0;
}
nlmsg_free(skb);
return err;
nla_put_failure:
nlmsg_free(skb);
return -EMSGSIZE;
}
static int vrf_add_fib_rules(const struct net_device *dev)
{
int err;
err = vrf_fib_rule(dev, AF_INET, true);
if (err < 0)
goto out_err;
err = vrf_fib_rule(dev, AF_INET6, true);
if (err < 0)
goto ipv6_err;
#if IS_ENABLED(CONFIG_IP_MROUTE_MULTIPLE_TABLES)
err = vrf_fib_rule(dev, RTNL_FAMILY_IPMR, true);
if (err < 0)
goto ipmr_err;
#endif
#if IS_ENABLED(CONFIG_IPV6_MROUTE_MULTIPLE_TABLES)
err = vrf_fib_rule(dev, RTNL_FAMILY_IP6MR, true);
if (err < 0)
goto ip6mr_err;
#endif
return 0;
#if IS_ENABLED(CONFIG_IPV6_MROUTE_MULTIPLE_TABLES)
ip6mr_err:
vrf_fib_rule(dev, RTNL_FAMILY_IPMR, false);
#endif
#if IS_ENABLED(CONFIG_IP_MROUTE_MULTIPLE_TABLES)
ipmr_err:
vrf_fib_rule(dev, AF_INET6, false);
#endif
ipv6_err:
vrf_fib_rule(dev, AF_INET, false);
out_err:
netdev_err(dev, "Failed to add FIB rules.\n");
return err;
}
static void vrf_setup(struct net_device *dev)
{
ether_setup(dev);
/* Initialize the device structure. */
dev->netdev_ops = &vrf_netdev_ops;
dev->l3mdev_ops = &vrf_l3mdev_ops;
dev->ethtool_ops = &vrf_ethtool_ops;
net: Fix inconsistent teardown and release of private netdev state. Network devices can allocate reasources and private memory using netdev_ops->ndo_init(). However, the release of these resources can occur in one of two different places. Either netdev_ops->ndo_uninit() or netdev->destructor(). The decision of which operation frees the resources depends upon whether it is necessary for all netdev refs to be released before it is safe to perform the freeing. netdev_ops->ndo_uninit() presumably can occur right after the NETDEV_UNREGISTER notifier completes and the unicast and multicast address lists are flushed. netdev->destructor(), on the other hand, does not run until the netdev references all go away. Further complicating the situation is that netdev->destructor() almost universally does also a free_netdev(). This creates a problem for the logic in register_netdevice(). Because all callers of register_netdevice() manage the freeing of the netdev, and invoke free_netdev(dev) if register_netdevice() fails. If netdev_ops->ndo_init() succeeds, but something else fails inside of register_netdevice(), it does call ndo_ops->ndo_uninit(). But it is not able to invoke netdev->destructor(). This is because netdev->destructor() will do a free_netdev() and then the caller of register_netdevice() will do the same. However, this means that the resources that would normally be released by netdev->destructor() will not be. Over the years drivers have added local hacks to deal with this, by invoking their destructor parts by hand when register_netdevice() fails. Many drivers do not try to deal with this, and instead we have leaks. Let's close this hole by formalizing the distinction between what private things need to be freed up by netdev->destructor() and whether the driver needs unregister_netdevice() to perform the free_netdev(). netdev->priv_destructor() performs all actions to free up the private resources that used to be freed by netdev->destructor(), except for free_netdev(). netdev->needs_free_netdev is a boolean that indicates whether free_netdev() should be done at the end of unregister_netdevice(). Now, register_netdevice() can sanely release all resources after ndo_ops->ndo_init() succeeds, by invoking both ndo_ops->ndo_uninit() and netdev->priv_destructor(). And at the end of unregister_netdevice(), we invoke netdev->priv_destructor() and optionally call free_netdev(). Signed-off-by: David S. Miller <davem@davemloft.net>
2017-05-09 00:52:56 +08:00
dev->needs_free_netdev = true;
/* Fill in device structure with ethernet-generic values. */
eth_hw_addr_random(dev);
/* don't acquire vrf device's netif_tx_lock when transmitting */
dev->features |= NETIF_F_LLTX;
/* don't allow vrf devices to change network namespaces. */
dev->features |= NETIF_F_NETNS_LOCAL;
/* does not make sense for a VLAN to be added to a vrf device */
dev->features |= NETIF_F_VLAN_CHALLENGED;
/* enable offload features */
dev->features |= NETIF_F_GSO_SOFTWARE;
dev->features |= NETIF_F_RXCSUM | NETIF_F_HW_CSUM | NETIF_F_SCTP_CRC;
dev->features |= NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HIGHDMA;
dev->hw_features = dev->features;
dev->hw_enc_features = dev->features;
/* default to no qdisc; user can add if desired */
dev->priv_flags |= IFF_NO_QUEUE;
}
static int vrf_validate(struct nlattr *tb[], struct nlattr *data[],
struct netlink_ext_ack *extack)
{
if (tb[IFLA_ADDRESS]) {
if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN) {
NL_SET_ERR_MSG(extack, "Invalid hardware address");
return -EINVAL;
}
if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS]))) {
NL_SET_ERR_MSG(extack, "Invalid hardware address");
return -EADDRNOTAVAIL;
}
}
return 0;
}
static void vrf_dellink(struct net_device *dev, struct list_head *head)
{
vrf: fix bug_on triggered by rx when destroying a vrf When destroying a VRF device we cleanup the slaves in its ndo_uninit() function, but that causes packets to be switched (skb->dev == vrf being destroyed) even though we're pass the point where the VRF should be receiving any packets while it is being dismantled. This causes a BUG_ON to trigger if we have raw sockets (trace below). The reason is that the inetdev of the VRF has been destroyed but we're still sending packets up the stack with it, so let's free the slaves in the dellink callback as David Ahern suggested. Note that this fix doesn't prevent packets from going up when the VRF device is admin down. [ 35.631371] ------------[ cut here ]------------ [ 35.631603] kernel BUG at net/ipv4/fib_frontend.c:285! [ 35.631854] invalid opcode: 0000 [#1] SMP [ 35.631977] Modules linked in: [ 35.632081] CPU: 2 PID: 22 Comm: ksoftirqd/2 Not tainted 4.12.0-rc7+ #45 [ 35.632247] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.7.5-20140531_083030-gandalf 04/01/2014 [ 35.632477] task: ffff88005ad68000 task.stack: ffff88005ad64000 [ 35.632632] RIP: 0010:fib_compute_spec_dst+0xfc/0x1ee [ 35.632769] RSP: 0018:ffff88005ad67978 EFLAGS: 00010202 [ 35.632910] RAX: 0000000000000001 RBX: ffff880059a7f200 RCX: 0000000000000000 [ 35.633084] RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffffffff82274af0 [ 35.633256] RBP: ffff88005ad679f8 R08: 000000000001ef70 R09: 0000000000000046 [ 35.633430] R10: ffff88005ad679f8 R11: ffff880037731cb0 R12: 0000000000000001 [ 35.633603] R13: ffff8800599e3000 R14: 0000000000000000 R15: ffff8800599cb852 [ 35.634114] FS: 0000000000000000(0000) GS:ffff88005d900000(0000) knlGS:0000000000000000 [ 35.634306] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 35.634456] CR2: 00007f3563227095 CR3: 000000000201d000 CR4: 00000000000406e0 [ 35.634632] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 35.634865] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 35.635055] Call Trace: [ 35.635271] ? __lock_acquire+0xf0d/0x1117 [ 35.635522] ipv4_pktinfo_prepare+0x82/0x151 [ 35.635831] raw_rcv_skb+0x17/0x3c [ 35.636062] raw_rcv+0xe5/0xf7 [ 35.636287] raw_local_deliver+0x169/0x1d9 [ 35.636534] ip_local_deliver_finish+0x87/0x1c4 [ 35.636820] ip_local_deliver+0x63/0x7f [ 35.637058] ip_rcv_finish+0x340/0x3a1 [ 35.637295] ip_rcv+0x314/0x34a [ 35.637525] __netif_receive_skb_core+0x49f/0x7c5 [ 35.637780] ? lock_acquire+0x13f/0x1d7 [ 35.638018] ? lock_acquire+0x15e/0x1d7 [ 35.638259] __netif_receive_skb+0x1e/0x94 [ 35.638502] ? __netif_receive_skb+0x1e/0x94 [ 35.638748] netif_receive_skb_internal+0x74/0x300 [ 35.639002] ? dev_gro_receive+0x2ed/0x411 [ 35.639246] ? lock_is_held_type+0xc4/0xd2 [ 35.639491] napi_gro_receive+0x105/0x1a0 [ 35.639736] receive_buf+0xc32/0xc74 [ 35.639965] ? detach_buf+0x67/0x153 [ 35.640201] ? virtqueue_get_buf_ctx+0x120/0x176 [ 35.640453] virtnet_poll+0x128/0x1c5 [ 35.640690] net_rx_action+0x103/0x343 [ 35.640932] __do_softirq+0x1c7/0x4b7 [ 35.641171] run_ksoftirqd+0x23/0x5c [ 35.641403] smpboot_thread_fn+0x24f/0x26d [ 35.641646] ? sort_range+0x22/0x22 [ 35.641878] kthread+0x129/0x131 [ 35.642104] ? __list_add+0x31/0x31 [ 35.642335] ? __list_add+0x31/0x31 [ 35.642568] ret_from_fork+0x2a/0x40 [ 35.642804] Code: 05 bd 87 a3 00 01 e8 1f ef 98 ff 4d 85 f6 48 c7 c7 f0 4a 27 82 41 0f 94 c4 31 c9 31 d2 41 0f b6 f4 e8 04 71 a1 ff 45 84 e4 74 02 <0f> 0b 0f b7 93 c4 00 00 00 4d 8b a5 80 05 00 00 48 03 93 d0 00 [ 35.644342] RIP: fib_compute_spec_dst+0xfc/0x1ee RSP: ffff88005ad67978 Fixes: 193125dbd8eb ("net: Introduce VRF device driver") Reported-by: Chris Cormier <chriscormier@cumulusnetworks.com> Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Acked-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-07-06 20:24:40 +08:00
struct net_device *port_dev;
struct list_head *iter;
netdev_for_each_lower_dev(dev, port_dev, iter)
vrf_del_slave(dev, port_dev);
unregister_netdevice_queue(dev, head);
}
static int vrf_newlink(struct net *src_net, struct net_device *dev,
struct nlattr *tb[], struct nlattr *data[],
struct netlink_ext_ack *extack)
{
struct net_vrf *vrf = netdev_priv(dev);
bool *add_fib_rules;
struct net *net;
int err;
if (!data || !data[IFLA_VRF_TABLE]) {
NL_SET_ERR_MSG(extack, "VRF table id is missing");
return -EINVAL;
}
vrf->tb_id = nla_get_u32(data[IFLA_VRF_TABLE]);
if (vrf->tb_id == RT_TABLE_UNSPEC) {
NL_SET_ERR_MSG_ATTR(extack, data[IFLA_VRF_TABLE],
"Invalid VRF table id");
return -EINVAL;
}
dev->priv_flags |= IFF_L3MDEV_MASTER;
err = register_netdevice(dev);
if (err)
goto out;
net = dev_net(dev);
add_fib_rules = net_generic(net, vrf_net_id);
if (*add_fib_rules) {
err = vrf_add_fib_rules(dev);
if (err) {
unregister_netdevice(dev);
goto out;
}
*add_fib_rules = false;
}
out:
return err;
}
static size_t vrf_nl_getsize(const struct net_device *dev)
{
return nla_total_size(sizeof(u32)); /* IFLA_VRF_TABLE */
}
static int vrf_fillinfo(struct sk_buff *skb,
const struct net_device *dev)
{
struct net_vrf *vrf = netdev_priv(dev);
return nla_put_u32(skb, IFLA_VRF_TABLE, vrf->tb_id);
}
static size_t vrf_get_slave_size(const struct net_device *bond_dev,
const struct net_device *slave_dev)
{
return nla_total_size(sizeof(u32)); /* IFLA_VRF_PORT_TABLE */
}
static int vrf_fill_slave_info(struct sk_buff *skb,
const struct net_device *vrf_dev,
const struct net_device *slave_dev)
{
struct net_vrf *vrf = netdev_priv(vrf_dev);
if (nla_put_u32(skb, IFLA_VRF_PORT_TABLE, vrf->tb_id))
return -EMSGSIZE;
return 0;
}
static const struct nla_policy vrf_nl_policy[IFLA_VRF_MAX + 1] = {
[IFLA_VRF_TABLE] = { .type = NLA_U32 },
};
static struct rtnl_link_ops vrf_link_ops __read_mostly = {
.kind = DRV_NAME,
.priv_size = sizeof(struct net_vrf),
.get_size = vrf_nl_getsize,
.policy = vrf_nl_policy,
.validate = vrf_validate,
.fill_info = vrf_fillinfo,
.get_slave_size = vrf_get_slave_size,
.fill_slave_info = vrf_fill_slave_info,
.newlink = vrf_newlink,
.dellink = vrf_dellink,
.setup = vrf_setup,
.maxtype = IFLA_VRF_MAX,
};
static int vrf_device_event(struct notifier_block *unused,
unsigned long event, void *ptr)
{
struct net_device *dev = netdev_notifier_info_to_dev(ptr);
/* only care about unregister events to drop slave references */
if (event == NETDEV_UNREGISTER) {
struct net_device *vrf_dev;
if (!netif_is_l3_slave(dev))
goto out;
vrf_dev = netdev_master_upper_dev_get(dev);
vrf_del_slave(vrf_dev, dev);
}
out:
return NOTIFY_DONE;
}
static struct notifier_block vrf_notifier_block __read_mostly = {
.notifier_call = vrf_device_event,
};
/* Initialize per network namespace state */
static int __net_init vrf_netns_init(struct net *net)
{
bool *add_fib_rules = net_generic(net, vrf_net_id);
*add_fib_rules = true;
return 0;
}
static struct pernet_operations vrf_net_ops __net_initdata = {
.init = vrf_netns_init,
.id = &vrf_net_id,
.size = sizeof(bool),
};
static int __init vrf_init_module(void)
{
int rc;
register_netdevice_notifier(&vrf_notifier_block);
rc = register_pernet_subsys(&vrf_net_ops);
if (rc < 0)
goto error;
rc = rtnl_link_register(&vrf_link_ops);
if (rc < 0) {
unregister_pernet_subsys(&vrf_net_ops);
goto error;
}
return 0;
error:
unregister_netdevice_notifier(&vrf_notifier_block);
return rc;
}
module_init(vrf_init_module);
MODULE_AUTHOR("Shrijeet Mukherjee, David Ahern");
MODULE_DESCRIPTION("Device driver to instantiate VRF domains");
MODULE_LICENSE("GPL");
MODULE_ALIAS_RTNL_LINK(DRV_NAME);
MODULE_VERSION(DRV_VERSION);