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a04a480d43
linux/drivers/net/vrf.c
David Ahern a04a480d43 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 971f10eca1, 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: 193125dbd8 ("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 10:17:05 -04:00

1354 lines
31 KiB
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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>
#define DRV_NAME "vrf"
#define DRV_VERSION "1.0"
#define FIB_RULE_PREF 1000 /* default preference for FIB rules */
static bool add_fib_rules = true;
struct net_vrf {
struct rtable __rcu *rth;
struct rtable __rcu *rth_local;
struct rt6_info __rcu *rt6;
struct rt6_info __rcu *rt6_local;
u32 tb_id;
};
struct pcpu_dstats {
u64 tx_pkts;
u64 tx_bytes;
u64 tx_drps;
u64 rx_pkts;
u64 rx_bytes;
u64 rx_drps;
struct u64_stats_sync syncp;
};
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 struct rtnl_link_stats64 *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;
}
return stats;
}
/* 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);
skb_dst_force(skb);
/* 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 using our local dst
*/
if (dst->dev == net->loopback_dev || dst->dev == dev) {
struct net_vrf *vrf = netdev_priv(dev);
struct rt6_info *rt6_local;
/* release looked up dst and use cached local dst */
dst_release(dst);
rcu_read_lock();
rt6_local = rcu_dereference(vrf->rt6_local);
if (unlikely(!rt6_local)) {
rcu_read_unlock();
goto err;
}
/* Ordering issue: cached local dst is created on newlink
* before the IPv6 initialization. Using the local dst
* requires rt6i_idev to be set so make sure it is.
*/
if (unlikely(!rt6_local->rt6i_idev)) {
rt6_local->rt6i_idev = in6_dev_get(dev);
if (!rt6_local->rt6i_idev) {
rcu_read_unlock();
goto err;
}
}
dst = &rt6_local->dst;
dst_hold(dst);
rcu_read_unlock();
return vrf_local_xmit(skb, dev, &rt6_local->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,
.daddr = ip4h->daddr,
};
struct net *net = dev_net(vrf_dev);
struct rtable *rt;
rt = ip_route_output_flow(net, &fl4, NULL);
if (IS_ERR(rt))
goto err;
if (rt->rt_type != RTN_UNICAST && rt->rt_type != RTN_LOCAL) {
ip_rt_put(rt);
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 using our local dst
*/
if (rt->dst.dev == net->loopback_dev || rt->dst.dev == vrf_dev) {
struct net_vrf *vrf = netdev_priv(vrf_dev);
struct rtable *rth_local;
struct dst_entry *dst = NULL;
ip_rt_put(rt);
rcu_read_lock();
rth_local = rcu_dereference(vrf->rth_local);
if (likely(rth_local)) {
dst = &rth_local->dst;
dst_hold(dst);
}
rcu_read_unlock();
if (unlikely(!dst))
goto err;
return vrf_local_xmit(skb, vrf_dev, dst);
}
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)
{
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 += skb->len;
u64_stats_update_end(&dstats->syncp);
} else {
this_cpu_inc(dev->dstats->tx_drps);
}
return ret;
}
#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;
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)) {
ret = dst_neigh_output(dst, 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.
*/
static struct sk_buff *vrf_ip6_out(struct net_device *vrf_dev,
struct sock *sk,
struct sk_buff *skb)
{
struct net_vrf *vrf = netdev_priv(vrf_dev);
struct dst_entry *dst = NULL;
struct rt6_info *rt6;
/* don't divert link scope packets */
if (rt6_need_strict(&ipv6_hdr(skb)->daddr))
return skb;
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;
}
/* holding rtnl */
static void vrf_rt6_release(struct net_device *dev, struct net_vrf *vrf)
{
struct rt6_info *rt6 = rtnl_dereference(vrf->rt6);
struct rt6_info *rt6_local = rtnl_dereference(vrf->rt6_local);
struct net *net = dev_net(dev);
struct dst_entry *dst;
RCU_INIT_POINTER(vrf->rt6, NULL);
RCU_INIT_POINTER(vrf->rt6_local, 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);
}
if (rt6_local) {
if (rt6_local->rt6i_idev)
in6_dev_put(rt6_local->rt6i_idev);
dst = &rt6_local->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 | DST_NOCACHE;
struct net_vrf *vrf = netdev_priv(dev);
struct net *net = dev_net(dev);
struct fib6_table *rt6i_table;
struct rt6_info *rt6, *rt6_local;
int rc = -ENOMEM;
/* IPv6 can be CONFIG enabled and then disabled runtime */
if (!ipv6_mod_enabled())
return 0;
rt6i_table = fib6_new_table(net, vrf->tb_id);
if (!rt6i_table)
goto out;
/* create a dst for routing packets out a VRF device */
rt6 = ip6_dst_alloc(net, dev, flags);
if (!rt6)
goto out;
dst_hold(&rt6->dst);
rt6->rt6i_table = rt6i_table;
rt6->dst.output = vrf_output6;
/* create a dst for local routing - packets sent locally
* to local address via the VRF device as a loopback
*/
rt6_local = ip6_dst_alloc(net, dev, flags);
if (!rt6_local) {
dst_release(&rt6->dst);
goto out;
}
dst_hold(&rt6_local->dst);
rt6_local->rt6i_idev = in6_dev_get(dev);
rt6_local->rt6i_flags = RTF_UP | RTF_NONEXTHOP | RTF_LOCAL;
rt6_local->rt6i_table = rt6i_table;
rt6_local->dst.input = ip6_input;
rcu_assign_pointer(vrf->rt6, rt6);
rcu_assign_pointer(vrf->rt6_local, rt6_local);
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;
/* 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))
ret = dst_neigh_output(dst, neigh, skb);
rcu_read_unlock_bh();
err:
if (unlikely(ret < 0))
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;
IP_UPD_PO_STATS(net, IPSTATS_MIB_OUT, skb->len);
skb->dev = dev;
skb->protocol = htons(ETH_P_IP);
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.
*/
static struct sk_buff *vrf_ip_out(struct net_device *vrf_dev,
struct sock *sk,
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;
}
/* 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 rtable *rth_local = rtnl_dereference(vrf->rth_local);
struct net *net = dev_net(dev);
struct dst_entry *dst;
RCU_INIT_POINTER(vrf->rth, NULL);
RCU_INIT_POINTER(vrf->rth_local, 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);
}
if (rth_local) {
dst = &rth_local->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, *rth_local;
if (!fib_new_table(dev_net(dev), vrf->tb_id))
return -ENOMEM;
/* 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;
/* create a dst for local ingress routing - packets sent locally
* to local address via the VRF device as a loopback
*/
rth_local = rt_dst_alloc(dev, RTCF_LOCAL, RTN_LOCAL, 1, 1, 0);
if (!rth_local) {
dst_release(&rth->dst);
return -ENOMEM;
}
rth->dst.output = vrf_output;
rth->rt_table_id = vrf->tb_id;
rth_local->rt_table_id = vrf->tb_id;
rcu_assign_pointer(vrf->rth, rth);
rcu_assign_pointer(vrf->rth_local, rth_local);
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)
{
int ret;
ret = netdev_master_upper_dev_link(port_dev, dev, NULL, NULL);
if (ret < 0)
return ret;
port_dev->priv_flags |= IFF_L3MDEV_SLAVE;
cycle_netdev(port_dev);
return 0;
}
static int vrf_add_slave(struct net_device *dev, struct net_device *port_dev)
{
if (netif_is_l3_master(port_dev) || netif_is_l3_slave(port_dev))
return -EINVAL;
return do_vrf_add_slave(dev, port_dev);
}
/* 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);
struct net_device *port_dev;
struct list_head *iter;
vrf_rtable_release(dev, vrf);
vrf_rt6_release(dev, vrf);
netdev_for_each_lower_dev(dev, port_dev, iter)
vrf_del_slave(dev, port_dev);
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)
{
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);
nf_reset(skb);
if (NF_HOOK(pf, hook, net, NULL, skb, dev, NULL, vrf_rcv_finish) < 0)
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,
int flags)
{
struct net_vrf *vrf = netdev_priv(dev);
struct fib6_table *table = NULL;
struct rt6_info *rt6;
rcu_read_lock();
/* fib6_table does not have a refcnt and can not be freed */
rt6 = rcu_dereference(vrf->rt6);
if (likely(rt6))
table = rt6->rt6i_table;
rcu_read_unlock();
if (!table)
return NULL;
return ip6_pol_route(net, table, ifindex, fl6, 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 = {
.daddr = iph->daddr,
.saddr = iph->saddr,
.flowlabel = ip6_flowinfo(iph),
.flowi6_mark = skb->mark,
.flowi6_proto = iph->nexthdr,
.flowi6_iif = ifindex,
};
struct net *net = dev_net(vrf_dev);
struct rt6_info *rt6;
rt6 = vrf_ip6_route_lookup(net, vrf_dev, &fl6, ifindex,
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;
/* 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->dev = vrf_dev;
skb->skb_iif = vrf_dev->ifindex;
IP6CB(skb)->flags |= IP6SKB_L3SLAVE;
skb->pkt_type = PACKET_HOST;
goto out;
}
/* if packet is NDISC or addressed to multicast or link-local
* then keep the ingress interface
*/
need_strict = rt6_need_strict(&ipv6_hdr(skb)->daddr);
if (!ipv6_ndisc_frame(skb) && !need_strict) {
skb->dev = vrf_dev;
skb->skb_iif = vrf_dev->ifindex;
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;
IPCB(skb)->flags |= IPSKB_L3SLAVE;
/* 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;
}
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);
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, 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 */
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;
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_u32(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);
if (err == -EEXIST)
err = 0;
} else {
err = fib_nl_delrule(skb, nlh);
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;
return 0;
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;
dev->destructor = free_netdev;
/* 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;
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[])
{
if (tb[IFLA_ADDRESS]) {
if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
return -EINVAL;
if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
return -EADDRNOTAVAIL;
}
return 0;
}
static void vrf_dellink(struct net_device *dev, struct list_head *head)
{
unregister_netdevice_queue(dev, head);
}
static int vrf_newlink(struct net *src_net, struct net_device *dev,
struct nlattr *tb[], struct nlattr *data[])
{
struct net_vrf *vrf = netdev_priv(dev);
int err;
if (!data || !data[IFLA_VRF_TABLE])
return -EINVAL;
vrf->tb_id = nla_get_u32(data[IFLA_VRF_TABLE]);
dev->priv_flags |= IFF_L3MDEV_MASTER;
err = register_netdevice(dev);
if (err)
goto out;
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,
};
static int __init vrf_init_module(void)
{
int rc;
register_netdevice_notifier(&vrf_notifier_block);
rc = rtnl_link_register(&vrf_link_ops);
if (rc < 0)
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);
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