linux/drivers/net/vrf.c
Nikolay Aleksandrov 7f109f7cc3 vrf: fix double free and memory corruption on register_netdevice failure
When vrf's ->newlink is called, if register_netdevice() fails then it
does free_netdev(), but that's also done by rtnl_newlink() so a second
free happens and memory gets corrupted, to reproduce execute the
following line a couple of times (1 - 5 usually is enough):
$ for i in `seq 1 5`; do ip link add vrf: type vrf table 1; done;
This works because we fail in register_netdevice() because of the wrong
name "vrf:".

And here's a trace of one crash:
[   28.792157] ------------[ cut here ]------------
[   28.792407] kernel BUG at fs/namei.c:246!
[   28.792608] invalid opcode: 0000 [#1] SMP
[   28.793240] Modules linked in: vrf nfsd auth_rpcgss oid_registry
nfs_acl nfs lockd grace sunrpc crct10dif_pclmul crc32_pclmul
crc32c_intel qxl drm_kms_helper ttm drm aesni_intel aes_x86_64 psmouse
glue_helper lrw evdev gf128mul i2c_piix4 ablk_helper cryptd ppdev
parport_pc parport serio_raw pcspkr virtio_balloon virtio_console
i2c_core acpi_cpufreq button 9pnet_virtio 9p 9pnet fscache ipv6 autofs4
ext4 crc16 mbcache jbd2 virtio_blk virtio_net sg sr_mod cdrom
ata_generic ehci_pci uhci_hcd ehci_hcd e1000 usbcore usb_common ata_piix
libata virtio_pci virtio_ring virtio scsi_mod floppy
[   28.796016] CPU: 0 PID: 1148 Comm: ld-linux-x86-64 Not tainted
4.4.0-rc1+ #24
[   28.796016] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996),
BIOS 1.8.1-20150318_183358- 04/01/2014
[   28.796016] task: ffff8800352561c0 ti: ffff88003592c000 task.ti:
ffff88003592c000
[   28.796016] RIP: 0010:[<ffffffff812187b3>]  [<ffffffff812187b3>]
putname+0x43/0x60
[   28.796016] RSP: 0018:ffff88003592fe88  EFLAGS: 00010246
[   28.796016] RAX: 0000000000000000 RBX: ffff8800352561c0 RCX:
0000000000000001
[   28.796016] RDX: 0000000000000000 RSI: 0000000000000000 RDI:
ffff88003784f000
[   28.796016] RBP: ffff88003592ff08 R08: 0000000000000001 R09:
0000000000000000
[   28.796016] R10: 0000000000000000 R11: 0000000000000001 R12:
0000000000000000
[   28.796016] R13: 000000000000047c R14: ffff88003784f000 R15:
ffff8800358c4a00
[   28.796016] FS:  0000000000000000(0000) GS:ffff88003fc00000(0000)
knlGS:0000000000000000
[   28.796016] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   28.796016] CR2: 00007ffd583bc2d9 CR3: 0000000035a99000 CR4:
00000000000406f0
[   28.796016] Stack:
[   28.796016]  ffffffff8121045d ffffffff812102d3 ffff8800352561c0
ffff880035a91660
[   28.796016]  ffff8800008a9880 0000000000000000 ffffffff81a49940
00ffffff81218684
[   28.796016]  ffff8800352561c0 000000000000047c 0000000000000000
ffff880035b36d80
[   28.796016] Call Trace:
[   28.796016]  [<ffffffff8121045d>] ?
do_execveat_common.isra.34+0x74d/0x930
[   28.796016]  [<ffffffff812102d3>] ?
do_execveat_common.isra.34+0x5c3/0x930
[   28.796016]  [<ffffffff8121066c>] do_execve+0x2c/0x30
[   28.796016]  [<ffffffff810939a0>]
call_usermodehelper_exec_async+0xf0/0x140
[   28.796016]  [<ffffffff810938b0>] ? umh_complete+0x40/0x40
[   28.796016]  [<ffffffff815cb1af>] ret_from_fork+0x3f/0x70
[   28.796016] Code: 48 8d 47 1c 48 89 e5 53 48 8b 37 48 89 fb 48 39 c6
74 1a 48 8b 3d 7e e9 8f 00 e8 49 fa fc ff 48 89 df e8 f1 01 fd ff 5b 5d
f3 c3 <0f> 0b 48 89 fe 48 8b 3d 61 e9 8f 00 e8 2c fa fc ff 5b 5d eb e9
[   28.796016] RIP  [<ffffffff812187b3>] putname+0x43/0x60
[   28.796016]  RSP <ffff88003592fe88>

Fixes: 193125dbd8 ("net: Introduce VRF device driver")
Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Acked-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-11-23 17:52:46 -05:00

1024 lines
23 KiB
C

/*
* 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/rtnetlink.h>
#include <net/route.h>
#include <net/addrconf.h>
#include <net/l3mdev.h>
#define RT_FL_TOS(oldflp4) \
((oldflp4)->flowi4_tos & (IPTOS_RT_MASK | RTO_ONLINK))
#define DRV_NAME "vrf"
#define DRV_VERSION "1.0"
#define vrf_master_get_rcu(dev) \
((struct net_device *)rcu_dereference(dev->rx_handler_data))
struct slave {
struct list_head list;
struct net_device *dev;
};
struct slave_queue {
struct list_head all_slaves;
};
struct net_vrf {
struct slave_queue queue;
struct rtable *rth;
struct rt6_info *rt6;
u32 tb_id;
};
struct pcpu_dstats {
u64 tx_pkts;
u64 tx_bytes;
u64 tx_drps;
u64 rx_pkts;
u64 rx_bytes;
struct u64_stats_sync syncp;
};
static struct dst_entry *vrf_ip_check(struct dst_entry *dst, u32 cookie)
{
return dst;
}
static int vrf_ip_local_out(struct net *net, struct sock *sk, struct sk_buff *skb)
{
return ip_local_out(net, sk, skb);
}
static unsigned int vrf_v4_mtu(const struct dst_entry *dst)
{
/* TO-DO: return max ethernet size? */
return dst->dev->mtu;
}
static void vrf_dst_destroy(struct dst_entry *dst)
{
/* our dst lives forever - or until the device is closed */
}
static unsigned int vrf_default_advmss(const struct dst_entry *dst)
{
return 65535 - 40;
}
static struct dst_ops vrf_dst_ops = {
.family = AF_INET,
.local_out = vrf_ip_local_out,
.check = vrf_ip_check,
.mtu = vrf_v4_mtu,
.destroy = vrf_dst_destroy,
.default_advmss = vrf_default_advmss,
};
/* 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.
*/
#if IS_ENABLED(CONFIG_IPV6)
static bool check_ipv6_frame(const struct sk_buff *skb)
{
const struct ipv6hdr *ipv6h = (struct ipv6hdr *)skb->data;
size_t hlen = sizeof(*ipv6h);
bool rc = true;
if (skb->len < hlen)
goto out;
if (ipv6h->nexthdr == NEXTHDR_ICMP) {
const struct icmp6hdr *icmph;
if (skb->len < hlen + sizeof(*icmph))
goto out;
icmph = (struct icmp6hdr *)(skb->data + sizeof(*ipv6h));
switch (icmph->icmp6_type) {
case NDISC_ROUTER_SOLICITATION:
case NDISC_ROUTER_ADVERTISEMENT:
case NDISC_NEIGHBOUR_SOLICITATION:
case NDISC_NEIGHBOUR_ADVERTISEMENT:
case NDISC_REDIRECT:
rc = false;
break;
}
}
out:
return rc;
}
#else
static bool check_ipv6_frame(const struct sk_buff *skb)
{
return false;
}
#endif
static bool is_ip_rx_frame(struct sk_buff *skb)
{
switch (skb->protocol) {
case htons(ETH_P_IP):
return true;
case htons(ETH_P_IPV6):
return check_ipv6_frame(skb);
}
return false;
}
static void vrf_tx_error(struct net_device *vrf_dev, struct sk_buff *skb)
{
vrf_dev->stats.tx_errors++;
kfree_skb(skb);
}
/* note: already called with rcu_read_lock */
static rx_handler_result_t vrf_handle_frame(struct sk_buff **pskb)
{
struct sk_buff *skb = *pskb;
if (is_ip_rx_frame(skb)) {
struct net_device *dev = vrf_master_get_rcu(skb->dev);
struct pcpu_dstats *dstats = this_cpu_ptr(dev->dstats);
u64_stats_update_begin(&dstats->syncp);
dstats->rx_pkts++;
dstats->rx_bytes += skb->len;
u64_stats_update_end(&dstats->syncp);
skb->dev = dev;
return RX_HANDLER_ANOTHER;
}
return RX_HANDLER_PASS;
}
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;
}
#if IS_ENABLED(CONFIG_IPV6)
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_L3MDEV_SRC | 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);
skb_dst_set(skb, dst);
ret = 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
static int vrf_send_v4_prep(struct sk_buff *skb, struct flowi4 *fl4,
struct net_device *vrf_dev)
{
struct rtable *rt;
int err = 1;
rt = ip_route_output_flow(dev_net(vrf_dev), fl4, NULL);
if (IS_ERR(rt))
goto out;
/* TO-DO: what about broadcast ? */
if (rt->rt_type != RTN_UNICAST && rt->rt_type != RTN_LOCAL) {
ip_rt_put(rt);
goto out;
}
skb_dst_drop(skb);
skb_dst_set(skb, &rt->dst);
err = 0;
out:
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_L3MDEV_SRC |
FLOWI_FLAG_SKIP_NH_OIF,
.daddr = ip4h->daddr,
};
if (vrf_send_v4_prep(skb, &fl4, vrf_dev))
goto err;
if (!ip4h->saddr) {
ip4h->saddr = inet_select_addr(skb_dst(skb)->dev, 0,
RT_SCOPE_LINK);
}
ret = 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)
{
/* strip the ethernet header added for pass through VRF device */
__skb_pull(skb, skb_network_offset(skb));
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)
static struct dst_entry *vrf_ip6_check(struct dst_entry *dst, u32 cookie)
{
return dst;
}
static struct dst_ops vrf_dst_ops6 = {
.family = AF_INET6,
.local_out = ip6_local_out,
.check = vrf_ip6_check,
.mtu = vrf_v4_mtu,
.destroy = vrf_dst_destroy,
.default_advmss = vrf_default_advmss,
};
static int init_dst_ops6_kmem_cachep(void)
{
vrf_dst_ops6.kmem_cachep = kmem_cache_create("vrf_ip6_dst_cache",
sizeof(struct rt6_info),
0,
SLAB_HWCACHE_ALIGN,
NULL);
if (!vrf_dst_ops6.kmem_cachep)
return -ENOMEM;
return 0;
}
static void free_dst_ops6_kmem_cachep(void)
{
kmem_cache_destroy(vrf_dst_ops6.kmem_cachep);
}
static int vrf_input6(struct sk_buff *skb)
{
skb->dev->stats.rx_errors++;
kfree_skb(skb);
return 0;
}
/* 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));
}
static void vrf_rt6_destroy(struct net_vrf *vrf)
{
dst_destroy(&vrf->rt6->dst);
free_percpu(vrf->rt6->rt6i_pcpu);
vrf->rt6 = NULL;
}
static int vrf_rt6_create(struct net_device *dev)
{
struct net_vrf *vrf = netdev_priv(dev);
struct dst_entry *dst;
struct rt6_info *rt6;
int cpu;
int rc = -ENOMEM;
rt6 = dst_alloc(&vrf_dst_ops6, dev, 0,
DST_OBSOLETE_NONE,
(DST_HOST | DST_NOPOLICY | DST_NOXFRM));
if (!rt6)
goto out;
dst = &rt6->dst;
rt6->rt6i_pcpu = alloc_percpu_gfp(struct rt6_info *, GFP_KERNEL);
if (!rt6->rt6i_pcpu) {
dst_destroy(dst);
goto out;
}
for_each_possible_cpu(cpu) {
struct rt6_info **p = per_cpu_ptr(rt6->rt6i_pcpu, cpu);
*p = NULL;
}
memset(dst + 1, 0, sizeof(*rt6) - sizeof(*dst));
INIT_LIST_HEAD(&rt6->rt6i_siblings);
INIT_LIST_HEAD(&rt6->rt6i_uncached);
rt6->dst.input = vrf_input6;
rt6->dst.output = vrf_output6;
rt6->rt6i_table = fib6_get_table(dev_net(dev), vrf->tb_id);
atomic_set(&rt6->dst.__refcnt, 2);
vrf->rt6 = rt6;
rc = 0;
out:
return rc;
}
#else
static int init_dst_ops6_kmem_cachep(void)
{
return 0;
}
static void free_dst_ops6_kmem_cachep(void)
{
}
static void vrf_rt6_destroy(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));
}
static void vrf_rtable_destroy(struct net_vrf *vrf)
{
struct dst_entry *dst = (struct dst_entry *)vrf->rth;
dst_destroy(dst);
vrf->rth = NULL;
}
static struct rtable *vrf_rtable_create(struct net_device *dev)
{
struct net_vrf *vrf = netdev_priv(dev);
struct rtable *rth;
rth = dst_alloc(&vrf_dst_ops, dev, 2,
DST_OBSOLETE_NONE,
(DST_HOST | DST_NOPOLICY | DST_NOXFRM));
if (rth) {
rth->dst.output = vrf_output;
rth->rt_genid = rt_genid_ipv4(dev_net(dev));
rth->rt_flags = 0;
rth->rt_type = RTN_UNICAST;
rth->rt_is_input = 0;
rth->rt_iif = 0;
rth->rt_pmtu = 0;
rth->rt_gateway = 0;
rth->rt_uses_gateway = 0;
rth->rt_table_id = vrf->tb_id;
INIT_LIST_HEAD(&rth->rt_uncached);
rth->rt_uncached_list = NULL;
}
return rth;
}
/**************************** 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 struct slave *__vrf_find_slave_dev(struct slave_queue *queue,
struct net_device *dev)
{
struct list_head *head = &queue->all_slaves;
struct slave *slave;
list_for_each_entry(slave, head, list) {
if (slave->dev == dev)
return slave;
}
return NULL;
}
/* inverse of __vrf_insert_slave */
static void __vrf_remove_slave(struct slave_queue *queue, struct slave *slave)
{
list_del(&slave->list);
}
static void __vrf_insert_slave(struct slave_queue *queue, struct slave *slave)
{
list_add(&slave->list, &queue->all_slaves);
}
static int do_vrf_add_slave(struct net_device *dev, struct net_device *port_dev)
{
struct slave *slave = kzalloc(sizeof(*slave), GFP_KERNEL);
struct net_vrf *vrf = netdev_priv(dev);
struct slave_queue *queue = &vrf->queue;
int ret = -ENOMEM;
if (!slave)
goto out_fail;
slave->dev = port_dev;
/* register the packet handler for slave ports */
ret = netdev_rx_handler_register(port_dev, vrf_handle_frame, dev);
if (ret) {
netdev_err(port_dev,
"Device %s failed to register rx_handler\n",
port_dev->name);
goto out_fail;
}
ret = netdev_master_upper_dev_link(port_dev, dev);
if (ret < 0)
goto out_unregister;
port_dev->priv_flags |= IFF_L3MDEV_SLAVE;
__vrf_insert_slave(queue, slave);
cycle_netdev(port_dev);
return 0;
out_unregister:
netdev_rx_handler_unregister(port_dev);
out_fail:
kfree(slave);
return ret;
}
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)
{
struct net_vrf *vrf = netdev_priv(dev);
struct slave_queue *queue = &vrf->queue;
struct slave *slave;
netdev_upper_dev_unlink(port_dev, dev);
port_dev->priv_flags &= ~IFF_L3MDEV_SLAVE;
netdev_rx_handler_unregister(port_dev);
cycle_netdev(port_dev);
slave = __vrf_find_slave_dev(queue, port_dev);
if (slave)
__vrf_remove_slave(queue, slave);
kfree(slave);
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 slave_queue *queue = &vrf->queue;
struct list_head *head = &queue->all_slaves;
struct slave *slave, *next;
vrf_rtable_destroy(vrf);
vrf_rt6_destroy(vrf);
list_for_each_entry_safe(slave, next, head, list)
vrf_del_slave(dev, slave->dev);
free_percpu(dev->dstats);
dev->dstats = NULL;
}
static int vrf_dev_init(struct net_device *dev)
{
struct net_vrf *vrf = netdev_priv(dev);
INIT_LIST_HEAD(&vrf->queue.all_slaves);
dev->dstats = netdev_alloc_pcpu_stats(struct pcpu_dstats);
if (!dev->dstats)
goto out_nomem;
/* create the default dst which points back to us */
vrf->rth = vrf_rtable_create(dev);
if (!vrf->rth)
goto out_stats;
if (vrf_rt6_create(dev) != 0)
goto out_rth;
dev->flags = IFF_MASTER | IFF_NOARP;
return 0;
out_rth:
vrf_rtable_destroy(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 struct rtable *vrf_get_rtable(const struct net_device *dev,
const struct flowi4 *fl4)
{
struct rtable *rth = NULL;
if (!(fl4->flowi4_flags & FLOWI_FLAG_L3MDEV_SRC)) {
struct net_vrf *vrf = netdev_priv(dev);
rth = vrf->rth;
atomic_inc(&rth->dst.__refcnt);
}
return rth;
}
/* called under rcu_read_lock */
static void vrf_get_saddr(struct net_device *dev, struct flowi4 *fl4)
{
struct fib_result res = { .tclassid = 0 };
struct net *net = dev_net(dev);
u32 orig_tos = fl4->flowi4_tos;
u8 flags = fl4->flowi4_flags;
u8 scope = fl4->flowi4_scope;
u8 tos = RT_FL_TOS(fl4);
if (unlikely(!fl4->daddr))
return;
fl4->flowi4_flags |= FLOWI_FLAG_SKIP_NH_OIF;
fl4->flowi4_iif = LOOPBACK_IFINDEX;
fl4->flowi4_tos = tos & IPTOS_RT_MASK;
fl4->flowi4_scope = ((tos & RTO_ONLINK) ?
RT_SCOPE_LINK : RT_SCOPE_UNIVERSE);
if (!fib_lookup(net, fl4, &res, 0)) {
if (res.type == RTN_LOCAL)
fl4->saddr = res.fi->fib_prefsrc ? : fl4->daddr;
else
fib_select_path(net, &res, fl4, -1);
}
fl4->flowi4_flags = flags;
fl4->flowi4_tos = orig_tos;
fl4->flowi4_scope = scope;
}
#if IS_ENABLED(CONFIG_IPV6)
static struct dst_entry *vrf_get_rt6_dst(const struct net_device *dev,
const struct flowi6 *fl6)
{
struct rt6_info *rt = NULL;
if (!(fl6->flowi6_flags & FLOWI_FLAG_L3MDEV_SRC)) {
struct net_vrf *vrf = netdev_priv(dev);
rt = vrf->rt6;
atomic_inc(&rt->dst.__refcnt);
}
return (struct dst_entry *)rt;
}
#endif
static const struct l3mdev_ops vrf_l3mdev_ops = {
.l3mdev_fib_table = vrf_fib_table,
.l3mdev_get_rtable = vrf_get_rtable,
.l3mdev_get_saddr = vrf_get_saddr,
#if IS_ENABLED(CONFIG_IPV6)
.l3mdev_get_rt6_dst = vrf_get_rt6_dst,
#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 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;
}
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);
if (!data || !data[IFLA_VRF_TABLE])
return -EINVAL;
vrf->tb_id = nla_get_u32(data[IFLA_VRF_TABLE]);
dev->priv_flags |= IFF_L3MDEV_MASTER;
return register_netdevice(dev);
}
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 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,
.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;
vrf_dst_ops.kmem_cachep =
kmem_cache_create("vrf_ip_dst_cache",
sizeof(struct rtable), 0,
SLAB_HWCACHE_ALIGN,
NULL);
if (!vrf_dst_ops.kmem_cachep)
return -ENOMEM;
rc = init_dst_ops6_kmem_cachep();
if (rc != 0)
goto error2;
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);
free_dst_ops6_kmem_cachep();
error2:
kmem_cache_destroy(vrf_dst_ops.kmem_cachep);
return rc;
}
static void __exit vrf_cleanup_module(void)
{
rtnl_link_unregister(&vrf_link_ops);
unregister_netdevice_notifier(&vrf_notifier_block);
kmem_cache_destroy(vrf_dst_ops.kmem_cachep);
free_dst_ops6_kmem_cachep();
}
module_init(vrf_init_module);
module_exit(vrf_cleanup_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);