Commit 0e2d6865 authored by David S. Miller's avatar David S. Miller

Merge branch 'mpls'

Robert Shearman says:

====================
mpls: ABI changes for security and correctness

V2:
 - don't treat loopback interfaces specially by enabling mpls by
   default

These changes make mpls not be enabled by default on all
interfaces when in use for security, along with ensuring that a label
not valid as an outgoing label can be added in mpls routes.

This series contains three ABI/behaviour-affecting changes which have
been split out from "[PATCH net-next v4 0/6] mpls: Behaviour-changing
improvements" without any further modification. These changes need to
be considered for 4.1 otherwise we'll be stuck with the current
behaviour/ABI forever.
====================
Reviewed-by: default avatar"Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parents 909d9faa 5a9ab017
......@@ -18,3 +18,12 @@ platform_labels - INTEGER
Possible values: 0 - 1048575
Default: 0
conf/<interface>/input - BOOL
Control whether packets can be input on this interface.
If disabled, packets will be discarded without further
processing.
0 - disabled (default)
not 0 - enabled
......@@ -60,6 +60,7 @@ struct phy_device;
struct wireless_dev;
/* 802.15.4 specific */
struct wpan_dev;
struct mpls_dev;
void netdev_set_default_ethtool_ops(struct net_device *dev,
const struct ethtool_ops *ops);
......@@ -1627,6 +1628,9 @@ struct net_device {
void *ax25_ptr;
struct wireless_dev *ieee80211_ptr;
struct wpan_dev *ieee802154_ptr;
#if IS_ENABLED(CONFIG_MPLS_ROUTING)
struct mpls_dev __rcu *mpls_ptr;
#endif
/*
* Cache lines mostly used on receive path (including eth_type_trans())
......
......@@ -53,6 +53,11 @@ static struct mpls_route *mpls_route_input_rcu(struct net *net, unsigned index)
return rt;
}
static inline struct mpls_dev *mpls_dev_get(const struct net_device *dev)
{
return rcu_dereference_rtnl(dev->mpls_ptr);
}
static bool mpls_output_possible(const struct net_device *dev)
{
return dev && (dev->flags & IFF_UP) && netif_carrier_ok(dev);
......@@ -136,6 +141,7 @@ static int mpls_forward(struct sk_buff *skb, struct net_device *dev,
struct mpls_route *rt;
struct mpls_entry_decoded dec;
struct net_device *out_dev;
struct mpls_dev *mdev;
unsigned int hh_len;
unsigned int new_header_size;
unsigned int mtu;
......@@ -143,6 +149,10 @@ static int mpls_forward(struct sk_buff *skb, struct net_device *dev,
/* Careful this entire function runs inside of an rcu critical section */
mdev = mpls_dev_get(dev);
if (!mdev || !mdev->input_enabled)
goto drop;
if (skb->pkt_type != PACKET_HOST)
goto drop;
......@@ -352,9 +362,9 @@ static int mpls_route_add(struct mpls_route_config *cfg)
if (!dev)
goto errout;
/* For now just support ethernet devices */
/* Ensure this is a supported device */
err = -EINVAL;
if ((dev->type != ARPHRD_ETHER) && (dev->type != ARPHRD_LOOPBACK))
if (!mpls_dev_get(dev))
goto errout;
err = -EINVAL;
......@@ -428,10 +438,89 @@ static int mpls_route_del(struct mpls_route_config *cfg)
return err;
}
#define MPLS_PERDEV_SYSCTL_OFFSET(field) \
(&((struct mpls_dev *)0)->field)
static const struct ctl_table mpls_dev_table[] = {
{
.procname = "input",
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec,
.data = MPLS_PERDEV_SYSCTL_OFFSET(input_enabled),
},
{ }
};
static int mpls_dev_sysctl_register(struct net_device *dev,
struct mpls_dev *mdev)
{
char path[sizeof("net/mpls/conf/") + IFNAMSIZ];
struct ctl_table *table;
int i;
table = kmemdup(&mpls_dev_table, sizeof(mpls_dev_table), GFP_KERNEL);
if (!table)
goto out;
/* Table data contains only offsets relative to the base of
* the mdev at this point, so make them absolute.
*/
for (i = 0; i < ARRAY_SIZE(mpls_dev_table); i++)
table[i].data = (char *)mdev + (uintptr_t)table[i].data;
snprintf(path, sizeof(path), "net/mpls/conf/%s", dev->name);
mdev->sysctl = register_net_sysctl(dev_net(dev), path, table);
if (!mdev->sysctl)
goto free;
return 0;
free:
kfree(table);
out:
return -ENOBUFS;
}
static void mpls_dev_sysctl_unregister(struct mpls_dev *mdev)
{
struct ctl_table *table;
table = mdev->sysctl->ctl_table_arg;
unregister_net_sysctl_table(mdev->sysctl);
kfree(table);
}
static struct mpls_dev *mpls_add_dev(struct net_device *dev)
{
struct mpls_dev *mdev;
int err = -ENOMEM;
ASSERT_RTNL();
mdev = kzalloc(sizeof(*mdev), GFP_KERNEL);
if (!mdev)
return ERR_PTR(err);
err = mpls_dev_sysctl_register(dev, mdev);
if (err)
goto free;
rcu_assign_pointer(dev->mpls_ptr, mdev);
return mdev;
free:
kfree(mdev);
return ERR_PTR(err);
}
static void mpls_ifdown(struct net_device *dev)
{
struct mpls_route __rcu **platform_label;
struct net *net = dev_net(dev);
struct mpls_dev *mdev;
unsigned index;
platform_label = rtnl_dereference(net->mpls.platform_label);
......@@ -443,14 +532,35 @@ static void mpls_ifdown(struct net_device *dev)
continue;
rt->rt_dev = NULL;
}
mdev = mpls_dev_get(dev);
if (!mdev)
return;
mpls_dev_sysctl_unregister(mdev);
RCU_INIT_POINTER(dev->mpls_ptr, NULL);
kfree(mdev);
}
static int mpls_dev_notify(struct notifier_block *this, unsigned long event,
void *ptr)
{
struct net_device *dev = netdev_notifier_info_to_dev(ptr);
struct mpls_dev *mdev;
switch(event) {
case NETDEV_REGISTER:
/* For now just support ethernet devices */
if ((dev->type == ARPHRD_ETHER) ||
(dev->type == ARPHRD_LOOPBACK)) {
mdev = mpls_add_dev(dev);
if (IS_ERR(mdev))
return notifier_from_errno(PTR_ERR(mdev));
}
break;
case NETDEV_UNREGISTER:
mpls_ifdown(dev);
break;
......@@ -536,6 +646,15 @@ int nla_get_labels(const struct nlattr *nla,
if ((dec.bos != bos) || dec.ttl || dec.tc)
return -EINVAL;
switch (dec.label) {
case LABEL_IMPLICIT_NULL:
/* RFC3032: This is a label that an LSR may
* assign and distribute, but which never
* actually appears in the encapsulation.
*/
return -EINVAL;
}
label[i] = dec.label;
}
*labels = nla_labels;
......@@ -912,7 +1031,7 @@ static int mpls_platform_labels(struct ctl_table *table, int write,
return ret;
}
static struct ctl_table mpls_table[] = {
static const struct ctl_table mpls_table[] = {
{
.procname = "platform_labels",
.data = NULL,
......
......@@ -22,6 +22,12 @@ struct mpls_entry_decoded {
u8 bos;
};
struct mpls_dev {
int input_enabled;
struct ctl_table_header *sysctl;
};
struct sk_buff;
static inline struct mpls_shim_hdr *mpls_hdr(const struct sk_buff *skb)
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment