mctp: Pass flow data & flow release events to drivers

Now that we have an extension for MCTP data in skbs, populate the flow
when a key has been created for the packet, and add a device driver
operation to inform of flow destruction.

Includes a fix for a warning with test builds:
Reported-by: kernel test robot <lkp@intel.com>

Signed-off-by: Jeremy Kerr <jk@codeconstruct.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Jeremy Kerr 2021-10-29 11:01:45 +08:00 committed by David S. Miller
parent 78476d315e
commit 67737c4572
4 changed files with 126 additions and 2 deletions

View File

@ -152,6 +152,12 @@ struct mctp_sk_key {
/* expiry timeout; valid (above) cleared on expiry */
unsigned long expiry;
/* free to use for device flow state tracking. Initialised to
* zero on initial key creation
*/
unsigned long dev_flow_state;
struct mctp_dev *dev;
};
struct mctp_skb_cb {

View File

@ -14,6 +14,8 @@
#include <linux/types.h>
#include <linux/refcount.h>
struct mctp_sk_key;
struct mctp_dev {
struct net_device *dev;
@ -21,6 +23,8 @@ struct mctp_dev {
unsigned int net;
const struct mctp_netdev_ops *ops;
/* Only modified under RTNL. Reads have addrs_lock held */
u8 *addrs;
size_t num_addrs;
@ -29,12 +33,24 @@ struct mctp_dev {
struct rcu_head rcu;
};
struct mctp_netdev_ops {
void (*release_flow)(struct mctp_dev *dev,
struct mctp_sk_key *key);
};
#define MCTP_INITIAL_DEFAULT_NET 1
struct mctp_dev *mctp_dev_get_rtnl(const struct net_device *dev);
struct mctp_dev *__mctp_dev_get(const struct net_device *dev);
int mctp_register_netdev(struct net_device *dev,
const struct mctp_netdev_ops *ops);
void mctp_unregister_netdev(struct net_device *dev);
void mctp_dev_hold(struct mctp_dev *mdev);
void mctp_dev_put(struct mctp_dev *mdev);
void mctp_dev_set_key(struct mctp_dev *dev, struct mctp_sk_key *key);
void mctp_dev_release_key(struct mctp_dev *dev, struct mctp_sk_key *key);
#endif /* __NET_MCTPDEVICE_H */

View File

@ -260,6 +260,24 @@ void mctp_dev_put(struct mctp_dev *mdev)
}
}
void mctp_dev_release_key(struct mctp_dev *dev, struct mctp_sk_key *key)
__must_hold(&key->lock)
{
if (!dev)
return;
if (dev->ops && dev->ops->release_flow)
dev->ops->release_flow(dev, key);
key->dev = NULL;
mctp_dev_put(dev);
}
void mctp_dev_set_key(struct mctp_dev *dev, struct mctp_sk_key *key)
__must_hold(&key->lock)
{
mctp_dev_hold(dev);
key->dev = dev;
}
static struct mctp_dev *mctp_add_dev(struct net_device *dev)
{
struct mctp_dev *mdev;
@ -414,6 +432,39 @@ static int mctp_dev_notify(struct notifier_block *this, unsigned long event,
return NOTIFY_OK;
}
static int mctp_register_netdevice(struct net_device *dev,
const struct mctp_netdev_ops *ops)
{
struct mctp_dev *mdev;
mdev = mctp_add_dev(dev);
if (IS_ERR(mdev))
return PTR_ERR(mdev);
mdev->ops = ops;
return register_netdevice(dev);
}
int mctp_register_netdev(struct net_device *dev,
const struct mctp_netdev_ops *ops)
{
int rc;
rtnl_lock();
rc = mctp_register_netdevice(dev, ops);
rtnl_unlock();
return rc;
}
EXPORT_SYMBOL_GPL(mctp_register_netdev);
void mctp_unregister_netdev(struct net_device *dev)
{
unregister_netdev(dev);
}
EXPORT_SYMBOL_GPL(mctp_unregister_netdev);
static struct rtnl_af_ops mctp_af_ops = {
.family = AF_MCTP,
.fill_link_af = mctp_fill_link_af,

View File

@ -29,6 +29,8 @@
static const unsigned int mctp_message_maxlen = 64 * 1024;
static const unsigned long mctp_key_lifetime = 6 * CONFIG_HZ;
static void mctp_flow_prepare_output(struct sk_buff *skb, struct mctp_dev *dev);
/* route output callbacks */
static int mctp_route_discard(struct mctp_route *route, struct sk_buff *skb)
{
@ -152,8 +154,19 @@ static struct mctp_sk_key *mctp_key_alloc(struct mctp_sock *msk,
void mctp_key_unref(struct mctp_sk_key *key)
{
if (refcount_dec_and_test(&key->refs))
kfree(key);
unsigned long flags;
if (!refcount_dec_and_test(&key->refs))
return;
/* even though no refs exist here, the lock allows us to stay
* consistent with the locking requirement of mctp_dev_release_key
*/
spin_lock_irqsave(&key->lock, flags);
mctp_dev_release_key(key->dev, key);
spin_unlock_irqrestore(&key->lock, flags);
kfree(key);
}
static int mctp_key_add(struct mctp_sk_key *key, struct mctp_sock *msk)
@ -204,6 +217,7 @@ static void __mctp_key_unlock_drop(struct mctp_sk_key *key, struct net *net,
key->reasm_head = NULL;
key->reasm_dead = true;
key->valid = false;
mctp_dev_release_key(key->dev, key);
spin_unlock_irqrestore(&key->lock, flags);
spin_lock_irqsave(&net->mctp.keys_lock, flags);
@ -222,6 +236,40 @@ static void __mctp_key_unlock_drop(struct mctp_sk_key *key, struct net *net,
}
#ifdef CONFIG_MCTP_FLOWS
static void mctp_skb_set_flow(struct sk_buff *skb, struct mctp_sk_key *key)
{
struct mctp_flow *flow;
flow = skb_ext_add(skb, SKB_EXT_MCTP);
if (!flow)
return;
refcount_inc(&key->refs);
flow->key = key;
}
static void mctp_flow_prepare_output(struct sk_buff *skb, struct mctp_dev *dev)
{
struct mctp_sk_key *key;
struct mctp_flow *flow;
flow = skb_ext_find(skb, SKB_EXT_MCTP);
if (!flow)
return;
key = flow->key;
if (WARN_ON(key->dev && key->dev != dev))
return;
mctp_dev_set_key(dev, key);
}
#else
static void mctp_skb_set_flow(struct sk_buff *skb, struct mctp_sk_key *key) {}
static void mctp_flow_prepare_output(struct sk_buff *skb, struct mctp_dev *dev) {}
#endif
static int mctp_frag_queue(struct mctp_sk_key *key, struct sk_buff *skb)
{
struct mctp_hdr *hdr = mctp_hdr(skb);
@ -465,6 +513,8 @@ static int mctp_route_output(struct mctp_route *route, struct sk_buff *skb)
return -EHOSTUNREACH;
}
mctp_flow_prepare_output(skb, route->dev);
rc = dev_queue_xmit(skb);
if (rc)
rc = net_xmit_errno(rc);
@ -803,6 +853,7 @@ int mctp_local_output(struct sock *sk, struct mctp_route *rt,
rc = PTR_ERR(key);
goto out_release;
}
mctp_skb_set_flow(skb, key);
/* done with the key in this scope */
mctp_key_unref(key);
tag |= MCTP_HDR_FLAG_TO;