From 67737c457281dd199ceb9e31b6ba7efd3bfe566d Mon Sep 17 00:00:00 2001 From: Jeremy Kerr Date: Fri, 29 Oct 2021 11:01:45 +0800 Subject: 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 Signed-off-by: Jeremy Kerr Signed-off-by: David S. Miller --- include/net/mctp.h | 6 ++++++ include/net/mctpdevice.h | 16 ++++++++++++++ net/mctp/device.c | 51 ++++++++++++++++++++++++++++++++++++++++++++ net/mctp/route.c | 55 ++++++++++++++++++++++++++++++++++++++++++++++-- 4 files changed, 126 insertions(+), 2 deletions(-) diff --git a/include/net/mctp.h b/include/net/mctp.h index 7a5ba801703c..7e35ec79b909 100644 --- a/include/net/mctp.h +++ b/include/net/mctp.h @@ -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 { diff --git a/include/net/mctpdevice.h b/include/net/mctpdevice.h index 3a439463f055..5c0d04b5c12c 100644 --- a/include/net/mctpdevice.h +++ b/include/net/mctpdevice.h @@ -14,6 +14,8 @@ #include #include +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 */ diff --git a/net/mctp/device.c b/net/mctp/device.c index 3827d62f52c9..8799ee77e7b7 100644 --- a/net/mctp/device.c +++ b/net/mctp/device.c @@ -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, diff --git a/net/mctp/route.c b/net/mctp/route.c index 82cc10a2fb0c..46c44823edb7 100644 --- a/net/mctp/route.c +++ b/net/mctp/route.c @@ -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; -- cgit v1.2.3