diff options
| -rw-r--r-- | include/linux/netdevice.h | 14 | ||||
| -rw-r--r-- | net/core/dev.c | 239 |
2 files changed, 249 insertions, 4 deletions
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index c5031a45e18..e324601f48e 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -1174,6 +1174,8 @@ struct net_device { * which this device is member of. */ + struct list_head upper_dev_list; /* List of upper devices */ + /* Interface address info used in eth_type_trans() */ unsigned char *dev_addr; /* hw address, (before bcast because most packets are @@ -2636,6 +2638,18 @@ extern int netdev_max_backlog; extern int netdev_tstamp_prequeue; extern int weight_p; extern int bpf_jit_enable; + +extern bool netdev_has_upper_dev(struct net_device *dev, + struct net_device *upper_dev); +extern bool netdev_has_any_upper_dev(struct net_device *dev); +extern struct net_device *netdev_master_upper_dev_get(struct net_device *dev); +extern struct net_device *netdev_master_upper_dev_get_rcu(struct net_device *dev); +extern int netdev_upper_dev_link(struct net_device *dev, + struct net_device *upper_dev); +extern int netdev_master_upper_dev_link(struct net_device *dev, + struct net_device *upper_dev); +extern void netdev_upper_dev_unlink(struct net_device *dev, + struct net_device *upper_dev); extern int netdev_set_master(struct net_device *dev, struct net_device *master); extern int netdev_set_bond_master(struct net_device *dev, struct net_device *master); diff --git a/net/core/dev.c b/net/core/dev.c index bddb2f2ccaa..53a9fefbc9a 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -4600,6 +4600,232 @@ static int __init dev_proc_init(void) #endif /* CONFIG_PROC_FS */ +struct netdev_upper { + struct net_device *dev; + bool master; + struct list_head list; + struct rcu_head rcu; + struct list_head search_list; +}; + +static void __append_search_uppers(struct list_head *search_list, + struct net_device *dev) +{ + struct netdev_upper *upper; + + list_for_each_entry(upper, &dev->upper_dev_list, list) { + /* check if this upper is not already in search list */ + if (list_empty(&upper->search_list)) + list_add_tail(&upper->search_list, search_list); + } +} + +static bool __netdev_search_upper_dev(struct net_device *dev, + struct net_device *upper_dev) +{ + LIST_HEAD(search_list); + struct netdev_upper *upper; + struct netdev_upper *tmp; + bool ret = false; + + __append_search_uppers(&search_list, dev); + list_for_each_entry(upper, &search_list, search_list) { + if (upper->dev == upper_dev) { + ret = true; + break; + } + __append_search_uppers(&search_list, upper->dev); + } + list_for_each_entry_safe(upper, tmp, &search_list, search_list) + INIT_LIST_HEAD(&upper->search_list); + return ret; +} + +static struct netdev_upper *__netdev_find_upper(struct net_device *dev, + struct net_device *upper_dev) +{ + struct netdev_upper *upper; + + list_for_each_entry(upper, &dev->upper_dev_list, list) { + if (upper->dev == upper_dev) + return upper; + } + return NULL; +} + +/** + * netdev_has_upper_dev - Check if device is linked to an upper device + * @dev: device + * @upper_dev: upper device to check + * + * Find out if a device is linked to specified upper device and return true + * in case it is. Note that this checks only immediate upper device, + * not through a complete stack of devices. The caller must hold the RTNL lock. + */ +bool netdev_has_upper_dev(struct net_device *dev, + struct net_device *upper_dev) +{ + ASSERT_RTNL(); + + return __netdev_find_upper(dev, upper_dev); +} +EXPORT_SYMBOL(netdev_has_upper_dev); + +/** + * netdev_has_any_upper_dev - Check if device is linked to some device + * @dev: device + * + * Find out if a device is linked to an upper device and return true in case + * it is. The caller must hold the RTNL lock. + */ +bool netdev_has_any_upper_dev(struct net_device *dev) +{ + ASSERT_RTNL(); + + return !list_empty(&dev->upper_dev_list); +} +EXPORT_SYMBOL(netdev_has_any_upper_dev); + +/** + * netdev_master_upper_dev_get - Get master upper device + * @dev: device + * + * Find a master upper device and return pointer to it or NULL in case + * it's not there. The caller must hold the RTNL lock. + */ +struct net_device *netdev_master_upper_dev_get(struct net_device *dev) +{ + struct netdev_upper *upper; + + ASSERT_RTNL(); + + if (list_empty(&dev->upper_dev_list)) + return NULL; + + upper = list_first_entry(&dev->upper_dev_list, + struct netdev_upper, list); + if (likely(upper->master)) + return upper->dev; + return NULL; +} +EXPORT_SYMBOL(netdev_master_upper_dev_get); + +/** + * netdev_master_upper_dev_get_rcu - Get master upper device + * @dev: device + * + * Find a master upper device and return pointer to it or NULL in case + * it's not there. The caller must hold the RCU read lock. + */ +struct net_device *netdev_master_upper_dev_get_rcu(struct net_device *dev) +{ + struct netdev_upper *upper; + + upper = list_first_or_null_rcu(&dev->upper_dev_list, + struct netdev_upper, list); + if (upper && likely(upper->master)) + return upper->dev; + return NULL; +} +EXPORT_SYMBOL(netdev_master_upper_dev_get_rcu); + +static int __netdev_upper_dev_link(struct net_device *dev, + struct net_device *upper_dev, bool master) +{ + struct netdev_upper *upper; + + ASSERT_RTNL(); + + if (dev == upper_dev) + return -EBUSY; + + /* To prevent loops, check if dev is not upper device to upper_dev. */ + if (__netdev_search_upper_dev(upper_dev, dev)) + return -EBUSY; + + if (__netdev_find_upper(dev, upper_dev)) + return -EEXIST; + + if (master && netdev_master_upper_dev_get(dev)) + return -EBUSY; + + upper = kmalloc(sizeof(*upper), GFP_KERNEL); + if (!upper) + return -ENOMEM; + + upper->dev = upper_dev; + upper->master = master; + INIT_LIST_HEAD(&upper->search_list); + + /* Ensure that master upper link is always the first item in list. */ + if (master) + list_add_rcu(&upper->list, &dev->upper_dev_list); + else + list_add_tail_rcu(&upper->list, &dev->upper_dev_list); + dev_hold(upper_dev); + + return 0; +} + +/** + * netdev_upper_dev_link - Add a link to the upper device + * @dev: device + * @upper_dev: new upper device + * + * Adds a link to device which is upper to this one. The caller must hold + * the RTNL lock. On a failure a negative errno code is returned. + * On success the reference counts are adjusted and the function + * returns zero. + */ +int netdev_upper_dev_link(struct net_device *dev, + struct net_device *upper_dev) +{ + return __netdev_upper_dev_link(dev, upper_dev, false); +} +EXPORT_SYMBOL(netdev_upper_dev_link); + +/** + * netdev_master_upper_dev_link - Add a master link to the upper device + * @dev: device + * @upper_dev: new upper device + * + * Adds a link to device which is upper to this one. In this case, only + * one master upper device can be linked, although other non-master devices + * might be linked as well. The caller must hold the RTNL lock. + * On a failure a negative errno code is returned. On success the reference + * counts are adjusted and the function returns zero. + */ +int netdev_master_upper_dev_link(struct net_device *dev, + struct net_device *upper_dev) +{ + return __netdev_upper_dev_link(dev, upper_dev, true); +} +EXPORT_SYMBOL(netdev_master_upper_dev_link); + +/** + * netdev_upper_dev_unlink - Removes a link to upper device + * @dev: device + * @upper_dev: new upper device + * + * Removes a link to device which is upper to this one. The caller must hold + * the RTNL lock. + */ +void netdev_upper_dev_unlink(struct net_device *dev, + struct net_device *upper_dev) +{ + struct netdev_upper *upper; + + ASSERT_RTNL(); + + upper = __netdev_find_upper(dev, upper_dev); + if (!upper) + return; + list_del_rcu(&upper->list); + dev_put(upper_dev); + kfree_rcu(upper, rcu); +} +EXPORT_SYMBOL(netdev_upper_dev_unlink); + /** * netdev_set_master - set up master pointer * @slave: slave device @@ -4613,19 +4839,23 @@ static int __init dev_proc_init(void) int netdev_set_master(struct net_device *slave, struct net_device *master) { struct net_device *old = slave->master; + int err; ASSERT_RTNL(); if (master) { if (old) return -EBUSY; - dev_hold(master); + err = netdev_master_upper_dev_link(slave, master); + if (err) + return err; } slave->master = master; if (old) - dev_put(old); + netdev_upper_dev_unlink(slave, master); + return 0; } EXPORT_SYMBOL(netdev_set_master); @@ -5503,8 +5733,8 @@ static void rollback_registered_many(struct list_head *head) if (dev->netdev_ops->ndo_uninit) dev->netdev_ops->ndo_uninit(dev); - /* Notifier chain MUST detach us from master device. */ - WARN_ON(dev->master); + /* Notifier chain MUST detach us all upper devices. */ + WARN_ON(netdev_has_any_upper_dev(dev)); /* Remove entries from kobject tree */ netdev_unregister_kobject(dev); @@ -6212,6 +6442,7 @@ struct net_device *alloc_netdev_mqs(int sizeof_priv, const char *name, INIT_LIST_HEAD(&dev->napi_list); INIT_LIST_HEAD(&dev->unreg_list); INIT_LIST_HEAD(&dev->link_watch_list); + INIT_LIST_HEAD(&dev->upper_dev_list); dev->priv_flags = IFF_XMIT_DST_RELEASE; setup(dev); |