From 1a3f060c1a47dba4e12ac21ce62b57666b9c4e95 Mon Sep 17 00:00:00 2001 From: David Ahern Date: Mon, 17 Oct 2016 19:15:44 -0700 Subject: net: Introduce new api for walking upper and lower devices This patch introduces netdev_walk_all_upper_dev_rcu, netdev_walk_all_lower_dev and netdev_walk_all_lower_dev_rcu. These functions recursively walk the adj_list of devices to determine all upper and lower devices. The functions take a callback function that is invoked for each device in the list. If the callback returns non-0, the walk is terminated and the functions return that code back to callers. v3 - simplified netdev_has_upper_dev_all_rcu and __netdev_has_upper_dev and removed typecast as suggested by Stephen v2 - fixed definition of netdev_next_lower_dev_rcu to mirror the upper_dev version. Signed-off-by: David Ahern Signed-off-by: David S. Miller --- net/core/dev.c | 155 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 155 insertions(+) (limited to 'net') diff --git a/net/core/dev.c b/net/core/dev.c index f67fd16615bb..fc48337cfab8 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -5155,6 +5155,31 @@ bool netdev_has_upper_dev(struct net_device *dev, } EXPORT_SYMBOL(netdev_has_upper_dev); +/** + * netdev_has_upper_dev_all - 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 the entire upper device chain. + * The caller must hold rcu lock. + */ + +static int __netdev_has_upper_dev(struct net_device *upper_dev, void *data) +{ + struct net_device *dev = data; + + return upper_dev == dev; +} + +bool netdev_has_upper_dev_all_rcu(struct net_device *dev, + struct net_device *upper_dev) +{ + return !!netdev_walk_all_upper_dev_rcu(dev, __netdev_has_upper_dev, + upper_dev); +} +EXPORT_SYMBOL(netdev_has_upper_dev_all_rcu); + /** * netdev_has_any_upper_dev - Check if device is linked to some device * @dev: device @@ -5255,6 +5280,51 @@ struct net_device *netdev_all_upper_get_next_dev_rcu(struct net_device *dev, } EXPORT_SYMBOL(netdev_all_upper_get_next_dev_rcu); +static struct net_device *netdev_next_upper_dev_rcu(struct net_device *dev, + struct list_head **iter) +{ + struct netdev_adjacent *upper; + + WARN_ON_ONCE(!rcu_read_lock_held() && !lockdep_rtnl_is_held()); + + upper = list_entry_rcu((*iter)->next, struct netdev_adjacent, list); + + if (&upper->list == &dev->adj_list.upper) + return NULL; + + *iter = &upper->list; + + return upper->dev; +} + +int netdev_walk_all_upper_dev_rcu(struct net_device *dev, + int (*fn)(struct net_device *dev, + void *data), + void *data) +{ + struct net_device *udev; + struct list_head *iter; + int ret; + + for (iter = &dev->adj_list.upper, + udev = netdev_next_upper_dev_rcu(dev, &iter); + udev; + udev = netdev_next_upper_dev_rcu(dev, &iter)) { + /* first is the upper device itself */ + ret = fn(udev, data); + if (ret) + return ret; + + /* then look at all of its upper devices */ + ret = netdev_walk_all_upper_dev_rcu(udev, fn, data); + if (ret) + return ret; + } + + return 0; +} +EXPORT_SYMBOL_GPL(netdev_walk_all_upper_dev_rcu); + /** * netdev_lower_get_next_private - Get the next ->private from the * lower neighbour list @@ -5361,6 +5431,49 @@ struct net_device *netdev_all_lower_get_next(struct net_device *dev, struct list } EXPORT_SYMBOL(netdev_all_lower_get_next); +static struct net_device *netdev_next_lower_dev(struct net_device *dev, + struct list_head **iter) +{ + struct netdev_adjacent *lower; + + lower = list_entry(*iter, struct netdev_adjacent, list); + + if (&lower->list == &dev->adj_list.lower) + return NULL; + + *iter = lower->list.next; + + return lower->dev; +} + +int netdev_walk_all_lower_dev(struct net_device *dev, + int (*fn)(struct net_device *dev, + void *data), + void *data) +{ + struct net_device *ldev; + struct list_head *iter; + int ret; + + for (iter = &dev->adj_list.lower, + ldev = netdev_next_lower_dev(dev, &iter); + ldev; + ldev = netdev_next_lower_dev(dev, &iter)) { + /* first is the lower device itself */ + ret = fn(ldev, data); + if (ret) + return ret; + + /* then look at all of its lower devices */ + ret = netdev_walk_all_lower_dev(ldev, fn, data); + if (ret) + return ret; + } + + return 0; +} +EXPORT_SYMBOL_GPL(netdev_walk_all_lower_dev); + /** * netdev_all_lower_get_next_rcu - Get the next device from all * lower neighbour list, RCU variant @@ -5382,6 +5495,48 @@ struct net_device *netdev_all_lower_get_next_rcu(struct net_device *dev, } EXPORT_SYMBOL(netdev_all_lower_get_next_rcu); +static struct net_device *netdev_next_lower_dev_rcu(struct net_device *dev, + struct list_head **iter) +{ + struct netdev_adjacent *lower; + + lower = list_entry_rcu((*iter)->next, struct netdev_adjacent, list); + if (&lower->list == &dev->adj_list.lower) + return NULL; + + *iter = &lower->list; + + return lower->dev; +} + +int netdev_walk_all_lower_dev_rcu(struct net_device *dev, + int (*fn)(struct net_device *dev, + void *data), + void *data) +{ + struct net_device *ldev; + struct list_head *iter; + int ret; + + for (iter = &dev->adj_list.lower, + ldev = netdev_next_lower_dev_rcu(dev, &iter); + ldev; + ldev = netdev_next_lower_dev_rcu(dev, &iter)) { + /* first is the lower device itself */ + ret = fn(ldev, data); + if (ret) + return ret; + + /* then look at all of its lower devices */ + ret = netdev_walk_all_lower_dev_rcu(ldev, fn, data); + if (ret) + return ret; + } + + return 0; +} +EXPORT_SYMBOL_GPL(netdev_walk_all_lower_dev_rcu); + /** * netdev_lower_get_first_private_rcu - Get the first ->private from the * lower neighbour list, RCU -- cgit