From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alexis Bauvin Subject: [RFC v4 4/5] netdev: add netdev_is_upper_master Date: Thu, 22 Nov 2018 02:07:12 +0100 Message-ID: <20181122010713.3995-5-abauvin@scaleway.com> References: <20181122010713.3995-1-abauvin@scaleway.com> Cc: netdev@vger.kernel.org, abauvin@scaleway.com, akherbouche@scaleway.com To: dsa@cumulusnetworks.com, roopa@cumulusnetworks.com Return-path: Received: from mail.online.net ([62.210.16.11]:41032 "EHLO mail.online.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2391246AbeKVLoV (ORCPT ); Thu, 22 Nov 2018 06:44:21 -0500 In-Reply-To: <20181122010713.3995-1-abauvin@scaleway.com> Sender: netdev-owner@vger.kernel.org List-ID: In preparation of next patch, this function allows to check if a device is a master, be it direct or indirect, of another one. It walks up the master chain until it finds the device, or there is no more master. This allows to check e.g. if br-blue is a master of eth0: +----------+ | vrf-blue | +----+-----+ | +----+----+ | br-blue | +----+----+ | +---+---+ | bond0 | +--+-+--+ | | +--+ +--+ | | +---+--+ +--+---+ | eth0 | | eth1 | +------+ +------+ Signed-off-by: Alexis Bauvin Reviewed-by: Amine Kherbouche Tested-by: Amine Kherbouche --- include/linux/netdevice.h | 1 + net/core/dev.c | 17 +++++++++++++++++ 2 files changed, 18 insertions(+) diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index d837dad24b4c..102f79337d7c 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -4212,6 +4212,7 @@ void *netdev_lower_dev_get_private(struct net_device *dev, struct net_device *lower_dev); void netdev_lower_state_changed(struct net_device *lower_dev, void *lower_state_info); +bool netdev_is_upper_master(struct net_device *dev, struct net_device *master); /* RSS keys are 40 or 52 bytes long */ #define NETDEV_RSS_KEY_LEN 52 diff --git a/net/core/dev.c b/net/core/dev.c index 93243479085f..12459036d0da 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -7225,6 +7225,23 @@ void netdev_lower_state_changed(struct net_device *lower_dev, } EXPORT_SYMBOL(netdev_lower_state_changed); +/** + * netdev_is_upper_master - Test if a device is a master, direct or indirect, + * of another one. + * @dev: device to start looking from + * @master: device to test if master of dev + */ +bool netdev_is_upper_master(struct net_device *dev, struct net_device *master) +{ + if (!dev) + return false; + + if (dev->ifindex == master->ifindex) + return true; + return netdev_is_upper_master(netdev_master_upper_dev_get(dev), master); +} +EXPORT_SYMBOL(netdev_is_upper_master); + static void dev_change_rx_flags(struct net_device *dev, int flags) { const struct net_device_ops *ops = dev->netdev_ops; --