Re: [patch net-next] openvswitch: introduce rtnl ops stub

[Jiri Pirko <jiri@resnulli.us>]

Wed, Jun 25, 2014 at 10:34:27AM CEST, ebiederm@xmission.com wrote:
>Jiri Pirko <jiri@resnulli.us> writes:
>
>> This stub now allows userspace to see IFLA_INFO_KIND for ovs master and
>> IFLA_INFO_SLAVE_KIND for slave.
>>
>> Note that I added ops->setup check into newlink and dellink in order to
>> prevent creating and deleting openvswitch instances using rtnl for
>> now.
>
>Nacked-by: "Eric W. Biederman" <ebiederm@xmission.com>
>
>Don't add hacks to the core code to only satisfy your openvswitch
>device.
>
>If the change is justified make it a separate patch and describe why
>it is ok for everyone.  As this sits I think you have broken some
>other users of rtnl_link_ops.

Fair enough. Thanks Eric!

>
>Eric
>
>
>> Signed-off-by: Jiri Pirko <jiri@resnulli.us>
>> ---
>>  net/core/rtnetlink.c                 |  5 ++++-
>>  net/openvswitch/datapath.c           |  9 ++++++++-
>>  net/openvswitch/vport-internal_dev.c | 16 ++++++++++++++++
>>  net/openvswitch/vport-internal_dev.h |  2 ++
>>  4 files changed, 30 insertions(+), 2 deletions(-)
>>
>> diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
>> index 1063996..84affd7 100644
>> --- a/net/core/rtnetlink.c
>> +++ b/net/core/rtnetlink.c
>> @@ -1777,7 +1777,7 @@ static int rtnl_dellink(struct sk_buff *skb, struct nlmsghdr *nlh)
>>  		return -ENODEV;
>>  
>>  	ops = dev->rtnl_link_ops;
>> -	if (!ops)
>> +	if (!ops || !ops->setup)
>>  		return -EOPNOTSUPP;
>>  
>>  	ops->dellink(dev, &list_kill);
>> @@ -2038,6 +2038,9 @@ replay:
>>  			return -EOPNOTSUPP;
>>  		}
>>  
>> +		if (!ops->setup)
>> +			return -EOPNOTSUPP;
>> +
>>  		if (!ifname[0])
>>  			snprintf(ifname, IFNAMSIZ, "%s%%d", ops->kind);
>>  
>> diff --git a/net/openvswitch/datapath.c b/net/openvswitch/datapath.c
>> index 0d407bc..fe95b6c 100644
>> --- a/net/openvswitch/datapath.c
>> +++ b/net/openvswitch/datapath.c
>> @@ -2054,10 +2054,14 @@ static int __init dp_init(void)
>>  
>>  	pr_info("Open vSwitch switching datapath\n");
>>  
>> -	err = ovs_flow_init();
>> +	err = ovs_internal_dev_rtnl_link_register();
>>  	if (err)
>>  		goto error;
>>  
>> +	err = ovs_flow_init();
>> +	if (err)
>> +		goto error_unreg_rtnl_link;
>> +
>>  	err = ovs_vport_init();
>>  	if (err)
>>  		goto error_flow_exit;
>> @@ -2084,6 +2088,8 @@ error_vport_exit:
>>  	ovs_vport_exit();
>>  error_flow_exit:
>>  	ovs_flow_exit();
>> +error_unreg_rtnl_link:
>> +	ovs_internal_dev_rtnl_link_unregister();
>>  error:
>>  	return err;
>>  }
>> @@ -2096,6 +2102,7 @@ static void dp_cleanup(void)
>>  	rcu_barrier();
>>  	ovs_vport_exit();
>>  	ovs_flow_exit();
>> +	ovs_internal_dev_rtnl_link_unregister();
>>  }
>>  
>>  module_init(dp_init);
>> diff --git a/net/openvswitch/vport-internal_dev.c b/net/openvswitch/vport-internal_dev.c
>> index 789af92..295471a 100644
>> --- a/net/openvswitch/vport-internal_dev.c
>> +++ b/net/openvswitch/vport-internal_dev.c
>> @@ -26,6 +26,7 @@
>>  
>>  #include <net/dst.h>
>>  #include <net/xfrm.h>
>> +#include <net/rtnetlink.h>
>>  
>>  #include "datapath.h"
>>  #include "vport-internal_dev.h"
>> @@ -121,6 +122,10 @@ static const struct net_device_ops internal_dev_netdev_ops = {
>>  	.ndo_get_stats64 = internal_dev_get_stats,
>>  };
>>  
>> +static struct rtnl_link_ops internal_dev_link_ops __read_mostly = {
>> +	.kind = "openvswitch",
>> +};
>> +
>>  static void do_setup(struct net_device *netdev)
>>  {
>>  	ether_setup(netdev);
>> @@ -131,6 +136,7 @@ static void do_setup(struct net_device *netdev)
>>  	netdev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
>>  	netdev->destructor = internal_dev_destructor;
>>  	netdev->ethtool_ops = &internal_dev_ethtool_ops;
>> +	netdev->rtnl_link_ops = &internal_dev_link_ops;
>>  	netdev->tx_queue_len = 0;
>>  
>>  	netdev->features = NETIF_F_LLTX | NETIF_F_SG | NETIF_F_FRAGLIST |
>> @@ -248,3 +254,13 @@ struct vport *ovs_internal_dev_get_vport(struct net_device *netdev)
>>  
>>  	return internal_dev_priv(netdev)->vport;
>>  }
>> +
>> +int ovs_internal_dev_rtnl_link_register(void)
>> +{
>> +	return rtnl_link_register(&internal_dev_link_ops);
>> +}
>> +
>> +void ovs_internal_dev_rtnl_link_unregister(void)
>> +{
>> +	rtnl_link_unregister(&internal_dev_link_ops);
>> +}
>> diff --git a/net/openvswitch/vport-internal_dev.h b/net/openvswitch/vport-internal_dev.h
>> index 9a7d30e..1b179a1 100644
>> --- a/net/openvswitch/vport-internal_dev.h
>> +++ b/net/openvswitch/vport-internal_dev.h
>> @@ -24,5 +24,7 @@
>>  
>>  int ovs_is_internal_dev(const struct net_device *);
>>  struct vport *ovs_internal_dev_get_vport(struct net_device *);
>> +int ovs_internal_dev_rtnl_link_register(void);
>> +void ovs_internal_dev_rtnl_link_unregister(void);
>>  
>>  #endif /* vport-internal_dev.h */