Johannes Berg <johannes@xxxxxxxxxxxxxxxx> writes:
> This makes wireless extensions netns aware.
>
> Signed-off-by: Johannes Berg <johannes@xxxxxxxxxxxxxxxx>
> ---
> Is this ok, or is this racy? I guess what I'm asking is -- will
> for_each_net() stop iterating over a netns that is going away before the
> pernet exit op is called? If yes, this should be fine.
for_each_net requires the rtnl_lock or the net_mutex to be safe.
You aren't taking either so your code is racy.
A dying network namespace will be removed from the net_namespace_list
(aka for_each_net) before the per net exit methods are called.
Is grabbing the rtnl_lock safe in your workqueue and is that something
we want to do?
Eric
> include/net/net_namespace.h | 3 +++
> net/wireless/wext.c | 30 ++++++++++++++++++++++--------
> 2 files changed, 25 insertions(+), 8 deletions(-)
>
> --- wireless-testing.orig/include/net/net_namespace.h 2009-06-17 20:20:47.000000000 +0200
> +++ wireless-testing/include/net/net_namespace.h 2009-06-17 20:20:51.000000000 +0200
> @@ -78,6 +78,9 @@ struct net {
> #ifdef CONFIG_XFRM
> struct netns_xfrm xfrm;
> #endif
> +#ifdef CONFIG_WIRELESS_EXT
> + struct sk_buff_head wext_nlevents;
> +#endif
> struct net_generic *gen;
> };
>
> --- wireless-testing.orig/net/wireless/wext.c 2009-06-17 20:20:47.000000000 +0200
> +++ wireless-testing/net/wireless/wext.c 2009-06-17 20:20:51.000000000 +0200
> @@ -1273,11 +1273,25 @@ int compat_wext_handle_ioctl(struct net
> * Jean II
> */
>
> -static struct sk_buff_head wireless_nlevent_queue;
> +static int __net_init wext_pernet_init(struct net *net)
> +{
> + skb_queue_head_init(&net->wext_nlevents);
> + return 0;
> +}
> +
> +static void __net_exit wext_pernet_exit(struct net *net)
> +{
> + skb_queue_purge(&net->wext_nlevents);
> +}
> +
> +static struct pernet_operations wext_pernet_ops = {
> + .init = wext_pernet_init,
> + .exit = wext_pernet_exit,
> +};
>
> static int __init wireless_nlevent_init(void)
> {
> - skb_queue_head_init(&wireless_nlevent_queue);
> + return register_pernet_subsys(&wext_pernet_ops);
> return 0;
> }
>
> @@ -1286,9 +1300,12 @@ subsys_initcall(wireless_nlevent_init);
> static void wireless_nlevent_process(unsigned long data)
> {
> struct sk_buff *skb;
> + struct net *net;
>
> - while ((skb = skb_dequeue(&wireless_nlevent_queue)))
> - rtnl_notify(skb, &init_net, 0, RTNLGRP_LINK, NULL, GFP_ATOMIC);
> + for_each_net(net)
> + while ((skb = skb_dequeue(&net->wext_nlevents)))
> + rtnl_notify(skb, net, 0, RTNLGRP_LINK, NULL,
> + GFP_ATOMIC);
> }
>
> static DECLARE_TASKLET(wireless_nlevent_tasklet, wireless_nlevent_process, 0);
> @@ -1341,9 +1358,6 @@ static void rtmsg_iwinfo(struct net_devi
> struct sk_buff *skb;
> int err;
>
> - if (!net_eq(dev_net(dev), &init_net))
> - return;
> -
> skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC);
> if (!skb)
> return;
> @@ -1356,7 +1370,7 @@ static void rtmsg_iwinfo(struct net_devi
> }
>
> NETLINK_CB(skb).dst_group = RTNLGRP_LINK;
> - skb_queue_tail(&wireless_nlevent_queue, skb);
> + skb_queue_tail(&dev_net(dev)->wext_nlevents, skb);
> tasklet_schedule(&wireless_nlevent_tasklet);
> }
>
>
>
> --
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