| Message ID | afa206858a88910691bdb917d0956cea3f32f667.1600770261.git.sd@queasysnail.net |
|---|---|
| State | Rejected, archived |
| Delegated to: | Simon Wunderlich |
| Headers | show |
| Series | net: iflink and link-netnsid fixes | expand |
On Thursday, 1 October 2020 09:59:35 CEST Sabrina Dubroca wrote: > device has the same ifindex as its link. Let's use the presence of a > ndo_get_iflink operation, rather than the value it returns, to detect > a device without a link. There wasn't any activity in this patchset since a while, it doesn't apply anymore and the assumptions made here doesn't seem to be reflect the current situation in the kernel. See commit 6c1f41afc1db ("batman-adv: Don't expect inter-netns unique iflink indices"): > But only checking for dev->netdev_ops->ndo_get_iflink is also not an option > because ipoib_get_iflink implements it even when it sometimes returns an > iflink != ifindex and sometimes iflink == ifindex. The caller must > therefore make sure itself to check both netns and iflink + ifindex for > equality. Only when they are equal, a "physical" interface was detected > which should stop the traversal. On the other hand, vxcan_get_iflink can > also return 0 in case there was currently no valid peer. In this case, it > is still necessary to stop. It would would be nice when the situation would be better but the proposed patches don't solve it. So I will mark the two patches as "Rejected" (from "Changes requested") in batadv's patchwork. It is not meant as sign of disapproval of someone working in this area to improve the situation - I just don't want to wait for the v2 [1] anymore. Kind regards, Sven [1] https://lore.kernel.org/all/20201002090703.GD3565727@bistromath.localdomain/
diff --git a/net/batman-adv/hard-interface.c b/net/batman-adv/hard-interface.c index fa06b51c0144..0d87c5d56844 100644 --- a/net/batman-adv/hard-interface.c +++ b/net/batman-adv/hard-interface.c @@ -159,7 +159,7 @@ static bool batadv_is_on_batman_iface(const struct net_device *net_dev) /* no more parents..stop recursion */ if (dev_get_iflink(net_dev) == 0 || - dev_get_iflink(net_dev) == net_dev->ifindex) + !(net_dev->netdev_ops && net_dev->netdev_ops->ndo_get_iflink)) return false; parent_net = batadv_getlink_net(net_dev, net);
BATMAN compares ifindex with dev_get_iflink to detect devices that don't have a parent, but that's wrong, since a device can have the same index as its parent if it's created in a different network namespace: ip netns add main ip netns add peer ip -net main link add dummy0 type dummy # keep ifindex in sync between the namespaces ip -net peer link add eatidx type dummy ip netns exec main batctl if add dummy0 # macsec0 and bat0 have the same ifindex ip -net main link add link bat0 netns peer type macsec ip netns exec peer batctl if add macsec0 That last command would fail if we didn't keep the ifindex in sync between the two namespaces, and should also fail when the macsec0 device has the same ifindex as its link. Let's use the presence of a ndo_get_iflink operation, rather than the value it returns, to detect a device without a link. Fixes: b7eddd0b3950 ("batman-adv: prevent using any virtual device created on batman-adv as hard-interface") Signed-off-by: Sabrina Dubroca <sd@queasysnail.net> --- net/batman-adv/hard-interface.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)