[PATCH 4.19 215/243] xfrm interface: fix management of phydev

Greg Kroah-Hartman
2019-12-11T15:25:09Z

From: Nicolas Dichtel <nicolas.dichtel@6wind.com>

commit 22d6552f827ef76ade3edf6bbb3f05048a0a7d8b upstream.

With the current implementation, phydev cannot be removed:

$ ip link add dummy type dummy
$ ip link add xfrm1 type xfrm dev dummy if_id 1
$ ip l d dummy
kernel:[77938.465445] unregister_netdevice: waiting for dummy to become free. Usage count = 1

Manage it like in ip tunnels, ie just keep the ifindex. Not that the side
effect, is that the phydev is now optional.

Fixes: f203b76d7809 ("xfrm: Add virtual xfrm interfaces")
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Tested-by: Julien Floret <julien.floret@6wind.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
include/net/xfrm.h | 1 -
net/xfrm/xfrm_interface.c | 34 ++++++++++++++++++----------------
2 files changed, 18 insertions(+), 17 deletions(-)

--- a/include/net/xfrm.h
+++ b/include/net/xfrm.h
@@ -1062,7 +1062,6 @@ struct xfrm_if_parms {
struct xfrm_if {
struct xfrm_if __rcu *next; /* next interface in list */
struct net_device *dev; /* virtual device associated with interface */
- struct net_device *phydev; /* physical device */
struct net *net; /* netns for packet i/o */
struct xfrm_if_parms p; /* interface parms */

--- a/net/xfrm/xfrm_interface.c
+++ b/net/xfrm/xfrm_interface.c
@@ -177,7 +177,6 @@ static void xfrmi_dev_uninit(struct net_
struct xfrmi_net *xfrmn = net_generic(xi->net, xfrmi_net_id);

xfrmi_unlink(xfrmn, xi);
- dev_put(xi->phydev);
dev_put(dev);
}

@@ -364,7 +363,7 @@ static netdev_tx_t xfrmi_xmit(struct sk_
goto tx_err;
}

- fl.flowi_oif = xi->phydev->ifindex;
+ fl.flowi_oif = xi->p.link;

ret = xfrmi_xmit2(skb, dev, &fl);
if (ret < 0)
@@ -553,7 +552,7 @@ static int xfrmi_get_iflink(const struct
{
struct xfrm_if *xi = netdev_priv(dev);

- return xi->phydev->ifindex;
+ return xi->p.link;
}

@@ -579,12 +578,14 @@ static void xfrmi_dev_setup(struct net_d
dev->needs_free_netdev = true;
dev->priv_destructor = xfrmi_dev_free;
netif_keep_dst(dev);
+
+ eth_broadcast_addr(dev->broadcast);
}

static int xfrmi_dev_init(struct net_device *dev)
{
struct xfrm_if *xi = netdev_priv(dev);
- struct net_device *phydev = xi->phydev;
+ struct net_device *phydev = __dev_get_by_index(xi->net, xi->p.link);
int err;

dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
@@ -599,13 +600,19 @@ static int xfrmi_dev_init(struct net_dev

dev->features |= NETIF_F_LLTX;

- dev->needed_headroom = phydev->needed_headroom;
- dev->needed_tailroom = phydev->needed_tailroom;
-
- if (is_zero_ether_addr(dev->dev_addr))
- eth_hw_addr_inherit(dev, phydev);
- if (is_zero_ether_addr(dev->broadcast))
- memcpy(dev->broadcast, phydev->broadcast, dev->addr_len);
+ if (phydev) {
+ dev->needed_headroom = phydev->needed_headroom;
+ dev->needed_tailroom = phydev->needed_tailroom;
+
+ if (is_zero_ether_addr(dev->dev_addr))
+ eth_hw_addr_inherit(dev, phydev);
+ if (is_zero_ether_addr(dev->broadcast))
+ memcpy(dev->broadcast, phydev->broadcast,
+ dev->addr_len);
+ } else {
+ eth_hw_addr_random(dev);
+ eth_broadcast_addr(dev->broadcast);
+ }

return 0;
}
@@ -655,13 +662,8 @@ static int xfrmi_newlink(struct net *src
xi->p = p;
xi->net = net;
xi->dev = dev;
- xi->phydev = dev_get_by_index(net, p.link);
- if (!xi->phydev)
- return -ENODEV;

err = xfrmi_create(dev);
- if (err < 0)
- dev_put(xi->phydev);
return err;
}