Re: [PATCH net v3 10/11] vxlan: add adjacent link to limit depth level
From: Jakub Kicinski <hidden>
Date: 2019-09-20 23:48:25
On Mon, 16 Sep 2019 22:48:01 +0900, Taehee Yoo wrote:
Current vxlan code doesn't limit the number of nested devices. Nested devices would be handled recursively and this routine needs huge stack memory. So, unlimited nested devices could make stack overflow. In order to fix this issue, this patch adds adjacent links. The adjacent link APIs internally check the depth level.
Fixes: acaf4e70997f ("net: vxlan: when lower dev unregisters remove vxlan dev as well")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>Minor nit picks here, I hope you don't mind.
quoted hunk ↗ jump to hunk
diff --git a/drivers/net/vxlan.c b/drivers/net/vxlan.c index 3d9bcc957f7d..0d5c8d22d8a4 100644 --- a/drivers/net/vxlan.c +++ b/drivers/net/vxlan.c@@ -3567,6 +3567,8 @@ static int __vxlan_dev_create(struct net *net, struct net_device *dev, struct vxlan_net *vn = net_generic(net, vxlan_net_id); struct vxlan_dev *vxlan = netdev_priv(dev); struct vxlan_fdb *f = NULL; + struct net_device *remote_dev = NULL; + struct vxlan_rdst *dst = &vxlan->default_dst;
Especially in places where reverse christmas tree variable ordering is adhered to, could you please preserve it? That'd mean: struct vxlan_net *vn = net_generic(net, vxlan_net_id); struct vxlan_dev *vxlan = netdev_priv(dev); struct net_device *remote_dev = NULL; struct vxlan_fdb *f = NULL; bool unregister = false; struct vxlan_rdst *dst; int err; dst = &vxlan->default_dst; here.
quoted hunk ↗ jump to hunk
bool unregister = false; int err;@@ -3577,14 +3579,14 @@ static int __vxlan_dev_create(struct net *net, struct net_device *dev, dev->ethtool_ops = &vxlan_ethtool_ops; /* create an fdb entry for a valid default destination */ - if (!vxlan_addr_any(&vxlan->default_dst.remote_ip)) { + if (!vxlan_addr_any(&dst->remote_ip)) { err = vxlan_fdb_create(vxlan, all_zeros_mac, - &vxlan->default_dst.remote_ip, + &dst->remote_ip, NUD_REACHABLE | NUD_PERMANENT, vxlan->cfg.dst_port, - vxlan->default_dst.remote_vni, - vxlan->default_dst.remote_vni, - vxlan->default_dst.remote_ifindex, + dst->remote_vni, + dst->remote_vni, + dst->remote_ifindex, NTF_SELF, &f); if (err) return err;@@ -3595,26 +3597,43 @@ static int __vxlan_dev_create(struct net *net, struct net_device *dev, goto errout; unregister = true; + if (dst->remote_ifindex) { + remote_dev = __dev_get_by_index(net, dst->remote_ifindex); + if (!remote_dev) + goto errout; + + err = netdev_upper_dev_link(remote_dev, dev, extack); + if (err) + goto errout; + } + err = rtnl_configure_link(dev, NULL); if (err) - goto errout; + goto unlink; if (f) { - vxlan_fdb_insert(vxlan, all_zeros_mac, - vxlan->default_dst.remote_vni, f); + vxlan_fdb_insert(vxlan, all_zeros_mac, dst->remote_vni, f); /* notify default fdb entry */ err = vxlan_fdb_notify(vxlan, f, first_remote_rtnl(f), RTM_NEWNEIGH, true, extack); if (err) { vxlan_fdb_destroy(vxlan, f, false, false); + if (remote_dev) + netdev_upper_dev_unlink(remote_dev, dev); goto unregister; } } list_add(&vxlan->next, &vn->vxlan_list); + if (remote_dev) { + dst->remote_dev = remote_dev; + dev_hold(remote_dev); + } return 0; - +unlink: + if (remote_dev) + netdev_upper_dev_unlink(remote_dev, dev); errout: /* unregister_netdevice() destroys the default FDB entry with deletion * notification. But the addition notification was not sent yet, so@@ -3936,6 +3955,8 @@ static int vxlan_changelink(struct net_device *dev, struct nlattr *tb[], struct net_device *lowerdev; struct vxlan_config conf; int err; + bool linked = false; + bool disabled = false;
Same here.
quoted hunk ↗ jump to hunk
err = vxlan_nl2conf(tb, data, dev, &conf, true, extack); if (err)@@ -3946,6 +3967,16 @@ static int vxlan_changelink(struct net_device *dev, struct nlattr *tb[], if (err) return err; + if (lowerdev) { + if (dst->remote_dev && lowerdev != dst->remote_dev) { + netdev_adjacent_dev_disable(dst->remote_dev, dev); + disabled = true; + } + err = netdev_upper_dev_link(lowerdev, dev, extack); + if (err) + goto err;
would you mind naming the label errout? there is an err variable, and other places in this file use errout
quoted hunk ↗ jump to hunk
+ linked = true; + } /* handle default dst entry */ if (!vxlan_addr_equal(&conf.remote_ip, &dst->remote_ip)) { u32 hash_index = fdb_head_index(vxlan, all_zeros_mac, conf.vni);@@ -3962,7 +3993,7 @@ static int vxlan_changelink(struct net_device *dev, struct nlattr *tb[], NTF_SELF, true, extack); if (err) { spin_unlock_bh(&vxlan->hash_lock[hash_index]); - return err; + goto err; } } if (!vxlan_addr_any(&dst->remote_ip))@@ -3979,8 +4010,24 @@ static int vxlan_changelink(struct net_device *dev, struct nlattr *tb[], if (conf.age_interval != vxlan->cfg.age_interval) mod_timer(&vxlan->age_timer, jiffies); + if (disabled) { + netdev_adjacent_dev_enable(dst->remote_dev, dev); + netdev_upper_dev_unlink(dst->remote_dev, dev); + dev_put(dst->remote_dev); + } + if (linked) { + dst->remote_dev = lowerdev; + dev_hold(dst->remote_dev); + } + vxlan_config_apply(dev, &conf, lowerdev, vxlan->net, true); return 0; +err: + if (linked) + netdev_upper_dev_unlink(lowerdev, dev); + if (disabled) + netdev_adjacent_dev_enable(dst->remote_dev, dev); + return err; } static void vxlan_dellink(struct net_device *dev, struct list_head *head)@@ -3991,6 +4038,10 @@ static void vxlan_dellink(struct net_device *dev, struct list_head *head) list_del(&vxlan->next); unregister_netdevice_queue(dev, head); + if (vxlan->default_dst.remote_dev) { + netdev_upper_dev_unlink(vxlan->default_dst.remote_dev, dev); + dev_put(vxlan->default_dst.remote_dev); + } } static size_t vxlan_get_size(const struct net_device *dev)diff --git a/include/net/vxlan.h b/include/net/vxlan.h index dc1583a1fb8a..08e237d7aa73 100644 --- a/include/net/vxlan.h +++ b/include/net/vxlan.h@@ -197,6 +197,7 @@ struct vxlan_rdst { u8 offloaded:1; __be32 remote_vni; u32 remote_ifindex; + struct net_device *remote_dev; struct list_head list; struct rcu_head rcu; struct dst_cache dst_cache;