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Message-ID: <kk537sh1i33.fsf@brer.local.valinux.co.jp>
Date: Thu, 25 Feb 2016 14:20:48 +0900
From: MINOURA Makoto / 箕浦 真
<minoura@...inux.co.jp>
To: netdev@...r.kernel.org
Subject: [PATCH] net: ndo_fdb_dump should report -EMSGSIZE to rtnl_fdb_dump.
When the send skbuff reaches the end, nlmsg_put and friends returns
-EMSGSIZE but it is silently thrown away in ndo_fdb_dump. It is called
within a for_each_netdev loop and the first fdb entry of a following
netdev could fit in the remaining skbuff. This breaks the mechanism
of cb->args[0] and idx to keep track of the entries that are already
dumped, which results missing entries in bridge fdb show command.
Signed-off-by: Minoura Makoto <minoura@...inux.co.jp>
---
drivers/net/vxlan.c | 4 +++-
net/bridge/br_fdb.c | 15 ++++++++++-----
net/core/rtnetlink.c | 6 ++++++
net/switchdev/switchdev.c | 5 ++++-
4 files changed, 23 insertions(+), 7 deletions(-)
diff --git a/drivers/net/vxlan.c b/drivers/net/vxlan.c
index a31cd95..3b11518 100644
--- a/drivers/net/vxlan.c
+++ b/drivers/net/vxlan.c
@@ -931,8 +931,10 @@ static int vxlan_fdb_dump(struct sk_buff *skb, struct netlink_callback *cb,
cb->nlh->nlmsg_seq,
RTM_NEWNEIGH,
NLM_F_MULTI, rd);
- if (err < 0)
+ if (err < 0) {
+ cb->args[1] = err;
goto out;
+ }
skip:
++idx;
}
diff --git a/net/bridge/br_fdb.c b/net/bridge/br_fdb.c
index 82e3e97..dcea4f4 100644
--- a/net/bridge/br_fdb.c
+++ b/net/bridge/br_fdb.c
@@ -723,6 +723,8 @@ int br_fdb_dump(struct sk_buff *skb,
struct net_bridge_fdb_entry *f;
hlist_for_each_entry_rcu(f, &br->hash[i], hlist) {
+ int err;
+
if (idx < cb->args[0])
goto skip;
@@ -741,12 +743,15 @@ int br_fdb_dump(struct sk_buff *skb,
if (!filter_dev && f->dst)
goto skip;
- if (fdb_fill_info(skb, br, f,
- NETLINK_CB(cb->skb).portid,
- cb->nlh->nlmsg_seq,
- RTM_NEWNEIGH,
- NLM_F_MULTI) < 0)
+ err = fdb_fill_info(skb, br, f,
+ NETLINK_CB(cb->skb).portid,
+ cb->nlh->nlmsg_seq,
+ RTM_NEWNEIGH,
+ NLM_F_MULTI);
+ if (err < 0) {
+ cb->args[1] = err;
break;
+ }
skip:
++idx;
}
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index d735e85..8261d95 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -2911,6 +2911,7 @@ int ndo_dflt_fdb_dump(struct sk_buff *skb,
nlmsg_populate_fdb(skb, cb, dev, &idx, &dev->mc);
out:
netif_addr_unlock_bh(dev);
+ cb->args[1] = err;
return idx;
}
EXPORT_SYMBOL(ndo_dflt_fdb_dump);
@@ -2944,6 +2945,7 @@ static int rtnl_fdb_dump(struct sk_buff *skb, struct netlink_callback *cb)
ops = br_dev->netdev_ops;
}
+ cb->args[1] = 0;
for_each_netdev(net, dev) {
if (brport_idx && (dev->ifindex != brport_idx))
continue;
@@ -2971,12 +2973,16 @@ static int rtnl_fdb_dump(struct sk_buff *skb, struct netlink_callback *cb)
idx = cops->ndo_fdb_dump(skb, cb, br_dev, dev,
idx);
}
+ if (cb->args[1] == -EMSGSIZE)
+ break;
if (dev->netdev_ops->ndo_fdb_dump)
idx = dev->netdev_ops->ndo_fdb_dump(skb, cb, dev, NULL,
idx);
else
idx = ndo_dflt_fdb_dump(skb, cb, dev, NULL, idx);
+ if (cb->args[1] == -EMSGSIZE)
+ break;
cops = NULL;
}
diff --git a/net/switchdev/switchdev.c b/net/switchdev/switchdev.c
index 47f7da5..8b5833c 100644
--- a/net/switchdev/switchdev.c
+++ b/net/switchdev/switchdev.c
@@ -1093,8 +1093,11 @@ int switchdev_port_fdb_dump(struct sk_buff *skb, struct netlink_callback *cb,
.cb = cb,
.idx = idx,
};
+ int err;
- switchdev_port_obj_dump(dev, &dump.fdb.obj, switchdev_port_fdb_dump_cb);
+ err = switchdev_port_obj_dump(dev, &dump.fdb.obj,
+ switchdev_port_fdb_dump_cb);
+ cb->args[1] = err;
return dump.idx;
}
EXPORT_SYMBOL_GPL(switchdev_port_fdb_dump);
--
2.5.0
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