From 472681d57a5dde7c6d16b05469be57f1c4ed9d99 Mon Sep 17 00:00:00 2001 From: =?utf8?q?MINOURA=20Makoto=20/=20=E7=AE=95=E6=B5=A6=20=E7=9C=9F?= Date: Thu, 25 Feb 2016 14:20:48 +0900 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 Signed-off-by: David S. Miller --- 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 e6944b29588e..b601139a145a 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 82e3e9705017..dcea4f4c62b3 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 d735e854f916..8261d95dd846 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 47f7da58a7f0..8b5833c1ff2e 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); -- 2.20.1