Commit 472681d5 authored by MINOURA Makoto / 箕浦 真's avatar MINOURA Makoto / 箕浦 真 Committed by David S. Miller
Browse files

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: default avatarMinoura Makoto <minoura@valinux.co.jp>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 4c0b6eaf

drivers/net/vxlan.c

+3 −1
Original line number Diff line number Diff line
@@ -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;

			}

net/bridge/br_fdb.c

+10 −5
Original line number Diff line number Diff line
@@ -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,

			err = fdb_fill_info(skb, br, f,

					    NETLINK_CB(cb->skb).portid,

					    cb->nlh->nlmsg_seq,

					    RTM_NEWNEIGH,

					  NLM_F_MULTI) < 0)

					    NLM_F_MULTI);

			if (err < 0) {

				cb->args[1] = err;

				break;

			}

skip:

			++idx;

		}

net/core/rtnetlink.c

+6 −0
Original line number Diff line number Diff line
@@ -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;

	}

net/switchdev/switchdev.c

+4 −1
Original line number Diff line number Diff line
@@ -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);

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