net_sched: return correct value for *notify* functions

It is confusing to directly use return value of netlink_send()/
netlink_unicast() as the return value of *notify*, as it may be not
error at all.

Example: in tc_del_tfilter(), after calling tfilter_del_notify(), it will
goto errout if (err). However, the netlink_send()/netlink_unicast() will
return positive value even for successful case. So it may not call
tcf_chain_tp_remove() and so on to clean up the resource, as a result,
resource is leaked.

It may be easier to only check the return value of tfilter_del_nofiy(),
but it is more clean to correct all related functions.

Co-developed-by: Zengmo Gao <gaozengmo@jd.com>
Signed-off-by: Zhike Wang <wangzhike@jd.com>
Acked-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Zhike Wang 2019-03-11 03:15:54 -07:00 committed by David S. Miller
parent deb6bfabdb
commit 5b5f99b186
2 changed files with 34 additions and 13 deletions

View File

@ -1893,6 +1893,7 @@ static int tfilter_notify(struct net *net, struct sk_buff *oskb,
{
struct sk_buff *skb;
u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
int err = 0;
skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
if (!skb)
@ -1906,10 +1907,14 @@ static int tfilter_notify(struct net *net, struct sk_buff *oskb,
}
if (unicast)
return netlink_unicast(net->rtnl, skb, portid, MSG_DONTWAIT);
return rtnetlink_send(skb, net, portid, RTNLGRP_TC,
err = netlink_unicast(net->rtnl, skb, portid, MSG_DONTWAIT);
else
err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
n->nlmsg_flags & NLM_F_ECHO);
if (err > 0)
err = 0;
return err;
}
static int tfilter_del_notify(struct net *net, struct sk_buff *oskb,
@ -1941,12 +1946,15 @@ static int tfilter_del_notify(struct net *net, struct sk_buff *oskb,
}
if (unicast)
return netlink_unicast(net->rtnl, skb, portid, MSG_DONTWAIT);
err = netlink_unicast(net->rtnl, skb, portid, MSG_DONTWAIT);
else
err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
n->nlmsg_flags & NLM_F_ECHO);
if (err < 0)
NL_SET_ERR_MSG(extack, "Failed to send filter delete notification");
if (err > 0)
err = 0;
return err;
}
@ -2688,6 +2696,7 @@ static int tc_chain_notify(struct tcf_chain *chain, struct sk_buff *oskb,
struct tcf_block *block = chain->block;
struct net *net = block->net;
struct sk_buff *skb;
int err = 0;
skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
if (!skb)
@ -2701,9 +2710,14 @@ static int tc_chain_notify(struct tcf_chain *chain, struct sk_buff *oskb,
}
if (unicast)
return netlink_unicast(net->rtnl, skb, portid, MSG_DONTWAIT);
err = netlink_unicast(net->rtnl, skb, portid, MSG_DONTWAIT);
else
err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
flags & NLM_F_ECHO);
return rtnetlink_send(skb, net, portid, RTNLGRP_TC, flags & NLM_F_ECHO);
if (err > 0)
err = 0;
return err;
}
static int tc_chain_notify_delete(const struct tcf_proto_ops *tmplt_ops,

View File

@ -1824,6 +1824,7 @@ static int tclass_notify(struct net *net, struct sk_buff *oskb,
{
struct sk_buff *skb;
u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
int err = 0;
skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
if (!skb)
@ -1834,8 +1835,11 @@ static int tclass_notify(struct net *net, struct sk_buff *oskb,
return -EINVAL;
}
return rtnetlink_send(skb, net, portid, RTNLGRP_TC,
err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
n->nlmsg_flags & NLM_F_ECHO);
if (err > 0)
err = 0;
return err;
}
static int tclass_del_notify(struct net *net,
@ -1866,8 +1870,11 @@ static int tclass_del_notify(struct net *net,
return err;
}
return rtnetlink_send(skb, net, portid, RTNLGRP_TC,
err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
n->nlmsg_flags & NLM_F_ECHO);
if (err > 0)
err = 0;
return err;
}
#ifdef CONFIG_NET_CLS