net: rtnetlink: rtnl_fill_statsinfo(): Permit non-EMSGSIZE error returns

Obtaining stats for the IFLA_STATS_LINK_OFFLOAD_XSTATS nest involves a HW
access, and can fail for more reasons than just netlink message size
exhaustion. Therefore do not always return -EMSGSIZE on the failure path,
but respect the error code provided by the callee. Set the error explicitly
where it is reasonable to assume -EMSGSIZE as the failure reason.

Signed-off-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Petr Machata 2022-03-02 18:31:19 +02:00 committed by David S. Miller
parent 05415bccbb
commit 216e690631

View File

@ -5177,8 +5177,10 @@ static int rtnl_fill_statsinfo(struct sk_buff *skb, struct net_device *dev,
attr = nla_reserve_64bit(skb, IFLA_STATS_LINK_64,
sizeof(struct rtnl_link_stats64),
IFLA_STATS_UNSPEC);
if (!attr)
if (!attr) {
err = -EMSGSIZE;
goto nla_put_failure;
}
sp = nla_data(attr);
dev_get_stats(dev, sp);
@ -5191,8 +5193,10 @@ static int rtnl_fill_statsinfo(struct sk_buff *skb, struct net_device *dev,
*idxattr = IFLA_STATS_LINK_XSTATS;
attr = nla_nest_start_noflag(skb,
IFLA_STATS_LINK_XSTATS);
if (!attr)
if (!attr) {
err = -EMSGSIZE;
goto nla_put_failure;
}
err = ops->fill_linkxstats(skb, dev, prividx, *idxattr);
nla_nest_end(skb, attr);
@ -5214,8 +5218,10 @@ static int rtnl_fill_statsinfo(struct sk_buff *skb, struct net_device *dev,
*idxattr = IFLA_STATS_LINK_XSTATS_SLAVE;
attr = nla_nest_start_noflag(skb,
IFLA_STATS_LINK_XSTATS_SLAVE);
if (!attr)
if (!attr) {
err = -EMSGSIZE;
goto nla_put_failure;
}
err = ops->fill_linkxstats(skb, dev, prividx, *idxattr);
nla_nest_end(skb, attr);
@ -5233,8 +5239,10 @@ static int rtnl_fill_statsinfo(struct sk_buff *skb, struct net_device *dev,
*idxattr = IFLA_STATS_LINK_OFFLOAD_XSTATS;
attr = nla_nest_start_noflag(skb,
IFLA_STATS_LINK_OFFLOAD_XSTATS);
if (!attr)
if (!attr) {
err = -EMSGSIZE;
goto nla_put_failure;
}
err = rtnl_offload_xstats_fill(skb, dev, prividx,
off_filter_mask, extack);
@ -5253,8 +5261,10 @@ static int rtnl_fill_statsinfo(struct sk_buff *skb, struct net_device *dev,
*idxattr = IFLA_STATS_AF_SPEC;
attr = nla_nest_start_noflag(skb, IFLA_STATS_AF_SPEC);
if (!attr)
if (!attr) {
err = -EMSGSIZE;
goto nla_put_failure;
}
rcu_read_lock();
list_for_each_entry_rcu(af_ops, &rtnl_af_ops, list) {
@ -5298,7 +5308,7 @@ nla_put_failure:
else
nlmsg_end(skb, nlh);
return -EMSGSIZE;
return err;
}
static size_t if_nlmsg_stats_size(const struct net_device *dev,