From 070cbf5be7774dcf0ceca081c7321c6f2ae833a4 Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Mon, 16 Oct 2017 15:44:35 +0200 Subject: [PATCH] rtnetlink: place link af dump into own helper next patch will rcu-ify rtnl af_ops, i.e. allow af_ops lookup and function calls with rcu read lock held instead of rtnl mutex. Signed-off-by: Florian Westphal Signed-off-by: David S. Miller --- net/core/rtnetlink.c | 72 ++++++++++++++++++++++++++------------------ 1 file changed, 42 insertions(+), 30 deletions(-) diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c index 6a09f3d575af..a49cad25e577 100644 --- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c @@ -1382,6 +1382,47 @@ static int rtnl_fill_link_netnsid(struct sk_buff *skb, return 0; } +static int rtnl_fill_link_af(struct sk_buff *skb, + const struct net_device *dev, + u32 ext_filter_mask) +{ + const struct rtnl_af_ops *af_ops; + struct nlattr *af_spec; + + af_spec = nla_nest_start(skb, IFLA_AF_SPEC); + if (!af_spec) + return -EMSGSIZE; + + list_for_each_entry(af_ops, &rtnl_af_ops, list) { + struct nlattr *af; + int err; + + if (!af_ops->fill_link_af) + continue; + + af = nla_nest_start(skb, af_ops->family); + if (!af) + return -EMSGSIZE; + + err = af_ops->fill_link_af(skb, dev, ext_filter_mask); + /* + * Caller may return ENODATA to indicate that there + * was no data to be dumped. This is not an error, it + * means we should trim the attribute header and + * continue. + */ + if (err == -ENODATA) + nla_nest_cancel(skb, af); + else if (err < 0) + return -EMSGSIZE; + + nla_nest_end(skb, af); + } + + nla_nest_end(skb, af_spec); + return 0; +} + static int rtnl_fill_ifinfo(struct sk_buff *skb, struct net_device *dev, int type, u32 pid, u32 seq, u32 change, unsigned int flags, u32 ext_filter_mask, @@ -1389,8 +1430,6 @@ static int rtnl_fill_ifinfo(struct sk_buff *skb, struct net_device *dev, { struct ifinfomsg *ifm; struct nlmsghdr *nlh; - struct nlattr *af_spec; - struct rtnl_af_ops *af_ops; ASSERT_RTNL(); nlh = nlmsg_put(skb, pid, seq, type, sizeof(*ifm), flags); @@ -1477,36 +1516,9 @@ static int rtnl_fill_ifinfo(struct sk_buff *skb, struct net_device *dev, nla_put_s32(skb, IFLA_NEW_NETNSID, *new_nsid) < 0) goto nla_put_failure; - if (!(af_spec = nla_nest_start(skb, IFLA_AF_SPEC))) + if (rtnl_fill_link_af(skb, dev, ext_filter_mask)) goto nla_put_failure; - list_for_each_entry(af_ops, &rtnl_af_ops, list) { - if (af_ops->fill_link_af) { - struct nlattr *af; - int err; - - if (!(af = nla_nest_start(skb, af_ops->family))) - goto nla_put_failure; - - err = af_ops->fill_link_af(skb, dev, ext_filter_mask); - - /* - * Caller may return ENODATA to indicate that there - * was no data to be dumped. This is not an error, it - * means we should trim the attribute header and - * continue. - */ - if (err == -ENODATA) - nla_nest_cancel(skb, af); - else if (err < 0) - goto nla_put_failure; - - nla_nest_end(skb, af); - } - } - - nla_nest_end(skb, af_spec); - nlmsg_end(skb, nlh); return 0; -- 2.45.2