From: Tom Gundersen <teg@jklm.no>
To: netdev@vger.kernel.org
Cc: linux-kernel@vger.kernel.org,
John Fastabend <john.r.fastabend@intel.com>,
Thomas Graf <tgraf@suug.ch>,
Nicolas Dichtel <nicolas.dichtel@6wind.com>,
Vlad Yasevich <vyasevich@gmail.com>, Tom Gundersen <teg@jklm.no>,
Marcel Holtmann <marcel@holtmann.org>,
"David S. Miller" <davem@davemloft.net>
Subject: [PATCH] rtnetlink: return the newly created link in response to newlink
Date: Thu, 30 Jan 2014 14:05:44 +0100 [thread overview]
Message-ID: <1391087144-24490-1-git-send-email-teg@jklm.no> (raw)
Userspace needs to reliably know the ifindex of the netdevs it creates,
as we cannot rely on the ifname staying unchanged.
Earlier, a simlpe NLMSG_ERROR would be returned, but this returns the
corresponding RTM_NEWLINK on success instead.
Signed-off-by: Tom Gundersen <teg@jklm.no>
Cc: Marcel Holtmann <marcel@holtmann.org>
Cc: David S. Miller <davem@davemloft.net>
---
net/core/rtnetlink.c | 100 ++++++++++++++++++++++++++-------------------------
1 file changed, 52 insertions(+), 48 deletions(-)
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index cf67144..31c1322 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -1725,6 +1725,54 @@ static int rtnl_group_changelink(struct net *net, int group,
return 0;
}
+static int rtnl_getlink(struct sk_buff *skb, struct nlmsghdr* nlh)
+{
+ struct net *net = sock_net(skb->sk);
+ struct ifinfomsg *ifm;
+ char ifname[IFNAMSIZ];
+ struct nlattr *tb[IFLA_MAX+1];
+ struct net_device *dev = NULL;
+ struct sk_buff *nskb;
+ int err;
+ u32 ext_filter_mask = 0;
+
+ err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFLA_MAX, ifla_policy);
+ if (err < 0)
+ return err;
+
+ if (tb[IFLA_IFNAME])
+ nla_strlcpy(ifname, tb[IFLA_IFNAME], IFNAMSIZ);
+
+ if (tb[IFLA_EXT_MASK])
+ ext_filter_mask = nla_get_u32(tb[IFLA_EXT_MASK]);
+
+ ifm = nlmsg_data(nlh);
+ if (ifm->ifi_index > 0)
+ dev = __dev_get_by_index(net, ifm->ifi_index);
+ else if (tb[IFLA_IFNAME])
+ dev = __dev_get_by_name(net, ifname);
+ else
+ return -EINVAL;
+
+ if (dev == NULL)
+ return -ENODEV;
+
+ nskb = nlmsg_new(if_nlmsg_size(dev, ext_filter_mask), GFP_KERNEL);
+ if (nskb == NULL)
+ return -ENOBUFS;
+
+ err = rtnl_fill_ifinfo(nskb, dev, RTM_NEWLINK, NETLINK_CB(skb).portid,
+ nlh->nlmsg_seq, 0, 0, ext_filter_mask);
+ if (err < 0) {
+ /* -EMSGSIZE implies BUG in if_nlmsg_size */
+ WARN_ON(err == -EMSGSIZE);
+ kfree_skb(nskb);
+ } else
+ err = rtnl_unicast(nskb, net, NETLINK_CB(skb).portid);
+
+ return err;
+}
+
static int rtnl_newlink(struct sk_buff *skb, struct nlmsghdr *nlh)
{
struct net *net = sock_net(skb->sk);
@@ -1871,63 +1919,19 @@ replay:
goto out;
}
+ ifm->ifi_index = dev->ifindex;
+
err = rtnl_configure_link(dev, ifm);
if (err < 0)
unregister_netdevice(dev);
+ else
+ rtnl_getlink(skb, nlh);
out:
put_net(dest_net);
return err;
}
}
-static int rtnl_getlink(struct sk_buff *skb, struct nlmsghdr* nlh)
-{
- struct net *net = sock_net(skb->sk);
- struct ifinfomsg *ifm;
- char ifname[IFNAMSIZ];
- struct nlattr *tb[IFLA_MAX+1];
- struct net_device *dev = NULL;
- struct sk_buff *nskb;
- int err;
- u32 ext_filter_mask = 0;
-
- err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFLA_MAX, ifla_policy);
- if (err < 0)
- return err;
-
- if (tb[IFLA_IFNAME])
- nla_strlcpy(ifname, tb[IFLA_IFNAME], IFNAMSIZ);
-
- if (tb[IFLA_EXT_MASK])
- ext_filter_mask = nla_get_u32(tb[IFLA_EXT_MASK]);
-
- ifm = nlmsg_data(nlh);
- if (ifm->ifi_index > 0)
- dev = __dev_get_by_index(net, ifm->ifi_index);
- else if (tb[IFLA_IFNAME])
- dev = __dev_get_by_name(net, ifname);
- else
- return -EINVAL;
-
- if (dev == NULL)
- return -ENODEV;
-
- nskb = nlmsg_new(if_nlmsg_size(dev, ext_filter_mask), GFP_KERNEL);
- if (nskb == NULL)
- return -ENOBUFS;
-
- err = rtnl_fill_ifinfo(nskb, dev, RTM_NEWLINK, NETLINK_CB(skb).portid,
- nlh->nlmsg_seq, 0, 0, ext_filter_mask);
- if (err < 0) {
- /* -EMSGSIZE implies BUG in if_nlmsg_size */
- WARN_ON(err == -EMSGSIZE);
- kfree_skb(nskb);
- } else
- err = rtnl_unicast(nskb, net, NETLINK_CB(skb).portid);
-
- return err;
-}
-
static u16 rtnl_calcit(struct sk_buff *skb, struct nlmsghdr *nlh)
{
struct net *net = sock_net(skb->sk);
--
1.8.5.3
next reply other threads:[~2014-01-30 13:05 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-01-30 13:05 Tom Gundersen [this message]
2014-01-30 14:27 ` [PATCH] rtnetlink: return the newly created link in response to newlink Thomas Graf
2014-01-31 0:57 ` Tom Gundersen
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