Re: [PATCH 2/3] gtp: select netns based on NL attribute

This permits a split namespace setup where the GTP transport sockets are in one namespace the gtp tunnel interface is in another namespace. The target namespece is selected by the new GTPA_NET_NS_FD NL attributes. It fall back to the netns of the GTP-U sockets if the NL attr is not present. Signed-off-by: Andreas Schultz &lt;aschultz(a)tpip.net&gt; --- gtp.c | 35 +++++++++++++++++++++++++++++++---- gtp_nl.h | 1 + 2 files changed, 32 insertions(+), 4 deletions(-) diff --git a/gtp.c b/gtp.c index cbe2da1..0a45f53 100644 --- a/gtp.c +++ b/gtp.c @@ -740,7 +740,7 @@ static int gtp_encap_enable(struct net_device *dev, struct gtp_instance *gti, static int gtp_newlink(struct net *src_net, struct net_device *dev, struct nlattr *tb[], struct nlattr *data[]) { - struct gtp_net *gn = net_generic(src_net, gtp_net_id); + struct gtp_net *gn; struct net_device *real_dev; struct gtp_instance *gti; int hashsize, err, fd0, fd1; @@ -780,6 +780,7 @@ static int gtp_newlink(struct net *src_net, struct net_device *dev, if (err < 0) goto err1; + gn = net_generic(dev_net(dev), gtp_net_id); list_add_rcu(&gti->list, &gn->gtp_instance_list); netdev_dbg(dev, "registered new interface\n"); @@ -847,6 +848,19 @@ static struct rtnl_link_ops gtp_link_ops __read_mostly = { .fill_info = gtp_fill_info, }; +static struct net *gtp_genl_get_net(struct net *src_net, struct nlattr *tb[]) +{ + struct net *net; + /* Examine the link attributes and figure out which + * network namespace we are talking about. + */ + if (tb[GTPA_NET_NS_FD]) + net = get_net_ns_by_fd(nla_get_u32(tb[GTPA_NET_NS_FD])); + else + net = get_net(src_net); + return net; +} + static int gtp_hashtable_new(struct gtp_instance *gti, int hsize) { int i; @@ -1065,7 +1079,7 @@ static int ipv4_pdp_add(struct net_device *dev, struct genl_info *info) static int gtp_genl_tunnel_new(struct sk_buff *skb, struct genl_info *info) { - struct net *net = sock_net(skb->sk); + struct net *net; struct net_device *dev; if (!info->attrs[GTPA_VERSION] || @@ -1075,6 +1089,10 @@ static int gtp_genl_tunnel_new(struct sk_buff *skb, struct genl_info *info) !info->attrs[GTPA_TID]) return -EINVAL; + net = gtp_genl_get_net(sock_net(skb->sk), info->attrs); + if (IS_ERR(net)) + return -EINVAL;