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

On Tue, Nov 17, 2015 at 12:06:19PM +0100, Andreas Schultz wrote:

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 aschultz@tpip.net

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;
  

You probably want to propagate the real error reason:

return PTR_ERR(net);