[PATCH net v3 0/3] various gtp fixes

[PATCH net v3 0/3] various gtp fixes

[Andreas Schultz]

I'm sorry for the compile error mess up in the last version.
It's no excuse for not test compiling, but the hunks got lost in
a rebase.

This is the part of the previous "simple gtp improvements" series
that Pablo indicated should go into net.

The addition of the module alias fixes genl family autoloading,
clearing the DF bit fixes a protocol violation in regard to the
specification and the netns comparison fixes a corner case of
cross netns recv.

Andreas

v2->v3: fix compiler error introduced in rebase

[PATCH net v3 1/3] gtp: add genl family modules alias

[Andreas Schultz]

Auto-load the module when userspace asks for the gtp netlink
family.

Signed-off-by: Andreas Schultz <aschultz@tpip.net>
Acked-by: Harald Welte <laforge@netfilter.org>
Acked-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 drivers/net/gtp.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/net/gtp.c b/drivers/net/gtp.c
index 8b6810b..7580ccc 100644
--- a/drivers/net/gtp.c
+++ b/drivers/net/gtp.c
@@ -1376,3 +1376,4 @@ MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Harald Welte <hwelte@sysmocom.de>");
 MODULE_DESCRIPTION("Interface driver for GTP encapsulated traffic");
 MODULE_ALIAS_RTNL_LINK("gtp");
+MODULE_ALIAS_GENL_FAMILY("gtp");
-- 
2.10.2

[PATCH net v3 2/3] gtp: clear DF bit on GTP packet tx

[Andreas Schultz]

3GPP TS 29.281 and 3GPP TS 29.060 imply that GTP-U packets should be
sent with the DF bit cleared. For example 3GPP TS 29.060, Release 8,
Section 13.2.2:

> Backbone router: Any router in the backbone may fragment the GTP
> packet if needed, according to IPv4.

Signed-off-by: Andreas Schultz <aschultz@tpip.net>
Acked-by: Harald Welte <laforge@netfilter.org>
Acked-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 drivers/net/gtp.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/gtp.c b/drivers/net/gtp.c
index 7580ccc..1df54d6 100644
--- a/drivers/net/gtp.c
+++ b/drivers/net/gtp.c
@@ -612,7 +612,7 @@ static netdev_tx_t gtp_dev_xmit(struct sk_buff *skb, struct net_device *dev)
 				    pktinfo.fl4.saddr, pktinfo.fl4.daddr,
 				    pktinfo.iph->tos,
 				    ip4_dst_hoplimit(&pktinfo.rt->dst),
-				    htons(IP_DF),
+				    0,
 				    pktinfo.gtph_port, pktinfo.gtph_port,
 				    true, false);
 		break;
-- 
2.10.2

[PATCH net v3 3/3] gtp: fix cross netns recv on gtp socket

[Andreas Schultz]

The use of the passed through netlink src_net to check for a
cross netns operation was wrong. Using the GTP socket and the
GTP netdevice is always correct (even if the netdev has been
moved to new netns after link creation).

Remove the now obsolete net field from gtp_dev.

Signed-off-by: Andreas Schultz <aschultz@tpip.net>
Acked-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 drivers/net/gtp.c | 10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/drivers/net/gtp.c b/drivers/net/gtp.c
index 1df54d6..99d3df7 100644
--- a/drivers/net/gtp.c
+++ b/drivers/net/gtp.c
@@ -69,7 +69,6 @@ struct gtp_dev {
 	struct socket		*sock0;
 	struct socket		*sock1u;
 
-	struct net		*net;
 	struct net_device	*dev;
 
 	unsigned int		hash_size;
@@ -316,7 +315,7 @@ static int gtp_encap_recv(struct sock *sk, struct sk_buff *skb)
 
 	netdev_dbg(gtp->dev, "encap_recv sk=%p\n", sk);
 
-	xnet = !net_eq(gtp->net, dev_net(gtp->dev));
+	xnet = !net_eq(sock_net(sk), dev_net(gtp->dev));
 
 	switch (udp_sk(sk)->encap_type) {
 	case UDP_ENCAP_GTP0:
@@ -658,7 +657,7 @@ static void gtp_link_setup(struct net_device *dev)
 static int gtp_hashtable_new(struct gtp_dev *gtp, int hsize);
 static void gtp_hashtable_free(struct gtp_dev *gtp);
 static int gtp_encap_enable(struct net_device *dev, struct gtp_dev *gtp,
-			    int fd_gtp0, int fd_gtp1, struct net *src_net);
+			    int fd_gtp0, int fd_gtp1);
 
 static int gtp_newlink(struct net *src_net, struct net_device *dev,
 			struct nlattr *tb[], struct nlattr *data[])
@@ -675,7 +674,7 @@ static int gtp_newlink(struct net *src_net, struct net_device *dev,
 	fd0 = nla_get_u32(data[IFLA_GTP_FD0]);
 	fd1 = nla_get_u32(data[IFLA_GTP_FD1]);
 
-	err = gtp_encap_enable(dev, gtp, fd0, fd1, src_net);
+	err = gtp_encap_enable(dev, gtp, fd0, fd1);
 	if (err < 0)
 		goto out_err;
 
@@ -821,7 +820,7 @@ static void gtp_hashtable_free(struct gtp_dev *gtp)
 }
 
 static int gtp_encap_enable(struct net_device *dev, struct gtp_dev *gtp,
-			    int fd_gtp0, int fd_gtp1, struct net *src_net)
+			    int fd_gtp0, int fd_gtp1)
 {
 	struct udp_tunnel_sock_cfg tuncfg = {NULL};
 	struct socket *sock0, *sock1u;
@@ -858,7 +857,6 @@ static int gtp_encap_enable(struct net_device *dev, struct gtp_dev *gtp,
 
 	gtp->sock0 = sock0;
 	gtp->sock1u = sock1u;
-	gtp->net = src_net;
 
 	tuncfg.sk_user_data = gtp;
 	tuncfg.encap_rcv = gtp_encap_recv;
-- 
2.10.2

Re: [PATCH net v3 0/3] various gtp fixes

[David Miller]

From: Andreas Schultz <aschultz@tpip.net>
Date: Fri, 27 Jan 2017 10:40:55 +0100

> I'm sorry for the compile error mess up in the last version.
> It's no excuse for not test compiling, but the hunks got lost in
> a rebase.
> 
> This is the part of the previous "simple gtp improvements" series
> that Pablo indicated should go into net.
> 
> The addition of the module alias fixes genl family autoloading,
> clearing the DF bit fixes a protocol violation in regard to the
> specification and the netns comparison fixes a corner case of
> cross netns recv.
> 
> Andreas
> 
> v2->v3: fix compiler error introduced in rebase

Looks better, series applied, thanks.