[PATCH 0/6] gtp: misc improvements

[PATCH 0/6] gtp: misc improvements

[Andreas Schultz]

Hi Pablo,

This series lays the groundwork for removing the socket references from
the GTP netdevice by removing duplicate code and simplifying the logic on
some code paths.

It slighly changes the GTP genl API by making the socket parameters optional
(though one of them is still required).

The removal of the socket references will break the 1:1 releation between
GTP netdevice and GTP socket that prevents us to support multiple VRFs with
overlaping IP addresse spaces attached to the same GTP socket (needed for
multi APN support).

Regards
Andreas

[PATCH 1/6] gtp: make GTP sockets in gtp_newlink optional

[Andreas Schultz]

Having both GTPv0-U and GTPv1-U is not always desirable.
Fallback from GTPv1-U to GTPv0-U was depreciated from 3GPP
Rel-8 onwards. Post Rel-8 implementation are discuraged
from listening on the v0 port (see 3GPP TS 29.281, Sect. 1).

A future change will completely decouple the sockets from the
network device. Till then, at least one of the sockets needs to
be specified (either v0 or v1), the other is optional.

Signed-off-by: Andreas Schultz <aschultz@tpip.net>
---
 drivers/net/gtp.c | 142 +++++++++++++++++++++++++++++-------------------------
 1 file changed, 76 insertions(+), 66 deletions(-)

diff --git a/drivers/net/gtp.c b/drivers/net/gtp.c
index bda0c64..18944f4 100644
--- a/drivers/net/gtp.c
+++ b/drivers/net/gtp.c
@@ -259,28 +259,30 @@ static int gtp1u_udp_encap_recv(struct gtp_dev *gtp, struct sk_buff *skb,
 	return iptunnel_pull_header(skb, hdrlen, skb->protocol, xnet);
 }
 
-static void gtp_encap_disable(struct gtp_dev *gtp)
-{
-	if (gtp->sock0 && gtp->sock0->sk) {
-		udp_sk(gtp->sock0->sk)->encap_type = 0;
-		rcu_assign_sk_user_data(gtp->sock0->sk, NULL);
-	}
-	if (gtp->sock1u && gtp->sock1u->sk) {
-		udp_sk(gtp->sock1u->sk)->encap_type = 0;
-		rcu_assign_sk_user_data(gtp->sock1u->sk, NULL);
-	}
-
-	gtp->sock0 = NULL;
-	gtp->sock1u = NULL;
-}
-
 static void gtp_encap_destroy(struct sock *sk)
 {
 	struct gtp_dev *gtp;
 
 	gtp = rcu_dereference_sk_user_data(sk);
-	if (gtp)
-		gtp_encap_disable(gtp);
+	if (gtp) {
+		udp_sk(sk)->encap_type = 0;
+		rcu_assign_sk_user_data(sk, NULL);
+	}
+}
+
+static void gtp_encap_disable_sock(struct socket *sock)
+{
+	if (!sock || !sock->sk)
+		return;
+
+	gtp_encap_destroy(sock->sk);
+	sockfd_put(sock);
+}
+
+static void gtp_encap_disable(struct gtp_dev *gtp)
+{
+	gtp_encap_disable_sock(gtp->sock0);
+	gtp_encap_disable_sock(gtp->sock1u);
 }
 
 /* UDP encapsulation receive handler. See net/ipv4/udp.c.
@@ -640,27 +642,24 @@ 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);
+static int gtp_encap_enable(struct gtp_dev *gtp, struct nlattr *data[]);
+static void gtp_encap_disable(struct gtp_dev *gtp);
 
 static int gtp_newlink(struct net *src_net, struct net_device *dev,
 			struct nlattr *tb[], struct nlattr *data[])
 {
-	int hashsize, err, fd0, fd1;
+	int hashsize, err;
 	struct gtp_dev *gtp;
 	struct gtp_net *gn;
 
-	if (!data[IFLA_GTP_FD0] || !data[IFLA_GTP_FD1])
+	if (!data[IFLA_GTP_FD0] && !data[IFLA_GTP_FD1])
 		return -EINVAL;
 
 	gtp = netdev_priv(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);
+	err = gtp_encap_enable(gtp, data);
 	if (err < 0)
-		goto out_err;
+		return err;
 
 	if (!data[IFLA_GTP_PDP_HASHSIZE])
 		hashsize = 1024;
@@ -688,7 +687,6 @@ static int gtp_newlink(struct net *src_net, struct net_device *dev,
 	gtp_hashtable_free(gtp);
 out_encap:
 	gtp_encap_disable(gtp);
-out_err:
 	return err;
 }
 
@@ -803,61 +801,73 @@ static void gtp_hashtable_free(struct gtp_dev *gtp)
 	kfree(gtp->tid_hash);
 }
 
-static int gtp_encap_enable(struct net_device *dev, struct gtp_dev *gtp,
-			    int fd_gtp0, int fd_gtp1)
+static struct socket *gtp_encap_enable_socket(int fd, int type,
+					      struct gtp_dev *gtp)
 {
 	struct udp_tunnel_sock_cfg tuncfg = {NULL};
-	struct socket *sock0, *sock1u;
+	struct socket *sock;
 	int err;
 
-	netdev_dbg(dev, "enable gtp on %d, %d\n", fd_gtp0, fd_gtp1);
+	pr_debug("enable gtp on %d, %d\n", fd, type);
 
-	sock0 = sockfd_lookup(fd_gtp0, &err);
-	if (sock0 == NULL) {
-		netdev_dbg(dev, "socket fd=%d not found (gtp0)\n", fd_gtp0);
-		return -ENOENT;
+	sock = sockfd_lookup(fd, &err);
+	if (!sock) {
+		pr_debug("gtp socket fd=%d not found\n", fd);
+		return NULL;
 	}
 
-	if (sock0->sk->sk_protocol != IPPROTO_UDP) {
-		netdev_dbg(dev, "socket fd=%d not UDP\n", fd_gtp0);
+	if (sock->sk->sk_protocol != IPPROTO_UDP) {
+		pr_debug("socket fd=%d not UDP\n", fd);
 		err = -EINVAL;
-		goto err1;
+		goto out_sock;
 	}
 
-	sock1u = sockfd_lookup(fd_gtp1, &err);
-	if (sock1u == NULL) {
-		netdev_dbg(dev, "socket fd=%d not found (gtp1u)\n", fd_gtp1);
-		err = -ENOENT;
-		goto err1;
+	if (rcu_dereference_sk_user_data(sock->sk)) {
+		err = -EBUSY;
+		goto out_sock;
 	}
 
-	if (sock1u->sk->sk_protocol != IPPROTO_UDP) {
-		netdev_dbg(dev, "socket fd=%d not UDP\n", fd_gtp1);
-		err = -EINVAL;
-		goto err2;
-	}
-
-	netdev_dbg(dev, "enable gtp on %p, %p\n", sock0, sock1u);
-
-	gtp->sock0 = sock0;
-	gtp->sock1u = sock1u;
-
 	tuncfg.sk_user_data = gtp;
+	tuncfg.encap_type = type;
 	tuncfg.encap_rcv = gtp_encap_recv;
 	tuncfg.encap_destroy = gtp_encap_destroy;
 
-	tuncfg.encap_type = UDP_ENCAP_GTP0;
-	setup_udp_tunnel_sock(sock_net(gtp->sock0->sk), gtp->sock0, &tuncfg);
-
-	tuncfg.encap_type = UDP_ENCAP_GTP1U;
-	setup_udp_tunnel_sock(sock_net(gtp->sock1u->sk), gtp->sock1u, &tuncfg);
-
-	err = 0;
-err2:
-	sockfd_put(sock1u);
-err1:
-	sockfd_put(sock0);
-	return err;
+	setup_udp_tunnel_sock(sock_net(sock->sk), sock, &tuncfg);
+	return sock;
+
+out_sock:
+	sockfd_put(sock);
+	return ERR_PTR(err);
+}
+
+static int gtp_encap_enable(struct gtp_dev *gtp, struct nlattr *data[])
+{
+	struct socket *sock0 = NULL;
+	struct socket *sock1u = NULL;
+
+	if (data[IFLA_GTP_FD0]) {
+		u32 fd0 = nla_get_u32(data[IFLA_GTP_FD0]);
+
+		sock0 = gtp_encap_enable_socket(fd0, UDP_ENCAP_GTP0, gtp);
+		if (IS_ERR(sock0))
+			return PTR_ERR(sock0);
+	}
+
+	if (data[IFLA_GTP_FD1]) {
+		u32 fd1 = nla_get_u32(data[IFLA_GTP_FD1]);
+
+		sock1u = gtp_encap_enable_socket(fd1, UDP_ENCAP_GTP1U, gtp);
+		if (IS_ERR(sock1u)) {
+			if (sock0)
+				sockfd_put(sock0);
+			return PTR_ERR(sock1u);
+		}
+	}
+
+	gtp->sock0 = sock0;
+	gtp->sock1u = sock1u;
+
+	return 0;
 }
 
 static struct net_device *gtp_find_dev(struct net *net, int ifindex)
-- 
2.10.2

[PATCH 2/6] gtp: merge gtp_get_net and gtp_genl_find_dev

[Andreas Schultz]

Both function are always used together with the final goal to
get the gtp_dev. This simplifies the code by merging them together.

The netdevice lookup is changed to use the regular dev_get_by_index.
The gtp netdevice list is now only used to find the PDP contexts for
imcomming packets. It can be completely eliminated Once the TEID
hash is moved into the GTP socket.

Signed-off-by: Andreas Schultz <aschultz@tpip.net>
---
 drivers/net/gtp.c | 170 ++++++++++++++++++++++++++----------------------------
 1 file changed, 81 insertions(+), 89 deletions(-)

diff --git a/drivers/net/gtp.c b/drivers/net/gtp.c
index 18944f4..c96c71f 100644
--- a/drivers/net/gtp.c
+++ b/drivers/net/gtp.c
@@ -745,21 +745,6 @@ 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_dev *gtp, int hsize)
 {
 	int i;
@@ -870,16 +855,31 @@ static int gtp_encap_enable(struct gtp_dev *gtp, struct nlattr *data[])
 	return 0;
 }
 
-static struct net_device *gtp_find_dev(struct net *net, int ifindex)
+static struct gtp_dev *gtp_genl_find_dev(struct net *src_net,
+					 struct nlattr *tb[])
 {
-	struct gtp_net *gn = net_generic(net, gtp_net_id);
-	struct gtp_dev *gtp;
-
-	list_for_each_entry_rcu(gtp, &gn->gtp_dev_list, list) {
-		if (ifindex == gtp->dev->ifindex)
-			return gtp->dev;
-	}
-	return NULL;
+	struct net *net;
+	struct net_device *dev;
+	struct gtp_dev *gtp = NULL;
+
+	/* 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);
+
+	if (IS_ERR(net))
+		return NULL;
+
+	/* Check if there's an existing gtpX device to configure */
+	dev = dev_get_by_index_rcu(net, nla_get_u32(tb[GTPA_LINK]));
+	if (dev->netdev_ops == &gtp_netdev_ops)
+		gtp = netdev_priv(dev);
+
+	put_net(net);
+	return gtp;
 }
 
 static void ipv4_pdp_fill(struct pdp_ctx *pctx, struct genl_info *info)
@@ -909,9 +909,8 @@ static void ipv4_pdp_fill(struct pdp_ctx *pctx, struct genl_info *info)
 	}
 }
 
-static int ipv4_pdp_add(struct net_device *dev, struct genl_info *info)
+static int ipv4_pdp_add(struct gtp_dev *gtp, struct genl_info *info)
 {
-	struct gtp_dev *gtp = netdev_priv(dev);
 	u32 hash_ms, hash_tid = 0;
 	struct pdp_ctx *pctx;
 	bool found = false;
@@ -936,11 +935,11 @@ static int ipv4_pdp_add(struct net_device *dev, struct genl_info *info)
 		ipv4_pdp_fill(pctx, info);
 
 		if (pctx->gtp_version == GTP_V0)
-			netdev_dbg(dev, "GTPv0-U: update tunnel id = %llx (pdp %p)\n",
-				   pctx->u.v0.tid, pctx);
+			pr_debug("GTPv0-U: update tunnel id = %llx (pdp %p)\n",
+				 pctx->u.v0.tid, pctx);
 		else if (pctx->gtp_version == GTP_V1)
-			netdev_dbg(dev, "GTPv1-U: update tunnel id = %x/%x (pdp %p)\n",
-				   pctx->u.v1.i_tei, pctx->u.v1.o_tei, pctx);
+			pr_debug("GTPv1-U: update tunnel id = %x/%x (pdp %p)\n",
+				 pctx->u.v1.i_tei, pctx->u.v1.o_tei, pctx);
 
 		return 0;
 
@@ -972,14 +971,14 @@ static int ipv4_pdp_add(struct net_device *dev, struct genl_info *info)
 
 	switch (pctx->gtp_version) {
 	case GTP_V0:
-		netdev_dbg(dev, "GTPv0-U: new PDP ctx id=%llx ssgn=%pI4 ms=%pI4 (pdp=%p)\n",
-			   pctx->u.v0.tid, &pctx->sgsn_addr_ip4,
-			   &pctx->ms_addr_ip4, pctx);
+		pr_debug("GTPv0-U: new PDP ctx id=%llx ssgn=%pI4 ms=%pI4 (pdp=%p)\n",
+			 pctx->u.v0.tid, &pctx->sgsn_addr_ip4,
+			 &pctx->ms_addr_ip4, pctx);
 		break;
 	case GTP_V1:
-		netdev_dbg(dev, "GTPv1-U: new PDP ctx id=%x/%x ssgn=%pI4 ms=%pI4 (pdp=%p)\n",
-			   pctx->u.v1.i_tei, pctx->u.v1.o_tei,
-			   &pctx->sgsn_addr_ip4, &pctx->ms_addr_ip4, pctx);
+		pr_debug("GTPv1-U: new PDP ctx id=%x/%x ssgn=%pI4 ms=%pI4 (pdp=%p)\n",
+			 pctx->u.v1.i_tei, pctx->u.v1.o_tei,
+			 &pctx->sgsn_addr_ip4, &pctx->ms_addr_ip4, pctx);
 		break;
 	}
 
@@ -988,8 +987,8 @@ static int ipv4_pdp_add(struct net_device *dev, struct genl_info *info)
 
 static int gtp_genl_new_pdp(struct sk_buff *skb, struct genl_info *info)
 {
-	struct net_device *dev;
-	struct net *net;
+	struct gtp_dev *gtp;
+	int err;
 
 	if (!info->attrs[GTPA_VERSION] ||
 	    !info->attrs[GTPA_LINK] ||
@@ -1013,77 +1012,79 @@ static int gtp_genl_new_pdp(struct sk_buff *skb, struct genl_info *info)
 		return -EINVAL;
 	}
 
-	net = gtp_genl_get_net(sock_net(skb->sk), info->attrs);
-	if (IS_ERR(net))
-		return PTR_ERR(net);
+	rcu_read_lock();
 
-	/* Check if there's an existing gtpX device to configure */
-	dev = gtp_find_dev(net, nla_get_u32(info->attrs[GTPA_LINK]));
-	if (dev == NULL) {
-		put_net(net);
-		return -ENODEV;
+	gtp = gtp_genl_find_dev(sock_net(skb->sk), info->attrs);
+	if (!gtp) {
+		err = -ENODEV;
+		goto out_unlock;
 	}
-	put_net(net);
 
-	return ipv4_pdp_add(dev, info);
+	err = ipv4_pdp_add(gtp, info);
+
+out_unlock:
+	rcu_read_unlock();
+	return err;
 }
 
 static int gtp_genl_del_pdp(struct sk_buff *skb, struct genl_info *info)
 {
-	struct net_device *dev;
 	struct pdp_ctx *pctx;
 	struct gtp_dev *gtp;
-	struct net *net;
+	int err = 0;
 
 	if (!info->attrs[GTPA_VERSION] ||
 	    !info->attrs[GTPA_LINK])
 		return -EINVAL;
 
-	net = gtp_genl_get_net(sock_net(skb->sk), info->attrs);
-	if (IS_ERR(net))
-		return PTR_ERR(net);
+	rcu_read_lock();
 
-	/* Check if there's an existing gtpX device to configure */
-	dev = gtp_find_dev(net, nla_get_u32(info->attrs[GTPA_LINK]));
-	if (dev == NULL) {
-		put_net(net);
-		return -ENODEV;
+	gtp = gtp_genl_find_dev(sock_net(skb->sk), info->attrs);
+	if (!gtp) {
+		err = -ENODEV;
+		goto out_unlock;
 	}
-	put_net(net);
-
-	gtp = netdev_priv(dev);
 
 	switch (nla_get_u32(info->attrs[GTPA_VERSION])) {
 	case GTP_V0:
-		if (!info->attrs[GTPA_TID])
-			return -EINVAL;
+		if (!info->attrs[GTPA_TID]) {
+			err = -EINVAL;
+			goto out_unlock;
+		}
 		pctx = gtp0_pdp_find(gtp, nla_get_u64(info->attrs[GTPA_TID]));
 		break;
 	case GTP_V1:
-		if (!info->attrs[GTPA_I_TEI])
-			return -EINVAL;
+		if (!info->attrs[GTPA_I_TEI]) {
+			err = -EINVAL;
+			goto out_unlock;
+		}
 		pctx = gtp1_pdp_find(gtp, nla_get_u64(info->attrs[GTPA_I_TEI]));
 		break;
 
 	default:
-		return -EINVAL;
+		err = -EINVAL;
+		goto out_unlock;
 	}
 
-	if (pctx == NULL)
-		return -ENOENT;
+	if (!pctx) {
+		err = -ENOENT;
+		goto out_unlock;
+	}
 
 	if (pctx->gtp_version == GTP_V0)
-		netdev_dbg(dev, "GTPv0-U: deleting tunnel id = %llx (pdp %p)\n",
-			   pctx->u.v0.tid, pctx);
+		pr_debug("GTPv0-U: deleting tunnel id = %llx (pdp %p)\n",
+			 pctx->u.v0.tid, pctx);
 	else if (pctx->gtp_version == GTP_V1)
-		netdev_dbg(dev, "GTPv1-U: deleting tunnel id = %x/%x (pdp %p)\n",
-			   pctx->u.v1.i_tei, pctx->u.v1.o_tei, pctx);
+		pr_debug("GTPv1-U: deleting tunnel id = %x/%x (pdp %p)\n",
+			 pctx->u.v1.i_tei, pctx->u.v1.o_tei, pctx);
 
 	hlist_del_rcu(&pctx->hlist_tid);
 	hlist_del_rcu(&pctx->hlist_addr);
 	kfree_rcu(pctx, rcu_head);
 
-	return 0;
+out_unlock:
+	rcu_read_unlock();
+	return err;
 }
 
 static struct genl_family gtp_genl_family;
@@ -1127,11 +1128,9 @@ static int gtp_genl_fill_info(struct sk_buff *skb, u32 snd_portid, u32 snd_seq,
 static int gtp_genl_get_pdp(struct sk_buff *skb, struct genl_info *info)
 {
 	struct pdp_ctx *pctx = NULL;
-	struct net_device *dev;
 	struct sk_buff *skb2;
 	struct gtp_dev *gtp;
 	u32 gtp_version;
-	struct net *net;
 	int err;
 
 	if (!info->attrs[GTPA_VERSION] ||
@@ -1147,21 +1146,14 @@ static int gtp_genl_get_pdp(struct sk_buff *skb, struct genl_info *info)
 		return -EINVAL;
 	}
 
-	net = gtp_genl_get_net(sock_net(skb->sk), info->attrs);
-	if (IS_ERR(net))
-		return PTR_ERR(net);
-
-	/* Check if there's an existing gtpX device to configure */
-	dev = gtp_find_dev(net, nla_get_u32(info->attrs[GTPA_LINK]));
-	if (dev == NULL) {
-		put_net(net);
-		return -ENODEV;
-	}
-	put_net(net);
-
-	gtp = netdev_priv(dev);
-
 	rcu_read_lock();
+
+	gtp = gtp_genl_find_dev(sock_net(skb->sk), info->attrs);
+	if (!gtp) {
+		err = -ENODEV;
+		goto err_unlock;
+	}
+
 	if (gtp_version == GTP_V0 &&
 	    info->attrs[GTPA_TID]) {
 		u64 tid = nla_get_u64(info->attrs[GTPA_TID]);
-- 
2.10.2

[PATCH 3/6] gtp: unify genl_find_pdp and prepare for per socket lookup

[Andreas Schultz]

This unifies duplicate code into a helper. It also prepares the
groundwork to add a lookup version that uses the socket to find
attache pdp contexts.

Signed-off-by: Andreas Schultz <aschultz@tpip.net>
---
 drivers/net/gtp.c | 120 +++++++++++++++++++++++-------------------------------
 1 file changed, 51 insertions(+), 69 deletions(-)

diff --git a/drivers/net/gtp.c b/drivers/net/gtp.c
index c96c71f..6b7a3c2 100644
--- a/drivers/net/gtp.c
+++ b/drivers/net/gtp.c
@@ -1027,47 +1027,62 @@ static int gtp_genl_new_pdp(struct sk_buff *skb, struct genl_info *info)
 	return err;
 }
 
+static struct pdp_ctx *gtp_genl_find_pdp_by_link(struct sk_buff *skb,
+						 struct genl_info *info)
+{
+	struct gtp_dev *gtp;
+
+	gtp = gtp_genl_find_dev(sock_net(skb->sk), info->attrs);
+	if (!gtp)
+		return ERR_PTR(-ENODEV);
+
+	if (info->attrs[GTPA_MS_ADDRESS]) {
+		__be32 ip = nla_get_be32(info->attrs[GTPA_MS_ADDRESS]);
+
+		return ipv4_pdp_find(gtp, ip);
+	} else if (info->attrs[GTPA_VERSION]) {
+		u32 gtp_version = nla_get_u32(info->attrs[GTPA_VERSION]);
+
+		if (gtp_version == GTP_V0 && info->attrs[GTPA_TID])
+			return gtp0_pdp_find(gtp, nla_get_u64(
+						     info->attrs[GTPA_TID]));
+		else if (gtp_version == GTP_V1 && info->attrs[GTPA_I_TEI])
+			return gtp1_pdp_find(gtp, nla_get_u32(
+						     info->attrs[GTPA_I_TEI]));
+	}
+
+	return ERR_PTR(-EINVAL);
+}
+
+static struct pdp_ctx *gtp_genl_find_pdp(struct sk_buff *skb,
+					 struct genl_info *info)
+{
+	struct pdp_ctx *pctx;
+
+	if (info->attrs[GTPA_LINK])
+		pctx = gtp_genl_find_pdp_by_link(skb, info);
+	else
+		pctx = ERR_PTR(-EINVAL);
+
+	if (!pctx)
+		pctx = ERR_PTR(-ENOENT);
+
+	return pctx;
+}
+
 static int gtp_genl_del_pdp(struct sk_buff *skb, struct genl_info *info)
 {
 	struct pdp_ctx *pctx;
-	struct gtp_dev *gtp;
 	int err = 0;
 
-	if (!info->attrs[GTPA_VERSION] ||
-	    !info->attrs[GTPA_LINK])
+	if (!info->attrs[GTPA_VERSION])
 		return -EINVAL;
 
 	rcu_read_lock();
 
-	gtp = gtp_genl_find_dev(sock_net(skb->sk), info->attrs);
-	if (!gtp) {
-		err = -ENODEV;
-		goto out_unlock;
-	}
-
-	switch (nla_get_u32(info->attrs[GTPA_VERSION])) {
-	case GTP_V0:
-		if (!info->attrs[GTPA_TID]) {
-			err = -EINVAL;
-			goto out_unlock;
-		}
-		pctx = gtp0_pdp_find(gtp, nla_get_u64(info->attrs[GTPA_TID]));
-		break;
-	case GTP_V1:
-		if (!info->attrs[GTPA_I_TEI]) {
-			err = -EINVAL;
-			goto out_unlock;
-		}
-		pctx = gtp1_pdp_find(gtp, nla_get_u64(info->attrs[GTPA_I_TEI]));
-		break;
-
-	default:
-		err = -EINVAL;
-		goto out_unlock;
-	}
-
-	if (!pctx) {
-		err = -ENOENT;
+	pctx = gtp_genl_find_pdp(skb, info);
+	if (IS_ERR(pctx)) {
+		err = PTR_ERR(pctx);
 		goto out_unlock;
 	}
 
@@ -1129,49 +1144,16 @@ static int gtp_genl_get_pdp(struct sk_buff *skb, struct genl_info *info)
 {
 	struct pdp_ctx *pctx = NULL;
 	struct sk_buff *skb2;
-	struct gtp_dev *gtp;
-	u32 gtp_version;
 	int err;
 
-	if (!info->attrs[GTPA_VERSION] ||
-	    !info->attrs[GTPA_LINK])
+	if (!info->attrs[GTPA_VERSION])
 		return -EINVAL;
 
-	gtp_version = nla_get_u32(info->attrs[GTPA_VERSION]);
-	switch (gtp_version) {
-	case GTP_V0:
-	case GTP_V1:
-		break;
-	default:
-		return -EINVAL;
-	}
-
 	rcu_read_lock();
 
-	gtp = gtp_genl_find_dev(sock_net(skb->sk), info->attrs);
-	if (!gtp) {
-		err = -ENODEV;
-		goto err_unlock;
-	}
-
-	if (gtp_version == GTP_V0 &&
-	    info->attrs[GTPA_TID]) {
-		u64 tid = nla_get_u64(info->attrs[GTPA_TID]);
-
-		pctx = gtp0_pdp_find(gtp, tid);
-	} else if (gtp_version == GTP_V1 &&
-		 info->attrs[GTPA_I_TEI]) {
-		u32 tid = nla_get_u32(info->attrs[GTPA_I_TEI]);
-
-		pctx = gtp1_pdp_find(gtp, tid);
-	} else if (info->attrs[GTPA_MS_ADDRESS]) {
-		__be32 ip = nla_get_be32(info->attrs[GTPA_MS_ADDRESS]);
-
-		pctx = ipv4_pdp_find(gtp, ip);
-	}
-
-	if (pctx == NULL) {
-		err = -ENOENT;
+	pctx = gtp_genl_find_pdp(skb, info);
+	if (IS_ERR(pctx)) {
+		err = PTR_ERR(pctx);
 		goto err_unlock;
 	}
 
-- 
2.10.2

[PATCH 4/6] gtp: consolidate pdp context destruction into helper

[Andreas Schultz]

Consolidate duplicate code into helper.

Signed-off-by: Andreas Schultz <aschultz@tpip.net>
---
 drivers/net/gtp.c | 24 ++++++++++++++----------
 1 file changed, 14 insertions(+), 10 deletions(-)

diff --git a/drivers/net/gtp.c b/drivers/net/gtp.c
index 6b7a3c2..68c6c9b 100644
--- a/drivers/net/gtp.c
+++ b/drivers/net/gtp.c
@@ -84,6 +84,8 @@ struct gtp_net {
 
 static u32 gtp_h_initval;
 
+static void pdp_context_delete(struct pdp_ctx *pctx);
+
 static inline u32 gtp0_hashfn(u64 tid)
 {
 	u32 *tid32 = (u32 *) &tid;
@@ -774,13 +776,10 @@ static void gtp_hashtable_free(struct gtp_dev *gtp)
 	struct pdp_ctx *pctx;
 	int i;
 
-	for (i = 0; i < gtp->hash_size; i++) {
-		hlist_for_each_entry_rcu(pctx, &gtp->tid_hash[i], hlist_tid) {
-			hlist_del_rcu(&pctx->hlist_tid);
-			hlist_del_rcu(&pctx->hlist_addr);
-			kfree_rcu(pctx, rcu_head);
-		}
-	}
+	for (i = 0; i < gtp->hash_size; i++)
+		hlist_for_each_entry_rcu(pctx, &gtp->tid_hash[i], hlist_tid)
+			pdp_context_delete(pctx);
+
 	synchronize_rcu();
 	kfree(gtp->addr_hash);
 	kfree(gtp->tid_hash);
@@ -985,6 +984,13 @@ static int ipv4_pdp_add(struct gtp_dev *gtp, struct genl_info *info)
 	return 0;
 }
 
+static void pdp_context_delete(struct pdp_ctx *pctx)
+{
+	hlist_del_rcu(&pctx->hlist_tid);
+	hlist_del_rcu(&pctx->hlist_addr);
+	kfree(pctx);
+}
+
 static int gtp_genl_new_pdp(struct sk_buff *skb, struct genl_info *info)
 {
 	struct gtp_dev *gtp;
@@ -1093,9 +1099,7 @@ static int gtp_genl_del_pdp(struct sk_buff *skb, struct genl_info *info)
 		pr_debug("GTPv1-U: deleting tunnel id = %x/%x (pdp %p)\n",
 			 pctx->u.v1.i_tei, pctx->u.v1.o_tei, pctx);
 
-	hlist_del_rcu(&pctx->hlist_tid);
-	hlist_del_rcu(&pctx->hlist_addr);
-	kfree_rcu(pctx, rcu_head);
+	pdp_context_delete(pctx);
 
 out_unlock:
 	rcu_read_unlock();
-- 
2.10.2

[PATCH 5/6] gtp: add socket to pdp context

[Andreas Schultz]

Having the socket present in context simplifies the sending logic.
It also fixes the invalid assumption that we have to use the same
sending socket for all client IP's on a specific gtp interface.

Signed-off-by: Andreas Schultz <aschultz@tpip.net>
---
 drivers/net/gtp.c | 72 ++++++++++++++++++++++++++++++-------------------------
 1 file changed, 39 insertions(+), 33 deletions(-)

diff --git a/drivers/net/gtp.c b/drivers/net/gtp.c
index 68c6c9b..ff00597 100644
--- a/drivers/net/gtp.c
+++ b/drivers/net/gtp.c
@@ -58,6 +58,8 @@ struct pdp_ctx {
 	struct in_addr		ms_addr_ip4;
 	struct in_addr		sgsn_addr_ip4;
 
+	struct sock		*sk;
+
 	atomic_t		tx_seq;
 	struct rcu_head		rcu_head;
 };
@@ -371,8 +373,9 @@ static void gtp_dev_uninit(struct net_device *dev)
 	free_percpu(dev->tstats);
 }
 
-static struct rtable *ip4_route_output_gtp(struct net *net, struct flowi4 *fl4,
-					   const struct sock *sk, __be32 daddr)
+static struct rtable *ip4_route_output_gtp(struct flowi4 *fl4,
+					   const struct sock *sk,
+					   __be32 daddr)
 {
 	memset(fl4, 0, sizeof(*fl4));
 	fl4->flowi4_oif		= sk->sk_bound_dev_if;
@@ -381,7 +384,7 @@ static struct rtable *ip4_route_output_gtp(struct net *net, struct flowi4 *fl4,
 	fl4->flowi4_tos		= RT_CONN_FLAGS(sk);
 	fl4->flowi4_proto	= sk->sk_protocol;
 
-	return ip_route_output_key(net, fl4);
+	return ip_route_output_key(sock_net(sk), fl4);
 }
 
 static inline void gtp0_push_header(struct sk_buff *skb, struct pdp_ctx *pctx)
@@ -470,7 +473,6 @@ static int gtp_build_skb_ip4(struct sk_buff *skb, struct net_device *dev,
 	struct rtable *rt;
 	struct flowi4 fl4;
 	struct iphdr *iph;
-	struct sock *sk;
 	__be16 df;
 	int mtu;
 
@@ -486,30 +488,7 @@ static int gtp_build_skb_ip4(struct sk_buff *skb, struct net_device *dev,
 	}
 	netdev_dbg(dev, "found PDP context %p\n", pctx);
 
-	switch (pctx->gtp_version) {
-	case GTP_V0:
-		if (gtp->sock0)
-			sk = gtp->sock0->sk;
-		else
-			sk = NULL;
-		break;
-	case GTP_V1:
-		if (gtp->sock1u)
-			sk = gtp->sock1u->sk;
-		else
-			sk = NULL;
-		break;
-	default:
-		return -ENOENT;
-	}
-
-	if (!sk) {
-		netdev_dbg(dev, "no userspace socket is available, skip\n");
-		return -ENOENT;
-	}
-
-	rt = ip4_route_output_gtp(sock_net(sk), &fl4, gtp->sock0->sk,
-				  pctx->sgsn_addr_ip4.s_addr);
+	rt = ip4_route_output_gtp(&fl4, pctx->sk, pctx->sgsn_addr_ip4.s_addr);
 	if (IS_ERR(rt)) {
 		netdev_dbg(dev, "no route to SSGN %pI4\n",
 			   &pctx->sgsn_addr_ip4.s_addr);
@@ -554,7 +533,7 @@ static int gtp_build_skb_ip4(struct sk_buff *skb, struct net_device *dev,
 		goto err_rt;
 	}
 
-	gtp_set_pktinfo_ipv4(pktinfo, sk, iph, pctx, rt, &fl4, dev);
+	gtp_set_pktinfo_ipv4(pktinfo, pctx->sk, iph, pctx, rt, &fl4, dev);
 	gtp_push_header(skb, pktinfo);
 
 	return 0;
@@ -908,7 +887,8 @@ static void ipv4_pdp_fill(struct pdp_ctx *pctx, struct genl_info *info)
 	}
 }
 
-static int ipv4_pdp_add(struct gtp_dev *gtp, struct genl_info *info)
+static int ipv4_pdp_add(struct gtp_dev *gtp, struct sock *sk,
+			struct genl_info *info)
 {
 	u32 hash_ms, hash_tid = 0;
 	struct pdp_ctx *pctx;
@@ -948,6 +928,8 @@ static int ipv4_pdp_add(struct gtp_dev *gtp, struct genl_info *info)
 	if (pctx == NULL)
 		return -ENOMEM;
 
+	sock_hold(sk);
+	pctx->sk = sk;
 	ipv4_pdp_fill(pctx, info);
 	atomic_set(&pctx->tx_seq, 0);
 
@@ -984,16 +966,26 @@ static int ipv4_pdp_add(struct gtp_dev *gtp, struct genl_info *info)
 	return 0;
 }
 
+static void pdp_context_free(struct rcu_head *head)
+{
+	struct pdp_ctx *pctx = container_of(head, struct pdp_ctx, rcu_head);
+
+	sock_put(pctx->sk);
+	kfree(pctx);
+}
+
 static void pdp_context_delete(struct pdp_ctx *pctx)
 {
 	hlist_del_rcu(&pctx->hlist_tid);
 	hlist_del_rcu(&pctx->hlist_addr);
-	kfree(pctx);
+	call_rcu(&pctx->rcu_head, pdp_context_free);
 }
 
 static int gtp_genl_new_pdp(struct sk_buff *skb, struct genl_info *info)
 {
+	unsigned int version;
 	struct gtp_dev *gtp;
+	struct socket *sock;
 	int err;
 
 	if (!info->attrs[GTPA_VERSION] ||
@@ -1002,7 +994,9 @@ static int gtp_genl_new_pdp(struct sk_buff *skb, struct genl_info *info)
 	    !info->attrs[GTPA_MS_ADDRESS])
 		return -EINVAL;
 
-	switch (nla_get_u32(info->attrs[GTPA_VERSION])) {
+	version = nla_get_u32(info->attrs[GTPA_VERSION]);
+
+	switch (version) {
 	case GTP_V0:
 		if (!info->attrs[GTPA_TID] ||
 		    !info->attrs[GTPA_FLOW])
@@ -1026,7 +1020,19 @@ static int gtp_genl_new_pdp(struct sk_buff *skb, struct genl_info *info)
 		goto out_unlock;
 	}
 
-	err = ipv4_pdp_add(gtp, info);
+	if (version == GTP_V0)
+		sock = gtp->sock0;
+	else if (version == GTP_V1)
+		sock = gtp->sock1u;
+	else
+		sock = NULL;
+
+	if (!sock || !sock->sk) {
+		err = -ENODEV;
+		goto out_unlock;
+	}
+
+	err = ipv4_pdp_add(gtp, sock->sk, info);
 
 out_unlock:
 	rcu_read_unlock();
-- 
2.10.2

[PATCH 6/6] gtp: consolidate gtp socket rx path

[Andreas Schultz]

Add network device to gtp context in preparation for splitting
the TEID from the network device.

Use this to rework the socker rx path. Move the common RX part
of v0 and v1 into a helper. Also move the final rx part into
that helper as well.

Signed-off-by: Andreas Schultz <aschultz@tpip.net>
---
 drivers/net/gtp.c | 92 ++++++++++++++++++++++++++++---------------------------
 1 file changed, 47 insertions(+), 45 deletions(-)

diff --git a/drivers/net/gtp.c b/drivers/net/gtp.c
index ff00597..9c31e83 100644
--- a/drivers/net/gtp.c
+++ b/drivers/net/gtp.c
@@ -58,6 +58,7 @@ struct pdp_ctx {
 	struct in_addr		ms_addr_ip4;
 	struct in_addr		sgsn_addr_ip4;
 
+	struct net_device       *dev;
 	struct sock		*sk;
 
 	atomic_t		tx_seq;
@@ -179,9 +180,42 @@ static bool gtp_check_src_ms(struct sk_buff *skb, struct pdp_ctx *pctx,
 	return false;
 }
 
+static int gtp_rx(struct sk_buff *skb, struct pdp_ctx *pctx, unsigned int hdrlen)
+{
+	struct pcpu_sw_netstats *stats;
+
+	if (!gtp_check_src_ms(skb, pctx, hdrlen)) {
+		pr_debug("No PDP ctx for this MS\n");
+		return 1;
+	}
+
+	/* Get rid of the GTP + UDP headers. */
+	if (iptunnel_pull_header(skb, hdrlen, skb->protocol,
+				 !net_eq(sock_net(pctx->sk), dev_net(pctx->dev))))
+		return -1;
+
+	pr_debug("forwarding packet from GGSN to uplink\n");
+
+	/* Now that the UDP and the GTP header have been removed, set up the
+	 * new network header. This is required by the upper layer to
+	 * calculate the transport header.
+	 */
+	skb_reset_network_header(skb);
+
+	skb->dev = pctx->dev;
+
+	stats = this_cpu_ptr(pctx->dev->tstats);
+	u64_stats_update_begin(&stats->syncp);
+	stats->rx_packets++;
+	stats->rx_bytes += skb->len;
+	u64_stats_update_end(&stats->syncp);
+
+	netif_rx(skb);
+	return 0;
+}
+
 /* 1 means pass up to the stack, -1 means drop and 0 means decapsulated. */
-static int gtp0_udp_encap_recv(struct gtp_dev *gtp, struct sk_buff *skb,
-			       bool xnet)
+static int gtp0_udp_encap_recv(struct gtp_dev *gtp, struct sk_buff *skb)
 {
 	unsigned int hdrlen = sizeof(struct udphdr) +
 			      sizeof(struct gtp0_header);
@@ -205,17 +239,10 @@ static int gtp0_udp_encap_recv(struct gtp_dev *gtp, struct sk_buff *skb,
 		return 1;
 	}
 
-	if (!gtp_check_src_ms(skb, pctx, hdrlen)) {
-		netdev_dbg(gtp->dev, "No PDP ctx for this MS\n");
-		return 1;
-	}
-
-	/* Get rid of the GTP + UDP headers. */
-	return iptunnel_pull_header(skb, hdrlen, skb->protocol, xnet);
+	return gtp_rx(skb, pctx, hdrlen);
 }
 
-static int gtp1u_udp_encap_recv(struct gtp_dev *gtp, struct sk_buff *skb,
-				bool xnet)
+static int gtp1u_udp_encap_recv(struct gtp_dev *gtp, struct sk_buff *skb)
 {
 	unsigned int hdrlen = sizeof(struct udphdr) +
 			      sizeof(struct gtp1_header);
@@ -254,13 +281,7 @@ static int gtp1u_udp_encap_recv(struct gtp_dev *gtp, struct sk_buff *skb,
 		return 1;
 	}
 
-	if (!gtp_check_src_ms(skb, pctx, hdrlen)) {
-		netdev_dbg(gtp->dev, "No PDP ctx for this MS\n");
-		return 1;
-	}
-
-	/* Get rid of the GTP + UDP headers. */
-	return iptunnel_pull_header(skb, hdrlen, skb->protocol, xnet);
+	return gtp_rx(skb, pctx, hdrlen);
 }
 
 static void gtp_encap_destroy(struct sock *sk)
@@ -294,10 +315,8 @@ static void gtp_encap_disable(struct gtp_dev *gtp)
  */
 static int gtp_encap_recv(struct sock *sk, struct sk_buff *skb)
 {
-	struct pcpu_sw_netstats *stats;
 	struct gtp_dev *gtp;
-	bool xnet;
-	int ret;
+	int ret = 0;
 
 	gtp = rcu_dereference_sk_user_data(sk);
 	if (!gtp)
@@ -305,16 +324,14 @@ 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(sock_net(sk), dev_net(gtp->dev));
-
 	switch (udp_sk(sk)->encap_type) {
 	case UDP_ENCAP_GTP0:
 		netdev_dbg(gtp->dev, "received GTP0 packet\n");
-		ret = gtp0_udp_encap_recv(gtp, skb, xnet);
+		ret = gtp0_udp_encap_recv(gtp, skb);
 		break;
 	case UDP_ENCAP_GTP1U:
 		netdev_dbg(gtp->dev, "received GTP1U packet\n");
-		ret = gtp1u_udp_encap_recv(gtp, skb, xnet);
+		ret = gtp1u_udp_encap_recv(gtp, skb);
 		break;
 	default:
 		ret = -1; /* Shouldn't happen. */
@@ -323,33 +340,17 @@ static int gtp_encap_recv(struct sock *sk, struct sk_buff *skb)
 	switch (ret) {
 	case 1:
 		netdev_dbg(gtp->dev, "pass up to the process\n");
-		return 1;
+		break;
 	case 0:
-		netdev_dbg(gtp->dev, "forwarding packet from GGSN to uplink\n");
 		break;
 	case -1:
 		netdev_dbg(gtp->dev, "GTP packet has been dropped\n");
 		kfree_skb(skb);
-		return 0;
+		ret = 0;
+		break;
 	}
 
-	/* Now that the UDP and the GTP header have been removed, set up the
-	 * new network header. This is required by the upper layer to
-	 * calculate the transport header.
-	 */
-	skb_reset_network_header(skb);
-
-	skb->dev = gtp->dev;
-
-	stats = this_cpu_ptr(gtp->dev->tstats);
-	u64_stats_update_begin(&stats->syncp);
-	stats->rx_packets++;
-	stats->rx_bytes += skb->len;
-	u64_stats_update_end(&stats->syncp);
-
-	netif_rx(skb);
-
-	return 0;
+	return ret;
 }
 
 static int gtp_dev_init(struct net_device *dev)
@@ -930,6 +931,7 @@ static int ipv4_pdp_add(struct gtp_dev *gtp, struct sock *sk,
 
 	sock_hold(sk);
 	pctx->sk = sk;
+	pctx->dev = gtp->dev;
 	ipv4_pdp_fill(pctx, info);
 	atomic_set(&pctx->tx_seq, 0);
 
-- 
2.10.2