[ovs-dev] [PATCH net-next v1 2/3] gtp: Support creating flow-based gtp net_device
Jiannan Ouyang
ouyangj at fb.com
Thu Jul 13 00:44:54 UTC 2017
Add the gtp_create_flow_based_dev() interface to create flow-based gtp
net_device, which sets gtp->collect_md. Under flow-based mode, UDP sockets are
created and maintained in kernel.
Signed-off-by: Jiannan Ouyang <ouyangj at fb.com>
---
drivers/net/gtp.c | 213 +++++++++++++++++++++++++++++++++++++++++++++++++++++-
include/net/gtp.h | 8 ++
2 files changed, 217 insertions(+), 4 deletions(-)
diff --git a/drivers/net/gtp.c b/drivers/net/gtp.c
index 5a7b504..09712c9 100644
--- a/drivers/net/gtp.c
+++ b/drivers/net/gtp.c
@@ -642,9 +642,94 @@ static netdev_tx_t gtp_dev_xmit(struct sk_buff *skb, struct net_device *dev)
return NETDEV_TX_OK;
}
+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 gtp_dev *gtp, struct nlattr *data[]);
+
+static int gtp_change_mtu(struct net_device *dev, int new_mtu, bool strict)
+{
+ int max_mtu = IP_MAX_MTU - dev->hard_header_len - sizeof(struct iphdr)
+ - sizeof(struct udphdr) - sizeof(struct gtp1_header);
+
+ if (new_mtu < ETH_MIN_MTU)
+ return -EINVAL;
+
+ if (new_mtu > max_mtu) {
+ if (strict)
+ return -EINVAL;
+
+ new_mtu = max_mtu;
+ }
+
+ dev->mtu = new_mtu;
+ return 0;
+}
+
+static int gtp_dev_open(struct net_device *dev)
+{
+ struct gtp_dev *gtp = netdev_priv(dev);
+ struct net *net = gtp->net;
+ struct socket *sock1u;
+ struct socket *sock0;
+ struct udp_tunnel_sock_cfg tunnel_cfg;
+ struct udp_port_cfg udp_conf;
+ int err;
+
+ memset(&udp_conf, 0, sizeof(udp_conf));
+
+ udp_conf.family = AF_INET;
+ udp_conf.local_ip.s_addr = htonl(INADDR_ANY);
+ udp_conf.local_udp_port = htons(GTP1U_PORT);
+
+ err = udp_sock_create(gtp->net, &udp_conf, &sock1u);
+ if (err < 0)
+ return err;
+
+ udp_conf.local_udp_port = htons(GTP0_PORT);
+ err = udp_sock_create(gtp->net, &udp_conf, &sock0);
+ if (err < 0)
+ return err;
+
+ memset(&tunnel_cfg, 0, sizeof(tunnel_cfg));
+ tunnel_cfg.sk_user_data = gtp;
+ tunnel_cfg.encap_rcv = gtp_encap_recv;
+ tunnel_cfg.encap_destroy = gtp_encap_destroy;
+ tunnel_cfg.encap_type = UDP_ENCAP_GTP0;
+ setup_udp_tunnel_sock(net, sock0, &tunnel_cfg);
+
+ tunnel_cfg.encap_type = UDP_ENCAP_GTP1U;
+
+ setup_udp_tunnel_sock(net, sock1u, &tunnel_cfg);
+
+ sock_hold(sock0->sk);
+ sock_hold(sock1u->sk);
+
+ gtp->sk0 = sock0->sk;
+ gtp->sk1u = sock1u->sk;
+
+ return 0;
+}
+
+static int gtp_dev_stop(struct net_device *dev)
+{
+ struct gtp_dev *gtp = netdev_priv(dev);
+ struct sock *sk = gtp->sk1u;
+
+ udp_tunnel_sock_release(gtp->sk0->sk_socket);
+ udp_tunnel_sock_release(gtp->sk1u->sk_socket);
+
+ udp_sk(sk)->encap_type = 0;
+ rcu_assign_sk_user_data(sk, NULL);
+ sock_put(sk);
+
+ return 0;
+}
+
static const struct net_device_ops gtp_netdev_ops = {
.ndo_init = gtp_dev_init,
.ndo_uninit = gtp_dev_uninit,
+ .ndo_open = gtp_dev_open,
+ .ndo_stop = gtp_dev_stop,
.ndo_start_xmit = gtp_dev_xmit,
.ndo_get_stats64 = ip_tunnel_get_stats64,
};
@@ -672,10 +757,6 @@ static void gtp_link_setup(struct net_device *dev)
sizeof(struct gtp0_header);
}
-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 gtp_dev *gtp, struct nlattr *data[]);
-
static int gtp_newlink(struct net *src_net, struct net_device *dev,
struct nlattr *tb[], struct nlattr *data[],
struct netlink_ext_ack *extack)
@@ -780,6 +861,130 @@ static struct rtnl_link_ops gtp_link_ops __read_mostly = {
.fill_info = gtp_fill_info,
};
+static void init_tnl_info(struct ip_tunnel_info *info, __u16 dst_port)
+{
+ memset(info, 0, sizeof(*info));
+ info->key.tp_dst = htons(dst_port);
+}
+
+static struct gtp_dev *gtp_find_flow_based_dev(
+ struct net *net)
+{
+ struct gtp_net *gn = net_generic(net, gtp_net_id);
+ struct gtp_dev *gtp, *t = NULL;
+
+ list_for_each_entry(gtp, &gn->gtp_dev_list, list) {
+ if (gtp->collect_md)
+ t = gtp;
+ }
+
+ return t;
+}
+
+static int gtp_configure(struct net *net, struct net_device *dev,
+ const struct ip_tunnel_info *info)
+{
+ struct gtp_net *gn = net_generic(net, gtp_net_id);
+ struct gtp_dev *gtp = netdev_priv(dev);
+ int err;
+
+ gtp->net = net;
+ gtp->dev = dev;
+
+ if (gtp_find_flow_based_dev(net))
+ return -EBUSY;
+
+ dev->netdev_ops = >p_netdev_ops;
+ dev->priv_destructor = free_netdev;
+
+ dev->hard_header_len = 0;
+ dev->addr_len = 0;
+
+ /* Zero header length. */
+ dev->type = ARPHRD_NONE;
+ dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
+
+ dev->priv_flags |= IFF_NO_QUEUE;
+ dev->features |= NETIF_F_LLTX;
+ netif_keep_dst(dev);
+
+ /* Assume largest header, ie. GTPv0. */
+ dev->needed_headroom = LL_MAX_HEADER +
+ sizeof(struct iphdr) +
+ sizeof(struct udphdr) +
+ sizeof(struct gtp0_header);
+
+ dst_cache_reset(>p->info.dst_cache);
+ gtp->info = *info;
+ gtp->collect_md = true;
+
+ err = gtp_hashtable_new(gtp, GTP_PDP_HASHSIZE); // JO: when to free??
+ if (err < 0) {
+ pr_err("Error gtp_hashtable_new");
+ return err;
+ }
+
+ err = register_netdevice(dev);
+ if (err) {
+ pr_err("Error when registering net device");
+ return err;
+ }
+
+ list_add_rcu(>p->list, &gn->gtp_dev_list);
+ return 0;
+}
+
+struct net_device *gtp_create_flow_based_dev(struct net *net,
+ const char *name,
+ u8 name_assign_type,
+ u16 dst_port)
+{
+ struct nlattr *tb[IFLA_MAX + 1];
+ struct net_device *dev;
+ struct ip_tunnel_info info;
+ LIST_HEAD(list_kill);
+ int err;
+
+ memset(&tb, 0, sizeof(tb));
+ dev = rtnl_create_link(net, name, name_assign_type,
+ >p_link_ops, tb);
+ if (IS_ERR(dev)) {
+ pr_err("error rtnl_create_link");
+ return dev;
+ }
+
+ init_tnl_info(&info, dst_port);
+ err = gtp_configure(net, dev, &info);
+ if (err < 0) {
+ pr_err("error gtp_configure");
+ free_netdev(dev);
+ return ERR_PTR(err);
+ }
+
+ /* openvswitch users expect packet sizes to be unrestricted,
+ * so set the largest MTU we can.
+ */
+ err = gtp_change_mtu(dev, IP_MAX_MTU, false);
+ if (err) {
+ pr_err("error gtp_change_mtu");
+ goto err;
+ }
+
+ err = rtnl_configure_link(dev, NULL);
+ if (err < 0) {
+ pr_err("error rtnl_configure_link");
+ goto err;
+ }
+
+ return dev;
+
+err:
+ gtp_dellink(dev, &list_kill);
+ unregister_netdevice_many(&list_kill);
+ return ERR_PTR(err);
+}
+EXPORT_SYMBOL_GPL(gtp_create_flow_based_dev);
+
static int gtp_hashtable_new(struct gtp_dev *gtp, int hsize)
{
int i;
diff --git a/include/net/gtp.h b/include/net/gtp.h
index 6398891..a76b26c 100644
--- a/include/net/gtp.h
+++ b/include/net/gtp.h
@@ -31,4 +31,12 @@ struct gtp1_header { /* According to 3GPP TS 29.060. */
#define GTP1_F_EXTHDR 0x04
#define GTP1_F_MASK 0x07
+#ifdef CONFIG_INET
+
+struct net_device *gtp_create_flow_based_dev(
+ struct net *net, const char *name,
+ u8 name_assign_type, u16 dst_port);
+
+#endif /*ifdef CONFIG_INET */
+
#endif
--
2.9.3
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