[Devel] [PATCH DRAFT vz10 1/5] Revert "ve/net/gre: Disable ERSPAN support in ip_gre module"

[Konstantin Khorenko <khorenko@virtuozzo.com>]

This reverts commit a6adc8063402a38c6d951113453df6bf8ddcfb0e.

ERSPAN was disabled under CONFIG_VE because at the time it was not wired
into the per-Container GRE infrastructure: erspan devices did not set
NETIF_F_VIRTUAL, so register_netdevice() would reject them inside a CT,
and erspan_net_ops was not gated by any VE feature bit. Rather than
carry the feature permanently disabled, bring the code back so that the
following commit can properly containerize ERSPAN under a dedicated
VE feature bit.

https://virtuozzo.atlassian.net/browse/VSTOR-141173

Feature: net: disable ERSPAN support in ip_gre module
Signed-off-by: Konstantin Khorenko <khorenko@virtuozzo.com>
---
 net/ipv4/ip_gre.c | 33 ++++-----------------------------
 1 file changed, 4 insertions(+), 29 deletions(-)

diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c
index f618aae250334..d776eb8d9f76c 100644
--- a/net/ipv4/ip_gre.c
+++ b/net/ipv4/ip_gre.c
@@ -1134,7 +1134,6 @@ static int ipgre_tap_validate(struct nlattr *tb[], struct nlattr *data[],
 	return ipgre_tunnel_validate(tb, data, extack);
 }
 
-#ifndef CONFIG_VE
 static int erspan_validate(struct nlattr *tb[], struct nlattr *data[],
 			   struct netlink_ext_ack *extack)
 {
@@ -1174,7 +1173,6 @@ static int erspan_validate(struct nlattr *tb[], struct nlattr *data[],
 
 	return 0;
 }
-#endif
 
 static int ipgre_netlink_parms(struct net_device *dev,
 				struct nlattr *data[],
@@ -1245,7 +1243,6 @@ static int ipgre_netlink_parms(struct net_device *dev,
 	return 0;
 }
 
-#ifndef CONFIG_VE
 static int erspan_netlink_parms(struct net_device *dev,
 				struct nlattr *data[],
 				struct nlattr *tb[],
@@ -1289,7 +1286,6 @@ static int erspan_netlink_parms(struct net_device *dev,
 
 	return 0;
 }
-#endif
 
 /* This function returns true when ENCAP attributes are present in the nl msg */
 static bool ipgre_netlink_encap_parms(struct nlattr *data[],
@@ -1428,7 +1424,6 @@ static int ipgre_newlink(struct net *src_net, struct net_device *dev,
 	return ip_tunnel_newlink(dev, tb, &p, fwmark);
 }
 
-#ifndef CONFIG_VE
 static int erspan_newlink(struct net *src_net, struct net_device *dev,
 			  struct nlattr *tb[], struct nlattr *data[],
 			  struct netlink_ext_ack *extack)
@@ -1446,7 +1441,6 @@ static int erspan_newlink(struct net *src_net, struct net_device *dev,
 		return err;
 	return ip_tunnel_newlink(dev, tb, &p, fwmark);
 }
-#endif
 
 static int ipgre_changelink(struct net_device *dev, struct nlattr *tb[],
 			    struct nlattr *data[],
@@ -1477,7 +1471,6 @@ static int ipgre_changelink(struct net_device *dev, struct nlattr *tb[],
 	return 0;
 }
 
-#ifndef CONFIG_VE
 static int erspan_changelink(struct net_device *dev, struct nlattr *tb[],
 			     struct nlattr *data[],
 			     struct netlink_ext_ack *extack)
@@ -1504,7 +1497,6 @@ static int erspan_changelink(struct net_device *dev, struct nlattr *tb[],
 
 	return 0;
 }
-#endif
 
 static size_t ipgre_get_size(const struct net_device *dev)
 {
@@ -1602,7 +1594,6 @@ static int ipgre_fill_info(struct sk_buff *skb, const struct net_device *dev)
 	return -EMSGSIZE;
 }
 
-#ifndef CONFIG_VE
 static int erspan_fill_info(struct sk_buff *skb, const struct net_device *dev)
 {
 	struct ip_tunnel *t = netdev_priv(dev);
@@ -1643,7 +1634,6 @@ static void erspan_setup(struct net_device *dev)
 	ip_tunnel_setup(dev, erspan_net_id);
 	t->erspan_ver = 1;
 }
-#endif
 
 static const struct nla_policy ipgre_policy[IFLA_GRE_MAX + 1] = {
 	[IFLA_GRE_LINK]		= { .type = NLA_U32 },
@@ -1699,7 +1689,6 @@ static struct rtnl_link_ops ipgre_tap_ops __read_mostly = {
 	.get_link_net	= ip_tunnel_get_link_net,
 };
 
-#ifndef CONFIG_VE
 static struct rtnl_link_ops erspan_link_ops __read_mostly = {
 	.kind		= "erspan",
 	.maxtype	= IFLA_GRE_MAX,
@@ -1714,7 +1703,6 @@ static struct rtnl_link_ops erspan_link_ops __read_mostly = {
 	.fill_info	= erspan_fill_info,
 	.get_link_net	= ip_tunnel_get_link_net,
 };
-#endif
 
 struct net_device *gretap_fb_dev_create(struct net *net, const char *name,
 					u8 name_assign_type)
@@ -1786,7 +1774,6 @@ static struct pernet_operations ipgre_tap_net_ops = {
 	.size = sizeof(struct ip_tunnel_net),
 };
 
-#ifndef CONFIG_VE
 static int __net_init erspan_init_net(struct net *net)
 {
 	return ip_tunnel_init_net(net, erspan_net_id,
@@ -1806,7 +1793,6 @@ static struct pernet_operations erspan_net_ops = {
 	.id   = &erspan_net_id,
 	.size = sizeof(struct ip_tunnel_net),
 };
-#endif
 
 static int __init ipgre_init(void)
 {
@@ -1821,11 +1807,11 @@ static int __init ipgre_init(void)
 	err = register_pernet_device(&ipgre_tap_net_ops);
 	if (err < 0)
 		goto pnet_tap_failed;
-#ifndef CONFIG_VE
+
 	err = register_pernet_device(&erspan_net_ops);
 	if (err < 0)
 		goto pnet_erspan_failed;
-#endif
+
 	err = gre_add_protocol(&ipgre_protocol, GREPROTO_CISCO);
 	if (err < 0) {
 		pr_info("%s: can't add protocol\n", __func__);
@@ -1839,27 +1825,22 @@ static int __init ipgre_init(void)
 	err = rtnl_link_register(&ipgre_tap_ops);
 	if (err < 0)
 		goto tap_ops_failed;
-#ifndef CONFIG_VE
+
 	err = rtnl_link_register(&erspan_link_ops);
 	if (err < 0)
 		goto erspan_link_failed;
-#endif
 
 	return 0;
 
-#ifndef CONFIG_VE
 erspan_link_failed:
-#endif
 	rtnl_link_unregister(&ipgre_tap_ops);
 tap_ops_failed:
 	rtnl_link_unregister(&ipgre_link_ops);
 rtnl_link_failed:
 	gre_del_protocol(&ipgre_protocol, GREPROTO_CISCO);
 add_proto_failed:
-#ifndef CONFIG_VE
 	unregister_pernet_device(&erspan_net_ops);
 pnet_erspan_failed:
-#endif
 	unregister_pernet_device(&ipgre_tap_net_ops);
 pnet_tap_failed:
 	unregister_pernet_device(&ipgre_net_ops);
@@ -1870,15 +1851,11 @@ static void __exit ipgre_fini(void)
 {
 	rtnl_link_unregister(&ipgre_tap_ops);
 	rtnl_link_unregister(&ipgre_link_ops);
-#ifndef CONFIG_VE
 	rtnl_link_unregister(&erspan_link_ops);
-#endif
 	gre_del_protocol(&ipgre_protocol, GREPROTO_CISCO);
 	unregister_pernet_device(&ipgre_tap_net_ops);
 	unregister_pernet_device(&ipgre_net_ops);
-#ifndef CONFIG_VE
 	unregister_pernet_device(&erspan_net_ops);
-#endif
 }
 
 module_init(ipgre_init);
@@ -1887,9 +1864,7 @@ MODULE_DESCRIPTION("IPv4 GRE tunnels over IP library");
 MODULE_LICENSE("GPL");
 MODULE_ALIAS_RTNL_LINK("gre");
 MODULE_ALIAS_RTNL_LINK("gretap");
-#ifndef CONFIG_VE
 MODULE_ALIAS_RTNL_LINK("erspan");
-MODULE_ALIAS_NETDEV("erspan0");
-#endif
 MODULE_ALIAS_NETDEV("gre0");
 MODULE_ALIAS_NETDEV("gretap0");
+MODULE_ALIAS_NETDEV("erspan0");
-- 
2.43.0