4.16-stable review patch. If anyone has any objections, please let me know.
------------------
From: William Tu <u9012063@xxxxxxxxx>
[ Upstream commit b80d0b93b991e551a32157e0d9d38fc5bc9348a7 ]
Currently ip6gre and ip6erspan share single metadata mode device,
using 'collect_md_tun'. Thus, when doing:
ip link add dev ip6gre11 type ip6gretap external
ip link add dev ip6erspan12 type ip6erspan external
RTNETLINK answers: File exists
simply fails due to the 2nd tries to create the same collect_md_tun.
The patch fixes it by adding a separate collect md tunnel device
for the ip6erspan, 'collect_md_tun_erspan'. As a result, a couple
of places need to refactor/split up in order to distinguish ip6gre
and ip6erspan.
First, move the collect_md check at ip6gre_tunnel_{unlink,link} and
create separate function {ip6gre,ip6ersapn}_tunnel_{link_md,unlink_md}.
Then before link/unlink, make sure the link_md/unlink_md is called.
Finally, a separate ndo_uninit is created for ip6erspan. Tested it
using the samples/bpf/test_tunnel_bpf.sh.
Fixes: ef7baf5e083c ("ip6_gre: add ip6 erspan collect_md mode")
Signed-off-by: William Tu <u9012063@xxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/ipv6/ip6_gre.c | 101 +++++++++++++++++++++++++++++++++++++++++------------
1 file changed, 79 insertions(+), 22 deletions(-)
--- a/net/ipv6/ip6_gre.c
+++ b/net/ipv6/ip6_gre.c
@@ -71,6 +71,7 @@ struct ip6gre_net {
struct ip6_tnl __rcu *tunnels[4][IP6_GRE_HASH_SIZE];
struct ip6_tnl __rcu *collect_md_tun;
+ struct ip6_tnl __rcu *collect_md_tun_erspan;
struct net_device *fb_tunnel_dev;
};
@@ -233,7 +234,12 @@ static struct ip6_tnl *ip6gre_tunnel_loo
if (cand)
return cand;
- t = rcu_dereference(ign->collect_md_tun);
+ if (gre_proto == htons(ETH_P_ERSPAN) ||
+ gre_proto == htons(ETH_P_ERSPAN2))
+ t = rcu_dereference(ign->collect_md_tun_erspan);
+ else
+ t = rcu_dereference(ign->collect_md_tun);
+
if (t && t->dev->flags & IFF_UP)
return t;
@@ -262,6 +268,31 @@ static struct ip6_tnl __rcu **__ip6gre_b
return &ign->tunnels[prio][h];
}
+static void ip6gre_tunnel_link_md(struct ip6gre_net *ign, struct ip6_tnl *t)
+{
+ if (t->parms.collect_md)
+ rcu_assign_pointer(ign->collect_md_tun, t);
+}
+
+static void ip6erspan_tunnel_link_md(struct ip6gre_net *ign, struct ip6_tnl *t)
+{
+ if (t->parms.collect_md)
+ rcu_assign_pointer(ign->collect_md_tun_erspan, t);
+}
+
+static void ip6gre_tunnel_unlink_md(struct ip6gre_net *ign, struct ip6_tnl *t)
+{
+ if (t->parms.collect_md)
+ rcu_assign_pointer(ign->collect_md_tun, NULL);
+}
+
+static void ip6erspan_tunnel_unlink_md(struct ip6gre_net *ign,
+ struct ip6_tnl *t)
+{
+ if (t->parms.collect_md)
+ rcu_assign_pointer(ign->collect_md_tun_erspan, NULL);
+}
+
static inline struct ip6_tnl __rcu **ip6gre_bucket(struct ip6gre_net *ign,
const struct ip6_tnl *t)
{
@@ -272,9 +303,6 @@ static void ip6gre_tunnel_link(struct ip
{
struct ip6_tnl __rcu **tp = ip6gre_bucket(ign, t);
- if (t->parms.collect_md)
- rcu_assign_pointer(ign->collect_md_tun, t);
-
rcu_assign_pointer(t->next, rtnl_dereference(*tp));
rcu_assign_pointer(*tp, t);
}
@@ -284,9 +312,6 @@ static void ip6gre_tunnel_unlink(struct
struct ip6_tnl __rcu **tp;
struct ip6_tnl *iter;
- if (t->parms.collect_md)
- rcu_assign_pointer(ign->collect_md_tun, NULL);
-
for (tp = ip6gre_bucket(ign, t);
(iter = rtnl_dereference(*tp)) != NULL;
tp = &iter->next) {
@@ -375,11 +400,23 @@ failed_free:
return NULL;
}
+static void ip6erspan_tunnel_uninit(struct net_device *dev)
+{
+ struct ip6_tnl *t = netdev_priv(dev);
+ struct ip6gre_net *ign = net_generic(t->net, ip6gre_net_id);
+
+ ip6erspan_tunnel_unlink_md(ign, t);
+ ip6gre_tunnel_unlink(ign, t);
+ dst_cache_reset(&t->dst_cache);
+ dev_put(dev);
+}
+
static void ip6gre_tunnel_uninit(struct net_device *dev)
{
struct ip6_tnl *t = netdev_priv(dev);
struct ip6gre_net *ign = net_generic(t->net, ip6gre_net_id);
+ ip6gre_tunnel_unlink_md(ign, t);
ip6gre_tunnel_unlink(ign, t);
dst_cache_reset(&t->dst_cache);
dev_put(dev);
@@ -1799,7 +1836,7 @@ static int ip6erspan_tap_init(struct net
static const struct net_device_ops ip6erspan_netdev_ops = {
.ndo_init = ip6erspan_tap_init,
- .ndo_uninit = ip6gre_tunnel_uninit,
+ .ndo_uninit = ip6erspan_tunnel_uninit,
.ndo_start_xmit = ip6erspan_tunnel_xmit,
.ndo_set_mac_address = eth_mac_addr,
.ndo_validate_addr = eth_validate_addr,
@@ -1862,8 +1899,6 @@ static int ip6gre_newlink_common(struct
struct netlink_ext_ack *extack)
{
struct ip6_tnl *nt;
- struct net *net = dev_net(dev);
- struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
struct ip_tunnel_encap ipencap;
int err;
@@ -1876,16 +1911,6 @@ static int ip6gre_newlink_common(struct
return err;
}
- ip6gre_netlink_parms(data, &nt->parms);
-
- if (nt->parms.collect_md) {
- if (rtnl_dereference(ign->collect_md_tun))
- return -EEXIST;
- } else {
- if (ip6gre_tunnel_find(net, &nt->parms, dev->type))
- return -EEXIST;
- }
-
if (dev->type == ARPHRD_ETHER && !tb[IFLA_ADDRESS])
eth_hw_addr_random(dev);
@@ -1909,12 +1934,26 @@ static int ip6gre_newlink(struct net *sr
struct nlattr *tb[], struct nlattr *data[],
struct netlink_ext_ack *extack)
{
- int err = ip6gre_newlink_common(src_net, dev, tb, data, extack);
struct ip6_tnl *nt = netdev_priv(dev);
struct net *net = dev_net(dev);
+ struct ip6gre_net *ign;
+ int err;
+
+ ip6gre_netlink_parms(data, &nt->parms);
+ ign = net_generic(net, ip6gre_net_id);
+
+ if (nt->parms.collect_md) {
+ if (rtnl_dereference(ign->collect_md_tun))
+ return -EEXIST;
+ } else {
+ if (ip6gre_tunnel_find(net, &nt->parms, dev->type))
+ return -EEXIST;
+ }
+ err = ip6gre_newlink_common(src_net, dev, tb, data, extack);
if (!err) {
ip6gre_tnl_link_config(nt, !tb[IFLA_MTU]);
+ ip6gre_tunnel_link_md(ign, nt);
ip6gre_tunnel_link(net_generic(net, ip6gre_net_id), nt);
}
return err;
@@ -1966,8 +2005,10 @@ static int ip6gre_changelink(struct net_
if (IS_ERR(t))
return PTR_ERR(t);
+ ip6gre_tunnel_unlink_md(ign, t);
ip6gre_tunnel_unlink(ign, t);
ip6gre_tnl_change(t, &p, !tb[IFLA_MTU]);
+ ip6gre_tunnel_link_md(ign, t);
ip6gre_tunnel_link(ign, t);
return 0;
}
@@ -2121,12 +2162,26 @@ static int ip6erspan_newlink(struct net
struct nlattr *tb[], struct nlattr *data[],
struct netlink_ext_ack *extack)
{
- int err = ip6gre_newlink_common(src_net, dev, tb, data, extack);
struct ip6_tnl *nt = netdev_priv(dev);
struct net *net = dev_net(dev);
+ struct ip6gre_net *ign;
+ int err;
+
+ ip6gre_netlink_parms(data, &nt->parms);
+ ign = net_generic(net, ip6gre_net_id);
+
+ if (nt->parms.collect_md) {
+ if (rtnl_dereference(ign->collect_md_tun_erspan))
+ return -EEXIST;
+ } else {
+ if (ip6gre_tunnel_find(net, &nt->parms, dev->type))
+ return -EEXIST;
+ }
+ err = ip6gre_newlink_common(src_net, dev, tb, data, extack);
if (!err) {
ip6erspan_tnl_link_config(nt, !tb[IFLA_MTU]);
+ ip6erspan_tunnel_link_md(ign, nt);
ip6gre_tunnel_link(net_generic(net, ip6gre_net_id), nt);
}
return err;
@@ -2158,8 +2213,10 @@ static int ip6erspan_changelink(struct n
if (IS_ERR(t))
return PTR_ERR(t);
+ ip6gre_tunnel_unlink_md(ign, t);
ip6gre_tunnel_unlink(ign, t);
ip6erspan_tnl_change(t, &p, !tb[IFLA_MTU]);
+ ip6erspan_tunnel_link_md(ign, t);
ip6gre_tunnel_link(ign, t);
return 0;
}
