4.16-stable review patch. If anyone has any objections, please let me know.
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From: William Tu u9012063@gmail.com
[ 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@gmail.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- 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; }