[ovs-dev] [PATCH 8/8] net: ip6_gre: fix tunnel metadata device sharing.
Gregory Rose
gvrose8192 at gmail.com
Tue May 29 21:01:27 UTC 2018
On 5/29/2018 5:55 AM, William Tu wrote:
> commit b80d0b93b991e551a32157e0d9d38fc5bc9348a7
> Author: William Tu <u9012063 at gmail.com>
> Date: Fri May 18 19:22:28 2018 -0700
>
> net: ip6_gre: fix tunnel metadata device sharing.
>
> 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 at gmail.com>
> Signed-off-by: David S. Miller <davem at davemloft.net>
>
> Cc: Greg Rose <gvrose8192 at gmail.com>
> Signed-off-by: William Tu <u9012063 at gmail.com>
> ---
> datapath/linux/compat/ip6_gre.c | 116 +++++++++++++++++++++++++++++-----------
> 1 file changed, 86 insertions(+), 30 deletions(-)
>
> diff --git a/datapath/linux/compat/ip6_gre.c b/datapath/linux/compat/ip6_gre.c
> index 3a82c3d0fc6b..24e850a22266 100644
> --- a/datapath/linux/compat/ip6_gre.c
> +++ b/datapath/linux/compat/ip6_gre.c
> @@ -69,6 +69,7 @@ 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;
> };
>
> @@ -245,7 +246,12 @@ static struct ip6_tnl *ip6gre_tunnel_lookup(struct net_device *dev,
> 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;
>
> @@ -274,6 +280,31 @@ static struct ip6_tnl __rcu **__ip6gre_bucket(struct ip6gre_net *ign,
> 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)
> {
> @@ -284,9 +315,6 @@ static void ip6gre_tunnel_link(struct ip6gre_net *ign, struct ip6_tnl *t)
> {
> 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);
> }
> @@ -296,9 +324,6 @@ static void ip6gre_tunnel_unlink(struct ip6gre_net *ign, struct ip6_tnl *t)
> 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) {
> @@ -385,11 +410,23 @@ 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);
> @@ -2032,7 +2069,7 @@ static int ip6erspan_tap_init(struct net_device *dev)
>
> 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,
> @@ -2107,8 +2144,6 @@ static int rpl_ip6gre_newlink_common(struct net *src_net, struct net_device *dev
> #endif
> {
> 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;
>
> @@ -2121,16 +2156,6 @@ static int rpl_ip6gre_newlink_common(struct net *src_net, struct net_device *dev
> 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);
>
> @@ -2160,17 +2185,30 @@ static int rpl_ip6gre_newlink(struct net *src_net, struct net_device *dev,
> struct nlattr *tb[], struct nlattr *data[])
> #endif
> {
> + 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;
> + }
>
> #ifdef HAVE_IP6GRE_EXTACK
> - int err = ip6gre_newlink_common(src_net, dev, tb, data, extack);
> + err = ip6gre_newlink_common(src_net, dev, tb, data, extack);
> #else
> - int err = ip6gre_newlink_common(src_net, dev, tb, data);
> + err = ip6gre_newlink_common(src_net, dev, tb, data);
> #endif
> - struct ip6_tnl *nt = netdev_priv(dev);
> - struct net *net = dev_net(dev);
> -
> 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;
> @@ -2240,8 +2278,10 @@ static int rpl_ip6gre_changelink(struct net_device *dev, struct nlattr *tb[],
> 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;
> }
> @@ -2405,16 +2445,30 @@ static int rpl_ip6erspan_newlink(struct net *src_net, struct net_device *dev,
> struct nlattr *tb[], struct nlattr *data[])
> #endif
> {
> -#ifdef HAVE_IP6GRE_EXTACK
> - int err = ip6gre_newlink_common(src_net, dev, tb, data, extack);
> -#else
> - int err = ip6gre_newlink_common(src_net, dev, tb, data);
> -#endif
> 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;
> + }
> +
> +#ifdef HAVE_IP6GRE_EXTACK
> + err = ip6gre_newlink_common(src_net, dev, tb, data, extack);
> +#else
> + err = ip6gre_newlink_common(src_net, dev, tb, data);
> +#endif
> 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;
> @@ -2455,8 +2509,10 @@ static int rpl_ip6erspan_changelink(struct net_device *dev, struct nlattr *tb[],
> 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;
> }
The patch seems fine but I still have problems with ip6gre and ip6erspan
tunnels co-existing.
Thanks,
- Greg
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