[ovs-dev] [PATCH] compat: Allow IPv6 GRE/ERSPAN Tx when ip6_gre is loaded
Gregory Rose
gvrose8192 at gmail.com
Fri Jul 27 15:56:02 UTC 2018
On 7/27/2018 2:22 AM, William Tu wrote:
>
>
> On Thu, Jul 26, 2018 at 9:11 AM, Greg Rose <gvrose8192 at gmail.com
> <mailto:gvrose8192 at gmail.com>> wrote:
>
> When for some reason the built-in kernel ip6_gre module is loaded that
> would prevent the openvswitch kernel driver from loading. Even when
> the built-in kernel ip6_gre module is loaded we can still perform
> port mirroring via Tx. Adjust the error handling and detect when
> the ip6_gre kernel module is loaded and in that case still enable
> IPv6 GRE/ERSPAN Tx.
>
> Signed-off-by: Greg Rose <gvrose8192 at gmail.com
> <mailto:gvrose8192 at gmail.com>>
> ---
> datapath/linux/compat/ip6_gre.c | 39
> +++++++++++++++++++++++++++++++++------
> datapath/vport.c | 17 +++++++++++++++--
> 2 files changed, 48 insertions(+), 8 deletions(-)
>
> diff --git a/datapath/linux/compat/ip6_gre.c
> b/datapath/linux/compat/ip6_gre.c
> index 0c88547..f532f21 100644
> --- a/datapath/linux/compat/ip6_gre.c
> +++ b/datapath/linux/compat/ip6_gre.c
> @@ -65,6 +65,7 @@
> #define IP6_GRE_HASH_SIZE (1 << IP6_GRE_HASH_SIZE_SHIFT)
>
> static unsigned int ip6gre_net_id __read_mostly;
> +static bool ip6_gre_loaded = false;
> struct ip6gre_net {
> struct ip6_tnl __rcu *tunnels[4][IP6_GRE_HASH_SIZE];
>
> @@ -2792,19 +2793,43 @@ int rpl_ip6gre_init(void)
> int err;
>
> err = register_pernet_device(&ip6gre_net_ops);
> - if (err < 0)
> - return err;
> + if (err < 0) {
> + if (err == -EEXIST)
> + goto ip6_gre_loaded;
> + else
> + goto out;
> + }
>
> err = inet6_add_protocol(&ip6gre_protocol, IPPROTO_GRE);
> if (err < 0) {
> pr_info("%s: can't add protocol\n", __func__);
> - goto add_proto_failed;
> + if (err == -EBUSY) {
>
>
> inet6_add_protocol returns -1 when there already a protocol registered.
Good catch - in practical terms it never got there anyway if ip6_gre was
loaded but we obviously can't
always count on that!
>
> + goto ip6_gre_loaded;
> + } else {
> + goto add_proto_failed;
> + }
> }
>
> pr_info("GRE over IPv6 tunneling driver\n");
> ovs_vport_ops_register(&ovs_ip6gre_vport_ops);
> ovs_vport_ops_register(&ovs_erspan6_vport_ops);
> - return 0;
> + return err;
> +
> +ip6_gre_loaded:
> + /* Since GRE only allows single receiver to be registerd,
> + * we skip here so only gre transmit works, see:
> + *
> + * commit 9f57c67c379d88a10e8ad676426fee5ae7341b14
>
>
> This commit is for ipv4 gre.
> IPv6 gre is commit f9242b6b28d61
> (David S. Miller 2012-06-19 18:56:21 -0700 34) return
> !cmpxchg((const struct inet6_protocol
OK, I'll fix that up.
> **)&inet6_protos[protocol],
>
> + * Author: Pravin B Shelar <pshelar at nicira.com
> <mailto:pshelar at nicira.com>>
> + * Date: Fri Aug 7 23:51:52 2015 -0700
> + * gre: Remove support for sharing GRE protocol hook
> + *
> + * OVS GRE receive part is disabled.
> + */
>
>
> Others look good to me!
> Thanks for the patch
V2 will be out in a bit.
Thanks for the review!
- Greg
>
> William
>
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