Message-ID: <CAOrHB_CMGGMzrSUrfRxbTcmJhH+MtzpUHQDz8DaJB=cOAto4kg@mail.gmail.com>
Date:   Thu, 25 Jan 2018 09:32:14 -0800
From:   Pravin Shelar <pshelar@....org>
To:     William Tu <u9012063@...il.com>
Cc:     Linux Kernel Network Developers <netdev@...r.kernel.org>
Subject: Re: [PATCHv5 net-next 2/2] openvswitch: add erspan version I and II support

On Wed, Jan 24, 2018 at 11:06 AM, William Tu <u9012063@...il.com> wrote:
> The patch adds support for openvswitch to configure erspan
> v1 and v2.  The OVS_TUNNEL_KEY_ATTR_ERSPAN_OPTS attr is added
> to uapi as a binary blob to support all ERSPAN v1 and v2's
> fields.  Note that Previous commit "openvswitch: Add erspan tunnel
> support." was reverted since it does not design properly.
>
> Signed-off-by: William Tu <u9012063@...il.com>
> ---
>  include/uapi/linux/openvswitch.h |  2 +-
>  net/openvswitch/flow_netlink.c   | 90 +++++++++++++++++++++++++++++++++++++++-
>  2 files changed, 90 insertions(+), 2 deletions(-)
>
> diff --git a/include/uapi/linux/openvswitch.h b/include/uapi/linux/openvswitch.h
> index dcfab5e3b55c..158c2e45c0a5 100644
> --- a/include/uapi/linux/openvswitch.h
> +++ b/include/uapi/linux/openvswitch.h
> @@ -273,7 +273,6 @@ enum {
>
>  #define OVS_VXLAN_EXT_MAX (__OVS_VXLAN_EXT_MAX - 1)
>
> -
>  /* OVS_VPORT_ATTR_OPTIONS attributes for tunnels.
>   */
>  enum {
> @@ -363,6 +362,7 @@ enum ovs_tunnel_key_attr {
>         OVS_TUNNEL_KEY_ATTR_IPV6_SRC,           /* struct in6_addr src IPv6 address. */
>         OVS_TUNNEL_KEY_ATTR_IPV6_DST,           /* struct in6_addr dst IPv6 address. */
>         OVS_TUNNEL_KEY_ATTR_PAD,
> +       OVS_TUNNEL_KEY_ATTR_ERSPAN_OPTS,        /* struct erspan_metadata */
>         __OVS_TUNNEL_KEY_ATTR_MAX
>  };
>
Since this is uapi, we need to define the struct erspan_metadata in a
UAPI header file.

Also lets move field 'version' to the begining of the struct for easy
expansion later.
struct erspan_metadata {
        int version;
        union {
                __be32 index;           /* Version 1 (type II)*/
                struct erspan_md2 md2;  /* Version 2 (type III) */
        } u;
};

> diff --git a/net/openvswitch/flow_netlink.c b/net/openvswitch/flow_netlink.c
> index f143908b651d..9d00c24b2836 100644
> --- a/net/openvswitch/flow_netlink.c
> +++ b/net/openvswitch/flow_netlink.c
> @@ -49,6 +49,7 @@
>  #include <net/mpls.h>
>  #include <net/vxlan.h>
>  #include <net/tun_proto.h>
> +#include <net/erspan.h>
>
>  #include "flow_netlink.h"
>
> @@ -329,7 +330,8 @@ size_t ovs_tun_key_attr_size(void)
>                 + nla_total_size(0)    /* OVS_TUNNEL_KEY_ATTR_CSUM */
>                 + nla_total_size(0)    /* OVS_TUNNEL_KEY_ATTR_OAM */
>                 + nla_total_size(256)  /* OVS_TUNNEL_KEY_ATTR_GENEVE_OPTS */
> -               /* OVS_TUNNEL_KEY_ATTR_VXLAN_OPTS is mutually exclusive with
> +               /* OVS_TUNNEL_KEY_ATTR_VXLAN_OPTS and
> +                * OVS_TUNNEL_KEY_ATTR_ERSPAN_OPTS is mutually exclusive with
>                  * OVS_TUNNEL_KEY_ATTR_GENEVE_OPTS and covered by it.
>                  */
>                 + nla_total_size(2)    /* OVS_TUNNEL_KEY_ATTR_TP_SRC */
> @@ -400,6 +402,7 @@ static const struct ovs_len_tbl ovs_tunnel_key_lens[OVS_TUNNEL_KEY_ATTR_MAX + 1]
>                                                 .next = ovs_vxlan_ext_key_lens },
>         [OVS_TUNNEL_KEY_ATTR_IPV6_SRC]      = { .len = sizeof(struct in6_addr) },
>         [OVS_TUNNEL_KEY_ATTR_IPV6_DST]      = { .len = sizeof(struct in6_addr) },
> +       [OVS_TUNNEL_KEY_ATTR_ERSPAN_OPTS]   = { .len = OVS_ATTR_VARIABLE },
>  };
>
>  static const struct ovs_len_tbl
> @@ -631,6 +634,33 @@ static int vxlan_tun_opt_from_nlattr(const struct nlattr *attr,
>         return 0;
>  }
>
> +static int erspan_tun_opt_from_nlattr(const struct nlattr *a,
> +                                     struct sw_flow_match *match, bool is_mask,
> +                                     bool log)
> +{
> +       unsigned long opt_key_offset;
> +
> +       BUILD_BUG_ON(sizeof(struct erspan_metadata) >
> +                    sizeof(match->key->tun_opts));
> +
> +       if (nla_len(a) > sizeof(match->key->tun_opts)) {
> +               OVS_NLERR(log, "ERSPAN option length err (len %d, max %zu).",
> +                         nla_len(a), sizeof(match->key->tun_opts));
> +               return -EINVAL;
> +       }
> +
> +       if (!is_mask)
> +               SW_FLOW_KEY_PUT(match, tun_opts_len,
> +                               sizeof(struct erspan_metadata), false);
> +       else
> +               SW_FLOW_KEY_PUT(match, tun_opts_len, 0xff, true);
> +
> +       opt_key_offset = TUN_METADATA_OFFSET(nla_len(a));
> +       SW_FLOW_KEY_MEMCPY_OFFSET(match, opt_key_offset, nla_data(a),
> +                                 nla_len(a), is_mask);
> +       return 0;
> +}
> +
...
> @@ -2461,6 +2509,41 @@ static int validate_geneve_opts(struct sw_flow_key *key)
>         return 0;
>  }
>
> +static int validate_erspan_opts(struct sw_flow_key *key, bool log)
> +{
I do not see any need to validate ERSPAN key values, except the total
len, which should be less than 255.

> +
>  static int validate_and_copy_set_tun(const struct nlattr *attr,
>                                      struct sw_flow_actions **sfa, bool log)
>  {
> @@ -2486,6 +2569,11 @@ static int validate_and_copy_set_tun(const struct nlattr *attr,
>                         break;
>                 case OVS_TUNNEL_KEY_ATTR_VXLAN_OPTS:
>                         break;
> +               case OVS_TUNNEL_KEY_ATTR_ERSPAN_OPTS:
> +                       err = validate_erspan_opts(&key, log);
> +                       if (err < 0)
> +                               return err;
> +                       break;
>                 }
>         };
>
> --
> 2.7.4
>

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