[ovs-dev] [PATCH net-next V18 3/3] 802.1AD: Flow handling, actions, vlan parsing and netlink attributes

Pravin Shelar pshelar at nicira.com
Tue Oct 27 02:10:19 UTC 2015


On Sun, Oct 25, 2015 at 5:11 PM, Thomas F Herbert
<thomasfherbert at gmail.com> wrote:
> Add support for 802.1ad including the ability to push and pop double
> tagged vlans. Add support for 802.1ad to netlink parsing and flow
> conversion. Uses double nested encap attributes to represent double
> tagged vlan. Inner TPID encoded along with ctci in nested attributes. Outer
> TPID is also encoded in the flow key.
>
> Signed-off-by: Thomas F Herbert <thomasfherbert at gmail.com>
This patch does not apply on current master due to conflicts related
net-branch merge.

> ---
>  net/openvswitch/actions.c      |   6 +-
>  net/openvswitch/flow.c         |  76 ++++++++++++----
>  net/openvswitch/flow.h         |   8 +-
>  net/openvswitch/flow_netlink.c | 199 +++++++++++++++++++++++++++++++++++++----
>  net/openvswitch/vport-netdev.c |   4 +-
>  5 files changed, 252 insertions(+), 41 deletions(-)
>
> diff --git a/net/openvswitch/flow.c b/net/openvswitch/flow.c
> index c8db44a..ed19e2b 100644
> --- a/net/openvswitch/flow.c
> +++ b/net/openvswitch/flow.c
> @@ -302,24 +302,68 @@ static bool icmp6hdr_ok(struct sk_buff *skb)
>                                   sizeof(struct icmp6hdr));
>  }
>
> -static int parse_vlan(struct sk_buff *skb, struct sw_flow_key *key)
> +/* Parse vlan tag from vlan header.
> + * Returns ERROR on memory error.
> + * Returns 0 if it encounters a non-vlan or incomplete packet.
> + * Returns 1 after successfully parsing vlan tag.
> + */
> +
> +static int parse_vlan_tag(struct sk_buff *skb, struct vlan_head *vlan)
>  {
> -       struct qtag_prefix {
> -               __be16 eth_type; /* ETH_P_8021Q */
> -               __be16 tci;
> -       };
> -       struct qtag_prefix *qp;
> +       struct vlan_head *qp = (struct vlan_head *)skb->data;
> +
> +       if (likely(!eth_type_vlan(qp->tpid)))
> +               return 0;
>
> -       if (unlikely(skb->len < sizeof(struct qtag_prefix) + sizeof(__be16)))
> +       if (unlikely(skb->len < sizeof(struct vlan_head) + sizeof(__be16)))
>                 return 0;
Why do we need extra sizeof(__be16) bytes here?

>
> -       if (unlikely(!pskb_may_pull(skb, sizeof(struct qtag_prefix) +
> -                                        sizeof(__be16))))
> +       if (unlikely(!pskb_may_pull(skb, sizeof(struct vlan_head) +
> +                                sizeof(__be16))))
>                 return -ENOMEM;
>
> -       qp = (struct qtag_prefix *) skb->data;
> -       key->eth.tci = qp->tci | htons(VLAN_TAG_PRESENT);
> -       __skb_pull(skb, sizeof(struct qtag_prefix));
> +       vlan->tci = qp->tci | htons(VLAN_TAG_PRESENT);
> +       vlan->tpid = qp->tpid;
> +
> +       __skb_pull(skb, sizeof(struct vlan_head));
> +       return 1;
> +}
> +
...

> diff --git a/net/openvswitch/flow_netlink.c b/net/openvswitch/flow_netlink.c
> index c92d6a2..7e90f8c 100644
> --- a/net/openvswitch/flow_netlink.c
> +++ b/net/openvswitch/flow_netlink.c
...

> +
> +static int parse_vlan_from_nlattrs(const struct nlattr **nla,
> +                                  struct sw_flow_match *match,
> +                                  u64 *key_attrs, bool *ie_valid,
> +                                  const struct nlattr **a, bool is_mask,
> +                                  bool log)
> +{
> +       int err;
> +       const struct nlattr *encap;
> +       u64 v_attrs = 0;
> +
> +       if (!is_mask) {
> +               err = __parse_vlan_from_nlattrs(nla, match, key_attrs,
> +                                               false, a, is_mask, log);
> +               if (err)
> +                       return err;
> +
> +               /* Another encap attribute here indicates
> +                * the presence of a double tagged vlan.
> +                */
> +               encap = a[OVS_KEY_ATTR_ENCAP];
> +
> +               err = parse_flow_nlattrs(encap, a, &v_attrs, log);
> +               if (err)
> +                       return err;
> +
> +               if ((v_attrs & (1 << OVS_KEY_ATTR_ETHERTYPE)) &&
> +                   eth_type_vlan(nla_get_be16(a[OVS_KEY_ATTR_ETHERTYPE]))) {
> +                       if (!((v_attrs & (1 << OVS_KEY_ATTR_VLAN)) &&
> +                             (v_attrs & (1 << OVS_KEY_ATTR_ENCAP)))) {
> +                               OVS_NLERR(log, "Invalid Inner VLAN frame");
> +                               return -EINVAL;
> +                       }
> +                       *ie_valid = true;
> +                       err = __parse_vlan_from_nlattrs(&encap, match, &v_attrs,
> +                                                       true, a, is_mask, log);
> +                       if (err)
> +                               return err;
> +                       *key_attrs |= v_attrs;
> +               }
> +       } else {
> +               err = __parse_vlan_from_nlattrs(nla, match, key_attrs,
> +                                               false, a, is_mask, log);
> +               if (err)
> +                       return err;
> +
> +               encap = a[OVS_KEY_ATTR_ENCAP];
> +
> +               err = parse_flow_nlattrs(encap, a, &v_attrs, log);
> +               if (err)
> +                       return err;
> +
> +               if (v_attrs & 1 << OVS_KEY_ATTR_ENCAP) {
Missing  parentheses

...
> @@ -1099,25 +1240,27 @@ int ovs_nla_get_match(struct net *net, struct sw_flow_match *match,
>
>         if ((key_attrs & (1 << OVS_KEY_ATTR_ETHERNET)) &&
>             (key_attrs & (1 << OVS_KEY_ATTR_ETHERTYPE)) &&
> -           (nla_get_be16(a[OVS_KEY_ATTR_ETHERTYPE]) == htons(ETH_P_8021Q))) {
> +           eth_type_vlan(nla_get_be16(a[OVS_KEY_ATTR_ETHERTYPE]))) {
>                 __be16 tci;
>
> -               if (!((key_attrs & (1 << OVS_KEY_ATTR_VLAN)) &&
> -                     (key_attrs & (1 << OVS_KEY_ATTR_ENCAP)))) {
> +               if (!((key_attrs & (1ULL << OVS_KEY_ATTR_VLAN)) &&
> +                     (key_attrs & (1ULL << OVS_KEY_ATTR_ENCAP)))) {
This is not required change.

>                         OVS_NLERR(log, "Invalid Vlan frame.");
>                         return -EINVAL;
>                 }
>
> -               key_attrs &= ~(1 << OVS_KEY_ATTR_ETHERTYPE);
>                 tci = nla_get_be16(a[OVS_KEY_ATTR_VLAN]);
>                 encap = a[OVS_KEY_ATTR_ENCAP];
> -               key_attrs &= ~(1 << OVS_KEY_ATTR_ENCAP);
>                 encap_valid = true;
>
>                 if (tci & htons(VLAN_TAG_PRESENT)) {
After checks in encode_vlan_from_nlattrs() function there is no need
to have checks here.

> -                       err = parse_flow_nlattrs(encap, a, &key_attrs, log);
> +                       err = parse_vlan_from_nlattrs(&encap, match,
> +                                                     &key_attrs,
> +                                                     &i_encap_valid, a, false,
> +                                                     log);
>                         if (err)
>                                 return err;
> +
Added white space.
>                 } else if (!tci) {
>                         /* Corner case for truncated 802.1Q header. */
>                         if (nla_len(encap)) {
> @@ -1169,7 +1312,7 @@ int ovs_nla_get_match(struct net *net, struct sw_flow_match *match,
>                         goto free_newmask;
>
>                 /* Always match on tci. */
> -               SW_FLOW_KEY_PUT(match, eth.tci, htons(0xffff), true);
> +               SW_FLOW_KEY_PUT(match, eth.vlan.tci, htons(0xffff), true);
Also need to exact match on inner tci.

>
>                 if (mask_attrs & 1 << OVS_KEY_ATTR_ENCAP) {
>                         __be16 eth_type = 0;
> @@ -1188,10 +1331,13 @@ int ovs_nla_get_match(struct net *net, struct sw_flow_match *match,
>                         if (eth_type == htons(0xffff)) {
Same as above, after checks in encode_vlan_from_nlattrs() these checks
looks redundant.

>                                 mask_attrs &= ~(1 << OVS_KEY_ATTR_ETHERTYPE);
>                                 encap = a[OVS_KEY_ATTR_ENCAP];
> -                               err = parse_flow_mask_nlattrs(encap, a,
> -                                                             &mask_attrs, log);
> +                               err = parse_vlan_from_nlattrs(&nla_mask, match,
> +                                                             &mask_attrs,
> +                                                             &i_encap_valid,
> +                                                             a, true, log);
>                                 if (err)
>                                         goto free_newmask;
> +
>                         } else {
>                                 OVS_NLERR(log, "VLAN frames must have an exact match on the TPID (mask=%x).",
>                                           ntohs(eth_type));
...
> @@ -1368,17 +1515,29 @@ static int __ovs_nla_put_key(const struct sw_flow_key *swkey,
>         ether_addr_copy(eth_key->eth_src, output->eth.src);
>         ether_addr_copy(eth_key->eth_dst, output->eth.dst);
>
> -       if (swkey->eth.tci || swkey->eth.type == htons(ETH_P_8021Q)) {
> -               __be16 eth_type;
> -               eth_type = !is_mask ? htons(ETH_P_8021Q) : htons(0xffff);
> -               if (nla_put_be16(skb, OVS_KEY_ATTR_ETHERTYPE, eth_type) ||
> -                   nla_put_be16(skb, OVS_KEY_ATTR_VLAN, output->eth.tci))
> +       if (swkey->eth.vlan.tci || eth_type_vlan(swkey->eth.type)) {
> +               if (nla_put_be16(skb, OVS_KEY_ATTR_ETHERTYPE,
> +                                output->eth.vlan.tpid) ||
> +                   nla_put_be16(skb, OVS_KEY_ATTR_VLAN, output->eth.vlan.tci))
>                         goto nla_put_failure;
>                 encap = nla_nest_start(skb, OVS_KEY_ATTR_ENCAP);
> -               if (!swkey->eth.tci)
> +               if (!swkey->eth.vlan.tci)
>                         goto unencap;
> -       } else
> +               if (swkey->eth.cvlan.tci) {
> +                       /* Customer tci is nested but uses same key attribute.
> +                        */
> +                       if (nla_put_be16(skb, OVS_KEY_ATTR_ETHERTYPE,
> +                                        output->eth.cvlan.tpid) ||
> +                           nla_put_be16(skb, OVS_KEY_ATTR_VLAN,
> +                                        output->eth.cvlan.tci))
> +                               goto nla_put_failure;
> +                       in_encap = nla_nest_start(skb, OVS_KEY_ATTR_ENCAP);
> +                       if (!swkey->eth.cvlan.tci)
> +                               goto unencap;
(!swkey->eth.cvlan.tci) is never going to be true. since inside if
(swkey->eth.cvlan.tci) block.



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