[ovs-dev] [PATCH v4 5/7] datapath: Split ovs_flow_cmd_new_or_set().

Pravin Shelar pshelar at nicira.com
Tue Mar 25 17:11:06 UTC 2014


On Mon, Mar 24, 2014 at 11:56 AM, Jarno Rajahalme <jrajahalme at nicira.com> wrote:
> Following patch will be easier to reason about with separate
> ovs_flow_cmd_new() and ovs_flow_cmd_set() functions.
>
> Signed-off-by: Jarno Rajahalme <jrajahalme at nicira.com>
> ---
>  datapath/datapath.c |  168 ++++++++++++++++++++++++++++++++++++---------------
>  1 file changed, 118 insertions(+), 50 deletions(-)
>
> diff --git a/datapath/datapath.c b/datapath/datapath.c
> index e7cfd40..809a9c4 100644
> --- a/datapath/datapath.c
> +++ b/datapath/datapath.c
> @@ -784,16 +784,16 @@ static struct sk_buff *ovs_flow_cmd_build_info(struct sw_flow *flow,
>         return skb;
>  }
>
> -static int ovs_flow_cmd_new_or_set(struct sk_buff *skb, struct genl_info *info)
> +static int ovs_flow_cmd_new(struct sk_buff *skb, struct genl_info *info)
>  {
>         struct nlattr **a = info->attrs;
>         struct ovs_header *ovs_header = info->userhdr;
>         struct sw_flow_key key, masked_key;
> -       struct sw_flow *flow = NULL;
> +       struct sw_flow *flow;
>         struct sw_flow_mask mask;
>         struct sk_buff *reply = NULL;
>         struct datapath *dp;
> -       struct sw_flow_actions *acts = NULL;
> +       struct sw_flow_actions *acts;
>         struct sw_flow_match match;
>         int error;
>
> @@ -809,23 +809,21 @@ static int ovs_flow_cmd_new_or_set(struct sk_buff *skb, struct genl_info *info)
>                 goto error;
>
>         /* Validate actions. */
> -       if (a[OVS_FLOW_ATTR_ACTIONS]) {
> -               acts = ovs_nla_alloc_flow_actions(nla_len(a[OVS_FLOW_ATTR_ACTIONS]));
> -               error = PTR_ERR(acts);
> -               if (IS_ERR(acts))
> -                       goto error;
> +       error = -EINVAL;
No need to set error again.

> +       if (!a[OVS_FLOW_ATTR_ACTIONS])
> +               goto error;
>
> -               ovs_flow_mask_key(&masked_key, &key, &mask);
> -               error = ovs_nla_copy_actions(a[OVS_FLOW_ATTR_ACTIONS],
> -                                            &masked_key, 0, &acts);
> -               if (error) {
> -                       OVS_NLERR("Flow actions may not be safe on all matching packets.\n");
> -                       goto err_kfree;
> -               }
> -       } else if (info->genlhdr->cmd == OVS_FLOW_CMD_NEW) {
> -               /* OVS_FLOW_CMD_NEW must have actions. */
> -               error = -EINVAL;
> +       acts = ovs_nla_alloc_flow_actions(nla_len(a[OVS_FLOW_ATTR_ACTIONS]));
> +       error = PTR_ERR(acts);
> +       if (IS_ERR(acts))
>                 goto error;
> +
> +       ovs_flow_mask_key(&masked_key, &key, &mask);
> +       error = ovs_nla_copy_actions(a[OVS_FLOW_ATTR_ACTIONS],
> +                                    &masked_key, 0, &acts);
> +       if (error) {
> +               OVS_NLERR("Flow actions may not be safe on all matching packets.\n");
> +               goto err_kfree;
>         }
>
>         ovs_lock();
> @@ -837,11 +835,6 @@ static int ovs_flow_cmd_new_or_set(struct sk_buff *skb, struct genl_info *info)
>         /* Check if this is a duplicate flow */
>         flow = ovs_flow_tbl_lookup(&dp->table, &key);
>         if (!flow) {
> -               /* Bail out if we're not allowed to create a new flow. */
> -               error = -ENOENT;
> -               if (info->genlhdr->cmd == OVS_FLOW_CMD_SET)
> -                       goto err_unlock_ovs;
> -
>                 /* Allocate flow. */
>                 flow = ovs_flow_alloc();
>                 if (IS_ERR(flow)) {
> @@ -858,14 +851,9 @@ static int ovs_flow_cmd_new_or_set(struct sk_buff *skb, struct genl_info *info)
>                 error = ovs_flow_tbl_insert(&dp->table, flow, &mask);
>                 if (error)
>                         goto err_flow_free;
> -
> -               if (ovs_must_build_reply(info, &ovs_dp_flow_multicast_group))
> -                       reply = ovs_flow_cmd_build_info(flow,
> -                                                       ovs_header->dp_ifindex,
> -                                                       info,
> -                                                       OVS_FLOW_CMD_NEW);
>         } else {
> -               /* We found a matching flow. */
> +               struct sw_flow_actions *old_acts;
> +
>                 /* Bail out if we're not allowed to modify an existing flow.
>                  * We accept NLM_F_CREATE in place of the intended NLM_F_EXCL
>                  * because Generic Netlink treats the latter as a dump
> @@ -873,33 +861,115 @@ static int ovs_flow_cmd_new_or_set(struct sk_buff *skb, struct genl_info *info)
>                  * gets fixed.
>                  */
>                 error = -EEXIST;
> -               if (info->genlhdr->cmd == OVS_FLOW_CMD_NEW &&
> -                   info->nlhdr->nlmsg_flags & (NLM_F_CREATE | NLM_F_EXCL))
> +               if (info->nlhdr->nlmsg_flags & (NLM_F_CREATE | NLM_F_EXCL))
>                         goto err_unlock_ovs;
>
>                 /* The unmasked key has to be the same for flow updates. */
>                 if (!ovs_flow_cmp_unmasked_key(flow, &match))
>                         goto err_unlock_ovs;
>
> -               /* Update actions, if present. */
> -               if (acts) {
> -                       struct sw_flow_actions *old_acts;
> +               /* Update actions. */
> +               old_acts = ovsl_dereference(flow->sf_acts);
> +               rcu_assign_pointer(flow->sf_acts, acts);
> +               ovs_nla_free_flow_actions(old_acts);
> +       }
> +
> +       if (ovs_must_build_reply(info, &ovs_dp_flow_multicast_group))
> +               reply = ovs_flow_cmd_build_info(flow, ovs_header->dp_ifindex,
> +                                               info, OVS_FLOW_CMD_NEW);
> +       ovs_unlock();
> +
> +       if (reply) {
> +               if (!IS_ERR(reply))
> +                       ovs_notify(reply, info, &ovs_dp_flow_multicast_group);
> +               else
> +                       netlink_set_err(sock_net(skb->sk)->genl_sock, 0,
> +                                       ovs_dp_flow_multicast_group.id,
> +                                       PTR_ERR(reply));
> +       }
> +       return 0;
> +
> +err_flow_free:
> +       ovs_flow_free(flow, false);
> +err_unlock_ovs:
> +       ovs_unlock();
> +err_kfree:
> +       kfree(acts);
> +error:
> +       return error;
> +}
> +
> +static int ovs_flow_cmd_set(struct sk_buff *skb, struct genl_info *info)
> +{
> +       struct nlattr **a = info->attrs;
> +       struct ovs_header *ovs_header = info->userhdr;
> +       struct sw_flow_key key, masked_key;
> +       struct sw_flow *flow;
> +       struct sw_flow_mask mask;
> +       struct sk_buff *reply = NULL;
> +       struct datapath *dp;
> +       struct sw_flow_actions *acts = NULL;
> +       struct sw_flow_match match;
> +       int error;
> +
> +       /* Extract key. */
> +       error = -EINVAL;
> +       if (!a[OVS_FLOW_ATTR_KEY])
> +               goto error;
> +
> +       ovs_match_init(&match, &key, &mask);
> +       error = ovs_nla_get_match(&match,
> +                                 a[OVS_FLOW_ATTR_KEY], a[OVS_FLOW_ATTR_MASK]);
> +       if (error)
> +               goto error;
>
> -                       old_acts = ovsl_dereference(flow->sf_acts);
> -                       rcu_assign_pointer(flow->sf_acts, acts);
> -                       ovs_nla_free_flow_actions(old_acts);
> +       /* Validate actions. */
> +       if (a[OVS_FLOW_ATTR_ACTIONS]) {
> +               acts = ovs_nla_alloc_flow_actions(nla_len(a[OVS_FLOW_ATTR_ACTIONS]));
> +               error = PTR_ERR(acts);
> +               if (IS_ERR(acts))
> +                       goto error;
> +
> +               ovs_flow_mask_key(&masked_key, &key, &mask);
> +               error = ovs_nla_copy_actions(a[OVS_FLOW_ATTR_ACTIONS],
> +                                            &masked_key, 0, &acts);
> +               if (error) {
> +                       OVS_NLERR("Flow actions may not be safe on all matching packets.\n");
> +                       goto err_kfree;
>                 }
> +       }
>
> -               if (ovs_must_build_reply(info, &ovs_dp_flow_multicast_group))
> -                       reply = ovs_flow_cmd_build_info(flow,
> -                                                       ovs_header->dp_ifindex,
> -                                                       info,
> -                                                       OVS_FLOW_CMD_NEW);
> +       ovs_lock();
> +       dp = get_dp(sock_net(skb->sk), ovs_header->dp_ifindex);
> +       error = -ENODEV;
> +       if (!dp)
> +               goto err_unlock_ovs;
>
> -               /* Clear stats. */
> -               if (a[OVS_FLOW_ATTR_CLEAR])
> -                       ovs_flow_stats_clear(flow);
> +       /* Check if this is a duplicate flow */
> +       flow = ovs_flow_tbl_lookup(&dp->table, &key);
> +       error = -ENOENT;
> +       if (!flow)
> +               goto err_unlock_ovs;
> +
> +       /* The unmasked key has to be the same for flow updates. */
> +       if (!ovs_flow_cmp_unmasked_key(flow, &match))
> +               goto err_unlock_ovs;
> +
> +       /* Update actions, if present. */
> +       if (acts) {
> +               struct sw_flow_actions *old_acts;
> +
> +               old_acts = ovsl_dereference(flow->sf_acts);
> +               rcu_assign_pointer(flow->sf_acts, acts);
> +               ovs_nla_free_flow_actions(old_acts);
>         }
> +
> +       if (ovs_must_build_reply(info, &ovs_dp_flow_multicast_group))
> +               reply = ovs_flow_cmd_build_info(flow, ovs_header->dp_ifindex,
> +                                               info, OVS_FLOW_CMD_NEW);
> +       /* Clear stats. */
> +       if (a[OVS_FLOW_ATTR_CLEAR])
> +               ovs_flow_stats_clear(flow);
>         ovs_unlock();
>
>         if (reply) {
> @@ -912,8 +982,6 @@ static int ovs_flow_cmd_new_or_set(struct sk_buff *skb, struct genl_info *info)
>         }
>         return 0;
>
> -err_flow_free:
> -       ovs_flow_free(flow, false);
>  err_unlock_ovs:
>         ovs_unlock();
>  err_kfree:
> @@ -1066,7 +1134,7 @@ static struct genl_ops dp_flow_genl_ops[] = {
>         { .cmd = OVS_FLOW_CMD_NEW,
>           .flags = GENL_ADMIN_PERM, /* Requires CAP_NET_ADMIN privilege. */
>           .policy = flow_policy,
> -         .doit = ovs_flow_cmd_new_or_set
> +         .doit = ovs_flow_cmd_new
>         },
>         { .cmd = OVS_FLOW_CMD_DEL,
>           .flags = GENL_ADMIN_PERM, /* Requires CAP_NET_ADMIN privilege. */
> @@ -1082,7 +1150,7 @@ static struct genl_ops dp_flow_genl_ops[] = {
>         { .cmd = OVS_FLOW_CMD_SET,
>           .flags = GENL_ADMIN_PERM, /* Requires CAP_NET_ADMIN privilege. */
>           .policy = flow_policy,
> -         .doit = ovs_flow_cmd_new_or_set,
> +         .doit = ovs_flow_cmd_set,
>         },
>  };
>
otherwise looks good.
Acked-by: Pravin B Shelar <pshelar at nicira.com>

> --
> 1.7.10.4
>
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