On Sat, Apr 12, 2014 at 3:30 AM, Andy Zhou <[email protected]> wrote:
> Implements Linux kernel datapath recirc action. Recirc action allows
> kernel data patch reprocess the packet as if it is received from its
> original input port, with a recirc_id added to its flow key.
>
> The recirc action follows a sub routine call model. The packet change
> by actions during recirculation is invisible across a recirculation;
> any action following the recirc action will process the same packet
> prior to the recirc action.
>
> Signed-off-by: Andy Zhou <[email protected]>
> ---
> datapath/actions.c | 54
> ++++++++++++++++++++++++++++++++++++++++++++++-
> datapath/datapath.c | 37 +++++++++++++++++++-------------
> datapath/datapath.h | 3 ++-
> datapath/flow_netlink.c | 31 ++++++++++++++++++++++++++-
> 4 files changed, 107 insertions(+), 18 deletions(-)
>
> diff --git a/datapath/actions.c b/datapath/actions.c
> index cb239c8..c833c69 100644
> --- a/datapath/actions.c
> +++ b/datapath/actions.c
> @@ -1,5 +1,5 @@
> /*
> - * Copyright (c) 2007-2013 Nicira, Inc.
> + * Copyright (c) 2007-2014 Nicira, Inc.
> *
> * This program is free software; you can redistribute it and/or
> * modify it under the terms of version 2 of the GNU General Public
> @@ -521,6 +521,34 @@ static int execute_set_action(struct sk_buff *skb,
> return err;
> }
>
> +static int execute_recirc(struct datapath *dp, struct sk_buff *skb,
> + const struct nlattr *recirc_attr,
> + uint16_t in_port, uint32_t dp_hash)
> +{
> + struct sw_flow_key recirc_key;
> + struct vport *p;
> + int err;
> +
> + err = ovs_flow_extract(skb, in_port, &recirc_key);
> + if (err)
> + return err;
> +
> + recirc_key.dp_hash = dp_hash;
> + recirc_key.recirc_id = nla_get_u32(recirc_attr);
> + OVS_CB(skb)->pkt_key = &recirc_key;
> + OVS_CB(skb)->flow = NULL;
> +
Do we need to reset flow here?
> + p = ovs_vport_rcu(dp, in_port);
> + if (unlikely(!p)) {
> + kfree_skb(skb);
> + return -ENODEV;
> + }
> +
> + ovs_dp_process_packet_with_key(p, skb);
> +
Can we avoid flow-extract and vport lookup. it does add per packet
processing cost.
> + return 0;
> +}
> +
> /* Execute a list of actions against 'skb'. */
> static int do_execute_actions(struct datapath *dp, struct sk_buff *skb,
> const struct nlattr *attr, int len, bool keep_skb)
> @@ -565,12 +593,36 @@ static int do_execute_actions(struct datapath *dp,
> struct sk_buff *skb,
> err = pop_vlan(skb);
> break;
>
> + case OVS_ACTION_ATTR_RECIRC: {
> + struct sk_buff *recirc_skb;
> + const bool last_action = (a->nla_len == rem);
> + uint16_t in_port = OVS_CB(skb)->pkt_key->phy.in_port;
> + uint32_t dp_hash = OVS_CB(skb)->pkt_key->dp_hash;
> +
> + if (!last_action || keep_skb)
> + recirc_skb = skb_clone(skb, GFP_ATOMIC);
> + else
> + recirc_skb = skb;
> +
> + err = execute_recirc(dp, recirc_skb, a, in_port,
> + dp_hash);
> +
Why are hash and in-port are explicitly passed to execute_recirc()?
> + /* Return directly if recirc is the last action
> + * or err. */
> + if (last_action || err)
> + return err;
> +
> + break;
> + }
> +
> case OVS_ACTION_ATTR_SET:
> err = execute_set_action(skb, nla_data(a));
> break;
>
> case OVS_ACTION_ATTR_SAMPLE:
> err = sample(dp, skb, a);
> + if (unlikely(err)) /* skb already freed. */
> + return err;
> break;
good catch.
This is bug fix and need to be back-ported. Can you send separate patch?
> }
>
> diff --git a/datapath/datapath.c b/datapath/datapath.c
> index 25edd7d..dab4a6b 100644
> --- a/datapath/datapath.c
> +++ b/datapath/datapath.c
> @@ -240,33 +240,24 @@ void ovs_dp_detach_port(struct vport *p)
> ovs_vport_del(p);
> }
>
> -/* Must be called with rcu_read_lock. */
> -void ovs_dp_process_received_packet(struct vport *p, struct sk_buff *skb)
> +void ovs_dp_process_packet_with_key(const struct vport *p, struct sk_buff
> *skb)
> {
> struct datapath *dp = p->dp;
> struct sw_flow *flow;
> struct dp_stats_percpu *stats;
> - struct sw_flow_key key;
> + struct sw_flow_key *key = OVS_CB(skb)->pkt_key;
> u64 *stats_counter;
> u32 n_mask_hit;
> - int error;
>
> stats = this_cpu_ptr(dp->stats_percpu);
>
> - /* Extract flow from 'skb' into 'key'. */
> - error = ovs_flow_extract(skb, p->port_no, &key);
> - if (unlikely(error)) {
> - kfree_skb(skb);
> - return;
> - }
> -
> /* Look up flow. */
> - flow = ovs_flow_tbl_lookup_stats(&dp->table, &key, &n_mask_hit);
> + flow = ovs_flow_tbl_lookup_stats(&dp->table, key, &n_mask_hit);
> if (unlikely(!flow)) {
> struct dp_upcall_info upcall;
>
> upcall.cmd = OVS_PACKET_CMD_MISS;
> - upcall.key = &key;
> + upcall.key = key;
> upcall.userdata = NULL;
> upcall.portid = p->upcall_portid;
> ovs_dp_upcall(dp, skb, &upcall);
> @@ -276,9 +267,8 @@ void ovs_dp_process_received_packet(struct vport *p,
> struct sk_buff *skb)
> }
>
> OVS_CB(skb)->flow = flow;
> - OVS_CB(skb)->pkt_key = &key;
>
> - ovs_flow_stats_update(OVS_CB(skb)->flow, key.tp.flags, skb);
> + ovs_flow_stats_update(OVS_CB(skb)->flow, key->tp.flags, skb);
> ovs_execute_actions(dp, skb);
> stats_counter = &stats->n_hit;
>
> @@ -290,6 +280,23 @@ out:
> u64_stats_update_end(&stats->sync);
> }
>
> +/* Must be called with rcu_read_lock. */
> +void ovs_dp_process_received_packet(struct vport *p, struct sk_buff *skb)
> +{
> + int error;
> + struct sw_flow_key key;
> +
> + /* Extract flow from 'skb' into 'key'. */
> + error = ovs_flow_extract(skb, p->port_no, &key);
> + if (unlikely(error)) {
> + kfree_skb(skb);
> + return;
> + }
> +
> + OVS_CB(skb)->pkt_key = &key;
> + ovs_dp_process_packet_with_key(p, skb);
> +}
Can you pass key ovs_dp_process_packet_with_key(), so that we can only
one function can set OVS_CB flow and key.
> +
> int ovs_dp_upcall(struct datapath *dp, struct sk_buff *skb,
> const struct dp_upcall_info *upcall_info)
> {
> diff --git a/datapath/datapath.h b/datapath/datapath.h
> index 40e0f90..d3b06ee 100644
> --- a/datapath/datapath.h
> +++ b/datapath/datapath.h
> @@ -1,5 +1,5 @@
> /*
> - * Copyright (c) 2007-2012 Nicira, Inc.
> + * Copyright (c) 2007-2014 Nicira, Inc.
> *
> * This program is free software; you can redistribute it and/or
> * modify it under the terms of version 2 of the GNU General Public
> @@ -188,6 +188,7 @@ extern struct genl_family dp_vport_genl_family;
> extern struct genl_multicast_group ovs_dp_vport_multicast_group;
>
> void ovs_dp_process_received_packet(struct vport *, struct sk_buff *);
> +void ovs_dp_process_packet_with_key(const struct vport *, struct sk_buff *);
> void ovs_dp_detach_port(struct vport *);
> int ovs_dp_upcall(struct datapath *, struct sk_buff *,
> const struct dp_upcall_info *);
> diff --git a/datapath/flow_netlink.c b/datapath/flow_netlink.c
> index e85326b..f5249ee 100644
> --- a/datapath/flow_netlink.c
> +++ b/datapath/flow_netlink.c
> @@ -129,7 +129,8 @@ static bool match_validate(const struct sw_flow_match
> *match,
> /* Always allowed mask fields. */
> mask_allowed |= ((1ULL << OVS_KEY_ATTR_TUNNEL)
> | (1ULL << OVS_KEY_ATTR_IN_PORT)
> - | (1ULL << OVS_KEY_ATTR_ETHERTYPE));
> + | (1ULL << OVS_KEY_ATTR_ETHERTYPE)
> + | (1ULL << OVS_KEY_ATTR_RECIRC_ID));
>
> /* Check key attributes. */
> if (match->key->dp_hash) {
> @@ -258,6 +259,7 @@ static const int ovs_key_lens[OVS_KEY_ATTR_MAX + 1] = {
> [OVS_KEY_ATTR_ARP] = sizeof(struct ovs_key_arp),
> [OVS_KEY_ATTR_ND] = sizeof(struct ovs_key_nd),
> [OVS_KEY_ATTR_DP_HASH] = sizeof(u32),
> + [OVS_KEY_ATTR_RECIRC_ID] = sizeof(u32),
> [OVS_KEY_ATTR_TUNNEL] = -1,
> };
>
> @@ -474,6 +476,23 @@ static int metadata_from_nlattrs(struct sw_flow_match
> *match, u64 *attrs,
> *attrs &= ~(1ULL << OVS_KEY_ATTR_DP_HASH);
> }
>
> + if (*attrs & (1ULL << OVS_KEY_ATTR_RECIRC_ID)) {
> + u32 recirc_id = nla_get_u32(a[OVS_KEY_ATTR_RECIRC_ID]);
> +
> + if (is_mask && (recirc_id > 0 && recirc_id < UINT_MAX)) {
> + OVS_NLERR("Reicrc_id mask is neither wildcard nor
> exact match\n");
> + return -EINVAL;
> + }
> +
> + SW_FLOW_KEY_PUT(match, recirc_id, recirc_id, is_mask);
> + *attrs &= ~(1ULL << OVS_KEY_ATTR_RECIRC_ID);
> + }
> +
> + if (is_mask) {
> + /* Always exact match recirc_id. */
> + SW_FLOW_KEY_PUT(match, recirc_id, UINT_MAX, is_mask);
> + }
I am not sure why is this done unconditionally? This does increases
range for flow match.
> +
> if (*attrs & (1ULL << OVS_KEY_ATTR_PRIORITY)) {
> SW_FLOW_KEY_PUT(match, phy.priority,
> nla_get_u32(a[OVS_KEY_ATTR_PRIORITY]), is_mask);
> @@ -879,6 +898,7 @@ int ovs_nla_get_flow_metadata(struct sw_flow *flow,
> flow->key.phy.priority = 0;
> flow->key.phy.skb_mark = 0;
> flow->key.dp_hash = 0;
> + flow->key.recirc_id = 0;
Comment need a update.
> memset(tun_key, 0, sizeof(flow->key.tun_key));
>
> err = parse_flow_nlattrs(attr, a, &attrs);
> @@ -902,10 +922,15 @@ int ovs_nla_put_flow(const struct sw_flow_key *swkey,
> struct nlattr *nla, *encap;
> bool is_mask = (swkey != output);
>
> + /* dp_hash and recric_id are only valid if they are nonzero. */
> if (swkey->dp_hash)
> if (nla_put_u32(skb, OVS_KEY_ATTR_DP_HASH, output->dp_hash))
> goto nla_put_failure;
>
> + if (swkey->recirc_id)
> + if (nla_put_u32(skb, OVS_KEY_ATTR_RECIRC_ID,
> output->recirc_id))
> + goto nla_put_failure;
> +
Can you use && rather than nested if statement?
> if (nla_put_u32(skb, OVS_KEY_ATTR_PRIORITY, output->phy.priority))
> goto nla_put_failure;
>
> @@ -1442,6 +1467,7 @@ int ovs_nla_copy_actions(const struct nlattr *attr,
> /* Expected argument lengths, (u32)-1 for variable length. */
> static const u32 action_lens[OVS_ACTION_ATTR_MAX + 1] = {
> [OVS_ACTION_ATTR_OUTPUT] = sizeof(u32),
> + [OVS_ACTION_ATTR_RECIRC] = sizeof(u32),
> [OVS_ACTION_ATTR_USERSPACE] = (u32)-1,
> [OVS_ACTION_ATTR_PUSH_VLAN] = sizeof(struct
> ovs_action_push_vlan),
> [OVS_ACTION_ATTR_POP_VLAN] = 0,
> @@ -1488,6 +1514,9 @@ int ovs_nla_copy_actions(const struct nlattr *attr,
> return -EINVAL;
> break;
>
> + case OVS_ACTION_ATTR_RECIRC:
> + break;
> +
> case OVS_ACTION_ATTR_SET:
> err = validate_set(a, key, sfa, &skip_copy);
> if (err)
> --
> 1.7.9.5
>
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