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openvswitch: Add recirc and hash action.

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Recirc action allows a packet to reenter openvswitch processing.
currently openvswitch lookup flow for packet received and execute
set of actions on that packet, with help of recirc action we can
process/modify the packet and recirculate it back in openvswitch
for another pass.

OVS hash action calculates 5-tupple hash and set hash in flow-key
hash. This can be used along with recirculation for distributing
packets among different ports for bond devices.
For example:
OVS bonding can use following actions:
Match on: bond flow; Action: hash, recirc(id)
Match on: recirc-id == id and hash lower bits == a;
          Action: output port_bond_a

Signed-off-by: Andy Zhou <azhou@nicira.com>
Acked-by: Jesse Gross <jesse@nicira.com>
Signed-off-by: Pravin B Shelar <pshelar@nicira.com>
This commit is contained in:
Andy Zhou
2014-09-15 19:37:25 -07:00
committed by Pravin B Shelar
parent 32ae87ff79
commit 971427f353
7 changed files with 288 additions and 12 deletions
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203
net/openvswitch/actions.c
View File

@@ -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
@@ -35,12 +35,78 @@
#include <net/sctp/checksum.h>
#include "datapath.h"
#include "flow.h"
#include "vport.h"
static int do_execute_actions(struct datapath *dp, struct sk_buff *skb,
struct sw_flow_key *key,
const struct nlattr *attr, int len);
struct deferred_action {
struct sk_buff *skb;
const struct nlattr *actions;
/* Store pkt_key clone when creating deferred action. */
struct sw_flow_key pkt_key;
};
#define DEFERRED_ACTION_FIFO_SIZE 10
struct action_fifo {
int head;
int tail;
/* Deferred action fifo queue storage. */
struct deferred_action fifo[DEFERRED_ACTION_FIFO_SIZE];
};
static struct action_fifo __percpu *action_fifos;
static DEFINE_PER_CPU(int, exec_actions_level);
static void action_fifo_init(struct action_fifo *fifo)
{
fifo->head = 0;
fifo->tail = 0;
}
static bool action_fifo_is_empty(struct action_fifo *fifo)
{
return (fifo->head == fifo->tail);
}
static struct deferred_action *action_fifo_get(struct action_fifo *fifo)
{
if (action_fifo_is_empty(fifo))
return NULL;
return &fifo->fifo[fifo->tail++];
}
static struct deferred_action *action_fifo_put(struct action_fifo *fifo)
{
if (fifo->head >= DEFERRED_ACTION_FIFO_SIZE - 1)
return NULL;
return &fifo->fifo[fifo->head++];
}
/* Return true if fifo is not full */
static struct deferred_action *add_deferred_actions(struct sk_buff *skb,
struct sw_flow_key *key,
const struct nlattr *attr)
{
struct action_fifo *fifo;
struct deferred_action *da;
fifo = this_cpu_ptr(action_fifos);
da = action_fifo_put(fifo);
if (da) {
da->skb = skb;
da->actions = attr;
da->pkt_key = *key;
}
return da;
}
static int make_writable(struct sk_buff *skb, int write_len)
{
if (!pskb_may_pull(skb, write_len))
@@ -485,8 +551,29 @@ static int sample(struct datapath *dp, struct sk_buff *skb,
/* Skip the sample action when out of memory. */
return 0;
/* do_execute_actions() will consume the cloned skb. */
return do_execute_actions(dp, skb, key, a, rem);
if (!add_deferred_actions(skb, key, a)) {
if (net_ratelimit())
pr_warn("%s: deferred actions limit reached, dropping sample action\n",
ovs_dp_name(dp));
kfree_skb(skb);
}
return 0;
}
static void execute_hash(struct sk_buff *skb, struct sw_flow_key *key,
const struct nlattr *attr)
{
struct ovs_action_hash *hash_act = nla_data(attr);
u32 hash = 0;
/* OVS_HASH_ALG_L4 is the only possible hash algorithm. */
hash = skb_get_hash(skb);
hash = jhash_1word(hash, hash_act->hash_basis);
if (!hash)
hash = 0x1;
key->ovs_flow_hash = hash;
}
static int execute_set_action(struct sk_buff *skb,
@@ -535,6 +622,44 @@ static int execute_set_action(struct sk_buff *skb,
return err;
}
static int execute_recirc(struct datapath *dp, struct sk_buff *skb,
struct sw_flow_key *key,
const struct nlattr *a, int rem)
{
struct deferred_action *da;
int err;
err = ovs_flow_key_update(skb, key);
if (err)
return err;
if (!last_action(a, rem)) {
/* Recirc action is the not the last action
* of the action list, need to clone the skb.
*/
skb = skb_clone(skb, GFP_ATOMIC);
/* Skip the recirc action when out of memory, but
* continue on with the rest of the action list.
*/
if (!skb)
return 0;
}
da = add_deferred_actions(skb, key, NULL);
if (da) {
da->pkt_key.recirc_id = nla_get_u32(a);
} else {
kfree_skb(skb);
if (net_ratelimit())
pr_warn("%s: deferred action limit reached, drop recirc action\n",
ovs_dp_name(dp));
}
return 0;
}
/* Execute a list of actions against 'skb'. */
static int do_execute_actions(struct datapath *dp, struct sk_buff *skb,
struct sw_flow_key *key,
@@ -566,6 +691,10 @@ static int do_execute_actions(struct datapath *dp, struct sk_buff *skb,
output_userspace(dp, skb, key, a);
break;
case OVS_ACTION_ATTR_HASH:
execute_hash(skb, key, a);
break;
case OVS_ACTION_ATTR_PUSH_VLAN:
err = push_vlan(skb, nla_data(a));
if (unlikely(err)) /* skb already freed. */
@@ -576,6 +705,17 @@ static int do_execute_actions(struct datapath *dp, struct sk_buff *skb,
err = pop_vlan(skb);
break;
case OVS_ACTION_ATTR_RECIRC:
err = execute_recirc(dp, skb, key, a, rem);
if (last_action(a, rem)) {
/* If this is the last action, the skb has
* been consumed or freed.
* Return immediately.
*/
return err;
}
break;
case OVS_ACTION_ATTR_SET:
err = execute_set_action(skb, nla_data(a));
break;
@@ -601,12 +741,63 @@ static int do_execute_actions(struct datapath *dp, struct sk_buff *skb,
return 0;
}
static void process_deferred_actions(struct datapath *dp)
{
struct action_fifo *fifo = this_cpu_ptr(action_fifos);
/* Do not touch the FIFO in case there is no deferred actions. */
if (action_fifo_is_empty(fifo))
return;
/* Finishing executing all deferred actions. */
do {
struct deferred_action *da = action_fifo_get(fifo);
struct sk_buff *skb = da->skb;
struct sw_flow_key *key = &da->pkt_key;
const struct nlattr *actions = da->actions;
if (actions)
do_execute_actions(dp, skb, key, actions,
nla_len(actions));
else
ovs_dp_process_packet(skb, key);
} while (!action_fifo_is_empty(fifo));
/* Reset FIFO for the next packet. */
action_fifo_init(fifo);
}
/* Execute a list of actions against 'skb'. */
int ovs_execute_actions(struct datapath *dp, struct sk_buff *skb,
struct sw_flow_key *key)
{
struct sw_flow_actions *acts = rcu_dereference(OVS_CB(skb)->flow->sf_acts);
int level = this_cpu_read(exec_actions_level);
struct sw_flow_actions *acts;
int err;
return do_execute_actions(dp, skb, key,
acts->actions, acts->actions_len);
acts = rcu_dereference(OVS_CB(skb)->flow->sf_acts);
this_cpu_inc(exec_actions_level);
err = do_execute_actions(dp, skb, key,
acts->actions, acts->actions_len);
if (!level)
process_deferred_actions(dp);
this_cpu_dec(exec_actions_level);
return err;
}
int action_fifos_init(void)
{
action_fifos = alloc_percpu(struct action_fifo);
if (!action_fifos)
return -ENOMEM;
return 0;
}
void action_fifos_exit(void)
{
free_percpu(action_fifos);
}