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Commit 971427f3 authored by Andy Zhou's avatar Andy Zhou Committed by Pravin B Shelar
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openvswitch: Add recirc and hash action. 



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: default avatarAndy Zhou <azhou@nicira.com>
Acked-by: default avatarJesse Gross <jesse@nicira.com>
Signed-off-by: default avatarPravin B Shelar <pshelar@nicira.com>
parent 32ae87ff

include/uapi/linux/openvswitch.h

+26 −0
Original line number Diff line number Diff line
@@ -289,6 +289,9 @@ enum ovs_key_attr { 
	OVS_KEY_ATTR_TUNNEL,    /* Nested set of ovs_tunnel attributes */

	OVS_KEY_ATTR_SCTP,      /* struct ovs_key_sctp */

	OVS_KEY_ATTR_TCP_FLAGS,	/* be16 TCP flags. */

	OVS_KEY_ATTR_DP_HASH,      /* u32 hash value. Value 0 indicates the hash

				   is not computed by the datapath. */

	OVS_KEY_ATTR_RECIRC_ID, /* u32 recirc id */



#ifdef __KERNEL__

	OVS_KEY_ATTR_IPV4_TUNNEL,  /* struct ovs_key_ipv4_tunnel */
@@ -493,6 +496,27 @@ struct ovs_action_push_vlan { 
	__be16 vlan_tci;	/* 802.1Q TCI (VLAN ID and priority). */

};



/* Data path hash algorithm for computing Datapath hash.

 *

 * The algorithm type only specifies the fields in a flow

 * will be used as part of the hash. Each datapath is free

 * to use its own hash algorithm. The hash value will be

 * opaque to the user space daemon.

 */

enum ovs_hash_alg {

	OVS_HASH_ALG_L4,

};



/*

 * struct ovs_action_hash - %OVS_ACTION_ATTR_HASH action argument.

 * @hash_alg: Algorithm used to compute hash prior to recirculation.

 * @hash_basis: basis used for computing hash.

 */

struct ovs_action_hash {

	uint32_t  hash_alg;     /* One of ovs_hash_alg. */

	uint32_t  hash_basis;

};



/**

 * enum ovs_action_attr - Action types.

 *
@@ -521,6 +545,8 @@ enum ovs_action_attr { 
	OVS_ACTION_ATTR_PUSH_VLAN,    /* struct ovs_action_push_vlan. */

	OVS_ACTION_ATTR_POP_VLAN,     /* No argument. */

	OVS_ACTION_ATTR_SAMPLE,       /* Nested OVS_SAMPLE_ATTR_*. */

	OVS_ACTION_ATTR_RECIRC,       /* u32 recirc_id. */

	OVS_ACTION_ATTR_HASH,	      /* struct ovs_action_hash. */

	__OVS_ACTION_ATTR_MAX

};

net/openvswitch/actions.c

+197 −6
Original line number Diff line number Diff line 
/*

 * 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;



	acts = rcu_dereference(OVS_CB(skb)->flow->sf_acts);



	return do_execute_actions(dp, skb, key,

	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);

}

net/openvswitch/datapath.c

+9 −2
Original line number Diff line number Diff line
@@ -156,7 +156,7 @@ static struct datapath *get_dp(struct net *net, int dp_ifindex) 
}



/* Must be called with rcu_read_lock or ovs_mutex. */

static const char *ovs_dp_name(const struct datapath *dp)

const char *ovs_dp_name(const struct datapath *dp)

{

	struct vport *vport = ovs_vport_ovsl_rcu(dp, OVSP_LOCAL);

	return vport->ops->get_name(vport);
@@ -2065,10 +2065,14 @@ static int __init dp_init(void) 


	pr_info("Open vSwitch switching datapath\n");



	err = ovs_internal_dev_rtnl_link_register();

	err = action_fifos_init();

	if (err)

		goto error;



	err = ovs_internal_dev_rtnl_link_register();

	if (err)

		goto error_action_fifos_exit;



	err = ovs_flow_init();

	if (err)

		goto error_unreg_rtnl_link;
@@ -2101,6 +2105,8 @@ static int __init dp_init(void) 
	ovs_flow_exit();

error_unreg_rtnl_link:

	ovs_internal_dev_rtnl_link_unregister();

error_action_fifos_exit:

	action_fifos_exit();

error:

	return err;

}
@@ -2114,6 +2120,7 @@ static void dp_cleanup(void) 
	ovs_vport_exit();

	ovs_flow_exit();

	ovs_internal_dev_rtnl_link_unregister();

	action_fifos_exit();

}



module_init(dp_init);

net/openvswitch/datapath.h

+6 −1
Original line number Diff line number Diff line 
/*

 * 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
@@ -189,13 +189,18 @@ void ovs_dp_detach_port(struct vport *); 
int ovs_dp_upcall(struct datapath *, struct sk_buff *,

		  const struct dp_upcall_info *);



const char *ovs_dp_name(const struct datapath *dp);

struct sk_buff *ovs_vport_cmd_build_info(struct vport *, u32 pid, u32 seq,

					 u8 cmd);



int ovs_execute_actions(struct datapath *dp, struct sk_buff *skb,

			struct sw_flow_key *);



void ovs_dp_notify_wq(struct work_struct *work);



int action_fifos_init(void);

void action_fifos_exit(void);



#define OVS_NLERR(fmt, ...)					\

do {								\

	if (net_ratelimit())					\

net/openvswitch/flow.c

+6 −1
Original line number Diff line number Diff line 
/*

 * 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
@@ -606,6 +606,11 @@ static int key_extract(struct sk_buff *skb, struct sw_flow_key *key) 
	return 0;

}



int ovs_flow_key_update(struct sk_buff *skb, struct sw_flow_key *key)

{

	return key_extract(skb, key);

}



int ovs_flow_key_extract(struct ovs_key_ipv4_tunnel *tun_key,

			 struct sk_buff *skb, struct sw_flow_key *key)

{