linux/net/sched/act_vlan.c
Manish Kurup 4c5b9d9642 act_vlan: VLAN action rewrite to use RCU lock/unlock and update
Using a spinlock in the VLAN action causes performance issues when the VLAN
action is used on multiple cores. Rewrote the VLAN action to use RCU read
locking for reads and updates instead.
All functions now use an RCU dereferenced pointer to access the VLAN action
context. Modified helper functions used by other modules, to use the RCU as
opposed to directly accessing the structure.

Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Manish Kurup <manish.kurup@verizon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-10 15:32:20 +09:00

334 lines
7.7 KiB
C

/*
* Copyright (c) 2014 Jiri Pirko <jiri@resnulli.us>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/skbuff.h>
#include <linux/rtnetlink.h>
#include <linux/if_vlan.h>
#include <net/netlink.h>
#include <net/pkt_sched.h>
#include <linux/tc_act/tc_vlan.h>
#include <net/tc_act/tc_vlan.h>
static unsigned int vlan_net_id;
static struct tc_action_ops act_vlan_ops;
static int tcf_vlan(struct sk_buff *skb, const struct tc_action *a,
struct tcf_result *res)
{
struct tcf_vlan *v = to_vlan(a);
struct tcf_vlan_params *p;
int action;
int err;
u16 tci;
tcf_lastuse_update(&v->tcf_tm);
bstats_cpu_update(this_cpu_ptr(v->common.cpu_bstats), skb);
/* Ensure 'data' points at mac_header prior calling vlan manipulating
* functions.
*/
if (skb_at_tc_ingress(skb))
skb_push_rcsum(skb, skb->mac_len);
rcu_read_lock();
action = READ_ONCE(v->tcf_action);
p = rcu_dereference(v->vlan_p);
switch (p->tcfv_action) {
case TCA_VLAN_ACT_POP:
err = skb_vlan_pop(skb);
if (err)
goto drop;
break;
case TCA_VLAN_ACT_PUSH:
err = skb_vlan_push(skb, p->tcfv_push_proto, p->tcfv_push_vid |
(p->tcfv_push_prio << VLAN_PRIO_SHIFT));
if (err)
goto drop;
break;
case TCA_VLAN_ACT_MODIFY:
/* No-op if no vlan tag (either hw-accel or in-payload) */
if (!skb_vlan_tagged(skb))
goto unlock;
/* extract existing tag (and guarantee no hw-accel tag) */
if (skb_vlan_tag_present(skb)) {
tci = skb_vlan_tag_get(skb);
skb->vlan_tci = 0;
} else {
/* in-payload vlan tag, pop it */
err = __skb_vlan_pop(skb, &tci);
if (err)
goto drop;
}
/* replace the vid */
tci = (tci & ~VLAN_VID_MASK) | p->tcfv_push_vid;
/* replace prio bits, if tcfv_push_prio specified */
if (p->tcfv_push_prio) {
tci &= ~VLAN_PRIO_MASK;
tci |= p->tcfv_push_prio << VLAN_PRIO_SHIFT;
}
/* put updated tci as hwaccel tag */
__vlan_hwaccel_put_tag(skb, p->tcfv_push_proto, tci);
break;
default:
BUG();
}
goto unlock;
drop:
action = TC_ACT_SHOT;
qstats_drop_inc(this_cpu_ptr(v->common.cpu_qstats));
unlock:
rcu_read_unlock();
if (skb_at_tc_ingress(skb))
skb_pull_rcsum(skb, skb->mac_len);
return action;
}
static const struct nla_policy vlan_policy[TCA_VLAN_MAX + 1] = {
[TCA_VLAN_PARMS] = { .len = sizeof(struct tc_vlan) },
[TCA_VLAN_PUSH_VLAN_ID] = { .type = NLA_U16 },
[TCA_VLAN_PUSH_VLAN_PROTOCOL] = { .type = NLA_U16 },
[TCA_VLAN_PUSH_VLAN_PRIORITY] = { .type = NLA_U8 },
};
static int tcf_vlan_init(struct net *net, struct nlattr *nla,
struct nlattr *est, struct tc_action **a,
int ovr, int bind)
{
struct tc_action_net *tn = net_generic(net, vlan_net_id);
struct nlattr *tb[TCA_VLAN_MAX + 1];
struct tcf_vlan_params *p, *p_old;
struct tc_vlan *parm;
struct tcf_vlan *v;
int action;
__be16 push_vid = 0;
__be16 push_proto = 0;
u8 push_prio = 0;
bool exists = false;
int ret = 0, err;
if (!nla)
return -EINVAL;
err = nla_parse_nested(tb, TCA_VLAN_MAX, nla, vlan_policy, NULL);
if (err < 0)
return err;
if (!tb[TCA_VLAN_PARMS])
return -EINVAL;
parm = nla_data(tb[TCA_VLAN_PARMS]);
exists = tcf_idr_check(tn, parm->index, a, bind);
if (exists && bind)
return 0;
switch (parm->v_action) {
case TCA_VLAN_ACT_POP:
break;
case TCA_VLAN_ACT_PUSH:
case TCA_VLAN_ACT_MODIFY:
if (!tb[TCA_VLAN_PUSH_VLAN_ID]) {
if (exists)
tcf_idr_release(*a, bind);
return -EINVAL;
}
push_vid = nla_get_u16(tb[TCA_VLAN_PUSH_VLAN_ID]);
if (push_vid >= VLAN_VID_MASK) {
if (exists)
tcf_idr_release(*a, bind);
return -ERANGE;
}
if (tb[TCA_VLAN_PUSH_VLAN_PROTOCOL]) {
push_proto = nla_get_be16(tb[TCA_VLAN_PUSH_VLAN_PROTOCOL]);
switch (push_proto) {
case htons(ETH_P_8021Q):
case htons(ETH_P_8021AD):
break;
default:
return -EPROTONOSUPPORT;
}
} else {
push_proto = htons(ETH_P_8021Q);
}
if (tb[TCA_VLAN_PUSH_VLAN_PRIORITY])
push_prio = nla_get_u8(tb[TCA_VLAN_PUSH_VLAN_PRIORITY]);
break;
default:
if (exists)
tcf_idr_release(*a, bind);
return -EINVAL;
}
action = parm->v_action;
if (!exists) {
ret = tcf_idr_create(tn, parm->index, est, a,
&act_vlan_ops, bind, true);
if (ret)
return ret;
ret = ACT_P_CREATED;
} else {
tcf_idr_release(*a, bind);
if (!ovr)
return -EEXIST;
}
v = to_vlan(*a);
ASSERT_RTNL();
p = kzalloc(sizeof(*p), GFP_KERNEL);
if (!p) {
if (ovr)
tcf_idr_release(*a, bind);
return -ENOMEM;
}
v->tcf_action = parm->action;
p_old = rtnl_dereference(v->vlan_p);
p->tcfv_action = action;
p->tcfv_push_vid = push_vid;
p->tcfv_push_prio = push_prio;
p->tcfv_push_proto = push_proto;
rcu_assign_pointer(v->vlan_p, p);
if (p_old)
kfree_rcu(p_old, rcu);
if (ret == ACT_P_CREATED)
tcf_idr_insert(tn, *a);
return ret;
}
static void tcf_vlan_cleanup(struct tc_action *a, int bind)
{
struct tcf_vlan *v = to_vlan(a);
struct tcf_vlan_params *p;
p = rcu_dereference_protected(v->vlan_p, 1);
kfree_rcu(p, rcu);
}
static int tcf_vlan_dump(struct sk_buff *skb, struct tc_action *a,
int bind, int ref)
{
unsigned char *b = skb_tail_pointer(skb);
struct tcf_vlan *v = to_vlan(a);
struct tcf_vlan_params *p = rtnl_dereference(v->vlan_p);
struct tc_vlan opt = {
.index = v->tcf_index,
.refcnt = v->tcf_refcnt - ref,
.bindcnt = v->tcf_bindcnt - bind,
.action = v->tcf_action,
.v_action = p->tcfv_action,
};
struct tcf_t t;
if (nla_put(skb, TCA_VLAN_PARMS, sizeof(opt), &opt))
goto nla_put_failure;
if ((p->tcfv_action == TCA_VLAN_ACT_PUSH ||
p->tcfv_action == TCA_VLAN_ACT_MODIFY) &&
(nla_put_u16(skb, TCA_VLAN_PUSH_VLAN_ID, p->tcfv_push_vid) ||
nla_put_be16(skb, TCA_VLAN_PUSH_VLAN_PROTOCOL,
p->tcfv_push_proto) ||
(nla_put_u8(skb, TCA_VLAN_PUSH_VLAN_PRIORITY,
p->tcfv_push_prio))))
goto nla_put_failure;
tcf_tm_dump(&t, &v->tcf_tm);
if (nla_put_64bit(skb, TCA_VLAN_TM, sizeof(t), &t, TCA_VLAN_PAD))
goto nla_put_failure;
return skb->len;
nla_put_failure:
nlmsg_trim(skb, b);
return -1;
}
static int tcf_vlan_walker(struct net *net, struct sk_buff *skb,
struct netlink_callback *cb, int type,
const struct tc_action_ops *ops)
{
struct tc_action_net *tn = net_generic(net, vlan_net_id);
return tcf_generic_walker(tn, skb, cb, type, ops);
}
static int tcf_vlan_search(struct net *net, struct tc_action **a, u32 index)
{
struct tc_action_net *tn = net_generic(net, vlan_net_id);
return tcf_idr_search(tn, a, index);
}
static struct tc_action_ops act_vlan_ops = {
.kind = "vlan",
.type = TCA_ACT_VLAN,
.owner = THIS_MODULE,
.act = tcf_vlan,
.dump = tcf_vlan_dump,
.init = tcf_vlan_init,
.cleanup = tcf_vlan_cleanup,
.walk = tcf_vlan_walker,
.lookup = tcf_vlan_search,
.size = sizeof(struct tcf_vlan),
};
static __net_init int vlan_init_net(struct net *net)
{
struct tc_action_net *tn = net_generic(net, vlan_net_id);
return tc_action_net_init(tn, &act_vlan_ops);
}
static void __net_exit vlan_exit_net(struct net *net)
{
struct tc_action_net *tn = net_generic(net, vlan_net_id);
tc_action_net_exit(tn);
}
static struct pernet_operations vlan_net_ops = {
.init = vlan_init_net,
.exit = vlan_exit_net,
.id = &vlan_net_id,
.size = sizeof(struct tc_action_net),
};
static int __init vlan_init_module(void)
{
return tcf_register_action(&act_vlan_ops, &vlan_net_ops);
}
static void __exit vlan_cleanup_module(void)
{
tcf_unregister_action(&act_vlan_ops, &vlan_net_ops);
}
module_init(vlan_init_module);
module_exit(vlan_cleanup_module);
MODULE_AUTHOR("Jiri Pirko <jiri@resnulli.us>");
MODULE_DESCRIPTION("vlan manipulation actions");
MODULE_LICENSE("GPL v2");