linux/net/sched/act_simple.c
Pedro Tammela 871cf386dd net/sched: avoid indirect act functions on retpoline kernels
Expose the necessary tc act functions and wire up act_api to use
direct calls in retpoline kernels.

Signed-off-by: Pedro Tammela <pctammela@mojatatu.com>
Reviewed-by: Jamal Hadi Salim <jhs@mojatatu.com>
Reviewed-by: Victor Nogueira <victor@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-12-09 09:18:07 +00:00

251 lines
5.9 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* net/sched/act_simple.c Simple example of an action
*
* Authors: Jamal Hadi Salim (2005-8)
*/
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/skbuff.h>
#include <linux/rtnetlink.h>
#include <net/netlink.h>
#include <net/pkt_sched.h>
#include <net/pkt_cls.h>
#include <net/tc_wrapper.h>
#include <linux/tc_act/tc_defact.h>
#include <net/tc_act/tc_defact.h>
static struct tc_action_ops act_simp_ops;
#define SIMP_MAX_DATA 32
TC_INDIRECT_SCOPE int tcf_simp_act(struct sk_buff *skb,
const struct tc_action *a,
struct tcf_result *res)
{
struct tcf_defact *d = to_defact(a);
spin_lock(&d->tcf_lock);
tcf_lastuse_update(&d->tcf_tm);
bstats_update(&d->tcf_bstats, skb);
/* print policy string followed by _ then packet count
* Example if this was the 3rd packet and the string was "hello"
* then it would look like "hello_3" (without quotes)
*/
pr_info("simple: %s_%llu\n",
(char *)d->tcfd_defdata,
u64_stats_read(&d->tcf_bstats.packets));
spin_unlock(&d->tcf_lock);
return d->tcf_action;
}
static void tcf_simp_release(struct tc_action *a)
{
struct tcf_defact *d = to_defact(a);
kfree(d->tcfd_defdata);
}
static int alloc_defdata(struct tcf_defact *d, const struct nlattr *defdata)
{
d->tcfd_defdata = kzalloc(SIMP_MAX_DATA, GFP_KERNEL);
if (unlikely(!d->tcfd_defdata))
return -ENOMEM;
nla_strscpy(d->tcfd_defdata, defdata, SIMP_MAX_DATA);
return 0;
}
static int reset_policy(struct tc_action *a, const struct nlattr *defdata,
struct tc_defact *p, struct tcf_proto *tp,
struct netlink_ext_ack *extack)
{
struct tcf_chain *goto_ch = NULL;
struct tcf_defact *d;
int err;
err = tcf_action_check_ctrlact(p->action, tp, &goto_ch, extack);
if (err < 0)
return err;
d = to_defact(a);
spin_lock_bh(&d->tcf_lock);
goto_ch = tcf_action_set_ctrlact(a, p->action, goto_ch);
memset(d->tcfd_defdata, 0, SIMP_MAX_DATA);
nla_strscpy(d->tcfd_defdata, defdata, SIMP_MAX_DATA);
spin_unlock_bh(&d->tcf_lock);
if (goto_ch)
tcf_chain_put_by_act(goto_ch);
return 0;
}
static const struct nla_policy simple_policy[TCA_DEF_MAX + 1] = {
[TCA_DEF_PARMS] = { .len = sizeof(struct tc_defact) },
[TCA_DEF_DATA] = { .type = NLA_STRING, .len = SIMP_MAX_DATA },
};
static int tcf_simp_init(struct net *net, struct nlattr *nla,
struct nlattr *est, struct tc_action **a,
struct tcf_proto *tp, u32 flags,
struct netlink_ext_ack *extack)
{
struct tc_action_net *tn = net_generic(net, act_simp_ops.net_id);
bool bind = flags & TCA_ACT_FLAGS_BIND;
struct nlattr *tb[TCA_DEF_MAX + 1];
struct tcf_chain *goto_ch = NULL;
struct tc_defact *parm;
struct tcf_defact *d;
bool exists = false;
int ret = 0, err;
u32 index;
if (nla == NULL)
return -EINVAL;
err = nla_parse_nested_deprecated(tb, TCA_DEF_MAX, nla, simple_policy,
NULL);
if (err < 0)
return err;
if (tb[TCA_DEF_PARMS] == NULL)
return -EINVAL;
parm = nla_data(tb[TCA_DEF_PARMS]);
index = parm->index;
err = tcf_idr_check_alloc(tn, &index, a, bind);
if (err < 0)
return err;
exists = err;
if (exists && bind)
return 0;
if (tb[TCA_DEF_DATA] == NULL) {
if (exists)
tcf_idr_release(*a, bind);
else
tcf_idr_cleanup(tn, index);
return -EINVAL;
}
if (!exists) {
ret = tcf_idr_create(tn, index, est, a,
&act_simp_ops, bind, false, flags);
if (ret) {
tcf_idr_cleanup(tn, index);
return ret;
}
d = to_defact(*a);
err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch,
extack);
if (err < 0)
goto release_idr;
err = alloc_defdata(d, tb[TCA_DEF_DATA]);
if (err < 0)
goto put_chain;
tcf_action_set_ctrlact(*a, parm->action, goto_ch);
ret = ACT_P_CREATED;
} else {
if (!(flags & TCA_ACT_FLAGS_REPLACE)) {
err = -EEXIST;
goto release_idr;
}
err = reset_policy(*a, tb[TCA_DEF_DATA], parm, tp, extack);
if (err)
goto release_idr;
}
return ret;
put_chain:
if (goto_ch)
tcf_chain_put_by_act(goto_ch);
release_idr:
tcf_idr_release(*a, bind);
return err;
}
static int tcf_simp_dump(struct sk_buff *skb, struct tc_action *a,
int bind, int ref)
{
unsigned char *b = skb_tail_pointer(skb);
struct tcf_defact *d = to_defact(a);
struct tc_defact opt = {
.index = d->tcf_index,
.refcnt = refcount_read(&d->tcf_refcnt) - ref,
.bindcnt = atomic_read(&d->tcf_bindcnt) - bind,
};
struct tcf_t t;
spin_lock_bh(&d->tcf_lock);
opt.action = d->tcf_action;
if (nla_put(skb, TCA_DEF_PARMS, sizeof(opt), &opt) ||
nla_put_string(skb, TCA_DEF_DATA, d->tcfd_defdata))
goto nla_put_failure;
tcf_tm_dump(&t, &d->tcf_tm);
if (nla_put_64bit(skb, TCA_DEF_TM, sizeof(t), &t, TCA_DEF_PAD))
goto nla_put_failure;
spin_unlock_bh(&d->tcf_lock);
return skb->len;
nla_put_failure:
spin_unlock_bh(&d->tcf_lock);
nlmsg_trim(skb, b);
return -1;
}
static struct tc_action_ops act_simp_ops = {
.kind = "simple",
.id = TCA_ID_SIMP,
.owner = THIS_MODULE,
.act = tcf_simp_act,
.dump = tcf_simp_dump,
.cleanup = tcf_simp_release,
.init = tcf_simp_init,
.size = sizeof(struct tcf_defact),
};
static __net_init int simp_init_net(struct net *net)
{
struct tc_action_net *tn = net_generic(net, act_simp_ops.net_id);
return tc_action_net_init(net, tn, &act_simp_ops);
}
static void __net_exit simp_exit_net(struct list_head *net_list)
{
tc_action_net_exit(net_list, act_simp_ops.net_id);
}
static struct pernet_operations simp_net_ops = {
.init = simp_init_net,
.exit_batch = simp_exit_net,
.id = &act_simp_ops.net_id,
.size = sizeof(struct tc_action_net),
};
MODULE_AUTHOR("Jamal Hadi Salim(2005)");
MODULE_DESCRIPTION("Simple example action");
MODULE_LICENSE("GPL");
static int __init simp_init_module(void)
{
int ret = tcf_register_action(&act_simp_ops, &simp_net_ops);
if (!ret)
pr_info("Simple TC action Loaded\n");
return ret;
}
static void __exit simp_cleanup_module(void)
{
tcf_unregister_action(&act_simp_ops, &simp_net_ops);
}
module_init(simp_init_module);
module_exit(simp_cleanup_module);