linux/net/sched/cls_basic.c
Cong Wang 695176bfe5 net_sched: refactor TC action init API
TC action ->init() API has 10 parameters, it becomes harder
to read. Some of them are just boolean and can be replaced
by flags. Similarly for the internal API tcf_action_init()
and tcf_exts_validate().

This patch converts them to flags and fold them into
the upper 16 bits of "flags", whose lower 16 bits are still
reserved for user-space. More specifically, the following
kernel flags are introduced:

TCA_ACT_FLAGS_POLICE replace 'name' in a few contexts, to
distinguish whether it is compatible with policer.

TCA_ACT_FLAGS_BIND replaces 'bind', to indicate whether
this action is bound to a filter.

TCA_ACT_FLAGS_REPLACE  replaces 'ovr' in most contexts,
means we are replacing an existing action.

TCA_ACT_FLAGS_NO_RTNL replaces 'rtnl_held' but has the
opposite meaning, because we still hold RTNL in most
cases.

The only user-space flag TCA_ACT_FLAGS_NO_PERCPU_STATS is
untouched and still stored as before.

I have tested this patch with tdc and I do not see any
failure related to this patch.

Tested-by: Vlad Buslov <vladbu@nvidia.com>
Acked-by: Jamal Hadi Salim<jhs@mojatatu.com>
Cc: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: Cong Wang <cong.wang@bytedance.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-02 10:24:38 +01:00

355 lines
7.9 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* net/sched/cls_basic.c Basic Packet Classifier.
*
* Authors: Thomas Graf <tgraf@suug.ch>
*/
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/rtnetlink.h>
#include <linux/skbuff.h>
#include <linux/idr.h>
#include <linux/percpu.h>
#include <net/netlink.h>
#include <net/act_api.h>
#include <net/pkt_cls.h>
struct basic_head {
struct list_head flist;
struct idr handle_idr;
struct rcu_head rcu;
};
struct basic_filter {
u32 handle;
struct tcf_exts exts;
struct tcf_ematch_tree ematches;
struct tcf_result res;
struct tcf_proto *tp;
struct list_head link;
struct tc_basic_pcnt __percpu *pf;
struct rcu_work rwork;
};
static int basic_classify(struct sk_buff *skb, const struct tcf_proto *tp,
struct tcf_result *res)
{
int r;
struct basic_head *head = rcu_dereference_bh(tp->root);
struct basic_filter *f;
list_for_each_entry_rcu(f, &head->flist, link) {
__this_cpu_inc(f->pf->rcnt);
if (!tcf_em_tree_match(skb, &f->ematches, NULL))
continue;
__this_cpu_inc(f->pf->rhit);
*res = f->res;
r = tcf_exts_exec(skb, &f->exts, res);
if (r < 0)
continue;
return r;
}
return -1;
}
static void *basic_get(struct tcf_proto *tp, u32 handle)
{
struct basic_head *head = rtnl_dereference(tp->root);
struct basic_filter *f;
list_for_each_entry(f, &head->flist, link) {
if (f->handle == handle) {
return f;
}
}
return NULL;
}
static int basic_init(struct tcf_proto *tp)
{
struct basic_head *head;
head = kzalloc(sizeof(*head), GFP_KERNEL);
if (head == NULL)
return -ENOBUFS;
INIT_LIST_HEAD(&head->flist);
idr_init(&head->handle_idr);
rcu_assign_pointer(tp->root, head);
return 0;
}
static void __basic_delete_filter(struct basic_filter *f)
{
tcf_exts_destroy(&f->exts);
tcf_em_tree_destroy(&f->ematches);
tcf_exts_put_net(&f->exts);
free_percpu(f->pf);
kfree(f);
}
static void basic_delete_filter_work(struct work_struct *work)
{
struct basic_filter *f = container_of(to_rcu_work(work),
struct basic_filter,
rwork);
rtnl_lock();
__basic_delete_filter(f);
rtnl_unlock();
}
static void basic_destroy(struct tcf_proto *tp, bool rtnl_held,
struct netlink_ext_ack *extack)
{
struct basic_head *head = rtnl_dereference(tp->root);
struct basic_filter *f, *n;
list_for_each_entry_safe(f, n, &head->flist, link) {
list_del_rcu(&f->link);
tcf_unbind_filter(tp, &f->res);
idr_remove(&head->handle_idr, f->handle);
if (tcf_exts_get_net(&f->exts))
tcf_queue_work(&f->rwork, basic_delete_filter_work);
else
__basic_delete_filter(f);
}
idr_destroy(&head->handle_idr);
kfree_rcu(head, rcu);
}
static int basic_delete(struct tcf_proto *tp, void *arg, bool *last,
bool rtnl_held, struct netlink_ext_ack *extack)
{
struct basic_head *head = rtnl_dereference(tp->root);
struct basic_filter *f = arg;
list_del_rcu(&f->link);
tcf_unbind_filter(tp, &f->res);
idr_remove(&head->handle_idr, f->handle);
tcf_exts_get_net(&f->exts);
tcf_queue_work(&f->rwork, basic_delete_filter_work);
*last = list_empty(&head->flist);
return 0;
}
static const struct nla_policy basic_policy[TCA_BASIC_MAX + 1] = {
[TCA_BASIC_CLASSID] = { .type = NLA_U32 },
[TCA_BASIC_EMATCHES] = { .type = NLA_NESTED },
};
static int basic_set_parms(struct net *net, struct tcf_proto *tp,
struct basic_filter *f, unsigned long base,
struct nlattr **tb,
struct nlattr *est, u32 flags,
struct netlink_ext_ack *extack)
{
int err;
err = tcf_exts_validate(net, tp, tb, est, &f->exts, flags, extack);
if (err < 0)
return err;
err = tcf_em_tree_validate(tp, tb[TCA_BASIC_EMATCHES], &f->ematches);
if (err < 0)
return err;
if (tb[TCA_BASIC_CLASSID]) {
f->res.classid = nla_get_u32(tb[TCA_BASIC_CLASSID]);
tcf_bind_filter(tp, &f->res, base);
}
f->tp = tp;
return 0;
}
static int basic_change(struct net *net, struct sk_buff *in_skb,
struct tcf_proto *tp, unsigned long base, u32 handle,
struct nlattr **tca, void **arg,
u32 flags, struct netlink_ext_ack *extack)
{
int err;
struct basic_head *head = rtnl_dereference(tp->root);
struct nlattr *tb[TCA_BASIC_MAX + 1];
struct basic_filter *fold = (struct basic_filter *) *arg;
struct basic_filter *fnew;
if (tca[TCA_OPTIONS] == NULL)
return -EINVAL;
err = nla_parse_nested_deprecated(tb, TCA_BASIC_MAX, tca[TCA_OPTIONS],
basic_policy, NULL);
if (err < 0)
return err;
if (fold != NULL) {
if (handle && fold->handle != handle)
return -EINVAL;
}
fnew = kzalloc(sizeof(*fnew), GFP_KERNEL);
if (!fnew)
return -ENOBUFS;
err = tcf_exts_init(&fnew->exts, net, TCA_BASIC_ACT, TCA_BASIC_POLICE);
if (err < 0)
goto errout;
if (!handle) {
handle = 1;
err = idr_alloc_u32(&head->handle_idr, fnew, &handle,
INT_MAX, GFP_KERNEL);
} else if (!fold) {
err = idr_alloc_u32(&head->handle_idr, fnew, &handle,
handle, GFP_KERNEL);
}
if (err)
goto errout;
fnew->handle = handle;
fnew->pf = alloc_percpu(struct tc_basic_pcnt);
if (!fnew->pf) {
err = -ENOMEM;
goto errout;
}
err = basic_set_parms(net, tp, fnew, base, tb, tca[TCA_RATE], flags,
extack);
if (err < 0) {
if (!fold)
idr_remove(&head->handle_idr, fnew->handle);
goto errout;
}
*arg = fnew;
if (fold) {
idr_replace(&head->handle_idr, fnew, fnew->handle);
list_replace_rcu(&fold->link, &fnew->link);
tcf_unbind_filter(tp, &fold->res);
tcf_exts_get_net(&fold->exts);
tcf_queue_work(&fold->rwork, basic_delete_filter_work);
} else {
list_add_rcu(&fnew->link, &head->flist);
}
return 0;
errout:
free_percpu(fnew->pf);
tcf_exts_destroy(&fnew->exts);
kfree(fnew);
return err;
}
static void basic_walk(struct tcf_proto *tp, struct tcf_walker *arg,
bool rtnl_held)
{
struct basic_head *head = rtnl_dereference(tp->root);
struct basic_filter *f;
list_for_each_entry(f, &head->flist, link) {
if (arg->count < arg->skip)
goto skip;
if (arg->fn(tp, f, arg) < 0) {
arg->stop = 1;
break;
}
skip:
arg->count++;
}
}
static void basic_bind_class(void *fh, u32 classid, unsigned long cl, void *q,
unsigned long base)
{
struct basic_filter *f = fh;
if (f && f->res.classid == classid) {
if (cl)
__tcf_bind_filter(q, &f->res, base);
else
__tcf_unbind_filter(q, &f->res);
}
}
static int basic_dump(struct net *net, struct tcf_proto *tp, void *fh,
struct sk_buff *skb, struct tcmsg *t, bool rtnl_held)
{
struct tc_basic_pcnt gpf = {};
struct basic_filter *f = fh;
struct nlattr *nest;
int cpu;
if (f == NULL)
return skb->len;
t->tcm_handle = f->handle;
nest = nla_nest_start_noflag(skb, TCA_OPTIONS);
if (nest == NULL)
goto nla_put_failure;
if (f->res.classid &&
nla_put_u32(skb, TCA_BASIC_CLASSID, f->res.classid))
goto nla_put_failure;
for_each_possible_cpu(cpu) {
struct tc_basic_pcnt *pf = per_cpu_ptr(f->pf, cpu);
gpf.rcnt += pf->rcnt;
gpf.rhit += pf->rhit;
}
if (nla_put_64bit(skb, TCA_BASIC_PCNT,
sizeof(struct tc_basic_pcnt),
&gpf, TCA_BASIC_PAD))
goto nla_put_failure;
if (tcf_exts_dump(skb, &f->exts) < 0 ||
tcf_em_tree_dump(skb, &f->ematches, TCA_BASIC_EMATCHES) < 0)
goto nla_put_failure;
nla_nest_end(skb, nest);
if (tcf_exts_dump_stats(skb, &f->exts) < 0)
goto nla_put_failure;
return skb->len;
nla_put_failure:
nla_nest_cancel(skb, nest);
return -1;
}
static struct tcf_proto_ops cls_basic_ops __read_mostly = {
.kind = "basic",
.classify = basic_classify,
.init = basic_init,
.destroy = basic_destroy,
.get = basic_get,
.change = basic_change,
.delete = basic_delete,
.walk = basic_walk,
.dump = basic_dump,
.bind_class = basic_bind_class,
.owner = THIS_MODULE,
};
static int __init init_basic(void)
{
return register_tcf_proto_ops(&cls_basic_ops);
}
static void __exit exit_basic(void)
{
unregister_tcf_proto_ops(&cls_basic_ops);
}
module_init(init_basic)
module_exit(exit_basic)
MODULE_LICENSE("GPL");