linux/net/sched/cls_basic.c

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/*
* net/sched/cls_basic.c Basic Packet Classifier.
*
* 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.
*
* Authors: Thomas Graf <tgraf@suug.ch>
*/
#include <linux/module.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 <net/netlink.h>
#include <net/act_api.h>
#include <net/pkt_cls.h>
struct basic_head
{
u32 hgenerator;
struct list_head flist;
};
struct basic_filter
{
u32 handle;
struct tcf_exts exts;
struct tcf_ematch_tree ematches;
struct tcf_result res;
struct list_head link;
};
static const struct tcf_ext_map basic_ext_map = {
.action = TCA_BASIC_ACT,
.police = TCA_BASIC_POLICE
};
static int basic_classify(struct sk_buff *skb, struct tcf_proto *tp,
struct tcf_result *res)
{
int r;
struct basic_head *head = (struct basic_head *) tp->root;
struct basic_filter *f;
list_for_each_entry(f, &head->flist, link) {
if (!tcf_em_tree_match(skb, &f->ematches, NULL))
continue;
*res = f->res;
r = tcf_exts_exec(skb, &f->exts, res);
if (r < 0)
continue;
return r;
}
return -1;
}
static unsigned long basic_get(struct tcf_proto *tp, u32 handle)
{
unsigned long l = 0UL;
struct basic_head *head = (struct basic_head *) tp->root;
struct basic_filter *f;
if (head == NULL)
return 0UL;
list_for_each_entry(f, &head->flist, link)
if (f->handle == handle)
l = (unsigned long) f;
return l;
}
static void basic_put(struct tcf_proto *tp, unsigned long f)
{
}
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);
tp->root = head;
return 0;
}
static inline void basic_delete_filter(struct tcf_proto *tp,
struct basic_filter *f)
{
tcf_unbind_filter(tp, &f->res);
tcf_exts_destroy(tp, &f->exts);
tcf_em_tree_destroy(tp, &f->ematches);
kfree(f);
}
static void basic_destroy(struct tcf_proto *tp)
{
struct basic_head *head = tp->root;
struct basic_filter *f, *n;
list_for_each_entry_safe(f, n, &head->flist, link) {
list_del(&f->link);
basic_delete_filter(tp, f);
}
kfree(head);
}
static int basic_delete(struct tcf_proto *tp, unsigned long arg)
{
struct basic_head *head = (struct basic_head *) tp->root;
struct basic_filter *t, *f = (struct basic_filter *) arg;
list_for_each_entry(t, &head->flist, link)
if (t == f) {
tcf_tree_lock(tp);
list_del(&t->link);
tcf_tree_unlock(tp);
basic_delete_filter(tp, t);
return 0;
}
return -ENOENT;
}
static const struct nla_policy basic_policy[TCA_BASIC_MAX + 1] = {
[TCA_BASIC_CLASSID] = { .type = NLA_U32 },
[TCA_BASIC_EMATCHES] = { .type = NLA_NESTED },
};
static inline int basic_set_parms(struct tcf_proto *tp, struct basic_filter *f,
unsigned long base, struct nlattr **tb,
struct nlattr *est)
{
int err = -EINVAL;
struct tcf_exts e;
struct tcf_ematch_tree t;
err = tcf_exts_validate(tp, tb, est, &e, &basic_ext_map);
if (err < 0)
return err;
err = tcf_em_tree_validate(tp, tb[TCA_BASIC_EMATCHES], &t);
if (err < 0)
goto errout;
if (tb[TCA_BASIC_CLASSID]) {
f->res.classid = nla_get_u32(tb[TCA_BASIC_CLASSID]);
tcf_bind_filter(tp, &f->res, base);
}
tcf_exts_change(tp, &f->exts, &e);
tcf_em_tree_change(tp, &f->ematches, &t);
return 0;
errout:
tcf_exts_destroy(tp, &e);
return err;
}
static int basic_change(struct tcf_proto *tp, unsigned long base, u32 handle,
struct nlattr **tca, unsigned long *arg)
{
int err;
struct basic_head *head = (struct basic_head *) tp->root;
struct nlattr *tb[TCA_BASIC_MAX + 1];
struct basic_filter *f = (struct basic_filter *) *arg;
if (tca[TCA_OPTIONS] == NULL)
return -EINVAL;
err = nla_parse_nested(tb, TCA_BASIC_MAX, tca[TCA_OPTIONS],
basic_policy);
if (err < 0)
return err;
if (f != NULL) {
if (handle && f->handle != handle)
return -EINVAL;
return basic_set_parms(tp, f, base, tb, tca[TCA_RATE]);
}
err = -ENOBUFS;
f = kzalloc(sizeof(*f), GFP_KERNEL);
if (f == NULL)
goto errout;
err = -EINVAL;
if (handle)
f->handle = handle;
else {
unsigned int i = 0x80000000;
do {
if (++head->hgenerator == 0x7FFFFFFF)
head->hgenerator = 1;
} while (--i > 0 && basic_get(tp, head->hgenerator));
if (i <= 0) {
printk(KERN_ERR "Insufficient number of handles\n");
goto errout;
}
f->handle = head->hgenerator;
}
err = basic_set_parms(tp, f, base, tb, tca[TCA_RATE]);
if (err < 0)
goto errout;
tcf_tree_lock(tp);
list_add(&f->link, &head->flist);
tcf_tree_unlock(tp);
*arg = (unsigned long) f;
return 0;
errout:
if (*arg == 0UL && f)
kfree(f);
return err;
}
static void basic_walk(struct tcf_proto *tp, struct tcf_walker *arg)
{
struct basic_head *head = (struct basic_head *) 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, (unsigned long) f, arg) < 0) {
arg->stop = 1;
break;
}
skip:
arg->count++;
}
}
static int basic_dump(struct tcf_proto *tp, unsigned long fh,
struct sk_buff *skb, struct tcmsg *t)
{
struct basic_filter *f = (struct basic_filter *) fh;
struct nlattr *nest;
if (f == NULL)
return skb->len;
t->tcm_handle = f->handle;
nest = nla_nest_start(skb, TCA_OPTIONS);
if (nest == NULL)
goto nla_put_failure;
if (f->res.classid)
NLA_PUT_U32(skb, TCA_BASIC_CLASSID, f->res.classid);
if (tcf_exts_dump(skb, &f->exts, &basic_ext_map) < 0 ||
tcf_em_tree_dump(skb, &f->ematches, TCA_BASIC_EMATCHES) < 0)
goto nla_put_failure;
nla_nest_end(skb, nest);
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,
.put = basic_put,
.change = basic_change,
.delete = basic_delete,
.walk = basic_walk,
.dump = basic_dump,
.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");