linux/net/sched/cls_fw.c
Patrick McHardy 47a1a1d4be pkt_sched: remove unnecessary xchg() in packet classifiers
The use of xchg() hasn't been necessary since 2.2.something when proper
locking was added to packet schedulers. In the case of classifiers they
mostly weren't even necessary before that since they're mainly used
to assign a NULL pointer to the filter root in the ->destroy path;
the root is destroyed immediately after that.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-20 04:14:28 -08:00

401 lines
8.3 KiB
C

/*
* net/sched/cls_fw.c Classifier mapping ipchains' fwmark to traffic class.
*
* 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: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
*
* Changes:
* Karlis Peisenieks <karlis@mt.lv> : 990415 : fw_walk off by one
* Karlis Peisenieks <karlis@mt.lv> : 990415 : fw_delete killed all the filter (and kernel).
* Alex <alex@pilotsoft.com> : 2004xxyy: Added Action extension
*
* JHS: We should remove the CONFIG_NET_CLS_IND from here
* eventually when the meta match extension is made available
*
*/
#include <linux/module.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/skbuff.h>
#include <net/netlink.h>
#include <net/act_api.h>
#include <net/pkt_cls.h>
#define HTSIZE (PAGE_SIZE/sizeof(struct fw_filter *))
struct fw_head
{
struct fw_filter *ht[HTSIZE];
u32 mask;
};
struct fw_filter
{
struct fw_filter *next;
u32 id;
struct tcf_result res;
#ifdef CONFIG_NET_CLS_IND
char indev[IFNAMSIZ];
#endif /* CONFIG_NET_CLS_IND */
struct tcf_exts exts;
};
static const struct tcf_ext_map fw_ext_map = {
.action = TCA_FW_ACT,
.police = TCA_FW_POLICE
};
static __inline__ int fw_hash(u32 handle)
{
if (HTSIZE == 4096)
return ((handle >> 24) & 0xFFF) ^
((handle >> 12) & 0xFFF) ^
(handle & 0xFFF);
else if (HTSIZE == 2048)
return ((handle >> 22) & 0x7FF) ^
((handle >> 11) & 0x7FF) ^
(handle & 0x7FF);
else if (HTSIZE == 1024)
return ((handle >> 20) & 0x3FF) ^
((handle >> 10) & 0x3FF) ^
(handle & 0x3FF);
else if (HTSIZE == 512)
return (handle >> 27) ^
((handle >> 18) & 0x1FF) ^
((handle >> 9) & 0x1FF) ^
(handle & 0x1FF);
else if (HTSIZE == 256) {
u8 *t = (u8 *) &handle;
return t[0] ^ t[1] ^ t[2] ^ t[3];
} else
return handle & (HTSIZE - 1);
}
static int fw_classify(struct sk_buff *skb, struct tcf_proto *tp,
struct tcf_result *res)
{
struct fw_head *head = (struct fw_head*)tp->root;
struct fw_filter *f;
int r;
u32 id = skb->mark;
if (head != NULL) {
id &= head->mask;
for (f=head->ht[fw_hash(id)]; f; f=f->next) {
if (f->id == id) {
*res = f->res;
#ifdef CONFIG_NET_CLS_IND
if (!tcf_match_indev(skb, f->indev))
continue;
#endif /* CONFIG_NET_CLS_IND */
r = tcf_exts_exec(skb, &f->exts, res);
if (r < 0)
continue;
return r;
}
}
} else {
/* old method */
if (id && (TC_H_MAJ(id) == 0 || !(TC_H_MAJ(id^tp->q->handle)))) {
res->classid = id;
res->class = 0;
return 0;
}
}
return -1;
}
static unsigned long fw_get(struct tcf_proto *tp, u32 handle)
{
struct fw_head *head = (struct fw_head*)tp->root;
struct fw_filter *f;
if (head == NULL)
return 0;
for (f=head->ht[fw_hash(handle)]; f; f=f->next) {
if (f->id == handle)
return (unsigned long)f;
}
return 0;
}
static void fw_put(struct tcf_proto *tp, unsigned long f)
{
}
static int fw_init(struct tcf_proto *tp)
{
return 0;
}
static inline void
fw_delete_filter(struct tcf_proto *tp, struct fw_filter *f)
{
tcf_unbind_filter(tp, &f->res);
tcf_exts_destroy(tp, &f->exts);
kfree(f);
}
static void fw_destroy(struct tcf_proto *tp)
{
struct fw_head *head = tp->root;
struct fw_filter *f;
int h;
if (head == NULL)
return;
for (h=0; h<HTSIZE; h++) {
while ((f=head->ht[h]) != NULL) {
head->ht[h] = f->next;
fw_delete_filter(tp, f);
}
}
kfree(head);
}
static int fw_delete(struct tcf_proto *tp, unsigned long arg)
{
struct fw_head *head = (struct fw_head*)tp->root;
struct fw_filter *f = (struct fw_filter*)arg;
struct fw_filter **fp;
if (head == NULL || f == NULL)
goto out;
for (fp=&head->ht[fw_hash(f->id)]; *fp; fp = &(*fp)->next) {
if (*fp == f) {
tcf_tree_lock(tp);
*fp = f->next;
tcf_tree_unlock(tp);
fw_delete_filter(tp, f);
return 0;
}
}
out:
return -EINVAL;
}
static const struct nla_policy fw_policy[TCA_FW_MAX + 1] = {
[TCA_FW_CLASSID] = { .type = NLA_U32 },
[TCA_FW_INDEV] = { .type = NLA_STRING, .len = IFNAMSIZ },
[TCA_FW_MASK] = { .type = NLA_U32 },
};
static int
fw_change_attrs(struct tcf_proto *tp, struct fw_filter *f,
struct nlattr **tb, struct nlattr **tca, unsigned long base)
{
struct fw_head *head = (struct fw_head *)tp->root;
struct tcf_exts e;
u32 mask;
int err;
err = tcf_exts_validate(tp, tb, tca[TCA_RATE], &e, &fw_ext_map);
if (err < 0)
return err;
err = -EINVAL;
if (tb[TCA_FW_CLASSID]) {
f->res.classid = nla_get_u32(tb[TCA_FW_CLASSID]);
tcf_bind_filter(tp, &f->res, base);
}
#ifdef CONFIG_NET_CLS_IND
if (tb[TCA_FW_INDEV]) {
err = tcf_change_indev(tp, f->indev, tb[TCA_FW_INDEV]);
if (err < 0)
goto errout;
}
#endif /* CONFIG_NET_CLS_IND */
if (tb[TCA_FW_MASK]) {
mask = nla_get_u32(tb[TCA_FW_MASK]);
if (mask != head->mask)
goto errout;
} else if (head->mask != 0xFFFFFFFF)
goto errout;
tcf_exts_change(tp, &f->exts, &e);
return 0;
errout:
tcf_exts_destroy(tp, &e);
return err;
}
static int fw_change(struct tcf_proto *tp, unsigned long base,
u32 handle,
struct nlattr **tca,
unsigned long *arg)
{
struct fw_head *head = (struct fw_head*)tp->root;
struct fw_filter *f = (struct fw_filter *) *arg;
struct nlattr *opt = tca[TCA_OPTIONS];
struct nlattr *tb[TCA_FW_MAX + 1];
int err;
if (!opt)
return handle ? -EINVAL : 0;
err = nla_parse_nested(tb, TCA_FW_MAX, opt, fw_policy);
if (err < 0)
return err;
if (f != NULL) {
if (f->id != handle && handle)
return -EINVAL;
return fw_change_attrs(tp, f, tb, tca, base);
}
if (!handle)
return -EINVAL;
if (head == NULL) {
u32 mask = 0xFFFFFFFF;
if (tb[TCA_FW_MASK])
mask = nla_get_u32(tb[TCA_FW_MASK]);
head = kzalloc(sizeof(struct fw_head), GFP_KERNEL);
if (head == NULL)
return -ENOBUFS;
head->mask = mask;
tcf_tree_lock(tp);
tp->root = head;
tcf_tree_unlock(tp);
}
f = kzalloc(sizeof(struct fw_filter), GFP_KERNEL);
if (f == NULL)
return -ENOBUFS;
f->id = handle;
err = fw_change_attrs(tp, f, tb, tca, base);
if (err < 0)
goto errout;
f->next = head->ht[fw_hash(handle)];
tcf_tree_lock(tp);
head->ht[fw_hash(handle)] = f;
tcf_tree_unlock(tp);
*arg = (unsigned long)f;
return 0;
errout:
kfree(f);
return err;
}
static void fw_walk(struct tcf_proto *tp, struct tcf_walker *arg)
{
struct fw_head *head = (struct fw_head*)tp->root;
int h;
if (head == NULL)
arg->stop = 1;
if (arg->stop)
return;
for (h = 0; h < HTSIZE; h++) {
struct fw_filter *f;
for (f = head->ht[h]; f; f = f->next) {
if (arg->count < arg->skip) {
arg->count++;
continue;
}
if (arg->fn(tp, (unsigned long)f, arg) < 0) {
arg->stop = 1;
return;
}
arg->count++;
}
}
}
static int fw_dump(struct tcf_proto *tp, unsigned long fh,
struct sk_buff *skb, struct tcmsg *t)
{
struct fw_head *head = (struct fw_head *)tp->root;
struct fw_filter *f = (struct fw_filter*)fh;
unsigned char *b = skb_tail_pointer(skb);
struct nlattr *nest;
if (f == NULL)
return skb->len;
t->tcm_handle = f->id;
if (!f->res.classid && !tcf_exts_is_available(&f->exts))
return skb->len;
nest = nla_nest_start(skb, TCA_OPTIONS);
if (nest == NULL)
goto nla_put_failure;
if (f->res.classid)
NLA_PUT_U32(skb, TCA_FW_CLASSID, f->res.classid);
#ifdef CONFIG_NET_CLS_IND
if (strlen(f->indev))
NLA_PUT_STRING(skb, TCA_FW_INDEV, f->indev);
#endif /* CONFIG_NET_CLS_IND */
if (head->mask != 0xFFFFFFFF)
NLA_PUT_U32(skb, TCA_FW_MASK, head->mask);
if (tcf_exts_dump(skb, &f->exts, &fw_ext_map) < 0)
goto nla_put_failure;
nla_nest_end(skb, nest);
if (tcf_exts_dump_stats(skb, &f->exts, &fw_ext_map) < 0)
goto nla_put_failure;
return skb->len;
nla_put_failure:
nlmsg_trim(skb, b);
return -1;
}
static struct tcf_proto_ops cls_fw_ops __read_mostly = {
.kind = "fw",
.classify = fw_classify,
.init = fw_init,
.destroy = fw_destroy,
.get = fw_get,
.put = fw_put,
.change = fw_change,
.delete = fw_delete,
.walk = fw_walk,
.dump = fw_dump,
.owner = THIS_MODULE,
};
static int __init init_fw(void)
{
return register_tcf_proto_ops(&cls_fw_ops);
}
static void __exit exit_fw(void)
{
unregister_tcf_proto_ops(&cls_fw_ops);
}
module_init(init_fw)
module_exit(exit_fw)
MODULE_LICENSE("GPL");