linux/net/sched/cls_fw.c
WANG Cong d8aecb1011 net: revert "net_sched: move tp->root allocation into fw_init()"
fw filter uses tp->root==NULL to check if it is the old method,
so it doesn't need allocation at all in this case. This patch
reverts the offending commit and adds some comments for old
method to make it obvious.

Fixes: 33f8b9ecdb ("net_sched: move tp->root allocation into fw_init()")
Reported-by: Akshat Kakkar <akshat.1984@gmail.com>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-09-24 14:33:30 -07:00

439 lines
9.5 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/slab.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 256
struct fw_head {
u32 mask;
struct fw_filter __rcu *ht[HTSIZE];
struct rcu_head rcu;
};
struct fw_filter {
struct fw_filter __rcu *next;
u32 id;
struct tcf_result res;
#ifdef CONFIG_NET_CLS_IND
int ifindex;
#endif /* CONFIG_NET_CLS_IND */
struct tcf_exts exts;
struct tcf_proto *tp;
struct rcu_head rcu;
};
static u32 fw_hash(u32 handle)
{
handle ^= (handle >> 16);
handle ^= (handle >> 8);
return handle % HTSIZE;
}
static int fw_classify(struct sk_buff *skb, const struct tcf_proto *tp,
struct tcf_result *res)
{
struct fw_head *head = rcu_dereference_bh(tp->root);
struct fw_filter *f;
int r;
u32 id = skb->mark;
if (head != NULL) {
id &= head->mask;
for (f = rcu_dereference_bh(head->ht[fw_hash(id)]); f;
f = rcu_dereference_bh(f->next)) {
if (f->id == id) {
*res = f->res;
#ifdef CONFIG_NET_CLS_IND
if (!tcf_match_indev(skb, f->ifindex))
continue;
#endif /* CONFIG_NET_CLS_IND */
r = tcf_exts_exec(skb, &f->exts, res);
if (r < 0)
continue;
return r;
}
}
} else {
/* Old method: classify the packet using its skb mark. */
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 = rtnl_dereference(tp->root);
struct fw_filter *f;
if (head == NULL)
return 0;
f = rtnl_dereference(head->ht[fw_hash(handle)]);
for (; f; f = rtnl_dereference(f->next)) {
if (f->id == handle)
return (unsigned long)f;
}
return 0;
}
static int fw_init(struct tcf_proto *tp)
{
/* We don't allocate fw_head here, because in the old method
* we don't need it at all.
*/
return 0;
}
static void fw_delete_filter(struct rcu_head *head)
{
struct fw_filter *f = container_of(head, struct fw_filter, rcu);
tcf_exts_destroy(&f->exts);
kfree(f);
}
static bool fw_destroy(struct tcf_proto *tp, bool force)
{
struct fw_head *head = rtnl_dereference(tp->root);
struct fw_filter *f;
int h;
if (head == NULL)
return true;
if (!force) {
for (h = 0; h < HTSIZE; h++)
if (rcu_access_pointer(head->ht[h]))
return false;
}
for (h = 0; h < HTSIZE; h++) {
while ((f = rtnl_dereference(head->ht[h])) != NULL) {
RCU_INIT_POINTER(head->ht[h],
rtnl_dereference(f->next));
tcf_unbind_filter(tp, &f->res);
call_rcu(&f->rcu, fw_delete_filter);
}
}
RCU_INIT_POINTER(tp->root, NULL);
kfree_rcu(head, rcu);
return true;
}
static int fw_delete(struct tcf_proto *tp, unsigned long arg)
{
struct fw_head *head = rtnl_dereference(tp->root);
struct fw_filter *f = (struct fw_filter *)arg;
struct fw_filter __rcu **fp;
struct fw_filter *pfp;
if (head == NULL || f == NULL)
goto out;
fp = &head->ht[fw_hash(f->id)];
for (pfp = rtnl_dereference(*fp); pfp;
fp = &pfp->next, pfp = rtnl_dereference(*fp)) {
if (pfp == f) {
RCU_INIT_POINTER(*fp, rtnl_dereference(f->next));
tcf_unbind_filter(tp, &f->res);
call_rcu(&f->rcu, fw_delete_filter);
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 net *net, struct tcf_proto *tp, struct fw_filter *f,
struct nlattr **tb, struct nlattr **tca, unsigned long base, bool ovr)
{
struct fw_head *head = rtnl_dereference(tp->root);
struct tcf_exts e;
u32 mask;
int err;
tcf_exts_init(&e, TCA_FW_ACT, TCA_FW_POLICE);
err = tcf_exts_validate(net, tp, tb, tca[TCA_RATE], &e, ovr);
if (err < 0)
return err;
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]) {
int ret;
ret = tcf_change_indev(net, tb[TCA_FW_INDEV]);
if (ret < 0) {
err = ret;
goto errout;
}
f->ifindex = ret;
}
#endif /* CONFIG_NET_CLS_IND */
err = -EINVAL;
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(&e);
return err;
}
static int fw_change(struct net *net, struct sk_buff *in_skb,
struct tcf_proto *tp, unsigned long base,
u32 handle,
struct nlattr **tca,
unsigned long *arg, bool ovr)
{
struct fw_head *head = rtnl_dereference(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; /* Succeed if it is old method. */
err = nla_parse_nested(tb, TCA_FW_MAX, opt, fw_policy);
if (err < 0)
return err;
if (f) {
struct fw_filter *pfp, *fnew;
struct fw_filter __rcu **fp;
if (f->id != handle && handle)
return -EINVAL;
fnew = kzalloc(sizeof(struct fw_filter), GFP_KERNEL);
if (!fnew)
return -ENOBUFS;
fnew->id = f->id;
fnew->res = f->res;
#ifdef CONFIG_NET_CLS_IND
fnew->ifindex = f->ifindex;
#endif /* CONFIG_NET_CLS_IND */
fnew->tp = f->tp;
tcf_exts_init(&fnew->exts, TCA_FW_ACT, TCA_FW_POLICE);
err = fw_change_attrs(net, tp, fnew, tb, tca, base, ovr);
if (err < 0) {
kfree(fnew);
return err;
}
fp = &head->ht[fw_hash(fnew->id)];
for (pfp = rtnl_dereference(*fp); pfp;
fp = &pfp->next, pfp = rtnl_dereference(*fp))
if (pfp == f)
break;
RCU_INIT_POINTER(fnew->next, rtnl_dereference(pfp->next));
rcu_assign_pointer(*fp, fnew);
tcf_unbind_filter(tp, &f->res);
call_rcu(&f->rcu, fw_delete_filter);
*arg = (unsigned long)fnew;
return err;
}
if (!handle)
return -EINVAL;
if (!head) {
u32 mask = 0xFFFFFFFF;
if (tb[TCA_FW_MASK])
mask = nla_get_u32(tb[TCA_FW_MASK]);
head = kzalloc(sizeof(*head), GFP_KERNEL);
if (!head)
return -ENOBUFS;
head->mask = mask;
rcu_assign_pointer(tp->root, head);
}
f = kzalloc(sizeof(struct fw_filter), GFP_KERNEL);
if (f == NULL)
return -ENOBUFS;
tcf_exts_init(&f->exts, TCA_FW_ACT, TCA_FW_POLICE);
f->id = handle;
f->tp = tp;
err = fw_change_attrs(net, tp, f, tb, tca, base, ovr);
if (err < 0)
goto errout;
RCU_INIT_POINTER(f->next, head->ht[fw_hash(handle)]);
rcu_assign_pointer(head->ht[fw_hash(handle)], f);
*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 = rtnl_dereference(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 = rtnl_dereference(head->ht[h]); f;
f = rtnl_dereference(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 net *net, struct tcf_proto *tp, unsigned long fh,
struct sk_buff *skb, struct tcmsg *t)
{
struct fw_head *head = rtnl_dereference(tp->root);
struct fw_filter *f = (struct fw_filter *)fh;
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))
goto nla_put_failure;
#ifdef CONFIG_NET_CLS_IND
if (f->ifindex) {
struct net_device *dev;
dev = __dev_get_by_index(net, f->ifindex);
if (dev && nla_put_string(skb, TCA_FW_INDEV, dev->name))
goto nla_put_failure;
}
#endif /* CONFIG_NET_CLS_IND */
if (head->mask != 0xFFFFFFFF &&
nla_put_u32(skb, TCA_FW_MASK, head->mask))
goto nla_put_failure;
if (tcf_exts_dump(skb, &f->exts) < 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_fw_ops __read_mostly = {
.kind = "fw",
.classify = fw_classify,
.init = fw_init,
.destroy = fw_destroy,
.get = fw_get,
.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");