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/*
* net/sched/pedit.c Generic packet editor
*
* 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: Jamal Hadi Salim (2002-4)
*/
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/skbuff.h>
#include <linux/rtnetlink.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <net/netlink.h>
#include <net/pkt_sched.h>
#include <linux/tc_act/tc_pedit.h>
#include <net/tc_act/tc_pedit.h>
#define PEDIT_TAB_MASK 15
static struct tcf_common *tcf_pedit_ht[PEDIT_TAB_MASK + 1];
static u32 pedit_idx_gen;
static DEFINE_RWLOCK(pedit_lock);
static struct tcf_hashinfo pedit_hash_info = {
.htab = tcf_pedit_ht,
.hmask = PEDIT_TAB_MASK,
.lock = &pedit_lock,
};
static const struct nla_policy pedit_policy[TCA_PEDIT_MAX + 1] = {
[TCA_PEDIT_PARMS] = { .len = sizeof(struct tc_pedit) },
};
static int tcf_pedit_init(struct nlattr *nla, struct nlattr *est,
struct tc_action *a, int ovr, int bind)
{
struct nlattr *tb[TCA_PEDIT_MAX + 1];
struct tc_pedit *parm;
int ret = 0, err;
struct tcf_pedit *p;
struct tcf_common *pc;
struct tc_pedit_key *keys = NULL;
int ksize;
if (nla == NULL)
return -EINVAL;
err = nla_parse_nested(tb, TCA_PEDIT_MAX, nla, pedit_policy);
if (err < 0)
return err;
if (tb[TCA_PEDIT_PARMS] == NULL)
return -EINVAL;
parm = nla_data(tb[TCA_PEDIT_PARMS]);
ksize = parm->nkeys * sizeof(struct tc_pedit_key);
if (nla_len(tb[TCA_PEDIT_PARMS]) < sizeof(*parm) + ksize)
return -EINVAL;
pc = tcf_hash_check(parm->index, a, bind, &pedit_hash_info);
if (!pc) {
if (!parm->nkeys)
return -EINVAL;
pc = tcf_hash_create(parm->index, est, a, sizeof(*p), bind,
&pedit_idx_gen, &pedit_hash_info);
if (IS_ERR(pc))
return PTR_ERR(pc);
p = to_pedit(pc);
keys = kmalloc(ksize, GFP_KERNEL);
if (keys == NULL) {
kfree(pc);
return -ENOMEM;
}
ret = ACT_P_CREATED;
} else {
p = to_pedit(pc);
if (!ovr) {
tcf_hash_release(pc, bind, &pedit_hash_info);
return -EEXIST;
}
if (p->tcfp_nkeys && p->tcfp_nkeys != parm->nkeys) {
keys = kmalloc(ksize, GFP_KERNEL);
if (keys == NULL)
return -ENOMEM;
}
}
spin_lock_bh(&p->tcf_lock);
p->tcfp_flags = parm->flags;
p->tcf_action = parm->action;
if (keys) {
kfree(p->tcfp_keys);
p->tcfp_keys = keys;
p->tcfp_nkeys = parm->nkeys;
}
memcpy(p->tcfp_keys, parm->keys, ksize);
spin_unlock_bh(&p->tcf_lock);
if (ret == ACT_P_CREATED)
tcf_hash_insert(pc, &pedit_hash_info);
return ret;
}
static int tcf_pedit_cleanup(struct tc_action *a, int bind)
{
struct tcf_pedit *p = a->priv;
if (p) {
struct tc_pedit_key *keys = p->tcfp_keys;
if (tcf_hash_release(&p->common, bind, &pedit_hash_info)) {
kfree(keys);
return 1;
}
}
return 0;
}
static int tcf_pedit(struct sk_buff *skb, const struct tc_action *a,
struct tcf_result *res)
{
struct tcf_pedit *p = a->priv;
int i, munged = 0;
unsigned int off;
if (skb_cloned(skb) &&
pskb_expand_head(skb, 0, 0, GFP_ATOMIC))
return p->tcf_action;
off = skb_network_offset(skb);
spin_lock(&p->tcf_lock);
p->tcf_tm.lastuse = jiffies;
if (p->tcfp_nkeys > 0) {
struct tc_pedit_key *tkey = p->tcfp_keys;
for (i = p->tcfp_nkeys; i > 0; i--, tkey++) {
u32 *ptr, _data;
int offset = tkey->off;
if (tkey->offmask) {
char *d, _d;
d = skb_header_pointer(skb, off + tkey->at, 1,
&_d);
if (!d)
goto bad;
offset += (*d & tkey->offmask) >> tkey->shift;
}
if (offset % 4) {
pr_info("tc filter pedit"
" offset must be on 32 bit boundaries\n");
goto bad;
}
if (offset > 0 && offset > skb->len) {
pr_info("tc filter pedit"
" offset %d can't exceed pkt length %d\n",
offset, skb->len);
goto bad;
}
ptr = skb_header_pointer(skb, off + offset, 4, &_data);
if (!ptr)
goto bad;
/* just do it, baby */
*ptr = ((*ptr & tkey->mask) ^ tkey->val);
if (ptr == &_data)
skb_store_bits(skb, off + offset, ptr, 4);
munged++;
}
if (munged)
skb->tc_verd = SET_TC_MUNGED(skb->tc_verd);
goto done;
} else
WARN(1, "pedit BUG: index %d\n", p->tcf_index);
bad:
p->tcf_qstats.overlimits++;
done:
bstats_update(&p->tcf_bstats, skb);
spin_unlock(&p->tcf_lock);
return p->tcf_action;
}
static int tcf_pedit_dump(struct sk_buff *skb, struct tc_action *a,
int bind, int ref)
{
unsigned char *b = skb_tail_pointer(skb);
struct tcf_pedit *p = a->priv;
struct tc_pedit *opt;
struct tcf_t t;
int s;
s = sizeof(*opt) + p->tcfp_nkeys * sizeof(struct tc_pedit_key);
/* netlink spinlocks held above us - must use ATOMIC */
opt = kzalloc(s, GFP_ATOMIC);
if (unlikely(!opt))
return -ENOBUFS;
memcpy(opt->keys, p->tcfp_keys,
p->tcfp_nkeys * sizeof(struct tc_pedit_key));
opt->index = p->tcf_index;
opt->nkeys = p->tcfp_nkeys;
opt->flags = p->tcfp_flags;
opt->action = p->tcf_action;
opt->refcnt = p->tcf_refcnt - ref;
opt->bindcnt = p->tcf_bindcnt - bind;
NLA_PUT(skb, TCA_PEDIT_PARMS, s, opt);
t.install = jiffies_to_clock_t(jiffies - p->tcf_tm.install);
t.lastuse = jiffies_to_clock_t(jiffies - p->tcf_tm.lastuse);
t.expires = jiffies_to_clock_t(p->tcf_tm.expires);
NLA_PUT(skb, TCA_PEDIT_TM, sizeof(t), &t);
kfree(opt);
return skb->len;
nla_put_failure:
nlmsg_trim(skb, b);
kfree(opt);
return -1;
}
static struct tc_action_ops act_pedit_ops = {
.kind = "pedit",
.hinfo = &pedit_hash_info,
.type = TCA_ACT_PEDIT,
.capab = TCA_CAP_NONE,
.owner = THIS_MODULE,
.act = tcf_pedit,
.dump = tcf_pedit_dump,
.cleanup = tcf_pedit_cleanup,
.lookup = tcf_hash_search,
.init = tcf_pedit_init,
.walk = tcf_generic_walker
};
MODULE_AUTHOR("Jamal Hadi Salim(2002-4)");
MODULE_DESCRIPTION("Generic Packet Editor actions");
MODULE_LICENSE("GPL");
static int __init pedit_init_module(void)
{
return tcf_register_action(&act_pedit_ops);
}
static void __exit pedit_cleanup_module(void)
{
tcf_unregister_action(&act_pedit_ops);
}
module_init(pedit_init_module);
module_exit(pedit_cleanup_module);
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