root/net/sched/act_skbedit.c

DEFINITIONS

1. tcf_skbedit
2. tcf_skbedit_init
3. tcf_skbedit_cleanup
4. tcf_skbedit_dump
5. skbedit_init_module
6. skbedit_cleanup_module

/*
 * Copyright (c) 2008, Intel Corporation.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License along with
 * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
 * Place - Suite 330, Boston, MA 02111-1307 USA.
 *
 * Author: Alexander Duyck <alexander.h.duyck@intel.com>
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/skbuff.h>
#include <linux/rtnetlink.h>
#include <net/netlink.h>
#include <net/pkt_sched.h>

#include <linux/tc_act/tc_skbedit.h>
#include <net/tc_act/tc_skbedit.h>

#define SKBEDIT_TAB_MASK     15
static struct tcf_common *tcf_skbedit_ht[SKBEDIT_TAB_MASK + 1];
static u32 skbedit_idx_gen;
static DEFINE_RWLOCK(skbedit_lock);

static struct tcf_hashinfo skbedit_hash_info = {
        .htab   =       tcf_skbedit_ht,
        .hmask  =       SKBEDIT_TAB_MASK,
        .lock   =       &skbedit_lock,
};

static int tcf_skbedit(struct sk_buff *skb, struct tc_action *a,
                       struct tcf_result *res)
{
        struct tcf_skbedit *d = a->priv;

        spin_lock(&d->tcf_lock);
        d->tcf_tm.lastuse = jiffies;
        d->tcf_bstats.bytes += qdisc_pkt_len(skb);
        d->tcf_bstats.packets++;

        if (d->flags & SKBEDIT_F_PRIORITY)
                skb->priority = d->priority;
        if (d->flags & SKBEDIT_F_QUEUE_MAPPING &&
            skb->dev->real_num_tx_queues > d->queue_mapping)
                skb_set_queue_mapping(skb, d->queue_mapping);

        spin_unlock(&d->tcf_lock);
        return d->tcf_action;
}

static const struct nla_policy skbedit_policy[TCA_SKBEDIT_MAX + 1] = {
        [TCA_SKBEDIT_PARMS]             = { .len = sizeof(struct tc_skbedit) },
        [TCA_SKBEDIT_PRIORITY]          = { .len = sizeof(u32) },
        [TCA_SKBEDIT_QUEUE_MAPPING]     = { .len = sizeof(u16) },
};

static int tcf_skbedit_init(struct nlattr *nla, struct nlattr *est,
                         struct tc_action *a, int ovr, int bind)
{
        struct nlattr *tb[TCA_SKBEDIT_MAX + 1];
        struct tc_skbedit *parm;
        struct tcf_skbedit *d;
        struct tcf_common *pc;
        u32 flags = 0, *priority = NULL;
        u16 *queue_mapping = NULL;
        int ret = 0, err;

        if (nla == NULL)
                return -EINVAL;

        err = nla_parse_nested(tb, TCA_SKBEDIT_MAX, nla, skbedit_policy);
        if (err < 0)
                return err;

        if (tb[TCA_SKBEDIT_PARMS] == NULL)
                return -EINVAL;

        if (tb[TCA_SKBEDIT_PRIORITY] != NULL) {
                flags |= SKBEDIT_F_PRIORITY;
                priority = nla_data(tb[TCA_SKBEDIT_PRIORITY]);
        }

        if (tb[TCA_SKBEDIT_QUEUE_MAPPING] != NULL) {
                flags |= SKBEDIT_F_QUEUE_MAPPING;
                queue_mapping = nla_data(tb[TCA_SKBEDIT_QUEUE_MAPPING]);
        }
        if (!flags)
                return -EINVAL;

        parm = nla_data(tb[TCA_SKBEDIT_PARMS]);

        pc = tcf_hash_check(parm->index, a, bind, &skbedit_hash_info);
        if (!pc) {
                pc = tcf_hash_create(parm->index, est, a, sizeof(*d), bind,
                                     &skbedit_idx_gen, &skbedit_hash_info);
                if (unlikely(!pc))
                        return -ENOMEM;

                d = to_skbedit(pc);
                ret = ACT_P_CREATED;
        } else {
                d = to_skbedit(pc);
                if (!ovr) {
                        tcf_hash_release(pc, bind, &skbedit_hash_info);
                        return -EEXIST;
                }
        }

        spin_lock_bh(&d->tcf_lock);

        d->flags = flags;
        if (flags & SKBEDIT_F_PRIORITY)
                d->priority = *priority;
        if (flags & SKBEDIT_F_QUEUE_MAPPING)
                d->queue_mapping = *queue_mapping;
        d->tcf_action = parm->action;

        spin_unlock_bh(&d->tcf_lock);

        if (ret == ACT_P_CREATED)
                tcf_hash_insert(pc, &skbedit_hash_info);
        return ret;
}

static inline int tcf_skbedit_cleanup(struct tc_action *a, int bind)
{
        struct tcf_skbedit *d = a->priv;

        if (d)
                return tcf_hash_release(&d->common, bind, &skbedit_hash_info);
        return 0;
}

static inline int tcf_skbedit_dump(struct sk_buff *skb, struct tc_action *a,
                                int bind, int ref)
{
        unsigned char *b = skb_tail_pointer(skb);
        struct tcf_skbedit *d = a->priv;
        struct tc_skbedit opt;
        struct tcf_t t;

        opt.index = d->tcf_index;
        opt.refcnt = d->tcf_refcnt - ref;
        opt.bindcnt = d->tcf_bindcnt - bind;
        opt.action = d->tcf_action;
        NLA_PUT(skb, TCA_SKBEDIT_PARMS, sizeof(opt), &opt);
        if (d->flags & SKBEDIT_F_PRIORITY)
                NLA_PUT(skb, TCA_SKBEDIT_PRIORITY, sizeof(d->priority),
                        &d->priority);
        if (d->flags & SKBEDIT_F_QUEUE_MAPPING)
                NLA_PUT(skb, TCA_SKBEDIT_QUEUE_MAPPING,
                        sizeof(d->queue_mapping), &d->queue_mapping);
        t.install = jiffies_to_clock_t(jiffies - d->tcf_tm.install);
        t.lastuse = jiffies_to_clock_t(jiffies - d->tcf_tm.lastuse);
        t.expires = jiffies_to_clock_t(d->tcf_tm.expires);
        NLA_PUT(skb, TCA_SKBEDIT_TM, sizeof(t), &t);
        return skb->len;

nla_put_failure:
        nlmsg_trim(skb, b);
        return -1;
}

static struct tc_action_ops act_skbedit_ops = {
        .kind           =       "skbedit",
        .hinfo          =       &skbedit_hash_info,
        .type           =       TCA_ACT_SKBEDIT,
        .capab          =       TCA_CAP_NONE,
        .owner          =       THIS_MODULE,
        .act            =       tcf_skbedit,
        .dump           =       tcf_skbedit_dump,
        .cleanup        =       tcf_skbedit_cleanup,
        .init           =       tcf_skbedit_init,
        .walk           =       tcf_generic_walker,
};

MODULE_AUTHOR("Alexander Duyck, <alexander.h.duyck@intel.com>");
MODULE_DESCRIPTION("SKB Editing");
MODULE_LICENSE("GPL");

static int __init skbedit_init_module(void)
{
        return tcf_register_action(&act_skbedit_ops);
}

static void __exit skbedit_cleanup_module(void)
{
        tcf_unregister_action(&act_skbedit_ops);
}

module_init(skbedit_init_module);
module_exit(skbedit_cleanup_module);