root/net/sched/act_gact.c

DEFINITIONS

1. gact_net_rand
2. gact_determ
3. tcf_gact_init
4. tcf_gact_cleanup
5. tcf_gact
6. tcf_gact_dump
7. gact_init_module
8. gact_cleanup_module

/*
 * net/sched/gact.c     Generic actions
 *
 *              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.
 *
 * copyright    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 <net/netlink.h>
#include <net/pkt_sched.h>
#include <linux/tc_act/tc_gact.h>
#include <net/tc_act/tc_gact.h>

#define GACT_TAB_MASK   15
static struct tcf_common *tcf_gact_ht[GACT_TAB_MASK + 1];
static u32 gact_idx_gen;
static DEFINE_RWLOCK(gact_lock);

static struct tcf_hashinfo gact_hash_info = {
        .htab   =       tcf_gact_ht,
        .hmask  =       GACT_TAB_MASK,
        .lock   =       &gact_lock,
};

#ifdef CONFIG_GACT_PROB
static int gact_net_rand(struct tcf_gact *gact)
{
        if (!gact->tcfg_pval || net_random() % gact->tcfg_pval)
                return gact->tcf_action;
        return gact->tcfg_paction;
}

static int gact_determ(struct tcf_gact *gact)
{
        if (!gact->tcfg_pval || gact->tcf_bstats.packets % gact->tcfg_pval)
                return gact->tcf_action;
        return gact->tcfg_paction;
}

typedef int (*g_rand)(struct tcf_gact *gact);
static g_rand gact_rand[MAX_RAND]= { NULL, gact_net_rand, gact_determ };
#endif /* CONFIG_GACT_PROB */

static const struct nla_policy gact_policy[TCA_GACT_MAX + 1] = {
        [TCA_GACT_PARMS]        = { .len = sizeof(struct tc_gact) },
        [TCA_GACT_PROB]         = { .len = sizeof(struct tc_gact_p) },
};

static int tcf_gact_init(struct nlattr *nla, struct nlattr *est,
                         struct tc_action *a, int ovr, int bind)
{
        struct nlattr *tb[TCA_GACT_MAX + 1];
        struct tc_gact *parm;
        struct tcf_gact *gact;
        struct tcf_common *pc;
        int ret = 0;
        int err;

        if (nla == NULL)
                return -EINVAL;

        err = nla_parse_nested(tb, TCA_GACT_MAX, nla, gact_policy);
        if (err < 0)
                return err;

        if (tb[TCA_GACT_PARMS] == NULL)
                return -EINVAL;
        parm = nla_data(tb[TCA_GACT_PARMS]);

#ifndef CONFIG_GACT_PROB
        if (tb[TCA_GACT_PROB] != NULL)
                return -EOPNOTSUPP;
#endif

        pc = tcf_hash_check(parm->index, a, bind, &gact_hash_info);
        if (!pc) {
                pc = tcf_hash_create(parm->index, est, a, sizeof(*gact),
                                     bind, &gact_idx_gen, &gact_hash_info);
                if (unlikely(!pc))
                        return -ENOMEM;
                ret = ACT_P_CREATED;
        } else {
                if (!ovr) {
                        tcf_hash_release(pc, bind, &gact_hash_info);
                        return -EEXIST;
                }
        }

        gact = to_gact(pc);

        spin_lock_bh(&gact->tcf_lock);
        gact->tcf_action = parm->action;
#ifdef CONFIG_GACT_PROB
        if (tb[TCA_GACT_PROB] != NULL) {
                struct tc_gact_p *p_parm = nla_data(tb[TCA_GACT_PROB]);
                gact->tcfg_paction = p_parm->paction;
                gact->tcfg_pval    = p_parm->pval;
                gact->tcfg_ptype   = p_parm->ptype;
        }
#endif
        spin_unlock_bh(&gact->tcf_lock);
        if (ret == ACT_P_CREATED)
                tcf_hash_insert(pc, &gact_hash_info);
        return ret;
}

static int tcf_gact_cleanup(struct tc_action *a, int bind)
{
        struct tcf_gact *gact = a->priv;

        if (gact)
                return tcf_hash_release(&gact->common, bind, &gact_hash_info);
        return 0;
}

static int tcf_gact(struct sk_buff *skb, struct tc_action *a, struct tcf_result *res)
{
        struct tcf_gact *gact = a->priv;
        int action = TC_ACT_SHOT;

        spin_lock(&gact->tcf_lock);
#ifdef CONFIG_GACT_PROB
        if (gact->tcfg_ptype && gact_rand[gact->tcfg_ptype] != NULL)
                action = gact_rand[gact->tcfg_ptype](gact);
        else
                action = gact->tcf_action;
#else
        action = gact->tcf_action;
#endif
        gact->tcf_bstats.bytes += qdisc_pkt_len(skb);
        gact->tcf_bstats.packets++;
        if (action == TC_ACT_SHOT)
                gact->tcf_qstats.drops++;
        gact->tcf_tm.lastuse = jiffies;
        spin_unlock(&gact->tcf_lock);

        return action;
}

static int tcf_gact_dump(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
{
        unsigned char *b = skb_tail_pointer(skb);
        struct tc_gact opt;
        struct tcf_gact *gact = a->priv;
        struct tcf_t t;

        opt.index = gact->tcf_index;
        opt.refcnt = gact->tcf_refcnt - ref;
        opt.bindcnt = gact->tcf_bindcnt - bind;
        opt.action = gact->tcf_action;
        NLA_PUT(skb, TCA_GACT_PARMS, sizeof(opt), &opt);
#ifdef CONFIG_GACT_PROB
        if (gact->tcfg_ptype) {
                struct tc_gact_p p_opt;
                p_opt.paction = gact->tcfg_paction;
                p_opt.pval = gact->tcfg_pval;
                p_opt.ptype = gact->tcfg_ptype;
                NLA_PUT(skb, TCA_GACT_PROB, sizeof(p_opt), &p_opt);
        }
#endif
        t.install = jiffies_to_clock_t(jiffies - gact->tcf_tm.install);
        t.lastuse = jiffies_to_clock_t(jiffies - gact->tcf_tm.lastuse);
        t.expires = jiffies_to_clock_t(gact->tcf_tm.expires);
        NLA_PUT(skb, TCA_GACT_TM, sizeof(t), &t);
        return skb->len;

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

static struct tc_action_ops act_gact_ops = {
        .kind           =       "gact",
        .hinfo          =       &gact_hash_info,
        .type           =       TCA_ACT_GACT,
        .capab          =       TCA_CAP_NONE,
        .owner          =       THIS_MODULE,
        .act            =       tcf_gact,
        .dump           =       tcf_gact_dump,
        .cleanup        =       tcf_gact_cleanup,
        .lookup         =       tcf_hash_search,
        .init           =       tcf_gact_init,
        .walk           =       tcf_generic_walker
};

MODULE_AUTHOR("Jamal Hadi Salim(2002-4)");
MODULE_DESCRIPTION("Generic Classifier actions");
MODULE_LICENSE("GPL");

static int __init gact_init_module(void)
{
#ifdef CONFIG_GACT_PROB
        printk("GACT probability on\n");
#else
        printk("GACT probability NOT on\n");
#endif
        return tcf_register_action(&act_gact_ops);
}

static void __exit gact_cleanup_module(void)
{
        tcf_unregister_action(&act_gact_ops);
}

module_init(gact_init_module);
module_exit(gact_cleanup_module);