linux/net/sched/act_gact.c
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   1/*
   2 * net/sched/gact.c     Generic actions
   3 *
   4 *              This program is free software; you can redistribute it and/or
   5 *              modify it under the terms of the GNU General Public License
   6 *              as published by the Free Software Foundation; either version
   7 *              2 of the License, or (at your option) any later version.
   8 *
   9 * copyright    Jamal Hadi Salim (2002-4)
  10 *
  11 */
  12
  13#include <linux/types.h>
  14#include <linux/kernel.h>
  15#include <linux/string.h>
  16#include <linux/errno.h>
  17#include <linux/skbuff.h>
  18#include <linux/rtnetlink.h>
  19#include <linux/module.h>
  20#include <linux/init.h>
  21#include <net/netlink.h>
  22#include <net/pkt_sched.h>
  23#include <linux/tc_act/tc_gact.h>
  24#include <net/tc_act/tc_gact.h>
  25
  26#define GACT_TAB_MASK   15
  27static struct tcf_common *tcf_gact_ht[GACT_TAB_MASK + 1];
  28static u32 gact_idx_gen;
  29static DEFINE_RWLOCK(gact_lock);
  30
  31static struct tcf_hashinfo gact_hash_info = {
  32        .htab   =       tcf_gact_ht,
  33        .hmask  =       GACT_TAB_MASK,
  34        .lock   =       &gact_lock,
  35};
  36
  37#ifdef CONFIG_GACT_PROB
  38static int gact_net_rand(struct tcf_gact *gact)
  39{
  40        if (!gact->tcfg_pval || net_random() % gact->tcfg_pval)
  41                return gact->tcf_action;
  42        return gact->tcfg_paction;
  43}
  44
  45static int gact_determ(struct tcf_gact *gact)
  46{
  47        if (!gact->tcfg_pval || gact->tcf_bstats.packets % gact->tcfg_pval)
  48                return gact->tcf_action;
  49        return gact->tcfg_paction;
  50}
  51
  52typedef int (*g_rand)(struct tcf_gact *gact);
  53static g_rand gact_rand[MAX_RAND] = { NULL, gact_net_rand, gact_determ };
  54#endif /* CONFIG_GACT_PROB */
  55
  56static const struct nla_policy gact_policy[TCA_GACT_MAX + 1] = {
  57        [TCA_GACT_PARMS]        = { .len = sizeof(struct tc_gact) },
  58        [TCA_GACT_PROB]         = { .len = sizeof(struct tc_gact_p) },
  59};
  60
  61static int tcf_gact_init(struct nlattr *nla, struct nlattr *est,
  62                         struct tc_action *a, int ovr, int bind)
  63{
  64        struct nlattr *tb[TCA_GACT_MAX + 1];
  65        struct tc_gact *parm;
  66        struct tcf_gact *gact;
  67        struct tcf_common *pc;
  68        int ret = 0;
  69        int err;
  70#ifdef CONFIG_GACT_PROB
  71        struct tc_gact_p *p_parm = NULL;
  72#endif
  73
  74        if (nla == NULL)
  75                return -EINVAL;
  76
  77        err = nla_parse_nested(tb, TCA_GACT_MAX, nla, gact_policy);
  78        if (err < 0)
  79                return err;
  80
  81        if (tb[TCA_GACT_PARMS] == NULL)
  82                return -EINVAL;
  83        parm = nla_data(tb[TCA_GACT_PARMS]);
  84
  85#ifndef CONFIG_GACT_PROB
  86        if (tb[TCA_GACT_PROB] != NULL)
  87                return -EOPNOTSUPP;
  88#else
  89        if (tb[TCA_GACT_PROB]) {
  90                p_parm = nla_data(tb[TCA_GACT_PROB]);
  91                if (p_parm->ptype >= MAX_RAND)
  92                        return -EINVAL;
  93        }
  94#endif
  95
  96        pc = tcf_hash_check(parm->index, a, bind, &gact_hash_info);
  97        if (!pc) {
  98                pc = tcf_hash_create(parm->index, est, a, sizeof(*gact),
  99                                     bind, &gact_idx_gen, &gact_hash_info);
 100                if (IS_ERR(pc))
 101                        return PTR_ERR(pc);
 102                ret = ACT_P_CREATED;
 103        } else {
 104                if (!ovr) {
 105                        tcf_hash_release(pc, bind, &gact_hash_info);
 106                        return -EEXIST;
 107                }
 108        }
 109
 110        gact = to_gact(pc);
 111
 112        spin_lock_bh(&gact->tcf_lock);
 113        gact->tcf_action = parm->action;
 114#ifdef CONFIG_GACT_PROB
 115        if (p_parm) {
 116                gact->tcfg_paction = p_parm->paction;
 117                gact->tcfg_pval    = p_parm->pval;
 118                gact->tcfg_ptype   = p_parm->ptype;
 119        }
 120#endif
 121        spin_unlock_bh(&gact->tcf_lock);
 122        if (ret == ACT_P_CREATED)
 123                tcf_hash_insert(pc, &gact_hash_info);
 124        return ret;
 125}
 126
 127static int tcf_gact_cleanup(struct tc_action *a, int bind)
 128{
 129        struct tcf_gact *gact = a->priv;
 130
 131        if (gact)
 132                return tcf_hash_release(&gact->common, bind, &gact_hash_info);
 133        return 0;
 134}
 135
 136static int tcf_gact(struct sk_buff *skb, const struct tc_action *a,
 137                    struct tcf_result *res)
 138{
 139        struct tcf_gact *gact = a->priv;
 140        int action = TC_ACT_SHOT;
 141
 142        spin_lock(&gact->tcf_lock);
 143#ifdef CONFIG_GACT_PROB
 144        if (gact->tcfg_ptype)
 145                action = gact_rand[gact->tcfg_ptype](gact);
 146        else
 147                action = gact->tcf_action;
 148#else
 149        action = gact->tcf_action;
 150#endif
 151        gact->tcf_bstats.bytes += qdisc_pkt_len(skb);
 152        gact->tcf_bstats.packets++;
 153        if (action == TC_ACT_SHOT)
 154                gact->tcf_qstats.drops++;
 155        gact->tcf_tm.lastuse = jiffies;
 156        spin_unlock(&gact->tcf_lock);
 157
 158        return action;
 159}
 160
 161static int tcf_gact_dump(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 162{
 163        unsigned char *b = skb_tail_pointer(skb);
 164        struct tcf_gact *gact = a->priv;
 165        struct tc_gact opt = {
 166                .index   = gact->tcf_index,
 167                .refcnt  = gact->tcf_refcnt - ref,
 168                .bindcnt = gact->tcf_bindcnt - bind,
 169                .action  = gact->tcf_action,
 170        };
 171        struct tcf_t t;
 172
 173        if (nla_put(skb, TCA_GACT_PARMS, sizeof(opt), &opt))
 174                goto nla_put_failure;
 175#ifdef CONFIG_GACT_PROB
 176        if (gact->tcfg_ptype) {
 177                struct tc_gact_p p_opt = {
 178                        .paction = gact->tcfg_paction,
 179                        .pval    = gact->tcfg_pval,
 180                        .ptype   = gact->tcfg_ptype,
 181                };
 182
 183                if (nla_put(skb, TCA_GACT_PROB, sizeof(p_opt), &p_opt))
 184                        goto nla_put_failure;
 185        }
 186#endif
 187        t.install = jiffies_to_clock_t(jiffies - gact->tcf_tm.install);
 188        t.lastuse = jiffies_to_clock_t(jiffies - gact->tcf_tm.lastuse);
 189        t.expires = jiffies_to_clock_t(gact->tcf_tm.expires);
 190        if (nla_put(skb, TCA_GACT_TM, sizeof(t), &t))
 191                goto nla_put_failure;
 192        return skb->len;
 193
 194nla_put_failure:
 195        nlmsg_trim(skb, b);
 196        return -1;
 197}
 198
 199static struct tc_action_ops act_gact_ops = {
 200        .kind           =       "gact",
 201        .hinfo          =       &gact_hash_info,
 202        .type           =       TCA_ACT_GACT,
 203        .capab          =       TCA_CAP_NONE,
 204        .owner          =       THIS_MODULE,
 205        .act            =       tcf_gact,
 206        .dump           =       tcf_gact_dump,
 207        .cleanup        =       tcf_gact_cleanup,
 208        .lookup         =       tcf_hash_search,
 209        .init           =       tcf_gact_init,
 210        .walk           =       tcf_generic_walker
 211};
 212
 213MODULE_AUTHOR("Jamal Hadi Salim(2002-4)");
 214MODULE_DESCRIPTION("Generic Classifier actions");
 215MODULE_LICENSE("GPL");
 216
 217static int __init gact_init_module(void)
 218{
 219#ifdef CONFIG_GACT_PROB
 220        pr_info("GACT probability on\n");
 221#else
 222        pr_info("GACT probability NOT on\n");
 223#endif
 224        return tcf_register_action(&act_gact_ops);
 225}
 226
 227static void __exit gact_cleanup_module(void)
 228{
 229        tcf_unregister_action(&act_gact_ops);
 230}
 231
 232module_init(gact_init_module);
 233module_exit(gact_cleanup_module);
 234
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