kernel/net/sched/act_gact.c

   1 /*
   2  * net/sched/act_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
  27
  28 #ifdef CONFIG_GACT_PROB
  29 static int gact_net_rand(struct tcf_gact *gact)
  30 {
  31         if (!gact->tcfg_pval || prandom_u32() % gact->tcfg_pval)
  32                 return gact->tcf_action;
  33         return gact->tcfg_paction;
  34 }
  35
  36 static int gact_determ(struct tcf_gact *gact)
  37 {
  38         if (!gact->tcfg_pval || gact->tcf_bstats.packets % gact->tcfg_pval)
  39                 return gact->tcf_action;
  40         return gact->tcfg_paction;
  41 }
  42
  43 typedef int (*g_rand)(struct tcf_gact *gact);
  44 static g_rand gact_rand[MAX_RAND] = { NULL, gact_net_rand, gact_determ };
  45 #endif /* CONFIG_GACT_PROB */
  46
  47 static const struct nla_policy gact_policy[TCA_GACT_MAX + 1] = {
  48         [TCA_GACT_PARMS]        = { .len = sizeof(struct tc_gact) },
  49         [TCA_GACT_PROB]         = { .len = sizeof(struct tc_gact_p) },
  50 };
  51
  52 static int tcf_gact_init(struct net *net, struct nlattr *nla,
  53                          struct nlattr *est, struct tc_action *a,
  54                          int ovr, int bind)
  55 {
  56         struct nlattr *tb[TCA_GACT_MAX + 1];
  57         struct tc_gact *parm;
  58         struct tcf_gact *gact;
  59         int ret = 0;
  60         int err;
  61 #ifdef CONFIG_GACT_PROB
  62         struct tc_gact_p *p_parm = NULL;
  63 #endif
  64
  65         if (nla == NULL)
  66                 return -EINVAL;
  67
  68         err = nla_parse_nested(tb, TCA_GACT_MAX, nla, gact_policy);
  69         if (err < 0)
  70                 return err;
  71
  72         if (tb[TCA_GACT_PARMS] == NULL)
  73                 return -EINVAL;
  74         parm = nla_data(tb[TCA_GACT_PARMS]);
  75
  76 #ifndef CONFIG_GACT_PROB
  77         if (tb[TCA_GACT_PROB] != NULL)
  78                 return -EOPNOTSUPP;
  79 #else
  80         if (tb[TCA_GACT_PROB]) {
  81                 p_parm = nla_data(tb[TCA_GACT_PROB]);
  82                 if (p_parm->ptype >= MAX_RAND)
  83                         return -EINVAL;
  84         }
  85 #endif
  86
  87         if (!tcf_hash_check(parm->index, a, bind)) {
  88                 ret = tcf_hash_create(parm->index, est, a, sizeof(*gact), bind);
  89                 if (ret)
  90                         return ret;
  91                 ret = ACT_P_CREATED;
  92         } else {
  93                 if (bind)/* dont override defaults */
  94                         return 0;
  95                 tcf_hash_release(a, bind);
  96                 if (!ovr)
  97                         return -EEXIST;
  98         }
  99
 100         gact = to_gact(a);
 101
 102         spin_lock_bh(&gact->tcf_lock);
 103         gact->tcf_action = parm->action;
 104 #ifdef CONFIG_GACT_PROB
 105         if (p_parm) {
 106                 gact->tcfg_paction = p_parm->paction;
 107                 gact->tcfg_pval    = p_parm->pval;
 108                 gact->tcfg_ptype   = p_parm->ptype;
 109         }
 110 #endif
 111         spin_unlock_bh(&gact->tcf_lock);
 112         if (ret == ACT_P_CREATED)
 113                 tcf_hash_insert(a);
 114         return ret;
 115 }
 116
 117 static int tcf_gact(struct sk_buff *skb, const struct tc_action *a,
 118                     struct tcf_result *res)
 119 {
 120         struct tcf_gact *gact = a->priv;
 121         int action = TC_ACT_SHOT;
 122
 123         spin_lock(&gact->tcf_lock);
 124 #ifdef CONFIG_GACT_PROB
 125         if (gact->tcfg_ptype)
 126                 action = gact_rand[gact->tcfg_ptype](gact);
 127         else
 128                 action = gact->tcf_action;
 129 #else
 130         action = gact->tcf_action;
 131 #endif
 132         gact->tcf_bstats.bytes += qdisc_pkt_len(skb);
 133         gact->tcf_bstats.packets++;
 134         if (action == TC_ACT_SHOT)
 135                 gact->tcf_qstats.drops++;
 136         gact->tcf_tm.lastuse = jiffies;
 137         spin_unlock(&gact->tcf_lock);
 138
 139         return action;
 140 }
 141
 142 static int tcf_gact_dump(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 143 {
 144         unsigned char *b = skb_tail_pointer(skb);
 145         struct tcf_gact *gact = a->priv;
 146         struct tc_gact opt = {
 147                 .index   = gact->tcf_index,
 148                 .refcnt  = gact->tcf_refcnt - ref,
 149                 .bindcnt = gact->tcf_bindcnt - bind,
 150                 .action  = gact->tcf_action,
 151         };
 152         struct tcf_t t;
 153
 154         if (nla_put(skb, TCA_GACT_PARMS, sizeof(opt), &opt))
 155                 goto nla_put_failure;
 156 #ifdef CONFIG_GACT_PROB
 157         if (gact->tcfg_ptype) {
 158                 struct tc_gact_p p_opt = {
 159                         .paction = gact->tcfg_paction,
 160                         .pval    = gact->tcfg_pval,
 161                         .ptype   = gact->tcfg_ptype,
 162                 };
 163
 164                 if (nla_put(skb, TCA_GACT_PROB, sizeof(p_opt), &p_opt))
 165                         goto nla_put_failure;
 166         }
 167 #endif
 168         t.install = jiffies_to_clock_t(jiffies - gact->tcf_tm.install);
 169         t.lastuse = jiffies_to_clock_t(jiffies - gact->tcf_tm.lastuse);
 170         t.expires = jiffies_to_clock_t(gact->tcf_tm.expires);
 171         if (nla_put(skb, TCA_GACT_TM, sizeof(t), &t))
 172                 goto nla_put_failure;
 173         return skb->len;
 174
 175 nla_put_failure:
 176         nlmsg_trim(skb, b);
 177         return -1;
 178 }
 179
 180 static struct tc_action_ops act_gact_ops = {
 181         .kind           =       "gact",
 182         .type           =       TCA_ACT_GACT,
 183         .owner          =       THIS_MODULE,
 184         .act            =       tcf_gact,
 185         .dump           =       tcf_gact_dump,
 186         .init           =       tcf_gact_init,
 187 };
 188
 189 MODULE_AUTHOR("Jamal Hadi Salim(2002-4)");
 190 MODULE_DESCRIPTION("Generic Classifier actions");
 191 MODULE_LICENSE("GPL");
 192
 193 static int __init gact_init_module(void)
 194 {
 195 #ifdef CONFIG_GACT_PROB
 196         pr_info("GACT probability on\n");
 197 #else
 198         pr_info("GACT probability NOT on\n");
 199 #endif
 200         return tcf_register_action(&act_gact_ops, GACT_TAB_MASK);
 201 }
 202
 203 static void __exit gact_cleanup_module(void)
 204 {
 205         tcf_unregister_action(&act_gact_ops);
 206 }
 207
 208 module_init(gact_init_module);
 209 module_exit(gact_cleanup_module);