net/sched/act_gact.c

   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
  27 static struct tcf_common *tcf_gact_ht[GACT_TAB_MASK + 1];
  28 static u32 gact_idx_gen;
  29 static DEFINE_RWLOCK(gact_lock);
  30
  31 static 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
  38 static 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
  45 static 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
  52 typedef int (*g_rand)(struct tcf_gact *gact);
  53 static g_rand gact_rand[MAX_RAND]= { NULL, gact_net_rand, gact_determ };
  54 #endif /* CONFIG_GACT_PROB */
  55
  56 static int tcf_gact_init(struct nlattr *nla, struct nlattr *est,
  57                          struct tc_action *a, int ovr, int bind)
  58 {
  59         struct nlattr *tb[TCA_GACT_MAX + 1];
  60         struct tc_gact *parm;
  61         struct tcf_gact *gact;
  62         struct tcf_common *pc;
  63         int ret = 0;
  64         int err;
  65
  66         if (nla == NULL)
  67                 return -EINVAL;
  68
  69         err = nla_parse_nested(tb, TCA_GACT_MAX, nla, NULL);
  70         if (err < 0)
  71                 return err;
  72
  73         if (tb[TCA_GACT_PARMS] == NULL ||
  74             nla_len(tb[TCA_GACT_PARMS]) < sizeof(*parm))
  75                 return -EINVAL;
  76         parm = nla_data(tb[TCA_GACT_PARMS]);
  77
  78         if (tb[TCA_GACT_PROB] != NULL)
  79 #ifdef CONFIG_GACT_PROB
  80                 if (nla_len(tb[TCA_GACT_PROB]) < sizeof(struct tc_gact_p))
  81                         return -EINVAL;
  82 #else
  83                 return -EOPNOTSUPP;
  84 #endif
  85
  86         pc = tcf_hash_check(parm->index, a, bind, &gact_hash_info);
  87         if (!pc) {
  88                 pc = tcf_hash_create(parm->index, est, a, sizeof(*gact),
  89                                      bind, &gact_idx_gen, &gact_hash_info);
  90                 if (unlikely(!pc))
  91                         return -ENOMEM;
  92                 ret = ACT_P_CREATED;
  93         } else {
  94                 if (!ovr) {
  95                         tcf_hash_release(pc, bind, &gact_hash_info);
  96                         return -EEXIST;
  97                 }
  98         }
  99
 100         gact = to_gact(pc);
 101
 102         spin_lock_bh(&gact->tcf_lock);
 103         gact->tcf_action = parm->action;
 104 #ifdef CONFIG_GACT_PROB
 105         if (tb[TCA_GACT_PROB] != NULL) {
 106                 struct tc_gact_p *p_parm = nla_data(tb[TCA_GACT_PROB]);
 107                 gact->tcfg_paction = p_parm->paction;
 108                 gact->tcfg_pval    = p_parm->pval;
 109                 gact->tcfg_ptype   = p_parm->ptype;
 110         }
 111 #endif
 112         spin_unlock_bh(&gact->tcf_lock);
 113         if (ret == ACT_P_CREATED)
 114                 tcf_hash_insert(pc, &gact_hash_info);
 115         return ret;
 116 }
 117
 118 static int tcf_gact_cleanup(struct tc_action *a, int bind)
 119 {
 120         struct tcf_gact *gact = a->priv;
 121
 122         if (gact)
 123                 return tcf_hash_release(&gact->common, bind, &gact_hash_info);
 124         return 0;
 125 }
 126
 127 static int tcf_gact(struct sk_buff *skb, struct tc_action *a, struct tcf_result *res)
 128 {
 129         struct tcf_gact *gact = a->priv;
 130         int action = TC_ACT_SHOT;
 131
 132         spin_lock(&gact->tcf_lock);
 133 #ifdef CONFIG_GACT_PROB
 134         if (gact->tcfg_ptype && gact_rand[gact->tcfg_ptype] != NULL)
 135                 action = gact_rand[gact->tcfg_ptype](gact);
 136         else
 137                 action = gact->tcf_action;
 138 #else
 139         action = gact->tcf_action;
 140 #endif
 141         gact->tcf_bstats.bytes += skb->len;
 142         gact->tcf_bstats.packets++;
 143         if (action == TC_ACT_SHOT)
 144                 gact->tcf_qstats.drops++;
 145         gact->tcf_tm.lastuse = jiffies;
 146         spin_unlock(&gact->tcf_lock);
 147
 148         return action;
 149 }
 150
 151 static int tcf_gact_dump(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 152 {
 153         unsigned char *b = skb_tail_pointer(skb);
 154         struct tc_gact opt;
 155         struct tcf_gact *gact = a->priv;
 156         struct tcf_t t;
 157
 158         opt.index = gact->tcf_index;
 159         opt.refcnt = gact->tcf_refcnt - ref;
 160         opt.bindcnt = gact->tcf_bindcnt - bind;
 161         opt.action = gact->tcf_action;
 162         NLA_PUT(skb, TCA_GACT_PARMS, sizeof(opt), &opt);
 163 #ifdef CONFIG_GACT_PROB
 164         if (gact->tcfg_ptype) {
 165                 struct tc_gact_p p_opt;
 166                 p_opt.paction = gact->tcfg_paction;
 167                 p_opt.pval = gact->tcfg_pval;
 168                 p_opt.ptype = gact->tcfg_ptype;
 169                 NLA_PUT(skb, TCA_GACT_PROB, sizeof(p_opt), &p_opt);
 170         }
 171 #endif
 172         t.install = jiffies_to_clock_t(jiffies - gact->tcf_tm.install);
 173         t.lastuse = jiffies_to_clock_t(jiffies - gact->tcf_tm.lastuse);
 174         t.expires = jiffies_to_clock_t(gact->tcf_tm.expires);
 175         NLA_PUT(skb, TCA_GACT_TM, sizeof(t), &t);
 176         return skb->len;
 177
 178 nla_put_failure:
 179         nlmsg_trim(skb, b);
 180         return -1;
 181 }
 182
 183 static struct tc_action_ops act_gact_ops = {
 184         .kind           =       "gact",
 185         .hinfo          =       &gact_hash_info,
 186         .type           =       TCA_ACT_GACT,
 187         .capab          =       TCA_CAP_NONE,
 188         .owner          =       THIS_MODULE,
 189         .act            =       tcf_gact,
 190         .dump           =       tcf_gact_dump,
 191         .cleanup        =       tcf_gact_cleanup,
 192         .lookup         =       tcf_hash_search,
 193         .init           =       tcf_gact_init,
 194         .walk           =       tcf_generic_walker
 195 };
 196
 197 MODULE_AUTHOR("Jamal Hadi Salim(2002-4)");
 198 MODULE_DESCRIPTION("Generic Classifier actions");
 199 MODULE_LICENSE("GPL");
 200
 201 static int __init gact_init_module(void)
 202 {
 203 #ifdef CONFIG_GACT_PROB
 204         printk("GACT probability on\n");
 205 #else
 206         printk("GACT probability NOT on\n");
 207 #endif
 208         return tcf_register_action(&act_gact_ops);
 209 }
 210
 211 static void __exit gact_cleanup_module(void)
 212 {
 213         tcf_unregister_action(&act_gact_ops);
 214 }
 215
 216 module_init(gact_init_module);
 217 module_exit(gact_cleanup_module);