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