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 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
  61 static 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
  71         if (nla == NULL)
  72                 return -EINVAL;
  73
  74         err = nla_parse_nested(tb, TCA_GACT_MAX, nla, gact_policy);
  75         if (err < 0)
  76                 return err;
  77
  78         if (tb[TCA_GACT_PARMS] == NULL)
  79                 return -EINVAL;
  80         parm = nla_data(tb[TCA_GACT_PARMS]);
  81
  82 #ifndef CONFIG_GACT_PROB
  83         if (tb[TCA_GACT_PROB] != NULL)
  84                 return -EOPNOTSUPP;
  85 #endif
  86
  87         pc = tcf_hash_check(parm->index, a, bind, &gact_hash_info);
  88         if (!pc) {
  89                 pc = tcf_hash_create(parm->index, est, a, sizeof(*gact),
  90                                      bind, &gact_idx_gen, &gact_hash_info);
  91                 if (IS_ERR(pc))
  92                         return PTR_ERR(pc);
  93                 ret = ACT_P_CREATED;
  94         } else {
  95                 if (!ovr) {
  96                         tcf_hash_release(pc, bind, &gact_hash_info);
  97                         return -EEXIST;
  98                 }
  99         }
 100
 101         gact = to_gact(pc);
 102
 103         spin_lock_bh(&gact->tcf_lock);
 104         gact->tcf_action = parm->action;
 105 #ifdef CONFIG_GACT_PROB
 106         if (tb[TCA_GACT_PROB] != NULL) {
 107                 struct tc_gact_p *p_parm = nla_data(tb[TCA_GACT_PROB]);
 108                 gact->tcfg_paction = p_parm->paction;
 109                 gact->tcfg_pval    = p_parm->pval;
 110                 gact->tcfg_ptype   = p_parm->ptype;
 111         }
 112 #endif
 113         spin_unlock_bh(&gact->tcf_lock);
 114         if (ret == ACT_P_CREATED)
 115                 tcf_hash_insert(pc, &gact_hash_info);
 116         return ret;
 117 }
 118
 119 static int tcf_gact_cleanup(struct tc_action *a, int bind)
 120 {
 121         struct tcf_gact *gact = a->priv;
 122
 123         if (gact)
 124                 return tcf_hash_release(&gact->common, bind, &gact_hash_info);
 125         return 0;
 126 }
 127
 128 static int tcf_gact(struct sk_buff *skb, const struct tc_action *a,
 129                     struct tcf_result *res)
 130 {
 131         struct tcf_gact *gact = a->priv;
 132         int action = TC_ACT_SHOT;
 133
 134         spin_lock(&gact->tcf_lock);
 135 #ifdef CONFIG_GACT_PROB
 136         if (gact->tcfg_ptype && gact_rand[gact->tcfg_ptype] != NULL)
 137                 action = gact_rand[gact->tcfg_ptype](gact);
 138         else
 139                 action = gact->tcf_action;
 140 #else
 141         action = gact->tcf_action;
 142 #endif
 143         gact->tcf_bstats.bytes += qdisc_pkt_len(skb);
 144         gact->tcf_bstats.packets++;
 145         if (action == TC_ACT_SHOT)
 146                 gact->tcf_qstats.drops++;
 147         gact->tcf_tm.lastuse = jiffies;
 148         spin_unlock(&gact->tcf_lock);
 149
 150         return action;
 151 }
 152
 153 static int tcf_gact_dump(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 154 {
 155         unsigned char *b = skb_tail_pointer(skb);
 156         struct tcf_gact *gact = a->priv;
 157         struct tc_gact opt = {
 158                 .index   = gact->tcf_index,
 159                 .refcnt  = gact->tcf_refcnt - ref,
 160                 .bindcnt = gact->tcf_bindcnt - bind,
 161                 .action  = gact->tcf_action,
 162         };
 163         struct tcf_t t;
 164
 165         if (nla_put(skb, TCA_GACT_PARMS, sizeof(opt), &opt))
 166                 goto nla_put_failure;
 167 #ifdef CONFIG_GACT_PROB
 168         if (gact->tcfg_ptype) {
 169                 struct tc_gact_p p_opt = {
 170                         .paction = gact->tcfg_paction,
 171                         .pval    = gact->tcfg_pval,
 172                         .ptype   = gact->tcfg_ptype,
 173                 };
 174
 175                 if (nla_put(skb, TCA_GACT_PROB, sizeof(p_opt), &p_opt))
 176                         goto nla_put_failure;
 177         }
 178 #endif
 179         t.install = jiffies_to_clock_t(jiffies - gact->tcf_tm.install);
 180         t.lastuse = jiffies_to_clock_t(jiffies - gact->tcf_tm.lastuse);
 181         t.expires = jiffies_to_clock_t(gact->tcf_tm.expires);
 182         if (nla_put(skb, TCA_GACT_TM, sizeof(t), &t))
 183                 goto nla_put_failure;
 184         return skb->len;
 185
 186 nla_put_failure:
 187         nlmsg_trim(skb, b);
 188         return -1;
 189 }
 190
 191 static struct tc_action_ops act_gact_ops = {
 192         .kind           =       "gact",
 193         .hinfo          =       &gact_hash_info,
 194         .type           =       TCA_ACT_GACT,
 195         .capab          =       TCA_CAP_NONE,
 196         .owner          =       THIS_MODULE,
 197         .act            =       tcf_gact,
 198         .dump           =       tcf_gact_dump,
 199         .cleanup        =       tcf_gact_cleanup,
 200         .lookup         =       tcf_hash_search,
 201         .init           =       tcf_gact_init,
 202         .walk           =       tcf_generic_walker
 203 };
 204
 205 MODULE_AUTHOR("Jamal Hadi Salim(2002-4)");
 206 MODULE_DESCRIPTION("Generic Classifier actions");
 207 MODULE_LICENSE("GPL");
 208
 209 static int __init gact_init_module(void)
 210 {
 211 #ifdef CONFIG_GACT_PROB
 212         pr_info("GACT probability on\n");
 213 #else
 214         pr_info("GACT probability NOT on\n");
 215 #endif
 216         return tcf_register_action(&act_gact_ops);
 217 }
 218
 219 static void __exit gact_cleanup_module(void)
 220 {
 221         tcf_unregister_action(&act_gact_ops);
 222 }
 223
 224 module_init(gact_init_module);
 225 module_exit(gact_cleanup_module);