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_hashinfo gact_hash_info;
  28
  29 #ifdef CONFIG_GACT_PROB
  30 static int gact_net_rand(struct tcf_gact *gact)
  31 {
  32         if (!gact->tcfg_pval || prandom_u32() % gact->tcfg_pval)
  33                 return gact->tcf_action;
  34         return gact->tcfg_paction;
  35 }
  36
  37 static int gact_determ(struct tcf_gact *gact)
  38 {
  39         if (!gact->tcfg_pval || gact->tcf_bstats.packets % gact->tcfg_pval)
  40                 return gact->tcf_action;
  41         return gact->tcfg_paction;
  42 }
  43
  44 typedef int (*g_rand)(struct tcf_gact *gact);
  45 static g_rand gact_rand[MAX_RAND] = { NULL, gact_net_rand, gact_determ };
  46 #endif /* CONFIG_GACT_PROB */
  47
  48 static const struct nla_policy gact_policy[TCA_GACT_MAX + 1] = {
  49         [TCA_GACT_PARMS]        = { .len = sizeof(struct tc_gact) },
  50         [TCA_GACT_PROB]         = { .len = sizeof(struct tc_gact_p) },
  51 };
  52
  53 static int tcf_gact_init(struct net *net, struct nlattr *nla,
  54                          struct nlattr *est, struct tc_action *a,
  55                          int ovr, int bind)
  56 {
  57         struct nlattr *tb[TCA_GACT_MAX + 1];
  58         struct tc_gact *parm;
  59         struct tcf_gact *gact;
  60         struct tcf_common *pc;
  61         int ret = 0;
  62         int err;
  63 #ifdef CONFIG_GACT_PROB
  64         struct tc_gact_p *p_parm = NULL;
  65 #endif
  66
  67         if (nla == NULL)
  68                 return -EINVAL;
  69
  70         err = nla_parse_nested(tb, TCA_GACT_MAX, nla, gact_policy);
  71         if (err < 0)
  72                 return err;
  73
  74         if (tb[TCA_GACT_PARMS] == NULL)
  75                 return -EINVAL;
  76         parm = nla_data(tb[TCA_GACT_PARMS]);
  77
  78 #ifndef CONFIG_GACT_PROB
  79         if (tb[TCA_GACT_PROB] != NULL)
  80                 return -EOPNOTSUPP;
  81 #else
  82         if (tb[TCA_GACT_PROB]) {
  83                 p_parm = nla_data(tb[TCA_GACT_PROB]);
  84                 if (p_parm->ptype >= MAX_RAND)
  85                         return -EINVAL;
  86         }
  87 #endif
  88
  89         pc = tcf_hash_check(parm->index, a, bind, &gact_hash_info);
  90         if (!pc) {
  91                 pc = tcf_hash_create(parm->index, est, a, sizeof(*gact),
  92                                      bind, &gact_hash_info);
  93                 if (IS_ERR(pc))
  94                         return PTR_ERR(pc);
  95                 ret = ACT_P_CREATED;
  96         } else {
  97                 if (bind)/* dont override defaults */
  98                         return 0;
  99                 tcf_hash_release(pc, bind, &gact_hash_info);
 100                 if (!ovr)
 101                         return -EEXIST;
 102         }
 103
 104         gact = to_gact(pc);
 105
 106         spin_lock_bh(&gact->tcf_lock);
 107         gact->tcf_action = parm->action;
 108 #ifdef CONFIG_GACT_PROB
 109         if (p_parm) {
 110                 gact->tcfg_paction = p_parm->paction;
 111                 gact->tcfg_pval    = p_parm->pval;
 112                 gact->tcfg_ptype   = p_parm->ptype;
 113         }
 114 #endif
 115         spin_unlock_bh(&gact->tcf_lock);
 116         if (ret == ACT_P_CREATED)
 117                 tcf_hash_insert(pc, &gact_hash_info);
 118         return ret;
 119 }
 120
 121 static int tcf_gact_cleanup(struct tc_action *a, int bind)
 122 {
 123         struct tcf_gact *gact = a->priv;
 124
 125         if (gact)
 126                 return tcf_hash_release(&gact->common, bind, &gact_hash_info);
 127         return 0;
 128 }
 129
 130 static int tcf_gact(struct sk_buff *skb, const struct tc_action *a,
 131                     struct tcf_result *res)
 132 {
 133         struct tcf_gact *gact = a->priv;
 134         int action = TC_ACT_SHOT;
 135
 136         spin_lock(&gact->tcf_lock);
 137 #ifdef CONFIG_GACT_PROB
 138         if (gact->tcfg_ptype)
 139                 action = gact_rand[gact->tcfg_ptype](gact);
 140         else
 141                 action = gact->tcf_action;
 142 #else
 143         action = gact->tcf_action;
 144 #endif
 145         gact->tcf_bstats.bytes += qdisc_pkt_len(skb);
 146         gact->tcf_bstats.packets++;
 147         if (action == TC_ACT_SHOT)
 148                 gact->tcf_qstats.drops++;
 149         gact->tcf_tm.lastuse = jiffies;
 150         spin_unlock(&gact->tcf_lock);
 151
 152         return action;
 153 }
 154
 155 static int tcf_gact_dump(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 156 {
 157         unsigned char *b = skb_tail_pointer(skb);
 158         struct tcf_gact *gact = a->priv;
 159         struct tc_gact opt = {
 160                 .index   = gact->tcf_index,
 161                 .refcnt  = gact->tcf_refcnt - ref,
 162                 .bindcnt = gact->tcf_bindcnt - bind,
 163                 .action  = gact->tcf_action,
 164         };
 165         struct tcf_t t;
 166
 167         if (nla_put(skb, TCA_GACT_PARMS, sizeof(opt), &opt))
 168                 goto nla_put_failure;
 169 #ifdef CONFIG_GACT_PROB
 170         if (gact->tcfg_ptype) {
 171                 struct tc_gact_p p_opt = {
 172                         .paction = gact->tcfg_paction,
 173                         .pval    = gact->tcfg_pval,
 174                         .ptype   = gact->tcfg_ptype,
 175                 };
 176
 177                 if (nla_put(skb, TCA_GACT_PROB, sizeof(p_opt), &p_opt))
 178                         goto nla_put_failure;
 179         }
 180 #endif
 181         t.install = jiffies_to_clock_t(jiffies - gact->tcf_tm.install);
 182         t.lastuse = jiffies_to_clock_t(jiffies - gact->tcf_tm.lastuse);
 183         t.expires = jiffies_to_clock_t(gact->tcf_tm.expires);
 184         if (nla_put(skb, TCA_GACT_TM, sizeof(t), &t))
 185                 goto nla_put_failure;
 186         return skb->len;
 187
 188 nla_put_failure:
 189         nlmsg_trim(skb, b);
 190         return -1;
 191 }
 192
 193 static struct tc_action_ops act_gact_ops = {
 194         .kind           =       "gact",
 195         .hinfo          =       &gact_hash_info,
 196         .type           =       TCA_ACT_GACT,
 197         .capab          =       TCA_CAP_NONE,
 198         .owner          =       THIS_MODULE,
 199         .act            =       tcf_gact,
 200         .dump           =       tcf_gact_dump,
 201         .cleanup        =       tcf_gact_cleanup,
 202         .init           =       tcf_gact_init,
 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         int err = tcf_hashinfo_init(&gact_hash_info, GACT_TAB_MASK);
 212         if (err)
 213                 return err;
 214 #ifdef CONFIG_GACT_PROB
 215         pr_info("GACT probability on\n");
 216 #else
 217         pr_info("GACT probability NOT on\n");
 218 #endif
 219         return tcf_register_action(&act_gact_ops);
 220 }
 221
 222 static void __exit gact_cleanup_module(void)
 223 {
 224         tcf_unregister_action(&act_gact_ops);
 225         tcf_hashinfo_destroy(&gact_hash_info);
 226 }
 227
 228 module_init(gact_init_module);
 229 module_exit(gact_cleanup_module);