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 net *net, struct nlattr *nla,
  62                          struct nlattr *est, struct tc_action *a,
  63                          int ovr, int bind)
  64 {
  65         struct nlattr *tb[TCA_GACT_MAX + 1];
  66         struct tc_gact *parm;
  67         struct tcf_gact *gact;
  68         struct tcf_common *pc;
  69         int ret = 0;
  70         int err;
  71 #ifdef CONFIG_GACT_PROB
  72         struct tc_gact_p *p_parm = NULL;
  73 #endif
  74
  75         if (nla == NULL)
  76                 return -EINVAL;
  77
  78         err = nla_parse_nested(tb, TCA_GACT_MAX, nla, gact_policy);
  79         if (err < 0)
  80                 return err;
  81
  82         if (tb[TCA_GACT_PARMS] == NULL)
  83                 return -EINVAL;
  84         parm = nla_data(tb[TCA_GACT_PARMS]);
  85
  86 #ifndef CONFIG_GACT_PROB
  87         if (tb[TCA_GACT_PROB] != NULL)
  88                 return -EOPNOTSUPP;
  89 #else
  90         if (tb[TCA_GACT_PROB]) {
  91                 p_parm = nla_data(tb[TCA_GACT_PROB]);
  92                 if (p_parm->ptype >= MAX_RAND)
  93                         return -EINVAL;
  94         }
  95 #endif
  96
  97         pc = tcf_hash_check(parm->index, a, bind, &gact_hash_info);
  98         if (!pc) {
  99                 pc = tcf_hash_create(parm->index, est, a, sizeof(*gact),
 100                                      bind, &gact_idx_gen, &gact_hash_info);
 101                 if (IS_ERR(pc))
 102                         return PTR_ERR(pc);
 103                 ret = ACT_P_CREATED;
 104         } else {
 105                 if (bind)/* dont override defaults */
 106                         return 0;
 107                 tcf_hash_release(pc, bind, &gact_hash_info);
 108                 if (!ovr)
 109                         return -EEXIST;
 110         }
 111
 112         gact = to_gact(pc);
 113
 114         spin_lock_bh(&gact->tcf_lock);
 115         gact->tcf_action = parm->action;
 116 #ifdef CONFIG_GACT_PROB
 117         if (p_parm) {
 118                 gact->tcfg_paction = p_parm->paction;
 119                 gact->tcfg_pval    = p_parm->pval;
 120                 gact->tcfg_ptype   = p_parm->ptype;
 121         }
 122 #endif
 123         spin_unlock_bh(&gact->tcf_lock);
 124         if (ret == ACT_P_CREATED)
 125                 tcf_hash_insert(pc, &gact_hash_info);
 126         return ret;
 127 }
 128
 129 static int tcf_gact_cleanup(struct tc_action *a, int bind)
 130 {
 131         struct tcf_gact *gact = a->priv;
 132
 133         if (gact)
 134                 return tcf_hash_release(&gact->common, bind, &gact_hash_info);
 135         return 0;
 136 }
 137
 138 static int tcf_gact(struct sk_buff *skb, const struct tc_action *a,
 139                     struct tcf_result *res)
 140 {
 141         struct tcf_gact *gact = a->priv;
 142         int action = TC_ACT_SHOT;
 143
 144         spin_lock(&gact->tcf_lock);
 145 #ifdef CONFIG_GACT_PROB
 146         if (gact->tcfg_ptype)
 147                 action = gact_rand[gact->tcfg_ptype](gact);
 148         else
 149                 action = gact->tcf_action;
 150 #else
 151         action = gact->tcf_action;
 152 #endif
 153         gact->tcf_bstats.bytes += qdisc_pkt_len(skb);
 154         gact->tcf_bstats.packets++;
 155         if (action == TC_ACT_SHOT)
 156                 gact->tcf_qstats.drops++;
 157         gact->tcf_tm.lastuse = jiffies;
 158         spin_unlock(&gact->tcf_lock);
 159
 160         return action;
 161 }
 162
 163 static int tcf_gact_dump(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 164 {
 165         unsigned char *b = skb_tail_pointer(skb);
 166         struct tcf_gact *gact = a->priv;
 167         struct tc_gact opt = {
 168                 .index   = gact->tcf_index,
 169                 .refcnt  = gact->tcf_refcnt - ref,
 170                 .bindcnt = gact->tcf_bindcnt - bind,
 171                 .action  = gact->tcf_action,
 172         };
 173         struct tcf_t t;
 174
 175         if (nla_put(skb, TCA_GACT_PARMS, sizeof(opt), &opt))
 176                 goto nla_put_failure;
 177 #ifdef CONFIG_GACT_PROB
 178         if (gact->tcfg_ptype) {
 179                 struct tc_gact_p p_opt = {
 180                         .paction = gact->tcfg_paction,
 181                         .pval    = gact->tcfg_pval,
 182                         .ptype   = gact->tcfg_ptype,
 183                 };
 184
 185                 if (nla_put(skb, TCA_GACT_PROB, sizeof(p_opt), &p_opt))
 186                         goto nla_put_failure;
 187         }
 188 #endif
 189         t.install = jiffies_to_clock_t(jiffies - gact->tcf_tm.install);
 190         t.lastuse = jiffies_to_clock_t(jiffies - gact->tcf_tm.lastuse);
 191         t.expires = jiffies_to_clock_t(gact->tcf_tm.expires);
 192         if (nla_put(skb, TCA_GACT_TM, sizeof(t), &t))
 193                 goto nla_put_failure;
 194         return skb->len;
 195
 196 nla_put_failure:
 197         nlmsg_trim(skb, b);
 198         return -1;
 199 }
 200
 201 static struct tc_action_ops act_gact_ops = {
 202         .kind           =       "gact",
 203         .hinfo          =       &gact_hash_info,
 204         .type           =       TCA_ACT_GACT,
 205         .capab          =       TCA_CAP_NONE,
 206         .owner          =       THIS_MODULE,
 207         .act            =       tcf_gact,
 208         .dump           =       tcf_gact_dump,
 209         .cleanup        =       tcf_gact_cleanup,
 210         .init           =       tcf_gact_init,
 211 };
 212
 213 MODULE_AUTHOR("Jamal Hadi Salim(2002-4)");
 214 MODULE_DESCRIPTION("Generic Classifier actions");
 215 MODULE_LICENSE("GPL");
 216
 217 static int __init gact_init_module(void)
 218 {
 219 #ifdef CONFIG_GACT_PROB
 220         pr_info("GACT probability on\n");
 221 #else
 222         pr_info("GACT probability NOT on\n");
 223 #endif
 224         return tcf_register_action(&act_gact_ops);
 225 }
 226
 227 static void __exit gact_cleanup_module(void)
 228 {
 229         tcf_unregister_action(&act_gact_ops);
 230 }
 231
 232 module_init(gact_init_module);
 233 module_exit(gact_cleanup_module);