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