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 <asm/uaccess.h>
  14 #include <asm/system.h>
  15 #include <linux/bitops.h>
  16 #include <linux/types.h>
  17 #include <linux/kernel.h>
  18 #include <linux/string.h>
  19 #include <linux/mm.h>
  20 #include <linux/socket.h>
  21 #include <linux/sockios.h>
  22 #include <linux/in.h>
  23 #include <linux/errno.h>
  24 #include <linux/interrupt.h>
  25 #include <linux/netdevice.h>
  26 #include <linux/skbuff.h>
  27 #include <linux/rtnetlink.h>
  28 #include <linux/module.h>
  29 #include <linux/init.h>
  30 #include <linux/proc_fs.h>
  31 #include <net/sock.h>
  32 #include <net/pkt_sched.h>
  33 #include <linux/tc_act/tc_gact.h>
  34 #include <net/tc_act/tc_gact.h>
  35
  36 #define GACT_TAB_MASK   15
  37 static struct tcf_common *tcf_gact_ht[GACT_TAB_MASK + 1];
  38 static u32 gact_idx_gen;
  39 static DEFINE_RWLOCK(gact_lock);
  40
  41 static struct tcf_hashinfo gact_hash_info = {
  42         .htab   =       tcf_gact_ht,
  43         .hmask  =       GACT_TAB_MASK,
  44         .lock   =       &gact_lock,
  45 };
  46
  47 #ifdef CONFIG_GACT_PROB
  48 static int gact_net_rand(struct tcf_gact *gact)
  49 {
  50         if (!gact->tcfg_pval || net_random() % gact->tcfg_pval)
  51                 return gact->tcf_action;
  52         return gact->tcfg_paction;
  53 }
  54
  55 static int gact_determ(struct tcf_gact *gact)
  56 {
  57         if (!gact->tcfg_pval || gact->tcf_bstats.packets % gact->tcfg_pval)
  58                 return gact->tcf_action;
  59         return gact->tcfg_paction;
  60 }
  61
  62 typedef int (*g_rand)(struct tcf_gact *gact);
  63 static g_rand gact_rand[MAX_RAND]= { NULL, gact_net_rand, gact_determ };
  64 #endif /* CONFIG_GACT_PROB */
  65
  66 static int tcf_gact_init(struct rtattr *rta, struct rtattr *est,
  67                          struct tc_action *a, int ovr, int bind)
  68 {
  69         struct rtattr *tb[TCA_GACT_MAX];
  70         struct tc_gact *parm;
  71         struct tcf_gact *gact;
  72         struct tcf_common *pc;
  73         int ret = 0;
  74
  75         if (rta == NULL || rtattr_parse_nested(tb, TCA_GACT_MAX, rta) < 0)
  76                 return -EINVAL;
  77
  78         if (tb[TCA_GACT_PARMS - 1] == NULL ||
  79             RTA_PAYLOAD(tb[TCA_GACT_PARMS - 1]) < sizeof(*parm))
  80                 return -EINVAL;
  81         parm = RTA_DATA(tb[TCA_GACT_PARMS - 1]);
  82
  83         if (tb[TCA_GACT_PROB-1] != NULL)
  84 #ifdef CONFIG_GACT_PROB
  85                 if (RTA_PAYLOAD(tb[TCA_GACT_PROB-1]) < sizeof(struct tc_gact_p))
  86                         return -EINVAL;
  87 #else
  88                 return -EOPNOTSUPP;
  89 #endif
  90
  91         pc = tcf_hash_check(parm->index, a, bind, &gact_hash_info);
  92         if (!pc) {
  93                 pc = tcf_hash_create(parm->index, est, a, sizeof(*gact),
  94                                      bind, &gact_idx_gen, &gact_hash_info);
  95                 if (unlikely(!pc))
  96                         return -ENOMEM;
  97                 ret = ACT_P_CREATED;
  98         } else {
  99                 if (!ovr) {
 100                         tcf_hash_release(pc, bind, &gact_hash_info);
 101                         return -EEXIST;
 102                 }
 103         }
 104
 105         gact = to_gact(pc);
 106
 107         spin_lock_bh(&gact->tcf_lock);
 108         gact->tcf_action = parm->action;
 109 #ifdef CONFIG_GACT_PROB
 110         if (tb[TCA_GACT_PROB-1] != NULL) {
 111                 struct tc_gact_p *p_parm = RTA_DATA(tb[TCA_GACT_PROB-1]);
 112                 gact->tcfg_paction = p_parm->paction;
 113                 gact->tcfg_pval    = p_parm->pval;
 114                 gact->tcfg_ptype   = p_parm->ptype;
 115         }
 116 #endif
 117         spin_unlock_bh(&gact->tcf_lock);
 118         if (ret == ACT_P_CREATED)
 119                 tcf_hash_insert(pc, &gact_hash_info);
 120         return ret;
 121 }
 122
 123 static int tcf_gact_cleanup(struct tc_action *a, int bind)
 124 {
 125         struct tcf_gact *gact = a->priv;
 126
 127         if (gact)
 128                 return tcf_hash_release(&gact->common, bind, &gact_hash_info);
 129         return 0;
 130 }
 131
 132 static int tcf_gact(struct sk_buff *skb, struct tc_action *a, struct tcf_result *res)
 133 {
 134         struct tcf_gact *gact = a->priv;
 135         int action = TC_ACT_SHOT;
 136
 137         spin_lock(&gact->tcf_lock);
 138 #ifdef CONFIG_GACT_PROB
 139         if (gact->tcfg_ptype && gact_rand[gact->tcfg_ptype] != NULL)
 140                 action = gact_rand[gact->tcfg_ptype](gact);
 141         else
 142                 action = gact->tcf_action;
 143 #else
 144         action = gact->tcf_action;
 145 #endif
 146         gact->tcf_bstats.bytes += skb->len;
 147         gact->tcf_bstats.packets++;
 148         if (action == TC_ACT_SHOT)
 149                 gact->tcf_qstats.drops++;
 150         gact->tcf_tm.lastuse = jiffies;
 151         spin_unlock(&gact->tcf_lock);
 152
 153         return action;
 154 }
 155
 156 static int tcf_gact_dump(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 157 {
 158         unsigned char *b = skb->tail;
 159         struct tc_gact opt;
 160         struct tcf_gact *gact = a->priv;
 161         struct tcf_t t;
 162
 163         opt.index = gact->tcf_index;
 164         opt.refcnt = gact->tcf_refcnt - ref;
 165         opt.bindcnt = gact->tcf_bindcnt - bind;
 166         opt.action = gact->tcf_action;
 167         RTA_PUT(skb, TCA_GACT_PARMS, sizeof(opt), &opt);
 168 #ifdef CONFIG_GACT_PROB
 169         if (gact->tcfg_ptype) {
 170                 struct tc_gact_p p_opt;
 171                 p_opt.paction = gact->tcfg_paction;
 172                 p_opt.pval = gact->tcfg_pval;
 173                 p_opt.ptype = gact->tcfg_ptype;
 174                 RTA_PUT(skb, TCA_GACT_PROB, sizeof(p_opt), &p_opt);
 175         }
 176 #endif
 177         t.install = jiffies_to_clock_t(jiffies - gact->tcf_tm.install);
 178         t.lastuse = jiffies_to_clock_t(jiffies - gact->tcf_tm.lastuse);
 179         t.expires = jiffies_to_clock_t(gact->tcf_tm.expires);
 180         RTA_PUT(skb, TCA_GACT_TM, sizeof(t), &t);
 181         return skb->len;
 182
 183 rtattr_failure:
 184         skb_trim(skb, b - skb->data);
 185         return -1;
 186 }
 187
 188 static struct tc_action_ops act_gact_ops = {
 189         .kind           =       "gact",
 190         .hinfo          =       &gact_hash_info,
 191         .type           =       TCA_ACT_GACT,
 192         .capab          =       TCA_CAP_NONE,
 193         .owner          =       THIS_MODULE,
 194         .act            =       tcf_gact,
 195         .dump           =       tcf_gact_dump,
 196         .cleanup        =       tcf_gact_cleanup,
 197         .lookup         =       tcf_hash_search,
 198         .init           =       tcf_gact_init,
 199         .walk           =       tcf_generic_walker
 200 };
 201
 202 MODULE_AUTHOR("Jamal Hadi Salim(2002-4)");
 203 MODULE_DESCRIPTION("Generic Classifier actions");
 204 MODULE_LICENSE("GPL");
 205
 206 static int __init gact_init_module(void)
 207 {
 208 #ifdef CONFIG_GACT_PROB
 209         printk("GACT probability on\n");
 210 #else
 211         printk("GACT probability NOT on\n");
 212 #endif
 213         return tcf_register_action(&act_gact_ops);
 214 }
 215
 216 static void __exit gact_cleanup_module(void)
 217 {
 218         tcf_unregister_action(&act_gact_ops);
 219 }
 220
 221 module_init(gact_init_module);
 222 module_exit(gact_cleanup_module);