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/sched.h>
  19 #include <linux/string.h>
  20 #include <linux/mm.h>
  21 #include <linux/socket.h>
  22 #include <linux/sockios.h>
  23 #include <linux/in.h>
  24 #include <linux/errno.h>
  25 #include <linux/interrupt.h>
  26 #include <linux/netdevice.h>
  27 #include <linux/skbuff.h>
  28 #include <linux/rtnetlink.h>
  29 #include <linux/module.h>
  30 #include <linux/init.h>
  31 #include <linux/proc_fs.h>
  32 #include <net/sock.h>
  33 #include <net/pkt_sched.h>
  34 #include <linux/tc_act/tc_gact.h>
  35 #include <net/tc_act/tc_gact.h>
  36
  37 /* use generic hash table */
  38 #define MY_TAB_SIZE     16
  39 #define MY_TAB_MASK     15
  40
  41 static u32 idx_gen;
  42 static struct tcf_gact *tcf_gact_ht[MY_TAB_SIZE];
  43 static DEFINE_RWLOCK(gact_lock);
  44
  45 /* ovewrride the defaults */
  46 #define tcf_st          tcf_gact
  47 #define tc_st           tc_gact
  48 #define tcf_t_lock      gact_lock
  49 #define tcf_ht          tcf_gact_ht
  50
  51 #define CONFIG_NET_ACT_INIT 1
  52 #include <net/pkt_act.h>
  53
  54 #ifdef CONFIG_GACT_PROB
  55 static int gact_net_rand(struct tcf_gact *p)
  56 {
  57         if (net_random()%p->pval)
  58                 return p->action;
  59         return p->paction;
  60 }
  61
  62 static int gact_determ(struct tcf_gact *p)
  63 {
  64         if (p->bstats.packets%p->pval)
  65                 return p->action;
  66         return p->paction;
  67 }
  68
  69 typedef int (*g_rand)(struct tcf_gact *p);
  70 static g_rand gact_rand[MAX_RAND]= { NULL, gact_net_rand, gact_determ };
  71 #endif
  72
  73 static int tcf_gact_init(struct rtattr *rta, struct rtattr *est,
  74                          struct tc_action *a, int ovr, int bind)
  75 {
  76         struct rtattr *tb[TCA_GACT_MAX];
  77         struct tc_gact *parm;
  78         struct tcf_gact *p;
  79         int ret = 0;
  80
  81         if (rta == NULL || rtattr_parse_nested(tb, TCA_GACT_MAX, rta) < 0)
  82                 return -EINVAL;
  83
  84         if (tb[TCA_GACT_PARMS - 1] == NULL ||
  85             RTA_PAYLOAD(tb[TCA_GACT_PARMS - 1]) < sizeof(*parm))
  86                 return -EINVAL;
  87         parm = RTA_DATA(tb[TCA_GACT_PARMS - 1]);
  88
  89         if (tb[TCA_GACT_PROB-1] != NULL)
  90 #ifdef CONFIG_GACT_PROB
  91                 if (RTA_PAYLOAD(tb[TCA_GACT_PROB-1]) < sizeof(struct tc_gact_p))
  92                         return -EINVAL;
  93 #else
  94                 return -EOPNOTSUPP;
  95 #endif
  96
  97         p = tcf_hash_check(parm->index, a, ovr, bind);
  98         if (p == NULL) {
  99                 p = tcf_hash_create(parm->index, est, a, sizeof(*p), ovr, bind);
 100                 if (p == NULL)
 101                         return -ENOMEM;
 102                 ret = ACT_P_CREATED;
 103         } else {
 104                 if (!ovr) {
 105                         tcf_hash_release(p, bind);
 106                         return -EEXIST;
 107                 }
 108         }
 109
 110         spin_lock_bh(&p->lock);
 111         p->action = parm->action;
 112 #ifdef CONFIG_GACT_PROB
 113         if (tb[TCA_GACT_PROB-1] != NULL) {
 114                 struct tc_gact_p *p_parm = RTA_DATA(tb[TCA_GACT_PROB-1]);
 115                 p->paction = p_parm->paction;
 116                 p->pval    = p_parm->pval;
 117                 p->ptype   = p_parm->ptype;
 118         }
 119 #endif
 120         spin_unlock_bh(&p->lock);
 121         if (ret == ACT_P_CREATED)
 122                 tcf_hash_insert(p);
 123         return ret;
 124 }
 125
 126 static int
 127 tcf_gact_cleanup(struct tc_action *a, int bind)
 128 {
 129         struct tcf_gact *p = PRIV(a, gact);
 130
 131         if (p != NULL)
 132                 return tcf_hash_release(p, bind);
 133         return 0;
 134 }
 135
 136 static int
 137 tcf_gact(struct sk_buff *skb, struct tc_action *a, struct tcf_result *res)
 138 {
 139         struct tcf_gact *p = PRIV(a, gact);
 140         int action = TC_ACT_SHOT;
 141
 142         spin_lock(&p->lock);
 143 #ifdef CONFIG_GACT_PROB
 144         if (p->ptype && gact_rand[p->ptype] != NULL)
 145                 action = gact_rand[p->ptype](p);
 146         else
 147                 action = p->action;
 148 #else
 149         action = p->action;
 150 #endif
 151         p->bstats.bytes += skb->len;
 152         p->bstats.packets++;
 153         if (action == TC_ACT_SHOT)
 154                 p->qstats.drops++;
 155         p->tm.lastuse = jiffies;
 156         spin_unlock(&p->lock);
 157
 158         return action;
 159 }
 160
 161 static int
 162 tcf_gact_dump(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 163 {
 164         unsigned char *b = skb->tail;
 165         struct tc_gact opt;
 166         struct tcf_gact *p = PRIV(a, gact);
 167         struct tcf_t t;
 168
 169         opt.index = p->index;
 170         opt.refcnt = p->refcnt - ref;
 171         opt.bindcnt = p->bindcnt - bind;
 172         opt.action = p->action;
 173         RTA_PUT(skb, TCA_GACT_PARMS, sizeof(opt), &opt);
 174 #ifdef CONFIG_GACT_PROB
 175         if (p->ptype) {
 176                 struct tc_gact_p p_opt;
 177                 p_opt.paction = p->paction;
 178                 p_opt.pval = p->pval;
 179                 p_opt.ptype = p->ptype;
 180                 RTA_PUT(skb, TCA_GACT_PROB, sizeof(p_opt), &p_opt);
 181         }
 182 #endif
 183         t.install = jiffies_to_clock_t(jiffies - p->tm.install);
 184         t.lastuse = jiffies_to_clock_t(jiffies - p->tm.lastuse);
 185         t.expires = jiffies_to_clock_t(p->tm.expires);
 186         RTA_PUT(skb, TCA_GACT_TM, sizeof(t), &t);
 187         return skb->len;
 188
 189       rtattr_failure:
 190         skb_trim(skb, b - skb->data);
 191         return -1;
 192 }
 193
 194 static struct tc_action_ops act_gact_ops = {
 195         .kind           =       "gact",
 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         .lookup         =       tcf_hash_search,
 203         .init           =       tcf_gact_init,
 204         .walk           =       tcf_generic_walker
 205 };
 206
 207 MODULE_AUTHOR("Jamal Hadi Salim(2002-4)");
 208 MODULE_DESCRIPTION("Generic Classifier actions");
 209 MODULE_LICENSE("GPL");
 210
 211 static int __init
 212 gact_init_module(void)
 213 {
 214 #ifdef CONFIG_GACT_PROB
 215         printk("GACT probability on\n");
 216 #else
 217         printk("GACT probability NOT on\n");
 218 #endif
 219         return tcf_register_action(&act_gact_ops);
 220 }
 221
 222 static void __exit
 223 gact_cleanup_module(void)
 224 {
 225         tcf_unregister_action(&act_gact_ops);
 226 }
 227
 228 module_init(gact_init_module);
 229 module_exit(gact_cleanup_module);