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