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