net/sched/act_mirred.c

   1 /*
   2  * net/sched/mirred.c   packet mirroring and redirect 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  * Authors:     Jamal Hadi Salim (2002-4)
  10  *
  11  * TODO: Add ingress support (and socket redirect support)
  12  *
  13  */
  14
  15 #include <asm/uaccess.h>
  16 #include <asm/system.h>
  17 #include <asm/bitops.h>
  18 #include <linux/types.h>
  19 #include <linux/kernel.h>
  20 #include <linux/sched.h>
  21 #include <linux/string.h>
  22 #include <linux/mm.h>
  23 #include <linux/socket.h>
  24 #include <linux/sockios.h>
  25 #include <linux/in.h>
  26 #include <linux/errno.h>
  27 #include <linux/interrupt.h>
  28 #include <linux/netdevice.h>
  29 #include <linux/skbuff.h>
  30 #include <linux/rtnetlink.h>
  31 #include <linux/module.h>
  32 #include <linux/init.h>
  33 #include <linux/proc_fs.h>
  34 #include <net/sock.h>
  35 #include <net/pkt_sched.h>
  36 #include <linux/tc_act/tc_mirred.h>
  37 #include <net/tc_act/tc_mirred.h>
  38
  39 #include <linux/etherdevice.h>
  40 #include <linux/if_arp.h>
  41
  42
  43 /* use generic hash table */
  44 #define MY_TAB_SIZE     8
  45 #define MY_TAB_MASK     (MY_TAB_SIZE - 1)
  46 static u32 idx_gen;
  47 static struct tcf_mirred *tcf_mirred_ht[MY_TAB_SIZE];
  48 static DEFINE_RWLOCK(mirred_lock);
  49
  50 /* ovewrride the defaults */
  51 #define tcf_st          tcf_mirred
  52 #define tc_st           tc_mirred
  53 #define tcf_t_lock      mirred_lock
  54 #define tcf_ht          tcf_mirred_ht
  55
  56 #define CONFIG_NET_ACT_INIT 1
  57 #include <net/pkt_act.h>
  58
  59 static inline int
  60 tcf_mirred_release(struct tcf_mirred *p, int bind)
  61 {
  62         if (p) {
  63                 if (bind)
  64                         p->bindcnt--;
  65                 p->refcnt--;
  66                 if(!p->bindcnt && p->refcnt <= 0) {
  67                         dev_put(p->dev);
  68                         tcf_hash_destroy(p);
  69                         return 1;
  70                 }
  71         }
  72         return 0;
  73 }
  74
  75 static int
  76 tcf_mirred_init(struct rtattr *rta, struct rtattr *est, struct tc_action *a,
  77                 int ovr, int bind)
  78 {
  79         struct rtattr *tb[TCA_MIRRED_MAX];
  80         struct tc_mirred *parm;
  81         struct tcf_mirred *p;
  82         struct net_device *dev = NULL;
  83         int ret = 0;
  84         int ok_push = 0;
  85
  86         if (rta == NULL || rtattr_parse_nested(tb, TCA_MIRRED_MAX, rta) < 0)
  87                 return -EINVAL;
  88
  89         if (tb[TCA_MIRRED_PARMS-1] == NULL ||
  90             RTA_PAYLOAD(tb[TCA_MIRRED_PARMS-1]) < sizeof(*parm))
  91                 return -EINVAL;
  92         parm = RTA_DATA(tb[TCA_MIRRED_PARMS-1]);
  93
  94         if (parm->ifindex) {
  95                 dev = __dev_get_by_index(parm->ifindex);
  96                 if (dev == NULL)
  97                         return -ENODEV;
  98                 switch (dev->type) {
  99                         case ARPHRD_TUNNEL:
 100                         case ARPHRD_TUNNEL6:
 101                         case ARPHRD_SIT:
 102                         case ARPHRD_IPGRE:
 103                         case ARPHRD_VOID:
 104                         case ARPHRD_NONE:
 105                                 ok_push = 0;
 106                                 break;
 107                         default:
 108                                 ok_push = 1;
 109                                 break;
 110                 }
 111         }
 112
 113         p = tcf_hash_check(parm->index, a, ovr, bind);
 114         if (p == NULL) {
 115                 if (!parm->ifindex)
 116                         return -EINVAL;
 117                 p = tcf_hash_create(parm->index, est, a, sizeof(*p), ovr, bind);
 118                 if (p == NULL)
 119                         return -ENOMEM;
 120                 ret = ACT_P_CREATED;
 121         } else {
 122                 if (!ovr) {
 123                         tcf_mirred_release(p, bind);
 124                         return -EEXIST;
 125                 }
 126         }
 127
 128         spin_lock_bh(&p->lock);
 129         p->action = parm->action;
 130         p->eaction = parm->eaction;
 131         if (parm->ifindex) {
 132                 p->ifindex = parm->ifindex;
 133                 if (ret != ACT_P_CREATED)
 134                         dev_put(p->dev);
 135                 p->dev = dev;
 136                 dev_hold(dev);
 137                 p->ok_push = ok_push;
 138         }
 139         spin_unlock_bh(&p->lock);
 140         if (ret == ACT_P_CREATED)
 141                 tcf_hash_insert(p);
 142
 143         DPRINTK("tcf_mirred_init index %d action %d eaction %d device %s "
 144                 "ifindex %d\n", parm->index, parm->action, parm->eaction,
 145                 dev->name, parm->ifindex);
 146         return ret;
 147 }
 148
 149 static int
 150 tcf_mirred_cleanup(struct tc_action *a, int bind)
 151 {
 152         struct tcf_mirred *p = PRIV(a, mirred);
 153
 154         if (p != NULL)
 155                 return tcf_mirred_release(p, bind);
 156         return 0;
 157 }
 158
 159 static int
 160 tcf_mirred(struct sk_buff *skb, struct tc_action *a, struct tcf_result *res)
 161 {
 162         struct tcf_mirred *p = PRIV(a, mirred);
 163         struct net_device *dev;
 164         struct sk_buff *skb2 = NULL;
 165         u32 at = G_TC_AT(skb->tc_verd);
 166
 167         spin_lock(&p->lock);
 168
 169         dev = p->dev;
 170         p->tm.lastuse = jiffies;
 171
 172         if (!(dev->flags&IFF_UP) ) {
 173                 if (net_ratelimit())
 174                         printk("mirred to Houston: device %s is gone!\n",
 175                                dev->name);
 176 bad_mirred:
 177                 if (skb2 != NULL)
 178                         kfree_skb(skb2);
 179                 p->qstats.overlimits++;
 180                 p->bstats.bytes += skb->len;
 181                 p->bstats.packets++;
 182                 spin_unlock(&p->lock);
 183                 /* should we be asking for packet to be dropped?
 184                  * may make sense for redirect case only
 185                 */
 186                 return TC_ACT_SHOT;
 187         }
 188
 189         skb2 = skb_clone(skb, GFP_ATOMIC);
 190         if (skb2 == NULL)
 191                 goto bad_mirred;
 192         if (p->eaction != TCA_EGRESS_MIRROR && p->eaction != TCA_EGRESS_REDIR) {
 193                 if (net_ratelimit())
 194                         printk("tcf_mirred unknown action %d\n", p->eaction);
 195                 goto bad_mirred;
 196         }
 197
 198         p->bstats.bytes += skb2->len;
 199         p->bstats.packets++;
 200         if (!(at & AT_EGRESS))
 201                 if (p->ok_push)
 202                         skb_push(skb2, skb2->dev->hard_header_len);
 203
 204         /* mirror is always swallowed */
 205         if (p->eaction != TCA_EGRESS_MIRROR)
 206                 skb2->tc_verd = SET_TC_FROM(skb2->tc_verd, at);
 207
 208         skb2->dev = dev;
 209         skb2->input_dev = skb->dev;
 210         dev_queue_xmit(skb2);
 211         spin_unlock(&p->lock);
 212         return p->action;
 213 }
 214
 215 static int
 216 tcf_mirred_dump(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 217 {
 218         unsigned char *b = skb->tail;
 219         struct tc_mirred opt;
 220         struct tcf_mirred *p = PRIV(a, mirred);
 221         struct tcf_t t;
 222
 223         opt.index = p->index;
 224         opt.action = p->action;
 225         opt.refcnt = p->refcnt - ref;
 226         opt.bindcnt = p->bindcnt - bind;
 227         opt.eaction = p->eaction;
 228         opt.ifindex = p->ifindex;
 229         DPRINTK("tcf_mirred_dump index %d action %d eaction %d ifindex %d\n",
 230                  p->index, p->action, p->eaction, p->ifindex);
 231         RTA_PUT(skb, TCA_MIRRED_PARMS, sizeof(opt), &opt);
 232         t.install = jiffies_to_clock_t(jiffies - p->tm.install);
 233         t.lastuse = jiffies_to_clock_t(jiffies - p->tm.lastuse);
 234         t.expires = jiffies_to_clock_t(p->tm.expires);
 235         RTA_PUT(skb, TCA_MIRRED_TM, sizeof(t), &t);
 236         return skb->len;
 237
 238       rtattr_failure:
 239         skb_trim(skb, b - skb->data);
 240         return -1;
 241 }
 242
 243 static struct tc_action_ops act_mirred_ops = {
 244         .kind           =       "mirred",
 245         .type           =       TCA_ACT_MIRRED,
 246         .capab          =       TCA_CAP_NONE,
 247         .owner          =       THIS_MODULE,
 248         .act            =       tcf_mirred,
 249         .dump           =       tcf_mirred_dump,
 250         .cleanup        =       tcf_mirred_cleanup,
 251         .lookup         =       tcf_hash_search,
 252         .init           =       tcf_mirred_init,
 253         .walk           =       tcf_generic_walker
 254 };
 255
 256 MODULE_AUTHOR("Jamal Hadi Salim(2002)");
 257 MODULE_DESCRIPTION("Device Mirror/redirect actions");
 258 MODULE_LICENSE("GPL");
 259
 260 static int __init
 261 mirred_init_module(void)
 262 {
 263         printk("Mirror/redirect action on\n");
 264         return tcf_register_action(&act_mirred_ops);
 265 }
 266
 267 static void __exit
 268 mirred_cleanup_module(void)
 269 {
 270         tcf_unregister_action(&act_mirred_ops);
 271 }
 272
 273 module_init(mirred_init_module);
 274 module_exit(mirred_cleanup_module);