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