net/sched/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 rwlock_t mirred_lock = RW_LOCK_UNLOCKED;
  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                 }
  67
  68                 p->refcnt--;
  69                 if(!p->bindcnt && p->refcnt <= 0) {
  70                         dev_put(p->dev);
  71                         tcf_hash_destroy(p);
  72                         return 1;
  73                 }
  74         }
  75
  76         return 0;
  77 }
  78
  79 static int
  80 tcf_mirred_init(struct rtattr *rta, struct rtattr *est, struct tc_action *a,int ovr, int bind)
  81 {
  82         struct rtattr *tb[TCA_MIRRED_MAX];
  83         struct tc_mirred *parm;
  84         struct tcf_mirred *p;
  85         struct net_device *dev = NULL;
  86         int size = sizeof (*p), new = 0;
  87
  88
  89         if (rtattr_parse(tb, TCA_MIRRED_MAX, RTA_DATA(rta), RTA_PAYLOAD(rta)) < 0) {
  90                 DPRINTK("tcf_mirred_init BUG in user space couldnt parse properly\n");
  91                 return -1;
  92         }
  93
  94         if (NULL == a || NULL == tb[TCA_MIRRED_PARMS - 1]) {
  95                 DPRINTK("BUG: tcf_mirred_init called with NULL params\n");
  96                 return -1;
  97         }
  98
  99         parm = RTA_DATA(tb[TCA_MIRRED_PARMS - 1]);
 100
 101         p = tcf_hash_check(parm, a, ovr, bind);
 102         if (NULL == p) { /* new */
 103                 p = tcf_hash_create(parm,est,a,size,ovr,bind);
 104                 new = 1;
 105                 if (NULL == p)
 106                         return -1;
 107         }
 108
 109         if (parm->ifindex) {
 110                 dev = dev_get_by_index(parm->ifindex);
 111                 if (NULL == dev) {
 112                         printk("BUG: tcf_mirred_init called with bad device\n");
 113                         return -1;
 114                 }
 115                 switch (dev->type) {
 116                         case ARPHRD_TUNNEL:
 117                         case ARPHRD_TUNNEL6:
 118                         case ARPHRD_SIT:
 119                         case ARPHRD_IPGRE:
 120                         case ARPHRD_VOID:
 121                         case ARPHRD_NONE:
 122                                 p->ok_push = 0;
 123                                 break;
 124                         default:
 125                                 p->ok_push = 1;
 126                                 break;
 127                 }
 128         } else {
 129                 if (new) {
 130                         kfree(p);
 131                         return -1;
 132                 }
 133         }
 134
 135         if (new || ovr) {
 136                 spin_lock(&p->lock);
 137                 p->action = parm->action;
 138                 p->eaction = parm->eaction;
 139                 if (parm->ifindex) {
 140                         p->ifindex = parm->ifindex;
 141                         if (ovr)
 142                                 dev_put(p->dev);
 143                         p->dev = dev;
 144                 }
 145                 spin_unlock(&p->lock);
 146         }
 147
 148
 149         DPRINTK(" tcf_mirred_init index %d action %d eaction %d device %s ifndex %d\n",parm->index,parm->action,parm->eaction,dev->name,parm->ifindex);
 150         return new;
 151
 152 }
 153
 154 static int
 155 tcf_mirred_cleanup(struct tc_action *a, int bind)
 156 {
 157         struct tcf_mirred *p;
 158         p = PRIV(a,mirred);
 159         if (NULL != p)
 160                 return tcf_mirred_release(p, bind);
 161         return 0;
 162 }
 163
 164 static int
 165 tcf_mirred(struct sk_buff **pskb, struct tc_action *a)
 166 {
 167         struct tcf_mirred *p;
 168         struct net_device *dev;
 169         struct sk_buff *skb2 = NULL;
 170         struct sk_buff *skb = *pskb;
 171         __u32 at = G_TC_AT(skb->tc_verd);
 172
 173         if (NULL == a) {
 174                 if (net_ratelimit())
 175                         printk("BUG: tcf_mirred called with NULL action!\n");
 176                 return -1;
 177         }
 178
 179         p = PRIV(a,mirred);
 180
 181         if (NULL == p) {
 182                 if (net_ratelimit())
 183                         printk("BUG: tcf_mirred called with NULL params\n");
 184                 return -1;
 185         }
 186
 187         spin_lock(&p->lock);
 188
 189         dev = p->dev;
 190         p->tm.lastuse = jiffies;
 191
 192         if (NULL == dev || !(dev->flags&IFF_UP) ) {
 193                 if (net_ratelimit())
 194                         printk("mirred to Houston: device %s is gone!\n",
 195                                         dev?dev->name:"");
 196 bad_mirred:
 197                 if (NULL != skb2)
 198                         kfree_skb(skb2);
 199                 p->qstats.overlimits++;
 200                 p->bstats.bytes += skb->len;
 201                 p->bstats.packets++;
 202                 spin_unlock(&p->lock);
 203                 /* should we be asking for packet to be dropped?
 204                  * may make sense for redirect case only
 205                 */
 206                 return TC_ACT_SHOT;
 207         }
 208
 209         skb2 = skb_clone(skb, GFP_ATOMIC);
 210         if (skb2 == NULL) {
 211                 goto bad_mirred;
 212         }
 213         if (TCA_EGRESS_MIRROR != p->eaction &&
 214                 TCA_EGRESS_REDIR != p->eaction) {
 215                 if (net_ratelimit())
 216                         printk("tcf_mirred unknown action %d\n",p->eaction);
 217                 goto bad_mirred;
 218         }
 219
 220         p->bstats.bytes += skb2->len;
 221         p->bstats.packets++;
 222         if ( !(at & AT_EGRESS)) {
 223                 if (p->ok_push) {
 224                         skb_push(skb2, skb2->dev->hard_header_len);
 225                 }
 226         }
 227
 228         /* mirror is always swallowed */
 229         if (TCA_EGRESS_MIRROR != p->eaction)
 230                 skb2->tc_verd = SET_TC_FROM(skb2->tc_verd,at);
 231
 232         skb2->dev = dev;
 233         skb2->input_dev = skb->dev;
 234         dev_queue_xmit(skb2);
 235         spin_unlock(&p->lock);
 236         return p->action;
 237 }
 238
 239 static int
 240 tcf_mirred_dump(struct sk_buff *skb, struct tc_action *a,int bind, int ref)
 241 {
 242         unsigned char *b = skb->tail;
 243         struct tc_mirred opt;
 244         struct tcf_mirred *p;
 245         struct tcf_t t;
 246
 247         p = PRIV(a,mirred);
 248         if (NULL == p) {
 249                 printk("BUG: tcf_mirred_dump called with NULL params\n");
 250                 goto rtattr_failure;
 251         }
 252
 253         opt.index = p->index;
 254         opt.action = p->action;
 255         opt.refcnt = p->refcnt - ref;
 256         opt.bindcnt = p->bindcnt - bind;
 257         opt.eaction = p->eaction;
 258         opt.ifindex = p->ifindex;
 259         DPRINTK(" tcf_mirred_dump index %d action %d eaction %d ifndex %d\n",p->index,p->action,p->eaction,p->ifindex);
 260         RTA_PUT(skb, TCA_MIRRED_PARMS, sizeof (opt), &opt);
 261         t.install = jiffies_to_clock_t(jiffies - p->tm.install);
 262         t.lastuse = jiffies_to_clock_t(jiffies - p->tm.lastuse);
 263         t.expires = jiffies_to_clock_t(p->tm.expires);
 264         RTA_PUT(skb, TCA_MIRRED_TM, sizeof (t), &t);
 265         return skb->len;
 266
 267       rtattr_failure:
 268         skb_trim(skb, b - skb->data);
 269         return -1;
 270 }
 271
 272 static struct tc_action_ops act_mirred_ops = {
 273         .next           =       NULL,
 274         .kind           =       "mirred",
 275         .type           =       TCA_ACT_MIRRED,
 276         .capab          =       TCA_CAP_NONE,
 277         .owner          =       THIS_MODULE,
 278         .act            =       tcf_mirred,
 279         .dump           =       tcf_mirred_dump,
 280         .cleanup        =       tcf_mirred_cleanup,
 281         .lookup         =       tcf_hash_search,
 282         .init           =       tcf_mirred_init,
 283         .walk           =       tcf_generic_walker
 284 };
 285
 286 MODULE_AUTHOR("Jamal Hadi Salim(2002)");
 287 MODULE_DESCRIPTION("Device Mirror/redirect actions");
 288 MODULE_LICENSE("GPL");
 289
 290
 291 static int __init
 292 mirred_init_module(void)
 293 {
 294         printk("Mirror/redirect action on\n");
 295         return tcf_register_action(&act_mirred_ops);
 296 }
 297
 298 static void __exit
 299 mirred_cleanup_module(void)
 300 {
 301         tcf_unregister_action(&act_mirred_ops);
 302 }
 303
 304 module_init(mirred_init_module);
 305 module_exit(mirred_cleanup_module);
 306