net/sched/sch_ingress.c

   1 /* net/sched/sch_ingress.c - Ingress qdisc
   2  *              This program is free software; you can redistribute it and/or
   3  *              modify it under the terms of the GNU General Public License
   4  *              as published by the Free Software Foundation; either version
   5  *              2 of the License, or (at your option) any later version.
   6  *
   7  * Authors:     Jamal Hadi Salim 1999
   8  */
   9
  10 #include <linux/module.h>
  11 #include <linux/types.h>
  12 #include <linux/skbuff.h>
  13 #include <linux/netdevice.h>
  14 #include <linux/rtnetlink.h>
  15 #include <linux/netfilter_ipv4.h>
  16 #include <linux/netfilter_ipv6.h>
  17 #include <linux/netfilter.h>
  18 #include <linux/smp.h>
  19 #include <net/pkt_sched.h>
  20 #include <asm/byteorder.h>
  21 #include <asm/uaccess.h>
  22 #include <linux/kmod.h>
  23 #include <linux/stat.h>
  24 #include <linux/interrupt.h>
  25 #include <linux/list.h>
  26
  27
  28 #undef DEBUG_INGRESS
  29
  30 #ifdef DEBUG_INGRESS  /* control */
  31 #define DPRINTK(format,args...) printk(KERN_DEBUG format,##args)
  32 #else
  33 #define DPRINTK(format,args...)
  34 #endif
  35
  36 #if 0  /* data */
  37 #define D2PRINTK(format,args...) printk(KERN_DEBUG format,##args)
  38 #else
  39 #define D2PRINTK(format,args...)
  40 #endif
  41
  42
  43 #define PRIV(sch) qdisc_priv(sch)
  44
  45
  46 /* Thanks to Doron Oz for this hack
  47 */
  48 #ifndef CONFIG_NET_CLS_ACT
  49 #ifdef CONFIG_NETFILTER
  50 static int nf_registered;
  51 #endif
  52 #endif
  53
  54 struct ingress_qdisc_data {
  55         struct Qdisc            *q;
  56         struct tcf_proto        *filter_list;
  57 };
  58
  59
  60 /* ------------------------- Class/flow operations ------------------------- */
  61
  62
  63 static int ingress_graft(struct Qdisc *sch,unsigned long arg,
  64     struct Qdisc *new,struct Qdisc **old)
  65 {
  66 #ifdef DEBUG_INGRESS
  67         struct ingress_qdisc_data *p = PRIV(sch);
  68 #endif
  69
  70         DPRINTK("ingress_graft(sch %p,[qdisc %p],new %p,old %p)\n",
  71                 sch, p, new, old);
  72         DPRINTK("\n ingress_graft: You cannot add qdiscs to classes");
  73         return 1;
  74 }
  75
  76
  77 static struct Qdisc *ingress_leaf(struct Qdisc *sch, unsigned long arg)
  78 {
  79         return NULL;
  80 }
  81
  82
  83 static unsigned long ingress_get(struct Qdisc *sch,u32 classid)
  84 {
  85 #ifdef DEBUG_INGRESS
  86         struct ingress_qdisc_data *p = PRIV(sch);
  87 #endif
  88         DPRINTK("ingress_get(sch %p,[qdisc %p],classid %x)\n", sch, p, classid);
  89         return TC_H_MIN(classid) + 1;
  90 }
  91
  92
  93 static unsigned long ingress_bind_filter(struct Qdisc *sch,
  94     unsigned long parent, u32 classid)
  95 {
  96         return ingress_get(sch, classid);
  97 }
  98
  99
 100 static void ingress_put(struct Qdisc *sch, unsigned long cl)
 101 {
 102 }
 103
 104
 105 static int ingress_change(struct Qdisc *sch, u32 classid, u32 parent,
 106     struct rtattr **tca, unsigned long *arg)
 107 {
 108 #ifdef DEBUG_INGRESS
 109         struct ingress_qdisc_data *p = PRIV(sch);
 110 #endif
 111         DPRINTK("ingress_change(sch %p,[qdisc %p],classid %x,parent %x),"
 112                 "arg 0x%lx\n", sch, p, classid, parent, *arg);
 113         DPRINTK("No effect. sch_ingress doesn't maintain classes at the moment");
 114         return 0;
 115 }
 116
 117
 118
 119 static void ingress_walk(struct Qdisc *sch,struct qdisc_walker *walker)
 120 {
 121 #ifdef DEBUG_INGRESS
 122         struct ingress_qdisc_data *p = PRIV(sch);
 123 #endif
 124         DPRINTK("ingress_walk(sch %p,[qdisc %p],walker %p)\n", sch, p, walker);
 125         DPRINTK("No effect. sch_ingress doesn't maintain classes at the moment");
 126 }
 127
 128
 129 static struct tcf_proto **ingress_find_tcf(struct Qdisc *sch,unsigned long cl)
 130 {
 131         struct ingress_qdisc_data *p = PRIV(sch);
 132
 133         return &p->filter_list;
 134 }
 135
 136
 137 /* --------------------------- Qdisc operations ---------------------------- */
 138
 139
 140 static int ingress_enqueue(struct sk_buff *skb,struct Qdisc *sch)
 141 {
 142         struct ingress_qdisc_data *p = PRIV(sch);
 143         struct tcf_result res;
 144         int result;
 145
 146         D2PRINTK("ingress_enqueue(skb %p,sch %p,[qdisc %p])\n", skb, sch, p);
 147         result = tc_classify(skb, p->filter_list, &res);
 148         D2PRINTK("result %d class 0x%04x\n", result, res.classid);
 149         /*
 150          * Unlike normal "enqueue" functions, ingress_enqueue returns a
 151          * firewall FW_* code.
 152          */
 153 #ifdef CONFIG_NET_CLS_ACT
 154         sch->bstats.packets++;
 155         sch->bstats.bytes += skb->len;
 156         switch (result) {
 157                 case TC_ACT_SHOT:
 158                         result = TC_ACT_SHOT;
 159                         sch->qstats.drops++;
 160                         break;
 161                 case TC_ACT_STOLEN:
 162                 case TC_ACT_QUEUED:
 163                         result = TC_ACT_STOLEN;
 164                         break;
 165                 case TC_ACT_RECLASSIFY:
 166                 case TC_ACT_OK:
 167                 case TC_ACT_UNSPEC:
 168                 default:
 169                         skb->tc_index = TC_H_MIN(res.classid);
 170                         result = TC_ACT_OK;
 171                         break;
 172         };
 173 /* backward compat */
 174 #else
 175 #ifdef  CONFIG_NET_CLS_POLICE
 176         switch (result) {
 177                 case TC_POLICE_SHOT:
 178                 result = NF_DROP;
 179                 sch->qstats.drops++;
 180                 break;
 181                 case TC_POLICE_RECLASSIFY: /* DSCP remarking here ? */
 182                 case TC_POLICE_OK:
 183                 case TC_POLICE_UNSPEC:
 184                 default:
 185                 sch->bstats.packets++;
 186                 sch->bstats.bytes += skb->len;
 187                 result = NF_ACCEPT;
 188                 break;
 189         };
 190
 191 #else
 192         D2PRINTK("Overriding result to ACCEPT\n");
 193         result = NF_ACCEPT;
 194         sch->bstats.packets++;
 195         sch->bstats.bytes += skb->len;
 196 #endif
 197 #endif
 198
 199         return result;
 200 }
 201
 202
 203 static struct sk_buff *ingress_dequeue(struct Qdisc *sch)
 204 {
 205 /*
 206         struct ingress_qdisc_data *p = PRIV(sch);
 207         D2PRINTK("ingress_dequeue(sch %p,[qdisc %p])\n",sch,PRIV(p));
 208 */
 209         return NULL;
 210 }
 211
 212
 213 static int ingress_requeue(struct sk_buff *skb,struct Qdisc *sch)
 214 {
 215 /*
 216         struct ingress_qdisc_data *p = PRIV(sch);
 217         D2PRINTK("ingress_requeue(skb %p,sch %p,[qdisc %p])\n",skb,sch,PRIV(p));
 218 */
 219         return 0;
 220 }
 221
 222 static unsigned int ingress_drop(struct Qdisc *sch)
 223 {
 224 #ifdef DEBUG_INGRESS
 225         struct ingress_qdisc_data *p = PRIV(sch);
 226 #endif
 227         DPRINTK("ingress_drop(sch %p,[qdisc %p])\n", sch, p);
 228         return 0;
 229 }
 230
 231 #ifndef CONFIG_NET_CLS_ACT
 232 #ifdef CONFIG_NETFILTER
 233 static unsigned int
 234 ing_hook(unsigned int hook, struct sk_buff **pskb,
 235                              const struct net_device *indev,
 236                              const struct net_device *outdev,
 237                              int (*okfn)(struct sk_buff *))
 238 {
 239
 240         struct Qdisc *q;
 241         struct sk_buff *skb = *pskb;
 242         struct net_device *dev = skb->dev;
 243         int fwres=NF_ACCEPT;
 244
 245         DPRINTK("ing_hook: skb %s dev=%s len=%u\n",
 246                 skb->sk ? "(owned)" : "(unowned)",
 247                 skb->dev ? (*pskb)->dev->name : "(no dev)",
 248                 skb->len);
 249
 250 /*
 251 revisit later: Use a private since lock dev->queue_lock is also
 252 used on the egress (might slow things for an iota)
 253 */
 254
 255         if (dev->qdisc_ingress) {
 256                 spin_lock(&dev->queue_lock);
 257                 if ((q = dev->qdisc_ingress) != NULL)
 258                         fwres = q->enqueue(skb, q);
 259                 spin_unlock(&dev->queue_lock);
 260         }
 261
 262         return fwres;
 263 }
 264
 265 /* after ipt_filter */
 266 static struct nf_hook_ops ing_ops = {
 267         .hook           = ing_hook,
 268         .owner          = THIS_MODULE,
 269         .pf             = PF_INET,
 270         .hooknum        = NF_IP_PRE_ROUTING,
 271         .priority       = NF_IP_PRI_FILTER + 1,
 272 };
 273
 274 static struct nf_hook_ops ing6_ops = {
 275         .hook           = ing_hook,
 276         .owner          = THIS_MODULE,
 277         .pf             = PF_INET6,
 278         .hooknum        = NF_IP6_PRE_ROUTING,
 279         .priority       = NF_IP6_PRI_FILTER + 1,
 280 };
 281
 282 #endif
 283 #endif
 284
 285 static int ingress_init(struct Qdisc *sch,struct rtattr *opt)
 286 {
 287         struct ingress_qdisc_data *p = PRIV(sch);
 288
 289 /* Make sure either netfilter or preferably CLS_ACT is
 290 * compiled in */
 291 #ifndef CONFIG_NET_CLS_ACT
 292 #ifndef CONFIG_NETFILTER
 293         printk("You MUST compile classifier actions into the kernel\n");
 294         return -EINVAL;
 295 #else
 296         printk("Ingress scheduler: Classifier actions prefered over netfilter\n");
 297 #endif
 298 #endif
 299
 300 #ifndef CONFIG_NET_CLS_ACT
 301 #ifdef CONFIG_NETFILTER
 302         if (!nf_registered) {
 303                 if (nf_register_hook(&ing_ops) < 0) {
 304                         printk("ingress qdisc registration error \n");
 305                         return -EINVAL;
 306                 }
 307                 nf_registered++;
 308
 309                 if (nf_register_hook(&ing6_ops) < 0) {
 310                         printk("IPv6 ingress qdisc registration error, " \
 311                             "disabling IPv6 support.\n");
 312                 } else
 313                         nf_registered++;
 314         }
 315 #endif
 316 #endif
 317
 318         DPRINTK("ingress_init(sch %p,[qdisc %p],opt %p)\n",sch,p,opt);
 319         p->q = &noop_qdisc;
 320         return 0;
 321 }
 322
 323
 324 static void ingress_reset(struct Qdisc *sch)
 325 {
 326         struct ingress_qdisc_data *p = PRIV(sch);
 327
 328         DPRINTK("ingress_reset(sch %p,[qdisc %p])\n", sch, p);
 329
 330 /*
 331 #if 0
 332 */
 333 /* for future use */
 334         qdisc_reset(p->q);
 335 /*
 336 #endif
 337 */
 338 }
 339
 340 /* ------------------------------------------------------------- */
 341
 342
 343 /* ------------------------------------------------------------- */
 344
 345 static void ingress_destroy(struct Qdisc *sch)
 346 {
 347         struct ingress_qdisc_data *p = PRIV(sch);
 348         struct tcf_proto *tp;
 349
 350         DPRINTK("ingress_destroy(sch %p,[qdisc %p])\n", sch, p);
 351         while (p->filter_list) {
 352                 tp = p->filter_list;
 353                 p->filter_list = tp->next;
 354                 tcf_destroy(tp);
 355         }
 356 #if 0
 357 /* for future use */
 358         qdisc_destroy(p->q);
 359 #endif
 360 }
 361
 362
 363 static int ingress_dump(struct Qdisc *sch, struct sk_buff *skb)
 364 {
 365         unsigned char *b = skb->tail;
 366         struct rtattr *rta;
 367
 368         rta = (struct rtattr *) b;
 369         RTA_PUT(skb, TCA_OPTIONS, 0, NULL);
 370         rta->rta_len = skb->tail - b;
 371         return skb->len;
 372
 373 rtattr_failure:
 374         skb_trim(skb, b - skb->data);
 375         return -1;
 376 }
 377
 378 static struct Qdisc_class_ops ingress_class_ops = {
 379         .graft          =       ingress_graft,
 380         .leaf           =       ingress_leaf,
 381         .get            =       ingress_get,
 382         .put            =       ingress_put,
 383         .change         =       ingress_change,
 384         .delete         =       NULL,
 385         .walk           =       ingress_walk,
 386         .tcf_chain      =       ingress_find_tcf,
 387         .bind_tcf       =       ingress_bind_filter,
 388         .unbind_tcf     =       ingress_put,
 389         .dump           =       NULL,
 390 };
 391
 392 static struct Qdisc_ops ingress_qdisc_ops = {
 393         .next           =       NULL,
 394         .cl_ops         =       &ingress_class_ops,
 395         .id             =       "ingress",
 396         .priv_size      =       sizeof(struct ingress_qdisc_data),
 397         .enqueue        =       ingress_enqueue,
 398         .dequeue        =       ingress_dequeue,
 399         .requeue        =       ingress_requeue,
 400         .drop           =       ingress_drop,
 401         .init           =       ingress_init,
 402         .reset          =       ingress_reset,
 403         .destroy        =       ingress_destroy,
 404         .change         =       NULL,
 405         .dump           =       ingress_dump,
 406         .owner          =       THIS_MODULE,
 407 };
 408
 409 static int __init ingress_module_init(void)
 410 {
 411         int ret = 0;
 412
 413         if ((ret = register_qdisc(&ingress_qdisc_ops)) < 0) {
 414                 printk("Unable to register Ingress qdisc\n");
 415                 return ret;
 416         }
 417
 418         return ret;
 419 }
 420 static void __exit ingress_module_exit(void)
 421 {
 422         unregister_qdisc(&ingress_qdisc_ops);
 423 #ifndef CONFIG_NET_CLS_ACT
 424 #ifdef CONFIG_NETFILTER
 425         if (nf_registered) {
 426                 nf_unregister_hook(&ing_ops);
 427                 if (nf_registered > 1)
 428                         nf_unregister_hook(&ing6_ops);
 429         }
 430 #endif
 431 #endif
 432 }
 433 module_init(ingress_module_init)
 434 module_exit(ingress_module_exit)
 435 MODULE_LICENSE("GPL");