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