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/config.h>
  11 #include <linux/module.h>
  12 #include <linux/types.h>
  13 #include <linux/skbuff.h>
  14 #include <linux/netdevice.h>
  15 #include <linux/rtnetlink.h>
  16 #include <linux/netfilter_ipv4.h>
  17 #include <linux/netfilter.h>
  18 #include <net/pkt_sched.h>
  19 #include <asm/byteorder.h>
  20 #include <asm/uaccess.h>
  21 #include <asm/smp.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) ((struct ingress_qdisc_data *) (sch)->data)
  44
  45
  46
  47 struct ingress_qdisc_data {
  48         struct Qdisc            *q;
  49         struct tcf_proto        *filter_list;
  50 };
  51
  52
  53 /* ------------------------- Class/flow operations ------------------------- */
  54
  55
  56 static int ingress_graft(struct Qdisc *sch,unsigned long arg,
  57     struct Qdisc *new,struct Qdisc **old)
  58 {
  59 #ifdef DEBUG_INGRESS
  60         struct ingress_qdisc_data *p = PRIV(sch);
  61 #endif
  62
  63         DPRINTK("ingress_graft(sch %p,[qdisc %p],new %p,old %p)\n",
  64                 sch, p, new, old);
  65         DPRINTK("\n ingress_graft: You cannot add qdiscs to classes");
  66         return 1;
  67 }
  68
  69
  70 static struct Qdisc *ingress_leaf(struct Qdisc *sch, unsigned long arg)
  71 {
  72         return NULL;
  73 }
  74
  75
  76 static unsigned long ingress_get(struct Qdisc *sch,u32 classid)
  77 {
  78 #ifdef DEBUG_INGRESS
  79         struct ingress_qdisc_data *p = PRIV(sch);
  80 #endif
  81         DPRINTK("ingress_get(sch %p,[qdisc %p],classid %x)\n", sch, p, classid);
  82         return TC_H_MIN(classid) + 1;
  83 }
  84
  85
  86 static unsigned long ingress_bind_filter(struct Qdisc *sch,
  87     unsigned long parent, u32 classid)
  88 {
  89         return ingress_get(sch, classid);
  90 }
  91
  92
  93 static void ingress_put(struct Qdisc *sch, unsigned long cl)
  94 {
  95 }
  96
  97
  98 static int ingress_change(struct Qdisc *sch, u32 classid, u32 parent,
  99     struct rtattr **tca, unsigned long *arg)
 100 {
 101 #ifdef DEBUG_INGRESS
 102         struct ingress_qdisc_data *p = PRIV(sch);
 103 #endif
 104         DPRINTK("ingress_change(sch %p,[qdisc %p],classid %x,parent %x),"
 105                 "arg 0x%lx\n", sch, p, classid, parent, *arg);
 106         DPRINTK("No effect. sch_ingress doesnt maintain classes at the moment");
 107         return 0;
 108 }
 109
 110
 111
 112 static void ingress_walk(struct Qdisc *sch,struct qdisc_walker *walker)
 113 {
 114 #ifdef DEBUG_INGRESS
 115         struct ingress_qdisc_data *p = PRIV(sch);
 116 #endif
 117         DPRINTK("ingress_walk(sch %p,[qdisc %p],walker %p)\n", sch, p, walker);
 118         DPRINTK("No effect. sch_ingress doesnt maintain classes at the moment");
 119 }
 120
 121
 122 static struct tcf_proto **ingress_find_tcf(struct Qdisc *sch,unsigned long cl)
 123 {
 124         struct ingress_qdisc_data *p = PRIV(sch);
 125
 126         return &p->filter_list;
 127 }
 128
 129
 130 /* --------------------------- Qdisc operations ---------------------------- */
 131
 132
 133 static int ingress_enqueue(struct sk_buff *skb,struct Qdisc *sch)
 134 {
 135         struct ingress_qdisc_data *p = PRIV(sch);
 136         struct tcf_result res;
 137         int result;
 138
 139         D2PRINTK("ingress_enqueue(skb %p,sch %p,[qdisc %p])\n", skb, sch, p);
 140         result = tc_classify(skb, p->filter_list, &res);
 141         D2PRINTK("result %d class 0x%04x\n", result, res.classid);
 142         /*
 143          * Unlike normal "enqueue" functions, ingress_enqueue returns a
 144          * firewall FW_* code.
 145          */
 146         switch (result) {
 147 #ifdef CONFIG_NET_CLS_POLICE
 148                 case TC_POLICE_SHOT:
 149                         result = NF_DROP;
 150                         break;
 151                 case TC_POLICE_RECLASSIFY: /* DSCP remarking here ? */
 152                 case TC_POLICE_OK:
 153                 case TC_POLICE_UNSPEC:
 154                 default:
 155                         result = NF_ACCEPT;
 156                         break;
 157 #endif
 158         };
 159
 160 #ifdef CONFIG_NET_CLS_TCINDEX
 161          skb->tc_index = TC_H_MIN(res.classid);
 162 #endif
 163         return result;
 164 }
 165
 166
 167 static struct sk_buff *ingress_dequeue(struct Qdisc *sch)
 168 {
 169 /*
 170         struct ingress_qdisc_data *p = PRIV(sch);
 171         D2PRINTK("ingress_dequeue(sch %p,[qdisc %p])\n",sch,PRIV(p));
 172 */
 173         return NULL;
 174 }
 175
 176
 177 static int ingress_requeue(struct sk_buff *skb,struct Qdisc *sch)
 178 {
 179 /*
 180         struct ingress_qdisc_data *p = PRIV(sch);
 181         D2PRINTK("ingress_requeue(skb %p,sch %p,[qdisc %p])\n",skb,sch,PRIV(p));
 182 */
 183         return 0;
 184 }
 185
 186 static int ingress_drop(struct Qdisc *sch)
 187 {
 188 #ifdef DEBUG_INGRESS
 189         struct ingress_qdisc_data *p = PRIV(sch);
 190 #endif
 191         DPRINTK("ingress_drop(sch %p,[qdisc %p])\n", sch, p);
 192         return 0;
 193 }
 194
 195 static unsigned int
 196 ing_hook(unsigned int hook, struct sk_buff **pskb,
 197                              const struct net_device *indev,
 198                              const struct net_device *outdev,
 199                              int (*okfn)(struct sk_buff *))
 200 {
 201
 202         struct Qdisc *q;
 203         struct sk_buff *skb = *pskb;
 204         struct net_device *dev = skb->dev;
 205         int fwres=NF_ACCEPT;
 206
 207         DPRINTK("ing_hook: skb %s dev=%s len=%u\n",
 208                 skb->sk ? "(owned)" : "(unowned)",
 209                 skb->dev ? (*pskb)->dev->name : "(no dev)",
 210                 skb->len);
 211
 212 /*
 213 revisit later: Use a private since lock dev->queue_lock is also
 214 used on the egress (might slow things for an iota)
 215 */
 216
 217         if (dev->qdisc_ingress) {
 218                 spin_lock(&dev->queue_lock);
 219                 if ((q = dev->qdisc_ingress) != NULL)
 220                         fwres = q->enqueue(skb, q);
 221                 spin_unlock(&dev->queue_lock);
 222         }
 223
 224         return fwres;
 225 }
 226
 227 /* after ipt_filter */
 228 static struct nf_hook_ops ing_ops =
 229 {
 230         { NULL, NULL},
 231         ing_hook,
 232         PF_INET,
 233         NF_IP_PRE_ROUTING,
 234         NF_IP_PRI_FILTER + 1
 235 };
 236
 237 int ingress_init(struct Qdisc *sch,struct rtattr *opt)
 238 {
 239         struct ingress_qdisc_data *p = PRIV(sch);
 240
 241         DPRINTK("ingress_init(sch %p,[qdisc %p],opt %p)\n",sch,p,opt);
 242         memset(p, 0, sizeof(*p));
 243         p->filter_list = NULL;
 244         p->q = &noop_qdisc;
 245 #ifndef MODULE
 246         if (nf_register_hook(&ing_ops) < 0) {
 247                 printk("Unable to register ingress \n");
 248                 goto error;
 249         }
 250 #endif
 251         DPRINTK("ingress_init: qdisc %p\n", sch);
 252         MOD_INC_USE_COUNT;
 253         return 0;
 254 #ifndef MODULE
 255 error:
 256 #endif
 257         return -EINVAL;
 258 }
 259
 260
 261 static void ingress_reset(struct Qdisc *sch)
 262 {
 263         struct ingress_qdisc_data *p = PRIV(sch);
 264
 265         DPRINTK("ingress_reset(sch %p,[qdisc %p])\n", sch, p);
 266
 267 /*
 268 #if 0
 269 */
 270 /* for future use */
 271         qdisc_reset(p->q);
 272 /*
 273 #endif
 274 */
 275 }
 276
 277 /* ------------------------------------------------------------- */
 278
 279
 280 /* ------------------------------------------------------------- */
 281
 282 static void ingress_destroy(struct Qdisc *sch)
 283 {
 284         struct ingress_qdisc_data *p = PRIV(sch);
 285         struct tcf_proto *tp;
 286
 287         DPRINTK("ingress_destroy(sch %p,[qdisc %p])\n", sch, p);
 288         while (p->filter_list) {
 289                 tp = p->filter_list;
 290                 p->filter_list = tp->next;
 291                 tp->ops->destroy(tp);
 292         }
 293         memset(p, 0, sizeof(*p));
 294         p->filter_list = NULL;
 295
 296 #if 0
 297 /* for future use */
 298         qdisc_destroy(p->q);
 299 #endif
 300
 301 #ifndef MODULE
 302         nf_unregister_hook(&ing_ops);
 303 #endif
 304
 305         MOD_DEC_USE_COUNT;
 306 }
 307
 308
 309 #ifdef CONFIG_RTNETLINK
 310
 311
 312 static int ingress_dump(struct Qdisc *sch, struct sk_buff *skb)
 313 {
 314         unsigned char *b = skb->tail;
 315         struct rtattr *rta;
 316
 317         rta = (struct rtattr *) b;
 318         RTA_PUT(skb, TCA_OPTIONS, 0, NULL);
 319         rta->rta_len = skb->tail - b;
 320         return skb->len;
 321
 322 rtattr_failure:
 323         skb_trim(skb, b - skb->data);
 324         return -1;
 325 }
 326
 327 #endif
 328
 329
 330 static struct Qdisc_class_ops ingress_class_ops =
 331 {
 332         ingress_graft,                  /* graft */
 333         ingress_leaf,                   /* leaf */
 334         ingress_get,                    /* get */
 335         ingress_put,                    /* put */
 336         ingress_change,                 /* change */
 337         NULL,                           /* delete */
 338         ingress_walk,                           /* walk */
 339
 340         ingress_find_tcf,               /* tcf_chain */
 341         ingress_bind_filter,            /* bind_tcf */
 342         ingress_put,                    /* unbind_tcf */
 343
 344 #ifdef CONFIG_RTNETLINK
 345         NULL,           /* dump */
 346 #endif
 347 };
 348
 349 struct Qdisc_ops ingress_qdisc_ops =
 350 {
 351         NULL,                           /* next */
 352         &ingress_class_ops,             /* cl_ops */
 353         "ingress",
 354         sizeof(struct ingress_qdisc_data),
 355
 356         ingress_enqueue,                /* enqueue */
 357         ingress_dequeue,                /* dequeue */
 358         ingress_requeue,                /* requeue */
 359         ingress_drop,                   /* drop */
 360
 361         ingress_init,                   /* init */
 362         ingress_reset,                  /* reset */
 363         ingress_destroy,                /* destroy */
 364         NULL,                           /* change */
 365
 366 #ifdef CONFIG_RTNETLINK
 367         ingress_dump,                   /* dump */
 368 #endif
 369 };
 370
 371 #ifdef MODULE
 372 int init_module(void)
 373 {
 374         int ret = 0;
 375
 376         if ((ret = register_qdisc(&ingress_qdisc_ops)) < 0) {
 377                 printk("Unable to register Ingress qdisc\n");
 378                 return ret;
 379         }
 380
 381         if (nf_register_hook(&ing_ops) < 0) {
 382                 printk("Unable to register ingress on hook \n");
 383                 unregister_qdisc(&ingress_qdisc_ops);
 384                 return 0;
 385         }
 386
 387         return ret;
 388 }
 389
 390
 391 void cleanup_module(void)
 392 {
 393         nf_unregister_hook(&ing_ops);
 394         unregister_qdisc(&ingress_qdisc_ops);
 395 }
 396 #endif