err.no Git - linux-2.6/blob - net/sched/sch_dsmark.c

   1 /* net/sched/sch_dsmark.c - Differentiated Services field marker */
   2
   3 /* Written 1998-2000 by Werner Almesberger, EPFL ICA */
   4
   5
   6 #include <linux/module.h>
   7 #include <linux/init.h>
   8 #include <linux/types.h>
   9 #include <linux/string.h>
  10 #include <linux/errno.h>
  11 #include <linux/skbuff.h>
  12 #include <linux/rtnetlink.h>
  13 #include <linux/bitops.h>
  14 #include <net/pkt_sched.h>
  15 #include <net/dsfield.h>
  16 #include <net/inet_ecn.h>
  17 #include <asm/byteorder.h>
  18
  19 /*
  20  * classid      class           marking
  21  * -------      -----           -------
  22  *   n/a          0             n/a
  23  *   x:0          1             use entry [0]
  24  *   ...         ...            ...
  25  *   x:y y>0     y+1            use entry [y]
  26  *   ...         ...            ...
  27  * x:indices-1  indices         use entry [indices-1]
  28  *   ...         ...            ...
  29  *   x:y         y+1            use entry [y & (indices-1)]
  30  *   ...         ...            ...
  31  * 0xffff       0x10000         use entry [indices-1]
  32  */
  33
  34
  35 #define NO_DEFAULT_INDEX        (1 << 16)
  36
  37 struct dsmark_qdisc_data {
  38         struct Qdisc            *q;
  39         struct tcf_proto        *filter_list;
  40         u8                      *mask;  /* "owns" the array */
  41         u8                      *value;
  42         u16                     indices;
  43         u32                     default_index;  /* index range is 0...0xffff */
  44         int                     set_tc_index;
  45 };
  46
  47 static inline int dsmark_valid_index(struct dsmark_qdisc_data *p, u16 index)
  48 {
  49         return (index <= p->indices && index > 0);
  50 }
  51
  52 /* ------------------------- Class/flow operations ------------------------- */
  53
  54 static int dsmark_graft(struct Qdisc *sch, unsigned long arg,
  55                         struct Qdisc *new, struct Qdisc **old)
  56 {
  57         struct dsmark_qdisc_data *p = qdisc_priv(sch);
  58
  59         pr_debug("dsmark_graft(sch %p,[qdisc %p],new %p,old %p)\n",
  60                 sch, p, new, old);
  61
  62         if (new == NULL) {
  63                 new = qdisc_create_dflt(sch->dev, &pfifo_qdisc_ops,
  64                                         sch->handle);
  65                 if (new == NULL)
  66                         new = &noop_qdisc;
  67         }
  68
  69         sch_tree_lock(sch);
  70         *old = xchg(&p->q, new);
  71         qdisc_tree_decrease_qlen(*old, (*old)->q.qlen);
  72         qdisc_reset(*old);
  73         sch_tree_unlock(sch);
  74
  75         return 0;
  76 }
  77
  78 static struct Qdisc *dsmark_leaf(struct Qdisc *sch, unsigned long arg)
  79 {
  80         struct dsmark_qdisc_data *p = qdisc_priv(sch);
  81         return p->q;
  82 }
  83
  84 static unsigned long dsmark_get(struct Qdisc *sch, u32 classid)
  85 {
  86         pr_debug("dsmark_get(sch %p,[qdisc %p],classid %x)\n",
  87                 sch, qdisc_priv(sch), classid);
  88
  89         return TC_H_MIN(classid) + 1;
  90 }
  91
  92 static unsigned long dsmark_bind_filter(struct Qdisc *sch,
  93                                         unsigned long parent, u32 classid)
  94 {
  95         return dsmark_get(sch, classid);
  96 }
  97
  98 static void dsmark_put(struct Qdisc *sch, unsigned long cl)
  99 {
 100 }
 101
 102 static int dsmark_change(struct Qdisc *sch, u32 classid, u32 parent,
 103                          struct rtattr **tca, unsigned long *arg)
 104 {
 105         struct dsmark_qdisc_data *p = qdisc_priv(sch);
 106         struct rtattr *opt = tca[TCA_OPTIONS-1];
 107         struct rtattr *tb[TCA_DSMARK_MAX];
 108         int err = -EINVAL;
 109         u8 mask = 0;
 110
 111         pr_debug("dsmark_change(sch %p,[qdisc %p],classid %x,parent %x),"
 112                 "arg 0x%lx\n", sch, p, classid, parent, *arg);
 113
 114         if (!dsmark_valid_index(p, *arg)) {
 115                 err = -ENOENT;
 116                 goto rtattr_failure;
 117         }
 118
 119         if (!opt || rtattr_parse_nested(tb, TCA_DSMARK_MAX, opt))
 120                 goto rtattr_failure;
 121
 122         if (tb[TCA_DSMARK_MASK-1])
 123                 mask = RTA_GET_U8(tb[TCA_DSMARK_MASK-1]);
 124
 125         if (tb[TCA_DSMARK_VALUE-1])
 126                 p->value[*arg-1] = RTA_GET_U8(tb[TCA_DSMARK_VALUE-1]);
 127
 128         if (tb[TCA_DSMARK_MASK-1])
 129                 p->mask[*arg-1] = mask;
 130
 131         err = 0;
 132
 133 rtattr_failure:
 134         return err;
 135 }
 136
 137 static int dsmark_delete(struct Qdisc *sch, unsigned long arg)
 138 {
 139         struct dsmark_qdisc_data *p = qdisc_priv(sch);
 140
 141         if (!dsmark_valid_index(p, arg))
 142                 return -EINVAL;
 143
 144         p->mask[arg-1] = 0xff;
 145         p->value[arg-1] = 0;
 146
 147         return 0;
 148 }
 149
 150 static void dsmark_walk(struct Qdisc *sch,struct qdisc_walker *walker)
 151 {
 152         struct dsmark_qdisc_data *p = qdisc_priv(sch);
 153         int i;
 154
 155         pr_debug("dsmark_walk(sch %p,[qdisc %p],walker %p)\n", sch, p, walker);
 156
 157         if (walker->stop)
 158                 return;
 159
 160         for (i = 0; i < p->indices; i++) {
 161                 if (p->mask[i] == 0xff && !p->value[i])
 162                         goto ignore;
 163                 if (walker->count >= walker->skip) {
 164                         if (walker->fn(sch, i+1, walker) < 0) {
 165                                 walker->stop = 1;
 166                                 break;
 167                         }
 168                 }
 169 ignore:
 170                 walker->count++;
 171         }
 172 }
 173
 174 static inline struct tcf_proto **dsmark_find_tcf(struct Qdisc *sch,unsigned long cl)
 175 {
 176         struct dsmark_qdisc_data *p = qdisc_priv(sch);
 177         return &p->filter_list;
 178 }
 179
 180 /* --------------------------- Qdisc operations ---------------------------- */
 181
 182 static int dsmark_enqueue(struct sk_buff *skb,struct Qdisc *sch)
 183 {
 184         struct dsmark_qdisc_data *p = qdisc_priv(sch);
 185         int err;
 186
 187         pr_debug("dsmark_enqueue(skb %p,sch %p,[qdisc %p])\n", skb, sch, p);
 188
 189         if (p->set_tc_index) {
 190                 /* FIXME: Safe with non-linear skbs? --RR */
 191                 switch (skb->protocol) {
 192                         case __constant_htons(ETH_P_IP):
 193                                 skb->tc_index = ipv4_get_dsfield(ip_hdr(skb))
 194                                         & ~INET_ECN_MASK;
 195                                 break;
 196                         case __constant_htons(ETH_P_IPV6):
 197                                 skb->tc_index = ipv6_get_dsfield(ipv6_hdr(skb))
 198                                         & ~INET_ECN_MASK;
 199                                 break;
 200                         default:
 201                                 skb->tc_index = 0;
 202                                 break;
 203                 }
 204         }
 205
 206         if (TC_H_MAJ(skb->priority) == sch->handle)
 207                 skb->tc_index = TC_H_MIN(skb->priority);
 208         else {
 209                 struct tcf_result res;
 210                 int result = tc_classify(skb, p->filter_list, &res);
 211
 212                 pr_debug("result %d class 0x%04x\n", result, res.classid);
 213
 214                 switch (result) {
 215 #ifdef CONFIG_NET_CLS_ACT
 216                 case TC_ACT_QUEUED:
 217                 case TC_ACT_STOLEN:
 218                         kfree_skb(skb);
 219                         return NET_XMIT_SUCCESS;
 220                 case TC_ACT_SHOT:
 221                         kfree_skb(skb);
 222                         sch->qstats.drops++;
 223                         return NET_XMIT_BYPASS;
 224 #endif
 225                 case TC_ACT_OK:
 226                         skb->tc_index = TC_H_MIN(res.classid);
 227                         break;
 228                 default:
 229                         if (p->default_index != NO_DEFAULT_INDEX)
 230                                 skb->tc_index = p->default_index;
 231                         break;
 232                 }
 233         }
 234
 235         err = p->q->enqueue(skb,p->q);
 236         if (err != NET_XMIT_SUCCESS) {
 237                 sch->qstats.drops++;
 238                 return err;
 239         }
 240
 241         sch->bstats.bytes += skb->len;
 242         sch->bstats.packets++;
 243         sch->q.qlen++;
 244
 245         return NET_XMIT_SUCCESS;
 246 }
 247
 248 static struct sk_buff *dsmark_dequeue(struct Qdisc *sch)
 249 {
 250         struct dsmark_qdisc_data *p = qdisc_priv(sch);
 251         struct sk_buff *skb;
 252         u32 index;
 253
 254         pr_debug("dsmark_dequeue(sch %p,[qdisc %p])\n", sch, p);
 255
 256         skb = p->q->ops->dequeue(p->q);
 257         if (skb == NULL)
 258                 return NULL;
 259
 260         sch->q.qlen--;
 261
 262         index = skb->tc_index & (p->indices - 1);
 263         pr_debug("index %d->%d\n", skb->tc_index, index);
 264
 265         switch (skb->protocol) {
 266                 case __constant_htons(ETH_P_IP):
 267                         ipv4_change_dsfield(ip_hdr(skb), p->mask[index],
 268                                             p->value[index]);
 269                         break;
 270                 case __constant_htons(ETH_P_IPV6):
 271                         ipv6_change_dsfield(ipv6_hdr(skb), p->mask[index],
 272                                             p->value[index]);
 273                         break;
 274                 default:
 275                         /*
 276                          * Only complain if a change was actually attempted.
 277                          * This way, we can send non-IP traffic through dsmark
 278                          * and don't need yet another qdisc as a bypass.
 279                          */
 280                         if (p->mask[index] != 0xff || p->value[index])
 281                                 printk(KERN_WARNING "dsmark_dequeue: "
 282                                        "unsupported protocol %d\n",
 283                                        ntohs(skb->protocol));
 284                         break;
 285         }
 286
 287         return skb;
 288 }
 289
 290 static int dsmark_requeue(struct sk_buff *skb,struct Qdisc *sch)
 291 {
 292         struct dsmark_qdisc_data *p = qdisc_priv(sch);
 293         int err;
 294
 295         pr_debug("dsmark_requeue(skb %p,sch %p,[qdisc %p])\n", skb, sch, p);
 296
 297         err = p->q->ops->requeue(skb, p->q);
 298         if (err != NET_XMIT_SUCCESS) {
 299                 sch->qstats.drops++;
 300                 return err;
 301         }
 302
 303         sch->q.qlen++;
 304         sch->qstats.requeues++;
 305
 306         return NET_XMIT_SUCCESS;
 307 }
 308
 309 static unsigned int dsmark_drop(struct Qdisc *sch)
 310 {
 311         struct dsmark_qdisc_data *p = qdisc_priv(sch);
 312         unsigned int len;
 313
 314         pr_debug("dsmark_reset(sch %p,[qdisc %p])\n", sch, p);
 315
 316         if (p->q->ops->drop == NULL)
 317                 return 0;
 318
 319         len = p->q->ops->drop(p->q);
 320         if (len)
 321                 sch->q.qlen--;
 322
 323         return len;
 324 }
 325
 326 static int dsmark_init(struct Qdisc *sch, struct rtattr *opt)
 327 {
 328         struct dsmark_qdisc_data *p = qdisc_priv(sch);
 329         struct rtattr *tb[TCA_DSMARK_MAX];
 330         int err = -EINVAL;
 331         u32 default_index = NO_DEFAULT_INDEX;
 332         u16 indices;
 333         u8 *mask;
 334
 335         pr_debug("dsmark_init(sch %p,[qdisc %p],opt %p)\n", sch, p, opt);
 336
 337         if (!opt || rtattr_parse_nested(tb, TCA_DSMARK_MAX, opt) < 0)
 338                 goto errout;
 339
 340         indices = RTA_GET_U16(tb[TCA_DSMARK_INDICES-1]);
 341
 342         if (hweight32(indices) != 1)
 343                 goto errout;
 344
 345         if (tb[TCA_DSMARK_DEFAULT_INDEX-1])
 346                 default_index = RTA_GET_U16(tb[TCA_DSMARK_DEFAULT_INDEX-1]);
 347
 348         mask = kmalloc(indices * 2, GFP_KERNEL);
 349         if (mask == NULL) {
 350                 err = -ENOMEM;
 351                 goto errout;
 352         }
 353
 354         p->mask = mask;
 355         memset(p->mask, 0xff, indices);
 356
 357         p->value = p->mask + indices;
 358         memset(p->value, 0, indices);
 359
 360         p->indices = indices;
 361         p->default_index = default_index;
 362         p->set_tc_index = RTA_GET_FLAG(tb[TCA_DSMARK_SET_TC_INDEX-1]);
 363
 364         p->q = qdisc_create_dflt(sch->dev, &pfifo_qdisc_ops, sch->handle);
 365         if (p->q == NULL)
 366                 p->q = &noop_qdisc;
 367
 368         pr_debug("dsmark_init: qdisc %p\n", p->q);
 369
 370         err = 0;
 371 errout:
 372 rtattr_failure:
 373         return err;
 374 }
 375
 376 static void dsmark_reset(struct Qdisc *sch)
 377 {
 378         struct dsmark_qdisc_data *p = qdisc_priv(sch);
 379
 380         pr_debug("dsmark_reset(sch %p,[qdisc %p])\n", sch, p);
 381         qdisc_reset(p->q);
 382         sch->q.qlen = 0;
 383 }
 384
 385 static void dsmark_destroy(struct Qdisc *sch)
 386 {
 387         struct dsmark_qdisc_data *p = qdisc_priv(sch);
 388
 389         pr_debug("dsmark_destroy(sch %p,[qdisc %p])\n", sch, p);
 390
 391         tcf_destroy_chain(p->filter_list);
 392         qdisc_destroy(p->q);
 393         kfree(p->mask);
 394 }
 395
 396 static int dsmark_dump_class(struct Qdisc *sch, unsigned long cl,
 397                              struct sk_buff *skb, struct tcmsg *tcm)
 398 {
 399         struct dsmark_qdisc_data *p = qdisc_priv(sch);
 400         struct rtattr *opts = NULL;
 401
 402         pr_debug("dsmark_dump_class(sch %p,[qdisc %p],class %ld\n", sch, p, cl);
 403
 404         if (!dsmark_valid_index(p, cl))
 405                 return -EINVAL;
 406
 407         tcm->tcm_handle = TC_H_MAKE(TC_H_MAJ(sch->handle), cl-1);
 408         tcm->tcm_info = p->q->handle;
 409
 410         opts = RTA_NEST(skb, TCA_OPTIONS);
 411         RTA_PUT_U8(skb,TCA_DSMARK_MASK, p->mask[cl-1]);
 412         RTA_PUT_U8(skb,TCA_DSMARK_VALUE, p->value[cl-1]);
 413
 414         return RTA_NEST_END(skb, opts);
 415
 416 rtattr_failure:
 417         return RTA_NEST_CANCEL(skb, opts);
 418 }
 419
 420 static int dsmark_dump(struct Qdisc *sch, struct sk_buff *skb)
 421 {
 422         struct dsmark_qdisc_data *p = qdisc_priv(sch);
 423         struct rtattr *opts = NULL;
 424
 425         opts = RTA_NEST(skb, TCA_OPTIONS);
 426         RTA_PUT_U16(skb, TCA_DSMARK_INDICES, p->indices);
 427
 428         if (p->default_index != NO_DEFAULT_INDEX)
 429                 RTA_PUT_U16(skb, TCA_DSMARK_DEFAULT_INDEX, p->default_index);
 430
 431         if (p->set_tc_index)
 432                 RTA_PUT_FLAG(skb, TCA_DSMARK_SET_TC_INDEX);
 433
 434         return RTA_NEST_END(skb, opts);
 435
 436 rtattr_failure:
 437         return RTA_NEST_CANCEL(skb, opts);
 438 }
 439
 440 static const struct Qdisc_class_ops dsmark_class_ops = {
 441         .graft          =       dsmark_graft,
 442         .leaf           =       dsmark_leaf,
 443         .get            =       dsmark_get,
 444         .put            =       dsmark_put,
 445         .change         =       dsmark_change,
 446         .delete         =       dsmark_delete,
 447         .walk           =       dsmark_walk,
 448         .tcf_chain      =       dsmark_find_tcf,
 449         .bind_tcf       =       dsmark_bind_filter,
 450         .unbind_tcf     =       dsmark_put,
 451         .dump           =       dsmark_dump_class,
 452 };
 453
 454 static struct Qdisc_ops dsmark_qdisc_ops __read_mostly = {
 455         .next           =       NULL,
 456         .cl_ops         =       &dsmark_class_ops,
 457         .id             =       "dsmark",
 458         .priv_size      =       sizeof(struct dsmark_qdisc_data),
 459         .enqueue        =       dsmark_enqueue,
 460         .dequeue        =       dsmark_dequeue,
 461         .requeue        =       dsmark_requeue,
 462         .drop           =       dsmark_drop,
 463         .init           =       dsmark_init,
 464         .reset          =       dsmark_reset,
 465         .destroy        =       dsmark_destroy,
 466         .change         =       NULL,
 467         .dump           =       dsmark_dump,
 468         .owner          =       THIS_MODULE,
 469 };
 470
 471 static int __init dsmark_module_init(void)
 472 {
 473         return register_qdisc(&dsmark_qdisc_ops);
 474 }
 475
 476 static void __exit dsmark_module_exit(void)
 477 {
 478         unregister_qdisc(&dsmark_qdisc_ops);
 479 }
 480
 481 module_init(dsmark_module_init)
 482 module_exit(dsmark_module_exit)
 483
 484 MODULE_LICENSE("GPL");