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/config.h>
   7 #include <linux/module.h>
   8 #include <linux/init.h>
   9 #include <linux/types.h>
  10 #include <linux/string.h>
  11 #include <linux/errno.h>
  12 #include <linux/skbuff.h>
  13 #include <linux/netdevice.h> /* for pkt_sched */
  14 #include <linux/rtnetlink.h>
  15 #include <net/pkt_sched.h>
  16 #include <net/dsfield.h>
  17 #include <net/inet_ecn.h>
  18 #include <asm/byteorder.h>
  19
  20
  21 #if 0 /* control */
  22 #define DPRINTK(format,args...) printk(KERN_DEBUG format,##args)
  23 #else
  24 #define DPRINTK(format,args...)
  25 #endif
  26
  27 #if 0 /* data */
  28 #define D2PRINTK(format,args...) printk(KERN_DEBUG format,##args)
  29 #else
  30 #define D2PRINTK(format,args...)
  31 #endif
  32
  33
  34 #define PRIV(sch) ((struct dsmark_qdisc_data *) qdisc_priv(sch))
  35
  36
  37 /*
  38  * classid      class           marking
  39  * -------      -----           -------
  40  *   n/a          0             n/a
  41  *   x:0          1             use entry [0]
  42  *   ...         ...            ...
  43  *   x:y y>0     y+1            use entry [y]
  44  *   ...         ...            ...
  45  * x:indices-1  indices         use entry [indices-1]
  46  *   ...         ...            ...
  47  *   x:y         y+1            use entry [y & (indices-1)]
  48  *   ...         ...            ...
  49  * 0xffff       0x10000         use entry [indices-1]
  50  */
  51
  52
  53 #define NO_DEFAULT_INDEX        (1 << 16)
  54
  55 struct dsmark_qdisc_data {
  56         struct Qdisc            *q;
  57         struct tcf_proto        *filter_list;
  58         u8                      *mask;  /* "owns" the array */
  59         u8                      *value;
  60         u16                     indices;
  61         u32                     default_index;  /* index range is 0...0xffff */
  62         int                     set_tc_index;
  63 };
  64
  65 static inline int dsmark_valid_indices(u16 indices)
  66 {
  67         while (indices != 1) {
  68                 if (indices & 1)
  69                         return 0;
  70                 indices >>= 1;
  71         }
  72
  73         return 1;
  74 }
  75
  76 static inline int dsmark_valid_index(struct dsmark_qdisc_data *p, u16 index)
  77 {
  78         return (index <= p->indices && index > 0);
  79 }
  80
  81 /* ------------------------- Class/flow operations ------------------------- */
  82
  83 static int dsmark_graft(struct Qdisc *sch, unsigned long arg,
  84                         struct Qdisc *new, struct Qdisc **old)
  85 {
  86         struct dsmark_qdisc_data *p = PRIV(sch);
  87
  88         DPRINTK("dsmark_graft(sch %p,[qdisc %p],new %p,old %p)\n",
  89                 sch, p, new, old);
  90
  91         if (new == NULL) {
  92                 new = qdisc_create_dflt(sch->dev, &pfifo_qdisc_ops);
  93                 if (new == NULL)
  94                         new = &noop_qdisc;
  95         }
  96
  97         sch_tree_lock(sch);
  98         *old = xchg(&p->q, new);
  99         qdisc_reset(*old);
 100         sch->q.qlen = 0;
 101         sch_tree_unlock(sch);
 102
 103         return 0;
 104 }
 105
 106 static struct Qdisc *dsmark_leaf(struct Qdisc *sch, unsigned long arg)
 107 {
 108         return PRIV(sch)->q;
 109 }
 110
 111 static unsigned long dsmark_get(struct Qdisc *sch, u32 classid)
 112 {
 113         DPRINTK("dsmark_get(sch %p,[qdisc %p],classid %x)\n",
 114                 sch, PRIV(sch), classid);
 115
 116         return TC_H_MIN(classid) + 1;
 117 }
 118
 119 static unsigned long dsmark_bind_filter(struct Qdisc *sch,
 120                                         unsigned long parent, u32 classid)
 121 {
 122         return dsmark_get(sch, classid);
 123 }
 124
 125 static void dsmark_put(struct Qdisc *sch, unsigned long cl)
 126 {
 127 }
 128
 129 static int dsmark_change(struct Qdisc *sch, u32 classid, u32 parent,
 130                          struct rtattr **tca, unsigned long *arg)
 131 {
 132         struct dsmark_qdisc_data *p = PRIV(sch);
 133         struct rtattr *opt = tca[TCA_OPTIONS-1];
 134         struct rtattr *tb[TCA_DSMARK_MAX];
 135         int err = -EINVAL;
 136         u8 mask = 0;
 137
 138         DPRINTK("dsmark_change(sch %p,[qdisc %p],classid %x,parent %x),"
 139                 "arg 0x%lx\n", sch, p, classid, parent, *arg);
 140
 141         if (!dsmark_valid_index(p, *arg)) {
 142                 err = -ENOENT;
 143                 goto rtattr_failure;
 144         }
 145
 146         if (!opt || rtattr_parse_nested(tb, TCA_DSMARK_MAX, opt))
 147                 goto rtattr_failure;
 148
 149         if (tb[TCA_DSMARK_MASK-1])
 150                 mask = RTA_GET_U8(tb[TCA_DSMARK_MASK-1]);
 151
 152         if (tb[TCA_DSMARK_VALUE-1])
 153                 p->value[*arg-1] = RTA_GET_U8(tb[TCA_DSMARK_VALUE-1]);
 154
 155         if (tb[TCA_DSMARK_MASK-1])
 156                 p->mask[*arg-1] = mask;
 157
 158         err = 0;
 159
 160 rtattr_failure:
 161         return err;
 162 }
 163
 164 static int dsmark_delete(struct Qdisc *sch, unsigned long arg)
 165 {
 166         struct dsmark_qdisc_data *p = PRIV(sch);
 167
 168         if (!dsmark_valid_index(p, arg))
 169                 return -EINVAL;
 170
 171         p->mask[arg-1] = 0xff;
 172         p->value[arg-1] = 0;
 173
 174         return 0;
 175 }
 176
 177 static void dsmark_walk(struct Qdisc *sch,struct qdisc_walker *walker)
 178 {
 179         struct dsmark_qdisc_data *p = PRIV(sch);
 180         int i;
 181
 182         DPRINTK("dsmark_walk(sch %p,[qdisc %p],walker %p)\n", sch, p, walker);
 183
 184         if (walker->stop)
 185                 return;
 186
 187         for (i = 0; i < p->indices; i++) {
 188                 if (p->mask[i] == 0xff && !p->value[i])
 189                         goto ignore;
 190                 if (walker->count >= walker->skip) {
 191                         if (walker->fn(sch, i+1, walker) < 0) {
 192                                 walker->stop = 1;
 193                                 break;
 194                         }
 195                 }
 196 ignore:
 197                 walker->count++;
 198         }
 199 }
 200
 201 static struct tcf_proto **dsmark_find_tcf(struct Qdisc *sch,unsigned long cl)
 202 {
 203         return &PRIV(sch)->filter_list;
 204 }
 205
 206 /* --------------------------- Qdisc operations ---------------------------- */
 207
 208 static int dsmark_enqueue(struct sk_buff *skb,struct Qdisc *sch)
 209 {
 210         struct dsmark_qdisc_data *p = PRIV(sch);
 211         int err;
 212
 213         D2PRINTK("dsmark_enqueue(skb %p,sch %p,[qdisc %p])\n", skb, sch, p);
 214
 215         if (p->set_tc_index) {
 216                 /* FIXME: Safe with non-linear skbs? --RR */
 217                 switch (skb->protocol) {
 218                         case __constant_htons(ETH_P_IP):
 219                                 skb->tc_index = ipv4_get_dsfield(skb->nh.iph)
 220                                         & ~INET_ECN_MASK;
 221                                 break;
 222                         case __constant_htons(ETH_P_IPV6):
 223                                 skb->tc_index = ipv6_get_dsfield(skb->nh.ipv6h)
 224                                         & ~INET_ECN_MASK;
 225                                 break;
 226                         default:
 227                                 skb->tc_index = 0;
 228                                 break;
 229                 };
 230         }
 231
 232         if (TC_H_MAJ(skb->priority) == sch->handle)
 233                 skb->tc_index = TC_H_MIN(skb->priority);
 234         else {
 235                 struct tcf_result res;
 236                 int result = tc_classify(skb, p->filter_list, &res);
 237
 238                 D2PRINTK("result %d class 0x%04x\n", result, res.classid);
 239
 240                 switch (result) {
 241 #ifdef CONFIG_NET_CLS_POLICE
 242                         case TC_POLICE_SHOT:
 243                                 kfree_skb(skb);
 244                                 sch->qstats.drops++;
 245                                 return NET_XMIT_POLICED;
 246 #if 0
 247                         case TC_POLICE_RECLASSIFY:
 248                                 /* FIXME: what to do here ??? */
 249 #endif
 250 #endif
 251                         case TC_POLICE_OK:
 252                                 skb->tc_index = TC_H_MIN(res.classid);
 253                                 break;
 254                         case TC_POLICE_UNSPEC:
 255                                 /* fall through */
 256                         default:
 257                                 if (p->default_index != NO_DEFAULT_INDEX)
 258                                         skb->tc_index = p->default_index;
 259                                 break;
 260                 };
 261         }
 262
 263         err = p->q->enqueue(skb,p->q);
 264         if (err != NET_XMIT_SUCCESS) {
 265                 sch->qstats.drops++;
 266                 return err;
 267         }
 268
 269         sch->bstats.bytes += skb->len;
 270         sch->bstats.packets++;
 271         sch->q.qlen++;
 272
 273         return NET_XMIT_SUCCESS;
 274 }
 275
 276 static struct sk_buff *dsmark_dequeue(struct Qdisc *sch)
 277 {
 278         struct dsmark_qdisc_data *p = PRIV(sch);
 279         struct sk_buff *skb;
 280         u32 index;
 281
 282         D2PRINTK("dsmark_dequeue(sch %p,[qdisc %p])\n", sch, p);
 283
 284         skb = p->q->ops->dequeue(p->q);
 285         if (skb == NULL)
 286                 return NULL;
 287
 288         sch->q.qlen--;
 289
 290         index = skb->tc_index & (p->indices - 1);
 291         D2PRINTK("index %d->%d\n", skb->tc_index, index);
 292
 293         switch (skb->protocol) {
 294                 case __constant_htons(ETH_P_IP):
 295                         ipv4_change_dsfield(skb->nh.iph, p->mask[index],
 296                                             p->value[index]);
 297                         break;
 298                 case __constant_htons(ETH_P_IPV6):
 299                         ipv6_change_dsfield(skb->nh.ipv6h, p->mask[index],
 300                                             p->value[index]);
 301                         break;
 302                 default:
 303                         /*
 304                          * Only complain if a change was actually attempted.
 305                          * This way, we can send non-IP traffic through dsmark
 306                          * and don't need yet another qdisc as a bypass.
 307                          */
 308                         if (p->mask[index] != 0xff || p->value[index])
 309                                 printk(KERN_WARNING "dsmark_dequeue: "
 310                                        "unsupported protocol %d\n",
 311                                        htons(skb->protocol));
 312                         break;
 313         };
 314
 315         return skb;
 316 }
 317
 318 static int dsmark_requeue(struct sk_buff *skb,struct Qdisc *sch)
 319 {
 320         struct dsmark_qdisc_data *p = PRIV(sch);
 321         int err;
 322
 323         D2PRINTK("dsmark_requeue(skb %p,sch %p,[qdisc %p])\n", skb, sch, p);
 324
 325         err = p->q->ops->requeue(skb, p->q);
 326         if (err != NET_XMIT_SUCCESS) {
 327                 sch->qstats.drops++;
 328                 return err;
 329         }
 330
 331         sch->q.qlen++;
 332         sch->qstats.requeues++;
 333
 334         return NET_XMIT_SUCCESS;
 335 }
 336
 337 static unsigned int dsmark_drop(struct Qdisc *sch)
 338 {
 339         struct dsmark_qdisc_data *p = PRIV(sch);
 340         unsigned int len;
 341
 342         DPRINTK("dsmark_reset(sch %p,[qdisc %p])\n", sch, p);
 343
 344         if (p->q->ops->drop == NULL)
 345                 return 0;
 346
 347         len = p->q->ops->drop(p->q);
 348         if (len)
 349                 sch->q.qlen--;
 350
 351         return len;
 352 }
 353
 354 static int dsmark_init(struct Qdisc *sch, struct rtattr *opt)
 355 {
 356         struct dsmark_qdisc_data *p = PRIV(sch);
 357         struct rtattr *tb[TCA_DSMARK_MAX];
 358         int err = -EINVAL;
 359         u32 default_index = NO_DEFAULT_INDEX;
 360         u16 indices;
 361         u8 *mask;
 362
 363         DPRINTK("dsmark_init(sch %p,[qdisc %p],opt %p)\n", sch, p, opt);
 364
 365         if (!opt || rtattr_parse_nested(tb, TCA_DSMARK_MAX, opt) < 0)
 366                 goto errout;
 367
 368         indices = RTA_GET_U16(tb[TCA_DSMARK_INDICES-1]);
 369         if (!indices || !dsmark_valid_indices(indices))
 370                 goto errout;
 371
 372         if (tb[TCA_DSMARK_DEFAULT_INDEX-1])
 373                 default_index = RTA_GET_U16(tb[TCA_DSMARK_DEFAULT_INDEX-1]);
 374
 375         mask = kmalloc(indices * 2, GFP_KERNEL);
 376         if (mask == NULL) {
 377                 err = -ENOMEM;
 378                 goto errout;
 379         }
 380
 381         p->mask = mask;
 382         memset(p->mask, 0xff, indices);
 383
 384         p->value = p->mask + indices;
 385         memset(p->value, 0, indices);
 386
 387         p->indices = indices;
 388         p->default_index = default_index;
 389         p->set_tc_index = RTA_GET_FLAG(tb[TCA_DSMARK_SET_TC_INDEX-1]);
 390
 391         p->q = qdisc_create_dflt(sch->dev, &pfifo_qdisc_ops);
 392         if (p->q == NULL)
 393                 p->q = &noop_qdisc;
 394
 395         DPRINTK("dsmark_init: qdisc %p\n", p->q);
 396
 397         err = 0;
 398 errout:
 399 rtattr_failure:
 400         return err;
 401 }
 402
 403 static void dsmark_reset(struct Qdisc *sch)
 404 {
 405         struct dsmark_qdisc_data *p = PRIV(sch);
 406
 407         DPRINTK("dsmark_reset(sch %p,[qdisc %p])\n", sch, p);
 408         qdisc_reset(p->q);
 409         sch->q.qlen = 0;
 410 }
 411
 412 static void dsmark_destroy(struct Qdisc *sch)
 413 {
 414         struct dsmark_qdisc_data *p = PRIV(sch);
 415         struct tcf_proto *tp;
 416
 417         DPRINTK("dsmark_destroy(sch %p,[qdisc %p])\n", sch, p);
 418
 419         while (p->filter_list) {
 420                 tp = p->filter_list;
 421                 p->filter_list = tp->next;
 422                 tcf_destroy(tp);
 423         }
 424
 425         qdisc_destroy(p->q);
 426         kfree(p->mask);
 427 }
 428
 429 static int dsmark_dump_class(struct Qdisc *sch, unsigned long cl,
 430                              struct sk_buff *skb, struct tcmsg *tcm)
 431 {
 432         struct dsmark_qdisc_data *p = PRIV(sch);
 433         struct rtattr *opts = NULL;
 434
 435         DPRINTK("dsmark_dump_class(sch %p,[qdisc %p],class %ld\n", sch, p, cl);
 436
 437         if (!dsmark_valid_index(p, cl))
 438                 return -EINVAL;
 439
 440         tcm->tcm_handle = TC_H_MAKE(TC_H_MAJ(sch->handle), cl-1);
 441
 442         opts = RTA_NEST(skb, TCA_OPTIONS);
 443         RTA_PUT_U8(skb,TCA_DSMARK_MASK, p->mask[cl-1]);
 444         RTA_PUT_U8(skb,TCA_DSMARK_VALUE, p->value[cl-1]);
 445
 446         return RTA_NEST_END(skb, opts);
 447
 448 rtattr_failure:
 449         return RTA_NEST_CANCEL(skb, opts);
 450 }
 451
 452 static int dsmark_dump(struct Qdisc *sch, struct sk_buff *skb)
 453 {
 454         struct dsmark_qdisc_data *p = PRIV(sch);
 455         struct rtattr *opts = NULL;
 456
 457         opts = RTA_NEST(skb, TCA_OPTIONS);
 458         RTA_PUT_U16(skb, TCA_DSMARK_INDICES, p->indices);
 459
 460         if (p->default_index != NO_DEFAULT_INDEX)
 461                 RTA_PUT_U16(skb, TCA_DSMARK_DEFAULT_INDEX, p->default_index);
 462
 463         if (p->set_tc_index)
 464                 RTA_PUT_FLAG(skb, TCA_DSMARK_SET_TC_INDEX);
 465
 466         return RTA_NEST_END(skb, opts);
 467
 468 rtattr_failure:
 469         return RTA_NEST_CANCEL(skb, opts);
 470 }
 471
 472 static struct Qdisc_class_ops dsmark_class_ops = {
 473         .graft          =       dsmark_graft,
 474         .leaf           =       dsmark_leaf,
 475         .get            =       dsmark_get,
 476         .put            =       dsmark_put,
 477         .change         =       dsmark_change,
 478         .delete         =       dsmark_delete,
 479         .walk           =       dsmark_walk,
 480         .tcf_chain      =       dsmark_find_tcf,
 481         .bind_tcf       =       dsmark_bind_filter,
 482         .unbind_tcf     =       dsmark_put,
 483         .dump           =       dsmark_dump_class,
 484 };
 485
 486 static struct Qdisc_ops dsmark_qdisc_ops = {
 487         .next           =       NULL,
 488         .cl_ops         =       &dsmark_class_ops,
 489         .id             =       "dsmark",
 490         .priv_size      =       sizeof(struct dsmark_qdisc_data),
 491         .enqueue        =       dsmark_enqueue,
 492         .dequeue        =       dsmark_dequeue,
 493         .requeue        =       dsmark_requeue,
 494         .drop           =       dsmark_drop,
 495         .init           =       dsmark_init,
 496         .reset          =       dsmark_reset,
 497         .destroy        =       dsmark_destroy,
 498         .change         =       NULL,
 499         .dump           =       dsmark_dump,
 500         .owner          =       THIS_MODULE,
 501 };
 502
 503 static int __init dsmark_module_init(void)
 504 {
 505         return register_qdisc(&dsmark_qdisc_ops);
 506 }
 507
 508 static void __exit dsmark_module_exit(void)
 509 {
 510         unregister_qdisc(&dsmark_qdisc_ops);
 511 }
 512
 513 module_init(dsmark_module_init)
 514 module_exit(dsmark_module_exit)
 515
 516 MODULE_LICENSE("GPL");