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   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) 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
  84 static int dsmark_graft(struct Qdisc *sch,unsigned long arg,
  85     struct Qdisc *new,struct Qdisc **old)
  86 {
  87         struct dsmark_qdisc_data *p = PRIV(sch);
  88
  89         DPRINTK("dsmark_graft(sch %p,[qdisc %p],new %p,old %p)\n",sch,p,new,
  90             old);
  91
  92         if (new == NULL) {
  93                 new = qdisc_create_dflt(sch->dev, &pfifo_qdisc_ops);
  94                 if (new == NULL)
  95                         new = &noop_qdisc;
  96         }
  97
  98         sch_tree_lock(sch);
  99         *old = xchg(&p->q,new);
 100         if (*old)
 101                 qdisc_reset(*old);
 102         sch->q.qlen = 0;
 103         sch_tree_unlock(sch); /* @@@ move up ? */
 104         return 0;
 105 }
 106
 107
 108 static struct Qdisc *dsmark_leaf(struct Qdisc *sch, unsigned long arg)
 109 {
 110         struct dsmark_qdisc_data *p = PRIV(sch);
 111
 112         return p->q;
 113 }
 114
 115
 116 static unsigned long dsmark_get(struct Qdisc *sch,u32 classid)
 117 {
 118         struct dsmark_qdisc_data *p __attribute__((unused)) = PRIV(sch);
 119
 120         DPRINTK("dsmark_get(sch %p,[qdisc %p],classid %x)\n",sch,p,classid);
 121         return TC_H_MIN(classid)+1;
 122 }
 123
 124
 125 static unsigned long dsmark_bind_filter(struct Qdisc *sch,
 126     unsigned long parent, u32 classid)
 127 {
 128         return dsmark_get(sch,classid);
 129 }
 130
 131
 132 static void dsmark_put(struct Qdisc *sch, unsigned long cl)
 133 {
 134 }
 135
 136
 137 static int dsmark_change(struct Qdisc *sch, u32 classid, u32 parent,
 138                          struct rtattr **tca, unsigned long *arg)
 139 {
 140         struct dsmark_qdisc_data *p = PRIV(sch);
 141         struct rtattr *opt = tca[TCA_OPTIONS-1];
 142         struct rtattr *tb[TCA_DSMARK_MAX];
 143         int err = -EINVAL;
 144         u8 mask = 0;
 145
 146         DPRINTK("dsmark_change(sch %p,[qdisc %p],classid %x,parent %x),"
 147                 "arg 0x%lx\n", sch, p, classid, parent, *arg);
 148
 149         if (!dsmark_valid_index(p, *arg)) {
 150                 err = -ENOENT;
 151                 goto rtattr_failure;
 152         }
 153
 154         if (!opt || rtattr_parse_nested(tb, TCA_DSMARK_MAX, opt))
 155                 goto rtattr_failure;
 156
 157         if (tb[TCA_DSMARK_MASK-1])
 158                 mask = RTA_GET_U8(tb[TCA_DSMARK_MASK-1]);
 159
 160         if (tb[TCA_DSMARK_VALUE-1])
 161                 p->value[*arg-1] = RTA_GET_U8(tb[TCA_DSMARK_VALUE-1]);
 162
 163         if (tb[TCA_DSMARK_MASK-1])
 164                 p->mask[*arg-1] = mask;
 165
 166         err = 0;
 167
 168 rtattr_failure:
 169         return err;
 170 }
 171
 172 static int dsmark_delete(struct Qdisc *sch,unsigned long arg)
 173 {
 174         struct dsmark_qdisc_data *p = PRIV(sch);
 175
 176         if (!arg || arg > p->indices)
 177                 return -EINVAL;
 178         p->mask[arg-1] = 0xff;
 179         p->value[arg-1] = 0;
 180         return 0;
 181 }
 182
 183
 184 static void dsmark_walk(struct Qdisc *sch,struct qdisc_walker *walker)
 185 {
 186         struct dsmark_qdisc_data *p = PRIV(sch);
 187         int i;
 188
 189         DPRINTK("dsmark_walk(sch %p,[qdisc %p],walker %p)\n",sch,p,walker);
 190         if (walker->stop)
 191                 return;
 192         for (i = 0; i < p->indices; i++) {
 193                 if (p->mask[i] == 0xff && !p->value[i])
 194                         goto ignore;
 195                 if (walker->count >= walker->skip) {
 196                         if (walker->fn(sch, i+1, walker) < 0) {
 197                                 walker->stop = 1;
 198                                 break;
 199                         }
 200                 }
 201 ignore:
 202                 walker->count++;
 203         }
 204 }
 205
 206
 207 static struct tcf_proto **dsmark_find_tcf(struct Qdisc *sch,unsigned long cl)
 208 {
 209         struct dsmark_qdisc_data *p = PRIV(sch);
 210
 211         return &p->filter_list;
 212 }
 213
 214
 215 /* --------------------------- Qdisc operations ---------------------------- */
 216
 217
 218 static int dsmark_enqueue(struct sk_buff *skb,struct Qdisc *sch)
 219 {
 220         struct dsmark_qdisc_data *p = PRIV(sch);
 221         struct tcf_result res;
 222         int result;
 223         int ret = NET_XMIT_POLICED;
 224
 225         D2PRINTK("dsmark_enqueue(skb %p,sch %p,[qdisc %p])\n",skb,sch,p);
 226         if (p->set_tc_index) {
 227                 /* FIXME: Safe with non-linear skbs? --RR */
 228                 switch (skb->protocol) {
 229                         case __constant_htons(ETH_P_IP):
 230                                 skb->tc_index = ipv4_get_dsfield(skb->nh.iph)
 231                                         & ~INET_ECN_MASK;
 232                                 break;
 233                         case __constant_htons(ETH_P_IPV6):
 234                                 skb->tc_index = ipv6_get_dsfield(skb->nh.ipv6h)
 235                                         & ~INET_ECN_MASK;
 236                                 break;
 237                         default:
 238                                 skb->tc_index = 0;
 239                                 break;
 240                 };
 241         }
 242         result = TC_POLICE_OK; /* be nice to gcc */
 243         if (TC_H_MAJ(skb->priority) == sch->handle) {
 244                 skb->tc_index = TC_H_MIN(skb->priority);
 245         } else {
 246                 result = tc_classify(skb,p->filter_list,&res);
 247                 D2PRINTK("result %d class 0x%04x\n",result,res.classid);
 248                 switch (result) {
 249 #ifdef CONFIG_NET_CLS_POLICE
 250                         case TC_POLICE_SHOT:
 251                                 kfree_skb(skb);
 252                                 break;
 253 #if 0
 254                         case TC_POLICE_RECLASSIFY:
 255                                 /* FIXME: what to do here ??? */
 256 #endif
 257 #endif
 258                         case TC_POLICE_OK:
 259                                 skb->tc_index = TC_H_MIN(res.classid);
 260                                 break;
 261                         case TC_POLICE_UNSPEC:
 262                                 /* fall through */
 263                         default:
 264                                 if (p->default_index != NO_DEFAULT_INDEX)
 265                                         skb->tc_index = p->default_index;
 266                                 break;
 267                 };
 268         }
 269         if (
 270 #ifdef CONFIG_NET_CLS_POLICE
 271             result == TC_POLICE_SHOT ||
 272 #endif
 273
 274             ((ret = p->q->enqueue(skb,p->q)) != 0)) {
 275                 sch->qstats.drops++;
 276                 return ret;
 277         }
 278         sch->bstats.bytes += skb->len;
 279         sch->bstats.packets++;
 280         sch->q.qlen++;
 281         return ret;
 282 }
 283
 284
 285 static struct sk_buff *dsmark_dequeue(struct Qdisc *sch)
 286 {
 287         struct dsmark_qdisc_data *p = PRIV(sch);
 288         struct sk_buff *skb;
 289         int index;
 290
 291         D2PRINTK("dsmark_dequeue(sch %p,[qdisc %p])\n",sch,p);
 292         skb = p->q->ops->dequeue(p->q);
 293         if (!skb)
 294                 return NULL;
 295         sch->q.qlen--;
 296         index = skb->tc_index & (p->indices-1);
 297         D2PRINTK("index %d->%d\n",skb->tc_index,index);
 298         switch (skb->protocol) {
 299                 case __constant_htons(ETH_P_IP):
 300                         ipv4_change_dsfield(skb->nh.iph,
 301                             p->mask[index],p->value[index]);
 302                         break;
 303                 case __constant_htons(ETH_P_IPV6):
 304                         ipv6_change_dsfield(skb->nh.ipv6h,
 305                             p->mask[index],p->value[index]);
 306                         break;
 307                 default:
 308                         /*
 309                          * Only complain if a change was actually attempted.
 310                          * This way, we can send non-IP traffic through dsmark
 311                          * and don't need yet another qdisc as a bypass.
 312                          */
 313                         if (p->mask[index] != 0xff || p->value[index])
 314                                 printk(KERN_WARNING "dsmark_dequeue: "
 315                                        "unsupported protocol %d\n",
 316                                        htons(skb->protocol));
 317                         break;
 318         };
 319         return skb;
 320 }
 321
 322
 323 static int dsmark_requeue(struct sk_buff *skb,struct Qdisc *sch)
 324 {
 325         int ret;
 326         struct dsmark_qdisc_data *p = PRIV(sch);
 327
 328         D2PRINTK("dsmark_requeue(skb %p,sch %p,[qdisc %p])\n",skb,sch,p);
 329         if ((ret = p->q->ops->requeue(skb, p->q)) == 0) {
 330                 sch->q.qlen++;
 331                 sch->qstats.requeues++;
 332                 return 0;
 333         }
 334         sch->qstats.drops++;
 335         return ret;
 336 }
 337
 338
 339 static unsigned int dsmark_drop(struct Qdisc *sch)
 340 {
 341         struct dsmark_qdisc_data *p = PRIV(sch);
 342         unsigned int len;
 343
 344         DPRINTK("dsmark_reset(sch %p,[qdisc %p])\n",sch,p);
 345         if (!p->q->ops->drop)
 346                 return 0;
 347         if (!(len = p->q->ops->drop(p->q)))
 348                 return 0;
 349         sch->q.qlen--;
 350         return len;
 351 }
 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
 404 static void dsmark_reset(struct Qdisc *sch)
 405 {
 406         struct dsmark_qdisc_data *p = PRIV(sch);
 407
 408         DPRINTK("dsmark_reset(sch %p,[qdisc %p])\n",sch,p);
 409         qdisc_reset(p->q);
 410         sch->q.qlen = 0;
 411 }
 412
 413
 414 static void dsmark_destroy(struct Qdisc *sch)
 415 {
 416         struct dsmark_qdisc_data *p = PRIV(sch);
 417         struct tcf_proto *tp;
 418
 419         DPRINTK("dsmark_destroy(sch %p,[qdisc %p])\n",sch,p);
 420         while (p->filter_list) {
 421                 tp = p->filter_list;
 422                 p->filter_list = tp->next;
 423                 tcf_destroy(tp);
 424         }
 425         qdisc_destroy(p->q);
 426         kfree(p->mask);
 427 }
 428
 429
 430 static int dsmark_dump_class(struct Qdisc *sch, unsigned long cl,
 431     struct sk_buff *skb, struct tcmsg *tcm)
 432 {
 433         struct dsmark_qdisc_data *p = PRIV(sch);
 434         unsigned char *b = skb->tail;
 435         struct rtattr *rta;
 436
 437         DPRINTK("dsmark_dump_class(sch %p,[qdisc %p],class %ld\n",sch,p,cl);
 438         if (!cl || cl > p->indices)
 439                 return -EINVAL;
 440         tcm->tcm_handle = TC_H_MAKE(TC_H_MAJ(sch->handle),cl-1);
 441         rta = (struct rtattr *) b;
 442         RTA_PUT(skb,TCA_OPTIONS,0,NULL);
 443         RTA_PUT(skb,TCA_DSMARK_MASK,1,&p->mask[cl-1]);
 444         RTA_PUT(skb,TCA_DSMARK_VALUE,1,&p->value[cl-1]);
 445         rta->rta_len = skb->tail-b;
 446         return skb->len;
 447
 448 rtattr_failure:
 449         skb_trim(skb,b-skb->data);
 450         return -1;
 451 }
 452
 453 static int dsmark_dump(struct Qdisc *sch, struct sk_buff *skb)
 454 {
 455         struct dsmark_qdisc_data *p = PRIV(sch);
 456         unsigned char *b = skb->tail;
 457         struct rtattr *rta;
 458
 459         rta = (struct rtattr *) b;
 460         RTA_PUT(skb,TCA_OPTIONS,0,NULL);
 461         RTA_PUT(skb,TCA_DSMARK_INDICES,sizeof(__u16),&p->indices);
 462         if (p->default_index != NO_DEFAULT_INDEX) {
 463                 __u16 tmp = p->default_index;
 464
 465                 RTA_PUT(skb,TCA_DSMARK_DEFAULT_INDEX, sizeof(__u16), &tmp);
 466         }
 467         if (p->set_tc_index)
 468                 RTA_PUT(skb, TCA_DSMARK_SET_TC_INDEX, 0, NULL);
 469         rta->rta_len = skb->tail-b;
 470         return skb->len;
 471
 472 rtattr_failure:
 473         skb_trim(skb,b-skb->data);
 474         return -1;
 475 }
 476
 477 static struct Qdisc_class_ops dsmark_class_ops = {
 478         .graft          =       dsmark_graft,
 479         .leaf           =       dsmark_leaf,
 480         .get            =       dsmark_get,
 481         .put            =       dsmark_put,
 482         .change         =       dsmark_change,
 483         .delete         =       dsmark_delete,
 484         .walk           =       dsmark_walk,
 485         .tcf_chain      =       dsmark_find_tcf,
 486         .bind_tcf       =       dsmark_bind_filter,
 487         .unbind_tcf     =       dsmark_put,
 488         .dump           =       dsmark_dump_class,
 489 };
 490
 491 static struct Qdisc_ops dsmark_qdisc_ops = {
 492         .next           =       NULL,
 493         .cl_ops         =       &dsmark_class_ops,
 494         .id             =       "dsmark",
 495         .priv_size      =       sizeof(struct dsmark_qdisc_data),
 496         .enqueue        =       dsmark_enqueue,
 497         .dequeue        =       dsmark_dequeue,
 498         .requeue        =       dsmark_requeue,
 499         .drop           =       dsmark_drop,
 500         .init           =       dsmark_init,
 501         .reset          =       dsmark_reset,
 502         .destroy        =       dsmark_destroy,
 503         .change         =       NULL,
 504         .dump           =       dsmark_dump,
 505         .owner          =       THIS_MODULE,
 506 };
 507
 508 static int __init dsmark_module_init(void)
 509 {
 510         return register_qdisc(&dsmark_qdisc_ops);
 511 }
 512 static void __exit dsmark_module_exit(void)
 513 {
 514         unregister_qdisc(&dsmark_qdisc_ops);
 515 }
 516 module_init(dsmark_module_init)
 517 module_exit(dsmark_module_exit)
 518 MODULE_LICENSE("GPL");