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 1 /* 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
  66 /* ------------------------- Class/flow operations ------------------------- */
  67
  68
  69 static int dsmark_graft(struct Qdisc *sch,unsigned long arg,
  70     struct Qdisc *new,struct Qdisc **old)
  71 {
  72         struct dsmark_qdisc_data *p = PRIV(sch);
  73
  74         DPRINTK("dsmark_graft(sch %p,[qdisc %p],new %p,old %p)\n",sch,p,new,
  75             old);
  76         if (!new)
  77                 new = &noop_qdisc;
  78         sch_tree_lock(sch);
  79         *old = xchg(&p->q,new);
  80         if (*old)
  81                 qdisc_reset(*old);
  82         sch->q.qlen = 0;
  83         sch_tree_unlock(sch); /* @@@ move up ? */
  84         return 0;
  85 }
  86
  87
  88 static struct Qdisc *dsmark_leaf(struct Qdisc *sch, unsigned long arg)
  89 {
  90         struct dsmark_qdisc_data *p = PRIV(sch);
  91
  92         return p->q;
  93 }
  94
  95
  96 static unsigned long dsmark_get(struct Qdisc *sch,u32 classid)
  97 {
  98         struct dsmark_qdisc_data *p __attribute__((unused)) = PRIV(sch);
  99
 100         DPRINTK("dsmark_get(sch %p,[qdisc %p],classid %x)\n",sch,p,classid);
 101         return TC_H_MIN(classid)+1;
 102 }
 103
 104
 105 static unsigned long dsmark_bind_filter(struct Qdisc *sch,
 106     unsigned long parent, u32 classid)
 107 {
 108         return dsmark_get(sch,classid);
 109 }
 110
 111
 112 static void dsmark_put(struct Qdisc *sch, unsigned long cl)
 113 {
 114 }
 115
 116
 117 static int dsmark_change(struct Qdisc *sch, u32 classid, u32 parent,
 118     struct rtattr **tca, unsigned long *arg)
 119 {
 120         struct dsmark_qdisc_data *p = PRIV(sch);
 121         struct rtattr *opt = tca[TCA_OPTIONS-1];
 122         struct rtattr *tb[TCA_DSMARK_MAX];
 123
 124         DPRINTK("dsmark_change(sch %p,[qdisc %p],classid %x,parent %x),"
 125             "arg 0x%lx\n",sch,p,classid,parent,*arg);
 126         if (*arg > p->indices)
 127                 return -ENOENT;
 128         if (!opt || rtattr_parse_nested(tb, TCA_DSMARK_MAX, opt))
 129                 return -EINVAL;
 130         if (tb[TCA_DSMARK_MASK-1]) {
 131                 if (!RTA_PAYLOAD(tb[TCA_DSMARK_MASK-1]))
 132                         return -EINVAL;
 133                 p->mask[*arg-1] = *(__u8 *) RTA_DATA(tb[TCA_DSMARK_MASK-1]);
 134         }
 135         if (tb[TCA_DSMARK_VALUE-1]) {
 136                 if (!RTA_PAYLOAD(tb[TCA_DSMARK_VALUE-1]))
 137                         return -EINVAL;
 138                 p->value[*arg-1] = *(__u8 *) RTA_DATA(tb[TCA_DSMARK_VALUE-1]);
 139         }
 140         return 0;
 141 }
 142
 143
 144 static int dsmark_delete(struct Qdisc *sch,unsigned long arg)
 145 {
 146         struct dsmark_qdisc_data *p = PRIV(sch);
 147
 148         if (!arg || arg > p->indices)
 149                 return -EINVAL;
 150         p->mask[arg-1] = 0xff;
 151         p->value[arg-1] = 0;
 152         return 0;
 153 }
 154
 155
 156 static void dsmark_walk(struct Qdisc *sch,struct qdisc_walker *walker)
 157 {
 158         struct dsmark_qdisc_data *p = PRIV(sch);
 159         int i;
 160
 161         DPRINTK("dsmark_walk(sch %p,[qdisc %p],walker %p)\n",sch,p,walker);
 162         if (walker->stop)
 163                 return;
 164         for (i = 0; i < p->indices; i++) {
 165                 if (p->mask[i] == 0xff && !p->value[i])
 166                         goto ignore;
 167                 if (walker->count >= walker->skip) {
 168                         if (walker->fn(sch, i+1, walker) < 0) {
 169                                 walker->stop = 1;
 170                                 break;
 171                         }
 172                 }
 173 ignore:
 174                 walker->count++;
 175         }
 176 }
 177
 178
 179 static struct tcf_proto **dsmark_find_tcf(struct Qdisc *sch,unsigned long cl)
 180 {
 181         struct dsmark_qdisc_data *p = PRIV(sch);
 182
 183         return &p->filter_list;
 184 }
 185
 186
 187 /* --------------------------- Qdisc operations ---------------------------- */
 188
 189
 190 static int dsmark_enqueue(struct sk_buff *skb,struct Qdisc *sch)
 191 {
 192         struct dsmark_qdisc_data *p = PRIV(sch);
 193         struct tcf_result res;
 194         int result;
 195         int ret = NET_XMIT_POLICED;
 196
 197         D2PRINTK("dsmark_enqueue(skb %p,sch %p,[qdisc %p])\n",skb,sch,p);
 198         if (p->set_tc_index) {
 199                 /* FIXME: Safe with non-linear skbs? --RR */
 200                 switch (skb->protocol) {
 201                         case __constant_htons(ETH_P_IP):
 202                                 skb->tc_index = ipv4_get_dsfield(skb->nh.iph)
 203                                         & ~INET_ECN_MASK;
 204                                 break;
 205                         case __constant_htons(ETH_P_IPV6):
 206                                 skb->tc_index = ipv6_get_dsfield(skb->nh.ipv6h)
 207                                         & ~INET_ECN_MASK;
 208                                 break;
 209                         default:
 210                                 skb->tc_index = 0;
 211                                 break;
 212                 };
 213         }
 214         result = TC_POLICE_OK; /* be nice to gcc */
 215         if (TC_H_MAJ(skb->priority) == sch->handle) {
 216                 skb->tc_index = TC_H_MIN(skb->priority);
 217         } else {
 218                 result = tc_classify(skb,p->filter_list,&res);
 219                 D2PRINTK("result %d class 0x%04x\n",result,res.classid);
 220                 switch (result) {
 221 #ifdef CONFIG_NET_CLS_POLICE
 222                         case TC_POLICE_SHOT:
 223                                 kfree_skb(skb);
 224                                 break;
 225 #if 0
 226                         case TC_POLICE_RECLASSIFY:
 227                                 /* FIXME: what to do here ??? */
 228 #endif
 229 #endif
 230                         case TC_POLICE_OK:
 231                                 skb->tc_index = TC_H_MIN(res.classid);
 232                                 break;
 233                         case TC_POLICE_UNSPEC:
 234                                 /* fall through */
 235                         default:
 236                                 if (p->default_index != NO_DEFAULT_INDEX)
 237                                         skb->tc_index = p->default_index;
 238                                 break;
 239                 };
 240         }
 241         if (
 242 #ifdef CONFIG_NET_CLS_POLICE
 243             result == TC_POLICE_SHOT ||
 244 #endif
 245
 246             ((ret = p->q->enqueue(skb,p->q)) != 0)) {
 247                 sch->qstats.drops++;
 248                 return ret;
 249         }
 250         sch->bstats.bytes += skb->len;
 251         sch->bstats.packets++;
 252         sch->q.qlen++;
 253         return ret;
 254 }
 255
 256
 257 static struct sk_buff *dsmark_dequeue(struct Qdisc *sch)
 258 {
 259         struct dsmark_qdisc_data *p = PRIV(sch);
 260         struct sk_buff *skb;
 261         int index;
 262
 263         D2PRINTK("dsmark_dequeue(sch %p,[qdisc %p])\n",sch,p);
 264         skb = p->q->ops->dequeue(p->q);
 265         if (!skb)
 266                 return NULL;
 267         sch->q.qlen--;
 268         index = skb->tc_index & (p->indices-1);
 269         D2PRINTK("index %d->%d\n",skb->tc_index,index);
 270         switch (skb->protocol) {
 271                 case __constant_htons(ETH_P_IP):
 272                         ipv4_change_dsfield(skb->nh.iph,
 273                             p->mask[index],p->value[index]);
 274                         break;
 275                 case __constant_htons(ETH_P_IPV6):
 276                         ipv6_change_dsfield(skb->nh.ipv6h,
 277                             p->mask[index],p->value[index]);
 278                         break;
 279                 default:
 280                         /*
 281                          * Only complain if a change was actually attempted.
 282                          * This way, we can send non-IP traffic through dsmark
 283                          * and don't need yet another qdisc as a bypass.
 284                          */
 285                         if (p->mask[index] != 0xff || p->value[index])
 286                                 printk(KERN_WARNING "dsmark_dequeue: "
 287                                        "unsupported protocol %d\n",
 288                                        htons(skb->protocol));
 289                         break;
 290         };
 291         return skb;
 292 }
 293
 294
 295 static int dsmark_requeue(struct sk_buff *skb,struct Qdisc *sch)
 296 {
 297         int ret;
 298         struct dsmark_qdisc_data *p = PRIV(sch);
 299
 300         D2PRINTK("dsmark_requeue(skb %p,sch %p,[qdisc %p])\n",skb,sch,p);
 301         if ((ret = p->q->ops->requeue(skb, p->q)) == 0) {
 302                 sch->q.qlen++;
 303                 sch->qstats.requeues++;
 304                 return 0;
 305         }
 306         sch->qstats.drops++;
 307         return ret;
 308 }
 309
 310
 311 static unsigned int dsmark_drop(struct Qdisc *sch)
 312 {
 313         struct dsmark_qdisc_data *p = PRIV(sch);
 314         unsigned int len;
 315
 316         DPRINTK("dsmark_reset(sch %p,[qdisc %p])\n",sch,p);
 317         if (!p->q->ops->drop)
 318                 return 0;
 319         if (!(len = p->q->ops->drop(p->q)))
 320                 return 0;
 321         sch->q.qlen--;
 322         return len;
 323 }
 324
 325
 326 static int dsmark_init(struct Qdisc *sch,struct rtattr *opt)
 327 {
 328         struct dsmark_qdisc_data *p = PRIV(sch);
 329         struct rtattr *tb[TCA_DSMARK_MAX];
 330         __u16 tmp;
 331
 332         DPRINTK("dsmark_init(sch %p,[qdisc %p],opt %p)\n",sch,p,opt);
 333         if (!opt ||
 334             rtattr_parse(tb,TCA_DSMARK_MAX,RTA_DATA(opt),RTA_PAYLOAD(opt)) < 0 ||
 335             !tb[TCA_DSMARK_INDICES-1] ||
 336             RTA_PAYLOAD(tb[TCA_DSMARK_INDICES-1]) < sizeof(__u16))
 337                 return -EINVAL;
 338         p->indices = *(__u16 *) RTA_DATA(tb[TCA_DSMARK_INDICES-1]);
 339         if (!p->indices)
 340                 return -EINVAL;
 341         for (tmp = p->indices; tmp != 1; tmp >>= 1) {
 342                 if (tmp & 1)
 343                         return -EINVAL;
 344         }
 345         p->default_index = NO_DEFAULT_INDEX;
 346         if (tb[TCA_DSMARK_DEFAULT_INDEX-1]) {
 347                 if (RTA_PAYLOAD(tb[TCA_DSMARK_DEFAULT_INDEX-1]) < sizeof(__u16))
 348                         return -EINVAL;
 349                 p->default_index =
 350                     *(__u16 *) RTA_DATA(tb[TCA_DSMARK_DEFAULT_INDEX-1]);
 351         }
 352         p->set_tc_index = !!tb[TCA_DSMARK_SET_TC_INDEX-1];
 353         p->mask = kmalloc(p->indices*2,GFP_KERNEL);
 354         if (!p->mask)
 355                 return -ENOMEM;
 356         p->value = p->mask+p->indices;
 357         memset(p->mask,0xff,p->indices);
 358         memset(p->value,0,p->indices);
 359         if (!(p->q = qdisc_create_dflt(sch->dev, &pfifo_qdisc_ops)))
 360                 p->q = &noop_qdisc;
 361         DPRINTK("dsmark_init: qdisc %p\n",&p->q);
 362         return 0;
 363 }
 364
 365
 366 static void dsmark_reset(struct Qdisc *sch)
 367 {
 368         struct dsmark_qdisc_data *p = PRIV(sch);
 369
 370         DPRINTK("dsmark_reset(sch %p,[qdisc %p])\n",sch,p);
 371         qdisc_reset(p->q);
 372         sch->q.qlen = 0;
 373 }
 374
 375
 376 static void dsmark_destroy(struct Qdisc *sch)
 377 {
 378         struct dsmark_qdisc_data *p = PRIV(sch);
 379         struct tcf_proto *tp;
 380
 381         DPRINTK("dsmark_destroy(sch %p,[qdisc %p])\n",sch,p);
 382         while (p->filter_list) {
 383                 tp = p->filter_list;
 384                 p->filter_list = tp->next;
 385                 tcf_destroy(tp);
 386         }
 387         qdisc_destroy(p->q);
 388         kfree(p->mask);
 389 }
 390
 391
 392 static int dsmark_dump_class(struct Qdisc *sch, unsigned long cl,
 393     struct sk_buff *skb, struct tcmsg *tcm)
 394 {
 395         struct dsmark_qdisc_data *p = PRIV(sch);
 396         unsigned char *b = skb->tail;
 397         struct rtattr *rta;
 398
 399         DPRINTK("dsmark_dump_class(sch %p,[qdisc %p],class %ld\n",sch,p,cl);
 400         if (!cl || cl > p->indices)
 401                 return -EINVAL;
 402         tcm->tcm_handle = TC_H_MAKE(TC_H_MAJ(sch->handle),cl-1);
 403         rta = (struct rtattr *) b;
 404         RTA_PUT(skb,TCA_OPTIONS,0,NULL);
 405         RTA_PUT(skb,TCA_DSMARK_MASK,1,&p->mask[cl-1]);
 406         RTA_PUT(skb,TCA_DSMARK_VALUE,1,&p->value[cl-1]);
 407         rta->rta_len = skb->tail-b;
 408         return skb->len;
 409
 410 rtattr_failure:
 411         skb_trim(skb,b-skb->data);
 412         return -1;
 413 }
 414
 415 static int dsmark_dump(struct Qdisc *sch, struct sk_buff *skb)
 416 {
 417         struct dsmark_qdisc_data *p = PRIV(sch);
 418         unsigned char *b = skb->tail;
 419         struct rtattr *rta;
 420
 421         rta = (struct rtattr *) b;
 422         RTA_PUT(skb,TCA_OPTIONS,0,NULL);
 423         RTA_PUT(skb,TCA_DSMARK_INDICES,sizeof(__u16),&p->indices);
 424         if (p->default_index != NO_DEFAULT_INDEX) {
 425                 __u16 tmp = p->default_index;
 426
 427                 RTA_PUT(skb,TCA_DSMARK_DEFAULT_INDEX, sizeof(__u16), &tmp);
 428         }
 429         if (p->set_tc_index)
 430                 RTA_PUT(skb, TCA_DSMARK_SET_TC_INDEX, 0, NULL);
 431         rta->rta_len = skb->tail-b;
 432         return skb->len;
 433
 434 rtattr_failure:
 435         skb_trim(skb,b-skb->data);
 436         return -1;
 437 }
 438
 439 static struct Qdisc_class_ops dsmark_class_ops = {
 440         .graft          =       dsmark_graft,
 441         .leaf           =       dsmark_leaf,
 442         .get            =       dsmark_get,
 443         .put            =       dsmark_put,
 444         .change         =       dsmark_change,
 445         .delete         =       dsmark_delete,
 446         .walk           =       dsmark_walk,
 447         .tcf_chain      =       dsmark_find_tcf,
 448         .bind_tcf       =       dsmark_bind_filter,
 449         .unbind_tcf     =       dsmark_put,
 450         .dump           =       dsmark_dump_class,
 451 };
 452
 453 static struct Qdisc_ops dsmark_qdisc_ops = {
 454         .next           =       NULL,
 455         .cl_ops         =       &dsmark_class_ops,
 456         .id             =       "dsmark",
 457         .priv_size      =       sizeof(struct dsmark_qdisc_data),
 458         .enqueue        =       dsmark_enqueue,
 459         .dequeue        =       dsmark_dequeue,
 460         .requeue        =       dsmark_requeue,
 461         .drop           =       dsmark_drop,
 462         .init           =       dsmark_init,
 463         .reset          =       dsmark_reset,
 464         .destroy        =       dsmark_destroy,
 465         .change         =       NULL,
 466         .dump           =       dsmark_dump,
 467         .owner          =       THIS_MODULE,
 468 };
 469
 470 static int __init dsmark_module_init(void)
 471 {
 472         return register_qdisc(&dsmark_qdisc_ops);
 473 }
 474 static void __exit dsmark_module_exit(void)
 475 {
 476         unregister_qdisc(&dsmark_qdisc_ops);
 477 }
 478 module_init(dsmark_module_init)
 479 module_exit(dsmark_module_exit)
 480 MODULE_LICENSE("GPL");