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 <asm/byteorder.h>
  18
  19
  20 #if 1 /* control */
  21 #define DPRINTK(format,args...) printk(KERN_DEBUG format,##args)
  22 #else
  23 #define DPRINTK(format,args...)
  24 #endif
  25
  26 #if 0 /* data */
  27 #define D2PRINTK(format,args...) printk(KERN_DEBUG format,##args)
  28 #else
  29 #define D2PRINTK(format,args...)
  30 #endif
  31
  32
  33 #define PRIV(sch) ((struct dsmark_qdisc_data *) (sch)->data)
  34
  35
  36 /*
  37  * classid      class           marking
  38  * -------      -----           -------
  39  *   n/a          0             n/a
  40  *   x:0          1             use entry [0]
  41  *   ...         ...            ...
  42  *   x:y y>0     y+1            use entry [y]
  43  *   ...         ...            ...
  44  * x:indices-1  indices         use entry [indices-1]
  45  *   ...         ...            ...
  46  *   x:y         y+1            use entry [y & (indices-1)]
  47  *   ...         ...            ...
  48  * 0xffff       0x10000         use entry [indices-1]
  49  */
  50
  51
  52 #define NO_DEFAULT_INDEX        (1 << 16)
  53
  54 struct dsmark_qdisc_data {
  55         struct Qdisc            *q;
  56         struct tcf_proto        *filter_list;
  57         __u8                    *mask;  /* "owns" the array */
  58         __u8                    *value;
  59         __u16                   indices;
  60         __u32                   default_index;  /* index range is 0...0xffff */
  61         int                     set_tc_index;
  62 };
  63
  64
  65 /* ------------------------- Class/flow operations ------------------------- */
  66
  67
  68 static int dsmark_graft(struct Qdisc *sch,unsigned long arg,
  69     struct Qdisc *new,struct Qdisc **old)
  70 {
  71         struct dsmark_qdisc_data *p = PRIV(sch);
  72
  73         DPRINTK("dsmark_graft(sch %p,[qdisc %p],new %p,old %p)\n",sch,p,new,
  74             old);
  75         if (!new)
  76                 new = &noop_qdisc;
  77         sch_tree_lock(sch);
  78         *old = xchg(&p->q,new);
  79         if (*old)
  80                 qdisc_reset(*old);
  81         sch->q.qlen = 0;
  82         sch_tree_unlock(sch); /* @@@ move up ? */
  83         return 0;
  84 }
  85
  86
  87 static struct Qdisc *dsmark_leaf(struct Qdisc *sch, unsigned long arg)
  88 {
  89         struct dsmark_qdisc_data *p = PRIV(sch);
  90
  91         return p->q;
  92 }
  93
  94
  95 static unsigned long dsmark_get(struct Qdisc *sch,u32 classid)
  96 {
  97         struct dsmark_qdisc_data *p __attribute__((unused)) = PRIV(sch);
  98
  99         DPRINTK("dsmark_get(sch %p,[qdisc %p],classid %x)\n",sch,p,classid);
 100         return TC_H_MIN(classid)+1;
 101 }
 102
 103
 104 static unsigned long dsmark_bind_filter(struct Qdisc *sch,
 105     unsigned long parent, u32 classid)
 106 {
 107         return dsmark_get(sch,classid);
 108 }
 109
 110
 111 static void dsmark_put(struct Qdisc *sch, unsigned long cl)
 112 {
 113 }
 114
 115
 116 static int dsmark_change(struct Qdisc *sch, u32 classid, u32 parent,
 117     struct rtattr **tca, unsigned long *arg)
 118 {
 119         struct dsmark_qdisc_data *p = PRIV(sch);
 120         struct rtattr *opt = tca[TCA_OPTIONS-1];
 121         struct rtattr *tb[TCA_DSMARK_MAX];
 122
 123         DPRINTK("dsmark_change(sch %p,[qdisc %p],classid %x,parent %x),"
 124             "arg 0x%lx\n",sch,p,classid,parent,*arg);
 125         if (*arg > p->indices)
 126                 return -ENOENT;
 127         if (!opt || rtattr_parse(tb, TCA_DSMARK_MAX, RTA_DATA(opt),
 128                                  RTA_PAYLOAD(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                         continue;
 167                 if (walker->count >= walker->skip) {
 168                         if (walker->fn(sch, i+1, walker) < 0) {
 169                                 walker->stop = 1;
 170                                 break;
 171                         }
 172                 }
 173                 walker->count++;
 174         }
 175 }
 176
 177
 178 static struct tcf_proto **dsmark_find_tcf(struct Qdisc *sch,unsigned long cl)
 179 {
 180         struct dsmark_qdisc_data *p = PRIV(sch);
 181
 182         return &p->filter_list;
 183 }
 184
 185
 186 /* --------------------------- Qdisc operations ---------------------------- */
 187
 188
 189 static int dsmark_enqueue(struct sk_buff *skb,struct Qdisc *sch)
 190 {
 191         struct dsmark_qdisc_data *p = PRIV(sch);
 192         struct tcf_result res;
 193         int result;
 194         int ret = NET_XMIT_POLICED;
 195
 196         D2PRINTK("dsmark_enqueue(skb %p,sch %p,[qdisc %p])\n",skb,sch,p);
 197         if (p->set_tc_index) {
 198                 /* FIXME: Safe with non-linear skbs? --RR */
 199                 switch (skb->protocol) {
 200                         case __constant_htons(ETH_P_IP):
 201                                 skb->tc_index = ipv4_get_dsfield(skb->nh.iph);
 202                                 break;
 203                         case __constant_htons(ETH_P_IPV6):
 204                                 skb->tc_index = ipv6_get_dsfield(skb->nh.ipv6h);
 205                                 break;
 206                         default:
 207                                 skb->tc_index = 0;
 208                                 break;
 209                 };
 210         }
 211         result = TC_POLICE_OK; /* be nice to gcc */
 212         if (TC_H_MAJ(skb->priority) == sch->handle) {
 213                 skb->tc_index = TC_H_MIN(skb->priority);
 214         } else {
 215                 result = tc_classify(skb,p->filter_list,&res);
 216                 D2PRINTK("result %d class 0x%04x\n",result,res.classid);
 217                 switch (result) {
 218 #ifdef CONFIG_NET_CLS_POLICE
 219                         case TC_POLICE_SHOT:
 220                                 kfree_skb(skb);
 221                                 break;
 222 #if 0
 223                         case TC_POLICE_RECLASSIFY:
 224                                 /* FIXME: what to do here ??? */
 225 #endif
 226 #endif
 227                         case TC_POLICE_OK:
 228                                 skb->tc_index = TC_H_MIN(res.classid);
 229                                 break;
 230                         case TC_POLICE_UNSPEC:
 231                                 /* fall through */
 232                         default:
 233                                 if (p->default_index != NO_DEFAULT_INDEX)
 234                                         skb->tc_index = p->default_index;
 235                                 break;
 236                 };
 237         }
 238         if (
 239 #ifdef CONFIG_NET_CLS_POLICE
 240             result == TC_POLICE_SHOT ||
 241 #endif
 242
 243             ((ret = p->q->enqueue(skb,p->q)) != 0)) {
 244                 sch->stats.drops++;
 245                 return ret;
 246         }
 247         sch->stats.bytes += skb->len;
 248         sch->stats.packets++;
 249         sch->q.qlen++;
 250         return ret;
 251 }
 252
 253
 254 static struct sk_buff *dsmark_dequeue(struct Qdisc *sch)
 255 {
 256         struct dsmark_qdisc_data *p = PRIV(sch);
 257         struct sk_buff *skb;
 258         int index;
 259
 260         D2PRINTK("dsmark_dequeue(sch %p,[qdisc %p])\n",sch,p);
 261         skb = p->q->ops->dequeue(p->q);
 262         if (!skb)
 263                 return NULL;
 264         sch->q.qlen--;
 265         index = skb->tc_index & (p->indices-1);
 266         D2PRINTK("index %d->%d\n",skb->tc_index,index);
 267         switch (skb->protocol) {
 268                 case __constant_htons(ETH_P_IP):
 269                         ipv4_change_dsfield(skb->nh.iph,
 270                             p->mask[index],p->value[index]);
 271                         break;
 272                 case __constant_htons(ETH_P_IPV6):
 273                         ipv6_change_dsfield(skb->nh.ipv6h,
 274                             p->mask[index],p->value[index]);
 275                         break;
 276                 default:
 277                         /*
 278                          * Only complain if a change was actually attempted.
 279                          * This way, we can send non-IP traffic through dsmark
 280                          * and don't need yet another qdisc as a bypass.
 281                          */
 282                         if (p->mask[index] != 0xff || p->value[index])
 283                                 printk(KERN_WARNING "dsmark_dequeue: "
 284                                        "unsupported protocol %d\n",
 285                                        htons(skb->protocol));
 286                         break;
 287         };
 288         return skb;
 289 }
 290
 291
 292 static int dsmark_requeue(struct sk_buff *skb,struct Qdisc *sch)
 293 {
 294         int ret;
 295         struct dsmark_qdisc_data *p = PRIV(sch);
 296
 297         D2PRINTK("dsmark_requeue(skb %p,sch %p,[qdisc %p])\n",skb,sch,p);
 298         if ((ret = p->q->ops->requeue(skb, p->q)) == 0) {
 299                 sch->q.qlen++;
 300                 return 0;
 301         }
 302         sch->stats.drops++;
 303         return ret;
 304 }
 305
 306
 307 static unsigned int dsmark_drop(struct Qdisc *sch)
 308 {
 309         struct dsmark_qdisc_data *p = PRIV(sch);
 310         unsigned int len;
 311
 312         DPRINTK("dsmark_reset(sch %p,[qdisc %p])\n",sch,p);
 313         if (!p->q->ops->drop)
 314                 return 0;
 315         if (!(len = p->q->ops->drop(p->q)))
 316                 return 0;
 317         sch->q.qlen--;
 318         return len;
 319 }
 320
 321
 322 int dsmark_init(struct Qdisc *sch,struct rtattr *opt)
 323 {
 324         struct dsmark_qdisc_data *p = PRIV(sch);
 325         struct rtattr *tb[TCA_DSMARK_MAX];
 326         __u16 tmp;
 327
 328         DPRINTK("dsmark_init(sch %p,[qdisc %p],opt %p)\n",sch,p,opt);
 329         if (!opt ||
 330             rtattr_parse(tb,TCA_DSMARK_MAX,RTA_DATA(opt),RTA_PAYLOAD(opt)) < 0 ||
 331             !tb[TCA_DSMARK_INDICES-1] ||
 332             RTA_PAYLOAD(tb[TCA_DSMARK_INDICES-1]) < sizeof(__u16))
 333                 return -EINVAL;
 334         memset(p,0,sizeof(*p));
 335         p->filter_list = NULL;
 336         p->indices = *(__u16 *) RTA_DATA(tb[TCA_DSMARK_INDICES-1]);
 337         if (!p->indices)
 338                 return -EINVAL;
 339         for (tmp = p->indices; tmp != 1; tmp >>= 1) {
 340                 if (tmp & 1)
 341                         return -EINVAL;
 342         }
 343         p->default_index = NO_DEFAULT_INDEX;
 344         if (tb[TCA_DSMARK_DEFAULT_INDEX-1]) {
 345                 if (RTA_PAYLOAD(tb[TCA_DSMARK_DEFAULT_INDEX-1]) < sizeof(__u16))
 346                         return -EINVAL;
 347                 p->default_index =
 348                     *(__u16 *) RTA_DATA(tb[TCA_DSMARK_DEFAULT_INDEX-1]);
 349         }
 350         p->set_tc_index = !!tb[TCA_DSMARK_SET_TC_INDEX-1];
 351         p->mask = kmalloc(p->indices*2,GFP_KERNEL);
 352         if (!p->mask)
 353                 return -ENOMEM;
 354         p->value = p->mask+p->indices;
 355         memset(p->mask,0xff,p->indices);
 356         memset(p->value,0,p->indices);
 357         if (!(p->q = qdisc_create_dflt(sch->dev, &pfifo_qdisc_ops)))
 358                 p->q = &noop_qdisc;
 359         DPRINTK("dsmark_init: qdisc %p\n",&p->q);
 360         return 0;
 361 }
 362
 363
 364 static void dsmark_reset(struct Qdisc *sch)
 365 {
 366         struct dsmark_qdisc_data *p = PRIV(sch);
 367
 368         DPRINTK("dsmark_reset(sch %p,[qdisc %p])\n",sch,p);
 369         qdisc_reset(p->q);
 370         sch->q.qlen = 0;
 371 }
 372
 373
 374 static void dsmark_destroy(struct Qdisc *sch)
 375 {
 376         struct dsmark_qdisc_data *p = PRIV(sch);
 377         struct tcf_proto *tp;
 378
 379         DPRINTK("dsmark_destroy(sch %p,[qdisc %p])\n",sch,p);
 380         while (p->filter_list) {
 381                 tp = p->filter_list;
 382                 p->filter_list = tp->next;
 383                 tcf_destroy(tp);
 384         }
 385         qdisc_destroy(p->q);
 386         p->q = &noop_qdisc;
 387         kfree(p->mask);
 388 }
 389
 390
 391 static int dsmark_dump_class(struct Qdisc *sch, unsigned long cl,
 392     struct sk_buff *skb, struct tcmsg *tcm)
 393 {
 394         struct dsmark_qdisc_data *p = PRIV(sch);
 395         unsigned char *b = skb->tail;
 396         struct rtattr *rta;
 397
 398         DPRINTK("dsmark_dump_class(sch %p,[qdisc %p],class %ld\n",sch,p,cl);
 399         if (!cl || cl > p->indices)
 400                 return -EINVAL;
 401         tcm->tcm_handle = TC_H_MAKE(TC_H_MAJ(sch->handle),cl-1);
 402         rta = (struct rtattr *) b;
 403         RTA_PUT(skb,TCA_OPTIONS,0,NULL);
 404         RTA_PUT(skb,TCA_DSMARK_MASK,1,&p->mask[cl-1]);
 405         RTA_PUT(skb,TCA_DSMARK_VALUE,1,&p->value[cl-1]);
 406         rta->rta_len = skb->tail-b;
 407         return skb->len;
 408
 409 rtattr_failure:
 410         skb_trim(skb,b-skb->data);
 411         return -1;
 412 }
 413
 414 static int dsmark_dump(struct Qdisc *sch, struct sk_buff *skb)
 415 {
 416         struct dsmark_qdisc_data *p = PRIV(sch);
 417         unsigned char *b = skb->tail;
 418         struct rtattr *rta;
 419
 420         rta = (struct rtattr *) b;
 421         RTA_PUT(skb,TCA_OPTIONS,0,NULL);
 422         RTA_PUT(skb,TCA_DSMARK_INDICES,sizeof(__u16),&p->indices);
 423         if (p->default_index != NO_DEFAULT_INDEX) {
 424                 __u16 tmp = p->default_index;
 425
 426                 RTA_PUT(skb,TCA_DSMARK_DEFAULT_INDEX, sizeof(__u16), &tmp);
 427         }
 428         if (p->set_tc_index)
 429                 RTA_PUT(skb, TCA_DSMARK_SET_TC_INDEX, 0, NULL);
 430         rta->rta_len = skb->tail-b;
 431         return skb->len;
 432
 433 rtattr_failure:
 434         skb_trim(skb,b-skb->data);
 435         return -1;
 436 }
 437
 438 static struct Qdisc_class_ops dsmark_class_ops = {
 439         .graft          =       dsmark_graft,
 440         .leaf           =       dsmark_leaf,
 441         .get            =       dsmark_get,
 442         .put            =       dsmark_put,
 443         .change         =       dsmark_change,
 444         .delete         =       dsmark_delete,
 445         .walk           =       dsmark_walk,
 446         .tcf_chain      =       dsmark_find_tcf,
 447         .bind_tcf       =       dsmark_bind_filter,
 448         .unbind_tcf     =       dsmark_put,
 449         .dump           =       dsmark_dump_class,
 450 };
 451
 452 static struct Qdisc_ops dsmark_qdisc_ops = {
 453         .next           =       NULL,
 454         .cl_ops         =       &dsmark_class_ops,
 455         .id             =       "dsmark",
 456         .priv_size      =       sizeof(struct dsmark_qdisc_data),
 457         .enqueue        =       dsmark_enqueue,
 458         .dequeue        =       dsmark_dequeue,
 459         .requeue        =       dsmark_requeue,
 460         .drop           =       dsmark_drop,
 461         .init           =       dsmark_init,
 462         .reset          =       dsmark_reset,
 463         .destroy        =       dsmark_destroy,
 464         .change         =       NULL,
 465         .dump           =       dsmark_dump,
 466         .owner          =       THIS_MODULE,
 467 };
 468
 469 static int __init dsmark_module_init(void)
 470 {
 471         return register_qdisc(&dsmark_qdisc_ops);
 472 }
 473 static void __exit dsmark_module_exit(void)
 474 {
 475         unregister_qdisc(&dsmark_qdisc_ops);
 476 }
 477 module_init(dsmark_module_init)
 478 module_exit(dsmark_module_exit)
 479 MODULE_LICENSE("GPL");