net/sched/cls_route.c

   1 /*
   2  * net/sched/cls_route.c        ROUTE4 classifier.
   3  *
   4  *              This program is free software; you can redistribute it and/or
   5  *              modify it under the terms of the GNU General Public License
   6  *              as published by the Free Software Foundation; either version
   7  *              2 of the License, or (at your option) any later version.
   8  *
   9  * Authors:     Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
  10  */
  11
  12 #include <linux/module.h>
  13 #include <linux/slab.h>
  14 #include <linux/types.h>
  15 #include <linux/kernel.h>
  16 #include <linux/string.h>
  17 #include <linux/errno.h>
  18 #include <linux/skbuff.h>
  19 #include <net/dst.h>
  20 #include <net/route.h>
  21 #include <net/netlink.h>
  22 #include <net/act_api.h>
  23 #include <net/pkt_cls.h>
  24
  25 /*
  26  * 1. For now we assume that route tags < 256.
  27  *    It allows to use direct table lookups, instead of hash tables.
  28  * 2. For now we assume that "from TAG" and "fromdev DEV" statements
  29  *    are mutually  exclusive.
  30  * 3. "to TAG from ANY" has higher priority, than "to ANY from XXX"
  31  */
  32
  33 struct route4_fastmap {
  34         struct route4_filter    *filter;
  35         u32                     id;
  36         int                     iif;
  37 };
  38
  39 struct route4_head {
  40         struct route4_fastmap   fastmap[16];
  41         struct route4_bucket    *table[256 + 1];
  42 };
  43
  44 struct route4_bucket {
  45         /* 16 FROM buckets + 16 IIF buckets + 1 wildcard bucket */
  46         struct route4_filter    *ht[16 + 16 + 1];
  47 };
  48
  49 struct route4_filter {
  50         struct route4_filter    *next;
  51         u32                     id;
  52         int                     iif;
  53
  54         struct tcf_result       res;
  55         struct tcf_exts         exts;
  56         u32                     handle;
  57         struct route4_bucket    *bkt;
  58 };
  59
  60 #define ROUTE4_FAILURE ((struct route4_filter *)(-1L))
  61
  62 static const struct tcf_ext_map route_ext_map = {
  63         .police = TCA_ROUTE4_POLICE,
  64         .action = TCA_ROUTE4_ACT
  65 };
  66
  67 static inline int route4_fastmap_hash(u32 id, int iif)
  68 {
  69         return id & 0xF;
  70 }
  71
  72 static void
  73 route4_reset_fastmap(struct Qdisc *q, struct route4_head *head, u32 id)
  74 {
  75         spinlock_t *root_lock = qdisc_root_sleeping_lock(q);
  76
  77         spin_lock_bh(root_lock);
  78         memset(head->fastmap, 0, sizeof(head->fastmap));
  79         spin_unlock_bh(root_lock);
  80 }
  81
  82 static void
  83 route4_set_fastmap(struct route4_head *head, u32 id, int iif,
  84                    struct route4_filter *f)
  85 {
  86         int h = route4_fastmap_hash(id, iif);
  87
  88         head->fastmap[h].id = id;
  89         head->fastmap[h].iif = iif;
  90         head->fastmap[h].filter = f;
  91 }
  92
  93 static inline int route4_hash_to(u32 id)
  94 {
  95         return id & 0xFF;
  96 }
  97
  98 static inline int route4_hash_from(u32 id)
  99 {
 100         return (id >> 16) & 0xF;
 101 }
 102
 103 static inline int route4_hash_iif(int iif)
 104 {
 105         return 16 + ((iif >> 16) & 0xF);
 106 }
 107
 108 static inline int route4_hash_wild(void)
 109 {
 110         return 32;
 111 }
 112
 113 #define ROUTE4_APPLY_RESULT()                                   \
 114 {                                                               \
 115         *res = f->res;                                          \
 116         if (tcf_exts_is_available(&f->exts)) {                  \
 117                 int r = tcf_exts_exec(skb, &f->exts, res);      \
 118                 if (r < 0) {                                    \
 119                         dont_cache = 1;                         \
 120                         continue;                               \
 121                 }                                               \
 122                 return r;                                       \
 123         } else if (!dont_cache)                                 \
 124                 route4_set_fastmap(head, id, iif, f);           \
 125         return 0;                                               \
 126 }
 127
 128 static int route4_classify(struct sk_buff *skb, const struct tcf_proto *tp,
 129                            struct tcf_result *res)
 130 {
 131         struct route4_head *head = (struct route4_head *)tp->root;
 132         struct dst_entry *dst;
 133         struct route4_bucket *b;
 134         struct route4_filter *f;
 135         u32 id, h;
 136         int iif, dont_cache = 0;
 137
 138         dst = skb_dst(skb);
 139         if (!dst)
 140                 goto failure;
 141
 142         id = dst->tclassid;
 143         if (head == NULL)
 144                 goto old_method;
 145
 146         iif = inet_iif(skb);
 147
 148         h = route4_fastmap_hash(id, iif);
 149         if (id == head->fastmap[h].id &&
 150             iif == head->fastmap[h].iif &&
 151             (f = head->fastmap[h].filter) != NULL) {
 152                 if (f == ROUTE4_FAILURE)
 153                         goto failure;
 154
 155                 *res = f->res;
 156                 return 0;
 157         }
 158
 159         h = route4_hash_to(id);
 160
 161 restart:
 162         b = head->table[h];
 163         if (b) {
 164                 for (f = b->ht[route4_hash_from(id)]; f; f = f->next)
 165                         if (f->id == id)
 166                                 ROUTE4_APPLY_RESULT();
 167
 168                 for (f = b->ht[route4_hash_iif(iif)]; f; f = f->next)
 169                         if (f->iif == iif)
 170                                 ROUTE4_APPLY_RESULT();
 171
 172                 for (f = b->ht[route4_hash_wild()]; f; f = f->next)
 173                         ROUTE4_APPLY_RESULT();
 174
 175         }
 176         if (h < 256) {
 177                 h = 256;
 178                 id &= ~0xFFFF;
 179                 goto restart;
 180         }
 181
 182         if (!dont_cache)
 183                 route4_set_fastmap(head, id, iif, ROUTE4_FAILURE);
 184 failure:
 185         return -1;
 186
 187 old_method:
 188         if (id && (TC_H_MAJ(id) == 0 ||
 189                    !(TC_H_MAJ(id^tp->q->handle)))) {
 190                 res->classid = id;
 191                 res->class = 0;
 192                 return 0;
 193         }
 194         return -1;
 195 }
 196
 197 static inline u32 to_hash(u32 id)
 198 {
 199         u32 h = id & 0xFF;
 200
 201         if (id & 0x8000)
 202                 h += 256;
 203         return h;
 204 }
 205
 206 static inline u32 from_hash(u32 id)
 207 {
 208         id &= 0xFFFF;
 209         if (id == 0xFFFF)
 210                 return 32;
 211         if (!(id & 0x8000)) {
 212                 if (id > 255)
 213                         return 256;
 214                 return id & 0xF;
 215         }
 216         return 16 + (id & 0xF);
 217 }
 218
 219 static unsigned long route4_get(struct tcf_proto *tp, u32 handle)
 220 {
 221         struct route4_head *head = (struct route4_head *)tp->root;
 222         struct route4_bucket *b;
 223         struct route4_filter *f;
 224         unsigned int h1, h2;
 225
 226         if (!head)
 227                 return 0;
 228
 229         h1 = to_hash(handle);
 230         if (h1 > 256)
 231                 return 0;
 232
 233         h2 = from_hash(handle >> 16);
 234         if (h2 > 32)
 235                 return 0;
 236
 237         b = head->table[h1];
 238         if (b) {
 239                 for (f = b->ht[h2]; f; f = f->next)
 240                         if (f->handle == handle)
 241                                 return (unsigned long)f;
 242         }
 243         return 0;
 244 }
 245
 246 static void route4_put(struct tcf_proto *tp, unsigned long f)
 247 {
 248 }
 249
 250 static int route4_init(struct tcf_proto *tp)
 251 {
 252         return 0;
 253 }
 254
 255 static void
 256 route4_delete_filter(struct tcf_proto *tp, struct route4_filter *f)
 257 {
 258         tcf_unbind_filter(tp, &f->res);
 259         tcf_exts_destroy(tp, &f->exts);
 260         kfree(f);
 261 }
 262
 263 static void route4_destroy(struct tcf_proto *tp)
 264 {
 265         struct route4_head *head = tp->root;
 266         int h1, h2;
 267
 268         if (head == NULL)
 269                 return;
 270
 271         for (h1 = 0; h1 <= 256; h1++) {
 272                 struct route4_bucket *b;
 273
 274                 b = head->table[h1];
 275                 if (b) {
 276                         for (h2 = 0; h2 <= 32; h2++) {
 277                                 struct route4_filter *f;
 278
 279                                 while ((f = b->ht[h2]) != NULL) {
 280                                         b->ht[h2] = f->next;
 281                                         route4_delete_filter(tp, f);
 282                                 }
 283                         }
 284                         kfree(b);
 285                 }
 286         }
 287         kfree(head);
 288 }
 289
 290 static int route4_delete(struct tcf_proto *tp, unsigned long arg)
 291 {
 292         struct route4_head *head = (struct route4_head *)tp->root;
 293         struct route4_filter **fp, *f = (struct route4_filter *)arg;
 294         unsigned int h = 0;
 295         struct route4_bucket *b;
 296         int i;
 297
 298         if (!head || !f)
 299                 return -EINVAL;
 300
 301         h = f->handle;
 302         b = f->bkt;
 303
 304         for (fp = &b->ht[from_hash(h >> 16)]; *fp; fp = &(*fp)->next) {
 305                 if (*fp == f) {
 306                         tcf_tree_lock(tp);
 307                         *fp = f->next;
 308                         tcf_tree_unlock(tp);
 309
 310                         route4_reset_fastmap(tp->q, head, f->id);
 311                         route4_delete_filter(tp, f);
 312
 313                         /* Strip tree */
 314
 315                         for (i = 0; i <= 32; i++)
 316                                 if (b->ht[i])
 317                                         return 0;
 318
 319                         /* OK, session has no flows */
 320                         tcf_tree_lock(tp);
 321                         head->table[to_hash(h)] = NULL;
 322                         tcf_tree_unlock(tp);
 323
 324                         kfree(b);
 325                         return 0;
 326                 }
 327         }
 328         return 0;
 329 }
 330
 331 static const struct nla_policy route4_policy[TCA_ROUTE4_MAX + 1] = {
 332         [TCA_ROUTE4_CLASSID]    = { .type = NLA_U32 },
 333         [TCA_ROUTE4_TO]         = { .type = NLA_U32 },
 334         [TCA_ROUTE4_FROM]       = { .type = NLA_U32 },
 335         [TCA_ROUTE4_IIF]        = { .type = NLA_U32 },
 336 };
 337
 338 static int route4_set_parms(struct net *net, struct tcf_proto *tp,
 339                             unsigned long base, struct route4_filter *f,
 340                             u32 handle, struct route4_head *head,
 341                             struct nlattr **tb, struct nlattr *est, int new)
 342 {
 343         int err;
 344         u32 id = 0, to = 0, nhandle = 0x8000;
 345         struct route4_filter *fp;
 346         unsigned int h1;
 347         struct route4_bucket *b;
 348         struct tcf_exts e;
 349
 350         err = tcf_exts_validate(net, tp, tb, est, &e, &route_ext_map);
 351         if (err < 0)
 352                 return err;
 353
 354         err = -EINVAL;
 355         if (tb[TCA_ROUTE4_TO]) {
 356                 if (new && handle & 0x8000)
 357                         goto errout;
 358                 to = nla_get_u32(tb[TCA_ROUTE4_TO]);
 359                 if (to > 0xFF)
 360                         goto errout;
 361                 nhandle = to;
 362         }
 363
 364         if (tb[TCA_ROUTE4_FROM]) {
 365                 if (tb[TCA_ROUTE4_IIF])
 366                         goto errout;
 367                 id = nla_get_u32(tb[TCA_ROUTE4_FROM]);
 368                 if (id > 0xFF)
 369                         goto errout;
 370                 nhandle |= id << 16;
 371         } else if (tb[TCA_ROUTE4_IIF]) {
 372                 id = nla_get_u32(tb[TCA_ROUTE4_IIF]);
 373                 if (id > 0x7FFF)
 374                         goto errout;
 375                 nhandle |= (id | 0x8000) << 16;
 376         } else
 377                 nhandle |= 0xFFFF << 16;
 378
 379         if (handle && new) {
 380                 nhandle |= handle & 0x7F00;
 381                 if (nhandle != handle)
 382                         goto errout;
 383         }
 384
 385         h1 = to_hash(nhandle);
 386         b = head->table[h1];
 387         if (!b) {
 388                 err = -ENOBUFS;
 389                 b = kzalloc(sizeof(struct route4_bucket), GFP_KERNEL);
 390                 if (b == NULL)
 391                         goto errout;
 392
 393                 tcf_tree_lock(tp);
 394                 head->table[h1] = b;
 395                 tcf_tree_unlock(tp);
 396         } else {
 397                 unsigned int h2 = from_hash(nhandle >> 16);
 398
 399                 err = -EEXIST;
 400                 for (fp = b->ht[h2]; fp; fp = fp->next)
 401                         if (fp->handle == f->handle)
 402                                 goto errout;
 403         }
 404
 405         tcf_tree_lock(tp);
 406         if (tb[TCA_ROUTE4_TO])
 407                 f->id = to;
 408
 409         if (tb[TCA_ROUTE4_FROM])
 410                 f->id = to | id<<16;
 411         else if (tb[TCA_ROUTE4_IIF])
 412                 f->iif = id;
 413
 414         f->handle = nhandle;
 415         f->bkt = b;
 416         tcf_tree_unlock(tp);
 417
 418         if (tb[TCA_ROUTE4_CLASSID]) {
 419                 f->res.classid = nla_get_u32(tb[TCA_ROUTE4_CLASSID]);
 420                 tcf_bind_filter(tp, &f->res, base);
 421         }
 422
 423         tcf_exts_change(tp, &f->exts, &e);
 424
 425         return 0;
 426 errout:
 427         tcf_exts_destroy(tp, &e);
 428         return err;
 429 }
 430
 431 static int route4_change(struct net *net, struct sk_buff *in_skb,
 432                        struct tcf_proto *tp, unsigned long base,
 433                        u32 handle,
 434                        struct nlattr **tca,
 435                        unsigned long *arg)
 436 {
 437         struct route4_head *head = tp->root;
 438         struct route4_filter *f, *f1, **fp;
 439         struct route4_bucket *b;
 440         struct nlattr *opt = tca[TCA_OPTIONS];
 441         struct nlattr *tb[TCA_ROUTE4_MAX + 1];
 442         unsigned int h, th;
 443         u32 old_handle = 0;
 444         int err;
 445
 446         if (opt == NULL)
 447                 return handle ? -EINVAL : 0;
 448
 449         err = nla_parse_nested(tb, TCA_ROUTE4_MAX, opt, route4_policy);
 450         if (err < 0)
 451                 return err;
 452
 453         f = (struct route4_filter *)*arg;
 454         if (f) {
 455                 if (f->handle != handle && handle)
 456                         return -EINVAL;
 457
 458                 if (f->bkt)
 459                         old_handle = f->handle;
 460
 461                 err = route4_set_parms(net, tp, base, f, handle, head, tb,
 462                         tca[TCA_RATE], 0);
 463                 if (err < 0)
 464                         return err;
 465
 466                 goto reinsert;
 467         }
 468
 469         err = -ENOBUFS;
 470         if (head == NULL) {
 471                 head = kzalloc(sizeof(struct route4_head), GFP_KERNEL);
 472                 if (head == NULL)
 473                         goto errout;
 474
 475                 tcf_tree_lock(tp);
 476                 tp->root = head;
 477                 tcf_tree_unlock(tp);
 478         }
 479
 480         f = kzalloc(sizeof(struct route4_filter), GFP_KERNEL);
 481         if (f == NULL)
 482                 goto errout;
 483
 484         err = route4_set_parms(net, tp, base, f, handle, head, tb,
 485                 tca[TCA_RATE], 1);
 486         if (err < 0)
 487                 goto errout;
 488
 489 reinsert:
 490         h = from_hash(f->handle >> 16);
 491         for (fp = &f->bkt->ht[h]; (f1 = *fp) != NULL; fp = &f1->next)
 492                 if (f->handle < f1->handle)
 493                         break;
 494
 495         f->next = f1;
 496         tcf_tree_lock(tp);
 497         *fp = f;
 498
 499         if (old_handle && f->handle != old_handle) {
 500                 th = to_hash(old_handle);
 501                 h = from_hash(old_handle >> 16);
 502                 b = head->table[th];
 503                 if (b) {
 504                         for (fp = &b->ht[h]; *fp; fp = &(*fp)->next) {
 505                                 if (*fp == f) {
 506                                         *fp = f->next;
 507                                         break;
 508                                 }
 509                         }
 510                 }
 511         }
 512         tcf_tree_unlock(tp);
 513
 514         route4_reset_fastmap(tp->q, head, f->id);
 515         *arg = (unsigned long)f;
 516         return 0;
 517
 518 errout:
 519         kfree(f);
 520         return err;
 521 }
 522
 523 static void route4_walk(struct tcf_proto *tp, struct tcf_walker *arg)
 524 {
 525         struct route4_head *head = tp->root;
 526         unsigned int h, h1;
 527
 528         if (head == NULL)
 529                 arg->stop = 1;
 530
 531         if (arg->stop)
 532                 return;
 533
 534         for (h = 0; h <= 256; h++) {
 535                 struct route4_bucket *b = head->table[h];
 536
 537                 if (b) {
 538                         for (h1 = 0; h1 <= 32; h1++) {
 539                                 struct route4_filter *f;
 540
 541                                 for (f = b->ht[h1]; f; f = f->next) {
 542                                         if (arg->count < arg->skip) {
 543                                                 arg->count++;
 544                                                 continue;
 545                                         }
 546                                         if (arg->fn(tp, (unsigned long)f, arg) < 0) {
 547                                                 arg->stop = 1;
 548                                                 return;
 549                                         }
 550                                         arg->count++;
 551                                 }
 552                         }
 553                 }
 554         }
 555 }
 556
 557 static int route4_dump(struct tcf_proto *tp, unsigned long fh,
 558                        struct sk_buff *skb, struct tcmsg *t)
 559 {
 560         struct route4_filter *f = (struct route4_filter *)fh;
 561         unsigned char *b = skb_tail_pointer(skb);
 562         struct nlattr *nest;
 563         u32 id;
 564
 565         if (f == NULL)
 566                 return skb->len;
 567
 568         t->tcm_handle = f->handle;
 569
 570         nest = nla_nest_start(skb, TCA_OPTIONS);
 571         if (nest == NULL)
 572                 goto nla_put_failure;
 573
 574         if (!(f->handle & 0x8000)) {
 575                 id = f->id & 0xFF;
 576                 if (nla_put_u32(skb, TCA_ROUTE4_TO, id))
 577                         goto nla_put_failure;
 578         }
 579         if (f->handle & 0x80000000) {
 580                 if ((f->handle >> 16) != 0xFFFF &&
 581                     nla_put_u32(skb, TCA_ROUTE4_IIF, f->iif))
 582                         goto nla_put_failure;
 583         } else {
 584                 id = f->id >> 16;
 585                 if (nla_put_u32(skb, TCA_ROUTE4_FROM, id))
 586                         goto nla_put_failure;
 587         }
 588         if (f->res.classid &&
 589             nla_put_u32(skb, TCA_ROUTE4_CLASSID, f->res.classid))
 590                 goto nla_put_failure;
 591
 592         if (tcf_exts_dump(skb, &f->exts, &route_ext_map) < 0)
 593                 goto nla_put_failure;
 594
 595         nla_nest_end(skb, nest);
 596
 597         if (tcf_exts_dump_stats(skb, &f->exts, &route_ext_map) < 0)
 598                 goto nla_put_failure;
 599
 600         return skb->len;
 601
 602 nla_put_failure:
 603         nlmsg_trim(skb, b);
 604         return -1;
 605 }
 606
 607 static struct tcf_proto_ops cls_route4_ops __read_mostly = {
 608         .kind           =       "route",
 609         .classify       =       route4_classify,
 610         .init           =       route4_init,
 611         .destroy        =       route4_destroy,
 612         .get            =       route4_get,
 613         .put            =       route4_put,
 614         .change         =       route4_change,
 615         .delete         =       route4_delete,
 616         .walk           =       route4_walk,
 617         .dump           =       route4_dump,
 618         .owner          =       THIS_MODULE,
 619 };
 620
 621 static int __init init_route4(void)
 622 {
 623         return register_tcf_proto_ops(&cls_route4_ops);
 624 }
 625
 626 static void __exit exit_route4(void)
 627 {
 628         unregister_tcf_proto_ops(&cls_route4_ops);
 629 }
 630
 631 module_init(init_route4)
 632 module_exit(exit_route4)
 633 MODULE_LICENSE("GPL");