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