net/sched/cls_flow.c

   1 /*
   2  * net/sched/cls_flow.c         Generic flow classifier
   3  *
   4  * Copyright (c) 2007, 2008 Patrick McHardy <kaber@trash.net>
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public License
   8  * as published by the Free Software Foundation; either version 2
   9  * of the License, or (at your option) any later version.
  10  */
  11
  12 #include <linux/kernel.h>
  13 #include <linux/init.h>
  14 #include <linux/list.h>
  15 #include <linux/jhash.h>
  16 #include <linux/random.h>
  17 #include <linux/pkt_cls.h>
  18 #include <linux/skbuff.h>
  19 #include <linux/in.h>
  20 #include <linux/ip.h>
  21 #include <linux/ipv6.h>
  22 #include <linux/if_vlan.h>
  23 #include <linux/slab.h>
  24 #include <linux/module.h>
  25 #include <net/inet_sock.h>
  26
  27 #include <net/pkt_cls.h>
  28 #include <net/ip.h>
  29 #include <net/route.h>
  30 #include <net/flow_dissector.h>
  31
  32 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
  33 #include <net/netfilter/nf_conntrack.h>
  34 #endif
  35
  36 struct flow_head {
  37         struct list_head        filters;
  38         struct rcu_head         rcu;
  39 };
  40
  41 struct flow_filter {
  42         struct list_head        list;
  43         struct tcf_exts         exts;
  44         struct tcf_ematch_tree  ematches;
  45         struct tcf_proto        *tp;
  46         struct timer_list       perturb_timer;
  47         u32                     perturb_period;
  48         u32                     handle;
  49
  50         u32                     nkeys;
  51         u32                     keymask;
  52         u32                     mode;
  53         u32                     mask;
  54         u32                     xor;
  55         u32                     rshift;
  56         u32                     addend;
  57         u32                     divisor;
  58         u32                     baseclass;
  59         u32                     hashrnd;
  60         struct rcu_head         rcu;
  61 };
  62
  63 static inline u32 addr_fold(void *addr)
  64 {
  65         unsigned long a = (unsigned long)addr;
  66
  67         return (a & 0xFFFFFFFF) ^ (BITS_PER_LONG > 32 ? a >> 32 : 0);
  68 }
  69
  70 static u32 flow_get_src(const struct sk_buff *skb, const struct flow_keys *flow)
  71 {
  72         __be32 src = flow_get_u32_src(flow);
  73
  74         if (src)
  75                 return ntohl(src);
  76
  77         return addr_fold(skb->sk);
  78 }
  79
  80 static u32 flow_get_dst(const struct sk_buff *skb, const struct flow_keys *flow)
  81 {
  82         __be32 dst = flow_get_u32_dst(flow);
  83
  84         if (dst)
  85                 return ntohl(dst);
  86
  87         return addr_fold(skb_dst(skb)) ^ (__force u16) tc_skb_protocol(skb);
  88 }
  89
  90 static u32 flow_get_proto(const struct sk_buff *skb,
  91                           const struct flow_keys *flow)
  92 {
  93         return flow->basic.ip_proto;
  94 }
  95
  96 static u32 flow_get_proto_src(const struct sk_buff *skb,
  97                               const struct flow_keys *flow)
  98 {
  99         if (flow->ports.ports)
 100                 return ntohs(flow->ports.src);
 101
 102         return addr_fold(skb->sk);
 103 }
 104
 105 static u32 flow_get_proto_dst(const struct sk_buff *skb,
 106                               const struct flow_keys *flow)
 107 {
 108         if (flow->ports.ports)
 109                 return ntohs(flow->ports.dst);
 110
 111         return addr_fold(skb_dst(skb)) ^ (__force u16) tc_skb_protocol(skb);
 112 }
 113
 114 static u32 flow_get_iif(const struct sk_buff *skb)
 115 {
 116         return skb->skb_iif;
 117 }
 118
 119 static u32 flow_get_priority(const struct sk_buff *skb)
 120 {
 121         return skb->priority;
 122 }
 123
 124 static u32 flow_get_mark(const struct sk_buff *skb)
 125 {
 126         return skb->mark;
 127 }
 128
 129 static u32 flow_get_nfct(const struct sk_buff *skb)
 130 {
 131 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
 132         return addr_fold(skb_nfct(skb));
 133 #else
 134         return 0;
 135 #endif
 136 }
 137
 138 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
 139 #define CTTUPLE(skb, member)                                            \
 140 ({                                                                      \
 141         enum ip_conntrack_info ctinfo;                                  \
 142         const struct nf_conn *ct = nf_ct_get(skb, &ctinfo);             \
 143         if (ct == NULL)                                                 \
 144                 goto fallback;                                          \
 145         ct->tuplehash[CTINFO2DIR(ctinfo)].tuple.member;                 \
 146 })
 147 #else
 148 #define CTTUPLE(skb, member)                                            \
 149 ({                                                                      \
 150         goto fallback;                                                  \
 151         0;                                                              \
 152 })
 153 #endif
 154
 155 static u32 flow_get_nfct_src(const struct sk_buff *skb,
 156                              const struct flow_keys *flow)
 157 {
 158         switch (tc_skb_protocol(skb)) {
 159         case htons(ETH_P_IP):
 160                 return ntohl(CTTUPLE(skb, src.u3.ip));
 161         case htons(ETH_P_IPV6):
 162                 return ntohl(CTTUPLE(skb, src.u3.ip6[3]));
 163         }
 164 fallback:
 165         return flow_get_src(skb, flow);
 166 }
 167
 168 static u32 flow_get_nfct_dst(const struct sk_buff *skb,
 169                              const struct flow_keys *flow)
 170 {
 171         switch (tc_skb_protocol(skb)) {
 172         case htons(ETH_P_IP):
 173                 return ntohl(CTTUPLE(skb, dst.u3.ip));
 174         case htons(ETH_P_IPV6):
 175                 return ntohl(CTTUPLE(skb, dst.u3.ip6[3]));
 176         }
 177 fallback:
 178         return flow_get_dst(skb, flow);
 179 }
 180
 181 static u32 flow_get_nfct_proto_src(const struct sk_buff *skb,
 182                                    const struct flow_keys *flow)
 183 {
 184         return ntohs(CTTUPLE(skb, src.u.all));
 185 fallback:
 186         return flow_get_proto_src(skb, flow);
 187 }
 188
 189 static u32 flow_get_nfct_proto_dst(const struct sk_buff *skb,
 190                                    const struct flow_keys *flow)
 191 {
 192         return ntohs(CTTUPLE(skb, dst.u.all));
 193 fallback:
 194         return flow_get_proto_dst(skb, flow);
 195 }
 196
 197 static u32 flow_get_rtclassid(const struct sk_buff *skb)
 198 {
 199 #ifdef CONFIG_IP_ROUTE_CLASSID
 200         if (skb_dst(skb))
 201                 return skb_dst(skb)->tclassid;
 202 #endif
 203         return 0;
 204 }
 205
 206 static u32 flow_get_skuid(const struct sk_buff *skb)
 207 {
 208         struct sock *sk = skb_to_full_sk(skb);
 209
 210         if (sk && sk->sk_socket && sk->sk_socket->file) {
 211                 kuid_t skuid = sk->sk_socket->file->f_cred->fsuid;
 212
 213                 return from_kuid(&init_user_ns, skuid);
 214         }
 215         return 0;
 216 }
 217
 218 static u32 flow_get_skgid(const struct sk_buff *skb)
 219 {
 220         struct sock *sk = skb_to_full_sk(skb);
 221
 222         if (sk && sk->sk_socket && sk->sk_socket->file) {
 223                 kgid_t skgid = sk->sk_socket->file->f_cred->fsgid;
 224
 225                 return from_kgid(&init_user_ns, skgid);
 226         }
 227         return 0;
 228 }
 229
 230 static u32 flow_get_vlan_tag(const struct sk_buff *skb)
 231 {
 232         u16 uninitialized_var(tag);
 233
 234         if (vlan_get_tag(skb, &tag) < 0)
 235                 return 0;
 236         return tag & VLAN_VID_MASK;
 237 }
 238
 239 static u32 flow_get_rxhash(struct sk_buff *skb)
 240 {
 241         return skb_get_hash(skb);
 242 }
 243
 244 static u32 flow_key_get(struct sk_buff *skb, int key, struct flow_keys *flow)
 245 {
 246         switch (key) {
 247         case FLOW_KEY_SRC:
 248                 return flow_get_src(skb, flow);
 249         case FLOW_KEY_DST:
 250                 return flow_get_dst(skb, flow);
 251         case FLOW_KEY_PROTO:
 252                 return flow_get_proto(skb, flow);
 253         case FLOW_KEY_PROTO_SRC:
 254                 return flow_get_proto_src(skb, flow);
 255         case FLOW_KEY_PROTO_DST:
 256                 return flow_get_proto_dst(skb, flow);
 257         case FLOW_KEY_IIF:
 258                 return flow_get_iif(skb);
 259         case FLOW_KEY_PRIORITY:
 260                 return flow_get_priority(skb);
 261         case FLOW_KEY_MARK:
 262                 return flow_get_mark(skb);
 263         case FLOW_KEY_NFCT:
 264                 return flow_get_nfct(skb);
 265         case FLOW_KEY_NFCT_SRC:
 266                 return flow_get_nfct_src(skb, flow);
 267         case FLOW_KEY_NFCT_DST:
 268                 return flow_get_nfct_dst(skb, flow);
 269         case FLOW_KEY_NFCT_PROTO_SRC:
 270                 return flow_get_nfct_proto_src(skb, flow);
 271         case FLOW_KEY_NFCT_PROTO_DST:
 272                 return flow_get_nfct_proto_dst(skb, flow);
 273         case FLOW_KEY_RTCLASSID:
 274                 return flow_get_rtclassid(skb);
 275         case FLOW_KEY_SKUID:
 276                 return flow_get_skuid(skb);
 277         case FLOW_KEY_SKGID:
 278                 return flow_get_skgid(skb);
 279         case FLOW_KEY_VLAN_TAG:
 280                 return flow_get_vlan_tag(skb);
 281         case FLOW_KEY_RXHASH:
 282                 return flow_get_rxhash(skb);
 283         default:
 284                 WARN_ON(1);
 285                 return 0;
 286         }
 287 }
 288
 289 #define FLOW_KEYS_NEEDED ((1 << FLOW_KEY_SRC) |                 \
 290                           (1 << FLOW_KEY_DST) |                 \
 291                           (1 << FLOW_KEY_PROTO) |               \
 292                           (1 << FLOW_KEY_PROTO_SRC) |           \
 293                           (1 << FLOW_KEY_PROTO_DST) |           \
 294                           (1 << FLOW_KEY_NFCT_SRC) |            \
 295                           (1 << FLOW_KEY_NFCT_DST) |            \
 296                           (1 << FLOW_KEY_NFCT_PROTO_SRC) |      \
 297                           (1 << FLOW_KEY_NFCT_PROTO_DST))
 298
 299 static int flow_classify(struct sk_buff *skb, const struct tcf_proto *tp,
 300                          struct tcf_result *res)
 301 {
 302         struct flow_head *head = rcu_dereference_bh(tp->root);
 303         struct flow_filter *f;
 304         u32 keymask;
 305         u32 classid;
 306         unsigned int n, key;
 307         int r;
 308
 309         list_for_each_entry_rcu(f, &head->filters, list) {
 310                 u32 keys[FLOW_KEY_MAX + 1];
 311                 struct flow_keys flow_keys;
 312
 313                 if (!tcf_em_tree_match(skb, &f->ematches, NULL))
 314                         continue;
 315
 316                 keymask = f->keymask;
 317                 if (keymask & FLOW_KEYS_NEEDED)
 318                         skb_flow_dissect_flow_keys(skb, &flow_keys, 0);
 319
 320                 for (n = 0; n < f->nkeys; n++) {
 321                         key = ffs(keymask) - 1;
 322                         keymask &= ~(1 << key);
 323                         keys[n] = flow_key_get(skb, key, &flow_keys);
 324                 }
 325
 326                 if (f->mode == FLOW_MODE_HASH)
 327                         classid = jhash2(keys, f->nkeys, f->hashrnd);
 328                 else {
 329                         classid = keys[0];
 330                         classid = (classid & f->mask) ^ f->xor;
 331                         classid = (classid >> f->rshift) + f->addend;
 332                 }
 333
 334                 if (f->divisor)
 335                         classid %= f->divisor;
 336
 337                 res->class   = 0;
 338                 res->classid = TC_H_MAKE(f->baseclass, f->baseclass + classid);
 339
 340                 r = tcf_exts_exec(skb, &f->exts, res);
 341                 if (r < 0)
 342                         continue;
 343                 return r;
 344         }
 345         return -1;
 346 }
 347
 348 static void flow_perturbation(unsigned long arg)
 349 {
 350         struct flow_filter *f = (struct flow_filter *)arg;
 351
 352         get_random_bytes(&f->hashrnd, 4);
 353         if (f->perturb_period)
 354                 mod_timer(&f->perturb_timer, jiffies + f->perturb_period);
 355 }
 356
 357 static const struct nla_policy flow_policy[TCA_FLOW_MAX + 1] = {
 358         [TCA_FLOW_KEYS]         = { .type = NLA_U32 },
 359         [TCA_FLOW_MODE]         = { .type = NLA_U32 },
 360         [TCA_FLOW_BASECLASS]    = { .type = NLA_U32 },
 361         [TCA_FLOW_RSHIFT]       = { .type = NLA_U32 },
 362         [TCA_FLOW_ADDEND]       = { .type = NLA_U32 },
 363         [TCA_FLOW_MASK]         = { .type = NLA_U32 },
 364         [TCA_FLOW_XOR]          = { .type = NLA_U32 },
 365         [TCA_FLOW_DIVISOR]      = { .type = NLA_U32 },
 366         [TCA_FLOW_ACT]          = { .type = NLA_NESTED },
 367         [TCA_FLOW_POLICE]       = { .type = NLA_NESTED },
 368         [TCA_FLOW_EMATCHES]     = { .type = NLA_NESTED },
 369         [TCA_FLOW_PERTURB]      = { .type = NLA_U32 },
 370 };
 371
 372 static void flow_destroy_filter(struct rcu_head *head)
 373 {
 374         struct flow_filter *f = container_of(head, struct flow_filter, rcu);
 375
 376         del_timer_sync(&f->perturb_timer);
 377         tcf_exts_destroy(&f->exts);
 378         tcf_em_tree_destroy(&f->ematches);
 379         kfree(f);
 380 }
 381
 382 static int flow_change(struct net *net, struct sk_buff *in_skb,
 383                        struct tcf_proto *tp, unsigned long base,
 384                        u32 handle, struct nlattr **tca,
 385                        void **arg, bool ovr)
 386 {
 387         struct flow_head *head = rtnl_dereference(tp->root);
 388         struct flow_filter *fold, *fnew;
 389         struct nlattr *opt = tca[TCA_OPTIONS];
 390         struct nlattr *tb[TCA_FLOW_MAX + 1];
 391         unsigned int nkeys = 0;
 392         unsigned int perturb_period = 0;
 393         u32 baseclass = 0;
 394         u32 keymask = 0;
 395         u32 mode;
 396         int err;
 397
 398         if (opt == NULL)
 399                 return -EINVAL;
 400
 401         err = nla_parse_nested(tb, TCA_FLOW_MAX, opt, flow_policy, NULL);
 402         if (err < 0)
 403                 return err;
 404
 405         if (tb[TCA_FLOW_BASECLASS]) {
 406                 baseclass = nla_get_u32(tb[TCA_FLOW_BASECLASS]);
 407                 if (TC_H_MIN(baseclass) == 0)
 408                         return -EINVAL;
 409         }
 410
 411         if (tb[TCA_FLOW_KEYS]) {
 412                 keymask = nla_get_u32(tb[TCA_FLOW_KEYS]);
 413
 414                 nkeys = hweight32(keymask);
 415                 if (nkeys == 0)
 416                         return -EINVAL;
 417
 418                 if (fls(keymask) - 1 > FLOW_KEY_MAX)
 419                         return -EOPNOTSUPP;
 420
 421                 if ((keymask & (FLOW_KEY_SKUID|FLOW_KEY_SKGID)) &&
 422                     sk_user_ns(NETLINK_CB(in_skb).sk) != &init_user_ns)
 423                         return -EOPNOTSUPP;
 424         }
 425
 426         fnew = kzalloc(sizeof(*fnew), GFP_KERNEL);
 427         if (!fnew)
 428                 return -ENOBUFS;
 429
 430         err = tcf_em_tree_validate(tp, tb[TCA_FLOW_EMATCHES], &fnew->ematches);
 431         if (err < 0)
 432                 goto err1;
 433
 434         err = tcf_exts_init(&fnew->exts, TCA_FLOW_ACT, TCA_FLOW_POLICE);
 435         if (err < 0)
 436                 goto err2;
 437
 438         err = tcf_exts_validate(net, tp, tb, tca[TCA_RATE], &fnew->exts, ovr);
 439         if (err < 0)
 440                 goto err2;
 441
 442         fold = *arg;
 443         if (fold) {
 444                 err = -EINVAL;
 445                 if (fold->handle != handle && handle)
 446                         goto err2;
 447
 448                 /* Copy fold into fnew */
 449                 fnew->tp = fold->tp;
 450                 fnew->handle = fold->handle;
 451                 fnew->nkeys = fold->nkeys;
 452                 fnew->keymask = fold->keymask;
 453                 fnew->mode = fold->mode;
 454                 fnew->mask = fold->mask;
 455                 fnew->xor = fold->xor;
 456                 fnew->rshift = fold->rshift;
 457                 fnew->addend = fold->addend;
 458                 fnew->divisor = fold->divisor;
 459                 fnew->baseclass = fold->baseclass;
 460                 fnew->hashrnd = fold->hashrnd;
 461
 462                 mode = fold->mode;
 463                 if (tb[TCA_FLOW_MODE])
 464                         mode = nla_get_u32(tb[TCA_FLOW_MODE]);
 465                 if (mode != FLOW_MODE_HASH && nkeys > 1)
 466                         goto err2;
 467
 468                 if (mode == FLOW_MODE_HASH)
 469                         perturb_period = fold->perturb_period;
 470                 if (tb[TCA_FLOW_PERTURB]) {
 471                         if (mode != FLOW_MODE_HASH)
 472                                 goto err2;
 473                         perturb_period = nla_get_u32(tb[TCA_FLOW_PERTURB]) * HZ;
 474                 }
 475         } else {
 476                 err = -EINVAL;
 477                 if (!handle)
 478                         goto err2;
 479                 if (!tb[TCA_FLOW_KEYS])
 480                         goto err2;
 481
 482                 mode = FLOW_MODE_MAP;
 483                 if (tb[TCA_FLOW_MODE])
 484                         mode = nla_get_u32(tb[TCA_FLOW_MODE]);
 485                 if (mode != FLOW_MODE_HASH && nkeys > 1)
 486                         goto err2;
 487
 488                 if (tb[TCA_FLOW_PERTURB]) {
 489                         if (mode != FLOW_MODE_HASH)
 490                                 goto err2;
 491                         perturb_period = nla_get_u32(tb[TCA_FLOW_PERTURB]) * HZ;
 492                 }
 493
 494                 if (TC_H_MAJ(baseclass) == 0)
 495                         baseclass = TC_H_MAKE(tp->q->handle, baseclass);
 496                 if (TC_H_MIN(baseclass) == 0)
 497                         baseclass = TC_H_MAKE(baseclass, 1);
 498
 499                 fnew->handle = handle;
 500                 fnew->mask  = ~0U;
 501                 fnew->tp = tp;
 502                 get_random_bytes(&fnew->hashrnd, 4);
 503         }
 504
 505         setup_deferrable_timer(&fnew->perturb_timer, flow_perturbation,
 506                                (unsigned long)fnew);
 507
 508         netif_keep_dst(qdisc_dev(tp->q));
 509
 510         if (tb[TCA_FLOW_KEYS]) {
 511                 fnew->keymask = keymask;
 512                 fnew->nkeys   = nkeys;
 513         }
 514
 515         fnew->mode = mode;
 516
 517         if (tb[TCA_FLOW_MASK])
 518                 fnew->mask = nla_get_u32(tb[TCA_FLOW_MASK]);
 519         if (tb[TCA_FLOW_XOR])
 520                 fnew->xor = nla_get_u32(tb[TCA_FLOW_XOR]);
 521         if (tb[TCA_FLOW_RSHIFT])
 522                 fnew->rshift = nla_get_u32(tb[TCA_FLOW_RSHIFT]);
 523         if (tb[TCA_FLOW_ADDEND])
 524                 fnew->addend = nla_get_u32(tb[TCA_FLOW_ADDEND]);
 525
 526         if (tb[TCA_FLOW_DIVISOR])
 527                 fnew->divisor = nla_get_u32(tb[TCA_FLOW_DIVISOR]);
 528         if (baseclass)
 529                 fnew->baseclass = baseclass;
 530
 531         fnew->perturb_period = perturb_period;
 532         if (perturb_period)
 533                 mod_timer(&fnew->perturb_timer, jiffies + perturb_period);
 534
 535         if (!*arg)
 536                 list_add_tail_rcu(&fnew->list, &head->filters);
 537         else
 538                 list_replace_rcu(&fold->list, &fnew->list);
 539
 540         *arg = fnew;
 541
 542         if (fold)
 543                 call_rcu(&fold->rcu, flow_destroy_filter);
 544         return 0;
 545
 546 err2:
 547         tcf_exts_destroy(&fnew->exts);
 548         tcf_em_tree_destroy(&fnew->ematches);
 549 err1:
 550         kfree(fnew);
 551         return err;
 552 }
 553
 554 static int flow_delete(struct tcf_proto *tp, void *arg, bool *last)
 555 {
 556         struct flow_head *head = rtnl_dereference(tp->root);
 557         struct flow_filter *f = arg;
 558
 559         list_del_rcu(&f->list);
 560         call_rcu(&f->rcu, flow_destroy_filter);
 561         *last = list_empty(&head->filters);
 562         return 0;
 563 }
 564
 565 static int flow_init(struct tcf_proto *tp)
 566 {
 567         struct flow_head *head;
 568
 569         head = kzalloc(sizeof(*head), GFP_KERNEL);
 570         if (head == NULL)
 571                 return -ENOBUFS;
 572         INIT_LIST_HEAD(&head->filters);
 573         rcu_assign_pointer(tp->root, head);
 574         return 0;
 575 }
 576
 577 static void flow_destroy(struct tcf_proto *tp)
 578 {
 579         struct flow_head *head = rtnl_dereference(tp->root);
 580         struct flow_filter *f, *next;
 581
 582         list_for_each_entry_safe(f, next, &head->filters, list) {
 583                 list_del_rcu(&f->list);
 584                 call_rcu(&f->rcu, flow_destroy_filter);
 585         }
 586         kfree_rcu(head, rcu);
 587 }
 588
 589 static void *flow_get(struct tcf_proto *tp, u32 handle)
 590 {
 591         struct flow_head *head = rtnl_dereference(tp->root);
 592         struct flow_filter *f;
 593
 594         list_for_each_entry(f, &head->filters, list)
 595                 if (f->handle == handle)
 596                         return f;
 597         return NULL;
 598 }
 599
 600 static int flow_dump(struct net *net, struct tcf_proto *tp, void *fh,
 601                      struct sk_buff *skb, struct tcmsg *t)
 602 {
 603         struct flow_filter *f = fh;
 604         struct nlattr *nest;
 605
 606         if (f == NULL)
 607                 return skb->len;
 608
 609         t->tcm_handle = f->handle;
 610
 611         nest = nla_nest_start(skb, TCA_OPTIONS);
 612         if (nest == NULL)
 613                 goto nla_put_failure;
 614
 615         if (nla_put_u32(skb, TCA_FLOW_KEYS, f->keymask) ||
 616             nla_put_u32(skb, TCA_FLOW_MODE, f->mode))
 617                 goto nla_put_failure;
 618
 619         if (f->mask != ~0 || f->xor != 0) {
 620                 if (nla_put_u32(skb, TCA_FLOW_MASK, f->mask) ||
 621                     nla_put_u32(skb, TCA_FLOW_XOR, f->xor))
 622                         goto nla_put_failure;
 623         }
 624         if (f->rshift &&
 625             nla_put_u32(skb, TCA_FLOW_RSHIFT, f->rshift))
 626                 goto nla_put_failure;
 627         if (f->addend &&
 628             nla_put_u32(skb, TCA_FLOW_ADDEND, f->addend))
 629                 goto nla_put_failure;
 630
 631         if (f->divisor &&
 632             nla_put_u32(skb, TCA_FLOW_DIVISOR, f->divisor))
 633                 goto nla_put_failure;
 634         if (f->baseclass &&
 635             nla_put_u32(skb, TCA_FLOW_BASECLASS, f->baseclass))
 636                 goto nla_put_failure;
 637
 638         if (f->perturb_period &&
 639             nla_put_u32(skb, TCA_FLOW_PERTURB, f->perturb_period / HZ))
 640                 goto nla_put_failure;
 641
 642         if (tcf_exts_dump(skb, &f->exts) < 0)
 643                 goto nla_put_failure;
 644 #ifdef CONFIG_NET_EMATCH
 645         if (f->ematches.hdr.nmatches &&
 646             tcf_em_tree_dump(skb, &f->ematches, TCA_FLOW_EMATCHES) < 0)
 647                 goto nla_put_failure;
 648 #endif
 649         nla_nest_end(skb, nest);
 650
 651         if (tcf_exts_dump_stats(skb, &f->exts) < 0)
 652                 goto nla_put_failure;
 653
 654         return skb->len;
 655
 656 nla_put_failure:
 657         nla_nest_cancel(skb, nest);
 658         return -1;
 659 }
 660
 661 static void flow_walk(struct tcf_proto *tp, struct tcf_walker *arg)
 662 {
 663         struct flow_head *head = rtnl_dereference(tp->root);
 664         struct flow_filter *f;
 665
 666         list_for_each_entry(f, &head->filters, list) {
 667                 if (arg->count < arg->skip)
 668                         goto skip;
 669                 if (arg->fn(tp, f, arg) < 0) {
 670                         arg->stop = 1;
 671                         break;
 672                 }
 673 skip:
 674                 arg->count++;
 675         }
 676 }
 677
 678 static struct tcf_proto_ops cls_flow_ops __read_mostly = {
 679         .kind           = "flow",
 680         .classify       = flow_classify,
 681         .init           = flow_init,
 682         .destroy        = flow_destroy,
 683         .change         = flow_change,
 684         .delete         = flow_delete,
 685         .get            = flow_get,
 686         .dump           = flow_dump,
 687         .walk           = flow_walk,
 688         .owner          = THIS_MODULE,
 689 };
 690
 691 static int __init cls_flow_init(void)
 692 {
 693         return register_tcf_proto_ops(&cls_flow_ops);
 694 }
 695
 696 static void __exit cls_flow_exit(void)
 697 {
 698         unregister_tcf_proto_ops(&cls_flow_ops);
 699 }
 700
 701 module_init(cls_flow_init);
 702 module_exit(cls_flow_exit);
 703
 704 MODULE_LICENSE("GPL");
 705 MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
 706 MODULE_DESCRIPTION("TC flow classifier");