kernel/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
  26 #include <net/pkt_cls.h>
  27 #include <net/ip.h>
  28 #include <net/route.h>
  29 #include <net/flow_keys.h>
  30
  31 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
  32 #include <net/netfilter/nf_conntrack.h>
  33 #endif
  34
  35 struct flow_head {
  36         struct list_head        filters;
  37         struct rcu_head         rcu;
  38 };
  39
  40 struct flow_filter {
  41         struct list_head        list;
  42         struct tcf_exts         exts;
  43         struct tcf_ematch_tree  ematches;
  44         struct tcf_proto        *tp;
  45         struct timer_list       perturb_timer;
  46         u32                     perturb_period;
  47         u32                     handle;
  48
  49         u32                     nkeys;
  50         u32                     keymask;
  51         u32                     mode;
  52         u32                     mask;
  53         u32                     xor;
  54         u32                     rshift;
  55         u32                     addend;
  56         u32                     divisor;
  57         u32                     baseclass;
  58         u32                     hashrnd;
  59         struct rcu_head         rcu;
  60 };
  61
  62 static inline u32 addr_fold(void *addr)
  63 {
  64         unsigned long a = (unsigned long)addr;
  65
  66         return (a & 0xFFFFFFFF) ^ (BITS_PER_LONG > 32 ? a >> 32 : 0);
  67 }
  68
  69 static u32 flow_get_src(const struct sk_buff *skb, const struct flow_keys *flow)
  70 {
  71         if (flow->src)
  72                 return ntohl(flow->src);
  73         return addr_fold(skb->sk);
  74 }
  75
  76 static u32 flow_get_dst(const struct sk_buff *skb, const struct flow_keys *flow)
  77 {
  78         if (flow->dst)
  79                 return ntohl(flow->dst);
  80         return addr_fold(skb_dst(skb)) ^ (__force u16) tc_skb_protocol(skb);
  81 }
  82
  83 static u32 flow_get_proto(const struct sk_buff *skb, const struct flow_keys *flow)
  84 {
  85         return flow->ip_proto;
  86 }
  87
  88 static u32 flow_get_proto_src(const struct sk_buff *skb, const struct flow_keys *flow)
  89 {
  90         if (flow->ports)
  91                 return ntohs(flow->port16[0]);
  92
  93         return addr_fold(skb->sk);
  94 }
  95
  96 static u32 flow_get_proto_dst(const struct sk_buff *skb, const struct flow_keys *flow)
  97 {
  98         if (flow->ports)
  99                 return ntohs(flow->port16[1]);
 100
 101         return addr_fold(skb_dst(skb)) ^ (__force u16) tc_skb_protocol(skb);
 102 }
 103
 104 static u32 flow_get_iif(const struct sk_buff *skb)
 105 {
 106         return skb->skb_iif;
 107 }
 108
 109 static u32 flow_get_priority(const struct sk_buff *skb)
 110 {
 111         return skb->priority;
 112 }
 113
 114 static u32 flow_get_mark(const struct sk_buff *skb)
 115 {
 116         return skb->mark;
 117 }
 118
 119 static u32 flow_get_nfct(const struct sk_buff *skb)
 120 {
 121 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
 122         return addr_fold(skb->nfct);
 123 #else
 124         return 0;
 125 #endif
 126 }
 127
 128 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
 129 #define CTTUPLE(skb, member)                                            \
 130 ({                                                                      \
 131         enum ip_conntrack_info ctinfo;                                  \
 132         const struct nf_conn *ct = nf_ct_get(skb, &ctinfo);             \
 133         if (ct == NULL)                                                 \
 134                 goto fallback;                                          \
 135         ct->tuplehash[CTINFO2DIR(ctinfo)].tuple.member;                 \
 136 })
 137 #else
 138 #define CTTUPLE(skb, member)                                            \
 139 ({                                                                      \
 140         goto fallback;                                                  \
 141         0;                                                              \
 142 })
 143 #endif
 144
 145 static u32 flow_get_nfct_src(const struct sk_buff *skb, const struct flow_keys *flow)
 146 {
 147         switch (tc_skb_protocol(skb)) {
 148         case htons(ETH_P_IP):
 149                 return ntohl(CTTUPLE(skb, src.u3.ip));
 150         case htons(ETH_P_IPV6):
 151                 return ntohl(CTTUPLE(skb, src.u3.ip6[3]));
 152         }
 153 fallback:
 154         return flow_get_src(skb, flow);
 155 }
 156
 157 static u32 flow_get_nfct_dst(const struct sk_buff *skb, const struct flow_keys *flow)
 158 {
 159         switch (tc_skb_protocol(skb)) {
 160         case htons(ETH_P_IP):
 161                 return ntohl(CTTUPLE(skb, dst.u3.ip));
 162         case htons(ETH_P_IPV6):
 163                 return ntohl(CTTUPLE(skb, dst.u3.ip6[3]));
 164         }
 165 fallback:
 166         return flow_get_dst(skb, flow);
 167 }
 168
 169 static u32 flow_get_nfct_proto_src(const struct sk_buff *skb, const struct flow_keys *flow)
 170 {
 171         return ntohs(CTTUPLE(skb, src.u.all));
 172 fallback:
 173         return flow_get_proto_src(skb, flow);
 174 }
 175
 176 static u32 flow_get_nfct_proto_dst(const struct sk_buff *skb, const struct flow_keys *flow)
 177 {
 178         return ntohs(CTTUPLE(skb, dst.u.all));
 179 fallback:
 180         return flow_get_proto_dst(skb, flow);
 181 }
 182
 183 static u32 flow_get_rtclassid(const struct sk_buff *skb)
 184 {
 185 #ifdef CONFIG_IP_ROUTE_CLASSID
 186         if (skb_dst(skb))
 187                 return skb_dst(skb)->tclassid;
 188 #endif
 189         return 0;
 190 }
 191
 192 static u32 flow_get_skuid(const struct sk_buff *skb)
 193 {
 194         if (skb->sk && skb->sk->sk_socket && skb->sk->sk_socket->file) {
 195                 kuid_t skuid = skb->sk->sk_socket->file->f_cred->fsuid;
 196                 return from_kuid(&init_user_ns, skuid);
 197         }
 198         return 0;
 199 }
 200
 201 static u32 flow_get_skgid(const struct sk_buff *skb)
 202 {
 203         if (skb->sk && skb->sk->sk_socket && skb->sk->sk_socket->file) {
 204                 kgid_t skgid = skb->sk->sk_socket->file->f_cred->fsgid;
 205                 return from_kgid(&init_user_ns, skgid);
 206         }
 207         return 0;
 208 }
 209
 210 static u32 flow_get_vlan_tag(const struct sk_buff *skb)
 211 {
 212         u16 uninitialized_var(tag);
 213
 214         if (vlan_get_tag(skb, &tag) < 0)
 215                 return 0;
 216         return tag & VLAN_VID_MASK;
 217 }
 218
 219 static u32 flow_get_rxhash(struct sk_buff *skb)
 220 {
 221         return skb_get_hash(skb);
 222 }
 223
 224 static u32 flow_key_get(struct sk_buff *skb, int key, struct flow_keys *flow)
 225 {
 226         switch (key) {
 227         case FLOW_KEY_SRC:
 228                 return flow_get_src(skb, flow);
 229         case FLOW_KEY_DST:
 230                 return flow_get_dst(skb, flow);
 231         case FLOW_KEY_PROTO:
 232                 return flow_get_proto(skb, flow);
 233         case FLOW_KEY_PROTO_SRC:
 234                 return flow_get_proto_src(skb, flow);
 235         case FLOW_KEY_PROTO_DST:
 236                 return flow_get_proto_dst(skb, flow);
 237         case FLOW_KEY_IIF:
 238                 return flow_get_iif(skb);
 239         case FLOW_KEY_PRIORITY:
 240                 return flow_get_priority(skb);
 241         case FLOW_KEY_MARK:
 242                 return flow_get_mark(skb);
 243         case FLOW_KEY_NFCT:
 244                 return flow_get_nfct(skb);
 245         case FLOW_KEY_NFCT_SRC:
 246                 return flow_get_nfct_src(skb, flow);
 247         case FLOW_KEY_NFCT_DST:
 248                 return flow_get_nfct_dst(skb, flow);
 249         case FLOW_KEY_NFCT_PROTO_SRC:
 250                 return flow_get_nfct_proto_src(skb, flow);
 251         case FLOW_KEY_NFCT_PROTO_DST:
 252                 return flow_get_nfct_proto_dst(skb, flow);
 253         case FLOW_KEY_RTCLASSID:
 254                 return flow_get_rtclassid(skb);
 255         case FLOW_KEY_SKUID:
 256                 return flow_get_skuid(skb);
 257         case FLOW_KEY_SKGID:
 258                 return flow_get_skgid(skb);
 259         case FLOW_KEY_VLAN_TAG:
 260                 return flow_get_vlan_tag(skb);
 261         case FLOW_KEY_RXHASH:
 262                 return flow_get_rxhash(skb);
 263         default:
 264                 WARN_ON(1);
 265                 return 0;
 266         }
 267 }
 268
 269 #define FLOW_KEYS_NEEDED ((1 << FLOW_KEY_SRC) |                 \
 270                           (1 << FLOW_KEY_DST) |                 \
 271                           (1 << FLOW_KEY_PROTO) |               \
 272                           (1 << FLOW_KEY_PROTO_SRC) |           \
 273                           (1 << FLOW_KEY_PROTO_DST) |           \
 274                           (1 << FLOW_KEY_NFCT_SRC) |            \
 275                           (1 << FLOW_KEY_NFCT_DST) |            \
 276                           (1 << FLOW_KEY_NFCT_PROTO_SRC) |      \
 277                           (1 << FLOW_KEY_NFCT_PROTO_DST))
 278
 279 static int flow_classify(struct sk_buff *skb, const struct tcf_proto *tp,
 280                          struct tcf_result *res)
 281 {
 282         struct flow_head *head = rcu_dereference_bh(tp->root);
 283         struct flow_filter *f;
 284         u32 keymask;
 285         u32 classid;
 286         unsigned int n, key;
 287         int r;
 288
 289         list_for_each_entry_rcu(f, &head->filters, list) {
 290                 u32 keys[FLOW_KEY_MAX + 1];
 291                 struct flow_keys flow_keys;
 292
 293                 if (!tcf_em_tree_match(skb, &f->ematches, NULL))
 294                         continue;
 295
 296                 keymask = f->keymask;
 297                 if (keymask & FLOW_KEYS_NEEDED)
 298                         skb_flow_dissect(skb, &flow_keys);
 299
 300                 for (n = 0; n < f->nkeys; n++) {
 301                         key = ffs(keymask) - 1;
 302                         keymask &= ~(1 << key);
 303                         keys[n] = flow_key_get(skb, key, &flow_keys);
 304                 }
 305
 306                 if (f->mode == FLOW_MODE_HASH)
 307                         classid = jhash2(keys, f->nkeys, f->hashrnd);
 308                 else {
 309                         classid = keys[0];
 310                         classid = (classid & f->mask) ^ f->xor;
 311                         classid = (classid >> f->rshift) + f->addend;
 312                 }
 313
 314                 if (f->divisor)
 315                         classid %= f->divisor;
 316
 317                 res->class   = 0;
 318                 res->classid = TC_H_MAKE(f->baseclass, f->baseclass + classid);
 319
 320                 r = tcf_exts_exec(skb, &f->exts, res);
 321                 if (r < 0)
 322                         continue;
 323                 return r;
 324         }
 325         return -1;
 326 }
 327
 328 static void flow_perturbation(unsigned long arg)
 329 {
 330         struct flow_filter *f = (struct flow_filter *)arg;
 331
 332         get_random_bytes(&f->hashrnd, 4);
 333         if (f->perturb_period)
 334                 mod_timer(&f->perturb_timer, jiffies + f->perturb_period);
 335 }
 336
 337 static const struct nla_policy flow_policy[TCA_FLOW_MAX + 1] = {
 338         [TCA_FLOW_KEYS]         = { .type = NLA_U32 },
 339         [TCA_FLOW_MODE]         = { .type = NLA_U32 },
 340         [TCA_FLOW_BASECLASS]    = { .type = NLA_U32 },
 341         [TCA_FLOW_RSHIFT]       = { .type = NLA_U32 },
 342         [TCA_FLOW_ADDEND]       = { .type = NLA_U32 },
 343         [TCA_FLOW_MASK]         = { .type = NLA_U32 },
 344         [TCA_FLOW_XOR]          = { .type = NLA_U32 },
 345         [TCA_FLOW_DIVISOR]      = { .type = NLA_U32 },
 346         [TCA_FLOW_ACT]          = { .type = NLA_NESTED },
 347         [TCA_FLOW_POLICE]       = { .type = NLA_NESTED },
 348         [TCA_FLOW_EMATCHES]     = { .type = NLA_NESTED },
 349         [TCA_FLOW_PERTURB]      = { .type = NLA_U32 },
 350 };
 351
 352 static void flow_destroy_filter(struct rcu_head *head)
 353 {
 354         struct flow_filter *f = container_of(head, struct flow_filter, rcu);
 355
 356         del_timer_sync(&f->perturb_timer);
 357         tcf_exts_destroy(&f->exts);
 358         tcf_em_tree_destroy(&f->ematches);
 359         kfree(f);
 360 }
 361
 362 static int flow_change(struct net *net, struct sk_buff *in_skb,
 363                        struct tcf_proto *tp, unsigned long base,
 364                        u32 handle, struct nlattr **tca,
 365                        unsigned long *arg, bool ovr)
 366 {
 367         struct flow_head *head = rtnl_dereference(tp->root);
 368         struct flow_filter *fold, *fnew;
 369         struct nlattr *opt = tca[TCA_OPTIONS];
 370         struct nlattr *tb[TCA_FLOW_MAX + 1];
 371         struct tcf_exts e;
 372         struct tcf_ematch_tree t;
 373         unsigned int nkeys = 0;
 374         unsigned int perturb_period = 0;
 375         u32 baseclass = 0;
 376         u32 keymask = 0;
 377         u32 mode;
 378         int err;
 379
 380         if (opt == NULL)
 381                 return -EINVAL;
 382
 383         err = nla_parse_nested(tb, TCA_FLOW_MAX, opt, flow_policy);
 384         if (err < 0)
 385                 return err;
 386
 387         if (tb[TCA_FLOW_BASECLASS]) {
 388                 baseclass = nla_get_u32(tb[TCA_FLOW_BASECLASS]);
 389                 if (TC_H_MIN(baseclass) == 0)
 390                         return -EINVAL;
 391         }
 392
 393         if (tb[TCA_FLOW_KEYS]) {
 394                 keymask = nla_get_u32(tb[TCA_FLOW_KEYS]);
 395
 396                 nkeys = hweight32(keymask);
 397                 if (nkeys == 0)
 398                         return -EINVAL;
 399
 400                 if (fls(keymask) - 1 > FLOW_KEY_MAX)
 401                         return -EOPNOTSUPP;
 402
 403                 if ((keymask & (FLOW_KEY_SKUID|FLOW_KEY_SKGID)) &&
 404                     sk_user_ns(NETLINK_CB(in_skb).sk) != &init_user_ns)
 405                         return -EOPNOTSUPP;
 406         }
 407
 408         tcf_exts_init(&e, TCA_FLOW_ACT, TCA_FLOW_POLICE);
 409         err = tcf_exts_validate(net, tp, tb, tca[TCA_RATE], &e, ovr);
 410         if (err < 0)
 411                 return err;
 412
 413         err = tcf_em_tree_validate(tp, tb[TCA_FLOW_EMATCHES], &t);
 414         if (err < 0)
 415                 goto err1;
 416
 417         err = -ENOBUFS;
 418         fnew = kzalloc(sizeof(*fnew), GFP_KERNEL);
 419         if (!fnew)
 420                 goto err2;
 421
 422         fold = (struct flow_filter *)*arg;
 423         if (fold) {
 424                 err = -EINVAL;
 425                 if (fold->handle != handle && handle)
 426                         goto err2;
 427
 428                 /* Copy fold into fnew */
 429                 fnew->tp = fold->tp;
 430                 fnew->handle = fold->handle;
 431                 fnew->nkeys = fold->nkeys;
 432                 fnew->keymask = fold->keymask;
 433                 fnew->mode = fold->mode;
 434                 fnew->mask = fold->mask;
 435                 fnew->xor = fold->xor;
 436                 fnew->rshift = fold->rshift;
 437                 fnew->addend = fold->addend;
 438                 fnew->divisor = fold->divisor;
 439                 fnew->baseclass = fold->baseclass;
 440                 fnew->hashrnd = fold->hashrnd;
 441
 442                 mode = fold->mode;
 443                 if (tb[TCA_FLOW_MODE])
 444                         mode = nla_get_u32(tb[TCA_FLOW_MODE]);
 445                 if (mode != FLOW_MODE_HASH && nkeys > 1)
 446                         goto err2;
 447
 448                 if (mode == FLOW_MODE_HASH)
 449                         perturb_period = fold->perturb_period;
 450                 if (tb[TCA_FLOW_PERTURB]) {
 451                         if (mode != FLOW_MODE_HASH)
 452                                 goto err2;
 453                         perturb_period = nla_get_u32(tb[TCA_FLOW_PERTURB]) * HZ;
 454                 }
 455         } else {
 456                 err = -EINVAL;
 457                 if (!handle)
 458                         goto err2;
 459                 if (!tb[TCA_FLOW_KEYS])
 460                         goto err2;
 461
 462                 mode = FLOW_MODE_MAP;
 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 (tb[TCA_FLOW_PERTURB]) {
 469                         if (mode != FLOW_MODE_HASH)
 470                                 goto err2;
 471                         perturb_period = nla_get_u32(tb[TCA_FLOW_PERTURB]) * HZ;
 472                 }
 473
 474                 if (TC_H_MAJ(baseclass) == 0)
 475                         baseclass = TC_H_MAKE(tp->q->handle, baseclass);
 476                 if (TC_H_MIN(baseclass) == 0)
 477                         baseclass = TC_H_MAKE(baseclass, 1);
 478
 479                 fnew->handle = handle;
 480                 fnew->mask  = ~0U;
 481                 fnew->tp = tp;
 482                 get_random_bytes(&fnew->hashrnd, 4);
 483                 tcf_exts_init(&fnew->exts, TCA_FLOW_ACT, TCA_FLOW_POLICE);
 484         }
 485
 486         fnew->perturb_timer.function = flow_perturbation;
 487         fnew->perturb_timer.data = (unsigned long)fnew;
 488         init_timer_deferrable(&fnew->perturb_timer);
 489
 490         tcf_exts_change(tp, &fnew->exts, &e);
 491         tcf_em_tree_change(tp, &fnew->ematches, &t);
 492
 493         netif_keep_dst(qdisc_dev(tp->q));
 494
 495         if (tb[TCA_FLOW_KEYS]) {
 496                 fnew->keymask = keymask;
 497                 fnew->nkeys   = nkeys;
 498         }
 499
 500         fnew->mode = mode;
 501
 502         if (tb[TCA_FLOW_MASK])
 503                 fnew->mask = nla_get_u32(tb[TCA_FLOW_MASK]);
 504         if (tb[TCA_FLOW_XOR])
 505                 fnew->xor = nla_get_u32(tb[TCA_FLOW_XOR]);
 506         if (tb[TCA_FLOW_RSHIFT])
 507                 fnew->rshift = nla_get_u32(tb[TCA_FLOW_RSHIFT]);
 508         if (tb[TCA_FLOW_ADDEND])
 509                 fnew->addend = nla_get_u32(tb[TCA_FLOW_ADDEND]);
 510
 511         if (tb[TCA_FLOW_DIVISOR])
 512                 fnew->divisor = nla_get_u32(tb[TCA_FLOW_DIVISOR]);
 513         if (baseclass)
 514                 fnew->baseclass = baseclass;
 515
 516         fnew->perturb_period = perturb_period;
 517         if (perturb_period)
 518                 mod_timer(&fnew->perturb_timer, jiffies + perturb_period);
 519
 520         if (*arg == 0)
 521                 list_add_tail_rcu(&fnew->list, &head->filters);
 522         else
 523                 list_replace_rcu(&fnew->list, &fold->list);
 524
 525         *arg = (unsigned long)fnew;
 526
 527         if (fold)
 528                 call_rcu(&fold->rcu, flow_destroy_filter);
 529         return 0;
 530
 531 err2:
 532         tcf_em_tree_destroy(&t);
 533         kfree(fnew);
 534 err1:
 535         tcf_exts_destroy(&e);
 536         return err;
 537 }
 538
 539 static int flow_delete(struct tcf_proto *tp, unsigned long arg)
 540 {
 541         struct flow_filter *f = (struct flow_filter *)arg;
 542
 543         list_del_rcu(&f->list);
 544         call_rcu(&f->rcu, flow_destroy_filter);
 545         return 0;
 546 }
 547
 548 static int flow_init(struct tcf_proto *tp)
 549 {
 550         struct flow_head *head;
 551
 552         head = kzalloc(sizeof(*head), GFP_KERNEL);
 553         if (head == NULL)
 554                 return -ENOBUFS;
 555         INIT_LIST_HEAD(&head->filters);
 556         rcu_assign_pointer(tp->root, head);
 557         return 0;
 558 }
 559
 560 static bool flow_destroy(struct tcf_proto *tp, bool force)
 561 {
 562         struct flow_head *head = rtnl_dereference(tp->root);
 563         struct flow_filter *f, *next;
 564
 565         if (!force && !list_empty(&head->filters))
 566                 return false;
 567
 568         list_for_each_entry_safe(f, next, &head->filters, list) {
 569                 list_del_rcu(&f->list);
 570                 call_rcu(&f->rcu, flow_destroy_filter);
 571         }
 572         RCU_INIT_POINTER(tp->root, NULL);
 573         kfree_rcu(head, rcu);
 574         return true;
 575 }
 576
 577 static unsigned long flow_get(struct tcf_proto *tp, u32 handle)
 578 {
 579         struct flow_head *head = rtnl_dereference(tp->root);
 580         struct flow_filter *f;
 581
 582         list_for_each_entry(f, &head->filters, list)
 583                 if (f->handle == handle)
 584                         return (unsigned long)f;
 585         return 0;
 586 }
 587
 588 static int flow_dump(struct net *net, struct tcf_proto *tp, unsigned long fh,
 589                      struct sk_buff *skb, struct tcmsg *t)
 590 {
 591         struct flow_filter *f = (struct flow_filter *)fh;
 592         struct nlattr *nest;
 593
 594         if (f == NULL)
 595                 return skb->len;
 596
 597         t->tcm_handle = f->handle;
 598
 599         nest = nla_nest_start(skb, TCA_OPTIONS);
 600         if (nest == NULL)
 601                 goto nla_put_failure;
 602
 603         if (nla_put_u32(skb, TCA_FLOW_KEYS, f->keymask) ||
 604             nla_put_u32(skb, TCA_FLOW_MODE, f->mode))
 605                 goto nla_put_failure;
 606
 607         if (f->mask != ~0 || f->xor != 0) {
 608                 if (nla_put_u32(skb, TCA_FLOW_MASK, f->mask) ||
 609                     nla_put_u32(skb, TCA_FLOW_XOR, f->xor))
 610                         goto nla_put_failure;
 611         }
 612         if (f->rshift &&
 613             nla_put_u32(skb, TCA_FLOW_RSHIFT, f->rshift))
 614                 goto nla_put_failure;
 615         if (f->addend &&
 616             nla_put_u32(skb, TCA_FLOW_ADDEND, f->addend))
 617                 goto nla_put_failure;
 618
 619         if (f->divisor &&
 620             nla_put_u32(skb, TCA_FLOW_DIVISOR, f->divisor))
 621                 goto nla_put_failure;
 622         if (f->baseclass &&
 623             nla_put_u32(skb, TCA_FLOW_BASECLASS, f->baseclass))
 624                 goto nla_put_failure;
 625
 626         if (f->perturb_period &&
 627             nla_put_u32(skb, TCA_FLOW_PERTURB, f->perturb_period / HZ))
 628                 goto nla_put_failure;
 629
 630         if (tcf_exts_dump(skb, &f->exts) < 0)
 631                 goto nla_put_failure;
 632 #ifdef CONFIG_NET_EMATCH
 633         if (f->ematches.hdr.nmatches &&
 634             tcf_em_tree_dump(skb, &f->ematches, TCA_FLOW_EMATCHES) < 0)
 635                 goto nla_put_failure;
 636 #endif
 637         nla_nest_end(skb, nest);
 638
 639         if (tcf_exts_dump_stats(skb, &f->exts) < 0)
 640                 goto nla_put_failure;
 641
 642         return skb->len;
 643
 644 nla_put_failure:
 645         nla_nest_cancel(skb, nest);
 646         return -1;
 647 }
 648
 649 static void flow_walk(struct tcf_proto *tp, struct tcf_walker *arg)
 650 {
 651         struct flow_head *head = rtnl_dereference(tp->root);
 652         struct flow_filter *f;
 653
 654         list_for_each_entry(f, &head->filters, list) {
 655                 if (arg->count < arg->skip)
 656                         goto skip;
 657                 if (arg->fn(tp, (unsigned long)f, arg) < 0) {
 658                         arg->stop = 1;
 659                         break;
 660                 }
 661 skip:
 662                 arg->count++;
 663         }
 664 }
 665
 666 static struct tcf_proto_ops cls_flow_ops __read_mostly = {
 667         .kind           = "flow",
 668         .classify       = flow_classify,
 669         .init           = flow_init,
 670         .destroy        = flow_destroy,
 671         .change         = flow_change,
 672         .delete         = flow_delete,
 673         .get            = flow_get,
 674         .dump           = flow_dump,
 675         .walk           = flow_walk,
 676         .owner          = THIS_MODULE,
 677 };
 678
 679 static int __init cls_flow_init(void)
 680 {
 681         return register_tcf_proto_ops(&cls_flow_ops);
 682 }
 683
 684 static void __exit cls_flow_exit(void)
 685 {
 686         unregister_tcf_proto_ops(&cls_flow_ops);
 687 }
 688
 689 module_init(cls_flow_init);
 690 module_exit(cls_flow_exit);
 691
 692 MODULE_LICENSE("GPL");
 693 MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
 694 MODULE_DESCRIPTION("TC flow classifier");