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