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         union {
  61                 struct work_struct      work;
  62                 struct rcu_head         rcu;
  63         };
  64 };
  65
  66 static inline u32 addr_fold(void *addr)
  67 {
  68         unsigned long a = (unsigned long)addr;
  69
  70         return (a & 0xFFFFFFFF) ^ (BITS_PER_LONG > 32 ? a >> 32 : 0);
  71 }
  72
  73 static u32 flow_get_src(const struct sk_buff *skb, const struct flow_keys *flow)
  74 {
  75         __be32 src = flow_get_u32_src(flow);
  76
  77         if (src)
  78                 return ntohl(src);
  79
  80         return addr_fold(skb->sk);
  81 }
  82
  83 static u32 flow_get_dst(const struct sk_buff *skb, const struct flow_keys *flow)
  84 {
  85         __be32 dst = flow_get_u32_dst(flow);
  86
  87         if (dst)
  88                 return ntohl(dst);
  89
  90         return addr_fold(skb_dst(skb)) ^ (__force u16) tc_skb_protocol(skb);
  91 }
  92
  93 static u32 flow_get_proto(const struct sk_buff *skb,
  94                           const struct flow_keys *flow)
  95 {
  96         return flow->basic.ip_proto;
  97 }
  98
  99 static u32 flow_get_proto_src(const struct sk_buff *skb,
 100                               const struct flow_keys *flow)
 101 {
 102         if (flow->ports.ports)
 103                 return ntohs(flow->ports.src);
 104
 105         return addr_fold(skb->sk);
 106 }
 107
 108 static u32 flow_get_proto_dst(const struct sk_buff *skb,
 109                               const struct flow_keys *flow)
 110 {
 111         if (flow->ports.ports)
 112                 return ntohs(flow->ports.dst);
 113
 114         return addr_fold(skb_dst(skb)) ^ (__force u16) tc_skb_protocol(skb);
 115 }
 116
 117 static u32 flow_get_iif(const struct sk_buff *skb)
 118 {
 119         return skb->skb_iif;
 120 }
 121
 122 static u32 flow_get_priority(const struct sk_buff *skb)
 123 {
 124         return skb->priority;
 125 }
 126
 127 static u32 flow_get_mark(const struct sk_buff *skb)
 128 {
 129         return skb->mark;
 130 }
 131
 132 static u32 flow_get_nfct(const struct sk_buff *skb)
 133 {
 134 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
 135         return addr_fold(skb_nfct(skb));
 136 #else
 137         return 0;
 138 #endif
 139 }
 140
 141 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
 142 #define CTTUPLE(skb, member)                                            \
 143 ({                                                                      \
 144         enum ip_conntrack_info ctinfo;                                  \
 145         const struct nf_conn *ct = nf_ct_get(skb, &ctinfo);             \
 146         if (ct == NULL)                                                 \
 147                 goto fallback;                                          \
 148         ct->tuplehash[CTINFO2DIR(ctinfo)].tuple.member;                 \
 149 })
 150 #else
 151 #define CTTUPLE(skb, member)                                            \
 152 ({                                                                      \
 153         goto fallback;                                                  \
 154         0;                                                              \
 155 })
 156 #endif
 157
 158 static u32 flow_get_nfct_src(const struct sk_buff *skb,
 159                              const struct flow_keys *flow)
 160 {
 161         switch (tc_skb_protocol(skb)) {
 162         case htons(ETH_P_IP):
 163                 return ntohl(CTTUPLE(skb, src.u3.ip));
 164         case htons(ETH_P_IPV6):
 165                 return ntohl(CTTUPLE(skb, src.u3.ip6[3]));
 166         }
 167 fallback:
 168         return flow_get_src(skb, flow);
 169 }
 170
 171 static u32 flow_get_nfct_dst(const struct sk_buff *skb,
 172                              const struct flow_keys *flow)
 173 {
 174         switch (tc_skb_protocol(skb)) {
 175         case htons(ETH_P_IP):
 176                 return ntohl(CTTUPLE(skb, dst.u3.ip));
 177         case htons(ETH_P_IPV6):
 178                 return ntohl(CTTUPLE(skb, dst.u3.ip6[3]));
 179         }
 180 fallback:
 181         return flow_get_dst(skb, flow);
 182 }
 183
 184 static u32 flow_get_nfct_proto_src(const struct sk_buff *skb,
 185                                    const struct flow_keys *flow)
 186 {
 187         return ntohs(CTTUPLE(skb, src.u.all));
 188 fallback:
 189         return flow_get_proto_src(skb, flow);
 190 }
 191
 192 static u32 flow_get_nfct_proto_dst(const struct sk_buff *skb,
 193                                    const struct flow_keys *flow)
 194 {
 195         return ntohs(CTTUPLE(skb, dst.u.all));
 196 fallback:
 197         return flow_get_proto_dst(skb, flow);
 198 }
 199
 200 static u32 flow_get_rtclassid(const struct sk_buff *skb)
 201 {
 202 #ifdef CONFIG_IP_ROUTE_CLASSID
 203         if (skb_dst(skb))
 204                 return skb_dst(skb)->tclassid;
 205 #endif
 206         return 0;
 207 }
 208
 209 static u32 flow_get_skuid(const struct sk_buff *skb)
 210 {
 211         struct sock *sk = skb_to_full_sk(skb);
 212
 213         if (sk && sk->sk_socket && sk->sk_socket->file) {
 214                 kuid_t skuid = sk->sk_socket->file->f_cred->fsuid;
 215
 216                 return from_kuid(&init_user_ns, skuid);
 217         }
 218         return 0;
 219 }
 220
 221 static u32 flow_get_skgid(const struct sk_buff *skb)
 222 {
 223         struct sock *sk = skb_to_full_sk(skb);
 224
 225         if (sk && sk->sk_socket && sk->sk_socket->file) {
 226                 kgid_t skgid = sk->sk_socket->file->f_cred->fsgid;
 227
 228                 return from_kgid(&init_user_ns, skgid);
 229         }
 230         return 0;
 231 }
 232
 233 static u32 flow_get_vlan_tag(const struct sk_buff *skb)
 234 {
 235         u16 uninitialized_var(tag);
 236
 237         if (vlan_get_tag(skb, &tag) < 0)
 238                 return 0;
 239         return tag & VLAN_VID_MASK;
 240 }
 241
 242 static u32 flow_get_rxhash(struct sk_buff *skb)
 243 {
 244         return skb_get_hash(skb);
 245 }
 246
 247 static u32 flow_key_get(struct sk_buff *skb, int key, struct flow_keys *flow)
 248 {
 249         switch (key) {
 250         case FLOW_KEY_SRC:
 251                 return flow_get_src(skb, flow);
 252         case FLOW_KEY_DST:
 253                 return flow_get_dst(skb, flow);
 254         case FLOW_KEY_PROTO:
 255                 return flow_get_proto(skb, flow);
 256         case FLOW_KEY_PROTO_SRC:
 257                 return flow_get_proto_src(skb, flow);
 258         case FLOW_KEY_PROTO_DST:
 259                 return flow_get_proto_dst(skb, flow);
 260         case FLOW_KEY_IIF:
 261                 return flow_get_iif(skb);
 262         case FLOW_KEY_PRIORITY:
 263                 return flow_get_priority(skb);
 264         case FLOW_KEY_MARK:
 265                 return flow_get_mark(skb);
 266         case FLOW_KEY_NFCT:
 267                 return flow_get_nfct(skb);
 268         case FLOW_KEY_NFCT_SRC:
 269                 return flow_get_nfct_src(skb, flow);
 270         case FLOW_KEY_NFCT_DST:
 271                 return flow_get_nfct_dst(skb, flow);
 272         case FLOW_KEY_NFCT_PROTO_SRC:
 273                 return flow_get_nfct_proto_src(skb, flow);
 274         case FLOW_KEY_NFCT_PROTO_DST:
 275                 return flow_get_nfct_proto_dst(skb, flow);
 276         case FLOW_KEY_RTCLASSID:
 277                 return flow_get_rtclassid(skb);
 278         case FLOW_KEY_SKUID:
 279                 return flow_get_skuid(skb);
 280         case FLOW_KEY_SKGID:
 281                 return flow_get_skgid(skb);
 282         case FLOW_KEY_VLAN_TAG:
 283                 return flow_get_vlan_tag(skb);
 284         case FLOW_KEY_RXHASH:
 285                 return flow_get_rxhash(skb);
 286         default:
 287                 WARN_ON(1);
 288                 return 0;
 289         }
 290 }
 291
 292 #define FLOW_KEYS_NEEDED ((1 << FLOW_KEY_SRC) |                 \
 293                           (1 << FLOW_KEY_DST) |                 \
 294                           (1 << FLOW_KEY_PROTO) |               \
 295                           (1 << FLOW_KEY_PROTO_SRC) |           \
 296                           (1 << FLOW_KEY_PROTO_DST) |           \
 297                           (1 << FLOW_KEY_NFCT_SRC) |            \
 298                           (1 << FLOW_KEY_NFCT_DST) |            \
 299                           (1 << FLOW_KEY_NFCT_PROTO_SRC) |      \
 300                           (1 << FLOW_KEY_NFCT_PROTO_DST))
 301
 302 static int flow_classify(struct sk_buff *skb, const struct tcf_proto *tp,
 303                          struct tcf_result *res)
 304 {
 305         struct flow_head *head = rcu_dereference_bh(tp->root);
 306         struct flow_filter *f;
 307         u32 keymask;
 308         u32 classid;
 309         unsigned int n, key;
 310         int r;
 311
 312         list_for_each_entry_rcu(f, &head->filters, list) {
 313                 u32 keys[FLOW_KEY_MAX + 1];
 314                 struct flow_keys flow_keys;
 315
 316                 if (!tcf_em_tree_match(skb, &f->ematches, NULL))
 317                         continue;
 318
 319                 keymask = f->keymask;
 320                 if (keymask & FLOW_KEYS_NEEDED)
 321                         skb_flow_dissect_flow_keys(skb, &flow_keys, 0);
 322
 323                 for (n = 0; n < f->nkeys; n++) {
 324                         key = ffs(keymask) - 1;
 325                         keymask &= ~(1 << key);
 326                         keys[n] = flow_key_get(skb, key, &flow_keys);
 327                 }
 328
 329                 if (f->mode == FLOW_MODE_HASH)
 330                         classid = jhash2(keys, f->nkeys, f->hashrnd);
 331                 else {
 332                         classid = keys[0];
 333                         classid = (classid & f->mask) ^ f->xor;
 334                         classid = (classid >> f->rshift) + f->addend;
 335                 }
 336
 337                 if (f->divisor)
 338                         classid %= f->divisor;
 339
 340                 res->class   = 0;
 341                 res->classid = TC_H_MAKE(f->baseclass, f->baseclass + classid);
 342
 343                 r = tcf_exts_exec(skb, &f->exts, res);
 344                 if (r < 0)
 345                         continue;
 346                 return r;
 347         }
 348         return -1;
 349 }
 350
 351 static void flow_perturbation(unsigned long arg)
 352 {
 353         struct flow_filter *f = (struct flow_filter *)arg;
 354
 355         get_random_bytes(&f->hashrnd, 4);
 356         if (f->perturb_period)
 357                 mod_timer(&f->perturb_timer, jiffies + f->perturb_period);
 358 }
 359
 360 static const struct nla_policy flow_policy[TCA_FLOW_MAX + 1] = {
 361         [TCA_FLOW_KEYS]         = { .type = NLA_U32 },
 362         [TCA_FLOW_MODE]         = { .type = NLA_U32 },
 363         [TCA_FLOW_BASECLASS]    = { .type = NLA_U32 },
 364         [TCA_FLOW_RSHIFT]       = { .type = NLA_U32 },
 365         [TCA_FLOW_ADDEND]       = { .type = NLA_U32 },
 366         [TCA_FLOW_MASK]         = { .type = NLA_U32 },
 367         [TCA_FLOW_XOR]          = { .type = NLA_U32 },
 368         [TCA_FLOW_DIVISOR]      = { .type = NLA_U32 },
 369         [TCA_FLOW_ACT]          = { .type = NLA_NESTED },
 370         [TCA_FLOW_POLICE]       = { .type = NLA_NESTED },
 371         [TCA_FLOW_EMATCHES]     = { .type = NLA_NESTED },
 372         [TCA_FLOW_PERTURB]      = { .type = NLA_U32 },
 373 };
 374
 375 static void flow_destroy_filter_work(struct work_struct *work)
 376 {
 377         struct flow_filter *f = container_of(work, struct flow_filter, work);
 378
 379         rtnl_lock();
 380         del_timer_sync(&f->perturb_timer);
 381         tcf_exts_destroy(&f->exts);
 382         tcf_em_tree_destroy(&f->ematches);
 383         kfree(f);
 384         rtnl_unlock();
 385 }
 386
 387 static void flow_destroy_filter(struct rcu_head *head)
 388 {
 389         struct flow_filter *f = container_of(head, struct flow_filter, rcu);
 390
 391         INIT_WORK(&f->work, flow_destroy_filter_work);
 392         tcf_queue_work(&f->work);
 393 }
 394
 395 static int flow_change(struct net *net, struct sk_buff *in_skb,
 396                        struct tcf_proto *tp, unsigned long base,
 397                        u32 handle, struct nlattr **tca,
 398                        void **arg, bool ovr)
 399 {
 400         struct flow_head *head = rtnl_dereference(tp->root);
 401         struct flow_filter *fold, *fnew;
 402         struct nlattr *opt = tca[TCA_OPTIONS];
 403         struct nlattr *tb[TCA_FLOW_MAX + 1];
 404         unsigned int nkeys = 0;
 405         unsigned int perturb_period = 0;
 406         u32 baseclass = 0;
 407         u32 keymask = 0;
 408         u32 mode;
 409         int err;
 410
 411         if (opt == NULL)
 412                 return -EINVAL;
 413
 414         err = nla_parse_nested(tb, TCA_FLOW_MAX, opt, flow_policy, NULL);
 415         if (err < 0)
 416                 return err;
 417
 418         if (tb[TCA_FLOW_BASECLASS]) {
 419                 baseclass = nla_get_u32(tb[TCA_FLOW_BASECLASS]);
 420                 if (TC_H_MIN(baseclass) == 0)
 421                         return -EINVAL;
 422         }
 423
 424         if (tb[TCA_FLOW_KEYS]) {
 425                 keymask = nla_get_u32(tb[TCA_FLOW_KEYS]);
 426
 427                 nkeys = hweight32(keymask);
 428                 if (nkeys == 0)
 429                         return -EINVAL;
 430
 431                 if (fls(keymask) - 1 > FLOW_KEY_MAX)
 432                         return -EOPNOTSUPP;
 433
 434                 if ((keymask & (FLOW_KEY_SKUID|FLOW_KEY_SKGID)) &&
 435                     sk_user_ns(NETLINK_CB(in_skb).sk) != &init_user_ns)
 436                         return -EOPNOTSUPP;
 437         }
 438
 439         fnew = kzalloc(sizeof(*fnew), GFP_KERNEL);
 440         if (!fnew)
 441                 return -ENOBUFS;
 442
 443         err = tcf_em_tree_validate(tp, tb[TCA_FLOW_EMATCHES], &fnew->ematches);
 444         if (err < 0)
 445                 goto err1;
 446
 447         err = tcf_exts_init(&fnew->exts, TCA_FLOW_ACT, TCA_FLOW_POLICE);
 448         if (err < 0)
 449                 goto err2;
 450
 451         err = tcf_exts_validate(net, tp, tb, tca[TCA_RATE], &fnew->exts, ovr);
 452         if (err < 0)
 453                 goto err2;
 454
 455         fold = *arg;
 456         if (fold) {
 457                 err = -EINVAL;
 458                 if (fold->handle != handle && handle)
 459                         goto err2;
 460
 461                 /* Copy fold into fnew */
 462                 fnew->tp = fold->tp;
 463                 fnew->handle = fold->handle;
 464                 fnew->nkeys = fold->nkeys;
 465                 fnew->keymask = fold->keymask;
 466                 fnew->mode = fold->mode;
 467                 fnew->mask = fold->mask;
 468                 fnew->xor = fold->xor;
 469                 fnew->rshift = fold->rshift;
 470                 fnew->addend = fold->addend;
 471                 fnew->divisor = fold->divisor;
 472                 fnew->baseclass = fold->baseclass;
 473                 fnew->hashrnd = fold->hashrnd;
 474
 475                 mode = fold->mode;
 476                 if (tb[TCA_FLOW_MODE])
 477                         mode = nla_get_u32(tb[TCA_FLOW_MODE]);
 478                 if (mode != FLOW_MODE_HASH && nkeys > 1)
 479                         goto err2;
 480
 481                 if (mode == FLOW_MODE_HASH)
 482                         perturb_period = fold->perturb_period;
 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         } else {
 489                 err = -EINVAL;
 490                 if (!handle)
 491                         goto err2;
 492                 if (!tb[TCA_FLOW_KEYS])
 493                         goto err2;
 494
 495                 mode = FLOW_MODE_MAP;
 496                 if (tb[TCA_FLOW_MODE])
 497                         mode = nla_get_u32(tb[TCA_FLOW_MODE]);
 498                 if (mode != FLOW_MODE_HASH && nkeys > 1)
 499                         goto err2;
 500
 501                 if (tb[TCA_FLOW_PERTURB]) {
 502                         if (mode != FLOW_MODE_HASH)
 503                                 goto err2;
 504                         perturb_period = nla_get_u32(tb[TCA_FLOW_PERTURB]) * HZ;
 505                 }
 506
 507                 if (TC_H_MAJ(baseclass) == 0)
 508                         baseclass = TC_H_MAKE(tp->q->handle, baseclass);
 509                 if (TC_H_MIN(baseclass) == 0)
 510                         baseclass = TC_H_MAKE(baseclass, 1);
 511
 512                 fnew->handle = handle;
 513                 fnew->mask  = ~0U;
 514                 fnew->tp = tp;
 515                 get_random_bytes(&fnew->hashrnd, 4);
 516         }
 517
 518         setup_deferrable_timer(&fnew->perturb_timer, flow_perturbation,
 519                                (unsigned long)fnew);
 520
 521         netif_keep_dst(qdisc_dev(tp->q));
 522
 523         if (tb[TCA_FLOW_KEYS]) {
 524                 fnew->keymask = keymask;
 525                 fnew->nkeys   = nkeys;
 526         }
 527
 528         fnew->mode = mode;
 529
 530         if (tb[TCA_FLOW_MASK])
 531                 fnew->mask = nla_get_u32(tb[TCA_FLOW_MASK]);
 532         if (tb[TCA_FLOW_XOR])
 533                 fnew->xor = nla_get_u32(tb[TCA_FLOW_XOR]);
 534         if (tb[TCA_FLOW_RSHIFT])
 535                 fnew->rshift = nla_get_u32(tb[TCA_FLOW_RSHIFT]);
 536         if (tb[TCA_FLOW_ADDEND])
 537                 fnew->addend = nla_get_u32(tb[TCA_FLOW_ADDEND]);
 538
 539         if (tb[TCA_FLOW_DIVISOR])
 540                 fnew->divisor = nla_get_u32(tb[TCA_FLOW_DIVISOR]);
 541         if (baseclass)
 542                 fnew->baseclass = baseclass;
 543
 544         fnew->perturb_period = perturb_period;
 545         if (perturb_period)
 546                 mod_timer(&fnew->perturb_timer, jiffies + perturb_period);
 547
 548         if (!*arg)
 549                 list_add_tail_rcu(&fnew->list, &head->filters);
 550         else
 551                 list_replace_rcu(&fold->list, &fnew->list);
 552
 553         *arg = fnew;
 554
 555         if (fold)
 556                 call_rcu(&fold->rcu, flow_destroy_filter);
 557         return 0;
 558
 559 err2:
 560         tcf_exts_destroy(&fnew->exts);
 561         tcf_em_tree_destroy(&fnew->ematches);
 562 err1:
 563         kfree(fnew);
 564         return err;
 565 }
 566
 567 static int flow_delete(struct tcf_proto *tp, void *arg, bool *last)
 568 {
 569         struct flow_head *head = rtnl_dereference(tp->root);
 570         struct flow_filter *f = arg;
 571
 572         list_del_rcu(&f->list);
 573         call_rcu(&f->rcu, flow_destroy_filter);
 574         *last = list_empty(&head->filters);
 575         return 0;
 576 }
 577
 578 static int flow_init(struct tcf_proto *tp)
 579 {
 580         struct flow_head *head;
 581
 582         head = kzalloc(sizeof(*head), GFP_KERNEL);
 583         if (head == NULL)
 584                 return -ENOBUFS;
 585         INIT_LIST_HEAD(&head->filters);
 586         rcu_assign_pointer(tp->root, head);
 587         return 0;
 588 }
 589
 590 static void flow_destroy(struct tcf_proto *tp)
 591 {
 592         struct flow_head *head = rtnl_dereference(tp->root);
 593         struct flow_filter *f, *next;
 594
 595         list_for_each_entry_safe(f, next, &head->filters, list) {
 596                 list_del_rcu(&f->list);
 597                 call_rcu(&f->rcu, flow_destroy_filter);
 598         }
 599         kfree_rcu(head, rcu);
 600 }
 601
 602 static void *flow_get(struct tcf_proto *tp, u32 handle)
 603 {
 604         struct flow_head *head = rtnl_dereference(tp->root);
 605         struct flow_filter *f;
 606
 607         list_for_each_entry(f, &head->filters, list)
 608                 if (f->handle == handle)
 609                         return f;
 610         return NULL;
 611 }
 612
 613 static int flow_dump(struct net *net, struct tcf_proto *tp, void *fh,
 614                      struct sk_buff *skb, struct tcmsg *t)
 615 {
 616         struct flow_filter *f = fh;
 617         struct nlattr *nest;
 618
 619         if (f == NULL)
 620                 return skb->len;
 621
 622         t->tcm_handle = f->handle;
 623
 624         nest = nla_nest_start(skb, TCA_OPTIONS);
 625         if (nest == NULL)
 626                 goto nla_put_failure;
 627
 628         if (nla_put_u32(skb, TCA_FLOW_KEYS, f->keymask) ||
 629             nla_put_u32(skb, TCA_FLOW_MODE, f->mode))
 630                 goto nla_put_failure;
 631
 632         if (f->mask != ~0 || f->xor != 0) {
 633                 if (nla_put_u32(skb, TCA_FLOW_MASK, f->mask) ||
 634                     nla_put_u32(skb, TCA_FLOW_XOR, f->xor))
 635                         goto nla_put_failure;
 636         }
 637         if (f->rshift &&
 638             nla_put_u32(skb, TCA_FLOW_RSHIFT, f->rshift))
 639                 goto nla_put_failure;
 640         if (f->addend &&
 641             nla_put_u32(skb, TCA_FLOW_ADDEND, f->addend))
 642                 goto nla_put_failure;
 643
 644         if (f->divisor &&
 645             nla_put_u32(skb, TCA_FLOW_DIVISOR, f->divisor))
 646                 goto nla_put_failure;
 647         if (f->baseclass &&
 648             nla_put_u32(skb, TCA_FLOW_BASECLASS, f->baseclass))
 649                 goto nla_put_failure;
 650
 651         if (f->perturb_period &&
 652             nla_put_u32(skb, TCA_FLOW_PERTURB, f->perturb_period / HZ))
 653                 goto nla_put_failure;
 654
 655         if (tcf_exts_dump(skb, &f->exts) < 0)
 656                 goto nla_put_failure;
 657 #ifdef CONFIG_NET_EMATCH
 658         if (f->ematches.hdr.nmatches &&
 659             tcf_em_tree_dump(skb, &f->ematches, TCA_FLOW_EMATCHES) < 0)
 660                 goto nla_put_failure;
 661 #endif
 662         nla_nest_end(skb, nest);
 663
 664         if (tcf_exts_dump_stats(skb, &f->exts) < 0)
 665                 goto nla_put_failure;
 666
 667         return skb->len;
 668
 669 nla_put_failure:
 670         nla_nest_cancel(skb, nest);
 671         return -1;
 672 }
 673
 674 static void flow_walk(struct tcf_proto *tp, struct tcf_walker *arg)
 675 {
 676         struct flow_head *head = rtnl_dereference(tp->root);
 677         struct flow_filter *f;
 678
 679         list_for_each_entry(f, &head->filters, list) {
 680                 if (arg->count < arg->skip)
 681                         goto skip;
 682                 if (arg->fn(tp, f, arg) < 0) {
 683                         arg->stop = 1;
 684                         break;
 685                 }
 686 skip:
 687                 arg->count++;
 688         }
 689 }
 690
 691 static struct tcf_proto_ops cls_flow_ops __read_mostly = {
 692         .kind           = "flow",
 693         .classify       = flow_classify,
 694         .init           = flow_init,
 695         .destroy        = flow_destroy,
 696         .change         = flow_change,
 697         .delete         = flow_delete,
 698         .get            = flow_get,
 699         .dump           = flow_dump,
 700         .walk           = flow_walk,
 701         .owner          = THIS_MODULE,
 702 };
 703
 704 static int __init cls_flow_init(void)
 705 {
 706         return register_tcf_proto_ops(&cls_flow_ops);
 707 }
 708
 709 static void __exit cls_flow_exit(void)
 710 {
 711         unregister_tcf_proto_ops(&cls_flow_ops);
 712 }
 713
 714 module_init(cls_flow_init);
 715 module_exit(cls_flow_exit);
 716
 717 MODULE_LICENSE("GPL");
 718 MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
 719 MODULE_DESCRIPTION("TC flow classifier");