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