net/sched/cls_flow.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * net/sched/cls_flow.c         Generic flow classifier
   4  *
   5  * Copyright (c) 2007, 2008 Patrick McHardy <kaber@trash.net>
   6  */
   7
   8 #include <linux/kernel.h>
   9 #include <linux/init.h>
  10 #include <linux/list.h>
  11 #include <linux/jhash.h>
  12 #include <linux/random.h>
  13 #include <linux/pkt_cls.h>
  14 #include <linux/skbuff.h>
  15 #include <linux/in.h>
  16 #include <linux/ip.h>
  17 #include <linux/ipv6.h>
  18 #include <linux/if_vlan.h>
  19 #include <linux/slab.h>
  20 #include <linux/module.h>
  21 #include <net/inet_sock.h>
  22
  23 #include <net/pkt_cls.h>
  24 #include <net/ip.h>
  25 #include <net/route.h>
  26 #include <net/flow_dissector.h>
  27
  28 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
  29 #include <net/netfilter/nf_conntrack.h>
  30 #endif
  31
  32 struct flow_head {
  33         struct list_head        filters;
  34         struct rcu_head         rcu;
  35 };
  36
  37 struct flow_filter {
  38         struct list_head        list;
  39         struct tcf_exts         exts;
  40         struct tcf_ematch_tree  ematches;
  41         struct tcf_proto        *tp;
  42         struct timer_list       perturb_timer;
  43         u32                     perturb_period;
  44         u32                     handle;
  45
  46         u32                     nkeys;
  47         u32                     keymask;
  48         u32                     mode;
  49         u32                     mask;
  50         u32                     xor;
  51         u32                     rshift;
  52         u32                     addend;
  53         u32                     divisor;
  54         u32                     baseclass;
  55         u32                     hashrnd;
  56         struct rcu_work         rwork;
  57 };
  58
  59 static inline u32 addr_fold(void *addr)
  60 {
  61         unsigned long a = (unsigned long)addr;
  62
  63         return (a & 0xFFFFFFFF) ^ (BITS_PER_LONG > 32 ? a >> 32 : 0);
  64 }
  65
  66 static u32 flow_get_src(const struct sk_buff *skb, const struct flow_keys *flow)
  67 {
  68         __be32 src = flow_get_u32_src(flow);
  69
  70         if (src)
  71                 return ntohl(src);
  72
  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         __be32 dst = flow_get_u32_dst(flow);
  79
  80         if (dst)
  81                 return ntohl(dst);
  82
  83         return addr_fold(skb_dst(skb)) ^ (__force u16)skb_protocol(skb, true);
  84 }
  85
  86 static u32 flow_get_proto(const struct sk_buff *skb,
  87                           const struct flow_keys *flow)
  88 {
  89         return flow->basic.ip_proto;
  90 }
  91
  92 static u32 flow_get_proto_src(const struct sk_buff *skb,
  93                               const struct flow_keys *flow)
  94 {
  95         if (flow->ports.ports)
  96                 return ntohs(flow->ports.src);
  97
  98         return addr_fold(skb->sk);
  99 }
 100
 101 static u32 flow_get_proto_dst(const struct sk_buff *skb,
 102                               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)skb_protocol(skb, true);
 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 IS_ENABLED(CONFIG_NF_CONNTRACK)
 128         return addr_fold(skb_nfct(skb));
 129 #else
 130         return 0;
 131 #endif
 132 }
 133
 134 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
 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,
 152                              const struct flow_keys *flow)
 153 {
 154         switch (skb_protocol(skb, true)) {
 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,
 165                              const struct flow_keys *flow)
 166 {
 167         switch (skb_protocol(skb, true)) {
 168         case htons(ETH_P_IP):
 169                 return ntohl(CTTUPLE(skb, dst.u3.ip));
 170         case htons(ETH_P_IPV6):
 171                 return ntohl(CTTUPLE(skb, dst.u3.ip6[3]));
 172         }
 173 fallback:
 174         return flow_get_dst(skb, flow);
 175 }
 176
 177 static u32 flow_get_nfct_proto_src(const struct sk_buff *skb,
 178                                    const struct flow_keys *flow)
 179 {
 180         return ntohs(CTTUPLE(skb, src.u.all));
 181 fallback:
 182         return flow_get_proto_src(skb, flow);
 183 }
 184
 185 static u32 flow_get_nfct_proto_dst(const struct sk_buff *skb,
 186                                    const struct flow_keys *flow)
 187 {
 188         return ntohs(CTTUPLE(skb, dst.u.all));
 189 fallback:
 190         return flow_get_proto_dst(skb, flow);
 191 }
 192
 193 static u32 flow_get_rtclassid(const struct sk_buff *skb)
 194 {
 195 #ifdef CONFIG_IP_ROUTE_CLASSID
 196         if (skb_dst(skb))
 197                 return skb_dst(skb)->tclassid;
 198 #endif
 199         return 0;
 200 }
 201
 202 static u32 flow_get_skuid(const struct sk_buff *skb)
 203 {
 204         struct sock *sk = skb_to_full_sk(skb);
 205
 206         if (sk && sk->sk_socket && sk->sk_socket->file) {
 207                 kuid_t skuid = sk->sk_socket->file->f_cred->fsuid;
 208
 209                 return from_kuid(&init_user_ns, skuid);
 210         }
 211         return 0;
 212 }
 213
 214 static u32 flow_get_skgid(const struct sk_buff *skb)
 215 {
 216         struct sock *sk = skb_to_full_sk(skb);
 217
 218         if (sk && sk->sk_socket && sk->sk_socket->file) {
 219                 kgid_t skgid = sk->sk_socket->file->f_cred->fsgid;
 220
 221                 return from_kgid(&init_user_ns, skgid);
 222         }
 223         return 0;
 224 }
 225
 226 static u32 flow_get_vlan_tag(const struct sk_buff *skb)
 227 {
 228         u16 tag;
 229
 230         if (vlan_get_tag(skb, &tag) < 0)
 231                 return 0;
 232         return tag & VLAN_VID_MASK;
 233 }
 234
 235 static u32 flow_get_rxhash(struct sk_buff *skb)
 236 {
 237         return skb_get_hash(skb);
 238 }
 239
 240 static u32 flow_key_get(struct sk_buff *skb, int key, struct flow_keys *flow)
 241 {
 242         switch (key) {
 243         case FLOW_KEY_SRC:
 244                 return flow_get_src(skb, flow);
 245         case FLOW_KEY_DST:
 246                 return flow_get_dst(skb, flow);
 247         case FLOW_KEY_PROTO:
 248                 return flow_get_proto(skb, flow);
 249         case FLOW_KEY_PROTO_SRC:
 250                 return flow_get_proto_src(skb, flow);
 251         case FLOW_KEY_PROTO_DST:
 252                 return flow_get_proto_dst(skb, flow);
 253         case FLOW_KEY_IIF:
 254                 return flow_get_iif(skb);
 255         case FLOW_KEY_PRIORITY:
 256                 return flow_get_priority(skb);
 257         case FLOW_KEY_MARK:
 258                 return flow_get_mark(skb);
 259         case FLOW_KEY_NFCT:
 260                 return flow_get_nfct(skb);
 261         case FLOW_KEY_NFCT_SRC:
 262                 return flow_get_nfct_src(skb, flow);
 263         case FLOW_KEY_NFCT_DST:
 264                 return flow_get_nfct_dst(skb, flow);
 265         case FLOW_KEY_NFCT_PROTO_SRC:
 266                 return flow_get_nfct_proto_src(skb, flow);
 267         case FLOW_KEY_NFCT_PROTO_DST:
 268                 return flow_get_nfct_proto_dst(skb, flow);
 269         case FLOW_KEY_RTCLASSID:
 270                 return flow_get_rtclassid(skb);
 271         case FLOW_KEY_SKUID:
 272                 return flow_get_skuid(skb);
 273         case FLOW_KEY_SKGID:
 274                 return flow_get_skgid(skb);
 275         case FLOW_KEY_VLAN_TAG:
 276                 return flow_get_vlan_tag(skb);
 277         case FLOW_KEY_RXHASH:
 278                 return flow_get_rxhash(skb);
 279         default:
 280                 WARN_ON(1);
 281                 return 0;
 282         }
 283 }
 284
 285 #define FLOW_KEYS_NEEDED ((1 << FLOW_KEY_SRC) |                 \
 286                           (1 << FLOW_KEY_DST) |                 \
 287                           (1 << FLOW_KEY_PROTO) |               \
 288                           (1 << FLOW_KEY_PROTO_SRC) |           \
 289                           (1 << FLOW_KEY_PROTO_DST) |           \
 290                           (1 << FLOW_KEY_NFCT_SRC) |            \
 291                           (1 << FLOW_KEY_NFCT_DST) |            \
 292                           (1 << FLOW_KEY_NFCT_PROTO_SRC) |      \
 293                           (1 << FLOW_KEY_NFCT_PROTO_DST))
 294
 295 static int flow_classify(struct sk_buff *skb, const struct tcf_proto *tp,
 296                          struct tcf_result *res)
 297 {
 298         struct flow_head *head = rcu_dereference_bh(tp->root);
 299         struct flow_filter *f;
 300         u32 keymask;
 301         u32 classid;
 302         unsigned int n, key;
 303         int r;
 304
 305         list_for_each_entry_rcu(f, &head->filters, list) {
 306                 u32 keys[FLOW_KEY_MAX + 1];
 307                 struct flow_keys flow_keys;
 308
 309                 if (!tcf_em_tree_match(skb, &f->ematches, NULL))
 310                         continue;
 311
 312                 keymask = f->keymask;
 313                 if (keymask & FLOW_KEYS_NEEDED)
 314                         skb_flow_dissect_flow_keys(skb, &flow_keys, 0);
 315
 316                 for (n = 0; n < f->nkeys; n++) {
 317                         key = ffs(keymask) - 1;
 318                         keymask &= ~(1 << key);
 319                         keys[n] = flow_key_get(skb, key, &flow_keys);
 320                 }
 321
 322                 if (f->mode == FLOW_MODE_HASH)
 323                         classid = jhash2(keys, f->nkeys, f->hashrnd);
 324                 else {
 325                         classid = keys[0];
 326                         classid = (classid & f->mask) ^ f->xor;
 327                         classid = (classid >> f->rshift) + f->addend;
 328                 }
 329
 330                 if (f->divisor)
 331                         classid %= f->divisor;
 332
 333                 res->class   = 0;
 334                 res->classid = TC_H_MAKE(f->baseclass, f->baseclass + classid);
 335
 336                 r = tcf_exts_exec(skb, &f->exts, res);
 337                 if (r < 0)
 338                         continue;
 339                 return r;
 340         }
 341         return -1;
 342 }
 343
 344 static void flow_perturbation(struct timer_list *t)
 345 {
 346         struct flow_filter *f = from_timer(f, t, perturb_timer);
 347
 348         get_random_bytes(&f->hashrnd, 4);
 349         if (f->perturb_period)
 350                 mod_timer(&f->perturb_timer, jiffies + f->perturb_period);
 351 }
 352
 353 static const struct nla_policy flow_policy[TCA_FLOW_MAX + 1] = {
 354         [TCA_FLOW_KEYS]         = { .type = NLA_U32 },
 355         [TCA_FLOW_MODE]         = { .type = NLA_U32 },
 356         [TCA_FLOW_BASECLASS]    = { .type = NLA_U32 },
 357         [TCA_FLOW_RSHIFT]       = { .type = NLA_U32 },
 358         [TCA_FLOW_ADDEND]       = { .type = NLA_U32 },
 359         [TCA_FLOW_MASK]         = { .type = NLA_U32 },
 360         [TCA_FLOW_XOR]          = { .type = NLA_U32 },
 361         [TCA_FLOW_DIVISOR]      = { .type = NLA_U32 },
 362         [TCA_FLOW_ACT]          = { .type = NLA_NESTED },
 363         [TCA_FLOW_POLICE]       = { .type = NLA_NESTED },
 364         [TCA_FLOW_EMATCHES]     = { .type = NLA_NESTED },
 365         [TCA_FLOW_PERTURB]      = { .type = NLA_U32 },
 366 };
 367
 368 static void __flow_destroy_filter(struct flow_filter *f)
 369 {
 370         del_timer_sync(&f->perturb_timer);
 371         tcf_exts_destroy(&f->exts);
 372         tcf_em_tree_destroy(&f->ematches);
 373         tcf_exts_put_net(&f->exts);
 374         kfree(f);
 375 }
 376
 377 static void flow_destroy_filter_work(struct work_struct *work)
 378 {
 379         struct flow_filter *f = container_of(to_rcu_work(work),
 380                                              struct flow_filter,
 381                                              rwork);
 382         rtnl_lock();
 383         __flow_destroy_filter(f);
 384         rtnl_unlock();
 385 }
 386
 387 static int flow_change(struct net *net, struct sk_buff *in_skb,
 388                        struct tcf_proto *tp, unsigned long base,
 389                        u32 handle, struct nlattr **tca,
 390                        void **arg, u32 flags,
 391                        struct netlink_ext_ack *extack)
 392 {
 393         struct flow_head *head = rtnl_dereference(tp->root);
 394         struct flow_filter *fold, *fnew;
 395         struct nlattr *opt = tca[TCA_OPTIONS];
 396         struct nlattr *tb[TCA_FLOW_MAX + 1];
 397         unsigned int nkeys = 0;
 398         unsigned int perturb_period = 0;
 399         u32 baseclass = 0;
 400         u32 keymask = 0;
 401         u32 mode;
 402         int err;
 403
 404         if (opt == NULL)
 405                 return -EINVAL;
 406
 407         err = nla_parse_nested_deprecated(tb, TCA_FLOW_MAX, opt, flow_policy,
 408                                           NULL);
 409         if (err < 0)
 410                 return err;
 411
 412         if (tb[TCA_FLOW_BASECLASS]) {
 413                 baseclass = nla_get_u32(tb[TCA_FLOW_BASECLASS]);
 414                 if (TC_H_MIN(baseclass) == 0)
 415                         return -EINVAL;
 416         }
 417
 418         if (tb[TCA_FLOW_KEYS]) {
 419                 keymask = nla_get_u32(tb[TCA_FLOW_KEYS]);
 420
 421                 nkeys = hweight32(keymask);
 422                 if (nkeys == 0)
 423                         return -EINVAL;
 424
 425                 if (fls(keymask) - 1 > FLOW_KEY_MAX)
 426                         return -EOPNOTSUPP;
 427
 428                 if ((keymask & (FLOW_KEY_SKUID|FLOW_KEY_SKGID)) &&
 429                     sk_user_ns(NETLINK_CB(in_skb).sk) != &init_user_ns)
 430                         return -EOPNOTSUPP;
 431         }
 432
 433         fnew = kzalloc(sizeof(*fnew), GFP_KERNEL);
 434         if (!fnew)
 435                 return -ENOBUFS;
 436
 437         err = tcf_em_tree_validate(tp, tb[TCA_FLOW_EMATCHES], &fnew->ematches);
 438         if (err < 0)
 439                 goto err1;
 440
 441         err = tcf_exts_init(&fnew->exts, net, TCA_FLOW_ACT, TCA_FLOW_POLICE);
 442         if (err < 0)
 443                 goto err2;
 444
 445         err = tcf_exts_validate(net, tp, tb, tca[TCA_RATE], &fnew->exts, flags,
 446                                 extack);
 447         if (err < 0)
 448                 goto err2;
 449
 450         fold = *arg;
 451         if (fold) {
 452                 err = -EINVAL;
 453                 if (fold->handle != handle && handle)
 454                         goto err2;
 455
 456                 /* Copy fold into fnew */
 457                 fnew->tp = fold->tp;
 458                 fnew->handle = fold->handle;
 459                 fnew->nkeys = fold->nkeys;
 460                 fnew->keymask = fold->keymask;
 461                 fnew->mode = fold->mode;
 462                 fnew->mask = fold->mask;
 463                 fnew->xor = fold->xor;
 464                 fnew->rshift = fold->rshift;
 465                 fnew->addend = fold->addend;
 466                 fnew->divisor = fold->divisor;
 467                 fnew->baseclass = fold->baseclass;
 468                 fnew->hashrnd = fold->hashrnd;
 469
 470                 mode = fold->mode;
 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 (mode == FLOW_MODE_HASH)
 477                         perturb_period = fold->perturb_period;
 478                 if (tb[TCA_FLOW_PERTURB]) {
 479                         if (mode != FLOW_MODE_HASH)
 480                                 goto err2;
 481                         perturb_period = nla_get_u32(tb[TCA_FLOW_PERTURB]) * HZ;
 482                 }
 483         } else {
 484                 err = -EINVAL;
 485                 if (!handle)
 486                         goto err2;
 487                 if (!tb[TCA_FLOW_KEYS])
 488                         goto err2;
 489
 490                 mode = FLOW_MODE_MAP;
 491                 if (tb[TCA_FLOW_MODE])
 492                         mode = nla_get_u32(tb[TCA_FLOW_MODE]);
 493                 if (mode != FLOW_MODE_HASH && nkeys > 1)
 494                         goto err2;
 495
 496                 if (tb[TCA_FLOW_PERTURB]) {
 497                         if (mode != FLOW_MODE_HASH)
 498                                 goto err2;
 499                         perturb_period = nla_get_u32(tb[TCA_FLOW_PERTURB]) * HZ;
 500                 }
 501
 502                 if (TC_H_MAJ(baseclass) == 0) {
 503                         struct Qdisc *q = tcf_block_q(tp->chain->block);
 504
 505                         baseclass = TC_H_MAKE(q->handle, baseclass);
 506                 }
 507                 if (TC_H_MIN(baseclass) == 0)
 508                         baseclass = TC_H_MAKE(baseclass, 1);
 509
 510                 fnew->handle = handle;
 511                 fnew->mask  = ~0U;
 512                 fnew->tp = tp;
 513                 get_random_bytes(&fnew->hashrnd, 4);
 514         }
 515
 516         timer_setup(&fnew->perturb_timer, flow_perturbation, TIMER_DEFERRABLE);
 517
 518         tcf_block_netif_keep_dst(tp->chain->block);
 519
 520         if (tb[TCA_FLOW_KEYS]) {
 521                 fnew->keymask = keymask;
 522                 fnew->nkeys   = nkeys;
 523         }
 524
 525         fnew->mode = mode;
 526
 527         if (tb[TCA_FLOW_MASK])
 528                 fnew->mask = nla_get_u32(tb[TCA_FLOW_MASK]);
 529         if (tb[TCA_FLOW_XOR])
 530                 fnew->xor = nla_get_u32(tb[TCA_FLOW_XOR]);
 531         if (tb[TCA_FLOW_RSHIFT])
 532                 fnew->rshift = nla_get_u32(tb[TCA_FLOW_RSHIFT]);
 533         if (tb[TCA_FLOW_ADDEND])
 534                 fnew->addend = nla_get_u32(tb[TCA_FLOW_ADDEND]);
 535
 536         if (tb[TCA_FLOW_DIVISOR])
 537                 fnew->divisor = nla_get_u32(tb[TCA_FLOW_DIVISOR]);
 538         if (baseclass)
 539                 fnew->baseclass = baseclass;
 540
 541         fnew->perturb_period = perturb_period;
 542         if (perturb_period)
 543                 mod_timer(&fnew->perturb_timer, jiffies + perturb_period);
 544
 545         if (!*arg)
 546                 list_add_tail_rcu(&fnew->list, &head->filters);
 547         else
 548                 list_replace_rcu(&fold->list, &fnew->list);
 549
 550         *arg = fnew;
 551
 552         if (fold) {
 553                 tcf_exts_get_net(&fold->exts);
 554                 tcf_queue_work(&fold->rwork, flow_destroy_filter_work);
 555         }
 556         return 0;
 557
 558 err2:
 559         tcf_exts_destroy(&fnew->exts);
 560         tcf_em_tree_destroy(&fnew->ematches);
 561 err1:
 562         kfree(fnew);
 563         return err;
 564 }
 565
 566 static int flow_delete(struct tcf_proto *tp, void *arg, bool *last,
 567                        bool rtnl_held, struct netlink_ext_ack *extack)
 568 {
 569         struct flow_head *head = rtnl_dereference(tp->root);
 570         struct flow_filter *f = arg;
 571
 572         list_del_rcu(&f->list);
 573         tcf_exts_get_net(&f->exts);
 574         tcf_queue_work(&f->rwork, flow_destroy_filter_work);
 575         *last = list_empty(&head->filters);
 576         return 0;
 577 }
 578
 579 static int flow_init(struct tcf_proto *tp)
 580 {
 581         struct flow_head *head;
 582
 583         head = kzalloc(sizeof(*head), GFP_KERNEL);
 584         if (head == NULL)
 585                 return -ENOBUFS;
 586         INIT_LIST_HEAD(&head->filters);
 587         rcu_assign_pointer(tp->root, head);
 588         return 0;
 589 }
 590
 591 static void flow_destroy(struct tcf_proto *tp, bool rtnl_held,
 592                          struct netlink_ext_ack *extack)
 593 {
 594         struct flow_head *head = rtnl_dereference(tp->root);
 595         struct flow_filter *f, *next;
 596
 597         list_for_each_entry_safe(f, next, &head->filters, list) {
 598                 list_del_rcu(&f->list);
 599                 if (tcf_exts_get_net(&f->exts))
 600                         tcf_queue_work(&f->rwork, flow_destroy_filter_work);
 601                 else
 602                         __flow_destroy_filter(f);
 603         }
 604         kfree_rcu(head, rcu);
 605 }
 606
 607 static void *flow_get(struct tcf_proto *tp, u32 handle)
 608 {
 609         struct flow_head *head = rtnl_dereference(tp->root);
 610         struct flow_filter *f;
 611
 612         list_for_each_entry(f, &head->filters, list)
 613                 if (f->handle == handle)
 614                         return f;
 615         return NULL;
 616 }
 617
 618 static int flow_dump(struct net *net, struct tcf_proto *tp, void *fh,
 619                      struct sk_buff *skb, struct tcmsg *t, bool rtnl_held)
 620 {
 621         struct flow_filter *f = fh;
 622         struct nlattr *nest;
 623
 624         if (f == NULL)
 625                 return skb->len;
 626
 627         t->tcm_handle = f->handle;
 628
 629         nest = nla_nest_start_noflag(skb, TCA_OPTIONS);
 630         if (nest == NULL)
 631                 goto nla_put_failure;
 632
 633         if (nla_put_u32(skb, TCA_FLOW_KEYS, f->keymask) ||
 634             nla_put_u32(skb, TCA_FLOW_MODE, f->mode))
 635                 goto nla_put_failure;
 636
 637         if (f->mask != ~0 || f->xor != 0) {
 638                 if (nla_put_u32(skb, TCA_FLOW_MASK, f->mask) ||
 639                     nla_put_u32(skb, TCA_FLOW_XOR, f->xor))
 640                         goto nla_put_failure;
 641         }
 642         if (f->rshift &&
 643             nla_put_u32(skb, TCA_FLOW_RSHIFT, f->rshift))
 644                 goto nla_put_failure;
 645         if (f->addend &&
 646             nla_put_u32(skb, TCA_FLOW_ADDEND, f->addend))
 647                 goto nla_put_failure;
 648
 649         if (f->divisor &&
 650             nla_put_u32(skb, TCA_FLOW_DIVISOR, f->divisor))
 651                 goto nla_put_failure;
 652         if (f->baseclass &&
 653             nla_put_u32(skb, TCA_FLOW_BASECLASS, f->baseclass))
 654                 goto nla_put_failure;
 655
 656         if (f->perturb_period &&
 657             nla_put_u32(skb, TCA_FLOW_PERTURB, f->perturb_period / HZ))
 658                 goto nla_put_failure;
 659
 660         if (tcf_exts_dump(skb, &f->exts) < 0)
 661                 goto nla_put_failure;
 662 #ifdef CONFIG_NET_EMATCH
 663         if (f->ematches.hdr.nmatches &&
 664             tcf_em_tree_dump(skb, &f->ematches, TCA_FLOW_EMATCHES) < 0)
 665                 goto nla_put_failure;
 666 #endif
 667         nla_nest_end(skb, nest);
 668
 669         if (tcf_exts_dump_stats(skb, &f->exts) < 0)
 670                 goto nla_put_failure;
 671
 672         return skb->len;
 673
 674 nla_put_failure:
 675         nla_nest_cancel(skb, nest);
 676         return -1;
 677 }
 678
 679 static void flow_walk(struct tcf_proto *tp, struct tcf_walker *arg,
 680                       bool rtnl_held)
 681 {
 682         struct flow_head *head = rtnl_dereference(tp->root);
 683         struct flow_filter *f;
 684
 685         list_for_each_entry(f, &head->filters, list) {
 686                 if (!tc_cls_stats_dump(tp, arg, f))
 687                         break;
 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");