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 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
  30 #include <net/netfilter/nf_conntrack.h>
  31 #endif
  32
  33 struct flow_head {
  34         struct list_head        filters;
  35 };
  36
  37 struct flow_filter {
  38         struct list_head        list;
  39         struct tcf_exts         exts;
  40         struct tcf_ematch_tree  ematches;
  41         struct timer_list       perturb_timer;
  42         u32                     perturb_period;
  43         u32                     handle;
  44
  45         u32                     nkeys;
  46         u32                     keymask;
  47         u32                     mode;
  48         u32                     mask;
  49         u32                     xor;
  50         u32                     rshift;
  51         u32                     addend;
  52         u32                     divisor;
  53         u32                     baseclass;
  54         u32                     hashrnd;
  55 };
  56
  57 static const struct tcf_ext_map flow_ext_map = {
  58         .action = TCA_FLOW_ACT,
  59         .police = TCA_FLOW_POLICE,
  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, int nhoff)
  70 {
  71         __be32 *data = NULL, hdata;
  72
  73         switch (skb->protocol) {
  74         case htons(ETH_P_IP):
  75                 data = skb_header_pointer(skb,
  76                                           nhoff + offsetof(struct iphdr,
  77                                                            saddr),
  78                                           4, &hdata);
  79                 break;
  80         case htons(ETH_P_IPV6):
  81                 data = skb_header_pointer(skb,
  82                                          nhoff + offsetof(struct ipv6hdr,
  83                                                           saddr.s6_addr32[3]),
  84                                          4, &hdata);
  85                 break;
  86         }
  87
  88         if (data)
  89                 return ntohl(*data);
  90         return addr_fold(skb->sk);
  91 }
  92
  93 static u32 flow_get_dst(const struct sk_buff *skb, int nhoff)
  94 {
  95         __be32 *data = NULL, hdata;
  96
  97         switch (skb->protocol) {
  98         case htons(ETH_P_IP):
  99                 data = skb_header_pointer(skb,
 100                                           nhoff + offsetof(struct iphdr,
 101                                                            daddr),
 102                                           4, &hdata);
 103                 break;
 104         case htons(ETH_P_IPV6):
 105                 data = skb_header_pointer(skb,
 106                                          nhoff + offsetof(struct ipv6hdr,
 107                                                           daddr.s6_addr32[3]),
 108                                          4, &hdata);
 109                 break;
 110         }
 111
 112         if (data)
 113                 return ntohl(*data);
 114         return addr_fold(skb_dst(skb)) ^ (__force u16)skb->protocol;
 115 }
 116
 117 static u32 flow_get_proto(const struct sk_buff *skb, int nhoff)
 118 {
 119         __u8 *data = NULL, hdata;
 120
 121         switch (skb->protocol) {
 122         case htons(ETH_P_IP):
 123                 data = skb_header_pointer(skb,
 124                                           nhoff + offsetof(struct iphdr,
 125                                                            protocol),
 126                                           1, &hdata);
 127                 break;
 128         case htons(ETH_P_IPV6):
 129                 data = skb_header_pointer(skb,
 130                                          nhoff + offsetof(struct ipv6hdr,
 131                                                           nexthdr),
 132                                          1, &hdata);
 133                 break;
 134         }
 135         if (data)
 136                 return *data;
 137         return 0;
 138 }
 139
 140 /* helper function to get either src or dst port */
 141 static __be16 *flow_get_proto_common(const struct sk_buff *skb, int nhoff,
 142                                      __be16 *_port, int dst)
 143 {
 144         __be16 *port = NULL;
 145         int poff;
 146
 147         switch (skb->protocol) {
 148         case htons(ETH_P_IP): {
 149                 struct iphdr *iph, _iph;
 150
 151                 iph = skb_header_pointer(skb, nhoff, sizeof(_iph), &_iph);
 152                 if (!iph)
 153                         break;
 154                 if (ip_is_fragment(iph))
 155                         break;
 156                 poff = proto_ports_offset(iph->protocol);
 157                 if (poff >= 0)
 158                         port = skb_header_pointer(skb,
 159                                         nhoff + iph->ihl * 4 + poff + dst,
 160                                         sizeof(*_port), _port);
 161                 break;
 162         }
 163         case htons(ETH_P_IPV6): {
 164                 struct ipv6hdr *iph, _iph;
 165
 166                 iph = skb_header_pointer(skb, nhoff, sizeof(_iph), &_iph);
 167                 if (!iph)
 168                         break;
 169                 poff = proto_ports_offset(iph->nexthdr);
 170                 if (poff >= 0)
 171                         port = skb_header_pointer(skb,
 172                                         nhoff + sizeof(*iph) + poff + dst,
 173                                         sizeof(*_port), _port);
 174                 break;
 175         }
 176         }
 177
 178         return port;
 179 }
 180
 181 static u32 flow_get_proto_src(const struct sk_buff *skb, int nhoff)
 182 {
 183         __be16 _port, *port = flow_get_proto_common(skb, nhoff, &_port, 0);
 184
 185         if (port)
 186                 return ntohs(*port);
 187
 188         return addr_fold(skb->sk);
 189 }
 190
 191 static u32 flow_get_proto_dst(const struct sk_buff *skb, int nhoff)
 192 {
 193         __be16 _port, *port = flow_get_proto_common(skb, nhoff, &_port, 2);
 194
 195         if (port)
 196                 return ntohs(*port);
 197
 198         return addr_fold(skb_dst(skb)) ^ (__force u16)skb->protocol;
 199 }
 200
 201 static u32 flow_get_iif(const struct sk_buff *skb)
 202 {
 203         return skb->skb_iif;
 204 }
 205
 206 static u32 flow_get_priority(const struct sk_buff *skb)
 207 {
 208         return skb->priority;
 209 }
 210
 211 static u32 flow_get_mark(const struct sk_buff *skb)
 212 {
 213         return skb->mark;
 214 }
 215
 216 static u32 flow_get_nfct(const struct sk_buff *skb)
 217 {
 218 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
 219         return addr_fold(skb->nfct);
 220 #else
 221         return 0;
 222 #endif
 223 }
 224
 225 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
 226 #define CTTUPLE(skb, member)                                            \
 227 ({                                                                      \
 228         enum ip_conntrack_info ctinfo;                                  \
 229         const struct nf_conn *ct = nf_ct_get(skb, &ctinfo);             \
 230         if (ct == NULL)                                                 \
 231                 goto fallback;                                          \
 232         ct->tuplehash[CTINFO2DIR(ctinfo)].tuple.member;                 \
 233 })
 234 #else
 235 #define CTTUPLE(skb, member)                                            \
 236 ({                                                                      \
 237         goto fallback;                                                  \
 238         0;                                                              \
 239 })
 240 #endif
 241
 242 static u32 flow_get_nfct_src(const struct sk_buff *skb, int nhoff)
 243 {
 244         switch (skb->protocol) {
 245         case htons(ETH_P_IP):
 246                 return ntohl(CTTUPLE(skb, src.u3.ip));
 247         case htons(ETH_P_IPV6):
 248                 return ntohl(CTTUPLE(skb, src.u3.ip6[3]));
 249         }
 250 fallback:
 251         return flow_get_src(skb, nhoff);
 252 }
 253
 254 static u32 flow_get_nfct_dst(const struct sk_buff *skb, int nhoff)
 255 {
 256         switch (skb->protocol) {
 257         case htons(ETH_P_IP):
 258                 return ntohl(CTTUPLE(skb, dst.u3.ip));
 259         case htons(ETH_P_IPV6):
 260                 return ntohl(CTTUPLE(skb, dst.u3.ip6[3]));
 261         }
 262 fallback:
 263         return flow_get_dst(skb, nhoff);
 264 }
 265
 266 static u32 flow_get_nfct_proto_src(const struct sk_buff *skb, int nhoff)
 267 {
 268         return ntohs(CTTUPLE(skb, src.u.all));
 269 fallback:
 270         return flow_get_proto_src(skb, nhoff);
 271 }
 272
 273 static u32 flow_get_nfct_proto_dst(const struct sk_buff *skb, int nhoff)
 274 {
 275         return ntohs(CTTUPLE(skb, dst.u.all));
 276 fallback:
 277         return flow_get_proto_dst(skb, nhoff);
 278 }
 279
 280 static u32 flow_get_rtclassid(const struct sk_buff *skb)
 281 {
 282 #ifdef CONFIG_IP_ROUTE_CLASSID
 283         if (skb_dst(skb))
 284                 return skb_dst(skb)->tclassid;
 285 #endif
 286         return 0;
 287 }
 288
 289 static u32 flow_get_skuid(const struct sk_buff *skb)
 290 {
 291         if (skb->sk && skb->sk->sk_socket && skb->sk->sk_socket->file)
 292                 return skb->sk->sk_socket->file->f_cred->fsuid;
 293         return 0;
 294 }
 295
 296 static u32 flow_get_skgid(const struct sk_buff *skb)
 297 {
 298         if (skb->sk && skb->sk->sk_socket && skb->sk->sk_socket->file)
 299                 return skb->sk->sk_socket->file->f_cred->fsgid;
 300         return 0;
 301 }
 302
 303 static u32 flow_get_vlan_tag(const struct sk_buff *skb)
 304 {
 305         u16 uninitialized_var(tag);
 306
 307         if (vlan_get_tag(skb, &tag) < 0)
 308                 return 0;
 309         return tag & VLAN_VID_MASK;
 310 }
 311
 312 static u32 flow_get_rxhash(struct sk_buff *skb)
 313 {
 314         return skb_get_rxhash(skb);
 315 }
 316
 317 static u32 flow_key_get(struct sk_buff *skb, int key)
 318 {
 319         int nhoff = skb_network_offset(skb);
 320
 321         switch (key) {
 322         case FLOW_KEY_SRC:
 323                 return flow_get_src(skb, nhoff);
 324         case FLOW_KEY_DST:
 325                 return flow_get_dst(skb, nhoff);
 326         case FLOW_KEY_PROTO:
 327                 return flow_get_proto(skb, nhoff);
 328         case FLOW_KEY_PROTO_SRC:
 329                 return flow_get_proto_src(skb, nhoff);
 330         case FLOW_KEY_PROTO_DST:
 331                 return flow_get_proto_dst(skb, nhoff);
 332         case FLOW_KEY_IIF:
 333                 return flow_get_iif(skb);
 334         case FLOW_KEY_PRIORITY:
 335                 return flow_get_priority(skb);
 336         case FLOW_KEY_MARK:
 337                 return flow_get_mark(skb);
 338         case FLOW_KEY_NFCT:
 339                 return flow_get_nfct(skb);
 340         case FLOW_KEY_NFCT_SRC:
 341                 return flow_get_nfct_src(skb, nhoff);
 342         case FLOW_KEY_NFCT_DST:
 343                 return flow_get_nfct_dst(skb, nhoff);
 344         case FLOW_KEY_NFCT_PROTO_SRC:
 345                 return flow_get_nfct_proto_src(skb, nhoff);
 346         case FLOW_KEY_NFCT_PROTO_DST:
 347                 return flow_get_nfct_proto_dst(skb, nhoff);
 348         case FLOW_KEY_RTCLASSID:
 349                 return flow_get_rtclassid(skb);
 350         case FLOW_KEY_SKUID:
 351                 return flow_get_skuid(skb);
 352         case FLOW_KEY_SKGID:
 353                 return flow_get_skgid(skb);
 354         case FLOW_KEY_VLAN_TAG:
 355                 return flow_get_vlan_tag(skb);
 356         case FLOW_KEY_RXHASH:
 357                 return flow_get_rxhash(skb);
 358         default:
 359                 WARN_ON(1);
 360                 return 0;
 361         }
 362 }
 363
 364 static int flow_classify(struct sk_buff *skb, const struct tcf_proto *tp,
 365                          struct tcf_result *res)
 366 {
 367         struct flow_head *head = tp->root;
 368         struct flow_filter *f;
 369         u32 keymask;
 370         u32 classid;
 371         unsigned int n, key;
 372         int r;
 373
 374         list_for_each_entry(f, &head->filters, list) {
 375                 u32 keys[f->nkeys];
 376
 377                 if (!tcf_em_tree_match(skb, &f->ematches, NULL))
 378                         continue;
 379
 380                 keymask = f->keymask;
 381
 382                 for (n = 0; n < f->nkeys; n++) {
 383                         key = ffs(keymask) - 1;
 384                         keymask &= ~(1 << key);
 385                         keys[n] = flow_key_get(skb, key);
 386                 }
 387
 388                 if (f->mode == FLOW_MODE_HASH)
 389                         classid = jhash2(keys, f->nkeys, f->hashrnd);
 390                 else {
 391                         classid = keys[0];
 392                         classid = (classid & f->mask) ^ f->xor;
 393                         classid = (classid >> f->rshift) + f->addend;
 394                 }
 395
 396                 if (f->divisor)
 397                         classid %= f->divisor;
 398
 399                 res->class   = 0;
 400                 res->classid = TC_H_MAKE(f->baseclass, f->baseclass + classid);
 401
 402                 r = tcf_exts_exec(skb, &f->exts, res);
 403                 if (r < 0)
 404                         continue;
 405                 return r;
 406         }
 407         return -1;
 408 }
 409
 410 static void flow_perturbation(unsigned long arg)
 411 {
 412         struct flow_filter *f = (struct flow_filter *)arg;
 413
 414         get_random_bytes(&f->hashrnd, 4);
 415         if (f->perturb_period)
 416                 mod_timer(&f->perturb_timer, jiffies + f->perturb_period);
 417 }
 418
 419 static const struct nla_policy flow_policy[TCA_FLOW_MAX + 1] = {
 420         [TCA_FLOW_KEYS]         = { .type = NLA_U32 },
 421         [TCA_FLOW_MODE]         = { .type = NLA_U32 },
 422         [TCA_FLOW_BASECLASS]    = { .type = NLA_U32 },
 423         [TCA_FLOW_RSHIFT]       = { .type = NLA_U32 },
 424         [TCA_FLOW_ADDEND]       = { .type = NLA_U32 },
 425         [TCA_FLOW_MASK]         = { .type = NLA_U32 },
 426         [TCA_FLOW_XOR]          = { .type = NLA_U32 },
 427         [TCA_FLOW_DIVISOR]      = { .type = NLA_U32 },
 428         [TCA_FLOW_ACT]          = { .type = NLA_NESTED },
 429         [TCA_FLOW_POLICE]       = { .type = NLA_NESTED },
 430         [TCA_FLOW_EMATCHES]     = { .type = NLA_NESTED },
 431         [TCA_FLOW_PERTURB]      = { .type = NLA_U32 },
 432 };
 433
 434 static int flow_change(struct tcf_proto *tp, unsigned long base,
 435                        u32 handle, struct nlattr **tca,
 436                        unsigned long *arg)
 437 {
 438         struct flow_head *head = tp->root;
 439         struct flow_filter *f;
 440         struct nlattr *opt = tca[TCA_OPTIONS];
 441         struct nlattr *tb[TCA_FLOW_MAX + 1];
 442         struct tcf_exts e;
 443         struct tcf_ematch_tree t;
 444         unsigned int nkeys = 0;
 445         unsigned int perturb_period = 0;
 446         u32 baseclass = 0;
 447         u32 keymask = 0;
 448         u32 mode;
 449         int err;
 450
 451         if (opt == NULL)
 452                 return -EINVAL;
 453
 454         err = nla_parse_nested(tb, TCA_FLOW_MAX, opt, flow_policy);
 455         if (err < 0)
 456                 return err;
 457
 458         if (tb[TCA_FLOW_BASECLASS]) {
 459                 baseclass = nla_get_u32(tb[TCA_FLOW_BASECLASS]);
 460                 if (TC_H_MIN(baseclass) == 0)
 461                         return -EINVAL;
 462         }
 463
 464         if (tb[TCA_FLOW_KEYS]) {
 465                 keymask = nla_get_u32(tb[TCA_FLOW_KEYS]);
 466
 467                 nkeys = hweight32(keymask);
 468                 if (nkeys == 0)
 469                         return -EINVAL;
 470
 471                 if (fls(keymask) - 1 > FLOW_KEY_MAX)
 472                         return -EOPNOTSUPP;
 473         }
 474
 475         err = tcf_exts_validate(tp, tb, tca[TCA_RATE], &e, &flow_ext_map);
 476         if (err < 0)
 477                 return err;
 478
 479         err = tcf_em_tree_validate(tp, tb[TCA_FLOW_EMATCHES], &t);
 480         if (err < 0)
 481                 goto err1;
 482
 483         f = (struct flow_filter *)*arg;
 484         if (f != NULL) {
 485                 err = -EINVAL;
 486                 if (f->handle != handle && handle)
 487                         goto err2;
 488
 489                 mode = f->mode;
 490                 if (tb[TCA_FLOW_MODE])
 491                         mode = nla_get_u32(tb[TCA_FLOW_MODE]);
 492                 if (mode != FLOW_MODE_HASH && nkeys > 1)
 493                         goto err2;
 494
 495                 if (mode == FLOW_MODE_HASH)
 496                         perturb_period = f->perturb_period;
 497                 if (tb[TCA_FLOW_PERTURB]) {
 498                         if (mode != FLOW_MODE_HASH)
 499                                 goto err2;
 500                         perturb_period = nla_get_u32(tb[TCA_FLOW_PERTURB]) * HZ;
 501                 }
 502         } else {
 503                 err = -EINVAL;
 504                 if (!handle)
 505                         goto err2;
 506                 if (!tb[TCA_FLOW_KEYS])
 507                         goto err2;
 508
 509                 mode = FLOW_MODE_MAP;
 510                 if (tb[TCA_FLOW_MODE])
 511                         mode = nla_get_u32(tb[TCA_FLOW_MODE]);
 512                 if (mode != FLOW_MODE_HASH && nkeys > 1)
 513                         goto err2;
 514
 515                 if (tb[TCA_FLOW_PERTURB]) {
 516                         if (mode != FLOW_MODE_HASH)
 517                                 goto err2;
 518                         perturb_period = nla_get_u32(tb[TCA_FLOW_PERTURB]) * HZ;
 519                 }
 520
 521                 if (TC_H_MAJ(baseclass) == 0)
 522                         baseclass = TC_H_MAKE(tp->q->handle, baseclass);
 523                 if (TC_H_MIN(baseclass) == 0)
 524                         baseclass = TC_H_MAKE(baseclass, 1);
 525
 526                 err = -ENOBUFS;
 527                 f = kzalloc(sizeof(*f), GFP_KERNEL);
 528                 if (f == NULL)
 529                         goto err2;
 530
 531                 f->handle = handle;
 532                 f->mask   = ~0U;
 533
 534                 get_random_bytes(&f->hashrnd, 4);
 535                 f->perturb_timer.function = flow_perturbation;
 536                 f->perturb_timer.data = (unsigned long)f;
 537                 init_timer_deferrable(&f->perturb_timer);
 538         }
 539
 540         tcf_exts_change(tp, &f->exts, &e);
 541         tcf_em_tree_change(tp, &f->ematches, &t);
 542
 543         tcf_tree_lock(tp);
 544
 545         if (tb[TCA_FLOW_KEYS]) {
 546                 f->keymask = keymask;
 547                 f->nkeys   = nkeys;
 548         }
 549
 550         f->mode = mode;
 551
 552         if (tb[TCA_FLOW_MASK])
 553                 f->mask = nla_get_u32(tb[TCA_FLOW_MASK]);
 554         if (tb[TCA_FLOW_XOR])
 555                 f->xor = nla_get_u32(tb[TCA_FLOW_XOR]);
 556         if (tb[TCA_FLOW_RSHIFT])
 557                 f->rshift = nla_get_u32(tb[TCA_FLOW_RSHIFT]);
 558         if (tb[TCA_FLOW_ADDEND])
 559                 f->addend = nla_get_u32(tb[TCA_FLOW_ADDEND]);
 560
 561         if (tb[TCA_FLOW_DIVISOR])
 562                 f->divisor = nla_get_u32(tb[TCA_FLOW_DIVISOR]);
 563         if (baseclass)
 564                 f->baseclass = baseclass;
 565
 566         f->perturb_period = perturb_period;
 567         del_timer(&f->perturb_timer);
 568         if (perturb_period)
 569                 mod_timer(&f->perturb_timer, jiffies + perturb_period);
 570
 571         if (*arg == 0)
 572                 list_add_tail(&f->list, &head->filters);
 573
 574         tcf_tree_unlock(tp);
 575
 576         *arg = (unsigned long)f;
 577         return 0;
 578
 579 err2:
 580         tcf_em_tree_destroy(tp, &t);
 581 err1:
 582         tcf_exts_destroy(tp, &e);
 583         return err;
 584 }
 585
 586 static void flow_destroy_filter(struct tcf_proto *tp, struct flow_filter *f)
 587 {
 588         del_timer_sync(&f->perturb_timer);
 589         tcf_exts_destroy(tp, &f->exts);
 590         tcf_em_tree_destroy(tp, &f->ematches);
 591         kfree(f);
 592 }
 593
 594 static int flow_delete(struct tcf_proto *tp, unsigned long arg)
 595 {
 596         struct flow_filter *f = (struct flow_filter *)arg;
 597
 598         tcf_tree_lock(tp);
 599         list_del(&f->list);
 600         tcf_tree_unlock(tp);
 601         flow_destroy_filter(tp, f);
 602         return 0;
 603 }
 604
 605 static int flow_init(struct tcf_proto *tp)
 606 {
 607         struct flow_head *head;
 608
 609         head = kzalloc(sizeof(*head), GFP_KERNEL);
 610         if (head == NULL)
 611                 return -ENOBUFS;
 612         INIT_LIST_HEAD(&head->filters);
 613         tp->root = head;
 614         return 0;
 615 }
 616
 617 static void flow_destroy(struct tcf_proto *tp)
 618 {
 619         struct flow_head *head = tp->root;
 620         struct flow_filter *f, *next;
 621
 622         list_for_each_entry_safe(f, next, &head->filters, list) {
 623                 list_del(&f->list);
 624                 flow_destroy_filter(tp, f);
 625         }
 626         kfree(head);
 627 }
 628
 629 static unsigned long flow_get(struct tcf_proto *tp, u32 handle)
 630 {
 631         struct flow_head *head = tp->root;
 632         struct flow_filter *f;
 633
 634         list_for_each_entry(f, &head->filters, list)
 635                 if (f->handle == handle)
 636                         return (unsigned long)f;
 637         return 0;
 638 }
 639
 640 static void flow_put(struct tcf_proto *tp, unsigned long f)
 641 {
 642 }
 643
 644 static int flow_dump(struct tcf_proto *tp, unsigned long fh,
 645                      struct sk_buff *skb, struct tcmsg *t)
 646 {
 647         struct flow_filter *f = (struct flow_filter *)fh;
 648         struct nlattr *nest;
 649
 650         if (f == NULL)
 651                 return skb->len;
 652
 653         t->tcm_handle = f->handle;
 654
 655         nest = nla_nest_start(skb, TCA_OPTIONS);
 656         if (nest == NULL)
 657                 goto nla_put_failure;
 658
 659         NLA_PUT_U32(skb, TCA_FLOW_KEYS, f->keymask);
 660         NLA_PUT_U32(skb, TCA_FLOW_MODE, f->mode);
 661
 662         if (f->mask != ~0 || f->xor != 0) {
 663                 NLA_PUT_U32(skb, TCA_FLOW_MASK, f->mask);
 664                 NLA_PUT_U32(skb, TCA_FLOW_XOR, f->xor);
 665         }
 666         if (f->rshift)
 667                 NLA_PUT_U32(skb, TCA_FLOW_RSHIFT, f->rshift);
 668         if (f->addend)
 669                 NLA_PUT_U32(skb, TCA_FLOW_ADDEND, f->addend);
 670
 671         if (f->divisor)
 672                 NLA_PUT_U32(skb, TCA_FLOW_DIVISOR, f->divisor);
 673         if (f->baseclass)
 674                 NLA_PUT_U32(skb, TCA_FLOW_BASECLASS, f->baseclass);
 675
 676         if (f->perturb_period)
 677                 NLA_PUT_U32(skb, TCA_FLOW_PERTURB, f->perturb_period / HZ);
 678
 679         if (tcf_exts_dump(skb, &f->exts, &flow_ext_map) < 0)
 680                 goto nla_put_failure;
 681 #ifdef CONFIG_NET_EMATCH
 682         if (f->ematches.hdr.nmatches &&
 683             tcf_em_tree_dump(skb, &f->ematches, TCA_FLOW_EMATCHES) < 0)
 684                 goto nla_put_failure;
 685 #endif
 686         nla_nest_end(skb, nest);
 687
 688         if (tcf_exts_dump_stats(skb, &f->exts, &flow_ext_map) < 0)
 689                 goto nla_put_failure;
 690
 691         return skb->len;
 692
 693 nla_put_failure:
 694         nlmsg_trim(skb, nest);
 695         return -1;
 696 }
 697
 698 static void flow_walk(struct tcf_proto *tp, struct tcf_walker *arg)
 699 {
 700         struct flow_head *head = tp->root;
 701         struct flow_filter *f;
 702
 703         list_for_each_entry(f, &head->filters, list) {
 704                 if (arg->count < arg->skip)
 705                         goto skip;
 706                 if (arg->fn(tp, (unsigned long)f, arg) < 0) {
 707                         arg->stop = 1;
 708                         break;
 709                 }
 710 skip:
 711                 arg->count++;
 712         }
 713 }
 714
 715 static struct tcf_proto_ops cls_flow_ops __read_mostly = {
 716         .kind           = "flow",
 717         .classify       = flow_classify,
 718         .init           = flow_init,
 719         .destroy        = flow_destroy,
 720         .change         = flow_change,
 721         .delete         = flow_delete,
 722         .get            = flow_get,
 723         .put            = flow_put,
 724         .dump           = flow_dump,
 725         .walk           = flow_walk,
 726         .owner          = THIS_MODULE,
 727 };
 728
 729 static int __init cls_flow_init(void)
 730 {
 731         return register_tcf_proto_ops(&cls_flow_ops);
 732 }
 733
 734 static void __exit cls_flow_exit(void)
 735 {
 736         unregister_tcf_proto_ops(&cls_flow_ops);
 737 }
 738
 739 module_init(cls_flow_init);
 740 module_exit(cls_flow_exit);
 741
 742 MODULE_LICENSE("GPL");
 743 MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
 744 MODULE_DESCRIPTION("TC flow classifier");